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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, see
26 * <http://www.gnu.org/licenses/>.
27 *
28 * Please send any bug reports or fixes you make to the
29 * email address(es):
30 * lksctp developers <linux-sctp@vger.kernel.org>
31 *
32 * Written or modified by:
33 * La Monte H.P. Yarroll <piggy@acm.org>
34 * Karl Knutson <karl@athena.chicago.il.us>
35 * Jon Grimm <jgrimm@austin.ibm.com>
36 * Hui Huang <hui.huang@nokia.com>
37 * Dajiang Zhang <dajiang.zhang@nokia.com>
38 * Daisy Chang <daisyc@us.ibm.com>
39 * Sridhar Samudrala <sri@us.ibm.com>
40 * Ardelle Fan <ardelle.fan@intel.com>
41 */
42
43#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
44
45#include <linux/skbuff.h>
46#include <linux/types.h>
47#include <linux/socket.h>
48#include <linux/ip.h>
49#include <linux/gfp.h>
50#include <net/sock.h>
51#include <net/sctp/sctp.h>
52#include <net/sctp/sm.h>
53
54static int sctp_cmd_interpreter(sctp_event_t event_type,
55 sctp_subtype_t subtype,
56 sctp_state_t state,
57 struct sctp_endpoint *ep,
58 struct sctp_association *asoc,
59 void *event_arg,
60 sctp_disposition_t status,
61 sctp_cmd_seq_t *commands,
62 gfp_t gfp);
63static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
64 sctp_state_t state,
65 struct sctp_endpoint *ep,
66 struct sctp_association **asoc,
67 void *event_arg,
68 sctp_disposition_t status,
69 sctp_cmd_seq_t *commands,
70 gfp_t gfp);
71
72/********************************************************************
73 * Helper functions
74 ********************************************************************/
75
76/* A helper function for delayed processing of INET ECN CE bit. */
77static void sctp_do_ecn_ce_work(struct sctp_association *asoc,
78 __u32 lowest_tsn)
79{
80 /* Save the TSN away for comparison when we receive CWR */
81
82 asoc->last_ecne_tsn = lowest_tsn;
83 asoc->need_ecne = 1;
84}
85
86/* Helper function for delayed processing of SCTP ECNE chunk. */
87/* RFC 2960 Appendix A
88 *
89 * RFC 2481 details a specific bit for a sender to send in
90 * the header of its next outbound TCP segment to indicate to
91 * its peer that it has reduced its congestion window. This
92 * is termed the CWR bit. For SCTP the same indication is made
93 * by including the CWR chunk. This chunk contains one data
94 * element, i.e. the TSN number that was sent in the ECNE chunk.
95 * This element represents the lowest TSN number in the datagram
96 * that was originally marked with the CE bit.
97 */
98static struct sctp_chunk *sctp_do_ecn_ecne_work(struct sctp_association *asoc,
99 __u32 lowest_tsn,
100 struct sctp_chunk *chunk)
101{
102 struct sctp_chunk *repl;
103
104 /* Our previously transmitted packet ran into some congestion
105 * so we should take action by reducing cwnd and ssthresh
106 * and then ACK our peer that we we've done so by
107 * sending a CWR.
108 */
109
110 /* First, try to determine if we want to actually lower
111 * our cwnd variables. Only lower them if the ECNE looks more
112 * recent than the last response.
113 */
114 if (TSN_lt(asoc->last_cwr_tsn, lowest_tsn)) {
115 struct sctp_transport *transport;
116
117 /* Find which transport's congestion variables
118 * need to be adjusted.
119 */
120 transport = sctp_assoc_lookup_tsn(asoc, lowest_tsn);
121
122 /* Update the congestion variables. */
123 if (transport)
124 sctp_transport_lower_cwnd(transport,
125 SCTP_LOWER_CWND_ECNE);
126 asoc->last_cwr_tsn = lowest_tsn;
127 }
128
129 /* Always try to quiet the other end. In case of lost CWR,
130 * resend last_cwr_tsn.
131 */
132 repl = sctp_make_cwr(asoc, asoc->last_cwr_tsn, chunk);
133
134 /* If we run out of memory, it will look like a lost CWR. We'll
135 * get back in sync eventually.
136 */
137 return repl;
138}
139
140/* Helper function to do delayed processing of ECN CWR chunk. */
141static void sctp_do_ecn_cwr_work(struct sctp_association *asoc,
142 __u32 lowest_tsn)
143{
144 /* Turn off ECNE getting auto-prepended to every outgoing
145 * packet
146 */
147 asoc->need_ecne = 0;
148}
149
150/* Generate SACK if necessary. We call this at the end of a packet. */
151static int sctp_gen_sack(struct sctp_association *asoc, int force,
152 sctp_cmd_seq_t *commands)
153{
154 __u32 ctsn, max_tsn_seen;
155 struct sctp_chunk *sack;
156 struct sctp_transport *trans = asoc->peer.last_data_from;
157 int error = 0;
158
159 if (force ||
160 (!trans && (asoc->param_flags & SPP_SACKDELAY_DISABLE)) ||
161 (trans && (trans->param_flags & SPP_SACKDELAY_DISABLE)))
162 asoc->peer.sack_needed = 1;
163
164 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
165 max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
166
167 /* From 12.2 Parameters necessary per association (i.e. the TCB):
168 *
169 * Ack State : This flag indicates if the next received packet
170 * : is to be responded to with a SACK. ...
171 * : When DATA chunks are out of order, SACK's
172 * : are not delayed (see Section 6).
173 *
174 * [This is actually not mentioned in Section 6, but we
175 * implement it here anyway. --piggy]
176 */
177 if (max_tsn_seen != ctsn)
178 asoc->peer.sack_needed = 1;
179
180 /* From 6.2 Acknowledgement on Reception of DATA Chunks:
181 *
182 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically,
183 * an acknowledgement SHOULD be generated for at least every
184 * second packet (not every second DATA chunk) received, and
185 * SHOULD be generated within 200 ms of the arrival of any
186 * unacknowledged DATA chunk. ...
187 */
188 if (!asoc->peer.sack_needed) {
189 asoc->peer.sack_cnt++;
190
191 /* Set the SACK delay timeout based on the
192 * SACK delay for the last transport
193 * data was received from, or the default
194 * for the association.
195 */
196 if (trans) {
197 /* We will need a SACK for the next packet. */
198 if (asoc->peer.sack_cnt >= trans->sackfreq - 1)
199 asoc->peer.sack_needed = 1;
200
201 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
202 trans->sackdelay;
203 } else {
204 /* We will need a SACK for the next packet. */
205 if (asoc->peer.sack_cnt >= asoc->sackfreq - 1)
206 asoc->peer.sack_needed = 1;
207
208 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
209 asoc->sackdelay;
210 }
211
212 /* Restart the SACK timer. */
213 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
214 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
215 } else {
216 __u32 old_a_rwnd = asoc->a_rwnd;
217
218 asoc->a_rwnd = asoc->rwnd;
219 sack = sctp_make_sack(asoc);
220 if (!sack) {
221 asoc->a_rwnd = old_a_rwnd;
222 goto nomem;
223 }
224
225 asoc->peer.sack_needed = 0;
226 asoc->peer.sack_cnt = 0;
227
228 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(sack));
229
230 /* Stop the SACK timer. */
231 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
232 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
233 }
234
235 return error;
236nomem:
237 error = -ENOMEM;
238 return error;
239}
240
241/* When the T3-RTX timer expires, it calls this function to create the
242 * relevant state machine event.
243 */
244void sctp_generate_t3_rtx_event(unsigned long peer)
245{
246 int error;
247 struct sctp_transport *transport = (struct sctp_transport *) peer;
248 struct sctp_association *asoc = transport->asoc;
249 struct sock *sk = asoc->base.sk;
250 struct net *net = sock_net(sk);
251
252 /* Check whether a task is in the sock. */
253
254 bh_lock_sock(sk);
255 if (sock_owned_by_user(sk)) {
256 pr_debug("%s: sock is busy\n", __func__);
257
258 /* Try again later. */
259 if (!mod_timer(&transport->T3_rtx_timer, jiffies + (HZ/20)))
260 sctp_transport_hold(transport);
261 goto out_unlock;
262 }
263
264 /* Run through the state machine. */
265 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
266 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX),
267 asoc->state,
268 asoc->ep, asoc,
269 transport, GFP_ATOMIC);
270
271 if (error)
272 sk->sk_err = -error;
273
274out_unlock:
275 bh_unlock_sock(sk);
276 sctp_transport_put(transport);
277}
278
279/* This is a sa interface for producing timeout events. It works
280 * for timeouts which use the association as their parameter.
281 */
282static void sctp_generate_timeout_event(struct sctp_association *asoc,
283 sctp_event_timeout_t timeout_type)
284{
285 struct sock *sk = asoc->base.sk;
286 struct net *net = sock_net(sk);
287 int error = 0;
288
289 bh_lock_sock(sk);
290 if (sock_owned_by_user(sk)) {
291 pr_debug("%s: sock is busy: timer %d\n", __func__,
292 timeout_type);
293
294 /* Try again later. */
295 if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20)))
296 sctp_association_hold(asoc);
297 goto out_unlock;
298 }
299
300 /* Is this association really dead and just waiting around for
301 * the timer to let go of the reference?
302 */
303 if (asoc->base.dead)
304 goto out_unlock;
305
306 /* Run through the state machine. */
307 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
308 SCTP_ST_TIMEOUT(timeout_type),
309 asoc->state, asoc->ep, asoc,
310 (void *)timeout_type, GFP_ATOMIC);
311
312 if (error)
313 sk->sk_err = -error;
314
315out_unlock:
316 bh_unlock_sock(sk);
317 sctp_association_put(asoc);
318}
319
320static void sctp_generate_t1_cookie_event(unsigned long data)
321{
322 struct sctp_association *asoc = (struct sctp_association *) data;
323 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
324}
325
326static void sctp_generate_t1_init_event(unsigned long data)
327{
328 struct sctp_association *asoc = (struct sctp_association *) data;
329 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
330}
331
332static void sctp_generate_t2_shutdown_event(unsigned long data)
333{
334 struct sctp_association *asoc = (struct sctp_association *) data;
335 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
336}
337
338static void sctp_generate_t4_rto_event(unsigned long data)
339{
340 struct sctp_association *asoc = (struct sctp_association *) data;
341 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
342}
343
344static void sctp_generate_t5_shutdown_guard_event(unsigned long data)
345{
346 struct sctp_association *asoc = (struct sctp_association *)data;
347 sctp_generate_timeout_event(asoc,
348 SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);
349
350} /* sctp_generate_t5_shutdown_guard_event() */
351
352static void sctp_generate_autoclose_event(unsigned long data)
353{
354 struct sctp_association *asoc = (struct sctp_association *) data;
355 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE);
356}
357
358/* Generate a heart beat event. If the sock is busy, reschedule. Make
359 * sure that the transport is still valid.
360 */
361void sctp_generate_heartbeat_event(unsigned long data)
362{
363 int error = 0;
364 struct sctp_transport *transport = (struct sctp_transport *) data;
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
370 bh_lock_sock(sk);
371 if (sock_owned_by_user(sk)) {
372 pr_debug("%s: sock is busy\n", __func__);
373
374 /* Try again later. */
375 if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20)))
376 sctp_transport_hold(transport);
377 goto out_unlock;
378 }
379
380 /* Check if we should still send the heartbeat or reschedule */
381 elapsed = jiffies - transport->last_time_sent;
382 timeout = sctp_transport_timeout(transport);
383 if (elapsed < timeout) {
384 elapsed = timeout - elapsed;
385 if (!mod_timer(&transport->hb_timer, jiffies + elapsed))
386 sctp_transport_hold(transport);
387 goto out_unlock;
388 }
389
390 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
391 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
392 asoc->state, asoc->ep, asoc,
393 transport, GFP_ATOMIC);
394
395 if (error)
396 sk->sk_err = -error;
397
398out_unlock:
399 bh_unlock_sock(sk);
400 sctp_transport_put(transport);
401}
402
403/* Handle the timeout of the ICMP protocol unreachable timer. Trigger
404 * the correct state machine transition that will close the association.
405 */
406void sctp_generate_proto_unreach_event(unsigned long data)
407{
408 struct sctp_transport *transport = (struct sctp_transport *) data;
409 struct sctp_association *asoc = transport->asoc;
410 struct sock *sk = asoc->base.sk;
411 struct net *net = sock_net(sk);
412
413 bh_lock_sock(sk);
414 if (sock_owned_by_user(sk)) {
415 pr_debug("%s: sock is busy\n", __func__);
416
417 /* Try again later. */
418 if (!mod_timer(&transport->proto_unreach_timer,
419 jiffies + (HZ/20)))
420 sctp_association_hold(asoc);
421 goto out_unlock;
422 }
423
424 /* Is this structure just waiting around for us to actually
425 * get destroyed?
426 */
427 if (asoc->base.dead)
428 goto out_unlock;
429
430 sctp_do_sm(net, SCTP_EVENT_T_OTHER,
431 SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH),
432 asoc->state, asoc->ep, asoc, transport, GFP_ATOMIC);
433
434out_unlock:
435 bh_unlock_sock(sk);
436 sctp_association_put(asoc);
437}
438
439
440/* Inject a SACK Timeout event into the state machine. */
441static void sctp_generate_sack_event(unsigned long data)
442{
443 struct sctp_association *asoc = (struct sctp_association *) data;
444 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
445}
446
447sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
448 NULL,
449 sctp_generate_t1_cookie_event,
450 sctp_generate_t1_init_event,
451 sctp_generate_t2_shutdown_event,
452 NULL,
453 sctp_generate_t4_rto_event,
454 sctp_generate_t5_shutdown_guard_event,
455 NULL,
456 sctp_generate_sack_event,
457 sctp_generate_autoclose_event,
458};
459
460
461/* RFC 2960 8.2 Path Failure Detection
462 *
463 * When its peer endpoint is multi-homed, an endpoint should keep a
464 * error counter for each of the destination transport addresses of the
465 * peer endpoint.
466 *
467 * Each time the T3-rtx timer expires on any address, or when a
468 * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
469 * the error counter of that destination address will be incremented.
470 * When the value in the error counter exceeds the protocol parameter
471 * 'Path.Max.Retrans' of that destination address, the endpoint should
472 * mark the destination transport address as inactive, and a
473 * notification SHOULD be sent to the upper layer.
474 *
475 */
476static void sctp_do_8_2_transport_strike(sctp_cmd_seq_t *commands,
477 struct sctp_association *asoc,
478 struct sctp_transport *transport,
479 int is_hb)
480{
481 struct net *net = sock_net(asoc->base.sk);
482
483 /* The check for association's overall error counter exceeding the
484 * threshold is done in the state function.
485 */
486 /* We are here due to a timer expiration. If the timer was
487 * not a HEARTBEAT, then normal error tracking is done.
488 * If the timer was a heartbeat, we only increment error counts
489 * when we already have an outstanding HEARTBEAT that has not
490 * been acknowledged.
491 * Additionally, some tranport states inhibit error increments.
492 */
493 if (!is_hb) {
494 asoc->overall_error_count++;
495 if (transport->state != SCTP_INACTIVE)
496 transport->error_count++;
497 } else if (transport->hb_sent) {
498 if (transport->state != SCTP_UNCONFIRMED)
499 asoc->overall_error_count++;
500 if (transport->state != SCTP_INACTIVE)
501 transport->error_count++;
502 }
503
504 /* If the transport error count is greater than the pf_retrans
505 * threshold, and less than pathmaxrtx, and if the current state
506 * is SCTP_ACTIVE, then mark this transport as Partially Failed,
507 * see SCTP Quick Failover Draft, section 5.1
508 */
509 if (net->sctp.pf_enable &&
510 (transport->state == SCTP_ACTIVE) &&
511 (asoc->pf_retrans < transport->pathmaxrxt) &&
512 (transport->error_count > asoc->pf_retrans)) {
513
514 sctp_assoc_control_transport(asoc, transport,
515 SCTP_TRANSPORT_PF,
516 0);
517
518 /* Update the hb timer to resend a heartbeat every rto */
519 sctp_transport_reset_hb_timer(transport);
520 }
521
522 if (transport->state != SCTP_INACTIVE &&
523 (transport->error_count > transport->pathmaxrxt)) {
524 pr_debug("%s: association:%p transport addr:%pISpc failed\n",
525 __func__, asoc, &transport->ipaddr.sa);
526
527 sctp_assoc_control_transport(asoc, transport,
528 SCTP_TRANSPORT_DOWN,
529 SCTP_FAILED_THRESHOLD);
530 }
531
532 /* E2) For the destination address for which the timer
533 * expires, set RTO <- RTO * 2 ("back off the timer"). The
534 * maximum value discussed in rule C7 above (RTO.max) may be
535 * used to provide an upper bound to this doubling operation.
536 *
537 * Special Case: the first HB doesn't trigger exponential backoff.
538 * The first unacknowledged HB triggers it. We do this with a flag
539 * that indicates that we have an outstanding HB.
540 */
541 if (!is_hb || transport->hb_sent) {
542 transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
543 sctp_max_rto(asoc, transport);
544 }
545}
546
547/* Worker routine to handle INIT command failure. */
548static void sctp_cmd_init_failed(sctp_cmd_seq_t *commands,
549 struct sctp_association *asoc,
550 unsigned int error)
551{
552 struct sctp_ulpevent *event;
553
554 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_CANT_STR_ASSOC,
555 (__u16)error, 0, 0, NULL,
556 GFP_ATOMIC);
557
558 if (event)
559 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
560 SCTP_ULPEVENT(event));
561
562 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
563 SCTP_STATE(SCTP_STATE_CLOSED));
564
565 /* SEND_FAILED sent later when cleaning up the association. */
566 asoc->outqueue.error = error;
567 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
568}
569
570/* Worker routine to handle SCTP_CMD_ASSOC_FAILED. */
571static void sctp_cmd_assoc_failed(sctp_cmd_seq_t *commands,
572 struct sctp_association *asoc,
573 sctp_event_t event_type,
574 sctp_subtype_t subtype,
575 struct sctp_chunk *chunk,
576 unsigned int error)
577{
578 struct sctp_ulpevent *event;
579 struct sctp_chunk *abort;
580 /* Cancel any partial delivery in progress. */
581 sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
582
583 if (event_type == SCTP_EVENT_T_CHUNK && subtype.chunk == SCTP_CID_ABORT)
584 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
585 (__u16)error, 0, 0, chunk,
586 GFP_ATOMIC);
587 else
588 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
589 (__u16)error, 0, 0, NULL,
590 GFP_ATOMIC);
591 if (event)
592 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
593 SCTP_ULPEVENT(event));
594
595 if (asoc->overall_error_count >= asoc->max_retrans) {
596 abort = sctp_make_violation_max_retrans(asoc, chunk);
597 if (abort)
598 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
599 SCTP_CHUNK(abort));
600 }
601
602 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
603 SCTP_STATE(SCTP_STATE_CLOSED));
604
605 /* SEND_FAILED sent later when cleaning up the association. */
606 asoc->outqueue.error = error;
607 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
608}
609
610/* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
611 * inside the cookie. In reality, this is only used for INIT-ACK processing
612 * since all other cases use "temporary" associations and can do all
613 * their work in statefuns directly.
614 */
615static int sctp_cmd_process_init(sctp_cmd_seq_t *commands,
616 struct sctp_association *asoc,
617 struct sctp_chunk *chunk,
618 sctp_init_chunk_t *peer_init,
619 gfp_t gfp)
620{
621 int error;
622
623 /* We only process the init as a sideeffect in a single
624 * case. This is when we process the INIT-ACK. If we
625 * fail during INIT processing (due to malloc problems),
626 * just return the error and stop processing the stack.
627 */
628 if (!sctp_process_init(asoc, chunk, sctp_source(chunk), peer_init, gfp))
629 error = -ENOMEM;
630 else
631 error = 0;
632
633 return error;
634}
635
636/* Helper function to break out starting up of heartbeat timers. */
637static void sctp_cmd_hb_timers_start(sctp_cmd_seq_t *cmds,
638 struct sctp_association *asoc)
639{
640 struct sctp_transport *t;
641
642 /* Start a heartbeat timer for each transport on the association.
643 * hold a reference on the transport to make sure none of
644 * the needed data structures go away.
645 */
646 list_for_each_entry(t, &asoc->peer.transport_addr_list, transports)
647 sctp_transport_reset_hb_timer(t);
648}
649
650static void sctp_cmd_hb_timers_stop(sctp_cmd_seq_t *cmds,
651 struct sctp_association *asoc)
652{
653 struct sctp_transport *t;
654
655 /* Stop all heartbeat timers. */
656
657 list_for_each_entry(t, &asoc->peer.transport_addr_list,
658 transports) {
659 if (del_timer(&t->hb_timer))
660 sctp_transport_put(t);
661 }
662}
663
664/* Helper function to stop any pending T3-RTX timers */
665static void sctp_cmd_t3_rtx_timers_stop(sctp_cmd_seq_t *cmds,
666 struct sctp_association *asoc)
667{
668 struct sctp_transport *t;
669
670 list_for_each_entry(t, &asoc->peer.transport_addr_list,
671 transports) {
672 if (del_timer(&t->T3_rtx_timer))
673 sctp_transport_put(t);
674 }
675}
676
677
678/* Helper function to handle the reception of an HEARTBEAT ACK. */
679static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds,
680 struct sctp_association *asoc,
681 struct sctp_transport *t,
682 struct sctp_chunk *chunk)
683{
684 sctp_sender_hb_info_t *hbinfo;
685 int was_unconfirmed = 0;
686
687 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
688 * HEARTBEAT should clear the error counter of the destination
689 * transport address to which the HEARTBEAT was sent.
690 */
691 t->error_count = 0;
692
693 /*
694 * Although RFC4960 specifies that the overall error count must
695 * be cleared when a HEARTBEAT ACK is received, we make an
696 * exception while in SHUTDOWN PENDING. If the peer keeps its
697 * window shut forever, we may never be able to transmit our
698 * outstanding data and rely on the retransmission limit be reached
699 * to shutdown the association.
700 */
701 if (t->asoc->state < SCTP_STATE_SHUTDOWN_PENDING)
702 t->asoc->overall_error_count = 0;
703
704 /* Clear the hb_sent flag to signal that we had a good
705 * acknowledgement.
706 */
707 t->hb_sent = 0;
708
709 /* Mark the destination transport address as active if it is not so
710 * marked.
711 */
712 if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED)) {
713 was_unconfirmed = 1;
714 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
715 SCTP_HEARTBEAT_SUCCESS);
716 }
717
718 if (t->state == SCTP_PF)
719 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
720 SCTP_HEARTBEAT_SUCCESS);
721
722 /* HB-ACK was received for a the proper HB. Consider this
723 * forward progress.
724 */
725 if (t->dst)
726 dst_confirm(t->dst);
727
728 /* The receiver of the HEARTBEAT ACK should also perform an
729 * RTT measurement for that destination transport address
730 * using the time value carried in the HEARTBEAT ACK chunk.
731 * If the transport's rto_pending variable has been cleared,
732 * it was most likely due to a retransmit. However, we want
733 * to re-enable it to properly update the rto.
734 */
735 if (t->rto_pending == 0)
736 t->rto_pending = 1;
737
738 hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
739 sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
740
741 /* Update the heartbeat timer. */
742 sctp_transport_reset_hb_timer(t);
743
744 if (was_unconfirmed && asoc->peer.transport_count == 1)
745 sctp_transport_immediate_rtx(t);
746}
747
748
749/* Helper function to process the process SACK command. */
750static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds,
751 struct sctp_association *asoc,
752 struct sctp_chunk *chunk)
753{
754 int err = 0;
755
756 if (sctp_outq_sack(&asoc->outqueue, chunk)) {
757 struct net *net = sock_net(asoc->base.sk);
758
759 /* There are no more TSNs awaiting SACK. */
760 err = sctp_do_sm(net, SCTP_EVENT_T_OTHER,
761 SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
762 asoc->state, asoc->ep, asoc, NULL,
763 GFP_ATOMIC);
764 }
765
766 return err;
767}
768
769/* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
770 * the transport for a shutdown chunk.
771 */
772static void sctp_cmd_setup_t2(sctp_cmd_seq_t *cmds,
773 struct sctp_association *asoc,
774 struct sctp_chunk *chunk)
775{
776 struct sctp_transport *t;
777
778 if (chunk->transport)
779 t = chunk->transport;
780 else {
781 t = sctp_assoc_choose_alter_transport(asoc,
782 asoc->shutdown_last_sent_to);
783 chunk->transport = t;
784 }
785 asoc->shutdown_last_sent_to = t;
786 asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
787}
788
789/* Helper function to change the state of an association. */
790static void sctp_cmd_new_state(sctp_cmd_seq_t *cmds,
791 struct sctp_association *asoc,
792 sctp_state_t state)
793{
794 struct sock *sk = asoc->base.sk;
795
796 asoc->state = state;
797
798 pr_debug("%s: asoc:%p[%s]\n", __func__, asoc, sctp_state_tbl[state]);
799
800 if (sctp_style(sk, TCP)) {
801 /* Change the sk->sk_state of a TCP-style socket that has
802 * successfully completed a connect() call.
803 */
804 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
805 sk->sk_state = SCTP_SS_ESTABLISHED;
806
807 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
808 if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
809 sctp_sstate(sk, ESTABLISHED))
810 sk->sk_shutdown |= RCV_SHUTDOWN;
811 }
812
813 if (sctp_state(asoc, COOKIE_WAIT)) {
814 /* Reset init timeouts since they may have been
815 * increased due to timer expirations.
816 */
817 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
818 asoc->rto_initial;
819 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
820 asoc->rto_initial;
821 }
822
823 if (sctp_state(asoc, ESTABLISHED) ||
824 sctp_state(asoc, CLOSED) ||
825 sctp_state(asoc, SHUTDOWN_RECEIVED)) {
826 /* Wake up any processes waiting in the asoc's wait queue in
827 * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
828 */
829 if (waitqueue_active(&asoc->wait))
830 wake_up_interruptible(&asoc->wait);
831
832 /* Wake up any processes waiting in the sk's sleep queue of
833 * a TCP-style or UDP-style peeled-off socket in
834 * sctp_wait_for_accept() or sctp_wait_for_packet().
835 * For a UDP-style socket, the waiters are woken up by the
836 * notifications.
837 */
838 if (!sctp_style(sk, UDP))
839 sk->sk_state_change(sk);
840 }
841}
842
843/* Helper function to delete an association. */
844static void sctp_cmd_delete_tcb(sctp_cmd_seq_t *cmds,
845 struct sctp_association *asoc)
846{
847 struct sock *sk = asoc->base.sk;
848
849 /* If it is a non-temporary association belonging to a TCP-style
850 * listening socket that is not closed, do not free it so that accept()
851 * can pick it up later.
852 */
853 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
854 (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
855 return;
856
857 sctp_association_free(asoc);
858}
859
860/*
861 * ADDIP Section 4.1 ASCONF Chunk Procedures
862 * A4) Start a T-4 RTO timer, using the RTO value of the selected
863 * destination address (we use active path instead of primary path just
864 * because primary path may be inactive.
865 */
866static void sctp_cmd_setup_t4(sctp_cmd_seq_t *cmds,
867 struct sctp_association *asoc,
868 struct sctp_chunk *chunk)
869{
870 struct sctp_transport *t;
871
872 t = sctp_assoc_choose_alter_transport(asoc, chunk->transport);
873 asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
874 chunk->transport = t;
875}
876
877/* Process an incoming Operation Error Chunk. */
878static void sctp_cmd_process_operr(sctp_cmd_seq_t *cmds,
879 struct sctp_association *asoc,
880 struct sctp_chunk *chunk)
881{
882 struct sctp_errhdr *err_hdr;
883 struct sctp_ulpevent *ev;
884
885 while (chunk->chunk_end > chunk->skb->data) {
886 err_hdr = (struct sctp_errhdr *)(chunk->skb->data);
887
888 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
889 GFP_ATOMIC);
890 if (!ev)
891 return;
892
893 sctp_ulpq_tail_event(&asoc->ulpq, ev);
894
895 switch (err_hdr->cause) {
896 case SCTP_ERROR_UNKNOWN_CHUNK:
897 {
898 sctp_chunkhdr_t *unk_chunk_hdr;
899
900 unk_chunk_hdr = (sctp_chunkhdr_t *)err_hdr->variable;
901 switch (unk_chunk_hdr->type) {
902 /* ADDIP 4.1 A9) If the peer responds to an ASCONF with
903 * an ERROR chunk reporting that it did not recognized
904 * the ASCONF chunk type, the sender of the ASCONF MUST
905 * NOT send any further ASCONF chunks and MUST stop its
906 * T-4 timer.
907 */
908 case SCTP_CID_ASCONF:
909 if (asoc->peer.asconf_capable == 0)
910 break;
911
912 asoc->peer.asconf_capable = 0;
913 sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
914 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
915 break;
916 default:
917 break;
918 }
919 break;
920 }
921 default:
922 break;
923 }
924 }
925}
926
927/* Process variable FWDTSN chunk information. */
928static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq,
929 struct sctp_chunk *chunk)
930{
931 struct sctp_fwdtsn_skip *skip;
932 /* Walk through all the skipped SSNs */
933 sctp_walk_fwdtsn(skip, chunk) {
934 sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
935 }
936}
937
938/* Helper function to remove the association non-primary peer
939 * transports.
940 */
941static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
942{
943 struct sctp_transport *t;
944 struct list_head *pos;
945 struct list_head *temp;
946
947 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
948 t = list_entry(pos, struct sctp_transport, transports);
949 if (!sctp_cmp_addr_exact(&t->ipaddr,
950 &asoc->peer.primary_addr)) {
951 sctp_assoc_rm_peer(asoc, t);
952 }
953 }
954}
955
956/* Helper function to set sk_err on a 1-1 style socket. */
957static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
958{
959 struct sock *sk = asoc->base.sk;
960
961 if (!sctp_style(sk, UDP))
962 sk->sk_err = error;
963}
964
965/* Helper function to generate an association change event */
966static void sctp_cmd_assoc_change(sctp_cmd_seq_t *commands,
967 struct sctp_association *asoc,
968 u8 state)
969{
970 struct sctp_ulpevent *ev;
971
972 ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0,
973 asoc->c.sinit_num_ostreams,
974 asoc->c.sinit_max_instreams,
975 NULL, GFP_ATOMIC);
976 if (ev)
977 sctp_ulpq_tail_event(&asoc->ulpq, ev);
978}
979
980/* Helper function to generate an adaptation indication event */
981static void sctp_cmd_adaptation_ind(sctp_cmd_seq_t *commands,
982 struct sctp_association *asoc)
983{
984 struct sctp_ulpevent *ev;
985
986 ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
987
988 if (ev)
989 sctp_ulpq_tail_event(&asoc->ulpq, ev);
990}
991
992
993static void sctp_cmd_t1_timer_update(struct sctp_association *asoc,
994 sctp_event_timeout_t timer,
995 char *name)
996{
997 struct sctp_transport *t;
998
999 t = asoc->init_last_sent_to;
1000 asoc->init_err_counter++;
1001
1002 if (t->init_sent_count > (asoc->init_cycle + 1)) {
1003 asoc->timeouts[timer] *= 2;
1004 if (asoc->timeouts[timer] > asoc->max_init_timeo) {
1005 asoc->timeouts[timer] = asoc->max_init_timeo;
1006 }
1007 asoc->init_cycle++;
1008
1009 pr_debug("%s: T1[%s] timeout adjustment init_err_counter:%d"
1010 " cycle:%d timeout:%ld\n", __func__, name,
1011 asoc->init_err_counter, asoc->init_cycle,
1012 asoc->timeouts[timer]);
1013 }
1014
1015}
1016
1017/* Send the whole message, chunk by chunk, to the outqueue.
1018 * This way the whole message is queued up and bundling if
1019 * encouraged for small fragments.
1020 */
1021static int sctp_cmd_send_msg(struct sctp_association *asoc,
1022 struct sctp_datamsg *msg, gfp_t gfp)
1023{
1024 struct sctp_chunk *chunk;
1025 int error = 0;
1026
1027 list_for_each_entry(chunk, &msg->chunks, frag_list) {
1028 error = sctp_outq_tail(&asoc->outqueue, chunk, gfp);
1029 if (error)
1030 break;
1031 }
1032
1033 return error;
1034}
1035
1036
1037/* Sent the next ASCONF packet currently stored in the association.
1038 * This happens after the ASCONF_ACK was succeffully processed.
1039 */
1040static void sctp_cmd_send_asconf(struct sctp_association *asoc)
1041{
1042 struct net *net = sock_net(asoc->base.sk);
1043
1044 /* Send the next asconf chunk from the addip chunk
1045 * queue.
1046 */
1047 if (!list_empty(&asoc->addip_chunk_list)) {
1048 struct list_head *entry = asoc->addip_chunk_list.next;
1049 struct sctp_chunk *asconf = list_entry(entry,
1050 struct sctp_chunk, list);
1051 list_del_init(entry);
1052
1053 /* Hold the chunk until an ASCONF_ACK is received. */
1054 sctp_chunk_hold(asconf);
1055 if (sctp_primitive_ASCONF(net, asoc, asconf))
1056 sctp_chunk_free(asconf);
1057 else
1058 asoc->addip_last_asconf = asconf;
1059 }
1060}
1061
1062
1063/* These three macros allow us to pull the debugging code out of the
1064 * main flow of sctp_do_sm() to keep attention focused on the real
1065 * functionality there.
1066 */
1067#define debug_pre_sfn() \
1068 pr_debug("%s[pre-fn]: ep:%p, %s, %s, asoc:%p[%s], %s\n", __func__, \
1069 ep, sctp_evttype_tbl[event_type], (*debug_fn)(subtype), \
1070 asoc, sctp_state_tbl[state], state_fn->name)
1071
1072#define debug_post_sfn() \
1073 pr_debug("%s[post-fn]: asoc:%p, status:%s\n", __func__, asoc, \
1074 sctp_status_tbl[status])
1075
1076#define debug_post_sfx() \
1077 pr_debug("%s[post-sfx]: error:%d, asoc:%p[%s]\n", __func__, error, \
1078 asoc, sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
1079 sctp_assoc2id(asoc))) ? asoc->state : SCTP_STATE_CLOSED])
1080
1081/*
1082 * This is the master state machine processing function.
1083 *
1084 * If you want to understand all of lksctp, this is a
1085 * good place to start.
1086 */
1087int sctp_do_sm(struct net *net, sctp_event_t event_type, sctp_subtype_t subtype,
1088 sctp_state_t state,
1089 struct sctp_endpoint *ep,
1090 struct sctp_association *asoc,
1091 void *event_arg,
1092 gfp_t gfp)
1093{
1094 sctp_cmd_seq_t commands;
1095 const sctp_sm_table_entry_t *state_fn;
1096 sctp_disposition_t status;
1097 int error = 0;
1098 typedef const char *(printfn_t)(sctp_subtype_t);
1099 static printfn_t *table[] = {
1100 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
1101 };
1102 printfn_t *debug_fn __attribute__ ((unused)) = table[event_type];
1103
1104 /* Look up the state function, run it, and then process the
1105 * side effects. These three steps are the heart of lksctp.
1106 */
1107 state_fn = sctp_sm_lookup_event(net, event_type, state, subtype);
1108
1109 sctp_init_cmd_seq(&commands);
1110
1111 debug_pre_sfn();
1112 status = state_fn->fn(net, ep, asoc, subtype, event_arg, &commands);
1113 debug_post_sfn();
1114
1115 error = sctp_side_effects(event_type, subtype, state,
1116 ep, &asoc, event_arg, status,
1117 &commands, gfp);
1118 debug_post_sfx();
1119
1120 return error;
1121}
1122
1123/*****************************************************************
1124 * This the master state function side effect processing function.
1125 *****************************************************************/
1126static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
1127 sctp_state_t state,
1128 struct sctp_endpoint *ep,
1129 struct sctp_association **asoc,
1130 void *event_arg,
1131 sctp_disposition_t status,
1132 sctp_cmd_seq_t *commands,
1133 gfp_t gfp)
1134{
1135 int error;
1136
1137 /* FIXME - Most of the dispositions left today would be categorized
1138 * as "exceptional" dispositions. For those dispositions, it
1139 * may not be proper to run through any of the commands at all.
1140 * For example, the command interpreter might be run only with
1141 * disposition SCTP_DISPOSITION_CONSUME.
1142 */
1143 if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
1144 ep, *asoc,
1145 event_arg, status,
1146 commands, gfp)))
1147 goto bail;
1148
1149 switch (status) {
1150 case SCTP_DISPOSITION_DISCARD:
1151 pr_debug("%s: ignored sctp protocol event - state:%d, "
1152 "event_type:%d, event_id:%d\n", __func__, state,
1153 event_type, subtype.chunk);
1154 break;
1155
1156 case SCTP_DISPOSITION_NOMEM:
1157 /* We ran out of memory, so we need to discard this
1158 * packet.
1159 */
1160 /* BUG--we should now recover some memory, probably by
1161 * reneging...
1162 */
1163 error = -ENOMEM;
1164 break;
1165
1166 case SCTP_DISPOSITION_DELETE_TCB:
1167 case SCTP_DISPOSITION_ABORT:
1168 /* This should now be a command. */
1169 *asoc = NULL;
1170 break;
1171
1172 case SCTP_DISPOSITION_CONSUME:
1173 /*
1174 * We should no longer have much work to do here as the
1175 * real work has been done as explicit commands above.
1176 */
1177 break;
1178
1179 case SCTP_DISPOSITION_VIOLATION:
1180 net_err_ratelimited("protocol violation state %d chunkid %d\n",
1181 state, subtype.chunk);
1182 break;
1183
1184 case SCTP_DISPOSITION_NOT_IMPL:
1185 pr_warn("unimplemented feature in state %d, event_type %d, event_id %d\n",
1186 state, event_type, subtype.chunk);
1187 break;
1188
1189 case SCTP_DISPOSITION_BUG:
1190 pr_err("bug in state %d, event_type %d, event_id %d\n",
1191 state, event_type, subtype.chunk);
1192 BUG();
1193 break;
1194
1195 default:
1196 pr_err("impossible disposition %d in state %d, event_type %d, event_id %d\n",
1197 status, state, event_type, subtype.chunk);
1198 BUG();
1199 break;
1200 }
1201
1202bail:
1203 return error;
1204}
1205
1206/********************************************************************
1207 * 2nd Level Abstractions
1208 ********************************************************************/
1209
1210/* This is the side-effect interpreter. */
1211static int sctp_cmd_interpreter(sctp_event_t event_type,
1212 sctp_subtype_t subtype,
1213 sctp_state_t state,
1214 struct sctp_endpoint *ep,
1215 struct sctp_association *asoc,
1216 void *event_arg,
1217 sctp_disposition_t status,
1218 sctp_cmd_seq_t *commands,
1219 gfp_t gfp)
1220{
1221 int error = 0;
1222 int force;
1223 sctp_cmd_t *cmd;
1224 struct sctp_chunk *new_obj;
1225 struct sctp_chunk *chunk = NULL;
1226 struct sctp_packet *packet;
1227 struct timer_list *timer;
1228 unsigned long timeout;
1229 struct sctp_transport *t;
1230 struct sctp_sackhdr sackh;
1231 int local_cork = 0;
1232
1233 if (SCTP_EVENT_T_TIMEOUT != event_type)
1234 chunk = event_arg;
1235
1236 /* Note: This whole file is a huge candidate for rework.
1237 * For example, each command could either have its own handler, so
1238 * the loop would look like:
1239 * while (cmds)
1240 * cmd->handle(x, y, z)
1241 * --jgrimm
1242 */
1243 while (NULL != (cmd = sctp_next_cmd(commands))) {
1244 switch (cmd->verb) {
1245 case SCTP_CMD_NOP:
1246 /* Do nothing. */
1247 break;
1248
1249 case SCTP_CMD_NEW_ASOC:
1250 /* Register a new association. */
1251 if (local_cork) {
1252 sctp_outq_uncork(&asoc->outqueue, gfp);
1253 local_cork = 0;
1254 }
1255
1256 /* Register with the endpoint. */
1257 asoc = cmd->obj.asoc;
1258 BUG_ON(asoc->peer.primary_path == NULL);
1259 sctp_endpoint_add_asoc(ep, asoc);
1260 break;
1261
1262 case SCTP_CMD_UPDATE_ASSOC:
1263 sctp_assoc_update(asoc, cmd->obj.asoc);
1264 break;
1265
1266 case SCTP_CMD_PURGE_OUTQUEUE:
1267 sctp_outq_teardown(&asoc->outqueue);
1268 break;
1269
1270 case SCTP_CMD_DELETE_TCB:
1271 if (local_cork) {
1272 sctp_outq_uncork(&asoc->outqueue, gfp);
1273 local_cork = 0;
1274 }
1275 /* Delete the current association. */
1276 sctp_cmd_delete_tcb(commands, asoc);
1277 asoc = NULL;
1278 break;
1279
1280 case SCTP_CMD_NEW_STATE:
1281 /* Enter a new state. */
1282 sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1283 break;
1284
1285 case SCTP_CMD_REPORT_TSN:
1286 /* Record the arrival of a TSN. */
1287 error = sctp_tsnmap_mark(&asoc->peer.tsn_map,
1288 cmd->obj.u32, NULL);
1289 break;
1290
1291 case SCTP_CMD_REPORT_FWDTSN:
1292 /* Move the Cumulattive TSN Ack ahead. */
1293 sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32);
1294
1295 /* purge the fragmentation queue */
1296 sctp_ulpq_reasm_flushtsn(&asoc->ulpq, cmd->obj.u32);
1297
1298 /* Abort any in progress partial delivery. */
1299 sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
1300 break;
1301
1302 case SCTP_CMD_PROCESS_FWDTSN:
1303 sctp_cmd_process_fwdtsn(&asoc->ulpq, cmd->obj.chunk);
1304 break;
1305
1306 case SCTP_CMD_GEN_SACK:
1307 /* Generate a Selective ACK.
1308 * The argument tells us whether to just count
1309 * the packet and MAYBE generate a SACK, or
1310 * force a SACK out.
1311 */
1312 force = cmd->obj.i32;
1313 error = sctp_gen_sack(asoc, force, commands);
1314 break;
1315
1316 case SCTP_CMD_PROCESS_SACK:
1317 /* Process an inbound SACK. */
1318 error = sctp_cmd_process_sack(commands, asoc,
1319 cmd->obj.chunk);
1320 break;
1321
1322 case SCTP_CMD_GEN_INIT_ACK:
1323 /* Generate an INIT ACK chunk. */
1324 new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1325 0);
1326 if (!new_obj)
1327 goto nomem;
1328
1329 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1330 SCTP_CHUNK(new_obj));
1331 break;
1332
1333 case SCTP_CMD_PEER_INIT:
1334 /* Process a unified INIT from the peer.
1335 * Note: Only used during INIT-ACK processing. If
1336 * there is an error just return to the outter
1337 * layer which will bail.
1338 */
1339 error = sctp_cmd_process_init(commands, asoc, chunk,
1340 cmd->obj.init, gfp);
1341 break;
1342
1343 case SCTP_CMD_GEN_COOKIE_ECHO:
1344 /* Generate a COOKIE ECHO chunk. */
1345 new_obj = sctp_make_cookie_echo(asoc, chunk);
1346 if (!new_obj) {
1347 if (cmd->obj.chunk)
1348 sctp_chunk_free(cmd->obj.chunk);
1349 goto nomem;
1350 }
1351 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1352 SCTP_CHUNK(new_obj));
1353
1354 /* If there is an ERROR chunk to be sent along with
1355 * the COOKIE_ECHO, send it, too.
1356 */
1357 if (cmd->obj.chunk)
1358 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1359 SCTP_CHUNK(cmd->obj.chunk));
1360
1361 if (new_obj->transport) {
1362 new_obj->transport->init_sent_count++;
1363 asoc->init_last_sent_to = new_obj->transport;
1364 }
1365
1366 /* FIXME - Eventually come up with a cleaner way to
1367 * enabling COOKIE-ECHO + DATA bundling during
1368 * multihoming stale cookie scenarios, the following
1369 * command plays with asoc->peer.retran_path to
1370 * avoid the problem of sending the COOKIE-ECHO and
1371 * DATA in different paths, which could result
1372 * in the association being ABORTed if the DATA chunk
1373 * is processed first by the server. Checking the
1374 * init error counter simply causes this command
1375 * to be executed only during failed attempts of
1376 * association establishment.
1377 */
1378 if ((asoc->peer.retran_path !=
1379 asoc->peer.primary_path) &&
1380 (asoc->init_err_counter > 0)) {
1381 sctp_add_cmd_sf(commands,
1382 SCTP_CMD_FORCE_PRIM_RETRAN,
1383 SCTP_NULL());
1384 }
1385
1386 break;
1387
1388 case SCTP_CMD_GEN_SHUTDOWN:
1389 /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1390 * Reset error counts.
1391 */
1392 asoc->overall_error_count = 0;
1393
1394 /* Generate a SHUTDOWN chunk. */
1395 new_obj = sctp_make_shutdown(asoc, chunk);
1396 if (!new_obj)
1397 goto nomem;
1398 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1399 SCTP_CHUNK(new_obj));
1400 break;
1401
1402 case SCTP_CMD_CHUNK_ULP:
1403 /* Send a chunk to the sockets layer. */
1404 pr_debug("%s: sm_sideff: chunk_up:%p, ulpq:%p\n",
1405 __func__, cmd->obj.chunk, &asoc->ulpq);
1406
1407 sctp_ulpq_tail_data(&asoc->ulpq, cmd->obj.chunk,
1408 GFP_ATOMIC);
1409 break;
1410
1411 case SCTP_CMD_EVENT_ULP:
1412 /* Send a notification to the sockets layer. */
1413 pr_debug("%s: sm_sideff: event_up:%p, ulpq:%p\n",
1414 __func__, cmd->obj.ulpevent, &asoc->ulpq);
1415
1416 sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ulpevent);
1417 break;
1418
1419 case SCTP_CMD_REPLY:
1420 /* If an caller has not already corked, do cork. */
1421 if (!asoc->outqueue.cork) {
1422 sctp_outq_cork(&asoc->outqueue);
1423 local_cork = 1;
1424 }
1425 /* Send a chunk to our peer. */
1426 error = sctp_outq_tail(&asoc->outqueue, cmd->obj.chunk,
1427 gfp);
1428 break;
1429
1430 case SCTP_CMD_SEND_PKT:
1431 /* Send a full packet to our peer. */
1432 packet = cmd->obj.packet;
1433 sctp_packet_transmit(packet, gfp);
1434 sctp_ootb_pkt_free(packet);
1435 break;
1436
1437 case SCTP_CMD_T1_RETRAN:
1438 /* Mark a transport for retransmission. */
1439 sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1440 SCTP_RTXR_T1_RTX);
1441 break;
1442
1443 case SCTP_CMD_RETRAN:
1444 /* Mark a transport for retransmission. */
1445 sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1446 SCTP_RTXR_T3_RTX);
1447 break;
1448
1449 case SCTP_CMD_ECN_CE:
1450 /* Do delayed CE processing. */
1451 sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1452 break;
1453
1454 case SCTP_CMD_ECN_ECNE:
1455 /* Do delayed ECNE processing. */
1456 new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1457 chunk);
1458 if (new_obj)
1459 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1460 SCTP_CHUNK(new_obj));
1461 break;
1462
1463 case SCTP_CMD_ECN_CWR:
1464 /* Do delayed CWR processing. */
1465 sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1466 break;
1467
1468 case SCTP_CMD_SETUP_T2:
1469 sctp_cmd_setup_t2(commands, asoc, cmd->obj.chunk);
1470 break;
1471
1472 case SCTP_CMD_TIMER_START_ONCE:
1473 timer = &asoc->timers[cmd->obj.to];
1474
1475 if (timer_pending(timer))
1476 break;
1477 /* fall through */
1478
1479 case SCTP_CMD_TIMER_START:
1480 timer = &asoc->timers[cmd->obj.to];
1481 timeout = asoc->timeouts[cmd->obj.to];
1482 BUG_ON(!timeout);
1483
1484 timer->expires = jiffies + timeout;
1485 sctp_association_hold(asoc);
1486 add_timer(timer);
1487 break;
1488
1489 case SCTP_CMD_TIMER_RESTART:
1490 timer = &asoc->timers[cmd->obj.to];
1491 timeout = asoc->timeouts[cmd->obj.to];
1492 if (!mod_timer(timer, jiffies + timeout))
1493 sctp_association_hold(asoc);
1494 break;
1495
1496 case SCTP_CMD_TIMER_STOP:
1497 timer = &asoc->timers[cmd->obj.to];
1498 if (del_timer(timer))
1499 sctp_association_put(asoc);
1500 break;
1501
1502 case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1503 chunk = cmd->obj.chunk;
1504 t = sctp_assoc_choose_alter_transport(asoc,
1505 asoc->init_last_sent_to);
1506 asoc->init_last_sent_to = t;
1507 chunk->transport = t;
1508 t->init_sent_count++;
1509 /* Set the new transport as primary */
1510 sctp_assoc_set_primary(asoc, t);
1511 break;
1512
1513 case SCTP_CMD_INIT_RESTART:
1514 /* Do the needed accounting and updates
1515 * associated with restarting an initialization
1516 * timer. Only multiply the timeout by two if
1517 * all transports have been tried at the current
1518 * timeout.
1519 */
1520 sctp_cmd_t1_timer_update(asoc,
1521 SCTP_EVENT_TIMEOUT_T1_INIT,
1522 "INIT");
1523
1524 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1525 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1526 break;
1527
1528 case SCTP_CMD_COOKIEECHO_RESTART:
1529 /* Do the needed accounting and updates
1530 * associated with restarting an initialization
1531 * timer. Only multiply the timeout by two if
1532 * all transports have been tried at the current
1533 * timeout.
1534 */
1535 sctp_cmd_t1_timer_update(asoc,
1536 SCTP_EVENT_TIMEOUT_T1_COOKIE,
1537 "COOKIE");
1538
1539 /* If we've sent any data bundled with
1540 * COOKIE-ECHO we need to resend.
1541 */
1542 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1543 transports) {
1544 sctp_retransmit_mark(&asoc->outqueue, t,
1545 SCTP_RTXR_T1_RTX);
1546 }
1547
1548 sctp_add_cmd_sf(commands,
1549 SCTP_CMD_TIMER_RESTART,
1550 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1551 break;
1552
1553 case SCTP_CMD_INIT_FAILED:
1554 sctp_cmd_init_failed(commands, asoc, cmd->obj.err);
1555 break;
1556
1557 case SCTP_CMD_ASSOC_FAILED:
1558 sctp_cmd_assoc_failed(commands, asoc, event_type,
1559 subtype, chunk, cmd->obj.err);
1560 break;
1561
1562 case SCTP_CMD_INIT_COUNTER_INC:
1563 asoc->init_err_counter++;
1564 break;
1565
1566 case SCTP_CMD_INIT_COUNTER_RESET:
1567 asoc->init_err_counter = 0;
1568 asoc->init_cycle = 0;
1569 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1570 transports) {
1571 t->init_sent_count = 0;
1572 }
1573 break;
1574
1575 case SCTP_CMD_REPORT_DUP:
1576 sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1577 cmd->obj.u32);
1578 break;
1579
1580 case SCTP_CMD_REPORT_BAD_TAG:
1581 pr_debug("%s: vtag mismatch!\n", __func__);
1582 break;
1583
1584 case SCTP_CMD_STRIKE:
1585 /* Mark one strike against a transport. */
1586 sctp_do_8_2_transport_strike(commands, asoc,
1587 cmd->obj.transport, 0);
1588 break;
1589
1590 case SCTP_CMD_TRANSPORT_IDLE:
1591 t = cmd->obj.transport;
1592 sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
1593 break;
1594
1595 case SCTP_CMD_TRANSPORT_HB_SENT:
1596 t = cmd->obj.transport;
1597 sctp_do_8_2_transport_strike(commands, asoc,
1598 t, 1);
1599 t->hb_sent = 1;
1600 break;
1601
1602 case SCTP_CMD_TRANSPORT_ON:
1603 t = cmd->obj.transport;
1604 sctp_cmd_transport_on(commands, asoc, t, chunk);
1605 break;
1606
1607 case SCTP_CMD_HB_TIMERS_START:
1608 sctp_cmd_hb_timers_start(commands, asoc);
1609 break;
1610
1611 case SCTP_CMD_HB_TIMER_UPDATE:
1612 t = cmd->obj.transport;
1613 sctp_transport_reset_hb_timer(t);
1614 break;
1615
1616 case SCTP_CMD_HB_TIMERS_STOP:
1617 sctp_cmd_hb_timers_stop(commands, asoc);
1618 break;
1619
1620 case SCTP_CMD_REPORT_ERROR:
1621 error = cmd->obj.error;
1622 break;
1623
1624 case SCTP_CMD_PROCESS_CTSN:
1625 /* Dummy up a SACK for processing. */
1626 sackh.cum_tsn_ack = cmd->obj.be32;
1627 sackh.a_rwnd = asoc->peer.rwnd +
1628 asoc->outqueue.outstanding_bytes;
1629 sackh.num_gap_ack_blocks = 0;
1630 sackh.num_dup_tsns = 0;
1631 chunk->subh.sack_hdr = &sackh;
1632 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1633 SCTP_CHUNK(chunk));
1634 break;
1635
1636 case SCTP_CMD_DISCARD_PACKET:
1637 /* We need to discard the whole packet.
1638 * Uncork the queue since there might be
1639 * responses pending
1640 */
1641 chunk->pdiscard = 1;
1642 if (asoc) {
1643 sctp_outq_uncork(&asoc->outqueue, gfp);
1644 local_cork = 0;
1645 }
1646 break;
1647
1648 case SCTP_CMD_RTO_PENDING:
1649 t = cmd->obj.transport;
1650 t->rto_pending = 1;
1651 break;
1652
1653 case SCTP_CMD_PART_DELIVER:
1654 sctp_ulpq_partial_delivery(&asoc->ulpq, GFP_ATOMIC);
1655 break;
1656
1657 case SCTP_CMD_RENEGE:
1658 sctp_ulpq_renege(&asoc->ulpq, cmd->obj.chunk,
1659 GFP_ATOMIC);
1660 break;
1661
1662 case SCTP_CMD_SETUP_T4:
1663 sctp_cmd_setup_t4(commands, asoc, cmd->obj.chunk);
1664 break;
1665
1666 case SCTP_CMD_PROCESS_OPERR:
1667 sctp_cmd_process_operr(commands, asoc, chunk);
1668 break;
1669 case SCTP_CMD_CLEAR_INIT_TAG:
1670 asoc->peer.i.init_tag = 0;
1671 break;
1672 case SCTP_CMD_DEL_NON_PRIMARY:
1673 sctp_cmd_del_non_primary(asoc);
1674 break;
1675 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1676 sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1677 break;
1678 case SCTP_CMD_FORCE_PRIM_RETRAN:
1679 t = asoc->peer.retran_path;
1680 asoc->peer.retran_path = asoc->peer.primary_path;
1681 error = sctp_outq_uncork(&asoc->outqueue, gfp);
1682 local_cork = 0;
1683 asoc->peer.retran_path = t;
1684 break;
1685 case SCTP_CMD_SET_SK_ERR:
1686 sctp_cmd_set_sk_err(asoc, cmd->obj.error);
1687 break;
1688 case SCTP_CMD_ASSOC_CHANGE:
1689 sctp_cmd_assoc_change(commands, asoc,
1690 cmd->obj.u8);
1691 break;
1692 case SCTP_CMD_ADAPTATION_IND:
1693 sctp_cmd_adaptation_ind(commands, asoc);
1694 break;
1695
1696 case SCTP_CMD_ASSOC_SHKEY:
1697 error = sctp_auth_asoc_init_active_key(asoc,
1698 GFP_ATOMIC);
1699 break;
1700 case SCTP_CMD_UPDATE_INITTAG:
1701 asoc->peer.i.init_tag = cmd->obj.u32;
1702 break;
1703 case SCTP_CMD_SEND_MSG:
1704 if (!asoc->outqueue.cork) {
1705 sctp_outq_cork(&asoc->outqueue);
1706 local_cork = 1;
1707 }
1708 error = sctp_cmd_send_msg(asoc, cmd->obj.msg, gfp);
1709 break;
1710 case SCTP_CMD_SEND_NEXT_ASCONF:
1711 sctp_cmd_send_asconf(asoc);
1712 break;
1713 case SCTP_CMD_PURGE_ASCONF_QUEUE:
1714 sctp_asconf_queue_teardown(asoc);
1715 break;
1716
1717 case SCTP_CMD_SET_ASOC:
1718 asoc = cmd->obj.asoc;
1719 break;
1720
1721 default:
1722 pr_warn("Impossible command: %u\n",
1723 cmd->verb);
1724 break;
1725 }
1726
1727 if (error)
1728 break;
1729 }
1730
1731out:
1732 /* If this is in response to a received chunk, wait until
1733 * we are done with the packet to open the queue so that we don't
1734 * send multiple packets in response to a single request.
1735 */
1736 if (asoc && SCTP_EVENT_T_CHUNK == event_type && chunk) {
1737 if (chunk->end_of_packet || chunk->singleton)
1738 error = sctp_outq_uncork(&asoc->outqueue, gfp);
1739 } else if (local_cork)
1740 error = sctp_outq_uncork(&asoc->outqueue, gfp);
1741 return error;
1742nomem:
1743 error = -ENOMEM;
1744 goto out;
1745}
1746
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}