1 /* SCTP kernel implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
6 * This file is part of the SCTP kernel implementation
8 * These functions work with the state functions in sctp_sm_statefuns.c
9 * to implement that state operations. These functions implement the
10 * steps which require modifying existing data structures.
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@austin.ibm.com>
36 * Hui Huang <hui.huang@nokia.com>
37 * Dajiang Zhang <dajiang.zhang@nokia.com>
38 * Daisy Chang <daisyc@us.ibm.com>
39 * Sridhar Samudrala <sri@us.ibm.com>
40 * Ardelle Fan <ardelle.fan@intel.com>
43 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
45 #include <linux/skbuff.h>
46 #include <linux/types.h>
47 #include <linux/socket.h>
49 #include <linux/gfp.h>
51 #include <net/sctp/sctp.h>
52 #include <net/sctp/sm.h>
53 #include <net/sctp/stream_sched.h>
55 static int sctp_cmd_interpreter(enum sctp_event event_type,
56 union sctp_subtype subtype,
57 enum sctp_state state,
58 struct sctp_endpoint *ep,
59 struct sctp_association *asoc,
61 enum sctp_disposition status,
62 struct sctp_cmd_seq *commands,
64 static int sctp_side_effects(enum sctp_event event_type,
65 union sctp_subtype subtype,
66 enum sctp_state state,
67 struct sctp_endpoint *ep,
68 struct sctp_association **asoc,
70 enum sctp_disposition status,
71 struct sctp_cmd_seq *commands,
74 /********************************************************************
76 ********************************************************************/
78 /* A helper function for delayed processing of INET ECN CE bit. */
79 static void sctp_do_ecn_ce_work(struct sctp_association *asoc,
82 /* Save the TSN away for comparison when we receive CWR */
84 asoc->last_ecne_tsn = lowest_tsn;
88 /* Helper function for delayed processing of SCTP ECNE chunk. */
89 /* RFC 2960 Appendix A
91 * RFC 2481 details a specific bit for a sender to send in
92 * the header of its next outbound TCP segment to indicate to
93 * its peer that it has reduced its congestion window. This
94 * is termed the CWR bit. For SCTP the same indication is made
95 * by including the CWR chunk. This chunk contains one data
96 * element, i.e. the TSN number that was sent in the ECNE chunk.
97 * This element represents the lowest TSN number in the datagram
98 * that was originally marked with the CE bit.
100 static struct sctp_chunk *sctp_do_ecn_ecne_work(struct sctp_association *asoc,
102 struct sctp_chunk *chunk)
104 struct sctp_chunk *repl;
106 /* Our previously transmitted packet ran into some congestion
107 * so we should take action by reducing cwnd and ssthresh
108 * and then ACK our peer that we we've done so by
112 /* First, try to determine if we want to actually lower
113 * our cwnd variables. Only lower them if the ECNE looks more
114 * recent than the last response.
116 if (TSN_lt(asoc->last_cwr_tsn, lowest_tsn)) {
117 struct sctp_transport *transport;
119 /* Find which transport's congestion variables
120 * need to be adjusted.
122 transport = sctp_assoc_lookup_tsn(asoc, lowest_tsn);
124 /* Update the congestion variables. */
126 sctp_transport_lower_cwnd(transport,
127 SCTP_LOWER_CWND_ECNE);
128 asoc->last_cwr_tsn = lowest_tsn;
131 /* Always try to quiet the other end. In case of lost CWR,
132 * resend last_cwr_tsn.
134 repl = sctp_make_cwr(asoc, asoc->last_cwr_tsn, chunk);
136 /* If we run out of memory, it will look like a lost CWR. We'll
137 * get back in sync eventually.
142 /* Helper function to do delayed processing of ECN CWR chunk. */
143 static void sctp_do_ecn_cwr_work(struct sctp_association *asoc,
146 /* Turn off ECNE getting auto-prepended to every outgoing
152 /* Generate SACK if necessary. We call this at the end of a packet. */
153 static int sctp_gen_sack(struct sctp_association *asoc, int force,
154 struct sctp_cmd_seq *commands)
156 struct sctp_transport *trans = asoc->peer.last_data_from;
157 __u32 ctsn, max_tsn_seen;
158 struct sctp_chunk *sack;
162 (!trans && (asoc->param_flags & SPP_SACKDELAY_DISABLE)) ||
163 (trans && (trans->param_flags & SPP_SACKDELAY_DISABLE)))
164 asoc->peer.sack_needed = 1;
166 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
167 max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
169 /* From 12.2 Parameters necessary per association (i.e. the TCB):
171 * Ack State : This flag indicates if the next received packet
172 * : is to be responded to with a SACK. ...
173 * : When DATA chunks are out of order, SACK's
174 * : are not delayed (see Section 6).
176 * [This is actually not mentioned in Section 6, but we
177 * implement it here anyway. --piggy]
179 if (max_tsn_seen != ctsn)
180 asoc->peer.sack_needed = 1;
182 /* From 6.2 Acknowledgement on Reception of DATA Chunks:
184 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically,
185 * an acknowledgement SHOULD be generated for at least every
186 * second packet (not every second DATA chunk) received, and
187 * SHOULD be generated within 200 ms of the arrival of any
188 * unacknowledged DATA chunk. ...
190 if (!asoc->peer.sack_needed) {
191 asoc->peer.sack_cnt++;
193 /* Set the SACK delay timeout based on the
194 * SACK delay for the last transport
195 * data was received from, or the default
196 * for the association.
199 /* We will need a SACK for the next packet. */
200 if (asoc->peer.sack_cnt >= trans->sackfreq - 1)
201 asoc->peer.sack_needed = 1;
203 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
206 /* We will need a SACK for the next packet. */
207 if (asoc->peer.sack_cnt >= asoc->sackfreq - 1)
208 asoc->peer.sack_needed = 1;
210 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
214 /* Restart the SACK timer. */
215 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
216 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
218 __u32 old_a_rwnd = asoc->a_rwnd;
220 asoc->a_rwnd = asoc->rwnd;
221 sack = sctp_make_sack(asoc);
223 asoc->a_rwnd = old_a_rwnd;
227 asoc->peer.sack_needed = 0;
228 asoc->peer.sack_cnt = 0;
230 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(sack));
232 /* Stop the SACK timer. */
233 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
234 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
243 /* When the T3-RTX timer expires, it calls this function to create the
244 * relevant state machine event.
246 void sctp_generate_t3_rtx_event(struct timer_list *t)
248 struct sctp_transport *transport =
249 from_timer(transport, t, T3_rtx_timer);
250 struct sctp_association *asoc = transport->asoc;
251 struct sock *sk = asoc->base.sk;
252 struct net *net = sock_net(sk);
255 /* Check whether a task is in the sock. */
258 if (sock_owned_by_user(sk)) {
259 pr_debug("%s: sock is busy\n", __func__);
261 /* Try again later. */
262 if (!mod_timer(&transport->T3_rtx_timer, jiffies + (HZ/20)))
263 sctp_transport_hold(transport);
267 /* Run through the state machine. */
268 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
269 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX),
272 transport, GFP_ATOMIC);
279 sctp_transport_put(transport);
282 /* This is a sa interface for producing timeout events. It works
283 * for timeouts which use the association as their parameter.
285 static void sctp_generate_timeout_event(struct sctp_association *asoc,
286 enum sctp_event_timeout timeout_type)
288 struct sock *sk = asoc->base.sk;
289 struct net *net = sock_net(sk);
293 if (sock_owned_by_user(sk)) {
294 pr_debug("%s: sock is busy: timer %d\n", __func__,
297 /* Try again later. */
298 if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20)))
299 sctp_association_hold(asoc);
303 /* Is this association really dead and just waiting around for
304 * the timer to let go of the reference?
309 /* Run through the state machine. */
310 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
311 SCTP_ST_TIMEOUT(timeout_type),
312 asoc->state, asoc->ep, asoc,
313 (void *)timeout_type, GFP_ATOMIC);
320 sctp_association_put(asoc);
323 static void sctp_generate_t1_cookie_event(struct timer_list *t)
325 struct sctp_association *asoc =
326 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_T1_COOKIE]);
328 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
331 static void sctp_generate_t1_init_event(struct timer_list *t)
333 struct sctp_association *asoc =
334 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_T1_INIT]);
336 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
339 static void sctp_generate_t2_shutdown_event(struct timer_list *t)
341 struct sctp_association *asoc =
342 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN]);
344 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
347 static void sctp_generate_t4_rto_event(struct timer_list *t)
349 struct sctp_association *asoc =
350 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_T4_RTO]);
352 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
355 static void sctp_generate_t5_shutdown_guard_event(struct timer_list *t)
357 struct sctp_association *asoc =
359 timers[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD]);
361 sctp_generate_timeout_event(asoc,
362 SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);
364 } /* sctp_generate_t5_shutdown_guard_event() */
366 static void sctp_generate_autoclose_event(struct timer_list *t)
368 struct sctp_association *asoc =
369 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_AUTOCLOSE]);
371 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE);
374 /* Generate a heart beat event. If the sock is busy, reschedule. Make
375 * sure that the transport is still valid.
377 void sctp_generate_heartbeat_event(struct timer_list *t)
379 struct sctp_transport *transport = from_timer(transport, t, hb_timer);
380 struct sctp_association *asoc = transport->asoc;
381 struct sock *sk = asoc->base.sk;
382 struct net *net = sock_net(sk);
383 u32 elapsed, timeout;
387 if (sock_owned_by_user(sk)) {
388 pr_debug("%s: sock is busy\n", __func__);
390 /* Try again later. */
391 if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20)))
392 sctp_transport_hold(transport);
396 /* Check if we should still send the heartbeat or reschedule */
397 elapsed = jiffies - transport->last_time_sent;
398 timeout = sctp_transport_timeout(transport);
399 if (elapsed < timeout) {
400 elapsed = timeout - elapsed;
401 if (!mod_timer(&transport->hb_timer, jiffies + elapsed))
402 sctp_transport_hold(transport);
406 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
407 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
408 asoc->state, asoc->ep, asoc,
409 transport, GFP_ATOMIC);
416 sctp_transport_put(transport);
419 /* Handle the timeout of the ICMP protocol unreachable timer. Trigger
420 * the correct state machine transition that will close the association.
422 void sctp_generate_proto_unreach_event(struct timer_list *t)
424 struct sctp_transport *transport =
425 from_timer(transport, t, proto_unreach_timer);
426 struct sctp_association *asoc = transport->asoc;
427 struct sock *sk = asoc->base.sk;
428 struct net *net = sock_net(sk);
431 if (sock_owned_by_user(sk)) {
432 pr_debug("%s: sock is busy\n", __func__);
434 /* Try again later. */
435 if (!mod_timer(&transport->proto_unreach_timer,
437 sctp_transport_hold(transport);
441 /* Is this structure just waiting around for us to actually
447 sctp_do_sm(net, SCTP_EVENT_T_OTHER,
448 SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH),
449 asoc->state, asoc->ep, asoc, transport, GFP_ATOMIC);
453 sctp_transport_put(transport);
456 /* Handle the timeout of the RE-CONFIG timer. */
457 void sctp_generate_reconf_event(struct timer_list *t)
459 struct sctp_transport *transport =
460 from_timer(transport, t, reconf_timer);
461 struct sctp_association *asoc = transport->asoc;
462 struct sock *sk = asoc->base.sk;
463 struct net *net = sock_net(sk);
467 if (sock_owned_by_user(sk)) {
468 pr_debug("%s: sock is busy\n", __func__);
470 /* Try again later. */
471 if (!mod_timer(&transport->reconf_timer, jiffies + (HZ / 20)))
472 sctp_transport_hold(transport);
476 /* This happens when the response arrives after the timer is triggered. */
477 if (!asoc->strreset_chunk)
480 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
481 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_RECONF),
482 asoc->state, asoc->ep, asoc,
483 transport, GFP_ATOMIC);
490 sctp_transport_put(transport);
493 /* Inject a SACK Timeout event into the state machine. */
494 static void sctp_generate_sack_event(struct timer_list *t)
496 struct sctp_association *asoc =
497 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_SACK]);
499 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
502 sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
503 [SCTP_EVENT_TIMEOUT_NONE] = NULL,
504 [SCTP_EVENT_TIMEOUT_T1_COOKIE] = sctp_generate_t1_cookie_event,
505 [SCTP_EVENT_TIMEOUT_T1_INIT] = sctp_generate_t1_init_event,
506 [SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = sctp_generate_t2_shutdown_event,
507 [SCTP_EVENT_TIMEOUT_T3_RTX] = NULL,
508 [SCTP_EVENT_TIMEOUT_T4_RTO] = sctp_generate_t4_rto_event,
509 [SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD] =
510 sctp_generate_t5_shutdown_guard_event,
511 [SCTP_EVENT_TIMEOUT_HEARTBEAT] = NULL,
512 [SCTP_EVENT_TIMEOUT_RECONF] = NULL,
513 [SCTP_EVENT_TIMEOUT_SACK] = sctp_generate_sack_event,
514 [SCTP_EVENT_TIMEOUT_AUTOCLOSE] = sctp_generate_autoclose_event,
518 /* RFC 2960 8.2 Path Failure Detection
520 * When its peer endpoint is multi-homed, an endpoint should keep a
521 * error counter for each of the destination transport addresses of the
524 * Each time the T3-rtx timer expires on any address, or when a
525 * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
526 * the error counter of that destination address will be incremented.
527 * When the value in the error counter exceeds the protocol parameter
528 * 'Path.Max.Retrans' of that destination address, the endpoint should
529 * mark the destination transport address as inactive, and a
530 * notification SHOULD be sent to the upper layer.
533 static void sctp_do_8_2_transport_strike(struct sctp_cmd_seq *commands,
534 struct sctp_association *asoc,
535 struct sctp_transport *transport,
538 struct net *net = sock_net(asoc->base.sk);
540 /* The check for association's overall error counter exceeding the
541 * threshold is done in the state function.
543 /* We are here due to a timer expiration. If the timer was
544 * not a HEARTBEAT, then normal error tracking is done.
545 * If the timer was a heartbeat, we only increment error counts
546 * when we already have an outstanding HEARTBEAT that has not
548 * Additionally, some tranport states inhibit error increments.
551 asoc->overall_error_count++;
552 if (transport->state != SCTP_INACTIVE)
553 transport->error_count++;
554 } else if (transport->hb_sent) {
555 if (transport->state != SCTP_UNCONFIRMED)
556 asoc->overall_error_count++;
557 if (transport->state != SCTP_INACTIVE)
558 transport->error_count++;
561 /* If the transport error count is greater than the pf_retrans
562 * threshold, and less than pathmaxrtx, and if the current state
563 * is SCTP_ACTIVE, then mark this transport as Partially Failed,
564 * see SCTP Quick Failover Draft, section 5.1
566 if (net->sctp.pf_enable &&
567 (transport->state == SCTP_ACTIVE) &&
568 (transport->error_count < transport->pathmaxrxt) &&
569 (transport->error_count > transport->pf_retrans)) {
571 sctp_assoc_control_transport(asoc, transport,
575 /* Update the hb timer to resend a heartbeat every rto */
576 sctp_transport_reset_hb_timer(transport);
579 if (transport->state != SCTP_INACTIVE &&
580 (transport->error_count > transport->pathmaxrxt)) {
581 pr_debug("%s: association:%p transport addr:%pISpc failed\n",
582 __func__, asoc, &transport->ipaddr.sa);
584 sctp_assoc_control_transport(asoc, transport,
586 SCTP_FAILED_THRESHOLD);
589 /* E2) For the destination address for which the timer
590 * expires, set RTO <- RTO * 2 ("back off the timer"). The
591 * maximum value discussed in rule C7 above (RTO.max) may be
592 * used to provide an upper bound to this doubling operation.
594 * Special Case: the first HB doesn't trigger exponential backoff.
595 * The first unacknowledged HB triggers it. We do this with a flag
596 * that indicates that we have an outstanding HB.
598 if (!is_hb || transport->hb_sent) {
599 transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
600 sctp_max_rto(asoc, transport);
604 /* Worker routine to handle INIT command failure. */
605 static void sctp_cmd_init_failed(struct sctp_cmd_seq *commands,
606 struct sctp_association *asoc,
609 struct sctp_ulpevent *event;
611 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_CANT_STR_ASSOC,
612 (__u16)error, 0, 0, NULL,
616 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
617 SCTP_ULPEVENT(event));
619 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
620 SCTP_STATE(SCTP_STATE_CLOSED));
622 /* SEND_FAILED sent later when cleaning up the association. */
623 asoc->outqueue.error = error;
624 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
627 /* Worker routine to handle SCTP_CMD_ASSOC_FAILED. */
628 static void sctp_cmd_assoc_failed(struct sctp_cmd_seq *commands,
629 struct sctp_association *asoc,
630 enum sctp_event event_type,
631 union sctp_subtype subtype,
632 struct sctp_chunk *chunk,
635 struct sctp_ulpevent *event;
636 struct sctp_chunk *abort;
638 /* Cancel any partial delivery in progress. */
639 asoc->stream.si->abort_pd(&asoc->ulpq, GFP_ATOMIC);
641 if (event_type == SCTP_EVENT_T_CHUNK && subtype.chunk == SCTP_CID_ABORT)
642 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
643 (__u16)error, 0, 0, chunk,
646 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
647 (__u16)error, 0, 0, NULL,
650 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
651 SCTP_ULPEVENT(event));
653 if (asoc->overall_error_count >= asoc->max_retrans) {
654 abort = sctp_make_violation_max_retrans(asoc, chunk);
656 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
660 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
661 SCTP_STATE(SCTP_STATE_CLOSED));
663 /* SEND_FAILED sent later when cleaning up the association. */
664 asoc->outqueue.error = error;
665 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
668 /* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
669 * inside the cookie. In reality, this is only used for INIT-ACK processing
670 * since all other cases use "temporary" associations and can do all
671 * their work in statefuns directly.
673 static int sctp_cmd_process_init(struct sctp_cmd_seq *commands,
674 struct sctp_association *asoc,
675 struct sctp_chunk *chunk,
676 struct sctp_init_chunk *peer_init,
681 /* We only process the init as a sideeffect in a single
682 * case. This is when we process the INIT-ACK. If we
683 * fail during INIT processing (due to malloc problems),
684 * just return the error and stop processing the stack.
686 if (!sctp_process_init(asoc, chunk, sctp_source(chunk), peer_init, gfp))
694 /* Helper function to break out starting up of heartbeat timers. */
695 static void sctp_cmd_hb_timers_start(struct sctp_cmd_seq *cmds,
696 struct sctp_association *asoc)
698 struct sctp_transport *t;
700 /* Start a heartbeat timer for each transport on the association.
701 * hold a reference on the transport to make sure none of
702 * the needed data structures go away.
704 list_for_each_entry(t, &asoc->peer.transport_addr_list, transports)
705 sctp_transport_reset_hb_timer(t);
708 static void sctp_cmd_hb_timers_stop(struct sctp_cmd_seq *cmds,
709 struct sctp_association *asoc)
711 struct sctp_transport *t;
713 /* Stop all heartbeat timers. */
715 list_for_each_entry(t, &asoc->peer.transport_addr_list,
717 if (del_timer(&t->hb_timer))
718 sctp_transport_put(t);
722 /* Helper function to stop any pending T3-RTX timers */
723 static void sctp_cmd_t3_rtx_timers_stop(struct sctp_cmd_seq *cmds,
724 struct sctp_association *asoc)
726 struct sctp_transport *t;
728 list_for_each_entry(t, &asoc->peer.transport_addr_list,
730 if (del_timer(&t->T3_rtx_timer))
731 sctp_transport_put(t);
736 /* Helper function to handle the reception of an HEARTBEAT ACK. */
737 static void sctp_cmd_transport_on(struct sctp_cmd_seq *cmds,
738 struct sctp_association *asoc,
739 struct sctp_transport *t,
740 struct sctp_chunk *chunk)
742 struct sctp_sender_hb_info *hbinfo;
743 int was_unconfirmed = 0;
745 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
746 * HEARTBEAT should clear the error counter of the destination
747 * transport address to which the HEARTBEAT was sent.
752 * Although RFC4960 specifies that the overall error count must
753 * be cleared when a HEARTBEAT ACK is received, we make an
754 * exception while in SHUTDOWN PENDING. If the peer keeps its
755 * window shut forever, we may never be able to transmit our
756 * outstanding data and rely on the retransmission limit be reached
757 * to shutdown the association.
759 if (t->asoc->state < SCTP_STATE_SHUTDOWN_PENDING)
760 t->asoc->overall_error_count = 0;
762 /* Clear the hb_sent flag to signal that we had a good
767 /* Mark the destination transport address as active if it is not so
770 if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED)) {
772 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
773 SCTP_HEARTBEAT_SUCCESS);
776 if (t->state == SCTP_PF)
777 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
778 SCTP_HEARTBEAT_SUCCESS);
780 /* HB-ACK was received for a the proper HB. Consider this
784 sctp_transport_dst_confirm(t);
786 /* The receiver of the HEARTBEAT ACK should also perform an
787 * RTT measurement for that destination transport address
788 * using the time value carried in the HEARTBEAT ACK chunk.
789 * If the transport's rto_pending variable has been cleared,
790 * it was most likely due to a retransmit. However, we want
791 * to re-enable it to properly update the rto.
793 if (t->rto_pending == 0)
796 hbinfo = (struct sctp_sender_hb_info *)chunk->skb->data;
797 sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
799 /* Update the heartbeat timer. */
800 sctp_transport_reset_hb_timer(t);
802 if (was_unconfirmed && asoc->peer.transport_count == 1)
803 sctp_transport_immediate_rtx(t);
807 /* Helper function to process the process SACK command. */
808 static int sctp_cmd_process_sack(struct sctp_cmd_seq *cmds,
809 struct sctp_association *asoc,
810 struct sctp_chunk *chunk)
814 if (sctp_outq_sack(&asoc->outqueue, chunk)) {
815 struct net *net = sock_net(asoc->base.sk);
817 /* There are no more TSNs awaiting SACK. */
818 err = sctp_do_sm(net, SCTP_EVENT_T_OTHER,
819 SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
820 asoc->state, asoc->ep, asoc, NULL,
827 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
828 * the transport for a shutdown chunk.
830 static void sctp_cmd_setup_t2(struct sctp_cmd_seq *cmds,
831 struct sctp_association *asoc,
832 struct sctp_chunk *chunk)
834 struct sctp_transport *t;
836 if (chunk->transport)
837 t = chunk->transport;
839 t = sctp_assoc_choose_alter_transport(asoc,
840 asoc->shutdown_last_sent_to);
841 chunk->transport = t;
843 asoc->shutdown_last_sent_to = t;
844 asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
847 static void sctp_cmd_assoc_update(struct sctp_cmd_seq *cmds,
848 struct sctp_association *asoc,
849 struct sctp_association *new)
851 struct net *net = sock_net(asoc->base.sk);
852 struct sctp_chunk *abort;
854 if (!sctp_assoc_update(asoc, new))
857 abort = sctp_make_abort(asoc, NULL, sizeof(struct sctp_errhdr));
859 sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0);
860 sctp_add_cmd_sf(cmds, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
862 sctp_add_cmd_sf(cmds, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNABORTED));
863 sctp_add_cmd_sf(cmds, SCTP_CMD_ASSOC_FAILED,
864 SCTP_PERR(SCTP_ERROR_RSRC_LOW));
865 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
866 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
869 /* Helper function to change the state of an association. */
870 static void sctp_cmd_new_state(struct sctp_cmd_seq *cmds,
871 struct sctp_association *asoc,
872 enum sctp_state state)
874 struct sock *sk = asoc->base.sk;
878 pr_debug("%s: asoc:%p[%s]\n", __func__, asoc, sctp_state_tbl[state]);
880 if (sctp_style(sk, TCP)) {
881 /* Change the sk->sk_state of a TCP-style socket that has
882 * successfully completed a connect() call.
884 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
885 inet_sk_set_state(sk, SCTP_SS_ESTABLISHED);
887 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
888 if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
889 sctp_sstate(sk, ESTABLISHED)) {
890 inet_sk_set_state(sk, SCTP_SS_CLOSING);
891 sk->sk_shutdown |= RCV_SHUTDOWN;
895 if (sctp_state(asoc, COOKIE_WAIT)) {
896 /* Reset init timeouts since they may have been
897 * increased due to timer expirations.
899 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
901 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
905 if (sctp_state(asoc, ESTABLISHED)) {
906 kfree(asoc->peer.cookie);
907 asoc->peer.cookie = NULL;
910 if (sctp_state(asoc, ESTABLISHED) ||
911 sctp_state(asoc, CLOSED) ||
912 sctp_state(asoc, SHUTDOWN_RECEIVED)) {
913 /* Wake up any processes waiting in the asoc's wait queue in
914 * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
916 if (waitqueue_active(&asoc->wait))
917 wake_up_interruptible(&asoc->wait);
919 /* Wake up any processes waiting in the sk's sleep queue of
920 * a TCP-style or UDP-style peeled-off socket in
921 * sctp_wait_for_accept() or sctp_wait_for_packet().
922 * For a UDP-style socket, the waiters are woken up by the
925 if (!sctp_style(sk, UDP))
926 sk->sk_state_change(sk);
929 if (sctp_state(asoc, SHUTDOWN_PENDING) &&
930 !sctp_outq_is_empty(&asoc->outqueue))
931 sctp_outq_uncork(&asoc->outqueue, GFP_ATOMIC);
934 /* Helper function to delete an association. */
935 static void sctp_cmd_delete_tcb(struct sctp_cmd_seq *cmds,
936 struct sctp_association *asoc)
938 struct sock *sk = asoc->base.sk;
940 /* If it is a non-temporary association belonging to a TCP-style
941 * listening socket that is not closed, do not free it so that accept()
942 * can pick it up later.
944 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
945 (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
948 sctp_association_free(asoc);
952 * ADDIP Section 4.1 ASCONF Chunk Procedures
953 * A4) Start a T-4 RTO timer, using the RTO value of the selected
954 * destination address (we use active path instead of primary path just
955 * because primary path may be inactive.
957 static void sctp_cmd_setup_t4(struct sctp_cmd_seq *cmds,
958 struct sctp_association *asoc,
959 struct sctp_chunk *chunk)
961 struct sctp_transport *t;
963 t = sctp_assoc_choose_alter_transport(asoc, chunk->transport);
964 asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
965 chunk->transport = t;
968 /* Process an incoming Operation Error Chunk. */
969 static void sctp_cmd_process_operr(struct sctp_cmd_seq *cmds,
970 struct sctp_association *asoc,
971 struct sctp_chunk *chunk)
973 struct sctp_errhdr *err_hdr;
974 struct sctp_ulpevent *ev;
976 while (chunk->chunk_end > chunk->skb->data) {
977 err_hdr = (struct sctp_errhdr *)(chunk->skb->data);
979 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
984 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
986 switch (err_hdr->cause) {
987 case SCTP_ERROR_UNKNOWN_CHUNK:
989 struct sctp_chunkhdr *unk_chunk_hdr;
991 unk_chunk_hdr = (struct sctp_chunkhdr *)
993 switch (unk_chunk_hdr->type) {
994 /* ADDIP 4.1 A9) If the peer responds to an ASCONF with
995 * an ERROR chunk reporting that it did not recognized
996 * the ASCONF chunk type, the sender of the ASCONF MUST
997 * NOT send any further ASCONF chunks and MUST stop its
1000 case SCTP_CID_ASCONF:
1001 if (asoc->peer.asconf_capable == 0)
1004 asoc->peer.asconf_capable = 0;
1005 sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
1006 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
1019 /* Helper function to remove the association non-primary peer
1022 static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
1024 struct sctp_transport *t;
1025 struct list_head *temp;
1026 struct list_head *pos;
1028 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
1029 t = list_entry(pos, struct sctp_transport, transports);
1030 if (!sctp_cmp_addr_exact(&t->ipaddr,
1031 &asoc->peer.primary_addr)) {
1032 sctp_assoc_rm_peer(asoc, t);
1037 /* Helper function to set sk_err on a 1-1 style socket. */
1038 static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
1040 struct sock *sk = asoc->base.sk;
1042 if (!sctp_style(sk, UDP))
1046 /* Helper function to generate an association change event */
1047 static void sctp_cmd_assoc_change(struct sctp_cmd_seq *commands,
1048 struct sctp_association *asoc,
1051 struct sctp_ulpevent *ev;
1053 ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0,
1054 asoc->c.sinit_num_ostreams,
1055 asoc->c.sinit_max_instreams,
1058 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
1061 static void sctp_cmd_peer_no_auth(struct sctp_cmd_seq *commands,
1062 struct sctp_association *asoc)
1064 struct sctp_ulpevent *ev;
1066 ev = sctp_ulpevent_make_authkey(asoc, 0, SCTP_AUTH_NO_AUTH, GFP_ATOMIC);
1068 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
1071 /* Helper function to generate an adaptation indication event */
1072 static void sctp_cmd_adaptation_ind(struct sctp_cmd_seq *commands,
1073 struct sctp_association *asoc)
1075 struct sctp_ulpevent *ev;
1077 ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
1080 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
1084 static void sctp_cmd_t1_timer_update(struct sctp_association *asoc,
1085 enum sctp_event_timeout timer,
1088 struct sctp_transport *t;
1090 t = asoc->init_last_sent_to;
1091 asoc->init_err_counter++;
1093 if (t->init_sent_count > (asoc->init_cycle + 1)) {
1094 asoc->timeouts[timer] *= 2;
1095 if (asoc->timeouts[timer] > asoc->max_init_timeo) {
1096 asoc->timeouts[timer] = asoc->max_init_timeo;
1100 pr_debug("%s: T1[%s] timeout adjustment init_err_counter:%d"
1101 " cycle:%d timeout:%ld\n", __func__, name,
1102 asoc->init_err_counter, asoc->init_cycle,
1103 asoc->timeouts[timer]);
1108 /* Send the whole message, chunk by chunk, to the outqueue.
1109 * This way the whole message is queued up and bundling if
1110 * encouraged for small fragments.
1112 static void sctp_cmd_send_msg(struct sctp_association *asoc,
1113 struct sctp_datamsg *msg, gfp_t gfp)
1115 struct sctp_chunk *chunk;
1117 list_for_each_entry(chunk, &msg->chunks, frag_list)
1118 sctp_outq_tail(&asoc->outqueue, chunk, gfp);
1120 asoc->outqueue.sched->enqueue(&asoc->outqueue, msg);
1124 /* These three macros allow us to pull the debugging code out of the
1125 * main flow of sctp_do_sm() to keep attention focused on the real
1126 * functionality there.
1128 #define debug_pre_sfn() \
1129 pr_debug("%s[pre-fn]: ep:%p, %s, %s, asoc:%p[%s], %s\n", __func__, \
1130 ep, sctp_evttype_tbl[event_type], (*debug_fn)(subtype), \
1131 asoc, sctp_state_tbl[state], state_fn->name)
1133 #define debug_post_sfn() \
1134 pr_debug("%s[post-fn]: asoc:%p, status:%s\n", __func__, asoc, \
1135 sctp_status_tbl[status])
1137 #define debug_post_sfx() \
1138 pr_debug("%s[post-sfx]: error:%d, asoc:%p[%s]\n", __func__, error, \
1139 asoc, sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
1140 sctp_assoc2id(asoc))) ? asoc->state : SCTP_STATE_CLOSED])
1143 * This is the master state machine processing function.
1145 * If you want to understand all of lksctp, this is a
1146 * good place to start.
1148 int sctp_do_sm(struct net *net, enum sctp_event event_type,
1149 union sctp_subtype subtype, enum sctp_state state,
1150 struct sctp_endpoint *ep, struct sctp_association *asoc,
1151 void *event_arg, gfp_t gfp)
1153 typedef const char *(printfn_t)(union sctp_subtype);
1154 static printfn_t *table[] = {
1155 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
1157 printfn_t *debug_fn __attribute__ ((unused)) = table[event_type];
1158 const struct sctp_sm_table_entry *state_fn;
1159 struct sctp_cmd_seq commands;
1160 enum sctp_disposition status;
1163 /* Look up the state function, run it, and then process the
1164 * side effects. These three steps are the heart of lksctp.
1166 state_fn = sctp_sm_lookup_event(net, event_type, state, subtype);
1168 sctp_init_cmd_seq(&commands);
1171 status = state_fn->fn(net, ep, asoc, subtype, event_arg, &commands);
1174 error = sctp_side_effects(event_type, subtype, state,
1175 ep, &asoc, event_arg, status,
1182 /*****************************************************************
1183 * This the master state function side effect processing function.
1184 *****************************************************************/
1185 static int sctp_side_effects(enum sctp_event event_type,
1186 union sctp_subtype subtype,
1187 enum sctp_state state,
1188 struct sctp_endpoint *ep,
1189 struct sctp_association **asoc,
1191 enum sctp_disposition status,
1192 struct sctp_cmd_seq *commands,
1197 /* FIXME - Most of the dispositions left today would be categorized
1198 * as "exceptional" dispositions. For those dispositions, it
1199 * may not be proper to run through any of the commands at all.
1200 * For example, the command interpreter might be run only with
1201 * disposition SCTP_DISPOSITION_CONSUME.
1203 if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
1210 case SCTP_DISPOSITION_DISCARD:
1211 pr_debug("%s: ignored sctp protocol event - state:%d, "
1212 "event_type:%d, event_id:%d\n", __func__, state,
1213 event_type, subtype.chunk);
1216 case SCTP_DISPOSITION_NOMEM:
1217 /* We ran out of memory, so we need to discard this
1220 /* BUG--we should now recover some memory, probably by
1226 case SCTP_DISPOSITION_DELETE_TCB:
1227 case SCTP_DISPOSITION_ABORT:
1228 /* This should now be a command. */
1232 case SCTP_DISPOSITION_CONSUME:
1234 * We should no longer have much work to do here as the
1235 * real work has been done as explicit commands above.
1239 case SCTP_DISPOSITION_VIOLATION:
1240 net_err_ratelimited("protocol violation state %d chunkid %d\n",
1241 state, subtype.chunk);
1244 case SCTP_DISPOSITION_NOT_IMPL:
1245 pr_warn("unimplemented feature in state %d, event_type %d, event_id %d\n",
1246 state, event_type, subtype.chunk);
1249 case SCTP_DISPOSITION_BUG:
1250 pr_err("bug in state %d, event_type %d, event_id %d\n",
1251 state, event_type, subtype.chunk);
1256 pr_err("impossible disposition %d in state %d, event_type %d, event_id %d\n",
1257 status, state, event_type, subtype.chunk);
1266 /********************************************************************
1267 * 2nd Level Abstractions
1268 ********************************************************************/
1270 /* This is the side-effect interpreter. */
1271 static int sctp_cmd_interpreter(enum sctp_event event_type,
1272 union sctp_subtype subtype,
1273 enum sctp_state state,
1274 struct sctp_endpoint *ep,
1275 struct sctp_association *asoc,
1277 enum sctp_disposition status,
1278 struct sctp_cmd_seq *commands,
1281 struct sctp_sock *sp = sctp_sk(ep->base.sk);
1282 struct sctp_chunk *chunk = NULL, *new_obj;
1283 struct sctp_packet *packet;
1284 struct sctp_sackhdr sackh;
1285 struct timer_list *timer;
1286 struct sctp_transport *t;
1287 unsigned long timeout;
1288 struct sctp_cmd *cmd;
1293 if (SCTP_EVENT_T_TIMEOUT != event_type)
1296 /* Note: This whole file is a huge candidate for rework.
1297 * For example, each command could either have its own handler, so
1298 * the loop would look like:
1300 * cmd->handle(x, y, z)
1303 while (NULL != (cmd = sctp_next_cmd(commands))) {
1304 switch (cmd->verb) {
1309 case SCTP_CMD_NEW_ASOC:
1310 /* Register a new association. */
1312 sctp_outq_uncork(&asoc->outqueue, gfp);
1316 /* Register with the endpoint. */
1317 asoc = cmd->obj.asoc;
1318 BUG_ON(asoc->peer.primary_path == NULL);
1319 sctp_endpoint_add_asoc(ep, asoc);
1322 case SCTP_CMD_UPDATE_ASSOC:
1323 sctp_cmd_assoc_update(commands, asoc, cmd->obj.asoc);
1326 case SCTP_CMD_PURGE_OUTQUEUE:
1327 sctp_outq_teardown(&asoc->outqueue);
1330 case SCTP_CMD_DELETE_TCB:
1332 sctp_outq_uncork(&asoc->outqueue, gfp);
1335 /* Delete the current association. */
1336 sctp_cmd_delete_tcb(commands, asoc);
1340 case SCTP_CMD_NEW_STATE:
1341 /* Enter a new state. */
1342 sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1345 case SCTP_CMD_REPORT_TSN:
1346 /* Record the arrival of a TSN. */
1347 error = sctp_tsnmap_mark(&asoc->peer.tsn_map,
1348 cmd->obj.u32, NULL);
1351 case SCTP_CMD_REPORT_FWDTSN:
1352 asoc->stream.si->report_ftsn(&asoc->ulpq, cmd->obj.u32);
1355 case SCTP_CMD_PROCESS_FWDTSN:
1356 asoc->stream.si->handle_ftsn(&asoc->ulpq,
1360 case SCTP_CMD_GEN_SACK:
1361 /* Generate a Selective ACK.
1362 * The argument tells us whether to just count
1363 * the packet and MAYBE generate a SACK, or
1366 force = cmd->obj.i32;
1367 error = sctp_gen_sack(asoc, force, commands);
1370 case SCTP_CMD_PROCESS_SACK:
1371 /* Process an inbound SACK. */
1372 error = sctp_cmd_process_sack(commands, asoc,
1376 case SCTP_CMD_GEN_INIT_ACK:
1377 /* Generate an INIT ACK chunk. */
1378 new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1385 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1386 SCTP_CHUNK(new_obj));
1389 case SCTP_CMD_PEER_INIT:
1390 /* Process a unified INIT from the peer.
1391 * Note: Only used during INIT-ACK processing. If
1392 * there is an error just return to the outter
1393 * layer which will bail.
1395 error = sctp_cmd_process_init(commands, asoc, chunk,
1396 cmd->obj.init, gfp);
1399 case SCTP_CMD_GEN_COOKIE_ECHO:
1400 /* Generate a COOKIE ECHO chunk. */
1401 new_obj = sctp_make_cookie_echo(asoc, chunk);
1404 sctp_chunk_free(cmd->obj.chunk);
1408 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1409 SCTP_CHUNK(new_obj));
1411 /* If there is an ERROR chunk to be sent along with
1412 * the COOKIE_ECHO, send it, too.
1415 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1416 SCTP_CHUNK(cmd->obj.chunk));
1418 if (new_obj->transport) {
1419 new_obj->transport->init_sent_count++;
1420 asoc->init_last_sent_to = new_obj->transport;
1423 /* FIXME - Eventually come up with a cleaner way to
1424 * enabling COOKIE-ECHO + DATA bundling during
1425 * multihoming stale cookie scenarios, the following
1426 * command plays with asoc->peer.retran_path to
1427 * avoid the problem of sending the COOKIE-ECHO and
1428 * DATA in different paths, which could result
1429 * in the association being ABORTed if the DATA chunk
1430 * is processed first by the server. Checking the
1431 * init error counter simply causes this command
1432 * to be executed only during failed attempts of
1433 * association establishment.
1435 if ((asoc->peer.retran_path !=
1436 asoc->peer.primary_path) &&
1437 (asoc->init_err_counter > 0)) {
1438 sctp_add_cmd_sf(commands,
1439 SCTP_CMD_FORCE_PRIM_RETRAN,
1445 case SCTP_CMD_GEN_SHUTDOWN:
1446 /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1447 * Reset error counts.
1449 asoc->overall_error_count = 0;
1451 /* Generate a SHUTDOWN chunk. */
1452 new_obj = sctp_make_shutdown(asoc, chunk);
1457 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1458 SCTP_CHUNK(new_obj));
1461 case SCTP_CMD_CHUNK_ULP:
1462 /* Send a chunk to the sockets layer. */
1463 pr_debug("%s: sm_sideff: chunk_up:%p, ulpq:%p\n",
1464 __func__, cmd->obj.chunk, &asoc->ulpq);
1466 asoc->stream.si->ulpevent_data(&asoc->ulpq,
1471 case SCTP_CMD_EVENT_ULP:
1472 /* Send a notification to the sockets layer. */
1473 pr_debug("%s: sm_sideff: event_up:%p, ulpq:%p\n",
1474 __func__, cmd->obj.ulpevent, &asoc->ulpq);
1476 asoc->stream.si->enqueue_event(&asoc->ulpq,
1480 case SCTP_CMD_REPLY:
1481 /* If an caller has not already corked, do cork. */
1482 if (!asoc->outqueue.cork) {
1483 sctp_outq_cork(&asoc->outqueue);
1486 /* Send a chunk to our peer. */
1487 sctp_outq_tail(&asoc->outqueue, cmd->obj.chunk, gfp);
1490 case SCTP_CMD_SEND_PKT:
1491 /* Send a full packet to our peer. */
1492 packet = cmd->obj.packet;
1493 sctp_packet_transmit(packet, gfp);
1494 sctp_ootb_pkt_free(packet);
1497 case SCTP_CMD_T1_RETRAN:
1498 /* Mark a transport for retransmission. */
1499 sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1503 case SCTP_CMD_RETRAN:
1504 /* Mark a transport for retransmission. */
1505 sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1509 case SCTP_CMD_ECN_CE:
1510 /* Do delayed CE processing. */
1511 sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1514 case SCTP_CMD_ECN_ECNE:
1515 /* Do delayed ECNE processing. */
1516 new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1519 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1520 SCTP_CHUNK(new_obj));
1523 case SCTP_CMD_ECN_CWR:
1524 /* Do delayed CWR processing. */
1525 sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1528 case SCTP_CMD_SETUP_T2:
1529 sctp_cmd_setup_t2(commands, asoc, cmd->obj.chunk);
1532 case SCTP_CMD_TIMER_START_ONCE:
1533 timer = &asoc->timers[cmd->obj.to];
1535 if (timer_pending(timer))
1539 case SCTP_CMD_TIMER_START:
1540 timer = &asoc->timers[cmd->obj.to];
1541 timeout = asoc->timeouts[cmd->obj.to];
1545 * SCTP has a hard time with timer starts. Because we process
1546 * timer starts as side effects, it can be hard to tell if we
1547 * have already started a timer or not, which leads to BUG
1548 * halts when we call add_timer. So here, instead of just starting
1549 * a timer, if the timer is already started, and just mod
1550 * the timer with the shorter of the two expiration times
1552 if (!timer_pending(timer))
1553 sctp_association_hold(asoc);
1554 timer_reduce(timer, jiffies + timeout);
1557 case SCTP_CMD_TIMER_RESTART:
1558 timer = &asoc->timers[cmd->obj.to];
1559 timeout = asoc->timeouts[cmd->obj.to];
1560 if (!mod_timer(timer, jiffies + timeout))
1561 sctp_association_hold(asoc);
1564 case SCTP_CMD_TIMER_STOP:
1565 timer = &asoc->timers[cmd->obj.to];
1566 if (del_timer(timer))
1567 sctp_association_put(asoc);
1570 case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1571 chunk = cmd->obj.chunk;
1572 t = sctp_assoc_choose_alter_transport(asoc,
1573 asoc->init_last_sent_to);
1574 asoc->init_last_sent_to = t;
1575 chunk->transport = t;
1576 t->init_sent_count++;
1577 /* Set the new transport as primary */
1578 sctp_assoc_set_primary(asoc, t);
1581 case SCTP_CMD_INIT_RESTART:
1582 /* Do the needed accounting and updates
1583 * associated with restarting an initialization
1584 * timer. Only multiply the timeout by two if
1585 * all transports have been tried at the current
1588 sctp_cmd_t1_timer_update(asoc,
1589 SCTP_EVENT_TIMEOUT_T1_INIT,
1592 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1593 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1596 case SCTP_CMD_COOKIEECHO_RESTART:
1597 /* Do the needed accounting and updates
1598 * associated with restarting an initialization
1599 * timer. Only multiply the timeout by two if
1600 * all transports have been tried at the current
1603 sctp_cmd_t1_timer_update(asoc,
1604 SCTP_EVENT_TIMEOUT_T1_COOKIE,
1607 /* If we've sent any data bundled with
1608 * COOKIE-ECHO we need to resend.
1610 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1612 sctp_retransmit_mark(&asoc->outqueue, t,
1616 sctp_add_cmd_sf(commands,
1617 SCTP_CMD_TIMER_RESTART,
1618 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1621 case SCTP_CMD_INIT_FAILED:
1622 sctp_cmd_init_failed(commands, asoc, cmd->obj.u16);
1625 case SCTP_CMD_ASSOC_FAILED:
1626 sctp_cmd_assoc_failed(commands, asoc, event_type,
1627 subtype, chunk, cmd->obj.u16);
1630 case SCTP_CMD_INIT_COUNTER_INC:
1631 asoc->init_err_counter++;
1634 case SCTP_CMD_INIT_COUNTER_RESET:
1635 asoc->init_err_counter = 0;
1636 asoc->init_cycle = 0;
1637 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1639 t->init_sent_count = 0;
1643 case SCTP_CMD_REPORT_DUP:
1644 sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1648 case SCTP_CMD_REPORT_BAD_TAG:
1649 pr_debug("%s: vtag mismatch!\n", __func__);
1652 case SCTP_CMD_STRIKE:
1653 /* Mark one strike against a transport. */
1654 sctp_do_8_2_transport_strike(commands, asoc,
1655 cmd->obj.transport, 0);
1658 case SCTP_CMD_TRANSPORT_IDLE:
1659 t = cmd->obj.transport;
1660 sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
1663 case SCTP_CMD_TRANSPORT_HB_SENT:
1664 t = cmd->obj.transport;
1665 sctp_do_8_2_transport_strike(commands, asoc,
1670 case SCTP_CMD_TRANSPORT_ON:
1671 t = cmd->obj.transport;
1672 sctp_cmd_transport_on(commands, asoc, t, chunk);
1675 case SCTP_CMD_HB_TIMERS_START:
1676 sctp_cmd_hb_timers_start(commands, asoc);
1679 case SCTP_CMD_HB_TIMER_UPDATE:
1680 t = cmd->obj.transport;
1681 sctp_transport_reset_hb_timer(t);
1684 case SCTP_CMD_HB_TIMERS_STOP:
1685 sctp_cmd_hb_timers_stop(commands, asoc);
1688 case SCTP_CMD_REPORT_ERROR:
1689 error = cmd->obj.error;
1692 case SCTP_CMD_PROCESS_CTSN:
1693 /* Dummy up a SACK for processing. */
1694 sackh.cum_tsn_ack = cmd->obj.be32;
1695 sackh.a_rwnd = htonl(asoc->peer.rwnd +
1696 asoc->outqueue.outstanding_bytes);
1697 sackh.num_gap_ack_blocks = 0;
1698 sackh.num_dup_tsns = 0;
1699 chunk->subh.sack_hdr = &sackh;
1700 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1704 case SCTP_CMD_DISCARD_PACKET:
1705 /* We need to discard the whole packet.
1706 * Uncork the queue since there might be
1709 chunk->pdiscard = 1;
1711 sctp_outq_uncork(&asoc->outqueue, gfp);
1716 case SCTP_CMD_RTO_PENDING:
1717 t = cmd->obj.transport;
1721 case SCTP_CMD_PART_DELIVER:
1722 asoc->stream.si->start_pd(&asoc->ulpq, GFP_ATOMIC);
1725 case SCTP_CMD_RENEGE:
1726 asoc->stream.si->renege_events(&asoc->ulpq,
1731 case SCTP_CMD_SETUP_T4:
1732 sctp_cmd_setup_t4(commands, asoc, cmd->obj.chunk);
1735 case SCTP_CMD_PROCESS_OPERR:
1736 sctp_cmd_process_operr(commands, asoc, chunk);
1738 case SCTP_CMD_CLEAR_INIT_TAG:
1739 asoc->peer.i.init_tag = 0;
1741 case SCTP_CMD_DEL_NON_PRIMARY:
1742 sctp_cmd_del_non_primary(asoc);
1744 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1745 sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1747 case SCTP_CMD_FORCE_PRIM_RETRAN:
1748 t = asoc->peer.retran_path;
1749 asoc->peer.retran_path = asoc->peer.primary_path;
1750 sctp_outq_uncork(&asoc->outqueue, gfp);
1752 asoc->peer.retran_path = t;
1754 case SCTP_CMD_SET_SK_ERR:
1755 sctp_cmd_set_sk_err(asoc, cmd->obj.error);
1757 case SCTP_CMD_ASSOC_CHANGE:
1758 sctp_cmd_assoc_change(commands, asoc,
1761 case SCTP_CMD_ADAPTATION_IND:
1762 sctp_cmd_adaptation_ind(commands, asoc);
1764 case SCTP_CMD_PEER_NO_AUTH:
1765 sctp_cmd_peer_no_auth(commands, asoc);
1768 case SCTP_CMD_ASSOC_SHKEY:
1769 error = sctp_auth_asoc_init_active_key(asoc,
1772 case SCTP_CMD_UPDATE_INITTAG:
1773 asoc->peer.i.init_tag = cmd->obj.u32;
1775 case SCTP_CMD_SEND_MSG:
1776 if (!asoc->outqueue.cork) {
1777 sctp_outq_cork(&asoc->outqueue);
1780 sctp_cmd_send_msg(asoc, cmd->obj.msg, gfp);
1782 case SCTP_CMD_PURGE_ASCONF_QUEUE:
1783 sctp_asconf_queue_teardown(asoc);
1786 case SCTP_CMD_SET_ASOC:
1787 if (asoc && local_cork) {
1788 sctp_outq_uncork(&asoc->outqueue, gfp);
1791 asoc = cmd->obj.asoc;
1795 pr_warn("Impossible command: %u\n",
1801 cmd = sctp_next_cmd(commands);
1803 if (cmd->verb == SCTP_CMD_REPLY)
1804 sctp_chunk_free(cmd->obj.chunk);
1805 cmd = sctp_next_cmd(commands);
1811 /* If this is in response to a received chunk, wait until
1812 * we are done with the packet to open the queue so that we don't
1813 * send multiple packets in response to a single request.
1815 if (asoc && SCTP_EVENT_T_CHUNK == event_type && chunk) {
1816 if (chunk->end_of_packet || chunk->singleton)
1817 sctp_outq_uncork(&asoc->outqueue, gfp);
1818 } else if (local_cork)
1819 sctp_outq_uncork(&asoc->outqueue, gfp);
1821 if (sp->data_ready_signalled)
1822 sp->data_ready_signalled = 0;