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[thirdparty/linux.git] / net / sctp / sm_make_chunk.c
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
49 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc,
50 __u8 type, __u8 flags, int paylen,
51 gfp_t gfp);
52 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc,
53 __u8 flags, int paylen, gfp_t gfp);
54 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc,
55 __u8 type, __u8 flags, int paylen,
56 gfp_t gfp);
57 static 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);
63 static int sctp_process_param(struct sctp_association *asoc,
64 union sctp_params param,
65 const union sctp_addr *peer_addr,
66 gfp_t gfp);
67 static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
68 const void *data);
69
70 /* Control chunk destructor */
71 static 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
97 static 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? */
119 int 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 */
131 static const struct sctp_paramhdr ecap_param = {
132 SCTP_PARAM_ECN_CAPABLE,
133 cpu_to_be16(sizeof(struct sctp_paramhdr)),
134 };
135 static 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 */
143 int 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 */
206 struct 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 }
374 nodata:
375 kfree(addrs.v);
376 return retval;
377 }
378
379 struct 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
526 nomem_chunk:
527 kfree(cookie);
528 nomem_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 */
567 struct 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
597 nodata:
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 */
619 struct 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 */
666 struct 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
696 nodata:
697 return retval;
698 }
699
700 /* Make an ECNE chunk. This is a congestion experienced report. */
701 struct 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
715 nodata:
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 */
722 struct 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 */
754 struct 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 }
849 nodata:
850 return retval;
851 }
852
853 /* Make a SHUTDOWN chunk. */
854 struct 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;
874 nodata:
875 return retval;
876 }
877
878 struct 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
901 struct 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 */
935 struct 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. */
972 struct 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
1003 no_mem:
1004 return retval;
1005 }
1006
1007 /* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */
1008 struct 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
1040 err_copy:
1041 kfree(payload);
1042 err_payload:
1043 sctp_chunk_free(retval);
1044 retval = NULL;
1045 err_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 */
1052 static 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. */
1073 struct 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
1095 end:
1096 return retval;
1097 }
1098
1099 struct 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
1118 nodata:
1119 return retval;
1120 }
1121
1122 struct 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
1137 nodata:
1138 return retval;
1139 }
1140
1141 /* Make a HEARTBEAT chunk. */
1142 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc,
1143 const struct sctp_transport *transport)
1144 {
1145 struct sctp_sender_hb_info hbinfo;
1146 struct sctp_chunk *retval;
1147
1148 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT, 0,
1149 sizeof(hbinfo), GFP_ATOMIC);
1150
1151 if (!retval)
1152 goto nodata;
1153
1154 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO;
1155 hbinfo.param_hdr.length = htons(sizeof(hbinfo));
1156 hbinfo.daddr = transport->ipaddr;
1157 hbinfo.sent_at = jiffies;
1158 hbinfo.hb_nonce = transport->hb_nonce;
1159
1160 /* Cast away the 'const', as this is just telling the chunk
1161 * what transport it belongs to.
1162 */
1163 retval->transport = (struct sctp_transport *) transport;
1164 retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo),
1165 &hbinfo);
1166
1167 nodata:
1168 return retval;
1169 }
1170
1171 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc,
1172 const struct sctp_chunk *chunk,
1173 const void *payload,
1174 const size_t paylen)
1175 {
1176 struct sctp_chunk *retval;
1177
1178 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen,
1179 GFP_ATOMIC);
1180 if (!retval)
1181 goto nodata;
1182
1183 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload);
1184
1185 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
1186 *
1187 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1188 * HEARTBEAT ACK, * etc.) to the same destination transport
1189 * address from which it * received the DATA or control chunk
1190 * to which it is replying.
1191 *
1192 * [HBACK back to where the HEARTBEAT came from.]
1193 */
1194 if (chunk)
1195 retval->transport = chunk->transport;
1196
1197 nodata:
1198 return retval;
1199 }
1200
1201 /* Create an Operation Error chunk with the specified space reserved.
1202 * This routine can be used for containing multiple causes in the chunk.
1203 */
1204 static struct sctp_chunk *sctp_make_op_error_space(
1205 const struct sctp_association *asoc,
1206 const struct sctp_chunk *chunk,
1207 size_t size)
1208 {
1209 struct sctp_chunk *retval;
1210
1211 retval = sctp_make_control(asoc, SCTP_CID_ERROR, 0,
1212 sizeof(struct sctp_errhdr) + size,
1213 GFP_ATOMIC);
1214 if (!retval)
1215 goto nodata;
1216
1217 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
1218 *
1219 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1220 * HEARTBEAT ACK, etc.) to the same destination transport
1221 * address from which it received the DATA or control chunk
1222 * to which it is replying.
1223 *
1224 */
1225 if (chunk)
1226 retval->transport = chunk->transport;
1227
1228 nodata:
1229 return retval;
1230 }
1231
1232 /* Create an Operation Error chunk of a fixed size, specifically,
1233 * min(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT) - overheads.
1234 * This is a helper function to allocate an error chunk for for those
1235 * invalid parameter codes in which we may not want to report all the
1236 * errors, if the incoming chunk is large. If it can't fit in a single
1237 * packet, we ignore it.
1238 */
1239 static inline struct sctp_chunk *sctp_make_op_error_limited(
1240 const struct sctp_association *asoc,
1241 const struct sctp_chunk *chunk)
1242 {
1243 size_t size = SCTP_DEFAULT_MAXSEGMENT;
1244 struct sctp_sock *sp = NULL;
1245
1246 if (asoc) {
1247 size = min_t(size_t, size, asoc->pathmtu);
1248 sp = sctp_sk(asoc->base.sk);
1249 }
1250
1251 size = sctp_mtu_payload(sp, size, sizeof(struct sctp_errhdr));
1252
1253 return sctp_make_op_error_space(asoc, chunk, size);
1254 }
1255
1256 /* Create an Operation Error chunk. */
1257 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc,
1258 const struct sctp_chunk *chunk,
1259 __be16 cause_code, const void *payload,
1260 size_t paylen, size_t reserve_tail)
1261 {
1262 struct sctp_chunk *retval;
1263
1264 retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail);
1265 if (!retval)
1266 goto nodata;
1267
1268 sctp_init_cause(retval, cause_code, paylen + reserve_tail);
1269 sctp_addto_chunk(retval, paylen, payload);
1270 if (reserve_tail)
1271 sctp_addto_param(retval, reserve_tail, NULL);
1272
1273 nodata:
1274 return retval;
1275 }
1276
1277 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc,
1278 __u16 key_id)
1279 {
1280 struct sctp_authhdr auth_hdr;
1281 struct sctp_hmac *hmac_desc;
1282 struct sctp_chunk *retval;
1283
1284 /* Get the first hmac that the peer told us to use */
1285 hmac_desc = sctp_auth_asoc_get_hmac(asoc);
1286 if (unlikely(!hmac_desc))
1287 return NULL;
1288
1289 retval = sctp_make_control(asoc, SCTP_CID_AUTH, 0,
1290 hmac_desc->hmac_len + sizeof(auth_hdr),
1291 GFP_ATOMIC);
1292 if (!retval)
1293 return NULL;
1294
1295 auth_hdr.hmac_id = htons(hmac_desc->hmac_id);
1296 auth_hdr.shkey_id = htons(key_id);
1297
1298 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(auth_hdr),
1299 &auth_hdr);
1300
1301 skb_put_zero(retval->skb, hmac_desc->hmac_len);
1302
1303 /* Adjust the chunk header to include the empty MAC */
1304 retval->chunk_hdr->length =
1305 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len);
1306 retval->chunk_end = skb_tail_pointer(retval->skb);
1307
1308 return retval;
1309 }
1310
1311
1312 /********************************************************************
1313 * 2nd Level Abstractions
1314 ********************************************************************/
1315
1316 /* Turn an skb into a chunk.
1317 * FIXME: Eventually move the structure directly inside the skb->cb[].
1318 *
1319 * sctpimpguide-05.txt Section 2.8.2
1320 * M1) Each time a new DATA chunk is transmitted
1321 * set the 'TSN.Missing.Report' count for that TSN to 0. The
1322 * 'TSN.Missing.Report' count will be used to determine missing chunks
1323 * and when to fast retransmit.
1324 *
1325 */
1326 struct sctp_chunk *sctp_chunkify(struct sk_buff *skb,
1327 const struct sctp_association *asoc,
1328 struct sock *sk, gfp_t gfp)
1329 {
1330 struct sctp_chunk *retval;
1331
1332 retval = kmem_cache_zalloc(sctp_chunk_cachep, gfp);
1333
1334 if (!retval)
1335 goto nodata;
1336 if (!sk)
1337 pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb);
1338
1339 INIT_LIST_HEAD(&retval->list);
1340 retval->skb = skb;
1341 retval->asoc = (struct sctp_association *)asoc;
1342 retval->singleton = 1;
1343
1344 retval->fast_retransmit = SCTP_CAN_FRTX;
1345
1346 /* Polish the bead hole. */
1347 INIT_LIST_HEAD(&retval->transmitted_list);
1348 INIT_LIST_HEAD(&retval->frag_list);
1349 SCTP_DBG_OBJCNT_INC(chunk);
1350 refcount_set(&retval->refcnt, 1);
1351
1352 nodata:
1353 return retval;
1354 }
1355
1356 /* Set chunk->source and dest based on the IP header in chunk->skb. */
1357 void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src,
1358 union sctp_addr *dest)
1359 {
1360 memcpy(&chunk->source, src, sizeof(union sctp_addr));
1361 memcpy(&chunk->dest, dest, sizeof(union sctp_addr));
1362 }
1363
1364 /* Extract the source address from a chunk. */
1365 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk)
1366 {
1367 /* If we have a known transport, use that. */
1368 if (chunk->transport) {
1369 return &chunk->transport->ipaddr;
1370 } else {
1371 /* Otherwise, extract it from the IP header. */
1372 return &chunk->source;
1373 }
1374 }
1375
1376 /* Create a new chunk, setting the type and flags headers from the
1377 * arguments, reserving enough space for a 'paylen' byte payload.
1378 */
1379 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc,
1380 __u8 type, __u8 flags, int paylen,
1381 gfp_t gfp)
1382 {
1383 struct sctp_chunkhdr *chunk_hdr;
1384 struct sctp_chunk *retval;
1385 struct sk_buff *skb;
1386 struct sock *sk;
1387 int chunklen;
1388
1389 chunklen = SCTP_PAD4(sizeof(*chunk_hdr) + paylen);
1390 if (chunklen > SCTP_MAX_CHUNK_LEN)
1391 goto nodata;
1392
1393 /* No need to allocate LL here, as this is only a chunk. */
1394 skb = alloc_skb(chunklen, gfp);
1395 if (!skb)
1396 goto nodata;
1397
1398 /* Make room for the chunk header. */
1399 chunk_hdr = (struct sctp_chunkhdr *)skb_put(skb, sizeof(*chunk_hdr));
1400 chunk_hdr->type = type;
1401 chunk_hdr->flags = flags;
1402 chunk_hdr->length = htons(sizeof(*chunk_hdr));
1403
1404 sk = asoc ? asoc->base.sk : NULL;
1405 retval = sctp_chunkify(skb, asoc, sk, gfp);
1406 if (!retval) {
1407 kfree_skb(skb);
1408 goto nodata;
1409 }
1410
1411 retval->chunk_hdr = chunk_hdr;
1412 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(*chunk_hdr);
1413
1414 /* Determine if the chunk needs to be authenticated */
1415 if (sctp_auth_send_cid(type, asoc))
1416 retval->auth = 1;
1417
1418 return retval;
1419 nodata:
1420 return NULL;
1421 }
1422
1423 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc,
1424 __u8 flags, int paylen, gfp_t gfp)
1425 {
1426 return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen, gfp);
1427 }
1428
1429 struct sctp_chunk *sctp_make_idata(const struct sctp_association *asoc,
1430 __u8 flags, int paylen, gfp_t gfp)
1431 {
1432 return _sctp_make_chunk(asoc, SCTP_CID_I_DATA, flags, paylen, gfp);
1433 }
1434
1435 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc,
1436 __u8 type, __u8 flags, int paylen,
1437 gfp_t gfp)
1438 {
1439 struct sctp_chunk *chunk;
1440
1441 chunk = _sctp_make_chunk(asoc, type, flags, paylen, gfp);
1442 if (chunk)
1443 sctp_control_set_owner_w(chunk);
1444
1445 return chunk;
1446 }
1447
1448 /* Release the memory occupied by a chunk. */
1449 static void sctp_chunk_destroy(struct sctp_chunk *chunk)
1450 {
1451 BUG_ON(!list_empty(&chunk->list));
1452 list_del_init(&chunk->transmitted_list);
1453
1454 consume_skb(chunk->skb);
1455 consume_skb(chunk->auth_chunk);
1456
1457 SCTP_DBG_OBJCNT_DEC(chunk);
1458 kmem_cache_free(sctp_chunk_cachep, chunk);
1459 }
1460
1461 /* Possibly, free the chunk. */
1462 void sctp_chunk_free(struct sctp_chunk *chunk)
1463 {
1464 /* Release our reference on the message tracker. */
1465 if (chunk->msg)
1466 sctp_datamsg_put(chunk->msg);
1467
1468 sctp_chunk_put(chunk);
1469 }
1470
1471 /* Grab a reference to the chunk. */
1472 void sctp_chunk_hold(struct sctp_chunk *ch)
1473 {
1474 refcount_inc(&ch->refcnt);
1475 }
1476
1477 /* Release a reference to the chunk. */
1478 void sctp_chunk_put(struct sctp_chunk *ch)
1479 {
1480 if (refcount_dec_and_test(&ch->refcnt))
1481 sctp_chunk_destroy(ch);
1482 }
1483
1484 /* Append bytes to the end of a chunk. Will panic if chunk is not big
1485 * enough.
1486 */
1487 void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data)
1488 {
1489 int chunklen = ntohs(chunk->chunk_hdr->length);
1490 int padlen = SCTP_PAD4(chunklen) - chunklen;
1491 void *target;
1492
1493 skb_put_zero(chunk->skb, padlen);
1494 target = skb_put_data(chunk->skb, data, len);
1495
1496 /* Adjust the chunk length field. */
1497 chunk->chunk_hdr->length = htons(chunklen + padlen + len);
1498 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1499
1500 return target;
1501 }
1502
1503 /* Append bytes from user space to the end of a chunk. Will panic if
1504 * chunk is not big enough.
1505 * Returns a kernel err value.
1506 */
1507 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
1508 struct iov_iter *from)
1509 {
1510 void *target;
1511
1512 /* Make room in chunk for data. */
1513 target = skb_put(chunk->skb, len);
1514
1515 /* Copy data (whole iovec) into chunk */
1516 if (!copy_from_iter_full(target, len, from))
1517 return -EFAULT;
1518
1519 /* Adjust the chunk length field. */
1520 chunk->chunk_hdr->length =
1521 htons(ntohs(chunk->chunk_hdr->length) + len);
1522 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1523
1524 return 0;
1525 }
1526
1527 /* Helper function to assign a TSN if needed. This assumes that both
1528 * the data_hdr and association have already been assigned.
1529 */
1530 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk)
1531 {
1532 struct sctp_stream *stream;
1533 struct sctp_chunk *lchunk;
1534 struct sctp_datamsg *msg;
1535 __u16 ssn, sid;
1536
1537 if (chunk->has_ssn)
1538 return;
1539
1540 /* All fragments will be on the same stream */
1541 sid = ntohs(chunk->subh.data_hdr->stream);
1542 stream = &chunk->asoc->stream;
1543
1544 /* Now assign the sequence number to the entire message.
1545 * All fragments must have the same stream sequence number.
1546 */
1547 msg = chunk->msg;
1548 list_for_each_entry(lchunk, &msg->chunks, frag_list) {
1549 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
1550 ssn = 0;
1551 } else {
1552 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG)
1553 ssn = sctp_ssn_next(stream, out, sid);
1554 else
1555 ssn = sctp_ssn_peek(stream, out, sid);
1556 }
1557
1558 lchunk->subh.data_hdr->ssn = htons(ssn);
1559 lchunk->has_ssn = 1;
1560 }
1561 }
1562
1563 /* Helper function to assign a TSN if needed. This assumes that both
1564 * the data_hdr and association have already been assigned.
1565 */
1566 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk)
1567 {
1568 if (!chunk->has_tsn) {
1569 /* This is the last possible instant to
1570 * assign a TSN.
1571 */
1572 chunk->subh.data_hdr->tsn =
1573 htonl(sctp_association_get_next_tsn(chunk->asoc));
1574 chunk->has_tsn = 1;
1575 }
1576 }
1577
1578 /* Create a CLOSED association to use with an incoming packet. */
1579 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep,
1580 struct sctp_chunk *chunk,
1581 gfp_t gfp)
1582 {
1583 struct sctp_association *asoc;
1584 enum sctp_scope scope;
1585 struct sk_buff *skb;
1586
1587 /* Create the bare association. */
1588 scope = sctp_scope(sctp_source(chunk));
1589 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp);
1590 if (!asoc)
1591 goto nodata;
1592 asoc->temp = 1;
1593 skb = chunk->skb;
1594 /* Create an entry for the source address of the packet. */
1595 SCTP_INPUT_CB(skb)->af->from_skb(&asoc->c.peer_addr, skb, 1);
1596
1597 nodata:
1598 return asoc;
1599 }
1600
1601 /* Build a cookie representing asoc.
1602 * This INCLUDES the param header needed to put the cookie in the INIT ACK.
1603 */
1604 static struct sctp_cookie_param *sctp_pack_cookie(
1605 const struct sctp_endpoint *ep,
1606 const struct sctp_association *asoc,
1607 const struct sctp_chunk *init_chunk,
1608 int *cookie_len, const __u8 *raw_addrs,
1609 int addrs_len)
1610 {
1611 struct sctp_signed_cookie *cookie;
1612 struct sctp_cookie_param *retval;
1613 int headersize, bodysize;
1614
1615 /* Header size is static data prior to the actual cookie, including
1616 * any padding.
1617 */
1618 headersize = sizeof(struct sctp_paramhdr) +
1619 (sizeof(struct sctp_signed_cookie) -
1620 sizeof(struct sctp_cookie));
1621 bodysize = sizeof(struct sctp_cookie)
1622 + ntohs(init_chunk->chunk_hdr->length) + addrs_len;
1623
1624 /* Pad out the cookie to a multiple to make the signature
1625 * functions simpler to write.
1626 */
1627 if (bodysize % SCTP_COOKIE_MULTIPLE)
1628 bodysize += SCTP_COOKIE_MULTIPLE
1629 - (bodysize % SCTP_COOKIE_MULTIPLE);
1630 *cookie_len = headersize + bodysize;
1631
1632 /* Clear this memory since we are sending this data structure
1633 * out on the network.
1634 */
1635 retval = kzalloc(*cookie_len, GFP_ATOMIC);
1636 if (!retval)
1637 goto nodata;
1638
1639 cookie = (struct sctp_signed_cookie *) retval->body;
1640
1641 /* Set up the parameter header. */
1642 retval->p.type = SCTP_PARAM_STATE_COOKIE;
1643 retval->p.length = htons(*cookie_len);
1644
1645 /* Copy the cookie part of the association itself. */
1646 cookie->c = asoc->c;
1647 /* Save the raw address list length in the cookie. */
1648 cookie->c.raw_addr_list_len = addrs_len;
1649
1650 /* Remember PR-SCTP capability. */
1651 cookie->c.prsctp_capable = asoc->peer.prsctp_capable;
1652
1653 /* Save adaptation indication in the cookie. */
1654 cookie->c.adaptation_ind = asoc->peer.adaptation_ind;
1655
1656 /* Set an expiration time for the cookie. */
1657 cookie->c.expiration = ktime_add(asoc->cookie_life,
1658 ktime_get_real());
1659
1660 /* Copy the peer's init packet. */
1661 memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr,
1662 ntohs(init_chunk->chunk_hdr->length));
1663
1664 /* Copy the raw local address list of the association. */
1665 memcpy((__u8 *)&cookie->c.peer_init[0] +
1666 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len);
1667
1668 if (sctp_sk(ep->base.sk)->hmac) {
1669 SHASH_DESC_ON_STACK(desc, sctp_sk(ep->base.sk)->hmac);
1670 int err;
1671
1672 /* Sign the message. */
1673 desc->tfm = sctp_sk(ep->base.sk)->hmac;
1674
1675 err = crypto_shash_setkey(desc->tfm, ep->secret_key,
1676 sizeof(ep->secret_key)) ?:
1677 crypto_shash_digest(desc, (u8 *)&cookie->c, bodysize,
1678 cookie->signature);
1679 shash_desc_zero(desc);
1680 if (err)
1681 goto free_cookie;
1682 }
1683
1684 return retval;
1685
1686 free_cookie:
1687 kfree(retval);
1688 nodata:
1689 *cookie_len = 0;
1690 return NULL;
1691 }
1692
1693 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */
1694 struct sctp_association *sctp_unpack_cookie(
1695 const struct sctp_endpoint *ep,
1696 const struct sctp_association *asoc,
1697 struct sctp_chunk *chunk, gfp_t gfp,
1698 int *error, struct sctp_chunk **errp)
1699 {
1700 struct sctp_association *retval = NULL;
1701 int headersize, bodysize, fixed_size;
1702 struct sctp_signed_cookie *cookie;
1703 struct sk_buff *skb = chunk->skb;
1704 struct sctp_cookie *bear_cookie;
1705 __u8 *digest = ep->digest;
1706 enum sctp_scope scope;
1707 unsigned int len;
1708 ktime_t kt;
1709
1710 /* Header size is static data prior to the actual cookie, including
1711 * any padding.
1712 */
1713 headersize = sizeof(struct sctp_chunkhdr) +
1714 (sizeof(struct sctp_signed_cookie) -
1715 sizeof(struct sctp_cookie));
1716 bodysize = ntohs(chunk->chunk_hdr->length) - headersize;
1717 fixed_size = headersize + sizeof(struct sctp_cookie);
1718
1719 /* Verify that the chunk looks like it even has a cookie.
1720 * There must be enough room for our cookie and our peer's
1721 * INIT chunk.
1722 */
1723 len = ntohs(chunk->chunk_hdr->length);
1724 if (len < fixed_size + sizeof(struct sctp_chunkhdr))
1725 goto malformed;
1726
1727 /* Verify that the cookie has been padded out. */
1728 if (bodysize % SCTP_COOKIE_MULTIPLE)
1729 goto malformed;
1730
1731 /* Process the cookie. */
1732 cookie = chunk->subh.cookie_hdr;
1733 bear_cookie = &cookie->c;
1734
1735 if (!sctp_sk(ep->base.sk)->hmac)
1736 goto no_hmac;
1737
1738 /* Check the signature. */
1739 {
1740 SHASH_DESC_ON_STACK(desc, sctp_sk(ep->base.sk)->hmac);
1741 int err;
1742
1743 desc->tfm = sctp_sk(ep->base.sk)->hmac;
1744
1745 err = crypto_shash_setkey(desc->tfm, ep->secret_key,
1746 sizeof(ep->secret_key)) ?:
1747 crypto_shash_digest(desc, (u8 *)bear_cookie, bodysize,
1748 digest);
1749 shash_desc_zero(desc);
1750
1751 if (err) {
1752 *error = -SCTP_IERROR_NOMEM;
1753 goto fail;
1754 }
1755 }
1756
1757 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
1758 *error = -SCTP_IERROR_BAD_SIG;
1759 goto fail;
1760 }
1761
1762 no_hmac:
1763 /* IG Section 2.35.2:
1764 * 3) Compare the port numbers and the verification tag contained
1765 * within the COOKIE ECHO chunk to the actual port numbers and the
1766 * verification tag within the SCTP common header of the received
1767 * packet. If these values do not match the packet MUST be silently
1768 * discarded,
1769 */
1770 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) {
1771 *error = -SCTP_IERROR_BAD_TAG;
1772 goto fail;
1773 }
1774
1775 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port ||
1776 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) {
1777 *error = -SCTP_IERROR_BAD_PORTS;
1778 goto fail;
1779 }
1780
1781 /* Check to see if the cookie is stale. If there is already
1782 * an association, there is no need to check cookie's expiration
1783 * for init collision case of lost COOKIE ACK.
1784 * If skb has been timestamped, then use the stamp, otherwise
1785 * use current time. This introduces a small possibility that
1786 * that a cookie may be considered expired, but his would only slow
1787 * down the new association establishment instead of every packet.
1788 */
1789 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP))
1790 kt = skb_get_ktime(skb);
1791 else
1792 kt = ktime_get_real();
1793
1794 if (!asoc && ktime_before(bear_cookie->expiration, kt)) {
1795 suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration));
1796 __be32 n = htonl(usecs);
1797
1798 /*
1799 * Section 3.3.10.3 Stale Cookie Error (3)
1800 *
1801 * Cause of error
1802 * ---------------
1803 * Stale Cookie Error: Indicates the receipt of a valid State
1804 * Cookie that has expired.
1805 */
1806 *errp = sctp_make_op_error(asoc, chunk,
1807 SCTP_ERROR_STALE_COOKIE, &n,
1808 sizeof(n), 0);
1809 if (*errp)
1810 *error = -SCTP_IERROR_STALE_COOKIE;
1811 else
1812 *error = -SCTP_IERROR_NOMEM;
1813
1814 goto fail;
1815 }
1816
1817 /* Make a new base association. */
1818 scope = sctp_scope(sctp_source(chunk));
1819 retval = sctp_association_new(ep, ep->base.sk, scope, gfp);
1820 if (!retval) {
1821 *error = -SCTP_IERROR_NOMEM;
1822 goto fail;
1823 }
1824
1825 /* Set up our peer's port number. */
1826 retval->peer.port = ntohs(chunk->sctp_hdr->source);
1827
1828 /* Populate the association from the cookie. */
1829 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie));
1830
1831 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie,
1832 GFP_ATOMIC) < 0) {
1833 *error = -SCTP_IERROR_NOMEM;
1834 goto fail;
1835 }
1836
1837 /* Also, add the destination address. */
1838 if (list_empty(&retval->base.bind_addr.address_list)) {
1839 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest,
1840 sizeof(chunk->dest), SCTP_ADDR_SRC,
1841 GFP_ATOMIC);
1842 }
1843
1844 retval->next_tsn = retval->c.initial_tsn;
1845 retval->ctsn_ack_point = retval->next_tsn - 1;
1846 retval->addip_serial = retval->c.initial_tsn;
1847 retval->strreset_outseq = retval->c.initial_tsn;
1848 retval->adv_peer_ack_point = retval->ctsn_ack_point;
1849 retval->peer.prsctp_capable = retval->c.prsctp_capable;
1850 retval->peer.adaptation_ind = retval->c.adaptation_ind;
1851
1852 /* The INIT stuff will be done by the side effects. */
1853 return retval;
1854
1855 fail:
1856 if (retval)
1857 sctp_association_free(retval);
1858
1859 return NULL;
1860
1861 malformed:
1862 /* Yikes! The packet is either corrupt or deliberately
1863 * malformed.
1864 */
1865 *error = -SCTP_IERROR_MALFORMED;
1866 goto fail;
1867 }
1868
1869 /********************************************************************
1870 * 3rd Level Abstractions
1871 ********************************************************************/
1872
1873 struct __sctp_missing {
1874 __be32 num_missing;
1875 __be16 type;
1876 } __packed;
1877
1878 /*
1879 * Report a missing mandatory parameter.
1880 */
1881 static int sctp_process_missing_param(const struct sctp_association *asoc,
1882 enum sctp_param paramtype,
1883 struct sctp_chunk *chunk,
1884 struct sctp_chunk **errp)
1885 {
1886 struct __sctp_missing report;
1887 __u16 len;
1888
1889 len = SCTP_PAD4(sizeof(report));
1890
1891 /* Make an ERROR chunk, preparing enough room for
1892 * returning multiple unknown parameters.
1893 */
1894 if (!*errp)
1895 *errp = sctp_make_op_error_space(asoc, chunk, len);
1896
1897 if (*errp) {
1898 report.num_missing = htonl(1);
1899 report.type = paramtype;
1900 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM,
1901 sizeof(report));
1902 sctp_addto_chunk(*errp, sizeof(report), &report);
1903 }
1904
1905 /* Stop processing this chunk. */
1906 return 0;
1907 }
1908
1909 /* Report an Invalid Mandatory Parameter. */
1910 static int sctp_process_inv_mandatory(const struct sctp_association *asoc,
1911 struct sctp_chunk *chunk,
1912 struct sctp_chunk **errp)
1913 {
1914 /* Invalid Mandatory Parameter Error has no payload. */
1915
1916 if (!*errp)
1917 *errp = sctp_make_op_error_space(asoc, chunk, 0);
1918
1919 if (*errp)
1920 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0);
1921
1922 /* Stop processing this chunk. */
1923 return 0;
1924 }
1925
1926 static int sctp_process_inv_paramlength(const struct sctp_association *asoc,
1927 struct sctp_paramhdr *param,
1928 const struct sctp_chunk *chunk,
1929 struct sctp_chunk **errp)
1930 {
1931 /* This is a fatal error. Any accumulated non-fatal errors are
1932 * not reported.
1933 */
1934 if (*errp)
1935 sctp_chunk_free(*errp);
1936
1937 /* Create an error chunk and fill it in with our payload. */
1938 *errp = sctp_make_violation_paramlen(asoc, chunk, param);
1939
1940 return 0;
1941 }
1942
1943
1944 /* Do not attempt to handle the HOST_NAME parm. However, do
1945 * send back an indicator to the peer.
1946 */
1947 static int sctp_process_hn_param(const struct sctp_association *asoc,
1948 union sctp_params param,
1949 struct sctp_chunk *chunk,
1950 struct sctp_chunk **errp)
1951 {
1952 __u16 len = ntohs(param.p->length);
1953
1954 /* Processing of the HOST_NAME parameter will generate an
1955 * ABORT. If we've accumulated any non-fatal errors, they
1956 * would be unrecognized parameters and we should not include
1957 * them in the ABORT.
1958 */
1959 if (*errp)
1960 sctp_chunk_free(*errp);
1961
1962 *errp = sctp_make_op_error(asoc, chunk, SCTP_ERROR_DNS_FAILED,
1963 param.v, len, 0);
1964
1965 /* Stop processing this chunk. */
1966 return 0;
1967 }
1968
1969 static int sctp_verify_ext_param(struct net *net,
1970 const struct sctp_endpoint *ep,
1971 union sctp_params param)
1972 {
1973 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
1974 int have_asconf = 0;
1975 int have_auth = 0;
1976 int i;
1977
1978 for (i = 0; i < num_ext; i++) {
1979 switch (param.ext->chunks[i]) {
1980 case SCTP_CID_AUTH:
1981 have_auth = 1;
1982 break;
1983 case SCTP_CID_ASCONF:
1984 case SCTP_CID_ASCONF_ACK:
1985 have_asconf = 1;
1986 break;
1987 }
1988 }
1989
1990 /* ADD-IP Security: The draft requires us to ABORT or ignore the
1991 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this
1992 * only if ADD-IP is turned on and we are not backward-compatible
1993 * mode.
1994 */
1995 if (net->sctp.addip_noauth)
1996 return 1;
1997
1998 if (ep->asconf_enable && !have_auth && have_asconf)
1999 return 0;
2000
2001 return 1;
2002 }
2003
2004 static void sctp_process_ext_param(struct sctp_association *asoc,
2005 union sctp_params param)
2006 {
2007 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
2008 int i;
2009
2010 for (i = 0; i < num_ext; i++) {
2011 switch (param.ext->chunks[i]) {
2012 case SCTP_CID_RECONF:
2013 if (asoc->ep->reconf_enable)
2014 asoc->peer.reconf_capable = 1;
2015 break;
2016 case SCTP_CID_FWD_TSN:
2017 if (asoc->ep->prsctp_enable)
2018 asoc->peer.prsctp_capable = 1;
2019 break;
2020 case SCTP_CID_AUTH:
2021 /* if the peer reports AUTH, assume that he
2022 * supports AUTH.
2023 */
2024 if (asoc->ep->auth_enable)
2025 asoc->peer.auth_capable = 1;
2026 break;
2027 case SCTP_CID_ASCONF:
2028 case SCTP_CID_ASCONF_ACK:
2029 if (asoc->ep->asconf_enable)
2030 asoc->peer.asconf_capable = 1;
2031 break;
2032 case SCTP_CID_I_DATA:
2033 if (asoc->ep->intl_enable)
2034 asoc->peer.intl_capable = 1;
2035 break;
2036 default:
2037 break;
2038 }
2039 }
2040 }
2041
2042 /* RFC 3.2.1 & the Implementers Guide 2.2.
2043 *
2044 * The Parameter Types are encoded such that the
2045 * highest-order two bits specify the action that must be
2046 * taken if the processing endpoint does not recognize the
2047 * Parameter Type.
2048 *
2049 * 00 - Stop processing this parameter; do not process any further
2050 * parameters within this chunk
2051 *
2052 * 01 - Stop processing this parameter, do not process any further
2053 * parameters within this chunk, and report the unrecognized
2054 * parameter in an 'Unrecognized Parameter' ERROR chunk.
2055 *
2056 * 10 - Skip this parameter and continue processing.
2057 *
2058 * 11 - Skip this parameter and continue processing but
2059 * report the unrecognized parameter in an
2060 * 'Unrecognized Parameter' ERROR chunk.
2061 *
2062 * Return value:
2063 * SCTP_IERROR_NO_ERROR - continue with the chunk
2064 * SCTP_IERROR_ERROR - stop and report an error.
2065 * SCTP_IERROR_NOMEME - out of memory.
2066 */
2067 static enum sctp_ierror sctp_process_unk_param(
2068 const struct sctp_association *asoc,
2069 union sctp_params param,
2070 struct sctp_chunk *chunk,
2071 struct sctp_chunk **errp)
2072 {
2073 int retval = SCTP_IERROR_NO_ERROR;
2074
2075 switch (param.p->type & SCTP_PARAM_ACTION_MASK) {
2076 case SCTP_PARAM_ACTION_DISCARD:
2077 retval = SCTP_IERROR_ERROR;
2078 break;
2079 case SCTP_PARAM_ACTION_SKIP:
2080 break;
2081 case SCTP_PARAM_ACTION_DISCARD_ERR:
2082 retval = SCTP_IERROR_ERROR;
2083 /* Fall through */
2084 case SCTP_PARAM_ACTION_SKIP_ERR:
2085 /* Make an ERROR chunk, preparing enough room for
2086 * returning multiple unknown parameters.
2087 */
2088 if (!*errp) {
2089 *errp = sctp_make_op_error_limited(asoc, chunk);
2090 if (!*errp) {
2091 /* If there is no memory for generating the
2092 * ERROR report as specified, an ABORT will be
2093 * triggered to the peer and the association
2094 * won't be established.
2095 */
2096 retval = SCTP_IERROR_NOMEM;
2097 break;
2098 }
2099 }
2100
2101 if (!sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM,
2102 ntohs(param.p->length)))
2103 sctp_addto_chunk(*errp, ntohs(param.p->length),
2104 param.v);
2105 break;
2106 default:
2107 break;
2108 }
2109
2110 return retval;
2111 }
2112
2113 /* Verify variable length parameters
2114 * Return values:
2115 * SCTP_IERROR_ABORT - trigger an ABORT
2116 * SCTP_IERROR_NOMEM - out of memory (abort)
2117 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR
2118 * SCTP_IERROR_NO_ERROR - continue with the chunk
2119 */
2120 static enum sctp_ierror sctp_verify_param(struct net *net,
2121 const struct sctp_endpoint *ep,
2122 const struct sctp_association *asoc,
2123 union sctp_params param,
2124 enum sctp_cid cid,
2125 struct sctp_chunk *chunk,
2126 struct sctp_chunk **err_chunk)
2127 {
2128 struct sctp_hmac_algo_param *hmacs;
2129 int retval = SCTP_IERROR_NO_ERROR;
2130 __u16 n_elt, id = 0;
2131 int i;
2132
2133 /* FIXME - This routine is not looking at each parameter per the
2134 * chunk type, i.e., unrecognized parameters should be further
2135 * identified based on the chunk id.
2136 */
2137
2138 switch (param.p->type) {
2139 case SCTP_PARAM_IPV4_ADDRESS:
2140 case SCTP_PARAM_IPV6_ADDRESS:
2141 case SCTP_PARAM_COOKIE_PRESERVATIVE:
2142 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
2143 case SCTP_PARAM_STATE_COOKIE:
2144 case SCTP_PARAM_HEARTBEAT_INFO:
2145 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
2146 case SCTP_PARAM_ECN_CAPABLE:
2147 case SCTP_PARAM_ADAPTATION_LAYER_IND:
2148 break;
2149
2150 case SCTP_PARAM_SUPPORTED_EXT:
2151 if (!sctp_verify_ext_param(net, ep, param))
2152 return SCTP_IERROR_ABORT;
2153 break;
2154
2155 case SCTP_PARAM_SET_PRIMARY:
2156 if (ep->asconf_enable)
2157 break;
2158 goto unhandled;
2159
2160 case SCTP_PARAM_HOST_NAME_ADDRESS:
2161 /* Tell the peer, we won't support this param. */
2162 sctp_process_hn_param(asoc, param, chunk, err_chunk);
2163 retval = SCTP_IERROR_ABORT;
2164 break;
2165
2166 case SCTP_PARAM_FWD_TSN_SUPPORT:
2167 if (ep->prsctp_enable)
2168 break;
2169 goto unhandled;
2170
2171 case SCTP_PARAM_RANDOM:
2172 if (!ep->auth_enable)
2173 goto unhandled;
2174
2175 /* SCTP-AUTH: Secion 6.1
2176 * If the random number is not 32 byte long the association
2177 * MUST be aborted. The ABORT chunk SHOULD contain the error
2178 * cause 'Protocol Violation'.
2179 */
2180 if (SCTP_AUTH_RANDOM_LENGTH != ntohs(param.p->length) -
2181 sizeof(struct sctp_paramhdr)) {
2182 sctp_process_inv_paramlength(asoc, param.p,
2183 chunk, err_chunk);
2184 retval = SCTP_IERROR_ABORT;
2185 }
2186 break;
2187
2188 case SCTP_PARAM_CHUNKS:
2189 if (!ep->auth_enable)
2190 goto unhandled;
2191
2192 /* SCTP-AUTH: Section 3.2
2193 * The CHUNKS parameter MUST be included once in the INIT or
2194 * INIT-ACK chunk if the sender wants to receive authenticated
2195 * chunks. Its maximum length is 260 bytes.
2196 */
2197 if (260 < ntohs(param.p->length)) {
2198 sctp_process_inv_paramlength(asoc, param.p,
2199 chunk, err_chunk);
2200 retval = SCTP_IERROR_ABORT;
2201 }
2202 break;
2203
2204 case SCTP_PARAM_HMAC_ALGO:
2205 if (!ep->auth_enable)
2206 goto unhandled;
2207
2208 hmacs = (struct sctp_hmac_algo_param *)param.p;
2209 n_elt = (ntohs(param.p->length) -
2210 sizeof(struct sctp_paramhdr)) >> 1;
2211
2212 /* SCTP-AUTH: Section 6.1
2213 * The HMAC algorithm based on SHA-1 MUST be supported and
2214 * included in the HMAC-ALGO parameter.
2215 */
2216 for (i = 0; i < n_elt; i++) {
2217 id = ntohs(hmacs->hmac_ids[i]);
2218
2219 if (id == SCTP_AUTH_HMAC_ID_SHA1)
2220 break;
2221 }
2222
2223 if (id != SCTP_AUTH_HMAC_ID_SHA1) {
2224 sctp_process_inv_paramlength(asoc, param.p, chunk,
2225 err_chunk);
2226 retval = SCTP_IERROR_ABORT;
2227 }
2228 break;
2229 unhandled:
2230 default:
2231 pr_debug("%s: unrecognized param:%d for chunk:%d\n",
2232 __func__, ntohs(param.p->type), cid);
2233
2234 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk);
2235 break;
2236 }
2237 return retval;
2238 }
2239
2240 /* Verify the INIT packet before we process it. */
2241 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
2242 const struct sctp_association *asoc, enum sctp_cid cid,
2243 struct sctp_init_chunk *peer_init,
2244 struct sctp_chunk *chunk, struct sctp_chunk **errp)
2245 {
2246 union sctp_params param;
2247 bool has_cookie = false;
2248 int result;
2249
2250 /* Check for missing mandatory parameters. Note: Initial TSN is
2251 * also mandatory, but is not checked here since the valid range
2252 * is 0..2**32-1. RFC4960, section 3.3.3.
2253 */
2254 if (peer_init->init_hdr.num_outbound_streams == 0 ||
2255 peer_init->init_hdr.num_inbound_streams == 0 ||
2256 peer_init->init_hdr.init_tag == 0 ||
2257 ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW)
2258 return sctp_process_inv_mandatory(asoc, chunk, errp);
2259
2260 sctp_walk_params(param, peer_init, init_hdr.params) {
2261 if (param.p->type == SCTP_PARAM_STATE_COOKIE)
2262 has_cookie = true;
2263 }
2264
2265 /* There is a possibility that a parameter length was bad and
2266 * in that case we would have stoped walking the parameters.
2267 * The current param.p would point at the bad one.
2268 * Current consensus on the mailing list is to generate a PROTOCOL
2269 * VIOLATION error. We build the ERROR chunk here and let the normal
2270 * error handling code build and send the packet.
2271 */
2272 if (param.v != (void *)chunk->chunk_end)
2273 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp);
2274
2275 /* The only missing mandatory param possible today is
2276 * the state cookie for an INIT-ACK chunk.
2277 */
2278 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie)
2279 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE,
2280 chunk, errp);
2281
2282 /* Verify all the variable length parameters */
2283 sctp_walk_params(param, peer_init, init_hdr.params) {
2284 result = sctp_verify_param(net, ep, asoc, param, cid,
2285 chunk, errp);
2286 switch (result) {
2287 case SCTP_IERROR_ABORT:
2288 case SCTP_IERROR_NOMEM:
2289 return 0;
2290 case SCTP_IERROR_ERROR:
2291 return 1;
2292 case SCTP_IERROR_NO_ERROR:
2293 default:
2294 break;
2295 }
2296
2297 } /* for (loop through all parameters) */
2298
2299 return 1;
2300 }
2301
2302 /* Unpack the parameters in an INIT packet into an association.
2303 * Returns 0 on failure, else success.
2304 * FIXME: This is an association method.
2305 */
2306 int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk,
2307 const union sctp_addr *peer_addr,
2308 struct sctp_init_chunk *peer_init, gfp_t gfp)
2309 {
2310 struct sctp_transport *transport;
2311 struct list_head *pos, *temp;
2312 union sctp_params param;
2313 union sctp_addr addr;
2314 struct sctp_af *af;
2315 int src_match = 0;
2316
2317 /* We must include the address that the INIT packet came from.
2318 * This is the only address that matters for an INIT packet.
2319 * When processing a COOKIE ECHO, we retrieve the from address
2320 * of the INIT from the cookie.
2321 */
2322
2323 /* This implementation defaults to making the first transport
2324 * added as the primary transport. The source address seems to
2325 * be a a better choice than any of the embedded addresses.
2326 */
2327 if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE))
2328 goto nomem;
2329
2330 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr))
2331 src_match = 1;
2332
2333 /* Process the initialization parameters. */
2334 sctp_walk_params(param, peer_init, init_hdr.params) {
2335 if (!src_match && (param.p->type == SCTP_PARAM_IPV4_ADDRESS ||
2336 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) {
2337 af = sctp_get_af_specific(param_type2af(param.p->type));
2338 af->from_addr_param(&addr, param.addr,
2339 chunk->sctp_hdr->source, 0);
2340 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr))
2341 src_match = 1;
2342 }
2343
2344 if (!sctp_process_param(asoc, param, peer_addr, gfp))
2345 goto clean_up;
2346 }
2347
2348 /* source address of chunk may not match any valid address */
2349 if (!src_match)
2350 goto clean_up;
2351
2352 /* AUTH: After processing the parameters, make sure that we
2353 * have all the required info to potentially do authentications.
2354 */
2355 if (asoc->peer.auth_capable && (!asoc->peer.peer_random ||
2356 !asoc->peer.peer_hmacs))
2357 asoc->peer.auth_capable = 0;
2358
2359 /* In a non-backward compatible mode, if the peer claims
2360 * support for ADD-IP but not AUTH, the ADD-IP spec states
2361 * that we MUST ABORT the association. Section 6. The section
2362 * also give us an option to silently ignore the packet, which
2363 * is what we'll do here.
2364 */
2365 if (!asoc->base.net->sctp.addip_noauth &&
2366 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) {
2367 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP |
2368 SCTP_PARAM_DEL_IP |
2369 SCTP_PARAM_SET_PRIMARY);
2370 asoc->peer.asconf_capable = 0;
2371 goto clean_up;
2372 }
2373
2374 /* Walk list of transports, removing transports in the UNKNOWN state. */
2375 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
2376 transport = list_entry(pos, struct sctp_transport, transports);
2377 if (transport->state == SCTP_UNKNOWN) {
2378 sctp_assoc_rm_peer(asoc, transport);
2379 }
2380 }
2381
2382 /* The fixed INIT headers are always in network byte
2383 * order.
2384 */
2385 asoc->peer.i.init_tag =
2386 ntohl(peer_init->init_hdr.init_tag);
2387 asoc->peer.i.a_rwnd =
2388 ntohl(peer_init->init_hdr.a_rwnd);
2389 asoc->peer.i.num_outbound_streams =
2390 ntohs(peer_init->init_hdr.num_outbound_streams);
2391 asoc->peer.i.num_inbound_streams =
2392 ntohs(peer_init->init_hdr.num_inbound_streams);
2393 asoc->peer.i.initial_tsn =
2394 ntohl(peer_init->init_hdr.initial_tsn);
2395
2396 asoc->strreset_inseq = asoc->peer.i.initial_tsn;
2397
2398 /* Apply the upper bounds for output streams based on peer's
2399 * number of inbound streams.
2400 */
2401 if (asoc->c.sinit_num_ostreams >
2402 ntohs(peer_init->init_hdr.num_inbound_streams)) {
2403 asoc->c.sinit_num_ostreams =
2404 ntohs(peer_init->init_hdr.num_inbound_streams);
2405 }
2406
2407 if (asoc->c.sinit_max_instreams >
2408 ntohs(peer_init->init_hdr.num_outbound_streams)) {
2409 asoc->c.sinit_max_instreams =
2410 ntohs(peer_init->init_hdr.num_outbound_streams);
2411 }
2412
2413 /* Copy Initiation tag from INIT to VT_peer in cookie. */
2414 asoc->c.peer_vtag = asoc->peer.i.init_tag;
2415
2416 /* Peer Rwnd : Current calculated value of the peer's rwnd. */
2417 asoc->peer.rwnd = asoc->peer.i.a_rwnd;
2418
2419 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily
2420 * high (for example, implementations MAY use the size of the receiver
2421 * advertised window).
2422 */
2423 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
2424 transports) {
2425 transport->ssthresh = asoc->peer.i.a_rwnd;
2426 }
2427
2428 /* Set up the TSN tracking pieces. */
2429 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
2430 asoc->peer.i.initial_tsn, gfp))
2431 goto clean_up;
2432
2433 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
2434 *
2435 * The stream sequence number in all the streams shall start
2436 * from 0 when the association is established. Also, when the
2437 * stream sequence number reaches the value 65535 the next
2438 * stream sequence number shall be set to 0.
2439 */
2440
2441 if (sctp_stream_init(&asoc->stream, asoc->c.sinit_num_ostreams,
2442 asoc->c.sinit_max_instreams, gfp))
2443 goto clean_up;
2444
2445 /* Update frag_point when stream_interleave may get changed. */
2446 sctp_assoc_update_frag_point(asoc);
2447
2448 if (!asoc->temp && sctp_assoc_set_id(asoc, gfp))
2449 goto clean_up;
2450
2451 /* ADDIP Section 4.1 ASCONF Chunk Procedures
2452 *
2453 * When an endpoint has an ASCONF signaled change to be sent to the
2454 * remote endpoint it should do the following:
2455 * ...
2456 * A2) A serial number should be assigned to the Chunk. The serial
2457 * number should be a monotonically increasing number. All serial
2458 * numbers are defined to be initialized at the start of the
2459 * association to the same value as the Initial TSN.
2460 */
2461 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1;
2462 return 1;
2463
2464 clean_up:
2465 /* Release the transport structures. */
2466 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
2467 transport = list_entry(pos, struct sctp_transport, transports);
2468 if (transport->state != SCTP_ACTIVE)
2469 sctp_assoc_rm_peer(asoc, transport);
2470 }
2471
2472 nomem:
2473 return 0;
2474 }
2475
2476
2477 /* Update asoc with the option described in param.
2478 *
2479 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT
2480 *
2481 * asoc is the association to update.
2482 * param is the variable length parameter to use for update.
2483 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO.
2484 * If the current packet is an INIT we want to minimize the amount of
2485 * work we do. In particular, we should not build transport
2486 * structures for the addresses.
2487 */
2488 static int sctp_process_param(struct sctp_association *asoc,
2489 union sctp_params param,
2490 const union sctp_addr *peer_addr,
2491 gfp_t gfp)
2492 {
2493 struct sctp_endpoint *ep = asoc->ep;
2494 union sctp_addr_param *addr_param;
2495 struct net *net = asoc->base.net;
2496 struct sctp_transport *t;
2497 enum sctp_scope scope;
2498 union sctp_addr addr;
2499 struct sctp_af *af;
2500 int retval = 1, i;
2501 u32 stale;
2502 __u16 sat;
2503
2504 /* We maintain all INIT parameters in network byte order all the
2505 * time. This allows us to not worry about whether the parameters
2506 * came from a fresh INIT, and INIT ACK, or were stored in a cookie.
2507 */
2508 switch (param.p->type) {
2509 case SCTP_PARAM_IPV6_ADDRESS:
2510 if (PF_INET6 != asoc->base.sk->sk_family)
2511 break;
2512 goto do_addr_param;
2513
2514 case SCTP_PARAM_IPV4_ADDRESS:
2515 /* v4 addresses are not allowed on v6-only socket */
2516 if (ipv6_only_sock(asoc->base.sk))
2517 break;
2518 do_addr_param:
2519 af = sctp_get_af_specific(param_type2af(param.p->type));
2520 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0);
2521 scope = sctp_scope(peer_addr);
2522 if (sctp_in_scope(net, &addr, scope))
2523 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED))
2524 return 0;
2525 break;
2526
2527 case SCTP_PARAM_COOKIE_PRESERVATIVE:
2528 if (!net->sctp.cookie_preserve_enable)
2529 break;
2530
2531 stale = ntohl(param.life->lifespan_increment);
2532
2533 /* Suggested Cookie Life span increment's unit is msec,
2534 * (1/1000sec).
2535 */
2536 asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale);
2537 break;
2538
2539 case SCTP_PARAM_HOST_NAME_ADDRESS:
2540 pr_debug("%s: unimplemented SCTP_HOST_NAME_ADDRESS\n", __func__);
2541 break;
2542
2543 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
2544 /* Turn off the default values first so we'll know which
2545 * ones are really set by the peer.
2546 */
2547 asoc->peer.ipv4_address = 0;
2548 asoc->peer.ipv6_address = 0;
2549
2550 /* Assume that peer supports the address family
2551 * by which it sends a packet.
2552 */
2553 if (peer_addr->sa.sa_family == AF_INET6)
2554 asoc->peer.ipv6_address = 1;
2555 else if (peer_addr->sa.sa_family == AF_INET)
2556 asoc->peer.ipv4_address = 1;
2557
2558 /* Cycle through address types; avoid divide by 0. */
2559 sat = ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
2560 if (sat)
2561 sat /= sizeof(__u16);
2562
2563 for (i = 0; i < sat; ++i) {
2564 switch (param.sat->types[i]) {
2565 case SCTP_PARAM_IPV4_ADDRESS:
2566 asoc->peer.ipv4_address = 1;
2567 break;
2568
2569 case SCTP_PARAM_IPV6_ADDRESS:
2570 if (PF_INET6 == asoc->base.sk->sk_family)
2571 asoc->peer.ipv6_address = 1;
2572 break;
2573
2574 case SCTP_PARAM_HOST_NAME_ADDRESS:
2575 asoc->peer.hostname_address = 1;
2576 break;
2577
2578 default: /* Just ignore anything else. */
2579 break;
2580 }
2581 }
2582 break;
2583
2584 case SCTP_PARAM_STATE_COOKIE:
2585 asoc->peer.cookie_len =
2586 ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
2587 kfree(asoc->peer.cookie);
2588 asoc->peer.cookie = kmemdup(param.cookie->body, asoc->peer.cookie_len, gfp);
2589 if (!asoc->peer.cookie)
2590 retval = 0;
2591 break;
2592
2593 case SCTP_PARAM_HEARTBEAT_INFO:
2594 /* Would be odd to receive, but it causes no problems. */
2595 break;
2596
2597 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
2598 /* Rejected during verify stage. */
2599 break;
2600
2601 case SCTP_PARAM_ECN_CAPABLE:
2602 if (asoc->ep->ecn_enable) {
2603 asoc->peer.ecn_capable = 1;
2604 break;
2605 }
2606 /* Fall Through */
2607 goto fall_through;
2608
2609
2610 case SCTP_PARAM_ADAPTATION_LAYER_IND:
2611 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind);
2612 break;
2613
2614 case SCTP_PARAM_SET_PRIMARY:
2615 if (!ep->asconf_enable)
2616 goto fall_through;
2617
2618 addr_param = param.v + sizeof(struct sctp_addip_param);
2619
2620 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
2621 if (af == NULL)
2622 break;
2623
2624 af->from_addr_param(&addr, addr_param,
2625 htons(asoc->peer.port), 0);
2626
2627 /* if the address is invalid, we can't process it.
2628 * XXX: see spec for what to do.
2629 */
2630 if (!af->addr_valid(&addr, NULL, NULL))
2631 break;
2632
2633 t = sctp_assoc_lookup_paddr(asoc, &addr);
2634 if (!t)
2635 break;
2636
2637 sctp_assoc_set_primary(asoc, t);
2638 break;
2639
2640 case SCTP_PARAM_SUPPORTED_EXT:
2641 sctp_process_ext_param(asoc, param);
2642 break;
2643
2644 case SCTP_PARAM_FWD_TSN_SUPPORT:
2645 if (asoc->ep->prsctp_enable) {
2646 asoc->peer.prsctp_capable = 1;
2647 break;
2648 }
2649 /* Fall Through */
2650 goto fall_through;
2651
2652 case SCTP_PARAM_RANDOM:
2653 if (!ep->auth_enable)
2654 goto fall_through;
2655
2656 /* Save peer's random parameter */
2657 kfree(asoc->peer.peer_random);
2658 asoc->peer.peer_random = kmemdup(param.p,
2659 ntohs(param.p->length), gfp);
2660 if (!asoc->peer.peer_random) {
2661 retval = 0;
2662 break;
2663 }
2664 break;
2665
2666 case SCTP_PARAM_HMAC_ALGO:
2667 if (!ep->auth_enable)
2668 goto fall_through;
2669
2670 /* Save peer's HMAC list */
2671 kfree(asoc->peer.peer_hmacs);
2672 asoc->peer.peer_hmacs = kmemdup(param.p,
2673 ntohs(param.p->length), gfp);
2674 if (!asoc->peer.peer_hmacs) {
2675 retval = 0;
2676 break;
2677 }
2678
2679 /* Set the default HMAC the peer requested*/
2680 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo);
2681 break;
2682
2683 case SCTP_PARAM_CHUNKS:
2684 if (!ep->auth_enable)
2685 goto fall_through;
2686
2687 kfree(asoc->peer.peer_chunks);
2688 asoc->peer.peer_chunks = kmemdup(param.p,
2689 ntohs(param.p->length), gfp);
2690 if (!asoc->peer.peer_chunks)
2691 retval = 0;
2692 break;
2693 fall_through:
2694 default:
2695 /* Any unrecognized parameters should have been caught
2696 * and handled by sctp_verify_param() which should be
2697 * called prior to this routine. Simply log the error
2698 * here.
2699 */
2700 pr_debug("%s: ignoring param:%d for association:%p.\n",
2701 __func__, ntohs(param.p->type), asoc);
2702 break;
2703 }
2704
2705 return retval;
2706 }
2707
2708 /* Select a new verification tag. */
2709 __u32 sctp_generate_tag(const struct sctp_endpoint *ep)
2710 {
2711 /* I believe that this random number generator complies with RFC1750.
2712 * A tag of 0 is reserved for special cases (e.g. INIT).
2713 */
2714 __u32 x;
2715
2716 do {
2717 get_random_bytes(&x, sizeof(__u32));
2718 } while (x == 0);
2719
2720 return x;
2721 }
2722
2723 /* Select an initial TSN to send during startup. */
2724 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep)
2725 {
2726 __u32 retval;
2727
2728 get_random_bytes(&retval, sizeof(__u32));
2729 return retval;
2730 }
2731
2732 /*
2733 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF)
2734 * 0 1 2 3
2735 * 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
2736 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2737 * | Type = 0xC1 | Chunk Flags | Chunk Length |
2738 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2739 * | Serial Number |
2740 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2741 * | Address Parameter |
2742 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2743 * | ASCONF Parameter #1 |
2744 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2745 * \ \
2746 * / .... /
2747 * \ \
2748 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2749 * | ASCONF Parameter #N |
2750 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2751 *
2752 * Address Parameter and other parameter will not be wrapped in this function
2753 */
2754 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc,
2755 union sctp_addr *addr,
2756 int vparam_len)
2757 {
2758 struct sctp_addiphdr asconf;
2759 struct sctp_chunk *retval;
2760 int length = sizeof(asconf) + vparam_len;
2761 union sctp_addr_param addrparam;
2762 int addrlen;
2763 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
2764
2765 addrlen = af->to_addr_param(addr, &addrparam);
2766 if (!addrlen)
2767 return NULL;
2768 length += addrlen;
2769
2770 /* Create the chunk. */
2771 retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length,
2772 GFP_ATOMIC);
2773 if (!retval)
2774 return NULL;
2775
2776 asconf.serial = htonl(asoc->addip_serial++);
2777
2778 retval->subh.addip_hdr =
2779 sctp_addto_chunk(retval, sizeof(asconf), &asconf);
2780 retval->param_hdr.v =
2781 sctp_addto_chunk(retval, addrlen, &addrparam);
2782
2783 return retval;
2784 }
2785
2786 /* ADDIP
2787 * 3.2.1 Add IP Address
2788 * 0 1 2 3
2789 * 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
2790 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2791 * | Type = 0xC001 | Length = Variable |
2792 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2793 * | ASCONF-Request Correlation ID |
2794 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2795 * | Address Parameter |
2796 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2797 *
2798 * 3.2.2 Delete IP Address
2799 * 0 1 2 3
2800 * 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
2801 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2802 * | Type = 0xC002 | Length = Variable |
2803 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2804 * | ASCONF-Request Correlation ID |
2805 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2806 * | Address Parameter |
2807 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2808 *
2809 */
2810 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc,
2811 union sctp_addr *laddr,
2812 struct sockaddr *addrs,
2813 int addrcnt, __be16 flags)
2814 {
2815 union sctp_addr_param addr_param;
2816 struct sctp_addip_param param;
2817 int paramlen = sizeof(param);
2818 struct sctp_chunk *retval;
2819 int addr_param_len = 0;
2820 union sctp_addr *addr;
2821 int totallen = 0, i;
2822 int del_pickup = 0;
2823 struct sctp_af *af;
2824 void *addr_buf;
2825
2826 /* Get total length of all the address parameters. */
2827 addr_buf = addrs;
2828 for (i = 0; i < addrcnt; i++) {
2829 addr = addr_buf;
2830 af = sctp_get_af_specific(addr->v4.sin_family);
2831 addr_param_len = af->to_addr_param(addr, &addr_param);
2832
2833 totallen += paramlen;
2834 totallen += addr_param_len;
2835
2836 addr_buf += af->sockaddr_len;
2837 if (asoc->asconf_addr_del_pending && !del_pickup) {
2838 /* reuse the parameter length from the same scope one */
2839 totallen += paramlen;
2840 totallen += addr_param_len;
2841 del_pickup = 1;
2842
2843 pr_debug("%s: picked same-scope del_pending addr, "
2844 "totallen for all addresses is %d\n",
2845 __func__, totallen);
2846 }
2847 }
2848
2849 /* Create an asconf chunk with the required length. */
2850 retval = sctp_make_asconf(asoc, laddr, totallen);
2851 if (!retval)
2852 return NULL;
2853
2854 /* Add the address parameters to the asconf chunk. */
2855 addr_buf = addrs;
2856 for (i = 0; i < addrcnt; i++) {
2857 addr = addr_buf;
2858 af = sctp_get_af_specific(addr->v4.sin_family);
2859 addr_param_len = af->to_addr_param(addr, &addr_param);
2860 param.param_hdr.type = flags;
2861 param.param_hdr.length = htons(paramlen + addr_param_len);
2862 param.crr_id = htonl(i);
2863
2864 sctp_addto_chunk(retval, paramlen, &param);
2865 sctp_addto_chunk(retval, addr_param_len, &addr_param);
2866
2867 addr_buf += af->sockaddr_len;
2868 }
2869 if (flags == SCTP_PARAM_ADD_IP && del_pickup) {
2870 addr = asoc->asconf_addr_del_pending;
2871 af = sctp_get_af_specific(addr->v4.sin_family);
2872 addr_param_len = af->to_addr_param(addr, &addr_param);
2873 param.param_hdr.type = SCTP_PARAM_DEL_IP;
2874 param.param_hdr.length = htons(paramlen + addr_param_len);
2875 param.crr_id = htonl(i);
2876
2877 sctp_addto_chunk(retval, paramlen, &param);
2878 sctp_addto_chunk(retval, addr_param_len, &addr_param);
2879 }
2880 return retval;
2881 }
2882
2883 /* ADDIP
2884 * 3.2.4 Set Primary IP Address
2885 * 0 1 2 3
2886 * 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
2887 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2888 * | Type =0xC004 | Length = Variable |
2889 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2890 * | ASCONF-Request Correlation ID |
2891 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2892 * | Address Parameter |
2893 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2894 *
2895 * Create an ASCONF chunk with Set Primary IP address parameter.
2896 */
2897 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
2898 union sctp_addr *addr)
2899 {
2900 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
2901 union sctp_addr_param addrparam;
2902 struct sctp_addip_param param;
2903 struct sctp_chunk *retval;
2904 int len = sizeof(param);
2905 int addrlen;
2906
2907 addrlen = af->to_addr_param(addr, &addrparam);
2908 if (!addrlen)
2909 return NULL;
2910 len += addrlen;
2911
2912 /* Create the chunk and make asconf header. */
2913 retval = sctp_make_asconf(asoc, addr, len);
2914 if (!retval)
2915 return NULL;
2916
2917 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY;
2918 param.param_hdr.length = htons(len);
2919 param.crr_id = 0;
2920
2921 sctp_addto_chunk(retval, sizeof(param), &param);
2922 sctp_addto_chunk(retval, addrlen, &addrparam);
2923
2924 return retval;
2925 }
2926
2927 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK)
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 = 0x80 | Chunk Flags | Chunk Length |
2932 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2933 * | Serial Number |
2934 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2935 * | ASCONF Parameter Response#1 |
2936 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2937 * \ \
2938 * / .... /
2939 * \ \
2940 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2941 * | ASCONF Parameter Response#N |
2942 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2943 *
2944 * Create an ASCONF_ACK chunk with enough space for the parameter responses.
2945 */
2946 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc,
2947 __u32 serial, int vparam_len)
2948 {
2949 struct sctp_addiphdr asconf;
2950 struct sctp_chunk *retval;
2951 int length = sizeof(asconf) + vparam_len;
2952
2953 /* Create the chunk. */
2954 retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length,
2955 GFP_ATOMIC);
2956 if (!retval)
2957 return NULL;
2958
2959 asconf.serial = htonl(serial);
2960
2961 retval->subh.addip_hdr =
2962 sctp_addto_chunk(retval, sizeof(asconf), &asconf);
2963
2964 return retval;
2965 }
2966
2967 /* Add response parameters to an ASCONF_ACK chunk. */
2968 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id,
2969 __be16 err_code,
2970 struct sctp_addip_param *asconf_param)
2971 {
2972 struct sctp_addip_param ack_param;
2973 struct sctp_errhdr err_param;
2974 int asconf_param_len = 0;
2975 int err_param_len = 0;
2976 __be16 response_type;
2977
2978 if (SCTP_ERROR_NO_ERROR == err_code) {
2979 response_type = SCTP_PARAM_SUCCESS_REPORT;
2980 } else {
2981 response_type = SCTP_PARAM_ERR_CAUSE;
2982 err_param_len = sizeof(err_param);
2983 if (asconf_param)
2984 asconf_param_len =
2985 ntohs(asconf_param->param_hdr.length);
2986 }
2987
2988 /* Add Success Indication or Error Cause Indication parameter. */
2989 ack_param.param_hdr.type = response_type;
2990 ack_param.param_hdr.length = htons(sizeof(ack_param) +
2991 err_param_len +
2992 asconf_param_len);
2993 ack_param.crr_id = crr_id;
2994 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param);
2995
2996 if (SCTP_ERROR_NO_ERROR == err_code)
2997 return;
2998
2999 /* Add Error Cause parameter. */
3000 err_param.cause = err_code;
3001 err_param.length = htons(err_param_len + asconf_param_len);
3002 sctp_addto_chunk(chunk, err_param_len, &err_param);
3003
3004 /* Add the failed TLV copied from ASCONF chunk. */
3005 if (asconf_param)
3006 sctp_addto_chunk(chunk, asconf_param_len, asconf_param);
3007 }
3008
3009 /* Process a asconf parameter. */
3010 static __be16 sctp_process_asconf_param(struct sctp_association *asoc,
3011 struct sctp_chunk *asconf,
3012 struct sctp_addip_param *asconf_param)
3013 {
3014 union sctp_addr_param *addr_param;
3015 struct sctp_transport *peer;
3016 union sctp_addr addr;
3017 struct sctp_af *af;
3018
3019 addr_param = (void *)asconf_param + sizeof(*asconf_param);
3020
3021 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP &&
3022 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP &&
3023 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY)
3024 return SCTP_ERROR_UNKNOWN_PARAM;
3025
3026 switch (addr_param->p.type) {
3027 case SCTP_PARAM_IPV6_ADDRESS:
3028 if (!asoc->peer.ipv6_address)
3029 return SCTP_ERROR_DNS_FAILED;
3030 break;
3031 case SCTP_PARAM_IPV4_ADDRESS:
3032 if (!asoc->peer.ipv4_address)
3033 return SCTP_ERROR_DNS_FAILED;
3034 break;
3035 default:
3036 return SCTP_ERROR_DNS_FAILED;
3037 }
3038
3039 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
3040 if (unlikely(!af))
3041 return SCTP_ERROR_DNS_FAILED;
3042
3043 af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0);
3044
3045 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast
3046 * or multicast address.
3047 * (note: wildcard is permitted and requires special handling so
3048 * make sure we check for that)
3049 */
3050 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb))
3051 return SCTP_ERROR_DNS_FAILED;
3052
3053 switch (asconf_param->param_hdr.type) {
3054 case SCTP_PARAM_ADD_IP:
3055 /* Section 4.2.1:
3056 * If the address 0.0.0.0 or ::0 is provided, the source
3057 * address of the packet MUST be added.
3058 */
3059 if (af->is_any(&addr))
3060 memcpy(&addr, &asconf->source, sizeof(addr));
3061
3062 if (security_sctp_bind_connect(asoc->ep->base.sk,
3063 SCTP_PARAM_ADD_IP,
3064 (struct sockaddr *)&addr,
3065 af->sockaddr_len))
3066 return SCTP_ERROR_REQ_REFUSED;
3067
3068 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address
3069 * request and does not have the local resources to add this
3070 * new address to the association, it MUST return an Error
3071 * Cause TLV set to the new error code 'Operation Refused
3072 * Due to Resource Shortage'.
3073 */
3074
3075 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED);
3076 if (!peer)
3077 return SCTP_ERROR_RSRC_LOW;
3078
3079 /* Start the heartbeat timer. */
3080 sctp_transport_reset_hb_timer(peer);
3081 asoc->new_transport = peer;
3082 break;
3083 case SCTP_PARAM_DEL_IP:
3084 /* ADDIP 4.3 D7) If a request is received to delete the
3085 * last remaining IP address of a peer endpoint, the receiver
3086 * MUST send an Error Cause TLV with the error cause set to the
3087 * new error code 'Request to Delete Last Remaining IP Address'.
3088 */
3089 if (asoc->peer.transport_count == 1)
3090 return SCTP_ERROR_DEL_LAST_IP;
3091
3092 /* ADDIP 4.3 D8) If a request is received to delete an IP
3093 * address which is also the source address of the IP packet
3094 * which contained the ASCONF chunk, the receiver MUST reject
3095 * this request. To reject the request the receiver MUST send
3096 * an Error Cause TLV set to the new error code 'Request to
3097 * Delete Source IP Address'
3098 */
3099 if (sctp_cmp_addr_exact(&asconf->source, &addr))
3100 return SCTP_ERROR_DEL_SRC_IP;
3101
3102 /* Section 4.2.2
3103 * If the address 0.0.0.0 or ::0 is provided, all
3104 * addresses of the peer except the source address of the
3105 * packet MUST be deleted.
3106 */
3107 if (af->is_any(&addr)) {
3108 sctp_assoc_set_primary(asoc, asconf->transport);
3109 sctp_assoc_del_nonprimary_peers(asoc,
3110 asconf->transport);
3111 return SCTP_ERROR_NO_ERROR;
3112 }
3113
3114 /* If the address is not part of the association, the
3115 * ASCONF-ACK with Error Cause Indication Parameter
3116 * which including cause of Unresolvable Address should
3117 * be sent.
3118 */
3119 peer = sctp_assoc_lookup_paddr(asoc, &addr);
3120 if (!peer)
3121 return SCTP_ERROR_DNS_FAILED;
3122
3123 sctp_assoc_rm_peer(asoc, peer);
3124 break;
3125 case SCTP_PARAM_SET_PRIMARY:
3126 /* ADDIP Section 4.2.4
3127 * If the address 0.0.0.0 or ::0 is provided, the receiver
3128 * MAY mark the source address of the packet as its
3129 * primary.
3130 */
3131 if (af->is_any(&addr))
3132 memcpy(&addr.v4, sctp_source(asconf), sizeof(addr));
3133
3134 if (security_sctp_bind_connect(asoc->ep->base.sk,
3135 SCTP_PARAM_SET_PRIMARY,
3136 (struct sockaddr *)&addr,
3137 af->sockaddr_len))
3138 return SCTP_ERROR_REQ_REFUSED;
3139
3140 peer = sctp_assoc_lookup_paddr(asoc, &addr);
3141 if (!peer)
3142 return SCTP_ERROR_DNS_FAILED;
3143
3144 sctp_assoc_set_primary(asoc, peer);
3145 break;
3146 }
3147
3148 return SCTP_ERROR_NO_ERROR;
3149 }
3150
3151 /* Verify the ASCONF packet before we process it. */
3152 bool sctp_verify_asconf(const struct sctp_association *asoc,
3153 struct sctp_chunk *chunk, bool addr_param_needed,
3154 struct sctp_paramhdr **errp)
3155 {
3156 struct sctp_addip_chunk *addip;
3157 bool addr_param_seen = false;
3158 union sctp_params param;
3159
3160 addip = (struct sctp_addip_chunk *)chunk->chunk_hdr;
3161 sctp_walk_params(param, addip, addip_hdr.params) {
3162 size_t length = ntohs(param.p->length);
3163
3164 *errp = param.p;
3165 switch (param.p->type) {
3166 case SCTP_PARAM_ERR_CAUSE:
3167 break;
3168 case SCTP_PARAM_IPV4_ADDRESS:
3169 if (length != sizeof(struct sctp_ipv4addr_param))
3170 return false;
3171 /* ensure there is only one addr param and it's in the
3172 * beginning of addip_hdr params, or we reject it.
3173 */
3174 if (param.v != addip->addip_hdr.params)
3175 return false;
3176 addr_param_seen = true;
3177 break;
3178 case SCTP_PARAM_IPV6_ADDRESS:
3179 if (length != sizeof(struct sctp_ipv6addr_param))
3180 return false;
3181 if (param.v != addip->addip_hdr.params)
3182 return false;
3183 addr_param_seen = true;
3184 break;
3185 case SCTP_PARAM_ADD_IP:
3186 case SCTP_PARAM_DEL_IP:
3187 case SCTP_PARAM_SET_PRIMARY:
3188 /* In ASCONF chunks, these need to be first. */
3189 if (addr_param_needed && !addr_param_seen)
3190 return false;
3191 length = ntohs(param.addip->param_hdr.length);
3192 if (length < sizeof(struct sctp_addip_param) +
3193 sizeof(**errp))
3194 return false;
3195 break;
3196 case SCTP_PARAM_SUCCESS_REPORT:
3197 case SCTP_PARAM_ADAPTATION_LAYER_IND:
3198 if (length != sizeof(struct sctp_addip_param))
3199 return false;
3200 break;
3201 default:
3202 /* This is unkown to us, reject! */
3203 return false;
3204 }
3205 }
3206
3207 /* Remaining sanity checks. */
3208 if (addr_param_needed && !addr_param_seen)
3209 return false;
3210 if (!addr_param_needed && addr_param_seen)
3211 return false;
3212 if (param.v != chunk->chunk_end)
3213 return false;
3214
3215 return true;
3216 }
3217
3218 /* Process an incoming ASCONF chunk with the next expected serial no. and
3219 * return an ASCONF_ACK chunk to be sent in response.
3220 */
3221 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
3222 struct sctp_chunk *asconf)
3223 {
3224 union sctp_addr_param *addr_param;
3225 struct sctp_addip_chunk *addip;
3226 struct sctp_chunk *asconf_ack;
3227 bool all_param_pass = true;
3228 struct sctp_addiphdr *hdr;
3229 int length = 0, chunk_len;
3230 union sctp_params param;
3231 __be16 err_code;
3232 __u32 serial;
3233
3234 addip = (struct sctp_addip_chunk *)asconf->chunk_hdr;
3235 chunk_len = ntohs(asconf->chunk_hdr->length) -
3236 sizeof(struct sctp_chunkhdr);
3237 hdr = (struct sctp_addiphdr *)asconf->skb->data;
3238 serial = ntohl(hdr->serial);
3239
3240 /* Skip the addiphdr and store a pointer to address parameter. */
3241 length = sizeof(*hdr);
3242 addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
3243 chunk_len -= length;
3244
3245 /* Skip the address parameter and store a pointer to the first
3246 * asconf parameter.
3247 */
3248 length = ntohs(addr_param->p.length);
3249 chunk_len -= length;
3250
3251 /* create an ASCONF_ACK chunk.
3252 * Based on the definitions of parameters, we know that the size of
3253 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF
3254 * parameters.
3255 */
3256 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4);
3257 if (!asconf_ack)
3258 goto done;
3259
3260 /* Process the TLVs contained within the ASCONF chunk. */
3261 sctp_walk_params(param, addip, addip_hdr.params) {
3262 /* Skip preceeding address parameters. */
3263 if (param.p->type == SCTP_PARAM_IPV4_ADDRESS ||
3264 param.p->type == SCTP_PARAM_IPV6_ADDRESS)
3265 continue;
3266
3267 err_code = sctp_process_asconf_param(asoc, asconf,
3268 param.addip);
3269 /* ADDIP 4.1 A7)
3270 * If an error response is received for a TLV parameter,
3271 * all TLVs with no response before the failed TLV are
3272 * considered successful if not reported. All TLVs after
3273 * the failed response are considered unsuccessful unless
3274 * a specific success indication is present for the parameter.
3275 */
3276 if (err_code != SCTP_ERROR_NO_ERROR)
3277 all_param_pass = false;
3278 if (!all_param_pass)
3279 sctp_add_asconf_response(asconf_ack, param.addip->crr_id,
3280 err_code, param.addip);
3281
3282 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add
3283 * an IP address sends an 'Out of Resource' in its response, it
3284 * MUST also fail any subsequent add or delete requests bundled
3285 * in the ASCONF.
3286 */
3287 if (err_code == SCTP_ERROR_RSRC_LOW)
3288 goto done;
3289 }
3290 done:
3291 asoc->peer.addip_serial++;
3292
3293 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc
3294 * after freeing the reference to old asconf ack if any.
3295 */
3296 if (asconf_ack) {
3297 sctp_chunk_hold(asconf_ack);
3298 list_add_tail(&asconf_ack->transmitted_list,
3299 &asoc->asconf_ack_list);
3300 }
3301
3302 return asconf_ack;
3303 }
3304
3305 /* Process a asconf parameter that is successfully acked. */
3306 static void sctp_asconf_param_success(struct sctp_association *asoc,
3307 struct sctp_addip_param *asconf_param)
3308 {
3309 struct sctp_bind_addr *bp = &asoc->base.bind_addr;
3310 union sctp_addr_param *addr_param;
3311 struct sctp_sockaddr_entry *saddr;
3312 struct sctp_transport *transport;
3313 union sctp_addr addr;
3314 struct sctp_af *af;
3315
3316 addr_param = (void *)asconf_param + sizeof(*asconf_param);
3317
3318 /* We have checked the packet before, so we do not check again. */
3319 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
3320 af->from_addr_param(&addr, addr_param, htons(bp->port), 0);
3321
3322 switch (asconf_param->param_hdr.type) {
3323 case SCTP_PARAM_ADD_IP:
3324 /* This is always done in BH context with a socket lock
3325 * held, so the list can not change.
3326 */
3327 local_bh_disable();
3328 list_for_each_entry(saddr, &bp->address_list, list) {
3329 if (sctp_cmp_addr_exact(&saddr->a, &addr))
3330 saddr->state = SCTP_ADDR_SRC;
3331 }
3332 local_bh_enable();
3333 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
3334 transports) {
3335 sctp_transport_dst_release(transport);
3336 }
3337 break;
3338 case SCTP_PARAM_DEL_IP:
3339 local_bh_disable();
3340 sctp_del_bind_addr(bp, &addr);
3341 if (asoc->asconf_addr_del_pending != NULL &&
3342 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) {
3343 kfree(asoc->asconf_addr_del_pending);
3344 asoc->asconf_addr_del_pending = NULL;
3345 }
3346 local_bh_enable();
3347 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
3348 transports) {
3349 sctp_transport_dst_release(transport);
3350 }
3351 break;
3352 default:
3353 break;
3354 }
3355 }
3356
3357 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk
3358 * for the given asconf parameter. If there is no response for this parameter,
3359 * return the error code based on the third argument 'no_err'.
3360 * ADDIP 4.1
3361 * A7) If an error response is received for a TLV parameter, all TLVs with no
3362 * response before the failed TLV are considered successful if not reported.
3363 * All TLVs after the failed response are considered unsuccessful unless a
3364 * specific success indication is present for the parameter.
3365 */
3366 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack,
3367 struct sctp_addip_param *asconf_param,
3368 int no_err)
3369 {
3370 struct sctp_addip_param *asconf_ack_param;
3371 struct sctp_errhdr *err_param;
3372 int asconf_ack_len;
3373 __be16 err_code;
3374 int length;
3375
3376 if (no_err)
3377 err_code = SCTP_ERROR_NO_ERROR;
3378 else
3379 err_code = SCTP_ERROR_REQ_REFUSED;
3380
3381 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) -
3382 sizeof(struct sctp_chunkhdr);
3383
3384 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to
3385 * the first asconf_ack parameter.
3386 */
3387 length = sizeof(struct sctp_addiphdr);
3388 asconf_ack_param = (struct sctp_addip_param *)(asconf_ack->skb->data +
3389 length);
3390 asconf_ack_len -= length;
3391
3392 while (asconf_ack_len > 0) {
3393 if (asconf_ack_param->crr_id == asconf_param->crr_id) {
3394 switch (asconf_ack_param->param_hdr.type) {
3395 case SCTP_PARAM_SUCCESS_REPORT:
3396 return SCTP_ERROR_NO_ERROR;
3397 case SCTP_PARAM_ERR_CAUSE:
3398 length = sizeof(*asconf_ack_param);
3399 err_param = (void *)asconf_ack_param + length;
3400 asconf_ack_len -= length;
3401 if (asconf_ack_len > 0)
3402 return err_param->cause;
3403 else
3404 return SCTP_ERROR_INV_PARAM;
3405 break;
3406 default:
3407 return SCTP_ERROR_INV_PARAM;
3408 }
3409 }
3410
3411 length = ntohs(asconf_ack_param->param_hdr.length);
3412 asconf_ack_param = (void *)asconf_ack_param + length;
3413 asconf_ack_len -= length;
3414 }
3415
3416 return err_code;
3417 }
3418
3419 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */
3420 int sctp_process_asconf_ack(struct sctp_association *asoc,
3421 struct sctp_chunk *asconf_ack)
3422 {
3423 struct sctp_chunk *asconf = asoc->addip_last_asconf;
3424 struct sctp_addip_param *asconf_param;
3425 __be16 err_code = SCTP_ERROR_NO_ERROR;
3426 union sctp_addr_param *addr_param;
3427 int asconf_len = asconf->skb->len;
3428 int all_param_pass = 0;
3429 int length = 0;
3430 int no_err = 1;
3431 int retval = 0;
3432
3433 /* Skip the chunkhdr and addiphdr from the last asconf sent and store
3434 * a pointer to address parameter.
3435 */
3436 length = sizeof(struct sctp_addip_chunk);
3437 addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
3438 asconf_len -= length;
3439
3440 /* Skip the address parameter in the last asconf sent and store a
3441 * pointer to the first asconf parameter.
3442 */
3443 length = ntohs(addr_param->p.length);
3444 asconf_param = (void *)addr_param + length;
3445 asconf_len -= length;
3446
3447 /* ADDIP 4.1
3448 * A8) If there is no response(s) to specific TLV parameter(s), and no
3449 * failures are indicated, then all request(s) are considered
3450 * successful.
3451 */
3452 if (asconf_ack->skb->len == sizeof(struct sctp_addiphdr))
3453 all_param_pass = 1;
3454
3455 /* Process the TLVs contained in the last sent ASCONF chunk. */
3456 while (asconf_len > 0) {
3457 if (all_param_pass)
3458 err_code = SCTP_ERROR_NO_ERROR;
3459 else {
3460 err_code = sctp_get_asconf_response(asconf_ack,
3461 asconf_param,
3462 no_err);
3463 if (no_err && (SCTP_ERROR_NO_ERROR != err_code))
3464 no_err = 0;
3465 }
3466
3467 switch (err_code) {
3468 case SCTP_ERROR_NO_ERROR:
3469 sctp_asconf_param_success(asoc, asconf_param);
3470 break;
3471
3472 case SCTP_ERROR_RSRC_LOW:
3473 retval = 1;
3474 break;
3475
3476 case SCTP_ERROR_UNKNOWN_PARAM:
3477 /* Disable sending this type of asconf parameter in
3478 * future.
3479 */
3480 asoc->peer.addip_disabled_mask |=
3481 asconf_param->param_hdr.type;
3482 break;
3483
3484 case SCTP_ERROR_REQ_REFUSED:
3485 case SCTP_ERROR_DEL_LAST_IP:
3486 case SCTP_ERROR_DEL_SRC_IP:
3487 default:
3488 break;
3489 }
3490
3491 /* Skip the processed asconf parameter and move to the next
3492 * one.
3493 */
3494 length = ntohs(asconf_param->param_hdr.length);
3495 asconf_param = (void *)asconf_param + length;
3496 asconf_len -= length;
3497 }
3498
3499 if (no_err && asoc->src_out_of_asoc_ok) {
3500 asoc->src_out_of_asoc_ok = 0;
3501 sctp_transport_immediate_rtx(asoc->peer.primary_path);
3502 }
3503
3504 /* Free the cached last sent asconf chunk. */
3505 list_del_init(&asconf->transmitted_list);
3506 sctp_chunk_free(asconf);
3507 asoc->addip_last_asconf = NULL;
3508
3509 return retval;
3510 }
3511
3512 /* Make a FWD TSN chunk. */
3513 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
3514 __u32 new_cum_tsn, size_t nstreams,
3515 struct sctp_fwdtsn_skip *skiplist)
3516 {
3517 struct sctp_chunk *retval = NULL;
3518 struct sctp_fwdtsn_hdr ftsn_hdr;
3519 struct sctp_fwdtsn_skip skip;
3520 size_t hint;
3521 int i;
3522
3523 hint = (nstreams + 1) * sizeof(__u32);
3524
3525 retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint, GFP_ATOMIC);
3526
3527 if (!retval)
3528 return NULL;
3529
3530 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn);
3531 retval->subh.fwdtsn_hdr =
3532 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr);
3533
3534 for (i = 0; i < nstreams; i++) {
3535 skip.stream = skiplist[i].stream;
3536 skip.ssn = skiplist[i].ssn;
3537 sctp_addto_chunk(retval, sizeof(skip), &skip);
3538 }
3539
3540 return retval;
3541 }
3542
3543 struct sctp_chunk *sctp_make_ifwdtsn(const struct sctp_association *asoc,
3544 __u32 new_cum_tsn, size_t nstreams,
3545 struct sctp_ifwdtsn_skip *skiplist)
3546 {
3547 struct sctp_chunk *retval = NULL;
3548 struct sctp_ifwdtsn_hdr ftsn_hdr;
3549 size_t hint;
3550
3551 hint = (nstreams + 1) * sizeof(__u32);
3552
3553 retval = sctp_make_control(asoc, SCTP_CID_I_FWD_TSN, 0, hint,
3554 GFP_ATOMIC);
3555 if (!retval)
3556 return NULL;
3557
3558 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn);
3559 retval->subh.ifwdtsn_hdr =
3560 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr);
3561
3562 sctp_addto_chunk(retval, nstreams * sizeof(skiplist[0]), skiplist);
3563
3564 return retval;
3565 }
3566
3567 /* RE-CONFIG 3.1 (RE-CONFIG chunk)
3568 * 0 1 2 3
3569 * 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
3570 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3571 * | Type = 130 | Chunk Flags | Chunk Length |
3572 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3573 * \ \
3574 * / Re-configuration Parameter /
3575 * \ \
3576 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3577 * \ \
3578 * / Re-configuration Parameter (optional) /
3579 * \ \
3580 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3581 */
3582 static struct sctp_chunk *sctp_make_reconf(const struct sctp_association *asoc,
3583 int length)
3584 {
3585 struct sctp_reconf_chunk *reconf;
3586 struct sctp_chunk *retval;
3587
3588 retval = sctp_make_control(asoc, SCTP_CID_RECONF, 0, length,
3589 GFP_ATOMIC);
3590 if (!retval)
3591 return NULL;
3592
3593 reconf = (struct sctp_reconf_chunk *)retval->chunk_hdr;
3594 retval->param_hdr.v = reconf->params;
3595
3596 return retval;
3597 }
3598
3599 /* RE-CONFIG 4.1 (STREAM OUT RESET)
3600 * 0 1 2 3
3601 * 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
3602 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3603 * | Parameter Type = 13 | Parameter Length = 16 + 2 * N |
3604 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3605 * | Re-configuration Request Sequence Number |
3606 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3607 * | Re-configuration Response Sequence Number |
3608 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3609 * | Sender's Last Assigned TSN |
3610 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3611 * | Stream Number 1 (optional) | Stream Number 2 (optional) |
3612 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3613 * / ...... /
3614 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3615 * | Stream Number N-1 (optional) | Stream Number N (optional) |
3616 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3617 *
3618 * RE-CONFIG 4.2 (STREAM IN RESET)
3619 * 0 1 2 3
3620 * 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
3621 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3622 * | Parameter Type = 14 | Parameter Length = 8 + 2 * N |
3623 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3624 * | Re-configuration Request Sequence Number |
3625 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3626 * | Stream Number 1 (optional) | Stream Number 2 (optional) |
3627 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3628 * / ...... /
3629 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3630 * | Stream Number N-1 (optional) | Stream Number N (optional) |
3631 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3632 */
3633 struct sctp_chunk *sctp_make_strreset_req(
3634 const struct sctp_association *asoc,
3635 __u16 stream_num, __be16 *stream_list,
3636 bool out, bool in)
3637 {
3638 __u16 stream_len = stream_num * sizeof(__u16);
3639 struct sctp_strreset_outreq outreq;
3640 struct sctp_strreset_inreq inreq;
3641 struct sctp_chunk *retval;
3642 __u16 outlen, inlen;
3643
3644 outlen = (sizeof(outreq) + stream_len) * out;
3645 inlen = (sizeof(inreq) + stream_len) * in;
3646
3647 retval = sctp_make_reconf(asoc, outlen + inlen);
3648 if (!retval)
3649 return NULL;
3650
3651 if (outlen) {
3652 outreq.param_hdr.type = SCTP_PARAM_RESET_OUT_REQUEST;
3653 outreq.param_hdr.length = htons(outlen);
3654 outreq.request_seq = htonl(asoc->strreset_outseq);
3655 outreq.response_seq = htonl(asoc->strreset_inseq - 1);
3656 outreq.send_reset_at_tsn = htonl(asoc->next_tsn - 1);
3657
3658 sctp_addto_chunk(retval, sizeof(outreq), &outreq);
3659
3660 if (stream_len)
3661 sctp_addto_chunk(retval, stream_len, stream_list);
3662 }
3663
3664 if (inlen) {
3665 inreq.param_hdr.type = SCTP_PARAM_RESET_IN_REQUEST;
3666 inreq.param_hdr.length = htons(inlen);
3667 inreq.request_seq = htonl(asoc->strreset_outseq + out);
3668
3669 sctp_addto_chunk(retval, sizeof(inreq), &inreq);
3670
3671 if (stream_len)
3672 sctp_addto_chunk(retval, stream_len, stream_list);
3673 }
3674
3675 return retval;
3676 }
3677
3678 /* RE-CONFIG 4.3 (SSN/TSN RESET ALL)
3679 * 0 1 2 3
3680 * 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
3681 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3682 * | Parameter Type = 15 | Parameter Length = 8 |
3683 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3684 * | Re-configuration Request Sequence Number |
3685 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3686 */
3687 struct sctp_chunk *sctp_make_strreset_tsnreq(
3688 const struct sctp_association *asoc)
3689 {
3690 struct sctp_strreset_tsnreq tsnreq;
3691 __u16 length = sizeof(tsnreq);
3692 struct sctp_chunk *retval;
3693
3694 retval = sctp_make_reconf(asoc, length);
3695 if (!retval)
3696 return NULL;
3697
3698 tsnreq.param_hdr.type = SCTP_PARAM_RESET_TSN_REQUEST;
3699 tsnreq.param_hdr.length = htons(length);
3700 tsnreq.request_seq = htonl(asoc->strreset_outseq);
3701
3702 sctp_addto_chunk(retval, sizeof(tsnreq), &tsnreq);
3703
3704 return retval;
3705 }
3706
3707 /* RE-CONFIG 4.5/4.6 (ADD STREAM)
3708 * 0 1 2 3
3709 * 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
3710 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3711 * | Parameter Type = 17 | Parameter Length = 12 |
3712 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3713 * | Re-configuration Request Sequence Number |
3714 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3715 * | Number of new streams | Reserved |
3716 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3717 */
3718 struct sctp_chunk *sctp_make_strreset_addstrm(
3719 const struct sctp_association *asoc,
3720 __u16 out, __u16 in)
3721 {
3722 struct sctp_strreset_addstrm addstrm;
3723 __u16 size = sizeof(addstrm);
3724 struct sctp_chunk *retval;
3725
3726 retval = sctp_make_reconf(asoc, (!!out + !!in) * size);
3727 if (!retval)
3728 return NULL;
3729
3730 if (out) {
3731 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_OUT_STREAMS;
3732 addstrm.param_hdr.length = htons(size);
3733 addstrm.number_of_streams = htons(out);
3734 addstrm.request_seq = htonl(asoc->strreset_outseq);
3735 addstrm.reserved = 0;
3736
3737 sctp_addto_chunk(retval, size, &addstrm);
3738 }
3739
3740 if (in) {
3741 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_IN_STREAMS;
3742 addstrm.param_hdr.length = htons(size);
3743 addstrm.number_of_streams = htons(in);
3744 addstrm.request_seq = htonl(asoc->strreset_outseq + !!out);
3745 addstrm.reserved = 0;
3746
3747 sctp_addto_chunk(retval, size, &addstrm);
3748 }
3749
3750 return retval;
3751 }
3752
3753 /* RE-CONFIG 4.4 (RESP)
3754 * 0 1 2 3
3755 * 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
3756 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3757 * | Parameter Type = 16 | Parameter Length |
3758 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3759 * | Re-configuration Response Sequence Number |
3760 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3761 * | Result |
3762 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3763 */
3764 struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc,
3765 __u32 result, __u32 sn)
3766 {
3767 struct sctp_strreset_resp resp;
3768 __u16 length = sizeof(resp);
3769 struct sctp_chunk *retval;
3770
3771 retval = sctp_make_reconf(asoc, length);
3772 if (!retval)
3773 return NULL;
3774
3775 resp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE;
3776 resp.param_hdr.length = htons(length);
3777 resp.response_seq = htonl(sn);
3778 resp.result = htonl(result);
3779
3780 sctp_addto_chunk(retval, sizeof(resp), &resp);
3781
3782 return retval;
3783 }
3784
3785 /* RE-CONFIG 4.4 OPTIONAL (TSNRESP)
3786 * 0 1 2 3
3787 * 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
3788 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3789 * | Parameter Type = 16 | Parameter Length |
3790 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3791 * | Re-configuration Response Sequence Number |
3792 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3793 * | Result |
3794 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3795 * | Sender's Next TSN (optional) |
3796 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3797 * | Receiver's Next TSN (optional) |
3798 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3799 */
3800 struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc,
3801 __u32 result, __u32 sn,
3802 __u32 sender_tsn,
3803 __u32 receiver_tsn)
3804 {
3805 struct sctp_strreset_resptsn tsnresp;
3806 __u16 length = sizeof(tsnresp);
3807 struct sctp_chunk *retval;
3808
3809 retval = sctp_make_reconf(asoc, length);
3810 if (!retval)
3811 return NULL;
3812
3813 tsnresp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE;
3814 tsnresp.param_hdr.length = htons(length);
3815
3816 tsnresp.response_seq = htonl(sn);
3817 tsnresp.result = htonl(result);
3818 tsnresp.senders_next_tsn = htonl(sender_tsn);
3819 tsnresp.receivers_next_tsn = htonl(receiver_tsn);
3820
3821 sctp_addto_chunk(retval, sizeof(tsnresp), &tsnresp);
3822
3823 return retval;
3824 }
3825
3826 bool sctp_verify_reconf(const struct sctp_association *asoc,
3827 struct sctp_chunk *chunk,
3828 struct sctp_paramhdr **errp)
3829 {
3830 struct sctp_reconf_chunk *hdr;
3831 union sctp_params param;
3832 __be16 last = 0;
3833 __u16 cnt = 0;
3834
3835 hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr;
3836 sctp_walk_params(param, hdr, params) {
3837 __u16 length = ntohs(param.p->length);
3838
3839 *errp = param.p;
3840 if (cnt++ > 2)
3841 return false;
3842 switch (param.p->type) {
3843 case SCTP_PARAM_RESET_OUT_REQUEST:
3844 if (length < sizeof(struct sctp_strreset_outreq) ||
3845 (last && last != SCTP_PARAM_RESET_RESPONSE &&
3846 last != SCTP_PARAM_RESET_IN_REQUEST))
3847 return false;
3848 break;
3849 case SCTP_PARAM_RESET_IN_REQUEST:
3850 if (length < sizeof(struct sctp_strreset_inreq) ||
3851 (last && last != SCTP_PARAM_RESET_OUT_REQUEST))
3852 return false;
3853 break;
3854 case SCTP_PARAM_RESET_RESPONSE:
3855 if ((length != sizeof(struct sctp_strreset_resp) &&
3856 length != sizeof(struct sctp_strreset_resptsn)) ||
3857 (last && last != SCTP_PARAM_RESET_RESPONSE &&
3858 last != SCTP_PARAM_RESET_OUT_REQUEST))
3859 return false;
3860 break;
3861 case SCTP_PARAM_RESET_TSN_REQUEST:
3862 if (length !=
3863 sizeof(struct sctp_strreset_tsnreq) || last)
3864 return false;
3865 break;
3866 case SCTP_PARAM_RESET_ADD_IN_STREAMS:
3867 if (length != sizeof(struct sctp_strreset_addstrm) ||
3868 (last && last != SCTP_PARAM_RESET_ADD_OUT_STREAMS))
3869 return false;
3870 break;
3871 case SCTP_PARAM_RESET_ADD_OUT_STREAMS:
3872 if (length != sizeof(struct sctp_strreset_addstrm) ||
3873 (last && last != SCTP_PARAM_RESET_ADD_IN_STREAMS))
3874 return false;
3875 break;
3876 default:
3877 return false;
3878 }
3879
3880 last = param.p->type;
3881 }
3882
3883 return true;
3884 }
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