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 timer_container_of(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 sctp_transport_hold(transport);
248 if (mod_timer(&transport->T3_rtx_timer, jiffies + (HZ / 20)))
249 sctp_transport_put(transport);
250 goto out_unlock;
251 }
252
253 /* Run through the state machine. */
254 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
255 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX),
256 asoc->state,
257 asoc->ep, asoc,
258 transport, GFP_ATOMIC);
259
260 if (error)
261 sk->sk_err = -error;
262
263 out_unlock:
264 bh_unlock_sock(sk);
265 sctp_transport_put(transport);
266 }
267
268 /* This is a sa interface for producing timeout events. It works
269 * for timeouts which use the association as their parameter.
270 */
sctp_generate_timeout_event(struct sctp_association * asoc,enum sctp_event_timeout timeout_type)271 static void sctp_generate_timeout_event(struct sctp_association *asoc,
272 enum sctp_event_timeout timeout_type)
273 {
274 struct sock *sk = asoc->base.sk;
275 struct net *net = sock_net(sk);
276 int error = 0;
277
278 bh_lock_sock(sk);
279 if (sock_owned_by_user(sk)) {
280 pr_debug("%s: sock is busy: timer %d\n", __func__,
281 timeout_type);
282
283 /* Try again later. */
284 sctp_association_hold(asoc);
285 if (mod_timer(&asoc->timers[timeout_type], jiffies + (HZ / 20)))
286 sctp_association_put(asoc);
287 goto out_unlock;
288 }
289
290 /* Is this association really dead and just waiting around for
291 * the timer to let go of the reference?
292 */
293 if (asoc->base.dead)
294 goto out_unlock;
295
296 /* Run through the state machine. */
297 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
298 SCTP_ST_TIMEOUT(timeout_type),
299 asoc->state, asoc->ep, asoc,
300 (void *)timeout_type, GFP_ATOMIC);
301
302 if (error)
303 sk->sk_err = -error;
304
305 out_unlock:
306 bh_unlock_sock(sk);
307 sctp_association_put(asoc);
308 }
309
sctp_generate_t1_cookie_event(struct timer_list * t)310 static void sctp_generate_t1_cookie_event(struct timer_list *t)
311 {
312 struct sctp_association *asoc =
313 timer_container_of(asoc, t,
314 timers[SCTP_EVENT_TIMEOUT_T1_COOKIE]);
315
316 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
317 }
318
sctp_generate_t1_init_event(struct timer_list * t)319 static void sctp_generate_t1_init_event(struct timer_list *t)
320 {
321 struct sctp_association *asoc =
322 timer_container_of(asoc, t,
323 timers[SCTP_EVENT_TIMEOUT_T1_INIT]);
324
325 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
326 }
327
sctp_generate_t2_shutdown_event(struct timer_list * t)328 static void sctp_generate_t2_shutdown_event(struct timer_list *t)
329 {
330 struct sctp_association *asoc =
331 timer_container_of(asoc, t,
332 timers[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN]);
333
334 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
335 }
336
sctp_generate_t4_rto_event(struct timer_list * t)337 static void sctp_generate_t4_rto_event(struct timer_list *t)
338 {
339 struct sctp_association *asoc =
340 timer_container_of(asoc, t, timers[SCTP_EVENT_TIMEOUT_T4_RTO]);
341
342 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
343 }
344
sctp_generate_t5_shutdown_guard_event(struct timer_list * t)345 static void sctp_generate_t5_shutdown_guard_event(struct timer_list *t)
346 {
347 struct sctp_association *asoc =
348 timer_container_of(asoc, t,
349 timers[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD]);
350
351 sctp_generate_timeout_event(asoc,
352 SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);
353
354 } /* sctp_generate_t5_shutdown_guard_event() */
355
sctp_generate_autoclose_event(struct timer_list * t)356 static void sctp_generate_autoclose_event(struct timer_list *t)
357 {
358 struct sctp_association *asoc =
359 timer_container_of(asoc, t,
360 timers[SCTP_EVENT_TIMEOUT_AUTOCLOSE]);
361
362 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE);
363 }
364
365 /* Generate a heart beat event. If the sock is busy, reschedule. Make
366 * sure that the transport is still valid.
367 */
sctp_generate_heartbeat_event(struct timer_list * t)368 void sctp_generate_heartbeat_event(struct timer_list *t)
369 {
370 struct sctp_transport *transport = timer_container_of(transport, t,
371 hb_timer);
372 struct sctp_association *asoc = transport->asoc;
373 struct sock *sk = asoc->base.sk;
374 struct net *net = sock_net(sk);
375 u32 elapsed, timeout;
376 int error = 0;
377
378 bh_lock_sock(sk);
379 if (sock_owned_by_user(sk)) {
380 pr_debug("%s: sock is busy\n", __func__);
381
382 /* Try again later. */
383 sctp_transport_hold(transport);
384 if (mod_timer(&transport->hb_timer, jiffies + (HZ / 20)))
385 sctp_transport_put(transport);
386 goto out_unlock;
387 }
388
389 /* Check if we should still send the heartbeat or reschedule */
390 elapsed = jiffies - transport->last_time_sent;
391 timeout = sctp_transport_timeout(transport);
392 if (elapsed < timeout) {
393 elapsed = timeout - elapsed;
394 sctp_transport_hold(transport);
395 if (mod_timer(&transport->hb_timer, jiffies + elapsed))
396 sctp_transport_put(transport);
397 goto out_unlock;
398 }
399
400 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
401 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
402 asoc->state, asoc->ep, asoc,
403 transport, GFP_ATOMIC);
404
405 if (error)
406 sk->sk_err = -error;
407
408 out_unlock:
409 bh_unlock_sock(sk);
410 sctp_transport_put(transport);
411 }
412
413 /* Handle the timeout of the ICMP protocol unreachable timer. Trigger
414 * the correct state machine transition that will close the association.
415 */
sctp_generate_proto_unreach_event(struct timer_list * t)416 void sctp_generate_proto_unreach_event(struct timer_list *t)
417 {
418 struct sctp_transport *transport =
419 timer_container_of(transport, t, proto_unreach_timer);
420 struct sctp_association *asoc = transport->asoc;
421 struct sock *sk = asoc->base.sk;
422 struct net *net = sock_net(sk);
423
424 bh_lock_sock(sk);
425 if (sock_owned_by_user(sk)) {
426 pr_debug("%s: sock is busy\n", __func__);
427
428 /* Try again later. */
429 sctp_transport_hold(transport);
430 if (mod_timer(&transport->proto_unreach_timer,
431 jiffies + (HZ / 20)))
432 sctp_transport_put(transport);
433 goto out_unlock;
434 }
435
436 /* Is this structure just waiting around for us to actually
437 * get destroyed?
438 */
439 if (asoc->base.dead)
440 goto out_unlock;
441
442 sctp_do_sm(net, SCTP_EVENT_T_OTHER,
443 SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH),
444 asoc->state, asoc->ep, asoc, transport, GFP_ATOMIC);
445
446 out_unlock:
447 bh_unlock_sock(sk);
448 sctp_transport_put(transport);
449 }
450
451 /* Handle the timeout of the RE-CONFIG timer. */
sctp_generate_reconf_event(struct timer_list * t)452 void sctp_generate_reconf_event(struct timer_list *t)
453 {
454 struct sctp_transport *transport =
455 timer_container_of(transport, t, reconf_timer);
456 struct sctp_association *asoc = transport->asoc;
457 struct sock *sk = asoc->base.sk;
458 struct net *net = sock_net(sk);
459 int error = 0;
460
461 bh_lock_sock(sk);
462 if (sock_owned_by_user(sk)) {
463 pr_debug("%s: sock is busy\n", __func__);
464
465 /* Try again later. */
466 sctp_transport_hold(transport);
467 if (mod_timer(&transport->reconf_timer, jiffies + (HZ / 20)))
468 sctp_transport_put(transport);
469 goto out_unlock;
470 }
471
472 /* This happens when the response arrives after the timer is triggered. */
473 if (!asoc->strreset_chunk)
474 goto out_unlock;
475
476 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
477 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_RECONF),
478 asoc->state, asoc->ep, asoc,
479 transport, GFP_ATOMIC);
480
481 if (error)
482 sk->sk_err = -error;
483
484 out_unlock:
485 bh_unlock_sock(sk);
486 sctp_transport_put(transport);
487 }
488
489 /* Handle the timeout of the probe timer. */
sctp_generate_probe_event(struct timer_list * t)490 void sctp_generate_probe_event(struct timer_list *t)
491 {
492 struct sctp_transport *transport = timer_container_of(transport, t,
493 probe_timer);
494 struct sctp_association *asoc = transport->asoc;
495 struct sock *sk = asoc->base.sk;
496 struct net *net = sock_net(sk);
497 int error = 0;
498
499 bh_lock_sock(sk);
500 if (sock_owned_by_user(sk)) {
501 pr_debug("%s: sock is busy\n", __func__);
502
503 /* Try again later. */
504 sctp_transport_hold(transport);
505 if (mod_timer(&transport->probe_timer, jiffies + (HZ / 20)))
506 sctp_transport_put(transport);
507 goto out_unlock;
508 }
509
510 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
511 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_PROBE),
512 asoc->state, asoc->ep, asoc,
513 transport, GFP_ATOMIC);
514
515 if (error)
516 sk->sk_err = -error;
517
518 out_unlock:
519 bh_unlock_sock(sk);
520 sctp_transport_put(transport);
521 }
522
523 /* Inject a SACK Timeout event into the state machine. */
sctp_generate_sack_event(struct timer_list * t)524 static void sctp_generate_sack_event(struct timer_list *t)
525 {
526 struct sctp_association *asoc =
527 timer_container_of(asoc, t, timers[SCTP_EVENT_TIMEOUT_SACK]);
528
529 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
530 }
531
532 sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
533 [SCTP_EVENT_TIMEOUT_NONE] = NULL,
534 [SCTP_EVENT_TIMEOUT_T1_COOKIE] = sctp_generate_t1_cookie_event,
535 [SCTP_EVENT_TIMEOUT_T1_INIT] = sctp_generate_t1_init_event,
536 [SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = sctp_generate_t2_shutdown_event,
537 [SCTP_EVENT_TIMEOUT_T3_RTX] = NULL,
538 [SCTP_EVENT_TIMEOUT_T4_RTO] = sctp_generate_t4_rto_event,
539 [SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD] =
540 sctp_generate_t5_shutdown_guard_event,
541 [SCTP_EVENT_TIMEOUT_HEARTBEAT] = NULL,
542 [SCTP_EVENT_TIMEOUT_RECONF] = NULL,
543 [SCTP_EVENT_TIMEOUT_SACK] = sctp_generate_sack_event,
544 [SCTP_EVENT_TIMEOUT_AUTOCLOSE] = sctp_generate_autoclose_event,
545 };
546
547
548 /* RFC 2960 8.2 Path Failure Detection
549 *
550 * When its peer endpoint is multi-homed, an endpoint should keep a
551 * error counter for each of the destination transport addresses of the
552 * peer endpoint.
553 *
554 * Each time the T3-rtx timer expires on any address, or when a
555 * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
556 * the error counter of that destination address will be incremented.
557 * When the value in the error counter exceeds the protocol parameter
558 * 'Path.Max.Retrans' of that destination address, the endpoint should
559 * mark the destination transport address as inactive, and a
560 * notification SHOULD be sent to the upper layer.
561 *
562 */
sctp_do_8_2_transport_strike(struct sctp_cmd_seq * commands,struct sctp_association * asoc,struct sctp_transport * transport,int is_hb)563 static void sctp_do_8_2_transport_strike(struct sctp_cmd_seq *commands,
564 struct sctp_association *asoc,
565 struct sctp_transport *transport,
566 int is_hb)
567 {
568 /* The check for association's overall error counter exceeding the
569 * threshold is done in the state function.
570 */
571 /* We are here due to a timer expiration. If the timer was
572 * not a HEARTBEAT, then normal error tracking is done.
573 * If the timer was a heartbeat, we only increment error counts
574 * when we already have an outstanding HEARTBEAT that has not
575 * been acknowledged.
576 * Additionally, some tranport states inhibit error increments.
577 */
578 if (!is_hb) {
579 asoc->overall_error_count++;
580 if (transport->state != SCTP_INACTIVE)
581 transport->error_count++;
582 } else if (transport->hb_sent) {
583 if (transport->state != SCTP_UNCONFIRMED)
584 asoc->overall_error_count++;
585 if (transport->state != SCTP_INACTIVE)
586 transport->error_count++;
587 }
588
589 /* If the transport error count is greater than the pf_retrans
590 * threshold, and less than pathmaxrtx, and if the current state
591 * is SCTP_ACTIVE, then mark this transport as Partially Failed,
592 * see SCTP Quick Failover Draft, section 5.1
593 */
594 if (asoc->base.net->sctp.pf_enable &&
595 transport->state == SCTP_ACTIVE &&
596 transport->error_count < transport->pathmaxrxt &&
597 transport->error_count > transport->pf_retrans) {
598
599 sctp_assoc_control_transport(asoc, transport,
600 SCTP_TRANSPORT_PF,
601 0);
602
603 /* Update the hb timer to resend a heartbeat every rto */
604 sctp_transport_reset_hb_timer(transport);
605 }
606
607 if (transport->state != SCTP_INACTIVE &&
608 (transport->error_count > transport->pathmaxrxt)) {
609 pr_debug("%s: association:%p transport addr:%pISpc failed\n",
610 __func__, asoc, &transport->ipaddr.sa);
611
612 sctp_assoc_control_transport(asoc, transport,
613 SCTP_TRANSPORT_DOWN,
614 SCTP_FAILED_THRESHOLD);
615 }
616
617 if (transport->error_count > transport->ps_retrans &&
618 asoc->peer.primary_path == transport &&
619 asoc->peer.active_path != transport)
620 sctp_assoc_set_primary(asoc, asoc->peer.active_path);
621
622 /* E2) For the destination address for which the timer
623 * expires, set RTO <- RTO * 2 ("back off the timer"). The
624 * maximum value discussed in rule C7 above (RTO.max) may be
625 * used to provide an upper bound to this doubling operation.
626 *
627 * Special Case: the first HB doesn't trigger exponential backoff.
628 * The first unacknowledged HB triggers it. We do this with a flag
629 * that indicates that we have an outstanding HB.
630 */
631 if (!is_hb || transport->hb_sent) {
632 transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
633 sctp_max_rto(asoc, transport);
634 }
635 }
636
637 /* Worker routine to handle INIT command failure. */
sctp_cmd_init_failed(struct sctp_cmd_seq * commands,struct sctp_association * asoc,unsigned int error)638 static void sctp_cmd_init_failed(struct sctp_cmd_seq *commands,
639 struct sctp_association *asoc,
640 unsigned int error)
641 {
642 struct sctp_ulpevent *event;
643
644 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_CANT_STR_ASSOC,
645 (__u16)error, 0, 0, NULL,
646 GFP_ATOMIC);
647
648 if (event)
649 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
650 SCTP_ULPEVENT(event));
651
652 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
653 SCTP_STATE(SCTP_STATE_CLOSED));
654
655 /* SEND_FAILED sent later when cleaning up the association. */
656 asoc->outqueue.error = error;
657 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
658 }
659
660 /* 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)661 static void sctp_cmd_assoc_failed(struct sctp_cmd_seq *commands,
662 struct sctp_association *asoc,
663 enum sctp_event_type event_type,
664 union sctp_subtype subtype,
665 struct sctp_chunk *chunk,
666 unsigned int error)
667 {
668 struct sctp_ulpevent *event;
669 struct sctp_chunk *abort;
670
671 /* Cancel any partial delivery in progress. */
672 asoc->stream.si->abort_pd(&asoc->ulpq, GFP_ATOMIC);
673
674 if (event_type == SCTP_EVENT_T_CHUNK && subtype.chunk == SCTP_CID_ABORT)
675 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
676 (__u16)error, 0, 0, chunk,
677 GFP_ATOMIC);
678 else
679 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
680 (__u16)error, 0, 0, NULL,
681 GFP_ATOMIC);
682 if (event)
683 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
684 SCTP_ULPEVENT(event));
685
686 if (asoc->overall_error_count >= asoc->max_retrans) {
687 abort = sctp_make_violation_max_retrans(asoc, chunk);
688 if (abort)
689 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
690 SCTP_CHUNK(abort));
691 }
692
693 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
694 SCTP_STATE(SCTP_STATE_CLOSED));
695
696 /* SEND_FAILED sent later when cleaning up the association. */
697 asoc->outqueue.error = error;
698 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
699 }
700
701 /* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
702 * inside the cookie. In reality, this is only used for INIT-ACK processing
703 * since all other cases use "temporary" associations and can do all
704 * their work in statefuns directly.
705 */
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)706 static int sctp_cmd_process_init(struct sctp_cmd_seq *commands,
707 struct sctp_association *asoc,
708 struct sctp_chunk *chunk,
709 struct sctp_init_chunk *peer_init,
710 gfp_t gfp)
711 {
712 int error;
713
714 /* We only process the init as a sideeffect in a single
715 * case. This is when we process the INIT-ACK. If we
716 * fail during INIT processing (due to malloc problems),
717 * just return the error and stop processing the stack.
718 */
719 if (!sctp_process_init(asoc, chunk, sctp_source(chunk), peer_init, gfp))
720 error = -ENOMEM;
721 else
722 error = 0;
723
724 return error;
725 }
726
727 /* Helper function to break out starting up of heartbeat timers. */
sctp_cmd_hb_timers_start(struct sctp_cmd_seq * cmds,struct sctp_association * asoc)728 static void sctp_cmd_hb_timers_start(struct sctp_cmd_seq *cmds,
729 struct sctp_association *asoc)
730 {
731 struct sctp_transport *t;
732
733 /* Start a heartbeat timer for each transport on the association.
734 * hold a reference on the transport to make sure none of
735 * the needed data structures go away.
736 */
737 list_for_each_entry(t, &asoc->peer.transport_addr_list, transports)
738 sctp_transport_reset_hb_timer(t);
739 }
740
sctp_cmd_hb_timers_stop(struct sctp_cmd_seq * cmds,struct sctp_association * asoc)741 static void sctp_cmd_hb_timers_stop(struct sctp_cmd_seq *cmds,
742 struct sctp_association *asoc)
743 {
744 struct sctp_transport *t;
745
746 /* Stop all heartbeat timers. */
747
748 list_for_each_entry(t, &asoc->peer.transport_addr_list,
749 transports) {
750 if (timer_delete(&t->hb_timer))
751 sctp_transport_put(t);
752 }
753 }
754
755 /* Helper function to stop any pending T3-RTX timers */
sctp_cmd_t3_rtx_timers_stop(struct sctp_cmd_seq * cmds,struct sctp_association * asoc)756 static void sctp_cmd_t3_rtx_timers_stop(struct sctp_cmd_seq *cmds,
757 struct sctp_association *asoc)
758 {
759 struct sctp_transport *t;
760
761 list_for_each_entry(t, &asoc->peer.transport_addr_list,
762 transports) {
763 if (timer_delete(&t->T3_rtx_timer))
764 sctp_transport_put(t);
765 }
766 }
767
768
769 /* 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)770 static void sctp_cmd_transport_on(struct sctp_cmd_seq *cmds,
771 struct sctp_association *asoc,
772 struct sctp_transport *t,
773 struct sctp_chunk *chunk)
774 {
775 struct sctp_sender_hb_info *hbinfo;
776 int was_unconfirmed = 0;
777
778 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
779 * HEARTBEAT should clear the error counter of the destination
780 * transport address to which the HEARTBEAT was sent.
781 */
782 t->error_count = 0;
783
784 /*
785 * Although RFC4960 specifies that the overall error count must
786 * be cleared when a HEARTBEAT ACK is received, we make an
787 * exception while in SHUTDOWN PENDING. If the peer keeps its
788 * window shut forever, we may never be able to transmit our
789 * outstanding data and rely on the retransmission limit be reached
790 * to shutdown the association.
791 */
792 if (t->asoc->state < SCTP_STATE_SHUTDOWN_PENDING)
793 t->asoc->overall_error_count = 0;
794
795 /* Clear the hb_sent flag to signal that we had a good
796 * acknowledgement.
797 */
798 t->hb_sent = 0;
799
800 /* Mark the destination transport address as active if it is not so
801 * marked.
802 */
803 if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED)) {
804 was_unconfirmed = 1;
805 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
806 SCTP_HEARTBEAT_SUCCESS);
807 }
808
809 if (t->state == SCTP_PF)
810 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
811 SCTP_HEARTBEAT_SUCCESS);
812
813 /* HB-ACK was received for a the proper HB. Consider this
814 * forward progress.
815 */
816 if (t->dst)
817 sctp_transport_dst_confirm(t);
818
819 /* The receiver of the HEARTBEAT ACK should also perform an
820 * RTT measurement for that destination transport address
821 * using the time value carried in the HEARTBEAT ACK chunk.
822 * If the transport's rto_pending variable has been cleared,
823 * it was most likely due to a retransmit. However, we want
824 * to re-enable it to properly update the rto.
825 */
826 if (t->rto_pending == 0)
827 t->rto_pending = 1;
828
829 hbinfo = (struct sctp_sender_hb_info *)chunk->skb->data;
830 sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
831
832 /* Update the heartbeat timer. */
833 sctp_transport_reset_hb_timer(t);
834
835 if (was_unconfirmed && asoc->peer.transport_count == 1)
836 sctp_transport_immediate_rtx(t);
837 }
838
839
840 /* 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)841 static int sctp_cmd_process_sack(struct sctp_cmd_seq *cmds,
842 struct sctp_association *asoc,
843 struct sctp_chunk *chunk)
844 {
845 int err = 0;
846
847 if (sctp_outq_sack(&asoc->outqueue, chunk)) {
848 /* There are no more TSNs awaiting SACK. */
849 err = sctp_do_sm(asoc->base.net, SCTP_EVENT_T_OTHER,
850 SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
851 asoc->state, asoc->ep, asoc, NULL,
852 GFP_ATOMIC);
853 }
854
855 return err;
856 }
857
858 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
859 * the transport for a shutdown chunk.
860 */
sctp_cmd_setup_t2(struct sctp_cmd_seq * cmds,struct sctp_association * asoc,struct sctp_chunk * chunk)861 static void sctp_cmd_setup_t2(struct sctp_cmd_seq *cmds,
862 struct sctp_association *asoc,
863 struct sctp_chunk *chunk)
864 {
865 struct sctp_transport *t;
866
867 if (chunk->transport)
868 t = chunk->transport;
869 else {
870 t = sctp_assoc_choose_alter_transport(asoc,
871 asoc->shutdown_last_sent_to);
872 chunk->transport = t;
873 }
874 asoc->shutdown_last_sent_to = t;
875 asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
876 }
877
878 /* 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)879 static void sctp_cmd_new_state(struct sctp_cmd_seq *cmds,
880 struct sctp_association *asoc,
881 enum sctp_state state)
882 {
883 struct sock *sk = asoc->base.sk;
884
885 asoc->state = state;
886
887 pr_debug("%s: asoc:%p[%s]\n", __func__, asoc, sctp_state_tbl[state]);
888
889 if (sctp_style(sk, TCP)) {
890 /* Change the sk->sk_state of a TCP-style socket that has
891 * successfully completed a connect() call.
892 */
893 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
894 inet_sk_set_state(sk, SCTP_SS_ESTABLISHED);
895
896 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
897 if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
898 sctp_sstate(sk, ESTABLISHED)) {
899 inet_sk_set_state(sk, SCTP_SS_CLOSING);
900 sk->sk_shutdown |= RCV_SHUTDOWN;
901 }
902 }
903
904 if (sctp_state(asoc, COOKIE_WAIT)) {
905 /* Reset init timeouts since they may have been
906 * increased due to timer expirations.
907 */
908 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
909 asoc->rto_initial;
910 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
911 asoc->rto_initial;
912 }
913
914 if (sctp_state(asoc, ESTABLISHED)) {
915 kfree(asoc->peer.cookie);
916 asoc->peer.cookie = NULL;
917 }
918
919 if (sctp_state(asoc, ESTABLISHED) ||
920 sctp_state(asoc, CLOSED) ||
921 sctp_state(asoc, SHUTDOWN_RECEIVED)) {
922 /* Wake up any processes waiting in the asoc's wait queue in
923 * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
924 */
925 if (waitqueue_active(&asoc->wait))
926 wake_up_interruptible(&asoc->wait);
927
928 /* Wake up any processes waiting in the sk's sleep queue of
929 * a TCP-style or UDP-style peeled-off socket in
930 * sctp_wait_for_accept() or sctp_wait_for_packet().
931 * For a UDP-style socket, the waiters are woken up by the
932 * notifications.
933 */
934 if (!sctp_style(sk, UDP))
935 sk->sk_state_change(sk);
936 }
937
938 if (sctp_state(asoc, SHUTDOWN_PENDING) &&
939 !sctp_outq_is_empty(&asoc->outqueue))
940 sctp_outq_uncork(&asoc->outqueue, GFP_ATOMIC);
941 }
942
943 /* Helper function to delete an association. */
sctp_cmd_delete_tcb(struct sctp_cmd_seq * cmds,struct sctp_association * asoc)944 static void sctp_cmd_delete_tcb(struct sctp_cmd_seq *cmds,
945 struct sctp_association *asoc)
946 {
947 struct sock *sk = asoc->base.sk;
948
949 /* If it is a non-temporary association belonging to a TCP-style
950 * listening socket that is not closed, do not free it so that accept()
951 * can pick it up later.
952 */
953 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
954 (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
955 return;
956
957 sctp_association_free(asoc);
958 }
959
960 /*
961 * ADDIP Section 4.1 ASCONF Chunk Procedures
962 * A4) Start a T-4 RTO timer, using the RTO value of the selected
963 * destination address (we use active path instead of primary path just
964 * because primary path may be inactive.
965 */
sctp_cmd_setup_t4(struct sctp_cmd_seq * cmds,struct sctp_association * asoc,struct sctp_chunk * chunk)966 static void sctp_cmd_setup_t4(struct sctp_cmd_seq *cmds,
967 struct sctp_association *asoc,
968 struct sctp_chunk *chunk)
969 {
970 struct sctp_transport *t;
971
972 t = sctp_assoc_choose_alter_transport(asoc, chunk->transport);
973 asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
974 chunk->transport = t;
975 }
976
977 /* Process an incoming Operation Error Chunk. */
sctp_cmd_process_operr(struct sctp_cmd_seq * cmds,struct sctp_association * asoc,struct sctp_chunk * chunk)978 static void sctp_cmd_process_operr(struct sctp_cmd_seq *cmds,
979 struct sctp_association *asoc,
980 struct sctp_chunk *chunk)
981 {
982 struct sctp_errhdr *err_hdr;
983 struct sctp_ulpevent *ev;
984
985 while (chunk->chunk_end > chunk->skb->data) {
986 err_hdr = (struct sctp_errhdr *)(chunk->skb->data);
987
988 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
989 GFP_ATOMIC);
990 if (!ev)
991 return;
992
993 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
994
995 switch (err_hdr->cause) {
996 case SCTP_ERROR_UNKNOWN_CHUNK:
997 {
998 struct sctp_chunkhdr *unk_chunk_hdr;
999
1000 unk_chunk_hdr = (struct sctp_chunkhdr *)(err_hdr + 1);
1001 switch (unk_chunk_hdr->type) {
1002 /* ADDIP 4.1 A9) If the peer responds to an ASCONF with
1003 * an ERROR chunk reporting that it did not recognized
1004 * the ASCONF chunk type, the sender of the ASCONF MUST
1005 * NOT send any further ASCONF chunks and MUST stop its
1006 * T-4 timer.
1007 */
1008 case SCTP_CID_ASCONF:
1009 if (asoc->peer.asconf_capable == 0)
1010 break;
1011
1012 asoc->peer.asconf_capable = 0;
1013 sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
1014 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
1015 break;
1016 default:
1017 break;
1018 }
1019 break;
1020 }
1021 default:
1022 break;
1023 }
1024 }
1025 }
1026
1027 /* Helper function to remove the association non-primary peer
1028 * transports.
1029 */
sctp_cmd_del_non_primary(struct sctp_association * asoc)1030 static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
1031 {
1032 struct sctp_transport *t;
1033 struct list_head *temp;
1034 struct list_head *pos;
1035
1036 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
1037 t = list_entry(pos, struct sctp_transport, transports);
1038 if (!sctp_cmp_addr_exact(&t->ipaddr,
1039 &asoc->peer.primary_addr)) {
1040 sctp_assoc_rm_peer(asoc, t);
1041 }
1042 }
1043 }
1044
1045 /* Helper function to set sk_err on a 1-1 style socket. */
sctp_cmd_set_sk_err(struct sctp_association * asoc,int error)1046 static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
1047 {
1048 struct sock *sk = asoc->base.sk;
1049
1050 if (!sctp_style(sk, UDP))
1051 sk->sk_err = error;
1052 }
1053
1054 /* Helper function to generate an association change event */
sctp_cmd_assoc_change(struct sctp_cmd_seq * commands,struct sctp_association * asoc,u8 state)1055 static void sctp_cmd_assoc_change(struct sctp_cmd_seq *commands,
1056 struct sctp_association *asoc,
1057 u8 state)
1058 {
1059 struct sctp_ulpevent *ev;
1060
1061 ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0,
1062 asoc->c.sinit_num_ostreams,
1063 asoc->c.sinit_max_instreams,
1064 NULL, GFP_ATOMIC);
1065 if (ev)
1066 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
1067 }
1068
sctp_cmd_peer_no_auth(struct sctp_cmd_seq * commands,struct sctp_association * asoc)1069 static void sctp_cmd_peer_no_auth(struct sctp_cmd_seq *commands,
1070 struct sctp_association *asoc)
1071 {
1072 struct sctp_ulpevent *ev;
1073
1074 ev = sctp_ulpevent_make_authkey(asoc, 0, SCTP_AUTH_NO_AUTH, GFP_ATOMIC);
1075 if (ev)
1076 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
1077 }
1078
1079 /* Helper function to generate an adaptation indication event */
sctp_cmd_adaptation_ind(struct sctp_cmd_seq * commands,struct sctp_association * asoc)1080 static void sctp_cmd_adaptation_ind(struct sctp_cmd_seq *commands,
1081 struct sctp_association *asoc)
1082 {
1083 struct sctp_ulpevent *ev;
1084
1085 ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
1086
1087 if (ev)
1088 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
1089 }
1090
1091
sctp_cmd_t1_timer_update(struct sctp_association * asoc,enum sctp_event_timeout timer,char * name)1092 static void sctp_cmd_t1_timer_update(struct sctp_association *asoc,
1093 enum sctp_event_timeout timer,
1094 char *name)
1095 {
1096 struct sctp_transport *t;
1097
1098 t = asoc->init_last_sent_to;
1099 asoc->init_err_counter++;
1100
1101 if (t->init_sent_count > (asoc->init_cycle + 1)) {
1102 asoc->timeouts[timer] *= 2;
1103 if (asoc->timeouts[timer] > asoc->max_init_timeo) {
1104 asoc->timeouts[timer] = asoc->max_init_timeo;
1105 }
1106 asoc->init_cycle++;
1107
1108 pr_debug("%s: T1[%s] timeout adjustment init_err_counter:%d"
1109 " cycle:%d timeout:%ld\n", __func__, name,
1110 asoc->init_err_counter, asoc->init_cycle,
1111 asoc->timeouts[timer]);
1112 }
1113
1114 }
1115
1116 /* Send the whole message, chunk by chunk, to the outqueue.
1117 * This way the whole message is queued up and bundling if
1118 * encouraged for small fragments.
1119 */
sctp_cmd_send_msg(struct sctp_association * asoc,struct sctp_datamsg * msg,gfp_t gfp)1120 static void sctp_cmd_send_msg(struct sctp_association *asoc,
1121 struct sctp_datamsg *msg, gfp_t gfp)
1122 {
1123 struct sctp_chunk *chunk;
1124
1125 list_for_each_entry(chunk, &msg->chunks, frag_list)
1126 sctp_outq_tail(&asoc->outqueue, chunk, gfp);
1127
1128 asoc->outqueue.sched->enqueue(&asoc->outqueue, msg);
1129 }
1130
1131
1132 /* These three macros allow us to pull the debugging code out of the
1133 * main flow of sctp_do_sm() to keep attention focused on the real
1134 * functionality there.
1135 */
1136 #define debug_pre_sfn() \
1137 pr_debug("%s[pre-fn]: ep:%p, %s, %s, asoc:%p[%s], %s\n", __func__, \
1138 ep, sctp_evttype_tbl[event_type], (*debug_fn)(subtype), \
1139 asoc, sctp_state_tbl[state], state_fn->name)
1140
1141 #define debug_post_sfn() \
1142 pr_debug("%s[post-fn]: asoc:%p, status:%s\n", __func__, asoc, \
1143 sctp_status_tbl[status])
1144
1145 #define debug_post_sfx() \
1146 pr_debug("%s[post-sfx]: error:%d, asoc:%p[%s]\n", __func__, error, \
1147 asoc, sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
1148 sctp_assoc2id(asoc))) ? asoc->state : SCTP_STATE_CLOSED])
1149
1150 /*
1151 * This is the master state machine processing function.
1152 *
1153 * If you want to understand all of lksctp, this is a
1154 * good place to start.
1155 */
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)1156 int sctp_do_sm(struct net *net, enum sctp_event_type event_type,
1157 union sctp_subtype subtype, enum sctp_state state,
1158 struct sctp_endpoint *ep, struct sctp_association *asoc,
1159 void *event_arg, gfp_t gfp)
1160 {
1161 typedef const char *(printfn_t)(union sctp_subtype);
1162 static printfn_t *table[] = {
1163 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
1164 };
1165 printfn_t *debug_fn __attribute__ ((unused)) = table[event_type];
1166 const struct sctp_sm_table_entry *state_fn;
1167 struct sctp_cmd_seq commands;
1168 enum sctp_disposition status;
1169 int error = 0;
1170
1171 /* Look up the state function, run it, and then process the
1172 * side effects. These three steps are the heart of lksctp.
1173 */
1174 state_fn = sctp_sm_lookup_event(net, event_type, state, subtype);
1175
1176 sctp_init_cmd_seq(&commands);
1177
1178 debug_pre_sfn();
1179 status = state_fn->fn(net, ep, asoc, subtype, event_arg, &commands);
1180 debug_post_sfn();
1181
1182 error = sctp_side_effects(event_type, subtype, state,
1183 ep, &asoc, event_arg, status,
1184 &commands, gfp);
1185 debug_post_sfx();
1186
1187 return error;
1188 }
1189
1190 /*****************************************************************
1191 * This the master state function side effect processing function.
1192 *****************************************************************/
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)1193 static int sctp_side_effects(enum sctp_event_type event_type,
1194 union sctp_subtype subtype,
1195 enum sctp_state state,
1196 struct sctp_endpoint *ep,
1197 struct sctp_association **asoc,
1198 void *event_arg,
1199 enum sctp_disposition status,
1200 struct sctp_cmd_seq *commands,
1201 gfp_t gfp)
1202 {
1203 int error;
1204
1205 /* FIXME - Most of the dispositions left today would be categorized
1206 * as "exceptional" dispositions. For those dispositions, it
1207 * may not be proper to run through any of the commands at all.
1208 * For example, the command interpreter might be run only with
1209 * disposition SCTP_DISPOSITION_CONSUME.
1210 */
1211 if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
1212 ep, *asoc,
1213 event_arg, status,
1214 commands, gfp)))
1215 goto bail;
1216
1217 switch (status) {
1218 case SCTP_DISPOSITION_DISCARD:
1219 pr_debug("%s: ignored sctp protocol event - state:%d, "
1220 "event_type:%d, event_id:%d\n", __func__, state,
1221 event_type, subtype.chunk);
1222 break;
1223
1224 case SCTP_DISPOSITION_NOMEM:
1225 /* We ran out of memory, so we need to discard this
1226 * packet.
1227 */
1228 /* BUG--we should now recover some memory, probably by
1229 * reneging...
1230 */
1231 error = -ENOMEM;
1232 break;
1233
1234 case SCTP_DISPOSITION_DELETE_TCB:
1235 case SCTP_DISPOSITION_ABORT:
1236 /* This should now be a command. */
1237 *asoc = NULL;
1238 break;
1239
1240 case SCTP_DISPOSITION_CONSUME:
1241 /*
1242 * We should no longer have much work to do here as the
1243 * real work has been done as explicit commands above.
1244 */
1245 break;
1246
1247 case SCTP_DISPOSITION_VIOLATION:
1248 net_err_ratelimited("protocol violation state %d chunkid %d\n",
1249 state, subtype.chunk);
1250 break;
1251
1252 case SCTP_DISPOSITION_NOT_IMPL:
1253 pr_warn("unimplemented feature in state %d, event_type %d, event_id %d\n",
1254 state, event_type, subtype.chunk);
1255 break;
1256
1257 case SCTP_DISPOSITION_BUG:
1258 pr_err("bug in state %d, event_type %d, event_id %d\n",
1259 state, event_type, subtype.chunk);
1260 BUG();
1261 break;
1262
1263 default:
1264 pr_err("impossible disposition %d in state %d, event_type %d, event_id %d\n",
1265 status, state, event_type, subtype.chunk);
1266 error = status;
1267 if (error >= 0)
1268 error = -EINVAL;
1269 WARN_ON_ONCE(1);
1270 break;
1271 }
1272
1273 bail:
1274 return error;
1275 }
1276
1277 /********************************************************************
1278 * 2nd Level Abstractions
1279 ********************************************************************/
1280
1281 /* 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)1282 static int sctp_cmd_interpreter(enum sctp_event_type event_type,
1283 union sctp_subtype subtype,
1284 enum sctp_state state,
1285 struct sctp_endpoint *ep,
1286 struct sctp_association *asoc,
1287 void *event_arg,
1288 enum sctp_disposition status,
1289 struct sctp_cmd_seq *commands,
1290 gfp_t gfp)
1291 {
1292 struct sctp_sock *sp = sctp_sk(ep->base.sk);
1293 struct sctp_chunk *chunk = NULL, *new_obj;
1294 struct sctp_packet *packet;
1295 struct sctp_sackhdr sackh;
1296 struct timer_list *timer;
1297 struct sctp_transport *t;
1298 unsigned long timeout;
1299 struct sctp_cmd *cmd;
1300 int local_cork = 0;
1301 int error = 0;
1302 int force;
1303
1304 if (SCTP_EVENT_T_TIMEOUT != event_type)
1305 chunk = event_arg;
1306
1307 /* Note: This whole file is a huge candidate for rework.
1308 * For example, each command could either have its own handler, so
1309 * the loop would look like:
1310 * while (cmds)
1311 * cmd->handle(x, y, z)
1312 * --jgrimm
1313 */
1314 while (NULL != (cmd = sctp_next_cmd(commands))) {
1315 switch (cmd->verb) {
1316 case SCTP_CMD_NOP:
1317 /* Do nothing. */
1318 break;
1319
1320 case SCTP_CMD_NEW_ASOC:
1321 /* Register a new association. */
1322 if (local_cork) {
1323 sctp_outq_uncork(&asoc->outqueue, gfp);
1324 local_cork = 0;
1325 }
1326
1327 /* Register with the endpoint. */
1328 asoc = cmd->obj.asoc;
1329 BUG_ON(asoc->peer.primary_path == NULL);
1330 sctp_endpoint_add_asoc(ep, asoc);
1331 break;
1332
1333 case SCTP_CMD_PURGE_OUTQUEUE:
1334 sctp_outq_teardown(&asoc->outqueue);
1335 break;
1336
1337 case SCTP_CMD_DELETE_TCB:
1338 if (local_cork) {
1339 sctp_outq_uncork(&asoc->outqueue, gfp);
1340 local_cork = 0;
1341 }
1342 /* No chunk left in this packet may use this asoc. */
1343 if (event_type == SCTP_EVENT_T_CHUNK &&
1344 chunk->asoc == asoc)
1345 chunk->pdiscard = 1;
1346 /* Delete the current association. */
1347 sctp_cmd_delete_tcb(commands, asoc);
1348 asoc = NULL;
1349 break;
1350
1351 case SCTP_CMD_NEW_STATE:
1352 /* Enter a new state. */
1353 sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1354 break;
1355
1356 case SCTP_CMD_REPORT_TSN:
1357 /* Record the arrival of a TSN. */
1358 error = sctp_tsnmap_mark(&asoc->peer.tsn_map,
1359 cmd->obj.u32, NULL);
1360 break;
1361
1362 case SCTP_CMD_REPORT_FWDTSN:
1363 asoc->stream.si->report_ftsn(&asoc->ulpq, cmd->obj.u32);
1364 break;
1365
1366 case SCTP_CMD_PROCESS_FWDTSN:
1367 asoc->stream.si->handle_ftsn(&asoc->ulpq,
1368 cmd->obj.chunk);
1369 break;
1370
1371 case SCTP_CMD_GEN_SACK:
1372 /* Generate a Selective ACK.
1373 * The argument tells us whether to just count
1374 * the packet and MAYBE generate a SACK, or
1375 * force a SACK out.
1376 */
1377 force = cmd->obj.i32;
1378 error = sctp_gen_sack(asoc, force, commands);
1379 break;
1380
1381 case SCTP_CMD_PROCESS_SACK:
1382 /* Process an inbound SACK. */
1383 error = sctp_cmd_process_sack(commands, asoc,
1384 cmd->obj.chunk);
1385 break;
1386
1387 case SCTP_CMD_GEN_INIT_ACK:
1388 /* Generate an INIT ACK chunk. */
1389 new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1390 0);
1391 if (!new_obj) {
1392 error = -ENOMEM;
1393 break;
1394 }
1395
1396 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1397 SCTP_CHUNK(new_obj));
1398 break;
1399
1400 case SCTP_CMD_PEER_INIT:
1401 /* Process a unified INIT from the peer.
1402 * Note: Only used during INIT-ACK processing. If
1403 * there is an error just return to the outter
1404 * layer which will bail.
1405 */
1406 error = sctp_cmd_process_init(commands, asoc, chunk,
1407 cmd->obj.init, gfp);
1408 break;
1409
1410 case SCTP_CMD_GEN_COOKIE_ECHO:
1411 /* Generate a COOKIE ECHO chunk. */
1412 new_obj = sctp_make_cookie_echo(asoc, chunk);
1413 if (!new_obj) {
1414 if (cmd->obj.chunk)
1415 sctp_chunk_free(cmd->obj.chunk);
1416 error = -ENOMEM;
1417 break;
1418 }
1419 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1420 SCTP_CHUNK(new_obj));
1421
1422 /* If there is an ERROR chunk to be sent along with
1423 * the COOKIE_ECHO, send it, too.
1424 */
1425 if (cmd->obj.chunk)
1426 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1427 SCTP_CHUNK(cmd->obj.chunk));
1428
1429 if (new_obj->transport) {
1430 new_obj->transport->init_sent_count++;
1431 asoc->init_last_sent_to = new_obj->transport;
1432 }
1433
1434 /* FIXME - Eventually come up with a cleaner way to
1435 * enabling COOKIE-ECHO + DATA bundling during
1436 * multihoming stale cookie scenarios, the following
1437 * command plays with asoc->peer.retran_path to
1438 * avoid the problem of sending the COOKIE-ECHO and
1439 * DATA in different paths, which could result
1440 * in the association being ABORTed if the DATA chunk
1441 * is processed first by the server. Checking the
1442 * init error counter simply causes this command
1443 * to be executed only during failed attempts of
1444 * association establishment.
1445 */
1446 if ((asoc->peer.retran_path !=
1447 asoc->peer.primary_path) &&
1448 (asoc->init_err_counter > 0)) {
1449 sctp_add_cmd_sf(commands,
1450 SCTP_CMD_FORCE_PRIM_RETRAN,
1451 SCTP_NULL());
1452 }
1453
1454 break;
1455
1456 case SCTP_CMD_GEN_SHUTDOWN:
1457 /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1458 * Reset error counts.
1459 */
1460 asoc->overall_error_count = 0;
1461
1462 /* Generate a SHUTDOWN chunk. */
1463 new_obj = sctp_make_shutdown(asoc, chunk);
1464 if (!new_obj) {
1465 error = -ENOMEM;
1466 break;
1467 }
1468 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1469 SCTP_CHUNK(new_obj));
1470 break;
1471
1472 case SCTP_CMD_CHUNK_ULP:
1473 /* Send a chunk to the sockets layer. */
1474 pr_debug("%s: sm_sideff: chunk_up:%p, ulpq:%p\n",
1475 __func__, cmd->obj.chunk, &asoc->ulpq);
1476
1477 asoc->stream.si->ulpevent_data(&asoc->ulpq,
1478 cmd->obj.chunk,
1479 GFP_ATOMIC);
1480 break;
1481
1482 case SCTP_CMD_EVENT_ULP:
1483 /* Send a notification to the sockets layer. */
1484 pr_debug("%s: sm_sideff: event_up:%p, ulpq:%p\n",
1485 __func__, cmd->obj.ulpevent, &asoc->ulpq);
1486
1487 asoc->stream.si->enqueue_event(&asoc->ulpq,
1488 cmd->obj.ulpevent);
1489 break;
1490
1491 case SCTP_CMD_REPLY:
1492 /* If an caller has not already corked, do cork. */
1493 if (!asoc->outqueue.cork) {
1494 sctp_outq_cork(&asoc->outqueue);
1495 local_cork = 1;
1496 }
1497 /* Send a chunk to our peer. */
1498 sctp_outq_tail(&asoc->outqueue, cmd->obj.chunk, gfp);
1499 break;
1500
1501 case SCTP_CMD_SEND_PKT:
1502 /* Send a full packet to our peer. */
1503 packet = cmd->obj.packet;
1504 sctp_packet_transmit(packet, gfp);
1505 sctp_ootb_pkt_free(packet);
1506 break;
1507
1508 case SCTP_CMD_T1_RETRAN:
1509 /* Mark a transport for retransmission. */
1510 sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1511 SCTP_RTXR_T1_RTX);
1512 break;
1513
1514 case SCTP_CMD_RETRAN:
1515 /* Mark a transport for retransmission. */
1516 sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1517 SCTP_RTXR_T3_RTX);
1518 break;
1519
1520 case SCTP_CMD_ECN_CE:
1521 /* Do delayed CE processing. */
1522 sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1523 break;
1524
1525 case SCTP_CMD_ECN_ECNE:
1526 /* Do delayed ECNE processing. */
1527 new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1528 chunk);
1529 if (new_obj)
1530 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1531 SCTP_CHUNK(new_obj));
1532 break;
1533
1534 case SCTP_CMD_ECN_CWR:
1535 /* Do delayed CWR processing. */
1536 sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1537 break;
1538
1539 case SCTP_CMD_SETUP_T2:
1540 sctp_cmd_setup_t2(commands, asoc, cmd->obj.chunk);
1541 break;
1542
1543 case SCTP_CMD_TIMER_START_ONCE:
1544 timer = &asoc->timers[cmd->obj.to];
1545
1546 if (timer_pending(timer))
1547 break;
1548 fallthrough;
1549
1550 case SCTP_CMD_TIMER_START:
1551 timer = &asoc->timers[cmd->obj.to];
1552 timeout = asoc->timeouts[cmd->obj.to];
1553 BUG_ON(!timeout);
1554
1555 if (!timer_reduce(timer, jiffies + timeout))
1556 sctp_association_hold(asoc);
1557 break;
1558
1559 case SCTP_CMD_TIMER_RESTART:
1560 timer = &asoc->timers[cmd->obj.to];
1561 timeout = asoc->timeouts[cmd->obj.to];
1562 if (!mod_timer(timer, jiffies + timeout))
1563 sctp_association_hold(asoc);
1564 break;
1565
1566 case SCTP_CMD_TIMER_STOP:
1567 timer = &asoc->timers[cmd->obj.to];
1568 if (timer_delete(timer))
1569 sctp_association_put(asoc);
1570 break;
1571
1572 case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1573 chunk = cmd->obj.chunk;
1574 t = sctp_assoc_choose_alter_transport(asoc,
1575 asoc->init_last_sent_to);
1576 asoc->init_last_sent_to = t;
1577 chunk->transport = t;
1578 t->init_sent_count++;
1579 /* Set the new transport as primary */
1580 sctp_assoc_set_primary(asoc, t);
1581 break;
1582
1583 case SCTP_CMD_INIT_RESTART:
1584 /* Do the needed accounting and updates
1585 * associated with restarting an initialization
1586 * timer. Only multiply the timeout by two if
1587 * all transports have been tried at the current
1588 * timeout.
1589 */
1590 sctp_cmd_t1_timer_update(asoc,
1591 SCTP_EVENT_TIMEOUT_T1_INIT,
1592 "INIT");
1593
1594 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1595 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1596 break;
1597
1598 case SCTP_CMD_COOKIEECHO_RESTART:
1599 /* Do the needed accounting and updates
1600 * associated with restarting an initialization
1601 * timer. Only multiply the timeout by two if
1602 * all transports have been tried at the current
1603 * timeout.
1604 */
1605 sctp_cmd_t1_timer_update(asoc,
1606 SCTP_EVENT_TIMEOUT_T1_COOKIE,
1607 "COOKIE");
1608
1609 /* If we've sent any data bundled with
1610 * COOKIE-ECHO we need to resend.
1611 */
1612 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1613 transports) {
1614 sctp_retransmit_mark(&asoc->outqueue, t,
1615 SCTP_RTXR_T1_RTX);
1616 }
1617
1618 sctp_add_cmd_sf(commands,
1619 SCTP_CMD_TIMER_RESTART,
1620 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1621 break;
1622
1623 case SCTP_CMD_INIT_FAILED:
1624 sctp_cmd_init_failed(commands, asoc, cmd->obj.u16);
1625 break;
1626
1627 case SCTP_CMD_ASSOC_FAILED:
1628 sctp_cmd_assoc_failed(commands, asoc, event_type,
1629 subtype, chunk, cmd->obj.u16);
1630 break;
1631
1632 case SCTP_CMD_INIT_COUNTER_INC:
1633 asoc->init_err_counter++;
1634 break;
1635
1636 case SCTP_CMD_INIT_COUNTER_RESET:
1637 asoc->init_err_counter = 0;
1638 asoc->init_cycle = 0;
1639 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1640 transports) {
1641 t->init_sent_count = 0;
1642 }
1643 break;
1644
1645 case SCTP_CMD_REPORT_DUP:
1646 sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1647 cmd->obj.u32);
1648 break;
1649
1650 case SCTP_CMD_REPORT_BAD_TAG:
1651 pr_debug("%s: vtag mismatch!\n", __func__);
1652 break;
1653
1654 case SCTP_CMD_STRIKE:
1655 /* Mark one strike against a transport. */
1656 sctp_do_8_2_transport_strike(commands, asoc,
1657 cmd->obj.transport, 0);
1658 break;
1659
1660 case SCTP_CMD_TRANSPORT_IDLE:
1661 t = cmd->obj.transport;
1662 sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
1663 break;
1664
1665 case SCTP_CMD_TRANSPORT_HB_SENT:
1666 t = cmd->obj.transport;
1667 sctp_do_8_2_transport_strike(commands, asoc,
1668 t, 1);
1669 t->hb_sent = 1;
1670 break;
1671
1672 case SCTP_CMD_TRANSPORT_ON:
1673 t = cmd->obj.transport;
1674 sctp_cmd_transport_on(commands, asoc, t, chunk);
1675 break;
1676
1677 case SCTP_CMD_HB_TIMERS_START:
1678 sctp_cmd_hb_timers_start(commands, asoc);
1679 break;
1680
1681 case SCTP_CMD_HB_TIMER_UPDATE:
1682 t = cmd->obj.transport;
1683 sctp_transport_reset_hb_timer(t);
1684 break;
1685
1686 case SCTP_CMD_HB_TIMERS_STOP:
1687 sctp_cmd_hb_timers_stop(commands, asoc);
1688 break;
1689
1690 case SCTP_CMD_PROBE_TIMER_UPDATE:
1691 t = cmd->obj.transport;
1692 sctp_transport_reset_probe_timer(t);
1693 break;
1694
1695 case SCTP_CMD_REPORT_ERROR:
1696 error = cmd->obj.error;
1697 break;
1698
1699 case SCTP_CMD_PROCESS_CTSN:
1700 /* Dummy up a SACK for processing. */
1701 sackh.cum_tsn_ack = cmd->obj.be32;
1702 sackh.a_rwnd = htonl(asoc->peer.rwnd +
1703 asoc->outqueue.outstanding_bytes);
1704 sackh.num_gap_ack_blocks = 0;
1705 sackh.num_dup_tsns = 0;
1706 chunk->subh.sack_hdr = &sackh;
1707 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1708 SCTP_CHUNK(chunk));
1709 break;
1710
1711 case SCTP_CMD_DISCARD_PACKET:
1712 /* We need to discard the whole packet.
1713 * Uncork the queue since there might be
1714 * responses pending
1715 */
1716 chunk->pdiscard = 1;
1717 if (asoc) {
1718 sctp_outq_uncork(&asoc->outqueue, gfp);
1719 local_cork = 0;
1720 }
1721 break;
1722
1723 case SCTP_CMD_RTO_PENDING:
1724 t = cmd->obj.transport;
1725 t->rto_pending = 1;
1726 break;
1727
1728 case SCTP_CMD_PART_DELIVER:
1729 asoc->stream.si->start_pd(&asoc->ulpq, GFP_ATOMIC);
1730 break;
1731
1732 case SCTP_CMD_RENEGE:
1733 asoc->stream.si->renege_events(&asoc->ulpq,
1734 cmd->obj.chunk,
1735 GFP_ATOMIC);
1736 break;
1737
1738 case SCTP_CMD_SETUP_T4:
1739 sctp_cmd_setup_t4(commands, asoc, cmd->obj.chunk);
1740 break;
1741
1742 case SCTP_CMD_PROCESS_OPERR:
1743 sctp_cmd_process_operr(commands, asoc, chunk);
1744 break;
1745 case SCTP_CMD_CLEAR_INIT_TAG:
1746 asoc->peer.i.init_tag = 0;
1747 break;
1748 case SCTP_CMD_DEL_NON_PRIMARY:
1749 sctp_cmd_del_non_primary(asoc);
1750 break;
1751 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1752 sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1753 break;
1754 case SCTP_CMD_FORCE_PRIM_RETRAN:
1755 t = asoc->peer.retran_path;
1756 asoc->peer.retran_path = asoc->peer.primary_path;
1757 sctp_outq_uncork(&asoc->outqueue, gfp);
1758 local_cork = 0;
1759 asoc->peer.retran_path = t;
1760 break;
1761 case SCTP_CMD_SET_SK_ERR:
1762 sctp_cmd_set_sk_err(asoc, cmd->obj.error);
1763 break;
1764 case SCTP_CMD_ASSOC_CHANGE:
1765 sctp_cmd_assoc_change(commands, asoc,
1766 cmd->obj.u8);
1767 break;
1768 case SCTP_CMD_ADAPTATION_IND:
1769 sctp_cmd_adaptation_ind(commands, asoc);
1770 break;
1771 case SCTP_CMD_PEER_NO_AUTH:
1772 sctp_cmd_peer_no_auth(commands, asoc);
1773 break;
1774
1775 case SCTP_CMD_ASSOC_SHKEY:
1776 error = sctp_auth_asoc_init_active_key(asoc,
1777 GFP_ATOMIC);
1778 break;
1779 case SCTP_CMD_UPDATE_INITTAG:
1780 asoc->peer.i.init_tag = cmd->obj.u32;
1781 break;
1782 case SCTP_CMD_SEND_MSG:
1783 if (!asoc->outqueue.cork) {
1784 sctp_outq_cork(&asoc->outqueue);
1785 local_cork = 1;
1786 }
1787 sctp_cmd_send_msg(asoc, cmd->obj.msg, gfp);
1788 break;
1789 case SCTP_CMD_PURGE_ASCONF_QUEUE:
1790 sctp_asconf_queue_teardown(asoc);
1791 break;
1792
1793 case SCTP_CMD_SET_ASOC:
1794 if (asoc && local_cork) {
1795 sctp_outq_uncork(&asoc->outqueue, gfp);
1796 local_cork = 0;
1797 }
1798 asoc = cmd->obj.asoc;
1799 break;
1800
1801 default:
1802 pr_warn("Impossible command: %u\n",
1803 cmd->verb);
1804 break;
1805 }
1806
1807 if (error) {
1808 cmd = sctp_next_cmd(commands);
1809 while (cmd) {
1810 if (cmd->verb == SCTP_CMD_REPLY)
1811 sctp_chunk_free(cmd->obj.chunk);
1812 cmd = sctp_next_cmd(commands);
1813 }
1814 break;
1815 }
1816 }
1817
1818 /* If this is in response to a received chunk, wait until
1819 * we are done with the packet to open the queue so that we don't
1820 * send multiple packets in response to a single request.
1821 */
1822 if (asoc && SCTP_EVENT_T_CHUNK == event_type && chunk) {
1823 if (chunk->end_of_packet || chunk->singleton)
1824 sctp_outq_uncork(&asoc->outqueue, gfp);
1825 } else if (local_cork)
1826 sctp_outq_uncork(&asoc->outqueue, gfp);
1827
1828 if (sp->data_ready_signalled)
1829 sp->data_ready_signalled = 0;
1830
1831 return error;
1832 }
1833