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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 *
7 * This file is part of the SCTP kernel implementation
8 *
9 * These functions work with the state functions in sctp_sm_statefuns.c
10 * to implement the state operations. These functions implement the
11 * steps which require modifying existing data structures.
12 *
13 * This SCTP implementation is free software;
14 * you can redistribute it and/or modify it under the terms of
15 * the GNU General Public License as published by
16 * the Free Software Foundation; either version 2, or (at your option)
17 * any later version.
18 *
19 * This SCTP implementation is distributed in the hope that it
20 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
21 * ************************
22 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
23 * See the GNU General Public License for more details.
24 *
25 * You should have received a copy of the GNU General Public License
26 * along with GNU CC; see the file COPYING. If not, see
27 * <http://www.gnu.org/licenses/>.
28 *
29 * Please send any bug reports or fixes you make to the
30 * email address(es):
31 * lksctp developers <linux-sctp@vger.kernel.org>
32 *
33 * Written or modified by:
34 * La Monte H.P. Yarroll <piggy@acm.org>
35 * Karl Knutson <karl@athena.chicago.il.us>
36 * C. Robin <chris@hundredacre.ac.uk>
37 * Jon Grimm <jgrimm@us.ibm.com>
38 * Xingang Guo <xingang.guo@intel.com>
39 * Dajiang Zhang <dajiang.zhang@nokia.com>
40 * Sridhar Samudrala <sri@us.ibm.com>
41 * Daisy Chang <daisyc@us.ibm.com>
42 * Ardelle Fan <ardelle.fan@intel.com>
43 * Kevin Gao <kevin.gao@intel.com>
44 */
45
46#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
47
48#include <linux/types.h>
49#include <linux/kernel.h>
50#include <linux/ip.h>
51#include <linux/ipv6.h>
52#include <linux/net.h>
53#include <linux/inet.h>
54#include <linux/scatterlist.h>
55#include <linux/crypto.h>
56#include <linux/slab.h>
57#include <net/sock.h>
58
59#include <linux/skbuff.h>
60#include <linux/random.h> /* for get_random_bytes */
61#include <net/sctp/sctp.h>
62#include <net/sctp/sm.h>
63
64static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc,
65 __u8 type, __u8 flags, int paylen);
66static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc,
67 __u8 flags, int paylen);
68static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc,
69 __u8 type, __u8 flags, int paylen);
70static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep,
71 const struct sctp_association *asoc,
72 const struct sctp_chunk *init_chunk,
73 int *cookie_len,
74 const __u8 *raw_addrs, int addrs_len);
75static int sctp_process_param(struct sctp_association *asoc,
76 union sctp_params param,
77 const union sctp_addr *peer_addr,
78 gfp_t gfp);
79static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
80 const void *data);
81static void *sctp_addto_chunk_fixed(struct sctp_chunk *, int len,
82 const void *data);
83
84/* Control chunk destructor */
85static void sctp_control_release_owner(struct sk_buff *skb)
86{
87 /*TODO: do memory release */
88}
89
90static void sctp_control_set_owner_w(struct sctp_chunk *chunk)
91{
92 struct sctp_association *asoc = chunk->asoc;
93 struct sk_buff *skb = chunk->skb;
94
95 /* TODO: properly account for control chunks.
96 * To do it right we'll need:
97 * 1) endpoint if association isn't known.
98 * 2) proper memory accounting.
99 *
100 * For now don't do anything for now.
101 */
102 skb->sk = asoc ? asoc->base.sk : NULL;
103 skb->destructor = sctp_control_release_owner;
104}
105
106/* What was the inbound interface for this chunk? */
107int sctp_chunk_iif(const struct sctp_chunk *chunk)
108{
109 struct sctp_af *af;
110 int iif = 0;
111
112 af = sctp_get_af_specific(ipver2af(ip_hdr(chunk->skb)->version));
113 if (af)
114 iif = af->skb_iif(chunk->skb);
115
116 return iif;
117}
118
119/* RFC 2960 3.3.2 Initiation (INIT) (1)
120 *
121 * Note 2: The ECN capable field is reserved for future use of
122 * Explicit Congestion Notification.
123 */
124static const struct sctp_paramhdr ecap_param = {
125 SCTP_PARAM_ECN_CAPABLE,
126 cpu_to_be16(sizeof(struct sctp_paramhdr)),
127};
128static const struct sctp_paramhdr prsctp_param = {
129 SCTP_PARAM_FWD_TSN_SUPPORT,
130 cpu_to_be16(sizeof(struct sctp_paramhdr)),
131};
132
133/* A helper to initialize an op error inside a
134 * provided chunk, as most cause codes will be embedded inside an
135 * abort chunk.
136 */
137void sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code,
138 size_t paylen)
139{
140 sctp_errhdr_t err;
141 __u16 len;
142
143 /* Cause code constants are now defined in network order. */
144 err.cause = cause_code;
145 len = sizeof(sctp_errhdr_t) + paylen;
146 err.length = htons(len);
147 chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(sctp_errhdr_t), &err);
148}
149
150/* A helper to initialize an op error inside a
151 * provided chunk, as most cause codes will be embedded inside an
152 * abort chunk. Differs from sctp_init_cause in that it won't oops
153 * if there isn't enough space in the op error chunk
154 */
155static int sctp_init_cause_fixed(struct sctp_chunk *chunk, __be16 cause_code,
156 size_t paylen)
157{
158 sctp_errhdr_t err;
159 __u16 len;
160
161 /* Cause code constants are now defined in network order. */
162 err.cause = cause_code;
163 len = sizeof(sctp_errhdr_t) + paylen;
164 err.length = htons(len);
165
166 if (skb_tailroom(chunk->skb) < len)
167 return -ENOSPC;
168 chunk->subh.err_hdr = sctp_addto_chunk_fixed(chunk,
169 sizeof(sctp_errhdr_t),
170 &err);
171 return 0;
172}
173/* 3.3.2 Initiation (INIT) (1)
174 *
175 * This chunk is used to initiate a SCTP association between two
176 * endpoints. The format of the INIT chunk is shown below:
177 *
178 * 0 1 2 3
179 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
180 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
181 * | Type = 1 | Chunk Flags | Chunk Length |
182 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
183 * | Initiate Tag |
184 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
185 * | Advertised Receiver Window Credit (a_rwnd) |
186 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
187 * | Number of Outbound Streams | Number of Inbound Streams |
188 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
189 * | Initial TSN |
190 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
191 * \ \
192 * / Optional/Variable-Length Parameters /
193 * \ \
194 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
195 *
196 *
197 * The INIT chunk contains the following parameters. Unless otherwise
198 * noted, each parameter MUST only be included once in the INIT chunk.
199 *
200 * Fixed Parameters Status
201 * ----------------------------------------------
202 * Initiate Tag Mandatory
203 * Advertised Receiver Window Credit Mandatory
204 * Number of Outbound Streams Mandatory
205 * Number of Inbound Streams Mandatory
206 * Initial TSN Mandatory
207 *
208 * Variable Parameters Status Type Value
209 * -------------------------------------------------------------
210 * IPv4 Address (Note 1) Optional 5
211 * IPv6 Address (Note 1) Optional 6
212 * Cookie Preservative Optional 9
213 * Reserved for ECN Capable (Note 2) Optional 32768 (0x8000)
214 * Host Name Address (Note 3) Optional 11
215 * Supported Address Types (Note 4) Optional 12
216 */
217struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc,
218 const struct sctp_bind_addr *bp,
219 gfp_t gfp, int vparam_len)
220{
221 struct net *net = sock_net(asoc->base.sk);
222 struct sctp_endpoint *ep = asoc->ep;
223 sctp_inithdr_t init;
224 union sctp_params addrs;
225 size_t chunksize;
226 struct sctp_chunk *retval = NULL;
227 int num_types, addrs_len = 0;
228 struct sctp_sock *sp;
229 sctp_supported_addrs_param_t sat;
230 __be16 types[2];
231 sctp_adaptation_ind_param_t aiparam;
232 sctp_supported_ext_param_t ext_param;
233 int num_ext = 0;
234 __u8 extensions[3];
235 sctp_paramhdr_t *auth_chunks = NULL,
236 *auth_hmacs = NULL;
237
238 /* RFC 2960 3.3.2 Initiation (INIT) (1)
239 *
240 * Note 1: The INIT chunks can contain multiple addresses that
241 * can be IPv4 and/or IPv6 in any combination.
242 */
243 retval = NULL;
244
245 /* Convert the provided bind address list to raw format. */
246 addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp);
247
248 init.init_tag = htonl(asoc->c.my_vtag);
249 init.a_rwnd = htonl(asoc->rwnd);
250 init.num_outbound_streams = htons(asoc->c.sinit_num_ostreams);
251 init.num_inbound_streams = htons(asoc->c.sinit_max_instreams);
252 init.initial_tsn = htonl(asoc->c.initial_tsn);
253
254 /* How many address types are needed? */
255 sp = sctp_sk(asoc->base.sk);
256 num_types = sp->pf->supported_addrs(sp, types);
257
258 chunksize = sizeof(init) + addrs_len;
259 chunksize += WORD_ROUND(SCTP_SAT_LEN(num_types));
260 chunksize += sizeof(ecap_param);
261
262 if (net->sctp.prsctp_enable)
263 chunksize += sizeof(prsctp_param);
264
265 /* ADDIP: Section 4.2.7:
266 * An implementation supporting this extension [ADDIP] MUST list
267 * the ASCONF,the ASCONF-ACK, and the AUTH chunks in its INIT and
268 * INIT-ACK parameters.
269 */
270 if (net->sctp.addip_enable) {
271 extensions[num_ext] = SCTP_CID_ASCONF;
272 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
273 num_ext += 2;
274 }
275
276 if (sp->adaptation_ind)
277 chunksize += sizeof(aiparam);
278
279 chunksize += vparam_len;
280
281 /* Account for AUTH related parameters */
282 if (ep->auth_enable) {
283 /* Add random parameter length*/
284 chunksize += sizeof(asoc->c.auth_random);
285
286 /* Add HMACS parameter length if any were defined */
287 auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs;
288 if (auth_hmacs->length)
289 chunksize += WORD_ROUND(ntohs(auth_hmacs->length));
290 else
291 auth_hmacs = NULL;
292
293 /* Add CHUNKS parameter length */
294 auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks;
295 if (auth_chunks->length)
296 chunksize += WORD_ROUND(ntohs(auth_chunks->length));
297 else
298 auth_chunks = NULL;
299
300 extensions[num_ext] = SCTP_CID_AUTH;
301 num_ext += 1;
302 }
303
304 /* If we have any extensions to report, account for that */
305 if (num_ext)
306 chunksize += WORD_ROUND(sizeof(sctp_supported_ext_param_t) +
307 num_ext);
308
309 /* RFC 2960 3.3.2 Initiation (INIT) (1)
310 *
311 * Note 3: An INIT chunk MUST NOT contain more than one Host
312 * Name address parameter. Moreover, the sender of the INIT
313 * MUST NOT combine any other address types with the Host Name
314 * address in the INIT. The receiver of INIT MUST ignore any
315 * other address types if the Host Name address parameter is
316 * present in the received INIT chunk.
317 *
318 * PLEASE DO NOT FIXME [This version does not support Host Name.]
319 */
320
321 retval = sctp_make_control(asoc, SCTP_CID_INIT, 0, chunksize);
322 if (!retval)
323 goto nodata;
324
325 retval->subh.init_hdr =
326 sctp_addto_chunk(retval, sizeof(init), &init);
327 retval->param_hdr.v =
328 sctp_addto_chunk(retval, addrs_len, addrs.v);
329
330 /* RFC 2960 3.3.2 Initiation (INIT) (1)
331 *
332 * Note 4: This parameter, when present, specifies all the
333 * address types the sending endpoint can support. The absence
334 * of this parameter indicates that the sending endpoint can
335 * support any address type.
336 */
337 sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES;
338 sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types));
339 sctp_addto_chunk(retval, sizeof(sat), &sat);
340 sctp_addto_chunk(retval, num_types * sizeof(__u16), &types);
341
342 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
343
344 /* Add the supported extensions parameter. Be nice and add this
345 * fist before addiding the parameters for the extensions themselves
346 */
347 if (num_ext) {
348 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
349 ext_param.param_hdr.length =
350 htons(sizeof(sctp_supported_ext_param_t) + num_ext);
351 sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t),
352 &ext_param);
353 sctp_addto_param(retval, num_ext, extensions);
354 }
355
356 if (net->sctp.prsctp_enable)
357 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
358
359 if (sp->adaptation_ind) {
360 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
361 aiparam.param_hdr.length = htons(sizeof(aiparam));
362 aiparam.adaptation_ind = htonl(sp->adaptation_ind);
363 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
364 }
365
366 /* Add SCTP-AUTH chunks to the parameter list */
367 if (ep->auth_enable) {
368 sctp_addto_chunk(retval, sizeof(asoc->c.auth_random),
369 asoc->c.auth_random);
370 if (auth_hmacs)
371 sctp_addto_chunk(retval, ntohs(auth_hmacs->length),
372 auth_hmacs);
373 if (auth_chunks)
374 sctp_addto_chunk(retval, ntohs(auth_chunks->length),
375 auth_chunks);
376 }
377nodata:
378 kfree(addrs.v);
379 return retval;
380}
381
382struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc,
383 const struct sctp_chunk *chunk,
384 gfp_t gfp, int unkparam_len)
385{
386 sctp_inithdr_t initack;
387 struct sctp_chunk *retval;
388 union sctp_params addrs;
389 struct sctp_sock *sp;
390 int addrs_len;
391 sctp_cookie_param_t *cookie;
392 int cookie_len;
393 size_t chunksize;
394 sctp_adaptation_ind_param_t aiparam;
395 sctp_supported_ext_param_t ext_param;
396 int num_ext = 0;
397 __u8 extensions[3];
398 sctp_paramhdr_t *auth_chunks = NULL,
399 *auth_hmacs = NULL,
400 *auth_random = NULL;
401
402 retval = NULL;
403
404 /* Note: there may be no addresses to embed. */
405 addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp);
406
407 initack.init_tag = htonl(asoc->c.my_vtag);
408 initack.a_rwnd = htonl(asoc->rwnd);
409 initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams);
410 initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams);
411 initack.initial_tsn = htonl(asoc->c.initial_tsn);
412
413 /* FIXME: We really ought to build the cookie right
414 * into the packet instead of allocating more fresh memory.
415 */
416 cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len,
417 addrs.v, addrs_len);
418 if (!cookie)
419 goto nomem_cookie;
420
421 /* Calculate the total size of allocation, include the reserved
422 * space for reporting unknown parameters if it is specified.
423 */
424 sp = sctp_sk(asoc->base.sk);
425 chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len;
426
427 /* Tell peer that we'll do ECN only if peer advertised such cap. */
428 if (asoc->peer.ecn_capable)
429 chunksize += sizeof(ecap_param);
430
431 if (asoc->peer.prsctp_capable)
432 chunksize += sizeof(prsctp_param);
433
434 if (asoc->peer.asconf_capable) {
435 extensions[num_ext] = SCTP_CID_ASCONF;
436 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
437 num_ext += 2;
438 }
439
440 if (sp->adaptation_ind)
441 chunksize += sizeof(aiparam);
442
443 if (asoc->peer.auth_capable) {
444 auth_random = (sctp_paramhdr_t *)asoc->c.auth_random;
445 chunksize += ntohs(auth_random->length);
446
447 auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs;
448 if (auth_hmacs->length)
449 chunksize += WORD_ROUND(ntohs(auth_hmacs->length));
450 else
451 auth_hmacs = NULL;
452
453 auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks;
454 if (auth_chunks->length)
455 chunksize += WORD_ROUND(ntohs(auth_chunks->length));
456 else
457 auth_chunks = NULL;
458
459 extensions[num_ext] = SCTP_CID_AUTH;
460 num_ext += 1;
461 }
462
463 if (num_ext)
464 chunksize += WORD_ROUND(sizeof(sctp_supported_ext_param_t) +
465 num_ext);
466
467 /* Now allocate and fill out the chunk. */
468 retval = sctp_make_control(asoc, SCTP_CID_INIT_ACK, 0, chunksize);
469 if (!retval)
470 goto nomem_chunk;
471
472 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
473 *
474 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
475 * HEARTBEAT ACK, * etc.) to the same destination transport
476 * address from which it received the DATA or control chunk
477 * to which it is replying.
478 *
479 * [INIT ACK back to where the INIT came from.]
480 */
481 retval->transport = chunk->transport;
482
483 retval->subh.init_hdr =
484 sctp_addto_chunk(retval, sizeof(initack), &initack);
485 retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v);
486 sctp_addto_chunk(retval, cookie_len, cookie);
487 if (asoc->peer.ecn_capable)
488 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
489 if (num_ext) {
490 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
491 ext_param.param_hdr.length =
492 htons(sizeof(sctp_supported_ext_param_t) + num_ext);
493 sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t),
494 &ext_param);
495 sctp_addto_param(retval, num_ext, extensions);
496 }
497 if (asoc->peer.prsctp_capable)
498 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
499
500 if (sp->adaptation_ind) {
501 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
502 aiparam.param_hdr.length = htons(sizeof(aiparam));
503 aiparam.adaptation_ind = htonl(sp->adaptation_ind);
504 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
505 }
506
507 if (asoc->peer.auth_capable) {
508 sctp_addto_chunk(retval, ntohs(auth_random->length),
509 auth_random);
510 if (auth_hmacs)
511 sctp_addto_chunk(retval, ntohs(auth_hmacs->length),
512 auth_hmacs);
513 if (auth_chunks)
514 sctp_addto_chunk(retval, ntohs(auth_chunks->length),
515 auth_chunks);
516 }
517
518 /* We need to remove the const qualifier at this point. */
519 retval->asoc = (struct sctp_association *) asoc;
520
521nomem_chunk:
522 kfree(cookie);
523nomem_cookie:
524 kfree(addrs.v);
525 return retval;
526}
527
528/* 3.3.11 Cookie Echo (COOKIE ECHO) (10):
529 *
530 * This chunk is used only during the initialization of an association.
531 * It is sent by the initiator of an association to its peer to complete
532 * the initialization process. This chunk MUST precede any DATA chunk
533 * sent within the association, but MAY be bundled with one or more DATA
534 * chunks in the same packet.
535 *
536 * 0 1 2 3
537 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
538 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
539 * | Type = 10 |Chunk Flags | Length |
540 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
541 * / Cookie /
542 * \ \
543 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
544 *
545 * Chunk Flags: 8 bit
546 *
547 * Set to zero on transmit and ignored on receipt.
548 *
549 * Length: 16 bits (unsigned integer)
550 *
551 * Set to the size of the chunk in bytes, including the 4 bytes of
552 * the chunk header and the size of the Cookie.
553 *
554 * Cookie: variable size
555 *
556 * This field must contain the exact cookie received in the
557 * State Cookie parameter from the previous INIT ACK.
558 *
559 * An implementation SHOULD make the cookie as small as possible
560 * to insure interoperability.
561 */
562struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc,
563 const struct sctp_chunk *chunk)
564{
565 struct sctp_chunk *retval;
566 void *cookie;
567 int cookie_len;
568
569 cookie = asoc->peer.cookie;
570 cookie_len = asoc->peer.cookie_len;
571
572 /* Build a cookie echo chunk. */
573 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ECHO, 0, cookie_len);
574 if (!retval)
575 goto nodata;
576 retval->subh.cookie_hdr =
577 sctp_addto_chunk(retval, cookie_len, cookie);
578
579 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
580 *
581 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
582 * HEARTBEAT ACK, * etc.) to the same destination transport
583 * address from which it * received the DATA or control chunk
584 * to which it is replying.
585 *
586 * [COOKIE ECHO back to where the INIT ACK came from.]
587 */
588 if (chunk)
589 retval->transport = chunk->transport;
590
591nodata:
592 return retval;
593}
594
595/* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11):
596 *
597 * This chunk is used only during the initialization of an
598 * association. It is used to acknowledge the receipt of a COOKIE
599 * ECHO chunk. This chunk MUST precede any DATA or SACK chunk sent
600 * within the association, but MAY be bundled with one or more DATA
601 * chunks or SACK chunk in the same SCTP packet.
602 *
603 * 0 1 2 3
604 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
605 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
606 * | Type = 11 |Chunk Flags | Length = 4 |
607 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
608 *
609 * Chunk Flags: 8 bits
610 *
611 * Set to zero on transmit and ignored on receipt.
612 */
613struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc,
614 const struct sctp_chunk *chunk)
615{
616 struct sctp_chunk *retval;
617
618 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ACK, 0, 0);
619
620 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
621 *
622 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
623 * HEARTBEAT ACK, * etc.) to the same destination transport
624 * address from which it * received the DATA or control chunk
625 * to which it is replying.
626 *
627 * [COOKIE ACK back to where the COOKIE ECHO came from.]
628 */
629 if (retval && chunk)
630 retval->transport = chunk->transport;
631
632 return retval;
633}
634
635/*
636 * Appendix A: Explicit Congestion Notification:
637 * CWR:
638 *
639 * RFC 2481 details a specific bit for a sender to send in the header of
640 * its next outbound TCP segment to indicate to its peer that it has
641 * reduced its congestion window. This is termed the CWR bit. For
642 * SCTP the same indication is made by including the CWR chunk.
643 * This chunk contains one data element, i.e. the TSN number that
644 * was sent in the ECNE chunk. This element represents the lowest
645 * TSN number in the datagram that was originally marked with the
646 * CE bit.
647 *
648 * 0 1 2 3
649 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
650 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
651 * | Chunk Type=13 | Flags=00000000| Chunk Length = 8 |
652 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
653 * | Lowest TSN Number |
654 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
655 *
656 * Note: The CWR is considered a Control chunk.
657 */
658struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc,
659 const __u32 lowest_tsn,
660 const struct sctp_chunk *chunk)
661{
662 struct sctp_chunk *retval;
663 sctp_cwrhdr_t cwr;
664
665 cwr.lowest_tsn = htonl(lowest_tsn);
666 retval = sctp_make_control(asoc, SCTP_CID_ECN_CWR, 0,
667 sizeof(sctp_cwrhdr_t));
668
669 if (!retval)
670 goto nodata;
671
672 retval->subh.ecn_cwr_hdr =
673 sctp_addto_chunk(retval, sizeof(cwr), &cwr);
674
675 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
676 *
677 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
678 * HEARTBEAT ACK, * etc.) to the same destination transport
679 * address from which it * received the DATA or control chunk
680 * to which it is replying.
681 *
682 * [Report a reduced congestion window back to where the ECNE
683 * came from.]
684 */
685 if (chunk)
686 retval->transport = chunk->transport;
687
688nodata:
689 return retval;
690}
691
692/* Make an ECNE chunk. This is a congestion experienced report. */
693struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc,
694 const __u32 lowest_tsn)
695{
696 struct sctp_chunk *retval;
697 sctp_ecnehdr_t ecne;
698
699 ecne.lowest_tsn = htonl(lowest_tsn);
700 retval = sctp_make_control(asoc, SCTP_CID_ECN_ECNE, 0,
701 sizeof(sctp_ecnehdr_t));
702 if (!retval)
703 goto nodata;
704 retval->subh.ecne_hdr =
705 sctp_addto_chunk(retval, sizeof(ecne), &ecne);
706
707nodata:
708 return retval;
709}
710
711/* Make a DATA chunk for the given association from the provided
712 * parameters. However, do not populate the data payload.
713 */
714struct sctp_chunk *sctp_make_datafrag_empty(struct sctp_association *asoc,
715 const struct sctp_sndrcvinfo *sinfo,
716 int data_len, __u8 flags, __u16 ssn)
717{
718 struct sctp_chunk *retval;
719 struct sctp_datahdr dp;
720 int chunk_len;
721
722 /* We assign the TSN as LATE as possible, not here when
723 * creating the chunk.
724 */
725 dp.tsn = 0;
726 dp.stream = htons(sinfo->sinfo_stream);
727 dp.ppid = sinfo->sinfo_ppid;
728
729 /* Set the flags for an unordered send. */
730 if (sinfo->sinfo_flags & SCTP_UNORDERED) {
731 flags |= SCTP_DATA_UNORDERED;
732 dp.ssn = 0;
733 } else
734 dp.ssn = htons(ssn);
735
736 chunk_len = sizeof(dp) + data_len;
737 retval = sctp_make_data(asoc, flags, chunk_len);
738 if (!retval)
739 goto nodata;
740
741 retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp);
742 memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo));
743
744nodata:
745 return retval;
746}
747
748/* Create a selective ackowledgement (SACK) for the given
749 * association. This reports on which TSN's we've seen to date,
750 * including duplicates and gaps.
751 */
752struct sctp_chunk *sctp_make_sack(const struct sctp_association *asoc)
753{
754 struct sctp_chunk *retval;
755 struct sctp_sackhdr sack;
756 int len;
757 __u32 ctsn;
758 __u16 num_gabs, num_dup_tsns;
759 struct sctp_association *aptr = (struct sctp_association *)asoc;
760 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
761 struct sctp_gap_ack_block gabs[SCTP_MAX_GABS];
762 struct sctp_transport *trans;
763
764 memset(gabs, 0, sizeof(gabs));
765 ctsn = sctp_tsnmap_get_ctsn(map);
766
767 pr_debug("%s: sackCTSNAck sent:0x%x\n", __func__, ctsn);
768
769 /* How much room is needed in the chunk? */
770 num_gabs = sctp_tsnmap_num_gabs(map, gabs);
771 num_dup_tsns = sctp_tsnmap_num_dups(map);
772
773 /* Initialize the SACK header. */
774 sack.cum_tsn_ack = htonl(ctsn);
775 sack.a_rwnd = htonl(asoc->a_rwnd);
776 sack.num_gap_ack_blocks = htons(num_gabs);
777 sack.num_dup_tsns = htons(num_dup_tsns);
778
779 len = sizeof(sack)
780 + sizeof(struct sctp_gap_ack_block) * num_gabs
781 + sizeof(__u32) * num_dup_tsns;
782
783 /* Create the chunk. */
784 retval = sctp_make_control(asoc, SCTP_CID_SACK, 0, len);
785 if (!retval)
786 goto nodata;
787
788 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
789 *
790 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
791 * HEARTBEAT ACK, etc.) to the same destination transport
792 * address from which it received the DATA or control chunk to
793 * which it is replying. This rule should also be followed if
794 * the endpoint is bundling DATA chunks together with the
795 * reply chunk.
796 *
797 * However, when acknowledging multiple DATA chunks received
798 * in packets from different source addresses in a single
799 * SACK, the SACK chunk may be transmitted to one of the
800 * destination transport addresses from which the DATA or
801 * control chunks being acknowledged were received.
802 *
803 * [BUG: We do not implement the following paragraph.
804 * Perhaps we should remember the last transport we used for a
805 * SACK and avoid that (if possible) if we have seen any
806 * duplicates. --piggy]
807 *
808 * When a receiver of a duplicate DATA chunk sends a SACK to a
809 * multi- homed endpoint it MAY be beneficial to vary the
810 * destination address and not use the source address of the
811 * DATA chunk. The reason being that receiving a duplicate
812 * from a multi-homed endpoint might indicate that the return
813 * path (as specified in the source address of the DATA chunk)
814 * for the SACK is broken.
815 *
816 * [Send to the address from which we last received a DATA chunk.]
817 */
818 retval->transport = asoc->peer.last_data_from;
819
820 retval->subh.sack_hdr =
821 sctp_addto_chunk(retval, sizeof(sack), &sack);
822
823 /* Add the gap ack block information. */
824 if (num_gabs)
825 sctp_addto_chunk(retval, sizeof(__u32) * num_gabs,
826 gabs);
827
828 /* Add the duplicate TSN information. */
829 if (num_dup_tsns) {
830 aptr->stats.idupchunks += num_dup_tsns;
831 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns,
832 sctp_tsnmap_get_dups(map));
833 }
834 /* Once we have a sack generated, check to see what our sack
835 * generation is, if its 0, reset the transports to 0, and reset
836 * the association generation to 1
837 *
838 * The idea is that zero is never used as a valid generation for the
839 * association so no transport will match after a wrap event like this,
840 * Until the next sack
841 */
842 if (++aptr->peer.sack_generation == 0) {
843 list_for_each_entry(trans, &asoc->peer.transport_addr_list,
844 transports)
845 trans->sack_generation = 0;
846 aptr->peer.sack_generation = 1;
847 }
848nodata:
849 return retval;
850}
851
852/* Make a SHUTDOWN chunk. */
853struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc,
854 const struct sctp_chunk *chunk)
855{
856 struct sctp_chunk *retval;
857 sctp_shutdownhdr_t shut;
858 __u32 ctsn;
859
860 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
861 shut.cum_tsn_ack = htonl(ctsn);
862
863 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN, 0,
864 sizeof(sctp_shutdownhdr_t));
865 if (!retval)
866 goto nodata;
867
868 retval->subh.shutdown_hdr =
869 sctp_addto_chunk(retval, sizeof(shut), &shut);
870
871 if (chunk)
872 retval->transport = chunk->transport;
873nodata:
874 return retval;
875}
876
877struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc,
878 const struct sctp_chunk *chunk)
879{
880 struct sctp_chunk *retval;
881
882 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0);
883
884 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
885 *
886 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
887 * HEARTBEAT ACK, * etc.) to the same destination transport
888 * address from which it * received the DATA or control chunk
889 * to which it is replying.
890 *
891 * [ACK back to where the SHUTDOWN came from.]
892 */
893 if (retval && chunk)
894 retval->transport = chunk->transport;
895
896 return retval;
897}
898
899struct sctp_chunk *sctp_make_shutdown_complete(
900 const struct sctp_association *asoc,
901 const struct sctp_chunk *chunk)
902{
903 struct sctp_chunk *retval;
904 __u8 flags = 0;
905
906 /* Set the T-bit if we have no association (vtag will be
907 * reflected)
908 */
909 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T;
910
911 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 0);
912
913 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
914 *
915 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
916 * HEARTBEAT ACK, * etc.) to the same destination transport
917 * address from which it * received the DATA or control chunk
918 * to which it is replying.
919 *
920 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK
921 * came from.]
922 */
923 if (retval && chunk)
924 retval->transport = chunk->transport;
925
926 return retval;
927}
928
929/* Create an ABORT. Note that we set the T bit if we have no
930 * association, except when responding to an INIT (sctpimpguide 2.41).
931 */
932struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc,
933 const struct sctp_chunk *chunk,
934 const size_t hint)
935{
936 struct sctp_chunk *retval;
937 __u8 flags = 0;
938
939 /* Set the T-bit if we have no association and 'chunk' is not
940 * an INIT (vtag will be reflected).
941 */
942 if (!asoc) {
943 if (chunk && chunk->chunk_hdr &&
944 chunk->chunk_hdr->type == SCTP_CID_INIT)
945 flags = 0;
946 else
947 flags = SCTP_CHUNK_FLAG_T;
948 }
949
950 retval = sctp_make_control(asoc, SCTP_CID_ABORT, flags, hint);
951
952 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
953 *
954 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
955 * HEARTBEAT ACK, * etc.) to the same destination transport
956 * address from which it * received the DATA or control chunk
957 * to which it is replying.
958 *
959 * [ABORT back to where the offender came from.]
960 */
961 if (retval && chunk)
962 retval->transport = chunk->transport;
963
964 return retval;
965}
966
967/* Helper to create ABORT with a NO_USER_DATA error. */
968struct sctp_chunk *sctp_make_abort_no_data(
969 const struct sctp_association *asoc,
970 const struct sctp_chunk *chunk, __u32 tsn)
971{
972 struct sctp_chunk *retval;
973 __be32 payload;
974
975 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t)
976 + sizeof(tsn));
977
978 if (!retval)
979 goto no_mem;
980
981 /* Put the tsn back into network byte order. */
982 payload = htonl(tsn);
983 sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload));
984 sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload);
985
986 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
987 *
988 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
989 * HEARTBEAT ACK, * etc.) to the same destination transport
990 * address from which it * received the DATA or control chunk
991 * to which it is replying.
992 *
993 * [ABORT back to where the offender came from.]
994 */
995 if (chunk)
996 retval->transport = chunk->transport;
997
998no_mem:
999 return retval;
1000}
1001
1002/* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */
1003struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc,
1004 const struct msghdr *msg,
1005 size_t paylen)
1006{
1007 struct sctp_chunk *retval;
1008 void *payload = NULL;
1009 int err;
1010
1011 retval = sctp_make_abort(asoc, NULL, sizeof(sctp_errhdr_t) + paylen);
1012 if (!retval)
1013 goto err_chunk;
1014
1015 if (paylen) {
1016 /* Put the msg_iov together into payload. */
1017 payload = kmalloc(paylen, GFP_KERNEL);
1018 if (!payload)
1019 goto err_payload;
1020
1021 err = memcpy_fromiovec(payload, msg->msg_iov, paylen);
1022 if (err < 0)
1023 goto err_copy;
1024 }
1025
1026 sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen);
1027 sctp_addto_chunk(retval, paylen, payload);
1028
1029 if (paylen)
1030 kfree(payload);
1031
1032 return retval;
1033
1034err_copy:
1035 kfree(payload);
1036err_payload:
1037 sctp_chunk_free(retval);
1038 retval = NULL;
1039err_chunk:
1040 return retval;
1041}
1042
1043/* Append bytes to the end of a parameter. Will panic if chunk is not big
1044 * enough.
1045 */
1046static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
1047 const void *data)
1048{
1049 void *target;
1050 int chunklen = ntohs(chunk->chunk_hdr->length);
1051
1052 target = skb_put(chunk->skb, len);
1053
1054 if (data)
1055 memcpy(target, data, len);
1056 else
1057 memset(target, 0, len);
1058
1059 /* Adjust the chunk length field. */
1060 chunk->chunk_hdr->length = htons(chunklen + len);
1061 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1062
1063 return target;
1064}
1065
1066/* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */
1067struct sctp_chunk *sctp_make_abort_violation(
1068 const struct sctp_association *asoc,
1069 const struct sctp_chunk *chunk,
1070 const __u8 *payload,
1071 const size_t paylen)
1072{
1073 struct sctp_chunk *retval;
1074 struct sctp_paramhdr phdr;
1075
1076 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) + paylen
1077 + sizeof(sctp_paramhdr_t));
1078 if (!retval)
1079 goto end;
1080
1081 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen
1082 + sizeof(sctp_paramhdr_t));
1083
1084 phdr.type = htons(chunk->chunk_hdr->type);
1085 phdr.length = chunk->chunk_hdr->length;
1086 sctp_addto_chunk(retval, paylen, payload);
1087 sctp_addto_param(retval, sizeof(sctp_paramhdr_t), &phdr);
1088
1089end:
1090 return retval;
1091}
1092
1093struct sctp_chunk *sctp_make_violation_paramlen(
1094 const struct sctp_association *asoc,
1095 const struct sctp_chunk *chunk,
1096 struct sctp_paramhdr *param)
1097{
1098 struct sctp_chunk *retval;
1099 static const char error[] = "The following parameter had invalid length:";
1100 size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t) +
1101 sizeof(sctp_paramhdr_t);
1102
1103 retval = sctp_make_abort(asoc, chunk, payload_len);
1104 if (!retval)
1105 goto nodata;
1106
1107 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION,
1108 sizeof(error) + sizeof(sctp_paramhdr_t));
1109 sctp_addto_chunk(retval, sizeof(error), error);
1110 sctp_addto_param(retval, sizeof(sctp_paramhdr_t), param);
1111
1112nodata:
1113 return retval;
1114}
1115
1116struct sctp_chunk *sctp_make_violation_max_retrans(
1117 const struct sctp_association *asoc,
1118 const struct sctp_chunk *chunk)
1119{
1120 struct sctp_chunk *retval;
1121 static const char error[] = "Association exceeded its max_retans count";
1122 size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t);
1123
1124 retval = sctp_make_abort(asoc, chunk, payload_len);
1125 if (!retval)
1126 goto nodata;
1127
1128 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error));
1129 sctp_addto_chunk(retval, sizeof(error), error);
1130
1131nodata:
1132 return retval;
1133}
1134
1135/* Make a HEARTBEAT chunk. */
1136struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc,
1137 const struct sctp_transport *transport)
1138{
1139 struct sctp_chunk *retval;
1140 sctp_sender_hb_info_t hbinfo;
1141
1142 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT, 0, sizeof(hbinfo));
1143
1144 if (!retval)
1145 goto nodata;
1146
1147 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO;
1148 hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t));
1149 hbinfo.daddr = transport->ipaddr;
1150 hbinfo.sent_at = jiffies;
1151 hbinfo.hb_nonce = transport->hb_nonce;
1152
1153 /* Cast away the 'const', as this is just telling the chunk
1154 * what transport it belongs to.
1155 */
1156 retval->transport = (struct sctp_transport *) transport;
1157 retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo),
1158 &hbinfo);
1159
1160nodata:
1161 return retval;
1162}
1163
1164struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc,
1165 const struct sctp_chunk *chunk,
1166 const void *payload, const size_t paylen)
1167{
1168 struct sctp_chunk *retval;
1169
1170 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen);
1171 if (!retval)
1172 goto nodata;
1173
1174 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload);
1175
1176 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
1177 *
1178 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1179 * HEARTBEAT ACK, * etc.) to the same destination transport
1180 * address from which it * received the DATA or control chunk
1181 * to which it is replying.
1182 *
1183 * [HBACK back to where the HEARTBEAT came from.]
1184 */
1185 if (chunk)
1186 retval->transport = chunk->transport;
1187
1188nodata:
1189 return retval;
1190}
1191
1192/* Create an Operation Error chunk with the specified space reserved.
1193 * This routine can be used for containing multiple causes in the chunk.
1194 */
1195static struct sctp_chunk *sctp_make_op_error_space(
1196 const struct sctp_association *asoc,
1197 const struct sctp_chunk *chunk,
1198 size_t size)
1199{
1200 struct sctp_chunk *retval;
1201
1202 retval = sctp_make_control(asoc, SCTP_CID_ERROR, 0,
1203 sizeof(sctp_errhdr_t) + size);
1204 if (!retval)
1205 goto nodata;
1206
1207 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
1208 *
1209 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1210 * HEARTBEAT ACK, etc.) to the same destination transport
1211 * address from which it received the DATA or control chunk
1212 * to which it is replying.
1213 *
1214 */
1215 if (chunk)
1216 retval->transport = chunk->transport;
1217
1218nodata:
1219 return retval;
1220}
1221
1222/* Create an Operation Error chunk of a fixed size,
1223 * specifically, max(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT)
1224 * This is a helper function to allocate an error chunk for
1225 * for those invalid parameter codes in which we may not want
1226 * to report all the errors, if the incoming chunk is large
1227 */
1228static inline struct sctp_chunk *sctp_make_op_error_fixed(
1229 const struct sctp_association *asoc,
1230 const struct sctp_chunk *chunk)
1231{
1232 size_t size = asoc ? asoc->pathmtu : 0;
1233
1234 if (!size)
1235 size = SCTP_DEFAULT_MAXSEGMENT;
1236
1237 return sctp_make_op_error_space(asoc, chunk, size);
1238}
1239
1240/* Create an Operation Error chunk. */
1241struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc,
1242 const struct sctp_chunk *chunk,
1243 __be16 cause_code, const void *payload,
1244 size_t paylen, size_t reserve_tail)
1245{
1246 struct sctp_chunk *retval;
1247
1248 retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail);
1249 if (!retval)
1250 goto nodata;
1251
1252 sctp_init_cause(retval, cause_code, paylen + reserve_tail);
1253 sctp_addto_chunk(retval, paylen, payload);
1254 if (reserve_tail)
1255 sctp_addto_param(retval, reserve_tail, NULL);
1256
1257nodata:
1258 return retval;
1259}
1260
1261struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc)
1262{
1263 struct sctp_chunk *retval;
1264 struct sctp_hmac *hmac_desc;
1265 struct sctp_authhdr auth_hdr;
1266 __u8 *hmac;
1267
1268 /* Get the first hmac that the peer told us to use */
1269 hmac_desc = sctp_auth_asoc_get_hmac(asoc);
1270 if (unlikely(!hmac_desc))
1271 return NULL;
1272
1273 retval = sctp_make_control(asoc, SCTP_CID_AUTH, 0,
1274 hmac_desc->hmac_len + sizeof(sctp_authhdr_t));
1275 if (!retval)
1276 return NULL;
1277
1278 auth_hdr.hmac_id = htons(hmac_desc->hmac_id);
1279 auth_hdr.shkey_id = htons(asoc->active_key_id);
1280
1281 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(sctp_authhdr_t),
1282 &auth_hdr);
1283
1284 hmac = skb_put(retval->skb, hmac_desc->hmac_len);
1285 memset(hmac, 0, hmac_desc->hmac_len);
1286
1287 /* Adjust the chunk header to include the empty MAC */
1288 retval->chunk_hdr->length =
1289 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len);
1290 retval->chunk_end = skb_tail_pointer(retval->skb);
1291
1292 return retval;
1293}
1294
1295
1296/********************************************************************
1297 * 2nd Level Abstractions
1298 ********************************************************************/
1299
1300/* Turn an skb into a chunk.
1301 * FIXME: Eventually move the structure directly inside the skb->cb[].
1302 *
1303 * sctpimpguide-05.txt Section 2.8.2
1304 * M1) Each time a new DATA chunk is transmitted
1305 * set the 'TSN.Missing.Report' count for that TSN to 0. The
1306 * 'TSN.Missing.Report' count will be used to determine missing chunks
1307 * and when to fast retransmit.
1308 *
1309 */
1310struct sctp_chunk *sctp_chunkify(struct sk_buff *skb,
1311 const struct sctp_association *asoc,
1312 struct sock *sk)
1313{
1314 struct sctp_chunk *retval;
1315
1316 retval = kmem_cache_zalloc(sctp_chunk_cachep, GFP_ATOMIC);
1317
1318 if (!retval)
1319 goto nodata;
1320 if (!sk)
1321 pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb);
1322
1323 INIT_LIST_HEAD(&retval->list);
1324 retval->skb = skb;
1325 retval->asoc = (struct sctp_association *)asoc;
1326 retval->singleton = 1;
1327
1328 retval->fast_retransmit = SCTP_CAN_FRTX;
1329
1330 /* Polish the bead hole. */
1331 INIT_LIST_HEAD(&retval->transmitted_list);
1332 INIT_LIST_HEAD(&retval->frag_list);
1333 SCTP_DBG_OBJCNT_INC(chunk);
1334 atomic_set(&retval->refcnt, 1);
1335
1336nodata:
1337 return retval;
1338}
1339
1340/* Set chunk->source and dest based on the IP header in chunk->skb. */
1341void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src,
1342 union sctp_addr *dest)
1343{
1344 memcpy(&chunk->source, src, sizeof(union sctp_addr));
1345 memcpy(&chunk->dest, dest, sizeof(union sctp_addr));
1346}
1347
1348/* Extract the source address from a chunk. */
1349const union sctp_addr *sctp_source(const struct sctp_chunk *chunk)
1350{
1351 /* If we have a known transport, use that. */
1352 if (chunk->transport) {
1353 return &chunk->transport->ipaddr;
1354 } else {
1355 /* Otherwise, extract it from the IP header. */
1356 return &chunk->source;
1357 }
1358}
1359
1360/* Create a new chunk, setting the type and flags headers from the
1361 * arguments, reserving enough space for a 'paylen' byte payload.
1362 */
1363static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc,
1364 __u8 type, __u8 flags, int paylen)
1365{
1366 struct sctp_chunk *retval;
1367 sctp_chunkhdr_t *chunk_hdr;
1368 struct sk_buff *skb;
1369 struct sock *sk;
1370
1371 /* No need to allocate LL here, as this is only a chunk. */
1372 skb = alloc_skb(WORD_ROUND(sizeof(sctp_chunkhdr_t) + paylen),
1373 GFP_ATOMIC);
1374 if (!skb)
1375 goto nodata;
1376
1377 /* Make room for the chunk header. */
1378 chunk_hdr = (sctp_chunkhdr_t *)skb_put(skb, sizeof(sctp_chunkhdr_t));
1379 chunk_hdr->type = type;
1380 chunk_hdr->flags = flags;
1381 chunk_hdr->length = htons(sizeof(sctp_chunkhdr_t));
1382
1383 sk = asoc ? asoc->base.sk : NULL;
1384 retval = sctp_chunkify(skb, asoc, sk);
1385 if (!retval) {
1386 kfree_skb(skb);
1387 goto nodata;
1388 }
1389
1390 retval->chunk_hdr = chunk_hdr;
1391 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(struct sctp_chunkhdr);
1392
1393 /* Determine if the chunk needs to be authenticated */
1394 if (sctp_auth_send_cid(type, asoc))
1395 retval->auth = 1;
1396
1397 return retval;
1398nodata:
1399 return NULL;
1400}
1401
1402static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc,
1403 __u8 flags, int paylen)
1404{
1405 return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen);
1406}
1407
1408static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc,
1409 __u8 type, __u8 flags, int paylen)
1410{
1411 struct sctp_chunk *chunk = _sctp_make_chunk(asoc, type, flags, paylen);
1412
1413 if (chunk)
1414 sctp_control_set_owner_w(chunk);
1415
1416 return chunk;
1417}
1418
1419/* Release the memory occupied by a chunk. */
1420static void sctp_chunk_destroy(struct sctp_chunk *chunk)
1421{
1422 BUG_ON(!list_empty(&chunk->list));
1423 list_del_init(&chunk->transmitted_list);
1424
1425 consume_skb(chunk->skb);
1426 consume_skb(chunk->auth_chunk);
1427
1428 SCTP_DBG_OBJCNT_DEC(chunk);
1429 kmem_cache_free(sctp_chunk_cachep, chunk);
1430}
1431
1432/* Possibly, free the chunk. */
1433void sctp_chunk_free(struct sctp_chunk *chunk)
1434{
1435 /* Release our reference on the message tracker. */
1436 if (chunk->msg)
1437 sctp_datamsg_put(chunk->msg);
1438
1439 sctp_chunk_put(chunk);
1440}
1441
1442/* Grab a reference to the chunk. */
1443void sctp_chunk_hold(struct sctp_chunk *ch)
1444{
1445 atomic_inc(&ch->refcnt);
1446}
1447
1448/* Release a reference to the chunk. */
1449void sctp_chunk_put(struct sctp_chunk *ch)
1450{
1451 if (atomic_dec_and_test(&ch->refcnt))
1452 sctp_chunk_destroy(ch);
1453}
1454
1455/* Append bytes to the end of a chunk. Will panic if chunk is not big
1456 * enough.
1457 */
1458void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data)
1459{
1460 void *target;
1461 void *padding;
1462 int chunklen = ntohs(chunk->chunk_hdr->length);
1463 int padlen = WORD_ROUND(chunklen) - chunklen;
1464
1465 padding = skb_put(chunk->skb, padlen);
1466 target = skb_put(chunk->skb, len);
1467
1468 memset(padding, 0, padlen);
1469 memcpy(target, data, len);
1470
1471 /* Adjust the chunk length field. */
1472 chunk->chunk_hdr->length = htons(chunklen + padlen + len);
1473 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1474
1475 return target;
1476}
1477
1478/* Append bytes to the end of a chunk. Returns NULL if there isn't sufficient
1479 * space in the chunk
1480 */
1481static void *sctp_addto_chunk_fixed(struct sctp_chunk *chunk,
1482 int len, const void *data)
1483{
1484 if (skb_tailroom(chunk->skb) >= len)
1485 return sctp_addto_chunk(chunk, len, data);
1486 else
1487 return NULL;
1488}
1489
1490/* Append bytes from user space to the end of a chunk. Will panic if
1491 * chunk is not big enough.
1492 * Returns a kernel err value.
1493 */
1494int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len,
1495 struct iovec *data)
1496{
1497 __u8 *target;
1498 int err = 0;
1499
1500 /* Make room in chunk for data. */
1501 target = skb_put(chunk->skb, len);
1502
1503 /* Copy data (whole iovec) into chunk */
1504 if ((err = memcpy_fromiovecend(target, data, off, len)))
1505 goto out;
1506
1507 /* Adjust the chunk length field. */
1508 chunk->chunk_hdr->length =
1509 htons(ntohs(chunk->chunk_hdr->length) + len);
1510 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1511
1512out:
1513 return err;
1514}
1515
1516/* Helper function to assign a TSN if needed. This assumes that both
1517 * the data_hdr and association have already been assigned.
1518 */
1519void sctp_chunk_assign_ssn(struct sctp_chunk *chunk)
1520{
1521 struct sctp_datamsg *msg;
1522 struct sctp_chunk *lchunk;
1523 struct sctp_stream *stream;
1524 __u16 ssn;
1525 __u16 sid;
1526
1527 if (chunk->has_ssn)
1528 return;
1529
1530 /* All fragments will be on the same stream */
1531 sid = ntohs(chunk->subh.data_hdr->stream);
1532 stream = &chunk->asoc->ssnmap->out;
1533
1534 /* Now assign the sequence number to the entire message.
1535 * All fragments must have the same stream sequence number.
1536 */
1537 msg = chunk->msg;
1538 list_for_each_entry(lchunk, &msg->chunks, frag_list) {
1539 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
1540 ssn = 0;
1541 } else {
1542 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG)
1543 ssn = sctp_ssn_next(stream, sid);
1544 else
1545 ssn = sctp_ssn_peek(stream, sid);
1546 }
1547
1548 lchunk->subh.data_hdr->ssn = htons(ssn);
1549 lchunk->has_ssn = 1;
1550 }
1551}
1552
1553/* Helper function to assign a TSN if needed. This assumes that both
1554 * the data_hdr and association have already been assigned.
1555 */
1556void sctp_chunk_assign_tsn(struct sctp_chunk *chunk)
1557{
1558 if (!chunk->has_tsn) {
1559 /* This is the last possible instant to
1560 * assign a TSN.
1561 */
1562 chunk->subh.data_hdr->tsn =
1563 htonl(sctp_association_get_next_tsn(chunk->asoc));
1564 chunk->has_tsn = 1;
1565 }
1566}
1567
1568/* Create a CLOSED association to use with an incoming packet. */
1569struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep,
1570 struct sctp_chunk *chunk,
1571 gfp_t gfp)
1572{
1573 struct sctp_association *asoc;
1574 struct sk_buff *skb;
1575 sctp_scope_t scope;
1576 struct sctp_af *af;
1577
1578 /* Create the bare association. */
1579 scope = sctp_scope(sctp_source(chunk));
1580 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp);
1581 if (!asoc)
1582 goto nodata;
1583 asoc->temp = 1;
1584 skb = chunk->skb;
1585 /* Create an entry for the source address of the packet. */
1586 af = sctp_get_af_specific(ipver2af(ip_hdr(skb)->version));
1587 if (unlikely(!af))
1588 goto fail;
1589 af->from_skb(&asoc->c.peer_addr, skb, 1);
1590nodata:
1591 return asoc;
1592
1593fail:
1594 sctp_association_free(asoc);
1595 return NULL;
1596}
1597
1598/* Build a cookie representing asoc.
1599 * This INCLUDES the param header needed to put the cookie in the INIT ACK.
1600 */
1601static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep,
1602 const struct sctp_association *asoc,
1603 const struct sctp_chunk *init_chunk,
1604 int *cookie_len,
1605 const __u8 *raw_addrs, int addrs_len)
1606{
1607 sctp_cookie_param_t *retval;
1608 struct sctp_signed_cookie *cookie;
1609 struct scatterlist sg;
1610 int headersize, bodysize;
1611
1612 /* Header size is static data prior to the actual cookie, including
1613 * any padding.
1614 */
1615 headersize = sizeof(sctp_paramhdr_t) +
1616 (sizeof(struct sctp_signed_cookie) -
1617 sizeof(struct sctp_cookie));
1618 bodysize = sizeof(struct sctp_cookie)
1619 + ntohs(init_chunk->chunk_hdr->length) + addrs_len;
1620
1621 /* Pad out the cookie to a multiple to make the signature
1622 * functions simpler to write.
1623 */
1624 if (bodysize % SCTP_COOKIE_MULTIPLE)
1625 bodysize += SCTP_COOKIE_MULTIPLE
1626 - (bodysize % SCTP_COOKIE_MULTIPLE);
1627 *cookie_len = headersize + bodysize;
1628
1629 /* Clear this memory since we are sending this data structure
1630 * out on the network.
1631 */
1632 retval = kzalloc(*cookie_len, GFP_ATOMIC);
1633 if (!retval)
1634 goto nodata;
1635
1636 cookie = (struct sctp_signed_cookie *) retval->body;
1637
1638 /* Set up the parameter header. */
1639 retval->p.type = SCTP_PARAM_STATE_COOKIE;
1640 retval->p.length = htons(*cookie_len);
1641
1642 /* Copy the cookie part of the association itself. */
1643 cookie->c = asoc->c;
1644 /* Save the raw address list length in the cookie. */
1645 cookie->c.raw_addr_list_len = addrs_len;
1646
1647 /* Remember PR-SCTP capability. */
1648 cookie->c.prsctp_capable = asoc->peer.prsctp_capable;
1649
1650 /* Save adaptation indication in the cookie. */
1651 cookie->c.adaptation_ind = asoc->peer.adaptation_ind;
1652
1653 /* Set an expiration time for the cookie. */
1654 cookie->c.expiration = ktime_add(asoc->cookie_life,
1655 ktime_get());
1656
1657 /* Copy the peer's init packet. */
1658 memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr,
1659 ntohs(init_chunk->chunk_hdr->length));
1660
1661 /* Copy the raw local address list of the association. */
1662 memcpy((__u8 *)&cookie->c.peer_init[0] +
1663 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len);
1664
1665 if (sctp_sk(ep->base.sk)->hmac) {
1666 struct hash_desc desc;
1667
1668 /* Sign the message. */
1669 sg_init_one(&sg, &cookie->c, bodysize);
1670 desc.tfm = sctp_sk(ep->base.sk)->hmac;
1671 desc.flags = 0;
1672
1673 if (crypto_hash_setkey(desc.tfm, ep->secret_key,
1674 sizeof(ep->secret_key)) ||
1675 crypto_hash_digest(&desc, &sg, bodysize, cookie->signature))
1676 goto free_cookie;
1677 }
1678
1679 return retval;
1680
1681free_cookie:
1682 kfree(retval);
1683nodata:
1684 *cookie_len = 0;
1685 return NULL;
1686}
1687
1688/* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */
1689struct sctp_association *sctp_unpack_cookie(
1690 const struct sctp_endpoint *ep,
1691 const struct sctp_association *asoc,
1692 struct sctp_chunk *chunk, gfp_t gfp,
1693 int *error, struct sctp_chunk **errp)
1694{
1695 struct sctp_association *retval = NULL;
1696 struct sctp_signed_cookie *cookie;
1697 struct sctp_cookie *bear_cookie;
1698 int headersize, bodysize, fixed_size;
1699 __u8 *digest = ep->digest;
1700 struct scatterlist sg;
1701 unsigned int len;
1702 sctp_scope_t scope;
1703 struct sk_buff *skb = chunk->skb;
1704 ktime_t kt;
1705 struct hash_desc desc;
1706
1707 /* Header size is static data prior to the actual cookie, including
1708 * any padding.
1709 */
1710 headersize = sizeof(sctp_chunkhdr_t) +
1711 (sizeof(struct sctp_signed_cookie) -
1712 sizeof(struct sctp_cookie));
1713 bodysize = ntohs(chunk->chunk_hdr->length) - headersize;
1714 fixed_size = headersize + sizeof(struct sctp_cookie);
1715
1716 /* Verify that the chunk looks like it even has a cookie.
1717 * There must be enough room for our cookie and our peer's
1718 * INIT chunk.
1719 */
1720 len = ntohs(chunk->chunk_hdr->length);
1721 if (len < fixed_size + sizeof(struct sctp_chunkhdr))
1722 goto malformed;
1723
1724 /* Verify that the cookie has been padded out. */
1725 if (bodysize % SCTP_COOKIE_MULTIPLE)
1726 goto malformed;
1727
1728 /* Process the cookie. */
1729 cookie = chunk->subh.cookie_hdr;
1730 bear_cookie = &cookie->c;
1731
1732 if (!sctp_sk(ep->base.sk)->hmac)
1733 goto no_hmac;
1734
1735 /* Check the signature. */
1736 sg_init_one(&sg, bear_cookie, bodysize);
1737 desc.tfm = sctp_sk(ep->base.sk)->hmac;
1738 desc.flags = 0;
1739
1740 memset(digest, 0x00, SCTP_SIGNATURE_SIZE);
1741 if (crypto_hash_setkey(desc.tfm, ep->secret_key,
1742 sizeof(ep->secret_key)) ||
1743 crypto_hash_digest(&desc, &sg, bodysize, digest)) {
1744 *error = -SCTP_IERROR_NOMEM;
1745 goto fail;
1746 }
1747
1748 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
1749 *error = -SCTP_IERROR_BAD_SIG;
1750 goto fail;
1751 }
1752
1753no_hmac:
1754 /* IG Section 2.35.2:
1755 * 3) Compare the port numbers and the verification tag contained
1756 * within the COOKIE ECHO chunk to the actual port numbers and the
1757 * verification tag within the SCTP common header of the received
1758 * packet. If these values do not match the packet MUST be silently
1759 * discarded,
1760 */
1761 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) {
1762 *error = -SCTP_IERROR_BAD_TAG;
1763 goto fail;
1764 }
1765
1766 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port ||
1767 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) {
1768 *error = -SCTP_IERROR_BAD_PORTS;
1769 goto fail;
1770 }
1771
1772 /* Check to see if the cookie is stale. If there is already
1773 * an association, there is no need to check cookie's expiration
1774 * for init collision case of lost COOKIE ACK.
1775 * If skb has been timestamped, then use the stamp, otherwise
1776 * use current time. This introduces a small possibility that
1777 * that a cookie may be considered expired, but his would only slow
1778 * down the new association establishment instead of every packet.
1779 */
1780 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP))
1781 kt = skb_get_ktime(skb);
1782 else
1783 kt = ktime_get();
1784
1785 if (!asoc && ktime_compare(bear_cookie->expiration, kt) < 0) {
1786 /*
1787 * Section 3.3.10.3 Stale Cookie Error (3)
1788 *
1789 * Cause of error
1790 * ---------------
1791 * Stale Cookie Error: Indicates the receipt of a valid State
1792 * Cookie that has expired.
1793 */
1794 len = ntohs(chunk->chunk_hdr->length);
1795 *errp = sctp_make_op_error_space(asoc, chunk, len);
1796 if (*errp) {
1797 suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration));
1798 __be32 n = htonl(usecs);
1799
1800 sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE,
1801 sizeof(n));
1802 sctp_addto_chunk(*errp, sizeof(n), &n);
1803 *error = -SCTP_IERROR_STALE_COOKIE;
1804 } else
1805 *error = -SCTP_IERROR_NOMEM;
1806
1807 goto fail;
1808 }
1809
1810 /* Make a new base association. */
1811 scope = sctp_scope(sctp_source(chunk));
1812 retval = sctp_association_new(ep, ep->base.sk, scope, gfp);
1813 if (!retval) {
1814 *error = -SCTP_IERROR_NOMEM;
1815 goto fail;
1816 }
1817
1818 /* Set up our peer's port number. */
1819 retval->peer.port = ntohs(chunk->sctp_hdr->source);
1820
1821 /* Populate the association from the cookie. */
1822 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie));
1823
1824 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie,
1825 GFP_ATOMIC) < 0) {
1826 *error = -SCTP_IERROR_NOMEM;
1827 goto fail;
1828 }
1829
1830 /* Also, add the destination address. */
1831 if (list_empty(&retval->base.bind_addr.address_list)) {
1832 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest,
1833 SCTP_ADDR_SRC, GFP_ATOMIC);
1834 }
1835
1836 retval->next_tsn = retval->c.initial_tsn;
1837 retval->ctsn_ack_point = retval->next_tsn - 1;
1838 retval->addip_serial = retval->c.initial_tsn;
1839 retval->adv_peer_ack_point = retval->ctsn_ack_point;
1840 retval->peer.prsctp_capable = retval->c.prsctp_capable;
1841 retval->peer.adaptation_ind = retval->c.adaptation_ind;
1842
1843 /* The INIT stuff will be done by the side effects. */
1844 return retval;
1845
1846fail:
1847 if (retval)
1848 sctp_association_free(retval);
1849
1850 return NULL;
1851
1852malformed:
1853 /* Yikes! The packet is either corrupt or deliberately
1854 * malformed.
1855 */
1856 *error = -SCTP_IERROR_MALFORMED;
1857 goto fail;
1858}
1859
1860/********************************************************************
1861 * 3rd Level Abstractions
1862 ********************************************************************/
1863
1864struct __sctp_missing {
1865 __be32 num_missing;
1866 __be16 type;
1867} __packed;
1868
1869/*
1870 * Report a missing mandatory parameter.
1871 */
1872static int sctp_process_missing_param(const struct sctp_association *asoc,
1873 sctp_param_t paramtype,
1874 struct sctp_chunk *chunk,
1875 struct sctp_chunk **errp)
1876{
1877 struct __sctp_missing report;
1878 __u16 len;
1879
1880 len = WORD_ROUND(sizeof(report));
1881
1882 /* Make an ERROR chunk, preparing enough room for
1883 * returning multiple unknown parameters.
1884 */
1885 if (!*errp)
1886 *errp = sctp_make_op_error_space(asoc, chunk, len);
1887
1888 if (*errp) {
1889 report.num_missing = htonl(1);
1890 report.type = paramtype;
1891 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM,
1892 sizeof(report));
1893 sctp_addto_chunk(*errp, sizeof(report), &report);
1894 }
1895
1896 /* Stop processing this chunk. */
1897 return 0;
1898}
1899
1900/* Report an Invalid Mandatory Parameter. */
1901static int sctp_process_inv_mandatory(const struct sctp_association *asoc,
1902 struct sctp_chunk *chunk,
1903 struct sctp_chunk **errp)
1904{
1905 /* Invalid Mandatory Parameter Error has no payload. */
1906
1907 if (!*errp)
1908 *errp = sctp_make_op_error_space(asoc, chunk, 0);
1909
1910 if (*errp)
1911 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0);
1912
1913 /* Stop processing this chunk. */
1914 return 0;
1915}
1916
1917static int sctp_process_inv_paramlength(const struct sctp_association *asoc,
1918 struct sctp_paramhdr *param,
1919 const struct sctp_chunk *chunk,
1920 struct sctp_chunk **errp)
1921{
1922 /* This is a fatal error. Any accumulated non-fatal errors are
1923 * not reported.
1924 */
1925 if (*errp)
1926 sctp_chunk_free(*errp);
1927
1928 /* Create an error chunk and fill it in with our payload. */
1929 *errp = sctp_make_violation_paramlen(asoc, chunk, param);
1930
1931 return 0;
1932}
1933
1934
1935/* Do not attempt to handle the HOST_NAME parm. However, do
1936 * send back an indicator to the peer.
1937 */
1938static int sctp_process_hn_param(const struct sctp_association *asoc,
1939 union sctp_params param,
1940 struct sctp_chunk *chunk,
1941 struct sctp_chunk **errp)
1942{
1943 __u16 len = ntohs(param.p->length);
1944
1945 /* Processing of the HOST_NAME parameter will generate an
1946 * ABORT. If we've accumulated any non-fatal errors, they
1947 * would be unrecognized parameters and we should not include
1948 * them in the ABORT.
1949 */
1950 if (*errp)
1951 sctp_chunk_free(*errp);
1952
1953 *errp = sctp_make_op_error_space(asoc, chunk, len);
1954
1955 if (*errp) {
1956 sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, len);
1957 sctp_addto_chunk(*errp, len, param.v);
1958 }
1959
1960 /* Stop processing this chunk. */
1961 return 0;
1962}
1963
1964static int sctp_verify_ext_param(struct net *net, union sctp_params param)
1965{
1966 __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
1967 int have_auth = 0;
1968 int have_asconf = 0;
1969 int i;
1970
1971 for (i = 0; i < num_ext; i++) {
1972 switch (param.ext->chunks[i]) {
1973 case SCTP_CID_AUTH:
1974 have_auth = 1;
1975 break;
1976 case SCTP_CID_ASCONF:
1977 case SCTP_CID_ASCONF_ACK:
1978 have_asconf = 1;
1979 break;
1980 }
1981 }
1982
1983 /* ADD-IP Security: The draft requires us to ABORT or ignore the
1984 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this
1985 * only if ADD-IP is turned on and we are not backward-compatible
1986 * mode.
1987 */
1988 if (net->sctp.addip_noauth)
1989 return 1;
1990
1991 if (net->sctp.addip_enable && !have_auth && have_asconf)
1992 return 0;
1993
1994 return 1;
1995}
1996
1997static void sctp_process_ext_param(struct sctp_association *asoc,
1998 union sctp_params param)
1999{
2000 struct net *net = sock_net(asoc->base.sk);
2001 __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
2002 int i;
2003
2004 for (i = 0; i < num_ext; i++) {
2005 switch (param.ext->chunks[i]) {
2006 case SCTP_CID_FWD_TSN:
2007 if (net->sctp.prsctp_enable && !asoc->peer.prsctp_capable)
2008 asoc->peer.prsctp_capable = 1;
2009 break;
2010 case SCTP_CID_AUTH:
2011 /* if the peer reports AUTH, assume that he
2012 * supports AUTH.
2013 */
2014 if (asoc->ep->auth_enable)
2015 asoc->peer.auth_capable = 1;
2016 break;
2017 case SCTP_CID_ASCONF:
2018 case SCTP_CID_ASCONF_ACK:
2019 if (net->sctp.addip_enable)
2020 asoc->peer.asconf_capable = 1;
2021 break;
2022 default:
2023 break;
2024 }
2025 }
2026}
2027
2028/* RFC 3.2.1 & the Implementers Guide 2.2.
2029 *
2030 * The Parameter Types are encoded such that the
2031 * highest-order two bits specify the action that must be
2032 * taken if the processing endpoint does not recognize the
2033 * Parameter Type.
2034 *
2035 * 00 - Stop processing this parameter; do not process any further
2036 * parameters within this chunk
2037 *
2038 * 01 - Stop processing this parameter, do not process any further
2039 * parameters within this chunk, and report the unrecognized
2040 * parameter in an 'Unrecognized Parameter' ERROR chunk.
2041 *
2042 * 10 - Skip this parameter and continue processing.
2043 *
2044 * 11 - Skip this parameter and continue processing but
2045 * report the unrecognized parameter in an
2046 * 'Unrecognized Parameter' ERROR chunk.
2047 *
2048 * Return value:
2049 * SCTP_IERROR_NO_ERROR - continue with the chunk
2050 * SCTP_IERROR_ERROR - stop and report an error.
2051 * SCTP_IERROR_NOMEME - out of memory.
2052 */
2053static sctp_ierror_t sctp_process_unk_param(const struct sctp_association *asoc,
2054 union sctp_params param,
2055 struct sctp_chunk *chunk,
2056 struct sctp_chunk **errp)
2057{
2058 int retval = SCTP_IERROR_NO_ERROR;
2059
2060 switch (param.p->type & SCTP_PARAM_ACTION_MASK) {
2061 case SCTP_PARAM_ACTION_DISCARD:
2062 retval = SCTP_IERROR_ERROR;
2063 break;
2064 case SCTP_PARAM_ACTION_SKIP:
2065 break;
2066 case SCTP_PARAM_ACTION_DISCARD_ERR:
2067 retval = SCTP_IERROR_ERROR;
2068 /* Fall through */
2069 case SCTP_PARAM_ACTION_SKIP_ERR:
2070 /* Make an ERROR chunk, preparing enough room for
2071 * returning multiple unknown parameters.
2072 */
2073 if (NULL == *errp)
2074 *errp = sctp_make_op_error_fixed(asoc, chunk);
2075
2076 if (*errp) {
2077 if (!sctp_init_cause_fixed(*errp, SCTP_ERROR_UNKNOWN_PARAM,
2078 WORD_ROUND(ntohs(param.p->length))))
2079 sctp_addto_chunk_fixed(*errp,
2080 WORD_ROUND(ntohs(param.p->length)),
2081 param.v);
2082 } else {
2083 /* If there is no memory for generating the ERROR
2084 * report as specified, an ABORT will be triggered
2085 * to the peer and the association won't be
2086 * established.
2087 */
2088 retval = SCTP_IERROR_NOMEM;
2089 }
2090 break;
2091 default:
2092 break;
2093 }
2094
2095 return retval;
2096}
2097
2098/* Verify variable length parameters
2099 * Return values:
2100 * SCTP_IERROR_ABORT - trigger an ABORT
2101 * SCTP_IERROR_NOMEM - out of memory (abort)
2102 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR
2103 * SCTP_IERROR_NO_ERROR - continue with the chunk
2104 */
2105static sctp_ierror_t sctp_verify_param(struct net *net,
2106 const struct sctp_endpoint *ep,
2107 const struct sctp_association *asoc,
2108 union sctp_params param,
2109 sctp_cid_t cid,
2110 struct sctp_chunk *chunk,
2111 struct sctp_chunk **err_chunk)
2112{
2113 struct sctp_hmac_algo_param *hmacs;
2114 int retval = SCTP_IERROR_NO_ERROR;
2115 __u16 n_elt, id = 0;
2116 int i;
2117
2118 /* FIXME - This routine is not looking at each parameter per the
2119 * chunk type, i.e., unrecognized parameters should be further
2120 * identified based on the chunk id.
2121 */
2122
2123 switch (param.p->type) {
2124 case SCTP_PARAM_IPV4_ADDRESS:
2125 case SCTP_PARAM_IPV6_ADDRESS:
2126 case SCTP_PARAM_COOKIE_PRESERVATIVE:
2127 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
2128 case SCTP_PARAM_STATE_COOKIE:
2129 case SCTP_PARAM_HEARTBEAT_INFO:
2130 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
2131 case SCTP_PARAM_ECN_CAPABLE:
2132 case SCTP_PARAM_ADAPTATION_LAYER_IND:
2133 break;
2134
2135 case SCTP_PARAM_SUPPORTED_EXT:
2136 if (!sctp_verify_ext_param(net, param))
2137 return SCTP_IERROR_ABORT;
2138 break;
2139
2140 case SCTP_PARAM_SET_PRIMARY:
2141 if (net->sctp.addip_enable)
2142 break;
2143 goto fallthrough;
2144
2145 case SCTP_PARAM_HOST_NAME_ADDRESS:
2146 /* Tell the peer, we won't support this param. */
2147 sctp_process_hn_param(asoc, param, chunk, err_chunk);
2148 retval = SCTP_IERROR_ABORT;
2149 break;
2150
2151 case SCTP_PARAM_FWD_TSN_SUPPORT:
2152 if (net->sctp.prsctp_enable)
2153 break;
2154 goto fallthrough;
2155
2156 case SCTP_PARAM_RANDOM:
2157 if (!ep->auth_enable)
2158 goto fallthrough;
2159
2160 /* SCTP-AUTH: Secion 6.1
2161 * If the random number is not 32 byte long the association
2162 * MUST be aborted. The ABORT chunk SHOULD contain the error
2163 * cause 'Protocol Violation'.
2164 */
2165 if (SCTP_AUTH_RANDOM_LENGTH !=
2166 ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) {
2167 sctp_process_inv_paramlength(asoc, param.p,
2168 chunk, err_chunk);
2169 retval = SCTP_IERROR_ABORT;
2170 }
2171 break;
2172
2173 case SCTP_PARAM_CHUNKS:
2174 if (!ep->auth_enable)
2175 goto fallthrough;
2176
2177 /* SCTP-AUTH: Section 3.2
2178 * The CHUNKS parameter MUST be included once in the INIT or
2179 * INIT-ACK chunk if the sender wants to receive authenticated
2180 * chunks. Its maximum length is 260 bytes.
2181 */
2182 if (260 < ntohs(param.p->length)) {
2183 sctp_process_inv_paramlength(asoc, param.p,
2184 chunk, err_chunk);
2185 retval = SCTP_IERROR_ABORT;
2186 }
2187 break;
2188
2189 case SCTP_PARAM_HMAC_ALGO:
2190 if (!ep->auth_enable)
2191 goto fallthrough;
2192
2193 hmacs = (struct sctp_hmac_algo_param *)param.p;
2194 n_elt = (ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) >> 1;
2195
2196 /* SCTP-AUTH: Section 6.1
2197 * The HMAC algorithm based on SHA-1 MUST be supported and
2198 * included in the HMAC-ALGO parameter.
2199 */
2200 for (i = 0; i < n_elt; i++) {
2201 id = ntohs(hmacs->hmac_ids[i]);
2202
2203 if (id == SCTP_AUTH_HMAC_ID_SHA1)
2204 break;
2205 }
2206
2207 if (id != SCTP_AUTH_HMAC_ID_SHA1) {
2208 sctp_process_inv_paramlength(asoc, param.p, chunk,
2209 err_chunk);
2210 retval = SCTP_IERROR_ABORT;
2211 }
2212 break;
2213fallthrough:
2214 default:
2215 pr_debug("%s: unrecognized param:%d for chunk:%d\n",
2216 __func__, ntohs(param.p->type), cid);
2217
2218 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk);
2219 break;
2220 }
2221 return retval;
2222}
2223
2224/* Verify the INIT packet before we process it. */
2225int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
2226 const struct sctp_association *asoc, sctp_cid_t cid,
2227 sctp_init_chunk_t *peer_init, struct sctp_chunk *chunk,
2228 struct sctp_chunk **errp)
2229{
2230 union sctp_params param;
2231 bool has_cookie = false;
2232 int result;
2233
2234 /* Check for missing mandatory parameters. Note: Initial TSN is
2235 * also mandatory, but is not checked here since the valid range
2236 * is 0..2**32-1. RFC4960, section 3.3.3.
2237 */
2238 if (peer_init->init_hdr.num_outbound_streams == 0 ||
2239 peer_init->init_hdr.num_inbound_streams == 0 ||
2240 peer_init->init_hdr.init_tag == 0 ||
2241 ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW)
2242 return sctp_process_inv_mandatory(asoc, chunk, errp);
2243
2244 sctp_walk_params(param, peer_init, init_hdr.params) {
2245 if (param.p->type == SCTP_PARAM_STATE_COOKIE)
2246 has_cookie = true;
2247 }
2248
2249 /* There is a possibility that a parameter length was bad and
2250 * in that case we would have stoped walking the parameters.
2251 * The current param.p would point at the bad one.
2252 * Current consensus on the mailing list is to generate a PROTOCOL
2253 * VIOLATION error. We build the ERROR chunk here and let the normal
2254 * error handling code build and send the packet.
2255 */
2256 if (param.v != (void *)chunk->chunk_end)
2257 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp);
2258
2259 /* The only missing mandatory param possible today is
2260 * the state cookie for an INIT-ACK chunk.
2261 */
2262 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie)
2263 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE,
2264 chunk, errp);
2265
2266 /* Verify all the variable length parameters */
2267 sctp_walk_params(param, peer_init, init_hdr.params) {
2268 result = sctp_verify_param(net, ep, asoc, param, cid,
2269 chunk, errp);
2270 switch (result) {
2271 case SCTP_IERROR_ABORT:
2272 case SCTP_IERROR_NOMEM:
2273 return 0;
2274 case SCTP_IERROR_ERROR:
2275 return 1;
2276 case SCTP_IERROR_NO_ERROR:
2277 default:
2278 break;
2279 }
2280
2281 } /* for (loop through all parameters) */
2282
2283 return 1;
2284}
2285
2286/* Unpack the parameters in an INIT packet into an association.
2287 * Returns 0 on failure, else success.
2288 * FIXME: This is an association method.
2289 */
2290int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk,
2291 const union sctp_addr *peer_addr,
2292 sctp_init_chunk_t *peer_init, gfp_t gfp)
2293{
2294 struct net *net = sock_net(asoc->base.sk);
2295 union sctp_params param;
2296 struct sctp_transport *transport;
2297 struct list_head *pos, *temp;
2298 struct sctp_af *af;
2299 union sctp_addr addr;
2300 char *cookie;
2301 int src_match = 0;
2302
2303 /* We must include the address that the INIT packet came from.
2304 * This is the only address that matters for an INIT packet.
2305 * When processing a COOKIE ECHO, we retrieve the from address
2306 * of the INIT from the cookie.
2307 */
2308
2309 /* This implementation defaults to making the first transport
2310 * added as the primary transport. The source address seems to
2311 * be a a better choice than any of the embedded addresses.
2312 */
2313 if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE))
2314 goto nomem;
2315
2316 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr))
2317 src_match = 1;
2318
2319 /* Process the initialization parameters. */
2320 sctp_walk_params(param, peer_init, init_hdr.params) {
2321 if (!src_match && (param.p->type == SCTP_PARAM_IPV4_ADDRESS ||
2322 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) {
2323 af = sctp_get_af_specific(param_type2af(param.p->type));
2324 af->from_addr_param(&addr, param.addr,
2325 chunk->sctp_hdr->source, 0);
2326 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr))
2327 src_match = 1;
2328 }
2329
2330 if (!sctp_process_param(asoc, param, peer_addr, gfp))
2331 goto clean_up;
2332 }
2333
2334 /* source address of chunk may not match any valid address */
2335 if (!src_match)
2336 goto clean_up;
2337
2338 /* AUTH: After processing the parameters, make sure that we
2339 * have all the required info to potentially do authentications.
2340 */
2341 if (asoc->peer.auth_capable && (!asoc->peer.peer_random ||
2342 !asoc->peer.peer_hmacs))
2343 asoc->peer.auth_capable = 0;
2344
2345 /* In a non-backward compatible mode, if the peer claims
2346 * support for ADD-IP but not AUTH, the ADD-IP spec states
2347 * that we MUST ABORT the association. Section 6. The section
2348 * also give us an option to silently ignore the packet, which
2349 * is what we'll do here.
2350 */
2351 if (!net->sctp.addip_noauth &&
2352 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) {
2353 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP |
2354 SCTP_PARAM_DEL_IP |
2355 SCTP_PARAM_SET_PRIMARY);
2356 asoc->peer.asconf_capable = 0;
2357 goto clean_up;
2358 }
2359
2360 /* Walk list of transports, removing transports in the UNKNOWN state. */
2361 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
2362 transport = list_entry(pos, struct sctp_transport, transports);
2363 if (transport->state == SCTP_UNKNOWN) {
2364 sctp_assoc_rm_peer(asoc, transport);
2365 }
2366 }
2367
2368 /* The fixed INIT headers are always in network byte
2369 * order.
2370 */
2371 asoc->peer.i.init_tag =
2372 ntohl(peer_init->init_hdr.init_tag);
2373 asoc->peer.i.a_rwnd =
2374 ntohl(peer_init->init_hdr.a_rwnd);
2375 asoc->peer.i.num_outbound_streams =
2376 ntohs(peer_init->init_hdr.num_outbound_streams);
2377 asoc->peer.i.num_inbound_streams =
2378 ntohs(peer_init->init_hdr.num_inbound_streams);
2379 asoc->peer.i.initial_tsn =
2380 ntohl(peer_init->init_hdr.initial_tsn);
2381
2382 /* Apply the upper bounds for output streams based on peer's
2383 * number of inbound streams.
2384 */
2385 if (asoc->c.sinit_num_ostreams >
2386 ntohs(peer_init->init_hdr.num_inbound_streams)) {
2387 asoc->c.sinit_num_ostreams =
2388 ntohs(peer_init->init_hdr.num_inbound_streams);
2389 }
2390
2391 if (asoc->c.sinit_max_instreams >
2392 ntohs(peer_init->init_hdr.num_outbound_streams)) {
2393 asoc->c.sinit_max_instreams =
2394 ntohs(peer_init->init_hdr.num_outbound_streams);
2395 }
2396
2397 /* Copy Initiation tag from INIT to VT_peer in cookie. */
2398 asoc->c.peer_vtag = asoc->peer.i.init_tag;
2399
2400 /* Peer Rwnd : Current calculated value of the peer's rwnd. */
2401 asoc->peer.rwnd = asoc->peer.i.a_rwnd;
2402
2403 /* Copy cookie in case we need to resend COOKIE-ECHO. */
2404 cookie = asoc->peer.cookie;
2405 if (cookie) {
2406 asoc->peer.cookie = kmemdup(cookie, asoc->peer.cookie_len, gfp);
2407 if (!asoc->peer.cookie)
2408 goto clean_up;
2409 }
2410
2411 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily
2412 * high (for example, implementations MAY use the size of the receiver
2413 * advertised window).
2414 */
2415 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
2416 transports) {
2417 transport->ssthresh = asoc->peer.i.a_rwnd;
2418 }
2419
2420 /* Set up the TSN tracking pieces. */
2421 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
2422 asoc->peer.i.initial_tsn, gfp))
2423 goto clean_up;
2424
2425 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
2426 *
2427 * The stream sequence number in all the streams shall start
2428 * from 0 when the association is established. Also, when the
2429 * stream sequence number reaches the value 65535 the next
2430 * stream sequence number shall be set to 0.
2431 */
2432
2433 /* Allocate storage for the negotiated streams if it is not a temporary
2434 * association.
2435 */
2436 if (!asoc->temp) {
2437 int error;
2438
2439 asoc->ssnmap = sctp_ssnmap_new(asoc->c.sinit_max_instreams,
2440 asoc->c.sinit_num_ostreams, gfp);
2441 if (!asoc->ssnmap)
2442 goto clean_up;
2443
2444 error = sctp_assoc_set_id(asoc, gfp);
2445 if (error)
2446 goto clean_up;
2447 }
2448
2449 /* ADDIP Section 4.1 ASCONF Chunk Procedures
2450 *
2451 * When an endpoint has an ASCONF signaled change to be sent to the
2452 * remote endpoint it should do the following:
2453 * ...
2454 * A2) A serial number should be assigned to the Chunk. The serial
2455 * number should be a monotonically increasing number. All serial
2456 * numbers are defined to be initialized at the start of the
2457 * association to the same value as the Initial TSN.
2458 */
2459 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1;
2460 return 1;
2461
2462clean_up:
2463 /* Release the transport structures. */
2464 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
2465 transport = list_entry(pos, struct sctp_transport, transports);
2466 if (transport->state != SCTP_ACTIVE)
2467 sctp_assoc_rm_peer(asoc, transport);
2468 }
2469
2470nomem:
2471 return 0;
2472}
2473
2474
2475/* Update asoc with the option described in param.
2476 *
2477 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT
2478 *
2479 * asoc is the association to update.
2480 * param is the variable length parameter to use for update.
2481 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO.
2482 * If the current packet is an INIT we want to minimize the amount of
2483 * work we do. In particular, we should not build transport
2484 * structures for the addresses.
2485 */
2486static int sctp_process_param(struct sctp_association *asoc,
2487 union sctp_params param,
2488 const union sctp_addr *peer_addr,
2489 gfp_t gfp)
2490{
2491 struct net *net = sock_net(asoc->base.sk);
2492 union sctp_addr addr;
2493 int i;
2494 __u16 sat;
2495 int retval = 1;
2496 sctp_scope_t scope;
2497 time_t stale;
2498 struct sctp_af *af;
2499 union sctp_addr_param *addr_param;
2500 struct sctp_transport *t;
2501 struct sctp_endpoint *ep = asoc->ep;
2502
2503 /* We maintain all INIT parameters in network byte order all the
2504 * time. This allows us to not worry about whether the parameters
2505 * came from a fresh INIT, and INIT ACK, or were stored in a cookie.
2506 */
2507 switch (param.p->type) {
2508 case SCTP_PARAM_IPV6_ADDRESS:
2509 if (PF_INET6 != asoc->base.sk->sk_family)
2510 break;
2511 goto do_addr_param;
2512
2513 case SCTP_PARAM_IPV4_ADDRESS:
2514 /* v4 addresses are not allowed on v6-only socket */
2515 if (ipv6_only_sock(asoc->base.sk))
2516 break;
2517do_addr_param:
2518 af = sctp_get_af_specific(param_type2af(param.p->type));
2519 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0);
2520 scope = sctp_scope(peer_addr);
2521 if (sctp_in_scope(net, &addr, scope))
2522 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED))
2523 return 0;
2524 break;
2525
2526 case SCTP_PARAM_COOKIE_PRESERVATIVE:
2527 if (!net->sctp.cookie_preserve_enable)
2528 break;
2529
2530 stale = ntohl(param.life->lifespan_increment);
2531
2532 /* Suggested Cookie Life span increment's unit is msec,
2533 * (1/1000sec).
2534 */
2535 asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale);
2536 break;
2537
2538 case SCTP_PARAM_HOST_NAME_ADDRESS:
2539 pr_debug("%s: unimplemented SCTP_HOST_NAME_ADDRESS\n", __func__);
2540 break;
2541
2542 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
2543 /* Turn off the default values first so we'll know which
2544 * ones are really set by the peer.
2545 */
2546 asoc->peer.ipv4_address = 0;
2547 asoc->peer.ipv6_address = 0;
2548
2549 /* Assume that peer supports the address family
2550 * by which it sends a packet.
2551 */
2552 if (peer_addr->sa.sa_family == AF_INET6)
2553 asoc->peer.ipv6_address = 1;
2554 else if (peer_addr->sa.sa_family == AF_INET)
2555 asoc->peer.ipv4_address = 1;
2556
2557 /* Cycle through address types; avoid divide by 0. */
2558 sat = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
2559 if (sat)
2560 sat /= sizeof(__u16);
2561
2562 for (i = 0; i < sat; ++i) {
2563 switch (param.sat->types[i]) {
2564 case SCTP_PARAM_IPV4_ADDRESS:
2565 asoc->peer.ipv4_address = 1;
2566 break;
2567
2568 case SCTP_PARAM_IPV6_ADDRESS:
2569 if (PF_INET6 == asoc->base.sk->sk_family)
2570 asoc->peer.ipv6_address = 1;
2571 break;
2572
2573 case SCTP_PARAM_HOST_NAME_ADDRESS:
2574 asoc->peer.hostname_address = 1;
2575 break;
2576
2577 default: /* Just ignore anything else. */
2578 break;
2579 }
2580 }
2581 break;
2582
2583 case SCTP_PARAM_STATE_COOKIE:
2584 asoc->peer.cookie_len =
2585 ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
2586 asoc->peer.cookie = param.cookie->body;
2587 break;
2588
2589 case SCTP_PARAM_HEARTBEAT_INFO:
2590 /* Would be odd to receive, but it causes no problems. */
2591 break;
2592
2593 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
2594 /* Rejected during verify stage. */
2595 break;
2596
2597 case SCTP_PARAM_ECN_CAPABLE:
2598 asoc->peer.ecn_capable = 1;
2599 break;
2600
2601 case SCTP_PARAM_ADAPTATION_LAYER_IND:
2602 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind);
2603 break;
2604
2605 case SCTP_PARAM_SET_PRIMARY:
2606 if (!net->sctp.addip_enable)
2607 goto fall_through;
2608
2609 addr_param = param.v + sizeof(sctp_addip_param_t);
2610
2611 af = sctp_get_af_specific(param_type2af(param.p->type));
2612 af->from_addr_param(&addr, addr_param,
2613 htons(asoc->peer.port), 0);
2614
2615 /* if the address is invalid, we can't process it.
2616 * XXX: see spec for what to do.
2617 */
2618 if (!af->addr_valid(&addr, NULL, NULL))
2619 break;
2620
2621 t = sctp_assoc_lookup_paddr(asoc, &addr);
2622 if (!t)
2623 break;
2624
2625 sctp_assoc_set_primary(asoc, t);
2626 break;
2627
2628 case SCTP_PARAM_SUPPORTED_EXT:
2629 sctp_process_ext_param(asoc, param);
2630 break;
2631
2632 case SCTP_PARAM_FWD_TSN_SUPPORT:
2633 if (net->sctp.prsctp_enable) {
2634 asoc->peer.prsctp_capable = 1;
2635 break;
2636 }
2637 /* Fall Through */
2638 goto fall_through;
2639
2640 case SCTP_PARAM_RANDOM:
2641 if (!ep->auth_enable)
2642 goto fall_through;
2643
2644 /* Save peer's random parameter */
2645 asoc->peer.peer_random = kmemdup(param.p,
2646 ntohs(param.p->length), gfp);
2647 if (!asoc->peer.peer_random) {
2648 retval = 0;
2649 break;
2650 }
2651 break;
2652
2653 case SCTP_PARAM_HMAC_ALGO:
2654 if (!ep->auth_enable)
2655 goto fall_through;
2656
2657 /* Save peer's HMAC list */
2658 asoc->peer.peer_hmacs = kmemdup(param.p,
2659 ntohs(param.p->length), gfp);
2660 if (!asoc->peer.peer_hmacs) {
2661 retval = 0;
2662 break;
2663 }
2664
2665 /* Set the default HMAC the peer requested*/
2666 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo);
2667 break;
2668
2669 case SCTP_PARAM_CHUNKS:
2670 if (!ep->auth_enable)
2671 goto fall_through;
2672
2673 asoc->peer.peer_chunks = kmemdup(param.p,
2674 ntohs(param.p->length), gfp);
2675 if (!asoc->peer.peer_chunks)
2676 retval = 0;
2677 break;
2678fall_through:
2679 default:
2680 /* Any unrecognized parameters should have been caught
2681 * and handled by sctp_verify_param() which should be
2682 * called prior to this routine. Simply log the error
2683 * here.
2684 */
2685 pr_debug("%s: ignoring param:%d for association:%p.\n",
2686 __func__, ntohs(param.p->type), asoc);
2687 break;
2688 }
2689
2690 return retval;
2691}
2692
2693/* Select a new verification tag. */
2694__u32 sctp_generate_tag(const struct sctp_endpoint *ep)
2695{
2696 /* I believe that this random number generator complies with RFC1750.
2697 * A tag of 0 is reserved for special cases (e.g. INIT).
2698 */
2699 __u32 x;
2700
2701 do {
2702 get_random_bytes(&x, sizeof(__u32));
2703 } while (x == 0);
2704
2705 return x;
2706}
2707
2708/* Select an initial TSN to send during startup. */
2709__u32 sctp_generate_tsn(const struct sctp_endpoint *ep)
2710{
2711 __u32 retval;
2712
2713 get_random_bytes(&retval, sizeof(__u32));
2714 return retval;
2715}
2716
2717/*
2718 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF)
2719 * 0 1 2 3
2720 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2721 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2722 * | Type = 0xC1 | Chunk Flags | Chunk Length |
2723 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2724 * | Serial Number |
2725 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2726 * | Address Parameter |
2727 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2728 * | ASCONF Parameter #1 |
2729 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2730 * \ \
2731 * / .... /
2732 * \ \
2733 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2734 * | ASCONF Parameter #N |
2735 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2736 *
2737 * Address Parameter and other parameter will not be wrapped in this function
2738 */
2739static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc,
2740 union sctp_addr *addr,
2741 int vparam_len)
2742{
2743 sctp_addiphdr_t asconf;
2744 struct sctp_chunk *retval;
2745 int length = sizeof(asconf) + vparam_len;
2746 union sctp_addr_param addrparam;
2747 int addrlen;
2748 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
2749
2750 addrlen = af->to_addr_param(addr, &addrparam);
2751 if (!addrlen)
2752 return NULL;
2753 length += addrlen;
2754
2755 /* Create the chunk. */
2756 retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length);
2757 if (!retval)
2758 return NULL;
2759
2760 asconf.serial = htonl(asoc->addip_serial++);
2761
2762 retval->subh.addip_hdr =
2763 sctp_addto_chunk(retval, sizeof(asconf), &asconf);
2764 retval->param_hdr.v =
2765 sctp_addto_chunk(retval, addrlen, &addrparam);
2766
2767 return retval;
2768}
2769
2770/* ADDIP
2771 * 3.2.1 Add IP Address
2772 * 0 1 2 3
2773 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2774 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2775 * | Type = 0xC001 | Length = Variable |
2776 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2777 * | ASCONF-Request Correlation ID |
2778 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2779 * | Address Parameter |
2780 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2781 *
2782 * 3.2.2 Delete IP Address
2783 * 0 1 2 3
2784 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2785 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2786 * | Type = 0xC002 | Length = Variable |
2787 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2788 * | ASCONF-Request Correlation ID |
2789 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2790 * | Address Parameter |
2791 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2792 *
2793 */
2794struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc,
2795 union sctp_addr *laddr,
2796 struct sockaddr *addrs,
2797 int addrcnt,
2798 __be16 flags)
2799{
2800 sctp_addip_param_t param;
2801 struct sctp_chunk *retval;
2802 union sctp_addr_param addr_param;
2803 union sctp_addr *addr;
2804 void *addr_buf;
2805 struct sctp_af *af;
2806 int paramlen = sizeof(param);
2807 int addr_param_len = 0;
2808 int totallen = 0;
2809 int i;
2810 int del_pickup = 0;
2811
2812 /* Get total length of all the address parameters. */
2813 addr_buf = addrs;
2814 for (i = 0; i < addrcnt; i++) {
2815 addr = addr_buf;
2816 af = sctp_get_af_specific(addr->v4.sin_family);
2817 addr_param_len = af->to_addr_param(addr, &addr_param);
2818
2819 totallen += paramlen;
2820 totallen += addr_param_len;
2821
2822 addr_buf += af->sockaddr_len;
2823 if (asoc->asconf_addr_del_pending && !del_pickup) {
2824 /* reuse the parameter length from the same scope one */
2825 totallen += paramlen;
2826 totallen += addr_param_len;
2827 del_pickup = 1;
2828
2829 pr_debug("%s: picked same-scope del_pending addr, "
2830 "totallen for all addresses is %d\n",
2831 __func__, totallen);
2832 }
2833 }
2834
2835 /* Create an asconf chunk with the required length. */
2836 retval = sctp_make_asconf(asoc, laddr, totallen);
2837 if (!retval)
2838 return NULL;
2839
2840 /* Add the address parameters to the asconf chunk. */
2841 addr_buf = addrs;
2842 for (i = 0; i < addrcnt; i++) {
2843 addr = addr_buf;
2844 af = sctp_get_af_specific(addr->v4.sin_family);
2845 addr_param_len = af->to_addr_param(addr, &addr_param);
2846 param.param_hdr.type = flags;
2847 param.param_hdr.length = htons(paramlen + addr_param_len);
2848 param.crr_id = i;
2849
2850 sctp_addto_chunk(retval, paramlen, ¶m);
2851 sctp_addto_chunk(retval, addr_param_len, &addr_param);
2852
2853 addr_buf += af->sockaddr_len;
2854 }
2855 if (flags == SCTP_PARAM_ADD_IP && del_pickup) {
2856 addr = asoc->asconf_addr_del_pending;
2857 af = sctp_get_af_specific(addr->v4.sin_family);
2858 addr_param_len = af->to_addr_param(addr, &addr_param);
2859 param.param_hdr.type = SCTP_PARAM_DEL_IP;
2860 param.param_hdr.length = htons(paramlen + addr_param_len);
2861 param.crr_id = i;
2862
2863 sctp_addto_chunk(retval, paramlen, ¶m);
2864 sctp_addto_chunk(retval, addr_param_len, &addr_param);
2865 }
2866 return retval;
2867}
2868
2869/* ADDIP
2870 * 3.2.4 Set Primary IP Address
2871 * 0 1 2 3
2872 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2873 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2874 * | Type =0xC004 | Length = Variable |
2875 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2876 * | ASCONF-Request Correlation ID |
2877 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2878 * | Address Parameter |
2879 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2880 *
2881 * Create an ASCONF chunk with Set Primary IP address parameter.
2882 */
2883struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
2884 union sctp_addr *addr)
2885{
2886 sctp_addip_param_t param;
2887 struct sctp_chunk *retval;
2888 int len = sizeof(param);
2889 union sctp_addr_param addrparam;
2890 int addrlen;
2891 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
2892
2893 addrlen = af->to_addr_param(addr, &addrparam);
2894 if (!addrlen)
2895 return NULL;
2896 len += addrlen;
2897
2898 /* Create the chunk and make asconf header. */
2899 retval = sctp_make_asconf(asoc, addr, len);
2900 if (!retval)
2901 return NULL;
2902
2903 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY;
2904 param.param_hdr.length = htons(len);
2905 param.crr_id = 0;
2906
2907 sctp_addto_chunk(retval, sizeof(param), ¶m);
2908 sctp_addto_chunk(retval, addrlen, &addrparam);
2909
2910 return retval;
2911}
2912
2913/* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK)
2914 * 0 1 2 3
2915 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2916 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2917 * | Type = 0x80 | Chunk Flags | Chunk Length |
2918 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2919 * | Serial Number |
2920 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2921 * | ASCONF Parameter Response#1 |
2922 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2923 * \ \
2924 * / .... /
2925 * \ \
2926 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2927 * | ASCONF Parameter Response#N |
2928 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2929 *
2930 * Create an ASCONF_ACK chunk with enough space for the parameter responses.
2931 */
2932static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc,
2933 __u32 serial, int vparam_len)
2934{
2935 sctp_addiphdr_t asconf;
2936 struct sctp_chunk *retval;
2937 int length = sizeof(asconf) + vparam_len;
2938
2939 /* Create the chunk. */
2940 retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length);
2941 if (!retval)
2942 return NULL;
2943
2944 asconf.serial = htonl(serial);
2945
2946 retval->subh.addip_hdr =
2947 sctp_addto_chunk(retval, sizeof(asconf), &asconf);
2948
2949 return retval;
2950}
2951
2952/* Add response parameters to an ASCONF_ACK chunk. */
2953static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id,
2954 __be16 err_code, sctp_addip_param_t *asconf_param)
2955{
2956 sctp_addip_param_t ack_param;
2957 sctp_errhdr_t err_param;
2958 int asconf_param_len = 0;
2959 int err_param_len = 0;
2960 __be16 response_type;
2961
2962 if (SCTP_ERROR_NO_ERROR == err_code) {
2963 response_type = SCTP_PARAM_SUCCESS_REPORT;
2964 } else {
2965 response_type = SCTP_PARAM_ERR_CAUSE;
2966 err_param_len = sizeof(err_param);
2967 if (asconf_param)
2968 asconf_param_len =
2969 ntohs(asconf_param->param_hdr.length);
2970 }
2971
2972 /* Add Success Indication or Error Cause Indication parameter. */
2973 ack_param.param_hdr.type = response_type;
2974 ack_param.param_hdr.length = htons(sizeof(ack_param) +
2975 err_param_len +
2976 asconf_param_len);
2977 ack_param.crr_id = crr_id;
2978 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param);
2979
2980 if (SCTP_ERROR_NO_ERROR == err_code)
2981 return;
2982
2983 /* Add Error Cause parameter. */
2984 err_param.cause = err_code;
2985 err_param.length = htons(err_param_len + asconf_param_len);
2986 sctp_addto_chunk(chunk, err_param_len, &err_param);
2987
2988 /* Add the failed TLV copied from ASCONF chunk. */
2989 if (asconf_param)
2990 sctp_addto_chunk(chunk, asconf_param_len, asconf_param);
2991}
2992
2993/* Process a asconf parameter. */
2994static __be16 sctp_process_asconf_param(struct sctp_association *asoc,
2995 struct sctp_chunk *asconf,
2996 sctp_addip_param_t *asconf_param)
2997{
2998 struct sctp_transport *peer;
2999 struct sctp_af *af;
3000 union sctp_addr addr;
3001 union sctp_addr_param *addr_param;
3002
3003 addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t);
3004
3005 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP &&
3006 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP &&
3007 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY)
3008 return SCTP_ERROR_UNKNOWN_PARAM;
3009
3010 switch (addr_param->p.type) {
3011 case SCTP_PARAM_IPV6_ADDRESS:
3012 if (!asoc->peer.ipv6_address)
3013 return SCTP_ERROR_DNS_FAILED;
3014 break;
3015 case SCTP_PARAM_IPV4_ADDRESS:
3016 if (!asoc->peer.ipv4_address)
3017 return SCTP_ERROR_DNS_FAILED;
3018 break;
3019 default:
3020 return SCTP_ERROR_DNS_FAILED;
3021 }
3022
3023 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
3024 if (unlikely(!af))
3025 return SCTP_ERROR_DNS_FAILED;
3026
3027 af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0);
3028
3029 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast
3030 * or multicast address.
3031 * (note: wildcard is permitted and requires special handling so
3032 * make sure we check for that)
3033 */
3034 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb))
3035 return SCTP_ERROR_DNS_FAILED;
3036
3037 switch (asconf_param->param_hdr.type) {
3038 case SCTP_PARAM_ADD_IP:
3039 /* Section 4.2.1:
3040 * If the address 0.0.0.0 or ::0 is provided, the source
3041 * address of the packet MUST be added.
3042 */
3043 if (af->is_any(&addr))
3044 memcpy(&addr, &asconf->source, sizeof(addr));
3045
3046 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address
3047 * request and does not have the local resources to add this
3048 * new address to the association, it MUST return an Error
3049 * Cause TLV set to the new error code 'Operation Refused
3050 * Due to Resource Shortage'.
3051 */
3052
3053 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED);
3054 if (!peer)
3055 return SCTP_ERROR_RSRC_LOW;
3056
3057 /* Start the heartbeat timer. */
3058 if (!mod_timer(&peer->hb_timer, sctp_transport_timeout(peer)))
3059 sctp_transport_hold(peer);
3060 asoc->new_transport = peer;
3061 break;
3062 case SCTP_PARAM_DEL_IP:
3063 /* ADDIP 4.3 D7) If a request is received to delete the
3064 * last remaining IP address of a peer endpoint, the receiver
3065 * MUST send an Error Cause TLV with the error cause set to the
3066 * new error code 'Request to Delete Last Remaining IP Address'.
3067 */
3068 if (asoc->peer.transport_count == 1)
3069 return SCTP_ERROR_DEL_LAST_IP;
3070
3071 /* ADDIP 4.3 D8) If a request is received to delete an IP
3072 * address which is also the source address of the IP packet
3073 * which contained the ASCONF chunk, the receiver MUST reject
3074 * this request. To reject the request the receiver MUST send
3075 * an Error Cause TLV set to the new error code 'Request to
3076 * Delete Source IP Address'
3077 */
3078 if (sctp_cmp_addr_exact(&asconf->source, &addr))
3079 return SCTP_ERROR_DEL_SRC_IP;
3080
3081 /* Section 4.2.2
3082 * If the address 0.0.0.0 or ::0 is provided, all
3083 * addresses of the peer except the source address of the
3084 * packet MUST be deleted.
3085 */
3086 if (af->is_any(&addr)) {
3087 sctp_assoc_set_primary(asoc, asconf->transport);
3088 sctp_assoc_del_nonprimary_peers(asoc,
3089 asconf->transport);
3090 } else
3091 sctp_assoc_del_peer(asoc, &addr);
3092 break;
3093 case SCTP_PARAM_SET_PRIMARY:
3094 /* ADDIP Section 4.2.4
3095 * If the address 0.0.0.0 or ::0 is provided, the receiver
3096 * MAY mark the source address of the packet as its
3097 * primary.
3098 */
3099 if (af->is_any(&addr))
3100 memcpy(&addr.v4, sctp_source(asconf), sizeof(addr));
3101
3102 peer = sctp_assoc_lookup_paddr(asoc, &addr);
3103 if (!peer)
3104 return SCTP_ERROR_DNS_FAILED;
3105
3106 sctp_assoc_set_primary(asoc, peer);
3107 break;
3108 }
3109
3110 return SCTP_ERROR_NO_ERROR;
3111}
3112
3113/* Verify the ASCONF packet before we process it. */
3114int sctp_verify_asconf(const struct sctp_association *asoc,
3115 struct sctp_paramhdr *param_hdr, void *chunk_end,
3116 struct sctp_paramhdr **errp) {
3117 sctp_addip_param_t *asconf_param;
3118 union sctp_params param;
3119 int length, plen;
3120
3121 param.v = (sctp_paramhdr_t *) param_hdr;
3122 while (param.v <= chunk_end - sizeof(sctp_paramhdr_t)) {
3123 length = ntohs(param.p->length);
3124 *errp = param.p;
3125
3126 if (param.v > chunk_end - length ||
3127 length < sizeof(sctp_paramhdr_t))
3128 return 0;
3129
3130 switch (param.p->type) {
3131 case SCTP_PARAM_ADD_IP:
3132 case SCTP_PARAM_DEL_IP:
3133 case SCTP_PARAM_SET_PRIMARY:
3134 asconf_param = (sctp_addip_param_t *)param.v;
3135 plen = ntohs(asconf_param->param_hdr.length);
3136 if (plen < sizeof(sctp_addip_param_t) +
3137 sizeof(sctp_paramhdr_t))
3138 return 0;
3139 break;
3140 case SCTP_PARAM_SUCCESS_REPORT:
3141 case SCTP_PARAM_ADAPTATION_LAYER_IND:
3142 if (length != sizeof(sctp_addip_param_t))
3143 return 0;
3144
3145 break;
3146 default:
3147 break;
3148 }
3149
3150 param.v += WORD_ROUND(length);
3151 }
3152
3153 if (param.v != chunk_end)
3154 return 0;
3155
3156 return 1;
3157}
3158
3159/* Process an incoming ASCONF chunk with the next expected serial no. and
3160 * return an ASCONF_ACK chunk to be sent in response.
3161 */
3162struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
3163 struct sctp_chunk *asconf)
3164{
3165 sctp_addiphdr_t *hdr;
3166 union sctp_addr_param *addr_param;
3167 sctp_addip_param_t *asconf_param;
3168 struct sctp_chunk *asconf_ack;
3169
3170 __be16 err_code;
3171 int length = 0;
3172 int chunk_len;
3173 __u32 serial;
3174 int all_param_pass = 1;
3175
3176 chunk_len = ntohs(asconf->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
3177 hdr = (sctp_addiphdr_t *)asconf->skb->data;
3178 serial = ntohl(hdr->serial);
3179
3180 /* Skip the addiphdr and store a pointer to address parameter. */
3181 length = sizeof(sctp_addiphdr_t);
3182 addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
3183 chunk_len -= length;
3184
3185 /* Skip the address parameter and store a pointer to the first
3186 * asconf parameter.
3187 */
3188 length = ntohs(addr_param->p.length);
3189 asconf_param = (void *)addr_param + length;
3190 chunk_len -= length;
3191
3192 /* create an ASCONF_ACK chunk.
3193 * Based on the definitions of parameters, we know that the size of
3194 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF
3195 * parameters.
3196 */
3197 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4);
3198 if (!asconf_ack)
3199 goto done;
3200
3201 /* Process the TLVs contained within the ASCONF chunk. */
3202 while (chunk_len > 0) {
3203 err_code = sctp_process_asconf_param(asoc, asconf,
3204 asconf_param);
3205 /* ADDIP 4.1 A7)
3206 * If an error response is received for a TLV parameter,
3207 * all TLVs with no response before the failed TLV are
3208 * considered successful if not reported. All TLVs after
3209 * the failed response are considered unsuccessful unless
3210 * a specific success indication is present for the parameter.
3211 */
3212 if (SCTP_ERROR_NO_ERROR != err_code)
3213 all_param_pass = 0;
3214
3215 if (!all_param_pass)
3216 sctp_add_asconf_response(asconf_ack,
3217 asconf_param->crr_id, err_code,
3218 asconf_param);
3219
3220 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add
3221 * an IP address sends an 'Out of Resource' in its response, it
3222 * MUST also fail any subsequent add or delete requests bundled
3223 * in the ASCONF.
3224 */
3225 if (SCTP_ERROR_RSRC_LOW == err_code)
3226 goto done;
3227
3228 /* Move to the next ASCONF param. */
3229 length = ntohs(asconf_param->param_hdr.length);
3230 asconf_param = (void *)asconf_param + length;
3231 chunk_len -= length;
3232 }
3233
3234done:
3235 asoc->peer.addip_serial++;
3236
3237 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc
3238 * after freeing the reference to old asconf ack if any.
3239 */
3240 if (asconf_ack) {
3241 sctp_chunk_hold(asconf_ack);
3242 list_add_tail(&asconf_ack->transmitted_list,
3243 &asoc->asconf_ack_list);
3244 }
3245
3246 return asconf_ack;
3247}
3248
3249/* Process a asconf parameter that is successfully acked. */
3250static void sctp_asconf_param_success(struct sctp_association *asoc,
3251 sctp_addip_param_t *asconf_param)
3252{
3253 struct sctp_af *af;
3254 union sctp_addr addr;
3255 struct sctp_bind_addr *bp = &asoc->base.bind_addr;
3256 union sctp_addr_param *addr_param;
3257 struct sctp_transport *transport;
3258 struct sctp_sockaddr_entry *saddr;
3259
3260 addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t);
3261
3262 /* We have checked the packet before, so we do not check again. */
3263 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
3264 af->from_addr_param(&addr, addr_param, htons(bp->port), 0);
3265
3266 switch (asconf_param->param_hdr.type) {
3267 case SCTP_PARAM_ADD_IP:
3268 /* This is always done in BH context with a socket lock
3269 * held, so the list can not change.
3270 */
3271 local_bh_disable();
3272 list_for_each_entry(saddr, &bp->address_list, list) {
3273 if (sctp_cmp_addr_exact(&saddr->a, &addr))
3274 saddr->state = SCTP_ADDR_SRC;
3275 }
3276 local_bh_enable();
3277 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
3278 transports) {
3279 dst_release(transport->dst);
3280 transport->dst = NULL;
3281 }
3282 break;
3283 case SCTP_PARAM_DEL_IP:
3284 local_bh_disable();
3285 sctp_del_bind_addr(bp, &addr);
3286 if (asoc->asconf_addr_del_pending != NULL &&
3287 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) {
3288 kfree(asoc->asconf_addr_del_pending);
3289 asoc->asconf_addr_del_pending = NULL;
3290 }
3291 local_bh_enable();
3292 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
3293 transports) {
3294 dst_release(transport->dst);
3295 transport->dst = NULL;
3296 }
3297 break;
3298 default:
3299 break;
3300 }
3301}
3302
3303/* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk
3304 * for the given asconf parameter. If there is no response for this parameter,
3305 * return the error code based on the third argument 'no_err'.
3306 * ADDIP 4.1
3307 * A7) If an error response is received for a TLV parameter, all TLVs with no
3308 * response before the failed TLV are considered successful if not reported.
3309 * All TLVs after the failed response are considered unsuccessful unless a
3310 * specific success indication is present for the parameter.
3311 */
3312static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack,
3313 sctp_addip_param_t *asconf_param,
3314 int no_err)
3315{
3316 sctp_addip_param_t *asconf_ack_param;
3317 sctp_errhdr_t *err_param;
3318 int length;
3319 int asconf_ack_len;
3320 __be16 err_code;
3321
3322 if (no_err)
3323 err_code = SCTP_ERROR_NO_ERROR;
3324 else
3325 err_code = SCTP_ERROR_REQ_REFUSED;
3326
3327 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) -
3328 sizeof(sctp_chunkhdr_t);
3329
3330 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to
3331 * the first asconf_ack parameter.
3332 */
3333 length = sizeof(sctp_addiphdr_t);
3334 asconf_ack_param = (sctp_addip_param_t *)(asconf_ack->skb->data +
3335 length);
3336 asconf_ack_len -= length;
3337
3338 while (asconf_ack_len > 0) {
3339 if (asconf_ack_param->crr_id == asconf_param->crr_id) {
3340 switch (asconf_ack_param->param_hdr.type) {
3341 case SCTP_PARAM_SUCCESS_REPORT:
3342 return SCTP_ERROR_NO_ERROR;
3343 case SCTP_PARAM_ERR_CAUSE:
3344 length = sizeof(sctp_addip_param_t);
3345 err_param = (void *)asconf_ack_param + length;
3346 asconf_ack_len -= length;
3347 if (asconf_ack_len > 0)
3348 return err_param->cause;
3349 else
3350 return SCTP_ERROR_INV_PARAM;
3351 break;
3352 default:
3353 return SCTP_ERROR_INV_PARAM;
3354 }
3355 }
3356
3357 length = ntohs(asconf_ack_param->param_hdr.length);
3358 asconf_ack_param = (void *)asconf_ack_param + length;
3359 asconf_ack_len -= length;
3360 }
3361
3362 return err_code;
3363}
3364
3365/* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */
3366int sctp_process_asconf_ack(struct sctp_association *asoc,
3367 struct sctp_chunk *asconf_ack)
3368{
3369 struct sctp_chunk *asconf = asoc->addip_last_asconf;
3370 union sctp_addr_param *addr_param;
3371 sctp_addip_param_t *asconf_param;
3372 int length = 0;
3373 int asconf_len = asconf->skb->len;
3374 int all_param_pass = 0;
3375 int no_err = 1;
3376 int retval = 0;
3377 __be16 err_code = SCTP_ERROR_NO_ERROR;
3378
3379 /* Skip the chunkhdr and addiphdr from the last asconf sent and store
3380 * a pointer to address parameter.
3381 */
3382 length = sizeof(sctp_addip_chunk_t);
3383 addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
3384 asconf_len -= length;
3385
3386 /* Skip the address parameter in the last asconf sent and store a
3387 * pointer to the first asconf parameter.
3388 */
3389 length = ntohs(addr_param->p.length);
3390 asconf_param = (void *)addr_param + length;
3391 asconf_len -= length;
3392
3393 /* ADDIP 4.1
3394 * A8) If there is no response(s) to specific TLV parameter(s), and no
3395 * failures are indicated, then all request(s) are considered
3396 * successful.
3397 */
3398 if (asconf_ack->skb->len == sizeof(sctp_addiphdr_t))
3399 all_param_pass = 1;
3400
3401 /* Process the TLVs contained in the last sent ASCONF chunk. */
3402 while (asconf_len > 0) {
3403 if (all_param_pass)
3404 err_code = SCTP_ERROR_NO_ERROR;
3405 else {
3406 err_code = sctp_get_asconf_response(asconf_ack,
3407 asconf_param,
3408 no_err);
3409 if (no_err && (SCTP_ERROR_NO_ERROR != err_code))
3410 no_err = 0;
3411 }
3412
3413 switch (err_code) {
3414 case SCTP_ERROR_NO_ERROR:
3415 sctp_asconf_param_success(asoc, asconf_param);
3416 break;
3417
3418 case SCTP_ERROR_RSRC_LOW:
3419 retval = 1;
3420 break;
3421
3422 case SCTP_ERROR_UNKNOWN_PARAM:
3423 /* Disable sending this type of asconf parameter in
3424 * future.
3425 */
3426 asoc->peer.addip_disabled_mask |=
3427 asconf_param->param_hdr.type;
3428 break;
3429
3430 case SCTP_ERROR_REQ_REFUSED:
3431 case SCTP_ERROR_DEL_LAST_IP:
3432 case SCTP_ERROR_DEL_SRC_IP:
3433 default:
3434 break;
3435 }
3436
3437 /* Skip the processed asconf parameter and move to the next
3438 * one.
3439 */
3440 length = ntohs(asconf_param->param_hdr.length);
3441 asconf_param = (void *)asconf_param + length;
3442 asconf_len -= length;
3443 }
3444
3445 if (no_err && asoc->src_out_of_asoc_ok) {
3446 asoc->src_out_of_asoc_ok = 0;
3447 sctp_transport_immediate_rtx(asoc->peer.primary_path);
3448 }
3449
3450 /* Free the cached last sent asconf chunk. */
3451 list_del_init(&asconf->transmitted_list);
3452 sctp_chunk_free(asconf);
3453 asoc->addip_last_asconf = NULL;
3454
3455 return retval;
3456}
3457
3458/* Make a FWD TSN chunk. */
3459struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
3460 __u32 new_cum_tsn, size_t nstreams,
3461 struct sctp_fwdtsn_skip *skiplist)
3462{
3463 struct sctp_chunk *retval = NULL;
3464 struct sctp_fwdtsn_hdr ftsn_hdr;
3465 struct sctp_fwdtsn_skip skip;
3466 size_t hint;
3467 int i;
3468
3469 hint = (nstreams + 1) * sizeof(__u32);
3470
3471 retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint);
3472
3473 if (!retval)
3474 return NULL;
3475
3476 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn);
3477 retval->subh.fwdtsn_hdr =
3478 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr);
3479
3480 for (i = 0; i < nstreams; i++) {
3481 skip.stream = skiplist[i].stream;
3482 skip.ssn = skiplist[i].ssn;
3483 sctp_addto_chunk(retval, sizeof(skip), &skip);
3484 }
3485
3486 return retval;
3487}
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 *
8 * This file is part of the SCTP kernel implementation
9 *
10 * These functions work with the state functions in sctp_sm_statefuns.c
11 * to implement the state operations. These functions implement the
12 * steps which require modifying existing data structures.
13 *
14 * Please send any bug reports or fixes you make to the
15 * email address(es):
16 * lksctp developers <linux-sctp@vger.kernel.org>
17 *
18 * Written or modified by:
19 * La Monte H.P. Yarroll <piggy@acm.org>
20 * Karl Knutson <karl@athena.chicago.il.us>
21 * C. Robin <chris@hundredacre.ac.uk>
22 * Jon Grimm <jgrimm@us.ibm.com>
23 * Xingang Guo <xingang.guo@intel.com>
24 * Dajiang Zhang <dajiang.zhang@nokia.com>
25 * Sridhar Samudrala <sri@us.ibm.com>
26 * Daisy Chang <daisyc@us.ibm.com>
27 * Ardelle Fan <ardelle.fan@intel.com>
28 * Kevin Gao <kevin.gao@intel.com>
29 */
30
31#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
32
33#include <crypto/hash.h>
34#include <linux/types.h>
35#include <linux/kernel.h>
36#include <linux/ip.h>
37#include <linux/ipv6.h>
38#include <linux/net.h>
39#include <linux/inet.h>
40#include <linux/scatterlist.h>
41#include <linux/slab.h>
42#include <net/sock.h>
43
44#include <linux/skbuff.h>
45#include <linux/random.h> /* for get_random_bytes */
46#include <net/sctp/sctp.h>
47#include <net/sctp/sm.h>
48
49static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc,
50 __u8 type, __u8 flags, int paylen,
51 gfp_t gfp);
52static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc,
53 __u8 flags, int paylen, gfp_t gfp);
54static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc,
55 __u8 type, __u8 flags, int paylen,
56 gfp_t gfp);
57static struct sctp_cookie_param *sctp_pack_cookie(
58 const struct sctp_endpoint *ep,
59 const struct sctp_association *asoc,
60 const struct sctp_chunk *init_chunk,
61 int *cookie_len,
62 const __u8 *raw_addrs, int addrs_len);
63static int sctp_process_param(struct sctp_association *asoc,
64 union sctp_params param,
65 const union sctp_addr *peer_addr,
66 gfp_t gfp);
67static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
68 const void *data);
69
70/* Control chunk destructor */
71static void sctp_control_release_owner(struct sk_buff *skb)
72{
73 struct sctp_chunk *chunk = skb_shinfo(skb)->destructor_arg;
74
75 if (chunk->shkey) {
76 struct sctp_shared_key *shkey = chunk->shkey;
77 struct sctp_association *asoc = chunk->asoc;
78
79 /* refcnt == 2 and !list_empty mean after this release, it's
80 * not being used anywhere, and it's time to notify userland
81 * that this shkey can be freed if it's been deactivated.
82 */
83 if (shkey->deactivated && !list_empty(&shkey->key_list) &&
84 refcount_read(&shkey->refcnt) == 2) {
85 struct sctp_ulpevent *ev;
86
87 ev = sctp_ulpevent_make_authkey(asoc, shkey->key_id,
88 SCTP_AUTH_FREE_KEY,
89 GFP_KERNEL);
90 if (ev)
91 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
92 }
93 sctp_auth_shkey_release(chunk->shkey);
94 }
95}
96
97static void sctp_control_set_owner_w(struct sctp_chunk *chunk)
98{
99 struct sctp_association *asoc = chunk->asoc;
100 struct sk_buff *skb = chunk->skb;
101
102 /* TODO: properly account for control chunks.
103 * To do it right we'll need:
104 * 1) endpoint if association isn't known.
105 * 2) proper memory accounting.
106 *
107 * For now don't do anything for now.
108 */
109 if (chunk->auth) {
110 chunk->shkey = asoc->shkey;
111 sctp_auth_shkey_hold(chunk->shkey);
112 }
113 skb->sk = asoc ? asoc->base.sk : NULL;
114 skb_shinfo(skb)->destructor_arg = chunk;
115 skb->destructor = sctp_control_release_owner;
116}
117
118/* What was the inbound interface for this chunk? */
119int sctp_chunk_iif(const struct sctp_chunk *chunk)
120{
121 struct sk_buff *skb = chunk->skb;
122
123 return SCTP_INPUT_CB(skb)->af->skb_iif(skb);
124}
125
126/* RFC 2960 3.3.2 Initiation (INIT) (1)
127 *
128 * Note 2: The ECN capable field is reserved for future use of
129 * Explicit Congestion Notification.
130 */
131static const struct sctp_paramhdr ecap_param = {
132 SCTP_PARAM_ECN_CAPABLE,
133 cpu_to_be16(sizeof(struct sctp_paramhdr)),
134};
135static const struct sctp_paramhdr prsctp_param = {
136 SCTP_PARAM_FWD_TSN_SUPPORT,
137 cpu_to_be16(sizeof(struct sctp_paramhdr)),
138};
139
140/* A helper to initialize an op error inside a provided chunk, as most
141 * cause codes will be embedded inside an abort chunk.
142 */
143int sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code,
144 size_t paylen)
145{
146 struct sctp_errhdr err;
147 __u16 len;
148
149 /* Cause code constants are now defined in network order. */
150 err.cause = cause_code;
151 len = sizeof(err) + paylen;
152 err.length = htons(len);
153
154 if (skb_tailroom(chunk->skb) < len)
155 return -ENOSPC;
156
157 chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(err), &err);
158
159 return 0;
160}
161
162/* 3.3.2 Initiation (INIT) (1)
163 *
164 * This chunk is used to initiate a SCTP association between two
165 * endpoints. The format of the INIT chunk is shown below:
166 *
167 * 0 1 2 3
168 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
169 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
170 * | Type = 1 | Chunk Flags | Chunk Length |
171 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
172 * | Initiate Tag |
173 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
174 * | Advertised Receiver Window Credit (a_rwnd) |
175 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
176 * | Number of Outbound Streams | Number of Inbound Streams |
177 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
178 * | Initial TSN |
179 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
180 * \ \
181 * / Optional/Variable-Length Parameters /
182 * \ \
183 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
184 *
185 *
186 * The INIT chunk contains the following parameters. Unless otherwise
187 * noted, each parameter MUST only be included once in the INIT chunk.
188 *
189 * Fixed Parameters Status
190 * ----------------------------------------------
191 * Initiate Tag Mandatory
192 * Advertised Receiver Window Credit Mandatory
193 * Number of Outbound Streams Mandatory
194 * Number of Inbound Streams Mandatory
195 * Initial TSN Mandatory
196 *
197 * Variable Parameters Status Type Value
198 * -------------------------------------------------------------
199 * IPv4 Address (Note 1) Optional 5
200 * IPv6 Address (Note 1) Optional 6
201 * Cookie Preservative Optional 9
202 * Reserved for ECN Capable (Note 2) Optional 32768 (0x8000)
203 * Host Name Address (Note 3) Optional 11
204 * Supported Address Types (Note 4) Optional 12
205 */
206struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc,
207 const struct sctp_bind_addr *bp,
208 gfp_t gfp, int vparam_len)
209{
210 struct sctp_supported_ext_param ext_param;
211 struct sctp_adaptation_ind_param aiparam;
212 struct sctp_paramhdr *auth_chunks = NULL;
213 struct sctp_paramhdr *auth_hmacs = NULL;
214 struct sctp_supported_addrs_param sat;
215 struct sctp_endpoint *ep = asoc->ep;
216 struct sctp_chunk *retval = NULL;
217 int num_types, addrs_len = 0;
218 struct sctp_inithdr init;
219 union sctp_params addrs;
220 struct sctp_sock *sp;
221 __u8 extensions[5];
222 size_t chunksize;
223 __be16 types[2];
224 int num_ext = 0;
225
226 /* RFC 2960 3.3.2 Initiation (INIT) (1)
227 *
228 * Note 1: The INIT chunks can contain multiple addresses that
229 * can be IPv4 and/or IPv6 in any combination.
230 */
231
232 /* Convert the provided bind address list to raw format. */
233 addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp);
234
235 init.init_tag = htonl(asoc->c.my_vtag);
236 init.a_rwnd = htonl(asoc->rwnd);
237 init.num_outbound_streams = htons(asoc->c.sinit_num_ostreams);
238 init.num_inbound_streams = htons(asoc->c.sinit_max_instreams);
239 init.initial_tsn = htonl(asoc->c.initial_tsn);
240
241 /* How many address types are needed? */
242 sp = sctp_sk(asoc->base.sk);
243 num_types = sp->pf->supported_addrs(sp, types);
244
245 chunksize = sizeof(init) + addrs_len;
246 chunksize += SCTP_PAD4(SCTP_SAT_LEN(num_types));
247
248 if (asoc->ep->ecn_enable)
249 chunksize += sizeof(ecap_param);
250
251 if (asoc->ep->prsctp_enable)
252 chunksize += sizeof(prsctp_param);
253
254 /* ADDIP: Section 4.2.7:
255 * An implementation supporting this extension [ADDIP] MUST list
256 * the ASCONF,the ASCONF-ACK, and the AUTH chunks in its INIT and
257 * INIT-ACK parameters.
258 */
259 if (asoc->ep->asconf_enable) {
260 extensions[num_ext] = SCTP_CID_ASCONF;
261 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
262 num_ext += 2;
263 }
264
265 if (asoc->ep->reconf_enable) {
266 extensions[num_ext] = SCTP_CID_RECONF;
267 num_ext += 1;
268 }
269
270 if (sp->adaptation_ind)
271 chunksize += sizeof(aiparam);
272
273 if (asoc->ep->intl_enable) {
274 extensions[num_ext] = SCTP_CID_I_DATA;
275 num_ext += 1;
276 }
277
278 chunksize += vparam_len;
279
280 /* Account for AUTH related parameters */
281 if (ep->auth_enable) {
282 /* Add random parameter length*/
283 chunksize += sizeof(asoc->c.auth_random);
284
285 /* Add HMACS parameter length if any were defined */
286 auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs;
287 if (auth_hmacs->length)
288 chunksize += SCTP_PAD4(ntohs(auth_hmacs->length));
289 else
290 auth_hmacs = NULL;
291
292 /* Add CHUNKS parameter length */
293 auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks;
294 if (auth_chunks->length)
295 chunksize += SCTP_PAD4(ntohs(auth_chunks->length));
296 else
297 auth_chunks = NULL;
298
299 extensions[num_ext] = SCTP_CID_AUTH;
300 num_ext += 1;
301 }
302
303 /* If we have any extensions to report, account for that */
304 if (num_ext)
305 chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext);
306
307 /* RFC 2960 3.3.2 Initiation (INIT) (1)
308 *
309 * Note 3: An INIT chunk MUST NOT contain more than one Host
310 * Name address parameter. Moreover, the sender of the INIT
311 * MUST NOT combine any other address types with the Host Name
312 * address in the INIT. The receiver of INIT MUST ignore any
313 * other address types if the Host Name address parameter is
314 * present in the received INIT chunk.
315 *
316 * PLEASE DO NOT FIXME [This version does not support Host Name.]
317 */
318
319 retval = sctp_make_control(asoc, SCTP_CID_INIT, 0, chunksize, gfp);
320 if (!retval)
321 goto nodata;
322
323 retval->subh.init_hdr =
324 sctp_addto_chunk(retval, sizeof(init), &init);
325 retval->param_hdr.v =
326 sctp_addto_chunk(retval, addrs_len, addrs.v);
327
328 /* RFC 2960 3.3.2 Initiation (INIT) (1)
329 *
330 * Note 4: This parameter, when present, specifies all the
331 * address types the sending endpoint can support. The absence
332 * of this parameter indicates that the sending endpoint can
333 * support any address type.
334 */
335 sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES;
336 sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types));
337 sctp_addto_chunk(retval, sizeof(sat), &sat);
338 sctp_addto_chunk(retval, num_types * sizeof(__u16), &types);
339
340 if (asoc->ep->ecn_enable)
341 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
342
343 /* Add the supported extensions parameter. Be nice and add this
344 * fist before addiding the parameters for the extensions themselves
345 */
346 if (num_ext) {
347 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
348 ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext);
349 sctp_addto_chunk(retval, sizeof(ext_param), &ext_param);
350 sctp_addto_param(retval, num_ext, extensions);
351 }
352
353 if (asoc->ep->prsctp_enable)
354 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
355
356 if (sp->adaptation_ind) {
357 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
358 aiparam.param_hdr.length = htons(sizeof(aiparam));
359 aiparam.adaptation_ind = htonl(sp->adaptation_ind);
360 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
361 }
362
363 /* Add SCTP-AUTH chunks to the parameter list */
364 if (ep->auth_enable) {
365 sctp_addto_chunk(retval, sizeof(asoc->c.auth_random),
366 asoc->c.auth_random);
367 if (auth_hmacs)
368 sctp_addto_chunk(retval, ntohs(auth_hmacs->length),
369 auth_hmacs);
370 if (auth_chunks)
371 sctp_addto_chunk(retval, ntohs(auth_chunks->length),
372 auth_chunks);
373 }
374nodata:
375 kfree(addrs.v);
376 return retval;
377}
378
379struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc,
380 const struct sctp_chunk *chunk,
381 gfp_t gfp, int unkparam_len)
382{
383 struct sctp_supported_ext_param ext_param;
384 struct sctp_adaptation_ind_param aiparam;
385 struct sctp_paramhdr *auth_chunks = NULL;
386 struct sctp_paramhdr *auth_random = NULL;
387 struct sctp_paramhdr *auth_hmacs = NULL;
388 struct sctp_chunk *retval = NULL;
389 struct sctp_cookie_param *cookie;
390 struct sctp_inithdr initack;
391 union sctp_params addrs;
392 struct sctp_sock *sp;
393 __u8 extensions[5];
394 size_t chunksize;
395 int num_ext = 0;
396 int cookie_len;
397 int addrs_len;
398
399 /* Note: there may be no addresses to embed. */
400 addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp);
401
402 initack.init_tag = htonl(asoc->c.my_vtag);
403 initack.a_rwnd = htonl(asoc->rwnd);
404 initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams);
405 initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams);
406 initack.initial_tsn = htonl(asoc->c.initial_tsn);
407
408 /* FIXME: We really ought to build the cookie right
409 * into the packet instead of allocating more fresh memory.
410 */
411 cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len,
412 addrs.v, addrs_len);
413 if (!cookie)
414 goto nomem_cookie;
415
416 /* Calculate the total size of allocation, include the reserved
417 * space for reporting unknown parameters if it is specified.
418 */
419 sp = sctp_sk(asoc->base.sk);
420 chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len;
421
422 /* Tell peer that we'll do ECN only if peer advertised such cap. */
423 if (asoc->peer.ecn_capable)
424 chunksize += sizeof(ecap_param);
425
426 if (asoc->peer.prsctp_capable)
427 chunksize += sizeof(prsctp_param);
428
429 if (asoc->peer.asconf_capable) {
430 extensions[num_ext] = SCTP_CID_ASCONF;
431 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
432 num_ext += 2;
433 }
434
435 if (asoc->peer.reconf_capable) {
436 extensions[num_ext] = SCTP_CID_RECONF;
437 num_ext += 1;
438 }
439
440 if (sp->adaptation_ind)
441 chunksize += sizeof(aiparam);
442
443 if (asoc->peer.intl_capable) {
444 extensions[num_ext] = SCTP_CID_I_DATA;
445 num_ext += 1;
446 }
447
448 if (asoc->peer.auth_capable) {
449 auth_random = (struct sctp_paramhdr *)asoc->c.auth_random;
450 chunksize += ntohs(auth_random->length);
451
452 auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs;
453 if (auth_hmacs->length)
454 chunksize += SCTP_PAD4(ntohs(auth_hmacs->length));
455 else
456 auth_hmacs = NULL;
457
458 auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks;
459 if (auth_chunks->length)
460 chunksize += SCTP_PAD4(ntohs(auth_chunks->length));
461 else
462 auth_chunks = NULL;
463
464 extensions[num_ext] = SCTP_CID_AUTH;
465 num_ext += 1;
466 }
467
468 if (num_ext)
469 chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext);
470
471 /* Now allocate and fill out the chunk. */
472 retval = sctp_make_control(asoc, SCTP_CID_INIT_ACK, 0, chunksize, gfp);
473 if (!retval)
474 goto nomem_chunk;
475
476 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
477 *
478 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
479 * HEARTBEAT ACK, * etc.) to the same destination transport
480 * address from which it received the DATA or control chunk
481 * to which it is replying.
482 *
483 * [INIT ACK back to where the INIT came from.]
484 */
485 if (chunk->transport)
486 retval->transport =
487 sctp_assoc_lookup_paddr(asoc,
488 &chunk->transport->ipaddr);
489
490 retval->subh.init_hdr =
491 sctp_addto_chunk(retval, sizeof(initack), &initack);
492 retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v);
493 sctp_addto_chunk(retval, cookie_len, cookie);
494 if (asoc->peer.ecn_capable)
495 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
496 if (num_ext) {
497 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
498 ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext);
499 sctp_addto_chunk(retval, sizeof(ext_param), &ext_param);
500 sctp_addto_param(retval, num_ext, extensions);
501 }
502 if (asoc->peer.prsctp_capable)
503 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
504
505 if (sp->adaptation_ind) {
506 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
507 aiparam.param_hdr.length = htons(sizeof(aiparam));
508 aiparam.adaptation_ind = htonl(sp->adaptation_ind);
509 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
510 }
511
512 if (asoc->peer.auth_capable) {
513 sctp_addto_chunk(retval, ntohs(auth_random->length),
514 auth_random);
515 if (auth_hmacs)
516 sctp_addto_chunk(retval, ntohs(auth_hmacs->length),
517 auth_hmacs);
518 if (auth_chunks)
519 sctp_addto_chunk(retval, ntohs(auth_chunks->length),
520 auth_chunks);
521 }
522
523 /* We need to remove the const qualifier at this point. */
524 retval->asoc = (struct sctp_association *) asoc;
525
526nomem_chunk:
527 kfree(cookie);
528nomem_cookie:
529 kfree(addrs.v);
530 return retval;
531}
532
533/* 3.3.11 Cookie Echo (COOKIE ECHO) (10):
534 *
535 * This chunk is used only during the initialization of an association.
536 * It is sent by the initiator of an association to its peer to complete
537 * the initialization process. This chunk MUST precede any DATA chunk
538 * sent within the association, but MAY be bundled with one or more DATA
539 * chunks in the same packet.
540 *
541 * 0 1 2 3
542 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
543 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
544 * | Type = 10 |Chunk Flags | Length |
545 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
546 * / Cookie /
547 * \ \
548 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
549 *
550 * Chunk Flags: 8 bit
551 *
552 * Set to zero on transmit and ignored on receipt.
553 *
554 * Length: 16 bits (unsigned integer)
555 *
556 * Set to the size of the chunk in bytes, including the 4 bytes of
557 * the chunk header and the size of the Cookie.
558 *
559 * Cookie: variable size
560 *
561 * This field must contain the exact cookie received in the
562 * State Cookie parameter from the previous INIT ACK.
563 *
564 * An implementation SHOULD make the cookie as small as possible
565 * to insure interoperability.
566 */
567struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc,
568 const struct sctp_chunk *chunk)
569{
570 struct sctp_chunk *retval;
571 int cookie_len;
572 void *cookie;
573
574 cookie = asoc->peer.cookie;
575 cookie_len = asoc->peer.cookie_len;
576
577 /* Build a cookie echo chunk. */
578 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ECHO, 0,
579 cookie_len, GFP_ATOMIC);
580 if (!retval)
581 goto nodata;
582 retval->subh.cookie_hdr =
583 sctp_addto_chunk(retval, cookie_len, cookie);
584
585 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
586 *
587 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
588 * HEARTBEAT ACK, * etc.) to the same destination transport
589 * address from which it * received the DATA or control chunk
590 * to which it is replying.
591 *
592 * [COOKIE ECHO back to where the INIT ACK came from.]
593 */
594 if (chunk)
595 retval->transport = chunk->transport;
596
597nodata:
598 return retval;
599}
600
601/* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11):
602 *
603 * This chunk is used only during the initialization of an
604 * association. It is used to acknowledge the receipt of a COOKIE
605 * ECHO chunk. This chunk MUST precede any DATA or SACK chunk sent
606 * within the association, but MAY be bundled with one or more DATA
607 * chunks or SACK chunk in the same SCTP packet.
608 *
609 * 0 1 2 3
610 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
611 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
612 * | Type = 11 |Chunk Flags | Length = 4 |
613 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
614 *
615 * Chunk Flags: 8 bits
616 *
617 * Set to zero on transmit and ignored on receipt.
618 */
619struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc,
620 const struct sctp_chunk *chunk)
621{
622 struct sctp_chunk *retval;
623
624 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ACK, 0, 0, GFP_ATOMIC);
625
626 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
627 *
628 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
629 * HEARTBEAT ACK, * etc.) to the same destination transport
630 * address from which it * received the DATA or control chunk
631 * to which it is replying.
632 *
633 * [COOKIE ACK back to where the COOKIE ECHO came from.]
634 */
635 if (retval && chunk && chunk->transport)
636 retval->transport =
637 sctp_assoc_lookup_paddr(asoc,
638 &chunk->transport->ipaddr);
639
640 return retval;
641}
642
643/*
644 * Appendix A: Explicit Congestion Notification:
645 * CWR:
646 *
647 * RFC 2481 details a specific bit for a sender to send in the header of
648 * its next outbound TCP segment to indicate to its peer that it has
649 * reduced its congestion window. This is termed the CWR bit. For
650 * SCTP the same indication is made by including the CWR chunk.
651 * This chunk contains one data element, i.e. the TSN number that
652 * was sent in the ECNE chunk. This element represents the lowest
653 * TSN number in the datagram that was originally marked with the
654 * CE bit.
655 *
656 * 0 1 2 3
657 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
658 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
659 * | Chunk Type=13 | Flags=00000000| Chunk Length = 8 |
660 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
661 * | Lowest TSN Number |
662 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
663 *
664 * Note: The CWR is considered a Control chunk.
665 */
666struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc,
667 const __u32 lowest_tsn,
668 const struct sctp_chunk *chunk)
669{
670 struct sctp_chunk *retval;
671 struct sctp_cwrhdr cwr;
672
673 cwr.lowest_tsn = htonl(lowest_tsn);
674 retval = sctp_make_control(asoc, SCTP_CID_ECN_CWR, 0,
675 sizeof(cwr), GFP_ATOMIC);
676
677 if (!retval)
678 goto nodata;
679
680 retval->subh.ecn_cwr_hdr =
681 sctp_addto_chunk(retval, sizeof(cwr), &cwr);
682
683 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
684 *
685 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
686 * HEARTBEAT ACK, * etc.) to the same destination transport
687 * address from which it * received the DATA or control chunk
688 * to which it is replying.
689 *
690 * [Report a reduced congestion window back to where the ECNE
691 * came from.]
692 */
693 if (chunk)
694 retval->transport = chunk->transport;
695
696nodata:
697 return retval;
698}
699
700/* Make an ECNE chunk. This is a congestion experienced report. */
701struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc,
702 const __u32 lowest_tsn)
703{
704 struct sctp_chunk *retval;
705 struct sctp_ecnehdr ecne;
706
707 ecne.lowest_tsn = htonl(lowest_tsn);
708 retval = sctp_make_control(asoc, SCTP_CID_ECN_ECNE, 0,
709 sizeof(ecne), GFP_ATOMIC);
710 if (!retval)
711 goto nodata;
712 retval->subh.ecne_hdr =
713 sctp_addto_chunk(retval, sizeof(ecne), &ecne);
714
715nodata:
716 return retval;
717}
718
719/* Make a DATA chunk for the given association from the provided
720 * parameters. However, do not populate the data payload.
721 */
722struct sctp_chunk *sctp_make_datafrag_empty(const struct sctp_association *asoc,
723 const struct sctp_sndrcvinfo *sinfo,
724 int len, __u8 flags, gfp_t gfp)
725{
726 struct sctp_chunk *retval;
727 struct sctp_datahdr dp;
728
729 /* We assign the TSN as LATE as possible, not here when
730 * creating the chunk.
731 */
732 memset(&dp, 0, sizeof(dp));
733 dp.ppid = sinfo->sinfo_ppid;
734 dp.stream = htons(sinfo->sinfo_stream);
735
736 /* Set the flags for an unordered send. */
737 if (sinfo->sinfo_flags & SCTP_UNORDERED)
738 flags |= SCTP_DATA_UNORDERED;
739
740 retval = sctp_make_data(asoc, flags, sizeof(dp) + len, gfp);
741 if (!retval)
742 return NULL;
743
744 retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp);
745 memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo));
746
747 return retval;
748}
749
750/* Create a selective ackowledgement (SACK) for the given
751 * association. This reports on which TSN's we've seen to date,
752 * including duplicates and gaps.
753 */
754struct sctp_chunk *sctp_make_sack(struct sctp_association *asoc)
755{
756 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
757 struct sctp_gap_ack_block gabs[SCTP_MAX_GABS];
758 __u16 num_gabs, num_dup_tsns;
759 struct sctp_transport *trans;
760 struct sctp_chunk *retval;
761 struct sctp_sackhdr sack;
762 __u32 ctsn;
763 int len;
764
765 memset(gabs, 0, sizeof(gabs));
766 ctsn = sctp_tsnmap_get_ctsn(map);
767
768 pr_debug("%s: sackCTSNAck sent:0x%x\n", __func__, ctsn);
769
770 /* How much room is needed in the chunk? */
771 num_gabs = sctp_tsnmap_num_gabs(map, gabs);
772 num_dup_tsns = sctp_tsnmap_num_dups(map);
773
774 /* Initialize the SACK header. */
775 sack.cum_tsn_ack = htonl(ctsn);
776 sack.a_rwnd = htonl(asoc->a_rwnd);
777 sack.num_gap_ack_blocks = htons(num_gabs);
778 sack.num_dup_tsns = htons(num_dup_tsns);
779
780 len = sizeof(sack)
781 + sizeof(struct sctp_gap_ack_block) * num_gabs
782 + sizeof(__u32) * num_dup_tsns;
783
784 /* Create the chunk. */
785 retval = sctp_make_control(asoc, SCTP_CID_SACK, 0, len, GFP_ATOMIC);
786 if (!retval)
787 goto nodata;
788
789 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
790 *
791 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
792 * HEARTBEAT ACK, etc.) to the same destination transport
793 * address from which it received the DATA or control chunk to
794 * which it is replying. This rule should also be followed if
795 * the endpoint is bundling DATA chunks together with the
796 * reply chunk.
797 *
798 * However, when acknowledging multiple DATA chunks received
799 * in packets from different source addresses in a single
800 * SACK, the SACK chunk may be transmitted to one of the
801 * destination transport addresses from which the DATA or
802 * control chunks being acknowledged were received.
803 *
804 * [BUG: We do not implement the following paragraph.
805 * Perhaps we should remember the last transport we used for a
806 * SACK and avoid that (if possible) if we have seen any
807 * duplicates. --piggy]
808 *
809 * When a receiver of a duplicate DATA chunk sends a SACK to a
810 * multi- homed endpoint it MAY be beneficial to vary the
811 * destination address and not use the source address of the
812 * DATA chunk. The reason being that receiving a duplicate
813 * from a multi-homed endpoint might indicate that the return
814 * path (as specified in the source address of the DATA chunk)
815 * for the SACK is broken.
816 *
817 * [Send to the address from which we last received a DATA chunk.]
818 */
819 retval->transport = asoc->peer.last_data_from;
820
821 retval->subh.sack_hdr =
822 sctp_addto_chunk(retval, sizeof(sack), &sack);
823
824 /* Add the gap ack block information. */
825 if (num_gabs)
826 sctp_addto_chunk(retval, sizeof(__u32) * num_gabs,
827 gabs);
828
829 /* Add the duplicate TSN information. */
830 if (num_dup_tsns) {
831 asoc->stats.idupchunks += num_dup_tsns;
832 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns,
833 sctp_tsnmap_get_dups(map));
834 }
835 /* Once we have a sack generated, check to see what our sack
836 * generation is, if its 0, reset the transports to 0, and reset
837 * the association generation to 1
838 *
839 * The idea is that zero is never used as a valid generation for the
840 * association so no transport will match after a wrap event like this,
841 * Until the next sack
842 */
843 if (++asoc->peer.sack_generation == 0) {
844 list_for_each_entry(trans, &asoc->peer.transport_addr_list,
845 transports)
846 trans->sack_generation = 0;
847 asoc->peer.sack_generation = 1;
848 }
849nodata:
850 return retval;
851}
852
853/* Make a SHUTDOWN chunk. */
854struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc,
855 const struct sctp_chunk *chunk)
856{
857 struct sctp_shutdownhdr shut;
858 struct sctp_chunk *retval;
859 __u32 ctsn;
860
861 if (chunk && chunk->asoc)
862 ctsn = sctp_tsnmap_get_ctsn(&chunk->asoc->peer.tsn_map);
863 else
864 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
865
866 shut.cum_tsn_ack = htonl(ctsn);
867
868 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN, 0,
869 sizeof(shut), GFP_ATOMIC);
870 if (!retval)
871 goto nodata;
872
873 retval->subh.shutdown_hdr =
874 sctp_addto_chunk(retval, sizeof(shut), &shut);
875
876 if (chunk)
877 retval->transport = chunk->transport;
878nodata:
879 return retval;
880}
881
882struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc,
883 const struct sctp_chunk *chunk)
884{
885 struct sctp_chunk *retval;
886
887 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0,
888 GFP_ATOMIC);
889
890 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
891 *
892 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
893 * HEARTBEAT ACK, * etc.) to the same destination transport
894 * address from which it * received the DATA or control chunk
895 * to which it is replying.
896 *
897 * [ACK back to where the SHUTDOWN came from.]
898 */
899 if (retval && chunk)
900 retval->transport = chunk->transport;
901
902 return retval;
903}
904
905struct sctp_chunk *sctp_make_shutdown_complete(
906 const struct sctp_association *asoc,
907 const struct sctp_chunk *chunk)
908{
909 struct sctp_chunk *retval;
910 __u8 flags = 0;
911
912 /* Set the T-bit if we have no association (vtag will be
913 * reflected)
914 */
915 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T;
916
917 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags,
918 0, GFP_ATOMIC);
919
920 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
921 *
922 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
923 * HEARTBEAT ACK, * etc.) to the same destination transport
924 * address from which it * received the DATA or control chunk
925 * to which it is replying.
926 *
927 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK
928 * came from.]
929 */
930 if (retval && chunk)
931 retval->transport = chunk->transport;
932
933 return retval;
934}
935
936/* Create an ABORT. Note that we set the T bit if we have no
937 * association, except when responding to an INIT (sctpimpguide 2.41).
938 */
939struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc,
940 const struct sctp_chunk *chunk,
941 const size_t hint)
942{
943 struct sctp_chunk *retval;
944 __u8 flags = 0;
945
946 /* Set the T-bit if we have no association and 'chunk' is not
947 * an INIT (vtag will be reflected).
948 */
949 if (!asoc) {
950 if (chunk && chunk->chunk_hdr &&
951 chunk->chunk_hdr->type == SCTP_CID_INIT)
952 flags = 0;
953 else
954 flags = SCTP_CHUNK_FLAG_T;
955 }
956
957 retval = sctp_make_control(asoc, SCTP_CID_ABORT, flags, hint,
958 GFP_ATOMIC);
959
960 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
961 *
962 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
963 * HEARTBEAT ACK, * etc.) to the same destination transport
964 * address from which it * received the DATA or control chunk
965 * to which it is replying.
966 *
967 * [ABORT back to where the offender came from.]
968 */
969 if (retval && chunk)
970 retval->transport = chunk->transport;
971
972 return retval;
973}
974
975/* Helper to create ABORT with a NO_USER_DATA error. */
976struct sctp_chunk *sctp_make_abort_no_data(
977 const struct sctp_association *asoc,
978 const struct sctp_chunk *chunk,
979 __u32 tsn)
980{
981 struct sctp_chunk *retval;
982 __be32 payload;
983
984 retval = sctp_make_abort(asoc, chunk,
985 sizeof(struct sctp_errhdr) + sizeof(tsn));
986
987 if (!retval)
988 goto no_mem;
989
990 /* Put the tsn back into network byte order. */
991 payload = htonl(tsn);
992 sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload));
993 sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload);
994
995 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
996 *
997 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
998 * HEARTBEAT ACK, * etc.) to the same destination transport
999 * address from which it * received the DATA or control chunk
1000 * to which it is replying.
1001 *
1002 * [ABORT back to where the offender came from.]
1003 */
1004 if (chunk)
1005 retval->transport = chunk->transport;
1006
1007no_mem:
1008 return retval;
1009}
1010
1011/* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */
1012struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc,
1013 struct msghdr *msg,
1014 size_t paylen)
1015{
1016 struct sctp_chunk *retval;
1017 void *payload = NULL;
1018 int err;
1019
1020 retval = sctp_make_abort(asoc, NULL,
1021 sizeof(struct sctp_errhdr) + paylen);
1022 if (!retval)
1023 goto err_chunk;
1024
1025 if (paylen) {
1026 /* Put the msg_iov together into payload. */
1027 payload = kmalloc(paylen, GFP_KERNEL);
1028 if (!payload)
1029 goto err_payload;
1030
1031 err = memcpy_from_msg(payload, msg, paylen);
1032 if (err < 0)
1033 goto err_copy;
1034 }
1035
1036 sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen);
1037 sctp_addto_chunk(retval, paylen, payload);
1038
1039 if (paylen)
1040 kfree(payload);
1041
1042 return retval;
1043
1044err_copy:
1045 kfree(payload);
1046err_payload:
1047 sctp_chunk_free(retval);
1048 retval = NULL;
1049err_chunk:
1050 return retval;
1051}
1052
1053/* Append bytes to the end of a parameter. Will panic if chunk is not big
1054 * enough.
1055 */
1056static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
1057 const void *data)
1058{
1059 int chunklen = ntohs(chunk->chunk_hdr->length);
1060 void *target;
1061
1062 target = skb_put(chunk->skb, len);
1063
1064 if (data)
1065 memcpy(target, data, len);
1066 else
1067 memset(target, 0, len);
1068
1069 /* Adjust the chunk length field. */
1070 chunk->chunk_hdr->length = htons(chunklen + len);
1071 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1072
1073 return target;
1074}
1075
1076/* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */
1077struct sctp_chunk *sctp_make_abort_violation(
1078 const struct sctp_association *asoc,
1079 const struct sctp_chunk *chunk,
1080 const __u8 *payload,
1081 const size_t paylen)
1082{
1083 struct sctp_chunk *retval;
1084 struct sctp_paramhdr phdr;
1085
1086 retval = sctp_make_abort(asoc, chunk, sizeof(struct sctp_errhdr) +
1087 paylen + sizeof(phdr));
1088 if (!retval)
1089 goto end;
1090
1091 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen +
1092 sizeof(phdr));
1093
1094 phdr.type = htons(chunk->chunk_hdr->type);
1095 phdr.length = chunk->chunk_hdr->length;
1096 sctp_addto_chunk(retval, paylen, payload);
1097 sctp_addto_param(retval, sizeof(phdr), &phdr);
1098
1099end:
1100 return retval;
1101}
1102
1103struct sctp_chunk *sctp_make_violation_paramlen(
1104 const struct sctp_association *asoc,
1105 const struct sctp_chunk *chunk,
1106 struct sctp_paramhdr *param)
1107{
1108 static const char error[] = "The following parameter had invalid length:";
1109 size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr) +
1110 sizeof(*param);
1111 struct sctp_chunk *retval;
1112
1113 retval = sctp_make_abort(asoc, chunk, payload_len);
1114 if (!retval)
1115 goto nodata;
1116
1117 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION,
1118 sizeof(error) + sizeof(*param));
1119 sctp_addto_chunk(retval, sizeof(error), error);
1120 sctp_addto_param(retval, sizeof(*param), param);
1121
1122nodata:
1123 return retval;
1124}
1125
1126struct sctp_chunk *sctp_make_violation_max_retrans(
1127 const struct sctp_association *asoc,
1128 const struct sctp_chunk *chunk)
1129{
1130 static const char error[] = "Association exceeded its max_retrans count";
1131 size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr);
1132 struct sctp_chunk *retval;
1133
1134 retval = sctp_make_abort(asoc, chunk, payload_len);
1135 if (!retval)
1136 goto nodata;
1137
1138 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error));
1139 sctp_addto_chunk(retval, sizeof(error), error);
1140
1141nodata:
1142 return retval;
1143}
1144
1145/* Make a HEARTBEAT chunk. */
1146struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc,
1147 const struct sctp_transport *transport)
1148{
1149 struct sctp_sender_hb_info hbinfo;
1150 struct sctp_chunk *retval;
1151
1152 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT, 0,
1153 sizeof(hbinfo), GFP_ATOMIC);
1154
1155 if (!retval)
1156 goto nodata;
1157
1158 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO;
1159 hbinfo.param_hdr.length = htons(sizeof(hbinfo));
1160 hbinfo.daddr = transport->ipaddr;
1161 hbinfo.sent_at = jiffies;
1162 hbinfo.hb_nonce = transport->hb_nonce;
1163
1164 /* Cast away the 'const', as this is just telling the chunk
1165 * what transport it belongs to.
1166 */
1167 retval->transport = (struct sctp_transport *) transport;
1168 retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo),
1169 &hbinfo);
1170
1171nodata:
1172 return retval;
1173}
1174
1175struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc,
1176 const struct sctp_chunk *chunk,
1177 const void *payload,
1178 const size_t paylen)
1179{
1180 struct sctp_chunk *retval;
1181
1182 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen,
1183 GFP_ATOMIC);
1184 if (!retval)
1185 goto nodata;
1186
1187 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload);
1188
1189 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
1190 *
1191 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1192 * HEARTBEAT ACK, * etc.) to the same destination transport
1193 * address from which it * received the DATA or control chunk
1194 * to which it is replying.
1195 *
1196 * [HBACK back to where the HEARTBEAT came from.]
1197 */
1198 if (chunk)
1199 retval->transport = chunk->transport;
1200
1201nodata:
1202 return retval;
1203}
1204
1205/* Create an Operation Error chunk with the specified space reserved.
1206 * This routine can be used for containing multiple causes in the chunk.
1207 */
1208static struct sctp_chunk *sctp_make_op_error_space(
1209 const struct sctp_association *asoc,
1210 const struct sctp_chunk *chunk,
1211 size_t size)
1212{
1213 struct sctp_chunk *retval;
1214
1215 retval = sctp_make_control(asoc, SCTP_CID_ERROR, 0,
1216 sizeof(struct sctp_errhdr) + size,
1217 GFP_ATOMIC);
1218 if (!retval)
1219 goto nodata;
1220
1221 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
1222 *
1223 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1224 * HEARTBEAT ACK, etc.) to the same destination transport
1225 * address from which it received the DATA or control chunk
1226 * to which it is replying.
1227 *
1228 */
1229 if (chunk)
1230 retval->transport = chunk->transport;
1231
1232nodata:
1233 return retval;
1234}
1235
1236/* Create an Operation Error chunk of a fixed size, specifically,
1237 * min(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT) - overheads.
1238 * This is a helper function to allocate an error chunk for for those
1239 * invalid parameter codes in which we may not want to report all the
1240 * errors, if the incoming chunk is large. If it can't fit in a single
1241 * packet, we ignore it.
1242 */
1243static inline struct sctp_chunk *sctp_make_op_error_limited(
1244 const struct sctp_association *asoc,
1245 const struct sctp_chunk *chunk)
1246{
1247 size_t size = SCTP_DEFAULT_MAXSEGMENT;
1248 struct sctp_sock *sp = NULL;
1249
1250 if (asoc) {
1251 size = min_t(size_t, size, asoc->pathmtu);
1252 sp = sctp_sk(asoc->base.sk);
1253 }
1254
1255 size = sctp_mtu_payload(sp, size, sizeof(struct sctp_errhdr));
1256
1257 return sctp_make_op_error_space(asoc, chunk, size);
1258}
1259
1260/* Create an Operation Error chunk. */
1261struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc,
1262 const struct sctp_chunk *chunk,
1263 __be16 cause_code, const void *payload,
1264 size_t paylen, size_t reserve_tail)
1265{
1266 struct sctp_chunk *retval;
1267
1268 retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail);
1269 if (!retval)
1270 goto nodata;
1271
1272 sctp_init_cause(retval, cause_code, paylen + reserve_tail);
1273 sctp_addto_chunk(retval, paylen, payload);
1274 if (reserve_tail)
1275 sctp_addto_param(retval, reserve_tail, NULL);
1276
1277nodata:
1278 return retval;
1279}
1280
1281struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc,
1282 __u16 key_id)
1283{
1284 struct sctp_authhdr auth_hdr;
1285 struct sctp_hmac *hmac_desc;
1286 struct sctp_chunk *retval;
1287
1288 /* Get the first hmac that the peer told us to use */
1289 hmac_desc = sctp_auth_asoc_get_hmac(asoc);
1290 if (unlikely(!hmac_desc))
1291 return NULL;
1292
1293 retval = sctp_make_control(asoc, SCTP_CID_AUTH, 0,
1294 hmac_desc->hmac_len + sizeof(auth_hdr),
1295 GFP_ATOMIC);
1296 if (!retval)
1297 return NULL;
1298
1299 auth_hdr.hmac_id = htons(hmac_desc->hmac_id);
1300 auth_hdr.shkey_id = htons(key_id);
1301
1302 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(auth_hdr),
1303 &auth_hdr);
1304
1305 skb_put_zero(retval->skb, hmac_desc->hmac_len);
1306
1307 /* Adjust the chunk header to include the empty MAC */
1308 retval->chunk_hdr->length =
1309 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len);
1310 retval->chunk_end = skb_tail_pointer(retval->skb);
1311
1312 return retval;
1313}
1314
1315
1316/********************************************************************
1317 * 2nd Level Abstractions
1318 ********************************************************************/
1319
1320/* Turn an skb into a chunk.
1321 * FIXME: Eventually move the structure directly inside the skb->cb[].
1322 *
1323 * sctpimpguide-05.txt Section 2.8.2
1324 * M1) Each time a new DATA chunk is transmitted
1325 * set the 'TSN.Missing.Report' count for that TSN to 0. The
1326 * 'TSN.Missing.Report' count will be used to determine missing chunks
1327 * and when to fast retransmit.
1328 *
1329 */
1330struct sctp_chunk *sctp_chunkify(struct sk_buff *skb,
1331 const struct sctp_association *asoc,
1332 struct sock *sk, gfp_t gfp)
1333{
1334 struct sctp_chunk *retval;
1335
1336 retval = kmem_cache_zalloc(sctp_chunk_cachep, gfp);
1337
1338 if (!retval)
1339 goto nodata;
1340 if (!sk)
1341 pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb);
1342
1343 INIT_LIST_HEAD(&retval->list);
1344 retval->skb = skb;
1345 retval->asoc = (struct sctp_association *)asoc;
1346 retval->singleton = 1;
1347
1348 retval->fast_retransmit = SCTP_CAN_FRTX;
1349
1350 /* Polish the bead hole. */
1351 INIT_LIST_HEAD(&retval->transmitted_list);
1352 INIT_LIST_HEAD(&retval->frag_list);
1353 SCTP_DBG_OBJCNT_INC(chunk);
1354 refcount_set(&retval->refcnt, 1);
1355
1356nodata:
1357 return retval;
1358}
1359
1360/* Set chunk->source and dest based on the IP header in chunk->skb. */
1361void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src,
1362 union sctp_addr *dest)
1363{
1364 memcpy(&chunk->source, src, sizeof(union sctp_addr));
1365 memcpy(&chunk->dest, dest, sizeof(union sctp_addr));
1366}
1367
1368/* Extract the source address from a chunk. */
1369const union sctp_addr *sctp_source(const struct sctp_chunk *chunk)
1370{
1371 /* If we have a known transport, use that. */
1372 if (chunk->transport) {
1373 return &chunk->transport->ipaddr;
1374 } else {
1375 /* Otherwise, extract it from the IP header. */
1376 return &chunk->source;
1377 }
1378}
1379
1380/* Create a new chunk, setting the type and flags headers from the
1381 * arguments, reserving enough space for a 'paylen' byte payload.
1382 */
1383static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc,
1384 __u8 type, __u8 flags, int paylen,
1385 gfp_t gfp)
1386{
1387 struct sctp_chunkhdr *chunk_hdr;
1388 struct sctp_chunk *retval;
1389 struct sk_buff *skb;
1390 struct sock *sk;
1391 int chunklen;
1392
1393 chunklen = SCTP_PAD4(sizeof(*chunk_hdr) + paylen);
1394 if (chunklen > SCTP_MAX_CHUNK_LEN)
1395 goto nodata;
1396
1397 /* No need to allocate LL here, as this is only a chunk. */
1398 skb = alloc_skb(chunklen, gfp);
1399 if (!skb)
1400 goto nodata;
1401
1402 /* Make room for the chunk header. */
1403 chunk_hdr = (struct sctp_chunkhdr *)skb_put(skb, sizeof(*chunk_hdr));
1404 chunk_hdr->type = type;
1405 chunk_hdr->flags = flags;
1406 chunk_hdr->length = htons(sizeof(*chunk_hdr));
1407
1408 sk = asoc ? asoc->base.sk : NULL;
1409 retval = sctp_chunkify(skb, asoc, sk, gfp);
1410 if (!retval) {
1411 kfree_skb(skb);
1412 goto nodata;
1413 }
1414
1415 retval->chunk_hdr = chunk_hdr;
1416 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(*chunk_hdr);
1417
1418 /* Determine if the chunk needs to be authenticated */
1419 if (sctp_auth_send_cid(type, asoc))
1420 retval->auth = 1;
1421
1422 return retval;
1423nodata:
1424 return NULL;
1425}
1426
1427static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc,
1428 __u8 flags, int paylen, gfp_t gfp)
1429{
1430 return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen, gfp);
1431}
1432
1433struct sctp_chunk *sctp_make_idata(const struct sctp_association *asoc,
1434 __u8 flags, int paylen, gfp_t gfp)
1435{
1436 return _sctp_make_chunk(asoc, SCTP_CID_I_DATA, flags, paylen, gfp);
1437}
1438
1439static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc,
1440 __u8 type, __u8 flags, int paylen,
1441 gfp_t gfp)
1442{
1443 struct sctp_chunk *chunk;
1444
1445 chunk = _sctp_make_chunk(asoc, type, flags, paylen, gfp);
1446 if (chunk)
1447 sctp_control_set_owner_w(chunk);
1448
1449 return chunk;
1450}
1451
1452/* Release the memory occupied by a chunk. */
1453static void sctp_chunk_destroy(struct sctp_chunk *chunk)
1454{
1455 BUG_ON(!list_empty(&chunk->list));
1456 list_del_init(&chunk->transmitted_list);
1457
1458 consume_skb(chunk->skb);
1459 consume_skb(chunk->auth_chunk);
1460
1461 SCTP_DBG_OBJCNT_DEC(chunk);
1462 kmem_cache_free(sctp_chunk_cachep, chunk);
1463}
1464
1465/* Possibly, free the chunk. */
1466void sctp_chunk_free(struct sctp_chunk *chunk)
1467{
1468 /* Release our reference on the message tracker. */
1469 if (chunk->msg)
1470 sctp_datamsg_put(chunk->msg);
1471
1472 sctp_chunk_put(chunk);
1473}
1474
1475/* Grab a reference to the chunk. */
1476void sctp_chunk_hold(struct sctp_chunk *ch)
1477{
1478 refcount_inc(&ch->refcnt);
1479}
1480
1481/* Release a reference to the chunk. */
1482void sctp_chunk_put(struct sctp_chunk *ch)
1483{
1484 if (refcount_dec_and_test(&ch->refcnt))
1485 sctp_chunk_destroy(ch);
1486}
1487
1488/* Append bytes to the end of a chunk. Will panic if chunk is not big
1489 * enough.
1490 */
1491void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data)
1492{
1493 int chunklen = ntohs(chunk->chunk_hdr->length);
1494 int padlen = SCTP_PAD4(chunklen) - chunklen;
1495 void *target;
1496
1497 skb_put_zero(chunk->skb, padlen);
1498 target = skb_put_data(chunk->skb, data, len);
1499
1500 /* Adjust the chunk length field. */
1501 chunk->chunk_hdr->length = htons(chunklen + padlen + len);
1502 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1503
1504 return target;
1505}
1506
1507/* Append bytes from user space to the end of a chunk. Will panic if
1508 * chunk is not big enough.
1509 * Returns a kernel err value.
1510 */
1511int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
1512 struct iov_iter *from)
1513{
1514 void *target;
1515
1516 /* Make room in chunk for data. */
1517 target = skb_put(chunk->skb, len);
1518
1519 /* Copy data (whole iovec) into chunk */
1520 if (!copy_from_iter_full(target, len, from))
1521 return -EFAULT;
1522
1523 /* Adjust the chunk length field. */
1524 chunk->chunk_hdr->length =
1525 htons(ntohs(chunk->chunk_hdr->length) + len);
1526 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1527
1528 return 0;
1529}
1530
1531/* Helper function to assign a TSN if needed. This assumes that both
1532 * the data_hdr and association have already been assigned.
1533 */
1534void sctp_chunk_assign_ssn(struct sctp_chunk *chunk)
1535{
1536 struct sctp_stream *stream;
1537 struct sctp_chunk *lchunk;
1538 struct sctp_datamsg *msg;
1539 __u16 ssn, sid;
1540
1541 if (chunk->has_ssn)
1542 return;
1543
1544 /* All fragments will be on the same stream */
1545 sid = ntohs(chunk->subh.data_hdr->stream);
1546 stream = &chunk->asoc->stream;
1547
1548 /* Now assign the sequence number to the entire message.
1549 * All fragments must have the same stream sequence number.
1550 */
1551 msg = chunk->msg;
1552 list_for_each_entry(lchunk, &msg->chunks, frag_list) {
1553 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
1554 ssn = 0;
1555 } else {
1556 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG)
1557 ssn = sctp_ssn_next(stream, out, sid);
1558 else
1559 ssn = sctp_ssn_peek(stream, out, sid);
1560 }
1561
1562 lchunk->subh.data_hdr->ssn = htons(ssn);
1563 lchunk->has_ssn = 1;
1564 }
1565}
1566
1567/* Helper function to assign a TSN if needed. This assumes that both
1568 * the data_hdr and association have already been assigned.
1569 */
1570void sctp_chunk_assign_tsn(struct sctp_chunk *chunk)
1571{
1572 if (!chunk->has_tsn) {
1573 /* This is the last possible instant to
1574 * assign a TSN.
1575 */
1576 chunk->subh.data_hdr->tsn =
1577 htonl(sctp_association_get_next_tsn(chunk->asoc));
1578 chunk->has_tsn = 1;
1579 }
1580}
1581
1582/* Create a CLOSED association to use with an incoming packet. */
1583struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep,
1584 struct sctp_chunk *chunk,
1585 gfp_t gfp)
1586{
1587 struct sctp_association *asoc;
1588 enum sctp_scope scope;
1589 struct sk_buff *skb;
1590
1591 /* Create the bare association. */
1592 scope = sctp_scope(sctp_source(chunk));
1593 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp);
1594 if (!asoc)
1595 goto nodata;
1596 asoc->temp = 1;
1597 skb = chunk->skb;
1598 /* Create an entry for the source address of the packet. */
1599 SCTP_INPUT_CB(skb)->af->from_skb(&asoc->c.peer_addr, skb, 1);
1600
1601nodata:
1602 return asoc;
1603}
1604
1605/* Build a cookie representing asoc.
1606 * This INCLUDES the param header needed to put the cookie in the INIT ACK.
1607 */
1608static struct sctp_cookie_param *sctp_pack_cookie(
1609 const struct sctp_endpoint *ep,
1610 const struct sctp_association *asoc,
1611 const struct sctp_chunk *init_chunk,
1612 int *cookie_len, const __u8 *raw_addrs,
1613 int addrs_len)
1614{
1615 struct sctp_signed_cookie *cookie;
1616 struct sctp_cookie_param *retval;
1617 int headersize, bodysize;
1618
1619 /* Header size is static data prior to the actual cookie, including
1620 * any padding.
1621 */
1622 headersize = sizeof(struct sctp_paramhdr) +
1623 (sizeof(struct sctp_signed_cookie) -
1624 sizeof(struct sctp_cookie));
1625 bodysize = sizeof(struct sctp_cookie)
1626 + ntohs(init_chunk->chunk_hdr->length) + addrs_len;
1627
1628 /* Pad out the cookie to a multiple to make the signature
1629 * functions simpler to write.
1630 */
1631 if (bodysize % SCTP_COOKIE_MULTIPLE)
1632 bodysize += SCTP_COOKIE_MULTIPLE
1633 - (bodysize % SCTP_COOKIE_MULTIPLE);
1634 *cookie_len = headersize + bodysize;
1635
1636 /* Clear this memory since we are sending this data structure
1637 * out on the network.
1638 */
1639 retval = kzalloc(*cookie_len, GFP_ATOMIC);
1640 if (!retval)
1641 goto nodata;
1642
1643 cookie = (struct sctp_signed_cookie *) retval->body;
1644
1645 /* Set up the parameter header. */
1646 retval->p.type = SCTP_PARAM_STATE_COOKIE;
1647 retval->p.length = htons(*cookie_len);
1648
1649 /* Copy the cookie part of the association itself. */
1650 cookie->c = asoc->c;
1651 /* Save the raw address list length in the cookie. */
1652 cookie->c.raw_addr_list_len = addrs_len;
1653
1654 /* Remember PR-SCTP capability. */
1655 cookie->c.prsctp_capable = asoc->peer.prsctp_capable;
1656
1657 /* Save adaptation indication in the cookie. */
1658 cookie->c.adaptation_ind = asoc->peer.adaptation_ind;
1659
1660 /* Set an expiration time for the cookie. */
1661 cookie->c.expiration = ktime_add(asoc->cookie_life,
1662 ktime_get_real());
1663
1664 /* Copy the peer's init packet. */
1665 memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr,
1666 ntohs(init_chunk->chunk_hdr->length));
1667
1668 /* Copy the raw local address list of the association. */
1669 memcpy((__u8 *)&cookie->c.peer_init[0] +
1670 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len);
1671
1672 if (sctp_sk(ep->base.sk)->hmac) {
1673 struct crypto_shash *tfm = sctp_sk(ep->base.sk)->hmac;
1674 int err;
1675
1676 /* Sign the message. */
1677 err = crypto_shash_setkey(tfm, ep->secret_key,
1678 sizeof(ep->secret_key)) ?:
1679 crypto_shash_tfm_digest(tfm, (u8 *)&cookie->c, bodysize,
1680 cookie->signature);
1681 if (err)
1682 goto free_cookie;
1683 }
1684
1685 return retval;
1686
1687free_cookie:
1688 kfree(retval);
1689nodata:
1690 *cookie_len = 0;
1691 return NULL;
1692}
1693
1694/* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */
1695struct sctp_association *sctp_unpack_cookie(
1696 const struct sctp_endpoint *ep,
1697 const struct sctp_association *asoc,
1698 struct sctp_chunk *chunk, gfp_t gfp,
1699 int *error, struct sctp_chunk **errp)
1700{
1701 struct sctp_association *retval = NULL;
1702 int headersize, bodysize, fixed_size;
1703 struct sctp_signed_cookie *cookie;
1704 struct sk_buff *skb = chunk->skb;
1705 struct sctp_cookie *bear_cookie;
1706 __u8 *digest = ep->digest;
1707 enum sctp_scope scope;
1708 unsigned int len;
1709 ktime_t kt;
1710
1711 /* Header size is static data prior to the actual cookie, including
1712 * any padding.
1713 */
1714 headersize = sizeof(struct sctp_chunkhdr) +
1715 (sizeof(struct sctp_signed_cookie) -
1716 sizeof(struct sctp_cookie));
1717 bodysize = ntohs(chunk->chunk_hdr->length) - headersize;
1718 fixed_size = headersize + sizeof(struct sctp_cookie);
1719
1720 /* Verify that the chunk looks like it even has a cookie.
1721 * There must be enough room for our cookie and our peer's
1722 * INIT chunk.
1723 */
1724 len = ntohs(chunk->chunk_hdr->length);
1725 if (len < fixed_size + sizeof(struct sctp_chunkhdr))
1726 goto malformed;
1727
1728 /* Verify that the cookie has been padded out. */
1729 if (bodysize % SCTP_COOKIE_MULTIPLE)
1730 goto malformed;
1731
1732 /* Process the cookie. */
1733 cookie = chunk->subh.cookie_hdr;
1734 bear_cookie = &cookie->c;
1735
1736 if (!sctp_sk(ep->base.sk)->hmac)
1737 goto no_hmac;
1738
1739 /* Check the signature. */
1740 {
1741 struct crypto_shash *tfm = sctp_sk(ep->base.sk)->hmac;
1742 int err;
1743
1744 err = crypto_shash_setkey(tfm, ep->secret_key,
1745 sizeof(ep->secret_key)) ?:
1746 crypto_shash_tfm_digest(tfm, (u8 *)bear_cookie, bodysize,
1747 digest);
1748 if (err) {
1749 *error = -SCTP_IERROR_NOMEM;
1750 goto fail;
1751 }
1752 }
1753
1754 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
1755 *error = -SCTP_IERROR_BAD_SIG;
1756 goto fail;
1757 }
1758
1759no_hmac:
1760 /* IG Section 2.35.2:
1761 * 3) Compare the port numbers and the verification tag contained
1762 * within the COOKIE ECHO chunk to the actual port numbers and the
1763 * verification tag within the SCTP common header of the received
1764 * packet. If these values do not match the packet MUST be silently
1765 * discarded,
1766 */
1767 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) {
1768 *error = -SCTP_IERROR_BAD_TAG;
1769 goto fail;
1770 }
1771
1772 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port ||
1773 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) {
1774 *error = -SCTP_IERROR_BAD_PORTS;
1775 goto fail;
1776 }
1777
1778 /* Check to see if the cookie is stale. If there is already
1779 * an association, there is no need to check cookie's expiration
1780 * for init collision case of lost COOKIE ACK.
1781 * If skb has been timestamped, then use the stamp, otherwise
1782 * use current time. This introduces a small possibility that
1783 * that a cookie may be considered expired, but his would only slow
1784 * down the new association establishment instead of every packet.
1785 */
1786 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP))
1787 kt = skb_get_ktime(skb);
1788 else
1789 kt = ktime_get_real();
1790
1791 if (!asoc && ktime_before(bear_cookie->expiration, kt)) {
1792 suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration));
1793 __be32 n = htonl(usecs);
1794
1795 /*
1796 * Section 3.3.10.3 Stale Cookie Error (3)
1797 *
1798 * Cause of error
1799 * ---------------
1800 * Stale Cookie Error: Indicates the receipt of a valid State
1801 * Cookie that has expired.
1802 */
1803 *errp = sctp_make_op_error(asoc, chunk,
1804 SCTP_ERROR_STALE_COOKIE, &n,
1805 sizeof(n), 0);
1806 if (*errp)
1807 *error = -SCTP_IERROR_STALE_COOKIE;
1808 else
1809 *error = -SCTP_IERROR_NOMEM;
1810
1811 goto fail;
1812 }
1813
1814 /* Make a new base association. */
1815 scope = sctp_scope(sctp_source(chunk));
1816 retval = sctp_association_new(ep, ep->base.sk, scope, gfp);
1817 if (!retval) {
1818 *error = -SCTP_IERROR_NOMEM;
1819 goto fail;
1820 }
1821
1822 /* Set up our peer's port number. */
1823 retval->peer.port = ntohs(chunk->sctp_hdr->source);
1824
1825 /* Populate the association from the cookie. */
1826 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie));
1827
1828 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie,
1829 GFP_ATOMIC) < 0) {
1830 *error = -SCTP_IERROR_NOMEM;
1831 goto fail;
1832 }
1833
1834 /* Also, add the destination address. */
1835 if (list_empty(&retval->base.bind_addr.address_list)) {
1836 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest,
1837 sizeof(chunk->dest), SCTP_ADDR_SRC,
1838 GFP_ATOMIC);
1839 }
1840
1841 retval->next_tsn = retval->c.initial_tsn;
1842 retval->ctsn_ack_point = retval->next_tsn - 1;
1843 retval->addip_serial = retval->c.initial_tsn;
1844 retval->strreset_outseq = retval->c.initial_tsn;
1845 retval->adv_peer_ack_point = retval->ctsn_ack_point;
1846 retval->peer.prsctp_capable = retval->c.prsctp_capable;
1847 retval->peer.adaptation_ind = retval->c.adaptation_ind;
1848
1849 /* The INIT stuff will be done by the side effects. */
1850 return retval;
1851
1852fail:
1853 if (retval)
1854 sctp_association_free(retval);
1855
1856 return NULL;
1857
1858malformed:
1859 /* Yikes! The packet is either corrupt or deliberately
1860 * malformed.
1861 */
1862 *error = -SCTP_IERROR_MALFORMED;
1863 goto fail;
1864}
1865
1866/********************************************************************
1867 * 3rd Level Abstractions
1868 ********************************************************************/
1869
1870struct __sctp_missing {
1871 __be32 num_missing;
1872 __be16 type;
1873} __packed;
1874
1875/*
1876 * Report a missing mandatory parameter.
1877 */
1878static int sctp_process_missing_param(const struct sctp_association *asoc,
1879 enum sctp_param paramtype,
1880 struct sctp_chunk *chunk,
1881 struct sctp_chunk **errp)
1882{
1883 struct __sctp_missing report;
1884 __u16 len;
1885
1886 len = SCTP_PAD4(sizeof(report));
1887
1888 /* Make an ERROR chunk, preparing enough room for
1889 * returning multiple unknown parameters.
1890 */
1891 if (!*errp)
1892 *errp = sctp_make_op_error_space(asoc, chunk, len);
1893
1894 if (*errp) {
1895 report.num_missing = htonl(1);
1896 report.type = paramtype;
1897 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM,
1898 sizeof(report));
1899 sctp_addto_chunk(*errp, sizeof(report), &report);
1900 }
1901
1902 /* Stop processing this chunk. */
1903 return 0;
1904}
1905
1906/* Report an Invalid Mandatory Parameter. */
1907static int sctp_process_inv_mandatory(const struct sctp_association *asoc,
1908 struct sctp_chunk *chunk,
1909 struct sctp_chunk **errp)
1910{
1911 /* Invalid Mandatory Parameter Error has no payload. */
1912
1913 if (!*errp)
1914 *errp = sctp_make_op_error_space(asoc, chunk, 0);
1915
1916 if (*errp)
1917 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0);
1918
1919 /* Stop processing this chunk. */
1920 return 0;
1921}
1922
1923static int sctp_process_inv_paramlength(const struct sctp_association *asoc,
1924 struct sctp_paramhdr *param,
1925 const struct sctp_chunk *chunk,
1926 struct sctp_chunk **errp)
1927{
1928 /* This is a fatal error. Any accumulated non-fatal errors are
1929 * not reported.
1930 */
1931 if (*errp)
1932 sctp_chunk_free(*errp);
1933
1934 /* Create an error chunk and fill it in with our payload. */
1935 *errp = sctp_make_violation_paramlen(asoc, chunk, param);
1936
1937 return 0;
1938}
1939
1940
1941/* Do not attempt to handle the HOST_NAME parm. However, do
1942 * send back an indicator to the peer.
1943 */
1944static int sctp_process_hn_param(const struct sctp_association *asoc,
1945 union sctp_params param,
1946 struct sctp_chunk *chunk,
1947 struct sctp_chunk **errp)
1948{
1949 __u16 len = ntohs(param.p->length);
1950
1951 /* Processing of the HOST_NAME parameter will generate an
1952 * ABORT. If we've accumulated any non-fatal errors, they
1953 * would be unrecognized parameters and we should not include
1954 * them in the ABORT.
1955 */
1956 if (*errp)
1957 sctp_chunk_free(*errp);
1958
1959 *errp = sctp_make_op_error(asoc, chunk, SCTP_ERROR_DNS_FAILED,
1960 param.v, len, 0);
1961
1962 /* Stop processing this chunk. */
1963 return 0;
1964}
1965
1966static int sctp_verify_ext_param(struct net *net,
1967 const struct sctp_endpoint *ep,
1968 union sctp_params param)
1969{
1970 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
1971 int have_asconf = 0;
1972 int have_auth = 0;
1973 int i;
1974
1975 for (i = 0; i < num_ext; i++) {
1976 switch (param.ext->chunks[i]) {
1977 case SCTP_CID_AUTH:
1978 have_auth = 1;
1979 break;
1980 case SCTP_CID_ASCONF:
1981 case SCTP_CID_ASCONF_ACK:
1982 have_asconf = 1;
1983 break;
1984 }
1985 }
1986
1987 /* ADD-IP Security: The draft requires us to ABORT or ignore the
1988 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this
1989 * only if ADD-IP is turned on and we are not backward-compatible
1990 * mode.
1991 */
1992 if (net->sctp.addip_noauth)
1993 return 1;
1994
1995 if (ep->asconf_enable && !have_auth && have_asconf)
1996 return 0;
1997
1998 return 1;
1999}
2000
2001static void sctp_process_ext_param(struct sctp_association *asoc,
2002 union sctp_params param)
2003{
2004 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
2005 int i;
2006
2007 for (i = 0; i < num_ext; i++) {
2008 switch (param.ext->chunks[i]) {
2009 case SCTP_CID_RECONF:
2010 if (asoc->ep->reconf_enable)
2011 asoc->peer.reconf_capable = 1;
2012 break;
2013 case SCTP_CID_FWD_TSN:
2014 if (asoc->ep->prsctp_enable)
2015 asoc->peer.prsctp_capable = 1;
2016 break;
2017 case SCTP_CID_AUTH:
2018 /* if the peer reports AUTH, assume that he
2019 * supports AUTH.
2020 */
2021 if (asoc->ep->auth_enable)
2022 asoc->peer.auth_capable = 1;
2023 break;
2024 case SCTP_CID_ASCONF:
2025 case SCTP_CID_ASCONF_ACK:
2026 if (asoc->ep->asconf_enable)
2027 asoc->peer.asconf_capable = 1;
2028 break;
2029 case SCTP_CID_I_DATA:
2030 if (asoc->ep->intl_enable)
2031 asoc->peer.intl_capable = 1;
2032 break;
2033 default:
2034 break;
2035 }
2036 }
2037}
2038
2039/* RFC 3.2.1 & the Implementers Guide 2.2.
2040 *
2041 * The Parameter Types are encoded such that the
2042 * highest-order two bits specify the action that must be
2043 * taken if the processing endpoint does not recognize the
2044 * Parameter Type.
2045 *
2046 * 00 - Stop processing this parameter; do not process any further
2047 * parameters within this chunk
2048 *
2049 * 01 - Stop processing this parameter, do not process any further
2050 * parameters within this chunk, and report the unrecognized
2051 * parameter in an 'Unrecognized Parameter' ERROR chunk.
2052 *
2053 * 10 - Skip this parameter and continue processing.
2054 *
2055 * 11 - Skip this parameter and continue processing but
2056 * report the unrecognized parameter in an
2057 * 'Unrecognized Parameter' ERROR chunk.
2058 *
2059 * Return value:
2060 * SCTP_IERROR_NO_ERROR - continue with the chunk
2061 * SCTP_IERROR_ERROR - stop and report an error.
2062 * SCTP_IERROR_NOMEME - out of memory.
2063 */
2064static enum sctp_ierror sctp_process_unk_param(
2065 const struct sctp_association *asoc,
2066 union sctp_params param,
2067 struct sctp_chunk *chunk,
2068 struct sctp_chunk **errp)
2069{
2070 int retval = SCTP_IERROR_NO_ERROR;
2071
2072 switch (param.p->type & SCTP_PARAM_ACTION_MASK) {
2073 case SCTP_PARAM_ACTION_DISCARD:
2074 retval = SCTP_IERROR_ERROR;
2075 break;
2076 case SCTP_PARAM_ACTION_SKIP:
2077 break;
2078 case SCTP_PARAM_ACTION_DISCARD_ERR:
2079 retval = SCTP_IERROR_ERROR;
2080 fallthrough;
2081 case SCTP_PARAM_ACTION_SKIP_ERR:
2082 /* Make an ERROR chunk, preparing enough room for
2083 * returning multiple unknown parameters.
2084 */
2085 if (!*errp) {
2086 *errp = sctp_make_op_error_limited(asoc, chunk);
2087 if (!*errp) {
2088 /* If there is no memory for generating the
2089 * ERROR report as specified, an ABORT will be
2090 * triggered to the peer and the association
2091 * won't be established.
2092 */
2093 retval = SCTP_IERROR_NOMEM;
2094 break;
2095 }
2096 }
2097
2098 if (!sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM,
2099 ntohs(param.p->length)))
2100 sctp_addto_chunk(*errp, ntohs(param.p->length),
2101 param.v);
2102 break;
2103 default:
2104 break;
2105 }
2106
2107 return retval;
2108}
2109
2110/* Verify variable length parameters
2111 * Return values:
2112 * SCTP_IERROR_ABORT - trigger an ABORT
2113 * SCTP_IERROR_NOMEM - out of memory (abort)
2114 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR
2115 * SCTP_IERROR_NO_ERROR - continue with the chunk
2116 */
2117static enum sctp_ierror sctp_verify_param(struct net *net,
2118 const struct sctp_endpoint *ep,
2119 const struct sctp_association *asoc,
2120 union sctp_params param,
2121 enum sctp_cid cid,
2122 struct sctp_chunk *chunk,
2123 struct sctp_chunk **err_chunk)
2124{
2125 struct sctp_hmac_algo_param *hmacs;
2126 int retval = SCTP_IERROR_NO_ERROR;
2127 __u16 n_elt, id = 0;
2128 int i;
2129
2130 /* FIXME - This routine is not looking at each parameter per the
2131 * chunk type, i.e., unrecognized parameters should be further
2132 * identified based on the chunk id.
2133 */
2134
2135 switch (param.p->type) {
2136 case SCTP_PARAM_IPV4_ADDRESS:
2137 case SCTP_PARAM_IPV6_ADDRESS:
2138 case SCTP_PARAM_COOKIE_PRESERVATIVE:
2139 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
2140 case SCTP_PARAM_STATE_COOKIE:
2141 case SCTP_PARAM_HEARTBEAT_INFO:
2142 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
2143 case SCTP_PARAM_ECN_CAPABLE:
2144 case SCTP_PARAM_ADAPTATION_LAYER_IND:
2145 break;
2146
2147 case SCTP_PARAM_SUPPORTED_EXT:
2148 if (!sctp_verify_ext_param(net, ep, param))
2149 return SCTP_IERROR_ABORT;
2150 break;
2151
2152 case SCTP_PARAM_SET_PRIMARY:
2153 if (ep->asconf_enable)
2154 break;
2155 goto unhandled;
2156
2157 case SCTP_PARAM_HOST_NAME_ADDRESS:
2158 /* Tell the peer, we won't support this param. */
2159 sctp_process_hn_param(asoc, param, chunk, err_chunk);
2160 retval = SCTP_IERROR_ABORT;
2161 break;
2162
2163 case SCTP_PARAM_FWD_TSN_SUPPORT:
2164 if (ep->prsctp_enable)
2165 break;
2166 goto unhandled;
2167
2168 case SCTP_PARAM_RANDOM:
2169 if (!ep->auth_enable)
2170 goto unhandled;
2171
2172 /* SCTP-AUTH: Secion 6.1
2173 * If the random number is not 32 byte long the association
2174 * MUST be aborted. The ABORT chunk SHOULD contain the error
2175 * cause 'Protocol Violation'.
2176 */
2177 if (SCTP_AUTH_RANDOM_LENGTH != ntohs(param.p->length) -
2178 sizeof(struct sctp_paramhdr)) {
2179 sctp_process_inv_paramlength(asoc, param.p,
2180 chunk, err_chunk);
2181 retval = SCTP_IERROR_ABORT;
2182 }
2183 break;
2184
2185 case SCTP_PARAM_CHUNKS:
2186 if (!ep->auth_enable)
2187 goto unhandled;
2188
2189 /* SCTP-AUTH: Section 3.2
2190 * The CHUNKS parameter MUST be included once in the INIT or
2191 * INIT-ACK chunk if the sender wants to receive authenticated
2192 * chunks. Its maximum length is 260 bytes.
2193 */
2194 if (260 < ntohs(param.p->length)) {
2195 sctp_process_inv_paramlength(asoc, param.p,
2196 chunk, err_chunk);
2197 retval = SCTP_IERROR_ABORT;
2198 }
2199 break;
2200
2201 case SCTP_PARAM_HMAC_ALGO:
2202 if (!ep->auth_enable)
2203 goto unhandled;
2204
2205 hmacs = (struct sctp_hmac_algo_param *)param.p;
2206 n_elt = (ntohs(param.p->length) -
2207 sizeof(struct sctp_paramhdr)) >> 1;
2208
2209 /* SCTP-AUTH: Section 6.1
2210 * The HMAC algorithm based on SHA-1 MUST be supported and
2211 * included in the HMAC-ALGO parameter.
2212 */
2213 for (i = 0; i < n_elt; i++) {
2214 id = ntohs(hmacs->hmac_ids[i]);
2215
2216 if (id == SCTP_AUTH_HMAC_ID_SHA1)
2217 break;
2218 }
2219
2220 if (id != SCTP_AUTH_HMAC_ID_SHA1) {
2221 sctp_process_inv_paramlength(asoc, param.p, chunk,
2222 err_chunk);
2223 retval = SCTP_IERROR_ABORT;
2224 }
2225 break;
2226unhandled:
2227 default:
2228 pr_debug("%s: unrecognized param:%d for chunk:%d\n",
2229 __func__, ntohs(param.p->type), cid);
2230
2231 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk);
2232 break;
2233 }
2234 return retval;
2235}
2236
2237/* Verify the INIT packet before we process it. */
2238int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
2239 const struct sctp_association *asoc, enum sctp_cid cid,
2240 struct sctp_init_chunk *peer_init,
2241 struct sctp_chunk *chunk, struct sctp_chunk **errp)
2242{
2243 union sctp_params param;
2244 bool has_cookie = false;
2245 int result;
2246
2247 /* Check for missing mandatory parameters. Note: Initial TSN is
2248 * also mandatory, but is not checked here since the valid range
2249 * is 0..2**32-1. RFC4960, section 3.3.3.
2250 */
2251 if (peer_init->init_hdr.num_outbound_streams == 0 ||
2252 peer_init->init_hdr.num_inbound_streams == 0 ||
2253 peer_init->init_hdr.init_tag == 0 ||
2254 ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW)
2255 return sctp_process_inv_mandatory(asoc, chunk, errp);
2256
2257 sctp_walk_params(param, peer_init, init_hdr.params) {
2258 if (param.p->type == SCTP_PARAM_STATE_COOKIE)
2259 has_cookie = true;
2260 }
2261
2262 /* There is a possibility that a parameter length was bad and
2263 * in that case we would have stoped walking the parameters.
2264 * The current param.p would point at the bad one.
2265 * Current consensus on the mailing list is to generate a PROTOCOL
2266 * VIOLATION error. We build the ERROR chunk here and let the normal
2267 * error handling code build and send the packet.
2268 */
2269 if (param.v != (void *)chunk->chunk_end)
2270 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp);
2271
2272 /* The only missing mandatory param possible today is
2273 * the state cookie for an INIT-ACK chunk.
2274 */
2275 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie)
2276 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE,
2277 chunk, errp);
2278
2279 /* Verify all the variable length parameters */
2280 sctp_walk_params(param, peer_init, init_hdr.params) {
2281 result = sctp_verify_param(net, ep, asoc, param, cid,
2282 chunk, errp);
2283 switch (result) {
2284 case SCTP_IERROR_ABORT:
2285 case SCTP_IERROR_NOMEM:
2286 return 0;
2287 case SCTP_IERROR_ERROR:
2288 return 1;
2289 case SCTP_IERROR_NO_ERROR:
2290 default:
2291 break;
2292 }
2293
2294 } /* for (loop through all parameters) */
2295
2296 return 1;
2297}
2298
2299/* Unpack the parameters in an INIT packet into an association.
2300 * Returns 0 on failure, else success.
2301 * FIXME: This is an association method.
2302 */
2303int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk,
2304 const union sctp_addr *peer_addr,
2305 struct sctp_init_chunk *peer_init, gfp_t gfp)
2306{
2307 struct sctp_transport *transport;
2308 struct list_head *pos, *temp;
2309 union sctp_params param;
2310 union sctp_addr addr;
2311 struct sctp_af *af;
2312 int src_match = 0;
2313
2314 /* We must include the address that the INIT packet came from.
2315 * This is the only address that matters for an INIT packet.
2316 * When processing a COOKIE ECHO, we retrieve the from address
2317 * of the INIT from the cookie.
2318 */
2319
2320 /* This implementation defaults to making the first transport
2321 * added as the primary transport. The source address seems to
2322 * be a a better choice than any of the embedded addresses.
2323 */
2324 if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE))
2325 goto nomem;
2326
2327 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr))
2328 src_match = 1;
2329
2330 /* Process the initialization parameters. */
2331 sctp_walk_params(param, peer_init, init_hdr.params) {
2332 if (!src_match && (param.p->type == SCTP_PARAM_IPV4_ADDRESS ||
2333 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) {
2334 af = sctp_get_af_specific(param_type2af(param.p->type));
2335 af->from_addr_param(&addr, param.addr,
2336 chunk->sctp_hdr->source, 0);
2337 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr))
2338 src_match = 1;
2339 }
2340
2341 if (!sctp_process_param(asoc, param, peer_addr, gfp))
2342 goto clean_up;
2343 }
2344
2345 /* source address of chunk may not match any valid address */
2346 if (!src_match)
2347 goto clean_up;
2348
2349 /* AUTH: After processing the parameters, make sure that we
2350 * have all the required info to potentially do authentications.
2351 */
2352 if (asoc->peer.auth_capable && (!asoc->peer.peer_random ||
2353 !asoc->peer.peer_hmacs))
2354 asoc->peer.auth_capable = 0;
2355
2356 /* In a non-backward compatible mode, if the peer claims
2357 * support for ADD-IP but not AUTH, the ADD-IP spec states
2358 * that we MUST ABORT the association. Section 6. The section
2359 * also give us an option to silently ignore the packet, which
2360 * is what we'll do here.
2361 */
2362 if (!asoc->base.net->sctp.addip_noauth &&
2363 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) {
2364 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP |
2365 SCTP_PARAM_DEL_IP |
2366 SCTP_PARAM_SET_PRIMARY);
2367 asoc->peer.asconf_capable = 0;
2368 goto clean_up;
2369 }
2370
2371 /* Walk list of transports, removing transports in the UNKNOWN state. */
2372 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
2373 transport = list_entry(pos, struct sctp_transport, transports);
2374 if (transport->state == SCTP_UNKNOWN) {
2375 sctp_assoc_rm_peer(asoc, transport);
2376 }
2377 }
2378
2379 /* The fixed INIT headers are always in network byte
2380 * order.
2381 */
2382 asoc->peer.i.init_tag =
2383 ntohl(peer_init->init_hdr.init_tag);
2384 asoc->peer.i.a_rwnd =
2385 ntohl(peer_init->init_hdr.a_rwnd);
2386 asoc->peer.i.num_outbound_streams =
2387 ntohs(peer_init->init_hdr.num_outbound_streams);
2388 asoc->peer.i.num_inbound_streams =
2389 ntohs(peer_init->init_hdr.num_inbound_streams);
2390 asoc->peer.i.initial_tsn =
2391 ntohl(peer_init->init_hdr.initial_tsn);
2392
2393 asoc->strreset_inseq = asoc->peer.i.initial_tsn;
2394
2395 /* Apply the upper bounds for output streams based on peer's
2396 * number of inbound streams.
2397 */
2398 if (asoc->c.sinit_num_ostreams >
2399 ntohs(peer_init->init_hdr.num_inbound_streams)) {
2400 asoc->c.sinit_num_ostreams =
2401 ntohs(peer_init->init_hdr.num_inbound_streams);
2402 }
2403
2404 if (asoc->c.sinit_max_instreams >
2405 ntohs(peer_init->init_hdr.num_outbound_streams)) {
2406 asoc->c.sinit_max_instreams =
2407 ntohs(peer_init->init_hdr.num_outbound_streams);
2408 }
2409
2410 /* Copy Initiation tag from INIT to VT_peer in cookie. */
2411 asoc->c.peer_vtag = asoc->peer.i.init_tag;
2412
2413 /* Peer Rwnd : Current calculated value of the peer's rwnd. */
2414 asoc->peer.rwnd = asoc->peer.i.a_rwnd;
2415
2416 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily
2417 * high (for example, implementations MAY use the size of the receiver
2418 * advertised window).
2419 */
2420 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
2421 transports) {
2422 transport->ssthresh = asoc->peer.i.a_rwnd;
2423 }
2424
2425 /* Set up the TSN tracking pieces. */
2426 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
2427 asoc->peer.i.initial_tsn, gfp))
2428 goto clean_up;
2429
2430 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
2431 *
2432 * The stream sequence number in all the streams shall start
2433 * from 0 when the association is established. Also, when the
2434 * stream sequence number reaches the value 65535 the next
2435 * stream sequence number shall be set to 0.
2436 */
2437
2438 if (sctp_stream_init(&asoc->stream, asoc->c.sinit_num_ostreams,
2439 asoc->c.sinit_max_instreams, gfp))
2440 goto clean_up;
2441
2442 /* Update frag_point when stream_interleave may get changed. */
2443 sctp_assoc_update_frag_point(asoc);
2444
2445 if (!asoc->temp && sctp_assoc_set_id(asoc, gfp))
2446 goto clean_up;
2447
2448 /* ADDIP Section 4.1 ASCONF Chunk Procedures
2449 *
2450 * When an endpoint has an ASCONF signaled change to be sent to the
2451 * remote endpoint it should do the following:
2452 * ...
2453 * A2) A serial number should be assigned to the Chunk. The serial
2454 * number should be a monotonically increasing number. All serial
2455 * numbers are defined to be initialized at the start of the
2456 * association to the same value as the Initial TSN.
2457 */
2458 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1;
2459 return 1;
2460
2461clean_up:
2462 /* Release the transport structures. */
2463 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
2464 transport = list_entry(pos, struct sctp_transport, transports);
2465 if (transport->state != SCTP_ACTIVE)
2466 sctp_assoc_rm_peer(asoc, transport);
2467 }
2468
2469nomem:
2470 return 0;
2471}
2472
2473
2474/* Update asoc with the option described in param.
2475 *
2476 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT
2477 *
2478 * asoc is the association to update.
2479 * param is the variable length parameter to use for update.
2480 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO.
2481 * If the current packet is an INIT we want to minimize the amount of
2482 * work we do. In particular, we should not build transport
2483 * structures for the addresses.
2484 */
2485static int sctp_process_param(struct sctp_association *asoc,
2486 union sctp_params param,
2487 const union sctp_addr *peer_addr,
2488 gfp_t gfp)
2489{
2490 struct sctp_endpoint *ep = asoc->ep;
2491 union sctp_addr_param *addr_param;
2492 struct net *net = asoc->base.net;
2493 struct sctp_transport *t;
2494 enum sctp_scope scope;
2495 union sctp_addr addr;
2496 struct sctp_af *af;
2497 int retval = 1, i;
2498 u32 stale;
2499 __u16 sat;
2500
2501 /* We maintain all INIT parameters in network byte order all the
2502 * time. This allows us to not worry about whether the parameters
2503 * came from a fresh INIT, and INIT ACK, or were stored in a cookie.
2504 */
2505 switch (param.p->type) {
2506 case SCTP_PARAM_IPV6_ADDRESS:
2507 if (PF_INET6 != asoc->base.sk->sk_family)
2508 break;
2509 goto do_addr_param;
2510
2511 case SCTP_PARAM_IPV4_ADDRESS:
2512 /* v4 addresses are not allowed on v6-only socket */
2513 if (ipv6_only_sock(asoc->base.sk))
2514 break;
2515do_addr_param:
2516 af = sctp_get_af_specific(param_type2af(param.p->type));
2517 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0);
2518 scope = sctp_scope(peer_addr);
2519 if (sctp_in_scope(net, &addr, scope))
2520 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED))
2521 return 0;
2522 break;
2523
2524 case SCTP_PARAM_COOKIE_PRESERVATIVE:
2525 if (!net->sctp.cookie_preserve_enable)
2526 break;
2527
2528 stale = ntohl(param.life->lifespan_increment);
2529
2530 /* Suggested Cookie Life span increment's unit is msec,
2531 * (1/1000sec).
2532 */
2533 asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale);
2534 break;
2535
2536 case SCTP_PARAM_HOST_NAME_ADDRESS:
2537 pr_debug("%s: unimplemented SCTP_HOST_NAME_ADDRESS\n", __func__);
2538 break;
2539
2540 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
2541 /* Turn off the default values first so we'll know which
2542 * ones are really set by the peer.
2543 */
2544 asoc->peer.ipv4_address = 0;
2545 asoc->peer.ipv6_address = 0;
2546
2547 /* Assume that peer supports the address family
2548 * by which it sends a packet.
2549 */
2550 if (peer_addr->sa.sa_family == AF_INET6)
2551 asoc->peer.ipv6_address = 1;
2552 else if (peer_addr->sa.sa_family == AF_INET)
2553 asoc->peer.ipv4_address = 1;
2554
2555 /* Cycle through address types; avoid divide by 0. */
2556 sat = ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
2557 if (sat)
2558 sat /= sizeof(__u16);
2559
2560 for (i = 0; i < sat; ++i) {
2561 switch (param.sat->types[i]) {
2562 case SCTP_PARAM_IPV4_ADDRESS:
2563 asoc->peer.ipv4_address = 1;
2564 break;
2565
2566 case SCTP_PARAM_IPV6_ADDRESS:
2567 if (PF_INET6 == asoc->base.sk->sk_family)
2568 asoc->peer.ipv6_address = 1;
2569 break;
2570
2571 case SCTP_PARAM_HOST_NAME_ADDRESS:
2572 asoc->peer.hostname_address = 1;
2573 break;
2574
2575 default: /* Just ignore anything else. */
2576 break;
2577 }
2578 }
2579 break;
2580
2581 case SCTP_PARAM_STATE_COOKIE:
2582 asoc->peer.cookie_len =
2583 ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
2584 kfree(asoc->peer.cookie);
2585 asoc->peer.cookie = kmemdup(param.cookie->body, asoc->peer.cookie_len, gfp);
2586 if (!asoc->peer.cookie)
2587 retval = 0;
2588 break;
2589
2590 case SCTP_PARAM_HEARTBEAT_INFO:
2591 /* Would be odd to receive, but it causes no problems. */
2592 break;
2593
2594 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
2595 /* Rejected during verify stage. */
2596 break;
2597
2598 case SCTP_PARAM_ECN_CAPABLE:
2599 if (asoc->ep->ecn_enable) {
2600 asoc->peer.ecn_capable = 1;
2601 break;
2602 }
2603 /* Fall Through */
2604 goto fall_through;
2605
2606
2607 case SCTP_PARAM_ADAPTATION_LAYER_IND:
2608 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind);
2609 break;
2610
2611 case SCTP_PARAM_SET_PRIMARY:
2612 if (!ep->asconf_enable)
2613 goto fall_through;
2614
2615 addr_param = param.v + sizeof(struct sctp_addip_param);
2616
2617 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
2618 if (af == NULL)
2619 break;
2620
2621 af->from_addr_param(&addr, addr_param,
2622 htons(asoc->peer.port), 0);
2623
2624 /* if the address is invalid, we can't process it.
2625 * XXX: see spec for what to do.
2626 */
2627 if (!af->addr_valid(&addr, NULL, NULL))
2628 break;
2629
2630 t = sctp_assoc_lookup_paddr(asoc, &addr);
2631 if (!t)
2632 break;
2633
2634 sctp_assoc_set_primary(asoc, t);
2635 break;
2636
2637 case SCTP_PARAM_SUPPORTED_EXT:
2638 sctp_process_ext_param(asoc, param);
2639 break;
2640
2641 case SCTP_PARAM_FWD_TSN_SUPPORT:
2642 if (asoc->ep->prsctp_enable) {
2643 asoc->peer.prsctp_capable = 1;
2644 break;
2645 }
2646 /* Fall Through */
2647 goto fall_through;
2648
2649 case SCTP_PARAM_RANDOM:
2650 if (!ep->auth_enable)
2651 goto fall_through;
2652
2653 /* Save peer's random parameter */
2654 kfree(asoc->peer.peer_random);
2655 asoc->peer.peer_random = kmemdup(param.p,
2656 ntohs(param.p->length), gfp);
2657 if (!asoc->peer.peer_random) {
2658 retval = 0;
2659 break;
2660 }
2661 break;
2662
2663 case SCTP_PARAM_HMAC_ALGO:
2664 if (!ep->auth_enable)
2665 goto fall_through;
2666
2667 /* Save peer's HMAC list */
2668 kfree(asoc->peer.peer_hmacs);
2669 asoc->peer.peer_hmacs = kmemdup(param.p,
2670 ntohs(param.p->length), gfp);
2671 if (!asoc->peer.peer_hmacs) {
2672 retval = 0;
2673 break;
2674 }
2675
2676 /* Set the default HMAC the peer requested*/
2677 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo);
2678 break;
2679
2680 case SCTP_PARAM_CHUNKS:
2681 if (!ep->auth_enable)
2682 goto fall_through;
2683
2684 kfree(asoc->peer.peer_chunks);
2685 asoc->peer.peer_chunks = kmemdup(param.p,
2686 ntohs(param.p->length), gfp);
2687 if (!asoc->peer.peer_chunks)
2688 retval = 0;
2689 break;
2690fall_through:
2691 default:
2692 /* Any unrecognized parameters should have been caught
2693 * and handled by sctp_verify_param() which should be
2694 * called prior to this routine. Simply log the error
2695 * here.
2696 */
2697 pr_debug("%s: ignoring param:%d for association:%p.\n",
2698 __func__, ntohs(param.p->type), asoc);
2699 break;
2700 }
2701
2702 return retval;
2703}
2704
2705/* Select a new verification tag. */
2706__u32 sctp_generate_tag(const struct sctp_endpoint *ep)
2707{
2708 /* I believe that this random number generator complies with RFC1750.
2709 * A tag of 0 is reserved for special cases (e.g. INIT).
2710 */
2711 __u32 x;
2712
2713 do {
2714 get_random_bytes(&x, sizeof(__u32));
2715 } while (x == 0);
2716
2717 return x;
2718}
2719
2720/* Select an initial TSN to send during startup. */
2721__u32 sctp_generate_tsn(const struct sctp_endpoint *ep)
2722{
2723 __u32 retval;
2724
2725 get_random_bytes(&retval, sizeof(__u32));
2726 return retval;
2727}
2728
2729/*
2730 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF)
2731 * 0 1 2 3
2732 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2733 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2734 * | Type = 0xC1 | Chunk Flags | Chunk Length |
2735 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2736 * | Serial Number |
2737 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2738 * | Address Parameter |
2739 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2740 * | ASCONF Parameter #1 |
2741 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2742 * \ \
2743 * / .... /
2744 * \ \
2745 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2746 * | ASCONF Parameter #N |
2747 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2748 *
2749 * Address Parameter and other parameter will not be wrapped in this function
2750 */
2751static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc,
2752 union sctp_addr *addr,
2753 int vparam_len)
2754{
2755 struct sctp_addiphdr asconf;
2756 struct sctp_chunk *retval;
2757 int length = sizeof(asconf) + vparam_len;
2758 union sctp_addr_param addrparam;
2759 int addrlen;
2760 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
2761
2762 addrlen = af->to_addr_param(addr, &addrparam);
2763 if (!addrlen)
2764 return NULL;
2765 length += addrlen;
2766
2767 /* Create the chunk. */
2768 retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length,
2769 GFP_ATOMIC);
2770 if (!retval)
2771 return NULL;
2772
2773 asconf.serial = htonl(asoc->addip_serial++);
2774
2775 retval->subh.addip_hdr =
2776 sctp_addto_chunk(retval, sizeof(asconf), &asconf);
2777 retval->param_hdr.v =
2778 sctp_addto_chunk(retval, addrlen, &addrparam);
2779
2780 return retval;
2781}
2782
2783/* ADDIP
2784 * 3.2.1 Add IP Address
2785 * 0 1 2 3
2786 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2787 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2788 * | Type = 0xC001 | Length = Variable |
2789 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2790 * | ASCONF-Request Correlation ID |
2791 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2792 * | Address Parameter |
2793 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2794 *
2795 * 3.2.2 Delete IP Address
2796 * 0 1 2 3
2797 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2798 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2799 * | Type = 0xC002 | Length = Variable |
2800 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2801 * | ASCONF-Request Correlation ID |
2802 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2803 * | Address Parameter |
2804 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2805 *
2806 */
2807struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc,
2808 union sctp_addr *laddr,
2809 struct sockaddr *addrs,
2810 int addrcnt, __be16 flags)
2811{
2812 union sctp_addr_param addr_param;
2813 struct sctp_addip_param param;
2814 int paramlen = sizeof(param);
2815 struct sctp_chunk *retval;
2816 int addr_param_len = 0;
2817 union sctp_addr *addr;
2818 int totallen = 0, i;
2819 int del_pickup = 0;
2820 struct sctp_af *af;
2821 void *addr_buf;
2822
2823 /* Get total length of all the address parameters. */
2824 addr_buf = addrs;
2825 for (i = 0; i < addrcnt; i++) {
2826 addr = addr_buf;
2827 af = sctp_get_af_specific(addr->v4.sin_family);
2828 addr_param_len = af->to_addr_param(addr, &addr_param);
2829
2830 totallen += paramlen;
2831 totallen += addr_param_len;
2832
2833 addr_buf += af->sockaddr_len;
2834 if (asoc->asconf_addr_del_pending && !del_pickup) {
2835 /* reuse the parameter length from the same scope one */
2836 totallen += paramlen;
2837 totallen += addr_param_len;
2838 del_pickup = 1;
2839
2840 pr_debug("%s: picked same-scope del_pending addr, "
2841 "totallen for all addresses is %d\n",
2842 __func__, totallen);
2843 }
2844 }
2845
2846 /* Create an asconf chunk with the required length. */
2847 retval = sctp_make_asconf(asoc, laddr, totallen);
2848 if (!retval)
2849 return NULL;
2850
2851 /* Add the address parameters to the asconf chunk. */
2852 addr_buf = addrs;
2853 for (i = 0; i < addrcnt; i++) {
2854 addr = addr_buf;
2855 af = sctp_get_af_specific(addr->v4.sin_family);
2856 addr_param_len = af->to_addr_param(addr, &addr_param);
2857 param.param_hdr.type = flags;
2858 param.param_hdr.length = htons(paramlen + addr_param_len);
2859 param.crr_id = htonl(i);
2860
2861 sctp_addto_chunk(retval, paramlen, ¶m);
2862 sctp_addto_chunk(retval, addr_param_len, &addr_param);
2863
2864 addr_buf += af->sockaddr_len;
2865 }
2866 if (flags == SCTP_PARAM_ADD_IP && del_pickup) {
2867 addr = asoc->asconf_addr_del_pending;
2868 af = sctp_get_af_specific(addr->v4.sin_family);
2869 addr_param_len = af->to_addr_param(addr, &addr_param);
2870 param.param_hdr.type = SCTP_PARAM_DEL_IP;
2871 param.param_hdr.length = htons(paramlen + addr_param_len);
2872 param.crr_id = htonl(i);
2873
2874 sctp_addto_chunk(retval, paramlen, ¶m);
2875 sctp_addto_chunk(retval, addr_param_len, &addr_param);
2876 }
2877 return retval;
2878}
2879
2880/* ADDIP
2881 * 3.2.4 Set Primary IP Address
2882 * 0 1 2 3
2883 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2884 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2885 * | Type =0xC004 | Length = Variable |
2886 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2887 * | ASCONF-Request Correlation ID |
2888 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2889 * | Address Parameter |
2890 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2891 *
2892 * Create an ASCONF chunk with Set Primary IP address parameter.
2893 */
2894struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
2895 union sctp_addr *addr)
2896{
2897 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
2898 union sctp_addr_param addrparam;
2899 struct sctp_addip_param param;
2900 struct sctp_chunk *retval;
2901 int len = sizeof(param);
2902 int addrlen;
2903
2904 addrlen = af->to_addr_param(addr, &addrparam);
2905 if (!addrlen)
2906 return NULL;
2907 len += addrlen;
2908
2909 /* Create the chunk and make asconf header. */
2910 retval = sctp_make_asconf(asoc, addr, len);
2911 if (!retval)
2912 return NULL;
2913
2914 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY;
2915 param.param_hdr.length = htons(len);
2916 param.crr_id = 0;
2917
2918 sctp_addto_chunk(retval, sizeof(param), ¶m);
2919 sctp_addto_chunk(retval, addrlen, &addrparam);
2920
2921 return retval;
2922}
2923
2924/* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK)
2925 * 0 1 2 3
2926 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2927 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2928 * | Type = 0x80 | Chunk Flags | Chunk Length |
2929 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2930 * | Serial Number |
2931 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2932 * | ASCONF Parameter Response#1 |
2933 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2934 * \ \
2935 * / .... /
2936 * \ \
2937 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2938 * | ASCONF Parameter Response#N |
2939 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2940 *
2941 * Create an ASCONF_ACK chunk with enough space for the parameter responses.
2942 */
2943static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc,
2944 __u32 serial, int vparam_len)
2945{
2946 struct sctp_addiphdr asconf;
2947 struct sctp_chunk *retval;
2948 int length = sizeof(asconf) + vparam_len;
2949
2950 /* Create the chunk. */
2951 retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length,
2952 GFP_ATOMIC);
2953 if (!retval)
2954 return NULL;
2955
2956 asconf.serial = htonl(serial);
2957
2958 retval->subh.addip_hdr =
2959 sctp_addto_chunk(retval, sizeof(asconf), &asconf);
2960
2961 return retval;
2962}
2963
2964/* Add response parameters to an ASCONF_ACK chunk. */
2965static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id,
2966 __be16 err_code,
2967 struct sctp_addip_param *asconf_param)
2968{
2969 struct sctp_addip_param ack_param;
2970 struct sctp_errhdr err_param;
2971 int asconf_param_len = 0;
2972 int err_param_len = 0;
2973 __be16 response_type;
2974
2975 if (SCTP_ERROR_NO_ERROR == err_code) {
2976 response_type = SCTP_PARAM_SUCCESS_REPORT;
2977 } else {
2978 response_type = SCTP_PARAM_ERR_CAUSE;
2979 err_param_len = sizeof(err_param);
2980 if (asconf_param)
2981 asconf_param_len =
2982 ntohs(asconf_param->param_hdr.length);
2983 }
2984
2985 /* Add Success Indication or Error Cause Indication parameter. */
2986 ack_param.param_hdr.type = response_type;
2987 ack_param.param_hdr.length = htons(sizeof(ack_param) +
2988 err_param_len +
2989 asconf_param_len);
2990 ack_param.crr_id = crr_id;
2991 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param);
2992
2993 if (SCTP_ERROR_NO_ERROR == err_code)
2994 return;
2995
2996 /* Add Error Cause parameter. */
2997 err_param.cause = err_code;
2998 err_param.length = htons(err_param_len + asconf_param_len);
2999 sctp_addto_chunk(chunk, err_param_len, &err_param);
3000
3001 /* Add the failed TLV copied from ASCONF chunk. */
3002 if (asconf_param)
3003 sctp_addto_chunk(chunk, asconf_param_len, asconf_param);
3004}
3005
3006/* Process a asconf parameter. */
3007static __be16 sctp_process_asconf_param(struct sctp_association *asoc,
3008 struct sctp_chunk *asconf,
3009 struct sctp_addip_param *asconf_param)
3010{
3011 union sctp_addr_param *addr_param;
3012 struct sctp_transport *peer;
3013 union sctp_addr addr;
3014 struct sctp_af *af;
3015
3016 addr_param = (void *)asconf_param + sizeof(*asconf_param);
3017
3018 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP &&
3019 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP &&
3020 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY)
3021 return SCTP_ERROR_UNKNOWN_PARAM;
3022
3023 switch (addr_param->p.type) {
3024 case SCTP_PARAM_IPV6_ADDRESS:
3025 if (!asoc->peer.ipv6_address)
3026 return SCTP_ERROR_DNS_FAILED;
3027 break;
3028 case SCTP_PARAM_IPV4_ADDRESS:
3029 if (!asoc->peer.ipv4_address)
3030 return SCTP_ERROR_DNS_FAILED;
3031 break;
3032 default:
3033 return SCTP_ERROR_DNS_FAILED;
3034 }
3035
3036 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
3037 if (unlikely(!af))
3038 return SCTP_ERROR_DNS_FAILED;
3039
3040 af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0);
3041
3042 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast
3043 * or multicast address.
3044 * (note: wildcard is permitted and requires special handling so
3045 * make sure we check for that)
3046 */
3047 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb))
3048 return SCTP_ERROR_DNS_FAILED;
3049
3050 switch (asconf_param->param_hdr.type) {
3051 case SCTP_PARAM_ADD_IP:
3052 /* Section 4.2.1:
3053 * If the address 0.0.0.0 or ::0 is provided, the source
3054 * address of the packet MUST be added.
3055 */
3056 if (af->is_any(&addr))
3057 memcpy(&addr, &asconf->source, sizeof(addr));
3058
3059 if (security_sctp_bind_connect(asoc->ep->base.sk,
3060 SCTP_PARAM_ADD_IP,
3061 (struct sockaddr *)&addr,
3062 af->sockaddr_len))
3063 return SCTP_ERROR_REQ_REFUSED;
3064
3065 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address
3066 * request and does not have the local resources to add this
3067 * new address to the association, it MUST return an Error
3068 * Cause TLV set to the new error code 'Operation Refused
3069 * Due to Resource Shortage'.
3070 */
3071
3072 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED);
3073 if (!peer)
3074 return SCTP_ERROR_RSRC_LOW;
3075
3076 /* Start the heartbeat timer. */
3077 sctp_transport_reset_hb_timer(peer);
3078 asoc->new_transport = peer;
3079 break;
3080 case SCTP_PARAM_DEL_IP:
3081 /* ADDIP 4.3 D7) If a request is received to delete the
3082 * last remaining IP address of a peer endpoint, the receiver
3083 * MUST send an Error Cause TLV with the error cause set to the
3084 * new error code 'Request to Delete Last Remaining IP Address'.
3085 */
3086 if (asoc->peer.transport_count == 1)
3087 return SCTP_ERROR_DEL_LAST_IP;
3088
3089 /* ADDIP 4.3 D8) If a request is received to delete an IP
3090 * address which is also the source address of the IP packet
3091 * which contained the ASCONF chunk, the receiver MUST reject
3092 * this request. To reject the request the receiver MUST send
3093 * an Error Cause TLV set to the new error code 'Request to
3094 * Delete Source IP Address'
3095 */
3096 if (sctp_cmp_addr_exact(&asconf->source, &addr))
3097 return SCTP_ERROR_DEL_SRC_IP;
3098
3099 /* Section 4.2.2
3100 * If the address 0.0.0.0 or ::0 is provided, all
3101 * addresses of the peer except the source address of the
3102 * packet MUST be deleted.
3103 */
3104 if (af->is_any(&addr)) {
3105 sctp_assoc_set_primary(asoc, asconf->transport);
3106 sctp_assoc_del_nonprimary_peers(asoc,
3107 asconf->transport);
3108 return SCTP_ERROR_NO_ERROR;
3109 }
3110
3111 /* If the address is not part of the association, the
3112 * ASCONF-ACK with Error Cause Indication Parameter
3113 * which including cause of Unresolvable Address should
3114 * be sent.
3115 */
3116 peer = sctp_assoc_lookup_paddr(asoc, &addr);
3117 if (!peer)
3118 return SCTP_ERROR_DNS_FAILED;
3119
3120 sctp_assoc_rm_peer(asoc, peer);
3121 break;
3122 case SCTP_PARAM_SET_PRIMARY:
3123 /* ADDIP Section 4.2.4
3124 * If the address 0.0.0.0 or ::0 is provided, the receiver
3125 * MAY mark the source address of the packet as its
3126 * primary.
3127 */
3128 if (af->is_any(&addr))
3129 memcpy(&addr.v4, sctp_source(asconf), sizeof(addr));
3130
3131 if (security_sctp_bind_connect(asoc->ep->base.sk,
3132 SCTP_PARAM_SET_PRIMARY,
3133 (struct sockaddr *)&addr,
3134 af->sockaddr_len))
3135 return SCTP_ERROR_REQ_REFUSED;
3136
3137 peer = sctp_assoc_lookup_paddr(asoc, &addr);
3138 if (!peer)
3139 return SCTP_ERROR_DNS_FAILED;
3140
3141 sctp_assoc_set_primary(asoc, peer);
3142 break;
3143 }
3144
3145 return SCTP_ERROR_NO_ERROR;
3146}
3147
3148/* Verify the ASCONF packet before we process it. */
3149bool sctp_verify_asconf(const struct sctp_association *asoc,
3150 struct sctp_chunk *chunk, bool addr_param_needed,
3151 struct sctp_paramhdr **errp)
3152{
3153 struct sctp_addip_chunk *addip;
3154 bool addr_param_seen = false;
3155 union sctp_params param;
3156
3157 addip = (struct sctp_addip_chunk *)chunk->chunk_hdr;
3158 sctp_walk_params(param, addip, addip_hdr.params) {
3159 size_t length = ntohs(param.p->length);
3160
3161 *errp = param.p;
3162 switch (param.p->type) {
3163 case SCTP_PARAM_ERR_CAUSE:
3164 break;
3165 case SCTP_PARAM_IPV4_ADDRESS:
3166 if (length != sizeof(struct sctp_ipv4addr_param))
3167 return false;
3168 /* ensure there is only one addr param and it's in the
3169 * beginning of addip_hdr params, or we reject it.
3170 */
3171 if (param.v != addip->addip_hdr.params)
3172 return false;
3173 addr_param_seen = true;
3174 break;
3175 case SCTP_PARAM_IPV6_ADDRESS:
3176 if (length != sizeof(struct sctp_ipv6addr_param))
3177 return false;
3178 if (param.v != addip->addip_hdr.params)
3179 return false;
3180 addr_param_seen = true;
3181 break;
3182 case SCTP_PARAM_ADD_IP:
3183 case SCTP_PARAM_DEL_IP:
3184 case SCTP_PARAM_SET_PRIMARY:
3185 /* In ASCONF chunks, these need to be first. */
3186 if (addr_param_needed && !addr_param_seen)
3187 return false;
3188 length = ntohs(param.addip->param_hdr.length);
3189 if (length < sizeof(struct sctp_addip_param) +
3190 sizeof(**errp))
3191 return false;
3192 break;
3193 case SCTP_PARAM_SUCCESS_REPORT:
3194 case SCTP_PARAM_ADAPTATION_LAYER_IND:
3195 if (length != sizeof(struct sctp_addip_param))
3196 return false;
3197 break;
3198 default:
3199 /* This is unkown to us, reject! */
3200 return false;
3201 }
3202 }
3203
3204 /* Remaining sanity checks. */
3205 if (addr_param_needed && !addr_param_seen)
3206 return false;
3207 if (!addr_param_needed && addr_param_seen)
3208 return false;
3209 if (param.v != chunk->chunk_end)
3210 return false;
3211
3212 return true;
3213}
3214
3215/* Process an incoming ASCONF chunk with the next expected serial no. and
3216 * return an ASCONF_ACK chunk to be sent in response.
3217 */
3218struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
3219 struct sctp_chunk *asconf)
3220{
3221 union sctp_addr_param *addr_param;
3222 struct sctp_addip_chunk *addip;
3223 struct sctp_chunk *asconf_ack;
3224 bool all_param_pass = true;
3225 struct sctp_addiphdr *hdr;
3226 int length = 0, chunk_len;
3227 union sctp_params param;
3228 __be16 err_code;
3229 __u32 serial;
3230
3231 addip = (struct sctp_addip_chunk *)asconf->chunk_hdr;
3232 chunk_len = ntohs(asconf->chunk_hdr->length) -
3233 sizeof(struct sctp_chunkhdr);
3234 hdr = (struct sctp_addiphdr *)asconf->skb->data;
3235 serial = ntohl(hdr->serial);
3236
3237 /* Skip the addiphdr and store a pointer to address parameter. */
3238 length = sizeof(*hdr);
3239 addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
3240 chunk_len -= length;
3241
3242 /* Skip the address parameter and store a pointer to the first
3243 * asconf parameter.
3244 */
3245 length = ntohs(addr_param->p.length);
3246 chunk_len -= length;
3247
3248 /* create an ASCONF_ACK chunk.
3249 * Based on the definitions of parameters, we know that the size of
3250 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF
3251 * parameters.
3252 */
3253 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4);
3254 if (!asconf_ack)
3255 goto done;
3256
3257 /* Process the TLVs contained within the ASCONF chunk. */
3258 sctp_walk_params(param, addip, addip_hdr.params) {
3259 /* Skip preceeding address parameters. */
3260 if (param.p->type == SCTP_PARAM_IPV4_ADDRESS ||
3261 param.p->type == SCTP_PARAM_IPV6_ADDRESS)
3262 continue;
3263
3264 err_code = sctp_process_asconf_param(asoc, asconf,
3265 param.addip);
3266 /* ADDIP 4.1 A7)
3267 * If an error response is received for a TLV parameter,
3268 * all TLVs with no response before the failed TLV are
3269 * considered successful if not reported. All TLVs after
3270 * the failed response are considered unsuccessful unless
3271 * a specific success indication is present for the parameter.
3272 */
3273 if (err_code != SCTP_ERROR_NO_ERROR)
3274 all_param_pass = false;
3275 if (!all_param_pass)
3276 sctp_add_asconf_response(asconf_ack, param.addip->crr_id,
3277 err_code, param.addip);
3278
3279 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add
3280 * an IP address sends an 'Out of Resource' in its response, it
3281 * MUST also fail any subsequent add or delete requests bundled
3282 * in the ASCONF.
3283 */
3284 if (err_code == SCTP_ERROR_RSRC_LOW)
3285 goto done;
3286 }
3287done:
3288 asoc->peer.addip_serial++;
3289
3290 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc
3291 * after freeing the reference to old asconf ack if any.
3292 */
3293 if (asconf_ack) {
3294 sctp_chunk_hold(asconf_ack);
3295 list_add_tail(&asconf_ack->transmitted_list,
3296 &asoc->asconf_ack_list);
3297 }
3298
3299 return asconf_ack;
3300}
3301
3302/* Process a asconf parameter that is successfully acked. */
3303static void sctp_asconf_param_success(struct sctp_association *asoc,
3304 struct sctp_addip_param *asconf_param)
3305{
3306 struct sctp_bind_addr *bp = &asoc->base.bind_addr;
3307 union sctp_addr_param *addr_param;
3308 struct sctp_sockaddr_entry *saddr;
3309 struct sctp_transport *transport;
3310 union sctp_addr addr;
3311 struct sctp_af *af;
3312
3313 addr_param = (void *)asconf_param + sizeof(*asconf_param);
3314
3315 /* We have checked the packet before, so we do not check again. */
3316 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
3317 af->from_addr_param(&addr, addr_param, htons(bp->port), 0);
3318
3319 switch (asconf_param->param_hdr.type) {
3320 case SCTP_PARAM_ADD_IP:
3321 /* This is always done in BH context with a socket lock
3322 * held, so the list can not change.
3323 */
3324 local_bh_disable();
3325 list_for_each_entry(saddr, &bp->address_list, list) {
3326 if (sctp_cmp_addr_exact(&saddr->a, &addr))
3327 saddr->state = SCTP_ADDR_SRC;
3328 }
3329 local_bh_enable();
3330 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
3331 transports) {
3332 sctp_transport_dst_release(transport);
3333 }
3334 break;
3335 case SCTP_PARAM_DEL_IP:
3336 local_bh_disable();
3337 sctp_del_bind_addr(bp, &addr);
3338 if (asoc->asconf_addr_del_pending != NULL &&
3339 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) {
3340 kfree(asoc->asconf_addr_del_pending);
3341 asoc->asconf_addr_del_pending = NULL;
3342 }
3343 local_bh_enable();
3344 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
3345 transports) {
3346 sctp_transport_dst_release(transport);
3347 }
3348 break;
3349 default:
3350 break;
3351 }
3352}
3353
3354/* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk
3355 * for the given asconf parameter. If there is no response for this parameter,
3356 * return the error code based on the third argument 'no_err'.
3357 * ADDIP 4.1
3358 * A7) If an error response is received for a TLV parameter, all TLVs with no
3359 * response before the failed TLV are considered successful if not reported.
3360 * All TLVs after the failed response are considered unsuccessful unless a
3361 * specific success indication is present for the parameter.
3362 */
3363static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack,
3364 struct sctp_addip_param *asconf_param,
3365 int no_err)
3366{
3367 struct sctp_addip_param *asconf_ack_param;
3368 struct sctp_errhdr *err_param;
3369 int asconf_ack_len;
3370 __be16 err_code;
3371 int length;
3372
3373 if (no_err)
3374 err_code = SCTP_ERROR_NO_ERROR;
3375 else
3376 err_code = SCTP_ERROR_REQ_REFUSED;
3377
3378 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) -
3379 sizeof(struct sctp_chunkhdr);
3380
3381 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to
3382 * the first asconf_ack parameter.
3383 */
3384 length = sizeof(struct sctp_addiphdr);
3385 asconf_ack_param = (struct sctp_addip_param *)(asconf_ack->skb->data +
3386 length);
3387 asconf_ack_len -= length;
3388
3389 while (asconf_ack_len > 0) {
3390 if (asconf_ack_param->crr_id == asconf_param->crr_id) {
3391 switch (asconf_ack_param->param_hdr.type) {
3392 case SCTP_PARAM_SUCCESS_REPORT:
3393 return SCTP_ERROR_NO_ERROR;
3394 case SCTP_PARAM_ERR_CAUSE:
3395 length = sizeof(*asconf_ack_param);
3396 err_param = (void *)asconf_ack_param + length;
3397 asconf_ack_len -= length;
3398 if (asconf_ack_len > 0)
3399 return err_param->cause;
3400 else
3401 return SCTP_ERROR_INV_PARAM;
3402 break;
3403 default:
3404 return SCTP_ERROR_INV_PARAM;
3405 }
3406 }
3407
3408 length = ntohs(asconf_ack_param->param_hdr.length);
3409 asconf_ack_param = (void *)asconf_ack_param + length;
3410 asconf_ack_len -= length;
3411 }
3412
3413 return err_code;
3414}
3415
3416/* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */
3417int sctp_process_asconf_ack(struct sctp_association *asoc,
3418 struct sctp_chunk *asconf_ack)
3419{
3420 struct sctp_chunk *asconf = asoc->addip_last_asconf;
3421 struct sctp_addip_param *asconf_param;
3422 __be16 err_code = SCTP_ERROR_NO_ERROR;
3423 union sctp_addr_param *addr_param;
3424 int asconf_len = asconf->skb->len;
3425 int all_param_pass = 0;
3426 int length = 0;
3427 int no_err = 1;
3428 int retval = 0;
3429
3430 /* Skip the chunkhdr and addiphdr from the last asconf sent and store
3431 * a pointer to address parameter.
3432 */
3433 length = sizeof(struct sctp_addip_chunk);
3434 addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
3435 asconf_len -= length;
3436
3437 /* Skip the address parameter in the last asconf sent and store a
3438 * pointer to the first asconf parameter.
3439 */
3440 length = ntohs(addr_param->p.length);
3441 asconf_param = (void *)addr_param + length;
3442 asconf_len -= length;
3443
3444 /* ADDIP 4.1
3445 * A8) If there is no response(s) to specific TLV parameter(s), and no
3446 * failures are indicated, then all request(s) are considered
3447 * successful.
3448 */
3449 if (asconf_ack->skb->len == sizeof(struct sctp_addiphdr))
3450 all_param_pass = 1;
3451
3452 /* Process the TLVs contained in the last sent ASCONF chunk. */
3453 while (asconf_len > 0) {
3454 if (all_param_pass)
3455 err_code = SCTP_ERROR_NO_ERROR;
3456 else {
3457 err_code = sctp_get_asconf_response(asconf_ack,
3458 asconf_param,
3459 no_err);
3460 if (no_err && (SCTP_ERROR_NO_ERROR != err_code))
3461 no_err = 0;
3462 }
3463
3464 switch (err_code) {
3465 case SCTP_ERROR_NO_ERROR:
3466 sctp_asconf_param_success(asoc, asconf_param);
3467 break;
3468
3469 case SCTP_ERROR_RSRC_LOW:
3470 retval = 1;
3471 break;
3472
3473 case SCTP_ERROR_UNKNOWN_PARAM:
3474 /* Disable sending this type of asconf parameter in
3475 * future.
3476 */
3477 asoc->peer.addip_disabled_mask |=
3478 asconf_param->param_hdr.type;
3479 break;
3480
3481 case SCTP_ERROR_REQ_REFUSED:
3482 case SCTP_ERROR_DEL_LAST_IP:
3483 case SCTP_ERROR_DEL_SRC_IP:
3484 default:
3485 break;
3486 }
3487
3488 /* Skip the processed asconf parameter and move to the next
3489 * one.
3490 */
3491 length = ntohs(asconf_param->param_hdr.length);
3492 asconf_param = (void *)asconf_param + length;
3493 asconf_len -= length;
3494 }
3495
3496 if (no_err && asoc->src_out_of_asoc_ok) {
3497 asoc->src_out_of_asoc_ok = 0;
3498 sctp_transport_immediate_rtx(asoc->peer.primary_path);
3499 }
3500
3501 /* Free the cached last sent asconf chunk. */
3502 list_del_init(&asconf->transmitted_list);
3503 sctp_chunk_free(asconf);
3504 asoc->addip_last_asconf = NULL;
3505
3506 return retval;
3507}
3508
3509/* Make a FWD TSN chunk. */
3510struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
3511 __u32 new_cum_tsn, size_t nstreams,
3512 struct sctp_fwdtsn_skip *skiplist)
3513{
3514 struct sctp_chunk *retval = NULL;
3515 struct sctp_fwdtsn_hdr ftsn_hdr;
3516 struct sctp_fwdtsn_skip skip;
3517 size_t hint;
3518 int i;
3519
3520 hint = (nstreams + 1) * sizeof(__u32);
3521
3522 retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint, GFP_ATOMIC);
3523
3524 if (!retval)
3525 return NULL;
3526
3527 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn);
3528 retval->subh.fwdtsn_hdr =
3529 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr);
3530
3531 for (i = 0; i < nstreams; i++) {
3532 skip.stream = skiplist[i].stream;
3533 skip.ssn = skiplist[i].ssn;
3534 sctp_addto_chunk(retval, sizeof(skip), &skip);
3535 }
3536
3537 return retval;
3538}
3539
3540struct sctp_chunk *sctp_make_ifwdtsn(const struct sctp_association *asoc,
3541 __u32 new_cum_tsn, size_t nstreams,
3542 struct sctp_ifwdtsn_skip *skiplist)
3543{
3544 struct sctp_chunk *retval = NULL;
3545 struct sctp_ifwdtsn_hdr ftsn_hdr;
3546 size_t hint;
3547
3548 hint = (nstreams + 1) * sizeof(__u32);
3549
3550 retval = sctp_make_control(asoc, SCTP_CID_I_FWD_TSN, 0, hint,
3551 GFP_ATOMIC);
3552 if (!retval)
3553 return NULL;
3554
3555 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn);
3556 retval->subh.ifwdtsn_hdr =
3557 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr);
3558
3559 sctp_addto_chunk(retval, nstreams * sizeof(skiplist[0]), skiplist);
3560
3561 return retval;
3562}
3563
3564/* RE-CONFIG 3.1 (RE-CONFIG chunk)
3565 * 0 1 2 3
3566 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
3567 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3568 * | Type = 130 | Chunk Flags | Chunk Length |
3569 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3570 * \ \
3571 * / Re-configuration Parameter /
3572 * \ \
3573 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3574 * \ \
3575 * / Re-configuration Parameter (optional) /
3576 * \ \
3577 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3578 */
3579static struct sctp_chunk *sctp_make_reconf(const struct sctp_association *asoc,
3580 int length)
3581{
3582 struct sctp_reconf_chunk *reconf;
3583 struct sctp_chunk *retval;
3584
3585 retval = sctp_make_control(asoc, SCTP_CID_RECONF, 0, length,
3586 GFP_ATOMIC);
3587 if (!retval)
3588 return NULL;
3589
3590 reconf = (struct sctp_reconf_chunk *)retval->chunk_hdr;
3591 retval->param_hdr.v = reconf->params;
3592
3593 return retval;
3594}
3595
3596/* RE-CONFIG 4.1 (STREAM OUT RESET)
3597 * 0 1 2 3
3598 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
3599 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3600 * | Parameter Type = 13 | Parameter Length = 16 + 2 * N |
3601 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3602 * | Re-configuration Request Sequence Number |
3603 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3604 * | Re-configuration Response Sequence Number |
3605 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3606 * | Sender's Last Assigned TSN |
3607 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3608 * | Stream Number 1 (optional) | Stream Number 2 (optional) |
3609 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3610 * / ...... /
3611 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3612 * | Stream Number N-1 (optional) | Stream Number N (optional) |
3613 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3614 *
3615 * RE-CONFIG 4.2 (STREAM IN RESET)
3616 * 0 1 2 3
3617 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
3618 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3619 * | Parameter Type = 14 | Parameter Length = 8 + 2 * N |
3620 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3621 * | Re-configuration Request Sequence Number |
3622 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3623 * | Stream Number 1 (optional) | Stream Number 2 (optional) |
3624 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3625 * / ...... /
3626 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3627 * | Stream Number N-1 (optional) | Stream Number N (optional) |
3628 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3629 */
3630struct sctp_chunk *sctp_make_strreset_req(
3631 const struct sctp_association *asoc,
3632 __u16 stream_num, __be16 *stream_list,
3633 bool out, bool in)
3634{
3635 __u16 stream_len = stream_num * sizeof(__u16);
3636 struct sctp_strreset_outreq outreq;
3637 struct sctp_strreset_inreq inreq;
3638 struct sctp_chunk *retval;
3639 __u16 outlen, inlen;
3640
3641 outlen = (sizeof(outreq) + stream_len) * out;
3642 inlen = (sizeof(inreq) + stream_len) * in;
3643
3644 retval = sctp_make_reconf(asoc, outlen + inlen);
3645 if (!retval)
3646 return NULL;
3647
3648 if (outlen) {
3649 outreq.param_hdr.type = SCTP_PARAM_RESET_OUT_REQUEST;
3650 outreq.param_hdr.length = htons(outlen);
3651 outreq.request_seq = htonl(asoc->strreset_outseq);
3652 outreq.response_seq = htonl(asoc->strreset_inseq - 1);
3653 outreq.send_reset_at_tsn = htonl(asoc->next_tsn - 1);
3654
3655 sctp_addto_chunk(retval, sizeof(outreq), &outreq);
3656
3657 if (stream_len)
3658 sctp_addto_chunk(retval, stream_len, stream_list);
3659 }
3660
3661 if (inlen) {
3662 inreq.param_hdr.type = SCTP_PARAM_RESET_IN_REQUEST;
3663 inreq.param_hdr.length = htons(inlen);
3664 inreq.request_seq = htonl(asoc->strreset_outseq + out);
3665
3666 sctp_addto_chunk(retval, sizeof(inreq), &inreq);
3667
3668 if (stream_len)
3669 sctp_addto_chunk(retval, stream_len, stream_list);
3670 }
3671
3672 return retval;
3673}
3674
3675/* RE-CONFIG 4.3 (SSN/TSN RESET ALL)
3676 * 0 1 2 3
3677 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
3678 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3679 * | Parameter Type = 15 | Parameter Length = 8 |
3680 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3681 * | Re-configuration Request Sequence Number |
3682 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3683 */
3684struct sctp_chunk *sctp_make_strreset_tsnreq(
3685 const struct sctp_association *asoc)
3686{
3687 struct sctp_strreset_tsnreq tsnreq;
3688 __u16 length = sizeof(tsnreq);
3689 struct sctp_chunk *retval;
3690
3691 retval = sctp_make_reconf(asoc, length);
3692 if (!retval)
3693 return NULL;
3694
3695 tsnreq.param_hdr.type = SCTP_PARAM_RESET_TSN_REQUEST;
3696 tsnreq.param_hdr.length = htons(length);
3697 tsnreq.request_seq = htonl(asoc->strreset_outseq);
3698
3699 sctp_addto_chunk(retval, sizeof(tsnreq), &tsnreq);
3700
3701 return retval;
3702}
3703
3704/* RE-CONFIG 4.5/4.6 (ADD STREAM)
3705 * 0 1 2 3
3706 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
3707 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3708 * | Parameter Type = 17 | Parameter Length = 12 |
3709 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3710 * | Re-configuration Request Sequence Number |
3711 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3712 * | Number of new streams | Reserved |
3713 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3714 */
3715struct sctp_chunk *sctp_make_strreset_addstrm(
3716 const struct sctp_association *asoc,
3717 __u16 out, __u16 in)
3718{
3719 struct sctp_strreset_addstrm addstrm;
3720 __u16 size = sizeof(addstrm);
3721 struct sctp_chunk *retval;
3722
3723 retval = sctp_make_reconf(asoc, (!!out + !!in) * size);
3724 if (!retval)
3725 return NULL;
3726
3727 if (out) {
3728 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_OUT_STREAMS;
3729 addstrm.param_hdr.length = htons(size);
3730 addstrm.number_of_streams = htons(out);
3731 addstrm.request_seq = htonl(asoc->strreset_outseq);
3732 addstrm.reserved = 0;
3733
3734 sctp_addto_chunk(retval, size, &addstrm);
3735 }
3736
3737 if (in) {
3738 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_IN_STREAMS;
3739 addstrm.param_hdr.length = htons(size);
3740 addstrm.number_of_streams = htons(in);
3741 addstrm.request_seq = htonl(asoc->strreset_outseq + !!out);
3742 addstrm.reserved = 0;
3743
3744 sctp_addto_chunk(retval, size, &addstrm);
3745 }
3746
3747 return retval;
3748}
3749
3750/* RE-CONFIG 4.4 (RESP)
3751 * 0 1 2 3
3752 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
3753 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3754 * | Parameter Type = 16 | Parameter Length |
3755 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3756 * | Re-configuration Response Sequence Number |
3757 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3758 * | Result |
3759 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3760 */
3761struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc,
3762 __u32 result, __u32 sn)
3763{
3764 struct sctp_strreset_resp resp;
3765 __u16 length = sizeof(resp);
3766 struct sctp_chunk *retval;
3767
3768 retval = sctp_make_reconf(asoc, length);
3769 if (!retval)
3770 return NULL;
3771
3772 resp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE;
3773 resp.param_hdr.length = htons(length);
3774 resp.response_seq = htonl(sn);
3775 resp.result = htonl(result);
3776
3777 sctp_addto_chunk(retval, sizeof(resp), &resp);
3778
3779 return retval;
3780}
3781
3782/* RE-CONFIG 4.4 OPTIONAL (TSNRESP)
3783 * 0 1 2 3
3784 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
3785 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3786 * | Parameter Type = 16 | Parameter Length |
3787 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3788 * | Re-configuration Response Sequence Number |
3789 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3790 * | Result |
3791 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3792 * | Sender's Next TSN (optional) |
3793 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3794 * | Receiver's Next TSN (optional) |
3795 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3796 */
3797struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc,
3798 __u32 result, __u32 sn,
3799 __u32 sender_tsn,
3800 __u32 receiver_tsn)
3801{
3802 struct sctp_strreset_resptsn tsnresp;
3803 __u16 length = sizeof(tsnresp);
3804 struct sctp_chunk *retval;
3805
3806 retval = sctp_make_reconf(asoc, length);
3807 if (!retval)
3808 return NULL;
3809
3810 tsnresp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE;
3811 tsnresp.param_hdr.length = htons(length);
3812
3813 tsnresp.response_seq = htonl(sn);
3814 tsnresp.result = htonl(result);
3815 tsnresp.senders_next_tsn = htonl(sender_tsn);
3816 tsnresp.receivers_next_tsn = htonl(receiver_tsn);
3817
3818 sctp_addto_chunk(retval, sizeof(tsnresp), &tsnresp);
3819
3820 return retval;
3821}
3822
3823bool sctp_verify_reconf(const struct sctp_association *asoc,
3824 struct sctp_chunk *chunk,
3825 struct sctp_paramhdr **errp)
3826{
3827 struct sctp_reconf_chunk *hdr;
3828 union sctp_params param;
3829 __be16 last = 0;
3830 __u16 cnt = 0;
3831
3832 hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr;
3833 sctp_walk_params(param, hdr, params) {
3834 __u16 length = ntohs(param.p->length);
3835
3836 *errp = param.p;
3837 if (cnt++ > 2)
3838 return false;
3839 switch (param.p->type) {
3840 case SCTP_PARAM_RESET_OUT_REQUEST:
3841 if (length < sizeof(struct sctp_strreset_outreq) ||
3842 (last && last != SCTP_PARAM_RESET_RESPONSE &&
3843 last != SCTP_PARAM_RESET_IN_REQUEST))
3844 return false;
3845 break;
3846 case SCTP_PARAM_RESET_IN_REQUEST:
3847 if (length < sizeof(struct sctp_strreset_inreq) ||
3848 (last && last != SCTP_PARAM_RESET_OUT_REQUEST))
3849 return false;
3850 break;
3851 case SCTP_PARAM_RESET_RESPONSE:
3852 if ((length != sizeof(struct sctp_strreset_resp) &&
3853 length != sizeof(struct sctp_strreset_resptsn)) ||
3854 (last && last != SCTP_PARAM_RESET_RESPONSE &&
3855 last != SCTP_PARAM_RESET_OUT_REQUEST))
3856 return false;
3857 break;
3858 case SCTP_PARAM_RESET_TSN_REQUEST:
3859 if (length !=
3860 sizeof(struct sctp_strreset_tsnreq) || last)
3861 return false;
3862 break;
3863 case SCTP_PARAM_RESET_ADD_IN_STREAMS:
3864 if (length != sizeof(struct sctp_strreset_addstrm) ||
3865 (last && last != SCTP_PARAM_RESET_ADD_OUT_STREAMS))
3866 return false;
3867 break;
3868 case SCTP_PARAM_RESET_ADD_OUT_STREAMS:
3869 if (length != sizeof(struct sctp_strreset_addstrm) ||
3870 (last && last != SCTP_PARAM_RESET_ADD_IN_STREAMS))
3871 return false;
3872 break;
3873 default:
3874 return false;
3875 }
3876
3877 last = param.p->type;
3878 }
3879
3880 return true;
3881}