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);
67 /* 1st Level Abstractions. */
69 /* Initialize a new association from provided memory. */
70 static struct sctp_association *sctp_association_init(struct sctp_association *asoc,
71 const struct sctp_endpoint *ep,
72 const struct sock *sk,
81 /* Retrieve the SCTP per socket area. */
82 sp = sctp_sk((struct sock *)sk);
84 /* Init all variables to a known value. */
85 memset(asoc, 0, sizeof(struct sctp_association));
87 /* Discarding const is appropriate here. */
88 asoc->ep = (struct sctp_endpoint *)ep;
89 sctp_endpoint_hold(asoc->ep);
92 asoc->base.sk = (struct sock *)sk;
93 sock_hold(asoc->base.sk);
95 /* Initialize the common base substructure. */
96 asoc->base.type = SCTP_EP_TYPE_ASSOCIATION;
98 /* Initialize the object handling fields. */
99 atomic_set(&asoc->base.refcnt, 1);
101 asoc->base.malloced = 0;
103 /* Initialize the bind addr area. */
104 sctp_bind_addr_init(&asoc->base.bind_addr, ep->base.bind_addr.port);
106 asoc->state = SCTP_STATE_CLOSED;
108 /* Set these values from the socket values, a conversion between
109 * millsecons to seconds/microseconds must also be done.
111 asoc->cookie_life.tv_sec = sp->assocparams.sasoc_cookie_life / 1000;
112 asoc->cookie_life.tv_usec = (sp->assocparams.sasoc_cookie_life % 1000)
114 asoc->frag_point = 0;
116 /* Set the association max_retrans and RTO values from the
119 asoc->max_retrans = sp->assocparams.sasoc_asocmaxrxt;
120 asoc->rto_initial = msecs_to_jiffies(sp->rtoinfo.srto_initial);
121 asoc->rto_max = msecs_to_jiffies(sp->rtoinfo.srto_max);
122 asoc->rto_min = msecs_to_jiffies(sp->rtoinfo.srto_min);
124 asoc->overall_error_count = 0;
126 /* Initialize the association's heartbeat interval based on the
127 * sock configured value.
129 asoc->hbinterval = msecs_to_jiffies(sp->hbinterval);
131 /* Initialize path max retrans value. */
132 asoc->pathmaxrxt = sp->pathmaxrxt;
134 /* Initialize default path MTU. */
135 asoc->pathmtu = sp->pathmtu;
137 /* Set association default SACK delay */
138 asoc->sackdelay = msecs_to_jiffies(sp->sackdelay);
140 /* Set the association default flags controlling
141 * Heartbeat, SACK delay, and Path MTU Discovery.
143 asoc->param_flags = sp->param_flags;
145 /* Initialize the maximum mumber of new data packets that can be sent
148 asoc->max_burst = sp->max_burst;
150 /* initialize association timers */
151 asoc->timeouts[SCTP_EVENT_TIMEOUT_NONE] = 0;
152 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] = asoc->rto_initial;
153 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] = asoc->rto_initial;
154 asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = asoc->rto_initial;
155 asoc->timeouts[SCTP_EVENT_TIMEOUT_T3_RTX] = 0;
156 asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = 0;
158 /* sctpimpguide Section 2.12.2
159 * If the 'T5-shutdown-guard' timer is used, it SHOULD be set to the
160 * recommended value of 5 times 'RTO.Max'.
162 asoc->timeouts[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD]
165 asoc->timeouts[SCTP_EVENT_TIMEOUT_HEARTBEAT] = 0;
166 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] = asoc->sackdelay;
167 asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE] =
170 /* Initilizes the timers */
171 for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i)
172 setup_timer(&asoc->timers[i], sctp_timer_events[i],
173 (unsigned long)asoc);
175 /* Pull default initialization values from the sock options.
176 * Note: This assumes that the values have already been
177 * validated in the sock.
179 asoc->c.sinit_max_instreams = sp->initmsg.sinit_max_instreams;
180 asoc->c.sinit_num_ostreams = sp->initmsg.sinit_num_ostreams;
181 asoc->max_init_attempts = sp->initmsg.sinit_max_attempts;
183 asoc->max_init_timeo =
184 msecs_to_jiffies(sp->initmsg.sinit_max_init_timeo);
186 /* Allocate storage for the ssnmap after the inbound and outbound
187 * streams have been negotiated during Init.
191 /* Set the local window size for receive.
192 * This is also the rcvbuf space per association.
193 * RFC 6 - A SCTP receiver MUST be able to receive a minimum of
194 * 1500 bytes in one SCTP packet.
196 if ((sk->sk_rcvbuf/2) < SCTP_DEFAULT_MINWINDOW)
197 asoc->rwnd = SCTP_DEFAULT_MINWINDOW;
199 asoc->rwnd = sk->sk_rcvbuf/2;
201 asoc->a_rwnd = asoc->rwnd;
205 /* Use my own max window until I learn something better. */
206 asoc->peer.rwnd = SCTP_DEFAULT_MAXWINDOW;
208 /* Set the sndbuf size for transmit. */
209 asoc->sndbuf_used = 0;
211 /* Initialize the receive memory counter */
212 atomic_set(&asoc->rmem_alloc, 0);
214 init_waitqueue_head(&asoc->wait);
216 asoc->c.my_vtag = sctp_generate_tag(ep);
217 asoc->peer.i.init_tag = 0; /* INIT needs a vtag of 0. */
218 asoc->c.peer_vtag = 0;
220 asoc->c.peer_ttag = 0;
221 asoc->c.my_port = ep->base.bind_addr.port;
223 asoc->c.initial_tsn = sctp_generate_tsn(ep);
225 asoc->next_tsn = asoc->c.initial_tsn;
227 asoc->ctsn_ack_point = asoc->next_tsn - 1;
228 asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
229 asoc->highest_sacked = asoc->ctsn_ack_point;
230 asoc->last_cwr_tsn = asoc->ctsn_ack_point;
231 asoc->unack_data = 0;
233 /* ADDIP Section 4.1 Asconf Chunk Procedures
235 * When an endpoint has an ASCONF signaled change to be sent to the
236 * remote endpoint it should do the following:
238 * A2) a serial number should be assigned to the chunk. The serial
239 * number SHOULD be a monotonically increasing number. The serial
240 * numbers SHOULD be initialized at the start of the
241 * association to the same value as the initial TSN.
243 asoc->addip_serial = asoc->c.initial_tsn;
245 INIT_LIST_HEAD(&asoc->addip_chunk_list);
246 INIT_LIST_HEAD(&asoc->asconf_ack_list);
248 /* Make an empty list of remote transport addresses. */
249 INIT_LIST_HEAD(&asoc->peer.transport_addr_list);
250 asoc->peer.transport_count = 0;
252 /* RFC 2960 5.1 Normal Establishment of an Association
254 * After the reception of the first data chunk in an
255 * association the endpoint must immediately respond with a
256 * sack to acknowledge the data chunk. Subsequent
257 * acknowledgements should be done as described in Section
260 * [We implement this by telling a new association that it
261 * already received one packet.]
263 asoc->peer.sack_needed = 1;
265 /* Assume that the peer will tell us if he recognizes ASCONF
266 * as part of INIT exchange.
267 * The sctp_addip_noauth option is there for backward compatibilty
268 * and will revert old behavior.
270 asoc->peer.asconf_capable = 0;
271 if (sctp_addip_noauth)
272 asoc->peer.asconf_capable = 1;
274 /* Create an input queue. */
275 sctp_inq_init(&asoc->base.inqueue);
276 sctp_inq_set_th_handler(&asoc->base.inqueue, sctp_assoc_bh_rcv);
278 /* Create an output queue. */
279 sctp_outq_init(asoc, &asoc->outqueue);
281 if (!sctp_ulpq_init(&asoc->ulpq, asoc))
284 /* Set up the tsn tracking. */
285 sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_SIZE, 0);
291 /* Assume that peer would support both address types unless we are
294 asoc->peer.ipv4_address = 1;
295 asoc->peer.ipv6_address = 1;
296 INIT_LIST_HEAD(&asoc->asocs);
298 asoc->autoclose = sp->autoclose;
300 asoc->default_stream = sp->default_stream;
301 asoc->default_ppid = sp->default_ppid;
302 asoc->default_flags = sp->default_flags;
303 asoc->default_context = sp->default_context;
304 asoc->default_timetolive = sp->default_timetolive;
305 asoc->default_rcv_context = sp->default_rcv_context;
307 /* AUTH related initializations */
308 INIT_LIST_HEAD(&asoc->endpoint_shared_keys);
309 err = sctp_auth_asoc_copy_shkeys(ep, asoc, gfp);
313 asoc->active_key_id = ep->active_key_id;
314 asoc->asoc_shared_key = NULL;
316 asoc->default_hmac_id = 0;
317 /* Save the hmacs and chunks list into this association */
318 if (ep->auth_hmacs_list)
319 memcpy(asoc->c.auth_hmacs, ep->auth_hmacs_list,
320 ntohs(ep->auth_hmacs_list->param_hdr.length));
321 if (ep->auth_chunk_list)
322 memcpy(asoc->c.auth_chunks, ep->auth_chunk_list,
323 ntohs(ep->auth_chunk_list->param_hdr.length));
325 /* Get the AUTH random number for this association */
326 p = (sctp_paramhdr_t *)asoc->c.auth_random;
327 p->type = SCTP_PARAM_RANDOM;
328 p->length = htons(sizeof(sctp_paramhdr_t) + SCTP_AUTH_RANDOM_LENGTH);
329 get_random_bytes(p+1, SCTP_AUTH_RANDOM_LENGTH);
334 sctp_endpoint_put(asoc->ep);
335 sock_put(asoc->base.sk);
339 /* Allocate and initialize a new association */
340 struct sctp_association *sctp_association_new(const struct sctp_endpoint *ep,
341 const struct sock *sk,
345 struct sctp_association *asoc;
347 asoc = t_new(struct sctp_association, gfp);
351 if (!sctp_association_init(asoc, ep, sk, scope, gfp))
354 asoc->base.malloced = 1;
355 SCTP_DBG_OBJCNT_INC(assoc);
356 SCTP_DEBUG_PRINTK("Created asoc %p\n", asoc);
366 /* Free this association if possible. There may still be users, so
367 * the actual deallocation may be delayed.
369 void sctp_association_free(struct sctp_association *asoc)
371 struct sock *sk = asoc->base.sk;
372 struct sctp_transport *transport;
373 struct list_head *pos, *temp;
376 /* Only real associations count against the endpoint, so
377 * don't bother for if this is a temporary association.
380 list_del(&asoc->asocs);
382 /* Decrement the backlog value for a TCP-style listening
385 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
386 sk->sk_ack_backlog--;
389 /* Mark as dead, so other users can know this structure is
394 /* Dispose of any data lying around in the outqueue. */
395 sctp_outq_free(&asoc->outqueue);
397 /* Dispose of any pending messages for the upper layer. */
398 sctp_ulpq_free(&asoc->ulpq);
400 /* Dispose of any pending chunks on the inqueue. */
401 sctp_inq_free(&asoc->base.inqueue);
403 /* Free ssnmap storage. */
404 sctp_ssnmap_free(asoc->ssnmap);
406 /* Clean up the bound address list. */
407 sctp_bind_addr_free(&asoc->base.bind_addr);
409 /* Do we need to go through all of our timers and
410 * delete them? To be safe we will try to delete all, but we
411 * should be able to go through and make a guess based
414 for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i) {
415 if (timer_pending(&asoc->timers[i]) &&
416 del_timer(&asoc->timers[i]))
417 sctp_association_put(asoc);
420 /* Free peer's cached cookie. */
421 kfree(asoc->peer.cookie);
422 kfree(asoc->peer.peer_random);
423 kfree(asoc->peer.peer_chunks);
424 kfree(asoc->peer.peer_hmacs);
426 /* Release the transport structures. */
427 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
428 transport = list_entry(pos, struct sctp_transport, transports);
430 sctp_transport_free(transport);
433 asoc->peer.transport_count = 0;
435 /* Free any cached ASCONF_ACK chunk. */
436 sctp_assoc_free_asconf_acks(asoc);
438 /* Free any cached ASCONF chunk. */
439 if (asoc->addip_last_asconf)
440 sctp_chunk_free(asoc->addip_last_asconf);
442 /* AUTH - Free the endpoint shared keys */
443 sctp_auth_destroy_keys(&asoc->endpoint_shared_keys);
445 /* AUTH - Free the association shared key */
446 sctp_auth_key_put(asoc->asoc_shared_key);
448 sctp_association_put(asoc);
451 /* Cleanup and free up an association. */
452 static void sctp_association_destroy(struct sctp_association *asoc)
454 SCTP_ASSERT(asoc->base.dead, "Assoc is not dead", return);
456 sctp_endpoint_put(asoc->ep);
457 sock_put(asoc->base.sk);
459 if (asoc->assoc_id != 0) {
460 spin_lock_bh(&sctp_assocs_id_lock);
461 idr_remove(&sctp_assocs_id, asoc->assoc_id);
462 spin_unlock_bh(&sctp_assocs_id_lock);
465 BUG_TRAP(!atomic_read(&asoc->rmem_alloc));
467 if (asoc->base.malloced) {
469 SCTP_DBG_OBJCNT_DEC(assoc);
473 /* Change the primary destination address for the peer. */
474 void sctp_assoc_set_primary(struct sctp_association *asoc,
475 struct sctp_transport *transport)
479 /* it's a changeover only if we already have a primary path
480 * that we are changing
482 if (asoc->peer.primary_path != NULL &&
483 asoc->peer.primary_path != transport)
486 asoc->peer.primary_path = transport;
488 /* Set a default msg_name for events. */
489 memcpy(&asoc->peer.primary_addr, &transport->ipaddr,
490 sizeof(union sctp_addr));
492 /* If the primary path is changing, assume that the
493 * user wants to use this new path.
495 if ((transport->state == SCTP_ACTIVE) ||
496 (transport->state == SCTP_UNKNOWN))
497 asoc->peer.active_path = transport;
500 * SFR-CACC algorithm:
501 * Upon the receipt of a request to change the primary
502 * destination address, on the data structure for the new
503 * primary destination, the sender MUST do the following:
505 * 1) If CHANGEOVER_ACTIVE is set, then there was a switch
506 * to this destination address earlier. The sender MUST set
507 * CYCLING_CHANGEOVER to indicate that this switch is a
508 * double switch to the same destination address.
510 if (transport->cacc.changeover_active)
511 transport->cacc.cycling_changeover = changeover;
513 /* 2) The sender MUST set CHANGEOVER_ACTIVE to indicate that
514 * a changeover has occurred.
516 transport->cacc.changeover_active = changeover;
518 /* 3) The sender MUST store the next TSN to be sent in
519 * next_tsn_at_change.
521 transport->cacc.next_tsn_at_change = asoc->next_tsn;
524 /* Remove a transport from an association. */
525 void sctp_assoc_rm_peer(struct sctp_association *asoc,
526 struct sctp_transport *peer)
528 struct list_head *pos;
529 struct sctp_transport *transport;
531 SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_rm_peer:association %p addr: ",
535 ntohs(peer->ipaddr.v4.sin_port));
537 /* If we are to remove the current retran_path, update it
538 * to the next peer before removing this peer from the list.
540 if (asoc->peer.retran_path == peer)
541 sctp_assoc_update_retran_path(asoc);
543 /* Remove this peer from the list. */
544 list_del(&peer->transports);
546 /* Get the first transport of asoc. */
547 pos = asoc->peer.transport_addr_list.next;
548 transport = list_entry(pos, struct sctp_transport, transports);
550 /* Update any entries that match the peer to be deleted. */
551 if (asoc->peer.primary_path == peer)
552 sctp_assoc_set_primary(asoc, transport);
553 if (asoc->peer.active_path == peer)
554 asoc->peer.active_path = transport;
555 if (asoc->peer.last_data_from == peer)
556 asoc->peer.last_data_from = transport;
558 /* If we remove the transport an INIT was last sent to, set it to
559 * NULL. Combined with the update of the retran path above, this
560 * will cause the next INIT to be sent to the next available
561 * transport, maintaining the cycle.
563 if (asoc->init_last_sent_to == peer)
564 asoc->init_last_sent_to = NULL;
566 asoc->peer.transport_count--;
568 sctp_transport_free(peer);
571 /* Add a transport address to an association. */
572 struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc,
573 const union sctp_addr *addr,
575 const int peer_state)
577 struct sctp_transport *peer;
578 struct sctp_sock *sp;
581 sp = sctp_sk(asoc->base.sk);
583 /* AF_INET and AF_INET6 share common port field. */
584 port = ntohs(addr->v4.sin_port);
586 SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_add_peer:association %p addr: ",
587 " port: %d state:%d\n",
593 /* Set the port if it has not been set yet. */
594 if (0 == asoc->peer.port)
595 asoc->peer.port = port;
597 /* Check to see if this is a duplicate. */
598 peer = sctp_assoc_lookup_paddr(asoc, addr);
600 if (peer->state == SCTP_UNKNOWN) {
601 if (peer_state == SCTP_ACTIVE)
602 peer->state = SCTP_ACTIVE;
603 if (peer_state == SCTP_UNCONFIRMED)
604 peer->state = SCTP_UNCONFIRMED;
609 peer = sctp_transport_new(addr, gfp);
613 sctp_transport_set_owner(peer, asoc);
615 /* Initialize the peer's heartbeat interval based on the
616 * association configured value.
618 peer->hbinterval = asoc->hbinterval;
620 /* Set the path max_retrans. */
621 peer->pathmaxrxt = asoc->pathmaxrxt;
623 /* Initialize the peer's SACK delay timeout based on the
624 * association configured value.
626 peer->sackdelay = asoc->sackdelay;
628 /* Enable/disable heartbeat, SACK delay, and path MTU discovery
629 * based on association setting.
631 peer->param_flags = asoc->param_flags;
633 /* Initialize the pmtu of the transport. */
634 if (peer->param_flags & SPP_PMTUD_ENABLE)
635 sctp_transport_pmtu(peer);
636 else if (asoc->pathmtu)
637 peer->pathmtu = asoc->pathmtu;
639 peer->pathmtu = SCTP_DEFAULT_MAXSEGMENT;
641 /* If this is the first transport addr on this association,
642 * initialize the association PMTU to the peer's PMTU.
643 * If not and the current association PMTU is higher than the new
644 * peer's PMTU, reset the association PMTU to the new peer's PMTU.
647 asoc->pathmtu = min_t(int, peer->pathmtu, asoc->pathmtu);
649 asoc->pathmtu = peer->pathmtu;
651 SCTP_DEBUG_PRINTK("sctp_assoc_add_peer:association %p PMTU set to "
652 "%d\n", asoc, asoc->pathmtu);
654 asoc->frag_point = sctp_frag_point(sp, asoc->pathmtu);
656 /* The asoc->peer.port might not be meaningful yet, but
657 * initialize the packet structure anyway.
659 sctp_packet_init(&peer->packet, peer, asoc->base.bind_addr.port,
664 * o The initial cwnd before DATA transmission or after a sufficiently
665 * long idle period MUST be set to
666 * min(4*MTU, max(2*MTU, 4380 bytes))
668 * o The initial value of ssthresh MAY be arbitrarily high
669 * (for example, implementations MAY use the size of the
670 * receiver advertised window).
672 peer->cwnd = min(4*asoc->pathmtu, max_t(__u32, 2*asoc->pathmtu, 4380));
674 /* At this point, we may not have the receiver's advertised window,
675 * so initialize ssthresh to the default value and it will be set
676 * later when we process the INIT.
678 peer->ssthresh = SCTP_DEFAULT_MAXWINDOW;
680 peer->partial_bytes_acked = 0;
681 peer->flight_size = 0;
683 /* Set the transport's RTO.initial value */
684 peer->rto = asoc->rto_initial;
686 /* Set the peer's active state. */
687 peer->state = peer_state;
689 /* Attach the remote transport to our asoc. */
690 list_add_tail(&peer->transports, &asoc->peer.transport_addr_list);
691 asoc->peer.transport_count++;
693 /* If we do not yet have a primary path, set one. */
694 if (!asoc->peer.primary_path) {
695 sctp_assoc_set_primary(asoc, peer);
696 asoc->peer.retran_path = peer;
699 if (asoc->peer.active_path == asoc->peer.retran_path) {
700 asoc->peer.retran_path = peer;
706 /* Delete a transport address from an association. */
707 void sctp_assoc_del_peer(struct sctp_association *asoc,
708 const union sctp_addr *addr)
710 struct list_head *pos;
711 struct list_head *temp;
712 struct sctp_transport *transport;
714 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
715 transport = list_entry(pos, struct sctp_transport, transports);
716 if (sctp_cmp_addr_exact(addr, &transport->ipaddr)) {
717 /* Do book keeping for removing the peer and free it. */
718 sctp_assoc_rm_peer(asoc, transport);
724 /* Lookup a transport by address. */
725 struct sctp_transport *sctp_assoc_lookup_paddr(
726 const struct sctp_association *asoc,
727 const union sctp_addr *address)
729 struct sctp_transport *t;
731 /* Cycle through all transports searching for a peer address. */
733 list_for_each_entry(t, &asoc->peer.transport_addr_list,
735 if (sctp_cmp_addr_exact(address, &t->ipaddr))
742 /* Remove all transports except a give one */
743 void sctp_assoc_del_nonprimary_peers(struct sctp_association *asoc,
744 struct sctp_transport *primary)
746 struct sctp_transport *temp;
747 struct sctp_transport *t;
749 list_for_each_entry_safe(t, temp, &asoc->peer.transport_addr_list,
751 /* if the current transport is not the primary one, delete it */
753 sctp_assoc_rm_peer(asoc, t);
759 /* Engage in transport control operations.
760 * Mark the transport up or down and send a notification to the user.
761 * Select and update the new active and retran paths.
763 void sctp_assoc_control_transport(struct sctp_association *asoc,
764 struct sctp_transport *transport,
765 sctp_transport_cmd_t command,
766 sctp_sn_error_t error)
768 struct sctp_transport *t = NULL;
769 struct sctp_transport *first;
770 struct sctp_transport *second;
771 struct sctp_ulpevent *event;
772 struct sockaddr_storage addr;
775 /* Record the transition on the transport. */
777 case SCTP_TRANSPORT_UP:
778 /* If we are moving from UNCONFIRMED state due
779 * to heartbeat success, report the SCTP_ADDR_CONFIRMED
780 * state to the user, otherwise report SCTP_ADDR_AVAILABLE.
782 if (SCTP_UNCONFIRMED == transport->state &&
783 SCTP_HEARTBEAT_SUCCESS == error)
784 spc_state = SCTP_ADDR_CONFIRMED;
786 spc_state = SCTP_ADDR_AVAILABLE;
787 transport->state = SCTP_ACTIVE;
790 case SCTP_TRANSPORT_DOWN:
791 /* if the transort was never confirmed, do not transition it
794 if (transport->state != SCTP_UNCONFIRMED)
795 transport->state = SCTP_INACTIVE;
797 spc_state = SCTP_ADDR_UNREACHABLE;
804 /* Generate and send a SCTP_PEER_ADDR_CHANGE notification to the
807 memset(&addr, 0, sizeof(struct sockaddr_storage));
808 memcpy(&addr, &transport->ipaddr, transport->af_specific->sockaddr_len);
809 event = sctp_ulpevent_make_peer_addr_change(asoc, &addr,
810 0, spc_state, error, GFP_ATOMIC);
812 sctp_ulpq_tail_event(&asoc->ulpq, event);
814 /* Select new active and retran paths. */
816 /* Look for the two most recently used active transports.
818 * This code produces the wrong ordering whenever jiffies
819 * rolls over, but we still get usable transports, so we don't
822 first = NULL; second = NULL;
824 list_for_each_entry(t, &asoc->peer.transport_addr_list,
827 if ((t->state == SCTP_INACTIVE) ||
828 (t->state == SCTP_UNCONFIRMED))
830 if (!first || t->last_time_heard > first->last_time_heard) {
834 if (!second || t->last_time_heard > second->last_time_heard)
838 /* RFC 2960 6.4 Multi-Homed SCTP Endpoints
840 * By default, an endpoint should always transmit to the
841 * primary path, unless the SCTP user explicitly specifies the
842 * destination transport address (and possibly source
843 * transport address) to use.
845 * [If the primary is active but not most recent, bump the most
846 * recently used transport.]
848 if (((asoc->peer.primary_path->state == SCTP_ACTIVE) ||
849 (asoc->peer.primary_path->state == SCTP_UNKNOWN)) &&
850 first != asoc->peer.primary_path) {
852 first = asoc->peer.primary_path;
855 /* If we failed to find a usable transport, just camp on the
856 * primary, even if it is inactive.
859 first = asoc->peer.primary_path;
860 second = asoc->peer.primary_path;
863 /* Set the active and retran transports. */
864 asoc->peer.active_path = first;
865 asoc->peer.retran_path = second;
868 /* Hold a reference to an association. */
869 void sctp_association_hold(struct sctp_association *asoc)
871 atomic_inc(&asoc->base.refcnt);
874 /* Release a reference to an association and cleanup
875 * if there are no more references.
877 void sctp_association_put(struct sctp_association *asoc)
879 if (atomic_dec_and_test(&asoc->base.refcnt))
880 sctp_association_destroy(asoc);
883 /* Allocate the next TSN, Transmission Sequence Number, for the given
886 __u32 sctp_association_get_next_tsn(struct sctp_association *asoc)
888 /* From Section 1.6 Serial Number Arithmetic:
889 * Transmission Sequence Numbers wrap around when they reach
890 * 2**32 - 1. That is, the next TSN a DATA chunk MUST use
891 * after transmitting TSN = 2*32 - 1 is TSN = 0.
893 __u32 retval = asoc->next_tsn;
900 /* Compare two addresses to see if they match. Wildcard addresses
901 * only match themselves.
903 int sctp_cmp_addr_exact(const union sctp_addr *ss1,
904 const union sctp_addr *ss2)
908 af = sctp_get_af_specific(ss1->sa.sa_family);
912 return af->cmp_addr(ss1, ss2);
915 /* Return an ecne chunk to get prepended to a packet.
916 * Note: We are sly and return a shared, prealloced chunk. FIXME:
917 * No we don't, but we could/should.
919 struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc)
921 struct sctp_chunk *chunk;
923 /* Send ECNE if needed.
924 * Not being able to allocate a chunk here is not deadly.
927 chunk = sctp_make_ecne(asoc, asoc->last_ecne_tsn);
935 * Find which transport this TSN was sent on.
937 struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *asoc,
940 struct sctp_transport *active;
941 struct sctp_transport *match;
942 struct sctp_transport *transport;
943 struct sctp_chunk *chunk;
944 __be32 key = htonl(tsn);
949 * FIXME: In general, find a more efficient data structure for
954 * The general strategy is to search each transport's transmitted
955 * list. Return which transport this TSN lives on.
957 * Let's be hopeful and check the active_path first.
958 * Another optimization would be to know if there is only one
959 * outbound path and not have to look for the TSN at all.
963 active = asoc->peer.active_path;
965 list_for_each_entry(chunk, &active->transmitted,
968 if (key == chunk->subh.data_hdr->tsn) {
974 /* If not found, go search all the other transports. */
975 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
978 if (transport == active)
980 list_for_each_entry(chunk, &transport->transmitted,
982 if (key == chunk->subh.data_hdr->tsn) {
992 /* Is this the association we are looking for? */
993 struct sctp_transport *sctp_assoc_is_match(struct sctp_association *asoc,
994 const union sctp_addr *laddr,
995 const union sctp_addr *paddr)
997 struct sctp_transport *transport;
999 if ((htons(asoc->base.bind_addr.port) == laddr->v4.sin_port) &&
1000 (htons(asoc->peer.port) == paddr->v4.sin_port)) {
1001 transport = sctp_assoc_lookup_paddr(asoc, paddr);
1005 if (sctp_bind_addr_match(&asoc->base.bind_addr, laddr,
1006 sctp_sk(asoc->base.sk)))
1015 /* Do delayed input processing. This is scheduled by sctp_rcv(). */
1016 static void sctp_assoc_bh_rcv(struct work_struct *work)
1018 struct sctp_association *asoc =
1019 container_of(work, struct sctp_association,
1020 base.inqueue.immediate);
1021 struct sctp_endpoint *ep;
1022 struct sctp_chunk *chunk;
1024 struct sctp_inq *inqueue;
1026 sctp_subtype_t subtype;
1029 /* The association should be held so we should be safe. */
1033 inqueue = &asoc->base.inqueue;
1034 sctp_association_hold(asoc);
1035 while (NULL != (chunk = sctp_inq_pop(inqueue))) {
1036 state = asoc->state;
1037 subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type);
1039 /* SCTP-AUTH, Section 6.3:
1040 * The receiver has a list of chunk types which it expects
1041 * to be received only after an AUTH-chunk. This list has
1042 * been sent to the peer during the association setup. It
1043 * MUST silently discard these chunks if they are not placed
1044 * after an AUTH chunk in the packet.
1046 if (sctp_auth_recv_cid(subtype.chunk, asoc) && !chunk->auth)
1049 /* Remember where the last DATA chunk came from so we
1050 * know where to send the SACK.
1052 if (sctp_chunk_is_data(chunk))
1053 asoc->peer.last_data_from = chunk->transport;
1055 SCTP_INC_STATS(SCTP_MIB_INCTRLCHUNKS);
1057 if (chunk->transport)
1058 chunk->transport->last_time_heard = jiffies;
1060 /* Run through the state machine. */
1061 error = sctp_do_sm(SCTP_EVENT_T_CHUNK, subtype,
1062 state, ep, asoc, chunk, GFP_ATOMIC);
1064 /* Check to see if the association is freed in response to
1065 * the incoming chunk. If so, get out of the while loop.
1067 if (asoc->base.dead)
1070 /* If there is an error on chunk, discard this packet. */
1072 chunk->pdiscard = 1;
1074 sctp_association_put(asoc);
1077 /* This routine moves an association from its old sk to a new sk. */
1078 void sctp_assoc_migrate(struct sctp_association *assoc, struct sock *newsk)
1080 struct sctp_sock *newsp = sctp_sk(newsk);
1081 struct sock *oldsk = assoc->base.sk;
1083 /* Delete the association from the old endpoint's list of
1086 list_del_init(&assoc->asocs);
1088 /* Decrement the backlog value for a TCP-style socket. */
1089 if (sctp_style(oldsk, TCP))
1090 oldsk->sk_ack_backlog--;
1092 /* Release references to the old endpoint and the sock. */
1093 sctp_endpoint_put(assoc->ep);
1094 sock_put(assoc->base.sk);
1096 /* Get a reference to the new endpoint. */
1097 assoc->ep = newsp->ep;
1098 sctp_endpoint_hold(assoc->ep);
1100 /* Get a reference to the new sock. */
1101 assoc->base.sk = newsk;
1102 sock_hold(assoc->base.sk);
1104 /* Add the association to the new endpoint's list of associations. */
1105 sctp_endpoint_add_asoc(newsp->ep, assoc);
1108 /* Update an association (possibly from unexpected COOKIE-ECHO processing). */
1109 void sctp_assoc_update(struct sctp_association *asoc,
1110 struct sctp_association *new)
1112 struct sctp_transport *trans;
1113 struct list_head *pos, *temp;
1115 /* Copy in new parameters of peer. */
1117 asoc->peer.rwnd = new->peer.rwnd;
1118 asoc->peer.sack_needed = new->peer.sack_needed;
1119 asoc->peer.i = new->peer.i;
1120 sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_SIZE,
1121 asoc->peer.i.initial_tsn);
1123 /* Remove any peer addresses not present in the new association. */
1124 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
1125 trans = list_entry(pos, struct sctp_transport, transports);
1126 if (!sctp_assoc_lookup_paddr(new, &trans->ipaddr))
1127 sctp_assoc_del_peer(asoc, &trans->ipaddr);
1129 if (asoc->state >= SCTP_STATE_ESTABLISHED)
1130 sctp_transport_reset(trans);
1133 /* If the case is A (association restart), use
1134 * initial_tsn as next_tsn. If the case is B, use
1135 * current next_tsn in case data sent to peer
1136 * has been discarded and needs retransmission.
1138 if (asoc->state >= SCTP_STATE_ESTABLISHED) {
1139 asoc->next_tsn = new->next_tsn;
1140 asoc->ctsn_ack_point = new->ctsn_ack_point;
1141 asoc->adv_peer_ack_point = new->adv_peer_ack_point;
1143 /* Reinitialize SSN for both local streams
1144 * and peer's streams.
1146 sctp_ssnmap_clear(asoc->ssnmap);
1148 /* Flush the ULP reassembly and ordered queue.
1149 * Any data there will now be stale and will
1152 sctp_ulpq_flush(&asoc->ulpq);
1154 /* reset the overall association error count so
1155 * that the restarted association doesn't get torn
1156 * down on the next retransmission timer.
1158 asoc->overall_error_count = 0;
1161 /* Add any peer addresses from the new association. */
1162 list_for_each_entry(trans, &new->peer.transport_addr_list,
1164 if (!sctp_assoc_lookup_paddr(asoc, &trans->ipaddr))
1165 sctp_assoc_add_peer(asoc, &trans->ipaddr,
1166 GFP_ATOMIC, trans->state);
1169 asoc->ctsn_ack_point = asoc->next_tsn - 1;
1170 asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
1171 if (!asoc->ssnmap) {
1172 /* Move the ssnmap. */
1173 asoc->ssnmap = new->ssnmap;
1177 if (!asoc->assoc_id) {
1178 /* get a new association id since we don't have one
1181 sctp_assoc_set_id(asoc, GFP_ATOMIC);
1185 /* SCTP-AUTH: Save the peer parameters from the new assocaitions
1186 * and also move the association shared keys over
1188 kfree(asoc->peer.peer_random);
1189 asoc->peer.peer_random = new->peer.peer_random;
1190 new->peer.peer_random = NULL;
1192 kfree(asoc->peer.peer_chunks);
1193 asoc->peer.peer_chunks = new->peer.peer_chunks;
1194 new->peer.peer_chunks = NULL;
1196 kfree(asoc->peer.peer_hmacs);
1197 asoc->peer.peer_hmacs = new->peer.peer_hmacs;
1198 new->peer.peer_hmacs = NULL;
1200 sctp_auth_key_put(asoc->asoc_shared_key);
1201 sctp_auth_asoc_init_active_key(asoc, GFP_ATOMIC);
1204 /* Update the retran path for sending a retransmitted packet.
1205 * Round-robin through the active transports, else round-robin
1206 * through the inactive transports as this is the next best thing
1209 void sctp_assoc_update_retran_path(struct sctp_association *asoc)
1211 struct sctp_transport *t, *next;
1212 struct list_head *head = &asoc->peer.transport_addr_list;
1213 struct list_head *pos;
1215 if (asoc->peer.transport_count == 1)
1218 /* Find the next transport in a round-robin fashion. */
1219 t = asoc->peer.retran_path;
1220 pos = &t->transports;
1224 /* Skip the head. */
1225 if (pos->next == head)
1230 t = list_entry(pos, struct sctp_transport, transports);
1232 /* We have exhausted the list, but didn't find any
1233 * other active transports. If so, use the next
1236 if (t == asoc->peer.retran_path) {
1241 /* Try to find an active transport. */
1243 if ((t->state == SCTP_ACTIVE) ||
1244 (t->state == SCTP_UNKNOWN)) {
1247 /* Keep track of the next transport in case
1248 * we don't find any active transport.
1255 asoc->peer.retran_path = t;
1257 SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_update_retran_path:association"
1262 ntohs(t->ipaddr.v4.sin_port));
1265 /* Choose the transport for sending a INIT packet. */
1266 struct sctp_transport *sctp_assoc_choose_init_transport(
1267 struct sctp_association *asoc)
1269 struct sctp_transport *t;
1271 /* Use the retran path. If the last INIT was sent over the
1272 * retran path, update the retran path and use it.
1274 if (!asoc->init_last_sent_to) {
1275 t = asoc->peer.active_path;
1277 if (asoc->init_last_sent_to == asoc->peer.retran_path)
1278 sctp_assoc_update_retran_path(asoc);
1279 t = asoc->peer.retran_path;
1282 SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_update_retran_path:association"
1287 ntohs(t->ipaddr.v4.sin_port));
1292 /* Choose the transport for sending a SHUTDOWN packet. */
1293 struct sctp_transport *sctp_assoc_choose_shutdown_transport(
1294 struct sctp_association *asoc)
1296 /* If this is the first time SHUTDOWN is sent, use the active path,
1297 * else use the retran path. If the last SHUTDOWN was sent over the
1298 * retran path, update the retran path and use it.
1300 if (!asoc->shutdown_last_sent_to)
1301 return asoc->peer.active_path;
1303 if (asoc->shutdown_last_sent_to == asoc->peer.retran_path)
1304 sctp_assoc_update_retran_path(asoc);
1305 return asoc->peer.retran_path;
1310 /* Update the association's pmtu and frag_point by going through all the
1311 * transports. This routine is called when a transport's PMTU has changed.
1313 void sctp_assoc_sync_pmtu(struct sctp_association *asoc)
1315 struct sctp_transport *t;
1321 /* Get the lowest pmtu of all the transports. */
1322 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1324 if (t->pmtu_pending && t->dst) {
1325 sctp_transport_update_pmtu(t, dst_mtu(t->dst));
1326 t->pmtu_pending = 0;
1328 if (!pmtu || (t->pathmtu < pmtu))
1333 struct sctp_sock *sp = sctp_sk(asoc->base.sk);
1334 asoc->pathmtu = pmtu;
1335 asoc->frag_point = sctp_frag_point(sp, pmtu);
1338 SCTP_DEBUG_PRINTK("%s: asoc:%p, pmtu:%d, frag_point:%d\n",
1339 __func__, asoc, asoc->pathmtu, asoc->frag_point);
1342 /* Should we send a SACK to update our peer? */
1343 static inline int sctp_peer_needs_update(struct sctp_association *asoc)
1345 switch (asoc->state) {
1346 case SCTP_STATE_ESTABLISHED:
1347 case SCTP_STATE_SHUTDOWN_PENDING:
1348 case SCTP_STATE_SHUTDOWN_RECEIVED:
1349 case SCTP_STATE_SHUTDOWN_SENT:
1350 if ((asoc->rwnd > asoc->a_rwnd) &&
1351 ((asoc->rwnd - asoc->a_rwnd) >=
1352 min_t(__u32, (asoc->base.sk->sk_rcvbuf >> 1), asoc->pathmtu)))
1361 /* Increase asoc's rwnd by len and send any window update SACK if needed. */
1362 void sctp_assoc_rwnd_increase(struct sctp_association *asoc, unsigned len)
1364 struct sctp_chunk *sack;
1365 struct timer_list *timer;
1367 if (asoc->rwnd_over) {
1368 if (asoc->rwnd_over >= len) {
1369 asoc->rwnd_over -= len;
1371 asoc->rwnd += (len - asoc->rwnd_over);
1372 asoc->rwnd_over = 0;
1378 SCTP_DEBUG_PRINTK("%s: asoc %p rwnd increased by %d to (%u, %u) "
1379 "- %u\n", __func__, asoc, len, asoc->rwnd,
1380 asoc->rwnd_over, asoc->a_rwnd);
1382 /* Send a window update SACK if the rwnd has increased by at least the
1383 * minimum of the association's PMTU and half of the receive buffer.
1384 * The algorithm used is similar to the one described in
1385 * Section 4.2.3.3 of RFC 1122.
1387 if (sctp_peer_needs_update(asoc)) {
1388 asoc->a_rwnd = asoc->rwnd;
1389 SCTP_DEBUG_PRINTK("%s: Sending window update SACK- asoc: %p "
1390 "rwnd: %u a_rwnd: %u\n", __func__,
1391 asoc, asoc->rwnd, asoc->a_rwnd);
1392 sack = sctp_make_sack(asoc);
1396 asoc->peer.sack_needed = 0;
1398 sctp_outq_tail(&asoc->outqueue, sack);
1400 /* Stop the SACK timer. */
1401 timer = &asoc->timers[SCTP_EVENT_TIMEOUT_SACK];
1402 if (timer_pending(timer) && del_timer(timer))
1403 sctp_association_put(asoc);
1407 /* Decrease asoc's rwnd by len. */
1408 void sctp_assoc_rwnd_decrease(struct sctp_association *asoc, unsigned len)
1410 SCTP_ASSERT(asoc->rwnd, "rwnd zero", return);
1411 SCTP_ASSERT(!asoc->rwnd_over, "rwnd_over not zero", return);
1412 if (asoc->rwnd >= len) {
1415 asoc->rwnd_over = len - asoc->rwnd;
1418 SCTP_DEBUG_PRINTK("%s: asoc %p rwnd decreased by %d to (%u, %u)\n",
1419 __func__, asoc, len, asoc->rwnd,
1423 /* Build the bind address list for the association based on info from the
1424 * local endpoint and the remote peer.
1426 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
1432 /* Use scoping rules to determine the subset of addresses from
1435 scope = sctp_scope(&asoc->peer.active_path->ipaddr);
1436 flags = (PF_INET6 == asoc->base.sk->sk_family) ? SCTP_ADDR6_ALLOWED : 0;
1437 if (asoc->peer.ipv4_address)
1438 flags |= SCTP_ADDR4_PEERSUPP;
1439 if (asoc->peer.ipv6_address)
1440 flags |= SCTP_ADDR6_PEERSUPP;
1442 return sctp_bind_addr_copy(&asoc->base.bind_addr,
1443 &asoc->ep->base.bind_addr,
1447 /* Build the association's bind address list from the cookie. */
1448 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *asoc,
1449 struct sctp_cookie *cookie,
1452 int var_size2 = ntohs(cookie->peer_init->chunk_hdr.length);
1453 int var_size3 = cookie->raw_addr_list_len;
1454 __u8 *raw = (__u8 *)cookie->peer_init + var_size2;
1456 return sctp_raw_to_bind_addrs(&asoc->base.bind_addr, raw, var_size3,
1457 asoc->ep->base.bind_addr.port, gfp);
1460 /* Lookup laddr in the bind address list of an association. */
1461 int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
1462 const union sctp_addr *laddr)
1466 if ((asoc->base.bind_addr.port == ntohs(laddr->v4.sin_port)) &&
1467 sctp_bind_addr_match(&asoc->base.bind_addr, laddr,
1468 sctp_sk(asoc->base.sk)))
1474 /* Set an association id for a given association */
1475 int sctp_assoc_set_id(struct sctp_association *asoc, gfp_t gfp)
1480 if (unlikely(!idr_pre_get(&sctp_assocs_id, gfp)))
1483 spin_lock_bh(&sctp_assocs_id_lock);
1484 error = idr_get_new_above(&sctp_assocs_id, (void *)asoc,
1486 spin_unlock_bh(&sctp_assocs_id_lock);
1487 if (error == -EAGAIN)
1492 asoc->assoc_id = (sctp_assoc_t) assoc_id;
1496 /* Free asconf_ack cache */
1497 static void sctp_assoc_free_asconf_acks(struct sctp_association *asoc)
1499 struct sctp_chunk *ack;
1500 struct sctp_chunk *tmp;
1502 list_for_each_entry_safe(ack, tmp, &asoc->asconf_ack_list,
1504 list_del_init(&ack->transmitted_list);
1505 sctp_chunk_free(ack);
1509 /* Clean up the ASCONF_ACK queue */
1510 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc)
1512 struct sctp_chunk *ack;
1513 struct sctp_chunk *tmp;
1515 /* We can remove all the entries from the queue upto
1516 * the "Peer-Sequence-Number".
1518 list_for_each_entry_safe(ack, tmp, &asoc->asconf_ack_list,
1520 if (ack->subh.addip_hdr->serial ==
1521 htonl(asoc->peer.addip_serial))
1524 list_del_init(&ack->transmitted_list);
1525 sctp_chunk_free(ack);
1529 /* Find the ASCONF_ACK whose serial number matches ASCONF */
1530 struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
1531 const struct sctp_association *asoc,
1534 struct sctp_chunk *ack;
1536 /* Walk through the list of cached ASCONF-ACKs and find the
1537 * ack chunk whose serial number matches that of the request.
1539 list_for_each_entry(ack, &asoc->asconf_ack_list, transmitted_list) {
1540 if (ack->subh.addip_hdr->serial == serial) {
1541 sctp_chunk_hold(ack);