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