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1/* SCTP kernel implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999-2000 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 * Copyright (c) 2001-2002 Intel Corp.
6 * Copyright (c) 2002 Nokia Corp.
7 *
8 * This is part of the SCTP Linux Kernel Implementation.
9 *
10 * These are the state functions for the state machine.
11 *
12 * This SCTP implementation is free software;
13 * you can redistribute it and/or modify it under the terms of
14 * the GNU General Public License as published by
15 * the Free Software Foundation; either version 2, or (at your option)
16 * any later version.
17 *
18 * This SCTP implementation is distributed in the hope that it
19 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
20 * ************************
21 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
22 * See the GNU General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License
25 * along with GNU CC; see the file COPYING. If not, write to
26 * the Free Software Foundation, 59 Temple Place - Suite 330,
27 * Boston, MA 02111-1307, USA.
28 *
29 * Please send any bug reports or fixes you make to the
30 * email address(es):
31 * lksctp developers <lksctp-developers@lists.sourceforge.net>
32 *
33 * Or submit a bug report through the following website:
34 * http://www.sf.net/projects/lksctp
35 *
36 * Written or modified by:
37 * La Monte H.P. Yarroll <piggy@acm.org>
38 * Karl Knutson <karl@athena.chicago.il.us>
39 * Mathew Kotowsky <kotowsky@sctp.org>
40 * Sridhar Samudrala <samudrala@us.ibm.com>
41 * Jon Grimm <jgrimm@us.ibm.com>
42 * Hui Huang <hui.huang@nokia.com>
43 * Dajiang Zhang <dajiang.zhang@nokia.com>
44 * Daisy Chang <daisyc@us.ibm.com>
45 * Ardelle Fan <ardelle.fan@intel.com>
46 * Ryan Layer <rmlayer@us.ibm.com>
47 * Kevin Gao <kevin.gao@intel.com>
48 *
49 * Any bugs reported given to us we will try to fix... any fixes shared will
50 * be incorporated into the next SCTP release.
51 */
52
53#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
54
55#include <linux/types.h>
56#include <linux/kernel.h>
57#include <linux/ip.h>
58#include <linux/ipv6.h>
59#include <linux/net.h>
60#include <linux/inet.h>
61#include <linux/slab.h>
62#include <net/sock.h>
63#include <net/inet_ecn.h>
64#include <linux/skbuff.h>
65#include <net/sctp/sctp.h>
66#include <net/sctp/sm.h>
67#include <net/sctp/structs.h>
68
69static struct sctp_packet *sctp_abort_pkt_new(const struct sctp_endpoint *ep,
70 const struct sctp_association *asoc,
71 struct sctp_chunk *chunk,
72 const void *payload,
73 size_t paylen);
74static int sctp_eat_data(const struct sctp_association *asoc,
75 struct sctp_chunk *chunk,
76 sctp_cmd_seq_t *commands);
77static struct sctp_packet *sctp_ootb_pkt_new(const struct sctp_association *asoc,
78 const struct sctp_chunk *chunk);
79static void sctp_send_stale_cookie_err(const struct sctp_endpoint *ep,
80 const struct sctp_association *asoc,
81 const struct sctp_chunk *chunk,
82 sctp_cmd_seq_t *commands,
83 struct sctp_chunk *err_chunk);
84static sctp_disposition_t sctp_sf_do_5_2_6_stale(const struct sctp_endpoint *ep,
85 const struct sctp_association *asoc,
86 const sctp_subtype_t type,
87 void *arg,
88 sctp_cmd_seq_t *commands);
89static sctp_disposition_t sctp_sf_shut_8_4_5(const struct sctp_endpoint *ep,
90 const struct sctp_association *asoc,
91 const sctp_subtype_t type,
92 void *arg,
93 sctp_cmd_seq_t *commands);
94static sctp_disposition_t sctp_sf_tabort_8_4_8(const struct sctp_endpoint *ep,
95 const struct sctp_association *asoc,
96 const sctp_subtype_t type,
97 void *arg,
98 sctp_cmd_seq_t *commands);
99static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk);
100
101static sctp_disposition_t sctp_stop_t1_and_abort(sctp_cmd_seq_t *commands,
102 __be16 error, int sk_err,
103 const struct sctp_association *asoc,
104 struct sctp_transport *transport);
105
106static sctp_disposition_t sctp_sf_abort_violation(
107 const struct sctp_endpoint *ep,
108 const struct sctp_association *asoc,
109 void *arg,
110 sctp_cmd_seq_t *commands,
111 const __u8 *payload,
112 const size_t paylen);
113
114static sctp_disposition_t sctp_sf_violation_chunklen(
115 const struct sctp_endpoint *ep,
116 const struct sctp_association *asoc,
117 const sctp_subtype_t type,
118 void *arg,
119 sctp_cmd_seq_t *commands);
120
121static sctp_disposition_t sctp_sf_violation_paramlen(
122 const struct sctp_endpoint *ep,
123 const struct sctp_association *asoc,
124 const sctp_subtype_t type,
125 void *arg, void *ext,
126 sctp_cmd_seq_t *commands);
127
128static sctp_disposition_t sctp_sf_violation_ctsn(
129 const struct sctp_endpoint *ep,
130 const struct sctp_association *asoc,
131 const sctp_subtype_t type,
132 void *arg,
133 sctp_cmd_seq_t *commands);
134
135static sctp_disposition_t sctp_sf_violation_chunk(
136 const struct sctp_endpoint *ep,
137 const struct sctp_association *asoc,
138 const sctp_subtype_t type,
139 void *arg,
140 sctp_cmd_seq_t *commands);
141
142static sctp_ierror_t sctp_sf_authenticate(const struct sctp_endpoint *ep,
143 const struct sctp_association *asoc,
144 const sctp_subtype_t type,
145 struct sctp_chunk *chunk);
146
147static sctp_disposition_t __sctp_sf_do_9_1_abort(const struct sctp_endpoint *ep,
148 const struct sctp_association *asoc,
149 const sctp_subtype_t type,
150 void *arg,
151 sctp_cmd_seq_t *commands);
152
153/* Small helper function that checks if the chunk length
154 * is of the appropriate length. The 'required_length' argument
155 * is set to be the size of a specific chunk we are testing.
156 * Return Values: 1 = Valid length
157 * 0 = Invalid length
158 *
159 */
160static inline int
161sctp_chunk_length_valid(struct sctp_chunk *chunk,
162 __u16 required_length)
163{
164 __u16 chunk_length = ntohs(chunk->chunk_hdr->length);
165
166 if (unlikely(chunk_length < required_length))
167 return 0;
168
169 return 1;
170}
171
172/**********************************************************
173 * These are the state functions for handling chunk events.
174 **********************************************************/
175
176/*
177 * Process the final SHUTDOWN COMPLETE.
178 *
179 * Section: 4 (C) (diagram), 9.2
180 * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify
181 * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be
182 * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint
183 * should stop the T2-shutdown timer and remove all knowledge of the
184 * association (and thus the association enters the CLOSED state).
185 *
186 * Verification Tag: 8.5.1(C), sctpimpguide 2.41.
187 * C) Rules for packet carrying SHUTDOWN COMPLETE:
188 * ...
189 * - The receiver of a SHUTDOWN COMPLETE shall accept the packet
190 * if the Verification Tag field of the packet matches its own tag and
191 * the T bit is not set
192 * OR
193 * it is set to its peer's tag and the T bit is set in the Chunk
194 * Flags.
195 * Otherwise, the receiver MUST silently discard the packet
196 * and take no further action. An endpoint MUST ignore the
197 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
198 *
199 * Inputs
200 * (endpoint, asoc, chunk)
201 *
202 * Outputs
203 * (asoc, reply_msg, msg_up, timers, counters)
204 *
205 * The return value is the disposition of the chunk.
206 */
207sctp_disposition_t sctp_sf_do_4_C(const struct sctp_endpoint *ep,
208 const struct sctp_association *asoc,
209 const sctp_subtype_t type,
210 void *arg,
211 sctp_cmd_seq_t *commands)
212{
213 struct sctp_chunk *chunk = arg;
214 struct sctp_ulpevent *ev;
215
216 if (!sctp_vtag_verify_either(chunk, asoc))
217 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
218
219 /* RFC 2960 6.10 Bundling
220 *
221 * An endpoint MUST NOT bundle INIT, INIT ACK or
222 * SHUTDOWN COMPLETE with any other chunks.
223 */
224 if (!chunk->singleton)
225 return sctp_sf_violation_chunk(ep, asoc, type, arg, commands);
226
227 /* Make sure that the SHUTDOWN_COMPLETE chunk has a valid length. */
228 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
229 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
230 commands);
231
232 /* RFC 2960 10.2 SCTP-to-ULP
233 *
234 * H) SHUTDOWN COMPLETE notification
235 *
236 * When SCTP completes the shutdown procedures (section 9.2) this
237 * notification is passed to the upper layer.
238 */
239 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
240 0, 0, 0, NULL, GFP_ATOMIC);
241 if (ev)
242 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
243 SCTP_ULPEVENT(ev));
244
245 /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint
246 * will verify that it is in SHUTDOWN-ACK-SENT state, if it is
247 * not the chunk should be discarded. If the endpoint is in
248 * the SHUTDOWN-ACK-SENT state the endpoint should stop the
249 * T2-shutdown timer and remove all knowledge of the
250 * association (and thus the association enters the CLOSED
251 * state).
252 */
253 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
254 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
255
256 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
257 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
258
259 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
260 SCTP_STATE(SCTP_STATE_CLOSED));
261
262 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
263 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
264
265 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
266
267 return SCTP_DISPOSITION_DELETE_TCB;
268}
269
270/*
271 * Respond to a normal INIT chunk.
272 * We are the side that is being asked for an association.
273 *
274 * Section: 5.1 Normal Establishment of an Association, B
275 * B) "Z" shall respond immediately with an INIT ACK chunk. The
276 * destination IP address of the INIT ACK MUST be set to the source
277 * IP address of the INIT to which this INIT ACK is responding. In
278 * the response, besides filling in other parameters, "Z" must set the
279 * Verification Tag field to Tag_A, and also provide its own
280 * Verification Tag (Tag_Z) in the Initiate Tag field.
281 *
282 * Verification Tag: Must be 0.
283 *
284 * Inputs
285 * (endpoint, asoc, chunk)
286 *
287 * Outputs
288 * (asoc, reply_msg, msg_up, timers, counters)
289 *
290 * The return value is the disposition of the chunk.
291 */
292sctp_disposition_t sctp_sf_do_5_1B_init(const struct sctp_endpoint *ep,
293 const struct sctp_association *asoc,
294 const sctp_subtype_t type,
295 void *arg,
296 sctp_cmd_seq_t *commands)
297{
298 struct sctp_chunk *chunk = arg;
299 struct sctp_chunk *repl;
300 struct sctp_association *new_asoc;
301 struct sctp_chunk *err_chunk;
302 struct sctp_packet *packet;
303 sctp_unrecognized_param_t *unk_param;
304 int len;
305
306 /* 6.10 Bundling
307 * An endpoint MUST NOT bundle INIT, INIT ACK or
308 * SHUTDOWN COMPLETE with any other chunks.
309 *
310 * IG Section 2.11.2
311 * Furthermore, we require that the receiver of an INIT chunk MUST
312 * enforce these rules by silently discarding an arriving packet
313 * with an INIT chunk that is bundled with other chunks.
314 */
315 if (!chunk->singleton)
316 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
317
318 /* If the packet is an OOTB packet which is temporarily on the
319 * control endpoint, respond with an ABORT.
320 */
321 if (ep == sctp_sk((sctp_get_ctl_sock()))->ep) {
322 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES);
323 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
324 }
325
326 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
327 * Tag.
328 */
329 if (chunk->sctp_hdr->vtag != 0)
330 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
331
332 /* Make sure that the INIT chunk has a valid length.
333 * Normally, this would cause an ABORT with a Protocol Violation
334 * error, but since we don't have an association, we'll
335 * just discard the packet.
336 */
337 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
338 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
339
340 /* If the INIT is coming toward a closing socket, we'll send back
341 * and ABORT. Essentially, this catches the race of INIT being
342 * backloged to the socket at the same time as the user isses close().
343 * Since the socket and all its associations are going away, we
344 * can treat this OOTB
345 */
346 if (sctp_sstate(ep->base.sk, CLOSING))
347 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
348
349 /* Verify the INIT chunk before processing it. */
350 err_chunk = NULL;
351 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
352 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
353 &err_chunk)) {
354 /* This chunk contains fatal error. It is to be discarded.
355 * Send an ABORT, with causes if there is any.
356 */
357 if (err_chunk) {
358 packet = sctp_abort_pkt_new(ep, asoc, arg,
359 (__u8 *)(err_chunk->chunk_hdr) +
360 sizeof(sctp_chunkhdr_t),
361 ntohs(err_chunk->chunk_hdr->length) -
362 sizeof(sctp_chunkhdr_t));
363
364 sctp_chunk_free(err_chunk);
365
366 if (packet) {
367 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
368 SCTP_PACKET(packet));
369 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
370 return SCTP_DISPOSITION_CONSUME;
371 } else {
372 return SCTP_DISPOSITION_NOMEM;
373 }
374 } else {
375 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg,
376 commands);
377 }
378 }
379
380 /* Grab the INIT header. */
381 chunk->subh.init_hdr = (sctp_inithdr_t *)chunk->skb->data;
382
383 /* Tag the variable length parameters. */
384 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
385
386 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
387 if (!new_asoc)
388 goto nomem;
389
390 if (sctp_assoc_set_bind_addr_from_ep(new_asoc,
391 sctp_scope(sctp_source(chunk)),
392 GFP_ATOMIC) < 0)
393 goto nomem_init;
394
395 /* The call, sctp_process_init(), can fail on memory allocation. */
396 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk),
397 (sctp_init_chunk_t *)chunk->chunk_hdr,
398 GFP_ATOMIC))
399 goto nomem_init;
400
401 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
402
403 /* If there are errors need to be reported for unknown parameters,
404 * make sure to reserve enough room in the INIT ACK for them.
405 */
406 len = 0;
407 if (err_chunk)
408 len = ntohs(err_chunk->chunk_hdr->length) -
409 sizeof(sctp_chunkhdr_t);
410
411 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
412 if (!repl)
413 goto nomem_init;
414
415 /* If there are errors need to be reported for unknown parameters,
416 * include them in the outgoing INIT ACK as "Unrecognized parameter"
417 * parameter.
418 */
419 if (err_chunk) {
420 /* Get the "Unrecognized parameter" parameter(s) out of the
421 * ERROR chunk generated by sctp_verify_init(). Since the
422 * error cause code for "unknown parameter" and the
423 * "Unrecognized parameter" type is the same, we can
424 * construct the parameters in INIT ACK by copying the
425 * ERROR causes over.
426 */
427 unk_param = (sctp_unrecognized_param_t *)
428 ((__u8 *)(err_chunk->chunk_hdr) +
429 sizeof(sctp_chunkhdr_t));
430 /* Replace the cause code with the "Unrecognized parameter"
431 * parameter type.
432 */
433 sctp_addto_chunk(repl, len, unk_param);
434 sctp_chunk_free(err_chunk);
435 }
436
437 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
438
439 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
440
441 /*
442 * Note: After sending out INIT ACK with the State Cookie parameter,
443 * "Z" MUST NOT allocate any resources, nor keep any states for the
444 * new association. Otherwise, "Z" will be vulnerable to resource
445 * attacks.
446 */
447 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
448
449 return SCTP_DISPOSITION_DELETE_TCB;
450
451nomem_init:
452 sctp_association_free(new_asoc);
453nomem:
454 if (err_chunk)
455 sctp_chunk_free(err_chunk);
456 return SCTP_DISPOSITION_NOMEM;
457}
458
459/*
460 * Respond to a normal INIT ACK chunk.
461 * We are the side that is initiating the association.
462 *
463 * Section: 5.1 Normal Establishment of an Association, C
464 * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init
465 * timer and leave COOKIE-WAIT state. "A" shall then send the State
466 * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start
467 * the T1-cookie timer, and enter the COOKIE-ECHOED state.
468 *
469 * Note: The COOKIE ECHO chunk can be bundled with any pending outbound
470 * DATA chunks, but it MUST be the first chunk in the packet and
471 * until the COOKIE ACK is returned the sender MUST NOT send any
472 * other packets to the peer.
473 *
474 * Verification Tag: 3.3.3
475 * If the value of the Initiate Tag in a received INIT ACK chunk is
476 * found to be 0, the receiver MUST treat it as an error and close the
477 * association by transmitting an ABORT.
478 *
479 * Inputs
480 * (endpoint, asoc, chunk)
481 *
482 * Outputs
483 * (asoc, reply_msg, msg_up, timers, counters)
484 *
485 * The return value is the disposition of the chunk.
486 */
487sctp_disposition_t sctp_sf_do_5_1C_ack(const struct sctp_endpoint *ep,
488 const struct sctp_association *asoc,
489 const sctp_subtype_t type,
490 void *arg,
491 sctp_cmd_seq_t *commands)
492{
493 struct sctp_chunk *chunk = arg;
494 sctp_init_chunk_t *initchunk;
495 struct sctp_chunk *err_chunk;
496 struct sctp_packet *packet;
497
498 if (!sctp_vtag_verify(chunk, asoc))
499 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
500
501 /* 6.10 Bundling
502 * An endpoint MUST NOT bundle INIT, INIT ACK or
503 * SHUTDOWN COMPLETE with any other chunks.
504 */
505 if (!chunk->singleton)
506 return sctp_sf_violation_chunk(ep, asoc, type, arg, commands);
507
508 /* Make sure that the INIT-ACK chunk has a valid length */
509 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_initack_chunk_t)))
510 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
511 commands);
512 /* Grab the INIT header. */
513 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
514
515 /* Verify the INIT chunk before processing it. */
516 err_chunk = NULL;
517 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
518 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
519 &err_chunk)) {
520
521 sctp_error_t error = SCTP_ERROR_NO_RESOURCE;
522
523 /* This chunk contains fatal error. It is to be discarded.
524 * Send an ABORT, with causes. If there are no causes,
525 * then there wasn't enough memory. Just terminate
526 * the association.
527 */
528 if (err_chunk) {
529 packet = sctp_abort_pkt_new(ep, asoc, arg,
530 (__u8 *)(err_chunk->chunk_hdr) +
531 sizeof(sctp_chunkhdr_t),
532 ntohs(err_chunk->chunk_hdr->length) -
533 sizeof(sctp_chunkhdr_t));
534
535 sctp_chunk_free(err_chunk);
536
537 if (packet) {
538 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
539 SCTP_PACKET(packet));
540 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
541 error = SCTP_ERROR_INV_PARAM;
542 }
543 }
544
545 /* SCTP-AUTH, Section 6.3:
546 * It should be noted that if the receiver wants to tear
547 * down an association in an authenticated way only, the
548 * handling of malformed packets should not result in
549 * tearing down the association.
550 *
551 * This means that if we only want to abort associations
552 * in an authenticated way (i.e AUTH+ABORT), then we
553 * can't destroy this association just because the packet
554 * was malformed.
555 */
556 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
557 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
558
559 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
560 return sctp_stop_t1_and_abort(commands, error, ECONNREFUSED,
561 asoc, chunk->transport);
562 }
563
564 /* Tag the variable length parameters. Note that we never
565 * convert the parameters in an INIT chunk.
566 */
567 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
568
569 initchunk = (sctp_init_chunk_t *) chunk->chunk_hdr;
570
571 sctp_add_cmd_sf(commands, SCTP_CMD_PEER_INIT,
572 SCTP_PEER_INIT(initchunk));
573
574 /* Reset init error count upon receipt of INIT-ACK. */
575 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
576
577 /* 5.1 C) "A" shall stop the T1-init timer and leave
578 * COOKIE-WAIT state. "A" shall then ... start the T1-cookie
579 * timer, and enter the COOKIE-ECHOED state.
580 */
581 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
582 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
583 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
584 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
585 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
586 SCTP_STATE(SCTP_STATE_COOKIE_ECHOED));
587
588 /* SCTP-AUTH: genereate the assocition shared keys so that
589 * we can potentially signe the COOKIE-ECHO.
590 */
591 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_SHKEY, SCTP_NULL());
592
593 /* 5.1 C) "A" shall then send the State Cookie received in the
594 * INIT ACK chunk in a COOKIE ECHO chunk, ...
595 */
596 /* If there is any errors to report, send the ERROR chunk generated
597 * for unknown parameters as well.
598 */
599 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_COOKIE_ECHO,
600 SCTP_CHUNK(err_chunk));
601
602 return SCTP_DISPOSITION_CONSUME;
603}
604
605/*
606 * Respond to a normal COOKIE ECHO chunk.
607 * We are the side that is being asked for an association.
608 *
609 * Section: 5.1 Normal Establishment of an Association, D
610 * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply
611 * with a COOKIE ACK chunk after building a TCB and moving to
612 * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with
613 * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK
614 * chunk MUST be the first chunk in the packet.
615 *
616 * IMPLEMENTATION NOTE: An implementation may choose to send the
617 * Communication Up notification to the SCTP user upon reception
618 * of a valid COOKIE ECHO chunk.
619 *
620 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
621 * D) Rules for packet carrying a COOKIE ECHO
622 *
623 * - When sending a COOKIE ECHO, the endpoint MUST use the value of the
624 * Initial Tag received in the INIT ACK.
625 *
626 * - The receiver of a COOKIE ECHO follows the procedures in Section 5.
627 *
628 * Inputs
629 * (endpoint, asoc, chunk)
630 *
631 * Outputs
632 * (asoc, reply_msg, msg_up, timers, counters)
633 *
634 * The return value is the disposition of the chunk.
635 */
636sctp_disposition_t sctp_sf_do_5_1D_ce(const struct sctp_endpoint *ep,
637 const struct sctp_association *asoc,
638 const sctp_subtype_t type, void *arg,
639 sctp_cmd_seq_t *commands)
640{
641 struct sctp_chunk *chunk = arg;
642 struct sctp_association *new_asoc;
643 sctp_init_chunk_t *peer_init;
644 struct sctp_chunk *repl;
645 struct sctp_ulpevent *ev, *ai_ev = NULL;
646 int error = 0;
647 struct sctp_chunk *err_chk_p;
648 struct sock *sk;
649
650 /* If the packet is an OOTB packet which is temporarily on the
651 * control endpoint, respond with an ABORT.
652 */
653 if (ep == sctp_sk((sctp_get_ctl_sock()))->ep) {
654 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES);
655 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
656 }
657
658 /* Make sure that the COOKIE_ECHO chunk has a valid length.
659 * In this case, we check that we have enough for at least a
660 * chunk header. More detailed verification is done
661 * in sctp_unpack_cookie().
662 */
663 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
664 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
665
666 /* If the endpoint is not listening or if the number of associations
667 * on the TCP-style socket exceed the max backlog, respond with an
668 * ABORT.
669 */
670 sk = ep->base.sk;
671 if (!sctp_sstate(sk, LISTENING) ||
672 (sctp_style(sk, TCP) && sk_acceptq_is_full(sk)))
673 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
674
675 /* "Decode" the chunk. We have no optional parameters so we
676 * are in good shape.
677 */
678 chunk->subh.cookie_hdr =
679 (struct sctp_signed_cookie *)chunk->skb->data;
680 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
681 sizeof(sctp_chunkhdr_t)))
682 goto nomem;
683
684 /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
685 * "Z" will reply with a COOKIE ACK chunk after building a TCB
686 * and moving to the ESTABLISHED state.
687 */
688 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
689 &err_chk_p);
690
691 /* FIXME:
692 * If the re-build failed, what is the proper error path
693 * from here?
694 *
695 * [We should abort the association. --piggy]
696 */
697 if (!new_asoc) {
698 /* FIXME: Several errors are possible. A bad cookie should
699 * be silently discarded, but think about logging it too.
700 */
701 switch (error) {
702 case -SCTP_IERROR_NOMEM:
703 goto nomem;
704
705 case -SCTP_IERROR_STALE_COOKIE:
706 sctp_send_stale_cookie_err(ep, asoc, chunk, commands,
707 err_chk_p);
708 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
709
710 case -SCTP_IERROR_BAD_SIG:
711 default:
712 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
713 }
714 }
715
716
717 /* Delay state machine commands until later.
718 *
719 * Re-build the bind address for the association is done in
720 * the sctp_unpack_cookie() already.
721 */
722 /* This is a brand-new association, so these are not yet side
723 * effects--it is safe to run them here.
724 */
725 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
726
727 if (!sctp_process_init(new_asoc, chunk,
728 &chunk->subh.cookie_hdr->c.peer_addr,
729 peer_init, GFP_ATOMIC))
730 goto nomem_init;
731
732 /* SCTP-AUTH: Now that we've populate required fields in
733 * sctp_process_init, set up the assocaition shared keys as
734 * necessary so that we can potentially authenticate the ACK
735 */
736 error = sctp_auth_asoc_init_active_key(new_asoc, GFP_ATOMIC);
737 if (error)
738 goto nomem_init;
739
740 /* SCTP-AUTH: auth_chunk pointer is only set when the cookie-echo
741 * is supposed to be authenticated and we have to do delayed
742 * authentication. We've just recreated the association using
743 * the information in the cookie and now it's much easier to
744 * do the authentication.
745 */
746 if (chunk->auth_chunk) {
747 struct sctp_chunk auth;
748 sctp_ierror_t ret;
749
750 /* set-up our fake chunk so that we can process it */
751 auth.skb = chunk->auth_chunk;
752 auth.asoc = chunk->asoc;
753 auth.sctp_hdr = chunk->sctp_hdr;
754 auth.chunk_hdr = (sctp_chunkhdr_t *)skb_push(chunk->auth_chunk,
755 sizeof(sctp_chunkhdr_t));
756 skb_pull(chunk->auth_chunk, sizeof(sctp_chunkhdr_t));
757 auth.transport = chunk->transport;
758
759 ret = sctp_sf_authenticate(ep, new_asoc, type, &auth);
760
761 /* We can now safely free the auth_chunk clone */
762 kfree_skb(chunk->auth_chunk);
763
764 if (ret != SCTP_IERROR_NO_ERROR) {
765 sctp_association_free(new_asoc);
766 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
767 }
768 }
769
770 repl = sctp_make_cookie_ack(new_asoc, chunk);
771 if (!repl)
772 goto nomem_init;
773
774 /* RFC 2960 5.1 Normal Establishment of an Association
775 *
776 * D) IMPLEMENTATION NOTE: An implementation may choose to
777 * send the Communication Up notification to the SCTP user
778 * upon reception of a valid COOKIE ECHO chunk.
779 */
780 ev = sctp_ulpevent_make_assoc_change(new_asoc, 0, SCTP_COMM_UP, 0,
781 new_asoc->c.sinit_num_ostreams,
782 new_asoc->c.sinit_max_instreams,
783 NULL, GFP_ATOMIC);
784 if (!ev)
785 goto nomem_ev;
786
787 /* Sockets API Draft Section 5.3.1.6
788 * When a peer sends a Adaptation Layer Indication parameter , SCTP
789 * delivers this notification to inform the application that of the
790 * peers requested adaptation layer.
791 */
792 if (new_asoc->peer.adaptation_ind) {
793 ai_ev = sctp_ulpevent_make_adaptation_indication(new_asoc,
794 GFP_ATOMIC);
795 if (!ai_ev)
796 goto nomem_aiev;
797 }
798
799 /* Add all the state machine commands now since we've created
800 * everything. This way we don't introduce memory corruptions
801 * during side-effect processing and correclty count established
802 * associations.
803 */
804 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
805 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
806 SCTP_STATE(SCTP_STATE_ESTABLISHED));
807 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
808 SCTP_INC_STATS(SCTP_MIB_PASSIVEESTABS);
809 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
810
811 if (new_asoc->autoclose)
812 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
813 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
814
815 /* This will send the COOKIE ACK */
816 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
817
818 /* Queue the ASSOC_CHANGE event */
819 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
820
821 /* Send up the Adaptation Layer Indication event */
822 if (ai_ev)
823 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
824 SCTP_ULPEVENT(ai_ev));
825
826 return SCTP_DISPOSITION_CONSUME;
827
828nomem_aiev:
829 sctp_ulpevent_free(ev);
830nomem_ev:
831 sctp_chunk_free(repl);
832nomem_init:
833 sctp_association_free(new_asoc);
834nomem:
835 return SCTP_DISPOSITION_NOMEM;
836}
837
838/*
839 * Respond to a normal COOKIE ACK chunk.
840 * We are the side that is being asked for an association.
841 *
842 * RFC 2960 5.1 Normal Establishment of an Association
843 *
844 * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the
845 * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie
846 * timer. It may also notify its ULP about the successful
847 * establishment of the association with a Communication Up
848 * notification (see Section 10).
849 *
850 * Verification Tag:
851 * Inputs
852 * (endpoint, asoc, chunk)
853 *
854 * Outputs
855 * (asoc, reply_msg, msg_up, timers, counters)
856 *
857 * The return value is the disposition of the chunk.
858 */
859sctp_disposition_t sctp_sf_do_5_1E_ca(const struct sctp_endpoint *ep,
860 const struct sctp_association *asoc,
861 const sctp_subtype_t type, void *arg,
862 sctp_cmd_seq_t *commands)
863{
864 struct sctp_chunk *chunk = arg;
865 struct sctp_ulpevent *ev;
866
867 if (!sctp_vtag_verify(chunk, asoc))
868 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
869
870 /* Verify that the chunk length for the COOKIE-ACK is OK.
871 * If we don't do this, any bundled chunks may be junked.
872 */
873 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
874 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
875 commands);
876
877 /* Reset init error count upon receipt of COOKIE-ACK,
878 * to avoid problems with the managemement of this
879 * counter in stale cookie situations when a transition back
880 * from the COOKIE-ECHOED state to the COOKIE-WAIT
881 * state is performed.
882 */
883 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
884
885 /* RFC 2960 5.1 Normal Establishment of an Association
886 *
887 * E) Upon reception of the COOKIE ACK, endpoint "A" will move
888 * from the COOKIE-ECHOED state to the ESTABLISHED state,
889 * stopping the T1-cookie timer.
890 */
891 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
892 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
893 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
894 SCTP_STATE(SCTP_STATE_ESTABLISHED));
895 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
896 SCTP_INC_STATS(SCTP_MIB_ACTIVEESTABS);
897 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
898 if (asoc->autoclose)
899 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
900 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
901
902 /* It may also notify its ULP about the successful
903 * establishment of the association with a Communication Up
904 * notification (see Section 10).
905 */
906 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP,
907 0, asoc->c.sinit_num_ostreams,
908 asoc->c.sinit_max_instreams,
909 NULL, GFP_ATOMIC);
910
911 if (!ev)
912 goto nomem;
913
914 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
915
916 /* Sockets API Draft Section 5.3.1.6
917 * When a peer sends a Adaptation Layer Indication parameter , SCTP
918 * delivers this notification to inform the application that of the
919 * peers requested adaptation layer.
920 */
921 if (asoc->peer.adaptation_ind) {
922 ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
923 if (!ev)
924 goto nomem;
925
926 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
927 SCTP_ULPEVENT(ev));
928 }
929
930 return SCTP_DISPOSITION_CONSUME;
931nomem:
932 return SCTP_DISPOSITION_NOMEM;
933}
934
935/* Generate and sendout a heartbeat packet. */
936static sctp_disposition_t sctp_sf_heartbeat(const struct sctp_endpoint *ep,
937 const struct sctp_association *asoc,
938 const sctp_subtype_t type,
939 void *arg,
940 sctp_cmd_seq_t *commands)
941{
942 struct sctp_transport *transport = (struct sctp_transport *) arg;
943 struct sctp_chunk *reply;
944
945 /* Send a heartbeat to our peer. */
946 reply = sctp_make_heartbeat(asoc, transport);
947 if (!reply)
948 return SCTP_DISPOSITION_NOMEM;
949
950 /* Set rto_pending indicating that an RTT measurement
951 * is started with this heartbeat chunk.
952 */
953 sctp_add_cmd_sf(commands, SCTP_CMD_RTO_PENDING,
954 SCTP_TRANSPORT(transport));
955
956 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
957 return SCTP_DISPOSITION_CONSUME;
958}
959
960/* Generate a HEARTBEAT packet on the given transport. */
961sctp_disposition_t sctp_sf_sendbeat_8_3(const struct sctp_endpoint *ep,
962 const struct sctp_association *asoc,
963 const sctp_subtype_t type,
964 void *arg,
965 sctp_cmd_seq_t *commands)
966{
967 struct sctp_transport *transport = (struct sctp_transport *) arg;
968
969 if (asoc->overall_error_count >= asoc->max_retrans) {
970 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
971 SCTP_ERROR(ETIMEDOUT));
972 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
973 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
974 SCTP_PERR(SCTP_ERROR_NO_ERROR));
975 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
976 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
977 return SCTP_DISPOSITION_DELETE_TCB;
978 }
979
980 /* Section 3.3.5.
981 * The Sender-specific Heartbeat Info field should normally include
982 * information about the sender's current time when this HEARTBEAT
983 * chunk is sent and the destination transport address to which this
984 * HEARTBEAT is sent (see Section 8.3).
985 */
986
987 if (transport->param_flags & SPP_HB_ENABLE) {
988 if (SCTP_DISPOSITION_NOMEM ==
989 sctp_sf_heartbeat(ep, asoc, type, arg,
990 commands))
991 return SCTP_DISPOSITION_NOMEM;
992
993 /* Set transport error counter and association error counter
994 * when sending heartbeat.
995 */
996 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_HB_SENT,
997 SCTP_TRANSPORT(transport));
998 }
999 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_IDLE,
1000 SCTP_TRANSPORT(transport));
1001 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMER_UPDATE,
1002 SCTP_TRANSPORT(transport));
1003
1004 return SCTP_DISPOSITION_CONSUME;
1005}
1006
1007/*
1008 * Process an heartbeat request.
1009 *
1010 * Section: 8.3 Path Heartbeat
1011 * The receiver of the HEARTBEAT should immediately respond with a
1012 * HEARTBEAT ACK that contains the Heartbeat Information field copied
1013 * from the received HEARTBEAT chunk.
1014 *
1015 * Verification Tag: 8.5 Verification Tag [Normal verification]
1016 * When receiving an SCTP packet, the endpoint MUST ensure that the
1017 * value in the Verification Tag field of the received SCTP packet
1018 * matches its own Tag. If the received Verification Tag value does not
1019 * match the receiver's own tag value, the receiver shall silently
1020 * discard the packet and shall not process it any further except for
1021 * those cases listed in Section 8.5.1 below.
1022 *
1023 * Inputs
1024 * (endpoint, asoc, chunk)
1025 *
1026 * Outputs
1027 * (asoc, reply_msg, msg_up, timers, counters)
1028 *
1029 * The return value is the disposition of the chunk.
1030 */
1031sctp_disposition_t sctp_sf_beat_8_3(const struct sctp_endpoint *ep,
1032 const struct sctp_association *asoc,
1033 const sctp_subtype_t type,
1034 void *arg,
1035 sctp_cmd_seq_t *commands)
1036{
1037 struct sctp_chunk *chunk = arg;
1038 struct sctp_chunk *reply;
1039 size_t paylen = 0;
1040
1041 if (!sctp_vtag_verify(chunk, asoc))
1042 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1043
1044 /* Make sure that the HEARTBEAT chunk has a valid length. */
1045 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t)))
1046 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1047 commands);
1048
1049 /* 8.3 The receiver of the HEARTBEAT should immediately
1050 * respond with a HEARTBEAT ACK that contains the Heartbeat
1051 * Information field copied from the received HEARTBEAT chunk.
1052 */
1053 chunk->subh.hb_hdr = (sctp_heartbeathdr_t *) chunk->skb->data;
1054 paylen = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
1055 if (!pskb_pull(chunk->skb, paylen))
1056 goto nomem;
1057
1058 reply = sctp_make_heartbeat_ack(asoc, chunk,
1059 chunk->subh.hb_hdr, paylen);
1060 if (!reply)
1061 goto nomem;
1062
1063 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
1064 return SCTP_DISPOSITION_CONSUME;
1065
1066nomem:
1067 return SCTP_DISPOSITION_NOMEM;
1068}
1069
1070/*
1071 * Process the returning HEARTBEAT ACK.
1072 *
1073 * Section: 8.3 Path Heartbeat
1074 * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT
1075 * should clear the error counter of the destination transport
1076 * address to which the HEARTBEAT was sent, and mark the destination
1077 * transport address as active if it is not so marked. The endpoint may
1078 * optionally report to the upper layer when an inactive destination
1079 * address is marked as active due to the reception of the latest
1080 * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also
1081 * clear the association overall error count as well (as defined
1082 * in section 8.1).
1083 *
1084 * The receiver of the HEARTBEAT ACK should also perform an RTT
1085 * measurement for that destination transport address using the time
1086 * value carried in the HEARTBEAT ACK chunk.
1087 *
1088 * Verification Tag: 8.5 Verification Tag [Normal verification]
1089 *
1090 * Inputs
1091 * (endpoint, asoc, chunk)
1092 *
1093 * Outputs
1094 * (asoc, reply_msg, msg_up, timers, counters)
1095 *
1096 * The return value is the disposition of the chunk.
1097 */
1098sctp_disposition_t sctp_sf_backbeat_8_3(const struct sctp_endpoint *ep,
1099 const struct sctp_association *asoc,
1100 const sctp_subtype_t type,
1101 void *arg,
1102 sctp_cmd_seq_t *commands)
1103{
1104 struct sctp_chunk *chunk = arg;
1105 union sctp_addr from_addr;
1106 struct sctp_transport *link;
1107 sctp_sender_hb_info_t *hbinfo;
1108 unsigned long max_interval;
1109
1110 if (!sctp_vtag_verify(chunk, asoc))
1111 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1112
1113 /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */
1114 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t) +
1115 sizeof(sctp_sender_hb_info_t)))
1116 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1117 commands);
1118
1119 hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
1120 /* Make sure that the length of the parameter is what we expect */
1121 if (ntohs(hbinfo->param_hdr.length) !=
1122 sizeof(sctp_sender_hb_info_t)) {
1123 return SCTP_DISPOSITION_DISCARD;
1124 }
1125
1126 from_addr = hbinfo->daddr;
1127 link = sctp_assoc_lookup_paddr(asoc, &from_addr);
1128
1129 /* This should never happen, but lets log it if so. */
1130 if (unlikely(!link)) {
1131 if (from_addr.sa.sa_family == AF_INET6) {
1132 net_warn_ratelimited("%s association %p could not find address %pI6\n",
1133 __func__,
1134 asoc,
1135 &from_addr.v6.sin6_addr);
1136 } else {
1137 net_warn_ratelimited("%s association %p could not find address %pI4\n",
1138 __func__,
1139 asoc,
1140 &from_addr.v4.sin_addr.s_addr);
1141 }
1142 return SCTP_DISPOSITION_DISCARD;
1143 }
1144
1145 /* Validate the 64-bit random nonce. */
1146 if (hbinfo->hb_nonce != link->hb_nonce)
1147 return SCTP_DISPOSITION_DISCARD;
1148
1149 max_interval = link->hbinterval + link->rto;
1150
1151 /* Check if the timestamp looks valid. */
1152 if (time_after(hbinfo->sent_at, jiffies) ||
1153 time_after(jiffies, hbinfo->sent_at + max_interval)) {
1154 SCTP_DEBUG_PRINTK("%s: HEARTBEAT ACK with invalid timestamp "
1155 "received for transport: %p\n",
1156 __func__, link);
1157 return SCTP_DISPOSITION_DISCARD;
1158 }
1159
1160 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of
1161 * the HEARTBEAT should clear the error counter of the
1162 * destination transport address to which the HEARTBEAT was
1163 * sent and mark the destination transport address as active if
1164 * it is not so marked.
1165 */
1166 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_ON, SCTP_TRANSPORT(link));
1167
1168 return SCTP_DISPOSITION_CONSUME;
1169}
1170
1171/* Helper function to send out an abort for the restart
1172 * condition.
1173 */
1174static int sctp_sf_send_restart_abort(union sctp_addr *ssa,
1175 struct sctp_chunk *init,
1176 sctp_cmd_seq_t *commands)
1177{
1178 int len;
1179 struct sctp_packet *pkt;
1180 union sctp_addr_param *addrparm;
1181 struct sctp_errhdr *errhdr;
1182 struct sctp_endpoint *ep;
1183 char buffer[sizeof(struct sctp_errhdr)+sizeof(union sctp_addr_param)];
1184 struct sctp_af *af = sctp_get_af_specific(ssa->v4.sin_family);
1185
1186 /* Build the error on the stack. We are way to malloc crazy
1187 * throughout the code today.
1188 */
1189 errhdr = (struct sctp_errhdr *)buffer;
1190 addrparm = (union sctp_addr_param *)errhdr->variable;
1191
1192 /* Copy into a parm format. */
1193 len = af->to_addr_param(ssa, addrparm);
1194 len += sizeof(sctp_errhdr_t);
1195
1196 errhdr->cause = SCTP_ERROR_RESTART;
1197 errhdr->length = htons(len);
1198
1199 /* Assign to the control socket. */
1200 ep = sctp_sk((sctp_get_ctl_sock()))->ep;
1201
1202 /* Association is NULL since this may be a restart attack and we
1203 * want to send back the attacker's vtag.
1204 */
1205 pkt = sctp_abort_pkt_new(ep, NULL, init, errhdr, len);
1206
1207 if (!pkt)
1208 goto out;
1209 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, SCTP_PACKET(pkt));
1210
1211 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
1212
1213 /* Discard the rest of the inbound packet. */
1214 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
1215
1216out:
1217 /* Even if there is no memory, treat as a failure so
1218 * the packet will get dropped.
1219 */
1220 return 0;
1221}
1222
1223static bool list_has_sctp_addr(const struct list_head *list,
1224 union sctp_addr *ipaddr)
1225{
1226 struct sctp_transport *addr;
1227
1228 list_for_each_entry(addr, list, transports) {
1229 if (sctp_cmp_addr_exact(ipaddr, &addr->ipaddr))
1230 return true;
1231 }
1232
1233 return false;
1234}
1235/* A restart is occurring, check to make sure no new addresses
1236 * are being added as we may be under a takeover attack.
1237 */
1238static int sctp_sf_check_restart_addrs(const struct sctp_association *new_asoc,
1239 const struct sctp_association *asoc,
1240 struct sctp_chunk *init,
1241 sctp_cmd_seq_t *commands)
1242{
1243 struct sctp_transport *new_addr;
1244 int ret = 1;
1245
1246 /* Implementor's Guide - Section 5.2.2
1247 * ...
1248 * Before responding the endpoint MUST check to see if the
1249 * unexpected INIT adds new addresses to the association. If new
1250 * addresses are added to the association, the endpoint MUST respond
1251 * with an ABORT..
1252 */
1253
1254 /* Search through all current addresses and make sure
1255 * we aren't adding any new ones.
1256 */
1257 list_for_each_entry(new_addr, &new_asoc->peer.transport_addr_list,
1258 transports) {
1259 if (!list_has_sctp_addr(&asoc->peer.transport_addr_list,
1260 &new_addr->ipaddr)) {
1261 sctp_sf_send_restart_abort(&new_addr->ipaddr, init,
1262 commands);
1263 ret = 0;
1264 break;
1265 }
1266 }
1267
1268 /* Return success if all addresses were found. */
1269 return ret;
1270}
1271
1272/* Populate the verification/tie tags based on overlapping INIT
1273 * scenario.
1274 *
1275 * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state.
1276 */
1277static void sctp_tietags_populate(struct sctp_association *new_asoc,
1278 const struct sctp_association *asoc)
1279{
1280 switch (asoc->state) {
1281
1282 /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */
1283
1284 case SCTP_STATE_COOKIE_WAIT:
1285 new_asoc->c.my_vtag = asoc->c.my_vtag;
1286 new_asoc->c.my_ttag = asoc->c.my_vtag;
1287 new_asoc->c.peer_ttag = 0;
1288 break;
1289
1290 case SCTP_STATE_COOKIE_ECHOED:
1291 new_asoc->c.my_vtag = asoc->c.my_vtag;
1292 new_asoc->c.my_ttag = asoc->c.my_vtag;
1293 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1294 break;
1295
1296 /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED,
1297 * COOKIE-WAIT and SHUTDOWN-ACK-SENT
1298 */
1299 default:
1300 new_asoc->c.my_ttag = asoc->c.my_vtag;
1301 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1302 break;
1303 }
1304
1305 /* Other parameters for the endpoint SHOULD be copied from the
1306 * existing parameters of the association (e.g. number of
1307 * outbound streams) into the INIT ACK and cookie.
1308 */
1309 new_asoc->rwnd = asoc->rwnd;
1310 new_asoc->c.sinit_num_ostreams = asoc->c.sinit_num_ostreams;
1311 new_asoc->c.sinit_max_instreams = asoc->c.sinit_max_instreams;
1312 new_asoc->c.initial_tsn = asoc->c.initial_tsn;
1313}
1314
1315/*
1316 * Compare vtag/tietag values to determine unexpected COOKIE-ECHO
1317 * handling action.
1318 *
1319 * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists.
1320 *
1321 * Returns value representing action to be taken. These action values
1322 * correspond to Action/Description values in RFC 2960, Table 2.
1323 */
1324static char sctp_tietags_compare(struct sctp_association *new_asoc,
1325 const struct sctp_association *asoc)
1326{
1327 /* In this case, the peer may have restarted. */
1328 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1329 (asoc->c.peer_vtag != new_asoc->c.peer_vtag) &&
1330 (asoc->c.my_vtag == new_asoc->c.my_ttag) &&
1331 (asoc->c.peer_vtag == new_asoc->c.peer_ttag))
1332 return 'A';
1333
1334 /* Collision case B. */
1335 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1336 ((asoc->c.peer_vtag != new_asoc->c.peer_vtag) ||
1337 (0 == asoc->c.peer_vtag))) {
1338 return 'B';
1339 }
1340
1341 /* Collision case D. */
1342 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1343 (asoc->c.peer_vtag == new_asoc->c.peer_vtag))
1344 return 'D';
1345
1346 /* Collision case C. */
1347 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1348 (asoc->c.peer_vtag == new_asoc->c.peer_vtag) &&
1349 (0 == new_asoc->c.my_ttag) &&
1350 (0 == new_asoc->c.peer_ttag))
1351 return 'C';
1352
1353 /* No match to any of the special cases; discard this packet. */
1354 return 'E';
1355}
1356
1357/* Common helper routine for both duplicate and simulataneous INIT
1358 * chunk handling.
1359 */
1360static sctp_disposition_t sctp_sf_do_unexpected_init(
1361 const struct sctp_endpoint *ep,
1362 const struct sctp_association *asoc,
1363 const sctp_subtype_t type,
1364 void *arg, sctp_cmd_seq_t *commands)
1365{
1366 sctp_disposition_t retval;
1367 struct sctp_chunk *chunk = arg;
1368 struct sctp_chunk *repl;
1369 struct sctp_association *new_asoc;
1370 struct sctp_chunk *err_chunk;
1371 struct sctp_packet *packet;
1372 sctp_unrecognized_param_t *unk_param;
1373 int len;
1374
1375 /* 6.10 Bundling
1376 * An endpoint MUST NOT bundle INIT, INIT ACK or
1377 * SHUTDOWN COMPLETE with any other chunks.
1378 *
1379 * IG Section 2.11.2
1380 * Furthermore, we require that the receiver of an INIT chunk MUST
1381 * enforce these rules by silently discarding an arriving packet
1382 * with an INIT chunk that is bundled with other chunks.
1383 */
1384 if (!chunk->singleton)
1385 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1386
1387 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
1388 * Tag.
1389 */
1390 if (chunk->sctp_hdr->vtag != 0)
1391 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
1392
1393 /* Make sure that the INIT chunk has a valid length.
1394 * In this case, we generate a protocol violation since we have
1395 * an association established.
1396 */
1397 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
1398 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1399 commands);
1400 /* Grab the INIT header. */
1401 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
1402
1403 /* Tag the variable length parameters. */
1404 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
1405
1406 /* Verify the INIT chunk before processing it. */
1407 err_chunk = NULL;
1408 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
1409 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
1410 &err_chunk)) {
1411 /* This chunk contains fatal error. It is to be discarded.
1412 * Send an ABORT, with causes if there is any.
1413 */
1414 if (err_chunk) {
1415 packet = sctp_abort_pkt_new(ep, asoc, arg,
1416 (__u8 *)(err_chunk->chunk_hdr) +
1417 sizeof(sctp_chunkhdr_t),
1418 ntohs(err_chunk->chunk_hdr->length) -
1419 sizeof(sctp_chunkhdr_t));
1420
1421 if (packet) {
1422 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
1423 SCTP_PACKET(packet));
1424 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
1425 retval = SCTP_DISPOSITION_CONSUME;
1426 } else {
1427 retval = SCTP_DISPOSITION_NOMEM;
1428 }
1429 goto cleanup;
1430 } else {
1431 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg,
1432 commands);
1433 }
1434 }
1435
1436 /*
1437 * Other parameters for the endpoint SHOULD be copied from the
1438 * existing parameters of the association (e.g. number of
1439 * outbound streams) into the INIT ACK and cookie.
1440 * FIXME: We are copying parameters from the endpoint not the
1441 * association.
1442 */
1443 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
1444 if (!new_asoc)
1445 goto nomem;
1446
1447 if (sctp_assoc_set_bind_addr_from_ep(new_asoc,
1448 sctp_scope(sctp_source(chunk)), GFP_ATOMIC) < 0)
1449 goto nomem;
1450
1451 /* In the outbound INIT ACK the endpoint MUST copy its current
1452 * Verification Tag and Peers Verification tag into a reserved
1453 * place (local tie-tag and per tie-tag) within the state cookie.
1454 */
1455 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk),
1456 (sctp_init_chunk_t *)chunk->chunk_hdr,
1457 GFP_ATOMIC))
1458 goto nomem;
1459
1460 /* Make sure no new addresses are being added during the
1461 * restart. Do not do this check for COOKIE-WAIT state,
1462 * since there are no peer addresses to check against.
1463 * Upon return an ABORT will have been sent if needed.
1464 */
1465 if (!sctp_state(asoc, COOKIE_WAIT)) {
1466 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk,
1467 commands)) {
1468 retval = SCTP_DISPOSITION_CONSUME;
1469 goto nomem_retval;
1470 }
1471 }
1472
1473 sctp_tietags_populate(new_asoc, asoc);
1474
1475 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
1476
1477 /* If there are errors need to be reported for unknown parameters,
1478 * make sure to reserve enough room in the INIT ACK for them.
1479 */
1480 len = 0;
1481 if (err_chunk) {
1482 len = ntohs(err_chunk->chunk_hdr->length) -
1483 sizeof(sctp_chunkhdr_t);
1484 }
1485
1486 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
1487 if (!repl)
1488 goto nomem;
1489
1490 /* If there are errors need to be reported for unknown parameters,
1491 * include them in the outgoing INIT ACK as "Unrecognized parameter"
1492 * parameter.
1493 */
1494 if (err_chunk) {
1495 /* Get the "Unrecognized parameter" parameter(s) out of the
1496 * ERROR chunk generated by sctp_verify_init(). Since the
1497 * error cause code for "unknown parameter" and the
1498 * "Unrecognized parameter" type is the same, we can
1499 * construct the parameters in INIT ACK by copying the
1500 * ERROR causes over.
1501 */
1502 unk_param = (sctp_unrecognized_param_t *)
1503 ((__u8 *)(err_chunk->chunk_hdr) +
1504 sizeof(sctp_chunkhdr_t));
1505 /* Replace the cause code with the "Unrecognized parameter"
1506 * parameter type.
1507 */
1508 sctp_addto_chunk(repl, len, unk_param);
1509 }
1510
1511 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
1512 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1513
1514 /*
1515 * Note: After sending out INIT ACK with the State Cookie parameter,
1516 * "Z" MUST NOT allocate any resources for this new association.
1517 * Otherwise, "Z" will be vulnerable to resource attacks.
1518 */
1519 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
1520 retval = SCTP_DISPOSITION_CONSUME;
1521
1522 return retval;
1523
1524nomem:
1525 retval = SCTP_DISPOSITION_NOMEM;
1526nomem_retval:
1527 if (new_asoc)
1528 sctp_association_free(new_asoc);
1529cleanup:
1530 if (err_chunk)
1531 sctp_chunk_free(err_chunk);
1532 return retval;
1533}
1534
1535/*
1536 * Handle simultaneous INIT.
1537 * This means we started an INIT and then we got an INIT request from
1538 * our peer.
1539 *
1540 * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B)
1541 * This usually indicates an initialization collision, i.e., each
1542 * endpoint is attempting, at about the same time, to establish an
1543 * association with the other endpoint.
1544 *
1545 * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an
1546 * endpoint MUST respond with an INIT ACK using the same parameters it
1547 * sent in its original INIT chunk (including its Verification Tag,
1548 * unchanged). These original parameters are combined with those from the
1549 * newly received INIT chunk. The endpoint shall also generate a State
1550 * Cookie with the INIT ACK. The endpoint uses the parameters sent in its
1551 * INIT to calculate the State Cookie.
1552 *
1553 * After that, the endpoint MUST NOT change its state, the T1-init
1554 * timer shall be left running and the corresponding TCB MUST NOT be
1555 * destroyed. The normal procedures for handling State Cookies when
1556 * a TCB exists will resolve the duplicate INITs to a single association.
1557 *
1558 * For an endpoint that is in the COOKIE-ECHOED state it MUST populate
1559 * its Tie-Tags with the Tag information of itself and its peer (see
1560 * section 5.2.2 for a description of the Tie-Tags).
1561 *
1562 * Verification Tag: Not explicit, but an INIT can not have a valid
1563 * verification tag, so we skip the check.
1564 *
1565 * Inputs
1566 * (endpoint, asoc, chunk)
1567 *
1568 * Outputs
1569 * (asoc, reply_msg, msg_up, timers, counters)
1570 *
1571 * The return value is the disposition of the chunk.
1572 */
1573sctp_disposition_t sctp_sf_do_5_2_1_siminit(const struct sctp_endpoint *ep,
1574 const struct sctp_association *asoc,
1575 const sctp_subtype_t type,
1576 void *arg,
1577 sctp_cmd_seq_t *commands)
1578{
1579 /* Call helper to do the real work for both simulataneous and
1580 * duplicate INIT chunk handling.
1581 */
1582 return sctp_sf_do_unexpected_init(ep, asoc, type, arg, commands);
1583}
1584
1585/*
1586 * Handle duplicated INIT messages. These are usually delayed
1587 * restransmissions.
1588 *
1589 * Section: 5.2.2 Unexpected INIT in States Other than CLOSED,
1590 * COOKIE-ECHOED and COOKIE-WAIT
1591 *
1592 * Unless otherwise stated, upon reception of an unexpected INIT for
1593 * this association, the endpoint shall generate an INIT ACK with a
1594 * State Cookie. In the outbound INIT ACK the endpoint MUST copy its
1595 * current Verification Tag and peer's Verification Tag into a reserved
1596 * place within the state cookie. We shall refer to these locations as
1597 * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet
1598 * containing this INIT ACK MUST carry a Verification Tag value equal to
1599 * the Initiation Tag found in the unexpected INIT. And the INIT ACK
1600 * MUST contain a new Initiation Tag (randomly generated see Section
1601 * 5.3.1). Other parameters for the endpoint SHOULD be copied from the
1602 * existing parameters of the association (e.g. number of outbound
1603 * streams) into the INIT ACK and cookie.
1604 *
1605 * After sending out the INIT ACK, the endpoint shall take no further
1606 * actions, i.e., the existing association, including its current state,
1607 * and the corresponding TCB MUST NOT be changed.
1608 *
1609 * Note: Only when a TCB exists and the association is not in a COOKIE-
1610 * WAIT state are the Tie-Tags populated. For a normal association INIT
1611 * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be
1612 * set to 0 (indicating that no previous TCB existed). The INIT ACK and
1613 * State Cookie are populated as specified in section 5.2.1.
1614 *
1615 * Verification Tag: Not specified, but an INIT has no way of knowing
1616 * what the verification tag could be, so we ignore it.
1617 *
1618 * Inputs
1619 * (endpoint, asoc, chunk)
1620 *
1621 * Outputs
1622 * (asoc, reply_msg, msg_up, timers, counters)
1623 *
1624 * The return value is the disposition of the chunk.
1625 */
1626sctp_disposition_t sctp_sf_do_5_2_2_dupinit(const struct sctp_endpoint *ep,
1627 const struct sctp_association *asoc,
1628 const sctp_subtype_t type,
1629 void *arg,
1630 sctp_cmd_seq_t *commands)
1631{
1632 /* Call helper to do the real work for both simulataneous and
1633 * duplicate INIT chunk handling.
1634 */
1635 return sctp_sf_do_unexpected_init(ep, asoc, type, arg, commands);
1636}
1637
1638
1639/*
1640 * Unexpected INIT-ACK handler.
1641 *
1642 * Section 5.2.3
1643 * If an INIT ACK received by an endpoint in any state other than the
1644 * COOKIE-WAIT state, the endpoint should discard the INIT ACK chunk.
1645 * An unexpected INIT ACK usually indicates the processing of an old or
1646 * duplicated INIT chunk.
1647*/
1648sctp_disposition_t sctp_sf_do_5_2_3_initack(const struct sctp_endpoint *ep,
1649 const struct sctp_association *asoc,
1650 const sctp_subtype_t type,
1651 void *arg, sctp_cmd_seq_t *commands)
1652{
1653 /* Per the above section, we'll discard the chunk if we have an
1654 * endpoint. If this is an OOTB INIT-ACK, treat it as such.
1655 */
1656 if (ep == sctp_sk((sctp_get_ctl_sock()))->ep)
1657 return sctp_sf_ootb(ep, asoc, type, arg, commands);
1658 else
1659 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
1660}
1661
1662/* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A')
1663 *
1664 * Section 5.2.4
1665 * A) In this case, the peer may have restarted.
1666 */
1667static sctp_disposition_t sctp_sf_do_dupcook_a(const struct sctp_endpoint *ep,
1668 const struct sctp_association *asoc,
1669 struct sctp_chunk *chunk,
1670 sctp_cmd_seq_t *commands,
1671 struct sctp_association *new_asoc)
1672{
1673 sctp_init_chunk_t *peer_init;
1674 struct sctp_ulpevent *ev;
1675 struct sctp_chunk *repl;
1676 struct sctp_chunk *err;
1677 sctp_disposition_t disposition;
1678
1679 /* new_asoc is a brand-new association, so these are not yet
1680 * side effects--it is safe to run them here.
1681 */
1682 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1683
1684 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), peer_init,
1685 GFP_ATOMIC))
1686 goto nomem;
1687
1688 /* Make sure no new addresses are being added during the
1689 * restart. Though this is a pretty complicated attack
1690 * since you'd have to get inside the cookie.
1691 */
1692 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk, commands)) {
1693 return SCTP_DISPOSITION_CONSUME;
1694 }
1695
1696 /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes
1697 * the peer has restarted (Action A), it MUST NOT setup a new
1698 * association but instead resend the SHUTDOWN ACK and send an ERROR
1699 * chunk with a "Cookie Received while Shutting Down" error cause to
1700 * its peer.
1701 */
1702 if (sctp_state(asoc, SHUTDOWN_ACK_SENT)) {
1703 disposition = sctp_sf_do_9_2_reshutack(ep, asoc,
1704 SCTP_ST_CHUNK(chunk->chunk_hdr->type),
1705 chunk, commands);
1706 if (SCTP_DISPOSITION_NOMEM == disposition)
1707 goto nomem;
1708
1709 err = sctp_make_op_error(asoc, chunk,
1710 SCTP_ERROR_COOKIE_IN_SHUTDOWN,
1711 NULL, 0, 0);
1712 if (err)
1713 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1714 SCTP_CHUNK(err));
1715
1716 return SCTP_DISPOSITION_CONSUME;
1717 }
1718
1719 /* For now, stop pending T3-rtx and SACK timers, fail any unsent/unacked
1720 * data. Consider the optional choice of resending of this data.
1721 */
1722 sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
1723 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1724 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
1725 sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_OUTQUEUE, SCTP_NULL());
1726
1727 /* Stop pending T4-rto timer, teardown ASCONF queue, ASCONF-ACK queue
1728 * and ASCONF-ACK cache.
1729 */
1730 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1731 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
1732 sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_ASCONF_QUEUE, SCTP_NULL());
1733
1734 repl = sctp_make_cookie_ack(new_asoc, chunk);
1735 if (!repl)
1736 goto nomem;
1737
1738 /* Report association restart to upper layer. */
1739 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_RESTART, 0,
1740 new_asoc->c.sinit_num_ostreams,
1741 new_asoc->c.sinit_max_instreams,
1742 NULL, GFP_ATOMIC);
1743 if (!ev)
1744 goto nomem_ev;
1745
1746 /* Update the content of current association. */
1747 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1748 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1749 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
1750 return SCTP_DISPOSITION_CONSUME;
1751
1752nomem_ev:
1753 sctp_chunk_free(repl);
1754nomem:
1755 return SCTP_DISPOSITION_NOMEM;
1756}
1757
1758/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B')
1759 *
1760 * Section 5.2.4
1761 * B) In this case, both sides may be attempting to start an association
1762 * at about the same time but the peer endpoint started its INIT
1763 * after responding to the local endpoint's INIT
1764 */
1765/* This case represents an initialization collision. */
1766static sctp_disposition_t sctp_sf_do_dupcook_b(const struct sctp_endpoint *ep,
1767 const struct sctp_association *asoc,
1768 struct sctp_chunk *chunk,
1769 sctp_cmd_seq_t *commands,
1770 struct sctp_association *new_asoc)
1771{
1772 sctp_init_chunk_t *peer_init;
1773 struct sctp_chunk *repl;
1774
1775 /* new_asoc is a brand-new association, so these are not yet
1776 * side effects--it is safe to run them here.
1777 */
1778 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1779 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), peer_init,
1780 GFP_ATOMIC))
1781 goto nomem;
1782
1783 /* Update the content of current association. */
1784 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1785 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1786 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1787 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
1788 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
1789
1790 repl = sctp_make_cookie_ack(new_asoc, chunk);
1791 if (!repl)
1792 goto nomem;
1793
1794 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1795
1796 /* RFC 2960 5.1 Normal Establishment of an Association
1797 *
1798 * D) IMPLEMENTATION NOTE: An implementation may choose to
1799 * send the Communication Up notification to the SCTP user
1800 * upon reception of a valid COOKIE ECHO chunk.
1801 *
1802 * Sadly, this needs to be implemented as a side-effect, because
1803 * we are not guaranteed to have set the association id of the real
1804 * association and so these notifications need to be delayed until
1805 * the association id is allocated.
1806 */
1807
1808 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_CHANGE, SCTP_U8(SCTP_COMM_UP));
1809
1810 /* Sockets API Draft Section 5.3.1.6
1811 * When a peer sends a Adaptation Layer Indication parameter , SCTP
1812 * delivers this notification to inform the application that of the
1813 * peers requested adaptation layer.
1814 *
1815 * This also needs to be done as a side effect for the same reason as
1816 * above.
1817 */
1818 if (asoc->peer.adaptation_ind)
1819 sctp_add_cmd_sf(commands, SCTP_CMD_ADAPTATION_IND, SCTP_NULL());
1820
1821 return SCTP_DISPOSITION_CONSUME;
1822
1823nomem:
1824 return SCTP_DISPOSITION_NOMEM;
1825}
1826
1827/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C')
1828 *
1829 * Section 5.2.4
1830 * C) In this case, the local endpoint's cookie has arrived late.
1831 * Before it arrived, the local endpoint sent an INIT and received an
1832 * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag
1833 * but a new tag of its own.
1834 */
1835/* This case represents an initialization collision. */
1836static sctp_disposition_t sctp_sf_do_dupcook_c(const struct sctp_endpoint *ep,
1837 const struct sctp_association *asoc,
1838 struct sctp_chunk *chunk,
1839 sctp_cmd_seq_t *commands,
1840 struct sctp_association *new_asoc)
1841{
1842 /* The cookie should be silently discarded.
1843 * The endpoint SHOULD NOT change states and should leave
1844 * any timers running.
1845 */
1846 return SCTP_DISPOSITION_DISCARD;
1847}
1848
1849/* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D')
1850 *
1851 * Section 5.2.4
1852 *
1853 * D) When both local and remote tags match the endpoint should always
1854 * enter the ESTABLISHED state, if it has not already done so.
1855 */
1856/* This case represents an initialization collision. */
1857static sctp_disposition_t sctp_sf_do_dupcook_d(const struct sctp_endpoint *ep,
1858 const struct sctp_association *asoc,
1859 struct sctp_chunk *chunk,
1860 sctp_cmd_seq_t *commands,
1861 struct sctp_association *new_asoc)
1862{
1863 struct sctp_ulpevent *ev = NULL, *ai_ev = NULL;
1864 struct sctp_chunk *repl;
1865
1866 /* Clarification from Implementor's Guide:
1867 * D) When both local and remote tags match the endpoint should
1868 * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state.
1869 * It should stop any cookie timer that may be running and send
1870 * a COOKIE ACK.
1871 */
1872
1873 /* Don't accidentally move back into established state. */
1874 if (asoc->state < SCTP_STATE_ESTABLISHED) {
1875 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1876 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1877 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1878 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1879 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
1880 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START,
1881 SCTP_NULL());
1882
1883 /* RFC 2960 5.1 Normal Establishment of an Association
1884 *
1885 * D) IMPLEMENTATION NOTE: An implementation may choose
1886 * to send the Communication Up notification to the
1887 * SCTP user upon reception of a valid COOKIE
1888 * ECHO chunk.
1889 */
1890 ev = sctp_ulpevent_make_assoc_change(asoc, 0,
1891 SCTP_COMM_UP, 0,
1892 asoc->c.sinit_num_ostreams,
1893 asoc->c.sinit_max_instreams,
1894 NULL, GFP_ATOMIC);
1895 if (!ev)
1896 goto nomem;
1897
1898 /* Sockets API Draft Section 5.3.1.6
1899 * When a peer sends a Adaptation Layer Indication parameter,
1900 * SCTP delivers this notification to inform the application
1901 * that of the peers requested adaptation layer.
1902 */
1903 if (asoc->peer.adaptation_ind) {
1904 ai_ev = sctp_ulpevent_make_adaptation_indication(asoc,
1905 GFP_ATOMIC);
1906 if (!ai_ev)
1907 goto nomem;
1908
1909 }
1910 }
1911
1912 repl = sctp_make_cookie_ack(new_asoc, chunk);
1913 if (!repl)
1914 goto nomem;
1915
1916 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1917
1918 if (ev)
1919 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1920 SCTP_ULPEVENT(ev));
1921 if (ai_ev)
1922 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1923 SCTP_ULPEVENT(ai_ev));
1924
1925 return SCTP_DISPOSITION_CONSUME;
1926
1927nomem:
1928 if (ai_ev)
1929 sctp_ulpevent_free(ai_ev);
1930 if (ev)
1931 sctp_ulpevent_free(ev);
1932 return SCTP_DISPOSITION_NOMEM;
1933}
1934
1935/*
1936 * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying
1937 * chunk was retransmitted and then delayed in the network.
1938 *
1939 * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists
1940 *
1941 * Verification Tag: None. Do cookie validation.
1942 *
1943 * Inputs
1944 * (endpoint, asoc, chunk)
1945 *
1946 * Outputs
1947 * (asoc, reply_msg, msg_up, timers, counters)
1948 *
1949 * The return value is the disposition of the chunk.
1950 */
1951sctp_disposition_t sctp_sf_do_5_2_4_dupcook(const struct sctp_endpoint *ep,
1952 const struct sctp_association *asoc,
1953 const sctp_subtype_t type,
1954 void *arg,
1955 sctp_cmd_seq_t *commands)
1956{
1957 sctp_disposition_t retval;
1958 struct sctp_chunk *chunk = arg;
1959 struct sctp_association *new_asoc;
1960 int error = 0;
1961 char action;
1962 struct sctp_chunk *err_chk_p;
1963
1964 /* Make sure that the chunk has a valid length from the protocol
1965 * perspective. In this case check to make sure we have at least
1966 * enough for the chunk header. Cookie length verification is
1967 * done later.
1968 */
1969 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
1970 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1971 commands);
1972
1973 /* "Decode" the chunk. We have no optional parameters so we
1974 * are in good shape.
1975 */
1976 chunk->subh.cookie_hdr = (struct sctp_signed_cookie *)chunk->skb->data;
1977 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
1978 sizeof(sctp_chunkhdr_t)))
1979 goto nomem;
1980
1981 /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
1982 * of a duplicate COOKIE ECHO match the Verification Tags of the
1983 * current association, consider the State Cookie valid even if
1984 * the lifespan is exceeded.
1985 */
1986 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
1987 &err_chk_p);
1988
1989 /* FIXME:
1990 * If the re-build failed, what is the proper error path
1991 * from here?
1992 *
1993 * [We should abort the association. --piggy]
1994 */
1995 if (!new_asoc) {
1996 /* FIXME: Several errors are possible. A bad cookie should
1997 * be silently discarded, but think about logging it too.
1998 */
1999 switch (error) {
2000 case -SCTP_IERROR_NOMEM:
2001 goto nomem;
2002
2003 case -SCTP_IERROR_STALE_COOKIE:
2004 sctp_send_stale_cookie_err(ep, asoc, chunk, commands,
2005 err_chk_p);
2006 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2007 case -SCTP_IERROR_BAD_SIG:
2008 default:
2009 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2010 }
2011 }
2012
2013 /* Compare the tie_tag in cookie with the verification tag of
2014 * current association.
2015 */
2016 action = sctp_tietags_compare(new_asoc, asoc);
2017
2018 switch (action) {
2019 case 'A': /* Association restart. */
2020 retval = sctp_sf_do_dupcook_a(ep, asoc, chunk, commands,
2021 new_asoc);
2022 break;
2023
2024 case 'B': /* Collision case B. */
2025 retval = sctp_sf_do_dupcook_b(ep, asoc, chunk, commands,
2026 new_asoc);
2027 break;
2028
2029 case 'C': /* Collision case C. */
2030 retval = sctp_sf_do_dupcook_c(ep, asoc, chunk, commands,
2031 new_asoc);
2032 break;
2033
2034 case 'D': /* Collision case D. */
2035 retval = sctp_sf_do_dupcook_d(ep, asoc, chunk, commands,
2036 new_asoc);
2037 break;
2038
2039 default: /* Discard packet for all others. */
2040 retval = sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2041 break;
2042 }
2043
2044 /* Delete the tempory new association. */
2045 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
2046 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
2047
2048 /* Restore association pointer to provide SCTP command interpeter
2049 * with a valid context in case it needs to manipulate
2050 * the queues */
2051 sctp_add_cmd_sf(commands, SCTP_CMD_SET_ASOC,
2052 SCTP_ASOC((struct sctp_association *)asoc));
2053
2054 return retval;
2055
2056nomem:
2057 return SCTP_DISPOSITION_NOMEM;
2058}
2059
2060/*
2061 * Process an ABORT. (SHUTDOWN-PENDING state)
2062 *
2063 * See sctp_sf_do_9_1_abort().
2064 */
2065sctp_disposition_t sctp_sf_shutdown_pending_abort(
2066 const struct sctp_endpoint *ep,
2067 const struct sctp_association *asoc,
2068 const sctp_subtype_t type,
2069 void *arg,
2070 sctp_cmd_seq_t *commands)
2071{
2072 struct sctp_chunk *chunk = arg;
2073
2074 if (!sctp_vtag_verify_either(chunk, asoc))
2075 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2076
2077 /* Make sure that the ABORT chunk has a valid length.
2078 * Since this is an ABORT chunk, we have to discard it
2079 * because of the following text:
2080 * RFC 2960, Section 3.3.7
2081 * If an endpoint receives an ABORT with a format error or for an
2082 * association that doesn't exist, it MUST silently discard it.
2083 * Because the length is "invalid", we can't really discard just
2084 * as we do not know its true length. So, to be safe, discard the
2085 * packet.
2086 */
2087 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2088 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2089
2090 /* ADD-IP: Special case for ABORT chunks
2091 * F4) One special consideration is that ABORT Chunks arriving
2092 * destined to the IP address being deleted MUST be
2093 * ignored (see Section 5.3.1 for further details).
2094 */
2095 if (SCTP_ADDR_DEL ==
2096 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2097 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
2098
2099 return __sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
2100}
2101
2102/*
2103 * Process an ABORT. (SHUTDOWN-SENT state)
2104 *
2105 * See sctp_sf_do_9_1_abort().
2106 */
2107sctp_disposition_t sctp_sf_shutdown_sent_abort(const struct sctp_endpoint *ep,
2108 const struct sctp_association *asoc,
2109 const sctp_subtype_t type,
2110 void *arg,
2111 sctp_cmd_seq_t *commands)
2112{
2113 struct sctp_chunk *chunk = arg;
2114
2115 if (!sctp_vtag_verify_either(chunk, asoc))
2116 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2117
2118 /* Make sure that the ABORT chunk has a valid length.
2119 * Since this is an ABORT chunk, we have to discard it
2120 * because of the following text:
2121 * RFC 2960, Section 3.3.7
2122 * If an endpoint receives an ABORT with a format error or for an
2123 * association that doesn't exist, it MUST silently discard it.
2124 * Because the length is "invalid", we can't really discard just
2125 * as we do not know its true length. So, to be safe, discard the
2126 * packet.
2127 */
2128 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2129 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2130
2131 /* ADD-IP: Special case for ABORT chunks
2132 * F4) One special consideration is that ABORT Chunks arriving
2133 * destined to the IP address being deleted MUST be
2134 * ignored (see Section 5.3.1 for further details).
2135 */
2136 if (SCTP_ADDR_DEL ==
2137 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2138 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
2139
2140 /* Stop the T2-shutdown timer. */
2141 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2142 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2143
2144 /* Stop the T5-shutdown guard timer. */
2145 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2146 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
2147
2148 return __sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
2149}
2150
2151/*
2152 * Process an ABORT. (SHUTDOWN-ACK-SENT state)
2153 *
2154 * See sctp_sf_do_9_1_abort().
2155 */
2156sctp_disposition_t sctp_sf_shutdown_ack_sent_abort(
2157 const struct sctp_endpoint *ep,
2158 const struct sctp_association *asoc,
2159 const sctp_subtype_t type,
2160 void *arg,
2161 sctp_cmd_seq_t *commands)
2162{
2163 /* The same T2 timer, so we should be able to use
2164 * common function with the SHUTDOWN-SENT state.
2165 */
2166 return sctp_sf_shutdown_sent_abort(ep, asoc, type, arg, commands);
2167}
2168
2169/*
2170 * Handle an Error received in COOKIE_ECHOED state.
2171 *
2172 * Only handle the error type of stale COOKIE Error, the other errors will
2173 * be ignored.
2174 *
2175 * Inputs
2176 * (endpoint, asoc, chunk)
2177 *
2178 * Outputs
2179 * (asoc, reply_msg, msg_up, timers, counters)
2180 *
2181 * The return value is the disposition of the chunk.
2182 */
2183sctp_disposition_t sctp_sf_cookie_echoed_err(const struct sctp_endpoint *ep,
2184 const struct sctp_association *asoc,
2185 const sctp_subtype_t type,
2186 void *arg,
2187 sctp_cmd_seq_t *commands)
2188{
2189 struct sctp_chunk *chunk = arg;
2190 sctp_errhdr_t *err;
2191
2192 if (!sctp_vtag_verify(chunk, asoc))
2193 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2194
2195 /* Make sure that the ERROR chunk has a valid length.
2196 * The parameter walking depends on this as well.
2197 */
2198 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
2199 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2200 commands);
2201
2202 /* Process the error here */
2203 /* FUTURE FIXME: When PR-SCTP related and other optional
2204 * parms are emitted, this will have to change to handle multiple
2205 * errors.
2206 */
2207 sctp_walk_errors(err, chunk->chunk_hdr) {
2208 if (SCTP_ERROR_STALE_COOKIE == err->cause)
2209 return sctp_sf_do_5_2_6_stale(ep, asoc, type,
2210 arg, commands);
2211 }
2212
2213 /* It is possible to have malformed error causes, and that
2214 * will cause us to end the walk early. However, since
2215 * we are discarding the packet, there should be no adverse
2216 * affects.
2217 */
2218 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2219}
2220
2221/*
2222 * Handle a Stale COOKIE Error
2223 *
2224 * Section: 5.2.6 Handle Stale COOKIE Error
2225 * If the association is in the COOKIE-ECHOED state, the endpoint may elect
2226 * one of the following three alternatives.
2227 * ...
2228 * 3) Send a new INIT chunk to the endpoint, adding a Cookie
2229 * Preservative parameter requesting an extension to the lifetime of
2230 * the State Cookie. When calculating the time extension, an
2231 * implementation SHOULD use the RTT information measured based on the
2232 * previous COOKIE ECHO / ERROR exchange, and should add no more
2233 * than 1 second beyond the measured RTT, due to long State Cookie
2234 * lifetimes making the endpoint more subject to a replay attack.
2235 *
2236 * Verification Tag: Not explicit, but safe to ignore.
2237 *
2238 * Inputs
2239 * (endpoint, asoc, chunk)
2240 *
2241 * Outputs
2242 * (asoc, reply_msg, msg_up, timers, counters)
2243 *
2244 * The return value is the disposition of the chunk.
2245 */
2246static sctp_disposition_t sctp_sf_do_5_2_6_stale(const struct sctp_endpoint *ep,
2247 const struct sctp_association *asoc,
2248 const sctp_subtype_t type,
2249 void *arg,
2250 sctp_cmd_seq_t *commands)
2251{
2252 struct sctp_chunk *chunk = arg;
2253 time_t stale;
2254 sctp_cookie_preserve_param_t bht;
2255 sctp_errhdr_t *err;
2256 struct sctp_chunk *reply;
2257 struct sctp_bind_addr *bp;
2258 int attempts = asoc->init_err_counter + 1;
2259
2260 if (attempts > asoc->max_init_attempts) {
2261 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
2262 SCTP_ERROR(ETIMEDOUT));
2263 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
2264 SCTP_PERR(SCTP_ERROR_STALE_COOKIE));
2265 return SCTP_DISPOSITION_DELETE_TCB;
2266 }
2267
2268 err = (sctp_errhdr_t *)(chunk->skb->data);
2269
2270 /* When calculating the time extension, an implementation
2271 * SHOULD use the RTT information measured based on the
2272 * previous COOKIE ECHO / ERROR exchange, and should add no
2273 * more than 1 second beyond the measured RTT, due to long
2274 * State Cookie lifetimes making the endpoint more subject to
2275 * a replay attack.
2276 * Measure of Staleness's unit is usec. (1/1000000 sec)
2277 * Suggested Cookie Life-span Increment's unit is msec.
2278 * (1/1000 sec)
2279 * In general, if you use the suggested cookie life, the value
2280 * found in the field of measure of staleness should be doubled
2281 * to give ample time to retransmit the new cookie and thus
2282 * yield a higher probability of success on the reattempt.
2283 */
2284 stale = ntohl(*(__be32 *)((u8 *)err + sizeof(sctp_errhdr_t)));
2285 stale = (stale * 2) / 1000;
2286
2287 bht.param_hdr.type = SCTP_PARAM_COOKIE_PRESERVATIVE;
2288 bht.param_hdr.length = htons(sizeof(bht));
2289 bht.lifespan_increment = htonl(stale);
2290
2291 /* Build that new INIT chunk. */
2292 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
2293 reply = sctp_make_init(asoc, bp, GFP_ATOMIC, sizeof(bht));
2294 if (!reply)
2295 goto nomem;
2296
2297 sctp_addto_chunk(reply, sizeof(bht), &bht);
2298
2299 /* Clear peer's init_tag cached in assoc as we are sending a new INIT */
2300 sctp_add_cmd_sf(commands, SCTP_CMD_CLEAR_INIT_TAG, SCTP_NULL());
2301
2302 /* Stop pending T3-rtx and heartbeat timers */
2303 sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
2304 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
2305
2306 /* Delete non-primary peer ip addresses since we are transitioning
2307 * back to the COOKIE-WAIT state
2308 */
2309 sctp_add_cmd_sf(commands, SCTP_CMD_DEL_NON_PRIMARY, SCTP_NULL());
2310
2311 /* If we've sent any data bundled with COOKIE-ECHO we will need to
2312 * resend
2313 */
2314 sctp_add_cmd_sf(commands, SCTP_CMD_T1_RETRAN,
2315 SCTP_TRANSPORT(asoc->peer.primary_path));
2316
2317 /* Cast away the const modifier, as we want to just
2318 * rerun it through as a sideffect.
2319 */
2320 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_INC, SCTP_NULL());
2321
2322 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2323 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
2324 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2325 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
2326 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
2327 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
2328
2329 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2330
2331 return SCTP_DISPOSITION_CONSUME;
2332
2333nomem:
2334 return SCTP_DISPOSITION_NOMEM;
2335}
2336
2337/*
2338 * Process an ABORT.
2339 *
2340 * Section: 9.1
2341 * After checking the Verification Tag, the receiving endpoint shall
2342 * remove the association from its record, and shall report the
2343 * termination to its upper layer.
2344 *
2345 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
2346 * B) Rules for packet carrying ABORT:
2347 *
2348 * - The endpoint shall always fill in the Verification Tag field of the
2349 * outbound packet with the destination endpoint's tag value if it
2350 * is known.
2351 *
2352 * - If the ABORT is sent in response to an OOTB packet, the endpoint
2353 * MUST follow the procedure described in Section 8.4.
2354 *
2355 * - The receiver MUST accept the packet if the Verification Tag
2356 * matches either its own tag, OR the tag of its peer. Otherwise, the
2357 * receiver MUST silently discard the packet and take no further
2358 * action.
2359 *
2360 * Inputs
2361 * (endpoint, asoc, chunk)
2362 *
2363 * Outputs
2364 * (asoc, reply_msg, msg_up, timers, counters)
2365 *
2366 * The return value is the disposition of the chunk.
2367 */
2368sctp_disposition_t sctp_sf_do_9_1_abort(const struct sctp_endpoint *ep,
2369 const struct sctp_association *asoc,
2370 const sctp_subtype_t type,
2371 void *arg,
2372 sctp_cmd_seq_t *commands)
2373{
2374 struct sctp_chunk *chunk = arg;
2375
2376 if (!sctp_vtag_verify_either(chunk, asoc))
2377 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2378
2379 /* Make sure that the ABORT chunk has a valid length.
2380 * Since this is an ABORT chunk, we have to discard it
2381 * because of the following text:
2382 * RFC 2960, Section 3.3.7
2383 * If an endpoint receives an ABORT with a format error or for an
2384 * association that doesn't exist, it MUST silently discard it.
2385 * Because the length is "invalid", we can't really discard just
2386 * as we do not know its true length. So, to be safe, discard the
2387 * packet.
2388 */
2389 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2390 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2391
2392 /* ADD-IP: Special case for ABORT chunks
2393 * F4) One special consideration is that ABORT Chunks arriving
2394 * destined to the IP address being deleted MUST be
2395 * ignored (see Section 5.3.1 for further details).
2396 */
2397 if (SCTP_ADDR_DEL ==
2398 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2399 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
2400
2401 return __sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
2402}
2403
2404static sctp_disposition_t __sctp_sf_do_9_1_abort(const struct sctp_endpoint *ep,
2405 const struct sctp_association *asoc,
2406 const sctp_subtype_t type,
2407 void *arg,
2408 sctp_cmd_seq_t *commands)
2409{
2410 struct sctp_chunk *chunk = arg;
2411 unsigned int len;
2412 __be16 error = SCTP_ERROR_NO_ERROR;
2413
2414 /* See if we have an error cause code in the chunk. */
2415 len = ntohs(chunk->chunk_hdr->length);
2416 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr)) {
2417
2418 sctp_errhdr_t *err;
2419 sctp_walk_errors(err, chunk->chunk_hdr);
2420 if ((void *)err != (void *)chunk->chunk_end)
2421 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2422
2423 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2424 }
2425
2426 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNRESET));
2427 /* ASSOC_FAILED will DELETE_TCB. */
2428 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, SCTP_PERR(error));
2429 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
2430 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
2431
2432 return SCTP_DISPOSITION_ABORT;
2433}
2434
2435/*
2436 * Process an ABORT. (COOKIE-WAIT state)
2437 *
2438 * See sctp_sf_do_9_1_abort() above.
2439 */
2440sctp_disposition_t sctp_sf_cookie_wait_abort(const struct sctp_endpoint *ep,
2441 const struct sctp_association *asoc,
2442 const sctp_subtype_t type,
2443 void *arg,
2444 sctp_cmd_seq_t *commands)
2445{
2446 struct sctp_chunk *chunk = arg;
2447 unsigned int len;
2448 __be16 error = SCTP_ERROR_NO_ERROR;
2449
2450 if (!sctp_vtag_verify_either(chunk, asoc))
2451 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2452
2453 /* Make sure that the ABORT chunk has a valid length.
2454 * Since this is an ABORT chunk, we have to discard it
2455 * because of the following text:
2456 * RFC 2960, Section 3.3.7
2457 * If an endpoint receives an ABORT with a format error or for an
2458 * association that doesn't exist, it MUST silently discard it.
2459 * Because the length is "invalid", we can't really discard just
2460 * as we do not know its true length. So, to be safe, discard the
2461 * packet.
2462 */
2463 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2464 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2465
2466 /* See if we have an error cause code in the chunk. */
2467 len = ntohs(chunk->chunk_hdr->length);
2468 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
2469 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2470
2471 return sctp_stop_t1_and_abort(commands, error, ECONNREFUSED, asoc,
2472 chunk->transport);
2473}
2474
2475/*
2476 * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state)
2477 */
2478sctp_disposition_t sctp_sf_cookie_wait_icmp_abort(const struct sctp_endpoint *ep,
2479 const struct sctp_association *asoc,
2480 const sctp_subtype_t type,
2481 void *arg,
2482 sctp_cmd_seq_t *commands)
2483{
2484 return sctp_stop_t1_and_abort(commands, SCTP_ERROR_NO_ERROR,
2485 ENOPROTOOPT, asoc,
2486 (struct sctp_transport *)arg);
2487}
2488
2489/*
2490 * Process an ABORT. (COOKIE-ECHOED state)
2491 */
2492sctp_disposition_t sctp_sf_cookie_echoed_abort(const struct sctp_endpoint *ep,
2493 const struct sctp_association *asoc,
2494 const sctp_subtype_t type,
2495 void *arg,
2496 sctp_cmd_seq_t *commands)
2497{
2498 /* There is a single T1 timer, so we should be able to use
2499 * common function with the COOKIE-WAIT state.
2500 */
2501 return sctp_sf_cookie_wait_abort(ep, asoc, type, arg, commands);
2502}
2503
2504/*
2505 * Stop T1 timer and abort association with "INIT failed".
2506 *
2507 * This is common code called by several sctp_sf_*_abort() functions above.
2508 */
2509static sctp_disposition_t sctp_stop_t1_and_abort(sctp_cmd_seq_t *commands,
2510 __be16 error, int sk_err,
2511 const struct sctp_association *asoc,
2512 struct sctp_transport *transport)
2513{
2514 SCTP_DEBUG_PRINTK("ABORT received (INIT).\n");
2515 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2516 SCTP_STATE(SCTP_STATE_CLOSED));
2517 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
2518 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2519 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
2520 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(sk_err));
2521 /* CMD_INIT_FAILED will DELETE_TCB. */
2522 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
2523 SCTP_PERR(error));
2524 return SCTP_DISPOSITION_ABORT;
2525}
2526
2527/*
2528 * sctp_sf_do_9_2_shut
2529 *
2530 * Section: 9.2
2531 * Upon the reception of the SHUTDOWN, the peer endpoint shall
2532 * - enter the SHUTDOWN-RECEIVED state,
2533 *
2534 * - stop accepting new data from its SCTP user
2535 *
2536 * - verify, by checking the Cumulative TSN Ack field of the chunk,
2537 * that all its outstanding DATA chunks have been received by the
2538 * SHUTDOWN sender.
2539 *
2540 * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT
2541 * send a SHUTDOWN in response to a ULP request. And should discard
2542 * subsequent SHUTDOWN chunks.
2543 *
2544 * If there are still outstanding DATA chunks left, the SHUTDOWN
2545 * receiver shall continue to follow normal data transmission
2546 * procedures defined in Section 6 until all outstanding DATA chunks
2547 * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept
2548 * new data from its SCTP user.
2549 *
2550 * Verification Tag: 8.5 Verification Tag [Normal verification]
2551 *
2552 * Inputs
2553 * (endpoint, asoc, chunk)
2554 *
2555 * Outputs
2556 * (asoc, reply_msg, msg_up, timers, counters)
2557 *
2558 * The return value is the disposition of the chunk.
2559 */
2560sctp_disposition_t sctp_sf_do_9_2_shutdown(const struct sctp_endpoint *ep,
2561 const struct sctp_association *asoc,
2562 const sctp_subtype_t type,
2563 void *arg,
2564 sctp_cmd_seq_t *commands)
2565{
2566 struct sctp_chunk *chunk = arg;
2567 sctp_shutdownhdr_t *sdh;
2568 sctp_disposition_t disposition;
2569 struct sctp_ulpevent *ev;
2570 __u32 ctsn;
2571
2572 if (!sctp_vtag_verify(chunk, asoc))
2573 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2574
2575 /* Make sure that the SHUTDOWN chunk has a valid length. */
2576 if (!sctp_chunk_length_valid(chunk,
2577 sizeof(struct sctp_shutdown_chunk_t)))
2578 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2579 commands);
2580
2581 /* Convert the elaborate header. */
2582 sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
2583 skb_pull(chunk->skb, sizeof(sctp_shutdownhdr_t));
2584 chunk->subh.shutdown_hdr = sdh;
2585 ctsn = ntohl(sdh->cum_tsn_ack);
2586
2587 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
2588 SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn);
2589 SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc->ctsn_ack_point);
2590 return SCTP_DISPOSITION_DISCARD;
2591 }
2592
2593 /* If Cumulative TSN Ack beyond the max tsn currently
2594 * send, terminating the association and respond to the
2595 * sender with an ABORT.
2596 */
2597 if (!TSN_lt(ctsn, asoc->next_tsn))
2598 return sctp_sf_violation_ctsn(ep, asoc, type, arg, commands);
2599
2600 /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT
2601 * When a peer sends a SHUTDOWN, SCTP delivers this notification to
2602 * inform the application that it should cease sending data.
2603 */
2604 ev = sctp_ulpevent_make_shutdown_event(asoc, 0, GFP_ATOMIC);
2605 if (!ev) {
2606 disposition = SCTP_DISPOSITION_NOMEM;
2607 goto out;
2608 }
2609 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
2610
2611 /* Upon the reception of the SHUTDOWN, the peer endpoint shall
2612 * - enter the SHUTDOWN-RECEIVED state,
2613 * - stop accepting new data from its SCTP user
2614 *
2615 * [This is implicit in the new state.]
2616 */
2617 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2618 SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED));
2619 disposition = SCTP_DISPOSITION_CONSUME;
2620
2621 if (sctp_outq_is_empty(&asoc->outqueue)) {
2622 disposition = sctp_sf_do_9_2_shutdown_ack(ep, asoc, type,
2623 arg, commands);
2624 }
2625
2626 if (SCTP_DISPOSITION_NOMEM == disposition)
2627 goto out;
2628
2629 /* - verify, by checking the Cumulative TSN Ack field of the
2630 * chunk, that all its outstanding DATA chunks have been
2631 * received by the SHUTDOWN sender.
2632 */
2633 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
2634 SCTP_BE32(chunk->subh.shutdown_hdr->cum_tsn_ack));
2635
2636out:
2637 return disposition;
2638}
2639
2640/*
2641 * sctp_sf_do_9_2_shut_ctsn
2642 *
2643 * Once an endpoint has reached the SHUTDOWN-RECEIVED state,
2644 * it MUST NOT send a SHUTDOWN in response to a ULP request.
2645 * The Cumulative TSN Ack of the received SHUTDOWN chunk
2646 * MUST be processed.
2647 */
2648sctp_disposition_t sctp_sf_do_9_2_shut_ctsn(const struct sctp_endpoint *ep,
2649 const struct sctp_association *asoc,
2650 const sctp_subtype_t type,
2651 void *arg,
2652 sctp_cmd_seq_t *commands)
2653{
2654 struct sctp_chunk *chunk = arg;
2655 sctp_shutdownhdr_t *sdh;
2656 __u32 ctsn;
2657
2658 if (!sctp_vtag_verify(chunk, asoc))
2659 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2660
2661 /* Make sure that the SHUTDOWN chunk has a valid length. */
2662 if (!sctp_chunk_length_valid(chunk,
2663 sizeof(struct sctp_shutdown_chunk_t)))
2664 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2665 commands);
2666
2667 sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
2668 ctsn = ntohl(sdh->cum_tsn_ack);
2669
2670 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
2671 SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn);
2672 SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc->ctsn_ack_point);
2673 return SCTP_DISPOSITION_DISCARD;
2674 }
2675
2676 /* If Cumulative TSN Ack beyond the max tsn currently
2677 * send, terminating the association and respond to the
2678 * sender with an ABORT.
2679 */
2680 if (!TSN_lt(ctsn, asoc->next_tsn))
2681 return sctp_sf_violation_ctsn(ep, asoc, type, arg, commands);
2682
2683 /* verify, by checking the Cumulative TSN Ack field of the
2684 * chunk, that all its outstanding DATA chunks have been
2685 * received by the SHUTDOWN sender.
2686 */
2687 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
2688 SCTP_BE32(sdh->cum_tsn_ack));
2689
2690 return SCTP_DISPOSITION_CONSUME;
2691}
2692
2693/* RFC 2960 9.2
2694 * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk
2695 * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination
2696 * transport addresses (either in the IP addresses or in the INIT chunk)
2697 * that belong to this association, it should discard the INIT chunk and
2698 * retransmit the SHUTDOWN ACK chunk.
2699 */
2700sctp_disposition_t sctp_sf_do_9_2_reshutack(const struct sctp_endpoint *ep,
2701 const struct sctp_association *asoc,
2702 const sctp_subtype_t type,
2703 void *arg,
2704 sctp_cmd_seq_t *commands)
2705{
2706 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
2707 struct sctp_chunk *reply;
2708
2709 /* Make sure that the chunk has a valid length */
2710 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
2711 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2712 commands);
2713
2714 /* Since we are not going to really process this INIT, there
2715 * is no point in verifying chunk boundries. Just generate
2716 * the SHUTDOWN ACK.
2717 */
2718 reply = sctp_make_shutdown_ack(asoc, chunk);
2719 if (NULL == reply)
2720 goto nomem;
2721
2722 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
2723 * the T2-SHUTDOWN timer.
2724 */
2725 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
2726
2727 /* and restart the T2-shutdown timer. */
2728 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2729 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2730
2731 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2732
2733 return SCTP_DISPOSITION_CONSUME;
2734nomem:
2735 return SCTP_DISPOSITION_NOMEM;
2736}
2737
2738/*
2739 * sctp_sf_do_ecn_cwr
2740 *
2741 * Section: Appendix A: Explicit Congestion Notification
2742 *
2743 * CWR:
2744 *
2745 * RFC 2481 details a specific bit for a sender to send in the header of
2746 * its next outbound TCP segment to indicate to its peer that it has
2747 * reduced its congestion window. This is termed the CWR bit. For
2748 * SCTP the same indication is made by including the CWR chunk.
2749 * This chunk contains one data element, i.e. the TSN number that
2750 * was sent in the ECNE chunk. This element represents the lowest
2751 * TSN number in the datagram that was originally marked with the
2752 * CE bit.
2753 *
2754 * Verification Tag: 8.5 Verification Tag [Normal verification]
2755 * Inputs
2756 * (endpoint, asoc, chunk)
2757 *
2758 * Outputs
2759 * (asoc, reply_msg, msg_up, timers, counters)
2760 *
2761 * The return value is the disposition of the chunk.
2762 */
2763sctp_disposition_t sctp_sf_do_ecn_cwr(const struct sctp_endpoint *ep,
2764 const struct sctp_association *asoc,
2765 const sctp_subtype_t type,
2766 void *arg,
2767 sctp_cmd_seq_t *commands)
2768{
2769 sctp_cwrhdr_t *cwr;
2770 struct sctp_chunk *chunk = arg;
2771 u32 lowest_tsn;
2772
2773 if (!sctp_vtag_verify(chunk, asoc))
2774 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2775
2776 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2777 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2778 commands);
2779
2780 cwr = (sctp_cwrhdr_t *) chunk->skb->data;
2781 skb_pull(chunk->skb, sizeof(sctp_cwrhdr_t));
2782
2783 lowest_tsn = ntohl(cwr->lowest_tsn);
2784
2785 /* Does this CWR ack the last sent congestion notification? */
2786 if (TSN_lte(asoc->last_ecne_tsn, lowest_tsn)) {
2787 /* Stop sending ECNE. */
2788 sctp_add_cmd_sf(commands,
2789 SCTP_CMD_ECN_CWR,
2790 SCTP_U32(lowest_tsn));
2791 }
2792 return SCTP_DISPOSITION_CONSUME;
2793}
2794
2795/*
2796 * sctp_sf_do_ecne
2797 *
2798 * Section: Appendix A: Explicit Congestion Notification
2799 *
2800 * ECN-Echo
2801 *
2802 * RFC 2481 details a specific bit for a receiver to send back in its
2803 * TCP acknowledgements to notify the sender of the Congestion
2804 * Experienced (CE) bit having arrived from the network. For SCTP this
2805 * same indication is made by including the ECNE chunk. This chunk
2806 * contains one data element, i.e. the lowest TSN associated with the IP
2807 * datagram marked with the CE bit.....
2808 *
2809 * Verification Tag: 8.5 Verification Tag [Normal verification]
2810 * Inputs
2811 * (endpoint, asoc, chunk)
2812 *
2813 * Outputs
2814 * (asoc, reply_msg, msg_up, timers, counters)
2815 *
2816 * The return value is the disposition of the chunk.
2817 */
2818sctp_disposition_t sctp_sf_do_ecne(const struct sctp_endpoint *ep,
2819 const struct sctp_association *asoc,
2820 const sctp_subtype_t type,
2821 void *arg,
2822 sctp_cmd_seq_t *commands)
2823{
2824 sctp_ecnehdr_t *ecne;
2825 struct sctp_chunk *chunk = arg;
2826
2827 if (!sctp_vtag_verify(chunk, asoc))
2828 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2829
2830 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2831 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2832 commands);
2833
2834 ecne = (sctp_ecnehdr_t *) chunk->skb->data;
2835 skb_pull(chunk->skb, sizeof(sctp_ecnehdr_t));
2836
2837 /* If this is a newer ECNE than the last CWR packet we sent out */
2838 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_ECNE,
2839 SCTP_U32(ntohl(ecne->lowest_tsn)));
2840
2841 return SCTP_DISPOSITION_CONSUME;
2842}
2843
2844/*
2845 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
2846 *
2847 * The SCTP endpoint MUST always acknowledge the reception of each valid
2848 * DATA chunk.
2849 *
2850 * The guidelines on delayed acknowledgement algorithm specified in
2851 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
2852 * acknowledgement SHOULD be generated for at least every second packet
2853 * (not every second DATA chunk) received, and SHOULD be generated within
2854 * 200 ms of the arrival of any unacknowledged DATA chunk. In some
2855 * situations it may be beneficial for an SCTP transmitter to be more
2856 * conservative than the algorithms detailed in this document allow.
2857 * However, an SCTP transmitter MUST NOT be more aggressive than the
2858 * following algorithms allow.
2859 *
2860 * A SCTP receiver MUST NOT generate more than one SACK for every
2861 * incoming packet, other than to update the offered window as the
2862 * receiving application consumes new data.
2863 *
2864 * Verification Tag: 8.5 Verification Tag [Normal verification]
2865 *
2866 * Inputs
2867 * (endpoint, asoc, chunk)
2868 *
2869 * Outputs
2870 * (asoc, reply_msg, msg_up, timers, counters)
2871 *
2872 * The return value is the disposition of the chunk.
2873 */
2874sctp_disposition_t sctp_sf_eat_data_6_2(const struct sctp_endpoint *ep,
2875 const struct sctp_association *asoc,
2876 const sctp_subtype_t type,
2877 void *arg,
2878 sctp_cmd_seq_t *commands)
2879{
2880 struct sctp_chunk *chunk = arg;
2881 sctp_arg_t force = SCTP_NOFORCE();
2882 int error;
2883
2884 if (!sctp_vtag_verify(chunk, asoc)) {
2885 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
2886 SCTP_NULL());
2887 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2888 }
2889
2890 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
2891 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2892 commands);
2893
2894 error = sctp_eat_data(asoc, chunk, commands );
2895 switch (error) {
2896 case SCTP_IERROR_NO_ERROR:
2897 break;
2898 case SCTP_IERROR_HIGH_TSN:
2899 case SCTP_IERROR_BAD_STREAM:
2900 SCTP_INC_STATS(SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
2901 goto discard_noforce;
2902 case SCTP_IERROR_DUP_TSN:
2903 case SCTP_IERROR_IGNORE_TSN:
2904 SCTP_INC_STATS(SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
2905 goto discard_force;
2906 case SCTP_IERROR_NO_DATA:
2907 goto consume;
2908 case SCTP_IERROR_PROTO_VIOLATION:
2909 return sctp_sf_abort_violation(ep, asoc, chunk, commands,
2910 (u8 *)chunk->subh.data_hdr, sizeof(sctp_datahdr_t));
2911 default:
2912 BUG();
2913 }
2914
2915 if (chunk->chunk_hdr->flags & SCTP_DATA_SACK_IMM)
2916 force = SCTP_FORCE();
2917
2918 if (asoc->autoclose) {
2919 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2920 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
2921 }
2922
2923 /* If this is the last chunk in a packet, we need to count it
2924 * toward sack generation. Note that we need to SACK every
2925 * OTHER packet containing data chunks, EVEN IF WE DISCARD
2926 * THEM. We elect to NOT generate SACK's if the chunk fails
2927 * the verification tag test.
2928 *
2929 * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2930 *
2931 * The SCTP endpoint MUST always acknowledge the reception of
2932 * each valid DATA chunk.
2933 *
2934 * The guidelines on delayed acknowledgement algorithm
2935 * specified in Section 4.2 of [RFC2581] SHOULD be followed.
2936 * Specifically, an acknowledgement SHOULD be generated for at
2937 * least every second packet (not every second DATA chunk)
2938 * received, and SHOULD be generated within 200 ms of the
2939 * arrival of any unacknowledged DATA chunk. In some
2940 * situations it may be beneficial for an SCTP transmitter to
2941 * be more conservative than the algorithms detailed in this
2942 * document allow. However, an SCTP transmitter MUST NOT be
2943 * more aggressive than the following algorithms allow.
2944 */
2945 if (chunk->end_of_packet)
2946 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force);
2947
2948 return SCTP_DISPOSITION_CONSUME;
2949
2950discard_force:
2951 /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2952 *
2953 * When a packet arrives with duplicate DATA chunk(s) and with
2954 * no new DATA chunk(s), the endpoint MUST immediately send a
2955 * SACK with no delay. If a packet arrives with duplicate
2956 * DATA chunk(s) bundled with new DATA chunks, the endpoint
2957 * MAY immediately send a SACK. Normally receipt of duplicate
2958 * DATA chunks will occur when the original SACK chunk was lost
2959 * and the peer's RTO has expired. The duplicate TSN number(s)
2960 * SHOULD be reported in the SACK as duplicate.
2961 */
2962 /* In our case, we split the MAY SACK advice up whether or not
2963 * the last chunk is a duplicate.'
2964 */
2965 if (chunk->end_of_packet)
2966 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
2967 return SCTP_DISPOSITION_DISCARD;
2968
2969discard_noforce:
2970 if (chunk->end_of_packet)
2971 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force);
2972
2973 return SCTP_DISPOSITION_DISCARD;
2974consume:
2975 return SCTP_DISPOSITION_CONSUME;
2976
2977}
2978
2979/*
2980 * sctp_sf_eat_data_fast_4_4
2981 *
2982 * Section: 4 (4)
2983 * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received
2984 * DATA chunks without delay.
2985 *
2986 * Verification Tag: 8.5 Verification Tag [Normal verification]
2987 * Inputs
2988 * (endpoint, asoc, chunk)
2989 *
2990 * Outputs
2991 * (asoc, reply_msg, msg_up, timers, counters)
2992 *
2993 * The return value is the disposition of the chunk.
2994 */
2995sctp_disposition_t sctp_sf_eat_data_fast_4_4(const struct sctp_endpoint *ep,
2996 const struct sctp_association *asoc,
2997 const sctp_subtype_t type,
2998 void *arg,
2999 sctp_cmd_seq_t *commands)
3000{
3001 struct sctp_chunk *chunk = arg;
3002 int error;
3003
3004 if (!sctp_vtag_verify(chunk, asoc)) {
3005 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3006 SCTP_NULL());
3007 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3008 }
3009
3010 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
3011 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3012 commands);
3013
3014 error = sctp_eat_data(asoc, chunk, commands );
3015 switch (error) {
3016 case SCTP_IERROR_NO_ERROR:
3017 case SCTP_IERROR_HIGH_TSN:
3018 case SCTP_IERROR_DUP_TSN:
3019 case SCTP_IERROR_IGNORE_TSN:
3020 case SCTP_IERROR_BAD_STREAM:
3021 break;
3022 case SCTP_IERROR_NO_DATA:
3023 goto consume;
3024 case SCTP_IERROR_PROTO_VIOLATION:
3025 return sctp_sf_abort_violation(ep, asoc, chunk, commands,
3026 (u8 *)chunk->subh.data_hdr, sizeof(sctp_datahdr_t));
3027 default:
3028 BUG();
3029 }
3030
3031 /* Go a head and force a SACK, since we are shutting down. */
3032
3033 /* Implementor's Guide.
3034 *
3035 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3036 * respond to each received packet containing one or more DATA chunk(s)
3037 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3038 */
3039 if (chunk->end_of_packet) {
3040 /* We must delay the chunk creation since the cumulative
3041 * TSN has not been updated yet.
3042 */
3043 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
3044 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3045 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3046 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3047 }
3048
3049consume:
3050 return SCTP_DISPOSITION_CONSUME;
3051}
3052
3053/*
3054 * Section: 6.2 Processing a Received SACK
3055 * D) Any time a SACK arrives, the endpoint performs the following:
3056 *
3057 * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point,
3058 * then drop the SACK. Since Cumulative TSN Ack is monotonically
3059 * increasing, a SACK whose Cumulative TSN Ack is less than the
3060 * Cumulative TSN Ack Point indicates an out-of-order SACK.
3061 *
3062 * ii) Set rwnd equal to the newly received a_rwnd minus the number
3063 * of bytes still outstanding after processing the Cumulative TSN Ack
3064 * and the Gap Ack Blocks.
3065 *
3066 * iii) If the SACK is missing a TSN that was previously
3067 * acknowledged via a Gap Ack Block (e.g., the data receiver
3068 * reneged on the data), then mark the corresponding DATA chunk
3069 * as available for retransmit: Mark it as missing for fast
3070 * retransmit as described in Section 7.2.4 and if no retransmit
3071 * timer is running for the destination address to which the DATA
3072 * chunk was originally transmitted, then T3-rtx is started for
3073 * that destination address.
3074 *
3075 * Verification Tag: 8.5 Verification Tag [Normal verification]
3076 *
3077 * Inputs
3078 * (endpoint, asoc, chunk)
3079 *
3080 * Outputs
3081 * (asoc, reply_msg, msg_up, timers, counters)
3082 *
3083 * The return value is the disposition of the chunk.
3084 */
3085sctp_disposition_t sctp_sf_eat_sack_6_2(const struct sctp_endpoint *ep,
3086 const struct sctp_association *asoc,
3087 const sctp_subtype_t type,
3088 void *arg,
3089 sctp_cmd_seq_t *commands)
3090{
3091 struct sctp_chunk *chunk = arg;
3092 sctp_sackhdr_t *sackh;
3093 __u32 ctsn;
3094
3095 if (!sctp_vtag_verify(chunk, asoc))
3096 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3097
3098 /* Make sure that the SACK chunk has a valid length. */
3099 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_sack_chunk_t)))
3100 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3101 commands);
3102
3103 /* Pull the SACK chunk from the data buffer */
3104 sackh = sctp_sm_pull_sack(chunk);
3105 /* Was this a bogus SACK? */
3106 if (!sackh)
3107 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3108 chunk->subh.sack_hdr = sackh;
3109 ctsn = ntohl(sackh->cum_tsn_ack);
3110
3111 /* i) If Cumulative TSN Ack is less than the Cumulative TSN
3112 * Ack Point, then drop the SACK. Since Cumulative TSN
3113 * Ack is monotonically increasing, a SACK whose
3114 * Cumulative TSN Ack is less than the Cumulative TSN Ack
3115 * Point indicates an out-of-order SACK.
3116 */
3117 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
3118 SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn);
3119 SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc->ctsn_ack_point);
3120 return SCTP_DISPOSITION_DISCARD;
3121 }
3122
3123 /* If Cumulative TSN Ack beyond the max tsn currently
3124 * send, terminating the association and respond to the
3125 * sender with an ABORT.
3126 */
3127 if (!TSN_lt(ctsn, asoc->next_tsn))
3128 return sctp_sf_violation_ctsn(ep, asoc, type, arg, commands);
3129
3130 /* Return this SACK for further processing. */
3131 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_SACKH(sackh));
3132
3133 /* Note: We do the rest of the work on the PROCESS_SACK
3134 * sideeffect.
3135 */
3136 return SCTP_DISPOSITION_CONSUME;
3137}
3138
3139/*
3140 * Generate an ABORT in response to a packet.
3141 *
3142 * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41
3143 *
3144 * 8) The receiver should respond to the sender of the OOTB packet with
3145 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3146 * MUST fill in the Verification Tag field of the outbound packet
3147 * with the value found in the Verification Tag field of the OOTB
3148 * packet and set the T-bit in the Chunk Flags to indicate that the
3149 * Verification Tag is reflected. After sending this ABORT, the
3150 * receiver of the OOTB packet shall discard the OOTB packet and take
3151 * no further action.
3152 *
3153 * Verification Tag:
3154 *
3155 * The return value is the disposition of the chunk.
3156*/
3157static sctp_disposition_t sctp_sf_tabort_8_4_8(const struct sctp_endpoint *ep,
3158 const struct sctp_association *asoc,
3159 const sctp_subtype_t type,
3160 void *arg,
3161 sctp_cmd_seq_t *commands)
3162{
3163 struct sctp_packet *packet = NULL;
3164 struct sctp_chunk *chunk = arg;
3165 struct sctp_chunk *abort;
3166
3167 packet = sctp_ootb_pkt_new(asoc, chunk);
3168
3169 if (packet) {
3170 /* Make an ABORT. The T bit will be set if the asoc
3171 * is NULL.
3172 */
3173 abort = sctp_make_abort(asoc, chunk, 0);
3174 if (!abort) {
3175 sctp_ootb_pkt_free(packet);
3176 return SCTP_DISPOSITION_NOMEM;
3177 }
3178
3179 /* Reflect vtag if T-Bit is set */
3180 if (sctp_test_T_bit(abort))
3181 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3182
3183 /* Set the skb to the belonging sock for accounting. */
3184 abort->skb->sk = ep->base.sk;
3185
3186 sctp_packet_append_chunk(packet, abort);
3187
3188 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3189 SCTP_PACKET(packet));
3190
3191 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
3192
3193 sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3194 return SCTP_DISPOSITION_CONSUME;
3195 }
3196
3197 return SCTP_DISPOSITION_NOMEM;
3198}
3199
3200/*
3201 * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR
3202 * event as ULP notification for each cause included in the chunk.
3203 *
3204 * API 5.3.1.3 - SCTP_REMOTE_ERROR
3205 *
3206 * The return value is the disposition of the chunk.
3207*/
3208sctp_disposition_t sctp_sf_operr_notify(const struct sctp_endpoint *ep,
3209 const struct sctp_association *asoc,
3210 const sctp_subtype_t type,
3211 void *arg,
3212 sctp_cmd_seq_t *commands)
3213{
3214 struct sctp_chunk *chunk = arg;
3215 sctp_errhdr_t *err;
3216
3217 if (!sctp_vtag_verify(chunk, asoc))
3218 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3219
3220 /* Make sure that the ERROR chunk has a valid length. */
3221 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
3222 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3223 commands);
3224 sctp_walk_errors(err, chunk->chunk_hdr);
3225 if ((void *)err != (void *)chunk->chunk_end)
3226 return sctp_sf_violation_paramlen(ep, asoc, type, arg,
3227 (void *)err, commands);
3228
3229 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_OPERR,
3230 SCTP_CHUNK(chunk));
3231
3232 return SCTP_DISPOSITION_CONSUME;
3233}
3234
3235/*
3236 * Process an inbound SHUTDOWN ACK.
3237 *
3238 * From Section 9.2:
3239 * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3240 * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its
3241 * peer, and remove all record of the association.
3242 *
3243 * The return value is the disposition.
3244 */
3245sctp_disposition_t sctp_sf_do_9_2_final(const struct sctp_endpoint *ep,
3246 const struct sctp_association *asoc,
3247 const sctp_subtype_t type,
3248 void *arg,
3249 sctp_cmd_seq_t *commands)
3250{
3251 struct sctp_chunk *chunk = arg;
3252 struct sctp_chunk *reply;
3253 struct sctp_ulpevent *ev;
3254
3255 if (!sctp_vtag_verify(chunk, asoc))
3256 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3257
3258 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3259 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3260 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3261 commands);
3262 /* 10.2 H) SHUTDOWN COMPLETE notification
3263 *
3264 * When SCTP completes the shutdown procedures (section 9.2) this
3265 * notification is passed to the upper layer.
3266 */
3267 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
3268 0, 0, 0, NULL, GFP_ATOMIC);
3269 if (!ev)
3270 goto nomem;
3271
3272 /* ...send a SHUTDOWN COMPLETE chunk to its peer, */
3273 reply = sctp_make_shutdown_complete(asoc, chunk);
3274 if (!reply)
3275 goto nomem_chunk;
3276
3277 /* Do all the commands now (after allocation), so that we
3278 * have consistent state if memory allocation failes
3279 */
3280 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
3281
3282 /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3283 * stop the T2-shutdown timer,
3284 */
3285 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3286 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3287
3288 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3289 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
3290
3291 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3292 SCTP_STATE(SCTP_STATE_CLOSED));
3293 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
3294 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3295 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
3296
3297 /* ...and remove all record of the association. */
3298 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
3299 return SCTP_DISPOSITION_DELETE_TCB;
3300
3301nomem_chunk:
3302 sctp_ulpevent_free(ev);
3303nomem:
3304 return SCTP_DISPOSITION_NOMEM;
3305}
3306
3307/*
3308 * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41.
3309 *
3310 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3311 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3312 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3313 * packet must fill in the Verification Tag field of the outbound
3314 * packet with the Verification Tag received in the SHUTDOWN ACK and
3315 * set the T-bit in the Chunk Flags to indicate that the Verification
3316 * Tag is reflected.
3317 *
3318 * 8) The receiver should respond to the sender of the OOTB packet with
3319 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3320 * MUST fill in the Verification Tag field of the outbound packet
3321 * with the value found in the Verification Tag field of the OOTB
3322 * packet and set the T-bit in the Chunk Flags to indicate that the
3323 * Verification Tag is reflected. After sending this ABORT, the
3324 * receiver of the OOTB packet shall discard the OOTB packet and take
3325 * no further action.
3326 */
3327sctp_disposition_t sctp_sf_ootb(const struct sctp_endpoint *ep,
3328 const struct sctp_association *asoc,
3329 const sctp_subtype_t type,
3330 void *arg,
3331 sctp_cmd_seq_t *commands)
3332{
3333 struct sctp_chunk *chunk = arg;
3334 struct sk_buff *skb = chunk->skb;
3335 sctp_chunkhdr_t *ch;
3336 sctp_errhdr_t *err;
3337 __u8 *ch_end;
3338 int ootb_shut_ack = 0;
3339 int ootb_cookie_ack = 0;
3340
3341 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES);
3342
3343 ch = (sctp_chunkhdr_t *) chunk->chunk_hdr;
3344 do {
3345 /* Report violation if the chunk is less then minimal */
3346 if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t))
3347 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3348 commands);
3349
3350 /* Now that we know we at least have a chunk header,
3351 * do things that are type appropriate.
3352 */
3353 if (SCTP_CID_SHUTDOWN_ACK == ch->type)
3354 ootb_shut_ack = 1;
3355
3356 /* RFC 2960, Section 3.3.7
3357 * Moreover, under any circumstances, an endpoint that
3358 * receives an ABORT MUST NOT respond to that ABORT by
3359 * sending an ABORT of its own.
3360 */
3361 if (SCTP_CID_ABORT == ch->type)
3362 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3363
3364 /* RFC 8.4, 7) If the packet contains a "Stale cookie" ERROR
3365 * or a COOKIE ACK the SCTP Packet should be silently
3366 * discarded.
3367 */
3368
3369 if (SCTP_CID_COOKIE_ACK == ch->type)
3370 ootb_cookie_ack = 1;
3371
3372 if (SCTP_CID_ERROR == ch->type) {
3373 sctp_walk_errors(err, ch) {
3374 if (SCTP_ERROR_STALE_COOKIE == err->cause) {
3375 ootb_cookie_ack = 1;
3376 break;
3377 }
3378 }
3379 }
3380
3381 /* Report violation if chunk len overflows */
3382 ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
3383 if (ch_end > skb_tail_pointer(skb))
3384 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3385 commands);
3386
3387 ch = (sctp_chunkhdr_t *) ch_end;
3388 } while (ch_end < skb_tail_pointer(skb));
3389
3390 if (ootb_shut_ack)
3391 return sctp_sf_shut_8_4_5(ep, asoc, type, arg, commands);
3392 else if (ootb_cookie_ack)
3393 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3394 else
3395 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
3396}
3397
3398/*
3399 * Handle an "Out of the blue" SHUTDOWN ACK.
3400 *
3401 * Section: 8.4 5, sctpimpguide 2.41.
3402 *
3403 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3404 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3405 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3406 * packet must fill in the Verification Tag field of the outbound
3407 * packet with the Verification Tag received in the SHUTDOWN ACK and
3408 * set the T-bit in the Chunk Flags to indicate that the Verification
3409 * Tag is reflected.
3410 *
3411 * Inputs
3412 * (endpoint, asoc, type, arg, commands)
3413 *
3414 * Outputs
3415 * (sctp_disposition_t)
3416 *
3417 * The return value is the disposition of the chunk.
3418 */
3419static sctp_disposition_t sctp_sf_shut_8_4_5(const struct sctp_endpoint *ep,
3420 const struct sctp_association *asoc,
3421 const sctp_subtype_t type,
3422 void *arg,
3423 sctp_cmd_seq_t *commands)
3424{
3425 struct sctp_packet *packet = NULL;
3426 struct sctp_chunk *chunk = arg;
3427 struct sctp_chunk *shut;
3428
3429 packet = sctp_ootb_pkt_new(asoc, chunk);
3430
3431 if (packet) {
3432 /* Make an SHUTDOWN_COMPLETE.
3433 * The T bit will be set if the asoc is NULL.
3434 */
3435 shut = sctp_make_shutdown_complete(asoc, chunk);
3436 if (!shut) {
3437 sctp_ootb_pkt_free(packet);
3438 return SCTP_DISPOSITION_NOMEM;
3439 }
3440
3441 /* Reflect vtag if T-Bit is set */
3442 if (sctp_test_T_bit(shut))
3443 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3444
3445 /* Set the skb to the belonging sock for accounting. */
3446 shut->skb->sk = ep->base.sk;
3447
3448 sctp_packet_append_chunk(packet, shut);
3449
3450 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3451 SCTP_PACKET(packet));
3452
3453 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
3454
3455 /* If the chunk length is invalid, we don't want to process
3456 * the reset of the packet.
3457 */
3458 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3459 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3460
3461 /* We need to discard the rest of the packet to prevent
3462 * potential bomming attacks from additional bundled chunks.
3463 * This is documented in SCTP Threats ID.
3464 */
3465 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3466 }
3467
3468 return SCTP_DISPOSITION_NOMEM;
3469}
3470
3471/*
3472 * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state.
3473 *
3474 * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK
3475 * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the
3476 * procedures in section 8.4 SHOULD be followed, in other words it
3477 * should be treated as an Out Of The Blue packet.
3478 * [This means that we do NOT check the Verification Tag on these
3479 * chunks. --piggy ]
3480 *
3481 */
3482sctp_disposition_t sctp_sf_do_8_5_1_E_sa(const struct sctp_endpoint *ep,
3483 const struct sctp_association *asoc,
3484 const sctp_subtype_t type,
3485 void *arg,
3486 sctp_cmd_seq_t *commands)
3487{
3488 struct sctp_chunk *chunk = arg;
3489
3490 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3491 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3492 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3493 commands);
3494
3495 /* Although we do have an association in this case, it corresponds
3496 * to a restarted association. So the packet is treated as an OOTB
3497 * packet and the state function that handles OOTB SHUTDOWN_ACK is
3498 * called with a NULL association.
3499 */
3500 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES);
3501
3502 return sctp_sf_shut_8_4_5(ep, NULL, type, arg, commands);
3503}
3504
3505/* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */
3506sctp_disposition_t sctp_sf_do_asconf(const struct sctp_endpoint *ep,
3507 const struct sctp_association *asoc,
3508 const sctp_subtype_t type, void *arg,
3509 sctp_cmd_seq_t *commands)
3510{
3511 struct sctp_chunk *chunk = arg;
3512 struct sctp_chunk *asconf_ack = NULL;
3513 struct sctp_paramhdr *err_param = NULL;
3514 sctp_addiphdr_t *hdr;
3515 union sctp_addr_param *addr_param;
3516 __u32 serial;
3517 int length;
3518
3519 if (!sctp_vtag_verify(chunk, asoc)) {
3520 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3521 SCTP_NULL());
3522 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3523 }
3524
3525 /* ADD-IP: Section 4.1.1
3526 * This chunk MUST be sent in an authenticated way by using
3527 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3528 * is received unauthenticated it MUST be silently discarded as
3529 * described in [I-D.ietf-tsvwg-sctp-auth].
3530 */
3531 if (!sctp_addip_noauth && !chunk->auth)
3532 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
3533
3534 /* Make sure that the ASCONF ADDIP chunk has a valid length. */
3535 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_addip_chunk_t)))
3536 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3537 commands);
3538
3539 hdr = (sctp_addiphdr_t *)chunk->skb->data;
3540 serial = ntohl(hdr->serial);
3541
3542 addr_param = (union sctp_addr_param *)hdr->params;
3543 length = ntohs(addr_param->p.length);
3544 if (length < sizeof(sctp_paramhdr_t))
3545 return sctp_sf_violation_paramlen(ep, asoc, type, arg,
3546 (void *)addr_param, commands);
3547
3548 /* Verify the ASCONF chunk before processing it. */
3549 if (!sctp_verify_asconf(asoc,
3550 (sctp_paramhdr_t *)((void *)addr_param + length),
3551 (void *)chunk->chunk_end,
3552 &err_param))
3553 return sctp_sf_violation_paramlen(ep, asoc, type, arg,
3554 (void *)err_param, commands);
3555
3556 /* ADDIP 5.2 E1) Compare the value of the serial number to the value
3557 * the endpoint stored in a new association variable
3558 * 'Peer-Serial-Number'.
3559 */
3560 if (serial == asoc->peer.addip_serial + 1) {
3561 /* If this is the first instance of ASCONF in the packet,
3562 * we can clean our old ASCONF-ACKs.
3563 */
3564 if (!chunk->has_asconf)
3565 sctp_assoc_clean_asconf_ack_cache(asoc);
3566
3567 /* ADDIP 5.2 E4) When the Sequence Number matches the next one
3568 * expected, process the ASCONF as described below and after
3569 * processing the ASCONF Chunk, append an ASCONF-ACK Chunk to
3570 * the response packet and cache a copy of it (in the event it
3571 * later needs to be retransmitted).
3572 *
3573 * Essentially, do V1-V5.
3574 */
3575 asconf_ack = sctp_process_asconf((struct sctp_association *)
3576 asoc, chunk);
3577 if (!asconf_ack)
3578 return SCTP_DISPOSITION_NOMEM;
3579 } else if (serial < asoc->peer.addip_serial + 1) {
3580 /* ADDIP 5.2 E2)
3581 * If the value found in the Sequence Number is less than the
3582 * ('Peer- Sequence-Number' + 1), simply skip to the next
3583 * ASCONF, and include in the outbound response packet
3584 * any previously cached ASCONF-ACK response that was
3585 * sent and saved that matches the Sequence Number of the
3586 * ASCONF. Note: It is possible that no cached ASCONF-ACK
3587 * Chunk exists. This will occur when an older ASCONF
3588 * arrives out of order. In such a case, the receiver
3589 * should skip the ASCONF Chunk and not include ASCONF-ACK
3590 * Chunk for that chunk.
3591 */
3592 asconf_ack = sctp_assoc_lookup_asconf_ack(asoc, hdr->serial);
3593 if (!asconf_ack)
3594 return SCTP_DISPOSITION_DISCARD;
3595
3596 /* Reset the transport so that we select the correct one
3597 * this time around. This is to make sure that we don't
3598 * accidentally use a stale transport that's been removed.
3599 */
3600 asconf_ack->transport = NULL;
3601 } else {
3602 /* ADDIP 5.2 E5) Otherwise, the ASCONF Chunk is discarded since
3603 * it must be either a stale packet or from an attacker.
3604 */
3605 return SCTP_DISPOSITION_DISCARD;
3606 }
3607
3608 /* ADDIP 5.2 E6) The destination address of the SCTP packet
3609 * containing the ASCONF-ACK Chunks MUST be the source address of
3610 * the SCTP packet that held the ASCONF Chunks.
3611 *
3612 * To do this properly, we'll set the destination address of the chunk
3613 * and at the transmit time, will try look up the transport to use.
3614 * Since ASCONFs may be bundled, the correct transport may not be
3615 * created until we process the entire packet, thus this workaround.
3616 */
3617 asconf_ack->dest = chunk->source;
3618 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(asconf_ack));
3619 if (asoc->new_transport) {
3620 sctp_sf_heartbeat(ep, asoc, type, asoc->new_transport,
3621 commands);
3622 ((struct sctp_association *)asoc)->new_transport = NULL;
3623 }
3624
3625 return SCTP_DISPOSITION_CONSUME;
3626}
3627
3628/*
3629 * ADDIP Section 4.3 General rules for address manipulation
3630 * When building TLV parameters for the ASCONF Chunk that will add or
3631 * delete IP addresses the D0 to D13 rules should be applied:
3632 */
3633sctp_disposition_t sctp_sf_do_asconf_ack(const struct sctp_endpoint *ep,
3634 const struct sctp_association *asoc,
3635 const sctp_subtype_t type, void *arg,
3636 sctp_cmd_seq_t *commands)
3637{
3638 struct sctp_chunk *asconf_ack = arg;
3639 struct sctp_chunk *last_asconf = asoc->addip_last_asconf;
3640 struct sctp_chunk *abort;
3641 struct sctp_paramhdr *err_param = NULL;
3642 sctp_addiphdr_t *addip_hdr;
3643 __u32 sent_serial, rcvd_serial;
3644
3645 if (!sctp_vtag_verify(asconf_ack, asoc)) {
3646 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3647 SCTP_NULL());
3648 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3649 }
3650
3651 /* ADD-IP, Section 4.1.2:
3652 * This chunk MUST be sent in an authenticated way by using
3653 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3654 * is received unauthenticated it MUST be silently discarded as
3655 * described in [I-D.ietf-tsvwg-sctp-auth].
3656 */
3657 if (!sctp_addip_noauth && !asconf_ack->auth)
3658 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
3659
3660 /* Make sure that the ADDIP chunk has a valid length. */
3661 if (!sctp_chunk_length_valid(asconf_ack, sizeof(sctp_addip_chunk_t)))
3662 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3663 commands);
3664
3665 addip_hdr = (sctp_addiphdr_t *)asconf_ack->skb->data;
3666 rcvd_serial = ntohl(addip_hdr->serial);
3667
3668 /* Verify the ASCONF-ACK chunk before processing it. */
3669 if (!sctp_verify_asconf(asoc,
3670 (sctp_paramhdr_t *)addip_hdr->params,
3671 (void *)asconf_ack->chunk_end,
3672 &err_param))
3673 return sctp_sf_violation_paramlen(ep, asoc, type, arg,
3674 (void *)err_param, commands);
3675
3676 if (last_asconf) {
3677 addip_hdr = (sctp_addiphdr_t *)last_asconf->subh.addip_hdr;
3678 sent_serial = ntohl(addip_hdr->serial);
3679 } else {
3680 sent_serial = asoc->addip_serial - 1;
3681 }
3682
3683 /* D0) If an endpoint receives an ASCONF-ACK that is greater than or
3684 * equal to the next serial number to be used but no ASCONF chunk is
3685 * outstanding the endpoint MUST ABORT the association. Note that a
3686 * sequence number is greater than if it is no more than 2^^31-1
3687 * larger than the current sequence number (using serial arithmetic).
3688 */
3689 if (ADDIP_SERIAL_gte(rcvd_serial, sent_serial + 1) &&
3690 !(asoc->addip_last_asconf)) {
3691 abort = sctp_make_abort(asoc, asconf_ack,
3692 sizeof(sctp_errhdr_t));
3693 if (abort) {
3694 sctp_init_cause(abort, SCTP_ERROR_ASCONF_ACK, 0);
3695 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3696 SCTP_CHUNK(abort));
3697 }
3698 /* We are going to ABORT, so we might as well stop
3699 * processing the rest of the chunks in the packet.
3700 */
3701 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3702 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3703 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
3704 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
3705 SCTP_ERROR(ECONNABORTED));
3706 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
3707 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
3708 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
3709 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3710 return SCTP_DISPOSITION_ABORT;
3711 }
3712
3713 if ((rcvd_serial == sent_serial) && asoc->addip_last_asconf) {
3714 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3715 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3716
3717 if (!sctp_process_asconf_ack((struct sctp_association *)asoc,
3718 asconf_ack)) {
3719 /* Successfully processed ASCONF_ACK. We can
3720 * release the next asconf if we have one.
3721 */
3722 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_NEXT_ASCONF,
3723 SCTP_NULL());
3724 return SCTP_DISPOSITION_CONSUME;
3725 }
3726
3727 abort = sctp_make_abort(asoc, asconf_ack,
3728 sizeof(sctp_errhdr_t));
3729 if (abort) {
3730 sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0);
3731 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3732 SCTP_CHUNK(abort));
3733 }
3734 /* We are going to ABORT, so we might as well stop
3735 * processing the rest of the chunks in the packet.
3736 */
3737 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
3738 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
3739 SCTP_ERROR(ECONNABORTED));
3740 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
3741 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
3742 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
3743 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3744 return SCTP_DISPOSITION_ABORT;
3745 }
3746
3747 return SCTP_DISPOSITION_DISCARD;
3748}
3749
3750/*
3751 * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP
3752 *
3753 * When a FORWARD TSN chunk arrives, the data receiver MUST first update
3754 * its cumulative TSN point to the value carried in the FORWARD TSN
3755 * chunk, and then MUST further advance its cumulative TSN point locally
3756 * if possible.
3757 * After the above processing, the data receiver MUST stop reporting any
3758 * missing TSNs earlier than or equal to the new cumulative TSN point.
3759 *
3760 * Verification Tag: 8.5 Verification Tag [Normal verification]
3761 *
3762 * The return value is the disposition of the chunk.
3763 */
3764sctp_disposition_t sctp_sf_eat_fwd_tsn(const struct sctp_endpoint *ep,
3765 const struct sctp_association *asoc,
3766 const sctp_subtype_t type,
3767 void *arg,
3768 sctp_cmd_seq_t *commands)
3769{
3770 struct sctp_chunk *chunk = arg;
3771 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
3772 struct sctp_fwdtsn_skip *skip;
3773 __u16 len;
3774 __u32 tsn;
3775
3776 if (!sctp_vtag_verify(chunk, asoc)) {
3777 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3778 SCTP_NULL());
3779 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3780 }
3781
3782 /* Make sure that the FORWARD_TSN chunk has valid length. */
3783 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
3784 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3785 commands);
3786
3787 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3788 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3789 len = ntohs(chunk->chunk_hdr->length);
3790 len -= sizeof(struct sctp_chunkhdr);
3791 skb_pull(chunk->skb, len);
3792
3793 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
3794 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __func__, tsn);
3795
3796 /* The TSN is too high--silently discard the chunk and count on it
3797 * getting retransmitted later.
3798 */
3799 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3800 goto discard_noforce;
3801
3802 /* Silently discard the chunk if stream-id is not valid */
3803 sctp_walk_fwdtsn(skip, chunk) {
3804 if (ntohs(skip->stream) >= asoc->c.sinit_max_instreams)
3805 goto discard_noforce;
3806 }
3807
3808 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3809 if (len > sizeof(struct sctp_fwdtsn_hdr))
3810 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
3811 SCTP_CHUNK(chunk));
3812
3813 /* Count this as receiving DATA. */
3814 if (asoc->autoclose) {
3815 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3816 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
3817 }
3818
3819 /* FIXME: For now send a SACK, but DATA processing may
3820 * send another.
3821 */
3822 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
3823
3824 return SCTP_DISPOSITION_CONSUME;
3825
3826discard_noforce:
3827 return SCTP_DISPOSITION_DISCARD;
3828}
3829
3830sctp_disposition_t sctp_sf_eat_fwd_tsn_fast(
3831 const struct sctp_endpoint *ep,
3832 const struct sctp_association *asoc,
3833 const sctp_subtype_t type,
3834 void *arg,
3835 sctp_cmd_seq_t *commands)
3836{
3837 struct sctp_chunk *chunk = arg;
3838 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
3839 struct sctp_fwdtsn_skip *skip;
3840 __u16 len;
3841 __u32 tsn;
3842
3843 if (!sctp_vtag_verify(chunk, asoc)) {
3844 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3845 SCTP_NULL());
3846 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3847 }
3848
3849 /* Make sure that the FORWARD_TSN chunk has a valid length. */
3850 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
3851 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3852 commands);
3853
3854 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3855 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3856 len = ntohs(chunk->chunk_hdr->length);
3857 len -= sizeof(struct sctp_chunkhdr);
3858 skb_pull(chunk->skb, len);
3859
3860 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
3861 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __func__, tsn);
3862
3863 /* The TSN is too high--silently discard the chunk and count on it
3864 * getting retransmitted later.
3865 */
3866 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3867 goto gen_shutdown;
3868
3869 /* Silently discard the chunk if stream-id is not valid */
3870 sctp_walk_fwdtsn(skip, chunk) {
3871 if (ntohs(skip->stream) >= asoc->c.sinit_max_instreams)
3872 goto gen_shutdown;
3873 }
3874
3875 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3876 if (len > sizeof(struct sctp_fwdtsn_hdr))
3877 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
3878 SCTP_CHUNK(chunk));
3879
3880 /* Go a head and force a SACK, since we are shutting down. */
3881gen_shutdown:
3882 /* Implementor's Guide.
3883 *
3884 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3885 * respond to each received packet containing one or more DATA chunk(s)
3886 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3887 */
3888 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
3889 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3890 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3891 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3892
3893 return SCTP_DISPOSITION_CONSUME;
3894}
3895
3896/*
3897 * SCTP-AUTH Section 6.3 Receiving authenticated chukns
3898 *
3899 * The receiver MUST use the HMAC algorithm indicated in the HMAC
3900 * Identifier field. If this algorithm was not specified by the
3901 * receiver in the HMAC-ALGO parameter in the INIT or INIT-ACK chunk
3902 * during association setup, the AUTH chunk and all chunks after it MUST
3903 * be discarded and an ERROR chunk SHOULD be sent with the error cause
3904 * defined in Section 4.1.
3905 *
3906 * If an endpoint with no shared key receives a Shared Key Identifier
3907 * other than 0, it MUST silently discard all authenticated chunks. If
3908 * the endpoint has at least one endpoint pair shared key for the peer,
3909 * it MUST use the key specified by the Shared Key Identifier if a
3910 * key has been configured for that Shared Key Identifier. If no
3911 * endpoint pair shared key has been configured for that Shared Key
3912 * Identifier, all authenticated chunks MUST be silently discarded.
3913 *
3914 * Verification Tag: 8.5 Verification Tag [Normal verification]
3915 *
3916 * The return value is the disposition of the chunk.
3917 */
3918static sctp_ierror_t sctp_sf_authenticate(const struct sctp_endpoint *ep,
3919 const struct sctp_association *asoc,
3920 const sctp_subtype_t type,
3921 struct sctp_chunk *chunk)
3922{
3923 struct sctp_authhdr *auth_hdr;
3924 struct sctp_hmac *hmac;
3925 unsigned int sig_len;
3926 __u16 key_id;
3927 __u8 *save_digest;
3928 __u8 *digest;
3929
3930 /* Pull in the auth header, so we can do some more verification */
3931 auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
3932 chunk->subh.auth_hdr = auth_hdr;
3933 skb_pull(chunk->skb, sizeof(struct sctp_authhdr));
3934
3935 /* Make sure that we suport the HMAC algorithm from the auth
3936 * chunk.
3937 */
3938 if (!sctp_auth_asoc_verify_hmac_id(asoc, auth_hdr->hmac_id))
3939 return SCTP_IERROR_AUTH_BAD_HMAC;
3940
3941 /* Make sure that the provided shared key identifier has been
3942 * configured
3943 */
3944 key_id = ntohs(auth_hdr->shkey_id);
3945 if (key_id != asoc->active_key_id && !sctp_auth_get_shkey(asoc, key_id))
3946 return SCTP_IERROR_AUTH_BAD_KEYID;
3947
3948
3949 /* Make sure that the length of the signature matches what
3950 * we expect.
3951 */
3952 sig_len = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_auth_chunk_t);
3953 hmac = sctp_auth_get_hmac(ntohs(auth_hdr->hmac_id));
3954 if (sig_len != hmac->hmac_len)
3955 return SCTP_IERROR_PROTO_VIOLATION;
3956
3957 /* Now that we've done validation checks, we can compute and
3958 * verify the hmac. The steps involved are:
3959 * 1. Save the digest from the chunk.
3960 * 2. Zero out the digest in the chunk.
3961 * 3. Compute the new digest
3962 * 4. Compare saved and new digests.
3963 */
3964 digest = auth_hdr->hmac;
3965 skb_pull(chunk->skb, sig_len);
3966
3967 save_digest = kmemdup(digest, sig_len, GFP_ATOMIC);
3968 if (!save_digest)
3969 goto nomem;
3970
3971 memset(digest, 0, sig_len);
3972
3973 sctp_auth_calculate_hmac(asoc, chunk->skb,
3974 (struct sctp_auth_chunk *)chunk->chunk_hdr,
3975 GFP_ATOMIC);
3976
3977 /* Discard the packet if the digests do not match */
3978 if (memcmp(save_digest, digest, sig_len)) {
3979 kfree(save_digest);
3980 return SCTP_IERROR_BAD_SIG;
3981 }
3982
3983 kfree(save_digest);
3984 chunk->auth = 1;
3985
3986 return SCTP_IERROR_NO_ERROR;
3987nomem:
3988 return SCTP_IERROR_NOMEM;
3989}
3990
3991sctp_disposition_t sctp_sf_eat_auth(const struct sctp_endpoint *ep,
3992 const struct sctp_association *asoc,
3993 const sctp_subtype_t type,
3994 void *arg,
3995 sctp_cmd_seq_t *commands)
3996{
3997 struct sctp_authhdr *auth_hdr;
3998 struct sctp_chunk *chunk = arg;
3999 struct sctp_chunk *err_chunk;
4000 sctp_ierror_t error;
4001
4002 /* Make sure that the peer has AUTH capable */
4003 if (!asoc->peer.auth_capable)
4004 return sctp_sf_unk_chunk(ep, asoc, type, arg, commands);
4005
4006 if (!sctp_vtag_verify(chunk, asoc)) {
4007 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
4008 SCTP_NULL());
4009 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
4010 }
4011
4012 /* Make sure that the AUTH chunk has valid length. */
4013 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_auth_chunk)))
4014 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
4015 commands);
4016
4017 auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
4018 error = sctp_sf_authenticate(ep, asoc, type, chunk);
4019 switch (error) {
4020 case SCTP_IERROR_AUTH_BAD_HMAC:
4021 /* Generate the ERROR chunk and discard the rest
4022 * of the packet
4023 */
4024 err_chunk = sctp_make_op_error(asoc, chunk,
4025 SCTP_ERROR_UNSUP_HMAC,
4026 &auth_hdr->hmac_id,
4027 sizeof(__u16), 0);
4028 if (err_chunk) {
4029 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4030 SCTP_CHUNK(err_chunk));
4031 }
4032 /* Fall Through */
4033 case SCTP_IERROR_AUTH_BAD_KEYID:
4034 case SCTP_IERROR_BAD_SIG:
4035 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
4036
4037 case SCTP_IERROR_PROTO_VIOLATION:
4038 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
4039 commands);
4040
4041 case SCTP_IERROR_NOMEM:
4042 return SCTP_DISPOSITION_NOMEM;
4043
4044 default: /* Prevent gcc warnings */
4045 break;
4046 }
4047
4048 if (asoc->active_key_id != ntohs(auth_hdr->shkey_id)) {
4049 struct sctp_ulpevent *ev;
4050
4051 ev = sctp_ulpevent_make_authkey(asoc, ntohs(auth_hdr->shkey_id),
4052 SCTP_AUTH_NEWKEY, GFP_ATOMIC);
4053
4054 if (!ev)
4055 return -ENOMEM;
4056
4057 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
4058 SCTP_ULPEVENT(ev));
4059 }
4060
4061 return SCTP_DISPOSITION_CONSUME;
4062}
4063
4064/*
4065 * Process an unknown chunk.
4066 *
4067 * Section: 3.2. Also, 2.1 in the implementor's guide.
4068 *
4069 * Chunk Types are encoded such that the highest-order two bits specify
4070 * the action that must be taken if the processing endpoint does not
4071 * recognize the Chunk Type.
4072 *
4073 * 00 - Stop processing this SCTP packet and discard it, do not process
4074 * any further chunks within it.
4075 *
4076 * 01 - Stop processing this SCTP packet and discard it, do not process
4077 * any further chunks within it, and report the unrecognized
4078 * chunk in an 'Unrecognized Chunk Type'.
4079 *
4080 * 10 - Skip this chunk and continue processing.
4081 *
4082 * 11 - Skip this chunk and continue processing, but report in an ERROR
4083 * Chunk using the 'Unrecognized Chunk Type' cause of error.
4084 *
4085 * The return value is the disposition of the chunk.
4086 */
4087sctp_disposition_t sctp_sf_unk_chunk(const struct sctp_endpoint *ep,
4088 const struct sctp_association *asoc,
4089 const sctp_subtype_t type,
4090 void *arg,
4091 sctp_cmd_seq_t *commands)
4092{
4093 struct sctp_chunk *unk_chunk = arg;
4094 struct sctp_chunk *err_chunk;
4095 sctp_chunkhdr_t *hdr;
4096
4097 SCTP_DEBUG_PRINTK("Processing the unknown chunk id %d.\n", type.chunk);
4098
4099 if (!sctp_vtag_verify(unk_chunk, asoc))
4100 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
4101
4102 /* Make sure that the chunk has a valid length.
4103 * Since we don't know the chunk type, we use a general
4104 * chunkhdr structure to make a comparison.
4105 */
4106 if (!sctp_chunk_length_valid(unk_chunk, sizeof(sctp_chunkhdr_t)))
4107 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
4108 commands);
4109
4110 switch (type.chunk & SCTP_CID_ACTION_MASK) {
4111 case SCTP_CID_ACTION_DISCARD:
4112 /* Discard the packet. */
4113 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
4114 break;
4115 case SCTP_CID_ACTION_DISCARD_ERR:
4116 /* Generate an ERROR chunk as response. */
4117 hdr = unk_chunk->chunk_hdr;
4118 err_chunk = sctp_make_op_error(asoc, unk_chunk,
4119 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
4120 WORD_ROUND(ntohs(hdr->length)),
4121 0);
4122 if (err_chunk) {
4123 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4124 SCTP_CHUNK(err_chunk));
4125 }
4126
4127 /* Discard the packet. */
4128 sctp_sf_pdiscard(ep, asoc, type, arg, commands);
4129 return SCTP_DISPOSITION_CONSUME;
4130 break;
4131 case SCTP_CID_ACTION_SKIP:
4132 /* Skip the chunk. */
4133 return SCTP_DISPOSITION_DISCARD;
4134 break;
4135 case SCTP_CID_ACTION_SKIP_ERR:
4136 /* Generate an ERROR chunk as response. */
4137 hdr = unk_chunk->chunk_hdr;
4138 err_chunk = sctp_make_op_error(asoc, unk_chunk,
4139 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
4140 WORD_ROUND(ntohs(hdr->length)),
4141 0);
4142 if (err_chunk) {
4143 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4144 SCTP_CHUNK(err_chunk));
4145 }
4146 /* Skip the chunk. */
4147 return SCTP_DISPOSITION_CONSUME;
4148 break;
4149 default:
4150 break;
4151 }
4152
4153 return SCTP_DISPOSITION_DISCARD;
4154}
4155
4156/*
4157 * Discard the chunk.
4158 *
4159 * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2
4160 * [Too numerous to mention...]
4161 * Verification Tag: No verification needed.
4162 * Inputs
4163 * (endpoint, asoc, chunk)
4164 *
4165 * Outputs
4166 * (asoc, reply_msg, msg_up, timers, counters)
4167 *
4168 * The return value is the disposition of the chunk.
4169 */
4170sctp_disposition_t sctp_sf_discard_chunk(const struct sctp_endpoint *ep,
4171 const struct sctp_association *asoc,
4172 const sctp_subtype_t type,
4173 void *arg,
4174 sctp_cmd_seq_t *commands)
4175{
4176 struct sctp_chunk *chunk = arg;
4177
4178 /* Make sure that the chunk has a valid length.
4179 * Since we don't know the chunk type, we use a general
4180 * chunkhdr structure to make a comparison.
4181 */
4182 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
4183 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
4184 commands);
4185
4186 SCTP_DEBUG_PRINTK("Chunk %d is discarded\n", type.chunk);
4187 return SCTP_DISPOSITION_DISCARD;
4188}
4189
4190/*
4191 * Discard the whole packet.
4192 *
4193 * Section: 8.4 2)
4194 *
4195 * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST
4196 * silently discard the OOTB packet and take no further action.
4197 *
4198 * Verification Tag: No verification necessary
4199 *
4200 * Inputs
4201 * (endpoint, asoc, chunk)
4202 *
4203 * Outputs
4204 * (asoc, reply_msg, msg_up, timers, counters)
4205 *
4206 * The return value is the disposition of the chunk.
4207 */
4208sctp_disposition_t sctp_sf_pdiscard(const struct sctp_endpoint *ep,
4209 const struct sctp_association *asoc,
4210 const sctp_subtype_t type,
4211 void *arg,
4212 sctp_cmd_seq_t *commands)
4213{
4214 SCTP_INC_STATS(SCTP_MIB_IN_PKT_DISCARDS);
4215 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
4216
4217 return SCTP_DISPOSITION_CONSUME;
4218}
4219
4220
4221/*
4222 * The other end is violating protocol.
4223 *
4224 * Section: Not specified
4225 * Verification Tag: Not specified
4226 * Inputs
4227 * (endpoint, asoc, chunk)
4228 *
4229 * Outputs
4230 * (asoc, reply_msg, msg_up, timers, counters)
4231 *
4232 * We simply tag the chunk as a violation. The state machine will log
4233 * the violation and continue.
4234 */
4235sctp_disposition_t sctp_sf_violation(const struct sctp_endpoint *ep,
4236 const struct sctp_association *asoc,
4237 const sctp_subtype_t type,
4238 void *arg,
4239 sctp_cmd_seq_t *commands)
4240{
4241 struct sctp_chunk *chunk = arg;
4242
4243 /* Make sure that the chunk has a valid length. */
4244 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
4245 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
4246 commands);
4247
4248 return SCTP_DISPOSITION_VIOLATION;
4249}
4250
4251/*
4252 * Common function to handle a protocol violation.
4253 */
4254static sctp_disposition_t sctp_sf_abort_violation(
4255 const struct sctp_endpoint *ep,
4256 const struct sctp_association *asoc,
4257 void *arg,
4258 sctp_cmd_seq_t *commands,
4259 const __u8 *payload,
4260 const size_t paylen)
4261{
4262 struct sctp_packet *packet = NULL;
4263 struct sctp_chunk *chunk = arg;
4264 struct sctp_chunk *abort = NULL;
4265
4266 /* SCTP-AUTH, Section 6.3:
4267 * It should be noted that if the receiver wants to tear
4268 * down an association in an authenticated way only, the
4269 * handling of malformed packets should not result in
4270 * tearing down the association.
4271 *
4272 * This means that if we only want to abort associations
4273 * in an authenticated way (i.e AUTH+ABORT), then we
4274 * can't destroy this association just because the packet
4275 * was malformed.
4276 */
4277 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
4278 goto discard;
4279
4280 /* Make the abort chunk. */
4281 abort = sctp_make_abort_violation(asoc, chunk, payload, paylen);
4282 if (!abort)
4283 goto nomem;
4284
4285 if (asoc) {
4286 /* Treat INIT-ACK as a special case during COOKIE-WAIT. */
4287 if (chunk->chunk_hdr->type == SCTP_CID_INIT_ACK &&
4288 !asoc->peer.i.init_tag) {
4289 sctp_initack_chunk_t *initack;
4290
4291 initack = (sctp_initack_chunk_t *)chunk->chunk_hdr;
4292 if (!sctp_chunk_length_valid(chunk,
4293 sizeof(sctp_initack_chunk_t)))
4294 abort->chunk_hdr->flags |= SCTP_CHUNK_FLAG_T;
4295 else {
4296 unsigned int inittag;
4297
4298 inittag = ntohl(initack->init_hdr.init_tag);
4299 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_INITTAG,
4300 SCTP_U32(inittag));
4301 }
4302 }
4303
4304 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4305 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
4306
4307 if (asoc->state <= SCTP_STATE_COOKIE_ECHOED) {
4308 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4309 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4310 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4311 SCTP_ERROR(ECONNREFUSED));
4312 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
4313 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4314 } else {
4315 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4316 SCTP_ERROR(ECONNABORTED));
4317 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4318 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4319 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
4320 }
4321 } else {
4322 packet = sctp_ootb_pkt_new(asoc, chunk);
4323
4324 if (!packet)
4325 goto nomem_pkt;
4326
4327 if (sctp_test_T_bit(abort))
4328 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
4329
4330 abort->skb->sk = ep->base.sk;
4331
4332 sctp_packet_append_chunk(packet, abort);
4333
4334 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
4335 SCTP_PACKET(packet));
4336
4337 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
4338 }
4339
4340 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4341
4342discard:
4343 sctp_sf_pdiscard(ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
4344 return SCTP_DISPOSITION_ABORT;
4345
4346nomem_pkt:
4347 sctp_chunk_free(abort);
4348nomem:
4349 return SCTP_DISPOSITION_NOMEM;
4350}
4351
4352/*
4353 * Handle a protocol violation when the chunk length is invalid.
4354 * "Invalid" length is identified as smaller than the minimal length a
4355 * given chunk can be. For example, a SACK chunk has invalid length
4356 * if its length is set to be smaller than the size of sctp_sack_chunk_t.
4357 *
4358 * We inform the other end by sending an ABORT with a Protocol Violation
4359 * error code.
4360 *
4361 * Section: Not specified
4362 * Verification Tag: Nothing to do
4363 * Inputs
4364 * (endpoint, asoc, chunk)
4365 *
4366 * Outputs
4367 * (reply_msg, msg_up, counters)
4368 *
4369 * Generate an ABORT chunk and terminate the association.
4370 */
4371static sctp_disposition_t sctp_sf_violation_chunklen(
4372 const struct sctp_endpoint *ep,
4373 const struct sctp_association *asoc,
4374 const sctp_subtype_t type,
4375 void *arg,
4376 sctp_cmd_seq_t *commands)
4377{
4378 static const char err_str[]="The following chunk had invalid length:";
4379
4380 return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
4381 sizeof(err_str));
4382}
4383
4384/*
4385 * Handle a protocol violation when the parameter length is invalid.
4386 * If the length is smaller than the minimum length of a given parameter,
4387 * or accumulated length in multi parameters exceeds the end of the chunk,
4388 * the length is considered as invalid.
4389 */
4390static sctp_disposition_t sctp_sf_violation_paramlen(
4391 const struct sctp_endpoint *ep,
4392 const struct sctp_association *asoc,
4393 const sctp_subtype_t type,
4394 void *arg, void *ext,
4395 sctp_cmd_seq_t *commands)
4396{
4397 struct sctp_chunk *chunk = arg;
4398 struct sctp_paramhdr *param = ext;
4399 struct sctp_chunk *abort = NULL;
4400
4401 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
4402 goto discard;
4403
4404 /* Make the abort chunk. */
4405 abort = sctp_make_violation_paramlen(asoc, chunk, param);
4406 if (!abort)
4407 goto nomem;
4408
4409 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4410 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
4411
4412 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4413 SCTP_ERROR(ECONNABORTED));
4414 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4415 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4416 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
4417 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4418
4419discard:
4420 sctp_sf_pdiscard(ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
4421 return SCTP_DISPOSITION_ABORT;
4422nomem:
4423 return SCTP_DISPOSITION_NOMEM;
4424}
4425
4426/* Handle a protocol violation when the peer trying to advance the
4427 * cumulative tsn ack to a point beyond the max tsn currently sent.
4428 *
4429 * We inform the other end by sending an ABORT with a Protocol Violation
4430 * error code.
4431 */
4432static sctp_disposition_t sctp_sf_violation_ctsn(
4433 const struct sctp_endpoint *ep,
4434 const struct sctp_association *asoc,
4435 const sctp_subtype_t type,
4436 void *arg,
4437 sctp_cmd_seq_t *commands)
4438{
4439 static const char err_str[]="The cumulative tsn ack beyond the max tsn currently sent:";
4440
4441 return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
4442 sizeof(err_str));
4443}
4444
4445/* Handle protocol violation of an invalid chunk bundling. For example,
4446 * when we have an association and we receive bundled INIT-ACK, or
4447 * SHUDOWN-COMPLETE, our peer is clearly violationg the "MUST NOT bundle"
4448 * statement from the specs. Additionally, there might be an attacker
4449 * on the path and we may not want to continue this communication.
4450 */
4451static sctp_disposition_t sctp_sf_violation_chunk(
4452 const struct sctp_endpoint *ep,
4453 const struct sctp_association *asoc,
4454 const sctp_subtype_t type,
4455 void *arg,
4456 sctp_cmd_seq_t *commands)
4457{
4458 static const char err_str[]="The following chunk violates protocol:";
4459
4460 if (!asoc)
4461 return sctp_sf_violation(ep, asoc, type, arg, commands);
4462
4463 return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
4464 sizeof(err_str));
4465}
4466/***************************************************************************
4467 * These are the state functions for handling primitive (Section 10) events.
4468 ***************************************************************************/
4469/*
4470 * sctp_sf_do_prm_asoc
4471 *
4472 * Section: 10.1 ULP-to-SCTP
4473 * B) Associate
4474 *
4475 * Format: ASSOCIATE(local SCTP instance name, destination transport addr,
4476 * outbound stream count)
4477 * -> association id [,destination transport addr list] [,outbound stream
4478 * count]
4479 *
4480 * This primitive allows the upper layer to initiate an association to a
4481 * specific peer endpoint.
4482 *
4483 * The peer endpoint shall be specified by one of the transport addresses
4484 * which defines the endpoint (see Section 1.4). If the local SCTP
4485 * instance has not been initialized, the ASSOCIATE is considered an
4486 * error.
4487 * [This is not relevant for the kernel implementation since we do all
4488 * initialization at boot time. It we hadn't initialized we wouldn't
4489 * get anywhere near this code.]
4490 *
4491 * An association id, which is a local handle to the SCTP association,
4492 * will be returned on successful establishment of the association. If
4493 * SCTP is not able to open an SCTP association with the peer endpoint,
4494 * an error is returned.
4495 * [In the kernel implementation, the struct sctp_association needs to
4496 * be created BEFORE causing this primitive to run.]
4497 *
4498 * Other association parameters may be returned, including the
4499 * complete destination transport addresses of the peer as well as the
4500 * outbound stream count of the local endpoint. One of the transport
4501 * address from the returned destination addresses will be selected by
4502 * the local endpoint as default primary path for sending SCTP packets
4503 * to this peer. The returned "destination transport addr list" can
4504 * be used by the ULP to change the default primary path or to force
4505 * sending a packet to a specific transport address. [All of this
4506 * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING
4507 * function.]
4508 *
4509 * Mandatory attributes:
4510 *
4511 * o local SCTP instance name - obtained from the INITIALIZE operation.
4512 * [This is the argument asoc.]
4513 * o destination transport addr - specified as one of the transport
4514 * addresses of the peer endpoint with which the association is to be
4515 * established.
4516 * [This is asoc->peer.active_path.]
4517 * o outbound stream count - the number of outbound streams the ULP
4518 * would like to open towards this peer endpoint.
4519 * [BUG: This is not currently implemented.]
4520 * Optional attributes:
4521 *
4522 * None.
4523 *
4524 * The return value is a disposition.
4525 */
4526sctp_disposition_t sctp_sf_do_prm_asoc(const struct sctp_endpoint *ep,
4527 const struct sctp_association *asoc,
4528 const sctp_subtype_t type,
4529 void *arg,
4530 sctp_cmd_seq_t *commands)
4531{
4532 struct sctp_chunk *repl;
4533 struct sctp_association* my_asoc;
4534
4535 /* The comment below says that we enter COOKIE-WAIT AFTER
4536 * sending the INIT, but that doesn't actually work in our
4537 * implementation...
4538 */
4539 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4540 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
4541
4542 /* RFC 2960 5.1 Normal Establishment of an Association
4543 *
4544 * A) "A" first sends an INIT chunk to "Z". In the INIT, "A"
4545 * must provide its Verification Tag (Tag_A) in the Initiate
4546 * Tag field. Tag_A SHOULD be a random number in the range of
4547 * 1 to 4294967295 (see 5.3.1 for Tag value selection). ...
4548 */
4549
4550 repl = sctp_make_init(asoc, &asoc->base.bind_addr, GFP_ATOMIC, 0);
4551 if (!repl)
4552 goto nomem;
4553
4554 /* Cast away the const modifier, as we want to just
4555 * rerun it through as a sideffect.
4556 */
4557 my_asoc = (struct sctp_association *)asoc;
4558 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(my_asoc));
4559
4560 /* Choose transport for INIT. */
4561 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
4562 SCTP_CHUNK(repl));
4563
4564 /* After sending the INIT, "A" starts the T1-init timer and
4565 * enters the COOKIE-WAIT state.
4566 */
4567 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4568 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4569 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
4570 return SCTP_DISPOSITION_CONSUME;
4571
4572nomem:
4573 return SCTP_DISPOSITION_NOMEM;
4574}
4575
4576/*
4577 * Process the SEND primitive.
4578 *
4579 * Section: 10.1 ULP-to-SCTP
4580 * E) Send
4581 *
4582 * Format: SEND(association id, buffer address, byte count [,context]
4583 * [,stream id] [,life time] [,destination transport address]
4584 * [,unorder flag] [,no-bundle flag] [,payload protocol-id] )
4585 * -> result
4586 *
4587 * This is the main method to send user data via SCTP.
4588 *
4589 * Mandatory attributes:
4590 *
4591 * o association id - local handle to the SCTP association
4592 *
4593 * o buffer address - the location where the user message to be
4594 * transmitted is stored;
4595 *
4596 * o byte count - The size of the user data in number of bytes;
4597 *
4598 * Optional attributes:
4599 *
4600 * o context - an optional 32 bit integer that will be carried in the
4601 * sending failure notification to the ULP if the transportation of
4602 * this User Message fails.
4603 *
4604 * o stream id - to indicate which stream to send the data on. If not
4605 * specified, stream 0 will be used.
4606 *
4607 * o life time - specifies the life time of the user data. The user data
4608 * will not be sent by SCTP after the life time expires. This
4609 * parameter can be used to avoid efforts to transmit stale
4610 * user messages. SCTP notifies the ULP if the data cannot be
4611 * initiated to transport (i.e. sent to the destination via SCTP's
4612 * send primitive) within the life time variable. However, the
4613 * user data will be transmitted if SCTP has attempted to transmit a
4614 * chunk before the life time expired.
4615 *
4616 * o destination transport address - specified as one of the destination
4617 * transport addresses of the peer endpoint to which this packet
4618 * should be sent. Whenever possible, SCTP should use this destination
4619 * transport address for sending the packets, instead of the current
4620 * primary path.
4621 *
4622 * o unorder flag - this flag, if present, indicates that the user
4623 * would like the data delivered in an unordered fashion to the peer
4624 * (i.e., the U flag is set to 1 on all DATA chunks carrying this
4625 * message).
4626 *
4627 * o no-bundle flag - instructs SCTP not to bundle this user data with
4628 * other outbound DATA chunks. SCTP MAY still bundle even when
4629 * this flag is present, when faced with network congestion.
4630 *
4631 * o payload protocol-id - A 32 bit unsigned integer that is to be
4632 * passed to the peer indicating the type of payload protocol data
4633 * being transmitted. This value is passed as opaque data by SCTP.
4634 *
4635 * The return value is the disposition.
4636 */
4637sctp_disposition_t sctp_sf_do_prm_send(const struct sctp_endpoint *ep,
4638 const struct sctp_association *asoc,
4639 const sctp_subtype_t type,
4640 void *arg,
4641 sctp_cmd_seq_t *commands)
4642{
4643 struct sctp_datamsg *msg = arg;
4644
4645 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_MSG, SCTP_DATAMSG(msg));
4646 return SCTP_DISPOSITION_CONSUME;
4647}
4648
4649/*
4650 * Process the SHUTDOWN primitive.
4651 *
4652 * Section: 10.1:
4653 * C) Shutdown
4654 *
4655 * Format: SHUTDOWN(association id)
4656 * -> result
4657 *
4658 * Gracefully closes an association. Any locally queued user data
4659 * will be delivered to the peer. The association will be terminated only
4660 * after the peer acknowledges all the SCTP packets sent. A success code
4661 * will be returned on successful termination of the association. If
4662 * attempting to terminate the association results in a failure, an error
4663 * code shall be returned.
4664 *
4665 * Mandatory attributes:
4666 *
4667 * o association id - local handle to the SCTP association
4668 *
4669 * Optional attributes:
4670 *
4671 * None.
4672 *
4673 * The return value is the disposition.
4674 */
4675sctp_disposition_t sctp_sf_do_9_2_prm_shutdown(
4676 const struct sctp_endpoint *ep,
4677 const struct sctp_association *asoc,
4678 const sctp_subtype_t type,
4679 void *arg,
4680 sctp_cmd_seq_t *commands)
4681{
4682 int disposition;
4683
4684 /* From 9.2 Shutdown of an Association
4685 * Upon receipt of the SHUTDOWN primitive from its upper
4686 * layer, the endpoint enters SHUTDOWN-PENDING state and
4687 * remains there until all outstanding data has been
4688 * acknowledged by its peer. The endpoint accepts no new data
4689 * from its upper layer, but retransmits data to the far end
4690 * if necessary to fill gaps.
4691 */
4692 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4693 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
4694
4695 disposition = SCTP_DISPOSITION_CONSUME;
4696 if (sctp_outq_is_empty(&asoc->outqueue)) {
4697 disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type,
4698 arg, commands);
4699 }
4700 return disposition;
4701}
4702
4703/*
4704 * Process the ABORT primitive.
4705 *
4706 * Section: 10.1:
4707 * C) Abort
4708 *
4709 * Format: Abort(association id [, cause code])
4710 * -> result
4711 *
4712 * Ungracefully closes an association. Any locally queued user data
4713 * will be discarded and an ABORT chunk is sent to the peer. A success code
4714 * will be returned on successful abortion of the association. If
4715 * attempting to abort the association results in a failure, an error
4716 * code shall be returned.
4717 *
4718 * Mandatory attributes:
4719 *
4720 * o association id - local handle to the SCTP association
4721 *
4722 * Optional attributes:
4723 *
4724 * o cause code - reason of the abort to be passed to the peer
4725 *
4726 * None.
4727 *
4728 * The return value is the disposition.
4729 */
4730sctp_disposition_t sctp_sf_do_9_1_prm_abort(
4731 const struct sctp_endpoint *ep,
4732 const struct sctp_association *asoc,
4733 const sctp_subtype_t type,
4734 void *arg,
4735 sctp_cmd_seq_t *commands)
4736{
4737 /* From 9.1 Abort of an Association
4738 * Upon receipt of the ABORT primitive from its upper
4739 * layer, the endpoint enters CLOSED state and
4740 * discard all outstanding data has been
4741 * acknowledged by its peer. The endpoint accepts no new data
4742 * from its upper layer, but retransmits data to the far end
4743 * if necessary to fill gaps.
4744 */
4745 struct sctp_chunk *abort = arg;
4746 sctp_disposition_t retval;
4747
4748 retval = SCTP_DISPOSITION_CONSUME;
4749
4750 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4751
4752 /* Even if we can't send the ABORT due to low memory delete the
4753 * TCB. This is a departure from our typical NOMEM handling.
4754 */
4755
4756 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4757 SCTP_ERROR(ECONNABORTED));
4758 /* Delete the established association. */
4759 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4760 SCTP_PERR(SCTP_ERROR_USER_ABORT));
4761
4762 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4763 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
4764
4765 return retval;
4766}
4767
4768/* We tried an illegal operation on an association which is closed. */
4769sctp_disposition_t sctp_sf_error_closed(const struct sctp_endpoint *ep,
4770 const struct sctp_association *asoc,
4771 const sctp_subtype_t type,
4772 void *arg,
4773 sctp_cmd_seq_t *commands)
4774{
4775 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, SCTP_ERROR(-EINVAL));
4776 return SCTP_DISPOSITION_CONSUME;
4777}
4778
4779/* We tried an illegal operation on an association which is shutting
4780 * down.
4781 */
4782sctp_disposition_t sctp_sf_error_shutdown(const struct sctp_endpoint *ep,
4783 const struct sctp_association *asoc,
4784 const sctp_subtype_t type,
4785 void *arg,
4786 sctp_cmd_seq_t *commands)
4787{
4788 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR,
4789 SCTP_ERROR(-ESHUTDOWN));
4790 return SCTP_DISPOSITION_CONSUME;
4791}
4792
4793/*
4794 * sctp_cookie_wait_prm_shutdown
4795 *
4796 * Section: 4 Note: 2
4797 * Verification Tag:
4798 * Inputs
4799 * (endpoint, asoc)
4800 *
4801 * The RFC does not explicitly address this issue, but is the route through the
4802 * state table when someone issues a shutdown while in COOKIE_WAIT state.
4803 *
4804 * Outputs
4805 * (timers)
4806 */
4807sctp_disposition_t sctp_sf_cookie_wait_prm_shutdown(
4808 const struct sctp_endpoint *ep,
4809 const struct sctp_association *asoc,
4810 const sctp_subtype_t type,
4811 void *arg,
4812 sctp_cmd_seq_t *commands)
4813{
4814 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4815 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4816
4817 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4818 SCTP_STATE(SCTP_STATE_CLOSED));
4819
4820 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
4821
4822 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
4823
4824 return SCTP_DISPOSITION_DELETE_TCB;
4825}
4826
4827/*
4828 * sctp_cookie_echoed_prm_shutdown
4829 *
4830 * Section: 4 Note: 2
4831 * Verification Tag:
4832 * Inputs
4833 * (endpoint, asoc)
4834 *
4835 * The RFC does not explcitly address this issue, but is the route through the
4836 * state table when someone issues a shutdown while in COOKIE_ECHOED state.
4837 *
4838 * Outputs
4839 * (timers)
4840 */
4841sctp_disposition_t sctp_sf_cookie_echoed_prm_shutdown(
4842 const struct sctp_endpoint *ep,
4843 const struct sctp_association *asoc,
4844 const sctp_subtype_t type,
4845 void *arg, sctp_cmd_seq_t *commands)
4846{
4847 /* There is a single T1 timer, so we should be able to use
4848 * common function with the COOKIE-WAIT state.
4849 */
4850 return sctp_sf_cookie_wait_prm_shutdown(ep, asoc, type, arg, commands);
4851}
4852
4853/*
4854 * sctp_sf_cookie_wait_prm_abort
4855 *
4856 * Section: 4 Note: 2
4857 * Verification Tag:
4858 * Inputs
4859 * (endpoint, asoc)
4860 *
4861 * The RFC does not explicitly address this issue, but is the route through the
4862 * state table when someone issues an abort while in COOKIE_WAIT state.
4863 *
4864 * Outputs
4865 * (timers)
4866 */
4867sctp_disposition_t sctp_sf_cookie_wait_prm_abort(
4868 const struct sctp_endpoint *ep,
4869 const struct sctp_association *asoc,
4870 const sctp_subtype_t type,
4871 void *arg,
4872 sctp_cmd_seq_t *commands)
4873{
4874 struct sctp_chunk *abort = arg;
4875 sctp_disposition_t retval;
4876
4877 /* Stop T1-init timer */
4878 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4879 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4880 retval = SCTP_DISPOSITION_CONSUME;
4881
4882 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4883
4884 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4885 SCTP_STATE(SCTP_STATE_CLOSED));
4886
4887 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4888
4889 /* Even if we can't send the ABORT due to low memory delete the
4890 * TCB. This is a departure from our typical NOMEM handling.
4891 */
4892
4893 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4894 SCTP_ERROR(ECONNREFUSED));
4895 /* Delete the established association. */
4896 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
4897 SCTP_PERR(SCTP_ERROR_USER_ABORT));
4898
4899 return retval;
4900}
4901
4902/*
4903 * sctp_sf_cookie_echoed_prm_abort
4904 *
4905 * Section: 4 Note: 3
4906 * Verification Tag:
4907 * Inputs
4908 * (endpoint, asoc)
4909 *
4910 * The RFC does not explcitly address this issue, but is the route through the
4911 * state table when someone issues an abort while in COOKIE_ECHOED state.
4912 *
4913 * Outputs
4914 * (timers)
4915 */
4916sctp_disposition_t sctp_sf_cookie_echoed_prm_abort(
4917 const struct sctp_endpoint *ep,
4918 const struct sctp_association *asoc,
4919 const sctp_subtype_t type,
4920 void *arg,
4921 sctp_cmd_seq_t *commands)
4922{
4923 /* There is a single T1 timer, so we should be able to use
4924 * common function with the COOKIE-WAIT state.
4925 */
4926 return sctp_sf_cookie_wait_prm_abort(ep, asoc, type, arg, commands);
4927}
4928
4929/*
4930 * sctp_sf_shutdown_pending_prm_abort
4931 *
4932 * Inputs
4933 * (endpoint, asoc)
4934 *
4935 * The RFC does not explicitly address this issue, but is the route through the
4936 * state table when someone issues an abort while in SHUTDOWN-PENDING state.
4937 *
4938 * Outputs
4939 * (timers)
4940 */
4941sctp_disposition_t sctp_sf_shutdown_pending_prm_abort(
4942 const struct sctp_endpoint *ep,
4943 const struct sctp_association *asoc,
4944 const sctp_subtype_t type,
4945 void *arg,
4946 sctp_cmd_seq_t *commands)
4947{
4948 /* Stop the T5-shutdown guard timer. */
4949 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4950 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4951
4952 return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands);
4953}
4954
4955/*
4956 * sctp_sf_shutdown_sent_prm_abort
4957 *
4958 * Inputs
4959 * (endpoint, asoc)
4960 *
4961 * The RFC does not explicitly address this issue, but is the route through the
4962 * state table when someone issues an abort while in SHUTDOWN-SENT state.
4963 *
4964 * Outputs
4965 * (timers)
4966 */
4967sctp_disposition_t sctp_sf_shutdown_sent_prm_abort(
4968 const struct sctp_endpoint *ep,
4969 const struct sctp_association *asoc,
4970 const sctp_subtype_t type,
4971 void *arg,
4972 sctp_cmd_seq_t *commands)
4973{
4974 /* Stop the T2-shutdown timer. */
4975 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4976 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4977
4978 /* Stop the T5-shutdown guard timer. */
4979 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4980 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4981
4982 return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands);
4983}
4984
4985/*
4986 * sctp_sf_cookie_echoed_prm_abort
4987 *
4988 * Inputs
4989 * (endpoint, asoc)
4990 *
4991 * The RFC does not explcitly address this issue, but is the route through the
4992 * state table when someone issues an abort while in COOKIE_ECHOED state.
4993 *
4994 * Outputs
4995 * (timers)
4996 */
4997sctp_disposition_t sctp_sf_shutdown_ack_sent_prm_abort(
4998 const struct sctp_endpoint *ep,
4999 const struct sctp_association *asoc,
5000 const sctp_subtype_t type,
5001 void *arg,
5002 sctp_cmd_seq_t *commands)
5003{
5004 /* The same T2 timer, so we should be able to use
5005 * common function with the SHUTDOWN-SENT state.
5006 */
5007 return sctp_sf_shutdown_sent_prm_abort(ep, asoc, type, arg, commands);
5008}
5009
5010/*
5011 * Process the REQUESTHEARTBEAT primitive
5012 *
5013 * 10.1 ULP-to-SCTP
5014 * J) Request Heartbeat
5015 *
5016 * Format: REQUESTHEARTBEAT(association id, destination transport address)
5017 *
5018 * -> result
5019 *
5020 * Instructs the local endpoint to perform a HeartBeat on the specified
5021 * destination transport address of the given association. The returned
5022 * result should indicate whether the transmission of the HEARTBEAT
5023 * chunk to the destination address is successful.
5024 *
5025 * Mandatory attributes:
5026 *
5027 * o association id - local handle to the SCTP association
5028 *
5029 * o destination transport address - the transport address of the
5030 * association on which a heartbeat should be issued.
5031 */
5032sctp_disposition_t sctp_sf_do_prm_requestheartbeat(
5033 const struct sctp_endpoint *ep,
5034 const struct sctp_association *asoc,
5035 const sctp_subtype_t type,
5036 void *arg,
5037 sctp_cmd_seq_t *commands)
5038{
5039 if (SCTP_DISPOSITION_NOMEM == sctp_sf_heartbeat(ep, asoc, type,
5040 (struct sctp_transport *)arg, commands))
5041 return SCTP_DISPOSITION_NOMEM;
5042
5043 /*
5044 * RFC 2960 (bis), section 8.3
5045 *
5046 * D) Request an on-demand HEARTBEAT on a specific destination
5047 * transport address of a given association.
5048 *
5049 * The endpoint should increment the respective error counter of
5050 * the destination transport address each time a HEARTBEAT is sent
5051 * to that address and not acknowledged within one RTO.
5052 *
5053 */
5054 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_HB_SENT,
5055 SCTP_TRANSPORT(arg));
5056 return SCTP_DISPOSITION_CONSUME;
5057}
5058
5059/*
5060 * ADDIP Section 4.1 ASCONF Chunk Procedures
5061 * When an endpoint has an ASCONF signaled change to be sent to the
5062 * remote endpoint it should do A1 to A9
5063 */
5064sctp_disposition_t sctp_sf_do_prm_asconf(const struct sctp_endpoint *ep,
5065 const struct sctp_association *asoc,
5066 const sctp_subtype_t type,
5067 void *arg,
5068 sctp_cmd_seq_t *commands)
5069{
5070 struct sctp_chunk *chunk = arg;
5071
5072 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
5073 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
5074 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
5075 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
5076 return SCTP_DISPOSITION_CONSUME;
5077}
5078
5079/*
5080 * Ignore the primitive event
5081 *
5082 * The return value is the disposition of the primitive.
5083 */
5084sctp_disposition_t sctp_sf_ignore_primitive(
5085 const struct sctp_endpoint *ep,
5086 const struct sctp_association *asoc,
5087 const sctp_subtype_t type,
5088 void *arg,
5089 sctp_cmd_seq_t *commands)
5090{
5091 SCTP_DEBUG_PRINTK("Primitive type %d is ignored.\n", type.primitive);
5092 return SCTP_DISPOSITION_DISCARD;
5093}
5094
5095/***************************************************************************
5096 * These are the state functions for the OTHER events.
5097 ***************************************************************************/
5098
5099/*
5100 * When the SCTP stack has no more user data to send or retransmit, this
5101 * notification is given to the user. Also, at the time when a user app
5102 * subscribes to this event, if there is no data to be sent or
5103 * retransmit, the stack will immediately send up this notification.
5104 */
5105sctp_disposition_t sctp_sf_do_no_pending_tsn(
5106 const struct sctp_endpoint *ep,
5107 const struct sctp_association *asoc,
5108 const sctp_subtype_t type,
5109 void *arg,
5110 sctp_cmd_seq_t *commands)
5111{
5112 struct sctp_ulpevent *event;
5113
5114 event = sctp_ulpevent_make_sender_dry_event(asoc, GFP_ATOMIC);
5115 if (!event)
5116 return SCTP_DISPOSITION_NOMEM;
5117
5118 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(event));
5119
5120 return SCTP_DISPOSITION_CONSUME;
5121}
5122
5123/*
5124 * Start the shutdown negotiation.
5125 *
5126 * From Section 9.2:
5127 * Once all its outstanding data has been acknowledged, the endpoint
5128 * shall send a SHUTDOWN chunk to its peer including in the Cumulative
5129 * TSN Ack field the last sequential TSN it has received from the peer.
5130 * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT
5131 * state. If the timer expires, the endpoint must re-send the SHUTDOWN
5132 * with the updated last sequential TSN received from its peer.
5133 *
5134 * The return value is the disposition.
5135 */
5136sctp_disposition_t sctp_sf_do_9_2_start_shutdown(
5137 const struct sctp_endpoint *ep,
5138 const struct sctp_association *asoc,
5139 const sctp_subtype_t type,
5140 void *arg,
5141 sctp_cmd_seq_t *commands)
5142{
5143 struct sctp_chunk *reply;
5144
5145 /* Once all its outstanding data has been acknowledged, the
5146 * endpoint shall send a SHUTDOWN chunk to its peer including
5147 * in the Cumulative TSN Ack field the last sequential TSN it
5148 * has received from the peer.
5149 */
5150 reply = sctp_make_shutdown(asoc, NULL);
5151 if (!reply)
5152 goto nomem;
5153
5154 /* Set the transport for the SHUTDOWN chunk and the timeout for the
5155 * T2-shutdown timer.
5156 */
5157 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5158
5159 /* It shall then start the T2-shutdown timer */
5160 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
5161 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5162
5163 /* RFC 4960 Section 9.2
5164 * The sender of the SHUTDOWN MAY also start an overall guard timer
5165 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5166 */
5167 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5168 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5169
5170 if (asoc->autoclose)
5171 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5172 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
5173
5174 /* and enter the SHUTDOWN-SENT state. */
5175 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5176 SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT));
5177
5178 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5179 *
5180 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
5181 * or SHUTDOWN-ACK.
5182 */
5183 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
5184
5185 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5186
5187 return SCTP_DISPOSITION_CONSUME;
5188
5189nomem:
5190 return SCTP_DISPOSITION_NOMEM;
5191}
5192
5193/*
5194 * Generate a SHUTDOWN ACK now that everything is SACK'd.
5195 *
5196 * From Section 9.2:
5197 *
5198 * If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5199 * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own,
5200 * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the
5201 * endpoint must re-send the SHUTDOWN ACK.
5202 *
5203 * The return value is the disposition.
5204 */
5205sctp_disposition_t sctp_sf_do_9_2_shutdown_ack(
5206 const struct sctp_endpoint *ep,
5207 const struct sctp_association *asoc,
5208 const sctp_subtype_t type,
5209 void *arg,
5210 sctp_cmd_seq_t *commands)
5211{
5212 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
5213 struct sctp_chunk *reply;
5214
5215 /* There are 2 ways of getting here:
5216 * 1) called in response to a SHUTDOWN chunk
5217 * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued.
5218 *
5219 * For the case (2), the arg parameter is set to NULL. We need
5220 * to check that we have a chunk before accessing it's fields.
5221 */
5222 if (chunk) {
5223 if (!sctp_vtag_verify(chunk, asoc))
5224 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
5225
5226 /* Make sure that the SHUTDOWN chunk has a valid length. */
5227 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_shutdown_chunk_t)))
5228 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
5229 commands);
5230 }
5231
5232 /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5233 * shall send a SHUTDOWN ACK ...
5234 */
5235 reply = sctp_make_shutdown_ack(asoc, chunk);
5236 if (!reply)
5237 goto nomem;
5238
5239 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
5240 * the T2-shutdown timer.
5241 */
5242 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5243
5244 /* and start/restart a T2-shutdown timer of its own, */
5245 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5246 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5247
5248 if (asoc->autoclose)
5249 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5250 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
5251
5252 /* Enter the SHUTDOWN-ACK-SENT state. */
5253 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5254 SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT));
5255
5256 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5257 *
5258 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
5259 * or SHUTDOWN-ACK.
5260 */
5261 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
5262
5263 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5264
5265 return SCTP_DISPOSITION_CONSUME;
5266
5267nomem:
5268 return SCTP_DISPOSITION_NOMEM;
5269}
5270
5271/*
5272 * Ignore the event defined as other
5273 *
5274 * The return value is the disposition of the event.
5275 */
5276sctp_disposition_t sctp_sf_ignore_other(const struct sctp_endpoint *ep,
5277 const struct sctp_association *asoc,
5278 const sctp_subtype_t type,
5279 void *arg,
5280 sctp_cmd_seq_t *commands)
5281{
5282 SCTP_DEBUG_PRINTK("The event other type %d is ignored\n", type.other);
5283 return SCTP_DISPOSITION_DISCARD;
5284}
5285
5286/************************************************************
5287 * These are the state functions for handling timeout events.
5288 ************************************************************/
5289
5290/*
5291 * RTX Timeout
5292 *
5293 * Section: 6.3.3 Handle T3-rtx Expiration
5294 *
5295 * Whenever the retransmission timer T3-rtx expires for a destination
5296 * address, do the following:
5297 * [See below]
5298 *
5299 * The return value is the disposition of the chunk.
5300 */
5301sctp_disposition_t sctp_sf_do_6_3_3_rtx(const struct sctp_endpoint *ep,
5302 const struct sctp_association *asoc,
5303 const sctp_subtype_t type,
5304 void *arg,
5305 sctp_cmd_seq_t *commands)
5306{
5307 struct sctp_transport *transport = arg;
5308
5309 SCTP_INC_STATS(SCTP_MIB_T3_RTX_EXPIREDS);
5310
5311 if (asoc->overall_error_count >= asoc->max_retrans) {
5312 if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING) {
5313 /*
5314 * We are here likely because the receiver had its rwnd
5315 * closed for a while and we have not been able to
5316 * transmit the locally queued data within the maximum
5317 * retransmission attempts limit. Start the T5
5318 * shutdown guard timer to give the receiver one last
5319 * chance and some additional time to recover before
5320 * aborting.
5321 */
5322 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START_ONCE,
5323 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5324 } else {
5325 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5326 SCTP_ERROR(ETIMEDOUT));
5327 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5328 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5329 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5330 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
5331 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
5332 return SCTP_DISPOSITION_DELETE_TCB;
5333 }
5334 }
5335
5336 /* E1) For the destination address for which the timer
5337 * expires, adjust its ssthresh with rules defined in Section
5338 * 7.2.3 and set the cwnd <- MTU.
5339 */
5340
5341 /* E2) For the destination address for which the timer
5342 * expires, set RTO <- RTO * 2 ("back off the timer"). The
5343 * maximum value discussed in rule C7 above (RTO.max) may be
5344 * used to provide an upper bound to this doubling operation.
5345 */
5346
5347 /* E3) Determine how many of the earliest (i.e., lowest TSN)
5348 * outstanding DATA chunks for the address for which the
5349 * T3-rtx has expired will fit into a single packet, subject
5350 * to the MTU constraint for the path corresponding to the
5351 * destination transport address to which the retransmission
5352 * is being sent (this may be different from the address for
5353 * which the timer expires [see Section 6.4]). Call this
5354 * value K. Bundle and retransmit those K DATA chunks in a
5355 * single packet to the destination endpoint.
5356 *
5357 * Note: Any DATA chunks that were sent to the address for
5358 * which the T3-rtx timer expired but did not fit in one MTU
5359 * (rule E3 above), should be marked for retransmission and
5360 * sent as soon as cwnd allows (normally when a SACK arrives).
5361 */
5362
5363 /* Do some failure management (Section 8.2). */
5364 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
5365
5366 /* NB: Rules E4 and F1 are implicit in R1. */
5367 sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN, SCTP_TRANSPORT(transport));
5368
5369 return SCTP_DISPOSITION_CONSUME;
5370}
5371
5372/*
5373 * Generate delayed SACK on timeout
5374 *
5375 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
5376 *
5377 * The guidelines on delayed acknowledgement algorithm specified in
5378 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
5379 * acknowledgement SHOULD be generated for at least every second packet
5380 * (not every second DATA chunk) received, and SHOULD be generated
5381 * within 200 ms of the arrival of any unacknowledged DATA chunk. In
5382 * some situations it may be beneficial for an SCTP transmitter to be
5383 * more conservative than the algorithms detailed in this document
5384 * allow. However, an SCTP transmitter MUST NOT be more aggressive than
5385 * the following algorithms allow.
5386 */
5387sctp_disposition_t sctp_sf_do_6_2_sack(const struct sctp_endpoint *ep,
5388 const struct sctp_association *asoc,
5389 const sctp_subtype_t type,
5390 void *arg,
5391 sctp_cmd_seq_t *commands)
5392{
5393 SCTP_INC_STATS(SCTP_MIB_DELAY_SACK_EXPIREDS);
5394 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
5395 return SCTP_DISPOSITION_CONSUME;
5396}
5397
5398/*
5399 * sctp_sf_t1_init_timer_expire
5400 *
5401 * Section: 4 Note: 2
5402 * Verification Tag:
5403 * Inputs
5404 * (endpoint, asoc)
5405 *
5406 * RFC 2960 Section 4 Notes
5407 * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT
5408 * and re-start the T1-init timer without changing state. This MUST
5409 * be repeated up to 'Max.Init.Retransmits' times. After that, the
5410 * endpoint MUST abort the initialization process and report the
5411 * error to SCTP user.
5412 *
5413 * Outputs
5414 * (timers, events)
5415 *
5416 */
5417sctp_disposition_t sctp_sf_t1_init_timer_expire(const struct sctp_endpoint *ep,
5418 const struct sctp_association *asoc,
5419 const sctp_subtype_t type,
5420 void *arg,
5421 sctp_cmd_seq_t *commands)
5422{
5423 struct sctp_chunk *repl = NULL;
5424 struct sctp_bind_addr *bp;
5425 int attempts = asoc->init_err_counter + 1;
5426
5427 SCTP_DEBUG_PRINTK("Timer T1 expired (INIT).\n");
5428 SCTP_INC_STATS(SCTP_MIB_T1_INIT_EXPIREDS);
5429
5430 if (attempts <= asoc->max_init_attempts) {
5431 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
5432 repl = sctp_make_init(asoc, bp, GFP_ATOMIC, 0);
5433 if (!repl)
5434 return SCTP_DISPOSITION_NOMEM;
5435
5436 /* Choose transport for INIT. */
5437 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
5438 SCTP_CHUNK(repl));
5439
5440 /* Issue a sideeffect to do the needed accounting. */
5441 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_RESTART,
5442 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
5443
5444 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
5445 } else {
5446 SCTP_DEBUG_PRINTK("Giving up on INIT, attempts: %d"
5447 " max_init_attempts: %d\n",
5448 attempts, asoc->max_init_attempts);
5449 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5450 SCTP_ERROR(ETIMEDOUT));
5451 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
5452 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5453 return SCTP_DISPOSITION_DELETE_TCB;
5454 }
5455
5456 return SCTP_DISPOSITION_CONSUME;
5457}
5458
5459/*
5460 * sctp_sf_t1_cookie_timer_expire
5461 *
5462 * Section: 4 Note: 2
5463 * Verification Tag:
5464 * Inputs
5465 * (endpoint, asoc)
5466 *
5467 * RFC 2960 Section 4 Notes
5468 * 3) If the T1-cookie timer expires, the endpoint MUST retransmit
5469 * COOKIE ECHO and re-start the T1-cookie timer without changing
5470 * state. This MUST be repeated up to 'Max.Init.Retransmits' times.
5471 * After that, the endpoint MUST abort the initialization process and
5472 * report the error to SCTP user.
5473 *
5474 * Outputs
5475 * (timers, events)
5476 *
5477 */
5478sctp_disposition_t sctp_sf_t1_cookie_timer_expire(const struct sctp_endpoint *ep,
5479 const struct sctp_association *asoc,
5480 const sctp_subtype_t type,
5481 void *arg,
5482 sctp_cmd_seq_t *commands)
5483{
5484 struct sctp_chunk *repl = NULL;
5485 int attempts = asoc->init_err_counter + 1;
5486
5487 SCTP_DEBUG_PRINTK("Timer T1 expired (COOKIE-ECHO).\n");
5488 SCTP_INC_STATS(SCTP_MIB_T1_COOKIE_EXPIREDS);
5489
5490 if (attempts <= asoc->max_init_attempts) {
5491 repl = sctp_make_cookie_echo(asoc, NULL);
5492 if (!repl)
5493 return SCTP_DISPOSITION_NOMEM;
5494
5495 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
5496 SCTP_CHUNK(repl));
5497 /* Issue a sideeffect to do the needed accounting. */
5498 sctp_add_cmd_sf(commands, SCTP_CMD_COOKIEECHO_RESTART,
5499 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
5500
5501 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
5502 } else {
5503 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5504 SCTP_ERROR(ETIMEDOUT));
5505 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
5506 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5507 return SCTP_DISPOSITION_DELETE_TCB;
5508 }
5509
5510 return SCTP_DISPOSITION_CONSUME;
5511}
5512
5513/* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN
5514 * with the updated last sequential TSN received from its peer.
5515 *
5516 * An endpoint should limit the number of retransmissions of the
5517 * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'.
5518 * If this threshold is exceeded the endpoint should destroy the TCB and
5519 * MUST report the peer endpoint unreachable to the upper layer (and
5520 * thus the association enters the CLOSED state). The reception of any
5521 * packet from its peer (i.e. as the peer sends all of its queued DATA
5522 * chunks) should clear the endpoint's retransmission count and restart
5523 * the T2-Shutdown timer, giving its peer ample opportunity to transmit
5524 * all of its queued DATA chunks that have not yet been sent.
5525 */
5526sctp_disposition_t sctp_sf_t2_timer_expire(const struct sctp_endpoint *ep,
5527 const struct sctp_association *asoc,
5528 const sctp_subtype_t type,
5529 void *arg,
5530 sctp_cmd_seq_t *commands)
5531{
5532 struct sctp_chunk *reply = NULL;
5533
5534 SCTP_DEBUG_PRINTK("Timer T2 expired.\n");
5535 SCTP_INC_STATS(SCTP_MIB_T2_SHUTDOWN_EXPIREDS);
5536
5537 ((struct sctp_association *)asoc)->shutdown_retries++;
5538
5539 if (asoc->overall_error_count >= asoc->max_retrans) {
5540 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5541 SCTP_ERROR(ETIMEDOUT));
5542 /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5543 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5544 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5545 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
5546 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
5547 return SCTP_DISPOSITION_DELETE_TCB;
5548 }
5549
5550 switch (asoc->state) {
5551 case SCTP_STATE_SHUTDOWN_SENT:
5552 reply = sctp_make_shutdown(asoc, NULL);
5553 break;
5554
5555 case SCTP_STATE_SHUTDOWN_ACK_SENT:
5556 reply = sctp_make_shutdown_ack(asoc, NULL);
5557 break;
5558
5559 default:
5560 BUG();
5561 break;
5562 }
5563
5564 if (!reply)
5565 goto nomem;
5566
5567 /* Do some failure management (Section 8.2).
5568 * If we remove the transport an SHUTDOWN was last sent to, don't
5569 * do failure management.
5570 */
5571 if (asoc->shutdown_last_sent_to)
5572 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
5573 SCTP_TRANSPORT(asoc->shutdown_last_sent_to));
5574
5575 /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for
5576 * the T2-shutdown timer.
5577 */
5578 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5579
5580 /* Restart the T2-shutdown timer. */
5581 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5582 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5583 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5584 return SCTP_DISPOSITION_CONSUME;
5585
5586nomem:
5587 return SCTP_DISPOSITION_NOMEM;
5588}
5589
5590/*
5591 * ADDIP Section 4.1 ASCONF CHunk Procedures
5592 * If the T4 RTO timer expires the endpoint should do B1 to B5
5593 */
5594sctp_disposition_t sctp_sf_t4_timer_expire(
5595 const struct sctp_endpoint *ep,
5596 const struct sctp_association *asoc,
5597 const sctp_subtype_t type,
5598 void *arg,
5599 sctp_cmd_seq_t *commands)
5600{
5601 struct sctp_chunk *chunk = asoc->addip_last_asconf;
5602 struct sctp_transport *transport = chunk->transport;
5603
5604 SCTP_INC_STATS(SCTP_MIB_T4_RTO_EXPIREDS);
5605
5606 /* ADDIP 4.1 B1) Increment the error counters and perform path failure
5607 * detection on the appropriate destination address as defined in
5608 * RFC2960 [5] section 8.1 and 8.2.
5609 */
5610 if (transport)
5611 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
5612 SCTP_TRANSPORT(transport));
5613
5614 /* Reconfig T4 timer and transport. */
5615 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
5616
5617 /* ADDIP 4.1 B2) Increment the association error counters and perform
5618 * endpoint failure detection on the association as defined in
5619 * RFC2960 [5] section 8.1 and 8.2.
5620 * association error counter is incremented in SCTP_CMD_STRIKE.
5621 */
5622 if (asoc->overall_error_count >= asoc->max_retrans) {
5623 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5624 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
5625 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5626 SCTP_ERROR(ETIMEDOUT));
5627 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5628 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5629 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
5630 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
5631 return SCTP_DISPOSITION_ABORT;
5632 }
5633
5634 /* ADDIP 4.1 B3) Back-off the destination address RTO value to which
5635 * the ASCONF chunk was sent by doubling the RTO timer value.
5636 * This is done in SCTP_CMD_STRIKE.
5637 */
5638
5639 /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible
5640 * choose an alternate destination address (please refer to RFC2960
5641 * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this
5642 * chunk, it MUST be the same (including its serial number) as the last
5643 * ASCONF sent.
5644 */
5645 sctp_chunk_hold(asoc->addip_last_asconf);
5646 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
5647 SCTP_CHUNK(asoc->addip_last_asconf));
5648
5649 /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different
5650 * destination is selected, then the RTO used will be that of the new
5651 * destination address.
5652 */
5653 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5654 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
5655
5656 return SCTP_DISPOSITION_CONSUME;
5657}
5658
5659/* sctpimpguide-05 Section 2.12.2
5660 * The sender of the SHUTDOWN MAY also start an overall guard timer
5661 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5662 * At the expiration of this timer the sender SHOULD abort the association
5663 * by sending an ABORT chunk.
5664 */
5665sctp_disposition_t sctp_sf_t5_timer_expire(const struct sctp_endpoint *ep,
5666 const struct sctp_association *asoc,
5667 const sctp_subtype_t type,
5668 void *arg,
5669 sctp_cmd_seq_t *commands)
5670{
5671 struct sctp_chunk *reply = NULL;
5672
5673 SCTP_DEBUG_PRINTK("Timer T5 expired.\n");
5674 SCTP_INC_STATS(SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS);
5675
5676 reply = sctp_make_abort(asoc, NULL, 0);
5677 if (!reply)
5678 goto nomem;
5679
5680 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5681 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5682 SCTP_ERROR(ETIMEDOUT));
5683 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5684 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5685
5686 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
5687 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
5688
5689 return SCTP_DISPOSITION_DELETE_TCB;
5690nomem:
5691 return SCTP_DISPOSITION_NOMEM;
5692}
5693
5694/* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires,
5695 * the association is automatically closed by starting the shutdown process.
5696 * The work that needs to be done is same as when SHUTDOWN is initiated by
5697 * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown().
5698 */
5699sctp_disposition_t sctp_sf_autoclose_timer_expire(
5700 const struct sctp_endpoint *ep,
5701 const struct sctp_association *asoc,
5702 const sctp_subtype_t type,
5703 void *arg,
5704 sctp_cmd_seq_t *commands)
5705{
5706 int disposition;
5707
5708 SCTP_INC_STATS(SCTP_MIB_AUTOCLOSE_EXPIREDS);
5709
5710 /* From 9.2 Shutdown of an Association
5711 * Upon receipt of the SHUTDOWN primitive from its upper
5712 * layer, the endpoint enters SHUTDOWN-PENDING state and
5713 * remains there until all outstanding data has been
5714 * acknowledged by its peer. The endpoint accepts no new data
5715 * from its upper layer, but retransmits data to the far end
5716 * if necessary to fill gaps.
5717 */
5718 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5719 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
5720
5721 disposition = SCTP_DISPOSITION_CONSUME;
5722 if (sctp_outq_is_empty(&asoc->outqueue)) {
5723 disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type,
5724 arg, commands);
5725 }
5726 return disposition;
5727}
5728
5729/*****************************************************************************
5730 * These are sa state functions which could apply to all types of events.
5731 ****************************************************************************/
5732
5733/*
5734 * This table entry is not implemented.
5735 *
5736 * Inputs
5737 * (endpoint, asoc, chunk)
5738 *
5739 * The return value is the disposition of the chunk.
5740 */
5741sctp_disposition_t sctp_sf_not_impl(const struct sctp_endpoint *ep,
5742 const struct sctp_association *asoc,
5743 const sctp_subtype_t type,
5744 void *arg,
5745 sctp_cmd_seq_t *commands)
5746{
5747 return SCTP_DISPOSITION_NOT_IMPL;
5748}
5749
5750/*
5751 * This table entry represents a bug.
5752 *
5753 * Inputs
5754 * (endpoint, asoc, chunk)
5755 *
5756 * The return value is the disposition of the chunk.
5757 */
5758sctp_disposition_t sctp_sf_bug(const struct sctp_endpoint *ep,
5759 const struct sctp_association *asoc,
5760 const sctp_subtype_t type,
5761 void *arg,
5762 sctp_cmd_seq_t *commands)
5763{
5764 return SCTP_DISPOSITION_BUG;
5765}
5766
5767/*
5768 * This table entry represents the firing of a timer in the wrong state.
5769 * Since timer deletion cannot be guaranteed a timer 'may' end up firing
5770 * when the association is in the wrong state. This event should
5771 * be ignored, so as to prevent any rearming of the timer.
5772 *
5773 * Inputs
5774 * (endpoint, asoc, chunk)
5775 *
5776 * The return value is the disposition of the chunk.
5777 */
5778sctp_disposition_t sctp_sf_timer_ignore(const struct sctp_endpoint *ep,
5779 const struct sctp_association *asoc,
5780 const sctp_subtype_t type,
5781 void *arg,
5782 sctp_cmd_seq_t *commands)
5783{
5784 SCTP_DEBUG_PRINTK("Timer %d ignored.\n", type.chunk);
5785 return SCTP_DISPOSITION_CONSUME;
5786}
5787
5788/********************************************************************
5789 * 2nd Level Abstractions
5790 ********************************************************************/
5791
5792/* Pull the SACK chunk based on the SACK header. */
5793static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk)
5794{
5795 struct sctp_sackhdr *sack;
5796 unsigned int len;
5797 __u16 num_blocks;
5798 __u16 num_dup_tsns;
5799
5800 /* Protect ourselves from reading too far into
5801 * the skb from a bogus sender.
5802 */
5803 sack = (struct sctp_sackhdr *) chunk->skb->data;
5804
5805 num_blocks = ntohs(sack->num_gap_ack_blocks);
5806 num_dup_tsns = ntohs(sack->num_dup_tsns);
5807 len = sizeof(struct sctp_sackhdr);
5808 len += (num_blocks + num_dup_tsns) * sizeof(__u32);
5809 if (len > chunk->skb->len)
5810 return NULL;
5811
5812 skb_pull(chunk->skb, len);
5813
5814 return sack;
5815}
5816
5817/* Create an ABORT packet to be sent as a response, with the specified
5818 * error causes.
5819 */
5820static struct sctp_packet *sctp_abort_pkt_new(const struct sctp_endpoint *ep,
5821 const struct sctp_association *asoc,
5822 struct sctp_chunk *chunk,
5823 const void *payload,
5824 size_t paylen)
5825{
5826 struct sctp_packet *packet;
5827 struct sctp_chunk *abort;
5828
5829 packet = sctp_ootb_pkt_new(asoc, chunk);
5830
5831 if (packet) {
5832 /* Make an ABORT.
5833 * The T bit will be set if the asoc is NULL.
5834 */
5835 abort = sctp_make_abort(asoc, chunk, paylen);
5836 if (!abort) {
5837 sctp_ootb_pkt_free(packet);
5838 return NULL;
5839 }
5840
5841 /* Reflect vtag if T-Bit is set */
5842 if (sctp_test_T_bit(abort))
5843 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
5844
5845 /* Add specified error causes, i.e., payload, to the
5846 * end of the chunk.
5847 */
5848 sctp_addto_chunk(abort, paylen, payload);
5849
5850 /* Set the skb to the belonging sock for accounting. */
5851 abort->skb->sk = ep->base.sk;
5852
5853 sctp_packet_append_chunk(packet, abort);
5854
5855 }
5856
5857 return packet;
5858}
5859
5860/* Allocate a packet for responding in the OOTB conditions. */
5861static struct sctp_packet *sctp_ootb_pkt_new(const struct sctp_association *asoc,
5862 const struct sctp_chunk *chunk)
5863{
5864 struct sctp_packet *packet;
5865 struct sctp_transport *transport;
5866 __u16 sport;
5867 __u16 dport;
5868 __u32 vtag;
5869
5870 /* Get the source and destination port from the inbound packet. */
5871 sport = ntohs(chunk->sctp_hdr->dest);
5872 dport = ntohs(chunk->sctp_hdr->source);
5873
5874 /* The V-tag is going to be the same as the inbound packet if no
5875 * association exists, otherwise, use the peer's vtag.
5876 */
5877 if (asoc) {
5878 /* Special case the INIT-ACK as there is no peer's vtag
5879 * yet.
5880 */
5881 switch(chunk->chunk_hdr->type) {
5882 case SCTP_CID_INIT_ACK:
5883 {
5884 sctp_initack_chunk_t *initack;
5885
5886 initack = (sctp_initack_chunk_t *)chunk->chunk_hdr;
5887 vtag = ntohl(initack->init_hdr.init_tag);
5888 break;
5889 }
5890 default:
5891 vtag = asoc->peer.i.init_tag;
5892 break;
5893 }
5894 } else {
5895 /* Special case the INIT and stale COOKIE_ECHO as there is no
5896 * vtag yet.
5897 */
5898 switch(chunk->chunk_hdr->type) {
5899 case SCTP_CID_INIT:
5900 {
5901 sctp_init_chunk_t *init;
5902
5903 init = (sctp_init_chunk_t *)chunk->chunk_hdr;
5904 vtag = ntohl(init->init_hdr.init_tag);
5905 break;
5906 }
5907 default:
5908 vtag = ntohl(chunk->sctp_hdr->vtag);
5909 break;
5910 }
5911 }
5912
5913 /* Make a transport for the bucket, Eliza... */
5914 transport = sctp_transport_new(sctp_source(chunk), GFP_ATOMIC);
5915 if (!transport)
5916 goto nomem;
5917
5918 /* Cache a route for the transport with the chunk's destination as
5919 * the source address.
5920 */
5921 sctp_transport_route(transport, (union sctp_addr *)&chunk->dest,
5922 sctp_sk(sctp_get_ctl_sock()));
5923
5924 packet = sctp_packet_init(&transport->packet, transport, sport, dport);
5925 packet = sctp_packet_config(packet, vtag, 0);
5926
5927 return packet;
5928
5929nomem:
5930 return NULL;
5931}
5932
5933/* Free the packet allocated earlier for responding in the OOTB condition. */
5934void sctp_ootb_pkt_free(struct sctp_packet *packet)
5935{
5936 sctp_transport_free(packet->transport);
5937}
5938
5939/* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */
5940static void sctp_send_stale_cookie_err(const struct sctp_endpoint *ep,
5941 const struct sctp_association *asoc,
5942 const struct sctp_chunk *chunk,
5943 sctp_cmd_seq_t *commands,
5944 struct sctp_chunk *err_chunk)
5945{
5946 struct sctp_packet *packet;
5947
5948 if (err_chunk) {
5949 packet = sctp_ootb_pkt_new(asoc, chunk);
5950 if (packet) {
5951 struct sctp_signed_cookie *cookie;
5952
5953 /* Override the OOTB vtag from the cookie. */
5954 cookie = chunk->subh.cookie_hdr;
5955 packet->vtag = cookie->c.peer_vtag;
5956
5957 /* Set the skb to the belonging sock for accounting. */
5958 err_chunk->skb->sk = ep->base.sk;
5959 sctp_packet_append_chunk(packet, err_chunk);
5960 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
5961 SCTP_PACKET(packet));
5962 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
5963 } else
5964 sctp_chunk_free (err_chunk);
5965 }
5966}
5967
5968
5969/* Process a data chunk */
5970static int sctp_eat_data(const struct sctp_association *asoc,
5971 struct sctp_chunk *chunk,
5972 sctp_cmd_seq_t *commands)
5973{
5974 sctp_datahdr_t *data_hdr;
5975 struct sctp_chunk *err;
5976 size_t datalen;
5977 sctp_verb_t deliver;
5978 int tmp;
5979 __u32 tsn;
5980 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
5981 struct sock *sk = asoc->base.sk;
5982 u16 ssn;
5983 u16 sid;
5984 u8 ordered = 0;
5985
5986 data_hdr = chunk->subh.data_hdr = (sctp_datahdr_t *)chunk->skb->data;
5987 skb_pull(chunk->skb, sizeof(sctp_datahdr_t));
5988
5989 tsn = ntohl(data_hdr->tsn);
5990 SCTP_DEBUG_PRINTK("eat_data: TSN 0x%x.\n", tsn);
5991
5992 /* ASSERT: Now skb->data is really the user data. */
5993
5994 /* Process ECN based congestion.
5995 *
5996 * Since the chunk structure is reused for all chunks within
5997 * a packet, we use ecn_ce_done to track if we've already
5998 * done CE processing for this packet.
5999 *
6000 * We need to do ECN processing even if we plan to discard the
6001 * chunk later.
6002 */
6003
6004 if (!chunk->ecn_ce_done) {
6005 struct sctp_af *af;
6006 chunk->ecn_ce_done = 1;
6007
6008 af = sctp_get_af_specific(
6009 ipver2af(ip_hdr(chunk->skb)->version));
6010
6011 if (af && af->is_ce(chunk->skb) && asoc->peer.ecn_capable) {
6012 /* Do real work as sideffect. */
6013 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_CE,
6014 SCTP_U32(tsn));
6015 }
6016 }
6017
6018 tmp = sctp_tsnmap_check(&asoc->peer.tsn_map, tsn);
6019 if (tmp < 0) {
6020 /* The TSN is too high--silently discard the chunk and
6021 * count on it getting retransmitted later.
6022 */
6023 return SCTP_IERROR_HIGH_TSN;
6024 } else if (tmp > 0) {
6025 /* This is a duplicate. Record it. */
6026 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_DUP, SCTP_U32(tsn));
6027 return SCTP_IERROR_DUP_TSN;
6028 }
6029
6030 /* This is a new TSN. */
6031
6032 /* Discard if there is no room in the receive window.
6033 * Actually, allow a little bit of overflow (up to a MTU).
6034 */
6035 datalen = ntohs(chunk->chunk_hdr->length);
6036 datalen -= sizeof(sctp_data_chunk_t);
6037
6038 deliver = SCTP_CMD_CHUNK_ULP;
6039
6040 /* Think about partial delivery. */
6041 if ((datalen >= asoc->rwnd) && (!asoc->ulpq.pd_mode)) {
6042
6043 /* Even if we don't accept this chunk there is
6044 * memory pressure.
6045 */
6046 sctp_add_cmd_sf(commands, SCTP_CMD_PART_DELIVER, SCTP_NULL());
6047 }
6048
6049 /* Spill over rwnd a little bit. Note: While allowed, this spill over
6050 * seems a bit troublesome in that frag_point varies based on
6051 * PMTU. In cases, such as loopback, this might be a rather
6052 * large spill over.
6053 */
6054 if ((!chunk->data_accepted) && (!asoc->rwnd || asoc->rwnd_over ||
6055 (datalen > asoc->rwnd + asoc->frag_point))) {
6056
6057 /* If this is the next TSN, consider reneging to make
6058 * room. Note: Playing nice with a confused sender. A
6059 * malicious sender can still eat up all our buffer
6060 * space and in the future we may want to detect and
6061 * do more drastic reneging.
6062 */
6063 if (sctp_tsnmap_has_gap(map) &&
6064 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
6065 SCTP_DEBUG_PRINTK("Reneging for tsn:%u\n", tsn);
6066 deliver = SCTP_CMD_RENEGE;
6067 } else {
6068 SCTP_DEBUG_PRINTK("Discard tsn: %u len: %Zd, "
6069 "rwnd: %d\n", tsn, datalen,
6070 asoc->rwnd);
6071 return SCTP_IERROR_IGNORE_TSN;
6072 }
6073 }
6074
6075 /*
6076 * Also try to renege to limit our memory usage in the event that
6077 * we are under memory pressure
6078 * If we can't renege, don't worry about it, the sk_rmem_schedule
6079 * in sctp_ulpevent_make_rcvmsg will drop the frame if we grow our
6080 * memory usage too much
6081 */
6082 if (*sk->sk_prot_creator->memory_pressure) {
6083 if (sctp_tsnmap_has_gap(map) &&
6084 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
6085 SCTP_DEBUG_PRINTK("Under Pressure! Reneging for tsn:%u\n", tsn);
6086 deliver = SCTP_CMD_RENEGE;
6087 }
6088 }
6089
6090 /*
6091 * Section 3.3.10.9 No User Data (9)
6092 *
6093 * Cause of error
6094 * ---------------
6095 * No User Data: This error cause is returned to the originator of a
6096 * DATA chunk if a received DATA chunk has no user data.
6097 */
6098 if (unlikely(0 == datalen)) {
6099 err = sctp_make_abort_no_data(asoc, chunk, tsn);
6100 if (err) {
6101 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
6102 SCTP_CHUNK(err));
6103 }
6104 /* We are going to ABORT, so we might as well stop
6105 * processing the rest of the chunks in the packet.
6106 */
6107 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
6108 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
6109 SCTP_ERROR(ECONNABORTED));
6110 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
6111 SCTP_PERR(SCTP_ERROR_NO_DATA));
6112 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
6113 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
6114 return SCTP_IERROR_NO_DATA;
6115 }
6116
6117 chunk->data_accepted = 1;
6118
6119 /* Note: Some chunks may get overcounted (if we drop) or overcounted
6120 * if we renege and the chunk arrives again.
6121 */
6122 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
6123 SCTP_INC_STATS(SCTP_MIB_INUNORDERCHUNKS);
6124 else {
6125 SCTP_INC_STATS(SCTP_MIB_INORDERCHUNKS);
6126 ordered = 1;
6127 }
6128
6129 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
6130 *
6131 * If an endpoint receive a DATA chunk with an invalid stream
6132 * identifier, it shall acknowledge the reception of the DATA chunk
6133 * following the normal procedure, immediately send an ERROR chunk
6134 * with cause set to "Invalid Stream Identifier" (See Section 3.3.10)
6135 * and discard the DATA chunk.
6136 */
6137 sid = ntohs(data_hdr->stream);
6138 if (sid >= asoc->c.sinit_max_instreams) {
6139 /* Mark tsn as received even though we drop it */
6140 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_TSN, SCTP_U32(tsn));
6141
6142 err = sctp_make_op_error(asoc, chunk, SCTP_ERROR_INV_STRM,
6143 &data_hdr->stream,
6144 sizeof(data_hdr->stream),
6145 sizeof(u16));
6146 if (err)
6147 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
6148 SCTP_CHUNK(err));
6149 return SCTP_IERROR_BAD_STREAM;
6150 }
6151
6152 /* Check to see if the SSN is possible for this TSN.
6153 * The biggest gap we can record is 4K wide. Since SSNs wrap
6154 * at an unsigned short, there is no way that an SSN can
6155 * wrap and for a valid TSN. We can simply check if the current
6156 * SSN is smaller then the next expected one. If it is, it wrapped
6157 * and is invalid.
6158 */
6159 ssn = ntohs(data_hdr->ssn);
6160 if (ordered && SSN_lt(ssn, sctp_ssn_peek(&asoc->ssnmap->in, sid))) {
6161 return SCTP_IERROR_PROTO_VIOLATION;
6162 }
6163
6164 /* Send the data up to the user. Note: Schedule the
6165 * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK
6166 * chunk needs the updated rwnd.
6167 */
6168 sctp_add_cmd_sf(commands, deliver, SCTP_CHUNK(chunk));
6169
6170 return SCTP_IERROR_NO_ERROR;
6171}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/* SCTP kernel implementation
3 * (C) Copyright IBM Corp. 2001, 2004
4 * Copyright (c) 1999-2000 Cisco, Inc.
5 * Copyright (c) 1999-2001 Motorola, Inc.
6 * Copyright (c) 2001-2002 Intel Corp.
7 * Copyright (c) 2002 Nokia Corp.
8 *
9 * This is part of the SCTP Linux Kernel Implementation.
10 *
11 * These are the state functions for the state machine.
12 *
13 * Please send any bug reports or fixes you make to the
14 * email address(es):
15 * lksctp developers <linux-sctp@vger.kernel.org>
16 *
17 * Written or modified by:
18 * La Monte H.P. Yarroll <piggy@acm.org>
19 * Karl Knutson <karl@athena.chicago.il.us>
20 * Mathew Kotowsky <kotowsky@sctp.org>
21 * Sridhar Samudrala <samudrala@us.ibm.com>
22 * Jon Grimm <jgrimm@us.ibm.com>
23 * Hui Huang <hui.huang@nokia.com>
24 * Dajiang Zhang <dajiang.zhang@nokia.com>
25 * Daisy Chang <daisyc@us.ibm.com>
26 * Ardelle Fan <ardelle.fan@intel.com>
27 * Ryan Layer <rmlayer@us.ibm.com>
28 * Kevin Gao <kevin.gao@intel.com>
29 */
30
31#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
32
33#include <linux/types.h>
34#include <linux/kernel.h>
35#include <linux/ip.h>
36#include <linux/ipv6.h>
37#include <linux/net.h>
38#include <linux/inet.h>
39#include <linux/slab.h>
40#include <net/sock.h>
41#include <net/inet_ecn.h>
42#include <linux/skbuff.h>
43#include <net/sctp/sctp.h>
44#include <net/sctp/sm.h>
45#include <net/sctp/structs.h>
46
47#define CREATE_TRACE_POINTS
48#include <trace/events/sctp.h>
49
50static struct sctp_packet *sctp_abort_pkt_new(
51 struct net *net,
52 const struct sctp_endpoint *ep,
53 const struct sctp_association *asoc,
54 struct sctp_chunk *chunk,
55 const void *payload, size_t paylen);
56static int sctp_eat_data(const struct sctp_association *asoc,
57 struct sctp_chunk *chunk,
58 struct sctp_cmd_seq *commands);
59static struct sctp_packet *sctp_ootb_pkt_new(
60 struct net *net,
61 const struct sctp_association *asoc,
62 const struct sctp_chunk *chunk);
63static void sctp_send_stale_cookie_err(struct net *net,
64 const struct sctp_endpoint *ep,
65 const struct sctp_association *asoc,
66 const struct sctp_chunk *chunk,
67 struct sctp_cmd_seq *commands,
68 struct sctp_chunk *err_chunk);
69static enum sctp_disposition sctp_sf_do_5_2_6_stale(
70 struct net *net,
71 const struct sctp_endpoint *ep,
72 const struct sctp_association *asoc,
73 const union sctp_subtype type,
74 void *arg,
75 struct sctp_cmd_seq *commands);
76static enum sctp_disposition sctp_sf_shut_8_4_5(
77 struct net *net,
78 const struct sctp_endpoint *ep,
79 const struct sctp_association *asoc,
80 const union sctp_subtype type,
81 void *arg,
82 struct sctp_cmd_seq *commands);
83static enum sctp_disposition sctp_sf_tabort_8_4_8(
84 struct net *net,
85 const struct sctp_endpoint *ep,
86 const struct sctp_association *asoc,
87 const union sctp_subtype type,
88 void *arg,
89 struct sctp_cmd_seq *commands);
90static enum sctp_disposition sctp_sf_new_encap_port(
91 struct net *net,
92 const struct sctp_endpoint *ep,
93 const struct sctp_association *asoc,
94 const union sctp_subtype type,
95 void *arg,
96 struct sctp_cmd_seq *commands);
97static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk);
98
99static enum sctp_disposition sctp_stop_t1_and_abort(
100 struct net *net,
101 struct sctp_cmd_seq *commands,
102 __be16 error, int sk_err,
103 const struct sctp_association *asoc,
104 struct sctp_transport *transport);
105
106static enum sctp_disposition sctp_sf_abort_violation(
107 struct net *net,
108 const struct sctp_endpoint *ep,
109 const struct sctp_association *asoc,
110 void *arg,
111 struct sctp_cmd_seq *commands,
112 const __u8 *payload,
113 const size_t paylen);
114
115static enum sctp_disposition sctp_sf_violation_chunklen(
116 struct net *net,
117 const struct sctp_endpoint *ep,
118 const struct sctp_association *asoc,
119 const union sctp_subtype type,
120 void *arg,
121 struct sctp_cmd_seq *commands);
122
123static enum sctp_disposition sctp_sf_violation_paramlen(
124 struct net *net,
125 const struct sctp_endpoint *ep,
126 const struct sctp_association *asoc,
127 const union sctp_subtype type,
128 void *arg, void *ext,
129 struct sctp_cmd_seq *commands);
130
131static enum sctp_disposition sctp_sf_violation_ctsn(
132 struct net *net,
133 const struct sctp_endpoint *ep,
134 const struct sctp_association *asoc,
135 const union sctp_subtype type,
136 void *arg,
137 struct sctp_cmd_seq *commands);
138
139static enum sctp_disposition sctp_sf_violation_chunk(
140 struct net *net,
141 const struct sctp_endpoint *ep,
142 const struct sctp_association *asoc,
143 const union sctp_subtype type,
144 void *arg,
145 struct sctp_cmd_seq *commands);
146
147static enum sctp_ierror sctp_sf_authenticate(
148 const struct sctp_association *asoc,
149 struct sctp_chunk *chunk);
150
151static enum sctp_disposition __sctp_sf_do_9_1_abort(
152 struct net *net,
153 const struct sctp_endpoint *ep,
154 const struct sctp_association *asoc,
155 const union sctp_subtype type,
156 void *arg,
157 struct sctp_cmd_seq *commands);
158
159static enum sctp_disposition
160__sctp_sf_do_9_2_reshutack(struct net *net, const struct sctp_endpoint *ep,
161 const struct sctp_association *asoc,
162 const union sctp_subtype type, void *arg,
163 struct sctp_cmd_seq *commands);
164
165/* Small helper function that checks if the chunk length
166 * is of the appropriate length. The 'required_length' argument
167 * is set to be the size of a specific chunk we are testing.
168 * Return Values: true = Valid length
169 * false = Invalid length
170 *
171 */
172static inline bool sctp_chunk_length_valid(struct sctp_chunk *chunk,
173 __u16 required_length)
174{
175 __u16 chunk_length = ntohs(chunk->chunk_hdr->length);
176
177 /* Previously already marked? */
178 if (unlikely(chunk->pdiscard))
179 return false;
180 if (unlikely(chunk_length < required_length))
181 return false;
182
183 return true;
184}
185
186/* Check for format error in an ABORT chunk */
187static inline bool sctp_err_chunk_valid(struct sctp_chunk *chunk)
188{
189 struct sctp_errhdr *err;
190
191 sctp_walk_errors(err, chunk->chunk_hdr);
192
193 return (void *)err == (void *)chunk->chunk_end;
194}
195
196/**********************************************************
197 * These are the state functions for handling chunk events.
198 **********************************************************/
199
200/*
201 * Process the final SHUTDOWN COMPLETE.
202 *
203 * Section: 4 (C) (diagram), 9.2
204 * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify
205 * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be
206 * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint
207 * should stop the T2-shutdown timer and remove all knowledge of the
208 * association (and thus the association enters the CLOSED state).
209 *
210 * Verification Tag: 8.5.1(C), sctpimpguide 2.41.
211 * C) Rules for packet carrying SHUTDOWN COMPLETE:
212 * ...
213 * - The receiver of a SHUTDOWN COMPLETE shall accept the packet
214 * if the Verification Tag field of the packet matches its own tag and
215 * the T bit is not set
216 * OR
217 * it is set to its peer's tag and the T bit is set in the Chunk
218 * Flags.
219 * Otherwise, the receiver MUST silently discard the packet
220 * and take no further action. An endpoint MUST ignore the
221 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
222 *
223 * Inputs
224 * (endpoint, asoc, chunk)
225 *
226 * Outputs
227 * (asoc, reply_msg, msg_up, timers, counters)
228 *
229 * The return value is the disposition of the chunk.
230 */
231enum sctp_disposition sctp_sf_do_4_C(struct net *net,
232 const struct sctp_endpoint *ep,
233 const struct sctp_association *asoc,
234 const union sctp_subtype type,
235 void *arg, struct sctp_cmd_seq *commands)
236{
237 struct sctp_chunk *chunk = arg;
238 struct sctp_ulpevent *ev;
239
240 if (!sctp_vtag_verify_either(chunk, asoc))
241 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
242
243 /* RFC 2960 6.10 Bundling
244 *
245 * An endpoint MUST NOT bundle INIT, INIT ACK or
246 * SHUTDOWN COMPLETE with any other chunks.
247 */
248 if (!chunk->singleton)
249 return sctp_sf_violation_chunk(net, ep, asoc, type, arg, commands);
250
251 /* Make sure that the SHUTDOWN_COMPLETE chunk has a valid length. */
252 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr)))
253 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
254 commands);
255
256 /* RFC 2960 10.2 SCTP-to-ULP
257 *
258 * H) SHUTDOWN COMPLETE notification
259 *
260 * When SCTP completes the shutdown procedures (section 9.2) this
261 * notification is passed to the upper layer.
262 */
263 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
264 0, 0, 0, NULL, GFP_ATOMIC);
265 if (ev)
266 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
267 SCTP_ULPEVENT(ev));
268
269 /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint
270 * will verify that it is in SHUTDOWN-ACK-SENT state, if it is
271 * not the chunk should be discarded. If the endpoint is in
272 * the SHUTDOWN-ACK-SENT state the endpoint should stop the
273 * T2-shutdown timer and remove all knowledge of the
274 * association (and thus the association enters the CLOSED
275 * state).
276 */
277 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
278 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
279
280 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
281 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
282
283 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
284 SCTP_STATE(SCTP_STATE_CLOSED));
285
286 SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS);
287 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
288
289 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
290
291 return SCTP_DISPOSITION_DELETE_TCB;
292}
293
294/*
295 * Respond to a normal INIT chunk.
296 * We are the side that is being asked for an association.
297 *
298 * Section: 5.1 Normal Establishment of an Association, B
299 * B) "Z" shall respond immediately with an INIT ACK chunk. The
300 * destination IP address of the INIT ACK MUST be set to the source
301 * IP address of the INIT to which this INIT ACK is responding. In
302 * the response, besides filling in other parameters, "Z" must set the
303 * Verification Tag field to Tag_A, and also provide its own
304 * Verification Tag (Tag_Z) in the Initiate Tag field.
305 *
306 * Verification Tag: Must be 0.
307 *
308 * Inputs
309 * (endpoint, asoc, chunk)
310 *
311 * Outputs
312 * (asoc, reply_msg, msg_up, timers, counters)
313 *
314 * The return value is the disposition of the chunk.
315 */
316enum sctp_disposition sctp_sf_do_5_1B_init(struct net *net,
317 const struct sctp_endpoint *ep,
318 const struct sctp_association *asoc,
319 const union sctp_subtype type,
320 void *arg,
321 struct sctp_cmd_seq *commands)
322{
323 struct sctp_chunk *chunk = arg, *repl, *err_chunk;
324 struct sctp_unrecognized_param *unk_param;
325 struct sctp_association *new_asoc;
326 struct sctp_packet *packet;
327 int len;
328
329 /* 6.10 Bundling
330 * An endpoint MUST NOT bundle INIT, INIT ACK or
331 * SHUTDOWN COMPLETE with any other chunks.
332 *
333 * IG Section 2.11.2
334 * Furthermore, we require that the receiver of an INIT chunk MUST
335 * enforce these rules by silently discarding an arriving packet
336 * with an INIT chunk that is bundled with other chunks.
337 */
338 if (!chunk->singleton)
339 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
340
341 /* Make sure that the INIT chunk has a valid length.
342 * Normally, this would cause an ABORT with a Protocol Violation
343 * error, but since we don't have an association, we'll
344 * just discard the packet.
345 */
346 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_init_chunk)))
347 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
348
349 /* If the packet is an OOTB packet which is temporarily on the
350 * control endpoint, respond with an ABORT.
351 */
352 if (ep == sctp_sk(net->sctp.ctl_sock)->ep) {
353 SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
354 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
355 }
356
357 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
358 * Tag.
359 */
360 if (chunk->sctp_hdr->vtag != 0)
361 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
362
363 /* If the INIT is coming toward a closing socket, we'll send back
364 * and ABORT. Essentially, this catches the race of INIT being
365 * backloged to the socket at the same time as the user issues close().
366 * Since the socket and all its associations are going away, we
367 * can treat this OOTB
368 */
369 if (sctp_sstate(ep->base.sk, CLOSING))
370 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
371
372 /* Verify the INIT chunk before processing it. */
373 err_chunk = NULL;
374 if (!sctp_verify_init(net, ep, asoc, chunk->chunk_hdr->type,
375 (struct sctp_init_chunk *)chunk->chunk_hdr, chunk,
376 &err_chunk)) {
377 /* This chunk contains fatal error. It is to be discarded.
378 * Send an ABORT, with causes if there is any.
379 */
380 if (err_chunk) {
381 packet = sctp_abort_pkt_new(net, ep, asoc, arg,
382 (__u8 *)(err_chunk->chunk_hdr) +
383 sizeof(struct sctp_chunkhdr),
384 ntohs(err_chunk->chunk_hdr->length) -
385 sizeof(struct sctp_chunkhdr));
386
387 sctp_chunk_free(err_chunk);
388
389 if (packet) {
390 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
391 SCTP_PACKET(packet));
392 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
393 return SCTP_DISPOSITION_CONSUME;
394 } else {
395 return SCTP_DISPOSITION_NOMEM;
396 }
397 } else {
398 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg,
399 commands);
400 }
401 }
402
403 /* Grab the INIT header. */
404 chunk->subh.init_hdr = (struct sctp_inithdr *)chunk->skb->data;
405
406 /* Tag the variable length parameters. */
407 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(struct sctp_inithdr));
408
409 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
410 if (!new_asoc)
411 goto nomem;
412
413 /* Update socket peer label if first association. */
414 if (security_sctp_assoc_request(new_asoc, chunk->skb)) {
415 sctp_association_free(new_asoc);
416 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
417 }
418
419 if (sctp_assoc_set_bind_addr_from_ep(new_asoc,
420 sctp_scope(sctp_source(chunk)),
421 GFP_ATOMIC) < 0)
422 goto nomem_init;
423
424 /* The call, sctp_process_init(), can fail on memory allocation. */
425 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk),
426 (struct sctp_init_chunk *)chunk->chunk_hdr,
427 GFP_ATOMIC))
428 goto nomem_init;
429
430 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
431
432 /* If there are errors need to be reported for unknown parameters,
433 * make sure to reserve enough room in the INIT ACK for them.
434 */
435 len = 0;
436 if (err_chunk)
437 len = ntohs(err_chunk->chunk_hdr->length) -
438 sizeof(struct sctp_chunkhdr);
439
440 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
441 if (!repl)
442 goto nomem_init;
443
444 /* If there are errors need to be reported for unknown parameters,
445 * include them in the outgoing INIT ACK as "Unrecognized parameter"
446 * parameter.
447 */
448 if (err_chunk) {
449 /* Get the "Unrecognized parameter" parameter(s) out of the
450 * ERROR chunk generated by sctp_verify_init(). Since the
451 * error cause code for "unknown parameter" and the
452 * "Unrecognized parameter" type is the same, we can
453 * construct the parameters in INIT ACK by copying the
454 * ERROR causes over.
455 */
456 unk_param = (struct sctp_unrecognized_param *)
457 ((__u8 *)(err_chunk->chunk_hdr) +
458 sizeof(struct sctp_chunkhdr));
459 /* Replace the cause code with the "Unrecognized parameter"
460 * parameter type.
461 */
462 sctp_addto_chunk(repl, len, unk_param);
463 sctp_chunk_free(err_chunk);
464 }
465
466 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
467
468 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
469
470 /*
471 * Note: After sending out INIT ACK with the State Cookie parameter,
472 * "Z" MUST NOT allocate any resources, nor keep any states for the
473 * new association. Otherwise, "Z" will be vulnerable to resource
474 * attacks.
475 */
476 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
477
478 return SCTP_DISPOSITION_DELETE_TCB;
479
480nomem_init:
481 sctp_association_free(new_asoc);
482nomem:
483 if (err_chunk)
484 sctp_chunk_free(err_chunk);
485 return SCTP_DISPOSITION_NOMEM;
486}
487
488/*
489 * Respond to a normal INIT ACK chunk.
490 * We are the side that is initiating the association.
491 *
492 * Section: 5.1 Normal Establishment of an Association, C
493 * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init
494 * timer and leave COOKIE-WAIT state. "A" shall then send the State
495 * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start
496 * the T1-cookie timer, and enter the COOKIE-ECHOED state.
497 *
498 * Note: The COOKIE ECHO chunk can be bundled with any pending outbound
499 * DATA chunks, but it MUST be the first chunk in the packet and
500 * until the COOKIE ACK is returned the sender MUST NOT send any
501 * other packets to the peer.
502 *
503 * Verification Tag: 3.3.3
504 * If the value of the Initiate Tag in a received INIT ACK chunk is
505 * found to be 0, the receiver MUST treat it as an error and close the
506 * association by transmitting an ABORT.
507 *
508 * Inputs
509 * (endpoint, asoc, chunk)
510 *
511 * Outputs
512 * (asoc, reply_msg, msg_up, timers, counters)
513 *
514 * The return value is the disposition of the chunk.
515 */
516enum sctp_disposition sctp_sf_do_5_1C_ack(struct net *net,
517 const struct sctp_endpoint *ep,
518 const struct sctp_association *asoc,
519 const union sctp_subtype type,
520 void *arg,
521 struct sctp_cmd_seq *commands)
522{
523 struct sctp_init_chunk *initchunk;
524 struct sctp_chunk *chunk = arg;
525 struct sctp_chunk *err_chunk;
526 struct sctp_packet *packet;
527
528 if (!sctp_vtag_verify(chunk, asoc))
529 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
530
531 /* 6.10 Bundling
532 * An endpoint MUST NOT bundle INIT, INIT ACK or
533 * SHUTDOWN COMPLETE with any other chunks.
534 */
535 if (!chunk->singleton)
536 return sctp_sf_violation_chunk(net, ep, asoc, type, arg, commands);
537
538 /* Make sure that the INIT-ACK chunk has a valid length */
539 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_initack_chunk)))
540 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
541 commands);
542 /* Grab the INIT header. */
543 chunk->subh.init_hdr = (struct sctp_inithdr *)chunk->skb->data;
544
545 /* Verify the INIT chunk before processing it. */
546 err_chunk = NULL;
547 if (!sctp_verify_init(net, ep, asoc, chunk->chunk_hdr->type,
548 (struct sctp_init_chunk *)chunk->chunk_hdr, chunk,
549 &err_chunk)) {
550
551 enum sctp_error error = SCTP_ERROR_NO_RESOURCE;
552
553 /* This chunk contains fatal error. It is to be discarded.
554 * Send an ABORT, with causes. If there are no causes,
555 * then there wasn't enough memory. Just terminate
556 * the association.
557 */
558 if (err_chunk) {
559 packet = sctp_abort_pkt_new(net, ep, asoc, arg,
560 (__u8 *)(err_chunk->chunk_hdr) +
561 sizeof(struct sctp_chunkhdr),
562 ntohs(err_chunk->chunk_hdr->length) -
563 sizeof(struct sctp_chunkhdr));
564
565 sctp_chunk_free(err_chunk);
566
567 if (packet) {
568 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
569 SCTP_PACKET(packet));
570 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
571 error = SCTP_ERROR_INV_PARAM;
572 }
573 }
574
575 /* SCTP-AUTH, Section 6.3:
576 * It should be noted that if the receiver wants to tear
577 * down an association in an authenticated way only, the
578 * handling of malformed packets should not result in
579 * tearing down the association.
580 *
581 * This means that if we only want to abort associations
582 * in an authenticated way (i.e AUTH+ABORT), then we
583 * can't destroy this association just because the packet
584 * was malformed.
585 */
586 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
587 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
588
589 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
590 return sctp_stop_t1_and_abort(net, commands, error, ECONNREFUSED,
591 asoc, chunk->transport);
592 }
593
594 /* Tag the variable length parameters. Note that we never
595 * convert the parameters in an INIT chunk.
596 */
597 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(struct sctp_inithdr));
598
599 initchunk = (struct sctp_init_chunk *)chunk->chunk_hdr;
600
601 sctp_add_cmd_sf(commands, SCTP_CMD_PEER_INIT,
602 SCTP_PEER_INIT(initchunk));
603
604 /* Reset init error count upon receipt of INIT-ACK. */
605 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
606
607 /* 5.1 C) "A" shall stop the T1-init timer and leave
608 * COOKIE-WAIT state. "A" shall then ... start the T1-cookie
609 * timer, and enter the COOKIE-ECHOED state.
610 */
611 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
612 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
613 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
614 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
615 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
616 SCTP_STATE(SCTP_STATE_COOKIE_ECHOED));
617
618 /* SCTP-AUTH: generate the association shared keys so that
619 * we can potentially sign the COOKIE-ECHO.
620 */
621 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_SHKEY, SCTP_NULL());
622
623 /* 5.1 C) "A" shall then send the State Cookie received in the
624 * INIT ACK chunk in a COOKIE ECHO chunk, ...
625 */
626 /* If there is any errors to report, send the ERROR chunk generated
627 * for unknown parameters as well.
628 */
629 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_COOKIE_ECHO,
630 SCTP_CHUNK(err_chunk));
631
632 return SCTP_DISPOSITION_CONSUME;
633}
634
635static bool sctp_auth_chunk_verify(struct net *net, struct sctp_chunk *chunk,
636 const struct sctp_association *asoc)
637{
638 struct sctp_chunk auth;
639
640 if (!chunk->auth_chunk)
641 return true;
642
643 /* SCTP-AUTH: auth_chunk pointer is only set when the cookie-echo
644 * is supposed to be authenticated and we have to do delayed
645 * authentication. We've just recreated the association using
646 * the information in the cookie and now it's much easier to
647 * do the authentication.
648 */
649
650 /* Make sure that we and the peer are AUTH capable */
651 if (!net->sctp.auth_enable || !asoc->peer.auth_capable)
652 return false;
653
654 /* set-up our fake chunk so that we can process it */
655 auth.skb = chunk->auth_chunk;
656 auth.asoc = chunk->asoc;
657 auth.sctp_hdr = chunk->sctp_hdr;
658 auth.chunk_hdr = (struct sctp_chunkhdr *)
659 skb_push(chunk->auth_chunk,
660 sizeof(struct sctp_chunkhdr));
661 skb_pull(chunk->auth_chunk, sizeof(struct sctp_chunkhdr));
662 auth.transport = chunk->transport;
663
664 return sctp_sf_authenticate(asoc, &auth) == SCTP_IERROR_NO_ERROR;
665}
666
667/*
668 * Respond to a normal COOKIE ECHO chunk.
669 * We are the side that is being asked for an association.
670 *
671 * Section: 5.1 Normal Establishment of an Association, D
672 * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply
673 * with a COOKIE ACK chunk after building a TCB and moving to
674 * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with
675 * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK
676 * chunk MUST be the first chunk in the packet.
677 *
678 * IMPLEMENTATION NOTE: An implementation may choose to send the
679 * Communication Up notification to the SCTP user upon reception
680 * of a valid COOKIE ECHO chunk.
681 *
682 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
683 * D) Rules for packet carrying a COOKIE ECHO
684 *
685 * - When sending a COOKIE ECHO, the endpoint MUST use the value of the
686 * Initial Tag received in the INIT ACK.
687 *
688 * - The receiver of a COOKIE ECHO follows the procedures in Section 5.
689 *
690 * Inputs
691 * (endpoint, asoc, chunk)
692 *
693 * Outputs
694 * (asoc, reply_msg, msg_up, timers, counters)
695 *
696 * The return value is the disposition of the chunk.
697 */
698enum sctp_disposition sctp_sf_do_5_1D_ce(struct net *net,
699 const struct sctp_endpoint *ep,
700 const struct sctp_association *asoc,
701 const union sctp_subtype type,
702 void *arg,
703 struct sctp_cmd_seq *commands)
704{
705 struct sctp_ulpevent *ev, *ai_ev = NULL, *auth_ev = NULL;
706 struct sctp_association *new_asoc;
707 struct sctp_init_chunk *peer_init;
708 struct sctp_chunk *chunk = arg;
709 struct sctp_chunk *err_chk_p;
710 struct sctp_chunk *repl;
711 struct sock *sk;
712 int error = 0;
713
714 if (asoc && !sctp_vtag_verify(chunk, asoc))
715 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
716
717 /* If the packet is an OOTB packet which is temporarily on the
718 * control endpoint, respond with an ABORT.
719 */
720 if (ep == sctp_sk(net->sctp.ctl_sock)->ep) {
721 SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
722 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
723 }
724
725 /* Make sure that the COOKIE_ECHO chunk has a valid length.
726 * In this case, we check that we have enough for at least a
727 * chunk header. More detailed verification is done
728 * in sctp_unpack_cookie().
729 */
730 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr)))
731 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
732 commands);
733
734 /* If the endpoint is not listening or if the number of associations
735 * on the TCP-style socket exceed the max backlog, respond with an
736 * ABORT.
737 */
738 sk = ep->base.sk;
739 if (!sctp_sstate(sk, LISTENING) ||
740 (sctp_style(sk, TCP) && sk_acceptq_is_full(sk)))
741 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
742
743 /* "Decode" the chunk. We have no optional parameters so we
744 * are in good shape.
745 */
746 chunk->subh.cookie_hdr =
747 (struct sctp_signed_cookie *)chunk->skb->data;
748 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
749 sizeof(struct sctp_chunkhdr)))
750 goto nomem;
751
752 /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
753 * "Z" will reply with a COOKIE ACK chunk after building a TCB
754 * and moving to the ESTABLISHED state.
755 */
756 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
757 &err_chk_p);
758
759 /* FIXME:
760 * If the re-build failed, what is the proper error path
761 * from here?
762 *
763 * [We should abort the association. --piggy]
764 */
765 if (!new_asoc) {
766 /* FIXME: Several errors are possible. A bad cookie should
767 * be silently discarded, but think about logging it too.
768 */
769 switch (error) {
770 case -SCTP_IERROR_NOMEM:
771 goto nomem;
772
773 case -SCTP_IERROR_STALE_COOKIE:
774 sctp_send_stale_cookie_err(net, ep, asoc, chunk, commands,
775 err_chk_p);
776 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
777
778 case -SCTP_IERROR_BAD_SIG:
779 default:
780 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
781 }
782 }
783
784 if (security_sctp_assoc_request(new_asoc, chunk->head_skb ?: chunk->skb)) {
785 sctp_association_free(new_asoc);
786 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
787 }
788
789 /* Delay state machine commands until later.
790 *
791 * Re-build the bind address for the association is done in
792 * the sctp_unpack_cookie() already.
793 */
794 /* This is a brand-new association, so these are not yet side
795 * effects--it is safe to run them here.
796 */
797 peer_init = (struct sctp_init_chunk *)(chunk->subh.cookie_hdr + 1);
798 if (!sctp_process_init(new_asoc, chunk,
799 &chunk->subh.cookie_hdr->c.peer_addr,
800 peer_init, GFP_ATOMIC))
801 goto nomem_init;
802
803 /* SCTP-AUTH: Now that we've populate required fields in
804 * sctp_process_init, set up the association shared keys as
805 * necessary so that we can potentially authenticate the ACK
806 */
807 error = sctp_auth_asoc_init_active_key(new_asoc, GFP_ATOMIC);
808 if (error)
809 goto nomem_init;
810
811 if (!sctp_auth_chunk_verify(net, chunk, new_asoc)) {
812 sctp_association_free(new_asoc);
813 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
814 }
815
816 repl = sctp_make_cookie_ack(new_asoc, chunk);
817 if (!repl)
818 goto nomem_init;
819
820 /* RFC 2960 5.1 Normal Establishment of an Association
821 *
822 * D) IMPLEMENTATION NOTE: An implementation may choose to
823 * send the Communication Up notification to the SCTP user
824 * upon reception of a valid COOKIE ECHO chunk.
825 */
826 ev = sctp_ulpevent_make_assoc_change(new_asoc, 0, SCTP_COMM_UP, 0,
827 new_asoc->c.sinit_num_ostreams,
828 new_asoc->c.sinit_max_instreams,
829 NULL, GFP_ATOMIC);
830 if (!ev)
831 goto nomem_ev;
832
833 /* Sockets API Draft Section 5.3.1.6
834 * When a peer sends a Adaptation Layer Indication parameter , SCTP
835 * delivers this notification to inform the application that of the
836 * peers requested adaptation layer.
837 */
838 if (new_asoc->peer.adaptation_ind) {
839 ai_ev = sctp_ulpevent_make_adaptation_indication(new_asoc,
840 GFP_ATOMIC);
841 if (!ai_ev)
842 goto nomem_aiev;
843 }
844
845 if (!new_asoc->peer.auth_capable) {
846 auth_ev = sctp_ulpevent_make_authkey(new_asoc, 0,
847 SCTP_AUTH_NO_AUTH,
848 GFP_ATOMIC);
849 if (!auth_ev)
850 goto nomem_authev;
851 }
852
853 /* Add all the state machine commands now since we've created
854 * everything. This way we don't introduce memory corruptions
855 * during side-effect processing and correctly count established
856 * associations.
857 */
858 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
859 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
860 SCTP_STATE(SCTP_STATE_ESTABLISHED));
861 SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
862 SCTP_INC_STATS(net, SCTP_MIB_PASSIVEESTABS);
863 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
864
865 if (new_asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
866 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
867 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
868
869 /* This will send the COOKIE ACK */
870 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
871
872 /* Queue the ASSOC_CHANGE event */
873 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
874
875 /* Send up the Adaptation Layer Indication event */
876 if (ai_ev)
877 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
878 SCTP_ULPEVENT(ai_ev));
879
880 if (auth_ev)
881 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
882 SCTP_ULPEVENT(auth_ev));
883
884 return SCTP_DISPOSITION_CONSUME;
885
886nomem_authev:
887 sctp_ulpevent_free(ai_ev);
888nomem_aiev:
889 sctp_ulpevent_free(ev);
890nomem_ev:
891 sctp_chunk_free(repl);
892nomem_init:
893 sctp_association_free(new_asoc);
894nomem:
895 return SCTP_DISPOSITION_NOMEM;
896}
897
898/*
899 * Respond to a normal COOKIE ACK chunk.
900 * We are the side that is asking for an association.
901 *
902 * RFC 2960 5.1 Normal Establishment of an Association
903 *
904 * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the
905 * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie
906 * timer. It may also notify its ULP about the successful
907 * establishment of the association with a Communication Up
908 * notification (see Section 10).
909 *
910 * Verification Tag:
911 * Inputs
912 * (endpoint, asoc, chunk)
913 *
914 * Outputs
915 * (asoc, reply_msg, msg_up, timers, counters)
916 *
917 * The return value is the disposition of the chunk.
918 */
919enum sctp_disposition sctp_sf_do_5_1E_ca(struct net *net,
920 const struct sctp_endpoint *ep,
921 const struct sctp_association *asoc,
922 const union sctp_subtype type,
923 void *arg,
924 struct sctp_cmd_seq *commands)
925{
926 struct sctp_chunk *chunk = arg;
927 struct sctp_ulpevent *ev;
928
929 if (!sctp_vtag_verify(chunk, asoc))
930 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
931
932 /* Set peer label for connection. */
933 if (security_sctp_assoc_established((struct sctp_association *)asoc,
934 chunk->head_skb ?: chunk->skb))
935 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
936
937 /* Verify that the chunk length for the COOKIE-ACK is OK.
938 * If we don't do this, any bundled chunks may be junked.
939 */
940 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr)))
941 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
942 commands);
943
944 /* Reset init error count upon receipt of COOKIE-ACK,
945 * to avoid problems with the management of this
946 * counter in stale cookie situations when a transition back
947 * from the COOKIE-ECHOED state to the COOKIE-WAIT
948 * state is performed.
949 */
950 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
951
952 /* RFC 2960 5.1 Normal Establishment of an Association
953 *
954 * E) Upon reception of the COOKIE ACK, endpoint "A" will move
955 * from the COOKIE-ECHOED state to the ESTABLISHED state,
956 * stopping the T1-cookie timer.
957 */
958 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
959 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
960 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
961 SCTP_STATE(SCTP_STATE_ESTABLISHED));
962 SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
963 SCTP_INC_STATS(net, SCTP_MIB_ACTIVEESTABS);
964 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
965 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
966 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
967 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
968
969 /* It may also notify its ULP about the successful
970 * establishment of the association with a Communication Up
971 * notification (see Section 10).
972 */
973 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP,
974 0, asoc->c.sinit_num_ostreams,
975 asoc->c.sinit_max_instreams,
976 NULL, GFP_ATOMIC);
977
978 if (!ev)
979 goto nomem;
980
981 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
982
983 /* Sockets API Draft Section 5.3.1.6
984 * When a peer sends a Adaptation Layer Indication parameter , SCTP
985 * delivers this notification to inform the application that of the
986 * peers requested adaptation layer.
987 */
988 if (asoc->peer.adaptation_ind) {
989 ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
990 if (!ev)
991 goto nomem;
992
993 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
994 SCTP_ULPEVENT(ev));
995 }
996
997 if (!asoc->peer.auth_capable) {
998 ev = sctp_ulpevent_make_authkey(asoc, 0, SCTP_AUTH_NO_AUTH,
999 GFP_ATOMIC);
1000 if (!ev)
1001 goto nomem;
1002 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1003 SCTP_ULPEVENT(ev));
1004 }
1005
1006 return SCTP_DISPOSITION_CONSUME;
1007nomem:
1008 return SCTP_DISPOSITION_NOMEM;
1009}
1010
1011/* Generate and sendout a heartbeat packet. */
1012static enum sctp_disposition sctp_sf_heartbeat(
1013 const struct sctp_endpoint *ep,
1014 const struct sctp_association *asoc,
1015 const union sctp_subtype type,
1016 void *arg,
1017 struct sctp_cmd_seq *commands)
1018{
1019 struct sctp_transport *transport = (struct sctp_transport *) arg;
1020 struct sctp_chunk *reply;
1021
1022 /* Send a heartbeat to our peer. */
1023 reply = sctp_make_heartbeat(asoc, transport, 0);
1024 if (!reply)
1025 return SCTP_DISPOSITION_NOMEM;
1026
1027 /* Set rto_pending indicating that an RTT measurement
1028 * is started with this heartbeat chunk.
1029 */
1030 sctp_add_cmd_sf(commands, SCTP_CMD_RTO_PENDING,
1031 SCTP_TRANSPORT(transport));
1032
1033 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
1034 return SCTP_DISPOSITION_CONSUME;
1035}
1036
1037/* Generate a HEARTBEAT packet on the given transport. */
1038enum sctp_disposition sctp_sf_sendbeat_8_3(struct net *net,
1039 const struct sctp_endpoint *ep,
1040 const struct sctp_association *asoc,
1041 const union sctp_subtype type,
1042 void *arg,
1043 struct sctp_cmd_seq *commands)
1044{
1045 struct sctp_transport *transport = (struct sctp_transport *) arg;
1046
1047 if (asoc->overall_error_count >= asoc->max_retrans) {
1048 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
1049 SCTP_ERROR(ETIMEDOUT));
1050 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
1051 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
1052 SCTP_PERR(SCTP_ERROR_NO_ERROR));
1053 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
1054 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
1055 return SCTP_DISPOSITION_DELETE_TCB;
1056 }
1057
1058 /* Section 3.3.5.
1059 * The Sender-specific Heartbeat Info field should normally include
1060 * information about the sender's current time when this HEARTBEAT
1061 * chunk is sent and the destination transport address to which this
1062 * HEARTBEAT is sent (see Section 8.3).
1063 */
1064
1065 if (transport->param_flags & SPP_HB_ENABLE) {
1066 if (SCTP_DISPOSITION_NOMEM ==
1067 sctp_sf_heartbeat(ep, asoc, type, arg,
1068 commands))
1069 return SCTP_DISPOSITION_NOMEM;
1070
1071 /* Set transport error counter and association error counter
1072 * when sending heartbeat.
1073 */
1074 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_HB_SENT,
1075 SCTP_TRANSPORT(transport));
1076 }
1077 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_IDLE,
1078 SCTP_TRANSPORT(transport));
1079 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMER_UPDATE,
1080 SCTP_TRANSPORT(transport));
1081
1082 return SCTP_DISPOSITION_CONSUME;
1083}
1084
1085/* resend asoc strreset_chunk. */
1086enum sctp_disposition sctp_sf_send_reconf(struct net *net,
1087 const struct sctp_endpoint *ep,
1088 const struct sctp_association *asoc,
1089 const union sctp_subtype type,
1090 void *arg,
1091 struct sctp_cmd_seq *commands)
1092{
1093 struct sctp_transport *transport = arg;
1094
1095 if (asoc->overall_error_count >= asoc->max_retrans) {
1096 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
1097 SCTP_ERROR(ETIMEDOUT));
1098 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
1099 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
1100 SCTP_PERR(SCTP_ERROR_NO_ERROR));
1101 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
1102 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
1103 return SCTP_DISPOSITION_DELETE_TCB;
1104 }
1105
1106 sctp_chunk_hold(asoc->strreset_chunk);
1107 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1108 SCTP_CHUNK(asoc->strreset_chunk));
1109 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
1110
1111 return SCTP_DISPOSITION_CONSUME;
1112}
1113
1114/* send hb chunk with padding for PLPMUTD. */
1115enum sctp_disposition sctp_sf_send_probe(struct net *net,
1116 const struct sctp_endpoint *ep,
1117 const struct sctp_association *asoc,
1118 const union sctp_subtype type,
1119 void *arg,
1120 struct sctp_cmd_seq *commands)
1121{
1122 struct sctp_transport *transport = (struct sctp_transport *)arg;
1123 struct sctp_chunk *reply;
1124
1125 if (!sctp_transport_pl_enabled(transport))
1126 return SCTP_DISPOSITION_CONSUME;
1127
1128 sctp_transport_pl_send(transport);
1129 reply = sctp_make_heartbeat(asoc, transport, transport->pl.probe_size);
1130 if (!reply)
1131 return SCTP_DISPOSITION_NOMEM;
1132 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
1133 sctp_add_cmd_sf(commands, SCTP_CMD_PROBE_TIMER_UPDATE,
1134 SCTP_TRANSPORT(transport));
1135
1136 return SCTP_DISPOSITION_CONSUME;
1137}
1138
1139/*
1140 * Process an heartbeat request.
1141 *
1142 * Section: 8.3 Path Heartbeat
1143 * The receiver of the HEARTBEAT should immediately respond with a
1144 * HEARTBEAT ACK that contains the Heartbeat Information field copied
1145 * from the received HEARTBEAT chunk.
1146 *
1147 * Verification Tag: 8.5 Verification Tag [Normal verification]
1148 * When receiving an SCTP packet, the endpoint MUST ensure that the
1149 * value in the Verification Tag field of the received SCTP packet
1150 * matches its own Tag. If the received Verification Tag value does not
1151 * match the receiver's own tag value, the receiver shall silently
1152 * discard the packet and shall not process it any further except for
1153 * those cases listed in Section 8.5.1 below.
1154 *
1155 * Inputs
1156 * (endpoint, asoc, chunk)
1157 *
1158 * Outputs
1159 * (asoc, reply_msg, msg_up, timers, counters)
1160 *
1161 * The return value is the disposition of the chunk.
1162 */
1163enum sctp_disposition sctp_sf_beat_8_3(struct net *net,
1164 const struct sctp_endpoint *ep,
1165 const struct sctp_association *asoc,
1166 const union sctp_subtype type,
1167 void *arg, struct sctp_cmd_seq *commands)
1168{
1169 struct sctp_paramhdr *param_hdr;
1170 struct sctp_chunk *chunk = arg;
1171 struct sctp_chunk *reply;
1172 size_t paylen = 0;
1173
1174 if (!sctp_vtag_verify(chunk, asoc))
1175 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1176
1177 /* Make sure that the HEARTBEAT chunk has a valid length. */
1178 if (!sctp_chunk_length_valid(chunk,
1179 sizeof(struct sctp_heartbeat_chunk)))
1180 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1181 commands);
1182
1183 /* 8.3 The receiver of the HEARTBEAT should immediately
1184 * respond with a HEARTBEAT ACK that contains the Heartbeat
1185 * Information field copied from the received HEARTBEAT chunk.
1186 */
1187 chunk->subh.hb_hdr = (struct sctp_heartbeathdr *)chunk->skb->data;
1188 param_hdr = (struct sctp_paramhdr *)chunk->subh.hb_hdr;
1189 paylen = ntohs(chunk->chunk_hdr->length) - sizeof(struct sctp_chunkhdr);
1190
1191 if (ntohs(param_hdr->length) > paylen)
1192 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
1193 param_hdr, commands);
1194
1195 if (!pskb_pull(chunk->skb, paylen))
1196 goto nomem;
1197
1198 reply = sctp_make_heartbeat_ack(asoc, chunk, param_hdr, paylen);
1199 if (!reply)
1200 goto nomem;
1201
1202 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
1203 return SCTP_DISPOSITION_CONSUME;
1204
1205nomem:
1206 return SCTP_DISPOSITION_NOMEM;
1207}
1208
1209/*
1210 * Process the returning HEARTBEAT ACK.
1211 *
1212 * Section: 8.3 Path Heartbeat
1213 * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT
1214 * should clear the error counter of the destination transport
1215 * address to which the HEARTBEAT was sent, and mark the destination
1216 * transport address as active if it is not so marked. The endpoint may
1217 * optionally report to the upper layer when an inactive destination
1218 * address is marked as active due to the reception of the latest
1219 * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also
1220 * clear the association overall error count as well (as defined
1221 * in section 8.1).
1222 *
1223 * The receiver of the HEARTBEAT ACK should also perform an RTT
1224 * measurement for that destination transport address using the time
1225 * value carried in the HEARTBEAT ACK chunk.
1226 *
1227 * Verification Tag: 8.5 Verification Tag [Normal verification]
1228 *
1229 * Inputs
1230 * (endpoint, asoc, chunk)
1231 *
1232 * Outputs
1233 * (asoc, reply_msg, msg_up, timers, counters)
1234 *
1235 * The return value is the disposition of the chunk.
1236 */
1237enum sctp_disposition sctp_sf_backbeat_8_3(struct net *net,
1238 const struct sctp_endpoint *ep,
1239 const struct sctp_association *asoc,
1240 const union sctp_subtype type,
1241 void *arg,
1242 struct sctp_cmd_seq *commands)
1243{
1244 struct sctp_sender_hb_info *hbinfo;
1245 struct sctp_chunk *chunk = arg;
1246 struct sctp_transport *link;
1247 unsigned long max_interval;
1248 union sctp_addr from_addr;
1249
1250 if (!sctp_vtag_verify(chunk, asoc))
1251 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1252
1253 /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */
1254 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr) +
1255 sizeof(*hbinfo)))
1256 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1257 commands);
1258
1259 hbinfo = (struct sctp_sender_hb_info *)chunk->skb->data;
1260 /* Make sure that the length of the parameter is what we expect */
1261 if (ntohs(hbinfo->param_hdr.length) != sizeof(*hbinfo))
1262 return SCTP_DISPOSITION_DISCARD;
1263
1264 from_addr = hbinfo->daddr;
1265 link = sctp_assoc_lookup_paddr(asoc, &from_addr);
1266
1267 /* This should never happen, but lets log it if so. */
1268 if (unlikely(!link)) {
1269 if (from_addr.sa.sa_family == AF_INET6) {
1270 net_warn_ratelimited("%s association %p could not find address %pI6\n",
1271 __func__,
1272 asoc,
1273 &from_addr.v6.sin6_addr);
1274 } else {
1275 net_warn_ratelimited("%s association %p could not find address %pI4\n",
1276 __func__,
1277 asoc,
1278 &from_addr.v4.sin_addr.s_addr);
1279 }
1280 return SCTP_DISPOSITION_DISCARD;
1281 }
1282
1283 /* Validate the 64-bit random nonce. */
1284 if (hbinfo->hb_nonce != link->hb_nonce)
1285 return SCTP_DISPOSITION_DISCARD;
1286
1287 if (hbinfo->probe_size) {
1288 if (hbinfo->probe_size != link->pl.probe_size ||
1289 !sctp_transport_pl_enabled(link))
1290 return SCTP_DISPOSITION_DISCARD;
1291
1292 if (sctp_transport_pl_recv(link))
1293 return SCTP_DISPOSITION_CONSUME;
1294
1295 return sctp_sf_send_probe(net, ep, asoc, type, link, commands);
1296 }
1297
1298 max_interval = link->hbinterval + link->rto;
1299
1300 /* Check if the timestamp looks valid. */
1301 if (time_after(hbinfo->sent_at, jiffies) ||
1302 time_after(jiffies, hbinfo->sent_at + max_interval)) {
1303 pr_debug("%s: HEARTBEAT ACK with invalid timestamp received "
1304 "for transport:%p\n", __func__, link);
1305
1306 return SCTP_DISPOSITION_DISCARD;
1307 }
1308
1309 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of
1310 * the HEARTBEAT should clear the error counter of the
1311 * destination transport address to which the HEARTBEAT was
1312 * sent and mark the destination transport address as active if
1313 * it is not so marked.
1314 */
1315 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_ON, SCTP_TRANSPORT(link));
1316
1317 return SCTP_DISPOSITION_CONSUME;
1318}
1319
1320/* Helper function to send out an abort for the restart
1321 * condition.
1322 */
1323static int sctp_sf_send_restart_abort(struct net *net, union sctp_addr *ssa,
1324 struct sctp_chunk *init,
1325 struct sctp_cmd_seq *commands)
1326{
1327 struct sctp_af *af = sctp_get_af_specific(ssa->v4.sin_family);
1328 union sctp_addr_param *addrparm;
1329 struct sctp_errhdr *errhdr;
1330 char buffer[sizeof(*errhdr) + sizeof(*addrparm)];
1331 struct sctp_endpoint *ep;
1332 struct sctp_packet *pkt;
1333 int len;
1334
1335 /* Build the error on the stack. We are way to malloc crazy
1336 * throughout the code today.
1337 */
1338 errhdr = (struct sctp_errhdr *)buffer;
1339 addrparm = (union sctp_addr_param *)(errhdr + 1);
1340
1341 /* Copy into a parm format. */
1342 len = af->to_addr_param(ssa, addrparm);
1343 len += sizeof(*errhdr);
1344
1345 errhdr->cause = SCTP_ERROR_RESTART;
1346 errhdr->length = htons(len);
1347
1348 /* Assign to the control socket. */
1349 ep = sctp_sk(net->sctp.ctl_sock)->ep;
1350
1351 /* Association is NULL since this may be a restart attack and we
1352 * want to send back the attacker's vtag.
1353 */
1354 pkt = sctp_abort_pkt_new(net, ep, NULL, init, errhdr, len);
1355
1356 if (!pkt)
1357 goto out;
1358 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, SCTP_PACKET(pkt));
1359
1360 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
1361
1362 /* Discard the rest of the inbound packet. */
1363 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
1364
1365out:
1366 /* Even if there is no memory, treat as a failure so
1367 * the packet will get dropped.
1368 */
1369 return 0;
1370}
1371
1372static bool list_has_sctp_addr(const struct list_head *list,
1373 union sctp_addr *ipaddr)
1374{
1375 struct sctp_transport *addr;
1376
1377 list_for_each_entry(addr, list, transports) {
1378 if (sctp_cmp_addr_exact(ipaddr, &addr->ipaddr))
1379 return true;
1380 }
1381
1382 return false;
1383}
1384/* A restart is occurring, check to make sure no new addresses
1385 * are being added as we may be under a takeover attack.
1386 */
1387static int sctp_sf_check_restart_addrs(const struct sctp_association *new_asoc,
1388 const struct sctp_association *asoc,
1389 struct sctp_chunk *init,
1390 struct sctp_cmd_seq *commands)
1391{
1392 struct net *net = new_asoc->base.net;
1393 struct sctp_transport *new_addr;
1394 int ret = 1;
1395
1396 /* Implementor's Guide - Section 5.2.2
1397 * ...
1398 * Before responding the endpoint MUST check to see if the
1399 * unexpected INIT adds new addresses to the association. If new
1400 * addresses are added to the association, the endpoint MUST respond
1401 * with an ABORT..
1402 */
1403
1404 /* Search through all current addresses and make sure
1405 * we aren't adding any new ones.
1406 */
1407 list_for_each_entry(new_addr, &new_asoc->peer.transport_addr_list,
1408 transports) {
1409 if (!list_has_sctp_addr(&asoc->peer.transport_addr_list,
1410 &new_addr->ipaddr)) {
1411 sctp_sf_send_restart_abort(net, &new_addr->ipaddr, init,
1412 commands);
1413 ret = 0;
1414 break;
1415 }
1416 }
1417
1418 /* Return success if all addresses were found. */
1419 return ret;
1420}
1421
1422/* Populate the verification/tie tags based on overlapping INIT
1423 * scenario.
1424 *
1425 * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state.
1426 */
1427static void sctp_tietags_populate(struct sctp_association *new_asoc,
1428 const struct sctp_association *asoc)
1429{
1430 switch (asoc->state) {
1431
1432 /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */
1433
1434 case SCTP_STATE_COOKIE_WAIT:
1435 new_asoc->c.my_vtag = asoc->c.my_vtag;
1436 new_asoc->c.my_ttag = asoc->c.my_vtag;
1437 new_asoc->c.peer_ttag = 0;
1438 break;
1439
1440 case SCTP_STATE_COOKIE_ECHOED:
1441 new_asoc->c.my_vtag = asoc->c.my_vtag;
1442 new_asoc->c.my_ttag = asoc->c.my_vtag;
1443 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1444 break;
1445
1446 /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED,
1447 * COOKIE-WAIT and SHUTDOWN-ACK-SENT
1448 */
1449 default:
1450 new_asoc->c.my_ttag = asoc->c.my_vtag;
1451 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1452 break;
1453 }
1454
1455 /* Other parameters for the endpoint SHOULD be copied from the
1456 * existing parameters of the association (e.g. number of
1457 * outbound streams) into the INIT ACK and cookie.
1458 */
1459 new_asoc->rwnd = asoc->rwnd;
1460 new_asoc->c.sinit_num_ostreams = asoc->c.sinit_num_ostreams;
1461 new_asoc->c.sinit_max_instreams = asoc->c.sinit_max_instreams;
1462 new_asoc->c.initial_tsn = asoc->c.initial_tsn;
1463}
1464
1465/*
1466 * Compare vtag/tietag values to determine unexpected COOKIE-ECHO
1467 * handling action.
1468 *
1469 * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists.
1470 *
1471 * Returns value representing action to be taken. These action values
1472 * correspond to Action/Description values in RFC 2960, Table 2.
1473 */
1474static char sctp_tietags_compare(struct sctp_association *new_asoc,
1475 const struct sctp_association *asoc)
1476{
1477 /* In this case, the peer may have restarted. */
1478 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1479 (asoc->c.peer_vtag != new_asoc->c.peer_vtag) &&
1480 (asoc->c.my_vtag == new_asoc->c.my_ttag) &&
1481 (asoc->c.peer_vtag == new_asoc->c.peer_ttag))
1482 return 'A';
1483
1484 /* Collision case B. */
1485 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1486 ((asoc->c.peer_vtag != new_asoc->c.peer_vtag) ||
1487 (0 == asoc->c.peer_vtag))) {
1488 return 'B';
1489 }
1490
1491 /* Collision case D. */
1492 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1493 (asoc->c.peer_vtag == new_asoc->c.peer_vtag))
1494 return 'D';
1495
1496 /* Collision case C. */
1497 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1498 (asoc->c.peer_vtag == new_asoc->c.peer_vtag) &&
1499 (0 == new_asoc->c.my_ttag) &&
1500 (0 == new_asoc->c.peer_ttag))
1501 return 'C';
1502
1503 /* No match to any of the special cases; discard this packet. */
1504 return 'E';
1505}
1506
1507/* Common helper routine for both duplicate and simultaneous INIT
1508 * chunk handling.
1509 */
1510static enum sctp_disposition sctp_sf_do_unexpected_init(
1511 struct net *net,
1512 const struct sctp_endpoint *ep,
1513 const struct sctp_association *asoc,
1514 const union sctp_subtype type,
1515 void *arg,
1516 struct sctp_cmd_seq *commands)
1517{
1518 struct sctp_chunk *chunk = arg, *repl, *err_chunk;
1519 struct sctp_unrecognized_param *unk_param;
1520 struct sctp_association *new_asoc;
1521 enum sctp_disposition retval;
1522 struct sctp_packet *packet;
1523 int len;
1524
1525 /* 6.10 Bundling
1526 * An endpoint MUST NOT bundle INIT, INIT ACK or
1527 * SHUTDOWN COMPLETE with any other chunks.
1528 *
1529 * IG Section 2.11.2
1530 * Furthermore, we require that the receiver of an INIT chunk MUST
1531 * enforce these rules by silently discarding an arriving packet
1532 * with an INIT chunk that is bundled with other chunks.
1533 */
1534 if (!chunk->singleton)
1535 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1536
1537 /* Make sure that the INIT chunk has a valid length. */
1538 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_init_chunk)))
1539 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1540
1541 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
1542 * Tag.
1543 */
1544 if (chunk->sctp_hdr->vtag != 0)
1545 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
1546
1547 if (SCTP_INPUT_CB(chunk->skb)->encap_port != chunk->transport->encap_port)
1548 return sctp_sf_new_encap_port(net, ep, asoc, type, arg, commands);
1549
1550 /* Grab the INIT header. */
1551 chunk->subh.init_hdr = (struct sctp_inithdr *)chunk->skb->data;
1552
1553 /* Tag the variable length parameters. */
1554 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(struct sctp_inithdr));
1555
1556 /* Verify the INIT chunk before processing it. */
1557 err_chunk = NULL;
1558 if (!sctp_verify_init(net, ep, asoc, chunk->chunk_hdr->type,
1559 (struct sctp_init_chunk *)chunk->chunk_hdr, chunk,
1560 &err_chunk)) {
1561 /* This chunk contains fatal error. It is to be discarded.
1562 * Send an ABORT, with causes if there is any.
1563 */
1564 if (err_chunk) {
1565 packet = sctp_abort_pkt_new(net, ep, asoc, arg,
1566 (__u8 *)(err_chunk->chunk_hdr) +
1567 sizeof(struct sctp_chunkhdr),
1568 ntohs(err_chunk->chunk_hdr->length) -
1569 sizeof(struct sctp_chunkhdr));
1570
1571 if (packet) {
1572 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
1573 SCTP_PACKET(packet));
1574 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
1575 retval = SCTP_DISPOSITION_CONSUME;
1576 } else {
1577 retval = SCTP_DISPOSITION_NOMEM;
1578 }
1579 goto cleanup;
1580 } else {
1581 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg,
1582 commands);
1583 }
1584 }
1585
1586 /*
1587 * Other parameters for the endpoint SHOULD be copied from the
1588 * existing parameters of the association (e.g. number of
1589 * outbound streams) into the INIT ACK and cookie.
1590 * FIXME: We are copying parameters from the endpoint not the
1591 * association.
1592 */
1593 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
1594 if (!new_asoc)
1595 goto nomem;
1596
1597 /* Update socket peer label if first association. */
1598 if (security_sctp_assoc_request(new_asoc, chunk->skb)) {
1599 sctp_association_free(new_asoc);
1600 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1601 }
1602
1603 if (sctp_assoc_set_bind_addr_from_ep(new_asoc,
1604 sctp_scope(sctp_source(chunk)), GFP_ATOMIC) < 0)
1605 goto nomem;
1606
1607 /* In the outbound INIT ACK the endpoint MUST copy its current
1608 * Verification Tag and Peers Verification tag into a reserved
1609 * place (local tie-tag and per tie-tag) within the state cookie.
1610 */
1611 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk),
1612 (struct sctp_init_chunk *)chunk->chunk_hdr,
1613 GFP_ATOMIC))
1614 goto nomem;
1615
1616 /* Make sure no new addresses are being added during the
1617 * restart. Do not do this check for COOKIE-WAIT state,
1618 * since there are no peer addresses to check against.
1619 * Upon return an ABORT will have been sent if needed.
1620 */
1621 if (!sctp_state(asoc, COOKIE_WAIT)) {
1622 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk,
1623 commands)) {
1624 retval = SCTP_DISPOSITION_CONSUME;
1625 goto nomem_retval;
1626 }
1627 }
1628
1629 sctp_tietags_populate(new_asoc, asoc);
1630
1631 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
1632
1633 /* If there are errors need to be reported for unknown parameters,
1634 * make sure to reserve enough room in the INIT ACK for them.
1635 */
1636 len = 0;
1637 if (err_chunk) {
1638 len = ntohs(err_chunk->chunk_hdr->length) -
1639 sizeof(struct sctp_chunkhdr);
1640 }
1641
1642 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
1643 if (!repl)
1644 goto nomem;
1645
1646 /* If there are errors need to be reported for unknown parameters,
1647 * include them in the outgoing INIT ACK as "Unrecognized parameter"
1648 * parameter.
1649 */
1650 if (err_chunk) {
1651 /* Get the "Unrecognized parameter" parameter(s) out of the
1652 * ERROR chunk generated by sctp_verify_init(). Since the
1653 * error cause code for "unknown parameter" and the
1654 * "Unrecognized parameter" type is the same, we can
1655 * construct the parameters in INIT ACK by copying the
1656 * ERROR causes over.
1657 */
1658 unk_param = (struct sctp_unrecognized_param *)
1659 ((__u8 *)(err_chunk->chunk_hdr) +
1660 sizeof(struct sctp_chunkhdr));
1661 /* Replace the cause code with the "Unrecognized parameter"
1662 * parameter type.
1663 */
1664 sctp_addto_chunk(repl, len, unk_param);
1665 }
1666
1667 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
1668 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1669
1670 /*
1671 * Note: After sending out INIT ACK with the State Cookie parameter,
1672 * "Z" MUST NOT allocate any resources for this new association.
1673 * Otherwise, "Z" will be vulnerable to resource attacks.
1674 */
1675 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
1676 retval = SCTP_DISPOSITION_CONSUME;
1677
1678 return retval;
1679
1680nomem:
1681 retval = SCTP_DISPOSITION_NOMEM;
1682nomem_retval:
1683 if (new_asoc)
1684 sctp_association_free(new_asoc);
1685cleanup:
1686 if (err_chunk)
1687 sctp_chunk_free(err_chunk);
1688 return retval;
1689}
1690
1691/*
1692 * Handle simultaneous INIT.
1693 * This means we started an INIT and then we got an INIT request from
1694 * our peer.
1695 *
1696 * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B)
1697 * This usually indicates an initialization collision, i.e., each
1698 * endpoint is attempting, at about the same time, to establish an
1699 * association with the other endpoint.
1700 *
1701 * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an
1702 * endpoint MUST respond with an INIT ACK using the same parameters it
1703 * sent in its original INIT chunk (including its Verification Tag,
1704 * unchanged). These original parameters are combined with those from the
1705 * newly received INIT chunk. The endpoint shall also generate a State
1706 * Cookie with the INIT ACK. The endpoint uses the parameters sent in its
1707 * INIT to calculate the State Cookie.
1708 *
1709 * After that, the endpoint MUST NOT change its state, the T1-init
1710 * timer shall be left running and the corresponding TCB MUST NOT be
1711 * destroyed. The normal procedures for handling State Cookies when
1712 * a TCB exists will resolve the duplicate INITs to a single association.
1713 *
1714 * For an endpoint that is in the COOKIE-ECHOED state it MUST populate
1715 * its Tie-Tags with the Tag information of itself and its peer (see
1716 * section 5.2.2 for a description of the Tie-Tags).
1717 *
1718 * Verification Tag: Not explicit, but an INIT can not have a valid
1719 * verification tag, so we skip the check.
1720 *
1721 * Inputs
1722 * (endpoint, asoc, chunk)
1723 *
1724 * Outputs
1725 * (asoc, reply_msg, msg_up, timers, counters)
1726 *
1727 * The return value is the disposition of the chunk.
1728 */
1729enum sctp_disposition sctp_sf_do_5_2_1_siminit(
1730 struct net *net,
1731 const struct sctp_endpoint *ep,
1732 const struct sctp_association *asoc,
1733 const union sctp_subtype type,
1734 void *arg,
1735 struct sctp_cmd_seq *commands)
1736{
1737 /* Call helper to do the real work for both simultaneous and
1738 * duplicate INIT chunk handling.
1739 */
1740 return sctp_sf_do_unexpected_init(net, ep, asoc, type, arg, commands);
1741}
1742
1743/*
1744 * Handle duplicated INIT messages. These are usually delayed
1745 * restransmissions.
1746 *
1747 * Section: 5.2.2 Unexpected INIT in States Other than CLOSED,
1748 * COOKIE-ECHOED and COOKIE-WAIT
1749 *
1750 * Unless otherwise stated, upon reception of an unexpected INIT for
1751 * this association, the endpoint shall generate an INIT ACK with a
1752 * State Cookie. In the outbound INIT ACK the endpoint MUST copy its
1753 * current Verification Tag and peer's Verification Tag into a reserved
1754 * place within the state cookie. We shall refer to these locations as
1755 * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet
1756 * containing this INIT ACK MUST carry a Verification Tag value equal to
1757 * the Initiation Tag found in the unexpected INIT. And the INIT ACK
1758 * MUST contain a new Initiation Tag (randomly generated see Section
1759 * 5.3.1). Other parameters for the endpoint SHOULD be copied from the
1760 * existing parameters of the association (e.g. number of outbound
1761 * streams) into the INIT ACK and cookie.
1762 *
1763 * After sending out the INIT ACK, the endpoint shall take no further
1764 * actions, i.e., the existing association, including its current state,
1765 * and the corresponding TCB MUST NOT be changed.
1766 *
1767 * Note: Only when a TCB exists and the association is not in a COOKIE-
1768 * WAIT state are the Tie-Tags populated. For a normal association INIT
1769 * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be
1770 * set to 0 (indicating that no previous TCB existed). The INIT ACK and
1771 * State Cookie are populated as specified in section 5.2.1.
1772 *
1773 * Verification Tag: Not specified, but an INIT has no way of knowing
1774 * what the verification tag could be, so we ignore it.
1775 *
1776 * Inputs
1777 * (endpoint, asoc, chunk)
1778 *
1779 * Outputs
1780 * (asoc, reply_msg, msg_up, timers, counters)
1781 *
1782 * The return value is the disposition of the chunk.
1783 */
1784enum sctp_disposition sctp_sf_do_5_2_2_dupinit(
1785 struct net *net,
1786 const struct sctp_endpoint *ep,
1787 const struct sctp_association *asoc,
1788 const union sctp_subtype type,
1789 void *arg,
1790 struct sctp_cmd_seq *commands)
1791{
1792 /* Call helper to do the real work for both simultaneous and
1793 * duplicate INIT chunk handling.
1794 */
1795 return sctp_sf_do_unexpected_init(net, ep, asoc, type, arg, commands);
1796}
1797
1798
1799/*
1800 * Unexpected INIT-ACK handler.
1801 *
1802 * Section 5.2.3
1803 * If an INIT ACK received by an endpoint in any state other than the
1804 * COOKIE-WAIT state, the endpoint should discard the INIT ACK chunk.
1805 * An unexpected INIT ACK usually indicates the processing of an old or
1806 * duplicated INIT chunk.
1807*/
1808enum sctp_disposition sctp_sf_do_5_2_3_initack(
1809 struct net *net,
1810 const struct sctp_endpoint *ep,
1811 const struct sctp_association *asoc,
1812 const union sctp_subtype type,
1813 void *arg,
1814 struct sctp_cmd_seq *commands)
1815{
1816 /* Per the above section, we'll discard the chunk if we have an
1817 * endpoint. If this is an OOTB INIT-ACK, treat it as such.
1818 */
1819 if (ep == sctp_sk(net->sctp.ctl_sock)->ep)
1820 return sctp_sf_ootb(net, ep, asoc, type, arg, commands);
1821 else
1822 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
1823}
1824
1825static int sctp_sf_do_assoc_update(struct sctp_association *asoc,
1826 struct sctp_association *new,
1827 struct sctp_cmd_seq *cmds)
1828{
1829 struct net *net = asoc->base.net;
1830 struct sctp_chunk *abort;
1831
1832 if (!sctp_assoc_update(asoc, new))
1833 return 0;
1834
1835 abort = sctp_make_abort(asoc, NULL, sizeof(struct sctp_errhdr));
1836 if (abort) {
1837 sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0);
1838 sctp_add_cmd_sf(cmds, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
1839 }
1840 sctp_add_cmd_sf(cmds, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNABORTED));
1841 sctp_add_cmd_sf(cmds, SCTP_CMD_ASSOC_FAILED,
1842 SCTP_PERR(SCTP_ERROR_RSRC_LOW));
1843 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
1844 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
1845
1846 return -ENOMEM;
1847}
1848
1849/* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A')
1850 *
1851 * Section 5.2.4
1852 * A) In this case, the peer may have restarted.
1853 */
1854static enum sctp_disposition sctp_sf_do_dupcook_a(
1855 struct net *net,
1856 const struct sctp_endpoint *ep,
1857 const struct sctp_association *asoc,
1858 struct sctp_chunk *chunk,
1859 struct sctp_cmd_seq *commands,
1860 struct sctp_association *new_asoc)
1861{
1862 struct sctp_init_chunk *peer_init;
1863 enum sctp_disposition disposition;
1864 struct sctp_ulpevent *ev;
1865 struct sctp_chunk *repl;
1866 struct sctp_chunk *err;
1867
1868 /* new_asoc is a brand-new association, so these are not yet
1869 * side effects--it is safe to run them here.
1870 */
1871 peer_init = (struct sctp_init_chunk *)(chunk->subh.cookie_hdr + 1);
1872 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), peer_init,
1873 GFP_ATOMIC))
1874 goto nomem;
1875
1876 if (sctp_auth_asoc_init_active_key(new_asoc, GFP_ATOMIC))
1877 goto nomem;
1878
1879 if (!sctp_auth_chunk_verify(net, chunk, new_asoc))
1880 return SCTP_DISPOSITION_DISCARD;
1881
1882 /* Make sure no new addresses are being added during the
1883 * restart. Though this is a pretty complicated attack
1884 * since you'd have to get inside the cookie.
1885 */
1886 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk, commands))
1887 return SCTP_DISPOSITION_CONSUME;
1888
1889 /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes
1890 * the peer has restarted (Action A), it MUST NOT setup a new
1891 * association but instead resend the SHUTDOWN ACK and send an ERROR
1892 * chunk with a "Cookie Received while Shutting Down" error cause to
1893 * its peer.
1894 */
1895 if (sctp_state(asoc, SHUTDOWN_ACK_SENT)) {
1896 disposition = __sctp_sf_do_9_2_reshutack(net, ep, asoc,
1897 SCTP_ST_CHUNK(chunk->chunk_hdr->type),
1898 chunk, commands);
1899 if (SCTP_DISPOSITION_NOMEM == disposition)
1900 goto nomem;
1901
1902 err = sctp_make_op_error(asoc, chunk,
1903 SCTP_ERROR_COOKIE_IN_SHUTDOWN,
1904 NULL, 0, 0);
1905 if (err)
1906 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1907 SCTP_CHUNK(err));
1908
1909 return SCTP_DISPOSITION_CONSUME;
1910 }
1911
1912 /* For now, stop pending T3-rtx and SACK timers, fail any unsent/unacked
1913 * data. Consider the optional choice of resending of this data.
1914 */
1915 sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
1916 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1917 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
1918 sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_OUTQUEUE, SCTP_NULL());
1919
1920 /* Stop pending T4-rto timer, teardown ASCONF queue, ASCONF-ACK queue
1921 * and ASCONF-ACK cache.
1922 */
1923 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1924 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
1925 sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_ASCONF_QUEUE, SCTP_NULL());
1926
1927 /* Update the content of current association. */
1928 if (sctp_sf_do_assoc_update((struct sctp_association *)asoc, new_asoc, commands))
1929 goto nomem;
1930
1931 repl = sctp_make_cookie_ack(asoc, chunk);
1932 if (!repl)
1933 goto nomem;
1934
1935 /* Report association restart to upper layer. */
1936 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_RESTART, 0,
1937 asoc->c.sinit_num_ostreams,
1938 asoc->c.sinit_max_instreams,
1939 NULL, GFP_ATOMIC);
1940 if (!ev)
1941 goto nomem_ev;
1942
1943 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
1944 if ((sctp_state(asoc, SHUTDOWN_PENDING) ||
1945 sctp_state(asoc, SHUTDOWN_SENT)) &&
1946 (sctp_sstate(asoc->base.sk, CLOSING) ||
1947 sock_flag(asoc->base.sk, SOCK_DEAD))) {
1948 /* If the socket has been closed by user, don't
1949 * transition to ESTABLISHED. Instead trigger SHUTDOWN
1950 * bundled with COOKIE_ACK.
1951 */
1952 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1953 return sctp_sf_do_9_2_start_shutdown(net, ep, asoc,
1954 SCTP_ST_CHUNK(0), repl,
1955 commands);
1956 } else {
1957 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1958 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1959 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1960 }
1961 return SCTP_DISPOSITION_CONSUME;
1962
1963nomem_ev:
1964 sctp_chunk_free(repl);
1965nomem:
1966 return SCTP_DISPOSITION_NOMEM;
1967}
1968
1969/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B')
1970 *
1971 * Section 5.2.4
1972 * B) In this case, both sides may be attempting to start an association
1973 * at about the same time but the peer endpoint started its INIT
1974 * after responding to the local endpoint's INIT
1975 */
1976/* This case represents an initialization collision. */
1977static enum sctp_disposition sctp_sf_do_dupcook_b(
1978 struct net *net,
1979 const struct sctp_endpoint *ep,
1980 const struct sctp_association *asoc,
1981 struct sctp_chunk *chunk,
1982 struct sctp_cmd_seq *commands,
1983 struct sctp_association *new_asoc)
1984{
1985 struct sctp_init_chunk *peer_init;
1986 struct sctp_chunk *repl;
1987
1988 /* new_asoc is a brand-new association, so these are not yet
1989 * side effects--it is safe to run them here.
1990 */
1991 peer_init = (struct sctp_init_chunk *)(chunk->subh.cookie_hdr + 1);
1992 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), peer_init,
1993 GFP_ATOMIC))
1994 goto nomem;
1995
1996 if (sctp_auth_asoc_init_active_key(new_asoc, GFP_ATOMIC))
1997 goto nomem;
1998
1999 if (!sctp_auth_chunk_verify(net, chunk, new_asoc))
2000 return SCTP_DISPOSITION_DISCARD;
2001
2002 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2003 SCTP_STATE(SCTP_STATE_ESTABLISHED));
2004 if (asoc->state < SCTP_STATE_ESTABLISHED)
2005 SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
2006 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
2007
2008 /* Update the content of current association. */
2009 if (sctp_sf_do_assoc_update((struct sctp_association *)asoc, new_asoc, commands))
2010 goto nomem;
2011
2012 repl = sctp_make_cookie_ack(asoc, chunk);
2013 if (!repl)
2014 goto nomem;
2015
2016 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
2017
2018 /* RFC 2960 5.1 Normal Establishment of an Association
2019 *
2020 * D) IMPLEMENTATION NOTE: An implementation may choose to
2021 * send the Communication Up notification to the SCTP user
2022 * upon reception of a valid COOKIE ECHO chunk.
2023 *
2024 * Sadly, this needs to be implemented as a side-effect, because
2025 * we are not guaranteed to have set the association id of the real
2026 * association and so these notifications need to be delayed until
2027 * the association id is allocated.
2028 */
2029
2030 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_CHANGE, SCTP_U8(SCTP_COMM_UP));
2031
2032 /* Sockets API Draft Section 5.3.1.6
2033 * When a peer sends a Adaptation Layer Indication parameter , SCTP
2034 * delivers this notification to inform the application that of the
2035 * peers requested adaptation layer.
2036 *
2037 * This also needs to be done as a side effect for the same reason as
2038 * above.
2039 */
2040 if (asoc->peer.adaptation_ind)
2041 sctp_add_cmd_sf(commands, SCTP_CMD_ADAPTATION_IND, SCTP_NULL());
2042
2043 if (!asoc->peer.auth_capable)
2044 sctp_add_cmd_sf(commands, SCTP_CMD_PEER_NO_AUTH, SCTP_NULL());
2045
2046 return SCTP_DISPOSITION_CONSUME;
2047
2048nomem:
2049 return SCTP_DISPOSITION_NOMEM;
2050}
2051
2052/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C')
2053 *
2054 * Section 5.2.4
2055 * C) In this case, the local endpoint's cookie has arrived late.
2056 * Before it arrived, the local endpoint sent an INIT and received an
2057 * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag
2058 * but a new tag of its own.
2059 */
2060/* This case represents an initialization collision. */
2061static enum sctp_disposition sctp_sf_do_dupcook_c(
2062 struct net *net,
2063 const struct sctp_endpoint *ep,
2064 const struct sctp_association *asoc,
2065 struct sctp_chunk *chunk,
2066 struct sctp_cmd_seq *commands,
2067 struct sctp_association *new_asoc)
2068{
2069 /* The cookie should be silently discarded.
2070 * The endpoint SHOULD NOT change states and should leave
2071 * any timers running.
2072 */
2073 return SCTP_DISPOSITION_DISCARD;
2074}
2075
2076/* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D')
2077 *
2078 * Section 5.2.4
2079 *
2080 * D) When both local and remote tags match the endpoint should always
2081 * enter the ESTABLISHED state, if it has not already done so.
2082 */
2083/* This case represents an initialization collision. */
2084static enum sctp_disposition sctp_sf_do_dupcook_d(
2085 struct net *net,
2086 const struct sctp_endpoint *ep,
2087 const struct sctp_association *asoc,
2088 struct sctp_chunk *chunk,
2089 struct sctp_cmd_seq *commands,
2090 struct sctp_association *new_asoc)
2091{
2092 struct sctp_ulpevent *ev = NULL, *ai_ev = NULL, *auth_ev = NULL;
2093 struct sctp_chunk *repl;
2094
2095 /* Clarification from Implementor's Guide:
2096 * D) When both local and remote tags match the endpoint should
2097 * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state.
2098 * It should stop any cookie timer that may be running and send
2099 * a COOKIE ACK.
2100 */
2101
2102 if (!sctp_auth_chunk_verify(net, chunk, asoc))
2103 return SCTP_DISPOSITION_DISCARD;
2104
2105 /* Don't accidentally move back into established state. */
2106 if (asoc->state < SCTP_STATE_ESTABLISHED) {
2107 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2108 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
2109 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2110 SCTP_STATE(SCTP_STATE_ESTABLISHED));
2111 SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
2112 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START,
2113 SCTP_NULL());
2114
2115 /* RFC 2960 5.1 Normal Establishment of an Association
2116 *
2117 * D) IMPLEMENTATION NOTE: An implementation may choose
2118 * to send the Communication Up notification to the
2119 * SCTP user upon reception of a valid COOKIE
2120 * ECHO chunk.
2121 */
2122 ev = sctp_ulpevent_make_assoc_change(asoc, 0,
2123 SCTP_COMM_UP, 0,
2124 asoc->c.sinit_num_ostreams,
2125 asoc->c.sinit_max_instreams,
2126 NULL, GFP_ATOMIC);
2127 if (!ev)
2128 goto nomem;
2129
2130 /* Sockets API Draft Section 5.3.1.6
2131 * When a peer sends a Adaptation Layer Indication parameter,
2132 * SCTP delivers this notification to inform the application
2133 * that of the peers requested adaptation layer.
2134 */
2135 if (asoc->peer.adaptation_ind) {
2136 ai_ev = sctp_ulpevent_make_adaptation_indication(asoc,
2137 GFP_ATOMIC);
2138 if (!ai_ev)
2139 goto nomem;
2140
2141 }
2142
2143 if (!asoc->peer.auth_capable) {
2144 auth_ev = sctp_ulpevent_make_authkey(asoc, 0,
2145 SCTP_AUTH_NO_AUTH,
2146 GFP_ATOMIC);
2147 if (!auth_ev)
2148 goto nomem;
2149 }
2150 }
2151
2152 repl = sctp_make_cookie_ack(asoc, chunk);
2153 if (!repl)
2154 goto nomem;
2155
2156 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
2157
2158 if (ev)
2159 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
2160 SCTP_ULPEVENT(ev));
2161 if (ai_ev)
2162 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
2163 SCTP_ULPEVENT(ai_ev));
2164 if (auth_ev)
2165 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
2166 SCTP_ULPEVENT(auth_ev));
2167
2168 return SCTP_DISPOSITION_CONSUME;
2169
2170nomem:
2171 if (auth_ev)
2172 sctp_ulpevent_free(auth_ev);
2173 if (ai_ev)
2174 sctp_ulpevent_free(ai_ev);
2175 if (ev)
2176 sctp_ulpevent_free(ev);
2177 return SCTP_DISPOSITION_NOMEM;
2178}
2179
2180/*
2181 * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying
2182 * chunk was retransmitted and then delayed in the network.
2183 *
2184 * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists
2185 *
2186 * Verification Tag: None. Do cookie validation.
2187 *
2188 * Inputs
2189 * (endpoint, asoc, chunk)
2190 *
2191 * Outputs
2192 * (asoc, reply_msg, msg_up, timers, counters)
2193 *
2194 * The return value is the disposition of the chunk.
2195 */
2196enum sctp_disposition sctp_sf_do_5_2_4_dupcook(
2197 struct net *net,
2198 const struct sctp_endpoint *ep,
2199 const struct sctp_association *asoc,
2200 const union sctp_subtype type,
2201 void *arg,
2202 struct sctp_cmd_seq *commands)
2203{
2204 struct sctp_association *new_asoc;
2205 struct sctp_chunk *chunk = arg;
2206 enum sctp_disposition retval;
2207 struct sctp_chunk *err_chk_p;
2208 int error = 0;
2209 char action;
2210
2211 /* Make sure that the chunk has a valid length from the protocol
2212 * perspective. In this case check to make sure we have at least
2213 * enough for the chunk header. Cookie length verification is
2214 * done later.
2215 */
2216 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr))) {
2217 if (!sctp_vtag_verify(chunk, asoc))
2218 asoc = NULL;
2219 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg, commands);
2220 }
2221
2222 /* "Decode" the chunk. We have no optional parameters so we
2223 * are in good shape.
2224 */
2225 chunk->subh.cookie_hdr = (struct sctp_signed_cookie *)chunk->skb->data;
2226 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
2227 sizeof(struct sctp_chunkhdr)))
2228 goto nomem;
2229
2230 /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
2231 * of a duplicate COOKIE ECHO match the Verification Tags of the
2232 * current association, consider the State Cookie valid even if
2233 * the lifespan is exceeded.
2234 */
2235 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
2236 &err_chk_p);
2237
2238 /* FIXME:
2239 * If the re-build failed, what is the proper error path
2240 * from here?
2241 *
2242 * [We should abort the association. --piggy]
2243 */
2244 if (!new_asoc) {
2245 /* FIXME: Several errors are possible. A bad cookie should
2246 * be silently discarded, but think about logging it too.
2247 */
2248 switch (error) {
2249 case -SCTP_IERROR_NOMEM:
2250 goto nomem;
2251
2252 case -SCTP_IERROR_STALE_COOKIE:
2253 sctp_send_stale_cookie_err(net, ep, asoc, chunk, commands,
2254 err_chk_p);
2255 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2256 case -SCTP_IERROR_BAD_SIG:
2257 default:
2258 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2259 }
2260 }
2261
2262 /* Update socket peer label if first association. */
2263 if (security_sctp_assoc_request(new_asoc, chunk->head_skb ?: chunk->skb)) {
2264 sctp_association_free(new_asoc);
2265 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2266 }
2267
2268 /* Set temp so that it won't be added into hashtable */
2269 new_asoc->temp = 1;
2270
2271 /* Compare the tie_tag in cookie with the verification tag of
2272 * current association.
2273 */
2274 action = sctp_tietags_compare(new_asoc, asoc);
2275
2276 switch (action) {
2277 case 'A': /* Association restart. */
2278 retval = sctp_sf_do_dupcook_a(net, ep, asoc, chunk, commands,
2279 new_asoc);
2280 break;
2281
2282 case 'B': /* Collision case B. */
2283 retval = sctp_sf_do_dupcook_b(net, ep, asoc, chunk, commands,
2284 new_asoc);
2285 break;
2286
2287 case 'C': /* Collision case C. */
2288 retval = sctp_sf_do_dupcook_c(net, ep, asoc, chunk, commands,
2289 new_asoc);
2290 break;
2291
2292 case 'D': /* Collision case D. */
2293 retval = sctp_sf_do_dupcook_d(net, ep, asoc, chunk, commands,
2294 new_asoc);
2295 break;
2296
2297 default: /* Discard packet for all others. */
2298 retval = sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2299 break;
2300 }
2301
2302 /* Delete the temporary new association. */
2303 sctp_add_cmd_sf(commands, SCTP_CMD_SET_ASOC, SCTP_ASOC(new_asoc));
2304 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
2305
2306 /* Restore association pointer to provide SCTP command interpreter
2307 * with a valid context in case it needs to manipulate
2308 * the queues */
2309 sctp_add_cmd_sf(commands, SCTP_CMD_SET_ASOC,
2310 SCTP_ASOC((struct sctp_association *)asoc));
2311
2312 return retval;
2313
2314nomem:
2315 return SCTP_DISPOSITION_NOMEM;
2316}
2317
2318/*
2319 * Process an ABORT. (SHUTDOWN-PENDING state)
2320 *
2321 * See sctp_sf_do_9_1_abort().
2322 */
2323enum sctp_disposition sctp_sf_shutdown_pending_abort(
2324 struct net *net,
2325 const struct sctp_endpoint *ep,
2326 const struct sctp_association *asoc,
2327 const union sctp_subtype type,
2328 void *arg,
2329 struct sctp_cmd_seq *commands)
2330{
2331 struct sctp_chunk *chunk = arg;
2332
2333 if (!sctp_vtag_verify_either(chunk, asoc))
2334 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2335
2336 /* Make sure that the ABORT chunk has a valid length.
2337 * Since this is an ABORT chunk, we have to discard it
2338 * because of the following text:
2339 * RFC 2960, Section 3.3.7
2340 * If an endpoint receives an ABORT with a format error or for an
2341 * association that doesn't exist, it MUST silently discard it.
2342 * Because the length is "invalid", we can't really discard just
2343 * as we do not know its true length. So, to be safe, discard the
2344 * packet.
2345 */
2346 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_abort_chunk)))
2347 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2348
2349 /* ADD-IP: Special case for ABORT chunks
2350 * F4) One special consideration is that ABORT Chunks arriving
2351 * destined to the IP address being deleted MUST be
2352 * ignored (see Section 5.3.1 for further details).
2353 */
2354 if (SCTP_ADDR_DEL ==
2355 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2356 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2357
2358 if (!sctp_err_chunk_valid(chunk))
2359 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2360
2361 return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands);
2362}
2363
2364/*
2365 * Process an ABORT. (SHUTDOWN-SENT state)
2366 *
2367 * See sctp_sf_do_9_1_abort().
2368 */
2369enum sctp_disposition sctp_sf_shutdown_sent_abort(
2370 struct net *net,
2371 const struct sctp_endpoint *ep,
2372 const struct sctp_association *asoc,
2373 const union sctp_subtype type,
2374 void *arg,
2375 struct sctp_cmd_seq *commands)
2376{
2377 struct sctp_chunk *chunk = arg;
2378
2379 if (!sctp_vtag_verify_either(chunk, asoc))
2380 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2381
2382 /* Make sure that the ABORT chunk has a valid length.
2383 * Since this is an ABORT chunk, we have to discard it
2384 * because of the following text:
2385 * RFC 2960, Section 3.3.7
2386 * If an endpoint receives an ABORT with a format error or for an
2387 * association that doesn't exist, it MUST silently discard it.
2388 * Because the length is "invalid", we can't really discard just
2389 * as we do not know its true length. So, to be safe, discard the
2390 * packet.
2391 */
2392 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_abort_chunk)))
2393 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2394
2395 /* ADD-IP: Special case for ABORT chunks
2396 * F4) One special consideration is that ABORT Chunks arriving
2397 * destined to the IP address being deleted MUST be
2398 * ignored (see Section 5.3.1 for further details).
2399 */
2400 if (SCTP_ADDR_DEL ==
2401 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2402 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2403
2404 if (!sctp_err_chunk_valid(chunk))
2405 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2406
2407 /* Stop the T2-shutdown timer. */
2408 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2409 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2410
2411 /* Stop the T5-shutdown guard timer. */
2412 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2413 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
2414
2415 return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands);
2416}
2417
2418/*
2419 * Process an ABORT. (SHUTDOWN-ACK-SENT state)
2420 *
2421 * See sctp_sf_do_9_1_abort().
2422 */
2423enum sctp_disposition sctp_sf_shutdown_ack_sent_abort(
2424 struct net *net,
2425 const struct sctp_endpoint *ep,
2426 const struct sctp_association *asoc,
2427 const union sctp_subtype type,
2428 void *arg,
2429 struct sctp_cmd_seq *commands)
2430{
2431 /* The same T2 timer, so we should be able to use
2432 * common function with the SHUTDOWN-SENT state.
2433 */
2434 return sctp_sf_shutdown_sent_abort(net, ep, asoc, type, arg, commands);
2435}
2436
2437/*
2438 * Handle an Error received in COOKIE_ECHOED state.
2439 *
2440 * Only handle the error type of stale COOKIE Error, the other errors will
2441 * be ignored.
2442 *
2443 * Inputs
2444 * (endpoint, asoc, chunk)
2445 *
2446 * Outputs
2447 * (asoc, reply_msg, msg_up, timers, counters)
2448 *
2449 * The return value is the disposition of the chunk.
2450 */
2451enum sctp_disposition sctp_sf_cookie_echoed_err(
2452 struct net *net,
2453 const struct sctp_endpoint *ep,
2454 const struct sctp_association *asoc,
2455 const union sctp_subtype type,
2456 void *arg,
2457 struct sctp_cmd_seq *commands)
2458{
2459 struct sctp_chunk *chunk = arg;
2460 struct sctp_errhdr *err;
2461
2462 if (!sctp_vtag_verify(chunk, asoc))
2463 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2464
2465 /* Make sure that the ERROR chunk has a valid length.
2466 * The parameter walking depends on this as well.
2467 */
2468 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_operr_chunk)))
2469 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2470 commands);
2471
2472 /* Process the error here */
2473 /* FUTURE FIXME: When PR-SCTP related and other optional
2474 * parms are emitted, this will have to change to handle multiple
2475 * errors.
2476 */
2477 sctp_walk_errors(err, chunk->chunk_hdr) {
2478 if (SCTP_ERROR_STALE_COOKIE == err->cause)
2479 return sctp_sf_do_5_2_6_stale(net, ep, asoc, type,
2480 arg, commands);
2481 }
2482
2483 /* It is possible to have malformed error causes, and that
2484 * will cause us to end the walk early. However, since
2485 * we are discarding the packet, there should be no adverse
2486 * affects.
2487 */
2488 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2489}
2490
2491/*
2492 * Handle a Stale COOKIE Error
2493 *
2494 * Section: 5.2.6 Handle Stale COOKIE Error
2495 * If the association is in the COOKIE-ECHOED state, the endpoint may elect
2496 * one of the following three alternatives.
2497 * ...
2498 * 3) Send a new INIT chunk to the endpoint, adding a Cookie
2499 * Preservative parameter requesting an extension to the lifetime of
2500 * the State Cookie. When calculating the time extension, an
2501 * implementation SHOULD use the RTT information measured based on the
2502 * previous COOKIE ECHO / ERROR exchange, and should add no more
2503 * than 1 second beyond the measured RTT, due to long State Cookie
2504 * lifetimes making the endpoint more subject to a replay attack.
2505 *
2506 * Verification Tag: Not explicit, but safe to ignore.
2507 *
2508 * Inputs
2509 * (endpoint, asoc, chunk)
2510 *
2511 * Outputs
2512 * (asoc, reply_msg, msg_up, timers, counters)
2513 *
2514 * The return value is the disposition of the chunk.
2515 */
2516static enum sctp_disposition sctp_sf_do_5_2_6_stale(
2517 struct net *net,
2518 const struct sctp_endpoint *ep,
2519 const struct sctp_association *asoc,
2520 const union sctp_subtype type,
2521 void *arg,
2522 struct sctp_cmd_seq *commands)
2523{
2524 int attempts = asoc->init_err_counter + 1;
2525 struct sctp_chunk *chunk = arg, *reply;
2526 struct sctp_cookie_preserve_param bht;
2527 struct sctp_bind_addr *bp;
2528 struct sctp_errhdr *err;
2529 u32 stale;
2530
2531 if (attempts > asoc->max_init_attempts) {
2532 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
2533 SCTP_ERROR(ETIMEDOUT));
2534 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
2535 SCTP_PERR(SCTP_ERROR_STALE_COOKIE));
2536 return SCTP_DISPOSITION_DELETE_TCB;
2537 }
2538
2539 err = (struct sctp_errhdr *)(chunk->skb->data);
2540
2541 /* When calculating the time extension, an implementation
2542 * SHOULD use the RTT information measured based on the
2543 * previous COOKIE ECHO / ERROR exchange, and should add no
2544 * more than 1 second beyond the measured RTT, due to long
2545 * State Cookie lifetimes making the endpoint more subject to
2546 * a replay attack.
2547 * Measure of Staleness's unit is usec. (1/1000000 sec)
2548 * Suggested Cookie Life-span Increment's unit is msec.
2549 * (1/1000 sec)
2550 * In general, if you use the suggested cookie life, the value
2551 * found in the field of measure of staleness should be doubled
2552 * to give ample time to retransmit the new cookie and thus
2553 * yield a higher probability of success on the reattempt.
2554 */
2555 stale = ntohl(*(__be32 *)((u8 *)err + sizeof(*err)));
2556 stale = (stale * 2) / 1000;
2557
2558 bht.param_hdr.type = SCTP_PARAM_COOKIE_PRESERVATIVE;
2559 bht.param_hdr.length = htons(sizeof(bht));
2560 bht.lifespan_increment = htonl(stale);
2561
2562 /* Build that new INIT chunk. */
2563 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
2564 reply = sctp_make_init(asoc, bp, GFP_ATOMIC, sizeof(bht));
2565 if (!reply)
2566 goto nomem;
2567
2568 sctp_addto_chunk(reply, sizeof(bht), &bht);
2569
2570 /* Clear peer's init_tag cached in assoc as we are sending a new INIT */
2571 sctp_add_cmd_sf(commands, SCTP_CMD_CLEAR_INIT_TAG, SCTP_NULL());
2572
2573 /* Stop pending T3-rtx and heartbeat timers */
2574 sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
2575 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
2576
2577 /* Delete non-primary peer ip addresses since we are transitioning
2578 * back to the COOKIE-WAIT state
2579 */
2580 sctp_add_cmd_sf(commands, SCTP_CMD_DEL_NON_PRIMARY, SCTP_NULL());
2581
2582 /* If we've sent any data bundled with COOKIE-ECHO we will need to
2583 * resend
2584 */
2585 sctp_add_cmd_sf(commands, SCTP_CMD_T1_RETRAN,
2586 SCTP_TRANSPORT(asoc->peer.primary_path));
2587
2588 /* Cast away the const modifier, as we want to just
2589 * rerun it through as a sideffect.
2590 */
2591 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_INC, SCTP_NULL());
2592
2593 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2594 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
2595 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2596 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
2597 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
2598 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
2599
2600 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2601
2602 return SCTP_DISPOSITION_CONSUME;
2603
2604nomem:
2605 return SCTP_DISPOSITION_NOMEM;
2606}
2607
2608/*
2609 * Process an ABORT.
2610 *
2611 * Section: 9.1
2612 * After checking the Verification Tag, the receiving endpoint shall
2613 * remove the association from its record, and shall report the
2614 * termination to its upper layer.
2615 *
2616 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
2617 * B) Rules for packet carrying ABORT:
2618 *
2619 * - The endpoint shall always fill in the Verification Tag field of the
2620 * outbound packet with the destination endpoint's tag value if it
2621 * is known.
2622 *
2623 * - If the ABORT is sent in response to an OOTB packet, the endpoint
2624 * MUST follow the procedure described in Section 8.4.
2625 *
2626 * - The receiver MUST accept the packet if the Verification Tag
2627 * matches either its own tag, OR the tag of its peer. Otherwise, the
2628 * receiver MUST silently discard the packet and take no further
2629 * action.
2630 *
2631 * Inputs
2632 * (endpoint, asoc, chunk)
2633 *
2634 * Outputs
2635 * (asoc, reply_msg, msg_up, timers, counters)
2636 *
2637 * The return value is the disposition of the chunk.
2638 */
2639enum sctp_disposition sctp_sf_do_9_1_abort(
2640 struct net *net,
2641 const struct sctp_endpoint *ep,
2642 const struct sctp_association *asoc,
2643 const union sctp_subtype type,
2644 void *arg,
2645 struct sctp_cmd_seq *commands)
2646{
2647 struct sctp_chunk *chunk = arg;
2648
2649 if (!sctp_vtag_verify_either(chunk, asoc))
2650 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2651
2652 /* Make sure that the ABORT chunk has a valid length.
2653 * Since this is an ABORT chunk, we have to discard it
2654 * because of the following text:
2655 * RFC 2960, Section 3.3.7
2656 * If an endpoint receives an ABORT with a format error or for an
2657 * association that doesn't exist, it MUST silently discard it.
2658 * Because the length is "invalid", we can't really discard just
2659 * as we do not know its true length. So, to be safe, discard the
2660 * packet.
2661 */
2662 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_abort_chunk)))
2663 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2664
2665 /* ADD-IP: Special case for ABORT chunks
2666 * F4) One special consideration is that ABORT Chunks arriving
2667 * destined to the IP address being deleted MUST be
2668 * ignored (see Section 5.3.1 for further details).
2669 */
2670 if (SCTP_ADDR_DEL ==
2671 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2672 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2673
2674 if (!sctp_err_chunk_valid(chunk))
2675 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2676
2677 return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands);
2678}
2679
2680static enum sctp_disposition __sctp_sf_do_9_1_abort(
2681 struct net *net,
2682 const struct sctp_endpoint *ep,
2683 const struct sctp_association *asoc,
2684 const union sctp_subtype type,
2685 void *arg,
2686 struct sctp_cmd_seq *commands)
2687{
2688 __be16 error = SCTP_ERROR_NO_ERROR;
2689 struct sctp_chunk *chunk = arg;
2690 unsigned int len;
2691
2692 /* See if we have an error cause code in the chunk. */
2693 len = ntohs(chunk->chunk_hdr->length);
2694 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
2695 error = ((struct sctp_errhdr *)chunk->skb->data)->cause;
2696
2697 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNRESET));
2698 /* ASSOC_FAILED will DELETE_TCB. */
2699 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, SCTP_PERR(error));
2700 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
2701 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
2702
2703 return SCTP_DISPOSITION_ABORT;
2704}
2705
2706/*
2707 * Process an ABORT. (COOKIE-WAIT state)
2708 *
2709 * See sctp_sf_do_9_1_abort() above.
2710 */
2711enum sctp_disposition sctp_sf_cookie_wait_abort(
2712 struct net *net,
2713 const struct sctp_endpoint *ep,
2714 const struct sctp_association *asoc,
2715 const union sctp_subtype type,
2716 void *arg,
2717 struct sctp_cmd_seq *commands)
2718{
2719 __be16 error = SCTP_ERROR_NO_ERROR;
2720 struct sctp_chunk *chunk = arg;
2721 unsigned int len;
2722
2723 if (!sctp_vtag_verify_either(chunk, asoc))
2724 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2725
2726 /* Make sure that the ABORT chunk has a valid length.
2727 * Since this is an ABORT chunk, we have to discard it
2728 * because of the following text:
2729 * RFC 2960, Section 3.3.7
2730 * If an endpoint receives an ABORT with a format error or for an
2731 * association that doesn't exist, it MUST silently discard it.
2732 * Because the length is "invalid", we can't really discard just
2733 * as we do not know its true length. So, to be safe, discard the
2734 * packet.
2735 */
2736 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_abort_chunk)))
2737 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2738
2739 /* See if we have an error cause code in the chunk. */
2740 len = ntohs(chunk->chunk_hdr->length);
2741 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
2742 error = ((struct sctp_errhdr *)chunk->skb->data)->cause;
2743
2744 return sctp_stop_t1_and_abort(net, commands, error, ECONNREFUSED, asoc,
2745 chunk->transport);
2746}
2747
2748/*
2749 * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state)
2750 */
2751enum sctp_disposition sctp_sf_cookie_wait_icmp_abort(
2752 struct net *net,
2753 const struct sctp_endpoint *ep,
2754 const struct sctp_association *asoc,
2755 const union sctp_subtype type,
2756 void *arg,
2757 struct sctp_cmd_seq *commands)
2758{
2759 return sctp_stop_t1_and_abort(net, commands, SCTP_ERROR_NO_ERROR,
2760 ENOPROTOOPT, asoc,
2761 (struct sctp_transport *)arg);
2762}
2763
2764/*
2765 * Process an ABORT. (COOKIE-ECHOED state)
2766 */
2767enum sctp_disposition sctp_sf_cookie_echoed_abort(
2768 struct net *net,
2769 const struct sctp_endpoint *ep,
2770 const struct sctp_association *asoc,
2771 const union sctp_subtype type,
2772 void *arg,
2773 struct sctp_cmd_seq *commands)
2774{
2775 /* There is a single T1 timer, so we should be able to use
2776 * common function with the COOKIE-WAIT state.
2777 */
2778 return sctp_sf_cookie_wait_abort(net, ep, asoc, type, arg, commands);
2779}
2780
2781/*
2782 * Stop T1 timer and abort association with "INIT failed".
2783 *
2784 * This is common code called by several sctp_sf_*_abort() functions above.
2785 */
2786static enum sctp_disposition sctp_stop_t1_and_abort(
2787 struct net *net,
2788 struct sctp_cmd_seq *commands,
2789 __be16 error, int sk_err,
2790 const struct sctp_association *asoc,
2791 struct sctp_transport *transport)
2792{
2793 pr_debug("%s: ABORT received (INIT)\n", __func__);
2794
2795 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2796 SCTP_STATE(SCTP_STATE_CLOSED));
2797 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
2798 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2799 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
2800 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(sk_err));
2801 /* CMD_INIT_FAILED will DELETE_TCB. */
2802 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
2803 SCTP_PERR(error));
2804
2805 return SCTP_DISPOSITION_ABORT;
2806}
2807
2808/*
2809 * sctp_sf_do_9_2_shut
2810 *
2811 * Section: 9.2
2812 * Upon the reception of the SHUTDOWN, the peer endpoint shall
2813 * - enter the SHUTDOWN-RECEIVED state,
2814 *
2815 * - stop accepting new data from its SCTP user
2816 *
2817 * - verify, by checking the Cumulative TSN Ack field of the chunk,
2818 * that all its outstanding DATA chunks have been received by the
2819 * SHUTDOWN sender.
2820 *
2821 * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT
2822 * send a SHUTDOWN in response to a ULP request. And should discard
2823 * subsequent SHUTDOWN chunks.
2824 *
2825 * If there are still outstanding DATA chunks left, the SHUTDOWN
2826 * receiver shall continue to follow normal data transmission
2827 * procedures defined in Section 6 until all outstanding DATA chunks
2828 * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept
2829 * new data from its SCTP user.
2830 *
2831 * Verification Tag: 8.5 Verification Tag [Normal verification]
2832 *
2833 * Inputs
2834 * (endpoint, asoc, chunk)
2835 *
2836 * Outputs
2837 * (asoc, reply_msg, msg_up, timers, counters)
2838 *
2839 * The return value is the disposition of the chunk.
2840 */
2841enum sctp_disposition sctp_sf_do_9_2_shutdown(
2842 struct net *net,
2843 const struct sctp_endpoint *ep,
2844 const struct sctp_association *asoc,
2845 const union sctp_subtype type,
2846 void *arg,
2847 struct sctp_cmd_seq *commands)
2848{
2849 enum sctp_disposition disposition;
2850 struct sctp_chunk *chunk = arg;
2851 struct sctp_shutdownhdr *sdh;
2852 struct sctp_ulpevent *ev;
2853 __u32 ctsn;
2854
2855 if (!sctp_vtag_verify(chunk, asoc))
2856 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2857
2858 /* Make sure that the SHUTDOWN chunk has a valid length. */
2859 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_shutdown_chunk)))
2860 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2861 commands);
2862
2863 /* Convert the elaborate header. */
2864 sdh = (struct sctp_shutdownhdr *)chunk->skb->data;
2865 skb_pull(chunk->skb, sizeof(*sdh));
2866 chunk->subh.shutdown_hdr = sdh;
2867 ctsn = ntohl(sdh->cum_tsn_ack);
2868
2869 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
2870 pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn,
2871 asoc->ctsn_ack_point);
2872
2873 return SCTP_DISPOSITION_DISCARD;
2874 }
2875
2876 /* If Cumulative TSN Ack beyond the max tsn currently
2877 * send, terminating the association and respond to the
2878 * sender with an ABORT.
2879 */
2880 if (!TSN_lt(ctsn, asoc->next_tsn))
2881 return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands);
2882
2883 /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT
2884 * When a peer sends a SHUTDOWN, SCTP delivers this notification to
2885 * inform the application that it should cease sending data.
2886 */
2887 ev = sctp_ulpevent_make_shutdown_event(asoc, 0, GFP_ATOMIC);
2888 if (!ev) {
2889 disposition = SCTP_DISPOSITION_NOMEM;
2890 goto out;
2891 }
2892 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
2893
2894 /* Upon the reception of the SHUTDOWN, the peer endpoint shall
2895 * - enter the SHUTDOWN-RECEIVED state,
2896 * - stop accepting new data from its SCTP user
2897 *
2898 * [This is implicit in the new state.]
2899 */
2900 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2901 SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED));
2902 disposition = SCTP_DISPOSITION_CONSUME;
2903
2904 if (sctp_outq_is_empty(&asoc->outqueue)) {
2905 disposition = sctp_sf_do_9_2_shutdown_ack(net, ep, asoc, type,
2906 arg, commands);
2907 }
2908
2909 if (SCTP_DISPOSITION_NOMEM == disposition)
2910 goto out;
2911
2912 /* - verify, by checking the Cumulative TSN Ack field of the
2913 * chunk, that all its outstanding DATA chunks have been
2914 * received by the SHUTDOWN sender.
2915 */
2916 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
2917 SCTP_BE32(chunk->subh.shutdown_hdr->cum_tsn_ack));
2918
2919out:
2920 return disposition;
2921}
2922
2923/*
2924 * sctp_sf_do_9_2_shut_ctsn
2925 *
2926 * Once an endpoint has reached the SHUTDOWN-RECEIVED state,
2927 * it MUST NOT send a SHUTDOWN in response to a ULP request.
2928 * The Cumulative TSN Ack of the received SHUTDOWN chunk
2929 * MUST be processed.
2930 */
2931enum sctp_disposition sctp_sf_do_9_2_shut_ctsn(
2932 struct net *net,
2933 const struct sctp_endpoint *ep,
2934 const struct sctp_association *asoc,
2935 const union sctp_subtype type,
2936 void *arg,
2937 struct sctp_cmd_seq *commands)
2938{
2939 struct sctp_chunk *chunk = arg;
2940 struct sctp_shutdownhdr *sdh;
2941 __u32 ctsn;
2942
2943 if (!sctp_vtag_verify(chunk, asoc))
2944 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2945
2946 /* Make sure that the SHUTDOWN chunk has a valid length. */
2947 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_shutdown_chunk)))
2948 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2949 commands);
2950
2951 sdh = (struct sctp_shutdownhdr *)chunk->skb->data;
2952 ctsn = ntohl(sdh->cum_tsn_ack);
2953
2954 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
2955 pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn,
2956 asoc->ctsn_ack_point);
2957
2958 return SCTP_DISPOSITION_DISCARD;
2959 }
2960
2961 /* If Cumulative TSN Ack beyond the max tsn currently
2962 * send, terminating the association and respond to the
2963 * sender with an ABORT.
2964 */
2965 if (!TSN_lt(ctsn, asoc->next_tsn))
2966 return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands);
2967
2968 /* verify, by checking the Cumulative TSN Ack field of the
2969 * chunk, that all its outstanding DATA chunks have been
2970 * received by the SHUTDOWN sender.
2971 */
2972 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
2973 SCTP_BE32(sdh->cum_tsn_ack));
2974
2975 return SCTP_DISPOSITION_CONSUME;
2976}
2977
2978/* RFC 2960 9.2
2979 * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk
2980 * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination
2981 * transport addresses (either in the IP addresses or in the INIT chunk)
2982 * that belong to this association, it should discard the INIT chunk and
2983 * retransmit the SHUTDOWN ACK chunk.
2984 */
2985static enum sctp_disposition
2986__sctp_sf_do_9_2_reshutack(struct net *net, const struct sctp_endpoint *ep,
2987 const struct sctp_association *asoc,
2988 const union sctp_subtype type, void *arg,
2989 struct sctp_cmd_seq *commands)
2990{
2991 struct sctp_chunk *chunk = arg;
2992 struct sctp_chunk *reply;
2993
2994 /* Make sure that the chunk has a valid length */
2995 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr)))
2996 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2997 commands);
2998
2999 /* Since we are not going to really process this INIT, there
3000 * is no point in verifying chunk boundaries. Just generate
3001 * the SHUTDOWN ACK.
3002 */
3003 reply = sctp_make_shutdown_ack(asoc, chunk);
3004 if (NULL == reply)
3005 goto nomem;
3006
3007 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
3008 * the T2-SHUTDOWN timer.
3009 */
3010 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
3011
3012 /* and restart the T2-shutdown timer. */
3013 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3014 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3015
3016 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
3017
3018 return SCTP_DISPOSITION_CONSUME;
3019nomem:
3020 return SCTP_DISPOSITION_NOMEM;
3021}
3022
3023enum sctp_disposition
3024sctp_sf_do_9_2_reshutack(struct net *net, const struct sctp_endpoint *ep,
3025 const struct sctp_association *asoc,
3026 const union sctp_subtype type, void *arg,
3027 struct sctp_cmd_seq *commands)
3028{
3029 struct sctp_chunk *chunk = arg;
3030
3031 if (!chunk->singleton)
3032 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3033
3034 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_init_chunk)))
3035 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3036
3037 if (chunk->sctp_hdr->vtag != 0)
3038 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
3039
3040 return __sctp_sf_do_9_2_reshutack(net, ep, asoc, type, arg, commands);
3041}
3042
3043/*
3044 * sctp_sf_do_ecn_cwr
3045 *
3046 * Section: Appendix A: Explicit Congestion Notification
3047 *
3048 * CWR:
3049 *
3050 * RFC 2481 details a specific bit for a sender to send in the header of
3051 * its next outbound TCP segment to indicate to its peer that it has
3052 * reduced its congestion window. This is termed the CWR bit. For
3053 * SCTP the same indication is made by including the CWR chunk.
3054 * This chunk contains one data element, i.e. the TSN number that
3055 * was sent in the ECNE chunk. This element represents the lowest
3056 * TSN number in the datagram that was originally marked with the
3057 * CE bit.
3058 *
3059 * Verification Tag: 8.5 Verification Tag [Normal verification]
3060 * Inputs
3061 * (endpoint, asoc, chunk)
3062 *
3063 * Outputs
3064 * (asoc, reply_msg, msg_up, timers, counters)
3065 *
3066 * The return value is the disposition of the chunk.
3067 */
3068enum sctp_disposition sctp_sf_do_ecn_cwr(struct net *net,
3069 const struct sctp_endpoint *ep,
3070 const struct sctp_association *asoc,
3071 const union sctp_subtype type,
3072 void *arg,
3073 struct sctp_cmd_seq *commands)
3074{
3075 struct sctp_chunk *chunk = arg;
3076 struct sctp_cwrhdr *cwr;
3077 u32 lowest_tsn;
3078
3079 if (!sctp_vtag_verify(chunk, asoc))
3080 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3081
3082 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_ecne_chunk)))
3083 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3084 commands);
3085
3086 cwr = (struct sctp_cwrhdr *)chunk->skb->data;
3087 skb_pull(chunk->skb, sizeof(*cwr));
3088
3089 lowest_tsn = ntohl(cwr->lowest_tsn);
3090
3091 /* Does this CWR ack the last sent congestion notification? */
3092 if (TSN_lte(asoc->last_ecne_tsn, lowest_tsn)) {
3093 /* Stop sending ECNE. */
3094 sctp_add_cmd_sf(commands,
3095 SCTP_CMD_ECN_CWR,
3096 SCTP_U32(lowest_tsn));
3097 }
3098 return SCTP_DISPOSITION_CONSUME;
3099}
3100
3101/*
3102 * sctp_sf_do_ecne
3103 *
3104 * Section: Appendix A: Explicit Congestion Notification
3105 *
3106 * ECN-Echo
3107 *
3108 * RFC 2481 details a specific bit for a receiver to send back in its
3109 * TCP acknowledgements to notify the sender of the Congestion
3110 * Experienced (CE) bit having arrived from the network. For SCTP this
3111 * same indication is made by including the ECNE chunk. This chunk
3112 * contains one data element, i.e. the lowest TSN associated with the IP
3113 * datagram marked with the CE bit.....
3114 *
3115 * Verification Tag: 8.5 Verification Tag [Normal verification]
3116 * Inputs
3117 * (endpoint, asoc, chunk)
3118 *
3119 * Outputs
3120 * (asoc, reply_msg, msg_up, timers, counters)
3121 *
3122 * The return value is the disposition of the chunk.
3123 */
3124enum sctp_disposition sctp_sf_do_ecne(struct net *net,
3125 const struct sctp_endpoint *ep,
3126 const struct sctp_association *asoc,
3127 const union sctp_subtype type,
3128 void *arg, struct sctp_cmd_seq *commands)
3129{
3130 struct sctp_chunk *chunk = arg;
3131 struct sctp_ecnehdr *ecne;
3132
3133 if (!sctp_vtag_verify(chunk, asoc))
3134 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3135
3136 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_ecne_chunk)))
3137 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3138 commands);
3139
3140 ecne = (struct sctp_ecnehdr *)chunk->skb->data;
3141 skb_pull(chunk->skb, sizeof(*ecne));
3142
3143 /* If this is a newer ECNE than the last CWR packet we sent out */
3144 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_ECNE,
3145 SCTP_U32(ntohl(ecne->lowest_tsn)));
3146
3147 return SCTP_DISPOSITION_CONSUME;
3148}
3149
3150/*
3151 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
3152 *
3153 * The SCTP endpoint MUST always acknowledge the reception of each valid
3154 * DATA chunk.
3155 *
3156 * The guidelines on delayed acknowledgement algorithm specified in
3157 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
3158 * acknowledgement SHOULD be generated for at least every second packet
3159 * (not every second DATA chunk) received, and SHOULD be generated within
3160 * 200 ms of the arrival of any unacknowledged DATA chunk. In some
3161 * situations it may be beneficial for an SCTP transmitter to be more
3162 * conservative than the algorithms detailed in this document allow.
3163 * However, an SCTP transmitter MUST NOT be more aggressive than the
3164 * following algorithms allow.
3165 *
3166 * A SCTP receiver MUST NOT generate more than one SACK for every
3167 * incoming packet, other than to update the offered window as the
3168 * receiving application consumes new data.
3169 *
3170 * Verification Tag: 8.5 Verification Tag [Normal verification]
3171 *
3172 * Inputs
3173 * (endpoint, asoc, chunk)
3174 *
3175 * Outputs
3176 * (asoc, reply_msg, msg_up, timers, counters)
3177 *
3178 * The return value is the disposition of the chunk.
3179 */
3180enum sctp_disposition sctp_sf_eat_data_6_2(struct net *net,
3181 const struct sctp_endpoint *ep,
3182 const struct sctp_association *asoc,
3183 const union sctp_subtype type,
3184 void *arg,
3185 struct sctp_cmd_seq *commands)
3186{
3187 union sctp_arg force = SCTP_NOFORCE();
3188 struct sctp_chunk *chunk = arg;
3189 int error;
3190
3191 if (!sctp_vtag_verify(chunk, asoc)) {
3192 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3193 SCTP_NULL());
3194 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3195 }
3196
3197 if (!sctp_chunk_length_valid(chunk, sctp_datachk_len(&asoc->stream)))
3198 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3199 commands);
3200
3201 error = sctp_eat_data(asoc, chunk, commands);
3202 switch (error) {
3203 case SCTP_IERROR_NO_ERROR:
3204 break;
3205 case SCTP_IERROR_HIGH_TSN:
3206 case SCTP_IERROR_BAD_STREAM:
3207 SCTP_INC_STATS(net, SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
3208 goto discard_noforce;
3209 case SCTP_IERROR_DUP_TSN:
3210 case SCTP_IERROR_IGNORE_TSN:
3211 SCTP_INC_STATS(net, SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
3212 goto discard_force;
3213 case SCTP_IERROR_NO_DATA:
3214 return SCTP_DISPOSITION_ABORT;
3215 case SCTP_IERROR_PROTO_VIOLATION:
3216 return sctp_sf_abort_violation(net, ep, asoc, chunk, commands,
3217 (u8 *)chunk->subh.data_hdr,
3218 sctp_datahdr_len(&asoc->stream));
3219 default:
3220 BUG();
3221 }
3222
3223 if (chunk->chunk_hdr->flags & SCTP_DATA_SACK_IMM)
3224 force = SCTP_FORCE();
3225
3226 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) {
3227 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3228 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
3229 }
3230
3231 /* If this is the last chunk in a packet, we need to count it
3232 * toward sack generation. Note that we need to SACK every
3233 * OTHER packet containing data chunks, EVEN IF WE DISCARD
3234 * THEM. We elect to NOT generate SACK's if the chunk fails
3235 * the verification tag test.
3236 *
3237 * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
3238 *
3239 * The SCTP endpoint MUST always acknowledge the reception of
3240 * each valid DATA chunk.
3241 *
3242 * The guidelines on delayed acknowledgement algorithm
3243 * specified in Section 4.2 of [RFC2581] SHOULD be followed.
3244 * Specifically, an acknowledgement SHOULD be generated for at
3245 * least every second packet (not every second DATA chunk)
3246 * received, and SHOULD be generated within 200 ms of the
3247 * arrival of any unacknowledged DATA chunk. In some
3248 * situations it may be beneficial for an SCTP transmitter to
3249 * be more conservative than the algorithms detailed in this
3250 * document allow. However, an SCTP transmitter MUST NOT be
3251 * more aggressive than the following algorithms allow.
3252 */
3253 if (chunk->end_of_packet)
3254 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force);
3255
3256 return SCTP_DISPOSITION_CONSUME;
3257
3258discard_force:
3259 /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
3260 *
3261 * When a packet arrives with duplicate DATA chunk(s) and with
3262 * no new DATA chunk(s), the endpoint MUST immediately send a
3263 * SACK with no delay. If a packet arrives with duplicate
3264 * DATA chunk(s) bundled with new DATA chunks, the endpoint
3265 * MAY immediately send a SACK. Normally receipt of duplicate
3266 * DATA chunks will occur when the original SACK chunk was lost
3267 * and the peer's RTO has expired. The duplicate TSN number(s)
3268 * SHOULD be reported in the SACK as duplicate.
3269 */
3270 /* In our case, we split the MAY SACK advice up whether or not
3271 * the last chunk is a duplicate.'
3272 */
3273 if (chunk->end_of_packet)
3274 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3275 return SCTP_DISPOSITION_DISCARD;
3276
3277discard_noforce:
3278 if (chunk->end_of_packet)
3279 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force);
3280
3281 return SCTP_DISPOSITION_DISCARD;
3282}
3283
3284/*
3285 * sctp_sf_eat_data_fast_4_4
3286 *
3287 * Section: 4 (4)
3288 * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received
3289 * DATA chunks without delay.
3290 *
3291 * Verification Tag: 8.5 Verification Tag [Normal verification]
3292 * Inputs
3293 * (endpoint, asoc, chunk)
3294 *
3295 * Outputs
3296 * (asoc, reply_msg, msg_up, timers, counters)
3297 *
3298 * The return value is the disposition of the chunk.
3299 */
3300enum sctp_disposition sctp_sf_eat_data_fast_4_4(
3301 struct net *net,
3302 const struct sctp_endpoint *ep,
3303 const struct sctp_association *asoc,
3304 const union sctp_subtype type,
3305 void *arg,
3306 struct sctp_cmd_seq *commands)
3307{
3308 struct sctp_chunk *chunk = arg;
3309 int error;
3310
3311 if (!sctp_vtag_verify(chunk, asoc)) {
3312 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3313 SCTP_NULL());
3314 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3315 }
3316
3317 if (!sctp_chunk_length_valid(chunk, sctp_datachk_len(&asoc->stream)))
3318 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3319 commands);
3320
3321 error = sctp_eat_data(asoc, chunk, commands);
3322 switch (error) {
3323 case SCTP_IERROR_NO_ERROR:
3324 case SCTP_IERROR_HIGH_TSN:
3325 case SCTP_IERROR_DUP_TSN:
3326 case SCTP_IERROR_IGNORE_TSN:
3327 case SCTP_IERROR_BAD_STREAM:
3328 break;
3329 case SCTP_IERROR_NO_DATA:
3330 return SCTP_DISPOSITION_ABORT;
3331 case SCTP_IERROR_PROTO_VIOLATION:
3332 return sctp_sf_abort_violation(net, ep, asoc, chunk, commands,
3333 (u8 *)chunk->subh.data_hdr,
3334 sctp_datahdr_len(&asoc->stream));
3335 default:
3336 BUG();
3337 }
3338
3339 /* Go a head and force a SACK, since we are shutting down. */
3340
3341 /* Implementor's Guide.
3342 *
3343 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3344 * respond to each received packet containing one or more DATA chunk(s)
3345 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3346 */
3347 if (chunk->end_of_packet) {
3348 /* We must delay the chunk creation since the cumulative
3349 * TSN has not been updated yet.
3350 */
3351 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
3352 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3353 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3354 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3355 }
3356
3357 return SCTP_DISPOSITION_CONSUME;
3358}
3359
3360/*
3361 * Section: 6.2 Processing a Received SACK
3362 * D) Any time a SACK arrives, the endpoint performs the following:
3363 *
3364 * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point,
3365 * then drop the SACK. Since Cumulative TSN Ack is monotonically
3366 * increasing, a SACK whose Cumulative TSN Ack is less than the
3367 * Cumulative TSN Ack Point indicates an out-of-order SACK.
3368 *
3369 * ii) Set rwnd equal to the newly received a_rwnd minus the number
3370 * of bytes still outstanding after processing the Cumulative TSN Ack
3371 * and the Gap Ack Blocks.
3372 *
3373 * iii) If the SACK is missing a TSN that was previously
3374 * acknowledged via a Gap Ack Block (e.g., the data receiver
3375 * reneged on the data), then mark the corresponding DATA chunk
3376 * as available for retransmit: Mark it as missing for fast
3377 * retransmit as described in Section 7.2.4 and if no retransmit
3378 * timer is running for the destination address to which the DATA
3379 * chunk was originally transmitted, then T3-rtx is started for
3380 * that destination address.
3381 *
3382 * Verification Tag: 8.5 Verification Tag [Normal verification]
3383 *
3384 * Inputs
3385 * (endpoint, asoc, chunk)
3386 *
3387 * Outputs
3388 * (asoc, reply_msg, msg_up, timers, counters)
3389 *
3390 * The return value is the disposition of the chunk.
3391 */
3392enum sctp_disposition sctp_sf_eat_sack_6_2(struct net *net,
3393 const struct sctp_endpoint *ep,
3394 const struct sctp_association *asoc,
3395 const union sctp_subtype type,
3396 void *arg,
3397 struct sctp_cmd_seq *commands)
3398{
3399 struct sctp_chunk *chunk = arg;
3400 struct sctp_sackhdr *sackh;
3401 __u32 ctsn;
3402
3403 if (!sctp_vtag_verify(chunk, asoc))
3404 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3405
3406 /* Make sure that the SACK chunk has a valid length. */
3407 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_sack_chunk)))
3408 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3409 commands);
3410
3411 /* Pull the SACK chunk from the data buffer */
3412 sackh = sctp_sm_pull_sack(chunk);
3413 /* Was this a bogus SACK? */
3414 if (!sackh)
3415 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3416 chunk->subh.sack_hdr = sackh;
3417 ctsn = ntohl(sackh->cum_tsn_ack);
3418
3419 /* If Cumulative TSN Ack beyond the max tsn currently
3420 * send, terminating the association and respond to the
3421 * sender with an ABORT.
3422 */
3423 if (TSN_lte(asoc->next_tsn, ctsn))
3424 return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands);
3425
3426 trace_sctp_probe(ep, asoc, chunk);
3427
3428 /* i) If Cumulative TSN Ack is less than the Cumulative TSN
3429 * Ack Point, then drop the SACK. Since Cumulative TSN
3430 * Ack is monotonically increasing, a SACK whose
3431 * Cumulative TSN Ack is less than the Cumulative TSN Ack
3432 * Point indicates an out-of-order SACK.
3433 */
3434 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
3435 pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn,
3436 asoc->ctsn_ack_point);
3437
3438 return SCTP_DISPOSITION_DISCARD;
3439 }
3440
3441 /* Return this SACK for further processing. */
3442 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_CHUNK(chunk));
3443
3444 /* Note: We do the rest of the work on the PROCESS_SACK
3445 * sideeffect.
3446 */
3447 return SCTP_DISPOSITION_CONSUME;
3448}
3449
3450/*
3451 * Generate an ABORT in response to a packet.
3452 *
3453 * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41
3454 *
3455 * 8) The receiver should respond to the sender of the OOTB packet with
3456 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3457 * MUST fill in the Verification Tag field of the outbound packet
3458 * with the value found in the Verification Tag field of the OOTB
3459 * packet and set the T-bit in the Chunk Flags to indicate that the
3460 * Verification Tag is reflected. After sending this ABORT, the
3461 * receiver of the OOTB packet shall discard the OOTB packet and take
3462 * no further action.
3463 *
3464 * Verification Tag:
3465 *
3466 * The return value is the disposition of the chunk.
3467*/
3468static enum sctp_disposition sctp_sf_tabort_8_4_8(
3469 struct net *net,
3470 const struct sctp_endpoint *ep,
3471 const struct sctp_association *asoc,
3472 const union sctp_subtype type,
3473 void *arg,
3474 struct sctp_cmd_seq *commands)
3475{
3476 struct sctp_packet *packet = NULL;
3477 struct sctp_chunk *chunk = arg;
3478 struct sctp_chunk *abort;
3479
3480 packet = sctp_ootb_pkt_new(net, asoc, chunk);
3481 if (!packet)
3482 return SCTP_DISPOSITION_NOMEM;
3483
3484 /* Make an ABORT. The T bit will be set if the asoc
3485 * is NULL.
3486 */
3487 abort = sctp_make_abort(asoc, chunk, 0);
3488 if (!abort) {
3489 sctp_ootb_pkt_free(packet);
3490 return SCTP_DISPOSITION_NOMEM;
3491 }
3492
3493 /* Reflect vtag if T-Bit is set */
3494 if (sctp_test_T_bit(abort))
3495 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3496
3497 /* Set the skb to the belonging sock for accounting. */
3498 abort->skb->sk = ep->base.sk;
3499
3500 sctp_packet_append_chunk(packet, abort);
3501
3502 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, SCTP_PACKET(packet));
3503
3504 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
3505
3506 sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3507 return SCTP_DISPOSITION_CONSUME;
3508}
3509
3510/* Handling of SCTP Packets Containing an INIT Chunk Matching an
3511 * Existing Associations when the UDP encap port is incorrect.
3512 *
3513 * From Section 4 at draft-tuexen-tsvwg-sctp-udp-encaps-cons-03.
3514 */
3515static enum sctp_disposition sctp_sf_new_encap_port(
3516 struct net *net,
3517 const struct sctp_endpoint *ep,
3518 const struct sctp_association *asoc,
3519 const union sctp_subtype type,
3520 void *arg,
3521 struct sctp_cmd_seq *commands)
3522{
3523 struct sctp_packet *packet = NULL;
3524 struct sctp_chunk *chunk = arg;
3525 struct sctp_chunk *abort;
3526
3527 packet = sctp_ootb_pkt_new(net, asoc, chunk);
3528 if (!packet)
3529 return SCTP_DISPOSITION_NOMEM;
3530
3531 abort = sctp_make_new_encap_port(asoc, chunk);
3532 if (!abort) {
3533 sctp_ootb_pkt_free(packet);
3534 return SCTP_DISPOSITION_NOMEM;
3535 }
3536
3537 abort->skb->sk = ep->base.sk;
3538
3539 sctp_packet_append_chunk(packet, abort);
3540
3541 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3542 SCTP_PACKET(packet));
3543
3544 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
3545
3546 sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3547 return SCTP_DISPOSITION_CONSUME;
3548}
3549
3550/*
3551 * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR
3552 * event as ULP notification for each cause included in the chunk.
3553 *
3554 * API 5.3.1.3 - SCTP_REMOTE_ERROR
3555 *
3556 * The return value is the disposition of the chunk.
3557*/
3558enum sctp_disposition sctp_sf_operr_notify(struct net *net,
3559 const struct sctp_endpoint *ep,
3560 const struct sctp_association *asoc,
3561 const union sctp_subtype type,
3562 void *arg,
3563 struct sctp_cmd_seq *commands)
3564{
3565 struct sctp_chunk *chunk = arg;
3566 struct sctp_errhdr *err;
3567
3568 if (!sctp_vtag_verify(chunk, asoc))
3569 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3570
3571 /* Make sure that the ERROR chunk has a valid length. */
3572 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_operr_chunk)))
3573 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3574 commands);
3575 sctp_walk_errors(err, chunk->chunk_hdr);
3576 if ((void *)err != (void *)chunk->chunk_end)
3577 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
3578 (void *)err, commands);
3579
3580 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_OPERR,
3581 SCTP_CHUNK(chunk));
3582
3583 return SCTP_DISPOSITION_CONSUME;
3584}
3585
3586/*
3587 * Process an inbound SHUTDOWN ACK.
3588 *
3589 * From Section 9.2:
3590 * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3591 * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its
3592 * peer, and remove all record of the association.
3593 *
3594 * The return value is the disposition.
3595 */
3596enum sctp_disposition sctp_sf_do_9_2_final(struct net *net,
3597 const struct sctp_endpoint *ep,
3598 const struct sctp_association *asoc,
3599 const union sctp_subtype type,
3600 void *arg,
3601 struct sctp_cmd_seq *commands)
3602{
3603 struct sctp_chunk *chunk = arg;
3604 struct sctp_chunk *reply;
3605 struct sctp_ulpevent *ev;
3606
3607 if (!sctp_vtag_verify(chunk, asoc))
3608 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3609
3610 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3611 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr)))
3612 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3613 commands);
3614 /* 10.2 H) SHUTDOWN COMPLETE notification
3615 *
3616 * When SCTP completes the shutdown procedures (section 9.2) this
3617 * notification is passed to the upper layer.
3618 */
3619 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
3620 0, 0, 0, NULL, GFP_ATOMIC);
3621 if (!ev)
3622 goto nomem;
3623
3624 /* ...send a SHUTDOWN COMPLETE chunk to its peer, */
3625 reply = sctp_make_shutdown_complete(asoc, chunk);
3626 if (!reply)
3627 goto nomem_chunk;
3628
3629 /* Do all the commands now (after allocation), so that we
3630 * have consistent state if memory allocation fails
3631 */
3632 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
3633
3634 /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3635 * stop the T2-shutdown timer,
3636 */
3637 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3638 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3639
3640 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3641 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
3642
3643 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3644 SCTP_STATE(SCTP_STATE_CLOSED));
3645 SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS);
3646 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
3647 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
3648
3649 /* ...and remove all record of the association. */
3650 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
3651 return SCTP_DISPOSITION_DELETE_TCB;
3652
3653nomem_chunk:
3654 sctp_ulpevent_free(ev);
3655nomem:
3656 return SCTP_DISPOSITION_NOMEM;
3657}
3658
3659/*
3660 * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41.
3661 *
3662 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3663 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3664 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3665 * packet must fill in the Verification Tag field of the outbound
3666 * packet with the Verification Tag received in the SHUTDOWN ACK and
3667 * set the T-bit in the Chunk Flags to indicate that the Verification
3668 * Tag is reflected.
3669 *
3670 * 8) The receiver should respond to the sender of the OOTB packet with
3671 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3672 * MUST fill in the Verification Tag field of the outbound packet
3673 * with the value found in the Verification Tag field of the OOTB
3674 * packet and set the T-bit in the Chunk Flags to indicate that the
3675 * Verification Tag is reflected. After sending this ABORT, the
3676 * receiver of the OOTB packet shall discard the OOTB packet and take
3677 * no further action.
3678 */
3679enum sctp_disposition sctp_sf_ootb(struct net *net,
3680 const struct sctp_endpoint *ep,
3681 const struct sctp_association *asoc,
3682 const union sctp_subtype type,
3683 void *arg, struct sctp_cmd_seq *commands)
3684{
3685 struct sctp_chunk *chunk = arg;
3686 struct sk_buff *skb = chunk->skb;
3687 struct sctp_chunkhdr *ch;
3688 struct sctp_errhdr *err;
3689 int ootb_cookie_ack = 0;
3690 int ootb_shut_ack = 0;
3691 __u8 *ch_end;
3692
3693 SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
3694
3695 if (asoc && !sctp_vtag_verify(chunk, asoc))
3696 asoc = NULL;
3697
3698 ch = (struct sctp_chunkhdr *)chunk->chunk_hdr;
3699 do {
3700 /* Report violation if the chunk is less then minimal */
3701 if (ntohs(ch->length) < sizeof(*ch))
3702 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3703 commands);
3704
3705 /* Report violation if chunk len overflows */
3706 ch_end = ((__u8 *)ch) + SCTP_PAD4(ntohs(ch->length));
3707 if (ch_end > skb_tail_pointer(skb))
3708 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3709 commands);
3710
3711 /* Now that we know we at least have a chunk header,
3712 * do things that are type appropriate.
3713 */
3714 if (SCTP_CID_SHUTDOWN_ACK == ch->type)
3715 ootb_shut_ack = 1;
3716
3717 /* RFC 2960, Section 3.3.7
3718 * Moreover, under any circumstances, an endpoint that
3719 * receives an ABORT MUST NOT respond to that ABORT by
3720 * sending an ABORT of its own.
3721 */
3722 if (SCTP_CID_ABORT == ch->type)
3723 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3724
3725 /* RFC 8.4, 7) If the packet contains a "Stale cookie" ERROR
3726 * or a COOKIE ACK the SCTP Packet should be silently
3727 * discarded.
3728 */
3729
3730 if (SCTP_CID_COOKIE_ACK == ch->type)
3731 ootb_cookie_ack = 1;
3732
3733 if (SCTP_CID_ERROR == ch->type) {
3734 sctp_walk_errors(err, ch) {
3735 if (SCTP_ERROR_STALE_COOKIE == err->cause) {
3736 ootb_cookie_ack = 1;
3737 break;
3738 }
3739 }
3740 }
3741
3742 ch = (struct sctp_chunkhdr *)ch_end;
3743 } while (ch_end < skb_tail_pointer(skb));
3744
3745 if (ootb_shut_ack)
3746 return sctp_sf_shut_8_4_5(net, ep, asoc, type, arg, commands);
3747 else if (ootb_cookie_ack)
3748 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3749 else
3750 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
3751}
3752
3753/*
3754 * Handle an "Out of the blue" SHUTDOWN ACK.
3755 *
3756 * Section: 8.4 5, sctpimpguide 2.41.
3757 *
3758 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3759 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3760 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3761 * packet must fill in the Verification Tag field of the outbound
3762 * packet with the Verification Tag received in the SHUTDOWN ACK and
3763 * set the T-bit in the Chunk Flags to indicate that the Verification
3764 * Tag is reflected.
3765 *
3766 * Inputs
3767 * (endpoint, asoc, type, arg, commands)
3768 *
3769 * Outputs
3770 * (enum sctp_disposition)
3771 *
3772 * The return value is the disposition of the chunk.
3773 */
3774static enum sctp_disposition sctp_sf_shut_8_4_5(
3775 struct net *net,
3776 const struct sctp_endpoint *ep,
3777 const struct sctp_association *asoc,
3778 const union sctp_subtype type,
3779 void *arg,
3780 struct sctp_cmd_seq *commands)
3781{
3782 struct sctp_packet *packet = NULL;
3783 struct sctp_chunk *chunk = arg;
3784 struct sctp_chunk *shut;
3785
3786 packet = sctp_ootb_pkt_new(net, asoc, chunk);
3787 if (!packet)
3788 return SCTP_DISPOSITION_NOMEM;
3789
3790 /* Make an SHUTDOWN_COMPLETE.
3791 * The T bit will be set if the asoc is NULL.
3792 */
3793 shut = sctp_make_shutdown_complete(asoc, chunk);
3794 if (!shut) {
3795 sctp_ootb_pkt_free(packet);
3796 return SCTP_DISPOSITION_NOMEM;
3797 }
3798
3799 /* Reflect vtag if T-Bit is set */
3800 if (sctp_test_T_bit(shut))
3801 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3802
3803 /* Set the skb to the belonging sock for accounting. */
3804 shut->skb->sk = ep->base.sk;
3805
3806 sctp_packet_append_chunk(packet, shut);
3807
3808 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3809 SCTP_PACKET(packet));
3810
3811 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
3812
3813 /* We need to discard the rest of the packet to prevent
3814 * potential boomming attacks from additional bundled chunks.
3815 * This is documented in SCTP Threats ID.
3816 */
3817 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3818}
3819
3820/*
3821 * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state.
3822 *
3823 * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK
3824 * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the
3825 * procedures in section 8.4 SHOULD be followed, in other words it
3826 * should be treated as an Out Of The Blue packet.
3827 * [This means that we do NOT check the Verification Tag on these
3828 * chunks. --piggy ]
3829 *
3830 */
3831enum sctp_disposition sctp_sf_do_8_5_1_E_sa(struct net *net,
3832 const struct sctp_endpoint *ep,
3833 const struct sctp_association *asoc,
3834 const union sctp_subtype type,
3835 void *arg,
3836 struct sctp_cmd_seq *commands)
3837{
3838 struct sctp_chunk *chunk = arg;
3839
3840 if (!sctp_vtag_verify(chunk, asoc))
3841 asoc = NULL;
3842
3843 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3844 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr)))
3845 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3846 commands);
3847
3848 /* Although we do have an association in this case, it corresponds
3849 * to a restarted association. So the packet is treated as an OOTB
3850 * packet and the state function that handles OOTB SHUTDOWN_ACK is
3851 * called with a NULL association.
3852 */
3853 SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
3854
3855 return sctp_sf_shut_8_4_5(net, ep, NULL, type, arg, commands);
3856}
3857
3858/* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */
3859enum sctp_disposition sctp_sf_do_asconf(struct net *net,
3860 const struct sctp_endpoint *ep,
3861 const struct sctp_association *asoc,
3862 const union sctp_subtype type,
3863 void *arg,
3864 struct sctp_cmd_seq *commands)
3865{
3866 struct sctp_paramhdr *err_param = NULL;
3867 struct sctp_chunk *asconf_ack = NULL;
3868 struct sctp_chunk *chunk = arg;
3869 struct sctp_addiphdr *hdr;
3870 __u32 serial;
3871
3872 if (!sctp_vtag_verify(chunk, asoc)) {
3873 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3874 SCTP_NULL());
3875 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3876 }
3877
3878 /* Make sure that the ASCONF ADDIP chunk has a valid length. */
3879 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_addip_chunk)))
3880 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3881 commands);
3882
3883 /* ADD-IP: Section 4.1.1
3884 * This chunk MUST be sent in an authenticated way by using
3885 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3886 * is received unauthenticated it MUST be silently discarded as
3887 * described in [I-D.ietf-tsvwg-sctp-auth].
3888 */
3889 if (!asoc->peer.asconf_capable ||
3890 (!net->sctp.addip_noauth && !chunk->auth))
3891 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3892
3893 hdr = (struct sctp_addiphdr *)chunk->skb->data;
3894 serial = ntohl(hdr->serial);
3895
3896 /* Verify the ASCONF chunk before processing it. */
3897 if (!sctp_verify_asconf(asoc, chunk, true, &err_param))
3898 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
3899 (void *)err_param, commands);
3900
3901 /* ADDIP 5.2 E1) Compare the value of the serial number to the value
3902 * the endpoint stored in a new association variable
3903 * 'Peer-Serial-Number'.
3904 */
3905 if (serial == asoc->peer.addip_serial + 1) {
3906 /* If this is the first instance of ASCONF in the packet,
3907 * we can clean our old ASCONF-ACKs.
3908 */
3909 if (!chunk->has_asconf)
3910 sctp_assoc_clean_asconf_ack_cache(asoc);
3911
3912 /* ADDIP 5.2 E4) When the Sequence Number matches the next one
3913 * expected, process the ASCONF as described below and after
3914 * processing the ASCONF Chunk, append an ASCONF-ACK Chunk to
3915 * the response packet and cache a copy of it (in the event it
3916 * later needs to be retransmitted).
3917 *
3918 * Essentially, do V1-V5.
3919 */
3920 asconf_ack = sctp_process_asconf((struct sctp_association *)
3921 asoc, chunk);
3922 if (!asconf_ack)
3923 return SCTP_DISPOSITION_NOMEM;
3924 } else if (serial < asoc->peer.addip_serial + 1) {
3925 /* ADDIP 5.2 E2)
3926 * If the value found in the Sequence Number is less than the
3927 * ('Peer- Sequence-Number' + 1), simply skip to the next
3928 * ASCONF, and include in the outbound response packet
3929 * any previously cached ASCONF-ACK response that was
3930 * sent and saved that matches the Sequence Number of the
3931 * ASCONF. Note: It is possible that no cached ASCONF-ACK
3932 * Chunk exists. This will occur when an older ASCONF
3933 * arrives out of order. In such a case, the receiver
3934 * should skip the ASCONF Chunk and not include ASCONF-ACK
3935 * Chunk for that chunk.
3936 */
3937 asconf_ack = sctp_assoc_lookup_asconf_ack(asoc, hdr->serial);
3938 if (!asconf_ack)
3939 return SCTP_DISPOSITION_DISCARD;
3940
3941 /* Reset the transport so that we select the correct one
3942 * this time around. This is to make sure that we don't
3943 * accidentally use a stale transport that's been removed.
3944 */
3945 asconf_ack->transport = NULL;
3946 } else {
3947 /* ADDIP 5.2 E5) Otherwise, the ASCONF Chunk is discarded since
3948 * it must be either a stale packet or from an attacker.
3949 */
3950 return SCTP_DISPOSITION_DISCARD;
3951 }
3952
3953 /* ADDIP 5.2 E6) The destination address of the SCTP packet
3954 * containing the ASCONF-ACK Chunks MUST be the source address of
3955 * the SCTP packet that held the ASCONF Chunks.
3956 *
3957 * To do this properly, we'll set the destination address of the chunk
3958 * and at the transmit time, will try look up the transport to use.
3959 * Since ASCONFs may be bundled, the correct transport may not be
3960 * created until we process the entire packet, thus this workaround.
3961 */
3962 asconf_ack->dest = chunk->source;
3963 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(asconf_ack));
3964 if (asoc->new_transport) {
3965 sctp_sf_heartbeat(ep, asoc, type, asoc->new_transport, commands);
3966 ((struct sctp_association *)asoc)->new_transport = NULL;
3967 }
3968
3969 return SCTP_DISPOSITION_CONSUME;
3970}
3971
3972static enum sctp_disposition sctp_send_next_asconf(
3973 struct net *net,
3974 const struct sctp_endpoint *ep,
3975 struct sctp_association *asoc,
3976 const union sctp_subtype type,
3977 struct sctp_cmd_seq *commands)
3978{
3979 struct sctp_chunk *asconf;
3980 struct list_head *entry;
3981
3982 if (list_empty(&asoc->addip_chunk_list))
3983 return SCTP_DISPOSITION_CONSUME;
3984
3985 entry = asoc->addip_chunk_list.next;
3986 asconf = list_entry(entry, struct sctp_chunk, list);
3987
3988 list_del_init(entry);
3989 sctp_chunk_hold(asconf);
3990 asoc->addip_last_asconf = asconf;
3991
3992 return sctp_sf_do_prm_asconf(net, ep, asoc, type, asconf, commands);
3993}
3994
3995/*
3996 * ADDIP Section 4.3 General rules for address manipulation
3997 * When building TLV parameters for the ASCONF Chunk that will add or
3998 * delete IP addresses the D0 to D13 rules should be applied:
3999 */
4000enum sctp_disposition sctp_sf_do_asconf_ack(struct net *net,
4001 const struct sctp_endpoint *ep,
4002 const struct sctp_association *asoc,
4003 const union sctp_subtype type,
4004 void *arg,
4005 struct sctp_cmd_seq *commands)
4006{
4007 struct sctp_chunk *last_asconf = asoc->addip_last_asconf;
4008 struct sctp_paramhdr *err_param = NULL;
4009 struct sctp_chunk *asconf_ack = arg;
4010 struct sctp_addiphdr *addip_hdr;
4011 __u32 sent_serial, rcvd_serial;
4012 struct sctp_chunk *abort;
4013
4014 if (!sctp_vtag_verify(asconf_ack, asoc)) {
4015 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
4016 SCTP_NULL());
4017 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4018 }
4019
4020 /* Make sure that the ADDIP chunk has a valid length. */
4021 if (!sctp_chunk_length_valid(asconf_ack,
4022 sizeof(struct sctp_addip_chunk)))
4023 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
4024 commands);
4025
4026 /* ADD-IP, Section 4.1.2:
4027 * This chunk MUST be sent in an authenticated way by using
4028 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
4029 * is received unauthenticated it MUST be silently discarded as
4030 * described in [I-D.ietf-tsvwg-sctp-auth].
4031 */
4032 if (!asoc->peer.asconf_capable ||
4033 (!net->sctp.addip_noauth && !asconf_ack->auth))
4034 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4035
4036 addip_hdr = (struct sctp_addiphdr *)asconf_ack->skb->data;
4037 rcvd_serial = ntohl(addip_hdr->serial);
4038
4039 /* Verify the ASCONF-ACK chunk before processing it. */
4040 if (!sctp_verify_asconf(asoc, asconf_ack, false, &err_param))
4041 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
4042 (void *)err_param, commands);
4043
4044 if (last_asconf) {
4045 addip_hdr = last_asconf->subh.addip_hdr;
4046 sent_serial = ntohl(addip_hdr->serial);
4047 } else {
4048 sent_serial = asoc->addip_serial - 1;
4049 }
4050
4051 /* D0) If an endpoint receives an ASCONF-ACK that is greater than or
4052 * equal to the next serial number to be used but no ASCONF chunk is
4053 * outstanding the endpoint MUST ABORT the association. Note that a
4054 * sequence number is greater than if it is no more than 2^^31-1
4055 * larger than the current sequence number (using serial arithmetic).
4056 */
4057 if (ADDIP_SERIAL_gte(rcvd_serial, sent_serial + 1) &&
4058 !(asoc->addip_last_asconf)) {
4059 abort = sctp_make_abort(asoc, asconf_ack,
4060 sizeof(struct sctp_errhdr));
4061 if (abort) {
4062 sctp_init_cause(abort, SCTP_ERROR_ASCONF_ACK, 0);
4063 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4064 SCTP_CHUNK(abort));
4065 }
4066 /* We are going to ABORT, so we might as well stop
4067 * processing the rest of the chunks in the packet.
4068 */
4069 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4070 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
4071 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
4072 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4073 SCTP_ERROR(ECONNABORTED));
4074 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4075 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
4076 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
4077 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
4078 return SCTP_DISPOSITION_ABORT;
4079 }
4080
4081 if ((rcvd_serial == sent_serial) && asoc->addip_last_asconf) {
4082 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4083 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
4084
4085 if (!sctp_process_asconf_ack((struct sctp_association *)asoc,
4086 asconf_ack))
4087 return sctp_send_next_asconf(net, ep,
4088 (struct sctp_association *)asoc,
4089 type, commands);
4090
4091 abort = sctp_make_abort(asoc, asconf_ack,
4092 sizeof(struct sctp_errhdr));
4093 if (abort) {
4094 sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0);
4095 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4096 SCTP_CHUNK(abort));
4097 }
4098 /* We are going to ABORT, so we might as well stop
4099 * processing the rest of the chunks in the packet.
4100 */
4101 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
4102 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4103 SCTP_ERROR(ECONNABORTED));
4104 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4105 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
4106 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
4107 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
4108 return SCTP_DISPOSITION_ABORT;
4109 }
4110
4111 return SCTP_DISPOSITION_DISCARD;
4112}
4113
4114/* RE-CONFIG Section 5.2 Upon reception of an RECONF Chunk. */
4115enum sctp_disposition sctp_sf_do_reconf(struct net *net,
4116 const struct sctp_endpoint *ep,
4117 const struct sctp_association *asoc,
4118 const union sctp_subtype type,
4119 void *arg,
4120 struct sctp_cmd_seq *commands)
4121{
4122 struct sctp_paramhdr *err_param = NULL;
4123 struct sctp_chunk *chunk = arg;
4124 struct sctp_reconf_chunk *hdr;
4125 union sctp_params param;
4126
4127 if (!sctp_vtag_verify(chunk, asoc)) {
4128 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
4129 SCTP_NULL());
4130 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4131 }
4132
4133 /* Make sure that the RECONF chunk has a valid length. */
4134 if (!sctp_chunk_length_valid(chunk, sizeof(*hdr)))
4135 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
4136 commands);
4137
4138 if (!sctp_verify_reconf(asoc, chunk, &err_param))
4139 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
4140 (void *)err_param, commands);
4141
4142 hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr;
4143 sctp_walk_params(param, hdr) {
4144 struct sctp_chunk *reply = NULL;
4145 struct sctp_ulpevent *ev = NULL;
4146
4147 if (param.p->type == SCTP_PARAM_RESET_OUT_REQUEST)
4148 reply = sctp_process_strreset_outreq(
4149 (struct sctp_association *)asoc, param, &ev);
4150 else if (param.p->type == SCTP_PARAM_RESET_IN_REQUEST)
4151 reply = sctp_process_strreset_inreq(
4152 (struct sctp_association *)asoc, param, &ev);
4153 else if (param.p->type == SCTP_PARAM_RESET_TSN_REQUEST)
4154 reply = sctp_process_strreset_tsnreq(
4155 (struct sctp_association *)asoc, param, &ev);
4156 else if (param.p->type == SCTP_PARAM_RESET_ADD_OUT_STREAMS)
4157 reply = sctp_process_strreset_addstrm_out(
4158 (struct sctp_association *)asoc, param, &ev);
4159 else if (param.p->type == SCTP_PARAM_RESET_ADD_IN_STREAMS)
4160 reply = sctp_process_strreset_addstrm_in(
4161 (struct sctp_association *)asoc, param, &ev);
4162 else if (param.p->type == SCTP_PARAM_RESET_RESPONSE)
4163 reply = sctp_process_strreset_resp(
4164 (struct sctp_association *)asoc, param, &ev);
4165
4166 if (ev)
4167 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
4168 SCTP_ULPEVENT(ev));
4169
4170 if (reply)
4171 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4172 SCTP_CHUNK(reply));
4173 }
4174
4175 return SCTP_DISPOSITION_CONSUME;
4176}
4177
4178/*
4179 * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP
4180 *
4181 * When a FORWARD TSN chunk arrives, the data receiver MUST first update
4182 * its cumulative TSN point to the value carried in the FORWARD TSN
4183 * chunk, and then MUST further advance its cumulative TSN point locally
4184 * if possible.
4185 * After the above processing, the data receiver MUST stop reporting any
4186 * missing TSNs earlier than or equal to the new cumulative TSN point.
4187 *
4188 * Verification Tag: 8.5 Verification Tag [Normal verification]
4189 *
4190 * The return value is the disposition of the chunk.
4191 */
4192enum sctp_disposition sctp_sf_eat_fwd_tsn(struct net *net,
4193 const struct sctp_endpoint *ep,
4194 const struct sctp_association *asoc,
4195 const union sctp_subtype type,
4196 void *arg,
4197 struct sctp_cmd_seq *commands)
4198{
4199 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
4200 struct sctp_chunk *chunk = arg;
4201 __u16 len;
4202 __u32 tsn;
4203
4204 if (!sctp_vtag_verify(chunk, asoc)) {
4205 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
4206 SCTP_NULL());
4207 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4208 }
4209
4210 if (!asoc->peer.prsctp_capable)
4211 return sctp_sf_unk_chunk(net, ep, asoc, type, arg, commands);
4212
4213 /* Make sure that the FORWARD_TSN chunk has valid length. */
4214 if (!sctp_chunk_length_valid(chunk, sctp_ftsnchk_len(&asoc->stream)))
4215 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
4216 commands);
4217
4218 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
4219 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
4220 len = ntohs(chunk->chunk_hdr->length);
4221 len -= sizeof(struct sctp_chunkhdr);
4222 skb_pull(chunk->skb, len);
4223
4224 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
4225 pr_debug("%s: TSN 0x%x\n", __func__, tsn);
4226
4227 /* The TSN is too high--silently discard the chunk and count on it
4228 * getting retransmitted later.
4229 */
4230 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
4231 goto discard_noforce;
4232
4233 if (!asoc->stream.si->validate_ftsn(chunk))
4234 goto discard_noforce;
4235
4236 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
4237 if (len > sctp_ftsnhdr_len(&asoc->stream))
4238 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
4239 SCTP_CHUNK(chunk));
4240
4241 /* Count this as receiving DATA. */
4242 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) {
4243 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
4244 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
4245 }
4246
4247 /* FIXME: For now send a SACK, but DATA processing may
4248 * send another.
4249 */
4250 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
4251
4252 return SCTP_DISPOSITION_CONSUME;
4253
4254discard_noforce:
4255 return SCTP_DISPOSITION_DISCARD;
4256}
4257
4258enum sctp_disposition sctp_sf_eat_fwd_tsn_fast(
4259 struct net *net,
4260 const struct sctp_endpoint *ep,
4261 const struct sctp_association *asoc,
4262 const union sctp_subtype type,
4263 void *arg,
4264 struct sctp_cmd_seq *commands)
4265{
4266 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
4267 struct sctp_chunk *chunk = arg;
4268 __u16 len;
4269 __u32 tsn;
4270
4271 if (!sctp_vtag_verify(chunk, asoc)) {
4272 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
4273 SCTP_NULL());
4274 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4275 }
4276
4277 if (!asoc->peer.prsctp_capable)
4278 return sctp_sf_unk_chunk(net, ep, asoc, type, arg, commands);
4279
4280 /* Make sure that the FORWARD_TSN chunk has a valid length. */
4281 if (!sctp_chunk_length_valid(chunk, sctp_ftsnchk_len(&asoc->stream)))
4282 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
4283 commands);
4284
4285 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
4286 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
4287 len = ntohs(chunk->chunk_hdr->length);
4288 len -= sizeof(struct sctp_chunkhdr);
4289 skb_pull(chunk->skb, len);
4290
4291 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
4292 pr_debug("%s: TSN 0x%x\n", __func__, tsn);
4293
4294 /* The TSN is too high--silently discard the chunk and count on it
4295 * getting retransmitted later.
4296 */
4297 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
4298 goto gen_shutdown;
4299
4300 if (!asoc->stream.si->validate_ftsn(chunk))
4301 goto gen_shutdown;
4302
4303 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
4304 if (len > sctp_ftsnhdr_len(&asoc->stream))
4305 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
4306 SCTP_CHUNK(chunk));
4307
4308 /* Go a head and force a SACK, since we are shutting down. */
4309gen_shutdown:
4310 /* Implementor's Guide.
4311 *
4312 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
4313 * respond to each received packet containing one or more DATA chunk(s)
4314 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
4315 */
4316 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
4317 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
4318 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
4319 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4320
4321 return SCTP_DISPOSITION_CONSUME;
4322}
4323
4324/*
4325 * SCTP-AUTH Section 6.3 Receiving authenticated chunks
4326 *
4327 * The receiver MUST use the HMAC algorithm indicated in the HMAC
4328 * Identifier field. If this algorithm was not specified by the
4329 * receiver in the HMAC-ALGO parameter in the INIT or INIT-ACK chunk
4330 * during association setup, the AUTH chunk and all chunks after it MUST
4331 * be discarded and an ERROR chunk SHOULD be sent with the error cause
4332 * defined in Section 4.1.
4333 *
4334 * If an endpoint with no shared key receives a Shared Key Identifier
4335 * other than 0, it MUST silently discard all authenticated chunks. If
4336 * the endpoint has at least one endpoint pair shared key for the peer,
4337 * it MUST use the key specified by the Shared Key Identifier if a
4338 * key has been configured for that Shared Key Identifier. If no
4339 * endpoint pair shared key has been configured for that Shared Key
4340 * Identifier, all authenticated chunks MUST be silently discarded.
4341 *
4342 * Verification Tag: 8.5 Verification Tag [Normal verification]
4343 *
4344 * The return value is the disposition of the chunk.
4345 */
4346static enum sctp_ierror sctp_sf_authenticate(
4347 const struct sctp_association *asoc,
4348 struct sctp_chunk *chunk)
4349{
4350 struct sctp_shared_key *sh_key = NULL;
4351 struct sctp_authhdr *auth_hdr;
4352 __u8 *save_digest, *digest;
4353 struct sctp_hmac *hmac;
4354 unsigned int sig_len;
4355 __u16 key_id;
4356
4357 /* Pull in the auth header, so we can do some more verification */
4358 auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
4359 chunk->subh.auth_hdr = auth_hdr;
4360 skb_pull(chunk->skb, sizeof(*auth_hdr));
4361
4362 /* Make sure that we support the HMAC algorithm from the auth
4363 * chunk.
4364 */
4365 if (!sctp_auth_asoc_verify_hmac_id(asoc, auth_hdr->hmac_id))
4366 return SCTP_IERROR_AUTH_BAD_HMAC;
4367
4368 /* Make sure that the provided shared key identifier has been
4369 * configured
4370 */
4371 key_id = ntohs(auth_hdr->shkey_id);
4372 if (key_id != asoc->active_key_id) {
4373 sh_key = sctp_auth_get_shkey(asoc, key_id);
4374 if (!sh_key)
4375 return SCTP_IERROR_AUTH_BAD_KEYID;
4376 }
4377
4378 /* Make sure that the length of the signature matches what
4379 * we expect.
4380 */
4381 sig_len = ntohs(chunk->chunk_hdr->length) -
4382 sizeof(struct sctp_auth_chunk);
4383 hmac = sctp_auth_get_hmac(ntohs(auth_hdr->hmac_id));
4384 if (sig_len != hmac->hmac_len)
4385 return SCTP_IERROR_PROTO_VIOLATION;
4386
4387 /* Now that we've done validation checks, we can compute and
4388 * verify the hmac. The steps involved are:
4389 * 1. Save the digest from the chunk.
4390 * 2. Zero out the digest in the chunk.
4391 * 3. Compute the new digest
4392 * 4. Compare saved and new digests.
4393 */
4394 digest = (u8 *)(auth_hdr + 1);
4395 skb_pull(chunk->skb, sig_len);
4396
4397 save_digest = kmemdup(digest, sig_len, GFP_ATOMIC);
4398 if (!save_digest)
4399 goto nomem;
4400
4401 memset(digest, 0, sig_len);
4402
4403 sctp_auth_calculate_hmac(asoc, chunk->skb,
4404 (struct sctp_auth_chunk *)chunk->chunk_hdr,
4405 sh_key, GFP_ATOMIC);
4406
4407 /* Discard the packet if the digests do not match */
4408 if (memcmp(save_digest, digest, sig_len)) {
4409 kfree(save_digest);
4410 return SCTP_IERROR_BAD_SIG;
4411 }
4412
4413 kfree(save_digest);
4414 chunk->auth = 1;
4415
4416 return SCTP_IERROR_NO_ERROR;
4417nomem:
4418 return SCTP_IERROR_NOMEM;
4419}
4420
4421enum sctp_disposition sctp_sf_eat_auth(struct net *net,
4422 const struct sctp_endpoint *ep,
4423 const struct sctp_association *asoc,
4424 const union sctp_subtype type,
4425 void *arg, struct sctp_cmd_seq *commands)
4426{
4427 struct sctp_chunk *chunk = arg;
4428 struct sctp_authhdr *auth_hdr;
4429 struct sctp_chunk *err_chunk;
4430 enum sctp_ierror error;
4431
4432 /* Make sure that the peer has AUTH capable */
4433 if (!asoc->peer.auth_capable)
4434 return sctp_sf_unk_chunk(net, ep, asoc, type, arg, commands);
4435
4436 if (!sctp_vtag_verify(chunk, asoc)) {
4437 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
4438 SCTP_NULL());
4439 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4440 }
4441
4442 /* Make sure that the AUTH chunk has valid length. */
4443 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_auth_chunk)))
4444 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
4445 commands);
4446
4447 auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
4448 error = sctp_sf_authenticate(asoc, chunk);
4449 switch (error) {
4450 case SCTP_IERROR_AUTH_BAD_HMAC:
4451 /* Generate the ERROR chunk and discard the rest
4452 * of the packet
4453 */
4454 err_chunk = sctp_make_op_error(asoc, chunk,
4455 SCTP_ERROR_UNSUP_HMAC,
4456 &auth_hdr->hmac_id,
4457 sizeof(__u16), 0);
4458 if (err_chunk) {
4459 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4460 SCTP_CHUNK(err_chunk));
4461 }
4462 fallthrough;
4463 case SCTP_IERROR_AUTH_BAD_KEYID:
4464 case SCTP_IERROR_BAD_SIG:
4465 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4466
4467 case SCTP_IERROR_PROTO_VIOLATION:
4468 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
4469 commands);
4470
4471 case SCTP_IERROR_NOMEM:
4472 return SCTP_DISPOSITION_NOMEM;
4473
4474 default: /* Prevent gcc warnings */
4475 break;
4476 }
4477
4478 if (asoc->active_key_id != ntohs(auth_hdr->shkey_id)) {
4479 struct sctp_ulpevent *ev;
4480
4481 ev = sctp_ulpevent_make_authkey(asoc, ntohs(auth_hdr->shkey_id),
4482 SCTP_AUTH_NEW_KEY, GFP_ATOMIC);
4483
4484 if (!ev)
4485 return SCTP_DISPOSITION_NOMEM;
4486
4487 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
4488 SCTP_ULPEVENT(ev));
4489 }
4490
4491 return SCTP_DISPOSITION_CONSUME;
4492}
4493
4494/*
4495 * Process an unknown chunk.
4496 *
4497 * Section: 3.2. Also, 2.1 in the implementor's guide.
4498 *
4499 * Chunk Types are encoded such that the highest-order two bits specify
4500 * the action that must be taken if the processing endpoint does not
4501 * recognize the Chunk Type.
4502 *
4503 * 00 - Stop processing this SCTP packet and discard it, do not process
4504 * any further chunks within it.
4505 *
4506 * 01 - Stop processing this SCTP packet and discard it, do not process
4507 * any further chunks within it, and report the unrecognized
4508 * chunk in an 'Unrecognized Chunk Type'.
4509 *
4510 * 10 - Skip this chunk and continue processing.
4511 *
4512 * 11 - Skip this chunk and continue processing, but report in an ERROR
4513 * Chunk using the 'Unrecognized Chunk Type' cause of error.
4514 *
4515 * The return value is the disposition of the chunk.
4516 */
4517enum sctp_disposition sctp_sf_unk_chunk(struct net *net,
4518 const struct sctp_endpoint *ep,
4519 const struct sctp_association *asoc,
4520 const union sctp_subtype type,
4521 void *arg,
4522 struct sctp_cmd_seq *commands)
4523{
4524 struct sctp_chunk *unk_chunk = arg;
4525 struct sctp_chunk *err_chunk;
4526 struct sctp_chunkhdr *hdr;
4527
4528 pr_debug("%s: processing unknown chunk id:%d\n", __func__, type.chunk);
4529
4530 if (!sctp_vtag_verify(unk_chunk, asoc))
4531 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4532
4533 /* Make sure that the chunk has a valid length.
4534 * Since we don't know the chunk type, we use a general
4535 * chunkhdr structure to make a comparison.
4536 */
4537 if (!sctp_chunk_length_valid(unk_chunk, sizeof(*hdr)))
4538 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
4539 commands);
4540
4541 switch (type.chunk & SCTP_CID_ACTION_MASK) {
4542 case SCTP_CID_ACTION_DISCARD:
4543 /* Discard the packet. */
4544 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4545 case SCTP_CID_ACTION_DISCARD_ERR:
4546 /* Generate an ERROR chunk as response. */
4547 hdr = unk_chunk->chunk_hdr;
4548 err_chunk = sctp_make_op_error(asoc, unk_chunk,
4549 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
4550 SCTP_PAD4(ntohs(hdr->length)),
4551 0);
4552 if (err_chunk) {
4553 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4554 SCTP_CHUNK(err_chunk));
4555 }
4556
4557 /* Discard the packet. */
4558 sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4559 return SCTP_DISPOSITION_CONSUME;
4560 case SCTP_CID_ACTION_SKIP:
4561 /* Skip the chunk. */
4562 return SCTP_DISPOSITION_DISCARD;
4563 case SCTP_CID_ACTION_SKIP_ERR:
4564 /* Generate an ERROR chunk as response. */
4565 hdr = unk_chunk->chunk_hdr;
4566 err_chunk = sctp_make_op_error(asoc, unk_chunk,
4567 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
4568 SCTP_PAD4(ntohs(hdr->length)),
4569 0);
4570 if (err_chunk) {
4571 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4572 SCTP_CHUNK(err_chunk));
4573 }
4574 /* Skip the chunk. */
4575 return SCTP_DISPOSITION_CONSUME;
4576 default:
4577 break;
4578 }
4579
4580 return SCTP_DISPOSITION_DISCARD;
4581}
4582
4583/*
4584 * Discard the chunk.
4585 *
4586 * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2
4587 * [Too numerous to mention...]
4588 * Verification Tag: No verification needed.
4589 * Inputs
4590 * (endpoint, asoc, chunk)
4591 *
4592 * Outputs
4593 * (asoc, reply_msg, msg_up, timers, counters)
4594 *
4595 * The return value is the disposition of the chunk.
4596 */
4597enum sctp_disposition sctp_sf_discard_chunk(struct net *net,
4598 const struct sctp_endpoint *ep,
4599 const struct sctp_association *asoc,
4600 const union sctp_subtype type,
4601 void *arg,
4602 struct sctp_cmd_seq *commands)
4603{
4604 struct sctp_chunk *chunk = arg;
4605
4606 if (asoc && !sctp_vtag_verify(chunk, asoc))
4607 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4608
4609 /* Make sure that the chunk has a valid length.
4610 * Since we don't know the chunk type, we use a general
4611 * chunkhdr structure to make a comparison.
4612 */
4613 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr)))
4614 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
4615 commands);
4616
4617 pr_debug("%s: chunk:%d is discarded\n", __func__, type.chunk);
4618
4619 return SCTP_DISPOSITION_DISCARD;
4620}
4621
4622/*
4623 * Discard the whole packet.
4624 *
4625 * Section: 8.4 2)
4626 *
4627 * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST
4628 * silently discard the OOTB packet and take no further action.
4629 *
4630 * Verification Tag: No verification necessary
4631 *
4632 * Inputs
4633 * (endpoint, asoc, chunk)
4634 *
4635 * Outputs
4636 * (asoc, reply_msg, msg_up, timers, counters)
4637 *
4638 * The return value is the disposition of the chunk.
4639 */
4640enum sctp_disposition sctp_sf_pdiscard(struct net *net,
4641 const struct sctp_endpoint *ep,
4642 const struct sctp_association *asoc,
4643 const union sctp_subtype type,
4644 void *arg, struct sctp_cmd_seq *commands)
4645{
4646 SCTP_INC_STATS(net, SCTP_MIB_IN_PKT_DISCARDS);
4647 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
4648
4649 return SCTP_DISPOSITION_CONSUME;
4650}
4651
4652
4653/*
4654 * The other end is violating protocol.
4655 *
4656 * Section: Not specified
4657 * Verification Tag: Not specified
4658 * Inputs
4659 * (endpoint, asoc, chunk)
4660 *
4661 * Outputs
4662 * (asoc, reply_msg, msg_up, timers, counters)
4663 *
4664 * We simply tag the chunk as a violation. The state machine will log
4665 * the violation and continue.
4666 */
4667enum sctp_disposition sctp_sf_violation(struct net *net,
4668 const struct sctp_endpoint *ep,
4669 const struct sctp_association *asoc,
4670 const union sctp_subtype type,
4671 void *arg,
4672 struct sctp_cmd_seq *commands)
4673{
4674 struct sctp_chunk *chunk = arg;
4675
4676 if (!sctp_vtag_verify(chunk, asoc))
4677 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
4678
4679 /* Make sure that the chunk has a valid length. */
4680 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_chunkhdr)))
4681 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
4682 commands);
4683
4684 return SCTP_DISPOSITION_VIOLATION;
4685}
4686
4687/*
4688 * Common function to handle a protocol violation.
4689 */
4690static enum sctp_disposition sctp_sf_abort_violation(
4691 struct net *net,
4692 const struct sctp_endpoint *ep,
4693 const struct sctp_association *asoc,
4694 void *arg,
4695 struct sctp_cmd_seq *commands,
4696 const __u8 *payload,
4697 const size_t paylen)
4698{
4699 struct sctp_packet *packet = NULL;
4700 struct sctp_chunk *chunk = arg;
4701 struct sctp_chunk *abort = NULL;
4702
4703 /* SCTP-AUTH, Section 6.3:
4704 * It should be noted that if the receiver wants to tear
4705 * down an association in an authenticated way only, the
4706 * handling of malformed packets should not result in
4707 * tearing down the association.
4708 *
4709 * This means that if we only want to abort associations
4710 * in an authenticated way (i.e AUTH+ABORT), then we
4711 * can't destroy this association just because the packet
4712 * was malformed.
4713 */
4714 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
4715 goto discard;
4716
4717 /* Make the abort chunk. */
4718 abort = sctp_make_abort_violation(asoc, chunk, payload, paylen);
4719 if (!abort)
4720 goto nomem;
4721
4722 if (asoc) {
4723 /* Treat INIT-ACK as a special case during COOKIE-WAIT. */
4724 if (chunk->chunk_hdr->type == SCTP_CID_INIT_ACK &&
4725 !asoc->peer.i.init_tag) {
4726 struct sctp_initack_chunk *initack;
4727
4728 initack = (struct sctp_initack_chunk *)chunk->chunk_hdr;
4729 if (!sctp_chunk_length_valid(chunk, sizeof(*initack)))
4730 abort->chunk_hdr->flags |= SCTP_CHUNK_FLAG_T;
4731 else {
4732 unsigned int inittag;
4733
4734 inittag = ntohl(initack->init_hdr.init_tag);
4735 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_INITTAG,
4736 SCTP_U32(inittag));
4737 }
4738 }
4739
4740 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4741 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
4742
4743 if (asoc->state <= SCTP_STATE_COOKIE_ECHOED) {
4744 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4745 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4746 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4747 SCTP_ERROR(ECONNREFUSED));
4748 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
4749 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4750 } else {
4751 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4752 SCTP_ERROR(ECONNABORTED));
4753 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4754 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4755 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
4756 }
4757 } else {
4758 packet = sctp_ootb_pkt_new(net, asoc, chunk);
4759
4760 if (!packet)
4761 goto nomem_pkt;
4762
4763 if (sctp_test_T_bit(abort))
4764 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
4765
4766 abort->skb->sk = ep->base.sk;
4767
4768 sctp_packet_append_chunk(packet, abort);
4769
4770 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
4771 SCTP_PACKET(packet));
4772
4773 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
4774 }
4775
4776 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
4777
4778discard:
4779 sctp_sf_pdiscard(net, ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
4780 return SCTP_DISPOSITION_ABORT;
4781
4782nomem_pkt:
4783 sctp_chunk_free(abort);
4784nomem:
4785 return SCTP_DISPOSITION_NOMEM;
4786}
4787
4788/*
4789 * Handle a protocol violation when the chunk length is invalid.
4790 * "Invalid" length is identified as smaller than the minimal length a
4791 * given chunk can be. For example, a SACK chunk has invalid length
4792 * if its length is set to be smaller than the size of struct sctp_sack_chunk.
4793 *
4794 * We inform the other end by sending an ABORT with a Protocol Violation
4795 * error code.
4796 *
4797 * Section: Not specified
4798 * Verification Tag: Nothing to do
4799 * Inputs
4800 * (endpoint, asoc, chunk)
4801 *
4802 * Outputs
4803 * (reply_msg, msg_up, counters)
4804 *
4805 * Generate an ABORT chunk and terminate the association.
4806 */
4807static enum sctp_disposition sctp_sf_violation_chunklen(
4808 struct net *net,
4809 const struct sctp_endpoint *ep,
4810 const struct sctp_association *asoc,
4811 const union sctp_subtype type,
4812 void *arg,
4813 struct sctp_cmd_seq *commands)
4814{
4815 static const char err_str[] = "The following chunk had invalid length:";
4816
4817 return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str,
4818 sizeof(err_str));
4819}
4820
4821/*
4822 * Handle a protocol violation when the parameter length is invalid.
4823 * If the length is smaller than the minimum length of a given parameter,
4824 * or accumulated length in multi parameters exceeds the end of the chunk,
4825 * the length is considered as invalid.
4826 */
4827static enum sctp_disposition sctp_sf_violation_paramlen(
4828 struct net *net,
4829 const struct sctp_endpoint *ep,
4830 const struct sctp_association *asoc,
4831 const union sctp_subtype type,
4832 void *arg, void *ext,
4833 struct sctp_cmd_seq *commands)
4834{
4835 struct sctp_paramhdr *param = ext;
4836 struct sctp_chunk *abort = NULL;
4837 struct sctp_chunk *chunk = arg;
4838
4839 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
4840 goto discard;
4841
4842 /* Make the abort chunk. */
4843 abort = sctp_make_violation_paramlen(asoc, chunk, param);
4844 if (!abort)
4845 goto nomem;
4846
4847 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4848 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
4849
4850 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4851 SCTP_ERROR(ECONNABORTED));
4852 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4853 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4854 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
4855 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
4856
4857discard:
4858 sctp_sf_pdiscard(net, ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
4859 return SCTP_DISPOSITION_ABORT;
4860nomem:
4861 return SCTP_DISPOSITION_NOMEM;
4862}
4863
4864/* Handle a protocol violation when the peer trying to advance the
4865 * cumulative tsn ack to a point beyond the max tsn currently sent.
4866 *
4867 * We inform the other end by sending an ABORT with a Protocol Violation
4868 * error code.
4869 */
4870static enum sctp_disposition sctp_sf_violation_ctsn(
4871 struct net *net,
4872 const struct sctp_endpoint *ep,
4873 const struct sctp_association *asoc,
4874 const union sctp_subtype type,
4875 void *arg,
4876 struct sctp_cmd_seq *commands)
4877{
4878 static const char err_str[] = "The cumulative tsn ack beyond the max tsn currently sent:";
4879
4880 return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str,
4881 sizeof(err_str));
4882}
4883
4884/* Handle protocol violation of an invalid chunk bundling. For example,
4885 * when we have an association and we receive bundled INIT-ACK, or
4886 * SHUTDOWN-COMPLETE, our peer is clearly violating the "MUST NOT bundle"
4887 * statement from the specs. Additionally, there might be an attacker
4888 * on the path and we may not want to continue this communication.
4889 */
4890static enum sctp_disposition sctp_sf_violation_chunk(
4891 struct net *net,
4892 const struct sctp_endpoint *ep,
4893 const struct sctp_association *asoc,
4894 const union sctp_subtype type,
4895 void *arg,
4896 struct sctp_cmd_seq *commands)
4897{
4898 static const char err_str[] = "The following chunk violates protocol:";
4899
4900 return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str,
4901 sizeof(err_str));
4902}
4903/***************************************************************************
4904 * These are the state functions for handling primitive (Section 10) events.
4905 ***************************************************************************/
4906/*
4907 * sctp_sf_do_prm_asoc
4908 *
4909 * Section: 10.1 ULP-to-SCTP
4910 * B) Associate
4911 *
4912 * Format: ASSOCIATE(local SCTP instance name, destination transport addr,
4913 * outbound stream count)
4914 * -> association id [,destination transport addr list] [,outbound stream
4915 * count]
4916 *
4917 * This primitive allows the upper layer to initiate an association to a
4918 * specific peer endpoint.
4919 *
4920 * The peer endpoint shall be specified by one of the transport addresses
4921 * which defines the endpoint (see Section 1.4). If the local SCTP
4922 * instance has not been initialized, the ASSOCIATE is considered an
4923 * error.
4924 * [This is not relevant for the kernel implementation since we do all
4925 * initialization at boot time. It we hadn't initialized we wouldn't
4926 * get anywhere near this code.]
4927 *
4928 * An association id, which is a local handle to the SCTP association,
4929 * will be returned on successful establishment of the association. If
4930 * SCTP is not able to open an SCTP association with the peer endpoint,
4931 * an error is returned.
4932 * [In the kernel implementation, the struct sctp_association needs to
4933 * be created BEFORE causing this primitive to run.]
4934 *
4935 * Other association parameters may be returned, including the
4936 * complete destination transport addresses of the peer as well as the
4937 * outbound stream count of the local endpoint. One of the transport
4938 * address from the returned destination addresses will be selected by
4939 * the local endpoint as default primary path for sending SCTP packets
4940 * to this peer. The returned "destination transport addr list" can
4941 * be used by the ULP to change the default primary path or to force
4942 * sending a packet to a specific transport address. [All of this
4943 * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING
4944 * function.]
4945 *
4946 * Mandatory attributes:
4947 *
4948 * o local SCTP instance name - obtained from the INITIALIZE operation.
4949 * [This is the argument asoc.]
4950 * o destination transport addr - specified as one of the transport
4951 * addresses of the peer endpoint with which the association is to be
4952 * established.
4953 * [This is asoc->peer.active_path.]
4954 * o outbound stream count - the number of outbound streams the ULP
4955 * would like to open towards this peer endpoint.
4956 * [BUG: This is not currently implemented.]
4957 * Optional attributes:
4958 *
4959 * None.
4960 *
4961 * The return value is a disposition.
4962 */
4963enum sctp_disposition sctp_sf_do_prm_asoc(struct net *net,
4964 const struct sctp_endpoint *ep,
4965 const struct sctp_association *asoc,
4966 const union sctp_subtype type,
4967 void *arg,
4968 struct sctp_cmd_seq *commands)
4969{
4970 struct sctp_association *my_asoc;
4971 struct sctp_chunk *repl;
4972
4973 /* The comment below says that we enter COOKIE-WAIT AFTER
4974 * sending the INIT, but that doesn't actually work in our
4975 * implementation...
4976 */
4977 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4978 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
4979
4980 /* RFC 2960 5.1 Normal Establishment of an Association
4981 *
4982 * A) "A" first sends an INIT chunk to "Z". In the INIT, "A"
4983 * must provide its Verification Tag (Tag_A) in the Initiate
4984 * Tag field. Tag_A SHOULD be a random number in the range of
4985 * 1 to 4294967295 (see 5.3.1 for Tag value selection). ...
4986 */
4987
4988 repl = sctp_make_init(asoc, &asoc->base.bind_addr, GFP_ATOMIC, 0);
4989 if (!repl)
4990 goto nomem;
4991
4992 /* Choose transport for INIT. */
4993 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
4994 SCTP_CHUNK(repl));
4995
4996 /* Cast away the const modifier, as we want to just
4997 * rerun it through as a sideffect.
4998 */
4999 my_asoc = (struct sctp_association *)asoc;
5000 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(my_asoc));
5001
5002 /* After sending the INIT, "A" starts the T1-init timer and
5003 * enters the COOKIE-WAIT state.
5004 */
5005 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
5006 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
5007 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
5008 return SCTP_DISPOSITION_CONSUME;
5009
5010nomem:
5011 return SCTP_DISPOSITION_NOMEM;
5012}
5013
5014/*
5015 * Process the SEND primitive.
5016 *
5017 * Section: 10.1 ULP-to-SCTP
5018 * E) Send
5019 *
5020 * Format: SEND(association id, buffer address, byte count [,context]
5021 * [,stream id] [,life time] [,destination transport address]
5022 * [,unorder flag] [,no-bundle flag] [,payload protocol-id] )
5023 * -> result
5024 *
5025 * This is the main method to send user data via SCTP.
5026 *
5027 * Mandatory attributes:
5028 *
5029 * o association id - local handle to the SCTP association
5030 *
5031 * o buffer address - the location where the user message to be
5032 * transmitted is stored;
5033 *
5034 * o byte count - The size of the user data in number of bytes;
5035 *
5036 * Optional attributes:
5037 *
5038 * o context - an optional 32 bit integer that will be carried in the
5039 * sending failure notification to the ULP if the transportation of
5040 * this User Message fails.
5041 *
5042 * o stream id - to indicate which stream to send the data on. If not
5043 * specified, stream 0 will be used.
5044 *
5045 * o life time - specifies the life time of the user data. The user data
5046 * will not be sent by SCTP after the life time expires. This
5047 * parameter can be used to avoid efforts to transmit stale
5048 * user messages. SCTP notifies the ULP if the data cannot be
5049 * initiated to transport (i.e. sent to the destination via SCTP's
5050 * send primitive) within the life time variable. However, the
5051 * user data will be transmitted if SCTP has attempted to transmit a
5052 * chunk before the life time expired.
5053 *
5054 * o destination transport address - specified as one of the destination
5055 * transport addresses of the peer endpoint to which this packet
5056 * should be sent. Whenever possible, SCTP should use this destination
5057 * transport address for sending the packets, instead of the current
5058 * primary path.
5059 *
5060 * o unorder flag - this flag, if present, indicates that the user
5061 * would like the data delivered in an unordered fashion to the peer
5062 * (i.e., the U flag is set to 1 on all DATA chunks carrying this
5063 * message).
5064 *
5065 * o no-bundle flag - instructs SCTP not to bundle this user data with
5066 * other outbound DATA chunks. SCTP MAY still bundle even when
5067 * this flag is present, when faced with network congestion.
5068 *
5069 * o payload protocol-id - A 32 bit unsigned integer that is to be
5070 * passed to the peer indicating the type of payload protocol data
5071 * being transmitted. This value is passed as opaque data by SCTP.
5072 *
5073 * The return value is the disposition.
5074 */
5075enum sctp_disposition sctp_sf_do_prm_send(struct net *net,
5076 const struct sctp_endpoint *ep,
5077 const struct sctp_association *asoc,
5078 const union sctp_subtype type,
5079 void *arg,
5080 struct sctp_cmd_seq *commands)
5081{
5082 struct sctp_datamsg *msg = arg;
5083
5084 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_MSG, SCTP_DATAMSG(msg));
5085 return SCTP_DISPOSITION_CONSUME;
5086}
5087
5088/*
5089 * Process the SHUTDOWN primitive.
5090 *
5091 * Section: 10.1:
5092 * C) Shutdown
5093 *
5094 * Format: SHUTDOWN(association id)
5095 * -> result
5096 *
5097 * Gracefully closes an association. Any locally queued user data
5098 * will be delivered to the peer. The association will be terminated only
5099 * after the peer acknowledges all the SCTP packets sent. A success code
5100 * will be returned on successful termination of the association. If
5101 * attempting to terminate the association results in a failure, an error
5102 * code shall be returned.
5103 *
5104 * Mandatory attributes:
5105 *
5106 * o association id - local handle to the SCTP association
5107 *
5108 * Optional attributes:
5109 *
5110 * None.
5111 *
5112 * The return value is the disposition.
5113 */
5114enum sctp_disposition sctp_sf_do_9_2_prm_shutdown(
5115 struct net *net,
5116 const struct sctp_endpoint *ep,
5117 const struct sctp_association *asoc,
5118 const union sctp_subtype type,
5119 void *arg,
5120 struct sctp_cmd_seq *commands)
5121{
5122 enum sctp_disposition disposition;
5123
5124 /* From 9.2 Shutdown of an Association
5125 * Upon receipt of the SHUTDOWN primitive from its upper
5126 * layer, the endpoint enters SHUTDOWN-PENDING state and
5127 * remains there until all outstanding data has been
5128 * acknowledged by its peer. The endpoint accepts no new data
5129 * from its upper layer, but retransmits data to the far end
5130 * if necessary to fill gaps.
5131 */
5132 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5133 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
5134
5135 disposition = SCTP_DISPOSITION_CONSUME;
5136 if (sctp_outq_is_empty(&asoc->outqueue)) {
5137 disposition = sctp_sf_do_9_2_start_shutdown(net, ep, asoc, type,
5138 arg, commands);
5139 }
5140
5141 return disposition;
5142}
5143
5144/*
5145 * Process the ABORT primitive.
5146 *
5147 * Section: 10.1:
5148 * C) Abort
5149 *
5150 * Format: Abort(association id [, cause code])
5151 * -> result
5152 *
5153 * Ungracefully closes an association. Any locally queued user data
5154 * will be discarded and an ABORT chunk is sent to the peer. A success code
5155 * will be returned on successful abortion of the association. If
5156 * attempting to abort the association results in a failure, an error
5157 * code shall be returned.
5158 *
5159 * Mandatory attributes:
5160 *
5161 * o association id - local handle to the SCTP association
5162 *
5163 * Optional attributes:
5164 *
5165 * o cause code - reason of the abort to be passed to the peer
5166 *
5167 * None.
5168 *
5169 * The return value is the disposition.
5170 */
5171enum sctp_disposition sctp_sf_do_9_1_prm_abort(
5172 struct net *net,
5173 const struct sctp_endpoint *ep,
5174 const struct sctp_association *asoc,
5175 const union sctp_subtype type,
5176 void *arg,
5177 struct sctp_cmd_seq *commands)
5178{
5179 /* From 9.1 Abort of an Association
5180 * Upon receipt of the ABORT primitive from its upper
5181 * layer, the endpoint enters CLOSED state and
5182 * discard all outstanding data has been
5183 * acknowledged by its peer. The endpoint accepts no new data
5184 * from its upper layer, but retransmits data to the far end
5185 * if necessary to fill gaps.
5186 */
5187 struct sctp_chunk *abort = arg;
5188
5189 if (abort)
5190 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
5191
5192 /* Even if we can't send the ABORT due to low memory delete the
5193 * TCB. This is a departure from our typical NOMEM handling.
5194 */
5195
5196 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5197 SCTP_ERROR(ECONNABORTED));
5198 /* Delete the established association. */
5199 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5200 SCTP_PERR(SCTP_ERROR_USER_ABORT));
5201
5202 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5203 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
5204
5205 return SCTP_DISPOSITION_ABORT;
5206}
5207
5208/* We tried an illegal operation on an association which is closed. */
5209enum sctp_disposition sctp_sf_error_closed(struct net *net,
5210 const struct sctp_endpoint *ep,
5211 const struct sctp_association *asoc,
5212 const union sctp_subtype type,
5213 void *arg,
5214 struct sctp_cmd_seq *commands)
5215{
5216 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, SCTP_ERROR(-EINVAL));
5217 return SCTP_DISPOSITION_CONSUME;
5218}
5219
5220/* We tried an illegal operation on an association which is shutting
5221 * down.
5222 */
5223enum sctp_disposition sctp_sf_error_shutdown(
5224 struct net *net,
5225 const struct sctp_endpoint *ep,
5226 const struct sctp_association *asoc,
5227 const union sctp_subtype type,
5228 void *arg,
5229 struct sctp_cmd_seq *commands)
5230{
5231 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR,
5232 SCTP_ERROR(-ESHUTDOWN));
5233 return SCTP_DISPOSITION_CONSUME;
5234}
5235
5236/*
5237 * sctp_cookie_wait_prm_shutdown
5238 *
5239 * Section: 4 Note: 2
5240 * Verification Tag:
5241 * Inputs
5242 * (endpoint, asoc)
5243 *
5244 * The RFC does not explicitly address this issue, but is the route through the
5245 * state table when someone issues a shutdown while in COOKIE_WAIT state.
5246 *
5247 * Outputs
5248 * (timers)
5249 */
5250enum sctp_disposition sctp_sf_cookie_wait_prm_shutdown(
5251 struct net *net,
5252 const struct sctp_endpoint *ep,
5253 const struct sctp_association *asoc,
5254 const union sctp_subtype type,
5255 void *arg,
5256 struct sctp_cmd_seq *commands)
5257{
5258 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5259 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
5260
5261 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5262 SCTP_STATE(SCTP_STATE_CLOSED));
5263
5264 SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS);
5265
5266 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
5267
5268 return SCTP_DISPOSITION_DELETE_TCB;
5269}
5270
5271/*
5272 * sctp_cookie_echoed_prm_shutdown
5273 *
5274 * Section: 4 Note: 2
5275 * Verification Tag:
5276 * Inputs
5277 * (endpoint, asoc)
5278 *
5279 * The RFC does not explicitly address this issue, but is the route through the
5280 * state table when someone issues a shutdown while in COOKIE_ECHOED state.
5281 *
5282 * Outputs
5283 * (timers)
5284 */
5285enum sctp_disposition sctp_sf_cookie_echoed_prm_shutdown(
5286 struct net *net,
5287 const struct sctp_endpoint *ep,
5288 const struct sctp_association *asoc,
5289 const union sctp_subtype type,
5290 void *arg,
5291 struct sctp_cmd_seq *commands)
5292{
5293 /* There is a single T1 timer, so we should be able to use
5294 * common function with the COOKIE-WAIT state.
5295 */
5296 return sctp_sf_cookie_wait_prm_shutdown(net, ep, asoc, type, arg, commands);
5297}
5298
5299/*
5300 * sctp_sf_cookie_wait_prm_abort
5301 *
5302 * Section: 4 Note: 2
5303 * Verification Tag:
5304 * Inputs
5305 * (endpoint, asoc)
5306 *
5307 * The RFC does not explicitly address this issue, but is the route through the
5308 * state table when someone issues an abort while in COOKIE_WAIT state.
5309 *
5310 * Outputs
5311 * (timers)
5312 */
5313enum sctp_disposition sctp_sf_cookie_wait_prm_abort(
5314 struct net *net,
5315 const struct sctp_endpoint *ep,
5316 const struct sctp_association *asoc,
5317 const union sctp_subtype type,
5318 void *arg,
5319 struct sctp_cmd_seq *commands)
5320{
5321 struct sctp_chunk *abort = arg;
5322
5323 /* Stop T1-init timer */
5324 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5325 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
5326
5327 if (abort)
5328 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
5329
5330 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5331 SCTP_STATE(SCTP_STATE_CLOSED));
5332
5333 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5334
5335 /* Even if we can't send the ABORT due to low memory delete the
5336 * TCB. This is a departure from our typical NOMEM handling.
5337 */
5338
5339 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5340 SCTP_ERROR(ECONNREFUSED));
5341 /* Delete the established association. */
5342 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
5343 SCTP_PERR(SCTP_ERROR_USER_ABORT));
5344
5345 return SCTP_DISPOSITION_ABORT;
5346}
5347
5348/*
5349 * sctp_sf_cookie_echoed_prm_abort
5350 *
5351 * Section: 4 Note: 3
5352 * Verification Tag:
5353 * Inputs
5354 * (endpoint, asoc)
5355 *
5356 * The RFC does not explcitly address this issue, but is the route through the
5357 * state table when someone issues an abort while in COOKIE_ECHOED state.
5358 *
5359 * Outputs
5360 * (timers)
5361 */
5362enum sctp_disposition sctp_sf_cookie_echoed_prm_abort(
5363 struct net *net,
5364 const struct sctp_endpoint *ep,
5365 const struct sctp_association *asoc,
5366 const union sctp_subtype type,
5367 void *arg,
5368 struct sctp_cmd_seq *commands)
5369{
5370 /* There is a single T1 timer, so we should be able to use
5371 * common function with the COOKIE-WAIT state.
5372 */
5373 return sctp_sf_cookie_wait_prm_abort(net, ep, asoc, type, arg, commands);
5374}
5375
5376/*
5377 * sctp_sf_shutdown_pending_prm_abort
5378 *
5379 * Inputs
5380 * (endpoint, asoc)
5381 *
5382 * The RFC does not explicitly address this issue, but is the route through the
5383 * state table when someone issues an abort while in SHUTDOWN-PENDING state.
5384 *
5385 * Outputs
5386 * (timers)
5387 */
5388enum sctp_disposition sctp_sf_shutdown_pending_prm_abort(
5389 struct net *net,
5390 const struct sctp_endpoint *ep,
5391 const struct sctp_association *asoc,
5392 const union sctp_subtype type,
5393 void *arg,
5394 struct sctp_cmd_seq *commands)
5395{
5396 /* Stop the T5-shutdown guard timer. */
5397 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5398 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5399
5400 return sctp_sf_do_9_1_prm_abort(net, ep, asoc, type, arg, commands);
5401}
5402
5403/*
5404 * sctp_sf_shutdown_sent_prm_abort
5405 *
5406 * Inputs
5407 * (endpoint, asoc)
5408 *
5409 * The RFC does not explicitly address this issue, but is the route through the
5410 * state table when someone issues an abort while in SHUTDOWN-SENT state.
5411 *
5412 * Outputs
5413 * (timers)
5414 */
5415enum sctp_disposition sctp_sf_shutdown_sent_prm_abort(
5416 struct net *net,
5417 const struct sctp_endpoint *ep,
5418 const struct sctp_association *asoc,
5419 const union sctp_subtype type,
5420 void *arg,
5421 struct sctp_cmd_seq *commands)
5422{
5423 /* Stop the T2-shutdown timer. */
5424 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5425 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5426
5427 /* Stop the T5-shutdown guard timer. */
5428 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5429 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5430
5431 return sctp_sf_do_9_1_prm_abort(net, ep, asoc, type, arg, commands);
5432}
5433
5434/*
5435 * sctp_sf_cookie_echoed_prm_abort
5436 *
5437 * Inputs
5438 * (endpoint, asoc)
5439 *
5440 * The RFC does not explcitly address this issue, but is the route through the
5441 * state table when someone issues an abort while in COOKIE_ECHOED state.
5442 *
5443 * Outputs
5444 * (timers)
5445 */
5446enum sctp_disposition sctp_sf_shutdown_ack_sent_prm_abort(
5447 struct net *net,
5448 const struct sctp_endpoint *ep,
5449 const struct sctp_association *asoc,
5450 const union sctp_subtype type,
5451 void *arg,
5452 struct sctp_cmd_seq *commands)
5453{
5454 /* The same T2 timer, so we should be able to use
5455 * common function with the SHUTDOWN-SENT state.
5456 */
5457 return sctp_sf_shutdown_sent_prm_abort(net, ep, asoc, type, arg, commands);
5458}
5459
5460/*
5461 * Process the REQUESTHEARTBEAT primitive
5462 *
5463 * 10.1 ULP-to-SCTP
5464 * J) Request Heartbeat
5465 *
5466 * Format: REQUESTHEARTBEAT(association id, destination transport address)
5467 *
5468 * -> result
5469 *
5470 * Instructs the local endpoint to perform a HeartBeat on the specified
5471 * destination transport address of the given association. The returned
5472 * result should indicate whether the transmission of the HEARTBEAT
5473 * chunk to the destination address is successful.
5474 *
5475 * Mandatory attributes:
5476 *
5477 * o association id - local handle to the SCTP association
5478 *
5479 * o destination transport address - the transport address of the
5480 * association on which a heartbeat should be issued.
5481 */
5482enum sctp_disposition sctp_sf_do_prm_requestheartbeat(
5483 struct net *net,
5484 const struct sctp_endpoint *ep,
5485 const struct sctp_association *asoc,
5486 const union sctp_subtype type,
5487 void *arg,
5488 struct sctp_cmd_seq *commands)
5489{
5490 if (SCTP_DISPOSITION_NOMEM == sctp_sf_heartbeat(ep, asoc, type,
5491 (struct sctp_transport *)arg, commands))
5492 return SCTP_DISPOSITION_NOMEM;
5493
5494 /*
5495 * RFC 2960 (bis), section 8.3
5496 *
5497 * D) Request an on-demand HEARTBEAT on a specific destination
5498 * transport address of a given association.
5499 *
5500 * The endpoint should increment the respective error counter of
5501 * the destination transport address each time a HEARTBEAT is sent
5502 * to that address and not acknowledged within one RTO.
5503 *
5504 */
5505 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_HB_SENT,
5506 SCTP_TRANSPORT(arg));
5507 return SCTP_DISPOSITION_CONSUME;
5508}
5509
5510/*
5511 * ADDIP Section 4.1 ASCONF Chunk Procedures
5512 * When an endpoint has an ASCONF signaled change to be sent to the
5513 * remote endpoint it should do A1 to A9
5514 */
5515enum sctp_disposition sctp_sf_do_prm_asconf(struct net *net,
5516 const struct sctp_endpoint *ep,
5517 const struct sctp_association *asoc,
5518 const union sctp_subtype type,
5519 void *arg,
5520 struct sctp_cmd_seq *commands)
5521{
5522 struct sctp_chunk *chunk = arg;
5523
5524 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
5525 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
5526 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
5527 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
5528 return SCTP_DISPOSITION_CONSUME;
5529}
5530
5531/* RE-CONFIG Section 5.1 RECONF Chunk Procedures */
5532enum sctp_disposition sctp_sf_do_prm_reconf(struct net *net,
5533 const struct sctp_endpoint *ep,
5534 const struct sctp_association *asoc,
5535 const union sctp_subtype type,
5536 void *arg,
5537 struct sctp_cmd_seq *commands)
5538{
5539 struct sctp_chunk *chunk = arg;
5540
5541 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
5542 return SCTP_DISPOSITION_CONSUME;
5543}
5544
5545/*
5546 * Ignore the primitive event
5547 *
5548 * The return value is the disposition of the primitive.
5549 */
5550enum sctp_disposition sctp_sf_ignore_primitive(
5551 struct net *net,
5552 const struct sctp_endpoint *ep,
5553 const struct sctp_association *asoc,
5554 const union sctp_subtype type,
5555 void *arg,
5556 struct sctp_cmd_seq *commands)
5557{
5558 pr_debug("%s: primitive type:%d is ignored\n", __func__,
5559 type.primitive);
5560
5561 return SCTP_DISPOSITION_DISCARD;
5562}
5563
5564/***************************************************************************
5565 * These are the state functions for the OTHER events.
5566 ***************************************************************************/
5567
5568/*
5569 * When the SCTP stack has no more user data to send or retransmit, this
5570 * notification is given to the user. Also, at the time when a user app
5571 * subscribes to this event, if there is no data to be sent or
5572 * retransmit, the stack will immediately send up this notification.
5573 */
5574enum sctp_disposition sctp_sf_do_no_pending_tsn(
5575 struct net *net,
5576 const struct sctp_endpoint *ep,
5577 const struct sctp_association *asoc,
5578 const union sctp_subtype type,
5579 void *arg,
5580 struct sctp_cmd_seq *commands)
5581{
5582 struct sctp_ulpevent *event;
5583
5584 event = sctp_ulpevent_make_sender_dry_event(asoc, GFP_ATOMIC);
5585 if (!event)
5586 return SCTP_DISPOSITION_NOMEM;
5587
5588 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(event));
5589
5590 return SCTP_DISPOSITION_CONSUME;
5591}
5592
5593/*
5594 * Start the shutdown negotiation.
5595 *
5596 * From Section 9.2:
5597 * Once all its outstanding data has been acknowledged, the endpoint
5598 * shall send a SHUTDOWN chunk to its peer including in the Cumulative
5599 * TSN Ack field the last sequential TSN it has received from the peer.
5600 * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT
5601 * state. If the timer expires, the endpoint must re-send the SHUTDOWN
5602 * with the updated last sequential TSN received from its peer.
5603 *
5604 * The return value is the disposition.
5605 */
5606enum sctp_disposition sctp_sf_do_9_2_start_shutdown(
5607 struct net *net,
5608 const struct sctp_endpoint *ep,
5609 const struct sctp_association *asoc,
5610 const union sctp_subtype type,
5611 void *arg,
5612 struct sctp_cmd_seq *commands)
5613{
5614 struct sctp_chunk *reply;
5615
5616 /* Once all its outstanding data has been acknowledged, the
5617 * endpoint shall send a SHUTDOWN chunk to its peer including
5618 * in the Cumulative TSN Ack field the last sequential TSN it
5619 * has received from the peer.
5620 */
5621 reply = sctp_make_shutdown(asoc, arg);
5622 if (!reply)
5623 goto nomem;
5624
5625 /* Set the transport for the SHUTDOWN chunk and the timeout for the
5626 * T2-shutdown timer.
5627 */
5628 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5629
5630 /* It shall then start the T2-shutdown timer */
5631 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
5632 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5633
5634 /* RFC 4960 Section 9.2
5635 * The sender of the SHUTDOWN MAY also start an overall guard timer
5636 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5637 */
5638 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5639 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5640
5641 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
5642 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5643 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
5644
5645 /* and enter the SHUTDOWN-SENT state. */
5646 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5647 SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT));
5648
5649 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5650 *
5651 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
5652 * or SHUTDOWN-ACK.
5653 */
5654 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
5655
5656 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5657
5658 return SCTP_DISPOSITION_CONSUME;
5659
5660nomem:
5661 return SCTP_DISPOSITION_NOMEM;
5662}
5663
5664/*
5665 * Generate a SHUTDOWN ACK now that everything is SACK'd.
5666 *
5667 * From Section 9.2:
5668 *
5669 * If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5670 * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own,
5671 * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the
5672 * endpoint must re-send the SHUTDOWN ACK.
5673 *
5674 * The return value is the disposition.
5675 */
5676enum sctp_disposition sctp_sf_do_9_2_shutdown_ack(
5677 struct net *net,
5678 const struct sctp_endpoint *ep,
5679 const struct sctp_association *asoc,
5680 const union sctp_subtype type,
5681 void *arg,
5682 struct sctp_cmd_seq *commands)
5683{
5684 struct sctp_chunk *chunk = arg;
5685 struct sctp_chunk *reply;
5686
5687 /* There are 2 ways of getting here:
5688 * 1) called in response to a SHUTDOWN chunk
5689 * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued.
5690 *
5691 * For the case (2), the arg parameter is set to NULL. We need
5692 * to check that we have a chunk before accessing it's fields.
5693 */
5694 if (chunk) {
5695 if (!sctp_vtag_verify(chunk, asoc))
5696 return sctp_sf_pdiscard(net, ep, asoc, type, arg,
5697 commands);
5698
5699 /* Make sure that the SHUTDOWN chunk has a valid length. */
5700 if (!sctp_chunk_length_valid(
5701 chunk, sizeof(struct sctp_shutdown_chunk)))
5702 return sctp_sf_violation_chunklen(net, ep, asoc, type,
5703 arg, commands);
5704 }
5705
5706 /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5707 * shall send a SHUTDOWN ACK ...
5708 */
5709 reply = sctp_make_shutdown_ack(asoc, chunk);
5710 if (!reply)
5711 goto nomem;
5712
5713 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
5714 * the T2-shutdown timer.
5715 */
5716 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5717
5718 /* and start/restart a T2-shutdown timer of its own, */
5719 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5720 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5721
5722 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
5723 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5724 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
5725
5726 /* Enter the SHUTDOWN-ACK-SENT state. */
5727 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5728 SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT));
5729
5730 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5731 *
5732 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
5733 * or SHUTDOWN-ACK.
5734 */
5735 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
5736
5737 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5738
5739 return SCTP_DISPOSITION_CONSUME;
5740
5741nomem:
5742 return SCTP_DISPOSITION_NOMEM;
5743}
5744
5745/*
5746 * Ignore the event defined as other
5747 *
5748 * The return value is the disposition of the event.
5749 */
5750enum sctp_disposition sctp_sf_ignore_other(struct net *net,
5751 const struct sctp_endpoint *ep,
5752 const struct sctp_association *asoc,
5753 const union sctp_subtype type,
5754 void *arg,
5755 struct sctp_cmd_seq *commands)
5756{
5757 pr_debug("%s: the event other type:%d is ignored\n",
5758 __func__, type.other);
5759
5760 return SCTP_DISPOSITION_DISCARD;
5761}
5762
5763/************************************************************
5764 * These are the state functions for handling timeout events.
5765 ************************************************************/
5766
5767/*
5768 * RTX Timeout
5769 *
5770 * Section: 6.3.3 Handle T3-rtx Expiration
5771 *
5772 * Whenever the retransmission timer T3-rtx expires for a destination
5773 * address, do the following:
5774 * [See below]
5775 *
5776 * The return value is the disposition of the chunk.
5777 */
5778enum sctp_disposition sctp_sf_do_6_3_3_rtx(struct net *net,
5779 const struct sctp_endpoint *ep,
5780 const struct sctp_association *asoc,
5781 const union sctp_subtype type,
5782 void *arg,
5783 struct sctp_cmd_seq *commands)
5784{
5785 struct sctp_transport *transport = arg;
5786
5787 SCTP_INC_STATS(net, SCTP_MIB_T3_RTX_EXPIREDS);
5788
5789 if (asoc->overall_error_count >= asoc->max_retrans) {
5790 if (asoc->peer.zero_window_announced &&
5791 asoc->state == SCTP_STATE_SHUTDOWN_PENDING) {
5792 /*
5793 * We are here likely because the receiver had its rwnd
5794 * closed for a while and we have not been able to
5795 * transmit the locally queued data within the maximum
5796 * retransmission attempts limit. Start the T5
5797 * shutdown guard timer to give the receiver one last
5798 * chance and some additional time to recover before
5799 * aborting.
5800 */
5801 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START_ONCE,
5802 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5803 } else {
5804 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5805 SCTP_ERROR(ETIMEDOUT));
5806 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5807 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5808 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5809 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5810 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
5811 return SCTP_DISPOSITION_DELETE_TCB;
5812 }
5813 }
5814
5815 /* E1) For the destination address for which the timer
5816 * expires, adjust its ssthresh with rules defined in Section
5817 * 7.2.3 and set the cwnd <- MTU.
5818 */
5819
5820 /* E2) For the destination address for which the timer
5821 * expires, set RTO <- RTO * 2 ("back off the timer"). The
5822 * maximum value discussed in rule C7 above (RTO.max) may be
5823 * used to provide an upper bound to this doubling operation.
5824 */
5825
5826 /* E3) Determine how many of the earliest (i.e., lowest TSN)
5827 * outstanding DATA chunks for the address for which the
5828 * T3-rtx has expired will fit into a single packet, subject
5829 * to the MTU constraint for the path corresponding to the
5830 * destination transport address to which the retransmission
5831 * is being sent (this may be different from the address for
5832 * which the timer expires [see Section 6.4]). Call this
5833 * value K. Bundle and retransmit those K DATA chunks in a
5834 * single packet to the destination endpoint.
5835 *
5836 * Note: Any DATA chunks that were sent to the address for
5837 * which the T3-rtx timer expired but did not fit in one MTU
5838 * (rule E3 above), should be marked for retransmission and
5839 * sent as soon as cwnd allows (normally when a SACK arrives).
5840 */
5841
5842 /* Do some failure management (Section 8.2). */
5843 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
5844
5845 /* NB: Rules E4 and F1 are implicit in R1. */
5846 sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN, SCTP_TRANSPORT(transport));
5847
5848 return SCTP_DISPOSITION_CONSUME;
5849}
5850
5851/*
5852 * Generate delayed SACK on timeout
5853 *
5854 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
5855 *
5856 * The guidelines on delayed acknowledgement algorithm specified in
5857 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
5858 * acknowledgement SHOULD be generated for at least every second packet
5859 * (not every second DATA chunk) received, and SHOULD be generated
5860 * within 200 ms of the arrival of any unacknowledged DATA chunk. In
5861 * some situations it may be beneficial for an SCTP transmitter to be
5862 * more conservative than the algorithms detailed in this document
5863 * allow. However, an SCTP transmitter MUST NOT be more aggressive than
5864 * the following algorithms allow.
5865 */
5866enum sctp_disposition sctp_sf_do_6_2_sack(struct net *net,
5867 const struct sctp_endpoint *ep,
5868 const struct sctp_association *asoc,
5869 const union sctp_subtype type,
5870 void *arg,
5871 struct sctp_cmd_seq *commands)
5872{
5873 SCTP_INC_STATS(net, SCTP_MIB_DELAY_SACK_EXPIREDS);
5874 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
5875 return SCTP_DISPOSITION_CONSUME;
5876}
5877
5878/*
5879 * sctp_sf_t1_init_timer_expire
5880 *
5881 * Section: 4 Note: 2
5882 * Verification Tag:
5883 * Inputs
5884 * (endpoint, asoc)
5885 *
5886 * RFC 2960 Section 4 Notes
5887 * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT
5888 * and re-start the T1-init timer without changing state. This MUST
5889 * be repeated up to 'Max.Init.Retransmits' times. After that, the
5890 * endpoint MUST abort the initialization process and report the
5891 * error to SCTP user.
5892 *
5893 * Outputs
5894 * (timers, events)
5895 *
5896 */
5897enum sctp_disposition sctp_sf_t1_init_timer_expire(
5898 struct net *net,
5899 const struct sctp_endpoint *ep,
5900 const struct sctp_association *asoc,
5901 const union sctp_subtype type,
5902 void *arg,
5903 struct sctp_cmd_seq *commands)
5904{
5905 int attempts = asoc->init_err_counter + 1;
5906 struct sctp_chunk *repl = NULL;
5907 struct sctp_bind_addr *bp;
5908
5909 pr_debug("%s: timer T1 expired (INIT)\n", __func__);
5910
5911 SCTP_INC_STATS(net, SCTP_MIB_T1_INIT_EXPIREDS);
5912
5913 if (attempts <= asoc->max_init_attempts) {
5914 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
5915 repl = sctp_make_init(asoc, bp, GFP_ATOMIC, 0);
5916 if (!repl)
5917 return SCTP_DISPOSITION_NOMEM;
5918
5919 /* Choose transport for INIT. */
5920 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
5921 SCTP_CHUNK(repl));
5922
5923 /* Issue a sideeffect to do the needed accounting. */
5924 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_RESTART,
5925 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
5926
5927 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
5928 } else {
5929 pr_debug("%s: giving up on INIT, attempts:%d "
5930 "max_init_attempts:%d\n", __func__, attempts,
5931 asoc->max_init_attempts);
5932
5933 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5934 SCTP_ERROR(ETIMEDOUT));
5935 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
5936 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5937 return SCTP_DISPOSITION_DELETE_TCB;
5938 }
5939
5940 return SCTP_DISPOSITION_CONSUME;
5941}
5942
5943/*
5944 * sctp_sf_t1_cookie_timer_expire
5945 *
5946 * Section: 4 Note: 2
5947 * Verification Tag:
5948 * Inputs
5949 * (endpoint, asoc)
5950 *
5951 * RFC 2960 Section 4 Notes
5952 * 3) If the T1-cookie timer expires, the endpoint MUST retransmit
5953 * COOKIE ECHO and re-start the T1-cookie timer without changing
5954 * state. This MUST be repeated up to 'Max.Init.Retransmits' times.
5955 * After that, the endpoint MUST abort the initialization process and
5956 * report the error to SCTP user.
5957 *
5958 * Outputs
5959 * (timers, events)
5960 *
5961 */
5962enum sctp_disposition sctp_sf_t1_cookie_timer_expire(
5963 struct net *net,
5964 const struct sctp_endpoint *ep,
5965 const struct sctp_association *asoc,
5966 const union sctp_subtype type,
5967 void *arg,
5968 struct sctp_cmd_seq *commands)
5969{
5970 int attempts = asoc->init_err_counter + 1;
5971 struct sctp_chunk *repl = NULL;
5972
5973 pr_debug("%s: timer T1 expired (COOKIE-ECHO)\n", __func__);
5974
5975 SCTP_INC_STATS(net, SCTP_MIB_T1_COOKIE_EXPIREDS);
5976
5977 if (attempts <= asoc->max_init_attempts) {
5978 repl = sctp_make_cookie_echo(asoc, NULL);
5979 if (!repl)
5980 return SCTP_DISPOSITION_NOMEM;
5981
5982 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
5983 SCTP_CHUNK(repl));
5984 /* Issue a sideeffect to do the needed accounting. */
5985 sctp_add_cmd_sf(commands, SCTP_CMD_COOKIEECHO_RESTART,
5986 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
5987
5988 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
5989 } else {
5990 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5991 SCTP_ERROR(ETIMEDOUT));
5992 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
5993 SCTP_PERR(SCTP_ERROR_NO_ERROR));
5994 return SCTP_DISPOSITION_DELETE_TCB;
5995 }
5996
5997 return SCTP_DISPOSITION_CONSUME;
5998}
5999
6000/* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN
6001 * with the updated last sequential TSN received from its peer.
6002 *
6003 * An endpoint should limit the number of retransmission of the
6004 * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'.
6005 * If this threshold is exceeded the endpoint should destroy the TCB and
6006 * MUST report the peer endpoint unreachable to the upper layer (and
6007 * thus the association enters the CLOSED state). The reception of any
6008 * packet from its peer (i.e. as the peer sends all of its queued DATA
6009 * chunks) should clear the endpoint's retransmission count and restart
6010 * the T2-Shutdown timer, giving its peer ample opportunity to transmit
6011 * all of its queued DATA chunks that have not yet been sent.
6012 */
6013enum sctp_disposition sctp_sf_t2_timer_expire(
6014 struct net *net,
6015 const struct sctp_endpoint *ep,
6016 const struct sctp_association *asoc,
6017 const union sctp_subtype type,
6018 void *arg,
6019 struct sctp_cmd_seq *commands)
6020{
6021 struct sctp_chunk *reply = NULL;
6022
6023 pr_debug("%s: timer T2 expired\n", __func__);
6024
6025 SCTP_INC_STATS(net, SCTP_MIB_T2_SHUTDOWN_EXPIREDS);
6026
6027 ((struct sctp_association *)asoc)->shutdown_retries++;
6028
6029 if (asoc->overall_error_count >= asoc->max_retrans) {
6030 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
6031 SCTP_ERROR(ETIMEDOUT));
6032 /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
6033 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
6034 SCTP_PERR(SCTP_ERROR_NO_ERROR));
6035 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
6036 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
6037 return SCTP_DISPOSITION_DELETE_TCB;
6038 }
6039
6040 switch (asoc->state) {
6041 case SCTP_STATE_SHUTDOWN_SENT:
6042 reply = sctp_make_shutdown(asoc, NULL);
6043 break;
6044
6045 case SCTP_STATE_SHUTDOWN_ACK_SENT:
6046 reply = sctp_make_shutdown_ack(asoc, NULL);
6047 break;
6048
6049 default:
6050 BUG();
6051 break;
6052 }
6053
6054 if (!reply)
6055 goto nomem;
6056
6057 /* Do some failure management (Section 8.2).
6058 * If we remove the transport an SHUTDOWN was last sent to, don't
6059 * do failure management.
6060 */
6061 if (asoc->shutdown_last_sent_to)
6062 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
6063 SCTP_TRANSPORT(asoc->shutdown_last_sent_to));
6064
6065 /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for
6066 * the T2-shutdown timer.
6067 */
6068 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
6069
6070 /* Restart the T2-shutdown timer. */
6071 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
6072 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
6073 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
6074 return SCTP_DISPOSITION_CONSUME;
6075
6076nomem:
6077 return SCTP_DISPOSITION_NOMEM;
6078}
6079
6080/*
6081 * ADDIP Section 4.1 ASCONF Chunk Procedures
6082 * If the T4 RTO timer expires the endpoint should do B1 to B5
6083 */
6084enum sctp_disposition sctp_sf_t4_timer_expire(
6085 struct net *net,
6086 const struct sctp_endpoint *ep,
6087 const struct sctp_association *asoc,
6088 const union sctp_subtype type,
6089 void *arg,
6090 struct sctp_cmd_seq *commands)
6091{
6092 struct sctp_chunk *chunk = asoc->addip_last_asconf;
6093 struct sctp_transport *transport = chunk->transport;
6094
6095 SCTP_INC_STATS(net, SCTP_MIB_T4_RTO_EXPIREDS);
6096
6097 /* ADDIP 4.1 B1) Increment the error counters and perform path failure
6098 * detection on the appropriate destination address as defined in
6099 * RFC2960 [5] section 8.1 and 8.2.
6100 */
6101 if (transport)
6102 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
6103 SCTP_TRANSPORT(transport));
6104
6105 /* Reconfig T4 timer and transport. */
6106 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
6107
6108 /* ADDIP 4.1 B2) Increment the association error counters and perform
6109 * endpoint failure detection on the association as defined in
6110 * RFC2960 [5] section 8.1 and 8.2.
6111 * association error counter is incremented in SCTP_CMD_STRIKE.
6112 */
6113 if (asoc->overall_error_count >= asoc->max_retrans) {
6114 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
6115 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
6116 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
6117 SCTP_ERROR(ETIMEDOUT));
6118 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
6119 SCTP_PERR(SCTP_ERROR_NO_ERROR));
6120 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
6121 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
6122 return SCTP_DISPOSITION_ABORT;
6123 }
6124
6125 /* ADDIP 4.1 B3) Back-off the destination address RTO value to which
6126 * the ASCONF chunk was sent by doubling the RTO timer value.
6127 * This is done in SCTP_CMD_STRIKE.
6128 */
6129
6130 /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible
6131 * choose an alternate destination address (please refer to RFC2960
6132 * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this
6133 * chunk, it MUST be the same (including its serial number) as the last
6134 * ASCONF sent.
6135 */
6136 sctp_chunk_hold(asoc->addip_last_asconf);
6137 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
6138 SCTP_CHUNK(asoc->addip_last_asconf));
6139
6140 /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different
6141 * destination is selected, then the RTO used will be that of the new
6142 * destination address.
6143 */
6144 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
6145 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
6146
6147 return SCTP_DISPOSITION_CONSUME;
6148}
6149
6150/* sctpimpguide-05 Section 2.12.2
6151 * The sender of the SHUTDOWN MAY also start an overall guard timer
6152 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
6153 * At the expiration of this timer the sender SHOULD abort the association
6154 * by sending an ABORT chunk.
6155 */
6156enum sctp_disposition sctp_sf_t5_timer_expire(
6157 struct net *net,
6158 const struct sctp_endpoint *ep,
6159 const struct sctp_association *asoc,
6160 const union sctp_subtype type,
6161 void *arg,
6162 struct sctp_cmd_seq *commands)
6163{
6164 struct sctp_chunk *reply = NULL;
6165
6166 pr_debug("%s: timer T5 expired\n", __func__);
6167
6168 SCTP_INC_STATS(net, SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS);
6169
6170 reply = sctp_make_abort(asoc, NULL, 0);
6171 if (!reply)
6172 goto nomem;
6173
6174 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
6175 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
6176 SCTP_ERROR(ETIMEDOUT));
6177 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
6178 SCTP_PERR(SCTP_ERROR_NO_ERROR));
6179
6180 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
6181 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
6182
6183 return SCTP_DISPOSITION_DELETE_TCB;
6184nomem:
6185 return SCTP_DISPOSITION_NOMEM;
6186}
6187
6188/* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires,
6189 * the association is automatically closed by starting the shutdown process.
6190 * The work that needs to be done is same as when SHUTDOWN is initiated by
6191 * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown().
6192 */
6193enum sctp_disposition sctp_sf_autoclose_timer_expire(
6194 struct net *net,
6195 const struct sctp_endpoint *ep,
6196 const struct sctp_association *asoc,
6197 const union sctp_subtype type,
6198 void *arg,
6199 struct sctp_cmd_seq *commands)
6200{
6201 enum sctp_disposition disposition;
6202
6203 SCTP_INC_STATS(net, SCTP_MIB_AUTOCLOSE_EXPIREDS);
6204
6205 /* From 9.2 Shutdown of an Association
6206 * Upon receipt of the SHUTDOWN primitive from its upper
6207 * layer, the endpoint enters SHUTDOWN-PENDING state and
6208 * remains there until all outstanding data has been
6209 * acknowledged by its peer. The endpoint accepts no new data
6210 * from its upper layer, but retransmits data to the far end
6211 * if necessary to fill gaps.
6212 */
6213 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
6214 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
6215
6216 disposition = SCTP_DISPOSITION_CONSUME;
6217 if (sctp_outq_is_empty(&asoc->outqueue)) {
6218 disposition = sctp_sf_do_9_2_start_shutdown(net, ep, asoc, type,
6219 NULL, commands);
6220 }
6221
6222 return disposition;
6223}
6224
6225/*****************************************************************************
6226 * These are sa state functions which could apply to all types of events.
6227 ****************************************************************************/
6228
6229/*
6230 * This table entry is not implemented.
6231 *
6232 * Inputs
6233 * (endpoint, asoc, chunk)
6234 *
6235 * The return value is the disposition of the chunk.
6236 */
6237enum sctp_disposition sctp_sf_not_impl(struct net *net,
6238 const struct sctp_endpoint *ep,
6239 const struct sctp_association *asoc,
6240 const union sctp_subtype type,
6241 void *arg, struct sctp_cmd_seq *commands)
6242{
6243 return SCTP_DISPOSITION_NOT_IMPL;
6244}
6245
6246/*
6247 * This table entry represents a bug.
6248 *
6249 * Inputs
6250 * (endpoint, asoc, chunk)
6251 *
6252 * The return value is the disposition of the chunk.
6253 */
6254enum sctp_disposition sctp_sf_bug(struct net *net,
6255 const struct sctp_endpoint *ep,
6256 const struct sctp_association *asoc,
6257 const union sctp_subtype type,
6258 void *arg, struct sctp_cmd_seq *commands)
6259{
6260 return SCTP_DISPOSITION_BUG;
6261}
6262
6263/*
6264 * This table entry represents the firing of a timer in the wrong state.
6265 * Since timer deletion cannot be guaranteed a timer 'may' end up firing
6266 * when the association is in the wrong state. This event should
6267 * be ignored, so as to prevent any rearming of the timer.
6268 *
6269 * Inputs
6270 * (endpoint, asoc, chunk)
6271 *
6272 * The return value is the disposition of the chunk.
6273 */
6274enum sctp_disposition sctp_sf_timer_ignore(struct net *net,
6275 const struct sctp_endpoint *ep,
6276 const struct sctp_association *asoc,
6277 const union sctp_subtype type,
6278 void *arg,
6279 struct sctp_cmd_seq *commands)
6280{
6281 pr_debug("%s: timer %d ignored\n", __func__, type.chunk);
6282
6283 return SCTP_DISPOSITION_CONSUME;
6284}
6285
6286/********************************************************************
6287 * 2nd Level Abstractions
6288 ********************************************************************/
6289
6290/* Pull the SACK chunk based on the SACK header. */
6291static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk)
6292{
6293 struct sctp_sackhdr *sack;
6294 __u16 num_dup_tsns;
6295 unsigned int len;
6296 __u16 num_blocks;
6297
6298 /* Protect ourselves from reading too far into
6299 * the skb from a bogus sender.
6300 */
6301 sack = (struct sctp_sackhdr *) chunk->skb->data;
6302
6303 num_blocks = ntohs(sack->num_gap_ack_blocks);
6304 num_dup_tsns = ntohs(sack->num_dup_tsns);
6305 len = sizeof(struct sctp_sackhdr);
6306 len += (num_blocks + num_dup_tsns) * sizeof(__u32);
6307 if (len > chunk->skb->len)
6308 return NULL;
6309
6310 skb_pull(chunk->skb, len);
6311
6312 return sack;
6313}
6314
6315/* Create an ABORT packet to be sent as a response, with the specified
6316 * error causes.
6317 */
6318static struct sctp_packet *sctp_abort_pkt_new(
6319 struct net *net,
6320 const struct sctp_endpoint *ep,
6321 const struct sctp_association *asoc,
6322 struct sctp_chunk *chunk,
6323 const void *payload, size_t paylen)
6324{
6325 struct sctp_packet *packet;
6326 struct sctp_chunk *abort;
6327
6328 packet = sctp_ootb_pkt_new(net, asoc, chunk);
6329
6330 if (packet) {
6331 /* Make an ABORT.
6332 * The T bit will be set if the asoc is NULL.
6333 */
6334 abort = sctp_make_abort(asoc, chunk, paylen);
6335 if (!abort) {
6336 sctp_ootb_pkt_free(packet);
6337 return NULL;
6338 }
6339
6340 /* Reflect vtag if T-Bit is set */
6341 if (sctp_test_T_bit(abort))
6342 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
6343
6344 /* Add specified error causes, i.e., payload, to the
6345 * end of the chunk.
6346 */
6347 sctp_addto_chunk(abort, paylen, payload);
6348
6349 /* Set the skb to the belonging sock for accounting. */
6350 abort->skb->sk = ep->base.sk;
6351
6352 sctp_packet_append_chunk(packet, abort);
6353
6354 }
6355
6356 return packet;
6357}
6358
6359/* Allocate a packet for responding in the OOTB conditions. */
6360static struct sctp_packet *sctp_ootb_pkt_new(
6361 struct net *net,
6362 const struct sctp_association *asoc,
6363 const struct sctp_chunk *chunk)
6364{
6365 struct sctp_transport *transport;
6366 struct sctp_packet *packet;
6367 __u16 sport, dport;
6368 __u32 vtag;
6369
6370 /* Get the source and destination port from the inbound packet. */
6371 sport = ntohs(chunk->sctp_hdr->dest);
6372 dport = ntohs(chunk->sctp_hdr->source);
6373
6374 /* The V-tag is going to be the same as the inbound packet if no
6375 * association exists, otherwise, use the peer's vtag.
6376 */
6377 if (asoc) {
6378 /* Special case the INIT-ACK as there is no peer's vtag
6379 * yet.
6380 */
6381 switch (chunk->chunk_hdr->type) {
6382 case SCTP_CID_INIT:
6383 case SCTP_CID_INIT_ACK:
6384 {
6385 struct sctp_initack_chunk *initack;
6386
6387 initack = (struct sctp_initack_chunk *)chunk->chunk_hdr;
6388 vtag = ntohl(initack->init_hdr.init_tag);
6389 break;
6390 }
6391 default:
6392 vtag = asoc->peer.i.init_tag;
6393 break;
6394 }
6395 } else {
6396 /* Special case the INIT and stale COOKIE_ECHO as there is no
6397 * vtag yet.
6398 */
6399 switch (chunk->chunk_hdr->type) {
6400 case SCTP_CID_INIT:
6401 {
6402 struct sctp_init_chunk *init;
6403
6404 init = (struct sctp_init_chunk *)chunk->chunk_hdr;
6405 vtag = ntohl(init->init_hdr.init_tag);
6406 break;
6407 }
6408 default:
6409 vtag = ntohl(chunk->sctp_hdr->vtag);
6410 break;
6411 }
6412 }
6413
6414 /* Make a transport for the bucket, Eliza... */
6415 transport = sctp_transport_new(net, sctp_source(chunk), GFP_ATOMIC);
6416 if (!transport)
6417 goto nomem;
6418
6419 transport->encap_port = SCTP_INPUT_CB(chunk->skb)->encap_port;
6420
6421 /* Cache a route for the transport with the chunk's destination as
6422 * the source address.
6423 */
6424 sctp_transport_route(transport, (union sctp_addr *)&chunk->dest,
6425 sctp_sk(net->sctp.ctl_sock));
6426
6427 packet = &transport->packet;
6428 sctp_packet_init(packet, transport, sport, dport);
6429 sctp_packet_config(packet, vtag, 0);
6430
6431 return packet;
6432
6433nomem:
6434 return NULL;
6435}
6436
6437/* Free the packet allocated earlier for responding in the OOTB condition. */
6438void sctp_ootb_pkt_free(struct sctp_packet *packet)
6439{
6440 sctp_transport_free(packet->transport);
6441}
6442
6443/* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */
6444static void sctp_send_stale_cookie_err(struct net *net,
6445 const struct sctp_endpoint *ep,
6446 const struct sctp_association *asoc,
6447 const struct sctp_chunk *chunk,
6448 struct sctp_cmd_seq *commands,
6449 struct sctp_chunk *err_chunk)
6450{
6451 struct sctp_packet *packet;
6452
6453 if (err_chunk) {
6454 packet = sctp_ootb_pkt_new(net, asoc, chunk);
6455 if (packet) {
6456 struct sctp_signed_cookie *cookie;
6457
6458 /* Override the OOTB vtag from the cookie. */
6459 cookie = chunk->subh.cookie_hdr;
6460 packet->vtag = cookie->c.peer_vtag;
6461
6462 /* Set the skb to the belonging sock for accounting. */
6463 err_chunk->skb->sk = ep->base.sk;
6464 sctp_packet_append_chunk(packet, err_chunk);
6465 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
6466 SCTP_PACKET(packet));
6467 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
6468 } else
6469 sctp_chunk_free (err_chunk);
6470 }
6471}
6472
6473
6474/* Process a data chunk */
6475static int sctp_eat_data(const struct sctp_association *asoc,
6476 struct sctp_chunk *chunk,
6477 struct sctp_cmd_seq *commands)
6478{
6479 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
6480 struct sock *sk = asoc->base.sk;
6481 struct net *net = sock_net(sk);
6482 struct sctp_datahdr *data_hdr;
6483 struct sctp_chunk *err;
6484 enum sctp_verb deliver;
6485 size_t datalen;
6486 __u32 tsn;
6487 int tmp;
6488
6489 data_hdr = (struct sctp_datahdr *)chunk->skb->data;
6490 chunk->subh.data_hdr = data_hdr;
6491 skb_pull(chunk->skb, sctp_datahdr_len(&asoc->stream));
6492
6493 tsn = ntohl(data_hdr->tsn);
6494 pr_debug("%s: TSN 0x%x\n", __func__, tsn);
6495
6496 /* ASSERT: Now skb->data is really the user data. */
6497
6498 /* Process ECN based congestion.
6499 *
6500 * Since the chunk structure is reused for all chunks within
6501 * a packet, we use ecn_ce_done to track if we've already
6502 * done CE processing for this packet.
6503 *
6504 * We need to do ECN processing even if we plan to discard the
6505 * chunk later.
6506 */
6507
6508 if (asoc->peer.ecn_capable && !chunk->ecn_ce_done) {
6509 struct sctp_af *af = SCTP_INPUT_CB(chunk->skb)->af;
6510 chunk->ecn_ce_done = 1;
6511
6512 if (af->is_ce(sctp_gso_headskb(chunk->skb))) {
6513 /* Do real work as side effect. */
6514 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_CE,
6515 SCTP_U32(tsn));
6516 }
6517 }
6518
6519 tmp = sctp_tsnmap_check(&asoc->peer.tsn_map, tsn);
6520 if (tmp < 0) {
6521 /* The TSN is too high--silently discard the chunk and
6522 * count on it getting retransmitted later.
6523 */
6524 if (chunk->asoc)
6525 chunk->asoc->stats.outofseqtsns++;
6526 return SCTP_IERROR_HIGH_TSN;
6527 } else if (tmp > 0) {
6528 /* This is a duplicate. Record it. */
6529 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_DUP, SCTP_U32(tsn));
6530 return SCTP_IERROR_DUP_TSN;
6531 }
6532
6533 /* This is a new TSN. */
6534
6535 /* Discard if there is no room in the receive window.
6536 * Actually, allow a little bit of overflow (up to a MTU).
6537 */
6538 datalen = ntohs(chunk->chunk_hdr->length);
6539 datalen -= sctp_datachk_len(&asoc->stream);
6540
6541 deliver = SCTP_CMD_CHUNK_ULP;
6542
6543 /* Think about partial delivery. */
6544 if ((datalen >= asoc->rwnd) && (!asoc->ulpq.pd_mode)) {
6545
6546 /* Even if we don't accept this chunk there is
6547 * memory pressure.
6548 */
6549 sctp_add_cmd_sf(commands, SCTP_CMD_PART_DELIVER, SCTP_NULL());
6550 }
6551
6552 /* Spill over rwnd a little bit. Note: While allowed, this spill over
6553 * seems a bit troublesome in that frag_point varies based on
6554 * PMTU. In cases, such as loopback, this might be a rather
6555 * large spill over.
6556 */
6557 if ((!chunk->data_accepted) && (!asoc->rwnd || asoc->rwnd_over ||
6558 (datalen > asoc->rwnd + asoc->frag_point))) {
6559
6560 /* If this is the next TSN, consider reneging to make
6561 * room. Note: Playing nice with a confused sender. A
6562 * malicious sender can still eat up all our buffer
6563 * space and in the future we may want to detect and
6564 * do more drastic reneging.
6565 */
6566 if (sctp_tsnmap_has_gap(map) &&
6567 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
6568 pr_debug("%s: reneging for tsn:%u\n", __func__, tsn);
6569 deliver = SCTP_CMD_RENEGE;
6570 } else {
6571 pr_debug("%s: discard tsn:%u len:%zu, rwnd:%d\n",
6572 __func__, tsn, datalen, asoc->rwnd);
6573
6574 return SCTP_IERROR_IGNORE_TSN;
6575 }
6576 }
6577
6578 /*
6579 * Also try to renege to limit our memory usage in the event that
6580 * we are under memory pressure
6581 * If we can't renege, don't worry about it, the sk_rmem_schedule
6582 * in sctp_ulpevent_make_rcvmsg will drop the frame if we grow our
6583 * memory usage too much
6584 */
6585 if (sk_under_memory_pressure(sk)) {
6586 if (sctp_tsnmap_has_gap(map) &&
6587 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
6588 pr_debug("%s: under pressure, reneging for tsn:%u\n",
6589 __func__, tsn);
6590 deliver = SCTP_CMD_RENEGE;
6591 }
6592 }
6593
6594 /*
6595 * Section 3.3.10.9 No User Data (9)
6596 *
6597 * Cause of error
6598 * ---------------
6599 * No User Data: This error cause is returned to the originator of a
6600 * DATA chunk if a received DATA chunk has no user data.
6601 */
6602 if (unlikely(0 == datalen)) {
6603 err = sctp_make_abort_no_data(asoc, chunk, tsn);
6604 if (err) {
6605 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
6606 SCTP_CHUNK(err));
6607 }
6608 /* We are going to ABORT, so we might as well stop
6609 * processing the rest of the chunks in the packet.
6610 */
6611 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
6612 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
6613 SCTP_ERROR(ECONNABORTED));
6614 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
6615 SCTP_PERR(SCTP_ERROR_NO_DATA));
6616 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
6617 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
6618 return SCTP_IERROR_NO_DATA;
6619 }
6620
6621 chunk->data_accepted = 1;
6622
6623 /* Note: Some chunks may get overcounted (if we drop) or overcounted
6624 * if we renege and the chunk arrives again.
6625 */
6626 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
6627 SCTP_INC_STATS(net, SCTP_MIB_INUNORDERCHUNKS);
6628 if (chunk->asoc)
6629 chunk->asoc->stats.iuodchunks++;
6630 } else {
6631 SCTP_INC_STATS(net, SCTP_MIB_INORDERCHUNKS);
6632 if (chunk->asoc)
6633 chunk->asoc->stats.iodchunks++;
6634 }
6635
6636 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
6637 *
6638 * If an endpoint receive a DATA chunk with an invalid stream
6639 * identifier, it shall acknowledge the reception of the DATA chunk
6640 * following the normal procedure, immediately send an ERROR chunk
6641 * with cause set to "Invalid Stream Identifier" (See Section 3.3.10)
6642 * and discard the DATA chunk.
6643 */
6644 if (ntohs(data_hdr->stream) >= asoc->stream.incnt) {
6645 /* Mark tsn as received even though we drop it */
6646 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_TSN, SCTP_U32(tsn));
6647
6648 err = sctp_make_op_error(asoc, chunk, SCTP_ERROR_INV_STRM,
6649 &data_hdr->stream,
6650 sizeof(data_hdr->stream),
6651 sizeof(u16));
6652 if (err)
6653 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
6654 SCTP_CHUNK(err));
6655 return SCTP_IERROR_BAD_STREAM;
6656 }
6657
6658 /* Check to see if the SSN is possible for this TSN.
6659 * The biggest gap we can record is 4K wide. Since SSNs wrap
6660 * at an unsigned short, there is no way that an SSN can
6661 * wrap and for a valid TSN. We can simply check if the current
6662 * SSN is smaller then the next expected one. If it is, it wrapped
6663 * and is invalid.
6664 */
6665 if (!asoc->stream.si->validate_data(chunk))
6666 return SCTP_IERROR_PROTO_VIOLATION;
6667
6668 /* Send the data up to the user. Note: Schedule the
6669 * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK
6670 * chunk needs the updated rwnd.
6671 */
6672 sctp_add_cmd_sf(commands, deliver, SCTP_CHUNK(chunk));
6673
6674 return SCTP_IERROR_NO_ERROR;
6675}