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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
265 /* Assume that the peer recongizes ASCONF until reported otherwise
266 * via an ERROR chunk.
267 */
Vlad Yasevich88799fe2007-10-24 17:24:23 -0400268 asoc->peer.asconf_capable = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269
270 /* Create an input queue. */
271 sctp_inq_init(&asoc->base.inqueue);
David Howellsc4028952006-11-22 14:57:56 +0000272 sctp_inq_set_th_handler(&asoc->base.inqueue, sctp_assoc_bh_rcv);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273
274 /* Create an output queue. */
275 sctp_outq_init(asoc, &asoc->outqueue);
276
277 if (!sctp_ulpq_init(&asoc->ulpq, asoc))
278 goto fail_init;
279
280 /* Set up the tsn tracking. */
281 sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_SIZE, 0);
282
283 asoc->need_ecne = 0;
284
285 asoc->assoc_id = 0;
286
287 /* Assume that peer would support both address types unless we are
288 * told otherwise.
289 */
290 asoc->peer.ipv4_address = 1;
291 asoc->peer.ipv6_address = 1;
292 INIT_LIST_HEAD(&asoc->asocs);
293
294 asoc->autoclose = sp->autoclose;
295
296 asoc->default_stream = sp->default_stream;
297 asoc->default_ppid = sp->default_ppid;
298 asoc->default_flags = sp->default_flags;
299 asoc->default_context = sp->default_context;
300 asoc->default_timetolive = sp->default_timetolive;
Ivan Skytte Jorgensen6ab792f2006-12-13 16:34:22 -0800301 asoc->default_rcv_context = sp->default_rcv_context;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302
Vlad Yasevicha29a5bd2007-09-16 19:31:35 -0700303 /* AUTH related initializations */
304 INIT_LIST_HEAD(&asoc->endpoint_shared_keys);
305 err = sctp_auth_asoc_copy_shkeys(ep, asoc, gfp);
306 if (err)
307 goto fail_init;
308
309 asoc->active_key_id = ep->active_key_id;
310 asoc->asoc_shared_key = NULL;
311
312 asoc->default_hmac_id = 0;
313 /* Save the hmacs and chunks list into this association */
314 if (ep->auth_hmacs_list)
315 memcpy(asoc->c.auth_hmacs, ep->auth_hmacs_list,
316 ntohs(ep->auth_hmacs_list->param_hdr.length));
317 if (ep->auth_chunk_list)
318 memcpy(asoc->c.auth_chunks, ep->auth_chunk_list,
319 ntohs(ep->auth_chunk_list->param_hdr.length));
320
321 /* Get the AUTH random number for this association */
322 p = (sctp_paramhdr_t *)asoc->c.auth_random;
323 p->type = SCTP_PARAM_RANDOM;
324 p->length = htons(sizeof(sctp_paramhdr_t) + SCTP_AUTH_RANDOM_LENGTH);
325 get_random_bytes(p+1, SCTP_AUTH_RANDOM_LENGTH);
326
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327 return asoc;
328
329fail_init:
330 sctp_endpoint_put(asoc->ep);
331 sock_put(asoc->base.sk);
332 return NULL;
333}
334
335/* Allocate and initialize a new association */
336struct sctp_association *sctp_association_new(const struct sctp_endpoint *ep,
337 const struct sock *sk,
Alexey Dobriyan3182cd842005-07-11 20:57:47 -0700338 sctp_scope_t scope,
Al Virodd0fc662005-10-07 07:46:04 +0100339 gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340{
341 struct sctp_association *asoc;
342
343 asoc = t_new(struct sctp_association, gfp);
344 if (!asoc)
345 goto fail;
346
347 if (!sctp_association_init(asoc, ep, sk, scope, gfp))
348 goto fail_init;
349
350 asoc->base.malloced = 1;
351 SCTP_DBG_OBJCNT_INC(assoc);
Frank Filz3f7a87d2005-06-20 13:14:57 -0700352 SCTP_DEBUG_PRINTK("Created asoc %p\n", asoc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353
354 return asoc;
355
356fail_init:
357 kfree(asoc);
358fail:
359 return NULL;
360}
361
362/* Free this association if possible. There may still be users, so
363 * the actual deallocation may be delayed.
364 */
365void sctp_association_free(struct sctp_association *asoc)
366{
367 struct sock *sk = asoc->base.sk;
368 struct sctp_transport *transport;
369 struct list_head *pos, *temp;
370 int i;
371
Vlad Yasevichde76e692006-10-30 18:55:11 -0800372 /* Only real associations count against the endpoint, so
373 * don't bother for if this is a temporary association.
374 */
375 if (!asoc->temp) {
376 list_del(&asoc->asocs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377
Vlad Yasevichde76e692006-10-30 18:55:11 -0800378 /* Decrement the backlog value for a TCP-style listening
379 * socket.
380 */
381 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
382 sk->sk_ack_backlog--;
383 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384
385 /* Mark as dead, so other users can know this structure is
386 * going away.
387 */
388 asoc->base.dead = 1;
389
390 /* Dispose of any data lying around in the outqueue. */
391 sctp_outq_free(&asoc->outqueue);
392
393 /* Dispose of any pending messages for the upper layer. */
394 sctp_ulpq_free(&asoc->ulpq);
395
396 /* Dispose of any pending chunks on the inqueue. */
397 sctp_inq_free(&asoc->base.inqueue);
398
399 /* Free ssnmap storage. */
400 sctp_ssnmap_free(asoc->ssnmap);
401
402 /* Clean up the bound address list. */
403 sctp_bind_addr_free(&asoc->base.bind_addr);
404
405 /* Do we need to go through all of our timers and
406 * delete them? To be safe we will try to delete all, but we
407 * should be able to go through and make a guess based
408 * on our state.
409 */
410 for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i) {
411 if (timer_pending(&asoc->timers[i]) &&
412 del_timer(&asoc->timers[i]))
413 sctp_association_put(asoc);
414 }
415
416 /* Free peer's cached cookie. */
Jesper Juhla51482b2005-11-08 09:41:34 -0800417 kfree(asoc->peer.cookie);
Vlad Yasevich730fc3d2007-09-16 19:32:11 -0700418 kfree(asoc->peer.peer_random);
419 kfree(asoc->peer.peer_chunks);
420 kfree(asoc->peer.peer_hmacs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421
422 /* Release the transport structures. */
423 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
424 transport = list_entry(pos, struct sctp_transport, transports);
425 list_del(pos);
426 sctp_transport_free(transport);
427 }
428
Frank Filz3f7a87d2005-06-20 13:14:57 -0700429 asoc->peer.transport_count = 0;
430
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431 /* Free any cached ASCONF_ACK chunk. */
432 if (asoc->addip_last_asconf_ack)
433 sctp_chunk_free(asoc->addip_last_asconf_ack);
434
435 /* Free any cached ASCONF chunk. */
436 if (asoc->addip_last_asconf)
437 sctp_chunk_free(asoc->addip_last_asconf);
438
Vlad Yasevicha29a5bd2007-09-16 19:31:35 -0700439 /* AUTH - Free the endpoint shared keys */
440 sctp_auth_destroy_keys(&asoc->endpoint_shared_keys);
441
442 /* AUTH - Free the association shared key */
443 sctp_auth_key_put(asoc->asoc_shared_key);
444
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445 sctp_association_put(asoc);
446}
447
448/* Cleanup and free up an association. */
449static void sctp_association_destroy(struct sctp_association *asoc)
450{
451 SCTP_ASSERT(asoc->base.dead, "Assoc is not dead", return);
452
453 sctp_endpoint_put(asoc->ep);
454 sock_put(asoc->base.sk);
455
456 if (asoc->assoc_id != 0) {
457 spin_lock_bh(&sctp_assocs_id_lock);
458 idr_remove(&sctp_assocs_id, asoc->assoc_id);
459 spin_unlock_bh(&sctp_assocs_id_lock);
460 }
461
Neil Horman049b3ff2005-11-11 16:08:24 -0800462 BUG_TRAP(!atomic_read(&asoc->rmem_alloc));
463
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464 if (asoc->base.malloced) {
465 kfree(asoc);
466 SCTP_DBG_OBJCNT_DEC(assoc);
467 }
468}
469
470/* Change the primary destination address for the peer. */
471void sctp_assoc_set_primary(struct sctp_association *asoc,
472 struct sctp_transport *transport)
473{
474 asoc->peer.primary_path = transport;
475
476 /* Set a default msg_name for events. */
477 memcpy(&asoc->peer.primary_addr, &transport->ipaddr,
478 sizeof(union sctp_addr));
479
480 /* If the primary path is changing, assume that the
481 * user wants to use this new path.
482 */
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700483 if ((transport->state == SCTP_ACTIVE) ||
484 (transport->state == SCTP_UNKNOWN))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485 asoc->peer.active_path = transport;
486
487 /*
488 * SFR-CACC algorithm:
489 * Upon the receipt of a request to change the primary
490 * destination address, on the data structure for the new
491 * primary destination, the sender MUST do the following:
492 *
493 * 1) If CHANGEOVER_ACTIVE is set, then there was a switch
494 * to this destination address earlier. The sender MUST set
495 * CYCLING_CHANGEOVER to indicate that this switch is a
496 * double switch to the same destination address.
497 */
498 if (transport->cacc.changeover_active)
499 transport->cacc.cycling_changeover = 1;
500
501 /* 2) The sender MUST set CHANGEOVER_ACTIVE to indicate that
502 * a changeover has occurred.
503 */
504 transport->cacc.changeover_active = 1;
505
506 /* 3) The sender MUST store the next TSN to be sent in
507 * next_tsn_at_change.
508 */
509 transport->cacc.next_tsn_at_change = asoc->next_tsn;
510}
511
Frank Filz3f7a87d2005-06-20 13:14:57 -0700512/* Remove a transport from an association. */
513void sctp_assoc_rm_peer(struct sctp_association *asoc,
514 struct sctp_transport *peer)
515{
516 struct list_head *pos;
517 struct sctp_transport *transport;
518
519 SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_rm_peer:association %p addr: ",
520 " port: %d\n",
521 asoc,
522 (&peer->ipaddr),
Al Virob3f5b3b2006-11-20 17:22:43 -0800523 ntohs(peer->ipaddr.v4.sin_port));
Frank Filz3f7a87d2005-06-20 13:14:57 -0700524
525 /* If we are to remove the current retran_path, update it
526 * to the next peer before removing this peer from the list.
527 */
528 if (asoc->peer.retran_path == peer)
529 sctp_assoc_update_retran_path(asoc);
530
531 /* Remove this peer from the list. */
532 list_del(&peer->transports);
533
534 /* Get the first transport of asoc. */
535 pos = asoc->peer.transport_addr_list.next;
536 transport = list_entry(pos, struct sctp_transport, transports);
537
538 /* Update any entries that match the peer to be deleted. */
539 if (asoc->peer.primary_path == peer)
540 sctp_assoc_set_primary(asoc, transport);
541 if (asoc->peer.active_path == peer)
542 asoc->peer.active_path = transport;
543 if (asoc->peer.last_data_from == peer)
544 asoc->peer.last_data_from = transport;
545
546 /* If we remove the transport an INIT was last sent to, set it to
547 * NULL. Combined with the update of the retran path above, this
548 * will cause the next INIT to be sent to the next available
549 * transport, maintaining the cycle.
550 */
551 if (asoc->init_last_sent_to == peer)
552 asoc->init_last_sent_to = NULL;
553
554 asoc->peer.transport_count--;
555
556 sctp_transport_free(peer);
557}
558
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559/* Add a transport address to an association. */
560struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc,
561 const union sctp_addr *addr,
Al Virodd0fc662005-10-07 07:46:04 +0100562 const gfp_t gfp,
Frank Filz3f7a87d2005-06-20 13:14:57 -0700563 const int peer_state)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564{
565 struct sctp_transport *peer;
566 struct sctp_sock *sp;
567 unsigned short port;
568
569 sp = sctp_sk(asoc->base.sk);
570
571 /* AF_INET and AF_INET6 share common port field. */
Al Viro4bdf4b52006-11-20 17:10:20 -0800572 port = ntohs(addr->v4.sin_port);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573
Frank Filz3f7a87d2005-06-20 13:14:57 -0700574 SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_add_peer:association %p addr: ",
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700575 " port: %d state:%d\n",
Frank Filz3f7a87d2005-06-20 13:14:57 -0700576 asoc,
577 addr,
Al Viro4bdf4b52006-11-20 17:10:20 -0800578 port,
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700579 peer_state);
Frank Filz3f7a87d2005-06-20 13:14:57 -0700580
Linus Torvalds1da177e2005-04-16 15:20:36 -0700581 /* Set the port if it has not been set yet. */
582 if (0 == asoc->peer.port)
583 asoc->peer.port = port;
584
585 /* Check to see if this is a duplicate. */
586 peer = sctp_assoc_lookup_paddr(asoc, addr);
Frank Filz3f7a87d2005-06-20 13:14:57 -0700587 if (peer) {
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700588 if (peer->state == SCTP_UNKNOWN) {
589 if (peer_state == SCTP_ACTIVE)
590 peer->state = SCTP_ACTIVE;
591 if (peer_state == SCTP_UNCONFIRMED)
592 peer->state = SCTP_UNCONFIRMED;
593 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700594 return peer;
Frank Filz3f7a87d2005-06-20 13:14:57 -0700595 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700596
597 peer = sctp_transport_new(addr, gfp);
598 if (!peer)
599 return NULL;
600
601 sctp_transport_set_owner(peer, asoc);
602
Frank Filz52ccb8e2005-12-22 11:36:46 -0800603 /* Initialize the peer's heartbeat interval based on the
604 * association configured value.
605 */
606 peer->hbinterval = asoc->hbinterval;
607
608 /* Set the path max_retrans. */
609 peer->pathmaxrxt = asoc->pathmaxrxt;
610
611 /* Initialize the peer's SACK delay timeout based on the
612 * association configured value.
613 */
614 peer->sackdelay = asoc->sackdelay;
615
616 /* Enable/disable heartbeat, SACK delay, and path MTU discovery
617 * based on association setting.
618 */
619 peer->param_flags = asoc->param_flags;
620
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621 /* Initialize the pmtu of the transport. */
Frank Filz52ccb8e2005-12-22 11:36:46 -0800622 if (peer->param_flags & SPP_PMTUD_ENABLE)
623 sctp_transport_pmtu(peer);
624 else if (asoc->pathmtu)
625 peer->pathmtu = asoc->pathmtu;
626 else
627 peer->pathmtu = SCTP_DEFAULT_MAXSEGMENT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700628
629 /* If this is the first transport addr on this association,
630 * initialize the association PMTU to the peer's PMTU.
631 * If not and the current association PMTU is higher than the new
632 * peer's PMTU, reset the association PMTU to the new peer's PMTU.
633 */
Frank Filz52ccb8e2005-12-22 11:36:46 -0800634 if (asoc->pathmtu)
635 asoc->pathmtu = min_t(int, peer->pathmtu, asoc->pathmtu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700636 else
Frank Filz52ccb8e2005-12-22 11:36:46 -0800637 asoc->pathmtu = peer->pathmtu;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700638
639 SCTP_DEBUG_PRINTK("sctp_assoc_add_peer:association %p PMTU set to "
Frank Filz52ccb8e2005-12-22 11:36:46 -0800640 "%d\n", asoc, asoc->pathmtu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700641
Frank Filz52ccb8e2005-12-22 11:36:46 -0800642 asoc->frag_point = sctp_frag_point(sp, asoc->pathmtu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643
644 /* The asoc->peer.port might not be meaningful yet, but
645 * initialize the packet structure anyway.
646 */
647 sctp_packet_init(&peer->packet, peer, asoc->base.bind_addr.port,
648 asoc->peer.port);
649
650 /* 7.2.1 Slow-Start
651 *
652 * o The initial cwnd before DATA transmission or after a sufficiently
653 * long idle period MUST be set to
654 * min(4*MTU, max(2*MTU, 4380 bytes))
655 *
656 * o The initial value of ssthresh MAY be arbitrarily high
657 * (for example, implementations MAY use the size of the
658 * receiver advertised window).
659 */
Frank Filz52ccb8e2005-12-22 11:36:46 -0800660 peer->cwnd = min(4*asoc->pathmtu, max_t(__u32, 2*asoc->pathmtu, 4380));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661
662 /* At this point, we may not have the receiver's advertised window,
663 * so initialize ssthresh to the default value and it will be set
664 * later when we process the INIT.
665 */
666 peer->ssthresh = SCTP_DEFAULT_MAXWINDOW;
667
668 peer->partial_bytes_acked = 0;
669 peer->flight_size = 0;
670
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671 /* Set the transport's RTO.initial value */
672 peer->rto = asoc->rto_initial;
673
Frank Filz3f7a87d2005-06-20 13:14:57 -0700674 /* Set the peer's active state. */
675 peer->state = peer_state;
676
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677 /* Attach the remote transport to our asoc. */
678 list_add_tail(&peer->transports, &asoc->peer.transport_addr_list);
Frank Filz3f7a87d2005-06-20 13:14:57 -0700679 asoc->peer.transport_count++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680
681 /* If we do not yet have a primary path, set one. */
682 if (!asoc->peer.primary_path) {
683 sctp_assoc_set_primary(asoc, peer);
684 asoc->peer.retran_path = peer;
685 }
686
Frank Filz3f7a87d2005-06-20 13:14:57 -0700687 if (asoc->peer.active_path == asoc->peer.retran_path) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700688 asoc->peer.retran_path = peer;
Frank Filz3f7a87d2005-06-20 13:14:57 -0700689 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700690
691 return peer;
692}
693
694/* Delete a transport address from an association. */
695void sctp_assoc_del_peer(struct sctp_association *asoc,
696 const union sctp_addr *addr)
697{
698 struct list_head *pos;
699 struct list_head *temp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700700 struct sctp_transport *transport;
701
702 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
703 transport = list_entry(pos, struct sctp_transport, transports);
704 if (sctp_cmp_addr_exact(addr, &transport->ipaddr)) {
Frank Filz3f7a87d2005-06-20 13:14:57 -0700705 /* Do book keeping for removing the peer and free it. */
706 sctp_assoc_rm_peer(asoc, transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707 break;
708 }
709 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700710}
711
712/* Lookup a transport by address. */
713struct sctp_transport *sctp_assoc_lookup_paddr(
714 const struct sctp_association *asoc,
715 const union sctp_addr *address)
716{
717 struct sctp_transport *t;
718 struct list_head *pos;
719
720 /* Cycle through all transports searching for a peer address. */
721
722 list_for_each(pos, &asoc->peer.transport_addr_list) {
723 t = list_entry(pos, struct sctp_transport, transports);
724 if (sctp_cmp_addr_exact(address, &t->ipaddr))
725 return t;
726 }
727
728 return NULL;
729}
730
731/* Engage in transport control operations.
732 * Mark the transport up or down and send a notification to the user.
733 * Select and update the new active and retran paths.
734 */
735void sctp_assoc_control_transport(struct sctp_association *asoc,
736 struct sctp_transport *transport,
737 sctp_transport_cmd_t command,
738 sctp_sn_error_t error)
739{
740 struct sctp_transport *t = NULL;
741 struct sctp_transport *first;
742 struct sctp_transport *second;
743 struct sctp_ulpevent *event;
Al Viro0906e202006-11-20 17:03:01 -0800744 struct sockaddr_storage addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700745 struct list_head *pos;
746 int spc_state = 0;
747
748 /* Record the transition on the transport. */
749 switch (command) {
750 case SCTP_TRANSPORT_UP:
Vlad Yasevich1ae41142007-03-23 11:32:26 -0700751 /* If we are moving from UNCONFIRMED state due
752 * to heartbeat success, report the SCTP_ADDR_CONFIRMED
753 * state to the user, otherwise report SCTP_ADDR_AVAILABLE.
754 */
755 if (SCTP_UNCONFIRMED == transport->state &&
756 SCTP_HEARTBEAT_SUCCESS == error)
757 spc_state = SCTP_ADDR_CONFIRMED;
758 else
759 spc_state = SCTP_ADDR_AVAILABLE;
Frank Filz3f7a87d2005-06-20 13:14:57 -0700760 transport->state = SCTP_ACTIVE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700761 break;
762
763 case SCTP_TRANSPORT_DOWN:
Vlad Yasevichcc756892007-08-24 19:30:25 +0900764 /* if the transort was never confirmed, do not transition it
765 * to inactive state.
766 */
767 if (transport->state != SCTP_UNCONFIRMED)
768 transport->state = SCTP_INACTIVE;
769
Linus Torvalds1da177e2005-04-16 15:20:36 -0700770 spc_state = SCTP_ADDR_UNREACHABLE;
771 break;
772
773 default:
774 return;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700775 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700776
777 /* Generate and send a SCTP_PEER_ADDR_CHANGE notification to the
778 * user.
779 */
Al Viro0906e202006-11-20 17:03:01 -0800780 memset(&addr, 0, sizeof(struct sockaddr_storage));
Al Viro8cec6b82006-11-20 17:23:01 -0800781 memcpy(&addr, &transport->ipaddr, transport->af_specific->sockaddr_len);
Al Viro0906e202006-11-20 17:03:01 -0800782 event = sctp_ulpevent_make_peer_addr_change(asoc, &addr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700783 0, spc_state, error, GFP_ATOMIC);
784 if (event)
785 sctp_ulpq_tail_event(&asoc->ulpq, event);
786
787 /* Select new active and retran paths. */
788
789 /* Look for the two most recently used active transports.
790 *
791 * This code produces the wrong ordering whenever jiffies
792 * rolls over, but we still get usable transports, so we don't
793 * worry about it.
794 */
795 first = NULL; second = NULL;
796
797 list_for_each(pos, &asoc->peer.transport_addr_list) {
798 t = list_entry(pos, struct sctp_transport, transports);
799
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700800 if ((t->state == SCTP_INACTIVE) ||
801 (t->state == SCTP_UNCONFIRMED))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700802 continue;
803 if (!first || t->last_time_heard > first->last_time_heard) {
804 second = first;
805 first = t;
806 }
807 if (!second || t->last_time_heard > second->last_time_heard)
808 second = t;
809 }
810
811 /* RFC 2960 6.4 Multi-Homed SCTP Endpoints
812 *
813 * By default, an endpoint should always transmit to the
814 * primary path, unless the SCTP user explicitly specifies the
815 * destination transport address (and possibly source
816 * transport address) to use.
817 *
818 * [If the primary is active but not most recent, bump the most
819 * recently used transport.]
820 */
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700821 if (((asoc->peer.primary_path->state == SCTP_ACTIVE) ||
822 (asoc->peer.primary_path->state == SCTP_UNKNOWN)) &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700823 first != asoc->peer.primary_path) {
824 second = first;
825 first = asoc->peer.primary_path;
826 }
827
828 /* If we failed to find a usable transport, just camp on the
829 * primary, even if it is inactive.
830 */
831 if (!first) {
832 first = asoc->peer.primary_path;
833 second = asoc->peer.primary_path;
834 }
835
836 /* Set the active and retran transports. */
837 asoc->peer.active_path = first;
838 asoc->peer.retran_path = second;
839}
840
841/* Hold a reference to an association. */
842void sctp_association_hold(struct sctp_association *asoc)
843{
844 atomic_inc(&asoc->base.refcnt);
845}
846
847/* Release a reference to an association and cleanup
848 * if there are no more references.
849 */
850void sctp_association_put(struct sctp_association *asoc)
851{
852 if (atomic_dec_and_test(&asoc->base.refcnt))
853 sctp_association_destroy(asoc);
854}
855
856/* Allocate the next TSN, Transmission Sequence Number, for the given
857 * association.
858 */
859__u32 sctp_association_get_next_tsn(struct sctp_association *asoc)
860{
861 /* From Section 1.6 Serial Number Arithmetic:
862 * Transmission Sequence Numbers wrap around when they reach
863 * 2**32 - 1. That is, the next TSN a DATA chunk MUST use
864 * after transmitting TSN = 2*32 - 1 is TSN = 0.
865 */
866 __u32 retval = asoc->next_tsn;
867 asoc->next_tsn++;
868 asoc->unack_data++;
869
870 return retval;
871}
872
873/* Compare two addresses to see if they match. Wildcard addresses
874 * only match themselves.
875 */
876int sctp_cmp_addr_exact(const union sctp_addr *ss1,
877 const union sctp_addr *ss2)
878{
879 struct sctp_af *af;
880
881 af = sctp_get_af_specific(ss1->sa.sa_family);
882 if (unlikely(!af))
883 return 0;
884
885 return af->cmp_addr(ss1, ss2);
886}
887
888/* Return an ecne chunk to get prepended to a packet.
889 * Note: We are sly and return a shared, prealloced chunk. FIXME:
890 * No we don't, but we could/should.
891 */
892struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc)
893{
894 struct sctp_chunk *chunk;
895
896 /* Send ECNE if needed.
897 * Not being able to allocate a chunk here is not deadly.
898 */
899 if (asoc->need_ecne)
900 chunk = sctp_make_ecne(asoc, asoc->last_ecne_tsn);
901 else
902 chunk = NULL;
903
904 return chunk;
905}
906
907/*
908 * Find which transport this TSN was sent on.
909 */
910struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *asoc,
911 __u32 tsn)
912{
913 struct sctp_transport *active;
914 struct sctp_transport *match;
915 struct list_head *entry, *pos;
916 struct sctp_transport *transport;
917 struct sctp_chunk *chunk;
Al Virodbc16db2006-11-20 17:01:42 -0800918 __be32 key = htonl(tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700919
920 match = NULL;
921
922 /*
923 * FIXME: In general, find a more efficient data structure for
924 * searching.
925 */
926
927 /*
928 * The general strategy is to search each transport's transmitted
929 * list. Return which transport this TSN lives on.
930 *
931 * Let's be hopeful and check the active_path first.
932 * Another optimization would be to know if there is only one
933 * outbound path and not have to look for the TSN at all.
934 *
935 */
936
937 active = asoc->peer.active_path;
938
939 list_for_each(entry, &active->transmitted) {
940 chunk = list_entry(entry, struct sctp_chunk, transmitted_list);
941
942 if (key == chunk->subh.data_hdr->tsn) {
943 match = active;
944 goto out;
945 }
946 }
947
948 /* If not found, go search all the other transports. */
949 list_for_each(pos, &asoc->peer.transport_addr_list) {
950 transport = list_entry(pos, struct sctp_transport, transports);
951
952 if (transport == active)
953 break;
954 list_for_each(entry, &transport->transmitted) {
955 chunk = list_entry(entry, struct sctp_chunk,
956 transmitted_list);
957 if (key == chunk->subh.data_hdr->tsn) {
958 match = transport;
959 goto out;
960 }
961 }
962 }
963out:
964 return match;
965}
966
967/* Is this the association we are looking for? */
968struct sctp_transport *sctp_assoc_is_match(struct sctp_association *asoc,
969 const union sctp_addr *laddr,
970 const union sctp_addr *paddr)
971{
972 struct sctp_transport *transport;
973
Al Viroe2fcced2006-11-20 17:08:41 -0800974 if ((htons(asoc->base.bind_addr.port) == laddr->v4.sin_port) &&
975 (htons(asoc->peer.port) == paddr->v4.sin_port)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700976 transport = sctp_assoc_lookup_paddr(asoc, paddr);
977 if (!transport)
978 goto out;
979
980 if (sctp_bind_addr_match(&asoc->base.bind_addr, laddr,
981 sctp_sk(asoc->base.sk)))
982 goto out;
983 }
984 transport = NULL;
985
986out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700987 return transport;
988}
989
990/* Do delayed input processing. This is scheduled by sctp_rcv(). */
David Howellsc4028952006-11-22 14:57:56 +0000991static void sctp_assoc_bh_rcv(struct work_struct *work)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700992{
David Howellsc4028952006-11-22 14:57:56 +0000993 struct sctp_association *asoc =
994 container_of(work, struct sctp_association,
995 base.inqueue.immediate);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700996 struct sctp_endpoint *ep;
997 struct sctp_chunk *chunk;
998 struct sock *sk;
999 struct sctp_inq *inqueue;
1000 int state;
1001 sctp_subtype_t subtype;
1002 int error = 0;
1003
1004 /* The association should be held so we should be safe. */
1005 ep = asoc->ep;
1006 sk = asoc->base.sk;
1007
1008 inqueue = &asoc->base.inqueue;
1009 sctp_association_hold(asoc);
1010 while (NULL != (chunk = sctp_inq_pop(inqueue))) {
1011 state = asoc->state;
1012 subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type);
1013
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07001014 /* SCTP-AUTH, Section 6.3:
1015 * The receiver has a list of chunk types which it expects
1016 * to be received only after an AUTH-chunk. This list has
1017 * been sent to the peer during the association setup. It
1018 * MUST silently discard these chunks if they are not placed
1019 * after an AUTH chunk in the packet.
1020 */
1021 if (sctp_auth_recv_cid(subtype.chunk, asoc) && !chunk->auth)
1022 continue;
1023
Linus Torvalds1da177e2005-04-16 15:20:36 -07001024 /* Remember where the last DATA chunk came from so we
1025 * know where to send the SACK.
1026 */
1027 if (sctp_chunk_is_data(chunk))
1028 asoc->peer.last_data_from = chunk->transport;
1029 else
1030 SCTP_INC_STATS(SCTP_MIB_INCTRLCHUNKS);
1031
1032 if (chunk->transport)
1033 chunk->transport->last_time_heard = jiffies;
1034
1035 /* Run through the state machine. */
1036 error = sctp_do_sm(SCTP_EVENT_T_CHUNK, subtype,
1037 state, ep, asoc, chunk, GFP_ATOMIC);
1038
1039 /* Check to see if the association is freed in response to
1040 * the incoming chunk. If so, get out of the while loop.
1041 */
1042 if (asoc->base.dead)
1043 break;
1044
1045 /* If there is an error on chunk, discard this packet. */
1046 if (error && chunk)
1047 chunk->pdiscard = 1;
1048 }
1049 sctp_association_put(asoc);
1050}
1051
1052/* This routine moves an association from its old sk to a new sk. */
1053void sctp_assoc_migrate(struct sctp_association *assoc, struct sock *newsk)
1054{
1055 struct sctp_sock *newsp = sctp_sk(newsk);
1056 struct sock *oldsk = assoc->base.sk;
1057
1058 /* Delete the association from the old endpoint's list of
1059 * associations.
1060 */
1061 list_del_init(&assoc->asocs);
1062
1063 /* Decrement the backlog value for a TCP-style socket. */
1064 if (sctp_style(oldsk, TCP))
1065 oldsk->sk_ack_backlog--;
1066
1067 /* Release references to the old endpoint and the sock. */
1068 sctp_endpoint_put(assoc->ep);
1069 sock_put(assoc->base.sk);
1070
1071 /* Get a reference to the new endpoint. */
1072 assoc->ep = newsp->ep;
1073 sctp_endpoint_hold(assoc->ep);
1074
1075 /* Get a reference to the new sock. */
1076 assoc->base.sk = newsk;
1077 sock_hold(assoc->base.sk);
1078
1079 /* Add the association to the new endpoint's list of associations. */
1080 sctp_endpoint_add_asoc(newsp->ep, assoc);
1081}
1082
1083/* Update an association (possibly from unexpected COOKIE-ECHO processing). */
1084void sctp_assoc_update(struct sctp_association *asoc,
1085 struct sctp_association *new)
1086{
1087 struct sctp_transport *trans;
1088 struct list_head *pos, *temp;
1089
1090 /* Copy in new parameters of peer. */
1091 asoc->c = new->c;
1092 asoc->peer.rwnd = new->peer.rwnd;
1093 asoc->peer.sack_needed = new->peer.sack_needed;
1094 asoc->peer.i = new->peer.i;
1095 sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_SIZE,
1096 asoc->peer.i.initial_tsn);
1097
1098 /* Remove any peer addresses not present in the new association. */
1099 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
1100 trans = list_entry(pos, struct sctp_transport, transports);
1101 if (!sctp_assoc_lookup_paddr(new, &trans->ipaddr))
1102 sctp_assoc_del_peer(asoc, &trans->ipaddr);
Vlad Yasevich749bf922007-03-19 17:02:30 -07001103
1104 if (asoc->state >= SCTP_STATE_ESTABLISHED)
1105 sctp_transport_reset(trans);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001106 }
1107
1108 /* If the case is A (association restart), use
1109 * initial_tsn as next_tsn. If the case is B, use
1110 * current next_tsn in case data sent to peer
1111 * has been discarded and needs retransmission.
1112 */
1113 if (asoc->state >= SCTP_STATE_ESTABLISHED) {
1114 asoc->next_tsn = new->next_tsn;
1115 asoc->ctsn_ack_point = new->ctsn_ack_point;
1116 asoc->adv_peer_ack_point = new->adv_peer_ack_point;
1117
1118 /* Reinitialize SSN for both local streams
1119 * and peer's streams.
1120 */
1121 sctp_ssnmap_clear(asoc->ssnmap);
1122
Vlad Yasevich0b58a812007-03-19 17:01:17 -07001123 /* Flush the ULP reassembly and ordered queue.
1124 * Any data there will now be stale and will
1125 * cause problems.
1126 */
1127 sctp_ulpq_flush(&asoc->ulpq);
1128
Vlad Yasevich749bf922007-03-19 17:02:30 -07001129 /* reset the overall association error count so
1130 * that the restarted association doesn't get torn
1131 * down on the next retransmission timer.
1132 */
1133 asoc->overall_error_count = 0;
1134
Linus Torvalds1da177e2005-04-16 15:20:36 -07001135 } else {
1136 /* Add any peer addresses from the new association. */
1137 list_for_each(pos, &new->peer.transport_addr_list) {
1138 trans = list_entry(pos, struct sctp_transport,
1139 transports);
1140 if (!sctp_assoc_lookup_paddr(asoc, &trans->ipaddr))
1141 sctp_assoc_add_peer(asoc, &trans->ipaddr,
Sridhar Samudralaad8fec12006-07-21 14:48:50 -07001142 GFP_ATOMIC, trans->state);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001143 }
1144
1145 asoc->ctsn_ack_point = asoc->next_tsn - 1;
1146 asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
1147 if (!asoc->ssnmap) {
1148 /* Move the ssnmap. */
1149 asoc->ssnmap = new->ssnmap;
1150 new->ssnmap = NULL;
1151 }
Vlad Yasevich07d93962007-05-04 13:55:27 -07001152
1153 if (!asoc->assoc_id) {
1154 /* get a new association id since we don't have one
1155 * yet.
1156 */
1157 sctp_assoc_set_id(asoc, GFP_ATOMIC);
1158 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001159 }
Vlad Yasevicha29a5bd2007-09-16 19:31:35 -07001160
Vlad Yasevich730fc3d2007-09-16 19:32:11 -07001161 /* SCTP-AUTH: Save the peer parameters from the new assocaitions
1162 * and also move the association shared keys over
1163 */
1164 kfree(asoc->peer.peer_random);
1165 asoc->peer.peer_random = new->peer.peer_random;
1166 new->peer.peer_random = NULL;
1167
1168 kfree(asoc->peer.peer_chunks);
1169 asoc->peer.peer_chunks = new->peer.peer_chunks;
1170 new->peer.peer_chunks = NULL;
1171
1172 kfree(asoc->peer.peer_hmacs);
1173 asoc->peer.peer_hmacs = new->peer.peer_hmacs;
1174 new->peer.peer_hmacs = NULL;
1175
1176 sctp_auth_key_put(asoc->asoc_shared_key);
1177 sctp_auth_asoc_init_active_key(asoc, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001178}
1179
1180/* Update the retran path for sending a retransmitted packet.
1181 * Round-robin through the active transports, else round-robin
1182 * through the inactive transports as this is the next best thing
1183 * we can try.
1184 */
1185void sctp_assoc_update_retran_path(struct sctp_association *asoc)
1186{
1187 struct sctp_transport *t, *next;
1188 struct list_head *head = &asoc->peer.transport_addr_list;
1189 struct list_head *pos;
1190
1191 /* Find the next transport in a round-robin fashion. */
1192 t = asoc->peer.retran_path;
1193 pos = &t->transports;
1194 next = NULL;
1195
1196 while (1) {
1197 /* Skip the head. */
1198 if (pos->next == head)
1199 pos = head->next;
1200 else
1201 pos = pos->next;
1202
1203 t = list_entry(pos, struct sctp_transport, transports);
1204
1205 /* Try to find an active transport. */
1206
Sridhar Samudralaad8fec12006-07-21 14:48:50 -07001207 if ((t->state == SCTP_ACTIVE) ||
1208 (t->state == SCTP_UNKNOWN)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001209 break;
1210 } else {
1211 /* Keep track of the next transport in case
1212 * we don't find any active transport.
1213 */
1214 if (!next)
1215 next = t;
1216 }
1217
1218 /* We have exhausted the list, but didn't find any
1219 * other active transports. If so, use the next
1220 * transport.
1221 */
1222 if (t == asoc->peer.retran_path) {
1223 t = next;
1224 break;
1225 }
1226 }
1227
1228 asoc->peer.retran_path = t;
Frank Filz3f7a87d2005-06-20 13:14:57 -07001229
1230 SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_update_retran_path:association"
1231 " %p addr: ",
1232 " port: %d\n",
1233 asoc,
1234 (&t->ipaddr),
Al Virob3f5b3b2006-11-20 17:22:43 -08001235 ntohs(t->ipaddr.v4.sin_port));
Frank Filz3f7a87d2005-06-20 13:14:57 -07001236}
1237
1238/* Choose the transport for sending a INIT packet. */
1239struct sctp_transport *sctp_assoc_choose_init_transport(
1240 struct sctp_association *asoc)
1241{
1242 struct sctp_transport *t;
1243
1244 /* Use the retran path. If the last INIT was sent over the
1245 * retran path, update the retran path and use it.
1246 */
1247 if (!asoc->init_last_sent_to) {
1248 t = asoc->peer.active_path;
1249 } else {
1250 if (asoc->init_last_sent_to == asoc->peer.retran_path)
1251 sctp_assoc_update_retran_path(asoc);
1252 t = asoc->peer.retran_path;
1253 }
1254
1255 SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_update_retran_path:association"
1256 " %p addr: ",
1257 " port: %d\n",
1258 asoc,
1259 (&t->ipaddr),
Al Virob3f5b3b2006-11-20 17:22:43 -08001260 ntohs(t->ipaddr.v4.sin_port));
Frank Filz3f7a87d2005-06-20 13:14:57 -07001261
1262 return t;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001263}
1264
1265/* Choose the transport for sending a SHUTDOWN packet. */
1266struct sctp_transport *sctp_assoc_choose_shutdown_transport(
1267 struct sctp_association *asoc)
1268{
1269 /* If this is the first time SHUTDOWN is sent, use the active path,
1270 * else use the retran path. If the last SHUTDOWN was sent over the
1271 * retran path, update the retran path and use it.
1272 */
1273 if (!asoc->shutdown_last_sent_to)
1274 return asoc->peer.active_path;
1275 else {
1276 if (asoc->shutdown_last_sent_to == asoc->peer.retran_path)
1277 sctp_assoc_update_retran_path(asoc);
1278 return asoc->peer.retran_path;
1279 }
1280
1281}
1282
1283/* Update the association's pmtu and frag_point by going through all the
1284 * transports. This routine is called when a transport's PMTU has changed.
1285 */
1286void sctp_assoc_sync_pmtu(struct sctp_association *asoc)
1287{
1288 struct sctp_transport *t;
1289 struct list_head *pos;
1290 __u32 pmtu = 0;
1291
1292 if (!asoc)
1293 return;
1294
1295 /* Get the lowest pmtu of all the transports. */
1296 list_for_each(pos, &asoc->peer.transport_addr_list) {
1297 t = list_entry(pos, struct sctp_transport, transports);
Vlad Yasevich8a479492007-06-07 14:21:05 -04001298 if (t->pmtu_pending && t->dst) {
1299 sctp_transport_update_pmtu(t, dst_mtu(t->dst));
1300 t->pmtu_pending = 0;
1301 }
Frank Filz52ccb8e2005-12-22 11:36:46 -08001302 if (!pmtu || (t->pathmtu < pmtu))
1303 pmtu = t->pathmtu;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001304 }
1305
1306 if (pmtu) {
1307 struct sctp_sock *sp = sctp_sk(asoc->base.sk);
Frank Filz52ccb8e2005-12-22 11:36:46 -08001308 asoc->pathmtu = pmtu;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001309 asoc->frag_point = sctp_frag_point(sp, pmtu);
1310 }
1311
1312 SCTP_DEBUG_PRINTK("%s: asoc:%p, pmtu:%d, frag_point:%d\n",
Frank Filz52ccb8e2005-12-22 11:36:46 -08001313 __FUNCTION__, asoc, asoc->pathmtu, asoc->frag_point);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001314}
1315
1316/* Should we send a SACK to update our peer? */
1317static inline int sctp_peer_needs_update(struct sctp_association *asoc)
1318{
1319 switch (asoc->state) {
1320 case SCTP_STATE_ESTABLISHED:
1321 case SCTP_STATE_SHUTDOWN_PENDING:
1322 case SCTP_STATE_SHUTDOWN_RECEIVED:
1323 case SCTP_STATE_SHUTDOWN_SENT:
1324 if ((asoc->rwnd > asoc->a_rwnd) &&
1325 ((asoc->rwnd - asoc->a_rwnd) >=
Frank Filz52ccb8e2005-12-22 11:36:46 -08001326 min_t(__u32, (asoc->base.sk->sk_rcvbuf >> 1), asoc->pathmtu)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001327 return 1;
1328 break;
1329 default:
1330 break;
1331 }
1332 return 0;
1333}
1334
1335/* Increase asoc's rwnd by len and send any window update SACK if needed. */
1336void sctp_assoc_rwnd_increase(struct sctp_association *asoc, unsigned len)
1337{
1338 struct sctp_chunk *sack;
1339 struct timer_list *timer;
1340
1341 if (asoc->rwnd_over) {
1342 if (asoc->rwnd_over >= len) {
1343 asoc->rwnd_over -= len;
1344 } else {
1345 asoc->rwnd += (len - asoc->rwnd_over);
1346 asoc->rwnd_over = 0;
1347 }
1348 } else {
1349 asoc->rwnd += len;
1350 }
1351
1352 SCTP_DEBUG_PRINTK("%s: asoc %p rwnd increased by %d to (%u, %u) "
1353 "- %u\n", __FUNCTION__, asoc, len, asoc->rwnd,
1354 asoc->rwnd_over, asoc->a_rwnd);
1355
1356 /* Send a window update SACK if the rwnd has increased by at least the
1357 * minimum of the association's PMTU and half of the receive buffer.
1358 * The algorithm used is similar to the one described in
1359 * Section 4.2.3.3 of RFC 1122.
1360 */
1361 if (sctp_peer_needs_update(asoc)) {
1362 asoc->a_rwnd = asoc->rwnd;
1363 SCTP_DEBUG_PRINTK("%s: Sending window update SACK- asoc: %p "
1364 "rwnd: %u a_rwnd: %u\n", __FUNCTION__,
1365 asoc, asoc->rwnd, asoc->a_rwnd);
1366 sack = sctp_make_sack(asoc);
1367 if (!sack)
1368 return;
1369
1370 asoc->peer.sack_needed = 0;
1371
1372 sctp_outq_tail(&asoc->outqueue, sack);
1373
1374 /* Stop the SACK timer. */
1375 timer = &asoc->timers[SCTP_EVENT_TIMEOUT_SACK];
1376 if (timer_pending(timer) && del_timer(timer))
1377 sctp_association_put(asoc);
1378 }
1379}
1380
1381/* Decrease asoc's rwnd by len. */
1382void sctp_assoc_rwnd_decrease(struct sctp_association *asoc, unsigned len)
1383{
1384 SCTP_ASSERT(asoc->rwnd, "rwnd zero", return);
1385 SCTP_ASSERT(!asoc->rwnd_over, "rwnd_over not zero", return);
1386 if (asoc->rwnd >= len) {
1387 asoc->rwnd -= len;
1388 } else {
1389 asoc->rwnd_over = len - asoc->rwnd;
1390 asoc->rwnd = 0;
1391 }
1392 SCTP_DEBUG_PRINTK("%s: asoc %p rwnd decreased by %d to (%u, %u)\n",
1393 __FUNCTION__, asoc, len, asoc->rwnd,
1394 asoc->rwnd_over);
1395}
1396
1397/* Build the bind address list for the association based on info from the
1398 * local endpoint and the remote peer.
1399 */
Alexey Dobriyan3182cd842005-07-11 20:57:47 -07001400int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
Al Virodd0fc662005-10-07 07:46:04 +01001401 gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001402{
1403 sctp_scope_t scope;
1404 int flags;
1405
1406 /* Use scoping rules to determine the subset of addresses from
1407 * the endpoint.
1408 */
1409 scope = sctp_scope(&asoc->peer.active_path->ipaddr);
1410 flags = (PF_INET6 == asoc->base.sk->sk_family) ? SCTP_ADDR6_ALLOWED : 0;
1411 if (asoc->peer.ipv4_address)
1412 flags |= SCTP_ADDR4_PEERSUPP;
1413 if (asoc->peer.ipv6_address)
1414 flags |= SCTP_ADDR6_PEERSUPP;
1415
1416 return sctp_bind_addr_copy(&asoc->base.bind_addr,
1417 &asoc->ep->base.bind_addr,
1418 scope, gfp, flags);
1419}
1420
1421/* Build the association's bind address list from the cookie. */
1422int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *asoc,
Alexey Dobriyan3182cd842005-07-11 20:57:47 -07001423 struct sctp_cookie *cookie,
Al Virodd0fc662005-10-07 07:46:04 +01001424 gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001425{
1426 int var_size2 = ntohs(cookie->peer_init->chunk_hdr.length);
1427 int var_size3 = cookie->raw_addr_list_len;
1428 __u8 *raw = (__u8 *)cookie->peer_init + var_size2;
1429
1430 return sctp_raw_to_bind_addrs(&asoc->base.bind_addr, raw, var_size3,
1431 asoc->ep->base.bind_addr.port, gfp);
1432}
1433
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001434/* Lookup laddr in the bind address list of an association. */
1435int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001436 const union sctp_addr *laddr)
1437{
Vlad Yasevich559cf712007-09-16 16:03:28 -07001438 int found = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001439
Linus Torvalds1da177e2005-04-16 15:20:36 -07001440 if ((asoc->base.bind_addr.port == ntohs(laddr->v4.sin_port)) &&
1441 sctp_bind_addr_match(&asoc->base.bind_addr, laddr,
Vlad Yasevich559cf712007-09-16 16:03:28 -07001442 sctp_sk(asoc->base.sk)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001443 found = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001444
Linus Torvalds1da177e2005-04-16 15:20:36 -07001445 return found;
1446}
Vlad Yasevich07d93962007-05-04 13:55:27 -07001447
1448/* Set an association id for a given association */
1449int sctp_assoc_set_id(struct sctp_association *asoc, gfp_t gfp)
1450{
1451 int assoc_id;
1452 int error = 0;
1453retry:
1454 if (unlikely(!idr_pre_get(&sctp_assocs_id, gfp)))
1455 return -ENOMEM;
1456
1457 spin_lock_bh(&sctp_assocs_id_lock);
1458 error = idr_get_new_above(&sctp_assocs_id, (void *)asoc,
1459 1, &assoc_id);
1460 spin_unlock_bh(&sctp_assocs_id_lock);
1461 if (error == -EAGAIN)
1462 goto retry;
1463 else if (error)
1464 return error;
1465
1466 asoc->assoc_id = (sctp_assoc_t) assoc_id;
1467 return error;
1468}