1 /* SCTP kernel implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999-2000 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 * Copyright (c) 2001 Intel Corp.
6 * Copyright (c) 2001 La Monte H.P. Yarroll
8 * This file is part of the SCTP kernel implementation
10 * This module provides the abstraction for an SCTP association.
12 * This SCTP implementation is free software;
13 * you can redistribute it and/or modify it under the terms of
14 * the GNU General Public License as published by
15 * the Free Software Foundation; either version 2, or (at your option)
18 * This SCTP implementation is distributed in the hope that it
19 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
20 * ************************
21 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
22 * See the GNU General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with GNU CC; see the file COPYING. If not, see
26 * <http://www.gnu.org/licenses/>.
28 * Please send any bug reports or fixes you make to the
30 * lksctp developers <linux-sctp@vger.kernel.org>
32 * Written or modified by:
33 * La Monte H.P. Yarroll <piggy@acm.org>
34 * Karl Knutson <karl@athena.chicago.il.us>
35 * Jon Grimm <jgrimm@us.ibm.com>
36 * Xingang Guo <xingang.guo@intel.com>
37 * Hui Huang <hui.huang@nokia.com>
38 * Sridhar Samudrala <sri@us.ibm.com>
39 * Daisy Chang <daisyc@us.ibm.com>
40 * Ryan Layer <rmlayer@us.ibm.com>
41 * Kevin Gao <kevin.gao@intel.com>
44 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
46 #include <linux/types.h>
47 #include <linux/fcntl.h>
48 #include <linux/poll.h>
49 #include <linux/init.h>
51 #include <linux/slab.h>
54 #include <net/sctp/sctp.h>
55 #include <net/sctp/sm.h>
57 /* Forward declarations for internal functions. */
58 static void sctp_select_active_and_retran_path(struct sctp_association
*asoc
);
59 static void sctp_assoc_bh_rcv(struct work_struct
*work
);
60 static void sctp_assoc_free_asconf_acks(struct sctp_association
*asoc
);
61 static void sctp_assoc_free_asconf_queue(struct sctp_association
*asoc
);
63 /* 1st Level Abstractions. */
65 /* Initialize a new association from provided memory. */
66 static struct sctp_association
*sctp_association_init(struct sctp_association
*asoc
,
67 const struct sctp_endpoint
*ep
,
68 const struct sock
*sk
,
72 struct net
*net
= sock_net(sk
);
78 /* Retrieve the SCTP per socket area. */
79 sp
= sctp_sk((struct sock
*)sk
);
81 /* Discarding const is appropriate here. */
82 asoc
->ep
= (struct sctp_endpoint
*)ep
;
83 asoc
->base
.sk
= (struct sock
*)sk
;
85 sctp_endpoint_hold(asoc
->ep
);
86 sock_hold(asoc
->base
.sk
);
88 /* Initialize the common base substructure. */
89 asoc
->base
.type
= SCTP_EP_TYPE_ASSOCIATION
;
91 /* Initialize the object handling fields. */
92 atomic_set(&asoc
->base
.refcnt
, 1);
94 /* Initialize the bind addr area. */
95 sctp_bind_addr_init(&asoc
->base
.bind_addr
, ep
->base
.bind_addr
.port
);
97 asoc
->state
= SCTP_STATE_CLOSED
;
98 asoc
->cookie_life
= ms_to_ktime(sp
->assocparams
.sasoc_cookie_life
);
99 asoc
->user_frag
= sp
->user_frag
;
101 /* Set the association max_retrans and RTO values from the
104 asoc
->max_retrans
= sp
->assocparams
.sasoc_asocmaxrxt
;
105 asoc
->pf_retrans
= net
->sctp
.pf_retrans
;
107 asoc
->rto_initial
= msecs_to_jiffies(sp
->rtoinfo
.srto_initial
);
108 asoc
->rto_max
= msecs_to_jiffies(sp
->rtoinfo
.srto_max
);
109 asoc
->rto_min
= msecs_to_jiffies(sp
->rtoinfo
.srto_min
);
111 /* Initialize the association's heartbeat interval based on the
112 * sock configured value.
114 asoc
->hbinterval
= msecs_to_jiffies(sp
->hbinterval
);
116 /* Initialize path max retrans value. */
117 asoc
->pathmaxrxt
= sp
->pathmaxrxt
;
119 /* Initialize default path MTU. */
120 asoc
->pathmtu
= sp
->pathmtu
;
122 /* Set association default SACK delay */
123 asoc
->sackdelay
= msecs_to_jiffies(sp
->sackdelay
);
124 asoc
->sackfreq
= sp
->sackfreq
;
126 /* Set the association default flags controlling
127 * Heartbeat, SACK delay, and Path MTU Discovery.
129 asoc
->param_flags
= sp
->param_flags
;
131 /* Initialize the maximum number of new data packets that can be sent
134 asoc
->max_burst
= sp
->max_burst
;
136 /* initialize association timers */
137 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_T1_COOKIE
] = asoc
->rto_initial
;
138 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_T1_INIT
] = asoc
->rto_initial
;
139 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
] = asoc
->rto_initial
;
141 /* sctpimpguide Section 2.12.2
142 * If the 'T5-shutdown-guard' timer is used, it SHOULD be set to the
143 * recommended value of 5 times 'RTO.Max'.
145 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
]
148 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_SACK
] = asoc
->sackdelay
;
149 asoc
->timeouts
[SCTP_EVENT_TIMEOUT_AUTOCLOSE
] = sp
->autoclose
* HZ
;
151 /* Initializes the timers */
152 for (i
= SCTP_EVENT_TIMEOUT_NONE
; i
< SCTP_NUM_TIMEOUT_TYPES
; ++i
)
153 setup_timer(&asoc
->timers
[i
], sctp_timer_events
[i
],
154 (unsigned long)asoc
);
156 /* Pull default initialization values from the sock options.
157 * Note: This assumes that the values have already been
158 * validated in the sock.
160 asoc
->c
.sinit_max_instreams
= sp
->initmsg
.sinit_max_instreams
;
161 asoc
->c
.sinit_num_ostreams
= sp
->initmsg
.sinit_num_ostreams
;
162 asoc
->max_init_attempts
= sp
->initmsg
.sinit_max_attempts
;
164 asoc
->max_init_timeo
=
165 msecs_to_jiffies(sp
->initmsg
.sinit_max_init_timeo
);
167 /* Set the local window size for receive.
168 * This is also the rcvbuf space per association.
169 * RFC 6 - A SCTP receiver MUST be able to receive a minimum of
170 * 1500 bytes in one SCTP packet.
172 if ((sk
->sk_rcvbuf
/2) < SCTP_DEFAULT_MINWINDOW
)
173 asoc
->rwnd
= SCTP_DEFAULT_MINWINDOW
;
175 asoc
->rwnd
= sk
->sk_rcvbuf
/2;
177 asoc
->a_rwnd
= asoc
->rwnd
;
179 /* Use my own max window until I learn something better. */
180 asoc
->peer
.rwnd
= SCTP_DEFAULT_MAXWINDOW
;
182 /* Initialize the receive memory counter */
183 atomic_set(&asoc
->rmem_alloc
, 0);
185 init_waitqueue_head(&asoc
->wait
);
187 asoc
->c
.my_vtag
= sctp_generate_tag(ep
);
188 asoc
->c
.my_port
= ep
->base
.bind_addr
.port
;
190 asoc
->c
.initial_tsn
= sctp_generate_tsn(ep
);
192 asoc
->next_tsn
= asoc
->c
.initial_tsn
;
194 asoc
->ctsn_ack_point
= asoc
->next_tsn
- 1;
195 asoc
->adv_peer_ack_point
= asoc
->ctsn_ack_point
;
196 asoc
->highest_sacked
= asoc
->ctsn_ack_point
;
197 asoc
->last_cwr_tsn
= asoc
->ctsn_ack_point
;
199 /* ADDIP Section 4.1 Asconf Chunk Procedures
201 * When an endpoint has an ASCONF signaled change to be sent to the
202 * remote endpoint it should do the following:
204 * A2) a serial number should be assigned to the chunk. The serial
205 * number SHOULD be a monotonically increasing number. The serial
206 * numbers SHOULD be initialized at the start of the
207 * association to the same value as the initial TSN.
209 asoc
->addip_serial
= asoc
->c
.initial_tsn
;
210 asoc
->strreset_outseq
= asoc
->c
.initial_tsn
;
212 INIT_LIST_HEAD(&asoc
->addip_chunk_list
);
213 INIT_LIST_HEAD(&asoc
->asconf_ack_list
);
215 /* Make an empty list of remote transport addresses. */
216 INIT_LIST_HEAD(&asoc
->peer
.transport_addr_list
);
218 /* RFC 2960 5.1 Normal Establishment of an Association
220 * After the reception of the first data chunk in an
221 * association the endpoint must immediately respond with a
222 * sack to acknowledge the data chunk. Subsequent
223 * acknowledgements should be done as described in Section
226 * [We implement this by telling a new association that it
227 * already received one packet.]
229 asoc
->peer
.sack_needed
= 1;
230 asoc
->peer
.sack_generation
= 1;
232 /* Assume that the peer will tell us if he recognizes ASCONF
233 * as part of INIT exchange.
234 * The sctp_addip_noauth option is there for backward compatibility
235 * and will revert old behavior.
237 if (net
->sctp
.addip_noauth
)
238 asoc
->peer
.asconf_capable
= 1;
240 /* Create an input queue. */
241 sctp_inq_init(&asoc
->base
.inqueue
);
242 sctp_inq_set_th_handler(&asoc
->base
.inqueue
, sctp_assoc_bh_rcv
);
244 /* Create an output queue. */
245 sctp_outq_init(asoc
, &asoc
->outqueue
);
247 if (!sctp_ulpq_init(&asoc
->ulpq
, asoc
))
250 /* Assume that peer would support both address types unless we are
253 asoc
->peer
.ipv4_address
= 1;
254 if (asoc
->base
.sk
->sk_family
== PF_INET6
)
255 asoc
->peer
.ipv6_address
= 1;
256 INIT_LIST_HEAD(&asoc
->asocs
);
258 asoc
->default_stream
= sp
->default_stream
;
259 asoc
->default_ppid
= sp
->default_ppid
;
260 asoc
->default_flags
= sp
->default_flags
;
261 asoc
->default_context
= sp
->default_context
;
262 asoc
->default_timetolive
= sp
->default_timetolive
;
263 asoc
->default_rcv_context
= sp
->default_rcv_context
;
265 /* AUTH related initializations */
266 INIT_LIST_HEAD(&asoc
->endpoint_shared_keys
);
267 err
= sctp_auth_asoc_copy_shkeys(ep
, asoc
, gfp
);
271 asoc
->active_key_id
= ep
->active_key_id
;
272 asoc
->prsctp_enable
= ep
->prsctp_enable
;
273 asoc
->reconf_enable
= ep
->reconf_enable
;
274 asoc
->strreset_enable
= ep
->strreset_enable
;
276 /* Save the hmacs and chunks list into this association */
277 if (ep
->auth_hmacs_list
)
278 memcpy(asoc
->c
.auth_hmacs
, ep
->auth_hmacs_list
,
279 ntohs(ep
->auth_hmacs_list
->param_hdr
.length
));
280 if (ep
->auth_chunk_list
)
281 memcpy(asoc
->c
.auth_chunks
, ep
->auth_chunk_list
,
282 ntohs(ep
->auth_chunk_list
->param_hdr
.length
));
284 /* Get the AUTH random number for this association */
285 p
= (sctp_paramhdr_t
*)asoc
->c
.auth_random
;
286 p
->type
= SCTP_PARAM_RANDOM
;
287 p
->length
= htons(sizeof(sctp_paramhdr_t
) + SCTP_AUTH_RANDOM_LENGTH
);
288 get_random_bytes(p
+1, SCTP_AUTH_RANDOM_LENGTH
);
293 sock_put(asoc
->base
.sk
);
294 sctp_endpoint_put(asoc
->ep
);
298 /* Allocate and initialize a new association */
299 struct sctp_association
*sctp_association_new(const struct sctp_endpoint
*ep
,
300 const struct sock
*sk
,
304 struct sctp_association
*asoc
;
306 asoc
= kzalloc(sizeof(*asoc
), gfp
);
310 if (!sctp_association_init(asoc
, ep
, sk
, scope
, gfp
))
313 SCTP_DBG_OBJCNT_INC(assoc
);
315 pr_debug("Created asoc %p\n", asoc
);
325 /* Free this association if possible. There may still be users, so
326 * the actual deallocation may be delayed.
328 void sctp_association_free(struct sctp_association
*asoc
)
330 struct sock
*sk
= asoc
->base
.sk
;
331 struct sctp_transport
*transport
;
332 struct list_head
*pos
, *temp
;
335 /* Only real associations count against the endpoint, so
336 * don't bother for if this is a temporary association.
338 if (!list_empty(&asoc
->asocs
)) {
339 list_del(&asoc
->asocs
);
341 /* Decrement the backlog value for a TCP-style listening
344 if (sctp_style(sk
, TCP
) && sctp_sstate(sk
, LISTENING
))
345 sk
->sk_ack_backlog
--;
348 /* Mark as dead, so other users can know this structure is
351 asoc
->base
.dead
= true;
353 /* Dispose of any data lying around in the outqueue. */
354 sctp_outq_free(&asoc
->outqueue
);
356 /* Dispose of any pending messages for the upper layer. */
357 sctp_ulpq_free(&asoc
->ulpq
);
359 /* Dispose of any pending chunks on the inqueue. */
360 sctp_inq_free(&asoc
->base
.inqueue
);
362 sctp_tsnmap_free(&asoc
->peer
.tsn_map
);
364 /* Free stream information. */
365 sctp_stream_free(asoc
->stream
);
367 if (asoc
->strreset_chunk
)
368 sctp_chunk_free(asoc
->strreset_chunk
);
370 /* Clean up the bound address list. */
371 sctp_bind_addr_free(&asoc
->base
.bind_addr
);
373 /* Do we need to go through all of our timers and
374 * delete them? To be safe we will try to delete all, but we
375 * should be able to go through and make a guess based
378 for (i
= SCTP_EVENT_TIMEOUT_NONE
; i
< SCTP_NUM_TIMEOUT_TYPES
; ++i
) {
379 if (del_timer(&asoc
->timers
[i
]))
380 sctp_association_put(asoc
);
383 /* Free peer's cached cookie. */
384 kfree(asoc
->peer
.cookie
);
385 kfree(asoc
->peer
.peer_random
);
386 kfree(asoc
->peer
.peer_chunks
);
387 kfree(asoc
->peer
.peer_hmacs
);
389 /* Release the transport structures. */
390 list_for_each_safe(pos
, temp
, &asoc
->peer
.transport_addr_list
) {
391 transport
= list_entry(pos
, struct sctp_transport
, transports
);
393 sctp_unhash_transport(transport
);
394 sctp_transport_free(transport
);
397 asoc
->peer
.transport_count
= 0;
399 sctp_asconf_queue_teardown(asoc
);
401 /* Free pending address space being deleted */
402 kfree(asoc
->asconf_addr_del_pending
);
404 /* AUTH - Free the endpoint shared keys */
405 sctp_auth_destroy_keys(&asoc
->endpoint_shared_keys
);
407 /* AUTH - Free the association shared key */
408 sctp_auth_key_put(asoc
->asoc_shared_key
);
410 sctp_association_put(asoc
);
413 /* Cleanup and free up an association. */
414 static void sctp_association_destroy(struct sctp_association
*asoc
)
416 if (unlikely(!asoc
->base
.dead
)) {
417 WARN(1, "Attempt to destroy undead association %p!\n", asoc
);
421 sctp_endpoint_put(asoc
->ep
);
422 sock_put(asoc
->base
.sk
);
424 if (asoc
->assoc_id
!= 0) {
425 spin_lock_bh(&sctp_assocs_id_lock
);
426 idr_remove(&sctp_assocs_id
, asoc
->assoc_id
);
427 spin_unlock_bh(&sctp_assocs_id_lock
);
430 WARN_ON(atomic_read(&asoc
->rmem_alloc
));
433 SCTP_DBG_OBJCNT_DEC(assoc
);
436 /* Change the primary destination address for the peer. */
437 void sctp_assoc_set_primary(struct sctp_association
*asoc
,
438 struct sctp_transport
*transport
)
442 /* it's a changeover only if we already have a primary path
443 * that we are changing
445 if (asoc
->peer
.primary_path
!= NULL
&&
446 asoc
->peer
.primary_path
!= transport
)
449 asoc
->peer
.primary_path
= transport
;
451 /* Set a default msg_name for events. */
452 memcpy(&asoc
->peer
.primary_addr
, &transport
->ipaddr
,
453 sizeof(union sctp_addr
));
455 /* If the primary path is changing, assume that the
456 * user wants to use this new path.
458 if ((transport
->state
== SCTP_ACTIVE
) ||
459 (transport
->state
== SCTP_UNKNOWN
))
460 asoc
->peer
.active_path
= transport
;
463 * SFR-CACC algorithm:
464 * Upon the receipt of a request to change the primary
465 * destination address, on the data structure for the new
466 * primary destination, the sender MUST do the following:
468 * 1) If CHANGEOVER_ACTIVE is set, then there was a switch
469 * to this destination address earlier. The sender MUST set
470 * CYCLING_CHANGEOVER to indicate that this switch is a
471 * double switch to the same destination address.
473 * Really, only bother is we have data queued or outstanding on
476 if (!asoc
->outqueue
.outstanding_bytes
&& !asoc
->outqueue
.out_qlen
)
479 if (transport
->cacc
.changeover_active
)
480 transport
->cacc
.cycling_changeover
= changeover
;
482 /* 2) The sender MUST set CHANGEOVER_ACTIVE to indicate that
483 * a changeover has occurred.
485 transport
->cacc
.changeover_active
= changeover
;
487 /* 3) The sender MUST store the next TSN to be sent in
488 * next_tsn_at_change.
490 transport
->cacc
.next_tsn_at_change
= asoc
->next_tsn
;
493 /* Remove a transport from an association. */
494 void sctp_assoc_rm_peer(struct sctp_association
*asoc
,
495 struct sctp_transport
*peer
)
497 struct list_head
*pos
;
498 struct sctp_transport
*transport
;
500 pr_debug("%s: association:%p addr:%pISpc\n",
501 __func__
, asoc
, &peer
->ipaddr
.sa
);
503 /* If we are to remove the current retran_path, update it
504 * to the next peer before removing this peer from the list.
506 if (asoc
->peer
.retran_path
== peer
)
507 sctp_assoc_update_retran_path(asoc
);
509 /* Remove this peer from the list. */
510 list_del_rcu(&peer
->transports
);
511 /* Remove this peer from the transport hashtable */
512 sctp_unhash_transport(peer
);
514 /* Get the first transport of asoc. */
515 pos
= asoc
->peer
.transport_addr_list
.next
;
516 transport
= list_entry(pos
, struct sctp_transport
, transports
);
518 /* Update any entries that match the peer to be deleted. */
519 if (asoc
->peer
.primary_path
== peer
)
520 sctp_assoc_set_primary(asoc
, transport
);
521 if (asoc
->peer
.active_path
== peer
)
522 asoc
->peer
.active_path
= transport
;
523 if (asoc
->peer
.retran_path
== peer
)
524 asoc
->peer
.retran_path
= transport
;
525 if (asoc
->peer
.last_data_from
== peer
)
526 asoc
->peer
.last_data_from
= transport
;
528 if (asoc
->strreset_chunk
&&
529 asoc
->strreset_chunk
->transport
== peer
) {
530 asoc
->strreset_chunk
->transport
= transport
;
531 sctp_transport_reset_reconf_timer(transport
);
534 /* If we remove the transport an INIT was last sent to, set it to
535 * NULL. Combined with the update of the retran path above, this
536 * will cause the next INIT to be sent to the next available
537 * transport, maintaining the cycle.
539 if (asoc
->init_last_sent_to
== peer
)
540 asoc
->init_last_sent_to
= NULL
;
542 /* If we remove the transport an SHUTDOWN was last sent to, set it
543 * to NULL. Combined with the update of the retran path above, this
544 * will cause the next SHUTDOWN to be sent to the next available
545 * transport, maintaining the cycle.
547 if (asoc
->shutdown_last_sent_to
== peer
)
548 asoc
->shutdown_last_sent_to
= NULL
;
550 /* If we remove the transport an ASCONF was last sent to, set it to
553 if (asoc
->addip_last_asconf
&&
554 asoc
->addip_last_asconf
->transport
== peer
)
555 asoc
->addip_last_asconf
->transport
= NULL
;
557 /* If we have something on the transmitted list, we have to
558 * save it off. The best place is the active path.
560 if (!list_empty(&peer
->transmitted
)) {
561 struct sctp_transport
*active
= asoc
->peer
.active_path
;
562 struct sctp_chunk
*ch
;
564 /* Reset the transport of each chunk on this list */
565 list_for_each_entry(ch
, &peer
->transmitted
,
567 ch
->transport
= NULL
;
568 ch
->rtt_in_progress
= 0;
571 list_splice_tail_init(&peer
->transmitted
,
572 &active
->transmitted
);
574 /* Start a T3 timer here in case it wasn't running so
575 * that these migrated packets have a chance to get
578 if (!timer_pending(&active
->T3_rtx_timer
))
579 if (!mod_timer(&active
->T3_rtx_timer
,
580 jiffies
+ active
->rto
))
581 sctp_transport_hold(active
);
584 asoc
->peer
.transport_count
--;
586 sctp_transport_free(peer
);
589 /* Add a transport address to an association. */
590 struct sctp_transport
*sctp_assoc_add_peer(struct sctp_association
*asoc
,
591 const union sctp_addr
*addr
,
593 const int peer_state
)
595 struct net
*net
= sock_net(asoc
->base
.sk
);
596 struct sctp_transport
*peer
;
597 struct sctp_sock
*sp
;
600 sp
= sctp_sk(asoc
->base
.sk
);
602 /* AF_INET and AF_INET6 share common port field. */
603 port
= ntohs(addr
->v4
.sin_port
);
605 pr_debug("%s: association:%p addr:%pISpc state:%d\n", __func__
,
606 asoc
, &addr
->sa
, peer_state
);
608 /* Set the port if it has not been set yet. */
609 if (0 == asoc
->peer
.port
)
610 asoc
->peer
.port
= port
;
612 /* Check to see if this is a duplicate. */
613 peer
= sctp_assoc_lookup_paddr(asoc
, addr
);
615 /* An UNKNOWN state is only set on transports added by
616 * user in sctp_connectx() call. Such transports should be
617 * considered CONFIRMED per RFC 4960, Section 5.4.
619 if (peer
->state
== SCTP_UNKNOWN
) {
620 peer
->state
= SCTP_ACTIVE
;
625 peer
= sctp_transport_new(net
, addr
, gfp
);
629 sctp_transport_set_owner(peer
, asoc
);
631 /* Initialize the peer's heartbeat interval based on the
632 * association configured value.
634 peer
->hbinterval
= asoc
->hbinterval
;
636 /* Set the path max_retrans. */
637 peer
->pathmaxrxt
= asoc
->pathmaxrxt
;
639 /* And the partial failure retrans threshold */
640 peer
->pf_retrans
= asoc
->pf_retrans
;
642 /* Initialize the peer's SACK delay timeout based on the
643 * association configured value.
645 peer
->sackdelay
= asoc
->sackdelay
;
646 peer
->sackfreq
= asoc
->sackfreq
;
648 /* Enable/disable heartbeat, SACK delay, and path MTU discovery
649 * based on association setting.
651 peer
->param_flags
= asoc
->param_flags
;
653 sctp_transport_route(peer
, NULL
, sp
);
655 /* Initialize the pmtu of the transport. */
656 if (peer
->param_flags
& SPP_PMTUD_DISABLE
) {
658 peer
->pathmtu
= asoc
->pathmtu
;
660 peer
->pathmtu
= SCTP_DEFAULT_MAXSEGMENT
;
663 /* If this is the first transport addr on this association,
664 * initialize the association PMTU to the peer's PMTU.
665 * If not and the current association PMTU is higher than the new
666 * peer's PMTU, reset the association PMTU to the new peer's PMTU.
669 asoc
->pathmtu
= min_t(int, peer
->pathmtu
, asoc
->pathmtu
);
671 asoc
->pathmtu
= peer
->pathmtu
;
673 pr_debug("%s: association:%p PMTU set to %d\n", __func__
, asoc
,
676 peer
->pmtu_pending
= 0;
678 asoc
->frag_point
= sctp_frag_point(asoc
, asoc
->pathmtu
);
680 /* The asoc->peer.port might not be meaningful yet, but
681 * initialize the packet structure anyway.
683 sctp_packet_init(&peer
->packet
, peer
, asoc
->base
.bind_addr
.port
,
688 * o The initial cwnd before DATA transmission or after a sufficiently
689 * long idle period MUST be set to
690 * min(4*MTU, max(2*MTU, 4380 bytes))
692 * o The initial value of ssthresh MAY be arbitrarily high
693 * (for example, implementations MAY use the size of the
694 * receiver advertised window).
696 peer
->cwnd
= min(4*asoc
->pathmtu
, max_t(__u32
, 2*asoc
->pathmtu
, 4380));
698 /* At this point, we may not have the receiver's advertised window,
699 * so initialize ssthresh to the default value and it will be set
700 * later when we process the INIT.
702 peer
->ssthresh
= SCTP_DEFAULT_MAXWINDOW
;
704 peer
->partial_bytes_acked
= 0;
705 peer
->flight_size
= 0;
706 peer
->burst_limited
= 0;
708 /* Set the transport's RTO.initial value */
709 peer
->rto
= asoc
->rto_initial
;
710 sctp_max_rto(asoc
, peer
);
712 /* Set the peer's active state. */
713 peer
->state
= peer_state
;
715 /* Add this peer into the transport hashtable */
716 if (sctp_hash_transport(peer
)) {
717 sctp_transport_free(peer
);
721 /* Attach the remote transport to our asoc. */
722 list_add_tail_rcu(&peer
->transports
, &asoc
->peer
.transport_addr_list
);
723 asoc
->peer
.transport_count
++;
725 /* If we do not yet have a primary path, set one. */
726 if (!asoc
->peer
.primary_path
) {
727 sctp_assoc_set_primary(asoc
, peer
);
728 asoc
->peer
.retran_path
= peer
;
731 if (asoc
->peer
.active_path
== asoc
->peer
.retran_path
&&
732 peer
->state
!= SCTP_UNCONFIRMED
) {
733 asoc
->peer
.retran_path
= peer
;
739 /* Delete a transport address from an association. */
740 void sctp_assoc_del_peer(struct sctp_association
*asoc
,
741 const union sctp_addr
*addr
)
743 struct list_head
*pos
;
744 struct list_head
*temp
;
745 struct sctp_transport
*transport
;
747 list_for_each_safe(pos
, temp
, &asoc
->peer
.transport_addr_list
) {
748 transport
= list_entry(pos
, struct sctp_transport
, transports
);
749 if (sctp_cmp_addr_exact(addr
, &transport
->ipaddr
)) {
750 /* Do book keeping for removing the peer and free it. */
751 sctp_assoc_rm_peer(asoc
, transport
);
757 /* Lookup a transport by address. */
758 struct sctp_transport
*sctp_assoc_lookup_paddr(
759 const struct sctp_association
*asoc
,
760 const union sctp_addr
*address
)
762 struct sctp_transport
*t
;
764 /* Cycle through all transports searching for a peer address. */
766 list_for_each_entry(t
, &asoc
->peer
.transport_addr_list
,
768 if (sctp_cmp_addr_exact(address
, &t
->ipaddr
))
775 /* Remove all transports except a give one */
776 void sctp_assoc_del_nonprimary_peers(struct sctp_association
*asoc
,
777 struct sctp_transport
*primary
)
779 struct sctp_transport
*temp
;
780 struct sctp_transport
*t
;
782 list_for_each_entry_safe(t
, temp
, &asoc
->peer
.transport_addr_list
,
784 /* if the current transport is not the primary one, delete it */
786 sctp_assoc_rm_peer(asoc
, t
);
790 /* Engage in transport control operations.
791 * Mark the transport up or down and send a notification to the user.
792 * Select and update the new active and retran paths.
794 void sctp_assoc_control_transport(struct sctp_association
*asoc
,
795 struct sctp_transport
*transport
,
796 sctp_transport_cmd_t command
,
797 sctp_sn_error_t error
)
799 struct sctp_ulpevent
*event
;
800 struct sockaddr_storage addr
;
802 bool ulp_notify
= true;
804 /* Record the transition on the transport. */
806 case SCTP_TRANSPORT_UP
:
807 /* If we are moving from UNCONFIRMED state due
808 * to heartbeat success, report the SCTP_ADDR_CONFIRMED
809 * state to the user, otherwise report SCTP_ADDR_AVAILABLE.
811 if (SCTP_UNCONFIRMED
== transport
->state
&&
812 SCTP_HEARTBEAT_SUCCESS
== error
)
813 spc_state
= SCTP_ADDR_CONFIRMED
;
815 spc_state
= SCTP_ADDR_AVAILABLE
;
816 /* Don't inform ULP about transition from PF to
817 * active state and set cwnd to 1 MTU, see SCTP
818 * Quick failover draft section 5.1, point 5
820 if (transport
->state
== SCTP_PF
) {
822 transport
->cwnd
= asoc
->pathmtu
;
824 transport
->state
= SCTP_ACTIVE
;
827 case SCTP_TRANSPORT_DOWN
:
828 /* If the transport was never confirmed, do not transition it
829 * to inactive state. Also, release the cached route since
830 * there may be a better route next time.
832 if (transport
->state
!= SCTP_UNCONFIRMED
)
833 transport
->state
= SCTP_INACTIVE
;
835 dst_release(transport
->dst
);
836 transport
->dst
= NULL
;
840 spc_state
= SCTP_ADDR_UNREACHABLE
;
843 case SCTP_TRANSPORT_PF
:
844 transport
->state
= SCTP_PF
;
852 /* Generate and send a SCTP_PEER_ADDR_CHANGE notification
856 memset(&addr
, 0, sizeof(struct sockaddr_storage
));
857 memcpy(&addr
, &transport
->ipaddr
,
858 transport
->af_specific
->sockaddr_len
);
860 event
= sctp_ulpevent_make_peer_addr_change(asoc
, &addr
,
861 0, spc_state
, error
, GFP_ATOMIC
);
863 sctp_ulpq_tail_event(&asoc
->ulpq
, event
);
866 /* Select new active and retran paths. */
867 sctp_select_active_and_retran_path(asoc
);
870 /* Hold a reference to an association. */
871 void sctp_association_hold(struct sctp_association
*asoc
)
873 atomic_inc(&asoc
->base
.refcnt
);
876 /* Release a reference to an association and cleanup
877 * if there are no more references.
879 void sctp_association_put(struct sctp_association
*asoc
)
881 if (atomic_dec_and_test(&asoc
->base
.refcnt
))
882 sctp_association_destroy(asoc
);
885 /* Allocate the next TSN, Transmission Sequence Number, for the given
888 __u32
sctp_association_get_next_tsn(struct sctp_association
*asoc
)
890 /* From Section 1.6 Serial Number Arithmetic:
891 * Transmission Sequence Numbers wrap around when they reach
892 * 2**32 - 1. That is, the next TSN a DATA chunk MUST use
893 * after transmitting TSN = 2*32 - 1 is TSN = 0.
895 __u32 retval
= asoc
->next_tsn
;
902 /* Compare two addresses to see if they match. Wildcard addresses
903 * only match themselves.
905 int sctp_cmp_addr_exact(const union sctp_addr
*ss1
,
906 const union sctp_addr
*ss2
)
910 af
= sctp_get_af_specific(ss1
->sa
.sa_family
);
914 return af
->cmp_addr(ss1
, ss2
);
917 /* Return an ecne chunk to get prepended to a packet.
918 * Note: We are sly and return a shared, prealloced chunk. FIXME:
919 * No we don't, but we could/should.
921 struct sctp_chunk
*sctp_get_ecne_prepend(struct sctp_association
*asoc
)
923 if (!asoc
->need_ecne
)
926 /* Send ECNE if needed.
927 * Not being able to allocate a chunk here is not deadly.
929 return sctp_make_ecne(asoc
, asoc
->last_ecne_tsn
);
933 * Find which transport this TSN was sent on.
935 struct sctp_transport
*sctp_assoc_lookup_tsn(struct sctp_association
*asoc
,
938 struct sctp_transport
*active
;
939 struct sctp_transport
*match
;
940 struct sctp_transport
*transport
;
941 struct sctp_chunk
*chunk
;
942 __be32 key
= htonl(tsn
);
947 * FIXME: In general, find a more efficient data structure for
952 * The general strategy is to search each transport's transmitted
953 * list. Return which transport this TSN lives on.
955 * Let's be hopeful and check the active_path first.
956 * Another optimization would be to know if there is only one
957 * outbound path and not have to look for the TSN at all.
961 active
= asoc
->peer
.active_path
;
963 list_for_each_entry(chunk
, &active
->transmitted
,
966 if (key
== chunk
->subh
.data_hdr
->tsn
) {
972 /* If not found, go search all the other transports. */
973 list_for_each_entry(transport
, &asoc
->peer
.transport_addr_list
,
976 if (transport
== active
)
978 list_for_each_entry(chunk
, &transport
->transmitted
,
980 if (key
== chunk
->subh
.data_hdr
->tsn
) {
990 /* Is this the association we are looking for? */
991 struct sctp_transport
*sctp_assoc_is_match(struct sctp_association
*asoc
,
993 const union sctp_addr
*laddr
,
994 const union sctp_addr
*paddr
)
996 struct sctp_transport
*transport
;
998 if ((htons(asoc
->base
.bind_addr
.port
) == laddr
->v4
.sin_port
) &&
999 (htons(asoc
->peer
.port
) == paddr
->v4
.sin_port
) &&
1000 net_eq(sock_net(asoc
->base
.sk
), net
)) {
1001 transport
= sctp_assoc_lookup_paddr(asoc
, paddr
);
1005 if (sctp_bind_addr_match(&asoc
->base
.bind_addr
, laddr
,
1006 sctp_sk(asoc
->base
.sk
)))
1015 /* Do delayed input processing. This is scheduled by sctp_rcv(). */
1016 static void sctp_assoc_bh_rcv(struct work_struct
*work
)
1018 struct sctp_association
*asoc
=
1019 container_of(work
, struct sctp_association
,
1020 base
.inqueue
.immediate
);
1021 struct net
*net
= sock_net(asoc
->base
.sk
);
1022 struct sctp_endpoint
*ep
;
1023 struct sctp_chunk
*chunk
;
1024 struct sctp_inq
*inqueue
;
1026 sctp_subtype_t subtype
;
1029 /* The association should be held so we should be safe. */
1032 inqueue
= &asoc
->base
.inqueue
;
1033 sctp_association_hold(asoc
);
1034 while (NULL
!= (chunk
= sctp_inq_pop(inqueue
))) {
1035 state
= asoc
->state
;
1036 subtype
= SCTP_ST_CHUNK(chunk
->chunk_hdr
->type
);
1038 /* SCTP-AUTH, Section 6.3:
1039 * The receiver has a list of chunk types which it expects
1040 * to be received only after an AUTH-chunk. This list has
1041 * been sent to the peer during the association setup. It
1042 * MUST silently discard these chunks if they are not placed
1043 * after an AUTH chunk in the packet.
1045 if (sctp_auth_recv_cid(subtype
.chunk
, asoc
) && !chunk
->auth
)
1048 /* Remember where the last DATA chunk came from so we
1049 * know where to send the SACK.
1051 if (sctp_chunk_is_data(chunk
))
1052 asoc
->peer
.last_data_from
= chunk
->transport
;
1054 SCTP_INC_STATS(net
, SCTP_MIB_INCTRLCHUNKS
);
1055 asoc
->stats
.ictrlchunks
++;
1056 if (chunk
->chunk_hdr
->type
== SCTP_CID_SACK
)
1057 asoc
->stats
.isacks
++;
1060 if (chunk
->transport
)
1061 chunk
->transport
->last_time_heard
= ktime_get();
1063 /* Run through the state machine. */
1064 error
= sctp_do_sm(net
, SCTP_EVENT_T_CHUNK
, subtype
,
1065 state
, ep
, asoc
, chunk
, GFP_ATOMIC
);
1067 /* Check to see if the association is freed in response to
1068 * the incoming chunk. If so, get out of the while loop.
1070 if (asoc
->base
.dead
)
1073 /* If there is an error on chunk, discard this packet. */
1075 chunk
->pdiscard
= 1;
1077 sctp_association_put(asoc
);
1080 /* This routine moves an association from its old sk to a new sk. */
1081 void sctp_assoc_migrate(struct sctp_association
*assoc
, struct sock
*newsk
)
1083 struct sctp_sock
*newsp
= sctp_sk(newsk
);
1084 struct sock
*oldsk
= assoc
->base
.sk
;
1086 /* Delete the association from the old endpoint's list of
1089 list_del_init(&assoc
->asocs
);
1091 /* Decrement the backlog value for a TCP-style socket. */
1092 if (sctp_style(oldsk
, TCP
))
1093 oldsk
->sk_ack_backlog
--;
1095 /* Release references to the old endpoint and the sock. */
1096 sctp_endpoint_put(assoc
->ep
);
1097 sock_put(assoc
->base
.sk
);
1099 /* Get a reference to the new endpoint. */
1100 assoc
->ep
= newsp
->ep
;
1101 sctp_endpoint_hold(assoc
->ep
);
1103 /* Get a reference to the new sock. */
1104 assoc
->base
.sk
= newsk
;
1105 sock_hold(assoc
->base
.sk
);
1107 /* Add the association to the new endpoint's list of associations. */
1108 sctp_endpoint_add_asoc(newsp
->ep
, assoc
);
1111 /* Update an association (possibly from unexpected COOKIE-ECHO processing). */
1112 void sctp_assoc_update(struct sctp_association
*asoc
,
1113 struct sctp_association
*new)
1115 struct sctp_transport
*trans
;
1116 struct list_head
*pos
, *temp
;
1118 /* Copy in new parameters of peer. */
1120 asoc
->peer
.rwnd
= new->peer
.rwnd
;
1121 asoc
->peer
.sack_needed
= new->peer
.sack_needed
;
1122 asoc
->peer
.auth_capable
= new->peer
.auth_capable
;
1123 asoc
->peer
.i
= new->peer
.i
;
1124 sctp_tsnmap_init(&asoc
->peer
.tsn_map
, SCTP_TSN_MAP_INITIAL
,
1125 asoc
->peer
.i
.initial_tsn
, GFP_ATOMIC
);
1127 /* Remove any peer addresses not present in the new association. */
1128 list_for_each_safe(pos
, temp
, &asoc
->peer
.transport_addr_list
) {
1129 trans
= list_entry(pos
, struct sctp_transport
, transports
);
1130 if (!sctp_assoc_lookup_paddr(new, &trans
->ipaddr
)) {
1131 sctp_assoc_rm_peer(asoc
, trans
);
1135 if (asoc
->state
>= SCTP_STATE_ESTABLISHED
)
1136 sctp_transport_reset(trans
);
1139 /* If the case is A (association restart), use
1140 * initial_tsn as next_tsn. If the case is B, use
1141 * current next_tsn in case data sent to peer
1142 * has been discarded and needs retransmission.
1144 if (asoc
->state
>= SCTP_STATE_ESTABLISHED
) {
1145 asoc
->next_tsn
= new->next_tsn
;
1146 asoc
->ctsn_ack_point
= new->ctsn_ack_point
;
1147 asoc
->adv_peer_ack_point
= new->adv_peer_ack_point
;
1149 /* Reinitialize SSN for both local streams
1150 * and peer's streams.
1152 sctp_stream_clear(asoc
->stream
);
1154 /* Flush the ULP reassembly and ordered queue.
1155 * Any data there will now be stale and will
1158 sctp_ulpq_flush(&asoc
->ulpq
);
1160 /* reset the overall association error count so
1161 * that the restarted association doesn't get torn
1162 * down on the next retransmission timer.
1164 asoc
->overall_error_count
= 0;
1167 /* Add any peer addresses from the new association. */
1168 list_for_each_entry(trans
, &new->peer
.transport_addr_list
,
1170 if (!sctp_assoc_lookup_paddr(asoc
, &trans
->ipaddr
))
1171 sctp_assoc_add_peer(asoc
, &trans
->ipaddr
,
1172 GFP_ATOMIC
, trans
->state
);
1175 asoc
->ctsn_ack_point
= asoc
->next_tsn
- 1;
1176 asoc
->adv_peer_ack_point
= asoc
->ctsn_ack_point
;
1177 if (!asoc
->stream
) {
1178 asoc
->stream
= new->stream
;
1182 if (!asoc
->assoc_id
) {
1183 /* get a new association id since we don't have one
1186 sctp_assoc_set_id(asoc
, GFP_ATOMIC
);
1190 /* SCTP-AUTH: Save the peer parameters from the new associations
1191 * and also move the association shared keys over
1193 kfree(asoc
->peer
.peer_random
);
1194 asoc
->peer
.peer_random
= new->peer
.peer_random
;
1195 new->peer
.peer_random
= NULL
;
1197 kfree(asoc
->peer
.peer_chunks
);
1198 asoc
->peer
.peer_chunks
= new->peer
.peer_chunks
;
1199 new->peer
.peer_chunks
= NULL
;
1201 kfree(asoc
->peer
.peer_hmacs
);
1202 asoc
->peer
.peer_hmacs
= new->peer
.peer_hmacs
;
1203 new->peer
.peer_hmacs
= NULL
;
1205 sctp_auth_asoc_init_active_key(asoc
, GFP_ATOMIC
);
1208 /* Update the retran path for sending a retransmitted packet.
1209 * See also RFC4960, 6.4. Multi-Homed SCTP Endpoints:
1211 * When there is outbound data to send and the primary path
1212 * becomes inactive (e.g., due to failures), or where the
1213 * SCTP user explicitly requests to send data to an
1214 * inactive destination transport address, before reporting
1215 * an error to its ULP, the SCTP endpoint should try to send
1216 * the data to an alternate active destination transport
1217 * address if one exists.
1219 * When retransmitting data that timed out, if the endpoint
1220 * is multihomed, it should consider each source-destination
1221 * address pair in its retransmission selection policy.
1222 * When retransmitting timed-out data, the endpoint should
1223 * attempt to pick the most divergent source-destination
1224 * pair from the original source-destination pair to which
1225 * the packet was transmitted.
1227 * Note: Rules for picking the most divergent source-destination
1228 * pair are an implementation decision and are not specified
1229 * within this document.
1231 * Our basic strategy is to round-robin transports in priorities
1232 * according to sctp_trans_score() e.g., if no such
1233 * transport with state SCTP_ACTIVE exists, round-robin through
1234 * SCTP_UNKNOWN, etc. You get the picture.
1236 static u8
sctp_trans_score(const struct sctp_transport
*trans
)
1238 switch (trans
->state
) {
1240 return 3; /* best case */
1245 default: /* case SCTP_INACTIVE */
1246 return 0; /* worst case */
1250 static struct sctp_transport
*sctp_trans_elect_tie(struct sctp_transport
*trans1
,
1251 struct sctp_transport
*trans2
)
1253 if (trans1
->error_count
> trans2
->error_count
) {
1255 } else if (trans1
->error_count
== trans2
->error_count
&&
1256 ktime_after(trans2
->last_time_heard
,
1257 trans1
->last_time_heard
)) {
1264 static struct sctp_transport
*sctp_trans_elect_best(struct sctp_transport
*curr
,
1265 struct sctp_transport
*best
)
1267 u8 score_curr
, score_best
;
1269 if (best
== NULL
|| curr
== best
)
1272 score_curr
= sctp_trans_score(curr
);
1273 score_best
= sctp_trans_score(best
);
1275 /* First, try a score-based selection if both transport states
1276 * differ. If we're in a tie, lets try to make a more clever
1277 * decision here based on error counts and last time heard.
1279 if (score_curr
> score_best
)
1281 else if (score_curr
== score_best
)
1282 return sctp_trans_elect_tie(best
, curr
);
1287 void sctp_assoc_update_retran_path(struct sctp_association
*asoc
)
1289 struct sctp_transport
*trans
= asoc
->peer
.retran_path
;
1290 struct sctp_transport
*trans_next
= NULL
;
1292 /* We're done as we only have the one and only path. */
1293 if (asoc
->peer
.transport_count
== 1)
1295 /* If active_path and retran_path are the same and active,
1296 * then this is the only active path. Use it.
1298 if (asoc
->peer
.active_path
== asoc
->peer
.retran_path
&&
1299 asoc
->peer
.active_path
->state
== SCTP_ACTIVE
)
1302 /* Iterate from retran_path's successor back to retran_path. */
1303 for (trans
= list_next_entry(trans
, transports
); 1;
1304 trans
= list_next_entry(trans
, transports
)) {
1305 /* Manually skip the head element. */
1306 if (&trans
->transports
== &asoc
->peer
.transport_addr_list
)
1308 if (trans
->state
== SCTP_UNCONFIRMED
)
1310 trans_next
= sctp_trans_elect_best(trans
, trans_next
);
1311 /* Active is good enough for immediate return. */
1312 if (trans_next
->state
== SCTP_ACTIVE
)
1314 /* We've reached the end, time to update path. */
1315 if (trans
== asoc
->peer
.retran_path
)
1319 asoc
->peer
.retran_path
= trans_next
;
1321 pr_debug("%s: association:%p updated new path to addr:%pISpc\n",
1322 __func__
, asoc
, &asoc
->peer
.retran_path
->ipaddr
.sa
);
1325 static void sctp_select_active_and_retran_path(struct sctp_association
*asoc
)
1327 struct sctp_transport
*trans
, *trans_pri
= NULL
, *trans_sec
= NULL
;
1328 struct sctp_transport
*trans_pf
= NULL
;
1330 /* Look for the two most recently used active transports. */
1331 list_for_each_entry(trans
, &asoc
->peer
.transport_addr_list
,
1333 /* Skip uninteresting transports. */
1334 if (trans
->state
== SCTP_INACTIVE
||
1335 trans
->state
== SCTP_UNCONFIRMED
)
1337 /* Keep track of the best PF transport from our
1338 * list in case we don't find an active one.
1340 if (trans
->state
== SCTP_PF
) {
1341 trans_pf
= sctp_trans_elect_best(trans
, trans_pf
);
1344 /* For active transports, pick the most recent ones. */
1345 if (trans_pri
== NULL
||
1346 ktime_after(trans
->last_time_heard
,
1347 trans_pri
->last_time_heard
)) {
1348 trans_sec
= trans_pri
;
1350 } else if (trans_sec
== NULL
||
1351 ktime_after(trans
->last_time_heard
,
1352 trans_sec
->last_time_heard
)) {
1357 /* RFC 2960 6.4 Multi-Homed SCTP Endpoints
1359 * By default, an endpoint should always transmit to the primary
1360 * path, unless the SCTP user explicitly specifies the
1361 * destination transport address (and possibly source transport
1362 * address) to use. [If the primary is active but not most recent,
1363 * bump the most recently used transport.]
1365 if ((asoc
->peer
.primary_path
->state
== SCTP_ACTIVE
||
1366 asoc
->peer
.primary_path
->state
== SCTP_UNKNOWN
) &&
1367 asoc
->peer
.primary_path
!= trans_pri
) {
1368 trans_sec
= trans_pri
;
1369 trans_pri
= asoc
->peer
.primary_path
;
1372 /* We did not find anything useful for a possible retransmission
1373 * path; either primary path that we found is the the same as
1374 * the current one, or we didn't generally find an active one.
1376 if (trans_sec
== NULL
)
1377 trans_sec
= trans_pri
;
1379 /* If we failed to find a usable transport, just camp on the
1380 * active or pick a PF iff it's the better choice.
1382 if (trans_pri
== NULL
) {
1383 trans_pri
= sctp_trans_elect_best(asoc
->peer
.active_path
, trans_pf
);
1384 trans_sec
= trans_pri
;
1387 /* Set the active and retran transports. */
1388 asoc
->peer
.active_path
= trans_pri
;
1389 asoc
->peer
.retran_path
= trans_sec
;
1392 struct sctp_transport
*
1393 sctp_assoc_choose_alter_transport(struct sctp_association
*asoc
,
1394 struct sctp_transport
*last_sent_to
)
1396 /* If this is the first time packet is sent, use the active path,
1397 * else use the retran path. If the last packet was sent over the
1398 * retran path, update the retran path and use it.
1400 if (last_sent_to
== NULL
) {
1401 return asoc
->peer
.active_path
;
1403 if (last_sent_to
== asoc
->peer
.retran_path
)
1404 sctp_assoc_update_retran_path(asoc
);
1406 return asoc
->peer
.retran_path
;
1410 /* Update the association's pmtu and frag_point by going through all the
1411 * transports. This routine is called when a transport's PMTU has changed.
1413 void sctp_assoc_sync_pmtu(struct sock
*sk
, struct sctp_association
*asoc
)
1415 struct sctp_transport
*t
;
1421 /* Get the lowest pmtu of all the transports. */
1422 list_for_each_entry(t
, &asoc
->peer
.transport_addr_list
,
1424 if (t
->pmtu_pending
&& t
->dst
) {
1425 sctp_transport_update_pmtu(sk
, t
,
1426 SCTP_TRUNC4(dst_mtu(t
->dst
)));
1427 t
->pmtu_pending
= 0;
1429 if (!pmtu
|| (t
->pathmtu
< pmtu
))
1434 asoc
->pathmtu
= pmtu
;
1435 asoc
->frag_point
= sctp_frag_point(asoc
, pmtu
);
1438 pr_debug("%s: asoc:%p, pmtu:%d, frag_point:%d\n", __func__
, asoc
,
1439 asoc
->pathmtu
, asoc
->frag_point
);
1442 /* Should we send a SACK to update our peer? */
1443 static inline bool sctp_peer_needs_update(struct sctp_association
*asoc
)
1445 struct net
*net
= sock_net(asoc
->base
.sk
);
1446 switch (asoc
->state
) {
1447 case SCTP_STATE_ESTABLISHED
:
1448 case SCTP_STATE_SHUTDOWN_PENDING
:
1449 case SCTP_STATE_SHUTDOWN_RECEIVED
:
1450 case SCTP_STATE_SHUTDOWN_SENT
:
1451 if ((asoc
->rwnd
> asoc
->a_rwnd
) &&
1452 ((asoc
->rwnd
- asoc
->a_rwnd
) >= max_t(__u32
,
1453 (asoc
->base
.sk
->sk_rcvbuf
>> net
->sctp
.rwnd_upd_shift
),
1463 /* Increase asoc's rwnd by len and send any window update SACK if needed. */
1464 void sctp_assoc_rwnd_increase(struct sctp_association
*asoc
, unsigned int len
)
1466 struct sctp_chunk
*sack
;
1467 struct timer_list
*timer
;
1469 if (asoc
->rwnd_over
) {
1470 if (asoc
->rwnd_over
>= len
) {
1471 asoc
->rwnd_over
-= len
;
1473 asoc
->rwnd
+= (len
- asoc
->rwnd_over
);
1474 asoc
->rwnd_over
= 0;
1480 /* If we had window pressure, start recovering it
1481 * once our rwnd had reached the accumulated pressure
1482 * threshold. The idea is to recover slowly, but up
1483 * to the initial advertised window.
1485 if (asoc
->rwnd_press
) {
1486 int change
= min(asoc
->pathmtu
, asoc
->rwnd_press
);
1487 asoc
->rwnd
+= change
;
1488 asoc
->rwnd_press
-= change
;
1491 pr_debug("%s: asoc:%p rwnd increased by %d to (%u, %u) - %u\n",
1492 __func__
, asoc
, len
, asoc
->rwnd
, asoc
->rwnd_over
,
1495 /* Send a window update SACK if the rwnd has increased by at least the
1496 * minimum of the association's PMTU and half of the receive buffer.
1497 * The algorithm used is similar to the one described in
1498 * Section 4.2.3.3 of RFC 1122.
1500 if (sctp_peer_needs_update(asoc
)) {
1501 asoc
->a_rwnd
= asoc
->rwnd
;
1503 pr_debug("%s: sending window update SACK- asoc:%p rwnd:%u "
1504 "a_rwnd:%u\n", __func__
, asoc
, asoc
->rwnd
,
1507 sack
= sctp_make_sack(asoc
);
1511 asoc
->peer
.sack_needed
= 0;
1513 sctp_outq_tail(&asoc
->outqueue
, sack
, GFP_ATOMIC
);
1515 /* Stop the SACK timer. */
1516 timer
= &asoc
->timers
[SCTP_EVENT_TIMEOUT_SACK
];
1517 if (del_timer(timer
))
1518 sctp_association_put(asoc
);
1522 /* Decrease asoc's rwnd by len. */
1523 void sctp_assoc_rwnd_decrease(struct sctp_association
*asoc
, unsigned int len
)
1528 if (unlikely(!asoc
->rwnd
|| asoc
->rwnd_over
))
1529 pr_debug("%s: association:%p has asoc->rwnd:%u, "
1530 "asoc->rwnd_over:%u!\n", __func__
, asoc
,
1531 asoc
->rwnd
, asoc
->rwnd_over
);
1533 if (asoc
->ep
->rcvbuf_policy
)
1534 rx_count
= atomic_read(&asoc
->rmem_alloc
);
1536 rx_count
= atomic_read(&asoc
->base
.sk
->sk_rmem_alloc
);
1538 /* If we've reached or overflowed our receive buffer, announce
1539 * a 0 rwnd if rwnd would still be positive. Store the
1540 * the potential pressure overflow so that the window can be restored
1541 * back to original value.
1543 if (rx_count
>= asoc
->base
.sk
->sk_rcvbuf
)
1546 if (asoc
->rwnd
>= len
) {
1549 asoc
->rwnd_press
+= asoc
->rwnd
;
1553 asoc
->rwnd_over
+= len
- asoc
->rwnd
;
1557 pr_debug("%s: asoc:%p rwnd decreased by %d to (%u, %u, %u)\n",
1558 __func__
, asoc
, len
, asoc
->rwnd
, asoc
->rwnd_over
,
1562 /* Build the bind address list for the association based on info from the
1563 * local endpoint and the remote peer.
1565 int sctp_assoc_set_bind_addr_from_ep(struct sctp_association
*asoc
,
1566 sctp_scope_t scope
, gfp_t gfp
)
1570 /* Use scoping rules to determine the subset of addresses from
1573 flags
= (PF_INET6
== asoc
->base
.sk
->sk_family
) ? SCTP_ADDR6_ALLOWED
: 0;
1574 if (asoc
->peer
.ipv4_address
)
1575 flags
|= SCTP_ADDR4_PEERSUPP
;
1576 if (asoc
->peer
.ipv6_address
)
1577 flags
|= SCTP_ADDR6_PEERSUPP
;
1579 return sctp_bind_addr_copy(sock_net(asoc
->base
.sk
),
1580 &asoc
->base
.bind_addr
,
1581 &asoc
->ep
->base
.bind_addr
,
1585 /* Build the association's bind address list from the cookie. */
1586 int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association
*asoc
,
1587 struct sctp_cookie
*cookie
,
1590 int var_size2
= ntohs(cookie
->peer_init
->chunk_hdr
.length
);
1591 int var_size3
= cookie
->raw_addr_list_len
;
1592 __u8
*raw
= (__u8
*)cookie
->peer_init
+ var_size2
;
1594 return sctp_raw_to_bind_addrs(&asoc
->base
.bind_addr
, raw
, var_size3
,
1595 asoc
->ep
->base
.bind_addr
.port
, gfp
);
1598 /* Lookup laddr in the bind address list of an association. */
1599 int sctp_assoc_lookup_laddr(struct sctp_association
*asoc
,
1600 const union sctp_addr
*laddr
)
1604 if ((asoc
->base
.bind_addr
.port
== ntohs(laddr
->v4
.sin_port
)) &&
1605 sctp_bind_addr_match(&asoc
->base
.bind_addr
, laddr
,
1606 sctp_sk(asoc
->base
.sk
)))
1612 /* Set an association id for a given association */
1613 int sctp_assoc_set_id(struct sctp_association
*asoc
, gfp_t gfp
)
1615 bool preload
= gfpflags_allow_blocking(gfp
);
1618 /* If the id is already assigned, keep it. */
1624 spin_lock_bh(&sctp_assocs_id_lock
);
1625 /* 0 is not a valid assoc_id, must be >= 1 */
1626 ret
= idr_alloc_cyclic(&sctp_assocs_id
, asoc
, 1, 0, GFP_NOWAIT
);
1627 spin_unlock_bh(&sctp_assocs_id_lock
);
1633 asoc
->assoc_id
= (sctp_assoc_t
)ret
;
1637 /* Free the ASCONF queue */
1638 static void sctp_assoc_free_asconf_queue(struct sctp_association
*asoc
)
1640 struct sctp_chunk
*asconf
;
1641 struct sctp_chunk
*tmp
;
1643 list_for_each_entry_safe(asconf
, tmp
, &asoc
->addip_chunk_list
, list
) {
1644 list_del_init(&asconf
->list
);
1645 sctp_chunk_free(asconf
);
1649 /* Free asconf_ack cache */
1650 static void sctp_assoc_free_asconf_acks(struct sctp_association
*asoc
)
1652 struct sctp_chunk
*ack
;
1653 struct sctp_chunk
*tmp
;
1655 list_for_each_entry_safe(ack
, tmp
, &asoc
->asconf_ack_list
,
1657 list_del_init(&ack
->transmitted_list
);
1658 sctp_chunk_free(ack
);
1662 /* Clean up the ASCONF_ACK queue */
1663 void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association
*asoc
)
1665 struct sctp_chunk
*ack
;
1666 struct sctp_chunk
*tmp
;
1668 /* We can remove all the entries from the queue up to
1669 * the "Peer-Sequence-Number".
1671 list_for_each_entry_safe(ack
, tmp
, &asoc
->asconf_ack_list
,
1673 if (ack
->subh
.addip_hdr
->serial
==
1674 htonl(asoc
->peer
.addip_serial
))
1677 list_del_init(&ack
->transmitted_list
);
1678 sctp_chunk_free(ack
);
1682 /* Find the ASCONF_ACK whose serial number matches ASCONF */
1683 struct sctp_chunk
*sctp_assoc_lookup_asconf_ack(
1684 const struct sctp_association
*asoc
,
1687 struct sctp_chunk
*ack
;
1689 /* Walk through the list of cached ASCONF-ACKs and find the
1690 * ack chunk whose serial number matches that of the request.
1692 list_for_each_entry(ack
, &asoc
->asconf_ack_list
, transmitted_list
) {
1693 if (sctp_chunk_pending(ack
))
1695 if (ack
->subh
.addip_hdr
->serial
== serial
) {
1696 sctp_chunk_hold(ack
);
1704 void sctp_asconf_queue_teardown(struct sctp_association
*asoc
)
1706 /* Free any cached ASCONF_ACK chunk. */
1707 sctp_assoc_free_asconf_acks(asoc
);
1709 /* Free the ASCONF queue. */
1710 sctp_assoc_free_asconf_queue(asoc
);
1712 /* Free any cached ASCONF chunk. */
1713 if (asoc
->addip_last_asconf
)
1714 sctp_chunk_free(asoc
->addip_last_asconf
);