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 <linux/types.h>
49 #include <linux/kernel.h>
51 #include <linux/ipv6.h>
52 #include <linux/net.h>
53 #include <linux/inet.h>
54 #include <linux/scatterlist.h>
55 #include <linux/crypto.h>
56 #include <linux/slab.h>
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 if (chunk && chunk->asoc)
861 ctsn = sctp_tsnmap_get_ctsn(&chunk->asoc->peer.tsn_map);
863 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
865 shut.cum_tsn_ack = htonl(ctsn);
867 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN, 0,
868 sizeof(sctp_shutdownhdr_t));
872 retval->subh.shutdown_hdr =
873 sctp_addto_chunk(retval, sizeof(shut), &shut);
876 retval->transport = chunk->transport;
881 struct sctp_chunk *sctp_make_shutdown_ack(const struct sctp_association *asoc,
882 const struct sctp_chunk *chunk)
884 struct sctp_chunk *retval;
886 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_ACK, 0, 0);
888 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
890 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
891 * HEARTBEAT ACK, * etc.) to the same destination transport
892 * address from which it * received the DATA or control chunk
893 * to which it is replying.
895 * [ACK back to where the SHUTDOWN came from.]
898 retval->transport = chunk->transport;
903 struct sctp_chunk *sctp_make_shutdown_complete(
904 const struct sctp_association *asoc,
905 const struct sctp_chunk *chunk)
907 struct sctp_chunk *retval;
910 /* Set the T-bit if we have no association (vtag will be
913 flags |= asoc ? 0 : SCTP_CHUNK_FLAG_T;
915 retval = sctp_make_control(asoc, SCTP_CID_SHUTDOWN_COMPLETE, flags, 0);
917 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
919 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
920 * HEARTBEAT ACK, * etc.) to the same destination transport
921 * address from which it * received the DATA or control chunk
922 * to which it is replying.
924 * [Report SHUTDOWN COMPLETE back to where the SHUTDOWN ACK
928 retval->transport = chunk->transport;
933 /* Create an ABORT. Note that we set the T bit if we have no
934 * association, except when responding to an INIT (sctpimpguide 2.41).
936 struct sctp_chunk *sctp_make_abort(const struct sctp_association *asoc,
937 const struct sctp_chunk *chunk,
940 struct sctp_chunk *retval;
943 /* Set the T-bit if we have no association and 'chunk' is not
944 * an INIT (vtag will be reflected).
947 if (chunk && chunk->chunk_hdr &&
948 chunk->chunk_hdr->type == SCTP_CID_INIT)
951 flags = SCTP_CHUNK_FLAG_T;
954 retval = sctp_make_control(asoc, SCTP_CID_ABORT, flags, hint);
956 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
958 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
959 * HEARTBEAT ACK, * etc.) to the same destination transport
960 * address from which it * received the DATA or control chunk
961 * to which it is replying.
963 * [ABORT back to where the offender came from.]
966 retval->transport = chunk->transport;
971 /* Helper to create ABORT with a NO_USER_DATA error. */
972 struct sctp_chunk *sctp_make_abort_no_data(
973 const struct sctp_association *asoc,
974 const struct sctp_chunk *chunk, __u32 tsn)
976 struct sctp_chunk *retval;
979 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t)
985 /* Put the tsn back into network byte order. */
986 payload = htonl(tsn);
987 sctp_init_cause(retval, SCTP_ERROR_NO_DATA, sizeof(payload));
988 sctp_addto_chunk(retval, sizeof(payload), (const void *)&payload);
990 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
992 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
993 * HEARTBEAT ACK, * etc.) to the same destination transport
994 * address from which it * received the DATA or control chunk
995 * to which it is replying.
997 * [ABORT back to where the offender came from.]
1000 retval->transport = chunk->transport;
1006 /* Helper to create ABORT with a SCTP_ERROR_USER_ABORT error. */
1007 struct sctp_chunk *sctp_make_abort_user(const struct sctp_association *asoc,
1011 struct sctp_chunk *retval;
1012 void *payload = NULL;
1015 retval = sctp_make_abort(asoc, NULL, sizeof(sctp_errhdr_t) + paylen);
1020 /* Put the msg_iov together into payload. */
1021 payload = kmalloc(paylen, GFP_KERNEL);
1025 err = memcpy_from_msg(payload, msg, paylen);
1030 sctp_init_cause(retval, SCTP_ERROR_USER_ABORT, paylen);
1031 sctp_addto_chunk(retval, paylen, payload);
1041 sctp_chunk_free(retval);
1047 /* Append bytes to the end of a parameter. Will panic if chunk is not big
1050 static void *sctp_addto_param(struct sctp_chunk *chunk, int len,
1054 int chunklen = ntohs(chunk->chunk_hdr->length);
1056 target = skb_put(chunk->skb, len);
1059 memcpy(target, data, len);
1061 memset(target, 0, len);
1063 /* Adjust the chunk length field. */
1064 chunk->chunk_hdr->length = htons(chunklen + len);
1065 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1070 /* Make an ABORT chunk with a PROTOCOL VIOLATION cause code. */
1071 struct sctp_chunk *sctp_make_abort_violation(
1072 const struct sctp_association *asoc,
1073 const struct sctp_chunk *chunk,
1074 const __u8 *payload,
1075 const size_t paylen)
1077 struct sctp_chunk *retval;
1078 struct sctp_paramhdr phdr;
1080 retval = sctp_make_abort(asoc, chunk, sizeof(sctp_errhdr_t) + paylen
1081 + sizeof(sctp_paramhdr_t));
1085 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, paylen
1086 + sizeof(sctp_paramhdr_t));
1088 phdr.type = htons(chunk->chunk_hdr->type);
1089 phdr.length = chunk->chunk_hdr->length;
1090 sctp_addto_chunk(retval, paylen, payload);
1091 sctp_addto_param(retval, sizeof(sctp_paramhdr_t), &phdr);
1097 struct sctp_chunk *sctp_make_violation_paramlen(
1098 const struct sctp_association *asoc,
1099 const struct sctp_chunk *chunk,
1100 struct sctp_paramhdr *param)
1102 struct sctp_chunk *retval;
1103 static const char error[] = "The following parameter had invalid length:";
1104 size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t) +
1105 sizeof(sctp_paramhdr_t);
1107 retval = sctp_make_abort(asoc, chunk, payload_len);
1111 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION,
1112 sizeof(error) + sizeof(sctp_paramhdr_t));
1113 sctp_addto_chunk(retval, sizeof(error), error);
1114 sctp_addto_param(retval, sizeof(sctp_paramhdr_t), param);
1120 struct sctp_chunk *sctp_make_violation_max_retrans(
1121 const struct sctp_association *asoc,
1122 const struct sctp_chunk *chunk)
1124 struct sctp_chunk *retval;
1125 static const char error[] = "Association exceeded its max_retans count";
1126 size_t payload_len = sizeof(error) + sizeof(sctp_errhdr_t);
1128 retval = sctp_make_abort(asoc, chunk, payload_len);
1132 sctp_init_cause(retval, SCTP_ERROR_PROTO_VIOLATION, sizeof(error));
1133 sctp_addto_chunk(retval, sizeof(error), error);
1139 /* Make a HEARTBEAT chunk. */
1140 struct sctp_chunk *sctp_make_heartbeat(const struct sctp_association *asoc,
1141 const struct sctp_transport *transport)
1143 struct sctp_chunk *retval;
1144 sctp_sender_hb_info_t hbinfo;
1146 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT, 0, sizeof(hbinfo));
1151 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO;
1152 hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t));
1153 hbinfo.daddr = transport->ipaddr;
1154 hbinfo.sent_at = jiffies;
1155 hbinfo.hb_nonce = transport->hb_nonce;
1157 /* Cast away the 'const', as this is just telling the chunk
1158 * what transport it belongs to.
1160 retval->transport = (struct sctp_transport *) transport;
1161 retval->subh.hbs_hdr = sctp_addto_chunk(retval, sizeof(hbinfo),
1168 struct sctp_chunk *sctp_make_heartbeat_ack(const struct sctp_association *asoc,
1169 const struct sctp_chunk *chunk,
1170 const void *payload, const size_t paylen)
1172 struct sctp_chunk *retval;
1174 retval = sctp_make_control(asoc, SCTP_CID_HEARTBEAT_ACK, 0, paylen);
1178 retval->subh.hbs_hdr = sctp_addto_chunk(retval, paylen, payload);
1180 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
1182 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1183 * HEARTBEAT ACK, * etc.) to the same destination transport
1184 * address from which it * received the DATA or control chunk
1185 * to which it is replying.
1187 * [HBACK back to where the HEARTBEAT came from.]
1190 retval->transport = chunk->transport;
1196 /* Create an Operation Error chunk with the specified space reserved.
1197 * This routine can be used for containing multiple causes in the chunk.
1199 static struct sctp_chunk *sctp_make_op_error_space(
1200 const struct sctp_association *asoc,
1201 const struct sctp_chunk *chunk,
1204 struct sctp_chunk *retval;
1206 retval = sctp_make_control(asoc, SCTP_CID_ERROR, 0,
1207 sizeof(sctp_errhdr_t) + size);
1211 /* RFC 2960 6.4 Multi-homed SCTP Endpoints
1213 * An endpoint SHOULD transmit reply chunks (e.g., SACK,
1214 * HEARTBEAT ACK, etc.) to the same destination transport
1215 * address from which it received the DATA or control chunk
1216 * to which it is replying.
1220 retval->transport = chunk->transport;
1226 /* Create an Operation Error chunk of a fixed size,
1227 * specifically, max(asoc->pathmtu, SCTP_DEFAULT_MAXSEGMENT)
1228 * This is a helper function to allocate an error chunk for
1229 * for those invalid parameter codes in which we may not want
1230 * to report all the errors, if the incoming chunk is large
1232 static inline struct sctp_chunk *sctp_make_op_error_fixed(
1233 const struct sctp_association *asoc,
1234 const struct sctp_chunk *chunk)
1236 size_t size = asoc ? asoc->pathmtu : 0;
1239 size = SCTP_DEFAULT_MAXSEGMENT;
1241 return sctp_make_op_error_space(asoc, chunk, size);
1244 /* Create an Operation Error chunk. */
1245 struct sctp_chunk *sctp_make_op_error(const struct sctp_association *asoc,
1246 const struct sctp_chunk *chunk,
1247 __be16 cause_code, const void *payload,
1248 size_t paylen, size_t reserve_tail)
1250 struct sctp_chunk *retval;
1252 retval = sctp_make_op_error_space(asoc, chunk, paylen + reserve_tail);
1256 sctp_init_cause(retval, cause_code, paylen + reserve_tail);
1257 sctp_addto_chunk(retval, paylen, payload);
1259 sctp_addto_param(retval, reserve_tail, NULL);
1265 struct sctp_chunk *sctp_make_auth(const struct sctp_association *asoc)
1267 struct sctp_chunk *retval;
1268 struct sctp_hmac *hmac_desc;
1269 struct sctp_authhdr auth_hdr;
1272 /* Get the first hmac that the peer told us to use */
1273 hmac_desc = sctp_auth_asoc_get_hmac(asoc);
1274 if (unlikely(!hmac_desc))
1277 retval = sctp_make_control(asoc, SCTP_CID_AUTH, 0,
1278 hmac_desc->hmac_len + sizeof(sctp_authhdr_t));
1282 auth_hdr.hmac_id = htons(hmac_desc->hmac_id);
1283 auth_hdr.shkey_id = htons(asoc->active_key_id);
1285 retval->subh.auth_hdr = sctp_addto_chunk(retval, sizeof(sctp_authhdr_t),
1288 hmac = skb_put(retval->skb, hmac_desc->hmac_len);
1289 memset(hmac, 0, hmac_desc->hmac_len);
1291 /* Adjust the chunk header to include the empty MAC */
1292 retval->chunk_hdr->length =
1293 htons(ntohs(retval->chunk_hdr->length) + hmac_desc->hmac_len);
1294 retval->chunk_end = skb_tail_pointer(retval->skb);
1300 /********************************************************************
1301 * 2nd Level Abstractions
1302 ********************************************************************/
1304 /* Turn an skb into a chunk.
1305 * FIXME: Eventually move the structure directly inside the skb->cb[].
1307 * sctpimpguide-05.txt Section 2.8.2
1308 * M1) Each time a new DATA chunk is transmitted
1309 * set the 'TSN.Missing.Report' count for that TSN to 0. The
1310 * 'TSN.Missing.Report' count will be used to determine missing chunks
1311 * and when to fast retransmit.
1314 struct sctp_chunk *sctp_chunkify(struct sk_buff *skb,
1315 const struct sctp_association *asoc,
1318 struct sctp_chunk *retval;
1320 retval = kmem_cache_zalloc(sctp_chunk_cachep, GFP_ATOMIC);
1325 pr_debug("%s: chunkifying skb:%p w/o an sk\n", __func__, skb);
1327 INIT_LIST_HEAD(&retval->list);
1329 retval->asoc = (struct sctp_association *)asoc;
1330 retval->singleton = 1;
1332 retval->fast_retransmit = SCTP_CAN_FRTX;
1334 /* Polish the bead hole. */
1335 INIT_LIST_HEAD(&retval->transmitted_list);
1336 INIT_LIST_HEAD(&retval->frag_list);
1337 SCTP_DBG_OBJCNT_INC(chunk);
1338 atomic_set(&retval->refcnt, 1);
1344 /* Set chunk->source and dest based on the IP header in chunk->skb. */
1345 void sctp_init_addrs(struct sctp_chunk *chunk, union sctp_addr *src,
1346 union sctp_addr *dest)
1348 memcpy(&chunk->source, src, sizeof(union sctp_addr));
1349 memcpy(&chunk->dest, dest, sizeof(union sctp_addr));
1352 /* Extract the source address from a chunk. */
1353 const union sctp_addr *sctp_source(const struct sctp_chunk *chunk)
1355 /* If we have a known transport, use that. */
1356 if (chunk->transport) {
1357 return &chunk->transport->ipaddr;
1359 /* Otherwise, extract it from the IP header. */
1360 return &chunk->source;
1364 /* Create a new chunk, setting the type and flags headers from the
1365 * arguments, reserving enough space for a 'paylen' byte payload.
1367 static struct sctp_chunk *_sctp_make_chunk(const struct sctp_association *asoc,
1368 __u8 type, __u8 flags, int paylen)
1370 struct sctp_chunk *retval;
1371 sctp_chunkhdr_t *chunk_hdr;
1372 struct sk_buff *skb;
1376 chunklen = WORD_ROUND(sizeof(*chunk_hdr) + paylen);
1377 if (chunklen > SCTP_MAX_CHUNK_LEN)
1380 /* No need to allocate LL here, as this is only a chunk. */
1381 skb = alloc_skb(chunklen, GFP_ATOMIC);
1385 /* Make room for the chunk header. */
1386 chunk_hdr = (sctp_chunkhdr_t *)skb_put(skb, sizeof(sctp_chunkhdr_t));
1387 chunk_hdr->type = type;
1388 chunk_hdr->flags = flags;
1389 chunk_hdr->length = htons(sizeof(sctp_chunkhdr_t));
1391 sk = asoc ? asoc->base.sk : NULL;
1392 retval = sctp_chunkify(skb, asoc, sk);
1398 retval->chunk_hdr = chunk_hdr;
1399 retval->chunk_end = ((__u8 *)chunk_hdr) + sizeof(struct sctp_chunkhdr);
1401 /* Determine if the chunk needs to be authenticated */
1402 if (sctp_auth_send_cid(type, asoc))
1410 static struct sctp_chunk *sctp_make_data(const struct sctp_association *asoc,
1411 __u8 flags, int paylen)
1413 return _sctp_make_chunk(asoc, SCTP_CID_DATA, flags, paylen);
1416 static struct sctp_chunk *sctp_make_control(const struct sctp_association *asoc,
1417 __u8 type, __u8 flags, int paylen)
1419 struct sctp_chunk *chunk = _sctp_make_chunk(asoc, type, flags, paylen);
1422 sctp_control_set_owner_w(chunk);
1427 /* Release the memory occupied by a chunk. */
1428 static void sctp_chunk_destroy(struct sctp_chunk *chunk)
1430 BUG_ON(!list_empty(&chunk->list));
1431 list_del_init(&chunk->transmitted_list);
1433 consume_skb(chunk->skb);
1434 consume_skb(chunk->auth_chunk);
1436 SCTP_DBG_OBJCNT_DEC(chunk);
1437 kmem_cache_free(sctp_chunk_cachep, chunk);
1440 /* Possibly, free the chunk. */
1441 void sctp_chunk_free(struct sctp_chunk *chunk)
1443 /* Release our reference on the message tracker. */
1445 sctp_datamsg_put(chunk->msg);
1447 sctp_chunk_put(chunk);
1450 /* Grab a reference to the chunk. */
1451 void sctp_chunk_hold(struct sctp_chunk *ch)
1453 atomic_inc(&ch->refcnt);
1456 /* Release a reference to the chunk. */
1457 void sctp_chunk_put(struct sctp_chunk *ch)
1459 if (atomic_dec_and_test(&ch->refcnt))
1460 sctp_chunk_destroy(ch);
1463 /* Append bytes to the end of a chunk. Will panic if chunk is not big
1466 void *sctp_addto_chunk(struct sctp_chunk *chunk, int len, const void *data)
1470 int chunklen = ntohs(chunk->chunk_hdr->length);
1471 int padlen = WORD_ROUND(chunklen) - chunklen;
1473 padding = skb_put(chunk->skb, padlen);
1474 target = skb_put(chunk->skb, len);
1476 memset(padding, 0, padlen);
1477 memcpy(target, data, len);
1479 /* Adjust the chunk length field. */
1480 chunk->chunk_hdr->length = htons(chunklen + padlen + len);
1481 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1486 /* Append bytes to the end of a chunk. Returns NULL if there isn't sufficient
1487 * space in the chunk
1489 static void *sctp_addto_chunk_fixed(struct sctp_chunk *chunk,
1490 int len, const void *data)
1492 if (skb_tailroom(chunk->skb) >= len)
1493 return sctp_addto_chunk(chunk, len, data);
1498 /* Append bytes from user space to the end of a chunk. Will panic if
1499 * chunk is not big enough.
1500 * Returns a kernel err value.
1502 int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
1503 struct iov_iter *from)
1508 /* Make room in chunk for data. */
1509 target = skb_put(chunk->skb, len);
1511 /* Copy data (whole iovec) into chunk */
1512 copied = copy_from_iter(target, len, from);
1516 /* Adjust the chunk length field. */
1517 chunk->chunk_hdr->length =
1518 htons(ntohs(chunk->chunk_hdr->length) + len);
1519 chunk->chunk_end = skb_tail_pointer(chunk->skb);
1524 /* Helper function to assign a TSN if needed. This assumes that both
1525 * the data_hdr and association have already been assigned.
1527 void sctp_chunk_assign_ssn(struct sctp_chunk *chunk)
1529 struct sctp_datamsg *msg;
1530 struct sctp_chunk *lchunk;
1531 struct sctp_stream *stream;
1538 /* All fragments will be on the same stream */
1539 sid = ntohs(chunk->subh.data_hdr->stream);
1540 stream = &chunk->asoc->ssnmap->out;
1542 /* Now assign the sequence number to the entire message.
1543 * All fragments must have the same stream sequence number.
1546 list_for_each_entry(lchunk, &msg->chunks, frag_list) {
1547 if (lchunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
1550 if (lchunk->chunk_hdr->flags & SCTP_DATA_LAST_FRAG)
1551 ssn = sctp_ssn_next(stream, sid);
1553 ssn = sctp_ssn_peek(stream, sid);
1556 lchunk->subh.data_hdr->ssn = htons(ssn);
1557 lchunk->has_ssn = 1;
1561 /* Helper function to assign a TSN if needed. This assumes that both
1562 * the data_hdr and association have already been assigned.
1564 void sctp_chunk_assign_tsn(struct sctp_chunk *chunk)
1566 if (!chunk->has_tsn) {
1567 /* This is the last possible instant to
1570 chunk->subh.data_hdr->tsn =
1571 htonl(sctp_association_get_next_tsn(chunk->asoc));
1576 /* Create a CLOSED association to use with an incoming packet. */
1577 struct sctp_association *sctp_make_temp_asoc(const struct sctp_endpoint *ep,
1578 struct sctp_chunk *chunk,
1581 struct sctp_association *asoc;
1582 struct sk_buff *skb;
1586 /* Create the bare association. */
1587 scope = sctp_scope(sctp_source(chunk));
1588 asoc = sctp_association_new(ep, ep->base.sk, scope, gfp);
1593 /* Create an entry for the source address of the packet. */
1594 af = sctp_get_af_specific(ipver2af(ip_hdr(skb)->version));
1597 af->from_skb(&asoc->c.peer_addr, skb, 1);
1602 sctp_association_free(asoc);
1606 /* Build a cookie representing asoc.
1607 * This INCLUDES the param header needed to put the cookie in the INIT ACK.
1609 static sctp_cookie_param_t *sctp_pack_cookie(const struct sctp_endpoint *ep,
1610 const struct sctp_association *asoc,
1611 const struct sctp_chunk *init_chunk,
1613 const __u8 *raw_addrs, int addrs_len)
1615 sctp_cookie_param_t *retval;
1616 struct sctp_signed_cookie *cookie;
1617 struct scatterlist sg;
1618 int headersize, bodysize;
1620 /* Header size is static data prior to the actual cookie, including
1623 headersize = sizeof(sctp_paramhdr_t) +
1624 (sizeof(struct sctp_signed_cookie) -
1625 sizeof(struct sctp_cookie));
1626 bodysize = sizeof(struct sctp_cookie)
1627 + ntohs(init_chunk->chunk_hdr->length) + addrs_len;
1629 /* Pad out the cookie to a multiple to make the signature
1630 * functions simpler to write.
1632 if (bodysize % SCTP_COOKIE_MULTIPLE)
1633 bodysize += SCTP_COOKIE_MULTIPLE
1634 - (bodysize % SCTP_COOKIE_MULTIPLE);
1635 *cookie_len = headersize + bodysize;
1637 /* Clear this memory since we are sending this data structure
1638 * out on the network.
1640 retval = kzalloc(*cookie_len, GFP_ATOMIC);
1644 cookie = (struct sctp_signed_cookie *) retval->body;
1646 /* Set up the parameter header. */
1647 retval->p.type = SCTP_PARAM_STATE_COOKIE;
1648 retval->p.length = htons(*cookie_len);
1650 /* Copy the cookie part of the association itself. */
1651 cookie->c = asoc->c;
1652 /* Save the raw address list length in the cookie. */
1653 cookie->c.raw_addr_list_len = addrs_len;
1655 /* Remember PR-SCTP capability. */
1656 cookie->c.prsctp_capable = asoc->peer.prsctp_capable;
1658 /* Save adaptation indication in the cookie. */
1659 cookie->c.adaptation_ind = asoc->peer.adaptation_ind;
1661 /* Set an expiration time for the cookie. */
1662 cookie->c.expiration = ktime_add(asoc->cookie_life,
1665 /* Copy the peer's init packet. */
1666 memcpy(&cookie->c.peer_init[0], init_chunk->chunk_hdr,
1667 ntohs(init_chunk->chunk_hdr->length));
1669 /* Copy the raw local address list of the association. */
1670 memcpy((__u8 *)&cookie->c.peer_init[0] +
1671 ntohs(init_chunk->chunk_hdr->length), raw_addrs, addrs_len);
1673 if (sctp_sk(ep->base.sk)->hmac) {
1674 struct hash_desc desc;
1676 /* Sign the message. */
1677 sg_init_one(&sg, &cookie->c, bodysize);
1678 desc.tfm = sctp_sk(ep->base.sk)->hmac;
1681 if (crypto_hash_setkey(desc.tfm, ep->secret_key,
1682 sizeof(ep->secret_key)) ||
1683 crypto_hash_digest(&desc, &sg, bodysize, cookie->signature))
1696 /* Unpack the cookie from COOKIE ECHO chunk, recreating the association. */
1697 struct sctp_association *sctp_unpack_cookie(
1698 const struct sctp_endpoint *ep,
1699 const struct sctp_association *asoc,
1700 struct sctp_chunk *chunk, gfp_t gfp,
1701 int *error, struct sctp_chunk **errp)
1703 struct sctp_association *retval = NULL;
1704 struct sctp_signed_cookie *cookie;
1705 struct sctp_cookie *bear_cookie;
1706 int headersize, bodysize, fixed_size;
1707 __u8 *digest = ep->digest;
1708 struct scatterlist sg;
1711 struct sk_buff *skb = chunk->skb;
1713 struct hash_desc desc;
1715 /* Header size is static data prior to the actual cookie, including
1718 headersize = sizeof(sctp_chunkhdr_t) +
1719 (sizeof(struct sctp_signed_cookie) -
1720 sizeof(struct sctp_cookie));
1721 bodysize = ntohs(chunk->chunk_hdr->length) - headersize;
1722 fixed_size = headersize + sizeof(struct sctp_cookie);
1724 /* Verify that the chunk looks like it even has a cookie.
1725 * There must be enough room for our cookie and our peer's
1728 len = ntohs(chunk->chunk_hdr->length);
1729 if (len < fixed_size + sizeof(struct sctp_chunkhdr))
1732 /* Verify that the cookie has been padded out. */
1733 if (bodysize % SCTP_COOKIE_MULTIPLE)
1736 /* Process the cookie. */
1737 cookie = chunk->subh.cookie_hdr;
1738 bear_cookie = &cookie->c;
1740 if (!sctp_sk(ep->base.sk)->hmac)
1743 /* Check the signature. */
1744 sg_init_one(&sg, bear_cookie, bodysize);
1745 desc.tfm = sctp_sk(ep->base.sk)->hmac;
1748 memset(digest, 0x00, SCTP_SIGNATURE_SIZE);
1749 if (crypto_hash_setkey(desc.tfm, ep->secret_key,
1750 sizeof(ep->secret_key)) ||
1751 crypto_hash_digest(&desc, &sg, bodysize, digest)) {
1752 *error = -SCTP_IERROR_NOMEM;
1756 if (memcmp(digest, cookie->signature, SCTP_SIGNATURE_SIZE)) {
1757 *error = -SCTP_IERROR_BAD_SIG;
1762 /* IG Section 2.35.2:
1763 * 3) Compare the port numbers and the verification tag contained
1764 * within the COOKIE ECHO chunk to the actual port numbers and the
1765 * verification tag within the SCTP common header of the received
1766 * packet. If these values do not match the packet MUST be silently
1769 if (ntohl(chunk->sctp_hdr->vtag) != bear_cookie->my_vtag) {
1770 *error = -SCTP_IERROR_BAD_TAG;
1774 if (chunk->sctp_hdr->source != bear_cookie->peer_addr.v4.sin_port ||
1775 ntohs(chunk->sctp_hdr->dest) != bear_cookie->my_port) {
1776 *error = -SCTP_IERROR_BAD_PORTS;
1780 /* Check to see if the cookie is stale. If there is already
1781 * an association, there is no need to check cookie's expiration
1782 * for init collision case of lost COOKIE ACK.
1783 * If skb has been timestamped, then use the stamp, otherwise
1784 * use current time. This introduces a small possibility that
1785 * that a cookie may be considered expired, but his would only slow
1786 * down the new association establishment instead of every packet.
1788 if (sock_flag(ep->base.sk, SOCK_TIMESTAMP))
1789 kt = skb_get_ktime(skb);
1791 kt = ktime_get_real();
1793 if (!asoc && ktime_before(bear_cookie->expiration, kt)) {
1795 * Section 3.3.10.3 Stale Cookie Error (3)
1799 * Stale Cookie Error: Indicates the receipt of a valid State
1800 * Cookie that has expired.
1802 len = ntohs(chunk->chunk_hdr->length);
1803 *errp = sctp_make_op_error_space(asoc, chunk, len);
1805 suseconds_t usecs = ktime_to_us(ktime_sub(kt, bear_cookie->expiration));
1806 __be32 n = htonl(usecs);
1808 sctp_init_cause(*errp, SCTP_ERROR_STALE_COOKIE,
1810 sctp_addto_chunk(*errp, sizeof(n), &n);
1811 *error = -SCTP_IERROR_STALE_COOKIE;
1813 *error = -SCTP_IERROR_NOMEM;
1818 /* Make a new base association. */
1819 scope = sctp_scope(sctp_source(chunk));
1820 retval = sctp_association_new(ep, ep->base.sk, scope, gfp);
1822 *error = -SCTP_IERROR_NOMEM;
1826 /* Set up our peer's port number. */
1827 retval->peer.port = ntohs(chunk->sctp_hdr->source);
1829 /* Populate the association from the cookie. */
1830 memcpy(&retval->c, bear_cookie, sizeof(*bear_cookie));
1832 if (sctp_assoc_set_bind_addr_from_cookie(retval, bear_cookie,
1834 *error = -SCTP_IERROR_NOMEM;
1838 /* Also, add the destination address. */
1839 if (list_empty(&retval->base.bind_addr.address_list)) {
1840 sctp_add_bind_addr(&retval->base.bind_addr, &chunk->dest,
1841 SCTP_ADDR_SRC, GFP_ATOMIC);
1844 retval->next_tsn = retval->c.initial_tsn;
1845 retval->ctsn_ack_point = retval->next_tsn - 1;
1846 retval->addip_serial = retval->c.initial_tsn;
1847 retval->adv_peer_ack_point = retval->ctsn_ack_point;
1848 retval->peer.prsctp_capable = retval->c.prsctp_capable;
1849 retval->peer.adaptation_ind = retval->c.adaptation_ind;
1851 /* The INIT stuff will be done by the side effects. */
1856 sctp_association_free(retval);
1861 /* Yikes! The packet is either corrupt or deliberately
1864 *error = -SCTP_IERROR_MALFORMED;
1868 /********************************************************************
1869 * 3rd Level Abstractions
1870 ********************************************************************/
1872 struct __sctp_missing {
1878 * Report a missing mandatory parameter.
1880 static int sctp_process_missing_param(const struct sctp_association *asoc,
1881 sctp_param_t paramtype,
1882 struct sctp_chunk *chunk,
1883 struct sctp_chunk **errp)
1885 struct __sctp_missing report;
1888 len = WORD_ROUND(sizeof(report));
1890 /* Make an ERROR chunk, preparing enough room for
1891 * returning multiple unknown parameters.
1894 *errp = sctp_make_op_error_space(asoc, chunk, len);
1897 report.num_missing = htonl(1);
1898 report.type = paramtype;
1899 sctp_init_cause(*errp, SCTP_ERROR_MISS_PARAM,
1901 sctp_addto_chunk(*errp, sizeof(report), &report);
1904 /* Stop processing this chunk. */
1908 /* Report an Invalid Mandatory Parameter. */
1909 static int sctp_process_inv_mandatory(const struct sctp_association *asoc,
1910 struct sctp_chunk *chunk,
1911 struct sctp_chunk **errp)
1913 /* Invalid Mandatory Parameter Error has no payload. */
1916 *errp = sctp_make_op_error_space(asoc, chunk, 0);
1919 sctp_init_cause(*errp, SCTP_ERROR_INV_PARAM, 0);
1921 /* Stop processing this chunk. */
1925 static int sctp_process_inv_paramlength(const struct sctp_association *asoc,
1926 struct sctp_paramhdr *param,
1927 const struct sctp_chunk *chunk,
1928 struct sctp_chunk **errp)
1930 /* This is a fatal error. Any accumulated non-fatal errors are
1934 sctp_chunk_free(*errp);
1936 /* Create an error chunk and fill it in with our payload. */
1937 *errp = sctp_make_violation_paramlen(asoc, chunk, param);
1943 /* Do not attempt to handle the HOST_NAME parm. However, do
1944 * send back an indicator to the peer.
1946 static int sctp_process_hn_param(const struct sctp_association *asoc,
1947 union sctp_params param,
1948 struct sctp_chunk *chunk,
1949 struct sctp_chunk **errp)
1951 __u16 len = ntohs(param.p->length);
1953 /* Processing of the HOST_NAME parameter will generate an
1954 * ABORT. If we've accumulated any non-fatal errors, they
1955 * would be unrecognized parameters and we should not include
1956 * them in the ABORT.
1959 sctp_chunk_free(*errp);
1961 *errp = sctp_make_op_error_space(asoc, chunk, len);
1964 sctp_init_cause(*errp, SCTP_ERROR_DNS_FAILED, len);
1965 sctp_addto_chunk(*errp, len, param.v);
1968 /* Stop processing this chunk. */
1972 static int sctp_verify_ext_param(struct net *net, union sctp_params param)
1974 __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
1976 int have_asconf = 0;
1979 for (i = 0; i < num_ext; i++) {
1980 switch (param.ext->chunks[i]) {
1984 case SCTP_CID_ASCONF:
1985 case SCTP_CID_ASCONF_ACK:
1991 /* ADD-IP Security: The draft requires us to ABORT or ignore the
1992 * INIT/INIT-ACK if ADD-IP is listed, but AUTH is not. Do this
1993 * only if ADD-IP is turned on and we are not backward-compatible
1996 if (net->sctp.addip_noauth)
1999 if (net->sctp.addip_enable && !have_auth && have_asconf)
2005 static void sctp_process_ext_param(struct sctp_association *asoc,
2006 union sctp_params param)
2008 struct net *net = sock_net(asoc->base.sk);
2009 __u16 num_ext = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
2012 for (i = 0; i < num_ext; i++) {
2013 switch (param.ext->chunks[i]) {
2014 case SCTP_CID_FWD_TSN:
2015 if (net->sctp.prsctp_enable && !asoc->peer.prsctp_capable)
2016 asoc->peer.prsctp_capable = 1;
2019 /* if the peer reports AUTH, assume that he
2022 if (asoc->ep->auth_enable)
2023 asoc->peer.auth_capable = 1;
2025 case SCTP_CID_ASCONF:
2026 case SCTP_CID_ASCONF_ACK:
2027 if (net->sctp.addip_enable)
2028 asoc->peer.asconf_capable = 1;
2036 /* RFC 3.2.1 & the Implementers Guide 2.2.
2038 * The Parameter Types are encoded such that the
2039 * highest-order two bits specify the action that must be
2040 * taken if the processing endpoint does not recognize the
2043 * 00 - Stop processing this parameter; do not process any further
2044 * parameters within this chunk
2046 * 01 - Stop processing this parameter, do not process any further
2047 * parameters within this chunk, and report the unrecognized
2048 * parameter in an 'Unrecognized Parameter' ERROR chunk.
2050 * 10 - Skip this parameter and continue processing.
2052 * 11 - Skip this parameter and continue processing but
2053 * report the unrecognized parameter in an
2054 * 'Unrecognized Parameter' ERROR chunk.
2057 * SCTP_IERROR_NO_ERROR - continue with the chunk
2058 * SCTP_IERROR_ERROR - stop and report an error.
2059 * SCTP_IERROR_NOMEME - out of memory.
2061 static sctp_ierror_t sctp_process_unk_param(const struct sctp_association *asoc,
2062 union sctp_params param,
2063 struct sctp_chunk *chunk,
2064 struct sctp_chunk **errp)
2066 int retval = SCTP_IERROR_NO_ERROR;
2068 switch (param.p->type & SCTP_PARAM_ACTION_MASK) {
2069 case SCTP_PARAM_ACTION_DISCARD:
2070 retval = SCTP_IERROR_ERROR;
2072 case SCTP_PARAM_ACTION_SKIP:
2074 case SCTP_PARAM_ACTION_DISCARD_ERR:
2075 retval = SCTP_IERROR_ERROR;
2077 case SCTP_PARAM_ACTION_SKIP_ERR:
2078 /* Make an ERROR chunk, preparing enough room for
2079 * returning multiple unknown parameters.
2082 *errp = sctp_make_op_error_fixed(asoc, chunk);
2085 if (!sctp_init_cause_fixed(*errp, SCTP_ERROR_UNKNOWN_PARAM,
2086 WORD_ROUND(ntohs(param.p->length))))
2087 sctp_addto_chunk_fixed(*errp,
2088 WORD_ROUND(ntohs(param.p->length)),
2091 /* If there is no memory for generating the ERROR
2092 * report as specified, an ABORT will be triggered
2093 * to the peer and the association won't be
2096 retval = SCTP_IERROR_NOMEM;
2106 /* Verify variable length parameters
2108 * SCTP_IERROR_ABORT - trigger an ABORT
2109 * SCTP_IERROR_NOMEM - out of memory (abort)
2110 * SCTP_IERROR_ERROR - stop processing, trigger an ERROR
2111 * SCTP_IERROR_NO_ERROR - continue with the chunk
2113 static sctp_ierror_t sctp_verify_param(struct net *net,
2114 const struct sctp_endpoint *ep,
2115 const struct sctp_association *asoc,
2116 union sctp_params param,
2118 struct sctp_chunk *chunk,
2119 struct sctp_chunk **err_chunk)
2121 struct sctp_hmac_algo_param *hmacs;
2122 int retval = SCTP_IERROR_NO_ERROR;
2123 __u16 n_elt, id = 0;
2126 /* FIXME - This routine is not looking at each parameter per the
2127 * chunk type, i.e., unrecognized parameters should be further
2128 * identified based on the chunk id.
2131 switch (param.p->type) {
2132 case SCTP_PARAM_IPV4_ADDRESS:
2133 case SCTP_PARAM_IPV6_ADDRESS:
2134 case SCTP_PARAM_COOKIE_PRESERVATIVE:
2135 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
2136 case SCTP_PARAM_STATE_COOKIE:
2137 case SCTP_PARAM_HEARTBEAT_INFO:
2138 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
2139 case SCTP_PARAM_ECN_CAPABLE:
2140 case SCTP_PARAM_ADAPTATION_LAYER_IND:
2143 case SCTP_PARAM_SUPPORTED_EXT:
2144 if (!sctp_verify_ext_param(net, param))
2145 return SCTP_IERROR_ABORT;
2148 case SCTP_PARAM_SET_PRIMARY:
2149 if (!net->sctp.addip_enable)
2152 if (ntohs(param.p->length) < sizeof(struct sctp_addip_param) +
2153 sizeof(struct sctp_paramhdr)) {
2154 sctp_process_inv_paramlength(asoc, param.p,
2156 retval = SCTP_IERROR_ABORT;
2160 case SCTP_PARAM_HOST_NAME_ADDRESS:
2161 /* Tell the peer, we won't support this param. */
2162 sctp_process_hn_param(asoc, param, chunk, err_chunk);
2163 retval = SCTP_IERROR_ABORT;
2166 case SCTP_PARAM_FWD_TSN_SUPPORT:
2167 if (net->sctp.prsctp_enable)
2171 case SCTP_PARAM_RANDOM:
2172 if (!ep->auth_enable)
2175 /* SCTP-AUTH: Secion 6.1
2176 * If the random number is not 32 byte long the association
2177 * MUST be aborted. The ABORT chunk SHOULD contain the error
2178 * cause 'Protocol Violation'.
2180 if (SCTP_AUTH_RANDOM_LENGTH !=
2181 ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) {
2182 sctp_process_inv_paramlength(asoc, param.p,
2184 retval = SCTP_IERROR_ABORT;
2188 case SCTP_PARAM_CHUNKS:
2189 if (!ep->auth_enable)
2192 /* SCTP-AUTH: Section 3.2
2193 * The CHUNKS parameter MUST be included once in the INIT or
2194 * INIT-ACK chunk if the sender wants to receive authenticated
2195 * chunks. Its maximum length is 260 bytes.
2197 if (260 < ntohs(param.p->length)) {
2198 sctp_process_inv_paramlength(asoc, param.p,
2200 retval = SCTP_IERROR_ABORT;
2204 case SCTP_PARAM_HMAC_ALGO:
2205 if (!ep->auth_enable)
2208 hmacs = (struct sctp_hmac_algo_param *)param.p;
2209 n_elt = (ntohs(param.p->length) - sizeof(sctp_paramhdr_t)) >> 1;
2211 /* SCTP-AUTH: Section 6.1
2212 * The HMAC algorithm based on SHA-1 MUST be supported and
2213 * included in the HMAC-ALGO parameter.
2215 for (i = 0; i < n_elt; i++) {
2216 id = ntohs(hmacs->hmac_ids[i]);
2218 if (id == SCTP_AUTH_HMAC_ID_SHA1)
2222 if (id != SCTP_AUTH_HMAC_ID_SHA1) {
2223 sctp_process_inv_paramlength(asoc, param.p, chunk,
2225 retval = SCTP_IERROR_ABORT;
2230 pr_debug("%s: unrecognized param:%d for chunk:%d\n",
2231 __func__, ntohs(param.p->type), cid);
2233 retval = sctp_process_unk_param(asoc, param, chunk, err_chunk);
2239 /* Verify the INIT packet before we process it. */
2240 int sctp_verify_init(struct net *net, const struct sctp_endpoint *ep,
2241 const struct sctp_association *asoc, sctp_cid_t cid,
2242 sctp_init_chunk_t *peer_init, struct sctp_chunk *chunk,
2243 struct sctp_chunk **errp)
2245 union sctp_params param;
2246 bool has_cookie = false;
2249 /* Check for missing mandatory parameters. Note: Initial TSN is
2250 * also mandatory, but is not checked here since the valid range
2251 * is 0..2**32-1. RFC4960, section 3.3.3.
2253 if (peer_init->init_hdr.num_outbound_streams == 0 ||
2254 peer_init->init_hdr.num_inbound_streams == 0 ||
2255 peer_init->init_hdr.init_tag == 0 ||
2256 ntohl(peer_init->init_hdr.a_rwnd) < SCTP_DEFAULT_MINWINDOW)
2257 return sctp_process_inv_mandatory(asoc, chunk, errp);
2259 sctp_walk_params(param, peer_init, init_hdr.params) {
2260 if (param.p->type == SCTP_PARAM_STATE_COOKIE)
2264 /* There is a possibility that a parameter length was bad and
2265 * in that case we would have stoped walking the parameters.
2266 * The current param.p would point at the bad one.
2267 * Current consensus on the mailing list is to generate a PROTOCOL
2268 * VIOLATION error. We build the ERROR chunk here and let the normal
2269 * error handling code build and send the packet.
2271 if (param.v != (void *)chunk->chunk_end)
2272 return sctp_process_inv_paramlength(asoc, param.p, chunk, errp);
2274 /* The only missing mandatory param possible today is
2275 * the state cookie for an INIT-ACK chunk.
2277 if ((SCTP_CID_INIT_ACK == cid) && !has_cookie)
2278 return sctp_process_missing_param(asoc, SCTP_PARAM_STATE_COOKIE,
2281 /* Verify all the variable length parameters */
2282 sctp_walk_params(param, peer_init, init_hdr.params) {
2283 result = sctp_verify_param(net, ep, asoc, param, cid,
2286 case SCTP_IERROR_ABORT:
2287 case SCTP_IERROR_NOMEM:
2289 case SCTP_IERROR_ERROR:
2291 case SCTP_IERROR_NO_ERROR:
2296 } /* for (loop through all parameters) */
2301 /* Unpack the parameters in an INIT packet into an association.
2302 * Returns 0 on failure, else success.
2303 * FIXME: This is an association method.
2305 int sctp_process_init(struct sctp_association *asoc, struct sctp_chunk *chunk,
2306 const union sctp_addr *peer_addr,
2307 sctp_init_chunk_t *peer_init, gfp_t gfp)
2309 struct net *net = sock_net(asoc->base.sk);
2310 union sctp_params param;
2311 struct sctp_transport *transport;
2312 struct list_head *pos, *temp;
2314 union sctp_addr addr;
2318 /* We must include the address that the INIT packet came from.
2319 * This is the only address that matters for an INIT packet.
2320 * When processing a COOKIE ECHO, we retrieve the from address
2321 * of the INIT from the cookie.
2324 /* This implementation defaults to making the first transport
2325 * added as the primary transport. The source address seems to
2326 * be a a better choice than any of the embedded addresses.
2328 if (!sctp_assoc_add_peer(asoc, peer_addr, gfp, SCTP_ACTIVE))
2331 if (sctp_cmp_addr_exact(sctp_source(chunk), peer_addr))
2334 /* Process the initialization parameters. */
2335 sctp_walk_params(param, peer_init, init_hdr.params) {
2337 (param.p->type == SCTP_PARAM_IPV4_ADDRESS ||
2338 param.p->type == SCTP_PARAM_IPV6_ADDRESS)) {
2339 af = sctp_get_af_specific(param_type2af(param.p->type));
2340 if (!af->from_addr_param(&addr, param.addr,
2341 chunk->sctp_hdr->source, 0))
2343 if (sctp_cmp_addr_exact(sctp_source(chunk), &addr))
2347 if (!sctp_process_param(asoc, param, peer_addr, gfp))
2351 /* source address of chunk may not match any valid address */
2355 /* AUTH: After processing the parameters, make sure that we
2356 * have all the required info to potentially do authentications.
2358 if (asoc->peer.auth_capable && (!asoc->peer.peer_random ||
2359 !asoc->peer.peer_hmacs))
2360 asoc->peer.auth_capable = 0;
2362 /* In a non-backward compatible mode, if the peer claims
2363 * support for ADD-IP but not AUTH, the ADD-IP spec states
2364 * that we MUST ABORT the association. Section 6. The section
2365 * also give us an option to silently ignore the packet, which
2366 * is what we'll do here.
2368 if (!net->sctp.addip_noauth &&
2369 (asoc->peer.asconf_capable && !asoc->peer.auth_capable)) {
2370 asoc->peer.addip_disabled_mask |= (SCTP_PARAM_ADD_IP |
2372 SCTP_PARAM_SET_PRIMARY);
2373 asoc->peer.asconf_capable = 0;
2377 /* Walk list of transports, removing transports in the UNKNOWN state. */
2378 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
2379 transport = list_entry(pos, struct sctp_transport, transports);
2380 if (transport->state == SCTP_UNKNOWN) {
2381 sctp_assoc_rm_peer(asoc, transport);
2385 /* The fixed INIT headers are always in network byte
2388 asoc->peer.i.init_tag =
2389 ntohl(peer_init->init_hdr.init_tag);
2390 asoc->peer.i.a_rwnd =
2391 ntohl(peer_init->init_hdr.a_rwnd);
2392 asoc->peer.i.num_outbound_streams =
2393 ntohs(peer_init->init_hdr.num_outbound_streams);
2394 asoc->peer.i.num_inbound_streams =
2395 ntohs(peer_init->init_hdr.num_inbound_streams);
2396 asoc->peer.i.initial_tsn =
2397 ntohl(peer_init->init_hdr.initial_tsn);
2399 /* Apply the upper bounds for output streams based on peer's
2400 * number of inbound streams.
2402 if (asoc->c.sinit_num_ostreams >
2403 ntohs(peer_init->init_hdr.num_inbound_streams)) {
2404 asoc->c.sinit_num_ostreams =
2405 ntohs(peer_init->init_hdr.num_inbound_streams);
2408 if (asoc->c.sinit_max_instreams >
2409 ntohs(peer_init->init_hdr.num_outbound_streams)) {
2410 asoc->c.sinit_max_instreams =
2411 ntohs(peer_init->init_hdr.num_outbound_streams);
2414 /* Copy Initiation tag from INIT to VT_peer in cookie. */
2415 asoc->c.peer_vtag = asoc->peer.i.init_tag;
2417 /* Peer Rwnd : Current calculated value of the peer's rwnd. */
2418 asoc->peer.rwnd = asoc->peer.i.a_rwnd;
2420 /* Copy cookie in case we need to resend COOKIE-ECHO. */
2421 cookie = asoc->peer.cookie;
2423 asoc->peer.cookie = kmemdup(cookie, asoc->peer.cookie_len, gfp);
2424 if (!asoc->peer.cookie)
2428 /* RFC 2960 7.2.1 The initial value of ssthresh MAY be arbitrarily
2429 * high (for example, implementations MAY use the size of the receiver
2430 * advertised window).
2432 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
2434 transport->ssthresh = asoc->peer.i.a_rwnd;
2437 /* Set up the TSN tracking pieces. */
2438 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
2439 asoc->peer.i.initial_tsn, gfp))
2442 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
2444 * The stream sequence number in all the streams shall start
2445 * from 0 when the association is established. Also, when the
2446 * stream sequence number reaches the value 65535 the next
2447 * stream sequence number shall be set to 0.
2450 /* Allocate storage for the negotiated streams if it is not a temporary
2456 asoc->ssnmap = sctp_ssnmap_new(asoc->c.sinit_max_instreams,
2457 asoc->c.sinit_num_ostreams, gfp);
2461 error = sctp_assoc_set_id(asoc, gfp);
2466 /* ADDIP Section 4.1 ASCONF Chunk Procedures
2468 * When an endpoint has an ASCONF signaled change to be sent to the
2469 * remote endpoint it should do the following:
2471 * A2) A serial number should be assigned to the Chunk. The serial
2472 * number should be a monotonically increasing number. All serial
2473 * numbers are defined to be initialized at the start of the
2474 * association to the same value as the Initial TSN.
2476 asoc->peer.addip_serial = asoc->peer.i.initial_tsn - 1;
2480 /* Release the transport structures. */
2481 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
2482 transport = list_entry(pos, struct sctp_transport, transports);
2483 if (transport->state != SCTP_ACTIVE)
2484 sctp_assoc_rm_peer(asoc, transport);
2492 /* Update asoc with the option described in param.
2494 * RFC2960 3.3.2.1 Optional/Variable Length Parameters in INIT
2496 * asoc is the association to update.
2497 * param is the variable length parameter to use for update.
2498 * cid tells us if this is an INIT, INIT ACK or COOKIE ECHO.
2499 * If the current packet is an INIT we want to minimize the amount of
2500 * work we do. In particular, we should not build transport
2501 * structures for the addresses.
2503 static int sctp_process_param(struct sctp_association *asoc,
2504 union sctp_params param,
2505 const union sctp_addr *peer_addr,
2508 struct net *net = sock_net(asoc->base.sk);
2509 union sctp_addr addr;
2516 union sctp_addr_param *addr_param;
2517 struct sctp_transport *t;
2518 struct sctp_endpoint *ep = asoc->ep;
2520 /* We maintain all INIT parameters in network byte order all the
2521 * time. This allows us to not worry about whether the parameters
2522 * came from a fresh INIT, and INIT ACK, or were stored in a cookie.
2524 switch (param.p->type) {
2525 case SCTP_PARAM_IPV6_ADDRESS:
2526 if (PF_INET6 != asoc->base.sk->sk_family)
2530 case SCTP_PARAM_IPV4_ADDRESS:
2531 /* v4 addresses are not allowed on v6-only socket */
2532 if (ipv6_only_sock(asoc->base.sk))
2535 af = sctp_get_af_specific(param_type2af(param.p->type));
2536 if (!af->from_addr_param(&addr, param.addr, htons(asoc->peer.port), 0))
2538 scope = sctp_scope(peer_addr);
2539 if (sctp_in_scope(net, &addr, scope))
2540 if (!sctp_assoc_add_peer(asoc, &addr, gfp, SCTP_UNCONFIRMED))
2544 case SCTP_PARAM_COOKIE_PRESERVATIVE:
2545 if (!net->sctp.cookie_preserve_enable)
2548 stale = ntohl(param.life->lifespan_increment);
2550 /* Suggested Cookie Life span increment's unit is msec,
2553 asoc->cookie_life = ktime_add_ms(asoc->cookie_life, stale);
2556 case SCTP_PARAM_HOST_NAME_ADDRESS:
2557 pr_debug("%s: unimplemented SCTP_HOST_NAME_ADDRESS\n", __func__);
2560 case SCTP_PARAM_SUPPORTED_ADDRESS_TYPES:
2561 /* Turn off the default values first so we'll know which
2562 * ones are really set by the peer.
2564 asoc->peer.ipv4_address = 0;
2565 asoc->peer.ipv6_address = 0;
2567 /* Assume that peer supports the address family
2568 * by which it sends a packet.
2570 if (peer_addr->sa.sa_family == AF_INET6)
2571 asoc->peer.ipv6_address = 1;
2572 else if (peer_addr->sa.sa_family == AF_INET)
2573 asoc->peer.ipv4_address = 1;
2575 /* Cycle through address types; avoid divide by 0. */
2576 sat = ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
2578 sat /= sizeof(__u16);
2580 for (i = 0; i < sat; ++i) {
2581 switch (param.sat->types[i]) {
2582 case SCTP_PARAM_IPV4_ADDRESS:
2583 asoc->peer.ipv4_address = 1;
2586 case SCTP_PARAM_IPV6_ADDRESS:
2587 if (PF_INET6 == asoc->base.sk->sk_family)
2588 asoc->peer.ipv6_address = 1;
2591 case SCTP_PARAM_HOST_NAME_ADDRESS:
2592 asoc->peer.hostname_address = 1;
2595 default: /* Just ignore anything else. */
2601 case SCTP_PARAM_STATE_COOKIE:
2602 asoc->peer.cookie_len =
2603 ntohs(param.p->length) - sizeof(sctp_paramhdr_t);
2604 asoc->peer.cookie = param.cookie->body;
2607 case SCTP_PARAM_HEARTBEAT_INFO:
2608 /* Would be odd to receive, but it causes no problems. */
2611 case SCTP_PARAM_UNRECOGNIZED_PARAMETERS:
2612 /* Rejected during verify stage. */
2615 case SCTP_PARAM_ECN_CAPABLE:
2616 asoc->peer.ecn_capable = 1;
2619 case SCTP_PARAM_ADAPTATION_LAYER_IND:
2620 asoc->peer.adaptation_ind = ntohl(param.aind->adaptation_ind);
2623 case SCTP_PARAM_SET_PRIMARY:
2624 if (!net->sctp.addip_enable)
2627 addr_param = param.v + sizeof(sctp_addip_param_t);
2629 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
2633 if (!af->from_addr_param(&addr, addr_param,
2634 htons(asoc->peer.port), 0))
2637 if (!af->addr_valid(&addr, NULL, NULL))
2640 t = sctp_assoc_lookup_paddr(asoc, &addr);
2644 sctp_assoc_set_primary(asoc, t);
2647 case SCTP_PARAM_SUPPORTED_EXT:
2648 sctp_process_ext_param(asoc, param);
2651 case SCTP_PARAM_FWD_TSN_SUPPORT:
2652 if (net->sctp.prsctp_enable) {
2653 asoc->peer.prsctp_capable = 1;
2659 case SCTP_PARAM_RANDOM:
2660 if (!ep->auth_enable)
2663 /* Save peer's random parameter */
2664 asoc->peer.peer_random = kmemdup(param.p,
2665 ntohs(param.p->length), gfp);
2666 if (!asoc->peer.peer_random) {
2672 case SCTP_PARAM_HMAC_ALGO:
2673 if (!ep->auth_enable)
2676 /* Save peer's HMAC list */
2677 asoc->peer.peer_hmacs = kmemdup(param.p,
2678 ntohs(param.p->length), gfp);
2679 if (!asoc->peer.peer_hmacs) {
2684 /* Set the default HMAC the peer requested*/
2685 sctp_auth_asoc_set_default_hmac(asoc, param.hmac_algo);
2688 case SCTP_PARAM_CHUNKS:
2689 if (!ep->auth_enable)
2692 asoc->peer.peer_chunks = kmemdup(param.p,
2693 ntohs(param.p->length), gfp);
2694 if (!asoc->peer.peer_chunks)
2699 /* Any unrecognized parameters should have been caught
2700 * and handled by sctp_verify_param() which should be
2701 * called prior to this routine. Simply log the error
2704 pr_debug("%s: ignoring param:%d for association:%p.\n",
2705 __func__, ntohs(param.p->type), asoc);
2712 /* Select a new verification tag. */
2713 __u32 sctp_generate_tag(const struct sctp_endpoint *ep)
2715 /* I believe that this random number generator complies with RFC1750.
2716 * A tag of 0 is reserved for special cases (e.g. INIT).
2721 get_random_bytes(&x, sizeof(__u32));
2727 /* Select an initial TSN to send during startup. */
2728 __u32 sctp_generate_tsn(const struct sctp_endpoint *ep)
2732 get_random_bytes(&retval, sizeof(__u32));
2737 * ADDIP 3.1.1 Address Configuration Change Chunk (ASCONF)
2739 * 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
2740 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2741 * | Type = 0xC1 | Chunk Flags | Chunk Length |
2742 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2744 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2745 * | Address Parameter |
2746 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2747 * | ASCONF Parameter #1 |
2748 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2752 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2753 * | ASCONF Parameter #N |
2754 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2756 * Address Parameter and other parameter will not be wrapped in this function
2758 static struct sctp_chunk *sctp_make_asconf(struct sctp_association *asoc,
2759 union sctp_addr *addr,
2762 sctp_addiphdr_t asconf;
2763 struct sctp_chunk *retval;
2764 int length = sizeof(asconf) + vparam_len;
2765 union sctp_addr_param addrparam;
2767 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
2769 addrlen = af->to_addr_param(addr, &addrparam);
2774 /* Create the chunk. */
2775 retval = sctp_make_control(asoc, SCTP_CID_ASCONF, 0, length);
2779 asconf.serial = htonl(asoc->addip_serial++);
2781 retval->subh.addip_hdr =
2782 sctp_addto_chunk(retval, sizeof(asconf), &asconf);
2783 retval->param_hdr.v =
2784 sctp_addto_chunk(retval, addrlen, &addrparam);
2790 * 3.2.1 Add IP Address
2792 * 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
2793 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2794 * | Type = 0xC001 | Length = Variable |
2795 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2796 * | ASCONF-Request Correlation ID |
2797 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2798 * | Address Parameter |
2799 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2801 * 3.2.2 Delete IP Address
2803 * 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
2804 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2805 * | Type = 0xC002 | Length = Variable |
2806 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2807 * | ASCONF-Request Correlation ID |
2808 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2809 * | Address Parameter |
2810 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2813 struct sctp_chunk *sctp_make_asconf_update_ip(struct sctp_association *asoc,
2814 union sctp_addr *laddr,
2815 struct sockaddr *addrs,
2819 sctp_addip_param_t param;
2820 struct sctp_chunk *retval;
2821 union sctp_addr_param addr_param;
2822 union sctp_addr *addr;
2825 int paramlen = sizeof(param);
2826 int addr_param_len = 0;
2831 /* Get total length of all the address parameters. */
2833 for (i = 0; i < addrcnt; i++) {
2835 af = sctp_get_af_specific(addr->v4.sin_family);
2836 addr_param_len = af->to_addr_param(addr, &addr_param);
2838 totallen += paramlen;
2839 totallen += addr_param_len;
2841 addr_buf += af->sockaddr_len;
2842 if (asoc->asconf_addr_del_pending && !del_pickup) {
2843 /* reuse the parameter length from the same scope one */
2844 totallen += paramlen;
2845 totallen += addr_param_len;
2848 pr_debug("%s: picked same-scope del_pending addr, "
2849 "totallen for all addresses is %d\n",
2850 __func__, totallen);
2854 /* Create an asconf chunk with the required length. */
2855 retval = sctp_make_asconf(asoc, laddr, totallen);
2859 /* Add the address parameters to the asconf chunk. */
2861 for (i = 0; i < addrcnt; i++) {
2863 af = sctp_get_af_specific(addr->v4.sin_family);
2864 addr_param_len = af->to_addr_param(addr, &addr_param);
2865 param.param_hdr.type = flags;
2866 param.param_hdr.length = htons(paramlen + addr_param_len);
2869 sctp_addto_chunk(retval, paramlen, ¶m);
2870 sctp_addto_chunk(retval, addr_param_len, &addr_param);
2872 addr_buf += af->sockaddr_len;
2874 if (flags == SCTP_PARAM_ADD_IP && del_pickup) {
2875 addr = asoc->asconf_addr_del_pending;
2876 af = sctp_get_af_specific(addr->v4.sin_family);
2877 addr_param_len = af->to_addr_param(addr, &addr_param);
2878 param.param_hdr.type = SCTP_PARAM_DEL_IP;
2879 param.param_hdr.length = htons(paramlen + addr_param_len);
2882 sctp_addto_chunk(retval, paramlen, ¶m);
2883 sctp_addto_chunk(retval, addr_param_len, &addr_param);
2889 * 3.2.4 Set Primary IP Address
2891 * 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
2892 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2893 * | Type =0xC004 | Length = Variable |
2894 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2895 * | ASCONF-Request Correlation ID |
2896 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2897 * | Address Parameter |
2898 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2900 * Create an ASCONF chunk with Set Primary IP address parameter.
2902 struct sctp_chunk *sctp_make_asconf_set_prim(struct sctp_association *asoc,
2903 union sctp_addr *addr)
2905 sctp_addip_param_t param;
2906 struct sctp_chunk *retval;
2907 int len = sizeof(param);
2908 union sctp_addr_param addrparam;
2910 struct sctp_af *af = sctp_get_af_specific(addr->v4.sin_family);
2912 addrlen = af->to_addr_param(addr, &addrparam);
2917 /* Create the chunk and make asconf header. */
2918 retval = sctp_make_asconf(asoc, addr, len);
2922 param.param_hdr.type = SCTP_PARAM_SET_PRIMARY;
2923 param.param_hdr.length = htons(len);
2926 sctp_addto_chunk(retval, sizeof(param), ¶m);
2927 sctp_addto_chunk(retval, addrlen, &addrparam);
2932 /* ADDIP 3.1.2 Address Configuration Acknowledgement Chunk (ASCONF-ACK)
2934 * 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
2935 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2936 * | Type = 0x80 | Chunk Flags | Chunk Length |
2937 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2939 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2940 * | ASCONF Parameter Response#1 |
2941 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2945 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2946 * | ASCONF Parameter Response#N |
2947 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2949 * Create an ASCONF_ACK chunk with enough space for the parameter responses.
2951 static struct sctp_chunk *sctp_make_asconf_ack(const struct sctp_association *asoc,
2952 __u32 serial, int vparam_len)
2954 sctp_addiphdr_t asconf;
2955 struct sctp_chunk *retval;
2956 int length = sizeof(asconf) + vparam_len;
2958 /* Create the chunk. */
2959 retval = sctp_make_control(asoc, SCTP_CID_ASCONF_ACK, 0, length);
2963 asconf.serial = htonl(serial);
2965 retval->subh.addip_hdr =
2966 sctp_addto_chunk(retval, sizeof(asconf), &asconf);
2971 /* Add response parameters to an ASCONF_ACK chunk. */
2972 static void sctp_add_asconf_response(struct sctp_chunk *chunk, __be32 crr_id,
2973 __be16 err_code, sctp_addip_param_t *asconf_param)
2975 sctp_addip_param_t ack_param;
2976 sctp_errhdr_t err_param;
2977 int asconf_param_len = 0;
2978 int err_param_len = 0;
2979 __be16 response_type;
2981 if (SCTP_ERROR_NO_ERROR == err_code) {
2982 response_type = SCTP_PARAM_SUCCESS_REPORT;
2984 response_type = SCTP_PARAM_ERR_CAUSE;
2985 err_param_len = sizeof(err_param);
2988 ntohs(asconf_param->param_hdr.length);
2991 /* Add Success Indication or Error Cause Indication parameter. */
2992 ack_param.param_hdr.type = response_type;
2993 ack_param.param_hdr.length = htons(sizeof(ack_param) +
2996 ack_param.crr_id = crr_id;
2997 sctp_addto_chunk(chunk, sizeof(ack_param), &ack_param);
2999 if (SCTP_ERROR_NO_ERROR == err_code)
3002 /* Add Error Cause parameter. */
3003 err_param.cause = err_code;
3004 err_param.length = htons(err_param_len + asconf_param_len);
3005 sctp_addto_chunk(chunk, err_param_len, &err_param);
3007 /* Add the failed TLV copied from ASCONF chunk. */
3009 sctp_addto_chunk(chunk, asconf_param_len, asconf_param);
3012 /* Process a asconf parameter. */
3013 static __be16 sctp_process_asconf_param(struct sctp_association *asoc,
3014 struct sctp_chunk *asconf,
3015 sctp_addip_param_t *asconf_param)
3017 struct sctp_transport *peer;
3019 union sctp_addr addr;
3020 union sctp_addr_param *addr_param;
3022 addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t);
3024 if (asconf_param->param_hdr.type != SCTP_PARAM_ADD_IP &&
3025 asconf_param->param_hdr.type != SCTP_PARAM_DEL_IP &&
3026 asconf_param->param_hdr.type != SCTP_PARAM_SET_PRIMARY)
3027 return SCTP_ERROR_UNKNOWN_PARAM;
3029 switch (addr_param->p.type) {
3030 case SCTP_PARAM_IPV6_ADDRESS:
3031 if (!asoc->peer.ipv6_address)
3032 return SCTP_ERROR_DNS_FAILED;
3034 case SCTP_PARAM_IPV4_ADDRESS:
3035 if (!asoc->peer.ipv4_address)
3036 return SCTP_ERROR_DNS_FAILED;
3039 return SCTP_ERROR_DNS_FAILED;
3042 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
3044 return SCTP_ERROR_DNS_FAILED;
3046 if (!af->from_addr_param(&addr, addr_param, htons(asoc->peer.port), 0))
3047 return SCTP_ERROR_DNS_FAILED;
3049 /* ADDIP 4.2.1 This parameter MUST NOT contain a broadcast
3050 * or multicast address.
3051 * (note: wildcard is permitted and requires special handling so
3052 * make sure we check for that)
3054 if (!af->is_any(&addr) && !af->addr_valid(&addr, NULL, asconf->skb))
3055 return SCTP_ERROR_DNS_FAILED;
3057 switch (asconf_param->param_hdr.type) {
3058 case SCTP_PARAM_ADD_IP:
3060 * If the address 0.0.0.0 or ::0 is provided, the source
3061 * address of the packet MUST be added.
3063 if (af->is_any(&addr))
3064 memcpy(&addr, &asconf->source, sizeof(addr));
3066 /* ADDIP 4.3 D9) If an endpoint receives an ADD IP address
3067 * request and does not have the local resources to add this
3068 * new address to the association, it MUST return an Error
3069 * Cause TLV set to the new error code 'Operation Refused
3070 * Due to Resource Shortage'.
3073 peer = sctp_assoc_add_peer(asoc, &addr, GFP_ATOMIC, SCTP_UNCONFIRMED);
3075 return SCTP_ERROR_RSRC_LOW;
3077 /* Start the heartbeat timer. */
3078 if (!mod_timer(&peer->hb_timer, sctp_transport_timeout(peer)))
3079 sctp_transport_hold(peer);
3080 asoc->new_transport = peer;
3082 case SCTP_PARAM_DEL_IP:
3083 /* ADDIP 4.3 D7) If a request is received to delete the
3084 * last remaining IP address of a peer endpoint, the receiver
3085 * MUST send an Error Cause TLV with the error cause set to the
3086 * new error code 'Request to Delete Last Remaining IP Address'.
3088 if (asoc->peer.transport_count == 1)
3089 return SCTP_ERROR_DEL_LAST_IP;
3091 /* ADDIP 4.3 D8) If a request is received to delete an IP
3092 * address which is also the source address of the IP packet
3093 * which contained the ASCONF chunk, the receiver MUST reject
3094 * this request. To reject the request the receiver MUST send
3095 * an Error Cause TLV set to the new error code 'Request to
3096 * Delete Source IP Address'
3098 if (sctp_cmp_addr_exact(&asconf->source, &addr))
3099 return SCTP_ERROR_DEL_SRC_IP;
3102 * If the address 0.0.0.0 or ::0 is provided, all
3103 * addresses of the peer except the source address of the
3104 * packet MUST be deleted.
3106 if (af->is_any(&addr)) {
3107 sctp_assoc_set_primary(asoc, asconf->transport);
3108 sctp_assoc_del_nonprimary_peers(asoc,
3110 return SCTP_ERROR_NO_ERROR;
3113 /* If the address is not part of the association, the
3114 * ASCONF-ACK with Error Cause Indication Parameter
3115 * which including cause of Unresolvable Address should
3118 peer = sctp_assoc_lookup_paddr(asoc, &addr);
3120 return SCTP_ERROR_DNS_FAILED;
3122 sctp_assoc_rm_peer(asoc, peer);
3124 case SCTP_PARAM_SET_PRIMARY:
3125 /* ADDIP Section 4.2.4
3126 * If the address 0.0.0.0 or ::0 is provided, the receiver
3127 * MAY mark the source address of the packet as its
3130 if (af->is_any(&addr))
3131 memcpy(&addr, sctp_source(asconf), sizeof(addr));
3133 peer = sctp_assoc_lookup_paddr(asoc, &addr);
3135 return SCTP_ERROR_DNS_FAILED;
3137 sctp_assoc_set_primary(asoc, peer);
3141 return SCTP_ERROR_NO_ERROR;
3144 /* Verify the ASCONF packet before we process it. */
3145 bool sctp_verify_asconf(const struct sctp_association *asoc,
3146 struct sctp_chunk *chunk, bool addr_param_needed,
3147 struct sctp_paramhdr **errp)
3149 sctp_addip_chunk_t *addip = (sctp_addip_chunk_t *) chunk->chunk_hdr;
3150 union sctp_params param;
3151 bool addr_param_seen = false;
3153 sctp_walk_params(param, addip, addip_hdr.params) {
3154 size_t length = ntohs(param.p->length);
3157 switch (param.p->type) {
3158 case SCTP_PARAM_ERR_CAUSE:
3160 case SCTP_PARAM_IPV4_ADDRESS:
3161 if (length != sizeof(sctp_ipv4addr_param_t))
3163 /* ensure there is only one addr param and it's in the
3164 * beginning of addip_hdr params, or we reject it.
3166 if (param.v != addip->addip_hdr.params)
3168 addr_param_seen = true;
3170 case SCTP_PARAM_IPV6_ADDRESS:
3171 if (length != sizeof(sctp_ipv6addr_param_t))
3173 if (param.v != addip->addip_hdr.params)
3175 addr_param_seen = true;
3177 case SCTP_PARAM_ADD_IP:
3178 case SCTP_PARAM_DEL_IP:
3179 case SCTP_PARAM_SET_PRIMARY:
3180 /* In ASCONF chunks, these need to be first. */
3181 if (addr_param_needed && !addr_param_seen)
3183 length = ntohs(param.addip->param_hdr.length);
3184 if (length < sizeof(sctp_addip_param_t) +
3185 sizeof(sctp_paramhdr_t))
3188 case SCTP_PARAM_SUCCESS_REPORT:
3189 case SCTP_PARAM_ADAPTATION_LAYER_IND:
3190 if (length != sizeof(sctp_addip_param_t))
3194 /* This is unkown to us, reject! */
3199 /* Remaining sanity checks. */
3200 if (addr_param_needed && !addr_param_seen)
3202 if (!addr_param_needed && addr_param_seen)
3204 if (param.v != chunk->chunk_end)
3210 /* Process an incoming ASCONF chunk with the next expected serial no. and
3211 * return an ASCONF_ACK chunk to be sent in response.
3213 struct sctp_chunk *sctp_process_asconf(struct sctp_association *asoc,
3214 struct sctp_chunk *asconf)
3216 sctp_addip_chunk_t *addip = (sctp_addip_chunk_t *) asconf->chunk_hdr;
3217 bool all_param_pass = true;
3218 union sctp_params param;
3219 sctp_addiphdr_t *hdr;
3220 union sctp_addr_param *addr_param;
3221 sctp_addip_param_t *asconf_param;
3222 struct sctp_chunk *asconf_ack;
3228 chunk_len = ntohs(asconf->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
3229 hdr = (sctp_addiphdr_t *)asconf->skb->data;
3230 serial = ntohl(hdr->serial);
3232 /* Skip the addiphdr and store a pointer to address parameter. */
3233 length = sizeof(sctp_addiphdr_t);
3234 addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
3235 chunk_len -= length;
3237 /* Skip the address parameter and store a pointer to the first
3240 length = ntohs(addr_param->p.length);
3241 asconf_param = (void *)addr_param + length;
3242 chunk_len -= length;
3244 /* create an ASCONF_ACK chunk.
3245 * Based on the definitions of parameters, we know that the size of
3246 * ASCONF_ACK parameters are less than or equal to the fourfold of ASCONF
3249 asconf_ack = sctp_make_asconf_ack(asoc, serial, chunk_len * 4);
3253 /* Process the TLVs contained within the ASCONF chunk. */
3254 sctp_walk_params(param, addip, addip_hdr.params) {
3255 /* Skip preceeding address parameters. */
3256 if (param.p->type == SCTP_PARAM_IPV4_ADDRESS ||
3257 param.p->type == SCTP_PARAM_IPV6_ADDRESS)
3260 err_code = sctp_process_asconf_param(asoc, asconf,
3263 * If an error response is received for a TLV parameter,
3264 * all TLVs with no response before the failed TLV are
3265 * considered successful if not reported. All TLVs after
3266 * the failed response are considered unsuccessful unless
3267 * a specific success indication is present for the parameter.
3269 if (err_code != SCTP_ERROR_NO_ERROR)
3270 all_param_pass = false;
3271 if (!all_param_pass)
3272 sctp_add_asconf_response(asconf_ack, param.addip->crr_id,
3273 err_code, param.addip);
3275 /* ADDIP 4.3 D11) When an endpoint receiving an ASCONF to add
3276 * an IP address sends an 'Out of Resource' in its response, it
3277 * MUST also fail any subsequent add or delete requests bundled
3280 if (err_code == SCTP_ERROR_RSRC_LOW)
3284 asoc->peer.addip_serial++;
3286 /* If we are sending a new ASCONF_ACK hold a reference to it in assoc
3287 * after freeing the reference to old asconf ack if any.
3290 sctp_chunk_hold(asconf_ack);
3291 list_add_tail(&asconf_ack->transmitted_list,
3292 &asoc->asconf_ack_list);
3298 /* Process a asconf parameter that is successfully acked. */
3299 static void sctp_asconf_param_success(struct sctp_association *asoc,
3300 sctp_addip_param_t *asconf_param)
3303 union sctp_addr addr;
3304 struct sctp_bind_addr *bp = &asoc->base.bind_addr;
3305 union sctp_addr_param *addr_param;
3306 struct sctp_transport *transport;
3307 struct sctp_sockaddr_entry *saddr;
3309 addr_param = (void *)asconf_param + sizeof(sctp_addip_param_t);
3311 /* We have checked the packet before, so we do not check again. */
3312 af = sctp_get_af_specific(param_type2af(addr_param->p.type));
3313 if (!af->from_addr_param(&addr, addr_param, htons(bp->port), 0))
3316 switch (asconf_param->param_hdr.type) {
3317 case SCTP_PARAM_ADD_IP:
3318 /* This is always done in BH context with a socket lock
3319 * held, so the list can not change.
3322 list_for_each_entry(saddr, &bp->address_list, list) {
3323 if (sctp_cmp_addr_exact(&saddr->a, &addr))
3324 saddr->state = SCTP_ADDR_SRC;
3327 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
3329 dst_release(transport->dst);
3330 transport->dst = NULL;
3333 case SCTP_PARAM_DEL_IP:
3335 sctp_del_bind_addr(bp, &addr);
3336 if (asoc->asconf_addr_del_pending != NULL &&
3337 sctp_cmp_addr_exact(asoc->asconf_addr_del_pending, &addr)) {
3338 kfree(asoc->asconf_addr_del_pending);
3339 asoc->asconf_addr_del_pending = NULL;
3342 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
3344 dst_release(transport->dst);
3345 transport->dst = NULL;
3353 /* Get the corresponding ASCONF response error code from the ASCONF_ACK chunk
3354 * for the given asconf parameter. If there is no response for this parameter,
3355 * return the error code based on the third argument 'no_err'.
3357 * A7) If an error response is received for a TLV parameter, all TLVs with no
3358 * response before the failed TLV are considered successful if not reported.
3359 * All TLVs after the failed response are considered unsuccessful unless a
3360 * specific success indication is present for the parameter.
3362 static __be16 sctp_get_asconf_response(struct sctp_chunk *asconf_ack,
3363 sctp_addip_param_t *asconf_param,
3366 sctp_addip_param_t *asconf_ack_param;
3367 sctp_errhdr_t *err_param;
3373 err_code = SCTP_ERROR_NO_ERROR;
3375 err_code = SCTP_ERROR_REQ_REFUSED;
3377 asconf_ack_len = ntohs(asconf_ack->chunk_hdr->length) -
3378 sizeof(sctp_chunkhdr_t);
3380 /* Skip the addiphdr from the asconf_ack chunk and store a pointer to
3381 * the first asconf_ack parameter.
3383 length = sizeof(sctp_addiphdr_t);
3384 asconf_ack_param = (sctp_addip_param_t *)(asconf_ack->skb->data +
3386 asconf_ack_len -= length;
3388 while (asconf_ack_len > 0) {
3389 if (asconf_ack_param->crr_id == asconf_param->crr_id) {
3390 switch (asconf_ack_param->param_hdr.type) {
3391 case SCTP_PARAM_SUCCESS_REPORT:
3392 return SCTP_ERROR_NO_ERROR;
3393 case SCTP_PARAM_ERR_CAUSE:
3394 length = sizeof(sctp_addip_param_t);
3395 err_param = (void *)asconf_ack_param + length;
3396 asconf_ack_len -= length;
3397 if (asconf_ack_len > 0)
3398 return err_param->cause;
3400 return SCTP_ERROR_INV_PARAM;
3403 return SCTP_ERROR_INV_PARAM;
3407 length = ntohs(asconf_ack_param->param_hdr.length);
3408 asconf_ack_param = (void *)asconf_ack_param + length;
3409 asconf_ack_len -= length;
3415 /* Process an incoming ASCONF_ACK chunk against the cached last ASCONF chunk. */
3416 int sctp_process_asconf_ack(struct sctp_association *asoc,
3417 struct sctp_chunk *asconf_ack)
3419 struct sctp_chunk *asconf = asoc->addip_last_asconf;
3420 union sctp_addr_param *addr_param;
3421 sctp_addip_param_t *asconf_param;
3423 int asconf_len = asconf->skb->len;
3424 int all_param_pass = 0;
3427 __be16 err_code = SCTP_ERROR_NO_ERROR;
3429 /* Skip the chunkhdr and addiphdr from the last asconf sent and store
3430 * a pointer to address parameter.
3432 length = sizeof(sctp_addip_chunk_t);
3433 addr_param = (union sctp_addr_param *)(asconf->skb->data + length);
3434 asconf_len -= length;
3436 /* Skip the address parameter in the last asconf sent and store a
3437 * pointer to the first asconf parameter.
3439 length = ntohs(addr_param->p.length);
3440 asconf_param = (void *)addr_param + length;
3441 asconf_len -= length;
3444 * A8) If there is no response(s) to specific TLV parameter(s), and no
3445 * failures are indicated, then all request(s) are considered
3448 if (asconf_ack->skb->len == sizeof(sctp_addiphdr_t))
3451 /* Process the TLVs contained in the last sent ASCONF chunk. */
3452 while (asconf_len > 0) {
3454 err_code = SCTP_ERROR_NO_ERROR;
3456 err_code = sctp_get_asconf_response(asconf_ack,
3459 if (no_err && (SCTP_ERROR_NO_ERROR != err_code))
3464 case SCTP_ERROR_NO_ERROR:
3465 sctp_asconf_param_success(asoc, asconf_param);
3468 case SCTP_ERROR_RSRC_LOW:
3472 case SCTP_ERROR_UNKNOWN_PARAM:
3473 /* Disable sending this type of asconf parameter in
3476 asoc->peer.addip_disabled_mask |=
3477 asconf_param->param_hdr.type;
3480 case SCTP_ERROR_REQ_REFUSED:
3481 case SCTP_ERROR_DEL_LAST_IP:
3482 case SCTP_ERROR_DEL_SRC_IP:
3487 /* Skip the processed asconf parameter and move to the next
3490 length = ntohs(asconf_param->param_hdr.length);
3491 asconf_param = (void *)asconf_param + length;
3492 asconf_len -= length;
3495 if (no_err && asoc->src_out_of_asoc_ok) {
3496 asoc->src_out_of_asoc_ok = 0;
3497 sctp_transport_immediate_rtx(asoc->peer.primary_path);
3500 /* Free the cached last sent asconf chunk. */
3501 list_del_init(&asconf->transmitted_list);
3502 sctp_chunk_free(asconf);
3503 asoc->addip_last_asconf = NULL;
3508 /* Make a FWD TSN chunk. */
3509 struct sctp_chunk *sctp_make_fwdtsn(const struct sctp_association *asoc,
3510 __u32 new_cum_tsn, size_t nstreams,
3511 struct sctp_fwdtsn_skip *skiplist)
3513 struct sctp_chunk *retval = NULL;
3514 struct sctp_fwdtsn_hdr ftsn_hdr;
3515 struct sctp_fwdtsn_skip skip;
3519 hint = (nstreams + 1) * sizeof(__u32);
3521 retval = sctp_make_control(asoc, SCTP_CID_FWD_TSN, 0, hint);
3526 ftsn_hdr.new_cum_tsn = htonl(new_cum_tsn);
3527 retval->subh.fwdtsn_hdr =
3528 sctp_addto_chunk(retval, sizeof(ftsn_hdr), &ftsn_hdr);
3530 for (i = 0; i < nstreams; i++) {
3531 skip.stream = skiplist[i].stream;
3532 skip.ssn = skiplist[i].ssn;
3533 sctp_addto_chunk(retval, sizeof(skip), &skip);