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1// SPDX-License-Identifier: GPL-2.0-or-later
2/* SCTP kernel implementation
3 * (C) Copyright IBM Corp. 2001, 2004
4 * Copyright (c) 1999-2000 Cisco, Inc.
5 * Copyright (c) 1999-2001 Motorola, Inc.
6 * Copyright (c) 2001-2002 Intel Corp.
7 *
8 * This file is part of the SCTP kernel implementation
9 *
10 * These functions work with the state functions in sctp_sm_statefuns.c
11 * to implement the state operations. These functions implement the
12 * steps which require modifying existing data structures.
13 *
14 * Please send any bug reports or fixes you make to the
15 * email address(es):
16 * lksctp developers <linux-sctp@vger.kernel.org>
17 *
18 * Written or modified by:
19 * La Monte H.P. Yarroll <piggy@acm.org>
20 * Karl Knutson <karl@athena.chicago.il.us>
21 * C. Robin <chris@hundredacre.ac.uk>
22 * Jon Grimm <jgrimm@us.ibm.com>
23 * Xingang Guo <xingang.guo@intel.com>
24 * Dajiang Zhang <dajiang.zhang@nokia.com>
25 * Sridhar Samudrala <sri@us.ibm.com>
26 * Daisy Chang <daisyc@us.ibm.com>
27 * Ardelle Fan <ardelle.fan@intel.com>
28 * Kevin Gao <kevin.gao@intel.com>
29 */
30
31#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
32
33#include <crypto/hash.h>
34#include <linux/types.h>
35#include <linux/kernel.h>
36#include <linux/ip.h>
37#include <linux/ipv6.h>
38#include <linux/net.h>
39#include <linux/inet.h>
40#include <linux/scatterlist.h>
41#include <linux/slab.h>
42#include <net/sock.h>
43
44#include <linux/skbuff.h>
45#include <linux/random.h> /* for get_random_bytes */
46#include <net/sctp/sctp.h>
47#include <net/sctp/sm.h>
48
49static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc,
50 __u8 type, __u8 flags, int paylen,
51 gfp_t gfp);
52static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc,
53 __u8 flags, int paylen, gfp_t gfp);
54static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc,
55 __u8 type, __u8 flags, int paylen,
56 gfp_t gfp);
57static struct sctp_cookie_param *sctp_pack_cookie(
58 const struct sctp_endpoint *ep,
59 const struct sctp_association *asoc,
60 const struct sctp_chunk *init_chunk,
61 int *cookie_len,
62 const __u8 *raw_addrs, int addrs_len);
63static int sctp_process_param(struct sctp_association *asoc,
64 union sctp_params param,
65 const union sctp_addr *peer_addr,
66 gfp_t gfp);
67static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
68 const void *data);
69
70/* Control chunk destructor */
71static void sctp_control_release_owner(struct sk_buff *skb)
72{
73 struct sctp_chunk *chunk = skb_shinfo(skb)->destructor_arg;
74
75 if (chunk->shkey) {
76 struct sctp_shared_key *shkey = chunk->shkey;
77 struct sctp_association *asoc = chunk->asoc;
78
79 /* refcnt == 2 and !list_empty mean after this release, it's
80 * not being used anywhere, and it's time to notify userland
81 * that this shkey can be freed if it's been deactivated.
82 */
83 if (shkey->deactivated && !list_empty(&shkey->key_list) &&
84 refcount_read(&shkey->refcnt) == 2) {
85 struct sctp_ulpevent *ev;
86
87 ev = sctp_ulpevent_make_authkey(asoc, shkey->key_id,
88 SCTP_AUTH_FREE_KEY,
89 GFP_KERNEL);
90 if (ev)
91 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
92 }
93 sctp_auth_shkey_release(chunk->shkey);
94 }
95}
96
97static void sctp_control_set_owner_w(struct sctp_chunk *chunk)
98{
99 struct sctp_association *asoc = chunk->asoc;
100 struct sk_buff *skb = chunk->skb;
101
102 /* TODO: properly account for control chunks.
103 * To do it right we'll need:
104 * 1) endpoint if association isn't known.
105 * 2) proper memory accounting.
106 *
107 * For now don't do anything for now.
108 */
109 if (chunk->auth) {
110 chunk->shkey = asoc->shkey;
111 sctp_auth_shkey_hold(chunk->shkey);
112 }
113 skb->sk = asoc ? asoc->base.sk : NULL;
114 skb_shinfo(skb)->destructor_arg = chunk;
115 skb->destructor = sctp_control_release_owner;
116}
117
118/* What was the inbound interface for this chunk? */
119int sctp_chunk_iif(const struct sctp_chunk *chunk)
120{
121 struct sk_buff *skb = chunk->skb;
122
123 return SCTP_INPUT_CB(skb)->af->skb_iif(skb);
124}
125
126/* RFC 2960 3.3.2 Initiation (INIT) (1)
127 *
128 * Note 2: The ECN capable field is reserved for future use of
129 * Explicit Congestion Notification.
130 */
131static const struct sctp_paramhdr ecap_param = {
132 SCTP_PARAM_ECN_CAPABLE,
133 cpu_to_be16(sizeof(struct sctp_paramhdr)),
134};
135static const struct sctp_paramhdr prsctp_param = {
136 SCTP_PARAM_FWD_TSN_SUPPORT,
137 cpu_to_be16(sizeof(struct sctp_paramhdr)),
138};
139
140/* A helper to initialize an op error inside a provided chunk, as most
141 * cause codes will be embedded inside an abort chunk.
142 */
143int sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code,
144 size_t paylen)
145{
146 struct sctp_errhdr err;
147 __u16 len;
148
149 /* Cause code constants are now defined in network order. */
150 err.cause = cause_code;
151 len = sizeof(err) + paylen;
152 err.length = htons(len);
153
154 if (skb_tailroom(chunk->skb) < len)
155 return -ENOSPC;
156
157 chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(err), &err);
158
159 return 0;
160}
161
162/* 3.3.2 Initiation (INIT) (1)
163 *
164 * This chunk is used to initiate a SCTP association between two
165 * endpoints. The format of the INIT chunk is shown below:
166 *
167 * 0 1 2 3
168 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
169 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
170 * | Type = 1 | Chunk Flags | Chunk Length |
171 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
172 * | Initiate Tag |
173 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
174 * | Advertised Receiver Window Credit (a_rwnd) |
175 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
176 * | Number of Outbound Streams | Number of Inbound Streams |
177 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
178 * | Initial TSN |
179 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
180 * \ \
181 * / Optional/Variable-Length Parameters /
182 * \ \
183 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
184 *
185 *
186 * The INIT chunk contains the following parameters. Unless otherwise
187 * noted, each parameter MUST only be included once in the INIT chunk.
188 *
189 * Fixed Parameters Status
190 * ----------------------------------------------
191 * Initiate Tag Mandatory
192 * Advertised Receiver Window Credit Mandatory
193 * Number of Outbound Streams Mandatory
194 * Number of Inbound Streams Mandatory
195 * Initial TSN Mandatory
196 *
197 * Variable Parameters Status Type Value
198 * -------------------------------------------------------------
199 * IPv4 Address (Note 1) Optional 5
200 * IPv6 Address (Note 1) Optional 6
201 * Cookie Preservative Optional 9
202 * Reserved for ECN Capable (Note 2) Optional 32768 (0x8000)
203 * Host Name Address (Note 3) Optional 11
204 * Supported Address Types (Note 4) Optional 12
205 */
206struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc,
207 const struct sctp_bind_addr *bp,
208 gfp_t gfp, int vparam_len)
209{
210 struct sctp_supported_ext_param ext_param;
211 struct sctp_adaptation_ind_param aiparam;
212 struct sctp_paramhdr *auth_chunks = NULL;
213 struct sctp_paramhdr *auth_hmacs = NULL;
214 struct sctp_supported_addrs_param sat;
215 struct sctp_endpoint *ep = asoc->ep;
216 struct sctp_chunk *retval = NULL;
217 int num_types, addrs_len = 0;
218 struct sctp_inithdr init;
219 union sctp_params addrs;
220 struct sctp_sock *sp;
221 __u8 extensions[5];
222 size_t chunksize;
223 __be16 types[2];
224 int num_ext = 0;
225
226 /* RFC 2960 3.3.2 Initiation (INIT) (1)
227 *
228 * Note 1: The INIT chunks can contain multiple addresses that
229 * can be IPv4 and/or IPv6 in any combination.
230 */
231
232 /* Convert the provided bind address list to raw format. */
233 addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp);
234
235 init.init_tag = htonl(asoc->c.my_vtag);
236 init.a_rwnd = htonl(asoc->rwnd);
237 init.num_outbound_streams = htons(asoc->c.sinit_num_ostreams);
238 init.num_inbound_streams = htons(asoc->c.sinit_max_instreams);
239 init.initial_tsn = htonl(asoc->c.initial_tsn);
240
241 /* How many address types are needed? */
242 sp = sctp_sk(asoc->base.sk);
243 num_types = sp->pf->supported_addrs(sp, types);
244
245 chunksize = sizeof(init) + addrs_len;
246 chunksize += SCTP_PAD4(SCTP_SAT_LEN(num_types));
247
248 if (asoc->ep->ecn_enable)
249 chunksize += sizeof(ecap_param);
250
251 if (asoc->ep->prsctp_enable)
252 chunksize += sizeof(prsctp_param);
253
254 /* ADDIP: Section 4.2.7:
255 * An implementation supporting this extension [ADDIP] MUST list
256 * the ASCONF,the ASCONF-ACK, and the AUTH chunks in its INIT and
257 * INIT-ACK parameters.
258 */
259 if (asoc->ep->asconf_enable) {
260 extensions[num_ext] = SCTP_CID_ASCONF;
261 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
262 num_ext += 2;
263 }
264
265 if (asoc->ep->reconf_enable) {
266 extensions[num_ext] = SCTP_CID_RECONF;
267 num_ext += 1;
268 }
269
270 if (sp->adaptation_ind)
271 chunksize += sizeof(aiparam);
272
273 if (asoc->ep->intl_enable) {
274 extensions[num_ext] = SCTP_CID_I_DATA;
275 num_ext += 1;
276 }
277
278 chunksize += vparam_len;
279
280 /* Account for AUTH related parameters */
281 if (ep->auth_enable) {
282 /* Add random parameter length*/
283 chunksize += sizeof(asoc->c.auth_random);
284
285 /* Add HMACS parameter length if any were defined */
286 auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs;
287 if (auth_hmacs->length)
288 chunksize += SCTP_PAD4(ntohs(auth_hmacs->length));
289 else
290 auth_hmacs = NULL;
291
292 /* Add CHUNKS parameter length */
293 auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks;
294 if (auth_chunks->length)
295 chunksize += SCTP_PAD4(ntohs(auth_chunks->length));
296 else
297 auth_chunks = NULL;
298
299 extensions[num_ext] = SCTP_CID_AUTH;
300 num_ext += 1;
301 }
302
303 /* If we have any extensions to report, account for that */
304 if (num_ext)
305 chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext);
306
307 /* RFC 2960 3.3.2 Initiation (INIT) (1)
308 *
309 * Note 3: An INIT chunk MUST NOT contain more than one Host
310 * Name address parameter. Moreover, the sender of the INIT
311 * MUST NOT combine any other address types with the Host Name
312 * address in the INIT. The receiver of INIT MUST ignore any
313 * other address types if the Host Name address parameter is
314 * present in the received INIT chunk.
315 *
316 * PLEASE DO NOT FIXME [This version does not support Host Name.]
317 */
318
319 retval = sctp_make_control(asoc, SCTP_CID_INIT, 0, chunksize, gfp);
320 if (!retval)
321 goto nodata;
322
323 retval->subh.init_hdr =
324 sctp_addto_chunk(retval, sizeof(init), &init);
325 retval->param_hdr.v =
326 sctp_addto_chunk(retval, addrs_len, addrs.v);
327
328 /* RFC 2960 3.3.2 Initiation (INIT) (1)
329 *
330 * Note 4: This parameter, when present, specifies all the
331 * address types the sending endpoint can support. The absence
332 * of this parameter indicates that the sending endpoint can
333 * support any address type.
334 */
335 sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES;
336 sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types));
337 sctp_addto_chunk(retval, sizeof(sat), &sat);
338 sctp_addto_chunk(retval, num_types * sizeof(__u16), &types);
339
340 if (asoc->ep->ecn_enable)
341 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
342
343 /* Add the supported extensions parameter. Be nice and add this
344 * fist before addiding the parameters for the extensions themselves
345 */
346 if (num_ext) {
347 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
348 ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext);
349 sctp_addto_chunk(retval, sizeof(ext_param), &ext_param);
350 sctp_addto_param(retval, num_ext, extensions);
351 }
352
353 if (asoc->ep->prsctp_enable)
354 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
355
356 if (sp->adaptation_ind) {
357 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
358 aiparam.param_hdr.length = htons(sizeof(aiparam));
359 aiparam.adaptation_ind = htonl(sp->adaptation_ind);
360 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
361 }
362
363 /* Add SCTP-AUTH chunks to the parameter list */
364 if (ep->auth_enable) {
365 sctp_addto_chunk(retval, sizeof(asoc->c.auth_random),
366 asoc->c.auth_random);
367 if (auth_hmacs)
368 sctp_addto_chunk(retval, ntohs(auth_hmacs->length),
369 auth_hmacs);
370 if (auth_chunks)
371 sctp_addto_chunk(retval, ntohs(auth_chunks->length),
372 auth_chunks);
373 }
374nodata:
375 kfree(addrs.v);
376 return retval;
377}
378
379struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc,
380 const struct sctp_chunk *chunk,
381 gfp_t gfp, int unkparam_len)
382{
383 struct sctp_supported_ext_param ext_param;
384 struct sctp_adaptation_ind_param aiparam;
385 struct sctp_paramhdr *auth_chunks = NULL;
386 struct sctp_paramhdr *auth_random = NULL;
387 struct sctp_paramhdr *auth_hmacs = NULL;
388 struct sctp_chunk *retval = NULL;
389 struct sctp_cookie_param *cookie;
390 struct sctp_inithdr initack;
391 union sctp_params addrs;
392 struct sctp_sock *sp;
393 __u8 extensions[5];
394 size_t chunksize;
395 int num_ext = 0;
396 int cookie_len;
397 int addrs_len;
398
399 /* Note: there may be no addresses to embed. */
400 addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp);
401
402 initack.init_tag = htonl(asoc->c.my_vtag);
403 initack.a_rwnd = htonl(asoc->rwnd);
404 initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams);
405 initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams);
406 initack.initial_tsn = htonl(asoc->c.initial_tsn);
407
408 /* FIXME: We really ought to build the cookie right
409 * into the packet instead of allocating more fresh memory.
410 */
411 cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len,
412 addrs.v, addrs_len);
413 if (!cookie)
414 goto nomem_cookie;
415
416 /* Calculate the total size of allocation, include the reserved
417 * space for reporting unknown parameters if it is specified.
418 */
419 sp = sctp_sk(asoc->base.sk);
420 chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len;
421
422 /* Tell peer that we'll do ECN only if peer advertised such cap. */
423 if (asoc->peer.ecn_capable)
424 chunksize += sizeof(ecap_param);
425
426 if (asoc->peer.prsctp_capable)
427 chunksize += sizeof(prsctp_param);
428
429 if (asoc->peer.asconf_capable) {
430 extensions[num_ext] = SCTP_CID_ASCONF;
431 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
432 num_ext += 2;
433 }
434
435 if (asoc->peer.reconf_capable) {
436 extensions[num_ext] = SCTP_CID_RECONF;
437 num_ext += 1;
438 }
439
440 if (sp->adaptation_ind)
441 chunksize += sizeof(aiparam);
442
443 if (asoc->peer.intl_capable) {
444 extensions[num_ext] = SCTP_CID_I_DATA;
445 num_ext += 1;
446 }
447
448 if (asoc->peer.auth_capable) {
449 auth_random = (struct sctp_paramhdr *)asoc->c.auth_random;
450 chunksize += ntohs(auth_random->length);
451
452 auth_hmacs = (struct sctp_paramhdr *)asoc->c.auth_hmacs;
453 if (auth_hmacs->length)
454 chunksize += SCTP_PAD4(ntohs(auth_hmacs->length));
455 else
456 auth_hmacs = NULL;
457
458 auth_chunks = (struct sctp_paramhdr *)asoc->c.auth_chunks;
459 if (auth_chunks->length)
460 chunksize += SCTP_PAD4(ntohs(auth_chunks->length));
461 else
462 auth_chunks = NULL;
463
464 extensions[num_ext] = SCTP_CID_AUTH;
465 num_ext += 1;
466 }
467
468 if (num_ext)
469 chunksize += SCTP_PAD4(sizeof(ext_param) + num_ext);
470
471 /* Now allocate and fill out the chunk. */
472 retval = sctp_make_control(asoc, SCTP_CID_INIT_ACK, 0, chunksize, gfp);
473 if (!retval)
474 goto nomem_chunk;
475
476 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
477 *
478 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
479 * HEARTBEAT ACK, * etc.) to the same destination transport
480 * address from which it received the DATA or control chunk
481 * to which it is replying.
482 *
483 * [INIT ACK back to where the INIT came from.]
484 */
485 if (chunk->transport)
486 retval->transport =
487 sctp_assoc_lookup_paddr(asoc,
488 &chunk->transport->ipaddr);
489
490 retval->subh.init_hdr =
491 sctp_addto_chunk(retval, sizeof(initack), &initack);
492 retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v);
493 sctp_addto_chunk(retval, cookie_len, cookie);
494 if (asoc->peer.ecn_capable)
495 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
496 if (num_ext) {
497 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
498 ext_param.param_hdr.length = htons(sizeof(ext_param) + num_ext);
499 sctp_addto_chunk(retval, sizeof(ext_param), &ext_param);
500 sctp_addto_param(retval, num_ext, extensions);
501 }
502 if (asoc->peer.prsctp_capable)
503 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
504
505 if (sp->adaptation_ind) {
506 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
507 aiparam.param_hdr.length = htons(sizeof(aiparam));
508 aiparam.adaptation_ind = htonl(sp->adaptation_ind);
509 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
510 }
511
512 if (asoc->peer.auth_capable) {
513 sctp_addto_chunk(retval, ntohs(auth_random->length),
514 auth_random);
515 if (auth_hmacs)
516 sctp_addto_chunk(retval, ntohs(auth_hmacs->length),
517 auth_hmacs);
518 if (auth_chunks)
519 sctp_addto_chunk(retval, ntohs(auth_chunks->length),
520 auth_chunks);
521 }
522
523 /* We need to remove the const qualifier at this point. */
524 retval->asoc = (struct sctp_association *) asoc;
525
526nomem_chunk:
527 kfree(cookie);
528nomem_cookie:
529 kfree(addrs.v);
530 return retval;
531}
532
533/* 3.3.11 Cookie Echo (COOKIE ECHO) (10):
534 *
535 * This chunk is used only during the initialization of an association.
536 * It is sent by the initiator of an association to its peer to complete
537 * the initialization process. This chunk MUST precede any DATA chunk
538 * sent within the association, but MAY be bundled with one or more DATA
539 * chunks in the same packet.
540 *
541 * 0 1 2 3
542 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
543 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
544 * | Type = 10 |Chunk Flags | Length |
545 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
546 * / Cookie /
547 * \ \
548 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
549 *
550 * Chunk Flags: 8 bit
551 *
552 * Set to zero on transmit and ignored on receipt.
553 *
554 * Length: 16 bits (unsigned integer)
555 *
556 * Set to the size of the chunk in bytes, including the 4 bytes of
557 * the chunk header and the size of the Cookie.
558 *
559 * Cookie: variable size
560 *
561 * This field must contain the exact cookie received in the
562 * State Cookie parameter from the previous INIT ACK.
563 *
564 * An implementation SHOULD make the cookie as small as possible
565 * to insure interoperability.
566 */
567struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc,
568 const struct sctp_chunk *chunk)
569{
570 struct sctp_chunk *retval;
571 int cookie_len;
572 void *cookie;
573
574 cookie = asoc->peer.cookie;
575 cookie_len = asoc->peer.cookie_len;
576
577 /* Build a cookie echo chunk. */
578 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ECHO, 0,
579 cookie_len, GFP_ATOMIC);
580 if (!retval)
581 goto nodata;
582 retval->subh.cookie_hdr =
583 sctp_addto_chunk(retval, cookie_len, cookie);
584
585 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
586 *
587 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
588 * HEARTBEAT ACK, * etc.) to the same destination transport
589 * address from which it * received the DATA or control chunk
590 * to which it is replying.
591 *
592 * [COOKIE ECHO back to where the INIT ACK came from.]
593 */
594 if (chunk)
595 retval->transport = chunk->transport;
596
597nodata:
598 return retval;
599}
600
601/* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11):
602 *
603 * This chunk is used only during the initialization of an
604 * association. It is used to acknowledge the receipt of a COOKIE
605 * ECHO chunk. This chunk MUST precede any DATA or SACK chunk sent
606 * within the association, but MAY be bundled with one or more DATA
607 * chunks or SACK chunk in the same SCTP packet.
608 *
609 * 0 1 2 3
610 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
611 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
612 * | Type = 11 |Chunk Flags | Length = 4 |
613 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
614 *
615 * Chunk Flags: 8 bits
616 *
617 * Set to zero on transmit and ignored on receipt.
618 */
619struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc,
620 const struct sctp_chunk *chunk)
621{
622 struct sctp_chunk *retval;
623
624 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ACK, 0, 0, GFP_ATOMIC);
625
626 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
627 *
628 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
629 * HEARTBEAT ACK, * etc.) to the same destination transport
630 * address from which it * received the DATA or control chunk
631 * to which it is replying.
632 *
633 * [COOKIE ACK back to where the COOKIE ECHO came from.]
634 */
635 if (retval && chunk && chunk->transport)
636 retval->transport =
637 sctp_assoc_lookup_paddr(asoc,
638 &chunk->transport->ipaddr);
639
640 return retval;
641}
642
643/*
644 * Appendix A: Explicit Congestion Notification:
645 * CWR:
646 *
647 * RFC 2481 details a specific bit for a sender to send in the header of
648 * its next outbound TCP segment to indicate to its peer that it has
649 * reduced its congestion window. This is termed the CWR bit. For
650 * SCTP the same indication is made by including the CWR chunk.
651 * This chunk contains one data element, i.e. the TSN number that
652 * was sent in the ECNE chunk. This element represents the lowest
653 * TSN number in the datagram that was originally marked with the
654 * CE bit.
655 *
656 * 0 1 2 3
657 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
658 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
659 * | Chunk Type=13 | Flags=00000000| Chunk Length = 8 |
660 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
661 * | Lowest TSN Number |
662 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
663 *
664 * Note: The CWR is considered a Control chunk.
665 */
666struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc,
667 const __u32 lowest_tsn,
668 const struct sctp_chunk *chunk)
669{
670 struct sctp_chunk *retval;
671 struct sctp_cwrhdr cwr;
672
673 cwr.lowest_tsn = htonl(lowest_tsn);
674 retval = sctp_make_control(asoc, SCTP_CID_ECN_CWR, 0,
675 sizeof(cwr), GFP_ATOMIC);
676
677 if (!retval)
678 goto nodata;
679
680 retval->subh.ecn_cwr_hdr =
681 sctp_addto_chunk(retval, sizeof(cwr), &cwr);
682
683 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
684 *
685 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
686 * HEARTBEAT ACK, * etc.) to the same destination transport
687 * address from which it * received the DATA or control chunk
688 * to which it is replying.
689 *
690 * [Report a reduced congestion window back to where the ECNE
691 * came from.]
692 */
693 if (chunk)
694 retval->transport = chunk->transport;
695
696nodata:
697 return retval;
698}
699
700/* Make an ECNE chunk. This is a congestion experienced report. */
701struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc,
702 const __u32 lowest_tsn)
703{
704 struct sctp_chunk *retval;
705 struct sctp_ecnehdr ecne;
706
707 ecne.lowest_tsn = htonl(lowest_tsn);
708 retval = sctp_make_control(asoc, SCTP_CID_ECN_ECNE, 0,
709 sizeof(ecne), GFP_ATOMIC);
710 if (!retval)
711 goto nodata;
712 retval->subh.ecne_hdr =
713 sctp_addto_chunk(retval, sizeof(ecne), &ecne);
714
715nodata:
716 return retval;
717}
718
719/* Make a DATA chunk for the given association from the provided
720 * parameters. However, do not populate the data payload.
721 */
722struct sctp_chunk *sctp_make_datafrag_empty(const struct sctp_association *asoc,
723 const struct sctp_sndrcvinfo *sinfo,
724 int len, __u8 flags, gfp_t gfp)
725{
726 struct sctp_chunk *retval;
727 struct sctp_datahdr dp;
728
729 /* We assign the TSN as LATE as possible, not here when
730 * creating the chunk.
731 */
732 memset(&dp, 0, sizeof(dp));
733 dp.ppid = sinfo->sinfo_ppid;
734 dp.stream = htons(sinfo->sinfo_stream);
735
736 /* Set the flags for an unordered send. */
737 if (sinfo->sinfo_flags & SCTP_UNORDERED)
738 flags |= SCTP_DATA_UNORDERED;
739
740 retval = sctp_make_data(asoc, flags, sizeof(dp) + len, gfp);
741 if (!retval)
742 return NULL;
743
744 retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp);
745 memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo));
746
747 return retval;
748}
749
750/* Create a selective ackowledgement (SACK) for the given
751 * association. This reports on which TSN's we've seen to date,
752 * including duplicates and gaps.
753 */
754struct sctp_chunk *sctp_make_sack(struct sctp_association *asoc)
755{
756 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
757 struct sctp_gap_ack_block gabs[SCTP_MAX_GABS];
758 __u16 num_gabs, num_dup_tsns;
759 struct sctp_transport *trans;
760 struct sctp_chunk *retval;
761 struct sctp_sackhdr sack;
762 __u32 ctsn;
763 int len;
764
765 memset(gabs, 0, sizeof(gabs));
766 ctsn = sctp_tsnmap_get_ctsn(map);
767
768 pr_debug("%s: sackCTSNAck sent:0x%x\n", __func__, ctsn);
769
770 /* How much room is needed in the chunk? */
771 num_gabs = sctp_tsnmap_num_gabs(map, gabs);
772 num_dup_tsns = sctp_tsnmap_num_dups(map);
773
774 /* Initialize the SACK header. */
775 sack.cum_tsn_ack = htonl(ctsn);
776 sack.a_rwnd = htonl(asoc->a_rwnd);
777 sack.num_gap_ack_blocks = htons(num_gabs);
778 sack.num_dup_tsns = htons(num_dup_tsns);
779
780 len = sizeof(sack)
781 + sizeof(struct sctp_gap_ack_block) * num_gabs
782 + sizeof(__u32) * num_dup_tsns;
783
784 /* Create the chunk. */
785 retval = sctp_make_control(asoc, SCTP_CID_SACK, 0, len, GFP_ATOMIC);
786 if (!retval)
787 goto nodata;
788
789 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
790 *
791 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
792 * HEARTBEAT ACK, etc.) to the same destination transport
793 * address from which it received the DATA or control chunk to
794 * which it is replying. This rule should also be followed if
795 * the endpoint is bundling DATA chunks together with the
796 * reply chunk.
797 *
798 * However, when acknowledging multiple DATA chunks received
799 * in packets from different source addresses in a single
800 * SACK, the SACK chunk may be transmitted to one of the
801 * destination transport addresses from which the DATA or
802 * control chunks being acknowledged were received.
803 *
804 * [BUG: We do not implement the following paragraph.
805 * Perhaps we should remember the last transport we used for a
806 * SACK and avoid that (if possible) if we have seen any
807 * duplicates. --piggy]
808 *
809 * When a receiver of a duplicate DATA chunk sends a SACK to a
810 * multi- homed endpoint it MAY be beneficial to vary the
811 * destination address and not use the source address of the
812 * DATA chunk. The reason being that receiving a duplicate
813 * from a multi-homed endpoint might indicate that the return
814 * path (as specified in the source address of the DATA chunk)
815 * for the SACK is broken.
816 *
817 * [Send to the address from which we last received a DATA chunk.]
818 */
819 retval->transport = asoc->peer.last_data_from;
820
821 retval->subh.sack_hdr =
822 sctp_addto_chunk(retval, sizeof(sack), &sack);
823
824 /* Add the gap ack block information. */
825 if (num_gabs)
826 sctp_addto_chunk(retval, sizeof(__u32) * num_gabs,
827 gabs);
828
829 /* Add the duplicate TSN information. */
830 if (num_dup_tsns) {
831 asoc->stats.idupchunks += num_dup_tsns;
832 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns,
833 sctp_tsnmap_get_dups(map));
834 }
835 /* Once we have a sack generated, check to see what our sack
836 * generation is, if its 0, reset the transports to 0, and reset
837 * the association generation to 1
838 *
839 * The idea is that zero is never used as a valid generation for the
840 * association so no transport will match after a wrap event like this,
841 * Until the next sack
842 */
843 if (++asoc->peer.sack_generation == 0) {
844 list_for_each_entry(trans, &asoc->peer.transport_addr_list,
845 transports)
846 trans->sack_generation = 0;
847 asoc->peer.sack_generation = 1;
848 }
849nodata:
850 return retval;
851}
852
853/* Make a SHUTDOWN chunk. */
854struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc,
855 const struct sctp_chunk *chunk)
856{
857 struct sctp_shutdownhdr shut;
858 struct sctp_chunk *retval;
859 __u32 ctsn;
860
861 if (chunk && chunk->asoc)
862 ctsn = sctp_tsnmap_get_ctsn(&chunk->asoc->peer.tsn_map);
863 else
864 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
865
866 shut.cum_tsn_ack = htonl(ctsn);
867
868 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN, 0,
869 sizeof(shut), GFP_ATOMIC);
870 if (!retval)
871 goto nodata;
872
873 retval->subh.shutdown_hdr =
874 sctp_addto_chunk(retval, sizeof(shut), &shut);
875
876 if (chunk)
877 retval->transport = chunk->transport;
878nodata:
879 return retval;
880}
881
882struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc,
883 const struct sctp_chunk *chunk)
884{
885 struct sctp_chunk *retval;
886
887 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0,
888 GFP_ATOMIC);
889
890 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
891 *
892 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
893 * HEARTBEAT ACK, * etc.) to the same destination transport
894 * address from which it * received the DATA or control chunk
895 * to which it is replying.
896 *
897 * [ACK back to where the SHUTDOWN came from.]
898 */
899 if (retval && chunk)
900 retval->transport = chunk->transport;
901
902 return retval;
903}
904
905struct sctp_chunk *sctp_make_shutdown_complete(
906 const struct sctp_association *asoc,
907 const struct sctp_chunk *chunk)
908{
909 struct sctp_chunk *retval;
910 __u8 flags = 0;
911
912 /* Set the T-bit if we have no association (vtag will be
913 * reflected)
914 */
915 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T;
916
917 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags,
918 0, GFP_ATOMIC);
919
920 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
921 *
922 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
923 * HEARTBEAT ACK, * etc.) to the same destination transport
924 * address from which it * received the DATA or control chunk
925 * to which it is replying.
926 *
927 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK
928 * came from.]
929 */
930 if (retval && chunk)
931 retval->transport = chunk->transport;
932
933 return retval;
934}
935
936/* Create an ABORT. Note that we set the T bit if we have no
937 * association, except when responding to an INIT (sctpimpguide 2.41).
938 */
939struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc,
940 const struct sctp_chunk *chunk,
941 const size_t hint)
942{
943 struct sctp_chunk *retval;
944 __u8 flags = 0;
945
946 /* Set the T-bit if we have no association and 'chunk' is not
947 * an INIT (vtag will be reflected).
948 */
949 if (!asoc) {
950 if (chunk && chunk->chunk_hdr &&
951 chunk->chunk_hdr->type == SCTP_CID_INIT)
952 flags = 0;
953 else
954 flags = SCTP_CHUNK_FLAG_T;
955 }
956
957 retval = sctp_make_control(asoc, SCTP_CID_ABORT, flags, hint,
958 GFP_ATOMIC);
959
960 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
961 *
962 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
963 * HEARTBEAT ACK, * etc.) to the same destination transport
964 * address from which it * received the DATA or control chunk
965 * to which it is replying.
966 *
967 * [ABORT back to where the offender came from.]
968 */
969 if (retval && chunk)
970 retval->transport = chunk->transport;
971
972 return retval;
973}
974
975/* Helper to create ABORT with a NO_USER_DATA error. */
976struct sctp_chunk *sctp_make_abort_no_data(
977 const struct sctp_association *asoc,
978 const struct sctp_chunk *chunk,
979 __u32 tsn)
980{
981 struct sctp_chunk *retval;
982 __be32 payload;
983
984 retval = sctp_make_abort(asoc, chunk,
985 sizeof(struct sctp_errhdr) + sizeof(tsn));
986
987 if (!retval)
988 goto no_mem;
989
990 /* Put the tsn back into network byte order. */
991 payload = htonl(tsn);
992 sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload));
993 sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload);
994
995 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
996 *
997 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
998 * HEARTBEAT ACK, * etc.) to the same destination transport
999 * address from which it * received the DATA or control chunk
1000 * to which it is replying.
1001 *
1002 * [ABORT back to where the offender came from.]
1003 */
1004 if (chunk)
1005 retval->transport = chunk->transport;
1006
1007no_mem:
1008 return retval;
1009}
1010
1011/* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */
1012struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc,
1013 struct msghdr *msg,
1014 size_t paylen)
1015{
1016 struct sctp_chunk *retval;
1017 void *payload = NULL;
1018 int err;
1019
1020 retval = sctp_make_abort(asoc, NULL,
1021 sizeof(struct sctp_errhdr) + paylen);
1022 if (!retval)
1023 goto err_chunk;
1024
1025 if (paylen) {
1026 /* Put the msg_iov together into payload. */
1027 payload = kmalloc(paylen, GFP_KERNEL);
1028 if (!payload)
1029 goto err_payload;
1030
1031 err = memcpy_from_msg(payload, msg, paylen);
1032 if (err < 0)
1033 goto err_copy;
1034 }
1035
1036 sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen);
1037 sctp_addto_chunk(retval, paylen, payload);
1038
1039 if (paylen)
1040 kfree(payload);
1041
1042 return retval;
1043
1044err_copy:
1045 kfree(payload);
1046err_payload:
1047 sctp_chunk_free(retval);
1048 retval = NULL;
1049err_chunk:
1050 return retval;
1051}
1052
1053/* Append bytes to the end of a parameter. Will panic if chunk is not big
1054 * enough.
1055 */
1056static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
1057 const void *data)
1058{
1059 int chunklen = ntohs(chunk->chunk_hdr->length);
1060 void *target;
1061
1062 target = skb_put(chunk->skb, len);
1063
1064 if (data)
1065 memcpy(target, data, len);
1066 else
1067 memset(target, 0, len);
1068
1069 /* Adjust the chunk length field. */
1070 chunk->chunk_hdr->length = htons(chunklen + len);
1071 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1072
1073 return target;
1074}
1075
1076/* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */
1077struct sctp_chunk *sctp_make_abort_violation(
1078 const struct sctp_association *asoc,
1079 const struct sctp_chunk *chunk,
1080 const __u8 *payload,
1081 const size_t paylen)
1082{
1083 struct sctp_chunk *retval;
1084 struct sctp_paramhdr phdr;
1085
1086 retval = sctp_make_abort(asoc, chunk, sizeof(struct sctp_errhdr) +
1087 paylen + sizeof(phdr));
1088 if (!retval)
1089 goto end;
1090
1091 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen +
1092 sizeof(phdr));
1093
1094 phdr.type = htons(chunk->chunk_hdr->type);
1095 phdr.length = chunk->chunk_hdr->length;
1096 sctp_addto_chunk(retval, paylen, payload);
1097 sctp_addto_param(retval, sizeof(phdr), &phdr);
1098
1099end:
1100 return retval;
1101}
1102
1103struct sctp_chunk *sctp_make_violation_paramlen(
1104 const struct sctp_association *asoc,
1105 const struct sctp_chunk *chunk,
1106 struct sctp_paramhdr *param)
1107{
1108 static const char error[] = "The following parameter had invalid length:";
1109 size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr) +
1110 sizeof(*param);
1111 struct sctp_chunk *retval;
1112
1113 retval = sctp_make_abort(asoc, chunk, payload_len);
1114 if (!retval)
1115 goto nodata;
1116
1117 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION,
1118 sizeof(error) + sizeof(*param));
1119 sctp_addto_chunk(retval, sizeof(error), error);
1120 sctp_addto_param(retval, sizeof(*param), param);
1121
1122nodata:
1123 return retval;
1124}
1125
1126struct sctp_chunk *sctp_make_violation_max_retrans(
1127 const struct sctp_association *asoc,
1128 const struct sctp_chunk *chunk)
1129{
1130 static const char error[] = "Association exceeded its max_retrans count";
1131 size_t payload_len = sizeof(error) + sizeof(struct sctp_errhdr);
1132 struct sctp_chunk *retval;
1133
1134 retval = sctp_make_abort(asoc, chunk, payload_len);
1135 if (!retval)
1136 goto nodata;
1137
1138 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error));
1139 sctp_addto_chunk(retval, sizeof(error), error);
1140
1141nodata:
1142 return retval;
1143}
1144
1145/* Make a HEARTBEAT chunk. */
1146struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc,
1147 const struct sctp_transport *transport)
1148{
1149 struct sctp_sender_hb_info hbinfo;
1150 struct sctp_chunk *retval;
1151
1152 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT, 0,
1153 sizeof(hbinfo), GFP_ATOMIC);
1154
1155 if (!retval)
1156 goto nodata;
1157
1158 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO;
1159 hbinfo.param_hdr.length = htons(sizeof(hbinfo));
1160 hbinfo.daddr = transport->ipaddr;
1161 hbinfo.sent_at = jiffies;
1162 hbinfo.hb_nonce = transport->hb_nonce;
1163
1164 /* Cast away the 'const', as this is just telling the chunk
1165 * what transport it belongs to.
1166 */
1167 retval->transport = (struct sctp_transport *) transport;
1168 retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo),
1169 &hbinfo);
1170
1171nodata:
1172 return retval;
1173}
1174
1175struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc,
1176 const struct sctp_chunk *chunk,
1177 const void *payload,
1178 const size_t paylen)
1179{
1180 struct sctp_chunk *retval;
1181
1182 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen,
1183 GFP_ATOMIC);
1184 if (!retval)
1185 goto nodata;
1186
1187 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload);
1188
1189 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
1190 *
1191 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1192 * HEARTBEAT ACK, * etc.) to the same destination transport
1193 * address from which it * received the DATA or control chunk
1194 * to which it is replying.
1195 *
1196 * [HBACK back to where the HEARTBEAT came from.]
1197 */
1198 if (chunk)
1199 retval->transport = chunk->transport;
1200
1201nodata:
1202 return retval;
1203}
1204
1205/* Create an Operation Error chunk with the specified space reserved.
1206 * This routine can be used for containing multiple causes in the chunk.
1207 */
1208static struct sctp_chunk *sctp_make_op_error_space(
1209 const struct sctp_association *asoc,
1210 const struct sctp_chunk *chunk,
1211 size_t size)
1212{
1213 struct sctp_chunk *retval;
1214
1215 retval = sctp_make_control(asoc, SCTP_CID_ERROR, 0,
1216 sizeof(struct sctp_errhdr) + size,
1217 GFP_ATOMIC);
1218 if (!retval)
1219 goto nodata;
1220
1221 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
1222 *
1223 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1224 * HEARTBEAT ACK, etc.) to the same destination transport
1225 * address from which it received the DATA or control chunk
1226 * to which it is replying.
1227 *
1228 */
1229 if (chunk)
1230 retval->transport = chunk->transport;
1231
1232nodata:
1233 return retval;
1234}
1235
1236/* Create an Operation Error chunk of a fixed size, specifically,
1237 * min(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT) - overheads.
1238 * This is a helper function to allocate an error chunk for for those
1239 * invalid parameter codes in which we may not want to report all the
1240 * errors, if the incoming chunk is large. If it can't fit in a single
1241 * packet, we ignore it.
1242 */
1243static inline struct sctp_chunk *sctp_make_op_error_limited(
1244 const struct sctp_association *asoc,
1245 const struct sctp_chunk *chunk)
1246{
1247 size_t size = SCTP_DEFAULT_MAXSEGMENT;
1248 struct sctp_sock *sp = NULL;
1249
1250 if (asoc) {
1251 size = min_t(size_t, size, asoc->pathmtu);
1252 sp = sctp_sk(asoc->base.sk);
1253 }
1254
1255 size = sctp_mtu_payload(sp, size, sizeof(struct sctp_errhdr));
1256
1257 return sctp_make_op_error_space(asoc, chunk, size);
1258}
1259
1260/* Create an Operation Error chunk. */
1261struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc,
1262 const struct sctp_chunk *chunk,
1263 __be16 cause_code, const void *payload,
1264 size_t paylen, size_t reserve_tail)
1265{
1266 struct sctp_chunk *retval;
1267
1268 retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail);
1269 if (!retval)
1270 goto nodata;
1271
1272 sctp_init_cause(retval, cause_code, paylen + reserve_tail);
1273 sctp_addto_chunk(retval, paylen, payload);
1274 if (reserve_tail)
1275 sctp_addto_param(retval, reserve_tail, NULL);
1276
1277nodata:
1278 return retval;
1279}
1280
1281struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc,
1282 __u16 key_id)
1283{
1284 struct sctp_authhdr auth_hdr;
1285 struct sctp_hmac *hmac_desc;
1286 struct sctp_chunk *retval;
1287
1288 /* Get the first hmac that the peer told us to use */
1289 hmac_desc = sctp_auth_asoc_get_hmac(asoc);
1290 if (unlikely(!hmac_desc))
1291 return NULL;
1292
1293 retval = sctp_make_control(asoc, SCTP_CID_AUTH, 0,
1294 hmac_desc->hmac_len + sizeof(auth_hdr),
1295 GFP_ATOMIC);
1296 if (!retval)
1297 return NULL;
1298
1299 auth_hdr.hmac_id = htons(hmac_desc->hmac_id);
1300 auth_hdr.shkey_id = htons(key_id);
1301
1302 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(auth_hdr),
1303 &auth_hdr);
1304
1305 skb_put_zero(retval->skb, hmac_desc->hmac_len);
1306
1307 /* Adjust the chunk header to include the empty MAC */
1308 retval->chunk_hdr->length =
1309 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len);
1310 retval->chunk_end = skb_tail_pointer(retval->skb);
1311
1312 return retval;
1313}
1314
1315
1316/********************************************************************
1317 * 2nd Level Abstractions
1318 ********************************************************************/
1319
1320/* Turn an skb into a chunk.
1321 * FIXME: Eventually move the structure directly inside the skb->cb[].
1322 *
1323 * sctpimpguide-05.txt Section 2.8.2
1324 * M1) Each time a new DATA chunk is transmitted
1325 * set the 'TSN.Missing.Report' count for that TSN to 0. The
1326 * 'TSN.Missing.Report' count will be used to determine missing chunks
1327 * and when to fast retransmit.
1328 *
1329 */
1330struct sctp_chunk *sctp_chunkify(struct sk_buff *skb,
1331 const struct sctp_association *asoc,
1332 struct sock *sk, gfp_t gfp)
1333{
1334 struct sctp_chunk *retval;
1335
1336 retval = kmem_cache_zalloc(sctp_chunk_cachep, gfp);
1337
1338 if (!retval)
1339 goto nodata;
1340 if (!sk)
1341 pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb);
1342
1343 INIT_LIST_HEAD(&retval->list);
1344 retval->skb = skb;
1345 retval->asoc = (struct sctp_association *)asoc;
1346 retval->singleton = 1;
1347
1348 retval->fast_retransmit = SCTP_CAN_FRTX;
1349
1350 /* Polish the bead hole. */
1351 INIT_LIST_HEAD(&retval->transmitted_list);
1352 INIT_LIST_HEAD(&retval->frag_list);
1353 SCTP_DBG_OBJCNT_INC(chunk);
1354 refcount_set(&retval->refcnt, 1);
1355
1356nodata:
1357 return retval;
1358}
1359
1360/* Set chunk->source and dest based on the IP header in chunk->skb. */
1361void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src,
1362 union sctp_addr *dest)
1363{
1364 memcpy(&chunk->source, src, sizeof(union sctp_addr));
1365 memcpy(&chunk->dest, dest, sizeof(union sctp_addr));
1366}
1367
1368/* Extract the source address from a chunk. */
1369const union sctp_addr *sctp_source(const struct sctp_chunk *chunk)
1370{
1371 /* If we have a known transport, use that. */
1372 if (chunk->transport) {
1373 return &chunk->transport->ipaddr;
1374 } else {
1375 /* Otherwise, extract it from the IP header. */
1376 return &chunk->source;
1377 }
1378}
1379
1380/* Create a new chunk, setting the type and flags headers from the
1381 * arguments, reserving enough space for a 'paylen' byte payload.
1382 */
1383static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc,
1384 __u8 type, __u8 flags, int paylen,
1385 gfp_t gfp)
1386{
1387 struct sctp_chunkhdr *chunk_hdr;
1388 struct sctp_chunk *retval;
1389 struct sk_buff *skb;
1390 struct sock *sk;
1391 int chunklen;
1392
1393 chunklen = SCTP_PAD4(sizeof(*chunk_hdr) + paylen);
1394 if (chunklen > SCTP_MAX_CHUNK_LEN)
1395 goto nodata;
1396
1397 /* No need to allocate LL here, as this is only a chunk. */
1398 skb = alloc_skb(chunklen, gfp);
1399 if (!skb)
1400 goto nodata;
1401
1402 /* Make room for the chunk header. */
1403 chunk_hdr = (struct sctp_chunkhdr *)skb_put(skb, sizeof(*chunk_hdr));
1404 chunk_hdr->type = type;
1405 chunk_hdr->flags = flags;
1406 chunk_hdr->length = htons(sizeof(*chunk_hdr));
1407
1408 sk = asoc ? asoc->base.sk : NULL;
1409 retval = sctp_chunkify(skb, asoc, sk, gfp);
1410 if (!retval) {
1411 kfree_skb(skb);
1412 goto nodata;
1413 }
1414
1415 retval->chunk_hdr = chunk_hdr;
1416 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(*chunk_hdr);
1417
1418 /* Determine if the chunk needs to be authenticated */
1419 if (sctp_auth_send_cid(type, asoc))
1420 retval->auth = 1;
1421
1422 return retval;
1423nodata:
1424 return NULL;
1425}
1426
1427static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc,
1428 __u8 flags, int paylen, gfp_t gfp)
1429{
1430 return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen, gfp);
1431}
1432
1433struct sctp_chunk *sctp_make_idata(const struct sctp_association *asoc,
1434 __u8 flags, int paylen, gfp_t gfp)
1435{
1436 return _sctp_make_chunk(asoc, SCTP_CID_I_DATA, flags, paylen, gfp);
1437}
1438
1439static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc,
1440 __u8 type, __u8 flags, int paylen,
1441 gfp_t gfp)
1442{
1443 struct sctp_chunk *chunk;
1444
1445 chunk = _sctp_make_chunk(asoc, type, flags, paylen, gfp);
1446 if (chunk)
1447 sctp_control_set_owner_w(chunk);
1448
1449 return chunk;
1450}
1451
1452/* Release the memory occupied by a chunk. */
1453static void sctp_chunk_destroy(struct sctp_chunk *chunk)
1454{
1455 BUG_ON(!list_empty(&chunk->list));
1456 list_del_init(&chunk->transmitted_list);
1457
1458 consume_skb(chunk->skb);
1459 consume_skb(chunk->auth_chunk);
1460
1461 SCTP_DBG_OBJCNT_DEC(chunk);
1462 kmem_cache_free(sctp_chunk_cachep, chunk);
1463}
1464
1465/* Possibly, free the chunk. */
1466void sctp_chunk_free(struct sctp_chunk *chunk)
1467{
1468 /* Release our reference on the message tracker. */
1469 if (chunk->msg)
1470 sctp_datamsg_put(chunk->msg);
1471
1472 sctp_chunk_put(chunk);
1473}
1474
1475/* Grab a reference to the chunk. */
1476void sctp_chunk_hold(struct sctp_chunk *ch)
1477{
1478 refcount_inc(&ch->refcnt);
1479}
1480
1481/* Release a reference to the chunk. */
1482void sctp_chunk_put(struct sctp_chunk *ch)
1483{
1484 if (refcount_dec_and_test(&ch->refcnt))
1485 sctp_chunk_destroy(ch);
1486}
1487
1488/* Append bytes to the end of a chunk. Will panic if chunk is not big
1489 * enough.
1490 */
1491void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data)
1492{
1493 int chunklen = ntohs(chunk->chunk_hdr->length);
1494 int padlen = SCTP_PAD4(chunklen) - chunklen;
1495 void *target;
1496
1497 skb_put_zero(chunk->skb, padlen);
1498 target = skb_put_data(chunk->skb, data, len);
1499
1500 /* Adjust the chunk length field. */
1501 chunk->chunk_hdr->length = htons(chunklen + padlen + len);
1502 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1503
1504 return target;
1505}
1506
1507/* Append bytes from user space to the end of a chunk. Will panic if
1508 * chunk is not big enough.
1509 * Returns a kernel err value.
1510 */
1511int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
1512 struct iov_iter *from)
1513{
1514 void *target;
1515
1516 /* Make room in chunk for data. */
1517 target = skb_put(chunk->skb, len);
1518
1519 /* Copy data (whole iovec) into chunk */
1520 if (!copy_from_iter_full(target, len, from))
1521 return -EFAULT;
1522
1523 /* Adjust the chunk length field. */
1524 chunk->chunk_hdr->length =
1525 htons(ntohs(chunk->chunk_hdr->length) + len);
1526 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1527
1528 return 0;
1529}
1530
1531/* Helper function to assign a TSN if needed. This assumes that both
1532 * the data_hdr and association have already been assigned.
1533 */
1534void sctp_chunk_assign_ssn(struct sctp_chunk *chunk)
1535{
1536 struct sctp_stream *stream;
1537 struct sctp_chunk *lchunk;
1538 struct sctp_datamsg *msg;
1539 __u16 ssn, sid;
1540
1541 if (chunk->has_ssn)
1542 return;
1543
1544 /* All fragments will be on the same stream */
1545 sid = ntohs(chunk->subh.data_hdr->stream);
1546 stream = &chunk->asoc->stream;
1547
1548 /* Now assign the sequence number to the entire message.
1549 * All fragments must have the same stream sequence number.
1550 */
1551 msg = chunk->msg;
1552 list_for_each_entry(lchunk, &msg->chunks, frag_list) {
1553 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
1554 ssn = 0;
1555 } else {
1556 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG)
1557 ssn = sctp_ssn_next(stream, out, sid);
1558 else
1559 ssn = sctp_ssn_peek(stream, out, sid);
1560 }
1561
1562 lchunk->subh.data_hdr->ssn = htons(ssn);
1563 lchunk->has_ssn = 1;
1564 }
1565}
1566
1567/* Helper function to assign a TSN if needed. This assumes that both
1568 * the data_hdr and association have already been assigned.
1569 */
1570void sctp_chunk_assign_tsn(struct sctp_chunk *chunk)
1571{
1572 if (!chunk->has_tsn) {
1573 /* This is the last possible instant to
1574 * assign a TSN.
1575 */
1576 chunk->subh.data_hdr->tsn =
1577 htonl(sctp_association_get_next_tsn(chunk->asoc));
1578 chunk->has_tsn = 1;
1579 }
1580}
1581
1582/* Create a CLOSED association to use with an incoming packet. */
1583struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep,
1584 struct sctp_chunk *chunk,
1585 gfp_t gfp)
1586{
1587 struct sctp_association *asoc;
1588 enum sctp_scope scope;
1589 struct sk_buff *skb;
1590
1591 /* Create the bare association. */
1592 scope = sctp_scope(sctp_source(chunk));
1593 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp);
1594 if (!asoc)
1595 goto nodata;
1596 asoc->temp = 1;
1597 skb = chunk->skb;
1598 /* Create an entry for the source address of the packet. */
1599 SCTP_INPUT_CB(skb)->af->from_skb(&asoc->c.peer_addr, skb, 1);
1600
1601nodata:
1602 return asoc;
1603}
1604
1605/* Build a cookie representing asoc.
1606 * This INCLUDES the param header needed to put the cookie in the INIT ACK.
1607 */
1608static struct sctp_cookie_param *sctp_pack_cookie(
1609 const struct sctp_endpoint *ep,
1610 const struct sctp_association *asoc,
1611 const struct sctp_chunk *init_chunk,
1612 int *cookie_len, const __u8 *raw_addrs,
1613 int addrs_len)
1614{
1615 struct sctp_signed_cookie *cookie;
1616 struct sctp_cookie_param *retval;
1617 int headersize, bodysize;
1618
1619 /* Header size is static data prior to the actual cookie, including
1620 * any padding.
1621 */
1622 headersize = sizeof(struct sctp_paramhdr) +
1623 (sizeof(struct sctp_signed_cookie) -
1624 sizeof(struct sctp_cookie));
1625 bodysize = sizeof(struct sctp_cookie)
1626 + ntohs(init_chunk->chunk_hdr->length) + addrs_len;
1627
1628 /* Pad out the cookie to a multiple to make the signature
1629 * functions simpler to write.
1630 */
1631 if (bodysize % SCTP_COOKIE_MULTIPLE)
1632 bodysize += SCTP_COOKIE_MULTIPLE
1633 - (bodysize % SCTP_COOKIE_MULTIPLE);
1634 *cookie_len = headersize + bodysize;
1635
1636 /* Clear this memory since we are sending this data structure
1637 * out on the network.
1638 */
1639 retval = kzalloc(*cookie_len, GFP_ATOMIC);
1640 if (!retval)
1641 goto nodata;
1642
1643 cookie = (struct sctp_signed_cookie *) retval->body;
1644
1645 /* Set up the parameter header. */
1646 retval->p.type = SCTP_PARAM_STATE_COOKIE;
1647 retval->p.length = htons(*cookie_len);
1648
1649 /* Copy the cookie part of the association itself. */
1650 cookie->c = asoc->c;
1651 /* Save the raw address list length in the cookie. */
1652 cookie->c.raw_addr_list_len = addrs_len;
1653
1654 /* Remember PR-SCTP capability. */
1655 cookie->c.prsctp_capable = asoc->peer.prsctp_capable;
1656
1657 /* Save adaptation indication in the cookie. */
1658 cookie->c.adaptation_ind = asoc->peer.adaptation_ind;
1659
1660 /* Set an expiration time for the cookie. */
1661 cookie->c.expiration = ktime_add(asoc->cookie_life,
1662 ktime_get_real());
1663
1664 /* Copy the peer's init packet. */
1665 memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr,
1666 ntohs(init_chunk->chunk_hdr->length));
1667
1668 /* Copy the raw local address list of the association. */
1669 memcpy((__u8 *)&cookie->c.peer_init[0] +
1670 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len);
1671
1672 if (sctp_sk(ep->base.sk)->hmac) {
1673 struct crypto_shash *tfm = sctp_sk(ep->base.sk)->hmac;
1674 int err;
1675
1676 /* Sign the message. */
1677 err = crypto_shash_setkey(tfm, ep->secret_key,
1678 sizeof(ep->secret_key)) ?:
1679 crypto_shash_tfm_digest(tfm, (u8 *)&cookie->c, bodysize,
1680 cookie->signature);
1681 if (err)
1682 goto free_cookie;
1683 }
1684
1685 return retval;
1686
1687free_cookie:
1688 kfree(retval);
1689nodata:
1690 *cookie_len = 0;
1691 return NULL;
1692}
1693
1694/* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */
1695struct sctp_association *sctp_unpack_cookie(
1696 const struct sctp_endpoint *ep,
1697 const struct sctp_association *asoc,
1698 struct sctp_chunk *chunk, gfp_t gfp,
1699 int *error, struct sctp_chunk **errp)
1700{
1701 struct sctp_association *retval = NULL;
1702 int headersize, bodysize, fixed_size;
1703 struct sctp_signed_cookie *cookie;
1704 struct sk_buff *skb = chunk->skb;
1705 struct sctp_cookie *bear_cookie;
1706 __u8 *digest = ep->digest;
1707 enum sctp_scope scope;
1708 unsigned int len;
1709 ktime_t kt;
1710
1711 /* Header size is static data prior to the actual cookie, including
1712 * any padding.
1713 */
1714 headersize = sizeof(struct sctp_chunkhdr) +
1715 (sizeof(struct sctp_signed_cookie) -
1716 sizeof(struct sctp_cookie));
1717 bodysize = ntohs(chunk->chunk_hdr->length) - headersize;
1718 fixed_size = headersize + sizeof(struct sctp_cookie);
1719
1720 /* Verify that the chunk looks like it even has a cookie.
1721 * There must be enough room for our cookie and our peer's
1722 * INIT chunk.
1723 */
1724 len = ntohs(chunk->chunk_hdr->length);
1725 if (len < fixed_size + sizeof(struct sctp_chunkhdr))
1726 goto malformed;
1727
1728 /* Verify that the cookie has been padded out. */
1729 if (bodysize % SCTP_COOKIE_MULTIPLE)
1730 goto malformed;
1731
1732 /* Process the cookie. */
1733 cookie = chunk->subh.cookie_hdr;
1734 bear_cookie = &cookie->c;
1735
1736 if (!sctp_sk(ep->base.sk)->hmac)
1737 goto no_hmac;
1738
1739 /* Check the signature. */
1740 {
1741 struct crypto_shash *tfm = sctp_sk(ep->base.sk)->hmac;
1742 int err;
1743
1744 err = crypto_shash_setkey(tfm, ep->secret_key,
1745 sizeof(ep->secret_key)) ?:
1746 crypto_shash_tfm_digest(tfm, (u8 *)bear_cookie, bodysize,
1747 digest);
1748 if (err) {
1749 *error = -SCTP_IERROR_NOMEM;
1750 goto fail;
1751 }
1752 }
1753
1754 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
1755 *error = -SCTP_IERROR_BAD_SIG;
1756 goto fail;
1757 }
1758
1759no_hmac:
1760 /* IG Section 2.35.2:
1761 * 3) Compare the port numbers and the verification tag contained
1762 * within the COOKIE ECHO chunk to the actual port numbers and the
1763 * verification tag within the SCTP common header of the received
1764 * packet. If these values do not match the packet MUST be silently
1765 * discarded,
1766 */
1767 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) {
1768 *error = -SCTP_IERROR_BAD_TAG;
1769 goto fail;
1770 }
1771
1772 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port ||
1773 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) {
1774 *error = -SCTP_IERROR_BAD_PORTS;
1775 goto fail;
1776 }
1777
1778 /* Check to see if the cookie is stale. If there is already
1779 * an association, there is no need to check cookie's expiration
1780 * for init collision case of lost COOKIE ACK.
1781 * If skb has been timestamped, then use the stamp, otherwise
1782 * use current time. This introduces a small possibility that
1783 * that a cookie may be considered expired, but his would only slow
1784 * down the new association establishment instead of every packet.
1785 */
1786 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP))
1787 kt = skb_get_ktime(skb);
1788 else
1789 kt = ktime_get_real();
1790
1791 if (!asoc && ktime_before(bear_cookie->expiration, kt)) {
1792 suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration));
1793 __be32 n = htonl(usecs);
1794
1795 /*
1796 * Section 3.3.10.3 Stale Cookie Error (3)
1797 *
1798 * Cause of error
1799 * ---------------
1800 * Stale Cookie Error: Indicates the receipt of a valid State
1801 * Cookie that has expired.
1802 */
1803 *errp = sctp_make_op_error(asoc, chunk,
1804 SCTP_ERROR_STALE_COOKIE, &n,
1805 sizeof(n), 0);
1806 if (*errp)
1807 *error = -SCTP_IERROR_STALE_COOKIE;
1808 else
1809 *error = -SCTP_IERROR_NOMEM;
1810
1811 goto fail;
1812 }
1813
1814 /* Make a new base association. */
1815 scope = sctp_scope(sctp_source(chunk));
1816 retval = sctp_association_new(ep, ep->base.sk, scope, gfp);
1817 if (!retval) {
1818 *error = -SCTP_IERROR_NOMEM;
1819 goto fail;
1820 }
1821
1822 /* Set up our peer's port number. */
1823 retval->peer.port = ntohs(chunk->sctp_hdr->source);
1824
1825 /* Populate the association from the cookie. */
1826 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie));
1827
1828 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie,
1829 GFP_ATOMIC) < 0) {
1830 *error = -SCTP_IERROR_NOMEM;
1831 goto fail;
1832 }
1833
1834 /* Also, add the destination address. */
1835 if (list_empty(&retval->base.bind_addr.address_list)) {
1836 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest,
1837 sizeof(chunk->dest), SCTP_ADDR_SRC,
1838 GFP_ATOMIC);
1839 }
1840
1841 retval->next_tsn = retval->c.initial_tsn;
1842 retval->ctsn_ack_point = retval->next_tsn - 1;
1843 retval->addip_serial = retval->c.initial_tsn;
1844 retval->strreset_outseq = retval->c.initial_tsn;
1845 retval->adv_peer_ack_point = retval->ctsn_ack_point;
1846 retval->peer.prsctp_capable = retval->c.prsctp_capable;
1847 retval->peer.adaptation_ind = retval->c.adaptation_ind;
1848
1849 /* The INIT stuff will be done by the side effects. */
1850 return retval;
1851
1852fail:
1853 if (retval)
1854 sctp_association_free(retval);
1855
1856 return NULL;
1857
1858malformed:
1859 /* Yikes! The packet is either corrupt or deliberately
1860 * malformed.
1861 */
1862 *error = -SCTP_IERROR_MALFORMED;
1863 goto fail;
1864}
1865
1866/********************************************************************
1867 * 3rd Level Abstractions
1868 ********************************************************************/
1869
1870struct __sctp_missing {
1871 __be32 num_missing;
1872 __be16 type;
1873} __packed;
1874
1875/*
1876 * Report a missing mandatory parameter.
1877 */
1878static int sctp_process_missing_param(const struct sctp_association *asoc,
1879 enum sctp_param paramtype,
1880 struct sctp_chunk *chunk,
1881 struct sctp_chunk **errp)
1882{
1883 struct __sctp_missing report;
1884 __u16 len;
1885
1886 len = SCTP_PAD4(sizeof(report));
1887
1888 /* Make an ERROR chunk, preparing enough room for
1889 * returning multiple unknown parameters.
1890 */
1891 if (!*errp)
1892 *errp = sctp_make_op_error_space(asoc, chunk, len);
1893
1894 if (*errp) {
1895 report.num_missing = htonl(1);
1896 report.type = paramtype;
1897 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM,
1898 sizeof(report));
1899 sctp_addto_chunk(*errp, sizeof(report), &report);
1900 }
1901
1902 /* Stop processing this chunk. */
1903 return 0;
1904}
1905
1906/* Report an Invalid Mandatory Parameter. */
1907static int sctp_process_inv_mandatory(const struct sctp_association *asoc,
1908 struct sctp_chunk *chunk,
1909 struct sctp_chunk **errp)
1910{
1911 /* Invalid Mandatory Parameter Error has no payload. */
1912
1913 if (!*errp)
1914 *errp = sctp_make_op_error_space(asoc, chunk, 0);
1915
1916 if (*errp)
1917 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0);
1918
1919 /* Stop processing this chunk. */
1920 return 0;
1921}
1922
1923static int sctp_process_inv_paramlength(const struct sctp_association *asoc,
1924 struct sctp_paramhdr *param,
1925 const struct sctp_chunk *chunk,
1926 struct sctp_chunk **errp)
1927{
1928 /* This is a fatal error. Any accumulated non-fatal errors are
1929 * not reported.
1930 */
1931 if (*errp)
1932 sctp_chunk_free(*errp);
1933
1934 /* Create an error chunk and fill it in with our payload. */
1935 *errp = sctp_make_violation_paramlen(asoc, chunk, param);
1936
1937 return 0;
1938}
1939
1940
1941/* Do not attempt to handle the HOST_NAME parm. However, do
1942 * send back an indicator to the peer.
1943 */
1944static int sctp_process_hn_param(const struct sctp_association *asoc,
1945 union sctp_params param,
1946 struct sctp_chunk *chunk,
1947 struct sctp_chunk **errp)
1948{
1949 __u16 len = ntohs(param.p->length);
1950
1951 /* Processing of the HOST_NAME parameter will generate an
1952 * ABORT. If we've accumulated any non-fatal errors, they
1953 * would be unrecognized parameters and we should not include
1954 * them in the ABORT.
1955 */
1956 if (*errp)
1957 sctp_chunk_free(*errp);
1958
1959 *errp = sctp_make_op_error(asoc, chunk, SCTP_ERROR_DNS_FAILED,
1960 param.v, len, 0);
1961
1962 /* Stop processing this chunk. */
1963 return 0;
1964}
1965
1966static int sctp_verify_ext_param(struct net *net,
1967 const struct sctp_endpoint *ep,
1968 union sctp_params param)
1969{
1970 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
1971 int have_asconf = 0;
1972 int have_auth = 0;
1973 int i;
1974
1975 for (i = 0; i < num_ext; i++) {
1976 switch (param.ext->chunks[i]) {
1977 case SCTP_CID_AUTH:
1978 have_auth = 1;
1979 break;
1980 case SCTP_CID_ASCONF:
1981 case SCTP_CID_ASCONF_ACK:
1982 have_asconf = 1;
1983 break;
1984 }
1985 }
1986
1987 /* ADD-IP Security: The draft requires us to ABORT or ignore the
1988 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this
1989 * only if ADD-IP is turned on and we are not backward-compatible
1990 * mode.
1991 */
1992 if (net->sctp.addip_noauth)
1993 return 1;
1994
1995 if (ep->asconf_enable && !have_auth && have_asconf)
1996 return 0;
1997
1998 return 1;
1999}
2000
2001static void sctp_process_ext_param(struct sctp_association *asoc,
2002 union sctp_params param)
2003{
2004 __u16 num_ext = ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
2005 int i;
2006
2007 for (i = 0; i < num_ext; i++) {
2008 switch (param.ext->chunks[i]) {
2009 case SCTP_CID_RECONF:
2010 if (asoc->ep->reconf_enable)
2011 asoc->peer.reconf_capable = 1;
2012 break;
2013 case SCTP_CID_FWD_TSN:
2014 if (asoc->ep->prsctp_enable)
2015 asoc->peer.prsctp_capable = 1;
2016 break;
2017 case SCTP_CID_AUTH:
2018 /* if the peer reports AUTH, assume that he
2019 * supports AUTH.
2020 */
2021 if (asoc->ep->auth_enable)
2022 asoc->peer.auth_capable = 1;
2023 break;
2024 case SCTP_CID_ASCONF:
2025 case SCTP_CID_ASCONF_ACK:
2026 if (asoc->ep->asconf_enable)
2027 asoc->peer.asconf_capable = 1;
2028 break;
2029 case SCTP_CID_I_DATA:
2030 if (asoc->ep->intl_enable)
2031 asoc->peer.intl_capable = 1;
2032 break;
2033 default:
2034 break;
2035 }
2036 }
2037}
2038
2039/* RFC 3.2.1 & the Implementers Guide 2.2.
2040 *
2041 * The Parameter Types are encoded such that the
2042 * highest-order two bits specify the action that must be
2043 * taken if the processing endpoint does not recognize the
2044 * Parameter Type.
2045 *
2046 * 00 - Stop processing this parameter; do not process any further
2047 * parameters within this chunk
2048 *
2049 * 01 - Stop processing this parameter, do not process any further
2050 * parameters within this chunk, and report the unrecognized
2051 * parameter in an 'Unrecognized Parameter' ERROR chunk.
2052 *
2053 * 10 - Skip this parameter and continue processing.
2054 *
2055 * 11 - Skip this parameter and continue processing but
2056 * report the unrecognized parameter in an
2057 * 'Unrecognized Parameter' ERROR chunk.
2058 *
2059 * Return value:
2060 * SCTP_IERROR_NO_ERROR - continue with the chunk
2061 * SCTP_IERROR_ERROR - stop and report an error.
2062 * SCTP_IERROR_NOMEME - out of memory.
2063 */
2064static enum sctp_ierror sctp_process_unk_param(
2065 const struct sctp_association *asoc,
2066 union sctp_params param,
2067 struct sctp_chunk *chunk,
2068 struct sctp_chunk **errp)
2069{
2070 int retval = SCTP_IERROR_NO_ERROR;
2071
2072 switch (param.p->type & SCTP_PARAM_ACTION_MASK) {
2073 case SCTP_PARAM_ACTION_DISCARD:
2074 retval = SCTP_IERROR_ERROR;
2075 break;
2076 case SCTP_PARAM_ACTION_SKIP:
2077 break;
2078 case SCTP_PARAM_ACTION_DISCARD_ERR:
2079 retval = SCTP_IERROR_ERROR;
2080 fallthrough;
2081 case SCTP_PARAM_ACTION_SKIP_ERR:
2082 /* Make an ERROR chunk, preparing enough room for
2083 * returning multiple unknown parameters.
2084 */
2085 if (!*errp) {
2086 *errp = sctp_make_op_error_limited(asoc, chunk);
2087 if (!*errp) {
2088 /* If there is no memory for generating the
2089 * ERROR report as specified, an ABORT will be
2090 * triggered to the peer and the association
2091 * won't be established.
2092 */
2093 retval = SCTP_IERROR_NOMEM;
2094 break;
2095 }
2096 }
2097
2098 if (!sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM,
2099 ntohs(param.p->length)))
2100 sctp_addto_chunk(*errp, ntohs(param.p->length),
2101 param.v);
2102 break;
2103 default:
2104 break;
2105 }
2106
2107 return retval;
2108}
2109
2110/* Verify variable length parameters
2111 * Return values:
2112 * SCTP_IERROR_ABORT - trigger an ABORT
2113 * SCTP_IERROR_NOMEM - out of memory (abort)
2114 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR
2115 * SCTP_IERROR_NO_ERROR - continue with the chunk
2116 */
2117static enum sctp_ierror sctp_verify_param(struct net *net,
2118 const struct sctp_endpoint *ep,
2119 const struct sctp_association *asoc,
2120 union sctp_params param,
2121 enum sctp_cid cid,
2122 struct sctp_chunk *chunk,
2123 struct sctp_chunk **err_chunk)
2124{
2125 struct sctp_hmac_algo_param *hmacs;
2126 int retval = SCTP_IERROR_NO_ERROR;
2127 __u16 n_elt, id = 0;
2128 int i;
2129
2130 /* FIXME - This routine is not looking at each parameter per the
2131 * chunk type, i.e., unrecognized parameters should be further
2132 * identified based on the chunk id.
2133 */
2134
2135 switch (param.p->type) {
2136 case SCTP_PARAM_IPV4_ADDRESS:
2137 case SCTP_PARAM_IPV6_ADDRESS:
2138 case SCTP_PARAM_COOKIE_PRESERVATIVE:
2139 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
2140 case SCTP_PARAM_STATE_COOKIE:
2141 case SCTP_PARAM_HEARTBEAT_INFO:
2142 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
2143 case SCTP_PARAM_ECN_CAPABLE:
2144 case SCTP_PARAM_ADAPTATION_LAYER_IND:
2145 break;
2146
2147 case SCTP_PARAM_SUPPORTED_EXT:
2148 if (!sctp_verify_ext_param(net, ep, param))
2149 return SCTP_IERROR_ABORT;
2150 break;
2151
2152 case SCTP_PARAM_SET_PRIMARY:
2153 if (ep->asconf_enable)
2154 break;
2155 goto unhandled;
2156
2157 case SCTP_PARAM_HOST_NAME_ADDRESS:
2158 /* Tell the peer, we won't support this param. */
2159 sctp_process_hn_param(asoc, param, chunk, err_chunk);
2160 retval = SCTP_IERROR_ABORT;
2161 break;
2162
2163 case SCTP_PARAM_FWD_TSN_SUPPORT:
2164 if (ep->prsctp_enable)
2165 break;
2166 goto unhandled;
2167
2168 case SCTP_PARAM_RANDOM:
2169 if (!ep->auth_enable)
2170 goto unhandled;
2171
2172 /* SCTP-AUTH: Secion 6.1
2173 * If the random number is not 32 byte long the association
2174 * MUST be aborted. The ABORT chunk SHOULD contain the error
2175 * cause 'Protocol Violation'.
2176 */
2177 if (SCTP_AUTH_RANDOM_LENGTH != ntohs(param.p->length) -
2178 sizeof(struct sctp_paramhdr)) {
2179 sctp_process_inv_paramlength(asoc, param.p,
2180 chunk, err_chunk);
2181 retval = SCTP_IERROR_ABORT;
2182 }
2183 break;
2184
2185 case SCTP_PARAM_CHUNKS:
2186 if (!ep->auth_enable)
2187 goto unhandled;
2188
2189 /* SCTP-AUTH: Section 3.2
2190 * The CHUNKS parameter MUST be included once in the INIT or
2191 * INIT-ACK chunk if the sender wants to receive authenticated
2192 * chunks. Its maximum length is 260 bytes.
2193 */
2194 if (260 < ntohs(param.p->length)) {
2195 sctp_process_inv_paramlength(asoc, param.p,
2196 chunk, err_chunk);
2197 retval = SCTP_IERROR_ABORT;
2198 }
2199 break;
2200
2201 case SCTP_PARAM_HMAC_ALGO:
2202 if (!ep->auth_enable)
2203 goto unhandled;
2204
2205 hmacs = (struct sctp_hmac_algo_param *)param.p;
2206 n_elt = (ntohs(param.p->length) -
2207 sizeof(struct sctp_paramhdr)) >> 1;
2208
2209 /* SCTP-AUTH: Section 6.1
2210 * The HMAC algorithm based on SHA-1 MUST be supported and
2211 * included in the HMAC-ALGO parameter.
2212 */
2213 for (i = 0; i < n_elt; i++) {
2214 id = ntohs(hmacs->hmac_ids[i]);
2215
2216 if (id == SCTP_AUTH_HMAC_ID_SHA1)
2217 break;
2218 }
2219
2220 if (id != SCTP_AUTH_HMAC_ID_SHA1) {
2221 sctp_process_inv_paramlength(asoc, param.p, chunk,
2222 err_chunk);
2223 retval = SCTP_IERROR_ABORT;
2224 }
2225 break;
2226unhandled:
2227 default:
2228 pr_debug("%s: unrecognized param:%d for chunk:%d\n",
2229 __func__, ntohs(param.p->type), cid);
2230
2231 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk);
2232 break;
2233 }
2234 return retval;
2235}
2236
2237/* Verify the INIT packet before we process it. */
2238int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
2239 const struct sctp_association *asoc, enum sctp_cid cid,
2240 struct sctp_init_chunk *peer_init,
2241 struct sctp_chunk *chunk, struct sctp_chunk **errp)
2242{
2243 union sctp_params param;
2244 bool has_cookie = false;
2245 int result;
2246
2247 /* Check for missing mandatory parameters. Note: Initial TSN is
2248 * also mandatory, but is not checked here since the valid range
2249 * is 0..2**32-1. RFC4960, section 3.3.3.
2250 */
2251 if (peer_init->init_hdr.num_outbound_streams == 0 ||
2252 peer_init->init_hdr.num_inbound_streams == 0 ||
2253 peer_init->init_hdr.init_tag == 0 ||
2254 ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW)
2255 return sctp_process_inv_mandatory(asoc, chunk, errp);
2256
2257 sctp_walk_params(param, peer_init, init_hdr.params) {
2258 if (param.p->type == SCTP_PARAM_STATE_COOKIE)
2259 has_cookie = true;
2260 }
2261
2262 /* There is a possibility that a parameter length was bad and
2263 * in that case we would have stoped walking the parameters.
2264 * The current param.p would point at the bad one.
2265 * Current consensus on the mailing list is to generate a PROTOCOL
2266 * VIOLATION error. We build the ERROR chunk here and let the normal
2267 * error handling code build and send the packet.
2268 */
2269 if (param.v != (void *)chunk->chunk_end)
2270 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp);
2271
2272 /* The only missing mandatory param possible today is
2273 * the state cookie for an INIT-ACK chunk.
2274 */
2275 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie)
2276 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE,
2277 chunk, errp);
2278
2279 /* Verify all the variable length parameters */
2280 sctp_walk_params(param, peer_init, init_hdr.params) {
2281 result = sctp_verify_param(net, ep, asoc, param, cid,
2282 chunk, errp);
2283 switch (result) {
2284 case SCTP_IERROR_ABORT:
2285 case SCTP_IERROR_NOMEM:
2286 return 0;
2287 case SCTP_IERROR_ERROR:
2288 return 1;
2289 case SCTP_IERROR_NO_ERROR:
2290 default:
2291 break;
2292 }
2293
2294 } /* for (loop through all parameters) */
2295
2296 return 1;
2297}
2298
2299/* Unpack the parameters in an INIT packet into an association.
2300 * Returns 0 on failure, else success.
2301 * FIXME: This is an association method.
2302 */
2303int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk,
2304 const union sctp_addr *peer_addr,
2305 struct sctp_init_chunk *peer_init, gfp_t gfp)
2306{
2307 struct sctp_transport *transport;
2308 struct list_head *pos, *temp;
2309 union sctp_params param;
2310 union sctp_addr addr;
2311 struct sctp_af *af;
2312 int src_match = 0;
2313
2314 /* We must include the address that the INIT packet came from.
2315 * This is the only address that matters for an INIT packet.
2316 * When processing a COOKIE ECHO, we retrieve the from address
2317 * of the INIT from the cookie.
2318 */
2319
2320 /* This implementation defaults to making the first transport
2321 * added as the primary transport. The source address seems to
2322 * be a a better choice than any of the embedded addresses.
2323 */
2324 if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE))
2325 goto nomem;
2326
2327 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr))
2328 src_match = 1;
2329
2330 /* Process the initialization parameters. */
2331 sctp_walk_params(param, peer_init, init_hdr.params) {
2332 if (!src_match && (param.p->type == SCTP_PARAM_IPV4_ADDRESS ||
2333 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) {
2334 af = sctp_get_af_specific(param_type2af(param.p->type));
2335 af->from_addr_param(&addr, param.addr,
2336 chunk->sctp_hdr->source, 0);
2337 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr))
2338 src_match = 1;
2339 }
2340
2341 if (!sctp_process_param(asoc, param, peer_addr, gfp))
2342 goto clean_up;
2343 }
2344
2345 /* source address of chunk may not match any valid address */
2346 if (!src_match)
2347 goto clean_up;
2348
2349 /* AUTH: After processing the parameters, make sure that we
2350 * have all the required info to potentially do authentications.
2351 */
2352 if (asoc->peer.auth_capable && (!asoc->peer.peer_random ||
2353 !asoc->peer.peer_hmacs))
2354 asoc->peer.auth_capable = 0;
2355
2356 /* In a non-backward compatible mode, if the peer claims
2357 * support for ADD-IP but not AUTH, the ADD-IP spec states
2358 * that we MUST ABORT the association. Section 6. The section
2359 * also give us an option to silently ignore the packet, which
2360 * is what we'll do here.
2361 */
2362 if (!asoc->base.net->sctp.addip_noauth &&
2363 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) {
2364 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP |
2365 SCTP_PARAM_DEL_IP |
2366 SCTP_PARAM_SET_PRIMARY);
2367 asoc->peer.asconf_capable = 0;
2368 goto clean_up;
2369 }
2370
2371 /* Walk list of transports, removing transports in the UNKNOWN state. */
2372 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
2373 transport = list_entry(pos, struct sctp_transport, transports);
2374 if (transport->state == SCTP_UNKNOWN) {
2375 sctp_assoc_rm_peer(asoc, transport);
2376 }
2377 }
2378
2379 /* The fixed INIT headers are always in network byte
2380 * order.
2381 */
2382 asoc->peer.i.init_tag =
2383 ntohl(peer_init->init_hdr.init_tag);
2384 asoc->peer.i.a_rwnd =
2385 ntohl(peer_init->init_hdr.a_rwnd);
2386 asoc->peer.i.num_outbound_streams =
2387 ntohs(peer_init->init_hdr.num_outbound_streams);
2388 asoc->peer.i.num_inbound_streams =
2389 ntohs(peer_init->init_hdr.num_inbound_streams);
2390 asoc->peer.i.initial_tsn =
2391 ntohl(peer_init->init_hdr.initial_tsn);
2392
2393 asoc->strreset_inseq = asoc->peer.i.initial_tsn;
2394
2395 /* Apply the upper bounds for output streams based on peer's
2396 * number of inbound streams.
2397 */
2398 if (asoc->c.sinit_num_ostreams >
2399 ntohs(peer_init->init_hdr.num_inbound_streams)) {
2400 asoc->c.sinit_num_ostreams =
2401 ntohs(peer_init->init_hdr.num_inbound_streams);
2402 }
2403
2404 if (asoc->c.sinit_max_instreams >
2405 ntohs(peer_init->init_hdr.num_outbound_streams)) {
2406 asoc->c.sinit_max_instreams =
2407 ntohs(peer_init->init_hdr.num_outbound_streams);
2408 }
2409
2410 /* Copy Initiation tag from INIT to VT_peer in cookie. */
2411 asoc->c.peer_vtag = asoc->peer.i.init_tag;
2412
2413 /* Peer Rwnd : Current calculated value of the peer's rwnd. */
2414 asoc->peer.rwnd = asoc->peer.i.a_rwnd;
2415
2416 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily
2417 * high (for example, implementations MAY use the size of the receiver
2418 * advertised window).
2419 */
2420 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
2421 transports) {
2422 transport->ssthresh = asoc->peer.i.a_rwnd;
2423 }
2424
2425 /* Set up the TSN tracking pieces. */
2426 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
2427 asoc->peer.i.initial_tsn, gfp))
2428 goto clean_up;
2429
2430 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
2431 *
2432 * The stream sequence number in all the streams shall start
2433 * from 0 when the association is established. Also, when the
2434 * stream sequence number reaches the value 65535 the next
2435 * stream sequence number shall be set to 0.
2436 */
2437
2438 if (sctp_stream_init(&asoc->stream, asoc->c.sinit_num_ostreams,
2439 asoc->c.sinit_max_instreams, gfp))
2440 goto clean_up;
2441
2442 /* Update frag_point when stream_interleave may get changed. */
2443 sctp_assoc_update_frag_point(asoc);
2444
2445 if (!asoc->temp && sctp_assoc_set_id(asoc, gfp))
2446 goto clean_up;
2447
2448 /* ADDIP Section 4.1 ASCONF Chunk Procedures
2449 *
2450 * When an endpoint has an ASCONF signaled change to be sent to the
2451 * remote endpoint it should do the following:
2452 * ...
2453 * A2) A serial number should be assigned to the Chunk. The serial
2454 * number should be a monotonically increasing number. All serial
2455 * numbers are defined to be initialized at the start of the
2456 * association to the same value as the Initial TSN.
2457 */
2458 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1;
2459 return 1;
2460
2461clean_up:
2462 /* Release the transport structures. */
2463 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
2464 transport = list_entry(pos, struct sctp_transport, transports);
2465 if (transport->state != SCTP_ACTIVE)
2466 sctp_assoc_rm_peer(asoc, transport);
2467 }
2468
2469nomem:
2470 return 0;
2471}
2472
2473
2474/* Update asoc with the option described in param.
2475 *
2476 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT
2477 *
2478 * asoc is the association to update.
2479 * param is the variable length parameter to use for update.
2480 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO.
2481 * If the current packet is an INIT we want to minimize the amount of
2482 * work we do. In particular, we should not build transport
2483 * structures for the addresses.
2484 */
2485static int sctp_process_param(struct sctp_association *asoc,
2486 union sctp_params param,
2487 const union sctp_addr *peer_addr,
2488 gfp_t gfp)
2489{
2490 struct sctp_endpoint *ep = asoc->ep;
2491 union sctp_addr_param *addr_param;
2492 struct net *net = asoc->base.net;
2493 struct sctp_transport *t;
2494 enum sctp_scope scope;
2495 union sctp_addr addr;
2496 struct sctp_af *af;
2497 int retval = 1, i;
2498 u32 stale;
2499 __u16 sat;
2500
2501 /* We maintain all INIT parameters in network byte order all the
2502 * time. This allows us to not worry about whether the parameters
2503 * came from a fresh INIT, and INIT ACK, or were stored in a cookie.
2504 */
2505 switch (param.p->type) {
2506 case SCTP_PARAM_IPV6_ADDRESS:
2507 if (PF_INET6 != asoc->base.sk->sk_family)
2508 break;
2509 goto do_addr_param;
2510
2511 case SCTP_PARAM_IPV4_ADDRESS:
2512 /* v4 addresses are not allowed on v6-only socket */
2513 if (ipv6_only_sock(asoc->base.sk))
2514 break;
2515do_addr_param:
2516 af = sctp_get_af_specific(param_type2af(param.p->type));
2517 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0);
2518 scope = sctp_scope(peer_addr);
2519 if (sctp_in_scope(net, &addr, scope))
2520 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED))
2521 return 0;
2522 break;
2523
2524 case SCTP_PARAM_COOKIE_PRESERVATIVE:
2525 if (!net->sctp.cookie_preserve_enable)
2526 break;
2527
2528 stale = ntohl(param.life->lifespan_increment);
2529
2530 /* Suggested Cookie Life span increment's unit is msec,
2531 * (1/1000sec).
2532 */
2533 asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale);
2534 break;
2535
2536 case SCTP_PARAM_HOST_NAME_ADDRESS:
2537 pr_debug("%s: unimplemented SCTP_HOST_NAME_ADDRESS\n", __func__);
2538 break;
2539
2540 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
2541 /* Turn off the default values first so we'll know which
2542 * ones are really set by the peer.
2543 */
2544 asoc->peer.ipv4_address = 0;
2545 asoc->peer.ipv6_address = 0;
2546
2547 /* Assume that peer supports the address family
2548 * by which it sends a packet.
2549 */
2550 if (peer_addr->sa.sa_family == AF_INET6)
2551 asoc->peer.ipv6_address = 1;
2552 else if (peer_addr->sa.sa_family == AF_INET)
2553 asoc->peer.ipv4_address = 1;
2554
2555 /* Cycle through address types; avoid divide by 0. */
2556 sat = ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
2557 if (sat)
2558 sat /= sizeof(__u16);
2559
2560 for (i = 0; i < sat; ++i) {
2561 switch (param.sat->types[i]) {
2562 case SCTP_PARAM_IPV4_ADDRESS:
2563 asoc->peer.ipv4_address = 1;
2564 break;
2565
2566 case SCTP_PARAM_IPV6_ADDRESS:
2567 if (PF_INET6 == asoc->base.sk->sk_family)
2568 asoc->peer.ipv6_address = 1;
2569 break;
2570
2571 case SCTP_PARAM_HOST_NAME_ADDRESS:
2572 asoc->peer.hostname_address = 1;
2573 break;
2574
2575 default: /* Just ignore anything else. */
2576 break;
2577 }
2578 }
2579 break;
2580
2581 case SCTP_PARAM_STATE_COOKIE:
2582 asoc->peer.cookie_len =
2583 ntohs(param.p->length) - sizeof(struct sctp_paramhdr);
2584 kfree(asoc->peer.cookie);
2585 asoc->peer.cookie = kmemdup(param.cookie->body, asoc->peer.cookie_len, gfp);
2586 if (!asoc->peer.cookie)
2587 retval = 0;
2588 break;
2589
2590 case SCTP_PARAM_HEARTBEAT_INFO:
2591 /* Would be odd to receive, but it causes no problems. */
2592 break;
2593
2594 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
2595 /* Rejected during verify stage. */
2596 break;
2597
2598 case SCTP_PARAM_ECN_CAPABLE:
2599 if (asoc->ep->ecn_enable) {
2600 asoc->peer.ecn_capable = 1;
2601 break;
2602 }
2603 /* Fall Through */
2604 goto fall_through;
2605
2606
2607 case SCTP_PARAM_ADAPTATION_LAYER_IND:
2608 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind);
2609 break;
2610
2611 case SCTP_PARAM_SET_PRIMARY:
2612 if (!ep->asconf_enable)
2613 goto fall_through;
2614
2615 addr_param = param.v + sizeof(struct sctp_addip_param);
2616
2617 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
2618 if (af == NULL)
2619 break;
2620
2621 af->from_addr_param(&addr, addr_param,
2622 htons(asoc->peer.port), 0);
2623
2624 /* if the address is invalid, we can't process it.
2625 * XXX: see spec for what to do.
2626 */
2627 if (!af->addr_valid(&addr, NULL, NULL))
2628 break;
2629
2630 t = sctp_assoc_lookup_paddr(asoc, &addr);
2631 if (!t)
2632 break;
2633
2634 sctp_assoc_set_primary(asoc, t);
2635 break;
2636
2637 case SCTP_PARAM_SUPPORTED_EXT:
2638 sctp_process_ext_param(asoc, param);
2639 break;
2640
2641 case SCTP_PARAM_FWD_TSN_SUPPORT:
2642 if (asoc->ep->prsctp_enable) {
2643 asoc->peer.prsctp_capable = 1;
2644 break;
2645 }
2646 /* Fall Through */
2647 goto fall_through;
2648
2649 case SCTP_PARAM_RANDOM:
2650 if (!ep->auth_enable)
2651 goto fall_through;
2652
2653 /* Save peer's random parameter */
2654 kfree(asoc->peer.peer_random);
2655 asoc->peer.peer_random = kmemdup(param.p,
2656 ntohs(param.p->length), gfp);
2657 if (!asoc->peer.peer_random) {
2658 retval = 0;
2659 break;
2660 }
2661 break;
2662
2663 case SCTP_PARAM_HMAC_ALGO:
2664 if (!ep->auth_enable)
2665 goto fall_through;
2666
2667 /* Save peer's HMAC list */
2668 kfree(asoc->peer.peer_hmacs);
2669 asoc->peer.peer_hmacs = kmemdup(param.p,
2670 ntohs(param.p->length), gfp);
2671 if (!asoc->peer.peer_hmacs) {
2672 retval = 0;
2673 break;
2674 }
2675
2676 /* Set the default HMAC the peer requested*/
2677 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo);
2678 break;
2679
2680 case SCTP_PARAM_CHUNKS:
2681 if (!ep->auth_enable)
2682 goto fall_through;
2683
2684 kfree(asoc->peer.peer_chunks);
2685 asoc->peer.peer_chunks = kmemdup(param.p,
2686 ntohs(param.p->length), gfp);
2687 if (!asoc->peer.peer_chunks)
2688 retval = 0;
2689 break;
2690fall_through:
2691 default:
2692 /* Any unrecognized parameters should have been caught
2693 * and handled by sctp_verify_param() which should be
2694 * called prior to this routine. Simply log the error
2695 * here.
2696 */
2697 pr_debug("%s: ignoring param:%d for association:%p.\n",
2698 __func__, ntohs(param.p->type), asoc);
2699 break;
2700 }
2701
2702 return retval;
2703}
2704
2705/* Select a new verification tag. */
2706__u32 sctp_generate_tag(const struct sctp_endpoint *ep)
2707{
2708 /* I believe that this random number generator complies with RFC1750.
2709 * A tag of 0 is reserved for special cases (e.g. INIT).
2710 */
2711 __u32 x;
2712
2713 do {
2714 get_random_bytes(&x, sizeof(__u32));
2715 } while (x == 0);
2716
2717 return x;
2718}
2719
2720/* Select an initial TSN to send during startup. */
2721__u32 sctp_generate_tsn(const struct sctp_endpoint *ep)
2722{
2723 __u32 retval;
2724
2725 get_random_bytes(&retval, sizeof(__u32));
2726 return retval;
2727}
2728
2729/*
2730 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF)
2731 * 0 1 2 3
2732 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2733 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2734 * | Type = 0xC1 | Chunk Flags | Chunk Length |
2735 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2736 * | Serial Number |
2737 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2738 * | Address Parameter |
2739 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2740 * | ASCONF Parameter #1 |
2741 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2742 * \ \
2743 * / .... /
2744 * \ \
2745 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2746 * | ASCONF Parameter #N |
2747 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2748 *
2749 * Address Parameter and other parameter will not be wrapped in this function
2750 */
2751static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc,
2752 union sctp_addr *addr,
2753 int vparam_len)
2754{
2755 struct sctp_addiphdr asconf;
2756 struct sctp_chunk *retval;
2757 int length = sizeof(asconf) + vparam_len;
2758 union sctp_addr_param addrparam;
2759 int addrlen;
2760 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
2761
2762 addrlen = af->to_addr_param(addr, &addrparam);
2763 if (!addrlen)
2764 return NULL;
2765 length += addrlen;
2766
2767 /* Create the chunk. */
2768 retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length,
2769 GFP_ATOMIC);
2770 if (!retval)
2771 return NULL;
2772
2773 asconf.serial = htonl(asoc->addip_serial++);
2774
2775 retval->subh.addip_hdr =
2776 sctp_addto_chunk(retval, sizeof(asconf), &asconf);
2777 retval->param_hdr.v =
2778 sctp_addto_chunk(retval, addrlen, &addrparam);
2779
2780 return retval;
2781}
2782
2783/* ADDIP
2784 * 3.2.1 Add IP Address
2785 * 0 1 2 3
2786 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2787 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2788 * | Type = 0xC001 | Length = Variable |
2789 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2790 * | ASCONF-Request Correlation ID |
2791 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2792 * | Address Parameter |
2793 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2794 *
2795 * 3.2.2 Delete IP Address
2796 * 0 1 2 3
2797 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2798 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2799 * | Type = 0xC002 | Length = Variable |
2800 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2801 * | ASCONF-Request Correlation ID |
2802 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2803 * | Address Parameter |
2804 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2805 *
2806 */
2807struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc,
2808 union sctp_addr *laddr,
2809 struct sockaddr *addrs,
2810 int addrcnt, __be16 flags)
2811{
2812 union sctp_addr_param addr_param;
2813 struct sctp_addip_param param;
2814 int paramlen = sizeof(param);
2815 struct sctp_chunk *retval;
2816 int addr_param_len = 0;
2817 union sctp_addr *addr;
2818 int totallen = 0, i;
2819 int del_pickup = 0;
2820 struct sctp_af *af;
2821 void *addr_buf;
2822
2823 /* Get total length of all the address parameters. */
2824 addr_buf = addrs;
2825 for (i = 0; i < addrcnt; i++) {
2826 addr = addr_buf;
2827 af = sctp_get_af_specific(addr->v4.sin_family);
2828 addr_param_len = af->to_addr_param(addr, &addr_param);
2829
2830 totallen += paramlen;
2831 totallen += addr_param_len;
2832
2833 addr_buf += af->sockaddr_len;
2834 if (asoc->asconf_addr_del_pending && !del_pickup) {
2835 /* reuse the parameter length from the same scope one */
2836 totallen += paramlen;
2837 totallen += addr_param_len;
2838 del_pickup = 1;
2839
2840 pr_debug("%s: picked same-scope del_pending addr, "
2841 "totallen for all addresses is %d\n",
2842 __func__, totallen);
2843 }
2844 }
2845
2846 /* Create an asconf chunk with the required length. */
2847 retval = sctp_make_asconf(asoc, laddr, totallen);
2848 if (!retval)
2849 return NULL;
2850
2851 /* Add the address parameters to the asconf chunk. */
2852 addr_buf = addrs;
2853 for (i = 0; i < addrcnt; i++) {
2854 addr = addr_buf;
2855 af = sctp_get_af_specific(addr->v4.sin_family);
2856 addr_param_len = af->to_addr_param(addr, &addr_param);
2857 param.param_hdr.type = flags;
2858 param.param_hdr.length = htons(paramlen + addr_param_len);
2859 param.crr_id = htonl(i);
2860
2861 sctp_addto_chunk(retval, paramlen, ¶m);
2862 sctp_addto_chunk(retval, addr_param_len, &addr_param);
2863
2864 addr_buf += af->sockaddr_len;
2865 }
2866 if (flags == SCTP_PARAM_ADD_IP && del_pickup) {
2867 addr = asoc->asconf_addr_del_pending;
2868 af = sctp_get_af_specific(addr->v4.sin_family);
2869 addr_param_len = af->to_addr_param(addr, &addr_param);
2870 param.param_hdr.type = SCTP_PARAM_DEL_IP;
2871 param.param_hdr.length = htons(paramlen + addr_param_len);
2872 param.crr_id = htonl(i);
2873
2874 sctp_addto_chunk(retval, paramlen, ¶m);
2875 sctp_addto_chunk(retval, addr_param_len, &addr_param);
2876 }
2877 return retval;
2878}
2879
2880/* ADDIP
2881 * 3.2.4 Set Primary IP Address
2882 * 0 1 2 3
2883 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2884 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2885 * | Type =0xC004 | Length = Variable |
2886 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2887 * | ASCONF-Request Correlation ID |
2888 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2889 * | Address Parameter |
2890 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2891 *
2892 * Create an ASCONF chunk with Set Primary IP address parameter.
2893 */
2894struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
2895 union sctp_addr *addr)
2896{
2897 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
2898 union sctp_addr_param addrparam;
2899 struct sctp_addip_param param;
2900 struct sctp_chunk *retval;
2901 int len = sizeof(param);
2902 int addrlen;
2903
2904 addrlen = af->to_addr_param(addr, &addrparam);
2905 if (!addrlen)
2906 return NULL;
2907 len += addrlen;
2908
2909 /* Create the chunk and make asconf header. */
2910 retval = sctp_make_asconf(asoc, addr, len);
2911 if (!retval)
2912 return NULL;
2913
2914 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY;
2915 param.param_hdr.length = htons(len);
2916 param.crr_id = 0;
2917
2918 sctp_addto_chunk(retval, sizeof(param), ¶m);
2919 sctp_addto_chunk(retval, addrlen, &addrparam);
2920
2921 return retval;
2922}
2923
2924/* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK)
2925 * 0 1 2 3
2926 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
2927 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2928 * | Type = 0x80 | Chunk Flags | Chunk Length |
2929 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2930 * | Serial Number |
2931 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2932 * | ASCONF Parameter Response#1 |
2933 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2934 * \ \
2935 * / .... /
2936 * \ \
2937 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2938 * | ASCONF Parameter Response#N |
2939 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2940 *
2941 * Create an ASCONF_ACK chunk with enough space for the parameter responses.
2942 */
2943static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc,
2944 __u32 serial, int vparam_len)
2945{
2946 struct sctp_addiphdr asconf;
2947 struct sctp_chunk *retval;
2948 int length = sizeof(asconf) + vparam_len;
2949
2950 /* Create the chunk. */
2951 retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length,
2952 GFP_ATOMIC);
2953 if (!retval)
2954 return NULL;
2955
2956 asconf.serial = htonl(serial);
2957
2958 retval->subh.addip_hdr =
2959 sctp_addto_chunk(retval, sizeof(asconf), &asconf);
2960
2961 return retval;
2962}
2963
2964/* Add response parameters to an ASCONF_ACK chunk. */
2965static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id,
2966 __be16 err_code,
2967 struct sctp_addip_param *asconf_param)
2968{
2969 struct sctp_addip_param ack_param;
2970 struct sctp_errhdr err_param;
2971 int asconf_param_len = 0;
2972 int err_param_len = 0;
2973 __be16 response_type;
2974
2975 if (SCTP_ERROR_NO_ERROR == err_code) {
2976 response_type = SCTP_PARAM_SUCCESS_REPORT;
2977 } else {
2978 response_type = SCTP_PARAM_ERR_CAUSE;
2979 err_param_len = sizeof(err_param);
2980 if (asconf_param)
2981 asconf_param_len =
2982 ntohs(asconf_param->param_hdr.length);
2983 }
2984
2985 /* Add Success Indication or Error Cause Indication parameter. */
2986 ack_param.param_hdr.type = response_type;
2987 ack_param.param_hdr.length = htons(sizeof(ack_param) +
2988 err_param_len +
2989 asconf_param_len);
2990 ack_param.crr_id = crr_id;
2991 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param);
2992
2993 if (SCTP_ERROR_NO_ERROR == err_code)
2994 return;
2995
2996 /* Add Error Cause parameter. */
2997 err_param.cause = err_code;
2998 err_param.length = htons(err_param_len + asconf_param_len);
2999 sctp_addto_chunk(chunk, err_param_len, &err_param);
3000
3001 /* Add the failed TLV copied from ASCONF chunk. */
3002 if (asconf_param)
3003 sctp_addto_chunk(chunk, asconf_param_len, asconf_param);
3004}
3005
3006/* Process a asconf parameter. */
3007static __be16 sctp_process_asconf_param(struct sctp_association *asoc,
3008 struct sctp_chunk *asconf,
3009 struct sctp_addip_param *asconf_param)
3010{
3011 union sctp_addr_param *addr_param;
3012 struct sctp_transport *peer;
3013 union sctp_addr addr;
3014 struct sctp_af *af;
3015
3016 addr_param = (void *)asconf_param + sizeof(*asconf_param);
3017
3018 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP &&
3019 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP &&
3020 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY)
3021 return SCTP_ERROR_UNKNOWN_PARAM;
3022
3023 switch (addr_param->p.type) {
3024 case SCTP_PARAM_IPV6_ADDRESS:
3025 if (!asoc->peer.ipv6_address)
3026 return SCTP_ERROR_DNS_FAILED;
3027 break;
3028 case SCTP_PARAM_IPV4_ADDRESS:
3029 if (!asoc->peer.ipv4_address)
3030 return SCTP_ERROR_DNS_FAILED;
3031 break;
3032 default:
3033 return SCTP_ERROR_DNS_FAILED;
3034 }
3035
3036 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
3037 if (unlikely(!af))
3038 return SCTP_ERROR_DNS_FAILED;
3039
3040 af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0);
3041
3042 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast
3043 * or multicast address.
3044 * (note: wildcard is permitted and requires special handling so
3045 * make sure we check for that)
3046 */
3047 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb))
3048 return SCTP_ERROR_DNS_FAILED;
3049
3050 switch (asconf_param->param_hdr.type) {
3051 case SCTP_PARAM_ADD_IP:
3052 /* Section 4.2.1:
3053 * If the address 0.0.0.0 or ::0 is provided, the source
3054 * address of the packet MUST be added.
3055 */
3056 if (af->is_any(&addr))
3057 memcpy(&addr, &asconf->source, sizeof(addr));
3058
3059 if (security_sctp_bind_connect(asoc->ep->base.sk,
3060 SCTP_PARAM_ADD_IP,
3061 (struct sockaddr *)&addr,
3062 af->sockaddr_len))
3063 return SCTP_ERROR_REQ_REFUSED;
3064
3065 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address
3066 * request and does not have the local resources to add this
3067 * new address to the association, it MUST return an Error
3068 * Cause TLV set to the new error code 'Operation Refused
3069 * Due to Resource Shortage'.
3070 */
3071
3072 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED);
3073 if (!peer)
3074 return SCTP_ERROR_RSRC_LOW;
3075
3076 /* Start the heartbeat timer. */
3077 sctp_transport_reset_hb_timer(peer);
3078 asoc->new_transport = peer;
3079 break;
3080 case SCTP_PARAM_DEL_IP:
3081 /* ADDIP 4.3 D7) If a request is received to delete the
3082 * last remaining IP address of a peer endpoint, the receiver
3083 * MUST send an Error Cause TLV with the error cause set to the
3084 * new error code 'Request to Delete Last Remaining IP Address'.
3085 */
3086 if (asoc->peer.transport_count == 1)
3087 return SCTP_ERROR_DEL_LAST_IP;
3088
3089 /* ADDIP 4.3 D8) If a request is received to delete an IP
3090 * address which is also the source address of the IP packet
3091 * which contained the ASCONF chunk, the receiver MUST reject
3092 * this request. To reject the request the receiver MUST send
3093 * an Error Cause TLV set to the new error code 'Request to
3094 * Delete Source IP Address'
3095 */
3096 if (sctp_cmp_addr_exact(&asconf->source, &addr))
3097 return SCTP_ERROR_DEL_SRC_IP;
3098
3099 /* Section 4.2.2
3100 * If the address 0.0.0.0 or ::0 is provided, all
3101 * addresses of the peer except the source address of the
3102 * packet MUST be deleted.
3103 */
3104 if (af->is_any(&addr)) {
3105 sctp_assoc_set_primary(asoc, asconf->transport);
3106 sctp_assoc_del_nonprimary_peers(asoc,
3107 asconf->transport);
3108 return SCTP_ERROR_NO_ERROR;
3109 }
3110
3111 /* If the address is not part of the association, the
3112 * ASCONF-ACK with Error Cause Indication Parameter
3113 * which including cause of Unresolvable Address should
3114 * be sent.
3115 */
3116 peer = sctp_assoc_lookup_paddr(asoc, &addr);
3117 if (!peer)
3118 return SCTP_ERROR_DNS_FAILED;
3119
3120 sctp_assoc_rm_peer(asoc, peer);
3121 break;
3122 case SCTP_PARAM_SET_PRIMARY:
3123 /* ADDIP Section 4.2.4
3124 * If the address 0.0.0.0 or ::0 is provided, the receiver
3125 * MAY mark the source address of the packet as its
3126 * primary.
3127 */
3128 if (af->is_any(&addr))
3129 memcpy(&addr.v4, sctp_source(asconf), sizeof(addr));
3130
3131 if (security_sctp_bind_connect(asoc->ep->base.sk,
3132 SCTP_PARAM_SET_PRIMARY,
3133 (struct sockaddr *)&addr,
3134 af->sockaddr_len))
3135 return SCTP_ERROR_REQ_REFUSED;
3136
3137 peer = sctp_assoc_lookup_paddr(asoc, &addr);
3138 if (!peer)
3139 return SCTP_ERROR_DNS_FAILED;
3140
3141 sctp_assoc_set_primary(asoc, peer);
3142 break;
3143 }
3144
3145 return SCTP_ERROR_NO_ERROR;
3146}
3147
3148/* Verify the ASCONF packet before we process it. */
3149bool sctp_verify_asconf(const struct sctp_association *asoc,
3150 struct sctp_chunk *chunk, bool addr_param_needed,
3151 struct sctp_paramhdr **errp)
3152{
3153 struct sctp_addip_chunk *addip;
3154 bool addr_param_seen = false;
3155 union sctp_params param;
3156
3157 addip = (struct sctp_addip_chunk *)chunk->chunk_hdr;
3158 sctp_walk_params(param, addip, addip_hdr.params) {
3159 size_t length = ntohs(param.p->length);
3160
3161 *errp = param.p;
3162 switch (param.p->type) {
3163 case SCTP_PARAM_ERR_CAUSE:
3164 break;
3165 case SCTP_PARAM_IPV4_ADDRESS:
3166 if (length != sizeof(struct sctp_ipv4addr_param))
3167 return false;
3168 /* ensure there is only one addr param and it's in the
3169 * beginning of addip_hdr params, or we reject it.
3170 */
3171 if (param.v != addip->addip_hdr.params)
3172 return false;
3173 addr_param_seen = true;
3174 break;
3175 case SCTP_PARAM_IPV6_ADDRESS:
3176 if (length != sizeof(struct sctp_ipv6addr_param))
3177 return false;
3178 if (param.v != addip->addip_hdr.params)
3179 return false;
3180 addr_param_seen = true;
3181 break;
3182 case SCTP_PARAM_ADD_IP:
3183 case SCTP_PARAM_DEL_IP:
3184 case SCTP_PARAM_SET_PRIMARY:
3185 /* In ASCONF chunks, these need to be first. */
3186 if (addr_param_needed && !addr_param_seen)
3187 return false;
3188 length = ntohs(param.addip->param_hdr.length);
3189 if (length < sizeof(struct sctp_addip_param) +
3190 sizeof(**errp))
3191 return false;
3192 break;
3193 case SCTP_PARAM_SUCCESS_REPORT:
3194 case SCTP_PARAM_ADAPTATION_LAYER_IND:
3195 if (length != sizeof(struct sctp_addip_param))
3196 return false;
3197 break;
3198 default:
3199 /* This is unkown to us, reject! */
3200 return false;
3201 }
3202 }
3203
3204 /* Remaining sanity checks. */
3205 if (addr_param_needed && !addr_param_seen)
3206 return false;
3207 if (!addr_param_needed && addr_param_seen)
3208 return false;
3209 if (param.v != chunk->chunk_end)
3210 return false;
3211
3212 return true;
3213}
3214
3215/* Process an incoming ASCONF chunk with the next expected serial no. and
3216 * return an ASCONF_ACK chunk to be sent in response.
3217 */
3218struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
3219 struct sctp_chunk *asconf)
3220{
3221 union sctp_addr_param *addr_param;
3222 struct sctp_addip_chunk *addip;
3223 struct sctp_chunk *asconf_ack;
3224 bool all_param_pass = true;
3225 struct sctp_addiphdr *hdr;
3226 int length = 0, chunk_len;
3227 union sctp_params param;
3228 __be16 err_code;
3229 __u32 serial;
3230
3231 addip = (struct sctp_addip_chunk *)asconf->chunk_hdr;
3232 chunk_len = ntohs(asconf->chunk_hdr->length) -
3233 sizeof(struct sctp_chunkhdr);
3234 hdr = (struct sctp_addiphdr *)asconf->skb->data;
3235 serial = ntohl(hdr->serial);
3236
3237 /* Skip the addiphdr and store a pointer to address parameter. */
3238 length = sizeof(*hdr);
3239 addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
3240 chunk_len -= length;
3241
3242 /* Skip the address parameter and store a pointer to the first
3243 * asconf parameter.
3244 */
3245 length = ntohs(addr_param->p.length);
3246 chunk_len -= length;
3247
3248 /* create an ASCONF_ACK chunk.
3249 * Based on the definitions of parameters, we know that the size of
3250 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF
3251 * parameters.
3252 */
3253 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4);
3254 if (!asconf_ack)
3255 goto done;
3256
3257 /* Process the TLVs contained within the ASCONF chunk. */
3258 sctp_walk_params(param, addip, addip_hdr.params) {
3259 /* Skip preceeding address parameters. */
3260 if (param.p->type == SCTP_PARAM_IPV4_ADDRESS ||
3261 param.p->type == SCTP_PARAM_IPV6_ADDRESS)
3262 continue;
3263
3264 err_code = sctp_process_asconf_param(asoc, asconf,
3265 param.addip);
3266 /* ADDIP 4.1 A7)
3267 * If an error response is received for a TLV parameter,
3268 * all TLVs with no response before the failed TLV are
3269 * considered successful if not reported. All TLVs after
3270 * the failed response are considered unsuccessful unless
3271 * a specific success indication is present for the parameter.
3272 */
3273 if (err_code != SCTP_ERROR_NO_ERROR)
3274 all_param_pass = false;
3275 if (!all_param_pass)
3276 sctp_add_asconf_response(asconf_ack, param.addip->crr_id,
3277 err_code, param.addip);
3278
3279 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add
3280 * an IP address sends an 'Out of Resource' in its response, it
3281 * MUST also fail any subsequent add or delete requests bundled
3282 * in the ASCONF.
3283 */
3284 if (err_code == SCTP_ERROR_RSRC_LOW)
3285 goto done;
3286 }
3287done:
3288 asoc->peer.addip_serial++;
3289
3290 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc
3291 * after freeing the reference to old asconf ack if any.
3292 */
3293 if (asconf_ack) {
3294 sctp_chunk_hold(asconf_ack);
3295 list_add_tail(&asconf_ack->transmitted_list,
3296 &asoc->asconf_ack_list);
3297 }
3298
3299 return asconf_ack;
3300}
3301
3302/* Process a asconf parameter that is successfully acked. */
3303static void sctp_asconf_param_success(struct sctp_association *asoc,
3304 struct sctp_addip_param *asconf_param)
3305{
3306 struct sctp_bind_addr *bp = &asoc->base.bind_addr;
3307 union sctp_addr_param *addr_param;
3308 struct sctp_sockaddr_entry *saddr;
3309 struct sctp_transport *transport;
3310 union sctp_addr addr;
3311 struct sctp_af *af;
3312
3313 addr_param = (void *)asconf_param + sizeof(*asconf_param);
3314
3315 /* We have checked the packet before, so we do not check again. */
3316 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
3317 af->from_addr_param(&addr, addr_param, htons(bp->port), 0);
3318
3319 switch (asconf_param->param_hdr.type) {
3320 case SCTP_PARAM_ADD_IP:
3321 /* This is always done in BH context with a socket lock
3322 * held, so the list can not change.
3323 */
3324 local_bh_disable();
3325 list_for_each_entry(saddr, &bp->address_list, list) {
3326 if (sctp_cmp_addr_exact(&saddr->a, &addr))
3327 saddr->state = SCTP_ADDR_SRC;
3328 }
3329 local_bh_enable();
3330 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
3331 transports) {
3332 sctp_transport_dst_release(transport);
3333 }
3334 break;
3335 case SCTP_PARAM_DEL_IP:
3336 local_bh_disable();
3337 sctp_del_bind_addr(bp, &addr);
3338 if (asoc->asconf_addr_del_pending != NULL &&
3339 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) {
3340 kfree(asoc->asconf_addr_del_pending);
3341 asoc->asconf_addr_del_pending = NULL;
3342 }
3343 local_bh_enable();
3344 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
3345 transports) {
3346 sctp_transport_dst_release(transport);
3347 }
3348 break;
3349 default:
3350 break;
3351 }
3352}
3353
3354/* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk
3355 * for the given asconf parameter. If there is no response for this parameter,
3356 * return the error code based on the third argument 'no_err'.
3357 * ADDIP 4.1
3358 * A7) If an error response is received for a TLV parameter, all TLVs with no
3359 * response before the failed TLV are considered successful if not reported.
3360 * All TLVs after the failed response are considered unsuccessful unless a
3361 * specific success indication is present for the parameter.
3362 */
3363static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack,
3364 struct sctp_addip_param *asconf_param,
3365 int no_err)
3366{
3367 struct sctp_addip_param *asconf_ack_param;
3368 struct sctp_errhdr *err_param;
3369 int asconf_ack_len;
3370 __be16 err_code;
3371 int length;
3372
3373 if (no_err)
3374 err_code = SCTP_ERROR_NO_ERROR;
3375 else
3376 err_code = SCTP_ERROR_REQ_REFUSED;
3377
3378 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) -
3379 sizeof(struct sctp_chunkhdr);
3380
3381 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to
3382 * the first asconf_ack parameter.
3383 */
3384 length = sizeof(struct sctp_addiphdr);
3385 asconf_ack_param = (struct sctp_addip_param *)(asconf_ack->skb->data +
3386 length);
3387 asconf_ack_len -= length;
3388
3389 while (asconf_ack_len > 0) {
3390 if (asconf_ack_param->crr_id == asconf_param->crr_id) {
3391 switch (asconf_ack_param->param_hdr.type) {
3392 case SCTP_PARAM_SUCCESS_REPORT:
3393 return SCTP_ERROR_NO_ERROR;
3394 case SCTP_PARAM_ERR_CAUSE:
3395 length = sizeof(*asconf_ack_param);
3396 err_param = (void *)asconf_ack_param + length;
3397 asconf_ack_len -= length;
3398 if (asconf_ack_len > 0)
3399 return err_param->cause;
3400 else
3401 return SCTP_ERROR_INV_PARAM;
3402 break;
3403 default:
3404 return SCTP_ERROR_INV_PARAM;
3405 }
3406 }
3407
3408 length = ntohs(asconf_ack_param->param_hdr.length);
3409 asconf_ack_param = (void *)asconf_ack_param + length;
3410 asconf_ack_len -= length;
3411 }
3412
3413 return err_code;
3414}
3415
3416/* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */
3417int sctp_process_asconf_ack(struct sctp_association *asoc,
3418 struct sctp_chunk *asconf_ack)
3419{
3420 struct sctp_chunk *asconf = asoc->addip_last_asconf;
3421 struct sctp_addip_param *asconf_param;
3422 __be16 err_code = SCTP_ERROR_NO_ERROR;
3423 union sctp_addr_param *addr_param;
3424 int asconf_len = asconf->skb->len;
3425 int all_param_pass = 0;
3426 int length = 0;
3427 int no_err = 1;
3428 int retval = 0;
3429
3430 /* Skip the chunkhdr and addiphdr from the last asconf sent and store
3431 * a pointer to address parameter.
3432 */
3433 length = sizeof(struct sctp_addip_chunk);
3434 addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
3435 asconf_len -= length;
3436
3437 /* Skip the address parameter in the last asconf sent and store a
3438 * pointer to the first asconf parameter.
3439 */
3440 length = ntohs(addr_param->p.length);
3441 asconf_param = (void *)addr_param + length;
3442 asconf_len -= length;
3443
3444 /* ADDIP 4.1
3445 * A8) If there is no response(s) to specific TLV parameter(s), and no
3446 * failures are indicated, then all request(s) are considered
3447 * successful.
3448 */
3449 if (asconf_ack->skb->len == sizeof(struct sctp_addiphdr))
3450 all_param_pass = 1;
3451
3452 /* Process the TLVs contained in the last sent ASCONF chunk. */
3453 while (asconf_len > 0) {
3454 if (all_param_pass)
3455 err_code = SCTP_ERROR_NO_ERROR;
3456 else {
3457 err_code = sctp_get_asconf_response(asconf_ack,
3458 asconf_param,
3459 no_err);
3460 if (no_err && (SCTP_ERROR_NO_ERROR != err_code))
3461 no_err = 0;
3462 }
3463
3464 switch (err_code) {
3465 case SCTP_ERROR_NO_ERROR:
3466 sctp_asconf_param_success(asoc, asconf_param);
3467 break;
3468
3469 case SCTP_ERROR_RSRC_LOW:
3470 retval = 1;
3471 break;
3472
3473 case SCTP_ERROR_UNKNOWN_PARAM:
3474 /* Disable sending this type of asconf parameter in
3475 * future.
3476 */
3477 asoc->peer.addip_disabled_mask |=
3478 asconf_param->param_hdr.type;
3479 break;
3480
3481 case SCTP_ERROR_REQ_REFUSED:
3482 case SCTP_ERROR_DEL_LAST_IP:
3483 case SCTP_ERROR_DEL_SRC_IP:
3484 default:
3485 break;
3486 }
3487
3488 /* Skip the processed asconf parameter and move to the next
3489 * one.
3490 */
3491 length = ntohs(asconf_param->param_hdr.length);
3492 asconf_param = (void *)asconf_param + length;
3493 asconf_len -= length;
3494 }
3495
3496 if (no_err && asoc->src_out_of_asoc_ok) {
3497 asoc->src_out_of_asoc_ok = 0;
3498 sctp_transport_immediate_rtx(asoc->peer.primary_path);
3499 }
3500
3501 /* Free the cached last sent asconf chunk. */
3502 list_del_init(&asconf->transmitted_list);
3503 sctp_chunk_free(asconf);
3504 asoc->addip_last_asconf = NULL;
3505
3506 return retval;
3507}
3508
3509/* Make a FWD TSN chunk. */
3510struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
3511 __u32 new_cum_tsn, size_t nstreams,
3512 struct sctp_fwdtsn_skip *skiplist)
3513{
3514 struct sctp_chunk *retval = NULL;
3515 struct sctp_fwdtsn_hdr ftsn_hdr;
3516 struct sctp_fwdtsn_skip skip;
3517 size_t hint;
3518 int i;
3519
3520 hint = (nstreams + 1) * sizeof(__u32);
3521
3522 retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint, GFP_ATOMIC);
3523
3524 if (!retval)
3525 return NULL;
3526
3527 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn);
3528 retval->subh.fwdtsn_hdr =
3529 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr);
3530
3531 for (i = 0; i < nstreams; i++) {
3532 skip.stream = skiplist[i].stream;
3533 skip.ssn = skiplist[i].ssn;
3534 sctp_addto_chunk(retval, sizeof(skip), &skip);
3535 }
3536
3537 return retval;
3538}
3539
3540struct sctp_chunk *sctp_make_ifwdtsn(const struct sctp_association *asoc,
3541 __u32 new_cum_tsn, size_t nstreams,
3542 struct sctp_ifwdtsn_skip *skiplist)
3543{
3544 struct sctp_chunk *retval = NULL;
3545 struct sctp_ifwdtsn_hdr ftsn_hdr;
3546 size_t hint;
3547
3548 hint = (nstreams + 1) * sizeof(__u32);
3549
3550 retval = sctp_make_control(asoc, SCTP_CID_I_FWD_TSN, 0, hint,
3551 GFP_ATOMIC);
3552 if (!retval)
3553 return NULL;
3554
3555 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn);
3556 retval->subh.ifwdtsn_hdr =
3557 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr);
3558
3559 sctp_addto_chunk(retval, nstreams * sizeof(skiplist[0]), skiplist);
3560
3561 return retval;
3562}
3563
3564/* RE-CONFIG 3.1 (RE-CONFIG chunk)
3565 * 0 1 2 3
3566 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
3567 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3568 * | Type = 130 | Chunk Flags | Chunk Length |
3569 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3570 * \ \
3571 * / Re-configuration Parameter /
3572 * \ \
3573 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3574 * \ \
3575 * / Re-configuration Parameter (optional) /
3576 * \ \
3577 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3578 */
3579static struct sctp_chunk *sctp_make_reconf(const struct sctp_association *asoc,
3580 int length)
3581{
3582 struct sctp_reconf_chunk *reconf;
3583 struct sctp_chunk *retval;
3584
3585 retval = sctp_make_control(asoc, SCTP_CID_RECONF, 0, length,
3586 GFP_ATOMIC);
3587 if (!retval)
3588 return NULL;
3589
3590 reconf = (struct sctp_reconf_chunk *)retval->chunk_hdr;
3591 retval->param_hdr.v = reconf->params;
3592
3593 return retval;
3594}
3595
3596/* RE-CONFIG 4.1 (STREAM OUT RESET)
3597 * 0 1 2 3
3598 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
3599 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3600 * | Parameter Type = 13 | Parameter Length = 16 + 2 * N |
3601 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3602 * | Re-configuration Request Sequence Number |
3603 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3604 * | Re-configuration Response Sequence Number |
3605 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3606 * | Sender's Last Assigned TSN |
3607 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3608 * | Stream Number 1 (optional) | Stream Number 2 (optional) |
3609 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3610 * / ...... /
3611 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3612 * | Stream Number N-1 (optional) | Stream Number N (optional) |
3613 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3614 *
3615 * RE-CONFIG 4.2 (STREAM IN RESET)
3616 * 0 1 2 3
3617 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
3618 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3619 * | Parameter Type = 14 | Parameter Length = 8 + 2 * N |
3620 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3621 * | Re-configuration Request Sequence Number |
3622 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3623 * | Stream Number 1 (optional) | Stream Number 2 (optional) |
3624 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3625 * / ...... /
3626 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3627 * | Stream Number N-1 (optional) | Stream Number N (optional) |
3628 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3629 */
3630struct sctp_chunk *sctp_make_strreset_req(
3631 const struct sctp_association *asoc,
3632 __u16 stream_num, __be16 *stream_list,
3633 bool out, bool in)
3634{
3635 __u16 stream_len = stream_num * sizeof(__u16);
3636 struct sctp_strreset_outreq outreq;
3637 struct sctp_strreset_inreq inreq;
3638 struct sctp_chunk *retval;
3639 __u16 outlen, inlen;
3640
3641 outlen = (sizeof(outreq) + stream_len) * out;
3642 inlen = (sizeof(inreq) + stream_len) * in;
3643
3644 retval = sctp_make_reconf(asoc, outlen + inlen);
3645 if (!retval)
3646 return NULL;
3647
3648 if (outlen) {
3649 outreq.param_hdr.type = SCTP_PARAM_RESET_OUT_REQUEST;
3650 outreq.param_hdr.length = htons(outlen);
3651 outreq.request_seq = htonl(asoc->strreset_outseq);
3652 outreq.response_seq = htonl(asoc->strreset_inseq - 1);
3653 outreq.send_reset_at_tsn = htonl(asoc->next_tsn - 1);
3654
3655 sctp_addto_chunk(retval, sizeof(outreq), &outreq);
3656
3657 if (stream_len)
3658 sctp_addto_chunk(retval, stream_len, stream_list);
3659 }
3660
3661 if (inlen) {
3662 inreq.param_hdr.type = SCTP_PARAM_RESET_IN_REQUEST;
3663 inreq.param_hdr.length = htons(inlen);
3664 inreq.request_seq = htonl(asoc->strreset_outseq + out);
3665
3666 sctp_addto_chunk(retval, sizeof(inreq), &inreq);
3667
3668 if (stream_len)
3669 sctp_addto_chunk(retval, stream_len, stream_list);
3670 }
3671
3672 return retval;
3673}
3674
3675/* RE-CONFIG 4.3 (SSN/TSN RESET ALL)
3676 * 0 1 2 3
3677 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
3678 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3679 * | Parameter Type = 15 | Parameter Length = 8 |
3680 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3681 * | Re-configuration Request Sequence Number |
3682 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3683 */
3684struct sctp_chunk *sctp_make_strreset_tsnreq(
3685 const struct sctp_association *asoc)
3686{
3687 struct sctp_strreset_tsnreq tsnreq;
3688 __u16 length = sizeof(tsnreq);
3689 struct sctp_chunk *retval;
3690
3691 retval = sctp_make_reconf(asoc, length);
3692 if (!retval)
3693 return NULL;
3694
3695 tsnreq.param_hdr.type = SCTP_PARAM_RESET_TSN_REQUEST;
3696 tsnreq.param_hdr.length = htons(length);
3697 tsnreq.request_seq = htonl(asoc->strreset_outseq);
3698
3699 sctp_addto_chunk(retval, sizeof(tsnreq), &tsnreq);
3700
3701 return retval;
3702}
3703
3704/* RE-CONFIG 4.5/4.6 (ADD STREAM)
3705 * 0 1 2 3
3706 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
3707 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3708 * | Parameter Type = 17 | Parameter Length = 12 |
3709 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3710 * | Re-configuration Request Sequence Number |
3711 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3712 * | Number of new streams | Reserved |
3713 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3714 */
3715struct sctp_chunk *sctp_make_strreset_addstrm(
3716 const struct sctp_association *asoc,
3717 __u16 out, __u16 in)
3718{
3719 struct sctp_strreset_addstrm addstrm;
3720 __u16 size = sizeof(addstrm);
3721 struct sctp_chunk *retval;
3722
3723 retval = sctp_make_reconf(asoc, (!!out + !!in) * size);
3724 if (!retval)
3725 return NULL;
3726
3727 if (out) {
3728 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_OUT_STREAMS;
3729 addstrm.param_hdr.length = htons(size);
3730 addstrm.number_of_streams = htons(out);
3731 addstrm.request_seq = htonl(asoc->strreset_outseq);
3732 addstrm.reserved = 0;
3733
3734 sctp_addto_chunk(retval, size, &addstrm);
3735 }
3736
3737 if (in) {
3738 addstrm.param_hdr.type = SCTP_PARAM_RESET_ADD_IN_STREAMS;
3739 addstrm.param_hdr.length = htons(size);
3740 addstrm.number_of_streams = htons(in);
3741 addstrm.request_seq = htonl(asoc->strreset_outseq + !!out);
3742 addstrm.reserved = 0;
3743
3744 sctp_addto_chunk(retval, size, &addstrm);
3745 }
3746
3747 return retval;
3748}
3749
3750/* RE-CONFIG 4.4 (RESP)
3751 * 0 1 2 3
3752 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
3753 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3754 * | Parameter Type = 16 | Parameter Length |
3755 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3756 * | Re-configuration Response Sequence Number |
3757 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3758 * | Result |
3759 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3760 */
3761struct sctp_chunk *sctp_make_strreset_resp(const struct sctp_association *asoc,
3762 __u32 result, __u32 sn)
3763{
3764 struct sctp_strreset_resp resp;
3765 __u16 length = sizeof(resp);
3766 struct sctp_chunk *retval;
3767
3768 retval = sctp_make_reconf(asoc, length);
3769 if (!retval)
3770 return NULL;
3771
3772 resp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE;
3773 resp.param_hdr.length = htons(length);
3774 resp.response_seq = htonl(sn);
3775 resp.result = htonl(result);
3776
3777 sctp_addto_chunk(retval, sizeof(resp), &resp);
3778
3779 return retval;
3780}
3781
3782/* RE-CONFIG 4.4 OPTIONAL (TSNRESP)
3783 * 0 1 2 3
3784 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
3785 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3786 * | Parameter Type = 16 | Parameter Length |
3787 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3788 * | Re-configuration Response Sequence Number |
3789 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3790 * | Result |
3791 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3792 * | Sender's Next TSN (optional) |
3793 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3794 * | Receiver's Next TSN (optional) |
3795 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3796 */
3797struct sctp_chunk *sctp_make_strreset_tsnresp(struct sctp_association *asoc,
3798 __u32 result, __u32 sn,
3799 __u32 sender_tsn,
3800 __u32 receiver_tsn)
3801{
3802 struct sctp_strreset_resptsn tsnresp;
3803 __u16 length = sizeof(tsnresp);
3804 struct sctp_chunk *retval;
3805
3806 retval = sctp_make_reconf(asoc, length);
3807 if (!retval)
3808 return NULL;
3809
3810 tsnresp.param_hdr.type = SCTP_PARAM_RESET_RESPONSE;
3811 tsnresp.param_hdr.length = htons(length);
3812
3813 tsnresp.response_seq = htonl(sn);
3814 tsnresp.result = htonl(result);
3815 tsnresp.senders_next_tsn = htonl(sender_tsn);
3816 tsnresp.receivers_next_tsn = htonl(receiver_tsn);
3817
3818 sctp_addto_chunk(retval, sizeof(tsnresp), &tsnresp);
3819
3820 return retval;
3821}
3822
3823bool sctp_verify_reconf(const struct sctp_association *asoc,
3824 struct sctp_chunk *chunk,
3825 struct sctp_paramhdr **errp)
3826{
3827 struct sctp_reconf_chunk *hdr;
3828 union sctp_params param;
3829 __be16 last = 0;
3830 __u16 cnt = 0;
3831
3832 hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr;
3833 sctp_walk_params(param, hdr, params) {
3834 __u16 length = ntohs(param.p->length);
3835
3836 *errp = param.p;
3837 if (cnt++ > 2)
3838 return false;
3839 switch (param.p->type) {
3840 case SCTP_PARAM_RESET_OUT_REQUEST:
3841 if (length < sizeof(struct sctp_strreset_outreq) ||
3842 (last && last != SCTP_PARAM_RESET_RESPONSE &&
3843 last != SCTP_PARAM_RESET_IN_REQUEST))
3844 return false;
3845 break;
3846 case SCTP_PARAM_RESET_IN_REQUEST:
3847 if (length < sizeof(struct sctp_strreset_inreq) ||
3848 (last && last != SCTP_PARAM_RESET_OUT_REQUEST))
3849 return false;
3850 break;
3851 case SCTP_PARAM_RESET_RESPONSE:
3852 if ((length != sizeof(struct sctp_strreset_resp) &&
3853 length != sizeof(struct sctp_strreset_resptsn)) ||
3854 (last && last != SCTP_PARAM_RESET_RESPONSE &&
3855 last != SCTP_PARAM_RESET_OUT_REQUEST))
3856 return false;
3857 break;
3858 case SCTP_PARAM_RESET_TSN_REQUEST:
3859 if (length !=
3860 sizeof(struct sctp_strreset_tsnreq) || last)
3861 return false;
3862 break;
3863 case SCTP_PARAM_RESET_ADD_IN_STREAMS:
3864 if (length != sizeof(struct sctp_strreset_addstrm) ||
3865 (last && last != SCTP_PARAM_RESET_ADD_OUT_STREAMS))
3866 return false;
3867 break;
3868 case SCTP_PARAM_RESET_ADD_OUT_STREAMS:
3869 if (length != sizeof(struct sctp_strreset_addstrm) ||
3870 (last && last != SCTP_PARAM_RESET_ADD_IN_STREAMS))
3871 return false;
3872 break;
3873 default:
3874 return false;
3875 }
3876
3877 last = param.p->type;
3878 }
3879
3880 return true;
3881}
1/* SCTP kernel implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999-2000 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 * Copyright (c) 2001-2002 Intel Corp.
6 *
7 * This file is part of the SCTP kernel implementation
8 *
9 * These functions work with the state functions in sctp_sm_statefuns.c
10 * to implement the state operations. These functions implement the
11 * steps which require modifying existing data structures.
12 *
13 * This SCTP implementation is free software;
14 * you can redistribute it and/or modify it under the terms of
15 * the GNU General Public License as published by
16 * the Free Software Foundation; either version 2, or (at your option)
17 * any later version.
18 *
19 * This SCTP implementation is distributed in the hope that it
20 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
21 * ************************
22 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
23 * See the GNU General Public License for more details.
24 *
25 * You should have received a copy of the GNU General Public License
26 * along with GNU CC; see the file COPYING. If not, write to
27 * the Free Software Foundation, 59 Temple Place - Suite 330,
28 * Boston, MA 02111-1307, USA.
29 *
30 * Please send any bug reports or fixes you make to the
31 * email address(es):
32 * lksctp developers <lksctp-developers@lists.sourceforge.net>
33 *
34 * Or submit a bug report through the following website:
35 * http://www.sf.net/projects/lksctp
36 *
37 * Written or modified by:
38 * La Monte H.P. Yarroll <piggy@acm.org>
39 * Karl Knutson <karl@athena.chicago.il.us>
40 * C. Robin <chris@hundredacre.ac.uk>
41 * Jon Grimm <jgrimm@us.ibm.com>
42 * Xingang Guo <xingang.guo@intel.com>
43 * Dajiang Zhang <dajiang.zhang@nokia.com>
44 * Sridhar Samudrala <sri@us.ibm.com>
45 * Daisy Chang <daisyc@us.ibm.com>
46 * Ardelle Fan <ardelle.fan@intel.com>
47 * Kevin Gao <kevin.gao@intel.com>
48 *
49 * Any bugs reported given to us we will try to fix... any fixes shared will
50 * be incorporated into the next SCTP release.
51 */
52
53#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
54
55#include <linux/types.h>
56#include <linux/kernel.h>
57#include <linux/ip.h>
58#include <linux/ipv6.h>
59#include <linux/net.h>
60#include <linux/inet.h>
61#include <linux/scatterlist.h>
62#include <linux/crypto.h>
63#include <linux/slab.h>
64#include <net/sock.h>
65
66#include <linux/skbuff.h>
67#include <linux/random.h> /* for get_random_bytes */
68#include <net/sctp/sctp.h>
69#include <net/sctp/sm.h>
70
71SCTP_STATIC
72struct sctp_chunk *sctp_make_chunk(const struct sctp_association *asoc,
73 __u8 type, __u8 flags, int paylen);
74static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep,
75 const struct sctp_association *asoc,
76 const struct sctp_chunk *init_chunk,
77 int *cookie_len,
78 const __u8 *raw_addrs, int addrs_len);
79static int sctp_process_param(struct sctp_association *asoc,
80 union sctp_params param,
81 const union sctp_addr *peer_addr,
82 gfp_t gfp);
83static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
84 const void *data);
85
86/* What was the inbound interface for this chunk? */
87int sctp_chunk_iif(const struct sctp_chunk *chunk)
88{
89 struct sctp_af *af;
90 int iif = 0;
91
92 af = sctp_get_af_specific(ipver2af(ip_hdr(chunk->skb)->version));
93 if (af)
94 iif = af->skb_iif(chunk->skb);
95
96 return iif;
97}
98
99/* RFC 2960 3.3.2 Initiation (INIT) (1)
100 *
101 * Note 2: The ECN capable field is reserved for future use of
102 * Explicit Congestion Notification.
103 */
104static const struct sctp_paramhdr ecap_param = {
105 SCTP_PARAM_ECN_CAPABLE,
106 cpu_to_be16(sizeof(struct sctp_paramhdr)),
107};
108static const struct sctp_paramhdr prsctp_param = {
109 SCTP_PARAM_FWD_TSN_SUPPORT,
110 cpu_to_be16(sizeof(struct sctp_paramhdr)),
111};
112
113/* A helper to initialize an op error inside a
114 * provided chunk, as most cause codes will be embedded inside an
115 * abort chunk.
116 */
117void sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code,
118 size_t paylen)
119{
120 sctp_errhdr_t err;
121 __u16 len;
122
123 /* Cause code constants are now defined in network order. */
124 err.cause = cause_code;
125 len = sizeof(sctp_errhdr_t) + paylen;
126 err.length = htons(len);
127 chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(sctp_errhdr_t), &err);
128}
129
130/* A helper to initialize an op error inside a
131 * provided chunk, as most cause codes will be embedded inside an
132 * abort chunk. Differs from sctp_init_cause in that it won't oops
133 * if there isn't enough space in the op error chunk
134 */
135int sctp_init_cause_fixed(struct sctp_chunk *chunk, __be16 cause_code,
136 size_t paylen)
137{
138 sctp_errhdr_t err;
139 __u16 len;
140
141 /* Cause code constants are now defined in network order. */
142 err.cause = cause_code;
143 len = sizeof(sctp_errhdr_t) + paylen;
144 err.length = htons(len);
145
146 if (skb_tailroom(chunk->skb) < len)
147 return -ENOSPC;
148 chunk->subh.err_hdr = sctp_addto_chunk_fixed(chunk,
149 sizeof(sctp_errhdr_t),
150 &err);
151 return 0;
152}
153/* 3.3.2 Initiation (INIT) (1)
154 *
155 * This chunk is used to initiate a SCTP association between two
156 * endpoints. The format of the INIT chunk is shown below:
157 *
158 * 0 1 2 3
159 * 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
160 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
161 * | Type = 1 | Chunk Flags | Chunk Length |
162 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
163 * | Initiate Tag |
164 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
165 * | Advertised Receiver Window Credit (a_rwnd) |
166 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
167 * | Number of Outbound Streams | Number of Inbound Streams |
168 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
169 * | Initial TSN |
170 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
171 * \ \
172 * / Optional/Variable-Length Parameters /
173 * \ \
174 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
175 *
176 *
177 * The INIT chunk contains the following parameters. Unless otherwise
178 * noted, each parameter MUST only be included once in the INIT chunk.
179 *
180 * Fixed Parameters Status
181 * ----------------------------------------------
182 * Initiate Tag Mandatory
183 * Advertised Receiver Window Credit Mandatory
184 * Number of Outbound Streams Mandatory
185 * Number of Inbound Streams Mandatory
186 * Initial TSN Mandatory
187 *
188 * Variable Parameters Status Type Value
189 * -------------------------------------------------------------
190 * IPv4 Address (Note 1) Optional 5
191 * IPv6 Address (Note 1) Optional 6
192 * Cookie Preservative Optional 9
193 * Reserved for ECN Capable (Note 2) Optional 32768 (0x8000)
194 * Host Name Address (Note 3) Optional 11
195 * Supported Address Types (Note 4) Optional 12
196 */
197struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc,
198 const struct sctp_bind_addr *bp,
199 gfp_t gfp, int vparam_len)
200{
201 sctp_inithdr_t init;
202 union sctp_params addrs;
203 size_t chunksize;
204 struct sctp_chunk *retval = NULL;
205 int num_types, addrs_len = 0;
206 struct sctp_sock *sp;
207 sctp_supported_addrs_param_t sat;
208 __be16 types[2];
209 sctp_adaptation_ind_param_t aiparam;
210 sctp_supported_ext_param_t ext_param;
211 int num_ext = 0;
212 __u8 extensions[3];
213 sctp_paramhdr_t *auth_chunks = NULL,
214 *auth_hmacs = NULL;
215
216 /* RFC 2960 3.3.2 Initiation (INIT) (1)
217 *
218 * Note 1: The INIT chunks can contain multiple addresses that
219 * can be IPv4 and/or IPv6 in any combination.
220 */
221 retval = NULL;
222
223 /* Convert the provided bind address list to raw format. */
224 addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp);
225
226 init.init_tag = htonl(asoc->c.my_vtag);
227 init.a_rwnd = htonl(asoc->rwnd);
228 init.num_outbound_streams = htons(asoc->c.sinit_num_ostreams);
229 init.num_inbound_streams = htons(asoc->c.sinit_max_instreams);
230 init.initial_tsn = htonl(asoc->c.initial_tsn);
231
232 /* How many address types are needed? */
233 sp = sctp_sk(asoc->base.sk);
234 num_types = sp->pf->supported_addrs(sp, types);
235
236 chunksize = sizeof(init) + addrs_len;
237 chunksize += WORD_ROUND(SCTP_SAT_LEN(num_types));
238 chunksize += sizeof(ecap_param);
239
240 if (sctp_prsctp_enable)
241 chunksize += sizeof(prsctp_param);
242
243 /* ADDIP: Section 4.2.7:
244 * An implementation supporting this extension [ADDIP] MUST list
245 * the ASCONF,the ASCONF-ACK, and the AUTH chunks in its INIT and
246 * INIT-ACK parameters.
247 */
248 if (sctp_addip_enable) {
249 extensions[num_ext] = SCTP_CID_ASCONF;
250 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
251 num_ext += 2;
252 }
253
254 if (sp->adaptation_ind)
255 chunksize += sizeof(aiparam);
256
257 chunksize += vparam_len;
258
259 /* Account for AUTH related parameters */
260 if (sctp_auth_enable) {
261 /* Add random parameter length*/
262 chunksize += sizeof(asoc->c.auth_random);
263
264 /* Add HMACS parameter length if any were defined */
265 auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs;
266 if (auth_hmacs->length)
267 chunksize += WORD_ROUND(ntohs(auth_hmacs->length));
268 else
269 auth_hmacs = NULL;
270
271 /* Add CHUNKS parameter length */
272 auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks;
273 if (auth_chunks->length)
274 chunksize += WORD_ROUND(ntohs(auth_chunks->length));
275 else
276 auth_chunks = NULL;
277
278 extensions[num_ext] = SCTP_CID_AUTH;
279 num_ext += 1;
280 }
281
282 /* If we have any extensions to report, account for that */
283 if (num_ext)
284 chunksize += WORD_ROUND(sizeof(sctp_supported_ext_param_t) +
285 num_ext);
286
287 /* RFC 2960 3.3.2 Initiation (INIT) (1)
288 *
289 * Note 3: An INIT chunk MUST NOT contain more than one Host
290 * Name address parameter. Moreover, the sender of the INIT
291 * MUST NOT combine any other address types with the Host Name
292 * address in the INIT. The receiver of INIT MUST ignore any
293 * other address types if the Host Name address parameter is
294 * present in the received INIT chunk.
295 *
296 * PLEASE DO NOT FIXME [This version does not support Host Name.]
297 */
298
299 retval = sctp_make_chunk(asoc, SCTP_CID_INIT, 0, chunksize);
300 if (!retval)
301 goto nodata;
302
303 retval->subh.init_hdr =
304 sctp_addto_chunk(retval, sizeof(init), &init);
305 retval->param_hdr.v =
306 sctp_addto_chunk(retval, addrs_len, addrs.v);
307
308 /* RFC 2960 3.3.2 Initiation (INIT) (1)
309 *
310 * Note 4: This parameter, when present, specifies all the
311 * address types the sending endpoint can support. The absence
312 * of this parameter indicates that the sending endpoint can
313 * support any address type.
314 */
315 sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES;
316 sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types));
317 sctp_addto_chunk(retval, sizeof(sat), &sat);
318 sctp_addto_chunk(retval, num_types * sizeof(__u16), &types);
319
320 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
321
322 /* Add the supported extensions parameter. Be nice and add this
323 * fist before addiding the parameters for the extensions themselves
324 */
325 if (num_ext) {
326 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
327 ext_param.param_hdr.length =
328 htons(sizeof(sctp_supported_ext_param_t) + num_ext);
329 sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t),
330 &ext_param);
331 sctp_addto_param(retval, num_ext, extensions);
332 }
333
334 if (sctp_prsctp_enable)
335 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
336
337 if (sp->adaptation_ind) {
338 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
339 aiparam.param_hdr.length = htons(sizeof(aiparam));
340 aiparam.adaptation_ind = htonl(sp->adaptation_ind);
341 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
342 }
343
344 /* Add SCTP-AUTH chunks to the parameter list */
345 if (sctp_auth_enable) {
346 sctp_addto_chunk(retval, sizeof(asoc->c.auth_random),
347 asoc->c.auth_random);
348 if (auth_hmacs)
349 sctp_addto_chunk(retval, ntohs(auth_hmacs->length),
350 auth_hmacs);
351 if (auth_chunks)
352 sctp_addto_chunk(retval, ntohs(auth_chunks->length),
353 auth_chunks);
354 }
355nodata:
356 kfree(addrs.v);
357 return retval;
358}
359
360struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc,
361 const struct sctp_chunk *chunk,
362 gfp_t gfp, int unkparam_len)
363{
364 sctp_inithdr_t initack;
365 struct sctp_chunk *retval;
366 union sctp_params addrs;
367 struct sctp_sock *sp;
368 int addrs_len;
369 sctp_cookie_param_t *cookie;
370 int cookie_len;
371 size_t chunksize;
372 sctp_adaptation_ind_param_t aiparam;
373 sctp_supported_ext_param_t ext_param;
374 int num_ext = 0;
375 __u8 extensions[3];
376 sctp_paramhdr_t *auth_chunks = NULL,
377 *auth_hmacs = NULL,
378 *auth_random = NULL;
379
380 retval = NULL;
381
382 /* Note: there may be no addresses to embed. */
383 addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp);
384
385 initack.init_tag = htonl(asoc->c.my_vtag);
386 initack.a_rwnd = htonl(asoc->rwnd);
387 initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams);
388 initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams);
389 initack.initial_tsn = htonl(asoc->c.initial_tsn);
390
391 /* FIXME: We really ought to build the cookie right
392 * into the packet instead of allocating more fresh memory.
393 */
394 cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len,
395 addrs.v, addrs_len);
396 if (!cookie)
397 goto nomem_cookie;
398
399 /* Calculate the total size of allocation, include the reserved
400 * space for reporting unknown parameters if it is specified.
401 */
402 sp = sctp_sk(asoc->base.sk);
403 chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len;
404
405 /* Tell peer that we'll do ECN only if peer advertised such cap. */
406 if (asoc->peer.ecn_capable)
407 chunksize += sizeof(ecap_param);
408
409 if (asoc->peer.prsctp_capable)
410 chunksize += sizeof(prsctp_param);
411
412 if (asoc->peer.asconf_capable) {
413 extensions[num_ext] = SCTP_CID_ASCONF;
414 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
415 num_ext += 2;
416 }
417
418 if (sp->adaptation_ind)
419 chunksize += sizeof(aiparam);
420
421 if (asoc->peer.auth_capable) {
422 auth_random = (sctp_paramhdr_t *)asoc->c.auth_random;
423 chunksize += ntohs(auth_random->length);
424
425 auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs;
426 if (auth_hmacs->length)
427 chunksize += WORD_ROUND(ntohs(auth_hmacs->length));
428 else
429 auth_hmacs = NULL;
430
431 auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks;
432 if (auth_chunks->length)
433 chunksize += WORD_ROUND(ntohs(auth_chunks->length));
434 else
435 auth_chunks = NULL;
436
437 extensions[num_ext] = SCTP_CID_AUTH;
438 num_ext += 1;
439 }
440
441 if (num_ext)
442 chunksize += WORD_ROUND(sizeof(sctp_supported_ext_param_t) +
443 num_ext);
444
445 /* Now allocate and fill out the chunk. */
446 retval = sctp_make_chunk(asoc, SCTP_CID_INIT_ACK, 0, chunksize);
447 if (!retval)
448 goto nomem_chunk;
449
450 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
451 *
452 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
453 * HEARTBEAT ACK, * etc.) to the same destination transport
454 * address from which it received the DATA or control chunk
455 * to which it is replying.
456 *
457 * [INIT ACK back to where the INIT came from.]
458 */
459 retval->transport = chunk->transport;
460
461 retval->subh.init_hdr =
462 sctp_addto_chunk(retval, sizeof(initack), &initack);
463 retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v);
464 sctp_addto_chunk(retval, cookie_len, cookie);
465 if (asoc->peer.ecn_capable)
466 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
467 if (num_ext) {
468 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
469 ext_param.param_hdr.length =
470 htons(sizeof(sctp_supported_ext_param_t) + num_ext);
471 sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t),
472 &ext_param);
473 sctp_addto_param(retval, num_ext, extensions);
474 }
475 if (asoc->peer.prsctp_capable)
476 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
477
478 if (sp->adaptation_ind) {
479 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
480 aiparam.param_hdr.length = htons(sizeof(aiparam));
481 aiparam.adaptation_ind = htonl(sp->adaptation_ind);
482 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
483 }
484
485 if (asoc->peer.auth_capable) {
486 sctp_addto_chunk(retval, ntohs(auth_random->length),
487 auth_random);
488 if (auth_hmacs)
489 sctp_addto_chunk(retval, ntohs(auth_hmacs->length),
490 auth_hmacs);
491 if (auth_chunks)
492 sctp_addto_chunk(retval, ntohs(auth_chunks->length),
493 auth_chunks);
494 }
495
496 /* We need to remove the const qualifier at this point. */
497 retval->asoc = (struct sctp_association *) asoc;
498
499nomem_chunk:
500 kfree(cookie);
501nomem_cookie:
502 kfree(addrs.v);
503 return retval;
504}
505
506/* 3.3.11 Cookie Echo (COOKIE ECHO) (10):
507 *
508 * This chunk is used only during the initialization of an association.
509 * It is sent by the initiator of an association to its peer to complete
510 * the initialization process. This chunk MUST precede any DATA chunk
511 * sent within the association, but MAY be bundled with one or more DATA
512 * chunks in the same packet.
513 *
514 * 0 1 2 3
515 * 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
516 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
517 * | Type = 10 |Chunk Flags | Length |
518 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
519 * / Cookie /
520 * \ \
521 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
522 *
523 * Chunk Flags: 8 bit
524 *
525 * Set to zero on transmit and ignored on receipt.
526 *
527 * Length: 16 bits (unsigned integer)
528 *
529 * Set to the size of the chunk in bytes, including the 4 bytes of
530 * the chunk header and the size of the Cookie.
531 *
532 * Cookie: variable size
533 *
534 * This field must contain the exact cookie received in the
535 * State Cookie parameter from the previous INIT ACK.
536 *
537 * An implementation SHOULD make the cookie as small as possible
538 * to insure interoperability.
539 */
540struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc,
541 const struct sctp_chunk *chunk)
542{
543 struct sctp_chunk *retval;
544 void *cookie;
545 int cookie_len;
546
547 cookie = asoc->peer.cookie;
548 cookie_len = asoc->peer.cookie_len;
549
550 /* Build a cookie echo chunk. */
551 retval = sctp_make_chunk(asoc, SCTP_CID_COOKIE_ECHO, 0, cookie_len);
552 if (!retval)
553 goto nodata;
554 retval->subh.cookie_hdr =
555 sctp_addto_chunk(retval, cookie_len, cookie);
556
557 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
558 *
559 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
560 * HEARTBEAT ACK, * etc.) to the same destination transport
561 * address from which it * received the DATA or control chunk
562 * to which it is replying.
563 *
564 * [COOKIE ECHO back to where the INIT ACK came from.]
565 */
566 if (chunk)
567 retval->transport = chunk->transport;
568
569nodata:
570 return retval;
571}
572
573/* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11):
574 *
575 * This chunk is used only during the initialization of an
576 * association. It is used to acknowledge the receipt of a COOKIE
577 * ECHO chunk. This chunk MUST precede any DATA or SACK chunk sent
578 * within the association, but MAY be bundled with one or more DATA
579 * chunks or SACK chunk in the same SCTP packet.
580 *
581 * 0 1 2 3
582 * 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
583 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
584 * | Type = 11 |Chunk Flags | Length = 4 |
585 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
586 *
587 * Chunk Flags: 8 bits
588 *
589 * Set to zero on transmit and ignored on receipt.
590 */
591struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc,
592 const struct sctp_chunk *chunk)
593{
594 struct sctp_chunk *retval;
595
596 retval = sctp_make_chunk(asoc, SCTP_CID_COOKIE_ACK, 0, 0);
597
598 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
599 *
600 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
601 * HEARTBEAT ACK, * etc.) to the same destination transport
602 * address from which it * received the DATA or control chunk
603 * to which it is replying.
604 *
605 * [COOKIE ACK back to where the COOKIE ECHO came from.]
606 */
607 if (retval && chunk)
608 retval->transport = chunk->transport;
609
610 return retval;
611}
612
613/*
614 * Appendix A: Explicit Congestion Notification:
615 * CWR:
616 *
617 * RFC 2481 details a specific bit for a sender to send in the header of
618 * its next outbound TCP segment to indicate to its peer that it has
619 * reduced its congestion window. This is termed the CWR bit. For
620 * SCTP the same indication is made by including the CWR chunk.
621 * This chunk contains one data element, i.e. the TSN number that
622 * was sent in the ECNE chunk. This element represents the lowest
623 * TSN number in the datagram that was originally marked with the
624 * CE bit.
625 *
626 * 0 1 2 3
627 * 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
628 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
629 * | Chunk Type=13 | Flags=00000000| Chunk Length = 8 |
630 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
631 * | Lowest TSN Number |
632 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
633 *
634 * Note: The CWR is considered a Control chunk.
635 */
636struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc,
637 const __u32 lowest_tsn,
638 const struct sctp_chunk *chunk)
639{
640 struct sctp_chunk *retval;
641 sctp_cwrhdr_t cwr;
642
643 cwr.lowest_tsn = htonl(lowest_tsn);
644 retval = sctp_make_chunk(asoc, SCTP_CID_ECN_CWR, 0,
645 sizeof(sctp_cwrhdr_t));
646
647 if (!retval)
648 goto nodata;
649
650 retval->subh.ecn_cwr_hdr =
651 sctp_addto_chunk(retval, sizeof(cwr), &cwr);
652
653 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
654 *
655 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
656 * HEARTBEAT ACK, * etc.) to the same destination transport
657 * address from which it * received the DATA or control chunk
658 * to which it is replying.
659 *
660 * [Report a reduced congestion window back to where the ECNE
661 * came from.]
662 */
663 if (chunk)
664 retval->transport = chunk->transport;
665
666nodata:
667 return retval;
668}
669
670/* Make an ECNE chunk. This is a congestion experienced report. */
671struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc,
672 const __u32 lowest_tsn)
673{
674 struct sctp_chunk *retval;
675 sctp_ecnehdr_t ecne;
676
677 ecne.lowest_tsn = htonl(lowest_tsn);
678 retval = sctp_make_chunk(asoc, SCTP_CID_ECN_ECNE, 0,
679 sizeof(sctp_ecnehdr_t));
680 if (!retval)
681 goto nodata;
682 retval->subh.ecne_hdr =
683 sctp_addto_chunk(retval, sizeof(ecne), &ecne);
684
685nodata:
686 return retval;
687}
688
689/* Make a DATA chunk for the given association from the provided
690 * parameters. However, do not populate the data payload.
691 */
692struct sctp_chunk *sctp_make_datafrag_empty(struct sctp_association *asoc,
693 const struct sctp_sndrcvinfo *sinfo,
694 int data_len, __u8 flags, __u16 ssn)
695{
696 struct sctp_chunk *retval;
697 struct sctp_datahdr dp;
698 int chunk_len;
699
700 /* We assign the TSN as LATE as possible, not here when
701 * creating the chunk.
702 */
703 dp.tsn = 0;
704 dp.stream = htons(sinfo->sinfo_stream);
705 dp.ppid = sinfo->sinfo_ppid;
706
707 /* Set the flags for an unordered send. */
708 if (sinfo->sinfo_flags & SCTP_UNORDERED) {
709 flags |= SCTP_DATA_UNORDERED;
710 dp.ssn = 0;
711 } else
712 dp.ssn = htons(ssn);
713
714 chunk_len = sizeof(dp) + data_len;
715 retval = sctp_make_chunk(asoc, SCTP_CID_DATA, flags, chunk_len);
716 if (!retval)
717 goto nodata;
718
719 retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp);
720 memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo));
721
722nodata:
723 return retval;
724}
725
726/* Create a selective ackowledgement (SACK) for the given
727 * association. This reports on which TSN's we've seen to date,
728 * including duplicates and gaps.
729 */
730struct sctp_chunk *sctp_make_sack(const struct sctp_association *asoc)
731{
732 struct sctp_chunk *retval;
733 struct sctp_sackhdr sack;
734 int len;
735 __u32 ctsn;
736 __u16 num_gabs, num_dup_tsns;
737 struct sctp_association *aptr = (struct sctp_association *)asoc;
738 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
739 struct sctp_gap_ack_block gabs[SCTP_MAX_GABS];
740 struct sctp_transport *trans;
741
742 memset(gabs, 0, sizeof(gabs));
743 ctsn = sctp_tsnmap_get_ctsn(map);
744 SCTP_DEBUG_PRINTK("sackCTSNAck sent: 0x%x.\n", ctsn);
745
746 /* How much room is needed in the chunk? */
747 num_gabs = sctp_tsnmap_num_gabs(map, gabs);
748 num_dup_tsns = sctp_tsnmap_num_dups(map);
749
750 /* Initialize the SACK header. */
751 sack.cum_tsn_ack = htonl(ctsn);
752 sack.a_rwnd = htonl(asoc->a_rwnd);
753 sack.num_gap_ack_blocks = htons(num_gabs);
754 sack.num_dup_tsns = htons(num_dup_tsns);
755
756 len = sizeof(sack)
757 + sizeof(struct sctp_gap_ack_block) * num_gabs
758 + sizeof(__u32) * num_dup_tsns;
759
760 /* Create the chunk. */
761 retval = sctp_make_chunk(asoc, SCTP_CID_SACK, 0, len);
762 if (!retval)
763 goto nodata;
764
765 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
766 *
767 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
768 * HEARTBEAT ACK, etc.) to the same destination transport
769 * address from which it received the DATA or control chunk to
770 * which it is replying. This rule should also be followed if
771 * the endpoint is bundling DATA chunks together with the
772 * reply chunk.
773 *
774 * However, when acknowledging multiple DATA chunks received
775 * in packets from different source addresses in a single
776 * SACK, the SACK chunk may be transmitted to one of the
777 * destination transport addresses from which the DATA or
778 * control chunks being acknowledged were received.
779 *
780 * [BUG: We do not implement the following paragraph.
781 * Perhaps we should remember the last transport we used for a
782 * SACK and avoid that (if possible) if we have seen any
783 * duplicates. --piggy]
784 *
785 * When a receiver of a duplicate DATA chunk sends a SACK to a
786 * multi- homed endpoint it MAY be beneficial to vary the
787 * destination address and not use the source address of the
788 * DATA chunk. The reason being that receiving a duplicate
789 * from a multi-homed endpoint might indicate that the return
790 * path (as specified in the source address of the DATA chunk)
791 * for the SACK is broken.
792 *
793 * [Send to the address from which we last received a DATA chunk.]
794 */
795 retval->transport = asoc->peer.last_data_from;
796
797 retval->subh.sack_hdr =
798 sctp_addto_chunk(retval, sizeof(sack), &sack);
799
800 /* Add the gap ack block information. */
801 if (num_gabs)
802 sctp_addto_chunk(retval, sizeof(__u32) * num_gabs,
803 gabs);
804
805 /* Add the duplicate TSN information. */
806 if (num_dup_tsns)
807 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns,
808 sctp_tsnmap_get_dups(map));
809
810 /* Once we have a sack generated, check to see what our sack
811 * generation is, if its 0, reset the transports to 0, and reset
812 * the association generation to 1
813 *
814 * The idea is that zero is never used as a valid generation for the
815 * association so no transport will match after a wrap event like this,
816 * Until the next sack
817 */
818 if (++aptr->peer.sack_generation == 0) {
819 list_for_each_entry(trans, &asoc->peer.transport_addr_list,
820 transports)
821 trans->sack_generation = 0;
822 aptr->peer.sack_generation = 1;
823 }
824nodata:
825 return retval;
826}
827
828/* Make a SHUTDOWN chunk. */
829struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc,
830 const struct sctp_chunk *chunk)
831{
832 struct sctp_chunk *retval;
833 sctp_shutdownhdr_t shut;
834 __u32 ctsn;
835
836 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
837 shut.cum_tsn_ack = htonl(ctsn);
838
839 retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN, 0,
840 sizeof(sctp_shutdownhdr_t));
841 if (!retval)
842 goto nodata;
843
844 retval->subh.shutdown_hdr =
845 sctp_addto_chunk(retval, sizeof(shut), &shut);
846
847 if (chunk)
848 retval->transport = chunk->transport;
849nodata:
850 return retval;
851}
852
853struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc,
854 const struct sctp_chunk *chunk)
855{
856 struct sctp_chunk *retval;
857
858 retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0);
859
860 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
861 *
862 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
863 * HEARTBEAT ACK, * etc.) to the same destination transport
864 * address from which it * received the DATA or control chunk
865 * to which it is replying.
866 *
867 * [ACK back to where the SHUTDOWN came from.]
868 */
869 if (retval && chunk)
870 retval->transport = chunk->transport;
871
872 return retval;
873}
874
875struct sctp_chunk *sctp_make_shutdown_complete(
876 const struct sctp_association *asoc,
877 const struct sctp_chunk *chunk)
878{
879 struct sctp_chunk *retval;
880 __u8 flags = 0;
881
882 /* Set the T-bit if we have no association (vtag will be
883 * reflected)
884 */
885 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T;
886
887 retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 0);
888
889 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
890 *
891 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
892 * HEARTBEAT ACK, * etc.) to the same destination transport
893 * address from which it * received the DATA or control chunk
894 * to which it is replying.
895 *
896 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK
897 * came from.]
898 */
899 if (retval && chunk)
900 retval->transport = chunk->transport;
901
902 return retval;
903}
904
905/* Create an ABORT. Note that we set the T bit if we have no
906 * association, except when responding to an INIT (sctpimpguide 2.41).
907 */
908struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc,
909 const struct sctp_chunk *chunk,
910 const size_t hint)
911{
912 struct sctp_chunk *retval;
913 __u8 flags = 0;
914
915 /* Set the T-bit if we have no association and 'chunk' is not
916 * an INIT (vtag will be reflected).
917 */
918 if (!asoc) {
919 if (chunk && chunk->chunk_hdr &&
920 chunk->chunk_hdr->type == SCTP_CID_INIT)
921 flags = 0;
922 else
923 flags = SCTP_CHUNK_FLAG_T;
924 }
925
926 retval = sctp_make_chunk(asoc, SCTP_CID_ABORT, flags, hint);
927
928 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
929 *
930 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
931 * HEARTBEAT ACK, * etc.) to the same destination transport
932 * address from which it * received the DATA or control chunk
933 * to which it is replying.
934 *
935 * [ABORT back to where the offender came from.]
936 */
937 if (retval && chunk)
938 retval->transport = chunk->transport;
939
940 return retval;
941}
942
943/* Helper to create ABORT with a NO_USER_DATA error. */
944struct sctp_chunk *sctp_make_abort_no_data(
945 const struct sctp_association *asoc,
946 const struct sctp_chunk *chunk, __u32 tsn)
947{
948 struct sctp_chunk *retval;
949 __be32 payload;
950
951 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t)
952 + sizeof(tsn));
953
954 if (!retval)
955 goto no_mem;
956
957 /* Put the tsn back into network byte order. */
958 payload = htonl(tsn);
959 sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload));
960 sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload);
961
962 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
963 *
964 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
965 * HEARTBEAT ACK, * etc.) to the same destination transport
966 * address from which it * received the DATA or control chunk
967 * to which it is replying.
968 *
969 * [ABORT back to where the offender came from.]
970 */
971 if (chunk)
972 retval->transport = chunk->transport;
973
974no_mem:
975 return retval;
976}
977
978/* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */
979struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc,
980 const struct msghdr *msg,
981 size_t paylen)
982{
983 struct sctp_chunk *retval;
984 void *payload = NULL;
985 int err;
986
987 retval = sctp_make_abort(asoc, NULL, sizeof(sctp_errhdr_t) + paylen);
988 if (!retval)
989 goto err_chunk;
990
991 if (paylen) {
992 /* Put the msg_iov together into payload. */
993 payload = kmalloc(paylen, GFP_KERNEL);
994 if (!payload)
995 goto err_payload;
996
997 err = memcpy_fromiovec(payload, msg->msg_iov, paylen);
998 if (err < 0)
999 goto err_copy;
1000 }
1001
1002 sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen);
1003 sctp_addto_chunk(retval, paylen, payload);
1004
1005 if (paylen)
1006 kfree(payload);
1007
1008 return retval;
1009
1010err_copy:
1011 kfree(payload);
1012err_payload:
1013 sctp_chunk_free(retval);
1014 retval = NULL;
1015err_chunk:
1016 return retval;
1017}
1018
1019/* Append bytes to the end of a parameter. Will panic if chunk is not big
1020 * enough.
1021 */
1022static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
1023 const void *data)
1024{
1025 void *target;
1026 int chunklen = ntohs(chunk->chunk_hdr->length);
1027
1028 target = skb_put(chunk->skb, len);
1029
1030 if (data)
1031 memcpy(target, data, len);
1032 else
1033 memset(target, 0, len);
1034
1035 /* Adjust the chunk length field. */
1036 chunk->chunk_hdr->length = htons(chunklen + len);
1037 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1038
1039 return target;
1040}
1041
1042/* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */
1043struct sctp_chunk *sctp_make_abort_violation(
1044 const struct sctp_association *asoc,
1045 const struct sctp_chunk *chunk,
1046 const __u8 *payload,
1047 const size_t paylen)
1048{
1049 struct sctp_chunk *retval;
1050 struct sctp_paramhdr phdr;
1051
1052 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) + paylen
1053 + sizeof(sctp_paramhdr_t));
1054 if (!retval)
1055 goto end;
1056
1057 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen
1058 + sizeof(sctp_paramhdr_t));
1059
1060 phdr.type = htons(chunk->chunk_hdr->type);
1061 phdr.length = chunk->chunk_hdr->length;
1062 sctp_addto_chunk(retval, paylen, payload);
1063 sctp_addto_param(retval, sizeof(sctp_paramhdr_t), &phdr);
1064
1065end:
1066 return retval;
1067}
1068
1069struct sctp_chunk *sctp_make_violation_paramlen(
1070 const struct sctp_association *asoc,
1071 const struct sctp_chunk *chunk,
1072 struct sctp_paramhdr *param)
1073{
1074 struct sctp_chunk *retval;
1075 static const char error[] = "The following parameter had invalid length:";
1076 size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t) +
1077 sizeof(sctp_paramhdr_t);
1078
1079 retval = sctp_make_abort(asoc, chunk, payload_len);
1080 if (!retval)
1081 goto nodata;
1082
1083 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION,
1084 sizeof(error) + sizeof(sctp_paramhdr_t));
1085 sctp_addto_chunk(retval, sizeof(error), error);
1086 sctp_addto_param(retval, sizeof(sctp_paramhdr_t), param);
1087
1088nodata:
1089 return retval;
1090}
1091
1092/* Make a HEARTBEAT chunk. */
1093struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc,
1094 const struct sctp_transport *transport)
1095{
1096 struct sctp_chunk *retval;
1097 sctp_sender_hb_info_t hbinfo;
1098
1099 retval = sctp_make_chunk(asoc, SCTP_CID_HEARTBEAT, 0, sizeof(hbinfo));
1100
1101 if (!retval)
1102 goto nodata;
1103
1104 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO;
1105 hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t));
1106 hbinfo.daddr = transport->ipaddr;
1107 hbinfo.sent_at = jiffies;
1108 hbinfo.hb_nonce = transport->hb_nonce;
1109
1110 /* Cast away the 'const', as this is just telling the chunk
1111 * what transport it belongs to.
1112 */
1113 retval->transport = (struct sctp_transport *) transport;
1114 retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo),
1115 &hbinfo);
1116
1117nodata:
1118 return retval;
1119}
1120
1121struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc,
1122 const struct sctp_chunk *chunk,
1123 const void *payload, const size_t paylen)
1124{
1125 struct sctp_chunk *retval;
1126
1127 retval = sctp_make_chunk(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen);
1128 if (!retval)
1129 goto nodata;
1130
1131 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload);
1132
1133 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
1134 *
1135 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1136 * HEARTBEAT ACK, * etc.) to the same destination transport
1137 * address from which it * received the DATA or control chunk
1138 * to which it is replying.
1139 *
1140 * [HBACK back to where the HEARTBEAT came from.]
1141 */
1142 if (chunk)
1143 retval->transport = chunk->transport;
1144
1145nodata:
1146 return retval;
1147}
1148
1149/* Create an Operation Error chunk with the specified space reserved.
1150 * This routine can be used for containing multiple causes in the chunk.
1151 */
1152static struct sctp_chunk *sctp_make_op_error_space(
1153 const struct sctp_association *asoc,
1154 const struct sctp_chunk *chunk,
1155 size_t size)
1156{
1157 struct sctp_chunk *retval;
1158
1159 retval = sctp_make_chunk(asoc, SCTP_CID_ERROR, 0,
1160 sizeof(sctp_errhdr_t) + size);
1161 if (!retval)
1162 goto nodata;
1163
1164 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
1165 *
1166 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1167 * HEARTBEAT ACK, etc.) to the same destination transport
1168 * address from which it received the DATA or control chunk
1169 * to which it is replying.
1170 *
1171 */
1172 if (chunk)
1173 retval->transport = chunk->transport;
1174
1175nodata:
1176 return retval;
1177}
1178
1179/* Create an Operation Error chunk of a fixed size,
1180 * specifically, max(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT)
1181 * This is a helper function to allocate an error chunk for
1182 * for those invalid parameter codes in which we may not want
1183 * to report all the errors, if the incomming chunk is large
1184 */
1185static inline struct sctp_chunk *sctp_make_op_error_fixed(
1186 const struct sctp_association *asoc,
1187 const struct sctp_chunk *chunk)
1188{
1189 size_t size = asoc ? asoc->pathmtu : 0;
1190
1191 if (!size)
1192 size = SCTP_DEFAULT_MAXSEGMENT;
1193
1194 return sctp_make_op_error_space(asoc, chunk, size);
1195}
1196
1197/* Create an Operation Error chunk. */
1198struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc,
1199 const struct sctp_chunk *chunk,
1200 __be16 cause_code, const void *payload,
1201 size_t paylen, size_t reserve_tail)
1202{
1203 struct sctp_chunk *retval;
1204
1205 retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail);
1206 if (!retval)
1207 goto nodata;
1208
1209 sctp_init_cause(retval, cause_code, paylen + reserve_tail);
1210 sctp_addto_chunk(retval, paylen, payload);
1211 if (reserve_tail)
1212 sctp_addto_param(retval, reserve_tail, NULL);
1213
1214nodata:
1215 return retval;
1216}
1217
1218struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc)
1219{
1220 struct sctp_chunk *retval;
1221 struct sctp_hmac *hmac_desc;
1222 struct sctp_authhdr auth_hdr;
1223 __u8 *hmac;
1224
1225 /* Get the first hmac that the peer told us to use */
1226 hmac_desc = sctp_auth_asoc_get_hmac(asoc);
1227 if (unlikely(!hmac_desc))
1228 return NULL;
1229
1230 retval = sctp_make_chunk(asoc, SCTP_CID_AUTH, 0,
1231 hmac_desc->hmac_len + sizeof(sctp_authhdr_t));
1232 if (!retval)
1233 return NULL;
1234
1235 auth_hdr.hmac_id = htons(hmac_desc->hmac_id);
1236 auth_hdr.shkey_id = htons(asoc->active_key_id);
1237
1238 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(sctp_authhdr_t),
1239 &auth_hdr);
1240
1241 hmac = skb_put(retval->skb, hmac_desc->hmac_len);
1242 memset(hmac, 0, hmac_desc->hmac_len);
1243
1244 /* Adjust the chunk header to include the empty MAC */
1245 retval->chunk_hdr->length =
1246 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len);
1247 retval->chunk_end = skb_tail_pointer(retval->skb);
1248
1249 return retval;
1250}
1251
1252
1253/********************************************************************
1254 * 2nd Level Abstractions
1255 ********************************************************************/
1256
1257/* Turn an skb into a chunk.
1258 * FIXME: Eventually move the structure directly inside the skb->cb[].
1259 */
1260struct sctp_chunk *sctp_chunkify(struct sk_buff *skb,
1261 const struct sctp_association *asoc,
1262 struct sock *sk)
1263{
1264 struct sctp_chunk *retval;
1265
1266 retval = kmem_cache_zalloc(sctp_chunk_cachep, GFP_ATOMIC);
1267
1268 if (!retval)
1269 goto nodata;
1270
1271 if (!sk) {
1272 SCTP_DEBUG_PRINTK("chunkifying skb %p w/o an sk\n", skb);
1273 }
1274
1275 INIT_LIST_HEAD(&retval->list);
1276 retval->skb = skb;
1277 retval->asoc = (struct sctp_association *)asoc;
1278 retval->has_tsn = 0;
1279 retval->has_ssn = 0;
1280 retval->rtt_in_progress = 0;
1281 retval->sent_at = 0;
1282 retval->singleton = 1;
1283 retval->end_of_packet = 0;
1284 retval->ecn_ce_done = 0;
1285 retval->pdiscard = 0;
1286
1287 /* sctpimpguide-05.txt Section 2.8.2
1288 * M1) Each time a new DATA chunk is transmitted
1289 * set the 'TSN.Missing.Report' count for that TSN to 0. The
1290 * 'TSN.Missing.Report' count will be used to determine missing chunks
1291 * and when to fast retransmit.
1292 */
1293 retval->tsn_missing_report = 0;
1294 retval->tsn_gap_acked = 0;
1295 retval->fast_retransmit = SCTP_CAN_FRTX;
1296
1297 /* If this is a fragmented message, track all fragments
1298 * of the message (for SEND_FAILED).
1299 */
1300 retval->msg = NULL;
1301
1302 /* Polish the bead hole. */
1303 INIT_LIST_HEAD(&retval->transmitted_list);
1304 INIT_LIST_HEAD(&retval->frag_list);
1305 SCTP_DBG_OBJCNT_INC(chunk);
1306 atomic_set(&retval->refcnt, 1);
1307
1308nodata:
1309 return retval;
1310}
1311
1312/* Set chunk->source and dest based on the IP header in chunk->skb. */
1313void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src,
1314 union sctp_addr *dest)
1315{
1316 memcpy(&chunk->source, src, sizeof(union sctp_addr));
1317 memcpy(&chunk->dest, dest, sizeof(union sctp_addr));
1318}
1319
1320/* Extract the source address from a chunk. */
1321const union sctp_addr *sctp_source(const struct sctp_chunk *chunk)
1322{
1323 /* If we have a known transport, use that. */
1324 if (chunk->transport) {
1325 return &chunk->transport->ipaddr;
1326 } else {
1327 /* Otherwise, extract it from the IP header. */
1328 return &chunk->source;
1329 }
1330}
1331
1332/* Create a new chunk, setting the type and flags headers from the
1333 * arguments, reserving enough space for a 'paylen' byte payload.
1334 */
1335SCTP_STATIC
1336struct sctp_chunk *sctp_make_chunk(const struct sctp_association *asoc,
1337 __u8 type, __u8 flags, int paylen)
1338{
1339 struct sctp_chunk *retval;
1340 sctp_chunkhdr_t *chunk_hdr;
1341 struct sk_buff *skb;
1342 struct sock *sk;
1343
1344 /* No need to allocate LL here, as this is only a chunk. */
1345 skb = alloc_skb(WORD_ROUND(sizeof(sctp_chunkhdr_t) + paylen),
1346 GFP_ATOMIC);
1347 if (!skb)
1348 goto nodata;
1349
1350 /* Make room for the chunk header. */
1351 chunk_hdr = (sctp_chunkhdr_t *)skb_put(skb, sizeof(sctp_chunkhdr_t));
1352 chunk_hdr->type = type;
1353 chunk_hdr->flags = flags;
1354 chunk_hdr->length = htons(sizeof(sctp_chunkhdr_t));
1355
1356 sk = asoc ? asoc->base.sk : NULL;
1357 retval = sctp_chunkify(skb, asoc, sk);
1358 if (!retval) {
1359 kfree_skb(skb);
1360 goto nodata;
1361 }
1362
1363 retval->chunk_hdr = chunk_hdr;
1364 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(struct sctp_chunkhdr);
1365
1366 /* Determine if the chunk needs to be authenticated */
1367 if (sctp_auth_send_cid(type, asoc))
1368 retval->auth = 1;
1369
1370 /* Set the skb to the belonging sock for accounting. */
1371 skb->sk = sk;
1372
1373 return retval;
1374nodata:
1375 return NULL;
1376}
1377
1378
1379/* Release the memory occupied by a chunk. */
1380static void sctp_chunk_destroy(struct sctp_chunk *chunk)
1381{
1382 BUG_ON(!list_empty(&chunk->list));
1383 list_del_init(&chunk->transmitted_list);
1384
1385 /* Free the chunk skb data and the SCTP_chunk stub itself. */
1386 dev_kfree_skb(chunk->skb);
1387
1388 SCTP_DBG_OBJCNT_DEC(chunk);
1389 kmem_cache_free(sctp_chunk_cachep, chunk);
1390}
1391
1392/* Possibly, free the chunk. */
1393void sctp_chunk_free(struct sctp_chunk *chunk)
1394{
1395 /* Release our reference on the message tracker. */
1396 if (chunk->msg)
1397 sctp_datamsg_put(chunk->msg);
1398
1399 sctp_chunk_put(chunk);
1400}
1401
1402/* Grab a reference to the chunk. */
1403void sctp_chunk_hold(struct sctp_chunk *ch)
1404{
1405 atomic_inc(&ch->refcnt);
1406}
1407
1408/* Release a reference to the chunk. */
1409void sctp_chunk_put(struct sctp_chunk *ch)
1410{
1411 if (atomic_dec_and_test(&ch->refcnt))
1412 sctp_chunk_destroy(ch);
1413}
1414
1415/* Append bytes to the end of a chunk. Will panic if chunk is not big
1416 * enough.
1417 */
1418void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data)
1419{
1420 void *target;
1421 void *padding;
1422 int chunklen = ntohs(chunk->chunk_hdr->length);
1423 int padlen = WORD_ROUND(chunklen) - chunklen;
1424
1425 padding = skb_put(chunk->skb, padlen);
1426 target = skb_put(chunk->skb, len);
1427
1428 memset(padding, 0, padlen);
1429 memcpy(target, data, len);
1430
1431 /* Adjust the chunk length field. */
1432 chunk->chunk_hdr->length = htons(chunklen + padlen + len);
1433 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1434
1435 return target;
1436}
1437
1438/* Append bytes to the end of a chunk. Returns NULL if there isn't sufficient
1439 * space in the chunk
1440 */
1441void *sctp_addto_chunk_fixed(struct sctp_chunk *chunk,
1442 int len, const void *data)
1443{
1444 if (skb_tailroom(chunk->skb) >= len)
1445 return sctp_addto_chunk(chunk, len, data);
1446 else
1447 return NULL;
1448}
1449
1450/* Append bytes from user space to the end of a chunk. Will panic if
1451 * chunk is not big enough.
1452 * Returns a kernel err value.
1453 */
1454int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len,
1455 struct iovec *data)
1456{
1457 __u8 *target;
1458 int err = 0;
1459
1460 /* Make room in chunk for data. */
1461 target = skb_put(chunk->skb, len);
1462
1463 /* Copy data (whole iovec) into chunk */
1464 if ((err = memcpy_fromiovecend(target, data, off, len)))
1465 goto out;
1466
1467 /* Adjust the chunk length field. */
1468 chunk->chunk_hdr->length =
1469 htons(ntohs(chunk->chunk_hdr->length) + len);
1470 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1471
1472out:
1473 return err;
1474}
1475
1476/* Helper function to assign a TSN if needed. This assumes that both
1477 * the data_hdr and association have already been assigned.
1478 */
1479void sctp_chunk_assign_ssn(struct sctp_chunk *chunk)
1480{
1481 struct sctp_datamsg *msg;
1482 struct sctp_chunk *lchunk;
1483 struct sctp_stream *stream;
1484 __u16 ssn;
1485 __u16 sid;
1486
1487 if (chunk->has_ssn)
1488 return;
1489
1490 /* All fragments will be on the same stream */
1491 sid = ntohs(chunk->subh.data_hdr->stream);
1492 stream = &chunk->asoc->ssnmap->out;
1493
1494 /* Now assign the sequence number to the entire message.
1495 * All fragments must have the same stream sequence number.
1496 */
1497 msg = chunk->msg;
1498 list_for_each_entry(lchunk, &msg->chunks, frag_list) {
1499 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
1500 ssn = 0;
1501 } else {
1502 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG)
1503 ssn = sctp_ssn_next(stream, sid);
1504 else
1505 ssn = sctp_ssn_peek(stream, sid);
1506 }
1507
1508 lchunk->subh.data_hdr->ssn = htons(ssn);
1509 lchunk->has_ssn = 1;
1510 }
1511}
1512
1513/* Helper function to assign a TSN if needed. This assumes that both
1514 * the data_hdr and association have already been assigned.
1515 */
1516void sctp_chunk_assign_tsn(struct sctp_chunk *chunk)
1517{
1518 if (!chunk->has_tsn) {
1519 /* This is the last possible instant to
1520 * assign a TSN.
1521 */
1522 chunk->subh.data_hdr->tsn =
1523 htonl(sctp_association_get_next_tsn(chunk->asoc));
1524 chunk->has_tsn = 1;
1525 }
1526}
1527
1528/* Create a CLOSED association to use with an incoming packet. */
1529struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep,
1530 struct sctp_chunk *chunk,
1531 gfp_t gfp)
1532{
1533 struct sctp_association *asoc;
1534 struct sk_buff *skb;
1535 sctp_scope_t scope;
1536 struct sctp_af *af;
1537
1538 /* Create the bare association. */
1539 scope = sctp_scope(sctp_source(chunk));
1540 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp);
1541 if (!asoc)
1542 goto nodata;
1543 asoc->temp = 1;
1544 skb = chunk->skb;
1545 /* Create an entry for the source address of the packet. */
1546 af = sctp_get_af_specific(ipver2af(ip_hdr(skb)->version));
1547 if (unlikely(!af))
1548 goto fail;
1549 af->from_skb(&asoc->c.peer_addr, skb, 1);
1550nodata:
1551 return asoc;
1552
1553fail:
1554 sctp_association_free(asoc);
1555 return NULL;
1556}
1557
1558/* Build a cookie representing asoc.
1559 * This INCLUDES the param header needed to put the cookie in the INIT ACK.
1560 */
1561static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep,
1562 const struct sctp_association *asoc,
1563 const struct sctp_chunk *init_chunk,
1564 int *cookie_len,
1565 const __u8 *raw_addrs, int addrs_len)
1566{
1567 sctp_cookie_param_t *retval;
1568 struct sctp_signed_cookie *cookie;
1569 struct scatterlist sg;
1570 int headersize, bodysize;
1571 unsigned int keylen;
1572 char *key;
1573
1574 /* Header size is static data prior to the actual cookie, including
1575 * any padding.
1576 */
1577 headersize = sizeof(sctp_paramhdr_t) +
1578 (sizeof(struct sctp_signed_cookie) -
1579 sizeof(struct sctp_cookie));
1580 bodysize = sizeof(struct sctp_cookie)
1581 + ntohs(init_chunk->chunk_hdr->length) + addrs_len;
1582
1583 /* Pad out the cookie to a multiple to make the signature
1584 * functions simpler to write.
1585 */
1586 if (bodysize % SCTP_COOKIE_MULTIPLE)
1587 bodysize += SCTP_COOKIE_MULTIPLE
1588 - (bodysize % SCTP_COOKIE_MULTIPLE);
1589 *cookie_len = headersize + bodysize;
1590
1591 /* Clear this memory since we are sending this data structure
1592 * out on the network.
1593 */
1594 retval = kzalloc(*cookie_len, GFP_ATOMIC);
1595 if (!retval)
1596 goto nodata;
1597
1598 cookie = (struct sctp_signed_cookie *) retval->body;
1599
1600 /* Set up the parameter header. */
1601 retval->p.type = SCTP_PARAM_STATE_COOKIE;
1602 retval->p.length = htons(*cookie_len);
1603
1604 /* Copy the cookie part of the association itself. */
1605 cookie->c = asoc->c;
1606 /* Save the raw address list length in the cookie. */
1607 cookie->c.raw_addr_list_len = addrs_len;
1608
1609 /* Remember PR-SCTP capability. */
1610 cookie->c.prsctp_capable = asoc->peer.prsctp_capable;
1611
1612 /* Save adaptation indication in the cookie. */
1613 cookie->c.adaptation_ind = asoc->peer.adaptation_ind;
1614
1615 /* Set an expiration time for the cookie. */
1616 do_gettimeofday(&cookie->c.expiration);
1617 TIMEVAL_ADD(asoc->cookie_life, cookie->c.expiration);
1618
1619 /* Copy the peer's init packet. */
1620 memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr,
1621 ntohs(init_chunk->chunk_hdr->length));
1622
1623 /* Copy the raw local address list of the association. */
1624 memcpy((__u8 *)&cookie->c.peer_init[0] +
1625 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len);
1626
1627 if (sctp_sk(ep->base.sk)->hmac) {
1628 struct hash_desc desc;
1629
1630 /* Sign the message. */
1631 sg_init_one(&sg, &cookie->c, bodysize);
1632 keylen = SCTP_SECRET_SIZE;
1633 key = (char *)ep->secret_key[ep->current_key];
1634 desc.tfm = sctp_sk(ep->base.sk)->hmac;
1635 desc.flags = 0;
1636
1637 if (crypto_hash_setkey(desc.tfm, key, keylen) ||
1638 crypto_hash_digest(&desc, &sg, bodysize, cookie->signature))
1639 goto free_cookie;
1640 }
1641
1642 return retval;
1643
1644free_cookie:
1645 kfree(retval);
1646nodata:
1647 *cookie_len = 0;
1648 return NULL;
1649}
1650
1651/* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */
1652struct sctp_association *sctp_unpack_cookie(
1653 const struct sctp_endpoint *ep,
1654 const struct sctp_association *asoc,
1655 struct sctp_chunk *chunk, gfp_t gfp,
1656 int *error, struct sctp_chunk **errp)
1657{
1658 struct sctp_association *retval = NULL;
1659 struct sctp_signed_cookie *cookie;
1660 struct sctp_cookie *bear_cookie;
1661 int headersize, bodysize, fixed_size;
1662 __u8 *digest = ep->digest;
1663 struct scatterlist sg;
1664 unsigned int keylen, len;
1665 char *key;
1666 sctp_scope_t scope;
1667 struct sk_buff *skb = chunk->skb;
1668 struct timeval tv;
1669 struct hash_desc desc;
1670
1671 /* Header size is static data prior to the actual cookie, including
1672 * any padding.
1673 */
1674 headersize = sizeof(sctp_chunkhdr_t) +
1675 (sizeof(struct sctp_signed_cookie) -
1676 sizeof(struct sctp_cookie));
1677 bodysize = ntohs(chunk->chunk_hdr->length) - headersize;
1678 fixed_size = headersize + sizeof(struct sctp_cookie);
1679
1680 /* Verify that the chunk looks like it even has a cookie.
1681 * There must be enough room for our cookie and our peer's
1682 * INIT chunk.
1683 */
1684 len = ntohs(chunk->chunk_hdr->length);
1685 if (len < fixed_size + sizeof(struct sctp_chunkhdr))
1686 goto malformed;
1687
1688 /* Verify that the cookie has been padded out. */
1689 if (bodysize % SCTP_COOKIE_MULTIPLE)
1690 goto malformed;
1691
1692 /* Process the cookie. */
1693 cookie = chunk->subh.cookie_hdr;
1694 bear_cookie = &cookie->c;
1695
1696 if (!sctp_sk(ep->base.sk)->hmac)
1697 goto no_hmac;
1698
1699 /* Check the signature. */
1700 keylen = SCTP_SECRET_SIZE;
1701 sg_init_one(&sg, bear_cookie, bodysize);
1702 key = (char *)ep->secret_key[ep->current_key];
1703 desc.tfm = sctp_sk(ep->base.sk)->hmac;
1704 desc.flags = 0;
1705
1706 memset(digest, 0x00, SCTP_SIGNATURE_SIZE);
1707 if (crypto_hash_setkey(desc.tfm, key, keylen) ||
1708 crypto_hash_digest(&desc, &sg, bodysize, digest)) {
1709 *error = -SCTP_IERROR_NOMEM;
1710 goto fail;
1711 }
1712
1713 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
1714 /* Try the previous key. */
1715 key = (char *)ep->secret_key[ep->last_key];
1716 memset(digest, 0x00, SCTP_SIGNATURE_SIZE);
1717 if (crypto_hash_setkey(desc.tfm, key, keylen) ||
1718 crypto_hash_digest(&desc, &sg, bodysize, digest)) {
1719 *error = -SCTP_IERROR_NOMEM;
1720 goto fail;
1721 }
1722
1723 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
1724 /* Yikes! Still bad signature! */
1725 *error = -SCTP_IERROR_BAD_SIG;
1726 goto fail;
1727 }
1728 }
1729
1730no_hmac:
1731 /* IG Section 2.35.2:
1732 * 3) Compare the port numbers and the verification tag contained
1733 * within the COOKIE ECHO chunk to the actual port numbers and the
1734 * verification tag within the SCTP common header of the received
1735 * packet. If these values do not match the packet MUST be silently
1736 * discarded,
1737 */
1738 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) {
1739 *error = -SCTP_IERROR_BAD_TAG;
1740 goto fail;
1741 }
1742
1743 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port ||
1744 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) {
1745 *error = -SCTP_IERROR_BAD_PORTS;
1746 goto fail;
1747 }
1748
1749 /* Check to see if the cookie is stale. If there is already
1750 * an association, there is no need to check cookie's expiration
1751 * for init collision case of lost COOKIE ACK.
1752 * If skb has been timestamped, then use the stamp, otherwise
1753 * use current time. This introduces a small possibility that
1754 * that a cookie may be considered expired, but his would only slow
1755 * down the new association establishment instead of every packet.
1756 */
1757 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP))
1758 skb_get_timestamp(skb, &tv);
1759 else
1760 do_gettimeofday(&tv);
1761
1762 if (!asoc && tv_lt(bear_cookie->expiration, tv)) {
1763 /*
1764 * Section 3.3.10.3 Stale Cookie Error (3)
1765 *
1766 * Cause of error
1767 * ---------------
1768 * Stale Cookie Error: Indicates the receipt of a valid State
1769 * Cookie that has expired.
1770 */
1771 len = ntohs(chunk->chunk_hdr->length);
1772 *errp = sctp_make_op_error_space(asoc, chunk, len);
1773 if (*errp) {
1774 suseconds_t usecs = (tv.tv_sec -
1775 bear_cookie->expiration.tv_sec) * 1000000L +
1776 tv.tv_usec - bear_cookie->expiration.tv_usec;
1777 __be32 n = htonl(usecs);
1778
1779 sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE,
1780 sizeof(n));
1781 sctp_addto_chunk(*errp, sizeof(n), &n);
1782 *error = -SCTP_IERROR_STALE_COOKIE;
1783 } else
1784 *error = -SCTP_IERROR_NOMEM;
1785
1786 goto fail;
1787 }
1788
1789 /* Make a new base association. */
1790 scope = sctp_scope(sctp_source(chunk));
1791 retval = sctp_association_new(ep, ep->base.sk, scope, gfp);
1792 if (!retval) {
1793 *error = -SCTP_IERROR_NOMEM;
1794 goto fail;
1795 }
1796
1797 /* Set up our peer's port number. */
1798 retval->peer.port = ntohs(chunk->sctp_hdr->source);
1799
1800 /* Populate the association from the cookie. */
1801 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie));
1802
1803 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie,
1804 GFP_ATOMIC) < 0) {
1805 *error = -SCTP_IERROR_NOMEM;
1806 goto fail;
1807 }
1808
1809 /* Also, add the destination address. */
1810 if (list_empty(&retval->base.bind_addr.address_list)) {
1811 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest,
1812 SCTP_ADDR_SRC, GFP_ATOMIC);
1813 }
1814
1815 retval->next_tsn = retval->c.initial_tsn;
1816 retval->ctsn_ack_point = retval->next_tsn - 1;
1817 retval->addip_serial = retval->c.initial_tsn;
1818 retval->adv_peer_ack_point = retval->ctsn_ack_point;
1819 retval->peer.prsctp_capable = retval->c.prsctp_capable;
1820 retval->peer.adaptation_ind = retval->c.adaptation_ind;
1821
1822 /* The INIT stuff will be done by the side effects. */
1823 return retval;
1824
1825fail:
1826 if (retval)
1827 sctp_association_free(retval);
1828
1829 return NULL;
1830
1831malformed:
1832 /* Yikes! The packet is either corrupt or deliberately
1833 * malformed.
1834 */
1835 *error = -SCTP_IERROR_MALFORMED;
1836 goto fail;
1837}
1838
1839/********************************************************************
1840 * 3rd Level Abstractions
1841 ********************************************************************/
1842
1843struct __sctp_missing {
1844 __be32 num_missing;
1845 __be16 type;
1846} __packed;
1847
1848/*
1849 * Report a missing mandatory parameter.
1850 */
1851static int sctp_process_missing_param(const struct sctp_association *asoc,
1852 sctp_param_t paramtype,
1853 struct sctp_chunk *chunk,
1854 struct sctp_chunk **errp)
1855{
1856 struct __sctp_missing report;
1857 __u16 len;
1858
1859 len = WORD_ROUND(sizeof(report));
1860
1861 /* Make an ERROR chunk, preparing enough room for
1862 * returning multiple unknown parameters.
1863 */
1864 if (!*errp)
1865 *errp = sctp_make_op_error_space(asoc, chunk, len);
1866
1867 if (*errp) {
1868 report.num_missing = htonl(1);
1869 report.type = paramtype;
1870 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM,
1871 sizeof(report));
1872 sctp_addto_chunk(*errp, sizeof(report), &report);
1873 }
1874
1875 /* Stop processing this chunk. */
1876 return 0;
1877}
1878
1879/* Report an Invalid Mandatory Parameter. */
1880static int sctp_process_inv_mandatory(const struct sctp_association *asoc,
1881 struct sctp_chunk *chunk,
1882 struct sctp_chunk **errp)
1883{
1884 /* Invalid Mandatory Parameter Error has no payload. */
1885
1886 if (!*errp)
1887 *errp = sctp_make_op_error_space(asoc, chunk, 0);
1888
1889 if (*errp)
1890 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0);
1891
1892 /* Stop processing this chunk. */
1893 return 0;
1894}
1895
1896static int sctp_process_inv_paramlength(const struct sctp_association *asoc,
1897 struct sctp_paramhdr *param,
1898 const struct sctp_chunk *chunk,
1899 struct sctp_chunk **errp)
1900{
1901 /* This is a fatal error. Any accumulated non-fatal errors are
1902 * not reported.
1903 */
1904 if (*errp)
1905 sctp_chunk_free(*errp);
1906
1907 /* Create an error chunk and fill it in with our payload. */
1908 *errp = sctp_make_violation_paramlen(asoc, chunk, param);
1909
1910 return 0;
1911}
1912
1913
1914/* Do not attempt to handle the HOST_NAME parm. However, do
1915 * send back an indicator to the peer.
1916 */
1917static int sctp_process_hn_param(const struct sctp_association *asoc,
1918 union sctp_params param,
1919 struct sctp_chunk *chunk,
1920 struct sctp_chunk **errp)
1921{
1922 __u16 len = ntohs(param.p->length);
1923
1924 /* Processing of the HOST_NAME parameter will generate an
1925 * ABORT. If we've accumulated any non-fatal errors, they
1926 * would be unrecognized parameters and we should not include
1927 * them in the ABORT.
1928 */
1929 if (*errp)
1930 sctp_chunk_free(*errp);
1931
1932 *errp = sctp_make_op_error_space(asoc, chunk, len);
1933
1934 if (*errp) {
1935 sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, len);
1936 sctp_addto_chunk(*errp, len, param.v);
1937 }
1938
1939 /* Stop processing this chunk. */
1940 return 0;
1941}
1942
1943static int sctp_verify_ext_param(union sctp_params param)
1944{
1945 __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
1946 int have_auth = 0;
1947 int have_asconf = 0;
1948 int i;
1949
1950 for (i = 0; i < num_ext; i++) {
1951 switch (param.ext->chunks[i]) {
1952 case SCTP_CID_AUTH:
1953 have_auth = 1;
1954 break;
1955 case SCTP_CID_ASCONF:
1956 case SCTP_CID_ASCONF_ACK:
1957 have_asconf = 1;
1958 break;
1959 }
1960 }
1961
1962 /* ADD-IP Security: The draft requires us to ABORT or ignore the
1963 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this
1964 * only if ADD-IP is turned on and we are not backward-compatible
1965 * mode.
1966 */
1967 if (sctp_addip_noauth)
1968 return 1;
1969
1970 if (sctp_addip_enable && !have_auth && have_asconf)
1971 return 0;
1972
1973 return 1;
1974}
1975
1976static void sctp_process_ext_param(struct sctp_association *asoc,
1977 union sctp_params param)
1978{
1979 __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
1980 int i;
1981
1982 for (i = 0; i < num_ext; i++) {
1983 switch (param.ext->chunks[i]) {
1984 case SCTP_CID_FWD_TSN:
1985 if (sctp_prsctp_enable &&
1986 !asoc->peer.prsctp_capable)
1987 asoc->peer.prsctp_capable = 1;
1988 break;
1989 case SCTP_CID_AUTH:
1990 /* if the peer reports AUTH, assume that he
1991 * supports AUTH.
1992 */
1993 if (sctp_auth_enable)
1994 asoc->peer.auth_capable = 1;
1995 break;
1996 case SCTP_CID_ASCONF:
1997 case SCTP_CID_ASCONF_ACK:
1998 if (sctp_addip_enable)
1999 asoc->peer.asconf_capable = 1;
2000 break;
2001 default:
2002 break;
2003 }
2004 }
2005}
2006
2007/* RFC 3.2.1 & the Implementers Guide 2.2.
2008 *
2009 * The Parameter Types are encoded such that the
2010 * highest-order two bits specify the action that must be
2011 * taken if the processing endpoint does not recognize the
2012 * Parameter Type.
2013 *
2014 * 00 - Stop processing this parameter; do not process any further
2015 * parameters within this chunk
2016 *
2017 * 01 - Stop processing this parameter, do not process any further
2018 * parameters within this chunk, and report the unrecognized
2019 * parameter in an 'Unrecognized Parameter' ERROR chunk.
2020 *
2021 * 10 - Skip this parameter and continue processing.
2022 *
2023 * 11 - Skip this parameter and continue processing but
2024 * report the unrecognized parameter in an
2025 * 'Unrecognized Parameter' ERROR chunk.
2026 *
2027 * Return value:
2028 * SCTP_IERROR_NO_ERROR - continue with the chunk
2029 * SCTP_IERROR_ERROR - stop and report an error.
2030 * SCTP_IERROR_NOMEME - out of memory.
2031 */
2032static sctp_ierror_t sctp_process_unk_param(const struct sctp_association *asoc,
2033 union sctp_params param,
2034 struct sctp_chunk *chunk,
2035 struct sctp_chunk **errp)
2036{
2037 int retval = SCTP_IERROR_NO_ERROR;
2038
2039 switch (param.p->type & SCTP_PARAM_ACTION_MASK) {
2040 case SCTP_PARAM_ACTION_DISCARD:
2041 retval = SCTP_IERROR_ERROR;
2042 break;
2043 case SCTP_PARAM_ACTION_SKIP:
2044 break;
2045 case SCTP_PARAM_ACTION_DISCARD_ERR:
2046 retval = SCTP_IERROR_ERROR;
2047 /* Fall through */
2048 case SCTP_PARAM_ACTION_SKIP_ERR:
2049 /* Make an ERROR chunk, preparing enough room for
2050 * returning multiple unknown parameters.
2051 */
2052 if (NULL == *errp)
2053 *errp = sctp_make_op_error_fixed(asoc, chunk);
2054
2055 if (*errp) {
2056 if (!sctp_init_cause_fixed(*errp, SCTP_ERROR_UNKNOWN_PARAM,
2057 WORD_ROUND(ntohs(param.p->length))))
2058 sctp_addto_chunk_fixed(*errp,
2059 WORD_ROUND(ntohs(param.p->length)),
2060 param.v);
2061 } else {
2062 /* If there is no memory for generating the ERROR
2063 * report as specified, an ABORT will be triggered
2064 * to the peer and the association won't be
2065 * established.
2066 */
2067 retval = SCTP_IERROR_NOMEM;
2068 }
2069 break;
2070 default:
2071 break;
2072 }
2073
2074 return retval;
2075}
2076
2077/* Verify variable length parameters
2078 * Return values:
2079 * SCTP_IERROR_ABORT - trigger an ABORT
2080 * SCTP_IERROR_NOMEM - out of memory (abort)
2081 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR
2082 * SCTP_IERROR_NO_ERROR - continue with the chunk
2083 */
2084static sctp_ierror_t sctp_verify_param(const struct sctp_association *asoc,
2085 union sctp_params param,
2086 sctp_cid_t cid,
2087 struct sctp_chunk *chunk,
2088 struct sctp_chunk **err_chunk)
2089{
2090 struct sctp_hmac_algo_param *hmacs;
2091 int retval = SCTP_IERROR_NO_ERROR;
2092 __u16 n_elt, id = 0;
2093 int i;
2094
2095 /* FIXME - This routine is not looking at each parameter per the
2096 * chunk type, i.e., unrecognized parameters should be further
2097 * identified based on the chunk id.
2098 */
2099
2100 switch (param.p->type) {
2101 case SCTP_PARAM_IPV4_ADDRESS:
2102 case SCTP_PARAM_IPV6_ADDRESS:
2103 case SCTP_PARAM_COOKIE_PRESERVATIVE:
2104 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
2105 case SCTP_PARAM_STATE_COOKIE:
2106 case SCTP_PARAM_HEARTBEAT_INFO:
2107 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
2108 case SCTP_PARAM_ECN_CAPABLE:
2109 case SCTP_PARAM_ADAPTATION_LAYER_IND:
2110 break;
2111
2112 case SCTP_PARAM_SUPPORTED_EXT:
2113 if (!sctp_verify_ext_param(param))
2114 return SCTP_IERROR_ABORT;
2115 break;
2116
2117 case SCTP_PARAM_SET_PRIMARY:
2118 if (sctp_addip_enable)
2119 break;
2120 goto fallthrough;
2121
2122 case SCTP_PARAM_HOST_NAME_ADDRESS:
2123 /* Tell the peer, we won't support this param. */
2124 sctp_process_hn_param(asoc, param, chunk, err_chunk);
2125 retval = SCTP_IERROR_ABORT;
2126 break;
2127
2128 case SCTP_PARAM_FWD_TSN_SUPPORT:
2129 if (sctp_prsctp_enable)
2130 break;
2131 goto fallthrough;
2132
2133 case SCTP_PARAM_RANDOM:
2134 if (!sctp_auth_enable)
2135 goto fallthrough;
2136
2137 /* SCTP-AUTH: Secion 6.1
2138 * If the random number is not 32 byte long the association
2139 * MUST be aborted. The ABORT chunk SHOULD contain the error
2140 * cause 'Protocol Violation'.
2141 */
2142 if (SCTP_AUTH_RANDOM_LENGTH !=
2143 ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) {
2144 sctp_process_inv_paramlength(asoc, param.p,
2145 chunk, err_chunk);
2146 retval = SCTP_IERROR_ABORT;
2147 }
2148 break;
2149
2150 case SCTP_PARAM_CHUNKS:
2151 if (!sctp_auth_enable)
2152 goto fallthrough;
2153
2154 /* SCTP-AUTH: Section 3.2
2155 * The CHUNKS parameter MUST be included once in the INIT or
2156 * INIT-ACK chunk if the sender wants to receive authenticated
2157 * chunks. Its maximum length is 260 bytes.
2158 */
2159 if (260 < ntohs(param.p->length)) {
2160 sctp_process_inv_paramlength(asoc, param.p,
2161 chunk, err_chunk);
2162 retval = SCTP_IERROR_ABORT;
2163 }
2164 break;
2165
2166 case SCTP_PARAM_HMAC_ALGO:
2167 if (!sctp_auth_enable)
2168 goto fallthrough;
2169
2170 hmacs = (struct sctp_hmac_algo_param *)param.p;
2171 n_elt = (ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) >> 1;
2172
2173 /* SCTP-AUTH: Section 6.1
2174 * The HMAC algorithm based on SHA-1 MUST be supported and
2175 * included in the HMAC-ALGO parameter.
2176 */
2177 for (i = 0; i < n_elt; i++) {
2178 id = ntohs(hmacs->hmac_ids[i]);
2179
2180 if (id == SCTP_AUTH_HMAC_ID_SHA1)
2181 break;
2182 }
2183
2184 if (id != SCTP_AUTH_HMAC_ID_SHA1) {
2185 sctp_process_inv_paramlength(asoc, param.p, chunk,
2186 err_chunk);
2187 retval = SCTP_IERROR_ABORT;
2188 }
2189 break;
2190fallthrough:
2191 default:
2192 SCTP_DEBUG_PRINTK("Unrecognized param: %d for chunk %d.\n",
2193 ntohs(param.p->type), cid);
2194 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk);
2195 break;
2196 }
2197 return retval;
2198}
2199
2200/* Verify the INIT packet before we process it. */
2201int sctp_verify_init(const struct sctp_association *asoc,
2202 sctp_cid_t cid,
2203 sctp_init_chunk_t *peer_init,
2204 struct sctp_chunk *chunk,
2205 struct sctp_chunk **errp)
2206{
2207 union sctp_params param;
2208 int has_cookie = 0;
2209 int result;
2210
2211 /* Verify stream values are non-zero. */
2212 if ((0 == peer_init->init_hdr.num_outbound_streams) ||
2213 (0 == peer_init->init_hdr.num_inbound_streams) ||
2214 (0 == peer_init->init_hdr.init_tag) ||
2215 (SCTP_DEFAULT_MINWINDOW > ntohl(peer_init->init_hdr.a_rwnd))) {
2216
2217 return sctp_process_inv_mandatory(asoc, chunk, errp);
2218 }
2219
2220 /* Check for missing mandatory parameters. */
2221 sctp_walk_params(param, peer_init, init_hdr.params) {
2222
2223 if (SCTP_PARAM_STATE_COOKIE == param.p->type)
2224 has_cookie = 1;
2225
2226 } /* for (loop through all parameters) */
2227
2228 /* There is a possibility that a parameter length was bad and
2229 * in that case we would have stoped walking the parameters.
2230 * The current param.p would point at the bad one.
2231 * Current consensus on the mailing list is to generate a PROTOCOL
2232 * VIOLATION error. We build the ERROR chunk here and let the normal
2233 * error handling code build and send the packet.
2234 */
2235 if (param.v != (void*)chunk->chunk_end)
2236 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp);
2237
2238 /* The only missing mandatory param possible today is
2239 * the state cookie for an INIT-ACK chunk.
2240 */
2241 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie)
2242 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE,
2243 chunk, errp);
2244
2245 /* Verify all the variable length parameters */
2246 sctp_walk_params(param, peer_init, init_hdr.params) {
2247
2248 result = sctp_verify_param(asoc, param, cid, chunk, errp);
2249 switch (result) {
2250 case SCTP_IERROR_ABORT:
2251 case SCTP_IERROR_NOMEM:
2252 return 0;
2253 case SCTP_IERROR_ERROR:
2254 return 1;
2255 case SCTP_IERROR_NO_ERROR:
2256 default:
2257 break;
2258 }
2259
2260 } /* for (loop through all parameters) */
2261
2262 return 1;
2263}
2264
2265/* Unpack the parameters in an INIT packet into an association.
2266 * Returns 0 on failure, else success.
2267 * FIXME: This is an association method.
2268 */
2269int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk,
2270 const union sctp_addr *peer_addr,
2271 sctp_init_chunk_t *peer_init, gfp_t gfp)
2272{
2273 union sctp_params param;
2274 struct sctp_transport *transport;
2275 struct list_head *pos, *temp;
2276 struct sctp_af *af;
2277 union sctp_addr addr;
2278 char *cookie;
2279 int src_match = 0;
2280
2281 /* We must include the address that the INIT packet came from.
2282 * This is the only address that matters for an INIT packet.
2283 * When processing a COOKIE ECHO, we retrieve the from address
2284 * of the INIT from the cookie.
2285 */
2286
2287 /* This implementation defaults to making the first transport
2288 * added as the primary transport. The source address seems to
2289 * be a a better choice than any of the embedded addresses.
2290 */
2291 if(!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE))
2292 goto nomem;
2293
2294 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr))
2295 src_match = 1;
2296
2297 /* Process the initialization parameters. */
2298 sctp_walk_params(param, peer_init, init_hdr.params) {
2299 if (!src_match && (param.p->type == SCTP_PARAM_IPV4_ADDRESS ||
2300 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) {
2301 af = sctp_get_af_specific(param_type2af(param.p->type));
2302 af->from_addr_param(&addr, param.addr,
2303 chunk->sctp_hdr->source, 0);
2304 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr))
2305 src_match = 1;
2306 }
2307
2308 if (!sctp_process_param(asoc, param, peer_addr, gfp))
2309 goto clean_up;
2310 }
2311
2312 /* source address of chunk may not match any valid address */
2313 if (!src_match)
2314 goto clean_up;
2315
2316 /* AUTH: After processing the parameters, make sure that we
2317 * have all the required info to potentially do authentications.
2318 */
2319 if (asoc->peer.auth_capable && (!asoc->peer.peer_random ||
2320 !asoc->peer.peer_hmacs))
2321 asoc->peer.auth_capable = 0;
2322
2323 /* In a non-backward compatible mode, if the peer claims
2324 * support for ADD-IP but not AUTH, the ADD-IP spec states
2325 * that we MUST ABORT the association. Section 6. The section
2326 * also give us an option to silently ignore the packet, which
2327 * is what we'll do here.
2328 */
2329 if (!sctp_addip_noauth &&
2330 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) {
2331 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP |
2332 SCTP_PARAM_DEL_IP |
2333 SCTP_PARAM_SET_PRIMARY);
2334 asoc->peer.asconf_capable = 0;
2335 goto clean_up;
2336 }
2337
2338 /* Walk list of transports, removing transports in the UNKNOWN state. */
2339 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
2340 transport = list_entry(pos, struct sctp_transport, transports);
2341 if (transport->state == SCTP_UNKNOWN) {
2342 sctp_assoc_rm_peer(asoc, transport);
2343 }
2344 }
2345
2346 /* The fixed INIT headers are always in network byte
2347 * order.
2348 */
2349 asoc->peer.i.init_tag =
2350 ntohl(peer_init->init_hdr.init_tag);
2351 asoc->peer.i.a_rwnd =
2352 ntohl(peer_init->init_hdr.a_rwnd);
2353 asoc->peer.i.num_outbound_streams =
2354 ntohs(peer_init->init_hdr.num_outbound_streams);
2355 asoc->peer.i.num_inbound_streams =
2356 ntohs(peer_init->init_hdr.num_inbound_streams);
2357 asoc->peer.i.initial_tsn =
2358 ntohl(peer_init->init_hdr.initial_tsn);
2359
2360 /* Apply the upper bounds for output streams based on peer's
2361 * number of inbound streams.
2362 */
2363 if (asoc->c.sinit_num_ostreams >
2364 ntohs(peer_init->init_hdr.num_inbound_streams)) {
2365 asoc->c.sinit_num_ostreams =
2366 ntohs(peer_init->init_hdr.num_inbound_streams);
2367 }
2368
2369 if (asoc->c.sinit_max_instreams >
2370 ntohs(peer_init->init_hdr.num_outbound_streams)) {
2371 asoc->c.sinit_max_instreams =
2372 ntohs(peer_init->init_hdr.num_outbound_streams);
2373 }
2374
2375 /* Copy Initiation tag from INIT to VT_peer in cookie. */
2376 asoc->c.peer_vtag = asoc->peer.i.init_tag;
2377
2378 /* Peer Rwnd : Current calculated value of the peer's rwnd. */
2379 asoc->peer.rwnd = asoc->peer.i.a_rwnd;
2380
2381 /* Copy cookie in case we need to resend COOKIE-ECHO. */
2382 cookie = asoc->peer.cookie;
2383 if (cookie) {
2384 asoc->peer.cookie = kmemdup(cookie, asoc->peer.cookie_len, gfp);
2385 if (!asoc->peer.cookie)
2386 goto clean_up;
2387 }
2388
2389 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily
2390 * high (for example, implementations MAY use the size of the receiver
2391 * advertised window).
2392 */
2393 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
2394 transports) {
2395 transport->ssthresh = asoc->peer.i.a_rwnd;
2396 }
2397
2398 /* Set up the TSN tracking pieces. */
2399 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
2400 asoc->peer.i.initial_tsn, gfp))
2401 goto clean_up;
2402
2403 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
2404 *
2405 * The stream sequence number in all the streams shall start
2406 * from 0 when the association is established. Also, when the
2407 * stream sequence number reaches the value 65535 the next
2408 * stream sequence number shall be set to 0.
2409 */
2410
2411 /* Allocate storage for the negotiated streams if it is not a temporary
2412 * association.
2413 */
2414 if (!asoc->temp) {
2415 int error;
2416
2417 asoc->ssnmap = sctp_ssnmap_new(asoc->c.sinit_max_instreams,
2418 asoc->c.sinit_num_ostreams, gfp);
2419 if (!asoc->ssnmap)
2420 goto clean_up;
2421
2422 error = sctp_assoc_set_id(asoc, gfp);
2423 if (error)
2424 goto clean_up;
2425 }
2426
2427 /* ADDIP Section 4.1 ASCONF Chunk Procedures
2428 *
2429 * When an endpoint has an ASCONF signaled change to be sent to the
2430 * remote endpoint it should do the following:
2431 * ...
2432 * A2) A serial number should be assigned to the Chunk. The serial
2433 * number should be a monotonically increasing number. All serial
2434 * numbers are defined to be initialized at the start of the
2435 * association to the same value as the Initial TSN.
2436 */
2437 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1;
2438 return 1;
2439
2440clean_up:
2441 /* Release the transport structures. */
2442 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
2443 transport = list_entry(pos, struct sctp_transport, transports);
2444 if (transport->state != SCTP_ACTIVE)
2445 sctp_assoc_rm_peer(asoc, transport);
2446 }
2447
2448nomem:
2449 return 0;
2450}
2451
2452
2453/* Update asoc with the option described in param.
2454 *
2455 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT
2456 *
2457 * asoc is the association to update.
2458 * param is the variable length parameter to use for update.
2459 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO.
2460 * If the current packet is an INIT we want to minimize the amount of
2461 * work we do. In particular, we should not build transport
2462 * structures for the addresses.
2463 */
2464static int sctp_process_param(struct sctp_association *asoc,
2465 union sctp_params param,
2466 const union sctp_addr *peer_addr,
2467 gfp_t gfp)
2468{
2469 union sctp_addr addr;
2470 int i;
2471 __u16 sat;
2472 int retval = 1;
2473 sctp_scope_t scope;
2474 time_t stale;
2475 struct sctp_af *af;
2476 union sctp_addr_param *addr_param;
2477 struct sctp_transport *t;
2478
2479 /* We maintain all INIT parameters in network byte order all the
2480 * time. This allows us to not worry about whether the parameters
2481 * came from a fresh INIT, and INIT ACK, or were stored in a cookie.
2482 */
2483 switch (param.p->type) {
2484 case SCTP_PARAM_IPV6_ADDRESS:
2485 if (PF_INET6 != asoc->base.sk->sk_family)
2486 break;
2487 goto do_addr_param;
2488
2489 case SCTP_PARAM_IPV4_ADDRESS:
2490 /* v4 addresses are not allowed on v6-only socket */
2491 if (ipv6_only_sock(asoc->base.sk))
2492 break;
2493do_addr_param:
2494 af = sctp_get_af_specific(param_type2af(param.p->type));
2495 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0);
2496 scope = sctp_scope(peer_addr);
2497 if (sctp_in_scope(&addr, scope))
2498 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED))
2499 return 0;
2500 break;
2501
2502 case SCTP_PARAM_COOKIE_PRESERVATIVE:
2503 if (!sctp_cookie_preserve_enable)
2504 break;
2505
2506 stale = ntohl(param.life->lifespan_increment);
2507
2508 /* Suggested Cookie Life span increment's unit is msec,
2509 * (1/1000sec).
2510 */
2511 asoc->cookie_life.tv_sec += stale / 1000;
2512 asoc->cookie_life.tv_usec += (stale % 1000) * 1000;
2513 break;
2514
2515 case SCTP_PARAM_HOST_NAME_ADDRESS:
2516 SCTP_DEBUG_PRINTK("unimplemented SCTP_HOST_NAME_ADDRESS\n");
2517 break;
2518
2519 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
2520 /* Turn off the default values first so we'll know which
2521 * ones are really set by the peer.
2522 */
2523 asoc->peer.ipv4_address = 0;
2524 asoc->peer.ipv6_address = 0;
2525
2526 /* Assume that peer supports the address family
2527 * by which it sends a packet.
2528 */
2529 if (peer_addr->sa.sa_family == AF_INET6)
2530 asoc->peer.ipv6_address = 1;
2531 else if (peer_addr->sa.sa_family == AF_INET)
2532 asoc->peer.ipv4_address = 1;
2533
2534 /* Cycle through address types; avoid divide by 0. */
2535 sat = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
2536 if (sat)
2537 sat /= sizeof(__u16);
2538
2539 for (i = 0; i < sat; ++i) {
2540 switch (param.sat->types[i]) {
2541 case SCTP_PARAM_IPV4_ADDRESS:
2542 asoc->peer.ipv4_address = 1;
2543 break;
2544
2545 case SCTP_PARAM_IPV6_ADDRESS:
2546 if (PF_INET6 == asoc->base.sk->sk_family)
2547 asoc->peer.ipv6_address = 1;
2548 break;
2549
2550 case SCTP_PARAM_HOST_NAME_ADDRESS:
2551 asoc->peer.hostname_address = 1;
2552 break;
2553
2554 default: /* Just ignore anything else. */
2555 break;
2556 }
2557 }
2558 break;
2559
2560 case SCTP_PARAM_STATE_COOKIE:
2561 asoc->peer.cookie_len =
2562 ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
2563 asoc->peer.cookie = param.cookie->body;
2564 break;
2565
2566 case SCTP_PARAM_HEARTBEAT_INFO:
2567 /* Would be odd to receive, but it causes no problems. */
2568 break;
2569
2570 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
2571 /* Rejected during verify stage. */
2572 break;
2573
2574 case SCTP_PARAM_ECN_CAPABLE:
2575 asoc->peer.ecn_capable = 1;
2576 break;
2577
2578 case SCTP_PARAM_ADAPTATION_LAYER_IND:
2579 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind);
2580 break;
2581
2582 case SCTP_PARAM_SET_PRIMARY:
2583 if (!sctp_addip_enable)
2584 goto fall_through;
2585
2586 addr_param = param.v + sizeof(sctp_addip_param_t);
2587
2588 af = sctp_get_af_specific(param_type2af(param.p->type));
2589 af->from_addr_param(&addr, addr_param,
2590 htons(asoc->peer.port), 0);
2591
2592 /* if the address is invalid, we can't process it.
2593 * XXX: see spec for what to do.
2594 */
2595 if (!af->addr_valid(&addr, NULL, NULL))
2596 break;
2597
2598 t = sctp_assoc_lookup_paddr(asoc, &addr);
2599 if (!t)
2600 break;
2601
2602 sctp_assoc_set_primary(asoc, t);
2603 break;
2604
2605 case SCTP_PARAM_SUPPORTED_EXT:
2606 sctp_process_ext_param(asoc, param);
2607 break;
2608
2609 case SCTP_PARAM_FWD_TSN_SUPPORT:
2610 if (sctp_prsctp_enable) {
2611 asoc->peer.prsctp_capable = 1;
2612 break;
2613 }
2614 /* Fall Through */
2615 goto fall_through;
2616
2617 case SCTP_PARAM_RANDOM:
2618 if (!sctp_auth_enable)
2619 goto fall_through;
2620
2621 /* Save peer's random parameter */
2622 asoc->peer.peer_random = kmemdup(param.p,
2623 ntohs(param.p->length), gfp);
2624 if (!asoc->peer.peer_random) {
2625 retval = 0;
2626 break;
2627 }
2628 break;
2629
2630 case SCTP_PARAM_HMAC_ALGO:
2631 if (!sctp_auth_enable)
2632 goto fall_through;
2633
2634 /* Save peer's HMAC list */
2635 asoc->peer.peer_hmacs = kmemdup(param.p,
2636 ntohs(param.p->length), gfp);
2637 if (!asoc->peer.peer_hmacs) {
2638 retval = 0;
2639 break;
2640 }
2641
2642 /* Set the default HMAC the peer requested*/
2643 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo);
2644 break;
2645
2646 case SCTP_PARAM_CHUNKS:
2647 if (!sctp_auth_enable)
2648 goto fall_through;
2649
2650 asoc->peer.peer_chunks = kmemdup(param.p,
2651 ntohs(param.p->length), gfp);
2652 if (!asoc->peer.peer_chunks)
2653 retval = 0;
2654 break;
2655fall_through:
2656 default:
2657 /* Any unrecognized parameters should have been caught
2658 * and handled by sctp_verify_param() which should be
2659 * called prior to this routine. Simply log the error
2660 * here.
2661 */
2662 SCTP_DEBUG_PRINTK("Ignoring param: %d for association %p.\n",
2663 ntohs(param.p->type), asoc);
2664 break;
2665 }
2666
2667 return retval;
2668}
2669
2670/* Select a new verification tag. */
2671__u32 sctp_generate_tag(const struct sctp_endpoint *ep)
2672{
2673 /* I believe that this random number generator complies with RFC1750.
2674 * A tag of 0 is reserved for special cases (e.g. INIT).
2675 */
2676 __u32 x;
2677
2678 do {
2679 get_random_bytes(&x, sizeof(__u32));
2680 } while (x == 0);
2681
2682 return x;
2683}
2684
2685/* Select an initial TSN to send during startup. */
2686__u32 sctp_generate_tsn(const struct sctp_endpoint *ep)
2687{
2688 __u32 retval;
2689
2690 get_random_bytes(&retval, sizeof(__u32));
2691 return retval;
2692}
2693
2694/*
2695 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF)
2696 * 0 1 2 3
2697 * 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
2698 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2699 * | Type = 0xC1 | Chunk Flags | Chunk Length |
2700 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2701 * | Serial Number |
2702 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2703 * | Address Parameter |
2704 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2705 * | ASCONF Parameter #1 |
2706 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2707 * \ \
2708 * / .... /
2709 * \ \
2710 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2711 * | ASCONF Parameter #N |
2712 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2713 *
2714 * Address Parameter and other parameter will not be wrapped in this function
2715 */
2716static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc,
2717 union sctp_addr *addr,
2718 int vparam_len)
2719{
2720 sctp_addiphdr_t asconf;
2721 struct sctp_chunk *retval;
2722 int length = sizeof(asconf) + vparam_len;
2723 union sctp_addr_param addrparam;
2724 int addrlen;
2725 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
2726
2727 addrlen = af->to_addr_param(addr, &addrparam);
2728 if (!addrlen)
2729 return NULL;
2730 length += addrlen;
2731
2732 /* Create the chunk. */
2733 retval = sctp_make_chunk(asoc, SCTP_CID_ASCONF, 0, length);
2734 if (!retval)
2735 return NULL;
2736
2737 asconf.serial = htonl(asoc->addip_serial++);
2738
2739 retval->subh.addip_hdr =
2740 sctp_addto_chunk(retval, sizeof(asconf), &asconf);
2741 retval->param_hdr.v =
2742 sctp_addto_chunk(retval, addrlen, &addrparam);
2743
2744 return retval;
2745}
2746
2747/* ADDIP
2748 * 3.2.1 Add IP Address
2749 * 0 1 2 3
2750 * 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
2751 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2752 * | Type = 0xC001 | Length = Variable |
2753 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2754 * | ASCONF-Request Correlation ID |
2755 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2756 * | Address Parameter |
2757 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2758 *
2759 * 3.2.2 Delete IP Address
2760 * 0 1 2 3
2761 * 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
2762 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2763 * | Type = 0xC002 | Length = Variable |
2764 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2765 * | ASCONF-Request Correlation ID |
2766 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2767 * | Address Parameter |
2768 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2769 *
2770 */
2771struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc,
2772 union sctp_addr *laddr,
2773 struct sockaddr *addrs,
2774 int addrcnt,
2775 __be16 flags)
2776{
2777 sctp_addip_param_t param;
2778 struct sctp_chunk *retval;
2779 union sctp_addr_param addr_param;
2780 union sctp_addr *addr;
2781 void *addr_buf;
2782 struct sctp_af *af;
2783 int paramlen = sizeof(param);
2784 int addr_param_len = 0;
2785 int totallen = 0;
2786 int i;
2787 int del_pickup = 0;
2788
2789 /* Get total length of all the address parameters. */
2790 addr_buf = addrs;
2791 for (i = 0; i < addrcnt; i++) {
2792 addr = addr_buf;
2793 af = sctp_get_af_specific(addr->v4.sin_family);
2794 addr_param_len = af->to_addr_param(addr, &addr_param);
2795
2796 totallen += paramlen;
2797 totallen += addr_param_len;
2798
2799 addr_buf += af->sockaddr_len;
2800 if (asoc->asconf_addr_del_pending && !del_pickup) {
2801 /* reuse the parameter length from the same scope one */
2802 totallen += paramlen;
2803 totallen += addr_param_len;
2804 del_pickup = 1;
2805 SCTP_DEBUG_PRINTK("mkasconf_update_ip: picked same-scope del_pending addr, totallen for all addresses is %d\n", totallen);
2806 }
2807 }
2808
2809 /* Create an asconf chunk with the required length. */
2810 retval = sctp_make_asconf(asoc, laddr, totallen);
2811 if (!retval)
2812 return NULL;
2813
2814 /* Add the address parameters to the asconf chunk. */
2815 addr_buf = addrs;
2816 for (i = 0; i < addrcnt; i++) {
2817 addr = addr_buf;
2818 af = sctp_get_af_specific(addr->v4.sin_family);
2819 addr_param_len = af->to_addr_param(addr, &addr_param);
2820 param.param_hdr.type = flags;
2821 param.param_hdr.length = htons(paramlen + addr_param_len);
2822 param.crr_id = i;
2823
2824 sctp_addto_chunk(retval, paramlen, ¶m);
2825 sctp_addto_chunk(retval, addr_param_len, &addr_param);
2826
2827 addr_buf += af->sockaddr_len;
2828 }
2829 if (flags == SCTP_PARAM_ADD_IP && del_pickup) {
2830 addr = asoc->asconf_addr_del_pending;
2831 af = sctp_get_af_specific(addr->v4.sin_family);
2832 addr_param_len = af->to_addr_param(addr, &addr_param);
2833 param.param_hdr.type = SCTP_PARAM_DEL_IP;
2834 param.param_hdr.length = htons(paramlen + addr_param_len);
2835 param.crr_id = i;
2836
2837 sctp_addto_chunk(retval, paramlen, ¶m);
2838 sctp_addto_chunk(retval, addr_param_len, &addr_param);
2839 }
2840 return retval;
2841}
2842
2843/* ADDIP
2844 * 3.2.4 Set Primary IP Address
2845 * 0 1 2 3
2846 * 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
2847 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2848 * | Type =0xC004 | Length = Variable |
2849 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2850 * | ASCONF-Request Correlation ID |
2851 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2852 * | Address Parameter |
2853 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2854 *
2855 * Create an ASCONF chunk with Set Primary IP address parameter.
2856 */
2857struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
2858 union sctp_addr *addr)
2859{
2860 sctp_addip_param_t param;
2861 struct sctp_chunk *retval;
2862 int len = sizeof(param);
2863 union sctp_addr_param addrparam;
2864 int addrlen;
2865 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
2866
2867 addrlen = af->to_addr_param(addr, &addrparam);
2868 if (!addrlen)
2869 return NULL;
2870 len += addrlen;
2871
2872 /* Create the chunk and make asconf header. */
2873 retval = sctp_make_asconf(asoc, addr, len);
2874 if (!retval)
2875 return NULL;
2876
2877 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY;
2878 param.param_hdr.length = htons(len);
2879 param.crr_id = 0;
2880
2881 sctp_addto_chunk(retval, sizeof(param), ¶m);
2882 sctp_addto_chunk(retval, addrlen, &addrparam);
2883
2884 return retval;
2885}
2886
2887/* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK)
2888 * 0 1 2 3
2889 * 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
2890 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2891 * | Type = 0x80 | Chunk Flags | Chunk Length |
2892 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2893 * | Serial Number |
2894 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2895 * | ASCONF Parameter Response#1 |
2896 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2897 * \ \
2898 * / .... /
2899 * \ \
2900 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2901 * | ASCONF Parameter Response#N |
2902 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2903 *
2904 * Create an ASCONF_ACK chunk with enough space for the parameter responses.
2905 */
2906static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc,
2907 __u32 serial, int vparam_len)
2908{
2909 sctp_addiphdr_t asconf;
2910 struct sctp_chunk *retval;
2911 int length = sizeof(asconf) + vparam_len;
2912
2913 /* Create the chunk. */
2914 retval = sctp_make_chunk(asoc, SCTP_CID_ASCONF_ACK, 0, length);
2915 if (!retval)
2916 return NULL;
2917
2918 asconf.serial = htonl(serial);
2919
2920 retval->subh.addip_hdr =
2921 sctp_addto_chunk(retval, sizeof(asconf), &asconf);
2922
2923 return retval;
2924}
2925
2926/* Add response parameters to an ASCONF_ACK chunk. */
2927static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id,
2928 __be16 err_code, sctp_addip_param_t *asconf_param)
2929{
2930 sctp_addip_param_t ack_param;
2931 sctp_errhdr_t err_param;
2932 int asconf_param_len = 0;
2933 int err_param_len = 0;
2934 __be16 response_type;
2935
2936 if (SCTP_ERROR_NO_ERROR == err_code) {
2937 response_type = SCTP_PARAM_SUCCESS_REPORT;
2938 } else {
2939 response_type = SCTP_PARAM_ERR_CAUSE;
2940 err_param_len = sizeof(err_param);
2941 if (asconf_param)
2942 asconf_param_len =
2943 ntohs(asconf_param->param_hdr.length);
2944 }
2945
2946 /* Add Success Indication or Error Cause Indication parameter. */
2947 ack_param.param_hdr.type = response_type;
2948 ack_param.param_hdr.length = htons(sizeof(ack_param) +
2949 err_param_len +
2950 asconf_param_len);
2951 ack_param.crr_id = crr_id;
2952 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param);
2953
2954 if (SCTP_ERROR_NO_ERROR == err_code)
2955 return;
2956
2957 /* Add Error Cause parameter. */
2958 err_param.cause = err_code;
2959 err_param.length = htons(err_param_len + asconf_param_len);
2960 sctp_addto_chunk(chunk, err_param_len, &err_param);
2961
2962 /* Add the failed TLV copied from ASCONF chunk. */
2963 if (asconf_param)
2964 sctp_addto_chunk(chunk, asconf_param_len, asconf_param);
2965}
2966
2967/* Process a asconf parameter. */
2968static __be16 sctp_process_asconf_param(struct sctp_association *asoc,
2969 struct sctp_chunk *asconf,
2970 sctp_addip_param_t *asconf_param)
2971{
2972 struct sctp_transport *peer;
2973 struct sctp_af *af;
2974 union sctp_addr addr;
2975 union sctp_addr_param *addr_param;
2976
2977 addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t);
2978
2979 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP &&
2980 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP &&
2981 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY)
2982 return SCTP_ERROR_UNKNOWN_PARAM;
2983
2984 switch (addr_param->p.type) {
2985 case SCTP_PARAM_IPV6_ADDRESS:
2986 if (!asoc->peer.ipv6_address)
2987 return SCTP_ERROR_DNS_FAILED;
2988 break;
2989 case SCTP_PARAM_IPV4_ADDRESS:
2990 if (!asoc->peer.ipv4_address)
2991 return SCTP_ERROR_DNS_FAILED;
2992 break;
2993 default:
2994 return SCTP_ERROR_DNS_FAILED;
2995 }
2996
2997 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
2998 if (unlikely(!af))
2999 return SCTP_ERROR_DNS_FAILED;
3000
3001 af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0);
3002
3003 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast
3004 * or multicast address.
3005 * (note: wildcard is permitted and requires special handling so
3006 * make sure we check for that)
3007 */
3008 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb))
3009 return SCTP_ERROR_DNS_FAILED;
3010
3011 switch (asconf_param->param_hdr.type) {
3012 case SCTP_PARAM_ADD_IP:
3013 /* Section 4.2.1:
3014 * If the address 0.0.0.0 or ::0 is provided, the source
3015 * address of the packet MUST be added.
3016 */
3017 if (af->is_any(&addr))
3018 memcpy(&addr, &asconf->source, sizeof(addr));
3019
3020 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address
3021 * request and does not have the local resources to add this
3022 * new address to the association, it MUST return an Error
3023 * Cause TLV set to the new error code 'Operation Refused
3024 * Due to Resource Shortage'.
3025 */
3026
3027 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED);
3028 if (!peer)
3029 return SCTP_ERROR_RSRC_LOW;
3030
3031 /* Start the heartbeat timer. */
3032 if (!mod_timer(&peer->hb_timer, sctp_transport_timeout(peer)))
3033 sctp_transport_hold(peer);
3034 asoc->new_transport = peer;
3035 break;
3036 case SCTP_PARAM_DEL_IP:
3037 /* ADDIP 4.3 D7) If a request is received to delete the
3038 * last remaining IP address of a peer endpoint, the receiver
3039 * MUST send an Error Cause TLV with the error cause set to the
3040 * new error code 'Request to Delete Last Remaining IP Address'.
3041 */
3042 if (asoc->peer.transport_count == 1)
3043 return SCTP_ERROR_DEL_LAST_IP;
3044
3045 /* ADDIP 4.3 D8) If a request is received to delete an IP
3046 * address which is also the source address of the IP packet
3047 * which contained the ASCONF chunk, the receiver MUST reject
3048 * this request. To reject the request the receiver MUST send
3049 * an Error Cause TLV set to the new error code 'Request to
3050 * Delete Source IP Address'
3051 */
3052 if (sctp_cmp_addr_exact(&asconf->source, &addr))
3053 return SCTP_ERROR_DEL_SRC_IP;
3054
3055 /* Section 4.2.2
3056 * If the address 0.0.0.0 or ::0 is provided, all
3057 * addresses of the peer except the source address of the
3058 * packet MUST be deleted.
3059 */
3060 if (af->is_any(&addr)) {
3061 sctp_assoc_set_primary(asoc, asconf->transport);
3062 sctp_assoc_del_nonprimary_peers(asoc,
3063 asconf->transport);
3064 } else
3065 sctp_assoc_del_peer(asoc, &addr);
3066 break;
3067 case SCTP_PARAM_SET_PRIMARY:
3068 /* ADDIP Section 4.2.4
3069 * If the address 0.0.0.0 or ::0 is provided, the receiver
3070 * MAY mark the source address of the packet as its
3071 * primary.
3072 */
3073 if (af->is_any(&addr))
3074 memcpy(&addr.v4, sctp_source(asconf), sizeof(addr));
3075
3076 peer = sctp_assoc_lookup_paddr(asoc, &addr);
3077 if (!peer)
3078 return SCTP_ERROR_DNS_FAILED;
3079
3080 sctp_assoc_set_primary(asoc, peer);
3081 break;
3082 }
3083
3084 return SCTP_ERROR_NO_ERROR;
3085}
3086
3087/* Verify the ASCONF packet before we process it. */
3088int sctp_verify_asconf(const struct sctp_association *asoc,
3089 struct sctp_paramhdr *param_hdr, void *chunk_end,
3090 struct sctp_paramhdr **errp) {
3091 sctp_addip_param_t *asconf_param;
3092 union sctp_params param;
3093 int length, plen;
3094
3095 param.v = (sctp_paramhdr_t *) param_hdr;
3096 while (param.v <= chunk_end - sizeof(sctp_paramhdr_t)) {
3097 length = ntohs(param.p->length);
3098 *errp = param.p;
3099
3100 if (param.v > chunk_end - length ||
3101 length < sizeof(sctp_paramhdr_t))
3102 return 0;
3103
3104 switch (param.p->type) {
3105 case SCTP_PARAM_ADD_IP:
3106 case SCTP_PARAM_DEL_IP:
3107 case SCTP_PARAM_SET_PRIMARY:
3108 asconf_param = (sctp_addip_param_t *)param.v;
3109 plen = ntohs(asconf_param->param_hdr.length);
3110 if (plen < sizeof(sctp_addip_param_t) +
3111 sizeof(sctp_paramhdr_t))
3112 return 0;
3113 break;
3114 case SCTP_PARAM_SUCCESS_REPORT:
3115 case SCTP_PARAM_ADAPTATION_LAYER_IND:
3116 if (length != sizeof(sctp_addip_param_t))
3117 return 0;
3118
3119 break;
3120 default:
3121 break;
3122 }
3123
3124 param.v += WORD_ROUND(length);
3125 }
3126
3127 if (param.v != chunk_end)
3128 return 0;
3129
3130 return 1;
3131}
3132
3133/* Process an incoming ASCONF chunk with the next expected serial no. and
3134 * return an ASCONF_ACK chunk to be sent in response.
3135 */
3136struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
3137 struct sctp_chunk *asconf)
3138{
3139 sctp_addiphdr_t *hdr;
3140 union sctp_addr_param *addr_param;
3141 sctp_addip_param_t *asconf_param;
3142 struct sctp_chunk *asconf_ack;
3143
3144 __be16 err_code;
3145 int length = 0;
3146 int chunk_len;
3147 __u32 serial;
3148 int all_param_pass = 1;
3149
3150 chunk_len = ntohs(asconf->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
3151 hdr = (sctp_addiphdr_t *)asconf->skb->data;
3152 serial = ntohl(hdr->serial);
3153
3154 /* Skip the addiphdr and store a pointer to address parameter. */
3155 length = sizeof(sctp_addiphdr_t);
3156 addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
3157 chunk_len -= length;
3158
3159 /* Skip the address parameter and store a pointer to the first
3160 * asconf parameter.
3161 */
3162 length = ntohs(addr_param->p.length);
3163 asconf_param = (void *)addr_param + length;
3164 chunk_len -= length;
3165
3166 /* create an ASCONF_ACK chunk.
3167 * Based on the definitions of parameters, we know that the size of
3168 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF
3169 * parameters.
3170 */
3171 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4);
3172 if (!asconf_ack)
3173 goto done;
3174
3175 /* Process the TLVs contained within the ASCONF chunk. */
3176 while (chunk_len > 0) {
3177 err_code = sctp_process_asconf_param(asoc, asconf,
3178 asconf_param);
3179 /* ADDIP 4.1 A7)
3180 * If an error response is received for a TLV parameter,
3181 * all TLVs with no response before the failed TLV are
3182 * considered successful if not reported. All TLVs after
3183 * the failed response are considered unsuccessful unless
3184 * a specific success indication is present for the parameter.
3185 */
3186 if (SCTP_ERROR_NO_ERROR != err_code)
3187 all_param_pass = 0;
3188
3189 if (!all_param_pass)
3190 sctp_add_asconf_response(asconf_ack,
3191 asconf_param->crr_id, err_code,
3192 asconf_param);
3193
3194 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add
3195 * an IP address sends an 'Out of Resource' in its response, it
3196 * MUST also fail any subsequent add or delete requests bundled
3197 * in the ASCONF.
3198 */
3199 if (SCTP_ERROR_RSRC_LOW == err_code)
3200 goto done;
3201
3202 /* Move to the next ASCONF param. */
3203 length = ntohs(asconf_param->param_hdr.length);
3204 asconf_param = (void *)asconf_param + length;
3205 chunk_len -= length;
3206 }
3207
3208done:
3209 asoc->peer.addip_serial++;
3210
3211 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc
3212 * after freeing the reference to old asconf ack if any.
3213 */
3214 if (asconf_ack) {
3215 sctp_chunk_hold(asconf_ack);
3216 list_add_tail(&asconf_ack->transmitted_list,
3217 &asoc->asconf_ack_list);
3218 }
3219
3220 return asconf_ack;
3221}
3222
3223/* Process a asconf parameter that is successfully acked. */
3224static void sctp_asconf_param_success(struct sctp_association *asoc,
3225 sctp_addip_param_t *asconf_param)
3226{
3227 struct sctp_af *af;
3228 union sctp_addr addr;
3229 struct sctp_bind_addr *bp = &asoc->base.bind_addr;
3230 union sctp_addr_param *addr_param;
3231 struct sctp_transport *transport;
3232 struct sctp_sockaddr_entry *saddr;
3233
3234 addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t);
3235
3236 /* We have checked the packet before, so we do not check again. */
3237 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
3238 af->from_addr_param(&addr, addr_param, htons(bp->port), 0);
3239
3240 switch (asconf_param->param_hdr.type) {
3241 case SCTP_PARAM_ADD_IP:
3242 /* This is always done in BH context with a socket lock
3243 * held, so the list can not change.
3244 */
3245 local_bh_disable();
3246 list_for_each_entry(saddr, &bp->address_list, list) {
3247 if (sctp_cmp_addr_exact(&saddr->a, &addr))
3248 saddr->state = SCTP_ADDR_SRC;
3249 }
3250 local_bh_enable();
3251 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
3252 transports) {
3253 dst_release(transport->dst);
3254 transport->dst = NULL;
3255 }
3256 break;
3257 case SCTP_PARAM_DEL_IP:
3258 local_bh_disable();
3259 sctp_del_bind_addr(bp, &addr);
3260 if (asoc->asconf_addr_del_pending != NULL &&
3261 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) {
3262 kfree(asoc->asconf_addr_del_pending);
3263 asoc->asconf_addr_del_pending = NULL;
3264 }
3265 local_bh_enable();
3266 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
3267 transports) {
3268 dst_release(transport->dst);
3269 transport->dst = NULL;
3270 }
3271 break;
3272 default:
3273 break;
3274 }
3275}
3276
3277/* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk
3278 * for the given asconf parameter. If there is no response for this parameter,
3279 * return the error code based on the third argument 'no_err'.
3280 * ADDIP 4.1
3281 * A7) If an error response is received for a TLV parameter, all TLVs with no
3282 * response before the failed TLV are considered successful if not reported.
3283 * All TLVs after the failed response are considered unsuccessful unless a
3284 * specific success indication is present for the parameter.
3285 */
3286static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack,
3287 sctp_addip_param_t *asconf_param,
3288 int no_err)
3289{
3290 sctp_addip_param_t *asconf_ack_param;
3291 sctp_errhdr_t *err_param;
3292 int length;
3293 int asconf_ack_len;
3294 __be16 err_code;
3295
3296 if (no_err)
3297 err_code = SCTP_ERROR_NO_ERROR;
3298 else
3299 err_code = SCTP_ERROR_REQ_REFUSED;
3300
3301 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) -
3302 sizeof(sctp_chunkhdr_t);
3303
3304 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to
3305 * the first asconf_ack parameter.
3306 */
3307 length = sizeof(sctp_addiphdr_t);
3308 asconf_ack_param = (sctp_addip_param_t *)(asconf_ack->skb->data +
3309 length);
3310 asconf_ack_len -= length;
3311
3312 while (asconf_ack_len > 0) {
3313 if (asconf_ack_param->crr_id == asconf_param->crr_id) {
3314 switch(asconf_ack_param->param_hdr.type) {
3315 case SCTP_PARAM_SUCCESS_REPORT:
3316 return SCTP_ERROR_NO_ERROR;
3317 case SCTP_PARAM_ERR_CAUSE:
3318 length = sizeof(sctp_addip_param_t);
3319 err_param = (void *)asconf_ack_param + length;
3320 asconf_ack_len -= length;
3321 if (asconf_ack_len > 0)
3322 return err_param->cause;
3323 else
3324 return SCTP_ERROR_INV_PARAM;
3325 break;
3326 default:
3327 return SCTP_ERROR_INV_PARAM;
3328 }
3329 }
3330
3331 length = ntohs(asconf_ack_param->param_hdr.length);
3332 asconf_ack_param = (void *)asconf_ack_param + length;
3333 asconf_ack_len -= length;
3334 }
3335
3336 return err_code;
3337}
3338
3339/* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */
3340int sctp_process_asconf_ack(struct sctp_association *asoc,
3341 struct sctp_chunk *asconf_ack)
3342{
3343 struct sctp_chunk *asconf = asoc->addip_last_asconf;
3344 union sctp_addr_param *addr_param;
3345 sctp_addip_param_t *asconf_param;
3346 int length = 0;
3347 int asconf_len = asconf->skb->len;
3348 int all_param_pass = 0;
3349 int no_err = 1;
3350 int retval = 0;
3351 __be16 err_code = SCTP_ERROR_NO_ERROR;
3352
3353 /* Skip the chunkhdr and addiphdr from the last asconf sent and store
3354 * a pointer to address parameter.
3355 */
3356 length = sizeof(sctp_addip_chunk_t);
3357 addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
3358 asconf_len -= length;
3359
3360 /* Skip the address parameter in the last asconf sent and store a
3361 * pointer to the first asconf parameter.
3362 */
3363 length = ntohs(addr_param->p.length);
3364 asconf_param = (void *)addr_param + length;
3365 asconf_len -= length;
3366
3367 /* ADDIP 4.1
3368 * A8) If there is no response(s) to specific TLV parameter(s), and no
3369 * failures are indicated, then all request(s) are considered
3370 * successful.
3371 */
3372 if (asconf_ack->skb->len == sizeof(sctp_addiphdr_t))
3373 all_param_pass = 1;
3374
3375 /* Process the TLVs contained in the last sent ASCONF chunk. */
3376 while (asconf_len > 0) {
3377 if (all_param_pass)
3378 err_code = SCTP_ERROR_NO_ERROR;
3379 else {
3380 err_code = sctp_get_asconf_response(asconf_ack,
3381 asconf_param,
3382 no_err);
3383 if (no_err && (SCTP_ERROR_NO_ERROR != err_code))
3384 no_err = 0;
3385 }
3386
3387 switch (err_code) {
3388 case SCTP_ERROR_NO_ERROR:
3389 sctp_asconf_param_success(asoc, asconf_param);
3390 break;
3391
3392 case SCTP_ERROR_RSRC_LOW:
3393 retval = 1;
3394 break;
3395
3396 case SCTP_ERROR_UNKNOWN_PARAM:
3397 /* Disable sending this type of asconf parameter in
3398 * future.
3399 */
3400 asoc->peer.addip_disabled_mask |=
3401 asconf_param->param_hdr.type;
3402 break;
3403
3404 case SCTP_ERROR_REQ_REFUSED:
3405 case SCTP_ERROR_DEL_LAST_IP:
3406 case SCTP_ERROR_DEL_SRC_IP:
3407 default:
3408 break;
3409 }
3410
3411 /* Skip the processed asconf parameter and move to the next
3412 * one.
3413 */
3414 length = ntohs(asconf_param->param_hdr.length);
3415 asconf_param = (void *)asconf_param + length;
3416 asconf_len -= length;
3417 }
3418
3419 if (no_err && asoc->src_out_of_asoc_ok) {
3420 asoc->src_out_of_asoc_ok = 0;
3421 sctp_transport_immediate_rtx(asoc->peer.primary_path);
3422 }
3423
3424 /* Free the cached last sent asconf chunk. */
3425 list_del_init(&asconf->transmitted_list);
3426 sctp_chunk_free(asconf);
3427 asoc->addip_last_asconf = NULL;
3428
3429 return retval;
3430}
3431
3432/* Make a FWD TSN chunk. */
3433struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
3434 __u32 new_cum_tsn, size_t nstreams,
3435 struct sctp_fwdtsn_skip *skiplist)
3436{
3437 struct sctp_chunk *retval = NULL;
3438 struct sctp_fwdtsn_hdr ftsn_hdr;
3439 struct sctp_fwdtsn_skip skip;
3440 size_t hint;
3441 int i;
3442
3443 hint = (nstreams + 1) * sizeof(__u32);
3444
3445 retval = sctp_make_chunk(asoc, SCTP_CID_FWD_TSN, 0, hint);
3446
3447 if (!retval)
3448 return NULL;
3449
3450 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn);
3451 retval->subh.fwdtsn_hdr =
3452 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr);
3453
3454 for (i = 0; i < nstreams; i++) {
3455 skip.stream = skiplist[i].stream;
3456 skip.ssn = skiplist[i].ssn;
3457 sctp_addto_chunk(retval, sizeof(skip), &skip);
3458 }
3459
3460 return retval;
3461}