1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* SCTP kernel implementation
3 * (C) Copyright IBM Corp. 2001, 2004
4 * Copyright (c) 1999-2000 Cisco, Inc.
5 * Copyright (c) 1999-2001 Motorola, Inc.
6 * Copyright (c) 2001 Intel Corp.
7 * Copyright (c) 2001 La Monte H.P. Yarroll
9 * This file is part of the SCTP kernel implementation
11 * This module provides the abstraction for an SCTP association.
13 * Please send any bug reports or fixes you make to the
15 * lksctp developers <linux-sctp@vger.kernel.org>
17 * Written or modified by:
18 * La Monte H.P. Yarroll <piggy@acm.org>
19 * Karl Knutson <karl@athena.chicago.il.us>
20 * Jon Grimm <jgrimm@us.ibm.com>
21 * Xingang Guo <xingang.guo@intel.com>
22 * Hui Huang <hui.huang@nokia.com>
23 * Sridhar Samudrala <sri@us.ibm.com>
24 * Daisy Chang <daisyc@us.ibm.com>
25 * Ryan Layer <rmlayer@us.ibm.com>
26 * Kevin Gao <kevin.gao@intel.com>
29 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
31 #include <linux/types.h>
32 #include <linux/fcntl.h>
33 #include <linux/poll.h>
34 #include <linux/init.h>
36 #include <linux/slab.h>
39 #include <net/sctp/sctp.h>
40 #include <net/sctp/sm.h>
42 /* Forward declarations for internal functions. */
43 static void sctp_select_active_and_retran_path(struct sctp_association *asoc);
44 static void sctp_assoc_bh_rcv(struct work_struct *work);
45 static void sctp_assoc_free_asconf_acks(struct sctp_association *asoc);
46 static void sctp_assoc_free_asconf_queue(struct sctp_association *asoc);
48 /* 1st Level Abstractions. */
50 /* Initialize a new association from provided memory. */
51 static struct sctp_association *sctp_association_init(
52 struct sctp_association *asoc,
53 const struct sctp_endpoint *ep,
54 const struct sock *sk,
55 enum sctp_scope scope, gfp_t gfp)
57 struct net *net = sock_net(sk);
59 struct sctp_paramhdr *p;
62 /* Retrieve the SCTP per socket area. */
63 sp = sctp_sk((struct sock *)sk);
65 /* Discarding const is appropriate here. */
66 asoc->ep = (struct sctp_endpoint *)ep;
67 asoc->base.sk = (struct sock *)sk;
69 sctp_endpoint_hold(asoc->ep);
70 sock_hold(asoc->base.sk);
72 /* Initialize the common base substructure. */
73 asoc->base.type = SCTP_EP_TYPE_ASSOCIATION;
75 /* Initialize the object handling fields. */
76 refcount_set(&asoc->base.refcnt, 1);
78 /* Initialize the bind addr area. */
79 sctp_bind_addr_init(&asoc->base.bind_addr, ep->base.bind_addr.port);
81 asoc->state = SCTP_STATE_CLOSED;
82 asoc->cookie_life = ms_to_ktime(sp->assocparams.sasoc_cookie_life);
83 asoc->user_frag = sp->user_frag;
85 /* Set the association max_retrans and RTO values from the
88 asoc->max_retrans = sp->assocparams.sasoc_asocmaxrxt;
89 asoc->pf_retrans = sp->pf_retrans;
91 asoc->rto_initial = msecs_to_jiffies(sp->rtoinfo.srto_initial);
92 asoc->rto_max = msecs_to_jiffies(sp->rtoinfo.srto_max);
93 asoc->rto_min = msecs_to_jiffies(sp->rtoinfo.srto_min);
95 /* Initialize the association's heartbeat interval based on the
96 * sock configured value.
98 asoc->hbinterval = msecs_to_jiffies(sp->hbinterval);
100 /* Initialize path max retrans value. */
101 asoc->pathmaxrxt = sp->pathmaxrxt;
103 asoc->flowlabel = sp->flowlabel;
104 asoc->dscp = sp->dscp;
106 /* Set association default SACK delay */
107 asoc->sackdelay = msecs_to_jiffies(sp->sackdelay);
108 asoc->sackfreq = sp->sackfreq;
110 /* Set the association default flags controlling
111 * Heartbeat, SACK delay, and Path MTU Discovery.
113 asoc->param_flags = sp->param_flags;
115 /* Initialize the maximum number of new data packets that can be sent
118 asoc->max_burst = sp->max_burst;
120 asoc->subscribe = sp->subscribe;
122 /* initialize association timers */
123 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] = asoc->rto_initial;
124 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] = asoc->rto_initial;
125 asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = asoc->rto_initial;
127 /* sctpimpguide Section 2.12.2
128 * If the 'T5-shutdown-guard' timer is used, it SHOULD be set to the
129 * recommended value of 5 times 'RTO.Max'.
131 asoc->timeouts[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD]
134 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] = asoc->sackdelay;
135 asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE] = sp->autoclose * HZ;
137 /* Initializes the timers */
138 for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i)
139 timer_setup(&asoc->timers[i], sctp_timer_events[i], 0);
141 /* Pull default initialization values from the sock options.
142 * Note: This assumes that the values have already been
143 * validated in the sock.
145 asoc->c.sinit_max_instreams = sp->initmsg.sinit_max_instreams;
146 asoc->c.sinit_num_ostreams = sp->initmsg.sinit_num_ostreams;
147 asoc->max_init_attempts = sp->initmsg.sinit_max_attempts;
149 asoc->max_init_timeo =
150 msecs_to_jiffies(sp->initmsg.sinit_max_init_timeo);
152 /* Set the local window size for receive.
153 * This is also the rcvbuf space per association.
154 * RFC 6 - A SCTP receiver MUST be able to receive a minimum of
155 * 1500 bytes in one SCTP packet.
157 if ((sk->sk_rcvbuf/2) < SCTP_DEFAULT_MINWINDOW)
158 asoc->rwnd = SCTP_DEFAULT_MINWINDOW;
160 asoc->rwnd = sk->sk_rcvbuf/2;
162 asoc->a_rwnd = asoc->rwnd;
164 /* Use my own max window until I learn something better. */
165 asoc->peer.rwnd = SCTP_DEFAULT_MAXWINDOW;
167 /* Initialize the receive memory counter */
168 atomic_set(&asoc->rmem_alloc, 0);
170 init_waitqueue_head(&asoc->wait);
172 asoc->c.my_vtag = sctp_generate_tag(ep);
173 asoc->c.my_port = ep->base.bind_addr.port;
175 asoc->c.initial_tsn = sctp_generate_tsn(ep);
177 asoc->next_tsn = asoc->c.initial_tsn;
179 asoc->ctsn_ack_point = asoc->next_tsn - 1;
180 asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
181 asoc->highest_sacked = asoc->ctsn_ack_point;
182 asoc->last_cwr_tsn = asoc->ctsn_ack_point;
184 /* ADDIP Section 4.1 Asconf Chunk Procedures
186 * When an endpoint has an ASCONF signaled change to be sent to the
187 * remote endpoint it should do the following:
189 * A2) a serial number should be assigned to the chunk. The serial
190 * number SHOULD be a monotonically increasing number. The serial
191 * numbers SHOULD be initialized at the start of the
192 * association to the same value as the initial TSN.
194 asoc->addip_serial = asoc->c.initial_tsn;
195 asoc->strreset_outseq = asoc->c.initial_tsn;
197 INIT_LIST_HEAD(&asoc->addip_chunk_list);
198 INIT_LIST_HEAD(&asoc->asconf_ack_list);
200 /* Make an empty list of remote transport addresses. */
201 INIT_LIST_HEAD(&asoc->peer.transport_addr_list);
203 /* RFC 2960 5.1 Normal Establishment of an Association
205 * After the reception of the first data chunk in an
206 * association the endpoint must immediately respond with a
207 * sack to acknowledge the data chunk. Subsequent
208 * acknowledgements should be done as described in Section
211 * [We implement this by telling a new association that it
212 * already received one packet.]
214 asoc->peer.sack_needed = 1;
215 asoc->peer.sack_generation = 1;
217 /* Assume that the peer will tell us if he recognizes ASCONF
218 * as part of INIT exchange.
219 * The sctp_addip_noauth option is there for backward compatibility
220 * and will revert old behavior.
222 if (net->sctp.addip_noauth)
223 asoc->peer.asconf_capable = 1;
225 /* Create an input queue. */
226 sctp_inq_init(&asoc->base.inqueue);
227 sctp_inq_set_th_handler(&asoc->base.inqueue, sctp_assoc_bh_rcv);
229 /* Create an output queue. */
230 sctp_outq_init(asoc, &asoc->outqueue);
232 if (!sctp_ulpq_init(&asoc->ulpq, asoc))
235 if (sctp_stream_init(&asoc->stream, asoc->c.sinit_num_ostreams,
239 /* Initialize default path MTU. */
240 asoc->pathmtu = sp->pathmtu;
241 sctp_assoc_update_frag_point(asoc);
243 /* Assume that peer would support both address types unless we are
246 asoc->peer.ipv4_address = 1;
247 if (asoc->base.sk->sk_family == PF_INET6)
248 asoc->peer.ipv6_address = 1;
249 INIT_LIST_HEAD(&asoc->asocs);
251 asoc->default_stream = sp->default_stream;
252 asoc->default_ppid = sp->default_ppid;
253 asoc->default_flags = sp->default_flags;
254 asoc->default_context = sp->default_context;
255 asoc->default_timetolive = sp->default_timetolive;
256 asoc->default_rcv_context = sp->default_rcv_context;
258 /* AUTH related initializations */
259 INIT_LIST_HEAD(&asoc->endpoint_shared_keys);
260 if (sctp_auth_asoc_copy_shkeys(ep, asoc, gfp))
263 asoc->active_key_id = ep->active_key_id;
264 asoc->strreset_enable = ep->strreset_enable;
266 /* Save the hmacs and chunks list into this association */
267 if (ep->auth_hmacs_list)
268 memcpy(asoc->c.auth_hmacs, ep->auth_hmacs_list,
269 ntohs(ep->auth_hmacs_list->param_hdr.length));
270 if (ep->auth_chunk_list)
271 memcpy(asoc->c.auth_chunks, ep->auth_chunk_list,
272 ntohs(ep->auth_chunk_list->param_hdr.length));
274 /* Get the AUTH random number for this association */
275 p = (struct sctp_paramhdr *)asoc->c.auth_random;
276 p->type = SCTP_PARAM_RANDOM;
277 p->length = htons(sizeof(*p) + SCTP_AUTH_RANDOM_LENGTH);
278 get_random_bytes(p+1, SCTP_AUTH_RANDOM_LENGTH);
283 sctp_stream_free(&asoc->stream);
285 sock_put(asoc->base.sk);
286 sctp_endpoint_put(asoc->ep);
290 /* Allocate and initialize a new association */
291 struct sctp_association *sctp_association_new(const struct sctp_endpoint *ep,
292 const struct sock *sk,
293 enum sctp_scope scope, gfp_t gfp)
295 struct sctp_association *asoc;
297 asoc = kzalloc(sizeof(*asoc), gfp);
301 if (!sctp_association_init(asoc, ep, sk, scope, gfp))
304 SCTP_DBG_OBJCNT_INC(assoc);
306 pr_debug("Created asoc %p\n", asoc);
316 /* Free this association if possible. There may still be users, so
317 * the actual deallocation may be delayed.
319 void sctp_association_free(struct sctp_association *asoc)
321 struct sock *sk = asoc->base.sk;
322 struct sctp_transport *transport;
323 struct list_head *pos, *temp;
326 /* Only real associations count against the endpoint, so
327 * don't bother for if this is a temporary association.
329 if (!list_empty(&asoc->asocs)) {
330 list_del(&asoc->asocs);
332 /* Decrement the backlog value for a TCP-style listening
335 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
336 sk->sk_ack_backlog--;
339 /* Mark as dead, so other users can know this structure is
342 asoc->base.dead = true;
344 /* Dispose of any data lying around in the outqueue. */
345 sctp_outq_free(&asoc->outqueue);
347 /* Dispose of any pending messages for the upper layer. */
348 sctp_ulpq_free(&asoc->ulpq);
350 /* Dispose of any pending chunks on the inqueue. */
351 sctp_inq_free(&asoc->base.inqueue);
353 sctp_tsnmap_free(&asoc->peer.tsn_map);
355 /* Free stream information. */
356 sctp_stream_free(&asoc->stream);
358 if (asoc->strreset_chunk)
359 sctp_chunk_free(asoc->strreset_chunk);
361 /* Clean up the bound address list. */
362 sctp_bind_addr_free(&asoc->base.bind_addr);
364 /* Do we need to go through all of our timers and
365 * delete them? To be safe we will try to delete all, but we
366 * should be able to go through and make a guess based
369 for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i) {
370 if (del_timer(&asoc->timers[i]))
371 sctp_association_put(asoc);
374 /* Free peer's cached cookie. */
375 kfree(asoc->peer.cookie);
376 kfree(asoc->peer.peer_random);
377 kfree(asoc->peer.peer_chunks);
378 kfree(asoc->peer.peer_hmacs);
380 /* Release the transport structures. */
381 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
382 transport = list_entry(pos, struct sctp_transport, transports);
384 sctp_unhash_transport(transport);
385 sctp_transport_free(transport);
388 asoc->peer.transport_count = 0;
390 sctp_asconf_queue_teardown(asoc);
392 /* Free pending address space being deleted */
393 kfree(asoc->asconf_addr_del_pending);
395 /* AUTH - Free the endpoint shared keys */
396 sctp_auth_destroy_keys(&asoc->endpoint_shared_keys);
398 /* AUTH - Free the association shared key */
399 sctp_auth_key_put(asoc->asoc_shared_key);
401 sctp_association_put(asoc);
404 /* Cleanup and free up an association. */
405 static void sctp_association_destroy(struct sctp_association *asoc)
407 if (unlikely(!asoc->base.dead)) {
408 WARN(1, "Attempt to destroy undead association %p!\n", asoc);
412 sctp_endpoint_put(asoc->ep);
413 sock_put(asoc->base.sk);
415 if (asoc->assoc_id != 0) {
416 spin_lock_bh(&sctp_assocs_id_lock);
417 idr_remove(&sctp_assocs_id, asoc->assoc_id);
418 spin_unlock_bh(&sctp_assocs_id_lock);
421 WARN_ON(atomic_read(&asoc->rmem_alloc));
423 kfree_rcu(asoc, rcu);
424 SCTP_DBG_OBJCNT_DEC(assoc);
427 /* Change the primary destination address for the peer. */
428 void sctp_assoc_set_primary(struct sctp_association *asoc,
429 struct sctp_transport *transport)
433 /* it's a changeover only if we already have a primary path
434 * that we are changing
436 if (asoc->peer.primary_path != NULL &&
437 asoc->peer.primary_path != transport)
440 asoc->peer.primary_path = transport;
442 /* Set a default msg_name for events. */
443 memcpy(&asoc->peer.primary_addr, &transport->ipaddr,
444 sizeof(union sctp_addr));
446 /* If the primary path is changing, assume that the
447 * user wants to use this new path.
449 if ((transport->state == SCTP_ACTIVE) ||
450 (transport->state == SCTP_UNKNOWN))
451 asoc->peer.active_path = transport;
454 * SFR-CACC algorithm:
455 * Upon the receipt of a request to change the primary
456 * destination address, on the data structure for the new
457 * primary destination, the sender MUST do the following:
459 * 1) If CHANGEOVER_ACTIVE is set, then there was a switch
460 * to this destination address earlier. The sender MUST set
461 * CYCLING_CHANGEOVER to indicate that this switch is a
462 * double switch to the same destination address.
464 * Really, only bother is we have data queued or outstanding on
467 if (!asoc->outqueue.outstanding_bytes && !asoc->outqueue.out_qlen)
470 if (transport->cacc.changeover_active)
471 transport->cacc.cycling_changeover = changeover;
473 /* 2) The sender MUST set CHANGEOVER_ACTIVE to indicate that
474 * a changeover has occurred.
476 transport->cacc.changeover_active = changeover;
478 /* 3) The sender MUST store the next TSN to be sent in
479 * next_tsn_at_change.
481 transport->cacc.next_tsn_at_change = asoc->next_tsn;
484 /* Remove a transport from an association. */
485 void sctp_assoc_rm_peer(struct sctp_association *asoc,
486 struct sctp_transport *peer)
488 struct sctp_transport *transport;
489 struct list_head *pos;
490 struct sctp_chunk *ch;
492 pr_debug("%s: association:%p addr:%pISpc\n",
493 __func__, asoc, &peer->ipaddr.sa);
495 /* If we are to remove the current retran_path, update it
496 * to the next peer before removing this peer from the list.
498 if (asoc->peer.retran_path == peer)
499 sctp_assoc_update_retran_path(asoc);
501 /* Remove this peer from the list. */
502 list_del_rcu(&peer->transports);
503 /* Remove this peer from the transport hashtable */
504 sctp_unhash_transport(peer);
506 /* Get the first transport of asoc. */
507 pos = asoc->peer.transport_addr_list.next;
508 transport = list_entry(pos, struct sctp_transport, transports);
510 /* Update any entries that match the peer to be deleted. */
511 if (asoc->peer.primary_path == peer)
512 sctp_assoc_set_primary(asoc, transport);
513 if (asoc->peer.active_path == peer)
514 asoc->peer.active_path = transport;
515 if (asoc->peer.retran_path == peer)
516 asoc->peer.retran_path = transport;
517 if (asoc->peer.last_data_from == peer)
518 asoc->peer.last_data_from = transport;
520 if (asoc->strreset_chunk &&
521 asoc->strreset_chunk->transport == peer) {
522 asoc->strreset_chunk->transport = transport;
523 sctp_transport_reset_reconf_timer(transport);
526 /* If we remove the transport an INIT was last sent to, set it to
527 * NULL. Combined with the update of the retran path above, this
528 * will cause the next INIT to be sent to the next available
529 * transport, maintaining the cycle.
531 if (asoc->init_last_sent_to == peer)
532 asoc->init_last_sent_to = NULL;
534 /* If we remove the transport an SHUTDOWN was last sent to, set it
535 * to NULL. Combined with the update of the retran path above, this
536 * will cause the next SHUTDOWN to be sent to the next available
537 * transport, maintaining the cycle.
539 if (asoc->shutdown_last_sent_to == peer)
540 asoc->shutdown_last_sent_to = NULL;
542 /* If we remove the transport an ASCONF was last sent to, set it to
545 if (asoc->addip_last_asconf &&
546 asoc->addip_last_asconf->transport == peer)
547 asoc->addip_last_asconf->transport = NULL;
549 /* If we have something on the transmitted list, we have to
550 * save it off. The best place is the active path.
552 if (!list_empty(&peer->transmitted)) {
553 struct sctp_transport *active = asoc->peer.active_path;
555 /* Reset the transport of each chunk on this list */
556 list_for_each_entry(ch, &peer->transmitted,
558 ch->transport = NULL;
559 ch->rtt_in_progress = 0;
562 list_splice_tail_init(&peer->transmitted,
563 &active->transmitted);
565 /* Start a T3 timer here in case it wasn't running so
566 * that these migrated packets have a chance to get
569 if (!timer_pending(&active->T3_rtx_timer))
570 if (!mod_timer(&active->T3_rtx_timer,
571 jiffies + active->rto))
572 sctp_transport_hold(active);
575 list_for_each_entry(ch, &asoc->outqueue.out_chunk_list, list)
576 if (ch->transport == peer)
577 ch->transport = NULL;
579 asoc->peer.transport_count--;
581 sctp_transport_free(peer);
584 /* Add a transport address to an association. */
585 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc,
586 const union sctp_addr *addr,
588 const int peer_state)
590 struct net *net = sock_net(asoc->base.sk);
591 struct sctp_transport *peer;
592 struct sctp_sock *sp;
595 sp = sctp_sk(asoc->base.sk);
597 /* AF_INET and AF_INET6 share common port field. */
598 port = ntohs(addr->v4.sin_port);
600 pr_debug("%s: association:%p addr:%pISpc state:%d\n", __func__,
601 asoc, &addr->sa, peer_state);
603 /* Set the port if it has not been set yet. */
604 if (0 == asoc->peer.port)
605 asoc->peer.port = port;
607 /* Check to see if this is a duplicate. */
608 peer = sctp_assoc_lookup_paddr(asoc, addr);
610 /* An UNKNOWN state is only set on transports added by
611 * user in sctp_connectx() call. Such transports should be
612 * considered CONFIRMED per RFC 4960, Section 5.4.
614 if (peer->state == SCTP_UNKNOWN) {
615 peer->state = SCTP_ACTIVE;
620 peer = sctp_transport_new(net, addr, gfp);
624 sctp_transport_set_owner(peer, asoc);
626 /* Initialize the peer's heartbeat interval based on the
627 * association configured value.
629 peer->hbinterval = asoc->hbinterval;
631 /* Set the path max_retrans. */
632 peer->pathmaxrxt = asoc->pathmaxrxt;
634 /* And the partial failure retrans threshold */
635 peer->pf_retrans = asoc->pf_retrans;
637 /* Initialize the peer's SACK delay timeout based on the
638 * association configured value.
640 peer->sackdelay = asoc->sackdelay;
641 peer->sackfreq = asoc->sackfreq;
643 if (addr->sa.sa_family == AF_INET6) {
644 __be32 info = addr->v6.sin6_flowinfo;
647 peer->flowlabel = ntohl(info & IPV6_FLOWLABEL_MASK);
648 peer->flowlabel |= SCTP_FLOWLABEL_SET_MASK;
650 peer->flowlabel = asoc->flowlabel;
653 peer->dscp = asoc->dscp;
655 /* Enable/disable heartbeat, SACK delay, and path MTU discovery
656 * based on association setting.
658 peer->param_flags = asoc->param_flags;
660 /* Initialize the pmtu of the transport. */
661 sctp_transport_route(peer, NULL, sp);
663 /* If this is the first transport addr on this association,
664 * initialize the association PMTU to the peer's PMTU.
665 * If not and the current association PMTU is higher than the new
666 * peer's PMTU, reset the association PMTU to the new peer's PMTU.
668 sctp_assoc_set_pmtu(asoc, asoc->pathmtu ?
669 min_t(int, peer->pathmtu, asoc->pathmtu) :
672 peer->pmtu_pending = 0;
674 /* The asoc->peer.port might not be meaningful yet, but
675 * initialize the packet structure anyway.
677 sctp_packet_init(&peer->packet, peer, asoc->base.bind_addr.port,
682 * o The initial cwnd before DATA transmission or after a sufficiently
683 * long idle period MUST be set to
684 * min(4*MTU, max(2*MTU, 4380 bytes))
686 * o The initial value of ssthresh MAY be arbitrarily high
687 * (for example, implementations MAY use the size of the
688 * receiver advertised window).
690 peer->cwnd = min(4*asoc->pathmtu, max_t(__u32, 2*asoc->pathmtu, 4380));
692 /* At this point, we may not have the receiver's advertised window,
693 * so initialize ssthresh to the default value and it will be set
694 * later when we process the INIT.
696 peer->ssthresh = SCTP_DEFAULT_MAXWINDOW;
698 peer->partial_bytes_acked = 0;
699 peer->flight_size = 0;
700 peer->burst_limited = 0;
702 /* Set the transport's RTO.initial value */
703 peer->rto = asoc->rto_initial;
704 sctp_max_rto(asoc, peer);
706 /* Set the peer's active state. */
707 peer->state = peer_state;
709 /* Add this peer into the transport hashtable */
710 if (sctp_hash_transport(peer)) {
711 sctp_transport_free(peer);
715 /* Attach the remote transport to our asoc. */
716 list_add_tail_rcu(&peer->transports, &asoc->peer.transport_addr_list);
717 asoc->peer.transport_count++;
719 /* If we do not yet have a primary path, set one. */
720 if (!asoc->peer.primary_path) {
721 sctp_assoc_set_primary(asoc, peer);
722 asoc->peer.retran_path = peer;
725 if (asoc->peer.active_path == asoc->peer.retran_path &&
726 peer->state != SCTP_UNCONFIRMED) {
727 asoc->peer.retran_path = peer;
733 /* Delete a transport address from an association. */
734 void sctp_assoc_del_peer(struct sctp_association *asoc,
735 const union sctp_addr *addr)
737 struct list_head *pos;
738 struct list_head *temp;
739 struct sctp_transport *transport;
741 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
742 transport = list_entry(pos, struct sctp_transport, transports);
743 if (sctp_cmp_addr_exact(addr, &transport->ipaddr)) {
744 /* Do book keeping for removing the peer and free it. */
745 sctp_assoc_rm_peer(asoc, transport);
751 /* Lookup a transport by address. */
752 struct sctp_transport *sctp_assoc_lookup_paddr(
753 const struct sctp_association *asoc,
754 const union sctp_addr *address)
756 struct sctp_transport *t;
758 /* Cycle through all transports searching for a peer address. */
760 list_for_each_entry(t, &asoc->peer.transport_addr_list,
762 if (sctp_cmp_addr_exact(address, &t->ipaddr))
769 /* Remove all transports except a give one */
770 void sctp_assoc_del_nonprimary_peers(struct sctp_association *asoc,
771 struct sctp_transport *primary)
773 struct sctp_transport *temp;
774 struct sctp_transport *t;
776 list_for_each_entry_safe(t, temp, &asoc->peer.transport_addr_list,
778 /* if the current transport is not the primary one, delete it */
780 sctp_assoc_rm_peer(asoc, t);
784 /* Engage in transport control operations.
785 * Mark the transport up or down and send a notification to the user.
786 * Select and update the new active and retran paths.
788 void sctp_assoc_control_transport(struct sctp_association *asoc,
789 struct sctp_transport *transport,
790 enum sctp_transport_cmd command,
791 sctp_sn_error_t error)
793 struct sctp_ulpevent *event;
794 struct sockaddr_storage addr;
796 bool ulp_notify = true;
798 /* Record the transition on the transport. */
800 case SCTP_TRANSPORT_UP:
801 /* If we are moving from UNCONFIRMED state due
802 * to heartbeat success, report the SCTP_ADDR_CONFIRMED
803 * state to the user, otherwise report SCTP_ADDR_AVAILABLE.
805 if (SCTP_UNCONFIRMED == transport->state &&
806 SCTP_HEARTBEAT_SUCCESS == error)
807 spc_state = SCTP_ADDR_CONFIRMED;
809 spc_state = SCTP_ADDR_AVAILABLE;
810 /* Don't inform ULP about transition from PF to
811 * active state and set cwnd to 1 MTU, see SCTP
812 * Quick failover draft section 5.1, point 5
814 if (transport->state == SCTP_PF) {
816 transport->cwnd = asoc->pathmtu;
818 transport->state = SCTP_ACTIVE;
821 case SCTP_TRANSPORT_DOWN:
822 /* If the transport was never confirmed, do not transition it
823 * to inactive state. Also, release the cached route since
824 * there may be a better route next time.
826 if (transport->state != SCTP_UNCONFIRMED)
827 transport->state = SCTP_INACTIVE;
829 sctp_transport_dst_release(transport);
833 spc_state = SCTP_ADDR_UNREACHABLE;
836 case SCTP_TRANSPORT_PF:
837 transport->state = SCTP_PF;
845 /* Generate and send a SCTP_PEER_ADDR_CHANGE notification
849 memset(&addr, 0, sizeof(struct sockaddr_storage));
850 memcpy(&addr, &transport->ipaddr,
851 transport->af_specific->sockaddr_len);
853 event = sctp_ulpevent_make_peer_addr_change(asoc, &addr,
854 0, spc_state, error, GFP_ATOMIC);
856 asoc->stream.si->enqueue_event(&asoc->ulpq, event);
859 /* Select new active and retran paths. */
860 sctp_select_active_and_retran_path(asoc);
863 /* Hold a reference to an association. */
864 void sctp_association_hold(struct sctp_association *asoc)
866 refcount_inc(&asoc->base.refcnt);
869 /* Release a reference to an association and cleanup
870 * if there are no more references.
872 void sctp_association_put(struct sctp_association *asoc)
874 if (refcount_dec_and_test(&asoc->base.refcnt))
875 sctp_association_destroy(asoc);
878 /* Allocate the next TSN, Transmission Sequence Number, for the given
881 __u32 sctp_association_get_next_tsn(struct sctp_association *asoc)
883 /* From Section 1.6 Serial Number Arithmetic:
884 * Transmission Sequence Numbers wrap around when they reach
885 * 2**32 - 1. That is, the next TSN a DATA chunk MUST use
886 * after transmitting TSN = 2*32 - 1 is TSN = 0.
888 __u32 retval = asoc->next_tsn;
895 /* Compare two addresses to see if they match. Wildcard addresses
896 * only match themselves.
898 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
899 const union sctp_addr *ss2)
903 af = sctp_get_af_specific(ss1->sa.sa_family);
907 return af->cmp_addr(ss1, ss2);
910 /* Return an ecne chunk to get prepended to a packet.
911 * Note: We are sly and return a shared, prealloced chunk. FIXME:
912 * No we don't, but we could/should.
914 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc)
916 if (!asoc->need_ecne)
919 /* Send ECNE if needed.
920 * Not being able to allocate a chunk here is not deadly.
922 return sctp_make_ecne(asoc, asoc->last_ecne_tsn);
926 * Find which transport this TSN was sent on.
928 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *asoc,
931 struct sctp_transport *active;
932 struct sctp_transport *match;
933 struct sctp_transport *transport;
934 struct sctp_chunk *chunk;
935 __be32 key = htonl(tsn);
940 * FIXME: In general, find a more efficient data structure for
945 * The general strategy is to search each transport's transmitted
946 * list. Return which transport this TSN lives on.
948 * Let's be hopeful and check the active_path first.
949 * Another optimization would be to know if there is only one
950 * outbound path and not have to look for the TSN at all.
954 active = asoc->peer.active_path;
956 list_for_each_entry(chunk, &active->transmitted,
959 if (key == chunk->subh.data_hdr->tsn) {
965 /* If not found, go search all the other transports. */
966 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
969 if (transport == active)
971 list_for_each_entry(chunk, &transport->transmitted,
973 if (key == chunk->subh.data_hdr->tsn) {
983 /* Do delayed input processing. This is scheduled by sctp_rcv(). */
984 static void sctp_assoc_bh_rcv(struct work_struct *work)
986 struct sctp_association *asoc =
987 container_of(work, struct sctp_association,
988 base.inqueue.immediate);
989 struct net *net = sock_net(asoc->base.sk);
990 union sctp_subtype subtype;
991 struct sctp_endpoint *ep;
992 struct sctp_chunk *chunk;
993 struct sctp_inq *inqueue;
994 int first_time = 1; /* is this the first time through the loop */
998 /* The association should be held so we should be safe. */
1001 inqueue = &asoc->base.inqueue;
1002 sctp_association_hold(asoc);
1003 while (NULL != (chunk = sctp_inq_pop(inqueue))) {
1004 state = asoc->state;
1005 subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type);
1007 /* If the first chunk in the packet is AUTH, do special
1008 * processing specified in Section 6.3 of SCTP-AUTH spec
1010 if (first_time && subtype.chunk == SCTP_CID_AUTH) {
1011 struct sctp_chunkhdr *next_hdr;
1013 next_hdr = sctp_inq_peek(inqueue);
1017 /* If the next chunk is COOKIE-ECHO, skip the AUTH
1018 * chunk while saving a pointer to it so we can do
1019 * Authentication later (during cookie-echo
1022 if (next_hdr->type == SCTP_CID_COOKIE_ECHO) {
1023 chunk->auth_chunk = skb_clone(chunk->skb,
1031 /* SCTP-AUTH, Section 6.3:
1032 * The receiver has a list of chunk types which it expects
1033 * to be received only after an AUTH-chunk. This list has
1034 * been sent to the peer during the association setup. It
1035 * MUST silently discard these chunks if they are not placed
1036 * after an AUTH chunk in the packet.
1038 if (sctp_auth_recv_cid(subtype.chunk, asoc) && !chunk->auth)
1041 /* Remember where the last DATA chunk came from so we
1042 * know where to send the SACK.
1044 if (sctp_chunk_is_data(chunk))
1045 asoc->peer.last_data_from = chunk->transport;
1047 SCTP_INC_STATS(net, SCTP_MIB_INCTRLCHUNKS);
1048 asoc->stats.ictrlchunks++;
1049 if (chunk->chunk_hdr->type == SCTP_CID_SACK)
1050 asoc->stats.isacks++;
1053 if (chunk->transport)
1054 chunk->transport->last_time_heard = ktime_get();
1056 /* Run through the state machine. */
1057 error = sctp_do_sm(net, SCTP_EVENT_T_CHUNK, subtype,
1058 state, ep, asoc, chunk, GFP_ATOMIC);
1060 /* Check to see if the association is freed in response to
1061 * the incoming chunk. If so, get out of the while loop.
1063 if (asoc->base.dead)
1066 /* If there is an error on chunk, discard this packet. */
1068 chunk->pdiscard = 1;
1073 sctp_association_put(asoc);
1076 /* This routine moves an association from its old sk to a new sk. */
1077 void sctp_assoc_migrate(struct sctp_association *assoc, struct sock *newsk)
1079 struct sctp_sock *newsp = sctp_sk(newsk);
1080 struct sock *oldsk = assoc->base.sk;
1082 /* Delete the association from the old endpoint's list of
1085 list_del_init(&assoc->asocs);
1087 /* Decrement the backlog value for a TCP-style socket. */
1088 if (sctp_style(oldsk, TCP))
1089 oldsk->sk_ack_backlog--;
1091 /* Release references to the old endpoint and the sock. */
1092 sctp_endpoint_put(assoc->ep);
1093 sock_put(assoc->base.sk);
1095 /* Get a reference to the new endpoint. */
1096 assoc->ep = newsp->ep;
1097 sctp_endpoint_hold(assoc->ep);
1099 /* Get a reference to the new sock. */
1100 assoc->base.sk = newsk;
1101 sock_hold(assoc->base.sk);
1103 /* Add the association to the new endpoint's list of associations. */
1104 sctp_endpoint_add_asoc(newsp->ep, assoc);
1107 /* Update an association (possibly from unexpected COOKIE-ECHO processing). */
1108 int sctp_assoc_update(struct sctp_association *asoc,
1109 struct sctp_association *new)
1111 struct sctp_transport *trans;
1112 struct list_head *pos, *temp;
1114 /* Copy in new parameters of peer. */
1116 asoc->peer.rwnd = new->peer.rwnd;
1117 asoc->peer.sack_needed = new->peer.sack_needed;
1118 asoc->peer.auth_capable = new->peer.auth_capable;
1119 asoc->peer.i = new->peer.i;
1121 if (!sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
1122 asoc->peer.i.initial_tsn, GFP_ATOMIC))
1125 /* Remove any peer addresses not present in the new association. */
1126 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
1127 trans = list_entry(pos, struct sctp_transport, transports);
1128 if (!sctp_assoc_lookup_paddr(new, &trans->ipaddr)) {
1129 sctp_assoc_rm_peer(asoc, trans);
1133 if (asoc->state >= SCTP_STATE_ESTABLISHED)
1134 sctp_transport_reset(trans);
1137 /* If the case is A (association restart), use
1138 * initial_tsn as next_tsn. If the case is B, use
1139 * current next_tsn in case data sent to peer
1140 * has been discarded and needs retransmission.
1142 if (asoc->state >= SCTP_STATE_ESTABLISHED) {
1143 asoc->next_tsn = new->next_tsn;
1144 asoc->ctsn_ack_point = new->ctsn_ack_point;
1145 asoc->adv_peer_ack_point = new->adv_peer_ack_point;
1147 /* Reinitialize SSN for both local streams
1148 * and peer's streams.
1150 sctp_stream_clear(&asoc->stream);
1152 /* Flush the ULP reassembly and ordered queue.
1153 * Any data there will now be stale and will
1156 sctp_ulpq_flush(&asoc->ulpq);
1158 /* reset the overall association error count so
1159 * that the restarted association doesn't get torn
1160 * down on the next retransmission timer.
1162 asoc->overall_error_count = 0;
1165 /* Add any peer addresses from the new association. */
1166 list_for_each_entry(trans, &new->peer.transport_addr_list,
1168 if (!sctp_assoc_lookup_paddr(asoc, &trans->ipaddr) &&
1169 !sctp_assoc_add_peer(asoc, &trans->ipaddr,
1170 GFP_ATOMIC, trans->state))
1173 asoc->ctsn_ack_point = asoc->next_tsn - 1;
1174 asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
1176 if (sctp_state(asoc, COOKIE_WAIT))
1177 sctp_stream_update(&asoc->stream, &new->stream);
1179 /* get a new assoc id if we don't have one yet. */
1180 if (sctp_assoc_set_id(asoc, GFP_ATOMIC))
1184 /* SCTP-AUTH: Save the peer parameters from the new associations
1185 * and also move the association shared keys over
1187 kfree(asoc->peer.peer_random);
1188 asoc->peer.peer_random = new->peer.peer_random;
1189 new->peer.peer_random = NULL;
1191 kfree(asoc->peer.peer_chunks);
1192 asoc->peer.peer_chunks = new->peer.peer_chunks;
1193 new->peer.peer_chunks = NULL;
1195 kfree(asoc->peer.peer_hmacs);
1196 asoc->peer.peer_hmacs = new->peer.peer_hmacs;
1197 new->peer.peer_hmacs = NULL;
1199 return sctp_auth_asoc_init_active_key(asoc, GFP_ATOMIC);
1202 /* Update the retran path for sending a retransmitted packet.
1203 * See also RFC4960, 6.4. Multi-Homed SCTP Endpoints:
1205 * When there is outbound data to send and the primary path
1206 * becomes inactive (e.g., due to failures), or where the
1207 * SCTP user explicitly requests to send data to an
1208 * inactive destination transport address, before reporting
1209 * an error to its ULP, the SCTP endpoint should try to send
1210 * the data to an alternate active destination transport
1211 * address if one exists.
1213 * When retransmitting data that timed out, if the endpoint
1214 * is multihomed, it should consider each source-destination
1215 * address pair in its retransmission selection policy.
1216 * When retransmitting timed-out data, the endpoint should
1217 * attempt to pick the most divergent source-destination
1218 * pair from the original source-destination pair to which
1219 * the packet was transmitted.
1221 * Note: Rules for picking the most divergent source-destination
1222 * pair are an implementation decision and are not specified
1223 * within this document.
1225 * Our basic strategy is to round-robin transports in priorities
1226 * according to sctp_trans_score() e.g., if no such
1227 * transport with state SCTP_ACTIVE exists, round-robin through
1228 * SCTP_UNKNOWN, etc. You get the picture.
1230 static u8 sctp_trans_score(const struct sctp_transport *trans)
1232 switch (trans->state) {
1234 return 3; /* best case */
1239 default: /* case SCTP_INACTIVE */
1240 return 0; /* worst case */
1244 static struct sctp_transport *sctp_trans_elect_tie(struct sctp_transport *trans1,
1245 struct sctp_transport *trans2)
1247 if (trans1->error_count > trans2->error_count) {
1249 } else if (trans1->error_count == trans2->error_count &&
1250 ktime_after(trans2->last_time_heard,
1251 trans1->last_time_heard)) {
1258 static struct sctp_transport *sctp_trans_elect_best(struct sctp_transport *curr,
1259 struct sctp_transport *best)
1261 u8 score_curr, score_best;
1263 if (best == NULL || curr == best)
1266 score_curr = sctp_trans_score(curr);
1267 score_best = sctp_trans_score(best);
1269 /* First, try a score-based selection if both transport states
1270 * differ. If we're in a tie, lets try to make a more clever
1271 * decision here based on error counts and last time heard.
1273 if (score_curr > score_best)
1275 else if (score_curr == score_best)
1276 return sctp_trans_elect_tie(best, curr);
1281 void sctp_assoc_update_retran_path(struct sctp_association *asoc)
1283 struct sctp_transport *trans = asoc->peer.retran_path;
1284 struct sctp_transport *trans_next = NULL;
1286 /* We're done as we only have the one and only path. */
1287 if (asoc->peer.transport_count == 1)
1289 /* If active_path and retran_path are the same and active,
1290 * then this is the only active path. Use it.
1292 if (asoc->peer.active_path == asoc->peer.retran_path &&
1293 asoc->peer.active_path->state == SCTP_ACTIVE)
1296 /* Iterate from retran_path's successor back to retran_path. */
1297 for (trans = list_next_entry(trans, transports); 1;
1298 trans = list_next_entry(trans, transports)) {
1299 /* Manually skip the head element. */
1300 if (&trans->transports == &asoc->peer.transport_addr_list)
1302 if (trans->state == SCTP_UNCONFIRMED)
1304 trans_next = sctp_trans_elect_best(trans, trans_next);
1305 /* Active is good enough for immediate return. */
1306 if (trans_next->state == SCTP_ACTIVE)
1308 /* We've reached the end, time to update path. */
1309 if (trans == asoc->peer.retran_path)
1313 asoc->peer.retran_path = trans_next;
1315 pr_debug("%s: association:%p updated new path to addr:%pISpc\n",
1316 __func__, asoc, &asoc->peer.retran_path->ipaddr.sa);
1319 static void sctp_select_active_and_retran_path(struct sctp_association *asoc)
1321 struct sctp_transport *trans, *trans_pri = NULL, *trans_sec = NULL;
1322 struct sctp_transport *trans_pf = NULL;
1324 /* Look for the two most recently used active transports. */
1325 list_for_each_entry(trans, &asoc->peer.transport_addr_list,
1327 /* Skip uninteresting transports. */
1328 if (trans->state == SCTP_INACTIVE ||
1329 trans->state == SCTP_UNCONFIRMED)
1331 /* Keep track of the best PF transport from our
1332 * list in case we don't find an active one.
1334 if (trans->state == SCTP_PF) {
1335 trans_pf = sctp_trans_elect_best(trans, trans_pf);
1338 /* For active transports, pick the most recent ones. */
1339 if (trans_pri == NULL ||
1340 ktime_after(trans->last_time_heard,
1341 trans_pri->last_time_heard)) {
1342 trans_sec = trans_pri;
1344 } else if (trans_sec == NULL ||
1345 ktime_after(trans->last_time_heard,
1346 trans_sec->last_time_heard)) {
1351 /* RFC 2960 6.4 Multi-Homed SCTP Endpoints
1353 * By default, an endpoint should always transmit to the primary
1354 * path, unless the SCTP user explicitly specifies the
1355 * destination transport address (and possibly source transport
1356 * address) to use. [If the primary is active but not most recent,
1357 * bump the most recently used transport.]
1359 if ((asoc->peer.primary_path->state == SCTP_ACTIVE ||
1360 asoc->peer.primary_path->state == SCTP_UNKNOWN) &&
1361 asoc->peer.primary_path != trans_pri) {
1362 trans_sec = trans_pri;
1363 trans_pri = asoc->peer.primary_path;
1366 /* We did not find anything useful for a possible retransmission
1367 * path; either primary path that we found is the the same as
1368 * the current one, or we didn't generally find an active one.
1370 if (trans_sec == NULL)
1371 trans_sec = trans_pri;
1373 /* If we failed to find a usable transport, just camp on the
1374 * active or pick a PF iff it's the better choice.
1376 if (trans_pri == NULL) {
1377 trans_pri = sctp_trans_elect_best(asoc->peer.active_path, trans_pf);
1378 trans_sec = trans_pri;
1381 /* Set the active and retran transports. */
1382 asoc->peer.active_path = trans_pri;
1383 asoc->peer.retran_path = trans_sec;
1386 struct sctp_transport *
1387 sctp_assoc_choose_alter_transport(struct sctp_association *asoc,
1388 struct sctp_transport *last_sent_to)
1390 /* If this is the first time packet is sent, use the active path,
1391 * else use the retran path. If the last packet was sent over the
1392 * retran path, update the retran path and use it.
1394 if (last_sent_to == NULL) {
1395 return asoc->peer.active_path;
1397 if (last_sent_to == asoc->peer.retran_path)
1398 sctp_assoc_update_retran_path(asoc);
1400 return asoc->peer.retran_path;
1404 void sctp_assoc_update_frag_point(struct sctp_association *asoc)
1406 int frag = sctp_mtu_payload(sctp_sk(asoc->base.sk), asoc->pathmtu,
1407 sctp_datachk_len(&asoc->stream));
1409 if (asoc->user_frag)
1410 frag = min_t(int, frag, asoc->user_frag);
1412 frag = min_t(int, frag, SCTP_MAX_CHUNK_LEN -
1413 sctp_datachk_len(&asoc->stream));
1415 asoc->frag_point = SCTP_TRUNC4(frag);
1418 void sctp_assoc_set_pmtu(struct sctp_association *asoc, __u32 pmtu)
1420 if (asoc->pathmtu != pmtu) {
1421 asoc->pathmtu = pmtu;
1422 sctp_assoc_update_frag_point(asoc);
1425 pr_debug("%s: asoc:%p, pmtu:%d, frag_point:%d\n", __func__, asoc,
1426 asoc->pathmtu, asoc->frag_point);
1429 /* Update the association's pmtu and frag_point by going through all the
1430 * transports. This routine is called when a transport's PMTU has changed.
1432 void sctp_assoc_sync_pmtu(struct sctp_association *asoc)
1434 struct sctp_transport *t;
1440 /* Get the lowest pmtu of all the transports. */
1441 list_for_each_entry(t, &asoc->peer.transport_addr_list, transports) {
1442 if (t->pmtu_pending && t->dst) {
1443 sctp_transport_update_pmtu(t,
1444 atomic_read(&t->mtu_info));
1445 t->pmtu_pending = 0;
1447 if (!pmtu || (t->pathmtu < pmtu))
1451 sctp_assoc_set_pmtu(asoc, pmtu);
1454 /* Should we send a SACK to update our peer? */
1455 static inline bool sctp_peer_needs_update(struct sctp_association *asoc)
1457 struct net *net = sock_net(asoc->base.sk);
1458 switch (asoc->state) {
1459 case SCTP_STATE_ESTABLISHED:
1460 case SCTP_STATE_SHUTDOWN_PENDING:
1461 case SCTP_STATE_SHUTDOWN_RECEIVED:
1462 case SCTP_STATE_SHUTDOWN_SENT:
1463 if ((asoc->rwnd > asoc->a_rwnd) &&
1464 ((asoc->rwnd - asoc->a_rwnd) >= max_t(__u32,
1465 (asoc->base.sk->sk_rcvbuf >> net->sctp.rwnd_upd_shift),
1475 /* Increase asoc's rwnd by len and send any window update SACK if needed. */
1476 void sctp_assoc_rwnd_increase(struct sctp_association *asoc, unsigned int len)
1478 struct sctp_chunk *sack;
1479 struct timer_list *timer;
1481 if (asoc->rwnd_over) {
1482 if (asoc->rwnd_over >= len) {
1483 asoc->rwnd_over -= len;
1485 asoc->rwnd += (len - asoc->rwnd_over);
1486 asoc->rwnd_over = 0;
1492 /* If we had window pressure, start recovering it
1493 * once our rwnd had reached the accumulated pressure
1494 * threshold. The idea is to recover slowly, but up
1495 * to the initial advertised window.
1497 if (asoc->rwnd_press) {
1498 int change = min(asoc->pathmtu, asoc->rwnd_press);
1499 asoc->rwnd += change;
1500 asoc->rwnd_press -= change;
1503 pr_debug("%s: asoc:%p rwnd increased by %d to (%u, %u) - %u\n",
1504 __func__, asoc, len, asoc->rwnd, asoc->rwnd_over,
1507 /* Send a window update SACK if the rwnd has increased by at least the
1508 * minimum of the association's PMTU and half of the receive buffer.
1509 * The algorithm used is similar to the one described in
1510 * Section 4.2.3.3 of RFC 1122.
1512 if (sctp_peer_needs_update(asoc)) {
1513 asoc->a_rwnd = asoc->rwnd;
1515 pr_debug("%s: sending window update SACK- asoc:%p rwnd:%u "
1516 "a_rwnd:%u\n", __func__, asoc, asoc->rwnd,
1519 sack = sctp_make_sack(asoc);
1523 asoc->peer.sack_needed = 0;
1525 sctp_outq_tail(&asoc->outqueue, sack, GFP_ATOMIC);
1527 /* Stop the SACK timer. */
1528 timer = &asoc->timers[SCTP_EVENT_TIMEOUT_SACK];
1529 if (del_timer(timer))
1530 sctp_association_put(asoc);
1534 /* Decrease asoc's rwnd by len. */
1535 void sctp_assoc_rwnd_decrease(struct sctp_association *asoc, unsigned int len)
1540 if (unlikely(!asoc->rwnd || asoc->rwnd_over))
1541 pr_debug("%s: association:%p has asoc->rwnd:%u, "
1542 "asoc->rwnd_over:%u!\n", __func__, asoc,
1543 asoc->rwnd, asoc->rwnd_over);
1545 if (asoc->ep->rcvbuf_policy)
1546 rx_count = atomic_read(&asoc->rmem_alloc);
1548 rx_count = atomic_read(&asoc->base.sk->sk_rmem_alloc);
1550 /* If we've reached or overflowed our receive buffer, announce
1551 * a 0 rwnd if rwnd would still be positive. Store the
1552 * the potential pressure overflow so that the window can be restored
1553 * back to original value.
1555 if (rx_count >= asoc->base.sk->sk_rcvbuf)
1558 if (asoc->rwnd >= len) {
1561 asoc->rwnd_press += asoc->rwnd;
1565 asoc->rwnd_over += len - asoc->rwnd;
1569 pr_debug("%s: asoc:%p rwnd decreased by %d to (%u, %u, %u)\n",
1570 __func__, asoc, len, asoc->rwnd, asoc->rwnd_over,
1574 /* Build the bind address list for the association based on info from the
1575 * local endpoint and the remote peer.
1577 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
1578 enum sctp_scope scope, gfp_t gfp)
1582 /* Use scoping rules to determine the subset of addresses from
1585 flags = (PF_INET6 == asoc->base.sk->sk_family) ? SCTP_ADDR6_ALLOWED : 0;
1586 if (asoc->peer.ipv4_address)
1587 flags |= SCTP_ADDR4_PEERSUPP;
1588 if (asoc->peer.ipv6_address)
1589 flags |= SCTP_ADDR6_PEERSUPP;
1591 return sctp_bind_addr_copy(sock_net(asoc->base.sk),
1592 &asoc->base.bind_addr,
1593 &asoc->ep->base.bind_addr,
1597 /* Build the association's bind address list from the cookie. */
1598 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *asoc,
1599 struct sctp_cookie *cookie,
1602 int var_size2 = ntohs(cookie->peer_init->chunk_hdr.length);
1603 int var_size3 = cookie->raw_addr_list_len;
1604 __u8 *raw = (__u8 *)cookie->peer_init + var_size2;
1606 return sctp_raw_to_bind_addrs(&asoc->base.bind_addr, raw, var_size3,
1607 asoc->ep->base.bind_addr.port, gfp);
1610 /* Lookup laddr in the bind address list of an association. */
1611 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
1612 const union sctp_addr *laddr)
1616 if ((asoc->base.bind_addr.port == ntohs(laddr->v4.sin_port)) &&
1617 sctp_bind_addr_match(&asoc->base.bind_addr, laddr,
1618 sctp_sk(asoc->base.sk)))
1624 /* Set an association id for a given association */
1625 int sctp_assoc_set_id(struct sctp_association *asoc, gfp_t gfp)
1627 bool preload = gfpflags_allow_blocking(gfp);
1630 /* If the id is already assigned, keep it. */
1636 spin_lock_bh(&sctp_assocs_id_lock);
1637 /* 0, 1, 2 are used as SCTP_FUTURE_ASSOC, SCTP_CURRENT_ASSOC and
1638 * SCTP_ALL_ASSOC, so an available id must be > SCTP_ALL_ASSOC.
1640 ret = idr_alloc_cyclic(&sctp_assocs_id, asoc, SCTP_ALL_ASSOC + 1, 0,
1642 spin_unlock_bh(&sctp_assocs_id_lock);
1648 asoc->assoc_id = (sctp_assoc_t)ret;
1652 /* Free the ASCONF queue */
1653 static void sctp_assoc_free_asconf_queue(struct sctp_association *asoc)
1655 struct sctp_chunk *asconf;
1656 struct sctp_chunk *tmp;
1658 list_for_each_entry_safe(asconf, tmp, &asoc->addip_chunk_list, list) {
1659 list_del_init(&asconf->list);
1660 sctp_chunk_free(asconf);
1664 /* Free asconf_ack cache */
1665 static void sctp_assoc_free_asconf_acks(struct sctp_association *asoc)
1667 struct sctp_chunk *ack;
1668 struct sctp_chunk *tmp;
1670 list_for_each_entry_safe(ack, tmp, &asoc->asconf_ack_list,
1672 list_del_init(&ack->transmitted_list);
1673 sctp_chunk_free(ack);
1677 /* Clean up the ASCONF_ACK queue */
1678 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc)
1680 struct sctp_chunk *ack;
1681 struct sctp_chunk *tmp;
1683 /* We can remove all the entries from the queue up to
1684 * the "Peer-Sequence-Number".
1686 list_for_each_entry_safe(ack, tmp, &asoc->asconf_ack_list,
1688 if (ack->subh.addip_hdr->serial ==
1689 htonl(asoc->peer.addip_serial))
1692 list_del_init(&ack->transmitted_list);
1693 sctp_chunk_free(ack);
1697 /* Find the ASCONF_ACK whose serial number matches ASCONF */
1698 struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
1699 const struct sctp_association *asoc,
1702 struct sctp_chunk *ack;
1704 /* Walk through the list of cached ASCONF-ACKs and find the
1705 * ack chunk whose serial number matches that of the request.
1707 list_for_each_entry(ack, &asoc->asconf_ack_list, transmitted_list) {
1708 if (sctp_chunk_pending(ack))
1710 if (ack->subh.addip_hdr->serial == serial) {
1711 sctp_chunk_hold(ack);
1719 void sctp_asconf_queue_teardown(struct sctp_association *asoc)
1721 /* Free any cached ASCONF_ACK chunk. */
1722 sctp_assoc_free_asconf_acks(asoc);
1724 /* Free the ASCONF queue. */
1725 sctp_assoc_free_asconf_queue(asoc);
1727 /* Free any cached ASCONF chunk. */
1728 if (asoc->addip_last_asconf)
1729 sctp_chunk_free(asoc->addip_last_asconf);