1 /* SCTP kernel implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999-2000 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 * Copyright (c) 2001 Intel Corp.
6 * Copyright (c) 2001 La Monte H.P. Yarroll
8 * This file is part of the SCTP kernel implementation
10 * This module provides the abstraction for an SCTP association.
12 * This SCTP implementation is free software;
13 * you can redistribute it and/or modify it under the terms of
14 * the GNU General Public License as published by
15 * the Free Software Foundation; either version 2, or (at your option)
18 * This SCTP implementation is distributed in the hope that it
19 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
20 * ************************
21 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
22 * See the GNU General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with GNU CC; see the file COPYING. If not, see
26 * <http://www.gnu.org/licenses/>.
28 * Please send any bug reports or fixes you make to the
30 * lksctp developers <linux-sctp@vger.kernel.org>
32 * Written or modified by:
33 * La Monte H.P. Yarroll <piggy@acm.org>
34 * Karl Knutson <karl@athena.chicago.il.us>
35 * Jon Grimm <jgrimm@us.ibm.com>
36 * Xingang Guo <xingang.guo@intel.com>
37 * Hui Huang <hui.huang@nokia.com>
38 * Sridhar Samudrala <sri@us.ibm.com>
39 * Daisy Chang <daisyc@us.ibm.com>
40 * Ryan Layer <rmlayer@us.ibm.com>
41 * Kevin Gao <kevin.gao@intel.com>
44 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
46 #include <linux/types.h>
47 #include <linux/fcntl.h>
48 #include <linux/poll.h>
49 #include <linux/init.h>
51 #include <linux/slab.h>
54 #include <net/sctp/sctp.h>
55 #include <net/sctp/sm.h>
57 /* Forward declarations for internal functions. */
58 static void sctp_select_active_and_retran_path(struct sctp_association
*asoc
);
59 static void sctp_assoc_bh_rcv(struct work_struct
*work
);
60 static void sctp_assoc_free_asconf_acks(struct sctp_association
*asoc
);
61 static void sctp_assoc_free_asconf_queue(struct sctp_association
*asoc
);
63 /* 1st Level Abstractions. */
65 /* Initialize a new association from provided memory. */
66 static struct sctp_association
*sctp_association_init(struct sctp_association
*asoc
,
67 const struct sctp_endpoint
*ep
,
68 const struct sock
*sk
,
72 struct net
*net
= sock_net(sk
);
77 /* Retrieve the SCTP per socket area. */
78 sp
= sctp_sk((struct sock
*)sk
);
80 /* Discarding const is appropriate here. */
81 asoc
->ep
= (struct sctp_endpoint
*)ep
;
82 asoc
->base
.sk
= (struct sock
*)sk
;
84 sctp_endpoint_hold(asoc
->ep
);
85 sock_hold(asoc
->base
.sk
);
87 /* Initialize the common base substructure. */
88 asoc
->base
.type
= SCTP_EP_TYPE_ASSOCIATION
;
90 /* Initialize the object handling fields. */
91 atomic_set(&asoc
->base
.refcnt
, 1);
93 /* Initialize the bind addr area. */
94 sctp_bind_addr_init(&asoc
->base
.bind_addr
, ep
->base
.bind_addr
.port
);
96 asoc
->state
= SCTP_STATE_CLOSED
;
97 asoc
->cookie_life
= ms_to_ktime(sp
->assocparams
.sasoc_cookie_life
);
98 asoc
->user_frag
= sp
->user_frag
;
100 /* Set the association max_retrans and RTO values from the
103 asoc
->max_retrans
= sp
->assocparams
.sasoc_asocmaxrxt
;
104 asoc
->pf_retrans
= net
->sctp
.pf_retrans
;
106 asoc
->rto_initial
= msecs_to_jiffies(sp
->rtoinfo
.srto_initial
);
107 asoc
->rto_max
= msecs_to_jiffies(sp
->rtoinfo
.srto_max
);
108 asoc
->rto_min
= msecs_to_jiffies(sp
->rtoinfo
.srto_min
);
110 /* Initialize the association's heartbeat interval based on the
111 * sock configured value.
113 asoc
->hbinterval
= msecs_to_jiffies(sp
->hbinterval
);
115 /* Initialize path max retrans value. */
116 asoc
->pathmaxrxt
= sp
->pathmaxrxt
;
118 /* Initialize default path MTU. */
119 asoc
->pathmtu
= sp
->pathmtu
;
121 /* Set association default SACK delay */
122 asoc
->sackdelay
= msecs_to_jiffies(sp
->sackdelay
);
123 asoc
->sackfreq
= sp
->sackfreq
;
125 /* Set the association default flags controlling
126 * Heartbeat, SACK delay, and Path MTU Discovery.
128 asoc
->param_flags
= sp
->param_flags
;
130 /* Initialize the maximum number of new data packets that can be sent
133 asoc
->max_burst
= sp
->max_burst
;
135 /* initialize association timers */
136 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_T1_COOKIE
] = asoc
->rto_initial
;
137 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_T1_INIT
] = asoc
->rto_initial
;
138 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
] = asoc
->rto_initial
;
140 /* sctpimpguide Section 2.12.2
141 * If the 'T5-shutdown-guard' timer is used, it SHOULD be set to the
142 * recommended value of 5 times 'RTO.Max'.
144 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
]
147 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_SACK
] = asoc
->sackdelay
;
148 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_AUTOCLOSE
] = sp
->autoclose
* HZ
;
150 /* Initializes the timers */
151 for (i
= SCTP_EVENT_TIMEOUT_NONE
; i
< SCTP_NUM_TIMEOUT_TYPES
; ++i
)
152 setup_timer(&asoc
->timers
[i
], sctp_timer_events
[i
],
153 (unsigned long)asoc
);
155 /* Pull default initialization values from the sock options.
156 * Note: This assumes that the values have already been
157 * validated in the sock.
159 asoc
->c
.sinit_max_instreams
= sp
->initmsg
.sinit_max_instreams
;
160 asoc
->c
.sinit_num_ostreams
= sp
->initmsg
.sinit_num_ostreams
;
161 asoc
->max_init_attempts
= sp
->initmsg
.sinit_max_attempts
;
163 asoc
->max_init_timeo
=
164 msecs_to_jiffies(sp
->initmsg
.sinit_max_init_timeo
);
166 /* Set the local window size for receive.
167 * This is also the rcvbuf space per association.
168 * RFC 6 - A SCTP receiver MUST be able to receive a minimum of
169 * 1500 bytes in one SCTP packet.
171 if ((sk
->sk_rcvbuf
/2) < SCTP_DEFAULT_MINWINDOW
)
172 asoc
->rwnd
= SCTP_DEFAULT_MINWINDOW
;
174 asoc
->rwnd
= sk
->sk_rcvbuf
/2;
176 asoc
->a_rwnd
= asoc
->rwnd
;
178 /* Use my own max window until I learn something better. */
179 asoc
->peer
.rwnd
= SCTP_DEFAULT_MAXWINDOW
;
181 /* Initialize the receive memory counter */
182 atomic_set(&asoc
->rmem_alloc
, 0);
184 init_waitqueue_head(&asoc
->wait
);
186 asoc
->c
.my_vtag
= sctp_generate_tag(ep
);
187 asoc
->c
.my_port
= ep
->base
.bind_addr
.port
;
189 asoc
->c
.initial_tsn
= sctp_generate_tsn(ep
);
191 asoc
->next_tsn
= asoc
->c
.initial_tsn
;
193 asoc
->ctsn_ack_point
= asoc
->next_tsn
- 1;
194 asoc
->adv_peer_ack_point
= asoc
->ctsn_ack_point
;
195 asoc
->highest_sacked
= asoc
->ctsn_ack_point
;
196 asoc
->last_cwr_tsn
= asoc
->ctsn_ack_point
;
198 /* ADDIP Section 4.1 Asconf Chunk Procedures
200 * When an endpoint has an ASCONF signaled change to be sent to the
201 * remote endpoint it should do the following:
203 * A2) a serial number should be assigned to the chunk. The serial
204 * number SHOULD be a monotonically increasing number. The serial
205 * numbers SHOULD be initialized at the start of the
206 * association to the same value as the initial TSN.
208 asoc
->addip_serial
= asoc
->c
.initial_tsn
;
209 asoc
->strreset_outseq
= asoc
->c
.initial_tsn
;
211 INIT_LIST_HEAD(&asoc
->addip_chunk_list
);
212 INIT_LIST_HEAD(&asoc
->asconf_ack_list
);
214 /* Make an empty list of remote transport addresses. */
215 INIT_LIST_HEAD(&asoc
->peer
.transport_addr_list
);
217 /* RFC 2960 5.1 Normal Establishment of an Association
219 * After the reception of the first data chunk in an
220 * association the endpoint must immediately respond with a
221 * sack to acknowledge the data chunk. Subsequent
222 * acknowledgements should be done as described in Section
225 * [We implement this by telling a new association that it
226 * already received one packet.]
228 asoc
->peer
.sack_needed
= 1;
229 asoc
->peer
.sack_generation
= 1;
231 /* Assume that the peer will tell us if he recognizes ASCONF
232 * as part of INIT exchange.
233 * The sctp_addip_noauth option is there for backward compatibility
234 * and will revert old behavior.
236 if (net
->sctp
.addip_noauth
)
237 asoc
->peer
.asconf_capable
= 1;
239 /* Create an input queue. */
240 sctp_inq_init(&asoc
->base
.inqueue
);
241 sctp_inq_set_th_handler(&asoc
->base
.inqueue
, sctp_assoc_bh_rcv
);
243 /* Create an output queue. */
244 sctp_outq_init(asoc
, &asoc
->outqueue
);
246 if (!sctp_ulpq_init(&asoc
->ulpq
, asoc
))
249 /* Assume that peer would support both address types unless we are
252 asoc
->peer
.ipv4_address
= 1;
253 if (asoc
->base
.sk
->sk_family
== PF_INET6
)
254 asoc
->peer
.ipv6_address
= 1;
255 INIT_LIST_HEAD(&asoc
->asocs
);
257 asoc
->default_stream
= sp
->default_stream
;
258 asoc
->default_ppid
= sp
->default_ppid
;
259 asoc
->default_flags
= sp
->default_flags
;
260 asoc
->default_context
= sp
->default_context
;
261 asoc
->default_timetolive
= sp
->default_timetolive
;
262 asoc
->default_rcv_context
= sp
->default_rcv_context
;
264 /* AUTH related initializations */
265 INIT_LIST_HEAD(&asoc
->endpoint_shared_keys
);
266 if (sctp_auth_asoc_copy_shkeys(ep
, asoc
, gfp
))
269 asoc
->active_key_id
= ep
->active_key_id
;
270 asoc
->prsctp_enable
= ep
->prsctp_enable
;
271 asoc
->reconf_enable
= ep
->reconf_enable
;
272 asoc
->strreset_enable
= ep
->strreset_enable
;
274 /* Save the hmacs and chunks list into this association */
275 if (ep
->auth_hmacs_list
)
276 memcpy(asoc
->c
.auth_hmacs
, ep
->auth_hmacs_list
,
277 ntohs(ep
->auth_hmacs_list
->param_hdr
.length
));
278 if (ep
->auth_chunk_list
)
279 memcpy(asoc
->c
.auth_chunks
, ep
->auth_chunk_list
,
280 ntohs(ep
->auth_chunk_list
->param_hdr
.length
));
282 /* Get the AUTH random number for this association */
283 p
= (sctp_paramhdr_t
*)asoc
->c
.auth_random
;
284 p
->type
= SCTP_PARAM_RANDOM
;
285 p
->length
= htons(sizeof(sctp_paramhdr_t
) + SCTP_AUTH_RANDOM_LENGTH
);
286 get_random_bytes(p
+1, SCTP_AUTH_RANDOM_LENGTH
);
291 sock_put(asoc
->base
.sk
);
292 sctp_endpoint_put(asoc
->ep
);
296 /* Allocate and initialize a new association */
297 struct sctp_association
*sctp_association_new(const struct sctp_endpoint
*ep
,
298 const struct sock
*sk
,
302 struct sctp_association
*asoc
;
304 asoc
= kzalloc(sizeof(*asoc
), gfp
);
308 if (!sctp_association_init(asoc
, ep
, sk
, scope
, gfp
))
311 SCTP_DBG_OBJCNT_INC(assoc
);
313 pr_debug("Created asoc %p\n", asoc
);
323 /* Free this association if possible. There may still be users, so
324 * the actual deallocation may be delayed.
326 void sctp_association_free(struct sctp_association
*asoc
)
328 struct sock
*sk
= asoc
->base
.sk
;
329 struct sctp_transport
*transport
;
330 struct list_head
*pos
, *temp
;
333 /* Only real associations count against the endpoint, so
334 * don't bother for if this is a temporary association.
336 if (!list_empty(&asoc
->asocs
)) {
337 list_del(&asoc
->asocs
);
339 /* Decrement the backlog value for a TCP-style listening
342 if (sctp_style(sk
, TCP
) && sctp_sstate(sk
, LISTENING
))
343 sk
->sk_ack_backlog
--;
346 /* Mark as dead, so other users can know this structure is
349 asoc
->base
.dead
= true;
351 /* Dispose of any data lying around in the outqueue. */
352 sctp_outq_free(&asoc
->outqueue
);
354 /* Dispose of any pending messages for the upper layer. */
355 sctp_ulpq_free(&asoc
->ulpq
);
357 /* Dispose of any pending chunks on the inqueue. */
358 sctp_inq_free(&asoc
->base
.inqueue
);
360 sctp_tsnmap_free(&asoc
->peer
.tsn_map
);
362 /* Free stream information. */
363 sctp_stream_free(asoc
->stream
);
365 if (asoc
->strreset_chunk
)
366 sctp_chunk_free(asoc
->strreset_chunk
);
368 /* Clean up the bound address list. */
369 sctp_bind_addr_free(&asoc
->base
.bind_addr
);
371 /* Do we need to go through all of our timers and
372 * delete them? To be safe we will try to delete all, but we
373 * should be able to go through and make a guess based
376 for (i
= SCTP_EVENT_TIMEOUT_NONE
; i
< SCTP_NUM_TIMEOUT_TYPES
; ++i
) {
377 if (del_timer(&asoc
->timers
[i
]))
378 sctp_association_put(asoc
);
381 /* Free peer's cached cookie. */
382 kfree(asoc
->peer
.cookie
);
383 kfree(asoc
->peer
.peer_random
);
384 kfree(asoc
->peer
.peer_chunks
);
385 kfree(asoc
->peer
.peer_hmacs
);
387 /* Release the transport structures. */
388 list_for_each_safe(pos
, temp
, &asoc
->peer
.transport_addr_list
) {
389 transport
= list_entry(pos
, struct sctp_transport
, transports
);
391 sctp_unhash_transport(transport
);
392 sctp_transport_free(transport
);
395 asoc
->peer
.transport_count
= 0;
397 sctp_asconf_queue_teardown(asoc
);
399 /* Free pending address space being deleted */
400 kfree(asoc
->asconf_addr_del_pending
);
402 /* AUTH - Free the endpoint shared keys */
403 sctp_auth_destroy_keys(&asoc
->endpoint_shared_keys
);
405 /* AUTH - Free the association shared key */
406 sctp_auth_key_put(asoc
->asoc_shared_key
);
408 sctp_association_put(asoc
);
411 /* Cleanup and free up an association. */
412 static void sctp_association_destroy(struct sctp_association
*asoc
)
414 if (unlikely(!asoc
->base
.dead
)) {
415 WARN(1, "Attempt to destroy undead association %p!\n", asoc
);
419 sctp_endpoint_put(asoc
->ep
);
420 sock_put(asoc
->base
.sk
);
422 if (asoc
->assoc_id
!= 0) {
423 spin_lock_bh(&sctp_assocs_id_lock
);
424 idr_remove(&sctp_assocs_id
, asoc
->assoc_id
);
425 spin_unlock_bh(&sctp_assocs_id_lock
);
428 WARN_ON(atomic_read(&asoc
->rmem_alloc
));
431 SCTP_DBG_OBJCNT_DEC(assoc
);
434 /* Change the primary destination address for the peer. */
435 void sctp_assoc_set_primary(struct sctp_association
*asoc
,
436 struct sctp_transport
*transport
)
440 /* it's a changeover only if we already have a primary path
441 * that we are changing
443 if (asoc
->peer
.primary_path
!= NULL
&&
444 asoc
->peer
.primary_path
!= transport
)
447 asoc
->peer
.primary_path
= transport
;
449 /* Set a default msg_name for events. */
450 memcpy(&asoc
->peer
.primary_addr
, &transport
->ipaddr
,
451 sizeof(union sctp_addr
));
453 /* If the primary path is changing, assume that the
454 * user wants to use this new path.
456 if ((transport
->state
== SCTP_ACTIVE
) ||
457 (transport
->state
== SCTP_UNKNOWN
))
458 asoc
->peer
.active_path
= transport
;
461 * SFR-CACC algorithm:
462 * Upon the receipt of a request to change the primary
463 * destination address, on the data structure for the new
464 * primary destination, the sender MUST do the following:
466 * 1) If CHANGEOVER_ACTIVE is set, then there was a switch
467 * to this destination address earlier. The sender MUST set
468 * CYCLING_CHANGEOVER to indicate that this switch is a
469 * double switch to the same destination address.
471 * Really, only bother is we have data queued or outstanding on
474 if (!asoc
->outqueue
.outstanding_bytes
&& !asoc
->outqueue
.out_qlen
)
477 if (transport
->cacc
.changeover_active
)
478 transport
->cacc
.cycling_changeover
= changeover
;
480 /* 2) The sender MUST set CHANGEOVER_ACTIVE to indicate that
481 * a changeover has occurred.
483 transport
->cacc
.changeover_active
= changeover
;
485 /* 3) The sender MUST store the next TSN to be sent in
486 * next_tsn_at_change.
488 transport
->cacc
.next_tsn_at_change
= asoc
->next_tsn
;
491 /* Remove a transport from an association. */
492 void sctp_assoc_rm_peer(struct sctp_association
*asoc
,
493 struct sctp_transport
*peer
)
495 struct list_head
*pos
;
496 struct sctp_transport
*transport
;
498 pr_debug("%s: association:%p addr:%pISpc\n",
499 __func__
, asoc
, &peer
->ipaddr
.sa
);
501 /* If we are to remove the current retran_path, update it
502 * to the next peer before removing this peer from the list.
504 if (asoc
->peer
.retran_path
== peer
)
505 sctp_assoc_update_retran_path(asoc
);
507 /* Remove this peer from the list. */
508 list_del_rcu(&peer
->transports
);
509 /* Remove this peer from the transport hashtable */
510 sctp_unhash_transport(peer
);
512 /* Get the first transport of asoc. */
513 pos
= asoc
->peer
.transport_addr_list
.next
;
514 transport
= list_entry(pos
, struct sctp_transport
, transports
);
516 /* Update any entries that match the peer to be deleted. */
517 if (asoc
->peer
.primary_path
== peer
)
518 sctp_assoc_set_primary(asoc
, transport
);
519 if (asoc
->peer
.active_path
== peer
)
520 asoc
->peer
.active_path
= transport
;
521 if (asoc
->peer
.retran_path
== peer
)
522 asoc
->peer
.retran_path
= transport
;
523 if (asoc
->peer
.last_data_from
== peer
)
524 asoc
->peer
.last_data_from
= transport
;
526 if (asoc
->strreset_chunk
&&
527 asoc
->strreset_chunk
->transport
== peer
) {
528 asoc
->strreset_chunk
->transport
= transport
;
529 sctp_transport_reset_reconf_timer(transport
);
532 /* If we remove the transport an INIT was last sent to, set it to
533 * NULL. Combined with the update of the retran path above, this
534 * will cause the next INIT to be sent to the next available
535 * transport, maintaining the cycle.
537 if (asoc
->init_last_sent_to
== peer
)
538 asoc
->init_last_sent_to
= NULL
;
540 /* If we remove the transport an SHUTDOWN was last sent to, set it
541 * to NULL. Combined with the update of the retran path above, this
542 * will cause the next SHUTDOWN to be sent to the next available
543 * transport, maintaining the cycle.
545 if (asoc
->shutdown_last_sent_to
== peer
)
546 asoc
->shutdown_last_sent_to
= NULL
;
548 /* If we remove the transport an ASCONF was last sent to, set it to
551 if (asoc
->addip_last_asconf
&&
552 asoc
->addip_last_asconf
->transport
== peer
)
553 asoc
->addip_last_asconf
->transport
= NULL
;
555 /* If we have something on the transmitted list, we have to
556 * save it off. The best place is the active path.
558 if (!list_empty(&peer
->transmitted
)) {
559 struct sctp_transport
*active
= asoc
->peer
.active_path
;
560 struct sctp_chunk
*ch
;
562 /* Reset the transport of each chunk on this list */
563 list_for_each_entry(ch
, &peer
->transmitted
,
565 ch
->transport
= NULL
;
566 ch
->rtt_in_progress
= 0;
569 list_splice_tail_init(&peer
->transmitted
,
570 &active
->transmitted
);
572 /* Start a T3 timer here in case it wasn't running so
573 * that these migrated packets have a chance to get
576 if (!timer_pending(&active
->T3_rtx_timer
))
577 if (!mod_timer(&active
->T3_rtx_timer
,
578 jiffies
+ active
->rto
))
579 sctp_transport_hold(active
);
582 asoc
->peer
.transport_count
--;
584 sctp_transport_free(peer
);
587 /* Add a transport address to an association. */
588 struct sctp_transport
*sctp_assoc_add_peer(struct sctp_association
*asoc
,
589 const union sctp_addr
*addr
,
591 const int peer_state
)
593 struct net
*net
= sock_net(asoc
->base
.sk
);
594 struct sctp_transport
*peer
;
595 struct sctp_sock
*sp
;
598 sp
= sctp_sk(asoc
->base
.sk
);
600 /* AF_INET and AF_INET6 share common port field. */
601 port
= ntohs(addr
->v4
.sin_port
);
603 pr_debug("%s: association:%p addr:%pISpc state:%d\n", __func__
,
604 asoc
, &addr
->sa
, peer_state
);
606 /* Set the port if it has not been set yet. */
607 if (0 == asoc
->peer
.port
)
608 asoc
->peer
.port
= port
;
610 /* Check to see if this is a duplicate. */
611 peer
= sctp_assoc_lookup_paddr(asoc
, addr
);
613 /* An UNKNOWN state is only set on transports added by
614 * user in sctp_connectx() call. Such transports should be
615 * considered CONFIRMED per RFC 4960, Section 5.4.
617 if (peer
->state
== SCTP_UNKNOWN
) {
618 peer
->state
= SCTP_ACTIVE
;
623 peer
= sctp_transport_new(net
, addr
, gfp
);
627 sctp_transport_set_owner(peer
, asoc
);
629 /* Initialize the peer's heartbeat interval based on the
630 * association configured value.
632 peer
->hbinterval
= asoc
->hbinterval
;
634 /* Set the path max_retrans. */
635 peer
->pathmaxrxt
= asoc
->pathmaxrxt
;
637 /* And the partial failure retrans threshold */
638 peer
->pf_retrans
= asoc
->pf_retrans
;
640 /* Initialize the peer's SACK delay timeout based on the
641 * association configured value.
643 peer
->sackdelay
= asoc
->sackdelay
;
644 peer
->sackfreq
= asoc
->sackfreq
;
646 /* Enable/disable heartbeat, SACK delay, and path MTU discovery
647 * based on association setting.
649 peer
->param_flags
= asoc
->param_flags
;
651 sctp_transport_route(peer
, NULL
, sp
);
653 /* Initialize the pmtu of the transport. */
654 if (peer
->param_flags
& SPP_PMTUD_DISABLE
) {
656 peer
->pathmtu
= asoc
->pathmtu
;
658 peer
->pathmtu
= SCTP_DEFAULT_MAXSEGMENT
;
661 /* If this is the first transport addr on this association,
662 * initialize the association PMTU to the peer's PMTU.
663 * If not and the current association PMTU is higher than the new
664 * peer's PMTU, reset the association PMTU to the new peer's PMTU.
667 asoc
->pathmtu
= min_t(int, peer
->pathmtu
, asoc
->pathmtu
);
669 asoc
->pathmtu
= peer
->pathmtu
;
671 pr_debug("%s: association:%p PMTU set to %d\n", __func__
, asoc
,
674 peer
->pmtu_pending
= 0;
676 asoc
->frag_point
= sctp_frag_point(asoc
, asoc
->pathmtu
);
678 /* The asoc->peer.port might not be meaningful yet, but
679 * initialize the packet structure anyway.
681 sctp_packet_init(&peer
->packet
, peer
, asoc
->base
.bind_addr
.port
,
686 * o The initial cwnd before DATA transmission or after a sufficiently
687 * long idle period MUST be set to
688 * min(4*MTU, max(2*MTU, 4380 bytes))
690 * o The initial value of ssthresh MAY be arbitrarily high
691 * (for example, implementations MAY use the size of the
692 * receiver advertised window).
694 peer
->cwnd
= min(4*asoc
->pathmtu
, max_t(__u32
, 2*asoc
->pathmtu
, 4380));
696 /* At this point, we may not have the receiver's advertised window,
697 * so initialize ssthresh to the default value and it will be set
698 * later when we process the INIT.
700 peer
->ssthresh
= SCTP_DEFAULT_MAXWINDOW
;
702 peer
->partial_bytes_acked
= 0;
703 peer
->flight_size
= 0;
704 peer
->burst_limited
= 0;
706 /* Set the transport's RTO.initial value */
707 peer
->rto
= asoc
->rto_initial
;
708 sctp_max_rto(asoc
, peer
);
710 /* Set the peer's active state. */
711 peer
->state
= peer_state
;
713 /* Add this peer into the transport hashtable */
714 if (sctp_hash_transport(peer
)) {
715 sctp_transport_free(peer
);
719 /* Attach the remote transport to our asoc. */
720 list_add_tail_rcu(&peer
->transports
, &asoc
->peer
.transport_addr_list
);
721 asoc
->peer
.transport_count
++;
723 /* If we do not yet have a primary path, set one. */
724 if (!asoc
->peer
.primary_path
) {
725 sctp_assoc_set_primary(asoc
, peer
);
726 asoc
->peer
.retran_path
= peer
;
729 if (asoc
->peer
.active_path
== asoc
->peer
.retran_path
&&
730 peer
->state
!= SCTP_UNCONFIRMED
) {
731 asoc
->peer
.retran_path
= peer
;
737 /* Delete a transport address from an association. */
738 void sctp_assoc_del_peer(struct sctp_association
*asoc
,
739 const union sctp_addr
*addr
)
741 struct list_head
*pos
;
742 struct list_head
*temp
;
743 struct sctp_transport
*transport
;
745 list_for_each_safe(pos
, temp
, &asoc
->peer
.transport_addr_list
) {
746 transport
= list_entry(pos
, struct sctp_transport
, transports
);
747 if (sctp_cmp_addr_exact(addr
, &transport
->ipaddr
)) {
748 /* Do book keeping for removing the peer and free it. */
749 sctp_assoc_rm_peer(asoc
, transport
);
755 /* Lookup a transport by address. */
756 struct sctp_transport
*sctp_assoc_lookup_paddr(
757 const struct sctp_association
*asoc
,
758 const union sctp_addr
*address
)
760 struct sctp_transport
*t
;
762 /* Cycle through all transports searching for a peer address. */
764 list_for_each_entry(t
, &asoc
->peer
.transport_addr_list
,
766 if (sctp_cmp_addr_exact(address
, &t
->ipaddr
))
773 /* Remove all transports except a give one */
774 void sctp_assoc_del_nonprimary_peers(struct sctp_association
*asoc
,
775 struct sctp_transport
*primary
)
777 struct sctp_transport
*temp
;
778 struct sctp_transport
*t
;
780 list_for_each_entry_safe(t
, temp
, &asoc
->peer
.transport_addr_list
,
782 /* if the current transport is not the primary one, delete it */
784 sctp_assoc_rm_peer(asoc
, t
);
788 /* Engage in transport control operations.
789 * Mark the transport up or down and send a notification to the user.
790 * Select and update the new active and retran paths.
792 void sctp_assoc_control_transport(struct sctp_association
*asoc
,
793 struct sctp_transport
*transport
,
794 sctp_transport_cmd_t command
,
795 sctp_sn_error_t error
)
797 struct sctp_ulpevent
*event
;
798 struct sockaddr_storage addr
;
800 bool ulp_notify
= true;
802 /* Record the transition on the transport. */
804 case SCTP_TRANSPORT_UP
:
805 /* If we are moving from UNCONFIRMED state due
806 * to heartbeat success, report the SCTP_ADDR_CONFIRMED
807 * state to the user, otherwise report SCTP_ADDR_AVAILABLE.
809 if (SCTP_UNCONFIRMED
== transport
->state
&&
810 SCTP_HEARTBEAT_SUCCESS
== error
)
811 spc_state
= SCTP_ADDR_CONFIRMED
;
813 spc_state
= SCTP_ADDR_AVAILABLE
;
814 /* Don't inform ULP about transition from PF to
815 * active state and set cwnd to 1 MTU, see SCTP
816 * Quick failover draft section 5.1, point 5
818 if (transport
->state
== SCTP_PF
) {
820 transport
->cwnd
= asoc
->pathmtu
;
822 transport
->state
= SCTP_ACTIVE
;
825 case SCTP_TRANSPORT_DOWN
:
826 /* If the transport was never confirmed, do not transition it
827 * to inactive state. Also, release the cached route since
828 * there may be a better route next time.
830 if (transport
->state
!= SCTP_UNCONFIRMED
)
831 transport
->state
= SCTP_INACTIVE
;
833 sctp_transport_dst_release(transport
);
837 spc_state
= SCTP_ADDR_UNREACHABLE
;
840 case SCTP_TRANSPORT_PF
:
841 transport
->state
= SCTP_PF
;
849 /* Generate and send a SCTP_PEER_ADDR_CHANGE notification
853 memset(&addr
, 0, sizeof(struct sockaddr_storage
));
854 memcpy(&addr
, &transport
->ipaddr
,
855 transport
->af_specific
->sockaddr_len
);
857 event
= sctp_ulpevent_make_peer_addr_change(asoc
, &addr
,
858 0, spc_state
, error
, GFP_ATOMIC
);
860 sctp_ulpq_tail_event(&asoc
->ulpq
, event
);
863 /* Select new active and retran paths. */
864 sctp_select_active_and_retran_path(asoc
);
867 /* Hold a reference to an association. */
868 void sctp_association_hold(struct sctp_association
*asoc
)
870 atomic_inc(&asoc
->base
.refcnt
);
873 /* Release a reference to an association and cleanup
874 * if there are no more references.
876 void sctp_association_put(struct sctp_association
*asoc
)
878 if (atomic_dec_and_test(&asoc
->base
.refcnt
))
879 sctp_association_destroy(asoc
);
882 /* Allocate the next TSN, Transmission Sequence Number, for the given
885 __u32
sctp_association_get_next_tsn(struct sctp_association
*asoc
)
887 /* From Section 1.6 Serial Number Arithmetic:
888 * Transmission Sequence Numbers wrap around when they reach
889 * 2**32 - 1. That is, the next TSN a DATA chunk MUST use
890 * after transmitting TSN = 2*32 - 1 is TSN = 0.
892 __u32 retval
= asoc
->next_tsn
;
899 /* Compare two addresses to see if they match. Wildcard addresses
900 * only match themselves.
902 int sctp_cmp_addr_exact(const union sctp_addr
*ss1
,
903 const union sctp_addr
*ss2
)
907 af
= sctp_get_af_specific(ss1
->sa
.sa_family
);
911 return af
->cmp_addr(ss1
, ss2
);
914 /* Return an ecne chunk to get prepended to a packet.
915 * Note: We are sly and return a shared, prealloced chunk. FIXME:
916 * No we don't, but we could/should.
918 struct sctp_chunk
*sctp_get_ecne_prepend(struct sctp_association
*asoc
)
920 if (!asoc
->need_ecne
)
923 /* Send ECNE if needed.
924 * Not being able to allocate a chunk here is not deadly.
926 return sctp_make_ecne(asoc
, asoc
->last_ecne_tsn
);
930 * Find which transport this TSN was sent on.
932 struct sctp_transport
*sctp_assoc_lookup_tsn(struct sctp_association
*asoc
,
935 struct sctp_transport
*active
;
936 struct sctp_transport
*match
;
937 struct sctp_transport
*transport
;
938 struct sctp_chunk
*chunk
;
939 __be32 key
= htonl(tsn
);
944 * FIXME: In general, find a more efficient data structure for
949 * The general strategy is to search each transport's transmitted
950 * list. Return which transport this TSN lives on.
952 * Let's be hopeful and check the active_path first.
953 * Another optimization would be to know if there is only one
954 * outbound path and not have to look for the TSN at all.
958 active
= asoc
->peer
.active_path
;
960 list_for_each_entry(chunk
, &active
->transmitted
,
963 if (key
== chunk
->subh
.data_hdr
->tsn
) {
969 /* If not found, go search all the other transports. */
970 list_for_each_entry(transport
, &asoc
->peer
.transport_addr_list
,
973 if (transport
== active
)
975 list_for_each_entry(chunk
, &transport
->transmitted
,
977 if (key
== chunk
->subh
.data_hdr
->tsn
) {
987 /* Is this the association we are looking for? */
988 struct sctp_transport
*sctp_assoc_is_match(struct sctp_association
*asoc
,
990 const union sctp_addr
*laddr
,
991 const union sctp_addr
*paddr
)
993 struct sctp_transport
*transport
;
995 if ((htons(asoc
->base
.bind_addr
.port
) == laddr
->v4
.sin_port
) &&
996 (htons(asoc
->peer
.port
) == paddr
->v4
.sin_port
) &&
997 net_eq(sock_net(asoc
->base
.sk
), net
)) {
998 transport
= sctp_assoc_lookup_paddr(asoc
, paddr
);
1002 if (sctp_bind_addr_match(&asoc
->base
.bind_addr
, laddr
,
1003 sctp_sk(asoc
->base
.sk
)))
1012 /* Do delayed input processing. This is scheduled by sctp_rcv(). */
1013 static void sctp_assoc_bh_rcv(struct work_struct
*work
)
1015 struct sctp_association
*asoc
=
1016 container_of(work
, struct sctp_association
,
1017 base
.inqueue
.immediate
);
1018 struct net
*net
= sock_net(asoc
->base
.sk
);
1019 struct sctp_endpoint
*ep
;
1020 struct sctp_chunk
*chunk
;
1021 struct sctp_inq
*inqueue
;
1023 sctp_subtype_t subtype
;
1026 /* The association should be held so we should be safe. */
1029 inqueue
= &asoc
->base
.inqueue
;
1030 sctp_association_hold(asoc
);
1031 while (NULL
!= (chunk
= sctp_inq_pop(inqueue
))) {
1032 state
= asoc
->state
;
1033 subtype
= SCTP_ST_CHUNK(chunk
->chunk_hdr
->type
);
1035 /* SCTP-AUTH, Section 6.3:
1036 * The receiver has a list of chunk types which it expects
1037 * to be received only after an AUTH-chunk. This list has
1038 * been sent to the peer during the association setup. It
1039 * MUST silently discard these chunks if they are not placed
1040 * after an AUTH chunk in the packet.
1042 if (sctp_auth_recv_cid(subtype
.chunk
, asoc
) && !chunk
->auth
)
1045 /* Remember where the last DATA chunk came from so we
1046 * know where to send the SACK.
1048 if (sctp_chunk_is_data(chunk
))
1049 asoc
->peer
.last_data_from
= chunk
->transport
;
1051 SCTP_INC_STATS(net
, SCTP_MIB_INCTRLCHUNKS
);
1052 asoc
->stats
.ictrlchunks
++;
1053 if (chunk
->chunk_hdr
->type
== SCTP_CID_SACK
)
1054 asoc
->stats
.isacks
++;
1057 if (chunk
->transport
)
1058 chunk
->transport
->last_time_heard
= ktime_get();
1060 /* Run through the state machine. */
1061 error
= sctp_do_sm(net
, SCTP_EVENT_T_CHUNK
, subtype
,
1062 state
, ep
, asoc
, chunk
, GFP_ATOMIC
);
1064 /* Check to see if the association is freed in response to
1065 * the incoming chunk. If so, get out of the while loop.
1067 if (asoc
->base
.dead
)
1070 /* If there is an error on chunk, discard this packet. */
1072 chunk
->pdiscard
= 1;
1074 sctp_association_put(asoc
);
1077 /* This routine moves an association from its old sk to a new sk. */
1078 void sctp_assoc_migrate(struct sctp_association
*assoc
, struct sock
*newsk
)
1080 struct sctp_sock
*newsp
= sctp_sk(newsk
);
1081 struct sock
*oldsk
= assoc
->base
.sk
;
1083 /* Delete the association from the old endpoint's list of
1086 list_del_init(&assoc
->asocs
);
1088 /* Decrement the backlog value for a TCP-style socket. */
1089 if (sctp_style(oldsk
, TCP
))
1090 oldsk
->sk_ack_backlog
--;
1092 /* Release references to the old endpoint and the sock. */
1093 sctp_endpoint_put(assoc
->ep
);
1094 sock_put(assoc
->base
.sk
);
1096 /* Get a reference to the new endpoint. */
1097 assoc
->ep
= newsp
->ep
;
1098 sctp_endpoint_hold(assoc
->ep
);
1100 /* Get a reference to the new sock. */
1101 assoc
->base
.sk
= newsk
;
1102 sock_hold(assoc
->base
.sk
);
1104 /* Add the association to the new endpoint's list of associations. */
1105 sctp_endpoint_add_asoc(newsp
->ep
, assoc
);
1108 /* Update an association (possibly from unexpected COOKIE-ECHO processing). */
1109 void sctp_assoc_update(struct sctp_association
*asoc
,
1110 struct sctp_association
*new)
1112 struct sctp_transport
*trans
;
1113 struct list_head
*pos
, *temp
;
1115 /* Copy in new parameters of peer. */
1117 asoc
->peer
.rwnd
= new->peer
.rwnd
;
1118 asoc
->peer
.sack_needed
= new->peer
.sack_needed
;
1119 asoc
->peer
.auth_capable
= new->peer
.auth_capable
;
1120 asoc
->peer
.i
= new->peer
.i
;
1121 sctp_tsnmap_init(&asoc
->peer
.tsn_map
, SCTP_TSN_MAP_INITIAL
,
1122 asoc
->peer
.i
.initial_tsn
, GFP_ATOMIC
);
1124 /* Remove any peer addresses not present in the new association. */
1125 list_for_each_safe(pos
, temp
, &asoc
->peer
.transport_addr_list
) {
1126 trans
= list_entry(pos
, struct sctp_transport
, transports
);
1127 if (!sctp_assoc_lookup_paddr(new, &trans
->ipaddr
)) {
1128 sctp_assoc_rm_peer(asoc
, trans
);
1132 if (asoc
->state
>= SCTP_STATE_ESTABLISHED
)
1133 sctp_transport_reset(trans
);
1136 /* If the case is A (association restart), use
1137 * initial_tsn as next_tsn. If the case is B, use
1138 * current next_tsn in case data sent to peer
1139 * has been discarded and needs retransmission.
1141 if (asoc
->state
>= SCTP_STATE_ESTABLISHED
) {
1142 asoc
->next_tsn
= new->next_tsn
;
1143 asoc
->ctsn_ack_point
= new->ctsn_ack_point
;
1144 asoc
->adv_peer_ack_point
= new->adv_peer_ack_point
;
1146 /* Reinitialize SSN for both local streams
1147 * and peer's streams.
1149 sctp_stream_clear(asoc
->stream
);
1151 /* Flush the ULP reassembly and ordered queue.
1152 * Any data there will now be stale and will
1155 sctp_ulpq_flush(&asoc
->ulpq
);
1157 /* reset the overall association error count so
1158 * that the restarted association doesn't get torn
1159 * down on the next retransmission timer.
1161 asoc
->overall_error_count
= 0;
1164 /* Add any peer addresses from the new association. */
1165 list_for_each_entry(trans
, &new->peer
.transport_addr_list
,
1167 if (!sctp_assoc_lookup_paddr(asoc
, &trans
->ipaddr
))
1168 sctp_assoc_add_peer(asoc
, &trans
->ipaddr
,
1169 GFP_ATOMIC
, trans
->state
);
1172 asoc
->ctsn_ack_point
= asoc
->next_tsn
- 1;
1173 asoc
->adv_peer_ack_point
= asoc
->ctsn_ack_point
;
1174 if (!asoc
->stream
) {
1175 asoc
->stream
= new->stream
;
1179 if (!asoc
->assoc_id
) {
1180 /* get a new association id since we don't have one
1183 sctp_assoc_set_id(asoc
, GFP_ATOMIC
);
1187 /* SCTP-AUTH: Save the peer parameters from the new associations
1188 * and also move the association shared keys over
1190 kfree(asoc
->peer
.peer_random
);
1191 asoc
->peer
.peer_random
= new->peer
.peer_random
;
1192 new->peer
.peer_random
= NULL
;
1194 kfree(asoc
->peer
.peer_chunks
);
1195 asoc
->peer
.peer_chunks
= new->peer
.peer_chunks
;
1196 new->peer
.peer_chunks
= NULL
;
1198 kfree(asoc
->peer
.peer_hmacs
);
1199 asoc
->peer
.peer_hmacs
= new->peer
.peer_hmacs
;
1200 new->peer
.peer_hmacs
= NULL
;
1202 sctp_auth_asoc_init_active_key(asoc
, GFP_ATOMIC
);
1205 /* Update the retran path for sending a retransmitted packet.
1206 * See also RFC4960, 6.4. Multi-Homed SCTP Endpoints:
1208 * When there is outbound data to send and the primary path
1209 * becomes inactive (e.g., due to failures), or where the
1210 * SCTP user explicitly requests to send data to an
1211 * inactive destination transport address, before reporting
1212 * an error to its ULP, the SCTP endpoint should try to send
1213 * the data to an alternate active destination transport
1214 * address if one exists.
1216 * When retransmitting data that timed out, if the endpoint
1217 * is multihomed, it should consider each source-destination
1218 * address pair in its retransmission selection policy.
1219 * When retransmitting timed-out data, the endpoint should
1220 * attempt to pick the most divergent source-destination
1221 * pair from the original source-destination pair to which
1222 * the packet was transmitted.
1224 * Note: Rules for picking the most divergent source-destination
1225 * pair are an implementation decision and are not specified
1226 * within this document.
1228 * Our basic strategy is to round-robin transports in priorities
1229 * according to sctp_trans_score() e.g., if no such
1230 * transport with state SCTP_ACTIVE exists, round-robin through
1231 * SCTP_UNKNOWN, etc. You get the picture.
1233 static u8
sctp_trans_score(const struct sctp_transport
*trans
)
1235 switch (trans
->state
) {
1237 return 3; /* best case */
1242 default: /* case SCTP_INACTIVE */
1243 return 0; /* worst case */
1247 static struct sctp_transport
*sctp_trans_elect_tie(struct sctp_transport
*trans1
,
1248 struct sctp_transport
*trans2
)
1250 if (trans1
->error_count
> trans2
->error_count
) {
1252 } else if (trans1
->error_count
== trans2
->error_count
&&
1253 ktime_after(trans2
->last_time_heard
,
1254 trans1
->last_time_heard
)) {
1261 static struct sctp_transport
*sctp_trans_elect_best(struct sctp_transport
*curr
,
1262 struct sctp_transport
*best
)
1264 u8 score_curr
, score_best
;
1266 if (best
== NULL
|| curr
== best
)
1269 score_curr
= sctp_trans_score(curr
);
1270 score_best
= sctp_trans_score(best
);
1272 /* First, try a score-based selection if both transport states
1273 * differ. If we're in a tie, lets try to make a more clever
1274 * decision here based on error counts and last time heard.
1276 if (score_curr
> score_best
)
1278 else if (score_curr
== score_best
)
1279 return sctp_trans_elect_tie(best
, curr
);
1284 void sctp_assoc_update_retran_path(struct sctp_association
*asoc
)
1286 struct sctp_transport
*trans
= asoc
->peer
.retran_path
;
1287 struct sctp_transport
*trans_next
= NULL
;
1289 /* We're done as we only have the one and only path. */
1290 if (asoc
->peer
.transport_count
== 1)
1292 /* If active_path and retran_path are the same and active,
1293 * then this is the only active path. Use it.
1295 if (asoc
->peer
.active_path
== asoc
->peer
.retran_path
&&
1296 asoc
->peer
.active_path
->state
== SCTP_ACTIVE
)
1299 /* Iterate from retran_path's successor back to retran_path. */
1300 for (trans
= list_next_entry(trans
, transports
); 1;
1301 trans
= list_next_entry(trans
, transports
)) {
1302 /* Manually skip the head element. */
1303 if (&trans
->transports
== &asoc
->peer
.transport_addr_list
)
1305 if (trans
->state
== SCTP_UNCONFIRMED
)
1307 trans_next
= sctp_trans_elect_best(trans
, trans_next
);
1308 /* Active is good enough for immediate return. */
1309 if (trans_next
->state
== SCTP_ACTIVE
)
1311 /* We've reached the end, time to update path. */
1312 if (trans
== asoc
->peer
.retran_path
)
1316 asoc
->peer
.retran_path
= trans_next
;
1318 pr_debug("%s: association:%p updated new path to addr:%pISpc\n",
1319 __func__
, asoc
, &asoc
->peer
.retran_path
->ipaddr
.sa
);
1322 static void sctp_select_active_and_retran_path(struct sctp_association
*asoc
)
1324 struct sctp_transport
*trans
, *trans_pri
= NULL
, *trans_sec
= NULL
;
1325 struct sctp_transport
*trans_pf
= NULL
;
1327 /* Look for the two most recently used active transports. */
1328 list_for_each_entry(trans
, &asoc
->peer
.transport_addr_list
,
1330 /* Skip uninteresting transports. */
1331 if (trans
->state
== SCTP_INACTIVE
||
1332 trans
->state
== SCTP_UNCONFIRMED
)
1334 /* Keep track of the best PF transport from our
1335 * list in case we don't find an active one.
1337 if (trans
->state
== SCTP_PF
) {
1338 trans_pf
= sctp_trans_elect_best(trans
, trans_pf
);
1341 /* For active transports, pick the most recent ones. */
1342 if (trans_pri
== NULL
||
1343 ktime_after(trans
->last_time_heard
,
1344 trans_pri
->last_time_heard
)) {
1345 trans_sec
= trans_pri
;
1347 } else if (trans_sec
== NULL
||
1348 ktime_after(trans
->last_time_heard
,
1349 trans_sec
->last_time_heard
)) {
1354 /* RFC 2960 6.4 Multi-Homed SCTP Endpoints
1356 * By default, an endpoint should always transmit to the primary
1357 * path, unless the SCTP user explicitly specifies the
1358 * destination transport address (and possibly source transport
1359 * address) to use. [If the primary is active but not most recent,
1360 * bump the most recently used transport.]
1362 if ((asoc
->peer
.primary_path
->state
== SCTP_ACTIVE
||
1363 asoc
->peer
.primary_path
->state
== SCTP_UNKNOWN
) &&
1364 asoc
->peer
.primary_path
!= trans_pri
) {
1365 trans_sec
= trans_pri
;
1366 trans_pri
= asoc
->peer
.primary_path
;
1369 /* We did not find anything useful for a possible retransmission
1370 * path; either primary path that we found is the the same as
1371 * the current one, or we didn't generally find an active one.
1373 if (trans_sec
== NULL
)
1374 trans_sec
= trans_pri
;
1376 /* If we failed to find a usable transport, just camp on the
1377 * active or pick a PF iff it's the better choice.
1379 if (trans_pri
== NULL
) {
1380 trans_pri
= sctp_trans_elect_best(asoc
->peer
.active_path
, trans_pf
);
1381 trans_sec
= trans_pri
;
1384 /* Set the active and retran transports. */
1385 asoc
->peer
.active_path
= trans_pri
;
1386 asoc
->peer
.retran_path
= trans_sec
;
1389 struct sctp_transport
*
1390 sctp_assoc_choose_alter_transport(struct sctp_association
*asoc
,
1391 struct sctp_transport
*last_sent_to
)
1393 /* If this is the first time packet is sent, use the active path,
1394 * else use the retran path. If the last packet was sent over the
1395 * retran path, update the retran path and use it.
1397 if (last_sent_to
== NULL
) {
1398 return asoc
->peer
.active_path
;
1400 if (last_sent_to
== asoc
->peer
.retran_path
)
1401 sctp_assoc_update_retran_path(asoc
);
1403 return asoc
->peer
.retran_path
;
1407 /* Update the association's pmtu and frag_point by going through all the
1408 * transports. This routine is called when a transport's PMTU has changed.
1410 void sctp_assoc_sync_pmtu(struct sock
*sk
, struct sctp_association
*asoc
)
1412 struct sctp_transport
*t
;
1418 /* Get the lowest pmtu of all the transports. */
1419 list_for_each_entry(t
, &asoc
->peer
.transport_addr_list
,
1421 if (t
->pmtu_pending
&& t
->dst
) {
1422 sctp_transport_update_pmtu(sk
, t
,
1423 SCTP_TRUNC4(dst_mtu(t
->dst
)));
1424 t
->pmtu_pending
= 0;
1426 if (!pmtu
|| (t
->pathmtu
< pmtu
))
1431 asoc
->pathmtu
= pmtu
;
1432 asoc
->frag_point
= sctp_frag_point(asoc
, pmtu
);
1435 pr_debug("%s: asoc:%p, pmtu:%d, frag_point:%d\n", __func__
, asoc
,
1436 asoc
->pathmtu
, asoc
->frag_point
);
1439 /* Should we send a SACK to update our peer? */
1440 static inline bool sctp_peer_needs_update(struct sctp_association
*asoc
)
1442 struct net
*net
= sock_net(asoc
->base
.sk
);
1443 switch (asoc
->state
) {
1444 case SCTP_STATE_ESTABLISHED
:
1445 case SCTP_STATE_SHUTDOWN_PENDING
:
1446 case SCTP_STATE_SHUTDOWN_RECEIVED
:
1447 case SCTP_STATE_SHUTDOWN_SENT
:
1448 if ((asoc
->rwnd
> asoc
->a_rwnd
) &&
1449 ((asoc
->rwnd
- asoc
->a_rwnd
) >= max_t(__u32
,
1450 (asoc
->base
.sk
->sk_rcvbuf
>> net
->sctp
.rwnd_upd_shift
),
1460 /* Increase asoc's rwnd by len and send any window update SACK if needed. */
1461 void sctp_assoc_rwnd_increase(struct sctp_association
*asoc
, unsigned int len
)
1463 struct sctp_chunk
*sack
;
1464 struct timer_list
*timer
;
1466 if (asoc
->rwnd_over
) {
1467 if (asoc
->rwnd_over
>= len
) {
1468 asoc
->rwnd_over
-= len
;
1470 asoc
->rwnd
+= (len
- asoc
->rwnd_over
);
1471 asoc
->rwnd_over
= 0;
1477 /* If we had window pressure, start recovering it
1478 * once our rwnd had reached the accumulated pressure
1479 * threshold. The idea is to recover slowly, but up
1480 * to the initial advertised window.
1482 if (asoc
->rwnd_press
) {
1483 int change
= min(asoc
->pathmtu
, asoc
->rwnd_press
);
1484 asoc
->rwnd
+= change
;
1485 asoc
->rwnd_press
-= change
;
1488 pr_debug("%s: asoc:%p rwnd increased by %d to (%u, %u) - %u\n",
1489 __func__
, asoc
, len
, asoc
->rwnd
, asoc
->rwnd_over
,
1492 /* Send a window update SACK if the rwnd has increased by at least the
1493 * minimum of the association's PMTU and half of the receive buffer.
1494 * The algorithm used is similar to the one described in
1495 * Section 4.2.3.3 of RFC 1122.
1497 if (sctp_peer_needs_update(asoc
)) {
1498 asoc
->a_rwnd
= asoc
->rwnd
;
1500 pr_debug("%s: sending window update SACK- asoc:%p rwnd:%u "
1501 "a_rwnd:%u\n", __func__
, asoc
, asoc
->rwnd
,
1504 sack
= sctp_make_sack(asoc
);
1508 asoc
->peer
.sack_needed
= 0;
1510 sctp_outq_tail(&asoc
->outqueue
, sack
, GFP_ATOMIC
);
1512 /* Stop the SACK timer. */
1513 timer
= &asoc
->timers
[SCTP_EVENT_TIMEOUT_SACK
];
1514 if (del_timer(timer
))
1515 sctp_association_put(asoc
);
1519 /* Decrease asoc's rwnd by len. */
1520 void sctp_assoc_rwnd_decrease(struct sctp_association
*asoc
, unsigned int len
)
1525 if (unlikely(!asoc
->rwnd
|| asoc
->rwnd_over
))
1526 pr_debug("%s: association:%p has asoc->rwnd:%u, "
1527 "asoc->rwnd_over:%u!\n", __func__
, asoc
,
1528 asoc
->rwnd
, asoc
->rwnd_over
);
1530 if (asoc
->ep
->rcvbuf_policy
)
1531 rx_count
= atomic_read(&asoc
->rmem_alloc
);
1533 rx_count
= atomic_read(&asoc
->base
.sk
->sk_rmem_alloc
);
1535 /* If we've reached or overflowed our receive buffer, announce
1536 * a 0 rwnd if rwnd would still be positive. Store the
1537 * the potential pressure overflow so that the window can be restored
1538 * back to original value.
1540 if (rx_count
>= asoc
->base
.sk
->sk_rcvbuf
)
1543 if (asoc
->rwnd
>= len
) {
1546 asoc
->rwnd_press
+= asoc
->rwnd
;
1550 asoc
->rwnd_over
+= len
- asoc
->rwnd
;
1554 pr_debug("%s: asoc:%p rwnd decreased by %d to (%u, %u, %u)\n",
1555 __func__
, asoc
, len
, asoc
->rwnd
, asoc
->rwnd_over
,
1559 /* Build the bind address list for the association based on info from the
1560 * local endpoint and the remote peer.
1562 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association
*asoc
,
1563 sctp_scope_t scope
, gfp_t gfp
)
1567 /* Use scoping rules to determine the subset of addresses from
1570 flags
= (PF_INET6
== asoc
->base
.sk
->sk_family
) ? SCTP_ADDR6_ALLOWED
: 0;
1571 if (asoc
->peer
.ipv4_address
)
1572 flags
|= SCTP_ADDR4_PEERSUPP
;
1573 if (asoc
->peer
.ipv6_address
)
1574 flags
|= SCTP_ADDR6_PEERSUPP
;
1576 return sctp_bind_addr_copy(sock_net(asoc
->base
.sk
),
1577 &asoc
->base
.bind_addr
,
1578 &asoc
->ep
->base
.bind_addr
,
1582 /* Build the association's bind address list from the cookie. */
1583 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association
*asoc
,
1584 struct sctp_cookie
*cookie
,
1587 int var_size2
= ntohs(cookie
->peer_init
->chunk_hdr
.length
);
1588 int var_size3
= cookie
->raw_addr_list_len
;
1589 __u8
*raw
= (__u8
*)cookie
->peer_init
+ var_size2
;
1591 return sctp_raw_to_bind_addrs(&asoc
->base
.bind_addr
, raw
, var_size3
,
1592 asoc
->ep
->base
.bind_addr
.port
, gfp
);
1595 /* Lookup laddr in the bind address list of an association. */
1596 int sctp_assoc_lookup_laddr(struct sctp_association
*asoc
,
1597 const union sctp_addr
*laddr
)
1601 if ((asoc
->base
.bind_addr
.port
== ntohs(laddr
->v4
.sin_port
)) &&
1602 sctp_bind_addr_match(&asoc
->base
.bind_addr
, laddr
,
1603 sctp_sk(asoc
->base
.sk
)))
1609 /* Set an association id for a given association */
1610 int sctp_assoc_set_id(struct sctp_association
*asoc
, gfp_t gfp
)
1612 bool preload
= gfpflags_allow_blocking(gfp
);
1615 /* If the id is already assigned, keep it. */
1621 spin_lock_bh(&sctp_assocs_id_lock
);
1622 /* 0 is not a valid assoc_id, must be >= 1 */
1623 ret
= idr_alloc_cyclic(&sctp_assocs_id
, asoc
, 1, 0, GFP_NOWAIT
);
1624 spin_unlock_bh(&sctp_assocs_id_lock
);
1630 asoc
->assoc_id
= (sctp_assoc_t
)ret
;
1634 /* Free the ASCONF queue */
1635 static void sctp_assoc_free_asconf_queue(struct sctp_association
*asoc
)
1637 struct sctp_chunk
*asconf
;
1638 struct sctp_chunk
*tmp
;
1640 list_for_each_entry_safe(asconf
, tmp
, &asoc
->addip_chunk_list
, list
) {
1641 list_del_init(&asconf
->list
);
1642 sctp_chunk_free(asconf
);
1646 /* Free asconf_ack cache */
1647 static void sctp_assoc_free_asconf_acks(struct sctp_association
*asoc
)
1649 struct sctp_chunk
*ack
;
1650 struct sctp_chunk
*tmp
;
1652 list_for_each_entry_safe(ack
, tmp
, &asoc
->asconf_ack_list
,
1654 list_del_init(&ack
->transmitted_list
);
1655 sctp_chunk_free(ack
);
1659 /* Clean up the ASCONF_ACK queue */
1660 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association
*asoc
)
1662 struct sctp_chunk
*ack
;
1663 struct sctp_chunk
*tmp
;
1665 /* We can remove all the entries from the queue up to
1666 * the "Peer-Sequence-Number".
1668 list_for_each_entry_safe(ack
, tmp
, &asoc
->asconf_ack_list
,
1670 if (ack
->subh
.addip_hdr
->serial
==
1671 htonl(asoc
->peer
.addip_serial
))
1674 list_del_init(&ack
->transmitted_list
);
1675 sctp_chunk_free(ack
);
1679 /* Find the ASCONF_ACK whose serial number matches ASCONF */
1680 struct sctp_chunk
*sctp_assoc_lookup_asconf_ack(
1681 const struct sctp_association
*asoc
,
1684 struct sctp_chunk
*ack
;
1686 /* Walk through the list of cached ASCONF-ACKs and find the
1687 * ack chunk whose serial number matches that of the request.
1689 list_for_each_entry(ack
, &asoc
->asconf_ack_list
, transmitted_list
) {
1690 if (sctp_chunk_pending(ack
))
1692 if (ack
->subh
.addip_hdr
->serial
== serial
) {
1693 sctp_chunk_hold(ack
);
1701 void sctp_asconf_queue_teardown(struct sctp_association
*asoc
)
1703 /* Free any cached ASCONF_ACK chunk. */
1704 sctp_assoc_free_asconf_acks(asoc
);
1706 /* Free the ASCONF queue. */
1707 sctp_assoc_free_asconf_queue(asoc
);
1709 /* Free any cached ASCONF chunk. */
1710 if (asoc
->addip_last_asconf
)
1711 sctp_chunk_free(asoc
->addip_last_asconf
);