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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
40static 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);
49static 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. */
64static 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 */
85static 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. */
128static 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. */
138static 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;
223nomem:
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 */
231void 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
262out_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 */
270static 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
303out_unlock:
304 bh_unlock_sock(sk);
305 sctp_association_put(asoc);
306}
307
308static 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
316static 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
324static 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
332static 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
340static 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
351static 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 */
362void 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
399out_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 */
407void 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
436out_unlock:
437 bh_unlock_sock(sk);
438 sctp_transport_put(transport);
439}
440
441 /* Handle the timeout of the RE-CONFIG timer. */
442void 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
473out_unlock:
474 bh_unlock_sock(sk);
475 sctp_transport_put(transport);
476}
477
478/* Handle the timeout of the probe timer. */
479void 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
505out_unlock:
506 bh_unlock_sock(sk);
507 sctp_transport_put(transport);
508}
509
510/* Inject a SACK Timeout event into the state machine. */
511static 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
519sctp_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 */
550static 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. */
625static 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. */
648static 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 */
693static 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. */
715static 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
728static 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 */
743static 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. */
757static 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. */
828static 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 */
848static 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. */
866static 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. */
931static 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 */
953static 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. */
965static 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 *)(err_hdr + 1);
988 switch (unk_chunk_hdr->type) {
989 /* ADDIP 4.1 A9) If the peer responds to an ASCONF with
990 * an ERROR chunk reporting that it did not recognized
991 * the ASCONF chunk type, the sender of the ASCONF MUST
992 * NOT send any further ASCONF chunks and MUST stop its
993 * T-4 timer.
994 */
995 case SCTP_CID_ASCONF:
996 if (asoc->peer.asconf_capable == 0)
997 break;
998
999 asoc->peer.asconf_capable = 0;
1000 sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
1001 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
1002 break;
1003 default:
1004 break;
1005 }
1006 break;
1007 }
1008 default:
1009 break;
1010 }
1011 }
1012}
1013
1014/* Helper function to remove the association non-primary peer
1015 * transports.
1016 */
1017static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
1018{
1019 struct sctp_transport *t;
1020 struct list_head *temp;
1021 struct list_head *pos;
1022
1023 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
1024 t = list_entry(pos, struct sctp_transport, transports);
1025 if (!sctp_cmp_addr_exact(&t->ipaddr,
1026 &asoc->peer.primary_addr)) {
1027 sctp_assoc_rm_peer(asoc, t);
1028 }
1029 }
1030}
1031
1032/* Helper function to set sk_err on a 1-1 style socket. */
1033static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
1034{
1035 struct sock *sk = asoc->base.sk;
1036
1037 if (!sctp_style(sk, UDP))
1038 sk->sk_err = error;
1039}
1040
1041/* Helper function to generate an association change event */
1042static void sctp_cmd_assoc_change(struct sctp_cmd_seq *commands,
1043 struct sctp_association *asoc,
1044 u8 state)
1045{
1046 struct sctp_ulpevent *ev;
1047
1048 ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0,
1049 asoc->c.sinit_num_ostreams,
1050 asoc->c.sinit_max_instreams,
1051 NULL, GFP_ATOMIC);
1052 if (ev)
1053 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
1054}
1055
1056static void sctp_cmd_peer_no_auth(struct sctp_cmd_seq *commands,
1057 struct sctp_association *asoc)
1058{
1059 struct sctp_ulpevent *ev;
1060
1061 ev = sctp_ulpevent_make_authkey(asoc, 0, SCTP_AUTH_NO_AUTH, GFP_ATOMIC);
1062 if (ev)
1063 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
1064}
1065
1066/* Helper function to generate an adaptation indication event */
1067static void sctp_cmd_adaptation_ind(struct sctp_cmd_seq *commands,
1068 struct sctp_association *asoc)
1069{
1070 struct sctp_ulpevent *ev;
1071
1072 ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
1073
1074 if (ev)
1075 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
1076}
1077
1078
1079static void sctp_cmd_t1_timer_update(struct sctp_association *asoc,
1080 enum sctp_event_timeout timer,
1081 char *name)
1082{
1083 struct sctp_transport *t;
1084
1085 t = asoc->init_last_sent_to;
1086 asoc->init_err_counter++;
1087
1088 if (t->init_sent_count > (asoc->init_cycle + 1)) {
1089 asoc->timeouts[timer] *= 2;
1090 if (asoc->timeouts[timer] > asoc->max_init_timeo) {
1091 asoc->timeouts[timer] = asoc->max_init_timeo;
1092 }
1093 asoc->init_cycle++;
1094
1095 pr_debug("%s: T1[%s] timeout adjustment init_err_counter:%d"
1096 " cycle:%d timeout:%ld\n", __func__, name,
1097 asoc->init_err_counter, asoc->init_cycle,
1098 asoc->timeouts[timer]);
1099 }
1100
1101}
1102
1103/* Send the whole message, chunk by chunk, to the outqueue.
1104 * This way the whole message is queued up and bundling if
1105 * encouraged for small fragments.
1106 */
1107static void sctp_cmd_send_msg(struct sctp_association *asoc,
1108 struct sctp_datamsg *msg, gfp_t gfp)
1109{
1110 struct sctp_chunk *chunk;
1111
1112 list_for_each_entry(chunk, &msg->chunks, frag_list)
1113 sctp_outq_tail(&asoc->outqueue, chunk, gfp);
1114
1115 asoc->outqueue.sched->enqueue(&asoc->outqueue, msg);
1116}
1117
1118
1119/* These three macros allow us to pull the debugging code out of the
1120 * main flow of sctp_do_sm() to keep attention focused on the real
1121 * functionality there.
1122 */
1123#define debug_pre_sfn() \
1124 pr_debug("%s[pre-fn]: ep:%p, %s, %s, asoc:%p[%s], %s\n", __func__, \
1125 ep, sctp_evttype_tbl[event_type], (*debug_fn)(subtype), \
1126 asoc, sctp_state_tbl[state], state_fn->name)
1127
1128#define debug_post_sfn() \
1129 pr_debug("%s[post-fn]: asoc:%p, status:%s\n", __func__, asoc, \
1130 sctp_status_tbl[status])
1131
1132#define debug_post_sfx() \
1133 pr_debug("%s[post-sfx]: error:%d, asoc:%p[%s]\n", __func__, error, \
1134 asoc, sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
1135 sctp_assoc2id(asoc))) ? asoc->state : SCTP_STATE_CLOSED])
1136
1137/*
1138 * This is the master state machine processing function.
1139 *
1140 * If you want to understand all of lksctp, this is a
1141 * good place to start.
1142 */
1143int sctp_do_sm(struct net *net, enum sctp_event_type event_type,
1144 union sctp_subtype subtype, enum sctp_state state,
1145 struct sctp_endpoint *ep, struct sctp_association *asoc,
1146 void *event_arg, gfp_t gfp)
1147{
1148 typedef const char *(printfn_t)(union sctp_subtype);
1149 static printfn_t *table[] = {
1150 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
1151 };
1152 printfn_t *debug_fn __attribute__ ((unused)) = table[event_type];
1153 const struct sctp_sm_table_entry *state_fn;
1154 struct sctp_cmd_seq commands;
1155 enum sctp_disposition status;
1156 int error = 0;
1157
1158 /* Look up the state function, run it, and then process the
1159 * side effects. These three steps are the heart of lksctp.
1160 */
1161 state_fn = sctp_sm_lookup_event(net, event_type, state, subtype);
1162
1163 sctp_init_cmd_seq(&commands);
1164
1165 debug_pre_sfn();
1166 status = state_fn->fn(net, ep, asoc, subtype, event_arg, &commands);
1167 debug_post_sfn();
1168
1169 error = sctp_side_effects(event_type, subtype, state,
1170 ep, &asoc, event_arg, status,
1171 &commands, gfp);
1172 debug_post_sfx();
1173
1174 return error;
1175}
1176
1177/*****************************************************************
1178 * This the master state function side effect processing function.
1179 *****************************************************************/
1180static int sctp_side_effects(enum sctp_event_type event_type,
1181 union sctp_subtype subtype,
1182 enum sctp_state state,
1183 struct sctp_endpoint *ep,
1184 struct sctp_association **asoc,
1185 void *event_arg,
1186 enum sctp_disposition status,
1187 struct sctp_cmd_seq *commands,
1188 gfp_t gfp)
1189{
1190 int error;
1191
1192 /* FIXME - Most of the dispositions left today would be categorized
1193 * as "exceptional" dispositions. For those dispositions, it
1194 * may not be proper to run through any of the commands at all.
1195 * For example, the command interpreter might be run only with
1196 * disposition SCTP_DISPOSITION_CONSUME.
1197 */
1198 if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
1199 ep, *asoc,
1200 event_arg, status,
1201 commands, gfp)))
1202 goto bail;
1203
1204 switch (status) {
1205 case SCTP_DISPOSITION_DISCARD:
1206 pr_debug("%s: ignored sctp protocol event - state:%d, "
1207 "event_type:%d, event_id:%d\n", __func__, state,
1208 event_type, subtype.chunk);
1209 break;
1210
1211 case SCTP_DISPOSITION_NOMEM:
1212 /* We ran out of memory, so we need to discard this
1213 * packet.
1214 */
1215 /* BUG--we should now recover some memory, probably by
1216 * reneging...
1217 */
1218 error = -ENOMEM;
1219 break;
1220
1221 case SCTP_DISPOSITION_DELETE_TCB:
1222 case SCTP_DISPOSITION_ABORT:
1223 /* This should now be a command. */
1224 *asoc = NULL;
1225 break;
1226
1227 case SCTP_DISPOSITION_CONSUME:
1228 /*
1229 * We should no longer have much work to do here as the
1230 * real work has been done as explicit commands above.
1231 */
1232 break;
1233
1234 case SCTP_DISPOSITION_VIOLATION:
1235 net_err_ratelimited("protocol violation state %d chunkid %d\n",
1236 state, subtype.chunk);
1237 break;
1238
1239 case SCTP_DISPOSITION_NOT_IMPL:
1240 pr_warn("unimplemented feature in state %d, event_type %d, event_id %d\n",
1241 state, event_type, subtype.chunk);
1242 break;
1243
1244 case SCTP_DISPOSITION_BUG:
1245 pr_err("bug in state %d, event_type %d, event_id %d\n",
1246 state, event_type, subtype.chunk);
1247 BUG();
1248 break;
1249
1250 default:
1251 pr_err("impossible disposition %d in state %d, event_type %d, event_id %d\n",
1252 status, state, event_type, subtype.chunk);
1253 error = status;
1254 if (error >= 0)
1255 error = -EINVAL;
1256 WARN_ON_ONCE(1);
1257 break;
1258 }
1259
1260bail:
1261 return error;
1262}
1263
1264/********************************************************************
1265 * 2nd Level Abstractions
1266 ********************************************************************/
1267
1268/* This is the side-effect interpreter. */
1269static int sctp_cmd_interpreter(enum sctp_event_type event_type,
1270 union sctp_subtype subtype,
1271 enum sctp_state state,
1272 struct sctp_endpoint *ep,
1273 struct sctp_association *asoc,
1274 void *event_arg,
1275 enum sctp_disposition status,
1276 struct sctp_cmd_seq *commands,
1277 gfp_t gfp)
1278{
1279 struct sctp_sock *sp = sctp_sk(ep->base.sk);
1280 struct sctp_chunk *chunk = NULL, *new_obj;
1281 struct sctp_packet *packet;
1282 struct sctp_sackhdr sackh;
1283 struct timer_list *timer;
1284 struct sctp_transport *t;
1285 unsigned long timeout;
1286 struct sctp_cmd *cmd;
1287 int local_cork = 0;
1288 int error = 0;
1289 int force;
1290
1291 if (SCTP_EVENT_T_TIMEOUT != event_type)
1292 chunk = event_arg;
1293
1294 /* Note: This whole file is a huge candidate for rework.
1295 * For example, each command could either have its own handler, so
1296 * the loop would look like:
1297 * while (cmds)
1298 * cmd->handle(x, y, z)
1299 * --jgrimm
1300 */
1301 while (NULL != (cmd = sctp_next_cmd(commands))) {
1302 switch (cmd->verb) {
1303 case SCTP_CMD_NOP:
1304 /* Do nothing. */
1305 break;
1306
1307 case SCTP_CMD_NEW_ASOC:
1308 /* Register a new association. */
1309 if (local_cork) {
1310 sctp_outq_uncork(&asoc->outqueue, gfp);
1311 local_cork = 0;
1312 }
1313
1314 /* Register with the endpoint. */
1315 asoc = cmd->obj.asoc;
1316 BUG_ON(asoc->peer.primary_path == NULL);
1317 sctp_endpoint_add_asoc(ep, asoc);
1318 break;
1319
1320 case SCTP_CMD_PURGE_OUTQUEUE:
1321 sctp_outq_teardown(&asoc->outqueue);
1322 break;
1323
1324 case SCTP_CMD_DELETE_TCB:
1325 if (local_cork) {
1326 sctp_outq_uncork(&asoc->outqueue, gfp);
1327 local_cork = 0;
1328 }
1329 /* Delete the current association. */
1330 sctp_cmd_delete_tcb(commands, asoc);
1331 asoc = NULL;
1332 break;
1333
1334 case SCTP_CMD_NEW_STATE:
1335 /* Enter a new state. */
1336 sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1337 break;
1338
1339 case SCTP_CMD_REPORT_TSN:
1340 /* Record the arrival of a TSN. */
1341 error = sctp_tsnmap_mark(&asoc->peer.tsn_map,
1342 cmd->obj.u32, NULL);
1343 break;
1344
1345 case SCTP_CMD_REPORT_FWDTSN:
1346 asoc->stream.si->report_ftsn(&asoc->ulpq, cmd->obj.u32);
1347 break;
1348
1349 case SCTP_CMD_PROCESS_FWDTSN:
1350 asoc->stream.si->handle_ftsn(&asoc->ulpq,
1351 cmd->obj.chunk);
1352 break;
1353
1354 case SCTP_CMD_GEN_SACK:
1355 /* Generate a Selective ACK.
1356 * The argument tells us whether to just count
1357 * the packet and MAYBE generate a SACK, or
1358 * force a SACK out.
1359 */
1360 force = cmd->obj.i32;
1361 error = sctp_gen_sack(asoc, force, commands);
1362 break;
1363
1364 case SCTP_CMD_PROCESS_SACK:
1365 /* Process an inbound SACK. */
1366 error = sctp_cmd_process_sack(commands, asoc,
1367 cmd->obj.chunk);
1368 break;
1369
1370 case SCTP_CMD_GEN_INIT_ACK:
1371 /* Generate an INIT ACK chunk. */
1372 new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1373 0);
1374 if (!new_obj) {
1375 error = -ENOMEM;
1376 break;
1377 }
1378
1379 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1380 SCTP_CHUNK(new_obj));
1381 break;
1382
1383 case SCTP_CMD_PEER_INIT:
1384 /* Process a unified INIT from the peer.
1385 * Note: Only used during INIT-ACK processing. If
1386 * there is an error just return to the outter
1387 * layer which will bail.
1388 */
1389 error = sctp_cmd_process_init(commands, asoc, chunk,
1390 cmd->obj.init, gfp);
1391 break;
1392
1393 case SCTP_CMD_GEN_COOKIE_ECHO:
1394 /* Generate a COOKIE ECHO chunk. */
1395 new_obj = sctp_make_cookie_echo(asoc, chunk);
1396 if (!new_obj) {
1397 if (cmd->obj.chunk)
1398 sctp_chunk_free(cmd->obj.chunk);
1399 error = -ENOMEM;
1400 break;
1401 }
1402 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1403 SCTP_CHUNK(new_obj));
1404
1405 /* If there is an ERROR chunk to be sent along with
1406 * the COOKIE_ECHO, send it, too.
1407 */
1408 if (cmd->obj.chunk)
1409 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1410 SCTP_CHUNK(cmd->obj.chunk));
1411
1412 if (new_obj->transport) {
1413 new_obj->transport->init_sent_count++;
1414 asoc->init_last_sent_to = new_obj->transport;
1415 }
1416
1417 /* FIXME - Eventually come up with a cleaner way to
1418 * enabling COOKIE-ECHO + DATA bundling during
1419 * multihoming stale cookie scenarios, the following
1420 * command plays with asoc->peer.retran_path to
1421 * avoid the problem of sending the COOKIE-ECHO and
1422 * DATA in different paths, which could result
1423 * in the association being ABORTed if the DATA chunk
1424 * is processed first by the server. Checking the
1425 * init error counter simply causes this command
1426 * to be executed only during failed attempts of
1427 * association establishment.
1428 */
1429 if ((asoc->peer.retran_path !=
1430 asoc->peer.primary_path) &&
1431 (asoc->init_err_counter > 0)) {
1432 sctp_add_cmd_sf(commands,
1433 SCTP_CMD_FORCE_PRIM_RETRAN,
1434 SCTP_NULL());
1435 }
1436
1437 break;
1438
1439 case SCTP_CMD_GEN_SHUTDOWN:
1440 /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1441 * Reset error counts.
1442 */
1443 asoc->overall_error_count = 0;
1444
1445 /* Generate a SHUTDOWN chunk. */
1446 new_obj = sctp_make_shutdown(asoc, chunk);
1447 if (!new_obj) {
1448 error = -ENOMEM;
1449 break;
1450 }
1451 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1452 SCTP_CHUNK(new_obj));
1453 break;
1454
1455 case SCTP_CMD_CHUNK_ULP:
1456 /* Send a chunk to the sockets layer. */
1457 pr_debug("%s: sm_sideff: chunk_up:%p, ulpq:%p\n",
1458 __func__, cmd->obj.chunk, &asoc->ulpq);
1459
1460 asoc->stream.si->ulpevent_data(&asoc->ulpq,
1461 cmd->obj.chunk,
1462 GFP_ATOMIC);
1463 break;
1464
1465 case SCTP_CMD_EVENT_ULP:
1466 /* Send a notification to the sockets layer. */
1467 pr_debug("%s: sm_sideff: event_up:%p, ulpq:%p\n",
1468 __func__, cmd->obj.ulpevent, &asoc->ulpq);
1469
1470 asoc->stream.si->enqueue_event(&asoc->ulpq,
1471 cmd->obj.ulpevent);
1472 break;
1473
1474 case SCTP_CMD_REPLY:
1475 /* If an caller has not already corked, do cork. */
1476 if (!asoc->outqueue.cork) {
1477 sctp_outq_cork(&asoc->outqueue);
1478 local_cork = 1;
1479 }
1480 /* Send a chunk to our peer. */
1481 sctp_outq_tail(&asoc->outqueue, cmd->obj.chunk, gfp);
1482 break;
1483
1484 case SCTP_CMD_SEND_PKT:
1485 /* Send a full packet to our peer. */
1486 packet = cmd->obj.packet;
1487 sctp_packet_transmit(packet, gfp);
1488 sctp_ootb_pkt_free(packet);
1489 break;
1490
1491 case SCTP_CMD_T1_RETRAN:
1492 /* Mark a transport for retransmission. */
1493 sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1494 SCTP_RTXR_T1_RTX);
1495 break;
1496
1497 case SCTP_CMD_RETRAN:
1498 /* Mark a transport for retransmission. */
1499 sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1500 SCTP_RTXR_T3_RTX);
1501 break;
1502
1503 case SCTP_CMD_ECN_CE:
1504 /* Do delayed CE processing. */
1505 sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1506 break;
1507
1508 case SCTP_CMD_ECN_ECNE:
1509 /* Do delayed ECNE processing. */
1510 new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1511 chunk);
1512 if (new_obj)
1513 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1514 SCTP_CHUNK(new_obj));
1515 break;
1516
1517 case SCTP_CMD_ECN_CWR:
1518 /* Do delayed CWR processing. */
1519 sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1520 break;
1521
1522 case SCTP_CMD_SETUP_T2:
1523 sctp_cmd_setup_t2(commands, asoc, cmd->obj.chunk);
1524 break;
1525
1526 case SCTP_CMD_TIMER_START_ONCE:
1527 timer = &asoc->timers[cmd->obj.to];
1528
1529 if (timer_pending(timer))
1530 break;
1531 fallthrough;
1532
1533 case SCTP_CMD_TIMER_START:
1534 timer = &asoc->timers[cmd->obj.to];
1535 timeout = asoc->timeouts[cmd->obj.to];
1536 BUG_ON(!timeout);
1537
1538 /*
1539 * SCTP has a hard time with timer starts. Because we process
1540 * timer starts as side effects, it can be hard to tell if we
1541 * have already started a timer or not, which leads to BUG
1542 * halts when we call add_timer. So here, instead of just starting
1543 * a timer, if the timer is already started, and just mod
1544 * the timer with the shorter of the two expiration times
1545 */
1546 if (!timer_pending(timer))
1547 sctp_association_hold(asoc);
1548 timer_reduce(timer, jiffies + timeout);
1549 break;
1550
1551 case SCTP_CMD_TIMER_RESTART:
1552 timer = &asoc->timers[cmd->obj.to];
1553 timeout = asoc->timeouts[cmd->obj.to];
1554 if (!mod_timer(timer, jiffies + timeout))
1555 sctp_association_hold(asoc);
1556 break;
1557
1558 case SCTP_CMD_TIMER_STOP:
1559 timer = &asoc->timers[cmd->obj.to];
1560 if (del_timer(timer))
1561 sctp_association_put(asoc);
1562 break;
1563
1564 case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1565 chunk = cmd->obj.chunk;
1566 t = sctp_assoc_choose_alter_transport(asoc,
1567 asoc->init_last_sent_to);
1568 asoc->init_last_sent_to = t;
1569 chunk->transport = t;
1570 t->init_sent_count++;
1571 /* Set the new transport as primary */
1572 sctp_assoc_set_primary(asoc, t);
1573 break;
1574
1575 case SCTP_CMD_INIT_RESTART:
1576 /* Do the needed accounting and updates
1577 * associated with restarting an initialization
1578 * timer. Only multiply the timeout by two if
1579 * all transports have been tried at the current
1580 * timeout.
1581 */
1582 sctp_cmd_t1_timer_update(asoc,
1583 SCTP_EVENT_TIMEOUT_T1_INIT,
1584 "INIT");
1585
1586 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1587 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1588 break;
1589
1590 case SCTP_CMD_COOKIEECHO_RESTART:
1591 /* Do the needed accounting and updates
1592 * associated with restarting an initialization
1593 * timer. Only multiply the timeout by two if
1594 * all transports have been tried at the current
1595 * timeout.
1596 */
1597 sctp_cmd_t1_timer_update(asoc,
1598 SCTP_EVENT_TIMEOUT_T1_COOKIE,
1599 "COOKIE");
1600
1601 /* If we've sent any data bundled with
1602 * COOKIE-ECHO we need to resend.
1603 */
1604 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1605 transports) {
1606 sctp_retransmit_mark(&asoc->outqueue, t,
1607 SCTP_RTXR_T1_RTX);
1608 }
1609
1610 sctp_add_cmd_sf(commands,
1611 SCTP_CMD_TIMER_RESTART,
1612 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1613 break;
1614
1615 case SCTP_CMD_INIT_FAILED:
1616 sctp_cmd_init_failed(commands, asoc, cmd->obj.u16);
1617 break;
1618
1619 case SCTP_CMD_ASSOC_FAILED:
1620 sctp_cmd_assoc_failed(commands, asoc, event_type,
1621 subtype, chunk, cmd->obj.u16);
1622 break;
1623
1624 case SCTP_CMD_INIT_COUNTER_INC:
1625 asoc->init_err_counter++;
1626 break;
1627
1628 case SCTP_CMD_INIT_COUNTER_RESET:
1629 asoc->init_err_counter = 0;
1630 asoc->init_cycle = 0;
1631 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1632 transports) {
1633 t->init_sent_count = 0;
1634 }
1635 break;
1636
1637 case SCTP_CMD_REPORT_DUP:
1638 sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1639 cmd->obj.u32);
1640 break;
1641
1642 case SCTP_CMD_REPORT_BAD_TAG:
1643 pr_debug("%s: vtag mismatch!\n", __func__);
1644 break;
1645
1646 case SCTP_CMD_STRIKE:
1647 /* Mark one strike against a transport. */
1648 sctp_do_8_2_transport_strike(commands, asoc,
1649 cmd->obj.transport, 0);
1650 break;
1651
1652 case SCTP_CMD_TRANSPORT_IDLE:
1653 t = cmd->obj.transport;
1654 sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
1655 break;
1656
1657 case SCTP_CMD_TRANSPORT_HB_SENT:
1658 t = cmd->obj.transport;
1659 sctp_do_8_2_transport_strike(commands, asoc,
1660 t, 1);
1661 t->hb_sent = 1;
1662 break;
1663
1664 case SCTP_CMD_TRANSPORT_ON:
1665 t = cmd->obj.transport;
1666 sctp_cmd_transport_on(commands, asoc, t, chunk);
1667 break;
1668
1669 case SCTP_CMD_HB_TIMERS_START:
1670 sctp_cmd_hb_timers_start(commands, asoc);
1671 break;
1672
1673 case SCTP_CMD_HB_TIMER_UPDATE:
1674 t = cmd->obj.transport;
1675 sctp_transport_reset_hb_timer(t);
1676 break;
1677
1678 case SCTP_CMD_HB_TIMERS_STOP:
1679 sctp_cmd_hb_timers_stop(commands, asoc);
1680 break;
1681
1682 case SCTP_CMD_PROBE_TIMER_UPDATE:
1683 t = cmd->obj.transport;
1684 sctp_transport_reset_probe_timer(t);
1685 break;
1686
1687 case SCTP_CMD_REPORT_ERROR:
1688 error = cmd->obj.error;
1689 break;
1690
1691 case SCTP_CMD_PROCESS_CTSN:
1692 /* Dummy up a SACK for processing. */
1693 sackh.cum_tsn_ack = cmd->obj.be32;
1694 sackh.a_rwnd = htonl(asoc->peer.rwnd +
1695 asoc->outqueue.outstanding_bytes);
1696 sackh.num_gap_ack_blocks = 0;
1697 sackh.num_dup_tsns = 0;
1698 chunk->subh.sack_hdr = &sackh;
1699 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1700 SCTP_CHUNK(chunk));
1701 break;
1702
1703 case SCTP_CMD_DISCARD_PACKET:
1704 /* We need to discard the whole packet.
1705 * Uncork the queue since there might be
1706 * responses pending
1707 */
1708 chunk->pdiscard = 1;
1709 if (asoc) {
1710 sctp_outq_uncork(&asoc->outqueue, gfp);
1711 local_cork = 0;
1712 }
1713 break;
1714
1715 case SCTP_CMD_RTO_PENDING:
1716 t = cmd->obj.transport;
1717 t->rto_pending = 1;
1718 break;
1719
1720 case SCTP_CMD_PART_DELIVER:
1721 asoc->stream.si->start_pd(&asoc->ulpq, GFP_ATOMIC);
1722 break;
1723
1724 case SCTP_CMD_RENEGE:
1725 asoc->stream.si->renege_events(&asoc->ulpq,
1726 cmd->obj.chunk,
1727 GFP_ATOMIC);
1728 break;
1729
1730 case SCTP_CMD_SETUP_T4:
1731 sctp_cmd_setup_t4(commands, asoc, cmd->obj.chunk);
1732 break;
1733
1734 case SCTP_CMD_PROCESS_OPERR:
1735 sctp_cmd_process_operr(commands, asoc, chunk);
1736 break;
1737 case SCTP_CMD_CLEAR_INIT_TAG:
1738 asoc->peer.i.init_tag = 0;
1739 break;
1740 case SCTP_CMD_DEL_NON_PRIMARY:
1741 sctp_cmd_del_non_primary(asoc);
1742 break;
1743 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1744 sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1745 break;
1746 case SCTP_CMD_FORCE_PRIM_RETRAN:
1747 t = asoc->peer.retran_path;
1748 asoc->peer.retran_path = asoc->peer.primary_path;
1749 sctp_outq_uncork(&asoc->outqueue, gfp);
1750 local_cork = 0;
1751 asoc->peer.retran_path = t;
1752 break;
1753 case SCTP_CMD_SET_SK_ERR:
1754 sctp_cmd_set_sk_err(asoc, cmd->obj.error);
1755 break;
1756 case SCTP_CMD_ASSOC_CHANGE:
1757 sctp_cmd_assoc_change(commands, asoc,
1758 cmd->obj.u8);
1759 break;
1760 case SCTP_CMD_ADAPTATION_IND:
1761 sctp_cmd_adaptation_ind(commands, asoc);
1762 break;
1763 case SCTP_CMD_PEER_NO_AUTH:
1764 sctp_cmd_peer_no_auth(commands, asoc);
1765 break;
1766
1767 case SCTP_CMD_ASSOC_SHKEY:
1768 error = sctp_auth_asoc_init_active_key(asoc,
1769 GFP_ATOMIC);
1770 break;
1771 case SCTP_CMD_UPDATE_INITTAG:
1772 asoc->peer.i.init_tag = cmd->obj.u32;
1773 break;
1774 case SCTP_CMD_SEND_MSG:
1775 if (!asoc->outqueue.cork) {
1776 sctp_outq_cork(&asoc->outqueue);
1777 local_cork = 1;
1778 }
1779 sctp_cmd_send_msg(asoc, cmd->obj.msg, gfp);
1780 break;
1781 case SCTP_CMD_PURGE_ASCONF_QUEUE:
1782 sctp_asconf_queue_teardown(asoc);
1783 break;
1784
1785 case SCTP_CMD_SET_ASOC:
1786 if (asoc && local_cork) {
1787 sctp_outq_uncork(&asoc->outqueue, gfp);
1788 local_cork = 0;
1789 }
1790 asoc = cmd->obj.asoc;
1791 break;
1792
1793 default:
1794 pr_warn("Impossible command: %u\n",
1795 cmd->verb);
1796 break;
1797 }
1798
1799 if (error) {
1800 cmd = sctp_next_cmd(commands);
1801 while (cmd) {
1802 if (cmd->verb == SCTP_CMD_REPLY)
1803 sctp_chunk_free(cmd->obj.chunk);
1804 cmd = sctp_next_cmd(commands);
1805 }
1806 break;
1807 }
1808 }
1809
1810 /* If this is in response to a received chunk, wait until
1811 * we are done with the packet to open the queue so that we don't
1812 * send multiple packets in response to a single request.
1813 */
1814 if (asoc && SCTP_EVENT_T_CHUNK == event_type && chunk) {
1815 if (chunk->end_of_packet || chunk->singleton)
1816 sctp_outq_uncork(&asoc->outqueue, gfp);
1817 } else if (local_cork)
1818 sctp_outq_uncork(&asoc->outqueue, gfp);
1819
1820 if (sp->data_ready_signalled)
1821 sp->data_ready_signalled = 0;
1822
1823 return error;
1824}
1/* SCTP kernel implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 *
6 * This file is part of the SCTP kernel implementation
7 *
8 * These functions work with the state functions in sctp_sm_statefuns.c
9 * to implement that state operations. These functions implement the
10 * steps which require modifying existing data structures.
11 *
12 * This SCTP implementation is free software;
13 * you can redistribute it and/or modify it under the terms of
14 * the GNU General Public License as published by
15 * the Free Software Foundation; either version 2, or (at your option)
16 * any later version.
17 *
18 * This SCTP implementation is distributed in the hope that it
19 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
20 * ************************
21 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
22 * See the GNU General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License
25 * along with GNU CC; see the file COPYING. If not, write to
26 * the Free Software Foundation, 59 Temple Place - Suite 330,
27 * Boston, MA 02111-1307, USA.
28 *
29 * Please send any bug reports or fixes you make to the
30 * email address(es):
31 * lksctp developers <lksctp-developers@lists.sourceforge.net>
32 *
33 * Or submit a bug report through the following website:
34 * http://www.sf.net/projects/lksctp
35 *
36 * Written or modified by:
37 * La Monte H.P. Yarroll <piggy@acm.org>
38 * Karl Knutson <karl@athena.chicago.il.us>
39 * Jon Grimm <jgrimm@austin.ibm.com>
40 * Hui Huang <hui.huang@nokia.com>
41 * Dajiang Zhang <dajiang.zhang@nokia.com>
42 * Daisy Chang <daisyc@us.ibm.com>
43 * Sridhar Samudrala <sri@us.ibm.com>
44 * Ardelle Fan <ardelle.fan@intel.com>
45 *
46 * Any bugs reported given to us we will try to fix... any fixes shared will
47 * be incorporated into the next SCTP release.
48 */
49
50#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
51
52#include <linux/skbuff.h>
53#include <linux/types.h>
54#include <linux/socket.h>
55#include <linux/ip.h>
56#include <linux/gfp.h>
57#include <net/sock.h>
58#include <net/sctp/sctp.h>
59#include <net/sctp/sm.h>
60
61static int sctp_cmd_interpreter(sctp_event_t event_type,
62 sctp_subtype_t subtype,
63 sctp_state_t state,
64 struct sctp_endpoint *ep,
65 struct sctp_association *asoc,
66 void *event_arg,
67 sctp_disposition_t status,
68 sctp_cmd_seq_t *commands,
69 gfp_t gfp);
70static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
71 sctp_state_t state,
72 struct sctp_endpoint *ep,
73 struct sctp_association *asoc,
74 void *event_arg,
75 sctp_disposition_t status,
76 sctp_cmd_seq_t *commands,
77 gfp_t gfp);
78
79/********************************************************************
80 * Helper functions
81 ********************************************************************/
82
83/* A helper function for delayed processing of INET ECN CE bit. */
84static void sctp_do_ecn_ce_work(struct sctp_association *asoc,
85 __u32 lowest_tsn)
86{
87 /* Save the TSN away for comparison when we receive CWR */
88
89 asoc->last_ecne_tsn = lowest_tsn;
90 asoc->need_ecne = 1;
91}
92
93/* Helper function for delayed processing of SCTP ECNE chunk. */
94/* RFC 2960 Appendix A
95 *
96 * RFC 2481 details a specific bit for a sender to send in
97 * the header of its next outbound TCP segment to indicate to
98 * its peer that it has reduced its congestion window. This
99 * is termed the CWR bit. For SCTP the same indication is made
100 * by including the CWR chunk. This chunk contains one data
101 * element, i.e. the TSN number that was sent in the ECNE chunk.
102 * This element represents the lowest TSN number in the datagram
103 * that was originally marked with the CE bit.
104 */
105static struct sctp_chunk *sctp_do_ecn_ecne_work(struct sctp_association *asoc,
106 __u32 lowest_tsn,
107 struct sctp_chunk *chunk)
108{
109 struct sctp_chunk *repl;
110
111 /* Our previously transmitted packet ran into some congestion
112 * so we should take action by reducing cwnd and ssthresh
113 * and then ACK our peer that we we've done so by
114 * sending a CWR.
115 */
116
117 /* First, try to determine if we want to actually lower
118 * our cwnd variables. Only lower them if the ECNE looks more
119 * recent than the last response.
120 */
121 if (TSN_lt(asoc->last_cwr_tsn, lowest_tsn)) {
122 struct sctp_transport *transport;
123
124 /* Find which transport's congestion variables
125 * need to be adjusted.
126 */
127 transport = sctp_assoc_lookup_tsn(asoc, lowest_tsn);
128
129 /* Update the congestion variables. */
130 if (transport)
131 sctp_transport_lower_cwnd(transport,
132 SCTP_LOWER_CWND_ECNE);
133 asoc->last_cwr_tsn = lowest_tsn;
134 }
135
136 /* Always try to quiet the other end. In case of lost CWR,
137 * resend last_cwr_tsn.
138 */
139 repl = sctp_make_cwr(asoc, asoc->last_cwr_tsn, chunk);
140
141 /* If we run out of memory, it will look like a lost CWR. We'll
142 * get back in sync eventually.
143 */
144 return repl;
145}
146
147/* Helper function to do delayed processing of ECN CWR chunk. */
148static void sctp_do_ecn_cwr_work(struct sctp_association *asoc,
149 __u32 lowest_tsn)
150{
151 /* Turn off ECNE getting auto-prepended to every outgoing
152 * packet
153 */
154 asoc->need_ecne = 0;
155}
156
157/* Generate SACK if necessary. We call this at the end of a packet. */
158static int sctp_gen_sack(struct sctp_association *asoc, int force,
159 sctp_cmd_seq_t *commands)
160{
161 __u32 ctsn, max_tsn_seen;
162 struct sctp_chunk *sack;
163 struct sctp_transport *trans = asoc->peer.last_data_from;
164 int error = 0;
165
166 if (force ||
167 (!trans && (asoc->param_flags & SPP_SACKDELAY_DISABLE)) ||
168 (trans && (trans->param_flags & SPP_SACKDELAY_DISABLE)))
169 asoc->peer.sack_needed = 1;
170
171 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
172 max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
173
174 /* From 12.2 Parameters necessary per association (i.e. the TCB):
175 *
176 * Ack State : This flag indicates if the next received packet
177 * : is to be responded to with a SACK. ...
178 * : When DATA chunks are out of order, SACK's
179 * : are not delayed (see Section 6).
180 *
181 * [This is actually not mentioned in Section 6, but we
182 * implement it here anyway. --piggy]
183 */
184 if (max_tsn_seen != ctsn)
185 asoc->peer.sack_needed = 1;
186
187 /* From 6.2 Acknowledgement on Reception of DATA Chunks:
188 *
189 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically,
190 * an acknowledgement SHOULD be generated for at least every
191 * second packet (not every second DATA chunk) received, and
192 * SHOULD be generated within 200 ms of the arrival of any
193 * unacknowledged DATA chunk. ...
194 */
195 if (!asoc->peer.sack_needed) {
196 asoc->peer.sack_cnt++;
197
198 /* Set the SACK delay timeout based on the
199 * SACK delay for the last transport
200 * data was received from, or the default
201 * for the association.
202 */
203 if (trans) {
204 /* We will need a SACK for the next packet. */
205 if (asoc->peer.sack_cnt >= trans->sackfreq - 1)
206 asoc->peer.sack_needed = 1;
207
208 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
209 trans->sackdelay;
210 } else {
211 /* We will need a SACK for the next packet. */
212 if (asoc->peer.sack_cnt >= asoc->sackfreq - 1)
213 asoc->peer.sack_needed = 1;
214
215 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
216 asoc->sackdelay;
217 }
218
219 /* Restart the SACK timer. */
220 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
221 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
222 } else {
223 asoc->a_rwnd = asoc->rwnd;
224 sack = sctp_make_sack(asoc);
225 if (!sack)
226 goto nomem;
227
228 asoc->peer.sack_needed = 0;
229 asoc->peer.sack_cnt = 0;
230
231 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(sack));
232
233 /* Stop the SACK timer. */
234 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
235 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
236 }
237
238 return error;
239nomem:
240 error = -ENOMEM;
241 return error;
242}
243
244/* When the T3-RTX timer expires, it calls this function to create the
245 * relevant state machine event.
246 */
247void sctp_generate_t3_rtx_event(unsigned long peer)
248{
249 int error;
250 struct sctp_transport *transport = (struct sctp_transport *) peer;
251 struct sctp_association *asoc = transport->asoc;
252
253 /* Check whether a task is in the sock. */
254
255 sctp_bh_lock_sock(asoc->base.sk);
256 if (sock_owned_by_user(asoc->base.sk)) {
257 SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __func__);
258
259 /* Try again later. */
260 if (!mod_timer(&transport->T3_rtx_timer, jiffies + (HZ/20)))
261 sctp_transport_hold(transport);
262 goto out_unlock;
263 }
264
265 /* Is this transport really dead and just waiting around for
266 * the timer to let go of the reference?
267 */
268 if (transport->dead)
269 goto out_unlock;
270
271 /* Run through the state machine. */
272 error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
273 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX),
274 asoc->state,
275 asoc->ep, asoc,
276 transport, GFP_ATOMIC);
277
278 if (error)
279 asoc->base.sk->sk_err = -error;
280
281out_unlock:
282 sctp_bh_unlock_sock(asoc->base.sk);
283 sctp_transport_put(transport);
284}
285
286/* This is a sa interface for producing timeout events. It works
287 * for timeouts which use the association as their parameter.
288 */
289static void sctp_generate_timeout_event(struct sctp_association *asoc,
290 sctp_event_timeout_t timeout_type)
291{
292 int error = 0;
293
294 sctp_bh_lock_sock(asoc->base.sk);
295 if (sock_owned_by_user(asoc->base.sk)) {
296 SCTP_DEBUG_PRINTK("%s:Sock is busy: timer %d\n",
297 __func__,
298 timeout_type);
299
300 /* Try again later. */
301 if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20)))
302 sctp_association_hold(asoc);
303 goto out_unlock;
304 }
305
306 /* Is this association really dead and just waiting around for
307 * the timer to let go of the reference?
308 */
309 if (asoc->base.dead)
310 goto out_unlock;
311
312 /* Run through the state machine. */
313 error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
314 SCTP_ST_TIMEOUT(timeout_type),
315 asoc->state, asoc->ep, asoc,
316 (void *)timeout_type, GFP_ATOMIC);
317
318 if (error)
319 asoc->base.sk->sk_err = -error;
320
321out_unlock:
322 sctp_bh_unlock_sock(asoc->base.sk);
323 sctp_association_put(asoc);
324}
325
326static void sctp_generate_t1_cookie_event(unsigned long data)
327{
328 struct sctp_association *asoc = (struct sctp_association *) data;
329 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
330}
331
332static void sctp_generate_t1_init_event(unsigned long data)
333{
334 struct sctp_association *asoc = (struct sctp_association *) data;
335 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
336}
337
338static void sctp_generate_t2_shutdown_event(unsigned long data)
339{
340 struct sctp_association *asoc = (struct sctp_association *) data;
341 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
342}
343
344static void sctp_generate_t4_rto_event(unsigned long data)
345{
346 struct sctp_association *asoc = (struct sctp_association *) data;
347 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
348}
349
350static void sctp_generate_t5_shutdown_guard_event(unsigned long data)
351{
352 struct sctp_association *asoc = (struct sctp_association *)data;
353 sctp_generate_timeout_event(asoc,
354 SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);
355
356} /* sctp_generate_t5_shutdown_guard_event() */
357
358static void sctp_generate_autoclose_event(unsigned long data)
359{
360 struct sctp_association *asoc = (struct sctp_association *) data;
361 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE);
362}
363
364/* Generate a heart beat event. If the sock is busy, reschedule. Make
365 * sure that the transport is still valid.
366 */
367void sctp_generate_heartbeat_event(unsigned long data)
368{
369 int error = 0;
370 struct sctp_transport *transport = (struct sctp_transport *) data;
371 struct sctp_association *asoc = transport->asoc;
372
373 sctp_bh_lock_sock(asoc->base.sk);
374 if (sock_owned_by_user(asoc->base.sk)) {
375 SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __func__);
376
377 /* Try again later. */
378 if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20)))
379 sctp_transport_hold(transport);
380 goto out_unlock;
381 }
382
383 /* Is this structure just waiting around for us to actually
384 * get destroyed?
385 */
386 if (transport->dead)
387 goto out_unlock;
388
389 error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
390 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
391 asoc->state, asoc->ep, asoc,
392 transport, GFP_ATOMIC);
393
394 if (error)
395 asoc->base.sk->sk_err = -error;
396
397out_unlock:
398 sctp_bh_unlock_sock(asoc->base.sk);
399 sctp_transport_put(transport);
400}
401
402/* Handle the timeout of the ICMP protocol unreachable timer. Trigger
403 * the correct state machine transition that will close the association.
404 */
405void sctp_generate_proto_unreach_event(unsigned long data)
406{
407 struct sctp_transport *transport = (struct sctp_transport *) data;
408 struct sctp_association *asoc = transport->asoc;
409
410 sctp_bh_lock_sock(asoc->base.sk);
411 if (sock_owned_by_user(asoc->base.sk)) {
412 SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __func__);
413
414 /* Try again later. */
415 if (!mod_timer(&transport->proto_unreach_timer,
416 jiffies + (HZ/20)))
417 sctp_association_hold(asoc);
418 goto out_unlock;
419 }
420
421 /* Is this structure just waiting around for us to actually
422 * get destroyed?
423 */
424 if (asoc->base.dead)
425 goto out_unlock;
426
427 sctp_do_sm(SCTP_EVENT_T_OTHER,
428 SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH),
429 asoc->state, asoc->ep, asoc, transport, GFP_ATOMIC);
430
431out_unlock:
432 sctp_bh_unlock_sock(asoc->base.sk);
433 sctp_association_put(asoc);
434}
435
436
437/* Inject a SACK Timeout event into the state machine. */
438static void sctp_generate_sack_event(unsigned long data)
439{
440 struct sctp_association *asoc = (struct sctp_association *) data;
441 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
442}
443
444sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
445 NULL,
446 sctp_generate_t1_cookie_event,
447 sctp_generate_t1_init_event,
448 sctp_generate_t2_shutdown_event,
449 NULL,
450 sctp_generate_t4_rto_event,
451 sctp_generate_t5_shutdown_guard_event,
452 NULL,
453 sctp_generate_sack_event,
454 sctp_generate_autoclose_event,
455};
456
457
458/* RFC 2960 8.2 Path Failure Detection
459 *
460 * When its peer endpoint is multi-homed, an endpoint should keep a
461 * error counter for each of the destination transport addresses of the
462 * peer endpoint.
463 *
464 * Each time the T3-rtx timer expires on any address, or when a
465 * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
466 * the error counter of that destination address will be incremented.
467 * When the value in the error counter exceeds the protocol parameter
468 * 'Path.Max.Retrans' of that destination address, the endpoint should
469 * mark the destination transport address as inactive, and a
470 * notification SHOULD be sent to the upper layer.
471 *
472 */
473static void sctp_do_8_2_transport_strike(struct sctp_association *asoc,
474 struct sctp_transport *transport,
475 int is_hb)
476{
477 /* The check for association's overall error counter exceeding the
478 * threshold is done in the state function.
479 */
480 /* We are here due to a timer expiration. If the timer was
481 * not a HEARTBEAT, then normal error tracking is done.
482 * If the timer was a heartbeat, we only increment error counts
483 * when we already have an outstanding HEARTBEAT that has not
484 * been acknowledged.
485 * Additionally, some tranport states inhibit error increments.
486 */
487 if (!is_hb) {
488 asoc->overall_error_count++;
489 if (transport->state != SCTP_INACTIVE)
490 transport->error_count++;
491 } else if (transport->hb_sent) {
492 if (transport->state != SCTP_UNCONFIRMED)
493 asoc->overall_error_count++;
494 if (transport->state != SCTP_INACTIVE)
495 transport->error_count++;
496 }
497
498 if (transport->state != SCTP_INACTIVE &&
499 (transport->error_count > transport->pathmaxrxt)) {
500 SCTP_DEBUG_PRINTK_IPADDR("transport_strike:association %p",
501 " transport IP: port:%d failed.\n",
502 asoc,
503 (&transport->ipaddr),
504 ntohs(transport->ipaddr.v4.sin_port));
505 sctp_assoc_control_transport(asoc, transport,
506 SCTP_TRANSPORT_DOWN,
507 SCTP_FAILED_THRESHOLD);
508 }
509
510 /* E2) For the destination address for which the timer
511 * expires, set RTO <- RTO * 2 ("back off the timer"). The
512 * maximum value discussed in rule C7 above (RTO.max) may be
513 * used to provide an upper bound to this doubling operation.
514 *
515 * Special Case: the first HB doesn't trigger exponential backoff.
516 * The first unacknowledged HB triggers it. We do this with a flag
517 * that indicates that we have an outstanding HB.
518 */
519 if (!is_hb || transport->hb_sent) {
520 transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
521 }
522}
523
524/* Worker routine to handle INIT command failure. */
525static void sctp_cmd_init_failed(sctp_cmd_seq_t *commands,
526 struct sctp_association *asoc,
527 unsigned error)
528{
529 struct sctp_ulpevent *event;
530
531 event = sctp_ulpevent_make_assoc_change(asoc,0, SCTP_CANT_STR_ASSOC,
532 (__u16)error, 0, 0, NULL,
533 GFP_ATOMIC);
534
535 if (event)
536 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
537 SCTP_ULPEVENT(event));
538
539 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
540 SCTP_STATE(SCTP_STATE_CLOSED));
541
542 /* SEND_FAILED sent later when cleaning up the association. */
543 asoc->outqueue.error = error;
544 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
545}
546
547/* Worker routine to handle SCTP_CMD_ASSOC_FAILED. */
548static void sctp_cmd_assoc_failed(sctp_cmd_seq_t *commands,
549 struct sctp_association *asoc,
550 sctp_event_t event_type,
551 sctp_subtype_t subtype,
552 struct sctp_chunk *chunk,
553 unsigned error)
554{
555 struct sctp_ulpevent *event;
556
557 /* Cancel any partial delivery in progress. */
558 sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
559
560 if (event_type == SCTP_EVENT_T_CHUNK && subtype.chunk == SCTP_CID_ABORT)
561 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
562 (__u16)error, 0, 0, chunk,
563 GFP_ATOMIC);
564 else
565 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
566 (__u16)error, 0, 0, NULL,
567 GFP_ATOMIC);
568 if (event)
569 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
570 SCTP_ULPEVENT(event));
571
572 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
573 SCTP_STATE(SCTP_STATE_CLOSED));
574
575 /* SEND_FAILED sent later when cleaning up the association. */
576 asoc->outqueue.error = error;
577 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
578}
579
580/* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
581 * inside the cookie. In reality, this is only used for INIT-ACK processing
582 * since all other cases use "temporary" associations and can do all
583 * their work in statefuns directly.
584 */
585static int sctp_cmd_process_init(sctp_cmd_seq_t *commands,
586 struct sctp_association *asoc,
587 struct sctp_chunk *chunk,
588 sctp_init_chunk_t *peer_init,
589 gfp_t gfp)
590{
591 int error;
592
593 /* We only process the init as a sideeffect in a single
594 * case. This is when we process the INIT-ACK. If we
595 * fail during INIT processing (due to malloc problems),
596 * just return the error and stop processing the stack.
597 */
598 if (!sctp_process_init(asoc, chunk, sctp_source(chunk), peer_init, gfp))
599 error = -ENOMEM;
600 else
601 error = 0;
602
603 return error;
604}
605
606/* Helper function to break out starting up of heartbeat timers. */
607static void sctp_cmd_hb_timers_start(sctp_cmd_seq_t *cmds,
608 struct sctp_association *asoc)
609{
610 struct sctp_transport *t;
611
612 /* Start a heartbeat timer for each transport on the association.
613 * hold a reference on the transport to make sure none of
614 * the needed data structures go away.
615 */
616 list_for_each_entry(t, &asoc->peer.transport_addr_list, transports) {
617
618 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
619 sctp_transport_hold(t);
620 }
621}
622
623static void sctp_cmd_hb_timers_stop(sctp_cmd_seq_t *cmds,
624 struct sctp_association *asoc)
625{
626 struct sctp_transport *t;
627
628 /* Stop all heartbeat timers. */
629
630 list_for_each_entry(t, &asoc->peer.transport_addr_list,
631 transports) {
632 if (del_timer(&t->hb_timer))
633 sctp_transport_put(t);
634 }
635}
636
637/* Helper function to stop any pending T3-RTX timers */
638static void sctp_cmd_t3_rtx_timers_stop(sctp_cmd_seq_t *cmds,
639 struct sctp_association *asoc)
640{
641 struct sctp_transport *t;
642
643 list_for_each_entry(t, &asoc->peer.transport_addr_list,
644 transports) {
645 if (timer_pending(&t->T3_rtx_timer) &&
646 del_timer(&t->T3_rtx_timer)) {
647 sctp_transport_put(t);
648 }
649 }
650}
651
652
653/* Helper function to update the heartbeat timer. */
654static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
655 struct sctp_transport *t)
656{
657 /* Update the heartbeat timer. */
658 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
659 sctp_transport_hold(t);
660}
661
662/* Helper function to handle the reception of an HEARTBEAT ACK. */
663static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds,
664 struct sctp_association *asoc,
665 struct sctp_transport *t,
666 struct sctp_chunk *chunk)
667{
668 sctp_sender_hb_info_t *hbinfo;
669
670 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
671 * HEARTBEAT should clear the error counter of the destination
672 * transport address to which the HEARTBEAT was sent.
673 */
674 t->error_count = 0;
675
676 /*
677 * Although RFC4960 specifies that the overall error count must
678 * be cleared when a HEARTBEAT ACK is received, we make an
679 * exception while in SHUTDOWN PENDING. If the peer keeps its
680 * window shut forever, we may never be able to transmit our
681 * outstanding data and rely on the retransmission limit be reached
682 * to shutdown the association.
683 */
684 if (t->asoc->state != SCTP_STATE_SHUTDOWN_PENDING)
685 t->asoc->overall_error_count = 0;
686
687 /* Clear the hb_sent flag to signal that we had a good
688 * acknowledgement.
689 */
690 t->hb_sent = 0;
691
692 /* Mark the destination transport address as active if it is not so
693 * marked.
694 */
695 if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED))
696 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
697 SCTP_HEARTBEAT_SUCCESS);
698
699 /* The receiver of the HEARTBEAT ACK should also perform an
700 * RTT measurement for that destination transport address
701 * using the time value carried in the HEARTBEAT ACK chunk.
702 * If the transport's rto_pending variable has been cleared,
703 * it was most likely due to a retransmit. However, we want
704 * to re-enable it to properly update the rto.
705 */
706 if (t->rto_pending == 0)
707 t->rto_pending = 1;
708
709 hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
710 sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
711
712 /* Update the heartbeat timer. */
713 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
714 sctp_transport_hold(t);
715}
716
717
718/* Helper function to process the process SACK command. */
719static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds,
720 struct sctp_association *asoc,
721 struct sctp_sackhdr *sackh)
722{
723 int err = 0;
724
725 if (sctp_outq_sack(&asoc->outqueue, sackh)) {
726 /* There are no more TSNs awaiting SACK. */
727 err = sctp_do_sm(SCTP_EVENT_T_OTHER,
728 SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
729 asoc->state, asoc->ep, asoc, NULL,
730 GFP_ATOMIC);
731 }
732
733 return err;
734}
735
736/* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
737 * the transport for a shutdown chunk.
738 */
739static void sctp_cmd_setup_t2(sctp_cmd_seq_t *cmds,
740 struct sctp_association *asoc,
741 struct sctp_chunk *chunk)
742{
743 struct sctp_transport *t;
744
745 if (chunk->transport)
746 t = chunk->transport;
747 else {
748 t = sctp_assoc_choose_alter_transport(asoc,
749 asoc->shutdown_last_sent_to);
750 chunk->transport = t;
751 }
752 asoc->shutdown_last_sent_to = t;
753 asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
754}
755
756/* Helper function to change the state of an association. */
757static void sctp_cmd_new_state(sctp_cmd_seq_t *cmds,
758 struct sctp_association *asoc,
759 sctp_state_t state)
760{
761 struct sock *sk = asoc->base.sk;
762
763 asoc->state = state;
764
765 SCTP_DEBUG_PRINTK("sctp_cmd_new_state: asoc %p[%s]\n",
766 asoc, sctp_state_tbl[state]);
767
768 if (sctp_style(sk, TCP)) {
769 /* Change the sk->sk_state of a TCP-style socket that has
770 * successfully completed a connect() call.
771 */
772 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
773 sk->sk_state = SCTP_SS_ESTABLISHED;
774
775 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
776 if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
777 sctp_sstate(sk, ESTABLISHED))
778 sk->sk_shutdown |= RCV_SHUTDOWN;
779 }
780
781 if (sctp_state(asoc, COOKIE_WAIT)) {
782 /* Reset init timeouts since they may have been
783 * increased due to timer expirations.
784 */
785 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
786 asoc->rto_initial;
787 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
788 asoc->rto_initial;
789 }
790
791 if (sctp_state(asoc, ESTABLISHED) ||
792 sctp_state(asoc, CLOSED) ||
793 sctp_state(asoc, SHUTDOWN_RECEIVED)) {
794 /* Wake up any processes waiting in the asoc's wait queue in
795 * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
796 */
797 if (waitqueue_active(&asoc->wait))
798 wake_up_interruptible(&asoc->wait);
799
800 /* Wake up any processes waiting in the sk's sleep queue of
801 * a TCP-style or UDP-style peeled-off socket in
802 * sctp_wait_for_accept() or sctp_wait_for_packet().
803 * For a UDP-style socket, the waiters are woken up by the
804 * notifications.
805 */
806 if (!sctp_style(sk, UDP))
807 sk->sk_state_change(sk);
808 }
809}
810
811/* Helper function to delete an association. */
812static void sctp_cmd_delete_tcb(sctp_cmd_seq_t *cmds,
813 struct sctp_association *asoc)
814{
815 struct sock *sk = asoc->base.sk;
816
817 /* If it is a non-temporary association belonging to a TCP-style
818 * listening socket that is not closed, do not free it so that accept()
819 * can pick it up later.
820 */
821 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
822 (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
823 return;
824
825 sctp_unhash_established(asoc);
826 sctp_association_free(asoc);
827}
828
829/*
830 * ADDIP Section 4.1 ASCONF Chunk Procedures
831 * A4) Start a T-4 RTO timer, using the RTO value of the selected
832 * destination address (we use active path instead of primary path just
833 * because primary path may be inactive.
834 */
835static void sctp_cmd_setup_t4(sctp_cmd_seq_t *cmds,
836 struct sctp_association *asoc,
837 struct sctp_chunk *chunk)
838{
839 struct sctp_transport *t;
840
841 t = sctp_assoc_choose_alter_transport(asoc, chunk->transport);
842 asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
843 chunk->transport = t;
844}
845
846/* Process an incoming Operation Error Chunk. */
847static void sctp_cmd_process_operr(sctp_cmd_seq_t *cmds,
848 struct sctp_association *asoc,
849 struct sctp_chunk *chunk)
850{
851 struct sctp_errhdr *err_hdr;
852 struct sctp_ulpevent *ev;
853
854 while (chunk->chunk_end > chunk->skb->data) {
855 err_hdr = (struct sctp_errhdr *)(chunk->skb->data);
856
857 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
858 GFP_ATOMIC);
859 if (!ev)
860 return;
861
862 sctp_ulpq_tail_event(&asoc->ulpq, ev);
863
864 switch (err_hdr->cause) {
865 case SCTP_ERROR_UNKNOWN_CHUNK:
866 {
867 sctp_chunkhdr_t *unk_chunk_hdr;
868
869 unk_chunk_hdr = (sctp_chunkhdr_t *)err_hdr->variable;
870 switch (unk_chunk_hdr->type) {
871 /* ADDIP 4.1 A9) If the peer responds to an ASCONF with
872 * an ERROR chunk reporting that it did not recognized
873 * the ASCONF chunk type, the sender of the ASCONF MUST
874 * NOT send any further ASCONF chunks and MUST stop its
875 * T-4 timer.
876 */
877 case SCTP_CID_ASCONF:
878 if (asoc->peer.asconf_capable == 0)
879 break;
880
881 asoc->peer.asconf_capable = 0;
882 sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
883 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
884 break;
885 default:
886 break;
887 }
888 break;
889 }
890 default:
891 break;
892 }
893 }
894}
895
896/* Process variable FWDTSN chunk information. */
897static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq,
898 struct sctp_chunk *chunk)
899{
900 struct sctp_fwdtsn_skip *skip;
901 /* Walk through all the skipped SSNs */
902 sctp_walk_fwdtsn(skip, chunk) {
903 sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
904 }
905}
906
907/* Helper function to remove the association non-primary peer
908 * transports.
909 */
910static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
911{
912 struct sctp_transport *t;
913 struct list_head *pos;
914 struct list_head *temp;
915
916 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
917 t = list_entry(pos, struct sctp_transport, transports);
918 if (!sctp_cmp_addr_exact(&t->ipaddr,
919 &asoc->peer.primary_addr)) {
920 sctp_assoc_del_peer(asoc, &t->ipaddr);
921 }
922 }
923}
924
925/* Helper function to set sk_err on a 1-1 style socket. */
926static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
927{
928 struct sock *sk = asoc->base.sk;
929
930 if (!sctp_style(sk, UDP))
931 sk->sk_err = error;
932}
933
934/* Helper function to generate an association change event */
935static void sctp_cmd_assoc_change(sctp_cmd_seq_t *commands,
936 struct sctp_association *asoc,
937 u8 state)
938{
939 struct sctp_ulpevent *ev;
940
941 ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0,
942 asoc->c.sinit_num_ostreams,
943 asoc->c.sinit_max_instreams,
944 NULL, GFP_ATOMIC);
945 if (ev)
946 sctp_ulpq_tail_event(&asoc->ulpq, ev);
947}
948
949/* Helper function to generate an adaptation indication event */
950static void sctp_cmd_adaptation_ind(sctp_cmd_seq_t *commands,
951 struct sctp_association *asoc)
952{
953 struct sctp_ulpevent *ev;
954
955 ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
956
957 if (ev)
958 sctp_ulpq_tail_event(&asoc->ulpq, ev);
959}
960
961
962static void sctp_cmd_t1_timer_update(struct sctp_association *asoc,
963 sctp_event_timeout_t timer,
964 char *name)
965{
966 struct sctp_transport *t;
967
968 t = asoc->init_last_sent_to;
969 asoc->init_err_counter++;
970
971 if (t->init_sent_count > (asoc->init_cycle + 1)) {
972 asoc->timeouts[timer] *= 2;
973 if (asoc->timeouts[timer] > asoc->max_init_timeo) {
974 asoc->timeouts[timer] = asoc->max_init_timeo;
975 }
976 asoc->init_cycle++;
977 SCTP_DEBUG_PRINTK(
978 "T1 %s Timeout adjustment"
979 " init_err_counter: %d"
980 " cycle: %d"
981 " timeout: %ld\n",
982 name,
983 asoc->init_err_counter,
984 asoc->init_cycle,
985 asoc->timeouts[timer]);
986 }
987
988}
989
990/* Send the whole message, chunk by chunk, to the outqueue.
991 * This way the whole message is queued up and bundling if
992 * encouraged for small fragments.
993 */
994static int sctp_cmd_send_msg(struct sctp_association *asoc,
995 struct sctp_datamsg *msg)
996{
997 struct sctp_chunk *chunk;
998 int error = 0;
999
1000 list_for_each_entry(chunk, &msg->chunks, frag_list) {
1001 error = sctp_outq_tail(&asoc->outqueue, chunk);
1002 if (error)
1003 break;
1004 }
1005
1006 return error;
1007}
1008
1009
1010/* Sent the next ASCONF packet currently stored in the association.
1011 * This happens after the ASCONF_ACK was succeffully processed.
1012 */
1013static void sctp_cmd_send_asconf(struct sctp_association *asoc)
1014{
1015 /* Send the next asconf chunk from the addip chunk
1016 * queue.
1017 */
1018 if (!list_empty(&asoc->addip_chunk_list)) {
1019 struct list_head *entry = asoc->addip_chunk_list.next;
1020 struct sctp_chunk *asconf = list_entry(entry,
1021 struct sctp_chunk, list);
1022 list_del_init(entry);
1023
1024 /* Hold the chunk until an ASCONF_ACK is received. */
1025 sctp_chunk_hold(asconf);
1026 if (sctp_primitive_ASCONF(asoc, asconf))
1027 sctp_chunk_free(asconf);
1028 else
1029 asoc->addip_last_asconf = asconf;
1030 }
1031}
1032
1033
1034/* These three macros allow us to pull the debugging code out of the
1035 * main flow of sctp_do_sm() to keep attention focused on the real
1036 * functionality there.
1037 */
1038#define DEBUG_PRE \
1039 SCTP_DEBUG_PRINTK("sctp_do_sm prefn: " \
1040 "ep %p, %s, %s, asoc %p[%s], %s\n", \
1041 ep, sctp_evttype_tbl[event_type], \
1042 (*debug_fn)(subtype), asoc, \
1043 sctp_state_tbl[state], state_fn->name)
1044
1045#define DEBUG_POST \
1046 SCTP_DEBUG_PRINTK("sctp_do_sm postfn: " \
1047 "asoc %p, status: %s\n", \
1048 asoc, sctp_status_tbl[status])
1049
1050#define DEBUG_POST_SFX \
1051 SCTP_DEBUG_PRINTK("sctp_do_sm post sfx: error %d, asoc %p[%s]\n", \
1052 error, asoc, \
1053 sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
1054 sctp_assoc2id(asoc)))?asoc->state:SCTP_STATE_CLOSED])
1055
1056/*
1057 * This is the master state machine processing function.
1058 *
1059 * If you want to understand all of lksctp, this is a
1060 * good place to start.
1061 */
1062int sctp_do_sm(sctp_event_t event_type, sctp_subtype_t subtype,
1063 sctp_state_t state,
1064 struct sctp_endpoint *ep,
1065 struct sctp_association *asoc,
1066 void *event_arg,
1067 gfp_t gfp)
1068{
1069 sctp_cmd_seq_t commands;
1070 const sctp_sm_table_entry_t *state_fn;
1071 sctp_disposition_t status;
1072 int error = 0;
1073 typedef const char *(printfn_t)(sctp_subtype_t);
1074
1075 static printfn_t *table[] = {
1076 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
1077 };
1078 printfn_t *debug_fn __attribute__ ((unused)) = table[event_type];
1079
1080 /* Look up the state function, run it, and then process the
1081 * side effects. These three steps are the heart of lksctp.
1082 */
1083 state_fn = sctp_sm_lookup_event(event_type, state, subtype);
1084
1085 sctp_init_cmd_seq(&commands);
1086
1087 DEBUG_PRE;
1088 status = (*state_fn->fn)(ep, asoc, subtype, event_arg, &commands);
1089 DEBUG_POST;
1090
1091 error = sctp_side_effects(event_type, subtype, state,
1092 ep, asoc, event_arg, status,
1093 &commands, gfp);
1094 DEBUG_POST_SFX;
1095
1096 return error;
1097}
1098
1099#undef DEBUG_PRE
1100#undef DEBUG_POST
1101
1102/*****************************************************************
1103 * This the master state function side effect processing function.
1104 *****************************************************************/
1105static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
1106 sctp_state_t state,
1107 struct sctp_endpoint *ep,
1108 struct sctp_association *asoc,
1109 void *event_arg,
1110 sctp_disposition_t status,
1111 sctp_cmd_seq_t *commands,
1112 gfp_t gfp)
1113{
1114 int error;
1115
1116 /* FIXME - Most of the dispositions left today would be categorized
1117 * as "exceptional" dispositions. For those dispositions, it
1118 * may not be proper to run through any of the commands at all.
1119 * For example, the command interpreter might be run only with
1120 * disposition SCTP_DISPOSITION_CONSUME.
1121 */
1122 if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
1123 ep, asoc,
1124 event_arg, status,
1125 commands, gfp)))
1126 goto bail;
1127
1128 switch (status) {
1129 case SCTP_DISPOSITION_DISCARD:
1130 SCTP_DEBUG_PRINTK("Ignored sctp protocol event - state %d, "
1131 "event_type %d, event_id %d\n",
1132 state, event_type, subtype.chunk);
1133 break;
1134
1135 case SCTP_DISPOSITION_NOMEM:
1136 /* We ran out of memory, so we need to discard this
1137 * packet.
1138 */
1139 /* BUG--we should now recover some memory, probably by
1140 * reneging...
1141 */
1142 error = -ENOMEM;
1143 break;
1144
1145 case SCTP_DISPOSITION_DELETE_TCB:
1146 /* This should now be a command. */
1147 break;
1148
1149 case SCTP_DISPOSITION_CONSUME:
1150 case SCTP_DISPOSITION_ABORT:
1151 /*
1152 * We should no longer have much work to do here as the
1153 * real work has been done as explicit commands above.
1154 */
1155 break;
1156
1157 case SCTP_DISPOSITION_VIOLATION:
1158 if (net_ratelimit())
1159 pr_err("protocol violation state %d chunkid %d\n",
1160 state, subtype.chunk);
1161 break;
1162
1163 case SCTP_DISPOSITION_NOT_IMPL:
1164 pr_warn("unimplemented feature in state %d, event_type %d, event_id %d\n",
1165 state, event_type, subtype.chunk);
1166 break;
1167
1168 case SCTP_DISPOSITION_BUG:
1169 pr_err("bug in state %d, event_type %d, event_id %d\n",
1170 state, event_type, subtype.chunk);
1171 BUG();
1172 break;
1173
1174 default:
1175 pr_err("impossible disposition %d in state %d, event_type %d, event_id %d\n",
1176 status, state, event_type, subtype.chunk);
1177 BUG();
1178 break;
1179 }
1180
1181bail:
1182 return error;
1183}
1184
1185/********************************************************************
1186 * 2nd Level Abstractions
1187 ********************************************************************/
1188
1189/* This is the side-effect interpreter. */
1190static int sctp_cmd_interpreter(sctp_event_t event_type,
1191 sctp_subtype_t subtype,
1192 sctp_state_t state,
1193 struct sctp_endpoint *ep,
1194 struct sctp_association *asoc,
1195 void *event_arg,
1196 sctp_disposition_t status,
1197 sctp_cmd_seq_t *commands,
1198 gfp_t gfp)
1199{
1200 int error = 0;
1201 int force;
1202 sctp_cmd_t *cmd;
1203 struct sctp_chunk *new_obj;
1204 struct sctp_chunk *chunk = NULL;
1205 struct sctp_packet *packet;
1206 struct timer_list *timer;
1207 unsigned long timeout;
1208 struct sctp_transport *t;
1209 struct sctp_sackhdr sackh;
1210 int local_cork = 0;
1211
1212 if (SCTP_EVENT_T_TIMEOUT != event_type)
1213 chunk = event_arg;
1214
1215 /* Note: This whole file is a huge candidate for rework.
1216 * For example, each command could either have its own handler, so
1217 * the loop would look like:
1218 * while (cmds)
1219 * cmd->handle(x, y, z)
1220 * --jgrimm
1221 */
1222 while (NULL != (cmd = sctp_next_cmd(commands))) {
1223 switch (cmd->verb) {
1224 case SCTP_CMD_NOP:
1225 /* Do nothing. */
1226 break;
1227
1228 case SCTP_CMD_NEW_ASOC:
1229 /* Register a new association. */
1230 if (local_cork) {
1231 sctp_outq_uncork(&asoc->outqueue);
1232 local_cork = 0;
1233 }
1234 asoc = cmd->obj.ptr;
1235 /* Register with the endpoint. */
1236 sctp_endpoint_add_asoc(ep, asoc);
1237 sctp_hash_established(asoc);
1238 break;
1239
1240 case SCTP_CMD_UPDATE_ASSOC:
1241 sctp_assoc_update(asoc, cmd->obj.ptr);
1242 break;
1243
1244 case SCTP_CMD_PURGE_OUTQUEUE:
1245 sctp_outq_teardown(&asoc->outqueue);
1246 break;
1247
1248 case SCTP_CMD_DELETE_TCB:
1249 if (local_cork) {
1250 sctp_outq_uncork(&asoc->outqueue);
1251 local_cork = 0;
1252 }
1253 /* Delete the current association. */
1254 sctp_cmd_delete_tcb(commands, asoc);
1255 asoc = NULL;
1256 break;
1257
1258 case SCTP_CMD_NEW_STATE:
1259 /* Enter a new state. */
1260 sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1261 break;
1262
1263 case SCTP_CMD_REPORT_TSN:
1264 /* Record the arrival of a TSN. */
1265 error = sctp_tsnmap_mark(&asoc->peer.tsn_map,
1266 cmd->obj.u32);
1267 break;
1268
1269 case SCTP_CMD_REPORT_FWDTSN:
1270 /* Move the Cumulattive TSN Ack ahead. */
1271 sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32);
1272
1273 /* purge the fragmentation queue */
1274 sctp_ulpq_reasm_flushtsn(&asoc->ulpq, cmd->obj.u32);
1275
1276 /* Abort any in progress partial delivery. */
1277 sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
1278 break;
1279
1280 case SCTP_CMD_PROCESS_FWDTSN:
1281 sctp_cmd_process_fwdtsn(&asoc->ulpq, cmd->obj.ptr);
1282 break;
1283
1284 case SCTP_CMD_GEN_SACK:
1285 /* Generate a Selective ACK.
1286 * The argument tells us whether to just count
1287 * the packet and MAYBE generate a SACK, or
1288 * force a SACK out.
1289 */
1290 force = cmd->obj.i32;
1291 error = sctp_gen_sack(asoc, force, commands);
1292 break;
1293
1294 case SCTP_CMD_PROCESS_SACK:
1295 /* Process an inbound SACK. */
1296 error = sctp_cmd_process_sack(commands, asoc,
1297 cmd->obj.ptr);
1298 break;
1299
1300 case SCTP_CMD_GEN_INIT_ACK:
1301 /* Generate an INIT ACK chunk. */
1302 new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1303 0);
1304 if (!new_obj)
1305 goto nomem;
1306
1307 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1308 SCTP_CHUNK(new_obj));
1309 break;
1310
1311 case SCTP_CMD_PEER_INIT:
1312 /* Process a unified INIT from the peer.
1313 * Note: Only used during INIT-ACK processing. If
1314 * there is an error just return to the outter
1315 * layer which will bail.
1316 */
1317 error = sctp_cmd_process_init(commands, asoc, chunk,
1318 cmd->obj.ptr, gfp);
1319 break;
1320
1321 case SCTP_CMD_GEN_COOKIE_ECHO:
1322 /* Generate a COOKIE ECHO chunk. */
1323 new_obj = sctp_make_cookie_echo(asoc, chunk);
1324 if (!new_obj) {
1325 if (cmd->obj.ptr)
1326 sctp_chunk_free(cmd->obj.ptr);
1327 goto nomem;
1328 }
1329 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1330 SCTP_CHUNK(new_obj));
1331
1332 /* If there is an ERROR chunk to be sent along with
1333 * the COOKIE_ECHO, send it, too.
1334 */
1335 if (cmd->obj.ptr)
1336 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1337 SCTP_CHUNK(cmd->obj.ptr));
1338
1339 if (new_obj->transport) {
1340 new_obj->transport->init_sent_count++;
1341 asoc->init_last_sent_to = new_obj->transport;
1342 }
1343
1344 /* FIXME - Eventually come up with a cleaner way to
1345 * enabling COOKIE-ECHO + DATA bundling during
1346 * multihoming stale cookie scenarios, the following
1347 * command plays with asoc->peer.retran_path to
1348 * avoid the problem of sending the COOKIE-ECHO and
1349 * DATA in different paths, which could result
1350 * in the association being ABORTed if the DATA chunk
1351 * is processed first by the server. Checking the
1352 * init error counter simply causes this command
1353 * to be executed only during failed attempts of
1354 * association establishment.
1355 */
1356 if ((asoc->peer.retran_path !=
1357 asoc->peer.primary_path) &&
1358 (asoc->init_err_counter > 0)) {
1359 sctp_add_cmd_sf(commands,
1360 SCTP_CMD_FORCE_PRIM_RETRAN,
1361 SCTP_NULL());
1362 }
1363
1364 break;
1365
1366 case SCTP_CMD_GEN_SHUTDOWN:
1367 /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1368 * Reset error counts.
1369 */
1370 asoc->overall_error_count = 0;
1371
1372 /* Generate a SHUTDOWN chunk. */
1373 new_obj = sctp_make_shutdown(asoc, chunk);
1374 if (!new_obj)
1375 goto nomem;
1376 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1377 SCTP_CHUNK(new_obj));
1378 break;
1379
1380 case SCTP_CMD_CHUNK_ULP:
1381 /* Send a chunk to the sockets layer. */
1382 SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1383 "chunk_up:", cmd->obj.ptr,
1384 "ulpq:", &asoc->ulpq);
1385 sctp_ulpq_tail_data(&asoc->ulpq, cmd->obj.ptr,
1386 GFP_ATOMIC);
1387 break;
1388
1389 case SCTP_CMD_EVENT_ULP:
1390 /* Send a notification to the sockets layer. */
1391 SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1392 "event_up:",cmd->obj.ptr,
1393 "ulpq:",&asoc->ulpq);
1394 sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ptr);
1395 break;
1396
1397 case SCTP_CMD_REPLY:
1398 /* If an caller has not already corked, do cork. */
1399 if (!asoc->outqueue.cork) {
1400 sctp_outq_cork(&asoc->outqueue);
1401 local_cork = 1;
1402 }
1403 /* Send a chunk to our peer. */
1404 error = sctp_outq_tail(&asoc->outqueue, cmd->obj.ptr);
1405 break;
1406
1407 case SCTP_CMD_SEND_PKT:
1408 /* Send a full packet to our peer. */
1409 packet = cmd->obj.ptr;
1410 sctp_packet_transmit(packet);
1411 sctp_ootb_pkt_free(packet);
1412 break;
1413
1414 case SCTP_CMD_T1_RETRAN:
1415 /* Mark a transport for retransmission. */
1416 sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1417 SCTP_RTXR_T1_RTX);
1418 break;
1419
1420 case SCTP_CMD_RETRAN:
1421 /* Mark a transport for retransmission. */
1422 sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1423 SCTP_RTXR_T3_RTX);
1424 break;
1425
1426 case SCTP_CMD_ECN_CE:
1427 /* Do delayed CE processing. */
1428 sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1429 break;
1430
1431 case SCTP_CMD_ECN_ECNE:
1432 /* Do delayed ECNE processing. */
1433 new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1434 chunk);
1435 if (new_obj)
1436 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1437 SCTP_CHUNK(new_obj));
1438 break;
1439
1440 case SCTP_CMD_ECN_CWR:
1441 /* Do delayed CWR processing. */
1442 sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1443 break;
1444
1445 case SCTP_CMD_SETUP_T2:
1446 sctp_cmd_setup_t2(commands, asoc, cmd->obj.ptr);
1447 break;
1448
1449 case SCTP_CMD_TIMER_START_ONCE:
1450 timer = &asoc->timers[cmd->obj.to];
1451
1452 if (timer_pending(timer))
1453 break;
1454 /* fall through */
1455
1456 case SCTP_CMD_TIMER_START:
1457 timer = &asoc->timers[cmd->obj.to];
1458 timeout = asoc->timeouts[cmd->obj.to];
1459 BUG_ON(!timeout);
1460
1461 timer->expires = jiffies + timeout;
1462 sctp_association_hold(asoc);
1463 add_timer(timer);
1464 break;
1465
1466 case SCTP_CMD_TIMER_RESTART:
1467 timer = &asoc->timers[cmd->obj.to];
1468 timeout = asoc->timeouts[cmd->obj.to];
1469 if (!mod_timer(timer, jiffies + timeout))
1470 sctp_association_hold(asoc);
1471 break;
1472
1473 case SCTP_CMD_TIMER_STOP:
1474 timer = &asoc->timers[cmd->obj.to];
1475 if (timer_pending(timer) && del_timer(timer))
1476 sctp_association_put(asoc);
1477 break;
1478
1479 case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1480 chunk = cmd->obj.ptr;
1481 t = sctp_assoc_choose_alter_transport(asoc,
1482 asoc->init_last_sent_to);
1483 asoc->init_last_sent_to = t;
1484 chunk->transport = t;
1485 t->init_sent_count++;
1486 /* Set the new transport as primary */
1487 sctp_assoc_set_primary(asoc, t);
1488 break;
1489
1490 case SCTP_CMD_INIT_RESTART:
1491 /* Do the needed accounting and updates
1492 * associated with restarting an initialization
1493 * timer. Only multiply the timeout by two if
1494 * all transports have been tried at the current
1495 * timeout.
1496 */
1497 sctp_cmd_t1_timer_update(asoc,
1498 SCTP_EVENT_TIMEOUT_T1_INIT,
1499 "INIT");
1500
1501 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1502 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1503 break;
1504
1505 case SCTP_CMD_COOKIEECHO_RESTART:
1506 /* Do the needed accounting and updates
1507 * associated with restarting an initialization
1508 * timer. Only multiply the timeout by two if
1509 * all transports have been tried at the current
1510 * timeout.
1511 */
1512 sctp_cmd_t1_timer_update(asoc,
1513 SCTP_EVENT_TIMEOUT_T1_COOKIE,
1514 "COOKIE");
1515
1516 /* If we've sent any data bundled with
1517 * COOKIE-ECHO we need to resend.
1518 */
1519 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1520 transports) {
1521 sctp_retransmit_mark(&asoc->outqueue, t,
1522 SCTP_RTXR_T1_RTX);
1523 }
1524
1525 sctp_add_cmd_sf(commands,
1526 SCTP_CMD_TIMER_RESTART,
1527 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1528 break;
1529
1530 case SCTP_CMD_INIT_FAILED:
1531 sctp_cmd_init_failed(commands, asoc, cmd->obj.err);
1532 break;
1533
1534 case SCTP_CMD_ASSOC_FAILED:
1535 sctp_cmd_assoc_failed(commands, asoc, event_type,
1536 subtype, chunk, cmd->obj.err);
1537 break;
1538
1539 case SCTP_CMD_INIT_COUNTER_INC:
1540 asoc->init_err_counter++;
1541 break;
1542
1543 case SCTP_CMD_INIT_COUNTER_RESET:
1544 asoc->init_err_counter = 0;
1545 asoc->init_cycle = 0;
1546 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1547 transports) {
1548 t->init_sent_count = 0;
1549 }
1550 break;
1551
1552 case SCTP_CMD_REPORT_DUP:
1553 sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1554 cmd->obj.u32);
1555 break;
1556
1557 case SCTP_CMD_REPORT_BAD_TAG:
1558 SCTP_DEBUG_PRINTK("vtag mismatch!\n");
1559 break;
1560
1561 case SCTP_CMD_STRIKE:
1562 /* Mark one strike against a transport. */
1563 sctp_do_8_2_transport_strike(asoc, cmd->obj.transport,
1564 0);
1565 break;
1566
1567 case SCTP_CMD_TRANSPORT_IDLE:
1568 t = cmd->obj.transport;
1569 sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
1570 break;
1571
1572 case SCTP_CMD_TRANSPORT_HB_SENT:
1573 t = cmd->obj.transport;
1574 sctp_do_8_2_transport_strike(asoc, t, 1);
1575 t->hb_sent = 1;
1576 break;
1577
1578 case SCTP_CMD_TRANSPORT_ON:
1579 t = cmd->obj.transport;
1580 sctp_cmd_transport_on(commands, asoc, t, chunk);
1581 break;
1582
1583 case SCTP_CMD_HB_TIMERS_START:
1584 sctp_cmd_hb_timers_start(commands, asoc);
1585 break;
1586
1587 case SCTP_CMD_HB_TIMER_UPDATE:
1588 t = cmd->obj.transport;
1589 sctp_cmd_hb_timer_update(commands, t);
1590 break;
1591
1592 case SCTP_CMD_HB_TIMERS_STOP:
1593 sctp_cmd_hb_timers_stop(commands, asoc);
1594 break;
1595
1596 case SCTP_CMD_REPORT_ERROR:
1597 error = cmd->obj.error;
1598 break;
1599
1600 case SCTP_CMD_PROCESS_CTSN:
1601 /* Dummy up a SACK for processing. */
1602 sackh.cum_tsn_ack = cmd->obj.be32;
1603 sackh.a_rwnd = asoc->peer.rwnd +
1604 asoc->outqueue.outstanding_bytes;
1605 sackh.num_gap_ack_blocks = 0;
1606 sackh.num_dup_tsns = 0;
1607 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1608 SCTP_SACKH(&sackh));
1609 break;
1610
1611 case SCTP_CMD_DISCARD_PACKET:
1612 /* We need to discard the whole packet.
1613 * Uncork the queue since there might be
1614 * responses pending
1615 */
1616 chunk->pdiscard = 1;
1617 if (asoc) {
1618 sctp_outq_uncork(&asoc->outqueue);
1619 local_cork = 0;
1620 }
1621 break;
1622
1623 case SCTP_CMD_RTO_PENDING:
1624 t = cmd->obj.transport;
1625 t->rto_pending = 1;
1626 break;
1627
1628 case SCTP_CMD_PART_DELIVER:
1629 sctp_ulpq_partial_delivery(&asoc->ulpq, cmd->obj.ptr,
1630 GFP_ATOMIC);
1631 break;
1632
1633 case SCTP_CMD_RENEGE:
1634 sctp_ulpq_renege(&asoc->ulpq, cmd->obj.ptr,
1635 GFP_ATOMIC);
1636 break;
1637
1638 case SCTP_CMD_SETUP_T4:
1639 sctp_cmd_setup_t4(commands, asoc, cmd->obj.ptr);
1640 break;
1641
1642 case SCTP_CMD_PROCESS_OPERR:
1643 sctp_cmd_process_operr(commands, asoc, chunk);
1644 break;
1645 case SCTP_CMD_CLEAR_INIT_TAG:
1646 asoc->peer.i.init_tag = 0;
1647 break;
1648 case SCTP_CMD_DEL_NON_PRIMARY:
1649 sctp_cmd_del_non_primary(asoc);
1650 break;
1651 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1652 sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1653 break;
1654 case SCTP_CMD_FORCE_PRIM_RETRAN:
1655 t = asoc->peer.retran_path;
1656 asoc->peer.retran_path = asoc->peer.primary_path;
1657 error = sctp_outq_uncork(&asoc->outqueue);
1658 local_cork = 0;
1659 asoc->peer.retran_path = t;
1660 break;
1661 case SCTP_CMD_SET_SK_ERR:
1662 sctp_cmd_set_sk_err(asoc, cmd->obj.error);
1663 break;
1664 case SCTP_CMD_ASSOC_CHANGE:
1665 sctp_cmd_assoc_change(commands, asoc,
1666 cmd->obj.u8);
1667 break;
1668 case SCTP_CMD_ADAPTATION_IND:
1669 sctp_cmd_adaptation_ind(commands, asoc);
1670 break;
1671
1672 case SCTP_CMD_ASSOC_SHKEY:
1673 error = sctp_auth_asoc_init_active_key(asoc,
1674 GFP_ATOMIC);
1675 break;
1676 case SCTP_CMD_UPDATE_INITTAG:
1677 asoc->peer.i.init_tag = cmd->obj.u32;
1678 break;
1679 case SCTP_CMD_SEND_MSG:
1680 if (!asoc->outqueue.cork) {
1681 sctp_outq_cork(&asoc->outqueue);
1682 local_cork = 1;
1683 }
1684 error = sctp_cmd_send_msg(asoc, cmd->obj.msg);
1685 break;
1686 case SCTP_CMD_SEND_NEXT_ASCONF:
1687 sctp_cmd_send_asconf(asoc);
1688 break;
1689 case SCTP_CMD_PURGE_ASCONF_QUEUE:
1690 sctp_asconf_queue_teardown(asoc);
1691 break;
1692
1693 case SCTP_CMD_SET_ASOC:
1694 asoc = cmd->obj.asoc;
1695 break;
1696
1697 default:
1698 pr_warn("Impossible command: %u, %p\n",
1699 cmd->verb, cmd->obj.ptr);
1700 break;
1701 }
1702
1703 if (error)
1704 break;
1705 }
1706
1707out:
1708 /* If this is in response to a received chunk, wait until
1709 * we are done with the packet to open the queue so that we don't
1710 * send multiple packets in response to a single request.
1711 */
1712 if (asoc && SCTP_EVENT_T_CHUNK == event_type && chunk) {
1713 if (chunk->end_of_packet || chunk->singleton)
1714 error = sctp_outq_uncork(&asoc->outqueue);
1715 } else if (local_cork)
1716 error = sctp_outq_uncork(&asoc->outqueue);
1717 return error;
1718nomem:
1719 error = -ENOMEM;
1720 goto out;
1721}
1722