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
->rto_initial
= msecs_to_jiffies(sp
->rtoinfo
.srto_initial
);
128 asoc
->rto_max
= msecs_to_jiffies(sp
->rtoinfo
.srto_max
);
129 asoc
->rto_min
= msecs_to_jiffies(sp
->rtoinfo
.srto_min
);
131 asoc
->overall_error_count
= 0;
133 /* Initialize the association's heartbeat interval based on the
134 * sock configured value.
136 asoc
->hbinterval
= msecs_to_jiffies(sp
->hbinterval
);
138 /* Initialize path max retrans value. */
139 asoc
->pathmaxrxt
= sp
->pathmaxrxt
;
141 /* Initialize default path MTU. */
142 asoc
->pathmtu
= sp
->pathmtu
;
144 /* Set association default SACK delay */
145 asoc
->sackdelay
= msecs_to_jiffies(sp
->sackdelay
);
146 asoc
->sackfreq
= sp
->sackfreq
;
148 /* Set the association default flags controlling
149 * Heartbeat, SACK delay, and Path MTU Discovery.
151 asoc
->param_flags
= sp
->param_flags
;
153 /* Initialize the maximum mumber of new data packets that can be sent
156 asoc
->max_burst
= sp
->max_burst
;
158 /* initialize association timers */
159 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_NONE
] = 0;
160 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_T1_COOKIE
] = asoc
->rto_initial
;
161 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_T1_INIT
] = asoc
->rto_initial
;
162 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
] = asoc
->rto_initial
;
163 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_T3_RTX
] = 0;
164 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_T4_RTO
] = 0;
166 /* sctpimpguide Section 2.12.2
167 * If the 'T5-shutdown-guard' timer is used, it SHOULD be set to the
168 * recommended value of 5 times 'RTO.Max'.
170 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
]
173 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_HEARTBEAT
] = 0;
174 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_SACK
] = asoc
->sackdelay
;
175 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_AUTOCLOSE
] =
176 min_t(unsigned long, sp
->autoclose
, sctp_max_autoclose
) * HZ
;
178 /* Initializes the timers */
179 for (i
= SCTP_EVENT_TIMEOUT_NONE
; i
< SCTP_NUM_TIMEOUT_TYPES
; ++i
)
180 setup_timer(&asoc
->timers
[i
], sctp_timer_events
[i
],
181 (unsigned long)asoc
);
183 /* Pull default initialization values from the sock options.
184 * Note: This assumes that the values have already been
185 * validated in the sock.
187 asoc
->c
.sinit_max_instreams
= sp
->initmsg
.sinit_max_instreams
;
188 asoc
->c
.sinit_num_ostreams
= sp
->initmsg
.sinit_num_ostreams
;
189 asoc
->max_init_attempts
= sp
->initmsg
.sinit_max_attempts
;
191 asoc
->max_init_timeo
=
192 msecs_to_jiffies(sp
->initmsg
.sinit_max_init_timeo
);
194 /* Allocate storage for the ssnmap after the inbound and outbound
195 * streams have been negotiated during Init.
199 /* Set the local window size for receive.
200 * This is also the rcvbuf space per association.
201 * RFC 6 - A SCTP receiver MUST be able to receive a minimum of
202 * 1500 bytes in one SCTP packet.
204 if ((sk
->sk_rcvbuf
/2) < SCTP_DEFAULT_MINWINDOW
)
205 asoc
->rwnd
= SCTP_DEFAULT_MINWINDOW
;
207 asoc
->rwnd
= sk
->sk_rcvbuf
/2;
209 asoc
->a_rwnd
= asoc
->rwnd
;
212 asoc
->rwnd_press
= 0;
214 /* Use my own max window until I learn something better. */
215 asoc
->peer
.rwnd
= SCTP_DEFAULT_MAXWINDOW
;
217 /* Set the sndbuf size for transmit. */
218 asoc
->sndbuf_used
= 0;
220 /* Initialize the receive memory counter */
221 atomic_set(&asoc
->rmem_alloc
, 0);
223 init_waitqueue_head(&asoc
->wait
);
225 asoc
->c
.my_vtag
= sctp_generate_tag(ep
);
226 asoc
->peer
.i
.init_tag
= 0; /* INIT needs a vtag of 0. */
227 asoc
->c
.peer_vtag
= 0;
229 asoc
->c
.peer_ttag
= 0;
230 asoc
->c
.my_port
= ep
->base
.bind_addr
.port
;
232 asoc
->c
.initial_tsn
= sctp_generate_tsn(ep
);
234 asoc
->next_tsn
= asoc
->c
.initial_tsn
;
236 asoc
->ctsn_ack_point
= asoc
->next_tsn
- 1;
237 asoc
->adv_peer_ack_point
= asoc
->ctsn_ack_point
;
238 asoc
->highest_sacked
= asoc
->ctsn_ack_point
;
239 asoc
->last_cwr_tsn
= asoc
->ctsn_ack_point
;
240 asoc
->unack_data
= 0;
242 /* ADDIP Section 4.1 Asconf Chunk Procedures
244 * When an endpoint has an ASCONF signaled change to be sent to the
245 * remote endpoint it should do the following:
247 * A2) a serial number should be assigned to the chunk. The serial
248 * number SHOULD be a monotonically increasing number. The serial
249 * numbers SHOULD be initialized at the start of the
250 * association to the same value as the initial TSN.
252 asoc
->addip_serial
= asoc
->c
.initial_tsn
;
254 INIT_LIST_HEAD(&asoc
->addip_chunk_list
);
255 INIT_LIST_HEAD(&asoc
->asconf_ack_list
);
257 /* Make an empty list of remote transport addresses. */
258 INIT_LIST_HEAD(&asoc
->peer
.transport_addr_list
);
259 asoc
->peer
.transport_count
= 0;
261 /* RFC 2960 5.1 Normal Establishment of an Association
263 * After the reception of the first data chunk in an
264 * association the endpoint must immediately respond with a
265 * sack to acknowledge the data chunk. Subsequent
266 * acknowledgements should be done as described in Section
269 * [We implement this by telling a new association that it
270 * already received one packet.]
272 asoc
->peer
.sack_needed
= 1;
273 asoc
->peer
.sack_cnt
= 0;
275 /* Assume that the peer will tell us if he recognizes ASCONF
276 * as part of INIT exchange.
277 * The sctp_addip_noauth option is there for backward compatibilty
278 * and will revert old behavior.
280 asoc
->peer
.asconf_capable
= 0;
281 if (sctp_addip_noauth
)
282 asoc
->peer
.asconf_capable
= 1;
283 asoc
->asconf_addr_del_pending
= NULL
;
284 asoc
->src_out_of_asoc_ok
= 0;
285 asoc
->new_transport
= NULL
;
287 /* Create an input queue. */
288 sctp_inq_init(&asoc
->base
.inqueue
);
289 sctp_inq_set_th_handler(&asoc
->base
.inqueue
, sctp_assoc_bh_rcv
);
291 /* Create an output queue. */
292 sctp_outq_init(asoc
, &asoc
->outqueue
);
294 if (!sctp_ulpq_init(&asoc
->ulpq
, asoc
))
297 memset(&asoc
->peer
.tsn_map
, 0, sizeof(struct sctp_tsnmap
));
303 /* Assume that peer would support both address types unless we are
306 asoc
->peer
.ipv4_address
= 1;
307 if (asoc
->base
.sk
->sk_family
== PF_INET6
)
308 asoc
->peer
.ipv6_address
= 1;
309 INIT_LIST_HEAD(&asoc
->asocs
);
311 asoc
->autoclose
= sp
->autoclose
;
313 asoc
->default_stream
= sp
->default_stream
;
314 asoc
->default_ppid
= sp
->default_ppid
;
315 asoc
->default_flags
= sp
->default_flags
;
316 asoc
->default_context
= sp
->default_context
;
317 asoc
->default_timetolive
= sp
->default_timetolive
;
318 asoc
->default_rcv_context
= sp
->default_rcv_context
;
320 /* AUTH related initializations */
321 INIT_LIST_HEAD(&asoc
->endpoint_shared_keys
);
322 err
= sctp_auth_asoc_copy_shkeys(ep
, asoc
, gfp
);
326 asoc
->active_key_id
= ep
->active_key_id
;
327 asoc
->asoc_shared_key
= NULL
;
329 asoc
->default_hmac_id
= 0;
330 /* Save the hmacs and chunks list into this association */
331 if (ep
->auth_hmacs_list
)
332 memcpy(asoc
->c
.auth_hmacs
, ep
->auth_hmacs_list
,
333 ntohs(ep
->auth_hmacs_list
->param_hdr
.length
));
334 if (ep
->auth_chunk_list
)
335 memcpy(asoc
->c
.auth_chunks
, ep
->auth_chunk_list
,
336 ntohs(ep
->auth_chunk_list
->param_hdr
.length
));
338 /* Get the AUTH random number for this association */
339 p
= (sctp_paramhdr_t
*)asoc
->c
.auth_random
;
340 p
->type
= SCTP_PARAM_RANDOM
;
341 p
->length
= htons(sizeof(sctp_paramhdr_t
) + SCTP_AUTH_RANDOM_LENGTH
);
342 get_random_bytes(p
+1, SCTP_AUTH_RANDOM_LENGTH
);
347 sctp_endpoint_put(asoc
->ep
);
348 sock_put(asoc
->base
.sk
);
352 /* Allocate and initialize a new association */
353 struct sctp_association
*sctp_association_new(const struct sctp_endpoint
*ep
,
354 const struct sock
*sk
,
358 struct sctp_association
*asoc
;
360 asoc
= t_new(struct sctp_association
, gfp
);
364 if (!sctp_association_init(asoc
, ep
, sk
, scope
, gfp
))
367 asoc
->base
.malloced
= 1;
368 SCTP_DBG_OBJCNT_INC(assoc
);
369 SCTP_DEBUG_PRINTK("Created asoc %p\n", asoc
);
379 /* Free this association if possible. There may still be users, so
380 * the actual deallocation may be delayed.
382 void sctp_association_free(struct sctp_association
*asoc
)
384 struct sock
*sk
= asoc
->base
.sk
;
385 struct sctp_transport
*transport
;
386 struct list_head
*pos
, *temp
;
389 /* Only real associations count against the endpoint, so
390 * don't bother for if this is a temporary association.
393 list_del(&asoc
->asocs
);
395 /* Decrement the backlog value for a TCP-style listening
398 if (sctp_style(sk
, TCP
) && sctp_sstate(sk
, LISTENING
))
399 sk
->sk_ack_backlog
--;
402 /* Mark as dead, so other users can know this structure is
407 /* Dispose of any data lying around in the outqueue. */
408 sctp_outq_free(&asoc
->outqueue
);
410 /* Dispose of any pending messages for the upper layer. */
411 sctp_ulpq_free(&asoc
->ulpq
);
413 /* Dispose of any pending chunks on the inqueue. */
414 sctp_inq_free(&asoc
->base
.inqueue
);
416 sctp_tsnmap_free(&asoc
->peer
.tsn_map
);
418 /* Free ssnmap storage. */
419 sctp_ssnmap_free(asoc
->ssnmap
);
421 /* Clean up the bound address list. */
422 sctp_bind_addr_free(&asoc
->base
.bind_addr
);
424 /* Do we need to go through all of our timers and
425 * delete them? To be safe we will try to delete all, but we
426 * should be able to go through and make a guess based
429 for (i
= SCTP_EVENT_TIMEOUT_NONE
; i
< SCTP_NUM_TIMEOUT_TYPES
; ++i
) {
430 if (timer_pending(&asoc
->timers
[i
]) &&
431 del_timer(&asoc
->timers
[i
]))
432 sctp_association_put(asoc
);
435 /* Free peer's cached cookie. */
436 kfree(asoc
->peer
.cookie
);
437 kfree(asoc
->peer
.peer_random
);
438 kfree(asoc
->peer
.peer_chunks
);
439 kfree(asoc
->peer
.peer_hmacs
);
441 /* Release the transport structures. */
442 list_for_each_safe(pos
, temp
, &asoc
->peer
.transport_addr_list
) {
443 transport
= list_entry(pos
, struct sctp_transport
, transports
);
445 sctp_transport_free(transport
);
448 asoc
->peer
.transport_count
= 0;
450 sctp_asconf_queue_teardown(asoc
);
452 /* Free pending address space being deleted */
453 if (asoc
->asconf_addr_del_pending
!= NULL
)
454 kfree(asoc
->asconf_addr_del_pending
);
456 /* AUTH - Free the endpoint shared keys */
457 sctp_auth_destroy_keys(&asoc
->endpoint_shared_keys
);
459 /* AUTH - Free the association shared key */
460 sctp_auth_key_put(asoc
->asoc_shared_key
);
462 sctp_association_put(asoc
);
465 /* Cleanup and free up an association. */
466 static void sctp_association_destroy(struct sctp_association
*asoc
)
468 SCTP_ASSERT(asoc
->base
.dead
, "Assoc is not dead", return);
470 sctp_endpoint_put(asoc
->ep
);
471 sock_put(asoc
->base
.sk
);
473 if (asoc
->assoc_id
!= 0) {
474 spin_lock_bh(&sctp_assocs_id_lock
);
475 idr_remove(&sctp_assocs_id
, asoc
->assoc_id
);
476 spin_unlock_bh(&sctp_assocs_id_lock
);
479 WARN_ON(atomic_read(&asoc
->rmem_alloc
));
481 if (asoc
->base
.malloced
) {
483 SCTP_DBG_OBJCNT_DEC(assoc
);
487 /* Change the primary destination address for the peer. */
488 void sctp_assoc_set_primary(struct sctp_association
*asoc
,
489 struct sctp_transport
*transport
)
493 /* it's a changeover only if we already have a primary path
494 * that we are changing
496 if (asoc
->peer
.primary_path
!= NULL
&&
497 asoc
->peer
.primary_path
!= transport
)
500 asoc
->peer
.primary_path
= transport
;
502 /* Set a default msg_name for events. */
503 memcpy(&asoc
->peer
.primary_addr
, &transport
->ipaddr
,
504 sizeof(union sctp_addr
));
506 /* If the primary path is changing, assume that the
507 * user wants to use this new path.
509 if ((transport
->state
== SCTP_ACTIVE
) ||
510 (transport
->state
== SCTP_UNKNOWN
))
511 asoc
->peer
.active_path
= transport
;
514 * SFR-CACC algorithm:
515 * Upon the receipt of a request to change the primary
516 * destination address, on the data structure for the new
517 * primary destination, the sender MUST do the following:
519 * 1) If CHANGEOVER_ACTIVE is set, then there was a switch
520 * to this destination address earlier. The sender MUST set
521 * CYCLING_CHANGEOVER to indicate that this switch is a
522 * double switch to the same destination address.
524 * Really, only bother is we have data queued or outstanding on
527 if (!asoc
->outqueue
.outstanding_bytes
&& !asoc
->outqueue
.out_qlen
)
530 if (transport
->cacc
.changeover_active
)
531 transport
->cacc
.cycling_changeover
= changeover
;
533 /* 2) The sender MUST set CHANGEOVER_ACTIVE to indicate that
534 * a changeover has occurred.
536 transport
->cacc
.changeover_active
= changeover
;
538 /* 3) The sender MUST store the next TSN to be sent in
539 * next_tsn_at_change.
541 transport
->cacc
.next_tsn_at_change
= asoc
->next_tsn
;
544 /* Remove a transport from an association. */
545 void sctp_assoc_rm_peer(struct sctp_association
*asoc
,
546 struct sctp_transport
*peer
)
548 struct list_head
*pos
;
549 struct sctp_transport
*transport
;
551 SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_rm_peer:association %p addr: ",
555 ntohs(peer
->ipaddr
.v4
.sin_port
));
557 /* If we are to remove the current retran_path, update it
558 * to the next peer before removing this peer from the list.
560 if (asoc
->peer
.retran_path
== peer
)
561 sctp_assoc_update_retran_path(asoc
);
563 /* Remove this peer from the list. */
564 list_del(&peer
->transports
);
566 /* Get the first transport of asoc. */
567 pos
= asoc
->peer
.transport_addr_list
.next
;
568 transport
= list_entry(pos
, struct sctp_transport
, transports
);
570 /* Update any entries that match the peer to be deleted. */
571 if (asoc
->peer
.primary_path
== peer
)
572 sctp_assoc_set_primary(asoc
, transport
);
573 if (asoc
->peer
.active_path
== peer
)
574 asoc
->peer
.active_path
= transport
;
575 if (asoc
->peer
.retran_path
== peer
)
576 asoc
->peer
.retran_path
= transport
;
577 if (asoc
->peer
.last_data_from
== peer
)
578 asoc
->peer
.last_data_from
= transport
;
580 /* If we remove the transport an INIT was last sent to, set it to
581 * NULL. Combined with the update of the retran path above, this
582 * will cause the next INIT to be sent to the next available
583 * transport, maintaining the cycle.
585 if (asoc
->init_last_sent_to
== peer
)
586 asoc
->init_last_sent_to
= NULL
;
588 /* If we remove the transport an SHUTDOWN was last sent to, set it
589 * to NULL. Combined with the update of the retran path above, this
590 * will cause the next SHUTDOWN to be sent to the next available
591 * transport, maintaining the cycle.
593 if (asoc
->shutdown_last_sent_to
== peer
)
594 asoc
->shutdown_last_sent_to
= NULL
;
596 /* If we remove the transport an ASCONF was last sent to, set it to
599 if (asoc
->addip_last_asconf
&&
600 asoc
->addip_last_asconf
->transport
== peer
)
601 asoc
->addip_last_asconf
->transport
= NULL
;
603 /* If we have something on the transmitted list, we have to
604 * save it off. The best place is the active path.
606 if (!list_empty(&peer
->transmitted
)) {
607 struct sctp_transport
*active
= asoc
->peer
.active_path
;
608 struct sctp_chunk
*ch
;
610 /* Reset the transport of each chunk on this list */
611 list_for_each_entry(ch
, &peer
->transmitted
,
613 ch
->transport
= NULL
;
614 ch
->rtt_in_progress
= 0;
617 list_splice_tail_init(&peer
->transmitted
,
618 &active
->transmitted
);
620 /* Start a T3 timer here in case it wasn't running so
621 * that these migrated packets have a chance to get
624 if (!timer_pending(&active
->T3_rtx_timer
))
625 if (!mod_timer(&active
->T3_rtx_timer
,
626 jiffies
+ active
->rto
))
627 sctp_transport_hold(active
);
630 asoc
->peer
.transport_count
--;
632 sctp_transport_free(peer
);
635 /* Add a transport address to an association. */
636 struct sctp_transport
*sctp_assoc_add_peer(struct sctp_association
*asoc
,
637 const union sctp_addr
*addr
,
639 const int peer_state
)
641 struct sctp_transport
*peer
;
642 struct sctp_sock
*sp
;
645 sp
= sctp_sk(asoc
->base
.sk
);
647 /* AF_INET and AF_INET6 share common port field. */
648 port
= ntohs(addr
->v4
.sin_port
);
650 SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_add_peer:association %p addr: ",
651 " port: %d state:%d\n",
657 /* Set the port if it has not been set yet. */
658 if (0 == asoc
->peer
.port
)
659 asoc
->peer
.port
= port
;
661 /* Check to see if this is a duplicate. */
662 peer
= sctp_assoc_lookup_paddr(asoc
, addr
);
664 /* An UNKNOWN state is only set on transports added by
665 * user in sctp_connectx() call. Such transports should be
666 * considered CONFIRMED per RFC 4960, Section 5.4.
668 if (peer
->state
== SCTP_UNKNOWN
) {
669 peer
->state
= SCTP_ACTIVE
;
674 peer
= sctp_transport_new(addr
, gfp
);
678 sctp_transport_set_owner(peer
, asoc
);
680 /* Initialize the peer's heartbeat interval based on the
681 * association configured value.
683 peer
->hbinterval
= asoc
->hbinterval
;
685 /* Set the path max_retrans. */
686 peer
->pathmaxrxt
= asoc
->pathmaxrxt
;
688 /* Initialize the peer's SACK delay timeout based on the
689 * association configured value.
691 peer
->sackdelay
= asoc
->sackdelay
;
692 peer
->sackfreq
= asoc
->sackfreq
;
694 /* Enable/disable heartbeat, SACK delay, and path MTU discovery
695 * based on association setting.
697 peer
->param_flags
= asoc
->param_flags
;
699 sctp_transport_route(peer
, NULL
, sp
);
701 /* Initialize the pmtu of the transport. */
702 if (peer
->param_flags
& SPP_PMTUD_DISABLE
) {
704 peer
->pathmtu
= asoc
->pathmtu
;
706 peer
->pathmtu
= SCTP_DEFAULT_MAXSEGMENT
;
709 /* If this is the first transport addr on this association,
710 * initialize the association PMTU to the peer's PMTU.
711 * If not and the current association PMTU is higher than the new
712 * peer's PMTU, reset the association PMTU to the new peer's PMTU.
715 asoc
->pathmtu
= min_t(int, peer
->pathmtu
, asoc
->pathmtu
);
717 asoc
->pathmtu
= peer
->pathmtu
;
719 SCTP_DEBUG_PRINTK("sctp_assoc_add_peer:association %p PMTU set to "
720 "%d\n", asoc
, asoc
->pathmtu
);
721 peer
->pmtu_pending
= 0;
723 asoc
->frag_point
= sctp_frag_point(asoc
, asoc
->pathmtu
);
725 /* The asoc->peer.port might not be meaningful yet, but
726 * initialize the packet structure anyway.
728 sctp_packet_init(&peer
->packet
, peer
, asoc
->base
.bind_addr
.port
,
733 * o The initial cwnd before DATA transmission or after a sufficiently
734 * long idle period MUST be set to
735 * min(4*MTU, max(2*MTU, 4380 bytes))
737 * o The initial value of ssthresh MAY be arbitrarily high
738 * (for example, implementations MAY use the size of the
739 * receiver advertised window).
741 peer
->cwnd
= min(4*asoc
->pathmtu
, max_t(__u32
, 2*asoc
->pathmtu
, 4380));
743 /* At this point, we may not have the receiver's advertised window,
744 * so initialize ssthresh to the default value and it will be set
745 * later when we process the INIT.
747 peer
->ssthresh
= SCTP_DEFAULT_MAXWINDOW
;
749 peer
->partial_bytes_acked
= 0;
750 peer
->flight_size
= 0;
751 peer
->burst_limited
= 0;
753 /* Set the transport's RTO.initial value */
754 peer
->rto
= asoc
->rto_initial
;
756 /* Set the peer's active state. */
757 peer
->state
= peer_state
;
759 /* Attach the remote transport to our asoc. */
760 list_add_tail(&peer
->transports
, &asoc
->peer
.transport_addr_list
);
761 asoc
->peer
.transport_count
++;
763 /* If we do not yet have a primary path, set one. */
764 if (!asoc
->peer
.primary_path
) {
765 sctp_assoc_set_primary(asoc
, peer
);
766 asoc
->peer
.retran_path
= peer
;
769 if (asoc
->peer
.active_path
== asoc
->peer
.retran_path
&&
770 peer
->state
!= SCTP_UNCONFIRMED
) {
771 asoc
->peer
.retran_path
= peer
;
777 /* Delete a transport address from an association. */
778 void sctp_assoc_del_peer(struct sctp_association
*asoc
,
779 const union sctp_addr
*addr
)
781 struct list_head
*pos
;
782 struct list_head
*temp
;
783 struct sctp_transport
*transport
;
785 list_for_each_safe(pos
, temp
, &asoc
->peer
.transport_addr_list
) {
786 transport
= list_entry(pos
, struct sctp_transport
, transports
);
787 if (sctp_cmp_addr_exact(addr
, &transport
->ipaddr
)) {
788 /* Do book keeping for removing the peer and free it. */
789 sctp_assoc_rm_peer(asoc
, transport
);
795 /* Lookup a transport by address. */
796 struct sctp_transport
*sctp_assoc_lookup_paddr(
797 const struct sctp_association
*asoc
,
798 const union sctp_addr
*address
)
800 struct sctp_transport
*t
;
802 /* Cycle through all transports searching for a peer address. */
804 list_for_each_entry(t
, &asoc
->peer
.transport_addr_list
,
806 if (sctp_cmp_addr_exact(address
, &t
->ipaddr
))
813 /* Remove all transports except a give one */
814 void sctp_assoc_del_nonprimary_peers(struct sctp_association
*asoc
,
815 struct sctp_transport
*primary
)
817 struct sctp_transport
*temp
;
818 struct sctp_transport
*t
;
820 list_for_each_entry_safe(t
, temp
, &asoc
->peer
.transport_addr_list
,
822 /* if the current transport is not the primary one, delete it */
824 sctp_assoc_rm_peer(asoc
, t
);
828 /* Engage in transport control operations.
829 * Mark the transport up or down and send a notification to the user.
830 * Select and update the new active and retran paths.
832 void sctp_assoc_control_transport(struct sctp_association
*asoc
,
833 struct sctp_transport
*transport
,
834 sctp_transport_cmd_t command
,
835 sctp_sn_error_t error
)
837 struct sctp_transport
*t
= NULL
;
838 struct sctp_transport
*first
;
839 struct sctp_transport
*second
;
840 struct sctp_ulpevent
*event
;
841 struct sockaddr_storage addr
;
844 /* Record the transition on the transport. */
846 case SCTP_TRANSPORT_UP
:
847 /* If we are moving from UNCONFIRMED state due
848 * to heartbeat success, report the SCTP_ADDR_CONFIRMED
849 * state to the user, otherwise report SCTP_ADDR_AVAILABLE.
851 if (SCTP_UNCONFIRMED
== transport
->state
&&
852 SCTP_HEARTBEAT_SUCCESS
== error
)
853 spc_state
= SCTP_ADDR_CONFIRMED
;
855 spc_state
= SCTP_ADDR_AVAILABLE
;
856 transport
->state
= SCTP_ACTIVE
;
859 case SCTP_TRANSPORT_DOWN
:
860 /* If the transport was never confirmed, do not transition it
861 * to inactive state. Also, release the cached route since
862 * there may be a better route next time.
864 if (transport
->state
!= SCTP_UNCONFIRMED
)
865 transport
->state
= SCTP_INACTIVE
;
867 dst_release(transport
->dst
);
868 transport
->dst
= NULL
;
871 spc_state
= SCTP_ADDR_UNREACHABLE
;
878 /* Generate and send a SCTP_PEER_ADDR_CHANGE notification to the
881 memset(&addr
, 0, sizeof(struct sockaddr_storage
));
882 memcpy(&addr
, &transport
->ipaddr
, transport
->af_specific
->sockaddr_len
);
883 event
= sctp_ulpevent_make_peer_addr_change(asoc
, &addr
,
884 0, spc_state
, error
, GFP_ATOMIC
);
886 sctp_ulpq_tail_event(&asoc
->ulpq
, event
);
888 /* Select new active and retran paths. */
890 /* Look for the two most recently used active transports.
892 * This code produces the wrong ordering whenever jiffies
893 * rolls over, but we still get usable transports, so we don't
896 first
= NULL
; second
= NULL
;
898 list_for_each_entry(t
, &asoc
->peer
.transport_addr_list
,
901 if ((t
->state
== SCTP_INACTIVE
) ||
902 (t
->state
== SCTP_UNCONFIRMED
))
904 if (!first
|| t
->last_time_heard
> first
->last_time_heard
) {
908 if (!second
|| 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
;
929 /* If we failed to find a usable transport, just camp on the
930 * primary, even if it is inactive.
933 first
= asoc
->peer
.primary_path
;
934 second
= asoc
->peer
.primary_path
;
937 /* Set the active and retran transports. */
938 asoc
->peer
.active_path
= first
;
939 asoc
->peer
.retran_path
= second
;
942 /* Hold a reference to an association. */
943 void sctp_association_hold(struct sctp_association
*asoc
)
945 atomic_inc(&asoc
->base
.refcnt
);
948 /* Release a reference to an association and cleanup
949 * if there are no more references.
951 void sctp_association_put(struct sctp_association
*asoc
)
953 if (atomic_dec_and_test(&asoc
->base
.refcnt
))
954 sctp_association_destroy(asoc
);
957 /* Allocate the next TSN, Transmission Sequence Number, for the given
960 __u32
sctp_association_get_next_tsn(struct sctp_association
*asoc
)
962 /* From Section 1.6 Serial Number Arithmetic:
963 * Transmission Sequence Numbers wrap around when they reach
964 * 2**32 - 1. That is, the next TSN a DATA chunk MUST use
965 * after transmitting TSN = 2*32 - 1 is TSN = 0.
967 __u32 retval
= asoc
->next_tsn
;
974 /* Compare two addresses to see if they match. Wildcard addresses
975 * only match themselves.
977 int sctp_cmp_addr_exact(const union sctp_addr
*ss1
,
978 const union sctp_addr
*ss2
)
982 af
= sctp_get_af_specific(ss1
->sa
.sa_family
);
986 return af
->cmp_addr(ss1
, ss2
);
989 /* Return an ecne chunk to get prepended to a packet.
990 * Note: We are sly and return a shared, prealloced chunk. FIXME:
991 * No we don't, but we could/should.
993 struct sctp_chunk
*sctp_get_ecne_prepend(struct sctp_association
*asoc
)
995 struct sctp_chunk
*chunk
;
997 /* Send ECNE if needed.
998 * Not being able to allocate a chunk here is not deadly.
1000 if (asoc
->need_ecne
)
1001 chunk
= sctp_make_ecne(asoc
, asoc
->last_ecne_tsn
);
1009 * Find which transport this TSN was sent on.
1011 struct sctp_transport
*sctp_assoc_lookup_tsn(struct sctp_association
*asoc
,
1014 struct sctp_transport
*active
;
1015 struct sctp_transport
*match
;
1016 struct sctp_transport
*transport
;
1017 struct sctp_chunk
*chunk
;
1018 __be32 key
= htonl(tsn
);
1023 * FIXME: In general, find a more efficient data structure for
1028 * The general strategy is to search each transport's transmitted
1029 * list. Return which transport this TSN lives on.
1031 * Let's be hopeful and check the active_path first.
1032 * Another optimization would be to know if there is only one
1033 * outbound path and not have to look for the TSN at all.
1037 active
= asoc
->peer
.active_path
;
1039 list_for_each_entry(chunk
, &active
->transmitted
,
1042 if (key
== chunk
->subh
.data_hdr
->tsn
) {
1048 /* If not found, go search all the other transports. */
1049 list_for_each_entry(transport
, &asoc
->peer
.transport_addr_list
,
1052 if (transport
== active
)
1054 list_for_each_entry(chunk
, &transport
->transmitted
,
1056 if (key
== chunk
->subh
.data_hdr
->tsn
) {
1066 /* Is this the association we are looking for? */
1067 struct sctp_transport
*sctp_assoc_is_match(struct sctp_association
*asoc
,
1068 const union sctp_addr
*laddr
,
1069 const union sctp_addr
*paddr
)
1071 struct sctp_transport
*transport
;
1073 if ((htons(asoc
->base
.bind_addr
.port
) == laddr
->v4
.sin_port
) &&
1074 (htons(asoc
->peer
.port
) == paddr
->v4
.sin_port
)) {
1075 transport
= sctp_assoc_lookup_paddr(asoc
, paddr
);
1079 if (sctp_bind_addr_match(&asoc
->base
.bind_addr
, laddr
,
1080 sctp_sk(asoc
->base
.sk
)))
1089 /* Do delayed input processing. This is scheduled by sctp_rcv(). */
1090 static void sctp_assoc_bh_rcv(struct work_struct
*work
)
1092 struct sctp_association
*asoc
=
1093 container_of(work
, struct sctp_association
,
1094 base
.inqueue
.immediate
);
1095 struct sctp_endpoint
*ep
;
1096 struct sctp_chunk
*chunk
;
1097 struct sctp_inq
*inqueue
;
1099 sctp_subtype_t subtype
;
1102 /* The association should be held so we should be safe. */
1105 inqueue
= &asoc
->base
.inqueue
;
1106 sctp_association_hold(asoc
);
1107 while (NULL
!= (chunk
= sctp_inq_pop(inqueue
))) {
1108 state
= asoc
->state
;
1109 subtype
= SCTP_ST_CHUNK(chunk
->chunk_hdr
->type
);
1111 /* SCTP-AUTH, Section 6.3:
1112 * The receiver has a list of chunk types which it expects
1113 * to be received only after an AUTH-chunk. This list has
1114 * been sent to the peer during the association setup. It
1115 * MUST silently discard these chunks if they are not placed
1116 * after an AUTH chunk in the packet.
1118 if (sctp_auth_recv_cid(subtype
.chunk
, asoc
) && !chunk
->auth
)
1121 /* Remember where the last DATA chunk came from so we
1122 * know where to send the SACK.
1124 if (sctp_chunk_is_data(chunk
))
1125 asoc
->peer
.last_data_from
= chunk
->transport
;
1127 SCTP_INC_STATS(SCTP_MIB_INCTRLCHUNKS
);
1129 if (chunk
->transport
)
1130 chunk
->transport
->last_time_heard
= jiffies
;
1132 /* Run through the state machine. */
1133 error
= sctp_do_sm(SCTP_EVENT_T_CHUNK
, subtype
,
1134 state
, ep
, asoc
, chunk
, GFP_ATOMIC
);
1136 /* Check to see if the association is freed in response to
1137 * the incoming chunk. If so, get out of the while loop.
1139 if (asoc
->base
.dead
)
1142 /* If there is an error on chunk, discard this packet. */
1144 chunk
->pdiscard
= 1;
1146 sctp_association_put(asoc
);
1149 /* This routine moves an association from its old sk to a new sk. */
1150 void sctp_assoc_migrate(struct sctp_association
*assoc
, struct sock
*newsk
)
1152 struct sctp_sock
*newsp
= sctp_sk(newsk
);
1153 struct sock
*oldsk
= assoc
->base
.sk
;
1155 /* Delete the association from the old endpoint's list of
1158 list_del_init(&assoc
->asocs
);
1160 /* Decrement the backlog value for a TCP-style socket. */
1161 if (sctp_style(oldsk
, TCP
))
1162 oldsk
->sk_ack_backlog
--;
1164 /* Release references to the old endpoint and the sock. */
1165 sctp_endpoint_put(assoc
->ep
);
1166 sock_put(assoc
->base
.sk
);
1168 /* Get a reference to the new endpoint. */
1169 assoc
->ep
= newsp
->ep
;
1170 sctp_endpoint_hold(assoc
->ep
);
1172 /* Get a reference to the new sock. */
1173 assoc
->base
.sk
= newsk
;
1174 sock_hold(assoc
->base
.sk
);
1176 /* Add the association to the new endpoint's list of associations. */
1177 sctp_endpoint_add_asoc(newsp
->ep
, assoc
);
1180 /* Update an association (possibly from unexpected COOKIE-ECHO processing). */
1181 void sctp_assoc_update(struct sctp_association
*asoc
,
1182 struct sctp_association
*new)
1184 struct sctp_transport
*trans
;
1185 struct list_head
*pos
, *temp
;
1187 /* Copy in new parameters of peer. */
1189 asoc
->peer
.rwnd
= new->peer
.rwnd
;
1190 asoc
->peer
.sack_needed
= new->peer
.sack_needed
;
1191 asoc
->peer
.i
= new->peer
.i
;
1192 sctp_tsnmap_init(&asoc
->peer
.tsn_map
, SCTP_TSN_MAP_INITIAL
,
1193 asoc
->peer
.i
.initial_tsn
, GFP_ATOMIC
);
1195 /* Remove any peer addresses not present in the new association. */
1196 list_for_each_safe(pos
, temp
, &asoc
->peer
.transport_addr_list
) {
1197 trans
= list_entry(pos
, struct sctp_transport
, transports
);
1198 if (!sctp_assoc_lookup_paddr(new, &trans
->ipaddr
)) {
1199 sctp_assoc_rm_peer(asoc
, trans
);
1203 if (asoc
->state
>= SCTP_STATE_ESTABLISHED
)
1204 sctp_transport_reset(trans
);
1207 /* If the case is A (association restart), use
1208 * initial_tsn as next_tsn. If the case is B, use
1209 * current next_tsn in case data sent to peer
1210 * has been discarded and needs retransmission.
1212 if (asoc
->state
>= SCTP_STATE_ESTABLISHED
) {
1213 asoc
->next_tsn
= new->next_tsn
;
1214 asoc
->ctsn_ack_point
= new->ctsn_ack_point
;
1215 asoc
->adv_peer_ack_point
= new->adv_peer_ack_point
;
1217 /* Reinitialize SSN for both local streams
1218 * and peer's streams.
1220 sctp_ssnmap_clear(asoc
->ssnmap
);
1222 /* Flush the ULP reassembly and ordered queue.
1223 * Any data there will now be stale and will
1226 sctp_ulpq_flush(&asoc
->ulpq
);
1228 /* reset the overall association error count so
1229 * that the restarted association doesn't get torn
1230 * down on the next retransmission timer.
1232 asoc
->overall_error_count
= 0;
1235 /* Add any peer addresses from the new association. */
1236 list_for_each_entry(trans
, &new->peer
.transport_addr_list
,
1238 if (!sctp_assoc_lookup_paddr(asoc
, &trans
->ipaddr
))
1239 sctp_assoc_add_peer(asoc
, &trans
->ipaddr
,
1240 GFP_ATOMIC
, trans
->state
);
1243 asoc
->ctsn_ack_point
= asoc
->next_tsn
- 1;
1244 asoc
->adv_peer_ack_point
= asoc
->ctsn_ack_point
;
1245 if (!asoc
->ssnmap
) {
1246 /* Move the ssnmap. */
1247 asoc
->ssnmap
= new->ssnmap
;
1251 if (!asoc
->assoc_id
) {
1252 /* get a new association id since we don't have one
1255 sctp_assoc_set_id(asoc
, GFP_ATOMIC
);
1259 /* SCTP-AUTH: Save the peer parameters from the new assocaitions
1260 * and also move the association shared keys over
1262 kfree(asoc
->peer
.peer_random
);
1263 asoc
->peer
.peer_random
= new->peer
.peer_random
;
1264 new->peer
.peer_random
= NULL
;
1266 kfree(asoc
->peer
.peer_chunks
);
1267 asoc
->peer
.peer_chunks
= new->peer
.peer_chunks
;
1268 new->peer
.peer_chunks
= NULL
;
1270 kfree(asoc
->peer
.peer_hmacs
);
1271 asoc
->peer
.peer_hmacs
= new->peer
.peer_hmacs
;
1272 new->peer
.peer_hmacs
= NULL
;
1274 sctp_auth_key_put(asoc
->asoc_shared_key
);
1275 sctp_auth_asoc_init_active_key(asoc
, GFP_ATOMIC
);
1278 /* Update the retran path for sending a retransmitted packet.
1279 * Round-robin through the active transports, else round-robin
1280 * through the inactive transports as this is the next best thing
1283 void sctp_assoc_update_retran_path(struct sctp_association
*asoc
)
1285 struct sctp_transport
*t
, *next
;
1286 struct list_head
*head
= &asoc
->peer
.transport_addr_list
;
1287 struct list_head
*pos
;
1289 if (asoc
->peer
.transport_count
== 1)
1292 /* Find the next transport in a round-robin fashion. */
1293 t
= asoc
->peer
.retran_path
;
1294 pos
= &t
->transports
;
1298 /* Skip the head. */
1299 if (pos
->next
== head
)
1304 t
= list_entry(pos
, struct sctp_transport
, transports
);
1306 /* We have exhausted the list, but didn't find any
1307 * other active transports. If so, use the next
1310 if (t
== asoc
->peer
.retran_path
) {
1315 /* Try to find an active transport. */
1317 if ((t
->state
== SCTP_ACTIVE
) ||
1318 (t
->state
== SCTP_UNKNOWN
)) {
1321 /* Keep track of the next transport in case
1322 * we don't find any active transport.
1324 if (t
->state
!= SCTP_UNCONFIRMED
&& !next
)
1330 asoc
->peer
.retran_path
= t
;
1332 t
= asoc
->peer
.retran_path
;
1334 SCTP_DEBUG_PRINTK_IPADDR("sctp_assoc_update_retran_path:association"
1339 ntohs(t
->ipaddr
.v4
.sin_port
));
1342 /* Choose the transport for sending retransmit packet. */
1343 struct sctp_transport
*sctp_assoc_choose_alter_transport(
1344 struct sctp_association
*asoc
, struct sctp_transport
*last_sent_to
)
1346 /* If this is the first time packet is sent, use the active path,
1347 * else use the retran path. If the last packet was sent over the
1348 * retran path, update the retran path and use it.
1351 return asoc
->peer
.active_path
;
1353 if (last_sent_to
== asoc
->peer
.retran_path
)
1354 sctp_assoc_update_retran_path(asoc
);
1355 return asoc
->peer
.retran_path
;
1359 /* Update the association's pmtu and frag_point by going through all the
1360 * transports. This routine is called when a transport's PMTU has changed.
1362 void sctp_assoc_sync_pmtu(struct sctp_association
*asoc
)
1364 struct sctp_transport
*t
;
1370 /* Get the lowest pmtu of all the transports. */
1371 list_for_each_entry(t
, &asoc
->peer
.transport_addr_list
,
1373 if (t
->pmtu_pending
&& t
->dst
) {
1374 sctp_transport_update_pmtu(t
, dst_mtu(t
->dst
));
1375 t
->pmtu_pending
= 0;
1377 if (!pmtu
|| (t
->pathmtu
< pmtu
))
1382 asoc
->pathmtu
= pmtu
;
1383 asoc
->frag_point
= sctp_frag_point(asoc
, pmtu
);
1386 SCTP_DEBUG_PRINTK("%s: asoc:%p, pmtu:%d, frag_point:%d\n",
1387 __func__
, asoc
, asoc
->pathmtu
, asoc
->frag_point
);
1390 /* Should we send a SACK to update our peer? */
1391 static inline int sctp_peer_needs_update(struct sctp_association
*asoc
)
1393 switch (asoc
->state
) {
1394 case SCTP_STATE_ESTABLISHED
:
1395 case SCTP_STATE_SHUTDOWN_PENDING
:
1396 case SCTP_STATE_SHUTDOWN_RECEIVED
:
1397 case SCTP_STATE_SHUTDOWN_SENT
:
1398 if ((asoc
->rwnd
> asoc
->a_rwnd
) &&
1399 ((asoc
->rwnd
- asoc
->a_rwnd
) >= max_t(__u32
,
1400 (asoc
->base
.sk
->sk_rcvbuf
>> sctp_rwnd_upd_shift
),
1410 /* Increase asoc's rwnd by len and send any window update SACK if needed. */
1411 void sctp_assoc_rwnd_increase(struct sctp_association
*asoc
, unsigned len
)
1413 struct sctp_chunk
*sack
;
1414 struct timer_list
*timer
;
1416 if (asoc
->rwnd_over
) {
1417 if (asoc
->rwnd_over
>= len
) {
1418 asoc
->rwnd_over
-= len
;
1420 asoc
->rwnd
+= (len
- asoc
->rwnd_over
);
1421 asoc
->rwnd_over
= 0;
1427 /* If we had window pressure, start recovering it
1428 * once our rwnd had reached the accumulated pressure
1429 * threshold. The idea is to recover slowly, but up
1430 * to the initial advertised window.
1432 if (asoc
->rwnd_press
&& asoc
->rwnd
>= asoc
->rwnd_press
) {
1433 int change
= min(asoc
->pathmtu
, asoc
->rwnd_press
);
1434 asoc
->rwnd
+= change
;
1435 asoc
->rwnd_press
-= change
;
1438 SCTP_DEBUG_PRINTK("%s: asoc %p rwnd increased by %d to (%u, %u) "
1439 "- %u\n", __func__
, asoc
, len
, asoc
->rwnd
,
1440 asoc
->rwnd_over
, asoc
->a_rwnd
);
1442 /* Send a window update SACK if the rwnd has increased by at least the
1443 * minimum of the association's PMTU and half of the receive buffer.
1444 * The algorithm used is similar to the one described in
1445 * Section 4.2.3.3 of RFC 1122.
1447 if (sctp_peer_needs_update(asoc
)) {
1448 asoc
->a_rwnd
= asoc
->rwnd
;
1449 SCTP_DEBUG_PRINTK("%s: Sending window update SACK- asoc: %p "
1450 "rwnd: %u a_rwnd: %u\n", __func__
,
1451 asoc
, asoc
->rwnd
, asoc
->a_rwnd
);
1452 sack
= sctp_make_sack(asoc
);
1456 asoc
->peer
.sack_needed
= 0;
1458 sctp_outq_tail(&asoc
->outqueue
, sack
);
1460 /* Stop the SACK timer. */
1461 timer
= &asoc
->timers
[SCTP_EVENT_TIMEOUT_SACK
];
1462 if (timer_pending(timer
) && del_timer(timer
))
1463 sctp_association_put(asoc
);
1467 /* Decrease asoc's rwnd by len. */
1468 void sctp_assoc_rwnd_decrease(struct sctp_association
*asoc
, unsigned len
)
1473 SCTP_ASSERT(asoc
->rwnd
, "rwnd zero", return);
1474 SCTP_ASSERT(!asoc
->rwnd_over
, "rwnd_over not zero", return);
1476 if (asoc
->ep
->rcvbuf_policy
)
1477 rx_count
= atomic_read(&asoc
->rmem_alloc
);
1479 rx_count
= atomic_read(&asoc
->base
.sk
->sk_rmem_alloc
);
1481 /* If we've reached or overflowed our receive buffer, announce
1482 * a 0 rwnd if rwnd would still be positive. Store the
1483 * the pottential pressure overflow so that the window can be restored
1484 * back to original value.
1486 if (rx_count
>= asoc
->base
.sk
->sk_rcvbuf
)
1489 if (asoc
->rwnd
>= len
) {
1492 asoc
->rwnd_press
+= asoc
->rwnd
;
1496 asoc
->rwnd_over
= len
- asoc
->rwnd
;
1499 SCTP_DEBUG_PRINTK("%s: asoc %p rwnd decreased by %d to (%u, %u, %u)\n",
1500 __func__
, asoc
, len
, asoc
->rwnd
,
1501 asoc
->rwnd_over
, asoc
->rwnd_press
);
1504 /* Build the bind address list for the association based on info from the
1505 * local endpoint and the remote peer.
1507 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association
*asoc
,
1508 sctp_scope_t scope
, gfp_t gfp
)
1512 /* Use scoping rules to determine the subset of addresses from
1515 flags
= (PF_INET6
== asoc
->base
.sk
->sk_family
) ? SCTP_ADDR6_ALLOWED
: 0;
1516 if (asoc
->peer
.ipv4_address
)
1517 flags
|= SCTP_ADDR4_PEERSUPP
;
1518 if (asoc
->peer
.ipv6_address
)
1519 flags
|= SCTP_ADDR6_PEERSUPP
;
1521 return sctp_bind_addr_copy(&asoc
->base
.bind_addr
,
1522 &asoc
->ep
->base
.bind_addr
,
1526 /* Build the association's bind address list from the cookie. */
1527 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association
*asoc
,
1528 struct sctp_cookie
*cookie
,
1531 int var_size2
= ntohs(cookie
->peer_init
->chunk_hdr
.length
);
1532 int var_size3
= cookie
->raw_addr_list_len
;
1533 __u8
*raw
= (__u8
*)cookie
->peer_init
+ var_size2
;
1535 return sctp_raw_to_bind_addrs(&asoc
->base
.bind_addr
, raw
, var_size3
,
1536 asoc
->ep
->base
.bind_addr
.port
, gfp
);
1539 /* Lookup laddr in the bind address list of an association. */
1540 int sctp_assoc_lookup_laddr(struct sctp_association
*asoc
,
1541 const union sctp_addr
*laddr
)
1545 if ((asoc
->base
.bind_addr
.port
== ntohs(laddr
->v4
.sin_port
)) &&
1546 sctp_bind_addr_match(&asoc
->base
.bind_addr
, laddr
,
1547 sctp_sk(asoc
->base
.sk
)))
1553 /* Set an association id for a given association */
1554 int sctp_assoc_set_id(struct sctp_association
*asoc
, gfp_t gfp
)
1559 /* If the id is already assigned, keep it. */
1563 if (unlikely(!idr_pre_get(&sctp_assocs_id
, gfp
)))
1566 spin_lock_bh(&sctp_assocs_id_lock
);
1567 error
= idr_get_new_above(&sctp_assocs_id
, (void *)asoc
,
1568 idr_low
, &assoc_id
);
1570 idr_low
= assoc_id
+ 1;
1571 if (idr_low
== INT_MAX
)
1574 spin_unlock_bh(&sctp_assocs_id_lock
);
1575 if (error
== -EAGAIN
)
1580 asoc
->assoc_id
= (sctp_assoc_t
) assoc_id
;
1584 /* Free the ASCONF queue */
1585 static void sctp_assoc_free_asconf_queue(struct sctp_association
*asoc
)
1587 struct sctp_chunk
*asconf
;
1588 struct sctp_chunk
*tmp
;
1590 list_for_each_entry_safe(asconf
, tmp
, &asoc
->addip_chunk_list
, list
) {
1591 list_del_init(&asconf
->list
);
1592 sctp_chunk_free(asconf
);
1596 /* Free asconf_ack cache */
1597 static void sctp_assoc_free_asconf_acks(struct sctp_association
*asoc
)
1599 struct sctp_chunk
*ack
;
1600 struct sctp_chunk
*tmp
;
1602 list_for_each_entry_safe(ack
, tmp
, &asoc
->asconf_ack_list
,
1604 list_del_init(&ack
->transmitted_list
);
1605 sctp_chunk_free(ack
);
1609 /* Clean up the ASCONF_ACK queue */
1610 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association
*asoc
)
1612 struct sctp_chunk
*ack
;
1613 struct sctp_chunk
*tmp
;
1615 /* We can remove all the entries from the queue up to
1616 * the "Peer-Sequence-Number".
1618 list_for_each_entry_safe(ack
, tmp
, &asoc
->asconf_ack_list
,
1620 if (ack
->subh
.addip_hdr
->serial
==
1621 htonl(asoc
->peer
.addip_serial
))
1624 list_del_init(&ack
->transmitted_list
);
1625 sctp_chunk_free(ack
);
1629 /* Find the ASCONF_ACK whose serial number matches ASCONF */
1630 struct sctp_chunk
*sctp_assoc_lookup_asconf_ack(
1631 const struct sctp_association
*asoc
,
1634 struct sctp_chunk
*ack
;
1636 /* Walk through the list of cached ASCONF-ACKs and find the
1637 * ack chunk whose serial number matches that of the request.
1639 list_for_each_entry(ack
, &asoc
->asconf_ack_list
, transmitted_list
) {
1640 if (ack
->subh
.addip_hdr
->serial
== serial
) {
1641 sctp_chunk_hold(ack
);
1649 void sctp_asconf_queue_teardown(struct sctp_association
*asoc
)
1651 /* Free any cached ASCONF_ACK chunk. */
1652 sctp_assoc_free_asconf_acks(asoc
);
1654 /* Free the ASCONF queue. */
1655 sctp_assoc_free_asconf_queue(asoc
);
1657 /* Free any cached ASCONF chunk. */
1658 if (asoc
->addip_last_asconf
)
1659 sctp_chunk_free(asoc
->addip_last_asconf
);