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ipc,shm: shorten critical region in shmctl_down
[linux-2.6.git] / net / sctp / sm_sideeffect.c
blob666c668427996903b9baf185a831c1c10c75d8cb
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 <linux-sctp@vger.kernel.org>
32 *
33 * Written or modified by:
34 * La Monte H.P. Yarroll <piggy@acm.org>
35 * Karl Knutson <karl@athena.chicago.il.us>
36 * Jon Grimm <jgrimm@austin.ibm.com>
37 * Hui Huang <hui.huang@nokia.com>
38 * Dajiang Zhang <dajiang.zhang@nokia.com>
39 * Daisy Chang <daisyc@us.ibm.com>
40 * Sridhar Samudrala <sri@us.ibm.com>
41 * Ardelle Fan <ardelle.fan@intel.com>
42 */
43
44 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
45
46 #include <linux/skbuff.h>
47 #include <linux/types.h>
48 #include <linux/socket.h>
49 #include <linux/ip.h>
50 #include <linux/gfp.h>
51 #include <net/sock.h>
52 #include <net/sctp/sctp.h>
53 #include <net/sctp/sm.h>
54
55 static int sctp_cmd_interpreter(sctp_event_t event_type,
56 sctp_subtype_t subtype,
57 sctp_state_t state,
58 struct sctp_endpoint *ep,
59 struct sctp_association *asoc,
60 void *event_arg,
61 sctp_disposition_t status,
62 sctp_cmd_seq_t *commands,
63 gfp_t gfp);
64 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
65 sctp_state_t state,
66 struct sctp_endpoint *ep,
67 struct sctp_association *asoc,
68 void *event_arg,
69 sctp_disposition_t status,
70 sctp_cmd_seq_t *commands,
71 gfp_t gfp);
72
73 static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
74 struct sctp_transport *t);
75 /********************************************************************
76 * Helper functions
77 ********************************************************************/
78
79 /* A helper function for delayed processing of INET ECN CE bit. */
80 static void sctp_do_ecn_ce_work(struct sctp_association *asoc,
81 __u32 lowest_tsn)
82 {
83 /* Save the TSN away for comparison when we receive CWR */
84
85 asoc->last_ecne_tsn = lowest_tsn;
86 asoc->need_ecne = 1;
87 }
88
89 /* Helper function for delayed processing of SCTP ECNE chunk. */
90 /* RFC 2960 Appendix A
91 *
92 * RFC 2481 details a specific bit for a sender to send in
93 * the header of its next outbound TCP segment to indicate to
94 * its peer that it has reduced its congestion window. This
95 * is termed the CWR bit. For SCTP the same indication is made
96 * by including the CWR chunk. This chunk contains one data
97 * element, i.e. the TSN number that was sent in the ECNE chunk.
98 * This element represents the lowest TSN number in the datagram
99 * that was originally marked with the CE bit.
100 */
101 static struct sctp_chunk *sctp_do_ecn_ecne_work(struct sctp_association *asoc,
102 __u32 lowest_tsn,
103 struct sctp_chunk *chunk)
104 {
105 struct sctp_chunk *repl;
106
107 /* Our previously transmitted packet ran into some congestion
108 * so we should take action by reducing cwnd and ssthresh
109 * and then ACK our peer that we we've done so by
110 * sending a CWR.
111 */
112
113 /* First, try to determine if we want to actually lower
114 * our cwnd variables. Only lower them if the ECNE looks more
115 * recent than the last response.
116 */
117 if (TSN_lt(asoc->last_cwr_tsn, lowest_tsn)) {
118 struct sctp_transport *transport;
119
120 /* Find which transport's congestion variables
121 * need to be adjusted.
122 */
123 transport = sctp_assoc_lookup_tsn(asoc, lowest_tsn);
124
125 /* Update the congestion variables. */
126 if (transport)
127 sctp_transport_lower_cwnd(transport,
128 SCTP_LOWER_CWND_ECNE);
129 asoc->last_cwr_tsn = lowest_tsn;
130 }
131
132 /* Always try to quiet the other end. In case of lost CWR,
133 * resend last_cwr_tsn.
134 */
135 repl = sctp_make_cwr(asoc, asoc->last_cwr_tsn, chunk);
136
137 /* If we run out of memory, it will look like a lost CWR. We'll
138 * get back in sync eventually.
139 */
140 return repl;
141 }
142
143 /* Helper function to do delayed processing of ECN CWR chunk. */
144 static void sctp_do_ecn_cwr_work(struct sctp_association *asoc,
145 __u32 lowest_tsn)
146 {
147 /* Turn off ECNE getting auto-prepended to every outgoing
148 * packet
149 */
150 asoc->need_ecne = 0;
151 }
152
153 /* Generate SACK if necessary. We call this at the end of a packet. */
154 static int sctp_gen_sack(struct sctp_association *asoc, int force,
155 sctp_cmd_seq_t *commands)
156 {
157 __u32 ctsn, max_tsn_seen;
158 struct sctp_chunk *sack;
159 struct sctp_transport *trans = asoc->peer.last_data_from;
160 int error = 0;
161
162 if (force ||
163 (!trans && (asoc->param_flags & SPP_SACKDELAY_DISABLE)) ||
164 (trans && (trans->param_flags & SPP_SACKDELAY_DISABLE)))
165 asoc->peer.sack_needed = 1;
166
167 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
168 max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
169
170 /* From 12.2 Parameters necessary per association (i.e. the TCB):
171 *
172 * Ack State : This flag indicates if the next received packet
173 * : is to be responded to with a SACK. ...
174 * : When DATA chunks are out of order, SACK's
175 * : are not delayed (see Section 6).
176 *
177 * [This is actually not mentioned in Section 6, but we
178 * implement it here anyway. --piggy]
179 */
180 if (max_tsn_seen != ctsn)
181 asoc->peer.sack_needed = 1;
182
183 /* From 6.2 Acknowledgement on Reception of DATA Chunks:
184 *
185 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically,
186 * an acknowledgement SHOULD be generated for at least every
187 * second packet (not every second DATA chunk) received, and
188 * SHOULD be generated within 200 ms of the arrival of any
189 * unacknowledged DATA chunk. ...
190 */
191 if (!asoc->peer.sack_needed) {
192 asoc->peer.sack_cnt++;
193
194 /* Set the SACK delay timeout based on the
195 * SACK delay for the last transport
196 * data was received from, or the default
197 * for the association.
198 */
199 if (trans) {
200 /* We will need a SACK for the next packet. */
201 if (asoc->peer.sack_cnt >= trans->sackfreq - 1)
202 asoc->peer.sack_needed = 1;
203
204 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
205 trans->sackdelay;
206 } else {
207 /* We will need a SACK for the next packet. */
208 if (asoc->peer.sack_cnt >= asoc->sackfreq - 1)
209 asoc->peer.sack_needed = 1;
210
211 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
212 asoc->sackdelay;
213 }
214
215 /* Restart the SACK timer. */
216 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
217 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
218 } else {
219 asoc->a_rwnd = asoc->rwnd;
220 sack = sctp_make_sack(asoc);
221 if (!sack)
222 goto nomem;
223
224 asoc->peer.sack_needed = 0;
225 asoc->peer.sack_cnt = 0;
226
227 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(sack));
228
229 /* Stop the SACK timer. */
230 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
231 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
232 }
233
234 return error;
235 nomem:
236 error = -ENOMEM;
237 return error;
238 }
239
240 /* When the T3-RTX timer expires, it calls this function to create the
241 * relevant state machine event.
242 */
243 void sctp_generate_t3_rtx_event(unsigned long peer)
244 {
245 int error;
246 struct sctp_transport *transport = (struct sctp_transport *) peer;
247 struct sctp_association *asoc = transport->asoc;
248 struct net *net = sock_net(asoc->base.sk);
249
250 /* Check whether a task is in the sock. */
251
252 sctp_bh_lock_sock(asoc->base.sk);
253 if (sock_owned_by_user(asoc->base.sk)) {
254 pr_debug("%s: sock is busy\n", __func__);
255
256 /* Try again later. */
257 if (!mod_timer(&transport->T3_rtx_timer, jiffies + (HZ/20)))
258 sctp_transport_hold(transport);
259 goto out_unlock;
260 }
261
262 /* Is this transport really dead and just waiting around for
263 * the timer to let go of the reference?
264 */
265 if (transport->dead)
266 goto out_unlock;
267
268 /* Run through the state machine. */
269 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
270 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX),
271 asoc->state,
272 asoc->ep, asoc,
273 transport, GFP_ATOMIC);
274
275 if (error)
276 asoc->base.sk->sk_err = -error;
277
278 out_unlock:
279 sctp_bh_unlock_sock(asoc->base.sk);
280 sctp_transport_put(transport);
281 }
282
283 /* This is a sa interface for producing timeout events. It works
284 * for timeouts which use the association as their parameter.
285 */
286 static void sctp_generate_timeout_event(struct sctp_association *asoc,
287 sctp_event_timeout_t timeout_type)
288 {
289 struct net *net = sock_net(asoc->base.sk);
290 int error = 0;
291
292 sctp_bh_lock_sock(asoc->base.sk);
293 if (sock_owned_by_user(asoc->base.sk)) {
294 pr_debug("%s: sock is busy: timer %d\n", __func__,
295 timeout_type);
296
297 /* Try again later. */
298 if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20)))
299 sctp_association_hold(asoc);
300 goto out_unlock;
301 }
302
303 /* Is this association really dead and just waiting around for
304 * the timer to let go of the reference?
305 */
306 if (asoc->base.dead)
307 goto out_unlock;
308
309 /* Run through the state machine. */
310 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
311 SCTP_ST_TIMEOUT(timeout_type),
312 asoc->state, asoc->ep, asoc,
313 (void *)timeout_type, GFP_ATOMIC);
314
315 if (error)
316 asoc->base.sk->sk_err = -error;
317
318 out_unlock:
319 sctp_bh_unlock_sock(asoc->base.sk);
320 sctp_association_put(asoc);
321 }
322
323 static void sctp_generate_t1_cookie_event(unsigned long data)
324 {
325 struct sctp_association *asoc = (struct sctp_association *) data;
326 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
327 }
328
329 static void sctp_generate_t1_init_event(unsigned long data)
330 {
331 struct sctp_association *asoc = (struct sctp_association *) data;
332 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
333 }
334
335 static void sctp_generate_t2_shutdown_event(unsigned long data)
336 {
337 struct sctp_association *asoc = (struct sctp_association *) data;
338 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
339 }
340
341 static void sctp_generate_t4_rto_event(unsigned long data)
342 {
343 struct sctp_association *asoc = (struct sctp_association *) data;
344 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
345 }
346
347 static void sctp_generate_t5_shutdown_guard_event(unsigned long data)
348 {
349 struct sctp_association *asoc = (struct sctp_association *)data;
350 sctp_generate_timeout_event(asoc,
351 SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);
352
353 } /* sctp_generate_t5_shutdown_guard_event() */
354
355 static void sctp_generate_autoclose_event(unsigned long data)
356 {
357 struct sctp_association *asoc = (struct sctp_association *) data;
358 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE);
359 }
360
361 /* Generate a heart beat event. If the sock is busy, reschedule. Make
362 * sure that the transport is still valid.
363 */
364 void sctp_generate_heartbeat_event(unsigned long data)
365 {
366 int error = 0;
367 struct sctp_transport *transport = (struct sctp_transport *) data;
368 struct sctp_association *asoc = transport->asoc;
369 struct net *net = sock_net(asoc->base.sk);
370
371 sctp_bh_lock_sock(asoc->base.sk);
372 if (sock_owned_by_user(asoc->base.sk)) {
373 pr_debug("%s: sock is busy\n", __func__);
374
375 /* Try again later. */
376 if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20)))
377 sctp_transport_hold(transport);
378 goto out_unlock;
379 }
380
381 /* Is this structure just waiting around for us to actually
382 * get destroyed?
383 */
384 if (transport->dead)
385 goto out_unlock;
386
387 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
388 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
389 asoc->state, asoc->ep, asoc,
390 transport, GFP_ATOMIC);
391
392 if (error)
393 asoc->base.sk->sk_err = -error;
394
395 out_unlock:
396 sctp_bh_unlock_sock(asoc->base.sk);
397 sctp_transport_put(transport);
398 }
399
400 /* Handle the timeout of the ICMP protocol unreachable timer. Trigger
401 * the correct state machine transition that will close the association.
402 */
403 void sctp_generate_proto_unreach_event(unsigned long data)
404 {
405 struct sctp_transport *transport = (struct sctp_transport *) data;
406 struct sctp_association *asoc = transport->asoc;
407 struct net *net = sock_net(asoc->base.sk);
408
409 sctp_bh_lock_sock(asoc->base.sk);
410 if (sock_owned_by_user(asoc->base.sk)) {
411 pr_debug("%s: sock is busy\n", __func__);
412
413 /* Try again later. */
414 if (!mod_timer(&transport->proto_unreach_timer,
415 jiffies + (HZ/20)))
416 sctp_association_hold(asoc);
417 goto out_unlock;
418 }
419
420 /* Is this structure just waiting around for us to actually
421 * get destroyed?
422 */
423 if (asoc->base.dead)
424 goto out_unlock;
425
426 sctp_do_sm(net, SCTP_EVENT_T_OTHER,
427 SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH),
428 asoc->state, asoc->ep, asoc, transport, GFP_ATOMIC);
429
430 out_unlock:
431 sctp_bh_unlock_sock(asoc->base.sk);
432 sctp_association_put(asoc);
433 }
434
435
436 /* Inject a SACK Timeout event into the state machine. */
437 static void sctp_generate_sack_event(unsigned long data)
438 {
439 struct sctp_association *asoc = (struct sctp_association *) data;
440 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
441 }
442
443 sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
444 NULL,
445 sctp_generate_t1_cookie_event,
446 sctp_generate_t1_init_event,
447 sctp_generate_t2_shutdown_event,
448 NULL,
449 sctp_generate_t4_rto_event,
450 sctp_generate_t5_shutdown_guard_event,
451 NULL,
452 sctp_generate_sack_event,
453 sctp_generate_autoclose_event,
454 };
455
456
457 /* RFC 2960 8.2 Path Failure Detection
458 *
459 * When its peer endpoint is multi-homed, an endpoint should keep a
460 * error counter for each of the destination transport addresses of the
461 * peer endpoint.
462 *
463 * Each time the T3-rtx timer expires on any address, or when a
464 * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
465 * the error counter of that destination address will be incremented.
466 * When the value in the error counter exceeds the protocol parameter
467 * 'Path.Max.Retrans' of that destination address, the endpoint should
468 * mark the destination transport address as inactive, and a
469 * notification SHOULD be sent to the upper layer.
470 *
471 */
472 static void sctp_do_8_2_transport_strike(sctp_cmd_seq_t *commands,
473 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 the transport error count is greater than the pf_retrans
499 * threshold, and less than pathmaxrtx, then mark this transport
500 * as Partially Failed, ee SCTP Quick Failover Draft, secon 5.1,
501 * point 1
502 */
503 if ((transport->state != SCTP_PF) &&
504 (asoc->pf_retrans < transport->pathmaxrxt) &&
505 (transport->error_count > asoc->pf_retrans)) {
506
507 sctp_assoc_control_transport(asoc, transport,
508 SCTP_TRANSPORT_PF,
509 0);
510
511 /* Update the hb timer to resend a heartbeat every rto */
512 sctp_cmd_hb_timer_update(commands, transport);
513 }
514
515 if (transport->state != SCTP_INACTIVE &&
516 (transport->error_count > transport->pathmaxrxt)) {
517 pr_debug("%s: association:%p transport addr:%pISpc failed\n",
518 __func__, asoc, &transport->ipaddr.sa);
519
520 sctp_assoc_control_transport(asoc, transport,
521 SCTP_TRANSPORT_DOWN,
522 SCTP_FAILED_THRESHOLD);
523 }
524
525 /* E2) For the destination address for which the timer
526 * expires, set RTO <- RTO * 2 ("back off the timer"). The
527 * maximum value discussed in rule C7 above (RTO.max) may be
528 * used to provide an upper bound to this doubling operation.
529 *
530 * Special Case: the first HB doesn't trigger exponential backoff.
531 * The first unacknowledged HB triggers it. We do this with a flag
532 * that indicates that we have an outstanding HB.
533 */
534 if (!is_hb || transport->hb_sent) {
535 transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
536 sctp_max_rto(asoc, transport);
537 }
538 }
539
540 /* Worker routine to handle INIT command failure. */
541 static void sctp_cmd_init_failed(sctp_cmd_seq_t *commands,
542 struct sctp_association *asoc,
543 unsigned int error)
544 {
545 struct sctp_ulpevent *event;
546
547 event = sctp_ulpevent_make_assoc_change(asoc,0, SCTP_CANT_STR_ASSOC,
548 (__u16)error, 0, 0, NULL,
549 GFP_ATOMIC);
550
551 if (event)
552 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
553 SCTP_ULPEVENT(event));
554
555 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
556 SCTP_STATE(SCTP_STATE_CLOSED));
557
558 /* SEND_FAILED sent later when cleaning up the association. */
559 asoc->outqueue.error = error;
560 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
561 }
562
563 /* Worker routine to handle SCTP_CMD_ASSOC_FAILED. */
564 static void sctp_cmd_assoc_failed(sctp_cmd_seq_t *commands,
565 struct sctp_association *asoc,
566 sctp_event_t event_type,
567 sctp_subtype_t subtype,
568 struct sctp_chunk *chunk,
569 unsigned int error)
570 {
571 struct sctp_ulpevent *event;
572 struct sctp_chunk *abort;
573 /* Cancel any partial delivery in progress. */
574 sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
575
576 if (event_type == SCTP_EVENT_T_CHUNK && subtype.chunk == SCTP_CID_ABORT)
577 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
578 (__u16)error, 0, 0, chunk,
579 GFP_ATOMIC);
580 else
581 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
582 (__u16)error, 0, 0, NULL,
583 GFP_ATOMIC);
584 if (event)
585 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
586 SCTP_ULPEVENT(event));
587
588 if (asoc->overall_error_count >= asoc->max_retrans) {
589 abort = sctp_make_violation_max_retrans(asoc, chunk);
590 if (abort)
591 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
592 SCTP_CHUNK(abort));
593 }
594
595 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
596 SCTP_STATE(SCTP_STATE_CLOSED));
597
598 /* SEND_FAILED sent later when cleaning up the association. */
599 asoc->outqueue.error = error;
600 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
601 }
602
603 /* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
604 * inside the cookie. In reality, this is only used for INIT-ACK processing
605 * since all other cases use "temporary" associations and can do all
606 * their work in statefuns directly.
607 */
608 static int sctp_cmd_process_init(sctp_cmd_seq_t *commands,
609 struct sctp_association *asoc,
610 struct sctp_chunk *chunk,
611 sctp_init_chunk_t *peer_init,
612 gfp_t gfp)
613 {
614 int error;
615
616 /* We only process the init as a sideeffect in a single
617 * case. This is when we process the INIT-ACK. If we
618 * fail during INIT processing (due to malloc problems),
619 * just return the error and stop processing the stack.
620 */
621 if (!sctp_process_init(asoc, chunk, sctp_source(chunk), peer_init, gfp))
622 error = -ENOMEM;
623 else
624 error = 0;
625
626 return error;
627 }
628
629 /* Helper function to break out starting up of heartbeat timers. */
630 static void sctp_cmd_hb_timers_start(sctp_cmd_seq_t *cmds,
631 struct sctp_association *asoc)
632 {
633 struct sctp_transport *t;
634
635 /* Start a heartbeat timer for each transport on the association.
636 * hold a reference on the transport to make sure none of
637 * the needed data structures go away.
638 */
639 list_for_each_entry(t, &asoc->peer.transport_addr_list, transports) {
640
641 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
642 sctp_transport_hold(t);
643 }
644 }
645
646 static void sctp_cmd_hb_timers_stop(sctp_cmd_seq_t *cmds,
647 struct sctp_association *asoc)
648 {
649 struct sctp_transport *t;
650
651 /* Stop all heartbeat timers. */
652
653 list_for_each_entry(t, &asoc->peer.transport_addr_list,
654 transports) {
655 if (del_timer(&t->hb_timer))
656 sctp_transport_put(t);
657 }
658 }
659
660 /* Helper function to stop any pending T3-RTX timers */
661 static void sctp_cmd_t3_rtx_timers_stop(sctp_cmd_seq_t *cmds,
662 struct sctp_association *asoc)
663 {
664 struct sctp_transport *t;
665
666 list_for_each_entry(t, &asoc->peer.transport_addr_list,
667 transports) {
668 if (del_timer(&t->T3_rtx_timer))
669 sctp_transport_put(t);
670 }
671 }
672
673
674 /* Helper function to update the heartbeat timer. */
675 static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
676 struct sctp_transport *t)
677 {
678 /* Update the heartbeat timer. */
679 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
680 sctp_transport_hold(t);
681 }
682
683 /* Helper function to handle the reception of an HEARTBEAT ACK. */
684 static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds,
685 struct sctp_association *asoc,
686 struct sctp_transport *t,
687 struct sctp_chunk *chunk)
688 {
689 sctp_sender_hb_info_t *hbinfo;
690 int was_unconfirmed = 0;
691
692 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
693 * HEARTBEAT should clear the error counter of the destination
694 * transport address to which the HEARTBEAT was sent.
695 */
696 t->error_count = 0;
697
698 /*
699 * Although RFC4960 specifies that the overall error count must
700 * be cleared when a HEARTBEAT ACK is received, we make an
701 * exception while in SHUTDOWN PENDING. If the peer keeps its
702 * window shut forever, we may never be able to transmit our
703 * outstanding data and rely on the retransmission limit be reached
704 * to shutdown the association.
705 */
706 if (t->asoc->state != SCTP_STATE_SHUTDOWN_PENDING)
707 t->asoc->overall_error_count = 0;
708
709 /* Clear the hb_sent flag to signal that we had a good
710 * acknowledgement.
711 */
712 t->hb_sent = 0;
713
714 /* Mark the destination transport address as active if it is not so
715 * marked.
716 */
717 if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED)) {
718 was_unconfirmed = 1;
719 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
720 SCTP_HEARTBEAT_SUCCESS);
721 }
722
723 if (t->state == SCTP_PF)
724 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
725 SCTP_HEARTBEAT_SUCCESS);
726
727 /* HB-ACK was received for a the proper HB. Consider this
728 * forward progress.
729 */
730 if (t->dst)
731 dst_confirm(t->dst);
732
733 /* The receiver of the HEARTBEAT ACK should also perform an
734 * RTT measurement for that destination transport address
735 * using the time value carried in the HEARTBEAT ACK chunk.
736 * If the transport's rto_pending variable has been cleared,
737 * it was most likely due to a retransmit. However, we want
738 * to re-enable it to properly update the rto.
739 */
740 if (t->rto_pending == 0)
741 t->rto_pending = 1;
742
743 hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
744 sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
745
746 /* Update the heartbeat timer. */
747 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
748 sctp_transport_hold(t);
749
750 if (was_unconfirmed && asoc->peer.transport_count == 1)
751 sctp_transport_immediate_rtx(t);
752 }
753
754
755 /* Helper function to process the process SACK command. */
756 static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds,
757 struct sctp_association *asoc,
758 struct sctp_chunk *chunk)
759 {
760 int err = 0;
761
762 if (sctp_outq_sack(&asoc->outqueue, chunk)) {
763 struct net *net = sock_net(asoc->base.sk);
764
765 /* There are no more TSNs awaiting SACK. */
766 err = sctp_do_sm(net, SCTP_EVENT_T_OTHER,
767 SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
768 asoc->state, asoc->ep, asoc, NULL,
769 GFP_ATOMIC);
770 }
771
772 return err;
773 }
774
775 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
776 * the transport for a shutdown chunk.
777 */
778 static void sctp_cmd_setup_t2(sctp_cmd_seq_t *cmds,
779 struct sctp_association *asoc,
780 struct sctp_chunk *chunk)
781 {
782 struct sctp_transport *t;
783
784 if (chunk->transport)
785 t = chunk->transport;
786 else {
787 t = sctp_assoc_choose_alter_transport(asoc,
788 asoc->shutdown_last_sent_to);
789 chunk->transport = t;
790 }
791 asoc->shutdown_last_sent_to = t;
792 asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
793 }
794
795 /* Helper function to change the state of an association. */
796 static void sctp_cmd_new_state(sctp_cmd_seq_t *cmds,
797 struct sctp_association *asoc,
798 sctp_state_t state)
799 {
800 struct sock *sk = asoc->base.sk;
801
802 asoc->state = state;
803
804 pr_debug("%s: asoc:%p[%s]\n", __func__, asoc, sctp_state_tbl[state]);
805
806 if (sctp_style(sk, TCP)) {
807 /* Change the sk->sk_state of a TCP-style socket that has
808 * successfully completed a connect() call.
809 */
810 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
811 sk->sk_state = SCTP_SS_ESTABLISHED;
812
813 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
814 if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
815 sctp_sstate(sk, ESTABLISHED))
816 sk->sk_shutdown |= RCV_SHUTDOWN;
817 }
818
819 if (sctp_state(asoc, COOKIE_WAIT)) {
820 /* Reset init timeouts since they may have been
821 * increased due to timer expirations.
822 */
823 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
824 asoc->rto_initial;
825 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
826 asoc->rto_initial;
827 }
828
829 if (sctp_state(asoc, ESTABLISHED) ||
830 sctp_state(asoc, CLOSED) ||
831 sctp_state(asoc, SHUTDOWN_RECEIVED)) {
832 /* Wake up any processes waiting in the asoc's wait queue in
833 * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
834 */
835 if (waitqueue_active(&asoc->wait))
836 wake_up_interruptible(&asoc->wait);
837
838 /* Wake up any processes waiting in the sk's sleep queue of
839 * a TCP-style or UDP-style peeled-off socket in
840 * sctp_wait_for_accept() or sctp_wait_for_packet().
841 * For a UDP-style socket, the waiters are woken up by the
842 * notifications.
843 */
844 if (!sctp_style(sk, UDP))
845 sk->sk_state_change(sk);
846 }
847 }
848
849 /* Helper function to delete an association. */
850 static void sctp_cmd_delete_tcb(sctp_cmd_seq_t *cmds,
851 struct sctp_association *asoc)
852 {
853 struct sock *sk = asoc->base.sk;
854
855 /* If it is a non-temporary association belonging to a TCP-style
856 * listening socket that is not closed, do not free it so that accept()
857 * can pick it up later.
858 */
859 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
860 (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
861 return;
862
863 BUG_ON(asoc->peer.primary_path == NULL);
864 sctp_unhash_established(asoc);
865 sctp_association_free(asoc);
866 }
867
868 /*
869 * ADDIP Section 4.1 ASCONF Chunk Procedures
870 * A4) Start a T-4 RTO timer, using the RTO value of the selected
871 * destination address (we use active path instead of primary path just
872 * because primary path may be inactive.
873 */
874 static void sctp_cmd_setup_t4(sctp_cmd_seq_t *cmds,
875 struct sctp_association *asoc,
876 struct sctp_chunk *chunk)
877 {
878 struct sctp_transport *t;
879
880 t = sctp_assoc_choose_alter_transport(asoc, chunk->transport);
881 asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
882 chunk->transport = t;
883 }
884
885 /* Process an incoming Operation Error Chunk. */
886 static void sctp_cmd_process_operr(sctp_cmd_seq_t *cmds,
887 struct sctp_association *asoc,
888 struct sctp_chunk *chunk)
889 {
890 struct sctp_errhdr *err_hdr;
891 struct sctp_ulpevent *ev;
892
893 while (chunk->chunk_end > chunk->skb->data) {
894 err_hdr = (struct sctp_errhdr *)(chunk->skb->data);
895
896 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
897 GFP_ATOMIC);
898 if (!ev)
899 return;
900
901 sctp_ulpq_tail_event(&asoc->ulpq, ev);
902
903 switch (err_hdr->cause) {
904 case SCTP_ERROR_UNKNOWN_CHUNK:
905 {
906 sctp_chunkhdr_t *unk_chunk_hdr;
907
908 unk_chunk_hdr = (sctp_chunkhdr_t *)err_hdr->variable;
909 switch (unk_chunk_hdr->type) {
910 /* ADDIP 4.1 A9) If the peer responds to an ASCONF with
911 * an ERROR chunk reporting that it did not recognized
912 * the ASCONF chunk type, the sender of the ASCONF MUST
913 * NOT send any further ASCONF chunks and MUST stop its
914 * T-4 timer.
915 */
916 case SCTP_CID_ASCONF:
917 if (asoc->peer.asconf_capable == 0)
918 break;
919
920 asoc->peer.asconf_capable = 0;
921 sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
922 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
923 break;
924 default:
925 break;
926 }
927 break;
928 }
929 default:
930 break;
931 }
932 }
933 }
934
935 /* Process variable FWDTSN chunk information. */
936 static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq,
937 struct sctp_chunk *chunk)
938 {
939 struct sctp_fwdtsn_skip *skip;
940 /* Walk through all the skipped SSNs */
941 sctp_walk_fwdtsn(skip, chunk) {
942 sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
943 }
944 }
945
946 /* Helper function to remove the association non-primary peer
947 * transports.
948 */
949 static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
950 {
951 struct sctp_transport *t;
952 struct list_head *pos;
953 struct list_head *temp;
954
955 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
956 t = list_entry(pos, struct sctp_transport, transports);
957 if (!sctp_cmp_addr_exact(&t->ipaddr,
958 &asoc->peer.primary_addr)) {
959 sctp_assoc_del_peer(asoc, &t->ipaddr);
960 }
961 }
962 }
963
964 /* Helper function to set sk_err on a 1-1 style socket. */
965 static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
966 {
967 struct sock *sk = asoc->base.sk;
968
969 if (!sctp_style(sk, UDP))
970 sk->sk_err = error;
971 }
972
973 /* Helper function to generate an association change event */
974 static void sctp_cmd_assoc_change(sctp_cmd_seq_t *commands,
975 struct sctp_association *asoc,
976 u8 state)
977 {
978 struct sctp_ulpevent *ev;
979
980 ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0,
981 asoc->c.sinit_num_ostreams,
982 asoc->c.sinit_max_instreams,
983 NULL, GFP_ATOMIC);
984 if (ev)
985 sctp_ulpq_tail_event(&asoc->ulpq, ev);
986 }
987
988 /* Helper function to generate an adaptation indication event */
989 static void sctp_cmd_adaptation_ind(sctp_cmd_seq_t *commands,
990 struct sctp_association *asoc)
991 {
992 struct sctp_ulpevent *ev;
993
994 ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
995
996 if (ev)
997 sctp_ulpq_tail_event(&asoc->ulpq, ev);
998 }
999
1000
1001 static void sctp_cmd_t1_timer_update(struct sctp_association *asoc,
1002 sctp_event_timeout_t timer,
1003 char *name)
1004 {
1005 struct sctp_transport *t;
1006
1007 t = asoc->init_last_sent_to;
1008 asoc->init_err_counter++;
1009
1010 if (t->init_sent_count > (asoc->init_cycle + 1)) {
1011 asoc->timeouts[timer] *= 2;
1012 if (asoc->timeouts[timer] > asoc->max_init_timeo) {
1013 asoc->timeouts[timer] = asoc->max_init_timeo;
1014 }
1015 asoc->init_cycle++;
1016
1017 pr_debug("%s: T1[%s] timeout adjustment init_err_counter:%d"
1018 " cycle:%d timeout:%ld\n", __func__, name,
1019 asoc->init_err_counter, asoc->init_cycle,
1020 asoc->timeouts[timer]);
1021 }
1022
1023 }
1024
1025 /* Send the whole message, chunk by chunk, to the outqueue.
1026 * This way the whole message is queued up and bundling if
1027 * encouraged for small fragments.
1028 */
1029 static int sctp_cmd_send_msg(struct sctp_association *asoc,
1030 struct sctp_datamsg *msg)
1031 {
1032 struct sctp_chunk *chunk;
1033 int error = 0;
1034
1035 list_for_each_entry(chunk, &msg->chunks, frag_list) {
1036 error = sctp_outq_tail(&asoc->outqueue, chunk);
1037 if (error)
1038 break;
1039 }
1040
1041 return error;
1042 }
1043
1044
1045 /* Sent the next ASCONF packet currently stored in the association.
1046 * This happens after the ASCONF_ACK was succeffully processed.
1047 */
1048 static void sctp_cmd_send_asconf(struct sctp_association *asoc)
1049 {
1050 struct net *net = sock_net(asoc->base.sk);
1051
1052 /* Send the next asconf chunk from the addip chunk
1053 * queue.
1054 */
1055 if (!list_empty(&asoc->addip_chunk_list)) {
1056 struct list_head *entry = asoc->addip_chunk_list.next;
1057 struct sctp_chunk *asconf = list_entry(entry,
1058 struct sctp_chunk, list);
1059 list_del_init(entry);
1060
1061 /* Hold the chunk until an ASCONF_ACK is received. */
1062 sctp_chunk_hold(asconf);
1063 if (sctp_primitive_ASCONF(net, asoc, asconf))
1064 sctp_chunk_free(asconf);
1065 else
1066 asoc->addip_last_asconf = asconf;
1067 }
1068 }
1069
1070
1071 /* These three macros allow us to pull the debugging code out of the
1072 * main flow of sctp_do_sm() to keep attention focused on the real
1073 * functionality there.
1074 */
1075 #define debug_pre_sfn() \
1076 pr_debug("%s[pre-fn]: ep:%p, %s, %s, asoc:%p[%s], %s\n", __func__, \
1077 ep, sctp_evttype_tbl[event_type], (*debug_fn)(subtype), \
1078 asoc, sctp_state_tbl[state], state_fn->name)
1079
1080 #define debug_post_sfn() \
1081 pr_debug("%s[post-fn]: asoc:%p, status:%s\n", __func__, asoc, \
1082 sctp_status_tbl[status])
1083
1084 #define debug_post_sfx() \
1085 pr_debug("%s[post-sfx]: error:%d, asoc:%p[%s]\n", __func__, error, \
1086 asoc, sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
1087 sctp_assoc2id(asoc))) ? asoc->state : SCTP_STATE_CLOSED])
1088
1089 /*
1090 * This is the master state machine processing function.
1091 *
1092 * If you want to understand all of lksctp, this is a
1093 * good place to start.
1094 */
1095 int sctp_do_sm(struct net *net, sctp_event_t event_type, sctp_subtype_t subtype,
1096 sctp_state_t state,
1097 struct sctp_endpoint *ep,
1098 struct sctp_association *asoc,
1099 void *event_arg,
1100 gfp_t gfp)
1101 {
1102 sctp_cmd_seq_t commands;
1103 const sctp_sm_table_entry_t *state_fn;
1104 sctp_disposition_t status;
1105 int error = 0;
1106 typedef const char *(printfn_t)(sctp_subtype_t);
1107 static printfn_t *table[] = {
1108 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
1109 };
1110 printfn_t *debug_fn __attribute__ ((unused)) = table[event_type];
1111
1112 /* Look up the state function, run it, and then process the
1113 * side effects. These three steps are the heart of lksctp.
1114 */
1115 state_fn = sctp_sm_lookup_event(net, event_type, state, subtype);
1116
1117 sctp_init_cmd_seq(&commands);
1118
1119 debug_pre_sfn();
1120 status = (*state_fn->fn)(net, ep, asoc, subtype, event_arg, &commands);
1121 debug_post_sfn();
1122
1123 error = sctp_side_effects(event_type, subtype, state,
1124 ep, asoc, event_arg, status,
1125 &commands, gfp);
1126 debug_post_sfx();
1127
1128 return error;
1129 }
1130
1131 /*****************************************************************
1132 * This the master state function side effect processing function.
1133 *****************************************************************/
1134 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
1135 sctp_state_t state,
1136 struct sctp_endpoint *ep,
1137 struct sctp_association *asoc,
1138 void *event_arg,
1139 sctp_disposition_t status,
1140 sctp_cmd_seq_t *commands,
1141 gfp_t gfp)
1142 {
1143 int error;
1144
1145 /* FIXME - Most of the dispositions left today would be categorized
1146 * as "exceptional" dispositions. For those dispositions, it
1147 * may not be proper to run through any of the commands at all.
1148 * For example, the command interpreter might be run only with
1149 * disposition SCTP_DISPOSITION_CONSUME.
1150 */
1151 if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
1152 ep, asoc,
1153 event_arg, status,
1154 commands, gfp)))
1155 goto bail;
1156
1157 switch (status) {
1158 case SCTP_DISPOSITION_DISCARD:
1159 pr_debug("%s: ignored sctp protocol event - state:%d, "
1160 "event_type:%d, event_id:%d\n", __func__, state,
1161 event_type, subtype.chunk);
1162 break;
1163
1164 case SCTP_DISPOSITION_NOMEM:
1165 /* We ran out of memory, so we need to discard this
1166 * packet.
1167 */
1168 /* BUG--we should now recover some memory, probably by
1169 * reneging...
1170 */
1171 error = -ENOMEM;
1172 break;
1173
1174 case SCTP_DISPOSITION_DELETE_TCB:
1175 /* This should now be a command. */
1176 break;
1177
1178 case SCTP_DISPOSITION_CONSUME:
1179 case SCTP_DISPOSITION_ABORT:
1180 /*
1181 * We should no longer have much work to do here as the
1182 * real work has been done as explicit commands above.
1183 */
1184 break;
1185
1186 case SCTP_DISPOSITION_VIOLATION:
1187 net_err_ratelimited("protocol violation state %d chunkid %d\n",
1188 state, subtype.chunk);
1189 break;
1190
1191 case SCTP_DISPOSITION_NOT_IMPL:
1192 pr_warn("unimplemented feature in state %d, event_type %d, event_id %d\n",
1193 state, event_type, subtype.chunk);
1194 break;
1195
1196 case SCTP_DISPOSITION_BUG:
1197 pr_err("bug in state %d, event_type %d, event_id %d\n",
1198 state, event_type, subtype.chunk);
1199 BUG();
1200 break;
1201
1202 default:
1203 pr_err("impossible disposition %d in state %d, event_type %d, event_id %d\n",
1204 status, state, event_type, subtype.chunk);
1205 BUG();
1206 break;
1207 }
1208
1209 bail:
1210 return error;
1211 }
1212
1213 /********************************************************************
1214 * 2nd Level Abstractions
1215 ********************************************************************/
1216
1217 /* This is the side-effect interpreter. */
1218 static int sctp_cmd_interpreter(sctp_event_t event_type,
1219 sctp_subtype_t subtype,
1220 sctp_state_t state,
1221 struct sctp_endpoint *ep,
1222 struct sctp_association *asoc,
1223 void *event_arg,
1224 sctp_disposition_t status,
1225 sctp_cmd_seq_t *commands,
1226 gfp_t gfp)
1227 {
1228 int error = 0;
1229 int force;
1230 sctp_cmd_t *cmd;
1231 struct sctp_chunk *new_obj;
1232 struct sctp_chunk *chunk = NULL;
1233 struct sctp_packet *packet;
1234 struct timer_list *timer;
1235 unsigned long timeout;
1236 struct sctp_transport *t;
1237 struct sctp_sackhdr sackh;
1238 int local_cork = 0;
1239
1240 if (SCTP_EVENT_T_TIMEOUT != event_type)
1241 chunk = event_arg;
1242
1243 /* Note: This whole file is a huge candidate for rework.
1244 * For example, each command could either have its own handler, so
1245 * the loop would look like:
1246 * while (cmds)
1247 * cmd->handle(x, y, z)
1248 * --jgrimm
1249 */
1250 while (NULL != (cmd = sctp_next_cmd(commands))) {
1251 switch (cmd->verb) {
1252 case SCTP_CMD_NOP:
1253 /* Do nothing. */
1254 break;
1255
1256 case SCTP_CMD_NEW_ASOC:
1257 /* Register a new association. */
1258 if (local_cork) {
1259 sctp_outq_uncork(&asoc->outqueue);
1260 local_cork = 0;
1261 }
1262
1263 /* Register with the endpoint. */
1264 asoc = cmd->obj.asoc;
1265 BUG_ON(asoc->peer.primary_path == NULL);
1266 sctp_endpoint_add_asoc(ep, asoc);
1267 sctp_hash_established(asoc);
1268 break;
1269
1270 case SCTP_CMD_UPDATE_ASSOC:
1271 sctp_assoc_update(asoc, cmd->obj.asoc);
1272 break;
1273
1274 case SCTP_CMD_PURGE_OUTQUEUE:
1275 sctp_outq_teardown(&asoc->outqueue);
1276 break;
1277
1278 case SCTP_CMD_DELETE_TCB:
1279 if (local_cork) {
1280 sctp_outq_uncork(&asoc->outqueue);
1281 local_cork = 0;
1282 }
1283 /* Delete the current association. */
1284 sctp_cmd_delete_tcb(commands, asoc);
1285 asoc = NULL;
1286 break;
1287
1288 case SCTP_CMD_NEW_STATE:
1289 /* Enter a new state. */
1290 sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1291 break;
1292
1293 case SCTP_CMD_REPORT_TSN:
1294 /* Record the arrival of a TSN. */
1295 error = sctp_tsnmap_mark(&asoc->peer.tsn_map,
1296 cmd->obj.u32, NULL);
1297 break;
1298
1299 case SCTP_CMD_REPORT_FWDTSN:
1300 /* Move the Cumulattive TSN Ack ahead. */
1301 sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32);
1302
1303 /* purge the fragmentation queue */
1304 sctp_ulpq_reasm_flushtsn(&asoc->ulpq, cmd->obj.u32);
1305
1306 /* Abort any in progress partial delivery. */
1307 sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
1308 break;
1309
1310 case SCTP_CMD_PROCESS_FWDTSN:
1311 sctp_cmd_process_fwdtsn(&asoc->ulpq, cmd->obj.chunk);
1312 break;
1313
1314 case SCTP_CMD_GEN_SACK:
1315 /* Generate a Selective ACK.
1316 * The argument tells us whether to just count
1317 * the packet and MAYBE generate a SACK, or
1318 * force a SACK out.
1319 */
1320 force = cmd->obj.i32;
1321 error = sctp_gen_sack(asoc, force, commands);
1322 break;
1323
1324 case SCTP_CMD_PROCESS_SACK:
1325 /* Process an inbound SACK. */
1326 error = sctp_cmd_process_sack(commands, asoc,
1327 cmd->obj.chunk);
1328 break;
1329
1330 case SCTP_CMD_GEN_INIT_ACK:
1331 /* Generate an INIT ACK chunk. */
1332 new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1333 0);
1334 if (!new_obj)
1335 goto nomem;
1336
1337 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1338 SCTP_CHUNK(new_obj));
1339 break;
1340
1341 case SCTP_CMD_PEER_INIT:
1342 /* Process a unified INIT from the peer.
1343 * Note: Only used during INIT-ACK processing. If
1344 * there is an error just return to the outter
1345 * layer which will bail.
1346 */
1347 error = sctp_cmd_process_init(commands, asoc, chunk,
1348 cmd->obj.init, gfp);
1349 break;
1350
1351 case SCTP_CMD_GEN_COOKIE_ECHO:
1352 /* Generate a COOKIE ECHO chunk. */
1353 new_obj = sctp_make_cookie_echo(asoc, chunk);
1354 if (!new_obj) {
1355 if (cmd->obj.chunk)
1356 sctp_chunk_free(cmd->obj.chunk);
1357 goto nomem;
1358 }
1359 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1360 SCTP_CHUNK(new_obj));
1361
1362 /* If there is an ERROR chunk to be sent along with
1363 * the COOKIE_ECHO, send it, too.
1364 */
1365 if (cmd->obj.chunk)
1366 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1367 SCTP_CHUNK(cmd->obj.chunk));
1368
1369 if (new_obj->transport) {
1370 new_obj->transport->init_sent_count++;
1371 asoc->init_last_sent_to = new_obj->transport;
1372 }
1373
1374 /* FIXME - Eventually come up with a cleaner way to
1375 * enabling COOKIE-ECHO + DATA bundling during
1376 * multihoming stale cookie scenarios, the following
1377 * command plays with asoc->peer.retran_path to
1378 * avoid the problem of sending the COOKIE-ECHO and
1379 * DATA in different paths, which could result
1380 * in the association being ABORTed if the DATA chunk
1381 * is processed first by the server. Checking the
1382 * init error counter simply causes this command
1383 * to be executed only during failed attempts of
1384 * association establishment.
1385 */
1386 if ((asoc->peer.retran_path !=
1387 asoc->peer.primary_path) &&
1388 (asoc->init_err_counter > 0)) {
1389 sctp_add_cmd_sf(commands,
1390 SCTP_CMD_FORCE_PRIM_RETRAN,
1391 SCTP_NULL());
1392 }
1393
1394 break;
1395
1396 case SCTP_CMD_GEN_SHUTDOWN:
1397 /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1398 * Reset error counts.
1399 */
1400 asoc->overall_error_count = 0;
1401
1402 /* Generate a SHUTDOWN chunk. */
1403 new_obj = sctp_make_shutdown(asoc, chunk);
1404 if (!new_obj)
1405 goto nomem;
1406 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1407 SCTP_CHUNK(new_obj));
1408 break;
1409
1410 case SCTP_CMD_CHUNK_ULP:
1411 /* Send a chunk to the sockets layer. */
1412 pr_debug("%s: sm_sideff: chunk_up:%p, ulpq:%p\n",
1413 __func__, cmd->obj.chunk, &asoc->ulpq);
1414
1415 sctp_ulpq_tail_data(&asoc->ulpq, cmd->obj.chunk,
1416 GFP_ATOMIC);
1417 break;
1418
1419 case SCTP_CMD_EVENT_ULP:
1420 /* Send a notification to the sockets layer. */
1421 pr_debug("%s: sm_sideff: event_up:%p, ulpq:%p\n",
1422 __func__, cmd->obj.ulpevent, &asoc->ulpq);
1423
1424 sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ulpevent);
1425 break;
1426
1427 case SCTP_CMD_REPLY:
1428 /* If an caller has not already corked, do cork. */
1429 if (!asoc->outqueue.cork) {
1430 sctp_outq_cork(&asoc->outqueue);
1431 local_cork = 1;
1432 }
1433 /* Send a chunk to our peer. */
1434 error = sctp_outq_tail(&asoc->outqueue, cmd->obj.chunk);
1435 break;
1436
1437 case SCTP_CMD_SEND_PKT:
1438 /* Send a full packet to our peer. */
1439 packet = cmd->obj.packet;
1440 sctp_packet_transmit(packet);
1441 sctp_ootb_pkt_free(packet);
1442 break;
1443
1444 case SCTP_CMD_T1_RETRAN:
1445 /* Mark a transport for retransmission. */
1446 sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1447 SCTP_RTXR_T1_RTX);
1448 break;
1449
1450 case SCTP_CMD_RETRAN:
1451 /* Mark a transport for retransmission. */
1452 sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1453 SCTP_RTXR_T3_RTX);
1454 break;
1455
1456 case SCTP_CMD_ECN_CE:
1457 /* Do delayed CE processing. */
1458 sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1459 break;
1460
1461 case SCTP_CMD_ECN_ECNE:
1462 /* Do delayed ECNE processing. */
1463 new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1464 chunk);
1465 if (new_obj)
1466 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1467 SCTP_CHUNK(new_obj));
1468 break;
1469
1470 case SCTP_CMD_ECN_CWR:
1471 /* Do delayed CWR processing. */
1472 sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1473 break;
1474
1475 case SCTP_CMD_SETUP_T2:
1476 sctp_cmd_setup_t2(commands, asoc, cmd->obj.chunk);
1477 break;
1478
1479 case SCTP_CMD_TIMER_START_ONCE:
1480 timer = &asoc->timers[cmd->obj.to];
1481
1482 if (timer_pending(timer))
1483 break;
1484 /* fall through */
1485
1486 case SCTP_CMD_TIMER_START:
1487 timer = &asoc->timers[cmd->obj.to];
1488 timeout = asoc->timeouts[cmd->obj.to];
1489 BUG_ON(!timeout);
1490
1491 timer->expires = jiffies + timeout;
1492 sctp_association_hold(asoc);
1493 add_timer(timer);
1494 break;
1495
1496 case SCTP_CMD_TIMER_RESTART:
1497 timer = &asoc->timers[cmd->obj.to];
1498 timeout = asoc->timeouts[cmd->obj.to];
1499 if (!mod_timer(timer, jiffies + timeout))
1500 sctp_association_hold(asoc);
1501 break;
1502
1503 case SCTP_CMD_TIMER_STOP:
1504 timer = &asoc->timers[cmd->obj.to];
1505 if (del_timer(timer))
1506 sctp_association_put(asoc);
1507 break;
1508
1509 case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1510 chunk = cmd->obj.chunk;
1511 t = sctp_assoc_choose_alter_transport(asoc,
1512 asoc->init_last_sent_to);
1513 asoc->init_last_sent_to = t;
1514 chunk->transport = t;
1515 t->init_sent_count++;
1516 /* Set the new transport as primary */
1517 sctp_assoc_set_primary(asoc, t);
1518 break;
1519
1520 case SCTP_CMD_INIT_RESTART:
1521 /* Do the needed accounting and updates
1522 * associated with restarting an initialization
1523 * timer. Only multiply the timeout by two if
1524 * all transports have been tried at the current
1525 * timeout.
1526 */
1527 sctp_cmd_t1_timer_update(asoc,
1528 SCTP_EVENT_TIMEOUT_T1_INIT,
1529 "INIT");
1530
1531 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1532 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1533 break;
1534
1535 case SCTP_CMD_COOKIEECHO_RESTART:
1536 /* Do the needed accounting and updates
1537 * associated with restarting an initialization
1538 * timer. Only multiply the timeout by two if
1539 * all transports have been tried at the current
1540 * timeout.
1541 */
1542 sctp_cmd_t1_timer_update(asoc,
1543 SCTP_EVENT_TIMEOUT_T1_COOKIE,
1544 "COOKIE");
1545
1546 /* If we've sent any data bundled with
1547 * COOKIE-ECHO we need to resend.
1548 */
1549 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1550 transports) {
1551 sctp_retransmit_mark(&asoc->outqueue, t,
1552 SCTP_RTXR_T1_RTX);
1553 }
1554
1555 sctp_add_cmd_sf(commands,
1556 SCTP_CMD_TIMER_RESTART,
1557 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1558 break;
1559
1560 case SCTP_CMD_INIT_FAILED:
1561 sctp_cmd_init_failed(commands, asoc, cmd->obj.err);
1562 break;
1563
1564 case SCTP_CMD_ASSOC_FAILED:
1565 sctp_cmd_assoc_failed(commands, asoc, event_type,
1566 subtype, chunk, cmd->obj.err);
1567 break;
1568
1569 case SCTP_CMD_INIT_COUNTER_INC:
1570 asoc->init_err_counter++;
1571 break;
1572
1573 case SCTP_CMD_INIT_COUNTER_RESET:
1574 asoc->init_err_counter = 0;
1575 asoc->init_cycle = 0;
1576 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1577 transports) {
1578 t->init_sent_count = 0;
1579 }
1580 break;
1581
1582 case SCTP_CMD_REPORT_DUP:
1583 sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1584 cmd->obj.u32);
1585 break;
1586
1587 case SCTP_CMD_REPORT_BAD_TAG:
1588 pr_debug("%s: vtag mismatch!\n", __func__);
1589 break;
1590
1591 case SCTP_CMD_STRIKE:
1592 /* Mark one strike against a transport. */
1593 sctp_do_8_2_transport_strike(commands, asoc,
1594 cmd->obj.transport, 0);
1595 break;
1596
1597 case SCTP_CMD_TRANSPORT_IDLE:
1598 t = cmd->obj.transport;
1599 sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
1600 break;
1601
1602 case SCTP_CMD_TRANSPORT_HB_SENT:
1603 t = cmd->obj.transport;
1604 sctp_do_8_2_transport_strike(commands, asoc,
1605 t, 1);
1606 t->hb_sent = 1;
1607 break;
1608
1609 case SCTP_CMD_TRANSPORT_ON:
1610 t = cmd->obj.transport;
1611 sctp_cmd_transport_on(commands, asoc, t, chunk);
1612 break;
1613
1614 case SCTP_CMD_HB_TIMERS_START:
1615 sctp_cmd_hb_timers_start(commands, asoc);
1616 break;
1617
1618 case SCTP_CMD_HB_TIMER_UPDATE:
1619 t = cmd->obj.transport;
1620 sctp_cmd_hb_timer_update(commands, t);
1621 break;
1622
1623 case SCTP_CMD_HB_TIMERS_STOP:
1624 sctp_cmd_hb_timers_stop(commands, asoc);
1625 break;
1626
1627 case SCTP_CMD_REPORT_ERROR:
1628 error = cmd->obj.error;
1629 break;
1630
1631 case SCTP_CMD_PROCESS_CTSN:
1632 /* Dummy up a SACK for processing. */
1633 sackh.cum_tsn_ack = cmd->obj.be32;
1634 sackh.a_rwnd = asoc->peer.rwnd +
1635 asoc->outqueue.outstanding_bytes;
1636 sackh.num_gap_ack_blocks = 0;
1637 sackh.num_dup_tsns = 0;
1638 chunk->subh.sack_hdr = &sackh;
1639 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1640 SCTP_CHUNK(chunk));
1641 break;
1642
1643 case SCTP_CMD_DISCARD_PACKET:
1644 /* We need to discard the whole packet.
1645 * Uncork the queue since there might be
1646 * responses pending
1647 */
1648 chunk->pdiscard = 1;
1649 if (asoc) {
1650 sctp_outq_uncork(&asoc->outqueue);
1651 local_cork = 0;
1652 }
1653 break;
1654
1655 case SCTP_CMD_RTO_PENDING:
1656 t = cmd->obj.transport;
1657 t->rto_pending = 1;
1658 break;
1659
1660 case SCTP_CMD_PART_DELIVER:
1661 sctp_ulpq_partial_delivery(&asoc->ulpq, GFP_ATOMIC);
1662 break;
1663
1664 case SCTP_CMD_RENEGE:
1665 sctp_ulpq_renege(&asoc->ulpq, cmd->obj.chunk,
1666 GFP_ATOMIC);
1667 break;
1668
1669 case SCTP_CMD_SETUP_T4:
1670 sctp_cmd_setup_t4(commands, asoc, cmd->obj.chunk);
1671 break;
1672
1673 case SCTP_CMD_PROCESS_OPERR:
1674 sctp_cmd_process_operr(commands, asoc, chunk);
1675 break;
1676 case SCTP_CMD_CLEAR_INIT_TAG:
1677 asoc->peer.i.init_tag = 0;
1678 break;
1679 case SCTP_CMD_DEL_NON_PRIMARY:
1680 sctp_cmd_del_non_primary(asoc);
1681 break;
1682 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1683 sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1684 break;
1685 case SCTP_CMD_FORCE_PRIM_RETRAN:
1686 t = asoc->peer.retran_path;
1687 asoc->peer.retran_path = asoc->peer.primary_path;
1688 error = sctp_outq_uncork(&asoc->outqueue);
1689 local_cork = 0;
1690 asoc->peer.retran_path = t;
1691 break;
1692 case SCTP_CMD_SET_SK_ERR:
1693 sctp_cmd_set_sk_err(asoc, cmd->obj.error);
1694 break;
1695 case SCTP_CMD_ASSOC_CHANGE:
1696 sctp_cmd_assoc_change(commands, asoc,
1697 cmd->obj.u8);
1698 break;
1699 case SCTP_CMD_ADAPTATION_IND:
1700 sctp_cmd_adaptation_ind(commands, asoc);
1701 break;
1702
1703 case SCTP_CMD_ASSOC_SHKEY:
1704 error = sctp_auth_asoc_init_active_key(asoc,
1705 GFP_ATOMIC);
1706 break;
1707 case SCTP_CMD_UPDATE_INITTAG:
1708 asoc->peer.i.init_tag = cmd->obj.u32;
1709 break;
1710 case SCTP_CMD_SEND_MSG:
1711 if (!asoc->outqueue.cork) {
1712 sctp_outq_cork(&asoc->outqueue);
1713 local_cork = 1;
1714 }
1715 error = sctp_cmd_send_msg(asoc, cmd->obj.msg);
1716 break;
1717 case SCTP_CMD_SEND_NEXT_ASCONF:
1718 sctp_cmd_send_asconf(asoc);
1719 break;
1720 case SCTP_CMD_PURGE_ASCONF_QUEUE:
1721 sctp_asconf_queue_teardown(asoc);
1722 break;
1723
1724 case SCTP_CMD_SET_ASOC:
1725 asoc = cmd->obj.asoc;
1726 break;
1727
1728 default:
1729 pr_warn("Impossible command: %u\n",
1730 cmd->verb);
1731 break;
1732 }
1733
1734 if (error)
1735 break;
1736 }
1737
1738 out:
1739 /* If this is in response to a received chunk, wait until
1740 * we are done with the packet to open the queue so that we don't
1741 * send multiple packets in response to a single request.
1742 */
1743 if (asoc && SCTP_EVENT_T_CHUNK == event_type && chunk) {
1744 if (chunk->end_of_packet || chunk->singleton)
1745 error = sctp_outq_uncork(&asoc->outqueue);
1746 } else if (local_cork)
1747 error = sctp_outq_uncork(&asoc->outqueue);
1748 return error;
1749 nomem:
1750 error = -ENOMEM;
1751 goto out;
1752 }
1753
Linus' kernel tree