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 <linux-sctp@vger.kernel.org>
33 * Written or modified by:
34 * La Monte H.P. Yarroll <piggy@acm.org>
35 * Karl Knutson <karl@athena.chicago.il.us>
36 * Jon Grimm <jgrimm@us.ibm.com>
37 * Xingang Guo <xingang.guo@intel.com>
38 * Hui Huang <hui.huang@nokia.com>
39 * Sridhar Samudrala <sri@us.ibm.com>
40 * Daisy Chang <daisyc@us.ibm.com>
41 * Ryan Layer <rmlayer@us.ibm.com>
42 * Kevin Gao <kevin.gao@intel.com>
45 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
47 #include <linux/types.h>
48 #include <linux/fcntl.h>
49 #include <linux/poll.h>
50 #include <linux/init.h>
52 #include <linux/slab.h>
55 #include <net/sctp/sctp.h>
56 #include <net/sctp/sm.h>
58 /* Forward declarations for internal functions. */
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
);
78 /* Retrieve the SCTP per socket area. */
79 sp
= sctp_sk((struct sock
*)sk
);
81 /* Discarding const is appropriate here. */
82 asoc
->ep
= (struct sctp_endpoint
*)ep
;
83 asoc
->base
.sk
= (struct sock
*)sk
;
85 sctp_endpoint_hold(asoc
->ep
);
86 sock_hold(asoc
->base
.sk
);
88 /* Initialize the common base substructure. */
89 asoc
->base
.type
= SCTP_EP_TYPE_ASSOCIATION
;
91 /* Initialize the object handling fields. */
92 atomic_set(&asoc
->base
.refcnt
, 1);
93 asoc
->base
.dead
= false;
95 /* Initialize the bind addr area. */
96 sctp_bind_addr_init(&asoc
->base
.bind_addr
, ep
->base
.bind_addr
.port
);
98 asoc
->state
= SCTP_STATE_CLOSED
;
99 asoc
->cookie_life
= ms_to_ktime(sp
->assocparams
.sasoc_cookie_life
);
100 asoc
->frag_point
= 0;
101 asoc
->user_frag
= sp
->user_frag
;
103 /* Set the association max_retrans and RTO values from the
106 asoc
->max_retrans
= sp
->assocparams
.sasoc_asocmaxrxt
;
107 asoc
->pf_retrans
= net
->sctp
.pf_retrans
;
109 asoc
->rto_initial
= msecs_to_jiffies(sp
->rtoinfo
.srto_initial
);
110 asoc
->rto_max
= msecs_to_jiffies(sp
->rtoinfo
.srto_max
);
111 asoc
->rto_min
= msecs_to_jiffies(sp
->rtoinfo
.srto_min
);
113 asoc
->overall_error_count
= 0;
115 /* Initialize the association's heartbeat interval based on the
116 * sock configured value.
118 asoc
->hbinterval
= msecs_to_jiffies(sp
->hbinterval
);
120 /* Initialize path max retrans value. */
121 asoc
->pathmaxrxt
= sp
->pathmaxrxt
;
123 /* Initialize default path MTU. */
124 asoc
->pathmtu
= sp
->pathmtu
;
126 /* Set association default SACK delay */
127 asoc
->sackdelay
= msecs_to_jiffies(sp
->sackdelay
);
128 asoc
->sackfreq
= sp
->sackfreq
;
130 /* Set the association default flags controlling
131 * Heartbeat, SACK delay, and Path MTU Discovery.
133 asoc
->param_flags
= sp
->param_flags
;
135 /* Initialize the maximum mumber of new data packets that can be sent
138 asoc
->max_burst
= sp
->max_burst
;
140 /* initialize association timers */
141 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_NONE
] = 0;
142 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_T1_COOKIE
] = asoc
->rto_initial
;
143 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_T1_INIT
] = asoc
->rto_initial
;
144 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
] = asoc
->rto_initial
;
145 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_T3_RTX
] = 0;
146 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_T4_RTO
] = 0;
148 /* sctpimpguide Section 2.12.2
149 * If the 'T5-shutdown-guard' timer is used, it SHOULD be set to the
150 * recommended value of 5 times 'RTO.Max'.
152 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
]
155 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_HEARTBEAT
] = 0;
156 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_SACK
] = asoc
->sackdelay
;
157 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_AUTOCLOSE
] = sp
->autoclose
* HZ
;
159 /* Initializes the timers */
160 for (i
= SCTP_EVENT_TIMEOUT_NONE
; i
< SCTP_NUM_TIMEOUT_TYPES
; ++i
)
161 setup_timer(&asoc
->timers
[i
], sctp_timer_events
[i
],
162 (unsigned long)asoc
);
164 /* Pull default initialization values from the sock options.
165 * Note: This assumes that the values have already been
166 * validated in the sock.
168 asoc
->c
.sinit_max_instreams
= sp
->initmsg
.sinit_max_instreams
;
169 asoc
->c
.sinit_num_ostreams
= sp
->initmsg
.sinit_num_ostreams
;
170 asoc
->max_init_attempts
= sp
->initmsg
.sinit_max_attempts
;
172 asoc
->max_init_timeo
=
173 msecs_to_jiffies(sp
->initmsg
.sinit_max_init_timeo
);
175 /* Allocate storage for the ssnmap after the inbound and outbound
176 * streams have been negotiated during Init.
180 /* Set the local window size for receive.
181 * This is also the rcvbuf space per association.
182 * RFC 6 - A SCTP receiver MUST be able to receive a minimum of
183 * 1500 bytes in one SCTP packet.
185 if ((sk
->sk_rcvbuf
/2) < SCTP_DEFAULT_MINWINDOW
)
186 asoc
->rwnd
= SCTP_DEFAULT_MINWINDOW
;
188 asoc
->rwnd
= sk
->sk_rcvbuf
/2;
190 asoc
->a_rwnd
= asoc
->rwnd
;
193 asoc
->rwnd_press
= 0;
195 /* Use my own max window until I learn something better. */
196 asoc
->peer
.rwnd
= SCTP_DEFAULT_MAXWINDOW
;
198 /* Set the sndbuf size for transmit. */
199 asoc
->sndbuf_used
= 0;
201 /* Initialize the receive memory counter */
202 atomic_set(&asoc
->rmem_alloc
, 0);
204 init_waitqueue_head(&asoc
->wait
);
206 asoc
->c
.my_vtag
= sctp_generate_tag(ep
);
207 asoc
->peer
.i
.init_tag
= 0; /* INIT needs a vtag of 0. */
208 asoc
->c
.peer_vtag
= 0;
210 asoc
->c
.peer_ttag
= 0;
211 asoc
->c
.my_port
= ep
->base
.bind_addr
.port
;
213 asoc
->c
.initial_tsn
= sctp_generate_tsn(ep
);
215 asoc
->next_tsn
= asoc
->c
.initial_tsn
;
217 asoc
->ctsn_ack_point
= asoc
->next_tsn
- 1;
218 asoc
->adv_peer_ack_point
= asoc
->ctsn_ack_point
;
219 asoc
->highest_sacked
= asoc
->ctsn_ack_point
;
220 asoc
->last_cwr_tsn
= asoc
->ctsn_ack_point
;
221 asoc
->unack_data
= 0;
223 /* ADDIP Section 4.1 Asconf Chunk Procedures
225 * When an endpoint has an ASCONF signaled change to be sent to the
226 * remote endpoint it should do the following:
228 * A2) a serial number should be assigned to the chunk. The serial
229 * number SHOULD be a monotonically increasing number. The serial
230 * numbers SHOULD be initialized at the start of the
231 * association to the same value as the initial TSN.
233 asoc
->addip_serial
= asoc
->c
.initial_tsn
;
235 INIT_LIST_HEAD(&asoc
->addip_chunk_list
);
236 INIT_LIST_HEAD(&asoc
->asconf_ack_list
);
238 /* Make an empty list of remote transport addresses. */
239 INIT_LIST_HEAD(&asoc
->peer
.transport_addr_list
);
240 asoc
->peer
.transport_count
= 0;
242 /* RFC 2960 5.1 Normal Establishment of an Association
244 * After the reception of the first data chunk in an
245 * association the endpoint must immediately respond with a
246 * sack to acknowledge the data chunk. Subsequent
247 * acknowledgements should be done as described in Section
250 * [We implement this by telling a new association that it
251 * already received one packet.]
253 asoc
->peer
.sack_needed
= 1;
254 asoc
->peer
.sack_cnt
= 0;
255 asoc
->peer
.sack_generation
= 1;
257 /* Assume that the peer will tell us if he recognizes ASCONF
258 * as part of INIT exchange.
259 * The sctp_addip_noauth option is there for backward compatibilty
260 * and will revert old behavior.
262 asoc
->peer
.asconf_capable
= 0;
263 if (net
->sctp
.addip_noauth
)
264 asoc
->peer
.asconf_capable
= 1;
265 asoc
->asconf_addr_del_pending
= NULL
;
266 asoc
->src_out_of_asoc_ok
= 0;
267 asoc
->new_transport
= NULL
;
269 /* Create an input queue. */
270 sctp_inq_init(&asoc
->base
.inqueue
);
271 sctp_inq_set_th_handler(&asoc
->base
.inqueue
, sctp_assoc_bh_rcv
);
273 /* Create an output queue. */
274 sctp_outq_init(asoc
, &asoc
->outqueue
);
276 if (!sctp_ulpq_init(&asoc
->ulpq
, asoc
))
279 memset(&asoc
->peer
.tsn_map
, 0, sizeof(struct sctp_tsnmap
));
285 /* Assume that peer would support both address types unless we are
288 asoc
->peer
.ipv4_address
= 1;
289 if (asoc
->base
.sk
->sk_family
== PF_INET6
)
290 asoc
->peer
.ipv6_address
= 1;
291 INIT_LIST_HEAD(&asoc
->asocs
);
293 asoc
->default_stream
= sp
->default_stream
;
294 asoc
->default_ppid
= sp
->default_ppid
;
295 asoc
->default_flags
= sp
->default_flags
;
296 asoc
->default_context
= sp
->default_context
;
297 asoc
->default_timetolive
= sp
->default_timetolive
;
298 asoc
->default_rcv_context
= sp
->default_rcv_context
;
300 /* SCTP_GET_ASSOC_STATS COUNTERS */
301 memset(&asoc
->stats
, 0, sizeof(struct sctp_priv_assoc_stats
));
303 /* AUTH related initializations */
304 INIT_LIST_HEAD(&asoc
->endpoint_shared_keys
);
305 err
= sctp_auth_asoc_copy_shkeys(ep
, asoc
, gfp
);
309 asoc
->active_key_id
= ep
->active_key_id
;
310 asoc
->asoc_shared_key
= NULL
;
312 asoc
->default_hmac_id
= 0;
313 /* Save the hmacs and chunks list into this association */
314 if (ep
->auth_hmacs_list
)
315 memcpy(asoc
->c
.auth_hmacs
, ep
->auth_hmacs_list
,
316 ntohs(ep
->auth_hmacs_list
->param_hdr
.length
));
317 if (ep
->auth_chunk_list
)
318 memcpy(asoc
->c
.auth_chunks
, ep
->auth_chunk_list
,
319 ntohs(ep
->auth_chunk_list
->param_hdr
.length
));
321 /* Get the AUTH random number for this association */
322 p
= (sctp_paramhdr_t
*)asoc
->c
.auth_random
;
323 p
->type
= SCTP_PARAM_RANDOM
;
324 p
->length
= htons(sizeof(sctp_paramhdr_t
) + SCTP_AUTH_RANDOM_LENGTH
);
325 get_random_bytes(p
+1, SCTP_AUTH_RANDOM_LENGTH
);
330 sock_put(asoc
->base
.sk
);
331 sctp_endpoint_put(asoc
->ep
);
335 /* Allocate and initialize a new association */
336 struct sctp_association
*sctp_association_new(const struct sctp_endpoint
*ep
,
337 const struct sock
*sk
,
341 struct sctp_association
*asoc
;
343 asoc
= kzalloc(sizeof(*asoc
), gfp
);
347 if (!sctp_association_init(asoc
, ep
, sk
, scope
, gfp
))
350 SCTP_DBG_OBJCNT_INC(assoc
);
352 pr_debug("Created asoc %p\n", asoc
);
362 /* Free this association if possible. There may still be users, so
363 * the actual deallocation may be delayed.
365 void sctp_association_free(struct sctp_association
*asoc
)
367 struct sock
*sk
= asoc
->base
.sk
;
368 struct sctp_transport
*transport
;
369 struct list_head
*pos
, *temp
;
372 /* Only real associations count against the endpoint, so
373 * don't bother for if this is a temporary association.
376 list_del(&asoc
->asocs
);
378 /* Decrement the backlog value for a TCP-style listening
381 if (sctp_style(sk
, TCP
) && sctp_sstate(sk
, LISTENING
))
382 sk
->sk_ack_backlog
--;
385 /* Mark as dead, so other users can know this structure is
388 asoc
->base
.dead
= true;
390 /* Dispose of any data lying around in the outqueue. */
391 sctp_outq_free(&asoc
->outqueue
);
393 /* Dispose of any pending messages for the upper layer. */
394 sctp_ulpq_free(&asoc
->ulpq
);
396 /* Dispose of any pending chunks on the inqueue. */
397 sctp_inq_free(&asoc
->base
.inqueue
);
399 sctp_tsnmap_free(&asoc
->peer
.tsn_map
);
401 /* Free ssnmap storage. */
402 sctp_ssnmap_free(asoc
->ssnmap
);
404 /* Clean up the bound address list. */
405 sctp_bind_addr_free(&asoc
->base
.bind_addr
);
407 /* Do we need to go through all of our timers and
408 * delete them? To be safe we will try to delete all, but we
409 * should be able to go through and make a guess based
412 for (i
= SCTP_EVENT_TIMEOUT_NONE
; i
< SCTP_NUM_TIMEOUT_TYPES
; ++i
) {
413 if (del_timer(&asoc
->timers
[i
]))
414 sctp_association_put(asoc
);
417 /* Free peer's cached cookie. */
418 kfree(asoc
->peer
.cookie
);
419 kfree(asoc
->peer
.peer_random
);
420 kfree(asoc
->peer
.peer_chunks
);
421 kfree(asoc
->peer
.peer_hmacs
);
423 /* Release the transport structures. */
424 list_for_each_safe(pos
, temp
, &asoc
->peer
.transport_addr_list
) {
425 transport
= list_entry(pos
, struct sctp_transport
, transports
);
427 sctp_transport_free(transport
);
430 asoc
->peer
.transport_count
= 0;
432 sctp_asconf_queue_teardown(asoc
);
434 /* Free pending address space being deleted */
435 if (asoc
->asconf_addr_del_pending
!= NULL
)
436 kfree(asoc
->asconf_addr_del_pending
);
438 /* AUTH - Free the endpoint shared keys */
439 sctp_auth_destroy_keys(&asoc
->endpoint_shared_keys
);
441 /* AUTH - Free the association shared key */
442 sctp_auth_key_put(asoc
->asoc_shared_key
);
444 sctp_association_put(asoc
);
447 /* Cleanup and free up an association. */
448 static void sctp_association_destroy(struct sctp_association
*asoc
)
450 if (unlikely(!asoc
->base
.dead
)) {
451 WARN(1, "Attempt to destroy undead association %p!\n", asoc
);
455 sctp_endpoint_put(asoc
->ep
);
456 sock_put(asoc
->base
.sk
);
458 if (asoc
->assoc_id
!= 0) {
459 spin_lock_bh(&sctp_assocs_id_lock
);
460 idr_remove(&sctp_assocs_id
, asoc
->assoc_id
);
461 spin_unlock_bh(&sctp_assocs_id_lock
);
464 WARN_ON(atomic_read(&asoc
->rmem_alloc
));
467 SCTP_DBG_OBJCNT_DEC(assoc
);
470 /* Change the primary destination address for the peer. */
471 void sctp_assoc_set_primary(struct sctp_association
*asoc
,
472 struct sctp_transport
*transport
)
476 /* it's a changeover only if we already have a primary path
477 * that we are changing
479 if (asoc
->peer
.primary_path
!= NULL
&&
480 asoc
->peer
.primary_path
!= transport
)
483 asoc
->peer
.primary_path
= transport
;
485 /* Set a default msg_name for events. */
486 memcpy(&asoc
->peer
.primary_addr
, &transport
->ipaddr
,
487 sizeof(union sctp_addr
));
489 /* If the primary path is changing, assume that the
490 * user wants to use this new path.
492 if ((transport
->state
== SCTP_ACTIVE
) ||
493 (transport
->state
== SCTP_UNKNOWN
))
494 asoc
->peer
.active_path
= transport
;
497 * SFR-CACC algorithm:
498 * Upon the receipt of a request to change the primary
499 * destination address, on the data structure for the new
500 * primary destination, the sender MUST do the following:
502 * 1) If CHANGEOVER_ACTIVE is set, then there was a switch
503 * to this destination address earlier. The sender MUST set
504 * CYCLING_CHANGEOVER to indicate that this switch is a
505 * double switch to the same destination address.
507 * Really, only bother is we have data queued or outstanding on
510 if (!asoc
->outqueue
.outstanding_bytes
&& !asoc
->outqueue
.out_qlen
)
513 if (transport
->cacc
.changeover_active
)
514 transport
->cacc
.cycling_changeover
= changeover
;
516 /* 2) The sender MUST set CHANGEOVER_ACTIVE to indicate that
517 * a changeover has occurred.
519 transport
->cacc
.changeover_active
= changeover
;
521 /* 3) The sender MUST store the next TSN to be sent in
522 * next_tsn_at_change.
524 transport
->cacc
.next_tsn_at_change
= asoc
->next_tsn
;
527 /* Remove a transport from an association. */
528 void sctp_assoc_rm_peer(struct sctp_association
*asoc
,
529 struct sctp_transport
*peer
)
531 struct list_head
*pos
;
532 struct sctp_transport
*transport
;
534 pr_debug("%s: association:%p addr:%pISpc\n",
535 __func__
, asoc
, &peer
->ipaddr
.sa
);
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_rcu(&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
.retran_path
== peer
)
556 asoc
->peer
.retran_path
= transport
;
557 if (asoc
->peer
.last_data_from
== peer
)
558 asoc
->peer
.last_data_from
= transport
;
560 /* If we remove the transport an INIT was last sent to, set it to
561 * NULL. Combined with the update of the retran path above, this
562 * will cause the next INIT to be sent to the next available
563 * transport, maintaining the cycle.
565 if (asoc
->init_last_sent_to
== peer
)
566 asoc
->init_last_sent_to
= NULL
;
568 /* If we remove the transport an SHUTDOWN was last sent to, set it
569 * to NULL. Combined with the update of the retran path above, this
570 * will cause the next SHUTDOWN to be sent to the next available
571 * transport, maintaining the cycle.
573 if (asoc
->shutdown_last_sent_to
== peer
)
574 asoc
->shutdown_last_sent_to
= NULL
;
576 /* If we remove the transport an ASCONF was last sent to, set it to
579 if (asoc
->addip_last_asconf
&&
580 asoc
->addip_last_asconf
->transport
== peer
)
581 asoc
->addip_last_asconf
->transport
= NULL
;
583 /* If we have something on the transmitted list, we have to
584 * save it off. The best place is the active path.
586 if (!list_empty(&peer
->transmitted
)) {
587 struct sctp_transport
*active
= asoc
->peer
.active_path
;
588 struct sctp_chunk
*ch
;
590 /* Reset the transport of each chunk on this list */
591 list_for_each_entry(ch
, &peer
->transmitted
,
593 ch
->transport
= NULL
;
594 ch
->rtt_in_progress
= 0;
597 list_splice_tail_init(&peer
->transmitted
,
598 &active
->transmitted
);
600 /* Start a T3 timer here in case it wasn't running so
601 * that these migrated packets have a chance to get
604 if (!timer_pending(&active
->T3_rtx_timer
))
605 if (!mod_timer(&active
->T3_rtx_timer
,
606 jiffies
+ active
->rto
))
607 sctp_transport_hold(active
);
610 asoc
->peer
.transport_count
--;
612 sctp_transport_free(peer
);
615 /* Add a transport address to an association. */
616 struct sctp_transport
*sctp_assoc_add_peer(struct sctp_association
*asoc
,
617 const union sctp_addr
*addr
,
619 const int peer_state
)
621 struct net
*net
= sock_net(asoc
->base
.sk
);
622 struct sctp_transport
*peer
;
623 struct sctp_sock
*sp
;
626 sp
= sctp_sk(asoc
->base
.sk
);
628 /* AF_INET and AF_INET6 share common port field. */
629 port
= ntohs(addr
->v4
.sin_port
);
631 pr_debug("%s: association:%p addr:%pISpc state:%d\n", __func__
,
632 asoc
, &addr
->sa
, peer_state
);
634 /* Set the port if it has not been set yet. */
635 if (0 == asoc
->peer
.port
)
636 asoc
->peer
.port
= port
;
638 /* Check to see if this is a duplicate. */
639 peer
= sctp_assoc_lookup_paddr(asoc
, addr
);
641 /* An UNKNOWN state is only set on transports added by
642 * user in sctp_connectx() call. Such transports should be
643 * considered CONFIRMED per RFC 4960, Section 5.4.
645 if (peer
->state
== SCTP_UNKNOWN
) {
646 peer
->state
= SCTP_ACTIVE
;
651 peer
= sctp_transport_new(net
, addr
, gfp
);
655 sctp_transport_set_owner(peer
, asoc
);
657 /* Initialize the peer's heartbeat interval based on the
658 * association configured value.
660 peer
->hbinterval
= asoc
->hbinterval
;
662 /* Set the path max_retrans. */
663 peer
->pathmaxrxt
= asoc
->pathmaxrxt
;
665 /* And the partial failure retrans threshold */
666 peer
->pf_retrans
= asoc
->pf_retrans
;
668 /* Initialize the peer's SACK delay timeout based on the
669 * association configured value.
671 peer
->sackdelay
= asoc
->sackdelay
;
672 peer
->sackfreq
= asoc
->sackfreq
;
674 /* Enable/disable heartbeat, SACK delay, and path MTU discovery
675 * based on association setting.
677 peer
->param_flags
= asoc
->param_flags
;
679 sctp_transport_route(peer
, NULL
, sp
);
681 /* Initialize the pmtu of the transport. */
682 if (peer
->param_flags
& SPP_PMTUD_DISABLE
) {
684 peer
->pathmtu
= asoc
->pathmtu
;
686 peer
->pathmtu
= SCTP_DEFAULT_MAXSEGMENT
;
689 /* If this is the first transport addr on this association,
690 * initialize the association PMTU to the peer's PMTU.
691 * If not and the current association PMTU is higher than the new
692 * peer's PMTU, reset the association PMTU to the new peer's PMTU.
695 asoc
->pathmtu
= min_t(int, peer
->pathmtu
, asoc
->pathmtu
);
697 asoc
->pathmtu
= peer
->pathmtu
;
699 pr_debug("%s: association:%p PMTU set to %d\n", __func__
, asoc
,
702 peer
->pmtu_pending
= 0;
704 asoc
->frag_point
= sctp_frag_point(asoc
, asoc
->pathmtu
);
706 /* The asoc->peer.port might not be meaningful yet, but
707 * initialize the packet structure anyway.
709 sctp_packet_init(&peer
->packet
, peer
, asoc
->base
.bind_addr
.port
,
714 * o The initial cwnd before DATA transmission or after a sufficiently
715 * long idle period MUST be set to
716 * min(4*MTU, max(2*MTU, 4380 bytes))
718 * o The initial value of ssthresh MAY be arbitrarily high
719 * (for example, implementations MAY use the size of the
720 * receiver advertised window).
722 peer
->cwnd
= min(4*asoc
->pathmtu
, max_t(__u32
, 2*asoc
->pathmtu
, 4380));
724 /* At this point, we may not have the receiver's advertised window,
725 * so initialize ssthresh to the default value and it will be set
726 * later when we process the INIT.
728 peer
->ssthresh
= SCTP_DEFAULT_MAXWINDOW
;
730 peer
->partial_bytes_acked
= 0;
731 peer
->flight_size
= 0;
732 peer
->burst_limited
= 0;
734 /* Set the transport's RTO.initial value */
735 peer
->rto
= asoc
->rto_initial
;
736 sctp_max_rto(asoc
, peer
);
738 /* Set the peer's active state. */
739 peer
->state
= peer_state
;
741 /* Attach the remote transport to our asoc. */
742 list_add_tail_rcu(&peer
->transports
, &asoc
->peer
.transport_addr_list
);
743 asoc
->peer
.transport_count
++;
745 /* If we do not yet have a primary path, set one. */
746 if (!asoc
->peer
.primary_path
) {
747 sctp_assoc_set_primary(asoc
, peer
);
748 asoc
->peer
.retran_path
= peer
;
751 if (asoc
->peer
.active_path
== asoc
->peer
.retran_path
&&
752 peer
->state
!= SCTP_UNCONFIRMED
) {
753 asoc
->peer
.retran_path
= peer
;
759 /* Delete a transport address from an association. */
760 void sctp_assoc_del_peer(struct sctp_association
*asoc
,
761 const union sctp_addr
*addr
)
763 struct list_head
*pos
;
764 struct list_head
*temp
;
765 struct sctp_transport
*transport
;
767 list_for_each_safe(pos
, temp
, &asoc
->peer
.transport_addr_list
) {
768 transport
= list_entry(pos
, struct sctp_transport
, transports
);
769 if (sctp_cmp_addr_exact(addr
, &transport
->ipaddr
)) {
770 /* Do book keeping for removing the peer and free it. */
771 sctp_assoc_rm_peer(asoc
, transport
);
777 /* Lookup a transport by address. */
778 struct sctp_transport
*sctp_assoc_lookup_paddr(
779 const struct sctp_association
*asoc
,
780 const union sctp_addr
*address
)
782 struct sctp_transport
*t
;
784 /* Cycle through all transports searching for a peer address. */
786 list_for_each_entry(t
, &asoc
->peer
.transport_addr_list
,
788 if (sctp_cmp_addr_exact(address
, &t
->ipaddr
))
795 /* Remove all transports except a give one */
796 void sctp_assoc_del_nonprimary_peers(struct sctp_association
*asoc
,
797 struct sctp_transport
*primary
)
799 struct sctp_transport
*temp
;
800 struct sctp_transport
*t
;
802 list_for_each_entry_safe(t
, temp
, &asoc
->peer
.transport_addr_list
,
804 /* if the current transport is not the primary one, delete it */
806 sctp_assoc_rm_peer(asoc
, t
);
810 /* Engage in transport control operations.
811 * Mark the transport up or down and send a notification to the user.
812 * Select and update the new active and retran paths.
814 void sctp_assoc_control_transport(struct sctp_association
*asoc
,
815 struct sctp_transport
*transport
,
816 sctp_transport_cmd_t command
,
817 sctp_sn_error_t error
)
819 struct sctp_transport
*t
= NULL
;
820 struct sctp_transport
*first
;
821 struct sctp_transport
*second
;
822 struct sctp_ulpevent
*event
;
823 struct sockaddr_storage addr
;
825 bool ulp_notify
= true;
827 /* Record the transition on the transport. */
829 case SCTP_TRANSPORT_UP
:
830 /* If we are moving from UNCONFIRMED state due
831 * to heartbeat success, report the SCTP_ADDR_CONFIRMED
832 * state to the user, otherwise report SCTP_ADDR_AVAILABLE.
834 if (SCTP_UNCONFIRMED
== transport
->state
&&
835 SCTP_HEARTBEAT_SUCCESS
== error
)
836 spc_state
= SCTP_ADDR_CONFIRMED
;
838 spc_state
= SCTP_ADDR_AVAILABLE
;
839 /* Don't inform ULP about transition from PF to
840 * active state and set cwnd to 1 MTU, see SCTP
841 * Quick failover draft section 5.1, point 5
843 if (transport
->state
== SCTP_PF
) {
845 transport
->cwnd
= asoc
->pathmtu
;
847 transport
->state
= SCTP_ACTIVE
;
850 case SCTP_TRANSPORT_DOWN
:
851 /* If the transport was never confirmed, do not transition it
852 * to inactive state. Also, release the cached route since
853 * there may be a better route next time.
855 if (transport
->state
!= SCTP_UNCONFIRMED
)
856 transport
->state
= SCTP_INACTIVE
;
858 dst_release(transport
->dst
);
859 transport
->dst
= NULL
;
862 spc_state
= SCTP_ADDR_UNREACHABLE
;
865 case SCTP_TRANSPORT_PF
:
866 transport
->state
= SCTP_PF
;
874 /* Generate and send a SCTP_PEER_ADDR_CHANGE notification to the
878 memset(&addr
, 0, sizeof(struct sockaddr_storage
));
879 memcpy(&addr
, &transport
->ipaddr
,
880 transport
->af_specific
->sockaddr_len
);
881 event
= sctp_ulpevent_make_peer_addr_change(asoc
, &addr
,
882 0, spc_state
, error
, GFP_ATOMIC
);
884 sctp_ulpq_tail_event(&asoc
->ulpq
, event
);
887 /* Select new active and retran paths. */
889 /* Look for the two most recently used active transports.
891 * This code produces the wrong ordering whenever jiffies
892 * rolls over, but we still get usable transports, so we don't
895 first
= NULL
; second
= NULL
;
897 list_for_each_entry(t
, &asoc
->peer
.transport_addr_list
,
900 if ((t
->state
== SCTP_INACTIVE
) ||
901 (t
->state
== SCTP_UNCONFIRMED
) ||
902 (t
->state
== SCTP_PF
))
904 if (!first
|| t
->last_time_heard
> first
->last_time_heard
) {
907 } else if (!second
||
908 t
->last_time_heard
> second
->last_time_heard
)
912 /* RFC 2960 6.4 Multi-Homed SCTP Endpoints
914 * By default, an endpoint should always transmit to the
915 * primary path, unless the SCTP user explicitly specifies the
916 * destination transport address (and possibly source
917 * transport address) to use.
919 * [If the primary is active but not most recent, bump the most
920 * recently used transport.]
922 if (((asoc
->peer
.primary_path
->state
== SCTP_ACTIVE
) ||
923 (asoc
->peer
.primary_path
->state
== SCTP_UNKNOWN
)) &&
924 first
!= asoc
->peer
.primary_path
) {
926 first
= asoc
->peer
.primary_path
;
931 /* If we failed to find a usable transport, just camp on the
932 * primary, even if it is inactive.
935 first
= asoc
->peer
.primary_path
;
936 second
= asoc
->peer
.primary_path
;
939 /* Set the active and retran transports. */
940 asoc
->peer
.active_path
= first
;
941 asoc
->peer
.retran_path
= second
;
944 /* Hold a reference to an association. */
945 void sctp_association_hold(struct sctp_association
*asoc
)
947 atomic_inc(&asoc
->base
.refcnt
);
950 /* Release a reference to an association and cleanup
951 * if there are no more references.
953 void sctp_association_put(struct sctp_association
*asoc
)
955 if (atomic_dec_and_test(&asoc
->base
.refcnt
))
956 sctp_association_destroy(asoc
);
959 /* Allocate the next TSN, Transmission Sequence Number, for the given
962 __u32
sctp_association_get_next_tsn(struct sctp_association
*asoc
)
964 /* From Section 1.6 Serial Number Arithmetic:
965 * Transmission Sequence Numbers wrap around when they reach
966 * 2**32 - 1. That is, the next TSN a DATA chunk MUST use
967 * after transmitting TSN = 2*32 - 1 is TSN = 0.
969 __u32 retval
= asoc
->next_tsn
;
976 /* Compare two addresses to see if they match. Wildcard addresses
977 * only match themselves.
979 int sctp_cmp_addr_exact(const union sctp_addr
*ss1
,
980 const union sctp_addr
*ss2
)
984 af
= sctp_get_af_specific(ss1
->sa
.sa_family
);
988 return af
->cmp_addr(ss1
, ss2
);
991 /* Return an ecne chunk to get prepended to a packet.
992 * Note: We are sly and return a shared, prealloced chunk. FIXME:
993 * No we don't, but we could/should.
995 struct sctp_chunk
*sctp_get_ecne_prepend(struct sctp_association
*asoc
)
997 struct sctp_chunk
*chunk
;
999 /* Send ECNE if needed.
1000 * Not being able to allocate a chunk here is not deadly.
1002 if (asoc
->need_ecne
)
1003 chunk
= sctp_make_ecne(asoc
, asoc
->last_ecne_tsn
);
1011 * Find which transport this TSN was sent on.
1013 struct sctp_transport
*sctp_assoc_lookup_tsn(struct sctp_association
*asoc
,
1016 struct sctp_transport
*active
;
1017 struct sctp_transport
*match
;
1018 struct sctp_transport
*transport
;
1019 struct sctp_chunk
*chunk
;
1020 __be32 key
= htonl(tsn
);
1025 * FIXME: In general, find a more efficient data structure for
1030 * The general strategy is to search each transport's transmitted
1031 * list. Return which transport this TSN lives on.
1033 * Let's be hopeful and check the active_path first.
1034 * Another optimization would be to know if there is only one
1035 * outbound path and not have to look for the TSN at all.
1039 active
= asoc
->peer
.active_path
;
1041 list_for_each_entry(chunk
, &active
->transmitted
,
1044 if (key
== chunk
->subh
.data_hdr
->tsn
) {
1050 /* If not found, go search all the other transports. */
1051 list_for_each_entry(transport
, &asoc
->peer
.transport_addr_list
,
1054 if (transport
== active
)
1056 list_for_each_entry(chunk
, &transport
->transmitted
,
1058 if (key
== chunk
->subh
.data_hdr
->tsn
) {
1068 /* Is this the association we are looking for? */
1069 struct sctp_transport
*sctp_assoc_is_match(struct sctp_association
*asoc
,
1071 const union sctp_addr
*laddr
,
1072 const union sctp_addr
*paddr
)
1074 struct sctp_transport
*transport
;
1076 if ((htons(asoc
->base
.bind_addr
.port
) == laddr
->v4
.sin_port
) &&
1077 (htons(asoc
->peer
.port
) == paddr
->v4
.sin_port
) &&
1078 net_eq(sock_net(asoc
->base
.sk
), net
)) {
1079 transport
= sctp_assoc_lookup_paddr(asoc
, paddr
);
1083 if (sctp_bind_addr_match(&asoc
->base
.bind_addr
, laddr
,
1084 sctp_sk(asoc
->base
.sk
)))
1093 /* Do delayed input processing. This is scheduled by sctp_rcv(). */
1094 static void sctp_assoc_bh_rcv(struct work_struct
*work
)
1096 struct sctp_association
*asoc
=
1097 container_of(work
, struct sctp_association
,
1098 base
.inqueue
.immediate
);
1099 struct net
*net
= sock_net(asoc
->base
.sk
);
1100 struct sctp_endpoint
*ep
;
1101 struct sctp_chunk
*chunk
;
1102 struct sctp_inq
*inqueue
;
1104 sctp_subtype_t subtype
;
1107 /* The association should be held so we should be safe. */
1110 inqueue
= &asoc
->base
.inqueue
;
1111 sctp_association_hold(asoc
);
1112 while (NULL
!= (chunk
= sctp_inq_pop(inqueue
))) {
1113 state
= asoc
->state
;
1114 subtype
= SCTP_ST_CHUNK(chunk
->chunk_hdr
->type
);
1116 /* SCTP-AUTH, Section 6.3:
1117 * The receiver has a list of chunk types which it expects
1118 * to be received only after an AUTH-chunk. This list has
1119 * been sent to the peer during the association setup. It
1120 * MUST silently discard these chunks if they are not placed
1121 * after an AUTH chunk in the packet.
1123 if (sctp_auth_recv_cid(subtype
.chunk
, asoc
) && !chunk
->auth
)
1126 /* Remember where the last DATA chunk came from so we
1127 * know where to send the SACK.
1129 if (sctp_chunk_is_data(chunk
))
1130 asoc
->peer
.last_data_from
= chunk
->transport
;
1132 SCTP_INC_STATS(net
, SCTP_MIB_INCTRLCHUNKS
);
1133 asoc
->stats
.ictrlchunks
++;
1134 if (chunk
->chunk_hdr
->type
== SCTP_CID_SACK
)
1135 asoc
->stats
.isacks
++;
1138 if (chunk
->transport
)
1139 chunk
->transport
->last_time_heard
= jiffies
;
1141 /* Run through the state machine. */
1142 error
= sctp_do_sm(net
, SCTP_EVENT_T_CHUNK
, subtype
,
1143 state
, ep
, asoc
, chunk
, GFP_ATOMIC
);
1145 /* Check to see if the association is freed in response to
1146 * the incoming chunk. If so, get out of the while loop.
1148 if (asoc
->base
.dead
)
1151 /* If there is an error on chunk, discard this packet. */
1153 chunk
->pdiscard
= 1;
1155 sctp_association_put(asoc
);
1158 /* This routine moves an association from its old sk to a new sk. */
1159 void sctp_assoc_migrate(struct sctp_association
*assoc
, struct sock
*newsk
)
1161 struct sctp_sock
*newsp
= sctp_sk(newsk
);
1162 struct sock
*oldsk
= assoc
->base
.sk
;
1164 /* Delete the association from the old endpoint's list of
1167 list_del_init(&assoc
->asocs
);
1169 /* Decrement the backlog value for a TCP-style socket. */
1170 if (sctp_style(oldsk
, TCP
))
1171 oldsk
->sk_ack_backlog
--;
1173 /* Release references to the old endpoint and the sock. */
1174 sctp_endpoint_put(assoc
->ep
);
1175 sock_put(assoc
->base
.sk
);
1177 /* Get a reference to the new endpoint. */
1178 assoc
->ep
= newsp
->ep
;
1179 sctp_endpoint_hold(assoc
->ep
);
1181 /* Get a reference to the new sock. */
1182 assoc
->base
.sk
= newsk
;
1183 sock_hold(assoc
->base
.sk
);
1185 /* Add the association to the new endpoint's list of associations. */
1186 sctp_endpoint_add_asoc(newsp
->ep
, assoc
);
1189 /* Update an association (possibly from unexpected COOKIE-ECHO processing). */
1190 void sctp_assoc_update(struct sctp_association
*asoc
,
1191 struct sctp_association
*new)
1193 struct sctp_transport
*trans
;
1194 struct list_head
*pos
, *temp
;
1196 /* Copy in new parameters of peer. */
1198 asoc
->peer
.rwnd
= new->peer
.rwnd
;
1199 asoc
->peer
.sack_needed
= new->peer
.sack_needed
;
1200 asoc
->peer
.i
= new->peer
.i
;
1201 sctp_tsnmap_init(&asoc
->peer
.tsn_map
, SCTP_TSN_MAP_INITIAL
,
1202 asoc
->peer
.i
.initial_tsn
, GFP_ATOMIC
);
1204 /* Remove any peer addresses not present in the new association. */
1205 list_for_each_safe(pos
, temp
, &asoc
->peer
.transport_addr_list
) {
1206 trans
= list_entry(pos
, struct sctp_transport
, transports
);
1207 if (!sctp_assoc_lookup_paddr(new, &trans
->ipaddr
)) {
1208 sctp_assoc_rm_peer(asoc
, trans
);
1212 if (asoc
->state
>= SCTP_STATE_ESTABLISHED
)
1213 sctp_transport_reset(trans
);
1216 /* If the case is A (association restart), use
1217 * initial_tsn as next_tsn. If the case is B, use
1218 * current next_tsn in case data sent to peer
1219 * has been discarded and needs retransmission.
1221 if (asoc
->state
>= SCTP_STATE_ESTABLISHED
) {
1222 asoc
->next_tsn
= new->next_tsn
;
1223 asoc
->ctsn_ack_point
= new->ctsn_ack_point
;
1224 asoc
->adv_peer_ack_point
= new->adv_peer_ack_point
;
1226 /* Reinitialize SSN for both local streams
1227 * and peer's streams.
1229 sctp_ssnmap_clear(asoc
->ssnmap
);
1231 /* Flush the ULP reassembly and ordered queue.
1232 * Any data there will now be stale and will
1235 sctp_ulpq_flush(&asoc
->ulpq
);
1237 /* reset the overall association error count so
1238 * that the restarted association doesn't get torn
1239 * down on the next retransmission timer.
1241 asoc
->overall_error_count
= 0;
1244 /* Add any peer addresses from the new association. */
1245 list_for_each_entry(trans
, &new->peer
.transport_addr_list
,
1247 if (!sctp_assoc_lookup_paddr(asoc
, &trans
->ipaddr
))
1248 sctp_assoc_add_peer(asoc
, &trans
->ipaddr
,
1249 GFP_ATOMIC
, trans
->state
);
1252 asoc
->ctsn_ack_point
= asoc
->next_tsn
- 1;
1253 asoc
->adv_peer_ack_point
= asoc
->ctsn_ack_point
;
1254 if (!asoc
->ssnmap
) {
1255 /* Move the ssnmap. */
1256 asoc
->ssnmap
= new->ssnmap
;
1260 if (!asoc
->assoc_id
) {
1261 /* get a new association id since we don't have one
1264 sctp_assoc_set_id(asoc
, GFP_ATOMIC
);
1268 /* SCTP-AUTH: Save the peer parameters from the new assocaitions
1269 * and also move the association shared keys over
1271 kfree(asoc
->peer
.peer_random
);
1272 asoc
->peer
.peer_random
= new->peer
.peer_random
;
1273 new->peer
.peer_random
= NULL
;
1275 kfree(asoc
->peer
.peer_chunks
);
1276 asoc
->peer
.peer_chunks
= new->peer
.peer_chunks
;
1277 new->peer
.peer_chunks
= NULL
;
1279 kfree(asoc
->peer
.peer_hmacs
);
1280 asoc
->peer
.peer_hmacs
= new->peer
.peer_hmacs
;
1281 new->peer
.peer_hmacs
= NULL
;
1283 sctp_auth_key_put(asoc
->asoc_shared_key
);
1284 sctp_auth_asoc_init_active_key(asoc
, GFP_ATOMIC
);
1287 /* Update the retran path for sending a retransmitted packet.
1288 * Round-robin through the active transports, else round-robin
1289 * through the inactive transports as this is the next best thing
1292 void sctp_assoc_update_retran_path(struct sctp_association
*asoc
)
1294 struct sctp_transport
*t
, *next
;
1295 struct list_head
*head
= &asoc
->peer
.transport_addr_list
;
1296 struct list_head
*pos
;
1298 if (asoc
->peer
.transport_count
== 1)
1301 /* Find the next transport in a round-robin fashion. */
1302 t
= asoc
->peer
.retran_path
;
1303 pos
= &t
->transports
;
1307 /* Skip the head. */
1308 if (pos
->next
== head
)
1313 t
= list_entry(pos
, struct sctp_transport
, transports
);
1315 /* We have exhausted the list, but didn't find any
1316 * other active transports. If so, use the next
1319 if (t
== asoc
->peer
.retran_path
) {
1324 /* Try to find an active transport. */
1326 if ((t
->state
== SCTP_ACTIVE
) ||
1327 (t
->state
== SCTP_UNKNOWN
)) {
1330 /* Keep track of the next transport in case
1331 * we don't find any active transport.
1333 if (t
->state
!= SCTP_UNCONFIRMED
&& !next
)
1339 asoc
->peer
.retran_path
= t
;
1341 t
= asoc
->peer
.retran_path
;
1343 pr_debug("%s: association:%p addr:%pISpc\n", __func__
, asoc
,
1347 /* Choose the transport for sending retransmit packet. */
1348 struct sctp_transport
*sctp_assoc_choose_alter_transport(
1349 struct sctp_association
*asoc
, struct sctp_transport
*last_sent_to
)
1351 /* If this is the first time packet is sent, use the active path,
1352 * else use the retran path. If the last packet was sent over the
1353 * retran path, update the retran path and use it.
1356 return asoc
->peer
.active_path
;
1358 if (last_sent_to
== asoc
->peer
.retran_path
)
1359 sctp_assoc_update_retran_path(asoc
);
1360 return asoc
->peer
.retran_path
;
1364 /* Update the association's pmtu and frag_point by going through all the
1365 * transports. This routine is called when a transport's PMTU has changed.
1367 void sctp_assoc_sync_pmtu(struct sock
*sk
, struct sctp_association
*asoc
)
1369 struct sctp_transport
*t
;
1375 /* Get the lowest pmtu of all the transports. */
1376 list_for_each_entry(t
, &asoc
->peer
.transport_addr_list
,
1378 if (t
->pmtu_pending
&& t
->dst
) {
1379 sctp_transport_update_pmtu(sk
, t
, dst_mtu(t
->dst
));
1380 t
->pmtu_pending
= 0;
1382 if (!pmtu
|| (t
->pathmtu
< pmtu
))
1387 asoc
->pathmtu
= pmtu
;
1388 asoc
->frag_point
= sctp_frag_point(asoc
, pmtu
);
1391 pr_debug("%s: asoc:%p, pmtu:%d, frag_point:%d\n", __func__
, asoc
,
1392 asoc
->pathmtu
, asoc
->frag_point
);
1395 /* Should we send a SACK to update our peer? */
1396 static inline int sctp_peer_needs_update(struct sctp_association
*asoc
)
1398 struct net
*net
= sock_net(asoc
->base
.sk
);
1399 switch (asoc
->state
) {
1400 case SCTP_STATE_ESTABLISHED
:
1401 case SCTP_STATE_SHUTDOWN_PENDING
:
1402 case SCTP_STATE_SHUTDOWN_RECEIVED
:
1403 case SCTP_STATE_SHUTDOWN_SENT
:
1404 if ((asoc
->rwnd
> asoc
->a_rwnd
) &&
1405 ((asoc
->rwnd
- asoc
->a_rwnd
) >= max_t(__u32
,
1406 (asoc
->base
.sk
->sk_rcvbuf
>> net
->sctp
.rwnd_upd_shift
),
1416 /* Increase asoc's rwnd by len and send any window update SACK if needed. */
1417 void sctp_assoc_rwnd_increase(struct sctp_association
*asoc
, unsigned int len
)
1419 struct sctp_chunk
*sack
;
1420 struct timer_list
*timer
;
1422 if (asoc
->rwnd_over
) {
1423 if (asoc
->rwnd_over
>= len
) {
1424 asoc
->rwnd_over
-= len
;
1426 asoc
->rwnd
+= (len
- asoc
->rwnd_over
);
1427 asoc
->rwnd_over
= 0;
1433 /* If we had window pressure, start recovering it
1434 * once our rwnd had reached the accumulated pressure
1435 * threshold. The idea is to recover slowly, but up
1436 * to the initial advertised window.
1438 if (asoc
->rwnd_press
&& asoc
->rwnd
>= asoc
->rwnd_press
) {
1439 int change
= min(asoc
->pathmtu
, asoc
->rwnd_press
);
1440 asoc
->rwnd
+= change
;
1441 asoc
->rwnd_press
-= change
;
1444 pr_debug("%s: asoc:%p rwnd increased by %d to (%u, %u) - %u\n",
1445 __func__
, asoc
, len
, asoc
->rwnd
, asoc
->rwnd_over
,
1448 /* Send a window update SACK if the rwnd has increased by at least the
1449 * minimum of the association's PMTU and half of the receive buffer.
1450 * The algorithm used is similar to the one described in
1451 * Section 4.2.3.3 of RFC 1122.
1453 if (sctp_peer_needs_update(asoc
)) {
1454 asoc
->a_rwnd
= asoc
->rwnd
;
1456 pr_debug("%s: sending window update SACK- asoc:%p rwnd:%u "
1457 "a_rwnd:%u\n", __func__
, asoc
, asoc
->rwnd
,
1460 sack
= sctp_make_sack(asoc
);
1464 asoc
->peer
.sack_needed
= 0;
1466 sctp_outq_tail(&asoc
->outqueue
, sack
);
1468 /* Stop the SACK timer. */
1469 timer
= &asoc
->timers
[SCTP_EVENT_TIMEOUT_SACK
];
1470 if (del_timer(timer
))
1471 sctp_association_put(asoc
);
1475 /* Decrease asoc's rwnd by len. */
1476 void sctp_assoc_rwnd_decrease(struct sctp_association
*asoc
, unsigned int len
)
1481 if (unlikely(!asoc
->rwnd
|| asoc
->rwnd_over
))
1482 pr_debug("%s: association:%p has asoc->rwnd:%u, "
1483 "asoc->rwnd_over:%u!\n", __func__
, asoc
,
1484 asoc
->rwnd
, asoc
->rwnd_over
);
1486 if (asoc
->ep
->rcvbuf_policy
)
1487 rx_count
= atomic_read(&asoc
->rmem_alloc
);
1489 rx_count
= atomic_read(&asoc
->base
.sk
->sk_rmem_alloc
);
1491 /* If we've reached or overflowed our receive buffer, announce
1492 * a 0 rwnd if rwnd would still be positive. Store the
1493 * the pottential pressure overflow so that the window can be restored
1494 * back to original value.
1496 if (rx_count
>= asoc
->base
.sk
->sk_rcvbuf
)
1499 if (asoc
->rwnd
>= len
) {
1502 asoc
->rwnd_press
+= asoc
->rwnd
;
1506 asoc
->rwnd_over
= len
- asoc
->rwnd
;
1510 pr_debug("%s: asoc:%p rwnd decreased by %d to (%u, %u, %u)\n",
1511 __func__
, asoc
, len
, asoc
->rwnd
, asoc
->rwnd_over
,
1515 /* Build the bind address list for the association based on info from the
1516 * local endpoint and the remote peer.
1518 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association
*asoc
,
1519 sctp_scope_t scope
, gfp_t gfp
)
1523 /* Use scoping rules to determine the subset of addresses from
1526 flags
= (PF_INET6
== asoc
->base
.sk
->sk_family
) ? SCTP_ADDR6_ALLOWED
: 0;
1527 if (asoc
->peer
.ipv4_address
)
1528 flags
|= SCTP_ADDR4_PEERSUPP
;
1529 if (asoc
->peer
.ipv6_address
)
1530 flags
|= SCTP_ADDR6_PEERSUPP
;
1532 return sctp_bind_addr_copy(sock_net(asoc
->base
.sk
),
1533 &asoc
->base
.bind_addr
,
1534 &asoc
->ep
->base
.bind_addr
,
1538 /* Build the association's bind address list from the cookie. */
1539 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association
*asoc
,
1540 struct sctp_cookie
*cookie
,
1543 int var_size2
= ntohs(cookie
->peer_init
->chunk_hdr
.length
);
1544 int var_size3
= cookie
->raw_addr_list_len
;
1545 __u8
*raw
= (__u8
*)cookie
->peer_init
+ var_size2
;
1547 return sctp_raw_to_bind_addrs(&asoc
->base
.bind_addr
, raw
, var_size3
,
1548 asoc
->ep
->base
.bind_addr
.port
, gfp
);
1551 /* Lookup laddr in the bind address list of an association. */
1552 int sctp_assoc_lookup_laddr(struct sctp_association
*asoc
,
1553 const union sctp_addr
*laddr
)
1557 if ((asoc
->base
.bind_addr
.port
== ntohs(laddr
->v4
.sin_port
)) &&
1558 sctp_bind_addr_match(&asoc
->base
.bind_addr
, laddr
,
1559 sctp_sk(asoc
->base
.sk
)))
1565 /* Set an association id for a given association */
1566 int sctp_assoc_set_id(struct sctp_association
*asoc
, gfp_t gfp
)
1568 bool preload
= gfp
& __GFP_WAIT
;
1571 /* If the id is already assigned, keep it. */
1577 spin_lock_bh(&sctp_assocs_id_lock
);
1578 /* 0 is not a valid assoc_id, must be >= 1 */
1579 ret
= idr_alloc_cyclic(&sctp_assocs_id
, asoc
, 1, 0, GFP_NOWAIT
);
1580 spin_unlock_bh(&sctp_assocs_id_lock
);
1586 asoc
->assoc_id
= (sctp_assoc_t
)ret
;
1590 /* Free the ASCONF queue */
1591 static void sctp_assoc_free_asconf_queue(struct sctp_association
*asoc
)
1593 struct sctp_chunk
*asconf
;
1594 struct sctp_chunk
*tmp
;
1596 list_for_each_entry_safe(asconf
, tmp
, &asoc
->addip_chunk_list
, list
) {
1597 list_del_init(&asconf
->list
);
1598 sctp_chunk_free(asconf
);
1602 /* Free asconf_ack cache */
1603 static void sctp_assoc_free_asconf_acks(struct sctp_association
*asoc
)
1605 struct sctp_chunk
*ack
;
1606 struct sctp_chunk
*tmp
;
1608 list_for_each_entry_safe(ack
, tmp
, &asoc
->asconf_ack_list
,
1610 list_del_init(&ack
->transmitted_list
);
1611 sctp_chunk_free(ack
);
1615 /* Clean up the ASCONF_ACK queue */
1616 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association
*asoc
)
1618 struct sctp_chunk
*ack
;
1619 struct sctp_chunk
*tmp
;
1621 /* We can remove all the entries from the queue up to
1622 * the "Peer-Sequence-Number".
1624 list_for_each_entry_safe(ack
, tmp
, &asoc
->asconf_ack_list
,
1626 if (ack
->subh
.addip_hdr
->serial
==
1627 htonl(asoc
->peer
.addip_serial
))
1630 list_del_init(&ack
->transmitted_list
);
1631 sctp_chunk_free(ack
);
1635 /* Find the ASCONF_ACK whose serial number matches ASCONF */
1636 struct sctp_chunk
*sctp_assoc_lookup_asconf_ack(
1637 const struct sctp_association
*asoc
,
1640 struct sctp_chunk
*ack
;
1642 /* Walk through the list of cached ASCONF-ACKs and find the
1643 * ack chunk whose serial number matches that of the request.
1645 list_for_each_entry(ack
, &asoc
->asconf_ack_list
, transmitted_list
) {
1646 if (ack
->subh
.addip_hdr
->serial
== serial
) {
1647 sctp_chunk_hold(ack
);
1655 void sctp_asconf_queue_teardown(struct sctp_association
*asoc
)
1657 /* Free any cached ASCONF_ACK chunk. */
1658 sctp_assoc_free_asconf_acks(asoc
);
1660 /* Free the ASCONF queue. */
1661 sctp_assoc_free_asconf_queue(asoc
);
1663 /* Free any cached ASCONF chunk. */
1664 if (asoc
->addip_last_asconf
)
1665 sctp_chunk_free(asoc
->addip_last_asconf
);