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Vlad Yasevich60c778b2008-01-11 09:57:09 -05001/* SCTP kernel implementation
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999-2000 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 * Copyright (c) 2001 Intel Corp.
6 * Copyright (c) 2001 La Monte H.P. Yarroll
7 *
Vlad Yasevich60c778b2008-01-11 09:57:09 -05008 * This file is part of the SCTP kernel implementation
Linus Torvalds1da177e2005-04-16 15:20:36 -07009 *
10 * This module provides the abstraction for an SCTP association.
11 *
Vlad Yasevich60c778b2008-01-11 09:57:09 -050012 * This SCTP implementation is free software;
Linus Torvalds1da177e2005-04-16 15:20:36 -070013 * you can redistribute it and/or modify it under the terms of
14 * the GNU General Public License as published by
15 * the Free Software Foundation; either version 2, or (at your option)
16 * any later version.
17 *
Vlad Yasevich60c778b2008-01-11 09:57:09 -050018 * This SCTP implementation is distributed in the hope that it
Linus Torvalds1da177e2005-04-16 15:20:36 -070019 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
20 * ************************
21 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
22 * See the GNU General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License
25 * along with GNU CC; see the file COPYING. If not, write to
26 * the Free Software Foundation, 59 Temple Place - Suite 330,
27 * Boston, MA 02111-1307, USA.
28 *
29 * Please send any bug reports or fixes you make to the
30 * email address(es):
31 * lksctp developers <lksctp-developers@lists.sourceforge.net>
32 *
33 * Or submit a bug report through the following website:
34 * http://www.sf.net/projects/lksctp
35 *
36 * Written or modified by:
37 * La Monte H.P. Yarroll <piggy@acm.org>
38 * Karl Knutson <karl@athena.chicago.il.us>
39 * Jon Grimm <jgrimm@us.ibm.com>
40 * Xingang Guo <xingang.guo@intel.com>
41 * Hui Huang <hui.huang@nokia.com>
42 * Sridhar Samudrala <sri@us.ibm.com>
43 * Daisy Chang <daisyc@us.ibm.com>
44 * Ryan Layer <rmlayer@us.ibm.com>
45 * Kevin Gao <kevin.gao@intel.com>
46 *
47 * Any bugs reported given to us we will try to fix... any fixes shared will
48 * be incorporated into the next SCTP release.
49 */
50
51#include <linux/types.h>
52#include <linux/fcntl.h>
53#include <linux/poll.h>
54#include <linux/init.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070055
56#include <linux/slab.h>
57#include <linux/in.h>
58#include <net/ipv6.h>
59#include <net/sctp/sctp.h>
60#include <net/sctp/sm.h>
61
62/* Forward declarations for internal functions. */
David Howellsc4028952006-11-22 14:57:56 +000063static void sctp_assoc_bh_rcv(struct work_struct *work);
Vlad Yasevicha08de642007-12-20 14:11:47 -080064static void sctp_assoc_free_asconf_acks(struct sctp_association *asoc);
Linus Torvalds1da177e2005-04-16 15:20:36 -070065
66
67/* 1st Level Abstractions. */
68
69/* Initialize a new association from provided memory. */
70static struct sctp_association *sctp_association_init(struct sctp_association *asoc,
71 const struct sctp_endpoint *ep,
72 const struct sock *sk,
73 sctp_scope_t scope,
Al Virodd0fc662005-10-07 07:46:04 +010074 gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -070075{
76 struct sctp_sock *sp;
77 int i;
Vlad Yasevicha29a5bd2007-09-16 19:31:35 -070078 sctp_paramhdr_t *p;
79 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -070080
81 /* Retrieve the SCTP per socket area. */
82 sp = sctp_sk((struct sock *)sk);
83
84 /* Init all variables to a known value. */
85 memset(asoc, 0, sizeof(struct sctp_association));
86
87 /* Discarding const is appropriate here. */
88 asoc->ep = (struct sctp_endpoint *)ep;
89 sctp_endpoint_hold(asoc->ep);
90
91 /* Hold the sock. */
92 asoc->base.sk = (struct sock *)sk;
93 sock_hold(asoc->base.sk);
94
95 /* Initialize the common base substructure. */
96 asoc->base.type = SCTP_EP_TYPE_ASSOCIATION;
97
98 /* Initialize the object handling fields. */
99 atomic_set(&asoc->base.refcnt, 1);
100 asoc->base.dead = 0;
101 asoc->base.malloced = 0;
102
103 /* Initialize the bind addr area. */
104 sctp_bind_addr_init(&asoc->base.bind_addr, ep->base.bind_addr.port);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105
106 asoc->state = SCTP_STATE_CLOSED;
107
108 /* Set these values from the socket values, a conversion between
109 * millsecons to seconds/microseconds must also be done.
110 */
111 asoc->cookie_life.tv_sec = sp->assocparams.sasoc_cookie_life / 1000;
112 asoc->cookie_life.tv_usec = (sp->assocparams.sasoc_cookie_life % 1000)
113 * 1000;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 asoc->frag_point = 0;
115
116 /* Set the association max_retrans and RTO values from the
117 * socket values.
118 */
119 asoc->max_retrans = sp->assocparams.sasoc_asocmaxrxt;
120 asoc->rto_initial = msecs_to_jiffies(sp->rtoinfo.srto_initial);
121 asoc->rto_max = msecs_to_jiffies(sp->rtoinfo.srto_max);
122 asoc->rto_min = msecs_to_jiffies(sp->rtoinfo.srto_min);
123
124 asoc->overall_error_count = 0;
125
Frank Filz52ccb8e2005-12-22 11:36:46 -0800126 /* Initialize the association's heartbeat interval based on the
127 * sock configured value.
128 */
129 asoc->hbinterval = msecs_to_jiffies(sp->hbinterval);
130
131 /* Initialize path max retrans value. */
132 asoc->pathmaxrxt = sp->pathmaxrxt;
133
134 /* Initialize default path MTU. */
135 asoc->pathmtu = sp->pathmtu;
136
137 /* Set association default SACK delay */
138 asoc->sackdelay = msecs_to_jiffies(sp->sackdelay);
Wei Yongjund364d922008-05-09 15:13:26 -0700139 asoc->sackfreq = sp->sackfreq;
Frank Filz52ccb8e2005-12-22 11:36:46 -0800140
141 /* Set the association default flags controlling
142 * Heartbeat, SACK delay, and Path MTU Discovery.
143 */
144 asoc->param_flags = sp->param_flags;
145
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146 /* Initialize the maximum mumber of new data packets that can be sent
147 * in a burst.
148 */
Vlad Yasevich70331572007-03-23 11:34:36 -0700149 asoc->max_burst = sp->max_burst;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150
Vladislav Yasevich1e7d3d92005-11-11 16:06:16 -0800151 /* initialize association timers */
152 asoc->timeouts[SCTP_EVENT_TIMEOUT_NONE] = 0;
153 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] = asoc->rto_initial;
154 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] = asoc->rto_initial;
155 asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = asoc->rto_initial;
156 asoc->timeouts[SCTP_EVENT_TIMEOUT_T3_RTX] = 0;
157 asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = 0;
158
159 /* sctpimpguide Section 2.12.2
160 * If the 'T5-shutdown-guard' timer is used, it SHOULD be set to the
161 * recommended value of 5 times 'RTO.Max'.
162 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900163 asoc->timeouts[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD]
Vladislav Yasevich1e7d3d92005-11-11 16:06:16 -0800164 = 5 * asoc->rto_max;
165
166 asoc->timeouts[SCTP_EVENT_TIMEOUT_HEARTBEAT] = 0;
Frank Filz52ccb8e2005-12-22 11:36:46 -0800167 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] = asoc->sackdelay;
Vladislav Yasevich1e7d3d92005-11-11 16:06:16 -0800168 asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE] =
169 sp->autoclose * HZ;
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900170
Vladislav Yasevich1e7d3d92005-11-11 16:06:16 -0800171 /* Initilizes the timers */
Pavel Emelyanovb24b8a22008-01-23 21:20:07 -0800172 for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i)
173 setup_timer(&asoc->timers[i], sctp_timer_events[i],
174 (unsigned long)asoc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175
176 /* Pull default initialization values from the sock options.
177 * Note: This assumes that the values have already been
178 * validated in the sock.
179 */
180 asoc->c.sinit_max_instreams = sp->initmsg.sinit_max_instreams;
181 asoc->c.sinit_num_ostreams = sp->initmsg.sinit_num_ostreams;
182 asoc->max_init_attempts = sp->initmsg.sinit_max_attempts;
183
184 asoc->max_init_timeo =
185 msecs_to_jiffies(sp->initmsg.sinit_max_init_timeo);
186
187 /* Allocate storage for the ssnmap after the inbound and outbound
188 * streams have been negotiated during Init.
189 */
190 asoc->ssnmap = NULL;
191
192 /* Set the local window size for receive.
193 * This is also the rcvbuf space per association.
194 * RFC 6 - A SCTP receiver MUST be able to receive a minimum of
195 * 1500 bytes in one SCTP packet.
196 */
Neil Horman049b3ff2005-11-11 16:08:24 -0800197 if ((sk->sk_rcvbuf/2) < SCTP_DEFAULT_MINWINDOW)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198 asoc->rwnd = SCTP_DEFAULT_MINWINDOW;
199 else
Neil Horman049b3ff2005-11-11 16:08:24 -0800200 asoc->rwnd = sk->sk_rcvbuf/2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201
202 asoc->a_rwnd = asoc->rwnd;
203
204 asoc->rwnd_over = 0;
205
206 /* Use my own max window until I learn something better. */
207 asoc->peer.rwnd = SCTP_DEFAULT_MAXWINDOW;
208
209 /* Set the sndbuf size for transmit. */
210 asoc->sndbuf_used = 0;
211
Neil Horman049b3ff2005-11-11 16:08:24 -0800212 /* Initialize the receive memory counter */
213 atomic_set(&asoc->rmem_alloc, 0);
214
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215 init_waitqueue_head(&asoc->wait);
216
217 asoc->c.my_vtag = sctp_generate_tag(ep);
218 asoc->peer.i.init_tag = 0; /* INIT needs a vtag of 0. */
219 asoc->c.peer_vtag = 0;
220 asoc->c.my_ttag = 0;
221 asoc->c.peer_ttag = 0;
222 asoc->c.my_port = ep->base.bind_addr.port;
223
224 asoc->c.initial_tsn = sctp_generate_tsn(ep);
225
226 asoc->next_tsn = asoc->c.initial_tsn;
227
228 asoc->ctsn_ack_point = asoc->next_tsn - 1;
229 asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
230 asoc->highest_sacked = asoc->ctsn_ack_point;
231 asoc->last_cwr_tsn = asoc->ctsn_ack_point;
232 asoc->unack_data = 0;
233
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234 /* ADDIP Section 4.1 Asconf Chunk Procedures
235 *
236 * When an endpoint has an ASCONF signaled change to be sent to the
237 * remote endpoint it should do the following:
238 * ...
239 * A2) a serial number should be assigned to the chunk. The serial
240 * number SHOULD be a monotonically increasing number. The serial
241 * numbers SHOULD be initialized at the start of the
242 * association to the same value as the initial TSN.
243 */
244 asoc->addip_serial = asoc->c.initial_tsn;
245
David S. Miller79af02c2005-07-08 21:47:49 -0700246 INIT_LIST_HEAD(&asoc->addip_chunk_list);
Vlad Yasevicha08de642007-12-20 14:11:47 -0800247 INIT_LIST_HEAD(&asoc->asconf_ack_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248
249 /* Make an empty list of remote transport addresses. */
250 INIT_LIST_HEAD(&asoc->peer.transport_addr_list);
Frank Filz3f7a87d2005-06-20 13:14:57 -0700251 asoc->peer.transport_count = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252
253 /* RFC 2960 5.1 Normal Establishment of an Association
254 *
255 * After the reception of the first data chunk in an
256 * association the endpoint must immediately respond with a
257 * sack to acknowledge the data chunk. Subsequent
258 * acknowledgements should be done as described in Section
259 * 6.2.
260 *
261 * [We implement this by telling a new association that it
262 * already received one packet.]
263 */
264 asoc->peer.sack_needed = 1;
Wei Yongjund364d922008-05-09 15:13:26 -0700265 asoc->peer.sack_cnt = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266
Vlad Yasevich73d9c4f2007-10-24 17:24:26 -0400267 /* Assume that the peer will tell us if he recognizes ASCONF
268 * as part of INIT exchange.
269 * The sctp_addip_noauth option is there for backward compatibilty
270 * and will revert old behavior.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271 */
Vlad Yasevich88799fe2007-10-24 17:24:23 -0400272 asoc->peer.asconf_capable = 0;
Vlad Yasevich73d9c4f2007-10-24 17:24:26 -0400273 if (sctp_addip_noauth)
274 asoc->peer.asconf_capable = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275
276 /* Create an input queue. */
277 sctp_inq_init(&asoc->base.inqueue);
David Howellsc4028952006-11-22 14:57:56 +0000278 sctp_inq_set_th_handler(&asoc->base.inqueue, sctp_assoc_bh_rcv);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279
280 /* Create an output queue. */
281 sctp_outq_init(asoc, &asoc->outqueue);
282
283 if (!sctp_ulpq_init(&asoc->ulpq, asoc))
284 goto fail_init;
285
Vlad Yasevich8e1ee182008-10-08 14:18:39 -0700286 memset(&asoc->peer.tsn_map, 0, sizeof(struct sctp_tsnmap));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287
288 asoc->need_ecne = 0;
289
290 asoc->assoc_id = 0;
291
292 /* Assume that peer would support both address types unless we are
293 * told otherwise.
294 */
295 asoc->peer.ipv4_address = 1;
Wei Yongjuna2c39582009-04-07 16:35:11 +0800296 if (asoc->base.sk->sk_family == PF_INET6)
297 asoc->peer.ipv6_address = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298 INIT_LIST_HEAD(&asoc->asocs);
299
300 asoc->autoclose = sp->autoclose;
301
302 asoc->default_stream = sp->default_stream;
303 asoc->default_ppid = sp->default_ppid;
304 asoc->default_flags = sp->default_flags;
305 asoc->default_context = sp->default_context;
306 asoc->default_timetolive = sp->default_timetolive;
Ivan Skytte Jorgensen6ab792f2006-12-13 16:34:22 -0800307 asoc->default_rcv_context = sp->default_rcv_context;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308
Vlad Yasevicha29a5bd2007-09-16 19:31:35 -0700309 /* AUTH related initializations */
310 INIT_LIST_HEAD(&asoc->endpoint_shared_keys);
311 err = sctp_auth_asoc_copy_shkeys(ep, asoc, gfp);
312 if (err)
313 goto fail_init;
314
315 asoc->active_key_id = ep->active_key_id;
316 asoc->asoc_shared_key = NULL;
317
318 asoc->default_hmac_id = 0;
319 /* Save the hmacs and chunks list into this association */
320 if (ep->auth_hmacs_list)
321 memcpy(asoc->c.auth_hmacs, ep->auth_hmacs_list,
322 ntohs(ep->auth_hmacs_list->param_hdr.length));
323 if (ep->auth_chunk_list)
324 memcpy(asoc->c.auth_chunks, ep->auth_chunk_list,
325 ntohs(ep->auth_chunk_list->param_hdr.length));
326
327 /* Get the AUTH random number for this association */
328 p = (sctp_paramhdr_t *)asoc->c.auth_random;
329 p->type = SCTP_PARAM_RANDOM;
330 p->length = htons(sizeof(sctp_paramhdr_t) + SCTP_AUTH_RANDOM_LENGTH);
331 get_random_bytes(p+1, SCTP_AUTH_RANDOM_LENGTH);
332
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333 return asoc;
334
335fail_init:
336 sctp_endpoint_put(asoc->ep);
337 sock_put(asoc->base.sk);
338 return NULL;
339}
340
341/* Allocate and initialize a new association */
342struct sctp_association *sctp_association_new(const struct sctp_endpoint *ep,
343 const struct sock *sk,
Alexey Dobriyan3182cd842005-07-11 20:57:47 -0700344 sctp_scope_t scope,
Al Virodd0fc662005-10-07 07:46:04 +0100345 gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346{
347 struct sctp_association *asoc;
348
349 asoc = t_new(struct sctp_association, gfp);
350 if (!asoc)
351 goto fail;
352
353 if (!sctp_association_init(asoc, ep, sk, scope, gfp))
354 goto fail_init;
355
356 asoc->base.malloced = 1;
357 SCTP_DBG_OBJCNT_INC(assoc);
Frank Filz3f7a87d2005-06-20 13:14:57 -0700358 SCTP_DEBUG_PRINTK("Created asoc %p\n", asoc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359
360 return asoc;
361
362fail_init:
363 kfree(asoc);
364fail:
365 return NULL;
366}
367
368/* Free this association if possible. There may still be users, so
369 * the actual deallocation may be delayed.
370 */
371void sctp_association_free(struct sctp_association *asoc)
372{
373 struct sock *sk = asoc->base.sk;
374 struct sctp_transport *transport;
375 struct list_head *pos, *temp;
376 int i;
377
Vlad Yasevichde76e692006-10-30 18:55:11 -0800378 /* Only real associations count against the endpoint, so
379 * don't bother for if this is a temporary association.
380 */
381 if (!asoc->temp) {
382 list_del(&asoc->asocs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383
Vlad Yasevichde76e692006-10-30 18:55:11 -0800384 /* Decrement the backlog value for a TCP-style listening
385 * socket.
386 */
387 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
388 sk->sk_ack_backlog--;
389 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390
391 /* Mark as dead, so other users can know this structure is
392 * going away.
393 */
394 asoc->base.dead = 1;
395
396 /* Dispose of any data lying around in the outqueue. */
397 sctp_outq_free(&asoc->outqueue);
398
399 /* Dispose of any pending messages for the upper layer. */
400 sctp_ulpq_free(&asoc->ulpq);
401
402 /* Dispose of any pending chunks on the inqueue. */
403 sctp_inq_free(&asoc->base.inqueue);
404
Vlad Yasevich8e1ee182008-10-08 14:18:39 -0700405 sctp_tsnmap_free(&asoc->peer.tsn_map);
406
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407 /* Free ssnmap storage. */
408 sctp_ssnmap_free(asoc->ssnmap);
409
410 /* Clean up the bound address list. */
411 sctp_bind_addr_free(&asoc->base.bind_addr);
412
413 /* Do we need to go through all of our timers and
414 * delete them? To be safe we will try to delete all, but we
415 * should be able to go through and make a guess based
416 * on our state.
417 */
418 for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i) {
419 if (timer_pending(&asoc->timers[i]) &&
420 del_timer(&asoc->timers[i]))
421 sctp_association_put(asoc);
422 }
423
424 /* Free peer's cached cookie. */
Jesper Juhla51482b2005-11-08 09:41:34 -0800425 kfree(asoc->peer.cookie);
Vlad Yasevich730fc3d2007-09-16 19:32:11 -0700426 kfree(asoc->peer.peer_random);
427 kfree(asoc->peer.peer_chunks);
428 kfree(asoc->peer.peer_hmacs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429
430 /* Release the transport structures. */
431 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
432 transport = list_entry(pos, struct sctp_transport, transports);
433 list_del(pos);
434 sctp_transport_free(transport);
435 }
436
Frank Filz3f7a87d2005-06-20 13:14:57 -0700437 asoc->peer.transport_count = 0;
438
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439 /* Free any cached ASCONF_ACK chunk. */
Vlad Yasevicha08de642007-12-20 14:11:47 -0800440 sctp_assoc_free_asconf_acks(asoc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441
442 /* Free any cached ASCONF chunk. */
443 if (asoc->addip_last_asconf)
444 sctp_chunk_free(asoc->addip_last_asconf);
445
Vlad Yasevicha29a5bd2007-09-16 19:31:35 -0700446 /* AUTH - Free the endpoint shared keys */
447 sctp_auth_destroy_keys(&asoc->endpoint_shared_keys);
448
449 /* AUTH - Free the association shared key */
450 sctp_auth_key_put(asoc->asoc_shared_key);
451
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452 sctp_association_put(asoc);
453}
454
455/* Cleanup and free up an association. */
456static void sctp_association_destroy(struct sctp_association *asoc)
457{
458 SCTP_ASSERT(asoc->base.dead, "Assoc is not dead", return);
459
460 sctp_endpoint_put(asoc->ep);
461 sock_put(asoc->base.sk);
462
463 if (asoc->assoc_id != 0) {
464 spin_lock_bh(&sctp_assocs_id_lock);
465 idr_remove(&sctp_assocs_id, asoc->assoc_id);
466 spin_unlock_bh(&sctp_assocs_id_lock);
467 }
468
Ilpo Järvinen547b7922008-07-25 21:43:18 -0700469 WARN_ON(atomic_read(&asoc->rmem_alloc));
Neil Horman049b3ff2005-11-11 16:08:24 -0800470
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471 if (asoc->base.malloced) {
472 kfree(asoc);
473 SCTP_DBG_OBJCNT_DEC(assoc);
474 }
475}
476
477/* Change the primary destination address for the peer. */
478void sctp_assoc_set_primary(struct sctp_association *asoc,
479 struct sctp_transport *transport)
480{
Vlad Yasevich319fa2a2008-06-16 17:00:29 -0700481 int changeover = 0;
482
483 /* it's a changeover only if we already have a primary path
484 * that we are changing
485 */
486 if (asoc->peer.primary_path != NULL &&
487 asoc->peer.primary_path != transport)
488 changeover = 1 ;
489
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490 asoc->peer.primary_path = transport;
491
492 /* Set a default msg_name for events. */
493 memcpy(&asoc->peer.primary_addr, &transport->ipaddr,
494 sizeof(union sctp_addr));
495
496 /* If the primary path is changing, assume that the
497 * user wants to use this new path.
498 */
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700499 if ((transport->state == SCTP_ACTIVE) ||
500 (transport->state == SCTP_UNKNOWN))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501 asoc->peer.active_path = transport;
502
503 /*
504 * SFR-CACC algorithm:
505 * Upon the receipt of a request to change the primary
506 * destination address, on the data structure for the new
507 * primary destination, the sender MUST do the following:
508 *
509 * 1) If CHANGEOVER_ACTIVE is set, then there was a switch
510 * to this destination address earlier. The sender MUST set
511 * CYCLING_CHANGEOVER to indicate that this switch is a
512 * double switch to the same destination address.
513 */
514 if (transport->cacc.changeover_active)
Vlad Yasevich319fa2a2008-06-16 17:00:29 -0700515 transport->cacc.cycling_changeover = changeover;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516
517 /* 2) The sender MUST set CHANGEOVER_ACTIVE to indicate that
518 * a changeover has occurred.
519 */
Vlad Yasevich319fa2a2008-06-16 17:00:29 -0700520 transport->cacc.changeover_active = changeover;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521
522 /* 3) The sender MUST store the next TSN to be sent in
523 * next_tsn_at_change.
524 */
525 transport->cacc.next_tsn_at_change = asoc->next_tsn;
526}
527
Frank Filz3f7a87d2005-06-20 13:14:57 -0700528/* Remove a transport from an association. */
529void sctp_assoc_rm_peer(struct sctp_association *asoc,
530 struct sctp_transport *peer)
531{
532 struct list_head *pos;
533 struct sctp_transport *transport;
534
535 SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_rm_peer:association %p addr: ",
536 " port: %d\n",
537 asoc,
538 (&peer->ipaddr),
Al Virob3f5b3b2006-11-20 17:22:43 -0800539 ntohs(peer->ipaddr.v4.sin_port));
Frank Filz3f7a87d2005-06-20 13:14:57 -0700540
541 /* If we are to remove the current retran_path, update it
542 * to the next peer before removing this peer from the list.
543 */
544 if (asoc->peer.retran_path == peer)
545 sctp_assoc_update_retran_path(asoc);
546
547 /* Remove this peer from the list. */
548 list_del(&peer->transports);
549
550 /* Get the first transport of asoc. */
551 pos = asoc->peer.transport_addr_list.next;
552 transport = list_entry(pos, struct sctp_transport, transports);
553
554 /* Update any entries that match the peer to be deleted. */
555 if (asoc->peer.primary_path == peer)
556 sctp_assoc_set_primary(asoc, transport);
557 if (asoc->peer.active_path == peer)
558 asoc->peer.active_path = transport;
559 if (asoc->peer.last_data_from == peer)
560 asoc->peer.last_data_from = transport;
561
562 /* If we remove the transport an INIT was last sent to, set it to
563 * NULL. Combined with the update of the retran path above, this
564 * will cause the next INIT to be sent to the next available
565 * transport, maintaining the cycle.
566 */
567 if (asoc->init_last_sent_to == peer)
568 asoc->init_last_sent_to = NULL;
569
Wei Yongjun6345b192009-04-26 23:13:35 +0800570 /* If we remove the transport an SHUTDOWN was last sent to, set it
571 * to NULL. Combined with the update of the retran path above, this
572 * will cause the next SHUTDOWN to be sent to the next available
573 * transport, maintaining the cycle.
574 */
575 if (asoc->shutdown_last_sent_to == peer)
576 asoc->shutdown_last_sent_to = NULL;
577
Wei Yongjun10a43ce2009-04-26 23:14:42 +0800578 /* If we remove the transport an ASCONF was last sent to, set it to
579 * NULL.
580 */
581 if (asoc->addip_last_asconf &&
582 asoc->addip_last_asconf->transport == peer)
583 asoc->addip_last_asconf->transport = NULL;
584
Frank Filz3f7a87d2005-06-20 13:14:57 -0700585 asoc->peer.transport_count--;
586
587 sctp_transport_free(peer);
588}
589
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590/* Add a transport address to an association. */
591struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc,
592 const union sctp_addr *addr,
Al Virodd0fc662005-10-07 07:46:04 +0100593 const gfp_t gfp,
Frank Filz3f7a87d2005-06-20 13:14:57 -0700594 const int peer_state)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595{
596 struct sctp_transport *peer;
597 struct sctp_sock *sp;
598 unsigned short port;
599
600 sp = sctp_sk(asoc->base.sk);
601
602 /* AF_INET and AF_INET6 share common port field. */
Al Viro4bdf4b52006-11-20 17:10:20 -0800603 port = ntohs(addr->v4.sin_port);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604
Frank Filz3f7a87d2005-06-20 13:14:57 -0700605 SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_add_peer:association %p addr: ",
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700606 " port: %d state:%d\n",
Frank Filz3f7a87d2005-06-20 13:14:57 -0700607 asoc,
608 addr,
Al Viro4bdf4b52006-11-20 17:10:20 -0800609 port,
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700610 peer_state);
Frank Filz3f7a87d2005-06-20 13:14:57 -0700611
Linus Torvalds1da177e2005-04-16 15:20:36 -0700612 /* Set the port if it has not been set yet. */
613 if (0 == asoc->peer.port)
614 asoc->peer.port = port;
615
616 /* Check to see if this is a duplicate. */
617 peer = sctp_assoc_lookup_paddr(asoc, addr);
Frank Filz3f7a87d2005-06-20 13:14:57 -0700618 if (peer) {
Vlad Yasevichadd52372008-09-18 16:28:27 -0700619 /* An UNKNOWN state is only set on transports added by
620 * user in sctp_connectx() call. Such transports should be
621 * considered CONFIRMED per RFC 4960, Section 5.4.
622 */
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700623 if (peer->state == SCTP_UNKNOWN) {
Vlad Yasevichadd52372008-09-18 16:28:27 -0700624 peer->state = SCTP_ACTIVE;
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700625 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700626 return peer;
Frank Filz3f7a87d2005-06-20 13:14:57 -0700627 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700628
629 peer = sctp_transport_new(addr, gfp);
630 if (!peer)
631 return NULL;
632
633 sctp_transport_set_owner(peer, asoc);
634
Frank Filz52ccb8e2005-12-22 11:36:46 -0800635 /* Initialize the peer's heartbeat interval based on the
636 * association configured value.
637 */
638 peer->hbinterval = asoc->hbinterval;
639
640 /* Set the path max_retrans. */
641 peer->pathmaxrxt = asoc->pathmaxrxt;
642
643 /* Initialize the peer's SACK delay timeout based on the
644 * association configured value.
645 */
646 peer->sackdelay = asoc->sackdelay;
Wei Yongjund364d922008-05-09 15:13:26 -0700647 peer->sackfreq = asoc->sackfreq;
Frank Filz52ccb8e2005-12-22 11:36:46 -0800648
649 /* Enable/disable heartbeat, SACK delay, and path MTU discovery
650 * based on association setting.
651 */
652 peer->param_flags = asoc->param_flags;
653
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654 /* Initialize the pmtu of the transport. */
Frank Filz52ccb8e2005-12-22 11:36:46 -0800655 if (peer->param_flags & SPP_PMTUD_ENABLE)
656 sctp_transport_pmtu(peer);
657 else if (asoc->pathmtu)
658 peer->pathmtu = asoc->pathmtu;
659 else
660 peer->pathmtu = SCTP_DEFAULT_MAXSEGMENT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661
662 /* If this is the first transport addr on this association,
663 * initialize the association PMTU to the peer's PMTU.
664 * If not and the current association PMTU is higher than the new
665 * peer's PMTU, reset the association PMTU to the new peer's PMTU.
666 */
Frank Filz52ccb8e2005-12-22 11:36:46 -0800667 if (asoc->pathmtu)
668 asoc->pathmtu = min_t(int, peer->pathmtu, asoc->pathmtu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669 else
Frank Filz52ccb8e2005-12-22 11:36:46 -0800670 asoc->pathmtu = peer->pathmtu;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671
672 SCTP_DEBUG_PRINTK("sctp_assoc_add_peer:association %p PMTU set to "
Frank Filz52ccb8e2005-12-22 11:36:46 -0800673 "%d\n", asoc, asoc->pathmtu);
Florian Westphal6d0ccba2008-07-18 23:04:39 -0700674 peer->pmtu_pending = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675
Frank Filz52ccb8e2005-12-22 11:36:46 -0800676 asoc->frag_point = sctp_frag_point(sp, asoc->pathmtu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677
678 /* The asoc->peer.port might not be meaningful yet, but
679 * initialize the packet structure anyway.
680 */
681 sctp_packet_init(&peer->packet, peer, asoc->base.bind_addr.port,
682 asoc->peer.port);
683
684 /* 7.2.1 Slow-Start
685 *
686 * o The initial cwnd before DATA transmission or after a sufficiently
687 * long idle period MUST be set to
688 * min(4*MTU, max(2*MTU, 4380 bytes))
689 *
690 * o The initial value of ssthresh MAY be arbitrarily high
691 * (for example, implementations MAY use the size of the
692 * receiver advertised window).
693 */
Frank Filz52ccb8e2005-12-22 11:36:46 -0800694 peer->cwnd = min(4*asoc->pathmtu, max_t(__u32, 2*asoc->pathmtu, 4380));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695
696 /* At this point, we may not have the receiver's advertised window,
697 * so initialize ssthresh to the default value and it will be set
698 * later when we process the INIT.
699 */
700 peer->ssthresh = SCTP_DEFAULT_MAXWINDOW;
701
702 peer->partial_bytes_acked = 0;
703 peer->flight_size = 0;
704
Linus Torvalds1da177e2005-04-16 15:20:36 -0700705 /* Set the transport's RTO.initial value */
706 peer->rto = asoc->rto_initial;
707
Frank Filz3f7a87d2005-06-20 13:14:57 -0700708 /* Set the peer's active state. */
709 peer->state = peer_state;
710
Linus Torvalds1da177e2005-04-16 15:20:36 -0700711 /* Attach the remote transport to our asoc. */
712 list_add_tail(&peer->transports, &asoc->peer.transport_addr_list);
Frank Filz3f7a87d2005-06-20 13:14:57 -0700713 asoc->peer.transport_count++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714
715 /* If we do not yet have a primary path, set one. */
716 if (!asoc->peer.primary_path) {
717 sctp_assoc_set_primary(asoc, peer);
718 asoc->peer.retran_path = peer;
719 }
720
Frank Filz3f7a87d2005-06-20 13:14:57 -0700721 if (asoc->peer.active_path == asoc->peer.retran_path) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700722 asoc->peer.retran_path = peer;
Frank Filz3f7a87d2005-06-20 13:14:57 -0700723 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700724
725 return peer;
726}
727
728/* Delete a transport address from an association. */
729void sctp_assoc_del_peer(struct sctp_association *asoc,
730 const union sctp_addr *addr)
731{
732 struct list_head *pos;
733 struct list_head *temp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700734 struct sctp_transport *transport;
735
736 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
737 transport = list_entry(pos, struct sctp_transport, transports);
738 if (sctp_cmp_addr_exact(addr, &transport->ipaddr)) {
Frank Filz3f7a87d2005-06-20 13:14:57 -0700739 /* Do book keeping for removing the peer and free it. */
740 sctp_assoc_rm_peer(asoc, transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700741 break;
742 }
743 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700744}
745
746/* Lookup a transport by address. */
747struct sctp_transport *sctp_assoc_lookup_paddr(
748 const struct sctp_association *asoc,
749 const union sctp_addr *address)
750{
751 struct sctp_transport *t;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700752
753 /* Cycle through all transports searching for a peer address. */
754
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -0700755 list_for_each_entry(t, &asoc->peer.transport_addr_list,
756 transports) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700757 if (sctp_cmp_addr_exact(address, &t->ipaddr))
758 return t;
759 }
760
761 return NULL;
762}
763
Vlad Yasevich42e30bf2007-12-20 14:08:56 -0800764/* Remove all transports except a give one */
765void sctp_assoc_del_nonprimary_peers(struct sctp_association *asoc,
766 struct sctp_transport *primary)
767{
768 struct sctp_transport *temp;
769 struct sctp_transport *t;
770
771 list_for_each_entry_safe(t, temp, &asoc->peer.transport_addr_list,
772 transports) {
773 /* if the current transport is not the primary one, delete it */
774 if (t != primary)
775 sctp_assoc_rm_peer(asoc, t);
776 }
777
778 return;
779}
780
Linus Torvalds1da177e2005-04-16 15:20:36 -0700781/* Engage in transport control operations.
782 * Mark the transport up or down and send a notification to the user.
783 * Select and update the new active and retran paths.
784 */
785void sctp_assoc_control_transport(struct sctp_association *asoc,
786 struct sctp_transport *transport,
787 sctp_transport_cmd_t command,
788 sctp_sn_error_t error)
789{
790 struct sctp_transport *t = NULL;
791 struct sctp_transport *first;
792 struct sctp_transport *second;
793 struct sctp_ulpevent *event;
Al Viro0906e202006-11-20 17:03:01 -0800794 struct sockaddr_storage addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700795 int spc_state = 0;
796
797 /* Record the transition on the transport. */
798 switch (command) {
799 case SCTP_TRANSPORT_UP:
Vlad Yasevich1ae41142007-03-23 11:32:26 -0700800 /* If we are moving from UNCONFIRMED state due
801 * to heartbeat success, report the SCTP_ADDR_CONFIRMED
802 * state to the user, otherwise report SCTP_ADDR_AVAILABLE.
803 */
804 if (SCTP_UNCONFIRMED == transport->state &&
805 SCTP_HEARTBEAT_SUCCESS == error)
806 spc_state = SCTP_ADDR_CONFIRMED;
807 else
808 spc_state = SCTP_ADDR_AVAILABLE;
Frank Filz3f7a87d2005-06-20 13:14:57 -0700809 transport->state = SCTP_ACTIVE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700810 break;
811
812 case SCTP_TRANSPORT_DOWN:
Vlad Yasevichcc756892007-08-24 19:30:25 +0900813 /* if the transort was never confirmed, do not transition it
814 * to inactive state.
815 */
816 if (transport->state != SCTP_UNCONFIRMED)
817 transport->state = SCTP_INACTIVE;
818
Linus Torvalds1da177e2005-04-16 15:20:36 -0700819 spc_state = SCTP_ADDR_UNREACHABLE;
820 break;
821
822 default:
823 return;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700824 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700825
826 /* Generate and send a SCTP_PEER_ADDR_CHANGE notification to the
827 * user.
828 */
Al Viro0906e202006-11-20 17:03:01 -0800829 memset(&addr, 0, sizeof(struct sockaddr_storage));
Al Viro8cec6b82006-11-20 17:23:01 -0800830 memcpy(&addr, &transport->ipaddr, transport->af_specific->sockaddr_len);
Al Viro0906e202006-11-20 17:03:01 -0800831 event = sctp_ulpevent_make_peer_addr_change(asoc, &addr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700832 0, spc_state, error, GFP_ATOMIC);
833 if (event)
834 sctp_ulpq_tail_event(&asoc->ulpq, event);
835
836 /* Select new active and retran paths. */
837
838 /* Look for the two most recently used active transports.
839 *
840 * This code produces the wrong ordering whenever jiffies
841 * rolls over, but we still get usable transports, so we don't
842 * worry about it.
843 */
844 first = NULL; second = NULL;
845
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -0700846 list_for_each_entry(t, &asoc->peer.transport_addr_list,
847 transports) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700848
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700849 if ((t->state == SCTP_INACTIVE) ||
850 (t->state == SCTP_UNCONFIRMED))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700851 continue;
852 if (!first || t->last_time_heard > first->last_time_heard) {
853 second = first;
854 first = t;
855 }
856 if (!second || t->last_time_heard > second->last_time_heard)
857 second = t;
858 }
859
860 /* RFC 2960 6.4 Multi-Homed SCTP Endpoints
861 *
862 * By default, an endpoint should always transmit to the
863 * primary path, unless the SCTP user explicitly specifies the
864 * destination transport address (and possibly source
865 * transport address) to use.
866 *
867 * [If the primary is active but not most recent, bump the most
868 * recently used transport.]
869 */
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700870 if (((asoc->peer.primary_path->state == SCTP_ACTIVE) ||
871 (asoc->peer.primary_path->state == SCTP_UNKNOWN)) &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700872 first != asoc->peer.primary_path) {
873 second = first;
874 first = asoc->peer.primary_path;
875 }
876
877 /* If we failed to find a usable transport, just camp on the
878 * primary, even if it is inactive.
879 */
880 if (!first) {
881 first = asoc->peer.primary_path;
882 second = asoc->peer.primary_path;
883 }
884
885 /* Set the active and retran transports. */
886 asoc->peer.active_path = first;
887 asoc->peer.retran_path = second;
888}
889
890/* Hold a reference to an association. */
891void sctp_association_hold(struct sctp_association *asoc)
892{
893 atomic_inc(&asoc->base.refcnt);
894}
895
896/* Release a reference to an association and cleanup
897 * if there are no more references.
898 */
899void sctp_association_put(struct sctp_association *asoc)
900{
901 if (atomic_dec_and_test(&asoc->base.refcnt))
902 sctp_association_destroy(asoc);
903}
904
905/* Allocate the next TSN, Transmission Sequence Number, for the given
906 * association.
907 */
908__u32 sctp_association_get_next_tsn(struct sctp_association *asoc)
909{
910 /* From Section 1.6 Serial Number Arithmetic:
911 * Transmission Sequence Numbers wrap around when they reach
912 * 2**32 - 1. That is, the next TSN a DATA chunk MUST use
913 * after transmitting TSN = 2*32 - 1 is TSN = 0.
914 */
915 __u32 retval = asoc->next_tsn;
916 asoc->next_tsn++;
917 asoc->unack_data++;
918
919 return retval;
920}
921
922/* Compare two addresses to see if they match. Wildcard addresses
923 * only match themselves.
924 */
925int sctp_cmp_addr_exact(const union sctp_addr *ss1,
926 const union sctp_addr *ss2)
927{
928 struct sctp_af *af;
929
930 af = sctp_get_af_specific(ss1->sa.sa_family);
931 if (unlikely(!af))
932 return 0;
933
934 return af->cmp_addr(ss1, ss2);
935}
936
937/* Return an ecne chunk to get prepended to a packet.
938 * Note: We are sly and return a shared, prealloced chunk. FIXME:
939 * No we don't, but we could/should.
940 */
941struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc)
942{
943 struct sctp_chunk *chunk;
944
945 /* Send ECNE if needed.
946 * Not being able to allocate a chunk here is not deadly.
947 */
948 if (asoc->need_ecne)
949 chunk = sctp_make_ecne(asoc, asoc->last_ecne_tsn);
950 else
951 chunk = NULL;
952
953 return chunk;
954}
955
956/*
957 * Find which transport this TSN was sent on.
958 */
959struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *asoc,
960 __u32 tsn)
961{
962 struct sctp_transport *active;
963 struct sctp_transport *match;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700964 struct sctp_transport *transport;
965 struct sctp_chunk *chunk;
Al Virodbc16db2006-11-20 17:01:42 -0800966 __be32 key = htonl(tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700967
968 match = NULL;
969
970 /*
971 * FIXME: In general, find a more efficient data structure for
972 * searching.
973 */
974
975 /*
976 * The general strategy is to search each transport's transmitted
977 * list. Return which transport this TSN lives on.
978 *
979 * Let's be hopeful and check the active_path first.
980 * Another optimization would be to know if there is only one
981 * outbound path and not have to look for the TSN at all.
982 *
983 */
984
985 active = asoc->peer.active_path;
986
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -0700987 list_for_each_entry(chunk, &active->transmitted,
988 transmitted_list) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700989
990 if (key == chunk->subh.data_hdr->tsn) {
991 match = active;
992 goto out;
993 }
994 }
995
996 /* If not found, go search all the other transports. */
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -0700997 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
998 transports) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700999
1000 if (transport == active)
1001 break;
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -07001002 list_for_each_entry(chunk, &transport->transmitted,
1003 transmitted_list) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001004 if (key == chunk->subh.data_hdr->tsn) {
1005 match = transport;
1006 goto out;
1007 }
1008 }
1009 }
1010out:
1011 return match;
1012}
1013
1014/* Is this the association we are looking for? */
1015struct sctp_transport *sctp_assoc_is_match(struct sctp_association *asoc,
1016 const union sctp_addr *laddr,
1017 const union sctp_addr *paddr)
1018{
1019 struct sctp_transport *transport;
1020
Al Viroe2fcced2006-11-20 17:08:41 -08001021 if ((htons(asoc->base.bind_addr.port) == laddr->v4.sin_port) &&
1022 (htons(asoc->peer.port) == paddr->v4.sin_port)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001023 transport = sctp_assoc_lookup_paddr(asoc, paddr);
1024 if (!transport)
1025 goto out;
1026
1027 if (sctp_bind_addr_match(&asoc->base.bind_addr, laddr,
1028 sctp_sk(asoc->base.sk)))
1029 goto out;
1030 }
1031 transport = NULL;
1032
1033out:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001034 return transport;
1035}
1036
1037/* Do delayed input processing. This is scheduled by sctp_rcv(). */
David Howellsc4028952006-11-22 14:57:56 +00001038static void sctp_assoc_bh_rcv(struct work_struct *work)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001039{
David Howellsc4028952006-11-22 14:57:56 +00001040 struct sctp_association *asoc =
1041 container_of(work, struct sctp_association,
1042 base.inqueue.immediate);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001043 struct sctp_endpoint *ep;
1044 struct sctp_chunk *chunk;
1045 struct sock *sk;
1046 struct sctp_inq *inqueue;
1047 int state;
1048 sctp_subtype_t subtype;
1049 int error = 0;
1050
1051 /* The association should be held so we should be safe. */
1052 ep = asoc->ep;
1053 sk = asoc->base.sk;
1054
1055 inqueue = &asoc->base.inqueue;
1056 sctp_association_hold(asoc);
1057 while (NULL != (chunk = sctp_inq_pop(inqueue))) {
1058 state = asoc->state;
1059 subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type);
1060
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07001061 /* SCTP-AUTH, Section 6.3:
1062 * The receiver has a list of chunk types which it expects
1063 * to be received only after an AUTH-chunk. This list has
1064 * been sent to the peer during the association setup. It
1065 * MUST silently discard these chunks if they are not placed
1066 * after an AUTH chunk in the packet.
1067 */
1068 if (sctp_auth_recv_cid(subtype.chunk, asoc) && !chunk->auth)
1069 continue;
1070
Linus Torvalds1da177e2005-04-16 15:20:36 -07001071 /* Remember where the last DATA chunk came from so we
1072 * know where to send the SACK.
1073 */
1074 if (sctp_chunk_is_data(chunk))
1075 asoc->peer.last_data_from = chunk->transport;
1076 else
1077 SCTP_INC_STATS(SCTP_MIB_INCTRLCHUNKS);
1078
1079 if (chunk->transport)
1080 chunk->transport->last_time_heard = jiffies;
1081
1082 /* Run through the state machine. */
1083 error = sctp_do_sm(SCTP_EVENT_T_CHUNK, subtype,
1084 state, ep, asoc, chunk, GFP_ATOMIC);
1085
1086 /* Check to see if the association is freed in response to
1087 * the incoming chunk. If so, get out of the while loop.
1088 */
1089 if (asoc->base.dead)
1090 break;
1091
1092 /* If there is an error on chunk, discard this packet. */
1093 if (error && chunk)
1094 chunk->pdiscard = 1;
1095 }
1096 sctp_association_put(asoc);
1097}
1098
1099/* This routine moves an association from its old sk to a new sk. */
1100void sctp_assoc_migrate(struct sctp_association *assoc, struct sock *newsk)
1101{
1102 struct sctp_sock *newsp = sctp_sk(newsk);
1103 struct sock *oldsk = assoc->base.sk;
1104
1105 /* Delete the association from the old endpoint's list of
1106 * associations.
1107 */
1108 list_del_init(&assoc->asocs);
1109
1110 /* Decrement the backlog value for a TCP-style socket. */
1111 if (sctp_style(oldsk, TCP))
1112 oldsk->sk_ack_backlog--;
1113
1114 /* Release references to the old endpoint and the sock. */
1115 sctp_endpoint_put(assoc->ep);
1116 sock_put(assoc->base.sk);
1117
1118 /* Get a reference to the new endpoint. */
1119 assoc->ep = newsp->ep;
1120 sctp_endpoint_hold(assoc->ep);
1121
1122 /* Get a reference to the new sock. */
1123 assoc->base.sk = newsk;
1124 sock_hold(assoc->base.sk);
1125
1126 /* Add the association to the new endpoint's list of associations. */
1127 sctp_endpoint_add_asoc(newsp->ep, assoc);
1128}
1129
1130/* Update an association (possibly from unexpected COOKIE-ECHO processing). */
1131void sctp_assoc_update(struct sctp_association *asoc,
1132 struct sctp_association *new)
1133{
1134 struct sctp_transport *trans;
1135 struct list_head *pos, *temp;
1136
1137 /* Copy in new parameters of peer. */
1138 asoc->c = new->c;
1139 asoc->peer.rwnd = new->peer.rwnd;
1140 asoc->peer.sack_needed = new->peer.sack_needed;
1141 asoc->peer.i = new->peer.i;
Vlad Yasevich8e1ee182008-10-08 14:18:39 -07001142 sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
1143 asoc->peer.i.initial_tsn, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001144
1145 /* Remove any peer addresses not present in the new association. */
1146 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
1147 trans = list_entry(pos, struct sctp_transport, transports);
1148 if (!sctp_assoc_lookup_paddr(new, &trans->ipaddr))
1149 sctp_assoc_del_peer(asoc, &trans->ipaddr);
Vlad Yasevich749bf922007-03-19 17:02:30 -07001150
1151 if (asoc->state >= SCTP_STATE_ESTABLISHED)
1152 sctp_transport_reset(trans);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001153 }
1154
1155 /* If the case is A (association restart), use
1156 * initial_tsn as next_tsn. If the case is B, use
1157 * current next_tsn in case data sent to peer
1158 * has been discarded and needs retransmission.
1159 */
1160 if (asoc->state >= SCTP_STATE_ESTABLISHED) {
1161 asoc->next_tsn = new->next_tsn;
1162 asoc->ctsn_ack_point = new->ctsn_ack_point;
1163 asoc->adv_peer_ack_point = new->adv_peer_ack_point;
1164
1165 /* Reinitialize SSN for both local streams
1166 * and peer's streams.
1167 */
1168 sctp_ssnmap_clear(asoc->ssnmap);
1169
Vlad Yasevich0b58a812007-03-19 17:01:17 -07001170 /* Flush the ULP reassembly and ordered queue.
1171 * Any data there will now be stale and will
1172 * cause problems.
1173 */
1174 sctp_ulpq_flush(&asoc->ulpq);
1175
Vlad Yasevich749bf922007-03-19 17:02:30 -07001176 /* reset the overall association error count so
1177 * that the restarted association doesn't get torn
1178 * down on the next retransmission timer.
1179 */
1180 asoc->overall_error_count = 0;
1181
Linus Torvalds1da177e2005-04-16 15:20:36 -07001182 } else {
1183 /* Add any peer addresses from the new association. */
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -07001184 list_for_each_entry(trans, &new->peer.transport_addr_list,
1185 transports) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001186 if (!sctp_assoc_lookup_paddr(asoc, &trans->ipaddr))
1187 sctp_assoc_add_peer(asoc, &trans->ipaddr,
Sridhar Samudralaad8fec12006-07-21 14:48:50 -07001188 GFP_ATOMIC, trans->state);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001189 }
1190
1191 asoc->ctsn_ack_point = asoc->next_tsn - 1;
1192 asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
1193 if (!asoc->ssnmap) {
1194 /* Move the ssnmap. */
1195 asoc->ssnmap = new->ssnmap;
1196 new->ssnmap = NULL;
1197 }
Vlad Yasevich07d93962007-05-04 13:55:27 -07001198
1199 if (!asoc->assoc_id) {
1200 /* get a new association id since we don't have one
1201 * yet.
1202 */
1203 sctp_assoc_set_id(asoc, GFP_ATOMIC);
1204 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001205 }
Vlad Yasevicha29a5bd2007-09-16 19:31:35 -07001206
Vlad Yasevich730fc3d2007-09-16 19:32:11 -07001207 /* SCTP-AUTH: Save the peer parameters from the new assocaitions
1208 * and also move the association shared keys over
1209 */
1210 kfree(asoc->peer.peer_random);
1211 asoc->peer.peer_random = new->peer.peer_random;
1212 new->peer.peer_random = NULL;
1213
1214 kfree(asoc->peer.peer_chunks);
1215 asoc->peer.peer_chunks = new->peer.peer_chunks;
1216 new->peer.peer_chunks = NULL;
1217
1218 kfree(asoc->peer.peer_hmacs);
1219 asoc->peer.peer_hmacs = new->peer.peer_hmacs;
1220 new->peer.peer_hmacs = NULL;
1221
1222 sctp_auth_key_put(asoc->asoc_shared_key);
1223 sctp_auth_asoc_init_active_key(asoc, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001224}
1225
1226/* Update the retran path for sending a retransmitted packet.
1227 * Round-robin through the active transports, else round-robin
1228 * through the inactive transports as this is the next best thing
1229 * we can try.
1230 */
1231void sctp_assoc_update_retran_path(struct sctp_association *asoc)
1232{
1233 struct sctp_transport *t, *next;
1234 struct list_head *head = &asoc->peer.transport_addr_list;
1235 struct list_head *pos;
1236
Gui Jianfeng4141ddc2008-06-04 12:37:33 -07001237 if (asoc->peer.transport_count == 1)
1238 return;
1239
Linus Torvalds1da177e2005-04-16 15:20:36 -07001240 /* Find the next transport in a round-robin fashion. */
1241 t = asoc->peer.retran_path;
1242 pos = &t->transports;
1243 next = NULL;
1244
1245 while (1) {
1246 /* Skip the head. */
1247 if (pos->next == head)
1248 pos = head->next;
1249 else
1250 pos = pos->next;
1251
1252 t = list_entry(pos, struct sctp_transport, transports);
1253
Gui Jianfeng4141ddc2008-06-04 12:37:33 -07001254 /* We have exhausted the list, but didn't find any
1255 * other active transports. If so, use the next
1256 * transport.
1257 */
1258 if (t == asoc->peer.retran_path) {
1259 t = next;
1260 break;
1261 }
1262
Linus Torvalds1da177e2005-04-16 15:20:36 -07001263 /* Try to find an active transport. */
1264
Sridhar Samudralaad8fec12006-07-21 14:48:50 -07001265 if ((t->state == SCTP_ACTIVE) ||
1266 (t->state == SCTP_UNKNOWN)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001267 break;
1268 } else {
1269 /* Keep track of the next transport in case
1270 * we don't find any active transport.
1271 */
1272 if (!next)
1273 next = t;
1274 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001275 }
1276
1277 asoc->peer.retran_path = t;
Frank Filz3f7a87d2005-06-20 13:14:57 -07001278
1279 SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_update_retran_path:association"
1280 " %p addr: ",
1281 " port: %d\n",
1282 asoc,
1283 (&t->ipaddr),
Al Virob3f5b3b2006-11-20 17:22:43 -08001284 ntohs(t->ipaddr.v4.sin_port));
Frank Filz3f7a87d2005-06-20 13:14:57 -07001285}
1286
Wei Yongjun9919b452009-05-12 21:52:51 +08001287/* Choose the transport for sending retransmit packet. */
1288struct sctp_transport *sctp_assoc_choose_alter_transport(
1289 struct sctp_association *asoc, struct sctp_transport *last_sent_to)
Frank Filz3f7a87d2005-06-20 13:14:57 -07001290{
Wei Yongjun9919b452009-05-12 21:52:51 +08001291 /* If this is the first time packet is sent, use the active path,
1292 * else use the retran path. If the last packet was sent over the
Frank Filz3f7a87d2005-06-20 13:14:57 -07001293 * retran path, update the retran path and use it.
1294 */
Wei Yongjun9919b452009-05-12 21:52:51 +08001295 if (!last_sent_to)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001296 return asoc->peer.active_path;
1297 else {
Wei Yongjun9919b452009-05-12 21:52:51 +08001298 if (last_sent_to == asoc->peer.retran_path)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001299 sctp_assoc_update_retran_path(asoc);
1300 return asoc->peer.retran_path;
1301 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001302}
1303
1304/* Update the association's pmtu and frag_point by going through all the
1305 * transports. This routine is called when a transport's PMTU has changed.
1306 */
1307void sctp_assoc_sync_pmtu(struct sctp_association *asoc)
1308{
1309 struct sctp_transport *t;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001310 __u32 pmtu = 0;
1311
1312 if (!asoc)
1313 return;
1314
1315 /* Get the lowest pmtu of all the transports. */
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -07001316 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1317 transports) {
Vlad Yasevich8a479492007-06-07 14:21:05 -04001318 if (t->pmtu_pending && t->dst) {
1319 sctp_transport_update_pmtu(t, dst_mtu(t->dst));
1320 t->pmtu_pending = 0;
1321 }
Frank Filz52ccb8e2005-12-22 11:36:46 -08001322 if (!pmtu || (t->pathmtu < pmtu))
1323 pmtu = t->pathmtu;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001324 }
1325
1326 if (pmtu) {
1327 struct sctp_sock *sp = sctp_sk(asoc->base.sk);
Frank Filz52ccb8e2005-12-22 11:36:46 -08001328 asoc->pathmtu = pmtu;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001329 asoc->frag_point = sctp_frag_point(sp, pmtu);
1330 }
1331
1332 SCTP_DEBUG_PRINTK("%s: asoc:%p, pmtu:%d, frag_point:%d\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001333 __func__, asoc, asoc->pathmtu, asoc->frag_point);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001334}
1335
1336/* Should we send a SACK to update our peer? */
1337static inline int sctp_peer_needs_update(struct sctp_association *asoc)
1338{
1339 switch (asoc->state) {
1340 case SCTP_STATE_ESTABLISHED:
1341 case SCTP_STATE_SHUTDOWN_PENDING:
1342 case SCTP_STATE_SHUTDOWN_RECEIVED:
1343 case SCTP_STATE_SHUTDOWN_SENT:
1344 if ((asoc->rwnd > asoc->a_rwnd) &&
1345 ((asoc->rwnd - asoc->a_rwnd) >=
Frank Filz52ccb8e2005-12-22 11:36:46 -08001346 min_t(__u32, (asoc->base.sk->sk_rcvbuf >> 1), asoc->pathmtu)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001347 return 1;
1348 break;
1349 default:
1350 break;
1351 }
1352 return 0;
1353}
1354
1355/* Increase asoc's rwnd by len and send any window update SACK if needed. */
1356void sctp_assoc_rwnd_increase(struct sctp_association *asoc, unsigned len)
1357{
1358 struct sctp_chunk *sack;
1359 struct timer_list *timer;
1360
1361 if (asoc->rwnd_over) {
1362 if (asoc->rwnd_over >= len) {
1363 asoc->rwnd_over -= len;
1364 } else {
1365 asoc->rwnd += (len - asoc->rwnd_over);
1366 asoc->rwnd_over = 0;
1367 }
1368 } else {
1369 asoc->rwnd += len;
1370 }
1371
1372 SCTP_DEBUG_PRINTK("%s: asoc %p rwnd increased by %d to (%u, %u) "
Harvey Harrison0dc47872008-03-05 20:47:47 -08001373 "- %u\n", __func__, asoc, len, asoc->rwnd,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001374 asoc->rwnd_over, asoc->a_rwnd);
1375
1376 /* Send a window update SACK if the rwnd has increased by at least the
1377 * minimum of the association's PMTU and half of the receive buffer.
1378 * The algorithm used is similar to the one described in
1379 * Section 4.2.3.3 of RFC 1122.
1380 */
1381 if (sctp_peer_needs_update(asoc)) {
1382 asoc->a_rwnd = asoc->rwnd;
1383 SCTP_DEBUG_PRINTK("%s: Sending window update SACK- asoc: %p "
Harvey Harrison0dc47872008-03-05 20:47:47 -08001384 "rwnd: %u a_rwnd: %u\n", __func__,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001385 asoc, asoc->rwnd, asoc->a_rwnd);
1386 sack = sctp_make_sack(asoc);
1387 if (!sack)
1388 return;
1389
1390 asoc->peer.sack_needed = 0;
1391
1392 sctp_outq_tail(&asoc->outqueue, sack);
1393
1394 /* Stop the SACK timer. */
1395 timer = &asoc->timers[SCTP_EVENT_TIMEOUT_SACK];
1396 if (timer_pending(timer) && del_timer(timer))
1397 sctp_association_put(asoc);
1398 }
1399}
1400
1401/* Decrease asoc's rwnd by len. */
1402void sctp_assoc_rwnd_decrease(struct sctp_association *asoc, unsigned len)
1403{
1404 SCTP_ASSERT(asoc->rwnd, "rwnd zero", return);
1405 SCTP_ASSERT(!asoc->rwnd_over, "rwnd_over not zero", return);
1406 if (asoc->rwnd >= len) {
1407 asoc->rwnd -= len;
1408 } else {
1409 asoc->rwnd_over = len - asoc->rwnd;
1410 asoc->rwnd = 0;
1411 }
1412 SCTP_DEBUG_PRINTK("%s: asoc %p rwnd decreased by %d to (%u, %u)\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001413 __func__, asoc, len, asoc->rwnd,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001414 asoc->rwnd_over);
1415}
1416
1417/* Build the bind address list for the association based on info from the
1418 * local endpoint and the remote peer.
1419 */
Alexey Dobriyan3182cd842005-07-11 20:57:47 -07001420int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
Al Virodd0fc662005-10-07 07:46:04 +01001421 gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001422{
1423 sctp_scope_t scope;
1424 int flags;
1425
1426 /* Use scoping rules to determine the subset of addresses from
1427 * the endpoint.
1428 */
1429 scope = sctp_scope(&asoc->peer.active_path->ipaddr);
1430 flags = (PF_INET6 == asoc->base.sk->sk_family) ? SCTP_ADDR6_ALLOWED : 0;
1431 if (asoc->peer.ipv4_address)
1432 flags |= SCTP_ADDR4_PEERSUPP;
1433 if (asoc->peer.ipv6_address)
1434 flags |= SCTP_ADDR6_PEERSUPP;
1435
1436 return sctp_bind_addr_copy(&asoc->base.bind_addr,
1437 &asoc->ep->base.bind_addr,
1438 scope, gfp, flags);
1439}
1440
1441/* Build the association's bind address list from the cookie. */
1442int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *asoc,
Alexey Dobriyan3182cd842005-07-11 20:57:47 -07001443 struct sctp_cookie *cookie,
Al Virodd0fc662005-10-07 07:46:04 +01001444 gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001445{
1446 int var_size2 = ntohs(cookie->peer_init->chunk_hdr.length);
1447 int var_size3 = cookie->raw_addr_list_len;
1448 __u8 *raw = (__u8 *)cookie->peer_init + var_size2;
1449
1450 return sctp_raw_to_bind_addrs(&asoc->base.bind_addr, raw, var_size3,
1451 asoc->ep->base.bind_addr.port, gfp);
1452}
1453
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001454/* Lookup laddr in the bind address list of an association. */
1455int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001456 const union sctp_addr *laddr)
1457{
Vlad Yasevich559cf712007-09-16 16:03:28 -07001458 int found = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001459
Linus Torvalds1da177e2005-04-16 15:20:36 -07001460 if ((asoc->base.bind_addr.port == ntohs(laddr->v4.sin_port)) &&
1461 sctp_bind_addr_match(&asoc->base.bind_addr, laddr,
Vlad Yasevich559cf712007-09-16 16:03:28 -07001462 sctp_sk(asoc->base.sk)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001463 found = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001464
Linus Torvalds1da177e2005-04-16 15:20:36 -07001465 return found;
1466}
Vlad Yasevich07d93962007-05-04 13:55:27 -07001467
1468/* Set an association id for a given association */
1469int sctp_assoc_set_id(struct sctp_association *asoc, gfp_t gfp)
1470{
1471 int assoc_id;
1472 int error = 0;
Vlad Yasevichc6ba68a2009-06-01 12:41:15 -04001473
1474 /* If the id is already assigned, keep it. */
1475 if (asoc->assoc_id)
1476 return error;
Vlad Yasevich07d93962007-05-04 13:55:27 -07001477retry:
1478 if (unlikely(!idr_pre_get(&sctp_assocs_id, gfp)))
1479 return -ENOMEM;
1480
1481 spin_lock_bh(&sctp_assocs_id_lock);
1482 error = idr_get_new_above(&sctp_assocs_id, (void *)asoc,
1483 1, &assoc_id);
1484 spin_unlock_bh(&sctp_assocs_id_lock);
1485 if (error == -EAGAIN)
1486 goto retry;
1487 else if (error)
1488 return error;
1489
1490 asoc->assoc_id = (sctp_assoc_t) assoc_id;
1491 return error;
1492}
Vlad Yasevicha08de642007-12-20 14:11:47 -08001493
1494/* Free asconf_ack cache */
1495static void sctp_assoc_free_asconf_acks(struct sctp_association *asoc)
1496{
1497 struct sctp_chunk *ack;
1498 struct sctp_chunk *tmp;
1499
1500 list_for_each_entry_safe(ack, tmp, &asoc->asconf_ack_list,
1501 transmitted_list) {
1502 list_del_init(&ack->transmitted_list);
1503 sctp_chunk_free(ack);
1504 }
1505}
1506
1507/* Clean up the ASCONF_ACK queue */
1508void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc)
1509{
1510 struct sctp_chunk *ack;
1511 struct sctp_chunk *tmp;
1512
1513 /* We can remove all the entries from the queue upto
1514 * the "Peer-Sequence-Number".
1515 */
1516 list_for_each_entry_safe(ack, tmp, &asoc->asconf_ack_list,
1517 transmitted_list) {
1518 if (ack->subh.addip_hdr->serial ==
1519 htonl(asoc->peer.addip_serial))
1520 break;
1521
1522 list_del_init(&ack->transmitted_list);
1523 sctp_chunk_free(ack);
1524 }
1525}
1526
1527/* Find the ASCONF_ACK whose serial number matches ASCONF */
1528struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
1529 const struct sctp_association *asoc,
1530 __be32 serial)
1531{
Wei Yongjuna8699812008-02-05 23:35:04 +09001532 struct sctp_chunk *ack;
Vlad Yasevicha08de642007-12-20 14:11:47 -08001533
1534 /* Walk through the list of cached ASCONF-ACKs and find the
1535 * ack chunk whose serial number matches that of the request.
1536 */
1537 list_for_each_entry(ack, &asoc->asconf_ack_list, transmitted_list) {
1538 if (ack->subh.addip_hdr->serial == serial) {
1539 sctp_chunk_hold(ack);
Wei Yongjuna8699812008-02-05 23:35:04 +09001540 return ack;
Vlad Yasevicha08de642007-12-20 14:11:47 -08001541 }
1542 }
1543
Wei Yongjuna8699812008-02-05 23:35:04 +09001544 return NULL;
Vlad Yasevicha08de642007-12-20 14:11:47 -08001545}