?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab...
[linux-2.6.git] / net / sctp / sm_make_chunk.c
blobcf579e71cff0652cd2fea2d7aae8c8343ecc66f7
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 aptr->stats.idupchunks += num_dup_tsns;
809 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns,
810 sctp_tsnmap_get_dups(map));
811 }
812 /* Once we have a sack generated, check to see what our sack
813 * generation is, if its 0, reset the transports to 0, and reset
814 * the association generation to 1
815 *
816 * The idea is that zero is never used as a valid generation for the
817 * association so no transport will match after a wrap event like this,
818 * Until the next sack
819 */
820 if (++aptr->peer.sack_generation == 0) {
821 list_for_each_entry(trans, &asoc->peer.transport_addr_list,
822 transports)
823 trans->sack_generation = 0;
824 aptr->peer.sack_generation = 1;
825 }
826 nodata:
827 return retval;
828 }
829
830 /* Make a SHUTDOWN chunk. */
831 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc,
832 const struct sctp_chunk *chunk)
833 {
834 struct sctp_chunk *retval;
835 sctp_shutdownhdr_t shut;
836 __u32 ctsn;
837
838 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
839 shut.cum_tsn_ack = htonl(ctsn);
840
841 retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN, 0,
842 sizeof(sctp_shutdownhdr_t));
843 if (!retval)
844 goto nodata;
845
846 retval->subh.shutdown_hdr =
847 sctp_addto_chunk(retval, sizeof(shut), &shut);
848
849 if (chunk)
850 retval->transport = chunk->transport;
851 nodata:
852 return retval;
853 }
854
855 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc,
856 const struct sctp_chunk *chunk)
857 {
858 struct sctp_chunk *retval;
859
860 retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0);
861
862 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
863 *
864 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
865 * HEARTBEAT ACK, * etc.) to the same destination transport
866 * address from which it * received the DATA or control chunk
867 * to which it is replying.
868 *
869 * [ACK back to where the SHUTDOWN came from.]
870 */
871 if (retval && chunk)
872 retval->transport = chunk->transport;
873
874 return retval;
875 }
876
877 struct sctp_chunk *sctp_make_shutdown_complete(
878 const struct sctp_association *asoc,
879 const struct sctp_chunk *chunk)
880 {
881 struct sctp_chunk *retval;
882 __u8 flags = 0;
883
884 /* Set the T-bit if we have no association (vtag will be
885 * reflected)
886 */
887 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T;
888
889 retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 0);
890
891 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
892 *
893 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
894 * HEARTBEAT ACK, * etc.) to the same destination transport
895 * address from which it * received the DATA or control chunk
896 * to which it is replying.
897 *
898 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK
899 * came from.]
900 */
901 if (retval && chunk)
902 retval->transport = chunk->transport;
903
904 return retval;
905 }
906
907 /* Create an ABORT. Note that we set the T bit if we have no
908 * association, except when responding to an INIT (sctpimpguide 2.41).
909 */
910 struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc,
911 const struct sctp_chunk *chunk,
912 const size_t hint)
913 {
914 struct sctp_chunk *retval;
915 __u8 flags = 0;
916
917 /* Set the T-bit if we have no association and 'chunk' is not
918 * an INIT (vtag will be reflected).
919 */
920 if (!asoc) {
921 if (chunk && chunk->chunk_hdr &&
922 chunk->chunk_hdr->type == SCTP_CID_INIT)
923 flags = 0;
924 else
925 flags = SCTP_CHUNK_FLAG_T;
926 }
927
928 retval = sctp_make_chunk(asoc, SCTP_CID_ABORT, flags, hint);
929
930 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
931 *
932 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
933 * HEARTBEAT ACK, * etc.) to the same destination transport
934 * address from which it * received the DATA or control chunk
935 * to which it is replying.
936 *
937 * [ABORT back to where the offender came from.]
938 */
939 if (retval && chunk)
940 retval->transport = chunk->transport;
941
942 return retval;
943 }
944
945 /* Helper to create ABORT with a NO_USER_DATA error. */
946 struct sctp_chunk *sctp_make_abort_no_data(
947 const struct sctp_association *asoc,
948 const struct sctp_chunk *chunk, __u32 tsn)
949 {
950 struct sctp_chunk *retval;
951 __be32 payload;
952
953 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t)
954 + sizeof(tsn));
955
956 if (!retval)
957 goto no_mem;
958
959 /* Put the tsn back into network byte order. */
960 payload = htonl(tsn);
961 sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload));
962 sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload);
963
964 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
965 *
966 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
967 * HEARTBEAT ACK, * etc.) to the same destination transport
968 * address from which it * received the DATA or control chunk
969 * to which it is replying.
970 *
971 * [ABORT back to where the offender came from.]
972 */
973 if (chunk)
974 retval->transport = chunk->transport;
975
976 no_mem:
977 return retval;
978 }
979
980 /* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */
981 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc,
982 const struct msghdr *msg,
983 size_t paylen)
984 {
985 struct sctp_chunk *retval;
986 void *payload = NULL;
987 int err;
988
989 retval = sctp_make_abort(asoc, NULL, sizeof(sctp_errhdr_t) + paylen);
990 if (!retval)
991 goto err_chunk;
992
993 if (paylen) {
994 /* Put the msg_iov together into payload. */
995 payload = kmalloc(paylen, GFP_KERNEL);
996 if (!payload)
997 goto err_payload;
998
999 err = memcpy_fromiovec(payload, msg->msg_iov, paylen);
1000 if (err < 0)
1001 goto err_copy;
1002 }
1003
1004 sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen);
1005 sctp_addto_chunk(retval, paylen, payload);
1006
1007 if (paylen)
1008 kfree(payload);
1009
1010 return retval;
1011
1012 err_copy:
1013 kfree(payload);
1014 err_payload:
1015 sctp_chunk_free(retval);
1016 retval = NULL;
1017 err_chunk:
1018 return retval;
1019 }
1020
1021 /* Append bytes to the end of a parameter. Will panic if chunk is not big
1022 * enough.
1023 */
1024 static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
1025 const void *data)
1026 {
1027 void *target;
1028 int chunklen = ntohs(chunk->chunk_hdr->length);
1029
1030 target = skb_put(chunk->skb, len);
1031
1032 if (data)
1033 memcpy(target, data, len);
1034 else
1035 memset(target, 0, len);
1036
1037 /* Adjust the chunk length field. */
1038 chunk->chunk_hdr->length = htons(chunklen + len);
1039 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1040
1041 return target;
1042 }
1043
1044 /* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */
1045 struct sctp_chunk *sctp_make_abort_violation(
1046 const struct sctp_association *asoc,
1047 const struct sctp_chunk *chunk,
1048 const __u8 *payload,
1049 const size_t paylen)
1050 {
1051 struct sctp_chunk *retval;
1052 struct sctp_paramhdr phdr;
1053
1054 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) + paylen
1055 + sizeof(sctp_paramhdr_t));
1056 if (!retval)
1057 goto end;
1058
1059 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen
1060 + sizeof(sctp_paramhdr_t));
1061
1062 phdr.type = htons(chunk->chunk_hdr->type);
1063 phdr.length = chunk->chunk_hdr->length;
1064 sctp_addto_chunk(retval, paylen, payload);
1065 sctp_addto_param(retval, sizeof(sctp_paramhdr_t), &phdr);
1066
1067 end:
1068 return retval;
1069 }
1070
1071 struct sctp_chunk *sctp_make_violation_paramlen(
1072 const struct sctp_association *asoc,
1073 const struct sctp_chunk *chunk,
1074 struct sctp_paramhdr *param)
1075 {
1076 struct sctp_chunk *retval;
1077 static const char error[] = "The following parameter had invalid length:";
1078 size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t) +
1079 sizeof(sctp_paramhdr_t);
1080
1081 retval = sctp_make_abort(asoc, chunk, payload_len);
1082 if (!retval)
1083 goto nodata;
1084
1085 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION,
1086 sizeof(error) + sizeof(sctp_paramhdr_t));
1087 sctp_addto_chunk(retval, sizeof(error), error);
1088 sctp_addto_param(retval, sizeof(sctp_paramhdr_t), param);
1089
1090 nodata:
1091 return retval;
1092 }
1093
1094 struct sctp_chunk *sctp_make_violation_max_retrans(
1095 const struct sctp_association *asoc,
1096 const struct sctp_chunk *chunk)
1097 {
1098 struct sctp_chunk *retval;
1099 static const char error[] = "Association exceeded its max_retans count";
1100 size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t);
1101
1102 retval = sctp_make_abort(asoc, chunk, payload_len);
1103 if (!retval)
1104 goto nodata;
1105
1106 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error));
1107 sctp_addto_chunk(retval, sizeof(error), error);
1108
1109 nodata:
1110 return retval;
1111 }
1112
1113 /* Make a HEARTBEAT chunk. */
1114 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc,
1115 const struct sctp_transport *transport)
1116 {
1117 struct sctp_chunk *retval;
1118 sctp_sender_hb_info_t hbinfo;
1119
1120 retval = sctp_make_chunk(asoc, SCTP_CID_HEARTBEAT, 0, sizeof(hbinfo));
1121
1122 if (!retval)
1123 goto nodata;
1124
1125 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO;
1126 hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t));
1127 hbinfo.daddr = transport->ipaddr;
1128 hbinfo.sent_at = jiffies;
1129 hbinfo.hb_nonce = transport->hb_nonce;
1130
1131 /* Cast away the 'const', as this is just telling the chunk
1132 * what transport it belongs to.
1133 */
1134 retval->transport = (struct sctp_transport *) transport;
1135 retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo),
1136 &hbinfo);
1137
1138 nodata:
1139 return retval;
1140 }
1141
1142 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc,
1143 const struct sctp_chunk *chunk,
1144 const void *payload, const size_t paylen)
1145 {
1146 struct sctp_chunk *retval;
1147
1148 retval = sctp_make_chunk(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen);
1149 if (!retval)
1150 goto nodata;
1151
1152 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload);
1153
1154 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
1155 *
1156 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1157 * HEARTBEAT ACK, * etc.) to the same destination transport
1158 * address from which it * received the DATA or control chunk
1159 * to which it is replying.
1160 *
1161 * [HBACK back to where the HEARTBEAT came from.]
1162 */
1163 if (chunk)
1164 retval->transport = chunk->transport;
1165
1166 nodata:
1167 return retval;
1168 }
1169
1170 /* Create an Operation Error chunk with the specified space reserved.
1171 * This routine can be used for containing multiple causes in the chunk.
1172 */
1173 static struct sctp_chunk *sctp_make_op_error_space(
1174 const struct sctp_association *asoc,
1175 const struct sctp_chunk *chunk,
1176 size_t size)
1177 {
1178 struct sctp_chunk *retval;
1179
1180 retval = sctp_make_chunk(asoc, SCTP_CID_ERROR, 0,
1181 sizeof(sctp_errhdr_t) + size);
1182 if (!retval)
1183 goto nodata;
1184
1185 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
1186 *
1187 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1188 * HEARTBEAT ACK, etc.) to the same destination transport
1189 * address from which it received the DATA or control chunk
1190 * to which it is replying.
1191 *
1192 */
1193 if (chunk)
1194 retval->transport = chunk->transport;
1195
1196 nodata:
1197 return retval;
1198 }
1199
1200 /* Create an Operation Error chunk of a fixed size,
1201 * specifically, max(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT)
1202 * This is a helper function to allocate an error chunk for
1203 * for those invalid parameter codes in which we may not want
1204 * to report all the errors, if the incoming chunk is large
1205 */
1206 static inline struct sctp_chunk *sctp_make_op_error_fixed(
1207 const struct sctp_association *asoc,
1208 const struct sctp_chunk *chunk)
1209 {
1210 size_t size = asoc ? asoc->pathmtu : 0;
1211
1212 if (!size)
1213 size = SCTP_DEFAULT_MAXSEGMENT;
1214
1215 return sctp_make_op_error_space(asoc, chunk, size);
1216 }
1217
1218 /* Create an Operation Error chunk. */
1219 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc,
1220 const struct sctp_chunk *chunk,
1221 __be16 cause_code, const void *payload,
1222 size_t paylen, size_t reserve_tail)
1223 {
1224 struct sctp_chunk *retval;
1225
1226 retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail);
1227 if (!retval)
1228 goto nodata;
1229
1230 sctp_init_cause(retval, cause_code, paylen + reserve_tail);
1231 sctp_addto_chunk(retval, paylen, payload);
1232 if (reserve_tail)
1233 sctp_addto_param(retval, reserve_tail, NULL);
1234
1235 nodata:
1236 return retval;
1237 }
1238
1239 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc)
1240 {
1241 struct sctp_chunk *retval;
1242 struct sctp_hmac *hmac_desc;
1243 struct sctp_authhdr auth_hdr;
1244 __u8 *hmac;
1245
1246 /* Get the first hmac that the peer told us to use */
1247 hmac_desc = sctp_auth_asoc_get_hmac(asoc);
1248 if (unlikely(!hmac_desc))
1249 return NULL;
1250
1251 retval = sctp_make_chunk(asoc, SCTP_CID_AUTH, 0,
1252 hmac_desc->hmac_len + sizeof(sctp_authhdr_t));
1253 if (!retval)
1254 return NULL;
1255
1256 auth_hdr.hmac_id = htons(hmac_desc->hmac_id);
1257 auth_hdr.shkey_id = htons(asoc->active_key_id);
1258
1259 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(sctp_authhdr_t),
1260 &auth_hdr);
1261
1262 hmac = skb_put(retval->skb, hmac_desc->hmac_len);
1263 memset(hmac, 0, hmac_desc->hmac_len);
1264
1265 /* Adjust the chunk header to include the empty MAC */
1266 retval->chunk_hdr->length =
1267 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len);
1268 retval->chunk_end = skb_tail_pointer(retval->skb);
1269
1270 return retval;
1271 }
1272
1273
1274 /********************************************************************
1275 * 2nd Level Abstractions
1276 ********************************************************************/
1277
1278 /* Turn an skb into a chunk.
1279 * FIXME: Eventually move the structure directly inside the skb->cb[].
1280 */
1281 struct sctp_chunk *sctp_chunkify(struct sk_buff *skb,
1282 const struct sctp_association *asoc,
1283 struct sock *sk)
1284 {
1285 struct sctp_chunk *retval;
1286
1287 retval = kmem_cache_zalloc(sctp_chunk_cachep, GFP_ATOMIC);
1288
1289 if (!retval)
1290 goto nodata;
1291
1292 if (!sk) {
1293 SCTP_DEBUG_PRINTK("chunkifying skb %p w/o an sk\n", skb);
1294 }
1295
1296 INIT_LIST_HEAD(&retval->list);
1297 retval->skb = skb;
1298 retval->asoc = (struct sctp_association *)asoc;
1299 retval->has_tsn = 0;
1300 retval->has_ssn = 0;
1301 retval->rtt_in_progress = 0;
1302 retval->sent_at = 0;
1303 retval->singleton = 1;
1304 retval->end_of_packet = 0;
1305 retval->ecn_ce_done = 0;
1306 retval->pdiscard = 0;
1307
1308 /* sctpimpguide-05.txt Section 2.8.2
1309 * M1) Each time a new DATA chunk is transmitted
1310 * set the 'TSN.Missing.Report' count for that TSN to 0. The
1311 * 'TSN.Missing.Report' count will be used to determine missing chunks
1312 * and when to fast retransmit.
1313 */
1314 retval->tsn_missing_report = 0;
1315 retval->tsn_gap_acked = 0;
1316 retval->fast_retransmit = SCTP_CAN_FRTX;
1317
1318 /* If this is a fragmented message, track all fragments
1319 * of the message (for SEND_FAILED).
1320 */
1321 retval->msg = NULL;
1322
1323 /* Polish the bead hole. */
1324 INIT_LIST_HEAD(&retval->transmitted_list);
1325 INIT_LIST_HEAD(&retval->frag_list);
1326 SCTP_DBG_OBJCNT_INC(chunk);
1327 atomic_set(&retval->refcnt, 1);
1328
1329 nodata:
1330 return retval;
1331 }
1332
1333 /* Set chunk->source and dest based on the IP header in chunk->skb. */
1334 void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src,
1335 union sctp_addr *dest)
1336 {
1337 memcpy(&chunk->source, src, sizeof(union sctp_addr));
1338 memcpy(&chunk->dest, dest, sizeof(union sctp_addr));
1339 }
1340
1341 /* Extract the source address from a chunk. */
1342 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk)
1343 {
1344 /* If we have a known transport, use that. */
1345 if (chunk->transport) {
1346 return &chunk->transport->ipaddr;
1347 } else {
1348 /* Otherwise, extract it from the IP header. */
1349 return &chunk->source;
1350 }
1351 }
1352
1353 /* Create a new chunk, setting the type and flags headers from the
1354 * arguments, reserving enough space for a 'paylen' byte payload.
1355 */
1356 SCTP_STATIC
1357 struct sctp_chunk *sctp_make_chunk(const struct sctp_association *asoc,
1358 __u8 type, __u8 flags, int paylen)
1359 {
1360 struct sctp_chunk *retval;
1361 sctp_chunkhdr_t *chunk_hdr;
1362 struct sk_buff *skb;
1363 struct sock *sk;
1364
1365 /* No need to allocate LL here, as this is only a chunk. */
1366 skb = alloc_skb(WORD_ROUND(sizeof(sctp_chunkhdr_t) + paylen),
1367 GFP_ATOMIC);
1368 if (!skb)
1369 goto nodata;
1370
1371 /* Make room for the chunk header. */
1372 chunk_hdr = (sctp_chunkhdr_t *)skb_put(skb, sizeof(sctp_chunkhdr_t));
1373 chunk_hdr->type = type;
1374 chunk_hdr->flags = flags;
1375 chunk_hdr->length = htons(sizeof(sctp_chunkhdr_t));
1376
1377 sk = asoc ? asoc->base.sk : NULL;
1378 retval = sctp_chunkify(skb, asoc, sk);
1379 if (!retval) {
1380 kfree_skb(skb);
1381 goto nodata;
1382 }
1383
1384 retval->chunk_hdr = chunk_hdr;
1385 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(struct sctp_chunkhdr);
1386
1387 /* Determine if the chunk needs to be authenticated */
1388 if (sctp_auth_send_cid(type, asoc))
1389 retval->auth = 1;
1390
1391 /* Set the skb to the belonging sock for accounting. */
1392 skb->sk = sk;
1393
1394 return retval;
1395 nodata:
1396 return NULL;
1397 }
1398
1399
1400 /* Release the memory occupied by a chunk. */
1401 static void sctp_chunk_destroy(struct sctp_chunk *chunk)
1402 {
1403 BUG_ON(!list_empty(&chunk->list));
1404 list_del_init(&chunk->transmitted_list);
1405
1406 /* Free the chunk skb data and the SCTP_chunk stub itself. */
1407 dev_kfree_skb(chunk->skb);
1408
1409 SCTP_DBG_OBJCNT_DEC(chunk);
1410 kmem_cache_free(sctp_chunk_cachep, chunk);
1411 }
1412
1413 /* Possibly, free the chunk. */
1414 void sctp_chunk_free(struct sctp_chunk *chunk)
1415 {
1416 /* Release our reference on the message tracker. */
1417 if (chunk->msg)
1418 sctp_datamsg_put(chunk->msg);
1419
1420 sctp_chunk_put(chunk);
1421 }
1422
1423 /* Grab a reference to the chunk. */
1424 void sctp_chunk_hold(struct sctp_chunk *ch)
1425 {
1426 atomic_inc(&ch->refcnt);
1427 }
1428
1429 /* Release a reference to the chunk. */
1430 void sctp_chunk_put(struct sctp_chunk *ch)
1431 {
1432 if (atomic_dec_and_test(&ch->refcnt))
1433 sctp_chunk_destroy(ch);
1434 }
1435
1436 /* Append bytes to the end of a chunk. Will panic if chunk is not big
1437 * enough.
1438 */
1439 void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data)
1440 {
1441 void *target;
1442 void *padding;
1443 int chunklen = ntohs(chunk->chunk_hdr->length);
1444 int padlen = WORD_ROUND(chunklen) - chunklen;
1445
1446 padding = skb_put(chunk->skb, padlen);
1447 target = skb_put(chunk->skb, len);
1448
1449 memset(padding, 0, padlen);
1450 memcpy(target, data, len);
1451
1452 /* Adjust the chunk length field. */
1453 chunk->chunk_hdr->length = htons(chunklen + padlen + len);
1454 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1455
1456 return target;
1457 }
1458
1459 /* Append bytes to the end of a chunk. Returns NULL if there isn't sufficient
1460 * space in the chunk
1461 */
1462 void *sctp_addto_chunk_fixed(struct sctp_chunk *chunk,
1463 int len, const void *data)
1464 {
1465 if (skb_tailroom(chunk->skb) >= len)
1466 return sctp_addto_chunk(chunk, len, data);
1467 else
1468 return NULL;
1469 }
1470
1471 /* Append bytes from user space to the end of a chunk. Will panic if
1472 * chunk is not big enough.
1473 * Returns a kernel err value.
1474 */
1475 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len,
1476 struct iovec *data)
1477 {
1478 __u8 *target;
1479 int err = 0;
1480
1481 /* Make room in chunk for data. */
1482 target = skb_put(chunk->skb, len);
1483
1484 /* Copy data (whole iovec) into chunk */
1485 if ((err = memcpy_fromiovecend(target, data, off, len)))
1486 goto out;
1487
1488 /* Adjust the chunk length field. */
1489 chunk->chunk_hdr->length =
1490 htons(ntohs(chunk->chunk_hdr->length) + len);
1491 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1492
1493 out:
1494 return err;
1495 }
1496
1497 /* Helper function to assign a TSN if needed. This assumes that both
1498 * the data_hdr and association have already been assigned.
1499 */
1500 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk)
1501 {
1502 struct sctp_datamsg *msg;
1503 struct sctp_chunk *lchunk;
1504 struct sctp_stream *stream;
1505 __u16 ssn;
1506 __u16 sid;
1507
1508 if (chunk->has_ssn)
1509 return;
1510
1511 /* All fragments will be on the same stream */
1512 sid = ntohs(chunk->subh.data_hdr->stream);
1513 stream = &chunk->asoc->ssnmap->out;
1514
1515 /* Now assign the sequence number to the entire message.
1516 * All fragments must have the same stream sequence number.
1517 */
1518 msg = chunk->msg;
1519 list_for_each_entry(lchunk, &msg->chunks, frag_list) {
1520 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
1521 ssn = 0;
1522 } else {
1523 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG)
1524 ssn = sctp_ssn_next(stream, sid);
1525 else
1526 ssn = sctp_ssn_peek(stream, sid);
1527 }
1528
1529 lchunk->subh.data_hdr->ssn = htons(ssn);
1530 lchunk->has_ssn = 1;
1531 }
1532 }
1533
1534 /* Helper function to assign a TSN if needed. This assumes that both
1535 * the data_hdr and association have already been assigned.
1536 */
1537 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk)
1538 {
1539 if (!chunk->has_tsn) {
1540 /* This is the last possible instant to
1541 * assign a TSN.
1542 */
1543 chunk->subh.data_hdr->tsn =
1544 htonl(sctp_association_get_next_tsn(chunk->asoc));
1545 chunk->has_tsn = 1;
1546 }
1547 }
1548
1549 /* Create a CLOSED association to use with an incoming packet. */
1550 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep,
1551 struct sctp_chunk *chunk,
1552 gfp_t gfp)
1553 {
1554 struct sctp_association *asoc;
1555 struct sk_buff *skb;
1556 sctp_scope_t scope;
1557 struct sctp_af *af;
1558
1559 /* Create the bare association. */
1560 scope = sctp_scope(sctp_source(chunk));
1561 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp);
1562 if (!asoc)
1563 goto nodata;
1564 asoc->temp = 1;
1565 skb = chunk->skb;
1566 /* Create an entry for the source address of the packet. */
1567 af = sctp_get_af_specific(ipver2af(ip_hdr(skb)->version));
1568 if (unlikely(!af))
1569 goto fail;
1570 af->from_skb(&asoc->c.peer_addr, skb, 1);
1571 nodata:
1572 return asoc;
1573
1574 fail:
1575 sctp_association_free(asoc);
1576 return NULL;
1577 }
1578
1579 /* Build a cookie representing asoc.
1580 * This INCLUDES the param header needed to put the cookie in the INIT ACK.
1581 */
1582 static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep,
1583 const struct sctp_association *asoc,
1584 const struct sctp_chunk *init_chunk,
1585 int *cookie_len,
1586 const __u8 *raw_addrs, int addrs_len)
1587 {
1588 sctp_cookie_param_t *retval;
1589 struct sctp_signed_cookie *cookie;
1590 struct scatterlist sg;
1591 int headersize, bodysize;
1592
1593 /* Header size is static data prior to the actual cookie, including
1594 * any padding.
1595 */
1596 headersize = sizeof(sctp_paramhdr_t) +
1597 (sizeof(struct sctp_signed_cookie) -
1598 sizeof(struct sctp_cookie));
1599 bodysize = sizeof(struct sctp_cookie)
1600 + ntohs(init_chunk->chunk_hdr->length) + addrs_len;
1601
1602 /* Pad out the cookie to a multiple to make the signature
1603 * functions simpler to write.
1604 */
1605 if (bodysize % SCTP_COOKIE_MULTIPLE)
1606 bodysize += SCTP_COOKIE_MULTIPLE
1607 - (bodysize % SCTP_COOKIE_MULTIPLE);
1608 *cookie_len = headersize + bodysize;
1609
1610 /* Clear this memory since we are sending this data structure
1611 * out on the network.
1612 */
1613 retval = kzalloc(*cookie_len, GFP_ATOMIC);
1614 if (!retval)
1615 goto nodata;
1616
1617 cookie = (struct sctp_signed_cookie *) retval->body;
1618
1619 /* Set up the parameter header. */
1620 retval->p.type = SCTP_PARAM_STATE_COOKIE;
1621 retval->p.length = htons(*cookie_len);
1622
1623 /* Copy the cookie part of the association itself. */
1624 cookie->c = asoc->c;
1625 /* Save the raw address list length in the cookie. */
1626 cookie->c.raw_addr_list_len = addrs_len;
1627
1628 /* Remember PR-SCTP capability. */
1629 cookie->c.prsctp_capable = asoc->peer.prsctp_capable;
1630
1631 /* Save adaptation indication in the cookie. */
1632 cookie->c.adaptation_ind = asoc->peer.adaptation_ind;
1633
1634 /* Set an expiration time for the cookie. */
1635 do_gettimeofday(&cookie->c.expiration);
1636 TIMEVAL_ADD(asoc->cookie_life, cookie->c.expiration);
1637
1638 /* Copy the peer's init packet. */
1639 memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr,
1640 ntohs(init_chunk->chunk_hdr->length));
1641
1642 /* Copy the raw local address list of the association. */
1643 memcpy((__u8 *)&cookie->c.peer_init[0] +
1644 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len);
1645
1646 if (sctp_sk(ep->base.sk)->hmac) {
1647 struct hash_desc desc;
1648
1649 /* Sign the message. */
1650 sg_init_one(&sg, &cookie->c, bodysize);
1651 desc.tfm = sctp_sk(ep->base.sk)->hmac;
1652 desc.flags = 0;
1653
1654 if (crypto_hash_setkey(desc.tfm, ep->secret_key,
1655 sizeof(ep->secret_key)) ||
1656 crypto_hash_digest(&desc, &sg, bodysize, cookie->signature))
1657 goto free_cookie;
1658 }
1659
1660 return retval;
1661
1662 free_cookie:
1663 kfree(retval);
1664 nodata:
1665 *cookie_len = 0;
1666 return NULL;
1667 }
1668
1669 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */
1670 struct sctp_association *sctp_unpack_cookie(
1671 const struct sctp_endpoint *ep,
1672 const struct sctp_association *asoc,
1673 struct sctp_chunk *chunk, gfp_t gfp,
1674 int *error, struct sctp_chunk **errp)
1675 {
1676 struct sctp_association *retval = NULL;
1677 struct sctp_signed_cookie *cookie;
1678 struct sctp_cookie *bear_cookie;
1679 int headersize, bodysize, fixed_size;
1680 __u8 *digest = ep->digest;
1681 struct scatterlist sg;
1682 unsigned int len;
1683 sctp_scope_t scope;
1684 struct sk_buff *skb = chunk->skb;
1685 struct timeval tv;
1686 struct hash_desc desc;
1687
1688 /* Header size is static data prior to the actual cookie, including
1689 * any padding.
1690 */
1691 headersize = sizeof(sctp_chunkhdr_t) +
1692 (sizeof(struct sctp_signed_cookie) -
1693 sizeof(struct sctp_cookie));
1694 bodysize = ntohs(chunk->chunk_hdr->length) - headersize;
1695 fixed_size = headersize + sizeof(struct sctp_cookie);
1696
1697 /* Verify that the chunk looks like it even has a cookie.
1698 * There must be enough room for our cookie and our peer's
1699 * INIT chunk.
1700 */
1701 len = ntohs(chunk->chunk_hdr->length);
1702 if (len < fixed_size + sizeof(struct sctp_chunkhdr))
1703 goto malformed;
1704
1705 /* Verify that the cookie has been padded out. */
1706 if (bodysize % SCTP_COOKIE_MULTIPLE)
1707 goto malformed;
1708
1709 /* Process the cookie. */
1710 cookie = chunk->subh.cookie_hdr;
1711 bear_cookie = &cookie->c;
1712
1713 if (!sctp_sk(ep->base.sk)->hmac)
1714 goto no_hmac;
1715
1716 /* Check the signature. */
1717 sg_init_one(&sg, bear_cookie, bodysize);
1718 desc.tfm = sctp_sk(ep->base.sk)->hmac;
1719 desc.flags = 0;
1720
1721 memset(digest, 0x00, SCTP_SIGNATURE_SIZE);
1722 if (crypto_hash_setkey(desc.tfm, ep->secret_key,
1723 sizeof(ep->secret_key)) ||
1724 crypto_hash_digest(&desc, &sg, bodysize, digest)) {
1725 *error = -SCTP_IERROR_NOMEM;
1726 goto fail;
1727 }
1728
1729 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
1730 *error = -SCTP_IERROR_BAD_SIG;
1731 goto fail;
1732 }
1733
1734 no_hmac:
1735 /* IG Section 2.35.2:
1736 * 3) Compare the port numbers and the verification tag contained
1737 * within the COOKIE ECHO chunk to the actual port numbers and the
1738 * verification tag within the SCTP common header of the received
1739 * packet. If these values do not match the packet MUST be silently
1740 * discarded,
1741 */
1742 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) {
1743 *error = -SCTP_IERROR_BAD_TAG;
1744 goto fail;
1745 }
1746
1747 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port ||
1748 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) {
1749 *error = -SCTP_IERROR_BAD_PORTS;
1750 goto fail;
1751 }
1752
1753 /* Check to see if the cookie is stale. If there is already
1754 * an association, there is no need to check cookie's expiration
1755 * for init collision case of lost COOKIE ACK.
1756 * If skb has been timestamped, then use the stamp, otherwise
1757 * use current time. This introduces a small possibility that
1758 * that a cookie may be considered expired, but his would only slow
1759 * down the new association establishment instead of every packet.
1760 */
1761 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP))
1762 skb_get_timestamp(skb, &tv);
1763 else
1764 do_gettimeofday(&tv);
1765
1766 if (!asoc && tv_lt(bear_cookie->expiration, tv)) {
1767 /*
1768 * Section 3.3.10.3 Stale Cookie Error (3)
1769 *
1770 * Cause of error
1771 * ---------------
1772 * Stale Cookie Error: Indicates the receipt of a valid State
1773 * Cookie that has expired.
1774 */
1775 len = ntohs(chunk->chunk_hdr->length);
1776 *errp = sctp_make_op_error_space(asoc, chunk, len);
1777 if (*errp) {
1778 suseconds_t usecs = (tv.tv_sec -
1779 bear_cookie->expiration.tv_sec) * 1000000L +
1780 tv.tv_usec - bear_cookie->expiration.tv_usec;
1781 __be32 n = htonl(usecs);
1782
1783 sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE,
1784 sizeof(n));
1785 sctp_addto_chunk(*errp, sizeof(n), &n);
1786 *error = -SCTP_IERROR_STALE_COOKIE;
1787 } else
1788 *error = -SCTP_IERROR_NOMEM;
1789
1790 goto fail;
1791 }
1792
1793 /* Make a new base association. */
1794 scope = sctp_scope(sctp_source(chunk));
1795 retval = sctp_association_new(ep, ep->base.sk, scope, gfp);
1796 if (!retval) {
1797 *error = -SCTP_IERROR_NOMEM;
1798 goto fail;
1799 }
1800
1801 /* Set up our peer's port number. */
1802 retval->peer.port = ntohs(chunk->sctp_hdr->source);
1803
1804 /* Populate the association from the cookie. */
1805 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie));
1806
1807 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie,
1808 GFP_ATOMIC) < 0) {
1809 *error = -SCTP_IERROR_NOMEM;
1810 goto fail;
1811 }
1812
1813 /* Also, add the destination address. */
1814 if (list_empty(&retval->base.bind_addr.address_list)) {
1815 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest,
1816 SCTP_ADDR_SRC, GFP_ATOMIC);
1817 }
1818
1819 retval->next_tsn = retval->c.initial_tsn;
1820 retval->ctsn_ack_point = retval->next_tsn - 1;
1821 retval->addip_serial = retval->c.initial_tsn;
1822 retval->adv_peer_ack_point = retval->ctsn_ack_point;
1823 retval->peer.prsctp_capable = retval->c.prsctp_capable;
1824 retval->peer.adaptation_ind = retval->c.adaptation_ind;
1825
1826 /* The INIT stuff will be done by the side effects. */
1827 return retval;
1828
1829 fail:
1830 if (retval)
1831 sctp_association_free(retval);
1832
1833 return NULL;
1834
1835 malformed:
1836 /* Yikes! The packet is either corrupt or deliberately
1837 * malformed.
1838 */
1839 *error = -SCTP_IERROR_MALFORMED;
1840 goto fail;
1841 }
1842
1843 /********************************************************************
1844 * 3rd Level Abstractions
1845 ********************************************************************/
1846
1847 struct __sctp_missing {
1848 __be32 num_missing;
1849 __be16 type;
1850 } __packed;
1851
1852 /*
1853 * Report a missing mandatory parameter.
1854 */
1855 static int sctp_process_missing_param(const struct sctp_association *asoc,
1856 sctp_param_t paramtype,
1857 struct sctp_chunk *chunk,
1858 struct sctp_chunk **errp)
1859 {
1860 struct __sctp_missing report;
1861 __u16 len;
1862
1863 len = WORD_ROUND(sizeof(report));
1864
1865 /* Make an ERROR chunk, preparing enough room for
1866 * returning multiple unknown parameters.
1867 */
1868 if (!*errp)
1869 *errp = sctp_make_op_error_space(asoc, chunk, len);
1870
1871 if (*errp) {
1872 report.num_missing = htonl(1);
1873 report.type = paramtype;
1874 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM,
1875 sizeof(report));
1876 sctp_addto_chunk(*errp, sizeof(report), &report);
1877 }
1878
1879 /* Stop processing this chunk. */
1880 return 0;
1881 }
1882
1883 /* Report an Invalid Mandatory Parameter. */
1884 static int sctp_process_inv_mandatory(const struct sctp_association *asoc,
1885 struct sctp_chunk *chunk,
1886 struct sctp_chunk **errp)
1887 {
1888 /* Invalid Mandatory Parameter Error has no payload. */
1889
1890 if (!*errp)
1891 *errp = sctp_make_op_error_space(asoc, chunk, 0);
1892
1893 if (*errp)
1894 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0);
1895
1896 /* Stop processing this chunk. */
1897 return 0;
1898 }
1899
1900 static int sctp_process_inv_paramlength(const struct sctp_association *asoc,
1901 struct sctp_paramhdr *param,
1902 const struct sctp_chunk *chunk,
1903 struct sctp_chunk **errp)
1904 {
1905 /* This is a fatal error. Any accumulated non-fatal errors are
1906 * not reported.
1907 */
1908 if (*errp)
1909 sctp_chunk_free(*errp);
1910
1911 /* Create an error chunk and fill it in with our payload. */
1912 *errp = sctp_make_violation_paramlen(asoc, chunk, param);
1913
1914 return 0;
1915 }
1916
1917
1918 /* Do not attempt to handle the HOST_NAME parm. However, do
1919 * send back an indicator to the peer.
1920 */
1921 static int sctp_process_hn_param(const struct sctp_association *asoc,
1922 union sctp_params param,
1923 struct sctp_chunk *chunk,
1924 struct sctp_chunk **errp)
1925 {
1926 __u16 len = ntohs(param.p->length);
1927
1928 /* Processing of the HOST_NAME parameter will generate an
1929 * ABORT. If we've accumulated any non-fatal errors, they
1930 * would be unrecognized parameters and we should not include
1931 * them in the ABORT.
1932 */
1933 if (*errp)
1934 sctp_chunk_free(*errp);
1935
1936 *errp = sctp_make_op_error_space(asoc, chunk, len);
1937
1938 if (*errp) {
1939 sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, len);
1940 sctp_addto_chunk(*errp, len, param.v);
1941 }
1942
1943 /* Stop processing this chunk. */
1944 return 0;
1945 }
1946
1947 static int sctp_verify_ext_param(struct net *net, union sctp_params param)
1948 {
1949 __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
1950 int have_auth = 0;
1951 int have_asconf = 0;
1952 int i;
1953
1954 for (i = 0; i < num_ext; i++) {
1955 switch (param.ext->chunks[i]) {
1956 case SCTP_CID_AUTH:
1957 have_auth = 1;
1958 break;
1959 case SCTP_CID_ASCONF:
1960 case SCTP_CID_ASCONF_ACK:
1961 have_asconf = 1;
1962 break;
1963 }
1964 }
1965
1966 /* ADD-IP Security: The draft requires us to ABORT or ignore the
1967 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this
1968 * only if ADD-IP is turned on and we are not backward-compatible
1969 * mode.
1970 */
1971 if (net->sctp.addip_noauth)
1972 return 1;
1973
1974 if (net->sctp.addip_enable && !have_auth && have_asconf)
1975 return 0;
1976
1977 return 1;
1978 }
1979
1980 static void sctp_process_ext_param(struct sctp_association *asoc,
1981 union sctp_params param)
1982 {
1983 struct net *net = sock_net(asoc->base.sk);
1984 __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
1985 int i;
1986
1987 for (i = 0; i < num_ext; i++) {
1988 switch (param.ext->chunks[i]) {
1989 case SCTP_CID_FWD_TSN:
1990 if (net->sctp.prsctp_enable &&
1991 !asoc->peer.prsctp_capable)
1992 asoc->peer.prsctp_capable = 1;
1993 break;
1994 case SCTP_CID_AUTH:
1995 /* if the peer reports AUTH, assume that he
1996 * supports AUTH.
1997 */
1998 if (net->sctp.auth_enable)
1999 asoc->peer.auth_capable = 1;
2000 break;
2001 case SCTP_CID_ASCONF:
2002 case SCTP_CID_ASCONF_ACK:
2003 if (net->sctp.addip_enable)
2004 asoc->peer.asconf_capable = 1;
2005 break;
2006 default:
2007 break;
2008 }
2009 }
2010 }
2011
2012 /* RFC 3.2.1 & the Implementers Guide 2.2.
2013 *
2014 * The Parameter Types are encoded such that the
2015 * highest-order two bits specify the action that must be
2016 * taken if the processing endpoint does not recognize the
2017 * Parameter Type.
2018 *
2019 * 00 - Stop processing this parameter; do not process any further
2020 * parameters within this chunk
2021 *
2022 * 01 - Stop processing this parameter, do not process any further
2023 * parameters within this chunk, and report the unrecognized
2024 * parameter in an 'Unrecognized Parameter' ERROR chunk.
2025 *
2026 * 10 - Skip this parameter and continue processing.
2027 *
2028 * 11 - Skip this parameter and continue processing but
2029 * report the unrecognized parameter in an
2030 * 'Unrecognized Parameter' ERROR chunk.
2031 *
2032 * Return value:
2033 * SCTP_IERROR_NO_ERROR - continue with the chunk
2034 * SCTP_IERROR_ERROR - stop and report an error.
2035 * SCTP_IERROR_NOMEME - out of memory.
2036 */
2037 static sctp_ierror_t sctp_process_unk_param(const struct sctp_association *asoc,
2038 union sctp_params param,
2039 struct sctp_chunk *chunk,
2040 struct sctp_chunk **errp)
2041 {
2042 int retval = SCTP_IERROR_NO_ERROR;
2043
2044 switch (param.p->type & SCTP_PARAM_ACTION_MASK) {
2045 case SCTP_PARAM_ACTION_DISCARD:
2046 retval = SCTP_IERROR_ERROR;
2047 break;
2048 case SCTP_PARAM_ACTION_SKIP:
2049 break;
2050 case SCTP_PARAM_ACTION_DISCARD_ERR:
2051 retval = SCTP_IERROR_ERROR;
2052 /* Fall through */
2053 case SCTP_PARAM_ACTION_SKIP_ERR:
2054 /* Make an ERROR chunk, preparing enough room for
2055 * returning multiple unknown parameters.
2056 */
2057 if (NULL == *errp)
2058 *errp = sctp_make_op_error_fixed(asoc, chunk);
2059
2060 if (*errp) {
2061 if (!sctp_init_cause_fixed(*errp, SCTP_ERROR_UNKNOWN_PARAM,
2062 WORD_ROUND(ntohs(param.p->length))))
2063 sctp_addto_chunk_fixed(*errp,
2064 WORD_ROUND(ntohs(param.p->length)),
2065 param.v);
2066 } else {
2067 /* If there is no memory for generating the ERROR
2068 * report as specified, an ABORT will be triggered
2069 * to the peer and the association won't be
2070 * established.
2071 */
2072 retval = SCTP_IERROR_NOMEM;
2073 }
2074 break;
2075 default:
2076 break;
2077 }
2078
2079 return retval;
2080 }
2081
2082 /* Verify variable length parameters
2083 * Return values:
2084 * SCTP_IERROR_ABORT - trigger an ABORT
2085 * SCTP_IERROR_NOMEM - out of memory (abort)
2086 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR
2087 * SCTP_IERROR_NO_ERROR - continue with the chunk
2088 */
2089 static sctp_ierror_t sctp_verify_param(struct net *net,
2090 const struct sctp_association *asoc,
2091 union sctp_params param,
2092 sctp_cid_t cid,
2093 struct sctp_chunk *chunk,
2094 struct sctp_chunk **err_chunk)
2095 {
2096 struct sctp_hmac_algo_param *hmacs;
2097 int retval = SCTP_IERROR_NO_ERROR;
2098 __u16 n_elt, id = 0;
2099 int i;
2100
2101 /* FIXME - This routine is not looking at each parameter per the
2102 * chunk type, i.e., unrecognized parameters should be further
2103 * identified based on the chunk id.
2104 */
2105
2106 switch (param.p->type) {
2107 case SCTP_PARAM_IPV4_ADDRESS:
2108 case SCTP_PARAM_IPV6_ADDRESS:
2109 case SCTP_PARAM_COOKIE_PRESERVATIVE:
2110 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
2111 case SCTP_PARAM_STATE_COOKIE:
2112 case SCTP_PARAM_HEARTBEAT_INFO:
2113 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
2114 case SCTP_PARAM_ECN_CAPABLE:
2115 case SCTP_PARAM_ADAPTATION_LAYER_IND:
2116 break;
2117
2118 case SCTP_PARAM_SUPPORTED_EXT:
2119 if (!sctp_verify_ext_param(net, param))
2120 return SCTP_IERROR_ABORT;
2121 break;
2122
2123 case SCTP_PARAM_SET_PRIMARY:
2124 if (net->sctp.addip_enable)
2125 break;
2126 goto fallthrough;
2127
2128 case SCTP_PARAM_HOST_NAME_ADDRESS:
2129 /* Tell the peer, we won't support this param. */
2130 sctp_process_hn_param(asoc, param, chunk, err_chunk);
2131 retval = SCTP_IERROR_ABORT;
2132 break;
2133
2134 case SCTP_PARAM_FWD_TSN_SUPPORT:
2135 if (net->sctp.prsctp_enable)
2136 break;
2137 goto fallthrough;
2138
2139 case SCTP_PARAM_RANDOM:
2140 if (!net->sctp.auth_enable)
2141 goto fallthrough;
2142
2143 /* SCTP-AUTH: Secion 6.1
2144 * If the random number is not 32 byte long the association
2145 * MUST be aborted. The ABORT chunk SHOULD contain the error
2146 * cause 'Protocol Violation'.
2147 */
2148 if (SCTP_AUTH_RANDOM_LENGTH !=
2149 ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) {
2150 sctp_process_inv_paramlength(asoc, param.p,
2151 chunk, err_chunk);
2152 retval = SCTP_IERROR_ABORT;
2153 }
2154 break;
2155
2156 case SCTP_PARAM_CHUNKS:
2157 if (!net->sctp.auth_enable)
2158 goto fallthrough;
2159
2160 /* SCTP-AUTH: Section 3.2
2161 * The CHUNKS parameter MUST be included once in the INIT or
2162 * INIT-ACK chunk if the sender wants to receive authenticated
2163 * chunks. Its maximum length is 260 bytes.
2164 */
2165 if (260 < ntohs(param.p->length)) {
2166 sctp_process_inv_paramlength(asoc, param.p,
2167 chunk, err_chunk);
2168 retval = SCTP_IERROR_ABORT;
2169 }
2170 break;
2171
2172 case SCTP_PARAM_HMAC_ALGO:
2173 if (!net->sctp.auth_enable)
2174 goto fallthrough;
2175
2176 hmacs = (struct sctp_hmac_algo_param *)param.p;
2177 n_elt = (ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) >> 1;
2178
2179 /* SCTP-AUTH: Section 6.1
2180 * The HMAC algorithm based on SHA-1 MUST be supported and
2181 * included in the HMAC-ALGO parameter.
2182 */
2183 for (i = 0; i < n_elt; i++) {
2184 id = ntohs(hmacs->hmac_ids[i]);
2185
2186 if (id == SCTP_AUTH_HMAC_ID_SHA1)
2187 break;
2188 }
2189
2190 if (id != SCTP_AUTH_HMAC_ID_SHA1) {
2191 sctp_process_inv_paramlength(asoc, param.p, chunk,
2192 err_chunk);
2193 retval = SCTP_IERROR_ABORT;
2194 }
2195 break;
2196 fallthrough:
2197 default:
2198 SCTP_DEBUG_PRINTK("Unrecognized param: %d for chunk %d.\n",
2199 ntohs(param.p->type), cid);
2200 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk);
2201 break;
2202 }
2203 return retval;
2204 }
2205
2206 /* Verify the INIT packet before we process it. */
2207 int sctp_verify_init(struct net *net, const struct sctp_association *asoc,
2208 sctp_cid_t cid,
2209 sctp_init_chunk_t *peer_init,
2210 struct sctp_chunk *chunk,
2211 struct sctp_chunk **errp)
2212 {
2213 union sctp_params param;
2214 int has_cookie = 0;
2215 int result;
2216
2217 /* Verify stream values are non-zero. */
2218 if ((0 == peer_init->init_hdr.num_outbound_streams) ||
2219 (0 == peer_init->init_hdr.num_inbound_streams) ||
2220 (0 == peer_init->init_hdr.init_tag) ||
2221 (SCTP_DEFAULT_MINWINDOW > ntohl(peer_init->init_hdr.a_rwnd))) {
2222
2223 return sctp_process_inv_mandatory(asoc, chunk, errp);
2224 }
2225
2226 /* Check for missing mandatory parameters. */
2227 sctp_walk_params(param, peer_init, init_hdr.params) {
2228
2229 if (SCTP_PARAM_STATE_COOKIE == param.p->type)
2230 has_cookie = 1;
2231
2232 } /* for (loop through all parameters) */
2233
2234 /* There is a possibility that a parameter length was bad and
2235 * in that case we would have stoped walking the parameters.
2236 * The current param.p would point at the bad one.
2237 * Current consensus on the mailing list is to generate a PROTOCOL
2238 * VIOLATION error. We build the ERROR chunk here and let the normal
2239 * error handling code build and send the packet.
2240 */
2241 if (param.v != (void*)chunk->chunk_end)
2242 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp);
2243
2244 /* The only missing mandatory param possible today is
2245 * the state cookie for an INIT-ACK chunk.
2246 */
2247 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie)
2248 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE,
2249 chunk, errp);
2250
2251 /* Verify all the variable length parameters */
2252 sctp_walk_params(param, peer_init, init_hdr.params) {
2253
2254 result = sctp_verify_param(net, asoc, param, cid, chunk, errp);
2255 switch (result) {
2256 case SCTP_IERROR_ABORT:
2257 case SCTP_IERROR_NOMEM:
2258 return 0;
2259 case SCTP_IERROR_ERROR:
2260 return 1;
2261 case SCTP_IERROR_NO_ERROR:
2262 default:
2263 break;
2264 }
2265
2266 } /* for (loop through all parameters) */
2267
2268 return 1;
2269 }
2270
2271 /* Unpack the parameters in an INIT packet into an association.
2272 * Returns 0 on failure, else success.
2273 * FIXME: This is an association method.
2274 */
2275 int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk,
2276 const union sctp_addr *peer_addr,
2277 sctp_init_chunk_t *peer_init, gfp_t gfp)
2278 {
2279 struct net *net = sock_net(asoc->base.sk);
2280 union sctp_params param;
2281 struct sctp_transport *transport;
2282 struct list_head *pos, *temp;
2283 struct sctp_af *af;
2284 union sctp_addr addr;
2285 char *cookie;
2286 int src_match = 0;
2287
2288 /* We must include the address that the INIT packet came from.
2289 * This is the only address that matters for an INIT packet.
2290 * When processing a COOKIE ECHO, we retrieve the from address
2291 * of the INIT from the cookie.
2292 */
2293
2294 /* This implementation defaults to making the first transport
2295 * added as the primary transport. The source address seems to
2296 * be a a better choice than any of the embedded addresses.
2297 */
2298 if(!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE))
2299 goto nomem;
2300
2301 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr))
2302 src_match = 1;
2303
2304 /* Process the initialization parameters. */
2305 sctp_walk_params(param, peer_init, init_hdr.params) {
2306 if (!src_match && (param.p->type == SCTP_PARAM_IPV4_ADDRESS ||
2307 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) {
2308 af = sctp_get_af_specific(param_type2af(param.p->type));
2309 af->from_addr_param(&addr, param.addr,
2310 chunk->sctp_hdr->source, 0);
2311 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr))
2312 src_match = 1;
2313 }
2314
2315 if (!sctp_process_param(asoc, param, peer_addr, gfp))
2316 goto clean_up;
2317 }
2318
2319 /* source address of chunk may not match any valid address */
2320 if (!src_match)
2321 goto clean_up;
2322
2323 /* AUTH: After processing the parameters, make sure that we
2324 * have all the required info to potentially do authentications.
2325 */
2326 if (asoc->peer.auth_capable && (!asoc->peer.peer_random ||
2327 !asoc->peer.peer_hmacs))
2328 asoc->peer.auth_capable = 0;
2329
2330 /* In a non-backward compatible mode, if the peer claims
2331 * support for ADD-IP but not AUTH, the ADD-IP spec states
2332 * that we MUST ABORT the association. Section 6. The section
2333 * also give us an option to silently ignore the packet, which
2334 * is what we'll do here.
2335 */
2336 if (!net->sctp.addip_noauth &&
2337 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) {
2338 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP |
2339 SCTP_PARAM_DEL_IP |
2340 SCTP_PARAM_SET_PRIMARY);
2341 asoc->peer.asconf_capable = 0;
2342 goto clean_up;
2343 }
2344
2345 /* Walk list of transports, removing transports in the UNKNOWN state. */
2346 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
2347 transport = list_entry(pos, struct sctp_transport, transports);
2348 if (transport->state == SCTP_UNKNOWN) {
2349 sctp_assoc_rm_peer(asoc, transport);
2350 }
2351 }
2352
2353 /* The fixed INIT headers are always in network byte
2354 * order.
2355 */
2356 asoc->peer.i.init_tag =
2357 ntohl(peer_init->init_hdr.init_tag);
2358 asoc->peer.i.a_rwnd =
2359 ntohl(peer_init->init_hdr.a_rwnd);
2360 asoc->peer.i.num_outbound_streams =
2361 ntohs(peer_init->init_hdr.num_outbound_streams);
2362 asoc->peer.i.num_inbound_streams =
2363 ntohs(peer_init->init_hdr.num_inbound_streams);
2364 asoc->peer.i.initial_tsn =
2365 ntohl(peer_init->init_hdr.initial_tsn);
2366
2367 /* Apply the upper bounds for output streams based on peer's
2368 * number of inbound streams.
2369 */
2370 if (asoc->c.sinit_num_ostreams >
2371 ntohs(peer_init->init_hdr.num_inbound_streams)) {
2372 asoc->c.sinit_num_ostreams =
2373 ntohs(peer_init->init_hdr.num_inbound_streams);
2374 }
2375
2376 if (asoc->c.sinit_max_instreams >
2377 ntohs(peer_init->init_hdr.num_outbound_streams)) {
2378 asoc->c.sinit_max_instreams =
2379 ntohs(peer_init->init_hdr.num_outbound_streams);
2380 }
2381
2382 /* Copy Initiation tag from INIT to VT_peer in cookie. */
2383 asoc->c.peer_vtag = asoc->peer.i.init_tag;
2384
2385 /* Peer Rwnd : Current calculated value of the peer's rwnd. */
2386 asoc->peer.rwnd = asoc->peer.i.a_rwnd;
2387
2388 /* Copy cookie in case we need to resend COOKIE-ECHO. */
2389 cookie = asoc->peer.cookie;
2390 if (cookie) {
2391 asoc->peer.cookie = kmemdup(cookie, asoc->peer.cookie_len, gfp);
2392 if (!asoc->peer.cookie)
2393 goto clean_up;
2394 }
2395
2396 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily
2397 * high (for example, implementations MAY use the size of the receiver
2398 * advertised window).
2399 */
2400 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
2401 transports) {
2402 transport->ssthresh = asoc->peer.i.a_rwnd;
2403 }
2404
2405 /* Set up the TSN tracking pieces. */
2406 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
2407 asoc->peer.i.initial_tsn, gfp))
2408 goto clean_up;
2409
2410 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
2411 *
2412 * The stream sequence number in all the streams shall start
2413 * from 0 when the association is established. Also, when the
2414 * stream sequence number reaches the value 65535 the next
2415 * stream sequence number shall be set to 0.
2416 */
2417
2418 /* Allocate storage for the negotiated streams if it is not a temporary
2419 * association.
2420 */
2421 if (!asoc->temp) {
2422 int error;
2423
2424 asoc->ssnmap = sctp_ssnmap_new(asoc->c.sinit_max_instreams,
2425 asoc->c.sinit_num_ostreams, gfp);
2426 if (!asoc->ssnmap)
2427 goto clean_up;
2428
2429 error = sctp_assoc_set_id(asoc, gfp);
2430 if (error)
2431 goto clean_up;
2432 }
2433
2434 /* ADDIP Section 4.1 ASCONF Chunk Procedures
2435 *
2436 * When an endpoint has an ASCONF signaled change to be sent to the
2437 * remote endpoint it should do the following:
2438 * ...
2439 * A2) A serial number should be assigned to the Chunk. The serial
2440 * number should be a monotonically increasing number. All serial
2441 * numbers are defined to be initialized at the start of the
2442 * association to the same value as the Initial TSN.
2443 */
2444 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1;
2445 return 1;
2446
2447 clean_up:
2448 /* Release the transport structures. */
2449 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
2450 transport = list_entry(pos, struct sctp_transport, transports);
2451 if (transport->state != SCTP_ACTIVE)
2452 sctp_assoc_rm_peer(asoc, transport);
2453 }
2454
2455 nomem:
2456 return 0;
2457 }
2458
2459
2460 /* Update asoc with the option described in param.
2461 *
2462 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT
2463 *
2464 * asoc is the association to update.
2465 * param is the variable length parameter to use for update.
2466 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO.
2467 * If the current packet is an INIT we want to minimize the amount of
2468 * work we do. In particular, we should not build transport
2469 * structures for the addresses.
2470 */
2471 static int sctp_process_param(struct sctp_association *asoc,
2472 union sctp_params param,
2473 const union sctp_addr *peer_addr,
2474 gfp_t gfp)
2475 {
2476 struct net *net = sock_net(asoc->base.sk);
2477 union sctp_addr addr;
2478 int i;
2479 __u16 sat;
2480 int retval = 1;
2481 sctp_scope_t scope;
2482 time_t stale;
2483 struct sctp_af *af;
2484 union sctp_addr_param *addr_param;
2485 struct sctp_transport *t;
2486
2487 /* We maintain all INIT parameters in network byte order all the
2488 * time. This allows us to not worry about whether the parameters
2489 * came from a fresh INIT, and INIT ACK, or were stored in a cookie.
2490 */
2491 switch (param.p->type) {
2492 case SCTP_PARAM_IPV6_ADDRESS:
2493 if (PF_INET6 != asoc->base.sk->sk_family)
2494 break;
2495 goto do_addr_param;
2496
2497 case SCTP_PARAM_IPV4_ADDRESS:
2498 /* v4 addresses are not allowed on v6-only socket */
2499 if (ipv6_only_sock(asoc->base.sk))
2500 break;
2501 do_addr_param:
2502 af = sctp_get_af_specific(param_type2af(param.p->type));
2503 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0);
2504 scope = sctp_scope(peer_addr);
2505 if (sctp_in_scope(net, &addr, scope))
2506 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED))
2507 return 0;
2508 break;
2509
2510 case SCTP_PARAM_COOKIE_PRESERVATIVE:
2511 if (!net->sctp.cookie_preserve_enable)
2512 break;
2513
2514 stale = ntohl(param.life->lifespan_increment);
2515
2516 /* Suggested Cookie Life span increment's unit is msec,
2517 * (1/1000sec).
2518 */
2519 asoc->cookie_life.tv_sec += stale / 1000;
2520 asoc->cookie_life.tv_usec += (stale % 1000) * 1000;
2521 break;
2522
2523 case SCTP_PARAM_HOST_NAME_ADDRESS:
2524 SCTP_DEBUG_PRINTK("unimplemented SCTP_HOST_NAME_ADDRESS\n");
2525 break;
2526
2527 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
2528 /* Turn off the default values first so we'll know which
2529 * ones are really set by the peer.
2530 */
2531 asoc->peer.ipv4_address = 0;
2532 asoc->peer.ipv6_address = 0;
2533
2534 /* Assume that peer supports the address family
2535 * by which it sends a packet.
2536 */
2537 if (peer_addr->sa.sa_family == AF_INET6)
2538 asoc->peer.ipv6_address = 1;
2539 else if (peer_addr->sa.sa_family == AF_INET)
2540 asoc->peer.ipv4_address = 1;
2541
2542 /* Cycle through address types; avoid divide by 0. */
2543 sat = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
2544 if (sat)
2545 sat /= sizeof(__u16);
2546
2547 for (i = 0; i < sat; ++i) {
2548 switch (param.sat->types[i]) {
2549 case SCTP_PARAM_IPV4_ADDRESS:
2550 asoc->peer.ipv4_address = 1;
2551 break;
2552
2553 case SCTP_PARAM_IPV6_ADDRESS:
2554 if (PF_INET6 == asoc->base.sk->sk_family)
2555 asoc->peer.ipv6_address = 1;
2556 break;
2557
2558 case SCTP_PARAM_HOST_NAME_ADDRESS:
2559 asoc->peer.hostname_address = 1;
2560 break;
2561
2562 default: /* Just ignore anything else. */
2563 break;
2564 }
2565 }
2566 break;
2567
2568 case SCTP_PARAM_STATE_COOKIE:
2569 asoc->peer.cookie_len =
2570 ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
2571 asoc->peer.cookie = param.cookie->body;
2572 break;
2573
2574 case SCTP_PARAM_HEARTBEAT_INFO:
2575 /* Would be odd to receive, but it causes no problems. */
2576 break;
2577
2578 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
2579 /* Rejected during verify stage. */
2580 break;
2581
2582 case SCTP_PARAM_ECN_CAPABLE:
2583 asoc->peer.ecn_capable = 1;
2584 break;
2585
2586 case SCTP_PARAM_ADAPTATION_LAYER_IND:
2587 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind);
2588 break;
2589
2590 case SCTP_PARAM_SET_PRIMARY:
2591 if (!net->sctp.addip_enable)
2592 goto fall_through;
2593
2594 addr_param = param.v + sizeof(sctp_addip_param_t);
2595
2596 af = sctp_get_af_specific(param_type2af(param.p->type));
2597 af->from_addr_param(&addr, addr_param,
2598 htons(asoc->peer.port), 0);
2599
2600 /* if the address is invalid, we can't process it.
2601 * XXX: see spec for what to do.
2602 */
2603 if (!af->addr_valid(&addr, NULL, NULL))
2604 break;
2605
2606 t = sctp_assoc_lookup_paddr(asoc, &addr);
2607 if (!t)
2608 break;
2609
2610 sctp_assoc_set_primary(asoc, t);
2611 break;
2612
2613 case SCTP_PARAM_SUPPORTED_EXT:
2614 sctp_process_ext_param(asoc, param);
2615 break;
2616
2617 case SCTP_PARAM_FWD_TSN_SUPPORT:
2618 if (net->sctp.prsctp_enable) {
2619 asoc->peer.prsctp_capable = 1;
2620 break;
2621 }
2622 /* Fall Through */
2623 goto fall_through;
2624
2625 case SCTP_PARAM_RANDOM:
2626 if (!net->sctp.auth_enable)
2627 goto fall_through;
2628
2629 /* Save peer's random parameter */
2630 asoc->peer.peer_random = kmemdup(param.p,
2631 ntohs(param.p->length), gfp);
2632 if (!asoc->peer.peer_random) {
2633 retval = 0;
2634 break;
2635 }
2636 break;
2637
2638 case SCTP_PARAM_HMAC_ALGO:
2639 if (!net->sctp.auth_enable)
2640 goto fall_through;
2641
2642 /* Save peer's HMAC list */
2643 asoc->peer.peer_hmacs = kmemdup(param.p,
2644 ntohs(param.p->length), gfp);
2645 if (!asoc->peer.peer_hmacs) {
2646 retval = 0;
2647 break;
2648 }
2649
2650 /* Set the default HMAC the peer requested*/
2651 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo);
2652 break;
2653
2654 case SCTP_PARAM_CHUNKS:
2655 if (!net->sctp.auth_enable)
2656 goto fall_through;
2657
2658 asoc->peer.peer_chunks = kmemdup(param.p,
2659 ntohs(param.p->length), gfp);
2660 if (!asoc->peer.peer_chunks)
2661 retval = 0;
2662 break;
2663 fall_through:
2664 default:
2665 /* Any unrecognized parameters should have been caught
2666 * and handled by sctp_verify_param() which should be
2667 * called prior to this routine. Simply log the error
2668 * here.
2669 */
2670 SCTP_DEBUG_PRINTK("Ignoring param: %d for association %p.\n",
2671 ntohs(param.p->type), asoc);
2672 break;
2673 }
2674
2675 return retval;
2676 }
2677
2678 /* Select a new verification tag. */
2679 __u32 sctp_generate_tag(const struct sctp_endpoint *ep)
2680 {
2681 /* I believe that this random number generator complies with RFC1750.
2682 * A tag of 0 is reserved for special cases (e.g. INIT).
2683 */
2684 __u32 x;
2685
2686 do {
2687 get_random_bytes(&x, sizeof(__u32));
2688 } while (x == 0);
2689
2690 return x;
2691 }
2692
2693 /* Select an initial TSN to send during startup. */
2694 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep)
2695 {
2696 __u32 retval;
2697
2698 get_random_bytes(&retval, sizeof(__u32));
2699 return retval;
2700 }
2701
2702 /*
2703 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF)
2704 * 0 1 2 3
2705 * 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
2706 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2707 * | Type = 0xC1 | Chunk Flags | Chunk Length |
2708 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2709 * | Serial Number |
2710 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2711 * | Address Parameter |
2712 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2713 * | ASCONF Parameter #1 |
2714 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2715 * \ \
2716 * / .... /
2717 * \ \
2718 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2719 * | ASCONF Parameter #N |
2720 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2721 *
2722 * Address Parameter and other parameter will not be wrapped in this function
2723 */
2724 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc,
2725 union sctp_addr *addr,
2726 int vparam_len)
2727 {
2728 sctp_addiphdr_t asconf;
2729 struct sctp_chunk *retval;
2730 int length = sizeof(asconf) + vparam_len;
2731 union sctp_addr_param addrparam;
2732 int addrlen;
2733 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
2734
2735 addrlen = af->to_addr_param(addr, &addrparam);
2736 if (!addrlen)
2737 return NULL;
2738 length += addrlen;
2739
2740 /* Create the chunk. */
2741 retval = sctp_make_chunk(asoc, SCTP_CID_ASCONF, 0, length);
2742 if (!retval)
2743 return NULL;
2744
2745 asconf.serial = htonl(asoc->addip_serial++);
2746
2747 retval->subh.addip_hdr =
2748 sctp_addto_chunk(retval, sizeof(asconf), &asconf);
2749 retval->param_hdr.v =
2750 sctp_addto_chunk(retval, addrlen, &addrparam);
2751
2752 return retval;
2753 }
2754
2755 /* ADDIP
2756 * 3.2.1 Add IP Address
2757 * 0 1 2 3
2758 * 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
2759 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2760 * | Type = 0xC001 | Length = Variable |
2761 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2762 * | ASCONF-Request Correlation ID |
2763 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2764 * | Address Parameter |
2765 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2766 *
2767 * 3.2.2 Delete IP Address
2768 * 0 1 2 3
2769 * 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
2770 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2771 * | Type = 0xC002 | Length = Variable |
2772 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2773 * | ASCONF-Request Correlation ID |
2774 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2775 * | Address Parameter |
2776 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2777 *
2778 */
2779 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc,
2780 union sctp_addr *laddr,
2781 struct sockaddr *addrs,
2782 int addrcnt,
2783 __be16 flags)
2784 {
2785 sctp_addip_param_t param;
2786 struct sctp_chunk *retval;
2787 union sctp_addr_param addr_param;
2788 union sctp_addr *addr;
2789 void *addr_buf;
2790 struct sctp_af *af;
2791 int paramlen = sizeof(param);
2792 int addr_param_len = 0;
2793 int totallen = 0;
2794 int i;
2795 int del_pickup = 0;
2796
2797 /* Get total length of all the address parameters. */
2798 addr_buf = addrs;
2799 for (i = 0; i < addrcnt; i++) {
2800 addr = addr_buf;
2801 af = sctp_get_af_specific(addr->v4.sin_family);
2802 addr_param_len = af->to_addr_param(addr, &addr_param);
2803
2804 totallen += paramlen;
2805 totallen += addr_param_len;
2806
2807 addr_buf += af->sockaddr_len;
2808 if (asoc->asconf_addr_del_pending && !del_pickup) {
2809 /* reuse the parameter length from the same scope one */
2810 totallen += paramlen;
2811 totallen += addr_param_len;
2812 del_pickup = 1;
2813 SCTP_DEBUG_PRINTK("mkasconf_update_ip: picked same-scope del_pending addr, totallen for all addresses is %d\n", totallen);
2814 }
2815 }
2816
2817 /* Create an asconf chunk with the required length. */
2818 retval = sctp_make_asconf(asoc, laddr, totallen);
2819 if (!retval)
2820 return NULL;
2821
2822 /* Add the address parameters to the asconf chunk. */
2823 addr_buf = addrs;
2824 for (i = 0; i < addrcnt; i++) {
2825 addr = addr_buf;
2826 af = sctp_get_af_specific(addr->v4.sin_family);
2827 addr_param_len = af->to_addr_param(addr, &addr_param);
2828 param.param_hdr.type = flags;
2829 param.param_hdr.length = htons(paramlen + addr_param_len);
2830 param.crr_id = i;
2831
2832 sctp_addto_chunk(retval, paramlen, &param);
2833 sctp_addto_chunk(retval, addr_param_len, &addr_param);
2834
2835 addr_buf += af->sockaddr_len;
2836 }
2837 if (flags == SCTP_PARAM_ADD_IP && del_pickup) {
2838 addr = asoc->asconf_addr_del_pending;
2839 af = sctp_get_af_specific(addr->v4.sin_family);
2840 addr_param_len = af->to_addr_param(addr, &addr_param);
2841 param.param_hdr.type = SCTP_PARAM_DEL_IP;
2842 param.param_hdr.length = htons(paramlen + addr_param_len);
2843 param.crr_id = i;
2844
2845 sctp_addto_chunk(retval, paramlen, &param);
2846 sctp_addto_chunk(retval, addr_param_len, &addr_param);
2847 }
2848 return retval;
2849 }
2850
2851 /* ADDIP
2852 * 3.2.4 Set Primary IP Address
2853 * 0 1 2 3
2854 * 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
2855 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2856 * | Type =0xC004 | Length = Variable |
2857 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2858 * | ASCONF-Request Correlation ID |
2859 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2860 * | Address Parameter |
2861 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2862 *
2863 * Create an ASCONF chunk with Set Primary IP address parameter.
2864 */
2865 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
2866 union sctp_addr *addr)
2867 {
2868 sctp_addip_param_t param;
2869 struct sctp_chunk *retval;
2870 int len = sizeof(param);
2871 union sctp_addr_param addrparam;
2872 int addrlen;
2873 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
2874
2875 addrlen = af->to_addr_param(addr, &addrparam);
2876 if (!addrlen)
2877 return NULL;
2878 len += addrlen;
2879
2880 /* Create the chunk and make asconf header. */
2881 retval = sctp_make_asconf(asoc, addr, len);
2882 if (!retval)
2883 return NULL;
2884
2885 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY;
2886 param.param_hdr.length = htons(len);
2887 param.crr_id = 0;
2888
2889 sctp_addto_chunk(retval, sizeof(param), &param);
2890 sctp_addto_chunk(retval, addrlen, &addrparam);
2891
2892 return retval;
2893 }
2894
2895 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK)
2896 * 0 1 2 3
2897 * 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
2898 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2899 * | Type = 0x80 | Chunk Flags | Chunk Length |
2900 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2901 * | Serial Number |
2902 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2903 * | ASCONF Parameter Response#1 |
2904 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2905 * \ \
2906 * / .... /
2907 * \ \
2908 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2909 * | ASCONF Parameter Response#N |
2910 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2911 *
2912 * Create an ASCONF_ACK chunk with enough space for the parameter responses.
2913 */
2914 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc,
2915 __u32 serial, int vparam_len)
2916 {
2917 sctp_addiphdr_t asconf;
2918 struct sctp_chunk *retval;
2919 int length = sizeof(asconf) + vparam_len;
2920
2921 /* Create the chunk. */
2922 retval = sctp_make_chunk(asoc, SCTP_CID_ASCONF_ACK, 0, length);
2923 if (!retval)
2924 return NULL;
2925
2926 asconf.serial = htonl(serial);
2927
2928 retval->subh.addip_hdr =
2929 sctp_addto_chunk(retval, sizeof(asconf), &asconf);
2930
2931 return retval;
2932 }
2933
2934 /* Add response parameters to an ASCONF_ACK chunk. */
2935 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id,
2936 __be16 err_code, sctp_addip_param_t *asconf_param)
2937 {
2938 sctp_addip_param_t ack_param;
2939 sctp_errhdr_t err_param;
2940 int asconf_param_len = 0;
2941 int err_param_len = 0;
2942 __be16 response_type;
2943
2944 if (SCTP_ERROR_NO_ERROR == err_code) {
2945 response_type = SCTP_PARAM_SUCCESS_REPORT;
2946 } else {
2947 response_type = SCTP_PARAM_ERR_CAUSE;
2948 err_param_len = sizeof(err_param);
2949 if (asconf_param)
2950 asconf_param_len =
2951 ntohs(asconf_param->param_hdr.length);
2952 }
2953
2954 /* Add Success Indication or Error Cause Indication parameter. */
2955 ack_param.param_hdr.type = response_type;
2956 ack_param.param_hdr.length = htons(sizeof(ack_param) +
2957 err_param_len +
2958 asconf_param_len);
2959 ack_param.crr_id = crr_id;
2960 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param);
2961
2962 if (SCTP_ERROR_NO_ERROR == err_code)
2963 return;
2964
2965 /* Add Error Cause parameter. */
2966 err_param.cause = err_code;
2967 err_param.length = htons(err_param_len + asconf_param_len);
2968 sctp_addto_chunk(chunk, err_param_len, &err_param);
2969
2970 /* Add the failed TLV copied from ASCONF chunk. */
2971 if (asconf_param)
2972 sctp_addto_chunk(chunk, asconf_param_len, asconf_param);
2973 }
2974
2975 /* Process a asconf parameter. */
2976 static __be16 sctp_process_asconf_param(struct sctp_association *asoc,
2977 struct sctp_chunk *asconf,
2978 sctp_addip_param_t *asconf_param)
2979 {
2980 struct sctp_transport *peer;
2981 struct sctp_af *af;
2982 union sctp_addr addr;
2983 union sctp_addr_param *addr_param;
2984
2985 addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t);
2986
2987 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP &&
2988 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP &&
2989 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY)
2990 return SCTP_ERROR_UNKNOWN_PARAM;
2991
2992 switch (addr_param->p.type) {
2993 case SCTP_PARAM_IPV6_ADDRESS:
2994 if (!asoc->peer.ipv6_address)
2995 return SCTP_ERROR_DNS_FAILED;
2996 break;
2997 case SCTP_PARAM_IPV4_ADDRESS:
2998 if (!asoc->peer.ipv4_address)
2999 return SCTP_ERROR_DNS_FAILED;
3000 break;
3001 default:
3002 return SCTP_ERROR_DNS_FAILED;
3003 }
3004
3005 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
3006 if (unlikely(!af))
3007 return SCTP_ERROR_DNS_FAILED;
3008
3009 af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0);
3010
3011 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast
3012 * or multicast address.
3013 * (note: wildcard is permitted and requires special handling so
3014 * make sure we check for that)
3015 */
3016 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb))
3017 return SCTP_ERROR_DNS_FAILED;
3018
3019 switch (asconf_param->param_hdr.type) {
3020 case SCTP_PARAM_ADD_IP:
3021 /* Section 4.2.1:
3022 * If the address 0.0.0.0 or ::0 is provided, the source
3023 * address of the packet MUST be added.
3024 */
3025 if (af->is_any(&addr))
3026 memcpy(&addr, &asconf->source, sizeof(addr));
3027
3028 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address
3029 * request and does not have the local resources to add this
3030 * new address to the association, it MUST return an Error
3031 * Cause TLV set to the new error code 'Operation Refused
3032 * Due to Resource Shortage'.
3033 */
3034
3035 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED);
3036 if (!peer)
3037 return SCTP_ERROR_RSRC_LOW;
3038
3039 /* Start the heartbeat timer. */
3040 if (!mod_timer(&peer->hb_timer, sctp_transport_timeout(peer)))
3041 sctp_transport_hold(peer);
3042 asoc->new_transport = peer;
3043 break;
3044 case SCTP_PARAM_DEL_IP:
3045 /* ADDIP 4.3 D7) If a request is received to delete the
3046 * last remaining IP address of a peer endpoint, the receiver
3047 * MUST send an Error Cause TLV with the error cause set to the
3048 * new error code 'Request to Delete Last Remaining IP Address'.
3049 */
3050 if (asoc->peer.transport_count == 1)
3051 return SCTP_ERROR_DEL_LAST_IP;
3052
3053 /* ADDIP 4.3 D8) If a request is received to delete an IP
3054 * address which is also the source address of the IP packet
3055 * which contained the ASCONF chunk, the receiver MUST reject
3056 * this request. To reject the request the receiver MUST send
3057 * an Error Cause TLV set to the new error code 'Request to
3058 * Delete Source IP Address'
3059 */
3060 if (sctp_cmp_addr_exact(&asconf->source, &addr))
3061 return SCTP_ERROR_DEL_SRC_IP;
3062
3063 /* Section 4.2.2
3064 * If the address 0.0.0.0 or ::0 is provided, all
3065 * addresses of the peer except the source address of the
3066 * packet MUST be deleted.
3067 */
3068 if (af->is_any(&addr)) {
3069 sctp_assoc_set_primary(asoc, asconf->transport);
3070 sctp_assoc_del_nonprimary_peers(asoc,
3071 asconf->transport);
3072 } else
3073 sctp_assoc_del_peer(asoc, &addr);
3074 break;
3075 case SCTP_PARAM_SET_PRIMARY:
3076 /* ADDIP Section 4.2.4
3077 * If the address 0.0.0.0 or ::0 is provided, the receiver
3078 * MAY mark the source address of the packet as its
3079 * primary.
3080 */
3081 if (af->is_any(&addr))
3082 memcpy(&addr.v4, sctp_source(asconf), sizeof(addr));
3083
3084 peer = sctp_assoc_lookup_paddr(asoc, &addr);
3085 if (!peer)
3086 return SCTP_ERROR_DNS_FAILED;
3087
3088 sctp_assoc_set_primary(asoc, peer);
3089 break;
3090 }
3091
3092 return SCTP_ERROR_NO_ERROR;
3093 }
3094
3095 /* Verify the ASCONF packet before we process it. */
3096 int sctp_verify_asconf(const struct sctp_association *asoc,
3097 struct sctp_paramhdr *param_hdr, void *chunk_end,
3098 struct sctp_paramhdr **errp) {
3099 sctp_addip_param_t *asconf_param;
3100 union sctp_params param;
3101 int length, plen;
3102
3103 param.v = (sctp_paramhdr_t *) param_hdr;
3104 while (param.v <= chunk_end - sizeof(sctp_paramhdr_t)) {
3105 length = ntohs(param.p->length);
3106 *errp = param.p;
3107
3108 if (param.v > chunk_end - length ||
3109 length < sizeof(sctp_paramhdr_t))
3110 return 0;
3111
3112 switch (param.p->type) {
3113 case SCTP_PARAM_ADD_IP:
3114 case SCTP_PARAM_DEL_IP:
3115 case SCTP_PARAM_SET_PRIMARY:
3116 asconf_param = (sctp_addip_param_t *)param.v;
3117 plen = ntohs(asconf_param->param_hdr.length);
3118 if (plen < sizeof(sctp_addip_param_t) +
3119 sizeof(sctp_paramhdr_t))
3120 return 0;
3121 break;
3122 case SCTP_PARAM_SUCCESS_REPORT:
3123 case SCTP_PARAM_ADAPTATION_LAYER_IND:
3124 if (length != sizeof(sctp_addip_param_t))
3125 return 0;
3126
3127 break;
3128 default:
3129 break;
3130 }
3131
3132 param.v += WORD_ROUND(length);
3133 }
3134
3135 if (param.v != chunk_end)
3136 return 0;
3137
3138 return 1;
3139 }
3140
3141 /* Process an incoming ASCONF chunk with the next expected serial no. and
3142 * return an ASCONF_ACK chunk to be sent in response.
3143 */
3144 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
3145 struct sctp_chunk *asconf)
3146 {
3147 sctp_addiphdr_t *hdr;
3148 union sctp_addr_param *addr_param;
3149 sctp_addip_param_t *asconf_param;
3150 struct sctp_chunk *asconf_ack;
3151
3152 __be16 err_code;
3153 int length = 0;
3154 int chunk_len;
3155 __u32 serial;
3156 int all_param_pass = 1;
3157
3158 chunk_len = ntohs(asconf->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
3159 hdr = (sctp_addiphdr_t *)asconf->skb->data;
3160 serial = ntohl(hdr->serial);
3161
3162 /* Skip the addiphdr and store a pointer to address parameter. */
3163 length = sizeof(sctp_addiphdr_t);
3164 addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
3165 chunk_len -= length;
3166
3167 /* Skip the address parameter and store a pointer to the first
3168 * asconf parameter.
3169 */
3170 length = ntohs(addr_param->p.length);
3171 asconf_param = (void *)addr_param + length;
3172 chunk_len -= length;
3173
3174 /* create an ASCONF_ACK chunk.
3175 * Based on the definitions of parameters, we know that the size of
3176 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF
3177 * parameters.
3178 */
3179 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4);
3180 if (!asconf_ack)
3181 goto done;
3182
3183 /* Process the TLVs contained within the ASCONF chunk. */
3184 while (chunk_len > 0) {
3185 err_code = sctp_process_asconf_param(asoc, asconf,
3186 asconf_param);
3187 /* ADDIP 4.1 A7)
3188 * If an error response is received for a TLV parameter,
3189 * all TLVs with no response before the failed TLV are
3190 * considered successful if not reported. All TLVs after
3191 * the failed response are considered unsuccessful unless
3192 * a specific success indication is present for the parameter.
3193 */
3194 if (SCTP_ERROR_NO_ERROR != err_code)
3195 all_param_pass = 0;
3196
3197 if (!all_param_pass)
3198 sctp_add_asconf_response(asconf_ack,
3199 asconf_param->crr_id, err_code,
3200 asconf_param);
3201
3202 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add
3203 * an IP address sends an 'Out of Resource' in its response, it
3204 * MUST also fail any subsequent add or delete requests bundled
3205 * in the ASCONF.
3206 */
3207 if (SCTP_ERROR_RSRC_LOW == err_code)
3208 goto done;
3209
3210 /* Move to the next ASCONF param. */
3211 length = ntohs(asconf_param->param_hdr.length);
3212 asconf_param = (void *)asconf_param + length;
3213 chunk_len -= length;
3214 }
3215
3216 done:
3217 asoc->peer.addip_serial++;
3218
3219 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc
3220 * after freeing the reference to old asconf ack if any.
3221 */
3222 if (asconf_ack) {
3223 sctp_chunk_hold(asconf_ack);
3224 list_add_tail(&asconf_ack->transmitted_list,
3225 &asoc->asconf_ack_list);
3226 }
3227
3228 return asconf_ack;
3229 }
3230
3231 /* Process a asconf parameter that is successfully acked. */
3232 static void sctp_asconf_param_success(struct sctp_association *asoc,
3233 sctp_addip_param_t *asconf_param)
3234 {
3235 struct sctp_af *af;
3236 union sctp_addr addr;
3237 struct sctp_bind_addr *bp = &asoc->base.bind_addr;
3238 union sctp_addr_param *addr_param;
3239 struct sctp_transport *transport;
3240 struct sctp_sockaddr_entry *saddr;
3241
3242 addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t);
3243
3244 /* We have checked the packet before, so we do not check again. */
3245 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
3246 af->from_addr_param(&addr, addr_param, htons(bp->port), 0);
3247
3248 switch (asconf_param->param_hdr.type) {
3249 case SCTP_PARAM_ADD_IP:
3250 /* This is always done in BH context with a socket lock
3251 * held, so the list can not change.
3252 */
3253 local_bh_disable();
3254 list_for_each_entry(saddr, &bp->address_list, list) {
3255 if (sctp_cmp_addr_exact(&saddr->a, &addr))
3256 saddr->state = SCTP_ADDR_SRC;
3257 }
3258 local_bh_enable();
3259 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
3260 transports) {
3261 dst_release(transport->dst);
3262 transport->dst = NULL;
3263 }
3264 break;
3265 case SCTP_PARAM_DEL_IP:
3266 local_bh_disable();
3267 sctp_del_bind_addr(bp, &addr);
3268 if (asoc->asconf_addr_del_pending != NULL &&
3269 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) {
3270 kfree(asoc->asconf_addr_del_pending);
3271 asoc->asconf_addr_del_pending = NULL;
3272 }
3273 local_bh_enable();
3274 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
3275 transports) {
3276 dst_release(transport->dst);
3277 transport->dst = NULL;
3278 }
3279 break;
3280 default:
3281 break;
3282 }
3283 }
3284
3285 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk
3286 * for the given asconf parameter. If there is no response for this parameter,
3287 * return the error code based on the third argument 'no_err'.
3288 * ADDIP 4.1
3289 * A7) If an error response is received for a TLV parameter, all TLVs with no
3290 * response before the failed TLV are considered successful if not reported.
3291 * All TLVs after the failed response are considered unsuccessful unless a
3292 * specific success indication is present for the parameter.
3293 */
3294 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack,
3295 sctp_addip_param_t *asconf_param,
3296 int no_err)
3297 {
3298 sctp_addip_param_t *asconf_ack_param;
3299 sctp_errhdr_t *err_param;
3300 int length;
3301 int asconf_ack_len;
3302 __be16 err_code;
3303
3304 if (no_err)
3305 err_code = SCTP_ERROR_NO_ERROR;
3306 else
3307 err_code = SCTP_ERROR_REQ_REFUSED;
3308
3309 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) -
3310 sizeof(sctp_chunkhdr_t);
3311
3312 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to
3313 * the first asconf_ack parameter.
3314 */
3315 length = sizeof(sctp_addiphdr_t);
3316 asconf_ack_param = (sctp_addip_param_t *)(asconf_ack->skb->data +
3317 length);
3318 asconf_ack_len -= length;
3319
3320 while (asconf_ack_len > 0) {
3321 if (asconf_ack_param->crr_id == asconf_param->crr_id) {
3322 switch(asconf_ack_param->param_hdr.type) {
3323 case SCTP_PARAM_SUCCESS_REPORT:
3324 return SCTP_ERROR_NO_ERROR;
3325 case SCTP_PARAM_ERR_CAUSE:
3326 length = sizeof(sctp_addip_param_t);
3327 err_param = (void *)asconf_ack_param + length;
3328 asconf_ack_len -= length;
3329 if (asconf_ack_len > 0)
3330 return err_param->cause;
3331 else
3332 return SCTP_ERROR_INV_PARAM;
3333 break;
3334 default:
3335 return SCTP_ERROR_INV_PARAM;
3336 }
3337 }
3338
3339 length = ntohs(asconf_ack_param->param_hdr.length);
3340 asconf_ack_param = (void *)asconf_ack_param + length;
3341 asconf_ack_len -= length;
3342 }
3343
3344 return err_code;
3345 }
3346
3347 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */
3348 int sctp_process_asconf_ack(struct sctp_association *asoc,
3349 struct sctp_chunk *asconf_ack)
3350 {
3351 struct sctp_chunk *asconf = asoc->addip_last_asconf;
3352 union sctp_addr_param *addr_param;
3353 sctp_addip_param_t *asconf_param;
3354 int length = 0;
3355 int asconf_len = asconf->skb->len;
3356 int all_param_pass = 0;
3357 int no_err = 1;
3358 int retval = 0;
3359 __be16 err_code = SCTP_ERROR_NO_ERROR;
3360
3361 /* Skip the chunkhdr and addiphdr from the last asconf sent and store
3362 * a pointer to address parameter.
3363 */
3364 length = sizeof(sctp_addip_chunk_t);
3365 addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
3366 asconf_len -= length;
3367
3368 /* Skip the address parameter in the last asconf sent and store a
3369 * pointer to the first asconf parameter.
3370 */
3371 length = ntohs(addr_param->p.length);
3372 asconf_param = (void *)addr_param + length;
3373 asconf_len -= length;
3374
3375 /* ADDIP 4.1
3376 * A8) If there is no response(s) to specific TLV parameter(s), and no
3377 * failures are indicated, then all request(s) are considered
3378 * successful.
3379 */
3380 if (asconf_ack->skb->len == sizeof(sctp_addiphdr_t))
3381 all_param_pass = 1;
3382
3383 /* Process the TLVs contained in the last sent ASCONF chunk. */
3384 while (asconf_len > 0) {
3385 if (all_param_pass)
3386 err_code = SCTP_ERROR_NO_ERROR;
3387 else {
3388 err_code = sctp_get_asconf_response(asconf_ack,
3389 asconf_param,
3390 no_err);
3391 if (no_err && (SCTP_ERROR_NO_ERROR != err_code))
3392 no_err = 0;
3393 }
3394
3395 switch (err_code) {
3396 case SCTP_ERROR_NO_ERROR:
3397 sctp_asconf_param_success(asoc, asconf_param);
3398 break;
3399
3400 case SCTP_ERROR_RSRC_LOW:
3401 retval = 1;
3402 break;
3403
3404 case SCTP_ERROR_UNKNOWN_PARAM:
3405 /* Disable sending this type of asconf parameter in
3406 * future.
3407 */
3408 asoc->peer.addip_disabled_mask |=
3409 asconf_param->param_hdr.type;
3410 break;
3411
3412 case SCTP_ERROR_REQ_REFUSED:
3413 case SCTP_ERROR_DEL_LAST_IP:
3414 case SCTP_ERROR_DEL_SRC_IP:
3415 default:
3416 break;
3417 }
3418
3419 /* Skip the processed asconf parameter and move to the next
3420 * one.
3421 */
3422 length = ntohs(asconf_param->param_hdr.length);
3423 asconf_param = (void *)asconf_param + length;
3424 asconf_len -= length;
3425 }
3426
3427 if (no_err && asoc->src_out_of_asoc_ok) {
3428 asoc->src_out_of_asoc_ok = 0;
3429 sctp_transport_immediate_rtx(asoc->peer.primary_path);
3430 }
3431
3432 /* Free the cached last sent asconf chunk. */
3433 list_del_init(&asconf->transmitted_list);
3434 sctp_chunk_free(asconf);
3435 asoc->addip_last_asconf = NULL;
3436
3437 return retval;
3438 }
3439
3440 /* Make a FWD TSN chunk. */
3441 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
3442 __u32 new_cum_tsn, size_t nstreams,
3443 struct sctp_fwdtsn_skip *skiplist)
3444 {
3445 struct sctp_chunk *retval = NULL;
3446 struct sctp_fwdtsn_hdr ftsn_hdr;
3447 struct sctp_fwdtsn_skip skip;
3448 size_t hint;
3449 int i;
3450
3451 hint = (nstreams + 1) * sizeof(__u32);
3452
3453 retval = sctp_make_chunk(asoc, SCTP_CID_FWD_TSN, 0, hint);
3454
3455 if (!retval)
3456 return NULL;
3457
3458 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn);
3459 retval->subh.fwdtsn_hdr =
3460 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr);
3461
3462 for (i = 0; i < nstreams; i++) {
3463 skip.stream = skiplist[i].stream;
3464 skip.ssn = skiplist[i].ssn;
3465 sctp_addto_chunk(retval, sizeof(skip), &skip);
3466 }
3467
3468 return retval;
3469 }
Linus' kernel tree