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.
7 * This file is part of the SCTP kernel implementation
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.
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)
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.
25 * You should have received a copy of the GNU General Public License
26 * along with GNU CC; see the file COPYING. If not, see
27 * <http://www.gnu.org/licenses/>.
29 * Please send any bug reports or fixes you make to the
31 * lksctp developers <linux-sctp@vger.kernel.org>
33 * Written or modified by:
34 * La Monte H.P. Yarroll <piggy@acm.org>
35 * Karl Knutson <karl@athena.chicago.il.us>
36 * C. Robin <chris@hundredacre.ac.uk>
37 * Jon Grimm <jgrimm@us.ibm.com>
38 * Xingang Guo <xingang.guo@intel.com>
39 * Dajiang Zhang <dajiang.zhang@nokia.com>
40 * Sridhar Samudrala <sri@us.ibm.com>
41 * Daisy Chang <daisyc@us.ibm.com>
42 * Ardelle Fan <ardelle.fan@intel.com>
43 * Kevin Gao <kevin.gao@intel.com>
46 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
48 #include <crypto/hash.h>
49 #include <linux/types.h>
50 #include <linux/kernel.h>
52 #include <linux/ipv6.h>
53 #include <linux/net.h>
54 #include <linux/inet.h>
55 #include <linux/scatterlist.h>
56 #include <linux/slab.h>
59 #include <linux/skbuff.h>
60 #include <linux/random.h> /* for get_random_bytes */
61 #include <net/sctp/sctp.h>
62 #include <net/sctp/sm.h>
64 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc,
65 __u8 type, __u8 flags, int paylen);
66 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc,
67 __u8 flags, int paylen);
68 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc,
69 __u8 type, __u8 flags, int paylen);
70 static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep,
71 const struct sctp_association *asoc,
72 const struct sctp_chunk *init_chunk,
74 const __u8 *raw_addrs, int addrs_len);
75 static int sctp_process_param(struct sctp_association *asoc,
76 union sctp_params param,
77 const union sctp_addr *peer_addr,
79 static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
81 static void *sctp_addto_chunk_fixed(struct sctp_chunk *, int len,
84 /* Control chunk destructor */
85 static void sctp_control_release_owner(struct sk_buff *skb)
87 /*TODO: do memory release */
90 static void sctp_control_set_owner_w(struct sctp_chunk *chunk)
92 struct sctp_association *asoc = chunk->asoc;
93 struct sk_buff *skb = chunk->skb;
95 /* TODO: properly account for control chunks.
96 * To do it right we'll need:
97 * 1) endpoint if association isn't known.
98 * 2) proper memory accounting.
100 * For now don't do anything for now.
102 skb->sk = asoc ? asoc->base.sk : NULL;
103 skb->destructor = sctp_control_release_owner;
106 /* What was the inbound interface for this chunk? */
107 int sctp_chunk_iif(const struct sctp_chunk *chunk)
112 af = sctp_get_af_specific(ipver2af(ip_hdr(chunk->skb)->version));
114 iif = af->skb_iif(chunk->skb);
119 /* RFC 2960 3.3.2 Initiation (INIT) (1)
121 * Note 2: The ECN capable field is reserved for future use of
122 * Explicit Congestion Notification.
124 static const struct sctp_paramhdr ecap_param = {
125 SCTP_PARAM_ECN_CAPABLE,
126 cpu_to_be16(sizeof(struct sctp_paramhdr)),
128 static const struct sctp_paramhdr prsctp_param = {
129 SCTP_PARAM_FWD_TSN_SUPPORT,
130 cpu_to_be16(sizeof(struct sctp_paramhdr)),
133 /* A helper to initialize an op error inside a
134 * provided chunk, as most cause codes will be embedded inside an
137 void sctp_init_cause(struct sctp_chunk *chunk, __be16 cause_code,
143 /* Cause code constants are now defined in network order. */
144 err.cause = cause_code;
145 len = sizeof(sctp_errhdr_t) + paylen;
146 err.length = htons(len);
147 chunk->subh.err_hdr = sctp_addto_chunk(chunk, sizeof(sctp_errhdr_t), &err);
150 /* A helper to initialize an op error inside a
151 * provided chunk, as most cause codes will be embedded inside an
152 * abort chunk. Differs from sctp_init_cause in that it won't oops
153 * if there isn't enough space in the op error chunk
155 static int sctp_init_cause_fixed(struct sctp_chunk *chunk, __be16 cause_code,
161 /* Cause code constants are now defined in network order. */
162 err.cause = cause_code;
163 len = sizeof(sctp_errhdr_t) + paylen;
164 err.length = htons(len);
166 if (skb_tailroom(chunk->skb) < len)
168 chunk->subh.err_hdr = sctp_addto_chunk_fixed(chunk,
169 sizeof(sctp_errhdr_t),
173 /* 3.3.2 Initiation (INIT) (1)
175 * This chunk is used to initiate a SCTP association between two
176 * endpoints. The format of the INIT chunk is shown below:
179 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
180 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
181 * | Type = 1 | Chunk Flags | Chunk Length |
182 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
184 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
185 * | Advertised Receiver Window Credit (a_rwnd) |
186 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
187 * | Number of Outbound Streams | Number of Inbound Streams |
188 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
190 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
192 * / Optional/Variable-Length Parameters /
194 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
197 * The INIT chunk contains the following parameters. Unless otherwise
198 * noted, each parameter MUST only be included once in the INIT chunk.
200 * Fixed Parameters Status
201 * ----------------------------------------------
202 * Initiate Tag Mandatory
203 * Advertised Receiver Window Credit Mandatory
204 * Number of Outbound Streams Mandatory
205 * Number of Inbound Streams Mandatory
206 * Initial TSN Mandatory
208 * Variable Parameters Status Type Value
209 * -------------------------------------------------------------
210 * IPv4 Address (Note 1) Optional 5
211 * IPv6 Address (Note 1) Optional 6
212 * Cookie Preservative Optional 9
213 * Reserved for ECN Capable (Note 2) Optional 32768 (0x8000)
214 * Host Name Address (Note 3) Optional 11
215 * Supported Address Types (Note 4) Optional 12
217 struct sctp_chunk *sctp_make_init(const struct sctp_association *asoc,
218 const struct sctp_bind_addr *bp,
219 gfp_t gfp, int vparam_len)
221 struct net *net = sock_net(asoc->base.sk);
222 struct sctp_endpoint *ep = asoc->ep;
224 union sctp_params addrs;
226 struct sctp_chunk *retval = NULL;
227 int num_types, addrs_len = 0;
228 struct sctp_sock *sp;
229 sctp_supported_addrs_param_t sat;
231 sctp_adaptation_ind_param_t aiparam;
232 sctp_supported_ext_param_t ext_param;
235 sctp_paramhdr_t *auth_chunks = NULL,
238 /* RFC 2960 3.3.2 Initiation (INIT) (1)
240 * Note 1: The INIT chunks can contain multiple addresses that
241 * can be IPv4 and/or IPv6 in any combination.
245 /* Convert the provided bind address list to raw format. */
246 addrs = sctp_bind_addrs_to_raw(bp, &addrs_len, gfp);
248 init.init_tag = htonl(asoc->c.my_vtag);
249 init.a_rwnd = htonl(asoc->rwnd);
250 init.num_outbound_streams = htons(asoc->c.sinit_num_ostreams);
251 init.num_inbound_streams = htons(asoc->c.sinit_max_instreams);
252 init.initial_tsn = htonl(asoc->c.initial_tsn);
254 /* How many address types are needed? */
255 sp = sctp_sk(asoc->base.sk);
256 num_types = sp->pf->supported_addrs(sp, types);
258 chunksize = sizeof(init) + addrs_len;
259 chunksize += WORD_ROUND(SCTP_SAT_LEN(num_types));
260 chunksize += sizeof(ecap_param);
262 if (net->sctp.prsctp_enable)
263 chunksize += sizeof(prsctp_param);
265 /* ADDIP: Section 4.2.7:
266 * An implementation supporting this extension [ADDIP] MUST list
267 * the ASCONF,the ASCONF-ACK, and the AUTH chunks in its INIT and
268 * INIT-ACK parameters.
270 if (net->sctp.addip_enable) {
271 extensions[num_ext] = SCTP_CID_ASCONF;
272 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
276 if (sp->adaptation_ind)
277 chunksize += sizeof(aiparam);
279 chunksize += vparam_len;
281 /* Account for AUTH related parameters */
282 if (ep->auth_enable) {
283 /* Add random parameter length*/
284 chunksize += sizeof(asoc->c.auth_random);
286 /* Add HMACS parameter length if any were defined */
287 auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs;
288 if (auth_hmacs->length)
289 chunksize += WORD_ROUND(ntohs(auth_hmacs->length));
293 /* Add CHUNKS parameter length */
294 auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks;
295 if (auth_chunks->length)
296 chunksize += WORD_ROUND(ntohs(auth_chunks->length));
300 extensions[num_ext] = SCTP_CID_AUTH;
304 /* If we have any extensions to report, account for that */
306 chunksize += WORD_ROUND(sizeof(sctp_supported_ext_param_t) +
309 /* RFC 2960 3.3.2 Initiation (INIT) (1)
311 * Note 3: An INIT chunk MUST NOT contain more than one Host
312 * Name address parameter. Moreover, the sender of the INIT
313 * MUST NOT combine any other address types with the Host Name
314 * address in the INIT. The receiver of INIT MUST ignore any
315 * other address types if the Host Name address parameter is
316 * present in the received INIT chunk.
318 * PLEASE DO NOT FIXME [This version does not support Host Name.]
321 retval = sctp_make_control(asoc, SCTP_CID_INIT, 0, chunksize);
325 retval->subh.init_hdr =
326 sctp_addto_chunk(retval, sizeof(init), &init);
327 retval->param_hdr.v =
328 sctp_addto_chunk(retval, addrs_len, addrs.v);
330 /* RFC 2960 3.3.2 Initiation (INIT) (1)
332 * Note 4: This parameter, when present, specifies all the
333 * address types the sending endpoint can support. The absence
334 * of this parameter indicates that the sending endpoint can
335 * support any address type.
337 sat.param_hdr.type = SCTP_PARAM_SUPPORTED_ADDRESS_TYPES;
338 sat.param_hdr.length = htons(SCTP_SAT_LEN(num_types));
339 sctp_addto_chunk(retval, sizeof(sat), &sat);
340 sctp_addto_chunk(retval, num_types * sizeof(__u16), &types);
342 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
344 /* Add the supported extensions parameter. Be nice and add this
345 * fist before addiding the parameters for the extensions themselves
348 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
349 ext_param.param_hdr.length =
350 htons(sizeof(sctp_supported_ext_param_t) + num_ext);
351 sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t),
353 sctp_addto_param(retval, num_ext, extensions);
356 if (net->sctp.prsctp_enable)
357 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
359 if (sp->adaptation_ind) {
360 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
361 aiparam.param_hdr.length = htons(sizeof(aiparam));
362 aiparam.adaptation_ind = htonl(sp->adaptation_ind);
363 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
366 /* Add SCTP-AUTH chunks to the parameter list */
367 if (ep->auth_enable) {
368 sctp_addto_chunk(retval, sizeof(asoc->c.auth_random),
369 asoc->c.auth_random);
371 sctp_addto_chunk(retval, ntohs(auth_hmacs->length),
374 sctp_addto_chunk(retval, ntohs(auth_chunks->length),
382 struct sctp_chunk *sctp_make_init_ack(const struct sctp_association *asoc,
383 const struct sctp_chunk *chunk,
384 gfp_t gfp, int unkparam_len)
386 sctp_inithdr_t initack;
387 struct sctp_chunk *retval;
388 union sctp_params addrs;
389 struct sctp_sock *sp;
391 sctp_cookie_param_t *cookie;
394 sctp_adaptation_ind_param_t aiparam;
395 sctp_supported_ext_param_t ext_param;
398 sctp_paramhdr_t *auth_chunks = NULL,
404 /* Note: there may be no addresses to embed. */
405 addrs = sctp_bind_addrs_to_raw(&asoc->base.bind_addr, &addrs_len, gfp);
407 initack.init_tag = htonl(asoc->c.my_vtag);
408 initack.a_rwnd = htonl(asoc->rwnd);
409 initack.num_outbound_streams = htons(asoc->c.sinit_num_ostreams);
410 initack.num_inbound_streams = htons(asoc->c.sinit_max_instreams);
411 initack.initial_tsn = htonl(asoc->c.initial_tsn);
413 /* FIXME: We really ought to build the cookie right
414 * into the packet instead of allocating more fresh memory.
416 cookie = sctp_pack_cookie(asoc->ep, asoc, chunk, &cookie_len,
421 /* Calculate the total size of allocation, include the reserved
422 * space for reporting unknown parameters if it is specified.
424 sp = sctp_sk(asoc->base.sk);
425 chunksize = sizeof(initack) + addrs_len + cookie_len + unkparam_len;
427 /* Tell peer that we'll do ECN only if peer advertised such cap. */
428 if (asoc->peer.ecn_capable)
429 chunksize += sizeof(ecap_param);
431 if (asoc->peer.prsctp_capable)
432 chunksize += sizeof(prsctp_param);
434 if (asoc->peer.asconf_capable) {
435 extensions[num_ext] = SCTP_CID_ASCONF;
436 extensions[num_ext+1] = SCTP_CID_ASCONF_ACK;
440 if (sp->adaptation_ind)
441 chunksize += sizeof(aiparam);
443 if (asoc->peer.auth_capable) {
444 auth_random = (sctp_paramhdr_t *)asoc->c.auth_random;
445 chunksize += ntohs(auth_random->length);
447 auth_hmacs = (sctp_paramhdr_t *)asoc->c.auth_hmacs;
448 if (auth_hmacs->length)
449 chunksize += WORD_ROUND(ntohs(auth_hmacs->length));
453 auth_chunks = (sctp_paramhdr_t *)asoc->c.auth_chunks;
454 if (auth_chunks->length)
455 chunksize += WORD_ROUND(ntohs(auth_chunks->length));
459 extensions[num_ext] = SCTP_CID_AUTH;
464 chunksize += WORD_ROUND(sizeof(sctp_supported_ext_param_t) +
467 /* Now allocate and fill out the chunk. */
468 retval = sctp_make_control(asoc, SCTP_CID_INIT_ACK, 0, chunksize);
472 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
474 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
475 * HEARTBEAT ACK, * etc.) to the same destination transport
476 * address from which it received the DATA or control chunk
477 * to which it is replying.
479 * [INIT ACK back to where the INIT came from.]
481 retval->transport = chunk->transport;
483 retval->subh.init_hdr =
484 sctp_addto_chunk(retval, sizeof(initack), &initack);
485 retval->param_hdr.v = sctp_addto_chunk(retval, addrs_len, addrs.v);
486 sctp_addto_chunk(retval, cookie_len, cookie);
487 if (asoc->peer.ecn_capable)
488 sctp_addto_chunk(retval, sizeof(ecap_param), &ecap_param);
490 ext_param.param_hdr.type = SCTP_PARAM_SUPPORTED_EXT;
491 ext_param.param_hdr.length =
492 htons(sizeof(sctp_supported_ext_param_t) + num_ext);
493 sctp_addto_chunk(retval, sizeof(sctp_supported_ext_param_t),
495 sctp_addto_param(retval, num_ext, extensions);
497 if (asoc->peer.prsctp_capable)
498 sctp_addto_chunk(retval, sizeof(prsctp_param), &prsctp_param);
500 if (sp->adaptation_ind) {
501 aiparam.param_hdr.type = SCTP_PARAM_ADAPTATION_LAYER_IND;
502 aiparam.param_hdr.length = htons(sizeof(aiparam));
503 aiparam.adaptation_ind = htonl(sp->adaptation_ind);
504 sctp_addto_chunk(retval, sizeof(aiparam), &aiparam);
507 if (asoc->peer.auth_capable) {
508 sctp_addto_chunk(retval, ntohs(auth_random->length),
511 sctp_addto_chunk(retval, ntohs(auth_hmacs->length),
514 sctp_addto_chunk(retval, ntohs(auth_chunks->length),
518 /* We need to remove the const qualifier at this point. */
519 retval->asoc = (struct sctp_association *) asoc;
528 /* 3.3.11 Cookie Echo (COOKIE ECHO) (10):
530 * This chunk is used only during the initialization of an association.
531 * It is sent by the initiator of an association to its peer to complete
532 * the initialization process. This chunk MUST precede any DATA chunk
533 * sent within the association, but MAY be bundled with one or more DATA
534 * chunks in the same packet.
537 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
538 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
539 * | Type = 10 |Chunk Flags | Length |
540 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
543 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
547 * Set to zero on transmit and ignored on receipt.
549 * Length: 16 bits (unsigned integer)
551 * Set to the size of the chunk in bytes, including the 4 bytes of
552 * the chunk header and the size of the Cookie.
554 * Cookie: variable size
556 * This field must contain the exact cookie received in the
557 * State Cookie parameter from the previous INIT ACK.
559 * An implementation SHOULD make the cookie as small as possible
560 * to insure interoperability.
562 struct sctp_chunk *sctp_make_cookie_echo(const struct sctp_association *asoc,
563 const struct sctp_chunk *chunk)
565 struct sctp_chunk *retval;
569 cookie = asoc->peer.cookie;
570 cookie_len = asoc->peer.cookie_len;
572 /* Build a cookie echo chunk. */
573 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ECHO, 0, cookie_len);
576 retval->subh.cookie_hdr =
577 sctp_addto_chunk(retval, cookie_len, cookie);
579 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
581 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
582 * HEARTBEAT ACK, * etc.) to the same destination transport
583 * address from which it * received the DATA or control chunk
584 * to which it is replying.
586 * [COOKIE ECHO back to where the INIT ACK came from.]
589 retval->transport = chunk->transport;
595 /* 3.3.12 Cookie Acknowledgement (COOKIE ACK) (11):
597 * This chunk is used only during the initialization of an
598 * association. It is used to acknowledge the receipt of a COOKIE
599 * ECHO chunk. This chunk MUST precede any DATA or SACK chunk sent
600 * within the association, but MAY be bundled with one or more DATA
601 * chunks or SACK chunk in the same SCTP packet.
604 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
605 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
606 * | Type = 11 |Chunk Flags | Length = 4 |
607 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
609 * Chunk Flags: 8 bits
611 * Set to zero on transmit and ignored on receipt.
613 struct sctp_chunk *sctp_make_cookie_ack(const struct sctp_association *asoc,
614 const struct sctp_chunk *chunk)
616 struct sctp_chunk *retval;
618 retval = sctp_make_control(asoc, SCTP_CID_COOKIE_ACK, 0, 0);
620 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
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.
627 * [COOKIE ACK back to where the COOKIE ECHO came from.]
630 retval->transport = chunk->transport;
636 * Appendix A: Explicit Congestion Notification:
639 * RFC 2481 details a specific bit for a sender to send in the header of
640 * its next outbound TCP segment to indicate to its peer that it has
641 * reduced its congestion window. This is termed the CWR bit. For
642 * SCTP the same indication is made by including the CWR chunk.
643 * This chunk contains one data element, i.e. the TSN number that
644 * was sent in the ECNE chunk. This element represents the lowest
645 * TSN number in the datagram that was originally marked with the
649 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
650 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
651 * | Chunk Type=13 | Flags=00000000| Chunk Length = 8 |
652 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
653 * | Lowest TSN Number |
654 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
656 * Note: The CWR is considered a Control chunk.
658 struct sctp_chunk *sctp_make_cwr(const struct sctp_association *asoc,
659 const __u32 lowest_tsn,
660 const struct sctp_chunk *chunk)
662 struct sctp_chunk *retval;
665 cwr.lowest_tsn = htonl(lowest_tsn);
666 retval = sctp_make_control(asoc, SCTP_CID_ECN_CWR, 0,
667 sizeof(sctp_cwrhdr_t));
672 retval->subh.ecn_cwr_hdr =
673 sctp_addto_chunk(retval, sizeof(cwr), &cwr);
675 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
677 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
678 * HEARTBEAT ACK, * etc.) to the same destination transport
679 * address from which it * received the DATA or control chunk
680 * to which it is replying.
682 * [Report a reduced congestion window back to where the ECNE
686 retval->transport = chunk->transport;
692 /* Make an ECNE chunk. This is a congestion experienced report. */
693 struct sctp_chunk *sctp_make_ecne(const struct sctp_association *asoc,
694 const __u32 lowest_tsn)
696 struct sctp_chunk *retval;
699 ecne.lowest_tsn = htonl(lowest_tsn);
700 retval = sctp_make_control(asoc, SCTP_CID_ECN_ECNE, 0,
701 sizeof(sctp_ecnehdr_t));
704 retval->subh.ecne_hdr =
705 sctp_addto_chunk(retval, sizeof(ecne), &ecne);
711 /* Make a DATA chunk for the given association from the provided
712 * parameters. However, do not populate the data payload.
714 struct sctp_chunk *sctp_make_datafrag_empty(struct sctp_association *asoc,
715 const struct sctp_sndrcvinfo *sinfo,
716 int data_len, __u8 flags, __u16 ssn)
718 struct sctp_chunk *retval;
719 struct sctp_datahdr dp;
722 /* We assign the TSN as LATE as possible, not here when
723 * creating the chunk.
726 dp.stream = htons(sinfo->sinfo_stream);
727 dp.ppid = sinfo->sinfo_ppid;
729 /* Set the flags for an unordered send. */
730 if (sinfo->sinfo_flags & SCTP_UNORDERED) {
731 flags |= SCTP_DATA_UNORDERED;
736 chunk_len = sizeof(dp) + data_len;
737 retval = sctp_make_data(asoc, flags, chunk_len);
741 retval->subh.data_hdr = sctp_addto_chunk(retval, sizeof(dp), &dp);
742 memcpy(&retval->sinfo, sinfo, sizeof(struct sctp_sndrcvinfo));
748 /* Create a selective ackowledgement (SACK) for the given
749 * association. This reports on which TSN's we've seen to date,
750 * including duplicates and gaps.
752 struct sctp_chunk *sctp_make_sack(const struct sctp_association *asoc)
754 struct sctp_chunk *retval;
755 struct sctp_sackhdr sack;
758 __u16 num_gabs, num_dup_tsns;
759 struct sctp_association *aptr = (struct sctp_association *)asoc;
760 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
761 struct sctp_gap_ack_block gabs[SCTP_MAX_GABS];
762 struct sctp_transport *trans;
764 memset(gabs, 0, sizeof(gabs));
765 ctsn = sctp_tsnmap_get_ctsn(map);
767 pr_debug("%s: sackCTSNAck sent:0x%x\n", __func__, ctsn);
769 /* How much room is needed in the chunk? */
770 num_gabs = sctp_tsnmap_num_gabs(map, gabs);
771 num_dup_tsns = sctp_tsnmap_num_dups(map);
773 /* Initialize the SACK header. */
774 sack.cum_tsn_ack = htonl(ctsn);
775 sack.a_rwnd = htonl(asoc->a_rwnd);
776 sack.num_gap_ack_blocks = htons(num_gabs);
777 sack.num_dup_tsns = htons(num_dup_tsns);
780 + sizeof(struct sctp_gap_ack_block) * num_gabs
781 + sizeof(__u32) * num_dup_tsns;
783 /* Create the chunk. */
784 retval = sctp_make_control(asoc, SCTP_CID_SACK, 0, len);
788 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
790 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
791 * HEARTBEAT ACK, etc.) to the same destination transport
792 * address from which it received the DATA or control chunk to
793 * which it is replying. This rule should also be followed if
794 * the endpoint is bundling DATA chunks together with the
797 * However, when acknowledging multiple DATA chunks received
798 * in packets from different source addresses in a single
799 * SACK, the SACK chunk may be transmitted to one of the
800 * destination transport addresses from which the DATA or
801 * control chunks being acknowledged were received.
803 * [BUG: We do not implement the following paragraph.
804 * Perhaps we should remember the last transport we used for a
805 * SACK and avoid that (if possible) if we have seen any
806 * duplicates. --piggy]
808 * When a receiver of a duplicate DATA chunk sends a SACK to a
809 * multi- homed endpoint it MAY be beneficial to vary the
810 * destination address and not use the source address of the
811 * DATA chunk. The reason being that receiving a duplicate
812 * from a multi-homed endpoint might indicate that the return
813 * path (as specified in the source address of the DATA chunk)
814 * for the SACK is broken.
816 * [Send to the address from which we last received a DATA chunk.]
818 retval->transport = asoc->peer.last_data_from;
820 retval->subh.sack_hdr =
821 sctp_addto_chunk(retval, sizeof(sack), &sack);
823 /* Add the gap ack block information. */
825 sctp_addto_chunk(retval, sizeof(__u32) * num_gabs,
828 /* Add the duplicate TSN information. */
830 aptr->stats.idupchunks += num_dup_tsns;
831 sctp_addto_chunk(retval, sizeof(__u32) * num_dup_tsns,
832 sctp_tsnmap_get_dups(map));
834 /* Once we have a sack generated, check to see what our sack
835 * generation is, if its 0, reset the transports to 0, and reset
836 * the association generation to 1
838 * The idea is that zero is never used as a valid generation for the
839 * association so no transport will match after a wrap event like this,
840 * Until the next sack
842 if (++aptr->peer.sack_generation == 0) {
843 list_for_each_entry(trans, &asoc->peer.transport_addr_list,
845 trans->sack_generation = 0;
846 aptr->peer.sack_generation = 1;
852 /* Make a SHUTDOWN chunk. */
853 struct sctp_chunk *sctp_make_shutdown(const struct sctp_association *asoc,
854 const struct sctp_chunk *chunk)
856 struct sctp_chunk *retval;
857 sctp_shutdownhdr_t shut;
860 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
861 shut.cum_tsn_ack = htonl(ctsn);
863 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN, 0,
864 sizeof(sctp_shutdownhdr_t));
868 retval->subh.shutdown_hdr =
869 sctp_addto_chunk(retval, sizeof(shut), &shut);
872 retval->transport = chunk->transport;
877 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc,
878 const struct sctp_chunk *chunk)
880 struct sctp_chunk *retval;
882 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0);
884 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
886 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
887 * HEARTBEAT ACK, * etc.) to the same destination transport
888 * address from which it * received the DATA or control chunk
889 * to which it is replying.
891 * [ACK back to where the SHUTDOWN came from.]
894 retval->transport = chunk->transport;
899 struct sctp_chunk *sctp_make_shutdown_complete(
900 const struct sctp_association *asoc,
901 const struct sctp_chunk *chunk)
903 struct sctp_chunk *retval;
906 /* Set the T-bit if we have no association (vtag will be
909 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T;
911 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 0);
913 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
915 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
916 * HEARTBEAT ACK, * etc.) to the same destination transport
917 * address from which it * received the DATA or control chunk
918 * to which it is replying.
920 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK
924 retval->transport = chunk->transport;
929 /* Create an ABORT. Note that we set the T bit if we have no
930 * association, except when responding to an INIT (sctpimpguide 2.41).
932 struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc,
933 const struct sctp_chunk *chunk,
936 struct sctp_chunk *retval;
939 /* Set the T-bit if we have no association and 'chunk' is not
940 * an INIT (vtag will be reflected).
943 if (chunk && chunk->chunk_hdr &&
944 chunk->chunk_hdr->type == SCTP_CID_INIT)
947 flags = SCTP_CHUNK_FLAG_T;
950 retval = sctp_make_control(asoc, SCTP_CID_ABORT, flags, hint);
952 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
954 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
955 * HEARTBEAT ACK, * etc.) to the same destination transport
956 * address from which it * received the DATA or control chunk
957 * to which it is replying.
959 * [ABORT back to where the offender came from.]
962 retval->transport = chunk->transport;
967 /* Helper to create ABORT with a NO_USER_DATA error. */
968 struct sctp_chunk *sctp_make_abort_no_data(
969 const struct sctp_association *asoc,
970 const struct sctp_chunk *chunk, __u32 tsn)
972 struct sctp_chunk *retval;
975 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t)
981 /* Put the tsn back into network byte order. */
982 payload = htonl(tsn);
983 sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload));
984 sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload);
986 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
988 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
989 * HEARTBEAT ACK, * etc.) to the same destination transport
990 * address from which it * received the DATA or control chunk
991 * to which it is replying.
993 * [ABORT back to where the offender came from.]
996 retval->transport = chunk->transport;
1002 /* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */
1003 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc,
1007 struct sctp_chunk *retval;
1008 void *payload = NULL;
1011 retval = sctp_make_abort(asoc, NULL, sizeof(sctp_errhdr_t) + paylen);
1016 /* Put the msg_iov together into payload. */
1017 payload = kmalloc(paylen, GFP_KERNEL);
1021 err = memcpy_from_msg(payload, msg, paylen);
1026 sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen);
1027 sctp_addto_chunk(retval, paylen, payload);
1037 sctp_chunk_free(retval);
1043 /* Append bytes to the end of a parameter. Will panic if chunk is not big
1046 static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
1050 int chunklen = ntohs(chunk->chunk_hdr->length);
1052 target = skb_put(chunk->skb, len);
1055 memcpy(target, data, len);
1057 memset(target, 0, len);
1059 /* Adjust the chunk length field. */
1060 chunk->chunk_hdr->length = htons(chunklen + len);
1061 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1066 /* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */
1067 struct sctp_chunk *sctp_make_abort_violation(
1068 const struct sctp_association *asoc,
1069 const struct sctp_chunk *chunk,
1070 const __u8 *payload,
1071 const size_t paylen)
1073 struct sctp_chunk *retval;
1074 struct sctp_paramhdr phdr;
1076 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) + paylen
1077 + sizeof(sctp_paramhdr_t));
1081 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen
1082 + sizeof(sctp_paramhdr_t));
1084 phdr.type = htons(chunk->chunk_hdr->type);
1085 phdr.length = chunk->chunk_hdr->length;
1086 sctp_addto_chunk(retval, paylen, payload);
1087 sctp_addto_param(retval, sizeof(sctp_paramhdr_t), &phdr);
1093 struct sctp_chunk *sctp_make_violation_paramlen(
1094 const struct sctp_association *asoc,
1095 const struct sctp_chunk *chunk,
1096 struct sctp_paramhdr *param)
1098 struct sctp_chunk *retval;
1099 static const char error[] = "The following parameter had invalid length:";
1100 size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t) +
1101 sizeof(sctp_paramhdr_t);
1103 retval = sctp_make_abort(asoc, chunk, payload_len);
1107 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION,
1108 sizeof(error) + sizeof(sctp_paramhdr_t));
1109 sctp_addto_chunk(retval, sizeof(error), error);
1110 sctp_addto_param(retval, sizeof(sctp_paramhdr_t), param);
1116 struct sctp_chunk *sctp_make_violation_max_retrans(
1117 const struct sctp_association *asoc,
1118 const struct sctp_chunk *chunk)
1120 struct sctp_chunk *retval;
1121 static const char error[] = "Association exceeded its max_retans count";
1122 size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t);
1124 retval = sctp_make_abort(asoc, chunk, payload_len);
1128 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error));
1129 sctp_addto_chunk(retval, sizeof(error), error);
1135 /* Make a HEARTBEAT chunk. */
1136 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc,
1137 const struct sctp_transport *transport)
1139 struct sctp_chunk *retval;
1140 sctp_sender_hb_info_t hbinfo;
1142 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT, 0, sizeof(hbinfo));
1147 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO;
1148 hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t));
1149 hbinfo.daddr = transport->ipaddr;
1150 hbinfo.sent_at = jiffies;
1151 hbinfo.hb_nonce = transport->hb_nonce;
1153 /* Cast away the 'const', as this is just telling the chunk
1154 * what transport it belongs to.
1156 retval->transport = (struct sctp_transport *) transport;
1157 retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo),
1164 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc,
1165 const struct sctp_chunk *chunk,
1166 const void *payload, const size_t paylen)
1168 struct sctp_chunk *retval;
1170 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen);
1174 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload);
1176 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
1178 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1179 * HEARTBEAT ACK, * etc.) to the same destination transport
1180 * address from which it * received the DATA or control chunk
1181 * to which it is replying.
1183 * [HBACK back to where the HEARTBEAT came from.]
1186 retval->transport = chunk->transport;
1192 /* Create an Operation Error chunk with the specified space reserved.
1193 * This routine can be used for containing multiple causes in the chunk.
1195 static struct sctp_chunk *sctp_make_op_error_space(
1196 const struct sctp_association *asoc,
1197 const struct sctp_chunk *chunk,
1200 struct sctp_chunk *retval;
1202 retval = sctp_make_control(asoc, SCTP_CID_ERROR, 0,
1203 sizeof(sctp_errhdr_t) + size);
1207 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
1209 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1210 * HEARTBEAT ACK, etc.) to the same destination transport
1211 * address from which it received the DATA or control chunk
1212 * to which it is replying.
1216 retval->transport = chunk->transport;
1222 /* Create an Operation Error chunk of a fixed size,
1223 * specifically, max(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT)
1224 * This is a helper function to allocate an error chunk for
1225 * for those invalid parameter codes in which we may not want
1226 * to report all the errors, if the incoming chunk is large
1228 static inline struct sctp_chunk *sctp_make_op_error_fixed(
1229 const struct sctp_association *asoc,
1230 const struct sctp_chunk *chunk)
1232 size_t size = asoc ? asoc->pathmtu : 0;
1235 size = SCTP_DEFAULT_MAXSEGMENT;
1237 return sctp_make_op_error_space(asoc, chunk, size);
1240 /* Create an Operation Error chunk. */
1241 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc,
1242 const struct sctp_chunk *chunk,
1243 __be16 cause_code, const void *payload,
1244 size_t paylen, size_t reserve_tail)
1246 struct sctp_chunk *retval;
1248 retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail);
1252 sctp_init_cause(retval, cause_code, paylen + reserve_tail);
1253 sctp_addto_chunk(retval, paylen, payload);
1255 sctp_addto_param(retval, reserve_tail, NULL);
1261 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc)
1263 struct sctp_chunk *retval;
1264 struct sctp_hmac *hmac_desc;
1265 struct sctp_authhdr auth_hdr;
1268 /* Get the first hmac that the peer told us to use */
1269 hmac_desc = sctp_auth_asoc_get_hmac(asoc);
1270 if (unlikely(!hmac_desc))
1273 retval = sctp_make_control(asoc, SCTP_CID_AUTH, 0,
1274 hmac_desc->hmac_len + sizeof(sctp_authhdr_t));
1278 auth_hdr.hmac_id = htons(hmac_desc->hmac_id);
1279 auth_hdr.shkey_id = htons(asoc->active_key_id);
1281 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(sctp_authhdr_t),
1284 hmac = skb_put(retval->skb, hmac_desc->hmac_len);
1285 memset(hmac, 0, hmac_desc->hmac_len);
1287 /* Adjust the chunk header to include the empty MAC */
1288 retval->chunk_hdr->length =
1289 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len);
1290 retval->chunk_end = skb_tail_pointer(retval->skb);
1296 /********************************************************************
1297 * 2nd Level Abstractions
1298 ********************************************************************/
1300 /* Turn an skb into a chunk.
1301 * FIXME: Eventually move the structure directly inside the skb->cb[].
1303 * sctpimpguide-05.txt Section 2.8.2
1304 * M1) Each time a new DATA chunk is transmitted
1305 * set the 'TSN.Missing.Report' count for that TSN to 0. The
1306 * 'TSN.Missing.Report' count will be used to determine missing chunks
1307 * and when to fast retransmit.
1310 struct sctp_chunk *sctp_chunkify(struct sk_buff *skb,
1311 const struct sctp_association *asoc,
1314 struct sctp_chunk *retval;
1316 retval = kmem_cache_zalloc(sctp_chunk_cachep, GFP_ATOMIC);
1321 pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb);
1323 INIT_LIST_HEAD(&retval->list);
1325 retval->asoc = (struct sctp_association *)asoc;
1326 retval->singleton = 1;
1328 retval->fast_retransmit = SCTP_CAN_FRTX;
1330 /* Polish the bead hole. */
1331 INIT_LIST_HEAD(&retval->transmitted_list);
1332 INIT_LIST_HEAD(&retval->frag_list);
1333 SCTP_DBG_OBJCNT_INC(chunk);
1334 atomic_set(&retval->refcnt, 1);
1340 /* Set chunk->source and dest based on the IP header in chunk->skb. */
1341 void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src,
1342 union sctp_addr *dest)
1344 memcpy(&chunk->source, src, sizeof(union sctp_addr));
1345 memcpy(&chunk->dest, dest, sizeof(union sctp_addr));
1348 /* Extract the source address from a chunk. */
1349 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk)
1351 /* If we have a known transport, use that. */
1352 if (chunk->transport) {
1353 return &chunk->transport->ipaddr;
1355 /* Otherwise, extract it from the IP header. */
1356 return &chunk->source;
1360 /* Create a new chunk, setting the type and flags headers from the
1361 * arguments, reserving enough space for a 'paylen' byte payload.
1363 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc,
1364 __u8 type, __u8 flags, int paylen)
1366 struct sctp_chunk *retval;
1367 sctp_chunkhdr_t *chunk_hdr;
1368 struct sk_buff *skb;
1371 /* No need to allocate LL here, as this is only a chunk. */
1372 skb = alloc_skb(WORD_ROUND(sizeof(sctp_chunkhdr_t) + paylen),
1377 /* Make room for the chunk header. */
1378 chunk_hdr = (sctp_chunkhdr_t *)skb_put(skb, sizeof(sctp_chunkhdr_t));
1379 chunk_hdr->type = type;
1380 chunk_hdr->flags = flags;
1381 chunk_hdr->length = htons(sizeof(sctp_chunkhdr_t));
1383 sk = asoc ? asoc->base.sk : NULL;
1384 retval = sctp_chunkify(skb, asoc, sk);
1390 retval->chunk_hdr = chunk_hdr;
1391 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(struct sctp_chunkhdr);
1393 /* Determine if the chunk needs to be authenticated */
1394 if (sctp_auth_send_cid(type, asoc))
1402 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc,
1403 __u8 flags, int paylen)
1405 return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen);
1408 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc,
1409 __u8 type, __u8 flags, int paylen)
1411 struct sctp_chunk *chunk = _sctp_make_chunk(asoc, type, flags, paylen);
1414 sctp_control_set_owner_w(chunk);
1419 /* Release the memory occupied by a chunk. */
1420 static void sctp_chunk_destroy(struct sctp_chunk *chunk)
1422 BUG_ON(!list_empty(&chunk->list));
1423 list_del_init(&chunk->transmitted_list);
1425 consume_skb(chunk->skb);
1426 consume_skb(chunk->auth_chunk);
1428 SCTP_DBG_OBJCNT_DEC(chunk);
1429 kmem_cache_free(sctp_chunk_cachep, chunk);
1432 /* Possibly, free the chunk. */
1433 void sctp_chunk_free(struct sctp_chunk *chunk)
1435 /* Release our reference on the message tracker. */
1437 sctp_datamsg_put(chunk->msg);
1439 sctp_chunk_put(chunk);
1442 /* Grab a reference to the chunk. */
1443 void sctp_chunk_hold(struct sctp_chunk *ch)
1445 atomic_inc(&ch->refcnt);
1448 /* Release a reference to the chunk. */
1449 void sctp_chunk_put(struct sctp_chunk *ch)
1451 if (atomic_dec_and_test(&ch->refcnt))
1452 sctp_chunk_destroy(ch);
1455 /* Append bytes to the end of a chunk. Will panic if chunk is not big
1458 void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data)
1462 int chunklen = ntohs(chunk->chunk_hdr->length);
1463 int padlen = WORD_ROUND(chunklen) - chunklen;
1465 padding = skb_put(chunk->skb, padlen);
1466 target = skb_put(chunk->skb, len);
1468 memset(padding, 0, padlen);
1469 memcpy(target, data, len);
1471 /* Adjust the chunk length field. */
1472 chunk->chunk_hdr->length = htons(chunklen + padlen + len);
1473 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1478 /* Append bytes to the end of a chunk. Returns NULL if there isn't sufficient
1479 * space in the chunk
1481 static void *sctp_addto_chunk_fixed(struct sctp_chunk *chunk,
1482 int len, const void *data)
1484 if (skb_tailroom(chunk->skb) >= len)
1485 return sctp_addto_chunk(chunk, len, data);
1490 /* Append bytes from user space to the end of a chunk. Will panic if
1491 * chunk is not big enough.
1492 * Returns a kernel err value.
1494 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
1495 struct iov_iter *from)
1500 /* Make room in chunk for data. */
1501 target = skb_put(chunk->skb, len);
1503 /* Copy data (whole iovec) into chunk */
1504 copied = copy_from_iter(target, len, from);
1508 /* Adjust the chunk length field. */
1509 chunk->chunk_hdr->length =
1510 htons(ntohs(chunk->chunk_hdr->length) + len);
1511 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1516 /* Helper function to assign a TSN if needed. This assumes that both
1517 * the data_hdr and association have already been assigned.
1519 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk)
1521 struct sctp_datamsg *msg;
1522 struct sctp_chunk *lchunk;
1523 struct sctp_stream *stream;
1530 /* All fragments will be on the same stream */
1531 sid = ntohs(chunk->subh.data_hdr->stream);
1532 stream = &chunk->asoc->ssnmap->out;
1534 /* Now assign the sequence number to the entire message.
1535 * All fragments must have the same stream sequence number.
1538 list_for_each_entry(lchunk, &msg->chunks, frag_list) {
1539 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
1542 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG)
1543 ssn = sctp_ssn_next(stream, sid);
1545 ssn = sctp_ssn_peek(stream, sid);
1548 lchunk->subh.data_hdr->ssn = htons(ssn);
1549 lchunk->has_ssn = 1;
1553 /* Helper function to assign a TSN if needed. This assumes that both
1554 * the data_hdr and association have already been assigned.
1556 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk)
1558 if (!chunk->has_tsn) {
1559 /* This is the last possible instant to
1562 chunk->subh.data_hdr->tsn =
1563 htonl(sctp_association_get_next_tsn(chunk->asoc));
1568 /* Create a CLOSED association to use with an incoming packet. */
1569 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep,
1570 struct sctp_chunk *chunk,
1573 struct sctp_association *asoc;
1574 struct sk_buff *skb;
1578 /* Create the bare association. */
1579 scope = sctp_scope(sctp_source(chunk));
1580 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp);
1585 /* Create an entry for the source address of the packet. */
1586 af = sctp_get_af_specific(ipver2af(ip_hdr(skb)->version));
1589 af->from_skb(&asoc->c.peer_addr, skb, 1);
1594 sctp_association_free(asoc);
1598 /* Build a cookie representing asoc.
1599 * This INCLUDES the param header needed to put the cookie in the INIT ACK.
1601 static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep,
1602 const struct sctp_association *asoc,
1603 const struct sctp_chunk *init_chunk,
1605 const __u8 *raw_addrs, int addrs_len)
1607 sctp_cookie_param_t *retval;
1608 struct sctp_signed_cookie *cookie;
1609 int headersize, bodysize;
1611 /* Header size is static data prior to the actual cookie, including
1614 headersize = sizeof(sctp_paramhdr_t) +
1615 (sizeof(struct sctp_signed_cookie) -
1616 sizeof(struct sctp_cookie));
1617 bodysize = sizeof(struct sctp_cookie)
1618 + ntohs(init_chunk->chunk_hdr->length) + addrs_len;
1620 /* Pad out the cookie to a multiple to make the signature
1621 * functions simpler to write.
1623 if (bodysize % SCTP_COOKIE_MULTIPLE)
1624 bodysize += SCTP_COOKIE_MULTIPLE
1625 - (bodysize % SCTP_COOKIE_MULTIPLE);
1626 *cookie_len = headersize + bodysize;
1628 /* Clear this memory since we are sending this data structure
1629 * out on the network.
1631 retval = kzalloc(*cookie_len, GFP_ATOMIC);
1635 cookie = (struct sctp_signed_cookie *) retval->body;
1637 /* Set up the parameter header. */
1638 retval->p.type = SCTP_PARAM_STATE_COOKIE;
1639 retval->p.length = htons(*cookie_len);
1641 /* Copy the cookie part of the association itself. */
1642 cookie->c = asoc->c;
1643 /* Save the raw address list length in the cookie. */
1644 cookie->c.raw_addr_list_len = addrs_len;
1646 /* Remember PR-SCTP capability. */
1647 cookie->c.prsctp_capable = asoc->peer.prsctp_capable;
1649 /* Save adaptation indication in the cookie. */
1650 cookie->c.adaptation_ind = asoc->peer.adaptation_ind;
1652 /* Set an expiration time for the cookie. */
1653 cookie->c.expiration = ktime_add(asoc->cookie_life,
1656 /* Copy the peer's init packet. */
1657 memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr,
1658 ntohs(init_chunk->chunk_hdr->length));
1660 /* Copy the raw local address list of the association. */
1661 memcpy((__u8 *)&cookie->c.peer_init[0] +
1662 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len);
1664 if (sctp_sk(ep->base.sk)->hmac) {
1665 SHASH_DESC_ON_STACK(desc, sctp_sk(ep->base.sk)->hmac);
1668 /* Sign the message. */
1669 desc->tfm = sctp_sk(ep->base.sk)->hmac;
1672 err = crypto_shash_setkey(desc->tfm, ep->secret_key,
1673 sizeof(ep->secret_key)) ?:
1674 crypto_shash_digest(desc, (u8 *)&cookie->c, bodysize,
1676 shash_desc_zero(desc);
1690 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */
1691 struct sctp_association *sctp_unpack_cookie(
1692 const struct sctp_endpoint *ep,
1693 const struct sctp_association *asoc,
1694 struct sctp_chunk *chunk, gfp_t gfp,
1695 int *error, struct sctp_chunk **errp)
1697 struct sctp_association *retval = NULL;
1698 struct sctp_signed_cookie *cookie;
1699 struct sctp_cookie *bear_cookie;
1700 int headersize, bodysize, fixed_size;
1701 __u8 *digest = ep->digest;
1704 struct sk_buff *skb = chunk->skb;
1707 /* Header size is static data prior to the actual cookie, including
1710 headersize = sizeof(sctp_chunkhdr_t) +
1711 (sizeof(struct sctp_signed_cookie) -
1712 sizeof(struct sctp_cookie));
1713 bodysize = ntohs(chunk->chunk_hdr->length) - headersize;
1714 fixed_size = headersize + sizeof(struct sctp_cookie);
1716 /* Verify that the chunk looks like it even has a cookie.
1717 * There must be enough room for our cookie and our peer's
1720 len = ntohs(chunk->chunk_hdr->length);
1721 if (len < fixed_size + sizeof(struct sctp_chunkhdr))
1724 /* Verify that the cookie has been padded out. */
1725 if (bodysize % SCTP_COOKIE_MULTIPLE)
1728 /* Process the cookie. */
1729 cookie = chunk->subh.cookie_hdr;
1730 bear_cookie = &cookie->c;
1732 if (!sctp_sk(ep->base.sk)->hmac)
1735 /* Check the signature. */
1737 SHASH_DESC_ON_STACK(desc, sctp_sk(ep->base.sk)->hmac);
1740 desc->tfm = sctp_sk(ep->base.sk)->hmac;
1743 err = crypto_shash_setkey(desc->tfm, ep->secret_key,
1744 sizeof(ep->secret_key)) ?:
1745 crypto_shash_digest(desc, (u8 *)bear_cookie, bodysize,
1747 shash_desc_zero(desc);
1750 *error = -SCTP_IERROR_NOMEM;
1755 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
1756 *error = -SCTP_IERROR_BAD_SIG;
1761 /* IG Section 2.35.2:
1762 * 3) Compare the port numbers and the verification tag contained
1763 * within the COOKIE ECHO chunk to the actual port numbers and the
1764 * verification tag within the SCTP common header of the received
1765 * packet. If these values do not match the packet MUST be silently
1768 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) {
1769 *error = -SCTP_IERROR_BAD_TAG;
1773 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port ||
1774 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) {
1775 *error = -SCTP_IERROR_BAD_PORTS;
1779 /* Check to see if the cookie is stale. If there is already
1780 * an association, there is no need to check cookie's expiration
1781 * for init collision case of lost COOKIE ACK.
1782 * If skb has been timestamped, then use the stamp, otherwise
1783 * use current time. This introduces a small possibility that
1784 * that a cookie may be considered expired, but his would only slow
1785 * down the new association establishment instead of every packet.
1787 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP))
1788 kt = skb_get_ktime(skb);
1790 kt = ktime_get_real();
1792 if (!asoc && ktime_before(bear_cookie->expiration, kt)) {
1794 * Section 3.3.10.3 Stale Cookie Error (3)
1798 * Stale Cookie Error: Indicates the receipt of a valid State
1799 * Cookie that has expired.
1801 len = ntohs(chunk->chunk_hdr->length);
1802 *errp = sctp_make_op_error_space(asoc, chunk, len);
1804 suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration));
1805 __be32 n = htonl(usecs);
1807 sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE,
1809 sctp_addto_chunk(*errp, sizeof(n), &n);
1810 *error = -SCTP_IERROR_STALE_COOKIE;
1812 *error = -SCTP_IERROR_NOMEM;
1817 /* Make a new base association. */
1818 scope = sctp_scope(sctp_source(chunk));
1819 retval = sctp_association_new(ep, ep->base.sk, scope, gfp);
1821 *error = -SCTP_IERROR_NOMEM;
1825 /* Set up our peer's port number. */
1826 retval->peer.port = ntohs(chunk->sctp_hdr->source);
1828 /* Populate the association from the cookie. */
1829 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie));
1831 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie,
1833 *error = -SCTP_IERROR_NOMEM;
1837 /* Also, add the destination address. */
1838 if (list_empty(&retval->base.bind_addr.address_list)) {
1839 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest,
1840 SCTP_ADDR_SRC, GFP_ATOMIC);
1843 retval->next_tsn = retval->c.initial_tsn;
1844 retval->ctsn_ack_point = retval->next_tsn - 1;
1845 retval->addip_serial = retval->c.initial_tsn;
1846 retval->adv_peer_ack_point = retval->ctsn_ack_point;
1847 retval->peer.prsctp_capable = retval->c.prsctp_capable;
1848 retval->peer.adaptation_ind = retval->c.adaptation_ind;
1850 /* The INIT stuff will be done by the side effects. */
1855 sctp_association_free(retval);
1860 /* Yikes! The packet is either corrupt or deliberately
1863 *error = -SCTP_IERROR_MALFORMED;
1867 /********************************************************************
1868 * 3rd Level Abstractions
1869 ********************************************************************/
1871 struct __sctp_missing {
1877 * Report a missing mandatory parameter.
1879 static int sctp_process_missing_param(const struct sctp_association *asoc,
1880 sctp_param_t paramtype,
1881 struct sctp_chunk *chunk,
1882 struct sctp_chunk **errp)
1884 struct __sctp_missing report;
1887 len = WORD_ROUND(sizeof(report));
1889 /* Make an ERROR chunk, preparing enough room for
1890 * returning multiple unknown parameters.
1893 *errp = sctp_make_op_error_space(asoc, chunk, len);
1896 report.num_missing = htonl(1);
1897 report.type = paramtype;
1898 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM,
1900 sctp_addto_chunk(*errp, sizeof(report), &report);
1903 /* Stop processing this chunk. */
1907 /* Report an Invalid Mandatory Parameter. */
1908 static int sctp_process_inv_mandatory(const struct sctp_association *asoc,
1909 struct sctp_chunk *chunk,
1910 struct sctp_chunk **errp)
1912 /* Invalid Mandatory Parameter Error has no payload. */
1915 *errp = sctp_make_op_error_space(asoc, chunk, 0);
1918 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0);
1920 /* Stop processing this chunk. */
1924 static int sctp_process_inv_paramlength(const struct sctp_association *asoc,
1925 struct sctp_paramhdr *param,
1926 const struct sctp_chunk *chunk,
1927 struct sctp_chunk **errp)
1929 /* This is a fatal error. Any accumulated non-fatal errors are
1933 sctp_chunk_free(*errp);
1935 /* Create an error chunk and fill it in with our payload. */
1936 *errp = sctp_make_violation_paramlen(asoc, chunk, param);
1942 /* Do not attempt to handle the HOST_NAME parm. However, do
1943 * send back an indicator to the peer.
1945 static int sctp_process_hn_param(const struct sctp_association *asoc,
1946 union sctp_params param,
1947 struct sctp_chunk *chunk,
1948 struct sctp_chunk **errp)
1950 __u16 len = ntohs(param.p->length);
1952 /* Processing of the HOST_NAME parameter will generate an
1953 * ABORT. If we've accumulated any non-fatal errors, they
1954 * would be unrecognized parameters and we should not include
1955 * them in the ABORT.
1958 sctp_chunk_free(*errp);
1960 *errp = sctp_make_op_error_space(asoc, chunk, len);
1963 sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, len);
1964 sctp_addto_chunk(*errp, len, param.v);
1967 /* Stop processing this chunk. */
1971 static int sctp_verify_ext_param(struct net *net, union sctp_params param)
1973 __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
1975 int have_asconf = 0;
1978 for (i = 0; i < num_ext; i++) {
1979 switch (param.ext->chunks[i]) {
1983 case SCTP_CID_ASCONF:
1984 case SCTP_CID_ASCONF_ACK:
1990 /* ADD-IP Security: The draft requires us to ABORT or ignore the
1991 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this
1992 * only if ADD-IP is turned on and we are not backward-compatible
1995 if (net->sctp.addip_noauth)
1998 if (net->sctp.addip_enable && !have_auth && have_asconf)
2004 static void sctp_process_ext_param(struct sctp_association *asoc,
2005 union sctp_params param)
2007 struct net *net = sock_net(asoc->base.sk);
2008 __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
2011 for (i = 0; i < num_ext; i++) {
2012 switch (param.ext->chunks[i]) {
2013 case SCTP_CID_FWD_TSN:
2014 if (net->sctp.prsctp_enable && !asoc->peer.prsctp_capable)
2015 asoc->peer.prsctp_capable = 1;
2018 /* if the peer reports AUTH, assume that he
2021 if (asoc->ep->auth_enable)
2022 asoc->peer.auth_capable = 1;
2024 case SCTP_CID_ASCONF:
2025 case SCTP_CID_ASCONF_ACK:
2026 if (net->sctp.addip_enable)
2027 asoc->peer.asconf_capable = 1;
2035 /* RFC 3.2.1 & the Implementers Guide 2.2.
2037 * The Parameter Types are encoded such that the
2038 * highest-order two bits specify the action that must be
2039 * taken if the processing endpoint does not recognize the
2042 * 00 - Stop processing this parameter; do not process any further
2043 * parameters within this chunk
2045 * 01 - Stop processing this parameter, do not process any further
2046 * parameters within this chunk, and report the unrecognized
2047 * parameter in an 'Unrecognized Parameter' ERROR chunk.
2049 * 10 - Skip this parameter and continue processing.
2051 * 11 - Skip this parameter and continue processing but
2052 * report the unrecognized parameter in an
2053 * 'Unrecognized Parameter' ERROR chunk.
2056 * SCTP_IERROR_NO_ERROR - continue with the chunk
2057 * SCTP_IERROR_ERROR - stop and report an error.
2058 * SCTP_IERROR_NOMEME - out of memory.
2060 static sctp_ierror_t sctp_process_unk_param(const struct sctp_association *asoc,
2061 union sctp_params param,
2062 struct sctp_chunk *chunk,
2063 struct sctp_chunk **errp)
2065 int retval = SCTP_IERROR_NO_ERROR;
2067 switch (param.p->type & SCTP_PARAM_ACTION_MASK) {
2068 case SCTP_PARAM_ACTION_DISCARD:
2069 retval = SCTP_IERROR_ERROR;
2071 case SCTP_PARAM_ACTION_SKIP:
2073 case SCTP_PARAM_ACTION_DISCARD_ERR:
2074 retval = SCTP_IERROR_ERROR;
2076 case SCTP_PARAM_ACTION_SKIP_ERR:
2077 /* Make an ERROR chunk, preparing enough room for
2078 * returning multiple unknown parameters.
2081 *errp = sctp_make_op_error_fixed(asoc, chunk);
2084 if (!sctp_init_cause_fixed(*errp, SCTP_ERROR_UNKNOWN_PARAM,
2085 WORD_ROUND(ntohs(param.p->length))))
2086 sctp_addto_chunk_fixed(*errp,
2087 WORD_ROUND(ntohs(param.p->length)),
2090 /* If there is no memory for generating the ERROR
2091 * report as specified, an ABORT will be triggered
2092 * to the peer and the association won't be
2095 retval = SCTP_IERROR_NOMEM;
2105 /* Verify variable length parameters
2107 * SCTP_IERROR_ABORT - trigger an ABORT
2108 * SCTP_IERROR_NOMEM - out of memory (abort)
2109 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR
2110 * SCTP_IERROR_NO_ERROR - continue with the chunk
2112 static sctp_ierror_t sctp_verify_param(struct net *net,
2113 const struct sctp_endpoint *ep,
2114 const struct sctp_association *asoc,
2115 union sctp_params param,
2117 struct sctp_chunk *chunk,
2118 struct sctp_chunk **err_chunk)
2120 struct sctp_hmac_algo_param *hmacs;
2121 int retval = SCTP_IERROR_NO_ERROR;
2122 __u16 n_elt, id = 0;
2125 /* FIXME - This routine is not looking at each parameter per the
2126 * chunk type, i.e., unrecognized parameters should be further
2127 * identified based on the chunk id.
2130 switch (param.p->type) {
2131 case SCTP_PARAM_IPV4_ADDRESS:
2132 case SCTP_PARAM_IPV6_ADDRESS:
2133 case SCTP_PARAM_COOKIE_PRESERVATIVE:
2134 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
2135 case SCTP_PARAM_STATE_COOKIE:
2136 case SCTP_PARAM_HEARTBEAT_INFO:
2137 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
2138 case SCTP_PARAM_ECN_CAPABLE:
2139 case SCTP_PARAM_ADAPTATION_LAYER_IND:
2142 case SCTP_PARAM_SUPPORTED_EXT:
2143 if (!sctp_verify_ext_param(net, param))
2144 return SCTP_IERROR_ABORT;
2147 case SCTP_PARAM_SET_PRIMARY:
2148 if (net->sctp.addip_enable)
2152 case SCTP_PARAM_HOST_NAME_ADDRESS:
2153 /* Tell the peer, we won't support this param. */
2154 sctp_process_hn_param(asoc, param, chunk, err_chunk);
2155 retval = SCTP_IERROR_ABORT;
2158 case SCTP_PARAM_FWD_TSN_SUPPORT:
2159 if (net->sctp.prsctp_enable)
2163 case SCTP_PARAM_RANDOM:
2164 if (!ep->auth_enable)
2167 /* SCTP-AUTH: Secion 6.1
2168 * If the random number is not 32 byte long the association
2169 * MUST be aborted. The ABORT chunk SHOULD contain the error
2170 * cause 'Protocol Violation'.
2172 if (SCTP_AUTH_RANDOM_LENGTH !=
2173 ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) {
2174 sctp_process_inv_paramlength(asoc, param.p,
2176 retval = SCTP_IERROR_ABORT;
2180 case SCTP_PARAM_CHUNKS:
2181 if (!ep->auth_enable)
2184 /* SCTP-AUTH: Section 3.2
2185 * The CHUNKS parameter MUST be included once in the INIT or
2186 * INIT-ACK chunk if the sender wants to receive authenticated
2187 * chunks. Its maximum length is 260 bytes.
2189 if (260 < ntohs(param.p->length)) {
2190 sctp_process_inv_paramlength(asoc, param.p,
2192 retval = SCTP_IERROR_ABORT;
2196 case SCTP_PARAM_HMAC_ALGO:
2197 if (!ep->auth_enable)
2200 hmacs = (struct sctp_hmac_algo_param *)param.p;
2201 n_elt = (ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) >> 1;
2203 /* SCTP-AUTH: Section 6.1
2204 * The HMAC algorithm based on SHA-1 MUST be supported and
2205 * included in the HMAC-ALGO parameter.
2207 for (i = 0; i < n_elt; i++) {
2208 id = ntohs(hmacs->hmac_ids[i]);
2210 if (id == SCTP_AUTH_HMAC_ID_SHA1)
2214 if (id != SCTP_AUTH_HMAC_ID_SHA1) {
2215 sctp_process_inv_paramlength(asoc, param.p, chunk,
2217 retval = SCTP_IERROR_ABORT;
2222 pr_debug("%s: unrecognized param:%d for chunk:%d\n",
2223 __func__, ntohs(param.p->type), cid);
2225 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk);
2231 /* Verify the INIT packet before we process it. */
2232 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
2233 const struct sctp_association *asoc, sctp_cid_t cid,
2234 sctp_init_chunk_t *peer_init, struct sctp_chunk *chunk,
2235 struct sctp_chunk **errp)
2237 union sctp_params param;
2238 bool has_cookie = false;
2241 /* Check for missing mandatory parameters. Note: Initial TSN is
2242 * also mandatory, but is not checked here since the valid range
2243 * is 0..2**32-1. RFC4960, section 3.3.3.
2245 if (peer_init->init_hdr.num_outbound_streams == 0 ||
2246 peer_init->init_hdr.num_inbound_streams == 0 ||
2247 peer_init->init_hdr.init_tag == 0 ||
2248 ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW)
2249 return sctp_process_inv_mandatory(asoc, chunk, errp);
2251 sctp_walk_params(param, peer_init, init_hdr.params) {
2252 if (param.p->type == SCTP_PARAM_STATE_COOKIE)
2256 /* There is a possibility that a parameter length was bad and
2257 * in that case we would have stoped walking the parameters.
2258 * The current param.p would point at the bad one.
2259 * Current consensus on the mailing list is to generate a PROTOCOL
2260 * VIOLATION error. We build the ERROR chunk here and let the normal
2261 * error handling code build and send the packet.
2263 if (param.v != (void *)chunk->chunk_end)
2264 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp);
2266 /* The only missing mandatory param possible today is
2267 * the state cookie for an INIT-ACK chunk.
2269 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie)
2270 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE,
2273 /* Verify all the variable length parameters */
2274 sctp_walk_params(param, peer_init, init_hdr.params) {
2275 result = sctp_verify_param(net, ep, asoc, param, cid,
2278 case SCTP_IERROR_ABORT:
2279 case SCTP_IERROR_NOMEM:
2281 case SCTP_IERROR_ERROR:
2283 case SCTP_IERROR_NO_ERROR:
2288 } /* for (loop through all parameters) */
2293 /* Unpack the parameters in an INIT packet into an association.
2294 * Returns 0 on failure, else success.
2295 * FIXME: This is an association method.
2297 int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk,
2298 const union sctp_addr *peer_addr,
2299 sctp_init_chunk_t *peer_init, gfp_t gfp)
2301 struct net *net = sock_net(asoc->base.sk);
2302 union sctp_params param;
2303 struct sctp_transport *transport;
2304 struct list_head *pos, *temp;
2306 union sctp_addr addr;
2310 /* We must include the address that the INIT packet came from.
2311 * This is the only address that matters for an INIT packet.
2312 * When processing a COOKIE ECHO, we retrieve the from address
2313 * of the INIT from the cookie.
2316 /* This implementation defaults to making the first transport
2317 * added as the primary transport. The source address seems to
2318 * be a a better choice than any of the embedded addresses.
2320 if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE))
2323 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr))
2326 /* Process the initialization parameters. */
2327 sctp_walk_params(param, peer_init, init_hdr.params) {
2328 if (!src_match && (param.p->type == SCTP_PARAM_IPV4_ADDRESS ||
2329 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) {
2330 af = sctp_get_af_specific(param_type2af(param.p->type));
2331 af->from_addr_param(&addr, param.addr,
2332 chunk->sctp_hdr->source, 0);
2333 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr))
2337 if (!sctp_process_param(asoc, param, peer_addr, gfp))
2341 /* source address of chunk may not match any valid address */
2345 /* AUTH: After processing the parameters, make sure that we
2346 * have all the required info to potentially do authentications.
2348 if (asoc->peer.auth_capable && (!asoc->peer.peer_random ||
2349 !asoc->peer.peer_hmacs))
2350 asoc->peer.auth_capable = 0;
2352 /* In a non-backward compatible mode, if the peer claims
2353 * support for ADD-IP but not AUTH, the ADD-IP spec states
2354 * that we MUST ABORT the association. Section 6. The section
2355 * also give us an option to silently ignore the packet, which
2356 * is what we'll do here.
2358 if (!net->sctp.addip_noauth &&
2359 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) {
2360 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP |
2362 SCTP_PARAM_SET_PRIMARY);
2363 asoc->peer.asconf_capable = 0;
2367 /* Walk list of transports, removing transports in the UNKNOWN state. */
2368 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
2369 transport = list_entry(pos, struct sctp_transport, transports);
2370 if (transport->state == SCTP_UNKNOWN) {
2371 sctp_assoc_rm_peer(asoc, transport);
2375 /* The fixed INIT headers are always in network byte
2378 asoc->peer.i.init_tag =
2379 ntohl(peer_init->init_hdr.init_tag);
2380 asoc->peer.i.a_rwnd =
2381 ntohl(peer_init->init_hdr.a_rwnd);
2382 asoc->peer.i.num_outbound_streams =
2383 ntohs(peer_init->init_hdr.num_outbound_streams);
2384 asoc->peer.i.num_inbound_streams =
2385 ntohs(peer_init->init_hdr.num_inbound_streams);
2386 asoc->peer.i.initial_tsn =
2387 ntohl(peer_init->init_hdr.initial_tsn);
2389 /* Apply the upper bounds for output streams based on peer's
2390 * number of inbound streams.
2392 if (asoc->c.sinit_num_ostreams >
2393 ntohs(peer_init->init_hdr.num_inbound_streams)) {
2394 asoc->c.sinit_num_ostreams =
2395 ntohs(peer_init->init_hdr.num_inbound_streams);
2398 if (asoc->c.sinit_max_instreams >
2399 ntohs(peer_init->init_hdr.num_outbound_streams)) {
2400 asoc->c.sinit_max_instreams =
2401 ntohs(peer_init->init_hdr.num_outbound_streams);
2404 /* Copy Initiation tag from INIT to VT_peer in cookie. */
2405 asoc->c.peer_vtag = asoc->peer.i.init_tag;
2407 /* Peer Rwnd : Current calculated value of the peer's rwnd. */
2408 asoc->peer.rwnd = asoc->peer.i.a_rwnd;
2410 /* Copy cookie in case we need to resend COOKIE-ECHO. */
2411 cookie = asoc->peer.cookie;
2413 asoc->peer.cookie = kmemdup(cookie, asoc->peer.cookie_len, gfp);
2414 if (!asoc->peer.cookie)
2418 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily
2419 * high (for example, implementations MAY use the size of the receiver
2420 * advertised window).
2422 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
2424 transport->ssthresh = asoc->peer.i.a_rwnd;
2427 /* Set up the TSN tracking pieces. */
2428 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
2429 asoc->peer.i.initial_tsn, gfp))
2432 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
2434 * The stream sequence number in all the streams shall start
2435 * from 0 when the association is established. Also, when the
2436 * stream sequence number reaches the value 65535 the next
2437 * stream sequence number shall be set to 0.
2440 /* Allocate storage for the negotiated streams if it is not a temporary
2446 asoc->ssnmap = sctp_ssnmap_new(asoc->c.sinit_max_instreams,
2447 asoc->c.sinit_num_ostreams, gfp);
2451 error = sctp_assoc_set_id(asoc, gfp);
2456 /* ADDIP Section 4.1 ASCONF Chunk Procedures
2458 * When an endpoint has an ASCONF signaled change to be sent to the
2459 * remote endpoint it should do the following:
2461 * A2) A serial number should be assigned to the Chunk. The serial
2462 * number should be a monotonically increasing number. All serial
2463 * numbers are defined to be initialized at the start of the
2464 * association to the same value as the Initial TSN.
2466 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1;
2470 /* Release the transport structures. */
2471 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
2472 transport = list_entry(pos, struct sctp_transport, transports);
2473 if (transport->state != SCTP_ACTIVE)
2474 sctp_assoc_rm_peer(asoc, transport);
2482 /* Update asoc with the option described in param.
2484 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT
2486 * asoc is the association to update.
2487 * param is the variable length parameter to use for update.
2488 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO.
2489 * If the current packet is an INIT we want to minimize the amount of
2490 * work we do. In particular, we should not build transport
2491 * structures for the addresses.
2493 static int sctp_process_param(struct sctp_association *asoc,
2494 union sctp_params param,
2495 const union sctp_addr *peer_addr,
2498 struct net *net = sock_net(asoc->base.sk);
2499 union sctp_addr addr;
2506 union sctp_addr_param *addr_param;
2507 struct sctp_transport *t;
2508 struct sctp_endpoint *ep = asoc->ep;
2510 /* We maintain all INIT parameters in network byte order all the
2511 * time. This allows us to not worry about whether the parameters
2512 * came from a fresh INIT, and INIT ACK, or were stored in a cookie.
2514 switch (param.p->type) {
2515 case SCTP_PARAM_IPV6_ADDRESS:
2516 if (PF_INET6 != asoc->base.sk->sk_family)
2520 case SCTP_PARAM_IPV4_ADDRESS:
2521 /* v4 addresses are not allowed on v6-only socket */
2522 if (ipv6_only_sock(asoc->base.sk))
2525 af = sctp_get_af_specific(param_type2af(param.p->type));
2526 af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0);
2527 scope = sctp_scope(peer_addr);
2528 if (sctp_in_scope(net, &addr, scope))
2529 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED))
2533 case SCTP_PARAM_COOKIE_PRESERVATIVE:
2534 if (!net->sctp.cookie_preserve_enable)
2537 stale = ntohl(param.life->lifespan_increment);
2539 /* Suggested Cookie Life span increment's unit is msec,
2542 asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale);
2545 case SCTP_PARAM_HOST_NAME_ADDRESS:
2546 pr_debug("%s: unimplemented SCTP_HOST_NAME_ADDRESS\n", __func__);
2549 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
2550 /* Turn off the default values first so we'll know which
2551 * ones are really set by the peer.
2553 asoc->peer.ipv4_address = 0;
2554 asoc->peer.ipv6_address = 0;
2556 /* Assume that peer supports the address family
2557 * by which it sends a packet.
2559 if (peer_addr->sa.sa_family == AF_INET6)
2560 asoc->peer.ipv6_address = 1;
2561 else if (peer_addr->sa.sa_family == AF_INET)
2562 asoc->peer.ipv4_address = 1;
2564 /* Cycle through address types; avoid divide by 0. */
2565 sat = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
2567 sat /= sizeof(__u16);
2569 for (i = 0; i < sat; ++i) {
2570 switch (param.sat->types[i]) {
2571 case SCTP_PARAM_IPV4_ADDRESS:
2572 asoc->peer.ipv4_address = 1;
2575 case SCTP_PARAM_IPV6_ADDRESS:
2576 if (PF_INET6 == asoc->base.sk->sk_family)
2577 asoc->peer.ipv6_address = 1;
2580 case SCTP_PARAM_HOST_NAME_ADDRESS:
2581 asoc->peer.hostname_address = 1;
2584 default: /* Just ignore anything else. */
2590 case SCTP_PARAM_STATE_COOKIE:
2591 asoc->peer.cookie_len =
2592 ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
2593 asoc->peer.cookie = param.cookie->body;
2596 case SCTP_PARAM_HEARTBEAT_INFO:
2597 /* Would be odd to receive, but it causes no problems. */
2600 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
2601 /* Rejected during verify stage. */
2604 case SCTP_PARAM_ECN_CAPABLE:
2605 asoc->peer.ecn_capable = 1;
2608 case SCTP_PARAM_ADAPTATION_LAYER_IND:
2609 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind);
2612 case SCTP_PARAM_SET_PRIMARY:
2613 if (!net->sctp.addip_enable)
2616 addr_param = param.v + sizeof(sctp_addip_param_t);
2618 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
2622 af->from_addr_param(&addr, addr_param,
2623 htons(asoc->peer.port), 0);
2625 /* if the address is invalid, we can't process it.
2626 * XXX: see spec for what to do.
2628 if (!af->addr_valid(&addr, NULL, NULL))
2631 t = sctp_assoc_lookup_paddr(asoc, &addr);
2635 sctp_assoc_set_primary(asoc, t);
2638 case SCTP_PARAM_SUPPORTED_EXT:
2639 sctp_process_ext_param(asoc, param);
2642 case SCTP_PARAM_FWD_TSN_SUPPORT:
2643 if (net->sctp.prsctp_enable) {
2644 asoc->peer.prsctp_capable = 1;
2650 case SCTP_PARAM_RANDOM:
2651 if (!ep->auth_enable)
2654 /* Save peer's random parameter */
2655 asoc->peer.peer_random = kmemdup(param.p,
2656 ntohs(param.p->length), gfp);
2657 if (!asoc->peer.peer_random) {
2663 case SCTP_PARAM_HMAC_ALGO:
2664 if (!ep->auth_enable)
2667 /* Save peer's HMAC list */
2668 asoc->peer.peer_hmacs = kmemdup(param.p,
2669 ntohs(param.p->length), gfp);
2670 if (!asoc->peer.peer_hmacs) {
2675 /* Set the default HMAC the peer requested*/
2676 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo);
2679 case SCTP_PARAM_CHUNKS:
2680 if (!ep->auth_enable)
2683 asoc->peer.peer_chunks = kmemdup(param.p,
2684 ntohs(param.p->length), gfp);
2685 if (!asoc->peer.peer_chunks)
2690 /* Any unrecognized parameters should have been caught
2691 * and handled by sctp_verify_param() which should be
2692 * called prior to this routine. Simply log the error
2695 pr_debug("%s: ignoring param:%d for association:%p.\n",
2696 __func__, ntohs(param.p->type), asoc);
2703 /* Select a new verification tag. */
2704 __u32 sctp_generate_tag(const struct sctp_endpoint *ep)
2706 /* I believe that this random number generator complies with RFC1750.
2707 * A tag of 0 is reserved for special cases (e.g. INIT).
2712 get_random_bytes(&x, sizeof(__u32));
2718 /* Select an initial TSN to send during startup. */
2719 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep)
2723 get_random_bytes(&retval, sizeof(__u32));
2728 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF)
2730 * 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
2731 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2732 * | Type = 0xC1 | Chunk Flags | Chunk Length |
2733 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2735 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2736 * | Address Parameter |
2737 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2738 * | ASCONF Parameter #1 |
2739 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2743 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2744 * | ASCONF Parameter #N |
2745 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2747 * Address Parameter and other parameter will not be wrapped in this function
2749 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc,
2750 union sctp_addr *addr,
2753 sctp_addiphdr_t asconf;
2754 struct sctp_chunk *retval;
2755 int length = sizeof(asconf) + vparam_len;
2756 union sctp_addr_param addrparam;
2758 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
2760 addrlen = af->to_addr_param(addr, &addrparam);
2765 /* Create the chunk. */
2766 retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length);
2770 asconf.serial = htonl(asoc->addip_serial++);
2772 retval->subh.addip_hdr =
2773 sctp_addto_chunk(retval, sizeof(asconf), &asconf);
2774 retval->param_hdr.v =
2775 sctp_addto_chunk(retval, addrlen, &addrparam);
2781 * 3.2.1 Add IP Address
2783 * 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
2784 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2785 * | Type = 0xC001 | Length = Variable |
2786 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2787 * | ASCONF-Request Correlation ID |
2788 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2789 * | Address Parameter |
2790 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2792 * 3.2.2 Delete IP Address
2794 * 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
2795 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2796 * | Type = 0xC002 | Length = Variable |
2797 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2798 * | ASCONF-Request Correlation ID |
2799 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2800 * | Address Parameter |
2801 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2804 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc,
2805 union sctp_addr *laddr,
2806 struct sockaddr *addrs,
2810 sctp_addip_param_t param;
2811 struct sctp_chunk *retval;
2812 union sctp_addr_param addr_param;
2813 union sctp_addr *addr;
2816 int paramlen = sizeof(param);
2817 int addr_param_len = 0;
2822 /* Get total length of all the address parameters. */
2824 for (i = 0; i < addrcnt; i++) {
2826 af = sctp_get_af_specific(addr->v4.sin_family);
2827 addr_param_len = af->to_addr_param(addr, &addr_param);
2829 totallen += paramlen;
2830 totallen += addr_param_len;
2832 addr_buf += af->sockaddr_len;
2833 if (asoc->asconf_addr_del_pending && !del_pickup) {
2834 /* reuse the parameter length from the same scope one */
2835 totallen += paramlen;
2836 totallen += addr_param_len;
2839 pr_debug("%s: picked same-scope del_pending addr, "
2840 "totallen for all addresses is %d\n",
2841 __func__, totallen);
2845 /* Create an asconf chunk with the required length. */
2846 retval = sctp_make_asconf(asoc, laddr, totallen);
2850 /* Add the address parameters to the asconf chunk. */
2852 for (i = 0; i < addrcnt; i++) {
2854 af = sctp_get_af_specific(addr->v4.sin_family);
2855 addr_param_len = af->to_addr_param(addr, &addr_param);
2856 param.param_hdr.type = flags;
2857 param.param_hdr.length = htons(paramlen + addr_param_len);
2860 sctp_addto_chunk(retval, paramlen, ¶m);
2861 sctp_addto_chunk(retval, addr_param_len, &addr_param);
2863 addr_buf += af->sockaddr_len;
2865 if (flags == SCTP_PARAM_ADD_IP && del_pickup) {
2866 addr = asoc->asconf_addr_del_pending;
2867 af = sctp_get_af_specific(addr->v4.sin_family);
2868 addr_param_len = af->to_addr_param(addr, &addr_param);
2869 param.param_hdr.type = SCTP_PARAM_DEL_IP;
2870 param.param_hdr.length = htons(paramlen + addr_param_len);
2873 sctp_addto_chunk(retval, paramlen, ¶m);
2874 sctp_addto_chunk(retval, addr_param_len, &addr_param);
2880 * 3.2.4 Set Primary IP Address
2882 * 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
2883 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2884 * | Type =0xC004 | Length = Variable |
2885 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2886 * | ASCONF-Request Correlation ID |
2887 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2888 * | Address Parameter |
2889 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2891 * Create an ASCONF chunk with Set Primary IP address parameter.
2893 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
2894 union sctp_addr *addr)
2896 sctp_addip_param_t param;
2897 struct sctp_chunk *retval;
2898 int len = sizeof(param);
2899 union sctp_addr_param addrparam;
2901 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
2903 addrlen = af->to_addr_param(addr, &addrparam);
2908 /* Create the chunk and make asconf header. */
2909 retval = sctp_make_asconf(asoc, addr, len);
2913 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY;
2914 param.param_hdr.length = htons(len);
2917 sctp_addto_chunk(retval, sizeof(param), ¶m);
2918 sctp_addto_chunk(retval, addrlen, &addrparam);
2923 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK)
2925 * 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
2926 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2927 * | Type = 0x80 | Chunk Flags | Chunk Length |
2928 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2930 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2931 * | ASCONF Parameter Response#1 |
2932 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2936 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2937 * | ASCONF Parameter Response#N |
2938 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2940 * Create an ASCONF_ACK chunk with enough space for the parameter responses.
2942 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc,
2943 __u32 serial, int vparam_len)
2945 sctp_addiphdr_t asconf;
2946 struct sctp_chunk *retval;
2947 int length = sizeof(asconf) + vparam_len;
2949 /* Create the chunk. */
2950 retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length);
2954 asconf.serial = htonl(serial);
2956 retval->subh.addip_hdr =
2957 sctp_addto_chunk(retval, sizeof(asconf), &asconf);
2962 /* Add response parameters to an ASCONF_ACK chunk. */
2963 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id,
2964 __be16 err_code, sctp_addip_param_t *asconf_param)
2966 sctp_addip_param_t ack_param;
2967 sctp_errhdr_t err_param;
2968 int asconf_param_len = 0;
2969 int err_param_len = 0;
2970 __be16 response_type;
2972 if (SCTP_ERROR_NO_ERROR == err_code) {
2973 response_type = SCTP_PARAM_SUCCESS_REPORT;
2975 response_type = SCTP_PARAM_ERR_CAUSE;
2976 err_param_len = sizeof(err_param);
2979 ntohs(asconf_param->param_hdr.length);
2982 /* Add Success Indication or Error Cause Indication parameter. */
2983 ack_param.param_hdr.type = response_type;
2984 ack_param.param_hdr.length = htons(sizeof(ack_param) +
2987 ack_param.crr_id = crr_id;
2988 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param);
2990 if (SCTP_ERROR_NO_ERROR == err_code)
2993 /* Add Error Cause parameter. */
2994 err_param.cause = err_code;
2995 err_param.length = htons(err_param_len + asconf_param_len);
2996 sctp_addto_chunk(chunk, err_param_len, &err_param);
2998 /* Add the failed TLV copied from ASCONF chunk. */
3000 sctp_addto_chunk(chunk, asconf_param_len, asconf_param);
3003 /* Process a asconf parameter. */
3004 static __be16 sctp_process_asconf_param(struct sctp_association *asoc,
3005 struct sctp_chunk *asconf,
3006 sctp_addip_param_t *asconf_param)
3008 struct sctp_transport *peer;
3010 union sctp_addr addr;
3011 union sctp_addr_param *addr_param;
3013 addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t);
3015 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP &&
3016 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP &&
3017 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY)
3018 return SCTP_ERROR_UNKNOWN_PARAM;
3020 switch (addr_param->p.type) {
3021 case SCTP_PARAM_IPV6_ADDRESS:
3022 if (!asoc->peer.ipv6_address)
3023 return SCTP_ERROR_DNS_FAILED;
3025 case SCTP_PARAM_IPV4_ADDRESS:
3026 if (!asoc->peer.ipv4_address)
3027 return SCTP_ERROR_DNS_FAILED;
3030 return SCTP_ERROR_DNS_FAILED;
3033 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
3035 return SCTP_ERROR_DNS_FAILED;
3037 af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0);
3039 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast
3040 * or multicast address.
3041 * (note: wildcard is permitted and requires special handling so
3042 * make sure we check for that)
3044 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb))
3045 return SCTP_ERROR_DNS_FAILED;
3047 switch (asconf_param->param_hdr.type) {
3048 case SCTP_PARAM_ADD_IP:
3050 * If the address 0.0.0.0 or ::0 is provided, the source
3051 * address of the packet MUST be added.
3053 if (af->is_any(&addr))
3054 memcpy(&addr, &asconf->source, sizeof(addr));
3056 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address
3057 * request and does not have the local resources to add this
3058 * new address to the association, it MUST return an Error
3059 * Cause TLV set to the new error code 'Operation Refused
3060 * Due to Resource Shortage'.
3063 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED);
3065 return SCTP_ERROR_RSRC_LOW;
3067 /* Start the heartbeat timer. */
3068 if (!mod_timer(&peer->hb_timer, sctp_transport_timeout(peer)))
3069 sctp_transport_hold(peer);
3070 asoc->new_transport = peer;
3072 case SCTP_PARAM_DEL_IP:
3073 /* ADDIP 4.3 D7) If a request is received to delete the
3074 * last remaining IP address of a peer endpoint, the receiver
3075 * MUST send an Error Cause TLV with the error cause set to the
3076 * new error code 'Request to Delete Last Remaining IP Address'.
3078 if (asoc->peer.transport_count == 1)
3079 return SCTP_ERROR_DEL_LAST_IP;
3081 /* ADDIP 4.3 D8) If a request is received to delete an IP
3082 * address which is also the source address of the IP packet
3083 * which contained the ASCONF chunk, the receiver MUST reject
3084 * this request. To reject the request the receiver MUST send
3085 * an Error Cause TLV set to the new error code 'Request to
3086 * Delete Source IP Address'
3088 if (sctp_cmp_addr_exact(&asconf->source, &addr))
3089 return SCTP_ERROR_DEL_SRC_IP;
3092 * If the address 0.0.0.0 or ::0 is provided, all
3093 * addresses of the peer except the source address of the
3094 * packet MUST be deleted.
3096 if (af->is_any(&addr)) {
3097 sctp_assoc_set_primary(asoc, asconf->transport);
3098 sctp_assoc_del_nonprimary_peers(asoc,
3100 return SCTP_ERROR_NO_ERROR;
3103 /* If the address is not part of the association, the
3104 * ASCONF-ACK with Error Cause Indication Parameter
3105 * which including cause of Unresolvable Address should
3108 peer = sctp_assoc_lookup_paddr(asoc, &addr);
3110 return SCTP_ERROR_DNS_FAILED;
3112 sctp_assoc_rm_peer(asoc, peer);
3114 case SCTP_PARAM_SET_PRIMARY:
3115 /* ADDIP Section 4.2.4
3116 * If the address 0.0.0.0 or ::0 is provided, the receiver
3117 * MAY mark the source address of the packet as its
3120 if (af->is_any(&addr))
3121 memcpy(&addr.v4, sctp_source(asconf), sizeof(addr));
3123 peer = sctp_assoc_lookup_paddr(asoc, &addr);
3125 return SCTP_ERROR_DNS_FAILED;
3127 sctp_assoc_set_primary(asoc, peer);
3131 return SCTP_ERROR_NO_ERROR;
3134 /* Verify the ASCONF packet before we process it. */
3135 bool sctp_verify_asconf(const struct sctp_association *asoc,
3136 struct sctp_chunk *chunk, bool addr_param_needed,
3137 struct sctp_paramhdr **errp)
3139 sctp_addip_chunk_t *addip = (sctp_addip_chunk_t *) chunk->chunk_hdr;
3140 union sctp_params param;
3141 bool addr_param_seen = false;
3143 sctp_walk_params(param, addip, addip_hdr.params) {
3144 size_t length = ntohs(param.p->length);
3147 switch (param.p->type) {
3148 case SCTP_PARAM_ERR_CAUSE:
3150 case SCTP_PARAM_IPV4_ADDRESS:
3151 if (length != sizeof(sctp_ipv4addr_param_t))
3153 /* ensure there is only one addr param and it's in the
3154 * beginning of addip_hdr params, or we reject it.
3156 if (param.v != addip->addip_hdr.params)
3158 addr_param_seen = true;
3160 case SCTP_PARAM_IPV6_ADDRESS:
3161 if (length != sizeof(sctp_ipv6addr_param_t))
3163 if (param.v != addip->addip_hdr.params)
3165 addr_param_seen = true;
3167 case SCTP_PARAM_ADD_IP:
3168 case SCTP_PARAM_DEL_IP:
3169 case SCTP_PARAM_SET_PRIMARY:
3170 /* In ASCONF chunks, these need to be first. */
3171 if (addr_param_needed && !addr_param_seen)
3173 length = ntohs(param.addip->param_hdr.length);
3174 if (length < sizeof(sctp_addip_param_t) +
3175 sizeof(sctp_paramhdr_t))
3178 case SCTP_PARAM_SUCCESS_REPORT:
3179 case SCTP_PARAM_ADAPTATION_LAYER_IND:
3180 if (length != sizeof(sctp_addip_param_t))
3184 /* This is unkown to us, reject! */
3189 /* Remaining sanity checks. */
3190 if (addr_param_needed && !addr_param_seen)
3192 if (!addr_param_needed && addr_param_seen)
3194 if (param.v != chunk->chunk_end)
3200 /* Process an incoming ASCONF chunk with the next expected serial no. and
3201 * return an ASCONF_ACK chunk to be sent in response.
3203 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
3204 struct sctp_chunk *asconf)
3206 sctp_addip_chunk_t *addip = (sctp_addip_chunk_t *) asconf->chunk_hdr;
3207 bool all_param_pass = true;
3208 union sctp_params param;
3209 sctp_addiphdr_t *hdr;
3210 union sctp_addr_param *addr_param;
3211 sctp_addip_param_t *asconf_param;
3212 struct sctp_chunk *asconf_ack;
3218 chunk_len = ntohs(asconf->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
3219 hdr = (sctp_addiphdr_t *)asconf->skb->data;
3220 serial = ntohl(hdr->serial);
3222 /* Skip the addiphdr and store a pointer to address parameter. */
3223 length = sizeof(sctp_addiphdr_t);
3224 addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
3225 chunk_len -= length;
3227 /* Skip the address parameter and store a pointer to the first
3230 length = ntohs(addr_param->p.length);
3231 asconf_param = (void *)addr_param + length;
3232 chunk_len -= length;
3234 /* create an ASCONF_ACK chunk.
3235 * Based on the definitions of parameters, we know that the size of
3236 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF
3239 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4);
3243 /* Process the TLVs contained within the ASCONF chunk. */
3244 sctp_walk_params(param, addip, addip_hdr.params) {
3245 /* Skip preceeding address parameters. */
3246 if (param.p->type == SCTP_PARAM_IPV4_ADDRESS ||
3247 param.p->type == SCTP_PARAM_IPV6_ADDRESS)
3250 err_code = sctp_process_asconf_param(asoc, asconf,
3253 * If an error response is received for a TLV parameter,
3254 * all TLVs with no response before the failed TLV are
3255 * considered successful if not reported. All TLVs after
3256 * the failed response are considered unsuccessful unless
3257 * a specific success indication is present for the parameter.
3259 if (err_code != SCTP_ERROR_NO_ERROR)
3260 all_param_pass = false;
3261 if (!all_param_pass)
3262 sctp_add_asconf_response(asconf_ack, param.addip->crr_id,
3263 err_code, param.addip);
3265 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add
3266 * an IP address sends an 'Out of Resource' in its response, it
3267 * MUST also fail any subsequent add or delete requests bundled
3270 if (err_code == SCTP_ERROR_RSRC_LOW)
3274 asoc->peer.addip_serial++;
3276 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc
3277 * after freeing the reference to old asconf ack if any.
3280 sctp_chunk_hold(asconf_ack);
3281 list_add_tail(&asconf_ack->transmitted_list,
3282 &asoc->asconf_ack_list);
3288 /* Process a asconf parameter that is successfully acked. */
3289 static void sctp_asconf_param_success(struct sctp_association *asoc,
3290 sctp_addip_param_t *asconf_param)
3293 union sctp_addr addr;
3294 struct sctp_bind_addr *bp = &asoc->base.bind_addr;
3295 union sctp_addr_param *addr_param;
3296 struct sctp_transport *transport;
3297 struct sctp_sockaddr_entry *saddr;
3299 addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t);
3301 /* We have checked the packet before, so we do not check again. */
3302 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
3303 af->from_addr_param(&addr, addr_param, htons(bp->port), 0);
3305 switch (asconf_param->param_hdr.type) {
3306 case SCTP_PARAM_ADD_IP:
3307 /* This is always done in BH context with a socket lock
3308 * held, so the list can not change.
3311 list_for_each_entry(saddr, &bp->address_list, list) {
3312 if (sctp_cmp_addr_exact(&saddr->a, &addr))
3313 saddr->state = SCTP_ADDR_SRC;
3316 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
3318 dst_release(transport->dst);
3319 transport->dst = NULL;
3322 case SCTP_PARAM_DEL_IP:
3324 sctp_del_bind_addr(bp, &addr);
3325 if (asoc->asconf_addr_del_pending != NULL &&
3326 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) {
3327 kfree(asoc->asconf_addr_del_pending);
3328 asoc->asconf_addr_del_pending = NULL;
3331 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
3333 dst_release(transport->dst);
3334 transport->dst = NULL;
3342 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk
3343 * for the given asconf parameter. If there is no response for this parameter,
3344 * return the error code based on the third argument 'no_err'.
3346 * A7) If an error response is received for a TLV parameter, all TLVs with no
3347 * response before the failed TLV are considered successful if not reported.
3348 * All TLVs after the failed response are considered unsuccessful unless a
3349 * specific success indication is present for the parameter.
3351 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack,
3352 sctp_addip_param_t *asconf_param,
3355 sctp_addip_param_t *asconf_ack_param;
3356 sctp_errhdr_t *err_param;
3362 err_code = SCTP_ERROR_NO_ERROR;
3364 err_code = SCTP_ERROR_REQ_REFUSED;
3366 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) -
3367 sizeof(sctp_chunkhdr_t);
3369 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to
3370 * the first asconf_ack parameter.
3372 length = sizeof(sctp_addiphdr_t);
3373 asconf_ack_param = (sctp_addip_param_t *)(asconf_ack->skb->data +
3375 asconf_ack_len -= length;
3377 while (asconf_ack_len > 0) {
3378 if (asconf_ack_param->crr_id == asconf_param->crr_id) {
3379 switch (asconf_ack_param->param_hdr.type) {
3380 case SCTP_PARAM_SUCCESS_REPORT:
3381 return SCTP_ERROR_NO_ERROR;
3382 case SCTP_PARAM_ERR_CAUSE:
3383 length = sizeof(sctp_addip_param_t);
3384 err_param = (void *)asconf_ack_param + length;
3385 asconf_ack_len -= length;
3386 if (asconf_ack_len > 0)
3387 return err_param->cause;
3389 return SCTP_ERROR_INV_PARAM;
3392 return SCTP_ERROR_INV_PARAM;
3396 length = ntohs(asconf_ack_param->param_hdr.length);
3397 asconf_ack_param = (void *)asconf_ack_param + length;
3398 asconf_ack_len -= length;
3404 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */
3405 int sctp_process_asconf_ack(struct sctp_association *asoc,
3406 struct sctp_chunk *asconf_ack)
3408 struct sctp_chunk *asconf = asoc->addip_last_asconf;
3409 union sctp_addr_param *addr_param;
3410 sctp_addip_param_t *asconf_param;
3412 int asconf_len = asconf->skb->len;
3413 int all_param_pass = 0;
3416 __be16 err_code = SCTP_ERROR_NO_ERROR;
3418 /* Skip the chunkhdr and addiphdr from the last asconf sent and store
3419 * a pointer to address parameter.
3421 length = sizeof(sctp_addip_chunk_t);
3422 addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
3423 asconf_len -= length;
3425 /* Skip the address parameter in the last asconf sent and store a
3426 * pointer to the first asconf parameter.
3428 length = ntohs(addr_param->p.length);
3429 asconf_param = (void *)addr_param + length;
3430 asconf_len -= length;
3433 * A8) If there is no response(s) to specific TLV parameter(s), and no
3434 * failures are indicated, then all request(s) are considered
3437 if (asconf_ack->skb->len == sizeof(sctp_addiphdr_t))
3440 /* Process the TLVs contained in the last sent ASCONF chunk. */
3441 while (asconf_len > 0) {
3443 err_code = SCTP_ERROR_NO_ERROR;
3445 err_code = sctp_get_asconf_response(asconf_ack,
3448 if (no_err && (SCTP_ERROR_NO_ERROR != err_code))
3453 case SCTP_ERROR_NO_ERROR:
3454 sctp_asconf_param_success(asoc, asconf_param);
3457 case SCTP_ERROR_RSRC_LOW:
3461 case SCTP_ERROR_UNKNOWN_PARAM:
3462 /* Disable sending this type of asconf parameter in
3465 asoc->peer.addip_disabled_mask |=
3466 asconf_param->param_hdr.type;
3469 case SCTP_ERROR_REQ_REFUSED:
3470 case SCTP_ERROR_DEL_LAST_IP:
3471 case SCTP_ERROR_DEL_SRC_IP:
3476 /* Skip the processed asconf parameter and move to the next
3479 length = ntohs(asconf_param->param_hdr.length);
3480 asconf_param = (void *)asconf_param + length;
3481 asconf_len -= length;
3484 if (no_err && asoc->src_out_of_asoc_ok) {
3485 asoc->src_out_of_asoc_ok = 0;
3486 sctp_transport_immediate_rtx(asoc->peer.primary_path);
3489 /* Free the cached last sent asconf chunk. */
3490 list_del_init(&asconf->transmitted_list);
3491 sctp_chunk_free(asconf);
3492 asoc->addip_last_asconf = NULL;
3497 /* Make a FWD TSN chunk. */
3498 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
3499 __u32 new_cum_tsn, size_t nstreams,
3500 struct sctp_fwdtsn_skip *skiplist)
3502 struct sctp_chunk *retval = NULL;
3503 struct sctp_fwdtsn_hdr ftsn_hdr;
3504 struct sctp_fwdtsn_skip skip;
3508 hint = (nstreams + 1) * sizeof(__u32);
3510 retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint);
3515 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn);
3516 retval->subh.fwdtsn_hdr =
3517 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr);
3519 for (i = 0; i < nstreams; i++) {
3520 skip.stream = skiplist[i].stream;
3521 skip.ssn = skiplist[i].ssn;
3522 sctp_addto_chunk(retval, sizeof(skip), &skip);