Loading...
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/* 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 <crypto/hash.h>
49#include <linux/types.h>
50#include <linux/kernel.h>
51#include <linux/ip.h>
52#include <linux/ipv6.h>
53#include <linux/net.h>
54#include <linux/inet.h>
55#include <linux/scatterlist.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,
66 gfp_t gfp);
67static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc,
68 __u8 flags, int paylen, gfp_t gfp);
69static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc,
70 __u8 type, __u8 flags, int paylen,
71 gfp_t gfp);
72static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep,
73 const struct sctp_association *asoc,
74 const struct sctp_chunk *init_chunk,
75 int *cookie_len,
76 const __u8 *raw_addrs, int addrs_len);
77static int sctp_process_param(struct sctp_association *asoc,
78 union sctp_params param,
79 const union sctp_addr *peer_addr,
80 gfp_t gfp);
81static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
82 const void *data);
83static void *sctp_addto_chunk_fixed(struct sctp_chunk *, int len,
84 const void *data);
85
86/* Control chunk destructor */
87static void sctp_control_release_owner(struct sk_buff *skb)
88{
89 /*TODO: do memory release */
90}
91
92static void sctp_control_set_owner_w(struct sctp_chunk *chunk)
93{
94 struct sctp_association *asoc = chunk->asoc;
95 struct sk_buff *skb = chunk->skb;
96
97 /* TODO: properly account for control chunks.
98 * To do it right we'll need:
99 * 1) endpoint if association isn't known.
100 * 2) proper memory accounting.
101 *
102 * For now don't do anything for now.
103 */
104 skb->sk = asoc ? asoc->base.sk : NULL;
105 skb->destructor = sctp_control_release_owner;
106}
107
108/* What was the inbound interface for this chunk? */
109int sctp_chunk_iif(const struct sctp_chunk *chunk)
110{
111 struct sctp_af *af;
112 int iif = 0;
113
114 af = sctp_get_af_specific(ipver2af(ip_hdr(chunk->skb)->version));
115 if (af)
116 iif = af->skb_iif(chunk->skb);
117
118 return iif;
119}
120
121/* RFC 2960 3.3.2 Initiation (INIT) (1)
122 *
123 * Note 2: The ECN capable field is reserved for future use of
124 * Explicit Congestion Notification.
125 */
126static const struct sctp_paramhdr ecap_param = {
127 SCTP_PARAM_ECN_CAPABLE,
128 cpu_to_be16(sizeof(struct sctp_paramhdr)),
129};
130static const struct sctp_paramhdr prsctp_param = {
131 SCTP_PARAM_FWD_TSN_SUPPORT,
132 cpu_to_be16(sizeof(struct sctp_paramhdr)),
133};
134
135/* A helper to initialize an op error inside a
136 * provided chunk, as most cause codes will be embedded inside an
137 * abort chunk.
138 */
139void sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code,
140 size_t paylen)
141{
142 sctp_errhdr_t err;
143 __u16 len;
144
145 /* Cause code constants are now defined in network order. */
146 err.cause = cause_code;
147 len = sizeof(sctp_errhdr_t) + paylen;
148 err.length = htons(len);
149 chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(sctp_errhdr_t), &err);
150}
151
152/* A helper to initialize an op error inside a
153 * provided chunk, as most cause codes will be embedded inside an
154 * abort chunk. Differs from sctp_init_cause in that it won't oops
155 * if there isn't enough space in the op error chunk
156 */
157static int sctp_init_cause_fixed(struct sctp_chunk *chunk, __be16 cause_code,
158 size_t paylen)
159{
160 sctp_errhdr_t err;
161 __u16 len;
162
163 /* Cause code constants are now defined in network order. */
164 err.cause = cause_code;
165 len = sizeof(sctp_errhdr_t) + paylen;
166 err.length = htons(len);
167
168 if (skb_tailroom(chunk->skb) < len)
169 return -ENOSPC;
170 chunk->subh.err_hdr = sctp_addto_chunk_fixed(chunk,
171 sizeof(sctp_errhdr_t),
172 &err);
173 return 0;
174}
175/* 3.3.2 Initiation (INIT) (1)
176 *
177 * This chunk is used to initiate a SCTP association between two
178 * endpoints. The format of the INIT chunk is shown below:
179 *
180 * 0 1 2 3
181 * 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
182 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
183 * | Type = 1 | Chunk Flags | Chunk Length |
184 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
185 * | Initiate Tag |
186 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
187 * | Advertised Receiver Window Credit (a_rwnd) |
188 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
189 * | Number of Outbound Streams | Number of Inbound Streams |
190 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
191 * | Initial TSN |
192 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
193 * \ \
194 * / Optional/Variable-Length Parameters /
195 * \ \
196 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
197 *
198 *
199 * The INIT chunk contains the following parameters. Unless otherwise
200 * noted, each parameter MUST only be included once in the INIT chunk.
201 *
202 * Fixed Parameters Status
203 * ----------------------------------------------
204 * Initiate Tag Mandatory
205 * Advertised Receiver Window Credit Mandatory
206 * Number of Outbound Streams Mandatory
207 * Number of Inbound Streams Mandatory
208 * Initial TSN Mandatory
209 *
210 * Variable Parameters Status Type Value
211 * -------------------------------------------------------------
212 * IPv4 Address (Note 1) Optional 5
213 * IPv6 Address (Note 1) Optional 6
214 * Cookie Preservative Optional 9
215 * Reserved for ECN Capable (Note 2) Optional 32768 (0x8000)
216 * Host Name Address (Note 3) Optional 11
217 * Supported Address Types (Note 4) Optional 12
218 */
219struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc,
220 const struct sctp_bind_addr *bp,
221 gfp_t gfp, int vparam_len)
222{
223 struct net *net = sock_net(asoc->base.sk);
224 struct sctp_endpoint *ep = asoc->ep;
225 sctp_inithdr_t init;
226 union sctp_params addrs;
227 size_t chunksize;
228 struct sctp_chunk *retval = NULL;
229 int num_types, addrs_len = 0;
230 struct sctp_sock *sp;
231 sctp_supported_addrs_param_t sat;
232 __be16 types[2];
233 sctp_adaptation_ind_param_t aiparam;
234 sctp_supported_ext_param_t ext_param;
235 int num_ext = 0;
236 __u8 extensions[3];
237 sctp_paramhdr_t *auth_chunks = NULL,
238 *auth_hmacs = NULL;
239
240 /* RFC 2960 3.3.2 Initiation (INIT) (1)
241 *
242 * Note 1: The INIT chunks can contain multiple addresses that
243 * can be IPv4 and/or IPv6 in any combination.
244 */
245 retval = NULL;
246
247 /* Convert the provided bind address list to raw format. */
248 addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp);
249
250 init.init_tag = htonl(asoc->c.my_vtag);
251 init.a_rwnd = htonl(asoc->rwnd);
252 init.num_outbound_streams = htons(asoc->c.sinit_num_ostreams);
253 init.num_inbound_streams = htons(asoc->c.sinit_max_instreams);
254 init.initial_tsn = htonl(asoc->c.initial_tsn);
255
256 /* How many address types are needed? */
257 sp = sctp_sk(asoc->base.sk);
258 num_types = sp->pf->supported_addrs(sp, types);
259
260 chunksize = sizeof(init) + addrs_len;
261 chunksize += WORD_ROUND(SCTP_SAT_LEN(num_types));
262 chunksize += sizeof(ecap_param);
263
264 if (net->sctp.prsctp_enable)
265 chunksize += sizeof(prsctp_param);
266
267 /* ADDIP: Section 4.2.7:
268 * An implementation supporting this extension [ADDIP] MUST list
269 * the ASCONF,the ASCONF-ACK, and the AUTH chunks in its INIT and
270 * INIT-ACK parameters.
271 */
272 if (net->sctp.addip_enable) {
273 extensions[num_ext] = SCTP_CID_ASCONF;
274 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
275 num_ext += 2;
276 }
277
278 if (sp->adaptation_ind)
279 chunksize += sizeof(aiparam);
280
281 chunksize += vparam_len;
282
283 /* Account for AUTH related parameters */
284 if (ep->auth_enable) {
285 /* Add random parameter length*/
286 chunksize += sizeof(asoc->c.auth_random);
287
288 /* Add HMACS parameter length if any were defined */
289 auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs;
290 if (auth_hmacs->length)
291 chunksize += WORD_ROUND(ntohs(auth_hmacs->length));
292 else
293 auth_hmacs = NULL;
294
295 /* Add CHUNKS parameter length */
296 auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks;
297 if (auth_chunks->length)
298 chunksize += WORD_ROUND(ntohs(auth_chunks->length));
299 else
300 auth_chunks = NULL;
301
302 extensions[num_ext] = SCTP_CID_AUTH;
303 num_ext += 1;
304 }
305
306 /* If we have any extensions to report, account for that */
307 if (num_ext)
308 chunksize += WORD_ROUND(sizeof(sctp_supported_ext_param_t) +
309 num_ext);
310
311 /* RFC 2960 3.3.2 Initiation (INIT) (1)
312 *
313 * Note 3: An INIT chunk MUST NOT contain more than one Host
314 * Name address parameter. Moreover, the sender of the INIT
315 * MUST NOT combine any other address types with the Host Name
316 * address in the INIT. The receiver of INIT MUST ignore any
317 * other address types if the Host Name address parameter is
318 * present in the received INIT chunk.
319 *
320 * PLEASE DO NOT FIXME [This version does not support Host Name.]
321 */
322
323 retval = sctp_make_control(asoc, SCTP_CID_INIT, 0, chunksize, gfp);
324 if (!retval)
325 goto nodata;
326
327 retval->subh.init_hdr =
328 sctp_addto_chunk(retval, sizeof(init), &init);
329 retval->param_hdr.v =
330 sctp_addto_chunk(retval, addrs_len, addrs.v);
331
332 /* RFC 2960 3.3.2 Initiation (INIT) (1)
333 *
334 * Note 4: This parameter, when present, specifies all the
335 * address types the sending endpoint can support. The absence
336 * of this parameter indicates that the sending endpoint can
337 * support any address type.
338 */
339 sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES;
340 sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types));
341 sctp_addto_chunk(retval, sizeof(sat), &sat);
342 sctp_addto_chunk(retval, num_types * sizeof(__u16), &types);
343
344 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
345
346 /* Add the supported extensions parameter. Be nice and add this
347 * fist before addiding the parameters for the extensions themselves
348 */
349 if (num_ext) {
350 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
351 ext_param.param_hdr.length =
352 htons(sizeof(sctp_supported_ext_param_t) + num_ext);
353 sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t),
354 &ext_param);
355 sctp_addto_param(retval, num_ext, extensions);
356 }
357
358 if (net->sctp.prsctp_enable)
359 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
360
361 if (sp->adaptation_ind) {
362 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
363 aiparam.param_hdr.length = htons(sizeof(aiparam));
364 aiparam.adaptation_ind = htonl(sp->adaptation_ind);
365 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
366 }
367
368 /* Add SCTP-AUTH chunks to the parameter list */
369 if (ep->auth_enable) {
370 sctp_addto_chunk(retval, sizeof(asoc->c.auth_random),
371 asoc->c.auth_random);
372 if (auth_hmacs)
373 sctp_addto_chunk(retval, ntohs(auth_hmacs->length),
374 auth_hmacs);
375 if (auth_chunks)
376 sctp_addto_chunk(retval, ntohs(auth_chunks->length),
377 auth_chunks);
378 }
379nodata:
380 kfree(addrs.v);
381 return retval;
382}
383
384struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc,
385 const struct sctp_chunk *chunk,
386 gfp_t gfp, int unkparam_len)
387{
388 sctp_inithdr_t initack;
389 struct sctp_chunk *retval;
390 union sctp_params addrs;
391 struct sctp_sock *sp;
392 int addrs_len;
393 sctp_cookie_param_t *cookie;
394 int cookie_len;
395 size_t chunksize;
396 sctp_adaptation_ind_param_t aiparam;
397 sctp_supported_ext_param_t ext_param;
398 int num_ext = 0;
399 __u8 extensions[3];
400 sctp_paramhdr_t *auth_chunks = NULL,
401 *auth_hmacs = NULL,
402 *auth_random = NULL;
403
404 retval = NULL;
405
406 /* Note: there may be no addresses to embed. */
407 addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp);
408
409 initack.init_tag = htonl(asoc->c.my_vtag);
410 initack.a_rwnd = htonl(asoc->rwnd);
411 initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams);
412 initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams);
413 initack.initial_tsn = htonl(asoc->c.initial_tsn);
414
415 /* FIXME: We really ought to build the cookie right
416 * into the packet instead of allocating more fresh memory.
417 */
418 cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len,
419 addrs.v, addrs_len);
420 if (!cookie)
421 goto nomem_cookie;
422
423 /* Calculate the total size of allocation, include the reserved
424 * space for reporting unknown parameters if it is specified.
425 */
426 sp = sctp_sk(asoc->base.sk);
427 chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len;
428
429 /* Tell peer that we'll do ECN only if peer advertised such cap. */
430 if (asoc->peer.ecn_capable)
431 chunksize += sizeof(ecap_param);
432
433 if (asoc->peer.prsctp_capable)
434 chunksize += sizeof(prsctp_param);
435
436 if (asoc->peer.asconf_capable) {
437 extensions[num_ext] = SCTP_CID_ASCONF;
438 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
439 num_ext += 2;
440 }
441
442 if (sp->adaptation_ind)
443 chunksize += sizeof(aiparam);
444
445 if (asoc->peer.auth_capable) {
446 auth_random = (sctp_paramhdr_t *)asoc->c.auth_random;
447 chunksize += ntohs(auth_random->length);
448
449 auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs;
450 if (auth_hmacs->length)
451 chunksize += WORD_ROUND(ntohs(auth_hmacs->length));
452 else
453 auth_hmacs = NULL;
454
455 auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks;
456 if (auth_chunks->length)
457 chunksize += WORD_ROUND(ntohs(auth_chunks->length));
458 else
459 auth_chunks = NULL;
460
461 extensions[num_ext] = SCTP_CID_AUTH;
462 num_ext += 1;
463 }
464
465 if (num_ext)
466 chunksize += WORD_ROUND(sizeof(sctp_supported_ext_param_t) +
467 num_ext);
468
469 /* Now allocate and fill out the chunk. */
470 retval = sctp_make_control(asoc, SCTP_CID_INIT_ACK, 0, chunksize, gfp);
471 if (!retval)
472 goto nomem_chunk;
473
474 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
475 *
476 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
477 * HEARTBEAT ACK, * etc.) to the same destination transport
478 * address from which it received the DATA or control chunk
479 * to which it is replying.
480 *
481 * [INIT ACK back to where the INIT came from.]
482 */
483 retval->transport = chunk->transport;
484
485 retval->subh.init_hdr =
486 sctp_addto_chunk(retval, sizeof(initack), &initack);
487 retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v);
488 sctp_addto_chunk(retval, cookie_len, cookie);
489 if (asoc->peer.ecn_capable)
490 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
491 if (num_ext) {
492 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
493 ext_param.param_hdr.length =
494 htons(sizeof(sctp_supported_ext_param_t) + num_ext);
495 sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t),
496 &ext_param);
497 sctp_addto_param(retval, num_ext, extensions);
498 }
499 if (asoc->peer.prsctp_capable)
500 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
501
502 if (sp->adaptation_ind) {
503 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
504 aiparam.param_hdr.length = htons(sizeof(aiparam));
505 aiparam.adaptation_ind = htonl(sp->adaptation_ind);
506 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
507 }
508
509 if (asoc->peer.auth_capable) {
510 sctp_addto_chunk(retval, ntohs(auth_random->length),
511 auth_random);
512 if (auth_hmacs)
513 sctp_addto_chunk(retval, ntohs(auth_hmacs->length),
514 auth_hmacs);
515 if (auth_chunks)
516 sctp_addto_chunk(retval, ntohs(auth_chunks->length),
517 auth_chunks);
518 }
519
520 /* We need to remove the const qualifier at this point. */
521 retval->asoc = (struct sctp_association *) asoc;
522
523nomem_chunk:
524 kfree(cookie);
525nomem_cookie:
526 kfree(addrs.v);
527 return retval;
528}
529
530/* 3.3.11 Cookie Echo (COOKIE ECHO) (10):
531 *
532 * This chunk is used only during the initialization of an association.
533 * It is sent by the initiator of an association to its peer to complete
534 * the initialization process. This chunk MUST precede any DATA chunk
535 * sent within the association, but MAY be bundled with one or more DATA
536 * chunks in the same packet.
537 *
538 * 0 1 2 3
539 * 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
540 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
541 * | Type = 10 |Chunk Flags | Length |
542 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
543 * / Cookie /
544 * \ \
545 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
546 *
547 * Chunk Flags: 8 bit
548 *
549 * Set to zero on transmit and ignored on receipt.
550 *
551 * Length: 16 bits (unsigned integer)
552 *
553 * Set to the size of the chunk in bytes, including the 4 bytes of
554 * the chunk header and the size of the Cookie.
555 *
556 * Cookie: variable size
557 *
558 * This field must contain the exact cookie received in the
559 * State Cookie parameter from the previous INIT ACK.
560 *
561 * An implementation SHOULD make the cookie as small as possible
562 * to insure interoperability.
563 */
564struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc,
565 const struct sctp_chunk *chunk)
566{
567 struct sctp_chunk *retval;
568 void *cookie;
569 int cookie_len;
570
571 cookie = asoc->peer.cookie;
572 cookie_len = asoc->peer.cookie_len;
573
574 /* Build a cookie echo chunk. */
575 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ECHO, 0,
576 cookie_len, GFP_ATOMIC);
577 if (!retval)
578 goto nodata;
579 retval->subh.cookie_hdr =
580 sctp_addto_chunk(retval, cookie_len, cookie);
581
582 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
583 *
584 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
585 * HEARTBEAT ACK, * etc.) to the same destination transport
586 * address from which it * received the DATA or control chunk
587 * to which it is replying.
588 *
589 * [COOKIE ECHO back to where the INIT ACK came from.]
590 */
591 if (chunk)
592 retval->transport = chunk->transport;
593
594nodata:
595 return retval;
596}
597
598/* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11):
599 *
600 * This chunk is used only during the initialization of an
601 * association. It is used to acknowledge the receipt of a COOKIE
602 * ECHO chunk. This chunk MUST precede any DATA or SACK chunk sent
603 * within the association, but MAY be bundled with one or more DATA
604 * chunks or SACK chunk in the same SCTP packet.
605 *
606 * 0 1 2 3
607 * 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
608 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
609 * | Type = 11 |Chunk Flags | Length = 4 |
610 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
611 *
612 * Chunk Flags: 8 bits
613 *
614 * Set to zero on transmit and ignored on receipt.
615 */
616struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc,
617 const struct sctp_chunk *chunk)
618{
619 struct sctp_chunk *retval;
620
621 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ACK, 0, 0, GFP_ATOMIC);
622
623 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
624 *
625 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
626 * HEARTBEAT ACK, * etc.) to the same destination transport
627 * address from which it * received the DATA or control chunk
628 * to which it is replying.
629 *
630 * [COOKIE ACK back to where the COOKIE ECHO came from.]
631 */
632 if (retval && chunk)
633 retval->transport = chunk->transport;
634
635 return retval;
636}
637
638/*
639 * Appendix A: Explicit Congestion Notification:
640 * CWR:
641 *
642 * RFC 2481 details a specific bit for a sender to send in the header of
643 * its next outbound TCP segment to indicate to its peer that it has
644 * reduced its congestion window. This is termed the CWR bit. For
645 * SCTP the same indication is made by including the CWR chunk.
646 * This chunk contains one data element, i.e. the TSN number that
647 * was sent in the ECNE chunk. This element represents the lowest
648 * TSN number in the datagram that was originally marked with the
649 * CE bit.
650 *
651 * 0 1 2 3
652 * 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
653 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
654 * | Chunk Type=13 | Flags=00000000| Chunk Length = 8 |
655 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
656 * | Lowest TSN Number |
657 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
658 *
659 * Note: The CWR is considered a Control chunk.
660 */
661struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc,
662 const __u32 lowest_tsn,
663 const struct sctp_chunk *chunk)
664{
665 struct sctp_chunk *retval;
666 sctp_cwrhdr_t cwr;
667
668 cwr.lowest_tsn = htonl(lowest_tsn);
669 retval = sctp_make_control(asoc, SCTP_CID_ECN_CWR, 0,
670 sizeof(sctp_cwrhdr_t), GFP_ATOMIC);
671
672 if (!retval)
673 goto nodata;
674
675 retval->subh.ecn_cwr_hdr =
676 sctp_addto_chunk(retval, sizeof(cwr), &cwr);
677
678 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
679 *
680 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
681 * HEARTBEAT ACK, * etc.) to the same destination transport
682 * address from which it * received the DATA or control chunk
683 * to which it is replying.
684 *
685 * [Report a reduced congestion window back to where the ECNE
686 * came from.]
687 */
688 if (chunk)
689 retval->transport = chunk->transport;
690
691nodata:
692 return retval;
693}
694
695/* Make an ECNE chunk. This is a congestion experienced report. */
696struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc,
697 const __u32 lowest_tsn)
698{
699 struct sctp_chunk *retval;
700 sctp_ecnehdr_t ecne;
701
702 ecne.lowest_tsn = htonl(lowest_tsn);
703 retval = sctp_make_control(asoc, SCTP_CID_ECN_ECNE, 0,
704 sizeof(sctp_ecnehdr_t), GFP_ATOMIC);
705 if (!retval)
706 goto nodata;
707 retval->subh.ecne_hdr =
708 sctp_addto_chunk(retval, sizeof(ecne), &ecne);
709
710nodata:
711 return retval;
712}
713
714/* Make a DATA chunk for the given association from the provided
715 * parameters. However, do not populate the data payload.
716 */
717struct sctp_chunk *sctp_make_datafrag_empty(struct sctp_association *asoc,
718 const struct sctp_sndrcvinfo *sinfo,
719 int data_len, __u8 flags, __u16 ssn,
720 gfp_t gfp)
721{
722 struct sctp_chunk *retval;
723 struct sctp_datahdr dp;
724 int chunk_len;
725
726 /* We assign the TSN as LATE as possible, not here when
727 * creating the chunk.
728 */
729 dp.tsn = 0;
730 dp.stream = htons(sinfo->sinfo_stream);
731 dp.ppid = sinfo->sinfo_ppid;
732
733 /* Set the flags for an unordered send. */
734 if (sinfo->sinfo_flags & SCTP_UNORDERED) {
735 flags |= SCTP_DATA_UNORDERED;
736 dp.ssn = 0;
737 } else
738 dp.ssn = htons(ssn);
739
740 chunk_len = sizeof(dp) + data_len;
741 retval = sctp_make_data(asoc, flags, chunk_len, gfp);
742 if (!retval)
743 goto nodata;
744
745 retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp);
746 memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo));
747
748nodata:
749 return retval;
750}
751
752/* Create a selective ackowledgement (SACK) for the given
753 * association. This reports on which TSN's we've seen to date,
754 * including duplicates and gaps.
755 */
756struct sctp_chunk *sctp_make_sack(const struct sctp_association *asoc)
757{
758 struct sctp_chunk *retval;
759 struct sctp_sackhdr sack;
760 int len;
761 __u32 ctsn;
762 __u16 num_gabs, num_dup_tsns;
763 struct sctp_association *aptr = (struct sctp_association *)asoc;
764 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
765 struct sctp_gap_ack_block gabs[SCTP_MAX_GABS];
766 struct sctp_transport *trans;
767
768 memset(gabs, 0, sizeof(gabs));
769 ctsn = sctp_tsnmap_get_ctsn(map);
770
771 pr_debug("%s: sackCTSNAck sent:0x%x\n", __func__, ctsn);
772
773 /* How much room is needed in the chunk? */
774 num_gabs = sctp_tsnmap_num_gabs(map, gabs);
775 num_dup_tsns = sctp_tsnmap_num_dups(map);
776
777 /* Initialize the SACK header. */
778 sack.cum_tsn_ack = htonl(ctsn);
779 sack.a_rwnd = htonl(asoc->a_rwnd);
780 sack.num_gap_ack_blocks = htons(num_gabs);
781 sack.num_dup_tsns = htons(num_dup_tsns);
782
783 len = sizeof(sack)
784 + sizeof(struct sctp_gap_ack_block) * num_gabs
785 + sizeof(__u32) * num_dup_tsns;
786
787 /* Create the chunk. */
788 retval = sctp_make_control(asoc, SCTP_CID_SACK, 0, len, GFP_ATOMIC);
789 if (!retval)
790 goto nodata;
791
792 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
793 *
794 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
795 * HEARTBEAT ACK, etc.) to the same destination transport
796 * address from which it received the DATA or control chunk to
797 * which it is replying. This rule should also be followed if
798 * the endpoint is bundling DATA chunks together with the
799 * reply chunk.
800 *
801 * However, when acknowledging multiple DATA chunks received
802 * in packets from different source addresses in a single
803 * SACK, the SACK chunk may be transmitted to one of the
804 * destination transport addresses from which the DATA or
805 * control chunks being acknowledged were received.
806 *
807 * [BUG: We do not implement the following paragraph.
808 * Perhaps we should remember the last transport we used for a
809 * SACK and avoid that (if possible) if we have seen any
810 * duplicates. --piggy]
811 *
812 * When a receiver of a duplicate DATA chunk sends a SACK to a
813 * multi- homed endpoint it MAY be beneficial to vary the
814 * destination address and not use the source address of the
815 * DATA chunk. The reason being that receiving a duplicate
816 * from a multi-homed endpoint might indicate that the return
817 * path (as specified in the source address of the DATA chunk)
818 * for the SACK is broken.
819 *
820 * [Send to the address from which we last received a DATA chunk.]
821 */
822 retval->transport = asoc->peer.last_data_from;
823
824 retval->subh.sack_hdr =
825 sctp_addto_chunk(retval, sizeof(sack), &sack);
826
827 /* Add the gap ack block information. */
828 if (num_gabs)
829 sctp_addto_chunk(retval, sizeof(__u32) * num_gabs,
830 gabs);
831
832 /* Add the duplicate TSN information. */
833 if (num_dup_tsns) {
834 aptr->stats.idupchunks += num_dup_tsns;
835 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns,
836 sctp_tsnmap_get_dups(map));
837 }
838 /* Once we have a sack generated, check to see what our sack
839 * generation is, if its 0, reset the transports to 0, and reset
840 * the association generation to 1
841 *
842 * The idea is that zero is never used as a valid generation for the
843 * association so no transport will match after a wrap event like this,
844 * Until the next sack
845 */
846 if (++aptr->peer.sack_generation == 0) {
847 list_for_each_entry(trans, &asoc->peer.transport_addr_list,
848 transports)
849 trans->sack_generation = 0;
850 aptr->peer.sack_generation = 1;
851 }
852nodata:
853 return retval;
854}
855
856/* Make a SHUTDOWN chunk. */
857struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc,
858 const struct sctp_chunk *chunk)
859{
860 struct sctp_chunk *retval;
861 sctp_shutdownhdr_t shut;
862 __u32 ctsn;
863
864 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
865 shut.cum_tsn_ack = htonl(ctsn);
866
867 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN, 0,
868 sizeof(sctp_shutdownhdr_t), GFP_ATOMIC);
869 if (!retval)
870 goto nodata;
871
872 retval->subh.shutdown_hdr =
873 sctp_addto_chunk(retval, sizeof(shut), &shut);
874
875 if (chunk)
876 retval->transport = chunk->transport;
877nodata:
878 return retval;
879}
880
881struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc,
882 const struct sctp_chunk *chunk)
883{
884 struct sctp_chunk *retval;
885
886 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0,
887 GFP_ATOMIC);
888
889 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
890 *
891 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
892 * HEARTBEAT ACK, * etc.) to the same destination transport
893 * address from which it * received the DATA or control chunk
894 * to which it is replying.
895 *
896 * [ACK back to where the SHUTDOWN came from.]
897 */
898 if (retval && chunk)
899 retval->transport = chunk->transport;
900
901 return retval;
902}
903
904struct sctp_chunk *sctp_make_shutdown_complete(
905 const struct sctp_association *asoc,
906 const struct sctp_chunk *chunk)
907{
908 struct sctp_chunk *retval;
909 __u8 flags = 0;
910
911 /* Set the T-bit if we have no association (vtag will be
912 * reflected)
913 */
914 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T;
915
916 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags,
917 0, GFP_ATOMIC);
918
919 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
920 *
921 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
922 * HEARTBEAT ACK, * etc.) to the same destination transport
923 * address from which it * received the DATA or control chunk
924 * to which it is replying.
925 *
926 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK
927 * came from.]
928 */
929 if (retval && chunk)
930 retval->transport = chunk->transport;
931
932 return retval;
933}
934
935/* Create an ABORT. Note that we set the T bit if we have no
936 * association, except when responding to an INIT (sctpimpguide 2.41).
937 */
938struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc,
939 const struct sctp_chunk *chunk,
940 const size_t hint)
941{
942 struct sctp_chunk *retval;
943 __u8 flags = 0;
944
945 /* Set the T-bit if we have no association and 'chunk' is not
946 * an INIT (vtag will be reflected).
947 */
948 if (!asoc) {
949 if (chunk && chunk->chunk_hdr &&
950 chunk->chunk_hdr->type == SCTP_CID_INIT)
951 flags = 0;
952 else
953 flags = SCTP_CHUNK_FLAG_T;
954 }
955
956 retval = sctp_make_control(asoc, SCTP_CID_ABORT, flags, hint,
957 GFP_ATOMIC);
958
959 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
960 *
961 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
962 * HEARTBEAT ACK, * etc.) to the same destination transport
963 * address from which it * received the DATA or control chunk
964 * to which it is replying.
965 *
966 * [ABORT back to where the offender came from.]
967 */
968 if (retval && chunk)
969 retval->transport = chunk->transport;
970
971 return retval;
972}
973
974/* Helper to create ABORT with a NO_USER_DATA error. */
975struct sctp_chunk *sctp_make_abort_no_data(
976 const struct sctp_association *asoc,
977 const struct sctp_chunk *chunk, __u32 tsn)
978{
979 struct sctp_chunk *retval;
980 __be32 payload;
981
982 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t)
983 + sizeof(tsn));
984
985 if (!retval)
986 goto no_mem;
987
988 /* Put the tsn back into network byte order. */
989 payload = htonl(tsn);
990 sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload));
991 sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload);
992
993 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
994 *
995 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
996 * HEARTBEAT ACK, * etc.) to the same destination transport
997 * address from which it * received the DATA or control chunk
998 * to which it is replying.
999 *
1000 * [ABORT back to where the offender came from.]
1001 */
1002 if (chunk)
1003 retval->transport = chunk->transport;
1004
1005no_mem:
1006 return retval;
1007}
1008
1009/* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */
1010struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc,
1011 struct msghdr *msg,
1012 size_t paylen)
1013{
1014 struct sctp_chunk *retval;
1015 void *payload = NULL;
1016 int err;
1017
1018 retval = sctp_make_abort(asoc, NULL, sizeof(sctp_errhdr_t) + paylen);
1019 if (!retval)
1020 goto err_chunk;
1021
1022 if (paylen) {
1023 /* Put the msg_iov together into payload. */
1024 payload = kmalloc(paylen, GFP_KERNEL);
1025 if (!payload)
1026 goto err_payload;
1027
1028 err = memcpy_from_msg(payload, msg, paylen);
1029 if (err < 0)
1030 goto err_copy;
1031 }
1032
1033 sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen);
1034 sctp_addto_chunk(retval, paylen, payload);
1035
1036 if (paylen)
1037 kfree(payload);
1038
1039 return retval;
1040
1041err_copy:
1042 kfree(payload);
1043err_payload:
1044 sctp_chunk_free(retval);
1045 retval = NULL;
1046err_chunk:
1047 return retval;
1048}
1049
1050/* Append bytes to the end of a parameter. Will panic if chunk is not big
1051 * enough.
1052 */
1053static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
1054 const void *data)
1055{
1056 void *target;
1057 int chunklen = ntohs(chunk->chunk_hdr->length);
1058
1059 target = skb_put(chunk->skb, len);
1060
1061 if (data)
1062 memcpy(target, data, len);
1063 else
1064 memset(target, 0, len);
1065
1066 /* Adjust the chunk length field. */
1067 chunk->chunk_hdr->length = htons(chunklen + len);
1068 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1069
1070 return target;
1071}
1072
1073/* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */
1074struct sctp_chunk *sctp_make_abort_violation(
1075 const struct sctp_association *asoc,
1076 const struct sctp_chunk *chunk,
1077 const __u8 *payload,
1078 const size_t paylen)
1079{
1080 struct sctp_chunk *retval;
1081 struct sctp_paramhdr phdr;
1082
1083 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) + paylen
1084 + sizeof(sctp_paramhdr_t));
1085 if (!retval)
1086 goto end;
1087
1088 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen
1089 + sizeof(sctp_paramhdr_t));
1090
1091 phdr.type = htons(chunk->chunk_hdr->type);
1092 phdr.length = chunk->chunk_hdr->length;
1093 sctp_addto_chunk(retval, paylen, payload);
1094 sctp_addto_param(retval, sizeof(sctp_paramhdr_t), &phdr);
1095
1096end:
1097 return retval;
1098}
1099
1100struct sctp_chunk *sctp_make_violation_paramlen(
1101 const struct sctp_association *asoc,
1102 const struct sctp_chunk *chunk,
1103 struct sctp_paramhdr *param)
1104{
1105 struct sctp_chunk *retval;
1106 static const char error[] = "The following parameter had invalid length:";
1107 size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t) +
1108 sizeof(sctp_paramhdr_t);
1109
1110 retval = sctp_make_abort(asoc, chunk, payload_len);
1111 if (!retval)
1112 goto nodata;
1113
1114 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION,
1115 sizeof(error) + sizeof(sctp_paramhdr_t));
1116 sctp_addto_chunk(retval, sizeof(error), error);
1117 sctp_addto_param(retval, sizeof(sctp_paramhdr_t), param);
1118
1119nodata:
1120 return retval;
1121}
1122
1123struct sctp_chunk *sctp_make_violation_max_retrans(
1124 const struct sctp_association *asoc,
1125 const struct sctp_chunk *chunk)
1126{
1127 struct sctp_chunk *retval;
1128 static const char error[] = "Association exceeded its max_retans count";
1129 size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t);
1130
1131 retval = sctp_make_abort(asoc, chunk, payload_len);
1132 if (!retval)
1133 goto nodata;
1134
1135 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error));
1136 sctp_addto_chunk(retval, sizeof(error), error);
1137
1138nodata:
1139 return retval;
1140}
1141
1142/* Make a HEARTBEAT chunk. */
1143struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc,
1144 const struct sctp_transport *transport)
1145{
1146 struct sctp_chunk *retval;
1147 sctp_sender_hb_info_t hbinfo;
1148
1149 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT, 0,
1150 sizeof(hbinfo), GFP_ATOMIC);
1151
1152 if (!retval)
1153 goto nodata;
1154
1155 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO;
1156 hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t));
1157 hbinfo.daddr = transport->ipaddr;
1158 hbinfo.sent_at = jiffies;
1159 hbinfo.hb_nonce = transport->hb_nonce;
1160
1161 /* Cast away the 'const', as this is just telling the chunk
1162 * what transport it belongs to.
1163 */
1164 retval->transport = (struct sctp_transport *) transport;
1165 retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo),
1166 &hbinfo);
1167
1168nodata:
1169 return retval;
1170}
1171
1172struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc,
1173 const struct sctp_chunk *chunk,
1174 const void *payload, const size_t paylen)
1175{
1176 struct sctp_chunk *retval;
1177
1178 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen,
1179 GFP_ATOMIC);
1180 if (!retval)
1181 goto nodata;
1182
1183 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload);
1184
1185 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
1186 *
1187 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1188 * HEARTBEAT ACK, * etc.) to the same destination transport
1189 * address from which it * received the DATA or control chunk
1190 * to which it is replying.
1191 *
1192 * [HBACK back to where the HEARTBEAT came from.]
1193 */
1194 if (chunk)
1195 retval->transport = chunk->transport;
1196
1197nodata:
1198 return retval;
1199}
1200
1201/* Create an Operation Error chunk with the specified space reserved.
1202 * This routine can be used for containing multiple causes in the chunk.
1203 */
1204static struct sctp_chunk *sctp_make_op_error_space(
1205 const struct sctp_association *asoc,
1206 const struct sctp_chunk *chunk,
1207 size_t size)
1208{
1209 struct sctp_chunk *retval;
1210
1211 retval = sctp_make_control(asoc, SCTP_CID_ERROR, 0,
1212 sizeof(sctp_errhdr_t) + size, GFP_ATOMIC);
1213 if (!retval)
1214 goto nodata;
1215
1216 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
1217 *
1218 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1219 * HEARTBEAT ACK, etc.) to the same destination transport
1220 * address from which it received the DATA or control chunk
1221 * to which it is replying.
1222 *
1223 */
1224 if (chunk)
1225 retval->transport = chunk->transport;
1226
1227nodata:
1228 return retval;
1229}
1230
1231/* Create an Operation Error chunk of a fixed size,
1232 * specifically, max(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT)
1233 * This is a helper function to allocate an error chunk for
1234 * for those invalid parameter codes in which we may not want
1235 * to report all the errors, if the incoming chunk is large
1236 */
1237static inline struct sctp_chunk *sctp_make_op_error_fixed(
1238 const struct sctp_association *asoc,
1239 const struct sctp_chunk *chunk)
1240{
1241 size_t size = asoc ? asoc->pathmtu : 0;
1242
1243 if (!size)
1244 size = SCTP_DEFAULT_MAXSEGMENT;
1245
1246 return sctp_make_op_error_space(asoc, chunk, size);
1247}
1248
1249/* Create an Operation Error chunk. */
1250struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc,
1251 const struct sctp_chunk *chunk,
1252 __be16 cause_code, const void *payload,
1253 size_t paylen, size_t reserve_tail)
1254{
1255 struct sctp_chunk *retval;
1256
1257 retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail);
1258 if (!retval)
1259 goto nodata;
1260
1261 sctp_init_cause(retval, cause_code, paylen + reserve_tail);
1262 sctp_addto_chunk(retval, paylen, payload);
1263 if (reserve_tail)
1264 sctp_addto_param(retval, reserve_tail, NULL);
1265
1266nodata:
1267 return retval;
1268}
1269
1270struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc)
1271{
1272 struct sctp_chunk *retval;
1273 struct sctp_hmac *hmac_desc;
1274 struct sctp_authhdr auth_hdr;
1275 __u8 *hmac;
1276
1277 /* Get the first hmac that the peer told us to use */
1278 hmac_desc = sctp_auth_asoc_get_hmac(asoc);
1279 if (unlikely(!hmac_desc))
1280 return NULL;
1281
1282 retval = sctp_make_control(asoc, SCTP_CID_AUTH, 0,
1283 hmac_desc->hmac_len + sizeof(sctp_authhdr_t),
1284 GFP_ATOMIC);
1285 if (!retval)
1286 return NULL;
1287
1288 auth_hdr.hmac_id = htons(hmac_desc->hmac_id);
1289 auth_hdr.shkey_id = htons(asoc->active_key_id);
1290
1291 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(sctp_authhdr_t),
1292 &auth_hdr);
1293
1294 hmac = skb_put(retval->skb, hmac_desc->hmac_len);
1295 memset(hmac, 0, hmac_desc->hmac_len);
1296
1297 /* Adjust the chunk header to include the empty MAC */
1298 retval->chunk_hdr->length =
1299 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len);
1300 retval->chunk_end = skb_tail_pointer(retval->skb);
1301
1302 return retval;
1303}
1304
1305
1306/********************************************************************
1307 * 2nd Level Abstractions
1308 ********************************************************************/
1309
1310/* Turn an skb into a chunk.
1311 * FIXME: Eventually move the structure directly inside the skb->cb[].
1312 *
1313 * sctpimpguide-05.txt Section 2.8.2
1314 * M1) Each time a new DATA chunk is transmitted
1315 * set the 'TSN.Missing.Report' count for that TSN to 0. The
1316 * 'TSN.Missing.Report' count will be used to determine missing chunks
1317 * and when to fast retransmit.
1318 *
1319 */
1320struct sctp_chunk *sctp_chunkify(struct sk_buff *skb,
1321 const struct sctp_association *asoc,
1322 struct sock *sk, gfp_t gfp)
1323{
1324 struct sctp_chunk *retval;
1325
1326 retval = kmem_cache_zalloc(sctp_chunk_cachep, gfp);
1327
1328 if (!retval)
1329 goto nodata;
1330 if (!sk)
1331 pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb);
1332
1333 INIT_LIST_HEAD(&retval->list);
1334 retval->skb = skb;
1335 retval->asoc = (struct sctp_association *)asoc;
1336 retval->singleton = 1;
1337
1338 retval->fast_retransmit = SCTP_CAN_FRTX;
1339
1340 /* Polish the bead hole. */
1341 INIT_LIST_HEAD(&retval->transmitted_list);
1342 INIT_LIST_HEAD(&retval->frag_list);
1343 SCTP_DBG_OBJCNT_INC(chunk);
1344 atomic_set(&retval->refcnt, 1);
1345
1346nodata:
1347 return retval;
1348}
1349
1350/* Set chunk->source and dest based on the IP header in chunk->skb. */
1351void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src,
1352 union sctp_addr *dest)
1353{
1354 memcpy(&chunk->source, src, sizeof(union sctp_addr));
1355 memcpy(&chunk->dest, dest, sizeof(union sctp_addr));
1356}
1357
1358/* Extract the source address from a chunk. */
1359const union sctp_addr *sctp_source(const struct sctp_chunk *chunk)
1360{
1361 /* If we have a known transport, use that. */
1362 if (chunk->transport) {
1363 return &chunk->transport->ipaddr;
1364 } else {
1365 /* Otherwise, extract it from the IP header. */
1366 return &chunk->source;
1367 }
1368}
1369
1370/* Create a new chunk, setting the type and flags headers from the
1371 * arguments, reserving enough space for a 'paylen' byte payload.
1372 */
1373static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc,
1374 __u8 type, __u8 flags, int paylen,
1375 gfp_t gfp)
1376{
1377 struct sctp_chunk *retval;
1378 sctp_chunkhdr_t *chunk_hdr;
1379 struct sk_buff *skb;
1380 struct sock *sk;
1381
1382 /* No need to allocate LL here, as this is only a chunk. */
1383 skb = alloc_skb(WORD_ROUND(sizeof(sctp_chunkhdr_t) + paylen), gfp);
1384 if (!skb)
1385 goto nodata;
1386
1387 /* Make room for the chunk header. */
1388 chunk_hdr = (sctp_chunkhdr_t *)skb_put(skb, sizeof(sctp_chunkhdr_t));
1389 chunk_hdr->type = type;
1390 chunk_hdr->flags = flags;
1391 chunk_hdr->length = htons(sizeof(sctp_chunkhdr_t));
1392
1393 sk = asoc ? asoc->base.sk : NULL;
1394 retval = sctp_chunkify(skb, asoc, sk, gfp);
1395 if (!retval) {
1396 kfree_skb(skb);
1397 goto nodata;
1398 }
1399
1400 retval->chunk_hdr = chunk_hdr;
1401 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(struct sctp_chunkhdr);
1402
1403 /* Determine if the chunk needs to be authenticated */
1404 if (sctp_auth_send_cid(type, asoc))
1405 retval->auth = 1;
1406
1407 return retval;
1408nodata:
1409 return NULL;
1410}
1411
1412static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc,
1413 __u8 flags, int paylen, gfp_t gfp)
1414{
1415 return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen, gfp);
1416}
1417
1418static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc,
1419 __u8 type, __u8 flags, int paylen,
1420 gfp_t gfp)
1421{
1422 struct sctp_chunk *chunk;
1423
1424 chunk = _sctp_make_chunk(asoc, type, flags, paylen, gfp);
1425 if (chunk)
1426 sctp_control_set_owner_w(chunk);
1427
1428 return chunk;
1429}
1430
1431/* Release the memory occupied by a chunk. */
1432static void sctp_chunk_destroy(struct sctp_chunk *chunk)
1433{
1434 BUG_ON(!list_empty(&chunk->list));
1435 list_del_init(&chunk->transmitted_list);
1436
1437 consume_skb(chunk->skb);
1438 consume_skb(chunk->auth_chunk);
1439
1440 SCTP_DBG_OBJCNT_DEC(chunk);
1441 kmem_cache_free(sctp_chunk_cachep, chunk);
1442}
1443
1444/* Possibly, free the chunk. */
1445void sctp_chunk_free(struct sctp_chunk *chunk)
1446{
1447 /* Release our reference on the message tracker. */
1448 if (chunk->msg)
1449 sctp_datamsg_put(chunk->msg);
1450
1451 sctp_chunk_put(chunk);
1452}
1453
1454/* Grab a reference to the chunk. */
1455void sctp_chunk_hold(struct sctp_chunk *ch)
1456{
1457 atomic_inc(&ch->refcnt);
1458}
1459
1460/* Release a reference to the chunk. */
1461void sctp_chunk_put(struct sctp_chunk *ch)
1462{
1463 if (atomic_dec_and_test(&ch->refcnt))
1464 sctp_chunk_destroy(ch);
1465}
1466
1467/* Append bytes to the end of a chunk. Will panic if chunk is not big
1468 * enough.
1469 */
1470void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data)
1471{
1472 void *target;
1473 void *padding;
1474 int chunklen = ntohs(chunk->chunk_hdr->length);
1475 int padlen = WORD_ROUND(chunklen) - chunklen;
1476
1477 padding = skb_put(chunk->skb, padlen);
1478 target = skb_put(chunk->skb, len);
1479
1480 memset(padding, 0, padlen);
1481 memcpy(target, data, len);
1482
1483 /* Adjust the chunk length field. */
1484 chunk->chunk_hdr->length = htons(chunklen + padlen + len);
1485 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1486
1487 return target;
1488}
1489
1490/* Append bytes to the end of a chunk. Returns NULL if there isn't sufficient
1491 * space in the chunk
1492 */
1493static void *sctp_addto_chunk_fixed(struct sctp_chunk *chunk,
1494 int len, const void *data)
1495{
1496 if (skb_tailroom(chunk->skb) >= len)
1497 return sctp_addto_chunk(chunk, len, data);
1498 else
1499 return NULL;
1500}
1501
1502/* Append bytes from user space to the end of a chunk. Will panic if
1503 * chunk is not big enough.
1504 * Returns a kernel err value.
1505 */
1506int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
1507 struct iov_iter *from)
1508{
1509 void *target;
1510 ssize_t copied;
1511
1512 /* Make room in chunk for data. */
1513 target = skb_put(chunk->skb, len);
1514
1515 /* Copy data (whole iovec) into chunk */
1516 copied = copy_from_iter(target, len, from);
1517 if (copied != len)
1518 return -EFAULT;
1519
1520 /* Adjust the chunk length field. */
1521 chunk->chunk_hdr->length =
1522 htons(ntohs(chunk->chunk_hdr->length) + len);
1523 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1524
1525 return 0;
1526}
1527
1528/* Helper function to assign a TSN if needed. This assumes that both
1529 * the data_hdr and association have already been assigned.
1530 */
1531void sctp_chunk_assign_ssn(struct sctp_chunk *chunk)
1532{
1533 struct sctp_datamsg *msg;
1534 struct sctp_chunk *lchunk;
1535 struct sctp_stream *stream;
1536 __u16 ssn;
1537 __u16 sid;
1538
1539 if (chunk->has_ssn)
1540 return;
1541
1542 /* All fragments will be on the same stream */
1543 sid = ntohs(chunk->subh.data_hdr->stream);
1544 stream = &chunk->asoc->ssnmap->out;
1545
1546 /* Now assign the sequence number to the entire message.
1547 * All fragments must have the same stream sequence number.
1548 */
1549 msg = chunk->msg;
1550 list_for_each_entry(lchunk, &msg->chunks, frag_list) {
1551 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
1552 ssn = 0;
1553 } else {
1554 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG)
1555 ssn = sctp_ssn_next(stream, sid);
1556 else
1557 ssn = sctp_ssn_peek(stream, sid);
1558 }
1559
1560 lchunk->subh.data_hdr->ssn = htons(ssn);
1561 lchunk->has_ssn = 1;
1562 }
1563}
1564
1565/* Helper function to assign a TSN if needed. This assumes that both
1566 * the data_hdr and association have already been assigned.
1567 */
1568void sctp_chunk_assign_tsn(struct sctp_chunk *chunk)
1569{
1570 if (!chunk->has_tsn) {
1571 /* This is the last possible instant to
1572 * assign a TSN.
1573 */
1574 chunk->subh.data_hdr->tsn =
1575 htonl(sctp_association_get_next_tsn(chunk->asoc));
1576 chunk->has_tsn = 1;
1577 }
1578}
1579
1580/* Create a CLOSED association to use with an incoming packet. */
1581struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep,
1582 struct sctp_chunk *chunk,
1583 gfp_t gfp)
1584{
1585 struct sctp_association *asoc;
1586 struct sk_buff *skb;
1587 sctp_scope_t scope;
1588 struct sctp_af *af;
1589
1590 /* Create the bare association. */
1591 scope = sctp_scope(sctp_source(chunk));
1592 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp);
1593 if (!asoc)
1594 goto nodata;
1595 asoc->temp = 1;
1596 skb = chunk->skb;
1597 /* Create an entry for the source address of the packet. */
1598 af = sctp_get_af_specific(ipver2af(ip_hdr(skb)->version));
1599 if (unlikely(!af))
1600 goto fail;
1601 af->from_skb(&asoc->c.peer_addr, skb, 1);
1602nodata:
1603 return asoc;
1604
1605fail:
1606 sctp_association_free(asoc);
1607 return NULL;
1608}
1609
1610/* Build a cookie representing asoc.
1611 * This INCLUDES the param header needed to put the cookie in the INIT ACK.
1612 */
1613static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep,
1614 const struct sctp_association *asoc,
1615 const struct sctp_chunk *init_chunk,
1616 int *cookie_len,
1617 const __u8 *raw_addrs, int addrs_len)
1618{
1619 sctp_cookie_param_t *retval;
1620 struct sctp_signed_cookie *cookie;
1621 int headersize, bodysize;
1622
1623 /* Header size is static data prior to the actual cookie, including
1624 * any padding.
1625 */
1626 headersize = sizeof(sctp_paramhdr_t) +
1627 (sizeof(struct sctp_signed_cookie) -
1628 sizeof(struct sctp_cookie));
1629 bodysize = sizeof(struct sctp_cookie)
1630 + ntohs(init_chunk->chunk_hdr->length) + addrs_len;
1631
1632 /* Pad out the cookie to a multiple to make the signature
1633 * functions simpler to write.
1634 */
1635 if (bodysize % SCTP_COOKIE_MULTIPLE)
1636 bodysize += SCTP_COOKIE_MULTIPLE
1637 - (bodysize % SCTP_COOKIE_MULTIPLE);
1638 *cookie_len = headersize + bodysize;
1639
1640 /* Clear this memory since we are sending this data structure
1641 * out on the network.
1642 */
1643 retval = kzalloc(*cookie_len, GFP_ATOMIC);
1644 if (!retval)
1645 goto nodata;
1646
1647 cookie = (struct sctp_signed_cookie *) retval->body;
1648
1649 /* Set up the parameter header. */
1650 retval->p.type = SCTP_PARAM_STATE_COOKIE;
1651 retval->p.length = htons(*cookie_len);
1652
1653 /* Copy the cookie part of the association itself. */
1654 cookie->c = asoc->c;
1655 /* Save the raw address list length in the cookie. */
1656 cookie->c.raw_addr_list_len = addrs_len;
1657
1658 /* Remember PR-SCTP capability. */
1659 cookie->c.prsctp_capable = asoc->peer.prsctp_capable;
1660
1661 /* Save adaptation indication in the cookie. */
1662 cookie->c.adaptation_ind = asoc->peer.adaptation_ind;
1663
1664 /* Set an expiration time for the cookie. */
1665 cookie->c.expiration = ktime_add(asoc->cookie_life,
1666 ktime_get_real());
1667
1668 /* Copy the peer's init packet. */
1669 memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr,
1670 ntohs(init_chunk->chunk_hdr->length));
1671
1672 /* Copy the raw local address list of the association. */
1673 memcpy((__u8 *)&cookie->c.peer_init[0] +
1674 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len);
1675
1676 if (sctp_sk(ep->base.sk)->hmac) {
1677 SHASH_DESC_ON_STACK(desc, sctp_sk(ep->base.sk)->hmac);
1678 int err;
1679
1680 /* Sign the message. */
1681 desc->tfm = sctp_sk(ep->base.sk)->hmac;
1682 desc->flags = 0;
1683
1684 err = crypto_shash_setkey(desc->tfm, ep->secret_key,
1685 sizeof(ep->secret_key)) ?:
1686 crypto_shash_digest(desc, (u8 *)&cookie->c, bodysize,
1687 cookie->signature);
1688 shash_desc_zero(desc);
1689 if (err)
1690 goto free_cookie;
1691 }
1692
1693 return retval;
1694
1695free_cookie:
1696 kfree(retval);
1697nodata:
1698 *cookie_len = 0;
1699 return NULL;
1700}
1701
1702/* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */
1703struct sctp_association *sctp_unpack_cookie(
1704 const struct sctp_endpoint *ep,
1705 const struct sctp_association *asoc,
1706 struct sctp_chunk *chunk, gfp_t gfp,
1707 int *error, struct sctp_chunk **errp)
1708{
1709 struct sctp_association *retval = NULL;
1710 struct sctp_signed_cookie *cookie;
1711 struct sctp_cookie *bear_cookie;
1712 int headersize, bodysize, fixed_size;
1713 __u8 *digest = ep->digest;
1714 unsigned int len;
1715 sctp_scope_t scope;
1716 struct sk_buff *skb = chunk->skb;
1717 ktime_t kt;
1718
1719 /* Header size is static data prior to the actual cookie, including
1720 * any padding.
1721 */
1722 headersize = sizeof(sctp_chunkhdr_t) +
1723 (sizeof(struct sctp_signed_cookie) -
1724 sizeof(struct sctp_cookie));
1725 bodysize = ntohs(chunk->chunk_hdr->length) - headersize;
1726 fixed_size = headersize + sizeof(struct sctp_cookie);
1727
1728 /* Verify that the chunk looks like it even has a cookie.
1729 * There must be enough room for our cookie and our peer's
1730 * INIT chunk.
1731 */
1732 len = ntohs(chunk->chunk_hdr->length);
1733 if (len < fixed_size + sizeof(struct sctp_chunkhdr))
1734 goto malformed;
1735
1736 /* Verify that the cookie has been padded out. */
1737 if (bodysize % SCTP_COOKIE_MULTIPLE)
1738 goto malformed;
1739
1740 /* Process the cookie. */
1741 cookie = chunk->subh.cookie_hdr;
1742 bear_cookie = &cookie->c;
1743
1744 if (!sctp_sk(ep->base.sk)->hmac)
1745 goto no_hmac;
1746
1747 /* Check the signature. */
1748 {
1749 SHASH_DESC_ON_STACK(desc, sctp_sk(ep->base.sk)->hmac);
1750 int err;
1751
1752 desc->tfm = sctp_sk(ep->base.sk)->hmac;
1753 desc->flags = 0;
1754
1755 err = crypto_shash_setkey(desc->tfm, ep->secret_key,
1756 sizeof(ep->secret_key)) ?:
1757 crypto_shash_digest(desc, (u8 *)bear_cookie, bodysize,
1758 digest);
1759 shash_desc_zero(desc);
1760
1761 if (err) {
1762 *error = -SCTP_IERROR_NOMEM;
1763 goto fail;
1764 }
1765 }
1766
1767 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
1768 *error = -SCTP_IERROR_BAD_SIG;
1769 goto fail;
1770 }
1771
1772no_hmac:
1773 /* IG Section 2.35.2:
1774 * 3) Compare the port numbers and the verification tag contained
1775 * within the COOKIE ECHO chunk to the actual port numbers and the
1776 * verification tag within the SCTP common header of the received
1777 * packet. If these values do not match the packet MUST be silently
1778 * discarded,
1779 */
1780 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) {
1781 *error = -SCTP_IERROR_BAD_TAG;
1782 goto fail;
1783 }
1784
1785 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port ||
1786 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) {
1787 *error = -SCTP_IERROR_BAD_PORTS;
1788 goto fail;
1789 }
1790
1791 /* Check to see if the cookie is stale. If there is already
1792 * an association, there is no need to check cookie's expiration
1793 * for init collision case of lost COOKIE ACK.
1794 * If skb has been timestamped, then use the stamp, otherwise
1795 * use current time. This introduces a small possibility that
1796 * that a cookie may be considered expired, but his would only slow
1797 * down the new association establishment instead of every packet.
1798 */
1799 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP))
1800 kt = skb_get_ktime(skb);
1801 else
1802 kt = ktime_get_real();
1803
1804 if (!asoc && ktime_before(bear_cookie->expiration, kt)) {
1805 /*
1806 * Section 3.3.10.3 Stale Cookie Error (3)
1807 *
1808 * Cause of error
1809 * ---------------
1810 * Stale Cookie Error: Indicates the receipt of a valid State
1811 * Cookie that has expired.
1812 */
1813 len = ntohs(chunk->chunk_hdr->length);
1814 *errp = sctp_make_op_error_space(asoc, chunk, len);
1815 if (*errp) {
1816 suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration));
1817 __be32 n = htonl(usecs);
1818
1819 sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE,
1820 sizeof(n));
1821 sctp_addto_chunk(*errp, sizeof(n), &n);
1822 *error = -SCTP_IERROR_STALE_COOKIE;
1823 } else
1824 *error = -SCTP_IERROR_NOMEM;
1825
1826 goto fail;
1827 }
1828
1829 /* Make a new base association. */
1830 scope = sctp_scope(sctp_source(chunk));
1831 retval = sctp_association_new(ep, ep->base.sk, scope, gfp);
1832 if (!retval) {
1833 *error = -SCTP_IERROR_NOMEM;
1834 goto fail;
1835 }
1836
1837 /* Set up our peer's port number. */
1838 retval->peer.port = ntohs(chunk->sctp_hdr->source);
1839
1840 /* Populate the association from the cookie. */
1841 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie));
1842
1843 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie,
1844 GFP_ATOMIC) < 0) {
1845 *error = -SCTP_IERROR_NOMEM;
1846 goto fail;
1847 }
1848
1849 /* Also, add the destination address. */
1850 if (list_empty(&retval->base.bind_addr.address_list)) {
1851 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest,
1852 sizeof(chunk->dest), SCTP_ADDR_SRC,
1853 GFP_ATOMIC);
1854 }
1855
1856 retval->next_tsn = retval->c.initial_tsn;
1857 retval->ctsn_ack_point = retval->next_tsn - 1;
1858 retval->addip_serial = retval->c.initial_tsn;
1859 retval->adv_peer_ack_point = retval->ctsn_ack_point;
1860 retval->peer.prsctp_capable = retval->c.prsctp_capable;
1861 retval->peer.adaptation_ind = retval->c.adaptation_ind;
1862
1863 /* The INIT stuff will be done by the side effects. */
1864 return retval;
1865
1866fail:
1867 if (retval)
1868 sctp_association_free(retval);
1869
1870 return NULL;
1871
1872malformed:
1873 /* Yikes! The packet is either corrupt or deliberately
1874 * malformed.
1875 */
1876 *error = -SCTP_IERROR_MALFORMED;
1877 goto fail;
1878}
1879
1880/********************************************************************
1881 * 3rd Level Abstractions
1882 ********************************************************************/
1883
1884struct __sctp_missing {
1885 __be32 num_missing;
1886 __be16 type;
1887} __packed;
1888
1889/*
1890 * Report a missing mandatory parameter.
1891 */
1892static int sctp_process_missing_param(const struct sctp_association *asoc,
1893 sctp_param_t paramtype,
1894 struct sctp_chunk *chunk,
1895 struct sctp_chunk **errp)
1896{
1897 struct __sctp_missing report;
1898 __u16 len;
1899
1900 len = WORD_ROUND(sizeof(report));
1901
1902 /* Make an ERROR chunk, preparing enough room for
1903 * returning multiple unknown parameters.
1904 */
1905 if (!*errp)
1906 *errp = sctp_make_op_error_space(asoc, chunk, len);
1907
1908 if (*errp) {
1909 report.num_missing = htonl(1);
1910 report.type = paramtype;
1911 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM,
1912 sizeof(report));
1913 sctp_addto_chunk(*errp, sizeof(report), &report);
1914 }
1915
1916 /* Stop processing this chunk. */
1917 return 0;
1918}
1919
1920/* Report an Invalid Mandatory Parameter. */
1921static int sctp_process_inv_mandatory(const struct sctp_association *asoc,
1922 struct sctp_chunk *chunk,
1923 struct sctp_chunk **errp)
1924{
1925 /* Invalid Mandatory Parameter Error has no payload. */
1926
1927 if (!*errp)
1928 *errp = sctp_make_op_error_space(asoc, chunk, 0);
1929
1930 if (*errp)
1931 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0);
1932
1933 /* Stop processing this chunk. */
1934 return 0;
1935}
1936
1937static int sctp_process_inv_paramlength(const struct sctp_association *asoc,
1938 struct sctp_paramhdr *param,
1939 const struct sctp_chunk *chunk,
1940 struct sctp_chunk **errp)
1941{
1942 /* This is a fatal error. Any accumulated non-fatal errors are
1943 * not reported.
1944 */
1945 if (*errp)
1946 sctp_chunk_free(*errp);
1947
1948 /* Create an error chunk and fill it in with our payload. */
1949 *errp = sctp_make_violation_paramlen(asoc, chunk, param);
1950
1951 return 0;
1952}
1953
1954
1955/* Do not attempt to handle the HOST_NAME parm. However, do
1956 * send back an indicator to the peer.
1957 */
1958static int sctp_process_hn_param(const struct sctp_association *asoc,
1959 union sctp_params param,
1960 struct sctp_chunk *chunk,
1961 struct sctp_chunk **errp)
1962{
1963 __u16 len = ntohs(param.p->length);
1964
1965 /* Processing of the HOST_NAME parameter will generate an
1966 * ABORT. If we've accumulated any non-fatal errors, they
1967 * would be unrecognized parameters and we should not include
1968 * them in the ABORT.
1969 */
1970 if (*errp)
1971 sctp_chunk_free(*errp);
1972
1973 *errp = sctp_make_op_error_space(asoc, chunk, len);
1974
1975 if (*errp) {
1976 sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, len);
1977 sctp_addto_chunk(*errp, len, param.v);
1978 }
1979
1980 /* Stop processing this chunk. */
1981 return 0;
1982}
1983
1984static int sctp_verify_ext_param(struct net *net, union sctp_params param)
1985{
1986 __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
1987 int have_auth = 0;
1988 int have_asconf = 0;
1989 int i;
1990
1991 for (i = 0; i < num_ext; i++) {
1992 switch (param.ext->chunks[i]) {
1993 case SCTP_CID_AUTH:
1994 have_auth = 1;
1995 break;
1996 case SCTP_CID_ASCONF:
1997 case SCTP_CID_ASCONF_ACK:
1998 have_asconf = 1;
1999 break;
2000 }
2001 }
2002
2003 /* ADD-IP Security: The draft requires us to ABORT or ignore the
2004 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this
2005 * only if ADD-IP is turned on and we are not backward-compatible
2006 * mode.
2007 */
2008 if (net->sctp.addip_noauth)
2009 return 1;
2010
2011 if (net->sctp.addip_enable && !have_auth && have_asconf)
2012 return 0;
2013
2014 return 1;
2015}
2016
2017static void sctp_process_ext_param(struct sctp_association *asoc,
2018 union sctp_params param)
2019{
2020 struct net *net = sock_net(asoc->base.sk);
2021 __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
2022 int i;
2023
2024 for (i = 0; i < num_ext; i++) {
2025 switch (param.ext->chunks[i]) {
2026 case SCTP_CID_FWD_TSN:
2027 if (net->sctp.prsctp_enable && !asoc->peer.prsctp_capable)
2028 asoc->peer.prsctp_capable = 1;
2029 break;
2030 case SCTP_CID_AUTH:
2031 /* if the peer reports AUTH, assume that he
2032 * supports AUTH.
2033 */
2034 if (asoc->ep->auth_enable)
2035 asoc->peer.auth_capable = 1;
2036 break;
2037 case SCTP_CID_ASCONF:
2038 case SCTP_CID_ASCONF_ACK:
2039 if (net->sctp.addip_enable)
2040 asoc->peer.asconf_capable = 1;
2041 break;
2042 default:
2043 break;
2044 }
2045 }
2046}
2047
2048/* RFC 3.2.1 & the Implementers Guide 2.2.
2049 *
2050 * The Parameter Types are encoded such that the
2051 * highest-order two bits specify the action that must be
2052 * taken if the processing endpoint does not recognize the
2053 * Parameter Type.
2054 *
2055 * 00 - Stop processing this parameter; do not process any further
2056 * parameters within this chunk
2057 *
2058 * 01 - Stop processing this parameter, do not process any further
2059 * parameters within this chunk, and report the unrecognized
2060 * parameter in an 'Unrecognized Parameter' ERROR chunk.
2061 *
2062 * 10 - Skip this parameter and continue processing.
2063 *
2064 * 11 - Skip this parameter and continue processing but
2065 * report the unrecognized parameter in an
2066 * 'Unrecognized Parameter' ERROR chunk.
2067 *
2068 * Return value:
2069 * SCTP_IERROR_NO_ERROR - continue with the chunk
2070 * SCTP_IERROR_ERROR - stop and report an error.
2071 * SCTP_IERROR_NOMEME - out of memory.
2072 */
2073static sctp_ierror_t sctp_process_unk_param(const struct sctp_association *asoc,
2074 union sctp_params param,
2075 struct sctp_chunk *chunk,
2076 struct sctp_chunk **errp)
2077{
2078 int retval = SCTP_IERROR_NO_ERROR;
2079
2080 switch (param.p->type & SCTP_PARAM_ACTION_MASK) {
2081 case SCTP_PARAM_ACTION_DISCARD:
2082 retval = SCTP_IERROR_ERROR;
2083 break;
2084 case SCTP_PARAM_ACTION_SKIP:
2085 break;
2086 case SCTP_PARAM_ACTION_DISCARD_ERR:
2087 retval = SCTP_IERROR_ERROR;
2088 /* Fall through */
2089 case SCTP_PARAM_ACTION_SKIP_ERR:
2090 /* Make an ERROR chunk, preparing enough room for
2091 * returning multiple unknown parameters.
2092 */
2093 if (NULL == *errp)
2094 *errp = sctp_make_op_error_fixed(asoc, chunk);
2095
2096 if (*errp) {
2097 if (!sctp_init_cause_fixed(*errp, SCTP_ERROR_UNKNOWN_PARAM,
2098 WORD_ROUND(ntohs(param.p->length))))
2099 sctp_addto_chunk_fixed(*errp,
2100 WORD_ROUND(ntohs(param.p->length)),
2101 param.v);
2102 } else {
2103 /* If there is no memory for generating the ERROR
2104 * report as specified, an ABORT will be triggered
2105 * to the peer and the association won't be
2106 * established.
2107 */
2108 retval = SCTP_IERROR_NOMEM;
2109 }
2110 break;
2111 default:
2112 break;
2113 }
2114
2115 return retval;
2116}
2117
2118/* Verify variable length parameters
2119 * Return values:
2120 * SCTP_IERROR_ABORT - trigger an ABORT
2121 * SCTP_IERROR_NOMEM - out of memory (abort)
2122 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR
2123 * SCTP_IERROR_NO_ERROR - continue with the chunk
2124 */
2125static sctp_ierror_t sctp_verify_param(struct net *net,
2126 const struct sctp_endpoint *ep,
2127 const struct sctp_association *asoc,
2128 union sctp_params param,
2129 sctp_cid_t cid,
2130 struct sctp_chunk *chunk,
2131 struct sctp_chunk **err_chunk)
2132{
2133 struct sctp_hmac_algo_param *hmacs;
2134 int retval = SCTP_IERROR_NO_ERROR;
2135 __u16 n_elt, id = 0;
2136 int i;
2137
2138 /* FIXME - This routine is not looking at each parameter per the
2139 * chunk type, i.e., unrecognized parameters should be further
2140 * identified based on the chunk id.
2141 */
2142
2143 switch (param.p->type) {
2144 case SCTP_PARAM_IPV4_ADDRESS:
2145 case SCTP_PARAM_IPV6_ADDRESS:
2146 case SCTP_PARAM_COOKIE_PRESERVATIVE:
2147 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
2148 case SCTP_PARAM_STATE_COOKIE:
2149 case SCTP_PARAM_HEARTBEAT_INFO:
2150 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
2151 case SCTP_PARAM_ECN_CAPABLE:
2152 case SCTP_PARAM_ADAPTATION_LAYER_IND:
2153 break;
2154
2155 case SCTP_PARAM_SUPPORTED_EXT:
2156 if (!sctp_verify_ext_param(net, param))
2157 return SCTP_IERROR_ABORT;
2158 break;
2159
2160 case SCTP_PARAM_SET_PRIMARY:
2161 if (net->sctp.addip_enable)
2162 break;
2163 goto fallthrough;
2164
2165 case SCTP_PARAM_HOST_NAME_ADDRESS:
2166 /* Tell the peer, we won't support this param. */
2167 sctp_process_hn_param(asoc, param, chunk, err_chunk);
2168 retval = SCTP_IERROR_ABORT;
2169 break;
2170
2171 case SCTP_PARAM_FWD_TSN_SUPPORT:
2172 if (net->sctp.prsctp_enable)
2173 break;
2174 goto fallthrough;
2175
2176 case SCTP_PARAM_RANDOM:
2177 if (!ep->auth_enable)
2178 goto fallthrough;
2179
2180 /* SCTP-AUTH: Secion 6.1
2181 * If the random number is not 32 byte long the association
2182 * MUST be aborted. The ABORT chunk SHOULD contain the error
2183 * cause 'Protocol Violation'.
2184 */
2185 if (SCTP_AUTH_RANDOM_LENGTH !=
2186 ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) {
2187 sctp_process_inv_paramlength(asoc, param.p,
2188 chunk, err_chunk);
2189 retval = SCTP_IERROR_ABORT;
2190 }
2191 break;
2192
2193 case SCTP_PARAM_CHUNKS:
2194 if (!ep->auth_enable)
2195 goto fallthrough;
2196
2197 /* SCTP-AUTH: Section 3.2
2198 * The CHUNKS parameter MUST be included once in the INIT or
2199 * INIT-ACK chunk if the sender wants to receive authenticated
2200 * chunks. Its maximum length is 260 bytes.
2201 */
2202 if (260 < ntohs(param.p->length)) {
2203 sctp_process_inv_paramlength(asoc, param.p,
2204 chunk, err_chunk);
2205 retval = SCTP_IERROR_ABORT;
2206 }
2207 break;
2208
2209 case SCTP_PARAM_HMAC_ALGO:
2210 if (!ep->auth_enable)
2211 goto fallthrough;
2212
2213 hmacs = (struct sctp_hmac_algo_param *)param.p;
2214 n_elt = (ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) >> 1;
2215
2216 /* SCTP-AUTH: Section 6.1
2217 * The HMAC algorithm based on SHA-1 MUST be supported and
2218 * included in the HMAC-ALGO parameter.
2219 */
2220 for (i = 0; i < n_elt; i++) {
2221 id = ntohs(hmacs->hmac_ids[i]);
2222
2223 if (id == SCTP_AUTH_HMAC_ID_SHA1)
2224 break;
2225 }
2226
2227 if (id != SCTP_AUTH_HMAC_ID_SHA1) {
2228 sctp_process_inv_paramlength(asoc, param.p, chunk,
2229 err_chunk);
2230 retval = SCTP_IERROR_ABORT;
2231 }
2232 break;
2233fallthrough:
2234 default:
2235 pr_debug("%s: unrecognized param:%d for chunk:%d\n",
2236 __func__, ntohs(param.p->type), cid);
2237
2238 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk);
2239 break;
2240 }
2241 return retval;
2242}
2243
2244/* Verify the INIT packet before we process it. */
2245int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
2246 const struct sctp_association *asoc, sctp_cid_t cid,
2247 sctp_init_chunk_t *peer_init, struct sctp_chunk *chunk,
2248 struct sctp_chunk **errp)
2249{
2250 union sctp_params param;
2251 bool has_cookie = false;
2252 int result;
2253
2254 /* Check for missing mandatory parameters. Note: Initial TSN is
2255 * also mandatory, but is not checked here since the valid range
2256 * is 0..2**32-1. RFC4960, section 3.3.3.
2257 */
2258 if (peer_init->init_hdr.num_outbound_streams == 0 ||
2259 peer_init->init_hdr.num_inbound_streams == 0 ||
2260 peer_init->init_hdr.init_tag == 0 ||
2261 ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW)
2262 return sctp_process_inv_mandatory(asoc, chunk, errp);
2263
2264 sctp_walk_params(param, peer_init, init_hdr.params) {
2265 if (param.p->type == SCTP_PARAM_STATE_COOKIE)
2266 has_cookie = true;
2267 }
2268
2269 /* There is a possibility that a parameter length was bad and
2270 * in that case we would have stoped walking the parameters.
2271 * The current param.p would point at the bad one.
2272 * Current consensus on the mailing list is to generate a PROTOCOL
2273 * VIOLATION error. We build the ERROR chunk here and let the normal
2274 * error handling code build and send the packet.
2275 */
2276 if (param.v != (void *)chunk->chunk_end)
2277 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp);
2278
2279 /* The only missing mandatory param possible today is
2280 * the state cookie for an INIT-ACK chunk.
2281 */
2282 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie)
2283 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE,
2284 chunk, errp);
2285
2286 /* Verify all the variable length parameters */
2287 sctp_walk_params(param, peer_init, init_hdr.params) {
2288 result = sctp_verify_param(net, ep, asoc, param, cid,
2289 chunk, errp);
2290 switch (result) {
2291 case SCTP_IERROR_ABORT:
2292 case SCTP_IERROR_NOMEM:
2293 return 0;
2294 case SCTP_IERROR_ERROR:
2295 return 1;
2296 case SCTP_IERROR_NO_ERROR:
2297 default:
2298 break;
2299 }
2300
2301 } /* for (loop through all parameters) */
2302
2303 return 1;
2304}
2305
2306/* Unpack the parameters in an INIT packet into an association.
2307 * Returns 0 on failure, else success.
2308 * FIXME: This is an association method.
2309 */
2310int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk,
2311 const union sctp_addr *peer_addr,
2312 sctp_init_chunk_t *peer_init, gfp_t gfp)
2313{
2314 struct net *net = sock_net(asoc->base.sk);
2315 union sctp_params param;
2316 struct sctp_transport *transport;
2317 struct list_head *pos, *temp;
2318 struct sctp_af *af;
2319 union sctp_addr addr;
2320 char *cookie;
2321 int src_match = 0;
2322
2323 /* We must include the address that the INIT packet came from.
2324 * This is the only address that matters for an INIT packet.
2325 * When processing a COOKIE ECHO, we retrieve the from address
2326 * of the INIT from the cookie.
2327 */
2328
2329 /* This implementation defaults to making the first transport
2330 * added as the primary transport. The source address seems to
2331 * be a a better choice than any of the embedded addresses.
2332 */
2333 if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE))
2334 goto nomem;
2335
2336 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr))
2337 src_match = 1;
2338
2339 /* Process the initialization parameters. */
2340 sctp_walk_params(param, peer_init, init_hdr.params) {
2341 if (!src_match && (param.p->type == SCTP_PARAM_IPV4_ADDRESS ||
2342 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) {
2343 af = sctp_get_af_specific(param_type2af(param.p->type));
2344 af->from_addr_param(&addr, param.addr,
2345 chunk->sctp_hdr->source, 0);
2346 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr))
2347 src_match = 1;
2348 }
2349
2350 if (!sctp_process_param(asoc, param, peer_addr, gfp))
2351 goto clean_up;
2352 }
2353
2354 /* source address of chunk may not match any valid address */
2355 if (!src_match)
2356 goto clean_up;
2357
2358 /* AUTH: After processing the parameters, make sure that we
2359 * have all the required info to potentially do authentications.
2360 */
2361 if (asoc->peer.auth_capable && (!asoc->peer.peer_random ||
2362 !asoc->peer.peer_hmacs))
2363 asoc->peer.auth_capable = 0;
2364
2365 /* In a non-backward compatible mode, if the peer claims
2366 * support for ADD-IP but not AUTH, the ADD-IP spec states
2367 * that we MUST ABORT the association. Section 6. The section
2368 * also give us an option to silently ignore the packet, which
2369 * is what we'll do here.
2370 */
2371 if (!net->sctp.addip_noauth &&
2372 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) {
2373 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP |
2374 SCTP_PARAM_DEL_IP |
2375 SCTP_PARAM_SET_PRIMARY);
2376 asoc->peer.asconf_capable = 0;
2377 goto clean_up;
2378 }
2379
2380 /* Walk list of transports, removing transports in the UNKNOWN state. */
2381 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
2382 transport = list_entry(pos, struct sctp_transport, transports);
2383 if (transport->state == SCTP_UNKNOWN) {
2384 sctp_assoc_rm_peer(asoc, transport);
2385 }
2386 }
2387
2388 /* The fixed INIT headers are always in network byte
2389 * order.
2390 */
2391 asoc->peer.i.init_tag =
2392 ntohl(peer_init->init_hdr.init_tag);
2393 asoc->peer.i.a_rwnd =
2394 ntohl(peer_init->init_hdr.a_rwnd);
2395 asoc->peer.i.num_outbound_streams =
2396 ntohs(peer_init->init_hdr.num_outbound_streams);
2397 asoc->peer.i.num_inbound_streams =
2398 ntohs(peer_init->init_hdr.num_inbound_streams);
2399 asoc->peer.i.initial_tsn =
2400 ntohl(peer_init->init_hdr.initial_tsn);
2401
2402 /* Apply the upper bounds for output streams based on peer's
2403 * number of inbound streams.
2404 */
2405 if (asoc->c.sinit_num_ostreams >
2406 ntohs(peer_init->init_hdr.num_inbound_streams)) {
2407 asoc->c.sinit_num_ostreams =
2408 ntohs(peer_init->init_hdr.num_inbound_streams);
2409 }
2410
2411 if (asoc->c.sinit_max_instreams >
2412 ntohs(peer_init->init_hdr.num_outbound_streams)) {
2413 asoc->c.sinit_max_instreams =
2414 ntohs(peer_init->init_hdr.num_outbound_streams);
2415 }
2416
2417 /* Copy Initiation tag from INIT to VT_peer in cookie. */
2418 asoc->c.peer_vtag = asoc->peer.i.init_tag;
2419
2420 /* Peer Rwnd : Current calculated value of the peer's rwnd. */
2421 asoc->peer.rwnd = asoc->peer.i.a_rwnd;
2422
2423 /* Copy cookie in case we need to resend COOKIE-ECHO. */
2424 cookie = asoc->peer.cookie;
2425 if (cookie) {
2426 asoc->peer.cookie = kmemdup(cookie, asoc->peer.cookie_len, gfp);
2427 if (!asoc->peer.cookie)
2428 goto clean_up;
2429 }
2430
2431 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily
2432 * high (for example, implementations MAY use the size of the receiver
2433 * advertised window).
2434 */
2435 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
2436 transports) {
2437 transport->ssthresh = asoc->peer.i.a_rwnd;
2438 }
2439
2440 /* Set up the TSN tracking pieces. */
2441 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
2442 asoc->peer.i.initial_tsn, gfp))
2443 goto clean_up;
2444
2445 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
2446 *
2447 * The stream sequence number in all the streams shall start
2448 * from 0 when the association is established. Also, when the
2449 * stream sequence number reaches the value 65535 the next
2450 * stream sequence number shall be set to 0.
2451 */
2452
2453 /* Allocate storage for the negotiated streams if it is not a temporary
2454 * association.
2455 */
2456 if (!asoc->temp) {
2457 int error;
2458
2459 asoc->ssnmap = sctp_ssnmap_new(asoc->c.sinit_max_instreams,
2460 asoc->c.sinit_num_ostreams, gfp);
2461 if (!asoc->ssnmap)
2462 goto clean_up;
2463
2464 error = sctp_assoc_set_id(asoc, gfp);
2465 if (error)
2466 goto clean_up;
2467 }
2468
2469 /* ADDIP Section 4.1 ASCONF Chunk Procedures
2470 *
2471 * When an endpoint has an ASCONF signaled change to be sent to the
2472 * remote endpoint it should do the following:
2473 * ...
2474 * A2) A serial number should be assigned to the Chunk. The serial
2475 * number should be a monotonically increasing number. All serial
2476 * numbers are defined to be initialized at the start of the
2477 * association to the same value as the Initial TSN.
2478 */
2479 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1;
2480 return 1;
2481
2482clean_up:
2483 /* Release the transport structures. */
2484 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
2485 transport = list_entry(pos, struct sctp_transport, transports);
2486 if (transport->state != SCTP_ACTIVE)
2487 sctp_assoc_rm_peer(asoc, transport);
2488 }
2489
2490nomem:
2491 return 0;
2492}
2493
2494
2495/* Update asoc with the option described in param.
2496 *
2497 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT
2498 *
2499 * asoc is the association to update.
2500 * param is the variable length parameter to use for update.
2501 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO.
2502 * If the current packet is an INIT we want to minimize the amount of
2503 * work we do. In particular, we should not build transport
2504 * structures for the addresses.
2505 */
2506static int sctp_process_param(struct sctp_association *asoc,
2507 union sctp_params param,
2508 const union sctp_addr *peer_addr,
2509 gfp_t gfp)
2510{
2511 struct net *net = sock_net(asoc->base.sk);
2512 union sctp_addr addr;
2513 int i;
2514 __u16 sat;
2515 int retval = 1;
2516 sctp_scope_t scope;
2517 u32 stale;
2518 struct sctp_af *af;
2519 union sctp_addr_param *addr_param;
2520 struct sctp_transport *t;
2521 struct sctp_endpoint *ep = asoc->ep;
2522
2523 /* We maintain all INIT parameters in network byte order all the
2524 * time. This allows us to not worry about whether the parameters
2525 * came from a fresh INIT, and INIT ACK, or were stored in a cookie.
2526 */
2527 switch (param.p->type) {
2528 case SCTP_PARAM_IPV6_ADDRESS:
2529 if (PF_INET6 != asoc->base.sk->sk_family)
2530 break;
2531 goto do_addr_param;
2532
2533 case SCTP_PARAM_IPV4_ADDRESS:
2534 /* v4 addresses are not allowed on v6-only socket */
2535 if (ipv6_only_sock(asoc->base.sk))
2536 break;
2537do_addr_param:
2538 af = sctp_get_af_specific(param_type2af(param.p->type));
2539 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0);
2540 scope = sctp_scope(peer_addr);
2541 if (sctp_in_scope(net, &addr, scope))
2542 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED))
2543 return 0;
2544 break;
2545
2546 case SCTP_PARAM_COOKIE_PRESERVATIVE:
2547 if (!net->sctp.cookie_preserve_enable)
2548 break;
2549
2550 stale = ntohl(param.life->lifespan_increment);
2551
2552 /* Suggested Cookie Life span increment's unit is msec,
2553 * (1/1000sec).
2554 */
2555 asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale);
2556 break;
2557
2558 case SCTP_PARAM_HOST_NAME_ADDRESS:
2559 pr_debug("%s: unimplemented SCTP_HOST_NAME_ADDRESS\n", __func__);
2560 break;
2561
2562 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
2563 /* Turn off the default values first so we'll know which
2564 * ones are really set by the peer.
2565 */
2566 asoc->peer.ipv4_address = 0;
2567 asoc->peer.ipv6_address = 0;
2568
2569 /* Assume that peer supports the address family
2570 * by which it sends a packet.
2571 */
2572 if (peer_addr->sa.sa_family == AF_INET6)
2573 asoc->peer.ipv6_address = 1;
2574 else if (peer_addr->sa.sa_family == AF_INET)
2575 asoc->peer.ipv4_address = 1;
2576
2577 /* Cycle through address types; avoid divide by 0. */
2578 sat = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
2579 if (sat)
2580 sat /= sizeof(__u16);
2581
2582 for (i = 0; i < sat; ++i) {
2583 switch (param.sat->types[i]) {
2584 case SCTP_PARAM_IPV4_ADDRESS:
2585 asoc->peer.ipv4_address = 1;
2586 break;
2587
2588 case SCTP_PARAM_IPV6_ADDRESS:
2589 if (PF_INET6 == asoc->base.sk->sk_family)
2590 asoc->peer.ipv6_address = 1;
2591 break;
2592
2593 case SCTP_PARAM_HOST_NAME_ADDRESS:
2594 asoc->peer.hostname_address = 1;
2595 break;
2596
2597 default: /* Just ignore anything else. */
2598 break;
2599 }
2600 }
2601 break;
2602
2603 case SCTP_PARAM_STATE_COOKIE:
2604 asoc->peer.cookie_len =
2605 ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
2606 asoc->peer.cookie = param.cookie->body;
2607 break;
2608
2609 case SCTP_PARAM_HEARTBEAT_INFO:
2610 /* Would be odd to receive, but it causes no problems. */
2611 break;
2612
2613 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
2614 /* Rejected during verify stage. */
2615 break;
2616
2617 case SCTP_PARAM_ECN_CAPABLE:
2618 asoc->peer.ecn_capable = 1;
2619 break;
2620
2621 case SCTP_PARAM_ADAPTATION_LAYER_IND:
2622 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind);
2623 break;
2624
2625 case SCTP_PARAM_SET_PRIMARY:
2626 if (!net->sctp.addip_enable)
2627 goto fall_through;
2628
2629 addr_param = param.v + sizeof(sctp_addip_param_t);
2630
2631 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
2632 if (af == NULL)
2633 break;
2634
2635 af->from_addr_param(&addr, addr_param,
2636 htons(asoc->peer.port), 0);
2637
2638 /* if the address is invalid, we can't process it.
2639 * XXX: see spec for what to do.
2640 */
2641 if (!af->addr_valid(&addr, NULL, NULL))
2642 break;
2643
2644 t = sctp_assoc_lookup_paddr(asoc, &addr);
2645 if (!t)
2646 break;
2647
2648 sctp_assoc_set_primary(asoc, t);
2649 break;
2650
2651 case SCTP_PARAM_SUPPORTED_EXT:
2652 sctp_process_ext_param(asoc, param);
2653 break;
2654
2655 case SCTP_PARAM_FWD_TSN_SUPPORT:
2656 if (net->sctp.prsctp_enable) {
2657 asoc->peer.prsctp_capable = 1;
2658 break;
2659 }
2660 /* Fall Through */
2661 goto fall_through;
2662
2663 case SCTP_PARAM_RANDOM:
2664 if (!ep->auth_enable)
2665 goto fall_through;
2666
2667 /* Save peer's random parameter */
2668 asoc->peer.peer_random = kmemdup(param.p,
2669 ntohs(param.p->length), gfp);
2670 if (!asoc->peer.peer_random) {
2671 retval = 0;
2672 break;
2673 }
2674 break;
2675
2676 case SCTP_PARAM_HMAC_ALGO:
2677 if (!ep->auth_enable)
2678 goto fall_through;
2679
2680 /* Save peer's HMAC list */
2681 asoc->peer.peer_hmacs = kmemdup(param.p,
2682 ntohs(param.p->length), gfp);
2683 if (!asoc->peer.peer_hmacs) {
2684 retval = 0;
2685 break;
2686 }
2687
2688 /* Set the default HMAC the peer requested*/
2689 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo);
2690 break;
2691
2692 case SCTP_PARAM_CHUNKS:
2693 if (!ep->auth_enable)
2694 goto fall_through;
2695
2696 asoc->peer.peer_chunks = kmemdup(param.p,
2697 ntohs(param.p->length), gfp);
2698 if (!asoc->peer.peer_chunks)
2699 retval = 0;
2700 break;
2701fall_through:
2702 default:
2703 /* Any unrecognized parameters should have been caught
2704 * and handled by sctp_verify_param() which should be
2705 * called prior to this routine. Simply log the error
2706 * here.
2707 */
2708 pr_debug("%s: ignoring param:%d for association:%p.\n",
2709 __func__, ntohs(param.p->type), asoc);
2710 break;
2711 }
2712
2713 return retval;
2714}
2715
2716/* Select a new verification tag. */
2717__u32 sctp_generate_tag(const struct sctp_endpoint *ep)
2718{
2719 /* I believe that this random number generator complies with RFC1750.
2720 * A tag of 0 is reserved for special cases (e.g. INIT).
2721 */
2722 __u32 x;
2723
2724 do {
2725 get_random_bytes(&x, sizeof(__u32));
2726 } while (x == 0);
2727
2728 return x;
2729}
2730
2731/* Select an initial TSN to send during startup. */
2732__u32 sctp_generate_tsn(const struct sctp_endpoint *ep)
2733{
2734 __u32 retval;
2735
2736 get_random_bytes(&retval, sizeof(__u32));
2737 return retval;
2738}
2739
2740/*
2741 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF)
2742 * 0 1 2 3
2743 * 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
2744 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2745 * | Type = 0xC1 | Chunk Flags | Chunk Length |
2746 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2747 * | Serial Number |
2748 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2749 * | Address Parameter |
2750 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2751 * | ASCONF Parameter #1 |
2752 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2753 * \ \
2754 * / .... /
2755 * \ \
2756 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2757 * | ASCONF Parameter #N |
2758 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2759 *
2760 * Address Parameter and other parameter will not be wrapped in this function
2761 */
2762static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc,
2763 union sctp_addr *addr,
2764 int vparam_len)
2765{
2766 sctp_addiphdr_t asconf;
2767 struct sctp_chunk *retval;
2768 int length = sizeof(asconf) + vparam_len;
2769 union sctp_addr_param addrparam;
2770 int addrlen;
2771 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
2772
2773 addrlen = af->to_addr_param(addr, &addrparam);
2774 if (!addrlen)
2775 return NULL;
2776 length += addrlen;
2777
2778 /* Create the chunk. */
2779 retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length,
2780 GFP_ATOMIC);
2781 if (!retval)
2782 return NULL;
2783
2784 asconf.serial = htonl(asoc->addip_serial++);
2785
2786 retval->subh.addip_hdr =
2787 sctp_addto_chunk(retval, sizeof(asconf), &asconf);
2788 retval->param_hdr.v =
2789 sctp_addto_chunk(retval, addrlen, &addrparam);
2790
2791 return retval;
2792}
2793
2794/* ADDIP
2795 * 3.2.1 Add 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 = 0xC001 | Length = Variable |
2800 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2801 * | ASCONF-Request Correlation ID |
2802 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2803 * | Address Parameter |
2804 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2805 *
2806 * 3.2.2 Delete IP Address
2807 * 0 1 2 3
2808 * 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
2809 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2810 * | Type = 0xC002 | Length = Variable |
2811 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2812 * | ASCONF-Request Correlation ID |
2813 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2814 * | Address Parameter |
2815 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2816 *
2817 */
2818struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc,
2819 union sctp_addr *laddr,
2820 struct sockaddr *addrs,
2821 int addrcnt,
2822 __be16 flags)
2823{
2824 sctp_addip_param_t param;
2825 struct sctp_chunk *retval;
2826 union sctp_addr_param addr_param;
2827 union sctp_addr *addr;
2828 void *addr_buf;
2829 struct sctp_af *af;
2830 int paramlen = sizeof(param);
2831 int addr_param_len = 0;
2832 int totallen = 0;
2833 int i;
2834 int del_pickup = 0;
2835
2836 /* Get total length of all the address parameters. */
2837 addr_buf = addrs;
2838 for (i = 0; i < addrcnt; i++) {
2839 addr = addr_buf;
2840 af = sctp_get_af_specific(addr->v4.sin_family);
2841 addr_param_len = af->to_addr_param(addr, &addr_param);
2842
2843 totallen += paramlen;
2844 totallen += addr_param_len;
2845
2846 addr_buf += af->sockaddr_len;
2847 if (asoc->asconf_addr_del_pending && !del_pickup) {
2848 /* reuse the parameter length from the same scope one */
2849 totallen += paramlen;
2850 totallen += addr_param_len;
2851 del_pickup = 1;
2852
2853 pr_debug("%s: picked same-scope del_pending addr, "
2854 "totallen for all addresses is %d\n",
2855 __func__, totallen);
2856 }
2857 }
2858
2859 /* Create an asconf chunk with the required length. */
2860 retval = sctp_make_asconf(asoc, laddr, totallen);
2861 if (!retval)
2862 return NULL;
2863
2864 /* Add the address parameters to the asconf chunk. */
2865 addr_buf = addrs;
2866 for (i = 0; i < addrcnt; i++) {
2867 addr = addr_buf;
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 = flags;
2871 param.param_hdr.length = htons(paramlen + addr_param_len);
2872 param.crr_id = i;
2873
2874 sctp_addto_chunk(retval, paramlen, ¶m);
2875 sctp_addto_chunk(retval, addr_param_len, &addr_param);
2876
2877 addr_buf += af->sockaddr_len;
2878 }
2879 if (flags == SCTP_PARAM_ADD_IP && del_pickup) {
2880 addr = asoc->asconf_addr_del_pending;
2881 af = sctp_get_af_specific(addr->v4.sin_family);
2882 addr_param_len = af->to_addr_param(addr, &addr_param);
2883 param.param_hdr.type = SCTP_PARAM_DEL_IP;
2884 param.param_hdr.length = htons(paramlen + addr_param_len);
2885 param.crr_id = i;
2886
2887 sctp_addto_chunk(retval, paramlen, ¶m);
2888 sctp_addto_chunk(retval, addr_param_len, &addr_param);
2889 }
2890 return retval;
2891}
2892
2893/* ADDIP
2894 * 3.2.4 Set Primary IP Address
2895 * 0 1 2 3
2896 * 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
2897 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2898 * | Type =0xC004 | Length = Variable |
2899 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2900 * | ASCONF-Request Correlation ID |
2901 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2902 * | Address Parameter |
2903 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2904 *
2905 * Create an ASCONF chunk with Set Primary IP address parameter.
2906 */
2907struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
2908 union sctp_addr *addr)
2909{
2910 sctp_addip_param_t param;
2911 struct sctp_chunk *retval;
2912 int len = sizeof(param);
2913 union sctp_addr_param addrparam;
2914 int addrlen;
2915 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
2916
2917 addrlen = af->to_addr_param(addr, &addrparam);
2918 if (!addrlen)
2919 return NULL;
2920 len += addrlen;
2921
2922 /* Create the chunk and make asconf header. */
2923 retval = sctp_make_asconf(asoc, addr, len);
2924 if (!retval)
2925 return NULL;
2926
2927 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY;
2928 param.param_hdr.length = htons(len);
2929 param.crr_id = 0;
2930
2931 sctp_addto_chunk(retval, sizeof(param), ¶m);
2932 sctp_addto_chunk(retval, addrlen, &addrparam);
2933
2934 return retval;
2935}
2936
2937/* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK)
2938 * 0 1 2 3
2939 * 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
2940 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2941 * | Type = 0x80 | Chunk Flags | Chunk Length |
2942 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2943 * | Serial Number |
2944 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2945 * | ASCONF Parameter Response#1 |
2946 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2947 * \ \
2948 * / .... /
2949 * \ \
2950 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2951 * | ASCONF Parameter Response#N |
2952 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2953 *
2954 * Create an ASCONF_ACK chunk with enough space for the parameter responses.
2955 */
2956static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc,
2957 __u32 serial, int vparam_len)
2958{
2959 sctp_addiphdr_t asconf;
2960 struct sctp_chunk *retval;
2961 int length = sizeof(asconf) + vparam_len;
2962
2963 /* Create the chunk. */
2964 retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length,
2965 GFP_ATOMIC);
2966 if (!retval)
2967 return NULL;
2968
2969 asconf.serial = htonl(serial);
2970
2971 retval->subh.addip_hdr =
2972 sctp_addto_chunk(retval, sizeof(asconf), &asconf);
2973
2974 return retval;
2975}
2976
2977/* Add response parameters to an ASCONF_ACK chunk. */
2978static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id,
2979 __be16 err_code, sctp_addip_param_t *asconf_param)
2980{
2981 sctp_addip_param_t ack_param;
2982 sctp_errhdr_t err_param;
2983 int asconf_param_len = 0;
2984 int err_param_len = 0;
2985 __be16 response_type;
2986
2987 if (SCTP_ERROR_NO_ERROR == err_code) {
2988 response_type = SCTP_PARAM_SUCCESS_REPORT;
2989 } else {
2990 response_type = SCTP_PARAM_ERR_CAUSE;
2991 err_param_len = sizeof(err_param);
2992 if (asconf_param)
2993 asconf_param_len =
2994 ntohs(asconf_param->param_hdr.length);
2995 }
2996
2997 /* Add Success Indication or Error Cause Indication parameter. */
2998 ack_param.param_hdr.type = response_type;
2999 ack_param.param_hdr.length = htons(sizeof(ack_param) +
3000 err_param_len +
3001 asconf_param_len);
3002 ack_param.crr_id = crr_id;
3003 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param);
3004
3005 if (SCTP_ERROR_NO_ERROR == err_code)
3006 return;
3007
3008 /* Add Error Cause parameter. */
3009 err_param.cause = err_code;
3010 err_param.length = htons(err_param_len + asconf_param_len);
3011 sctp_addto_chunk(chunk, err_param_len, &err_param);
3012
3013 /* Add the failed TLV copied from ASCONF chunk. */
3014 if (asconf_param)
3015 sctp_addto_chunk(chunk, asconf_param_len, asconf_param);
3016}
3017
3018/* Process a asconf parameter. */
3019static __be16 sctp_process_asconf_param(struct sctp_association *asoc,
3020 struct sctp_chunk *asconf,
3021 sctp_addip_param_t *asconf_param)
3022{
3023 struct sctp_transport *peer;
3024 struct sctp_af *af;
3025 union sctp_addr addr;
3026 union sctp_addr_param *addr_param;
3027
3028 addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t);
3029
3030 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP &&
3031 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP &&
3032 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY)
3033 return SCTP_ERROR_UNKNOWN_PARAM;
3034
3035 switch (addr_param->p.type) {
3036 case SCTP_PARAM_IPV6_ADDRESS:
3037 if (!asoc->peer.ipv6_address)
3038 return SCTP_ERROR_DNS_FAILED;
3039 break;
3040 case SCTP_PARAM_IPV4_ADDRESS:
3041 if (!asoc->peer.ipv4_address)
3042 return SCTP_ERROR_DNS_FAILED;
3043 break;
3044 default:
3045 return SCTP_ERROR_DNS_FAILED;
3046 }
3047
3048 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
3049 if (unlikely(!af))
3050 return SCTP_ERROR_DNS_FAILED;
3051
3052 af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0);
3053
3054 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast
3055 * or multicast address.
3056 * (note: wildcard is permitted and requires special handling so
3057 * make sure we check for that)
3058 */
3059 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb))
3060 return SCTP_ERROR_DNS_FAILED;
3061
3062 switch (asconf_param->param_hdr.type) {
3063 case SCTP_PARAM_ADD_IP:
3064 /* Section 4.2.1:
3065 * If the address 0.0.0.0 or ::0 is provided, the source
3066 * address of the packet MUST be added.
3067 */
3068 if (af->is_any(&addr))
3069 memcpy(&addr, &asconf->source, sizeof(addr));
3070
3071 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address
3072 * request and does not have the local resources to add this
3073 * new address to the association, it MUST return an Error
3074 * Cause TLV set to the new error code 'Operation Refused
3075 * Due to Resource Shortage'.
3076 */
3077
3078 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED);
3079 if (!peer)
3080 return SCTP_ERROR_RSRC_LOW;
3081
3082 /* Start the heartbeat timer. */
3083 sctp_transport_reset_hb_timer(peer);
3084 asoc->new_transport = peer;
3085 break;
3086 case SCTP_PARAM_DEL_IP:
3087 /* ADDIP 4.3 D7) If a request is received to delete the
3088 * last remaining IP address of a peer endpoint, the receiver
3089 * MUST send an Error Cause TLV with the error cause set to the
3090 * new error code 'Request to Delete Last Remaining IP Address'.
3091 */
3092 if (asoc->peer.transport_count == 1)
3093 return SCTP_ERROR_DEL_LAST_IP;
3094
3095 /* ADDIP 4.3 D8) If a request is received to delete an IP
3096 * address which is also the source address of the IP packet
3097 * which contained the ASCONF chunk, the receiver MUST reject
3098 * this request. To reject the request the receiver MUST send
3099 * an Error Cause TLV set to the new error code 'Request to
3100 * Delete Source IP Address'
3101 */
3102 if (sctp_cmp_addr_exact(&asconf->source, &addr))
3103 return SCTP_ERROR_DEL_SRC_IP;
3104
3105 /* Section 4.2.2
3106 * If the address 0.0.0.0 or ::0 is provided, all
3107 * addresses of the peer except the source address of the
3108 * packet MUST be deleted.
3109 */
3110 if (af->is_any(&addr)) {
3111 sctp_assoc_set_primary(asoc, asconf->transport);
3112 sctp_assoc_del_nonprimary_peers(asoc,
3113 asconf->transport);
3114 return SCTP_ERROR_NO_ERROR;
3115 }
3116
3117 /* If the address is not part of the association, the
3118 * ASCONF-ACK with Error Cause Indication Parameter
3119 * which including cause of Unresolvable Address should
3120 * be sent.
3121 */
3122 peer = sctp_assoc_lookup_paddr(asoc, &addr);
3123 if (!peer)
3124 return SCTP_ERROR_DNS_FAILED;
3125
3126 sctp_assoc_rm_peer(asoc, peer);
3127 break;
3128 case SCTP_PARAM_SET_PRIMARY:
3129 /* ADDIP Section 4.2.4
3130 * If the address 0.0.0.0 or ::0 is provided, the receiver
3131 * MAY mark the source address of the packet as its
3132 * primary.
3133 */
3134 if (af->is_any(&addr))
3135 memcpy(&addr.v4, sctp_source(asconf), sizeof(addr));
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 sctp_addip_chunk_t *addip = (sctp_addip_chunk_t *) chunk->chunk_hdr;
3154 union sctp_params param;
3155 bool addr_param_seen = false;
3156
3157 sctp_walk_params(param, addip, addip_hdr.params) {
3158 size_t length = ntohs(param.p->length);
3159
3160 *errp = param.p;
3161 switch (param.p->type) {
3162 case SCTP_PARAM_ERR_CAUSE:
3163 break;
3164 case SCTP_PARAM_IPV4_ADDRESS:
3165 if (length != sizeof(sctp_ipv4addr_param_t))
3166 return false;
3167 /* ensure there is only one addr param and it's in the
3168 * beginning of addip_hdr params, or we reject it.
3169 */
3170 if (param.v != addip->addip_hdr.params)
3171 return false;
3172 addr_param_seen = true;
3173 break;
3174 case SCTP_PARAM_IPV6_ADDRESS:
3175 if (length != sizeof(sctp_ipv6addr_param_t))
3176 return false;
3177 if (param.v != addip->addip_hdr.params)
3178 return false;
3179 addr_param_seen = true;
3180 break;
3181 case SCTP_PARAM_ADD_IP:
3182 case SCTP_PARAM_DEL_IP:
3183 case SCTP_PARAM_SET_PRIMARY:
3184 /* In ASCONF chunks, these need to be first. */
3185 if (addr_param_needed && !addr_param_seen)
3186 return false;
3187 length = ntohs(param.addip->param_hdr.length);
3188 if (length < sizeof(sctp_addip_param_t) +
3189 sizeof(sctp_paramhdr_t))
3190 return false;
3191 break;
3192 case SCTP_PARAM_SUCCESS_REPORT:
3193 case SCTP_PARAM_ADAPTATION_LAYER_IND:
3194 if (length != sizeof(sctp_addip_param_t))
3195 return false;
3196 break;
3197 default:
3198 /* This is unkown to us, reject! */
3199 return false;
3200 }
3201 }
3202
3203 /* Remaining sanity checks. */
3204 if (addr_param_needed && !addr_param_seen)
3205 return false;
3206 if (!addr_param_needed && addr_param_seen)
3207 return false;
3208 if (param.v != chunk->chunk_end)
3209 return false;
3210
3211 return true;
3212}
3213
3214/* Process an incoming ASCONF chunk with the next expected serial no. and
3215 * return an ASCONF_ACK chunk to be sent in response.
3216 */
3217struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
3218 struct sctp_chunk *asconf)
3219{
3220 sctp_addip_chunk_t *addip = (sctp_addip_chunk_t *) asconf->chunk_hdr;
3221 bool all_param_pass = true;
3222 union sctp_params param;
3223 sctp_addiphdr_t *hdr;
3224 union sctp_addr_param *addr_param;
3225 sctp_addip_param_t *asconf_param;
3226 struct sctp_chunk *asconf_ack;
3227 __be16 err_code;
3228 int length = 0;
3229 int chunk_len;
3230 __u32 serial;
3231
3232 chunk_len = ntohs(asconf->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
3233 hdr = (sctp_addiphdr_t *)asconf->skb->data;
3234 serial = ntohl(hdr->serial);
3235
3236 /* Skip the addiphdr and store a pointer to address parameter. */
3237 length = sizeof(sctp_addiphdr_t);
3238 addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
3239 chunk_len -= length;
3240
3241 /* Skip the address parameter and store a pointer to the first
3242 * asconf parameter.
3243 */
3244 length = ntohs(addr_param->p.length);
3245 asconf_param = (void *)addr_param + 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 sctp_addip_param_t *asconf_param)
3305{
3306 struct sctp_af *af;
3307 union sctp_addr addr;
3308 struct sctp_bind_addr *bp = &asoc->base.bind_addr;
3309 union sctp_addr_param *addr_param;
3310 struct sctp_transport *transport;
3311 struct sctp_sockaddr_entry *saddr;
3312
3313 addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t);
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 dst_release(transport->dst);
3333 transport->dst = NULL;
3334 }
3335 break;
3336 case SCTP_PARAM_DEL_IP:
3337 local_bh_disable();
3338 sctp_del_bind_addr(bp, &addr);
3339 if (asoc->asconf_addr_del_pending != NULL &&
3340 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) {
3341 kfree(asoc->asconf_addr_del_pending);
3342 asoc->asconf_addr_del_pending = NULL;
3343 }
3344 local_bh_enable();
3345 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
3346 transports) {
3347 dst_release(transport->dst);
3348 transport->dst = NULL;
3349 }
3350 break;
3351 default:
3352 break;
3353 }
3354}
3355
3356/* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk
3357 * for the given asconf parameter. If there is no response for this parameter,
3358 * return the error code based on the third argument 'no_err'.
3359 * ADDIP 4.1
3360 * A7) If an error response is received for a TLV parameter, all TLVs with no
3361 * response before the failed TLV are considered successful if not reported.
3362 * All TLVs after the failed response are considered unsuccessful unless a
3363 * specific success indication is present for the parameter.
3364 */
3365static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack,
3366 sctp_addip_param_t *asconf_param,
3367 int no_err)
3368{
3369 sctp_addip_param_t *asconf_ack_param;
3370 sctp_errhdr_t *err_param;
3371 int length;
3372 int asconf_ack_len;
3373 __be16 err_code;
3374
3375 if (no_err)
3376 err_code = SCTP_ERROR_NO_ERROR;
3377 else
3378 err_code = SCTP_ERROR_REQ_REFUSED;
3379
3380 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) -
3381 sizeof(sctp_chunkhdr_t);
3382
3383 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to
3384 * the first asconf_ack parameter.
3385 */
3386 length = sizeof(sctp_addiphdr_t);
3387 asconf_ack_param = (sctp_addip_param_t *)(asconf_ack->skb->data +
3388 length);
3389 asconf_ack_len -= length;
3390
3391 while (asconf_ack_len > 0) {
3392 if (asconf_ack_param->crr_id == asconf_param->crr_id) {
3393 switch (asconf_ack_param->param_hdr.type) {
3394 case SCTP_PARAM_SUCCESS_REPORT:
3395 return SCTP_ERROR_NO_ERROR;
3396 case SCTP_PARAM_ERR_CAUSE:
3397 length = sizeof(sctp_addip_param_t);
3398 err_param = (void *)asconf_ack_param + length;
3399 asconf_ack_len -= length;
3400 if (asconf_ack_len > 0)
3401 return err_param->cause;
3402 else
3403 return SCTP_ERROR_INV_PARAM;
3404 break;
3405 default:
3406 return SCTP_ERROR_INV_PARAM;
3407 }
3408 }
3409
3410 length = ntohs(asconf_ack_param->param_hdr.length);
3411 asconf_ack_param = (void *)asconf_ack_param + length;
3412 asconf_ack_len -= length;
3413 }
3414
3415 return err_code;
3416}
3417
3418/* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */
3419int sctp_process_asconf_ack(struct sctp_association *asoc,
3420 struct sctp_chunk *asconf_ack)
3421{
3422 struct sctp_chunk *asconf = asoc->addip_last_asconf;
3423 union sctp_addr_param *addr_param;
3424 sctp_addip_param_t *asconf_param;
3425 int length = 0;
3426 int asconf_len = asconf->skb->len;
3427 int all_param_pass = 0;
3428 int no_err = 1;
3429 int retval = 0;
3430 __be16 err_code = SCTP_ERROR_NO_ERROR;
3431
3432 /* Skip the chunkhdr and addiphdr from the last asconf sent and store
3433 * a pointer to address parameter.
3434 */
3435 length = sizeof(sctp_addip_chunk_t);
3436 addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
3437 asconf_len -= length;
3438
3439 /* Skip the address parameter in the last asconf sent and store a
3440 * pointer to the first asconf parameter.
3441 */
3442 length = ntohs(addr_param->p.length);
3443 asconf_param = (void *)addr_param + length;
3444 asconf_len -= length;
3445
3446 /* ADDIP 4.1
3447 * A8) If there is no response(s) to specific TLV parameter(s), and no
3448 * failures are indicated, then all request(s) are considered
3449 * successful.
3450 */
3451 if (asconf_ack->skb->len == sizeof(sctp_addiphdr_t))
3452 all_param_pass = 1;
3453
3454 /* Process the TLVs contained in the last sent ASCONF chunk. */
3455 while (asconf_len > 0) {
3456 if (all_param_pass)
3457 err_code = SCTP_ERROR_NO_ERROR;
3458 else {
3459 err_code = sctp_get_asconf_response(asconf_ack,
3460 asconf_param,
3461 no_err);
3462 if (no_err && (SCTP_ERROR_NO_ERROR != err_code))
3463 no_err = 0;
3464 }
3465
3466 switch (err_code) {
3467 case SCTP_ERROR_NO_ERROR:
3468 sctp_asconf_param_success(asoc, asconf_param);
3469 break;
3470
3471 case SCTP_ERROR_RSRC_LOW:
3472 retval = 1;
3473 break;
3474
3475 case SCTP_ERROR_UNKNOWN_PARAM:
3476 /* Disable sending this type of asconf parameter in
3477 * future.
3478 */
3479 asoc->peer.addip_disabled_mask |=
3480 asconf_param->param_hdr.type;
3481 break;
3482
3483 case SCTP_ERROR_REQ_REFUSED:
3484 case SCTP_ERROR_DEL_LAST_IP:
3485 case SCTP_ERROR_DEL_SRC_IP:
3486 default:
3487 break;
3488 }
3489
3490 /* Skip the processed asconf parameter and move to the next
3491 * one.
3492 */
3493 length = ntohs(asconf_param->param_hdr.length);
3494 asconf_param = (void *)asconf_param + length;
3495 asconf_len -= length;
3496 }
3497
3498 if (no_err && asoc->src_out_of_asoc_ok) {
3499 asoc->src_out_of_asoc_ok = 0;
3500 sctp_transport_immediate_rtx(asoc->peer.primary_path);
3501 }
3502
3503 /* Free the cached last sent asconf chunk. */
3504 list_del_init(&asconf->transmitted_list);
3505 sctp_chunk_free(asconf);
3506 asoc->addip_last_asconf = NULL;
3507
3508 return retval;
3509}
3510
3511/* Make a FWD TSN chunk. */
3512struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
3513 __u32 new_cum_tsn, size_t nstreams,
3514 struct sctp_fwdtsn_skip *skiplist)
3515{
3516 struct sctp_chunk *retval = NULL;
3517 struct sctp_fwdtsn_hdr ftsn_hdr;
3518 struct sctp_fwdtsn_skip skip;
3519 size_t hint;
3520 int i;
3521
3522 hint = (nstreams + 1) * sizeof(__u32);
3523
3524 retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint, GFP_ATOMIC);
3525
3526 if (!retval)
3527 return NULL;
3528
3529 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn);
3530 retval->subh.fwdtsn_hdr =
3531 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr);
3532
3533 for (i = 0; i < nstreams; i++) {
3534 skip.stream = skiplist[i].stream;
3535 skip.ssn = skiplist[i].ssn;
3536 sctp_addto_chunk(retval, sizeof(skip), &skip);
3537 }
3538
3539 return retval;
3540}