1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* SCTP kernel implementation
3 * (C) Copyright IBM Corp. 2001, 2004
4 * Copyright (c) 1999 Cisco, Inc.
5 * Copyright (c) 1999-2001 Motorola, Inc.
6 *
7 * This file is part of the SCTP kernel implementation
8 *
9 * These functions work with the state functions in sctp_sm_statefuns.c
10 * to implement that state operations. These functions implement the
11 * steps which require modifying existing data structures.
12 *
13 * Please send any bug reports or fixes you make to the
14 * email address(es):
15 * lksctp developers <linux-sctp@vger.kernel.org>
16 *
17 * Written or modified by:
18 * La Monte H.P. Yarroll <piggy@acm.org>
19 * Karl Knutson <karl@athena.chicago.il.us>
20 * Jon Grimm <jgrimm@austin.ibm.com>
21 * Hui Huang <hui.huang@nokia.com>
22 * Dajiang Zhang <dajiang.zhang@nokia.com>
23 * Daisy Chang <daisyc@us.ibm.com>
24 * Sridhar Samudrala <sri@us.ibm.com>
25 * Ardelle Fan <ardelle.fan@intel.com>
26 */
27
28 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
29
30 #include <linux/skbuff.h>
31 #include <linux/types.h>
32 #include <linux/socket.h>
33 #include <linux/ip.h>
34 #include <linux/gfp.h>
35 #include <net/sock.h>
36 #include <net/sctp/sctp.h>
37 #include <net/sctp/sm.h>
38 #include <net/sctp/stream_sched.h>
39
40 static int sctp_cmd_interpreter(enum sctp_event_type event_type,
41 union sctp_subtype subtype,
42 enum sctp_state state,
43 struct sctp_endpoint *ep,
44 struct sctp_association *asoc,
45 void *event_arg,
46 enum sctp_disposition status,
47 struct sctp_cmd_seq *commands,
48 gfp_t gfp);
49 static int sctp_side_effects(enum sctp_event_type event_type,
50 union sctp_subtype subtype,
51 enum sctp_state state,
52 struct sctp_endpoint *ep,
53 struct sctp_association **asoc,
54 void *event_arg,
55 enum sctp_disposition status,
56 struct sctp_cmd_seq *commands,
57 gfp_t gfp);
58
59 /********************************************************************
60 * Helper functions
61 ********************************************************************/
62
63 /* A helper function for delayed processing of INET ECN CE bit. */
sctp_do_ecn_ce_work(struct sctp_association * asoc,__u32 lowest_tsn)64 static void sctp_do_ecn_ce_work(struct sctp_association *asoc,
65 __u32 lowest_tsn)
66 {
67 /* Save the TSN away for comparison when we receive CWR */
68
69 asoc->last_ecne_tsn = lowest_tsn;
70 asoc->need_ecne = 1;
71 }
72
73 /* Helper function for delayed processing of SCTP ECNE chunk. */
74 /* RFC 2960 Appendix A
75 *
76 * RFC 2481 details a specific bit for a sender to send in
77 * the header of its next outbound TCP segment to indicate to
78 * its peer that it has reduced its congestion window. This
79 * is termed the CWR bit. For SCTP the same indication is made
80 * by including the CWR chunk. This chunk contains one data
81 * element, i.e. the TSN number that was sent in the ECNE chunk.
82 * This element represents the lowest TSN number in the datagram
83 * that was originally marked with the CE bit.
84 */
sctp_do_ecn_ecne_work(struct sctp_association * asoc,__u32 lowest_tsn,struct sctp_chunk * chunk)85 static struct sctp_chunk *sctp_do_ecn_ecne_work(struct sctp_association *asoc,
86 __u32 lowest_tsn,
87 struct sctp_chunk *chunk)
88 {
89 struct sctp_chunk *repl;
90
91 /* Our previously transmitted packet ran into some congestion
92 * so we should take action by reducing cwnd and ssthresh
93 * and then ACK our peer that we we've done so by
94 * sending a CWR.
95 */
96
97 /* First, try to determine if we want to actually lower
98 * our cwnd variables. Only lower them if the ECNE looks more
99 * recent than the last response.
100 */
101 if (TSN_lt(asoc->last_cwr_tsn, lowest_tsn)) {
102 struct sctp_transport *transport;
103
104 /* Find which transport's congestion variables
105 * need to be adjusted.
106 */
107 transport = sctp_assoc_lookup_tsn(asoc, lowest_tsn);
108
109 /* Update the congestion variables. */
110 if (transport)
111 sctp_transport_lower_cwnd(transport,
112 SCTP_LOWER_CWND_ECNE);
113 asoc->last_cwr_tsn = lowest_tsn;
114 }
115
116 /* Always try to quiet the other end. In case of lost CWR,
117 * resend last_cwr_tsn.
118 */
119 repl = sctp_make_cwr(asoc, asoc->last_cwr_tsn, chunk);
120
121 /* If we run out of memory, it will look like a lost CWR. We'll
122 * get back in sync eventually.
123 */
124 return repl;
125 }
126
127 /* Helper function to do delayed processing of ECN CWR chunk. */
sctp_do_ecn_cwr_work(struct sctp_association * asoc,__u32 lowest_tsn)128 static void sctp_do_ecn_cwr_work(struct sctp_association *asoc,
129 __u32 lowest_tsn)
130 {
131 /* Turn off ECNE getting auto-prepended to every outgoing
132 * packet
133 */
134 asoc->need_ecne = 0;
135 }
136
137 /* Generate SACK if necessary. We call this at the end of a packet. */
sctp_gen_sack(struct sctp_association * asoc,int force,struct sctp_cmd_seq * commands)138 static int sctp_gen_sack(struct sctp_association *asoc, int force,
139 struct sctp_cmd_seq *commands)
140 {
141 struct sctp_transport *trans = asoc->peer.last_data_from;
142 __u32 ctsn, max_tsn_seen;
143 struct sctp_chunk *sack;
144 int error = 0;
145
146 if (force ||
147 (!trans && (asoc->param_flags & SPP_SACKDELAY_DISABLE)) ||
148 (trans && (trans->param_flags & SPP_SACKDELAY_DISABLE)))
149 asoc->peer.sack_needed = 1;
150
151 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
152 max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
153
154 /* From 12.2 Parameters necessary per association (i.e. the TCB):
155 *
156 * Ack State : This flag indicates if the next received packet
157 * : is to be responded to with a SACK. ...
158 * : When DATA chunks are out of order, SACK's
159 * : are not delayed (see Section 6).
160 *
161 * [This is actually not mentioned in Section 6, but we
162 * implement it here anyway. --piggy]
163 */
164 if (max_tsn_seen != ctsn)
165 asoc->peer.sack_needed = 1;
166
167 /* From 6.2 Acknowledgement on Reception of DATA Chunks:
168 *
169 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically,
170 * an acknowledgement SHOULD be generated for at least every
171 * second packet (not every second DATA chunk) received, and
172 * SHOULD be generated within 200 ms of the arrival of any
173 * unacknowledged DATA chunk. ...
174 */
175 if (!asoc->peer.sack_needed) {
176 asoc->peer.sack_cnt++;
177
178 /* Set the SACK delay timeout based on the
179 * SACK delay for the last transport
180 * data was received from, or the default
181 * for the association.
182 */
183 if (trans) {
184 /* We will need a SACK for the next packet. */
185 if (asoc->peer.sack_cnt >= trans->sackfreq - 1)
186 asoc->peer.sack_needed = 1;
187
188 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
189 trans->sackdelay;
190 } else {
191 /* We will need a SACK for the next packet. */
192 if (asoc->peer.sack_cnt >= asoc->sackfreq - 1)
193 asoc->peer.sack_needed = 1;
194
195 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
196 asoc->sackdelay;
197 }
198
199 /* Restart the SACK timer. */
200 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
201 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
202 } else {
203 __u32 old_a_rwnd = asoc->a_rwnd;
204
205 asoc->a_rwnd = asoc->rwnd;
206 sack = sctp_make_sack(asoc);
207 if (!sack) {
208 asoc->a_rwnd = old_a_rwnd;
209 goto nomem;
210 }
211
212 asoc->peer.sack_needed = 0;
213 asoc->peer.sack_cnt = 0;
214
215 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(sack));
216
217 /* Stop the SACK timer. */
218 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
219 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
220 }
221
222 return error;
223 nomem:
224 error = -ENOMEM;
225 return error;
226 }
227
228 /* When the T3-RTX timer expires, it calls this function to create the
229 * relevant state machine event.
230 */
sctp_generate_t3_rtx_event(struct timer_list * t)231 void sctp_generate_t3_rtx_event(struct timer_list *t)
232 {
233 struct sctp_transport *transport =
234 from_timer(transport, t, T3_rtx_timer);
235 struct sctp_association *asoc = transport->asoc;
236 struct sock *sk = asoc->base.sk;
237 struct net *net = sock_net(sk);
238 int error;
239
240 /* Check whether a task is in the sock. */
241
242 bh_lock_sock(sk);
243 if (sock_owned_by_user(sk)) {
244 pr_debug("%s: sock is busy\n", __func__);
245
246 /* Try again later. */
247 if (!mod_timer(&transport->T3_rtx_timer, jiffies + (HZ/20)))
248 sctp_transport_hold(transport);
249 goto out_unlock;
250 }
251
252 /* Run through the state machine. */
253 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
254 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX),
255 asoc->state,
256 asoc->ep, asoc,
257 transport, GFP_ATOMIC);
258
259 if (error)
260 sk->sk_err = -error;
261
262 out_unlock:
263 bh_unlock_sock(sk);
264 sctp_transport_put(transport);
265 }
266
267 /* This is a sa interface for producing timeout events. It works
268 * for timeouts which use the association as their parameter.
269 */
sctp_generate_timeout_event(struct sctp_association * asoc,enum sctp_event_timeout timeout_type)270 static void sctp_generate_timeout_event(struct sctp_association *asoc,
271 enum sctp_event_timeout timeout_type)
272 {
273 struct sock *sk = asoc->base.sk;
274 struct net *net = sock_net(sk);
275 int error = 0;
276
277 bh_lock_sock(sk);
278 if (sock_owned_by_user(sk)) {
279 pr_debug("%s: sock is busy: timer %d\n", __func__,
280 timeout_type);
281
282 /* Try again later. */
283 if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20)))
284 sctp_association_hold(asoc);
285 goto out_unlock;
286 }
287
288 /* Is this association really dead and just waiting around for
289 * the timer to let go of the reference?
290 */
291 if (asoc->base.dead)
292 goto out_unlock;
293
294 /* Run through the state machine. */
295 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
296 SCTP_ST_TIMEOUT(timeout_type),
297 asoc->state, asoc->ep, asoc,
298 (void *)timeout_type, GFP_ATOMIC);
299
300 if (error)
301 sk->sk_err = -error;
302
303 out_unlock:
304 bh_unlock_sock(sk);
305 sctp_association_put(asoc);
306 }
307
sctp_generate_t1_cookie_event(struct timer_list * t)308 static void sctp_generate_t1_cookie_event(struct timer_list *t)
309 {
310 struct sctp_association *asoc =
311 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_T1_COOKIE]);
312
313 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
314 }
315
sctp_generate_t1_init_event(struct timer_list * t)316 static void sctp_generate_t1_init_event(struct timer_list *t)
317 {
318 struct sctp_association *asoc =
319 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_T1_INIT]);
320
321 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
322 }
323
sctp_generate_t2_shutdown_event(struct timer_list * t)324 static void sctp_generate_t2_shutdown_event(struct timer_list *t)
325 {
326 struct sctp_association *asoc =
327 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN]);
328
329 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
330 }
331
sctp_generate_t4_rto_event(struct timer_list * t)332 static void sctp_generate_t4_rto_event(struct timer_list *t)
333 {
334 struct sctp_association *asoc =
335 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_T4_RTO]);
336
337 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
338 }
339
sctp_generate_t5_shutdown_guard_event(struct timer_list * t)340 static void sctp_generate_t5_shutdown_guard_event(struct timer_list *t)
341 {
342 struct sctp_association *asoc =
343 from_timer(asoc, t,
344 timers[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD]);
345
346 sctp_generate_timeout_event(asoc,
347 SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);
348
349 } /* sctp_generate_t5_shutdown_guard_event() */
350
sctp_generate_autoclose_event(struct timer_list * t)351 static void sctp_generate_autoclose_event(struct timer_list *t)
352 {
353 struct sctp_association *asoc =
354 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_AUTOCLOSE]);
355
356 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE);
357 }
358
359 /* Generate a heart beat event. If the sock is busy, reschedule. Make
360 * sure that the transport is still valid.
361 */
sctp_generate_heartbeat_event(struct timer_list * t)362 void sctp_generate_heartbeat_event(struct timer_list *t)
363 {
364 struct sctp_transport *transport = from_timer(transport, t, hb_timer);
365 struct sctp_association *asoc = transport->asoc;
366 struct sock *sk = asoc->base.sk;
367 struct net *net = sock_net(sk);
368 u32 elapsed, timeout;
369 int error = 0;
370
371 bh_lock_sock(sk);
372 if (sock_owned_by_user(sk)) {
373 pr_debug("%s: sock is busy\n", __func__);
374
375 /* Try again later. */
376 if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20)))
377 sctp_transport_hold(transport);
378 goto out_unlock;
379 }
380
381 /* Check if we should still send the heartbeat or reschedule */
382 elapsed = jiffies - transport->last_time_sent;
383 timeout = sctp_transport_timeout(transport);
384 if (elapsed < timeout) {
385 elapsed = timeout - elapsed;
386 if (!mod_timer(&transport->hb_timer, jiffies + elapsed))
387 sctp_transport_hold(transport);
388 goto out_unlock;
389 }
390
391 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
392 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
393 asoc->state, asoc->ep, asoc,
394 transport, GFP_ATOMIC);
395
396 if (error)
397 sk->sk_err = -error;
398
399 out_unlock:
400 bh_unlock_sock(sk);
401 sctp_transport_put(transport);
402 }
403
404 /* Handle the timeout of the ICMP protocol unreachable timer. Trigger
405 * the correct state machine transition that will close the association.
406 */
sctp_generate_proto_unreach_event(struct timer_list * t)407 void sctp_generate_proto_unreach_event(struct timer_list *t)
408 {
409 struct sctp_transport *transport =
410 from_timer(transport, t, proto_unreach_timer);
411 struct sctp_association *asoc = transport->asoc;
412 struct sock *sk = asoc->base.sk;
413 struct net *net = sock_net(sk);
414
415 bh_lock_sock(sk);
416 if (sock_owned_by_user(sk)) {
417 pr_debug("%s: sock is busy\n", __func__);
418
419 /* Try again later. */
420 if (!mod_timer(&transport->proto_unreach_timer,
421 jiffies + (HZ/20)))
422 sctp_transport_hold(transport);
423 goto out_unlock;
424 }
425
426 /* Is this structure just waiting around for us to actually
427 * get destroyed?
428 */
429 if (asoc->base.dead)
430 goto out_unlock;
431
432 sctp_do_sm(net, SCTP_EVENT_T_OTHER,
433 SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH),
434 asoc->state, asoc->ep, asoc, transport, GFP_ATOMIC);
435
436 out_unlock:
437 bh_unlock_sock(sk);
438 sctp_transport_put(transport);
439 }
440
441 /* Handle the timeout of the RE-CONFIG timer. */
sctp_generate_reconf_event(struct timer_list * t)442 void sctp_generate_reconf_event(struct timer_list *t)
443 {
444 struct sctp_transport *transport =
445 from_timer(transport, t, reconf_timer);
446 struct sctp_association *asoc = transport->asoc;
447 struct sock *sk = asoc->base.sk;
448 struct net *net = sock_net(sk);
449 int error = 0;
450
451 bh_lock_sock(sk);
452 if (sock_owned_by_user(sk)) {
453 pr_debug("%s: sock is busy\n", __func__);
454
455 /* Try again later. */
456 if (!mod_timer(&transport->reconf_timer, jiffies + (HZ / 20)))
457 sctp_transport_hold(transport);
458 goto out_unlock;
459 }
460
461 /* This happens when the response arrives after the timer is triggered. */
462 if (!asoc->strreset_chunk)
463 goto out_unlock;
464
465 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
466 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_RECONF),
467 asoc->state, asoc->ep, asoc,
468 transport, GFP_ATOMIC);
469
470 if (error)
471 sk->sk_err = -error;
472
473 out_unlock:
474 bh_unlock_sock(sk);
475 sctp_transport_put(transport);
476 }
477
478 /* Handle the timeout of the probe timer. */
sctp_generate_probe_event(struct timer_list * t)479 void sctp_generate_probe_event(struct timer_list *t)
480 {
481 struct sctp_transport *transport = from_timer(transport, t, probe_timer);
482 struct sctp_association *asoc = transport->asoc;
483 struct sock *sk = asoc->base.sk;
484 struct net *net = sock_net(sk);
485 int error = 0;
486
487 bh_lock_sock(sk);
488 if (sock_owned_by_user(sk)) {
489 pr_debug("%s: sock is busy\n", __func__);
490
491 /* Try again later. */
492 if (!mod_timer(&transport->probe_timer, jiffies + (HZ / 20)))
493 sctp_transport_hold(transport);
494 goto out_unlock;
495 }
496
497 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
498 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_PROBE),
499 asoc->state, asoc->ep, asoc,
500 transport, GFP_ATOMIC);
501
502 if (error)
503 sk->sk_err = -error;
504
505 out_unlock:
506 bh_unlock_sock(sk);
507 sctp_transport_put(transport);
508 }
509
510 /* Inject a SACK Timeout event into the state machine. */
sctp_generate_sack_event(struct timer_list * t)511 static void sctp_generate_sack_event(struct timer_list *t)
512 {
513 struct sctp_association *asoc =
514 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_SACK]);
515
516 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
517 }
518
519 sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
520 [SCTP_EVENT_TIMEOUT_NONE] = NULL,
521 [SCTP_EVENT_TIMEOUT_T1_COOKIE] = sctp_generate_t1_cookie_event,
522 [SCTP_EVENT_TIMEOUT_T1_INIT] = sctp_generate_t1_init_event,
523 [SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = sctp_generate_t2_shutdown_event,
524 [SCTP_EVENT_TIMEOUT_T3_RTX] = NULL,
525 [SCTP_EVENT_TIMEOUT_T4_RTO] = sctp_generate_t4_rto_event,
526 [SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD] =
527 sctp_generate_t5_shutdown_guard_event,
528 [SCTP_EVENT_TIMEOUT_HEARTBEAT] = NULL,
529 [SCTP_EVENT_TIMEOUT_RECONF] = NULL,
530 [SCTP_EVENT_TIMEOUT_SACK] = sctp_generate_sack_event,
531 [SCTP_EVENT_TIMEOUT_AUTOCLOSE] = sctp_generate_autoclose_event,
532 };
533
534
535 /* RFC 2960 8.2 Path Failure Detection
536 *
537 * When its peer endpoint is multi-homed, an endpoint should keep a
538 * error counter for each of the destination transport addresses of the
539 * peer endpoint.
540 *
541 * Each time the T3-rtx timer expires on any address, or when a
542 * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
543 * the error counter of that destination address will be incremented.
544 * When the value in the error counter exceeds the protocol parameter
545 * 'Path.Max.Retrans' of that destination address, the endpoint should
546 * mark the destination transport address as inactive, and a
547 * notification SHOULD be sent to the upper layer.
548 *
549 */
sctp_do_8_2_transport_strike(struct sctp_cmd_seq * commands,struct sctp_association * asoc,struct sctp_transport * transport,int is_hb)550 static void sctp_do_8_2_transport_strike(struct sctp_cmd_seq *commands,
551 struct sctp_association *asoc,
552 struct sctp_transport *transport,
553 int is_hb)
554 {
555 /* The check for association's overall error counter exceeding the
556 * threshold is done in the state function.
557 */
558 /* We are here due to a timer expiration. If the timer was
559 * not a HEARTBEAT, then normal error tracking is done.
560 * If the timer was a heartbeat, we only increment error counts
561 * when we already have an outstanding HEARTBEAT that has not
562 * been acknowledged.
563 * Additionally, some tranport states inhibit error increments.
564 */
565 if (!is_hb) {
566 asoc->overall_error_count++;
567 if (transport->state != SCTP_INACTIVE)
568 transport->error_count++;
569 } else if (transport->hb_sent) {
570 if (transport->state != SCTP_UNCONFIRMED)
571 asoc->overall_error_count++;
572 if (transport->state != SCTP_INACTIVE)
573 transport->error_count++;
574 }
575
576 /* If the transport error count is greater than the pf_retrans
577 * threshold, and less than pathmaxrtx, and if the current state
578 * is SCTP_ACTIVE, then mark this transport as Partially Failed,
579 * see SCTP Quick Failover Draft, section 5.1
580 */
581 if (asoc->base.net->sctp.pf_enable &&
582 transport->state == SCTP_ACTIVE &&
583 transport->error_count < transport->pathmaxrxt &&
584 transport->error_count > transport->pf_retrans) {
585
586 sctp_assoc_control_transport(asoc, transport,
587 SCTP_TRANSPORT_PF,
588 0);
589
590 /* Update the hb timer to resend a heartbeat every rto */
591 sctp_transport_reset_hb_timer(transport);
592 }
593
594 if (transport->state != SCTP_INACTIVE &&
595 (transport->error_count > transport->pathmaxrxt)) {
596 pr_debug("%s: association:%p transport addr:%pISpc failed\n",
597 __func__, asoc, &transport->ipaddr.sa);
598
599 sctp_assoc_control_transport(asoc, transport,
600 SCTP_TRANSPORT_DOWN,
601 SCTP_FAILED_THRESHOLD);
602 }
603
604 if (transport->error_count > transport->ps_retrans &&
605 asoc->peer.primary_path == transport &&
606 asoc->peer.active_path != transport)
607 sctp_assoc_set_primary(asoc, asoc->peer.active_path);
608
609 /* E2) For the destination address for which the timer
610 * expires, set RTO <- RTO * 2 ("back off the timer"). The
611 * maximum value discussed in rule C7 above (RTO.max) may be
612 * used to provide an upper bound to this doubling operation.
613 *
614 * Special Case: the first HB doesn't trigger exponential backoff.
615 * The first unacknowledged HB triggers it. We do this with a flag
616 * that indicates that we have an outstanding HB.
617 */
618 if (!is_hb || transport->hb_sent) {
619 transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
620 sctp_max_rto(asoc, transport);
621 }
622 }
623
624 /* Worker routine to handle INIT command failure. */
sctp_cmd_init_failed(struct sctp_cmd_seq * commands,struct sctp_association * asoc,unsigned int error)625 static void sctp_cmd_init_failed(struct sctp_cmd_seq *commands,
626 struct sctp_association *asoc,
627 unsigned int error)
628 {
629 struct sctp_ulpevent *event;
630
631 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_CANT_STR_ASSOC,
632 (__u16)error, 0, 0, NULL,
633 GFP_ATOMIC);
634
635 if (event)
636 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
637 SCTP_ULPEVENT(event));
638
639 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
640 SCTP_STATE(SCTP_STATE_CLOSED));
641
642 /* SEND_FAILED sent later when cleaning up the association. */
643 asoc->outqueue.error = error;
644 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
645 }
646
647 /* Worker routine to handle SCTP_CMD_ASSOC_FAILED. */
sctp_cmd_assoc_failed(struct sctp_cmd_seq * commands,struct sctp_association * asoc,enum sctp_event_type event_type,union sctp_subtype subtype,struct sctp_chunk * chunk,unsigned int error)648 static void sctp_cmd_assoc_failed(struct sctp_cmd_seq *commands,
649 struct sctp_association *asoc,
650 enum sctp_event_type event_type,
651 union sctp_subtype subtype,
652 struct sctp_chunk *chunk,
653 unsigned int error)
654 {
655 struct sctp_ulpevent *event;
656 struct sctp_chunk *abort;
657
658 /* Cancel any partial delivery in progress. */
659 asoc->stream.si->abort_pd(&asoc->ulpq, GFP_ATOMIC);
660
661 if (event_type == SCTP_EVENT_T_CHUNK && subtype.chunk == SCTP_CID_ABORT)
662 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
663 (__u16)error, 0, 0, chunk,
664 GFP_ATOMIC);
665 else
666 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
667 (__u16)error, 0, 0, NULL,
668 GFP_ATOMIC);
669 if (event)
670 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
671 SCTP_ULPEVENT(event));
672
673 if (asoc->overall_error_count >= asoc->max_retrans) {
674 abort = sctp_make_violation_max_retrans(asoc, chunk);
675 if (abort)
676 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
677 SCTP_CHUNK(abort));
678 }
679
680 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
681 SCTP_STATE(SCTP_STATE_CLOSED));
682
683 /* SEND_FAILED sent later when cleaning up the association. */
684 asoc->outqueue.error = error;
685 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
686 }
687
688 /* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
689 * inside the cookie. In reality, this is only used for INIT-ACK processing
690 * since all other cases use "temporary" associations and can do all
691 * their work in statefuns directly.
692 */
sctp_cmd_process_init(struct sctp_cmd_seq * commands,struct sctp_association * asoc,struct sctp_chunk * chunk,struct sctp_init_chunk * peer_init,gfp_t gfp)693 static int sctp_cmd_process_init(struct sctp_cmd_seq *commands,
694 struct sctp_association *asoc,
695 struct sctp_chunk *chunk,
696 struct sctp_init_chunk *peer_init,
697 gfp_t gfp)
698 {
699 int error;
700
701 /* We only process the init as a sideeffect in a single
702 * case. This is when we process the INIT-ACK. If we
703 * fail during INIT processing (due to malloc problems),
704 * just return the error and stop processing the stack.
705 */
706 if (!sctp_process_init(asoc, chunk, sctp_source(chunk), peer_init, gfp))
707 error = -ENOMEM;
708 else
709 error = 0;
710
711 return error;
712 }
713
714 /* Helper function to break out starting up of heartbeat timers. */
sctp_cmd_hb_timers_start(struct sctp_cmd_seq * cmds,struct sctp_association * asoc)715 static void sctp_cmd_hb_timers_start(struct sctp_cmd_seq *cmds,
716 struct sctp_association *asoc)
717 {
718 struct sctp_transport *t;
719
720 /* Start a heartbeat timer for each transport on the association.
721 * hold a reference on the transport to make sure none of
722 * the needed data structures go away.
723 */
724 list_for_each_entry(t, &asoc->peer.transport_addr_list, transports)
725 sctp_transport_reset_hb_timer(t);
726 }
727
sctp_cmd_hb_timers_stop(struct sctp_cmd_seq * cmds,struct sctp_association * asoc)728 static void sctp_cmd_hb_timers_stop(struct sctp_cmd_seq *cmds,
729 struct sctp_association *asoc)
730 {
731 struct sctp_transport *t;
732
733 /* Stop all heartbeat timers. */
734
735 list_for_each_entry(t, &asoc->peer.transport_addr_list,
736 transports) {
737 if (del_timer(&t->hb_timer))
738 sctp_transport_put(t);
739 }
740 }
741
742 /* Helper function to stop any pending T3-RTX timers */
sctp_cmd_t3_rtx_timers_stop(struct sctp_cmd_seq * cmds,struct sctp_association * asoc)743 static void sctp_cmd_t3_rtx_timers_stop(struct sctp_cmd_seq *cmds,
744 struct sctp_association *asoc)
745 {
746 struct sctp_transport *t;
747
748 list_for_each_entry(t, &asoc->peer.transport_addr_list,
749 transports) {
750 if (del_timer(&t->T3_rtx_timer))
751 sctp_transport_put(t);
752 }
753 }
754
755
756 /* Helper function to handle the reception of an HEARTBEAT ACK. */
sctp_cmd_transport_on(struct sctp_cmd_seq * cmds,struct sctp_association * asoc,struct sctp_transport * t,struct sctp_chunk * chunk)757 static void sctp_cmd_transport_on(struct sctp_cmd_seq *cmds,
758 struct sctp_association *asoc,
759 struct sctp_transport *t,
760 struct sctp_chunk *chunk)
761 {
762 struct sctp_sender_hb_info *hbinfo;
763 int was_unconfirmed = 0;
764
765 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
766 * HEARTBEAT should clear the error counter of the destination
767 * transport address to which the HEARTBEAT was sent.
768 */
769 t->error_count = 0;
770
771 /*
772 * Although RFC4960 specifies that the overall error count must
773 * be cleared when a HEARTBEAT ACK is received, we make an
774 * exception while in SHUTDOWN PENDING. If the peer keeps its
775 * window shut forever, we may never be able to transmit our
776 * outstanding data and rely on the retransmission limit be reached
777 * to shutdown the association.
778 */
779 if (t->asoc->state < SCTP_STATE_SHUTDOWN_PENDING)
780 t->asoc->overall_error_count = 0;
781
782 /* Clear the hb_sent flag to signal that we had a good
783 * acknowledgement.
784 */
785 t->hb_sent = 0;
786
787 /* Mark the destination transport address as active if it is not so
788 * marked.
789 */
790 if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED)) {
791 was_unconfirmed = 1;
792 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
793 SCTP_HEARTBEAT_SUCCESS);
794 }
795
796 if (t->state == SCTP_PF)
797 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
798 SCTP_HEARTBEAT_SUCCESS);
799
800 /* HB-ACK was received for a the proper HB. Consider this
801 * forward progress.
802 */
803 if (t->dst)
804 sctp_transport_dst_confirm(t);
805
806 /* The receiver of the HEARTBEAT ACK should also perform an
807 * RTT measurement for that destination transport address
808 * using the time value carried in the HEARTBEAT ACK chunk.
809 * If the transport's rto_pending variable has been cleared,
810 * it was most likely due to a retransmit. However, we want
811 * to re-enable it to properly update the rto.
812 */
813 if (t->rto_pending == 0)
814 t->rto_pending = 1;
815
816 hbinfo = (struct sctp_sender_hb_info *)chunk->skb->data;
817 sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
818
819 /* Update the heartbeat timer. */
820 sctp_transport_reset_hb_timer(t);
821
822 if (was_unconfirmed && asoc->peer.transport_count == 1)
823 sctp_transport_immediate_rtx(t);
824 }
825
826
827 /* Helper function to process the process SACK command. */
sctp_cmd_process_sack(struct sctp_cmd_seq * cmds,struct sctp_association * asoc,struct sctp_chunk * chunk)828 static int sctp_cmd_process_sack(struct sctp_cmd_seq *cmds,
829 struct sctp_association *asoc,
830 struct sctp_chunk *chunk)
831 {
832 int err = 0;
833
834 if (sctp_outq_sack(&asoc->outqueue, chunk)) {
835 /* There are no more TSNs awaiting SACK. */
836 err = sctp_do_sm(asoc->base.net, SCTP_EVENT_T_OTHER,
837 SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
838 asoc->state, asoc->ep, asoc, NULL,
839 GFP_ATOMIC);
840 }
841
842 return err;
843 }
844
845 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
846 * the transport for a shutdown chunk.
847 */
sctp_cmd_setup_t2(struct sctp_cmd_seq * cmds,struct sctp_association * asoc,struct sctp_chunk * chunk)848 static void sctp_cmd_setup_t2(struct sctp_cmd_seq *cmds,
849 struct sctp_association *asoc,
850 struct sctp_chunk *chunk)
851 {
852 struct sctp_transport *t;
853
854 if (chunk->transport)
855 t = chunk->transport;
856 else {
857 t = sctp_assoc_choose_alter_transport(asoc,
858 asoc->shutdown_last_sent_to);
859 chunk->transport = t;
860 }
861 asoc->shutdown_last_sent_to = t;
862 asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
863 }
864
865 /* Helper function to change the state of an association. */
sctp_cmd_new_state(struct sctp_cmd_seq * cmds,struct sctp_association * asoc,enum sctp_state state)866 static void sctp_cmd_new_state(struct sctp_cmd_seq *cmds,
867 struct sctp_association *asoc,
868 enum sctp_state state)
869 {
870 struct sock *sk = asoc->base.sk;
871
872 asoc->state = state;
873
874 pr_debug("%s: asoc:%p[%s]\n", __func__, asoc, sctp_state_tbl[state]);
875
876 if (sctp_style(sk, TCP)) {
877 /* Change the sk->sk_state of a TCP-style socket that has
878 * successfully completed a connect() call.
879 */
880 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
881 inet_sk_set_state(sk, SCTP_SS_ESTABLISHED);
882
883 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
884 if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
885 sctp_sstate(sk, ESTABLISHED)) {
886 inet_sk_set_state(sk, SCTP_SS_CLOSING);
887 sk->sk_shutdown |= RCV_SHUTDOWN;
888 }
889 }
890
891 if (sctp_state(asoc, COOKIE_WAIT)) {
892 /* Reset init timeouts since they may have been
893 * increased due to timer expirations.
894 */
895 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
896 asoc->rto_initial;
897 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
898 asoc->rto_initial;
899 }
900
901 if (sctp_state(asoc, ESTABLISHED)) {
902 kfree(asoc->peer.cookie);
903 asoc->peer.cookie = NULL;
904 }
905
906 if (sctp_state(asoc, ESTABLISHED) ||
907 sctp_state(asoc, CLOSED) ||
908 sctp_state(asoc, SHUTDOWN_RECEIVED)) {
909 /* Wake up any processes waiting in the asoc's wait queue in
910 * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
911 */
912 if (waitqueue_active(&asoc->wait))
913 wake_up_interruptible(&asoc->wait);
914
915 /* Wake up any processes waiting in the sk's sleep queue of
916 * a TCP-style or UDP-style peeled-off socket in
917 * sctp_wait_for_accept() or sctp_wait_for_packet().
918 * For a UDP-style socket, the waiters are woken up by the
919 * notifications.
920 */
921 if (!sctp_style(sk, UDP))
922 sk->sk_state_change(sk);
923 }
924
925 if (sctp_state(asoc, SHUTDOWN_PENDING) &&
926 !sctp_outq_is_empty(&asoc->outqueue))
927 sctp_outq_uncork(&asoc->outqueue, GFP_ATOMIC);
928 }
929
930 /* Helper function to delete an association. */
sctp_cmd_delete_tcb(struct sctp_cmd_seq * cmds,struct sctp_association * asoc)931 static void sctp_cmd_delete_tcb(struct sctp_cmd_seq *cmds,
932 struct sctp_association *asoc)
933 {
934 struct sock *sk = asoc->base.sk;
935
936 /* If it is a non-temporary association belonging to a TCP-style
937 * listening socket that is not closed, do not free it so that accept()
938 * can pick it up later.
939 */
940 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
941 (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
942 return;
943
944 sctp_association_free(asoc);
945 }
946
947 /*
948 * ADDIP Section 4.1 ASCONF Chunk Procedures
949 * A4) Start a T-4 RTO timer, using the RTO value of the selected
950 * destination address (we use active path instead of primary path just
951 * because primary path may be inactive.
952 */
sctp_cmd_setup_t4(struct sctp_cmd_seq * cmds,struct sctp_association * asoc,struct sctp_chunk * chunk)953 static void sctp_cmd_setup_t4(struct sctp_cmd_seq *cmds,
954 struct sctp_association *asoc,
955 struct sctp_chunk *chunk)
956 {
957 struct sctp_transport *t;
958
959 t = sctp_assoc_choose_alter_transport(asoc, chunk->transport);
960 asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
961 chunk->transport = t;
962 }
963
964 /* Process an incoming Operation Error Chunk. */
sctp_cmd_process_operr(struct sctp_cmd_seq * cmds,struct sctp_association * asoc,struct sctp_chunk * chunk)965 static void sctp_cmd_process_operr(struct sctp_cmd_seq *cmds,
966 struct sctp_association *asoc,
967 struct sctp_chunk *chunk)
968 {
969 struct sctp_errhdr *err_hdr;
970 struct sctp_ulpevent *ev;
971
972 while (chunk->chunk_end > chunk->skb->data) {
973 err_hdr = (struct sctp_errhdr *)(chunk->skb->data);
974
975 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
976 GFP_ATOMIC);
977 if (!ev)
978 return;
979
980 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
981
982 switch (err_hdr->cause) {
983 case SCTP_ERROR_UNKNOWN_CHUNK:
984 {
985 struct sctp_chunkhdr *unk_chunk_hdr;
986
987 unk_chunk_hdr = (struct sctp_chunkhdr *)
988 err_hdr->variable;
989 switch (unk_chunk_hdr->type) {
990 /* ADDIP 4.1 A9) If the peer responds to an ASCONF with
991 * an ERROR chunk reporting that it did not recognized
992 * the ASCONF chunk type, the sender of the ASCONF MUST
993 * NOT send any further ASCONF chunks and MUST stop its
994 * T-4 timer.
995 */
996 case SCTP_CID_ASCONF:
997 if (asoc->peer.asconf_capable == 0)
998 break;
999
1000 asoc->peer.asconf_capable = 0;
1001 sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
1002 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
1003 break;
1004 default:
1005 break;
1006 }
1007 break;
1008 }
1009 default:
1010 break;
1011 }
1012 }
1013 }
1014
1015 /* Helper function to remove the association non-primary peer
1016 * transports.
1017 */
sctp_cmd_del_non_primary(struct sctp_association * asoc)1018 static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
1019 {
1020 struct sctp_transport *t;
1021 struct list_head *temp;
1022 struct list_head *pos;
1023
1024 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
1025 t = list_entry(pos, struct sctp_transport, transports);
1026 if (!sctp_cmp_addr_exact(&t->ipaddr,
1027 &asoc->peer.primary_addr)) {
1028 sctp_assoc_rm_peer(asoc, t);
1029 }
1030 }
1031 }
1032
1033 /* Helper function to set sk_err on a 1-1 style socket. */
sctp_cmd_set_sk_err(struct sctp_association * asoc,int error)1034 static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
1035 {
1036 struct sock *sk = asoc->base.sk;
1037
1038 if (!sctp_style(sk, UDP))
1039 sk->sk_err = error;
1040 }
1041
1042 /* Helper function to generate an association change event */
sctp_cmd_assoc_change(struct sctp_cmd_seq * commands,struct sctp_association * asoc,u8 state)1043 static void sctp_cmd_assoc_change(struct sctp_cmd_seq *commands,
1044 struct sctp_association *asoc,
1045 u8 state)
1046 {
1047 struct sctp_ulpevent *ev;
1048
1049 ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0,
1050 asoc->c.sinit_num_ostreams,
1051 asoc->c.sinit_max_instreams,
1052 NULL, GFP_ATOMIC);
1053 if (ev)
1054 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
1055 }
1056
sctp_cmd_peer_no_auth(struct sctp_cmd_seq * commands,struct sctp_association * asoc)1057 static void sctp_cmd_peer_no_auth(struct sctp_cmd_seq *commands,
1058 struct sctp_association *asoc)
1059 {
1060 struct sctp_ulpevent *ev;
1061
1062 ev = sctp_ulpevent_make_authkey(asoc, 0, SCTP_AUTH_NO_AUTH, GFP_ATOMIC);
1063 if (ev)
1064 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
1065 }
1066
1067 /* Helper function to generate an adaptation indication event */
sctp_cmd_adaptation_ind(struct sctp_cmd_seq * commands,struct sctp_association * asoc)1068 static void sctp_cmd_adaptation_ind(struct sctp_cmd_seq *commands,
1069 struct sctp_association *asoc)
1070 {
1071 struct sctp_ulpevent *ev;
1072
1073 ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
1074
1075 if (ev)
1076 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
1077 }
1078
1079
sctp_cmd_t1_timer_update(struct sctp_association * asoc,enum sctp_event_timeout timer,char * name)1080 static void sctp_cmd_t1_timer_update(struct sctp_association *asoc,
1081 enum sctp_event_timeout timer,
1082 char *name)
1083 {
1084 struct sctp_transport *t;
1085
1086 t = asoc->init_last_sent_to;
1087 asoc->init_err_counter++;
1088
1089 if (t->init_sent_count > (asoc->init_cycle + 1)) {
1090 asoc->timeouts[timer] *= 2;
1091 if (asoc->timeouts[timer] > asoc->max_init_timeo) {
1092 asoc->timeouts[timer] = asoc->max_init_timeo;
1093 }
1094 asoc->init_cycle++;
1095
1096 pr_debug("%s: T1[%s] timeout adjustment init_err_counter:%d"
1097 " cycle:%d timeout:%ld\n", __func__, name,
1098 asoc->init_err_counter, asoc->init_cycle,
1099 asoc->timeouts[timer]);
1100 }
1101
1102 }
1103
1104 /* Send the whole message, chunk by chunk, to the outqueue.
1105 * This way the whole message is queued up and bundling if
1106 * encouraged for small fragments.
1107 */
sctp_cmd_send_msg(struct sctp_association * asoc,struct sctp_datamsg * msg,gfp_t gfp)1108 static void sctp_cmd_send_msg(struct sctp_association *asoc,
1109 struct sctp_datamsg *msg, gfp_t gfp)
1110 {
1111 struct sctp_chunk *chunk;
1112
1113 list_for_each_entry(chunk, &msg->chunks, frag_list)
1114 sctp_outq_tail(&asoc->outqueue, chunk, gfp);
1115
1116 asoc->outqueue.sched->enqueue(&asoc->outqueue, msg);
1117 }
1118
1119
1120 /* These three macros allow us to pull the debugging code out of the
1121 * main flow of sctp_do_sm() to keep attention focused on the real
1122 * functionality there.
1123 */
1124 #define debug_pre_sfn() \
1125 pr_debug("%s[pre-fn]: ep:%p, %s, %s, asoc:%p[%s], %s\n", __func__, \
1126 ep, sctp_evttype_tbl[event_type], (*debug_fn)(subtype), \
1127 asoc, sctp_state_tbl[state], state_fn->name)
1128
1129 #define debug_post_sfn() \
1130 pr_debug("%s[post-fn]: asoc:%p, status:%s\n", __func__, asoc, \
1131 sctp_status_tbl[status])
1132
1133 #define debug_post_sfx() \
1134 pr_debug("%s[post-sfx]: error:%d, asoc:%p[%s]\n", __func__, error, \
1135 asoc, sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
1136 sctp_assoc2id(asoc))) ? asoc->state : SCTP_STATE_CLOSED])
1137
1138 /*
1139 * This is the master state machine processing function.
1140 *
1141 * If you want to understand all of lksctp, this is a
1142 * good place to start.
1143 */
sctp_do_sm(struct net * net,enum sctp_event_type event_type,union sctp_subtype subtype,enum sctp_state state,struct sctp_endpoint * ep,struct sctp_association * asoc,void * event_arg,gfp_t gfp)1144 int sctp_do_sm(struct net *net, enum sctp_event_type event_type,
1145 union sctp_subtype subtype, enum sctp_state state,
1146 struct sctp_endpoint *ep, struct sctp_association *asoc,
1147 void *event_arg, gfp_t gfp)
1148 {
1149 typedef const char *(printfn_t)(union sctp_subtype);
1150 static printfn_t *table[] = {
1151 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
1152 };
1153 printfn_t *debug_fn __attribute__ ((unused)) = table[event_type];
1154 const struct sctp_sm_table_entry *state_fn;
1155 struct sctp_cmd_seq commands;
1156 enum sctp_disposition status;
1157 int error = 0;
1158
1159 /* Look up the state function, run it, and then process the
1160 * side effects. These three steps are the heart of lksctp.
1161 */
1162 state_fn = sctp_sm_lookup_event(net, event_type, state, subtype);
1163
1164 sctp_init_cmd_seq(&commands);
1165
1166 debug_pre_sfn();
1167 status = state_fn->fn(net, ep, asoc, subtype, event_arg, &commands);
1168 debug_post_sfn();
1169
1170 error = sctp_side_effects(event_type, subtype, state,
1171 ep, &asoc, event_arg, status,
1172 &commands, gfp);
1173 debug_post_sfx();
1174
1175 return error;
1176 }
1177
1178 /*****************************************************************
1179 * This the master state function side effect processing function.
1180 *****************************************************************/
sctp_side_effects(enum sctp_event_type event_type,union sctp_subtype subtype,enum sctp_state state,struct sctp_endpoint * ep,struct sctp_association ** asoc,void * event_arg,enum sctp_disposition status,struct sctp_cmd_seq * commands,gfp_t gfp)1181 static int sctp_side_effects(enum sctp_event_type event_type,
1182 union sctp_subtype subtype,
1183 enum sctp_state state,
1184 struct sctp_endpoint *ep,
1185 struct sctp_association **asoc,
1186 void *event_arg,
1187 enum sctp_disposition status,
1188 struct sctp_cmd_seq *commands,
1189 gfp_t gfp)
1190 {
1191 int error;
1192
1193 /* FIXME - Most of the dispositions left today would be categorized
1194 * as "exceptional" dispositions. For those dispositions, it
1195 * may not be proper to run through any of the commands at all.
1196 * For example, the command interpreter might be run only with
1197 * disposition SCTP_DISPOSITION_CONSUME.
1198 */
1199 if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
1200 ep, *asoc,
1201 event_arg, status,
1202 commands, gfp)))
1203 goto bail;
1204
1205 switch (status) {
1206 case SCTP_DISPOSITION_DISCARD:
1207 pr_debug("%s: ignored sctp protocol event - state:%d, "
1208 "event_type:%d, event_id:%d\n", __func__, state,
1209 event_type, subtype.chunk);
1210 break;
1211
1212 case SCTP_DISPOSITION_NOMEM:
1213 /* We ran out of memory, so we need to discard this
1214 * packet.
1215 */
1216 /* BUG--we should now recover some memory, probably by
1217 * reneging...
1218 */
1219 error = -ENOMEM;
1220 break;
1221
1222 case SCTP_DISPOSITION_DELETE_TCB:
1223 case SCTP_DISPOSITION_ABORT:
1224 /* This should now be a command. */
1225 *asoc = NULL;
1226 break;
1227
1228 case SCTP_DISPOSITION_CONSUME:
1229 /*
1230 * We should no longer have much work to do here as the
1231 * real work has been done as explicit commands above.
1232 */
1233 break;
1234
1235 case SCTP_DISPOSITION_VIOLATION:
1236 net_err_ratelimited("protocol violation state %d chunkid %d\n",
1237 state, subtype.chunk);
1238 break;
1239
1240 case SCTP_DISPOSITION_NOT_IMPL:
1241 pr_warn("unimplemented feature in state %d, event_type %d, event_id %d\n",
1242 state, event_type, subtype.chunk);
1243 break;
1244
1245 case SCTP_DISPOSITION_BUG:
1246 pr_err("bug in state %d, event_type %d, event_id %d\n",
1247 state, event_type, subtype.chunk);
1248 BUG();
1249 break;
1250
1251 default:
1252 pr_err("impossible disposition %d in state %d, event_type %d, event_id %d\n",
1253 status, state, event_type, subtype.chunk);
1254 error = status;
1255 if (error >= 0)
1256 error = -EINVAL;
1257 WARN_ON_ONCE(1);
1258 break;
1259 }
1260
1261 bail:
1262 return error;
1263 }
1264
1265 /********************************************************************
1266 * 2nd Level Abstractions
1267 ********************************************************************/
1268
1269 /* This is the side-effect interpreter. */
sctp_cmd_interpreter(enum sctp_event_type event_type,union sctp_subtype subtype,enum sctp_state state,struct sctp_endpoint * ep,struct sctp_association * asoc,void * event_arg,enum sctp_disposition status,struct sctp_cmd_seq * commands,gfp_t gfp)1270 static int sctp_cmd_interpreter(enum sctp_event_type event_type,
1271 union sctp_subtype subtype,
1272 enum sctp_state state,
1273 struct sctp_endpoint *ep,
1274 struct sctp_association *asoc,
1275 void *event_arg,
1276 enum sctp_disposition status,
1277 struct sctp_cmd_seq *commands,
1278 gfp_t gfp)
1279 {
1280 struct sctp_sock *sp = sctp_sk(ep->base.sk);
1281 struct sctp_chunk *chunk = NULL, *new_obj;
1282 struct sctp_packet *packet;
1283 struct sctp_sackhdr sackh;
1284 struct timer_list *timer;
1285 struct sctp_transport *t;
1286 unsigned long timeout;
1287 struct sctp_cmd *cmd;
1288 int local_cork = 0;
1289 int error = 0;
1290 int force;
1291
1292 if (SCTP_EVENT_T_TIMEOUT != event_type)
1293 chunk = event_arg;
1294
1295 /* Note: This whole file is a huge candidate for rework.
1296 * For example, each command could either have its own handler, so
1297 * the loop would look like:
1298 * while (cmds)
1299 * cmd->handle(x, y, z)
1300 * --jgrimm
1301 */
1302 while (NULL != (cmd = sctp_next_cmd(commands))) {
1303 switch (cmd->verb) {
1304 case SCTP_CMD_NOP:
1305 /* Do nothing. */
1306 break;
1307
1308 case SCTP_CMD_NEW_ASOC:
1309 /* Register a new association. */
1310 if (local_cork) {
1311 sctp_outq_uncork(&asoc->outqueue, gfp);
1312 local_cork = 0;
1313 }
1314
1315 /* Register with the endpoint. */
1316 asoc = cmd->obj.asoc;
1317 BUG_ON(asoc->peer.primary_path == NULL);
1318 sctp_endpoint_add_asoc(ep, asoc);
1319 break;
1320
1321 case SCTP_CMD_PURGE_OUTQUEUE:
1322 sctp_outq_teardown(&asoc->outqueue);
1323 break;
1324
1325 case SCTP_CMD_DELETE_TCB:
1326 if (local_cork) {
1327 sctp_outq_uncork(&asoc->outqueue, gfp);
1328 local_cork = 0;
1329 }
1330 /* Delete the current association. */
1331 sctp_cmd_delete_tcb(commands, asoc);
1332 asoc = NULL;
1333 break;
1334
1335 case SCTP_CMD_NEW_STATE:
1336 /* Enter a new state. */
1337 sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1338 break;
1339
1340 case SCTP_CMD_REPORT_TSN:
1341 /* Record the arrival of a TSN. */
1342 error = sctp_tsnmap_mark(&asoc->peer.tsn_map,
1343 cmd->obj.u32, NULL);
1344 break;
1345
1346 case SCTP_CMD_REPORT_FWDTSN:
1347 asoc->stream.si->report_ftsn(&asoc->ulpq, cmd->obj.u32);
1348 break;
1349
1350 case SCTP_CMD_PROCESS_FWDTSN:
1351 asoc->stream.si->handle_ftsn(&asoc->ulpq,
1352 cmd->obj.chunk);
1353 break;
1354
1355 case SCTP_CMD_GEN_SACK:
1356 /* Generate a Selective ACK.
1357 * The argument tells us whether to just count
1358 * the packet and MAYBE generate a SACK, or
1359 * force a SACK out.
1360 */
1361 force = cmd->obj.i32;
1362 error = sctp_gen_sack(asoc, force, commands);
1363 break;
1364
1365 case SCTP_CMD_PROCESS_SACK:
1366 /* Process an inbound SACK. */
1367 error = sctp_cmd_process_sack(commands, asoc,
1368 cmd->obj.chunk);
1369 break;
1370
1371 case SCTP_CMD_GEN_INIT_ACK:
1372 /* Generate an INIT ACK chunk. */
1373 new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1374 0);
1375 if (!new_obj) {
1376 error = -ENOMEM;
1377 break;
1378 }
1379
1380 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1381 SCTP_CHUNK(new_obj));
1382 break;
1383
1384 case SCTP_CMD_PEER_INIT:
1385 /* Process a unified INIT from the peer.
1386 * Note: Only used during INIT-ACK processing. If
1387 * there is an error just return to the outter
1388 * layer which will bail.
1389 */
1390 error = sctp_cmd_process_init(commands, asoc, chunk,
1391 cmd->obj.init, gfp);
1392 break;
1393
1394 case SCTP_CMD_GEN_COOKIE_ECHO:
1395 /* Generate a COOKIE ECHO chunk. */
1396 new_obj = sctp_make_cookie_echo(asoc, chunk);
1397 if (!new_obj) {
1398 if (cmd->obj.chunk)
1399 sctp_chunk_free(cmd->obj.chunk);
1400 error = -ENOMEM;
1401 break;
1402 }
1403 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1404 SCTP_CHUNK(new_obj));
1405
1406 /* If there is an ERROR chunk to be sent along with
1407 * the COOKIE_ECHO, send it, too.
1408 */
1409 if (cmd->obj.chunk)
1410 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1411 SCTP_CHUNK(cmd->obj.chunk));
1412
1413 if (new_obj->transport) {
1414 new_obj->transport->init_sent_count++;
1415 asoc->init_last_sent_to = new_obj->transport;
1416 }
1417
1418 /* FIXME - Eventually come up with a cleaner way to
1419 * enabling COOKIE-ECHO + DATA bundling during
1420 * multihoming stale cookie scenarios, the following
1421 * command plays with asoc->peer.retran_path to
1422 * avoid the problem of sending the COOKIE-ECHO and
1423 * DATA in different paths, which could result
1424 * in the association being ABORTed if the DATA chunk
1425 * is processed first by the server. Checking the
1426 * init error counter simply causes this command
1427 * to be executed only during failed attempts of
1428 * association establishment.
1429 */
1430 if ((asoc->peer.retran_path !=
1431 asoc->peer.primary_path) &&
1432 (asoc->init_err_counter > 0)) {
1433 sctp_add_cmd_sf(commands,
1434 SCTP_CMD_FORCE_PRIM_RETRAN,
1435 SCTP_NULL());
1436 }
1437
1438 break;
1439
1440 case SCTP_CMD_GEN_SHUTDOWN:
1441 /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1442 * Reset error counts.
1443 */
1444 asoc->overall_error_count = 0;
1445
1446 /* Generate a SHUTDOWN chunk. */
1447 new_obj = sctp_make_shutdown(asoc, chunk);
1448 if (!new_obj) {
1449 error = -ENOMEM;
1450 break;
1451 }
1452 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1453 SCTP_CHUNK(new_obj));
1454 break;
1455
1456 case SCTP_CMD_CHUNK_ULP:
1457 /* Send a chunk to the sockets layer. */
1458 pr_debug("%s: sm_sideff: chunk_up:%p, ulpq:%p\n",
1459 __func__, cmd->obj.chunk, &asoc->ulpq);
1460
1461 asoc->stream.si->ulpevent_data(&asoc->ulpq,
1462 cmd->obj.chunk,
1463 GFP_ATOMIC);
1464 break;
1465
1466 case SCTP_CMD_EVENT_ULP:
1467 /* Send a notification to the sockets layer. */
1468 pr_debug("%s: sm_sideff: event_up:%p, ulpq:%p\n",
1469 __func__, cmd->obj.ulpevent, &asoc->ulpq);
1470
1471 asoc->stream.si->enqueue_event(&asoc->ulpq,
1472 cmd->obj.ulpevent);
1473 break;
1474
1475 case SCTP_CMD_REPLY:
1476 /* If an caller has not already corked, do cork. */
1477 if (!asoc->outqueue.cork) {
1478 sctp_outq_cork(&asoc->outqueue);
1479 local_cork = 1;
1480 }
1481 /* Send a chunk to our peer. */
1482 sctp_outq_tail(&asoc->outqueue, cmd->obj.chunk, gfp);
1483 break;
1484
1485 case SCTP_CMD_SEND_PKT:
1486 /* Send a full packet to our peer. */
1487 packet = cmd->obj.packet;
1488 sctp_packet_transmit(packet, gfp);
1489 sctp_ootb_pkt_free(packet);
1490 break;
1491
1492 case SCTP_CMD_T1_RETRAN:
1493 /* Mark a transport for retransmission. */
1494 sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1495 SCTP_RTXR_T1_RTX);
1496 break;
1497
1498 case SCTP_CMD_RETRAN:
1499 /* Mark a transport for retransmission. */
1500 sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1501 SCTP_RTXR_T3_RTX);
1502 break;
1503
1504 case SCTP_CMD_ECN_CE:
1505 /* Do delayed CE processing. */
1506 sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1507 break;
1508
1509 case SCTP_CMD_ECN_ECNE:
1510 /* Do delayed ECNE processing. */
1511 new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1512 chunk);
1513 if (new_obj)
1514 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1515 SCTP_CHUNK(new_obj));
1516 break;
1517
1518 case SCTP_CMD_ECN_CWR:
1519 /* Do delayed CWR processing. */
1520 sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1521 break;
1522
1523 case SCTP_CMD_SETUP_T2:
1524 sctp_cmd_setup_t2(commands, asoc, cmd->obj.chunk);
1525 break;
1526
1527 case SCTP_CMD_TIMER_START_ONCE:
1528 timer = &asoc->timers[cmd->obj.to];
1529
1530 if (timer_pending(timer))
1531 break;
1532 fallthrough;
1533
1534 case SCTP_CMD_TIMER_START:
1535 timer = &asoc->timers[cmd->obj.to];
1536 timeout = asoc->timeouts[cmd->obj.to];
1537 BUG_ON(!timeout);
1538
1539 /*
1540 * SCTP has a hard time with timer starts. Because we process
1541 * timer starts as side effects, it can be hard to tell if we
1542 * have already started a timer or not, which leads to BUG
1543 * halts when we call add_timer. So here, instead of just starting
1544 * a timer, if the timer is already started, and just mod
1545 * the timer with the shorter of the two expiration times
1546 */
1547 if (!timer_pending(timer))
1548 sctp_association_hold(asoc);
1549 timer_reduce(timer, jiffies + timeout);
1550 break;
1551
1552 case SCTP_CMD_TIMER_RESTART:
1553 timer = &asoc->timers[cmd->obj.to];
1554 timeout = asoc->timeouts[cmd->obj.to];
1555 if (!mod_timer(timer, jiffies + timeout))
1556 sctp_association_hold(asoc);
1557 break;
1558
1559 case SCTP_CMD_TIMER_STOP:
1560 timer = &asoc->timers[cmd->obj.to];
1561 if (del_timer(timer))
1562 sctp_association_put(asoc);
1563 break;
1564
1565 case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1566 chunk = cmd->obj.chunk;
1567 t = sctp_assoc_choose_alter_transport(asoc,
1568 asoc->init_last_sent_to);
1569 asoc->init_last_sent_to = t;
1570 chunk->transport = t;
1571 t->init_sent_count++;
1572 /* Set the new transport as primary */
1573 sctp_assoc_set_primary(asoc, t);
1574 break;
1575
1576 case SCTP_CMD_INIT_RESTART:
1577 /* Do the needed accounting and updates
1578 * associated with restarting an initialization
1579 * timer. Only multiply the timeout by two if
1580 * all transports have been tried at the current
1581 * timeout.
1582 */
1583 sctp_cmd_t1_timer_update(asoc,
1584 SCTP_EVENT_TIMEOUT_T1_INIT,
1585 "INIT");
1586
1587 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1588 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1589 break;
1590
1591 case SCTP_CMD_COOKIEECHO_RESTART:
1592 /* Do the needed accounting and updates
1593 * associated with restarting an initialization
1594 * timer. Only multiply the timeout by two if
1595 * all transports have been tried at the current
1596 * timeout.
1597 */
1598 sctp_cmd_t1_timer_update(asoc,
1599 SCTP_EVENT_TIMEOUT_T1_COOKIE,
1600 "COOKIE");
1601
1602 /* If we've sent any data bundled with
1603 * COOKIE-ECHO we need to resend.
1604 */
1605 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1606 transports) {
1607 sctp_retransmit_mark(&asoc->outqueue, t,
1608 SCTP_RTXR_T1_RTX);
1609 }
1610
1611 sctp_add_cmd_sf(commands,
1612 SCTP_CMD_TIMER_RESTART,
1613 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1614 break;
1615
1616 case SCTP_CMD_INIT_FAILED:
1617 sctp_cmd_init_failed(commands, asoc, cmd->obj.u16);
1618 break;
1619
1620 case SCTP_CMD_ASSOC_FAILED:
1621 sctp_cmd_assoc_failed(commands, asoc, event_type,
1622 subtype, chunk, cmd->obj.u16);
1623 break;
1624
1625 case SCTP_CMD_INIT_COUNTER_INC:
1626 asoc->init_err_counter++;
1627 break;
1628
1629 case SCTP_CMD_INIT_COUNTER_RESET:
1630 asoc->init_err_counter = 0;
1631 asoc->init_cycle = 0;
1632 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1633 transports) {
1634 t->init_sent_count = 0;
1635 }
1636 break;
1637
1638 case SCTP_CMD_REPORT_DUP:
1639 sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1640 cmd->obj.u32);
1641 break;
1642
1643 case SCTP_CMD_REPORT_BAD_TAG:
1644 pr_debug("%s: vtag mismatch!\n", __func__);
1645 break;
1646
1647 case SCTP_CMD_STRIKE:
1648 /* Mark one strike against a transport. */
1649 sctp_do_8_2_transport_strike(commands, asoc,
1650 cmd->obj.transport, 0);
1651 break;
1652
1653 case SCTP_CMD_TRANSPORT_IDLE:
1654 t = cmd->obj.transport;
1655 sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
1656 break;
1657
1658 case SCTP_CMD_TRANSPORT_HB_SENT:
1659 t = cmd->obj.transport;
1660 sctp_do_8_2_transport_strike(commands, asoc,
1661 t, 1);
1662 t->hb_sent = 1;
1663 break;
1664
1665 case SCTP_CMD_TRANSPORT_ON:
1666 t = cmd->obj.transport;
1667 sctp_cmd_transport_on(commands, asoc, t, chunk);
1668 break;
1669
1670 case SCTP_CMD_HB_TIMERS_START:
1671 sctp_cmd_hb_timers_start(commands, asoc);
1672 break;
1673
1674 case SCTP_CMD_HB_TIMER_UPDATE:
1675 t = cmd->obj.transport;
1676 sctp_transport_reset_hb_timer(t);
1677 break;
1678
1679 case SCTP_CMD_HB_TIMERS_STOP:
1680 sctp_cmd_hb_timers_stop(commands, asoc);
1681 break;
1682
1683 case SCTP_CMD_PROBE_TIMER_UPDATE:
1684 t = cmd->obj.transport;
1685 sctp_transport_reset_probe_timer(t);
1686 break;
1687
1688 case SCTP_CMD_REPORT_ERROR:
1689 error = cmd->obj.error;
1690 break;
1691
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,
1701 SCTP_CHUNK(chunk));
1702 break;
1703
1704 case SCTP_CMD_DISCARD_PACKET:
1705 /* We need to discard the whole packet.
1706 * Uncork the queue since there might be
1707 * responses pending
1708 */
1709 chunk->pdiscard = 1;
1710 if (asoc) {
1711 sctp_outq_uncork(&asoc->outqueue, gfp);
1712 local_cork = 0;
1713 }
1714 break;
1715
1716 case SCTP_CMD_RTO_PENDING:
1717 t = cmd->obj.transport;
1718 t->rto_pending = 1;
1719 break;
1720
1721 case SCTP_CMD_PART_DELIVER:
1722 asoc->stream.si->start_pd(&asoc->ulpq, GFP_ATOMIC);
1723 break;
1724
1725 case SCTP_CMD_RENEGE:
1726 asoc->stream.si->renege_events(&asoc->ulpq,
1727 cmd->obj.chunk,
1728 GFP_ATOMIC);
1729 break;
1730
1731 case SCTP_CMD_SETUP_T4:
1732 sctp_cmd_setup_t4(commands, asoc, cmd->obj.chunk);
1733 break;
1734
1735 case SCTP_CMD_PROCESS_OPERR:
1736 sctp_cmd_process_operr(commands, asoc, chunk);
1737 break;
1738 case SCTP_CMD_CLEAR_INIT_TAG:
1739 asoc->peer.i.init_tag = 0;
1740 break;
1741 case SCTP_CMD_DEL_NON_PRIMARY:
1742 sctp_cmd_del_non_primary(asoc);
1743 break;
1744 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1745 sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1746 break;
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);
1751 local_cork = 0;
1752 asoc->peer.retran_path = t;
1753 break;
1754 case SCTP_CMD_SET_SK_ERR:
1755 sctp_cmd_set_sk_err(asoc, cmd->obj.error);
1756 break;
1757 case SCTP_CMD_ASSOC_CHANGE:
1758 sctp_cmd_assoc_change(commands, asoc,
1759 cmd->obj.u8);
1760 break;
1761 case SCTP_CMD_ADAPTATION_IND:
1762 sctp_cmd_adaptation_ind(commands, asoc);
1763 break;
1764 case SCTP_CMD_PEER_NO_AUTH:
1765 sctp_cmd_peer_no_auth(commands, asoc);
1766 break;
1767
1768 case SCTP_CMD_ASSOC_SHKEY:
1769 error = sctp_auth_asoc_init_active_key(asoc,
1770 GFP_ATOMIC);
1771 break;
1772 case SCTP_CMD_UPDATE_INITTAG:
1773 asoc->peer.i.init_tag = cmd->obj.u32;
1774 break;
1775 case SCTP_CMD_SEND_MSG:
1776 if (!asoc->outqueue.cork) {
1777 sctp_outq_cork(&asoc->outqueue);
1778 local_cork = 1;
1779 }
1780 sctp_cmd_send_msg(asoc, cmd->obj.msg, gfp);
1781 break;
1782 case SCTP_CMD_PURGE_ASCONF_QUEUE:
1783 sctp_asconf_queue_teardown(asoc);
1784 break;
1785
1786 case SCTP_CMD_SET_ASOC:
1787 if (asoc && local_cork) {
1788 sctp_outq_uncork(&asoc->outqueue, gfp);
1789 local_cork = 0;
1790 }
1791 asoc = cmd->obj.asoc;
1792 break;
1793
1794 default:
1795 pr_warn("Impossible command: %u\n",
1796 cmd->verb);
1797 break;
1798 }
1799
1800 if (error) {
1801 cmd = sctp_next_cmd(commands);
1802 while (cmd) {
1803 if (cmd->verb == SCTP_CMD_REPLY)
1804 sctp_chunk_free(cmd->obj.chunk);
1805 cmd = sctp_next_cmd(commands);
1806 }
1807 break;
1808 }
1809 }
1810
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.
1814 */
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);
1820
1821 if (sp->data_ready_signalled)
1822 sp->data_ready_signalled = 0;
1823
1824 return error;
1825 }
1826