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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;
77
78 /* Retrieve the SCTP per socket area. */
79 sp = sctp_sk((struct sock *)sk);
80
81 /* Init all variables to a known value. */
82 memset(asoc, 0, sizeof(struct sctp_association));
83
84 /* Discarding const is appropriate here. */
85 asoc->ep = (struct sctp_endpoint *)ep;
86 sctp_endpoint_hold(asoc->ep);
87
88 /* Hold the sock. */
89 asoc->base.sk = (struct sock *)sk;
90 sock_hold(asoc->base.sk);
91
92 /* Initialize the common base substructure. */
93 asoc->base.type = SCTP_EP_TYPE_ASSOCIATION;
94
95 /* Initialize the object handling fields. */
96 atomic_set(&asoc->base.refcnt, 1);
97 asoc->base.dead = 0;
98 asoc->base.malloced = 0;
99
100 /* Initialize the bind addr area. */
101 sctp_bind_addr_init(&asoc->base.bind_addr, ep->base.bind_addr.port);
102 rwlock_init(&asoc->base.addr_lock);
103
104 asoc->state = SCTP_STATE_CLOSED;
105
106 /* Set these values from the socket values, a conversion between
107 * millsecons to seconds/microseconds must also be done.
108 */
109 asoc->cookie_life.tv_sec = sp->assocparams.sasoc_cookie_life / 1000;
110 asoc->cookie_life.tv_usec = (sp->assocparams.sasoc_cookie_life % 1000)
111 * 1000;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112 asoc->frag_point = 0;
113
114 /* Set the association max_retrans and RTO values from the
115 * socket values.
116 */
117 asoc->max_retrans = sp->assocparams.sasoc_asocmaxrxt;
118 asoc->rto_initial = msecs_to_jiffies(sp->rtoinfo.srto_initial);
119 asoc->rto_max = msecs_to_jiffies(sp->rtoinfo.srto_max);
120 asoc->rto_min = msecs_to_jiffies(sp->rtoinfo.srto_min);
121
122 asoc->overall_error_count = 0;
123
Frank Filz52ccb8e2005-12-22 11:36:46 -0800124 /* Initialize the association's heartbeat interval based on the
125 * sock configured value.
126 */
127 asoc->hbinterval = msecs_to_jiffies(sp->hbinterval);
128
129 /* Initialize path max retrans value. */
130 asoc->pathmaxrxt = sp->pathmaxrxt;
131
132 /* Initialize default path MTU. */
133 asoc->pathmtu = sp->pathmtu;
134
135 /* Set association default SACK delay */
136 asoc->sackdelay = msecs_to_jiffies(sp->sackdelay);
137
138 /* Set the association default flags controlling
139 * Heartbeat, SACK delay, and Path MTU Discovery.
140 */
141 asoc->param_flags = sp->param_flags;
142
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143 /* Initialize the maximum mumber of new data packets that can be sent
144 * in a burst.
145 */
Vlad Yasevich70331572007-03-23 11:34:36 -0700146 asoc->max_burst = sp->max_burst;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147
Vladislav Yasevich1e7d3d92005-11-11 16:06:16 -0800148 /* initialize association timers */
149 asoc->timeouts[SCTP_EVENT_TIMEOUT_NONE] = 0;
150 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] = asoc->rto_initial;
151 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] = asoc->rto_initial;
152 asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = asoc->rto_initial;
153 asoc->timeouts[SCTP_EVENT_TIMEOUT_T3_RTX] = 0;
154 asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = 0;
155
156 /* sctpimpguide Section 2.12.2
157 * If the 'T5-shutdown-guard' timer is used, it SHOULD be set to the
158 * recommended value of 5 times 'RTO.Max'.
159 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900160 asoc->timeouts[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD]
Vladislav Yasevich1e7d3d92005-11-11 16:06:16 -0800161 = 5 * asoc->rto_max;
162
163 asoc->timeouts[SCTP_EVENT_TIMEOUT_HEARTBEAT] = 0;
Frank Filz52ccb8e2005-12-22 11:36:46 -0800164 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] = asoc->sackdelay;
Vladislav Yasevich1e7d3d92005-11-11 16:06:16 -0800165 asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE] =
166 sp->autoclose * HZ;
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900167
Vladislav Yasevich1e7d3d92005-11-11 16:06:16 -0800168 /* Initilizes the timers */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169 for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170 init_timer(&asoc->timers[i]);
171 asoc->timers[i].function = sctp_timer_events[i];
172 asoc->timers[i].data = (unsigned long) asoc;
173 }
174
175 /* Pull default initialization values from the sock options.
176 * Note: This assumes that the values have already been
177 * validated in the sock.
178 */
179 asoc->c.sinit_max_instreams = sp->initmsg.sinit_max_instreams;
180 asoc->c.sinit_num_ostreams = sp->initmsg.sinit_num_ostreams;
181 asoc->max_init_attempts = sp->initmsg.sinit_max_attempts;
182
183 asoc->max_init_timeo =
184 msecs_to_jiffies(sp->initmsg.sinit_max_init_timeo);
185
186 /* Allocate storage for the ssnmap after the inbound and outbound
187 * streams have been negotiated during Init.
188 */
189 asoc->ssnmap = NULL;
190
191 /* Set the local window size for receive.
192 * This is also the rcvbuf space per association.
193 * RFC 6 - A SCTP receiver MUST be able to receive a minimum of
194 * 1500 bytes in one SCTP packet.
195 */
Neil Horman049b3ff2005-11-11 16:08:24 -0800196 if ((sk->sk_rcvbuf/2) < SCTP_DEFAULT_MINWINDOW)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197 asoc->rwnd = SCTP_DEFAULT_MINWINDOW;
198 else
Neil Horman049b3ff2005-11-11 16:08:24 -0800199 asoc->rwnd = sk->sk_rcvbuf/2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200
201 asoc->a_rwnd = asoc->rwnd;
202
203 asoc->rwnd_over = 0;
204
205 /* Use my own max window until I learn something better. */
206 asoc->peer.rwnd = SCTP_DEFAULT_MAXWINDOW;
207
208 /* Set the sndbuf size for transmit. */
209 asoc->sndbuf_used = 0;
210
Neil Horman049b3ff2005-11-11 16:08:24 -0800211 /* Initialize the receive memory counter */
212 atomic_set(&asoc->rmem_alloc, 0);
213
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214 init_waitqueue_head(&asoc->wait);
215
216 asoc->c.my_vtag = sctp_generate_tag(ep);
217 asoc->peer.i.init_tag = 0; /* INIT needs a vtag of 0. */
218 asoc->c.peer_vtag = 0;
219 asoc->c.my_ttag = 0;
220 asoc->c.peer_ttag = 0;
221 asoc->c.my_port = ep->base.bind_addr.port;
222
223 asoc->c.initial_tsn = sctp_generate_tsn(ep);
224
225 asoc->next_tsn = asoc->c.initial_tsn;
226
227 asoc->ctsn_ack_point = asoc->next_tsn - 1;
228 asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
229 asoc->highest_sacked = asoc->ctsn_ack_point;
230 asoc->last_cwr_tsn = asoc->ctsn_ack_point;
231 asoc->unack_data = 0;
232
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233 /* ADDIP Section 4.1 Asconf Chunk Procedures
234 *
235 * When an endpoint has an ASCONF signaled change to be sent to the
236 * remote endpoint it should do the following:
237 * ...
238 * A2) a serial number should be assigned to the chunk. The serial
239 * number SHOULD be a monotonically increasing number. The serial
240 * numbers SHOULD be initialized at the start of the
241 * association to the same value as the initial TSN.
242 */
243 asoc->addip_serial = asoc->c.initial_tsn;
244
David S. Miller79af02c2005-07-08 21:47:49 -0700245 INIT_LIST_HEAD(&asoc->addip_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246
247 /* Make an empty list of remote transport addresses. */
248 INIT_LIST_HEAD(&asoc->peer.transport_addr_list);
Frank Filz3f7a87d2005-06-20 13:14:57 -0700249 asoc->peer.transport_count = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250
251 /* RFC 2960 5.1 Normal Establishment of an Association
252 *
253 * After the reception of the first data chunk in an
254 * association the endpoint must immediately respond with a
255 * sack to acknowledge the data chunk. Subsequent
256 * acknowledgements should be done as described in Section
257 * 6.2.
258 *
259 * [We implement this by telling a new association that it
260 * already received one packet.]
261 */
262 asoc->peer.sack_needed = 1;
263
264 /* Assume that the peer recongizes ASCONF until reported otherwise
265 * via an ERROR chunk.
266 */
267 asoc->peer.asconf_capable = 1;
268
269 /* Create an input queue. */
270 sctp_inq_init(&asoc->base.inqueue);
David Howellsc4028952006-11-22 14:57:56 +0000271 sctp_inq_set_th_handler(&asoc->base.inqueue, sctp_assoc_bh_rcv);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272
273 /* Create an output queue. */
274 sctp_outq_init(asoc, &asoc->outqueue);
275
276 if (!sctp_ulpq_init(&asoc->ulpq, asoc))
277 goto fail_init;
278
279 /* Set up the tsn tracking. */
280 sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_SIZE, 0);
281
282 asoc->need_ecne = 0;
283
284 asoc->assoc_id = 0;
285
286 /* Assume that peer would support both address types unless we are
287 * told otherwise.
288 */
289 asoc->peer.ipv4_address = 1;
290 asoc->peer.ipv6_address = 1;
291 INIT_LIST_HEAD(&asoc->asocs);
292
293 asoc->autoclose = sp->autoclose;
294
295 asoc->default_stream = sp->default_stream;
296 asoc->default_ppid = sp->default_ppid;
297 asoc->default_flags = sp->default_flags;
298 asoc->default_context = sp->default_context;
299 asoc->default_timetolive = sp->default_timetolive;
Ivan Skytte Jorgensen6ab792f2006-12-13 16:34:22 -0800300 asoc->default_rcv_context = sp->default_rcv_context;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301
302 return asoc;
303
304fail_init:
305 sctp_endpoint_put(asoc->ep);
306 sock_put(asoc->base.sk);
307 return NULL;
308}
309
310/* Allocate and initialize a new association */
311struct sctp_association *sctp_association_new(const struct sctp_endpoint *ep,
312 const struct sock *sk,
Alexey Dobriyan3182cd842005-07-11 20:57:47 -0700313 sctp_scope_t scope,
Al Virodd0fc662005-10-07 07:46:04 +0100314 gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700315{
316 struct sctp_association *asoc;
317
318 asoc = t_new(struct sctp_association, gfp);
319 if (!asoc)
320 goto fail;
321
322 if (!sctp_association_init(asoc, ep, sk, scope, gfp))
323 goto fail_init;
324
325 asoc->base.malloced = 1;
326 SCTP_DBG_OBJCNT_INC(assoc);
Frank Filz3f7a87d2005-06-20 13:14:57 -0700327 SCTP_DEBUG_PRINTK("Created asoc %p\n", asoc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328
329 return asoc;
330
331fail_init:
332 kfree(asoc);
333fail:
334 return NULL;
335}
336
337/* Free this association if possible. There may still be users, so
338 * the actual deallocation may be delayed.
339 */
340void sctp_association_free(struct sctp_association *asoc)
341{
342 struct sock *sk = asoc->base.sk;
343 struct sctp_transport *transport;
344 struct list_head *pos, *temp;
345 int i;
346
Vlad Yasevichde76e692006-10-30 18:55:11 -0800347 /* Only real associations count against the endpoint, so
348 * don't bother for if this is a temporary association.
349 */
350 if (!asoc->temp) {
351 list_del(&asoc->asocs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352
Vlad Yasevichde76e692006-10-30 18:55:11 -0800353 /* Decrement the backlog value for a TCP-style listening
354 * socket.
355 */
356 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
357 sk->sk_ack_backlog--;
358 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359
360 /* Mark as dead, so other users can know this structure is
361 * going away.
362 */
363 asoc->base.dead = 1;
364
365 /* Dispose of any data lying around in the outqueue. */
366 sctp_outq_free(&asoc->outqueue);
367
368 /* Dispose of any pending messages for the upper layer. */
369 sctp_ulpq_free(&asoc->ulpq);
370
371 /* Dispose of any pending chunks on the inqueue. */
372 sctp_inq_free(&asoc->base.inqueue);
373
374 /* Free ssnmap storage. */
375 sctp_ssnmap_free(asoc->ssnmap);
376
377 /* Clean up the bound address list. */
378 sctp_bind_addr_free(&asoc->base.bind_addr);
379
380 /* Do we need to go through all of our timers and
381 * delete them? To be safe we will try to delete all, but we
382 * should be able to go through and make a guess based
383 * on our state.
384 */
385 for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i) {
386 if (timer_pending(&asoc->timers[i]) &&
387 del_timer(&asoc->timers[i]))
388 sctp_association_put(asoc);
389 }
390
391 /* Free peer's cached cookie. */
Jesper Juhla51482b2005-11-08 09:41:34 -0800392 kfree(asoc->peer.cookie);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393
394 /* Release the transport structures. */
395 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
396 transport = list_entry(pos, struct sctp_transport, transports);
397 list_del(pos);
398 sctp_transport_free(transport);
399 }
400
Frank Filz3f7a87d2005-06-20 13:14:57 -0700401 asoc->peer.transport_count = 0;
402
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403 /* Free any cached ASCONF_ACK chunk. */
404 if (asoc->addip_last_asconf_ack)
405 sctp_chunk_free(asoc->addip_last_asconf_ack);
406
407 /* Free any cached ASCONF chunk. */
408 if (asoc->addip_last_asconf)
409 sctp_chunk_free(asoc->addip_last_asconf);
410
411 sctp_association_put(asoc);
412}
413
414/* Cleanup and free up an association. */
415static void sctp_association_destroy(struct sctp_association *asoc)
416{
417 SCTP_ASSERT(asoc->base.dead, "Assoc is not dead", return);
418
419 sctp_endpoint_put(asoc->ep);
420 sock_put(asoc->base.sk);
421
422 if (asoc->assoc_id != 0) {
423 spin_lock_bh(&sctp_assocs_id_lock);
424 idr_remove(&sctp_assocs_id, asoc->assoc_id);
425 spin_unlock_bh(&sctp_assocs_id_lock);
426 }
427
Neil Horman049b3ff2005-11-11 16:08:24 -0800428 BUG_TRAP(!atomic_read(&asoc->rmem_alloc));
429
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430 if (asoc->base.malloced) {
431 kfree(asoc);
432 SCTP_DBG_OBJCNT_DEC(assoc);
433 }
434}
435
436/* Change the primary destination address for the peer. */
437void sctp_assoc_set_primary(struct sctp_association *asoc,
438 struct sctp_transport *transport)
439{
440 asoc->peer.primary_path = transport;
441
442 /* Set a default msg_name for events. */
443 memcpy(&asoc->peer.primary_addr, &transport->ipaddr,
444 sizeof(union sctp_addr));
445
446 /* If the primary path is changing, assume that the
447 * user wants to use this new path.
448 */
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700449 if ((transport->state == SCTP_ACTIVE) ||
450 (transport->state == SCTP_UNKNOWN))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700451 asoc->peer.active_path = transport;
452
453 /*
454 * SFR-CACC algorithm:
455 * Upon the receipt of a request to change the primary
456 * destination address, on the data structure for the new
457 * primary destination, the sender MUST do the following:
458 *
459 * 1) If CHANGEOVER_ACTIVE is set, then there was a switch
460 * to this destination address earlier. The sender MUST set
461 * CYCLING_CHANGEOVER to indicate that this switch is a
462 * double switch to the same destination address.
463 */
464 if (transport->cacc.changeover_active)
465 transport->cacc.cycling_changeover = 1;
466
467 /* 2) The sender MUST set CHANGEOVER_ACTIVE to indicate that
468 * a changeover has occurred.
469 */
470 transport->cacc.changeover_active = 1;
471
472 /* 3) The sender MUST store the next TSN to be sent in
473 * next_tsn_at_change.
474 */
475 transport->cacc.next_tsn_at_change = asoc->next_tsn;
476}
477
Frank Filz3f7a87d2005-06-20 13:14:57 -0700478/* Remove a transport from an association. */
479void sctp_assoc_rm_peer(struct sctp_association *asoc,
480 struct sctp_transport *peer)
481{
482 struct list_head *pos;
483 struct sctp_transport *transport;
484
485 SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_rm_peer:association %p addr: ",
486 " port: %d\n",
487 asoc,
488 (&peer->ipaddr),
Al Virob3f5b3b2006-11-20 17:22:43 -0800489 ntohs(peer->ipaddr.v4.sin_port));
Frank Filz3f7a87d2005-06-20 13:14:57 -0700490
491 /* If we are to remove the current retran_path, update it
492 * to the next peer before removing this peer from the list.
493 */
494 if (asoc->peer.retran_path == peer)
495 sctp_assoc_update_retran_path(asoc);
496
497 /* Remove this peer from the list. */
498 list_del(&peer->transports);
499
500 /* Get the first transport of asoc. */
501 pos = asoc->peer.transport_addr_list.next;
502 transport = list_entry(pos, struct sctp_transport, transports);
503
504 /* Update any entries that match the peer to be deleted. */
505 if (asoc->peer.primary_path == peer)
506 sctp_assoc_set_primary(asoc, transport);
507 if (asoc->peer.active_path == peer)
508 asoc->peer.active_path = transport;
509 if (asoc->peer.last_data_from == peer)
510 asoc->peer.last_data_from = transport;
511
512 /* If we remove the transport an INIT was last sent to, set it to
513 * NULL. Combined with the update of the retran path above, this
514 * will cause the next INIT to be sent to the next available
515 * transport, maintaining the cycle.
516 */
517 if (asoc->init_last_sent_to == peer)
518 asoc->init_last_sent_to = NULL;
519
520 asoc->peer.transport_count--;
521
522 sctp_transport_free(peer);
523}
524
Linus Torvalds1da177e2005-04-16 15:20:36 -0700525/* Add a transport address to an association. */
526struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc,
527 const union sctp_addr *addr,
Al Virodd0fc662005-10-07 07:46:04 +0100528 const gfp_t gfp,
Frank Filz3f7a87d2005-06-20 13:14:57 -0700529 const int peer_state)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700530{
531 struct sctp_transport *peer;
532 struct sctp_sock *sp;
533 unsigned short port;
534
535 sp = sctp_sk(asoc->base.sk);
536
537 /* AF_INET and AF_INET6 share common port field. */
Al Viro4bdf4b52006-11-20 17:10:20 -0800538 port = ntohs(addr->v4.sin_port);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539
Frank Filz3f7a87d2005-06-20 13:14:57 -0700540 SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_add_peer:association %p addr: ",
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700541 " port: %d state:%d\n",
Frank Filz3f7a87d2005-06-20 13:14:57 -0700542 asoc,
543 addr,
Al Viro4bdf4b52006-11-20 17:10:20 -0800544 port,
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700545 peer_state);
Frank Filz3f7a87d2005-06-20 13:14:57 -0700546
Linus Torvalds1da177e2005-04-16 15:20:36 -0700547 /* Set the port if it has not been set yet. */
548 if (0 == asoc->peer.port)
549 asoc->peer.port = port;
550
551 /* Check to see if this is a duplicate. */
552 peer = sctp_assoc_lookup_paddr(asoc, addr);
Frank Filz3f7a87d2005-06-20 13:14:57 -0700553 if (peer) {
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700554 if (peer->state == SCTP_UNKNOWN) {
555 if (peer_state == SCTP_ACTIVE)
556 peer->state = SCTP_ACTIVE;
557 if (peer_state == SCTP_UNCONFIRMED)
558 peer->state = SCTP_UNCONFIRMED;
559 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700560 return peer;
Frank Filz3f7a87d2005-06-20 13:14:57 -0700561 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700562
563 peer = sctp_transport_new(addr, gfp);
564 if (!peer)
565 return NULL;
566
567 sctp_transport_set_owner(peer, asoc);
568
Frank Filz52ccb8e2005-12-22 11:36:46 -0800569 /* Initialize the peer's heartbeat interval based on the
570 * association configured value.
571 */
572 peer->hbinterval = asoc->hbinterval;
573
574 /* Set the path max_retrans. */
575 peer->pathmaxrxt = asoc->pathmaxrxt;
576
577 /* Initialize the peer's SACK delay timeout based on the
578 * association configured value.
579 */
580 peer->sackdelay = asoc->sackdelay;
581
582 /* Enable/disable heartbeat, SACK delay, and path MTU discovery
583 * based on association setting.
584 */
585 peer->param_flags = asoc->param_flags;
586
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587 /* Initialize the pmtu of the transport. */
Frank Filz52ccb8e2005-12-22 11:36:46 -0800588 if (peer->param_flags & SPP_PMTUD_ENABLE)
589 sctp_transport_pmtu(peer);
590 else if (asoc->pathmtu)
591 peer->pathmtu = asoc->pathmtu;
592 else
593 peer->pathmtu = SCTP_DEFAULT_MAXSEGMENT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700594
595 /* If this is the first transport addr on this association,
596 * initialize the association PMTU to the peer's PMTU.
597 * If not and the current association PMTU is higher than the new
598 * peer's PMTU, reset the association PMTU to the new peer's PMTU.
599 */
Frank Filz52ccb8e2005-12-22 11:36:46 -0800600 if (asoc->pathmtu)
601 asoc->pathmtu = min_t(int, peer->pathmtu, asoc->pathmtu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602 else
Frank Filz52ccb8e2005-12-22 11:36:46 -0800603 asoc->pathmtu = peer->pathmtu;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604
605 SCTP_DEBUG_PRINTK("sctp_assoc_add_peer:association %p PMTU set to "
Frank Filz52ccb8e2005-12-22 11:36:46 -0800606 "%d\n", asoc, asoc->pathmtu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607
Frank Filz52ccb8e2005-12-22 11:36:46 -0800608 asoc->frag_point = sctp_frag_point(sp, asoc->pathmtu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609
610 /* The asoc->peer.port might not be meaningful yet, but
611 * initialize the packet structure anyway.
612 */
613 sctp_packet_init(&peer->packet, peer, asoc->base.bind_addr.port,
614 asoc->peer.port);
615
616 /* 7.2.1 Slow-Start
617 *
618 * o The initial cwnd before DATA transmission or after a sufficiently
619 * long idle period MUST be set to
620 * min(4*MTU, max(2*MTU, 4380 bytes))
621 *
622 * o The initial value of ssthresh MAY be arbitrarily high
623 * (for example, implementations MAY use the size of the
624 * receiver advertised window).
625 */
Frank Filz52ccb8e2005-12-22 11:36:46 -0800626 peer->cwnd = min(4*asoc->pathmtu, max_t(__u32, 2*asoc->pathmtu, 4380));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627
628 /* At this point, we may not have the receiver's advertised window,
629 * so initialize ssthresh to the default value and it will be set
630 * later when we process the INIT.
631 */
632 peer->ssthresh = SCTP_DEFAULT_MAXWINDOW;
633
634 peer->partial_bytes_acked = 0;
635 peer->flight_size = 0;
636
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637 /* Set the transport's RTO.initial value */
638 peer->rto = asoc->rto_initial;
639
Frank Filz3f7a87d2005-06-20 13:14:57 -0700640 /* Set the peer's active state. */
641 peer->state = peer_state;
642
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643 /* Attach the remote transport to our asoc. */
644 list_add_tail(&peer->transports, &asoc->peer.transport_addr_list);
Frank Filz3f7a87d2005-06-20 13:14:57 -0700645 asoc->peer.transport_count++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700646
647 /* If we do not yet have a primary path, set one. */
648 if (!asoc->peer.primary_path) {
649 sctp_assoc_set_primary(asoc, peer);
650 asoc->peer.retran_path = peer;
651 }
652
Frank Filz3f7a87d2005-06-20 13:14:57 -0700653 if (asoc->peer.active_path == asoc->peer.retran_path) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654 asoc->peer.retran_path = peer;
Frank Filz3f7a87d2005-06-20 13:14:57 -0700655 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700656
657 return peer;
658}
659
660/* Delete a transport address from an association. */
661void sctp_assoc_del_peer(struct sctp_association *asoc,
662 const union sctp_addr *addr)
663{
664 struct list_head *pos;
665 struct list_head *temp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700666 struct sctp_transport *transport;
667
668 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
669 transport = list_entry(pos, struct sctp_transport, transports);
670 if (sctp_cmp_addr_exact(addr, &transport->ipaddr)) {
Frank Filz3f7a87d2005-06-20 13:14:57 -0700671 /* Do book keeping for removing the peer and free it. */
672 sctp_assoc_rm_peer(asoc, transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700673 break;
674 }
675 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676}
677
678/* Lookup a transport by address. */
679struct sctp_transport *sctp_assoc_lookup_paddr(
680 const struct sctp_association *asoc,
681 const union sctp_addr *address)
682{
683 struct sctp_transport *t;
684 struct list_head *pos;
685
686 /* Cycle through all transports searching for a peer address. */
687
688 list_for_each(pos, &asoc->peer.transport_addr_list) {
689 t = list_entry(pos, struct sctp_transport, transports);
690 if (sctp_cmp_addr_exact(address, &t->ipaddr))
691 return t;
692 }
693
694 return NULL;
695}
696
697/* Engage in transport control operations.
698 * Mark the transport up or down and send a notification to the user.
699 * Select and update the new active and retran paths.
700 */
701void sctp_assoc_control_transport(struct sctp_association *asoc,
702 struct sctp_transport *transport,
703 sctp_transport_cmd_t command,
704 sctp_sn_error_t error)
705{
706 struct sctp_transport *t = NULL;
707 struct sctp_transport *first;
708 struct sctp_transport *second;
709 struct sctp_ulpevent *event;
Al Viro0906e202006-11-20 17:03:01 -0800710 struct sockaddr_storage addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700711 struct list_head *pos;
712 int spc_state = 0;
713
714 /* Record the transition on the transport. */
715 switch (command) {
716 case SCTP_TRANSPORT_UP:
Vlad Yasevich1ae41142007-03-23 11:32:26 -0700717 /* If we are moving from UNCONFIRMED state due
718 * to heartbeat success, report the SCTP_ADDR_CONFIRMED
719 * state to the user, otherwise report SCTP_ADDR_AVAILABLE.
720 */
721 if (SCTP_UNCONFIRMED == transport->state &&
722 SCTP_HEARTBEAT_SUCCESS == error)
723 spc_state = SCTP_ADDR_CONFIRMED;
724 else
725 spc_state = SCTP_ADDR_AVAILABLE;
Frank Filz3f7a87d2005-06-20 13:14:57 -0700726 transport->state = SCTP_ACTIVE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700727 break;
728
729 case SCTP_TRANSPORT_DOWN:
Frank Filz3f7a87d2005-06-20 13:14:57 -0700730 transport->state = SCTP_INACTIVE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731 spc_state = SCTP_ADDR_UNREACHABLE;
732 break;
733
734 default:
735 return;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700736 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700737
738 /* Generate and send a SCTP_PEER_ADDR_CHANGE notification to the
739 * user.
740 */
Al Viro0906e202006-11-20 17:03:01 -0800741 memset(&addr, 0, sizeof(struct sockaddr_storage));
Al Viro8cec6b82006-11-20 17:23:01 -0800742 memcpy(&addr, &transport->ipaddr, transport->af_specific->sockaddr_len);
Al Viro0906e202006-11-20 17:03:01 -0800743 event = sctp_ulpevent_make_peer_addr_change(asoc, &addr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700744 0, spc_state, error, GFP_ATOMIC);
745 if (event)
746 sctp_ulpq_tail_event(&asoc->ulpq, event);
747
748 /* Select new active and retran paths. */
749
750 /* Look for the two most recently used active transports.
751 *
752 * This code produces the wrong ordering whenever jiffies
753 * rolls over, but we still get usable transports, so we don't
754 * worry about it.
755 */
756 first = NULL; second = NULL;
757
758 list_for_each(pos, &asoc->peer.transport_addr_list) {
759 t = list_entry(pos, struct sctp_transport, transports);
760
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700761 if ((t->state == SCTP_INACTIVE) ||
762 (t->state == SCTP_UNCONFIRMED))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763 continue;
764 if (!first || t->last_time_heard > first->last_time_heard) {
765 second = first;
766 first = t;
767 }
768 if (!second || t->last_time_heard > second->last_time_heard)
769 second = t;
770 }
771
772 /* RFC 2960 6.4 Multi-Homed SCTP Endpoints
773 *
774 * By default, an endpoint should always transmit to the
775 * primary path, unless the SCTP user explicitly specifies the
776 * destination transport address (and possibly source
777 * transport address) to use.
778 *
779 * [If the primary is active but not most recent, bump the most
780 * recently used transport.]
781 */
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700782 if (((asoc->peer.primary_path->state == SCTP_ACTIVE) ||
783 (asoc->peer.primary_path->state == SCTP_UNKNOWN)) &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700784 first != asoc->peer.primary_path) {
785 second = first;
786 first = asoc->peer.primary_path;
787 }
788
789 /* If we failed to find a usable transport, just camp on the
790 * primary, even if it is inactive.
791 */
792 if (!first) {
793 first = asoc->peer.primary_path;
794 second = asoc->peer.primary_path;
795 }
796
797 /* Set the active and retran transports. */
798 asoc->peer.active_path = first;
799 asoc->peer.retran_path = second;
800}
801
802/* Hold a reference to an association. */
803void sctp_association_hold(struct sctp_association *asoc)
804{
805 atomic_inc(&asoc->base.refcnt);
806}
807
808/* Release a reference to an association and cleanup
809 * if there are no more references.
810 */
811void sctp_association_put(struct sctp_association *asoc)
812{
813 if (atomic_dec_and_test(&asoc->base.refcnt))
814 sctp_association_destroy(asoc);
815}
816
817/* Allocate the next TSN, Transmission Sequence Number, for the given
818 * association.
819 */
820__u32 sctp_association_get_next_tsn(struct sctp_association *asoc)
821{
822 /* From Section 1.6 Serial Number Arithmetic:
823 * Transmission Sequence Numbers wrap around when they reach
824 * 2**32 - 1. That is, the next TSN a DATA chunk MUST use
825 * after transmitting TSN = 2*32 - 1 is TSN = 0.
826 */
827 __u32 retval = asoc->next_tsn;
828 asoc->next_tsn++;
829 asoc->unack_data++;
830
831 return retval;
832}
833
834/* Compare two addresses to see if they match. Wildcard addresses
835 * only match themselves.
836 */
837int sctp_cmp_addr_exact(const union sctp_addr *ss1,
838 const union sctp_addr *ss2)
839{
840 struct sctp_af *af;
841
842 af = sctp_get_af_specific(ss1->sa.sa_family);
843 if (unlikely(!af))
844 return 0;
845
846 return af->cmp_addr(ss1, ss2);
847}
848
849/* Return an ecne chunk to get prepended to a packet.
850 * Note: We are sly and return a shared, prealloced chunk. FIXME:
851 * No we don't, but we could/should.
852 */
853struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc)
854{
855 struct sctp_chunk *chunk;
856
857 /* Send ECNE if needed.
858 * Not being able to allocate a chunk here is not deadly.
859 */
860 if (asoc->need_ecne)
861 chunk = sctp_make_ecne(asoc, asoc->last_ecne_tsn);
862 else
863 chunk = NULL;
864
865 return chunk;
866}
867
868/*
869 * Find which transport this TSN was sent on.
870 */
871struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *asoc,
872 __u32 tsn)
873{
874 struct sctp_transport *active;
875 struct sctp_transport *match;
876 struct list_head *entry, *pos;
877 struct sctp_transport *transport;
878 struct sctp_chunk *chunk;
Al Virodbc16db2006-11-20 17:01:42 -0800879 __be32 key = htonl(tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700880
881 match = NULL;
882
883 /*
884 * FIXME: In general, find a more efficient data structure for
885 * searching.
886 */
887
888 /*
889 * The general strategy is to search each transport's transmitted
890 * list. Return which transport this TSN lives on.
891 *
892 * Let's be hopeful and check the active_path first.
893 * Another optimization would be to know if there is only one
894 * outbound path and not have to look for the TSN at all.
895 *
896 */
897
898 active = asoc->peer.active_path;
899
900 list_for_each(entry, &active->transmitted) {
901 chunk = list_entry(entry, struct sctp_chunk, transmitted_list);
902
903 if (key == chunk->subh.data_hdr->tsn) {
904 match = active;
905 goto out;
906 }
907 }
908
909 /* If not found, go search all the other transports. */
910 list_for_each(pos, &asoc->peer.transport_addr_list) {
911 transport = list_entry(pos, struct sctp_transport, transports);
912
913 if (transport == active)
914 break;
915 list_for_each(entry, &transport->transmitted) {
916 chunk = list_entry(entry, struct sctp_chunk,
917 transmitted_list);
918 if (key == chunk->subh.data_hdr->tsn) {
919 match = transport;
920 goto out;
921 }
922 }
923 }
924out:
925 return match;
926}
927
928/* Is this the association we are looking for? */
929struct sctp_transport *sctp_assoc_is_match(struct sctp_association *asoc,
930 const union sctp_addr *laddr,
931 const union sctp_addr *paddr)
932{
933 struct sctp_transport *transport;
934
935 sctp_read_lock(&asoc->base.addr_lock);
936
Al Viroe2fcced2006-11-20 17:08:41 -0800937 if ((htons(asoc->base.bind_addr.port) == laddr->v4.sin_port) &&
938 (htons(asoc->peer.port) == paddr->v4.sin_port)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700939 transport = sctp_assoc_lookup_paddr(asoc, paddr);
940 if (!transport)
941 goto out;
942
943 if (sctp_bind_addr_match(&asoc->base.bind_addr, laddr,
944 sctp_sk(asoc->base.sk)))
945 goto out;
946 }
947 transport = NULL;
948
949out:
950 sctp_read_unlock(&asoc->base.addr_lock);
951 return transport;
952}
953
954/* Do delayed input processing. This is scheduled by sctp_rcv(). */
David Howellsc4028952006-11-22 14:57:56 +0000955static void sctp_assoc_bh_rcv(struct work_struct *work)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700956{
David Howellsc4028952006-11-22 14:57:56 +0000957 struct sctp_association *asoc =
958 container_of(work, struct sctp_association,
959 base.inqueue.immediate);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700960 struct sctp_endpoint *ep;
961 struct sctp_chunk *chunk;
962 struct sock *sk;
963 struct sctp_inq *inqueue;
964 int state;
965 sctp_subtype_t subtype;
966 int error = 0;
967
968 /* The association should be held so we should be safe. */
969 ep = asoc->ep;
970 sk = asoc->base.sk;
971
972 inqueue = &asoc->base.inqueue;
973 sctp_association_hold(asoc);
974 while (NULL != (chunk = sctp_inq_pop(inqueue))) {
975 state = asoc->state;
976 subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type);
977
978 /* Remember where the last DATA chunk came from so we
979 * know where to send the SACK.
980 */
981 if (sctp_chunk_is_data(chunk))
982 asoc->peer.last_data_from = chunk->transport;
983 else
984 SCTP_INC_STATS(SCTP_MIB_INCTRLCHUNKS);
985
986 if (chunk->transport)
987 chunk->transport->last_time_heard = jiffies;
988
989 /* Run through the state machine. */
990 error = sctp_do_sm(SCTP_EVENT_T_CHUNK, subtype,
991 state, ep, asoc, chunk, GFP_ATOMIC);
992
993 /* Check to see if the association is freed in response to
994 * the incoming chunk. If so, get out of the while loop.
995 */
996 if (asoc->base.dead)
997 break;
998
999 /* If there is an error on chunk, discard this packet. */
1000 if (error && chunk)
1001 chunk->pdiscard = 1;
1002 }
1003 sctp_association_put(asoc);
1004}
1005
1006/* This routine moves an association from its old sk to a new sk. */
1007void sctp_assoc_migrate(struct sctp_association *assoc, struct sock *newsk)
1008{
1009 struct sctp_sock *newsp = sctp_sk(newsk);
1010 struct sock *oldsk = assoc->base.sk;
1011
1012 /* Delete the association from the old endpoint's list of
1013 * associations.
1014 */
1015 list_del_init(&assoc->asocs);
1016
1017 /* Decrement the backlog value for a TCP-style socket. */
1018 if (sctp_style(oldsk, TCP))
1019 oldsk->sk_ack_backlog--;
1020
1021 /* Release references to the old endpoint and the sock. */
1022 sctp_endpoint_put(assoc->ep);
1023 sock_put(assoc->base.sk);
1024
1025 /* Get a reference to the new endpoint. */
1026 assoc->ep = newsp->ep;
1027 sctp_endpoint_hold(assoc->ep);
1028
1029 /* Get a reference to the new sock. */
1030 assoc->base.sk = newsk;
1031 sock_hold(assoc->base.sk);
1032
1033 /* Add the association to the new endpoint's list of associations. */
1034 sctp_endpoint_add_asoc(newsp->ep, assoc);
1035}
1036
1037/* Update an association (possibly from unexpected COOKIE-ECHO processing). */
1038void sctp_assoc_update(struct sctp_association *asoc,
1039 struct sctp_association *new)
1040{
1041 struct sctp_transport *trans;
1042 struct list_head *pos, *temp;
1043
1044 /* Copy in new parameters of peer. */
1045 asoc->c = new->c;
1046 asoc->peer.rwnd = new->peer.rwnd;
1047 asoc->peer.sack_needed = new->peer.sack_needed;
1048 asoc->peer.i = new->peer.i;
1049 sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_SIZE,
1050 asoc->peer.i.initial_tsn);
1051
1052 /* Remove any peer addresses not present in the new association. */
1053 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
1054 trans = list_entry(pos, struct sctp_transport, transports);
1055 if (!sctp_assoc_lookup_paddr(new, &trans->ipaddr))
1056 sctp_assoc_del_peer(asoc, &trans->ipaddr);
Vlad Yasevich749bf922007-03-19 17:02:30 -07001057
1058 if (asoc->state >= SCTP_STATE_ESTABLISHED)
1059 sctp_transport_reset(trans);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001060 }
1061
1062 /* If the case is A (association restart), use
1063 * initial_tsn as next_tsn. If the case is B, use
1064 * current next_tsn in case data sent to peer
1065 * has been discarded and needs retransmission.
1066 */
1067 if (asoc->state >= SCTP_STATE_ESTABLISHED) {
1068 asoc->next_tsn = new->next_tsn;
1069 asoc->ctsn_ack_point = new->ctsn_ack_point;
1070 asoc->adv_peer_ack_point = new->adv_peer_ack_point;
1071
1072 /* Reinitialize SSN for both local streams
1073 * and peer's streams.
1074 */
1075 sctp_ssnmap_clear(asoc->ssnmap);
1076
Vlad Yasevich0b58a812007-03-19 17:01:17 -07001077 /* Flush the ULP reassembly and ordered queue.
1078 * Any data there will now be stale and will
1079 * cause problems.
1080 */
1081 sctp_ulpq_flush(&asoc->ulpq);
1082
Vlad Yasevich749bf922007-03-19 17:02:30 -07001083 /* reset the overall association error count so
1084 * that the restarted association doesn't get torn
1085 * down on the next retransmission timer.
1086 */
1087 asoc->overall_error_count = 0;
1088
Linus Torvalds1da177e2005-04-16 15:20:36 -07001089 } else {
1090 /* Add any peer addresses from the new association. */
1091 list_for_each(pos, &new->peer.transport_addr_list) {
1092 trans = list_entry(pos, struct sctp_transport,
1093 transports);
1094 if (!sctp_assoc_lookup_paddr(asoc, &trans->ipaddr))
1095 sctp_assoc_add_peer(asoc, &trans->ipaddr,
Sridhar Samudralaad8fec12006-07-21 14:48:50 -07001096 GFP_ATOMIC, trans->state);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001097 }
1098
1099 asoc->ctsn_ack_point = asoc->next_tsn - 1;
1100 asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
1101 if (!asoc->ssnmap) {
1102 /* Move the ssnmap. */
1103 asoc->ssnmap = new->ssnmap;
1104 new->ssnmap = NULL;
1105 }
1106 }
1107}
1108
1109/* Update the retran path for sending a retransmitted packet.
1110 * Round-robin through the active transports, else round-robin
1111 * through the inactive transports as this is the next best thing
1112 * we can try.
1113 */
1114void sctp_assoc_update_retran_path(struct sctp_association *asoc)
1115{
1116 struct sctp_transport *t, *next;
1117 struct list_head *head = &asoc->peer.transport_addr_list;
1118 struct list_head *pos;
1119
1120 /* Find the next transport in a round-robin fashion. */
1121 t = asoc->peer.retran_path;
1122 pos = &t->transports;
1123 next = NULL;
1124
1125 while (1) {
1126 /* Skip the head. */
1127 if (pos->next == head)
1128 pos = head->next;
1129 else
1130 pos = pos->next;
1131
1132 t = list_entry(pos, struct sctp_transport, transports);
1133
1134 /* Try to find an active transport. */
1135
Sridhar Samudralaad8fec12006-07-21 14:48:50 -07001136 if ((t->state == SCTP_ACTIVE) ||
1137 (t->state == SCTP_UNKNOWN)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001138 break;
1139 } else {
1140 /* Keep track of the next transport in case
1141 * we don't find any active transport.
1142 */
1143 if (!next)
1144 next = t;
1145 }
1146
1147 /* We have exhausted the list, but didn't find any
1148 * other active transports. If so, use the next
1149 * transport.
1150 */
1151 if (t == asoc->peer.retran_path) {
1152 t = next;
1153 break;
1154 }
1155 }
1156
1157 asoc->peer.retran_path = t;
Frank Filz3f7a87d2005-06-20 13:14:57 -07001158
1159 SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_update_retran_path:association"
1160 " %p addr: ",
1161 " port: %d\n",
1162 asoc,
1163 (&t->ipaddr),
Al Virob3f5b3b2006-11-20 17:22:43 -08001164 ntohs(t->ipaddr.v4.sin_port));
Frank Filz3f7a87d2005-06-20 13:14:57 -07001165}
1166
1167/* Choose the transport for sending a INIT packet. */
1168struct sctp_transport *sctp_assoc_choose_init_transport(
1169 struct sctp_association *asoc)
1170{
1171 struct sctp_transport *t;
1172
1173 /* Use the retran path. If the last INIT was sent over the
1174 * retran path, update the retran path and use it.
1175 */
1176 if (!asoc->init_last_sent_to) {
1177 t = asoc->peer.active_path;
1178 } else {
1179 if (asoc->init_last_sent_to == asoc->peer.retran_path)
1180 sctp_assoc_update_retran_path(asoc);
1181 t = asoc->peer.retran_path;
1182 }
1183
1184 SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_update_retran_path:association"
1185 " %p addr: ",
1186 " port: %d\n",
1187 asoc,
1188 (&t->ipaddr),
Al Virob3f5b3b2006-11-20 17:22:43 -08001189 ntohs(t->ipaddr.v4.sin_port));
Frank Filz3f7a87d2005-06-20 13:14:57 -07001190
1191 return t;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001192}
1193
1194/* Choose the transport for sending a SHUTDOWN packet. */
1195struct sctp_transport *sctp_assoc_choose_shutdown_transport(
1196 struct sctp_association *asoc)
1197{
1198 /* If this is the first time SHUTDOWN is sent, use the active path,
1199 * else use the retran path. If the last SHUTDOWN was sent over the
1200 * retran path, update the retran path and use it.
1201 */
1202 if (!asoc->shutdown_last_sent_to)
1203 return asoc->peer.active_path;
1204 else {
1205 if (asoc->shutdown_last_sent_to == asoc->peer.retran_path)
1206 sctp_assoc_update_retran_path(asoc);
1207 return asoc->peer.retran_path;
1208 }
1209
1210}
1211
1212/* Update the association's pmtu and frag_point by going through all the
1213 * transports. This routine is called when a transport's PMTU has changed.
1214 */
1215void sctp_assoc_sync_pmtu(struct sctp_association *asoc)
1216{
1217 struct sctp_transport *t;
1218 struct list_head *pos;
1219 __u32 pmtu = 0;
1220
1221 if (!asoc)
1222 return;
1223
1224 /* Get the lowest pmtu of all the transports. */
1225 list_for_each(pos, &asoc->peer.transport_addr_list) {
1226 t = list_entry(pos, struct sctp_transport, transports);
Frank Filz52ccb8e2005-12-22 11:36:46 -08001227 if (!pmtu || (t->pathmtu < pmtu))
1228 pmtu = t->pathmtu;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001229 }
1230
1231 if (pmtu) {
1232 struct sctp_sock *sp = sctp_sk(asoc->base.sk);
Frank Filz52ccb8e2005-12-22 11:36:46 -08001233 asoc->pathmtu = pmtu;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001234 asoc->frag_point = sctp_frag_point(sp, pmtu);
1235 }
1236
1237 SCTP_DEBUG_PRINTK("%s: asoc:%p, pmtu:%d, frag_point:%d\n",
Frank Filz52ccb8e2005-12-22 11:36:46 -08001238 __FUNCTION__, asoc, asoc->pathmtu, asoc->frag_point);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001239}
1240
1241/* Should we send a SACK to update our peer? */
1242static inline int sctp_peer_needs_update(struct sctp_association *asoc)
1243{
1244 switch (asoc->state) {
1245 case SCTP_STATE_ESTABLISHED:
1246 case SCTP_STATE_SHUTDOWN_PENDING:
1247 case SCTP_STATE_SHUTDOWN_RECEIVED:
1248 case SCTP_STATE_SHUTDOWN_SENT:
1249 if ((asoc->rwnd > asoc->a_rwnd) &&
1250 ((asoc->rwnd - asoc->a_rwnd) >=
Frank Filz52ccb8e2005-12-22 11:36:46 -08001251 min_t(__u32, (asoc->base.sk->sk_rcvbuf >> 1), asoc->pathmtu)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001252 return 1;
1253 break;
1254 default:
1255 break;
1256 }
1257 return 0;
1258}
1259
1260/* Increase asoc's rwnd by len and send any window update SACK if needed. */
1261void sctp_assoc_rwnd_increase(struct sctp_association *asoc, unsigned len)
1262{
1263 struct sctp_chunk *sack;
1264 struct timer_list *timer;
1265
1266 if (asoc->rwnd_over) {
1267 if (asoc->rwnd_over >= len) {
1268 asoc->rwnd_over -= len;
1269 } else {
1270 asoc->rwnd += (len - asoc->rwnd_over);
1271 asoc->rwnd_over = 0;
1272 }
1273 } else {
1274 asoc->rwnd += len;
1275 }
1276
1277 SCTP_DEBUG_PRINTK("%s: asoc %p rwnd increased by %d to (%u, %u) "
1278 "- %u\n", __FUNCTION__, asoc, len, asoc->rwnd,
1279 asoc->rwnd_over, asoc->a_rwnd);
1280
1281 /* Send a window update SACK if the rwnd has increased by at least the
1282 * minimum of the association's PMTU and half of the receive buffer.
1283 * The algorithm used is similar to the one described in
1284 * Section 4.2.3.3 of RFC 1122.
1285 */
1286 if (sctp_peer_needs_update(asoc)) {
1287 asoc->a_rwnd = asoc->rwnd;
1288 SCTP_DEBUG_PRINTK("%s: Sending window update SACK- asoc: %p "
1289 "rwnd: %u a_rwnd: %u\n", __FUNCTION__,
1290 asoc, asoc->rwnd, asoc->a_rwnd);
1291 sack = sctp_make_sack(asoc);
1292 if (!sack)
1293 return;
1294
1295 asoc->peer.sack_needed = 0;
1296
1297 sctp_outq_tail(&asoc->outqueue, sack);
1298
1299 /* Stop the SACK timer. */
1300 timer = &asoc->timers[SCTP_EVENT_TIMEOUT_SACK];
1301 if (timer_pending(timer) && del_timer(timer))
1302 sctp_association_put(asoc);
1303 }
1304}
1305
1306/* Decrease asoc's rwnd by len. */
1307void sctp_assoc_rwnd_decrease(struct sctp_association *asoc, unsigned len)
1308{
1309 SCTP_ASSERT(asoc->rwnd, "rwnd zero", return);
1310 SCTP_ASSERT(!asoc->rwnd_over, "rwnd_over not zero", return);
1311 if (asoc->rwnd >= len) {
1312 asoc->rwnd -= len;
1313 } else {
1314 asoc->rwnd_over = len - asoc->rwnd;
1315 asoc->rwnd = 0;
1316 }
1317 SCTP_DEBUG_PRINTK("%s: asoc %p rwnd decreased by %d to (%u, %u)\n",
1318 __FUNCTION__, asoc, len, asoc->rwnd,
1319 asoc->rwnd_over);
1320}
1321
1322/* Build the bind address list for the association based on info from the
1323 * local endpoint and the remote peer.
1324 */
Alexey Dobriyan3182cd842005-07-11 20:57:47 -07001325int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
Al Virodd0fc662005-10-07 07:46:04 +01001326 gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001327{
1328 sctp_scope_t scope;
1329 int flags;
1330
1331 /* Use scoping rules to determine the subset of addresses from
1332 * the endpoint.
1333 */
1334 scope = sctp_scope(&asoc->peer.active_path->ipaddr);
1335 flags = (PF_INET6 == asoc->base.sk->sk_family) ? SCTP_ADDR6_ALLOWED : 0;
1336 if (asoc->peer.ipv4_address)
1337 flags |= SCTP_ADDR4_PEERSUPP;
1338 if (asoc->peer.ipv6_address)
1339 flags |= SCTP_ADDR6_PEERSUPP;
1340
1341 return sctp_bind_addr_copy(&asoc->base.bind_addr,
1342 &asoc->ep->base.bind_addr,
1343 scope, gfp, flags);
1344}
1345
1346/* Build the association's bind address list from the cookie. */
1347int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *asoc,
Alexey Dobriyan3182cd842005-07-11 20:57:47 -07001348 struct sctp_cookie *cookie,
Al Virodd0fc662005-10-07 07:46:04 +01001349 gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001350{
1351 int var_size2 = ntohs(cookie->peer_init->chunk_hdr.length);
1352 int var_size3 = cookie->raw_addr_list_len;
1353 __u8 *raw = (__u8 *)cookie->peer_init + var_size2;
1354
1355 return sctp_raw_to_bind_addrs(&asoc->base.bind_addr, raw, var_size3,
1356 asoc->ep->base.bind_addr.port, gfp);
1357}
1358
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001359/* Lookup laddr in the bind address list of an association. */
1360int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001361 const union sctp_addr *laddr)
1362{
1363 int found;
1364
1365 sctp_read_lock(&asoc->base.addr_lock);
1366 if ((asoc->base.bind_addr.port == ntohs(laddr->v4.sin_port)) &&
1367 sctp_bind_addr_match(&asoc->base.bind_addr, laddr,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001368 sctp_sk(asoc->base.sk))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001369 found = 1;
1370 goto out;
1371 }
1372
1373 found = 0;
1374out:
1375 sctp_read_unlock(&asoc->base.addr_lock);
1376 return found;
1377}