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Committer: Michael Beasley <mike@snafu.setup>
[mikesnafu-overlay.git] / net / sctp / sm_make_chunk.c
blob36ebb392472e3b1ae3ef4be91cda23db8b46548b
1 /* SCTP kernel implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999-2000 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 * Copyright (c) 2001-2002 Intel Corp.
6 *
7 * This file is part of the SCTP kernel implementation
8 *
9 * These functions work with the state functions in sctp_sm_statefuns.c
10 * to implement the state operations. These functions implement the
11 * steps which require modifying existing data structures.
12 *
13 * This SCTP implementation is free software;
14 * you can redistribute it and/or modify it under the terms of
15 * the GNU General Public License as published by
16 * the Free Software Foundation; either version 2, or (at your option)
17 * any later version.
18 *
19 * This SCTP implementation is distributed in the hope that it
20 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
21 * ************************
22 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
23 * See the GNU General Public License for more details.
24 *
25 * You should have received a copy of the GNU General Public License
26 * along with GNU CC; see the file COPYING. If not, write to
27 * the Free Software Foundation, 59 Temple Place - Suite 330,
28 * Boston, MA 02111-1307, USA.
29 *
30 * Please send any bug reports or fixes you make to the
31 * email address(es):
32 * lksctp developers <lksctp-developers@lists.sourceforge.net>
33 *
34 * Or submit a bug report through the following website:
35 * http://www.sf.net/projects/lksctp
36 *
37 * Written or modified by:
38 * La Monte H.P. Yarroll <piggy@acm.org>
39 * Karl Knutson <karl@athena.chicago.il.us>
40 * C. Robin <chris@hundredacre.ac.uk>
41 * Jon Grimm <jgrimm@us.ibm.com>
42 * Xingang Guo <xingang.guo@intel.com>
43 * Dajiang Zhang <dajiang.zhang@nokia.com>
44 * Sridhar Samudrala <sri@us.ibm.com>
45 * Daisy Chang <daisyc@us.ibm.com>
46 * Ardelle Fan <ardelle.fan@intel.com>
47 * Kevin Gao <kevin.gao@intel.com>
48 *
49 * Any bugs reported given to us we will try to fix... any fixes shared will
50 * be incorporated into the next SCTP release.
51 */
52
53 #include <linux/types.h>
54 #include <linux/kernel.h>
55 #include <linux/ip.h>
56 #include <linux/ipv6.h>
57 #include <linux/net.h>
58 #include <linux/inet.h>
59 #include <linux/scatterlist.h>
60 #include <linux/crypto.h>
61 #include <net/sock.h>
62
63 #include <linux/skbuff.h>
64 #include <linux/random.h> /* for get_random_bytes */
65 #include <net/sctp/sctp.h>
66 #include <net/sctp/sm.h>
67
68 SCTP_STATIC
69 struct sctp_chunk *sctp_make_chunk(const struct sctp_association *asoc,
70 __u8 type, __u8 flags, int paylen);
71 static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep,
72 const struct sctp_association *asoc,
73 const struct sctp_chunk *init_chunk,
74 int *cookie_len,
75 const __u8 *raw_addrs, int addrs_len);
76 static int sctp_process_param(struct sctp_association *asoc,
77 union sctp_params param,
78 const union sctp_addr *peer_addr,
79 gfp_t gfp);
80 static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
81 const void *data);
82
83 /* What was the inbound interface for this chunk? */
84 int sctp_chunk_iif(const struct sctp_chunk *chunk)
85 {
86 struct sctp_af *af;
87 int iif = 0;
88
89 af = sctp_get_af_specific(ipver2af(ip_hdr(chunk->skb)->version));
90 if (af)
91 iif = af->skb_iif(chunk->skb);
92
93 return iif;
94 }
95
96 /* RFC 2960 3.3.2 Initiation (INIT) (1)
97 *
98 * Note 2: The ECN capable field is reserved for future use of
99 * Explicit Congestion Notification.
100 */
101 static const struct sctp_paramhdr ecap_param = {
102 SCTP_PARAM_ECN_CAPABLE,
103 __constant_htons(sizeof(struct sctp_paramhdr)),
104 };
105 static const struct sctp_paramhdr prsctp_param = {
106 SCTP_PARAM_FWD_TSN_SUPPORT,
107 __constant_htons(sizeof(struct sctp_paramhdr)),
108 };
109
110 /* A helper to initialize to initialize an op error inside a
111 * provided chunk, as most cause codes will be embedded inside an
112 * abort chunk.
113 */
114 void sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code,
115 size_t paylen)
116 {
117 sctp_errhdr_t err;
118 __u16 len;
119
120 /* Cause code constants are now defined in network order. */
121 err.cause = cause_code;
122 len = sizeof(sctp_errhdr_t) + paylen;
123 err.length = htons(len);
124 chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(sctp_errhdr_t), &err);
125 }
126
127 /* 3.3.2 Initiation (INIT) (1)
128 *
129 * This chunk is used to initiate a SCTP association between two
130 * endpoints. The format of the INIT chunk is shown below:
131 *
132 * 0 1 2 3
133 * 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
134 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
135 * | Type = 1 | Chunk Flags | Chunk Length |
136 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
137 * | Initiate Tag |
138 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
139 * | Advertised Receiver Window Credit (a_rwnd) |
140 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
141 * | Number of Outbound Streams | Number of Inbound Streams |
142 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
143 * | Initial TSN |
144 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
145 * \ \
146 * / Optional/Variable-Length Parameters /
147 * \ \
148 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
149 *
150 *
151 * The INIT chunk contains the following parameters. Unless otherwise
152 * noted, each parameter MUST only be included once in the INIT chunk.
153 *
154 * Fixed Parameters Status
155 * ----------------------------------------------
156 * Initiate Tag Mandatory
157 * Advertised Receiver Window Credit Mandatory
158 * Number of Outbound Streams Mandatory
159 * Number of Inbound Streams Mandatory
160 * Initial TSN Mandatory
161 *
162 * Variable Parameters Status Type Value
163 * -------------------------------------------------------------
164 * IPv4 Address (Note 1) Optional 5
165 * IPv6 Address (Note 1) Optional 6
166 * Cookie Preservative Optional 9
167 * Reserved for ECN Capable (Note 2) Optional 32768 (0x8000)
168 * Host Name Address (Note 3) Optional 11
169 * Supported Address Types (Note 4) Optional 12
170 */
171 struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc,
172 const struct sctp_bind_addr *bp,
173 gfp_t gfp, int vparam_len)
174 {
175 sctp_inithdr_t init;
176 union sctp_params addrs;
177 size_t chunksize;
178 struct sctp_chunk *retval = NULL;
179 int num_types, addrs_len = 0;
180 struct sctp_sock *sp;
181 sctp_supported_addrs_param_t sat;
182 __be16 types[2];
183 sctp_adaptation_ind_param_t aiparam;
184 sctp_supported_ext_param_t ext_param;
185 int num_ext = 0;
186 __u8 extensions[3];
187 sctp_paramhdr_t *auth_chunks = NULL,
188 *auth_hmacs = NULL;
189
190 /* RFC 2960 3.3.2 Initiation (INIT) (1)
191 *
192 * Note 1: The INIT chunks can contain multiple addresses that
193 * can be IPv4 and/or IPv6 in any combination.
194 */
195 retval = NULL;
196
197 /* Convert the provided bind address list to raw format. */
198 addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp);
199
200 init.init_tag = htonl(asoc->c.my_vtag);
201 init.a_rwnd = htonl(asoc->rwnd);
202 init.num_outbound_streams = htons(asoc->c.sinit_num_ostreams);
203 init.num_inbound_streams = htons(asoc->c.sinit_max_instreams);
204 init.initial_tsn = htonl(asoc->c.initial_tsn);
205
206 /* How many address types are needed? */
207 sp = sctp_sk(asoc->base.sk);
208 num_types = sp->pf->supported_addrs(sp, types);
209
210 chunksize = sizeof(init) + addrs_len + SCTP_SAT_LEN(num_types);
211 chunksize += sizeof(ecap_param);
212
213 if (sctp_prsctp_enable)
214 chunksize += sizeof(prsctp_param);
215
216 /* ADDIP: Section 4.2.7:
217 * An implementation supporting this extension [ADDIP] MUST list
218 * the ASCONF,the ASCONF-ACK, and the AUTH chunks in its INIT and
219 * INIT-ACK parameters.
220 */
221 if (sctp_addip_enable) {
222 extensions[num_ext] = SCTP_CID_ASCONF;
223 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
224 num_ext += 2;
225 }
226
227 chunksize += sizeof(aiparam);
228 chunksize += vparam_len;
229
230 /* Account for AUTH related parameters */
231 if (sctp_auth_enable) {
232 /* Add random parameter length*/
233 chunksize += sizeof(asoc->c.auth_random);
234
235 /* Add HMACS parameter length if any were defined */
236 auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs;
237 if (auth_hmacs->length)
238 chunksize += ntohs(auth_hmacs->length);
239 else
240 auth_hmacs = NULL;
241
242 /* Add CHUNKS parameter length */
243 auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks;
244 if (auth_chunks->length)
245 chunksize += ntohs(auth_chunks->length);
246 else
247 auth_chunks = NULL;
248
249 extensions[num_ext] = SCTP_CID_AUTH;
250 num_ext += 1;
251 }
252
253 /* If we have any extensions to report, account for that */
254 if (num_ext)
255 chunksize += sizeof(sctp_supported_ext_param_t) + num_ext;
256
257 /* RFC 2960 3.3.2 Initiation (INIT) (1)
258 *
259 * Note 3: An INIT chunk MUST NOT contain more than one Host
260 * Name address parameter. Moreover, the sender of the INIT
261 * MUST NOT combine any other address types with the Host Name
262 * address in the INIT. The receiver of INIT MUST ignore any
263 * other address types if the Host Name address parameter is
264 * present in the received INIT chunk.
265 *
266 * PLEASE DO NOT FIXME [This version does not support Host Name.]
267 */
268
269 retval = sctp_make_chunk(asoc, SCTP_CID_INIT, 0, chunksize);
270 if (!retval)
271 goto nodata;
272
273 retval->subh.init_hdr =
274 sctp_addto_chunk(retval, sizeof(init), &init);
275 retval->param_hdr.v =
276 sctp_addto_chunk(retval, addrs_len, addrs.v);
277
278 /* RFC 2960 3.3.2 Initiation (INIT) (1)
279 *
280 * Note 4: This parameter, when present, specifies all the
281 * address types the sending endpoint can support. The absence
282 * of this parameter indicates that the sending endpoint can
283 * support any address type.
284 */
285 sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES;
286 sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types));
287 sctp_addto_chunk(retval, sizeof(sat), &sat);
288 sctp_addto_chunk(retval, num_types * sizeof(__u16), &types);
289
290 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
291
292 /* Add the supported extensions parameter. Be nice and add this
293 * fist before addiding the parameters for the extensions themselves
294 */
295 if (num_ext) {
296 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
297 ext_param.param_hdr.length =
298 htons(sizeof(sctp_supported_ext_param_t) + num_ext);
299 sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t),
300 &ext_param);
301 sctp_addto_param(retval, num_ext, extensions);
302 }
303
304 if (sctp_prsctp_enable)
305 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
306
307 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
308 aiparam.param_hdr.length = htons(sizeof(aiparam));
309 aiparam.adaptation_ind = htonl(sp->adaptation_ind);
310 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
311
312 /* Add SCTP-AUTH chunks to the parameter list */
313 if (sctp_auth_enable) {
314 sctp_addto_chunk(retval, sizeof(asoc->c.auth_random),
315 asoc->c.auth_random);
316 if (auth_hmacs)
317 sctp_addto_chunk(retval, ntohs(auth_hmacs->length),
318 auth_hmacs);
319 if (auth_chunks)
320 sctp_addto_chunk(retval, ntohs(auth_chunks->length),
321 auth_chunks);
322 }
323 nodata:
324 kfree(addrs.v);
325 return retval;
326 }
327
328 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc,
329 const struct sctp_chunk *chunk,
330 gfp_t gfp, int unkparam_len)
331 {
332 sctp_inithdr_t initack;
333 struct sctp_chunk *retval;
334 union sctp_params addrs;
335 int addrs_len;
336 sctp_cookie_param_t *cookie;
337 int cookie_len;
338 size_t chunksize;
339 sctp_adaptation_ind_param_t aiparam;
340 sctp_supported_ext_param_t ext_param;
341 int num_ext = 0;
342 __u8 extensions[3];
343 sctp_paramhdr_t *auth_chunks = NULL,
344 *auth_hmacs = NULL,
345 *auth_random = NULL;
346
347 retval = NULL;
348
349 /* Note: there may be no addresses to embed. */
350 addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp);
351
352 initack.init_tag = htonl(asoc->c.my_vtag);
353 initack.a_rwnd = htonl(asoc->rwnd);
354 initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams);
355 initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams);
356 initack.initial_tsn = htonl(asoc->c.initial_tsn);
357
358 /* FIXME: We really ought to build the cookie right
359 * into the packet instead of allocating more fresh memory.
360 */
361 cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len,
362 addrs.v, addrs_len);
363 if (!cookie)
364 goto nomem_cookie;
365
366 /* Calculate the total size of allocation, include the reserved
367 * space for reporting unknown parameters if it is specified.
368 */
369 chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len;
370
371 /* Tell peer that we'll do ECN only if peer advertised such cap. */
372 if (asoc->peer.ecn_capable)
373 chunksize += sizeof(ecap_param);
374
375 if (sctp_prsctp_enable)
376 chunksize += sizeof(prsctp_param);
377
378 if (sctp_addip_enable) {
379 extensions[num_ext] = SCTP_CID_ASCONF;
380 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
381 num_ext += 2;
382 }
383
384 chunksize += sizeof(aiparam);
385
386 if (asoc->peer.auth_capable) {
387 auth_random = (sctp_paramhdr_t *)asoc->c.auth_random;
388 chunksize += ntohs(auth_random->length);
389
390 auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs;
391 if (auth_hmacs->length)
392 chunksize += ntohs(auth_hmacs->length);
393 else
394 auth_hmacs = NULL;
395
396 auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks;
397 if (auth_chunks->length)
398 chunksize += ntohs(auth_chunks->length);
399 else
400 auth_chunks = NULL;
401
402 extensions[num_ext] = SCTP_CID_AUTH;
403 num_ext += 1;
404 }
405
406 if (num_ext)
407 chunksize += sizeof(sctp_supported_ext_param_t) + num_ext;
408
409 /* Now allocate and fill out the chunk. */
410 retval = sctp_make_chunk(asoc, SCTP_CID_INIT_ACK, 0, chunksize);
411 if (!retval)
412 goto nomem_chunk;
413
414 /* Per the advice in RFC 2960 6.4, send this reply to
415 * the source of the INIT packet.
416 */
417 retval->transport = chunk->transport;
418 retval->subh.init_hdr =
419 sctp_addto_chunk(retval, sizeof(initack), &initack);
420 retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v);
421 sctp_addto_chunk(retval, cookie_len, cookie);
422 if (asoc->peer.ecn_capable)
423 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
424 if (num_ext) {
425 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
426 ext_param.param_hdr.length =
427 htons(sizeof(sctp_supported_ext_param_t) + num_ext);
428 sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t),
429 &ext_param);
430 sctp_addto_param(retval, num_ext, extensions);
431 }
432 if (asoc->peer.prsctp_capable)
433 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
434
435 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
436 aiparam.param_hdr.length = htons(sizeof(aiparam));
437 aiparam.adaptation_ind = htonl(sctp_sk(asoc->base.sk)->adaptation_ind);
438 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
439
440 if (asoc->peer.auth_capable) {
441 sctp_addto_chunk(retval, ntohs(auth_random->length),
442 auth_random);
443 if (auth_hmacs)
444 sctp_addto_chunk(retval, ntohs(auth_hmacs->length),
445 auth_hmacs);
446 if (auth_chunks)
447 sctp_addto_chunk(retval, ntohs(auth_chunks->length),
448 auth_chunks);
449 }
450
451 /* We need to remove the const qualifier at this point. */
452 retval->asoc = (struct sctp_association *) asoc;
453
454 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
455 *
456 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
457 * HEARTBEAT ACK, * etc.) to the same destination transport
458 * address from which it received the DATA or control chunk
459 * to which it is replying.
460 *
461 * [INIT ACK back to where the INIT came from.]
462 */
463 if (chunk)
464 retval->transport = chunk->transport;
465
466 nomem_chunk:
467 kfree(cookie);
468 nomem_cookie:
469 kfree(addrs.v);
470 return retval;
471 }
472
473 /* 3.3.11 Cookie Echo (COOKIE ECHO) (10):
474 *
475 * This chunk is used only during the initialization of an association.
476 * It is sent by the initiator of an association to its peer to complete
477 * the initialization process. This chunk MUST precede any DATA chunk
478 * sent within the association, but MAY be bundled with one or more DATA
479 * chunks in the same packet.
480 *
481 * 0 1 2 3
482 * 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
483 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
484 * | Type = 10 |Chunk Flags | Length |
485 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
486 * / Cookie /
487 * \ \
488 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
489 *
490 * Chunk Flags: 8 bit
491 *
492 * Set to zero on transmit and ignored on receipt.
493 *
494 * Length: 16 bits (unsigned integer)
495 *
496 * Set to the size of the chunk in bytes, including the 4 bytes of
497 * the chunk header and the size of the Cookie.
498 *
499 * Cookie: variable size
500 *
501 * This field must contain the exact cookie received in the
502 * State Cookie parameter from the previous INIT ACK.
503 *
504 * An implementation SHOULD make the cookie as small as possible
505 * to insure interoperability.
506 */
507 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc,
508 const struct sctp_chunk *chunk)
509 {
510 struct sctp_chunk *retval;
511 void *cookie;
512 int cookie_len;
513
514 cookie = asoc->peer.cookie;
515 cookie_len = asoc->peer.cookie_len;
516
517 /* Build a cookie echo chunk. */
518 retval = sctp_make_chunk(asoc, SCTP_CID_COOKIE_ECHO, 0, cookie_len);
519 if (!retval)
520 goto nodata;
521 retval->subh.cookie_hdr =
522 sctp_addto_chunk(retval, cookie_len, cookie);
523
524 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
525 *
526 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
527 * HEARTBEAT ACK, * etc.) to the same destination transport
528 * address from which it * received the DATA or control chunk
529 * to which it is replying.
530 *
531 * [COOKIE ECHO back to where the INIT ACK came from.]
532 */
533 if (chunk)
534 retval->transport = chunk->transport;
535
536 nodata:
537 return retval;
538 }
539
540 /* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11):
541 *
542 * This chunk is used only during the initialization of an
543 * association. It is used to acknowledge the receipt of a COOKIE
544 * ECHO chunk. This chunk MUST precede any DATA or SACK chunk sent
545 * within the association, but MAY be bundled with one or more DATA
546 * chunks or SACK chunk in the same SCTP packet.
547 *
548 * 0 1 2 3
549 * 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
550 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
551 * | Type = 11 |Chunk Flags | Length = 4 |
552 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
553 *
554 * Chunk Flags: 8 bits
555 *
556 * Set to zero on transmit and ignored on receipt.
557 */
558 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc,
559 const struct sctp_chunk *chunk)
560 {
561 struct sctp_chunk *retval;
562
563 retval = sctp_make_chunk(asoc, SCTP_CID_COOKIE_ACK, 0, 0);
564
565 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
566 *
567 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
568 * HEARTBEAT ACK, * etc.) to the same destination transport
569 * address from which it * received the DATA or control chunk
570 * to which it is replying.
571 *
572 * [COOKIE ACK back to where the COOKIE ECHO came from.]
573 */
574 if (retval && chunk)
575 retval->transport = chunk->transport;
576
577 return retval;
578 }
579
580 /*
581 * Appendix A: Explicit Congestion Notification:
582 * CWR:
583 *
584 * RFC 2481 details a specific bit for a sender to send in the header of
585 * its next outbound TCP segment to indicate to its peer that it has
586 * reduced its congestion window. This is termed the CWR bit. For
587 * SCTP the same indication is made by including the CWR chunk.
588 * This chunk contains one data element, i.e. the TSN number that
589 * was sent in the ECNE chunk. This element represents the lowest
590 * TSN number in the datagram that was originally marked with the
591 * CE bit.
592 *
593 * 0 1 2 3
594 * 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
595 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
596 * | Chunk Type=13 | Flags=00000000| Chunk Length = 8 |
597 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
598 * | Lowest TSN Number |
599 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
600 *
601 * Note: The CWR is considered a Control chunk.
602 */
603 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc,
604 const __u32 lowest_tsn,
605 const struct sctp_chunk *chunk)
606 {
607 struct sctp_chunk *retval;
608 sctp_cwrhdr_t cwr;
609
610 cwr.lowest_tsn = htonl(lowest_tsn);
611 retval = sctp_make_chunk(asoc, SCTP_CID_ECN_CWR, 0,
612 sizeof(sctp_cwrhdr_t));
613
614 if (!retval)
615 goto nodata;
616
617 retval->subh.ecn_cwr_hdr =
618 sctp_addto_chunk(retval, sizeof(cwr), &cwr);
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 * [Report a reduced congestion window back to where the ECNE
628 * came from.]
629 */
630 if (chunk)
631 retval->transport = chunk->transport;
632
633 nodata:
634 return retval;
635 }
636
637 /* Make an ECNE chunk. This is a congestion experienced report. */
638 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc,
639 const __u32 lowest_tsn)
640 {
641 struct sctp_chunk *retval;
642 sctp_ecnehdr_t ecne;
643
644 ecne.lowest_tsn = htonl(lowest_tsn);
645 retval = sctp_make_chunk(asoc, SCTP_CID_ECN_ECNE, 0,
646 sizeof(sctp_ecnehdr_t));
647 if (!retval)
648 goto nodata;
649 retval->subh.ecne_hdr =
650 sctp_addto_chunk(retval, sizeof(ecne), &ecne);
651
652 nodata:
653 return retval;
654 }
655
656 /* Make a DATA chunk for the given association from the provided
657 * parameters. However, do not populate the data payload.
658 */
659 struct sctp_chunk *sctp_make_datafrag_empty(struct sctp_association *asoc,
660 const struct sctp_sndrcvinfo *sinfo,
661 int data_len, __u8 flags, __u16 ssn)
662 {
663 struct sctp_chunk *retval;
664 struct sctp_datahdr dp;
665 int chunk_len;
666
667 /* We assign the TSN as LATE as possible, not here when
668 * creating the chunk.
669 */
670 dp.tsn = 0;
671 dp.stream = htons(sinfo->sinfo_stream);
672 dp.ppid = sinfo->sinfo_ppid;
673
674 /* Set the flags for an unordered send. */
675 if (sinfo->sinfo_flags & SCTP_UNORDERED) {
676 flags |= SCTP_DATA_UNORDERED;
677 dp.ssn = 0;
678 } else
679 dp.ssn = htons(ssn);
680
681 chunk_len = sizeof(dp) + data_len;
682 retval = sctp_make_chunk(asoc, SCTP_CID_DATA, flags, chunk_len);
683 if (!retval)
684 goto nodata;
685
686 retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp);
687 memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo));
688
689 nodata:
690 return retval;
691 }
692
693 /* Create a selective ackowledgement (SACK) for the given
694 * association. This reports on which TSN's we've seen to date,
695 * including duplicates and gaps.
696 */
697 struct sctp_chunk *sctp_make_sack(const struct sctp_association *asoc)
698 {
699 struct sctp_chunk *retval;
700 struct sctp_sackhdr sack;
701 int len;
702 __u32 ctsn;
703 __u16 num_gabs, num_dup_tsns;
704 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
705
706 ctsn = sctp_tsnmap_get_ctsn(map);
707 SCTP_DEBUG_PRINTK("sackCTSNAck sent: 0x%x.\n", ctsn);
708
709 /* How much room is needed in the chunk? */
710 num_gabs = sctp_tsnmap_num_gabs(map);
711 num_dup_tsns = sctp_tsnmap_num_dups(map);
712
713 /* Initialize the SACK header. */
714 sack.cum_tsn_ack = htonl(ctsn);
715 sack.a_rwnd = htonl(asoc->a_rwnd);
716 sack.num_gap_ack_blocks = htons(num_gabs);
717 sack.num_dup_tsns = htons(num_dup_tsns);
718
719 len = sizeof(sack)
720 + sizeof(struct sctp_gap_ack_block) * num_gabs
721 + sizeof(__u32) * num_dup_tsns;
722
723 /* Create the chunk. */
724 retval = sctp_make_chunk(asoc, SCTP_CID_SACK, 0, len);
725 if (!retval)
726 goto nodata;
727
728 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
729 *
730 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
731 * HEARTBEAT ACK, etc.) to the same destination transport
732 * address from which it received the DATA or control chunk to
733 * which it is replying. This rule should also be followed if
734 * the endpoint is bundling DATA chunks together with the
735 * reply chunk.
736 *
737 * However, when acknowledging multiple DATA chunks received
738 * in packets from different source addresses in a single
739 * SACK, the SACK chunk may be transmitted to one of the
740 * destination transport addresses from which the DATA or
741 * control chunks being acknowledged were received.
742 *
743 * [BUG: We do not implement the following paragraph.
744 * Perhaps we should remember the last transport we used for a
745 * SACK and avoid that (if possible) if we have seen any
746 * duplicates. --piggy]
747 *
748 * When a receiver of a duplicate DATA chunk sends a SACK to a
749 * multi- homed endpoint it MAY be beneficial to vary the
750 * destination address and not use the source address of the
751 * DATA chunk. The reason being that receiving a duplicate
752 * from a multi-homed endpoint might indicate that the return
753 * path (as specified in the source address of the DATA chunk)
754 * for the SACK is broken.
755 *
756 * [Send to the address from which we last received a DATA chunk.]
757 */
758 retval->transport = asoc->peer.last_data_from;
759
760 retval->subh.sack_hdr =
761 sctp_addto_chunk(retval, sizeof(sack), &sack);
762
763 /* Add the gap ack block information. */
764 if (num_gabs)
765 sctp_addto_chunk(retval, sizeof(__u32) * num_gabs,
766 sctp_tsnmap_get_gabs(map));
767
768 /* Add the duplicate TSN information. */
769 if (num_dup_tsns)
770 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns,
771 sctp_tsnmap_get_dups(map));
772
773 nodata:
774 return retval;
775 }
776
777 /* Make a SHUTDOWN chunk. */
778 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc,
779 const struct sctp_chunk *chunk)
780 {
781 struct sctp_chunk *retval;
782 sctp_shutdownhdr_t shut;
783 __u32 ctsn;
784
785 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
786 shut.cum_tsn_ack = htonl(ctsn);
787
788 retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN, 0,
789 sizeof(sctp_shutdownhdr_t));
790 if (!retval)
791 goto nodata;
792
793 retval->subh.shutdown_hdr =
794 sctp_addto_chunk(retval, sizeof(shut), &shut);
795
796 if (chunk)
797 retval->transport = chunk->transport;
798 nodata:
799 return retval;
800 }
801
802 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc,
803 const struct sctp_chunk *chunk)
804 {
805 struct sctp_chunk *retval;
806
807 retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0);
808
809 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
810 *
811 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
812 * HEARTBEAT ACK, * etc.) to the same destination transport
813 * address from which it * received the DATA or control chunk
814 * to which it is replying.
815 *
816 * [ACK back to where the SHUTDOWN came from.]
817 */
818 if (retval && chunk)
819 retval->transport = chunk->transport;
820
821 return retval;
822 }
823
824 struct sctp_chunk *sctp_make_shutdown_complete(
825 const struct sctp_association *asoc,
826 const struct sctp_chunk *chunk)
827 {
828 struct sctp_chunk *retval;
829 __u8 flags = 0;
830
831 /* Set the T-bit if we have no association (vtag will be
832 * reflected)
833 */
834 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T;
835
836 retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 0);
837
838 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
839 *
840 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
841 * HEARTBEAT ACK, * etc.) to the same destination transport
842 * address from which it * received the DATA or control chunk
843 * to which it is replying.
844 *
845 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK
846 * came from.]
847 */
848 if (retval && chunk)
849 retval->transport = chunk->transport;
850
851 return retval;
852 }
853
854 /* Create an ABORT. Note that we set the T bit if we have no
855 * association, except when responding to an INIT (sctpimpguide 2.41).
856 */
857 struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc,
858 const struct sctp_chunk *chunk,
859 const size_t hint)
860 {
861 struct sctp_chunk *retval;
862 __u8 flags = 0;
863
864 /* Set the T-bit if we have no association and 'chunk' is not
865 * an INIT (vtag will be reflected).
866 */
867 if (!asoc) {
868 if (chunk && chunk->chunk_hdr &&
869 chunk->chunk_hdr->type == SCTP_CID_INIT)
870 flags = 0;
871 else
872 flags = SCTP_CHUNK_FLAG_T;
873 }
874
875 retval = sctp_make_chunk(asoc, SCTP_CID_ABORT, flags, hint);
876
877 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
878 *
879 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
880 * HEARTBEAT ACK, * etc.) to the same destination transport
881 * address from which it * received the DATA or control chunk
882 * to which it is replying.
883 *
884 * [ABORT back to where the offender came from.]
885 */
886 if (retval && chunk)
887 retval->transport = chunk->transport;
888
889 return retval;
890 }
891
892 /* Helper to create ABORT with a NO_USER_DATA error. */
893 struct sctp_chunk *sctp_make_abort_no_data(
894 const struct sctp_association *asoc,
895 const struct sctp_chunk *chunk, __u32 tsn)
896 {
897 struct sctp_chunk *retval;
898 __be32 payload;
899
900 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t)
901 + sizeof(tsn));
902
903 if (!retval)
904 goto no_mem;
905
906 /* Put the tsn back into network byte order. */
907 payload = htonl(tsn);
908 sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload));
909 sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload);
910
911 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
912 *
913 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
914 * HEARTBEAT ACK, * etc.) to the same destination transport
915 * address from which it * received the DATA or control chunk
916 * to which it is replying.
917 *
918 * [ABORT back to where the offender came from.]
919 */
920 if (chunk)
921 retval->transport = chunk->transport;
922
923 no_mem:
924 return retval;
925 }
926
927 /* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */
928 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc,
929 const struct msghdr *msg,
930 size_t paylen)
931 {
932 struct sctp_chunk *retval;
933 void *payload = NULL;
934 int err;
935
936 retval = sctp_make_abort(asoc, NULL, sizeof(sctp_errhdr_t) + paylen);
937 if (!retval)
938 goto err_chunk;
939
940 if (paylen) {
941 /* Put the msg_iov together into payload. */
942 payload = kmalloc(paylen, GFP_KERNEL);
943 if (!payload)
944 goto err_payload;
945
946 err = memcpy_fromiovec(payload, msg->msg_iov, paylen);
947 if (err < 0)
948 goto err_copy;
949 }
950
951 sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen);
952 sctp_addto_chunk(retval, paylen, payload);
953
954 if (paylen)
955 kfree(payload);
956
957 return retval;
958
959 err_copy:
960 kfree(payload);
961 err_payload:
962 sctp_chunk_free(retval);
963 retval = NULL;
964 err_chunk:
965 return retval;
966 }
967
968 /* Append bytes to the end of a parameter. Will panic if chunk is not big
969 * enough.
970 */
971 static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
972 const void *data)
973 {
974 void *target;
975 int chunklen = ntohs(chunk->chunk_hdr->length);
976
977 target = skb_put(chunk->skb, len);
978
979 memcpy(target, data, len);
980
981 /* Adjust the chunk length field. */
982 chunk->chunk_hdr->length = htons(chunklen + len);
983 chunk->chunk_end = skb_tail_pointer(chunk->skb);
984
985 return target;
986 }
987
988 /* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */
989 struct sctp_chunk *sctp_make_abort_violation(
990 const struct sctp_association *asoc,
991 const struct sctp_chunk *chunk,
992 const __u8 *payload,
993 const size_t paylen)
994 {
995 struct sctp_chunk *retval;
996 struct sctp_paramhdr phdr;
997
998 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) + paylen
999 + sizeof(sctp_paramhdr_t));
1000 if (!retval)
1001 goto end;
1002
1003 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen
1004 + sizeof(sctp_paramhdr_t));
1005
1006 phdr.type = htons(chunk->chunk_hdr->type);
1007 phdr.length = chunk->chunk_hdr->length;
1008 sctp_addto_chunk(retval, paylen, payload);
1009 sctp_addto_param(retval, sizeof(sctp_paramhdr_t), &phdr);
1010
1011 end:
1012 return retval;
1013 }
1014
1015 /* Make a HEARTBEAT chunk. */
1016 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc,
1017 const struct sctp_transport *transport,
1018 const void *payload, const size_t paylen)
1019 {
1020 struct sctp_chunk *retval = sctp_make_chunk(asoc, SCTP_CID_HEARTBEAT,
1021 0, paylen);
1022
1023 if (!retval)
1024 goto nodata;
1025
1026 /* Cast away the 'const', as this is just telling the chunk
1027 * what transport it belongs to.
1028 */
1029 retval->transport = (struct sctp_transport *) transport;
1030 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload);
1031
1032 nodata:
1033 return retval;
1034 }
1035
1036 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc,
1037 const struct sctp_chunk *chunk,
1038 const void *payload, const size_t paylen)
1039 {
1040 struct sctp_chunk *retval;
1041
1042 retval = sctp_make_chunk(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen);
1043 if (!retval)
1044 goto nodata;
1045
1046 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload);
1047
1048 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
1049 *
1050 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1051 * HEARTBEAT ACK, * etc.) to the same destination transport
1052 * address from which it * received the DATA or control chunk
1053 * to which it is replying.
1054 *
1055 * [HBACK back to where the HEARTBEAT came from.]
1056 */
1057 if (chunk)
1058 retval->transport = chunk->transport;
1059
1060 nodata:
1061 return retval;
1062 }
1063
1064 /* Create an Operation Error chunk with the specified space reserved.
1065 * This routine can be used for containing multiple causes in the chunk.
1066 */
1067 static struct sctp_chunk *sctp_make_op_error_space(
1068 const struct sctp_association *asoc,
1069 const struct sctp_chunk *chunk,
1070 size_t size)
1071 {
1072 struct sctp_chunk *retval;
1073
1074 retval = sctp_make_chunk(asoc, SCTP_CID_ERROR, 0,
1075 sizeof(sctp_errhdr_t) + size);
1076 if (!retval)
1077 goto nodata;
1078
1079 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
1080 *
1081 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1082 * HEARTBEAT ACK, etc.) to the same destination transport
1083 * address from which it received the DATA or control chunk
1084 * to which it is replying.
1085 *
1086 */
1087 if (chunk)
1088 retval->transport = chunk->transport;
1089
1090 nodata:
1091 return retval;
1092 }
1093
1094 /* Create an Operation Error chunk. */
1095 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc,
1096 const struct sctp_chunk *chunk,
1097 __be16 cause_code, const void *payload,
1098 size_t paylen)
1099 {
1100 struct sctp_chunk *retval;
1101
1102 retval = sctp_make_op_error_space(asoc, chunk, paylen);
1103 if (!retval)
1104 goto nodata;
1105
1106 sctp_init_cause(retval, cause_code, paylen);
1107 sctp_addto_chunk(retval, paylen, payload);
1108
1109 nodata:
1110 return retval;
1111 }
1112
1113 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc)
1114 {
1115 struct sctp_chunk *retval;
1116 struct sctp_hmac *hmac_desc;
1117 struct sctp_authhdr auth_hdr;
1118 __u8 *hmac;
1119
1120 /* Get the first hmac that the peer told us to use */
1121 hmac_desc = sctp_auth_asoc_get_hmac(asoc);
1122 if (unlikely(!hmac_desc))
1123 return NULL;
1124
1125 retval = sctp_make_chunk(asoc, SCTP_CID_AUTH, 0,
1126 hmac_desc->hmac_len + sizeof(sctp_authhdr_t));
1127 if (!retval)
1128 return NULL;
1129
1130 auth_hdr.hmac_id = htons(hmac_desc->hmac_id);
1131 auth_hdr.shkey_id = htons(asoc->active_key_id);
1132
1133 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(sctp_authhdr_t),
1134 &auth_hdr);
1135
1136 hmac = skb_put(retval->skb, hmac_desc->hmac_len);
1137 memset(hmac, 0, hmac_desc->hmac_len);
1138
1139 /* Adjust the chunk header to include the empty MAC */
1140 retval->chunk_hdr->length =
1141 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len);
1142 retval->chunk_end = skb_tail_pointer(retval->skb);
1143
1144 return retval;
1145 }
1146
1147
1148 /********************************************************************
1149 * 2nd Level Abstractions
1150 ********************************************************************/
1151
1152 /* Turn an skb into a chunk.
1153 * FIXME: Eventually move the structure directly inside the skb->cb[].
1154 */
1155 struct sctp_chunk *sctp_chunkify(struct sk_buff *skb,
1156 const struct sctp_association *asoc,
1157 struct sock *sk)
1158 {
1159 struct sctp_chunk *retval;
1160
1161 retval = kmem_cache_zalloc(sctp_chunk_cachep, GFP_ATOMIC);
1162
1163 if (!retval)
1164 goto nodata;
1165
1166 if (!sk) {
1167 SCTP_DEBUG_PRINTK("chunkifying skb %p w/o an sk\n", skb);
1168 }
1169
1170 INIT_LIST_HEAD(&retval->list);
1171 retval->skb = skb;
1172 retval->asoc = (struct sctp_association *)asoc;
1173 retval->resent = 0;
1174 retval->has_tsn = 0;
1175 retval->has_ssn = 0;
1176 retval->rtt_in_progress = 0;
1177 retval->sent_at = 0;
1178 retval->singleton = 1;
1179 retval->end_of_packet = 0;
1180 retval->ecn_ce_done = 0;
1181 retval->pdiscard = 0;
1182
1183 /* sctpimpguide-05.txt Section 2.8.2
1184 * M1) Each time a new DATA chunk is transmitted
1185 * set the 'TSN.Missing.Report' count for that TSN to 0. The
1186 * 'TSN.Missing.Report' count will be used to determine missing chunks
1187 * and when to fast retransmit.
1188 */
1189 retval->tsn_missing_report = 0;
1190 retval->tsn_gap_acked = 0;
1191 retval->fast_retransmit = 0;
1192
1193 /* If this is a fragmented message, track all fragments
1194 * of the message (for SEND_FAILED).
1195 */
1196 retval->msg = NULL;
1197
1198 /* Polish the bead hole. */
1199 INIT_LIST_HEAD(&retval->transmitted_list);
1200 INIT_LIST_HEAD(&retval->frag_list);
1201 SCTP_DBG_OBJCNT_INC(chunk);
1202 atomic_set(&retval->refcnt, 1);
1203
1204 nodata:
1205 return retval;
1206 }
1207
1208 /* Set chunk->source and dest based on the IP header in chunk->skb. */
1209 void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src,
1210 union sctp_addr *dest)
1211 {
1212 memcpy(&chunk->source, src, sizeof(union sctp_addr));
1213 memcpy(&chunk->dest, dest, sizeof(union sctp_addr));
1214 }
1215
1216 /* Extract the source address from a chunk. */
1217 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk)
1218 {
1219 /* If we have a known transport, use that. */
1220 if (chunk->transport) {
1221 return &chunk->transport->ipaddr;
1222 } else {
1223 /* Otherwise, extract it from the IP header. */
1224 return &chunk->source;
1225 }
1226 }
1227
1228 /* Create a new chunk, setting the type and flags headers from the
1229 * arguments, reserving enough space for a 'paylen' byte payload.
1230 */
1231 SCTP_STATIC
1232 struct sctp_chunk *sctp_make_chunk(const struct sctp_association *asoc,
1233 __u8 type, __u8 flags, int paylen)
1234 {
1235 struct sctp_chunk *retval;
1236 sctp_chunkhdr_t *chunk_hdr;
1237 struct sk_buff *skb;
1238 struct sock *sk;
1239
1240 /* No need to allocate LL here, as this is only a chunk. */
1241 skb = alloc_skb(WORD_ROUND(sizeof(sctp_chunkhdr_t) + paylen),
1242 GFP_ATOMIC);
1243 if (!skb)
1244 goto nodata;
1245
1246 /* Make room for the chunk header. */
1247 chunk_hdr = (sctp_chunkhdr_t *)skb_put(skb, sizeof(sctp_chunkhdr_t));
1248 chunk_hdr->type = type;
1249 chunk_hdr->flags = flags;
1250 chunk_hdr->length = htons(sizeof(sctp_chunkhdr_t));
1251
1252 sk = asoc ? asoc->base.sk : NULL;
1253 retval = sctp_chunkify(skb, asoc, sk);
1254 if (!retval) {
1255 kfree_skb(skb);
1256 goto nodata;
1257 }
1258
1259 retval->chunk_hdr = chunk_hdr;
1260 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(struct sctp_chunkhdr);
1261
1262 /* Determine if the chunk needs to be authenticated */
1263 if (sctp_auth_send_cid(type, asoc))
1264 retval->auth = 1;
1265
1266 /* Set the skb to the belonging sock for accounting. */
1267 skb->sk = sk;
1268
1269 return retval;
1270 nodata:
1271 return NULL;
1272 }
1273
1274
1275 /* Release the memory occupied by a chunk. */
1276 static void sctp_chunk_destroy(struct sctp_chunk *chunk)
1277 {
1278 BUG_ON(!list_empty(&chunk->list));
1279 list_del_init(&chunk->transmitted_list);
1280
1281 /* Free the chunk skb data and the SCTP_chunk stub itself. */
1282 dev_kfree_skb(chunk->skb);
1283
1284 SCTP_DBG_OBJCNT_DEC(chunk);
1285 kmem_cache_free(sctp_chunk_cachep, chunk);
1286 }
1287
1288 /* Possibly, free the chunk. */
1289 void sctp_chunk_free(struct sctp_chunk *chunk)
1290 {
1291 /* Release our reference on the message tracker. */
1292 if (chunk->msg)
1293 sctp_datamsg_put(chunk->msg);
1294
1295 sctp_chunk_put(chunk);
1296 }
1297
1298 /* Grab a reference to the chunk. */
1299 void sctp_chunk_hold(struct sctp_chunk *ch)
1300 {
1301 atomic_inc(&ch->refcnt);
1302 }
1303
1304 /* Release a reference to the chunk. */
1305 void sctp_chunk_put(struct sctp_chunk *ch)
1306 {
1307 if (atomic_dec_and_test(&ch->refcnt))
1308 sctp_chunk_destroy(ch);
1309 }
1310
1311 /* Append bytes to the end of a chunk. Will panic if chunk is not big
1312 * enough.
1313 */
1314 void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data)
1315 {
1316 void *target;
1317 void *padding;
1318 int chunklen = ntohs(chunk->chunk_hdr->length);
1319 int padlen = WORD_ROUND(chunklen) - chunklen;
1320
1321 padding = skb_put(chunk->skb, padlen);
1322 target = skb_put(chunk->skb, len);
1323
1324 memset(padding, 0, padlen);
1325 memcpy(target, data, len);
1326
1327 /* Adjust the chunk length field. */
1328 chunk->chunk_hdr->length = htons(chunklen + padlen + len);
1329 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1330
1331 return target;
1332 }
1333
1334 /* Append bytes from user space to the end of a chunk. Will panic if
1335 * chunk is not big enough.
1336 * Returns a kernel err value.
1337 */
1338 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len,
1339 struct iovec *data)
1340 {
1341 __u8 *target;
1342 int err = 0;
1343
1344 /* Make room in chunk for data. */
1345 target = skb_put(chunk->skb, len);
1346
1347 /* Copy data (whole iovec) into chunk */
1348 if ((err = memcpy_fromiovecend(target, data, off, len)))
1349 goto out;
1350
1351 /* Adjust the chunk length field. */
1352 chunk->chunk_hdr->length =
1353 htons(ntohs(chunk->chunk_hdr->length) + len);
1354 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1355
1356 out:
1357 return err;
1358 }
1359
1360 /* Helper function to assign a TSN if needed. This assumes that both
1361 * the data_hdr and association have already been assigned.
1362 */
1363 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk)
1364 {
1365 struct sctp_datamsg *msg;
1366 struct sctp_chunk *lchunk;
1367 struct sctp_stream *stream;
1368 __u16 ssn;
1369 __u16 sid;
1370
1371 if (chunk->has_ssn)
1372 return;
1373
1374 /* All fragments will be on the same stream */
1375 sid = ntohs(chunk->subh.data_hdr->stream);
1376 stream = &chunk->asoc->ssnmap->out;
1377
1378 /* Now assign the sequence number to the entire message.
1379 * All fragments must have the same stream sequence number.
1380 */
1381 msg = chunk->msg;
1382 list_for_each_entry(lchunk, &msg->chunks, frag_list) {
1383 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
1384 ssn = 0;
1385 } else {
1386 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG)
1387 ssn = sctp_ssn_next(stream, sid);
1388 else
1389 ssn = sctp_ssn_peek(stream, sid);
1390 }
1391
1392 lchunk->subh.data_hdr->ssn = htons(ssn);
1393 lchunk->has_ssn = 1;
1394 }
1395 }
1396
1397 /* Helper function to assign a TSN if needed. This assumes that both
1398 * the data_hdr and association have already been assigned.
1399 */
1400 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk)
1401 {
1402 if (!chunk->has_tsn) {
1403 /* This is the last possible instant to
1404 * assign a TSN.
1405 */
1406 chunk->subh.data_hdr->tsn =
1407 htonl(sctp_association_get_next_tsn(chunk->asoc));
1408 chunk->has_tsn = 1;
1409 }
1410 }
1411
1412 /* Create a CLOSED association to use with an incoming packet. */
1413 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep,
1414 struct sctp_chunk *chunk,
1415 gfp_t gfp)
1416 {
1417 struct sctp_association *asoc;
1418 struct sk_buff *skb;
1419 sctp_scope_t scope;
1420 struct sctp_af *af;
1421
1422 /* Create the bare association. */
1423 scope = sctp_scope(sctp_source(chunk));
1424 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp);
1425 if (!asoc)
1426 goto nodata;
1427 asoc->temp = 1;
1428 skb = chunk->skb;
1429 /* Create an entry for the source address of the packet. */
1430 af = sctp_get_af_specific(ipver2af(ip_hdr(skb)->version));
1431 if (unlikely(!af))
1432 goto fail;
1433 af->from_skb(&asoc->c.peer_addr, skb, 1);
1434 nodata:
1435 return asoc;
1436
1437 fail:
1438 sctp_association_free(asoc);
1439 return NULL;
1440 }
1441
1442 /* Build a cookie representing asoc.
1443 * This INCLUDES the param header needed to put the cookie in the INIT ACK.
1444 */
1445 static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep,
1446 const struct sctp_association *asoc,
1447 const struct sctp_chunk *init_chunk,
1448 int *cookie_len,
1449 const __u8 *raw_addrs, int addrs_len)
1450 {
1451 sctp_cookie_param_t *retval;
1452 struct sctp_signed_cookie *cookie;
1453 struct scatterlist sg;
1454 int headersize, bodysize;
1455 unsigned int keylen;
1456 char *key;
1457
1458 /* Header size is static data prior to the actual cookie, including
1459 * any padding.
1460 */
1461 headersize = sizeof(sctp_paramhdr_t) +
1462 (sizeof(struct sctp_signed_cookie) -
1463 sizeof(struct sctp_cookie));
1464 bodysize = sizeof(struct sctp_cookie)
1465 + ntohs(init_chunk->chunk_hdr->length) + addrs_len;
1466
1467 /* Pad out the cookie to a multiple to make the signature
1468 * functions simpler to write.
1469 */
1470 if (bodysize % SCTP_COOKIE_MULTIPLE)
1471 bodysize += SCTP_COOKIE_MULTIPLE
1472 - (bodysize % SCTP_COOKIE_MULTIPLE);
1473 *cookie_len = headersize + bodysize;
1474
1475 /* Clear this memory since we are sending this data structure
1476 * out on the network.
1477 */
1478 retval = kzalloc(*cookie_len, GFP_ATOMIC);
1479 if (!retval)
1480 goto nodata;
1481
1482 cookie = (struct sctp_signed_cookie *) retval->body;
1483
1484 /* Set up the parameter header. */
1485 retval->p.type = SCTP_PARAM_STATE_COOKIE;
1486 retval->p.length = htons(*cookie_len);
1487
1488 /* Copy the cookie part of the association itself. */
1489 cookie->c = asoc->c;
1490 /* Save the raw address list length in the cookie. */
1491 cookie->c.raw_addr_list_len = addrs_len;
1492
1493 /* Remember PR-SCTP capability. */
1494 cookie->c.prsctp_capable = asoc->peer.prsctp_capable;
1495
1496 /* Save adaptation indication in the cookie. */
1497 cookie->c.adaptation_ind = asoc->peer.adaptation_ind;
1498
1499 /* Set an expiration time for the cookie. */
1500 do_gettimeofday(&cookie->c.expiration);
1501 TIMEVAL_ADD(asoc->cookie_life, cookie->c.expiration);
1502
1503 /* Copy the peer's init packet. */
1504 memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr,
1505 ntohs(init_chunk->chunk_hdr->length));
1506
1507 /* Copy the raw local address list of the association. */
1508 memcpy((__u8 *)&cookie->c.peer_init[0] +
1509 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len);
1510
1511 if (sctp_sk(ep->base.sk)->hmac) {
1512 struct hash_desc desc;
1513
1514 /* Sign the message. */
1515 sg_init_one(&sg, &cookie->c, bodysize);
1516 keylen = SCTP_SECRET_SIZE;
1517 key = (char *)ep->secret_key[ep->current_key];
1518 desc.tfm = sctp_sk(ep->base.sk)->hmac;
1519 desc.flags = 0;
1520
1521 if (crypto_hash_setkey(desc.tfm, key, keylen) ||
1522 crypto_hash_digest(&desc, &sg, bodysize, cookie->signature))
1523 goto free_cookie;
1524 }
1525
1526 return retval;
1527
1528 free_cookie:
1529 kfree(retval);
1530 nodata:
1531 *cookie_len = 0;
1532 return NULL;
1533 }
1534
1535 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */
1536 struct sctp_association *sctp_unpack_cookie(
1537 const struct sctp_endpoint *ep,
1538 const struct sctp_association *asoc,
1539 struct sctp_chunk *chunk, gfp_t gfp,
1540 int *error, struct sctp_chunk **errp)
1541 {
1542 struct sctp_association *retval = NULL;
1543 struct sctp_signed_cookie *cookie;
1544 struct sctp_cookie *bear_cookie;
1545 int headersize, bodysize, fixed_size;
1546 __u8 *digest = ep->digest;
1547 struct scatterlist sg;
1548 unsigned int keylen, len;
1549 char *key;
1550 sctp_scope_t scope;
1551 struct sk_buff *skb = chunk->skb;
1552 struct timeval tv;
1553 struct hash_desc desc;
1554
1555 /* Header size is static data prior to the actual cookie, including
1556 * any padding.
1557 */
1558 headersize = sizeof(sctp_chunkhdr_t) +
1559 (sizeof(struct sctp_signed_cookie) -
1560 sizeof(struct sctp_cookie));
1561 bodysize = ntohs(chunk->chunk_hdr->length) - headersize;
1562 fixed_size = headersize + sizeof(struct sctp_cookie);
1563
1564 /* Verify that the chunk looks like it even has a cookie.
1565 * There must be enough room for our cookie and our peer's
1566 * INIT chunk.
1567 */
1568 len = ntohs(chunk->chunk_hdr->length);
1569 if (len < fixed_size + sizeof(struct sctp_chunkhdr))
1570 goto malformed;
1571
1572 /* Verify that the cookie has been padded out. */
1573 if (bodysize % SCTP_COOKIE_MULTIPLE)
1574 goto malformed;
1575
1576 /* Process the cookie. */
1577 cookie = chunk->subh.cookie_hdr;
1578 bear_cookie = &cookie->c;
1579
1580 if (!sctp_sk(ep->base.sk)->hmac)
1581 goto no_hmac;
1582
1583 /* Check the signature. */
1584 keylen = SCTP_SECRET_SIZE;
1585 sg_init_one(&sg, bear_cookie, bodysize);
1586 key = (char *)ep->secret_key[ep->current_key];
1587 desc.tfm = sctp_sk(ep->base.sk)->hmac;
1588 desc.flags = 0;
1589
1590 memset(digest, 0x00, SCTP_SIGNATURE_SIZE);
1591 if (crypto_hash_setkey(desc.tfm, key, keylen) ||
1592 crypto_hash_digest(&desc, &sg, bodysize, digest)) {
1593 *error = -SCTP_IERROR_NOMEM;
1594 goto fail;
1595 }
1596
1597 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
1598 /* Try the previous key. */
1599 key = (char *)ep->secret_key[ep->last_key];
1600 memset(digest, 0x00, SCTP_SIGNATURE_SIZE);
1601 if (crypto_hash_setkey(desc.tfm, key, keylen) ||
1602 crypto_hash_digest(&desc, &sg, bodysize, digest)) {
1603 *error = -SCTP_IERROR_NOMEM;
1604 goto fail;
1605 }
1606
1607 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
1608 /* Yikes! Still bad signature! */
1609 *error = -SCTP_IERROR_BAD_SIG;
1610 goto fail;
1611 }
1612 }
1613
1614 no_hmac:
1615 /* IG Section 2.35.2:
1616 * 3) Compare the port numbers and the verification tag contained
1617 * within the COOKIE ECHO chunk to the actual port numbers and the
1618 * verification tag within the SCTP common header of the received
1619 * packet. If these values do not match the packet MUST be silently
1620 * discarded,
1621 */
1622 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) {
1623 *error = -SCTP_IERROR_BAD_TAG;
1624 goto fail;
1625 }
1626
1627 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port ||
1628 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) {
1629 *error = -SCTP_IERROR_BAD_PORTS;
1630 goto fail;
1631 }
1632
1633 /* Check to see if the cookie is stale. If there is already
1634 * an association, there is no need to check cookie's expiration
1635 * for init collision case of lost COOKIE ACK.
1636 * If skb has been timestamped, then use the stamp, otherwise
1637 * use current time. This introduces a small possibility that
1638 * that a cookie may be considered expired, but his would only slow
1639 * down the new association establishment instead of every packet.
1640 */
1641 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP))
1642 skb_get_timestamp(skb, &tv);
1643 else
1644 do_gettimeofday(&tv);
1645
1646 if (!asoc && tv_lt(bear_cookie->expiration, tv)) {
1647 /*
1648 * Section 3.3.10.3 Stale Cookie Error (3)
1649 *
1650 * Cause of error
1651 * ---------------
1652 * Stale Cookie Error: Indicates the receipt of a valid State
1653 * Cookie that has expired.
1654 */
1655 len = ntohs(chunk->chunk_hdr->length);
1656 *errp = sctp_make_op_error_space(asoc, chunk, len);
1657 if (*errp) {
1658 suseconds_t usecs = (tv.tv_sec -
1659 bear_cookie->expiration.tv_sec) * 1000000L +
1660 tv.tv_usec - bear_cookie->expiration.tv_usec;
1661 __be32 n = htonl(usecs);
1662
1663 sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE,
1664 sizeof(n));
1665 sctp_addto_chunk(*errp, sizeof(n), &n);
1666 *error = -SCTP_IERROR_STALE_COOKIE;
1667 } else
1668 *error = -SCTP_IERROR_NOMEM;
1669
1670 goto fail;
1671 }
1672
1673 /* Make a new base association. */
1674 scope = sctp_scope(sctp_source(chunk));
1675 retval = sctp_association_new(ep, ep->base.sk, scope, gfp);
1676 if (!retval) {
1677 *error = -SCTP_IERROR_NOMEM;
1678 goto fail;
1679 }
1680
1681 /* Set up our peer's port number. */
1682 retval->peer.port = ntohs(chunk->sctp_hdr->source);
1683
1684 /* Populate the association from the cookie. */
1685 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie));
1686
1687 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie,
1688 GFP_ATOMIC) < 0) {
1689 *error = -SCTP_IERROR_NOMEM;
1690 goto fail;
1691 }
1692
1693 /* Also, add the destination address. */
1694 if (list_empty(&retval->base.bind_addr.address_list)) {
1695 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest,
1696 SCTP_ADDR_SRC, GFP_ATOMIC);
1697 }
1698
1699 retval->next_tsn = retval->c.initial_tsn;
1700 retval->ctsn_ack_point = retval->next_tsn - 1;
1701 retval->addip_serial = retval->c.initial_tsn;
1702 retval->adv_peer_ack_point = retval->ctsn_ack_point;
1703 retval->peer.prsctp_capable = retval->c.prsctp_capable;
1704 retval->peer.adaptation_ind = retval->c.adaptation_ind;
1705
1706 /* The INIT stuff will be done by the side effects. */
1707 return retval;
1708
1709 fail:
1710 if (retval)
1711 sctp_association_free(retval);
1712
1713 return NULL;
1714
1715 malformed:
1716 /* Yikes! The packet is either corrupt or deliberately
1717 * malformed.
1718 */
1719 *error = -SCTP_IERROR_MALFORMED;
1720 goto fail;
1721 }
1722
1723 /********************************************************************
1724 * 3rd Level Abstractions
1725 ********************************************************************/
1726
1727 struct __sctp_missing {
1728 __be32 num_missing;
1729 __be16 type;
1730 } __attribute__((packed));
1731
1732 /*
1733 * Report a missing mandatory parameter.
1734 */
1735 static int sctp_process_missing_param(const struct sctp_association *asoc,
1736 sctp_param_t paramtype,
1737 struct sctp_chunk *chunk,
1738 struct sctp_chunk **errp)
1739 {
1740 struct __sctp_missing report;
1741 __u16 len;
1742
1743 len = WORD_ROUND(sizeof(report));
1744
1745 /* Make an ERROR chunk, preparing enough room for
1746 * returning multiple unknown parameters.
1747 */
1748 if (!*errp)
1749 *errp = sctp_make_op_error_space(asoc, chunk, len);
1750
1751 if (*errp) {
1752 report.num_missing = htonl(1);
1753 report.type = paramtype;
1754 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM,
1755 sizeof(report));
1756 sctp_addto_chunk(*errp, sizeof(report), &report);
1757 }
1758
1759 /* Stop processing this chunk. */
1760 return 0;
1761 }
1762
1763 /* Report an Invalid Mandatory Parameter. */
1764 static int sctp_process_inv_mandatory(const struct sctp_association *asoc,
1765 struct sctp_chunk *chunk,
1766 struct sctp_chunk **errp)
1767 {
1768 /* Invalid Mandatory Parameter Error has no payload. */
1769
1770 if (!*errp)
1771 *errp = sctp_make_op_error_space(asoc, chunk, 0);
1772
1773 if (*errp)
1774 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0);
1775
1776 /* Stop processing this chunk. */
1777 return 0;
1778 }
1779
1780 static int sctp_process_inv_paramlength(const struct sctp_association *asoc,
1781 struct sctp_paramhdr *param,
1782 const struct sctp_chunk *chunk,
1783 struct sctp_chunk **errp)
1784 {
1785 char error[] = "The following parameter had invalid length:";
1786 size_t payload_len = WORD_ROUND(sizeof(error)) +
1787 sizeof(sctp_paramhdr_t);
1788
1789
1790 /* This is a fatal error. Any accumulated non-fatal errors are
1791 * not reported.
1792 */
1793 if (*errp)
1794 sctp_chunk_free(*errp);
1795
1796 /* Create an error chunk and fill it in with our payload. */
1797 *errp = sctp_make_op_error_space(asoc, chunk, payload_len);
1798
1799 if (*errp) {
1800 sctp_init_cause(*errp, SCTP_ERROR_PROTO_VIOLATION,
1801 sizeof(error) + sizeof(sctp_paramhdr_t));
1802 sctp_addto_chunk(*errp, sizeof(error), error);
1803 sctp_addto_param(*errp, sizeof(sctp_paramhdr_t), param);
1804 }
1805
1806 return 0;
1807 }
1808
1809
1810 /* Do not attempt to handle the HOST_NAME parm. However, do
1811 * send back an indicator to the peer.
1812 */
1813 static int sctp_process_hn_param(const struct sctp_association *asoc,
1814 union sctp_params param,
1815 struct sctp_chunk *chunk,
1816 struct sctp_chunk **errp)
1817 {
1818 __u16 len = ntohs(param.p->length);
1819
1820 /* Processing of the HOST_NAME parameter will generate an
1821 * ABORT. If we've accumulated any non-fatal errors, they
1822 * would be unrecognized parameters and we should not include
1823 * them in the ABORT.
1824 */
1825 if (*errp)
1826 sctp_chunk_free(*errp);
1827
1828 *errp = sctp_make_op_error_space(asoc, chunk, len);
1829
1830 if (*errp) {
1831 sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, len);
1832 sctp_addto_chunk(*errp, len, param.v);
1833 }
1834
1835 /* Stop processing this chunk. */
1836 return 0;
1837 }
1838
1839 static int sctp_verify_ext_param(union sctp_params param)
1840 {
1841 __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
1842 int have_auth = 0;
1843 int have_asconf = 0;
1844 int i;
1845
1846 for (i = 0; i < num_ext; i++) {
1847 switch (param.ext->chunks[i]) {
1848 case SCTP_CID_AUTH:
1849 have_auth = 1;
1850 break;
1851 case SCTP_CID_ASCONF:
1852 case SCTP_CID_ASCONF_ACK:
1853 have_asconf = 1;
1854 break;
1855 }
1856 }
1857
1858 /* ADD-IP Security: The draft requires us to ABORT or ignore the
1859 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this
1860 * only if ADD-IP is turned on and we are not backward-compatible
1861 * mode.
1862 */
1863 if (sctp_addip_noauth)
1864 return 1;
1865
1866 if (sctp_addip_enable && !have_auth && have_asconf)
1867 return 0;
1868
1869 return 1;
1870 }
1871
1872 static void sctp_process_ext_param(struct sctp_association *asoc,
1873 union sctp_params param)
1874 {
1875 __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
1876 int i;
1877
1878 for (i = 0; i < num_ext; i++) {
1879 switch (param.ext->chunks[i]) {
1880 case SCTP_CID_FWD_TSN:
1881 if (sctp_prsctp_enable &&
1882 !asoc->peer.prsctp_capable)
1883 asoc->peer.prsctp_capable = 1;
1884 break;
1885 case SCTP_CID_AUTH:
1886 /* if the peer reports AUTH, assume that he
1887 * supports AUTH.
1888 */
1889 asoc->peer.auth_capable = 1;
1890 break;
1891 case SCTP_CID_ASCONF:
1892 case SCTP_CID_ASCONF_ACK:
1893 asoc->peer.asconf_capable = 1;
1894 break;
1895 default:
1896 break;
1897 }
1898 }
1899 }
1900
1901 /* RFC 3.2.1 & the Implementers Guide 2.2.
1902 *
1903 * The Parameter Types are encoded such that the
1904 * highest-order two bits specify the action that must be
1905 * taken if the processing endpoint does not recognize the
1906 * Parameter Type.
1907 *
1908 * 00 - Stop processing this parameter; do not process any further
1909 * parameters within this chunk
1910 *
1911 * 01 - Stop processing this parameter, do not process any further
1912 * parameters within this chunk, and report the unrecognized
1913 * parameter in an 'Unrecognized Parameter' ERROR chunk.
1914 *
1915 * 10 - Skip this parameter and continue processing.
1916 *
1917 * 11 - Skip this parameter and continue processing but
1918 * report the unrecognized parameter in an
1919 * 'Unrecognized Parameter' ERROR chunk.
1920 *
1921 * Return value:
1922 * SCTP_IERROR_NO_ERROR - continue with the chunk
1923 * SCTP_IERROR_ERROR - stop and report an error.
1924 * SCTP_IERROR_NOMEME - out of memory.
1925 */
1926 static sctp_ierror_t sctp_process_unk_param(const struct sctp_association *asoc,
1927 union sctp_params param,
1928 struct sctp_chunk *chunk,
1929 struct sctp_chunk **errp)
1930 {
1931 int retval = SCTP_IERROR_NO_ERROR;
1932
1933 switch (param.p->type & SCTP_PARAM_ACTION_MASK) {
1934 case SCTP_PARAM_ACTION_DISCARD:
1935 retval = SCTP_IERROR_ERROR;
1936 break;
1937 case SCTP_PARAM_ACTION_SKIP:
1938 break;
1939 case SCTP_PARAM_ACTION_DISCARD_ERR:
1940 retval = SCTP_IERROR_ERROR;
1941 /* Fall through */
1942 case SCTP_PARAM_ACTION_SKIP_ERR:
1943 /* Make an ERROR chunk, preparing enough room for
1944 * returning multiple unknown parameters.
1945 */
1946 if (NULL == *errp)
1947 *errp = sctp_make_op_error_space(asoc, chunk,
1948 ntohs(chunk->chunk_hdr->length));
1949
1950 if (*errp) {
1951 sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM,
1952 WORD_ROUND(ntohs(param.p->length)));
1953 sctp_addto_chunk(*errp,
1954 WORD_ROUND(ntohs(param.p->length)),
1955 param.v);
1956 } else {
1957 /* If there is no memory for generating the ERROR
1958 * report as specified, an ABORT will be triggered
1959 * to the peer and the association won't be
1960 * established.
1961 */
1962 retval = SCTP_IERROR_NOMEM;
1963 }
1964 break;
1965 default:
1966 break;
1967 }
1968
1969 return retval;
1970 }
1971
1972 /* Verify variable length parameters
1973 * Return values:
1974 * SCTP_IERROR_ABORT - trigger an ABORT
1975 * SCTP_IERROR_NOMEM - out of memory (abort)
1976 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR
1977 * SCTP_IERROR_NO_ERROR - continue with the chunk
1978 */
1979 static sctp_ierror_t sctp_verify_param(const struct sctp_association *asoc,
1980 union sctp_params param,
1981 sctp_cid_t cid,
1982 struct sctp_chunk *chunk,
1983 struct sctp_chunk **err_chunk)
1984 {
1985 struct sctp_hmac_algo_param *hmacs;
1986 int retval = SCTP_IERROR_NO_ERROR;
1987 __u16 n_elt, id = 0;
1988 int i;
1989
1990 /* FIXME - This routine is not looking at each parameter per the
1991 * chunk type, i.e., unrecognized parameters should be further
1992 * identified based on the chunk id.
1993 */
1994
1995 switch (param.p->type) {
1996 case SCTP_PARAM_IPV4_ADDRESS:
1997 case SCTP_PARAM_IPV6_ADDRESS:
1998 case SCTP_PARAM_COOKIE_PRESERVATIVE:
1999 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
2000 case SCTP_PARAM_STATE_COOKIE:
2001 case SCTP_PARAM_HEARTBEAT_INFO:
2002 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
2003 case SCTP_PARAM_ECN_CAPABLE:
2004 case SCTP_PARAM_ADAPTATION_LAYER_IND:
2005 break;
2006
2007 case SCTP_PARAM_SUPPORTED_EXT:
2008 if (!sctp_verify_ext_param(param))
2009 return SCTP_IERROR_ABORT;
2010 break;
2011
2012 case SCTP_PARAM_SET_PRIMARY:
2013 if (sctp_addip_enable)
2014 break;
2015 goto fallthrough;
2016
2017 case SCTP_PARAM_HOST_NAME_ADDRESS:
2018 /* Tell the peer, we won't support this param. */
2019 sctp_process_hn_param(asoc, param, chunk, err_chunk);
2020 retval = SCTP_IERROR_ABORT;
2021 break;
2022
2023 case SCTP_PARAM_FWD_TSN_SUPPORT:
2024 if (sctp_prsctp_enable)
2025 break;
2026 goto fallthrough;
2027
2028 case SCTP_PARAM_RANDOM:
2029 if (!sctp_auth_enable)
2030 goto fallthrough;
2031
2032 /* SCTP-AUTH: Secion 6.1
2033 * If the random number is not 32 byte long the association
2034 * MUST be aborted. The ABORT chunk SHOULD contain the error
2035 * cause 'Protocol Violation'.
2036 */
2037 if (SCTP_AUTH_RANDOM_LENGTH !=
2038 ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) {
2039 sctp_process_inv_paramlength(asoc, param.p,
2040 chunk, err_chunk);
2041 retval = SCTP_IERROR_ABORT;
2042 }
2043 break;
2044
2045 case SCTP_PARAM_CHUNKS:
2046 if (!sctp_auth_enable)
2047 goto fallthrough;
2048
2049 /* SCTP-AUTH: Section 3.2
2050 * The CHUNKS parameter MUST be included once in the INIT or
2051 * INIT-ACK chunk if the sender wants to receive authenticated
2052 * chunks. Its maximum length is 260 bytes.
2053 */
2054 if (260 < ntohs(param.p->length)) {
2055 sctp_process_inv_paramlength(asoc, param.p,
2056 chunk, err_chunk);
2057 retval = SCTP_IERROR_ABORT;
2058 }
2059 break;
2060
2061 case SCTP_PARAM_HMAC_ALGO:
2062 if (!sctp_auth_enable)
2063 goto fallthrough;
2064
2065 hmacs = (struct sctp_hmac_algo_param *)param.p;
2066 n_elt = (ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) >> 1;
2067
2068 /* SCTP-AUTH: Section 6.1
2069 * The HMAC algorithm based on SHA-1 MUST be supported and
2070 * included in the HMAC-ALGO parameter.
2071 */
2072 for (i = 0; i < n_elt; i++) {
2073 id = ntohs(hmacs->hmac_ids[i]);
2074
2075 if (id == SCTP_AUTH_HMAC_ID_SHA1)
2076 break;
2077 }
2078
2079 if (id != SCTP_AUTH_HMAC_ID_SHA1) {
2080 sctp_process_inv_paramlength(asoc, param.p, chunk,
2081 err_chunk);
2082 retval = SCTP_IERROR_ABORT;
2083 }
2084 break;
2085 fallthrough:
2086 default:
2087 SCTP_DEBUG_PRINTK("Unrecognized param: %d for chunk %d.\n",
2088 ntohs(param.p->type), cid);
2089 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk);
2090 break;
2091 }
2092 return retval;
2093 }
2094
2095 /* Verify the INIT packet before we process it. */
2096 int sctp_verify_init(const struct sctp_association *asoc,
2097 sctp_cid_t cid,
2098 sctp_init_chunk_t *peer_init,
2099 struct sctp_chunk *chunk,
2100 struct sctp_chunk **errp)
2101 {
2102 union sctp_params param;
2103 int has_cookie = 0;
2104 int result;
2105
2106 /* Verify stream values are non-zero. */
2107 if ((0 == peer_init->init_hdr.num_outbound_streams) ||
2108 (0 == peer_init->init_hdr.num_inbound_streams) ||
2109 (0 == peer_init->init_hdr.init_tag) ||
2110 (SCTP_DEFAULT_MINWINDOW > ntohl(peer_init->init_hdr.a_rwnd))) {
2111
2112 return sctp_process_inv_mandatory(asoc, chunk, errp);
2113 }
2114
2115 /* Check for missing mandatory parameters. */
2116 sctp_walk_params(param, peer_init, init_hdr.params) {
2117
2118 if (SCTP_PARAM_STATE_COOKIE == param.p->type)
2119 has_cookie = 1;
2120
2121 } /* for (loop through all parameters) */
2122
2123 /* There is a possibility that a parameter length was bad and
2124 * in that case we would have stoped walking the parameters.
2125 * The current param.p would point at the bad one.
2126 * Current consensus on the mailing list is to generate a PROTOCOL
2127 * VIOLATION error. We build the ERROR chunk here and let the normal
2128 * error handling code build and send the packet.
2129 */
2130 if (param.v != (void*)chunk->chunk_end)
2131 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp);
2132
2133 /* The only missing mandatory param possible today is
2134 * the state cookie for an INIT-ACK chunk.
2135 */
2136 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie)
2137 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE,
2138 chunk, errp);
2139
2140 /* Verify all the variable length parameters */
2141 sctp_walk_params(param, peer_init, init_hdr.params) {
2142
2143 result = sctp_verify_param(asoc, param, cid, chunk, errp);
2144 switch (result) {
2145 case SCTP_IERROR_ABORT:
2146 case SCTP_IERROR_NOMEM:
2147 return 0;
2148 case SCTP_IERROR_ERROR:
2149 return 1;
2150 case SCTP_IERROR_NO_ERROR:
2151 default:
2152 break;
2153 }
2154
2155 } /* for (loop through all parameters) */
2156
2157 return 1;
2158 }
2159
2160 /* Unpack the parameters in an INIT packet into an association.
2161 * Returns 0 on failure, else success.
2162 * FIXME: This is an association method.
2163 */
2164 int sctp_process_init(struct sctp_association *asoc, sctp_cid_t cid,
2165 const union sctp_addr *peer_addr,
2166 sctp_init_chunk_t *peer_init, gfp_t gfp)
2167 {
2168 union sctp_params param;
2169 struct sctp_transport *transport;
2170 struct list_head *pos, *temp;
2171 char *cookie;
2172
2173 /* We must include the address that the INIT packet came from.
2174 * This is the only address that matters for an INIT packet.
2175 * When processing a COOKIE ECHO, we retrieve the from address
2176 * of the INIT from the cookie.
2177 */
2178
2179 /* This implementation defaults to making the first transport
2180 * added as the primary transport. The source address seems to
2181 * be a a better choice than any of the embedded addresses.
2182 */
2183 if (peer_addr) {
2184 if(!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE))
2185 goto nomem;
2186 }
2187
2188 /* Process the initialization parameters. */
2189 sctp_walk_params(param, peer_init, init_hdr.params) {
2190
2191 if (!sctp_process_param(asoc, param, peer_addr, gfp))
2192 goto clean_up;
2193 }
2194
2195 /* AUTH: After processing the parameters, make sure that we
2196 * have all the required info to potentially do authentications.
2197 */
2198 if (asoc->peer.auth_capable && (!asoc->peer.peer_random ||
2199 !asoc->peer.peer_hmacs))
2200 asoc->peer.auth_capable = 0;
2201
2202 /* In a non-backward compatible mode, if the peer claims
2203 * support for ADD-IP but not AUTH, the ADD-IP spec states
2204 * that we MUST ABORT the association. Section 6. The section
2205 * also give us an option to silently ignore the packet, which
2206 * is what we'll do here.
2207 */
2208 if (!sctp_addip_noauth &&
2209 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) {
2210 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP |
2211 SCTP_PARAM_DEL_IP |
2212 SCTP_PARAM_SET_PRIMARY);
2213 asoc->peer.asconf_capable = 0;
2214 goto clean_up;
2215 }
2216
2217 /* Walk list of transports, removing transports in the UNKNOWN state. */
2218 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
2219 transport = list_entry(pos, struct sctp_transport, transports);
2220 if (transport->state == SCTP_UNKNOWN) {
2221 sctp_assoc_rm_peer(asoc, transport);
2222 }
2223 }
2224
2225 /* The fixed INIT headers are always in network byte
2226 * order.
2227 */
2228 asoc->peer.i.init_tag =
2229 ntohl(peer_init->init_hdr.init_tag);
2230 asoc->peer.i.a_rwnd =
2231 ntohl(peer_init->init_hdr.a_rwnd);
2232 asoc->peer.i.num_outbound_streams =
2233 ntohs(peer_init->init_hdr.num_outbound_streams);
2234 asoc->peer.i.num_inbound_streams =
2235 ntohs(peer_init->init_hdr.num_inbound_streams);
2236 asoc->peer.i.initial_tsn =
2237 ntohl(peer_init->init_hdr.initial_tsn);
2238
2239 /* Apply the upper bounds for output streams based on peer's
2240 * number of inbound streams.
2241 */
2242 if (asoc->c.sinit_num_ostreams >
2243 ntohs(peer_init->init_hdr.num_inbound_streams)) {
2244 asoc->c.sinit_num_ostreams =
2245 ntohs(peer_init->init_hdr.num_inbound_streams);
2246 }
2247
2248 if (asoc->c.sinit_max_instreams >
2249 ntohs(peer_init->init_hdr.num_outbound_streams)) {
2250 asoc->c.sinit_max_instreams =
2251 ntohs(peer_init->init_hdr.num_outbound_streams);
2252 }
2253
2254 /* Copy Initiation tag from INIT to VT_peer in cookie. */
2255 asoc->c.peer_vtag = asoc->peer.i.init_tag;
2256
2257 /* Peer Rwnd : Current calculated value of the peer's rwnd. */
2258 asoc->peer.rwnd = asoc->peer.i.a_rwnd;
2259
2260 /* Copy cookie in case we need to resend COOKIE-ECHO. */
2261 cookie = asoc->peer.cookie;
2262 if (cookie) {
2263 asoc->peer.cookie = kmemdup(cookie, asoc->peer.cookie_len, gfp);
2264 if (!asoc->peer.cookie)
2265 goto clean_up;
2266 }
2267
2268 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily
2269 * high (for example, implementations MAY use the size of the receiver
2270 * advertised window).
2271 */
2272 list_for_each(pos, &asoc->peer.transport_addr_list) {
2273 transport = list_entry(pos, struct sctp_transport, transports);
2274 transport->ssthresh = asoc->peer.i.a_rwnd;
2275 }
2276
2277 /* Set up the TSN tracking pieces. */
2278 sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_SIZE,
2279 asoc->peer.i.initial_tsn);
2280
2281 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
2282 *
2283 * The stream sequence number in all the streams shall start
2284 * from 0 when the association is established. Also, when the
2285 * stream sequence number reaches the value 65535 the next
2286 * stream sequence number shall be set to 0.
2287 */
2288
2289 /* Allocate storage for the negotiated streams if it is not a temporary
2290 * association.
2291 */
2292 if (!asoc->temp) {
2293 int error;
2294
2295 asoc->ssnmap = sctp_ssnmap_new(asoc->c.sinit_max_instreams,
2296 asoc->c.sinit_num_ostreams, gfp);
2297 if (!asoc->ssnmap)
2298 goto clean_up;
2299
2300 error = sctp_assoc_set_id(asoc, gfp);
2301 if (error)
2302 goto clean_up;
2303 }
2304
2305 /* ADDIP Section 4.1 ASCONF Chunk Procedures
2306 *
2307 * When an endpoint has an ASCONF signaled change to be sent to the
2308 * remote endpoint it should do the following:
2309 * ...
2310 * A2) A serial number should be assigned to the Chunk. The serial
2311 * number should be a monotonically increasing number. All serial
2312 * numbers are defined to be initialized at the start of the
2313 * association to the same value as the Initial TSN.
2314 */
2315 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1;
2316 return 1;
2317
2318 clean_up:
2319 /* Release the transport structures. */
2320 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
2321 transport = list_entry(pos, struct sctp_transport, transports);
2322 list_del_init(pos);
2323 sctp_transport_free(transport);
2324 }
2325
2326 asoc->peer.transport_count = 0;
2327
2328 nomem:
2329 return 0;
2330 }
2331
2332
2333 /* Update asoc with the option described in param.
2334 *
2335 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT
2336 *
2337 * asoc is the association to update.
2338 * param is the variable length parameter to use for update.
2339 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO.
2340 * If the current packet is an INIT we want to minimize the amount of
2341 * work we do. In particular, we should not build transport
2342 * structures for the addresses.
2343 */
2344 static int sctp_process_param(struct sctp_association *asoc,
2345 union sctp_params param,
2346 const union sctp_addr *peer_addr,
2347 gfp_t gfp)
2348 {
2349 union sctp_addr addr;
2350 int i;
2351 __u16 sat;
2352 int retval = 1;
2353 sctp_scope_t scope;
2354 time_t stale;
2355 struct sctp_af *af;
2356 union sctp_addr_param *addr_param;
2357 struct sctp_transport *t;
2358
2359 /* We maintain all INIT parameters in network byte order all the
2360 * time. This allows us to not worry about whether the parameters
2361 * came from a fresh INIT, and INIT ACK, or were stored in a cookie.
2362 */
2363 switch (param.p->type) {
2364 case SCTP_PARAM_IPV6_ADDRESS:
2365 if (PF_INET6 != asoc->base.sk->sk_family)
2366 break;
2367 /* Fall through. */
2368 case SCTP_PARAM_IPV4_ADDRESS:
2369 af = sctp_get_af_specific(param_type2af(param.p->type));
2370 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0);
2371 scope = sctp_scope(peer_addr);
2372 if (sctp_in_scope(&addr, scope))
2373 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED))
2374 return 0;
2375 break;
2376
2377 case SCTP_PARAM_COOKIE_PRESERVATIVE:
2378 if (!sctp_cookie_preserve_enable)
2379 break;
2380
2381 stale = ntohl(param.life->lifespan_increment);
2382
2383 /* Suggested Cookie Life span increment's unit is msec,
2384 * (1/1000sec).
2385 */
2386 asoc->cookie_life.tv_sec += stale / 1000;
2387 asoc->cookie_life.tv_usec += (stale % 1000) * 1000;
2388 break;
2389
2390 case SCTP_PARAM_HOST_NAME_ADDRESS:
2391 SCTP_DEBUG_PRINTK("unimplemented SCTP_HOST_NAME_ADDRESS\n");
2392 break;
2393
2394 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
2395 /* Turn off the default values first so we'll know which
2396 * ones are really set by the peer.
2397 */
2398 asoc->peer.ipv4_address = 0;
2399 asoc->peer.ipv6_address = 0;
2400
2401 /* Assume that peer supports the address family
2402 * by which it sends a packet.
2403 */
2404 if (peer_addr->sa.sa_family == AF_INET6)
2405 asoc->peer.ipv6_address = 1;
2406 else if (peer_addr->sa.sa_family == AF_INET)
2407 asoc->peer.ipv4_address = 1;
2408
2409 /* Cycle through address types; avoid divide by 0. */
2410 sat = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
2411 if (sat)
2412 sat /= sizeof(__u16);
2413
2414 for (i = 0; i < sat; ++i) {
2415 switch (param.sat->types[i]) {
2416 case SCTP_PARAM_IPV4_ADDRESS:
2417 asoc->peer.ipv4_address = 1;
2418 break;
2419
2420 case SCTP_PARAM_IPV6_ADDRESS:
2421 asoc->peer.ipv6_address = 1;
2422 break;
2423
2424 case SCTP_PARAM_HOST_NAME_ADDRESS:
2425 asoc->peer.hostname_address = 1;
2426 break;
2427
2428 default: /* Just ignore anything else. */
2429 break;
2430 }
2431 }
2432 break;
2433
2434 case SCTP_PARAM_STATE_COOKIE:
2435 asoc->peer.cookie_len =
2436 ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
2437 asoc->peer.cookie = param.cookie->body;
2438 break;
2439
2440 case SCTP_PARAM_HEARTBEAT_INFO:
2441 /* Would be odd to receive, but it causes no problems. */
2442 break;
2443
2444 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
2445 /* Rejected during verify stage. */
2446 break;
2447
2448 case SCTP_PARAM_ECN_CAPABLE:
2449 asoc->peer.ecn_capable = 1;
2450 break;
2451
2452 case SCTP_PARAM_ADAPTATION_LAYER_IND:
2453 asoc->peer.adaptation_ind = param.aind->adaptation_ind;
2454 break;
2455
2456 case SCTP_PARAM_SET_PRIMARY:
2457 addr_param = param.v + sizeof(sctp_addip_param_t);
2458
2459 af = sctp_get_af_specific(param_type2af(param.p->type));
2460 af->from_addr_param(&addr, addr_param,
2461 htons(asoc->peer.port), 0);
2462
2463 /* if the address is invalid, we can't process it.
2464 * XXX: see spec for what to do.
2465 */
2466 if (!af->addr_valid(&addr, NULL, NULL))
2467 break;
2468
2469 t = sctp_assoc_lookup_paddr(asoc, &addr);
2470 if (!t)
2471 break;
2472
2473 sctp_assoc_set_primary(asoc, t);
2474 break;
2475
2476 case SCTP_PARAM_SUPPORTED_EXT:
2477 sctp_process_ext_param(asoc, param);
2478 break;
2479
2480 case SCTP_PARAM_FWD_TSN_SUPPORT:
2481 if (sctp_prsctp_enable) {
2482 asoc->peer.prsctp_capable = 1;
2483 break;
2484 }
2485 /* Fall Through */
2486 goto fall_through;
2487
2488 case SCTP_PARAM_RANDOM:
2489 if (!sctp_auth_enable)
2490 goto fall_through;
2491
2492 /* Save peer's random parameter */
2493 asoc->peer.peer_random = kmemdup(param.p,
2494 ntohs(param.p->length), gfp);
2495 if (!asoc->peer.peer_random) {
2496 retval = 0;
2497 break;
2498 }
2499 break;
2500
2501 case SCTP_PARAM_HMAC_ALGO:
2502 if (!sctp_auth_enable)
2503 goto fall_through;
2504
2505 /* Save peer's HMAC list */
2506 asoc->peer.peer_hmacs = kmemdup(param.p,
2507 ntohs(param.p->length), gfp);
2508 if (!asoc->peer.peer_hmacs) {
2509 retval = 0;
2510 break;
2511 }
2512
2513 /* Set the default HMAC the peer requested*/
2514 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo);
2515 break;
2516
2517 case SCTP_PARAM_CHUNKS:
2518 if (!sctp_auth_enable)
2519 goto fall_through;
2520
2521 asoc->peer.peer_chunks = kmemdup(param.p,
2522 ntohs(param.p->length), gfp);
2523 if (!asoc->peer.peer_chunks)
2524 retval = 0;
2525 break;
2526 fall_through:
2527 default:
2528 /* Any unrecognized parameters should have been caught
2529 * and handled by sctp_verify_param() which should be
2530 * called prior to this routine. Simply log the error
2531 * here.
2532 */
2533 SCTP_DEBUG_PRINTK("Ignoring param: %d for association %p.\n",
2534 ntohs(param.p->type), asoc);
2535 break;
2536 }
2537
2538 return retval;
2539 }
2540
2541 /* Select a new verification tag. */
2542 __u32 sctp_generate_tag(const struct sctp_endpoint *ep)
2543 {
2544 /* I believe that this random number generator complies with RFC1750.
2545 * A tag of 0 is reserved for special cases (e.g. INIT).
2546 */
2547 __u32 x;
2548
2549 do {
2550 get_random_bytes(&x, sizeof(__u32));
2551 } while (x == 0);
2552
2553 return x;
2554 }
2555
2556 /* Select an initial TSN to send during startup. */
2557 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep)
2558 {
2559 __u32 retval;
2560
2561 get_random_bytes(&retval, sizeof(__u32));
2562 return retval;
2563 }
2564
2565 /*
2566 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF)
2567 * 0 1 2 3
2568 * 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
2569 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2570 * | Type = 0xC1 | Chunk Flags | Chunk Length |
2571 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2572 * | Serial Number |
2573 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2574 * | Address Parameter |
2575 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2576 * | ASCONF Parameter #1 |
2577 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2578 * \ \
2579 * / .... /
2580 * \ \
2581 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2582 * | ASCONF Parameter #N |
2583 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2584 *
2585 * Address Parameter and other parameter will not be wrapped in this function
2586 */
2587 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc,
2588 union sctp_addr *addr,
2589 int vparam_len)
2590 {
2591 sctp_addiphdr_t asconf;
2592 struct sctp_chunk *retval;
2593 int length = sizeof(asconf) + vparam_len;
2594 union sctp_addr_param addrparam;
2595 int addrlen;
2596 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
2597
2598 addrlen = af->to_addr_param(addr, &addrparam);
2599 if (!addrlen)
2600 return NULL;
2601 length += addrlen;
2602
2603 /* Create the chunk. */
2604 retval = sctp_make_chunk(asoc, SCTP_CID_ASCONF, 0, length);
2605 if (!retval)
2606 return NULL;
2607
2608 asconf.serial = htonl(asoc->addip_serial++);
2609
2610 retval->subh.addip_hdr =
2611 sctp_addto_chunk(retval, sizeof(asconf), &asconf);
2612 retval->param_hdr.v =
2613 sctp_addto_chunk(retval, addrlen, &addrparam);
2614
2615 return retval;
2616 }
2617
2618 /* ADDIP
2619 * 3.2.1 Add IP Address
2620 * 0 1 2 3
2621 * 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
2622 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2623 * | Type = 0xC001 | Length = Variable |
2624 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2625 * | ASCONF-Request Correlation ID |
2626 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2627 * | Address Parameter |
2628 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2629 *
2630 * 3.2.2 Delete IP Address
2631 * 0 1 2 3
2632 * 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
2633 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2634 * | Type = 0xC002 | Length = Variable |
2635 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2636 * | ASCONF-Request Correlation ID |
2637 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2638 * | Address Parameter |
2639 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2640 *
2641 */
2642 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc,
2643 union sctp_addr *laddr,
2644 struct sockaddr *addrs,
2645 int addrcnt,
2646 __be16 flags)
2647 {
2648 sctp_addip_param_t param;
2649 struct sctp_chunk *retval;
2650 union sctp_addr_param addr_param;
2651 union sctp_addr *addr;
2652 void *addr_buf;
2653 struct sctp_af *af;
2654 int paramlen = sizeof(param);
2655 int addr_param_len = 0;
2656 int totallen = 0;
2657 int i;
2658
2659 /* Get total length of all the address parameters. */
2660 addr_buf = addrs;
2661 for (i = 0; i < addrcnt; i++) {
2662 addr = (union sctp_addr *)addr_buf;
2663 af = sctp_get_af_specific(addr->v4.sin_family);
2664 addr_param_len = af->to_addr_param(addr, &addr_param);
2665
2666 totallen += paramlen;
2667 totallen += addr_param_len;
2668
2669 addr_buf += af->sockaddr_len;
2670 }
2671
2672 /* Create an asconf chunk with the required length. */
2673 retval = sctp_make_asconf(asoc, laddr, totallen);
2674 if (!retval)
2675 return NULL;
2676
2677 /* Add the address parameters to the asconf chunk. */
2678 addr_buf = addrs;
2679 for (i = 0; i < addrcnt; i++) {
2680 addr = (union sctp_addr *)addr_buf;
2681 af = sctp_get_af_specific(addr->v4.sin_family);
2682 addr_param_len = af->to_addr_param(addr, &addr_param);
2683 param.param_hdr.type = flags;
2684 param.param_hdr.length = htons(paramlen + addr_param_len);
2685 param.crr_id = i;
2686
2687 sctp_addto_chunk(retval, paramlen, &param);
2688 sctp_addto_chunk(retval, addr_param_len, &addr_param);
2689
2690 addr_buf += af->sockaddr_len;
2691 }
2692 return retval;
2693 }
2694
2695 /* ADDIP
2696 * 3.2.4 Set Primary IP Address
2697 * 0 1 2 3
2698 * 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
2699 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2700 * | Type =0xC004 | Length = Variable |
2701 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2702 * | ASCONF-Request Correlation ID |
2703 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2704 * | Address Parameter |
2705 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2706 *
2707 * Create an ASCONF chunk with Set Primary IP address parameter.
2708 */
2709 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
2710 union sctp_addr *addr)
2711 {
2712 sctp_addip_param_t param;
2713 struct sctp_chunk *retval;
2714 int len = sizeof(param);
2715 union sctp_addr_param addrparam;
2716 int addrlen;
2717 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
2718
2719 addrlen = af->to_addr_param(addr, &addrparam);
2720 if (!addrlen)
2721 return NULL;
2722 len += addrlen;
2723
2724 /* Create the chunk and make asconf header. */
2725 retval = sctp_make_asconf(asoc, addr, len);
2726 if (!retval)
2727 return NULL;
2728
2729 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY;
2730 param.param_hdr.length = htons(len);
2731 param.crr_id = 0;
2732
2733 sctp_addto_chunk(retval, sizeof(param), &param);
2734 sctp_addto_chunk(retval, addrlen, &addrparam);
2735
2736 return retval;
2737 }
2738
2739 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK)
2740 * 0 1 2 3
2741 * 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
2742 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2743 * | Type = 0x80 | Chunk Flags | Chunk Length |
2744 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2745 * | Serial Number |
2746 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2747 * | ASCONF Parameter Response#1 |
2748 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2749 * \ \
2750 * / .... /
2751 * \ \
2752 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2753 * | ASCONF Parameter Response#N |
2754 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2755 *
2756 * Create an ASCONF_ACK chunk with enough space for the parameter responses.
2757 */
2758 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc,
2759 __u32 serial, int vparam_len)
2760 {
2761 sctp_addiphdr_t asconf;
2762 struct sctp_chunk *retval;
2763 int length = sizeof(asconf) + vparam_len;
2764
2765 /* Create the chunk. */
2766 retval = sctp_make_chunk(asoc, SCTP_CID_ASCONF_ACK, 0, length);
2767 if (!retval)
2768 return NULL;
2769
2770 asconf.serial = htonl(serial);
2771
2772 retval->subh.addip_hdr =
2773 sctp_addto_chunk(retval, sizeof(asconf), &asconf);
2774
2775 return retval;
2776 }
2777
2778 /* Add response parameters to an ASCONF_ACK chunk. */
2779 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id,
2780 __be16 err_code, sctp_addip_param_t *asconf_param)
2781 {
2782 sctp_addip_param_t ack_param;
2783 sctp_errhdr_t err_param;
2784 int asconf_param_len = 0;
2785 int err_param_len = 0;
2786 __be16 response_type;
2787
2788 if (SCTP_ERROR_NO_ERROR == err_code) {
2789 response_type = SCTP_PARAM_SUCCESS_REPORT;
2790 } else {
2791 response_type = SCTP_PARAM_ERR_CAUSE;
2792 err_param_len = sizeof(err_param);
2793 if (asconf_param)
2794 asconf_param_len =
2795 ntohs(asconf_param->param_hdr.length);
2796 }
2797
2798 /* Add Success Indication or Error Cause Indication parameter. */
2799 ack_param.param_hdr.type = response_type;
2800 ack_param.param_hdr.length = htons(sizeof(ack_param) +
2801 err_param_len +
2802 asconf_param_len);
2803 ack_param.crr_id = crr_id;
2804 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param);
2805
2806 if (SCTP_ERROR_NO_ERROR == err_code)
2807 return;
2808
2809 /* Add Error Cause parameter. */
2810 err_param.cause = err_code;
2811 err_param.length = htons(err_param_len + asconf_param_len);
2812 sctp_addto_chunk(chunk, err_param_len, &err_param);
2813
2814 /* Add the failed TLV copied from ASCONF chunk. */
2815 if (asconf_param)
2816 sctp_addto_chunk(chunk, asconf_param_len, asconf_param);
2817 }
2818
2819 /* Process a asconf parameter. */
2820 static __be16 sctp_process_asconf_param(struct sctp_association *asoc,
2821 struct sctp_chunk *asconf,
2822 sctp_addip_param_t *asconf_param)
2823 {
2824 struct sctp_transport *peer;
2825 struct sctp_af *af;
2826 union sctp_addr addr;
2827 union sctp_addr_param *addr_param;
2828
2829 addr_param = (union sctp_addr_param *)
2830 ((void *)asconf_param + sizeof(sctp_addip_param_t));
2831
2832 af = sctp_get_af_specific(param_type2af(addr_param->v4.param_hdr.type));
2833 if (unlikely(!af))
2834 return SCTP_ERROR_INV_PARAM;
2835
2836 af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0);
2837
2838 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast
2839 * or multicast address.
2840 * (note: wildcard is permitted and requires special handling so
2841 * make sure we check for that)
2842 */
2843 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb))
2844 return SCTP_ERROR_INV_PARAM;
2845
2846 switch (asconf_param->param_hdr.type) {
2847 case SCTP_PARAM_ADD_IP:
2848 /* Section 4.2.1:
2849 * If the address 0.0.0.0 or ::0 is provided, the source
2850 * address of the packet MUST be added.
2851 */
2852 if (af->is_any(&addr))
2853 memcpy(&addr, &asconf->source, sizeof(addr));
2854
2855 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address
2856 * request and does not have the local resources to add this
2857 * new address to the association, it MUST return an Error
2858 * Cause TLV set to the new error code 'Operation Refused
2859 * Due to Resource Shortage'.
2860 */
2861
2862 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED);
2863 if (!peer)
2864 return SCTP_ERROR_RSRC_LOW;
2865
2866 /* Start the heartbeat timer. */
2867 if (!mod_timer(&peer->hb_timer, sctp_transport_timeout(peer)))
2868 sctp_transport_hold(peer);
2869 break;
2870 case SCTP_PARAM_DEL_IP:
2871 /* ADDIP 4.3 D7) If a request is received to delete the
2872 * last remaining IP address of a peer endpoint, the receiver
2873 * MUST send an Error Cause TLV with the error cause set to the
2874 * new error code 'Request to Delete Last Remaining IP Address'.
2875 */
2876 if (asoc->peer.transport_count == 1)
2877 return SCTP_ERROR_DEL_LAST_IP;
2878
2879 /* ADDIP 4.3 D8) If a request is received to delete an IP
2880 * address which is also the source address of the IP packet
2881 * which contained the ASCONF chunk, the receiver MUST reject
2882 * this request. To reject the request the receiver MUST send
2883 * an Error Cause TLV set to the new error code 'Request to
2884 * Delete Source IP Address'
2885 */
2886 if (sctp_cmp_addr_exact(sctp_source(asconf), &addr))
2887 return SCTP_ERROR_DEL_SRC_IP;
2888
2889 /* Section 4.2.2
2890 * If the address 0.0.0.0 or ::0 is provided, all
2891 * addresses of the peer except the source address of the
2892 * packet MUST be deleted.
2893 */
2894 if (af->is_any(&addr)) {
2895 sctp_assoc_set_primary(asoc, asconf->transport);
2896 sctp_assoc_del_nonprimary_peers(asoc,
2897 asconf->transport);
2898 } else
2899 sctp_assoc_del_peer(asoc, &addr);
2900 break;
2901 case SCTP_PARAM_SET_PRIMARY:
2902 /* ADDIP Section 4.2.4
2903 * If the address 0.0.0.0 or ::0 is provided, the receiver
2904 * MAY mark the source address of the packet as its
2905 * primary.
2906 */
2907 if (af->is_any(&addr))
2908 memcpy(&addr.v4, sctp_source(asconf), sizeof(addr));
2909
2910 peer = sctp_assoc_lookup_paddr(asoc, &addr);
2911 if (!peer)
2912 return SCTP_ERROR_INV_PARAM;
2913
2914 sctp_assoc_set_primary(asoc, peer);
2915 break;
2916 default:
2917 return SCTP_ERROR_INV_PARAM;
2918 break;
2919 }
2920
2921 return SCTP_ERROR_NO_ERROR;
2922 }
2923
2924 /* Verify the ASCONF packet before we process it. */
2925 int sctp_verify_asconf(const struct sctp_association *asoc,
2926 struct sctp_paramhdr *param_hdr, void *chunk_end,
2927 struct sctp_paramhdr **errp) {
2928 sctp_addip_param_t *asconf_param;
2929 union sctp_params param;
2930 int length, plen;
2931
2932 param.v = (sctp_paramhdr_t *) param_hdr;
2933 while (param.v <= chunk_end - sizeof(sctp_paramhdr_t)) {
2934 length = ntohs(param.p->length);
2935 *errp = param.p;
2936
2937 if (param.v > chunk_end - length ||
2938 length < sizeof(sctp_paramhdr_t))
2939 return 0;
2940
2941 switch (param.p->type) {
2942 case SCTP_PARAM_ADD_IP:
2943 case SCTP_PARAM_DEL_IP:
2944 case SCTP_PARAM_SET_PRIMARY:
2945 asconf_param = (sctp_addip_param_t *)param.v;
2946 plen = ntohs(asconf_param->param_hdr.length);
2947 if (plen < sizeof(sctp_addip_param_t) +
2948 sizeof(sctp_paramhdr_t))
2949 return 0;
2950 break;
2951 case SCTP_PARAM_SUCCESS_REPORT:
2952 case SCTP_PARAM_ADAPTATION_LAYER_IND:
2953 if (length != sizeof(sctp_addip_param_t))
2954 return 0;
2955
2956 break;
2957 default:
2958 break;
2959 }
2960
2961 param.v += WORD_ROUND(length);
2962 }
2963
2964 if (param.v != chunk_end)
2965 return 0;
2966
2967 return 1;
2968 }
2969
2970 /* Process an incoming ASCONF chunk with the next expected serial no. and
2971 * return an ASCONF_ACK chunk to be sent in response.
2972 */
2973 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
2974 struct sctp_chunk *asconf)
2975 {
2976 sctp_addiphdr_t *hdr;
2977 union sctp_addr_param *addr_param;
2978 sctp_addip_param_t *asconf_param;
2979 struct sctp_chunk *asconf_ack;
2980
2981 __be16 err_code;
2982 int length = 0;
2983 int chunk_len;
2984 __u32 serial;
2985 int all_param_pass = 1;
2986
2987 chunk_len = ntohs(asconf->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
2988 hdr = (sctp_addiphdr_t *)asconf->skb->data;
2989 serial = ntohl(hdr->serial);
2990
2991 /* Skip the addiphdr and store a pointer to address parameter. */
2992 length = sizeof(sctp_addiphdr_t);
2993 addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
2994 chunk_len -= length;
2995
2996 /* Skip the address parameter and store a pointer to the first
2997 * asconf parameter.
2998 */
2999 length = ntohs(addr_param->v4.param_hdr.length);
3000 asconf_param = (sctp_addip_param_t *)((void *)addr_param + length);
3001 chunk_len -= length;
3002
3003 /* create an ASCONF_ACK chunk.
3004 * Based on the definitions of parameters, we know that the size of
3005 * ASCONF_ACK parameters are less than or equal to the twice of ASCONF
3006 * parameters.
3007 */
3008 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 2);
3009 if (!asconf_ack)
3010 goto done;
3011
3012 /* Process the TLVs contained within the ASCONF chunk. */
3013 while (chunk_len > 0) {
3014 err_code = sctp_process_asconf_param(asoc, asconf,
3015 asconf_param);
3016 /* ADDIP 4.1 A7)
3017 * If an error response is received for a TLV parameter,
3018 * all TLVs with no response before the failed TLV are
3019 * considered successful if not reported. All TLVs after
3020 * the failed response are considered unsuccessful unless
3021 * a specific success indication is present for the parameter.
3022 */
3023 if (SCTP_ERROR_NO_ERROR != err_code)
3024 all_param_pass = 0;
3025
3026 if (!all_param_pass)
3027 sctp_add_asconf_response(asconf_ack,
3028 asconf_param->crr_id, err_code,
3029 asconf_param);
3030
3031 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add
3032 * an IP address sends an 'Out of Resource' in its response, it
3033 * MUST also fail any subsequent add or delete requests bundled
3034 * in the ASCONF.
3035 */
3036 if (SCTP_ERROR_RSRC_LOW == err_code)
3037 goto done;
3038
3039 /* Move to the next ASCONF param. */
3040 length = ntohs(asconf_param->param_hdr.length);
3041 asconf_param = (sctp_addip_param_t *)((void *)asconf_param +
3042 length);
3043 chunk_len -= length;
3044 }
3045
3046 done:
3047 asoc->peer.addip_serial++;
3048
3049 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc
3050 * after freeing the reference to old asconf ack if any.
3051 */
3052 if (asconf_ack) {
3053 sctp_chunk_hold(asconf_ack);
3054 list_add_tail(&asconf_ack->transmitted_list,
3055 &asoc->asconf_ack_list);
3056 }
3057
3058 return asconf_ack;
3059 }
3060
3061 /* Process a asconf parameter that is successfully acked. */
3062 static int sctp_asconf_param_success(struct sctp_association *asoc,
3063 sctp_addip_param_t *asconf_param)
3064 {
3065 struct sctp_af *af;
3066 union sctp_addr addr;
3067 struct sctp_bind_addr *bp = &asoc->base.bind_addr;
3068 union sctp_addr_param *addr_param;
3069 struct list_head *pos;
3070 struct sctp_transport *transport;
3071 struct sctp_sockaddr_entry *saddr;
3072 int retval = 0;
3073
3074 addr_param = (union sctp_addr_param *)
3075 ((void *)asconf_param + sizeof(sctp_addip_param_t));
3076
3077 /* We have checked the packet before, so we do not check again. */
3078 af = sctp_get_af_specific(param_type2af(addr_param->v4.param_hdr.type));
3079 af->from_addr_param(&addr, addr_param, htons(bp->port), 0);
3080
3081 switch (asconf_param->param_hdr.type) {
3082 case SCTP_PARAM_ADD_IP:
3083 /* This is always done in BH context with a socket lock
3084 * held, so the list can not change.
3085 */
3086 local_bh_disable();
3087 list_for_each_entry(saddr, &bp->address_list, list) {
3088 if (sctp_cmp_addr_exact(&saddr->a, &addr))
3089 saddr->state = SCTP_ADDR_SRC;
3090 }
3091 local_bh_enable();
3092 break;
3093 case SCTP_PARAM_DEL_IP:
3094 local_bh_disable();
3095 retval = sctp_del_bind_addr(bp, &addr);
3096 local_bh_enable();
3097 list_for_each(pos, &asoc->peer.transport_addr_list) {
3098 transport = list_entry(pos, struct sctp_transport,
3099 transports);
3100 dst_release(transport->dst);
3101 sctp_transport_route(transport, NULL,
3102 sctp_sk(asoc->base.sk));
3103 }
3104 break;
3105 default:
3106 break;
3107 }
3108
3109 return retval;
3110 }
3111
3112 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk
3113 * for the given asconf parameter. If there is no response for this parameter,
3114 * return the error code based on the third argument 'no_err'.
3115 * ADDIP 4.1
3116 * A7) If an error response is received for a TLV parameter, all TLVs with no
3117 * response before the failed TLV are considered successful if not reported.
3118 * All TLVs after the failed response are considered unsuccessful unless a
3119 * specific success indication is present for the parameter.
3120 */
3121 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack,
3122 sctp_addip_param_t *asconf_param,
3123 int no_err)
3124 {
3125 sctp_addip_param_t *asconf_ack_param;
3126 sctp_errhdr_t *err_param;
3127 int length;
3128 int asconf_ack_len;
3129 __be16 err_code;
3130
3131 if (no_err)
3132 err_code = SCTP_ERROR_NO_ERROR;
3133 else
3134 err_code = SCTP_ERROR_REQ_REFUSED;
3135
3136 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) -
3137 sizeof(sctp_chunkhdr_t);
3138
3139 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to
3140 * the first asconf_ack parameter.
3141 */
3142 length = sizeof(sctp_addiphdr_t);
3143 asconf_ack_param = (sctp_addip_param_t *)(asconf_ack->skb->data +
3144 length);
3145 asconf_ack_len -= length;
3146
3147 while (asconf_ack_len > 0) {
3148 if (asconf_ack_param->crr_id == asconf_param->crr_id) {
3149 switch(asconf_ack_param->param_hdr.type) {
3150 case SCTP_PARAM_SUCCESS_REPORT:
3151 return SCTP_ERROR_NO_ERROR;
3152 case SCTP_PARAM_ERR_CAUSE:
3153 length = sizeof(sctp_addip_param_t);
3154 err_param = (sctp_errhdr_t *)
3155 ((void *)asconf_ack_param + length);
3156 asconf_ack_len -= length;
3157 if (asconf_ack_len > 0)
3158 return err_param->cause;
3159 else
3160 return SCTP_ERROR_INV_PARAM;
3161 break;
3162 default:
3163 return SCTP_ERROR_INV_PARAM;
3164 }
3165 }
3166
3167 length = ntohs(asconf_ack_param->param_hdr.length);
3168 asconf_ack_param = (sctp_addip_param_t *)
3169 ((void *)asconf_ack_param + length);
3170 asconf_ack_len -= length;
3171 }
3172
3173 return err_code;
3174 }
3175
3176 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */
3177 int sctp_process_asconf_ack(struct sctp_association *asoc,
3178 struct sctp_chunk *asconf_ack)
3179 {
3180 struct sctp_chunk *asconf = asoc->addip_last_asconf;
3181 union sctp_addr_param *addr_param;
3182 sctp_addip_param_t *asconf_param;
3183 int length = 0;
3184 int asconf_len = asconf->skb->len;
3185 int all_param_pass = 0;
3186 int no_err = 1;
3187 int retval = 0;
3188 __be16 err_code = SCTP_ERROR_NO_ERROR;
3189
3190 /* Skip the chunkhdr and addiphdr from the last asconf sent and store
3191 * a pointer to address parameter.
3192 */
3193 length = sizeof(sctp_addip_chunk_t);
3194 addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
3195 asconf_len -= length;
3196
3197 /* Skip the address parameter in the last asconf sent and store a
3198 * pointer to the first asconf parameter.
3199 */
3200 length = ntohs(addr_param->v4.param_hdr.length);
3201 asconf_param = (sctp_addip_param_t *)((void *)addr_param + length);
3202 asconf_len -= length;
3203
3204 /* ADDIP 4.1
3205 * A8) If there is no response(s) to specific TLV parameter(s), and no
3206 * failures are indicated, then all request(s) are considered
3207 * successful.
3208 */
3209 if (asconf_ack->skb->len == sizeof(sctp_addiphdr_t))
3210 all_param_pass = 1;
3211
3212 /* Process the TLVs contained in the last sent ASCONF chunk. */
3213 while (asconf_len > 0) {
3214 if (all_param_pass)
3215 err_code = SCTP_ERROR_NO_ERROR;
3216 else {
3217 err_code = sctp_get_asconf_response(asconf_ack,
3218 asconf_param,
3219 no_err);
3220 if (no_err && (SCTP_ERROR_NO_ERROR != err_code))
3221 no_err = 0;
3222 }
3223
3224 switch (err_code) {
3225 case SCTP_ERROR_NO_ERROR:
3226 retval = sctp_asconf_param_success(asoc, asconf_param);
3227 break;
3228
3229 case SCTP_ERROR_RSRC_LOW:
3230 retval = 1;
3231 break;
3232
3233 case SCTP_ERROR_INV_PARAM:
3234 /* Disable sending this type of asconf parameter in
3235 * future.
3236 */
3237 asoc->peer.addip_disabled_mask |=
3238 asconf_param->param_hdr.type;
3239 break;
3240
3241 case SCTP_ERROR_REQ_REFUSED:
3242 case SCTP_ERROR_DEL_LAST_IP:
3243 case SCTP_ERROR_DEL_SRC_IP:
3244 default:
3245 break;
3246 }
3247
3248 /* Skip the processed asconf parameter and move to the next
3249 * one.
3250 */
3251 length = ntohs(asconf_param->param_hdr.length);
3252 asconf_param = (sctp_addip_param_t *)((void *)asconf_param +
3253 length);
3254 asconf_len -= length;
3255 }
3256
3257 /* Free the cached last sent asconf chunk. */
3258 list_del_init(&asconf->transmitted_list);
3259 sctp_chunk_free(asconf);
3260 asoc->addip_last_asconf = NULL;
3261
3262 /* Send the next asconf chunk from the addip chunk queue. */
3263 if (!list_empty(&asoc->addip_chunk_list)) {
3264 struct list_head *entry = asoc->addip_chunk_list.next;
3265 asconf = list_entry(entry, struct sctp_chunk, list);
3266
3267 list_del_init(entry);
3268
3269 /* Hold the chunk until an ASCONF_ACK is received. */
3270 sctp_chunk_hold(asconf);
3271 if (sctp_primitive_ASCONF(asoc, asconf))
3272 sctp_chunk_free(asconf);
3273 else
3274 asoc->addip_last_asconf = asconf;
3275 }
3276
3277 return retval;
3278 }
3279
3280 /* Make a FWD TSN chunk. */
3281 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
3282 __u32 new_cum_tsn, size_t nstreams,
3283 struct sctp_fwdtsn_skip *skiplist)
3284 {
3285 struct sctp_chunk *retval = NULL;
3286 struct sctp_fwdtsn_chunk *ftsn_chunk;
3287 struct sctp_fwdtsn_hdr ftsn_hdr;
3288 struct sctp_fwdtsn_skip skip;
3289 size_t hint;
3290 int i;
3291
3292 hint = (nstreams + 1) * sizeof(__u32);
3293
3294 retval = sctp_make_chunk(asoc, SCTP_CID_FWD_TSN, 0, hint);
3295
3296 if (!retval)
3297 return NULL;
3298
3299 ftsn_chunk = (struct sctp_fwdtsn_chunk *)retval->subh.fwdtsn_hdr;
3300
3301 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn);
3302 retval->subh.fwdtsn_hdr =
3303 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr);
3304
3305 for (i = 0; i < nstreams; i++) {
3306 skip.stream = skiplist[i].stream;
3307 skip.ssn = skiplist[i].ssn;
3308 sctp_addto_chunk(retval, sizeof(skip), &skip);
3309 }
3310
3311 return retval;
3312 }
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