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Linux-2.6.12-rc2
[linux-2.6-block.git] / net / sctp / sm_make_chunk.c
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1da177e4
LT		 1/* SCTP kernel reference 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 reference 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 * The SCTP reference 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 * The SCTP reference 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 <asm/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
68extern kmem_cache_t *sctp_chunk_cachep;
69
70SCTP_STATIC
71struct sctp_chunk *sctp_make_chunk(const struct sctp_association *asoc,
72 __u8 type, __u8 flags, int paylen);
73static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep,
74 const struct sctp_association *asoc,
75 const struct sctp_chunk *init_chunk,
76 int *cookie_len,
77 const __u8 *raw_addrs, int addrs_len);
78static int sctp_process_param(struct sctp_association *asoc,
79 union sctp_params param,
80 const union sctp_addr *peer_addr,
81 int gfp);
82
83/* What was the inbound interface for this chunk? */
84int 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(chunk->skb->nh.iph->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 */
101static const struct sctp_paramhdr ecap_param = {
102 SCTP_PARAM_ECN_CAPABLE,
103 __constant_htons(sizeof(struct sctp_paramhdr)),
104};
105static 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 */
114void sctp_init_cause(struct sctp_chunk *chunk, __u16 cause_code,
115 const void *payload, size_t paylen)
116{
117 sctp_errhdr_t err;
118 int padlen;
119 __u16 len;
120
121 /* Cause code constants are now defined in network order. */
122 err.cause = cause_code;
123 len = sizeof(sctp_errhdr_t) + paylen;
124 padlen = len % 4;
125 err.length = htons(len);
126 len += padlen;
127 sctp_addto_chunk(chunk, sizeof(sctp_errhdr_t), &err);
128 chunk->subh.err_hdr = sctp_addto_chunk(chunk, paylen, payload);
129}
130
131/* 3.3.2 Initiation (INIT) (1)
132 *
133 * This chunk is used to initiate a SCTP association between two
134 * endpoints. The format of the INIT chunk is shown below:
135 *
136 * 0 1 2 3
137 * 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
138 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
139 * | Type = 1 | Chunk Flags | Chunk Length |
140 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
141 * | Initiate Tag |
142 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
143 * | Advertised Receiver Window Credit (a_rwnd) |
144 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
145 * | Number of Outbound Streams | Number of Inbound Streams |
146 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
147 * | Initial TSN |
148 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
149 * \ \
150 * / Optional/Variable-Length Parameters /
151 * \ \
152 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
153 *
154 *
155 * The INIT chunk contains the following parameters. Unless otherwise
156 * noted, each parameter MUST only be included once in the INIT chunk.
157 *
158 * Fixed Parameters Status
159 * ----------------------------------------------
160 * Initiate Tag Mandatory
161 * Advertised Receiver Window Credit Mandatory
162 * Number of Outbound Streams Mandatory
163 * Number of Inbound Streams Mandatory
164 * Initial TSN Mandatory
165 *
166 * Variable Parameters Status Type Value
167 * -------------------------------------------------------------
168 * IPv4 Address (Note 1) Optional 5
169 * IPv6 Address (Note 1) Optional 6
170 * Cookie Preservative Optional 9
171 * Reserved for ECN Capable (Note 2) Optional 32768 (0x8000)
172 * Host Name Address (Note 3) Optional 11
173 * Supported Address Types (Note 4) Optional 12
174 */
175struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc,
176 const struct sctp_bind_addr *bp,
177 int gfp, int vparam_len)
178{
179 sctp_inithdr_t init;
180 union sctp_params addrs;
181 size_t chunksize;
182 struct sctp_chunk *retval = NULL;
183 int num_types, addrs_len = 0;
184 struct sctp_sock *sp;
185 sctp_supported_addrs_param_t sat;
186 __u16 types[2];
187 sctp_adaption_ind_param_t aiparam;
188
189 /* RFC 2960 3.3.2 Initiation (INIT) (1)
190 *
191 * Note 1: The INIT chunks can contain multiple addresses that
192 * can be IPv4 and/or IPv6 in any combination.
193 */
194 retval = NULL;
195
196 /* Convert the provided bind address list to raw format. */
197 addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp);
198
199 init.init_tag = htonl(asoc->c.my_vtag);
200 init.a_rwnd = htonl(asoc->rwnd);
201 init.num_outbound_streams = htons(asoc->c.sinit_num_ostreams);
202 init.num_inbound_streams = htons(asoc->c.sinit_max_instreams);
203 init.initial_tsn = htonl(asoc->c.initial_tsn);
204
205 /* How many address types are needed? */
206 sp = sctp_sk(asoc->base.sk);
207 num_types = sp->pf->supported_addrs(sp, types);
208
209 chunksize = sizeof(init) + addrs_len + SCTP_SAT_LEN(num_types);
210 chunksize += sizeof(ecap_param);
211 if (sctp_prsctp_enable)
212 chunksize += sizeof(prsctp_param);
213 chunksize += sizeof(aiparam);
214 chunksize += vparam_len;
215
216 /* RFC 2960 3.3.2 Initiation (INIT) (1)
217 *
218 * Note 3: An INIT chunk MUST NOT contain more than one Host
219 * Name address parameter. Moreover, the sender of the INIT
220 * MUST NOT combine any other address types with the Host Name
221 * address in the INIT. The receiver of INIT MUST ignore any
222 * other address types if the Host Name address parameter is
223 * present in the received INIT chunk.
224 *
225 * PLEASE DO NOT FIXME [This version does not support Host Name.]
226 */
227
228 retval = sctp_make_chunk(asoc, SCTP_CID_INIT, 0, chunksize);
229 if (!retval)
230 goto nodata;
231
232 retval->subh.init_hdr =
233 sctp_addto_chunk(retval, sizeof(init), &init);
234 retval->param_hdr.v =
235 sctp_addto_chunk(retval, addrs_len, addrs.v);
236
237 /* RFC 2960 3.3.2 Initiation (INIT) (1)
238 *
239 * Note 4: This parameter, when present, specifies all the
240 * address types the sending endpoint can support. The absence
241 * of this parameter indicates that the sending endpoint can
242 * support any address type.
243 */
244 sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES;
245 sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types));
246 sctp_addto_chunk(retval, sizeof(sat), &sat);
247 sctp_addto_chunk(retval, num_types * sizeof(__u16), &types);
248
249 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
250 if (sctp_prsctp_enable)
251 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
252 aiparam.param_hdr.type = SCTP_PARAM_ADAPTION_LAYER_IND;
253 aiparam.param_hdr.length = htons(sizeof(aiparam));
254 aiparam.adaption_ind = htonl(sp->adaption_ind);
255 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
256nodata:
257 if (addrs.v)
258 kfree(addrs.v);
259 return retval;
260}
261
262struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc,
263 const struct sctp_chunk *chunk,
264 int gfp, int unkparam_len)
265{
266 sctp_inithdr_t initack;
267 struct sctp_chunk *retval;
268 union sctp_params addrs;
269 int addrs_len;
270 sctp_cookie_param_t *cookie;
271 int cookie_len;
272 size_t chunksize;
273 sctp_adaption_ind_param_t aiparam;
274
275 retval = NULL;
276
277 /* Note: there may be no addresses to embed. */
278 addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp);
279
280 initack.init_tag = htonl(asoc->c.my_vtag);
281 initack.a_rwnd = htonl(asoc->rwnd);
282 initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams);
283 initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams);
284 initack.initial_tsn = htonl(asoc->c.initial_tsn);
285
286 /* FIXME: We really ought to build the cookie right
287 * into the packet instead of allocating more fresh memory.
288 */
289 cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len,
290 addrs.v, addrs_len);
291 if (!cookie)
292 goto nomem_cookie;
293
294 /* Calculate the total size of allocation, include the reserved
295 * space for reporting unknown parameters if it is specified.
296 */
297 chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len;
298
299 /* Tell peer that we'll do ECN only if peer advertised such cap. */
300 if (asoc->peer.ecn_capable)
301 chunksize += sizeof(ecap_param);
302
303 /* Tell peer that we'll do PR-SCTP only if peer advertised. */
304 if (asoc->peer.prsctp_capable)
305 chunksize += sizeof(prsctp_param);
306
307 chunksize += sizeof(aiparam);
308
309 /* Now allocate and fill out the chunk. */
310 retval = sctp_make_chunk(asoc, SCTP_CID_INIT_ACK, 0, chunksize);
311 if (!retval)
312 goto nomem_chunk;
313
314 /* Per the advice in RFC 2960 6.4, send this reply to
315 * the source of the INIT packet.
316 */
317 retval->transport = chunk->transport;
318 retval->subh.init_hdr =
319 sctp_addto_chunk(retval, sizeof(initack), &initack);
320 retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v);
321 sctp_addto_chunk(retval, cookie_len, cookie);
322 if (asoc->peer.ecn_capable)
323 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
324 if (asoc->peer.prsctp_capable)
325 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
326
327 aiparam.param_hdr.type = SCTP_PARAM_ADAPTION_LAYER_IND;
328 aiparam.param_hdr.length = htons(sizeof(aiparam));
329 aiparam.adaption_ind = htonl(sctp_sk(asoc->base.sk)->adaption_ind);
330 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
331
332 /* We need to remove the const qualifier at this point. */
333 retval->asoc = (struct sctp_association *) asoc;
334
335 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
336 *
337 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
338 * HEARTBEAT ACK, * etc.) to the same destination transport
339 * address from which it received the DATA or control chunk
340 * to which it is replying.
341 *
342 * [INIT ACK back to where the INIT came from.]
343 */
344 if (chunk)
345 retval->transport = chunk->transport;
346
347nomem_chunk:
348 kfree(cookie);
349nomem_cookie:
350 if (addrs.v)
351 kfree(addrs.v);
352 return retval;
353}
354
355/* 3.3.11 Cookie Echo (COOKIE ECHO) (10):
356 *
357 * This chunk is used only during the initialization of an association.
358 * It is sent by the initiator of an association to its peer to complete
359 * the initialization process. This chunk MUST precede any DATA chunk
360 * sent within the association, but MAY be bundled with one or more DATA
361 * chunks in the same packet.
362 *
363 * 0 1 2 3
364 * 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
365 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
366 * | Type = 10 |Chunk Flags | Length |
367 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
368 * / Cookie /
369 * \ \
370 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
371 *
372 * Chunk Flags: 8 bit
373 *
374 * Set to zero on transmit and ignored on receipt.
375 *
376 * Length: 16 bits (unsigned integer)
377 *
378 * Set to the size of the chunk in bytes, including the 4 bytes of
379 * the chunk header and the size of the Cookie.
380 *
381 * Cookie: variable size
382 *
383 * This field must contain the exact cookie received in the
384 * State Cookie parameter from the previous INIT ACK.
385 *
386 * An implementation SHOULD make the cookie as small as possible
387 * to insure interoperability.
388 */
389struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc,
390 const struct sctp_chunk *chunk)
391{
392 struct sctp_chunk *retval;
393 void *cookie;
394 int cookie_len;
395
396 cookie = asoc->peer.cookie;
397 cookie_len = asoc->peer.cookie_len;
398
399 /* Build a cookie echo chunk. */
400 retval = sctp_make_chunk(asoc, SCTP_CID_COOKIE_ECHO, 0, cookie_len);
401 if (!retval)
402 goto nodata;
403 retval->subh.cookie_hdr =
404 sctp_addto_chunk(retval, cookie_len, cookie);
405
406 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
407 *
408 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
409 * HEARTBEAT ACK, * etc.) to the same destination transport
410 * address from which it * received the DATA or control chunk
411 * to which it is replying.
412 *
413 * [COOKIE ECHO back to where the INIT ACK came from.]
414 */
415 if (chunk)
416 retval->transport = chunk->transport;
417
418nodata:
419 return retval;
420}
421
422/* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11):
423 *
424 * This chunk is used only during the initialization of an
425 * association. It is used to acknowledge the receipt of a COOKIE
426 * ECHO chunk. This chunk MUST precede any DATA or SACK chunk sent
427 * within the association, but MAY be bundled with one or more DATA
428 * chunks or SACK chunk in the same SCTP packet.
429 *
430 * 0 1 2 3
431 * 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
432 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
433 * | Type = 11 |Chunk Flags | Length = 4 |
434 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
435 *
436 * Chunk Flags: 8 bits
437 *
438 * Set to zero on transmit and ignored on receipt.
439 */
440struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc,
441 const struct sctp_chunk *chunk)
442{
443 struct sctp_chunk *retval;
444
445 retval = sctp_make_chunk(asoc, SCTP_CID_COOKIE_ACK, 0, 0);
446
447 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
448 *
449 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
450 * HEARTBEAT ACK, * etc.) to the same destination transport
451 * address from which it * received the DATA or control chunk
452 * to which it is replying.
453 *
454 * [COOKIE ACK back to where the COOKIE ECHO came from.]
455 */
456 if (retval && chunk)
457 retval->transport = chunk->transport;
458
459 return retval;
460}
461
462/*
463 * Appendix A: Explicit Congestion Notification:
464 * CWR:
465 *
466 * RFC 2481 details a specific bit for a sender to send in the header of
467 * its next outbound TCP segment to indicate to its peer that it has
468 * reduced its congestion window. This is termed the CWR bit. For
469 * SCTP the same indication is made by including the CWR chunk.
470 * This chunk contains one data element, i.e. the TSN number that
471 * was sent in the ECNE chunk. This element represents the lowest
472 * TSN number in the datagram that was originally marked with the
473 * CE bit.
474 *
475 * 0 1 2 3
476 * 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
477 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
478 * | Chunk Type=13 | Flags=00000000| Chunk Length = 8 |
479 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
480 * | Lowest TSN Number |
481 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
482 *
483 * Note: The CWR is considered a Control chunk.
484 */
485struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc,
486 const __u32 lowest_tsn,
487 const struct sctp_chunk *chunk)
488{
489 struct sctp_chunk *retval;
490 sctp_cwrhdr_t cwr;
491
492 cwr.lowest_tsn = htonl(lowest_tsn);
493 retval = sctp_make_chunk(asoc, SCTP_CID_ECN_CWR, 0,
494 sizeof(sctp_cwrhdr_t));
495
496 if (!retval)
497 goto nodata;
498
499 retval->subh.ecn_cwr_hdr =
500 sctp_addto_chunk(retval, sizeof(cwr), &cwr);
501
502 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
503 *
504 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
505 * HEARTBEAT ACK, * etc.) to the same destination transport
506 * address from which it * received the DATA or control chunk
507 * to which it is replying.
508 *
509 * [Report a reduced congestion window back to where the ECNE
510 * came from.]
511 */
512 if (chunk)
513 retval->transport = chunk->transport;
514
515nodata:
516 return retval;
517}
518
519/* Make an ECNE chunk. This is a congestion experienced report. */
520struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc,
521 const __u32 lowest_tsn)
522{
523 struct sctp_chunk *retval;
524 sctp_ecnehdr_t ecne;
525
526 ecne.lowest_tsn = htonl(lowest_tsn);
527 retval = sctp_make_chunk(asoc, SCTP_CID_ECN_ECNE, 0,
528 sizeof(sctp_ecnehdr_t));
529 if (!retval)
530 goto nodata;
531 retval->subh.ecne_hdr =
532 sctp_addto_chunk(retval, sizeof(ecne), &ecne);
533
534nodata:
535 return retval;
536}
537
538/* Make a DATA chunk for the given association from the provided
539 * parameters. However, do not populate the data payload.
540 */
541struct sctp_chunk *sctp_make_datafrag_empty(struct sctp_association *asoc,
542 const struct sctp_sndrcvinfo *sinfo,
543 int data_len, __u8 flags, __u16 ssn)
544{
545 struct sctp_chunk *retval;
546 struct sctp_datahdr dp;
547 int chunk_len;
548
549 /* We assign the TSN as LATE as possible, not here when
550 * creating the chunk.
551 */
552 dp.tsn = 0;
553 dp.stream = htons(sinfo->sinfo_stream);
554 dp.ppid = sinfo->sinfo_ppid;
555
556 /* Set the flags for an unordered send. */
557 if (sinfo->sinfo_flags & MSG_UNORDERED) {
558 flags |= SCTP_DATA_UNORDERED;
559 dp.ssn = 0;
560 } else
561 dp.ssn = htons(ssn);
562
563 chunk_len = sizeof(dp) + data_len;
564 retval = sctp_make_chunk(asoc, SCTP_CID_DATA, flags, chunk_len);
565 if (!retval)
566 goto nodata;
567
568 retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp);
569 memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo));
570
571nodata:
572 return retval;
573}
574
575/* Create a selective ackowledgement (SACK) for the given
576 * association. This reports on which TSN's we've seen to date,
577 * including duplicates and gaps.
578 */
579struct sctp_chunk *sctp_make_sack(const struct sctp_association *asoc)
580{
581 struct sctp_chunk *retval;
582 struct sctp_sackhdr sack;
583 int len;
584 __u32 ctsn;
585 __u16 num_gabs, num_dup_tsns;
586 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
587
588 ctsn = sctp_tsnmap_get_ctsn(map);
589 SCTP_DEBUG_PRINTK("sackCTSNAck sent: 0x%x.\n", ctsn);
590
591 /* How much room is needed in the chunk? */
592 num_gabs = sctp_tsnmap_num_gabs(map);
593 num_dup_tsns = sctp_tsnmap_num_dups(map);
594
595 /* Initialize the SACK header. */
596 sack.cum_tsn_ack = htonl(ctsn);
597 sack.a_rwnd = htonl(asoc->a_rwnd);
598 sack.num_gap_ack_blocks = htons(num_gabs);
599 sack.num_dup_tsns = htons(num_dup_tsns);
600
601 len = sizeof(sack)
602 + sizeof(struct sctp_gap_ack_block) * num_gabs
603 + sizeof(__u32) * num_dup_tsns;
604
605 /* Create the chunk. */
606 retval = sctp_make_chunk(asoc, SCTP_CID_SACK, 0, len);
607 if (!retval)
608 goto nodata;
609
610 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
611 *
612 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
613 * HEARTBEAT ACK, etc.) to the same destination transport
614 * address from which it received the DATA or control chunk to
615 * which it is replying. This rule should also be followed if
616 * the endpoint is bundling DATA chunks together with the
617 * reply chunk.
618 *
619 * However, when acknowledging multiple DATA chunks received
620 * in packets from different source addresses in a single
621 * SACK, the SACK chunk may be transmitted to one of the
622 * destination transport addresses from which the DATA or
623 * control chunks being acknowledged were received.
624 *
625 * [BUG: We do not implement the following paragraph.
626 * Perhaps we should remember the last transport we used for a
627 * SACK and avoid that (if possible) if we have seen any
628 * duplicates. --piggy]
629 *
630 * When a receiver of a duplicate DATA chunk sends a SACK to a
631 * multi- homed endpoint it MAY be beneficial to vary the
632 * destination address and not use the source address of the
633 * DATA chunk. The reason being that receiving a duplicate
634 * from a multi-homed endpoint might indicate that the return
635 * path (as specified in the source address of the DATA chunk)
636 * for the SACK is broken.
637 *
638 * [Send to the address from which we last received a DATA chunk.]
639 */
640 retval->transport = asoc->peer.last_data_from;
641
642 retval->subh.sack_hdr =
643 sctp_addto_chunk(retval, sizeof(sack), &sack);
644
645 /* Add the gap ack block information. */
646 if (num_gabs)
647 sctp_addto_chunk(retval, sizeof(__u32) * num_gabs,
648 sctp_tsnmap_get_gabs(map));
649
650 /* Add the duplicate TSN information. */
651 if (num_dup_tsns)
652 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns,
653 sctp_tsnmap_get_dups(map));
654
655nodata:
656 return retval;
657}
658
659/* Make a SHUTDOWN chunk. */
660struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc,
661 const struct sctp_chunk *chunk)
662{
663 struct sctp_chunk *retval;
664 sctp_shutdownhdr_t shut;
665 __u32 ctsn;
666
667 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
668 shut.cum_tsn_ack = htonl(ctsn);
669
670 retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN, 0,
671 sizeof(sctp_shutdownhdr_t));
672 if (!retval)
673 goto nodata;
674
675 retval->subh.shutdown_hdr =
676 sctp_addto_chunk(retval, sizeof(shut), &shut);
677
678 if (chunk)
679 retval->transport = chunk->transport;
680nodata:
681 return retval;
682}
683
684struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc,
685 const struct sctp_chunk *chunk)
686{
687 struct sctp_chunk *retval;
688
689 retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0);
690
691 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
692 *
693 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
694 * HEARTBEAT ACK, * etc.) to the same destination transport
695 * address from which it * received the DATA or control chunk
696 * to which it is replying.
697 *
698 * [ACK back to where the SHUTDOWN came from.]
699 */
700 if (retval && chunk)
701 retval->transport = chunk->transport;
702
703 return retval;
704}
705
706struct sctp_chunk *sctp_make_shutdown_complete(
707 const struct sctp_association *asoc,
708 const struct sctp_chunk *chunk)
709{
710 struct sctp_chunk *retval;
711 __u8 flags = 0;
712
713 /* Maybe set the T-bit if we have no association. */
714 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T;
715
716 retval = sctp_make_chunk(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 0);
717
718 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
719 *
720 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
721 * HEARTBEAT ACK, * etc.) to the same destination transport
722 * address from which it * received the DATA or control chunk
723 * to which it is replying.
724 *
725 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK
726 * came from.]
727 */
728 if (retval && chunk)
729 retval->transport = chunk->transport;
730
731 return retval;
732}
733
734/* Create an ABORT. Note that we set the T bit if we have no
735 * association.
736 */
737struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc,
738 const struct sctp_chunk *chunk,
739 const size_t hint)
740{
741 struct sctp_chunk *retval;
742 __u8 flags = 0;
743
744 /* Maybe set the T-bit if we have no association. */
745 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T;
746
747 retval = sctp_make_chunk(asoc, SCTP_CID_ABORT, flags, hint);
748
749 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
750 *
751 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
752 * HEARTBEAT ACK, * etc.) to the same destination transport
753 * address from which it * received the DATA or control chunk
754 * to which it is replying.
755 *
756 * [ABORT back to where the offender came from.]
757 */
758 if (retval && chunk)
759 retval->transport = chunk->transport;
760
761 return retval;
762}
763
764/* Helper to create ABORT with a NO_USER_DATA error. */
765struct sctp_chunk *sctp_make_abort_no_data(
766 const struct sctp_association *asoc,
767 const struct sctp_chunk *chunk, __u32 tsn)
768{
769 struct sctp_chunk *retval;
770 __u32 payload;
771
772 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t)
773 + sizeof(tsn));
774
775 if (!retval)
776 goto no_mem;
777
778 /* Put the tsn back into network byte order. */
779 payload = htonl(tsn);
780 sctp_init_cause(retval, SCTP_ERROR_NO_DATA, (const void *)&payload,
781 sizeof(payload));
782
783 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
784 *
785 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
786 * HEARTBEAT ACK, * etc.) to the same destination transport
787 * address from which it * received the DATA or control chunk
788 * to which it is replying.
789 *
790 * [ABORT back to where the offender came from.]
791 */
792 if (chunk)
793 retval->transport = chunk->transport;
794
795no_mem:
796 return retval;
797}
798
799/* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */
800struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc,
801 const struct sctp_chunk *chunk,
802 const struct msghdr *msg)
803{
804 struct sctp_chunk *retval;
805 void *payload = NULL, *payoff;
806 size_t paylen = 0;
807 struct iovec *iov = NULL;
808 int iovlen = 0;
809
810 if (msg) {
811 iov = msg->msg_iov;
812 iovlen = msg->msg_iovlen;
813 paylen = get_user_iov_size(iov, iovlen);
814 }
815
816 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) + paylen);
817 if (!retval)
818 goto err_chunk;
819
820 if (paylen) {
821 /* Put the msg_iov together into payload. */
822 payload = kmalloc(paylen, GFP_ATOMIC);
823 if (!payload)
824 goto err_payload;
825 payoff = payload;
826
827 for (; iovlen > 0; --iovlen) {
828 if (copy_from_user(payoff, iov->iov_base,iov->iov_len))
829 goto err_copy;
830 payoff += iov->iov_len;
831 iov++;
832 }
833 }
834
835 sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, payload, paylen);
836
837 if (paylen)
838 kfree(payload);
839
840 return retval;
841
842err_copy:
843 kfree(payload);
844err_payload:
845 sctp_chunk_free(retval);
846 retval = NULL;
847err_chunk:
848 return retval;
849}
850
851/* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */
852struct sctp_chunk *sctp_make_abort_violation(
853 const struct sctp_association *asoc,
854 const struct sctp_chunk *chunk,
855 const __u8 *payload,
856 const size_t paylen)
857{
858 struct sctp_chunk *retval;
859 struct sctp_paramhdr phdr;
860
861 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) + paylen
862 + sizeof(sctp_chunkhdr_t));
863 if (!retval)
864 goto end;
865
866 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, payload, paylen);
867
868 phdr.type = htons(chunk->chunk_hdr->type);
869 phdr.length = chunk->chunk_hdr->length;
870 sctp_addto_chunk(retval, sizeof(sctp_paramhdr_t), &phdr);
871
872end:
873 return retval;
874}
875
876/* Make a HEARTBEAT chunk. */
877struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc,
878 const struct sctp_transport *transport,
879 const void *payload, const size_t paylen)
880{
881 struct sctp_chunk *retval = sctp_make_chunk(asoc, SCTP_CID_HEARTBEAT,
882 0, paylen);
883
884 if (!retval)
885 goto nodata;
886
887 /* Cast away the 'const', as this is just telling the chunk
888 * what transport it belongs to.
889 */
890 retval->transport = (struct sctp_transport *) transport;
891 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload);
892
893nodata:
894 return retval;
895}
896
897struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc,
898 const struct sctp_chunk *chunk,
899 const void *payload, const size_t paylen)
900{
901 struct sctp_chunk *retval;
902
903 retval = sctp_make_chunk(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen);
904 if (!retval)
905 goto nodata;
906
907 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload);
908
909 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
910 *
911 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
912 * HEARTBEAT ACK, * etc.) to the same destination transport
913 * address from which it * received the DATA or control chunk
914 * to which it is replying.
915 *
916 * [HBACK back to where the HEARTBEAT came from.]
917 */
918 if (chunk)
919 retval->transport = chunk->transport;
920
921nodata:
922 return retval;
923}
924
925/* Create an Operation Error chunk with the specified space reserved.
926 * This routine can be used for containing multiple causes in the chunk.
927 */
928static struct sctp_chunk *sctp_make_op_error_space(
929 const struct sctp_association *asoc,
930 const struct sctp_chunk *chunk,
931 size_t size)
932{
933 struct sctp_chunk *retval;
934
935 retval = sctp_make_chunk(asoc, SCTP_CID_ERROR, 0,
936 sizeof(sctp_errhdr_t) + size);
937 if (!retval)
938 goto nodata;
939
940 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
941 *
942 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
943 * HEARTBEAT ACK, etc.) to the same destination transport
944 * address from which it received the DATA or control chunk
945 * to which it is replying.
946 *
947 */
948 if (chunk)
949 retval->transport = chunk->transport;
950
951nodata:
952 return retval;
953}
954
955/* Create an Operation Error chunk. */
956struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc,
957 const struct sctp_chunk *chunk,
958 __u16 cause_code, const void *payload,
959 size_t paylen)
960{
961 struct sctp_chunk *retval;
962
963 retval = sctp_make_op_error_space(asoc, chunk, paylen);
964 if (!retval)
965 goto nodata;
966
967 sctp_init_cause(retval, cause_code, payload, paylen);
968
969nodata:
970 return retval;
971}
972
973/********************************************************************
974 * 2nd Level Abstractions
975 ********************************************************************/
976
977/* Turn an skb into a chunk.
978 * FIXME: Eventually move the structure directly inside the skb->cb[].
979 */
980struct sctp_chunk *sctp_chunkify(struct sk_buff *skb,
981 const struct sctp_association *asoc,
982 struct sock *sk)
983{
984 struct sctp_chunk *retval;
985
986 retval = kmem_cache_alloc(sctp_chunk_cachep, SLAB_ATOMIC);
987
988 if (!retval)
989 goto nodata;
990 memset(retval, 0, sizeof(struct sctp_chunk));
991
992 if (!sk) {
993 SCTP_DEBUG_PRINTK("chunkifying skb %p w/o an sk\n", skb);
994 }
995
996 retval->skb = skb;
997 retval->asoc = (struct sctp_association *)asoc;
998 retval->resent = 0;
999 retval->has_tsn = 0;
1000 retval->has_ssn = 0;
1001 retval->rtt_in_progress = 0;
1002 retval->sent_at = 0;
1003 retval->singleton = 1;
1004 retval->end_of_packet = 0;
1005 retval->ecn_ce_done = 0;
1006 retval->pdiscard = 0;
1007
1008 /* sctpimpguide-05.txt Section 2.8.2
1009 * M1) Each time a new DATA chunk is transmitted
1010 * set the 'TSN.Missing.Report' count for that TSN to 0. The
1011 * 'TSN.Missing.Report' count will be used to determine missing chunks
1012 * and when to fast retransmit.
1013 */
1014 retval->tsn_missing_report = 0;
1015 retval->tsn_gap_acked = 0;
1016 retval->fast_retransmit = 0;
1017
1018 /* If this is a fragmented message, track all fragments
1019 * of the message (for SEND_FAILED).
1020 */
1021 retval->msg = NULL;
1022
1023 /* Polish the bead hole. */
1024 INIT_LIST_HEAD(&retval->transmitted_list);
1025 INIT_LIST_HEAD(&retval->frag_list);
1026 SCTP_DBG_OBJCNT_INC(chunk);
1027 atomic_set(&retval->refcnt, 1);
1028
1029nodata:
1030 return retval;
1031}
1032
1033/* Set chunk->source and dest based on the IP header in chunk->skb. */
1034void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src,
1035 union sctp_addr *dest)
1036{
1037 memcpy(&chunk->source, src, sizeof(union sctp_addr));
1038 memcpy(&chunk->dest, dest, sizeof(union sctp_addr));
1039}
1040
1041/* Extract the source address from a chunk. */
1042const union sctp_addr *sctp_source(const struct sctp_chunk *chunk)
1043{
1044 /* If we have a known transport, use that. */
1045 if (chunk->transport) {
1046 return &chunk->transport->ipaddr;
1047 } else {
1048 /* Otherwise, extract it from the IP header. */
1049 return &chunk->source;
1050 }
1051}
1052
1053/* Create a new chunk, setting the type and flags headers from the
1054 * arguments, reserving enough space for a 'paylen' byte payload.
1055 */
1056SCTP_STATIC
1057struct sctp_chunk *sctp_make_chunk(const struct sctp_association *asoc,
1058 __u8 type, __u8 flags, int paylen)
1059{
1060 struct sctp_chunk *retval;
1061 sctp_chunkhdr_t *chunk_hdr;
1062 struct sk_buff *skb;
1063 struct sock *sk;
1064
1065 /* No need to allocate LL here, as this is only a chunk. */
1066 skb = alloc_skb(WORD_ROUND(sizeof(sctp_chunkhdr_t) + paylen),
1067 GFP_ATOMIC);
1068 if (!skb)
1069 goto nodata;
1070
1071 /* Make room for the chunk header. */
1072 chunk_hdr = (sctp_chunkhdr_t *)skb_put(skb, sizeof(sctp_chunkhdr_t));
1073 chunk_hdr->type = type;
1074 chunk_hdr->flags = flags;
1075 chunk_hdr->length = htons(sizeof(sctp_chunkhdr_t));
1076
1077 sk = asoc ? asoc->base.sk : NULL;
1078 retval = sctp_chunkify(skb, asoc, sk);
1079 if (!retval) {
1080 kfree_skb(skb);
1081 goto nodata;
1082 }
1083
1084 retval->chunk_hdr = chunk_hdr;
1085 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(struct sctp_chunkhdr);
1086
1087 /* Set the skb to the belonging sock for accounting. */
1088 skb->sk = sk;
1089
1090 return retval;
1091nodata:
1092 return NULL;
1093}
1094
1095
1096/* Release the memory occupied by a chunk. */
1097static void sctp_chunk_destroy(struct sctp_chunk *chunk)
1098{
1099 /* Free the chunk skb data and the SCTP_chunk stub itself. */
1100 dev_kfree_skb(chunk->skb);
1101
1102 SCTP_DBG_OBJCNT_DEC(chunk);
1103 kmem_cache_free(sctp_chunk_cachep, chunk);
1104}
1105
1106/* Possibly, free the chunk. */
1107void sctp_chunk_free(struct sctp_chunk *chunk)
1108{
1109 /* Make sure that we are not on any list. */
1110 skb_unlink((struct sk_buff *) chunk);
1111 list_del_init(&chunk->transmitted_list);
1112
1113 /* Release our reference on the message tracker. */
1114 if (chunk->msg)
1115 sctp_datamsg_put(chunk->msg);
1116
1117 sctp_chunk_put(chunk);
1118}
1119
1120/* Grab a reference to the chunk. */
1121void sctp_chunk_hold(struct sctp_chunk *ch)
1122{
1123 atomic_inc(&ch->refcnt);
1124}
1125
1126/* Release a reference to the chunk. */
1127void sctp_chunk_put(struct sctp_chunk *ch)
1128{
1129 if (atomic_dec_and_test(&ch->refcnt))
1130 sctp_chunk_destroy(ch);
1131}
1132
1133/* Append bytes to the end of a chunk. Will panic if chunk is not big
1134 * enough.
1135 */
1136void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data)
1137{
1138 void *target;
1139 void *padding;
1140 int chunklen = ntohs(chunk->chunk_hdr->length);
1141 int padlen = chunklen % 4;
1142
1143 padding = skb_put(chunk->skb, padlen);
1144 target = skb_put(chunk->skb, len);
1145
1146 memset(padding, 0, padlen);
1147 memcpy(target, data, len);
1148
1149 /* Adjust the chunk length field. */
1150 chunk->chunk_hdr->length = htons(chunklen + padlen + len);
1151 chunk->chunk_end = chunk->skb->tail;
1152
1153 return target;
1154}
1155
1156/* Append bytes from user space to the end of a chunk. Will panic if
1157 * chunk is not big enough.
1158 * Returns a kernel err value.
1159 */
1160int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len,
1161 struct iovec *data)
1162{
1163 __u8 *target;
1164 int err = 0;
1165
1166 /* Make room in chunk for data. */
1167 target = skb_put(chunk->skb, len);
1168
1169 /* Copy data (whole iovec) into chunk */
1170 if ((err = memcpy_fromiovecend(target, data, off, len)))
1171 goto out;
1172
1173 /* Adjust the chunk length field. */
1174 chunk->chunk_hdr->length =
1175 htons(ntohs(chunk->chunk_hdr->length) + len);
1176 chunk->chunk_end = chunk->skb->tail;
1177
1178out:
1179 return err;
1180}
1181
1182/* Helper function to assign a TSN if needed. This assumes that both
1183 * the data_hdr and association have already been assigned.
1184 */
1185void sctp_chunk_assign_ssn(struct sctp_chunk *chunk)
1186{
1187 __u16 ssn;
1188 __u16 sid;
1189
1190 if (chunk->has_ssn)
1191 return;
1192
1193 /* This is the last possible instant to assign a SSN. */
1194 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
1195 ssn = 0;
1196 } else {
1197 sid = htons(chunk->subh.data_hdr->stream);
1198 if (chunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG)
1199 ssn = sctp_ssn_next(&chunk->asoc->ssnmap->out, sid);
1200 else
1201 ssn = sctp_ssn_peek(&chunk->asoc->ssnmap->out, sid);
1202 ssn = htons(ssn);
1203 }
1204
1205 chunk->subh.data_hdr->ssn = ssn;
1206 chunk->has_ssn = 1;
1207}
1208
1209/* Helper function to assign a TSN if needed. This assumes that both
1210 * the data_hdr and association have already been assigned.
1211 */
1212void sctp_chunk_assign_tsn(struct sctp_chunk *chunk)
1213{
1214 if (!chunk->has_tsn) {
1215 /* This is the last possible instant to
1216 * assign a TSN.
1217 */
1218 chunk->subh.data_hdr->tsn =
1219 htonl(sctp_association_get_next_tsn(chunk->asoc));
1220 chunk->has_tsn = 1;
1221 }
1222}
1223
1224/* Create a CLOSED association to use with an incoming packet. */
1225struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep,
1226 struct sctp_chunk *chunk, int gfp)
1227{
1228 struct sctp_association *asoc;
1229 struct sk_buff *skb;
1230 sctp_scope_t scope;
1231 struct sctp_af *af;
1232
1233 /* Create the bare association. */
1234 scope = sctp_scope(sctp_source(chunk));
1235 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp);
1236 if (!asoc)
1237 goto nodata;
1238 asoc->temp = 1;
1239 skb = chunk->skb;
1240 /* Create an entry for the source address of the packet. */
1241 af = sctp_get_af_specific(ipver2af(skb->nh.iph->version));
1242 if (unlikely(!af))
1243 goto fail;
1244 af->from_skb(&asoc->c.peer_addr, skb, 1);
1245nodata:
1246 return asoc;
1247
1248fail:
1249 sctp_association_free(asoc);
1250 return NULL;
1251}
1252
1253/* Build a cookie representing asoc.
1254 * This INCLUDES the param header needed to put the cookie in the INIT ACK.
1255 */
1256static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep,
1257 const struct sctp_association *asoc,
1258 const struct sctp_chunk *init_chunk,
1259 int *cookie_len,
1260 const __u8 *raw_addrs, int addrs_len)
1261{
1262 sctp_cookie_param_t *retval;
1263 struct sctp_signed_cookie *cookie;
1264 struct scatterlist sg;
1265 int headersize, bodysize;
1266 unsigned int keylen;
1267 char *key;
1268
1269 headersize = sizeof(sctp_paramhdr_t) + SCTP_SECRET_SIZE;
1270 bodysize = sizeof(struct sctp_cookie)
1271 + ntohs(init_chunk->chunk_hdr->length) + addrs_len;
1272
1273 /* Pad out the cookie to a multiple to make the signature
1274 * functions simpler to write.
1275 */
1276 if (bodysize % SCTP_COOKIE_MULTIPLE)
1277 bodysize += SCTP_COOKIE_MULTIPLE
1278 - (bodysize % SCTP_COOKIE_MULTIPLE);
1279 *cookie_len = headersize + bodysize;
1280
1281 retval = (sctp_cookie_param_t *)kmalloc(*cookie_len, GFP_ATOMIC);
1282
1283 if (!retval) {
1284 *cookie_len = 0;
1285 goto nodata;
1286 }
1287
1288 /* Clear this memory since we are sending this data structure
1289 * out on the network.
1290 */
1291 memset(retval, 0x00, *cookie_len);
1292 cookie = (struct sctp_signed_cookie *) retval->body;
1293
1294 /* Set up the parameter header. */
1295 retval->p.type = SCTP_PARAM_STATE_COOKIE;
1296 retval->p.length = htons(*cookie_len);
1297
1298 /* Copy the cookie part of the association itself. */
1299 cookie->c = asoc->c;
1300 /* Save the raw address list length in the cookie. */
1301 cookie->c.raw_addr_list_len = addrs_len;
1302
1303 /* Remember PR-SCTP capability. */
1304 cookie->c.prsctp_capable = asoc->peer.prsctp_capable;
1305
1306 /* Save adaption indication in the cookie. */
1307 cookie->c.adaption_ind = asoc->peer.adaption_ind;
1308
1309 /* Set an expiration time for the cookie. */
1310 do_gettimeofday(&cookie->c.expiration);
1311 TIMEVAL_ADD(asoc->cookie_life, cookie->c.expiration);
1312
1313 /* Copy the peer's init packet. */
1314 memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr,
1315 ntohs(init_chunk->chunk_hdr->length));
1316
1317 /* Copy the raw local address list of the association. */
1318 memcpy((__u8 *)&cookie->c.peer_init[0] +
1319 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len);
1320
1321 if (sctp_sk(ep->base.sk)->hmac) {
1322 /* Sign the message. */
1323 sg.page = virt_to_page(&cookie->c);
1324 sg.offset = (unsigned long)(&cookie->c) % PAGE_SIZE;
1325 sg.length = bodysize;
1326 keylen = SCTP_SECRET_SIZE;
1327 key = (char *)ep->secret_key[ep->current_key];
1328
1329 sctp_crypto_hmac(sctp_sk(ep->base.sk)->hmac, key, &keylen,
1330 &sg, 1, cookie->signature);
1331 }
1332
1333nodata:
1334 return retval;
1335}
1336
1337/* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */
1338struct sctp_association *sctp_unpack_cookie(
1339 const struct sctp_endpoint *ep,
1340 const struct sctp_association *asoc,
1341 struct sctp_chunk *chunk, int gfp,
1342 int *error, struct sctp_chunk **errp)
1343{
1344 struct sctp_association *retval = NULL;
1345 struct sctp_signed_cookie *cookie;
1346 struct sctp_cookie *bear_cookie;
1347 int headersize, bodysize, fixed_size;
1348 __u8 digest[SCTP_SIGNATURE_SIZE];
1349 struct scatterlist sg;
1350 unsigned int keylen, len;
1351 char *key;
1352 sctp_scope_t scope;
1353 struct sk_buff *skb = chunk->skb;
1354
1355 headersize = sizeof(sctp_chunkhdr_t) + SCTP_SECRET_SIZE;
1356 bodysize = ntohs(chunk->chunk_hdr->length) - headersize;
1357 fixed_size = headersize + sizeof(struct sctp_cookie);
1358
1359 /* Verify that the chunk looks like it even has a cookie.
1360 * There must be enough room for our cookie and our peer's
1361 * INIT chunk.
1362 */
1363 len = ntohs(chunk->chunk_hdr->length);
1364 if (len < fixed_size + sizeof(struct sctp_chunkhdr))
1365 goto malformed;
1366
1367 /* Verify that the cookie has been padded out. */
1368 if (bodysize % SCTP_COOKIE_MULTIPLE)
1369 goto malformed;
1370
1371 /* Process the cookie. */
1372 cookie = chunk->subh.cookie_hdr;
1373 bear_cookie = &cookie->c;
1374
1375 if (!sctp_sk(ep->base.sk)->hmac)
1376 goto no_hmac;
1377
1378 /* Check the signature. */
1379 keylen = SCTP_SECRET_SIZE;
1380 sg.page = virt_to_page(bear_cookie);
1381 sg.offset = (unsigned long)(bear_cookie) % PAGE_SIZE;
1382 sg.length = bodysize;
1383 key = (char *)ep->secret_key[ep->current_key];
1384
1385 memset(digest, 0x00, sizeof(digest));
1386 sctp_crypto_hmac(sctp_sk(ep->base.sk)->hmac, key, &keylen, &sg,
1387 1, digest);
1388
1389 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
1390 /* Try the previous key. */
1391 key = (char *)ep->secret_key[ep->last_key];
1392 memset(digest, 0x00, sizeof(digest));
1393 sctp_crypto_hmac(sctp_sk(ep->base.sk)->hmac, key, &keylen,
1394 &sg, 1, digest);
1395
1396 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
1397 /* Yikes! Still bad signature! */
1398 *error = -SCTP_IERROR_BAD_SIG;
1399 goto fail;
1400 }
1401 }
1402
1403no_hmac:
1404 /* IG Section 2.35.2:
1405 * 3) Compare the port numbers and the verification tag contained
1406 * within the COOKIE ECHO chunk to the actual port numbers and the
1407 * verification tag within the SCTP common header of the received
1408 * packet. If these values do not match the packet MUST be silently
1409 * discarded,
1410 */
1411 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) {
1412 *error = -SCTP_IERROR_BAD_TAG;
1413 goto fail;
1414 }
1415
1416 if (ntohs(chunk->sctp_hdr->source) != bear_cookie->peer_addr.v4.sin_port ||
1417 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) {
1418 *error = -SCTP_IERROR_BAD_PORTS;
1419 goto fail;
1420 }
1421
1422 /* Check to see if the cookie is stale. If there is already
1423 * an association, there is no need to check cookie's expiration
1424 * for init collision case of lost COOKIE ACK.
1425 */
1426 if (!asoc && tv_lt(bear_cookie->expiration, skb->stamp)) {
1427 __u16 len;
1428 /*
1429 * Section 3.3.10.3 Stale Cookie Error (3)
1430 *
1431 * Cause of error
1432 * ---------------
1433 * Stale Cookie Error: Indicates the receipt of a valid State
1434 * Cookie that has expired.
1435 */
1436 len = ntohs(chunk->chunk_hdr->length);
1437 *errp = sctp_make_op_error_space(asoc, chunk, len);
1438 if (*errp) {
1439 suseconds_t usecs = (skb->stamp.tv_sec -
1440 bear_cookie->expiration.tv_sec) * 1000000L +
1441 skb->stamp.tv_usec -
1442 bear_cookie->expiration.tv_usec;
1443
1444 usecs = htonl(usecs);
1445 sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE,
1446 &usecs, sizeof(usecs));
1447 *error = -SCTP_IERROR_STALE_COOKIE;
1448 } else
1449 *error = -SCTP_IERROR_NOMEM;
1450
1451 goto fail;
1452 }
1453
1454 /* Make a new base association. */
1455 scope = sctp_scope(sctp_source(chunk));
1456 retval = sctp_association_new(ep, ep->base.sk, scope, gfp);
1457 if (!retval) {
1458 *error = -SCTP_IERROR_NOMEM;
1459 goto fail;
1460 }
1461
1462 /* Set up our peer's port number. */
1463 retval->peer.port = ntohs(chunk->sctp_hdr->source);
1464
1465 /* Populate the association from the cookie. */
1466 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie));
1467
1468 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie,
1469 GFP_ATOMIC) < 0) {
1470 *error = -SCTP_IERROR_NOMEM;
1471 goto fail;
1472 }
1473
1474 /* Also, add the destination address. */
1475 if (list_empty(&retval->base.bind_addr.address_list)) {
1476 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest,
1477 GFP_ATOMIC);
1478 }
1479
1480 retval->next_tsn = retval->c.initial_tsn;
1481 retval->ctsn_ack_point = retval->next_tsn - 1;
1482 retval->addip_serial = retval->c.initial_tsn;
1483 retval->adv_peer_ack_point = retval->ctsn_ack_point;
1484 retval->peer.prsctp_capable = retval->c.prsctp_capable;
1485 retval->peer.adaption_ind = retval->c.adaption_ind;
1486
1487 /* The INIT stuff will be done by the side effects. */
1488 return retval;
1489
1490fail:
1491 if (retval)
1492 sctp_association_free(retval);
1493
1494 return NULL;
1495
1496malformed:
1497 /* Yikes! The packet is either corrupt or deliberately
1498 * malformed.
1499 */
1500 *error = -SCTP_IERROR_MALFORMED;
1501 goto fail;
1502}
1503
1504/********************************************************************
1505 * 3rd Level Abstractions
1506 ********************************************************************/
1507
1508struct __sctp_missing {
1509 __u32 num_missing;
1510 __u16 type;
1511} __attribute__((packed));
1512
1513/*
1514 * Report a missing mandatory parameter.
1515 */
1516static int sctp_process_missing_param(const struct sctp_association *asoc,
1517 sctp_param_t paramtype,
1518 struct sctp_chunk *chunk,
1519 struct sctp_chunk **errp)
1520{
1521 struct __sctp_missing report;
1522 __u16 len;
1523
1524 len = WORD_ROUND(sizeof(report));
1525
1526 /* Make an ERROR chunk, preparing enough room for
1527 * returning multiple unknown parameters.
1528 */
1529 if (!*errp)
1530 *errp = sctp_make_op_error_space(asoc, chunk, len);
1531
1532 if (*errp) {
1533 report.num_missing = htonl(1);
1534 report.type = paramtype;
1535 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM,
1536 &report, sizeof(report));
1537 }
1538
1539 /* Stop processing this chunk. */
1540 return 0;
1541}
1542
1543/* Report an Invalid Mandatory Parameter. */
1544static int sctp_process_inv_mandatory(const struct sctp_association *asoc,
1545 struct sctp_chunk *chunk,
1546 struct sctp_chunk **errp)
1547{
1548 /* Invalid Mandatory Parameter Error has no payload. */
1549
1550 if (!*errp)
1551 *errp = sctp_make_op_error_space(asoc, chunk, 0);
1552
1553 if (*errp)
1554 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, NULL, 0);
1555
1556 /* Stop processing this chunk. */
1557 return 0;
1558}
1559
1560static int sctp_process_inv_paramlength(const struct sctp_association *asoc,
1561 struct sctp_paramhdr *param,
1562 const struct sctp_chunk *chunk,
1563 struct sctp_chunk **errp)
1564{
1565 char error[] = "The following parameter had invalid length:";
1566 size_t payload_len = WORD_ROUND(sizeof(error)) +
1567 sizeof(sctp_paramhdr_t);
1568
1569
1570 /* Create an error chunk and fill it in with our payload. */
1571 if (!*errp)
1572 *errp = sctp_make_op_error_space(asoc, chunk, payload_len);
1573
1574 if (*errp) {
1575 sctp_init_cause(*errp, SCTP_ERROR_PROTO_VIOLATION, error,
1576 sizeof(error));
1577 sctp_addto_chunk(*errp, sizeof(sctp_paramhdr_t), param);
1578 }
1579
1580 return 0;
1581}
1582
1583
1584/* Do not attempt to handle the HOST_NAME parm. However, do
1585 * send back an indicator to the peer.
1586 */
1587static int sctp_process_hn_param(const struct sctp_association *asoc,
1588 union sctp_params param,
1589 struct sctp_chunk *chunk,
1590 struct sctp_chunk **errp)
1591{
1592 __u16 len = ntohs(param.p->length);
1593
1594 /* Make an ERROR chunk. */
1595 if (!*errp)
1596 *errp = sctp_make_op_error_space(asoc, chunk, len);
1597
1598 if (*errp)
1599 sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED,
1600 param.v, len);
1601
1602 /* Stop processing this chunk. */
1603 return 0;
1604}
1605
1606/* RFC 3.2.1 & the Implementers Guide 2.2.
1607 *
1608 * The Parameter Types are encoded such that the
1609 * highest-order two bits specify the action that must be
1610 * taken if the processing endpoint does not recognize the
1611 * Parameter Type.
1612 *
1613 * 00 - Stop processing this SCTP chunk and discard it,
1614 * do not process any further chunks within it.
1615 *
1616 * 01 - Stop processing this SCTP chunk and discard it,
1617 * do not process any further chunks within it, and report
1618 * the unrecognized parameter in an 'Unrecognized
1619 * Parameter Type' (in either an ERROR or in the INIT ACK).
1620 *
1621 * 10 - Skip this parameter and continue processing.
1622 *
1623 * 11 - Skip this parameter and continue processing but
1624 * report the unrecognized parameter in an
1625 * 'Unrecognized Parameter Type' (in either an ERROR or in
1626 * the INIT ACK).
1627 *
1628 * Return value:
1629 * 0 - discard the chunk
1630 * 1 - continue with the chunk
1631 */
1632static int sctp_process_unk_param(const struct sctp_association *asoc,
1633 union sctp_params param,
1634 struct sctp_chunk *chunk,
1635 struct sctp_chunk **errp)
1636{
1637 int retval = 1;
1638
1639 switch (param.p->type & SCTP_PARAM_ACTION_MASK) {
1640 case SCTP_PARAM_ACTION_DISCARD:
1641 retval = 0;
1642 break;
1643 case SCTP_PARAM_ACTION_DISCARD_ERR:
1644 retval = 0;
1645 /* Make an ERROR chunk, preparing enough room for
1646 * returning multiple unknown parameters.
1647 */
1648 if (NULL == *errp)
1649 *errp = sctp_make_op_error_space(asoc, chunk,
1650 ntohs(chunk->chunk_hdr->length));
1651
1652 if (*errp)
1653 sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM,
1654 param.v,
1655 WORD_ROUND(ntohs(param.p->length)));
1656
1657 break;
1658 case SCTP_PARAM_ACTION_SKIP:
1659 break;
1660 case SCTP_PARAM_ACTION_SKIP_ERR:
1661 /* Make an ERROR chunk, preparing enough room for
1662 * returning multiple unknown parameters.
1663 */
1664 if (NULL == *errp)
1665 *errp = sctp_make_op_error_space(asoc, chunk,
1666 ntohs(chunk->chunk_hdr->length));
1667
1668 if (*errp) {
1669 sctp_init_cause(*errp, SCTP_ERROR_UNKNOWN_PARAM,
1670 param.v,
1671 WORD_ROUND(ntohs(param.p->length)));
1672 } else {
1673 /* If there is no memory for generating the ERROR
1674 * report as specified, an ABORT will be triggered
1675 * to the peer and the association won't be
1676 * established.
1677 */
1678 retval = 0;
1679 }
1680
1681 break;
1682 default:
1683 break;
1684 }
1685
1686 return retval;
1687}
1688
1689/* Find unrecognized parameters in the chunk.
1690 * Return values:
1691 * 0 - discard the chunk
1692 * 1 - continue with the chunk
1693 */
1694static int sctp_verify_param(const struct sctp_association *asoc,
1695 union sctp_params param,
1696 sctp_cid_t cid,
1697 struct sctp_chunk *chunk,
1698 struct sctp_chunk **err_chunk)
1699{
1700 int retval = 1;
1701
1702 /* FIXME - This routine is not looking at each parameter per the
1703 * chunk type, i.e., unrecognized parameters should be further
1704 * identified based on the chunk id.
1705 */
1706
1707 switch (param.p->type) {
1708 case SCTP_PARAM_IPV4_ADDRESS:
1709 case SCTP_PARAM_IPV6_ADDRESS:
1710 case SCTP_PARAM_COOKIE_PRESERVATIVE:
1711 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
1712 case SCTP_PARAM_STATE_COOKIE:
1713 case SCTP_PARAM_HEARTBEAT_INFO:
1714 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
1715 case SCTP_PARAM_ECN_CAPABLE:
1716 case SCTP_PARAM_ADAPTION_LAYER_IND:
1717 break;
1718
1719 case SCTP_PARAM_HOST_NAME_ADDRESS:
1720 /* Tell the peer, we won't support this param. */
1721 return sctp_process_hn_param(asoc, param, chunk, err_chunk);
1722 case SCTP_PARAM_FWD_TSN_SUPPORT:
1723 if (sctp_prsctp_enable)
1724 break;
1725 /* Fall Through */
1726 default:
1727 SCTP_DEBUG_PRINTK("Unrecognized param: %d for chunk %d.\n",
1728 ntohs(param.p->type), cid);
1729 return sctp_process_unk_param(asoc, param, chunk, err_chunk);
1730
1731 break;
1732 }
1733 return retval;
1734}
1735
1736/* Verify the INIT packet before we process it. */
1737int sctp_verify_init(const struct sctp_association *asoc,
1738 sctp_cid_t cid,
1739 sctp_init_chunk_t *peer_init,
1740 struct sctp_chunk *chunk,
1741 struct sctp_chunk **errp)
1742{
1743 union sctp_params param;
1744 int has_cookie = 0;
1745
1746 /* Verify stream values are non-zero. */
1747 if ((0 == peer_init->init_hdr.num_outbound_streams) ||
1748 (0 == peer_init->init_hdr.num_inbound_streams)) {
1749
1750 sctp_process_inv_mandatory(asoc, chunk, errp);
1751 return 0;
1752 }
1753
1754 /* Check for missing mandatory parameters. */
1755 sctp_walk_params(param, peer_init, init_hdr.params) {
1756
1757 if (SCTP_PARAM_STATE_COOKIE == param.p->type)
1758 has_cookie = 1;
1759
1760 } /* for (loop through all parameters) */
1761
1762 /* There is a possibility that a parameter length was bad and
1763 * in that case we would have stoped walking the parameters.
1764 * The current param.p would point at the bad one.
1765 * Current consensus on the mailing list is to generate a PROTOCOL
1766 * VIOLATION error. We build the ERROR chunk here and let the normal
1767 * error handling code build and send the packet.
1768 */
1769 if (param.v < (void*)chunk->chunk_end - sizeof(sctp_paramhdr_t)) {
1770 sctp_process_inv_paramlength(asoc, param.p, chunk, errp);
1771 return 0;
1772 }
1773
1774 /* The only missing mandatory param possible today is
1775 * the state cookie for an INIT-ACK chunk.
1776 */
1777 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie) {
1778 sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE,
1779 chunk, errp);
1780 return 0;
1781 }
1782
1783 /* Find unrecognized parameters. */
1784
1785 sctp_walk_params(param, peer_init, init_hdr.params) {
1786
1787 if (!sctp_verify_param(asoc, param, cid, chunk, errp)) {
1788 if (SCTP_PARAM_HOST_NAME_ADDRESS == param.p->type)
1789 return 0;
1790 else
1791 return 1;
1792 }
1793
1794 } /* for (loop through all parameters) */
1795
1796 return 1;
1797}
1798
1799/* Unpack the parameters in an INIT packet into an association.
1800 * Returns 0 on failure, else success.
1801 * FIXME: This is an association method.
1802 */
1803int sctp_process_init(struct sctp_association *asoc, sctp_cid_t cid,
1804 const union sctp_addr *peer_addr,
1805 sctp_init_chunk_t *peer_init, int gfp)
1806{
1807 union sctp_params param;
1808 struct sctp_transport *transport;
1809 struct list_head *pos, *temp;
1810 char *cookie;
1811
1812 /* We must include the address that the INIT packet came from.
1813 * This is the only address that matters for an INIT packet.
1814 * When processing a COOKIE ECHO, we retrieve the from address
1815 * of the INIT from the cookie.
1816 */
1817
1818 /* This implementation defaults to making the first transport
1819 * added as the primary transport. The source address seems to
1820 * be a a better choice than any of the embedded addresses.
1821 */
1822 if (peer_addr)
1823 if(!sctp_assoc_add_peer(asoc, peer_addr, gfp))
1824 goto nomem;
1825
1826 /* Process the initialization parameters. */
1827
1828 sctp_walk_params(param, peer_init, init_hdr.params) {
1829
1830 if (!sctp_process_param(asoc, param, peer_addr, gfp))
1831 goto clean_up;
1832 }
1833
1834 /* The fixed INIT headers are always in network byte
1835 * order.
1836 */
1837 asoc->peer.i.init_tag =
1838 ntohl(peer_init->init_hdr.init_tag);
1839 asoc->peer.i.a_rwnd =
1840 ntohl(peer_init->init_hdr.a_rwnd);
1841 asoc->peer.i.num_outbound_streams =
1842 ntohs(peer_init->init_hdr.num_outbound_streams);
1843 asoc->peer.i.num_inbound_streams =
1844 ntohs(peer_init->init_hdr.num_inbound_streams);
1845 asoc->peer.i.initial_tsn =
1846 ntohl(peer_init->init_hdr.initial_tsn);
1847
1848 /* Apply the upper bounds for output streams based on peer's
1849 * number of inbound streams.
1850 */
1851 if (asoc->c.sinit_num_ostreams >
1852 ntohs(peer_init->init_hdr.num_inbound_streams)) {
1853 asoc->c.sinit_num_ostreams =
1854 ntohs(peer_init->init_hdr.num_inbound_streams);
1855 }
1856
1857 if (asoc->c.sinit_max_instreams >
1858 ntohs(peer_init->init_hdr.num_outbound_streams)) {
1859 asoc->c.sinit_max_instreams =
1860 ntohs(peer_init->init_hdr.num_outbound_streams);
1861 }
1862
1863 /* Copy Initiation tag from INIT to VT_peer in cookie. */
1864 asoc->c.peer_vtag = asoc->peer.i.init_tag;
1865
1866 /* Peer Rwnd : Current calculated value of the peer's rwnd. */
1867 asoc->peer.rwnd = asoc->peer.i.a_rwnd;
1868
1869 /* Copy cookie in case we need to resend COOKIE-ECHO. */
1870 cookie = asoc->peer.cookie;
1871 if (cookie) {
1872 asoc->peer.cookie = kmalloc(asoc->peer.cookie_len, gfp);
1873 if (!asoc->peer.cookie)
1874 goto clean_up;
1875 memcpy(asoc->peer.cookie, cookie, asoc->peer.cookie_len);
1876 }
1877
1878 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily
1879 * high (for example, implementations MAY use the size of the receiver
1880 * advertised window).
1881 */
1882 list_for_each(pos, &asoc->peer.transport_addr_list) {
1883 transport = list_entry(pos, struct sctp_transport, transports);
1884 transport->ssthresh = asoc->peer.i.a_rwnd;
1885 }
1886
1887 /* Set up the TSN tracking pieces. */
1888 sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_SIZE,
1889 asoc->peer.i.initial_tsn);
1890
1891 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
1892 *
1893 * The stream sequence number in all the streams shall start
1894 * from 0 when the association is established. Also, when the
1895 * stream sequence number reaches the value 65535 the next
1896 * stream sequence number shall be set to 0.
1897 */
1898
1899 /* Allocate storage for the negotiated streams if it is not a temporary * association.
1900 */
1901 if (!asoc->temp) {
1902 int assoc_id;
1903 int error;
1904
1905 asoc->ssnmap = sctp_ssnmap_new(asoc->c.sinit_max_instreams,
1906 asoc->c.sinit_num_ostreams, gfp);
1907 if (!asoc->ssnmap)
1908 goto clean_up;
1909
1910 retry:
1911 if (unlikely(!idr_pre_get(&sctp_assocs_id, gfp)))
1912 goto clean_up;
1913 spin_lock_bh(&sctp_assocs_id_lock);
1914 error = idr_get_new_above(&sctp_assocs_id, (void *)asoc, 1,
1915 &assoc_id);
1916 spin_unlock_bh(&sctp_assocs_id_lock);
1917 if (error == -EAGAIN)
1918 goto retry;
1919 else if (error)
1920 goto clean_up;
1921
1922 asoc->assoc_id = (sctp_assoc_t) assoc_id;
1923 }
1924
1925 /* ADDIP Section 4.1 ASCONF Chunk Procedures
1926 *
1927 * When an endpoint has an ASCONF signaled change to be sent to the
1928 * remote endpoint it should do the following:
1929 * ...
1930 * A2) A serial number should be assigned to the Chunk. The serial
1931 * number should be a monotonically increasing number. All serial
1932 * numbers are defined to be initialized at the start of the
1933 * association to the same value as the Initial TSN.
1934 */
1935 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1;
1936 return 1;
1937
1938clean_up:
1939 /* Release the transport structures. */
1940 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
1941 transport = list_entry(pos, struct sctp_transport, transports);
1942 list_del_init(pos);
1943 sctp_transport_free(transport);
1944 }
1945nomem:
1946 return 0;
1947}
1948
1949
1950/* Update asoc with the option described in param.
1951 *
1952 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT
1953 *
1954 * asoc is the association to update.
1955 * param is the variable length parameter to use for update.
1956 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO.
1957 * If the current packet is an INIT we want to minimize the amount of
1958 * work we do. In particular, we should not build transport
1959 * structures for the addresses.
1960 */
1961static int sctp_process_param(struct sctp_association *asoc,
1962 union sctp_params param,
1963 const union sctp_addr *peer_addr,
1964 int gfp)
1965{
1966 union sctp_addr addr;
1967 int i;
1968 __u16 sat;
1969 int retval = 1;
1970 sctp_scope_t scope;
1971 time_t stale;
1972 struct sctp_af *af;
1973
1974 /* We maintain all INIT parameters in network byte order all the
1975 * time. This allows us to not worry about whether the parameters
1976 * came from a fresh INIT, and INIT ACK, or were stored in a cookie.
1977 */
1978 switch (param.p->type) {
1979 case SCTP_PARAM_IPV6_ADDRESS:
1980 if (PF_INET6 != asoc->base.sk->sk_family)
1981 break;
1982 /* Fall through. */
1983 case SCTP_PARAM_IPV4_ADDRESS:
1984 af = sctp_get_af_specific(param_type2af(param.p->type));
1985 af->from_addr_param(&addr, param.addr, asoc->peer.port, 0);
1986 scope = sctp_scope(peer_addr);
1987 if (sctp_in_scope(&addr, scope))
1988 if (!sctp_assoc_add_peer(asoc, &addr, gfp))
1989 return 0;
1990 break;
1991
1992 case SCTP_PARAM_COOKIE_PRESERVATIVE:
1993 if (!sctp_cookie_preserve_enable)
1994 break;
1995
1996 stale = ntohl(param.life->lifespan_increment);
1997
1998 /* Suggested Cookie Life span increment's unit is msec,
1999 * (1/1000sec).
2000 */
2001 asoc->cookie_life.tv_sec += stale / 1000;
2002 asoc->cookie_life.tv_usec += (stale % 1000) * 1000;
2003 break;
2004
2005 case SCTP_PARAM_HOST_NAME_ADDRESS:
2006 SCTP_DEBUG_PRINTK("unimplemented SCTP_HOST_NAME_ADDRESS\n");
2007 break;
2008
2009 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
2010 /* Turn off the default values first so we'll know which
2011 * ones are really set by the peer.
2012 */
2013 asoc->peer.ipv4_address = 0;
2014 asoc->peer.ipv6_address = 0;
2015
2016 /* Cycle through address types; avoid divide by 0. */
2017 sat = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
2018 if (sat)
2019 sat /= sizeof(__u16);
2020
2021 for (i = 0; i < sat; ++i) {
2022 switch (param.sat->types[i]) {
2023 case SCTP_PARAM_IPV4_ADDRESS:
2024 asoc->peer.ipv4_address = 1;
2025 break;
2026
2027 case SCTP_PARAM_IPV6_ADDRESS:
2028 asoc->peer.ipv6_address = 1;
2029 break;
2030
2031 case SCTP_PARAM_HOST_NAME_ADDRESS:
2032 asoc->peer.hostname_address = 1;
2033 break;
2034
2035 default: /* Just ignore anything else. */
2036 break;
2037 };
2038 }
2039 break;
2040
2041 case SCTP_PARAM_STATE_COOKIE:
2042 asoc->peer.cookie_len =
2043 ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
2044 asoc->peer.cookie = param.cookie->body;
2045 break;
2046
2047 case SCTP_PARAM_HEARTBEAT_INFO:
2048 /* Would be odd to receive, but it causes no problems. */
2049 break;
2050
2051 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
2052 /* Rejected during verify stage. */
2053 break;
2054
2055 case SCTP_PARAM_ECN_CAPABLE:
2056 asoc->peer.ecn_capable = 1;
2057 break;
2058
2059 case SCTP_PARAM_ADAPTION_LAYER_IND:
2060 asoc->peer.adaption_ind = param.aind->adaption_ind;
2061 break;
2062
2063 case SCTP_PARAM_FWD_TSN_SUPPORT:
2064 if (sctp_prsctp_enable) {
2065 asoc->peer.prsctp_capable = 1;
2066 break;
2067 }
2068 /* Fall Through */
2069 default:
2070 /* Any unrecognized parameters should have been caught
2071 * and handled by sctp_verify_param() which should be
2072 * called prior to this routine. Simply log the error
2073 * here.
2074 */
2075 SCTP_DEBUG_PRINTK("Ignoring param: %d for association %p.\n",
2076 ntohs(param.p->type), asoc);
2077 break;
2078 };
2079
2080 return retval;
2081}
2082
2083/* Select a new verification tag. */
2084__u32 sctp_generate_tag(const struct sctp_endpoint *ep)
2085{
2086 /* I believe that this random number generator complies with RFC1750.
2087 * A tag of 0 is reserved for special cases (e.g. INIT).
2088 */
2089 __u32 x;
2090
2091 do {
2092 get_random_bytes(&x, sizeof(__u32));
2093 } while (x == 0);
2094
2095 return x;
2096}
2097
2098/* Select an initial TSN to send during startup. */
2099__u32 sctp_generate_tsn(const struct sctp_endpoint *ep)
2100{
2101 __u32 retval;
2102
2103 get_random_bytes(&retval, sizeof(__u32));
2104 return retval;
2105}
2106
2107/*
2108 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF)
2109 * 0 1 2 3
2110 * 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
2111 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2112 * | Type = 0xC1 | Chunk Flags | Chunk Length |
2113 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2114 * | Serial Number |
2115 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2116 * | Address Parameter |
2117 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2118 * | ASCONF Parameter #1 |
2119 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2120 * \ \
2121 * / .... /
2122 * \ \
2123 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2124 * | ASCONF Parameter #N |
2125 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2126 *
2127 * Address Parameter and other parameter will not be wrapped in this function
2128 */
2129static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc,
2130 union sctp_addr *addr,
2131 int vparam_len)
2132{
2133 sctp_addiphdr_t asconf;
2134 struct sctp_chunk *retval;
2135 int length = sizeof(asconf) + vparam_len;
2136 union sctp_addr_param addrparam;
2137 int addrlen;
2138 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
2139
2140 addrlen = af->to_addr_param(addr, &addrparam);
2141 if (!addrlen)
2142 return NULL;
2143 length += addrlen;
2144
2145 /* Create the chunk. */
2146 retval = sctp_make_chunk(asoc, SCTP_CID_ASCONF, 0, length);
2147 if (!retval)
2148 return NULL;
2149
2150 asconf.serial = htonl(asoc->addip_serial++);
2151
2152 retval->subh.addip_hdr =
2153 sctp_addto_chunk(retval, sizeof(asconf), &asconf);
2154 retval->param_hdr.v =
2155 sctp_addto_chunk(retval, addrlen, &addrparam);
2156
2157 return retval;
2158}
2159
2160/* ADDIP
2161 * 3.2.1 Add IP Address
2162 * 0 1 2 3
2163 * 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
2164 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2165 * | Type = 0xC001 | Length = Variable |
2166 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2167 * | ASCONF-Request Correlation ID |
2168 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2169 * | Address Parameter |
2170 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2171 *
2172 * 3.2.2 Delete IP Address
2173 * 0 1 2 3
2174 * 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
2175 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2176 * | Type = 0xC002 | Length = Variable |
2177 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2178 * | ASCONF-Request Correlation ID |
2179 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2180 * | Address Parameter |
2181 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2182 *
2183 */
2184struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc,
2185 union sctp_addr *laddr,
2186 struct sockaddr *addrs,
2187 int addrcnt,
2188 __u16 flags)
2189{
2190 sctp_addip_param_t param;
2191 struct sctp_chunk *retval;
2192 union sctp_addr_param addr_param;
2193 union sctp_addr *addr;
2194 void *addr_buf;
2195 struct sctp_af *af;
2196 int paramlen = sizeof(param);
2197 int addr_param_len = 0;
2198 int totallen = 0;
2199 int i;
2200
2201 /* Get total length of all the address parameters. */
2202 addr_buf = addrs;
2203 for (i = 0; i < addrcnt; i++) {
2204 addr = (union sctp_addr *)addr_buf;
2205 af = sctp_get_af_specific(addr->v4.sin_family);
2206 addr_param_len = af->to_addr_param(addr, &addr_param);
2207
2208 totallen += paramlen;
2209 totallen += addr_param_len;
2210
2211 addr_buf += af->sockaddr_len;
2212 }
2213
2214 /* Create an asconf chunk with the required length. */
2215 retval = sctp_make_asconf(asoc, laddr, totallen);
2216 if (!retval)
2217 return NULL;
2218
2219 /* Add the address parameters to the asconf chunk. */
2220 addr_buf = addrs;
2221 for (i = 0; i < addrcnt; i++) {
2222 addr = (union sctp_addr *)addr_buf;
2223 af = sctp_get_af_specific(addr->v4.sin_family);
2224 addr_param_len = af->to_addr_param(addr, &addr_param);
2225 param.param_hdr.type = flags;
2226 param.param_hdr.length = htons(paramlen + addr_param_len);
2227 param.crr_id = i;
2228
2229 sctp_addto_chunk(retval, paramlen, &param);
2230 sctp_addto_chunk(retval, addr_param_len, &addr_param);
2231
2232 addr_buf += af->sockaddr_len;
2233 }
2234 return retval;
2235}
2236
2237/* ADDIP
2238 * 3.2.4 Set Primary IP Address
2239 * 0 1 2 3
2240 * 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
2241 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2242 * | Type =0xC004 | Length = Variable |
2243 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2244 * | ASCONF-Request Correlation ID |
2245 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2246 * | Address Parameter |
2247 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2248 *
2249 * Create an ASCONF chunk with Set Primary IP address parameter.
2250 */
2251struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
2252 union sctp_addr *addr)
2253{
2254 sctp_addip_param_t param;
2255 struct sctp_chunk *retval;
2256 int len = sizeof(param);
2257 union sctp_addr_param addrparam;
2258 int addrlen;
2259 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
2260
2261 addrlen = af->to_addr_param(addr, &addrparam);
2262 if (!addrlen)
2263 return NULL;
2264 len += addrlen;
2265
2266 /* Create the chunk and make asconf header. */
2267 retval = sctp_make_asconf(asoc, addr, len);
2268 if (!retval)
2269 return NULL;
2270
2271 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY;
2272 param.param_hdr.length = htons(len);
2273 param.crr_id = 0;
2274
2275 sctp_addto_chunk(retval, sizeof(param), &param);
2276 sctp_addto_chunk(retval, addrlen, &addrparam);
2277
2278 return retval;
2279}
2280
2281/* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK)
2282 * 0 1 2 3
2283 * 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
2284 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2285 * | Type = 0x80 | Chunk Flags | Chunk Length |
2286 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2287 * | Serial Number |
2288 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2289 * | ASCONF Parameter Response#1 |
2290 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2291 * \ \
2292 * / .... /
2293 * \ \
2294 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2295 * | ASCONF Parameter Response#N |
2296 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2297 *
2298 * Create an ASCONF_ACK chunk with enough space for the parameter responses.
2299 */
2300static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc,
2301 __u32 serial, int vparam_len)
2302{
2303 sctp_addiphdr_t asconf;
2304 struct sctp_chunk *retval;
2305 int length = sizeof(asconf) + vparam_len;
2306
2307 /* Create the chunk. */
2308 retval = sctp_make_chunk(asoc, SCTP_CID_ASCONF_ACK, 0, length);
2309 if (!retval)
2310 return NULL;
2311
2312 asconf.serial = htonl(serial);
2313
2314 retval->subh.addip_hdr =
2315 sctp_addto_chunk(retval, sizeof(asconf), &asconf);
2316
2317 return retval;
2318}
2319
2320/* Add response parameters to an ASCONF_ACK chunk. */
2321static void sctp_add_asconf_response(struct sctp_chunk *chunk, __u32 crr_id,
2322 __u16 err_code, sctp_addip_param_t *asconf_param)
2323{
2324 sctp_addip_param_t ack_param;
2325 sctp_errhdr_t err_param;
2326 int asconf_param_len = 0;
2327 int err_param_len = 0;
2328 __u16 response_type;
2329
2330 if (SCTP_ERROR_NO_ERROR == err_code) {
2331 response_type = SCTP_PARAM_SUCCESS_REPORT;
2332 } else {
2333 response_type = SCTP_PARAM_ERR_CAUSE;
2334 err_param_len = sizeof(err_param);
2335 if (asconf_param)
2336 asconf_param_len =
2337 ntohs(asconf_param->param_hdr.length);
2338 }
2339
2340 /* Add Success Indication or Error Cause Indication parameter. */
2341 ack_param.param_hdr.type = response_type;
2342 ack_param.param_hdr.length = htons(sizeof(ack_param) +
2343 err_param_len +
2344 asconf_param_len);
2345 ack_param.crr_id = crr_id;
2346 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param);
2347
2348 if (SCTP_ERROR_NO_ERROR == err_code)
2349 return;
2350
2351 /* Add Error Cause parameter. */
2352 err_param.cause = err_code;
2353 err_param.length = htons(err_param_len + asconf_param_len);
2354 sctp_addto_chunk(chunk, err_param_len, &err_param);
2355
2356 /* Add the failed TLV copied from ASCONF chunk. */
2357 if (asconf_param)
2358 sctp_addto_chunk(chunk, asconf_param_len, asconf_param);
2359}
2360
2361/* Process a asconf parameter. */
2362static __u16 sctp_process_asconf_param(struct sctp_association *asoc,
2363 struct sctp_chunk *asconf,
2364 sctp_addip_param_t *asconf_param)
2365{
2366 struct sctp_transport *peer;
2367 struct sctp_af *af;
2368 union sctp_addr addr;
2369 struct list_head *pos;
2370 union sctp_addr_param *addr_param;
2371
2372 addr_param = (union sctp_addr_param *)
2373 ((void *)asconf_param + sizeof(sctp_addip_param_t));
2374
2375 af = sctp_get_af_specific(param_type2af(addr_param->v4.param_hdr.type));
2376 if (unlikely(!af))
2377 return SCTP_ERROR_INV_PARAM;
2378
2379 af->from_addr_param(&addr, addr_param, asoc->peer.port, 0);
2380 switch (asconf_param->param_hdr.type) {
2381 case SCTP_PARAM_ADD_IP:
2382 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address
2383 * request and does not have the local resources to add this
2384 * new address to the association, it MUST return an Error
2385 * Cause TLV set to the new error code 'Operation Refused
2386 * Due to Resource Shortage'.
2387 */
2388
2389 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC);
2390 if (!peer)
2391 return SCTP_ERROR_RSRC_LOW;
2392
2393 /* Start the heartbeat timer. */
2394 if (!mod_timer(&peer->hb_timer, sctp_transport_timeout(peer)))
2395 sctp_transport_hold(peer);
2396 break;
2397 case SCTP_PARAM_DEL_IP:
2398 /* ADDIP 4.3 D7) If a request is received to delete the
2399 * last remaining IP address of a peer endpoint, the receiver
2400 * MUST send an Error Cause TLV with the error cause set to the
2401 * new error code 'Request to Delete Last Remaining IP Address'.
2402 */
2403 pos = asoc->peer.transport_addr_list.next;
2404 if (pos->next == &asoc->peer.transport_addr_list)
2405 return SCTP_ERROR_DEL_LAST_IP;
2406
2407 /* ADDIP 4.3 D8) If a request is received to delete an IP
2408 * address which is also the source address of the IP packet
2409 * which contained the ASCONF chunk, the receiver MUST reject
2410 * this request. To reject the request the receiver MUST send
2411 * an Error Cause TLV set to the new error code 'Request to
2412 * Delete Source IP Address'
2413 */
2414 if (sctp_cmp_addr_exact(sctp_source(asconf), &addr))
2415 return SCTP_ERROR_DEL_SRC_IP;
2416
2417 sctp_assoc_del_peer(asoc, &addr);
2418 break;
2419 case SCTP_PARAM_SET_PRIMARY:
2420 peer = sctp_assoc_lookup_paddr(asoc, &addr);
2421 if (!peer)
2422 return SCTP_ERROR_INV_PARAM;
2423
2424 sctp_assoc_set_primary(asoc, peer);
2425 break;
2426 default:
2427 return SCTP_ERROR_INV_PARAM;
2428 break;
2429 }
2430
2431 return SCTP_ERROR_NO_ERROR;
2432}
2433
2434/* Process an incoming ASCONF chunk with the next expected serial no. and
2435 * return an ASCONF_ACK chunk to be sent in response.
2436 */
2437struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
2438 struct sctp_chunk *asconf)
2439{
2440 sctp_addiphdr_t *hdr;
2441 union sctp_addr_param *addr_param;
2442 sctp_addip_param_t *asconf_param;
2443 struct sctp_chunk *asconf_ack;
2444
2445 __u16 err_code;
2446 int length = 0;
2447 int chunk_len = asconf->skb->len;
2448 __u32 serial;
2449 int all_param_pass = 1;
2450
2451 hdr = (sctp_addiphdr_t *)asconf->skb->data;
2452 serial = ntohl(hdr->serial);
2453
2454 /* Skip the addiphdr and store a pointer to address parameter. */
2455 length = sizeof(sctp_addiphdr_t);
2456 addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
2457 chunk_len -= length;
2458
2459 /* Skip the address parameter and store a pointer to the first
2460 * asconf paramter.
2461 */
2462 length = ntohs(addr_param->v4.param_hdr.length);
2463 asconf_param = (sctp_addip_param_t *)((void *)addr_param + length);
2464 chunk_len -= length;
2465
2466 /* create an ASCONF_ACK chunk.
2467 * Based on the definitions of parameters, we know that the size of
2468 * ASCONF_ACK parameters are less than or equal to the twice of ASCONF
2469 * paramters.
2470 */
2471 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 2);
2472 if (!asconf_ack)
2473 goto done;
2474
2475 /* Process the TLVs contained within the ASCONF chunk. */
2476 while (chunk_len > 0) {
2477 err_code = sctp_process_asconf_param(asoc, asconf,
2478 asconf_param);
2479 /* ADDIP 4.1 A7)
2480 * If an error response is received for a TLV parameter,
2481 * all TLVs with no response before the failed TLV are
2482 * considered successful if not reported. All TLVs after
2483 * the failed response are considered unsuccessful unless
2484 * a specific success indication is present for the parameter.
2485 */
2486 if (SCTP_ERROR_NO_ERROR != err_code)
2487 all_param_pass = 0;
2488
2489 if (!all_param_pass)
2490 sctp_add_asconf_response(asconf_ack,
2491 asconf_param->crr_id, err_code,
2492 asconf_param);
2493
2494 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add
2495 * an IP address sends an 'Out of Resource' in its response, it
2496 * MUST also fail any subsequent add or delete requests bundled
2497 * in the ASCONF.
2498 */
2499 if (SCTP_ERROR_RSRC_LOW == err_code)
2500 goto done;
2501
2502 /* Move to the next ASCONF param. */
2503 length = ntohs(asconf_param->param_hdr.length);
2504 asconf_param = (sctp_addip_param_t *)((void *)asconf_param +
2505 length);
2506 chunk_len -= length;
2507 }
2508
2509done:
2510 asoc->peer.addip_serial++;
2511
2512 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc
2513 * after freeing the reference to old asconf ack if any.
2514 */
2515 if (asconf_ack) {
2516 if (asoc->addip_last_asconf_ack)
2517 sctp_chunk_free(asoc->addip_last_asconf_ack);
2518
2519 sctp_chunk_hold(asconf_ack);
2520 asoc->addip_last_asconf_ack = asconf_ack;
2521 }
2522
2523 return asconf_ack;
2524}
2525
2526/* Process a asconf parameter that is successfully acked. */
2527static int sctp_asconf_param_success(struct sctp_association *asoc,
2528 sctp_addip_param_t *asconf_param)
2529{
2530 struct sctp_af *af;
2531 union sctp_addr addr;
2532 struct sctp_bind_addr *bp = &asoc->base.bind_addr;
2533 union sctp_addr_param *addr_param;
2534 struct list_head *pos;
2535 struct sctp_transport *transport;
2536 int retval = 0;
2537
2538 addr_param = (union sctp_addr_param *)
2539 ((void *)asconf_param + sizeof(sctp_addip_param_t));
2540
2541 /* We have checked the packet before, so we do not check again. */
2542 af = sctp_get_af_specific(param_type2af(addr_param->v4.param_hdr.type));
2543 af->from_addr_param(&addr, addr_param, bp->port, 0);
2544
2545 switch (asconf_param->param_hdr.type) {
2546 case SCTP_PARAM_ADD_IP:
2547 sctp_local_bh_disable();
2548 sctp_write_lock(&asoc->base.addr_lock);
2549 retval = sctp_add_bind_addr(bp, &addr, GFP_ATOMIC);
2550 sctp_write_unlock(&asoc->base.addr_lock);
2551 sctp_local_bh_enable();
2552 break;
2553 case SCTP_PARAM_DEL_IP:
2554 sctp_local_bh_disable();
2555 sctp_write_lock(&asoc->base.addr_lock);
2556 retval = sctp_del_bind_addr(bp, &addr);
2557 sctp_write_unlock(&asoc->base.addr_lock);
2558 sctp_local_bh_enable();
2559 list_for_each(pos, &asoc->peer.transport_addr_list) {
2560 transport = list_entry(pos, struct sctp_transport,
2561 transports);
2562 sctp_transport_route(transport, NULL,
2563 sctp_sk(asoc->base.sk));
2564 }
2565 break;
2566 default:
2567 break;
2568 }
2569
2570 return retval;
2571}
2572
2573/* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk
2574 * for the given asconf parameter. If there is no response for this parameter,
2575 * return the error code based on the third argument 'no_err'.
2576 * ADDIP 4.1
2577 * A7) If an error response is received for a TLV parameter, all TLVs with no
2578 * response before the failed TLV are considered successful if not reported.
2579 * All TLVs after the failed response are considered unsuccessful unless a
2580 * specific success indication is present for the parameter.
2581 */
2582static __u16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack,
2583 sctp_addip_param_t *asconf_param,
2584 int no_err)
2585{
2586 sctp_addip_param_t *asconf_ack_param;
2587 sctp_errhdr_t *err_param;
2588 int length;
2589 int asconf_ack_len = asconf_ack->skb->len;
2590 __u16 err_code;
2591
2592 if (no_err)
2593 err_code = SCTP_ERROR_NO_ERROR;
2594 else
2595 err_code = SCTP_ERROR_REQ_REFUSED;
2596
2597 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to
2598 * the first asconf_ack parameter.
2599 */
2600 length = sizeof(sctp_addiphdr_t);
2601 asconf_ack_param = (sctp_addip_param_t *)(asconf_ack->skb->data +
2602 length);
2603 asconf_ack_len -= length;
2604
2605 while (asconf_ack_len > 0) {
2606 if (asconf_ack_param->crr_id == asconf_param->crr_id) {
2607 switch(asconf_ack_param->param_hdr.type) {
2608 case SCTP_PARAM_SUCCESS_REPORT:
2609 return SCTP_ERROR_NO_ERROR;
2610 case SCTP_PARAM_ERR_CAUSE:
2611 length = sizeof(sctp_addip_param_t);
2612 err_param = (sctp_errhdr_t *)
2613 ((void *)asconf_ack_param + length);
2614 asconf_ack_len -= length;
2615 if (asconf_ack_len > 0)
2616 return err_param->cause;
2617 else
2618 return SCTP_ERROR_INV_PARAM;
2619 break;
2620 default:
2621 return SCTP_ERROR_INV_PARAM;
2622 }
2623 }
2624
2625 length = ntohs(asconf_ack_param->param_hdr.length);
2626 asconf_ack_param = (sctp_addip_param_t *)
2627 ((void *)asconf_ack_param + length);
2628 asconf_ack_len -= length;
2629 }
2630
2631 return err_code;
2632}
2633
2634/* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */
2635int sctp_process_asconf_ack(struct sctp_association *asoc,
2636 struct sctp_chunk *asconf_ack)
2637{
2638 struct sctp_chunk *asconf = asoc->addip_last_asconf;
2639 union sctp_addr_param *addr_param;
2640 sctp_addip_param_t *asconf_param;
2641 int length = 0;
2642 int asconf_len = asconf->skb->len;
2643 int all_param_pass = 0;
2644 int no_err = 1;
2645 int retval = 0;
2646 __u16 err_code = SCTP_ERROR_NO_ERROR;
2647
2648 /* Skip the chunkhdr and addiphdr from the last asconf sent and store
2649 * a pointer to address parameter.
2650 */
2651 length = sizeof(sctp_addip_chunk_t);
2652 addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
2653 asconf_len -= length;
2654
2655 /* Skip the address parameter in the last asconf sent and store a
2656 * pointer to the first asconf paramter.
2657 */
2658 length = ntohs(addr_param->v4.param_hdr.length);
2659 asconf_param = (sctp_addip_param_t *)((void *)addr_param + length);
2660 asconf_len -= length;
2661
2662 /* ADDIP 4.1
2663 * A8) If there is no response(s) to specific TLV parameter(s), and no
2664 * failures are indicated, then all request(s) are considered
2665 * successful.
2666 */
2667 if (asconf_ack->skb->len == sizeof(sctp_addiphdr_t))
2668 all_param_pass = 1;
2669
2670 /* Process the TLVs contained in the last sent ASCONF chunk. */
2671 while (asconf_len > 0) {
2672 if (all_param_pass)
2673 err_code = SCTP_ERROR_NO_ERROR;
2674 else {
2675 err_code = sctp_get_asconf_response(asconf_ack,
2676 asconf_param,
2677 no_err);
2678 if (no_err && (SCTP_ERROR_NO_ERROR != err_code))
2679 no_err = 0;
2680 }
2681
2682 switch (err_code) {
2683 case SCTP_ERROR_NO_ERROR:
2684 retval = sctp_asconf_param_success(asoc, asconf_param);
2685 break;
2686
2687 case SCTP_ERROR_RSRC_LOW:
2688 retval = 1;
2689 break;
2690
2691 case SCTP_ERROR_INV_PARAM:
2692 /* Disable sending this type of asconf parameter in
2693 * future.
2694 */
2695 asoc->peer.addip_disabled_mask |=
2696 asconf_param->param_hdr.type;
2697 break;
2698
2699 case SCTP_ERROR_REQ_REFUSED:
2700 case SCTP_ERROR_DEL_LAST_IP:
2701 case SCTP_ERROR_DEL_SRC_IP:
2702 default:
2703 break;
2704 }
2705
2706 /* Skip the processed asconf parameter and move to the next
2707 * one.
2708 */
2709 length = ntohs(asconf_param->param_hdr.length);
2710 asconf_param = (sctp_addip_param_t *)((void *)asconf_param +
2711 length);
2712 asconf_len -= length;
2713 }
2714
2715 /* Free the cached last sent asconf chunk. */
2716 sctp_chunk_free(asconf);
2717 asoc->addip_last_asconf = NULL;
2718
2719 /* Send the next asconf chunk from the addip chunk queue. */
2720 asconf = (struct sctp_chunk *)__skb_dequeue(&asoc->addip_chunks);
2721 if (asconf) {
2722 /* Hold the chunk until an ASCONF_ACK is received. */
2723 sctp_chunk_hold(asconf);
2724 if (sctp_primitive_ASCONF(asoc, asconf))
2725 sctp_chunk_free(asconf);
2726 else
2727 asoc->addip_last_asconf = asconf;
2728 }
2729
2730 return retval;
2731}
2732
2733/* Make a FWD TSN chunk. */
2734struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
2735 __u32 new_cum_tsn, size_t nstreams,
2736 struct sctp_fwdtsn_skip *skiplist)
2737{
2738 struct sctp_chunk *retval = NULL;
2739 struct sctp_fwdtsn_chunk *ftsn_chunk;
2740 struct sctp_fwdtsn_hdr ftsn_hdr;
2741 struct sctp_fwdtsn_skip skip;
2742 size_t hint;
2743 int i;
2744
2745 hint = (nstreams + 1) * sizeof(__u32);
2746
2747 /* Maybe set the T-bit if we have no association. */
2748 retval = sctp_make_chunk(asoc, SCTP_CID_FWD_TSN, 0, hint);
2749
2750 if (!retval)
2751 return NULL;
2752
2753 ftsn_chunk = (struct sctp_fwdtsn_chunk *)retval->subh.fwdtsn_hdr;
2754
2755 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn);
2756 retval->subh.fwdtsn_hdr =
2757 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr);
2758
2759 for (i = 0; i < nstreams; i++) {
2760 skip.stream = skiplist[i].stream;
2761 skip.ssn = skiplist[i].ssn;
2762 sctp_addto_chunk(retval, sizeof(skip), &skip);
2763 }
2764
2765 return retval;
2766}
Linux 6.x block layer and io_uring tree(s)