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