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 /* Assume that peer would support both address types unless we are
252 asoc->peer.ipv4_address = 1;
253 if (asoc->base.sk->sk_family == PF_INET6)
254 asoc->peer.ipv6_address = 1;
255 INIT_LIST_HEAD(&asoc->asocs);
257 asoc->default_stream = sp->default_stream;
258 asoc->default_ppid = sp->default_ppid;
259 asoc->default_flags = sp->default_flags;
260 asoc->default_context = sp->default_context;
261 asoc->default_timetolive = sp->default_timetolive;
262 asoc->default_rcv_context = sp->default_rcv_context;
264 /* AUTH related initializations */
265 INIT_LIST_HEAD(&asoc->endpoint_shared_keys);
266 if (sctp_auth_asoc_copy_shkeys(ep, asoc, gfp))
269 asoc->active_key_id = ep->active_key_id;
270 asoc->prsctp_enable = ep->prsctp_enable;
271 asoc->reconf_enable = ep->reconf_enable;
272 asoc->strreset_enable = ep->strreset_enable;
274 /* Save the hmacs and chunks list into this association */
275 if (ep->auth_hmacs_list)
276 memcpy(asoc->c.auth_hmacs, ep->auth_hmacs_list,
277 ntohs(ep->auth_hmacs_list->param_hdr.length));
278 if (ep->auth_chunk_list)
279 memcpy(asoc->c.auth_chunks, ep->auth_chunk_list,
280 ntohs(ep->auth_chunk_list->param_hdr.length));
282 /* Get the AUTH random number for this association */
283 p = (sctp_paramhdr_t *)asoc->c.auth_random;
284 p->type = SCTP_PARAM_RANDOM;
285 p->length = htons(sizeof(sctp_paramhdr_t) + SCTP_AUTH_RANDOM_LENGTH);
286 get_random_bytes(p+1, SCTP_AUTH_RANDOM_LENGTH);
291 sock_put(asoc->base.sk);
292 sctp_endpoint_put(asoc->ep);
296 /* Allocate and initialize a new association */
297 struct sctp_association *sctp_association_new(const struct sctp_endpoint *ep,
298 const struct sock *sk,
302 struct sctp_association *asoc;
304 asoc = kzalloc(sizeof(*asoc), gfp);
308 if (!sctp_association_init(asoc, ep, sk, scope, gfp))
311 SCTP_DBG_OBJCNT_INC(assoc);
313 pr_debug("Created asoc %p\n", asoc);
323 /* Free this association if possible. There may still be users, so
324 * the actual deallocation may be delayed.
326 void sctp_association_free(struct sctp_association *asoc)
328 struct sock *sk = asoc->base.sk;
329 struct sctp_transport *transport;
330 struct list_head *pos, *temp;
333 /* Only real associations count against the endpoint, so
334 * don't bother for if this is a temporary association.
336 if (!list_empty(&asoc->asocs)) {
337 list_del(&asoc->asocs);
339 /* Decrement the backlog value for a TCP-style listening
342 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
343 sk->sk_ack_backlog--;
346 /* Mark as dead, so other users can know this structure is
349 asoc->base.dead = true;
351 /* Dispose of any data lying around in the outqueue. */
352 sctp_outq_free(&asoc->outqueue);
354 /* Dispose of any pending messages for the upper layer. */
355 sctp_ulpq_free(&asoc->ulpq);
357 /* Dispose of any pending chunks on the inqueue. */
358 sctp_inq_free(&asoc->base.inqueue);
360 sctp_tsnmap_free(&asoc->peer.tsn_map);
362 /* Free stream information. */
363 sctp_stream_free(asoc->stream);
365 if (asoc->strreset_chunk)
366 sctp_chunk_free(asoc->strreset_chunk);
368 /* Clean up the bound address list. */
369 sctp_bind_addr_free(&asoc->base.bind_addr);
371 /* Do we need to go through all of our timers and
372 * delete them? To be safe we will try to delete all, but we
373 * should be able to go through and make a guess based
376 for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i) {
377 if (del_timer(&asoc->timers[i]))
378 sctp_association_put(asoc);
381 /* Free peer's cached cookie. */
382 kfree(asoc->peer.cookie);
383 kfree(asoc->peer.peer_random);
384 kfree(asoc->peer.peer_chunks);
385 kfree(asoc->peer.peer_hmacs);
387 /* Release the transport structures. */
388 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
389 transport = list_entry(pos, struct sctp_transport, transports);
391 sctp_unhash_transport(transport);
392 sctp_transport_free(transport);
395 asoc->peer.transport_count = 0;
397 sctp_asconf_queue_teardown(asoc);
399 /* Free pending address space being deleted */
400 kfree(asoc->asconf_addr_del_pending);
402 /* AUTH - Free the endpoint shared keys */
403 sctp_auth_destroy_keys(&asoc->endpoint_shared_keys);
405 /* AUTH - Free the association shared key */
406 sctp_auth_key_put(asoc->asoc_shared_key);
408 sctp_association_put(asoc);
411 /* Cleanup and free up an association. */
412 static void sctp_association_destroy(struct sctp_association *asoc)
414 if (unlikely(!asoc->base.dead)) {
415 WARN(1, "Attempt to destroy undead association %p!\n", asoc);
419 sctp_endpoint_put(asoc->ep);
420 sock_put(asoc->base.sk);
422 if (asoc->assoc_id != 0) {
423 spin_lock_bh(&sctp_assocs_id_lock);
424 idr_remove(&sctp_assocs_id, asoc->assoc_id);
425 spin_unlock_bh(&sctp_assocs_id_lock);
428 WARN_ON(atomic_read(&asoc->rmem_alloc));
431 SCTP_DBG_OBJCNT_DEC(assoc);
434 /* Change the primary destination address for the peer. */
435 void sctp_assoc_set_primary(struct sctp_association *asoc,
436 struct sctp_transport *transport)
440 /* it's a changeover only if we already have a primary path
441 * that we are changing
443 if (asoc->peer.primary_path != NULL &&
444 asoc->peer.primary_path != transport)
447 asoc->peer.primary_path = transport;
449 /* Set a default msg_name for events. */
450 memcpy(&asoc->peer.primary_addr, &transport->ipaddr,
451 sizeof(union sctp_addr));
453 /* If the primary path is changing, assume that the
454 * user wants to use this new path.
456 if ((transport->state == SCTP_ACTIVE) ||
457 (transport->state == SCTP_UNKNOWN))
458 asoc->peer.active_path = transport;
461 * SFR-CACC algorithm:
462 * Upon the receipt of a request to change the primary
463 * destination address, on the data structure for the new
464 * primary destination, the sender MUST do the following:
466 * 1) If CHANGEOVER_ACTIVE is set, then there was a switch
467 * to this destination address earlier. The sender MUST set
468 * CYCLING_CHANGEOVER to indicate that this switch is a
469 * double switch to the same destination address.
471 * Really, only bother is we have data queued or outstanding on
474 if (!asoc->outqueue.outstanding_bytes && !asoc->outqueue.out_qlen)
477 if (transport->cacc.changeover_active)
478 transport->cacc.cycling_changeover = changeover;
480 /* 2) The sender MUST set CHANGEOVER_ACTIVE to indicate that
481 * a changeover has occurred.
483 transport->cacc.changeover_active = changeover;
485 /* 3) The sender MUST store the next TSN to be sent in
486 * next_tsn_at_change.
488 transport->cacc.next_tsn_at_change = asoc->next_tsn;
491 /* Remove a transport from an association. */
492 void sctp_assoc_rm_peer(struct sctp_association *asoc,
493 struct sctp_transport *peer)
495 struct list_head *pos;
496 struct sctp_transport *transport;
498 pr_debug("%s: association:%p addr:%pISpc\n",
499 __func__, asoc, &peer->ipaddr.sa);
501 /* If we are to remove the current retran_path, update it
502 * to the next peer before removing this peer from the list.
504 if (asoc->peer.retran_path == peer)
505 sctp_assoc_update_retran_path(asoc);
507 /* Remove this peer from the list. */
508 list_del_rcu(&peer->transports);
509 /* Remove this peer from the transport hashtable */
510 sctp_unhash_transport(peer);
512 /* Get the first transport of asoc. */
513 pos = asoc->peer.transport_addr_list.next;
514 transport = list_entry(pos, struct sctp_transport, transports);
516 /* Update any entries that match the peer to be deleted. */
517 if (asoc->peer.primary_path == peer)
518 sctp_assoc_set_primary(asoc, transport);
519 if (asoc->peer.active_path == peer)
520 asoc->peer.active_path = transport;
521 if (asoc->peer.retran_path == peer)
522 asoc->peer.retran_path = transport;
523 if (asoc->peer.last_data_from == peer)
524 asoc->peer.last_data_from = transport;
526 if (asoc->strreset_chunk &&
527 asoc->strreset_chunk->transport == peer) {
528 asoc->strreset_chunk->transport = transport;
529 sctp_transport_reset_reconf_timer(transport);
532 /* If we remove the transport an INIT was last sent to, set it to
533 * NULL. Combined with the update of the retran path above, this
534 * will cause the next INIT to be sent to the next available
535 * transport, maintaining the cycle.
537 if (asoc->init_last_sent_to == peer)
538 asoc->init_last_sent_to = NULL;
540 /* If we remove the transport an SHUTDOWN was last sent to, set it
541 * to NULL. Combined with the update of the retran path above, this
542 * will cause the next SHUTDOWN to be sent to the next available
543 * transport, maintaining the cycle.
545 if (asoc->shutdown_last_sent_to == peer)
546 asoc->shutdown_last_sent_to = NULL;
548 /* If we remove the transport an ASCONF was last sent to, set it to
551 if (asoc->addip_last_asconf &&
552 asoc->addip_last_asconf->transport == peer)
553 asoc->addip_last_asconf->transport = NULL;
555 /* If we have something on the transmitted list, we have to
556 * save it off. The best place is the active path.
558 if (!list_empty(&peer->transmitted)) {
559 struct sctp_transport *active = asoc->peer.active_path;
560 struct sctp_chunk *ch;
562 /* Reset the transport of each chunk on this list */
563 list_for_each_entry(ch, &peer->transmitted,
565 ch->transport = NULL;
566 ch->rtt_in_progress = 0;
569 list_splice_tail_init(&peer->transmitted,
570 &active->transmitted);
572 /* Start a T3 timer here in case it wasn't running so
573 * that these migrated packets have a chance to get
576 if (!timer_pending(&active->T3_rtx_timer))
577 if (!mod_timer(&active->T3_rtx_timer,
578 jiffies + active->rto))
579 sctp_transport_hold(active);
582 asoc->peer.transport_count--;
584 sctp_transport_free(peer);
587 /* Add a transport address to an association. */
588 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc,
589 const union sctp_addr *addr,
591 const int peer_state)
593 struct net *net = sock_net(asoc->base.sk);
594 struct sctp_transport *peer;
595 struct sctp_sock *sp;
598 sp = sctp_sk(asoc->base.sk);
600 /* AF_INET and AF_INET6 share common port field. */
601 port = ntohs(addr->v4.sin_port);
603 pr_debug("%s: association:%p addr:%pISpc state:%d\n", __func__,
604 asoc, &addr->sa, peer_state);
606 /* Set the port if it has not been set yet. */
607 if (0 == asoc->peer.port)
608 asoc->peer.port = port;
610 /* Check to see if this is a duplicate. */
611 peer = sctp_assoc_lookup_paddr(asoc, addr);
613 /* An UNKNOWN state is only set on transports added by
614 * user in sctp_connectx() call. Such transports should be
615 * considered CONFIRMED per RFC 4960, Section 5.4.
617 if (peer->state == SCTP_UNKNOWN) {
618 peer->state = SCTP_ACTIVE;
623 peer = sctp_transport_new(net, addr, gfp);
627 sctp_transport_set_owner(peer, asoc);
629 /* Initialize the peer's heartbeat interval based on the
630 * association configured value.
632 peer->hbinterval = asoc->hbinterval;
634 /* Set the path max_retrans. */
635 peer->pathmaxrxt = asoc->pathmaxrxt;
637 /* And the partial failure retrans threshold */
638 peer->pf_retrans = asoc->pf_retrans;
640 /* Initialize the peer's SACK delay timeout based on the
641 * association configured value.
643 peer->sackdelay = asoc->sackdelay;
644 peer->sackfreq = asoc->sackfreq;
646 /* Enable/disable heartbeat, SACK delay, and path MTU discovery
647 * based on association setting.
649 peer->param_flags = asoc->param_flags;
651 sctp_transport_route(peer, NULL, sp);
653 /* Initialize the pmtu of the transport. */
654 if (peer->param_flags & SPP_PMTUD_DISABLE) {
656 peer->pathmtu = asoc->pathmtu;
658 peer->pathmtu = SCTP_DEFAULT_MAXSEGMENT;
661 /* If this is the first transport addr on this association,
662 * initialize the association PMTU to the peer's PMTU.
663 * If not and the current association PMTU is higher than the new
664 * peer's PMTU, reset the association PMTU to the new peer's PMTU.
667 asoc->pathmtu = min_t(int, peer->pathmtu, asoc->pathmtu);
669 asoc->pathmtu = peer->pathmtu;
671 pr_debug("%s: association:%p PMTU set to %d\n", __func__, asoc,
674 peer->pmtu_pending = 0;
676 asoc->frag_point = sctp_frag_point(asoc, asoc->pathmtu);
678 /* The asoc->peer.port might not be meaningful yet, but
679 * initialize the packet structure anyway.
681 sctp_packet_init(&peer->packet, peer, asoc->base.bind_addr.port,
686 * o The initial cwnd before DATA transmission or after a sufficiently
687 * long idle period MUST be set to
688 * min(4*MTU, max(2*MTU, 4380 bytes))
690 * o The initial value of ssthresh MAY be arbitrarily high
691 * (for example, implementations MAY use the size of the
692 * receiver advertised window).
694 peer->cwnd = min(4*asoc->pathmtu, max_t(__u32, 2*asoc->pathmtu, 4380));
696 /* At this point, we may not have the receiver's advertised window,
697 * so initialize ssthresh to the default value and it will be set
698 * later when we process the INIT.
700 peer->ssthresh = SCTP_DEFAULT_MAXWINDOW;
702 peer->partial_bytes_acked = 0;
703 peer->flight_size = 0;
704 peer->burst_limited = 0;
706 /* Set the transport's RTO.initial value */
707 peer->rto = asoc->rto_initial;
708 sctp_max_rto(asoc, peer);
710 /* Set the peer's active state. */
711 peer->state = peer_state;
713 /* Add this peer into the transport hashtable */
714 if (sctp_hash_transport(peer)) {
715 sctp_transport_free(peer);
719 /* Attach the remote transport to our asoc. */
720 list_add_tail_rcu(&peer->transports, &asoc->peer.transport_addr_list);
721 asoc->peer.transport_count++;
723 /* If we do not yet have a primary path, set one. */
724 if (!asoc->peer.primary_path) {
725 sctp_assoc_set_primary(asoc, peer);
726 asoc->peer.retran_path = peer;
729 if (asoc->peer.active_path == asoc->peer.retran_path &&
730 peer->state != SCTP_UNCONFIRMED) {
731 asoc->peer.retran_path = peer;
737 /* Delete a transport address from an association. */
738 void sctp_assoc_del_peer(struct sctp_association *asoc,
739 const union sctp_addr *addr)
741 struct list_head *pos;
742 struct list_head *temp;
743 struct sctp_transport *transport;
745 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
746 transport = list_entry(pos, struct sctp_transport, transports);
747 if (sctp_cmp_addr_exact(addr, &transport->ipaddr)) {
748 /* Do book keeping for removing the peer and free it. */
749 sctp_assoc_rm_peer(asoc, transport);
755 /* Lookup a transport by address. */
756 struct sctp_transport *sctp_assoc_lookup_paddr(
757 const struct sctp_association *asoc,
758 const union sctp_addr *address)
760 struct sctp_transport *t;
762 /* Cycle through all transports searching for a peer address. */
764 list_for_each_entry(t, &asoc->peer.transport_addr_list,
766 if (sctp_cmp_addr_exact(address, &t->ipaddr))
773 /* Remove all transports except a give one */
774 void sctp_assoc_del_nonprimary_peers(struct sctp_association *asoc,
775 struct sctp_transport *primary)
777 struct sctp_transport *temp;
778 struct sctp_transport *t;
780 list_for_each_entry_safe(t, temp, &asoc->peer.transport_addr_list,
782 /* if the current transport is not the primary one, delete it */
784 sctp_assoc_rm_peer(asoc, t);
788 /* Engage in transport control operations.
789 * Mark the transport up or down and send a notification to the user.
790 * Select and update the new active and retran paths.
792 void sctp_assoc_control_transport(struct sctp_association *asoc,
793 struct sctp_transport *transport,
794 sctp_transport_cmd_t command,
795 sctp_sn_error_t error)
797 struct sctp_ulpevent *event;
798 struct sockaddr_storage addr;
800 bool ulp_notify = true;
802 /* Record the transition on the transport. */
804 case SCTP_TRANSPORT_UP:
805 /* If we are moving from UNCONFIRMED state due
806 * to heartbeat success, report the SCTP_ADDR_CONFIRMED
807 * state to the user, otherwise report SCTP_ADDR_AVAILABLE.
809 if (SCTP_UNCONFIRMED == transport->state &&
810 SCTP_HEARTBEAT_SUCCESS == error)
811 spc_state = SCTP_ADDR_CONFIRMED;
813 spc_state = SCTP_ADDR_AVAILABLE;
814 /* Don't inform ULP about transition from PF to
815 * active state and set cwnd to 1 MTU, see SCTP
816 * Quick failover draft section 5.1, point 5
818 if (transport->state == SCTP_PF) {
820 transport->cwnd = asoc->pathmtu;
822 transport->state = SCTP_ACTIVE;
825 case SCTP_TRANSPORT_DOWN:
826 /* If the transport was never confirmed, do not transition it
827 * to inactive state. Also, release the cached route since
828 * there may be a better route next time.
830 if (transport->state != SCTP_UNCONFIRMED)
831 transport->state = SCTP_INACTIVE;
833 sctp_transport_dst_release(transport);
837 spc_state = SCTP_ADDR_UNREACHABLE;
840 case SCTP_TRANSPORT_PF:
841 transport->state = SCTP_PF;
849 /* Generate and send a SCTP_PEER_ADDR_CHANGE notification
853 memset(&addr, 0, sizeof(struct sockaddr_storage));
854 memcpy(&addr, &transport->ipaddr,
855 transport->af_specific->sockaddr_len);
857 event = sctp_ulpevent_make_peer_addr_change(asoc, &addr,
858 0, spc_state, error, GFP_ATOMIC);
860 sctp_ulpq_tail_event(&asoc->ulpq, event);
863 /* Select new active and retran paths. */
864 sctp_select_active_and_retran_path(asoc);
867 /* Hold a reference to an association. */
868 void sctp_association_hold(struct sctp_association *asoc)
870 atomic_inc(&asoc->base.refcnt);
873 /* Release a reference to an association and cleanup
874 * if there are no more references.
876 void sctp_association_put(struct sctp_association *asoc)
878 if (atomic_dec_and_test(&asoc->base.refcnt))
879 sctp_association_destroy(asoc);
882 /* Allocate the next TSN, Transmission Sequence Number, for the given
885 __u32 sctp_association_get_next_tsn(struct sctp_association *asoc)
887 /* From Section 1.6 Serial Number Arithmetic:
888 * Transmission Sequence Numbers wrap around when they reach
889 * 2**32 - 1. That is, the next TSN a DATA chunk MUST use
890 * after transmitting TSN = 2*32 - 1 is TSN = 0.
892 __u32 retval = asoc->next_tsn;
899 /* Compare two addresses to see if they match. Wildcard addresses
900 * only match themselves.
902 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
903 const union sctp_addr *ss2)
907 af = sctp_get_af_specific(ss1->sa.sa_family);
911 return af->cmp_addr(ss1, ss2);
914 /* Return an ecne chunk to get prepended to a packet.
915 * Note: We are sly and return a shared, prealloced chunk. FIXME:
916 * No we don't, but we could/should.
918 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc)
920 if (!asoc->need_ecne)
923 /* Send ECNE if needed.
924 * Not being able to allocate a chunk here is not deadly.
926 return sctp_make_ecne(asoc, asoc->last_ecne_tsn);
930 * Find which transport this TSN was sent on.
932 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *asoc,
935 struct sctp_transport *active;
936 struct sctp_transport *match;
937 struct sctp_transport *transport;
938 struct sctp_chunk *chunk;
939 __be32 key = htonl(tsn);
944 * FIXME: In general, find a more efficient data structure for
949 * The general strategy is to search each transport's transmitted
950 * list. Return which transport this TSN lives on.
952 * Let's be hopeful and check the active_path first.
953 * Another optimization would be to know if there is only one
954 * outbound path and not have to look for the TSN at all.
958 active = asoc->peer.active_path;
960 list_for_each_entry(chunk, &active->transmitted,
963 if (key == chunk->subh.data_hdr->tsn) {
969 /* If not found, go search all the other transports. */
970 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
973 if (transport == active)
975 list_for_each_entry(chunk, &transport->transmitted,
977 if (key == chunk->subh.data_hdr->tsn) {
987 /* Is this the association we are looking for? */
988 struct sctp_transport *sctp_assoc_is_match(struct sctp_association *asoc,
990 const union sctp_addr *laddr,
991 const union sctp_addr *paddr)
993 struct sctp_transport *transport;
995 if ((htons(asoc->base.bind_addr.port) == laddr->v4.sin_port) &&
996 (htons(asoc->peer.port) == paddr->v4.sin_port) &&
997 net_eq(sock_net(asoc->base.sk), net)) {
998 transport = sctp_assoc_lookup_paddr(asoc, paddr);
1002 if (sctp_bind_addr_match(&asoc->base.bind_addr, laddr,
1003 sctp_sk(asoc->base.sk)))
1012 /* Do delayed input processing. This is scheduled by sctp_rcv(). */
1013 static void sctp_assoc_bh_rcv(struct work_struct *work)
1015 struct sctp_association *asoc =
1016 container_of(work, struct sctp_association,
1017 base.inqueue.immediate);
1018 struct net *net = sock_net(asoc->base.sk);
1019 struct sctp_endpoint *ep;
1020 struct sctp_chunk *chunk;
1021 struct sctp_inq *inqueue;
1023 sctp_subtype_t subtype;
1026 /* The association should be held so we should be safe. */
1029 inqueue = &asoc->base.inqueue;
1030 sctp_association_hold(asoc);
1031 while (NULL != (chunk = sctp_inq_pop(inqueue))) {
1032 state = asoc->state;
1033 subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type);
1035 /* SCTP-AUTH, Section 6.3:
1036 * The receiver has a list of chunk types which it expects
1037 * to be received only after an AUTH-chunk. This list has
1038 * been sent to the peer during the association setup. It
1039 * MUST silently discard these chunks if they are not placed
1040 * after an AUTH chunk in the packet.
1042 if (sctp_auth_recv_cid(subtype.chunk, asoc) && !chunk->auth)
1045 /* Remember where the last DATA chunk came from so we
1046 * know where to send the SACK.
1048 if (sctp_chunk_is_data(chunk))
1049 asoc->peer.last_data_from = chunk->transport;
1051 SCTP_INC_STATS(net, SCTP_MIB_INCTRLCHUNKS);
1052 asoc->stats.ictrlchunks++;
1053 if (chunk->chunk_hdr->type == SCTP_CID_SACK)
1054 asoc->stats.isacks++;
1057 if (chunk->transport)
1058 chunk->transport->last_time_heard = ktime_get();
1060 /* Run through the state machine. */
1061 error = sctp_do_sm(net, SCTP_EVENT_T_CHUNK, subtype,
1062 state, ep, asoc, chunk, GFP_ATOMIC);
1064 /* Check to see if the association is freed in response to
1065 * the incoming chunk. If so, get out of the while loop.
1067 if (asoc->base.dead)
1070 /* If there is an error on chunk, discard this packet. */
1072 chunk->pdiscard = 1;
1074 sctp_association_put(asoc);
1077 /* This routine moves an association from its old sk to a new sk. */
1078 void sctp_assoc_migrate(struct sctp_association *assoc, struct sock *newsk)
1080 struct sctp_sock *newsp = sctp_sk(newsk);
1081 struct sock *oldsk = assoc->base.sk;
1083 /* Delete the association from the old endpoint's list of
1086 list_del_init(&assoc->asocs);
1088 /* Decrement the backlog value for a TCP-style socket. */
1089 if (sctp_style(oldsk, TCP))
1090 oldsk->sk_ack_backlog--;
1092 /* Release references to the old endpoint and the sock. */
1093 sctp_endpoint_put(assoc->ep);
1094 sock_put(assoc->base.sk);
1096 /* Get a reference to the new endpoint. */
1097 assoc->ep = newsp->ep;
1098 sctp_endpoint_hold(assoc->ep);
1100 /* Get a reference to the new sock. */
1101 assoc->base.sk = newsk;
1102 sock_hold(assoc->base.sk);
1104 /* Add the association to the new endpoint's list of associations. */
1105 sctp_endpoint_add_asoc(newsp->ep, assoc);
1108 /* Update an association (possibly from unexpected COOKIE-ECHO processing). */
1109 void sctp_assoc_update(struct sctp_association *asoc,
1110 struct sctp_association *new)
1112 struct sctp_transport *trans;
1113 struct list_head *pos, *temp;
1115 /* Copy in new parameters of peer. */
1117 asoc->peer.rwnd = new->peer.rwnd;
1118 asoc->peer.sack_needed = new->peer.sack_needed;
1119 asoc->peer.auth_capable = new->peer.auth_capable;
1120 asoc->peer.i = new->peer.i;
1121 sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
1122 asoc->peer.i.initial_tsn, GFP_ATOMIC);
1124 /* Remove any peer addresses not present in the new association. */
1125 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
1126 trans = list_entry(pos, struct sctp_transport, transports);
1127 if (!sctp_assoc_lookup_paddr(new, &trans->ipaddr)) {
1128 sctp_assoc_rm_peer(asoc, trans);
1132 if (asoc->state >= SCTP_STATE_ESTABLISHED)
1133 sctp_transport_reset(trans);
1136 /* If the case is A (association restart), use
1137 * initial_tsn as next_tsn. If the case is B, use
1138 * current next_tsn in case data sent to peer
1139 * has been discarded and needs retransmission.
1141 if (asoc->state >= SCTP_STATE_ESTABLISHED) {
1142 asoc->next_tsn = new->next_tsn;
1143 asoc->ctsn_ack_point = new->ctsn_ack_point;
1144 asoc->adv_peer_ack_point = new->adv_peer_ack_point;
1146 /* Reinitialize SSN for both local streams
1147 * and peer's streams.
1149 sctp_stream_clear(asoc->stream);
1151 /* Flush the ULP reassembly and ordered queue.
1152 * Any data there will now be stale and will
1155 sctp_ulpq_flush(&asoc->ulpq);
1157 /* reset the overall association error count so
1158 * that the restarted association doesn't get torn
1159 * down on the next retransmission timer.
1161 asoc->overall_error_count = 0;
1164 /* Add any peer addresses from the new association. */
1165 list_for_each_entry(trans, &new->peer.transport_addr_list,
1167 if (!sctp_assoc_lookup_paddr(asoc, &trans->ipaddr))
1168 sctp_assoc_add_peer(asoc, &trans->ipaddr,
1169 GFP_ATOMIC, trans->state);
1172 asoc->ctsn_ack_point = asoc->next_tsn - 1;
1173 asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
1174 if (!asoc->stream) {
1175 asoc->stream = new->stream;
1179 if (!asoc->assoc_id) {
1180 /* get a new association id since we don't have one
1183 sctp_assoc_set_id(asoc, GFP_ATOMIC);
1187 /* SCTP-AUTH: Save the peer parameters from the new associations
1188 * and also move the association shared keys over
1190 kfree(asoc->peer.peer_random);
1191 asoc->peer.peer_random = new->peer.peer_random;
1192 new->peer.peer_random = NULL;
1194 kfree(asoc->peer.peer_chunks);
1195 asoc->peer.peer_chunks = new->peer.peer_chunks;
1196 new->peer.peer_chunks = NULL;
1198 kfree(asoc->peer.peer_hmacs);
1199 asoc->peer.peer_hmacs = new->peer.peer_hmacs;
1200 new->peer.peer_hmacs = NULL;
1202 sctp_auth_asoc_init_active_key(asoc, GFP_ATOMIC);
1205 /* Update the retran path for sending a retransmitted packet.
1206 * See also RFC4960, 6.4. Multi-Homed SCTP Endpoints:
1208 * When there is outbound data to send and the primary path
1209 * becomes inactive (e.g., due to failures), or where the
1210 * SCTP user explicitly requests to send data to an
1211 * inactive destination transport address, before reporting
1212 * an error to its ULP, the SCTP endpoint should try to send
1213 * the data to an alternate active destination transport
1214 * address if one exists.
1216 * When retransmitting data that timed out, if the endpoint
1217 * is multihomed, it should consider each source-destination
1218 * address pair in its retransmission selection policy.
1219 * When retransmitting timed-out data, the endpoint should
1220 * attempt to pick the most divergent source-destination
1221 * pair from the original source-destination pair to which
1222 * the packet was transmitted.
1224 * Note: Rules for picking the most divergent source-destination
1225 * pair are an implementation decision and are not specified
1226 * within this document.
1228 * Our basic strategy is to round-robin transports in priorities
1229 * according to sctp_trans_score() e.g., if no such
1230 * transport with state SCTP_ACTIVE exists, round-robin through
1231 * SCTP_UNKNOWN, etc. You get the picture.
1233 static u8 sctp_trans_score(const struct sctp_transport *trans)
1235 switch (trans->state) {
1237 return 3; /* best case */
1242 default: /* case SCTP_INACTIVE */
1243 return 0; /* worst case */
1247 static struct sctp_transport *sctp_trans_elect_tie(struct sctp_transport *trans1,
1248 struct sctp_transport *trans2)
1250 if (trans1->error_count > trans2->error_count) {
1252 } else if (trans1->error_count == trans2->error_count &&
1253 ktime_after(trans2->last_time_heard,
1254 trans1->last_time_heard)) {
1261 static struct sctp_transport *sctp_trans_elect_best(struct sctp_transport *curr,
1262 struct sctp_transport *best)
1264 u8 score_curr, score_best;
1266 if (best == NULL || curr == best)
1269 score_curr = sctp_trans_score(curr);
1270 score_best = sctp_trans_score(best);
1272 /* First, try a score-based selection if both transport states
1273 * differ. If we're in a tie, lets try to make a more clever
1274 * decision here based on error counts and last time heard.
1276 if (score_curr > score_best)
1278 else if (score_curr == score_best)
1279 return sctp_trans_elect_tie(best, curr);
1284 void sctp_assoc_update_retran_path(struct sctp_association *asoc)
1286 struct sctp_transport *trans = asoc->peer.retran_path;
1287 struct sctp_transport *trans_next = NULL;
1289 /* We're done as we only have the one and only path. */
1290 if (asoc->peer.transport_count == 1)
1292 /* If active_path and retran_path are the same and active,
1293 * then this is the only active path. Use it.
1295 if (asoc->peer.active_path == asoc->peer.retran_path &&
1296 asoc->peer.active_path->state == SCTP_ACTIVE)
1299 /* Iterate from retran_path's successor back to retran_path. */
1300 for (trans = list_next_entry(trans, transports); 1;
1301 trans = list_next_entry(trans, transports)) {
1302 /* Manually skip the head element. */
1303 if (&trans->transports == &asoc->peer.transport_addr_list)
1305 if (trans->state == SCTP_UNCONFIRMED)
1307 trans_next = sctp_trans_elect_best(trans, trans_next);
1308 /* Active is good enough for immediate return. */
1309 if (trans_next->state == SCTP_ACTIVE)
1311 /* We've reached the end, time to update path. */
1312 if (trans == asoc->peer.retran_path)
1316 asoc->peer.retran_path = trans_next;
1318 pr_debug("%s: association:%p updated new path to addr:%pISpc\n",
1319 __func__, asoc, &asoc->peer.retran_path->ipaddr.sa);
1322 static void sctp_select_active_and_retran_path(struct sctp_association *asoc)
1324 struct sctp_transport *trans, *trans_pri = NULL, *trans_sec = NULL;
1325 struct sctp_transport *trans_pf = NULL;
1327 /* Look for the two most recently used active transports. */
1328 list_for_each_entry(trans, &asoc->peer.transport_addr_list,
1330 /* Skip uninteresting transports. */
1331 if (trans->state == SCTP_INACTIVE ||
1332 trans->state == SCTP_UNCONFIRMED)
1334 /* Keep track of the best PF transport from our
1335 * list in case we don't find an active one.
1337 if (trans->state == SCTP_PF) {
1338 trans_pf = sctp_trans_elect_best(trans, trans_pf);
1341 /* For active transports, pick the most recent ones. */
1342 if (trans_pri == NULL ||
1343 ktime_after(trans->last_time_heard,
1344 trans_pri->last_time_heard)) {
1345 trans_sec = trans_pri;
1347 } else if (trans_sec == NULL ||
1348 ktime_after(trans->last_time_heard,
1349 trans_sec->last_time_heard)) {
1354 /* RFC 2960 6.4 Multi-Homed SCTP Endpoints
1356 * By default, an endpoint should always transmit to the primary
1357 * path, unless the SCTP user explicitly specifies the
1358 * destination transport address (and possibly source transport
1359 * address) to use. [If the primary is active but not most recent,
1360 * bump the most recently used transport.]
1362 if ((asoc->peer.primary_path->state == SCTP_ACTIVE ||
1363 asoc->peer.primary_path->state == SCTP_UNKNOWN) &&
1364 asoc->peer.primary_path != trans_pri) {
1365 trans_sec = trans_pri;
1366 trans_pri = asoc->peer.primary_path;
1369 /* We did not find anything useful for a possible retransmission
1370 * path; either primary path that we found is the the same as
1371 * the current one, or we didn't generally find an active one.
1373 if (trans_sec == NULL)
1374 trans_sec = trans_pri;
1376 /* If we failed to find a usable transport, just camp on the
1377 * active or pick a PF iff it's the better choice.
1379 if (trans_pri == NULL) {
1380 trans_pri = sctp_trans_elect_best(asoc->peer.active_path, trans_pf);
1381 trans_sec = trans_pri;
1384 /* Set the active and retran transports. */
1385 asoc->peer.active_path = trans_pri;
1386 asoc->peer.retran_path = trans_sec;
1389 struct sctp_transport *
1390 sctp_assoc_choose_alter_transport(struct sctp_association *asoc,
1391 struct sctp_transport *last_sent_to)
1393 /* If this is the first time packet is sent, use the active path,
1394 * else use the retran path. If the last packet was sent over the
1395 * retran path, update the retran path and use it.
1397 if (last_sent_to == NULL) {
1398 return asoc->peer.active_path;
1400 if (last_sent_to == asoc->peer.retran_path)
1401 sctp_assoc_update_retran_path(asoc);
1403 return asoc->peer.retran_path;
1407 /* Update the association's pmtu and frag_point by going through all the
1408 * transports. This routine is called when a transport's PMTU has changed.
1410 void sctp_assoc_sync_pmtu(struct sock *sk, struct sctp_association *asoc)
1412 struct sctp_transport *t;
1418 /* Get the lowest pmtu of all the transports. */
1419 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1421 if (t->pmtu_pending && t->dst) {
1422 sctp_transport_update_pmtu(sk, t,
1423 SCTP_TRUNC4(dst_mtu(t->dst)));
1424 t->pmtu_pending = 0;
1426 if (!pmtu || (t->pathmtu < pmtu))
1431 asoc->pathmtu = pmtu;
1432 asoc->frag_point = sctp_frag_point(asoc, pmtu);
1435 pr_debug("%s: asoc:%p, pmtu:%d, frag_point:%d\n", __func__, asoc,
1436 asoc->pathmtu, asoc->frag_point);
1439 /* Should we send a SACK to update our peer? */
1440 static inline bool sctp_peer_needs_update(struct sctp_association *asoc)
1442 struct net *net = sock_net(asoc->base.sk);
1443 switch (asoc->state) {
1444 case SCTP_STATE_ESTABLISHED:
1445 case SCTP_STATE_SHUTDOWN_PENDING:
1446 case SCTP_STATE_SHUTDOWN_RECEIVED:
1447 case SCTP_STATE_SHUTDOWN_SENT:
1448 if ((asoc->rwnd > asoc->a_rwnd) &&
1449 ((asoc->rwnd - asoc->a_rwnd) >= max_t(__u32,
1450 (asoc->base.sk->sk_rcvbuf >> net->sctp.rwnd_upd_shift),
1460 /* Increase asoc's rwnd by len and send any window update SACK if needed. */
1461 void sctp_assoc_rwnd_increase(struct sctp_association *asoc, unsigned int len)
1463 struct sctp_chunk *sack;
1464 struct timer_list *timer;
1466 if (asoc->rwnd_over) {
1467 if (asoc->rwnd_over >= len) {
1468 asoc->rwnd_over -= len;
1470 asoc->rwnd += (len - asoc->rwnd_over);
1471 asoc->rwnd_over = 0;
1477 /* If we had window pressure, start recovering it
1478 * once our rwnd had reached the accumulated pressure
1479 * threshold. The idea is to recover slowly, but up
1480 * to the initial advertised window.
1482 if (asoc->rwnd_press) {
1483 int change = min(asoc->pathmtu, asoc->rwnd_press);
1484 asoc->rwnd += change;
1485 asoc->rwnd_press -= change;
1488 pr_debug("%s: asoc:%p rwnd increased by %d to (%u, %u) - %u\n",
1489 __func__, asoc, len, asoc->rwnd, asoc->rwnd_over,
1492 /* Send a window update SACK if the rwnd has increased by at least the
1493 * minimum of the association's PMTU and half of the receive buffer.
1494 * The algorithm used is similar to the one described in
1495 * Section 4.2.3.3 of RFC 1122.
1497 if (sctp_peer_needs_update(asoc)) {
1498 asoc->a_rwnd = asoc->rwnd;
1500 pr_debug("%s: sending window update SACK- asoc:%p rwnd:%u "
1501 "a_rwnd:%u\n", __func__, asoc, asoc->rwnd,
1504 sack = sctp_make_sack(asoc);
1508 asoc->peer.sack_needed = 0;
1510 sctp_outq_tail(&asoc->outqueue, sack, GFP_ATOMIC);
1512 /* Stop the SACK timer. */
1513 timer = &asoc->timers[SCTP_EVENT_TIMEOUT_SACK];
1514 if (del_timer(timer))
1515 sctp_association_put(asoc);
1519 /* Decrease asoc's rwnd by len. */
1520 void sctp_assoc_rwnd_decrease(struct sctp_association *asoc, unsigned int len)
1525 if (unlikely(!asoc->rwnd || asoc->rwnd_over))
1526 pr_debug("%s: association:%p has asoc->rwnd:%u, "
1527 "asoc->rwnd_over:%u!\n", __func__, asoc,
1528 asoc->rwnd, asoc->rwnd_over);
1530 if (asoc->ep->rcvbuf_policy)
1531 rx_count = atomic_read(&asoc->rmem_alloc);
1533 rx_count = atomic_read(&asoc->base.sk->sk_rmem_alloc);
1535 /* If we've reached or overflowed our receive buffer, announce
1536 * a 0 rwnd if rwnd would still be positive. Store the
1537 * the potential pressure overflow so that the window can be restored
1538 * back to original value.
1540 if (rx_count >= asoc->base.sk->sk_rcvbuf)
1543 if (asoc->rwnd >= len) {
1546 asoc->rwnd_press += asoc->rwnd;
1550 asoc->rwnd_over += len - asoc->rwnd;
1554 pr_debug("%s: asoc:%p rwnd decreased by %d to (%u, %u, %u)\n",
1555 __func__, asoc, len, asoc->rwnd, asoc->rwnd_over,
1559 /* Build the bind address list for the association based on info from the
1560 * local endpoint and the remote peer.
1562 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
1563 sctp_scope_t scope, gfp_t gfp)
1567 /* Use scoping rules to determine the subset of addresses from
1570 flags = (PF_INET6 == asoc->base.sk->sk_family) ? SCTP_ADDR6_ALLOWED : 0;
1571 if (asoc->peer.ipv4_address)
1572 flags |= SCTP_ADDR4_PEERSUPP;
1573 if (asoc->peer.ipv6_address)
1574 flags |= SCTP_ADDR6_PEERSUPP;
1576 return sctp_bind_addr_copy(sock_net(asoc->base.sk),
1577 &asoc->base.bind_addr,
1578 &asoc->ep->base.bind_addr,
1582 /* Build the association's bind address list from the cookie. */
1583 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *asoc,
1584 struct sctp_cookie *cookie,
1587 int var_size2 = ntohs(cookie->peer_init->chunk_hdr.length);
1588 int var_size3 = cookie->raw_addr_list_len;
1589 __u8 *raw = (__u8 *)cookie->peer_init + var_size2;
1591 return sctp_raw_to_bind_addrs(&asoc->base.bind_addr, raw, var_size3,
1592 asoc->ep->base.bind_addr.port, gfp);
1595 /* Lookup laddr in the bind address list of an association. */
1596 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
1597 const union sctp_addr *laddr)
1601 if ((asoc->base.bind_addr.port == ntohs(laddr->v4.sin_port)) &&
1602 sctp_bind_addr_match(&asoc->base.bind_addr, laddr,
1603 sctp_sk(asoc->base.sk)))
1609 /* Set an association id for a given association */
1610 int sctp_assoc_set_id(struct sctp_association *asoc, gfp_t gfp)
1612 bool preload = gfpflags_allow_blocking(gfp);
1615 /* If the id is already assigned, keep it. */
1621 spin_lock_bh(&sctp_assocs_id_lock);
1622 /* 0 is not a valid assoc_id, must be >= 1 */
1623 ret = idr_alloc_cyclic(&sctp_assocs_id, asoc, 1, 0, GFP_NOWAIT);
1624 spin_unlock_bh(&sctp_assocs_id_lock);
1630 asoc->assoc_id = (sctp_assoc_t)ret;
1634 /* Free the ASCONF queue */
1635 static void sctp_assoc_free_asconf_queue(struct sctp_association *asoc)
1637 struct sctp_chunk *asconf;
1638 struct sctp_chunk *tmp;
1640 list_for_each_entry_safe(asconf, tmp, &asoc->addip_chunk_list, list) {
1641 list_del_init(&asconf->list);
1642 sctp_chunk_free(asconf);
1646 /* Free asconf_ack cache */
1647 static void sctp_assoc_free_asconf_acks(struct sctp_association *asoc)
1649 struct sctp_chunk *ack;
1650 struct sctp_chunk *tmp;
1652 list_for_each_entry_safe(ack, tmp, &asoc->asconf_ack_list,
1654 list_del_init(&ack->transmitted_list);
1655 sctp_chunk_free(ack);
1659 /* Clean up the ASCONF_ACK queue */
1660 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc)
1662 struct sctp_chunk *ack;
1663 struct sctp_chunk *tmp;
1665 /* We can remove all the entries from the queue up to
1666 * the "Peer-Sequence-Number".
1668 list_for_each_entry_safe(ack, tmp, &asoc->asconf_ack_list,
1670 if (ack->subh.addip_hdr->serial ==
1671 htonl(asoc->peer.addip_serial))
1674 list_del_init(&ack->transmitted_list);
1675 sctp_chunk_free(ack);
1679 /* Find the ASCONF_ACK whose serial number matches ASCONF */
1680 struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
1681 const struct sctp_association *asoc,
1684 struct sctp_chunk *ack;
1686 /* Walk through the list of cached ASCONF-ACKs and find the
1687 * ack chunk whose serial number matches that of the request.
1689 list_for_each_entry(ack, &asoc->asconf_ack_list, transmitted_list) {
1690 if (sctp_chunk_pending(ack))
1692 if (ack->subh.addip_hdr->serial == serial) {
1693 sctp_chunk_hold(ack);
1701 void sctp_asconf_queue_teardown(struct sctp_association *asoc)
1703 /* Free any cached ASCONF_ACK chunk. */
1704 sctp_assoc_free_asconf_acks(asoc);
1706 /* Free the ASCONF queue. */
1707 sctp_assoc_free_asconf_queue(asoc);
1709 /* Free any cached ASCONF chunk. */
1710 if (asoc->addip_last_asconf)
1711 sctp_chunk_free(asoc->addip_last_asconf);