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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* SCTP kernel reference Implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999-2000 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 * Copyright (c) 2001 Intel Corp.
6 * Copyright (c) 2001 La Monte H.P. Yarroll
7 *
8 * This file is part of the SCTP kernel reference Implementation
9 *
10 * This module provides the abstraction for an SCTP association.
11 *
12 * The SCTP reference implementation is free software;
13 * 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 *
18 * The SCTP reference implementation is distributed in the hope that it
19 * 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);
Linus Torvalds1da177e2005-04-16 15:20:36 -070064
65
66/* 1st Level Abstractions. */
67
68/* Initialize a new association from provided memory. */
69static struct sctp_association *sctp_association_init(struct sctp_association *asoc,
70 const struct sctp_endpoint *ep,
71 const struct sock *sk,
72 sctp_scope_t scope,
Al Virodd0fc662005-10-07 07:46:04 +010073 gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -070074{
75 struct sctp_sock *sp;
76 int i;
Vlad Yasevicha29a5bd2007-09-16 19:31:35 -070077 sctp_paramhdr_t *p;
78 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -070079
80 /* Retrieve the SCTP per socket area. */
81 sp = sctp_sk((struct sock *)sk);
82
83 /* Init all variables to a known value. */
84 memset(asoc, 0, sizeof(struct sctp_association));
85
86 /* Discarding const is appropriate here. */
87 asoc->ep = (struct sctp_endpoint *)ep;
88 sctp_endpoint_hold(asoc->ep);
89
90 /* Hold the sock. */
91 asoc->base.sk = (struct sock *)sk;
92 sock_hold(asoc->base.sk);
93
94 /* Initialize the common base substructure. */
95 asoc->base.type = SCTP_EP_TYPE_ASSOCIATION;
96
97 /* Initialize the object handling fields. */
98 atomic_set(&asoc->base.refcnt, 1);
99 asoc->base.dead = 0;
100 asoc->base.malloced = 0;
101
102 /* Initialize the bind addr area. */
103 sctp_bind_addr_init(&asoc->base.bind_addr, ep->base.bind_addr.port);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104
105 asoc->state = SCTP_STATE_CLOSED;
106
107 /* Set these values from the socket values, a conversion between
108 * millsecons to seconds/microseconds must also be done.
109 */
110 asoc->cookie_life.tv_sec = sp->assocparams.sasoc_cookie_life / 1000;
111 asoc->cookie_life.tv_usec = (sp->assocparams.sasoc_cookie_life % 1000)
112 * 1000;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113 asoc->frag_point = 0;
114
115 /* Set the association max_retrans and RTO values from the
116 * socket values.
117 */
118 asoc->max_retrans = sp->assocparams.sasoc_asocmaxrxt;
119 asoc->rto_initial = msecs_to_jiffies(sp->rtoinfo.srto_initial);
120 asoc->rto_max = msecs_to_jiffies(sp->rtoinfo.srto_max);
121 asoc->rto_min = msecs_to_jiffies(sp->rtoinfo.srto_min);
122
123 asoc->overall_error_count = 0;
124
Frank Filz52ccb8e2005-12-22 11:36:46 -0800125 /* Initialize the association's heartbeat interval based on the
126 * sock configured value.
127 */
128 asoc->hbinterval = msecs_to_jiffies(sp->hbinterval);
129
130 /* Initialize path max retrans value. */
131 asoc->pathmaxrxt = sp->pathmaxrxt;
132
133 /* Initialize default path MTU. */
134 asoc->pathmtu = sp->pathmtu;
135
136 /* Set association default SACK delay */
137 asoc->sackdelay = msecs_to_jiffies(sp->sackdelay);
138
139 /* Set the association default flags controlling
140 * Heartbeat, SACK delay, and Path MTU Discovery.
141 */
142 asoc->param_flags = sp->param_flags;
143
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 /* Initialize the maximum mumber of new data packets that can be sent
145 * in a burst.
146 */
Vlad Yasevich70331572007-03-23 11:34:36 -0700147 asoc->max_burst = sp->max_burst;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148
Vladislav Yasevich1e7d3d92005-11-11 16:06:16 -0800149 /* initialize association timers */
150 asoc->timeouts[SCTP_EVENT_TIMEOUT_NONE] = 0;
151 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] = asoc->rto_initial;
152 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] = asoc->rto_initial;
153 asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = asoc->rto_initial;
154 asoc->timeouts[SCTP_EVENT_TIMEOUT_T3_RTX] = 0;
155 asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = 0;
156
157 /* sctpimpguide Section 2.12.2
158 * If the 'T5-shutdown-guard' timer is used, it SHOULD be set to the
159 * recommended value of 5 times 'RTO.Max'.
160 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900161 asoc->timeouts[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD]
Vladislav Yasevich1e7d3d92005-11-11 16:06:16 -0800162 = 5 * asoc->rto_max;
163
164 asoc->timeouts[SCTP_EVENT_TIMEOUT_HEARTBEAT] = 0;
Frank Filz52ccb8e2005-12-22 11:36:46 -0800165 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] = asoc->sackdelay;
Vladislav Yasevich1e7d3d92005-11-11 16:06:16 -0800166 asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE] =
167 sp->autoclose * HZ;
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900168
Vladislav Yasevich1e7d3d92005-11-11 16:06:16 -0800169 /* Initilizes the timers */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170 for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171 init_timer(&asoc->timers[i]);
172 asoc->timers[i].function = sctp_timer_events[i];
173 asoc->timers[i].data = (unsigned long) asoc;
174 }
175
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);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247
248 /* Make an empty list of remote transport addresses. */
249 INIT_LIST_HEAD(&asoc->peer.transport_addr_list);
Frank Filz3f7a87d2005-06-20 13:14:57 -0700250 asoc->peer.transport_count = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251
252 /* RFC 2960 5.1 Normal Establishment of an Association
253 *
254 * After the reception of the first data chunk in an
255 * association the endpoint must immediately respond with a
256 * sack to acknowledge the data chunk. Subsequent
257 * acknowledgements should be done as described in Section
258 * 6.2.
259 *
260 * [We implement this by telling a new association that it
261 * already received one packet.]
262 */
263 asoc->peer.sack_needed = 1;
264
Vlad Yasevich73d9c4f2007-10-24 17:24:26 -0400265 /* Assume that the peer will tell us if he recognizes ASCONF
266 * as part of INIT exchange.
267 * The sctp_addip_noauth option is there for backward compatibilty
268 * and will revert old behavior.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269 */
Vlad Yasevich88799fe2007-10-24 17:24:23 -0400270 asoc->peer.asconf_capable = 0;
Vlad Yasevich73d9c4f2007-10-24 17:24:26 -0400271 if (sctp_addip_noauth)
272 asoc->peer.asconf_capable = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273
274 /* Create an input queue. */
275 sctp_inq_init(&asoc->base.inqueue);
David Howellsc4028952006-11-22 14:57:56 +0000276 sctp_inq_set_th_handler(&asoc->base.inqueue, sctp_assoc_bh_rcv);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277
278 /* Create an output queue. */
279 sctp_outq_init(asoc, &asoc->outqueue);
280
281 if (!sctp_ulpq_init(&asoc->ulpq, asoc))
282 goto fail_init;
283
284 /* Set up the tsn tracking. */
285 sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_SIZE, 0);
286
287 asoc->need_ecne = 0;
288
289 asoc->assoc_id = 0;
290
291 /* Assume that peer would support both address types unless we are
292 * told otherwise.
293 */
294 asoc->peer.ipv4_address = 1;
295 asoc->peer.ipv6_address = 1;
296 INIT_LIST_HEAD(&asoc->asocs);
297
298 asoc->autoclose = sp->autoclose;
299
300 asoc->default_stream = sp->default_stream;
301 asoc->default_ppid = sp->default_ppid;
302 asoc->default_flags = sp->default_flags;
303 asoc->default_context = sp->default_context;
304 asoc->default_timetolive = sp->default_timetolive;
Ivan Skytte Jorgensen6ab792f2006-12-13 16:34:22 -0800305 asoc->default_rcv_context = sp->default_rcv_context;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700306
Vlad Yasevicha29a5bd2007-09-16 19:31:35 -0700307 /* AUTH related initializations */
308 INIT_LIST_HEAD(&asoc->endpoint_shared_keys);
309 err = sctp_auth_asoc_copy_shkeys(ep, asoc, gfp);
310 if (err)
311 goto fail_init;
312
313 asoc->active_key_id = ep->active_key_id;
314 asoc->asoc_shared_key = NULL;
315
316 asoc->default_hmac_id = 0;
317 /* Save the hmacs and chunks list into this association */
318 if (ep->auth_hmacs_list)
319 memcpy(asoc->c.auth_hmacs, ep->auth_hmacs_list,
320 ntohs(ep->auth_hmacs_list->param_hdr.length));
321 if (ep->auth_chunk_list)
322 memcpy(asoc->c.auth_chunks, ep->auth_chunk_list,
323 ntohs(ep->auth_chunk_list->param_hdr.length));
324
325 /* Get the AUTH random number for this association */
326 p = (sctp_paramhdr_t *)asoc->c.auth_random;
327 p->type = SCTP_PARAM_RANDOM;
328 p->length = htons(sizeof(sctp_paramhdr_t) + SCTP_AUTH_RANDOM_LENGTH);
329 get_random_bytes(p+1, SCTP_AUTH_RANDOM_LENGTH);
330
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331 return asoc;
332
333fail_init:
334 sctp_endpoint_put(asoc->ep);
335 sock_put(asoc->base.sk);
336 return NULL;
337}
338
339/* Allocate and initialize a new association */
340struct sctp_association *sctp_association_new(const struct sctp_endpoint *ep,
341 const struct sock *sk,
Alexey Dobriyan3182cd842005-07-11 20:57:47 -0700342 sctp_scope_t scope,
Al Virodd0fc662005-10-07 07:46:04 +0100343 gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344{
345 struct sctp_association *asoc;
346
347 asoc = t_new(struct sctp_association, gfp);
348 if (!asoc)
349 goto fail;
350
351 if (!sctp_association_init(asoc, ep, sk, scope, gfp))
352 goto fail_init;
353
354 asoc->base.malloced = 1;
355 SCTP_DBG_OBJCNT_INC(assoc);
Frank Filz3f7a87d2005-06-20 13:14:57 -0700356 SCTP_DEBUG_PRINTK("Created asoc %p\n", asoc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700357
358 return asoc;
359
360fail_init:
361 kfree(asoc);
362fail:
363 return NULL;
364}
365
366/* Free this association if possible. There may still be users, so
367 * the actual deallocation may be delayed.
368 */
369void sctp_association_free(struct sctp_association *asoc)
370{
371 struct sock *sk = asoc->base.sk;
372 struct sctp_transport *transport;
373 struct list_head *pos, *temp;
374 int i;
375
Vlad Yasevichde76e692006-10-30 18:55:11 -0800376 /* Only real associations count against the endpoint, so
377 * don't bother for if this is a temporary association.
378 */
379 if (!asoc->temp) {
380 list_del(&asoc->asocs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381
Vlad Yasevichde76e692006-10-30 18:55:11 -0800382 /* Decrement the backlog value for a TCP-style listening
383 * socket.
384 */
385 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
386 sk->sk_ack_backlog--;
387 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388
389 /* Mark as dead, so other users can know this structure is
390 * going away.
391 */
392 asoc->base.dead = 1;
393
394 /* Dispose of any data lying around in the outqueue. */
395 sctp_outq_free(&asoc->outqueue);
396
397 /* Dispose of any pending messages for the upper layer. */
398 sctp_ulpq_free(&asoc->ulpq);
399
400 /* Dispose of any pending chunks on the inqueue. */
401 sctp_inq_free(&asoc->base.inqueue);
402
403 /* Free ssnmap storage. */
404 sctp_ssnmap_free(asoc->ssnmap);
405
406 /* Clean up the bound address list. */
407 sctp_bind_addr_free(&asoc->base.bind_addr);
408
409 /* Do we need to go through all of our timers and
410 * delete them? To be safe we will try to delete all, but we
411 * should be able to go through and make a guess based
412 * on our state.
413 */
414 for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i) {
415 if (timer_pending(&asoc->timers[i]) &&
416 del_timer(&asoc->timers[i]))
417 sctp_association_put(asoc);
418 }
419
420 /* Free peer's cached cookie. */
Jesper Juhla51482b2005-11-08 09:41:34 -0800421 kfree(asoc->peer.cookie);
Vlad Yasevich730fc3d2007-09-16 19:32:11 -0700422 kfree(asoc->peer.peer_random);
423 kfree(asoc->peer.peer_chunks);
424 kfree(asoc->peer.peer_hmacs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425
426 /* Release the transport structures. */
427 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
428 transport = list_entry(pos, struct sctp_transport, transports);
429 list_del(pos);
430 sctp_transport_free(transport);
431 }
432
Frank Filz3f7a87d2005-06-20 13:14:57 -0700433 asoc->peer.transport_count = 0;
434
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435 /* Free any cached ASCONF_ACK chunk. */
436 if (asoc->addip_last_asconf_ack)
437 sctp_chunk_free(asoc->addip_last_asconf_ack);
438
439 /* Free any cached ASCONF chunk. */
440 if (asoc->addip_last_asconf)
441 sctp_chunk_free(asoc->addip_last_asconf);
442
Vlad Yasevicha29a5bd2007-09-16 19:31:35 -0700443 /* AUTH - Free the endpoint shared keys */
444 sctp_auth_destroy_keys(&asoc->endpoint_shared_keys);
445
446 /* AUTH - Free the association shared key */
447 sctp_auth_key_put(asoc->asoc_shared_key);
448
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449 sctp_association_put(asoc);
450}
451
452/* Cleanup and free up an association. */
453static void sctp_association_destroy(struct sctp_association *asoc)
454{
455 SCTP_ASSERT(asoc->base.dead, "Assoc is not dead", return);
456
457 sctp_endpoint_put(asoc->ep);
458 sock_put(asoc->base.sk);
459
460 if (asoc->assoc_id != 0) {
461 spin_lock_bh(&sctp_assocs_id_lock);
462 idr_remove(&sctp_assocs_id, asoc->assoc_id);
463 spin_unlock_bh(&sctp_assocs_id_lock);
464 }
465
Neil Horman049b3ff2005-11-11 16:08:24 -0800466 BUG_TRAP(!atomic_read(&asoc->rmem_alloc));
467
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468 if (asoc->base.malloced) {
469 kfree(asoc);
470 SCTP_DBG_OBJCNT_DEC(assoc);
471 }
472}
473
474/* Change the primary destination address for the peer. */
475void sctp_assoc_set_primary(struct sctp_association *asoc,
476 struct sctp_transport *transport)
477{
478 asoc->peer.primary_path = transport;
479
480 /* Set a default msg_name for events. */
481 memcpy(&asoc->peer.primary_addr, &transport->ipaddr,
482 sizeof(union sctp_addr));
483
484 /* If the primary path is changing, assume that the
485 * user wants to use this new path.
486 */
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700487 if ((transport->state == SCTP_ACTIVE) ||
488 (transport->state == SCTP_UNKNOWN))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489 asoc->peer.active_path = transport;
490
491 /*
492 * SFR-CACC algorithm:
493 * Upon the receipt of a request to change the primary
494 * destination address, on the data structure for the new
495 * primary destination, the sender MUST do the following:
496 *
497 * 1) If CHANGEOVER_ACTIVE is set, then there was a switch
498 * to this destination address earlier. The sender MUST set
499 * CYCLING_CHANGEOVER to indicate that this switch is a
500 * double switch to the same destination address.
501 */
502 if (transport->cacc.changeover_active)
503 transport->cacc.cycling_changeover = 1;
504
505 /* 2) The sender MUST set CHANGEOVER_ACTIVE to indicate that
506 * a changeover has occurred.
507 */
508 transport->cacc.changeover_active = 1;
509
510 /* 3) The sender MUST store the next TSN to be sent in
511 * next_tsn_at_change.
512 */
513 transport->cacc.next_tsn_at_change = asoc->next_tsn;
514}
515
Frank Filz3f7a87d2005-06-20 13:14:57 -0700516/* Remove a transport from an association. */
517void sctp_assoc_rm_peer(struct sctp_association *asoc,
518 struct sctp_transport *peer)
519{
520 struct list_head *pos;
521 struct sctp_transport *transport;
522
523 SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_rm_peer:association %p addr: ",
524 " port: %d\n",
525 asoc,
526 (&peer->ipaddr),
Al Virob3f5b3b2006-11-20 17:22:43 -0800527 ntohs(peer->ipaddr.v4.sin_port));
Frank Filz3f7a87d2005-06-20 13:14:57 -0700528
529 /* If we are to remove the current retran_path, update it
530 * to the next peer before removing this peer from the list.
531 */
532 if (asoc->peer.retran_path == peer)
533 sctp_assoc_update_retran_path(asoc);
534
535 /* Remove this peer from the list. */
536 list_del(&peer->transports);
537
538 /* Get the first transport of asoc. */
539 pos = asoc->peer.transport_addr_list.next;
540 transport = list_entry(pos, struct sctp_transport, transports);
541
542 /* Update any entries that match the peer to be deleted. */
543 if (asoc->peer.primary_path == peer)
544 sctp_assoc_set_primary(asoc, transport);
545 if (asoc->peer.active_path == peer)
546 asoc->peer.active_path = transport;
547 if (asoc->peer.last_data_from == peer)
548 asoc->peer.last_data_from = transport;
549
550 /* If we remove the transport an INIT was last sent to, set it to
551 * NULL. Combined with the update of the retran path above, this
552 * will cause the next INIT to be sent to the next available
553 * transport, maintaining the cycle.
554 */
555 if (asoc->init_last_sent_to == peer)
556 asoc->init_last_sent_to = NULL;
557
558 asoc->peer.transport_count--;
559
560 sctp_transport_free(peer);
561}
562
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563/* Add a transport address to an association. */
564struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc,
565 const union sctp_addr *addr,
Al Virodd0fc662005-10-07 07:46:04 +0100566 const gfp_t gfp,
Frank Filz3f7a87d2005-06-20 13:14:57 -0700567 const int peer_state)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568{
569 struct sctp_transport *peer;
570 struct sctp_sock *sp;
571 unsigned short port;
572
573 sp = sctp_sk(asoc->base.sk);
574
575 /* AF_INET and AF_INET6 share common port field. */
Al Viro4bdf4b52006-11-20 17:10:20 -0800576 port = ntohs(addr->v4.sin_port);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577
Frank Filz3f7a87d2005-06-20 13:14:57 -0700578 SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_add_peer:association %p addr: ",
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700579 " port: %d state:%d\n",
Frank Filz3f7a87d2005-06-20 13:14:57 -0700580 asoc,
581 addr,
Al Viro4bdf4b52006-11-20 17:10:20 -0800582 port,
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700583 peer_state);
Frank Filz3f7a87d2005-06-20 13:14:57 -0700584
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585 /* Set the port if it has not been set yet. */
586 if (0 == asoc->peer.port)
587 asoc->peer.port = port;
588
589 /* Check to see if this is a duplicate. */
590 peer = sctp_assoc_lookup_paddr(asoc, addr);
Frank Filz3f7a87d2005-06-20 13:14:57 -0700591 if (peer) {
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700592 if (peer->state == SCTP_UNKNOWN) {
593 if (peer_state == SCTP_ACTIVE)
594 peer->state = SCTP_ACTIVE;
595 if (peer_state == SCTP_UNCONFIRMED)
596 peer->state = SCTP_UNCONFIRMED;
597 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700598 return peer;
Frank Filz3f7a87d2005-06-20 13:14:57 -0700599 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700600
601 peer = sctp_transport_new(addr, gfp);
602 if (!peer)
603 return NULL;
604
605 sctp_transport_set_owner(peer, asoc);
606
Frank Filz52ccb8e2005-12-22 11:36:46 -0800607 /* Initialize the peer's heartbeat interval based on the
608 * association configured value.
609 */
610 peer->hbinterval = asoc->hbinterval;
611
612 /* Set the path max_retrans. */
613 peer->pathmaxrxt = asoc->pathmaxrxt;
614
615 /* Initialize the peer's SACK delay timeout based on the
616 * association configured value.
617 */
618 peer->sackdelay = asoc->sackdelay;
619
620 /* Enable/disable heartbeat, SACK delay, and path MTU discovery
621 * based on association setting.
622 */
623 peer->param_flags = asoc->param_flags;
624
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625 /* Initialize the pmtu of the transport. */
Frank Filz52ccb8e2005-12-22 11:36:46 -0800626 if (peer->param_flags & SPP_PMTUD_ENABLE)
627 sctp_transport_pmtu(peer);
628 else if (asoc->pathmtu)
629 peer->pathmtu = asoc->pathmtu;
630 else
631 peer->pathmtu = SCTP_DEFAULT_MAXSEGMENT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632
633 /* If this is the first transport addr on this association,
634 * initialize the association PMTU to the peer's PMTU.
635 * If not and the current association PMTU is higher than the new
636 * peer's PMTU, reset the association PMTU to the new peer's PMTU.
637 */
Frank Filz52ccb8e2005-12-22 11:36:46 -0800638 if (asoc->pathmtu)
639 asoc->pathmtu = min_t(int, peer->pathmtu, asoc->pathmtu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700640 else
Frank Filz52ccb8e2005-12-22 11:36:46 -0800641 asoc->pathmtu = peer->pathmtu;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700642
643 SCTP_DEBUG_PRINTK("sctp_assoc_add_peer:association %p PMTU set to "
Frank Filz52ccb8e2005-12-22 11:36:46 -0800644 "%d\n", asoc, asoc->pathmtu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700645
Frank Filz52ccb8e2005-12-22 11:36:46 -0800646 asoc->frag_point = sctp_frag_point(sp, asoc->pathmtu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647
648 /* The asoc->peer.port might not be meaningful yet, but
649 * initialize the packet structure anyway.
650 */
651 sctp_packet_init(&peer->packet, peer, asoc->base.bind_addr.port,
652 asoc->peer.port);
653
654 /* 7.2.1 Slow-Start
655 *
656 * o The initial cwnd before DATA transmission or after a sufficiently
657 * long idle period MUST be set to
658 * min(4*MTU, max(2*MTU, 4380 bytes))
659 *
660 * o The initial value of ssthresh MAY be arbitrarily high
661 * (for example, implementations MAY use the size of the
662 * receiver advertised window).
663 */
Frank Filz52ccb8e2005-12-22 11:36:46 -0800664 peer->cwnd = min(4*asoc->pathmtu, max_t(__u32, 2*asoc->pathmtu, 4380));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665
666 /* At this point, we may not have the receiver's advertised window,
667 * so initialize ssthresh to the default value and it will be set
668 * later when we process the INIT.
669 */
670 peer->ssthresh = SCTP_DEFAULT_MAXWINDOW;
671
672 peer->partial_bytes_acked = 0;
673 peer->flight_size = 0;
674
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675 /* Set the transport's RTO.initial value */
676 peer->rto = asoc->rto_initial;
677
Frank Filz3f7a87d2005-06-20 13:14:57 -0700678 /* Set the peer's active state. */
679 peer->state = peer_state;
680
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681 /* Attach the remote transport to our asoc. */
682 list_add_tail(&peer->transports, &asoc->peer.transport_addr_list);
Frank Filz3f7a87d2005-06-20 13:14:57 -0700683 asoc->peer.transport_count++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684
685 /* If we do not yet have a primary path, set one. */
686 if (!asoc->peer.primary_path) {
687 sctp_assoc_set_primary(asoc, peer);
688 asoc->peer.retran_path = peer;
689 }
690
Frank Filz3f7a87d2005-06-20 13:14:57 -0700691 if (asoc->peer.active_path == asoc->peer.retran_path) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700692 asoc->peer.retran_path = peer;
Frank Filz3f7a87d2005-06-20 13:14:57 -0700693 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700694
695 return peer;
696}
697
698/* Delete a transport address from an association. */
699void sctp_assoc_del_peer(struct sctp_association *asoc,
700 const union sctp_addr *addr)
701{
702 struct list_head *pos;
703 struct list_head *temp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700704 struct sctp_transport *transport;
705
706 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
707 transport = list_entry(pos, struct sctp_transport, transports);
708 if (sctp_cmp_addr_exact(addr, &transport->ipaddr)) {
Frank Filz3f7a87d2005-06-20 13:14:57 -0700709 /* Do book keeping for removing the peer and free it. */
710 sctp_assoc_rm_peer(asoc, transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700711 break;
712 }
713 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714}
715
716/* Lookup a transport by address. */
717struct sctp_transport *sctp_assoc_lookup_paddr(
718 const struct sctp_association *asoc,
719 const union sctp_addr *address)
720{
721 struct sctp_transport *t;
722 struct list_head *pos;
723
724 /* Cycle through all transports searching for a peer address. */
725
726 list_for_each(pos, &asoc->peer.transport_addr_list) {
727 t = list_entry(pos, struct sctp_transport, transports);
728 if (sctp_cmp_addr_exact(address, &t->ipaddr))
729 return t;
730 }
731
732 return NULL;
733}
734
735/* Engage in transport control operations.
736 * Mark the transport up or down and send a notification to the user.
737 * Select and update the new active and retran paths.
738 */
739void sctp_assoc_control_transport(struct sctp_association *asoc,
740 struct sctp_transport *transport,
741 sctp_transport_cmd_t command,
742 sctp_sn_error_t error)
743{
744 struct sctp_transport *t = NULL;
745 struct sctp_transport *first;
746 struct sctp_transport *second;
747 struct sctp_ulpevent *event;
Al Viro0906e202006-11-20 17:03:01 -0800748 struct sockaddr_storage addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700749 struct list_head *pos;
750 int spc_state = 0;
751
752 /* Record the transition on the transport. */
753 switch (command) {
754 case SCTP_TRANSPORT_UP:
Vlad Yasevich1ae41142007-03-23 11:32:26 -0700755 /* If we are moving from UNCONFIRMED state due
756 * to heartbeat success, report the SCTP_ADDR_CONFIRMED
757 * state to the user, otherwise report SCTP_ADDR_AVAILABLE.
758 */
759 if (SCTP_UNCONFIRMED == transport->state &&
760 SCTP_HEARTBEAT_SUCCESS == error)
761 spc_state = SCTP_ADDR_CONFIRMED;
762 else
763 spc_state = SCTP_ADDR_AVAILABLE;
Frank Filz3f7a87d2005-06-20 13:14:57 -0700764 transport->state = SCTP_ACTIVE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765 break;
766
767 case SCTP_TRANSPORT_DOWN:
Vlad Yasevichcc756892007-08-24 19:30:25 +0900768 /* if the transort was never confirmed, do not transition it
769 * to inactive state.
770 */
771 if (transport->state != SCTP_UNCONFIRMED)
772 transport->state = SCTP_INACTIVE;
773
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774 spc_state = SCTP_ADDR_UNREACHABLE;
775 break;
776
777 default:
778 return;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700779 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700780
781 /* Generate and send a SCTP_PEER_ADDR_CHANGE notification to the
782 * user.
783 */
Al Viro0906e202006-11-20 17:03:01 -0800784 memset(&addr, 0, sizeof(struct sockaddr_storage));
Al Viro8cec6b82006-11-20 17:23:01 -0800785 memcpy(&addr, &transport->ipaddr, transport->af_specific->sockaddr_len);
Al Viro0906e202006-11-20 17:03:01 -0800786 event = sctp_ulpevent_make_peer_addr_change(asoc, &addr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700787 0, spc_state, error, GFP_ATOMIC);
788 if (event)
789 sctp_ulpq_tail_event(&asoc->ulpq, event);
790
791 /* Select new active and retran paths. */
792
793 /* Look for the two most recently used active transports.
794 *
795 * This code produces the wrong ordering whenever jiffies
796 * rolls over, but we still get usable transports, so we don't
797 * worry about it.
798 */
799 first = NULL; second = NULL;
800
801 list_for_each(pos, &asoc->peer.transport_addr_list) {
802 t = list_entry(pos, struct sctp_transport, transports);
803
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700804 if ((t->state == SCTP_INACTIVE) ||
805 (t->state == SCTP_UNCONFIRMED))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700806 continue;
807 if (!first || t->last_time_heard > first->last_time_heard) {
808 second = first;
809 first = t;
810 }
811 if (!second || t->last_time_heard > second->last_time_heard)
812 second = t;
813 }
814
815 /* RFC 2960 6.4 Multi-Homed SCTP Endpoints
816 *
817 * By default, an endpoint should always transmit to the
818 * primary path, unless the SCTP user explicitly specifies the
819 * destination transport address (and possibly source
820 * transport address) to use.
821 *
822 * [If the primary is active but not most recent, bump the most
823 * recently used transport.]
824 */
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700825 if (((asoc->peer.primary_path->state == SCTP_ACTIVE) ||
826 (asoc->peer.primary_path->state == SCTP_UNKNOWN)) &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700827 first != asoc->peer.primary_path) {
828 second = first;
829 first = asoc->peer.primary_path;
830 }
831
832 /* If we failed to find a usable transport, just camp on the
833 * primary, even if it is inactive.
834 */
835 if (!first) {
836 first = asoc->peer.primary_path;
837 second = asoc->peer.primary_path;
838 }
839
840 /* Set the active and retran transports. */
841 asoc->peer.active_path = first;
842 asoc->peer.retran_path = second;
843}
844
845/* Hold a reference to an association. */
846void sctp_association_hold(struct sctp_association *asoc)
847{
848 atomic_inc(&asoc->base.refcnt);
849}
850
851/* Release a reference to an association and cleanup
852 * if there are no more references.
853 */
854void sctp_association_put(struct sctp_association *asoc)
855{
856 if (atomic_dec_and_test(&asoc->base.refcnt))
857 sctp_association_destroy(asoc);
858}
859
860/* Allocate the next TSN, Transmission Sequence Number, for the given
861 * association.
862 */
863__u32 sctp_association_get_next_tsn(struct sctp_association *asoc)
864{
865 /* From Section 1.6 Serial Number Arithmetic:
866 * Transmission Sequence Numbers wrap around when they reach
867 * 2**32 - 1. That is, the next TSN a DATA chunk MUST use
868 * after transmitting TSN = 2*32 - 1 is TSN = 0.
869 */
870 __u32 retval = asoc->next_tsn;
871 asoc->next_tsn++;
872 asoc->unack_data++;
873
874 return retval;
875}
876
877/* Compare two addresses to see if they match. Wildcard addresses
878 * only match themselves.
879 */
880int sctp_cmp_addr_exact(const union sctp_addr *ss1,
881 const union sctp_addr *ss2)
882{
883 struct sctp_af *af;
884
885 af = sctp_get_af_specific(ss1->sa.sa_family);
886 if (unlikely(!af))
887 return 0;
888
889 return af->cmp_addr(ss1, ss2);
890}
891
892/* Return an ecne chunk to get prepended to a packet.
893 * Note: We are sly and return a shared, prealloced chunk. FIXME:
894 * No we don't, but we could/should.
895 */
896struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc)
897{
898 struct sctp_chunk *chunk;
899
900 /* Send ECNE if needed.
901 * Not being able to allocate a chunk here is not deadly.
902 */
903 if (asoc->need_ecne)
904 chunk = sctp_make_ecne(asoc, asoc->last_ecne_tsn);
905 else
906 chunk = NULL;
907
908 return chunk;
909}
910
911/*
912 * Find which transport this TSN was sent on.
913 */
914struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *asoc,
915 __u32 tsn)
916{
917 struct sctp_transport *active;
918 struct sctp_transport *match;
919 struct list_head *entry, *pos;
920 struct sctp_transport *transport;
921 struct sctp_chunk *chunk;
Al Virodbc16db2006-11-20 17:01:42 -0800922 __be32 key = htonl(tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700923
924 match = NULL;
925
926 /*
927 * FIXME: In general, find a more efficient data structure for
928 * searching.
929 */
930
931 /*
932 * The general strategy is to search each transport's transmitted
933 * list. Return which transport this TSN lives on.
934 *
935 * Let's be hopeful and check the active_path first.
936 * Another optimization would be to know if there is only one
937 * outbound path and not have to look for the TSN at all.
938 *
939 */
940
941 active = asoc->peer.active_path;
942
943 list_for_each(entry, &active->transmitted) {
944 chunk = list_entry(entry, struct sctp_chunk, transmitted_list);
945
946 if (key == chunk->subh.data_hdr->tsn) {
947 match = active;
948 goto out;
949 }
950 }
951
952 /* If not found, go search all the other transports. */
953 list_for_each(pos, &asoc->peer.transport_addr_list) {
954 transport = list_entry(pos, struct sctp_transport, transports);
955
956 if (transport == active)
957 break;
958 list_for_each(entry, &transport->transmitted) {
959 chunk = list_entry(entry, struct sctp_chunk,
960 transmitted_list);
961 if (key == chunk->subh.data_hdr->tsn) {
962 match = transport;
963 goto out;
964 }
965 }
966 }
967out:
968 return match;
969}
970
971/* Is this the association we are looking for? */
972struct sctp_transport *sctp_assoc_is_match(struct sctp_association *asoc,
973 const union sctp_addr *laddr,
974 const union sctp_addr *paddr)
975{
976 struct sctp_transport *transport;
977
Al Viroe2fcced2006-11-20 17:08:41 -0800978 if ((htons(asoc->base.bind_addr.port) == laddr->v4.sin_port) &&
979 (htons(asoc->peer.port) == paddr->v4.sin_port)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700980 transport = sctp_assoc_lookup_paddr(asoc, paddr);
981 if (!transport)
982 goto out;
983
984 if (sctp_bind_addr_match(&asoc->base.bind_addr, laddr,
985 sctp_sk(asoc->base.sk)))
986 goto out;
987 }
988 transport = NULL;
989
990out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700991 return transport;
992}
993
994/* Do delayed input processing. This is scheduled by sctp_rcv(). */
David Howellsc4028952006-11-22 14:57:56 +0000995static void sctp_assoc_bh_rcv(struct work_struct *work)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700996{
David Howellsc4028952006-11-22 14:57:56 +0000997 struct sctp_association *asoc =
998 container_of(work, struct sctp_association,
999 base.inqueue.immediate);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001000 struct sctp_endpoint *ep;
1001 struct sctp_chunk *chunk;
1002 struct sock *sk;
1003 struct sctp_inq *inqueue;
1004 int state;
1005 sctp_subtype_t subtype;
1006 int error = 0;
1007
1008 /* The association should be held so we should be safe. */
1009 ep = asoc->ep;
1010 sk = asoc->base.sk;
1011
1012 inqueue = &asoc->base.inqueue;
1013 sctp_association_hold(asoc);
1014 while (NULL != (chunk = sctp_inq_pop(inqueue))) {
1015 state = asoc->state;
1016 subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type);
1017
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07001018 /* SCTP-AUTH, Section 6.3:
1019 * The receiver has a list of chunk types which it expects
1020 * to be received only after an AUTH-chunk. This list has
1021 * been sent to the peer during the association setup. It
1022 * MUST silently discard these chunks if they are not placed
1023 * after an AUTH chunk in the packet.
1024 */
1025 if (sctp_auth_recv_cid(subtype.chunk, asoc) && !chunk->auth)
1026 continue;
1027
Linus Torvalds1da177e2005-04-16 15:20:36 -07001028 /* Remember where the last DATA chunk came from so we
1029 * know where to send the SACK.
1030 */
1031 if (sctp_chunk_is_data(chunk))
1032 asoc->peer.last_data_from = chunk->transport;
1033 else
1034 SCTP_INC_STATS(SCTP_MIB_INCTRLCHUNKS);
1035
1036 if (chunk->transport)
1037 chunk->transport->last_time_heard = jiffies;
1038
1039 /* Run through the state machine. */
1040 error = sctp_do_sm(SCTP_EVENT_T_CHUNK, subtype,
1041 state, ep, asoc, chunk, GFP_ATOMIC);
1042
1043 /* Check to see if the association is freed in response to
1044 * the incoming chunk. If so, get out of the while loop.
1045 */
1046 if (asoc->base.dead)
1047 break;
1048
1049 /* If there is an error on chunk, discard this packet. */
1050 if (error && chunk)
1051 chunk->pdiscard = 1;
1052 }
1053 sctp_association_put(asoc);
1054}
1055
1056/* This routine moves an association from its old sk to a new sk. */
1057void sctp_assoc_migrate(struct sctp_association *assoc, struct sock *newsk)
1058{
1059 struct sctp_sock *newsp = sctp_sk(newsk);
1060 struct sock *oldsk = assoc->base.sk;
1061
1062 /* Delete the association from the old endpoint's list of
1063 * associations.
1064 */
1065 list_del_init(&assoc->asocs);
1066
1067 /* Decrement the backlog value for a TCP-style socket. */
1068 if (sctp_style(oldsk, TCP))
1069 oldsk->sk_ack_backlog--;
1070
1071 /* Release references to the old endpoint and the sock. */
1072 sctp_endpoint_put(assoc->ep);
1073 sock_put(assoc->base.sk);
1074
1075 /* Get a reference to the new endpoint. */
1076 assoc->ep = newsp->ep;
1077 sctp_endpoint_hold(assoc->ep);
1078
1079 /* Get a reference to the new sock. */
1080 assoc->base.sk = newsk;
1081 sock_hold(assoc->base.sk);
1082
1083 /* Add the association to the new endpoint's list of associations. */
1084 sctp_endpoint_add_asoc(newsp->ep, assoc);
1085}
1086
1087/* Update an association (possibly from unexpected COOKIE-ECHO processing). */
1088void sctp_assoc_update(struct sctp_association *asoc,
1089 struct sctp_association *new)
1090{
1091 struct sctp_transport *trans;
1092 struct list_head *pos, *temp;
1093
1094 /* Copy in new parameters of peer. */
1095 asoc->c = new->c;
1096 asoc->peer.rwnd = new->peer.rwnd;
1097 asoc->peer.sack_needed = new->peer.sack_needed;
1098 asoc->peer.i = new->peer.i;
1099 sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_SIZE,
1100 asoc->peer.i.initial_tsn);
1101
1102 /* Remove any peer addresses not present in the new association. */
1103 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
1104 trans = list_entry(pos, struct sctp_transport, transports);
1105 if (!sctp_assoc_lookup_paddr(new, &trans->ipaddr))
1106 sctp_assoc_del_peer(asoc, &trans->ipaddr);
Vlad Yasevich749bf922007-03-19 17:02:30 -07001107
1108 if (asoc->state >= SCTP_STATE_ESTABLISHED)
1109 sctp_transport_reset(trans);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001110 }
1111
1112 /* If the case is A (association restart), use
1113 * initial_tsn as next_tsn. If the case is B, use
1114 * current next_tsn in case data sent to peer
1115 * has been discarded and needs retransmission.
1116 */
1117 if (asoc->state >= SCTP_STATE_ESTABLISHED) {
1118 asoc->next_tsn = new->next_tsn;
1119 asoc->ctsn_ack_point = new->ctsn_ack_point;
1120 asoc->adv_peer_ack_point = new->adv_peer_ack_point;
1121
1122 /* Reinitialize SSN for both local streams
1123 * and peer's streams.
1124 */
1125 sctp_ssnmap_clear(asoc->ssnmap);
1126
Vlad Yasevich0b58a812007-03-19 17:01:17 -07001127 /* Flush the ULP reassembly and ordered queue.
1128 * Any data there will now be stale and will
1129 * cause problems.
1130 */
1131 sctp_ulpq_flush(&asoc->ulpq);
1132
Vlad Yasevich749bf922007-03-19 17:02:30 -07001133 /* reset the overall association error count so
1134 * that the restarted association doesn't get torn
1135 * down on the next retransmission timer.
1136 */
1137 asoc->overall_error_count = 0;
1138
Linus Torvalds1da177e2005-04-16 15:20:36 -07001139 } else {
1140 /* Add any peer addresses from the new association. */
1141 list_for_each(pos, &new->peer.transport_addr_list) {
1142 trans = list_entry(pos, struct sctp_transport,
1143 transports);
1144 if (!sctp_assoc_lookup_paddr(asoc, &trans->ipaddr))
1145 sctp_assoc_add_peer(asoc, &trans->ipaddr,
Sridhar Samudralaad8fec12006-07-21 14:48:50 -07001146 GFP_ATOMIC, trans->state);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001147 }
1148
1149 asoc->ctsn_ack_point = asoc->next_tsn - 1;
1150 asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
1151 if (!asoc->ssnmap) {
1152 /* Move the ssnmap. */
1153 asoc->ssnmap = new->ssnmap;
1154 new->ssnmap = NULL;
1155 }
Vlad Yasevich07d93962007-05-04 13:55:27 -07001156
1157 if (!asoc->assoc_id) {
1158 /* get a new association id since we don't have one
1159 * yet.
1160 */
1161 sctp_assoc_set_id(asoc, GFP_ATOMIC);
1162 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001163 }
Vlad Yasevicha29a5bd2007-09-16 19:31:35 -07001164
Vlad Yasevich730fc3d2007-09-16 19:32:11 -07001165 /* SCTP-AUTH: Save the peer parameters from the new assocaitions
1166 * and also move the association shared keys over
1167 */
1168 kfree(asoc->peer.peer_random);
1169 asoc->peer.peer_random = new->peer.peer_random;
1170 new->peer.peer_random = NULL;
1171
1172 kfree(asoc->peer.peer_chunks);
1173 asoc->peer.peer_chunks = new->peer.peer_chunks;
1174 new->peer.peer_chunks = NULL;
1175
1176 kfree(asoc->peer.peer_hmacs);
1177 asoc->peer.peer_hmacs = new->peer.peer_hmacs;
1178 new->peer.peer_hmacs = NULL;
1179
1180 sctp_auth_key_put(asoc->asoc_shared_key);
1181 sctp_auth_asoc_init_active_key(asoc, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001182}
1183
1184/* Update the retran path for sending a retransmitted packet.
1185 * Round-robin through the active transports, else round-robin
1186 * through the inactive transports as this is the next best thing
1187 * we can try.
1188 */
1189void sctp_assoc_update_retran_path(struct sctp_association *asoc)
1190{
1191 struct sctp_transport *t, *next;
1192 struct list_head *head = &asoc->peer.transport_addr_list;
1193 struct list_head *pos;
1194
1195 /* Find the next transport in a round-robin fashion. */
1196 t = asoc->peer.retran_path;
1197 pos = &t->transports;
1198 next = NULL;
1199
1200 while (1) {
1201 /* Skip the head. */
1202 if (pos->next == head)
1203 pos = head->next;
1204 else
1205 pos = pos->next;
1206
1207 t = list_entry(pos, struct sctp_transport, transports);
1208
1209 /* Try to find an active transport. */
1210
Sridhar Samudralaad8fec12006-07-21 14:48:50 -07001211 if ((t->state == SCTP_ACTIVE) ||
1212 (t->state == SCTP_UNKNOWN)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001213 break;
1214 } else {
1215 /* Keep track of the next transport in case
1216 * we don't find any active transport.
1217 */
1218 if (!next)
1219 next = t;
1220 }
1221
1222 /* We have exhausted the list, but didn't find any
1223 * other active transports. If so, use the next
1224 * transport.
1225 */
1226 if (t == asoc->peer.retran_path) {
1227 t = next;
1228 break;
1229 }
1230 }
1231
1232 asoc->peer.retran_path = t;
Frank Filz3f7a87d2005-06-20 13:14:57 -07001233
1234 SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_update_retran_path:association"
1235 " %p addr: ",
1236 " port: %d\n",
1237 asoc,
1238 (&t->ipaddr),
Al Virob3f5b3b2006-11-20 17:22:43 -08001239 ntohs(t->ipaddr.v4.sin_port));
Frank Filz3f7a87d2005-06-20 13:14:57 -07001240}
1241
1242/* Choose the transport for sending a INIT packet. */
1243struct sctp_transport *sctp_assoc_choose_init_transport(
1244 struct sctp_association *asoc)
1245{
1246 struct sctp_transport *t;
1247
1248 /* Use the retran path. If the last INIT was sent over the
1249 * retran path, update the retran path and use it.
1250 */
1251 if (!asoc->init_last_sent_to) {
1252 t = asoc->peer.active_path;
1253 } else {
1254 if (asoc->init_last_sent_to == asoc->peer.retran_path)
1255 sctp_assoc_update_retran_path(asoc);
1256 t = asoc->peer.retran_path;
1257 }
1258
1259 SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_update_retran_path:association"
1260 " %p addr: ",
1261 " port: %d\n",
1262 asoc,
1263 (&t->ipaddr),
Al Virob3f5b3b2006-11-20 17:22:43 -08001264 ntohs(t->ipaddr.v4.sin_port));
Frank Filz3f7a87d2005-06-20 13:14:57 -07001265
1266 return t;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001267}
1268
1269/* Choose the transport for sending a SHUTDOWN packet. */
1270struct sctp_transport *sctp_assoc_choose_shutdown_transport(
1271 struct sctp_association *asoc)
1272{
1273 /* If this is the first time SHUTDOWN is sent, use the active path,
1274 * else use the retran path. If the last SHUTDOWN was sent over the
1275 * retran path, update the retran path and use it.
1276 */
1277 if (!asoc->shutdown_last_sent_to)
1278 return asoc->peer.active_path;
1279 else {
1280 if (asoc->shutdown_last_sent_to == asoc->peer.retran_path)
1281 sctp_assoc_update_retran_path(asoc);
1282 return asoc->peer.retran_path;
1283 }
1284
1285}
1286
1287/* Update the association's pmtu and frag_point by going through all the
1288 * transports. This routine is called when a transport's PMTU has changed.
1289 */
1290void sctp_assoc_sync_pmtu(struct sctp_association *asoc)
1291{
1292 struct sctp_transport *t;
1293 struct list_head *pos;
1294 __u32 pmtu = 0;
1295
1296 if (!asoc)
1297 return;
1298
1299 /* Get the lowest pmtu of all the transports. */
1300 list_for_each(pos, &asoc->peer.transport_addr_list) {
1301 t = list_entry(pos, struct sctp_transport, transports);
Vlad Yasevich8a479492007-06-07 14:21:05 -04001302 if (t->pmtu_pending && t->dst) {
1303 sctp_transport_update_pmtu(t, dst_mtu(t->dst));
1304 t->pmtu_pending = 0;
1305 }
Frank Filz52ccb8e2005-12-22 11:36:46 -08001306 if (!pmtu || (t->pathmtu < pmtu))
1307 pmtu = t->pathmtu;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001308 }
1309
1310 if (pmtu) {
1311 struct sctp_sock *sp = sctp_sk(asoc->base.sk);
Frank Filz52ccb8e2005-12-22 11:36:46 -08001312 asoc->pathmtu = pmtu;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001313 asoc->frag_point = sctp_frag_point(sp, pmtu);
1314 }
1315
1316 SCTP_DEBUG_PRINTK("%s: asoc:%p, pmtu:%d, frag_point:%d\n",
Frank Filz52ccb8e2005-12-22 11:36:46 -08001317 __FUNCTION__, asoc, asoc->pathmtu, asoc->frag_point);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001318}
1319
1320/* Should we send a SACK to update our peer? */
1321static inline int sctp_peer_needs_update(struct sctp_association *asoc)
1322{
1323 switch (asoc->state) {
1324 case SCTP_STATE_ESTABLISHED:
1325 case SCTP_STATE_SHUTDOWN_PENDING:
1326 case SCTP_STATE_SHUTDOWN_RECEIVED:
1327 case SCTP_STATE_SHUTDOWN_SENT:
1328 if ((asoc->rwnd > asoc->a_rwnd) &&
1329 ((asoc->rwnd - asoc->a_rwnd) >=
Frank Filz52ccb8e2005-12-22 11:36:46 -08001330 min_t(__u32, (asoc->base.sk->sk_rcvbuf >> 1), asoc->pathmtu)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001331 return 1;
1332 break;
1333 default:
1334 break;
1335 }
1336 return 0;
1337}
1338
1339/* Increase asoc's rwnd by len and send any window update SACK if needed. */
1340void sctp_assoc_rwnd_increase(struct sctp_association *asoc, unsigned len)
1341{
1342 struct sctp_chunk *sack;
1343 struct timer_list *timer;
1344
1345 if (asoc->rwnd_over) {
1346 if (asoc->rwnd_over >= len) {
1347 asoc->rwnd_over -= len;
1348 } else {
1349 asoc->rwnd += (len - asoc->rwnd_over);
1350 asoc->rwnd_over = 0;
1351 }
1352 } else {
1353 asoc->rwnd += len;
1354 }
1355
1356 SCTP_DEBUG_PRINTK("%s: asoc %p rwnd increased by %d to (%u, %u) "
1357 "- %u\n", __FUNCTION__, asoc, len, asoc->rwnd,
1358 asoc->rwnd_over, asoc->a_rwnd);
1359
1360 /* Send a window update SACK if the rwnd has increased by at least the
1361 * minimum of the association's PMTU and half of the receive buffer.
1362 * The algorithm used is similar to the one described in
1363 * Section 4.2.3.3 of RFC 1122.
1364 */
1365 if (sctp_peer_needs_update(asoc)) {
1366 asoc->a_rwnd = asoc->rwnd;
1367 SCTP_DEBUG_PRINTK("%s: Sending window update SACK- asoc: %p "
1368 "rwnd: %u a_rwnd: %u\n", __FUNCTION__,
1369 asoc, asoc->rwnd, asoc->a_rwnd);
1370 sack = sctp_make_sack(asoc);
1371 if (!sack)
1372 return;
1373
1374 asoc->peer.sack_needed = 0;
1375
1376 sctp_outq_tail(&asoc->outqueue, sack);
1377
1378 /* Stop the SACK timer. */
1379 timer = &asoc->timers[SCTP_EVENT_TIMEOUT_SACK];
1380 if (timer_pending(timer) && del_timer(timer))
1381 sctp_association_put(asoc);
1382 }
1383}
1384
1385/* Decrease asoc's rwnd by len. */
1386void sctp_assoc_rwnd_decrease(struct sctp_association *asoc, unsigned len)
1387{
1388 SCTP_ASSERT(asoc->rwnd, "rwnd zero", return);
1389 SCTP_ASSERT(!asoc->rwnd_over, "rwnd_over not zero", return);
1390 if (asoc->rwnd >= len) {
1391 asoc->rwnd -= len;
1392 } else {
1393 asoc->rwnd_over = len - asoc->rwnd;
1394 asoc->rwnd = 0;
1395 }
1396 SCTP_DEBUG_PRINTK("%s: asoc %p rwnd decreased by %d to (%u, %u)\n",
1397 __FUNCTION__, asoc, len, asoc->rwnd,
1398 asoc->rwnd_over);
1399}
1400
1401/* Build the bind address list for the association based on info from the
1402 * local endpoint and the remote peer.
1403 */
Alexey Dobriyan3182cd842005-07-11 20:57:47 -07001404int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
Al Virodd0fc662005-10-07 07:46:04 +01001405 gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001406{
1407 sctp_scope_t scope;
1408 int flags;
1409
1410 /* Use scoping rules to determine the subset of addresses from
1411 * the endpoint.
1412 */
1413 scope = sctp_scope(&asoc->peer.active_path->ipaddr);
1414 flags = (PF_INET6 == asoc->base.sk->sk_family) ? SCTP_ADDR6_ALLOWED : 0;
1415 if (asoc->peer.ipv4_address)
1416 flags |= SCTP_ADDR4_PEERSUPP;
1417 if (asoc->peer.ipv6_address)
1418 flags |= SCTP_ADDR6_PEERSUPP;
1419
1420 return sctp_bind_addr_copy(&asoc->base.bind_addr,
1421 &asoc->ep->base.bind_addr,
1422 scope, gfp, flags);
1423}
1424
1425/* Build the association's bind address list from the cookie. */
1426int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *asoc,
Alexey Dobriyan3182cd842005-07-11 20:57:47 -07001427 struct sctp_cookie *cookie,
Al Virodd0fc662005-10-07 07:46:04 +01001428 gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001429{
1430 int var_size2 = ntohs(cookie->peer_init->chunk_hdr.length);
1431 int var_size3 = cookie->raw_addr_list_len;
1432 __u8 *raw = (__u8 *)cookie->peer_init + var_size2;
1433
1434 return sctp_raw_to_bind_addrs(&asoc->base.bind_addr, raw, var_size3,
1435 asoc->ep->base.bind_addr.port, gfp);
1436}
1437
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001438/* Lookup laddr in the bind address list of an association. */
1439int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001440 const union sctp_addr *laddr)
1441{
Vlad Yasevich559cf712007-09-16 16:03:28 -07001442 int found = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001443
Linus Torvalds1da177e2005-04-16 15:20:36 -07001444 if ((asoc->base.bind_addr.port == ntohs(laddr->v4.sin_port)) &&
1445 sctp_bind_addr_match(&asoc->base.bind_addr, laddr,
Vlad Yasevich559cf712007-09-16 16:03:28 -07001446 sctp_sk(asoc->base.sk)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001447 found = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001448
Linus Torvalds1da177e2005-04-16 15:20:36 -07001449 return found;
1450}
Vlad Yasevich07d93962007-05-04 13:55:27 -07001451
1452/* Set an association id for a given association */
1453int sctp_assoc_set_id(struct sctp_association *asoc, gfp_t gfp)
1454{
1455 int assoc_id;
1456 int error = 0;
1457retry:
1458 if (unlikely(!idr_pre_get(&sctp_assocs_id, gfp)))
1459 return -ENOMEM;
1460
1461 spin_lock_bh(&sctp_assocs_id_lock);
1462 error = idr_get_new_above(&sctp_assocs_id, (void *)asoc,
1463 1, &assoc_id);
1464 spin_unlock_bh(&sctp_assocs_id_lock);
1465 if (error == -EAGAIN)
1466 goto retry;
1467 else if (error)
1468 return error;
1469
1470 asoc->assoc_id = (sctp_assoc_t) assoc_id;
1471 return error;
1472}