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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>
55#include <linux/sched.h>
56
57#include <linux/slab.h>
58#include <linux/in.h>
59#include <net/ipv6.h>
60#include <net/sctp/sctp.h>
61#include <net/sctp/sm.h>
62
63/* Forward declarations for internal functions. */
David Howellsc4028952006-11-22 14:57:56 +000064static void sctp_assoc_bh_rcv(struct work_struct *work);
Linus Torvalds1da177e2005-04-16 15:20:36 -070065
66
67/* 1st Level Abstractions. */
68
69/* Initialize a new association from provided memory. */
70static struct sctp_association *sctp_association_init(struct sctp_association *asoc,
71 const struct sctp_endpoint *ep,
72 const struct sock *sk,
73 sctp_scope_t scope,
Al Virodd0fc662005-10-07 07:46:04 +010074 gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -070075{
76 struct sctp_sock *sp;
77 int i;
78
79 /* Retrieve the SCTP per socket area. */
80 sp = sctp_sk((struct sock *)sk);
81
82 /* Init all variables to a known value. */
83 memset(asoc, 0, sizeof(struct sctp_association));
84
85 /* Discarding const is appropriate here. */
86 asoc->ep = (struct sctp_endpoint *)ep;
87 sctp_endpoint_hold(asoc->ep);
88
89 /* Hold the sock. */
90 asoc->base.sk = (struct sock *)sk;
91 sock_hold(asoc->base.sk);
92
93 /* Initialize the common base substructure. */
94 asoc->base.type = SCTP_EP_TYPE_ASSOCIATION;
95
96 /* Initialize the object handling fields. */
97 atomic_set(&asoc->base.refcnt, 1);
98 asoc->base.dead = 0;
99 asoc->base.malloced = 0;
100
101 /* Initialize the bind addr area. */
102 sctp_bind_addr_init(&asoc->base.bind_addr, ep->base.bind_addr.port);
103 rwlock_init(&asoc->base.addr_lock);
104
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 */
147 asoc->max_burst = sctp_max_burst;
148
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 */
161 asoc->timeouts[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD]
162 = 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;
168
169 /* 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 */
268 asoc->peer.asconf_capable = 1;
269
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
303 return asoc;
304
305fail_init:
306 sctp_endpoint_put(asoc->ep);
307 sock_put(asoc->base.sk);
308 return NULL;
309}
310
311/* Allocate and initialize a new association */
312struct sctp_association *sctp_association_new(const struct sctp_endpoint *ep,
313 const struct sock *sk,
Alexey Dobriyan3182cd82005-07-11 20:57:47 -0700314 sctp_scope_t scope,
Al Virodd0fc662005-10-07 07:46:04 +0100315 gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316{
317 struct sctp_association *asoc;
318
319 asoc = t_new(struct sctp_association, gfp);
320 if (!asoc)
321 goto fail;
322
323 if (!sctp_association_init(asoc, ep, sk, scope, gfp))
324 goto fail_init;
325
326 asoc->base.malloced = 1;
327 SCTP_DBG_OBJCNT_INC(assoc);
Frank Filz3f7a87d2005-06-20 13:14:57 -0700328 SCTP_DEBUG_PRINTK("Created asoc %p\n", asoc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329
330 return asoc;
331
332fail_init:
333 kfree(asoc);
334fail:
335 return NULL;
336}
337
338/* Free this association if possible. There may still be users, so
339 * the actual deallocation may be delayed.
340 */
341void sctp_association_free(struct sctp_association *asoc)
342{
343 struct sock *sk = asoc->base.sk;
344 struct sctp_transport *transport;
345 struct list_head *pos, *temp;
346 int i;
347
Vlad Yasevichde76e692006-10-30 18:55:11 -0800348 /* Only real associations count against the endpoint, so
349 * don't bother for if this is a temporary association.
350 */
351 if (!asoc->temp) {
352 list_del(&asoc->asocs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353
Vlad Yasevichde76e692006-10-30 18:55:11 -0800354 /* Decrement the backlog value for a TCP-style listening
355 * socket.
356 */
357 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
358 sk->sk_ack_backlog--;
359 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360
361 /* Mark as dead, so other users can know this structure is
362 * going away.
363 */
364 asoc->base.dead = 1;
365
366 /* Dispose of any data lying around in the outqueue. */
367 sctp_outq_free(&asoc->outqueue);
368
369 /* Dispose of any pending messages for the upper layer. */
370 sctp_ulpq_free(&asoc->ulpq);
371
372 /* Dispose of any pending chunks on the inqueue. */
373 sctp_inq_free(&asoc->base.inqueue);
374
375 /* Free ssnmap storage. */
376 sctp_ssnmap_free(asoc->ssnmap);
377
378 /* Clean up the bound address list. */
379 sctp_bind_addr_free(&asoc->base.bind_addr);
380
381 /* Do we need to go through all of our timers and
382 * delete them? To be safe we will try to delete all, but we
383 * should be able to go through and make a guess based
384 * on our state.
385 */
386 for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i) {
387 if (timer_pending(&asoc->timers[i]) &&
388 del_timer(&asoc->timers[i]))
389 sctp_association_put(asoc);
390 }
391
392 /* Free peer's cached cookie. */
Jesper Juhla51482b2005-11-08 09:41:34 -0800393 kfree(asoc->peer.cookie);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394
395 /* Release the transport structures. */
396 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
397 transport = list_entry(pos, struct sctp_transport, transports);
398 list_del(pos);
399 sctp_transport_free(transport);
400 }
401
Frank Filz3f7a87d2005-06-20 13:14:57 -0700402 asoc->peer.transport_count = 0;
403
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404 /* Free any cached ASCONF_ACK chunk. */
405 if (asoc->addip_last_asconf_ack)
406 sctp_chunk_free(asoc->addip_last_asconf_ack);
407
408 /* Free any cached ASCONF chunk. */
409 if (asoc->addip_last_asconf)
410 sctp_chunk_free(asoc->addip_last_asconf);
411
412 sctp_association_put(asoc);
413}
414
415/* Cleanup and free up an association. */
416static void sctp_association_destroy(struct sctp_association *asoc)
417{
418 SCTP_ASSERT(asoc->base.dead, "Assoc is not dead", return);
419
420 sctp_endpoint_put(asoc->ep);
421 sock_put(asoc->base.sk);
422
423 if (asoc->assoc_id != 0) {
424 spin_lock_bh(&sctp_assocs_id_lock);
425 idr_remove(&sctp_assocs_id, asoc->assoc_id);
426 spin_unlock_bh(&sctp_assocs_id_lock);
427 }
428
Neil Horman049b3ff2005-11-11 16:08:24 -0800429 BUG_TRAP(!atomic_read(&asoc->rmem_alloc));
430
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431 if (asoc->base.malloced) {
432 kfree(asoc);
433 SCTP_DBG_OBJCNT_DEC(assoc);
434 }
435}
436
437/* Change the primary destination address for the peer. */
438void sctp_assoc_set_primary(struct sctp_association *asoc,
439 struct sctp_transport *transport)
440{
441 asoc->peer.primary_path = transport;
442
443 /* Set a default msg_name for events. */
444 memcpy(&asoc->peer.primary_addr, &transport->ipaddr,
445 sizeof(union sctp_addr));
446
447 /* If the primary path is changing, assume that the
448 * user wants to use this new path.
449 */
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700450 if ((transport->state == SCTP_ACTIVE) ||
451 (transport->state == SCTP_UNKNOWN))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452 asoc->peer.active_path = transport;
453
454 /*
455 * SFR-CACC algorithm:
456 * Upon the receipt of a request to change the primary
457 * destination address, on the data structure for the new
458 * primary destination, the sender MUST do the following:
459 *
460 * 1) If CHANGEOVER_ACTIVE is set, then there was a switch
461 * to this destination address earlier. The sender MUST set
462 * CYCLING_CHANGEOVER to indicate that this switch is a
463 * double switch to the same destination address.
464 */
465 if (transport->cacc.changeover_active)
466 transport->cacc.cycling_changeover = 1;
467
468 /* 2) The sender MUST set CHANGEOVER_ACTIVE to indicate that
469 * a changeover has occurred.
470 */
471 transport->cacc.changeover_active = 1;
472
473 /* 3) The sender MUST store the next TSN to be sent in
474 * next_tsn_at_change.
475 */
476 transport->cacc.next_tsn_at_change = asoc->next_tsn;
477}
478
Frank Filz3f7a87d2005-06-20 13:14:57 -0700479/* Remove a transport from an association. */
480void sctp_assoc_rm_peer(struct sctp_association *asoc,
481 struct sctp_transport *peer)
482{
483 struct list_head *pos;
484 struct sctp_transport *transport;
485
486 SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_rm_peer:association %p addr: ",
487 " port: %d\n",
488 asoc,
489 (&peer->ipaddr),
Al Virob3f5b3b2006-11-20 17:22:43 -0800490 ntohs(peer->ipaddr.v4.sin_port));
Frank Filz3f7a87d2005-06-20 13:14:57 -0700491
492 /* If we are to remove the current retran_path, update it
493 * to the next peer before removing this peer from the list.
494 */
495 if (asoc->peer.retran_path == peer)
496 sctp_assoc_update_retran_path(asoc);
497
498 /* Remove this peer from the list. */
499 list_del(&peer->transports);
500
501 /* Get the first transport of asoc. */
502 pos = asoc->peer.transport_addr_list.next;
503 transport = list_entry(pos, struct sctp_transport, transports);
504
505 /* Update any entries that match the peer to be deleted. */
506 if (asoc->peer.primary_path == peer)
507 sctp_assoc_set_primary(asoc, transport);
508 if (asoc->peer.active_path == peer)
509 asoc->peer.active_path = transport;
510 if (asoc->peer.last_data_from == peer)
511 asoc->peer.last_data_from = transport;
512
513 /* If we remove the transport an INIT was last sent to, set it to
514 * NULL. Combined with the update of the retran path above, this
515 * will cause the next INIT to be sent to the next available
516 * transport, maintaining the cycle.
517 */
518 if (asoc->init_last_sent_to == peer)
519 asoc->init_last_sent_to = NULL;
520
521 asoc->peer.transport_count--;
522
523 sctp_transport_free(peer);
524}
525
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526/* Add a transport address to an association. */
527struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc,
528 const union sctp_addr *addr,
Al Virodd0fc662005-10-07 07:46:04 +0100529 const gfp_t gfp,
Frank Filz3f7a87d2005-06-20 13:14:57 -0700530 const int peer_state)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531{
532 struct sctp_transport *peer;
533 struct sctp_sock *sp;
534 unsigned short port;
535
536 sp = sctp_sk(asoc->base.sk);
537
538 /* AF_INET and AF_INET6 share common port field. */
Al Viro4bdf4b52006-11-20 17:10:20 -0800539 port = ntohs(addr->v4.sin_port);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700540
Frank Filz3f7a87d2005-06-20 13:14:57 -0700541 SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_add_peer:association %p addr: ",
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700542 " port: %d state:%d\n",
Frank Filz3f7a87d2005-06-20 13:14:57 -0700543 asoc,
544 addr,
Al Viro4bdf4b52006-11-20 17:10:20 -0800545 port,
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700546 peer_state);
Frank Filz3f7a87d2005-06-20 13:14:57 -0700547
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548 /* Set the port if it has not been set yet. */
549 if (0 == asoc->peer.port)
550 asoc->peer.port = port;
551
552 /* Check to see if this is a duplicate. */
553 peer = sctp_assoc_lookup_paddr(asoc, addr);
Frank Filz3f7a87d2005-06-20 13:14:57 -0700554 if (peer) {
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700555 if (peer->state == SCTP_UNKNOWN) {
556 if (peer_state == SCTP_ACTIVE)
557 peer->state = SCTP_ACTIVE;
558 if (peer_state == SCTP_UNCONFIRMED)
559 peer->state = SCTP_UNCONFIRMED;
560 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561 return peer;
Frank Filz3f7a87d2005-06-20 13:14:57 -0700562 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563
564 peer = sctp_transport_new(addr, gfp);
565 if (!peer)
566 return NULL;
567
568 sctp_transport_set_owner(peer, asoc);
569
Frank Filz52ccb8e2005-12-22 11:36:46 -0800570 /* Initialize the peer's heartbeat interval based on the
571 * association configured value.
572 */
573 peer->hbinterval = asoc->hbinterval;
574
575 /* Set the path max_retrans. */
576 peer->pathmaxrxt = asoc->pathmaxrxt;
577
578 /* Initialize the peer's SACK delay timeout based on the
579 * association configured value.
580 */
581 peer->sackdelay = asoc->sackdelay;
582
583 /* Enable/disable heartbeat, SACK delay, and path MTU discovery
584 * based on association setting.
585 */
586 peer->param_flags = asoc->param_flags;
587
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588 /* Initialize the pmtu of the transport. */
Frank Filz52ccb8e2005-12-22 11:36:46 -0800589 if (peer->param_flags & SPP_PMTUD_ENABLE)
590 sctp_transport_pmtu(peer);
591 else if (asoc->pathmtu)
592 peer->pathmtu = asoc->pathmtu;
593 else
594 peer->pathmtu = SCTP_DEFAULT_MAXSEGMENT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595
596 /* If this is the first transport addr on this association,
597 * initialize the association PMTU to the peer's PMTU.
598 * If not and the current association PMTU is higher than the new
599 * peer's PMTU, reset the association PMTU to the new peer's PMTU.
600 */
Frank Filz52ccb8e2005-12-22 11:36:46 -0800601 if (asoc->pathmtu)
602 asoc->pathmtu = min_t(int, peer->pathmtu, asoc->pathmtu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603 else
Frank Filz52ccb8e2005-12-22 11:36:46 -0800604 asoc->pathmtu = peer->pathmtu;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700605
606 SCTP_DEBUG_PRINTK("sctp_assoc_add_peer:association %p PMTU set to "
Frank Filz52ccb8e2005-12-22 11:36:46 -0800607 "%d\n", asoc, asoc->pathmtu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700608
Frank Filz52ccb8e2005-12-22 11:36:46 -0800609 asoc->frag_point = sctp_frag_point(sp, asoc->pathmtu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700610
611 /* The asoc->peer.port might not be meaningful yet, but
612 * initialize the packet structure anyway.
613 */
614 sctp_packet_init(&peer->packet, peer, asoc->base.bind_addr.port,
615 asoc->peer.port);
616
617 /* 7.2.1 Slow-Start
618 *
619 * o The initial cwnd before DATA transmission or after a sufficiently
620 * long idle period MUST be set to
621 * min(4*MTU, max(2*MTU, 4380 bytes))
622 *
623 * o The initial value of ssthresh MAY be arbitrarily high
624 * (for example, implementations MAY use the size of the
625 * receiver advertised window).
626 */
Frank Filz52ccb8e2005-12-22 11:36:46 -0800627 peer->cwnd = min(4*asoc->pathmtu, max_t(__u32, 2*asoc->pathmtu, 4380));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700628
629 /* At this point, we may not have the receiver's advertised window,
630 * so initialize ssthresh to the default value and it will be set
631 * later when we process the INIT.
632 */
633 peer->ssthresh = SCTP_DEFAULT_MAXWINDOW;
634
635 peer->partial_bytes_acked = 0;
636 peer->flight_size = 0;
637
Linus Torvalds1da177e2005-04-16 15:20:36 -0700638 /* Set the transport's RTO.initial value */
639 peer->rto = asoc->rto_initial;
640
Frank Filz3f7a87d2005-06-20 13:14:57 -0700641 /* Set the peer's active state. */
642 peer->state = peer_state;
643
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644 /* Attach the remote transport to our asoc. */
645 list_add_tail(&peer->transports, &asoc->peer.transport_addr_list);
Frank Filz3f7a87d2005-06-20 13:14:57 -0700646 asoc->peer.transport_count++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647
648 /* If we do not yet have a primary path, set one. */
649 if (!asoc->peer.primary_path) {
650 sctp_assoc_set_primary(asoc, peer);
651 asoc->peer.retran_path = peer;
652 }
653
Frank Filz3f7a87d2005-06-20 13:14:57 -0700654 if (asoc->peer.active_path == asoc->peer.retran_path) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700655 asoc->peer.retran_path = peer;
Frank Filz3f7a87d2005-06-20 13:14:57 -0700656 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657
658 return peer;
659}
660
661/* Delete a transport address from an association. */
662void sctp_assoc_del_peer(struct sctp_association *asoc,
663 const union sctp_addr *addr)
664{
665 struct list_head *pos;
666 struct list_head *temp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667 struct sctp_transport *transport;
668
669 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
670 transport = list_entry(pos, struct sctp_transport, transports);
671 if (sctp_cmp_addr_exact(addr, &transport->ipaddr)) {
Frank Filz3f7a87d2005-06-20 13:14:57 -0700672 /* Do book keeping for removing the peer and free it. */
673 sctp_assoc_rm_peer(asoc, transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700674 break;
675 }
676 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677}
678
679/* Lookup a transport by address. */
680struct sctp_transport *sctp_assoc_lookup_paddr(
681 const struct sctp_association *asoc,
682 const union sctp_addr *address)
683{
684 struct sctp_transport *t;
685 struct list_head *pos;
686
687 /* Cycle through all transports searching for a peer address. */
688
689 list_for_each(pos, &asoc->peer.transport_addr_list) {
690 t = list_entry(pos, struct sctp_transport, transports);
691 if (sctp_cmp_addr_exact(address, &t->ipaddr))
692 return t;
693 }
694
695 return NULL;
696}
697
698/* Engage in transport control operations.
699 * Mark the transport up or down and send a notification to the user.
700 * Select and update the new active and retran paths.
701 */
702void sctp_assoc_control_transport(struct sctp_association *asoc,
703 struct sctp_transport *transport,
704 sctp_transport_cmd_t command,
705 sctp_sn_error_t error)
706{
707 struct sctp_transport *t = NULL;
708 struct sctp_transport *first;
709 struct sctp_transport *second;
710 struct sctp_ulpevent *event;
Al Viro0906e202006-11-20 17:03:01 -0800711 struct sockaddr_storage addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712 struct list_head *pos;
713 int spc_state = 0;
714
715 /* Record the transition on the transport. */
716 switch (command) {
717 case SCTP_TRANSPORT_UP:
Frank Filz3f7a87d2005-06-20 13:14:57 -0700718 transport->state = SCTP_ACTIVE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700719 spc_state = SCTP_ADDR_AVAILABLE;
720 break;
721
722 case SCTP_TRANSPORT_DOWN:
Frank Filz3f7a87d2005-06-20 13:14:57 -0700723 transport->state = SCTP_INACTIVE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700724 spc_state = SCTP_ADDR_UNREACHABLE;
725 break;
726
727 default:
728 return;
729 };
730
731 /* Generate and send a SCTP_PEER_ADDR_CHANGE notification to the
732 * user.
733 */
Al Viro0906e202006-11-20 17:03:01 -0800734 memset(&addr, 0, sizeof(struct sockaddr_storage));
Al Viro8cec6b82006-11-20 17:23:01 -0800735 memcpy(&addr, &transport->ipaddr, transport->af_specific->sockaddr_len);
Al Viro0906e202006-11-20 17:03:01 -0800736 event = sctp_ulpevent_make_peer_addr_change(asoc, &addr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700737 0, spc_state, error, GFP_ATOMIC);
738 if (event)
739 sctp_ulpq_tail_event(&asoc->ulpq, event);
740
741 /* Select new active and retran paths. */
742
743 /* Look for the two most recently used active transports.
744 *
745 * This code produces the wrong ordering whenever jiffies
746 * rolls over, but we still get usable transports, so we don't
747 * worry about it.
748 */
749 first = NULL; second = NULL;
750
751 list_for_each(pos, &asoc->peer.transport_addr_list) {
752 t = list_entry(pos, struct sctp_transport, transports);
753
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700754 if ((t->state == SCTP_INACTIVE) ||
755 (t->state == SCTP_UNCONFIRMED))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700756 continue;
757 if (!first || t->last_time_heard > first->last_time_heard) {
758 second = first;
759 first = t;
760 }
761 if (!second || t->last_time_heard > second->last_time_heard)
762 second = t;
763 }
764
765 /* RFC 2960 6.4 Multi-Homed SCTP Endpoints
766 *
767 * By default, an endpoint should always transmit to the
768 * primary path, unless the SCTP user explicitly specifies the
769 * destination transport address (and possibly source
770 * transport address) to use.
771 *
772 * [If the primary is active but not most recent, bump the most
773 * recently used transport.]
774 */
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700775 if (((asoc->peer.primary_path->state == SCTP_ACTIVE) ||
776 (asoc->peer.primary_path->state == SCTP_UNKNOWN)) &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777 first != asoc->peer.primary_path) {
778 second = first;
779 first = asoc->peer.primary_path;
780 }
781
782 /* If we failed to find a usable transport, just camp on the
783 * primary, even if it is inactive.
784 */
785 if (!first) {
786 first = asoc->peer.primary_path;
787 second = asoc->peer.primary_path;
788 }
789
790 /* Set the active and retran transports. */
791 asoc->peer.active_path = first;
792 asoc->peer.retran_path = second;
793}
794
795/* Hold a reference to an association. */
796void sctp_association_hold(struct sctp_association *asoc)
797{
798 atomic_inc(&asoc->base.refcnt);
799}
800
801/* Release a reference to an association and cleanup
802 * if there are no more references.
803 */
804void sctp_association_put(struct sctp_association *asoc)
805{
806 if (atomic_dec_and_test(&asoc->base.refcnt))
807 sctp_association_destroy(asoc);
808}
809
810/* Allocate the next TSN, Transmission Sequence Number, for the given
811 * association.
812 */
813__u32 sctp_association_get_next_tsn(struct sctp_association *asoc)
814{
815 /* From Section 1.6 Serial Number Arithmetic:
816 * Transmission Sequence Numbers wrap around when they reach
817 * 2**32 - 1. That is, the next TSN a DATA chunk MUST use
818 * after transmitting TSN = 2*32 - 1 is TSN = 0.
819 */
820 __u32 retval = asoc->next_tsn;
821 asoc->next_tsn++;
822 asoc->unack_data++;
823
824 return retval;
825}
826
827/* Compare two addresses to see if they match. Wildcard addresses
828 * only match themselves.
829 */
830int sctp_cmp_addr_exact(const union sctp_addr *ss1,
831 const union sctp_addr *ss2)
832{
833 struct sctp_af *af;
834
835 af = sctp_get_af_specific(ss1->sa.sa_family);
836 if (unlikely(!af))
837 return 0;
838
839 return af->cmp_addr(ss1, ss2);
840}
841
842/* Return an ecne chunk to get prepended to a packet.
843 * Note: We are sly and return a shared, prealloced chunk. FIXME:
844 * No we don't, but we could/should.
845 */
846struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc)
847{
848 struct sctp_chunk *chunk;
849
850 /* Send ECNE if needed.
851 * Not being able to allocate a chunk here is not deadly.
852 */
853 if (asoc->need_ecne)
854 chunk = sctp_make_ecne(asoc, asoc->last_ecne_tsn);
855 else
856 chunk = NULL;
857
858 return chunk;
859}
860
861/*
862 * Find which transport this TSN was sent on.
863 */
864struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *asoc,
865 __u32 tsn)
866{
867 struct sctp_transport *active;
868 struct sctp_transport *match;
869 struct list_head *entry, *pos;
870 struct sctp_transport *transport;
871 struct sctp_chunk *chunk;
Al Virodbc16db2006-11-20 17:01:42 -0800872 __be32 key = htonl(tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700873
874 match = NULL;
875
876 /*
877 * FIXME: In general, find a more efficient data structure for
878 * searching.
879 */
880
881 /*
882 * The general strategy is to search each transport's transmitted
883 * list. Return which transport this TSN lives on.
884 *
885 * Let's be hopeful and check the active_path first.
886 * Another optimization would be to know if there is only one
887 * outbound path and not have to look for the TSN at all.
888 *
889 */
890
891 active = asoc->peer.active_path;
892
893 list_for_each(entry, &active->transmitted) {
894 chunk = list_entry(entry, struct sctp_chunk, transmitted_list);
895
896 if (key == chunk->subh.data_hdr->tsn) {
897 match = active;
898 goto out;
899 }
900 }
901
902 /* If not found, go search all the other transports. */
903 list_for_each(pos, &asoc->peer.transport_addr_list) {
904 transport = list_entry(pos, struct sctp_transport, transports);
905
906 if (transport == active)
907 break;
908 list_for_each(entry, &transport->transmitted) {
909 chunk = list_entry(entry, struct sctp_chunk,
910 transmitted_list);
911 if (key == chunk->subh.data_hdr->tsn) {
912 match = transport;
913 goto out;
914 }
915 }
916 }
917out:
918 return match;
919}
920
921/* Is this the association we are looking for? */
922struct sctp_transport *sctp_assoc_is_match(struct sctp_association *asoc,
923 const union sctp_addr *laddr,
924 const union sctp_addr *paddr)
925{
926 struct sctp_transport *transport;
927
928 sctp_read_lock(&asoc->base.addr_lock);
929
Al Viroe2fcced2006-11-20 17:08:41 -0800930 if ((htons(asoc->base.bind_addr.port) == laddr->v4.sin_port) &&
931 (htons(asoc->peer.port) == paddr->v4.sin_port)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700932 transport = sctp_assoc_lookup_paddr(asoc, paddr);
933 if (!transport)
934 goto out;
935
936 if (sctp_bind_addr_match(&asoc->base.bind_addr, laddr,
937 sctp_sk(asoc->base.sk)))
938 goto out;
939 }
940 transport = NULL;
941
942out:
943 sctp_read_unlock(&asoc->base.addr_lock);
944 return transport;
945}
946
947/* Do delayed input processing. This is scheduled by sctp_rcv(). */
David Howellsc4028952006-11-22 14:57:56 +0000948static void sctp_assoc_bh_rcv(struct work_struct *work)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700949{
David Howellsc4028952006-11-22 14:57:56 +0000950 struct sctp_association *asoc =
951 container_of(work, struct sctp_association,
952 base.inqueue.immediate);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700953 struct sctp_endpoint *ep;
954 struct sctp_chunk *chunk;
955 struct sock *sk;
956 struct sctp_inq *inqueue;
957 int state;
958 sctp_subtype_t subtype;
959 int error = 0;
960
961 /* The association should be held so we should be safe. */
962 ep = asoc->ep;
963 sk = asoc->base.sk;
964
965 inqueue = &asoc->base.inqueue;
966 sctp_association_hold(asoc);
967 while (NULL != (chunk = sctp_inq_pop(inqueue))) {
968 state = asoc->state;
969 subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type);
970
971 /* Remember where the last DATA chunk came from so we
972 * know where to send the SACK.
973 */
974 if (sctp_chunk_is_data(chunk))
975 asoc->peer.last_data_from = chunk->transport;
976 else
977 SCTP_INC_STATS(SCTP_MIB_INCTRLCHUNKS);
978
979 if (chunk->transport)
980 chunk->transport->last_time_heard = jiffies;
981
982 /* Run through the state machine. */
983 error = sctp_do_sm(SCTP_EVENT_T_CHUNK, subtype,
984 state, ep, asoc, chunk, GFP_ATOMIC);
985
986 /* Check to see if the association is freed in response to
987 * the incoming chunk. If so, get out of the while loop.
988 */
989 if (asoc->base.dead)
990 break;
991
992 /* If there is an error on chunk, discard this packet. */
993 if (error && chunk)
994 chunk->pdiscard = 1;
995 }
996 sctp_association_put(asoc);
997}
998
999/* This routine moves an association from its old sk to a new sk. */
1000void sctp_assoc_migrate(struct sctp_association *assoc, struct sock *newsk)
1001{
1002 struct sctp_sock *newsp = sctp_sk(newsk);
1003 struct sock *oldsk = assoc->base.sk;
1004
1005 /* Delete the association from the old endpoint's list of
1006 * associations.
1007 */
1008 list_del_init(&assoc->asocs);
1009
1010 /* Decrement the backlog value for a TCP-style socket. */
1011 if (sctp_style(oldsk, TCP))
1012 oldsk->sk_ack_backlog--;
1013
1014 /* Release references to the old endpoint and the sock. */
1015 sctp_endpoint_put(assoc->ep);
1016 sock_put(assoc->base.sk);
1017
1018 /* Get a reference to the new endpoint. */
1019 assoc->ep = newsp->ep;
1020 sctp_endpoint_hold(assoc->ep);
1021
1022 /* Get a reference to the new sock. */
1023 assoc->base.sk = newsk;
1024 sock_hold(assoc->base.sk);
1025
1026 /* Add the association to the new endpoint's list of associations. */
1027 sctp_endpoint_add_asoc(newsp->ep, assoc);
1028}
1029
1030/* Update an association (possibly from unexpected COOKIE-ECHO processing). */
1031void sctp_assoc_update(struct sctp_association *asoc,
1032 struct sctp_association *new)
1033{
1034 struct sctp_transport *trans;
1035 struct list_head *pos, *temp;
1036
1037 /* Copy in new parameters of peer. */
1038 asoc->c = new->c;
1039 asoc->peer.rwnd = new->peer.rwnd;
1040 asoc->peer.sack_needed = new->peer.sack_needed;
1041 asoc->peer.i = new->peer.i;
1042 sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_SIZE,
1043 asoc->peer.i.initial_tsn);
1044
1045 /* Remove any peer addresses not present in the new association. */
1046 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
1047 trans = list_entry(pos, struct sctp_transport, transports);
1048 if (!sctp_assoc_lookup_paddr(new, &trans->ipaddr))
1049 sctp_assoc_del_peer(asoc, &trans->ipaddr);
1050 }
1051
1052 /* If the case is A (association restart), use
1053 * initial_tsn as next_tsn. If the case is B, use
1054 * current next_tsn in case data sent to peer
1055 * has been discarded and needs retransmission.
1056 */
1057 if (asoc->state >= SCTP_STATE_ESTABLISHED) {
1058 asoc->next_tsn = new->next_tsn;
1059 asoc->ctsn_ack_point = new->ctsn_ack_point;
1060 asoc->adv_peer_ack_point = new->adv_peer_ack_point;
1061
1062 /* Reinitialize SSN for both local streams
1063 * and peer's streams.
1064 */
1065 sctp_ssnmap_clear(asoc->ssnmap);
1066
1067 } else {
1068 /* Add any peer addresses from the new association. */
1069 list_for_each(pos, &new->peer.transport_addr_list) {
1070 trans = list_entry(pos, struct sctp_transport,
1071 transports);
1072 if (!sctp_assoc_lookup_paddr(asoc, &trans->ipaddr))
1073 sctp_assoc_add_peer(asoc, &trans->ipaddr,
Sridhar Samudralaad8fec12006-07-21 14:48:50 -07001074 GFP_ATOMIC, trans->state);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001075 }
1076
1077 asoc->ctsn_ack_point = asoc->next_tsn - 1;
1078 asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
1079 if (!asoc->ssnmap) {
1080 /* Move the ssnmap. */
1081 asoc->ssnmap = new->ssnmap;
1082 new->ssnmap = NULL;
1083 }
1084 }
1085}
1086
1087/* Update the retran path for sending a retransmitted packet.
1088 * Round-robin through the active transports, else round-robin
1089 * through the inactive transports as this is the next best thing
1090 * we can try.
1091 */
1092void sctp_assoc_update_retran_path(struct sctp_association *asoc)
1093{
1094 struct sctp_transport *t, *next;
1095 struct list_head *head = &asoc->peer.transport_addr_list;
1096 struct list_head *pos;
1097
1098 /* Find the next transport in a round-robin fashion. */
1099 t = asoc->peer.retran_path;
1100 pos = &t->transports;
1101 next = NULL;
1102
1103 while (1) {
1104 /* Skip the head. */
1105 if (pos->next == head)
1106 pos = head->next;
1107 else
1108 pos = pos->next;
1109
1110 t = list_entry(pos, struct sctp_transport, transports);
1111
1112 /* Try to find an active transport. */
1113
Sridhar Samudralaad8fec12006-07-21 14:48:50 -07001114 if ((t->state == SCTP_ACTIVE) ||
1115 (t->state == SCTP_UNKNOWN)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001116 break;
1117 } else {
1118 /* Keep track of the next transport in case
1119 * we don't find any active transport.
1120 */
1121 if (!next)
1122 next = t;
1123 }
1124
1125 /* We have exhausted the list, but didn't find any
1126 * other active transports. If so, use the next
1127 * transport.
1128 */
1129 if (t == asoc->peer.retran_path) {
1130 t = next;
1131 break;
1132 }
1133 }
1134
1135 asoc->peer.retran_path = t;
Frank Filz3f7a87d2005-06-20 13:14:57 -07001136
1137 SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_update_retran_path:association"
1138 " %p addr: ",
1139 " port: %d\n",
1140 asoc,
1141 (&t->ipaddr),
Al Virob3f5b3b2006-11-20 17:22:43 -08001142 ntohs(t->ipaddr.v4.sin_port));
Frank Filz3f7a87d2005-06-20 13:14:57 -07001143}
1144
1145/* Choose the transport for sending a INIT packet. */
1146struct sctp_transport *sctp_assoc_choose_init_transport(
1147 struct sctp_association *asoc)
1148{
1149 struct sctp_transport *t;
1150
1151 /* Use the retran path. If the last INIT was sent over the
1152 * retran path, update the retran path and use it.
1153 */
1154 if (!asoc->init_last_sent_to) {
1155 t = asoc->peer.active_path;
1156 } else {
1157 if (asoc->init_last_sent_to == asoc->peer.retran_path)
1158 sctp_assoc_update_retran_path(asoc);
1159 t = asoc->peer.retran_path;
1160 }
1161
1162 SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_update_retran_path:association"
1163 " %p addr: ",
1164 " port: %d\n",
1165 asoc,
1166 (&t->ipaddr),
Al Virob3f5b3b2006-11-20 17:22:43 -08001167 ntohs(t->ipaddr.v4.sin_port));
Frank Filz3f7a87d2005-06-20 13:14:57 -07001168
1169 return t;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001170}
1171
1172/* Choose the transport for sending a SHUTDOWN packet. */
1173struct sctp_transport *sctp_assoc_choose_shutdown_transport(
1174 struct sctp_association *asoc)
1175{
1176 /* If this is the first time SHUTDOWN is sent, use the active path,
1177 * else use the retran path. If the last SHUTDOWN was sent over the
1178 * retran path, update the retran path and use it.
1179 */
1180 if (!asoc->shutdown_last_sent_to)
1181 return asoc->peer.active_path;
1182 else {
1183 if (asoc->shutdown_last_sent_to == asoc->peer.retran_path)
1184 sctp_assoc_update_retran_path(asoc);
1185 return asoc->peer.retran_path;
1186 }
1187
1188}
1189
1190/* Update the association's pmtu and frag_point by going through all the
1191 * transports. This routine is called when a transport's PMTU has changed.
1192 */
1193void sctp_assoc_sync_pmtu(struct sctp_association *asoc)
1194{
1195 struct sctp_transport *t;
1196 struct list_head *pos;
1197 __u32 pmtu = 0;
1198
1199 if (!asoc)
1200 return;
1201
1202 /* Get the lowest pmtu of all the transports. */
1203 list_for_each(pos, &asoc->peer.transport_addr_list) {
1204 t = list_entry(pos, struct sctp_transport, transports);
Frank Filz52ccb8e2005-12-22 11:36:46 -08001205 if (!pmtu || (t->pathmtu < pmtu))
1206 pmtu = t->pathmtu;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001207 }
1208
1209 if (pmtu) {
1210 struct sctp_sock *sp = sctp_sk(asoc->base.sk);
Frank Filz52ccb8e2005-12-22 11:36:46 -08001211 asoc->pathmtu = pmtu;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001212 asoc->frag_point = sctp_frag_point(sp, pmtu);
1213 }
1214
1215 SCTP_DEBUG_PRINTK("%s: asoc:%p, pmtu:%d, frag_point:%d\n",
Frank Filz52ccb8e2005-12-22 11:36:46 -08001216 __FUNCTION__, asoc, asoc->pathmtu, asoc->frag_point);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001217}
1218
1219/* Should we send a SACK to update our peer? */
1220static inline int sctp_peer_needs_update(struct sctp_association *asoc)
1221{
1222 switch (asoc->state) {
1223 case SCTP_STATE_ESTABLISHED:
1224 case SCTP_STATE_SHUTDOWN_PENDING:
1225 case SCTP_STATE_SHUTDOWN_RECEIVED:
1226 case SCTP_STATE_SHUTDOWN_SENT:
1227 if ((asoc->rwnd > asoc->a_rwnd) &&
1228 ((asoc->rwnd - asoc->a_rwnd) >=
Frank Filz52ccb8e2005-12-22 11:36:46 -08001229 min_t(__u32, (asoc->base.sk->sk_rcvbuf >> 1), asoc->pathmtu)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001230 return 1;
1231 break;
1232 default:
1233 break;
1234 }
1235 return 0;
1236}
1237
1238/* Increase asoc's rwnd by len and send any window update SACK if needed. */
1239void sctp_assoc_rwnd_increase(struct sctp_association *asoc, unsigned len)
1240{
1241 struct sctp_chunk *sack;
1242 struct timer_list *timer;
1243
1244 if (asoc->rwnd_over) {
1245 if (asoc->rwnd_over >= len) {
1246 asoc->rwnd_over -= len;
1247 } else {
1248 asoc->rwnd += (len - asoc->rwnd_over);
1249 asoc->rwnd_over = 0;
1250 }
1251 } else {
1252 asoc->rwnd += len;
1253 }
1254
1255 SCTP_DEBUG_PRINTK("%s: asoc %p rwnd increased by %d to (%u, %u) "
1256 "- %u\n", __FUNCTION__, asoc, len, asoc->rwnd,
1257 asoc->rwnd_over, asoc->a_rwnd);
1258
1259 /* Send a window update SACK if the rwnd has increased by at least the
1260 * minimum of the association's PMTU and half of the receive buffer.
1261 * The algorithm used is similar to the one described in
1262 * Section 4.2.3.3 of RFC 1122.
1263 */
1264 if (sctp_peer_needs_update(asoc)) {
1265 asoc->a_rwnd = asoc->rwnd;
1266 SCTP_DEBUG_PRINTK("%s: Sending window update SACK- asoc: %p "
1267 "rwnd: %u a_rwnd: %u\n", __FUNCTION__,
1268 asoc, asoc->rwnd, asoc->a_rwnd);
1269 sack = sctp_make_sack(asoc);
1270 if (!sack)
1271 return;
1272
1273 asoc->peer.sack_needed = 0;
1274
1275 sctp_outq_tail(&asoc->outqueue, sack);
1276
1277 /* Stop the SACK timer. */
1278 timer = &asoc->timers[SCTP_EVENT_TIMEOUT_SACK];
1279 if (timer_pending(timer) && del_timer(timer))
1280 sctp_association_put(asoc);
1281 }
1282}
1283
1284/* Decrease asoc's rwnd by len. */
1285void sctp_assoc_rwnd_decrease(struct sctp_association *asoc, unsigned len)
1286{
1287 SCTP_ASSERT(asoc->rwnd, "rwnd zero", return);
1288 SCTP_ASSERT(!asoc->rwnd_over, "rwnd_over not zero", return);
1289 if (asoc->rwnd >= len) {
1290 asoc->rwnd -= len;
1291 } else {
1292 asoc->rwnd_over = len - asoc->rwnd;
1293 asoc->rwnd = 0;
1294 }
1295 SCTP_DEBUG_PRINTK("%s: asoc %p rwnd decreased by %d to (%u, %u)\n",
1296 __FUNCTION__, asoc, len, asoc->rwnd,
1297 asoc->rwnd_over);
1298}
1299
1300/* Build the bind address list for the association based on info from the
1301 * local endpoint and the remote peer.
1302 */
Alexey Dobriyan3182cd82005-07-11 20:57:47 -07001303int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
Al Virodd0fc662005-10-07 07:46:04 +01001304 gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001305{
1306 sctp_scope_t scope;
1307 int flags;
1308
1309 /* Use scoping rules to determine the subset of addresses from
1310 * the endpoint.
1311 */
1312 scope = sctp_scope(&asoc->peer.active_path->ipaddr);
1313 flags = (PF_INET6 == asoc->base.sk->sk_family) ? SCTP_ADDR6_ALLOWED : 0;
1314 if (asoc->peer.ipv4_address)
1315 flags |= SCTP_ADDR4_PEERSUPP;
1316 if (asoc->peer.ipv6_address)
1317 flags |= SCTP_ADDR6_PEERSUPP;
1318
1319 return sctp_bind_addr_copy(&asoc->base.bind_addr,
1320 &asoc->ep->base.bind_addr,
1321 scope, gfp, flags);
1322}
1323
1324/* Build the association's bind address list from the cookie. */
1325int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *asoc,
Alexey Dobriyan3182cd82005-07-11 20:57:47 -07001326 struct sctp_cookie *cookie,
Al Virodd0fc662005-10-07 07:46:04 +01001327 gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001328{
1329 int var_size2 = ntohs(cookie->peer_init->chunk_hdr.length);
1330 int var_size3 = cookie->raw_addr_list_len;
1331 __u8 *raw = (__u8 *)cookie->peer_init + var_size2;
1332
1333 return sctp_raw_to_bind_addrs(&asoc->base.bind_addr, raw, var_size3,
1334 asoc->ep->base.bind_addr.port, gfp);
1335}
1336
1337/* Lookup laddr in the bind address list of an association. */
1338int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
1339 const union sctp_addr *laddr)
1340{
1341 int found;
1342
1343 sctp_read_lock(&asoc->base.addr_lock);
1344 if ((asoc->base.bind_addr.port == ntohs(laddr->v4.sin_port)) &&
1345 sctp_bind_addr_match(&asoc->base.bind_addr, laddr,
1346 sctp_sk(asoc->base.sk))) {
1347 found = 1;
1348 goto out;
1349 }
1350
1351 found = 0;
1352out:
1353 sctp_read_unlock(&asoc->base.addr_lock);
1354 return found;
1355}