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1// SPDX-License-Identifier: GPL-2.0-or-later
2/* SCTP kernel implementation
3 * (C) Copyright IBM Corp. 2001, 2004
4 * Copyright (c) 1999-2000 Cisco, Inc.
5 * Copyright (c) 1999-2001 Motorola, Inc.
6 * Copyright (c) 2001-2002 Intel Corp.
7 *
8 * This file is part of the SCTP kernel implementation
9 *
10 * These functions work with the state functions in sctp_sm_statefuns.c
11 * to implement the state operations. These functions implement the
12 * steps which require modifying existing data structures.
13 *
14 * Please send any bug reports or fixes you make to the
15 * email address(es):
16 * lksctp developers <linux-sctp@vger.kernel.org>
17 *
18 * Written or modified by:
19 * La Monte H.P. Yarroll <piggy@acm.org>
20 * Karl Knutson <karl@athena.chicago.il.us>
21 * C. Robin <chris@hundredacre.ac.uk>
22 * Jon Grimm <jgrimm@us.ibm.com>
23 * Xingang Guo <xingang.guo@intel.com>
24 * Dajiang Zhang <dajiang.zhang@nokia.com>
25 * Sridhar Samudrala <sri@us.ibm.com>
26 * Daisy Chang <daisyc@us.ibm.com>
27 * Ardelle Fan <ardelle.fan@intel.com>
28 * Kevin Gao <kevin.gao@intel.com>
29 */
30
31#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
32
33#include <crypto/hash.h>
34#include <linux/types.h>
35#include <linux/kernel.h>
36#include <linux/ip.h>
37#include <linux/ipv6.h>
38#include <linux/net.h>
39#include <linux/inet.h>
40#include <linux/scatterlist.h>
41#include <linux/slab.h>
42#include <net/sock.h>
43
44#include <linux/skbuff.h>
45#include <linux/random.h> /* for get_random_bytes */
46#include <net/sctp/sctp.h>
47#include <net/sctp/sm.h>
48
49static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc,
50 __u8 type, __u8 flags, int paylen,
51 gfp_t gfp);
52static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc,
53 __u8 flags, int paylen, gfp_t gfp);
54static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc,
55 __u8 type, __u8 flags, int paylen,
56 gfp_t gfp);
57static struct sctp_cookie_param *sctp_pack_cookie(
58 const struct sctp_endpoint *ep,
59 const struct sctp_association *asoc,
60 const struct sctp_chunk *init_chunk,
61 int *cookie_len,
62 const __u8 *raw_addrs, int addrs_len);
63static int sctp_process_param(struct sctp_association *asoc,
64 union sctp_params param,
65 const union sctp_addr *peer_addr,
66 gfp_t gfp);
67static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
68 const void *data);
69
70/* Control chunk destructor */
71static void sctp_control_release_owner(struct sk_buff *skb)
72{
73 struct sctp_chunk *chunk = skb_shinfo(skb)->destructor_arg;
74
75 if (chunk->shkey) {
76 struct sctp_shared_key *shkey = chunk->shkey;
77 struct sctp_association *asoc = chunk->asoc;
78
79 /* refcnt == 2 and !list_empty mean after this release, it's
80 * not being used anywhere, and it's time to notify userland
81 * that this shkey can be freed if it's been deactivated.
82 */
83 if (shkey->deactivated && !list_empty(&shkey->key_list) &&
84 refcount_read(&shkey->refcnt) == 2) {
85 struct sctp_ulpevent *ev;
86
87 ev = sctp_ulpevent_make_authkey(asoc, shkey->key_id,
88 SCTP_AUTH_FREE_KEY,
89 GFP_KERNEL);
90 if (ev)
91 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
92 }
93 sctp_auth_shkey_release(chunk->shkey);
94 }
95}
96
97static void sctp_control_set_owner_w(struct sctp_chunk *chunk)
98{
99 struct sctp_association *asoc = chunk->asoc;
100 struct sk_buff *skb = chunk->skb;
101
102 /* TODO: properly account for control chunks.
103 * To do it right we'll need:
104 * 1) endpoint if association isn't known.
105 * 2) proper memory accounting.
106 *
107 * For now don't do anything for now.
108 */
109 if (chunk->auth) {
110 chunk->shkey = asoc->shkey;
111 sctp_auth_shkey_hold(chunk->shkey);
112 }
113 skb->sk = asoc ? asoc->base.sk : NULL;
114 skb_shinfo(skb)->destructor_arg = chunk;
115 skb->destructor = sctp_control_release_owner;
116}
117
118/* What was the inbound interface for this chunk? */
119int sctp_chunk_iif(const struct sctp_chunk *chunk)
120{
121 struct sk_buff *skb = chunk->skb;
122
123 return SCTP_INPUT_CB(skb)->af->skb_iif(skb);
124}
125
126/* RFC 2960 3.3.2 Initiation (INIT) (1)
127 *
128 * Note 2: The ECN capable field is reserved for future use of
129 * Explicit Congestion Notification.
130 */
131static const struct sctp_paramhdr ecap_param = {
132 SCTP_PARAM_ECN_CAPABLE,
133 cpu_to_be16(sizeof(struct sctp_paramhdr)),
134};
135static const struct sctp_paramhdr prsctp_param = {
136 SCTP_PARAM_FWD_TSN_SUPPORT,
137 cpu_to_be16(sizeof(struct sctp_paramhdr)),
138};
139
140/* A helper to initialize an op error inside a provided chunk, as most
141 * cause codes will be embedded inside an abort chunk.
142 */
143int sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code,
144 size_t paylen)
145{
146 struct sctp_errhdr err;
147 __u16 len;
148
149 /* Cause code constants are now defined in network order. */
150 err.cause = cause_code;
151 len = sizeof(err) + paylen;
152 err.length = htons(len);
153
154 if (skb_tailroom(chunk->skb) < len)
155 return -ENOSPC;
156
157 chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(err), &err);
158
159 return 0;
160}
161
162/* 3.3.2 Initiation (INIT) (1)
163 *
164 * This chunk is used to initiate a SCTP association between two
165 * endpoints. The format of the INIT chunk is shown below:
166 *
167 * 0 1 2 3
168 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
169 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
170 * | Type = 1 | Chunk Flags | Chunk Length |
171 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
172 * | Initiate Tag |
173 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
174 * | Advertised Receiver Window Credit (a_rwnd) |
175 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
176 * | Number of Outbound Streams | Number of Inbound Streams |
177 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
178 * | Initial TSN |
179 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
180 * \ \
181 * / Optional/Variable-Length Parameters /
182 * \ \
183 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
184 *
185 *
186 * The INIT chunk contains the following parameters. Unless otherwise
187 * noted, each parameter MUST only be included once in the INIT chunk.
188 *
189 * Fixed Parameters Status
190 * ----------------------------------------------
191 * Initiate Tag Mandatory
192 * Advertised Receiver Window Credit Mandatory
193 * Number of Outbound Streams Mandatory
194 * Number of Inbound Streams Mandatory
195 * Initial TSN Mandatory
196 *
197 * Variable Parameters Status Type Value
198 * -------------------------------------------------------------
199 * IPv4 Address (Note 1) Optional 5
200 * IPv6 Address (Note 1) Optional 6
201 * Cookie Preservative Optional 9
202 * Reserved for ECN Capable (Note 2) Optional 32768 (0x8000)
203 * Host Name Address (Note 3) Optional 11
204 * Supported Address Types (Note 4) Optional 12
205 */
206struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc,
207 const struct sctp_bind_addr *bp,
208 gfp_t gfp, int vparam_len)
209{
210 struct sctp_supported_ext_param ext_param;
211 struct sctp_adaptation_ind_param aiparam;
212 struct sctp_paramhdr *auth_chunks = NULL;
213 struct sctp_paramhdr *auth_hmacs = NULL;
214 struct sctp_supported_addrs_param sat;
215 struct sctp_endpoint *ep = asoc->ep;
216 struct sctp_chunk *retval = NULL;
217 int num_types, addrs_len = 0;
218 struct sctp_inithdr init;
219 union sctp_params addrs;
220 struct sctp_sock *sp;
221 __u8 extensions[5];
222 size_t chunksize;
223 __be16 types[2];
224 int num_ext = 0;
225
226 /* RFC 2960 3.3.2 Initiation (INIT) (1)
227 *
228 * Note 1: The INIT chunks can contain multiple addresses that
229 * can be IPv4 and/or IPv6 in any combination.
230 */
231
232 /* Convert the provided bind address list to raw format. */
233 addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp);
234
235 init.init_tag = htonl(asoc->c.my_vtag);
236 init.a_rwnd = htonl(asoc->rwnd);
237 init.num_outbound_streams = htons(asoc->c.sinit_num_ostreams);
238 init.num_inbound_streams = htons(asoc->c.sinit_max_instreams);
239 init.initial_tsn = htonl(asoc->c.initial_tsn);
240
241 /* How many address types are needed? */
242 sp = sctp_sk(asoc->base.sk);
243 num_types = sp->pf->supported_addrs(sp, types);
244
245 chunksize = sizeof(init) + addrs_len;
246 chunksize += SCTP_PAD4(SCTP_SAT_LEN(num_types));
247
248 if (asoc->ep->ecn_enable)
249 chunksize += sizeof(ecap_param);
250
251 if (asoc->ep->prsctp_enable)
252 chunksize += sizeof(prsctp_param);
253
254 /* ADDIP: Section 4.2.7:
255 * An implementation supporting this extension [ADDIP] MUST list
256 * the ASCONF,the ASCONF-ACK, and the AUTH chunks in its INIT and
257 * INIT-ACK parameters.
258 */
259 if (asoc->ep->asconf_enable) {
260 extensions[num_ext] = SCTP_CID_ASCONF;
261 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
262 num_ext += 2;
263 }
264
265 if (asoc->ep->reconf_enable) {
266 extensions[num_ext] = SCTP_CID_RECONF;
267 num_ext += 1;
268 }
269
270 if (sp->adaptation_ind)
271 chunksize += sizeof(aiparam);
272
273 if (asoc->ep->intl_enable) {
274 extensions[num_ext] = SCTP_CID_I_DATA;
275 num_ext += 1;
276 }
277
278 chunksize += vparam_len;
279
280 /* Account for AUTH related parameters */
281 if (ep->auth_enable) {
282 /* Add random parameter length*/
283 chunksize += sizeof(asoc->c.auth_random);
284
285 /* Add HMACS parameter length if any were defined */
286 auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs;
287 if (auth_hmacs->length)
288 chunksize += SCTP_PAD4(ntohs(auth_hmacs->length));
289 else
290 auth_hmacs = NULL;
291
292 /* Add CHUNKS parameter length */
293 auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks;
294 if (auth_chunks->length)
295 chunksize += SCTP_PAD4(ntohs(auth_chunks->length));
296 else
297 auth_chunks = NULL;
298
299 extensions[num_ext] = SCTP_CID_AUTH;
300 num_ext += 1;
301 }
302
303 /* If we have any extensions to report, account for that */
304 if (num_ext)
305 chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext);
306
307 /* RFC 2960 3.3.2 Initiation (INIT) (1)
308 *
309 * Note 3: An INIT chunk MUST NOT contain more than one Host
310 * Name address parameter. Moreover, the sender of the INIT
311 * MUST NOT combine any other address types with the Host Name
312 * address in the INIT. The receiver of INIT MUST ignore any
313 * other address types if the Host Name address parameter is
314 * present in the received INIT chunk.
315 *
316 * PLEASE DO NOT FIXME [This version does not support Host Name.]
317 */
318
319 retval = sctp_make_control(asoc, SCTP_CID_INIT, 0, chunksize, gfp);
320 if (!retval)
321 goto nodata;
322
323 retval->subh.init_hdr =
324 sctp_addto_chunk(retval, sizeof(init), &init);
325 retval->param_hdr.v =
326 sctp_addto_chunk(retval, addrs_len, addrs.v);
327
328 /* RFC 2960 3.3.2 Initiation (INIT) (1)
329 *
330 * Note 4: This parameter, when present, specifies all the
331 * address types the sending endpoint can support. The absence
332 * of this parameter indicates that the sending endpoint can
333 * support any address type.
334 */
335 sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES;
336 sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types));
337 sctp_addto_chunk(retval, sizeof(sat), &sat);
338 sctp_addto_chunk(retval, num_types * sizeof(__u16), &types);
339
340 if (asoc->ep->ecn_enable)
341 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
342
343 /* Add the supported extensions parameter. Be nice and add this
344 * fist before addiding the parameters for the extensions themselves
345 */
346 if (num_ext) {
347 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
348 ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext);
349 sctp_addto_chunk(retval, sizeof(ext_param), &ext_param);
350 sctp_addto_param(retval, num_ext, extensions);
351 }
352
353 if (asoc->ep->prsctp_enable)
354 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
355
356 if (sp->adaptation_ind) {
357 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
358 aiparam.param_hdr.length = htons(sizeof(aiparam));
359 aiparam.adaptation_ind = htonl(sp->adaptation_ind);
360 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
361 }
362
363 /* Add SCTP-AUTH chunks to the parameter list */
364 if (ep->auth_enable) {
365 sctp_addto_chunk(retval, sizeof(asoc->c.auth_random),
366 asoc->c.auth_random);
367 if (auth_hmacs)
368 sctp_addto_chunk(retval, ntohs(auth_hmacs->length),
369 auth_hmacs);
370 if (auth_chunks)
371 sctp_addto_chunk(retval, ntohs(auth_chunks->length),
372 auth_chunks);
373 }
374nodata:
375 kfree(addrs.v);
376 return retval;
377}
378
379struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc,
380 const struct sctp_chunk *chunk,
381 gfp_t gfp, int unkparam_len)
382{
383 struct sctp_supported_ext_param ext_param;
384 struct sctp_adaptation_ind_param aiparam;
385 struct sctp_paramhdr *auth_chunks = NULL;
386 struct sctp_paramhdr *auth_random = NULL;
387 struct sctp_paramhdr *auth_hmacs = NULL;
388 struct sctp_chunk *retval = NULL;
389 struct sctp_cookie_param *cookie;
390 struct sctp_inithdr initack;
391 union sctp_params addrs;
392 struct sctp_sock *sp;
393 __u8 extensions[5];
394 size_t chunksize;
395 int num_ext = 0;
396 int cookie_len;
397 int addrs_len;
398
399 /* Note: there may be no addresses to embed. */
400 addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp);
401
402 initack.init_tag = htonl(asoc->c.my_vtag);
403 initack.a_rwnd = htonl(asoc->rwnd);
404 initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams);
405 initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams);
406 initack.initial_tsn = htonl(asoc->c.initial_tsn);
407
408 /* FIXME: We really ought to build the cookie right
409 * into the packet instead of allocating more fresh memory.
410 */
411 cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len,
412 addrs.v, addrs_len);
413 if (!cookie)
414 goto nomem_cookie;
415
416 /* Calculate the total size of allocation, include the reserved
417 * space for reporting unknown parameters if it is specified.
418 */
419 sp = sctp_sk(asoc->base.sk);
420 chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len;
421
422 /* Tell peer that we'll do ECN only if peer advertised such cap. */
423 if (asoc->peer.ecn_capable)
424 chunksize += sizeof(ecap_param);
425
426 if (asoc->peer.prsctp_capable)
427 chunksize += sizeof(prsctp_param);
428
429 if (asoc->peer.asconf_capable) {
430 extensions[num_ext] = SCTP_CID_ASCONF;
431 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
432 num_ext += 2;
433 }
434
435 if (asoc->peer.reconf_capable) {
436 extensions[num_ext] = SCTP_CID_RECONF;
437 num_ext += 1;
438 }
439
440 if (sp->adaptation_ind)
441 chunksize += sizeof(aiparam);
442
443 if (asoc->peer.intl_capable) {
444 extensions[num_ext] = SCTP_CID_I_DATA;
445 num_ext += 1;
446 }
447
448 if (asoc->peer.auth_capable) {
449 auth_random = (struct sctp_paramhdr *)asoc->c.auth_random;
450 chunksize += ntohs(auth_random->length);
451
452 auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs;
453 if (auth_hmacs->length)
454 chunksize += SCTP_PAD4(ntohs(auth_hmacs->length));
455 else
456 auth_hmacs = NULL;
457
458 auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks;
459 if (auth_chunks->length)
460 chunksize += SCTP_PAD4(ntohs(auth_chunks->length));
461 else
462 auth_chunks = NULL;
463
464 extensions[num_ext] = SCTP_CID_AUTH;
465 num_ext += 1;
466 }
467
468 if (num_ext)
469 chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext);
470
471 /* Now allocate and fill out the chunk. */
472 retval = sctp_make_control(asoc, SCTP_CID_INIT_ACK, 0, chunksize, gfp);
473 if (!retval)
474 goto nomem_chunk;
475
476 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
477 *
478 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
479 * HEARTBEAT ACK, * etc.) to the same destination transport
480 * address from which it received the DATA or control chunk
481 * to which it is replying.
482 *
483 * [INIT ACK back to where the INIT came from.]
484 */
485 if (chunk->transport)
486 retval->transport =
487 sctp_assoc_lookup_paddr(asoc,
488 &chunk->transport->ipaddr);
489
490 retval->subh.init_hdr =
491 sctp_addto_chunk(retval, sizeof(initack), &initack);
492 retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v);
493 sctp_addto_chunk(retval, cookie_len, cookie);
494 if (asoc->peer.ecn_capable)
495 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
496 if (num_ext) {
497 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
498 ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext);
499 sctp_addto_chunk(retval, sizeof(ext_param), &ext_param);
500 sctp_addto_param(retval, num_ext, extensions);
501 }
502 if (asoc->peer.prsctp_capable)
503 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
504
505 if (sp->adaptation_ind) {
506 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
507 aiparam.param_hdr.length = htons(sizeof(aiparam));
508 aiparam.adaptation_ind = htonl(sp->adaptation_ind);
509 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
510 }
511
512 if (asoc->peer.auth_capable) {
513 sctp_addto_chunk(retval, ntohs(auth_random->length),
514 auth_random);
515 if (auth_hmacs)
516 sctp_addto_chunk(retval, ntohs(auth_hmacs->length),
517 auth_hmacs);
518 if (auth_chunks)
519 sctp_addto_chunk(retval, ntohs(auth_chunks->length),
520 auth_chunks);
521 }
522
523 /* We need to remove the const qualifier at this point. */
524 retval->asoc = (struct sctp_association *) asoc;
525
526nomem_chunk:
527 kfree(cookie);
528nomem_cookie:
529 kfree(addrs.v);
530 return retval;
531}
532
533/* 3.3.11 Cookie Echo (COOKIE ECHO) (10):
534 *
535 * This chunk is used only during the initialization of an association.
536 * It is sent by the initiator of an association to its peer to complete
537 * the initialization process. This chunk MUST precede any DATA chunk
538 * sent within the association, but MAY be bundled with one or more DATA
539 * chunks in the same packet.
540 *
541 * 0 1 2 3
542 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
543 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
544 * | Type = 10 |Chunk Flags | Length |
545 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
546 * / Cookie /
547 * \ \
548 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
549 *
550 * Chunk Flags: 8 bit
551 *
552 * Set to zero on transmit and ignored on receipt.
553 *
554 * Length: 16 bits (unsigned integer)
555 *
556 * Set to the size of the chunk in bytes, including the 4 bytes of
557 * the chunk header and the size of the Cookie.
558 *
559 * Cookie: variable size
560 *
561 * This field must contain the exact cookie received in the
562 * State Cookie parameter from the previous INIT ACK.
563 *
564 * An implementation SHOULD make the cookie as small as possible
565 * to insure interoperability.
566 */
567struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc,
568 const struct sctp_chunk *chunk)
569{
570 struct sctp_chunk *retval;
571 int cookie_len;
572 void *cookie;
573
574 cookie = asoc->peer.cookie;
575 cookie_len = asoc->peer.cookie_len;
576
577 /* Build a cookie echo chunk. */
578 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ECHO, 0,
579 cookie_len, GFP_ATOMIC);
580 if (!retval)
581 goto nodata;
582 retval->subh.cookie_hdr =
583 sctp_addto_chunk(retval, cookie_len, cookie);
584
585 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
586 *
587 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
588 * HEARTBEAT ACK, * etc.) to the same destination transport
589 * address from which it * received the DATA or control chunk
590 * to which it is replying.
591 *
592 * [COOKIE ECHO back to where the INIT ACK came from.]
593 */
594 if (chunk)
595 retval->transport = chunk->transport;
596
597nodata:
598 return retval;
599}
600
601/* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11):
602 *
603 * This chunk is used only during the initialization of an
604 * association. It is used to acknowledge the receipt of a COOKIE
605 * ECHO chunk. This chunk MUST precede any DATA or SACK chunk sent
606 * within the association, but MAY be bundled with one or more DATA
607 * chunks or SACK chunk in the same SCTP packet.
608 *
609 * 0 1 2 3
610 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
611 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
612 * | Type = 11 |Chunk Flags | Length = 4 |
613 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
614 *
615 * Chunk Flags: 8 bits
616 *
617 * Set to zero on transmit and ignored on receipt.
618 */
619struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc,
620 const struct sctp_chunk *chunk)
621{
622 struct sctp_chunk *retval;
623
624 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ACK, 0, 0, GFP_ATOMIC);
625
626 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
627 *
628 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
629 * HEARTBEAT ACK, * etc.) to the same destination transport
630 * address from which it * received the DATA or control chunk
631 * to which it is replying.
632 *
633 * [COOKIE ACK back to where the COOKIE ECHO came from.]
634 */
635 if (retval && chunk && chunk->transport)
636 retval->transport =
637 sctp_assoc_lookup_paddr(asoc,
638 &chunk->transport->ipaddr);
639
640 return retval;
641}
642
643/*
644 * Appendix A: Explicit Congestion Notification:
645 * CWR:
646 *
647 * RFC 2481 details a specific bit for a sender to send in the header of
648 * its next outbound TCP segment to indicate to its peer that it has
649 * reduced its congestion window. This is termed the CWR bit. For
650 * SCTP the same indication is made by including the CWR chunk.
651 * This chunk contains one data element, i.e. the TSN number that
652 * was sent in the ECNE chunk. This element represents the lowest
653 * TSN number in the datagram that was originally marked with the
654 * CE bit.
655 *
656 * 0 1 2 3
657 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
658 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
659 * | Chunk Type=13 | Flags=00000000| Chunk Length = 8 |
660 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
661 * | Lowest TSN Number |
662 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
663 *
664 * Note: The CWR is considered a Control chunk.
665 */
666struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc,
667 const __u32 lowest_tsn,
668 const struct sctp_chunk *chunk)
669{
670 struct sctp_chunk *retval;
671 struct sctp_cwrhdr cwr;
672
673 cwr.lowest_tsn = htonl(lowest_tsn);
674 retval = sctp_make_control(asoc, SCTP_CID_ECN_CWR, 0,
675 sizeof(cwr), GFP_ATOMIC);
676
677 if (!retval)
678 goto nodata;
679
680 retval->subh.ecn_cwr_hdr =
681 sctp_addto_chunk(retval, sizeof(cwr), &cwr);
682
683 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
684 *
685 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
686 * HEARTBEAT ACK, * etc.) to the same destination transport
687 * address from which it * received the DATA or control chunk
688 * to which it is replying.
689 *
690 * [Report a reduced congestion window back to where the ECNE
691 * came from.]
692 */
693 if (chunk)
694 retval->transport = chunk->transport;
695
696nodata:
697 return retval;
698}
699
700/* Make an ECNE chunk. This is a congestion experienced report. */
701struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc,
702 const __u32 lowest_tsn)
703{
704 struct sctp_chunk *retval;
705 struct sctp_ecnehdr ecne;
706
707 ecne.lowest_tsn = htonl(lowest_tsn);
708 retval = sctp_make_control(asoc, SCTP_CID_ECN_ECNE, 0,
709 sizeof(ecne), GFP_ATOMIC);
710 if (!retval)
711 goto nodata;
712 retval->subh.ecne_hdr =
713 sctp_addto_chunk(retval, sizeof(ecne), &ecne);
714
715nodata:
716 return retval;
717}
718
719/* Make a DATA chunk for the given association from the provided
720 * parameters. However, do not populate the data payload.
721 */
722struct sctp_chunk *sctp_make_datafrag_empty(const struct sctp_association *asoc,
723 const struct sctp_sndrcvinfo *sinfo,
724 int len, __u8 flags, gfp_t gfp)
725{
726 struct sctp_chunk *retval;
727 struct sctp_datahdr dp;
728
729 /* We assign the TSN as LATE as possible, not here when
730 * creating the chunk.
731 */
732 memset(&dp, 0, sizeof(dp));
733 dp.ppid = sinfo->sinfo_ppid;
734 dp.stream = htons(sinfo->sinfo_stream);
735
736 /* Set the flags for an unordered send. */
737 if (sinfo->sinfo_flags & SCTP_UNORDERED)
738 flags |= SCTP_DATA_UNORDERED;
739
740 retval = sctp_make_data(asoc, flags, sizeof(dp) + len, gfp);
741 if (!retval)
742 return NULL;
743
744 retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp);
745 memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo));
746
747 return retval;
748}
749
750/* Create a selective ackowledgement (SACK) for the given
751 * association. This reports on which TSN's we've seen to date,
752 * including duplicates and gaps.
753 */
754struct sctp_chunk *sctp_make_sack(struct sctp_association *asoc)
755{
756 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
757 struct sctp_gap_ack_block gabs[SCTP_MAX_GABS];
758 __u16 num_gabs, num_dup_tsns;
759 struct sctp_transport *trans;
760 struct sctp_chunk *retval;
761 struct sctp_sackhdr sack;
762 __u32 ctsn;
763 int len;
764
765 memset(gabs, 0, sizeof(gabs));
766 ctsn = sctp_tsnmap_get_ctsn(map);
767
768 pr_debug("%s: sackCTSNAck sent:0x%x\n", __func__, ctsn);
769
770 /* How much room is needed in the chunk? */
771 num_gabs = sctp_tsnmap_num_gabs(map, gabs);
772 num_dup_tsns = sctp_tsnmap_num_dups(map);
773
774 /* Initialize the SACK header. */
775 sack.cum_tsn_ack = htonl(ctsn);
776 sack.a_rwnd = htonl(asoc->a_rwnd);
777 sack.num_gap_ack_blocks = htons(num_gabs);
778 sack.num_dup_tsns = htons(num_dup_tsns);
779
780 len = sizeof(sack)
781 + sizeof(struct sctp_gap_ack_block) * num_gabs
782 + sizeof(__u32) * num_dup_tsns;
783
784 /* Create the chunk. */
785 retval = sctp_make_control(asoc, SCTP_CID_SACK, 0, len, GFP_ATOMIC);
786 if (!retval)
787 goto nodata;
788
789 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
790 *
791 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
792 * HEARTBEAT ACK, etc.) to the same destination transport
793 * address from which it received the DATA or control chunk to
794 * which it is replying. This rule should also be followed if
795 * the endpoint is bundling DATA chunks together with the
796 * reply chunk.
797 *
798 * However, when acknowledging multiple DATA chunks received
799 * in packets from different source addresses in a single
800 * SACK, the SACK chunk may be transmitted to one of the
801 * destination transport addresses from which the DATA or
802 * control chunks being acknowledged were received.
803 *
804 * [BUG: We do not implement the following paragraph.
805 * Perhaps we should remember the last transport we used for a
806 * SACK and avoid that (if possible) if we have seen any
807 * duplicates. --piggy]
808 *
809 * When a receiver of a duplicate DATA chunk sends a SACK to a
810 * multi- homed endpoint it MAY be beneficial to vary the
811 * destination address and not use the source address of the
812 * DATA chunk. The reason being that receiving a duplicate
813 * from a multi-homed endpoint might indicate that the return
814 * path (as specified in the source address of the DATA chunk)
815 * for the SACK is broken.
816 *
817 * [Send to the address from which we last received a DATA chunk.]
818 */
819 retval->transport = asoc->peer.last_data_from;
820
821 retval->subh.sack_hdr =
822 sctp_addto_chunk(retval, sizeof(sack), &sack);
823
824 /* Add the gap ack block information. */
825 if (num_gabs)
826 sctp_addto_chunk(retval, sizeof(__u32) * num_gabs,
827 gabs);
828
829 /* Add the duplicate TSN information. */
830 if (num_dup_tsns) {
831 asoc->stats.idupchunks += num_dup_tsns;
832 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns,
833 sctp_tsnmap_get_dups(map));
834 }
835 /* Once we have a sack generated, check to see what our sack
836 * generation is, if its 0, reset the transports to 0, and reset
837 * the association generation to 1
838 *
839 * The idea is that zero is never used as a valid generation for the
840 * association so no transport will match after a wrap event like this,
841 * Until the next sack
842 */
843 if (++asoc->peer.sack_generation == 0) {
844 list_for_each_entry(trans, &asoc->peer.transport_addr_list,
845 transports)
846 trans->sack_generation = 0;
847 asoc->peer.sack_generation = 1;
848 }
849nodata:
850 return retval;
851}
852
853/* Make a SHUTDOWN chunk. */
854struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc,
855 const struct sctp_chunk *chunk)
856{
857 struct sctp_shutdownhdr shut;
858 struct sctp_chunk *retval;
859 __u32 ctsn;
860
861 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
862 shut.cum_tsn_ack = htonl(ctsn);
863
864 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN, 0,
865 sizeof(shut), GFP_ATOMIC);
866 if (!retval)
867 goto nodata;
868
869 retval->subh.shutdown_hdr =
870 sctp_addto_chunk(retval, sizeof(shut), &shut);
871
872 if (chunk)
873 retval->transport = chunk->transport;
874nodata:
875 return retval;
876}
877
878struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc,
879 const struct sctp_chunk *chunk)
880{
881 struct sctp_chunk *retval;
882
883 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0,
884 GFP_ATOMIC);
885
886 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
887 *
888 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
889 * HEARTBEAT ACK, * etc.) to the same destination transport
890 * address from which it * received the DATA or control chunk
891 * to which it is replying.
892 *
893 * [ACK back to where the SHUTDOWN came from.]
894 */
895 if (retval && chunk)
896 retval->transport = chunk->transport;
897
898 return retval;
899}
900
901struct sctp_chunk *sctp_make_shutdown_complete(
902 const struct sctp_association *asoc,
903 const struct sctp_chunk *chunk)
904{
905 struct sctp_chunk *retval;
906 __u8 flags = 0;
907
908 /* Set the T-bit if we have no association (vtag will be
909 * reflected)
910 */
911 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T;
912
913 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags,
914 0, GFP_ATOMIC);
915
916 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
917 *
918 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
919 * HEARTBEAT ACK, * etc.) to the same destination transport
920 * address from which it * received the DATA or control chunk
921 * to which it is replying.
922 *
923 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK
924 * came from.]
925 */
926 if (retval && chunk)
927 retval->transport = chunk->transport;
928
929 return retval;
930}
931
932/* Create an ABORT. Note that we set the T bit if we have no
933 * association, except when responding to an INIT (sctpimpguide 2.41).
934 */
935struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc,
936 const struct sctp_chunk *chunk,
937 const size_t hint)
938{
939 struct sctp_chunk *retval;
940 __u8 flags = 0;
941
942 /* Set the T-bit if we have no association and 'chunk' is not
943 * an INIT (vtag will be reflected).
944 */
945 if (!asoc) {
946 if (chunk && chunk->chunk_hdr &&
947 chunk->chunk_hdr->type == SCTP_CID_INIT)
948 flags = 0;
949 else
950 flags = SCTP_CHUNK_FLAG_T;
951 }
952
953 retval = sctp_make_control(asoc, SCTP_CID_ABORT, flags, hint,
954 GFP_ATOMIC);
955
956 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
957 *
958 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
959 * HEARTBEAT ACK, * etc.) to the same destination transport
960 * address from which it * received the DATA or control chunk
961 * to which it is replying.
962 *
963 * [ABORT back to where the offender came from.]
964 */
965 if (retval && chunk)
966 retval->transport = chunk->transport;
967
968 return retval;
969}
970
971/* Helper to create ABORT with a NO_USER_DATA error. */
972struct sctp_chunk *sctp_make_abort_no_data(
973 const struct sctp_association *asoc,
974 const struct sctp_chunk *chunk,
975 __u32 tsn)
976{
977 struct sctp_chunk *retval;
978 __be32 payload;
979
980 retval = sctp_make_abort(asoc, chunk,
981 sizeof(struct sctp_errhdr) + sizeof(tsn));
982
983 if (!retval)
984 goto no_mem;
985
986 /* Put the tsn back into network byte order. */
987 payload = htonl(tsn);
988 sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload));
989 sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload);
990
991 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
992 *
993 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
994 * HEARTBEAT ACK, * etc.) to the same destination transport
995 * address from which it * received the DATA or control chunk
996 * to which it is replying.
997 *
998 * [ABORT back to where the offender came from.]
999 */
1000 if (chunk)
1001 retval->transport = chunk->transport;
1002
1003no_mem:
1004 return retval;
1005}
1006
1007/* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */
1008struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc,
1009 struct msghdr *msg,
1010 size_t paylen)
1011{
1012 struct sctp_chunk *retval;
1013 void *payload = NULL;
1014 int err;
1015
1016 retval = sctp_make_abort(asoc, NULL,
1017 sizeof(struct sctp_errhdr) + paylen);
1018 if (!retval)
1019 goto err_chunk;
1020
1021 if (paylen) {
1022 /* Put the msg_iov together into payload. */
1023 payload = kmalloc(paylen, GFP_KERNEL);
1024 if (!payload)
1025 goto err_payload;
1026
1027 err = memcpy_from_msg(payload, msg, paylen);
1028 if (err < 0)
1029 goto err_copy;
1030 }
1031
1032 sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen);
1033 sctp_addto_chunk(retval, paylen, payload);
1034
1035 if (paylen)
1036 kfree(payload);
1037
1038 return retval;
1039
1040err_copy:
1041 kfree(payload);
1042err_payload:
1043 sctp_chunk_free(retval);
1044 retval = NULL;
1045err_chunk:
1046 return retval;
1047}
1048
1049/* Append bytes to the end of a parameter. Will panic if chunk is not big
1050 * enough.
1051 */
1052static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
1053 const void *data)
1054{
1055 int chunklen = ntohs(chunk->chunk_hdr->length);
1056 void *target;
1057
1058 target = skb_put(chunk->skb, len);
1059
1060 if (data)
1061 memcpy(target, data, len);
1062 else
1063 memset(target, 0, len);
1064
1065 /* Adjust the chunk length field. */
1066 chunk->chunk_hdr->length = htons(chunklen + len);
1067 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1068
1069 return target;
1070}
1071
1072/* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */
1073struct sctp_chunk *sctp_make_abort_violation(
1074 const struct sctp_association *asoc,
1075 const struct sctp_chunk *chunk,
1076 const __u8 *payload,
1077 const size_t paylen)
1078{
1079 struct sctp_chunk *retval;
1080 struct sctp_paramhdr phdr;
1081
1082 retval = sctp_make_abort(asoc, chunk, sizeof(struct sctp_errhdr) +
1083 paylen + sizeof(phdr));
1084 if (!retval)
1085 goto end;
1086
1087 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen +
1088 sizeof(phdr));
1089
1090 phdr.type = htons(chunk->chunk_hdr->type);
1091 phdr.length = chunk->chunk_hdr->length;
1092 sctp_addto_chunk(retval, paylen, payload);
1093 sctp_addto_param(retval, sizeof(phdr), &phdr);
1094
1095end:
1096 return retval;
1097}
1098
1099struct sctp_chunk *sctp_make_violation_paramlen(
1100 const struct sctp_association *asoc,
1101 const struct sctp_chunk *chunk,
1102 struct sctp_paramhdr *param)
1103{
1104 static const char error[] = "The following parameter had invalid length:";
1105 size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr) +
1106 sizeof(*param);
1107 struct sctp_chunk *retval;
1108
1109 retval = sctp_make_abort(asoc, chunk, payload_len);
1110 if (!retval)
1111 goto nodata;
1112
1113 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION,
1114 sizeof(error) + sizeof(*param));
1115 sctp_addto_chunk(retval, sizeof(error), error);
1116 sctp_addto_param(retval, sizeof(*param), param);
1117
1118nodata:
1119 return retval;
1120}
1121
1122struct sctp_chunk *sctp_make_violation_max_retrans(
1123 const struct sctp_association *asoc,
1124 const struct sctp_chunk *chunk)
1125{
1126 static const char error[] = "Association exceeded its max_retrans count";
1127 size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr);
1128 struct sctp_chunk *retval;
1129
1130 retval = sctp_make_abort(asoc, chunk, payload_len);
1131 if (!retval)
1132 goto nodata;
1133
1134 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error));
1135 sctp_addto_chunk(retval, sizeof(error), error);
1136
1137nodata:
1138 return retval;
1139}
1140
1141struct sctp_chunk *sctp_make_new_encap_port(const struct sctp_association *asoc,
1142 const struct sctp_chunk *chunk)
1143{
1144 struct sctp_new_encap_port_hdr nep;
1145 struct sctp_chunk *retval;
1146
1147 retval = sctp_make_abort(asoc, chunk,
1148 sizeof(struct sctp_errhdr) + sizeof(nep));
1149 if (!retval)
1150 goto nodata;
1151
1152 sctp_init_cause(retval, SCTP_ERROR_NEW_ENCAP_PORT, sizeof(nep));
1153 nep.cur_port = SCTP_INPUT_CB(chunk->skb)->encap_port;
1154 nep.new_port = chunk->transport->encap_port;
1155 sctp_addto_chunk(retval, sizeof(nep), &nep);
1156
1157nodata:
1158 return retval;
1159}
1160
1161/* Make a HEARTBEAT chunk. */
1162struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc,
1163 const struct sctp_transport *transport,
1164 __u32 probe_size)
1165{
1166 struct sctp_sender_hb_info hbinfo = {};
1167 struct sctp_chunk *retval;
1168
1169 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT, 0,
1170 sizeof(hbinfo), GFP_ATOMIC);
1171
1172 if (!retval)
1173 goto nodata;
1174
1175 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO;
1176 hbinfo.param_hdr.length = htons(sizeof(hbinfo));
1177 hbinfo.daddr = transport->ipaddr;
1178 hbinfo.sent_at = jiffies;
1179 hbinfo.hb_nonce = transport->hb_nonce;
1180 hbinfo.probe_size = probe_size;
1181
1182 /* Cast away the 'const', as this is just telling the chunk
1183 * what transport it belongs to.
1184 */
1185 retval->transport = (struct sctp_transport *) transport;
1186 retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo),
1187 &hbinfo);
1188 retval->pmtu_probe = !!probe_size;
1189
1190nodata:
1191 return retval;
1192}
1193
1194struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc,
1195 const struct sctp_chunk *chunk,
1196 const void *payload,
1197 const size_t paylen)
1198{
1199 struct sctp_chunk *retval;
1200
1201 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen,
1202 GFP_ATOMIC);
1203 if (!retval)
1204 goto nodata;
1205
1206 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload);
1207
1208 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
1209 *
1210 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1211 * HEARTBEAT ACK, * etc.) to the same destination transport
1212 * address from which it * received the DATA or control chunk
1213 * to which it is replying.
1214 *
1215 * [HBACK back to where the HEARTBEAT came from.]
1216 */
1217 if (chunk)
1218 retval->transport = chunk->transport;
1219
1220nodata:
1221 return retval;
1222}
1223
1224/* RFC4820 3. Padding Chunk (PAD)
1225 * 0 1 2 3
1226 * 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
1227 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1228 * | Type = 0x84 | Flags=0 | Length |
1229 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1230 * | |
1231 * \ Padding Data /
1232 * / \
1233 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
1234 */
1235struct sctp_chunk *sctp_make_pad(const struct sctp_association *asoc, int len)
1236{
1237 struct sctp_chunk *retval;
1238
1239 retval = sctp_make_control(asoc, SCTP_CID_PAD, 0, len, GFP_ATOMIC);
1240 if (!retval)
1241 return NULL;
1242
1243 skb_put_zero(retval->skb, len);
1244 retval->chunk_hdr->length = htons(ntohs(retval->chunk_hdr->length) + len);
1245 retval->chunk_end = skb_tail_pointer(retval->skb);
1246
1247 return retval;
1248}
1249
1250/* Create an Operation Error chunk with the specified space reserved.
1251 * This routine can be used for containing multiple causes in the chunk.
1252 */
1253static struct sctp_chunk *sctp_make_op_error_space(
1254 const struct sctp_association *asoc,
1255 const struct sctp_chunk *chunk,
1256 size_t size)
1257{
1258 struct sctp_chunk *retval;
1259
1260 retval = sctp_make_control(asoc, SCTP_CID_ERROR, 0,
1261 sizeof(struct sctp_errhdr) + size,
1262 GFP_ATOMIC);
1263 if (!retval)
1264 goto nodata;
1265
1266 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
1267 *
1268 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1269 * HEARTBEAT ACK, etc.) to the same destination transport
1270 * address from which it received the DATA or control chunk
1271 * to which it is replying.
1272 *
1273 */
1274 if (chunk)
1275 retval->transport = chunk->transport;
1276
1277nodata:
1278 return retval;
1279}
1280
1281/* Create an Operation Error chunk of a fixed size, specifically,
1282 * min(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT) - overheads.
1283 * This is a helper function to allocate an error chunk for those
1284 * invalid parameter codes in which we may not want to report all the
1285 * errors, if the incoming chunk is large. If it can't fit in a single
1286 * packet, we ignore it.
1287 */
1288static inline struct sctp_chunk *sctp_make_op_error_limited(
1289 const struct sctp_association *asoc,
1290 const struct sctp_chunk *chunk)
1291{
1292 size_t size = SCTP_DEFAULT_MAXSEGMENT;
1293 struct sctp_sock *sp = NULL;
1294
1295 if (asoc) {
1296 size = min_t(size_t, size, asoc->pathmtu);
1297 sp = sctp_sk(asoc->base.sk);
1298 }
1299
1300 size = sctp_mtu_payload(sp, size, sizeof(struct sctp_errhdr));
1301
1302 return sctp_make_op_error_space(asoc, chunk, size);
1303}
1304
1305/* Create an Operation Error chunk. */
1306struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc,
1307 const struct sctp_chunk *chunk,
1308 __be16 cause_code, const void *payload,
1309 size_t paylen, size_t reserve_tail)
1310{
1311 struct sctp_chunk *retval;
1312
1313 retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail);
1314 if (!retval)
1315 goto nodata;
1316
1317 sctp_init_cause(retval, cause_code, paylen + reserve_tail);
1318 sctp_addto_chunk(retval, paylen, payload);
1319 if (reserve_tail)
1320 sctp_addto_param(retval, reserve_tail, NULL);
1321
1322nodata:
1323 return retval;
1324}
1325
1326struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc,
1327 __u16 key_id)
1328{
1329 struct sctp_authhdr auth_hdr;
1330 struct sctp_hmac *hmac_desc;
1331 struct sctp_chunk *retval;
1332
1333 /* Get the first hmac that the peer told us to use */
1334 hmac_desc = sctp_auth_asoc_get_hmac(asoc);
1335 if (unlikely(!hmac_desc))
1336 return NULL;
1337
1338 retval = sctp_make_control(asoc, SCTP_CID_AUTH, 0,
1339 hmac_desc->hmac_len + sizeof(auth_hdr),
1340 GFP_ATOMIC);
1341 if (!retval)
1342 return NULL;
1343
1344 auth_hdr.hmac_id = htons(hmac_desc->hmac_id);
1345 auth_hdr.shkey_id = htons(key_id);
1346
1347 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(auth_hdr),
1348 &auth_hdr);
1349
1350 skb_put_zero(retval->skb, hmac_desc->hmac_len);
1351
1352 /* Adjust the chunk header to include the empty MAC */
1353 retval->chunk_hdr->length =
1354 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len);
1355 retval->chunk_end = skb_tail_pointer(retval->skb);
1356
1357 return retval;
1358}
1359
1360
1361/********************************************************************
1362 * 2nd Level Abstractions
1363 ********************************************************************/
1364
1365/* Turn an skb into a chunk.
1366 * FIXME: Eventually move the structure directly inside the skb->cb[].
1367 *
1368 * sctpimpguide-05.txt Section 2.8.2
1369 * M1) Each time a new DATA chunk is transmitted
1370 * set the 'TSN.Missing.Report' count for that TSN to 0. The
1371 * 'TSN.Missing.Report' count will be used to determine missing chunks
1372 * and when to fast retransmit.
1373 *
1374 */
1375struct sctp_chunk *sctp_chunkify(struct sk_buff *skb,
1376 const struct sctp_association *asoc,
1377 struct sock *sk, gfp_t gfp)
1378{
1379 struct sctp_chunk *retval;
1380
1381 retval = kmem_cache_zalloc(sctp_chunk_cachep, gfp);
1382
1383 if (!retval)
1384 goto nodata;
1385 if (!sk)
1386 pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb);
1387
1388 INIT_LIST_HEAD(&retval->list);
1389 retval->skb = skb;
1390 retval->asoc = (struct sctp_association *)asoc;
1391 retval->singleton = 1;
1392
1393 retval->fast_retransmit = SCTP_CAN_FRTX;
1394
1395 /* Polish the bead hole. */
1396 INIT_LIST_HEAD(&retval->transmitted_list);
1397 INIT_LIST_HEAD(&retval->frag_list);
1398 SCTP_DBG_OBJCNT_INC(chunk);
1399 refcount_set(&retval->refcnt, 1);
1400
1401nodata:
1402 return retval;
1403}
1404
1405/* Set chunk->source and dest based on the IP header in chunk->skb. */
1406void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src,
1407 union sctp_addr *dest)
1408{
1409 memcpy(&chunk->source, src, sizeof(union sctp_addr));
1410 memcpy(&chunk->dest, dest, sizeof(union sctp_addr));
1411}
1412
1413/* Extract the source address from a chunk. */
1414const union sctp_addr *sctp_source(const struct sctp_chunk *chunk)
1415{
1416 /* If we have a known transport, use that. */
1417 if (chunk->transport) {
1418 return &chunk->transport->ipaddr;
1419 } else {
1420 /* Otherwise, extract it from the IP header. */
1421 return &chunk->source;
1422 }
1423}
1424
1425/* Create a new chunk, setting the type and flags headers from the
1426 * arguments, reserving enough space for a 'paylen' byte payload.
1427 */
1428static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc,
1429 __u8 type, __u8 flags, int paylen,
1430 gfp_t gfp)
1431{
1432 struct sctp_chunkhdr *chunk_hdr;
1433 struct sctp_chunk *retval;
1434 struct sk_buff *skb;
1435 struct sock *sk;
1436 int chunklen;
1437
1438 chunklen = SCTP_PAD4(sizeof(*chunk_hdr) + paylen);
1439 if (chunklen > SCTP_MAX_CHUNK_LEN)
1440 goto nodata;
1441
1442 /* No need to allocate LL here, as this is only a chunk. */
1443 skb = alloc_skb(chunklen, gfp);
1444 if (!skb)
1445 goto nodata;
1446
1447 /* Make room for the chunk header. */
1448 chunk_hdr = (struct sctp_chunkhdr *)skb_put(skb, sizeof(*chunk_hdr));
1449 chunk_hdr->type = type;
1450 chunk_hdr->flags = flags;
1451 chunk_hdr->length = htons(sizeof(*chunk_hdr));
1452
1453 sk = asoc ? asoc->base.sk : NULL;
1454 retval = sctp_chunkify(skb, asoc, sk, gfp);
1455 if (!retval) {
1456 kfree_skb(skb);
1457 goto nodata;
1458 }
1459
1460 retval->chunk_hdr = chunk_hdr;
1461 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(*chunk_hdr);
1462
1463 /* Determine if the chunk needs to be authenticated */
1464 if (sctp_auth_send_cid(type, asoc))
1465 retval->auth = 1;
1466
1467 return retval;
1468nodata:
1469 return NULL;
1470}
1471
1472static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc,
1473 __u8 flags, int paylen, gfp_t gfp)
1474{
1475 return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen, gfp);
1476}
1477
1478struct sctp_chunk *sctp_make_idata(const struct sctp_association *asoc,
1479 __u8 flags, int paylen, gfp_t gfp)
1480{
1481 return _sctp_make_chunk(asoc, SCTP_CID_I_DATA, flags, paylen, gfp);
1482}
1483
1484static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc,
1485 __u8 type, __u8 flags, int paylen,
1486 gfp_t gfp)
1487{
1488 struct sctp_chunk *chunk;
1489
1490 chunk = _sctp_make_chunk(asoc, type, flags, paylen, gfp);
1491 if (chunk)
1492 sctp_control_set_owner_w(chunk);
1493
1494 return chunk;
1495}
1496
1497/* Release the memory occupied by a chunk. */
1498static void sctp_chunk_destroy(struct sctp_chunk *chunk)
1499{
1500 BUG_ON(!list_empty(&chunk->list));
1501 list_del_init(&chunk->transmitted_list);
1502
1503 consume_skb(chunk->skb);
1504 consume_skb(chunk->auth_chunk);
1505
1506 SCTP_DBG_OBJCNT_DEC(chunk);
1507 kmem_cache_free(sctp_chunk_cachep, chunk);
1508}
1509
1510/* Possibly, free the chunk. */
1511void sctp_chunk_free(struct sctp_chunk *chunk)
1512{
1513 /* Release our reference on the message tracker. */
1514 if (chunk->msg)
1515 sctp_datamsg_put(chunk->msg);
1516
1517 sctp_chunk_put(chunk);
1518}
1519
1520/* Grab a reference to the chunk. */
1521void sctp_chunk_hold(struct sctp_chunk *ch)
1522{
1523 refcount_inc(&ch->refcnt);
1524}
1525
1526/* Release a reference to the chunk. */
1527void sctp_chunk_put(struct sctp_chunk *ch)
1528{
1529 if (refcount_dec_and_test(&ch->refcnt))
1530 sctp_chunk_destroy(ch);
1531}
1532
1533/* Append bytes to the end of a chunk. Will panic if chunk is not big
1534 * enough.
1535 */
1536void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data)
1537{
1538 int chunklen = ntohs(chunk->chunk_hdr->length);
1539 int padlen = SCTP_PAD4(chunklen) - chunklen;
1540 void *target;
1541
1542 skb_put_zero(chunk->skb, padlen);
1543 target = skb_put_data(chunk->skb, data, len);
1544
1545 /* Adjust the chunk length field. */
1546 chunk->chunk_hdr->length = htons(chunklen + padlen + len);
1547 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1548
1549 return target;
1550}
1551
1552/* Append bytes from user space to the end of a chunk. Will panic if
1553 * chunk is not big enough.
1554 * Returns a kernel err value.
1555 */
1556int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
1557 struct iov_iter *from)
1558{
1559 void *target;
1560
1561 /* Make room in chunk for data. */
1562 target = skb_put(chunk->skb, len);
1563
1564 /* Copy data (whole iovec) into chunk */
1565 if (!copy_from_iter_full(target, len, from))
1566 return -EFAULT;
1567
1568 /* Adjust the chunk length field. */
1569 chunk->chunk_hdr->length =
1570 htons(ntohs(chunk->chunk_hdr->length) + len);
1571 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1572
1573 return 0;
1574}
1575
1576/* Helper function to assign a TSN if needed. This assumes that both
1577 * the data_hdr and association have already been assigned.
1578 */
1579void sctp_chunk_assign_ssn(struct sctp_chunk *chunk)
1580{
1581 struct sctp_stream *stream;
1582 struct sctp_chunk *lchunk;
1583 struct sctp_datamsg *msg;
1584 __u16 ssn, sid;
1585
1586 if (chunk->has_ssn)
1587 return;
1588
1589 /* All fragments will be on the same stream */
1590 sid = ntohs(chunk->subh.data_hdr->stream);
1591 stream = &chunk->asoc->stream;
1592
1593 /* Now assign the sequence number to the entire message.
1594 * All fragments must have the same stream sequence number.
1595 */
1596 msg = chunk->msg;
1597 list_for_each_entry(lchunk, &msg->chunks, frag_list) {
1598 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
1599 ssn = 0;
1600 } else {
1601 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG)
1602 ssn = sctp_ssn_next(stream, out, sid);
1603 else
1604 ssn = sctp_ssn_peek(stream, out, sid);
1605 }
1606
1607 lchunk->subh.data_hdr->ssn = htons(ssn);
1608 lchunk->has_ssn = 1;
1609 }
1610}
1611
1612/* Helper function to assign a TSN if needed. This assumes that both
1613 * the data_hdr and association have already been assigned.
1614 */
1615void sctp_chunk_assign_tsn(struct sctp_chunk *chunk)
1616{
1617 if (!chunk->has_tsn) {
1618 /* This is the last possible instant to
1619 * assign a TSN.
1620 */
1621 chunk->subh.data_hdr->tsn =
1622 htonl(sctp_association_get_next_tsn(chunk->asoc));
1623 chunk->has_tsn = 1;
1624 }
1625}
1626
1627/* Create a CLOSED association to use with an incoming packet. */
1628struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep,
1629 struct sctp_chunk *chunk,
1630 gfp_t gfp)
1631{
1632 struct sctp_association *asoc;
1633 enum sctp_scope scope;
1634 struct sk_buff *skb;
1635
1636 /* Create the bare association. */
1637 scope = sctp_scope(sctp_source(chunk));
1638 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp);
1639 if (!asoc)
1640 goto nodata;
1641 asoc->temp = 1;
1642 skb = chunk->skb;
1643 /* Create an entry for the source address of the packet. */
1644 SCTP_INPUT_CB(skb)->af->from_skb(&asoc->c.peer_addr, skb, 1);
1645
1646nodata:
1647 return asoc;
1648}
1649
1650/* Build a cookie representing asoc.
1651 * This INCLUDES the param header needed to put the cookie in the INIT ACK.
1652 */
1653static struct sctp_cookie_param *sctp_pack_cookie(
1654 const struct sctp_endpoint *ep,
1655 const struct sctp_association *asoc,
1656 const struct sctp_chunk *init_chunk,
1657 int *cookie_len, const __u8 *raw_addrs,
1658 int addrs_len)
1659{
1660 struct sctp_signed_cookie *cookie;
1661 struct sctp_cookie_param *retval;
1662 int headersize, bodysize;
1663
1664 /* Header size is static data prior to the actual cookie, including
1665 * any padding.
1666 */
1667 headersize = sizeof(struct sctp_paramhdr) +
1668 (sizeof(struct sctp_signed_cookie) -
1669 sizeof(struct sctp_cookie));
1670 bodysize = sizeof(struct sctp_cookie)
1671 + ntohs(init_chunk->chunk_hdr->length) + addrs_len;
1672
1673 /* Pad out the cookie to a multiple to make the signature
1674 * functions simpler to write.
1675 */
1676 if (bodysize % SCTP_COOKIE_MULTIPLE)
1677 bodysize += SCTP_COOKIE_MULTIPLE
1678 - (bodysize % SCTP_COOKIE_MULTIPLE);
1679 *cookie_len = headersize + bodysize;
1680
1681 /* Clear this memory since we are sending this data structure
1682 * out on the network.
1683 */
1684 retval = kzalloc(*cookie_len, GFP_ATOMIC);
1685 if (!retval)
1686 goto nodata;
1687
1688 cookie = (struct sctp_signed_cookie *) retval->body;
1689
1690 /* Set up the parameter header. */
1691 retval->p.type = SCTP_PARAM_STATE_COOKIE;
1692 retval->p.length = htons(*cookie_len);
1693
1694 /* Copy the cookie part of the association itself. */
1695 cookie->c = asoc->c;
1696 /* Save the raw address list length in the cookie. */
1697 cookie->c.raw_addr_list_len = addrs_len;
1698
1699 /* Remember PR-SCTP capability. */
1700 cookie->c.prsctp_capable = asoc->peer.prsctp_capable;
1701
1702 /* Save adaptation indication in the cookie. */
1703 cookie->c.adaptation_ind = asoc->peer.adaptation_ind;
1704
1705 /* Set an expiration time for the cookie. */
1706 cookie->c.expiration = ktime_add(asoc->cookie_life,
1707 ktime_get_real());
1708
1709 /* Copy the peer's init packet. */
1710 memcpy(cookie + 1, init_chunk->chunk_hdr,
1711 ntohs(init_chunk->chunk_hdr->length));
1712
1713 /* Copy the raw local address list of the association. */
1714 memcpy((__u8 *)(cookie + 1) +
1715 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len);
1716
1717 if (sctp_sk(ep->base.sk)->hmac) {
1718 struct crypto_shash *tfm = sctp_sk(ep->base.sk)->hmac;
1719 int err;
1720
1721 /* Sign the message. */
1722 err = crypto_shash_setkey(tfm, ep->secret_key,
1723 sizeof(ep->secret_key)) ?:
1724 crypto_shash_tfm_digest(tfm, (u8 *)&cookie->c, bodysize,
1725 cookie->signature);
1726 if (err)
1727 goto free_cookie;
1728 }
1729
1730 return retval;
1731
1732free_cookie:
1733 kfree(retval);
1734nodata:
1735 *cookie_len = 0;
1736 return NULL;
1737}
1738
1739/* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */
1740struct sctp_association *sctp_unpack_cookie(
1741 const struct sctp_endpoint *ep,
1742 const struct sctp_association *asoc,
1743 struct sctp_chunk *chunk, gfp_t gfp,
1744 int *error, struct sctp_chunk **errp)
1745{
1746 struct sctp_association *retval = NULL;
1747 int headersize, bodysize, fixed_size;
1748 struct sctp_signed_cookie *cookie;
1749 struct sk_buff *skb = chunk->skb;
1750 struct sctp_cookie *bear_cookie;
1751 __u8 *digest = ep->digest;
1752 enum sctp_scope scope;
1753 unsigned int len;
1754 ktime_t kt;
1755
1756 /* Header size is static data prior to the actual cookie, including
1757 * any padding.
1758 */
1759 headersize = sizeof(struct sctp_chunkhdr) +
1760 (sizeof(struct sctp_signed_cookie) -
1761 sizeof(struct sctp_cookie));
1762 bodysize = ntohs(chunk->chunk_hdr->length) - headersize;
1763 fixed_size = headersize + sizeof(struct sctp_cookie);
1764
1765 /* Verify that the chunk looks like it even has a cookie.
1766 * There must be enough room for our cookie and our peer's
1767 * INIT chunk.
1768 */
1769 len = ntohs(chunk->chunk_hdr->length);
1770 if (len < fixed_size + sizeof(struct sctp_chunkhdr))
1771 goto malformed;
1772
1773 /* Verify that the cookie has been padded out. */
1774 if (bodysize % SCTP_COOKIE_MULTIPLE)
1775 goto malformed;
1776
1777 /* Process the cookie. */
1778 cookie = chunk->subh.cookie_hdr;
1779 bear_cookie = &cookie->c;
1780
1781 if (!sctp_sk(ep->base.sk)->hmac)
1782 goto no_hmac;
1783
1784 /* Check the signature. */
1785 {
1786 struct crypto_shash *tfm = sctp_sk(ep->base.sk)->hmac;
1787 int err;
1788
1789 err = crypto_shash_setkey(tfm, ep->secret_key,
1790 sizeof(ep->secret_key)) ?:
1791 crypto_shash_tfm_digest(tfm, (u8 *)bear_cookie, bodysize,
1792 digest);
1793 if (err) {
1794 *error = -SCTP_IERROR_NOMEM;
1795 goto fail;
1796 }
1797 }
1798
1799 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
1800 *error = -SCTP_IERROR_BAD_SIG;
1801 goto fail;
1802 }
1803
1804no_hmac:
1805 /* IG Section 2.35.2:
1806 * 3) Compare the port numbers and the verification tag contained
1807 * within the COOKIE ECHO chunk to the actual port numbers and the
1808 * verification tag within the SCTP common header of the received
1809 * packet. If these values do not match the packet MUST be silently
1810 * discarded,
1811 */
1812 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) {
1813 *error = -SCTP_IERROR_BAD_TAG;
1814 goto fail;
1815 }
1816
1817 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port ||
1818 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) {
1819 *error = -SCTP_IERROR_BAD_PORTS;
1820 goto fail;
1821 }
1822
1823 /* Check to see if the cookie is stale. If there is already
1824 * an association, there is no need to check cookie's expiration
1825 * for init collision case of lost COOKIE ACK.
1826 * If skb has been timestamped, then use the stamp, otherwise
1827 * use current time. This introduces a small possibility that
1828 * a cookie may be considered expired, but this would only slow
1829 * down the new association establishment instead of every packet.
1830 */
1831 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP))
1832 kt = skb_get_ktime(skb);
1833 else
1834 kt = ktime_get_real();
1835
1836 if (!asoc && ktime_before(bear_cookie->expiration, kt)) {
1837 suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration));
1838 __be32 n = htonl(usecs);
1839
1840 /*
1841 * Section 3.3.10.3 Stale Cookie Error (3)
1842 *
1843 * Cause of error
1844 * ---------------
1845 * Stale Cookie Error: Indicates the receipt of a valid State
1846 * Cookie that has expired.
1847 */
1848 *errp = sctp_make_op_error(asoc, chunk,
1849 SCTP_ERROR_STALE_COOKIE, &n,
1850 sizeof(n), 0);
1851 if (*errp)
1852 *error = -SCTP_IERROR_STALE_COOKIE;
1853 else
1854 *error = -SCTP_IERROR_NOMEM;
1855
1856 goto fail;
1857 }
1858
1859 /* Make a new base association. */
1860 scope = sctp_scope(sctp_source(chunk));
1861 retval = sctp_association_new(ep, ep->base.sk, scope, gfp);
1862 if (!retval) {
1863 *error = -SCTP_IERROR_NOMEM;
1864 goto fail;
1865 }
1866
1867 /* Set up our peer's port number. */
1868 retval->peer.port = ntohs(chunk->sctp_hdr->source);
1869
1870 /* Populate the association from the cookie. */
1871 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie));
1872
1873 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie,
1874 GFP_ATOMIC) < 0) {
1875 *error = -SCTP_IERROR_NOMEM;
1876 goto fail;
1877 }
1878
1879 /* Also, add the destination address. */
1880 if (list_empty(&retval->base.bind_addr.address_list)) {
1881 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest,
1882 sizeof(chunk->dest), SCTP_ADDR_SRC,
1883 GFP_ATOMIC);
1884 }
1885
1886 retval->next_tsn = retval->c.initial_tsn;
1887 retval->ctsn_ack_point = retval->next_tsn - 1;
1888 retval->addip_serial = retval->c.initial_tsn;
1889 retval->strreset_outseq = retval->c.initial_tsn;
1890 retval->adv_peer_ack_point = retval->ctsn_ack_point;
1891 retval->peer.prsctp_capable = retval->c.prsctp_capable;
1892 retval->peer.adaptation_ind = retval->c.adaptation_ind;
1893
1894 /* The INIT stuff will be done by the side effects. */
1895 return retval;
1896
1897fail:
1898 if (retval)
1899 sctp_association_free(retval);
1900
1901 return NULL;
1902
1903malformed:
1904 /* Yikes! The packet is either corrupt or deliberately
1905 * malformed.
1906 */
1907 *error = -SCTP_IERROR_MALFORMED;
1908 goto fail;
1909}
1910
1911/********************************************************************
1912 * 3rd Level Abstractions
1913 ********************************************************************/
1914
1915struct __sctp_missing {
1916 __be32 num_missing;
1917 __be16 type;
1918} __packed;
1919
1920/*
1921 * Report a missing mandatory parameter.
1922 */
1923static int sctp_process_missing_param(const struct sctp_association *asoc,
1924 enum sctp_param paramtype,
1925 struct sctp_chunk *chunk,
1926 struct sctp_chunk **errp)
1927{
1928 struct __sctp_missing report;
1929 __u16 len;
1930
1931 len = SCTP_PAD4(sizeof(report));
1932
1933 /* Make an ERROR chunk, preparing enough room for
1934 * returning multiple unknown parameters.
1935 */
1936 if (!*errp)
1937 *errp = sctp_make_op_error_space(asoc, chunk, len);
1938
1939 if (*errp) {
1940 report.num_missing = htonl(1);
1941 report.type = paramtype;
1942 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM,
1943 sizeof(report));
1944 sctp_addto_chunk(*errp, sizeof(report), &report);
1945 }
1946
1947 /* Stop processing this chunk. */
1948 return 0;
1949}
1950
1951/* Report an Invalid Mandatory Parameter. */
1952static int sctp_process_inv_mandatory(const struct sctp_association *asoc,
1953 struct sctp_chunk *chunk,
1954 struct sctp_chunk **errp)
1955{
1956 /* Invalid Mandatory Parameter Error has no payload. */
1957
1958 if (!*errp)
1959 *errp = sctp_make_op_error_space(asoc, chunk, 0);
1960
1961 if (*errp)
1962 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0);
1963
1964 /* Stop processing this chunk. */
1965 return 0;
1966}
1967
1968static int sctp_process_inv_paramlength(const struct sctp_association *asoc,
1969 struct sctp_paramhdr *param,
1970 const struct sctp_chunk *chunk,
1971 struct sctp_chunk **errp)
1972{
1973 /* This is a fatal error. Any accumulated non-fatal errors are
1974 * not reported.
1975 */
1976 if (*errp)
1977 sctp_chunk_free(*errp);
1978
1979 /* Create an error chunk and fill it in with our payload. */
1980 *errp = sctp_make_violation_paramlen(asoc, chunk, param);
1981
1982 return 0;
1983}
1984
1985
1986/* Do not attempt to handle the HOST_NAME parm. However, do
1987 * send back an indicator to the peer.
1988 */
1989static int sctp_process_hn_param(const struct sctp_association *asoc,
1990 union sctp_params param,
1991 struct sctp_chunk *chunk,
1992 struct sctp_chunk **errp)
1993{
1994 __u16 len = ntohs(param.p->length);
1995
1996 /* Processing of the HOST_NAME parameter will generate an
1997 * ABORT. If we've accumulated any non-fatal errors, they
1998 * would be unrecognized parameters and we should not include
1999 * them in the ABORT.
2000 */
2001 if (*errp)
2002 sctp_chunk_free(*errp);
2003
2004 *errp = sctp_make_op_error(asoc, chunk, SCTP_ERROR_DNS_FAILED,
2005 param.v, len, 0);
2006
2007 /* Stop processing this chunk. */
2008 return 0;
2009}
2010
2011static int sctp_verify_ext_param(struct net *net,
2012 const struct sctp_endpoint *ep,
2013 union sctp_params param)
2014{
2015 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
2016 int have_asconf = 0;
2017 int have_auth = 0;
2018 int i;
2019
2020 for (i = 0; i < num_ext; i++) {
2021 switch (param.ext->chunks[i]) {
2022 case SCTP_CID_AUTH:
2023 have_auth = 1;
2024 break;
2025 case SCTP_CID_ASCONF:
2026 case SCTP_CID_ASCONF_ACK:
2027 have_asconf = 1;
2028 break;
2029 }
2030 }
2031
2032 /* ADD-IP Security: The draft requires us to ABORT or ignore the
2033 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this
2034 * only if ADD-IP is turned on and we are not backward-compatible
2035 * mode.
2036 */
2037 if (net->sctp.addip_noauth)
2038 return 1;
2039
2040 if (ep->asconf_enable && !have_auth && have_asconf)
2041 return 0;
2042
2043 return 1;
2044}
2045
2046static void sctp_process_ext_param(struct sctp_association *asoc,
2047 union sctp_params param)
2048{
2049 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
2050 int i;
2051
2052 for (i = 0; i < num_ext; i++) {
2053 switch (param.ext->chunks[i]) {
2054 case SCTP_CID_RECONF:
2055 if (asoc->ep->reconf_enable)
2056 asoc->peer.reconf_capable = 1;
2057 break;
2058 case SCTP_CID_FWD_TSN:
2059 if (asoc->ep->prsctp_enable)
2060 asoc->peer.prsctp_capable = 1;
2061 break;
2062 case SCTP_CID_AUTH:
2063 /* if the peer reports AUTH, assume that he
2064 * supports AUTH.
2065 */
2066 if (asoc->ep->auth_enable)
2067 asoc->peer.auth_capable = 1;
2068 break;
2069 case SCTP_CID_ASCONF:
2070 case SCTP_CID_ASCONF_ACK:
2071 if (asoc->ep->asconf_enable)
2072 asoc->peer.asconf_capable = 1;
2073 break;
2074 case SCTP_CID_I_DATA:
2075 if (asoc->ep->intl_enable)
2076 asoc->peer.intl_capable = 1;
2077 break;
2078 default:
2079 break;
2080 }
2081 }
2082}
2083
2084/* RFC 3.2.1 & the Implementers Guide 2.2.
2085 *
2086 * The Parameter Types are encoded such that the
2087 * highest-order two bits specify the action that must be
2088 * taken if the processing endpoint does not recognize the
2089 * Parameter Type.
2090 *
2091 * 00 - Stop processing this parameter; do not process any further
2092 * parameters within this chunk
2093 *
2094 * 01 - Stop processing this parameter, do not process any further
2095 * parameters within this chunk, and report the unrecognized
2096 * parameter in an 'Unrecognized Parameter' ERROR chunk.
2097 *
2098 * 10 - Skip this parameter and continue processing.
2099 *
2100 * 11 - Skip this parameter and continue processing but
2101 * report the unrecognized parameter in an
2102 * 'Unrecognized Parameter' ERROR chunk.
2103 *
2104 * Return value:
2105 * SCTP_IERROR_NO_ERROR - continue with the chunk
2106 * SCTP_IERROR_ERROR - stop and report an error.
2107 * SCTP_IERROR_NOMEME - out of memory.
2108 */
2109static enum sctp_ierror sctp_process_unk_param(
2110 const struct sctp_association *asoc,
2111 union sctp_params param,
2112 struct sctp_chunk *chunk,
2113 struct sctp_chunk **errp)
2114{
2115 int retval = SCTP_IERROR_NO_ERROR;
2116
2117 switch (param.p->type & SCTP_PARAM_ACTION_MASK) {
2118 case SCTP_PARAM_ACTION_DISCARD:
2119 retval = SCTP_IERROR_ERROR;
2120 break;
2121 case SCTP_PARAM_ACTION_SKIP:
2122 break;
2123 case SCTP_PARAM_ACTION_DISCARD_ERR:
2124 retval = SCTP_IERROR_ERROR;
2125 fallthrough;
2126 case SCTP_PARAM_ACTION_SKIP_ERR:
2127 /* Make an ERROR chunk, preparing enough room for
2128 * returning multiple unknown parameters.
2129 */
2130 if (!*errp) {
2131 *errp = sctp_make_op_error_limited(asoc, chunk);
2132 if (!*errp) {
2133 /* If there is no memory for generating the
2134 * ERROR report as specified, an ABORT will be
2135 * triggered to the peer and the association
2136 * won't be established.
2137 */
2138 retval = SCTP_IERROR_NOMEM;
2139 break;
2140 }
2141 }
2142
2143 if (!sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM,
2144 ntohs(param.p->length)))
2145 sctp_addto_chunk(*errp, ntohs(param.p->length),
2146 param.v);
2147 break;
2148 default:
2149 break;
2150 }
2151
2152 return retval;
2153}
2154
2155/* Verify variable length parameters
2156 * Return values:
2157 * SCTP_IERROR_ABORT - trigger an ABORT
2158 * SCTP_IERROR_NOMEM - out of memory (abort)
2159 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR
2160 * SCTP_IERROR_NO_ERROR - continue with the chunk
2161 */
2162static enum sctp_ierror sctp_verify_param(struct net *net,
2163 const struct sctp_endpoint *ep,
2164 const struct sctp_association *asoc,
2165 union sctp_params param,
2166 enum sctp_cid cid,
2167 struct sctp_chunk *chunk,
2168 struct sctp_chunk **err_chunk)
2169{
2170 struct sctp_hmac_algo_param *hmacs;
2171 int retval = SCTP_IERROR_NO_ERROR;
2172 __u16 n_elt, id = 0;
2173 int i;
2174
2175 /* FIXME - This routine is not looking at each parameter per the
2176 * chunk type, i.e., unrecognized parameters should be further
2177 * identified based on the chunk id.
2178 */
2179
2180 switch (param.p->type) {
2181 case SCTP_PARAM_IPV4_ADDRESS:
2182 case SCTP_PARAM_IPV6_ADDRESS:
2183 case SCTP_PARAM_COOKIE_PRESERVATIVE:
2184 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
2185 case SCTP_PARAM_STATE_COOKIE:
2186 case SCTP_PARAM_HEARTBEAT_INFO:
2187 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
2188 case SCTP_PARAM_ECN_CAPABLE:
2189 case SCTP_PARAM_ADAPTATION_LAYER_IND:
2190 break;
2191
2192 case SCTP_PARAM_SUPPORTED_EXT:
2193 if (!sctp_verify_ext_param(net, ep, param))
2194 return SCTP_IERROR_ABORT;
2195 break;
2196
2197 case SCTP_PARAM_SET_PRIMARY:
2198 if (!ep->asconf_enable)
2199 goto unhandled;
2200
2201 if (ntohs(param.p->length) < sizeof(struct sctp_addip_param) +
2202 sizeof(struct sctp_paramhdr)) {
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_HOST_NAME_ADDRESS:
2210 /* This param has been Deprecated, send ABORT. */
2211 sctp_process_hn_param(asoc, param, chunk, err_chunk);
2212 retval = SCTP_IERROR_ABORT;
2213 break;
2214
2215 case SCTP_PARAM_FWD_TSN_SUPPORT:
2216 if (ep->prsctp_enable)
2217 break;
2218 goto unhandled;
2219
2220 case SCTP_PARAM_RANDOM:
2221 if (!ep->auth_enable)
2222 goto unhandled;
2223
2224 /* SCTP-AUTH: Secion 6.1
2225 * If the random number is not 32 byte long the association
2226 * MUST be aborted. The ABORT chunk SHOULD contain the error
2227 * cause 'Protocol Violation'.
2228 */
2229 if (SCTP_AUTH_RANDOM_LENGTH != ntohs(param.p->length) -
2230 sizeof(struct sctp_paramhdr)) {
2231 sctp_process_inv_paramlength(asoc, param.p,
2232 chunk, err_chunk);
2233 retval = SCTP_IERROR_ABORT;
2234 }
2235 break;
2236
2237 case SCTP_PARAM_CHUNKS:
2238 if (!ep->auth_enable)
2239 goto unhandled;
2240
2241 /* SCTP-AUTH: Section 3.2
2242 * The CHUNKS parameter MUST be included once in the INIT or
2243 * INIT-ACK chunk if the sender wants to receive authenticated
2244 * chunks. Its maximum length is 260 bytes.
2245 */
2246 if (260 < ntohs(param.p->length)) {
2247 sctp_process_inv_paramlength(asoc, param.p,
2248 chunk, err_chunk);
2249 retval = SCTP_IERROR_ABORT;
2250 }
2251 break;
2252
2253 case SCTP_PARAM_HMAC_ALGO:
2254 if (!ep->auth_enable)
2255 goto unhandled;
2256
2257 hmacs = (struct sctp_hmac_algo_param *)param.p;
2258 n_elt = (ntohs(param.p->length) -
2259 sizeof(struct sctp_paramhdr)) >> 1;
2260
2261 /* SCTP-AUTH: Section 6.1
2262 * The HMAC algorithm based on SHA-1 MUST be supported and
2263 * included in the HMAC-ALGO parameter.
2264 */
2265 for (i = 0; i < n_elt; i++) {
2266 id = ntohs(hmacs->hmac_ids[i]);
2267
2268 if (id == SCTP_AUTH_HMAC_ID_SHA1)
2269 break;
2270 }
2271
2272 if (id != SCTP_AUTH_HMAC_ID_SHA1) {
2273 sctp_process_inv_paramlength(asoc, param.p, chunk,
2274 err_chunk);
2275 retval = SCTP_IERROR_ABORT;
2276 }
2277 break;
2278unhandled:
2279 default:
2280 pr_debug("%s: unrecognized param:%d for chunk:%d\n",
2281 __func__, ntohs(param.p->type), cid);
2282
2283 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk);
2284 break;
2285 }
2286 return retval;
2287}
2288
2289/* Verify the INIT packet before we process it. */
2290int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
2291 const struct sctp_association *asoc, enum sctp_cid cid,
2292 struct sctp_init_chunk *peer_init,
2293 struct sctp_chunk *chunk, struct sctp_chunk **errp)
2294{
2295 union sctp_params param;
2296 bool has_cookie = false;
2297 int result;
2298
2299 /* Check for missing mandatory parameters. Note: Initial TSN is
2300 * also mandatory, but is not checked here since the valid range
2301 * is 0..2**32-1. RFC4960, section 3.3.3.
2302 */
2303 if (peer_init->init_hdr.num_outbound_streams == 0 ||
2304 peer_init->init_hdr.num_inbound_streams == 0 ||
2305 peer_init->init_hdr.init_tag == 0 ||
2306 ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW)
2307 return sctp_process_inv_mandatory(asoc, chunk, errp);
2308
2309 sctp_walk_params(param, peer_init) {
2310 if (param.p->type == SCTP_PARAM_STATE_COOKIE)
2311 has_cookie = true;
2312 }
2313
2314 /* There is a possibility that a parameter length was bad and
2315 * in that case we would have stoped walking the parameters.
2316 * The current param.p would point at the bad one.
2317 * Current consensus on the mailing list is to generate a PROTOCOL
2318 * VIOLATION error. We build the ERROR chunk here and let the normal
2319 * error handling code build and send the packet.
2320 */
2321 if (param.v != (void *)chunk->chunk_end)
2322 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp);
2323
2324 /* The only missing mandatory param possible today is
2325 * the state cookie for an INIT-ACK chunk.
2326 */
2327 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie)
2328 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE,
2329 chunk, errp);
2330
2331 /* Verify all the variable length parameters */
2332 sctp_walk_params(param, peer_init) {
2333 result = sctp_verify_param(net, ep, asoc, param, cid,
2334 chunk, errp);
2335 switch (result) {
2336 case SCTP_IERROR_ABORT:
2337 case SCTP_IERROR_NOMEM:
2338 return 0;
2339 case SCTP_IERROR_ERROR:
2340 return 1;
2341 case SCTP_IERROR_NO_ERROR:
2342 default:
2343 break;
2344 }
2345
2346 } /* for (loop through all parameters) */
2347
2348 return 1;
2349}
2350
2351/* Unpack the parameters in an INIT packet into an association.
2352 * Returns 0 on failure, else success.
2353 * FIXME: This is an association method.
2354 */
2355int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk,
2356 const union sctp_addr *peer_addr,
2357 struct sctp_init_chunk *peer_init, gfp_t gfp)
2358{
2359 struct sctp_transport *transport;
2360 struct list_head *pos, *temp;
2361 union sctp_params param;
2362 union sctp_addr addr;
2363 struct sctp_af *af;
2364 int src_match = 0;
2365
2366 /* We must include the address that the INIT packet came from.
2367 * This is the only address that matters for an INIT packet.
2368 * When processing a COOKIE ECHO, we retrieve the from address
2369 * of the INIT from the cookie.
2370 */
2371
2372 /* This implementation defaults to making the first transport
2373 * added as the primary transport. The source address seems to
2374 * be a better choice than any of the embedded addresses.
2375 */
2376 asoc->encap_port = SCTP_INPUT_CB(chunk->skb)->encap_port;
2377 if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE))
2378 goto nomem;
2379
2380 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr))
2381 src_match = 1;
2382
2383 /* Process the initialization parameters. */
2384 sctp_walk_params(param, peer_init) {
2385 if (!src_match &&
2386 (param.p->type == SCTP_PARAM_IPV4_ADDRESS ||
2387 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) {
2388 af = sctp_get_af_specific(param_type2af(param.p->type));
2389 if (!af->from_addr_param(&addr, param.addr,
2390 chunk->sctp_hdr->source, 0))
2391 continue;
2392 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr))
2393 src_match = 1;
2394 }
2395
2396 if (!sctp_process_param(asoc, param, peer_addr, gfp))
2397 goto clean_up;
2398 }
2399
2400 /* source address of chunk may not match any valid address */
2401 if (!src_match)
2402 goto clean_up;
2403
2404 /* AUTH: After processing the parameters, make sure that we
2405 * have all the required info to potentially do authentications.
2406 */
2407 if (asoc->peer.auth_capable && (!asoc->peer.peer_random ||
2408 !asoc->peer.peer_hmacs))
2409 asoc->peer.auth_capable = 0;
2410
2411 /* In a non-backward compatible mode, if the peer claims
2412 * support for ADD-IP but not AUTH, the ADD-IP spec states
2413 * that we MUST ABORT the association. Section 6. The section
2414 * also give us an option to silently ignore the packet, which
2415 * is what we'll do here.
2416 */
2417 if (!asoc->base.net->sctp.addip_noauth &&
2418 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) {
2419 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP |
2420 SCTP_PARAM_DEL_IP |
2421 SCTP_PARAM_SET_PRIMARY);
2422 asoc->peer.asconf_capable = 0;
2423 goto clean_up;
2424 }
2425
2426 /* Walk list of transports, removing transports in the UNKNOWN state. */
2427 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
2428 transport = list_entry(pos, struct sctp_transport, transports);
2429 if (transport->state == SCTP_UNKNOWN) {
2430 sctp_assoc_rm_peer(asoc, transport);
2431 }
2432 }
2433
2434 /* The fixed INIT headers are always in network byte
2435 * order.
2436 */
2437 asoc->peer.i.init_tag =
2438 ntohl(peer_init->init_hdr.init_tag);
2439 asoc->peer.i.a_rwnd =
2440 ntohl(peer_init->init_hdr.a_rwnd);
2441 asoc->peer.i.num_outbound_streams =
2442 ntohs(peer_init->init_hdr.num_outbound_streams);
2443 asoc->peer.i.num_inbound_streams =
2444 ntohs(peer_init->init_hdr.num_inbound_streams);
2445 asoc->peer.i.initial_tsn =
2446 ntohl(peer_init->init_hdr.initial_tsn);
2447
2448 asoc->strreset_inseq = asoc->peer.i.initial_tsn;
2449
2450 /* Apply the upper bounds for output streams based on peer's
2451 * number of inbound streams.
2452 */
2453 if (asoc->c.sinit_num_ostreams >
2454 ntohs(peer_init->init_hdr.num_inbound_streams)) {
2455 asoc->c.sinit_num_ostreams =
2456 ntohs(peer_init->init_hdr.num_inbound_streams);
2457 }
2458
2459 if (asoc->c.sinit_max_instreams >
2460 ntohs(peer_init->init_hdr.num_outbound_streams)) {
2461 asoc->c.sinit_max_instreams =
2462 ntohs(peer_init->init_hdr.num_outbound_streams);
2463 }
2464
2465 /* Copy Initiation tag from INIT to VT_peer in cookie. */
2466 asoc->c.peer_vtag = asoc->peer.i.init_tag;
2467
2468 /* Peer Rwnd : Current calculated value of the peer's rwnd. */
2469 asoc->peer.rwnd = asoc->peer.i.a_rwnd;
2470
2471 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily
2472 * high (for example, implementations MAY use the size of the receiver
2473 * advertised window).
2474 */
2475 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
2476 transports) {
2477 transport->ssthresh = asoc->peer.i.a_rwnd;
2478 }
2479
2480 /* Set up the TSN tracking pieces. */
2481 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
2482 asoc->peer.i.initial_tsn, gfp))
2483 goto clean_up;
2484
2485 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
2486 *
2487 * The stream sequence number in all the streams shall start
2488 * from 0 when the association is established. Also, when the
2489 * stream sequence number reaches the value 65535 the next
2490 * stream sequence number shall be set to 0.
2491 */
2492
2493 if (sctp_stream_init(&asoc->stream, asoc->c.sinit_num_ostreams,
2494 asoc->c.sinit_max_instreams, gfp))
2495 goto clean_up;
2496
2497 /* Update frag_point when stream_interleave may get changed. */
2498 sctp_assoc_update_frag_point(asoc);
2499
2500 if (!asoc->temp && sctp_assoc_set_id(asoc, gfp))
2501 goto clean_up;
2502
2503 /* ADDIP Section 4.1 ASCONF Chunk Procedures
2504 *
2505 * When an endpoint has an ASCONF signaled change to be sent to the
2506 * remote endpoint it should do the following:
2507 * ...
2508 * A2) A serial number should be assigned to the Chunk. The serial
2509 * number should be a monotonically increasing number. All serial
2510 * numbers are defined to be initialized at the start of the
2511 * association to the same value as the Initial TSN.
2512 */
2513 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1;
2514 return 1;
2515
2516clean_up:
2517 /* Release the transport structures. */
2518 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
2519 transport = list_entry(pos, struct sctp_transport, transports);
2520 if (transport->state != SCTP_ACTIVE)
2521 sctp_assoc_rm_peer(asoc, transport);
2522 }
2523
2524nomem:
2525 return 0;
2526}
2527
2528
2529/* Update asoc with the option described in param.
2530 *
2531 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT
2532 *
2533 * asoc is the association to update.
2534 * param is the variable length parameter to use for update.
2535 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO.
2536 * If the current packet is an INIT we want to minimize the amount of
2537 * work we do. In particular, we should not build transport
2538 * structures for the addresses.
2539 */
2540static int sctp_process_param(struct sctp_association *asoc,
2541 union sctp_params param,
2542 const union sctp_addr *peer_addr,
2543 gfp_t gfp)
2544{
2545 struct sctp_endpoint *ep = asoc->ep;
2546 union sctp_addr_param *addr_param;
2547 struct net *net = asoc->base.net;
2548 struct sctp_transport *t;
2549 enum sctp_scope scope;
2550 union sctp_addr addr;
2551 struct sctp_af *af;
2552 int retval = 1, i;
2553 u32 stale;
2554 __u16 sat;
2555
2556 /* We maintain all INIT parameters in network byte order all the
2557 * time. This allows us to not worry about whether the parameters
2558 * came from a fresh INIT, and INIT ACK, or were stored in a cookie.
2559 */
2560 switch (param.p->type) {
2561 case SCTP_PARAM_IPV6_ADDRESS:
2562 if (PF_INET6 != asoc->base.sk->sk_family)
2563 break;
2564 goto do_addr_param;
2565
2566 case SCTP_PARAM_IPV4_ADDRESS:
2567 /* v4 addresses are not allowed on v6-only socket */
2568 if (ipv6_only_sock(asoc->base.sk))
2569 break;
2570do_addr_param:
2571 af = sctp_get_af_specific(param_type2af(param.p->type));
2572 if (!af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0))
2573 break;
2574 scope = sctp_scope(peer_addr);
2575 if (sctp_in_scope(net, &addr, scope))
2576 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED))
2577 return 0;
2578 break;
2579
2580 case SCTP_PARAM_COOKIE_PRESERVATIVE:
2581 if (!net->sctp.cookie_preserve_enable)
2582 break;
2583
2584 stale = ntohl(param.life->lifespan_increment);
2585
2586 /* Suggested Cookie Life span increment's unit is msec,
2587 * (1/1000sec).
2588 */
2589 asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale);
2590 break;
2591
2592 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
2593 /* Turn off the default values first so we'll know which
2594 * ones are really set by the peer.
2595 */
2596 asoc->peer.ipv4_address = 0;
2597 asoc->peer.ipv6_address = 0;
2598
2599 /* Assume that peer supports the address family
2600 * by which it sends a packet.
2601 */
2602 if (peer_addr->sa.sa_family == AF_INET6)
2603 asoc->peer.ipv6_address = 1;
2604 else if (peer_addr->sa.sa_family == AF_INET)
2605 asoc->peer.ipv4_address = 1;
2606
2607 /* Cycle through address types; avoid divide by 0. */
2608 sat = ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
2609 if (sat)
2610 sat /= sizeof(__u16);
2611
2612 for (i = 0; i < sat; ++i) {
2613 switch (param.sat->types[i]) {
2614 case SCTP_PARAM_IPV4_ADDRESS:
2615 asoc->peer.ipv4_address = 1;
2616 break;
2617
2618 case SCTP_PARAM_IPV6_ADDRESS:
2619 if (PF_INET6 == asoc->base.sk->sk_family)
2620 asoc->peer.ipv6_address = 1;
2621 break;
2622
2623 default: /* Just ignore anything else. */
2624 break;
2625 }
2626 }
2627 break;
2628
2629 case SCTP_PARAM_STATE_COOKIE:
2630 asoc->peer.cookie_len =
2631 ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
2632 kfree(asoc->peer.cookie);
2633 asoc->peer.cookie = kmemdup(param.cookie->body, asoc->peer.cookie_len, gfp);
2634 if (!asoc->peer.cookie)
2635 retval = 0;
2636 break;
2637
2638 case SCTP_PARAM_HEARTBEAT_INFO:
2639 /* Would be odd to receive, but it causes no problems. */
2640 break;
2641
2642 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
2643 /* Rejected during verify stage. */
2644 break;
2645
2646 case SCTP_PARAM_ECN_CAPABLE:
2647 if (asoc->ep->ecn_enable) {
2648 asoc->peer.ecn_capable = 1;
2649 break;
2650 }
2651 /* Fall Through */
2652 goto fall_through;
2653
2654
2655 case SCTP_PARAM_ADAPTATION_LAYER_IND:
2656 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind);
2657 break;
2658
2659 case SCTP_PARAM_SET_PRIMARY:
2660 if (!ep->asconf_enable)
2661 goto fall_through;
2662
2663 addr_param = param.v + sizeof(struct sctp_addip_param);
2664
2665 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
2666 if (!af)
2667 break;
2668
2669 if (!af->from_addr_param(&addr, addr_param,
2670 htons(asoc->peer.port), 0))
2671 break;
2672
2673 if (!af->addr_valid(&addr, NULL, NULL))
2674 break;
2675
2676 t = sctp_assoc_lookup_paddr(asoc, &addr);
2677 if (!t)
2678 break;
2679
2680 sctp_assoc_set_primary(asoc, t);
2681 break;
2682
2683 case SCTP_PARAM_SUPPORTED_EXT:
2684 sctp_process_ext_param(asoc, param);
2685 break;
2686
2687 case SCTP_PARAM_FWD_TSN_SUPPORT:
2688 if (asoc->ep->prsctp_enable) {
2689 asoc->peer.prsctp_capable = 1;
2690 break;
2691 }
2692 /* Fall Through */
2693 goto fall_through;
2694
2695 case SCTP_PARAM_RANDOM:
2696 if (!ep->auth_enable)
2697 goto fall_through;
2698
2699 /* Save peer's random parameter */
2700 kfree(asoc->peer.peer_random);
2701 asoc->peer.peer_random = kmemdup(param.p,
2702 ntohs(param.p->length), gfp);
2703 if (!asoc->peer.peer_random) {
2704 retval = 0;
2705 break;
2706 }
2707 break;
2708
2709 case SCTP_PARAM_HMAC_ALGO:
2710 if (!ep->auth_enable)
2711 goto fall_through;
2712
2713 /* Save peer's HMAC list */
2714 kfree(asoc->peer.peer_hmacs);
2715 asoc->peer.peer_hmacs = kmemdup(param.p,
2716 ntohs(param.p->length), gfp);
2717 if (!asoc->peer.peer_hmacs) {
2718 retval = 0;
2719 break;
2720 }
2721
2722 /* Set the default HMAC the peer requested*/
2723 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo);
2724 break;
2725
2726 case SCTP_PARAM_CHUNKS:
2727 if (!ep->auth_enable)
2728 goto fall_through;
2729
2730 kfree(asoc->peer.peer_chunks);
2731 asoc->peer.peer_chunks = kmemdup(param.p,
2732 ntohs(param.p->length), gfp);
2733 if (!asoc->peer.peer_chunks)
2734 retval = 0;
2735 break;
2736fall_through:
2737 default:
2738 /* Any unrecognized parameters should have been caught
2739 * and handled by sctp_verify_param() which should be
2740 * called prior to this routine. Simply log the error
2741 * here.
2742 */
2743 pr_debug("%s: ignoring param:%d for association:%p.\n",
2744 __func__, ntohs(param.p->type), asoc);
2745 break;
2746 }
2747
2748 return retval;
2749}
2750
2751/* Select a new verification tag. */
2752__u32 sctp_generate_tag(const struct sctp_endpoint *ep)
2753{
2754 /* I believe that this random number generator complies with RFC1750.
2755 * A tag of 0 is reserved for special cases (e.g. INIT).
2756 */
2757 __u32 x;
2758
2759 do {
2760 get_random_bytes(&x, sizeof(__u32));
2761 } while (x == 0);
2762
2763 return x;
2764}
2765
2766/* Select an initial TSN to send during startup. */
2767__u32 sctp_generate_tsn(const struct sctp_endpoint *ep)
2768{
2769 __u32 retval;
2770
2771 get_random_bytes(&retval, sizeof(__u32));
2772 return retval;
2773}
2774
2775/*
2776 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF)
2777 * 0 1 2 3
2778 * 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
2779 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2780 * | Type = 0xC1 | Chunk Flags | Chunk Length |
2781 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2782 * | Serial Number |
2783 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2784 * | Address Parameter |
2785 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2786 * | ASCONF Parameter #1 |
2787 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2788 * \ \
2789 * / .... /
2790 * \ \
2791 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2792 * | ASCONF Parameter #N |
2793 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2794 *
2795 * Address Parameter and other parameter will not be wrapped in this function
2796 */
2797static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc,
2798 union sctp_addr *addr,
2799 int vparam_len)
2800{
2801 struct sctp_addiphdr asconf;
2802 struct sctp_chunk *retval;
2803 int length = sizeof(asconf) + vparam_len;
2804 union sctp_addr_param addrparam;
2805 int addrlen;
2806 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
2807
2808 addrlen = af->to_addr_param(addr, &addrparam);
2809 if (!addrlen)
2810 return NULL;
2811 length += addrlen;
2812
2813 /* Create the chunk. */
2814 retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length,
2815 GFP_ATOMIC);
2816 if (!retval)
2817 return NULL;
2818
2819 asconf.serial = htonl(asoc->addip_serial++);
2820
2821 retval->subh.addip_hdr =
2822 sctp_addto_chunk(retval, sizeof(asconf), &asconf);
2823 retval->param_hdr.v =
2824 sctp_addto_chunk(retval, addrlen, &addrparam);
2825
2826 return retval;
2827}
2828
2829/* ADDIP
2830 * 3.2.1 Add IP Address
2831 * 0 1 2 3
2832 * 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
2833 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2834 * | Type = 0xC001 | Length = Variable |
2835 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2836 * | ASCONF-Request Correlation ID |
2837 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2838 * | Address Parameter |
2839 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2840 *
2841 * 3.2.2 Delete IP Address
2842 * 0 1 2 3
2843 * 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
2844 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2845 * | Type = 0xC002 | Length = Variable |
2846 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2847 * | ASCONF-Request Correlation ID |
2848 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2849 * | Address Parameter |
2850 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2851 *
2852 */
2853struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc,
2854 union sctp_addr *laddr,
2855 struct sockaddr *addrs,
2856 int addrcnt, __be16 flags)
2857{
2858 union sctp_addr_param addr_param;
2859 struct sctp_addip_param param;
2860 int paramlen = sizeof(param);
2861 struct sctp_chunk *retval;
2862 int addr_param_len = 0;
2863 union sctp_addr *addr;
2864 int totallen = 0, i;
2865 int del_pickup = 0;
2866 struct sctp_af *af;
2867 void *addr_buf;
2868
2869 /* Get total length of all the address parameters. */
2870 addr_buf = addrs;
2871 for (i = 0; i < addrcnt; i++) {
2872 addr = addr_buf;
2873 af = sctp_get_af_specific(addr->v4.sin_family);
2874 addr_param_len = af->to_addr_param(addr, &addr_param);
2875
2876 totallen += paramlen;
2877 totallen += addr_param_len;
2878
2879 addr_buf += af->sockaddr_len;
2880 if (asoc->asconf_addr_del_pending && !del_pickup) {
2881 /* reuse the parameter length from the same scope one */
2882 totallen += paramlen;
2883 totallen += addr_param_len;
2884 del_pickup = 1;
2885
2886 pr_debug("%s: picked same-scope del_pending addr, "
2887 "totallen for all addresses is %d\n",
2888 __func__, totallen);
2889 }
2890 }
2891
2892 /* Create an asconf chunk with the required length. */
2893 retval = sctp_make_asconf(asoc, laddr, totallen);
2894 if (!retval)
2895 return NULL;
2896
2897 /* Add the address parameters to the asconf chunk. */
2898 addr_buf = addrs;
2899 for (i = 0; i < addrcnt; i++) {
2900 addr = addr_buf;
2901 af = sctp_get_af_specific(addr->v4.sin_family);
2902 addr_param_len = af->to_addr_param(addr, &addr_param);
2903 param.param_hdr.type = flags;
2904 param.param_hdr.length = htons(paramlen + addr_param_len);
2905 param.crr_id = htonl(i);
2906
2907 sctp_addto_chunk(retval, paramlen, ¶m);
2908 sctp_addto_chunk(retval, addr_param_len, &addr_param);
2909
2910 addr_buf += af->sockaddr_len;
2911 }
2912 if (flags == SCTP_PARAM_ADD_IP && del_pickup) {
2913 addr = asoc->asconf_addr_del_pending;
2914 af = sctp_get_af_specific(addr->v4.sin_family);
2915 addr_param_len = af->to_addr_param(addr, &addr_param);
2916 param.param_hdr.type = SCTP_PARAM_DEL_IP;
2917 param.param_hdr.length = htons(paramlen + addr_param_len);
2918 param.crr_id = htonl(i);
2919
2920 sctp_addto_chunk(retval, paramlen, ¶m);
2921 sctp_addto_chunk(retval, addr_param_len, &addr_param);
2922 }
2923 return retval;
2924}
2925
2926/* ADDIP
2927 * 3.2.4 Set Primary IP Address
2928 * 0 1 2 3
2929 * 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
2930 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2931 * | Type =0xC004 | Length = Variable |
2932 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2933 * | ASCONF-Request Correlation ID |
2934 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2935 * | Address Parameter |
2936 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2937 *
2938 * Create an ASCONF chunk with Set Primary IP address parameter.
2939 */
2940struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
2941 union sctp_addr *addr)
2942{
2943 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
2944 union sctp_addr_param addrparam;
2945 struct sctp_addip_param param;
2946 struct sctp_chunk *retval;
2947 int len = sizeof(param);
2948 int addrlen;
2949
2950 addrlen = af->to_addr_param(addr, &addrparam);
2951 if (!addrlen)
2952 return NULL;
2953 len += addrlen;
2954
2955 /* Create the chunk and make asconf header. */
2956 retval = sctp_make_asconf(asoc, addr, len);
2957 if (!retval)
2958 return NULL;
2959
2960 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY;
2961 param.param_hdr.length = htons(len);
2962 param.crr_id = 0;
2963
2964 sctp_addto_chunk(retval, sizeof(param), ¶m);
2965 sctp_addto_chunk(retval, addrlen, &addrparam);
2966
2967 return retval;
2968}
2969
2970/* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK)
2971 * 0 1 2 3
2972 * 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
2973 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2974 * | Type = 0x80 | Chunk Flags | Chunk Length |
2975 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2976 * | Serial Number |
2977 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2978 * | ASCONF Parameter Response#1 |
2979 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2980 * \ \
2981 * / .... /
2982 * \ \
2983 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2984 * | ASCONF Parameter Response#N |
2985 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2986 *
2987 * Create an ASCONF_ACK chunk with enough space for the parameter responses.
2988 */
2989static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc,
2990 __u32 serial, int vparam_len)
2991{
2992 struct sctp_addiphdr asconf;
2993 struct sctp_chunk *retval;
2994 int length = sizeof(asconf) + vparam_len;
2995
2996 /* Create the chunk. */
2997 retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length,
2998 GFP_ATOMIC);
2999 if (!retval)
3000 return NULL;
3001
3002 asconf.serial = htonl(serial);
3003
3004 retval->subh.addip_hdr =
3005 sctp_addto_chunk(retval, sizeof(asconf), &asconf);
3006
3007 return retval;
3008}
3009
3010/* Add response parameters to an ASCONF_ACK chunk. */
3011static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id,
3012 __be16 err_code,
3013 struct sctp_addip_param *asconf_param)
3014{
3015 struct sctp_addip_param ack_param;
3016 struct sctp_errhdr err_param;
3017 int asconf_param_len = 0;
3018 int err_param_len = 0;
3019 __be16 response_type;
3020
3021 if (SCTP_ERROR_NO_ERROR == err_code) {
3022 response_type = SCTP_PARAM_SUCCESS_REPORT;
3023 } else {
3024 response_type = SCTP_PARAM_ERR_CAUSE;
3025 err_param_len = sizeof(err_param);
3026 if (asconf_param)
3027 asconf_param_len =
3028 ntohs(asconf_param->param_hdr.length);
3029 }
3030
3031 /* Add Success Indication or Error Cause Indication parameter. */
3032 ack_param.param_hdr.type = response_type;
3033 ack_param.param_hdr.length = htons(sizeof(ack_param) +
3034 err_param_len +
3035 asconf_param_len);
3036 ack_param.crr_id = crr_id;
3037 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param);
3038
3039 if (SCTP_ERROR_NO_ERROR == err_code)
3040 return;
3041
3042 /* Add Error Cause parameter. */
3043 err_param.cause = err_code;
3044 err_param.length = htons(err_param_len + asconf_param_len);
3045 sctp_addto_chunk(chunk, err_param_len, &err_param);
3046
3047 /* Add the failed TLV copied from ASCONF chunk. */
3048 if (asconf_param)
3049 sctp_addto_chunk(chunk, asconf_param_len, asconf_param);
3050}
3051
3052/* Process a asconf parameter. */
3053static __be16 sctp_process_asconf_param(struct sctp_association *asoc,
3054 struct sctp_chunk *asconf,
3055 struct sctp_addip_param *asconf_param)
3056{
3057 union sctp_addr_param *addr_param;
3058 struct sctp_transport *peer;
3059 union sctp_addr addr;
3060 struct sctp_af *af;
3061
3062 addr_param = (void *)asconf_param + sizeof(*asconf_param);
3063
3064 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP &&
3065 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP &&
3066 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY)
3067 return SCTP_ERROR_UNKNOWN_PARAM;
3068
3069 switch (addr_param->p.type) {
3070 case SCTP_PARAM_IPV6_ADDRESS:
3071 if (!asoc->peer.ipv6_address)
3072 return SCTP_ERROR_DNS_FAILED;
3073 break;
3074 case SCTP_PARAM_IPV4_ADDRESS:
3075 if (!asoc->peer.ipv4_address)
3076 return SCTP_ERROR_DNS_FAILED;
3077 break;
3078 default:
3079 return SCTP_ERROR_DNS_FAILED;
3080 }
3081
3082 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
3083 if (unlikely(!af))
3084 return SCTP_ERROR_DNS_FAILED;
3085
3086 if (!af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0))
3087 return SCTP_ERROR_DNS_FAILED;
3088
3089 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast
3090 * or multicast address.
3091 * (note: wildcard is permitted and requires special handling so
3092 * make sure we check for that)
3093 */
3094 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb))
3095 return SCTP_ERROR_DNS_FAILED;
3096
3097 switch (asconf_param->param_hdr.type) {
3098 case SCTP_PARAM_ADD_IP:
3099 /* Section 4.2.1:
3100 * If the address 0.0.0.0 or ::0 is provided, the source
3101 * address of the packet MUST be added.
3102 */
3103 if (af->is_any(&addr))
3104 memcpy(&addr, &asconf->source, sizeof(addr));
3105
3106 if (security_sctp_bind_connect(asoc->ep->base.sk,
3107 SCTP_PARAM_ADD_IP,
3108 (struct sockaddr *)&addr,
3109 af->sockaddr_len))
3110 return SCTP_ERROR_REQ_REFUSED;
3111
3112 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address
3113 * request and does not have the local resources to add this
3114 * new address to the association, it MUST return an Error
3115 * Cause TLV set to the new error code 'Operation Refused
3116 * Due to Resource Shortage'.
3117 */
3118
3119 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED);
3120 if (!peer)
3121 return SCTP_ERROR_RSRC_LOW;
3122
3123 /* Start the heartbeat timer. */
3124 sctp_transport_reset_hb_timer(peer);
3125 asoc->new_transport = peer;
3126 break;
3127 case SCTP_PARAM_DEL_IP:
3128 /* ADDIP 4.3 D7) If a request is received to delete the
3129 * last remaining IP address of a peer endpoint, the receiver
3130 * MUST send an Error Cause TLV with the error cause set to the
3131 * new error code 'Request to Delete Last Remaining IP Address'.
3132 */
3133 if (asoc->peer.transport_count == 1)
3134 return SCTP_ERROR_DEL_LAST_IP;
3135
3136 /* ADDIP 4.3 D8) If a request is received to delete an IP
3137 * address which is also the source address of the IP packet
3138 * which contained the ASCONF chunk, the receiver MUST reject
3139 * this request. To reject the request the receiver MUST send
3140 * an Error Cause TLV set to the new error code 'Request to
3141 * Delete Source IP Address'
3142 */
3143 if (sctp_cmp_addr_exact(&asconf->source, &addr))
3144 return SCTP_ERROR_DEL_SRC_IP;
3145
3146 /* Section 4.2.2
3147 * If the address 0.0.0.0 or ::0 is provided, all
3148 * addresses of the peer except the source address of the
3149 * packet MUST be deleted.
3150 */
3151 if (af->is_any(&addr)) {
3152 sctp_assoc_set_primary(asoc, asconf->transport);
3153 sctp_assoc_del_nonprimary_peers(asoc,
3154 asconf->transport);
3155 return SCTP_ERROR_NO_ERROR;
3156 }
3157
3158 /* If the address is not part of the association, the
3159 * ASCONF-ACK with Error Cause Indication Parameter
3160 * which including cause of Unresolvable Address should
3161 * be sent.
3162 */
3163 peer = sctp_assoc_lookup_paddr(asoc, &addr);
3164 if (!peer)
3165 return SCTP_ERROR_DNS_FAILED;
3166
3167 sctp_assoc_rm_peer(asoc, peer);
3168 break;
3169 case SCTP_PARAM_SET_PRIMARY:
3170 /* ADDIP Section 4.2.4
3171 * If the address 0.0.0.0 or ::0 is provided, the receiver
3172 * MAY mark the source address of the packet as its
3173 * primary.
3174 */
3175 if (af->is_any(&addr))
3176 memcpy(&addr, sctp_source(asconf), sizeof(addr));
3177
3178 if (security_sctp_bind_connect(asoc->ep->base.sk,
3179 SCTP_PARAM_SET_PRIMARY,
3180 (struct sockaddr *)&addr,
3181 af->sockaddr_len))
3182 return SCTP_ERROR_REQ_REFUSED;
3183
3184 peer = sctp_assoc_lookup_paddr(asoc, &addr);
3185 if (!peer)
3186 return SCTP_ERROR_DNS_FAILED;
3187
3188 sctp_assoc_set_primary(asoc, peer);
3189 break;
3190 }
3191
3192 return SCTP_ERROR_NO_ERROR;
3193}
3194
3195/* Verify the ASCONF packet before we process it. */
3196bool sctp_verify_asconf(const struct sctp_association *asoc,
3197 struct sctp_chunk *chunk, bool addr_param_needed,
3198 struct sctp_paramhdr **errp)
3199{
3200 struct sctp_addip_chunk *addip;
3201 bool addr_param_seen = false;
3202 union sctp_params param;
3203
3204 addip = (struct sctp_addip_chunk *)chunk->chunk_hdr;
3205 sctp_walk_params(param, addip) {
3206 size_t length = ntohs(param.p->length);
3207
3208 *errp = param.p;
3209 switch (param.p->type) {
3210 case SCTP_PARAM_ERR_CAUSE:
3211 break;
3212 case SCTP_PARAM_IPV4_ADDRESS:
3213 if (length != sizeof(struct sctp_ipv4addr_param))
3214 return false;
3215 /* ensure there is only one addr param and it's in the
3216 * beginning of addip_hdr params, or we reject it.
3217 */
3218 if (param.v != (addip + 1))
3219 return false;
3220 addr_param_seen = true;
3221 break;
3222 case SCTP_PARAM_IPV6_ADDRESS:
3223 if (length != sizeof(struct sctp_ipv6addr_param))
3224 return false;
3225 if (param.v != (addip + 1))
3226 return false;
3227 addr_param_seen = true;
3228 break;
3229 case SCTP_PARAM_ADD_IP:
3230 case SCTP_PARAM_DEL_IP:
3231 case SCTP_PARAM_SET_PRIMARY:
3232 /* In ASCONF chunks, these need to be first. */
3233 if (addr_param_needed && !addr_param_seen)
3234 return false;
3235 length = ntohs(param.addip->param_hdr.length);
3236 if (length < sizeof(struct sctp_addip_param) +
3237 sizeof(**errp))
3238 return false;
3239 break;
3240 case SCTP_PARAM_SUCCESS_REPORT:
3241 case SCTP_PARAM_ADAPTATION_LAYER_IND:
3242 if (length != sizeof(struct sctp_addip_param))
3243 return false;
3244 break;
3245 default:
3246 /* This is unknown to us, reject! */
3247 return false;
3248 }
3249 }
3250
3251 /* Remaining sanity checks. */
3252 if (addr_param_needed && !addr_param_seen)
3253 return false;
3254 if (!addr_param_needed && addr_param_seen)
3255 return false;
3256 if (param.v != chunk->chunk_end)
3257 return false;
3258
3259 return true;
3260}
3261
3262/* Process an incoming ASCONF chunk with the next expected serial no. and
3263 * return an ASCONF_ACK chunk to be sent in response.
3264 */
3265struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
3266 struct sctp_chunk *asconf)
3267{
3268 union sctp_addr_param *addr_param;
3269 struct sctp_addip_chunk *addip;
3270 struct sctp_chunk *asconf_ack;
3271 bool all_param_pass = true;
3272 struct sctp_addiphdr *hdr;
3273 int length = 0, chunk_len;
3274 union sctp_params param;
3275 __be16 err_code;
3276 __u32 serial;
3277
3278 addip = (struct sctp_addip_chunk *)asconf->chunk_hdr;
3279 chunk_len = ntohs(asconf->chunk_hdr->length) -
3280 sizeof(struct sctp_chunkhdr);
3281 hdr = (struct sctp_addiphdr *)asconf->skb->data;
3282 serial = ntohl(hdr->serial);
3283
3284 /* Skip the addiphdr and store a pointer to address parameter. */
3285 length = sizeof(*hdr);
3286 addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
3287 chunk_len -= length;
3288
3289 /* Skip the address parameter and store a pointer to the first
3290 * asconf parameter.
3291 */
3292 length = ntohs(addr_param->p.length);
3293 chunk_len -= length;
3294
3295 /* create an ASCONF_ACK chunk.
3296 * Based on the definitions of parameters, we know that the size of
3297 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF
3298 * parameters.
3299 */
3300 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4);
3301 if (!asconf_ack)
3302 goto done;
3303
3304 /* Process the TLVs contained within the ASCONF chunk. */
3305 sctp_walk_params(param, addip) {
3306 /* Skip preceding address parameters. */
3307 if (param.p->type == SCTP_PARAM_IPV4_ADDRESS ||
3308 param.p->type == SCTP_PARAM_IPV6_ADDRESS)
3309 continue;
3310
3311 err_code = sctp_process_asconf_param(asoc, asconf,
3312 param.addip);
3313 /* ADDIP 4.1 A7)
3314 * If an error response is received for a TLV parameter,
3315 * all TLVs with no response before the failed TLV are
3316 * considered successful if not reported. All TLVs after
3317 * the failed response are considered unsuccessful unless
3318 * a specific success indication is present for the parameter.
3319 */
3320 if (err_code != SCTP_ERROR_NO_ERROR)
3321 all_param_pass = false;
3322 if (!all_param_pass)
3323 sctp_add_asconf_response(asconf_ack, param.addip->crr_id,
3324 err_code, param.addip);
3325
3326 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add
3327 * an IP address sends an 'Out of Resource' in its response, it
3328 * MUST also fail any subsequent add or delete requests bundled
3329 * in the ASCONF.
3330 */
3331 if (err_code == SCTP_ERROR_RSRC_LOW)
3332 goto done;
3333 }
3334done:
3335 asoc->peer.addip_serial++;
3336
3337 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc
3338 * after freeing the reference to old asconf ack if any.
3339 */
3340 if (asconf_ack) {
3341 sctp_chunk_hold(asconf_ack);
3342 list_add_tail(&asconf_ack->transmitted_list,
3343 &asoc->asconf_ack_list);
3344 }
3345
3346 return asconf_ack;
3347}
3348
3349/* Process a asconf parameter that is successfully acked. */
3350static void sctp_asconf_param_success(struct sctp_association *asoc,
3351 struct sctp_addip_param *asconf_param)
3352{
3353 struct sctp_bind_addr *bp = &asoc->base.bind_addr;
3354 union sctp_addr_param *addr_param;
3355 struct sctp_sockaddr_entry *saddr;
3356 struct sctp_transport *transport;
3357 union sctp_addr addr;
3358 struct sctp_af *af;
3359
3360 addr_param = (void *)asconf_param + sizeof(*asconf_param);
3361
3362 /* We have checked the packet before, so we do not check again. */
3363 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
3364 if (!af->from_addr_param(&addr, addr_param, htons(bp->port), 0))
3365 return;
3366
3367 switch (asconf_param->param_hdr.type) {
3368 case SCTP_PARAM_ADD_IP:
3369 /* This is always done in BH context with a socket lock
3370 * held, so the list can not change.
3371 */
3372 local_bh_disable();
3373 list_for_each_entry(saddr, &bp->address_list, list) {
3374 if (sctp_cmp_addr_exact(&saddr->a, &addr))
3375 saddr->state = SCTP_ADDR_SRC;
3376 }
3377 local_bh_enable();
3378 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
3379 transports) {
3380 sctp_transport_dst_release(transport);
3381 }
3382 break;
3383 case SCTP_PARAM_DEL_IP:
3384 local_bh_disable();
3385 sctp_del_bind_addr(bp, &addr);
3386 if (asoc->asconf_addr_del_pending != NULL &&
3387 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) {
3388 kfree(asoc->asconf_addr_del_pending);
3389 asoc->asconf_addr_del_pending = NULL;
3390 }
3391 local_bh_enable();
3392 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
3393 transports) {
3394 sctp_transport_dst_release(transport);
3395 }
3396 break;
3397 default:
3398 break;
3399 }
3400}
3401
3402/* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk
3403 * for the given asconf parameter. If there is no response for this parameter,
3404 * return the error code based on the third argument 'no_err'.
3405 * ADDIP 4.1
3406 * A7) If an error response is received for a TLV parameter, all TLVs with no
3407 * response before the failed TLV are considered successful if not reported.
3408 * All TLVs after the failed response are considered unsuccessful unless a
3409 * specific success indication is present for the parameter.
3410 */
3411static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack,
3412 struct sctp_addip_param *asconf_param,
3413 int no_err)
3414{
3415 struct sctp_addip_param *asconf_ack_param;
3416 struct sctp_errhdr *err_param;
3417 int asconf_ack_len;
3418 __be16 err_code;
3419 int length;
3420
3421 if (no_err)
3422 err_code = SCTP_ERROR_NO_ERROR;
3423 else
3424 err_code = SCTP_ERROR_REQ_REFUSED;
3425
3426 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) -
3427 sizeof(struct sctp_chunkhdr);
3428
3429 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to
3430 * the first asconf_ack parameter.
3431 */
3432 length = sizeof(struct sctp_addiphdr);
3433 asconf_ack_param = (struct sctp_addip_param *)(asconf_ack->skb->data +
3434 length);
3435 asconf_ack_len -= length;
3436
3437 while (asconf_ack_len > 0) {
3438 if (asconf_ack_param->crr_id == asconf_param->crr_id) {
3439 switch (asconf_ack_param->param_hdr.type) {
3440 case SCTP_PARAM_SUCCESS_REPORT:
3441 return SCTP_ERROR_NO_ERROR;
3442 case SCTP_PARAM_ERR_CAUSE:
3443 length = sizeof(*asconf_ack_param);
3444 err_param = (void *)asconf_ack_param + length;
3445 asconf_ack_len -= length;
3446 if (asconf_ack_len > 0)
3447 return err_param->cause;
3448 else
3449 return SCTP_ERROR_INV_PARAM;
3450 break;
3451 default:
3452 return SCTP_ERROR_INV_PARAM;
3453 }
3454 }
3455
3456 length = ntohs(asconf_ack_param->param_hdr.length);
3457 asconf_ack_param = (void *)asconf_ack_param + length;
3458 asconf_ack_len -= length;
3459 }
3460
3461 return err_code;
3462}
3463
3464/* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */
3465int sctp_process_asconf_ack(struct sctp_association *asoc,
3466 struct sctp_chunk *asconf_ack)
3467{
3468 struct sctp_chunk *asconf = asoc->addip_last_asconf;
3469 struct sctp_addip_param *asconf_param;
3470 __be16 err_code = SCTP_ERROR_NO_ERROR;
3471 union sctp_addr_param *addr_param;
3472 int asconf_len = asconf->skb->len;
3473 int all_param_pass = 0;
3474 int length = 0;
3475 int no_err = 1;
3476 int retval = 0;
3477
3478 /* Skip the chunkhdr and addiphdr from the last asconf sent and store
3479 * a pointer to address parameter.
3480 */
3481 length = sizeof(struct sctp_addip_chunk);
3482 addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
3483 asconf_len -= length;
3484
3485 /* Skip the address parameter in the last asconf sent and store a
3486 * pointer to the first asconf parameter.
3487 */
3488 length = ntohs(addr_param->p.length);
3489 asconf_param = (void *)addr_param + length;
3490 asconf_len -= length;
3491
3492 /* ADDIP 4.1
3493 * A8) If there is no response(s) to specific TLV parameter(s), and no
3494 * failures are indicated, then all request(s) are considered
3495 * successful.
3496 */
3497 if (asconf_ack->skb->len == sizeof(struct sctp_addiphdr))
3498 all_param_pass = 1;
3499
3500 /* Process the TLVs contained in the last sent ASCONF chunk. */
3501 while (asconf_len > 0) {
3502 if (all_param_pass)
3503 err_code = SCTP_ERROR_NO_ERROR;
3504 else {
3505 err_code = sctp_get_asconf_response(asconf_ack,
3506 asconf_param,
3507 no_err);
3508 if (no_err && (SCTP_ERROR_NO_ERROR != err_code))
3509 no_err = 0;
3510 }
3511
3512 switch (err_code) {
3513 case SCTP_ERROR_NO_ERROR:
3514 sctp_asconf_param_success(asoc, asconf_param);
3515 break;
3516
3517 case SCTP_ERROR_RSRC_LOW:
3518 retval = 1;
3519 break;
3520
3521 case SCTP_ERROR_UNKNOWN_PARAM:
3522 /* Disable sending this type of asconf parameter in
3523 * future.
3524 */
3525 asoc->peer.addip_disabled_mask |=
3526 asconf_param->param_hdr.type;
3527 break;
3528
3529 case SCTP_ERROR_REQ_REFUSED:
3530 case SCTP_ERROR_DEL_LAST_IP:
3531 case SCTP_ERROR_DEL_SRC_IP:
3532 default:
3533 break;
3534 }
3535
3536 /* Skip the processed asconf parameter and move to the next
3537 * one.
3538 */
3539 length = ntohs(asconf_param->param_hdr.length);
3540 asconf_param = (void *)asconf_param + length;
3541 asconf_len -= length;
3542 }
3543
3544 if (no_err && asoc->src_out_of_asoc_ok) {
3545 asoc->src_out_of_asoc_ok = 0;
3546 sctp_transport_immediate_rtx(asoc->peer.primary_path);
3547 }
3548
3549 /* Free the cached last sent asconf chunk. */
3550 list_del_init(&asconf->transmitted_list);
3551 sctp_chunk_free(asconf);
3552 asoc->addip_last_asconf = NULL;
3553
3554 return retval;
3555}
3556
3557/* Make a FWD TSN chunk. */
3558struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
3559 __u32 new_cum_tsn, size_t nstreams,
3560 struct sctp_fwdtsn_skip *skiplist)
3561{
3562 struct sctp_chunk *retval = NULL;
3563 struct sctp_fwdtsn_hdr ftsn_hdr;
3564 struct sctp_fwdtsn_skip skip;
3565 size_t hint;
3566 int i;
3567
3568 hint = (nstreams + 1) * sizeof(__u32);
3569
3570 retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint, GFP_ATOMIC);
3571
3572 if (!retval)
3573 return NULL;
3574
3575 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn);
3576 retval->subh.fwdtsn_hdr =
3577 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr);
3578
3579 for (i = 0; i < nstreams; i++) {
3580 skip.stream = skiplist[i].stream;
3581 skip.ssn = skiplist[i].ssn;
3582 sctp_addto_chunk(retval, sizeof(skip), &skip);
3583 }
3584
3585 return retval;
3586}
3587
3588struct sctp_chunk *sctp_make_ifwdtsn(const struct sctp_association *asoc,
3589 __u32 new_cum_tsn, size_t nstreams,
3590 struct sctp_ifwdtsn_skip *skiplist)
3591{
3592 struct sctp_chunk *retval = NULL;
3593 struct sctp_ifwdtsn_hdr ftsn_hdr;
3594 size_t hint;
3595
3596 hint = (nstreams + 1) * sizeof(__u32);
3597
3598 retval = sctp_make_control(asoc, SCTP_CID_I_FWD_TSN, 0, hint,
3599 GFP_ATOMIC);
3600 if (!retval)
3601 return NULL;
3602
3603 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn);
3604 retval->subh.ifwdtsn_hdr =
3605 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr);
3606
3607 sctp_addto_chunk(retval, nstreams * sizeof(skiplist[0]), skiplist);
3608
3609 return retval;
3610}
3611
3612/* RE-CONFIG 3.1 (RE-CONFIG chunk)
3613 * 0 1 2 3
3614 * 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
3615 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3616 * | Type = 130 | Chunk Flags | Chunk Length |
3617 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3618 * \ \
3619 * / Re-configuration Parameter /
3620 * \ \
3621 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3622 * \ \
3623 * / Re-configuration Parameter (optional) /
3624 * \ \
3625 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3626 */
3627static struct sctp_chunk *sctp_make_reconf(const struct sctp_association *asoc,
3628 int length)
3629{
3630 struct sctp_reconf_chunk *reconf;
3631 struct sctp_chunk *retval;
3632
3633 retval = sctp_make_control(asoc, SCTP_CID_RECONF, 0, length,
3634 GFP_ATOMIC);
3635 if (!retval)
3636 return NULL;
3637
3638 reconf = (struct sctp_reconf_chunk *)retval->chunk_hdr;
3639 retval->param_hdr.v = (u8 *)(reconf + 1);
3640
3641 return retval;
3642}
3643
3644/* RE-CONFIG 4.1 (STREAM OUT RESET)
3645 * 0 1 2 3
3646 * 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
3647 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3648 * | Parameter Type = 13 | Parameter Length = 16 + 2 * N |
3649 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3650 * | Re-configuration Request Sequence Number |
3651 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3652 * | Re-configuration Response Sequence Number |
3653 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3654 * | Sender's Last Assigned TSN |
3655 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3656 * | Stream Number 1 (optional) | Stream Number 2 (optional) |
3657 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3658 * / ...... /
3659 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3660 * | Stream Number N-1 (optional) | Stream Number N (optional) |
3661 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3662 *
3663 * RE-CONFIG 4.2 (STREAM IN RESET)
3664 * 0 1 2 3
3665 * 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
3666 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3667 * | Parameter Type = 14 | Parameter Length = 8 + 2 * N |
3668 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3669 * | Re-configuration Request Sequence Number |
3670 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3671 * | Stream Number 1 (optional) | Stream Number 2 (optional) |
3672 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3673 * / ...... /
3674 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3675 * | Stream Number N-1 (optional) | Stream Number N (optional) |
3676 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3677 */
3678struct sctp_chunk *sctp_make_strreset_req(
3679 const struct sctp_association *asoc,
3680 __u16 stream_num, __be16 *stream_list,
3681 bool out, bool in)
3682{
3683 __u16 stream_len = stream_num * sizeof(__u16);
3684 struct sctp_strreset_outreq outreq;
3685 struct sctp_strreset_inreq inreq;
3686 struct sctp_chunk *retval;
3687 __u16 outlen, inlen;
3688
3689 outlen = (sizeof(outreq) + stream_len) * out;
3690 inlen = (sizeof(inreq) + stream_len) * in;
3691
3692 retval = sctp_make_reconf(asoc, SCTP_PAD4(outlen) + SCTP_PAD4(inlen));
3693 if (!retval)
3694 return NULL;
3695
3696 if (outlen) {
3697 outreq.param_hdr.type = SCTP_PARAM_RESET_OUT_REQUEST;
3698 outreq.param_hdr.length = htons(outlen);
3699 outreq.request_seq = htonl(asoc->strreset_outseq);
3700 outreq.response_seq = htonl(asoc->strreset_inseq - 1);
3701 outreq.send_reset_at_tsn = htonl(asoc->next_tsn - 1);
3702
3703 sctp_addto_chunk(retval, sizeof(outreq), &outreq);
3704
3705 if (stream_len)
3706 sctp_addto_chunk(retval, stream_len, stream_list);
3707 }
3708
3709 if (inlen) {
3710 inreq.param_hdr.type = SCTP_PARAM_RESET_IN_REQUEST;
3711 inreq.param_hdr.length = htons(inlen);
3712 inreq.request_seq = htonl(asoc->strreset_outseq + out);
3713
3714 sctp_addto_chunk(retval, sizeof(inreq), &inreq);
3715
3716 if (stream_len)
3717 sctp_addto_chunk(retval, stream_len, stream_list);
3718 }
3719
3720 return retval;
3721}
3722
3723/* RE-CONFIG 4.3 (SSN/TSN RESET ALL)
3724 * 0 1 2 3
3725 * 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
3726 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3727 * | Parameter Type = 15 | Parameter Length = 8 |
3728 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3729 * | Re-configuration Request Sequence Number |
3730 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3731 */
3732struct sctp_chunk *sctp_make_strreset_tsnreq(
3733 const struct sctp_association *asoc)
3734{
3735 struct sctp_strreset_tsnreq tsnreq;
3736 __u16 length = sizeof(tsnreq);
3737 struct sctp_chunk *retval;
3738
3739 retval = sctp_make_reconf(asoc, length);
3740 if (!retval)
3741 return NULL;
3742
3743 tsnreq.param_hdr.type = SCTP_PARAM_RESET_TSN_REQUEST;
3744 tsnreq.param_hdr.length = htons(length);
3745 tsnreq.request_seq = htonl(asoc->strreset_outseq);
3746
3747 sctp_addto_chunk(retval, sizeof(tsnreq), &tsnreq);
3748
3749 return retval;
3750}
3751
3752/* RE-CONFIG 4.5/4.6 (ADD STREAM)
3753 * 0 1 2 3
3754 * 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
3755 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3756 * | Parameter Type = 17 | Parameter Length = 12 |
3757 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3758 * | Re-configuration Request Sequence Number |
3759 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3760 * | Number of new streams | Reserved |
3761 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3762 */
3763struct sctp_chunk *sctp_make_strreset_addstrm(
3764 const struct sctp_association *asoc,
3765 __u16 out, __u16 in)
3766{
3767 struct sctp_strreset_addstrm addstrm;
3768 __u16 size = sizeof(addstrm);
3769 struct sctp_chunk *retval;
3770
3771 retval = sctp_make_reconf(asoc, (!!out + !!in) * size);
3772 if (!retval)
3773 return NULL;
3774
3775 if (out) {
3776 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_OUT_STREAMS;
3777 addstrm.param_hdr.length = htons(size);
3778 addstrm.number_of_streams = htons(out);
3779 addstrm.request_seq = htonl(asoc->strreset_outseq);
3780 addstrm.reserved = 0;
3781
3782 sctp_addto_chunk(retval, size, &addstrm);
3783 }
3784
3785 if (in) {
3786 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_IN_STREAMS;
3787 addstrm.param_hdr.length = htons(size);
3788 addstrm.number_of_streams = htons(in);
3789 addstrm.request_seq = htonl(asoc->strreset_outseq + !!out);
3790 addstrm.reserved = 0;
3791
3792 sctp_addto_chunk(retval, size, &addstrm);
3793 }
3794
3795 return retval;
3796}
3797
3798/* RE-CONFIG 4.4 (RESP)
3799 * 0 1 2 3
3800 * 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
3801 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3802 * | Parameter Type = 16 | Parameter Length |
3803 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3804 * | Re-configuration Response Sequence Number |
3805 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3806 * | Result |
3807 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3808 */
3809struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc,
3810 __u32 result, __u32 sn)
3811{
3812 struct sctp_strreset_resp resp;
3813 __u16 length = sizeof(resp);
3814 struct sctp_chunk *retval;
3815
3816 retval = sctp_make_reconf(asoc, length);
3817 if (!retval)
3818 return NULL;
3819
3820 resp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE;
3821 resp.param_hdr.length = htons(length);
3822 resp.response_seq = htonl(sn);
3823 resp.result = htonl(result);
3824
3825 sctp_addto_chunk(retval, sizeof(resp), &resp);
3826
3827 return retval;
3828}
3829
3830/* RE-CONFIG 4.4 OPTIONAL (TSNRESP)
3831 * 0 1 2 3
3832 * 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
3833 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3834 * | Parameter Type = 16 | Parameter Length |
3835 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3836 * | Re-configuration Response Sequence Number |
3837 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3838 * | Result |
3839 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3840 * | Sender's Next TSN (optional) |
3841 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3842 * | Receiver's Next TSN (optional) |
3843 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3844 */
3845struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc,
3846 __u32 result, __u32 sn,
3847 __u32 sender_tsn,
3848 __u32 receiver_tsn)
3849{
3850 struct sctp_strreset_resptsn tsnresp;
3851 __u16 length = sizeof(tsnresp);
3852 struct sctp_chunk *retval;
3853
3854 retval = sctp_make_reconf(asoc, length);
3855 if (!retval)
3856 return NULL;
3857
3858 tsnresp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE;
3859 tsnresp.param_hdr.length = htons(length);
3860
3861 tsnresp.response_seq = htonl(sn);
3862 tsnresp.result = htonl(result);
3863 tsnresp.senders_next_tsn = htonl(sender_tsn);
3864 tsnresp.receivers_next_tsn = htonl(receiver_tsn);
3865
3866 sctp_addto_chunk(retval, sizeof(tsnresp), &tsnresp);
3867
3868 return retval;
3869}
3870
3871bool sctp_verify_reconf(const struct sctp_association *asoc,
3872 struct sctp_chunk *chunk,
3873 struct sctp_paramhdr **errp)
3874{
3875 struct sctp_reconf_chunk *hdr;
3876 union sctp_params param;
3877 __be16 last = 0;
3878 __u16 cnt = 0;
3879
3880 hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr;
3881 sctp_walk_params(param, hdr) {
3882 __u16 length = ntohs(param.p->length);
3883
3884 *errp = param.p;
3885 if (cnt++ > 2)
3886 return false;
3887 switch (param.p->type) {
3888 case SCTP_PARAM_RESET_OUT_REQUEST:
3889 if (length < sizeof(struct sctp_strreset_outreq) ||
3890 (last && last != SCTP_PARAM_RESET_RESPONSE &&
3891 last != SCTP_PARAM_RESET_IN_REQUEST))
3892 return false;
3893 break;
3894 case SCTP_PARAM_RESET_IN_REQUEST:
3895 if (length < sizeof(struct sctp_strreset_inreq) ||
3896 (last && last != SCTP_PARAM_RESET_OUT_REQUEST))
3897 return false;
3898 break;
3899 case SCTP_PARAM_RESET_RESPONSE:
3900 if ((length != sizeof(struct sctp_strreset_resp) &&
3901 length != sizeof(struct sctp_strreset_resptsn)) ||
3902 (last && last != SCTP_PARAM_RESET_RESPONSE &&
3903 last != SCTP_PARAM_RESET_OUT_REQUEST))
3904 return false;
3905 break;
3906 case SCTP_PARAM_RESET_TSN_REQUEST:
3907 if (length !=
3908 sizeof(struct sctp_strreset_tsnreq) || last)
3909 return false;
3910 break;
3911 case SCTP_PARAM_RESET_ADD_IN_STREAMS:
3912 if (length != sizeof(struct sctp_strreset_addstrm) ||
3913 (last && last != SCTP_PARAM_RESET_ADD_OUT_STREAMS))
3914 return false;
3915 break;
3916 case SCTP_PARAM_RESET_ADD_OUT_STREAMS:
3917 if (length != sizeof(struct sctp_strreset_addstrm) ||
3918 (last && last != SCTP_PARAM_RESET_ADD_IN_STREAMS))
3919 return false;
3920 break;
3921 default:
3922 return false;
3923 }
3924
3925 last = param.p->type;
3926 }
3927
3928 return true;
3929}
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 struct sctp_cookie_param *sctp_pack_cookie(
73 const struct sctp_endpoint *ep,
74 const struct sctp_association *asoc,
75 const struct sctp_chunk *init_chunk,
76 int *cookie_len,
77 const __u8 *raw_addrs, int addrs_len);
78static int sctp_process_param(struct sctp_association *asoc,
79 union sctp_params param,
80 const union sctp_addr *peer_addr,
81 gfp_t gfp);
82static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
83 const void *data);
84static void *sctp_addto_chunk_fixed(struct sctp_chunk *, int len,
85 const void *data);
86
87/* Control chunk destructor */
88static void sctp_control_release_owner(struct sk_buff *skb)
89{
90 struct sctp_chunk *chunk = skb_shinfo(skb)->destructor_arg;
91
92 if (chunk->shkey) {
93 struct sctp_shared_key *shkey = chunk->shkey;
94 struct sctp_association *asoc = chunk->asoc;
95
96 /* refcnt == 2 and !list_empty mean after this release, it's
97 * not being used anywhere, and it's time to notify userland
98 * that this shkey can be freed if it's been deactivated.
99 */
100 if (shkey->deactivated && !list_empty(&shkey->key_list) &&
101 refcount_read(&shkey->refcnt) == 2) {
102 struct sctp_ulpevent *ev;
103
104 ev = sctp_ulpevent_make_authkey(asoc, shkey->key_id,
105 SCTP_AUTH_FREE_KEY,
106 GFP_KERNEL);
107 if (ev)
108 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
109 }
110 sctp_auth_shkey_release(chunk->shkey);
111 }
112}
113
114static void sctp_control_set_owner_w(struct sctp_chunk *chunk)
115{
116 struct sctp_association *asoc = chunk->asoc;
117 struct sk_buff *skb = chunk->skb;
118
119 /* TODO: properly account for control chunks.
120 * To do it right we'll need:
121 * 1) endpoint if association isn't known.
122 * 2) proper memory accounting.
123 *
124 * For now don't do anything for now.
125 */
126 if (chunk->auth) {
127 chunk->shkey = asoc->shkey;
128 sctp_auth_shkey_hold(chunk->shkey);
129 }
130 skb->sk = asoc ? asoc->base.sk : NULL;
131 skb_shinfo(skb)->destructor_arg = chunk;
132 skb->destructor = sctp_control_release_owner;
133}
134
135/* What was the inbound interface for this chunk? */
136int sctp_chunk_iif(const struct sctp_chunk *chunk)
137{
138 struct sk_buff *skb = chunk->skb;
139
140 return SCTP_INPUT_CB(skb)->af->skb_iif(skb);
141}
142
143/* RFC 2960 3.3.2 Initiation (INIT) (1)
144 *
145 * Note 2: The ECN capable field is reserved for future use of
146 * Explicit Congestion Notification.
147 */
148static const struct sctp_paramhdr ecap_param = {
149 SCTP_PARAM_ECN_CAPABLE,
150 cpu_to_be16(sizeof(struct sctp_paramhdr)),
151};
152static const struct sctp_paramhdr prsctp_param = {
153 SCTP_PARAM_FWD_TSN_SUPPORT,
154 cpu_to_be16(sizeof(struct sctp_paramhdr)),
155};
156
157/* A helper to initialize an op error inside a
158 * provided chunk, as most cause codes will be embedded inside an
159 * abort chunk.
160 */
161void sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code,
162 size_t paylen)
163{
164 struct sctp_errhdr err;
165 __u16 len;
166
167 /* Cause code constants are now defined in network order. */
168 err.cause = cause_code;
169 len = sizeof(err) + paylen;
170 err.length = htons(len);
171 chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(err), &err);
172}
173
174/* A helper to initialize an op error inside a
175 * provided chunk, as most cause codes will be embedded inside an
176 * abort chunk. Differs from sctp_init_cause in that it won't oops
177 * if there isn't enough space in the op error chunk
178 */
179static int sctp_init_cause_fixed(struct sctp_chunk *chunk, __be16 cause_code,
180 size_t paylen)
181{
182 struct sctp_errhdr err;
183 __u16 len;
184
185 /* Cause code constants are now defined in network order. */
186 err.cause = cause_code;
187 len = sizeof(err) + paylen;
188 err.length = htons(len);
189
190 if (skb_tailroom(chunk->skb) < len)
191 return -ENOSPC;
192
193 chunk->subh.err_hdr = sctp_addto_chunk_fixed(chunk, sizeof(err), &err);
194
195 return 0;
196}
197/* 3.3.2 Initiation (INIT) (1)
198 *
199 * This chunk is used to initiate a SCTP association between two
200 * endpoints. The format of the INIT chunk is shown below:
201 *
202 * 0 1 2 3
203 * 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
204 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
205 * | Type = 1 | Chunk Flags | Chunk Length |
206 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
207 * | Initiate Tag |
208 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
209 * | Advertised Receiver Window Credit (a_rwnd) |
210 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
211 * | Number of Outbound Streams | Number of Inbound Streams |
212 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
213 * | Initial TSN |
214 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
215 * \ \
216 * / Optional/Variable-Length Parameters /
217 * \ \
218 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
219 *
220 *
221 * The INIT chunk contains the following parameters. Unless otherwise
222 * noted, each parameter MUST only be included once in the INIT chunk.
223 *
224 * Fixed Parameters Status
225 * ----------------------------------------------
226 * Initiate Tag Mandatory
227 * Advertised Receiver Window Credit Mandatory
228 * Number of Outbound Streams Mandatory
229 * Number of Inbound Streams Mandatory
230 * Initial TSN Mandatory
231 *
232 * Variable Parameters Status Type Value
233 * -------------------------------------------------------------
234 * IPv4 Address (Note 1) Optional 5
235 * IPv6 Address (Note 1) Optional 6
236 * Cookie Preservative Optional 9
237 * Reserved for ECN Capable (Note 2) Optional 32768 (0x8000)
238 * Host Name Address (Note 3) Optional 11
239 * Supported Address Types (Note 4) Optional 12
240 */
241struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc,
242 const struct sctp_bind_addr *bp,
243 gfp_t gfp, int vparam_len)
244{
245 struct net *net = sock_net(asoc->base.sk);
246 struct sctp_supported_ext_param ext_param;
247 struct sctp_adaptation_ind_param aiparam;
248 struct sctp_paramhdr *auth_chunks = NULL;
249 struct sctp_paramhdr *auth_hmacs = NULL;
250 struct sctp_supported_addrs_param sat;
251 struct sctp_endpoint *ep = asoc->ep;
252 struct sctp_chunk *retval = NULL;
253 int num_types, addrs_len = 0;
254 struct sctp_inithdr init;
255 union sctp_params addrs;
256 struct sctp_sock *sp;
257 __u8 extensions[5];
258 size_t chunksize;
259 __be16 types[2];
260 int num_ext = 0;
261
262 /* RFC 2960 3.3.2 Initiation (INIT) (1)
263 *
264 * Note 1: The INIT chunks can contain multiple addresses that
265 * can be IPv4 and/or IPv6 in any combination.
266 */
267
268 /* Convert the provided bind address list to raw format. */
269 addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp);
270
271 init.init_tag = htonl(asoc->c.my_vtag);
272 init.a_rwnd = htonl(asoc->rwnd);
273 init.num_outbound_streams = htons(asoc->c.sinit_num_ostreams);
274 init.num_inbound_streams = htons(asoc->c.sinit_max_instreams);
275 init.initial_tsn = htonl(asoc->c.initial_tsn);
276
277 /* How many address types are needed? */
278 sp = sctp_sk(asoc->base.sk);
279 num_types = sp->pf->supported_addrs(sp, types);
280
281 chunksize = sizeof(init) + addrs_len;
282 chunksize += SCTP_PAD4(SCTP_SAT_LEN(num_types));
283 chunksize += sizeof(ecap_param);
284
285 if (asoc->prsctp_enable)
286 chunksize += sizeof(prsctp_param);
287
288 /* ADDIP: Section 4.2.7:
289 * An implementation supporting this extension [ADDIP] MUST list
290 * the ASCONF,the ASCONF-ACK, and the AUTH chunks in its INIT and
291 * INIT-ACK parameters.
292 */
293 if (net->sctp.addip_enable) {
294 extensions[num_ext] = SCTP_CID_ASCONF;
295 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
296 num_ext += 2;
297 }
298
299 if (asoc->reconf_enable) {
300 extensions[num_ext] = SCTP_CID_RECONF;
301 num_ext += 1;
302 }
303
304 if (sp->adaptation_ind)
305 chunksize += sizeof(aiparam);
306
307 if (sp->strm_interleave) {
308 extensions[num_ext] = SCTP_CID_I_DATA;
309 num_ext += 1;
310 }
311
312 chunksize += vparam_len;
313
314 /* Account for AUTH related parameters */
315 if (ep->auth_enable) {
316 /* Add random parameter length*/
317 chunksize += sizeof(asoc->c.auth_random);
318
319 /* Add HMACS parameter length if any were defined */
320 auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs;
321 if (auth_hmacs->length)
322 chunksize += SCTP_PAD4(ntohs(auth_hmacs->length));
323 else
324 auth_hmacs = NULL;
325
326 /* Add CHUNKS parameter length */
327 auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks;
328 if (auth_chunks->length)
329 chunksize += SCTP_PAD4(ntohs(auth_chunks->length));
330 else
331 auth_chunks = NULL;
332
333 extensions[num_ext] = SCTP_CID_AUTH;
334 num_ext += 1;
335 }
336
337 /* If we have any extensions to report, account for that */
338 if (num_ext)
339 chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext);
340
341 /* RFC 2960 3.3.2 Initiation (INIT) (1)
342 *
343 * Note 3: An INIT chunk MUST NOT contain more than one Host
344 * Name address parameter. Moreover, the sender of the INIT
345 * MUST NOT combine any other address types with the Host Name
346 * address in the INIT. The receiver of INIT MUST ignore any
347 * other address types if the Host Name address parameter is
348 * present in the received INIT chunk.
349 *
350 * PLEASE DO NOT FIXME [This version does not support Host Name.]
351 */
352
353 retval = sctp_make_control(asoc, SCTP_CID_INIT, 0, chunksize, gfp);
354 if (!retval)
355 goto nodata;
356
357 retval->subh.init_hdr =
358 sctp_addto_chunk(retval, sizeof(init), &init);
359 retval->param_hdr.v =
360 sctp_addto_chunk(retval, addrs_len, addrs.v);
361
362 /* RFC 2960 3.3.2 Initiation (INIT) (1)
363 *
364 * Note 4: This parameter, when present, specifies all the
365 * address types the sending endpoint can support. The absence
366 * of this parameter indicates that the sending endpoint can
367 * support any address type.
368 */
369 sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES;
370 sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types));
371 sctp_addto_chunk(retval, sizeof(sat), &sat);
372 sctp_addto_chunk(retval, num_types * sizeof(__u16), &types);
373
374 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
375
376 /* Add the supported extensions parameter. Be nice and add this
377 * fist before addiding the parameters for the extensions themselves
378 */
379 if (num_ext) {
380 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
381 ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext);
382 sctp_addto_chunk(retval, sizeof(ext_param), &ext_param);
383 sctp_addto_param(retval, num_ext, extensions);
384 }
385
386 if (asoc->prsctp_enable)
387 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
388
389 if (sp->adaptation_ind) {
390 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
391 aiparam.param_hdr.length = htons(sizeof(aiparam));
392 aiparam.adaptation_ind = htonl(sp->adaptation_ind);
393 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
394 }
395
396 /* Add SCTP-AUTH chunks to the parameter list */
397 if (ep->auth_enable) {
398 sctp_addto_chunk(retval, sizeof(asoc->c.auth_random),
399 asoc->c.auth_random);
400 if (auth_hmacs)
401 sctp_addto_chunk(retval, ntohs(auth_hmacs->length),
402 auth_hmacs);
403 if (auth_chunks)
404 sctp_addto_chunk(retval, ntohs(auth_chunks->length),
405 auth_chunks);
406 }
407nodata:
408 kfree(addrs.v);
409 return retval;
410}
411
412struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc,
413 const struct sctp_chunk *chunk,
414 gfp_t gfp, int unkparam_len)
415{
416 struct sctp_supported_ext_param ext_param;
417 struct sctp_adaptation_ind_param aiparam;
418 struct sctp_paramhdr *auth_chunks = NULL;
419 struct sctp_paramhdr *auth_random = NULL;
420 struct sctp_paramhdr *auth_hmacs = NULL;
421 struct sctp_chunk *retval = NULL;
422 struct sctp_cookie_param *cookie;
423 struct sctp_inithdr initack;
424 union sctp_params addrs;
425 struct sctp_sock *sp;
426 __u8 extensions[5];
427 size_t chunksize;
428 int num_ext = 0;
429 int cookie_len;
430 int addrs_len;
431
432 /* Note: there may be no addresses to embed. */
433 addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp);
434
435 initack.init_tag = htonl(asoc->c.my_vtag);
436 initack.a_rwnd = htonl(asoc->rwnd);
437 initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams);
438 initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams);
439 initack.initial_tsn = htonl(asoc->c.initial_tsn);
440
441 /* FIXME: We really ought to build the cookie right
442 * into the packet instead of allocating more fresh memory.
443 */
444 cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len,
445 addrs.v, addrs_len);
446 if (!cookie)
447 goto nomem_cookie;
448
449 /* Calculate the total size of allocation, include the reserved
450 * space for reporting unknown parameters if it is specified.
451 */
452 sp = sctp_sk(asoc->base.sk);
453 chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len;
454
455 /* Tell peer that we'll do ECN only if peer advertised such cap. */
456 if (asoc->peer.ecn_capable)
457 chunksize += sizeof(ecap_param);
458
459 if (asoc->peer.prsctp_capable)
460 chunksize += sizeof(prsctp_param);
461
462 if (asoc->peer.asconf_capable) {
463 extensions[num_ext] = SCTP_CID_ASCONF;
464 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
465 num_ext += 2;
466 }
467
468 if (asoc->peer.reconf_capable) {
469 extensions[num_ext] = SCTP_CID_RECONF;
470 num_ext += 1;
471 }
472
473 if (sp->adaptation_ind)
474 chunksize += sizeof(aiparam);
475
476 if (asoc->intl_enable) {
477 extensions[num_ext] = SCTP_CID_I_DATA;
478 num_ext += 1;
479 }
480
481 if (asoc->peer.auth_capable) {
482 auth_random = (struct sctp_paramhdr *)asoc->c.auth_random;
483 chunksize += ntohs(auth_random->length);
484
485 auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs;
486 if (auth_hmacs->length)
487 chunksize += SCTP_PAD4(ntohs(auth_hmacs->length));
488 else
489 auth_hmacs = NULL;
490
491 auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks;
492 if (auth_chunks->length)
493 chunksize += SCTP_PAD4(ntohs(auth_chunks->length));
494 else
495 auth_chunks = NULL;
496
497 extensions[num_ext] = SCTP_CID_AUTH;
498 num_ext += 1;
499 }
500
501 if (num_ext)
502 chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext);
503
504 /* Now allocate and fill out the chunk. */
505 retval = sctp_make_control(asoc, SCTP_CID_INIT_ACK, 0, chunksize, gfp);
506 if (!retval)
507 goto nomem_chunk;
508
509 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
510 *
511 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
512 * HEARTBEAT ACK, * etc.) to the same destination transport
513 * address from which it received the DATA or control chunk
514 * to which it is replying.
515 *
516 * [INIT ACK back to where the INIT came from.]
517 */
518 retval->transport = chunk->transport;
519
520 retval->subh.init_hdr =
521 sctp_addto_chunk(retval, sizeof(initack), &initack);
522 retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v);
523 sctp_addto_chunk(retval, cookie_len, cookie);
524 if (asoc->peer.ecn_capable)
525 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
526 if (num_ext) {
527 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
528 ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext);
529 sctp_addto_chunk(retval, sizeof(ext_param), &ext_param);
530 sctp_addto_param(retval, num_ext, extensions);
531 }
532 if (asoc->peer.prsctp_capable)
533 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
534
535 if (sp->adaptation_ind) {
536 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
537 aiparam.param_hdr.length = htons(sizeof(aiparam));
538 aiparam.adaptation_ind = htonl(sp->adaptation_ind);
539 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
540 }
541
542 if (asoc->peer.auth_capable) {
543 sctp_addto_chunk(retval, ntohs(auth_random->length),
544 auth_random);
545 if (auth_hmacs)
546 sctp_addto_chunk(retval, ntohs(auth_hmacs->length),
547 auth_hmacs);
548 if (auth_chunks)
549 sctp_addto_chunk(retval, ntohs(auth_chunks->length),
550 auth_chunks);
551 }
552
553 /* We need to remove the const qualifier at this point. */
554 retval->asoc = (struct sctp_association *) asoc;
555
556nomem_chunk:
557 kfree(cookie);
558nomem_cookie:
559 kfree(addrs.v);
560 return retval;
561}
562
563/* 3.3.11 Cookie Echo (COOKIE ECHO) (10):
564 *
565 * This chunk is used only during the initialization of an association.
566 * It is sent by the initiator of an association to its peer to complete
567 * the initialization process. This chunk MUST precede any DATA chunk
568 * sent within the association, but MAY be bundled with one or more DATA
569 * chunks in the same packet.
570 *
571 * 0 1 2 3
572 * 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
573 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
574 * | Type = 10 |Chunk Flags | Length |
575 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
576 * / Cookie /
577 * \ \
578 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
579 *
580 * Chunk Flags: 8 bit
581 *
582 * Set to zero on transmit and ignored on receipt.
583 *
584 * Length: 16 bits (unsigned integer)
585 *
586 * Set to the size of the chunk in bytes, including the 4 bytes of
587 * the chunk header and the size of the Cookie.
588 *
589 * Cookie: variable size
590 *
591 * This field must contain the exact cookie received in the
592 * State Cookie parameter from the previous INIT ACK.
593 *
594 * An implementation SHOULD make the cookie as small as possible
595 * to insure interoperability.
596 */
597struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc,
598 const struct sctp_chunk *chunk)
599{
600 struct sctp_chunk *retval;
601 int cookie_len;
602 void *cookie;
603
604 cookie = asoc->peer.cookie;
605 cookie_len = asoc->peer.cookie_len;
606
607 /* Build a cookie echo chunk. */
608 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ECHO, 0,
609 cookie_len, GFP_ATOMIC);
610 if (!retval)
611 goto nodata;
612 retval->subh.cookie_hdr =
613 sctp_addto_chunk(retval, cookie_len, cookie);
614
615 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
616 *
617 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
618 * HEARTBEAT ACK, * etc.) to the same destination transport
619 * address from which it * received the DATA or control chunk
620 * to which it is replying.
621 *
622 * [COOKIE ECHO back to where the INIT ACK came from.]
623 */
624 if (chunk)
625 retval->transport = chunk->transport;
626
627nodata:
628 return retval;
629}
630
631/* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11):
632 *
633 * This chunk is used only during the initialization of an
634 * association. It is used to acknowledge the receipt of a COOKIE
635 * ECHO chunk. This chunk MUST precede any DATA or SACK chunk sent
636 * within the association, but MAY be bundled with one or more DATA
637 * chunks or SACK chunk in the same SCTP packet.
638 *
639 * 0 1 2 3
640 * 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
641 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
642 * | Type = 11 |Chunk Flags | Length = 4 |
643 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
644 *
645 * Chunk Flags: 8 bits
646 *
647 * Set to zero on transmit and ignored on receipt.
648 */
649struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc,
650 const struct sctp_chunk *chunk)
651{
652 struct sctp_chunk *retval;
653
654 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ACK, 0, 0, GFP_ATOMIC);
655
656 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
657 *
658 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
659 * HEARTBEAT ACK, * etc.) to the same destination transport
660 * address from which it * received the DATA or control chunk
661 * to which it is replying.
662 *
663 * [COOKIE ACK back to where the COOKIE ECHO came from.]
664 */
665 if (retval && chunk)
666 retval->transport = chunk->transport;
667
668 return retval;
669}
670
671/*
672 * Appendix A: Explicit Congestion Notification:
673 * CWR:
674 *
675 * RFC 2481 details a specific bit for a sender to send in the header of
676 * its next outbound TCP segment to indicate to its peer that it has
677 * reduced its congestion window. This is termed the CWR bit. For
678 * SCTP the same indication is made by including the CWR chunk.
679 * This chunk contains one data element, i.e. the TSN number that
680 * was sent in the ECNE chunk. This element represents the lowest
681 * TSN number in the datagram that was originally marked with the
682 * CE bit.
683 *
684 * 0 1 2 3
685 * 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
686 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
687 * | Chunk Type=13 | Flags=00000000| Chunk Length = 8 |
688 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
689 * | Lowest TSN Number |
690 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
691 *
692 * Note: The CWR is considered a Control chunk.
693 */
694struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc,
695 const __u32 lowest_tsn,
696 const struct sctp_chunk *chunk)
697{
698 struct sctp_chunk *retval;
699 struct sctp_cwrhdr cwr;
700
701 cwr.lowest_tsn = htonl(lowest_tsn);
702 retval = sctp_make_control(asoc, SCTP_CID_ECN_CWR, 0,
703 sizeof(cwr), GFP_ATOMIC);
704
705 if (!retval)
706 goto nodata;
707
708 retval->subh.ecn_cwr_hdr =
709 sctp_addto_chunk(retval, sizeof(cwr), &cwr);
710
711 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
712 *
713 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
714 * HEARTBEAT ACK, * etc.) to the same destination transport
715 * address from which it * received the DATA or control chunk
716 * to which it is replying.
717 *
718 * [Report a reduced congestion window back to where the ECNE
719 * came from.]
720 */
721 if (chunk)
722 retval->transport = chunk->transport;
723
724nodata:
725 return retval;
726}
727
728/* Make an ECNE chunk. This is a congestion experienced report. */
729struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc,
730 const __u32 lowest_tsn)
731{
732 struct sctp_chunk *retval;
733 struct sctp_ecnehdr ecne;
734
735 ecne.lowest_tsn = htonl(lowest_tsn);
736 retval = sctp_make_control(asoc, SCTP_CID_ECN_ECNE, 0,
737 sizeof(ecne), GFP_ATOMIC);
738 if (!retval)
739 goto nodata;
740 retval->subh.ecne_hdr =
741 sctp_addto_chunk(retval, sizeof(ecne), &ecne);
742
743nodata:
744 return retval;
745}
746
747/* Make a DATA chunk for the given association from the provided
748 * parameters. However, do not populate the data payload.
749 */
750struct sctp_chunk *sctp_make_datafrag_empty(const struct sctp_association *asoc,
751 const struct sctp_sndrcvinfo *sinfo,
752 int len, __u8 flags, gfp_t gfp)
753{
754 struct sctp_chunk *retval;
755 struct sctp_datahdr dp;
756
757 /* We assign the TSN as LATE as possible, not here when
758 * creating the chunk.
759 */
760 memset(&dp, 0, sizeof(dp));
761 dp.ppid = sinfo->sinfo_ppid;
762 dp.stream = htons(sinfo->sinfo_stream);
763
764 /* Set the flags for an unordered send. */
765 if (sinfo->sinfo_flags & SCTP_UNORDERED)
766 flags |= SCTP_DATA_UNORDERED;
767
768 retval = sctp_make_data(asoc, flags, sizeof(dp) + len, gfp);
769 if (!retval)
770 return NULL;
771
772 retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp);
773 memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo));
774
775 return retval;
776}
777
778/* Create a selective ackowledgement (SACK) for the given
779 * association. This reports on which TSN's we've seen to date,
780 * including duplicates and gaps.
781 */
782struct sctp_chunk *sctp_make_sack(const struct sctp_association *asoc)
783{
784 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
785 struct sctp_association *aptr = (struct sctp_association *)asoc;
786 struct sctp_gap_ack_block gabs[SCTP_MAX_GABS];
787 __u16 num_gabs, num_dup_tsns;
788 struct sctp_transport *trans;
789 struct sctp_chunk *retval;
790 struct sctp_sackhdr sack;
791 __u32 ctsn;
792 int len;
793
794 memset(gabs, 0, sizeof(gabs));
795 ctsn = sctp_tsnmap_get_ctsn(map);
796
797 pr_debug("%s: sackCTSNAck sent:0x%x\n", __func__, ctsn);
798
799 /* How much room is needed in the chunk? */
800 num_gabs = sctp_tsnmap_num_gabs(map, gabs);
801 num_dup_tsns = sctp_tsnmap_num_dups(map);
802
803 /* Initialize the SACK header. */
804 sack.cum_tsn_ack = htonl(ctsn);
805 sack.a_rwnd = htonl(asoc->a_rwnd);
806 sack.num_gap_ack_blocks = htons(num_gabs);
807 sack.num_dup_tsns = htons(num_dup_tsns);
808
809 len = sizeof(sack)
810 + sizeof(struct sctp_gap_ack_block) * num_gabs
811 + sizeof(__u32) * num_dup_tsns;
812
813 /* Create the chunk. */
814 retval = sctp_make_control(asoc, SCTP_CID_SACK, 0, len, GFP_ATOMIC);
815 if (!retval)
816 goto nodata;
817
818 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
819 *
820 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
821 * HEARTBEAT ACK, etc.) to the same destination transport
822 * address from which it received the DATA or control chunk to
823 * which it is replying. This rule should also be followed if
824 * the endpoint is bundling DATA chunks together with the
825 * reply chunk.
826 *
827 * However, when acknowledging multiple DATA chunks received
828 * in packets from different source addresses in a single
829 * SACK, the SACK chunk may be transmitted to one of the
830 * destination transport addresses from which the DATA or
831 * control chunks being acknowledged were received.
832 *
833 * [BUG: We do not implement the following paragraph.
834 * Perhaps we should remember the last transport we used for a
835 * SACK and avoid that (if possible) if we have seen any
836 * duplicates. --piggy]
837 *
838 * When a receiver of a duplicate DATA chunk sends a SACK to a
839 * multi- homed endpoint it MAY be beneficial to vary the
840 * destination address and not use the source address of the
841 * DATA chunk. The reason being that receiving a duplicate
842 * from a multi-homed endpoint might indicate that the return
843 * path (as specified in the source address of the DATA chunk)
844 * for the SACK is broken.
845 *
846 * [Send to the address from which we last received a DATA chunk.]
847 */
848 retval->transport = asoc->peer.last_data_from;
849
850 retval->subh.sack_hdr =
851 sctp_addto_chunk(retval, sizeof(sack), &sack);
852
853 /* Add the gap ack block information. */
854 if (num_gabs)
855 sctp_addto_chunk(retval, sizeof(__u32) * num_gabs,
856 gabs);
857
858 /* Add the duplicate TSN information. */
859 if (num_dup_tsns) {
860 aptr->stats.idupchunks += num_dup_tsns;
861 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns,
862 sctp_tsnmap_get_dups(map));
863 }
864 /* Once we have a sack generated, check to see what our sack
865 * generation is, if its 0, reset the transports to 0, and reset
866 * the association generation to 1
867 *
868 * The idea is that zero is never used as a valid generation for the
869 * association so no transport will match after a wrap event like this,
870 * Until the next sack
871 */
872 if (++aptr->peer.sack_generation == 0) {
873 list_for_each_entry(trans, &asoc->peer.transport_addr_list,
874 transports)
875 trans->sack_generation = 0;
876 aptr->peer.sack_generation = 1;
877 }
878nodata:
879 return retval;
880}
881
882/* Make a SHUTDOWN chunk. */
883struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc,
884 const struct sctp_chunk *chunk)
885{
886 struct sctp_shutdownhdr shut;
887 struct sctp_chunk *retval;
888 __u32 ctsn;
889
890 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
891 shut.cum_tsn_ack = htonl(ctsn);
892
893 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN, 0,
894 sizeof(shut), GFP_ATOMIC);
895 if (!retval)
896 goto nodata;
897
898 retval->subh.shutdown_hdr =
899 sctp_addto_chunk(retval, sizeof(shut), &shut);
900
901 if (chunk)
902 retval->transport = chunk->transport;
903nodata:
904 return retval;
905}
906
907struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc,
908 const struct sctp_chunk *chunk)
909{
910 struct sctp_chunk *retval;
911
912 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0,
913 GFP_ATOMIC);
914
915 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
916 *
917 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
918 * HEARTBEAT ACK, * etc.) to the same destination transport
919 * address from which it * received the DATA or control chunk
920 * to which it is replying.
921 *
922 * [ACK back to where the SHUTDOWN came from.]
923 */
924 if (retval && chunk)
925 retval->transport = chunk->transport;
926
927 return retval;
928}
929
930struct sctp_chunk *sctp_make_shutdown_complete(
931 const struct sctp_association *asoc,
932 const struct sctp_chunk *chunk)
933{
934 struct sctp_chunk *retval;
935 __u8 flags = 0;
936
937 /* Set the T-bit if we have no association (vtag will be
938 * reflected)
939 */
940 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T;
941
942 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags,
943 0, GFP_ATOMIC);
944
945 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
946 *
947 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
948 * HEARTBEAT ACK, * etc.) to the same destination transport
949 * address from which it * received the DATA or control chunk
950 * to which it is replying.
951 *
952 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK
953 * came from.]
954 */
955 if (retval && chunk)
956 retval->transport = chunk->transport;
957
958 return retval;
959}
960
961/* Create an ABORT. Note that we set the T bit if we have no
962 * association, except when responding to an INIT (sctpimpguide 2.41).
963 */
964struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc,
965 const struct sctp_chunk *chunk,
966 const size_t hint)
967{
968 struct sctp_chunk *retval;
969 __u8 flags = 0;
970
971 /* Set the T-bit if we have no association and 'chunk' is not
972 * an INIT (vtag will be reflected).
973 */
974 if (!asoc) {
975 if (chunk && chunk->chunk_hdr &&
976 chunk->chunk_hdr->type == SCTP_CID_INIT)
977 flags = 0;
978 else
979 flags = SCTP_CHUNK_FLAG_T;
980 }
981
982 retval = sctp_make_control(asoc, SCTP_CID_ABORT, flags, hint,
983 GFP_ATOMIC);
984
985 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
986 *
987 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
988 * HEARTBEAT ACK, * etc.) to the same destination transport
989 * address from which it * received the DATA or control chunk
990 * to which it is replying.
991 *
992 * [ABORT back to where the offender came from.]
993 */
994 if (retval && chunk)
995 retval->transport = chunk->transport;
996
997 return retval;
998}
999
1000/* Helper to create ABORT with a NO_USER_DATA error. */
1001struct sctp_chunk *sctp_make_abort_no_data(
1002 const struct sctp_association *asoc,
1003 const struct sctp_chunk *chunk,
1004 __u32 tsn)
1005{
1006 struct sctp_chunk *retval;
1007 __be32 payload;
1008
1009 retval = sctp_make_abort(asoc, chunk,
1010 sizeof(struct sctp_errhdr) + sizeof(tsn));
1011
1012 if (!retval)
1013 goto no_mem;
1014
1015 /* Put the tsn back into network byte order. */
1016 payload = htonl(tsn);
1017 sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload));
1018 sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload);
1019
1020 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
1021 *
1022 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1023 * HEARTBEAT ACK, * etc.) to the same destination transport
1024 * address from which it * received the DATA or control chunk
1025 * to which it is replying.
1026 *
1027 * [ABORT back to where the offender came from.]
1028 */
1029 if (chunk)
1030 retval->transport = chunk->transport;
1031
1032no_mem:
1033 return retval;
1034}
1035
1036/* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */
1037struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc,
1038 struct msghdr *msg,
1039 size_t paylen)
1040{
1041 struct sctp_chunk *retval;
1042 void *payload = NULL;
1043 int err;
1044
1045 retval = sctp_make_abort(asoc, NULL,
1046 sizeof(struct sctp_errhdr) + paylen);
1047 if (!retval)
1048 goto err_chunk;
1049
1050 if (paylen) {
1051 /* Put the msg_iov together into payload. */
1052 payload = kmalloc(paylen, GFP_KERNEL);
1053 if (!payload)
1054 goto err_payload;
1055
1056 err = memcpy_from_msg(payload, msg, paylen);
1057 if (err < 0)
1058 goto err_copy;
1059 }
1060
1061 sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen);
1062 sctp_addto_chunk(retval, paylen, payload);
1063
1064 if (paylen)
1065 kfree(payload);
1066
1067 return retval;
1068
1069err_copy:
1070 kfree(payload);
1071err_payload:
1072 sctp_chunk_free(retval);
1073 retval = NULL;
1074err_chunk:
1075 return retval;
1076}
1077
1078/* Append bytes to the end of a parameter. Will panic if chunk is not big
1079 * enough.
1080 */
1081static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
1082 const void *data)
1083{
1084 int chunklen = ntohs(chunk->chunk_hdr->length);
1085 void *target;
1086
1087 target = skb_put(chunk->skb, len);
1088
1089 if (data)
1090 memcpy(target, data, len);
1091 else
1092 memset(target, 0, len);
1093
1094 /* Adjust the chunk length field. */
1095 chunk->chunk_hdr->length = htons(chunklen + len);
1096 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1097
1098 return target;
1099}
1100
1101/* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */
1102struct sctp_chunk *sctp_make_abort_violation(
1103 const struct sctp_association *asoc,
1104 const struct sctp_chunk *chunk,
1105 const __u8 *payload,
1106 const size_t paylen)
1107{
1108 struct sctp_chunk *retval;
1109 struct sctp_paramhdr phdr;
1110
1111 retval = sctp_make_abort(asoc, chunk, sizeof(struct sctp_errhdr) +
1112 paylen + sizeof(phdr));
1113 if (!retval)
1114 goto end;
1115
1116 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen +
1117 sizeof(phdr));
1118
1119 phdr.type = htons(chunk->chunk_hdr->type);
1120 phdr.length = chunk->chunk_hdr->length;
1121 sctp_addto_chunk(retval, paylen, payload);
1122 sctp_addto_param(retval, sizeof(phdr), &phdr);
1123
1124end:
1125 return retval;
1126}
1127
1128struct sctp_chunk *sctp_make_violation_paramlen(
1129 const struct sctp_association *asoc,
1130 const struct sctp_chunk *chunk,
1131 struct sctp_paramhdr *param)
1132{
1133 static const char error[] = "The following parameter had invalid length:";
1134 size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr) +
1135 sizeof(*param);
1136 struct sctp_chunk *retval;
1137
1138 retval = sctp_make_abort(asoc, chunk, payload_len);
1139 if (!retval)
1140 goto nodata;
1141
1142 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION,
1143 sizeof(error) + sizeof(*param));
1144 sctp_addto_chunk(retval, sizeof(error), error);
1145 sctp_addto_param(retval, sizeof(*param), param);
1146
1147nodata:
1148 return retval;
1149}
1150
1151struct sctp_chunk *sctp_make_violation_max_retrans(
1152 const struct sctp_association *asoc,
1153 const struct sctp_chunk *chunk)
1154{
1155 static const char error[] = "Association exceeded its max_retrans count";
1156 size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr);
1157 struct sctp_chunk *retval;
1158
1159 retval = sctp_make_abort(asoc, chunk, payload_len);
1160 if (!retval)
1161 goto nodata;
1162
1163 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error));
1164 sctp_addto_chunk(retval, sizeof(error), error);
1165
1166nodata:
1167 return retval;
1168}
1169
1170/* Make a HEARTBEAT chunk. */
1171struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc,
1172 const struct sctp_transport *transport)
1173{
1174 struct sctp_sender_hb_info hbinfo;
1175 struct sctp_chunk *retval;
1176
1177 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT, 0,
1178 sizeof(hbinfo), GFP_ATOMIC);
1179
1180 if (!retval)
1181 goto nodata;
1182
1183 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO;
1184 hbinfo.param_hdr.length = htons(sizeof(hbinfo));
1185 hbinfo.daddr = transport->ipaddr;
1186 hbinfo.sent_at = jiffies;
1187 hbinfo.hb_nonce = transport->hb_nonce;
1188
1189 /* Cast away the 'const', as this is just telling the chunk
1190 * what transport it belongs to.
1191 */
1192 retval->transport = (struct sctp_transport *) transport;
1193 retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo),
1194 &hbinfo);
1195
1196nodata:
1197 return retval;
1198}
1199
1200struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc,
1201 const struct sctp_chunk *chunk,
1202 const void *payload,
1203 const size_t paylen)
1204{
1205 struct sctp_chunk *retval;
1206
1207 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen,
1208 GFP_ATOMIC);
1209 if (!retval)
1210 goto nodata;
1211
1212 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload);
1213
1214 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
1215 *
1216 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1217 * HEARTBEAT ACK, * etc.) to the same destination transport
1218 * address from which it * received the DATA or control chunk
1219 * to which it is replying.
1220 *
1221 * [HBACK back to where the HEARTBEAT came from.]
1222 */
1223 if (chunk)
1224 retval->transport = chunk->transport;
1225
1226nodata:
1227 return retval;
1228}
1229
1230/* Create an Operation Error chunk with the specified space reserved.
1231 * This routine can be used for containing multiple causes in the chunk.
1232 */
1233static struct sctp_chunk *sctp_make_op_error_space(
1234 const struct sctp_association *asoc,
1235 const struct sctp_chunk *chunk,
1236 size_t size)
1237{
1238 struct sctp_chunk *retval;
1239
1240 retval = sctp_make_control(asoc, SCTP_CID_ERROR, 0,
1241 sizeof(struct sctp_errhdr) + size,
1242 GFP_ATOMIC);
1243 if (!retval)
1244 goto nodata;
1245
1246 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
1247 *
1248 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1249 * HEARTBEAT ACK, etc.) to the same destination transport
1250 * address from which it received the DATA or control chunk
1251 * to which it is replying.
1252 *
1253 */
1254 if (chunk)
1255 retval->transport = chunk->transport;
1256
1257nodata:
1258 return retval;
1259}
1260
1261/* Create an Operation Error chunk of a fixed size,
1262 * specifically, max(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT)
1263 * This is a helper function to allocate an error chunk for
1264 * for those invalid parameter codes in which we may not want
1265 * to report all the errors, if the incoming chunk is large
1266 */
1267static inline struct sctp_chunk *sctp_make_op_error_fixed(
1268 const struct sctp_association *asoc,
1269 const struct sctp_chunk *chunk)
1270{
1271 size_t size = asoc ? asoc->pathmtu : 0;
1272
1273 if (!size)
1274 size = SCTP_DEFAULT_MAXSEGMENT;
1275
1276 return sctp_make_op_error_space(asoc, chunk, size);
1277}
1278
1279/* Create an Operation Error chunk. */
1280struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc,
1281 const struct sctp_chunk *chunk,
1282 __be16 cause_code, const void *payload,
1283 size_t paylen, size_t reserve_tail)
1284{
1285 struct sctp_chunk *retval;
1286
1287 retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail);
1288 if (!retval)
1289 goto nodata;
1290
1291 sctp_init_cause(retval, cause_code, paylen + reserve_tail);
1292 sctp_addto_chunk(retval, paylen, payload);
1293 if (reserve_tail)
1294 sctp_addto_param(retval, reserve_tail, NULL);
1295
1296nodata:
1297 return retval;
1298}
1299
1300struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc,
1301 __u16 key_id)
1302{
1303 struct sctp_authhdr auth_hdr;
1304 struct sctp_hmac *hmac_desc;
1305 struct sctp_chunk *retval;
1306
1307 /* Get the first hmac that the peer told us to use */
1308 hmac_desc = sctp_auth_asoc_get_hmac(asoc);
1309 if (unlikely(!hmac_desc))
1310 return NULL;
1311
1312 retval = sctp_make_control(asoc, SCTP_CID_AUTH, 0,
1313 hmac_desc->hmac_len + sizeof(auth_hdr),
1314 GFP_ATOMIC);
1315 if (!retval)
1316 return NULL;
1317
1318 auth_hdr.hmac_id = htons(hmac_desc->hmac_id);
1319 auth_hdr.shkey_id = htons(key_id);
1320
1321 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(auth_hdr),
1322 &auth_hdr);
1323
1324 skb_put_zero(retval->skb, hmac_desc->hmac_len);
1325
1326 /* Adjust the chunk header to include the empty MAC */
1327 retval->chunk_hdr->length =
1328 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len);
1329 retval->chunk_end = skb_tail_pointer(retval->skb);
1330
1331 return retval;
1332}
1333
1334
1335/********************************************************************
1336 * 2nd Level Abstractions
1337 ********************************************************************/
1338
1339/* Turn an skb into a chunk.
1340 * FIXME: Eventually move the structure directly inside the skb->cb[].
1341 *
1342 * sctpimpguide-05.txt Section 2.8.2
1343 * M1) Each time a new DATA chunk is transmitted
1344 * set the 'TSN.Missing.Report' count for that TSN to 0. The
1345 * 'TSN.Missing.Report' count will be used to determine missing chunks
1346 * and when to fast retransmit.
1347 *
1348 */
1349struct sctp_chunk *sctp_chunkify(struct sk_buff *skb,
1350 const struct sctp_association *asoc,
1351 struct sock *sk, gfp_t gfp)
1352{
1353 struct sctp_chunk *retval;
1354
1355 retval = kmem_cache_zalloc(sctp_chunk_cachep, gfp);
1356
1357 if (!retval)
1358 goto nodata;
1359 if (!sk)
1360 pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb);
1361
1362 INIT_LIST_HEAD(&retval->list);
1363 retval->skb = skb;
1364 retval->asoc = (struct sctp_association *)asoc;
1365 retval->singleton = 1;
1366
1367 retval->fast_retransmit = SCTP_CAN_FRTX;
1368
1369 /* Polish the bead hole. */
1370 INIT_LIST_HEAD(&retval->transmitted_list);
1371 INIT_LIST_HEAD(&retval->frag_list);
1372 SCTP_DBG_OBJCNT_INC(chunk);
1373 refcount_set(&retval->refcnt, 1);
1374
1375nodata:
1376 return retval;
1377}
1378
1379/* Set chunk->source and dest based on the IP header in chunk->skb. */
1380void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src,
1381 union sctp_addr *dest)
1382{
1383 memcpy(&chunk->source, src, sizeof(union sctp_addr));
1384 memcpy(&chunk->dest, dest, sizeof(union sctp_addr));
1385}
1386
1387/* Extract the source address from a chunk. */
1388const union sctp_addr *sctp_source(const struct sctp_chunk *chunk)
1389{
1390 /* If we have a known transport, use that. */
1391 if (chunk->transport) {
1392 return &chunk->transport->ipaddr;
1393 } else {
1394 /* Otherwise, extract it from the IP header. */
1395 return &chunk->source;
1396 }
1397}
1398
1399/* Create a new chunk, setting the type and flags headers from the
1400 * arguments, reserving enough space for a 'paylen' byte payload.
1401 */
1402static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc,
1403 __u8 type, __u8 flags, int paylen,
1404 gfp_t gfp)
1405{
1406 struct sctp_chunkhdr *chunk_hdr;
1407 struct sctp_chunk *retval;
1408 struct sk_buff *skb;
1409 struct sock *sk;
1410 int chunklen;
1411
1412 chunklen = SCTP_PAD4(sizeof(*chunk_hdr) + paylen);
1413 if (chunklen > SCTP_MAX_CHUNK_LEN)
1414 goto nodata;
1415
1416 /* No need to allocate LL here, as this is only a chunk. */
1417 skb = alloc_skb(chunklen, gfp);
1418 if (!skb)
1419 goto nodata;
1420
1421 /* Make room for the chunk header. */
1422 chunk_hdr = (struct sctp_chunkhdr *)skb_put(skb, sizeof(*chunk_hdr));
1423 chunk_hdr->type = type;
1424 chunk_hdr->flags = flags;
1425 chunk_hdr->length = htons(sizeof(*chunk_hdr));
1426
1427 sk = asoc ? asoc->base.sk : NULL;
1428 retval = sctp_chunkify(skb, asoc, sk, gfp);
1429 if (!retval) {
1430 kfree_skb(skb);
1431 goto nodata;
1432 }
1433
1434 retval->chunk_hdr = chunk_hdr;
1435 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(*chunk_hdr);
1436
1437 /* Determine if the chunk needs to be authenticated */
1438 if (sctp_auth_send_cid(type, asoc))
1439 retval->auth = 1;
1440
1441 return retval;
1442nodata:
1443 return NULL;
1444}
1445
1446static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc,
1447 __u8 flags, int paylen, gfp_t gfp)
1448{
1449 return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen, gfp);
1450}
1451
1452struct sctp_chunk *sctp_make_idata(const struct sctp_association *asoc,
1453 __u8 flags, int paylen, gfp_t gfp)
1454{
1455 return _sctp_make_chunk(asoc, SCTP_CID_I_DATA, flags, paylen, gfp);
1456}
1457
1458static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc,
1459 __u8 type, __u8 flags, int paylen,
1460 gfp_t gfp)
1461{
1462 struct sctp_chunk *chunk;
1463
1464 chunk = _sctp_make_chunk(asoc, type, flags, paylen, gfp);
1465 if (chunk)
1466 sctp_control_set_owner_w(chunk);
1467
1468 return chunk;
1469}
1470
1471/* Release the memory occupied by a chunk. */
1472static void sctp_chunk_destroy(struct sctp_chunk *chunk)
1473{
1474 BUG_ON(!list_empty(&chunk->list));
1475 list_del_init(&chunk->transmitted_list);
1476
1477 consume_skb(chunk->skb);
1478 consume_skb(chunk->auth_chunk);
1479
1480 SCTP_DBG_OBJCNT_DEC(chunk);
1481 kmem_cache_free(sctp_chunk_cachep, chunk);
1482}
1483
1484/* Possibly, free the chunk. */
1485void sctp_chunk_free(struct sctp_chunk *chunk)
1486{
1487 /* Release our reference on the message tracker. */
1488 if (chunk->msg)
1489 sctp_datamsg_put(chunk->msg);
1490
1491 sctp_chunk_put(chunk);
1492}
1493
1494/* Grab a reference to the chunk. */
1495void sctp_chunk_hold(struct sctp_chunk *ch)
1496{
1497 refcount_inc(&ch->refcnt);
1498}
1499
1500/* Release a reference to the chunk. */
1501void sctp_chunk_put(struct sctp_chunk *ch)
1502{
1503 if (refcount_dec_and_test(&ch->refcnt))
1504 sctp_chunk_destroy(ch);
1505}
1506
1507/* Append bytes to the end of a chunk. Will panic if chunk is not big
1508 * enough.
1509 */
1510void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data)
1511{
1512 int chunklen = ntohs(chunk->chunk_hdr->length);
1513 int padlen = SCTP_PAD4(chunklen) - chunklen;
1514 void *target;
1515
1516 skb_put_zero(chunk->skb, padlen);
1517 target = skb_put_data(chunk->skb, data, len);
1518
1519 /* Adjust the chunk length field. */
1520 chunk->chunk_hdr->length = htons(chunklen + padlen + len);
1521 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1522
1523 return target;
1524}
1525
1526/* Append bytes to the end of a chunk. Returns NULL if there isn't sufficient
1527 * space in the chunk
1528 */
1529static void *sctp_addto_chunk_fixed(struct sctp_chunk *chunk,
1530 int len, const void *data)
1531{
1532 if (skb_tailroom(chunk->skb) >= len)
1533 return sctp_addto_chunk(chunk, len, data);
1534 else
1535 return NULL;
1536}
1537
1538/* Append bytes from user space to the end of a chunk. Will panic if
1539 * chunk is not big enough.
1540 * Returns a kernel err value.
1541 */
1542int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
1543 struct iov_iter *from)
1544{
1545 void *target;
1546
1547 /* Make room in chunk for data. */
1548 target = skb_put(chunk->skb, len);
1549
1550 /* Copy data (whole iovec) into chunk */
1551 if (!copy_from_iter_full(target, len, from))
1552 return -EFAULT;
1553
1554 /* Adjust the chunk length field. */
1555 chunk->chunk_hdr->length =
1556 htons(ntohs(chunk->chunk_hdr->length) + len);
1557 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1558
1559 return 0;
1560}
1561
1562/* Helper function to assign a TSN if needed. This assumes that both
1563 * the data_hdr and association have already been assigned.
1564 */
1565void sctp_chunk_assign_ssn(struct sctp_chunk *chunk)
1566{
1567 struct sctp_stream *stream;
1568 struct sctp_chunk *lchunk;
1569 struct sctp_datamsg *msg;
1570 __u16 ssn, sid;
1571
1572 if (chunk->has_ssn)
1573 return;
1574
1575 /* All fragments will be on the same stream */
1576 sid = ntohs(chunk->subh.data_hdr->stream);
1577 stream = &chunk->asoc->stream;
1578
1579 /* Now assign the sequence number to the entire message.
1580 * All fragments must have the same stream sequence number.
1581 */
1582 msg = chunk->msg;
1583 list_for_each_entry(lchunk, &msg->chunks, frag_list) {
1584 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
1585 ssn = 0;
1586 } else {
1587 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG)
1588 ssn = sctp_ssn_next(stream, out, sid);
1589 else
1590 ssn = sctp_ssn_peek(stream, out, sid);
1591 }
1592
1593 lchunk->subh.data_hdr->ssn = htons(ssn);
1594 lchunk->has_ssn = 1;
1595 }
1596}
1597
1598/* Helper function to assign a TSN if needed. This assumes that both
1599 * the data_hdr and association have already been assigned.
1600 */
1601void sctp_chunk_assign_tsn(struct sctp_chunk *chunk)
1602{
1603 if (!chunk->has_tsn) {
1604 /* This is the last possible instant to
1605 * assign a TSN.
1606 */
1607 chunk->subh.data_hdr->tsn =
1608 htonl(sctp_association_get_next_tsn(chunk->asoc));
1609 chunk->has_tsn = 1;
1610 }
1611}
1612
1613/* Create a CLOSED association to use with an incoming packet. */
1614struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep,
1615 struct sctp_chunk *chunk,
1616 gfp_t gfp)
1617{
1618 struct sctp_association *asoc;
1619 enum sctp_scope scope;
1620 struct sk_buff *skb;
1621
1622 /* Create the bare association. */
1623 scope = sctp_scope(sctp_source(chunk));
1624 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp);
1625 if (!asoc)
1626 goto nodata;
1627 asoc->temp = 1;
1628 skb = chunk->skb;
1629 /* Create an entry for the source address of the packet. */
1630 SCTP_INPUT_CB(skb)->af->from_skb(&asoc->c.peer_addr, skb, 1);
1631
1632nodata:
1633 return asoc;
1634}
1635
1636/* Build a cookie representing asoc.
1637 * This INCLUDES the param header needed to put the cookie in the INIT ACK.
1638 */
1639static struct sctp_cookie_param *sctp_pack_cookie(
1640 const struct sctp_endpoint *ep,
1641 const struct sctp_association *asoc,
1642 const struct sctp_chunk *init_chunk,
1643 int *cookie_len, const __u8 *raw_addrs,
1644 int addrs_len)
1645{
1646 struct sctp_signed_cookie *cookie;
1647 struct sctp_cookie_param *retval;
1648 int headersize, bodysize;
1649
1650 /* Header size is static data prior to the actual cookie, including
1651 * any padding.
1652 */
1653 headersize = sizeof(struct sctp_paramhdr) +
1654 (sizeof(struct sctp_signed_cookie) -
1655 sizeof(struct sctp_cookie));
1656 bodysize = sizeof(struct sctp_cookie)
1657 + ntohs(init_chunk->chunk_hdr->length) + addrs_len;
1658
1659 /* Pad out the cookie to a multiple to make the signature
1660 * functions simpler to write.
1661 */
1662 if (bodysize % SCTP_COOKIE_MULTIPLE)
1663 bodysize += SCTP_COOKIE_MULTIPLE
1664 - (bodysize % SCTP_COOKIE_MULTIPLE);
1665 *cookie_len = headersize + bodysize;
1666
1667 /* Clear this memory since we are sending this data structure
1668 * out on the network.
1669 */
1670 retval = kzalloc(*cookie_len, GFP_ATOMIC);
1671 if (!retval)
1672 goto nodata;
1673
1674 cookie = (struct sctp_signed_cookie *) retval->body;
1675
1676 /* Set up the parameter header. */
1677 retval->p.type = SCTP_PARAM_STATE_COOKIE;
1678 retval->p.length = htons(*cookie_len);
1679
1680 /* Copy the cookie part of the association itself. */
1681 cookie->c = asoc->c;
1682 /* Save the raw address list length in the cookie. */
1683 cookie->c.raw_addr_list_len = addrs_len;
1684
1685 /* Remember PR-SCTP capability. */
1686 cookie->c.prsctp_capable = asoc->peer.prsctp_capable;
1687
1688 /* Save adaptation indication in the cookie. */
1689 cookie->c.adaptation_ind = asoc->peer.adaptation_ind;
1690
1691 /* Set an expiration time for the cookie. */
1692 cookie->c.expiration = ktime_add(asoc->cookie_life,
1693 ktime_get_real());
1694
1695 /* Copy the peer's init packet. */
1696 memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr,
1697 ntohs(init_chunk->chunk_hdr->length));
1698
1699 /* Copy the raw local address list of the association. */
1700 memcpy((__u8 *)&cookie->c.peer_init[0] +
1701 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len);
1702
1703 if (sctp_sk(ep->base.sk)->hmac) {
1704 SHASH_DESC_ON_STACK(desc, sctp_sk(ep->base.sk)->hmac);
1705 int err;
1706
1707 /* Sign the message. */
1708 desc->tfm = sctp_sk(ep->base.sk)->hmac;
1709 desc->flags = 0;
1710
1711 err = crypto_shash_setkey(desc->tfm, ep->secret_key,
1712 sizeof(ep->secret_key)) ?:
1713 crypto_shash_digest(desc, (u8 *)&cookie->c, bodysize,
1714 cookie->signature);
1715 shash_desc_zero(desc);
1716 if (err)
1717 goto free_cookie;
1718 }
1719
1720 return retval;
1721
1722free_cookie:
1723 kfree(retval);
1724nodata:
1725 *cookie_len = 0;
1726 return NULL;
1727}
1728
1729/* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */
1730struct sctp_association *sctp_unpack_cookie(
1731 const struct sctp_endpoint *ep,
1732 const struct sctp_association *asoc,
1733 struct sctp_chunk *chunk, gfp_t gfp,
1734 int *error, struct sctp_chunk **errp)
1735{
1736 struct sctp_association *retval = NULL;
1737 int headersize, bodysize, fixed_size;
1738 struct sctp_signed_cookie *cookie;
1739 struct sk_buff *skb = chunk->skb;
1740 struct sctp_cookie *bear_cookie;
1741 __u8 *digest = ep->digest;
1742 enum sctp_scope scope;
1743 unsigned int len;
1744 ktime_t kt;
1745
1746 /* Header size is static data prior to the actual cookie, including
1747 * any padding.
1748 */
1749 headersize = sizeof(struct sctp_chunkhdr) +
1750 (sizeof(struct sctp_signed_cookie) -
1751 sizeof(struct sctp_cookie));
1752 bodysize = ntohs(chunk->chunk_hdr->length) - headersize;
1753 fixed_size = headersize + sizeof(struct sctp_cookie);
1754
1755 /* Verify that the chunk looks like it even has a cookie.
1756 * There must be enough room for our cookie and our peer's
1757 * INIT chunk.
1758 */
1759 len = ntohs(chunk->chunk_hdr->length);
1760 if (len < fixed_size + sizeof(struct sctp_chunkhdr))
1761 goto malformed;
1762
1763 /* Verify that the cookie has been padded out. */
1764 if (bodysize % SCTP_COOKIE_MULTIPLE)
1765 goto malformed;
1766
1767 /* Process the cookie. */
1768 cookie = chunk->subh.cookie_hdr;
1769 bear_cookie = &cookie->c;
1770
1771 if (!sctp_sk(ep->base.sk)->hmac)
1772 goto no_hmac;
1773
1774 /* Check the signature. */
1775 {
1776 SHASH_DESC_ON_STACK(desc, sctp_sk(ep->base.sk)->hmac);
1777 int err;
1778
1779 desc->tfm = sctp_sk(ep->base.sk)->hmac;
1780 desc->flags = 0;
1781
1782 err = crypto_shash_setkey(desc->tfm, ep->secret_key,
1783 sizeof(ep->secret_key)) ?:
1784 crypto_shash_digest(desc, (u8 *)bear_cookie, bodysize,
1785 digest);
1786 shash_desc_zero(desc);
1787
1788 if (err) {
1789 *error = -SCTP_IERROR_NOMEM;
1790 goto fail;
1791 }
1792 }
1793
1794 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
1795 *error = -SCTP_IERROR_BAD_SIG;
1796 goto fail;
1797 }
1798
1799no_hmac:
1800 /* IG Section 2.35.2:
1801 * 3) Compare the port numbers and the verification tag contained
1802 * within the COOKIE ECHO chunk to the actual port numbers and the
1803 * verification tag within the SCTP common header of the received
1804 * packet. If these values do not match the packet MUST be silently
1805 * discarded,
1806 */
1807 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) {
1808 *error = -SCTP_IERROR_BAD_TAG;
1809 goto fail;
1810 }
1811
1812 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port ||
1813 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) {
1814 *error = -SCTP_IERROR_BAD_PORTS;
1815 goto fail;
1816 }
1817
1818 /* Check to see if the cookie is stale. If there is already
1819 * an association, there is no need to check cookie's expiration
1820 * for init collision case of lost COOKIE ACK.
1821 * If skb has been timestamped, then use the stamp, otherwise
1822 * use current time. This introduces a small possibility that
1823 * that a cookie may be considered expired, but his would only slow
1824 * down the new association establishment instead of every packet.
1825 */
1826 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP))
1827 kt = skb_get_ktime(skb);
1828 else
1829 kt = ktime_get_real();
1830
1831 if (!asoc && ktime_before(bear_cookie->expiration, kt)) {
1832 /*
1833 * Section 3.3.10.3 Stale Cookie Error (3)
1834 *
1835 * Cause of error
1836 * ---------------
1837 * Stale Cookie Error: Indicates the receipt of a valid State
1838 * Cookie that has expired.
1839 */
1840 len = ntohs(chunk->chunk_hdr->length);
1841 *errp = sctp_make_op_error_space(asoc, chunk, len);
1842 if (*errp) {
1843 suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration));
1844 __be32 n = htonl(usecs);
1845
1846 sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE,
1847 sizeof(n));
1848 sctp_addto_chunk(*errp, sizeof(n), &n);
1849 *error = -SCTP_IERROR_STALE_COOKIE;
1850 } else
1851 *error = -SCTP_IERROR_NOMEM;
1852
1853 goto fail;
1854 }
1855
1856 /* Make a new base association. */
1857 scope = sctp_scope(sctp_source(chunk));
1858 retval = sctp_association_new(ep, ep->base.sk, scope, gfp);
1859 if (!retval) {
1860 *error = -SCTP_IERROR_NOMEM;
1861 goto fail;
1862 }
1863
1864 /* Set up our peer's port number. */
1865 retval->peer.port = ntohs(chunk->sctp_hdr->source);
1866
1867 /* Populate the association from the cookie. */
1868 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie));
1869
1870 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie,
1871 GFP_ATOMIC) < 0) {
1872 *error = -SCTP_IERROR_NOMEM;
1873 goto fail;
1874 }
1875
1876 /* Also, add the destination address. */
1877 if (list_empty(&retval->base.bind_addr.address_list)) {
1878 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest,
1879 sizeof(chunk->dest), SCTP_ADDR_SRC,
1880 GFP_ATOMIC);
1881 }
1882
1883 retval->next_tsn = retval->c.initial_tsn;
1884 retval->ctsn_ack_point = retval->next_tsn - 1;
1885 retval->addip_serial = retval->c.initial_tsn;
1886 retval->strreset_outseq = retval->c.initial_tsn;
1887 retval->adv_peer_ack_point = retval->ctsn_ack_point;
1888 retval->peer.prsctp_capable = retval->c.prsctp_capable;
1889 retval->peer.adaptation_ind = retval->c.adaptation_ind;
1890
1891 /* The INIT stuff will be done by the side effects. */
1892 return retval;
1893
1894fail:
1895 if (retval)
1896 sctp_association_free(retval);
1897
1898 return NULL;
1899
1900malformed:
1901 /* Yikes! The packet is either corrupt or deliberately
1902 * malformed.
1903 */
1904 *error = -SCTP_IERROR_MALFORMED;
1905 goto fail;
1906}
1907
1908/********************************************************************
1909 * 3rd Level Abstractions
1910 ********************************************************************/
1911
1912struct __sctp_missing {
1913 __be32 num_missing;
1914 __be16 type;
1915} __packed;
1916
1917/*
1918 * Report a missing mandatory parameter.
1919 */
1920static int sctp_process_missing_param(const struct sctp_association *asoc,
1921 enum sctp_param paramtype,
1922 struct sctp_chunk *chunk,
1923 struct sctp_chunk **errp)
1924{
1925 struct __sctp_missing report;
1926 __u16 len;
1927
1928 len = SCTP_PAD4(sizeof(report));
1929
1930 /* Make an ERROR chunk, preparing enough room for
1931 * returning multiple unknown parameters.
1932 */
1933 if (!*errp)
1934 *errp = sctp_make_op_error_space(asoc, chunk, len);
1935
1936 if (*errp) {
1937 report.num_missing = htonl(1);
1938 report.type = paramtype;
1939 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM,
1940 sizeof(report));
1941 sctp_addto_chunk(*errp, sizeof(report), &report);
1942 }
1943
1944 /* Stop processing this chunk. */
1945 return 0;
1946}
1947
1948/* Report an Invalid Mandatory Parameter. */
1949static int sctp_process_inv_mandatory(const struct sctp_association *asoc,
1950 struct sctp_chunk *chunk,
1951 struct sctp_chunk **errp)
1952{
1953 /* Invalid Mandatory Parameter Error has no payload. */
1954
1955 if (!*errp)
1956 *errp = sctp_make_op_error_space(asoc, chunk, 0);
1957
1958 if (*errp)
1959 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0);
1960
1961 /* Stop processing this chunk. */
1962 return 0;
1963}
1964
1965static int sctp_process_inv_paramlength(const struct sctp_association *asoc,
1966 struct sctp_paramhdr *param,
1967 const struct sctp_chunk *chunk,
1968 struct sctp_chunk **errp)
1969{
1970 /* This is a fatal error. Any accumulated non-fatal errors are
1971 * not reported.
1972 */
1973 if (*errp)
1974 sctp_chunk_free(*errp);
1975
1976 /* Create an error chunk and fill it in with our payload. */
1977 *errp = sctp_make_violation_paramlen(asoc, chunk, param);
1978
1979 return 0;
1980}
1981
1982
1983/* Do not attempt to handle the HOST_NAME parm. However, do
1984 * send back an indicator to the peer.
1985 */
1986static int sctp_process_hn_param(const struct sctp_association *asoc,
1987 union sctp_params param,
1988 struct sctp_chunk *chunk,
1989 struct sctp_chunk **errp)
1990{
1991 __u16 len = ntohs(param.p->length);
1992
1993 /* Processing of the HOST_NAME parameter will generate an
1994 * ABORT. If we've accumulated any non-fatal errors, they
1995 * would be unrecognized parameters and we should not include
1996 * them in the ABORT.
1997 */
1998 if (*errp)
1999 sctp_chunk_free(*errp);
2000
2001 *errp = sctp_make_op_error_space(asoc, chunk, len);
2002
2003 if (*errp) {
2004 sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, len);
2005 sctp_addto_chunk(*errp, len, param.v);
2006 }
2007
2008 /* Stop processing this chunk. */
2009 return 0;
2010}
2011
2012static int sctp_verify_ext_param(struct net *net, union sctp_params param)
2013{
2014 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
2015 int have_asconf = 0;
2016 int have_auth = 0;
2017 int i;
2018
2019 for (i = 0; i < num_ext; i++) {
2020 switch (param.ext->chunks[i]) {
2021 case SCTP_CID_AUTH:
2022 have_auth = 1;
2023 break;
2024 case SCTP_CID_ASCONF:
2025 case SCTP_CID_ASCONF_ACK:
2026 have_asconf = 1;
2027 break;
2028 }
2029 }
2030
2031 /* ADD-IP Security: The draft requires us to ABORT or ignore the
2032 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this
2033 * only if ADD-IP is turned on and we are not backward-compatible
2034 * mode.
2035 */
2036 if (net->sctp.addip_noauth)
2037 return 1;
2038
2039 if (net->sctp.addip_enable && !have_auth && have_asconf)
2040 return 0;
2041
2042 return 1;
2043}
2044
2045static void sctp_process_ext_param(struct sctp_association *asoc,
2046 union sctp_params param)
2047{
2048 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
2049 struct net *net = sock_net(asoc->base.sk);
2050 int i;
2051
2052 for (i = 0; i < num_ext; i++) {
2053 switch (param.ext->chunks[i]) {
2054 case SCTP_CID_RECONF:
2055 if (asoc->reconf_enable &&
2056 !asoc->peer.reconf_capable)
2057 asoc->peer.reconf_capable = 1;
2058 break;
2059 case SCTP_CID_FWD_TSN:
2060 if (asoc->prsctp_enable && !asoc->peer.prsctp_capable)
2061 asoc->peer.prsctp_capable = 1;
2062 break;
2063 case SCTP_CID_AUTH:
2064 /* if the peer reports AUTH, assume that he
2065 * supports AUTH.
2066 */
2067 if (asoc->ep->auth_enable)
2068 asoc->peer.auth_capable = 1;
2069 break;
2070 case SCTP_CID_ASCONF:
2071 case SCTP_CID_ASCONF_ACK:
2072 if (net->sctp.addip_enable)
2073 asoc->peer.asconf_capable = 1;
2074 break;
2075 case SCTP_CID_I_DATA:
2076 if (sctp_sk(asoc->base.sk)->strm_interleave)
2077 asoc->intl_enable = 1;
2078 break;
2079 default:
2080 break;
2081 }
2082 }
2083}
2084
2085/* RFC 3.2.1 & the Implementers Guide 2.2.
2086 *
2087 * The Parameter Types are encoded such that the
2088 * highest-order two bits specify the action that must be
2089 * taken if the processing endpoint does not recognize the
2090 * Parameter Type.
2091 *
2092 * 00 - Stop processing this parameter; do not process any further
2093 * parameters within this chunk
2094 *
2095 * 01 - Stop processing this parameter, do not process any further
2096 * parameters within this chunk, and report the unrecognized
2097 * parameter in an 'Unrecognized Parameter' ERROR chunk.
2098 *
2099 * 10 - Skip this parameter and continue processing.
2100 *
2101 * 11 - Skip this parameter and continue processing but
2102 * report the unrecognized parameter in an
2103 * 'Unrecognized Parameter' ERROR chunk.
2104 *
2105 * Return value:
2106 * SCTP_IERROR_NO_ERROR - continue with the chunk
2107 * SCTP_IERROR_ERROR - stop and report an error.
2108 * SCTP_IERROR_NOMEME - out of memory.
2109 */
2110static enum sctp_ierror sctp_process_unk_param(
2111 const struct sctp_association *asoc,
2112 union sctp_params param,
2113 struct sctp_chunk *chunk,
2114 struct sctp_chunk **errp)
2115{
2116 int retval = SCTP_IERROR_NO_ERROR;
2117
2118 switch (param.p->type & SCTP_PARAM_ACTION_MASK) {
2119 case SCTP_PARAM_ACTION_DISCARD:
2120 retval = SCTP_IERROR_ERROR;
2121 break;
2122 case SCTP_PARAM_ACTION_SKIP:
2123 break;
2124 case SCTP_PARAM_ACTION_DISCARD_ERR:
2125 retval = SCTP_IERROR_ERROR;
2126 /* Fall through */
2127 case SCTP_PARAM_ACTION_SKIP_ERR:
2128 /* Make an ERROR chunk, preparing enough room for
2129 * returning multiple unknown parameters.
2130 */
2131 if (NULL == *errp)
2132 *errp = sctp_make_op_error_fixed(asoc, chunk);
2133
2134 if (*errp) {
2135 if (!sctp_init_cause_fixed(*errp, SCTP_ERROR_UNKNOWN_PARAM,
2136 SCTP_PAD4(ntohs(param.p->length))))
2137 sctp_addto_chunk_fixed(*errp,
2138 SCTP_PAD4(ntohs(param.p->length)),
2139 param.v);
2140 } else {
2141 /* If there is no memory for generating the ERROR
2142 * report as specified, an ABORT will be triggered
2143 * to the peer and the association won't be
2144 * established.
2145 */
2146 retval = SCTP_IERROR_NOMEM;
2147 }
2148 break;
2149 default:
2150 break;
2151 }
2152
2153 return retval;
2154}
2155
2156/* Verify variable length parameters
2157 * Return values:
2158 * SCTP_IERROR_ABORT - trigger an ABORT
2159 * SCTP_IERROR_NOMEM - out of memory (abort)
2160 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR
2161 * SCTP_IERROR_NO_ERROR - continue with the chunk
2162 */
2163static enum sctp_ierror sctp_verify_param(struct net *net,
2164 const struct sctp_endpoint *ep,
2165 const struct sctp_association *asoc,
2166 union sctp_params param,
2167 enum sctp_cid cid,
2168 struct sctp_chunk *chunk,
2169 struct sctp_chunk **err_chunk)
2170{
2171 struct sctp_hmac_algo_param *hmacs;
2172 int retval = SCTP_IERROR_NO_ERROR;
2173 __u16 n_elt, id = 0;
2174 int i;
2175
2176 /* FIXME - This routine is not looking at each parameter per the
2177 * chunk type, i.e., unrecognized parameters should be further
2178 * identified based on the chunk id.
2179 */
2180
2181 switch (param.p->type) {
2182 case SCTP_PARAM_IPV4_ADDRESS:
2183 case SCTP_PARAM_IPV6_ADDRESS:
2184 case SCTP_PARAM_COOKIE_PRESERVATIVE:
2185 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
2186 case SCTP_PARAM_STATE_COOKIE:
2187 case SCTP_PARAM_HEARTBEAT_INFO:
2188 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
2189 case SCTP_PARAM_ECN_CAPABLE:
2190 case SCTP_PARAM_ADAPTATION_LAYER_IND:
2191 break;
2192
2193 case SCTP_PARAM_SUPPORTED_EXT:
2194 if (!sctp_verify_ext_param(net, param))
2195 return SCTP_IERROR_ABORT;
2196 break;
2197
2198 case SCTP_PARAM_SET_PRIMARY:
2199 if (net->sctp.addip_enable)
2200 break;
2201 goto fallthrough;
2202
2203 case SCTP_PARAM_HOST_NAME_ADDRESS:
2204 /* Tell the peer, we won't support this param. */
2205 sctp_process_hn_param(asoc, param, chunk, err_chunk);
2206 retval = SCTP_IERROR_ABORT;
2207 break;
2208
2209 case SCTP_PARAM_FWD_TSN_SUPPORT:
2210 if (ep->prsctp_enable)
2211 break;
2212 goto fallthrough;
2213
2214 case SCTP_PARAM_RANDOM:
2215 if (!ep->auth_enable)
2216 goto fallthrough;
2217
2218 /* SCTP-AUTH: Secion 6.1
2219 * If the random number is not 32 byte long the association
2220 * MUST be aborted. The ABORT chunk SHOULD contain the error
2221 * cause 'Protocol Violation'.
2222 */
2223 if (SCTP_AUTH_RANDOM_LENGTH !=
2224 ntohs(param.p->length) - sizeof(struct sctp_paramhdr)) {
2225 sctp_process_inv_paramlength(asoc, param.p,
2226 chunk, err_chunk);
2227 retval = SCTP_IERROR_ABORT;
2228 }
2229 break;
2230
2231 case SCTP_PARAM_CHUNKS:
2232 if (!ep->auth_enable)
2233 goto fallthrough;
2234
2235 /* SCTP-AUTH: Section 3.2
2236 * The CHUNKS parameter MUST be included once in the INIT or
2237 * INIT-ACK chunk if the sender wants to receive authenticated
2238 * chunks. Its maximum length is 260 bytes.
2239 */
2240 if (260 < ntohs(param.p->length)) {
2241 sctp_process_inv_paramlength(asoc, param.p,
2242 chunk, err_chunk);
2243 retval = SCTP_IERROR_ABORT;
2244 }
2245 break;
2246
2247 case SCTP_PARAM_HMAC_ALGO:
2248 if (!ep->auth_enable)
2249 goto fallthrough;
2250
2251 hmacs = (struct sctp_hmac_algo_param *)param.p;
2252 n_elt = (ntohs(param.p->length) -
2253 sizeof(struct sctp_paramhdr)) >> 1;
2254
2255 /* SCTP-AUTH: Section 6.1
2256 * The HMAC algorithm based on SHA-1 MUST be supported and
2257 * included in the HMAC-ALGO parameter.
2258 */
2259 for (i = 0; i < n_elt; i++) {
2260 id = ntohs(hmacs->hmac_ids[i]);
2261
2262 if (id == SCTP_AUTH_HMAC_ID_SHA1)
2263 break;
2264 }
2265
2266 if (id != SCTP_AUTH_HMAC_ID_SHA1) {
2267 sctp_process_inv_paramlength(asoc, param.p, chunk,
2268 err_chunk);
2269 retval = SCTP_IERROR_ABORT;
2270 }
2271 break;
2272fallthrough:
2273 default:
2274 pr_debug("%s: unrecognized param:%d for chunk:%d\n",
2275 __func__, ntohs(param.p->type), cid);
2276
2277 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk);
2278 break;
2279 }
2280 return retval;
2281}
2282
2283/* Verify the INIT packet before we process it. */
2284int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
2285 const struct sctp_association *asoc, enum sctp_cid cid,
2286 struct sctp_init_chunk *peer_init,
2287 struct sctp_chunk *chunk, struct sctp_chunk **errp)
2288{
2289 union sctp_params param;
2290 bool has_cookie = false;
2291 int result;
2292
2293 /* Check for missing mandatory parameters. Note: Initial TSN is
2294 * also mandatory, but is not checked here since the valid range
2295 * is 0..2**32-1. RFC4960, section 3.3.3.
2296 */
2297 if (peer_init->init_hdr.num_outbound_streams == 0 ||
2298 peer_init->init_hdr.num_inbound_streams == 0 ||
2299 peer_init->init_hdr.init_tag == 0 ||
2300 ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW)
2301 return sctp_process_inv_mandatory(asoc, chunk, errp);
2302
2303 sctp_walk_params(param, peer_init, init_hdr.params) {
2304 if (param.p->type == SCTP_PARAM_STATE_COOKIE)
2305 has_cookie = true;
2306 }
2307
2308 /* There is a possibility that a parameter length was bad and
2309 * in that case we would have stoped walking the parameters.
2310 * The current param.p would point at the bad one.
2311 * Current consensus on the mailing list is to generate a PROTOCOL
2312 * VIOLATION error. We build the ERROR chunk here and let the normal
2313 * error handling code build and send the packet.
2314 */
2315 if (param.v != (void *)chunk->chunk_end)
2316 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp);
2317
2318 /* The only missing mandatory param possible today is
2319 * the state cookie for an INIT-ACK chunk.
2320 */
2321 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie)
2322 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE,
2323 chunk, errp);
2324
2325 /* Verify all the variable length parameters */
2326 sctp_walk_params(param, peer_init, init_hdr.params) {
2327 result = sctp_verify_param(net, ep, asoc, param, cid,
2328 chunk, errp);
2329 switch (result) {
2330 case SCTP_IERROR_ABORT:
2331 case SCTP_IERROR_NOMEM:
2332 return 0;
2333 case SCTP_IERROR_ERROR:
2334 return 1;
2335 case SCTP_IERROR_NO_ERROR:
2336 default:
2337 break;
2338 }
2339
2340 } /* for (loop through all parameters) */
2341
2342 return 1;
2343}
2344
2345/* Unpack the parameters in an INIT packet into an association.
2346 * Returns 0 on failure, else success.
2347 * FIXME: This is an association method.
2348 */
2349int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk,
2350 const union sctp_addr *peer_addr,
2351 struct sctp_init_chunk *peer_init, gfp_t gfp)
2352{
2353 struct net *net = sock_net(asoc->base.sk);
2354 struct sctp_transport *transport;
2355 struct list_head *pos, *temp;
2356 union sctp_params param;
2357 union sctp_addr addr;
2358 struct sctp_af *af;
2359 int src_match = 0;
2360 char *cookie;
2361
2362 /* We must include the address that the INIT packet came from.
2363 * This is the only address that matters for an INIT packet.
2364 * When processing a COOKIE ECHO, we retrieve the from address
2365 * of the INIT from the cookie.
2366 */
2367
2368 /* This implementation defaults to making the first transport
2369 * added as the primary transport. The source address seems to
2370 * be a a better choice than any of the embedded addresses.
2371 */
2372 if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE))
2373 goto nomem;
2374
2375 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr))
2376 src_match = 1;
2377
2378 /* Process the initialization parameters. */
2379 sctp_walk_params(param, peer_init, init_hdr.params) {
2380 if (!src_match && (param.p->type == SCTP_PARAM_IPV4_ADDRESS ||
2381 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) {
2382 af = sctp_get_af_specific(param_type2af(param.p->type));
2383 af->from_addr_param(&addr, param.addr,
2384 chunk->sctp_hdr->source, 0);
2385 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr))
2386 src_match = 1;
2387 }
2388
2389 if (!sctp_process_param(asoc, param, peer_addr, gfp))
2390 goto clean_up;
2391 }
2392
2393 /* source address of chunk may not match any valid address */
2394 if (!src_match)
2395 goto clean_up;
2396
2397 /* AUTH: After processing the parameters, make sure that we
2398 * have all the required info to potentially do authentications.
2399 */
2400 if (asoc->peer.auth_capable && (!asoc->peer.peer_random ||
2401 !asoc->peer.peer_hmacs))
2402 asoc->peer.auth_capable = 0;
2403
2404 /* In a non-backward compatible mode, if the peer claims
2405 * support for ADD-IP but not AUTH, the ADD-IP spec states
2406 * that we MUST ABORT the association. Section 6. The section
2407 * also give us an option to silently ignore the packet, which
2408 * is what we'll do here.
2409 */
2410 if (!net->sctp.addip_noauth &&
2411 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) {
2412 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP |
2413 SCTP_PARAM_DEL_IP |
2414 SCTP_PARAM_SET_PRIMARY);
2415 asoc->peer.asconf_capable = 0;
2416 goto clean_up;
2417 }
2418
2419 /* Walk list of transports, removing transports in the UNKNOWN state. */
2420 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
2421 transport = list_entry(pos, struct sctp_transport, transports);
2422 if (transport->state == SCTP_UNKNOWN) {
2423 sctp_assoc_rm_peer(asoc, transport);
2424 }
2425 }
2426
2427 /* The fixed INIT headers are always in network byte
2428 * order.
2429 */
2430 asoc->peer.i.init_tag =
2431 ntohl(peer_init->init_hdr.init_tag);
2432 asoc->peer.i.a_rwnd =
2433 ntohl(peer_init->init_hdr.a_rwnd);
2434 asoc->peer.i.num_outbound_streams =
2435 ntohs(peer_init->init_hdr.num_outbound_streams);
2436 asoc->peer.i.num_inbound_streams =
2437 ntohs(peer_init->init_hdr.num_inbound_streams);
2438 asoc->peer.i.initial_tsn =
2439 ntohl(peer_init->init_hdr.initial_tsn);
2440
2441 asoc->strreset_inseq = asoc->peer.i.initial_tsn;
2442
2443 /* Apply the upper bounds for output streams based on peer's
2444 * number of inbound streams.
2445 */
2446 if (asoc->c.sinit_num_ostreams >
2447 ntohs(peer_init->init_hdr.num_inbound_streams)) {
2448 asoc->c.sinit_num_ostreams =
2449 ntohs(peer_init->init_hdr.num_inbound_streams);
2450 }
2451
2452 if (asoc->c.sinit_max_instreams >
2453 ntohs(peer_init->init_hdr.num_outbound_streams)) {
2454 asoc->c.sinit_max_instreams =
2455 ntohs(peer_init->init_hdr.num_outbound_streams);
2456 }
2457
2458 /* Copy Initiation tag from INIT to VT_peer in cookie. */
2459 asoc->c.peer_vtag = asoc->peer.i.init_tag;
2460
2461 /* Peer Rwnd : Current calculated value of the peer's rwnd. */
2462 asoc->peer.rwnd = asoc->peer.i.a_rwnd;
2463
2464 /* Copy cookie in case we need to resend COOKIE-ECHO. */
2465 cookie = asoc->peer.cookie;
2466 if (cookie) {
2467 asoc->peer.cookie = kmemdup(cookie, asoc->peer.cookie_len, gfp);
2468 if (!asoc->peer.cookie)
2469 goto clean_up;
2470 }
2471
2472 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily
2473 * high (for example, implementations MAY use the size of the receiver
2474 * advertised window).
2475 */
2476 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
2477 transports) {
2478 transport->ssthresh = asoc->peer.i.a_rwnd;
2479 }
2480
2481 /* Set up the TSN tracking pieces. */
2482 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
2483 asoc->peer.i.initial_tsn, gfp))
2484 goto clean_up;
2485
2486 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
2487 *
2488 * The stream sequence number in all the streams shall start
2489 * from 0 when the association is established. Also, when the
2490 * stream sequence number reaches the value 65535 the next
2491 * stream sequence number shall be set to 0.
2492 */
2493
2494 if (sctp_stream_init(&asoc->stream, asoc->c.sinit_num_ostreams,
2495 asoc->c.sinit_max_instreams, gfp))
2496 goto clean_up;
2497
2498 if (!asoc->temp && sctp_assoc_set_id(asoc, gfp))
2499 goto clean_up;
2500
2501 /* ADDIP Section 4.1 ASCONF Chunk Procedures
2502 *
2503 * When an endpoint has an ASCONF signaled change to be sent to the
2504 * remote endpoint it should do the following:
2505 * ...
2506 * A2) A serial number should be assigned to the Chunk. The serial
2507 * number should be a monotonically increasing number. All serial
2508 * numbers are defined to be initialized at the start of the
2509 * association to the same value as the Initial TSN.
2510 */
2511 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1;
2512 return 1;
2513
2514clean_up:
2515 /* Release the transport structures. */
2516 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
2517 transport = list_entry(pos, struct sctp_transport, transports);
2518 if (transport->state != SCTP_ACTIVE)
2519 sctp_assoc_rm_peer(asoc, transport);
2520 }
2521
2522nomem:
2523 return 0;
2524}
2525
2526
2527/* Update asoc with the option described in param.
2528 *
2529 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT
2530 *
2531 * asoc is the association to update.
2532 * param is the variable length parameter to use for update.
2533 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO.
2534 * If the current packet is an INIT we want to minimize the amount of
2535 * work we do. In particular, we should not build transport
2536 * structures for the addresses.
2537 */
2538static int sctp_process_param(struct sctp_association *asoc,
2539 union sctp_params param,
2540 const union sctp_addr *peer_addr,
2541 gfp_t gfp)
2542{
2543 struct net *net = sock_net(asoc->base.sk);
2544 struct sctp_endpoint *ep = asoc->ep;
2545 union sctp_addr_param *addr_param;
2546 struct sctp_transport *t;
2547 enum sctp_scope scope;
2548 union sctp_addr addr;
2549 struct sctp_af *af;
2550 int retval = 1, i;
2551 u32 stale;
2552 __u16 sat;
2553
2554 /* We maintain all INIT parameters in network byte order all the
2555 * time. This allows us to not worry about whether the parameters
2556 * came from a fresh INIT, and INIT ACK, or were stored in a cookie.
2557 */
2558 switch (param.p->type) {
2559 case SCTP_PARAM_IPV6_ADDRESS:
2560 if (PF_INET6 != asoc->base.sk->sk_family)
2561 break;
2562 goto do_addr_param;
2563
2564 case SCTP_PARAM_IPV4_ADDRESS:
2565 /* v4 addresses are not allowed on v6-only socket */
2566 if (ipv6_only_sock(asoc->base.sk))
2567 break;
2568do_addr_param:
2569 af = sctp_get_af_specific(param_type2af(param.p->type));
2570 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0);
2571 scope = sctp_scope(peer_addr);
2572 if (sctp_in_scope(net, &addr, scope))
2573 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED))
2574 return 0;
2575 break;
2576
2577 case SCTP_PARAM_COOKIE_PRESERVATIVE:
2578 if (!net->sctp.cookie_preserve_enable)
2579 break;
2580
2581 stale = ntohl(param.life->lifespan_increment);
2582
2583 /* Suggested Cookie Life span increment's unit is msec,
2584 * (1/1000sec).
2585 */
2586 asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale);
2587 break;
2588
2589 case SCTP_PARAM_HOST_NAME_ADDRESS:
2590 pr_debug("%s: unimplemented SCTP_HOST_NAME_ADDRESS\n", __func__);
2591 break;
2592
2593 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
2594 /* Turn off the default values first so we'll know which
2595 * ones are really set by the peer.
2596 */
2597 asoc->peer.ipv4_address = 0;
2598 asoc->peer.ipv6_address = 0;
2599
2600 /* Assume that peer supports the address family
2601 * by which it sends a packet.
2602 */
2603 if (peer_addr->sa.sa_family == AF_INET6)
2604 asoc->peer.ipv6_address = 1;
2605 else if (peer_addr->sa.sa_family == AF_INET)
2606 asoc->peer.ipv4_address = 1;
2607
2608 /* Cycle through address types; avoid divide by 0. */
2609 sat = ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
2610 if (sat)
2611 sat /= sizeof(__u16);
2612
2613 for (i = 0; i < sat; ++i) {
2614 switch (param.sat->types[i]) {
2615 case SCTP_PARAM_IPV4_ADDRESS:
2616 asoc->peer.ipv4_address = 1;
2617 break;
2618
2619 case SCTP_PARAM_IPV6_ADDRESS:
2620 if (PF_INET6 == asoc->base.sk->sk_family)
2621 asoc->peer.ipv6_address = 1;
2622 break;
2623
2624 case SCTP_PARAM_HOST_NAME_ADDRESS:
2625 asoc->peer.hostname_address = 1;
2626 break;
2627
2628 default: /* Just ignore anything else. */
2629 break;
2630 }
2631 }
2632 break;
2633
2634 case SCTP_PARAM_STATE_COOKIE:
2635 asoc->peer.cookie_len =
2636 ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
2637 asoc->peer.cookie = param.cookie->body;
2638 break;
2639
2640 case SCTP_PARAM_HEARTBEAT_INFO:
2641 /* Would be odd to receive, but it causes no problems. */
2642 break;
2643
2644 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
2645 /* Rejected during verify stage. */
2646 break;
2647
2648 case SCTP_PARAM_ECN_CAPABLE:
2649 asoc->peer.ecn_capable = 1;
2650 break;
2651
2652 case SCTP_PARAM_ADAPTATION_LAYER_IND:
2653 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind);
2654 break;
2655
2656 case SCTP_PARAM_SET_PRIMARY:
2657 if (!net->sctp.addip_enable)
2658 goto fall_through;
2659
2660 addr_param = param.v + sizeof(struct sctp_addip_param);
2661
2662 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
2663 if (af == NULL)
2664 break;
2665
2666 af->from_addr_param(&addr, addr_param,
2667 htons(asoc->peer.port), 0);
2668
2669 /* if the address is invalid, we can't process it.
2670 * XXX: see spec for what to do.
2671 */
2672 if (!af->addr_valid(&addr, NULL, NULL))
2673 break;
2674
2675 t = sctp_assoc_lookup_paddr(asoc, &addr);
2676 if (!t)
2677 break;
2678
2679 sctp_assoc_set_primary(asoc, t);
2680 break;
2681
2682 case SCTP_PARAM_SUPPORTED_EXT:
2683 sctp_process_ext_param(asoc, param);
2684 break;
2685
2686 case SCTP_PARAM_FWD_TSN_SUPPORT:
2687 if (asoc->prsctp_enable) {
2688 asoc->peer.prsctp_capable = 1;
2689 break;
2690 }
2691 /* Fall Through */
2692 goto fall_through;
2693
2694 case SCTP_PARAM_RANDOM:
2695 if (!ep->auth_enable)
2696 goto fall_through;
2697
2698 /* Save peer's random parameter */
2699 asoc->peer.peer_random = kmemdup(param.p,
2700 ntohs(param.p->length), gfp);
2701 if (!asoc->peer.peer_random) {
2702 retval = 0;
2703 break;
2704 }
2705 break;
2706
2707 case SCTP_PARAM_HMAC_ALGO:
2708 if (!ep->auth_enable)
2709 goto fall_through;
2710
2711 /* Save peer's HMAC list */
2712 asoc->peer.peer_hmacs = kmemdup(param.p,
2713 ntohs(param.p->length), gfp);
2714 if (!asoc->peer.peer_hmacs) {
2715 retval = 0;
2716 break;
2717 }
2718
2719 /* Set the default HMAC the peer requested*/
2720 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo);
2721 break;
2722
2723 case SCTP_PARAM_CHUNKS:
2724 if (!ep->auth_enable)
2725 goto fall_through;
2726
2727 asoc->peer.peer_chunks = kmemdup(param.p,
2728 ntohs(param.p->length), gfp);
2729 if (!asoc->peer.peer_chunks)
2730 retval = 0;
2731 break;
2732fall_through:
2733 default:
2734 /* Any unrecognized parameters should have been caught
2735 * and handled by sctp_verify_param() which should be
2736 * called prior to this routine. Simply log the error
2737 * here.
2738 */
2739 pr_debug("%s: ignoring param:%d for association:%p.\n",
2740 __func__, ntohs(param.p->type), asoc);
2741 break;
2742 }
2743
2744 return retval;
2745}
2746
2747/* Select a new verification tag. */
2748__u32 sctp_generate_tag(const struct sctp_endpoint *ep)
2749{
2750 /* I believe that this random number generator complies with RFC1750.
2751 * A tag of 0 is reserved for special cases (e.g. INIT).
2752 */
2753 __u32 x;
2754
2755 do {
2756 get_random_bytes(&x, sizeof(__u32));
2757 } while (x == 0);
2758
2759 return x;
2760}
2761
2762/* Select an initial TSN to send during startup. */
2763__u32 sctp_generate_tsn(const struct sctp_endpoint *ep)
2764{
2765 __u32 retval;
2766
2767 get_random_bytes(&retval, sizeof(__u32));
2768 return retval;
2769}
2770
2771/*
2772 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF)
2773 * 0 1 2 3
2774 * 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
2775 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2776 * | Type = 0xC1 | Chunk Flags | Chunk Length |
2777 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2778 * | Serial Number |
2779 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2780 * | Address Parameter |
2781 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2782 * | ASCONF Parameter #1 |
2783 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2784 * \ \
2785 * / .... /
2786 * \ \
2787 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2788 * | ASCONF Parameter #N |
2789 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2790 *
2791 * Address Parameter and other parameter will not be wrapped in this function
2792 */
2793static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc,
2794 union sctp_addr *addr,
2795 int vparam_len)
2796{
2797 struct sctp_addiphdr asconf;
2798 struct sctp_chunk *retval;
2799 int length = sizeof(asconf) + vparam_len;
2800 union sctp_addr_param addrparam;
2801 int addrlen;
2802 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
2803
2804 addrlen = af->to_addr_param(addr, &addrparam);
2805 if (!addrlen)
2806 return NULL;
2807 length += addrlen;
2808
2809 /* Create the chunk. */
2810 retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length,
2811 GFP_ATOMIC);
2812 if (!retval)
2813 return NULL;
2814
2815 asconf.serial = htonl(asoc->addip_serial++);
2816
2817 retval->subh.addip_hdr =
2818 sctp_addto_chunk(retval, sizeof(asconf), &asconf);
2819 retval->param_hdr.v =
2820 sctp_addto_chunk(retval, addrlen, &addrparam);
2821
2822 return retval;
2823}
2824
2825/* ADDIP
2826 * 3.2.1 Add IP Address
2827 * 0 1 2 3
2828 * 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
2829 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2830 * | Type = 0xC001 | Length = Variable |
2831 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2832 * | ASCONF-Request Correlation ID |
2833 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2834 * | Address Parameter |
2835 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2836 *
2837 * 3.2.2 Delete IP Address
2838 * 0 1 2 3
2839 * 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
2840 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2841 * | Type = 0xC002 | Length = Variable |
2842 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2843 * | ASCONF-Request Correlation ID |
2844 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2845 * | Address Parameter |
2846 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2847 *
2848 */
2849struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc,
2850 union sctp_addr *laddr,
2851 struct sockaddr *addrs,
2852 int addrcnt, __be16 flags)
2853{
2854 union sctp_addr_param addr_param;
2855 struct sctp_addip_param param;
2856 int paramlen = sizeof(param);
2857 struct sctp_chunk *retval;
2858 int addr_param_len = 0;
2859 union sctp_addr *addr;
2860 int totallen = 0, i;
2861 int del_pickup = 0;
2862 struct sctp_af *af;
2863 void *addr_buf;
2864
2865 /* Get total length of all the address parameters. */
2866 addr_buf = addrs;
2867 for (i = 0; i < addrcnt; i++) {
2868 addr = addr_buf;
2869 af = sctp_get_af_specific(addr->v4.sin_family);
2870 addr_param_len = af->to_addr_param(addr, &addr_param);
2871
2872 totallen += paramlen;
2873 totallen += addr_param_len;
2874
2875 addr_buf += af->sockaddr_len;
2876 if (asoc->asconf_addr_del_pending && !del_pickup) {
2877 /* reuse the parameter length from the same scope one */
2878 totallen += paramlen;
2879 totallen += addr_param_len;
2880 del_pickup = 1;
2881
2882 pr_debug("%s: picked same-scope del_pending addr, "
2883 "totallen for all addresses is %d\n",
2884 __func__, totallen);
2885 }
2886 }
2887
2888 /* Create an asconf chunk with the required length. */
2889 retval = sctp_make_asconf(asoc, laddr, totallen);
2890 if (!retval)
2891 return NULL;
2892
2893 /* Add the address parameters to the asconf chunk. */
2894 addr_buf = addrs;
2895 for (i = 0; i < addrcnt; i++) {
2896 addr = addr_buf;
2897 af = sctp_get_af_specific(addr->v4.sin_family);
2898 addr_param_len = af->to_addr_param(addr, &addr_param);
2899 param.param_hdr.type = flags;
2900 param.param_hdr.length = htons(paramlen + addr_param_len);
2901 param.crr_id = htonl(i);
2902
2903 sctp_addto_chunk(retval, paramlen, ¶m);
2904 sctp_addto_chunk(retval, addr_param_len, &addr_param);
2905
2906 addr_buf += af->sockaddr_len;
2907 }
2908 if (flags == SCTP_PARAM_ADD_IP && del_pickup) {
2909 addr = asoc->asconf_addr_del_pending;
2910 af = sctp_get_af_specific(addr->v4.sin_family);
2911 addr_param_len = af->to_addr_param(addr, &addr_param);
2912 param.param_hdr.type = SCTP_PARAM_DEL_IP;
2913 param.param_hdr.length = htons(paramlen + addr_param_len);
2914 param.crr_id = htonl(i);
2915
2916 sctp_addto_chunk(retval, paramlen, ¶m);
2917 sctp_addto_chunk(retval, addr_param_len, &addr_param);
2918 }
2919 return retval;
2920}
2921
2922/* ADDIP
2923 * 3.2.4 Set Primary IP Address
2924 * 0 1 2 3
2925 * 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
2926 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2927 * | Type =0xC004 | Length = Variable |
2928 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2929 * | ASCONF-Request Correlation ID |
2930 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2931 * | Address Parameter |
2932 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2933 *
2934 * Create an ASCONF chunk with Set Primary IP address parameter.
2935 */
2936struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
2937 union sctp_addr *addr)
2938{
2939 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
2940 union sctp_addr_param addrparam;
2941 struct sctp_addip_param param;
2942 struct sctp_chunk *retval;
2943 int len = sizeof(param);
2944 int addrlen;
2945
2946 addrlen = af->to_addr_param(addr, &addrparam);
2947 if (!addrlen)
2948 return NULL;
2949 len += addrlen;
2950
2951 /* Create the chunk and make asconf header. */
2952 retval = sctp_make_asconf(asoc, addr, len);
2953 if (!retval)
2954 return NULL;
2955
2956 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY;
2957 param.param_hdr.length = htons(len);
2958 param.crr_id = 0;
2959
2960 sctp_addto_chunk(retval, sizeof(param), ¶m);
2961 sctp_addto_chunk(retval, addrlen, &addrparam);
2962
2963 return retval;
2964}
2965
2966/* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK)
2967 * 0 1 2 3
2968 * 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
2969 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2970 * | Type = 0x80 | Chunk Flags | Chunk Length |
2971 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2972 * | Serial Number |
2973 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2974 * | ASCONF Parameter Response#1 |
2975 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2976 * \ \
2977 * / .... /
2978 * \ \
2979 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2980 * | ASCONF Parameter Response#N |
2981 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2982 *
2983 * Create an ASCONF_ACK chunk with enough space for the parameter responses.
2984 */
2985static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc,
2986 __u32 serial, int vparam_len)
2987{
2988 struct sctp_addiphdr asconf;
2989 struct sctp_chunk *retval;
2990 int length = sizeof(asconf) + vparam_len;
2991
2992 /* Create the chunk. */
2993 retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length,
2994 GFP_ATOMIC);
2995 if (!retval)
2996 return NULL;
2997
2998 asconf.serial = htonl(serial);
2999
3000 retval->subh.addip_hdr =
3001 sctp_addto_chunk(retval, sizeof(asconf), &asconf);
3002
3003 return retval;
3004}
3005
3006/* Add response parameters to an ASCONF_ACK chunk. */
3007static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id,
3008 __be16 err_code,
3009 struct sctp_addip_param *asconf_param)
3010{
3011 struct sctp_addip_param ack_param;
3012 struct sctp_errhdr err_param;
3013 int asconf_param_len = 0;
3014 int err_param_len = 0;
3015 __be16 response_type;
3016
3017 if (SCTP_ERROR_NO_ERROR == err_code) {
3018 response_type = SCTP_PARAM_SUCCESS_REPORT;
3019 } else {
3020 response_type = SCTP_PARAM_ERR_CAUSE;
3021 err_param_len = sizeof(err_param);
3022 if (asconf_param)
3023 asconf_param_len =
3024 ntohs(asconf_param->param_hdr.length);
3025 }
3026
3027 /* Add Success Indication or Error Cause Indication parameter. */
3028 ack_param.param_hdr.type = response_type;
3029 ack_param.param_hdr.length = htons(sizeof(ack_param) +
3030 err_param_len +
3031 asconf_param_len);
3032 ack_param.crr_id = crr_id;
3033 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param);
3034
3035 if (SCTP_ERROR_NO_ERROR == err_code)
3036 return;
3037
3038 /* Add Error Cause parameter. */
3039 err_param.cause = err_code;
3040 err_param.length = htons(err_param_len + asconf_param_len);
3041 sctp_addto_chunk(chunk, err_param_len, &err_param);
3042
3043 /* Add the failed TLV copied from ASCONF chunk. */
3044 if (asconf_param)
3045 sctp_addto_chunk(chunk, asconf_param_len, asconf_param);
3046}
3047
3048/* Process a asconf parameter. */
3049static __be16 sctp_process_asconf_param(struct sctp_association *asoc,
3050 struct sctp_chunk *asconf,
3051 struct sctp_addip_param *asconf_param)
3052{
3053 union sctp_addr_param *addr_param;
3054 struct sctp_transport *peer;
3055 union sctp_addr addr;
3056 struct sctp_af *af;
3057
3058 addr_param = (void *)asconf_param + sizeof(*asconf_param);
3059
3060 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP &&
3061 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP &&
3062 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY)
3063 return SCTP_ERROR_UNKNOWN_PARAM;
3064
3065 switch (addr_param->p.type) {
3066 case SCTP_PARAM_IPV6_ADDRESS:
3067 if (!asoc->peer.ipv6_address)
3068 return SCTP_ERROR_DNS_FAILED;
3069 break;
3070 case SCTP_PARAM_IPV4_ADDRESS:
3071 if (!asoc->peer.ipv4_address)
3072 return SCTP_ERROR_DNS_FAILED;
3073 break;
3074 default:
3075 return SCTP_ERROR_DNS_FAILED;
3076 }
3077
3078 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
3079 if (unlikely(!af))
3080 return SCTP_ERROR_DNS_FAILED;
3081
3082 af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0);
3083
3084 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast
3085 * or multicast address.
3086 * (note: wildcard is permitted and requires special handling so
3087 * make sure we check for that)
3088 */
3089 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb))
3090 return SCTP_ERROR_DNS_FAILED;
3091
3092 switch (asconf_param->param_hdr.type) {
3093 case SCTP_PARAM_ADD_IP:
3094 /* Section 4.2.1:
3095 * If the address 0.0.0.0 or ::0 is provided, the source
3096 * address of the packet MUST be added.
3097 */
3098 if (af->is_any(&addr))
3099 memcpy(&addr, &asconf->source, sizeof(addr));
3100
3101 if (security_sctp_bind_connect(asoc->ep->base.sk,
3102 SCTP_PARAM_ADD_IP,
3103 (struct sockaddr *)&addr,
3104 af->sockaddr_len))
3105 return SCTP_ERROR_REQ_REFUSED;
3106
3107 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address
3108 * request and does not have the local resources to add this
3109 * new address to the association, it MUST return an Error
3110 * Cause TLV set to the new error code 'Operation Refused
3111 * Due to Resource Shortage'.
3112 */
3113
3114 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED);
3115 if (!peer)
3116 return SCTP_ERROR_RSRC_LOW;
3117
3118 /* Start the heartbeat timer. */
3119 sctp_transport_reset_hb_timer(peer);
3120 asoc->new_transport = peer;
3121 break;
3122 case SCTP_PARAM_DEL_IP:
3123 /* ADDIP 4.3 D7) If a request is received to delete the
3124 * last remaining IP address of a peer endpoint, the receiver
3125 * MUST send an Error Cause TLV with the error cause set to the
3126 * new error code 'Request to Delete Last Remaining IP Address'.
3127 */
3128 if (asoc->peer.transport_count == 1)
3129 return SCTP_ERROR_DEL_LAST_IP;
3130
3131 /* ADDIP 4.3 D8) If a request is received to delete an IP
3132 * address which is also the source address of the IP packet
3133 * which contained the ASCONF chunk, the receiver MUST reject
3134 * this request. To reject the request the receiver MUST send
3135 * an Error Cause TLV set to the new error code 'Request to
3136 * Delete Source IP Address'
3137 */
3138 if (sctp_cmp_addr_exact(&asconf->source, &addr))
3139 return SCTP_ERROR_DEL_SRC_IP;
3140
3141 /* Section 4.2.2
3142 * If the address 0.0.0.0 or ::0 is provided, all
3143 * addresses of the peer except the source address of the
3144 * packet MUST be deleted.
3145 */
3146 if (af->is_any(&addr)) {
3147 sctp_assoc_set_primary(asoc, asconf->transport);
3148 sctp_assoc_del_nonprimary_peers(asoc,
3149 asconf->transport);
3150 return SCTP_ERROR_NO_ERROR;
3151 }
3152
3153 /* If the address is not part of the association, the
3154 * ASCONF-ACK with Error Cause Indication Parameter
3155 * which including cause of Unresolvable Address should
3156 * be sent.
3157 */
3158 peer = sctp_assoc_lookup_paddr(asoc, &addr);
3159 if (!peer)
3160 return SCTP_ERROR_DNS_FAILED;
3161
3162 sctp_assoc_rm_peer(asoc, peer);
3163 break;
3164 case SCTP_PARAM_SET_PRIMARY:
3165 /* ADDIP Section 4.2.4
3166 * If the address 0.0.0.0 or ::0 is provided, the receiver
3167 * MAY mark the source address of the packet as its
3168 * primary.
3169 */
3170 if (af->is_any(&addr))
3171 memcpy(&addr.v4, sctp_source(asconf), sizeof(addr));
3172
3173 if (security_sctp_bind_connect(asoc->ep->base.sk,
3174 SCTP_PARAM_SET_PRIMARY,
3175 (struct sockaddr *)&addr,
3176 af->sockaddr_len))
3177 return SCTP_ERROR_REQ_REFUSED;
3178
3179 peer = sctp_assoc_lookup_paddr(asoc, &addr);
3180 if (!peer)
3181 return SCTP_ERROR_DNS_FAILED;
3182
3183 sctp_assoc_set_primary(asoc, peer);
3184 break;
3185 }
3186
3187 return SCTP_ERROR_NO_ERROR;
3188}
3189
3190/* Verify the ASCONF packet before we process it. */
3191bool sctp_verify_asconf(const struct sctp_association *asoc,
3192 struct sctp_chunk *chunk, bool addr_param_needed,
3193 struct sctp_paramhdr **errp)
3194{
3195 struct sctp_addip_chunk *addip;
3196 bool addr_param_seen = false;
3197 union sctp_params param;
3198
3199 addip = (struct sctp_addip_chunk *)chunk->chunk_hdr;
3200 sctp_walk_params(param, addip, addip_hdr.params) {
3201 size_t length = ntohs(param.p->length);
3202
3203 *errp = param.p;
3204 switch (param.p->type) {
3205 case SCTP_PARAM_ERR_CAUSE:
3206 break;
3207 case SCTP_PARAM_IPV4_ADDRESS:
3208 if (length != sizeof(struct sctp_ipv4addr_param))
3209 return false;
3210 /* ensure there is only one addr param and it's in the
3211 * beginning of addip_hdr params, or we reject it.
3212 */
3213 if (param.v != addip->addip_hdr.params)
3214 return false;
3215 addr_param_seen = true;
3216 break;
3217 case SCTP_PARAM_IPV6_ADDRESS:
3218 if (length != sizeof(struct sctp_ipv6addr_param))
3219 return false;
3220 if (param.v != addip->addip_hdr.params)
3221 return false;
3222 addr_param_seen = true;
3223 break;
3224 case SCTP_PARAM_ADD_IP:
3225 case SCTP_PARAM_DEL_IP:
3226 case SCTP_PARAM_SET_PRIMARY:
3227 /* In ASCONF chunks, these need to be first. */
3228 if (addr_param_needed && !addr_param_seen)
3229 return false;
3230 length = ntohs(param.addip->param_hdr.length);
3231 if (length < sizeof(struct sctp_addip_param) +
3232 sizeof(**errp))
3233 return false;
3234 break;
3235 case SCTP_PARAM_SUCCESS_REPORT:
3236 case SCTP_PARAM_ADAPTATION_LAYER_IND:
3237 if (length != sizeof(struct sctp_addip_param))
3238 return false;
3239 break;
3240 default:
3241 /* This is unkown to us, reject! */
3242 return false;
3243 }
3244 }
3245
3246 /* Remaining sanity checks. */
3247 if (addr_param_needed && !addr_param_seen)
3248 return false;
3249 if (!addr_param_needed && addr_param_seen)
3250 return false;
3251 if (param.v != chunk->chunk_end)
3252 return false;
3253
3254 return true;
3255}
3256
3257/* Process an incoming ASCONF chunk with the next expected serial no. and
3258 * return an ASCONF_ACK chunk to be sent in response.
3259 */
3260struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
3261 struct sctp_chunk *asconf)
3262{
3263 union sctp_addr_param *addr_param;
3264 struct sctp_addip_chunk *addip;
3265 struct sctp_chunk *asconf_ack;
3266 bool all_param_pass = true;
3267 struct sctp_addiphdr *hdr;
3268 int length = 0, chunk_len;
3269 union sctp_params param;
3270 __be16 err_code;
3271 __u32 serial;
3272
3273 addip = (struct sctp_addip_chunk *)asconf->chunk_hdr;
3274 chunk_len = ntohs(asconf->chunk_hdr->length) -
3275 sizeof(struct sctp_chunkhdr);
3276 hdr = (struct sctp_addiphdr *)asconf->skb->data;
3277 serial = ntohl(hdr->serial);
3278
3279 /* Skip the addiphdr and store a pointer to address parameter. */
3280 length = sizeof(*hdr);
3281 addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
3282 chunk_len -= length;
3283
3284 /* Skip the address parameter and store a pointer to the first
3285 * asconf parameter.
3286 */
3287 length = ntohs(addr_param->p.length);
3288 chunk_len -= length;
3289
3290 /* create an ASCONF_ACK chunk.
3291 * Based on the definitions of parameters, we know that the size of
3292 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF
3293 * parameters.
3294 */
3295 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4);
3296 if (!asconf_ack)
3297 goto done;
3298
3299 /* Process the TLVs contained within the ASCONF chunk. */
3300 sctp_walk_params(param, addip, addip_hdr.params) {
3301 /* Skip preceeding address parameters. */
3302 if (param.p->type == SCTP_PARAM_IPV4_ADDRESS ||
3303 param.p->type == SCTP_PARAM_IPV6_ADDRESS)
3304 continue;
3305
3306 err_code = sctp_process_asconf_param(asoc, asconf,
3307 param.addip);
3308 /* ADDIP 4.1 A7)
3309 * If an error response is received for a TLV parameter,
3310 * all TLVs with no response before the failed TLV are
3311 * considered successful if not reported. All TLVs after
3312 * the failed response are considered unsuccessful unless
3313 * a specific success indication is present for the parameter.
3314 */
3315 if (err_code != SCTP_ERROR_NO_ERROR)
3316 all_param_pass = false;
3317 if (!all_param_pass)
3318 sctp_add_asconf_response(asconf_ack, param.addip->crr_id,
3319 err_code, param.addip);
3320
3321 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add
3322 * an IP address sends an 'Out of Resource' in its response, it
3323 * MUST also fail any subsequent add or delete requests bundled
3324 * in the ASCONF.
3325 */
3326 if (err_code == SCTP_ERROR_RSRC_LOW)
3327 goto done;
3328 }
3329done:
3330 asoc->peer.addip_serial++;
3331
3332 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc
3333 * after freeing the reference to old asconf ack if any.
3334 */
3335 if (asconf_ack) {
3336 sctp_chunk_hold(asconf_ack);
3337 list_add_tail(&asconf_ack->transmitted_list,
3338 &asoc->asconf_ack_list);
3339 }
3340
3341 return asconf_ack;
3342}
3343
3344/* Process a asconf parameter that is successfully acked. */
3345static void sctp_asconf_param_success(struct sctp_association *asoc,
3346 struct sctp_addip_param *asconf_param)
3347{
3348 struct sctp_bind_addr *bp = &asoc->base.bind_addr;
3349 union sctp_addr_param *addr_param;
3350 struct sctp_sockaddr_entry *saddr;
3351 struct sctp_transport *transport;
3352 union sctp_addr addr;
3353 struct sctp_af *af;
3354
3355 addr_param = (void *)asconf_param + sizeof(*asconf_param);
3356
3357 /* We have checked the packet before, so we do not check again. */
3358 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
3359 af->from_addr_param(&addr, addr_param, htons(bp->port), 0);
3360
3361 switch (asconf_param->param_hdr.type) {
3362 case SCTP_PARAM_ADD_IP:
3363 /* This is always done in BH context with a socket lock
3364 * held, so the list can not change.
3365 */
3366 local_bh_disable();
3367 list_for_each_entry(saddr, &bp->address_list, list) {
3368 if (sctp_cmp_addr_exact(&saddr->a, &addr))
3369 saddr->state = SCTP_ADDR_SRC;
3370 }
3371 local_bh_enable();
3372 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
3373 transports) {
3374 sctp_transport_dst_release(transport);
3375 }
3376 break;
3377 case SCTP_PARAM_DEL_IP:
3378 local_bh_disable();
3379 sctp_del_bind_addr(bp, &addr);
3380 if (asoc->asconf_addr_del_pending != NULL &&
3381 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) {
3382 kfree(asoc->asconf_addr_del_pending);
3383 asoc->asconf_addr_del_pending = NULL;
3384 }
3385 local_bh_enable();
3386 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
3387 transports) {
3388 sctp_transport_dst_release(transport);
3389 }
3390 break;
3391 default:
3392 break;
3393 }
3394}
3395
3396/* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk
3397 * for the given asconf parameter. If there is no response for this parameter,
3398 * return the error code based on the third argument 'no_err'.
3399 * ADDIP 4.1
3400 * A7) If an error response is received for a TLV parameter, all TLVs with no
3401 * response before the failed TLV are considered successful if not reported.
3402 * All TLVs after the failed response are considered unsuccessful unless a
3403 * specific success indication is present for the parameter.
3404 */
3405static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack,
3406 struct sctp_addip_param *asconf_param,
3407 int no_err)
3408{
3409 struct sctp_addip_param *asconf_ack_param;
3410 struct sctp_errhdr *err_param;
3411 int asconf_ack_len;
3412 __be16 err_code;
3413 int length;
3414
3415 if (no_err)
3416 err_code = SCTP_ERROR_NO_ERROR;
3417 else
3418 err_code = SCTP_ERROR_REQ_REFUSED;
3419
3420 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) -
3421 sizeof(struct sctp_chunkhdr);
3422
3423 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to
3424 * the first asconf_ack parameter.
3425 */
3426 length = sizeof(struct sctp_addiphdr);
3427 asconf_ack_param = (struct sctp_addip_param *)(asconf_ack->skb->data +
3428 length);
3429 asconf_ack_len -= length;
3430
3431 while (asconf_ack_len > 0) {
3432 if (asconf_ack_param->crr_id == asconf_param->crr_id) {
3433 switch (asconf_ack_param->param_hdr.type) {
3434 case SCTP_PARAM_SUCCESS_REPORT:
3435 return SCTP_ERROR_NO_ERROR;
3436 case SCTP_PARAM_ERR_CAUSE:
3437 length = sizeof(*asconf_ack_param);
3438 err_param = (void *)asconf_ack_param + length;
3439 asconf_ack_len -= length;
3440 if (asconf_ack_len > 0)
3441 return err_param->cause;
3442 else
3443 return SCTP_ERROR_INV_PARAM;
3444 break;
3445 default:
3446 return SCTP_ERROR_INV_PARAM;
3447 }
3448 }
3449
3450 length = ntohs(asconf_ack_param->param_hdr.length);
3451 asconf_ack_param = (void *)asconf_ack_param + length;
3452 asconf_ack_len -= length;
3453 }
3454
3455 return err_code;
3456}
3457
3458/* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */
3459int sctp_process_asconf_ack(struct sctp_association *asoc,
3460 struct sctp_chunk *asconf_ack)
3461{
3462 struct sctp_chunk *asconf = asoc->addip_last_asconf;
3463 struct sctp_addip_param *asconf_param;
3464 __be16 err_code = SCTP_ERROR_NO_ERROR;
3465 union sctp_addr_param *addr_param;
3466 int asconf_len = asconf->skb->len;
3467 int all_param_pass = 0;
3468 int length = 0;
3469 int no_err = 1;
3470 int retval = 0;
3471
3472 /* Skip the chunkhdr and addiphdr from the last asconf sent and store
3473 * a pointer to address parameter.
3474 */
3475 length = sizeof(struct sctp_addip_chunk);
3476 addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
3477 asconf_len -= length;
3478
3479 /* Skip the address parameter in the last asconf sent and store a
3480 * pointer to the first asconf parameter.
3481 */
3482 length = ntohs(addr_param->p.length);
3483 asconf_param = (void *)addr_param + length;
3484 asconf_len -= length;
3485
3486 /* ADDIP 4.1
3487 * A8) If there is no response(s) to specific TLV parameter(s), and no
3488 * failures are indicated, then all request(s) are considered
3489 * successful.
3490 */
3491 if (asconf_ack->skb->len == sizeof(struct sctp_addiphdr))
3492 all_param_pass = 1;
3493
3494 /* Process the TLVs contained in the last sent ASCONF chunk. */
3495 while (asconf_len > 0) {
3496 if (all_param_pass)
3497 err_code = SCTP_ERROR_NO_ERROR;
3498 else {
3499 err_code = sctp_get_asconf_response(asconf_ack,
3500 asconf_param,
3501 no_err);
3502 if (no_err && (SCTP_ERROR_NO_ERROR != err_code))
3503 no_err = 0;
3504 }
3505
3506 switch (err_code) {
3507 case SCTP_ERROR_NO_ERROR:
3508 sctp_asconf_param_success(asoc, asconf_param);
3509 break;
3510
3511 case SCTP_ERROR_RSRC_LOW:
3512 retval = 1;
3513 break;
3514
3515 case SCTP_ERROR_UNKNOWN_PARAM:
3516 /* Disable sending this type of asconf parameter in
3517 * future.
3518 */
3519 asoc->peer.addip_disabled_mask |=
3520 asconf_param->param_hdr.type;
3521 break;
3522
3523 case SCTP_ERROR_REQ_REFUSED:
3524 case SCTP_ERROR_DEL_LAST_IP:
3525 case SCTP_ERROR_DEL_SRC_IP:
3526 default:
3527 break;
3528 }
3529
3530 /* Skip the processed asconf parameter and move to the next
3531 * one.
3532 */
3533 length = ntohs(asconf_param->param_hdr.length);
3534 asconf_param = (void *)asconf_param + length;
3535 asconf_len -= length;
3536 }
3537
3538 if (no_err && asoc->src_out_of_asoc_ok) {
3539 asoc->src_out_of_asoc_ok = 0;
3540 sctp_transport_immediate_rtx(asoc->peer.primary_path);
3541 }
3542
3543 /* Free the cached last sent asconf chunk. */
3544 list_del_init(&asconf->transmitted_list);
3545 sctp_chunk_free(asconf);
3546 asoc->addip_last_asconf = NULL;
3547
3548 return retval;
3549}
3550
3551/* Make a FWD TSN chunk. */
3552struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
3553 __u32 new_cum_tsn, size_t nstreams,
3554 struct sctp_fwdtsn_skip *skiplist)
3555{
3556 struct sctp_chunk *retval = NULL;
3557 struct sctp_fwdtsn_hdr ftsn_hdr;
3558 struct sctp_fwdtsn_skip skip;
3559 size_t hint;
3560 int i;
3561
3562 hint = (nstreams + 1) * sizeof(__u32);
3563
3564 retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint, GFP_ATOMIC);
3565
3566 if (!retval)
3567 return NULL;
3568
3569 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn);
3570 retval->subh.fwdtsn_hdr =
3571 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr);
3572
3573 for (i = 0; i < nstreams; i++) {
3574 skip.stream = skiplist[i].stream;
3575 skip.ssn = skiplist[i].ssn;
3576 sctp_addto_chunk(retval, sizeof(skip), &skip);
3577 }
3578
3579 return retval;
3580}
3581
3582struct sctp_chunk *sctp_make_ifwdtsn(const struct sctp_association *asoc,
3583 __u32 new_cum_tsn, size_t nstreams,
3584 struct sctp_ifwdtsn_skip *skiplist)
3585{
3586 struct sctp_chunk *retval = NULL;
3587 struct sctp_ifwdtsn_hdr ftsn_hdr;
3588 size_t hint;
3589
3590 hint = (nstreams + 1) * sizeof(__u32);
3591
3592 retval = sctp_make_control(asoc, SCTP_CID_I_FWD_TSN, 0, hint,
3593 GFP_ATOMIC);
3594 if (!retval)
3595 return NULL;
3596
3597 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn);
3598 retval->subh.ifwdtsn_hdr =
3599 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr);
3600
3601 sctp_addto_chunk(retval, nstreams * sizeof(skiplist[0]), skiplist);
3602
3603 return retval;
3604}
3605
3606/* RE-CONFIG 3.1 (RE-CONFIG chunk)
3607 * 0 1 2 3
3608 * 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
3609 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3610 * | Type = 130 | Chunk Flags | Chunk Length |
3611 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3612 * \ \
3613 * / Re-configuration Parameter /
3614 * \ \
3615 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3616 * \ \
3617 * / Re-configuration Parameter (optional) /
3618 * \ \
3619 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3620 */
3621static struct sctp_chunk *sctp_make_reconf(const struct sctp_association *asoc,
3622 int length)
3623{
3624 struct sctp_reconf_chunk *reconf;
3625 struct sctp_chunk *retval;
3626
3627 retval = sctp_make_control(asoc, SCTP_CID_RECONF, 0, length,
3628 GFP_ATOMIC);
3629 if (!retval)
3630 return NULL;
3631
3632 reconf = (struct sctp_reconf_chunk *)retval->chunk_hdr;
3633 retval->param_hdr.v = reconf->params;
3634
3635 return retval;
3636}
3637
3638/* RE-CONFIG 4.1 (STREAM OUT RESET)
3639 * 0 1 2 3
3640 * 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
3641 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3642 * | Parameter Type = 13 | Parameter Length = 16 + 2 * N |
3643 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3644 * | Re-configuration Request Sequence Number |
3645 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3646 * | Re-configuration Response Sequence Number |
3647 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3648 * | Sender's Last Assigned TSN |
3649 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3650 * | Stream Number 1 (optional) | Stream Number 2 (optional) |
3651 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3652 * / ...... /
3653 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3654 * | Stream Number N-1 (optional) | Stream Number N (optional) |
3655 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3656 *
3657 * RE-CONFIG 4.2 (STREAM IN RESET)
3658 * 0 1 2 3
3659 * 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
3660 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3661 * | Parameter Type = 14 | Parameter Length = 8 + 2 * N |
3662 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3663 * | Re-configuration Request Sequence Number |
3664 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3665 * | Stream Number 1 (optional) | Stream Number 2 (optional) |
3666 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3667 * / ...... /
3668 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3669 * | Stream Number N-1 (optional) | Stream Number N (optional) |
3670 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3671 */
3672struct sctp_chunk *sctp_make_strreset_req(
3673 const struct sctp_association *asoc,
3674 __u16 stream_num, __be16 *stream_list,
3675 bool out, bool in)
3676{
3677 __u16 stream_len = stream_num * sizeof(__u16);
3678 struct sctp_strreset_outreq outreq;
3679 struct sctp_strreset_inreq inreq;
3680 struct sctp_chunk *retval;
3681 __u16 outlen, inlen;
3682
3683 outlen = (sizeof(outreq) + stream_len) * out;
3684 inlen = (sizeof(inreq) + stream_len) * in;
3685
3686 retval = sctp_make_reconf(asoc, outlen + inlen);
3687 if (!retval)
3688 return NULL;
3689
3690 if (outlen) {
3691 outreq.param_hdr.type = SCTP_PARAM_RESET_OUT_REQUEST;
3692 outreq.param_hdr.length = htons(outlen);
3693 outreq.request_seq = htonl(asoc->strreset_outseq);
3694 outreq.response_seq = htonl(asoc->strreset_inseq - 1);
3695 outreq.send_reset_at_tsn = htonl(asoc->next_tsn - 1);
3696
3697 sctp_addto_chunk(retval, sizeof(outreq), &outreq);
3698
3699 if (stream_len)
3700 sctp_addto_chunk(retval, stream_len, stream_list);
3701 }
3702
3703 if (inlen) {
3704 inreq.param_hdr.type = SCTP_PARAM_RESET_IN_REQUEST;
3705 inreq.param_hdr.length = htons(inlen);
3706 inreq.request_seq = htonl(asoc->strreset_outseq + out);
3707
3708 sctp_addto_chunk(retval, sizeof(inreq), &inreq);
3709
3710 if (stream_len)
3711 sctp_addto_chunk(retval, stream_len, stream_list);
3712 }
3713
3714 return retval;
3715}
3716
3717/* RE-CONFIG 4.3 (SSN/TSN RESET ALL)
3718 * 0 1 2 3
3719 * 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
3720 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3721 * | Parameter Type = 15 | Parameter Length = 8 |
3722 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3723 * | Re-configuration Request Sequence Number |
3724 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3725 */
3726struct sctp_chunk *sctp_make_strreset_tsnreq(
3727 const struct sctp_association *asoc)
3728{
3729 struct sctp_strreset_tsnreq tsnreq;
3730 __u16 length = sizeof(tsnreq);
3731 struct sctp_chunk *retval;
3732
3733 retval = sctp_make_reconf(asoc, length);
3734 if (!retval)
3735 return NULL;
3736
3737 tsnreq.param_hdr.type = SCTP_PARAM_RESET_TSN_REQUEST;
3738 tsnreq.param_hdr.length = htons(length);
3739 tsnreq.request_seq = htonl(asoc->strreset_outseq);
3740
3741 sctp_addto_chunk(retval, sizeof(tsnreq), &tsnreq);
3742
3743 return retval;
3744}
3745
3746/* RE-CONFIG 4.5/4.6 (ADD STREAM)
3747 * 0 1 2 3
3748 * 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
3749 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3750 * | Parameter Type = 17 | Parameter Length = 12 |
3751 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3752 * | Re-configuration Request Sequence Number |
3753 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3754 * | Number of new streams | Reserved |
3755 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3756 */
3757struct sctp_chunk *sctp_make_strreset_addstrm(
3758 const struct sctp_association *asoc,
3759 __u16 out, __u16 in)
3760{
3761 struct sctp_strreset_addstrm addstrm;
3762 __u16 size = sizeof(addstrm);
3763 struct sctp_chunk *retval;
3764
3765 retval = sctp_make_reconf(asoc, (!!out + !!in) * size);
3766 if (!retval)
3767 return NULL;
3768
3769 if (out) {
3770 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_OUT_STREAMS;
3771 addstrm.param_hdr.length = htons(size);
3772 addstrm.number_of_streams = htons(out);
3773 addstrm.request_seq = htonl(asoc->strreset_outseq);
3774 addstrm.reserved = 0;
3775
3776 sctp_addto_chunk(retval, size, &addstrm);
3777 }
3778
3779 if (in) {
3780 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_IN_STREAMS;
3781 addstrm.param_hdr.length = htons(size);
3782 addstrm.number_of_streams = htons(in);
3783 addstrm.request_seq = htonl(asoc->strreset_outseq + !!out);
3784 addstrm.reserved = 0;
3785
3786 sctp_addto_chunk(retval, size, &addstrm);
3787 }
3788
3789 return retval;
3790}
3791
3792/* RE-CONFIG 4.4 (RESP)
3793 * 0 1 2 3
3794 * 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
3795 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3796 * | Parameter Type = 16 | Parameter Length |
3797 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3798 * | Re-configuration Response Sequence Number |
3799 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3800 * | Result |
3801 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3802 */
3803struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc,
3804 __u32 result, __u32 sn)
3805{
3806 struct sctp_strreset_resp resp;
3807 __u16 length = sizeof(resp);
3808 struct sctp_chunk *retval;
3809
3810 retval = sctp_make_reconf(asoc, length);
3811 if (!retval)
3812 return NULL;
3813
3814 resp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE;
3815 resp.param_hdr.length = htons(length);
3816 resp.response_seq = htonl(sn);
3817 resp.result = htonl(result);
3818
3819 sctp_addto_chunk(retval, sizeof(resp), &resp);
3820
3821 return retval;
3822}
3823
3824/* RE-CONFIG 4.4 OPTIONAL (TSNRESP)
3825 * 0 1 2 3
3826 * 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
3827 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3828 * | Parameter Type = 16 | Parameter Length |
3829 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3830 * | Re-configuration Response Sequence Number |
3831 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3832 * | Result |
3833 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3834 * | Sender's Next TSN (optional) |
3835 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3836 * | Receiver's Next TSN (optional) |
3837 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3838 */
3839struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc,
3840 __u32 result, __u32 sn,
3841 __u32 sender_tsn,
3842 __u32 receiver_tsn)
3843{
3844 struct sctp_strreset_resptsn tsnresp;
3845 __u16 length = sizeof(tsnresp);
3846 struct sctp_chunk *retval;
3847
3848 retval = sctp_make_reconf(asoc, length);
3849 if (!retval)
3850 return NULL;
3851
3852 tsnresp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE;
3853 tsnresp.param_hdr.length = htons(length);
3854
3855 tsnresp.response_seq = htonl(sn);
3856 tsnresp.result = htonl(result);
3857 tsnresp.senders_next_tsn = htonl(sender_tsn);
3858 tsnresp.receivers_next_tsn = htonl(receiver_tsn);
3859
3860 sctp_addto_chunk(retval, sizeof(tsnresp), &tsnresp);
3861
3862 return retval;
3863}
3864
3865bool sctp_verify_reconf(const struct sctp_association *asoc,
3866 struct sctp_chunk *chunk,
3867 struct sctp_paramhdr **errp)
3868{
3869 struct sctp_reconf_chunk *hdr;
3870 union sctp_params param;
3871 __be16 last = 0;
3872 __u16 cnt = 0;
3873
3874 hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr;
3875 sctp_walk_params(param, hdr, params) {
3876 __u16 length = ntohs(param.p->length);
3877
3878 *errp = param.p;
3879 if (cnt++ > 2)
3880 return false;
3881 switch (param.p->type) {
3882 case SCTP_PARAM_RESET_OUT_REQUEST:
3883 if (length < sizeof(struct sctp_strreset_outreq) ||
3884 (last && last != SCTP_PARAM_RESET_RESPONSE &&
3885 last != SCTP_PARAM_RESET_IN_REQUEST))
3886 return false;
3887 break;
3888 case SCTP_PARAM_RESET_IN_REQUEST:
3889 if (length < sizeof(struct sctp_strreset_inreq) ||
3890 (last && last != SCTP_PARAM_RESET_OUT_REQUEST))
3891 return false;
3892 break;
3893 case SCTP_PARAM_RESET_RESPONSE:
3894 if ((length != sizeof(struct sctp_strreset_resp) &&
3895 length != sizeof(struct sctp_strreset_resptsn)) ||
3896 (last && last != SCTP_PARAM_RESET_RESPONSE &&
3897 last != SCTP_PARAM_RESET_OUT_REQUEST))
3898 return false;
3899 break;
3900 case SCTP_PARAM_RESET_TSN_REQUEST:
3901 if (length !=
3902 sizeof(struct sctp_strreset_tsnreq) || last)
3903 return false;
3904 break;
3905 case SCTP_PARAM_RESET_ADD_IN_STREAMS:
3906 if (length != sizeof(struct sctp_strreset_addstrm) ||
3907 (last && last != SCTP_PARAM_RESET_ADD_OUT_STREAMS))
3908 return false;
3909 break;
3910 case SCTP_PARAM_RESET_ADD_OUT_STREAMS:
3911 if (length != sizeof(struct sctp_strreset_addstrm) ||
3912 (last && last != SCTP_PARAM_RESET_ADD_IN_STREAMS))
3913 return false;
3914 break;
3915 default:
3916 return false;
3917 }
3918
3919 last = param.p->type;
3920 }
3921
3922 return true;
3923}