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sctp: remove the dead field of sctp_transport
[deliverable/linux.git] / net / sctp / sm_sideeffect.c
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
54 static 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);
63 static 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 static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
73 struct sctp_transport *t);
74 /********************************************************************
75 * Helper functions
76 ********************************************************************/
77
78 /* A helper function for delayed processing of INET ECN CE bit. */
79 static void sctp_do_ecn_ce_work(struct sctp_association *asoc,
80 __u32 lowest_tsn)
81 {
82 /* Save the TSN away for comparison when we receive CWR */
83
84 asoc->last_ecne_tsn = lowest_tsn;
85 asoc->need_ecne = 1;
86 }
87
88 /* Helper function for delayed processing of SCTP ECNE chunk. */
89 /* RFC 2960 Appendix A
90 *
91 * RFC 2481 details a specific bit for a sender to send in
92 * the header of its next outbound TCP segment to indicate to
93 * its peer that it has reduced its congestion window. This
94 * is termed the CWR bit. For SCTP the same indication is made
95 * by including the CWR chunk. This chunk contains one data
96 * element, i.e. the TSN number that was sent in the ECNE chunk.
97 * This element represents the lowest TSN number in the datagram
98 * that was originally marked with the CE bit.
99 */
100 static struct sctp_chunk *sctp_do_ecn_ecne_work(struct sctp_association *asoc,
101 __u32 lowest_tsn,
102 struct sctp_chunk *chunk)
103 {
104 struct sctp_chunk *repl;
105
106 /* Our previously transmitted packet ran into some congestion
107 * so we should take action by reducing cwnd and ssthresh
108 * and then ACK our peer that we we've done so by
109 * sending a CWR.
110 */
111
112 /* First, try to determine if we want to actually lower
113 * our cwnd variables. Only lower them if the ECNE looks more
114 * recent than the last response.
115 */
116 if (TSN_lt(asoc->last_cwr_tsn, lowest_tsn)) {
117 struct sctp_transport *transport;
118
119 /* Find which transport's congestion variables
120 * need to be adjusted.
121 */
122 transport = sctp_assoc_lookup_tsn(asoc, lowest_tsn);
123
124 /* Update the congestion variables. */
125 if (transport)
126 sctp_transport_lower_cwnd(transport,
127 SCTP_LOWER_CWND_ECNE);
128 asoc->last_cwr_tsn = lowest_tsn;
129 }
130
131 /* Always try to quiet the other end. In case of lost CWR,
132 * resend last_cwr_tsn.
133 */
134 repl = sctp_make_cwr(asoc, asoc->last_cwr_tsn, chunk);
135
136 /* If we run out of memory, it will look like a lost CWR. We'll
137 * get back in sync eventually.
138 */
139 return repl;
140 }
141
142 /* Helper function to do delayed processing of ECN CWR chunk. */
143 static void sctp_do_ecn_cwr_work(struct sctp_association *asoc,
144 __u32 lowest_tsn)
145 {
146 /* Turn off ECNE getting auto-prepended to every outgoing
147 * packet
148 */
149 asoc->need_ecne = 0;
150 }
151
152 /* Generate SACK if necessary. We call this at the end of a packet. */
153 static int sctp_gen_sack(struct sctp_association *asoc, int force,
154 sctp_cmd_seq_t *commands)
155 {
156 __u32 ctsn, max_tsn_seen;
157 struct sctp_chunk *sack;
158 struct sctp_transport *trans = asoc->peer.last_data_from;
159 int error = 0;
160
161 if (force ||
162 (!trans && (asoc->param_flags & SPP_SACKDELAY_DISABLE)) ||
163 (trans && (trans->param_flags & SPP_SACKDELAY_DISABLE)))
164 asoc->peer.sack_needed = 1;
165
166 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
167 max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
168
169 /* From 12.2 Parameters necessary per association (i.e. the TCB):
170 *
171 * Ack State : This flag indicates if the next received packet
172 * : is to be responded to with a SACK. ...
173 * : When DATA chunks are out of order, SACK's
174 * : are not delayed (see Section 6).
175 *
176 * [This is actually not mentioned in Section 6, but we
177 * implement it here anyway. --piggy]
178 */
179 if (max_tsn_seen != ctsn)
180 asoc->peer.sack_needed = 1;
181
182 /* From 6.2 Acknowledgement on Reception of DATA Chunks:
183 *
184 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically,
185 * an acknowledgement SHOULD be generated for at least every
186 * second packet (not every second DATA chunk) received, and
187 * SHOULD be generated within 200 ms of the arrival of any
188 * unacknowledged DATA chunk. ...
189 */
190 if (!asoc->peer.sack_needed) {
191 asoc->peer.sack_cnt++;
192
193 /* Set the SACK delay timeout based on the
194 * SACK delay for the last transport
195 * data was received from, or the default
196 * for the association.
197 */
198 if (trans) {
199 /* We will need a SACK for the next packet. */
200 if (asoc->peer.sack_cnt >= trans->sackfreq - 1)
201 asoc->peer.sack_needed = 1;
202
203 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
204 trans->sackdelay;
205 } else {
206 /* We will need a SACK for the next packet. */
207 if (asoc->peer.sack_cnt >= asoc->sackfreq - 1)
208 asoc->peer.sack_needed = 1;
209
210 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
211 asoc->sackdelay;
212 }
213
214 /* Restart the SACK timer. */
215 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
216 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
217 } else {
218 asoc->a_rwnd = asoc->rwnd;
219 sack = sctp_make_sack(asoc);
220 if (!sack)
221 goto nomem;
222
223 asoc->peer.sack_needed = 0;
224 asoc->peer.sack_cnt = 0;
225
226 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(sack));
227
228 /* Stop the SACK timer. */
229 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
230 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
231 }
232
233 return error;
234 nomem:
235 error = -ENOMEM;
236 return error;
237 }
238
239 /* When the T3-RTX timer expires, it calls this function to create the
240 * relevant state machine event.
241 */
242 void sctp_generate_t3_rtx_event(unsigned long peer)
243 {
244 int error;
245 struct sctp_transport *transport = (struct sctp_transport *) peer;
246 struct sctp_association *asoc = transport->asoc;
247 struct sock *sk = asoc->base.sk;
248 struct net *net = sock_net(sk);
249
250 /* Check whether a task is in the sock. */
251
252 bh_lock_sock(sk);
253 if (sock_owned_by_user(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 /* Run through the state machine. */
263 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
264 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX),
265 asoc->state,
266 asoc->ep, asoc,
267 transport, GFP_ATOMIC);
268
269 if (error)
270 sk->sk_err = -error;
271
272 out_unlock:
273 bh_unlock_sock(sk);
274 sctp_transport_put(transport);
275 }
276
277 /* This is a sa interface for producing timeout events. It works
278 * for timeouts which use the association as their parameter.
279 */
280 static void sctp_generate_timeout_event(struct sctp_association *asoc,
281 sctp_event_timeout_t timeout_type)
282 {
283 struct sock *sk = asoc->base.sk;
284 struct net *net = sock_net(sk);
285 int error = 0;
286
287 bh_lock_sock(sk);
288 if (sock_owned_by_user(sk)) {
289 pr_debug("%s: sock is busy: timer %d\n", __func__,
290 timeout_type);
291
292 /* Try again later. */
293 if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20)))
294 sctp_association_hold(asoc);
295 goto out_unlock;
296 }
297
298 /* Is this association really dead and just waiting around for
299 * the timer to let go of the reference?
300 */
301 if (asoc->base.dead)
302 goto out_unlock;
303
304 /* Run through the state machine. */
305 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
306 SCTP_ST_TIMEOUT(timeout_type),
307 asoc->state, asoc->ep, asoc,
308 (void *)timeout_type, GFP_ATOMIC);
309
310 if (error)
311 sk->sk_err = -error;
312
313 out_unlock:
314 bh_unlock_sock(sk);
315 sctp_association_put(asoc);
316 }
317
318 static void sctp_generate_t1_cookie_event(unsigned long data)
319 {
320 struct sctp_association *asoc = (struct sctp_association *) data;
321 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
322 }
323
324 static void sctp_generate_t1_init_event(unsigned long data)
325 {
326 struct sctp_association *asoc = (struct sctp_association *) data;
327 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
328 }
329
330 static void sctp_generate_t2_shutdown_event(unsigned long data)
331 {
332 struct sctp_association *asoc = (struct sctp_association *) data;
333 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
334 }
335
336 static void sctp_generate_t4_rto_event(unsigned long data)
337 {
338 struct sctp_association *asoc = (struct sctp_association *) data;
339 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
340 }
341
342 static void sctp_generate_t5_shutdown_guard_event(unsigned long data)
343 {
344 struct sctp_association *asoc = (struct sctp_association *)data;
345 sctp_generate_timeout_event(asoc,
346 SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);
347
348 } /* sctp_generate_t5_shutdown_guard_event() */
349
350 static void sctp_generate_autoclose_event(unsigned long data)
351 {
352 struct sctp_association *asoc = (struct sctp_association *) data;
353 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE);
354 }
355
356 /* Generate a heart beat event. If the sock is busy, reschedule. Make
357 * sure that the transport is still valid.
358 */
359 void sctp_generate_heartbeat_event(unsigned long data)
360 {
361 int error = 0;
362 struct sctp_transport *transport = (struct sctp_transport *) data;
363 struct sctp_association *asoc = transport->asoc;
364 struct sock *sk = asoc->base.sk;
365 struct net *net = sock_net(sk);
366
367 bh_lock_sock(sk);
368 if (sock_owned_by_user(sk)) {
369 pr_debug("%s: sock is busy\n", __func__);
370
371 /* Try again later. */
372 if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20)))
373 sctp_transport_hold(transport);
374 goto out_unlock;
375 }
376
377 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
378 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
379 asoc->state, asoc->ep, asoc,
380 transport, GFP_ATOMIC);
381
382 if (error)
383 sk->sk_err = -error;
384
385 out_unlock:
386 bh_unlock_sock(sk);
387 sctp_transport_put(transport);
388 }
389
390 /* Handle the timeout of the ICMP protocol unreachable timer. Trigger
391 * the correct state machine transition that will close the association.
392 */
393 void sctp_generate_proto_unreach_event(unsigned long data)
394 {
395 struct sctp_transport *transport = (struct sctp_transport *) data;
396 struct sctp_association *asoc = transport->asoc;
397 struct sock *sk = asoc->base.sk;
398 struct net *net = sock_net(sk);
399
400 bh_lock_sock(sk);
401 if (sock_owned_by_user(sk)) {
402 pr_debug("%s: sock is busy\n", __func__);
403
404 /* Try again later. */
405 if (!mod_timer(&transport->proto_unreach_timer,
406 jiffies + (HZ/20)))
407 sctp_association_hold(asoc);
408 goto out_unlock;
409 }
410
411 /* Is this structure just waiting around for us to actually
412 * get destroyed?
413 */
414 if (asoc->base.dead)
415 goto out_unlock;
416
417 sctp_do_sm(net, SCTP_EVENT_T_OTHER,
418 SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH),
419 asoc->state, asoc->ep, asoc, transport, GFP_ATOMIC);
420
421 out_unlock:
422 bh_unlock_sock(sk);
423 sctp_association_put(asoc);
424 }
425
426
427 /* Inject a SACK Timeout event into the state machine. */
428 static void sctp_generate_sack_event(unsigned long data)
429 {
430 struct sctp_association *asoc = (struct sctp_association *) data;
431 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
432 }
433
434 sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
435 NULL,
436 sctp_generate_t1_cookie_event,
437 sctp_generate_t1_init_event,
438 sctp_generate_t2_shutdown_event,
439 NULL,
440 sctp_generate_t4_rto_event,
441 sctp_generate_t5_shutdown_guard_event,
442 NULL,
443 sctp_generate_sack_event,
444 sctp_generate_autoclose_event,
445 };
446
447
448 /* RFC 2960 8.2 Path Failure Detection
449 *
450 * When its peer endpoint is multi-homed, an endpoint should keep a
451 * error counter for each of the destination transport addresses of the
452 * peer endpoint.
453 *
454 * Each time the T3-rtx timer expires on any address, or when a
455 * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
456 * the error counter of that destination address will be incremented.
457 * When the value in the error counter exceeds the protocol parameter
458 * 'Path.Max.Retrans' of that destination address, the endpoint should
459 * mark the destination transport address as inactive, and a
460 * notification SHOULD be sent to the upper layer.
461 *
462 */
463 static void sctp_do_8_2_transport_strike(sctp_cmd_seq_t *commands,
464 struct sctp_association *asoc,
465 struct sctp_transport *transport,
466 int is_hb)
467 {
468 struct net *net = sock_net(asoc->base.sk);
469
470 /* The check for association's overall error counter exceeding the
471 * threshold is done in the state function.
472 */
473 /* We are here due to a timer expiration. If the timer was
474 * not a HEARTBEAT, then normal error tracking is done.
475 * If the timer was a heartbeat, we only increment error counts
476 * when we already have an outstanding HEARTBEAT that has not
477 * been acknowledged.
478 * Additionally, some tranport states inhibit error increments.
479 */
480 if (!is_hb) {
481 asoc->overall_error_count++;
482 if (transport->state != SCTP_INACTIVE)
483 transport->error_count++;
484 } else if (transport->hb_sent) {
485 if (transport->state != SCTP_UNCONFIRMED)
486 asoc->overall_error_count++;
487 if (transport->state != SCTP_INACTIVE)
488 transport->error_count++;
489 }
490
491 /* If the transport error count is greater than the pf_retrans
492 * threshold, and less than pathmaxrtx, and if the current state
493 * is SCTP_ACTIVE, then mark this transport as Partially Failed,
494 * see SCTP Quick Failover Draft, section 5.1
495 */
496 if (net->sctp.pf_enable &&
497 (transport->state == SCTP_ACTIVE) &&
498 (asoc->pf_retrans < transport->pathmaxrxt) &&
499 (transport->error_count > asoc->pf_retrans)) {
500
501 sctp_assoc_control_transport(asoc, transport,
502 SCTP_TRANSPORT_PF,
503 0);
504
505 /* Update the hb timer to resend a heartbeat every rto */
506 sctp_cmd_hb_timer_update(commands, transport);
507 }
508
509 if (transport->state != SCTP_INACTIVE &&
510 (transport->error_count > transport->pathmaxrxt)) {
511 pr_debug("%s: association:%p transport addr:%pISpc failed\n",
512 __func__, asoc, &transport->ipaddr.sa);
513
514 sctp_assoc_control_transport(asoc, transport,
515 SCTP_TRANSPORT_DOWN,
516 SCTP_FAILED_THRESHOLD);
517 }
518
519 /* E2) For the destination address for which the timer
520 * expires, set RTO <- RTO * 2 ("back off the timer"). The
521 * maximum value discussed in rule C7 above (RTO.max) may be
522 * used to provide an upper bound to this doubling operation.
523 *
524 * Special Case: the first HB doesn't trigger exponential backoff.
525 * The first unacknowledged HB triggers it. We do this with a flag
526 * that indicates that we have an outstanding HB.
527 */
528 if (!is_hb || transport->hb_sent) {
529 transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
530 sctp_max_rto(asoc, transport);
531 }
532 }
533
534 /* Worker routine to handle INIT command failure. */
535 static void sctp_cmd_init_failed(sctp_cmd_seq_t *commands,
536 struct sctp_association *asoc,
537 unsigned int error)
538 {
539 struct sctp_ulpevent *event;
540
541 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_CANT_STR_ASSOC,
542 (__u16)error, 0, 0, NULL,
543 GFP_ATOMIC);
544
545 if (event)
546 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
547 SCTP_ULPEVENT(event));
548
549 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
550 SCTP_STATE(SCTP_STATE_CLOSED));
551
552 /* SEND_FAILED sent later when cleaning up the association. */
553 asoc->outqueue.error = error;
554 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
555 }
556
557 /* Worker routine to handle SCTP_CMD_ASSOC_FAILED. */
558 static void sctp_cmd_assoc_failed(sctp_cmd_seq_t *commands,
559 struct sctp_association *asoc,
560 sctp_event_t event_type,
561 sctp_subtype_t subtype,
562 struct sctp_chunk *chunk,
563 unsigned int error)
564 {
565 struct sctp_ulpevent *event;
566 struct sctp_chunk *abort;
567 /* Cancel any partial delivery in progress. */
568 sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
569
570 if (event_type == SCTP_EVENT_T_CHUNK && subtype.chunk == SCTP_CID_ABORT)
571 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
572 (__u16)error, 0, 0, chunk,
573 GFP_ATOMIC);
574 else
575 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
576 (__u16)error, 0, 0, NULL,
577 GFP_ATOMIC);
578 if (event)
579 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
580 SCTP_ULPEVENT(event));
581
582 if (asoc->overall_error_count >= asoc->max_retrans) {
583 abort = sctp_make_violation_max_retrans(asoc, chunk);
584 if (abort)
585 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
586 SCTP_CHUNK(abort));
587 }
588
589 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
590 SCTP_STATE(SCTP_STATE_CLOSED));
591
592 /* SEND_FAILED sent later when cleaning up the association. */
593 asoc->outqueue.error = error;
594 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
595 }
596
597 /* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
598 * inside the cookie. In reality, this is only used for INIT-ACK processing
599 * since all other cases use "temporary" associations and can do all
600 * their work in statefuns directly.
601 */
602 static int sctp_cmd_process_init(sctp_cmd_seq_t *commands,
603 struct sctp_association *asoc,
604 struct sctp_chunk *chunk,
605 sctp_init_chunk_t *peer_init,
606 gfp_t gfp)
607 {
608 int error;
609
610 /* We only process the init as a sideeffect in a single
611 * case. This is when we process the INIT-ACK. If we
612 * fail during INIT processing (due to malloc problems),
613 * just return the error and stop processing the stack.
614 */
615 if (!sctp_process_init(asoc, chunk, sctp_source(chunk), peer_init, gfp))
616 error = -ENOMEM;
617 else
618 error = 0;
619
620 return error;
621 }
622
623 /* Helper function to break out starting up of heartbeat timers. */
624 static void sctp_cmd_hb_timers_start(sctp_cmd_seq_t *cmds,
625 struct sctp_association *asoc)
626 {
627 struct sctp_transport *t;
628
629 /* Start a heartbeat timer for each transport on the association.
630 * hold a reference on the transport to make sure none of
631 * the needed data structures go away.
632 */
633 list_for_each_entry(t, &asoc->peer.transport_addr_list, transports) {
634
635 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
636 sctp_transport_hold(t);
637 }
638 }
639
640 static void sctp_cmd_hb_timers_stop(sctp_cmd_seq_t *cmds,
641 struct sctp_association *asoc)
642 {
643 struct sctp_transport *t;
644
645 /* Stop all heartbeat timers. */
646
647 list_for_each_entry(t, &asoc->peer.transport_addr_list,
648 transports) {
649 if (del_timer(&t->hb_timer))
650 sctp_transport_put(t);
651 }
652 }
653
654 /* Helper function to stop any pending T3-RTX timers */
655 static void sctp_cmd_t3_rtx_timers_stop(sctp_cmd_seq_t *cmds,
656 struct sctp_association *asoc)
657 {
658 struct sctp_transport *t;
659
660 list_for_each_entry(t, &asoc->peer.transport_addr_list,
661 transports) {
662 if (del_timer(&t->T3_rtx_timer))
663 sctp_transport_put(t);
664 }
665 }
666
667
668 /* Helper function to update the heartbeat timer. */
669 static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
670 struct sctp_transport *t)
671 {
672 /* Update the heartbeat timer. */
673 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
674 sctp_transport_hold(t);
675 }
676
677 /* Helper function to handle the reception of an HEARTBEAT ACK. */
678 static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds,
679 struct sctp_association *asoc,
680 struct sctp_transport *t,
681 struct sctp_chunk *chunk)
682 {
683 sctp_sender_hb_info_t *hbinfo;
684 int was_unconfirmed = 0;
685
686 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
687 * HEARTBEAT should clear the error counter of the destination
688 * transport address to which the HEARTBEAT was sent.
689 */
690 t->error_count = 0;
691
692 /*
693 * Although RFC4960 specifies that the overall error count must
694 * be cleared when a HEARTBEAT ACK is received, we make an
695 * exception while in SHUTDOWN PENDING. If the peer keeps its
696 * window shut forever, we may never be able to transmit our
697 * outstanding data and rely on the retransmission limit be reached
698 * to shutdown the association.
699 */
700 if (t->asoc->state < SCTP_STATE_SHUTDOWN_PENDING)
701 t->asoc->overall_error_count = 0;
702
703 /* Clear the hb_sent flag to signal that we had a good
704 * acknowledgement.
705 */
706 t->hb_sent = 0;
707
708 /* Mark the destination transport address as active if it is not so
709 * marked.
710 */
711 if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED)) {
712 was_unconfirmed = 1;
713 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
714 SCTP_HEARTBEAT_SUCCESS);
715 }
716
717 if (t->state == SCTP_PF)
718 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
719 SCTP_HEARTBEAT_SUCCESS);
720
721 /* HB-ACK was received for a the proper HB. Consider this
722 * forward progress.
723 */
724 if (t->dst)
725 dst_confirm(t->dst);
726
727 /* The receiver of the HEARTBEAT ACK should also perform an
728 * RTT measurement for that destination transport address
729 * using the time value carried in the HEARTBEAT ACK chunk.
730 * If the transport's rto_pending variable has been cleared,
731 * it was most likely due to a retransmit. However, we want
732 * to re-enable it to properly update the rto.
733 */
734 if (t->rto_pending == 0)
735 t->rto_pending = 1;
736
737 hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
738 sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
739
740 /* Update the heartbeat timer. */
741 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
742 sctp_transport_hold(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. */
750 static 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 */
772 static 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. */
790 static 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. */
844 static 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 */
866 static 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. */
878 static 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. */
928 static 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 */
941 static 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. */
957 static 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 */
966 static 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 */
981 static 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
993 static 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 */
1021 static int sctp_cmd_send_msg(struct sctp_association *asoc,
1022 struct sctp_datamsg *msg)
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);
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 */
1040 static 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 */
1087 int 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 *****************************************************************/
1126 static 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
1202 bail:
1203 return error;
1204 }
1205
1206 /********************************************************************
1207 * 2nd Level Abstractions
1208 ********************************************************************/
1209
1210 /* This is the side-effect interpreter. */
1211 static 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);
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);
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 break;
1428
1429 case SCTP_CMD_SEND_PKT:
1430 /* Send a full packet to our peer. */
1431 packet = cmd->obj.packet;
1432 sctp_packet_transmit(packet);
1433 sctp_ootb_pkt_free(packet);
1434 break;
1435
1436 case SCTP_CMD_T1_RETRAN:
1437 /* Mark a transport for retransmission. */
1438 sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1439 SCTP_RTXR_T1_RTX);
1440 break;
1441
1442 case SCTP_CMD_RETRAN:
1443 /* Mark a transport for retransmission. */
1444 sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1445 SCTP_RTXR_T3_RTX);
1446 break;
1447
1448 case SCTP_CMD_ECN_CE:
1449 /* Do delayed CE processing. */
1450 sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1451 break;
1452
1453 case SCTP_CMD_ECN_ECNE:
1454 /* Do delayed ECNE processing. */
1455 new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1456 chunk);
1457 if (new_obj)
1458 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1459 SCTP_CHUNK(new_obj));
1460 break;
1461
1462 case SCTP_CMD_ECN_CWR:
1463 /* Do delayed CWR processing. */
1464 sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1465 break;
1466
1467 case SCTP_CMD_SETUP_T2:
1468 sctp_cmd_setup_t2(commands, asoc, cmd->obj.chunk);
1469 break;
1470
1471 case SCTP_CMD_TIMER_START_ONCE:
1472 timer = &asoc->timers[cmd->obj.to];
1473
1474 if (timer_pending(timer))
1475 break;
1476 /* fall through */
1477
1478 case SCTP_CMD_TIMER_START:
1479 timer = &asoc->timers[cmd->obj.to];
1480 timeout = asoc->timeouts[cmd->obj.to];
1481 BUG_ON(!timeout);
1482
1483 timer->expires = jiffies + timeout;
1484 sctp_association_hold(asoc);
1485 add_timer(timer);
1486 break;
1487
1488 case SCTP_CMD_TIMER_RESTART:
1489 timer = &asoc->timers[cmd->obj.to];
1490 timeout = asoc->timeouts[cmd->obj.to];
1491 if (!mod_timer(timer, jiffies + timeout))
1492 sctp_association_hold(asoc);
1493 break;
1494
1495 case SCTP_CMD_TIMER_STOP:
1496 timer = &asoc->timers[cmd->obj.to];
1497 if (del_timer(timer))
1498 sctp_association_put(asoc);
1499 break;
1500
1501 case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1502 chunk = cmd->obj.chunk;
1503 t = sctp_assoc_choose_alter_transport(asoc,
1504 asoc->init_last_sent_to);
1505 asoc->init_last_sent_to = t;
1506 chunk->transport = t;
1507 t->init_sent_count++;
1508 /* Set the new transport as primary */
1509 sctp_assoc_set_primary(asoc, t);
1510 break;
1511
1512 case SCTP_CMD_INIT_RESTART:
1513 /* Do the needed accounting and updates
1514 * associated with restarting an initialization
1515 * timer. Only multiply the timeout by two if
1516 * all transports have been tried at the current
1517 * timeout.
1518 */
1519 sctp_cmd_t1_timer_update(asoc,
1520 SCTP_EVENT_TIMEOUT_T1_INIT,
1521 "INIT");
1522
1523 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1524 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1525 break;
1526
1527 case SCTP_CMD_COOKIEECHO_RESTART:
1528 /* Do the needed accounting and updates
1529 * associated with restarting an initialization
1530 * timer. Only multiply the timeout by two if
1531 * all transports have been tried at the current
1532 * timeout.
1533 */
1534 sctp_cmd_t1_timer_update(asoc,
1535 SCTP_EVENT_TIMEOUT_T1_COOKIE,
1536 "COOKIE");
1537
1538 /* If we've sent any data bundled with
1539 * COOKIE-ECHO we need to resend.
1540 */
1541 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1542 transports) {
1543 sctp_retransmit_mark(&asoc->outqueue, t,
1544 SCTP_RTXR_T1_RTX);
1545 }
1546
1547 sctp_add_cmd_sf(commands,
1548 SCTP_CMD_TIMER_RESTART,
1549 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1550 break;
1551
1552 case SCTP_CMD_INIT_FAILED:
1553 sctp_cmd_init_failed(commands, asoc, cmd->obj.err);
1554 break;
1555
1556 case SCTP_CMD_ASSOC_FAILED:
1557 sctp_cmd_assoc_failed(commands, asoc, event_type,
1558 subtype, chunk, cmd->obj.err);
1559 break;
1560
1561 case SCTP_CMD_INIT_COUNTER_INC:
1562 asoc->init_err_counter++;
1563 break;
1564
1565 case SCTP_CMD_INIT_COUNTER_RESET:
1566 asoc->init_err_counter = 0;
1567 asoc->init_cycle = 0;
1568 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1569 transports) {
1570 t->init_sent_count = 0;
1571 }
1572 break;
1573
1574 case SCTP_CMD_REPORT_DUP:
1575 sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1576 cmd->obj.u32);
1577 break;
1578
1579 case SCTP_CMD_REPORT_BAD_TAG:
1580 pr_debug("%s: vtag mismatch!\n", __func__);
1581 break;
1582
1583 case SCTP_CMD_STRIKE:
1584 /* Mark one strike against a transport. */
1585 sctp_do_8_2_transport_strike(commands, asoc,
1586 cmd->obj.transport, 0);
1587 break;
1588
1589 case SCTP_CMD_TRANSPORT_IDLE:
1590 t = cmd->obj.transport;
1591 sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
1592 break;
1593
1594 case SCTP_CMD_TRANSPORT_HB_SENT:
1595 t = cmd->obj.transport;
1596 sctp_do_8_2_transport_strike(commands, asoc,
1597 t, 1);
1598 t->hb_sent = 1;
1599 break;
1600
1601 case SCTP_CMD_TRANSPORT_ON:
1602 t = cmd->obj.transport;
1603 sctp_cmd_transport_on(commands, asoc, t, chunk);
1604 break;
1605
1606 case SCTP_CMD_HB_TIMERS_START:
1607 sctp_cmd_hb_timers_start(commands, asoc);
1608 break;
1609
1610 case SCTP_CMD_HB_TIMER_UPDATE:
1611 t = cmd->obj.transport;
1612 sctp_cmd_hb_timer_update(commands, t);
1613 break;
1614
1615 case SCTP_CMD_HB_TIMERS_STOP:
1616 sctp_cmd_hb_timers_stop(commands, asoc);
1617 break;
1618
1619 case SCTP_CMD_REPORT_ERROR:
1620 error = cmd->obj.error;
1621 break;
1622
1623 case SCTP_CMD_PROCESS_CTSN:
1624 /* Dummy up a SACK for processing. */
1625 sackh.cum_tsn_ack = cmd->obj.be32;
1626 sackh.a_rwnd = asoc->peer.rwnd +
1627 asoc->outqueue.outstanding_bytes;
1628 sackh.num_gap_ack_blocks = 0;
1629 sackh.num_dup_tsns = 0;
1630 chunk->subh.sack_hdr = &sackh;
1631 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1632 SCTP_CHUNK(chunk));
1633 break;
1634
1635 case SCTP_CMD_DISCARD_PACKET:
1636 /* We need to discard the whole packet.
1637 * Uncork the queue since there might be
1638 * responses pending
1639 */
1640 chunk->pdiscard = 1;
1641 if (asoc) {
1642 sctp_outq_uncork(&asoc->outqueue);
1643 local_cork = 0;
1644 }
1645 break;
1646
1647 case SCTP_CMD_RTO_PENDING:
1648 t = cmd->obj.transport;
1649 t->rto_pending = 1;
1650 break;
1651
1652 case SCTP_CMD_PART_DELIVER:
1653 sctp_ulpq_partial_delivery(&asoc->ulpq, GFP_ATOMIC);
1654 break;
1655
1656 case SCTP_CMD_RENEGE:
1657 sctp_ulpq_renege(&asoc->ulpq, cmd->obj.chunk,
1658 GFP_ATOMIC);
1659 break;
1660
1661 case SCTP_CMD_SETUP_T4:
1662 sctp_cmd_setup_t4(commands, asoc, cmd->obj.chunk);
1663 break;
1664
1665 case SCTP_CMD_PROCESS_OPERR:
1666 sctp_cmd_process_operr(commands, asoc, chunk);
1667 break;
1668 case SCTP_CMD_CLEAR_INIT_TAG:
1669 asoc->peer.i.init_tag = 0;
1670 break;
1671 case SCTP_CMD_DEL_NON_PRIMARY:
1672 sctp_cmd_del_non_primary(asoc);
1673 break;
1674 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1675 sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1676 break;
1677 case SCTP_CMD_FORCE_PRIM_RETRAN:
1678 t = asoc->peer.retran_path;
1679 asoc->peer.retran_path = asoc->peer.primary_path;
1680 error = sctp_outq_uncork(&asoc->outqueue);
1681 local_cork = 0;
1682 asoc->peer.retran_path = t;
1683 break;
1684 case SCTP_CMD_SET_SK_ERR:
1685 sctp_cmd_set_sk_err(asoc, cmd->obj.error);
1686 break;
1687 case SCTP_CMD_ASSOC_CHANGE:
1688 sctp_cmd_assoc_change(commands, asoc,
1689 cmd->obj.u8);
1690 break;
1691 case SCTP_CMD_ADAPTATION_IND:
1692 sctp_cmd_adaptation_ind(commands, asoc);
1693 break;
1694
1695 case SCTP_CMD_ASSOC_SHKEY:
1696 error = sctp_auth_asoc_init_active_key(asoc,
1697 GFP_ATOMIC);
1698 break;
1699 case SCTP_CMD_UPDATE_INITTAG:
1700 asoc->peer.i.init_tag = cmd->obj.u32;
1701 break;
1702 case SCTP_CMD_SEND_MSG:
1703 if (!asoc->outqueue.cork) {
1704 sctp_outq_cork(&asoc->outqueue);
1705 local_cork = 1;
1706 }
1707 error = sctp_cmd_send_msg(asoc, cmd->obj.msg);
1708 break;
1709 case SCTP_CMD_SEND_NEXT_ASCONF:
1710 sctp_cmd_send_asconf(asoc);
1711 break;
1712 case SCTP_CMD_PURGE_ASCONF_QUEUE:
1713 sctp_asconf_queue_teardown(asoc);
1714 break;
1715
1716 case SCTP_CMD_SET_ASOC:
1717 asoc = cmd->obj.asoc;
1718 break;
1719
1720 default:
1721 pr_warn("Impossible command: %u\n",
1722 cmd->verb);
1723 break;
1724 }
1725
1726 if (error)
1727 break;
1728 }
1729
1730 out:
1731 /* If this is in response to a received chunk, wait until
1732 * we are done with the packet to open the queue so that we don't
1733 * send multiple packets in response to a single request.
1734 */
1735 if (asoc && SCTP_EVENT_T_CHUNK == event_type && chunk) {
1736 if (chunk->end_of_packet || chunk->singleton)
1737 error = sctp_outq_uncork(&asoc->outqueue);
1738 } else if (local_cork)
1739 error = sctp_outq_uncork(&asoc->outqueue);
1740 return error;
1741 nomem:
1742 error = -ENOMEM;
1743 goto out;
1744 }
1745
Linux kernel - Deliverables
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