kvm tools, setup: Create private directory
[linux-2.6/next.git] / net / sctp / associola.c
blob4a62888f2e43f43a7037f556257520a462d5ece2
1 /* SCTP kernel 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
8 * This file is part of the SCTP kernel implementation
10 * This module provides the abstraction for an SCTP association.
12 * This SCTP 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.
18 * This SCTP 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.
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.
29 * Please send any bug reports or fixes you make to the
30 * email address(es):
31 * lksctp developers <lksctp-developers@lists.sourceforge.net>
33 * Or submit a bug report through the following website:
34 * http://www.sf.net/projects/lksctp
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>
47 * Any bugs reported given to us we will try to fix... any fixes shared will
48 * be incorporated into the next SCTP release.
51 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
53 #include <linux/types.h>
54 #include <linux/fcntl.h>
55 #include <linux/poll.h>
56 #include <linux/init.h>
58 #include <linux/slab.h>
59 #include <linux/in.h>
60 #include <net/ipv6.h>
61 #include <net/sctp/sctp.h>
62 #include <net/sctp/sm.h>
64 /* Forward declarations for internal functions. */
65 static void sctp_assoc_bh_rcv(struct work_struct *work);
66 static void sctp_assoc_free_asconf_acks(struct sctp_association *asoc);
67 static void sctp_assoc_free_asconf_queue(struct sctp_association *asoc);
69 /* Keep track of the new idr low so that we don't re-use association id
70 * numbers too fast. It is protected by they idr spin lock is in the
71 * range of 1 - INT_MAX.
73 static u32 idr_low = 1;
76 /* 1st Level Abstractions. */
78 /* Initialize a new association from provided memory. */
79 static struct sctp_association *sctp_association_init(struct sctp_association *asoc,
80 const struct sctp_endpoint *ep,
81 const struct sock *sk,
82 sctp_scope_t scope,
83 gfp_t gfp)
85 struct sctp_sock *sp;
86 int i;
87 sctp_paramhdr_t *p;
88 int err;
90 /* Retrieve the SCTP per socket area. */
91 sp = sctp_sk((struct sock *)sk);
93 /* Discarding const is appropriate here. */
94 asoc->ep = (struct sctp_endpoint *)ep;
95 sctp_endpoint_hold(asoc->ep);
97 /* Hold the sock. */
98 asoc->base.sk = (struct sock *)sk;
99 sock_hold(asoc->base.sk);
101 /* Initialize the common base substructure. */
102 asoc->base.type = SCTP_EP_TYPE_ASSOCIATION;
104 /* Initialize the object handling fields. */
105 atomic_set(&asoc->base.refcnt, 1);
106 asoc->base.dead = 0;
107 asoc->base.malloced = 0;
109 /* Initialize the bind addr area. */
110 sctp_bind_addr_init(&asoc->base.bind_addr, ep->base.bind_addr.port);
112 asoc->state = SCTP_STATE_CLOSED;
114 /* Set these values from the socket values, a conversion between
115 * millsecons to seconds/microseconds must also be done.
117 asoc->cookie_life.tv_sec = sp->assocparams.sasoc_cookie_life / 1000;
118 asoc->cookie_life.tv_usec = (sp->assocparams.sasoc_cookie_life % 1000)
119 * 1000;
120 asoc->frag_point = 0;
121 asoc->user_frag = sp->user_frag;
123 /* Set the association max_retrans and RTO values from the
124 * socket values.
126 asoc->max_retrans = sp->assocparams.sasoc_asocmaxrxt;
127 asoc->rto_initial = msecs_to_jiffies(sp->rtoinfo.srto_initial);
128 asoc->rto_max = msecs_to_jiffies(sp->rtoinfo.srto_max);
129 asoc->rto_min = msecs_to_jiffies(sp->rtoinfo.srto_min);
131 asoc->overall_error_count = 0;
133 /* Initialize the association's heartbeat interval based on the
134 * sock configured value.
136 asoc->hbinterval = msecs_to_jiffies(sp->hbinterval);
138 /* Initialize path max retrans value. */
139 asoc->pathmaxrxt = sp->pathmaxrxt;
141 /* Initialize default path MTU. */
142 asoc->pathmtu = sp->pathmtu;
144 /* Set association default SACK delay */
145 asoc->sackdelay = msecs_to_jiffies(sp->sackdelay);
146 asoc->sackfreq = sp->sackfreq;
148 /* Set the association default flags controlling
149 * Heartbeat, SACK delay, and Path MTU Discovery.
151 asoc->param_flags = sp->param_flags;
153 /* Initialize the maximum mumber of new data packets that can be sent
154 * in a burst.
156 asoc->max_burst = sp->max_burst;
158 /* initialize association timers */
159 asoc->timeouts[SCTP_EVENT_TIMEOUT_NONE] = 0;
160 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] = asoc->rto_initial;
161 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] = asoc->rto_initial;
162 asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = asoc->rto_initial;
163 asoc->timeouts[SCTP_EVENT_TIMEOUT_T3_RTX] = 0;
164 asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = 0;
166 /* sctpimpguide Section 2.12.2
167 * If the 'T5-shutdown-guard' timer is used, it SHOULD be set to the
168 * recommended value of 5 times 'RTO.Max'.
170 asoc->timeouts[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD]
171 = 5 * asoc->rto_max;
173 asoc->timeouts[SCTP_EVENT_TIMEOUT_HEARTBEAT] = 0;
174 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] = asoc->sackdelay;
175 asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE] =
176 (unsigned long)sp->autoclose * HZ;
178 /* Initializes the timers */
179 for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i)
180 setup_timer(&asoc->timers[i], sctp_timer_events[i],
181 (unsigned long)asoc);
183 /* Pull default initialization values from the sock options.
184 * Note: This assumes that the values have already been
185 * validated in the sock.
187 asoc->c.sinit_max_instreams = sp->initmsg.sinit_max_instreams;
188 asoc->c.sinit_num_ostreams = sp->initmsg.sinit_num_ostreams;
189 asoc->max_init_attempts = sp->initmsg.sinit_max_attempts;
191 asoc->max_init_timeo =
192 msecs_to_jiffies(sp->initmsg.sinit_max_init_timeo);
194 /* Allocate storage for the ssnmap after the inbound and outbound
195 * streams have been negotiated during Init.
197 asoc->ssnmap = NULL;
199 /* Set the local window size for receive.
200 * This is also the rcvbuf space per association.
201 * RFC 6 - A SCTP receiver MUST be able to receive a minimum of
202 * 1500 bytes in one SCTP packet.
204 if ((sk->sk_rcvbuf/2) < SCTP_DEFAULT_MINWINDOW)
205 asoc->rwnd = SCTP_DEFAULT_MINWINDOW;
206 else
207 asoc->rwnd = sk->sk_rcvbuf/2;
209 asoc->a_rwnd = asoc->rwnd;
211 asoc->rwnd_over = 0;
212 asoc->rwnd_press = 0;
214 /* Use my own max window until I learn something better. */
215 asoc->peer.rwnd = SCTP_DEFAULT_MAXWINDOW;
217 /* Set the sndbuf size for transmit. */
218 asoc->sndbuf_used = 0;
220 /* Initialize the receive memory counter */
221 atomic_set(&asoc->rmem_alloc, 0);
223 init_waitqueue_head(&asoc->wait);
225 asoc->c.my_vtag = sctp_generate_tag(ep);
226 asoc->peer.i.init_tag = 0; /* INIT needs a vtag of 0. */
227 asoc->c.peer_vtag = 0;
228 asoc->c.my_ttag = 0;
229 asoc->c.peer_ttag = 0;
230 asoc->c.my_port = ep->base.bind_addr.port;
232 asoc->c.initial_tsn = sctp_generate_tsn(ep);
234 asoc->next_tsn = asoc->c.initial_tsn;
236 asoc->ctsn_ack_point = asoc->next_tsn - 1;
237 asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
238 asoc->highest_sacked = asoc->ctsn_ack_point;
239 asoc->last_cwr_tsn = asoc->ctsn_ack_point;
240 asoc->unack_data = 0;
242 /* ADDIP Section 4.1 Asconf Chunk Procedures
244 * When an endpoint has an ASCONF signaled change to be sent to the
245 * remote endpoint it should do the following:
246 * ...
247 * A2) a serial number should be assigned to the chunk. The serial
248 * number SHOULD be a monotonically increasing number. The serial
249 * numbers SHOULD be initialized at the start of the
250 * association to the same value as the initial TSN.
252 asoc->addip_serial = asoc->c.initial_tsn;
254 INIT_LIST_HEAD(&asoc->addip_chunk_list);
255 INIT_LIST_HEAD(&asoc->asconf_ack_list);
257 /* Make an empty list of remote transport addresses. */
258 INIT_LIST_HEAD(&asoc->peer.transport_addr_list);
259 asoc->peer.transport_count = 0;
261 /* RFC 2960 5.1 Normal Establishment of an Association
263 * After the reception of the first data chunk in an
264 * association the endpoint must immediately respond with a
265 * sack to acknowledge the data chunk. Subsequent
266 * acknowledgements should be done as described in Section
267 * 6.2.
269 * [We implement this by telling a new association that it
270 * already received one packet.]
272 asoc->peer.sack_needed = 1;
273 asoc->peer.sack_cnt = 0;
275 /* Assume that the peer will tell us if he recognizes ASCONF
276 * as part of INIT exchange.
277 * The sctp_addip_noauth option is there for backward compatibilty
278 * and will revert old behavior.
280 asoc->peer.asconf_capable = 0;
281 if (sctp_addip_noauth)
282 asoc->peer.asconf_capable = 1;
284 /* Create an input queue. */
285 sctp_inq_init(&asoc->base.inqueue);
286 sctp_inq_set_th_handler(&asoc->base.inqueue, sctp_assoc_bh_rcv);
288 /* Create an output queue. */
289 sctp_outq_init(asoc, &asoc->outqueue);
291 if (!sctp_ulpq_init(&asoc->ulpq, asoc))
292 goto fail_init;
294 memset(&asoc->peer.tsn_map, 0, sizeof(struct sctp_tsnmap));
296 asoc->need_ecne = 0;
298 asoc->assoc_id = 0;
300 /* Assume that peer would support both address types unless we are
301 * told otherwise.
303 asoc->peer.ipv4_address = 1;
304 if (asoc->base.sk->sk_family == PF_INET6)
305 asoc->peer.ipv6_address = 1;
306 INIT_LIST_HEAD(&asoc->asocs);
308 asoc->autoclose = sp->autoclose;
310 asoc->default_stream = sp->default_stream;
311 asoc->default_ppid = sp->default_ppid;
312 asoc->default_flags = sp->default_flags;
313 asoc->default_context = sp->default_context;
314 asoc->default_timetolive = sp->default_timetolive;
315 asoc->default_rcv_context = sp->default_rcv_context;
317 /* AUTH related initializations */
318 INIT_LIST_HEAD(&asoc->endpoint_shared_keys);
319 err = sctp_auth_asoc_copy_shkeys(ep, asoc, gfp);
320 if (err)
321 goto fail_init;
323 asoc->active_key_id = ep->active_key_id;
324 asoc->asoc_shared_key = NULL;
326 asoc->default_hmac_id = 0;
327 /* Save the hmacs and chunks list into this association */
328 if (ep->auth_hmacs_list)
329 memcpy(asoc->c.auth_hmacs, ep->auth_hmacs_list,
330 ntohs(ep->auth_hmacs_list->param_hdr.length));
331 if (ep->auth_chunk_list)
332 memcpy(asoc->c.auth_chunks, ep->auth_chunk_list,
333 ntohs(ep->auth_chunk_list->param_hdr.length));
335 /* Get the AUTH random number for this association */
336 p = (sctp_paramhdr_t *)asoc->c.auth_random;
337 p->type = SCTP_PARAM_RANDOM;
338 p->length = htons(sizeof(sctp_paramhdr_t) + SCTP_AUTH_RANDOM_LENGTH);
339 get_random_bytes(p+1, SCTP_AUTH_RANDOM_LENGTH);
341 return asoc;
343 fail_init:
344 sctp_endpoint_put(asoc->ep);
345 sock_put(asoc->base.sk);
346 return NULL;
349 /* Allocate and initialize a new association */
350 struct sctp_association *sctp_association_new(const struct sctp_endpoint *ep,
351 const struct sock *sk,
352 sctp_scope_t scope,
353 gfp_t gfp)
355 struct sctp_association *asoc;
357 asoc = t_new(struct sctp_association, gfp);
358 if (!asoc)
359 goto fail;
361 if (!sctp_association_init(asoc, ep, sk, scope, gfp))
362 goto fail_init;
364 asoc->base.malloced = 1;
365 SCTP_DBG_OBJCNT_INC(assoc);
366 SCTP_DEBUG_PRINTK("Created asoc %p\n", asoc);
368 return asoc;
370 fail_init:
371 kfree(asoc);
372 fail:
373 return NULL;
376 /* Free this association if possible. There may still be users, so
377 * the actual deallocation may be delayed.
379 void sctp_association_free(struct sctp_association *asoc)
381 struct sock *sk = asoc->base.sk;
382 struct sctp_transport *transport;
383 struct list_head *pos, *temp;
384 int i;
386 /* Only real associations count against the endpoint, so
387 * don't bother for if this is a temporary association.
389 if (!asoc->temp) {
390 list_del(&asoc->asocs);
392 /* Decrement the backlog value for a TCP-style listening
393 * socket.
395 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
396 sk->sk_ack_backlog--;
399 /* Mark as dead, so other users can know this structure is
400 * going away.
402 asoc->base.dead = 1;
404 /* Dispose of any data lying around in the outqueue. */
405 sctp_outq_free(&asoc->outqueue);
407 /* Dispose of any pending messages for the upper layer. */
408 sctp_ulpq_free(&asoc->ulpq);
410 /* Dispose of any pending chunks on the inqueue. */
411 sctp_inq_free(&asoc->base.inqueue);
413 sctp_tsnmap_free(&asoc->peer.tsn_map);
415 /* Free ssnmap storage. */
416 sctp_ssnmap_free(asoc->ssnmap);
418 /* Clean up the bound address list. */
419 sctp_bind_addr_free(&asoc->base.bind_addr);
421 /* Do we need to go through all of our timers and
422 * delete them? To be safe we will try to delete all, but we
423 * should be able to go through and make a guess based
424 * on our state.
426 for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i) {
427 if (timer_pending(&asoc->timers[i]) &&
428 del_timer(&asoc->timers[i]))
429 sctp_association_put(asoc);
432 /* Free peer's cached cookie. */
433 kfree(asoc->peer.cookie);
434 kfree(asoc->peer.peer_random);
435 kfree(asoc->peer.peer_chunks);
436 kfree(asoc->peer.peer_hmacs);
438 /* Release the transport structures. */
439 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
440 transport = list_entry(pos, struct sctp_transport, transports);
441 list_del(pos);
442 sctp_transport_free(transport);
445 asoc->peer.transport_count = 0;
447 sctp_asconf_queue_teardown(asoc);
449 /* AUTH - Free the endpoint shared keys */
450 sctp_auth_destroy_keys(&asoc->endpoint_shared_keys);
452 /* AUTH - Free the association shared key */
453 sctp_auth_key_put(asoc->asoc_shared_key);
455 sctp_association_put(asoc);
458 /* Cleanup and free up an association. */
459 static void sctp_association_destroy(struct sctp_association *asoc)
461 SCTP_ASSERT(asoc->base.dead, "Assoc is not dead", return);
463 sctp_endpoint_put(asoc->ep);
464 sock_put(asoc->base.sk);
466 if (asoc->assoc_id != 0) {
467 spin_lock_bh(&sctp_assocs_id_lock);
468 idr_remove(&sctp_assocs_id, asoc->assoc_id);
469 spin_unlock_bh(&sctp_assocs_id_lock);
472 WARN_ON(atomic_read(&asoc->rmem_alloc));
474 if (asoc->base.malloced) {
475 kfree(asoc);
476 SCTP_DBG_OBJCNT_DEC(assoc);
480 /* Change the primary destination address for the peer. */
481 void sctp_assoc_set_primary(struct sctp_association *asoc,
482 struct sctp_transport *transport)
484 int changeover = 0;
486 /* it's a changeover only if we already have a primary path
487 * that we are changing
489 if (asoc->peer.primary_path != NULL &&
490 asoc->peer.primary_path != transport)
491 changeover = 1 ;
493 asoc->peer.primary_path = transport;
495 /* Set a default msg_name for events. */
496 memcpy(&asoc->peer.primary_addr, &transport->ipaddr,
497 sizeof(union sctp_addr));
499 /* If the primary path is changing, assume that the
500 * user wants to use this new path.
502 if ((transport->state == SCTP_ACTIVE) ||
503 (transport->state == SCTP_UNKNOWN))
504 asoc->peer.active_path = transport;
507 * SFR-CACC algorithm:
508 * Upon the receipt of a request to change the primary
509 * destination address, on the data structure for the new
510 * primary destination, the sender MUST do the following:
512 * 1) If CHANGEOVER_ACTIVE is set, then there was a switch
513 * to this destination address earlier. The sender MUST set
514 * CYCLING_CHANGEOVER to indicate that this switch is a
515 * double switch to the same destination address.
517 * Really, only bother is we have data queued or outstanding on
518 * the association.
520 if (!asoc->outqueue.outstanding_bytes && !asoc->outqueue.out_qlen)
521 return;
523 if (transport->cacc.changeover_active)
524 transport->cacc.cycling_changeover = changeover;
526 /* 2) The sender MUST set CHANGEOVER_ACTIVE to indicate that
527 * a changeover has occurred.
529 transport->cacc.changeover_active = changeover;
531 /* 3) The sender MUST store the next TSN to be sent in
532 * next_tsn_at_change.
534 transport->cacc.next_tsn_at_change = asoc->next_tsn;
537 /* Remove a transport from an association. */
538 void sctp_assoc_rm_peer(struct sctp_association *asoc,
539 struct sctp_transport *peer)
541 struct list_head *pos;
542 struct sctp_transport *transport;
544 SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_rm_peer:association %p addr: ",
545 " port: %d\n",
546 asoc,
547 (&peer->ipaddr),
548 ntohs(peer->ipaddr.v4.sin_port));
550 /* If we are to remove the current retran_path, update it
551 * to the next peer before removing this peer from the list.
553 if (asoc->peer.retran_path == peer)
554 sctp_assoc_update_retran_path(asoc);
556 /* Remove this peer from the list. */
557 list_del(&peer->transports);
559 /* Get the first transport of asoc. */
560 pos = asoc->peer.transport_addr_list.next;
561 transport = list_entry(pos, struct sctp_transport, transports);
563 /* Update any entries that match the peer to be deleted. */
564 if (asoc->peer.primary_path == peer)
565 sctp_assoc_set_primary(asoc, transport);
566 if (asoc->peer.active_path == peer)
567 asoc->peer.active_path = transport;
568 if (asoc->peer.retran_path == peer)
569 asoc->peer.retran_path = transport;
570 if (asoc->peer.last_data_from == peer)
571 asoc->peer.last_data_from = transport;
573 /* If we remove the transport an INIT was last sent to, set it to
574 * NULL. Combined with the update of the retran path above, this
575 * will cause the next INIT to be sent to the next available
576 * transport, maintaining the cycle.
578 if (asoc->init_last_sent_to == peer)
579 asoc->init_last_sent_to = NULL;
581 /* If we remove the transport an SHUTDOWN was last sent to, set it
582 * to NULL. Combined with the update of the retran path above, this
583 * will cause the next SHUTDOWN to be sent to the next available
584 * transport, maintaining the cycle.
586 if (asoc->shutdown_last_sent_to == peer)
587 asoc->shutdown_last_sent_to = NULL;
589 /* If we remove the transport an ASCONF was last sent to, set it to
590 * NULL.
592 if (asoc->addip_last_asconf &&
593 asoc->addip_last_asconf->transport == peer)
594 asoc->addip_last_asconf->transport = NULL;
596 /* If we have something on the transmitted list, we have to
597 * save it off. The best place is the active path.
599 if (!list_empty(&peer->transmitted)) {
600 struct sctp_transport *active = asoc->peer.active_path;
601 struct sctp_chunk *ch;
603 /* Reset the transport of each chunk on this list */
604 list_for_each_entry(ch, &peer->transmitted,
605 transmitted_list) {
606 ch->transport = NULL;
607 ch->rtt_in_progress = 0;
610 list_splice_tail_init(&peer->transmitted,
611 &active->transmitted);
613 /* Start a T3 timer here in case it wasn't running so
614 * that these migrated packets have a chance to get
615 * retrnasmitted.
617 if (!timer_pending(&active->T3_rtx_timer))
618 if (!mod_timer(&active->T3_rtx_timer,
619 jiffies + active->rto))
620 sctp_transport_hold(active);
623 asoc->peer.transport_count--;
625 sctp_transport_free(peer);
628 /* Add a transport address to an association. */
629 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc,
630 const union sctp_addr *addr,
631 const gfp_t gfp,
632 const int peer_state)
634 struct sctp_transport *peer;
635 struct sctp_sock *sp;
636 unsigned short port;
638 sp = sctp_sk(asoc->base.sk);
640 /* AF_INET and AF_INET6 share common port field. */
641 port = ntohs(addr->v4.sin_port);
643 SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_add_peer:association %p addr: ",
644 " port: %d state:%d\n",
645 asoc,
646 addr,
647 port,
648 peer_state);
650 /* Set the port if it has not been set yet. */
651 if (0 == asoc->peer.port)
652 asoc->peer.port = port;
654 /* Check to see if this is a duplicate. */
655 peer = sctp_assoc_lookup_paddr(asoc, addr);
656 if (peer) {
657 /* An UNKNOWN state is only set on transports added by
658 * user in sctp_connectx() call. Such transports should be
659 * considered CONFIRMED per RFC 4960, Section 5.4.
661 if (peer->state == SCTP_UNKNOWN) {
662 peer->state = SCTP_ACTIVE;
664 return peer;
667 peer = sctp_transport_new(addr, gfp);
668 if (!peer)
669 return NULL;
671 sctp_transport_set_owner(peer, asoc);
673 /* Initialize the peer's heartbeat interval based on the
674 * association configured value.
676 peer->hbinterval = asoc->hbinterval;
678 /* Set the path max_retrans. */
679 peer->pathmaxrxt = asoc->pathmaxrxt;
681 /* Initialize the peer's SACK delay timeout based on the
682 * association configured value.
684 peer->sackdelay = asoc->sackdelay;
685 peer->sackfreq = asoc->sackfreq;
687 /* Enable/disable heartbeat, SACK delay, and path MTU discovery
688 * based on association setting.
690 peer->param_flags = asoc->param_flags;
692 sctp_transport_route(peer, NULL, sp);
694 /* Initialize the pmtu of the transport. */
695 if (peer->param_flags & SPP_PMTUD_DISABLE) {
696 if (asoc->pathmtu)
697 peer->pathmtu = asoc->pathmtu;
698 else
699 peer->pathmtu = SCTP_DEFAULT_MAXSEGMENT;
702 /* If this is the first transport addr on this association,
703 * initialize the association PMTU to the peer's PMTU.
704 * If not and the current association PMTU is higher than the new
705 * peer's PMTU, reset the association PMTU to the new peer's PMTU.
707 if (asoc->pathmtu)
708 asoc->pathmtu = min_t(int, peer->pathmtu, asoc->pathmtu);
709 else
710 asoc->pathmtu = peer->pathmtu;
712 SCTP_DEBUG_PRINTK("sctp_assoc_add_peer:association %p PMTU set to "
713 "%d\n", asoc, asoc->pathmtu);
714 peer->pmtu_pending = 0;
716 asoc->frag_point = sctp_frag_point(asoc, asoc->pathmtu);
718 /* The asoc->peer.port might not be meaningful yet, but
719 * initialize the packet structure anyway.
721 sctp_packet_init(&peer->packet, peer, asoc->base.bind_addr.port,
722 asoc->peer.port);
724 /* 7.2.1 Slow-Start
726 * o The initial cwnd before DATA transmission or after a sufficiently
727 * long idle period MUST be set to
728 * min(4*MTU, max(2*MTU, 4380 bytes))
730 * o The initial value of ssthresh MAY be arbitrarily high
731 * (for example, implementations MAY use the size of the
732 * receiver advertised window).
734 peer->cwnd = min(4*asoc->pathmtu, max_t(__u32, 2*asoc->pathmtu, 4380));
736 /* At this point, we may not have the receiver's advertised window,
737 * so initialize ssthresh to the default value and it will be set
738 * later when we process the INIT.
740 peer->ssthresh = SCTP_DEFAULT_MAXWINDOW;
742 peer->partial_bytes_acked = 0;
743 peer->flight_size = 0;
744 peer->burst_limited = 0;
746 /* Set the transport's RTO.initial value */
747 peer->rto = asoc->rto_initial;
749 /* Set the peer's active state. */
750 peer->state = peer_state;
752 /* Attach the remote transport to our asoc. */
753 list_add_tail(&peer->transports, &asoc->peer.transport_addr_list);
754 asoc->peer.transport_count++;
756 /* If we do not yet have a primary path, set one. */
757 if (!asoc->peer.primary_path) {
758 sctp_assoc_set_primary(asoc, peer);
759 asoc->peer.retran_path = peer;
762 if (asoc->peer.active_path == asoc->peer.retran_path &&
763 peer->state != SCTP_UNCONFIRMED) {
764 asoc->peer.retran_path = peer;
767 return peer;
770 /* Delete a transport address from an association. */
771 void sctp_assoc_del_peer(struct sctp_association *asoc,
772 const union sctp_addr *addr)
774 struct list_head *pos;
775 struct list_head *temp;
776 struct sctp_transport *transport;
778 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
779 transport = list_entry(pos, struct sctp_transport, transports);
780 if (sctp_cmp_addr_exact(addr, &transport->ipaddr)) {
781 /* Do book keeping for removing the peer and free it. */
782 sctp_assoc_rm_peer(asoc, transport);
783 break;
788 /* Lookup a transport by address. */
789 struct sctp_transport *sctp_assoc_lookup_paddr(
790 const struct sctp_association *asoc,
791 const union sctp_addr *address)
793 struct sctp_transport *t;
795 /* Cycle through all transports searching for a peer address. */
797 list_for_each_entry(t, &asoc->peer.transport_addr_list,
798 transports) {
799 if (sctp_cmp_addr_exact(address, &t->ipaddr))
800 return t;
803 return NULL;
806 /* Remove all transports except a give one */
807 void sctp_assoc_del_nonprimary_peers(struct sctp_association *asoc,
808 struct sctp_transport *primary)
810 struct sctp_transport *temp;
811 struct sctp_transport *t;
813 list_for_each_entry_safe(t, temp, &asoc->peer.transport_addr_list,
814 transports) {
815 /* if the current transport is not the primary one, delete it */
816 if (t != primary)
817 sctp_assoc_rm_peer(asoc, t);
821 /* Engage in transport control operations.
822 * Mark the transport up or down and send a notification to the user.
823 * Select and update the new active and retran paths.
825 void sctp_assoc_control_transport(struct sctp_association *asoc,
826 struct sctp_transport *transport,
827 sctp_transport_cmd_t command,
828 sctp_sn_error_t error)
830 struct sctp_transport *t = NULL;
831 struct sctp_transport *first;
832 struct sctp_transport *second;
833 struct sctp_ulpevent *event;
834 struct sockaddr_storage addr;
835 int spc_state = 0;
837 /* Record the transition on the transport. */
838 switch (command) {
839 case SCTP_TRANSPORT_UP:
840 /* If we are moving from UNCONFIRMED state due
841 * to heartbeat success, report the SCTP_ADDR_CONFIRMED
842 * state to the user, otherwise report SCTP_ADDR_AVAILABLE.
844 if (SCTP_UNCONFIRMED == transport->state &&
845 SCTP_HEARTBEAT_SUCCESS == error)
846 spc_state = SCTP_ADDR_CONFIRMED;
847 else
848 spc_state = SCTP_ADDR_AVAILABLE;
849 transport->state = SCTP_ACTIVE;
850 break;
852 case SCTP_TRANSPORT_DOWN:
853 /* If the transport was never confirmed, do not transition it
854 * to inactive state. Also, release the cached route since
855 * there may be a better route next time.
857 if (transport->state != SCTP_UNCONFIRMED)
858 transport->state = SCTP_INACTIVE;
859 else {
860 dst_release(transport->dst);
861 transport->dst = NULL;
864 spc_state = SCTP_ADDR_UNREACHABLE;
865 break;
867 default:
868 return;
871 /* Generate and send a SCTP_PEER_ADDR_CHANGE notification to the
872 * user.
874 memset(&addr, 0, sizeof(struct sockaddr_storage));
875 memcpy(&addr, &transport->ipaddr, transport->af_specific->sockaddr_len);
876 event = sctp_ulpevent_make_peer_addr_change(asoc, &addr,
877 0, spc_state, error, GFP_ATOMIC);
878 if (event)
879 sctp_ulpq_tail_event(&asoc->ulpq, event);
881 /* Select new active and retran paths. */
883 /* Look for the two most recently used active transports.
885 * This code produces the wrong ordering whenever jiffies
886 * rolls over, but we still get usable transports, so we don't
887 * worry about it.
889 first = NULL; second = NULL;
891 list_for_each_entry(t, &asoc->peer.transport_addr_list,
892 transports) {
894 if ((t->state == SCTP_INACTIVE) ||
895 (t->state == SCTP_UNCONFIRMED))
896 continue;
897 if (!first || t->last_time_heard > first->last_time_heard) {
898 second = first;
899 first = t;
901 if (!second || t->last_time_heard > second->last_time_heard)
902 second = t;
905 /* RFC 2960 6.4 Multi-Homed SCTP Endpoints
907 * By default, an endpoint should always transmit to the
908 * primary path, unless the SCTP user explicitly specifies the
909 * destination transport address (and possibly source
910 * transport address) to use.
912 * [If the primary is active but not most recent, bump the most
913 * recently used transport.]
915 if (((asoc->peer.primary_path->state == SCTP_ACTIVE) ||
916 (asoc->peer.primary_path->state == SCTP_UNKNOWN)) &&
917 first != asoc->peer.primary_path) {
918 second = first;
919 first = asoc->peer.primary_path;
922 /* If we failed to find a usable transport, just camp on the
923 * primary, even if it is inactive.
925 if (!first) {
926 first = asoc->peer.primary_path;
927 second = asoc->peer.primary_path;
930 /* Set the active and retran transports. */
931 asoc->peer.active_path = first;
932 asoc->peer.retran_path = second;
935 /* Hold a reference to an association. */
936 void sctp_association_hold(struct sctp_association *asoc)
938 atomic_inc(&asoc->base.refcnt);
941 /* Release a reference to an association and cleanup
942 * if there are no more references.
944 void sctp_association_put(struct sctp_association *asoc)
946 if (atomic_dec_and_test(&asoc->base.refcnt))
947 sctp_association_destroy(asoc);
950 /* Allocate the next TSN, Transmission Sequence Number, for the given
951 * association.
953 __u32 sctp_association_get_next_tsn(struct sctp_association *asoc)
955 /* From Section 1.6 Serial Number Arithmetic:
956 * Transmission Sequence Numbers wrap around when they reach
957 * 2**32 - 1. That is, the next TSN a DATA chunk MUST use
958 * after transmitting TSN = 2*32 - 1 is TSN = 0.
960 __u32 retval = asoc->next_tsn;
961 asoc->next_tsn++;
962 asoc->unack_data++;
964 return retval;
967 /* Compare two addresses to see if they match. Wildcard addresses
968 * only match themselves.
970 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
971 const union sctp_addr *ss2)
973 struct sctp_af *af;
975 af = sctp_get_af_specific(ss1->sa.sa_family);
976 if (unlikely(!af))
977 return 0;
979 return af->cmp_addr(ss1, ss2);
982 /* Return an ecne chunk to get prepended to a packet.
983 * Note: We are sly and return a shared, prealloced chunk. FIXME:
984 * No we don't, but we could/should.
986 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc)
988 struct sctp_chunk *chunk;
990 /* Send ECNE if needed.
991 * Not being able to allocate a chunk here is not deadly.
993 if (asoc->need_ecne)
994 chunk = sctp_make_ecne(asoc, asoc->last_ecne_tsn);
995 else
996 chunk = NULL;
998 return chunk;
1002 * Find which transport this TSN was sent on.
1004 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *asoc,
1005 __u32 tsn)
1007 struct sctp_transport *active;
1008 struct sctp_transport *match;
1009 struct sctp_transport *transport;
1010 struct sctp_chunk *chunk;
1011 __be32 key = htonl(tsn);
1013 match = NULL;
1016 * FIXME: In general, find a more efficient data structure for
1017 * searching.
1021 * The general strategy is to search each transport's transmitted
1022 * list. Return which transport this TSN lives on.
1024 * Let's be hopeful and check the active_path first.
1025 * Another optimization would be to know if there is only one
1026 * outbound path and not have to look for the TSN at all.
1030 active = asoc->peer.active_path;
1032 list_for_each_entry(chunk, &active->transmitted,
1033 transmitted_list) {
1035 if (key == chunk->subh.data_hdr->tsn) {
1036 match = active;
1037 goto out;
1041 /* If not found, go search all the other transports. */
1042 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
1043 transports) {
1045 if (transport == active)
1046 break;
1047 list_for_each_entry(chunk, &transport->transmitted,
1048 transmitted_list) {
1049 if (key == chunk->subh.data_hdr->tsn) {
1050 match = transport;
1051 goto out;
1055 out:
1056 return match;
1059 /* Is this the association we are looking for? */
1060 struct sctp_transport *sctp_assoc_is_match(struct sctp_association *asoc,
1061 const union sctp_addr *laddr,
1062 const union sctp_addr *paddr)
1064 struct sctp_transport *transport;
1066 if ((htons(asoc->base.bind_addr.port) == laddr->v4.sin_port) &&
1067 (htons(asoc->peer.port) == paddr->v4.sin_port)) {
1068 transport = sctp_assoc_lookup_paddr(asoc, paddr);
1069 if (!transport)
1070 goto out;
1072 if (sctp_bind_addr_match(&asoc->base.bind_addr, laddr,
1073 sctp_sk(asoc->base.sk)))
1074 goto out;
1076 transport = NULL;
1078 out:
1079 return transport;
1082 /* Do delayed input processing. This is scheduled by sctp_rcv(). */
1083 static void sctp_assoc_bh_rcv(struct work_struct *work)
1085 struct sctp_association *asoc =
1086 container_of(work, struct sctp_association,
1087 base.inqueue.immediate);
1088 struct sctp_endpoint *ep;
1089 struct sctp_chunk *chunk;
1090 struct sctp_inq *inqueue;
1091 int state;
1092 sctp_subtype_t subtype;
1093 int error = 0;
1095 /* The association should be held so we should be safe. */
1096 ep = asoc->ep;
1098 inqueue = &asoc->base.inqueue;
1099 sctp_association_hold(asoc);
1100 while (NULL != (chunk = sctp_inq_pop(inqueue))) {
1101 state = asoc->state;
1102 subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type);
1104 /* SCTP-AUTH, Section 6.3:
1105 * The receiver has a list of chunk types which it expects
1106 * to be received only after an AUTH-chunk. This list has
1107 * been sent to the peer during the association setup. It
1108 * MUST silently discard these chunks if they are not placed
1109 * after an AUTH chunk in the packet.
1111 if (sctp_auth_recv_cid(subtype.chunk, asoc) && !chunk->auth)
1112 continue;
1114 /* Remember where the last DATA chunk came from so we
1115 * know where to send the SACK.
1117 if (sctp_chunk_is_data(chunk))
1118 asoc->peer.last_data_from = chunk->transport;
1119 else
1120 SCTP_INC_STATS(SCTP_MIB_INCTRLCHUNKS);
1122 if (chunk->transport)
1123 chunk->transport->last_time_heard = jiffies;
1125 /* Run through the state machine. */
1126 error = sctp_do_sm(SCTP_EVENT_T_CHUNK, subtype,
1127 state, ep, asoc, chunk, GFP_ATOMIC);
1129 /* Check to see if the association is freed in response to
1130 * the incoming chunk. If so, get out of the while loop.
1132 if (asoc->base.dead)
1133 break;
1135 /* If there is an error on chunk, discard this packet. */
1136 if (error && chunk)
1137 chunk->pdiscard = 1;
1139 sctp_association_put(asoc);
1142 /* This routine moves an association from its old sk to a new sk. */
1143 void sctp_assoc_migrate(struct sctp_association *assoc, struct sock *newsk)
1145 struct sctp_sock *newsp = sctp_sk(newsk);
1146 struct sock *oldsk = assoc->base.sk;
1148 /* Delete the association from the old endpoint's list of
1149 * associations.
1151 list_del_init(&assoc->asocs);
1153 /* Decrement the backlog value for a TCP-style socket. */
1154 if (sctp_style(oldsk, TCP))
1155 oldsk->sk_ack_backlog--;
1157 /* Release references to the old endpoint and the sock. */
1158 sctp_endpoint_put(assoc->ep);
1159 sock_put(assoc->base.sk);
1161 /* Get a reference to the new endpoint. */
1162 assoc->ep = newsp->ep;
1163 sctp_endpoint_hold(assoc->ep);
1165 /* Get a reference to the new sock. */
1166 assoc->base.sk = newsk;
1167 sock_hold(assoc->base.sk);
1169 /* Add the association to the new endpoint's list of associations. */
1170 sctp_endpoint_add_asoc(newsp->ep, assoc);
1173 /* Update an association (possibly from unexpected COOKIE-ECHO processing). */
1174 void sctp_assoc_update(struct sctp_association *asoc,
1175 struct sctp_association *new)
1177 struct sctp_transport *trans;
1178 struct list_head *pos, *temp;
1180 /* Copy in new parameters of peer. */
1181 asoc->c = new->c;
1182 asoc->peer.rwnd = new->peer.rwnd;
1183 asoc->peer.sack_needed = new->peer.sack_needed;
1184 asoc->peer.i = new->peer.i;
1185 sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
1186 asoc->peer.i.initial_tsn, GFP_ATOMIC);
1188 /* Remove any peer addresses not present in the new association. */
1189 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
1190 trans = list_entry(pos, struct sctp_transport, transports);
1191 if (!sctp_assoc_lookup_paddr(new, &trans->ipaddr)) {
1192 sctp_assoc_rm_peer(asoc, trans);
1193 continue;
1196 if (asoc->state >= SCTP_STATE_ESTABLISHED)
1197 sctp_transport_reset(trans);
1200 /* If the case is A (association restart), use
1201 * initial_tsn as next_tsn. If the case is B, use
1202 * current next_tsn in case data sent to peer
1203 * has been discarded and needs retransmission.
1205 if (asoc->state >= SCTP_STATE_ESTABLISHED) {
1206 asoc->next_tsn = new->next_tsn;
1207 asoc->ctsn_ack_point = new->ctsn_ack_point;
1208 asoc->adv_peer_ack_point = new->adv_peer_ack_point;
1210 /* Reinitialize SSN for both local streams
1211 * and peer's streams.
1213 sctp_ssnmap_clear(asoc->ssnmap);
1215 /* Flush the ULP reassembly and ordered queue.
1216 * Any data there will now be stale and will
1217 * cause problems.
1219 sctp_ulpq_flush(&asoc->ulpq);
1221 /* reset the overall association error count so
1222 * that the restarted association doesn't get torn
1223 * down on the next retransmission timer.
1225 asoc->overall_error_count = 0;
1227 } else {
1228 /* Add any peer addresses from the new association. */
1229 list_for_each_entry(trans, &new->peer.transport_addr_list,
1230 transports) {
1231 if (!sctp_assoc_lookup_paddr(asoc, &trans->ipaddr))
1232 sctp_assoc_add_peer(asoc, &trans->ipaddr,
1233 GFP_ATOMIC, trans->state);
1236 asoc->ctsn_ack_point = asoc->next_tsn - 1;
1237 asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
1238 if (!asoc->ssnmap) {
1239 /* Move the ssnmap. */
1240 asoc->ssnmap = new->ssnmap;
1241 new->ssnmap = NULL;
1244 if (!asoc->assoc_id) {
1245 /* get a new association id since we don't have one
1246 * yet.
1248 sctp_assoc_set_id(asoc, GFP_ATOMIC);
1252 /* SCTP-AUTH: Save the peer parameters from the new assocaitions
1253 * and also move the association shared keys over
1255 kfree(asoc->peer.peer_random);
1256 asoc->peer.peer_random = new->peer.peer_random;
1257 new->peer.peer_random = NULL;
1259 kfree(asoc->peer.peer_chunks);
1260 asoc->peer.peer_chunks = new->peer.peer_chunks;
1261 new->peer.peer_chunks = NULL;
1263 kfree(asoc->peer.peer_hmacs);
1264 asoc->peer.peer_hmacs = new->peer.peer_hmacs;
1265 new->peer.peer_hmacs = NULL;
1267 sctp_auth_key_put(asoc->asoc_shared_key);
1268 sctp_auth_asoc_init_active_key(asoc, GFP_ATOMIC);
1271 /* Update the retran path for sending a retransmitted packet.
1272 * Round-robin through the active transports, else round-robin
1273 * through the inactive transports as this is the next best thing
1274 * we can try.
1276 void sctp_assoc_update_retran_path(struct sctp_association *asoc)
1278 struct sctp_transport *t, *next;
1279 struct list_head *head = &asoc->peer.transport_addr_list;
1280 struct list_head *pos;
1282 if (asoc->peer.transport_count == 1)
1283 return;
1285 /* Find the next transport in a round-robin fashion. */
1286 t = asoc->peer.retran_path;
1287 pos = &t->transports;
1288 next = NULL;
1290 while (1) {
1291 /* Skip the head. */
1292 if (pos->next == head)
1293 pos = head->next;
1294 else
1295 pos = pos->next;
1297 t = list_entry(pos, struct sctp_transport, transports);
1299 /* We have exhausted the list, but didn't find any
1300 * other active transports. If so, use the next
1301 * transport.
1303 if (t == asoc->peer.retran_path) {
1304 t = next;
1305 break;
1308 /* Try to find an active transport. */
1310 if ((t->state == SCTP_ACTIVE) ||
1311 (t->state == SCTP_UNKNOWN)) {
1312 break;
1313 } else {
1314 /* Keep track of the next transport in case
1315 * we don't find any active transport.
1317 if (t->state != SCTP_UNCONFIRMED && !next)
1318 next = t;
1322 if (t)
1323 asoc->peer.retran_path = t;
1324 else
1325 t = asoc->peer.retran_path;
1327 SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_update_retran_path:association"
1328 " %p addr: ",
1329 " port: %d\n",
1330 asoc,
1331 (&t->ipaddr),
1332 ntohs(t->ipaddr.v4.sin_port));
1335 /* Choose the transport for sending retransmit packet. */
1336 struct sctp_transport *sctp_assoc_choose_alter_transport(
1337 struct sctp_association *asoc, struct sctp_transport *last_sent_to)
1339 /* If this is the first time packet is sent, use the active path,
1340 * else use the retran path. If the last packet was sent over the
1341 * retran path, update the retran path and use it.
1343 if (!last_sent_to)
1344 return asoc->peer.active_path;
1345 else {
1346 if (last_sent_to == asoc->peer.retran_path)
1347 sctp_assoc_update_retran_path(asoc);
1348 return asoc->peer.retran_path;
1352 /* Update the association's pmtu and frag_point by going through all the
1353 * transports. This routine is called when a transport's PMTU has changed.
1355 void sctp_assoc_sync_pmtu(struct sctp_association *asoc)
1357 struct sctp_transport *t;
1358 __u32 pmtu = 0;
1360 if (!asoc)
1361 return;
1363 /* Get the lowest pmtu of all the transports. */
1364 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1365 transports) {
1366 if (t->pmtu_pending && t->dst) {
1367 sctp_transport_update_pmtu(t, dst_mtu(t->dst));
1368 t->pmtu_pending = 0;
1370 if (!pmtu || (t->pathmtu < pmtu))
1371 pmtu = t->pathmtu;
1374 if (pmtu) {
1375 asoc->pathmtu = pmtu;
1376 asoc->frag_point = sctp_frag_point(asoc, pmtu);
1379 SCTP_DEBUG_PRINTK("%s: asoc:%p, pmtu:%d, frag_point:%d\n",
1380 __func__, asoc, asoc->pathmtu, asoc->frag_point);
1383 /* Should we send a SACK to update our peer? */
1384 static inline int sctp_peer_needs_update(struct sctp_association *asoc)
1386 switch (asoc->state) {
1387 case SCTP_STATE_ESTABLISHED:
1388 case SCTP_STATE_SHUTDOWN_PENDING:
1389 case SCTP_STATE_SHUTDOWN_RECEIVED:
1390 case SCTP_STATE_SHUTDOWN_SENT:
1391 if ((asoc->rwnd > asoc->a_rwnd) &&
1392 ((asoc->rwnd - asoc->a_rwnd) >= max_t(__u32,
1393 (asoc->base.sk->sk_rcvbuf >> sctp_rwnd_upd_shift),
1394 asoc->pathmtu)))
1395 return 1;
1396 break;
1397 default:
1398 break;
1400 return 0;
1403 /* Increase asoc's rwnd by len and send any window update SACK if needed. */
1404 void sctp_assoc_rwnd_increase(struct sctp_association *asoc, unsigned len)
1406 struct sctp_chunk *sack;
1407 struct timer_list *timer;
1409 if (asoc->rwnd_over) {
1410 if (asoc->rwnd_over >= len) {
1411 asoc->rwnd_over -= len;
1412 } else {
1413 asoc->rwnd += (len - asoc->rwnd_over);
1414 asoc->rwnd_over = 0;
1416 } else {
1417 asoc->rwnd += len;
1420 /* If we had window pressure, start recovering it
1421 * once our rwnd had reached the accumulated pressure
1422 * threshold. The idea is to recover slowly, but up
1423 * to the initial advertised window.
1425 if (asoc->rwnd_press && asoc->rwnd >= asoc->rwnd_press) {
1426 int change = min(asoc->pathmtu, asoc->rwnd_press);
1427 asoc->rwnd += change;
1428 asoc->rwnd_press -= change;
1431 SCTP_DEBUG_PRINTK("%s: asoc %p rwnd increased by %d to (%u, %u) "
1432 "- %u\n", __func__, asoc, len, asoc->rwnd,
1433 asoc->rwnd_over, asoc->a_rwnd);
1435 /* Send a window update SACK if the rwnd has increased by at least the
1436 * minimum of the association's PMTU and half of the receive buffer.
1437 * The algorithm used is similar to the one described in
1438 * Section 4.2.3.3 of RFC 1122.
1440 if (sctp_peer_needs_update(asoc)) {
1441 asoc->a_rwnd = asoc->rwnd;
1442 SCTP_DEBUG_PRINTK("%s: Sending window update SACK- asoc: %p "
1443 "rwnd: %u a_rwnd: %u\n", __func__,
1444 asoc, asoc->rwnd, asoc->a_rwnd);
1445 sack = sctp_make_sack(asoc);
1446 if (!sack)
1447 return;
1449 asoc->peer.sack_needed = 0;
1451 sctp_outq_tail(&asoc->outqueue, sack);
1453 /* Stop the SACK timer. */
1454 timer = &asoc->timers[SCTP_EVENT_TIMEOUT_SACK];
1455 if (timer_pending(timer) && del_timer(timer))
1456 sctp_association_put(asoc);
1460 /* Decrease asoc's rwnd by len. */
1461 void sctp_assoc_rwnd_decrease(struct sctp_association *asoc, unsigned len)
1463 int rx_count;
1464 int over = 0;
1466 SCTP_ASSERT(asoc->rwnd, "rwnd zero", return);
1467 SCTP_ASSERT(!asoc->rwnd_over, "rwnd_over not zero", return);
1469 if (asoc->ep->rcvbuf_policy)
1470 rx_count = atomic_read(&asoc->rmem_alloc);
1471 else
1472 rx_count = atomic_read(&asoc->base.sk->sk_rmem_alloc);
1474 /* If we've reached or overflowed our receive buffer, announce
1475 * a 0 rwnd if rwnd would still be positive. Store the
1476 * the pottential pressure overflow so that the window can be restored
1477 * back to original value.
1479 if (rx_count >= asoc->base.sk->sk_rcvbuf)
1480 over = 1;
1482 if (asoc->rwnd >= len) {
1483 asoc->rwnd -= len;
1484 if (over) {
1485 asoc->rwnd_press += asoc->rwnd;
1486 asoc->rwnd = 0;
1488 } else {
1489 asoc->rwnd_over = len - asoc->rwnd;
1490 asoc->rwnd = 0;
1492 SCTP_DEBUG_PRINTK("%s: asoc %p rwnd decreased by %d to (%u, %u, %u)\n",
1493 __func__, asoc, len, asoc->rwnd,
1494 asoc->rwnd_over, asoc->rwnd_press);
1497 /* Build the bind address list for the association based on info from the
1498 * local endpoint and the remote peer.
1500 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
1501 sctp_scope_t scope, gfp_t gfp)
1503 int flags;
1505 /* Use scoping rules to determine the subset of addresses from
1506 * the endpoint.
1508 flags = (PF_INET6 == asoc->base.sk->sk_family) ? SCTP_ADDR6_ALLOWED : 0;
1509 if (asoc->peer.ipv4_address)
1510 flags |= SCTP_ADDR4_PEERSUPP;
1511 if (asoc->peer.ipv6_address)
1512 flags |= SCTP_ADDR6_PEERSUPP;
1514 return sctp_bind_addr_copy(&asoc->base.bind_addr,
1515 &asoc->ep->base.bind_addr,
1516 scope, gfp, flags);
1519 /* Build the association's bind address list from the cookie. */
1520 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *asoc,
1521 struct sctp_cookie *cookie,
1522 gfp_t gfp)
1524 int var_size2 = ntohs(cookie->peer_init->chunk_hdr.length);
1525 int var_size3 = cookie->raw_addr_list_len;
1526 __u8 *raw = (__u8 *)cookie->peer_init + var_size2;
1528 return sctp_raw_to_bind_addrs(&asoc->base.bind_addr, raw, var_size3,
1529 asoc->ep->base.bind_addr.port, gfp);
1532 /* Lookup laddr in the bind address list of an association. */
1533 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
1534 const union sctp_addr *laddr)
1536 int found = 0;
1538 if ((asoc->base.bind_addr.port == ntohs(laddr->v4.sin_port)) &&
1539 sctp_bind_addr_match(&asoc->base.bind_addr, laddr,
1540 sctp_sk(asoc->base.sk)))
1541 found = 1;
1543 return found;
1546 /* Set an association id for a given association */
1547 int sctp_assoc_set_id(struct sctp_association *asoc, gfp_t gfp)
1549 int assoc_id;
1550 int error = 0;
1552 /* If the id is already assigned, keep it. */
1553 if (asoc->assoc_id)
1554 return error;
1555 retry:
1556 if (unlikely(!idr_pre_get(&sctp_assocs_id, gfp)))
1557 return -ENOMEM;
1559 spin_lock_bh(&sctp_assocs_id_lock);
1560 error = idr_get_new_above(&sctp_assocs_id, (void *)asoc,
1561 idr_low, &assoc_id);
1562 if (!error) {
1563 idr_low = assoc_id + 1;
1564 if (idr_low == INT_MAX)
1565 idr_low = 1;
1567 spin_unlock_bh(&sctp_assocs_id_lock);
1568 if (error == -EAGAIN)
1569 goto retry;
1570 else if (error)
1571 return error;
1573 asoc->assoc_id = (sctp_assoc_t) assoc_id;
1574 return error;
1577 /* Free the ASCONF queue */
1578 static void sctp_assoc_free_asconf_queue(struct sctp_association *asoc)
1580 struct sctp_chunk *asconf;
1581 struct sctp_chunk *tmp;
1583 list_for_each_entry_safe(asconf, tmp, &asoc->addip_chunk_list, list) {
1584 list_del_init(&asconf->list);
1585 sctp_chunk_free(asconf);
1589 /* Free asconf_ack cache */
1590 static void sctp_assoc_free_asconf_acks(struct sctp_association *asoc)
1592 struct sctp_chunk *ack;
1593 struct sctp_chunk *tmp;
1595 list_for_each_entry_safe(ack, tmp, &asoc->asconf_ack_list,
1596 transmitted_list) {
1597 list_del_init(&ack->transmitted_list);
1598 sctp_chunk_free(ack);
1602 /* Clean up the ASCONF_ACK queue */
1603 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc)
1605 struct sctp_chunk *ack;
1606 struct sctp_chunk *tmp;
1608 /* We can remove all the entries from the queue up to
1609 * the "Peer-Sequence-Number".
1611 list_for_each_entry_safe(ack, tmp, &asoc->asconf_ack_list,
1612 transmitted_list) {
1613 if (ack->subh.addip_hdr->serial ==
1614 htonl(asoc->peer.addip_serial))
1615 break;
1617 list_del_init(&ack->transmitted_list);
1618 sctp_chunk_free(ack);
1622 /* Find the ASCONF_ACK whose serial number matches ASCONF */
1623 struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
1624 const struct sctp_association *asoc,
1625 __be32 serial)
1627 struct sctp_chunk *ack;
1629 /* Walk through the list of cached ASCONF-ACKs and find the
1630 * ack chunk whose serial number matches that of the request.
1632 list_for_each_entry(ack, &asoc->asconf_ack_list, transmitted_list) {
1633 if (ack->subh.addip_hdr->serial == serial) {
1634 sctp_chunk_hold(ack);
1635 return ack;
1639 return NULL;
1642 void sctp_asconf_queue_teardown(struct sctp_association *asoc)
1644 /* Free any cached ASCONF_ACK chunk. */
1645 sctp_assoc_free_asconf_acks(asoc);
1647 /* Free the ASCONF queue. */
1648 sctp_assoc_free_asconf_queue(asoc);
1650 /* Free any cached ASCONF chunk. */
1651 if (asoc->addip_last_asconf)
1652 sctp_chunk_free(asoc->addip_last_asconf);