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sctp: fix copying more bytes than expected in sctp_add_bind_addr
[linux/fpc-iii.git] / net / sctp / sm_make_chunk.c
blob7fe971e30ad6b60e21bfa2986f1c9909a0dabc21
1 /* SCTP kernel implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999-2000 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 * Copyright (c) 2001-2002 Intel Corp.
6 *
7 * This file is part of the SCTP kernel implementation
8 *
9 * These functions work with the state functions in sctp_sm_statefuns.c
10 * to implement the state operations. These functions implement the
11 * steps which require modifying existing data structures.
12 *
13 * This SCTP implementation is free software;
14 * you can redistribute it and/or modify it under the terms of
15 * the GNU General Public License as published by
16 * the Free Software Foundation; either version 2, or (at your option)
17 * any later version.
18 *
19 * This SCTP implementation is distributed in the hope that it
20 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
21 * ************************
22 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
23 * See the GNU General Public License for more details.
24 *
25 * You should have received a copy of the GNU General Public License
26 * along with GNU CC; see the file COPYING. If not, see
27 * <http://www.gnu.org/licenses/>.
28 *
29 * Please send any bug reports or fixes you make to the
30 * email address(es):
31 * lksctp developers <linux-sctp@vger.kernel.org>
32 *
33 * Written or modified by:
34 * La Monte H.P. Yarroll <piggy@acm.org>
35 * Karl Knutson <karl@athena.chicago.il.us>
36 * C. Robin <chris@hundredacre.ac.uk>
37 * Jon Grimm <jgrimm@us.ibm.com>
38 * Xingang Guo <xingang.guo@intel.com>
39 * Dajiang Zhang <dajiang.zhang@nokia.com>
40 * Sridhar Samudrala <sri@us.ibm.com>
41 * Daisy Chang <daisyc@us.ibm.com>
42 * Ardelle Fan <ardelle.fan@intel.com>
43 * Kevin Gao <kevin.gao@intel.com>
44 */
45
46 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
47
48 #include <linux/types.h>
49 #include <linux/kernel.h>
50 #include <linux/ip.h>
51 #include <linux/ipv6.h>
52 #include <linux/net.h>
53 #include <linux/inet.h>
54 #include <linux/scatterlist.h>
55 #include <linux/crypto.h>
56 #include <linux/slab.h>
57 #include <net/sock.h>
58
59 #include <linux/skbuff.h>
60 #include <linux/random.h> /* for get_random_bytes */
61 #include <net/sctp/sctp.h>
62 #include <net/sctp/sm.h>
63
64 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc,
65 __u8 type, __u8 flags, int paylen);
66 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc,
67 __u8 flags, int paylen);
68 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc,
69 __u8 type, __u8 flags, int paylen);
70 static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep,
71 const struct sctp_association *asoc,
72 const struct sctp_chunk *init_chunk,
73 int *cookie_len,
74 const __u8 *raw_addrs, int addrs_len);
75 static int sctp_process_param(struct sctp_association *asoc,
76 union sctp_params param,
77 const union sctp_addr *peer_addr,
78 gfp_t gfp);
79 static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
80 const void *data);
81 static void *sctp_addto_chunk_fixed(struct sctp_chunk *, int len,
82 const void *data);
83
84 /* Control chunk destructor */
85 static void sctp_control_release_owner(struct sk_buff *skb)
86 {
87 /*TODO: do memory release */
88 }
89
90 static void sctp_control_set_owner_w(struct sctp_chunk *chunk)
91 {
92 struct sctp_association *asoc = chunk->asoc;
93 struct sk_buff *skb = chunk->skb;
94
95 /* TODO: properly account for control chunks.
96 * To do it right we'll need:
97 * 1) endpoint if association isn't known.
98 * 2) proper memory accounting.
99 *
100 * For now don't do anything for now.
101 */
102 skb->sk = asoc ? asoc->base.sk : NULL;
103 skb->destructor = sctp_control_release_owner;
104 }
105
106 /* What was the inbound interface for this chunk? */
107 int sctp_chunk_iif(const struct sctp_chunk *chunk)
108 {
109 struct sctp_af *af;
110 int iif = 0;
111
112 af = sctp_get_af_specific(ipver2af(ip_hdr(chunk->skb)->version));
113 if (af)
114 iif = af->skb_iif(chunk->skb);
115
116 return iif;
117 }
118
119 /* RFC 2960 3.3.2 Initiation (INIT) (1)
120 *
121 * Note 2: The ECN capable field is reserved for future use of
122 * Explicit Congestion Notification.
123 */
124 static const struct sctp_paramhdr ecap_param = {
125 SCTP_PARAM_ECN_CAPABLE,
126 cpu_to_be16(sizeof(struct sctp_paramhdr)),
127 };
128 static const struct sctp_paramhdr prsctp_param = {
129 SCTP_PARAM_FWD_TSN_SUPPORT,
130 cpu_to_be16(sizeof(struct sctp_paramhdr)),
131 };
132
133 /* A helper to initialize an op error inside a
134 * provided chunk, as most cause codes will be embedded inside an
135 * abort chunk.
136 */
137 void sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code,
138 size_t paylen)
139 {
140 sctp_errhdr_t err;
141 __u16 len;
142
143 /* Cause code constants are now defined in network order. */
144 err.cause = cause_code;
145 len = sizeof(sctp_errhdr_t) + paylen;
146 err.length = htons(len);
147 chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(sctp_errhdr_t), &err);
148 }
149
150 /* A helper to initialize an op error inside a
151 * provided chunk, as most cause codes will be embedded inside an
152 * abort chunk. Differs from sctp_init_cause in that it won't oops
153 * if there isn't enough space in the op error chunk
154 */
155 static int sctp_init_cause_fixed(struct sctp_chunk *chunk, __be16 cause_code,
156 size_t paylen)
157 {
158 sctp_errhdr_t err;
159 __u16 len;
160
161 /* Cause code constants are now defined in network order. */
162 err.cause = cause_code;
163 len = sizeof(sctp_errhdr_t) + paylen;
164 err.length = htons(len);
165
166 if (skb_tailroom(chunk->skb) < len)
167 return -ENOSPC;
168 chunk->subh.err_hdr = sctp_addto_chunk_fixed(chunk,
169 sizeof(sctp_errhdr_t),
170 &err);
171 return 0;
172 }
173 /* 3.3.2 Initiation (INIT) (1)
174 *
175 * This chunk is used to initiate a SCTP association between two
176 * endpoints. The format of the INIT chunk is shown below:
177 *
178 * 0 1 2 3
179 * 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
180 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
181 * | Type = 1 | Chunk Flags | Chunk Length |
182 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
183 * | Initiate Tag |
184 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
185 * | Advertised Receiver Window Credit (a_rwnd) |
186 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
187 * | Number of Outbound Streams | Number of Inbound Streams |
188 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
189 * | Initial TSN |
190 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
191 * \ \
192 * / Optional/Variable-Length Parameters /
193 * \ \
194 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
195 *
196 *
197 * The INIT chunk contains the following parameters. Unless otherwise
198 * noted, each parameter MUST only be included once in the INIT chunk.
199 *
200 * Fixed Parameters Status
201 * ----------------------------------------------
202 * Initiate Tag Mandatory
203 * Advertised Receiver Window Credit Mandatory
204 * Number of Outbound Streams Mandatory
205 * Number of Inbound Streams Mandatory
206 * Initial TSN Mandatory
207 *
208 * Variable Parameters Status Type Value
209 * -------------------------------------------------------------
210 * IPv4 Address (Note 1) Optional 5
211 * IPv6 Address (Note 1) Optional 6
212 * Cookie Preservative Optional 9
213 * Reserved for ECN Capable (Note 2) Optional 32768 (0x8000)
214 * Host Name Address (Note 3) Optional 11
215 * Supported Address Types (Note 4) Optional 12
216 */
217 struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc,
218 const struct sctp_bind_addr *bp,
219 gfp_t gfp, int vparam_len)
220 {
221 struct net *net = sock_net(asoc->base.sk);
222 struct sctp_endpoint *ep = asoc->ep;
223 sctp_inithdr_t init;
224 union sctp_params addrs;
225 size_t chunksize;
226 struct sctp_chunk *retval = NULL;
227 int num_types, addrs_len = 0;
228 struct sctp_sock *sp;
229 sctp_supported_addrs_param_t sat;
230 __be16 types[2];
231 sctp_adaptation_ind_param_t aiparam;
232 sctp_supported_ext_param_t ext_param;
233 int num_ext = 0;
234 __u8 extensions[3];
235 sctp_paramhdr_t *auth_chunks = NULL,
236 *auth_hmacs = NULL;
237
238 /* RFC 2960 3.3.2 Initiation (INIT) (1)
239 *
240 * Note 1: The INIT chunks can contain multiple addresses that
241 * can be IPv4 and/or IPv6 in any combination.
242 */
243 retval = NULL;
244
245 /* Convert the provided bind address list to raw format. */
246 addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp);
247
248 init.init_tag = htonl(asoc->c.my_vtag);
249 init.a_rwnd = htonl(asoc->rwnd);
250 init.num_outbound_streams = htons(asoc->c.sinit_num_ostreams);
251 init.num_inbound_streams = htons(asoc->c.sinit_max_instreams);
252 init.initial_tsn = htonl(asoc->c.initial_tsn);
253
254 /* How many address types are needed? */
255 sp = sctp_sk(asoc->base.sk);
256 num_types = sp->pf->supported_addrs(sp, types);
257
258 chunksize = sizeof(init) + addrs_len;
259 chunksize += WORD_ROUND(SCTP_SAT_LEN(num_types));
260 chunksize += sizeof(ecap_param);
261
262 if (net->sctp.prsctp_enable)
263 chunksize += sizeof(prsctp_param);
264
265 /* ADDIP: Section 4.2.7:
266 * An implementation supporting this extension [ADDIP] MUST list
267 * the ASCONF,the ASCONF-ACK, and the AUTH chunks in its INIT and
268 * INIT-ACK parameters.
269 */
270 if (net->sctp.addip_enable) {
271 extensions[num_ext] = SCTP_CID_ASCONF;
272 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
273 num_ext += 2;
274 }
275
276 if (sp->adaptation_ind)
277 chunksize += sizeof(aiparam);
278
279 chunksize += vparam_len;
280
281 /* Account for AUTH related parameters */
282 if (ep->auth_enable) {
283 /* Add random parameter length*/
284 chunksize += sizeof(asoc->c.auth_random);
285
286 /* Add HMACS parameter length if any were defined */
287 auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs;
288 if (auth_hmacs->length)
289 chunksize += WORD_ROUND(ntohs(auth_hmacs->length));
290 else
291 auth_hmacs = NULL;
292
293 /* Add CHUNKS parameter length */
294 auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks;
295 if (auth_chunks->length)
296 chunksize += WORD_ROUND(ntohs(auth_chunks->length));
297 else
298 auth_chunks = NULL;
299
300 extensions[num_ext] = SCTP_CID_AUTH;
301 num_ext += 1;
302 }
303
304 /* If we have any extensions to report, account for that */
305 if (num_ext)
306 chunksize += WORD_ROUND(sizeof(sctp_supported_ext_param_t) +
307 num_ext);
308
309 /* RFC 2960 3.3.2 Initiation (INIT) (1)
310 *
311 * Note 3: An INIT chunk MUST NOT contain more than one Host
312 * Name address parameter. Moreover, the sender of the INIT
313 * MUST NOT combine any other address types with the Host Name
314 * address in the INIT. The receiver of INIT MUST ignore any
315 * other address types if the Host Name address parameter is
316 * present in the received INIT chunk.
317 *
318 * PLEASE DO NOT FIXME [This version does not support Host Name.]
319 */
320
321 retval = sctp_make_control(asoc, SCTP_CID_INIT, 0, chunksize);
322 if (!retval)
323 goto nodata;
324
325 retval->subh.init_hdr =
326 sctp_addto_chunk(retval, sizeof(init), &init);
327 retval->param_hdr.v =
328 sctp_addto_chunk(retval, addrs_len, addrs.v);
329
330 /* RFC 2960 3.3.2 Initiation (INIT) (1)
331 *
332 * Note 4: This parameter, when present, specifies all the
333 * address types the sending endpoint can support. The absence
334 * of this parameter indicates that the sending endpoint can
335 * support any address type.
336 */
337 sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES;
338 sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types));
339 sctp_addto_chunk(retval, sizeof(sat), &sat);
340 sctp_addto_chunk(retval, num_types * sizeof(__u16), &types);
341
342 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
343
344 /* Add the supported extensions parameter. Be nice and add this
345 * fist before addiding the parameters for the extensions themselves
346 */
347 if (num_ext) {
348 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
349 ext_param.param_hdr.length =
350 htons(sizeof(sctp_supported_ext_param_t) + num_ext);
351 sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t),
352 &ext_param);
353 sctp_addto_param(retval, num_ext, extensions);
354 }
355
356 if (net->sctp.prsctp_enable)
357 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
358
359 if (sp->adaptation_ind) {
360 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
361 aiparam.param_hdr.length = htons(sizeof(aiparam));
362 aiparam.adaptation_ind = htonl(sp->adaptation_ind);
363 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
364 }
365
366 /* Add SCTP-AUTH chunks to the parameter list */
367 if (ep->auth_enable) {
368 sctp_addto_chunk(retval, sizeof(asoc->c.auth_random),
369 asoc->c.auth_random);
370 if (auth_hmacs)
371 sctp_addto_chunk(retval, ntohs(auth_hmacs->length),
372 auth_hmacs);
373 if (auth_chunks)
374 sctp_addto_chunk(retval, ntohs(auth_chunks->length),
375 auth_chunks);
376 }
377 nodata:
378 kfree(addrs.v);
379 return retval;
380 }
381
382 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc,
383 const struct sctp_chunk *chunk,
384 gfp_t gfp, int unkparam_len)
385 {
386 sctp_inithdr_t initack;
387 struct sctp_chunk *retval;
388 union sctp_params addrs;
389 struct sctp_sock *sp;
390 int addrs_len;
391 sctp_cookie_param_t *cookie;
392 int cookie_len;
393 size_t chunksize;
394 sctp_adaptation_ind_param_t aiparam;
395 sctp_supported_ext_param_t ext_param;
396 int num_ext = 0;
397 __u8 extensions[3];
398 sctp_paramhdr_t *auth_chunks = NULL,
399 *auth_hmacs = NULL,
400 *auth_random = NULL;
401
402 retval = NULL;
403
404 /* Note: there may be no addresses to embed. */
405 addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp);
406
407 initack.init_tag = htonl(asoc->c.my_vtag);
408 initack.a_rwnd = htonl(asoc->rwnd);
409 initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams);
410 initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams);
411 initack.initial_tsn = htonl(asoc->c.initial_tsn);
412
413 /* FIXME: We really ought to build the cookie right
414 * into the packet instead of allocating more fresh memory.
415 */
416 cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len,
417 addrs.v, addrs_len);
418 if (!cookie)
419 goto nomem_cookie;
420
421 /* Calculate the total size of allocation, include the reserved
422 * space for reporting unknown parameters if it is specified.
423 */
424 sp = sctp_sk(asoc->base.sk);
425 chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len;
426
427 /* Tell peer that we'll do ECN only if peer advertised such cap. */
428 if (asoc->peer.ecn_capable)
429 chunksize += sizeof(ecap_param);
430
431 if (asoc->peer.prsctp_capable)
432 chunksize += sizeof(prsctp_param);
433
434 if (asoc->peer.asconf_capable) {
435 extensions[num_ext] = SCTP_CID_ASCONF;
436 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
437 num_ext += 2;
438 }
439
440 if (sp->adaptation_ind)
441 chunksize += sizeof(aiparam);
442
443 if (asoc->peer.auth_capable) {
444 auth_random = (sctp_paramhdr_t *)asoc->c.auth_random;
445 chunksize += ntohs(auth_random->length);
446
447 auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs;
448 if (auth_hmacs->length)
449 chunksize += WORD_ROUND(ntohs(auth_hmacs->length));
450 else
451 auth_hmacs = NULL;
452
453 auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks;
454 if (auth_chunks->length)
455 chunksize += WORD_ROUND(ntohs(auth_chunks->length));
456 else
457 auth_chunks = NULL;
458
459 extensions[num_ext] = SCTP_CID_AUTH;
460 num_ext += 1;
461 }
462
463 if (num_ext)
464 chunksize += WORD_ROUND(sizeof(sctp_supported_ext_param_t) +
465 num_ext);
466
467 /* Now allocate and fill out the chunk. */
468 retval = sctp_make_control(asoc, SCTP_CID_INIT_ACK, 0, chunksize);
469 if (!retval)
470 goto nomem_chunk;
471
472 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
473 *
474 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
475 * HEARTBEAT ACK, * etc.) to the same destination transport
476 * address from which it received the DATA or control chunk
477 * to which it is replying.
478 *
479 * [INIT ACK back to where the INIT came from.]
480 */
481 retval->transport = chunk->transport;
482
483 retval->subh.init_hdr =
484 sctp_addto_chunk(retval, sizeof(initack), &initack);
485 retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v);
486 sctp_addto_chunk(retval, cookie_len, cookie);
487 if (asoc->peer.ecn_capable)
488 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
489 if (num_ext) {
490 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
491 ext_param.param_hdr.length =
492 htons(sizeof(sctp_supported_ext_param_t) + num_ext);
493 sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t),
494 &ext_param);
495 sctp_addto_param(retval, num_ext, extensions);
496 }
497 if (asoc->peer.prsctp_capable)
498 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
499
500 if (sp->adaptation_ind) {
501 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
502 aiparam.param_hdr.length = htons(sizeof(aiparam));
503 aiparam.adaptation_ind = htonl(sp->adaptation_ind);
504 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
505 }
506
507 if (asoc->peer.auth_capable) {
508 sctp_addto_chunk(retval, ntohs(auth_random->length),
509 auth_random);
510 if (auth_hmacs)
511 sctp_addto_chunk(retval, ntohs(auth_hmacs->length),
512 auth_hmacs);
513 if (auth_chunks)
514 sctp_addto_chunk(retval, ntohs(auth_chunks->length),
515 auth_chunks);
516 }
517
518 /* We need to remove the const qualifier at this point. */
519 retval->asoc = (struct sctp_association *) asoc;
520
521 nomem_chunk:
522 kfree(cookie);
523 nomem_cookie:
524 kfree(addrs.v);
525 return retval;
526 }
527
528 /* 3.3.11 Cookie Echo (COOKIE ECHO) (10):
529 *
530 * This chunk is used only during the initialization of an association.
531 * It is sent by the initiator of an association to its peer to complete
532 * the initialization process. This chunk MUST precede any DATA chunk
533 * sent within the association, but MAY be bundled with one or more DATA
534 * chunks in the same packet.
535 *
536 * 0 1 2 3
537 * 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
538 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
539 * | Type = 10 |Chunk Flags | Length |
540 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
541 * / Cookie /
542 * \ \
543 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
544 *
545 * Chunk Flags: 8 bit
546 *
547 * Set to zero on transmit and ignored on receipt.
548 *
549 * Length: 16 bits (unsigned integer)
550 *
551 * Set to the size of the chunk in bytes, including the 4 bytes of
552 * the chunk header and the size of the Cookie.
553 *
554 * Cookie: variable size
555 *
556 * This field must contain the exact cookie received in the
557 * State Cookie parameter from the previous INIT ACK.
558 *
559 * An implementation SHOULD make the cookie as small as possible
560 * to insure interoperability.
561 */
562 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc,
563 const struct sctp_chunk *chunk)
564 {
565 struct sctp_chunk *retval;
566 void *cookie;
567 int cookie_len;
568
569 cookie = asoc->peer.cookie;
570 cookie_len = asoc->peer.cookie_len;
571
572 /* Build a cookie echo chunk. */
573 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ECHO, 0, cookie_len);
574 if (!retval)
575 goto nodata;
576 retval->subh.cookie_hdr =
577 sctp_addto_chunk(retval, cookie_len, cookie);
578
579 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
580 *
581 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
582 * HEARTBEAT ACK, * etc.) to the same destination transport
583 * address from which it * received the DATA or control chunk
584 * to which it is replying.
585 *
586 * [COOKIE ECHO back to where the INIT ACK came from.]
587 */
588 if (chunk)
589 retval->transport = chunk->transport;
590
591 nodata:
592 return retval;
593 }
594
595 /* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11):
596 *
597 * This chunk is used only during the initialization of an
598 * association. It is used to acknowledge the receipt of a COOKIE
599 * ECHO chunk. This chunk MUST precede any DATA or SACK chunk sent
600 * within the association, but MAY be bundled with one or more DATA
601 * chunks or SACK chunk in the same SCTP packet.
602 *
603 * 0 1 2 3
604 * 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
605 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
606 * | Type = 11 |Chunk Flags | Length = 4 |
607 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
608 *
609 * Chunk Flags: 8 bits
610 *
611 * Set to zero on transmit and ignored on receipt.
612 */
613 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc,
614 const struct sctp_chunk *chunk)
615 {
616 struct sctp_chunk *retval;
617
618 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ACK, 0, 0);
619
620 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
621 *
622 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
623 * HEARTBEAT ACK, * etc.) to the same destination transport
624 * address from which it * received the DATA or control chunk
625 * to which it is replying.
626 *
627 * [COOKIE ACK back to where the COOKIE ECHO came from.]
628 */
629 if (retval && chunk)
630 retval->transport = chunk->transport;
631
632 return retval;
633 }
634
635 /*
636 * Appendix A: Explicit Congestion Notification:
637 * CWR:
638 *
639 * RFC 2481 details a specific bit for a sender to send in the header of
640 * its next outbound TCP segment to indicate to its peer that it has
641 * reduced its congestion window. This is termed the CWR bit. For
642 * SCTP the same indication is made by including the CWR chunk.
643 * This chunk contains one data element, i.e. the TSN number that
644 * was sent in the ECNE chunk. This element represents the lowest
645 * TSN number in the datagram that was originally marked with the
646 * CE bit.
647 *
648 * 0 1 2 3
649 * 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
650 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
651 * | Chunk Type=13 | Flags=00000000| Chunk Length = 8 |
652 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
653 * | Lowest TSN Number |
654 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
655 *
656 * Note: The CWR is considered a Control chunk.
657 */
658 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc,
659 const __u32 lowest_tsn,
660 const struct sctp_chunk *chunk)
661 {
662 struct sctp_chunk *retval;
663 sctp_cwrhdr_t cwr;
664
665 cwr.lowest_tsn = htonl(lowest_tsn);
666 retval = sctp_make_control(asoc, SCTP_CID_ECN_CWR, 0,
667 sizeof(sctp_cwrhdr_t));
668
669 if (!retval)
670 goto nodata;
671
672 retval->subh.ecn_cwr_hdr =
673 sctp_addto_chunk(retval, sizeof(cwr), &cwr);
674
675 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
676 *
677 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
678 * HEARTBEAT ACK, * etc.) to the same destination transport
679 * address from which it * received the DATA or control chunk
680 * to which it is replying.
681 *
682 * [Report a reduced congestion window back to where the ECNE
683 * came from.]
684 */
685 if (chunk)
686 retval->transport = chunk->transport;
687
688 nodata:
689 return retval;
690 }
691
692 /* Make an ECNE chunk. This is a congestion experienced report. */
693 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc,
694 const __u32 lowest_tsn)
695 {
696 struct sctp_chunk *retval;
697 sctp_ecnehdr_t ecne;
698
699 ecne.lowest_tsn = htonl(lowest_tsn);
700 retval = sctp_make_control(asoc, SCTP_CID_ECN_ECNE, 0,
701 sizeof(sctp_ecnehdr_t));
702 if (!retval)
703 goto nodata;
704 retval->subh.ecne_hdr =
705 sctp_addto_chunk(retval, sizeof(ecne), &ecne);
706
707 nodata:
708 return retval;
709 }
710
711 /* Make a DATA chunk for the given association from the provided
712 * parameters. However, do not populate the data payload.
713 */
714 struct sctp_chunk *sctp_make_datafrag_empty(struct sctp_association *asoc,
715 const struct sctp_sndrcvinfo *sinfo,
716 int data_len, __u8 flags, __u16 ssn)
717 {
718 struct sctp_chunk *retval;
719 struct sctp_datahdr dp;
720 int chunk_len;
721
722 /* We assign the TSN as LATE as possible, not here when
723 * creating the chunk.
724 */
725 dp.tsn = 0;
726 dp.stream = htons(sinfo->sinfo_stream);
727 dp.ppid = sinfo->sinfo_ppid;
728
729 /* Set the flags for an unordered send. */
730 if (sinfo->sinfo_flags & SCTP_UNORDERED) {
731 flags |= SCTP_DATA_UNORDERED;
732 dp.ssn = 0;
733 } else
734 dp.ssn = htons(ssn);
735
736 chunk_len = sizeof(dp) + data_len;
737 retval = sctp_make_data(asoc, flags, chunk_len);
738 if (!retval)
739 goto nodata;
740
741 retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp);
742 memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo));
743
744 nodata:
745 return retval;
746 }
747
748 /* Create a selective ackowledgement (SACK) for the given
749 * association. This reports on which TSN's we've seen to date,
750 * including duplicates and gaps.
751 */
752 struct sctp_chunk *sctp_make_sack(const struct sctp_association *asoc)
753 {
754 struct sctp_chunk *retval;
755 struct sctp_sackhdr sack;
756 int len;
757 __u32 ctsn;
758 __u16 num_gabs, num_dup_tsns;
759 struct sctp_association *aptr = (struct sctp_association *)asoc;
760 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
761 struct sctp_gap_ack_block gabs[SCTP_MAX_GABS];
762 struct sctp_transport *trans;
763
764 memset(gabs, 0, sizeof(gabs));
765 ctsn = sctp_tsnmap_get_ctsn(map);
766
767 pr_debug("%s: sackCTSNAck sent:0x%x\n", __func__, ctsn);
768
769 /* How much room is needed in the chunk? */
770 num_gabs = sctp_tsnmap_num_gabs(map, gabs);
771 num_dup_tsns = sctp_tsnmap_num_dups(map);
772
773 /* Initialize the SACK header. */
774 sack.cum_tsn_ack = htonl(ctsn);
775 sack.a_rwnd = htonl(asoc->a_rwnd);
776 sack.num_gap_ack_blocks = htons(num_gabs);
777 sack.num_dup_tsns = htons(num_dup_tsns);
778
779 len = sizeof(sack)
780 + sizeof(struct sctp_gap_ack_block) * num_gabs
781 + sizeof(__u32) * num_dup_tsns;
782
783 /* Create the chunk. */
784 retval = sctp_make_control(asoc, SCTP_CID_SACK, 0, len);
785 if (!retval)
786 goto nodata;
787
788 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
789 *
790 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
791 * HEARTBEAT ACK, etc.) to the same destination transport
792 * address from which it received the DATA or control chunk to
793 * which it is replying. This rule should also be followed if
794 * the endpoint is bundling DATA chunks together with the
795 * reply chunk.
796 *
797 * However, when acknowledging multiple DATA chunks received
798 * in packets from different source addresses in a single
799 * SACK, the SACK chunk may be transmitted to one of the
800 * destination transport addresses from which the DATA or
801 * control chunks being acknowledged were received.
802 *
803 * [BUG: We do not implement the following paragraph.
804 * Perhaps we should remember the last transport we used for a
805 * SACK and avoid that (if possible) if we have seen any
806 * duplicates. --piggy]
807 *
808 * When a receiver of a duplicate DATA chunk sends a SACK to a
809 * multi- homed endpoint it MAY be beneficial to vary the
810 * destination address and not use the source address of the
811 * DATA chunk. The reason being that receiving a duplicate
812 * from a multi-homed endpoint might indicate that the return
813 * path (as specified in the source address of the DATA chunk)
814 * for the SACK is broken.
815 *
816 * [Send to the address from which we last received a DATA chunk.]
817 */
818 retval->transport = asoc->peer.last_data_from;
819
820 retval->subh.sack_hdr =
821 sctp_addto_chunk(retval, sizeof(sack), &sack);
822
823 /* Add the gap ack block information. */
824 if (num_gabs)
825 sctp_addto_chunk(retval, sizeof(__u32) * num_gabs,
826 gabs);
827
828 /* Add the duplicate TSN information. */
829 if (num_dup_tsns) {
830 aptr->stats.idupchunks += num_dup_tsns;
831 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns,
832 sctp_tsnmap_get_dups(map));
833 }
834 /* Once we have a sack generated, check to see what our sack
835 * generation is, if its 0, reset the transports to 0, and reset
836 * the association generation to 1
837 *
838 * The idea is that zero is never used as a valid generation for the
839 * association so no transport will match after a wrap event like this,
840 * Until the next sack
841 */
842 if (++aptr->peer.sack_generation == 0) {
843 list_for_each_entry(trans, &asoc->peer.transport_addr_list,
844 transports)
845 trans->sack_generation = 0;
846 aptr->peer.sack_generation = 1;
847 }
848 nodata:
849 return retval;
850 }
851
852 /* Make a SHUTDOWN chunk. */
853 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc,
854 const struct sctp_chunk *chunk)
855 {
856 struct sctp_chunk *retval;
857 sctp_shutdownhdr_t shut;
858 __u32 ctsn;
859
860 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
861 shut.cum_tsn_ack = htonl(ctsn);
862
863 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN, 0,
864 sizeof(sctp_shutdownhdr_t));
865 if (!retval)
866 goto nodata;
867
868 retval->subh.shutdown_hdr =
869 sctp_addto_chunk(retval, sizeof(shut), &shut);
870
871 if (chunk)
872 retval->transport = chunk->transport;
873 nodata:
874 return retval;
875 }
876
877 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc,
878 const struct sctp_chunk *chunk)
879 {
880 struct sctp_chunk *retval;
881
882 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0);
883
884 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
885 *
886 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
887 * HEARTBEAT ACK, * etc.) to the same destination transport
888 * address from which it * received the DATA or control chunk
889 * to which it is replying.
890 *
891 * [ACK back to where the SHUTDOWN came from.]
892 */
893 if (retval && chunk)
894 retval->transport = chunk->transport;
895
896 return retval;
897 }
898
899 struct sctp_chunk *sctp_make_shutdown_complete(
900 const struct sctp_association *asoc,
901 const struct sctp_chunk *chunk)
902 {
903 struct sctp_chunk *retval;
904 __u8 flags = 0;
905
906 /* Set the T-bit if we have no association (vtag will be
907 * reflected)
908 */
909 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T;
910
911 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 0);
912
913 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
914 *
915 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
916 * HEARTBEAT ACK, * etc.) to the same destination transport
917 * address from which it * received the DATA or control chunk
918 * to which it is replying.
919 *
920 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK
921 * came from.]
922 */
923 if (retval && chunk)
924 retval->transport = chunk->transport;
925
926 return retval;
927 }
928
929 /* Create an ABORT. Note that we set the T bit if we have no
930 * association, except when responding to an INIT (sctpimpguide 2.41).
931 */
932 struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc,
933 const struct sctp_chunk *chunk,
934 const size_t hint)
935 {
936 struct sctp_chunk *retval;
937 __u8 flags = 0;
938
939 /* Set the T-bit if we have no association and 'chunk' is not
940 * an INIT (vtag will be reflected).
941 */
942 if (!asoc) {
943 if (chunk && chunk->chunk_hdr &&
944 chunk->chunk_hdr->type == SCTP_CID_INIT)
945 flags = 0;
946 else
947 flags = SCTP_CHUNK_FLAG_T;
948 }
949
950 retval = sctp_make_control(asoc, SCTP_CID_ABORT, flags, hint);
951
952 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
953 *
954 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
955 * HEARTBEAT ACK, * etc.) to the same destination transport
956 * address from which it * received the DATA or control chunk
957 * to which it is replying.
958 *
959 * [ABORT back to where the offender came from.]
960 */
961 if (retval && chunk)
962 retval->transport = chunk->transport;
963
964 return retval;
965 }
966
967 /* Helper to create ABORT with a NO_USER_DATA error. */
968 struct sctp_chunk *sctp_make_abort_no_data(
969 const struct sctp_association *asoc,
970 const struct sctp_chunk *chunk, __u32 tsn)
971 {
972 struct sctp_chunk *retval;
973 __be32 payload;
974
975 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t)
976 + sizeof(tsn));
977
978 if (!retval)
979 goto no_mem;
980
981 /* Put the tsn back into network byte order. */
982 payload = htonl(tsn);
983 sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload));
984 sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload);
985
986 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
987 *
988 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
989 * HEARTBEAT ACK, * etc.) to the same destination transport
990 * address from which it * received the DATA or control chunk
991 * to which it is replying.
992 *
993 * [ABORT back to where the offender came from.]
994 */
995 if (chunk)
996 retval->transport = chunk->transport;
997
998 no_mem:
999 return retval;
1000 }
1001
1002 /* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */
1003 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc,
1004 struct msghdr *msg,
1005 size_t paylen)
1006 {
1007 struct sctp_chunk *retval;
1008 void *payload = NULL;
1009 int err;
1010
1011 retval = sctp_make_abort(asoc, NULL, sizeof(sctp_errhdr_t) + paylen);
1012 if (!retval)
1013 goto err_chunk;
1014
1015 if (paylen) {
1016 /* Put the msg_iov together into payload. */
1017 payload = kmalloc(paylen, GFP_KERNEL);
1018 if (!payload)
1019 goto err_payload;
1020
1021 err = memcpy_from_msg(payload, msg, paylen);
1022 if (err < 0)
1023 goto err_copy;
1024 }
1025
1026 sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen);
1027 sctp_addto_chunk(retval, paylen, payload);
1028
1029 if (paylen)
1030 kfree(payload);
1031
1032 return retval;
1033
1034 err_copy:
1035 kfree(payload);
1036 err_payload:
1037 sctp_chunk_free(retval);
1038 retval = NULL;
1039 err_chunk:
1040 return retval;
1041 }
1042
1043 /* Append bytes to the end of a parameter. Will panic if chunk is not big
1044 * enough.
1045 */
1046 static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
1047 const void *data)
1048 {
1049 void *target;
1050 int chunklen = ntohs(chunk->chunk_hdr->length);
1051
1052 target = skb_put(chunk->skb, len);
1053
1054 if (data)
1055 memcpy(target, data, len);
1056 else
1057 memset(target, 0, len);
1058
1059 /* Adjust the chunk length field. */
1060 chunk->chunk_hdr->length = htons(chunklen + len);
1061 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1062
1063 return target;
1064 }
1065
1066 /* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */
1067 struct sctp_chunk *sctp_make_abort_violation(
1068 const struct sctp_association *asoc,
1069 const struct sctp_chunk *chunk,
1070 const __u8 *payload,
1071 const size_t paylen)
1072 {
1073 struct sctp_chunk *retval;
1074 struct sctp_paramhdr phdr;
1075
1076 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) + paylen
1077 + sizeof(sctp_paramhdr_t));
1078 if (!retval)
1079 goto end;
1080
1081 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen
1082 + sizeof(sctp_paramhdr_t));
1083
1084 phdr.type = htons(chunk->chunk_hdr->type);
1085 phdr.length = chunk->chunk_hdr->length;
1086 sctp_addto_chunk(retval, paylen, payload);
1087 sctp_addto_param(retval, sizeof(sctp_paramhdr_t), &phdr);
1088
1089 end:
1090 return retval;
1091 }
1092
1093 struct sctp_chunk *sctp_make_violation_paramlen(
1094 const struct sctp_association *asoc,
1095 const struct sctp_chunk *chunk,
1096 struct sctp_paramhdr *param)
1097 {
1098 struct sctp_chunk *retval;
1099 static const char error[] = "The following parameter had invalid length:";
1100 size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t) +
1101 sizeof(sctp_paramhdr_t);
1102
1103 retval = sctp_make_abort(asoc, chunk, payload_len);
1104 if (!retval)
1105 goto nodata;
1106
1107 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION,
1108 sizeof(error) + sizeof(sctp_paramhdr_t));
1109 sctp_addto_chunk(retval, sizeof(error), error);
1110 sctp_addto_param(retval, sizeof(sctp_paramhdr_t), param);
1111
1112 nodata:
1113 return retval;
1114 }
1115
1116 struct sctp_chunk *sctp_make_violation_max_retrans(
1117 const struct sctp_association *asoc,
1118 const struct sctp_chunk *chunk)
1119 {
1120 struct sctp_chunk *retval;
1121 static const char error[] = "Association exceeded its max_retans count";
1122 size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t);
1123
1124 retval = sctp_make_abort(asoc, chunk, payload_len);
1125 if (!retval)
1126 goto nodata;
1127
1128 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error));
1129 sctp_addto_chunk(retval, sizeof(error), error);
1130
1131 nodata:
1132 return retval;
1133 }
1134
1135 /* Make a HEARTBEAT chunk. */
1136 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc,
1137 const struct sctp_transport *transport)
1138 {
1139 struct sctp_chunk *retval;
1140 sctp_sender_hb_info_t hbinfo;
1141
1142 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT, 0, sizeof(hbinfo));
1143
1144 if (!retval)
1145 goto nodata;
1146
1147 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO;
1148 hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t));
1149 hbinfo.daddr = transport->ipaddr;
1150 hbinfo.sent_at = jiffies;
1151 hbinfo.hb_nonce = transport->hb_nonce;
1152
1153 /* Cast away the 'const', as this is just telling the chunk
1154 * what transport it belongs to.
1155 */
1156 retval->transport = (struct sctp_transport *) transport;
1157 retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo),
1158 &hbinfo);
1159
1160 nodata:
1161 return retval;
1162 }
1163
1164 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc,
1165 const struct sctp_chunk *chunk,
1166 const void *payload, const size_t paylen)
1167 {
1168 struct sctp_chunk *retval;
1169
1170 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen);
1171 if (!retval)
1172 goto nodata;
1173
1174 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload);
1175
1176 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
1177 *
1178 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1179 * HEARTBEAT ACK, * etc.) to the same destination transport
1180 * address from which it * received the DATA or control chunk
1181 * to which it is replying.
1182 *
1183 * [HBACK back to where the HEARTBEAT came from.]
1184 */
1185 if (chunk)
1186 retval->transport = chunk->transport;
1187
1188 nodata:
1189 return retval;
1190 }
1191
1192 /* Create an Operation Error chunk with the specified space reserved.
1193 * This routine can be used for containing multiple causes in the chunk.
1194 */
1195 static struct sctp_chunk *sctp_make_op_error_space(
1196 const struct sctp_association *asoc,
1197 const struct sctp_chunk *chunk,
1198 size_t size)
1199 {
1200 struct sctp_chunk *retval;
1201
1202 retval = sctp_make_control(asoc, SCTP_CID_ERROR, 0,
1203 sizeof(sctp_errhdr_t) + size);
1204 if (!retval)
1205 goto nodata;
1206
1207 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
1208 *
1209 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1210 * HEARTBEAT ACK, etc.) to the same destination transport
1211 * address from which it received the DATA or control chunk
1212 * to which it is replying.
1213 *
1214 */
1215 if (chunk)
1216 retval->transport = chunk->transport;
1217
1218 nodata:
1219 return retval;
1220 }
1221
1222 /* Create an Operation Error chunk of a fixed size,
1223 * specifically, max(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT)
1224 * This is a helper function to allocate an error chunk for
1225 * for those invalid parameter codes in which we may not want
1226 * to report all the errors, if the incoming chunk is large
1227 */
1228 static inline struct sctp_chunk *sctp_make_op_error_fixed(
1229 const struct sctp_association *asoc,
1230 const struct sctp_chunk *chunk)
1231 {
1232 size_t size = asoc ? asoc->pathmtu : 0;
1233
1234 if (!size)
1235 size = SCTP_DEFAULT_MAXSEGMENT;
1236
1237 return sctp_make_op_error_space(asoc, chunk, size);
1238 }
1239
1240 /* Create an Operation Error chunk. */
1241 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc,
1242 const struct sctp_chunk *chunk,
1243 __be16 cause_code, const void *payload,
1244 size_t paylen, size_t reserve_tail)
1245 {
1246 struct sctp_chunk *retval;
1247
1248 retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail);
1249 if (!retval)
1250 goto nodata;
1251
1252 sctp_init_cause(retval, cause_code, paylen + reserve_tail);
1253 sctp_addto_chunk(retval, paylen, payload);
1254 if (reserve_tail)
1255 sctp_addto_param(retval, reserve_tail, NULL);
1256
1257 nodata:
1258 return retval;
1259 }
1260
1261 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc)
1262 {
1263 struct sctp_chunk *retval;
1264 struct sctp_hmac *hmac_desc;
1265 struct sctp_authhdr auth_hdr;
1266 __u8 *hmac;
1267
1268 /* Get the first hmac that the peer told us to use */
1269 hmac_desc = sctp_auth_asoc_get_hmac(asoc);
1270 if (unlikely(!hmac_desc))
1271 return NULL;
1272
1273 retval = sctp_make_control(asoc, SCTP_CID_AUTH, 0,
1274 hmac_desc->hmac_len + sizeof(sctp_authhdr_t));
1275 if (!retval)
1276 return NULL;
1277
1278 auth_hdr.hmac_id = htons(hmac_desc->hmac_id);
1279 auth_hdr.shkey_id = htons(asoc->active_key_id);
1280
1281 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(sctp_authhdr_t),
1282 &auth_hdr);
1283
1284 hmac = skb_put(retval->skb, hmac_desc->hmac_len);
1285 memset(hmac, 0, hmac_desc->hmac_len);
1286
1287 /* Adjust the chunk header to include the empty MAC */
1288 retval->chunk_hdr->length =
1289 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len);
1290 retval->chunk_end = skb_tail_pointer(retval->skb);
1291
1292 return retval;
1293 }
1294
1295
1296 /********************************************************************
1297 * 2nd Level Abstractions
1298 ********************************************************************/
1299
1300 /* Turn an skb into a chunk.
1301 * FIXME: Eventually move the structure directly inside the skb->cb[].
1302 *
1303 * sctpimpguide-05.txt Section 2.8.2
1304 * M1) Each time a new DATA chunk is transmitted
1305 * set the 'TSN.Missing.Report' count for that TSN to 0. The
1306 * 'TSN.Missing.Report' count will be used to determine missing chunks
1307 * and when to fast retransmit.
1308 *
1309 */
1310 struct sctp_chunk *sctp_chunkify(struct sk_buff *skb,
1311 const struct sctp_association *asoc,
1312 struct sock *sk)
1313 {
1314 struct sctp_chunk *retval;
1315
1316 retval = kmem_cache_zalloc(sctp_chunk_cachep, GFP_ATOMIC);
1317
1318 if (!retval)
1319 goto nodata;
1320 if (!sk)
1321 pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb);
1322
1323 INIT_LIST_HEAD(&retval->list);
1324 retval->skb = skb;
1325 retval->asoc = (struct sctp_association *)asoc;
1326 retval->singleton = 1;
1327
1328 retval->fast_retransmit = SCTP_CAN_FRTX;
1329
1330 /* Polish the bead hole. */
1331 INIT_LIST_HEAD(&retval->transmitted_list);
1332 INIT_LIST_HEAD(&retval->frag_list);
1333 SCTP_DBG_OBJCNT_INC(chunk);
1334 atomic_set(&retval->refcnt, 1);
1335
1336 nodata:
1337 return retval;
1338 }
1339
1340 /* Set chunk->source and dest based on the IP header in chunk->skb. */
1341 void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src,
1342 union sctp_addr *dest)
1343 {
1344 memcpy(&chunk->source, src, sizeof(union sctp_addr));
1345 memcpy(&chunk->dest, dest, sizeof(union sctp_addr));
1346 }
1347
1348 /* Extract the source address from a chunk. */
1349 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk)
1350 {
1351 /* If we have a known transport, use that. */
1352 if (chunk->transport) {
1353 return &chunk->transport->ipaddr;
1354 } else {
1355 /* Otherwise, extract it from the IP header. */
1356 return &chunk->source;
1357 }
1358 }
1359
1360 /* Create a new chunk, setting the type and flags headers from the
1361 * arguments, reserving enough space for a 'paylen' byte payload.
1362 */
1363 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc,
1364 __u8 type, __u8 flags, int paylen)
1365 {
1366 struct sctp_chunk *retval;
1367 sctp_chunkhdr_t *chunk_hdr;
1368 struct sk_buff *skb;
1369 struct sock *sk;
1370
1371 /* No need to allocate LL here, as this is only a chunk. */
1372 skb = alloc_skb(WORD_ROUND(sizeof(sctp_chunkhdr_t) + paylen),
1373 GFP_ATOMIC);
1374 if (!skb)
1375 goto nodata;
1376
1377 /* Make room for the chunk header. */
1378 chunk_hdr = (sctp_chunkhdr_t *)skb_put(skb, sizeof(sctp_chunkhdr_t));
1379 chunk_hdr->type = type;
1380 chunk_hdr->flags = flags;
1381 chunk_hdr->length = htons(sizeof(sctp_chunkhdr_t));
1382
1383 sk = asoc ? asoc->base.sk : NULL;
1384 retval = sctp_chunkify(skb, asoc, sk);
1385 if (!retval) {
1386 kfree_skb(skb);
1387 goto nodata;
1388 }
1389
1390 retval->chunk_hdr = chunk_hdr;
1391 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(struct sctp_chunkhdr);
1392
1393 /* Determine if the chunk needs to be authenticated */
1394 if (sctp_auth_send_cid(type, asoc))
1395 retval->auth = 1;
1396
1397 return retval;
1398 nodata:
1399 return NULL;
1400 }
1401
1402 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc,
1403 __u8 flags, int paylen)
1404 {
1405 return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen);
1406 }
1407
1408 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc,
1409 __u8 type, __u8 flags, int paylen)
1410 {
1411 struct sctp_chunk *chunk = _sctp_make_chunk(asoc, type, flags, paylen);
1412
1413 if (chunk)
1414 sctp_control_set_owner_w(chunk);
1415
1416 return chunk;
1417 }
1418
1419 /* Release the memory occupied by a chunk. */
1420 static void sctp_chunk_destroy(struct sctp_chunk *chunk)
1421 {
1422 BUG_ON(!list_empty(&chunk->list));
1423 list_del_init(&chunk->transmitted_list);
1424
1425 consume_skb(chunk->skb);
1426 consume_skb(chunk->auth_chunk);
1427
1428 SCTP_DBG_OBJCNT_DEC(chunk);
1429 kmem_cache_free(sctp_chunk_cachep, chunk);
1430 }
1431
1432 /* Possibly, free the chunk. */
1433 void sctp_chunk_free(struct sctp_chunk *chunk)
1434 {
1435 /* Release our reference on the message tracker. */
1436 if (chunk->msg)
1437 sctp_datamsg_put(chunk->msg);
1438
1439 sctp_chunk_put(chunk);
1440 }
1441
1442 /* Grab a reference to the chunk. */
1443 void sctp_chunk_hold(struct sctp_chunk *ch)
1444 {
1445 atomic_inc(&ch->refcnt);
1446 }
1447
1448 /* Release a reference to the chunk. */
1449 void sctp_chunk_put(struct sctp_chunk *ch)
1450 {
1451 if (atomic_dec_and_test(&ch->refcnt))
1452 sctp_chunk_destroy(ch);
1453 }
1454
1455 /* Append bytes to the end of a chunk. Will panic if chunk is not big
1456 * enough.
1457 */
1458 void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data)
1459 {
1460 void *target;
1461 void *padding;
1462 int chunklen = ntohs(chunk->chunk_hdr->length);
1463 int padlen = WORD_ROUND(chunklen) - chunklen;
1464
1465 padding = skb_put(chunk->skb, padlen);
1466 target = skb_put(chunk->skb, len);
1467
1468 memset(padding, 0, padlen);
1469 memcpy(target, data, len);
1470
1471 /* Adjust the chunk length field. */
1472 chunk->chunk_hdr->length = htons(chunklen + padlen + len);
1473 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1474
1475 return target;
1476 }
1477
1478 /* Append bytes to the end of a chunk. Returns NULL if there isn't sufficient
1479 * space in the chunk
1480 */
1481 static void *sctp_addto_chunk_fixed(struct sctp_chunk *chunk,
1482 int len, const void *data)
1483 {
1484 if (skb_tailroom(chunk->skb) >= len)
1485 return sctp_addto_chunk(chunk, len, data);
1486 else
1487 return NULL;
1488 }
1489
1490 /* Append bytes from user space to the end of a chunk. Will panic if
1491 * chunk is not big enough.
1492 * Returns a kernel err value.
1493 */
1494 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
1495 struct iov_iter *from)
1496 {
1497 void *target;
1498 ssize_t copied;
1499
1500 /* Make room in chunk for data. */
1501 target = skb_put(chunk->skb, len);
1502
1503 /* Copy data (whole iovec) into chunk */
1504 copied = copy_from_iter(target, len, from);
1505 if (copied != len)
1506 return -EFAULT;
1507
1508 /* Adjust the chunk length field. */
1509 chunk->chunk_hdr->length =
1510 htons(ntohs(chunk->chunk_hdr->length) + len);
1511 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1512
1513 return 0;
1514 }
1515
1516 /* Helper function to assign a TSN if needed. This assumes that both
1517 * the data_hdr and association have already been assigned.
1518 */
1519 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk)
1520 {
1521 struct sctp_datamsg *msg;
1522 struct sctp_chunk *lchunk;
1523 struct sctp_stream *stream;
1524 __u16 ssn;
1525 __u16 sid;
1526
1527 if (chunk->has_ssn)
1528 return;
1529
1530 /* All fragments will be on the same stream */
1531 sid = ntohs(chunk->subh.data_hdr->stream);
1532 stream = &chunk->asoc->ssnmap->out;
1533
1534 /* Now assign the sequence number to the entire message.
1535 * All fragments must have the same stream sequence number.
1536 */
1537 msg = chunk->msg;
1538 list_for_each_entry(lchunk, &msg->chunks, frag_list) {
1539 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
1540 ssn = 0;
1541 } else {
1542 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG)
1543 ssn = sctp_ssn_next(stream, sid);
1544 else
1545 ssn = sctp_ssn_peek(stream, sid);
1546 }
1547
1548 lchunk->subh.data_hdr->ssn = htons(ssn);
1549 lchunk->has_ssn = 1;
1550 }
1551 }
1552
1553 /* Helper function to assign a TSN if needed. This assumes that both
1554 * the data_hdr and association have already been assigned.
1555 */
1556 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk)
1557 {
1558 if (!chunk->has_tsn) {
1559 /* This is the last possible instant to
1560 * assign a TSN.
1561 */
1562 chunk->subh.data_hdr->tsn =
1563 htonl(sctp_association_get_next_tsn(chunk->asoc));
1564 chunk->has_tsn = 1;
1565 }
1566 }
1567
1568 /* Create a CLOSED association to use with an incoming packet. */
1569 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep,
1570 struct sctp_chunk *chunk,
1571 gfp_t gfp)
1572 {
1573 struct sctp_association *asoc;
1574 struct sk_buff *skb;
1575 sctp_scope_t scope;
1576 struct sctp_af *af;
1577
1578 /* Create the bare association. */
1579 scope = sctp_scope(sctp_source(chunk));
1580 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp);
1581 if (!asoc)
1582 goto nodata;
1583 asoc->temp = 1;
1584 skb = chunk->skb;
1585 /* Create an entry for the source address of the packet. */
1586 af = sctp_get_af_specific(ipver2af(ip_hdr(skb)->version));
1587 if (unlikely(!af))
1588 goto fail;
1589 af->from_skb(&asoc->c.peer_addr, skb, 1);
1590 nodata:
1591 return asoc;
1592
1593 fail:
1594 sctp_association_free(asoc);
1595 return NULL;
1596 }
1597
1598 /* Build a cookie representing asoc.
1599 * This INCLUDES the param header needed to put the cookie in the INIT ACK.
1600 */
1601 static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep,
1602 const struct sctp_association *asoc,
1603 const struct sctp_chunk *init_chunk,
1604 int *cookie_len,
1605 const __u8 *raw_addrs, int addrs_len)
1606 {
1607 sctp_cookie_param_t *retval;
1608 struct sctp_signed_cookie *cookie;
1609 struct scatterlist sg;
1610 int headersize, bodysize;
1611
1612 /* Header size is static data prior to the actual cookie, including
1613 * any padding.
1614 */
1615 headersize = sizeof(sctp_paramhdr_t) +
1616 (sizeof(struct sctp_signed_cookie) -
1617 sizeof(struct sctp_cookie));
1618 bodysize = sizeof(struct sctp_cookie)
1619 + ntohs(init_chunk->chunk_hdr->length) + addrs_len;
1620
1621 /* Pad out the cookie to a multiple to make the signature
1622 * functions simpler to write.
1623 */
1624 if (bodysize % SCTP_COOKIE_MULTIPLE)
1625 bodysize += SCTP_COOKIE_MULTIPLE
1626 - (bodysize % SCTP_COOKIE_MULTIPLE);
1627 *cookie_len = headersize + bodysize;
1628
1629 /* Clear this memory since we are sending this data structure
1630 * out on the network.
1631 */
1632 retval = kzalloc(*cookie_len, GFP_ATOMIC);
1633 if (!retval)
1634 goto nodata;
1635
1636 cookie = (struct sctp_signed_cookie *) retval->body;
1637
1638 /* Set up the parameter header. */
1639 retval->p.type = SCTP_PARAM_STATE_COOKIE;
1640 retval->p.length = htons(*cookie_len);
1641
1642 /* Copy the cookie part of the association itself. */
1643 cookie->c = asoc->c;
1644 /* Save the raw address list length in the cookie. */
1645 cookie->c.raw_addr_list_len = addrs_len;
1646
1647 /* Remember PR-SCTP capability. */
1648 cookie->c.prsctp_capable = asoc->peer.prsctp_capable;
1649
1650 /* Save adaptation indication in the cookie. */
1651 cookie->c.adaptation_ind = asoc->peer.adaptation_ind;
1652
1653 /* Set an expiration time for the cookie. */
1654 cookie->c.expiration = ktime_add(asoc->cookie_life,
1655 ktime_get_real());
1656
1657 /* Copy the peer's init packet. */
1658 memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr,
1659 ntohs(init_chunk->chunk_hdr->length));
1660
1661 /* Copy the raw local address list of the association. */
1662 memcpy((__u8 *)&cookie->c.peer_init[0] +
1663 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len);
1664
1665 if (sctp_sk(ep->base.sk)->hmac) {
1666 struct hash_desc desc;
1667
1668 /* Sign the message. */
1669 sg_init_one(&sg, &cookie->c, bodysize);
1670 desc.tfm = sctp_sk(ep->base.sk)->hmac;
1671 desc.flags = 0;
1672
1673 if (crypto_hash_setkey(desc.tfm, ep->secret_key,
1674 sizeof(ep->secret_key)) ||
1675 crypto_hash_digest(&desc, &sg, bodysize, cookie->signature))
1676 goto free_cookie;
1677 }
1678
1679 return retval;
1680
1681 free_cookie:
1682 kfree(retval);
1683 nodata:
1684 *cookie_len = 0;
1685 return NULL;
1686 }
1687
1688 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */
1689 struct sctp_association *sctp_unpack_cookie(
1690 const struct sctp_endpoint *ep,
1691 const struct sctp_association *asoc,
1692 struct sctp_chunk *chunk, gfp_t gfp,
1693 int *error, struct sctp_chunk **errp)
1694 {
1695 struct sctp_association *retval = NULL;
1696 struct sctp_signed_cookie *cookie;
1697 struct sctp_cookie *bear_cookie;
1698 int headersize, bodysize, fixed_size;
1699 __u8 *digest = ep->digest;
1700 struct scatterlist sg;
1701 unsigned int len;
1702 sctp_scope_t scope;
1703 struct sk_buff *skb = chunk->skb;
1704 ktime_t kt;
1705 struct hash_desc desc;
1706
1707 /* Header size is static data prior to the actual cookie, including
1708 * any padding.
1709 */
1710 headersize = sizeof(sctp_chunkhdr_t) +
1711 (sizeof(struct sctp_signed_cookie) -
1712 sizeof(struct sctp_cookie));
1713 bodysize = ntohs(chunk->chunk_hdr->length) - headersize;
1714 fixed_size = headersize + sizeof(struct sctp_cookie);
1715
1716 /* Verify that the chunk looks like it even has a cookie.
1717 * There must be enough room for our cookie and our peer's
1718 * INIT chunk.
1719 */
1720 len = ntohs(chunk->chunk_hdr->length);
1721 if (len < fixed_size + sizeof(struct sctp_chunkhdr))
1722 goto malformed;
1723
1724 /* Verify that the cookie has been padded out. */
1725 if (bodysize % SCTP_COOKIE_MULTIPLE)
1726 goto malformed;
1727
1728 /* Process the cookie. */
1729 cookie = chunk->subh.cookie_hdr;
1730 bear_cookie = &cookie->c;
1731
1732 if (!sctp_sk(ep->base.sk)->hmac)
1733 goto no_hmac;
1734
1735 /* Check the signature. */
1736 sg_init_one(&sg, bear_cookie, bodysize);
1737 desc.tfm = sctp_sk(ep->base.sk)->hmac;
1738 desc.flags = 0;
1739
1740 memset(digest, 0x00, SCTP_SIGNATURE_SIZE);
1741 if (crypto_hash_setkey(desc.tfm, ep->secret_key,
1742 sizeof(ep->secret_key)) ||
1743 crypto_hash_digest(&desc, &sg, bodysize, digest)) {
1744 *error = -SCTP_IERROR_NOMEM;
1745 goto fail;
1746 }
1747
1748 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
1749 *error = -SCTP_IERROR_BAD_SIG;
1750 goto fail;
1751 }
1752
1753 no_hmac:
1754 /* IG Section 2.35.2:
1755 * 3) Compare the port numbers and the verification tag contained
1756 * within the COOKIE ECHO chunk to the actual port numbers and the
1757 * verification tag within the SCTP common header of the received
1758 * packet. If these values do not match the packet MUST be silently
1759 * discarded,
1760 */
1761 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) {
1762 *error = -SCTP_IERROR_BAD_TAG;
1763 goto fail;
1764 }
1765
1766 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port ||
1767 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) {
1768 *error = -SCTP_IERROR_BAD_PORTS;
1769 goto fail;
1770 }
1771
1772 /* Check to see if the cookie is stale. If there is already
1773 * an association, there is no need to check cookie's expiration
1774 * for init collision case of lost COOKIE ACK.
1775 * If skb has been timestamped, then use the stamp, otherwise
1776 * use current time. This introduces a small possibility that
1777 * that a cookie may be considered expired, but his would only slow
1778 * down the new association establishment instead of every packet.
1779 */
1780 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP))
1781 kt = skb_get_ktime(skb);
1782 else
1783 kt = ktime_get_real();
1784
1785 if (!asoc && ktime_before(bear_cookie->expiration, kt)) {
1786 /*
1787 * Section 3.3.10.3 Stale Cookie Error (3)
1788 *
1789 * Cause of error
1790 * ---------------
1791 * Stale Cookie Error: Indicates the receipt of a valid State
1792 * Cookie that has expired.
1793 */
1794 len = ntohs(chunk->chunk_hdr->length);
1795 *errp = sctp_make_op_error_space(asoc, chunk, len);
1796 if (*errp) {
1797 suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration));
1798 __be32 n = htonl(usecs);
1799
1800 sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE,
1801 sizeof(n));
1802 sctp_addto_chunk(*errp, sizeof(n), &n);
1803 *error = -SCTP_IERROR_STALE_COOKIE;
1804 } else
1805 *error = -SCTP_IERROR_NOMEM;
1806
1807 goto fail;
1808 }
1809
1810 /* Make a new base association. */
1811 scope = sctp_scope(sctp_source(chunk));
1812 retval = sctp_association_new(ep, ep->base.sk, scope, gfp);
1813 if (!retval) {
1814 *error = -SCTP_IERROR_NOMEM;
1815 goto fail;
1816 }
1817
1818 /* Set up our peer's port number. */
1819 retval->peer.port = ntohs(chunk->sctp_hdr->source);
1820
1821 /* Populate the association from the cookie. */
1822 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie));
1823
1824 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie,
1825 GFP_ATOMIC) < 0) {
1826 *error = -SCTP_IERROR_NOMEM;
1827 goto fail;
1828 }
1829
1830 /* Also, add the destination address. */
1831 if (list_empty(&retval->base.bind_addr.address_list)) {
1832 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest,
1833 sizeof(chunk->dest), SCTP_ADDR_SRC,
1834 GFP_ATOMIC);
1835 }
1836
1837 retval->next_tsn = retval->c.initial_tsn;
1838 retval->ctsn_ack_point = retval->next_tsn - 1;
1839 retval->addip_serial = retval->c.initial_tsn;
1840 retval->adv_peer_ack_point = retval->ctsn_ack_point;
1841 retval->peer.prsctp_capable = retval->c.prsctp_capable;
1842 retval->peer.adaptation_ind = retval->c.adaptation_ind;
1843
1844 /* The INIT stuff will be done by the side effects. */
1845 return retval;
1846
1847 fail:
1848 if (retval)
1849 sctp_association_free(retval);
1850
1851 return NULL;
1852
1853 malformed:
1854 /* Yikes! The packet is either corrupt or deliberately
1855 * malformed.
1856 */
1857 *error = -SCTP_IERROR_MALFORMED;
1858 goto fail;
1859 }
1860
1861 /********************************************************************
1862 * 3rd Level Abstractions
1863 ********************************************************************/
1864
1865 struct __sctp_missing {
1866 __be32 num_missing;
1867 __be16 type;
1868 } __packed;
1869
1870 /*
1871 * Report a missing mandatory parameter.
1872 */
1873 static int sctp_process_missing_param(const struct sctp_association *asoc,
1874 sctp_param_t paramtype,
1875 struct sctp_chunk *chunk,
1876 struct sctp_chunk **errp)
1877 {
1878 struct __sctp_missing report;
1879 __u16 len;
1880
1881 len = WORD_ROUND(sizeof(report));
1882
1883 /* Make an ERROR chunk, preparing enough room for
1884 * returning multiple unknown parameters.
1885 */
1886 if (!*errp)
1887 *errp = sctp_make_op_error_space(asoc, chunk, len);
1888
1889 if (*errp) {
1890 report.num_missing = htonl(1);
1891 report.type = paramtype;
1892 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM,
1893 sizeof(report));
1894 sctp_addto_chunk(*errp, sizeof(report), &report);
1895 }
1896
1897 /* Stop processing this chunk. */
1898 return 0;
1899 }
1900
1901 /* Report an Invalid Mandatory Parameter. */
1902 static int sctp_process_inv_mandatory(const struct sctp_association *asoc,
1903 struct sctp_chunk *chunk,
1904 struct sctp_chunk **errp)
1905 {
1906 /* Invalid Mandatory Parameter Error has no payload. */
1907
1908 if (!*errp)
1909 *errp = sctp_make_op_error_space(asoc, chunk, 0);
1910
1911 if (*errp)
1912 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0);
1913
1914 /* Stop processing this chunk. */
1915 return 0;
1916 }
1917
1918 static int sctp_process_inv_paramlength(const struct sctp_association *asoc,
1919 struct sctp_paramhdr *param,
1920 const struct sctp_chunk *chunk,
1921 struct sctp_chunk **errp)
1922 {
1923 /* This is a fatal error. Any accumulated non-fatal errors are
1924 * not reported.
1925 */
1926 if (*errp)
1927 sctp_chunk_free(*errp);
1928
1929 /* Create an error chunk and fill it in with our payload. */
1930 *errp = sctp_make_violation_paramlen(asoc, chunk, param);
1931
1932 return 0;
1933 }
1934
1935
1936 /* Do not attempt to handle the HOST_NAME parm. However, do
1937 * send back an indicator to the peer.
1938 */
1939 static int sctp_process_hn_param(const struct sctp_association *asoc,
1940 union sctp_params param,
1941 struct sctp_chunk *chunk,
1942 struct sctp_chunk **errp)
1943 {
1944 __u16 len = ntohs(param.p->length);
1945
1946 /* Processing of the HOST_NAME parameter will generate an
1947 * ABORT. If we've accumulated any non-fatal errors, they
1948 * would be unrecognized parameters and we should not include
1949 * them in the ABORT.
1950 */
1951 if (*errp)
1952 sctp_chunk_free(*errp);
1953
1954 *errp = sctp_make_op_error_space(asoc, chunk, len);
1955
1956 if (*errp) {
1957 sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, len);
1958 sctp_addto_chunk(*errp, len, param.v);
1959 }
1960
1961 /* Stop processing this chunk. */
1962 return 0;
1963 }
1964
1965 static int sctp_verify_ext_param(struct net *net, union sctp_params param)
1966 {
1967 __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
1968 int have_auth = 0;
1969 int have_asconf = 0;
1970 int i;
1971
1972 for (i = 0; i < num_ext; i++) {
1973 switch (param.ext->chunks[i]) {
1974 case SCTP_CID_AUTH:
1975 have_auth = 1;
1976 break;
1977 case SCTP_CID_ASCONF:
1978 case SCTP_CID_ASCONF_ACK:
1979 have_asconf = 1;
1980 break;
1981 }
1982 }
1983
1984 /* ADD-IP Security: The draft requires us to ABORT or ignore the
1985 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this
1986 * only if ADD-IP is turned on and we are not backward-compatible
1987 * mode.
1988 */
1989 if (net->sctp.addip_noauth)
1990 return 1;
1991
1992 if (net->sctp.addip_enable && !have_auth && have_asconf)
1993 return 0;
1994
1995 return 1;
1996 }
1997
1998 static void sctp_process_ext_param(struct sctp_association *asoc,
1999 union sctp_params param)
2000 {
2001 struct net *net = sock_net(asoc->base.sk);
2002 __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
2003 int i;
2004
2005 for (i = 0; i < num_ext; i++) {
2006 switch (param.ext->chunks[i]) {
2007 case SCTP_CID_FWD_TSN:
2008 if (net->sctp.prsctp_enable && !asoc->peer.prsctp_capable)
2009 asoc->peer.prsctp_capable = 1;
2010 break;
2011 case SCTP_CID_AUTH:
2012 /* if the peer reports AUTH, assume that he
2013 * supports AUTH.
2014 */
2015 if (asoc->ep->auth_enable)
2016 asoc->peer.auth_capable = 1;
2017 break;
2018 case SCTP_CID_ASCONF:
2019 case SCTP_CID_ASCONF_ACK:
2020 if (net->sctp.addip_enable)
2021 asoc->peer.asconf_capable = 1;
2022 break;
2023 default:
2024 break;
2025 }
2026 }
2027 }
2028
2029 /* RFC 3.2.1 & the Implementers Guide 2.2.
2030 *
2031 * The Parameter Types are encoded such that the
2032 * highest-order two bits specify the action that must be
2033 * taken if the processing endpoint does not recognize the
2034 * Parameter Type.
2035 *
2036 * 00 - Stop processing this parameter; do not process any further
2037 * parameters within this chunk
2038 *
2039 * 01 - Stop processing this parameter, do not process any further
2040 * parameters within this chunk, and report the unrecognized
2041 * parameter in an 'Unrecognized Parameter' ERROR chunk.
2042 *
2043 * 10 - Skip this parameter and continue processing.
2044 *
2045 * 11 - Skip this parameter and continue processing but
2046 * report the unrecognized parameter in an
2047 * 'Unrecognized Parameter' ERROR chunk.
2048 *
2049 * Return value:
2050 * SCTP_IERROR_NO_ERROR - continue with the chunk
2051 * SCTP_IERROR_ERROR - stop and report an error.
2052 * SCTP_IERROR_NOMEME - out of memory.
2053 */
2054 static sctp_ierror_t sctp_process_unk_param(const struct sctp_association *asoc,
2055 union sctp_params param,
2056 struct sctp_chunk *chunk,
2057 struct sctp_chunk **errp)
2058 {
2059 int retval = SCTP_IERROR_NO_ERROR;
2060
2061 switch (param.p->type & SCTP_PARAM_ACTION_MASK) {
2062 case SCTP_PARAM_ACTION_DISCARD:
2063 retval = SCTP_IERROR_ERROR;
2064 break;
2065 case SCTP_PARAM_ACTION_SKIP:
2066 break;
2067 case SCTP_PARAM_ACTION_DISCARD_ERR:
2068 retval = SCTP_IERROR_ERROR;
2069 /* Fall through */
2070 case SCTP_PARAM_ACTION_SKIP_ERR:
2071 /* Make an ERROR chunk, preparing enough room for
2072 * returning multiple unknown parameters.
2073 */
2074 if (NULL == *errp)
2075 *errp = sctp_make_op_error_fixed(asoc, chunk);
2076
2077 if (*errp) {
2078 if (!sctp_init_cause_fixed(*errp, SCTP_ERROR_UNKNOWN_PARAM,
2079 WORD_ROUND(ntohs(param.p->length))))
2080 sctp_addto_chunk_fixed(*errp,
2081 WORD_ROUND(ntohs(param.p->length)),
2082 param.v);
2083 } else {
2084 /* If there is no memory for generating the ERROR
2085 * report as specified, an ABORT will be triggered
2086 * to the peer and the association won't be
2087 * established.
2088 */
2089 retval = SCTP_IERROR_NOMEM;
2090 }
2091 break;
2092 default:
2093 break;
2094 }
2095
2096 return retval;
2097 }
2098
2099 /* Verify variable length parameters
2100 * Return values:
2101 * SCTP_IERROR_ABORT - trigger an ABORT
2102 * SCTP_IERROR_NOMEM - out of memory (abort)
2103 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR
2104 * SCTP_IERROR_NO_ERROR - continue with the chunk
2105 */
2106 static sctp_ierror_t sctp_verify_param(struct net *net,
2107 const struct sctp_endpoint *ep,
2108 const struct sctp_association *asoc,
2109 union sctp_params param,
2110 sctp_cid_t cid,
2111 struct sctp_chunk *chunk,
2112 struct sctp_chunk **err_chunk)
2113 {
2114 struct sctp_hmac_algo_param *hmacs;
2115 int retval = SCTP_IERROR_NO_ERROR;
2116 __u16 n_elt, id = 0;
2117 int i;
2118
2119 /* FIXME - This routine is not looking at each parameter per the
2120 * chunk type, i.e., unrecognized parameters should be further
2121 * identified based on the chunk id.
2122 */
2123
2124 switch (param.p->type) {
2125 case SCTP_PARAM_IPV4_ADDRESS:
2126 case SCTP_PARAM_IPV6_ADDRESS:
2127 case SCTP_PARAM_COOKIE_PRESERVATIVE:
2128 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
2129 case SCTP_PARAM_STATE_COOKIE:
2130 case SCTP_PARAM_HEARTBEAT_INFO:
2131 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
2132 case SCTP_PARAM_ECN_CAPABLE:
2133 case SCTP_PARAM_ADAPTATION_LAYER_IND:
2134 break;
2135
2136 case SCTP_PARAM_SUPPORTED_EXT:
2137 if (!sctp_verify_ext_param(net, param))
2138 return SCTP_IERROR_ABORT;
2139 break;
2140
2141 case SCTP_PARAM_SET_PRIMARY:
2142 if (net->sctp.addip_enable)
2143 break;
2144 goto fallthrough;
2145
2146 case SCTP_PARAM_HOST_NAME_ADDRESS:
2147 /* Tell the peer, we won't support this param. */
2148 sctp_process_hn_param(asoc, param, chunk, err_chunk);
2149 retval = SCTP_IERROR_ABORT;
2150 break;
2151
2152 case SCTP_PARAM_FWD_TSN_SUPPORT:
2153 if (net->sctp.prsctp_enable)
2154 break;
2155 goto fallthrough;
2156
2157 case SCTP_PARAM_RANDOM:
2158 if (!ep->auth_enable)
2159 goto fallthrough;
2160
2161 /* SCTP-AUTH: Secion 6.1
2162 * If the random number is not 32 byte long the association
2163 * MUST be aborted. The ABORT chunk SHOULD contain the error
2164 * cause 'Protocol Violation'.
2165 */
2166 if (SCTP_AUTH_RANDOM_LENGTH !=
2167 ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) {
2168 sctp_process_inv_paramlength(asoc, param.p,
2169 chunk, err_chunk);
2170 retval = SCTP_IERROR_ABORT;
2171 }
2172 break;
2173
2174 case SCTP_PARAM_CHUNKS:
2175 if (!ep->auth_enable)
2176 goto fallthrough;
2177
2178 /* SCTP-AUTH: Section 3.2
2179 * The CHUNKS parameter MUST be included once in the INIT or
2180 * INIT-ACK chunk if the sender wants to receive authenticated
2181 * chunks. Its maximum length is 260 bytes.
2182 */
2183 if (260 < ntohs(param.p->length)) {
2184 sctp_process_inv_paramlength(asoc, param.p,
2185 chunk, err_chunk);
2186 retval = SCTP_IERROR_ABORT;
2187 }
2188 break;
2189
2190 case SCTP_PARAM_HMAC_ALGO:
2191 if (!ep->auth_enable)
2192 goto fallthrough;
2193
2194 hmacs = (struct sctp_hmac_algo_param *)param.p;
2195 n_elt = (ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) >> 1;
2196
2197 /* SCTP-AUTH: Section 6.1
2198 * The HMAC algorithm based on SHA-1 MUST be supported and
2199 * included in the HMAC-ALGO parameter.
2200 */
2201 for (i = 0; i < n_elt; i++) {
2202 id = ntohs(hmacs->hmac_ids[i]);
2203
2204 if (id == SCTP_AUTH_HMAC_ID_SHA1)
2205 break;
2206 }
2207
2208 if (id != SCTP_AUTH_HMAC_ID_SHA1) {
2209 sctp_process_inv_paramlength(asoc, param.p, chunk,
2210 err_chunk);
2211 retval = SCTP_IERROR_ABORT;
2212 }
2213 break;
2214 fallthrough:
2215 default:
2216 pr_debug("%s: unrecognized param:%d for chunk:%d\n",
2217 __func__, ntohs(param.p->type), cid);
2218
2219 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk);
2220 break;
2221 }
2222 return retval;
2223 }
2224
2225 /* Verify the INIT packet before we process it. */
2226 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
2227 const struct sctp_association *asoc, sctp_cid_t cid,
2228 sctp_init_chunk_t *peer_init, struct sctp_chunk *chunk,
2229 struct sctp_chunk **errp)
2230 {
2231 union sctp_params param;
2232 bool has_cookie = false;
2233 int result;
2234
2235 /* Check for missing mandatory parameters. Note: Initial TSN is
2236 * also mandatory, but is not checked here since the valid range
2237 * is 0..2**32-1. RFC4960, section 3.3.3.
2238 */
2239 if (peer_init->init_hdr.num_outbound_streams == 0 ||
2240 peer_init->init_hdr.num_inbound_streams == 0 ||
2241 peer_init->init_hdr.init_tag == 0 ||
2242 ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW)
2243 return sctp_process_inv_mandatory(asoc, chunk, errp);
2244
2245 sctp_walk_params(param, peer_init, init_hdr.params) {
2246 if (param.p->type == SCTP_PARAM_STATE_COOKIE)
2247 has_cookie = true;
2248 }
2249
2250 /* There is a possibility that a parameter length was bad and
2251 * in that case we would have stoped walking the parameters.
2252 * The current param.p would point at the bad one.
2253 * Current consensus on the mailing list is to generate a PROTOCOL
2254 * VIOLATION error. We build the ERROR chunk here and let the normal
2255 * error handling code build and send the packet.
2256 */
2257 if (param.v != (void *)chunk->chunk_end)
2258 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp);
2259
2260 /* The only missing mandatory param possible today is
2261 * the state cookie for an INIT-ACK chunk.
2262 */
2263 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie)
2264 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE,
2265 chunk, errp);
2266
2267 /* Verify all the variable length parameters */
2268 sctp_walk_params(param, peer_init, init_hdr.params) {
2269 result = sctp_verify_param(net, ep, asoc, param, cid,
2270 chunk, errp);
2271 switch (result) {
2272 case SCTP_IERROR_ABORT:
2273 case SCTP_IERROR_NOMEM:
2274 return 0;
2275 case SCTP_IERROR_ERROR:
2276 return 1;
2277 case SCTP_IERROR_NO_ERROR:
2278 default:
2279 break;
2280 }
2281
2282 } /* for (loop through all parameters) */
2283
2284 return 1;
2285 }
2286
2287 /* Unpack the parameters in an INIT packet into an association.
2288 * Returns 0 on failure, else success.
2289 * FIXME: This is an association method.
2290 */
2291 int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk,
2292 const union sctp_addr *peer_addr,
2293 sctp_init_chunk_t *peer_init, gfp_t gfp)
2294 {
2295 struct net *net = sock_net(asoc->base.sk);
2296 union sctp_params param;
2297 struct sctp_transport *transport;
2298 struct list_head *pos, *temp;
2299 struct sctp_af *af;
2300 union sctp_addr addr;
2301 char *cookie;
2302 int src_match = 0;
2303
2304 /* We must include the address that the INIT packet came from.
2305 * This is the only address that matters for an INIT packet.
2306 * When processing a COOKIE ECHO, we retrieve the from address
2307 * of the INIT from the cookie.
2308 */
2309
2310 /* This implementation defaults to making the first transport
2311 * added as the primary transport. The source address seems to
2312 * be a a better choice than any of the embedded addresses.
2313 */
2314 if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE))
2315 goto nomem;
2316
2317 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr))
2318 src_match = 1;
2319
2320 /* Process the initialization parameters. */
2321 sctp_walk_params(param, peer_init, init_hdr.params) {
2322 if (!src_match && (param.p->type == SCTP_PARAM_IPV4_ADDRESS ||
2323 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) {
2324 af = sctp_get_af_specific(param_type2af(param.p->type));
2325 af->from_addr_param(&addr, param.addr,
2326 chunk->sctp_hdr->source, 0);
2327 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr))
2328 src_match = 1;
2329 }
2330
2331 if (!sctp_process_param(asoc, param, peer_addr, gfp))
2332 goto clean_up;
2333 }
2334
2335 /* source address of chunk may not match any valid address */
2336 if (!src_match)
2337 goto clean_up;
2338
2339 /* AUTH: After processing the parameters, make sure that we
2340 * have all the required info to potentially do authentications.
2341 */
2342 if (asoc->peer.auth_capable && (!asoc->peer.peer_random ||
2343 !asoc->peer.peer_hmacs))
2344 asoc->peer.auth_capable = 0;
2345
2346 /* In a non-backward compatible mode, if the peer claims
2347 * support for ADD-IP but not AUTH, the ADD-IP spec states
2348 * that we MUST ABORT the association. Section 6. The section
2349 * also give us an option to silently ignore the packet, which
2350 * is what we'll do here.
2351 */
2352 if (!net->sctp.addip_noauth &&
2353 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) {
2354 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP |
2355 SCTP_PARAM_DEL_IP |
2356 SCTP_PARAM_SET_PRIMARY);
2357 asoc->peer.asconf_capable = 0;
2358 goto clean_up;
2359 }
2360
2361 /* Walk list of transports, removing transports in the UNKNOWN state. */
2362 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
2363 transport = list_entry(pos, struct sctp_transport, transports);
2364 if (transport->state == SCTP_UNKNOWN) {
2365 sctp_assoc_rm_peer(asoc, transport);
2366 }
2367 }
2368
2369 /* The fixed INIT headers are always in network byte
2370 * order.
2371 */
2372 asoc->peer.i.init_tag =
2373 ntohl(peer_init->init_hdr.init_tag);
2374 asoc->peer.i.a_rwnd =
2375 ntohl(peer_init->init_hdr.a_rwnd);
2376 asoc->peer.i.num_outbound_streams =
2377 ntohs(peer_init->init_hdr.num_outbound_streams);
2378 asoc->peer.i.num_inbound_streams =
2379 ntohs(peer_init->init_hdr.num_inbound_streams);
2380 asoc->peer.i.initial_tsn =
2381 ntohl(peer_init->init_hdr.initial_tsn);
2382
2383 /* Apply the upper bounds for output streams based on peer's
2384 * number of inbound streams.
2385 */
2386 if (asoc->c.sinit_num_ostreams >
2387 ntohs(peer_init->init_hdr.num_inbound_streams)) {
2388 asoc->c.sinit_num_ostreams =
2389 ntohs(peer_init->init_hdr.num_inbound_streams);
2390 }
2391
2392 if (asoc->c.sinit_max_instreams >
2393 ntohs(peer_init->init_hdr.num_outbound_streams)) {
2394 asoc->c.sinit_max_instreams =
2395 ntohs(peer_init->init_hdr.num_outbound_streams);
2396 }
2397
2398 /* Copy Initiation tag from INIT to VT_peer in cookie. */
2399 asoc->c.peer_vtag = asoc->peer.i.init_tag;
2400
2401 /* Peer Rwnd : Current calculated value of the peer's rwnd. */
2402 asoc->peer.rwnd = asoc->peer.i.a_rwnd;
2403
2404 /* Copy cookie in case we need to resend COOKIE-ECHO. */
2405 cookie = asoc->peer.cookie;
2406 if (cookie) {
2407 asoc->peer.cookie = kmemdup(cookie, asoc->peer.cookie_len, gfp);
2408 if (!asoc->peer.cookie)
2409 goto clean_up;
2410 }
2411
2412 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily
2413 * high (for example, implementations MAY use the size of the receiver
2414 * advertised window).
2415 */
2416 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
2417 transports) {
2418 transport->ssthresh = asoc->peer.i.a_rwnd;
2419 }
2420
2421 /* Set up the TSN tracking pieces. */
2422 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
2423 asoc->peer.i.initial_tsn, gfp))
2424 goto clean_up;
2425
2426 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
2427 *
2428 * The stream sequence number in all the streams shall start
2429 * from 0 when the association is established. Also, when the
2430 * stream sequence number reaches the value 65535 the next
2431 * stream sequence number shall be set to 0.
2432 */
2433
2434 /* Allocate storage for the negotiated streams if it is not a temporary
2435 * association.
2436 */
2437 if (!asoc->temp) {
2438 int error;
2439
2440 asoc->ssnmap = sctp_ssnmap_new(asoc->c.sinit_max_instreams,
2441 asoc->c.sinit_num_ostreams, gfp);
2442 if (!asoc->ssnmap)
2443 goto clean_up;
2444
2445 error = sctp_assoc_set_id(asoc, gfp);
2446 if (error)
2447 goto clean_up;
2448 }
2449
2450 /* ADDIP Section 4.1 ASCONF Chunk Procedures
2451 *
2452 * When an endpoint has an ASCONF signaled change to be sent to the
2453 * remote endpoint it should do the following:
2454 * ...
2455 * A2) A serial number should be assigned to the Chunk. The serial
2456 * number should be a monotonically increasing number. All serial
2457 * numbers are defined to be initialized at the start of the
2458 * association to the same value as the Initial TSN.
2459 */
2460 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1;
2461 return 1;
2462
2463 clean_up:
2464 /* Release the transport structures. */
2465 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
2466 transport = list_entry(pos, struct sctp_transport, transports);
2467 if (transport->state != SCTP_ACTIVE)
2468 sctp_assoc_rm_peer(asoc, transport);
2469 }
2470
2471 nomem:
2472 return 0;
2473 }
2474
2475
2476 /* Update asoc with the option described in param.
2477 *
2478 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT
2479 *
2480 * asoc is the association to update.
2481 * param is the variable length parameter to use for update.
2482 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO.
2483 * If the current packet is an INIT we want to minimize the amount of
2484 * work we do. In particular, we should not build transport
2485 * structures for the addresses.
2486 */
2487 static int sctp_process_param(struct sctp_association *asoc,
2488 union sctp_params param,
2489 const union sctp_addr *peer_addr,
2490 gfp_t gfp)
2491 {
2492 struct net *net = sock_net(asoc->base.sk);
2493 union sctp_addr addr;
2494 int i;
2495 __u16 sat;
2496 int retval = 1;
2497 sctp_scope_t scope;
2498 u32 stale;
2499 struct sctp_af *af;
2500 union sctp_addr_param *addr_param;
2501 struct sctp_transport *t;
2502 struct sctp_endpoint *ep = asoc->ep;
2503
2504 /* We maintain all INIT parameters in network byte order all the
2505 * time. This allows us to not worry about whether the parameters
2506 * came from a fresh INIT, and INIT ACK, or were stored in a cookie.
2507 */
2508 switch (param.p->type) {
2509 case SCTP_PARAM_IPV6_ADDRESS:
2510 if (PF_INET6 != asoc->base.sk->sk_family)
2511 break;
2512 goto do_addr_param;
2513
2514 case SCTP_PARAM_IPV4_ADDRESS:
2515 /* v4 addresses are not allowed on v6-only socket */
2516 if (ipv6_only_sock(asoc->base.sk))
2517 break;
2518 do_addr_param:
2519 af = sctp_get_af_specific(param_type2af(param.p->type));
2520 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0);
2521 scope = sctp_scope(peer_addr);
2522 if (sctp_in_scope(net, &addr, scope))
2523 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED))
2524 return 0;
2525 break;
2526
2527 case SCTP_PARAM_COOKIE_PRESERVATIVE:
2528 if (!net->sctp.cookie_preserve_enable)
2529 break;
2530
2531 stale = ntohl(param.life->lifespan_increment);
2532
2533 /* Suggested Cookie Life span increment's unit is msec,
2534 * (1/1000sec).
2535 */
2536 asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale);
2537 break;
2538
2539 case SCTP_PARAM_HOST_NAME_ADDRESS:
2540 pr_debug("%s: unimplemented SCTP_HOST_NAME_ADDRESS\n", __func__);
2541 break;
2542
2543 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
2544 /* Turn off the default values first so we'll know which
2545 * ones are really set by the peer.
2546 */
2547 asoc->peer.ipv4_address = 0;
2548 asoc->peer.ipv6_address = 0;
2549
2550 /* Assume that peer supports the address family
2551 * by which it sends a packet.
2552 */
2553 if (peer_addr->sa.sa_family == AF_INET6)
2554 asoc->peer.ipv6_address = 1;
2555 else if (peer_addr->sa.sa_family == AF_INET)
2556 asoc->peer.ipv4_address = 1;
2557
2558 /* Cycle through address types; avoid divide by 0. */
2559 sat = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
2560 if (sat)
2561 sat /= sizeof(__u16);
2562
2563 for (i = 0; i < sat; ++i) {
2564 switch (param.sat->types[i]) {
2565 case SCTP_PARAM_IPV4_ADDRESS:
2566 asoc->peer.ipv4_address = 1;
2567 break;
2568
2569 case SCTP_PARAM_IPV6_ADDRESS:
2570 if (PF_INET6 == asoc->base.sk->sk_family)
2571 asoc->peer.ipv6_address = 1;
2572 break;
2573
2574 case SCTP_PARAM_HOST_NAME_ADDRESS:
2575 asoc->peer.hostname_address = 1;
2576 break;
2577
2578 default: /* Just ignore anything else. */
2579 break;
2580 }
2581 }
2582 break;
2583
2584 case SCTP_PARAM_STATE_COOKIE:
2585 asoc->peer.cookie_len =
2586 ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
2587 asoc->peer.cookie = param.cookie->body;
2588 break;
2589
2590 case SCTP_PARAM_HEARTBEAT_INFO:
2591 /* Would be odd to receive, but it causes no problems. */
2592 break;
2593
2594 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
2595 /* Rejected during verify stage. */
2596 break;
2597
2598 case SCTP_PARAM_ECN_CAPABLE:
2599 asoc->peer.ecn_capable = 1;
2600 break;
2601
2602 case SCTP_PARAM_ADAPTATION_LAYER_IND:
2603 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind);
2604 break;
2605
2606 case SCTP_PARAM_SET_PRIMARY:
2607 if (!net->sctp.addip_enable)
2608 goto fall_through;
2609
2610 addr_param = param.v + sizeof(sctp_addip_param_t);
2611
2612 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
2613 if (af == NULL)
2614 break;
2615
2616 af->from_addr_param(&addr, addr_param,
2617 htons(asoc->peer.port), 0);
2618
2619 /* if the address is invalid, we can't process it.
2620 * XXX: see spec for what to do.
2621 */
2622 if (!af->addr_valid(&addr, NULL, NULL))
2623 break;
2624
2625 t = sctp_assoc_lookup_paddr(asoc, &addr);
2626 if (!t)
2627 break;
2628
2629 sctp_assoc_set_primary(asoc, t);
2630 break;
2631
2632 case SCTP_PARAM_SUPPORTED_EXT:
2633 sctp_process_ext_param(asoc, param);
2634 break;
2635
2636 case SCTP_PARAM_FWD_TSN_SUPPORT:
2637 if (net->sctp.prsctp_enable) {
2638 asoc->peer.prsctp_capable = 1;
2639 break;
2640 }
2641 /* Fall Through */
2642 goto fall_through;
2643
2644 case SCTP_PARAM_RANDOM:
2645 if (!ep->auth_enable)
2646 goto fall_through;
2647
2648 /* Save peer's random parameter */
2649 asoc->peer.peer_random = kmemdup(param.p,
2650 ntohs(param.p->length), gfp);
2651 if (!asoc->peer.peer_random) {
2652 retval = 0;
2653 break;
2654 }
2655 break;
2656
2657 case SCTP_PARAM_HMAC_ALGO:
2658 if (!ep->auth_enable)
2659 goto fall_through;
2660
2661 /* Save peer's HMAC list */
2662 asoc->peer.peer_hmacs = kmemdup(param.p,
2663 ntohs(param.p->length), gfp);
2664 if (!asoc->peer.peer_hmacs) {
2665 retval = 0;
2666 break;
2667 }
2668
2669 /* Set the default HMAC the peer requested*/
2670 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo);
2671 break;
2672
2673 case SCTP_PARAM_CHUNKS:
2674 if (!ep->auth_enable)
2675 goto fall_through;
2676
2677 asoc->peer.peer_chunks = kmemdup(param.p,
2678 ntohs(param.p->length), gfp);
2679 if (!asoc->peer.peer_chunks)
2680 retval = 0;
2681 break;
2682 fall_through:
2683 default:
2684 /* Any unrecognized parameters should have been caught
2685 * and handled by sctp_verify_param() which should be
2686 * called prior to this routine. Simply log the error
2687 * here.
2688 */
2689 pr_debug("%s: ignoring param:%d for association:%p.\n",
2690 __func__, ntohs(param.p->type), asoc);
2691 break;
2692 }
2693
2694 return retval;
2695 }
2696
2697 /* Select a new verification tag. */
2698 __u32 sctp_generate_tag(const struct sctp_endpoint *ep)
2699 {
2700 /* I believe that this random number generator complies with RFC1750.
2701 * A tag of 0 is reserved for special cases (e.g. INIT).
2702 */
2703 __u32 x;
2704
2705 do {
2706 get_random_bytes(&x, sizeof(__u32));
2707 } while (x == 0);
2708
2709 return x;
2710 }
2711
2712 /* Select an initial TSN to send during startup. */
2713 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep)
2714 {
2715 __u32 retval;
2716
2717 get_random_bytes(&retval, sizeof(__u32));
2718 return retval;
2719 }
2720
2721 /*
2722 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF)
2723 * 0 1 2 3
2724 * 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
2725 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2726 * | Type = 0xC1 | Chunk Flags | Chunk Length |
2727 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2728 * | Serial Number |
2729 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2730 * | Address Parameter |
2731 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2732 * | ASCONF Parameter #1 |
2733 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2734 * \ \
2735 * / .... /
2736 * \ \
2737 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2738 * | ASCONF Parameter #N |
2739 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2740 *
2741 * Address Parameter and other parameter will not be wrapped in this function
2742 */
2743 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc,
2744 union sctp_addr *addr,
2745 int vparam_len)
2746 {
2747 sctp_addiphdr_t asconf;
2748 struct sctp_chunk *retval;
2749 int length = sizeof(asconf) + vparam_len;
2750 union sctp_addr_param addrparam;
2751 int addrlen;
2752 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
2753
2754 addrlen = af->to_addr_param(addr, &addrparam);
2755 if (!addrlen)
2756 return NULL;
2757 length += addrlen;
2758
2759 /* Create the chunk. */
2760 retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length);
2761 if (!retval)
2762 return NULL;
2763
2764 asconf.serial = htonl(asoc->addip_serial++);
2765
2766 retval->subh.addip_hdr =
2767 sctp_addto_chunk(retval, sizeof(asconf), &asconf);
2768 retval->param_hdr.v =
2769 sctp_addto_chunk(retval, addrlen, &addrparam);
2770
2771 return retval;
2772 }
2773
2774 /* ADDIP
2775 * 3.2.1 Add IP Address
2776 * 0 1 2 3
2777 * 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
2778 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2779 * | Type = 0xC001 | Length = Variable |
2780 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2781 * | ASCONF-Request Correlation ID |
2782 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2783 * | Address Parameter |
2784 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2785 *
2786 * 3.2.2 Delete IP Address
2787 * 0 1 2 3
2788 * 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
2789 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2790 * | Type = 0xC002 | Length = Variable |
2791 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2792 * | ASCONF-Request Correlation ID |
2793 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2794 * | Address Parameter |
2795 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2796 *
2797 */
2798 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc,
2799 union sctp_addr *laddr,
2800 struct sockaddr *addrs,
2801 int addrcnt,
2802 __be16 flags)
2803 {
2804 sctp_addip_param_t param;
2805 struct sctp_chunk *retval;
2806 union sctp_addr_param addr_param;
2807 union sctp_addr *addr;
2808 void *addr_buf;
2809 struct sctp_af *af;
2810 int paramlen = sizeof(param);
2811 int addr_param_len = 0;
2812 int totallen = 0;
2813 int i;
2814 int del_pickup = 0;
2815
2816 /* Get total length of all the address parameters. */
2817 addr_buf = addrs;
2818 for (i = 0; i < addrcnt; i++) {
2819 addr = addr_buf;
2820 af = sctp_get_af_specific(addr->v4.sin_family);
2821 addr_param_len = af->to_addr_param(addr, &addr_param);
2822
2823 totallen += paramlen;
2824 totallen += addr_param_len;
2825
2826 addr_buf += af->sockaddr_len;
2827 if (asoc->asconf_addr_del_pending && !del_pickup) {
2828 /* reuse the parameter length from the same scope one */
2829 totallen += paramlen;
2830 totallen += addr_param_len;
2831 del_pickup = 1;
2832
2833 pr_debug("%s: picked same-scope del_pending addr, "
2834 "totallen for all addresses is %d\n",
2835 __func__, totallen);
2836 }
2837 }
2838
2839 /* Create an asconf chunk with the required length. */
2840 retval = sctp_make_asconf(asoc, laddr, totallen);
2841 if (!retval)
2842 return NULL;
2843
2844 /* Add the address parameters to the asconf chunk. */
2845 addr_buf = addrs;
2846 for (i = 0; i < addrcnt; i++) {
2847 addr = addr_buf;
2848 af = sctp_get_af_specific(addr->v4.sin_family);
2849 addr_param_len = af->to_addr_param(addr, &addr_param);
2850 param.param_hdr.type = flags;
2851 param.param_hdr.length = htons(paramlen + addr_param_len);
2852 param.crr_id = i;
2853
2854 sctp_addto_chunk(retval, paramlen, &param);
2855 sctp_addto_chunk(retval, addr_param_len, &addr_param);
2856
2857 addr_buf += af->sockaddr_len;
2858 }
2859 if (flags == SCTP_PARAM_ADD_IP && del_pickup) {
2860 addr = asoc->asconf_addr_del_pending;
2861 af = sctp_get_af_specific(addr->v4.sin_family);
2862 addr_param_len = af->to_addr_param(addr, &addr_param);
2863 param.param_hdr.type = SCTP_PARAM_DEL_IP;
2864 param.param_hdr.length = htons(paramlen + addr_param_len);
2865 param.crr_id = i;
2866
2867 sctp_addto_chunk(retval, paramlen, &param);
2868 sctp_addto_chunk(retval, addr_param_len, &addr_param);
2869 }
2870 return retval;
2871 }
2872
2873 /* ADDIP
2874 * 3.2.4 Set Primary IP Address
2875 * 0 1 2 3
2876 * 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
2877 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2878 * | Type =0xC004 | Length = Variable |
2879 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2880 * | ASCONF-Request Correlation ID |
2881 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2882 * | Address Parameter |
2883 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2884 *
2885 * Create an ASCONF chunk with Set Primary IP address parameter.
2886 */
2887 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
2888 union sctp_addr *addr)
2889 {
2890 sctp_addip_param_t param;
2891 struct sctp_chunk *retval;
2892 int len = sizeof(param);
2893 union sctp_addr_param addrparam;
2894 int addrlen;
2895 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
2896
2897 addrlen = af->to_addr_param(addr, &addrparam);
2898 if (!addrlen)
2899 return NULL;
2900 len += addrlen;
2901
2902 /* Create the chunk and make asconf header. */
2903 retval = sctp_make_asconf(asoc, addr, len);
2904 if (!retval)
2905 return NULL;
2906
2907 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY;
2908 param.param_hdr.length = htons(len);
2909 param.crr_id = 0;
2910
2911 sctp_addto_chunk(retval, sizeof(param), &param);
2912 sctp_addto_chunk(retval, addrlen, &addrparam);
2913
2914 return retval;
2915 }
2916
2917 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK)
2918 * 0 1 2 3
2919 * 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
2920 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2921 * | Type = 0x80 | Chunk Flags | Chunk Length |
2922 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2923 * | Serial Number |
2924 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2925 * | ASCONF Parameter Response#1 |
2926 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2927 * \ \
2928 * / .... /
2929 * \ \
2930 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2931 * | ASCONF Parameter Response#N |
2932 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2933 *
2934 * Create an ASCONF_ACK chunk with enough space for the parameter responses.
2935 */
2936 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc,
2937 __u32 serial, int vparam_len)
2938 {
2939 sctp_addiphdr_t asconf;
2940 struct sctp_chunk *retval;
2941 int length = sizeof(asconf) + vparam_len;
2942
2943 /* Create the chunk. */
2944 retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length);
2945 if (!retval)
2946 return NULL;
2947
2948 asconf.serial = htonl(serial);
2949
2950 retval->subh.addip_hdr =
2951 sctp_addto_chunk(retval, sizeof(asconf), &asconf);
2952
2953 return retval;
2954 }
2955
2956 /* Add response parameters to an ASCONF_ACK chunk. */
2957 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id,
2958 __be16 err_code, sctp_addip_param_t *asconf_param)
2959 {
2960 sctp_addip_param_t ack_param;
2961 sctp_errhdr_t err_param;
2962 int asconf_param_len = 0;
2963 int err_param_len = 0;
2964 __be16 response_type;
2965
2966 if (SCTP_ERROR_NO_ERROR == err_code) {
2967 response_type = SCTP_PARAM_SUCCESS_REPORT;
2968 } else {
2969 response_type = SCTP_PARAM_ERR_CAUSE;
2970 err_param_len = sizeof(err_param);
2971 if (asconf_param)
2972 asconf_param_len =
2973 ntohs(asconf_param->param_hdr.length);
2974 }
2975
2976 /* Add Success Indication or Error Cause Indication parameter. */
2977 ack_param.param_hdr.type = response_type;
2978 ack_param.param_hdr.length = htons(sizeof(ack_param) +
2979 err_param_len +
2980 asconf_param_len);
2981 ack_param.crr_id = crr_id;
2982 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param);
2983
2984 if (SCTP_ERROR_NO_ERROR == err_code)
2985 return;
2986
2987 /* Add Error Cause parameter. */
2988 err_param.cause = err_code;
2989 err_param.length = htons(err_param_len + asconf_param_len);
2990 sctp_addto_chunk(chunk, err_param_len, &err_param);
2991
2992 /* Add the failed TLV copied from ASCONF chunk. */
2993 if (asconf_param)
2994 sctp_addto_chunk(chunk, asconf_param_len, asconf_param);
2995 }
2996
2997 /* Process a asconf parameter. */
2998 static __be16 sctp_process_asconf_param(struct sctp_association *asoc,
2999 struct sctp_chunk *asconf,
3000 sctp_addip_param_t *asconf_param)
3001 {
3002 struct sctp_transport *peer;
3003 struct sctp_af *af;
3004 union sctp_addr addr;
3005 union sctp_addr_param *addr_param;
3006
3007 addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t);
3008
3009 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP &&
3010 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP &&
3011 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY)
3012 return SCTP_ERROR_UNKNOWN_PARAM;
3013
3014 switch (addr_param->p.type) {
3015 case SCTP_PARAM_IPV6_ADDRESS:
3016 if (!asoc->peer.ipv6_address)
3017 return SCTP_ERROR_DNS_FAILED;
3018 break;
3019 case SCTP_PARAM_IPV4_ADDRESS:
3020 if (!asoc->peer.ipv4_address)
3021 return SCTP_ERROR_DNS_FAILED;
3022 break;
3023 default:
3024 return SCTP_ERROR_DNS_FAILED;
3025 }
3026
3027 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
3028 if (unlikely(!af))
3029 return SCTP_ERROR_DNS_FAILED;
3030
3031 af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0);
3032
3033 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast
3034 * or multicast address.
3035 * (note: wildcard is permitted and requires special handling so
3036 * make sure we check for that)
3037 */
3038 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb))
3039 return SCTP_ERROR_DNS_FAILED;
3040
3041 switch (asconf_param->param_hdr.type) {
3042 case SCTP_PARAM_ADD_IP:
3043 /* Section 4.2.1:
3044 * If the address 0.0.0.0 or ::0 is provided, the source
3045 * address of the packet MUST be added.
3046 */
3047 if (af->is_any(&addr))
3048 memcpy(&addr, &asconf->source, sizeof(addr));
3049
3050 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address
3051 * request and does not have the local resources to add this
3052 * new address to the association, it MUST return an Error
3053 * Cause TLV set to the new error code 'Operation Refused
3054 * Due to Resource Shortage'.
3055 */
3056
3057 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED);
3058 if (!peer)
3059 return SCTP_ERROR_RSRC_LOW;
3060
3061 /* Start the heartbeat timer. */
3062 if (!mod_timer(&peer->hb_timer, sctp_transport_timeout(peer)))
3063 sctp_transport_hold(peer);
3064 asoc->new_transport = peer;
3065 break;
3066 case SCTP_PARAM_DEL_IP:
3067 /* ADDIP 4.3 D7) If a request is received to delete the
3068 * last remaining IP address of a peer endpoint, the receiver
3069 * MUST send an Error Cause TLV with the error cause set to the
3070 * new error code 'Request to Delete Last Remaining IP Address'.
3071 */
3072 if (asoc->peer.transport_count == 1)
3073 return SCTP_ERROR_DEL_LAST_IP;
3074
3075 /* ADDIP 4.3 D8) If a request is received to delete an IP
3076 * address which is also the source address of the IP packet
3077 * which contained the ASCONF chunk, the receiver MUST reject
3078 * this request. To reject the request the receiver MUST send
3079 * an Error Cause TLV set to the new error code 'Request to
3080 * Delete Source IP Address'
3081 */
3082 if (sctp_cmp_addr_exact(&asconf->source, &addr))
3083 return SCTP_ERROR_DEL_SRC_IP;
3084
3085 /* Section 4.2.2
3086 * If the address 0.0.0.0 or ::0 is provided, all
3087 * addresses of the peer except the source address of the
3088 * packet MUST be deleted.
3089 */
3090 if (af->is_any(&addr)) {
3091 sctp_assoc_set_primary(asoc, asconf->transport);
3092 sctp_assoc_del_nonprimary_peers(asoc,
3093 asconf->transport);
3094 return SCTP_ERROR_NO_ERROR;
3095 }
3096
3097 /* If the address is not part of the association, the
3098 * ASCONF-ACK with Error Cause Indication Parameter
3099 * which including cause of Unresolvable Address should
3100 * be sent.
3101 */
3102 peer = sctp_assoc_lookup_paddr(asoc, &addr);
3103 if (!peer)
3104 return SCTP_ERROR_DNS_FAILED;
3105
3106 sctp_assoc_rm_peer(asoc, peer);
3107 break;
3108 case SCTP_PARAM_SET_PRIMARY:
3109 /* ADDIP Section 4.2.4
3110 * If the address 0.0.0.0 or ::0 is provided, the receiver
3111 * MAY mark the source address of the packet as its
3112 * primary.
3113 */
3114 if (af->is_any(&addr))
3115 memcpy(&addr.v4, sctp_source(asconf), sizeof(addr));
3116
3117 peer = sctp_assoc_lookup_paddr(asoc, &addr);
3118 if (!peer)
3119 return SCTP_ERROR_DNS_FAILED;
3120
3121 sctp_assoc_set_primary(asoc, peer);
3122 break;
3123 }
3124
3125 return SCTP_ERROR_NO_ERROR;
3126 }
3127
3128 /* Verify the ASCONF packet before we process it. */
3129 bool sctp_verify_asconf(const struct sctp_association *asoc,
3130 struct sctp_chunk *chunk, bool addr_param_needed,
3131 struct sctp_paramhdr **errp)
3132 {
3133 sctp_addip_chunk_t *addip = (sctp_addip_chunk_t *) chunk->chunk_hdr;
3134 union sctp_params param;
3135 bool addr_param_seen = false;
3136
3137 sctp_walk_params(param, addip, addip_hdr.params) {
3138 size_t length = ntohs(param.p->length);
3139
3140 *errp = param.p;
3141 switch (param.p->type) {
3142 case SCTP_PARAM_ERR_CAUSE:
3143 break;
3144 case SCTP_PARAM_IPV4_ADDRESS:
3145 if (length != sizeof(sctp_ipv4addr_param_t))
3146 return false;
3147 /* ensure there is only one addr param and it's in the
3148 * beginning of addip_hdr params, or we reject it.
3149 */
3150 if (param.v != addip->addip_hdr.params)
3151 return false;
3152 addr_param_seen = true;
3153 break;
3154 case SCTP_PARAM_IPV6_ADDRESS:
3155 if (length != sizeof(sctp_ipv6addr_param_t))
3156 return false;
3157 if (param.v != addip->addip_hdr.params)
3158 return false;
3159 addr_param_seen = true;
3160 break;
3161 case SCTP_PARAM_ADD_IP:
3162 case SCTP_PARAM_DEL_IP:
3163 case SCTP_PARAM_SET_PRIMARY:
3164 /* In ASCONF chunks, these need to be first. */
3165 if (addr_param_needed && !addr_param_seen)
3166 return false;
3167 length = ntohs(param.addip->param_hdr.length);
3168 if (length < sizeof(sctp_addip_param_t) +
3169 sizeof(sctp_paramhdr_t))
3170 return false;
3171 break;
3172 case SCTP_PARAM_SUCCESS_REPORT:
3173 case SCTP_PARAM_ADAPTATION_LAYER_IND:
3174 if (length != sizeof(sctp_addip_param_t))
3175 return false;
3176 break;
3177 default:
3178 /* This is unkown to us, reject! */
3179 return false;
3180 }
3181 }
3182
3183 /* Remaining sanity checks. */
3184 if (addr_param_needed && !addr_param_seen)
3185 return false;
3186 if (!addr_param_needed && addr_param_seen)
3187 return false;
3188 if (param.v != chunk->chunk_end)
3189 return false;
3190
3191 return true;
3192 }
3193
3194 /* Process an incoming ASCONF chunk with the next expected serial no. and
3195 * return an ASCONF_ACK chunk to be sent in response.
3196 */
3197 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
3198 struct sctp_chunk *asconf)
3199 {
3200 sctp_addip_chunk_t *addip = (sctp_addip_chunk_t *) asconf->chunk_hdr;
3201 bool all_param_pass = true;
3202 union sctp_params param;
3203 sctp_addiphdr_t *hdr;
3204 union sctp_addr_param *addr_param;
3205 sctp_addip_param_t *asconf_param;
3206 struct sctp_chunk *asconf_ack;
3207 __be16 err_code;
3208 int length = 0;
3209 int chunk_len;
3210 __u32 serial;
3211
3212 chunk_len = ntohs(asconf->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
3213 hdr = (sctp_addiphdr_t *)asconf->skb->data;
3214 serial = ntohl(hdr->serial);
3215
3216 /* Skip the addiphdr and store a pointer to address parameter. */
3217 length = sizeof(sctp_addiphdr_t);
3218 addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
3219 chunk_len -= length;
3220
3221 /* Skip the address parameter and store a pointer to the first
3222 * asconf parameter.
3223 */
3224 length = ntohs(addr_param->p.length);
3225 asconf_param = (void *)addr_param + length;
3226 chunk_len -= length;
3227
3228 /* create an ASCONF_ACK chunk.
3229 * Based on the definitions of parameters, we know that the size of
3230 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF
3231 * parameters.
3232 */
3233 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4);
3234 if (!asconf_ack)
3235 goto done;
3236
3237 /* Process the TLVs contained within the ASCONF chunk. */
3238 sctp_walk_params(param, addip, addip_hdr.params) {
3239 /* Skip preceeding address parameters. */
3240 if (param.p->type == SCTP_PARAM_IPV4_ADDRESS ||
3241 param.p->type == SCTP_PARAM_IPV6_ADDRESS)
3242 continue;
3243
3244 err_code = sctp_process_asconf_param(asoc, asconf,
3245 param.addip);
3246 /* ADDIP 4.1 A7)
3247 * If an error response is received for a TLV parameter,
3248 * all TLVs with no response before the failed TLV are
3249 * considered successful if not reported. All TLVs after
3250 * the failed response are considered unsuccessful unless
3251 * a specific success indication is present for the parameter.
3252 */
3253 if (err_code != SCTP_ERROR_NO_ERROR)
3254 all_param_pass = false;
3255 if (!all_param_pass)
3256 sctp_add_asconf_response(asconf_ack, param.addip->crr_id,
3257 err_code, param.addip);
3258
3259 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add
3260 * an IP address sends an 'Out of Resource' in its response, it
3261 * MUST also fail any subsequent add or delete requests bundled
3262 * in the ASCONF.
3263 */
3264 if (err_code == SCTP_ERROR_RSRC_LOW)
3265 goto done;
3266 }
3267 done:
3268 asoc->peer.addip_serial++;
3269
3270 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc
3271 * after freeing the reference to old asconf ack if any.
3272 */
3273 if (asconf_ack) {
3274 sctp_chunk_hold(asconf_ack);
3275 list_add_tail(&asconf_ack->transmitted_list,
3276 &asoc->asconf_ack_list);
3277 }
3278
3279 return asconf_ack;
3280 }
3281
3282 /* Process a asconf parameter that is successfully acked. */
3283 static void sctp_asconf_param_success(struct sctp_association *asoc,
3284 sctp_addip_param_t *asconf_param)
3285 {
3286 struct sctp_af *af;
3287 union sctp_addr addr;
3288 struct sctp_bind_addr *bp = &asoc->base.bind_addr;
3289 union sctp_addr_param *addr_param;
3290 struct sctp_transport *transport;
3291 struct sctp_sockaddr_entry *saddr;
3292
3293 addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t);
3294
3295 /* We have checked the packet before, so we do not check again. */
3296 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
3297 af->from_addr_param(&addr, addr_param, htons(bp->port), 0);
3298
3299 switch (asconf_param->param_hdr.type) {
3300 case SCTP_PARAM_ADD_IP:
3301 /* This is always done in BH context with a socket lock
3302 * held, so the list can not change.
3303 */
3304 local_bh_disable();
3305 list_for_each_entry(saddr, &bp->address_list, list) {
3306 if (sctp_cmp_addr_exact(&saddr->a, &addr))
3307 saddr->state = SCTP_ADDR_SRC;
3308 }
3309 local_bh_enable();
3310 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
3311 transports) {
3312 dst_release(transport->dst);
3313 transport->dst = NULL;
3314 }
3315 break;
3316 case SCTP_PARAM_DEL_IP:
3317 local_bh_disable();
3318 sctp_del_bind_addr(bp, &addr);
3319 if (asoc->asconf_addr_del_pending != NULL &&
3320 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) {
3321 kfree(asoc->asconf_addr_del_pending);
3322 asoc->asconf_addr_del_pending = NULL;
3323 }
3324 local_bh_enable();
3325 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
3326 transports) {
3327 dst_release(transport->dst);
3328 transport->dst = NULL;
3329 }
3330 break;
3331 default:
3332 break;
3333 }
3334 }
3335
3336 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk
3337 * for the given asconf parameter. If there is no response for this parameter,
3338 * return the error code based on the third argument 'no_err'.
3339 * ADDIP 4.1
3340 * A7) If an error response is received for a TLV parameter, all TLVs with no
3341 * response before the failed TLV are considered successful if not reported.
3342 * All TLVs after the failed response are considered unsuccessful unless a
3343 * specific success indication is present for the parameter.
3344 */
3345 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack,
3346 sctp_addip_param_t *asconf_param,
3347 int no_err)
3348 {
3349 sctp_addip_param_t *asconf_ack_param;
3350 sctp_errhdr_t *err_param;
3351 int length;
3352 int asconf_ack_len;
3353 __be16 err_code;
3354
3355 if (no_err)
3356 err_code = SCTP_ERROR_NO_ERROR;
3357 else
3358 err_code = SCTP_ERROR_REQ_REFUSED;
3359
3360 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) -
3361 sizeof(sctp_chunkhdr_t);
3362
3363 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to
3364 * the first asconf_ack parameter.
3365 */
3366 length = sizeof(sctp_addiphdr_t);
3367 asconf_ack_param = (sctp_addip_param_t *)(asconf_ack->skb->data +
3368 length);
3369 asconf_ack_len -= length;
3370
3371 while (asconf_ack_len > 0) {
3372 if (asconf_ack_param->crr_id == asconf_param->crr_id) {
3373 switch (asconf_ack_param->param_hdr.type) {
3374 case SCTP_PARAM_SUCCESS_REPORT:
3375 return SCTP_ERROR_NO_ERROR;
3376 case SCTP_PARAM_ERR_CAUSE:
3377 length = sizeof(sctp_addip_param_t);
3378 err_param = (void *)asconf_ack_param + length;
3379 asconf_ack_len -= length;
3380 if (asconf_ack_len > 0)
3381 return err_param->cause;
3382 else
3383 return SCTP_ERROR_INV_PARAM;
3384 break;
3385 default:
3386 return SCTP_ERROR_INV_PARAM;
3387 }
3388 }
3389
3390 length = ntohs(asconf_ack_param->param_hdr.length);
3391 asconf_ack_param = (void *)asconf_ack_param + length;
3392 asconf_ack_len -= length;
3393 }
3394
3395 return err_code;
3396 }
3397
3398 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */
3399 int sctp_process_asconf_ack(struct sctp_association *asoc,
3400 struct sctp_chunk *asconf_ack)
3401 {
3402 struct sctp_chunk *asconf = asoc->addip_last_asconf;
3403 union sctp_addr_param *addr_param;
3404 sctp_addip_param_t *asconf_param;
3405 int length = 0;
3406 int asconf_len = asconf->skb->len;
3407 int all_param_pass = 0;
3408 int no_err = 1;
3409 int retval = 0;
3410 __be16 err_code = SCTP_ERROR_NO_ERROR;
3411
3412 /* Skip the chunkhdr and addiphdr from the last asconf sent and store
3413 * a pointer to address parameter.
3414 */
3415 length = sizeof(sctp_addip_chunk_t);
3416 addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
3417 asconf_len -= length;
3418
3419 /* Skip the address parameter in the last asconf sent and store a
3420 * pointer to the first asconf parameter.
3421 */
3422 length = ntohs(addr_param->p.length);
3423 asconf_param = (void *)addr_param + length;
3424 asconf_len -= length;
3425
3426 /* ADDIP 4.1
3427 * A8) If there is no response(s) to specific TLV parameter(s), and no
3428 * failures are indicated, then all request(s) are considered
3429 * successful.
3430 */
3431 if (asconf_ack->skb->len == sizeof(sctp_addiphdr_t))
3432 all_param_pass = 1;
3433
3434 /* Process the TLVs contained in the last sent ASCONF chunk. */
3435 while (asconf_len > 0) {
3436 if (all_param_pass)
3437 err_code = SCTP_ERROR_NO_ERROR;
3438 else {
3439 err_code = sctp_get_asconf_response(asconf_ack,
3440 asconf_param,
3441 no_err);
3442 if (no_err && (SCTP_ERROR_NO_ERROR != err_code))
3443 no_err = 0;
3444 }
3445
3446 switch (err_code) {
3447 case SCTP_ERROR_NO_ERROR:
3448 sctp_asconf_param_success(asoc, asconf_param);
3449 break;
3450
3451 case SCTP_ERROR_RSRC_LOW:
3452 retval = 1;
3453 break;
3454
3455 case SCTP_ERROR_UNKNOWN_PARAM:
3456 /* Disable sending this type of asconf parameter in
3457 * future.
3458 */
3459 asoc->peer.addip_disabled_mask |=
3460 asconf_param->param_hdr.type;
3461 break;
3462
3463 case SCTP_ERROR_REQ_REFUSED:
3464 case SCTP_ERROR_DEL_LAST_IP:
3465 case SCTP_ERROR_DEL_SRC_IP:
3466 default:
3467 break;
3468 }
3469
3470 /* Skip the processed asconf parameter and move to the next
3471 * one.
3472 */
3473 length = ntohs(asconf_param->param_hdr.length);
3474 asconf_param = (void *)asconf_param + length;
3475 asconf_len -= length;
3476 }
3477
3478 if (no_err && asoc->src_out_of_asoc_ok) {
3479 asoc->src_out_of_asoc_ok = 0;
3480 sctp_transport_immediate_rtx(asoc->peer.primary_path);
3481 }
3482
3483 /* Free the cached last sent asconf chunk. */
3484 list_del_init(&asconf->transmitted_list);
3485 sctp_chunk_free(asconf);
3486 asoc->addip_last_asconf = NULL;
3487
3488 return retval;
3489 }
3490
3491 /* Make a FWD TSN chunk. */
3492 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
3493 __u32 new_cum_tsn, size_t nstreams,
3494 struct sctp_fwdtsn_skip *skiplist)
3495 {
3496 struct sctp_chunk *retval = NULL;
3497 struct sctp_fwdtsn_hdr ftsn_hdr;
3498 struct sctp_fwdtsn_skip skip;
3499 size_t hint;
3500 int i;
3501
3502 hint = (nstreams + 1) * sizeof(__u32);
3503
3504 retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint);
3505
3506 if (!retval)
3507 return NULL;
3508
3509 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn);
3510 retval->subh.fwdtsn_hdr =
3511 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr);
3512
3513 for (i = 0; i < nstreams; i++) {
3514 skip.stream = skiplist[i].stream;
3515 skip.ssn = skiplist[i].ssn;
3516 sctp_addto_chunk(retval, sizeof(skip), &skip);
3517 }
3518
3519 return retval;
3520 }
Linux with added FPC-III support