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, write to
26 * the Free Software Foundation, 59 Temple Place - Suite 330,
27 * Boston, MA 02111-1307, USA.
29 * Please send any bug reports or fixes you make to the
31 * lksctp developers <lksctp-developers@lists.sourceforge.net>
33 * Or submit a bug report through the following website:
34 * http://www.sf.net/projects/lksctp
36 * Written or modified by:
37 * La Monte H.P. Yarroll <piggy@acm.org>
38 * Karl Knutson <karl@athena.chicago.il.us>
39 * Jon Grimm <jgrimm@us.ibm.com>
40 * Xingang Guo <xingang.guo@intel.com>
41 * Hui Huang <hui.huang@nokia.com>
42 * Sridhar Samudrala <sri@us.ibm.com>
43 * Daisy Chang <daisyc@us.ibm.com>
44 * Ryan Layer <rmlayer@us.ibm.com>
45 * Kevin Gao <kevin.gao@intel.com>
47 * Any bugs reported given to us we will try to fix... any fixes shared will
48 * be incorporated into the next SCTP release.
51 #include <linux/types.h>
52 #include <linux/fcntl.h>
53 #include <linux/poll.h>
54 #include <linux/init.h>
56 #include <linux/slab.h>
59 #include <net/sctp/sctp.h>
60 #include <net/sctp/sm.h>
62 /* Forward declarations for internal functions. */
63 static void sctp_assoc_bh_rcv(struct work_struct *work);
64 static void sctp_assoc_free_asconf_acks(struct sctp_association *asoc);
66 /* Keep track of the new idr low so that we don't re-use association id
67 * numbers too fast. It is protected by they idr spin lock is in the
68 * range of 1 - INT_MAX.
70 static u32 idr_low = 1;
73 /* 1st Level Abstractions. */
75 /* Initialize a new association from provided memory. */
76 static struct sctp_association *sctp_association_init(struct sctp_association *asoc,
77 const struct sctp_endpoint *ep,
78 const struct sock *sk,
87 /* Retrieve the SCTP per socket area. */
88 sp = sctp_sk((struct sock *)sk);
90 /* Discarding const is appropriate here. */
91 asoc->ep = (struct sctp_endpoint *)ep;
92 sctp_endpoint_hold(asoc->ep);
95 asoc->base.sk = (struct sock *)sk;
96 sock_hold(asoc->base.sk);
98 /* Initialize the common base substructure. */
99 asoc->base.type = SCTP_EP_TYPE_ASSOCIATION;
101 /* Initialize the object handling fields. */
102 atomic_set(&asoc->base.refcnt, 1);
104 asoc->base.malloced = 0;
106 /* Initialize the bind addr area. */
107 sctp_bind_addr_init(&asoc->base.bind_addr, ep->base.bind_addr.port);
109 asoc->state = SCTP_STATE_CLOSED;
111 /* Set these values from the socket values, a conversion between
112 * millsecons to seconds/microseconds must also be done.
114 asoc->cookie_life.tv_sec = sp->assocparams.sasoc_cookie_life / 1000;
115 asoc->cookie_life.tv_usec = (sp->assocparams.sasoc_cookie_life % 1000)
117 asoc->frag_point = 0;
118 asoc->user_frag = sp->user_frag;
120 /* Set the association max_retrans and RTO values from the
123 asoc->max_retrans = sp->assocparams.sasoc_asocmaxrxt;
124 asoc->rto_initial = msecs_to_jiffies(sp->rtoinfo.srto_initial);
125 asoc->rto_max = msecs_to_jiffies(sp->rtoinfo.srto_max);
126 asoc->rto_min = msecs_to_jiffies(sp->rtoinfo.srto_min);
128 asoc->overall_error_count = 0;
130 /* Initialize the association's heartbeat interval based on the
131 * sock configured value.
133 asoc->hbinterval = msecs_to_jiffies(sp->hbinterval);
135 /* Initialize path max retrans value. */
136 asoc->pathmaxrxt = sp->pathmaxrxt;
138 /* Initialize default path MTU. */
139 asoc->pathmtu = sp->pathmtu;
141 /* Set association default SACK delay */
142 asoc->sackdelay = msecs_to_jiffies(sp->sackdelay);
143 asoc->sackfreq = sp->sackfreq;
145 /* Set the association default flags controlling
146 * Heartbeat, SACK delay, and Path MTU Discovery.
148 asoc->param_flags = sp->param_flags;
150 /* Initialize the maximum mumber of new data packets that can be sent
153 asoc->max_burst = sp->max_burst;
155 /* initialize association timers */
156 asoc->timeouts[SCTP_EVENT_TIMEOUT_NONE] = 0;
157 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] = asoc->rto_initial;
158 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] = asoc->rto_initial;
159 asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = asoc->rto_initial;
160 asoc->timeouts[SCTP_EVENT_TIMEOUT_T3_RTX] = 0;
161 asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = 0;
163 /* sctpimpguide Section 2.12.2
164 * If the 'T5-shutdown-guard' timer is used, it SHOULD be set to the
165 * recommended value of 5 times 'RTO.Max'.
167 asoc->timeouts[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD]
170 asoc->timeouts[SCTP_EVENT_TIMEOUT_HEARTBEAT] = 0;
171 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] = asoc->sackdelay;
172 asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE] =
173 (unsigned long)sp->autoclose * HZ;
175 /* Initilizes the timers */
176 for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i)
177 setup_timer(&asoc->timers[i], sctp_timer_events[i],
178 (unsigned long)asoc);
180 /* Pull default initialization values from the sock options.
181 * Note: This assumes that the values have already been
182 * validated in the sock.
184 asoc->c.sinit_max_instreams = sp->initmsg.sinit_max_instreams;
185 asoc->c.sinit_num_ostreams = sp->initmsg.sinit_num_ostreams;
186 asoc->max_init_attempts = sp->initmsg.sinit_max_attempts;
188 asoc->max_init_timeo =
189 msecs_to_jiffies(sp->initmsg.sinit_max_init_timeo);
191 /* Allocate storage for the ssnmap after the inbound and outbound
192 * streams have been negotiated during Init.
196 /* Set the local window size for receive.
197 * This is also the rcvbuf space per association.
198 * RFC 6 - A SCTP receiver MUST be able to receive a minimum of
199 * 1500 bytes in one SCTP packet.
201 if ((sk->sk_rcvbuf/2) < SCTP_DEFAULT_MINWINDOW)
202 asoc->rwnd = SCTP_DEFAULT_MINWINDOW;
204 asoc->rwnd = sk->sk_rcvbuf/2;
206 asoc->a_rwnd = asoc->rwnd;
209 asoc->rwnd_press = 0;
211 /* Use my own max window until I learn something better. */
212 asoc->peer.rwnd = SCTP_DEFAULT_MAXWINDOW;
214 /* Set the sndbuf size for transmit. */
215 asoc->sndbuf_used = 0;
217 /* Initialize the receive memory counter */
218 atomic_set(&asoc->rmem_alloc, 0);
220 init_waitqueue_head(&asoc->wait);
222 asoc->c.my_vtag = sctp_generate_tag(ep);
223 asoc->peer.i.init_tag = 0; /* INIT needs a vtag of 0. */
224 asoc->c.peer_vtag = 0;
226 asoc->c.peer_ttag = 0;
227 asoc->c.my_port = ep->base.bind_addr.port;
229 asoc->c.initial_tsn = sctp_generate_tsn(ep);
231 asoc->next_tsn = asoc->c.initial_tsn;
233 asoc->ctsn_ack_point = asoc->next_tsn - 1;
234 asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
235 asoc->highest_sacked = asoc->ctsn_ack_point;
236 asoc->last_cwr_tsn = asoc->ctsn_ack_point;
237 asoc->unack_data = 0;
239 /* ADDIP Section 4.1 Asconf Chunk Procedures
241 * When an endpoint has an ASCONF signaled change to be sent to the
242 * remote endpoint it should do the following:
244 * A2) a serial number should be assigned to the chunk. The serial
245 * number SHOULD be a monotonically increasing number. The serial
246 * numbers SHOULD be initialized at the start of the
247 * association to the same value as the initial TSN.
249 asoc->addip_serial = asoc->c.initial_tsn;
251 INIT_LIST_HEAD(&asoc->addip_chunk_list);
252 INIT_LIST_HEAD(&asoc->asconf_ack_list);
254 /* Make an empty list of remote transport addresses. */
255 INIT_LIST_HEAD(&asoc->peer.transport_addr_list);
256 asoc->peer.transport_count = 0;
258 /* RFC 2960 5.1 Normal Establishment of an Association
260 * After the reception of the first data chunk in an
261 * association the endpoint must immediately respond with a
262 * sack to acknowledge the data chunk. Subsequent
263 * acknowledgements should be done as described in Section
266 * [We implement this by telling a new association that it
267 * already received one packet.]
269 asoc->peer.sack_needed = 1;
270 asoc->peer.sack_cnt = 0;
272 /* Assume that the peer will tell us if he recognizes ASCONF
273 * as part of INIT exchange.
274 * The sctp_addip_noauth option is there for backward compatibilty
275 * and will revert old behavior.
277 asoc->peer.asconf_capable = 0;
278 if (sctp_addip_noauth)
279 asoc->peer.asconf_capable = 1;
281 /* Create an input queue. */
282 sctp_inq_init(&asoc->base.inqueue);
283 sctp_inq_set_th_handler(&asoc->base.inqueue, sctp_assoc_bh_rcv);
285 /* Create an output queue. */
286 sctp_outq_init(asoc, &asoc->outqueue);
288 if (!sctp_ulpq_init(&asoc->ulpq, asoc))
291 memset(&asoc->peer.tsn_map, 0, sizeof(struct sctp_tsnmap));
297 /* Assume that peer would support both address types unless we are
300 asoc->peer.ipv4_address = 1;
301 if (asoc->base.sk->sk_family == PF_INET6)
302 asoc->peer.ipv6_address = 1;
303 INIT_LIST_HEAD(&asoc->asocs);
305 asoc->autoclose = sp->autoclose;
307 asoc->default_stream = sp->default_stream;
308 asoc->default_ppid = sp->default_ppid;
309 asoc->default_flags = sp->default_flags;
310 asoc->default_context = sp->default_context;
311 asoc->default_timetolive = sp->default_timetolive;
312 asoc->default_rcv_context = sp->default_rcv_context;
314 /* AUTH related initializations */
315 INIT_LIST_HEAD(&asoc->endpoint_shared_keys);
316 err = sctp_auth_asoc_copy_shkeys(ep, asoc, gfp);
320 asoc->active_key_id = ep->active_key_id;
321 asoc->asoc_shared_key = NULL;
323 asoc->default_hmac_id = 0;
324 /* Save the hmacs and chunks list into this association */
325 if (ep->auth_hmacs_list)
326 memcpy(asoc->c.auth_hmacs, ep->auth_hmacs_list,
327 ntohs(ep->auth_hmacs_list->param_hdr.length));
328 if (ep->auth_chunk_list)
329 memcpy(asoc->c.auth_chunks, ep->auth_chunk_list,
330 ntohs(ep->auth_chunk_list->param_hdr.length));
332 /* Get the AUTH random number for this association */
333 p = (sctp_paramhdr_t *)asoc->c.auth_random;
334 p->type = SCTP_PARAM_RANDOM;
335 p->length = htons(sizeof(sctp_paramhdr_t) + SCTP_AUTH_RANDOM_LENGTH);
336 get_random_bytes(p+1, SCTP_AUTH_RANDOM_LENGTH);
341 sctp_endpoint_put(asoc->ep);
342 sock_put(asoc->base.sk);
346 /* Allocate and initialize a new association */
347 struct sctp_association *sctp_association_new(const struct sctp_endpoint *ep,
348 const struct sock *sk,
352 struct sctp_association *asoc;
354 asoc = t_new(struct sctp_association, gfp);
358 if (!sctp_association_init(asoc, ep, sk, scope, gfp))
361 asoc->base.malloced = 1;
362 SCTP_DBG_OBJCNT_INC(assoc);
363 SCTP_DEBUG_PRINTK("Created asoc %p\n", asoc);
373 /* Free this association if possible. There may still be users, so
374 * the actual deallocation may be delayed.
376 void sctp_association_free(struct sctp_association *asoc)
378 struct sock *sk = asoc->base.sk;
379 struct sctp_transport *transport;
380 struct list_head *pos, *temp;
383 /* Only real associations count against the endpoint, so
384 * don't bother for if this is a temporary association.
387 list_del(&asoc->asocs);
389 /* Decrement the backlog value for a TCP-style listening
392 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
393 sk->sk_ack_backlog--;
396 /* Mark as dead, so other users can know this structure is
401 /* Dispose of any data lying around in the outqueue. */
402 sctp_outq_free(&asoc->outqueue);
404 /* Dispose of any pending messages for the upper layer. */
405 sctp_ulpq_free(&asoc->ulpq);
407 /* Dispose of any pending chunks on the inqueue. */
408 sctp_inq_free(&asoc->base.inqueue);
410 sctp_tsnmap_free(&asoc->peer.tsn_map);
412 /* Free ssnmap storage. */
413 sctp_ssnmap_free(asoc->ssnmap);
415 /* Clean up the bound address list. */
416 sctp_bind_addr_free(&asoc->base.bind_addr);
418 /* Do we need to go through all of our timers and
419 * delete them? To be safe we will try to delete all, but we
420 * should be able to go through and make a guess based
423 for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i) {
424 if (timer_pending(&asoc->timers[i]) &&
425 del_timer(&asoc->timers[i]))
426 sctp_association_put(asoc);
429 /* Free peer's cached cookie. */
430 kfree(asoc->peer.cookie);
431 kfree(asoc->peer.peer_random);
432 kfree(asoc->peer.peer_chunks);
433 kfree(asoc->peer.peer_hmacs);
435 /* Release the transport structures. */
436 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
437 transport = list_entry(pos, struct sctp_transport, transports);
439 sctp_transport_free(transport);
442 asoc->peer.transport_count = 0;
444 /* Free any cached ASCONF_ACK chunk. */
445 sctp_assoc_free_asconf_acks(asoc);
447 /* Free any cached ASCONF chunk. */
448 if (asoc->addip_last_asconf)
449 sctp_chunk_free(asoc->addip_last_asconf);
451 /* AUTH - Free the endpoint shared keys */
452 sctp_auth_destroy_keys(&asoc->endpoint_shared_keys);
454 /* AUTH - Free the association shared key */
455 sctp_auth_key_put(asoc->asoc_shared_key);
457 sctp_association_put(asoc);
460 /* Cleanup and free up an association. */
461 static void sctp_association_destroy(struct sctp_association *asoc)
463 SCTP_ASSERT(asoc->base.dead, "Assoc is not dead", return);
465 sctp_endpoint_put(asoc->ep);
466 sock_put(asoc->base.sk);
468 if (asoc->assoc_id != 0) {
469 spin_lock_bh(&sctp_assocs_id_lock);
470 idr_remove(&sctp_assocs_id, asoc->assoc_id);
471 spin_unlock_bh(&sctp_assocs_id_lock);
474 WARN_ON(atomic_read(&asoc->rmem_alloc));
476 if (asoc->base.malloced) {
478 SCTP_DBG_OBJCNT_DEC(assoc);
482 /* Change the primary destination address for the peer. */
483 void sctp_assoc_set_primary(struct sctp_association *asoc,
484 struct sctp_transport *transport)
488 /* it's a changeover only if we already have a primary path
489 * that we are changing
491 if (asoc->peer.primary_path != NULL &&
492 asoc->peer.primary_path != transport)
495 asoc->peer.primary_path = transport;
497 /* Set a default msg_name for events. */
498 memcpy(&asoc->peer.primary_addr, &transport->ipaddr,
499 sizeof(union sctp_addr));
501 /* If the primary path is changing, assume that the
502 * user wants to use this new path.
504 if ((transport->state == SCTP_ACTIVE) ||
505 (transport->state == SCTP_UNKNOWN))
506 asoc->peer.active_path = transport;
509 * SFR-CACC algorithm:
510 * Upon the receipt of a request to change the primary
511 * destination address, on the data structure for the new
512 * primary destination, the sender MUST do the following:
514 * 1) If CHANGEOVER_ACTIVE is set, then there was a switch
515 * to this destination address earlier. The sender MUST set
516 * CYCLING_CHANGEOVER to indicate that this switch is a
517 * double switch to the same destination address.
519 * Really, only bother is we have data queued or outstanding on
522 if (!asoc->outqueue.outstanding_bytes && !asoc->outqueue.out_qlen)
525 if (transport->cacc.changeover_active)
526 transport->cacc.cycling_changeover = changeover;
528 /* 2) The sender MUST set CHANGEOVER_ACTIVE to indicate that
529 * a changeover has occurred.
531 transport->cacc.changeover_active = changeover;
533 /* 3) The sender MUST store the next TSN to be sent in
534 * next_tsn_at_change.
536 transport->cacc.next_tsn_at_change = asoc->next_tsn;
539 /* Remove a transport from an association. */
540 void sctp_assoc_rm_peer(struct sctp_association *asoc,
541 struct sctp_transport *peer)
543 struct list_head *pos;
544 struct sctp_transport *transport;
546 SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_rm_peer:association %p addr: ",
550 ntohs(peer->ipaddr.v4.sin_port));
552 /* If we are to remove the current retran_path, update it
553 * to the next peer before removing this peer from the list.
555 if (asoc->peer.retran_path == peer)
556 sctp_assoc_update_retran_path(asoc);
558 /* Remove this peer from the list. */
559 list_del(&peer->transports);
561 /* Get the first transport of asoc. */
562 pos = asoc->peer.transport_addr_list.next;
563 transport = list_entry(pos, struct sctp_transport, transports);
565 /* Update any entries that match the peer to be deleted. */
566 if (asoc->peer.primary_path == peer)
567 sctp_assoc_set_primary(asoc, transport);
568 if (asoc->peer.active_path == peer)
569 asoc->peer.active_path = transport;
570 if (asoc->peer.last_data_from == peer)
571 asoc->peer.last_data_from = transport;
573 /* If we remove the transport an INIT was last sent to, set it to
574 * NULL. Combined with the update of the retran path above, this
575 * will cause the next INIT to be sent to the next available
576 * transport, maintaining the cycle.
578 if (asoc->init_last_sent_to == peer)
579 asoc->init_last_sent_to = NULL;
581 /* If we remove the transport an SHUTDOWN was last sent to, set it
582 * to NULL. Combined with the update of the retran path above, this
583 * will cause the next SHUTDOWN to be sent to the next available
584 * transport, maintaining the cycle.
586 if (asoc->shutdown_last_sent_to == peer)
587 asoc->shutdown_last_sent_to = NULL;
589 /* If we remove the transport an ASCONF was last sent to, set it to
592 if (asoc->addip_last_asconf &&
593 asoc->addip_last_asconf->transport == peer)
594 asoc->addip_last_asconf->transport = NULL;
596 /* If we have something on the transmitted list, we have to
597 * save it off. The best place is the active path.
599 if (!list_empty(&peer->transmitted)) {
600 struct sctp_transport *active = asoc->peer.active_path;
601 struct sctp_chunk *ch;
603 /* Reset the transport of each chunk on this list */
604 list_for_each_entry(ch, &peer->transmitted,
606 ch->transport = NULL;
607 ch->rtt_in_progress = 0;
610 list_splice_tail_init(&peer->transmitted,
611 &active->transmitted);
613 /* Start a T3 timer here in case it wasn't running so
614 * that these migrated packets have a chance to get
617 if (!timer_pending(&active->T3_rtx_timer))
618 if (!mod_timer(&active->T3_rtx_timer,
619 jiffies + active->rto))
620 sctp_transport_hold(active);
623 asoc->peer.transport_count--;
625 sctp_transport_free(peer);
628 /* Add a transport address to an association. */
629 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc,
630 const union sctp_addr *addr,
632 const int peer_state)
634 struct sctp_transport *peer;
635 struct sctp_sock *sp;
638 sp = sctp_sk(asoc->base.sk);
640 /* AF_INET and AF_INET6 share common port field. */
641 port = ntohs(addr->v4.sin_port);
643 SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_add_peer:association %p addr: ",
644 " port: %d state:%d\n",
650 /* Set the port if it has not been set yet. */
651 if (0 == asoc->peer.port)
652 asoc->peer.port = port;
654 /* Check to see if this is a duplicate. */
655 peer = sctp_assoc_lookup_paddr(asoc, addr);
657 /* An UNKNOWN state is only set on transports added by
658 * user in sctp_connectx() call. Such transports should be
659 * considered CONFIRMED per RFC 4960, Section 5.4.
661 if (peer->state == SCTP_UNKNOWN) {
662 peer->state = SCTP_ACTIVE;
667 peer = sctp_transport_new(addr, gfp);
671 sctp_transport_set_owner(peer, asoc);
673 /* Initialize the peer's heartbeat interval based on the
674 * association configured value.
676 peer->hbinterval = asoc->hbinterval;
678 /* Set the path max_retrans. */
679 peer->pathmaxrxt = asoc->pathmaxrxt;
681 /* Initialize the peer's SACK delay timeout based on the
682 * association configured value.
684 peer->sackdelay = asoc->sackdelay;
685 peer->sackfreq = asoc->sackfreq;
687 /* Enable/disable heartbeat, SACK delay, and path MTU discovery
688 * based on association setting.
690 peer->param_flags = asoc->param_flags;
692 sctp_transport_route(peer, NULL, sp);
694 /* Initialize the pmtu of the transport. */
695 if (peer->param_flags & SPP_PMTUD_DISABLE) {
697 peer->pathmtu = asoc->pathmtu;
699 peer->pathmtu = SCTP_DEFAULT_MAXSEGMENT;
702 /* If this is the first transport addr on this association,
703 * initialize the association PMTU to the peer's PMTU.
704 * If not and the current association PMTU is higher than the new
705 * peer's PMTU, reset the association PMTU to the new peer's PMTU.
708 asoc->pathmtu = min_t(int, peer->pathmtu, asoc->pathmtu);
710 asoc->pathmtu = peer->pathmtu;
712 SCTP_DEBUG_PRINTK("sctp_assoc_add_peer:association %p PMTU set to "
713 "%d\n", asoc, asoc->pathmtu);
714 peer->pmtu_pending = 0;
716 asoc->frag_point = sctp_frag_point(asoc, asoc->pathmtu);
718 /* The asoc->peer.port might not be meaningful yet, but
719 * initialize the packet structure anyway.
721 sctp_packet_init(&peer->packet, peer, asoc->base.bind_addr.port,
726 * o The initial cwnd before DATA transmission or after a sufficiently
727 * long idle period MUST be set to
728 * min(4*MTU, max(2*MTU, 4380 bytes))
730 * o The initial value of ssthresh MAY be arbitrarily high
731 * (for example, implementations MAY use the size of the
732 * receiver advertised window).
734 peer->cwnd = min(4*asoc->pathmtu, max_t(__u32, 2*asoc->pathmtu, 4380));
736 /* At this point, we may not have the receiver's advertised window,
737 * so initialize ssthresh to the default value and it will be set
738 * later when we process the INIT.
740 peer->ssthresh = SCTP_DEFAULT_MAXWINDOW;
742 peer->partial_bytes_acked = 0;
743 peer->flight_size = 0;
744 peer->burst_limited = 0;
746 /* Set the transport's RTO.initial value */
747 peer->rto = asoc->rto_initial;
749 /* Set the peer's active state. */
750 peer->state = peer_state;
752 /* Attach the remote transport to our asoc. */
753 list_add_tail(&peer->transports, &asoc->peer.transport_addr_list);
754 asoc->peer.transport_count++;
756 /* If we do not yet have a primary path, set one. */
757 if (!asoc->peer.primary_path) {
758 sctp_assoc_set_primary(asoc, peer);
759 asoc->peer.retran_path = peer;
762 if (asoc->peer.active_path == asoc->peer.retran_path &&
763 peer->state != SCTP_UNCONFIRMED) {
764 asoc->peer.retran_path = peer;
770 /* Delete a transport address from an association. */
771 void sctp_assoc_del_peer(struct sctp_association *asoc,
772 const union sctp_addr *addr)
774 struct list_head *pos;
775 struct list_head *temp;
776 struct sctp_transport *transport;
778 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
779 transport = list_entry(pos, struct sctp_transport, transports);
780 if (sctp_cmp_addr_exact(addr, &transport->ipaddr)) {
781 /* Do book keeping for removing the peer and free it. */
782 sctp_assoc_rm_peer(asoc, transport);
788 /* Lookup a transport by address. */
789 struct sctp_transport *sctp_assoc_lookup_paddr(
790 const struct sctp_association *asoc,
791 const union sctp_addr *address)
793 struct sctp_transport *t;
795 /* Cycle through all transports searching for a peer address. */
797 list_for_each_entry(t, &asoc->peer.transport_addr_list,
799 if (sctp_cmp_addr_exact(address, &t->ipaddr))
806 /* Remove all transports except a give one */
807 void sctp_assoc_del_nonprimary_peers(struct sctp_association *asoc,
808 struct sctp_transport *primary)
810 struct sctp_transport *temp;
811 struct sctp_transport *t;
813 list_for_each_entry_safe(t, temp, &asoc->peer.transport_addr_list,
815 /* if the current transport is not the primary one, delete it */
817 sctp_assoc_rm_peer(asoc, t);
823 /* Engage in transport control operations.
824 * Mark the transport up or down and send a notification to the user.
825 * Select and update the new active and retran paths.
827 void sctp_assoc_control_transport(struct sctp_association *asoc,
828 struct sctp_transport *transport,
829 sctp_transport_cmd_t command,
830 sctp_sn_error_t error)
832 struct sctp_transport *t = NULL;
833 struct sctp_transport *first;
834 struct sctp_transport *second;
835 struct sctp_ulpevent *event;
836 struct sockaddr_storage addr;
839 /* Record the transition on the transport. */
841 case SCTP_TRANSPORT_UP:
842 /* If we are moving from UNCONFIRMED state due
843 * to heartbeat success, report the SCTP_ADDR_CONFIRMED
844 * state to the user, otherwise report SCTP_ADDR_AVAILABLE.
846 if (SCTP_UNCONFIRMED == transport->state &&
847 SCTP_HEARTBEAT_SUCCESS == error)
848 spc_state = SCTP_ADDR_CONFIRMED;
850 spc_state = SCTP_ADDR_AVAILABLE;
851 transport->state = SCTP_ACTIVE;
854 case SCTP_TRANSPORT_DOWN:
855 /* If the transport was never confirmed, do not transition it
856 * to inactive state. Also, release the cached route since
857 * there may be a better route next time.
859 if (transport->state != SCTP_UNCONFIRMED)
860 transport->state = SCTP_INACTIVE;
862 dst_release(transport->dst);
863 transport->dst = NULL;
866 spc_state = SCTP_ADDR_UNREACHABLE;
873 /* Generate and send a SCTP_PEER_ADDR_CHANGE notification to the
876 memset(&addr, 0, sizeof(struct sockaddr_storage));
877 memcpy(&addr, &transport->ipaddr, transport->af_specific->sockaddr_len);
878 event = sctp_ulpevent_make_peer_addr_change(asoc, &addr,
879 0, spc_state, error, GFP_ATOMIC);
881 sctp_ulpq_tail_event(&asoc->ulpq, event);
883 /* Select new active and retran paths. */
885 /* Look for the two most recently used active transports.
887 * This code produces the wrong ordering whenever jiffies
888 * rolls over, but we still get usable transports, so we don't
891 first = NULL; second = NULL;
893 list_for_each_entry(t, &asoc->peer.transport_addr_list,
896 if ((t->state == SCTP_INACTIVE) ||
897 (t->state == SCTP_UNCONFIRMED))
899 if (!first || t->last_time_heard > first->last_time_heard) {
903 if (!second || t->last_time_heard > second->last_time_heard)
907 /* RFC 2960 6.4 Multi-Homed SCTP Endpoints
909 * By default, an endpoint should always transmit to the
910 * primary path, unless the SCTP user explicitly specifies the
911 * destination transport address (and possibly source
912 * transport address) to use.
914 * [If the primary is active but not most recent, bump the most
915 * recently used transport.]
917 if (((asoc->peer.primary_path->state == SCTP_ACTIVE) ||
918 (asoc->peer.primary_path->state == SCTP_UNKNOWN)) &&
919 first != asoc->peer.primary_path) {
921 first = asoc->peer.primary_path;
924 /* If we failed to find a usable transport, just camp on the
925 * primary, even if it is inactive.
928 first = asoc->peer.primary_path;
929 second = asoc->peer.primary_path;
932 /* Set the active and retran transports. */
933 asoc->peer.active_path = first;
934 asoc->peer.retran_path = second;
937 /* Hold a reference to an association. */
938 void sctp_association_hold(struct sctp_association *asoc)
940 atomic_inc(&asoc->base.refcnt);
943 /* Release a reference to an association and cleanup
944 * if there are no more references.
946 void sctp_association_put(struct sctp_association *asoc)
948 if (atomic_dec_and_test(&asoc->base.refcnt))
949 sctp_association_destroy(asoc);
952 /* Allocate the next TSN, Transmission Sequence Number, for the given
955 __u32 sctp_association_get_next_tsn(struct sctp_association *asoc)
957 /* From Section 1.6 Serial Number Arithmetic:
958 * Transmission Sequence Numbers wrap around when they reach
959 * 2**32 - 1. That is, the next TSN a DATA chunk MUST use
960 * after transmitting TSN = 2*32 - 1 is TSN = 0.
962 __u32 retval = asoc->next_tsn;
969 /* Compare two addresses to see if they match. Wildcard addresses
970 * only match themselves.
972 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
973 const union sctp_addr *ss2)
977 af = sctp_get_af_specific(ss1->sa.sa_family);
981 return af->cmp_addr(ss1, ss2);
984 /* Return an ecne chunk to get prepended to a packet.
985 * Note: We are sly and return a shared, prealloced chunk. FIXME:
986 * No we don't, but we could/should.
988 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc)
990 struct sctp_chunk *chunk;
992 /* Send ECNE if needed.
993 * Not being able to allocate a chunk here is not deadly.
996 chunk = sctp_make_ecne(asoc, asoc->last_ecne_tsn);
1004 * Find which transport this TSN was sent on.
1006 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *asoc,
1009 struct sctp_transport *active;
1010 struct sctp_transport *match;
1011 struct sctp_transport *transport;
1012 struct sctp_chunk *chunk;
1013 __be32 key = htonl(tsn);
1018 * FIXME: In general, find a more efficient data structure for
1023 * The general strategy is to search each transport's transmitted
1024 * list. Return which transport this TSN lives on.
1026 * Let's be hopeful and check the active_path first.
1027 * Another optimization would be to know if there is only one
1028 * outbound path and not have to look for the TSN at all.
1032 active = asoc->peer.active_path;
1034 list_for_each_entry(chunk, &active->transmitted,
1037 if (key == chunk->subh.data_hdr->tsn) {
1043 /* If not found, go search all the other transports. */
1044 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
1047 if (transport == active)
1049 list_for_each_entry(chunk, &transport->transmitted,
1051 if (key == chunk->subh.data_hdr->tsn) {
1061 /* Is this the association we are looking for? */
1062 struct sctp_transport *sctp_assoc_is_match(struct sctp_association *asoc,
1063 const union sctp_addr *laddr,
1064 const union sctp_addr *paddr)
1066 struct sctp_transport *transport;
1068 if ((htons(asoc->base.bind_addr.port) == laddr->v4.sin_port) &&
1069 (htons(asoc->peer.port) == paddr->v4.sin_port)) {
1070 transport = sctp_assoc_lookup_paddr(asoc, paddr);
1074 if (sctp_bind_addr_match(&asoc->base.bind_addr, laddr,
1075 sctp_sk(asoc->base.sk)))
1084 /* Do delayed input processing. This is scheduled by sctp_rcv(). */
1085 static void sctp_assoc_bh_rcv(struct work_struct *work)
1087 struct sctp_association *asoc =
1088 container_of(work, struct sctp_association,
1089 base.inqueue.immediate);
1090 struct sctp_endpoint *ep;
1091 struct sctp_chunk *chunk;
1093 struct sctp_inq *inqueue;
1095 sctp_subtype_t subtype;
1098 /* The association should be held so we should be safe. */
1102 inqueue = &asoc->base.inqueue;
1103 sctp_association_hold(asoc);
1104 while (NULL != (chunk = sctp_inq_pop(inqueue))) {
1105 state = asoc->state;
1106 subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type);
1108 /* SCTP-AUTH, Section 6.3:
1109 * The receiver has a list of chunk types which it expects
1110 * to be received only after an AUTH-chunk. This list has
1111 * been sent to the peer during the association setup. It
1112 * MUST silently discard these chunks if they are not placed
1113 * after an AUTH chunk in the packet.
1115 if (sctp_auth_recv_cid(subtype.chunk, asoc) && !chunk->auth)
1118 /* Remember where the last DATA chunk came from so we
1119 * know where to send the SACK.
1121 if (sctp_chunk_is_data(chunk))
1122 asoc->peer.last_data_from = chunk->transport;
1124 SCTP_INC_STATS(SCTP_MIB_INCTRLCHUNKS);
1126 if (chunk->transport)
1127 chunk->transport->last_time_heard = jiffies;
1129 /* Run through the state machine. */
1130 error = sctp_do_sm(SCTP_EVENT_T_CHUNK, subtype,
1131 state, ep, asoc, chunk, GFP_ATOMIC);
1133 /* Check to see if the association is freed in response to
1134 * the incoming chunk. If so, get out of the while loop.
1136 if (asoc->base.dead)
1139 /* If there is an error on chunk, discard this packet. */
1141 chunk->pdiscard = 1;
1143 sctp_association_put(asoc);
1146 /* This routine moves an association from its old sk to a new sk. */
1147 void sctp_assoc_migrate(struct sctp_association *assoc, struct sock *newsk)
1149 struct sctp_sock *newsp = sctp_sk(newsk);
1150 struct sock *oldsk = assoc->base.sk;
1152 /* Delete the association from the old endpoint's list of
1155 list_del_init(&assoc->asocs);
1157 /* Decrement the backlog value for a TCP-style socket. */
1158 if (sctp_style(oldsk, TCP))
1159 oldsk->sk_ack_backlog--;
1161 /* Release references to the old endpoint and the sock. */
1162 sctp_endpoint_put(assoc->ep);
1163 sock_put(assoc->base.sk);
1165 /* Get a reference to the new endpoint. */
1166 assoc->ep = newsp->ep;
1167 sctp_endpoint_hold(assoc->ep);
1169 /* Get a reference to the new sock. */
1170 assoc->base.sk = newsk;
1171 sock_hold(assoc->base.sk);
1173 /* Add the association to the new endpoint's list of associations. */
1174 sctp_endpoint_add_asoc(newsp->ep, assoc);
1177 /* Update an association (possibly from unexpected COOKIE-ECHO processing). */
1178 void sctp_assoc_update(struct sctp_association *asoc,
1179 struct sctp_association *new)
1181 struct sctp_transport *trans;
1182 struct list_head *pos, *temp;
1184 /* Copy in new parameters of peer. */
1186 asoc->peer.rwnd = new->peer.rwnd;
1187 asoc->peer.sack_needed = new->peer.sack_needed;
1188 asoc->peer.i = new->peer.i;
1189 sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
1190 asoc->peer.i.initial_tsn, GFP_ATOMIC);
1192 /* Remove any peer addresses not present in the new association. */
1193 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
1194 trans = list_entry(pos, struct sctp_transport, transports);
1195 if (!sctp_assoc_lookup_paddr(new, &trans->ipaddr)) {
1196 sctp_assoc_rm_peer(asoc, trans);
1200 if (asoc->state >= SCTP_STATE_ESTABLISHED)
1201 sctp_transport_reset(trans);
1204 /* If the case is A (association restart), use
1205 * initial_tsn as next_tsn. If the case is B, use
1206 * current next_tsn in case data sent to peer
1207 * has been discarded and needs retransmission.
1209 if (asoc->state >= SCTP_STATE_ESTABLISHED) {
1210 asoc->next_tsn = new->next_tsn;
1211 asoc->ctsn_ack_point = new->ctsn_ack_point;
1212 asoc->adv_peer_ack_point = new->adv_peer_ack_point;
1214 /* Reinitialize SSN for both local streams
1215 * and peer's streams.
1217 sctp_ssnmap_clear(asoc->ssnmap);
1219 /* Flush the ULP reassembly and ordered queue.
1220 * Any data there will now be stale and will
1223 sctp_ulpq_flush(&asoc->ulpq);
1225 /* reset the overall association error count so
1226 * that the restarted association doesn't get torn
1227 * down on the next retransmission timer.
1229 asoc->overall_error_count = 0;
1232 /* Add any peer addresses from the new association. */
1233 list_for_each_entry(trans, &new->peer.transport_addr_list,
1235 if (!sctp_assoc_lookup_paddr(asoc, &trans->ipaddr))
1236 sctp_assoc_add_peer(asoc, &trans->ipaddr,
1237 GFP_ATOMIC, trans->state);
1240 asoc->ctsn_ack_point = asoc->next_tsn - 1;
1241 asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
1242 if (!asoc->ssnmap) {
1243 /* Move the ssnmap. */
1244 asoc->ssnmap = new->ssnmap;
1248 if (!asoc->assoc_id) {
1249 /* get a new association id since we don't have one
1252 sctp_assoc_set_id(asoc, GFP_ATOMIC);
1256 /* SCTP-AUTH: Save the peer parameters from the new assocaitions
1257 * and also move the association shared keys over
1259 kfree(asoc->peer.peer_random);
1260 asoc->peer.peer_random = new->peer.peer_random;
1261 new->peer.peer_random = NULL;
1263 kfree(asoc->peer.peer_chunks);
1264 asoc->peer.peer_chunks = new->peer.peer_chunks;
1265 new->peer.peer_chunks = NULL;
1267 kfree(asoc->peer.peer_hmacs);
1268 asoc->peer.peer_hmacs = new->peer.peer_hmacs;
1269 new->peer.peer_hmacs = NULL;
1271 sctp_auth_key_put(asoc->asoc_shared_key);
1272 sctp_auth_asoc_init_active_key(asoc, GFP_ATOMIC);
1275 /* Update the retran path for sending a retransmitted packet.
1276 * Round-robin through the active transports, else round-robin
1277 * through the inactive transports as this is the next best thing
1280 void sctp_assoc_update_retran_path(struct sctp_association *asoc)
1282 struct sctp_transport *t, *next;
1283 struct list_head *head = &asoc->peer.transport_addr_list;
1284 struct list_head *pos;
1286 if (asoc->peer.transport_count == 1)
1289 /* Find the next transport in a round-robin fashion. */
1290 t = asoc->peer.retran_path;
1291 pos = &t->transports;
1295 /* Skip the head. */
1296 if (pos->next == head)
1301 t = list_entry(pos, struct sctp_transport, transports);
1303 /* We have exhausted the list, but didn't find any
1304 * other active transports. If so, use the next
1307 if (t == asoc->peer.retran_path) {
1312 /* Try to find an active transport. */
1314 if ((t->state == SCTP_ACTIVE) ||
1315 (t->state == SCTP_UNKNOWN)) {
1318 /* Keep track of the next transport in case
1319 * we don't find any active transport.
1321 if (t->state != SCTP_UNCONFIRMED && !next)
1327 asoc->peer.retran_path = t;
1329 SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_update_retran_path:association"
1334 ntohs(t->ipaddr.v4.sin_port));
1337 /* Choose the transport for sending retransmit packet. */
1338 struct sctp_transport *sctp_assoc_choose_alter_transport(
1339 struct sctp_association *asoc, struct sctp_transport *last_sent_to)
1341 /* If this is the first time packet is sent, use the active path,
1342 * else use the retran path. If the last packet was sent over the
1343 * retran path, update the retran path and use it.
1346 return asoc->peer.active_path;
1348 if (last_sent_to == asoc->peer.retran_path)
1349 sctp_assoc_update_retran_path(asoc);
1350 return asoc->peer.retran_path;
1354 /* Update the association's pmtu and frag_point by going through all the
1355 * transports. This routine is called when a transport's PMTU has changed.
1357 void sctp_assoc_sync_pmtu(struct sctp_association *asoc)
1359 struct sctp_transport *t;
1365 /* Get the lowest pmtu of all the transports. */
1366 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1368 if (t->pmtu_pending && t->dst) {
1369 sctp_transport_update_pmtu(t, dst_mtu(t->dst));
1370 t->pmtu_pending = 0;
1372 if (!pmtu || (t->pathmtu < pmtu))
1377 asoc->pathmtu = pmtu;
1378 asoc->frag_point = sctp_frag_point(asoc, pmtu);
1381 SCTP_DEBUG_PRINTK("%s: asoc:%p, pmtu:%d, frag_point:%d\n",
1382 __func__, asoc, asoc->pathmtu, asoc->frag_point);
1385 /* Should we send a SACK to update our peer? */
1386 static inline int sctp_peer_needs_update(struct sctp_association *asoc)
1388 switch (asoc->state) {
1389 case SCTP_STATE_ESTABLISHED:
1390 case SCTP_STATE_SHUTDOWN_PENDING:
1391 case SCTP_STATE_SHUTDOWN_RECEIVED:
1392 case SCTP_STATE_SHUTDOWN_SENT:
1393 if ((asoc->rwnd > asoc->a_rwnd) &&
1394 ((asoc->rwnd - asoc->a_rwnd) >= max_t(__u32,
1395 (asoc->base.sk->sk_rcvbuf >> sctp_rwnd_upd_shift),
1405 /* Increase asoc's rwnd by len and send any window update SACK if needed. */
1406 void sctp_assoc_rwnd_increase(struct sctp_association *asoc, unsigned len)
1408 struct sctp_chunk *sack;
1409 struct timer_list *timer;
1411 if (asoc->rwnd_over) {
1412 if (asoc->rwnd_over >= len) {
1413 asoc->rwnd_over -= len;
1415 asoc->rwnd += (len - asoc->rwnd_over);
1416 asoc->rwnd_over = 0;
1422 /* If we had window pressure, start recovering it
1423 * once our rwnd had reached the accumulated pressure
1424 * threshold. The idea is to recover slowly, but up
1425 * to the initial advertised window.
1427 if (asoc->rwnd_press && asoc->rwnd >= asoc->rwnd_press) {
1428 int change = min(asoc->pathmtu, asoc->rwnd_press);
1429 asoc->rwnd += change;
1430 asoc->rwnd_press -= change;
1433 SCTP_DEBUG_PRINTK("%s: asoc %p rwnd increased by %d to (%u, %u) "
1434 "- %u\n", __func__, asoc, len, asoc->rwnd,
1435 asoc->rwnd_over, asoc->a_rwnd);
1437 /* Send a window update SACK if the rwnd has increased by at least the
1438 * minimum of the association's PMTU and half of the receive buffer.
1439 * The algorithm used is similar to the one described in
1440 * Section 4.2.3.3 of RFC 1122.
1442 if (sctp_peer_needs_update(asoc)) {
1443 asoc->a_rwnd = asoc->rwnd;
1444 SCTP_DEBUG_PRINTK("%s: Sending window update SACK- asoc: %p "
1445 "rwnd: %u a_rwnd: %u\n", __func__,
1446 asoc, asoc->rwnd, asoc->a_rwnd);
1447 sack = sctp_make_sack(asoc);
1451 asoc->peer.sack_needed = 0;
1453 sctp_outq_tail(&asoc->outqueue, sack);
1455 /* Stop the SACK timer. */
1456 timer = &asoc->timers[SCTP_EVENT_TIMEOUT_SACK];
1457 if (timer_pending(timer) && del_timer(timer))
1458 sctp_association_put(asoc);
1462 /* Decrease asoc's rwnd by len. */
1463 void sctp_assoc_rwnd_decrease(struct sctp_association *asoc, unsigned len)
1468 SCTP_ASSERT(asoc->rwnd, "rwnd zero", return);
1469 SCTP_ASSERT(!asoc->rwnd_over, "rwnd_over not zero", return);
1471 if (asoc->ep->rcvbuf_policy)
1472 rx_count = atomic_read(&asoc->rmem_alloc);
1474 rx_count = atomic_read(&asoc->base.sk->sk_rmem_alloc);
1476 /* If we've reached or overflowed our receive buffer, announce
1477 * a 0 rwnd if rwnd would still be positive. Store the
1478 * the pottential pressure overflow so that the window can be restored
1479 * back to original value.
1481 if (rx_count >= asoc->base.sk->sk_rcvbuf)
1484 if (asoc->rwnd >= len) {
1487 asoc->rwnd_press += asoc->rwnd;
1491 asoc->rwnd_over = len - asoc->rwnd;
1494 SCTP_DEBUG_PRINTK("%s: asoc %p rwnd decreased by %d to (%u, %u, %u)\n",
1495 __func__, asoc, len, asoc->rwnd,
1496 asoc->rwnd_over, asoc->rwnd_press);
1499 /* Build the bind address list for the association based on info from the
1500 * local endpoint and the remote peer.
1502 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
1503 sctp_scope_t scope, gfp_t gfp)
1507 /* Use scoping rules to determine the subset of addresses from
1510 flags = (PF_INET6 == asoc->base.sk->sk_family) ? SCTP_ADDR6_ALLOWED : 0;
1511 if (asoc->peer.ipv4_address)
1512 flags |= SCTP_ADDR4_PEERSUPP;
1513 if (asoc->peer.ipv6_address)
1514 flags |= SCTP_ADDR6_PEERSUPP;
1516 return sctp_bind_addr_copy(&asoc->base.bind_addr,
1517 &asoc->ep->base.bind_addr,
1521 /* Build the association's bind address list from the cookie. */
1522 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *asoc,
1523 struct sctp_cookie *cookie,
1526 int var_size2 = ntohs(cookie->peer_init->chunk_hdr.length);
1527 int var_size3 = cookie->raw_addr_list_len;
1528 __u8 *raw = (__u8 *)cookie->peer_init + var_size2;
1530 return sctp_raw_to_bind_addrs(&asoc->base.bind_addr, raw, var_size3,
1531 asoc->ep->base.bind_addr.port, gfp);
1534 /* Lookup laddr in the bind address list of an association. */
1535 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
1536 const union sctp_addr *laddr)
1540 if ((asoc->base.bind_addr.port == ntohs(laddr->v4.sin_port)) &&
1541 sctp_bind_addr_match(&asoc->base.bind_addr, laddr,
1542 sctp_sk(asoc->base.sk)))
1548 /* Set an association id for a given association */
1549 int sctp_assoc_set_id(struct sctp_association *asoc, gfp_t gfp)
1554 /* If the id is already assigned, keep it. */
1558 if (unlikely(!idr_pre_get(&sctp_assocs_id, gfp)))
1561 spin_lock_bh(&sctp_assocs_id_lock);
1562 error = idr_get_new_above(&sctp_assocs_id, (void *)asoc,
1563 idr_low, &assoc_id);
1565 idr_low = assoc_id + 1;
1566 if (idr_low == INT_MAX)
1569 spin_unlock_bh(&sctp_assocs_id_lock);
1570 if (error == -EAGAIN)
1575 asoc->assoc_id = (sctp_assoc_t) assoc_id;
1579 /* Free asconf_ack cache */
1580 static void sctp_assoc_free_asconf_acks(struct sctp_association *asoc)
1582 struct sctp_chunk *ack;
1583 struct sctp_chunk *tmp;
1585 list_for_each_entry_safe(ack, tmp, &asoc->asconf_ack_list,
1587 list_del_init(&ack->transmitted_list);
1588 sctp_chunk_free(ack);
1592 /* Clean up the ASCONF_ACK queue */
1593 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc)
1595 struct sctp_chunk *ack;
1596 struct sctp_chunk *tmp;
1598 /* We can remove all the entries from the queue upto
1599 * the "Peer-Sequence-Number".
1601 list_for_each_entry_safe(ack, tmp, &asoc->asconf_ack_list,
1603 if (ack->subh.addip_hdr->serial ==
1604 htonl(asoc->peer.addip_serial))
1607 list_del_init(&ack->transmitted_list);
1608 sctp_chunk_free(ack);
1612 /* Find the ASCONF_ACK whose serial number matches ASCONF */
1613 struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
1614 const struct sctp_association *asoc,
1617 struct sctp_chunk *ack;
1619 /* Walk through the list of cached ASCONF-ACKs and find the
1620 * ack chunk whose serial number matches that of the request.
1622 list_for_each_entry(ack, &asoc->asconf_ack_list, transmitted_list) {
1623 if (ack->subh.addip_hdr->serial == serial) {
1624 sctp_chunk_hold(ack);