1 /* SCTP kernel implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999-2000 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 * Copyright (c) 2001 Intel Corp.
6 * Copyright (c) 2001 La Monte H.P. Yarroll
8 * This file is part of the SCTP kernel implementation
10 * This module provides the abstraction for an SCTP association.
12 * This SCTP implementation is free software;
13 * you can redistribute it and/or modify it under the terms of
14 * the GNU General Public License as published by
15 * the Free Software Foundation; either version 2, or (at your option)
18 * This SCTP implementation is distributed in the hope that it
19 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
20 * ************************
21 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
22 * See the GNU General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with GNU CC; see the file COPYING. If not, write to
26 * the Free Software Foundation, 59 Temple Place - Suite 330,
27 * Boston, MA 02111-1307, USA.
29 * Please send any bug reports or fixes you make to the
31 * lksctp developers <lksctp-developers@lists.sourceforge.net>
33 * Or submit a bug report through the following website:
34 * http://www.sf.net/projects/lksctp
36 * Written or modified by:
37 * La Monte H.P. Yarroll <piggy@acm.org>
38 * Karl Knutson <karl@athena.chicago.il.us>
39 * Jon Grimm <jgrimm@us.ibm.com>
40 * Xingang Guo <xingang.guo@intel.com>
41 * Hui Huang <hui.huang@nokia.com>
42 * Sridhar Samudrala <sri@us.ibm.com>
43 * Daisy Chang <daisyc@us.ibm.com>
44 * Ryan Layer <rmlayer@us.ibm.com>
45 * Kevin Gao <kevin.gao@intel.com>
47 * Any bugs reported given to us we will try to fix... any fixes shared will
48 * be incorporated into the next SCTP release.
51 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
53 #include <linux/types.h>
54 #include <linux/fcntl.h>
55 #include <linux/poll.h>
56 #include <linux/init.h>
58 #include <linux/slab.h>
61 #include <net/sctp/sctp.h>
62 #include <net/sctp/sm.h>
64 /* Forward declarations for internal functions. */
65 static void sctp_assoc_bh_rcv(struct work_struct
*work
);
66 static void sctp_assoc_free_asconf_acks(struct sctp_association
*asoc
);
67 static void sctp_assoc_free_asconf_queue(struct sctp_association
*asoc
);
69 /* Keep track of the new idr low so that we don't re-use association id
70 * numbers too fast. It is protected by they idr spin lock is in the
71 * range of 1 - INT_MAX.
73 static u32 idr_low
= 1;
76 /* 1st Level Abstractions. */
78 /* Initialize a new association from provided memory. */
79 static struct sctp_association
*sctp_association_init(struct sctp_association
*asoc
,
80 const struct sctp_endpoint
*ep
,
81 const struct sock
*sk
,
90 /* Retrieve the SCTP per socket area. */
91 sp
= sctp_sk((struct sock
*)sk
);
93 /* Discarding const is appropriate here. */
94 asoc
->ep
= (struct sctp_endpoint
*)ep
;
95 sctp_endpoint_hold(asoc
->ep
);
98 asoc
->base
.sk
= (struct sock
*)sk
;
99 sock_hold(asoc
->base
.sk
);
101 /* Initialize the common base substructure. */
102 asoc
->base
.type
= SCTP_EP_TYPE_ASSOCIATION
;
104 /* Initialize the object handling fields. */
105 atomic_set(&asoc
->base
.refcnt
, 1);
107 asoc
->base
.malloced
= 0;
109 /* Initialize the bind addr area. */
110 sctp_bind_addr_init(&asoc
->base
.bind_addr
, ep
->base
.bind_addr
.port
);
112 asoc
->state
= SCTP_STATE_CLOSED
;
114 /* Set these values from the socket values, a conversion between
115 * millsecons to seconds/microseconds must also be done.
117 asoc
->cookie_life
.tv_sec
= sp
->assocparams
.sasoc_cookie_life
/ 1000;
118 asoc
->cookie_life
.tv_usec
= (sp
->assocparams
.sasoc_cookie_life
% 1000)
120 asoc
->frag_point
= 0;
121 asoc
->user_frag
= sp
->user_frag
;
123 /* Set the association max_retrans and RTO values from the
126 asoc
->max_retrans
= sp
->assocparams
.sasoc_asocmaxrxt
;
127 asoc
->pf_retrans
= sctp_pf_retrans
;
129 asoc
->rto_initial
= msecs_to_jiffies(sp
->rtoinfo
.srto_initial
);
130 asoc
->rto_max
= msecs_to_jiffies(sp
->rtoinfo
.srto_max
);
131 asoc
->rto_min
= msecs_to_jiffies(sp
->rtoinfo
.srto_min
);
133 asoc
->overall_error_count
= 0;
135 /* Initialize the association's heartbeat interval based on the
136 * sock configured value.
138 asoc
->hbinterval
= msecs_to_jiffies(sp
->hbinterval
);
140 /* Initialize path max retrans value. */
141 asoc
->pathmaxrxt
= sp
->pathmaxrxt
;
143 /* Initialize default path MTU. */
144 asoc
->pathmtu
= sp
->pathmtu
;
146 /* Set association default SACK delay */
147 asoc
->sackdelay
= msecs_to_jiffies(sp
->sackdelay
);
148 asoc
->sackfreq
= sp
->sackfreq
;
150 /* Set the association default flags controlling
151 * Heartbeat, SACK delay, and Path MTU Discovery.
153 asoc
->param_flags
= sp
->param_flags
;
155 /* Initialize the maximum mumber of new data packets that can be sent
158 asoc
->max_burst
= sp
->max_burst
;
160 /* initialize association timers */
161 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_NONE
] = 0;
162 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_T1_COOKIE
] = asoc
->rto_initial
;
163 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_T1_INIT
] = asoc
->rto_initial
;
164 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
] = asoc
->rto_initial
;
165 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_T3_RTX
] = 0;
166 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_T4_RTO
] = 0;
168 /* sctpimpguide Section 2.12.2
169 * If the 'T5-shutdown-guard' timer is used, it SHOULD be set to the
170 * recommended value of 5 times 'RTO.Max'.
172 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
]
175 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_HEARTBEAT
] = 0;
176 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_SACK
] = asoc
->sackdelay
;
177 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_AUTOCLOSE
] =
178 min_t(unsigned long, sp
->autoclose
, sctp_max_autoclose
) * HZ
;
180 /* Initializes the timers */
181 for (i
= SCTP_EVENT_TIMEOUT_NONE
; i
< SCTP_NUM_TIMEOUT_TYPES
; ++i
)
182 setup_timer(&asoc
->timers
[i
], sctp_timer_events
[i
],
183 (unsigned long)asoc
);
185 /* Pull default initialization values from the sock options.
186 * Note: This assumes that the values have already been
187 * validated in the sock.
189 asoc
->c
.sinit_max_instreams
= sp
->initmsg
.sinit_max_instreams
;
190 asoc
->c
.sinit_num_ostreams
= sp
->initmsg
.sinit_num_ostreams
;
191 asoc
->max_init_attempts
= sp
->initmsg
.sinit_max_attempts
;
193 asoc
->max_init_timeo
=
194 msecs_to_jiffies(sp
->initmsg
.sinit_max_init_timeo
);
196 /* Allocate storage for the ssnmap after the inbound and outbound
197 * streams have been negotiated during Init.
201 /* Set the local window size for receive.
202 * This is also the rcvbuf space per association.
203 * RFC 6 - A SCTP receiver MUST be able to receive a minimum of
204 * 1500 bytes in one SCTP packet.
206 if ((sk
->sk_rcvbuf
/2) < SCTP_DEFAULT_MINWINDOW
)
207 asoc
->rwnd
= SCTP_DEFAULT_MINWINDOW
;
209 asoc
->rwnd
= sk
->sk_rcvbuf
/2;
211 asoc
->a_rwnd
= asoc
->rwnd
;
214 asoc
->rwnd_press
= 0;
216 /* Use my own max window until I learn something better. */
217 asoc
->peer
.rwnd
= SCTP_DEFAULT_MAXWINDOW
;
219 /* Set the sndbuf size for transmit. */
220 asoc
->sndbuf_used
= 0;
222 /* Initialize the receive memory counter */
223 atomic_set(&asoc
->rmem_alloc
, 0);
225 init_waitqueue_head(&asoc
->wait
);
227 asoc
->c
.my_vtag
= sctp_generate_tag(ep
);
228 asoc
->peer
.i
.init_tag
= 0; /* INIT needs a vtag of 0. */
229 asoc
->c
.peer_vtag
= 0;
231 asoc
->c
.peer_ttag
= 0;
232 asoc
->c
.my_port
= ep
->base
.bind_addr
.port
;
234 asoc
->c
.initial_tsn
= sctp_generate_tsn(ep
);
236 asoc
->next_tsn
= asoc
->c
.initial_tsn
;
238 asoc
->ctsn_ack_point
= asoc
->next_tsn
- 1;
239 asoc
->adv_peer_ack_point
= asoc
->ctsn_ack_point
;
240 asoc
->highest_sacked
= asoc
->ctsn_ack_point
;
241 asoc
->last_cwr_tsn
= asoc
->ctsn_ack_point
;
242 asoc
->unack_data
= 0;
244 /* ADDIP Section 4.1 Asconf Chunk Procedures
246 * When an endpoint has an ASCONF signaled change to be sent to the
247 * remote endpoint it should do the following:
249 * A2) a serial number should be assigned to the chunk. The serial
250 * number SHOULD be a monotonically increasing number. The serial
251 * numbers SHOULD be initialized at the start of the
252 * association to the same value as the initial TSN.
254 asoc
->addip_serial
= asoc
->c
.initial_tsn
;
256 INIT_LIST_HEAD(&asoc
->addip_chunk_list
);
257 INIT_LIST_HEAD(&asoc
->asconf_ack_list
);
259 /* Make an empty list of remote transport addresses. */
260 INIT_LIST_HEAD(&asoc
->peer
.transport_addr_list
);
261 asoc
->peer
.transport_count
= 0;
263 /* RFC 2960 5.1 Normal Establishment of an Association
265 * After the reception of the first data chunk in an
266 * association the endpoint must immediately respond with a
267 * sack to acknowledge the data chunk. Subsequent
268 * acknowledgements should be done as described in Section
271 * [We implement this by telling a new association that it
272 * already received one packet.]
274 asoc
->peer
.sack_needed
= 1;
275 asoc
->peer
.sack_cnt
= 0;
276 asoc
->peer
.sack_generation
= 1;
278 /* Assume that the peer will tell us if he recognizes ASCONF
279 * as part of INIT exchange.
280 * The sctp_addip_noauth option is there for backward compatibilty
281 * and will revert old behavior.
283 asoc
->peer
.asconf_capable
= 0;
284 if (sctp_addip_noauth
)
285 asoc
->peer
.asconf_capable
= 1;
286 asoc
->asconf_addr_del_pending
= NULL
;
287 asoc
->src_out_of_asoc_ok
= 0;
288 asoc
->new_transport
= NULL
;
290 /* Create an input queue. */
291 sctp_inq_init(&asoc
->base
.inqueue
);
292 sctp_inq_set_th_handler(&asoc
->base
.inqueue
, sctp_assoc_bh_rcv
);
294 /* Create an output queue. */
295 sctp_outq_init(asoc
, &asoc
->outqueue
);
297 if (!sctp_ulpq_init(&asoc
->ulpq
, asoc
))
300 memset(&asoc
->peer
.tsn_map
, 0, sizeof(struct sctp_tsnmap
));
306 /* Assume that peer would support both address types unless we are
309 asoc
->peer
.ipv4_address
= 1;
310 if (asoc
->base
.sk
->sk_family
== PF_INET6
)
311 asoc
->peer
.ipv6_address
= 1;
312 INIT_LIST_HEAD(&asoc
->asocs
);
314 asoc
->autoclose
= sp
->autoclose
;
316 asoc
->default_stream
= sp
->default_stream
;
317 asoc
->default_ppid
= sp
->default_ppid
;
318 asoc
->default_flags
= sp
->default_flags
;
319 asoc
->default_context
= sp
->default_context
;
320 asoc
->default_timetolive
= sp
->default_timetolive
;
321 asoc
->default_rcv_context
= sp
->default_rcv_context
;
323 /* AUTH related initializations */
324 INIT_LIST_HEAD(&asoc
->endpoint_shared_keys
);
325 err
= sctp_auth_asoc_copy_shkeys(ep
, asoc
, gfp
);
329 asoc
->active_key_id
= ep
->active_key_id
;
330 asoc
->asoc_shared_key
= NULL
;
332 asoc
->default_hmac_id
= 0;
333 /* Save the hmacs and chunks list into this association */
334 if (ep
->auth_hmacs_list
)
335 memcpy(asoc
->c
.auth_hmacs
, ep
->auth_hmacs_list
,
336 ntohs(ep
->auth_hmacs_list
->param_hdr
.length
));
337 if (ep
->auth_chunk_list
)
338 memcpy(asoc
->c
.auth_chunks
, ep
->auth_chunk_list
,
339 ntohs(ep
->auth_chunk_list
->param_hdr
.length
));
341 /* Get the AUTH random number for this association */
342 p
= (sctp_paramhdr_t
*)asoc
->c
.auth_random
;
343 p
->type
= SCTP_PARAM_RANDOM
;
344 p
->length
= htons(sizeof(sctp_paramhdr_t
) + SCTP_AUTH_RANDOM_LENGTH
);
345 get_random_bytes(p
+1, SCTP_AUTH_RANDOM_LENGTH
);
350 sctp_endpoint_put(asoc
->ep
);
351 sock_put(asoc
->base
.sk
);
355 /* Allocate and initialize a new association */
356 struct sctp_association
*sctp_association_new(const struct sctp_endpoint
*ep
,
357 const struct sock
*sk
,
361 struct sctp_association
*asoc
;
363 asoc
= t_new(struct sctp_association
, gfp
);
367 if (!sctp_association_init(asoc
, ep
, sk
, scope
, gfp
))
370 asoc
->base
.malloced
= 1;
371 SCTP_DBG_OBJCNT_INC(assoc
);
372 SCTP_DEBUG_PRINTK("Created asoc %p\n", asoc
);
382 /* Free this association if possible. There may still be users, so
383 * the actual deallocation may be delayed.
385 void sctp_association_free(struct sctp_association
*asoc
)
387 struct sock
*sk
= asoc
->base
.sk
;
388 struct sctp_transport
*transport
;
389 struct list_head
*pos
, *temp
;
392 /* Only real associations count against the endpoint, so
393 * don't bother for if this is a temporary association.
396 list_del(&asoc
->asocs
);
398 /* Decrement the backlog value for a TCP-style listening
401 if (sctp_style(sk
, TCP
) && sctp_sstate(sk
, LISTENING
))
402 sk
->sk_ack_backlog
--;
405 /* Mark as dead, so other users can know this structure is
410 /* Dispose of any data lying around in the outqueue. */
411 sctp_outq_free(&asoc
->outqueue
);
413 /* Dispose of any pending messages for the upper layer. */
414 sctp_ulpq_free(&asoc
->ulpq
);
416 /* Dispose of any pending chunks on the inqueue. */
417 sctp_inq_free(&asoc
->base
.inqueue
);
419 sctp_tsnmap_free(&asoc
->peer
.tsn_map
);
421 /* Free ssnmap storage. */
422 sctp_ssnmap_free(asoc
->ssnmap
);
424 /* Clean up the bound address list. */
425 sctp_bind_addr_free(&asoc
->base
.bind_addr
);
427 /* Do we need to go through all of our timers and
428 * delete them? To be safe we will try to delete all, but we
429 * should be able to go through and make a guess based
432 for (i
= SCTP_EVENT_TIMEOUT_NONE
; i
< SCTP_NUM_TIMEOUT_TYPES
; ++i
) {
433 if (timer_pending(&asoc
->timers
[i
]) &&
434 del_timer(&asoc
->timers
[i
]))
435 sctp_association_put(asoc
);
438 /* Free peer's cached cookie. */
439 kfree(asoc
->peer
.cookie
);
440 kfree(asoc
->peer
.peer_random
);
441 kfree(asoc
->peer
.peer_chunks
);
442 kfree(asoc
->peer
.peer_hmacs
);
444 /* Release the transport structures. */
445 list_for_each_safe(pos
, temp
, &asoc
->peer
.transport_addr_list
) {
446 transport
= list_entry(pos
, struct sctp_transport
, transports
);
448 sctp_transport_free(transport
);
451 asoc
->peer
.transport_count
= 0;
453 sctp_asconf_queue_teardown(asoc
);
455 /* Free pending address space being deleted */
456 if (asoc
->asconf_addr_del_pending
!= NULL
)
457 kfree(asoc
->asconf_addr_del_pending
);
459 /* AUTH - Free the endpoint shared keys */
460 sctp_auth_destroy_keys(&asoc
->endpoint_shared_keys
);
462 /* AUTH - Free the association shared key */
463 sctp_auth_key_put(asoc
->asoc_shared_key
);
465 sctp_association_put(asoc
);
468 /* Cleanup and free up an association. */
469 static void sctp_association_destroy(struct sctp_association
*asoc
)
471 SCTP_ASSERT(asoc
->base
.dead
, "Assoc is not dead", return);
473 sctp_endpoint_put(asoc
->ep
);
474 sock_put(asoc
->base
.sk
);
476 if (asoc
->assoc_id
!= 0) {
477 spin_lock_bh(&sctp_assocs_id_lock
);
478 idr_remove(&sctp_assocs_id
, asoc
->assoc_id
);
479 spin_unlock_bh(&sctp_assocs_id_lock
);
482 WARN_ON(atomic_read(&asoc
->rmem_alloc
));
484 if (asoc
->base
.malloced
) {
486 SCTP_DBG_OBJCNT_DEC(assoc
);
490 /* Change the primary destination address for the peer. */
491 void sctp_assoc_set_primary(struct sctp_association
*asoc
,
492 struct sctp_transport
*transport
)
496 /* it's a changeover only if we already have a primary path
497 * that we are changing
499 if (asoc
->peer
.primary_path
!= NULL
&&
500 asoc
->peer
.primary_path
!= transport
)
503 asoc
->peer
.primary_path
= transport
;
505 /* Set a default msg_name for events. */
506 memcpy(&asoc
->peer
.primary_addr
, &transport
->ipaddr
,
507 sizeof(union sctp_addr
));
509 /* If the primary path is changing, assume that the
510 * user wants to use this new path.
512 if ((transport
->state
== SCTP_ACTIVE
) ||
513 (transport
->state
== SCTP_UNKNOWN
))
514 asoc
->peer
.active_path
= transport
;
517 * SFR-CACC algorithm:
518 * Upon the receipt of a request to change the primary
519 * destination address, on the data structure for the new
520 * primary destination, the sender MUST do the following:
522 * 1) If CHANGEOVER_ACTIVE is set, then there was a switch
523 * to this destination address earlier. The sender MUST set
524 * CYCLING_CHANGEOVER to indicate that this switch is a
525 * double switch to the same destination address.
527 * Really, only bother is we have data queued or outstanding on
530 if (!asoc
->outqueue
.outstanding_bytes
&& !asoc
->outqueue
.out_qlen
)
533 if (transport
->cacc
.changeover_active
)
534 transport
->cacc
.cycling_changeover
= changeover
;
536 /* 2) The sender MUST set CHANGEOVER_ACTIVE to indicate that
537 * a changeover has occurred.
539 transport
->cacc
.changeover_active
= changeover
;
541 /* 3) The sender MUST store the next TSN to be sent in
542 * next_tsn_at_change.
544 transport
->cacc
.next_tsn_at_change
= asoc
->next_tsn
;
547 /* Remove a transport from an association. */
548 void sctp_assoc_rm_peer(struct sctp_association
*asoc
,
549 struct sctp_transport
*peer
)
551 struct list_head
*pos
;
552 struct sctp_transport
*transport
;
554 SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_rm_peer:association %p addr: ",
558 ntohs(peer
->ipaddr
.v4
.sin_port
));
560 /* If we are to remove the current retran_path, update it
561 * to the next peer before removing this peer from the list.
563 if (asoc
->peer
.retran_path
== peer
)
564 sctp_assoc_update_retran_path(asoc
);
566 /* Remove this peer from the list. */
567 list_del(&peer
->transports
);
569 /* Get the first transport of asoc. */
570 pos
= asoc
->peer
.transport_addr_list
.next
;
571 transport
= list_entry(pos
, struct sctp_transport
, transports
);
573 /* Update any entries that match the peer to be deleted. */
574 if (asoc
->peer
.primary_path
== peer
)
575 sctp_assoc_set_primary(asoc
, transport
);
576 if (asoc
->peer
.active_path
== peer
)
577 asoc
->peer
.active_path
= transport
;
578 if (asoc
->peer
.retran_path
== peer
)
579 asoc
->peer
.retran_path
= transport
;
580 if (asoc
->peer
.last_data_from
== peer
)
581 asoc
->peer
.last_data_from
= transport
;
583 /* If we remove the transport an INIT was last sent to, set it to
584 * NULL. Combined with the update of the retran path above, this
585 * will cause the next INIT to be sent to the next available
586 * transport, maintaining the cycle.
588 if (asoc
->init_last_sent_to
== peer
)
589 asoc
->init_last_sent_to
= NULL
;
591 /* If we remove the transport an SHUTDOWN was last sent to, set it
592 * to NULL. Combined with the update of the retran path above, this
593 * will cause the next SHUTDOWN to be sent to the next available
594 * transport, maintaining the cycle.
596 if (asoc
->shutdown_last_sent_to
== peer
)
597 asoc
->shutdown_last_sent_to
= NULL
;
599 /* If we remove the transport an ASCONF was last sent to, set it to
602 if (asoc
->addip_last_asconf
&&
603 asoc
->addip_last_asconf
->transport
== peer
)
604 asoc
->addip_last_asconf
->transport
= NULL
;
606 /* If we have something on the transmitted list, we have to
607 * save it off. The best place is the active path.
609 if (!list_empty(&peer
->transmitted
)) {
610 struct sctp_transport
*active
= asoc
->peer
.active_path
;
611 struct sctp_chunk
*ch
;
613 /* Reset the transport of each chunk on this list */
614 list_for_each_entry(ch
, &peer
->transmitted
,
616 ch
->transport
= NULL
;
617 ch
->rtt_in_progress
= 0;
620 list_splice_tail_init(&peer
->transmitted
,
621 &active
->transmitted
);
623 /* Start a T3 timer here in case it wasn't running so
624 * that these migrated packets have a chance to get
627 if (!timer_pending(&active
->T3_rtx_timer
))
628 if (!mod_timer(&active
->T3_rtx_timer
,
629 jiffies
+ active
->rto
))
630 sctp_transport_hold(active
);
633 asoc
->peer
.transport_count
--;
635 sctp_transport_free(peer
);
638 /* Add a transport address to an association. */
639 struct sctp_transport
*sctp_assoc_add_peer(struct sctp_association
*asoc
,
640 const union sctp_addr
*addr
,
642 const int peer_state
)
644 struct sctp_transport
*peer
;
645 struct sctp_sock
*sp
;
648 sp
= sctp_sk(asoc
->base
.sk
);
650 /* AF_INET and AF_INET6 share common port field. */
651 port
= ntohs(addr
->v4
.sin_port
);
653 SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_add_peer:association %p addr: ",
654 " port: %d state:%d\n",
660 /* Set the port if it has not been set yet. */
661 if (0 == asoc
->peer
.port
)
662 asoc
->peer
.port
= port
;
664 /* Check to see if this is a duplicate. */
665 peer
= sctp_assoc_lookup_paddr(asoc
, addr
);
667 /* An UNKNOWN state is only set on transports added by
668 * user in sctp_connectx() call. Such transports should be
669 * considered CONFIRMED per RFC 4960, Section 5.4.
671 if (peer
->state
== SCTP_UNKNOWN
) {
672 peer
->state
= SCTP_ACTIVE
;
677 peer
= sctp_transport_new(addr
, gfp
);
681 sctp_transport_set_owner(peer
, asoc
);
683 /* Initialize the peer's heartbeat interval based on the
684 * association configured value.
686 peer
->hbinterval
= asoc
->hbinterval
;
688 /* Set the path max_retrans. */
689 peer
->pathmaxrxt
= asoc
->pathmaxrxt
;
691 /* And the partial failure retrnas threshold */
692 peer
->pf_retrans
= asoc
->pf_retrans
;
694 /* Initialize the peer's SACK delay timeout based on the
695 * association configured value.
697 peer
->sackdelay
= asoc
->sackdelay
;
698 peer
->sackfreq
= asoc
->sackfreq
;
700 /* Enable/disable heartbeat, SACK delay, and path MTU discovery
701 * based on association setting.
703 peer
->param_flags
= asoc
->param_flags
;
705 sctp_transport_route(peer
, NULL
, sp
);
707 /* Initialize the pmtu of the transport. */
708 if (peer
->param_flags
& SPP_PMTUD_DISABLE
) {
710 peer
->pathmtu
= asoc
->pathmtu
;
712 peer
->pathmtu
= SCTP_DEFAULT_MAXSEGMENT
;
715 /* If this is the first transport addr on this association,
716 * initialize the association PMTU to the peer's PMTU.
717 * If not and the current association PMTU is higher than the new
718 * peer's PMTU, reset the association PMTU to the new peer's PMTU.
721 asoc
->pathmtu
= min_t(int, peer
->pathmtu
, asoc
->pathmtu
);
723 asoc
->pathmtu
= peer
->pathmtu
;
725 SCTP_DEBUG_PRINTK("sctp_assoc_add_peer:association %p PMTU set to "
726 "%d\n", asoc
, asoc
->pathmtu
);
727 peer
->pmtu_pending
= 0;
729 asoc
->frag_point
= sctp_frag_point(asoc
, asoc
->pathmtu
);
731 /* The asoc->peer.port might not be meaningful yet, but
732 * initialize the packet structure anyway.
734 sctp_packet_init(&peer
->packet
, peer
, asoc
->base
.bind_addr
.port
,
739 * o The initial cwnd before DATA transmission or after a sufficiently
740 * long idle period MUST be set to
741 * min(4*MTU, max(2*MTU, 4380 bytes))
743 * o The initial value of ssthresh MAY be arbitrarily high
744 * (for example, implementations MAY use the size of the
745 * receiver advertised window).
747 peer
->cwnd
= min(4*asoc
->pathmtu
, max_t(__u32
, 2*asoc
->pathmtu
, 4380));
749 /* At this point, we may not have the receiver's advertised window,
750 * so initialize ssthresh to the default value and it will be set
751 * later when we process the INIT.
753 peer
->ssthresh
= SCTP_DEFAULT_MAXWINDOW
;
755 peer
->partial_bytes_acked
= 0;
756 peer
->flight_size
= 0;
757 peer
->burst_limited
= 0;
759 /* Set the transport's RTO.initial value */
760 peer
->rto
= asoc
->rto_initial
;
762 /* Set the peer's active state. */
763 peer
->state
= peer_state
;
765 /* Attach the remote transport to our asoc. */
766 list_add_tail(&peer
->transports
, &asoc
->peer
.transport_addr_list
);
767 asoc
->peer
.transport_count
++;
769 /* If we do not yet have a primary path, set one. */
770 if (!asoc
->peer
.primary_path
) {
771 sctp_assoc_set_primary(asoc
, peer
);
772 asoc
->peer
.retran_path
= peer
;
775 if (asoc
->peer
.active_path
== asoc
->peer
.retran_path
&&
776 peer
->state
!= SCTP_UNCONFIRMED
) {
777 asoc
->peer
.retran_path
= peer
;
783 /* Delete a transport address from an association. */
784 void sctp_assoc_del_peer(struct sctp_association
*asoc
,
785 const union sctp_addr
*addr
)
787 struct list_head
*pos
;
788 struct list_head
*temp
;
789 struct sctp_transport
*transport
;
791 list_for_each_safe(pos
, temp
, &asoc
->peer
.transport_addr_list
) {
792 transport
= list_entry(pos
, struct sctp_transport
, transports
);
793 if (sctp_cmp_addr_exact(addr
, &transport
->ipaddr
)) {
794 /* Do book keeping for removing the peer and free it. */
795 sctp_assoc_rm_peer(asoc
, transport
);
801 /* Lookup a transport by address. */
802 struct sctp_transport
*sctp_assoc_lookup_paddr(
803 const struct sctp_association
*asoc
,
804 const union sctp_addr
*address
)
806 struct sctp_transport
*t
;
808 /* Cycle through all transports searching for a peer address. */
810 list_for_each_entry(t
, &asoc
->peer
.transport_addr_list
,
812 if (sctp_cmp_addr_exact(address
, &t
->ipaddr
))
819 /* Remove all transports except a give one */
820 void sctp_assoc_del_nonprimary_peers(struct sctp_association
*asoc
,
821 struct sctp_transport
*primary
)
823 struct sctp_transport
*temp
;
824 struct sctp_transport
*t
;
826 list_for_each_entry_safe(t
, temp
, &asoc
->peer
.transport_addr_list
,
828 /* if the current transport is not the primary one, delete it */
830 sctp_assoc_rm_peer(asoc
, t
);
834 /* Engage in transport control operations.
835 * Mark the transport up or down and send a notification to the user.
836 * Select and update the new active and retran paths.
838 void sctp_assoc_control_transport(struct sctp_association
*asoc
,
839 struct sctp_transport
*transport
,
840 sctp_transport_cmd_t command
,
841 sctp_sn_error_t error
)
843 struct sctp_transport
*t
= NULL
;
844 struct sctp_transport
*first
;
845 struct sctp_transport
*second
;
846 struct sctp_ulpevent
*event
;
847 struct sockaddr_storage addr
;
849 bool ulp_notify
= true;
851 /* Record the transition on the transport. */
853 case SCTP_TRANSPORT_UP
:
854 /* If we are moving from UNCONFIRMED state due
855 * to heartbeat success, report the SCTP_ADDR_CONFIRMED
856 * state to the user, otherwise report SCTP_ADDR_AVAILABLE.
858 if (SCTP_UNCONFIRMED
== transport
->state
&&
859 SCTP_HEARTBEAT_SUCCESS
== error
)
860 spc_state
= SCTP_ADDR_CONFIRMED
;
862 spc_state
= SCTP_ADDR_AVAILABLE
;
863 /* Don't inform ULP about transition from PF to
864 * active state and set cwnd to 1, see SCTP
865 * Quick failover draft section 5.1, point 5
867 if (transport
->state
== SCTP_PF
) {
871 transport
->state
= SCTP_ACTIVE
;
874 case SCTP_TRANSPORT_DOWN
:
875 /* If the transport was never confirmed, do not transition it
876 * to inactive state. Also, release the cached route since
877 * there may be a better route next time.
879 if (transport
->state
!= SCTP_UNCONFIRMED
)
880 transport
->state
= SCTP_INACTIVE
;
882 dst_release(transport
->dst
);
883 transport
->dst
= NULL
;
886 spc_state
= SCTP_ADDR_UNREACHABLE
;
889 case SCTP_TRANSPORT_PF
:
890 transport
->state
= SCTP_PF
;
898 /* Generate and send a SCTP_PEER_ADDR_CHANGE notification to the
902 memset(&addr
, 0, sizeof(struct sockaddr_storage
));
903 memcpy(&addr
, &transport
->ipaddr
,
904 transport
->af_specific
->sockaddr_len
);
905 event
= sctp_ulpevent_make_peer_addr_change(asoc
, &addr
,
906 0, spc_state
, error
, GFP_ATOMIC
);
908 sctp_ulpq_tail_event(&asoc
->ulpq
, event
);
911 /* Select new active and retran paths. */
913 /* Look for the two most recently used active transports.
915 * This code produces the wrong ordering whenever jiffies
916 * rolls over, but we still get usable transports, so we don't
919 first
= NULL
; second
= NULL
;
921 list_for_each_entry(t
, &asoc
->peer
.transport_addr_list
,
924 if ((t
->state
== SCTP_INACTIVE
) ||
925 (t
->state
== SCTP_UNCONFIRMED
) ||
926 (t
->state
== SCTP_PF
))
928 if (!first
|| t
->last_time_heard
> first
->last_time_heard
) {
932 if (!second
|| t
->last_time_heard
> second
->last_time_heard
)
936 /* RFC 2960 6.4 Multi-Homed SCTP Endpoints
938 * By default, an endpoint should always transmit to the
939 * primary path, unless the SCTP user explicitly specifies the
940 * destination transport address (and possibly source
941 * transport address) to use.
943 * [If the primary is active but not most recent, bump the most
944 * recently used transport.]
946 if (((asoc
->peer
.primary_path
->state
== SCTP_ACTIVE
) ||
947 (asoc
->peer
.primary_path
->state
== SCTP_UNKNOWN
)) &&
948 first
!= asoc
->peer
.primary_path
) {
950 first
= asoc
->peer
.primary_path
;
953 /* If we failed to find a usable transport, just camp on the
954 * primary, even if it is inactive.
957 first
= asoc
->peer
.primary_path
;
958 second
= asoc
->peer
.primary_path
;
961 /* Set the active and retran transports. */
962 asoc
->peer
.active_path
= first
;
963 asoc
->peer
.retran_path
= second
;
966 /* Hold a reference to an association. */
967 void sctp_association_hold(struct sctp_association
*asoc
)
969 atomic_inc(&asoc
->base
.refcnt
);
972 /* Release a reference to an association and cleanup
973 * if there are no more references.
975 void sctp_association_put(struct sctp_association
*asoc
)
977 if (atomic_dec_and_test(&asoc
->base
.refcnt
))
978 sctp_association_destroy(asoc
);
981 /* Allocate the next TSN, Transmission Sequence Number, for the given
984 __u32
sctp_association_get_next_tsn(struct sctp_association
*asoc
)
986 /* From Section 1.6 Serial Number Arithmetic:
987 * Transmission Sequence Numbers wrap around when they reach
988 * 2**32 - 1. That is, the next TSN a DATA chunk MUST use
989 * after transmitting TSN = 2*32 - 1 is TSN = 0.
991 __u32 retval
= asoc
->next_tsn
;
998 /* Compare two addresses to see if they match. Wildcard addresses
999 * only match themselves.
1001 int sctp_cmp_addr_exact(const union sctp_addr
*ss1
,
1002 const union sctp_addr
*ss2
)
1006 af
= sctp_get_af_specific(ss1
->sa
.sa_family
);
1010 return af
->cmp_addr(ss1
, ss2
);
1013 /* Return an ecne chunk to get prepended to a packet.
1014 * Note: We are sly and return a shared, prealloced chunk. FIXME:
1015 * No we don't, but we could/should.
1017 struct sctp_chunk
*sctp_get_ecne_prepend(struct sctp_association
*asoc
)
1019 struct sctp_chunk
*chunk
;
1021 /* Send ECNE if needed.
1022 * Not being able to allocate a chunk here is not deadly.
1024 if (asoc
->need_ecne
)
1025 chunk
= sctp_make_ecne(asoc
, asoc
->last_ecne_tsn
);
1033 * Find which transport this TSN was sent on.
1035 struct sctp_transport
*sctp_assoc_lookup_tsn(struct sctp_association
*asoc
,
1038 struct sctp_transport
*active
;
1039 struct sctp_transport
*match
;
1040 struct sctp_transport
*transport
;
1041 struct sctp_chunk
*chunk
;
1042 __be32 key
= htonl(tsn
);
1047 * FIXME: In general, find a more efficient data structure for
1052 * The general strategy is to search each transport's transmitted
1053 * list. Return which transport this TSN lives on.
1055 * Let's be hopeful and check the active_path first.
1056 * Another optimization would be to know if there is only one
1057 * outbound path and not have to look for the TSN at all.
1061 active
= asoc
->peer
.active_path
;
1063 list_for_each_entry(chunk
, &active
->transmitted
,
1066 if (key
== chunk
->subh
.data_hdr
->tsn
) {
1072 /* If not found, go search all the other transports. */
1073 list_for_each_entry(transport
, &asoc
->peer
.transport_addr_list
,
1076 if (transport
== active
)
1078 list_for_each_entry(chunk
, &transport
->transmitted
,
1080 if (key
== chunk
->subh
.data_hdr
->tsn
) {
1090 /* Is this the association we are looking for? */
1091 struct sctp_transport
*sctp_assoc_is_match(struct sctp_association
*asoc
,
1092 const union sctp_addr
*laddr
,
1093 const union sctp_addr
*paddr
)
1095 struct sctp_transport
*transport
;
1097 if ((htons(asoc
->base
.bind_addr
.port
) == laddr
->v4
.sin_port
) &&
1098 (htons(asoc
->peer
.port
) == paddr
->v4
.sin_port
)) {
1099 transport
= sctp_assoc_lookup_paddr(asoc
, paddr
);
1103 if (sctp_bind_addr_match(&asoc
->base
.bind_addr
, laddr
,
1104 sctp_sk(asoc
->base
.sk
)))
1113 /* Do delayed input processing. This is scheduled by sctp_rcv(). */
1114 static void sctp_assoc_bh_rcv(struct work_struct
*work
)
1116 struct sctp_association
*asoc
=
1117 container_of(work
, struct sctp_association
,
1118 base
.inqueue
.immediate
);
1119 struct sctp_endpoint
*ep
;
1120 struct sctp_chunk
*chunk
;
1121 struct sctp_inq
*inqueue
;
1123 sctp_subtype_t subtype
;
1126 /* The association should be held so we should be safe. */
1129 inqueue
= &asoc
->base
.inqueue
;
1130 sctp_association_hold(asoc
);
1131 while (NULL
!= (chunk
= sctp_inq_pop(inqueue
))) {
1132 state
= asoc
->state
;
1133 subtype
= SCTP_ST_CHUNK(chunk
->chunk_hdr
->type
);
1135 /* SCTP-AUTH, Section 6.3:
1136 * The receiver has a list of chunk types which it expects
1137 * to be received only after an AUTH-chunk. This list has
1138 * been sent to the peer during the association setup. It
1139 * MUST silently discard these chunks if they are not placed
1140 * after an AUTH chunk in the packet.
1142 if (sctp_auth_recv_cid(subtype
.chunk
, asoc
) && !chunk
->auth
)
1145 /* Remember where the last DATA chunk came from so we
1146 * know where to send the SACK.
1148 if (sctp_chunk_is_data(chunk
))
1149 asoc
->peer
.last_data_from
= chunk
->transport
;
1151 SCTP_INC_STATS(SCTP_MIB_INCTRLCHUNKS
);
1153 if (chunk
->transport
)
1154 chunk
->transport
->last_time_heard
= jiffies
;
1156 /* Run through the state machine. */
1157 error
= sctp_do_sm(SCTP_EVENT_T_CHUNK
, subtype
,
1158 state
, ep
, asoc
, chunk
, GFP_ATOMIC
);
1160 /* Check to see if the association is freed in response to
1161 * the incoming chunk. If so, get out of the while loop.
1163 if (asoc
->base
.dead
)
1166 /* If there is an error on chunk, discard this packet. */
1168 chunk
->pdiscard
= 1;
1170 sctp_association_put(asoc
);
1173 /* This routine moves an association from its old sk to a new sk. */
1174 void sctp_assoc_migrate(struct sctp_association
*assoc
, struct sock
*newsk
)
1176 struct sctp_sock
*newsp
= sctp_sk(newsk
);
1177 struct sock
*oldsk
= assoc
->base
.sk
;
1179 /* Delete the association from the old endpoint's list of
1182 list_del_init(&assoc
->asocs
);
1184 /* Decrement the backlog value for a TCP-style socket. */
1185 if (sctp_style(oldsk
, TCP
))
1186 oldsk
->sk_ack_backlog
--;
1188 /* Release references to the old endpoint and the sock. */
1189 sctp_endpoint_put(assoc
->ep
);
1190 sock_put(assoc
->base
.sk
);
1192 /* Get a reference to the new endpoint. */
1193 assoc
->ep
= newsp
->ep
;
1194 sctp_endpoint_hold(assoc
->ep
);
1196 /* Get a reference to the new sock. */
1197 assoc
->base
.sk
= newsk
;
1198 sock_hold(assoc
->base
.sk
);
1200 /* Add the association to the new endpoint's list of associations. */
1201 sctp_endpoint_add_asoc(newsp
->ep
, assoc
);
1204 /* Update an association (possibly from unexpected COOKIE-ECHO processing). */
1205 void sctp_assoc_update(struct sctp_association
*asoc
,
1206 struct sctp_association
*new)
1208 struct sctp_transport
*trans
;
1209 struct list_head
*pos
, *temp
;
1211 /* Copy in new parameters of peer. */
1213 asoc
->peer
.rwnd
= new->peer
.rwnd
;
1214 asoc
->peer
.sack_needed
= new->peer
.sack_needed
;
1215 asoc
->peer
.i
= new->peer
.i
;
1216 sctp_tsnmap_init(&asoc
->peer
.tsn_map
, SCTP_TSN_MAP_INITIAL
,
1217 asoc
->peer
.i
.initial_tsn
, GFP_ATOMIC
);
1219 /* Remove any peer addresses not present in the new association. */
1220 list_for_each_safe(pos
, temp
, &asoc
->peer
.transport_addr_list
) {
1221 trans
= list_entry(pos
, struct sctp_transport
, transports
);
1222 if (!sctp_assoc_lookup_paddr(new, &trans
->ipaddr
)) {
1223 sctp_assoc_rm_peer(asoc
, trans
);
1227 if (asoc
->state
>= SCTP_STATE_ESTABLISHED
)
1228 sctp_transport_reset(trans
);
1231 /* If the case is A (association restart), use
1232 * initial_tsn as next_tsn. If the case is B, use
1233 * current next_tsn in case data sent to peer
1234 * has been discarded and needs retransmission.
1236 if (asoc
->state
>= SCTP_STATE_ESTABLISHED
) {
1237 asoc
->next_tsn
= new->next_tsn
;
1238 asoc
->ctsn_ack_point
= new->ctsn_ack_point
;
1239 asoc
->adv_peer_ack_point
= new->adv_peer_ack_point
;
1241 /* Reinitialize SSN for both local streams
1242 * and peer's streams.
1244 sctp_ssnmap_clear(asoc
->ssnmap
);
1246 /* Flush the ULP reassembly and ordered queue.
1247 * Any data there will now be stale and will
1250 sctp_ulpq_flush(&asoc
->ulpq
);
1252 /* reset the overall association error count so
1253 * that the restarted association doesn't get torn
1254 * down on the next retransmission timer.
1256 asoc
->overall_error_count
= 0;
1259 /* Add any peer addresses from the new association. */
1260 list_for_each_entry(trans
, &new->peer
.transport_addr_list
,
1262 if (!sctp_assoc_lookup_paddr(asoc
, &trans
->ipaddr
))
1263 sctp_assoc_add_peer(asoc
, &trans
->ipaddr
,
1264 GFP_ATOMIC
, trans
->state
);
1267 asoc
->ctsn_ack_point
= asoc
->next_tsn
- 1;
1268 asoc
->adv_peer_ack_point
= asoc
->ctsn_ack_point
;
1269 if (!asoc
->ssnmap
) {
1270 /* Move the ssnmap. */
1271 asoc
->ssnmap
= new->ssnmap
;
1275 if (!asoc
->assoc_id
) {
1276 /* get a new association id since we don't have one
1279 sctp_assoc_set_id(asoc
, GFP_ATOMIC
);
1283 /* SCTP-AUTH: Save the peer parameters from the new assocaitions
1284 * and also move the association shared keys over
1286 kfree(asoc
->peer
.peer_random
);
1287 asoc
->peer
.peer_random
= new->peer
.peer_random
;
1288 new->peer
.peer_random
= NULL
;
1290 kfree(asoc
->peer
.peer_chunks
);
1291 asoc
->peer
.peer_chunks
= new->peer
.peer_chunks
;
1292 new->peer
.peer_chunks
= NULL
;
1294 kfree(asoc
->peer
.peer_hmacs
);
1295 asoc
->peer
.peer_hmacs
= new->peer
.peer_hmacs
;
1296 new->peer
.peer_hmacs
= NULL
;
1298 sctp_auth_key_put(asoc
->asoc_shared_key
);
1299 sctp_auth_asoc_init_active_key(asoc
, GFP_ATOMIC
);
1302 /* Update the retran path for sending a retransmitted packet.
1303 * Round-robin through the active transports, else round-robin
1304 * through the inactive transports as this is the next best thing
1307 void sctp_assoc_update_retran_path(struct sctp_association
*asoc
)
1309 struct sctp_transport
*t
, *next
;
1310 struct list_head
*head
= &asoc
->peer
.transport_addr_list
;
1311 struct list_head
*pos
;
1313 if (asoc
->peer
.transport_count
== 1)
1316 /* Find the next transport in a round-robin fashion. */
1317 t
= asoc
->peer
.retran_path
;
1318 pos
= &t
->transports
;
1322 /* Skip the head. */
1323 if (pos
->next
== head
)
1328 t
= list_entry(pos
, struct sctp_transport
, transports
);
1330 /* We have exhausted the list, but didn't find any
1331 * other active transports. If so, use the next
1334 if (t
== asoc
->peer
.retran_path
) {
1339 /* Try to find an active transport. */
1341 if ((t
->state
== SCTP_ACTIVE
) ||
1342 (t
->state
== SCTP_UNKNOWN
)) {
1345 /* Keep track of the next transport in case
1346 * we don't find any active transport.
1348 if (t
->state
!= SCTP_UNCONFIRMED
&& !next
)
1354 asoc
->peer
.retran_path
= t
;
1356 t
= asoc
->peer
.retran_path
;
1358 SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_update_retran_path:association"
1363 ntohs(t
->ipaddr
.v4
.sin_port
));
1366 /* Choose the transport for sending retransmit packet. */
1367 struct sctp_transport
*sctp_assoc_choose_alter_transport(
1368 struct sctp_association
*asoc
, struct sctp_transport
*last_sent_to
)
1370 /* If this is the first time packet is sent, use the active path,
1371 * else use the retran path. If the last packet was sent over the
1372 * retran path, update the retran path and use it.
1375 return asoc
->peer
.active_path
;
1377 if (last_sent_to
== asoc
->peer
.retran_path
)
1378 sctp_assoc_update_retran_path(asoc
);
1379 return asoc
->peer
.retran_path
;
1383 /* Update the association's pmtu and frag_point by going through all the
1384 * transports. This routine is called when a transport's PMTU has changed.
1386 void sctp_assoc_sync_pmtu(struct sock
*sk
, struct sctp_association
*asoc
)
1388 struct sctp_transport
*t
;
1394 /* Get the lowest pmtu of all the transports. */
1395 list_for_each_entry(t
, &asoc
->peer
.transport_addr_list
,
1397 if (t
->pmtu_pending
&& t
->dst
) {
1398 sctp_transport_update_pmtu(sk
, t
, dst_mtu(t
->dst
));
1399 t
->pmtu_pending
= 0;
1401 if (!pmtu
|| (t
->pathmtu
< pmtu
))
1406 asoc
->pathmtu
= pmtu
;
1407 asoc
->frag_point
= sctp_frag_point(asoc
, pmtu
);
1410 SCTP_DEBUG_PRINTK("%s: asoc:%p, pmtu:%d, frag_point:%d\n",
1411 __func__
, asoc
, asoc
->pathmtu
, asoc
->frag_point
);
1414 /* Should we send a SACK to update our peer? */
1415 static inline int sctp_peer_needs_update(struct sctp_association
*asoc
)
1417 switch (asoc
->state
) {
1418 case SCTP_STATE_ESTABLISHED
:
1419 case SCTP_STATE_SHUTDOWN_PENDING
:
1420 case SCTP_STATE_SHUTDOWN_RECEIVED
:
1421 case SCTP_STATE_SHUTDOWN_SENT
:
1422 if ((asoc
->rwnd
> asoc
->a_rwnd
) &&
1423 ((asoc
->rwnd
- asoc
->a_rwnd
) >= max_t(__u32
,
1424 (asoc
->base
.sk
->sk_rcvbuf
>> sctp_rwnd_upd_shift
),
1434 /* Increase asoc's rwnd by len and send any window update SACK if needed. */
1435 void sctp_assoc_rwnd_increase(struct sctp_association
*asoc
, unsigned int len
)
1437 struct sctp_chunk
*sack
;
1438 struct timer_list
*timer
;
1440 if (asoc
->rwnd_over
) {
1441 if (asoc
->rwnd_over
>= len
) {
1442 asoc
->rwnd_over
-= len
;
1444 asoc
->rwnd
+= (len
- asoc
->rwnd_over
);
1445 asoc
->rwnd_over
= 0;
1451 /* If we had window pressure, start recovering it
1452 * once our rwnd had reached the accumulated pressure
1453 * threshold. The idea is to recover slowly, but up
1454 * to the initial advertised window.
1456 if (asoc
->rwnd_press
&& asoc
->rwnd
>= asoc
->rwnd_press
) {
1457 int change
= min(asoc
->pathmtu
, asoc
->rwnd_press
);
1458 asoc
->rwnd
+= change
;
1459 asoc
->rwnd_press
-= change
;
1462 SCTP_DEBUG_PRINTK("%s: asoc %p rwnd increased by %d to (%u, %u) "
1463 "- %u\n", __func__
, asoc
, len
, asoc
->rwnd
,
1464 asoc
->rwnd_over
, asoc
->a_rwnd
);
1466 /* Send a window update SACK if the rwnd has increased by at least the
1467 * minimum of the association's PMTU and half of the receive buffer.
1468 * The algorithm used is similar to the one described in
1469 * Section 4.2.3.3 of RFC 1122.
1471 if (sctp_peer_needs_update(asoc
)) {
1472 asoc
->a_rwnd
= asoc
->rwnd
;
1473 SCTP_DEBUG_PRINTK("%s: Sending window update SACK- asoc: %p "
1474 "rwnd: %u a_rwnd: %u\n", __func__
,
1475 asoc
, asoc
->rwnd
, asoc
->a_rwnd
);
1476 sack
= sctp_make_sack(asoc
);
1480 asoc
->peer
.sack_needed
= 0;
1482 sctp_outq_tail(&asoc
->outqueue
, sack
);
1484 /* Stop the SACK timer. */
1485 timer
= &asoc
->timers
[SCTP_EVENT_TIMEOUT_SACK
];
1486 if (timer_pending(timer
) && del_timer(timer
))
1487 sctp_association_put(asoc
);
1491 /* Decrease asoc's rwnd by len. */
1492 void sctp_assoc_rwnd_decrease(struct sctp_association
*asoc
, unsigned int len
)
1497 SCTP_ASSERT(asoc
->rwnd
, "rwnd zero", return);
1498 SCTP_ASSERT(!asoc
->rwnd_over
, "rwnd_over not zero", return);
1500 if (asoc
->ep
->rcvbuf_policy
)
1501 rx_count
= atomic_read(&asoc
->rmem_alloc
);
1503 rx_count
= atomic_read(&asoc
->base
.sk
->sk_rmem_alloc
);
1505 /* If we've reached or overflowed our receive buffer, announce
1506 * a 0 rwnd if rwnd would still be positive. Store the
1507 * the pottential pressure overflow so that the window can be restored
1508 * back to original value.
1510 if (rx_count
>= asoc
->base
.sk
->sk_rcvbuf
)
1513 if (asoc
->rwnd
>= len
) {
1516 asoc
->rwnd_press
+= asoc
->rwnd
;
1520 asoc
->rwnd_over
= len
- asoc
->rwnd
;
1523 SCTP_DEBUG_PRINTK("%s: asoc %p rwnd decreased by %d to (%u, %u, %u)\n",
1524 __func__
, asoc
, len
, asoc
->rwnd
,
1525 asoc
->rwnd_over
, asoc
->rwnd_press
);
1528 /* Build the bind address list for the association based on info from the
1529 * local endpoint and the remote peer.
1531 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association
*asoc
,
1532 sctp_scope_t scope
, gfp_t gfp
)
1536 /* Use scoping rules to determine the subset of addresses from
1539 flags
= (PF_INET6
== asoc
->base
.sk
->sk_family
) ? SCTP_ADDR6_ALLOWED
: 0;
1540 if (asoc
->peer
.ipv4_address
)
1541 flags
|= SCTP_ADDR4_PEERSUPP
;
1542 if (asoc
->peer
.ipv6_address
)
1543 flags
|= SCTP_ADDR6_PEERSUPP
;
1545 return sctp_bind_addr_copy(&asoc
->base
.bind_addr
,
1546 &asoc
->ep
->base
.bind_addr
,
1550 /* Build the association's bind address list from the cookie. */
1551 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association
*asoc
,
1552 struct sctp_cookie
*cookie
,
1555 int var_size2
= ntohs(cookie
->peer_init
->chunk_hdr
.length
);
1556 int var_size3
= cookie
->raw_addr_list_len
;
1557 __u8
*raw
= (__u8
*)cookie
->peer_init
+ var_size2
;
1559 return sctp_raw_to_bind_addrs(&asoc
->base
.bind_addr
, raw
, var_size3
,
1560 asoc
->ep
->base
.bind_addr
.port
, gfp
);
1563 /* Lookup laddr in the bind address list of an association. */
1564 int sctp_assoc_lookup_laddr(struct sctp_association
*asoc
,
1565 const union sctp_addr
*laddr
)
1569 if ((asoc
->base
.bind_addr
.port
== ntohs(laddr
->v4
.sin_port
)) &&
1570 sctp_bind_addr_match(&asoc
->base
.bind_addr
, laddr
,
1571 sctp_sk(asoc
->base
.sk
)))
1577 /* Set an association id for a given association */
1578 int sctp_assoc_set_id(struct sctp_association
*asoc
, gfp_t gfp
)
1583 /* If the id is already assigned, keep it. */
1587 if (unlikely(!idr_pre_get(&sctp_assocs_id
, gfp
)))
1590 spin_lock_bh(&sctp_assocs_id_lock
);
1591 error
= idr_get_new_above(&sctp_assocs_id
, (void *)asoc
,
1592 idr_low
, &assoc_id
);
1594 idr_low
= assoc_id
+ 1;
1595 if (idr_low
== INT_MAX
)
1598 spin_unlock_bh(&sctp_assocs_id_lock
);
1599 if (error
== -EAGAIN
)
1604 asoc
->assoc_id
= (sctp_assoc_t
) assoc_id
;
1608 /* Free the ASCONF queue */
1609 static void sctp_assoc_free_asconf_queue(struct sctp_association
*asoc
)
1611 struct sctp_chunk
*asconf
;
1612 struct sctp_chunk
*tmp
;
1614 list_for_each_entry_safe(asconf
, tmp
, &asoc
->addip_chunk_list
, list
) {
1615 list_del_init(&asconf
->list
);
1616 sctp_chunk_free(asconf
);
1620 /* Free asconf_ack cache */
1621 static void sctp_assoc_free_asconf_acks(struct sctp_association
*asoc
)
1623 struct sctp_chunk
*ack
;
1624 struct sctp_chunk
*tmp
;
1626 list_for_each_entry_safe(ack
, tmp
, &asoc
->asconf_ack_list
,
1628 list_del_init(&ack
->transmitted_list
);
1629 sctp_chunk_free(ack
);
1633 /* Clean up the ASCONF_ACK queue */
1634 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association
*asoc
)
1636 struct sctp_chunk
*ack
;
1637 struct sctp_chunk
*tmp
;
1639 /* We can remove all the entries from the queue up to
1640 * the "Peer-Sequence-Number".
1642 list_for_each_entry_safe(ack
, tmp
, &asoc
->asconf_ack_list
,
1644 if (ack
->subh
.addip_hdr
->serial
==
1645 htonl(asoc
->peer
.addip_serial
))
1648 list_del_init(&ack
->transmitted_list
);
1649 sctp_chunk_free(ack
);
1653 /* Find the ASCONF_ACK whose serial number matches ASCONF */
1654 struct sctp_chunk
*sctp_assoc_lookup_asconf_ack(
1655 const struct sctp_association
*asoc
,
1658 struct sctp_chunk
*ack
;
1660 /* Walk through the list of cached ASCONF-ACKs and find the
1661 * ack chunk whose serial number matches that of the request.
1663 list_for_each_entry(ack
, &asoc
->asconf_ack_list
, transmitted_list
) {
1664 if (ack
->subh
.addip_hdr
->serial
== serial
) {
1665 sctp_chunk_hold(ack
);
1673 void sctp_asconf_queue_teardown(struct sctp_association
*asoc
)
1675 /* Free any cached ASCONF_ACK chunk. */
1676 sctp_assoc_free_asconf_acks(asoc
);
1678 /* Free the ASCONF queue. */
1679 sctp_assoc_free_asconf_queue(asoc
);
1681 /* Free any cached ASCONF chunk. */
1682 if (asoc
->addip_last_asconf
)
1683 sctp_chunk_free(asoc
->addip_last_asconf
);