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)
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, see
26 * <http://www.gnu.org/licenses/>.
28 * Please send any bug reports or fixes you make to the
30 * lksctp developers <linux-sctp@vger.kernel.org>
32 * Written or modified by:
33 * La Monte H.P. Yarroll <piggy@acm.org>
34 * Karl Knutson <karl@athena.chicago.il.us>
35 * Jon Grimm <jgrimm@us.ibm.com>
36 * Xingang Guo <xingang.guo@intel.com>
37 * Hui Huang <hui.huang@nokia.com>
38 * Sridhar Samudrala <sri@us.ibm.com>
39 * Daisy Chang <daisyc@us.ibm.com>
40 * Ryan Layer <rmlayer@us.ibm.com>
41 * Kevin Gao <kevin.gao@intel.com>
44 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
46 #include <linux/types.h>
47 #include <linux/fcntl.h>
48 #include <linux/poll.h>
49 #include <linux/init.h>
51 #include <linux/slab.h>
54 #include <net/sctp/sctp.h>
55 #include <net/sctp/sm.h>
57 /* Forward declarations for internal functions. */
58 static void sctp_select_active_and_retran_path(struct sctp_association *asoc);
59 static void sctp_assoc_bh_rcv(struct work_struct *work);
60 static void sctp_assoc_free_asconf_acks(struct sctp_association *asoc);
61 static void sctp_assoc_free_asconf_queue(struct sctp_association *asoc);
63 /* 1st Level Abstractions. */
65 /* Initialize a new association from provided memory. */
66 static struct sctp_association *sctp_association_init(struct sctp_association *asoc,
67 const struct sctp_endpoint *ep,
68 const struct sock *sk,
72 struct net *net = sock_net(sk);
77 /* Retrieve the SCTP per socket area. */
78 sp = sctp_sk((struct sock *)sk);
80 /* Discarding const is appropriate here. */
81 asoc->ep = (struct sctp_endpoint *)ep;
82 asoc->base.sk = (struct sock *)sk;
84 sctp_endpoint_hold(asoc->ep);
85 sock_hold(asoc->base.sk);
87 /* Initialize the common base substructure. */
88 asoc->base.type = SCTP_EP_TYPE_ASSOCIATION;
90 /* Initialize the object handling fields. */
91 atomic_set(&asoc->base.refcnt, 1);
93 /* Initialize the bind addr area. */
94 sctp_bind_addr_init(&asoc->base.bind_addr, ep->base.bind_addr.port);
96 asoc->state = SCTP_STATE_CLOSED;
97 asoc->cookie_life = ms_to_ktime(sp->assocparams.sasoc_cookie_life);
98 asoc->user_frag = sp->user_frag;
100 /* Set the association max_retrans and RTO values from the
103 asoc->max_retrans = sp->assocparams.sasoc_asocmaxrxt;
104 asoc->pf_retrans = net->sctp.pf_retrans;
106 asoc->rto_initial = msecs_to_jiffies(sp->rtoinfo.srto_initial);
107 asoc->rto_max = msecs_to_jiffies(sp->rtoinfo.srto_max);
108 asoc->rto_min = msecs_to_jiffies(sp->rtoinfo.srto_min);
110 /* Initialize the association's heartbeat interval based on the
111 * sock configured value.
113 asoc->hbinterval = msecs_to_jiffies(sp->hbinterval);
115 /* Initialize path max retrans value. */
116 asoc->pathmaxrxt = sp->pathmaxrxt;
118 /* Initialize default path MTU. */
119 asoc->pathmtu = sp->pathmtu;
121 /* Set association default SACK delay */
122 asoc->sackdelay = msecs_to_jiffies(sp->sackdelay);
123 asoc->sackfreq = sp->sackfreq;
125 /* Set the association default flags controlling
126 * Heartbeat, SACK delay, and Path MTU Discovery.
128 asoc->param_flags = sp->param_flags;
130 /* Initialize the maximum number of new data packets that can be sent
133 asoc->max_burst = sp->max_burst;
135 /* initialize association timers */
136 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] = asoc->rto_initial;
137 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] = asoc->rto_initial;
138 asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = asoc->rto_initial;
140 /* sctpimpguide Section 2.12.2
141 * If the 'T5-shutdown-guard' timer is used, it SHOULD be set to the
142 * recommended value of 5 times 'RTO.Max'.
144 asoc->timeouts[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD]
147 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] = asoc->sackdelay;
148 asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE] = sp->autoclose * HZ;
150 /* Initializes the timers */
151 for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i)
152 setup_timer(&asoc->timers[i], sctp_timer_events[i],
153 (unsigned long)asoc);
155 /* Pull default initialization values from the sock options.
156 * Note: This assumes that the values have already been
157 * validated in the sock.
159 asoc->c.sinit_max_instreams = sp->initmsg.sinit_max_instreams;
160 asoc->c.sinit_num_ostreams = sp->initmsg.sinit_num_ostreams;
161 asoc->max_init_attempts = sp->initmsg.sinit_max_attempts;
163 asoc->max_init_timeo =
164 msecs_to_jiffies(sp->initmsg.sinit_max_init_timeo);
166 /* Set the local window size for receive.
167 * This is also the rcvbuf space per association.
168 * RFC 6 - A SCTP receiver MUST be able to receive a minimum of
169 * 1500 bytes in one SCTP packet.
171 if ((sk->sk_rcvbuf/2) < SCTP_DEFAULT_MINWINDOW)
172 asoc->rwnd = SCTP_DEFAULT_MINWINDOW;
174 asoc->rwnd = sk->sk_rcvbuf/2;
176 asoc->a_rwnd = asoc->rwnd;
178 /* Use my own max window until I learn something better. */
179 asoc->peer.rwnd = SCTP_DEFAULT_MAXWINDOW;
181 /* Initialize the receive memory counter */
182 atomic_set(&asoc->rmem_alloc, 0);
184 init_waitqueue_head(&asoc->wait);
186 asoc->c.my_vtag = sctp_generate_tag(ep);
187 asoc->c.my_port = ep->base.bind_addr.port;
189 asoc->c.initial_tsn = sctp_generate_tsn(ep);
191 asoc->next_tsn = asoc->c.initial_tsn;
193 asoc->ctsn_ack_point = asoc->next_tsn - 1;
194 asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
195 asoc->highest_sacked = asoc->ctsn_ack_point;
196 asoc->last_cwr_tsn = asoc->ctsn_ack_point;
198 /* ADDIP Section 4.1 Asconf Chunk Procedures
200 * When an endpoint has an ASCONF signaled change to be sent to the
201 * remote endpoint it should do the following:
203 * A2) a serial number should be assigned to the chunk. The serial
204 * number SHOULD be a monotonically increasing number. The serial
205 * numbers SHOULD be initialized at the start of the
206 * association to the same value as the initial TSN.
208 asoc->addip_serial = asoc->c.initial_tsn;
209 asoc->strreset_outseq = asoc->c.initial_tsn;
211 INIT_LIST_HEAD(&asoc->addip_chunk_list);
212 INIT_LIST_HEAD(&asoc->asconf_ack_list);
214 /* Make an empty list of remote transport addresses. */
215 INIT_LIST_HEAD(&asoc->peer.transport_addr_list);
217 /* RFC 2960 5.1 Normal Establishment of an Association
219 * After the reception of the first data chunk in an
220 * association the endpoint must immediately respond with a
221 * sack to acknowledge the data chunk. Subsequent
222 * acknowledgements should be done as described in Section
225 * [We implement this by telling a new association that it
226 * already received one packet.]
228 asoc->peer.sack_needed = 1;
229 asoc->peer.sack_generation = 1;
231 /* Assume that the peer will tell us if he recognizes ASCONF
232 * as part of INIT exchange.
233 * The sctp_addip_noauth option is there for backward compatibility
234 * and will revert old behavior.
236 if (net->sctp.addip_noauth)
237 asoc->peer.asconf_capable = 1;
239 /* Create an input queue. */
240 sctp_inq_init(&asoc->base.inqueue);
241 sctp_inq_set_th_handler(&asoc->base.inqueue, sctp_assoc_bh_rcv);
243 /* Create an output queue. */
244 sctp_outq_init(asoc, &asoc->outqueue);
246 if (!sctp_ulpq_init(&asoc->ulpq, asoc))
249 if (sctp_stream_init(&asoc->stream, asoc->c.sinit_num_ostreams,
253 /* Assume that peer would support both address types unless we are
256 asoc->peer.ipv4_address = 1;
257 if (asoc->base.sk->sk_family == PF_INET6)
258 asoc->peer.ipv6_address = 1;
259 INIT_LIST_HEAD(&asoc->asocs);
261 asoc->default_stream = sp->default_stream;
262 asoc->default_ppid = sp->default_ppid;
263 asoc->default_flags = sp->default_flags;
264 asoc->default_context = sp->default_context;
265 asoc->default_timetolive = sp->default_timetolive;
266 asoc->default_rcv_context = sp->default_rcv_context;
268 /* AUTH related initializations */
269 INIT_LIST_HEAD(&asoc->endpoint_shared_keys);
270 if (sctp_auth_asoc_copy_shkeys(ep, asoc, gfp))
273 asoc->active_key_id = ep->active_key_id;
274 asoc->prsctp_enable = ep->prsctp_enable;
275 asoc->reconf_enable = ep->reconf_enable;
276 asoc->strreset_enable = ep->strreset_enable;
278 /* Save the hmacs and chunks list into this association */
279 if (ep->auth_hmacs_list)
280 memcpy(asoc->c.auth_hmacs, ep->auth_hmacs_list,
281 ntohs(ep->auth_hmacs_list->param_hdr.length));
282 if (ep->auth_chunk_list)
283 memcpy(asoc->c.auth_chunks, ep->auth_chunk_list,
284 ntohs(ep->auth_chunk_list->param_hdr.length));
286 /* Get the AUTH random number for this association */
287 p = (sctp_paramhdr_t *)asoc->c.auth_random;
288 p->type = SCTP_PARAM_RANDOM;
289 p->length = htons(sizeof(sctp_paramhdr_t) + SCTP_AUTH_RANDOM_LENGTH);
290 get_random_bytes(p+1, SCTP_AUTH_RANDOM_LENGTH);
295 sctp_stream_free(&asoc->stream);
297 sock_put(asoc->base.sk);
298 sctp_endpoint_put(asoc->ep);
302 /* Allocate and initialize a new association */
303 struct sctp_association *sctp_association_new(const struct sctp_endpoint *ep,
304 const struct sock *sk,
308 struct sctp_association *asoc;
310 asoc = kzalloc(sizeof(*asoc), gfp);
314 if (!sctp_association_init(asoc, ep, sk, scope, gfp))
317 SCTP_DBG_OBJCNT_INC(assoc);
319 pr_debug("Created asoc %p\n", asoc);
329 /* Free this association if possible. There may still be users, so
330 * the actual deallocation may be delayed.
332 void sctp_association_free(struct sctp_association *asoc)
334 struct sock *sk = asoc->base.sk;
335 struct sctp_transport *transport;
336 struct list_head *pos, *temp;
339 /* Only real associations count against the endpoint, so
340 * don't bother for if this is a temporary association.
342 if (!list_empty(&asoc->asocs)) {
343 list_del(&asoc->asocs);
345 /* Decrement the backlog value for a TCP-style listening
348 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
349 sk->sk_ack_backlog--;
352 /* Mark as dead, so other users can know this structure is
355 asoc->base.dead = true;
357 /* Dispose of any data lying around in the outqueue. */
358 sctp_outq_free(&asoc->outqueue);
360 /* Dispose of any pending messages for the upper layer. */
361 sctp_ulpq_free(&asoc->ulpq);
363 /* Dispose of any pending chunks on the inqueue. */
364 sctp_inq_free(&asoc->base.inqueue);
366 sctp_tsnmap_free(&asoc->peer.tsn_map);
368 /* Free stream information. */
369 sctp_stream_free(&asoc->stream);
371 if (asoc->strreset_chunk)
372 sctp_chunk_free(asoc->strreset_chunk);
374 /* Clean up the bound address list. */
375 sctp_bind_addr_free(&asoc->base.bind_addr);
377 /* Do we need to go through all of our timers and
378 * delete them? To be safe we will try to delete all, but we
379 * should be able to go through and make a guess based
382 for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i) {
383 if (del_timer(&asoc->timers[i]))
384 sctp_association_put(asoc);
387 /* Free peer's cached cookie. */
388 kfree(asoc->peer.cookie);
389 kfree(asoc->peer.peer_random);
390 kfree(asoc->peer.peer_chunks);
391 kfree(asoc->peer.peer_hmacs);
393 /* Release the transport structures. */
394 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
395 transport = list_entry(pos, struct sctp_transport, transports);
397 sctp_unhash_transport(transport);
398 sctp_transport_free(transport);
401 asoc->peer.transport_count = 0;
403 sctp_asconf_queue_teardown(asoc);
405 /* Free pending address space being deleted */
406 kfree(asoc->asconf_addr_del_pending);
408 /* AUTH - Free the endpoint shared keys */
409 sctp_auth_destroy_keys(&asoc->endpoint_shared_keys);
411 /* AUTH - Free the association shared key */
412 sctp_auth_key_put(asoc->asoc_shared_key);
414 sctp_association_put(asoc);
417 /* Cleanup and free up an association. */
418 static void sctp_association_destroy(struct sctp_association *asoc)
420 if (unlikely(!asoc->base.dead)) {
421 WARN(1, "Attempt to destroy undead association %p!\n", asoc);
425 sctp_endpoint_put(asoc->ep);
426 sock_put(asoc->base.sk);
428 if (asoc->assoc_id != 0) {
429 spin_lock_bh(&sctp_assocs_id_lock);
430 idr_remove(&sctp_assocs_id, asoc->assoc_id);
431 spin_unlock_bh(&sctp_assocs_id_lock);
434 WARN_ON(atomic_read(&asoc->rmem_alloc));
437 SCTP_DBG_OBJCNT_DEC(assoc);
440 /* Change the primary destination address for the peer. */
441 void sctp_assoc_set_primary(struct sctp_association *asoc,
442 struct sctp_transport *transport)
446 /* it's a changeover only if we already have a primary path
447 * that we are changing
449 if (asoc->peer.primary_path != NULL &&
450 asoc->peer.primary_path != transport)
453 asoc->peer.primary_path = transport;
455 /* Set a default msg_name for events. */
456 memcpy(&asoc->peer.primary_addr, &transport->ipaddr,
457 sizeof(union sctp_addr));
459 /* If the primary path is changing, assume that the
460 * user wants to use this new path.
462 if ((transport->state == SCTP_ACTIVE) ||
463 (transport->state == SCTP_UNKNOWN))
464 asoc->peer.active_path = transport;
467 * SFR-CACC algorithm:
468 * Upon the receipt of a request to change the primary
469 * destination address, on the data structure for the new
470 * primary destination, the sender MUST do the following:
472 * 1) If CHANGEOVER_ACTIVE is set, then there was a switch
473 * to this destination address earlier. The sender MUST set
474 * CYCLING_CHANGEOVER to indicate that this switch is a
475 * double switch to the same destination address.
477 * Really, only bother is we have data queued or outstanding on
480 if (!asoc->outqueue.outstanding_bytes && !asoc->outqueue.out_qlen)
483 if (transport->cacc.changeover_active)
484 transport->cacc.cycling_changeover = changeover;
486 /* 2) The sender MUST set CHANGEOVER_ACTIVE to indicate that
487 * a changeover has occurred.
489 transport->cacc.changeover_active = changeover;
491 /* 3) The sender MUST store the next TSN to be sent in
492 * next_tsn_at_change.
494 transport->cacc.next_tsn_at_change = asoc->next_tsn;
497 /* Remove a transport from an association. */
498 void sctp_assoc_rm_peer(struct sctp_association *asoc,
499 struct sctp_transport *peer)
501 struct list_head *pos;
502 struct sctp_transport *transport;
504 pr_debug("%s: association:%p addr:%pISpc\n",
505 __func__, asoc, &peer->ipaddr.sa);
507 /* If we are to remove the current retran_path, update it
508 * to the next peer before removing this peer from the list.
510 if (asoc->peer.retran_path == peer)
511 sctp_assoc_update_retran_path(asoc);
513 /* Remove this peer from the list. */
514 list_del_rcu(&peer->transports);
515 /* Remove this peer from the transport hashtable */
516 sctp_unhash_transport(peer);
518 /* Get the first transport of asoc. */
519 pos = asoc->peer.transport_addr_list.next;
520 transport = list_entry(pos, struct sctp_transport, transports);
522 /* Update any entries that match the peer to be deleted. */
523 if (asoc->peer.primary_path == peer)
524 sctp_assoc_set_primary(asoc, transport);
525 if (asoc->peer.active_path == peer)
526 asoc->peer.active_path = transport;
527 if (asoc->peer.retran_path == peer)
528 asoc->peer.retran_path = transport;
529 if (asoc->peer.last_data_from == peer)
530 asoc->peer.last_data_from = transport;
532 if (asoc->strreset_chunk &&
533 asoc->strreset_chunk->transport == peer) {
534 asoc->strreset_chunk->transport = transport;
535 sctp_transport_reset_reconf_timer(transport);
538 /* If we remove the transport an INIT was last sent to, set it to
539 * NULL. Combined with the update of the retran path above, this
540 * will cause the next INIT to be sent to the next available
541 * transport, maintaining the cycle.
543 if (asoc->init_last_sent_to == peer)
544 asoc->init_last_sent_to = NULL;
546 /* If we remove the transport an SHUTDOWN was last sent to, set it
547 * to NULL. Combined with the update of the retran path above, this
548 * will cause the next SHUTDOWN to be sent to the next available
549 * transport, maintaining the cycle.
551 if (asoc->shutdown_last_sent_to == peer)
552 asoc->shutdown_last_sent_to = NULL;
554 /* If we remove the transport an ASCONF was last sent to, set it to
557 if (asoc->addip_last_asconf &&
558 asoc->addip_last_asconf->transport == peer)
559 asoc->addip_last_asconf->transport = NULL;
561 /* If we have something on the transmitted list, we have to
562 * save it off. The best place is the active path.
564 if (!list_empty(&peer->transmitted)) {
565 struct sctp_transport *active = asoc->peer.active_path;
566 struct sctp_chunk *ch;
568 /* Reset the transport of each chunk on this list */
569 list_for_each_entry(ch, &peer->transmitted,
571 ch->transport = NULL;
572 ch->rtt_in_progress = 0;
575 list_splice_tail_init(&peer->transmitted,
576 &active->transmitted);
578 /* Start a T3 timer here in case it wasn't running so
579 * that these migrated packets have a chance to get
582 if (!timer_pending(&active->T3_rtx_timer))
583 if (!mod_timer(&active->T3_rtx_timer,
584 jiffies + active->rto))
585 sctp_transport_hold(active);
588 asoc->peer.transport_count--;
590 sctp_transport_free(peer);
593 /* Add a transport address to an association. */
594 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc,
595 const union sctp_addr *addr,
597 const int peer_state)
599 struct net *net = sock_net(asoc->base.sk);
600 struct sctp_transport *peer;
601 struct sctp_sock *sp;
604 sp = sctp_sk(asoc->base.sk);
606 /* AF_INET and AF_INET6 share common port field. */
607 port = ntohs(addr->v4.sin_port);
609 pr_debug("%s: association:%p addr:%pISpc state:%d\n", __func__,
610 asoc, &addr->sa, peer_state);
612 /* Set the port if it has not been set yet. */
613 if (0 == asoc->peer.port)
614 asoc->peer.port = port;
616 /* Check to see if this is a duplicate. */
617 peer = sctp_assoc_lookup_paddr(asoc, addr);
619 /* An UNKNOWN state is only set on transports added by
620 * user in sctp_connectx() call. Such transports should be
621 * considered CONFIRMED per RFC 4960, Section 5.4.
623 if (peer->state == SCTP_UNKNOWN) {
624 peer->state = SCTP_ACTIVE;
629 peer = sctp_transport_new(net, addr, gfp);
633 sctp_transport_set_owner(peer, asoc);
635 /* Initialize the peer's heartbeat interval based on the
636 * association configured value.
638 peer->hbinterval = asoc->hbinterval;
640 /* Set the path max_retrans. */
641 peer->pathmaxrxt = asoc->pathmaxrxt;
643 /* And the partial failure retrans threshold */
644 peer->pf_retrans = asoc->pf_retrans;
646 /* Initialize the peer's SACK delay timeout based on the
647 * association configured value.
649 peer->sackdelay = asoc->sackdelay;
650 peer->sackfreq = asoc->sackfreq;
652 /* Enable/disable heartbeat, SACK delay, and path MTU discovery
653 * based on association setting.
655 peer->param_flags = asoc->param_flags;
657 sctp_transport_route(peer, NULL, sp);
659 /* Initialize the pmtu of the transport. */
660 if (peer->param_flags & SPP_PMTUD_DISABLE) {
662 peer->pathmtu = asoc->pathmtu;
664 peer->pathmtu = SCTP_DEFAULT_MAXSEGMENT;
667 /* If this is the first transport addr on this association,
668 * initialize the association PMTU to the peer's PMTU.
669 * If not and the current association PMTU is higher than the new
670 * peer's PMTU, reset the association PMTU to the new peer's PMTU.
673 asoc->pathmtu = min_t(int, peer->pathmtu, asoc->pathmtu);
675 asoc->pathmtu = peer->pathmtu;
677 pr_debug("%s: association:%p PMTU set to %d\n", __func__, asoc,
680 peer->pmtu_pending = 0;
682 asoc->frag_point = sctp_frag_point(asoc, asoc->pathmtu);
684 /* The asoc->peer.port might not be meaningful yet, but
685 * initialize the packet structure anyway.
687 sctp_packet_init(&peer->packet, peer, asoc->base.bind_addr.port,
692 * o The initial cwnd before DATA transmission or after a sufficiently
693 * long idle period MUST be set to
694 * min(4*MTU, max(2*MTU, 4380 bytes))
696 * o The initial value of ssthresh MAY be arbitrarily high
697 * (for example, implementations MAY use the size of the
698 * receiver advertised window).
700 peer->cwnd = min(4*asoc->pathmtu, max_t(__u32, 2*asoc->pathmtu, 4380));
702 /* At this point, we may not have the receiver's advertised window,
703 * so initialize ssthresh to the default value and it will be set
704 * later when we process the INIT.
706 peer->ssthresh = SCTP_DEFAULT_MAXWINDOW;
708 peer->partial_bytes_acked = 0;
709 peer->flight_size = 0;
710 peer->burst_limited = 0;
712 /* Set the transport's RTO.initial value */
713 peer->rto = asoc->rto_initial;
714 sctp_max_rto(asoc, peer);
716 /* Set the peer's active state. */
717 peer->state = peer_state;
719 /* Add this peer into the transport hashtable */
720 if (sctp_hash_transport(peer)) {
721 sctp_transport_free(peer);
725 /* Attach the remote transport to our asoc. */
726 list_add_tail_rcu(&peer->transports, &asoc->peer.transport_addr_list);
727 asoc->peer.transport_count++;
729 /* If we do not yet have a primary path, set one. */
730 if (!asoc->peer.primary_path) {
731 sctp_assoc_set_primary(asoc, peer);
732 asoc->peer.retran_path = peer;
735 if (asoc->peer.active_path == asoc->peer.retran_path &&
736 peer->state != SCTP_UNCONFIRMED) {
737 asoc->peer.retran_path = peer;
743 /* Delete a transport address from an association. */
744 void sctp_assoc_del_peer(struct sctp_association *asoc,
745 const union sctp_addr *addr)
747 struct list_head *pos;
748 struct list_head *temp;
749 struct sctp_transport *transport;
751 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
752 transport = list_entry(pos, struct sctp_transport, transports);
753 if (sctp_cmp_addr_exact(addr, &transport->ipaddr)) {
754 /* Do book keeping for removing the peer and free it. */
755 sctp_assoc_rm_peer(asoc, transport);
761 /* Lookup a transport by address. */
762 struct sctp_transport *sctp_assoc_lookup_paddr(
763 const struct sctp_association *asoc,
764 const union sctp_addr *address)
766 struct sctp_transport *t;
768 /* Cycle through all transports searching for a peer address. */
770 list_for_each_entry(t, &asoc->peer.transport_addr_list,
772 if (sctp_cmp_addr_exact(address, &t->ipaddr))
779 /* Remove all transports except a give one */
780 void sctp_assoc_del_nonprimary_peers(struct sctp_association *asoc,
781 struct sctp_transport *primary)
783 struct sctp_transport *temp;
784 struct sctp_transport *t;
786 list_for_each_entry_safe(t, temp, &asoc->peer.transport_addr_list,
788 /* if the current transport is not the primary one, delete it */
790 sctp_assoc_rm_peer(asoc, t);
794 /* Engage in transport control operations.
795 * Mark the transport up or down and send a notification to the user.
796 * Select and update the new active and retran paths.
798 void sctp_assoc_control_transport(struct sctp_association *asoc,
799 struct sctp_transport *transport,
800 sctp_transport_cmd_t command,
801 sctp_sn_error_t error)
803 struct sctp_ulpevent *event;
804 struct sockaddr_storage addr;
806 bool ulp_notify = true;
808 /* Record the transition on the transport. */
810 case SCTP_TRANSPORT_UP:
811 /* If we are moving from UNCONFIRMED state due
812 * to heartbeat success, report the SCTP_ADDR_CONFIRMED
813 * state to the user, otherwise report SCTP_ADDR_AVAILABLE.
815 if (SCTP_UNCONFIRMED == transport->state &&
816 SCTP_HEARTBEAT_SUCCESS == error)
817 spc_state = SCTP_ADDR_CONFIRMED;
819 spc_state = SCTP_ADDR_AVAILABLE;
820 /* Don't inform ULP about transition from PF to
821 * active state and set cwnd to 1 MTU, see SCTP
822 * Quick failover draft section 5.1, point 5
824 if (transport->state == SCTP_PF) {
826 transport->cwnd = asoc->pathmtu;
828 transport->state = SCTP_ACTIVE;
831 case SCTP_TRANSPORT_DOWN:
832 /* If the transport was never confirmed, do not transition it
833 * to inactive state. Also, release the cached route since
834 * there may be a better route next time.
836 if (transport->state != SCTP_UNCONFIRMED)
837 transport->state = SCTP_INACTIVE;
839 sctp_transport_dst_release(transport);
843 spc_state = SCTP_ADDR_UNREACHABLE;
846 case SCTP_TRANSPORT_PF:
847 transport->state = SCTP_PF;
855 /* Generate and send a SCTP_PEER_ADDR_CHANGE notification
859 memset(&addr, 0, sizeof(struct sockaddr_storage));
860 memcpy(&addr, &transport->ipaddr,
861 transport->af_specific->sockaddr_len);
863 event = sctp_ulpevent_make_peer_addr_change(asoc, &addr,
864 0, spc_state, error, GFP_ATOMIC);
866 sctp_ulpq_tail_event(&asoc->ulpq, event);
869 /* Select new active and retran paths. */
870 sctp_select_active_and_retran_path(asoc);
873 /* Hold a reference to an association. */
874 void sctp_association_hold(struct sctp_association *asoc)
876 atomic_inc(&asoc->base.refcnt);
879 /* Release a reference to an association and cleanup
880 * if there are no more references.
882 void sctp_association_put(struct sctp_association *asoc)
884 if (atomic_dec_and_test(&asoc->base.refcnt))
885 sctp_association_destroy(asoc);
888 /* Allocate the next TSN, Transmission Sequence Number, for the given
891 __u32 sctp_association_get_next_tsn(struct sctp_association *asoc)
893 /* From Section 1.6 Serial Number Arithmetic:
894 * Transmission Sequence Numbers wrap around when they reach
895 * 2**32 - 1. That is, the next TSN a DATA chunk MUST use
896 * after transmitting TSN = 2*32 - 1 is TSN = 0.
898 __u32 retval = asoc->next_tsn;
905 /* Compare two addresses to see if they match. Wildcard addresses
906 * only match themselves.
908 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
909 const union sctp_addr *ss2)
913 af = sctp_get_af_specific(ss1->sa.sa_family);
917 return af->cmp_addr(ss1, ss2);
920 /* Return an ecne chunk to get prepended to a packet.
921 * Note: We are sly and return a shared, prealloced chunk. FIXME:
922 * No we don't, but we could/should.
924 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc)
926 if (!asoc->need_ecne)
929 /* Send ECNE if needed.
930 * Not being able to allocate a chunk here is not deadly.
932 return sctp_make_ecne(asoc, asoc->last_ecne_tsn);
936 * Find which transport this TSN was sent on.
938 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *asoc,
941 struct sctp_transport *active;
942 struct sctp_transport *match;
943 struct sctp_transport *transport;
944 struct sctp_chunk *chunk;
945 __be32 key = htonl(tsn);
950 * FIXME: In general, find a more efficient data structure for
955 * The general strategy is to search each transport's transmitted
956 * list. Return which transport this TSN lives on.
958 * Let's be hopeful and check the active_path first.
959 * Another optimization would be to know if there is only one
960 * outbound path and not have to look for the TSN at all.
964 active = asoc->peer.active_path;
966 list_for_each_entry(chunk, &active->transmitted,
969 if (key == chunk->subh.data_hdr->tsn) {
975 /* If not found, go search all the other transports. */
976 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
979 if (transport == active)
981 list_for_each_entry(chunk, &transport->transmitted,
983 if (key == chunk->subh.data_hdr->tsn) {
993 /* Is this the association we are looking for? */
994 struct sctp_transport *sctp_assoc_is_match(struct sctp_association *asoc,
996 const union sctp_addr *laddr,
997 const union sctp_addr *paddr)
999 struct sctp_transport *transport;
1001 if ((htons(asoc->base.bind_addr.port) == laddr->v4.sin_port) &&
1002 (htons(asoc->peer.port) == paddr->v4.sin_port) &&
1003 net_eq(sock_net(asoc->base.sk), net)) {
1004 transport = sctp_assoc_lookup_paddr(asoc, paddr);
1008 if (sctp_bind_addr_match(&asoc->base.bind_addr, laddr,
1009 sctp_sk(asoc->base.sk)))
1018 /* Do delayed input processing. This is scheduled by sctp_rcv(). */
1019 static void sctp_assoc_bh_rcv(struct work_struct *work)
1021 struct sctp_association *asoc =
1022 container_of(work, struct sctp_association,
1023 base.inqueue.immediate);
1024 struct net *net = sock_net(asoc->base.sk);
1025 struct sctp_endpoint *ep;
1026 struct sctp_chunk *chunk;
1027 struct sctp_inq *inqueue;
1029 sctp_subtype_t subtype;
1032 /* The association should be held so we should be safe. */
1035 inqueue = &asoc->base.inqueue;
1036 sctp_association_hold(asoc);
1037 while (NULL != (chunk = sctp_inq_pop(inqueue))) {
1038 state = asoc->state;
1039 subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type);
1041 /* SCTP-AUTH, Section 6.3:
1042 * The receiver has a list of chunk types which it expects
1043 * to be received only after an AUTH-chunk. This list has
1044 * been sent to the peer during the association setup. It
1045 * MUST silently discard these chunks if they are not placed
1046 * after an AUTH chunk in the packet.
1048 if (sctp_auth_recv_cid(subtype.chunk, asoc) && !chunk->auth)
1051 /* Remember where the last DATA chunk came from so we
1052 * know where to send the SACK.
1054 if (sctp_chunk_is_data(chunk))
1055 asoc->peer.last_data_from = chunk->transport;
1057 SCTP_INC_STATS(net, SCTP_MIB_INCTRLCHUNKS);
1058 asoc->stats.ictrlchunks++;
1059 if (chunk->chunk_hdr->type == SCTP_CID_SACK)
1060 asoc->stats.isacks++;
1063 if (chunk->transport)
1064 chunk->transport->last_time_heard = ktime_get();
1066 /* Run through the state machine. */
1067 error = sctp_do_sm(net, SCTP_EVENT_T_CHUNK, subtype,
1068 state, ep, asoc, chunk, GFP_ATOMIC);
1070 /* Check to see if the association is freed in response to
1071 * the incoming chunk. If so, get out of the while loop.
1073 if (asoc->base.dead)
1076 /* If there is an error on chunk, discard this packet. */
1078 chunk->pdiscard = 1;
1080 sctp_association_put(asoc);
1083 /* This routine moves an association from its old sk to a new sk. */
1084 void sctp_assoc_migrate(struct sctp_association *assoc, struct sock *newsk)
1086 struct sctp_sock *newsp = sctp_sk(newsk);
1087 struct sock *oldsk = assoc->base.sk;
1089 /* Delete the association from the old endpoint's list of
1092 list_del_init(&assoc->asocs);
1094 /* Decrement the backlog value for a TCP-style socket. */
1095 if (sctp_style(oldsk, TCP))
1096 oldsk->sk_ack_backlog--;
1098 /* Release references to the old endpoint and the sock. */
1099 sctp_endpoint_put(assoc->ep);
1100 sock_put(assoc->base.sk);
1102 /* Get a reference to the new endpoint. */
1103 assoc->ep = newsp->ep;
1104 sctp_endpoint_hold(assoc->ep);
1106 /* Get a reference to the new sock. */
1107 assoc->base.sk = newsk;
1108 sock_hold(assoc->base.sk);
1110 /* Add the association to the new endpoint's list of associations. */
1111 sctp_endpoint_add_asoc(newsp->ep, assoc);
1114 /* Update an association (possibly from unexpected COOKIE-ECHO processing). */
1115 void sctp_assoc_update(struct sctp_association *asoc,
1116 struct sctp_association *new)
1118 struct sctp_transport *trans;
1119 struct list_head *pos, *temp;
1121 /* Copy in new parameters of peer. */
1123 asoc->peer.rwnd = new->peer.rwnd;
1124 asoc->peer.sack_needed = new->peer.sack_needed;
1125 asoc->peer.auth_capable = new->peer.auth_capable;
1126 asoc->peer.i = new->peer.i;
1127 sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
1128 asoc->peer.i.initial_tsn, GFP_ATOMIC);
1130 /* Remove any peer addresses not present in the new association. */
1131 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
1132 trans = list_entry(pos, struct sctp_transport, transports);
1133 if (!sctp_assoc_lookup_paddr(new, &trans->ipaddr)) {
1134 sctp_assoc_rm_peer(asoc, trans);
1138 if (asoc->state >= SCTP_STATE_ESTABLISHED)
1139 sctp_transport_reset(trans);
1142 /* If the case is A (association restart), use
1143 * initial_tsn as next_tsn. If the case is B, use
1144 * current next_tsn in case data sent to peer
1145 * has been discarded and needs retransmission.
1147 if (asoc->state >= SCTP_STATE_ESTABLISHED) {
1148 asoc->next_tsn = new->next_tsn;
1149 asoc->ctsn_ack_point = new->ctsn_ack_point;
1150 asoc->adv_peer_ack_point = new->adv_peer_ack_point;
1152 /* Reinitialize SSN for both local streams
1153 * and peer's streams.
1155 sctp_stream_clear(&asoc->stream);
1157 /* Flush the ULP reassembly and ordered queue.
1158 * Any data there will now be stale and will
1161 sctp_ulpq_flush(&asoc->ulpq);
1163 /* reset the overall association error count so
1164 * that the restarted association doesn't get torn
1165 * down on the next retransmission timer.
1167 asoc->overall_error_count = 0;
1170 /* Add any peer addresses from the new association. */
1171 list_for_each_entry(trans, &new->peer.transport_addr_list,
1173 if (!sctp_assoc_lookup_paddr(asoc, &trans->ipaddr))
1174 sctp_assoc_add_peer(asoc, &trans->ipaddr,
1175 GFP_ATOMIC, trans->state);
1178 asoc->ctsn_ack_point = asoc->next_tsn - 1;
1179 asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
1181 if (sctp_state(asoc, COOKIE_WAIT))
1182 sctp_stream_update(&asoc->stream, &new->stream);
1184 if (!asoc->assoc_id) {
1185 /* get a new association id since we don't have one
1188 sctp_assoc_set_id(asoc, GFP_ATOMIC);
1192 /* SCTP-AUTH: Save the peer parameters from the new associations
1193 * and also move the association shared keys over
1195 kfree(asoc->peer.peer_random);
1196 asoc->peer.peer_random = new->peer.peer_random;
1197 new->peer.peer_random = NULL;
1199 kfree(asoc->peer.peer_chunks);
1200 asoc->peer.peer_chunks = new->peer.peer_chunks;
1201 new->peer.peer_chunks = NULL;
1203 kfree(asoc->peer.peer_hmacs);
1204 asoc->peer.peer_hmacs = new->peer.peer_hmacs;
1205 new->peer.peer_hmacs = NULL;
1207 sctp_auth_asoc_init_active_key(asoc, GFP_ATOMIC);
1210 /* Update the retran path for sending a retransmitted packet.
1211 * See also RFC4960, 6.4. Multi-Homed SCTP Endpoints:
1213 * When there is outbound data to send and the primary path
1214 * becomes inactive (e.g., due to failures), or where the
1215 * SCTP user explicitly requests to send data to an
1216 * inactive destination transport address, before reporting
1217 * an error to its ULP, the SCTP endpoint should try to send
1218 * the data to an alternate active destination transport
1219 * address if one exists.
1221 * When retransmitting data that timed out, if the endpoint
1222 * is multihomed, it should consider each source-destination
1223 * address pair in its retransmission selection policy.
1224 * When retransmitting timed-out data, the endpoint should
1225 * attempt to pick the most divergent source-destination
1226 * pair from the original source-destination pair to which
1227 * the packet was transmitted.
1229 * Note: Rules for picking the most divergent source-destination
1230 * pair are an implementation decision and are not specified
1231 * within this document.
1233 * Our basic strategy is to round-robin transports in priorities
1234 * according to sctp_trans_score() e.g., if no such
1235 * transport with state SCTP_ACTIVE exists, round-robin through
1236 * SCTP_UNKNOWN, etc. You get the picture.
1238 static u8 sctp_trans_score(const struct sctp_transport *trans)
1240 switch (trans->state) {
1242 return 3; /* best case */
1247 default: /* case SCTP_INACTIVE */
1248 return 0; /* worst case */
1252 static struct sctp_transport *sctp_trans_elect_tie(struct sctp_transport *trans1,
1253 struct sctp_transport *trans2)
1255 if (trans1->error_count > trans2->error_count) {
1257 } else if (trans1->error_count == trans2->error_count &&
1258 ktime_after(trans2->last_time_heard,
1259 trans1->last_time_heard)) {
1266 static struct sctp_transport *sctp_trans_elect_best(struct sctp_transport *curr,
1267 struct sctp_transport *best)
1269 u8 score_curr, score_best;
1271 if (best == NULL || curr == best)
1274 score_curr = sctp_trans_score(curr);
1275 score_best = sctp_trans_score(best);
1277 /* First, try a score-based selection if both transport states
1278 * differ. If we're in a tie, lets try to make a more clever
1279 * decision here based on error counts and last time heard.
1281 if (score_curr > score_best)
1283 else if (score_curr == score_best)
1284 return sctp_trans_elect_tie(best, curr);
1289 void sctp_assoc_update_retran_path(struct sctp_association *asoc)
1291 struct sctp_transport *trans = asoc->peer.retran_path;
1292 struct sctp_transport *trans_next = NULL;
1294 /* We're done as we only have the one and only path. */
1295 if (asoc->peer.transport_count == 1)
1297 /* If active_path and retran_path are the same and active,
1298 * then this is the only active path. Use it.
1300 if (asoc->peer.active_path == asoc->peer.retran_path &&
1301 asoc->peer.active_path->state == SCTP_ACTIVE)
1304 /* Iterate from retran_path's successor back to retran_path. */
1305 for (trans = list_next_entry(trans, transports); 1;
1306 trans = list_next_entry(trans, transports)) {
1307 /* Manually skip the head element. */
1308 if (&trans->transports == &asoc->peer.transport_addr_list)
1310 if (trans->state == SCTP_UNCONFIRMED)
1312 trans_next = sctp_trans_elect_best(trans, trans_next);
1313 /* Active is good enough for immediate return. */
1314 if (trans_next->state == SCTP_ACTIVE)
1316 /* We've reached the end, time to update path. */
1317 if (trans == asoc->peer.retran_path)
1321 asoc->peer.retran_path = trans_next;
1323 pr_debug("%s: association:%p updated new path to addr:%pISpc\n",
1324 __func__, asoc, &asoc->peer.retran_path->ipaddr.sa);
1327 static void sctp_select_active_and_retran_path(struct sctp_association *asoc)
1329 struct sctp_transport *trans, *trans_pri = NULL, *trans_sec = NULL;
1330 struct sctp_transport *trans_pf = NULL;
1332 /* Look for the two most recently used active transports. */
1333 list_for_each_entry(trans, &asoc->peer.transport_addr_list,
1335 /* Skip uninteresting transports. */
1336 if (trans->state == SCTP_INACTIVE ||
1337 trans->state == SCTP_UNCONFIRMED)
1339 /* Keep track of the best PF transport from our
1340 * list in case we don't find an active one.
1342 if (trans->state == SCTP_PF) {
1343 trans_pf = sctp_trans_elect_best(trans, trans_pf);
1346 /* For active transports, pick the most recent ones. */
1347 if (trans_pri == NULL ||
1348 ktime_after(trans->last_time_heard,
1349 trans_pri->last_time_heard)) {
1350 trans_sec = trans_pri;
1352 } else if (trans_sec == NULL ||
1353 ktime_after(trans->last_time_heard,
1354 trans_sec->last_time_heard)) {
1359 /* RFC 2960 6.4 Multi-Homed SCTP Endpoints
1361 * By default, an endpoint should always transmit to the primary
1362 * path, unless the SCTP user explicitly specifies the
1363 * destination transport address (and possibly source transport
1364 * address) to use. [If the primary is active but not most recent,
1365 * bump the most recently used transport.]
1367 if ((asoc->peer.primary_path->state == SCTP_ACTIVE ||
1368 asoc->peer.primary_path->state == SCTP_UNKNOWN) &&
1369 asoc->peer.primary_path != trans_pri) {
1370 trans_sec = trans_pri;
1371 trans_pri = asoc->peer.primary_path;
1374 /* We did not find anything useful for a possible retransmission
1375 * path; either primary path that we found is the the same as
1376 * the current one, or we didn't generally find an active one.
1378 if (trans_sec == NULL)
1379 trans_sec = trans_pri;
1381 /* If we failed to find a usable transport, just camp on the
1382 * active or pick a PF iff it's the better choice.
1384 if (trans_pri == NULL) {
1385 trans_pri = sctp_trans_elect_best(asoc->peer.active_path, trans_pf);
1386 trans_sec = trans_pri;
1389 /* Set the active and retran transports. */
1390 asoc->peer.active_path = trans_pri;
1391 asoc->peer.retran_path = trans_sec;
1394 struct sctp_transport *
1395 sctp_assoc_choose_alter_transport(struct sctp_association *asoc,
1396 struct sctp_transport *last_sent_to)
1398 /* If this is the first time packet is sent, use the active path,
1399 * else use the retran path. If the last packet was sent over the
1400 * retran path, update the retran path and use it.
1402 if (last_sent_to == NULL) {
1403 return asoc->peer.active_path;
1405 if (last_sent_to == asoc->peer.retran_path)
1406 sctp_assoc_update_retran_path(asoc);
1408 return asoc->peer.retran_path;
1412 /* Update the association's pmtu and frag_point by going through all the
1413 * transports. This routine is called when a transport's PMTU has changed.
1415 void sctp_assoc_sync_pmtu(struct sctp_association *asoc)
1417 struct sctp_transport *t;
1423 /* Get the lowest pmtu of all the transports. */
1424 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1426 if (t->pmtu_pending && t->dst) {
1427 sctp_transport_update_pmtu(
1428 t, SCTP_TRUNC4(dst_mtu(t->dst)));
1429 t->pmtu_pending = 0;
1431 if (!pmtu || (t->pathmtu < pmtu))
1436 asoc->pathmtu = pmtu;
1437 asoc->frag_point = sctp_frag_point(asoc, pmtu);
1440 pr_debug("%s: asoc:%p, pmtu:%d, frag_point:%d\n", __func__, asoc,
1441 asoc->pathmtu, asoc->frag_point);
1444 /* Should we send a SACK to update our peer? */
1445 static inline bool sctp_peer_needs_update(struct sctp_association *asoc)
1447 struct net *net = sock_net(asoc->base.sk);
1448 switch (asoc->state) {
1449 case SCTP_STATE_ESTABLISHED:
1450 case SCTP_STATE_SHUTDOWN_PENDING:
1451 case SCTP_STATE_SHUTDOWN_RECEIVED:
1452 case SCTP_STATE_SHUTDOWN_SENT:
1453 if ((asoc->rwnd > asoc->a_rwnd) &&
1454 ((asoc->rwnd - asoc->a_rwnd) >= max_t(__u32,
1455 (asoc->base.sk->sk_rcvbuf >> net->sctp.rwnd_upd_shift),
1465 /* Increase asoc's rwnd by len and send any window update SACK if needed. */
1466 void sctp_assoc_rwnd_increase(struct sctp_association *asoc, unsigned int len)
1468 struct sctp_chunk *sack;
1469 struct timer_list *timer;
1471 if (asoc->rwnd_over) {
1472 if (asoc->rwnd_over >= len) {
1473 asoc->rwnd_over -= len;
1475 asoc->rwnd += (len - asoc->rwnd_over);
1476 asoc->rwnd_over = 0;
1482 /* If we had window pressure, start recovering it
1483 * once our rwnd had reached the accumulated pressure
1484 * threshold. The idea is to recover slowly, but up
1485 * to the initial advertised window.
1487 if (asoc->rwnd_press) {
1488 int change = min(asoc->pathmtu, asoc->rwnd_press);
1489 asoc->rwnd += change;
1490 asoc->rwnd_press -= change;
1493 pr_debug("%s: asoc:%p rwnd increased by %d to (%u, %u) - %u\n",
1494 __func__, asoc, len, asoc->rwnd, asoc->rwnd_over,
1497 /* Send a window update SACK if the rwnd has increased by at least the
1498 * minimum of the association's PMTU and half of the receive buffer.
1499 * The algorithm used is similar to the one described in
1500 * Section 4.2.3.3 of RFC 1122.
1502 if (sctp_peer_needs_update(asoc)) {
1503 asoc->a_rwnd = asoc->rwnd;
1505 pr_debug("%s: sending window update SACK- asoc:%p rwnd:%u "
1506 "a_rwnd:%u\n", __func__, asoc, asoc->rwnd,
1509 sack = sctp_make_sack(asoc);
1513 asoc->peer.sack_needed = 0;
1515 sctp_outq_tail(&asoc->outqueue, sack, GFP_ATOMIC);
1517 /* Stop the SACK timer. */
1518 timer = &asoc->timers[SCTP_EVENT_TIMEOUT_SACK];
1519 if (del_timer(timer))
1520 sctp_association_put(asoc);
1524 /* Decrease asoc's rwnd by len. */
1525 void sctp_assoc_rwnd_decrease(struct sctp_association *asoc, unsigned int len)
1530 if (unlikely(!asoc->rwnd || asoc->rwnd_over))
1531 pr_debug("%s: association:%p has asoc->rwnd:%u, "
1532 "asoc->rwnd_over:%u!\n", __func__, asoc,
1533 asoc->rwnd, asoc->rwnd_over);
1535 if (asoc->ep->rcvbuf_policy)
1536 rx_count = atomic_read(&asoc->rmem_alloc);
1538 rx_count = atomic_read(&asoc->base.sk->sk_rmem_alloc);
1540 /* If we've reached or overflowed our receive buffer, announce
1541 * a 0 rwnd if rwnd would still be positive. Store the
1542 * the potential pressure overflow so that the window can be restored
1543 * back to original value.
1545 if (rx_count >= asoc->base.sk->sk_rcvbuf)
1548 if (asoc->rwnd >= len) {
1551 asoc->rwnd_press += asoc->rwnd;
1555 asoc->rwnd_over += len - asoc->rwnd;
1559 pr_debug("%s: asoc:%p rwnd decreased by %d to (%u, %u, %u)\n",
1560 __func__, asoc, len, asoc->rwnd, asoc->rwnd_over,
1564 /* Build the bind address list for the association based on info from the
1565 * local endpoint and the remote peer.
1567 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
1568 sctp_scope_t scope, gfp_t gfp)
1572 /* Use scoping rules to determine the subset of addresses from
1575 flags = (PF_INET6 == asoc->base.sk->sk_family) ? SCTP_ADDR6_ALLOWED : 0;
1576 if (asoc->peer.ipv4_address)
1577 flags |= SCTP_ADDR4_PEERSUPP;
1578 if (asoc->peer.ipv6_address)
1579 flags |= SCTP_ADDR6_PEERSUPP;
1581 return sctp_bind_addr_copy(sock_net(asoc->base.sk),
1582 &asoc->base.bind_addr,
1583 &asoc->ep->base.bind_addr,
1587 /* Build the association's bind address list from the cookie. */
1588 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *asoc,
1589 struct sctp_cookie *cookie,
1592 int var_size2 = ntohs(cookie->peer_init->chunk_hdr.length);
1593 int var_size3 = cookie->raw_addr_list_len;
1594 __u8 *raw = (__u8 *)cookie->peer_init + var_size2;
1596 return sctp_raw_to_bind_addrs(&asoc->base.bind_addr, raw, var_size3,
1597 asoc->ep->base.bind_addr.port, gfp);
1600 /* Lookup laddr in the bind address list of an association. */
1601 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
1602 const union sctp_addr *laddr)
1606 if ((asoc->base.bind_addr.port == ntohs(laddr->v4.sin_port)) &&
1607 sctp_bind_addr_match(&asoc->base.bind_addr, laddr,
1608 sctp_sk(asoc->base.sk)))
1614 /* Set an association id for a given association */
1615 int sctp_assoc_set_id(struct sctp_association *asoc, gfp_t gfp)
1617 bool preload = gfpflags_allow_blocking(gfp);
1620 /* If the id is already assigned, keep it. */
1626 spin_lock_bh(&sctp_assocs_id_lock);
1627 /* 0 is not a valid assoc_id, must be >= 1 */
1628 ret = idr_alloc_cyclic(&sctp_assocs_id, asoc, 1, 0, GFP_NOWAIT);
1629 spin_unlock_bh(&sctp_assocs_id_lock);
1635 asoc->assoc_id = (sctp_assoc_t)ret;
1639 /* Free the ASCONF queue */
1640 static void sctp_assoc_free_asconf_queue(struct sctp_association *asoc)
1642 struct sctp_chunk *asconf;
1643 struct sctp_chunk *tmp;
1645 list_for_each_entry_safe(asconf, tmp, &asoc->addip_chunk_list, list) {
1646 list_del_init(&asconf->list);
1647 sctp_chunk_free(asconf);
1651 /* Free asconf_ack cache */
1652 static void sctp_assoc_free_asconf_acks(struct sctp_association *asoc)
1654 struct sctp_chunk *ack;
1655 struct sctp_chunk *tmp;
1657 list_for_each_entry_safe(ack, tmp, &asoc->asconf_ack_list,
1659 list_del_init(&ack->transmitted_list);
1660 sctp_chunk_free(ack);
1664 /* Clean up the ASCONF_ACK queue */
1665 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc)
1667 struct sctp_chunk *ack;
1668 struct sctp_chunk *tmp;
1670 /* We can remove all the entries from the queue up to
1671 * the "Peer-Sequence-Number".
1673 list_for_each_entry_safe(ack, tmp, &asoc->asconf_ack_list,
1675 if (ack->subh.addip_hdr->serial ==
1676 htonl(asoc->peer.addip_serial))
1679 list_del_init(&ack->transmitted_list);
1680 sctp_chunk_free(ack);
1684 /* Find the ASCONF_ACK whose serial number matches ASCONF */
1685 struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
1686 const struct sctp_association *asoc,
1689 struct sctp_chunk *ack;
1691 /* Walk through the list of cached ASCONF-ACKs and find the
1692 * ack chunk whose serial number matches that of the request.
1694 list_for_each_entry(ack, &asoc->asconf_ack_list, transmitted_list) {
1695 if (sctp_chunk_pending(ack))
1697 if (ack->subh.addip_hdr->serial == serial) {
1698 sctp_chunk_hold(ack);
1706 void sctp_asconf_queue_teardown(struct sctp_association *asoc)
1708 /* Free any cached ASCONF_ACK chunk. */
1709 sctp_assoc_free_asconf_acks(asoc);
1711 /* Free the ASCONF queue. */
1712 sctp_assoc_free_asconf_queue(asoc);
1714 /* Free any cached ASCONF chunk. */
1715 if (asoc->addip_last_asconf)
1716 sctp_chunk_free(asoc->addip_last_asconf);