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[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 /* 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 sk->sk_err = -error;
277
278 out_unlock:
279 bh_unlock_sock(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 sock *sk = asoc->base.sk;
290 struct net *net = sock_net(sk);
291 int error = 0;
292
293 bh_lock_sock(sk);
294 if (sock_owned_by_user(sk)) {
295 pr_debug("%s: sock is busy: timer %d\n", __func__,
296 timeout_type);
297
298 /* Try again later. */
299 if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20)))
300 sctp_association_hold(asoc);
301 goto out_unlock;
302 }
303
304 /* Is this association really dead and just waiting around for
305 * the timer to let go of the reference?
306 */
307 if (asoc->base.dead)
308 goto out_unlock;
309
310 /* Run through the state machine. */
311 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
312 SCTP_ST_TIMEOUT(timeout_type),
313 asoc->state, asoc->ep, asoc,
314 (void *)timeout_type, GFP_ATOMIC);
315
316 if (error)
317 sk->sk_err = -error;
318
319 out_unlock:
320 bh_unlock_sock(sk);
321 sctp_association_put(asoc);
322 }
323
324 static void sctp_generate_t1_cookie_event(unsigned long data)
325 {
326 struct sctp_association *asoc = (struct sctp_association *) data;
327 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
328 }
329
330 static void sctp_generate_t1_init_event(unsigned long data)
331 {
332 struct sctp_association *asoc = (struct sctp_association *) data;
333 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
334 }
335
336 static void sctp_generate_t2_shutdown_event(unsigned long data)
337 {
338 struct sctp_association *asoc = (struct sctp_association *) data;
339 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
340 }
341
342 static void sctp_generate_t4_rto_event(unsigned long data)
343 {
344 struct sctp_association *asoc = (struct sctp_association *) data;
345 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
346 }
347
348 static void sctp_generate_t5_shutdown_guard_event(unsigned long data)
349 {
350 struct sctp_association *asoc = (struct sctp_association *)data;
351 sctp_generate_timeout_event(asoc,
352 SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);
353
354 } /* sctp_generate_t5_shutdown_guard_event() */
355
356 static void sctp_generate_autoclose_event(unsigned long data)
357 {
358 struct sctp_association *asoc = (struct sctp_association *) data;
359 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE);
360 }
361
362 /* Generate a heart beat event. If the sock is busy, reschedule. Make
363 * sure that the transport is still valid.
364 */
365 void sctp_generate_heartbeat_event(unsigned long data)
366 {
367 int error = 0;
368 struct sctp_transport *transport = (struct sctp_transport *) data;
369 struct sctp_association *asoc = transport->asoc;
370 struct sock *sk = asoc->base.sk;
371 struct net *net = sock_net(sk);
372
373 bh_lock_sock(sk);
374 if (sock_owned_by_user(sk)) {
375 pr_debug("%s: sock is busy\n", __func__);
376
377 /* Try again later. */
378 if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20)))
379 sctp_transport_hold(transport);
380 goto out_unlock;
381 }
382
383 /* Is this structure just waiting around for us to actually
384 * get destroyed?
385 */
386 if (transport->dead)
387 goto out_unlock;
388
389 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
390 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
391 asoc->state, asoc->ep, asoc,
392 transport, GFP_ATOMIC);
393
394 if (error)
395 sk->sk_err = -error;
396
397 out_unlock:
398 bh_unlock_sock(sk);
399 sctp_transport_put(transport);
400 }
401
402 /* Handle the timeout of the ICMP protocol unreachable timer. Trigger
403 * the correct state machine transition that will close the association.
404 */
405 void sctp_generate_proto_unreach_event(unsigned long data)
406 {
407 struct sctp_transport *transport = (struct sctp_transport *) data;
408 struct sctp_association *asoc = transport->asoc;
409 struct sock *sk = asoc->base.sk;
410 struct net *net = sock_net(sk);
411
412 bh_lock_sock(sk);
413 if (sock_owned_by_user(sk)) {
414 pr_debug("%s: sock is busy\n", __func__);
415
416 /* Try again later. */
417 if (!mod_timer(&transport->proto_unreach_timer,
418 jiffies + (HZ/20)))
419 sctp_association_hold(asoc);
420 goto out_unlock;
421 }
422
423 /* Is this structure just waiting around for us to actually
424 * get destroyed?
425 */
426 if (asoc->base.dead)
427 goto out_unlock;
428
429 sctp_do_sm(net, SCTP_EVENT_T_OTHER,
430 SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH),
431 asoc->state, asoc->ep, asoc, transport, GFP_ATOMIC);
432
433 out_unlock:
434 bh_unlock_sock(sk);
435 sctp_association_put(asoc);
436 }
437
438
439 /* Inject a SACK Timeout event into the state machine. */
440 static void sctp_generate_sack_event(unsigned long data)
441 {
442 struct sctp_association *asoc = (struct sctp_association *) data;
443 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
444 }
445
446 sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
447 NULL,
448 sctp_generate_t1_cookie_event,
449 sctp_generate_t1_init_event,
450 sctp_generate_t2_shutdown_event,
451 NULL,
452 sctp_generate_t4_rto_event,
453 sctp_generate_t5_shutdown_guard_event,
454 NULL,
455 sctp_generate_sack_event,
456 sctp_generate_autoclose_event,
457 };
458
459
460 /* RFC 2960 8.2 Path Failure Detection
461 *
462 * When its peer endpoint is multi-homed, an endpoint should keep a
463 * error counter for each of the destination transport addresses of the
464 * peer endpoint.
465 *
466 * Each time the T3-rtx timer expires on any address, or when a
467 * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
468 * the error counter of that destination address will be incremented.
469 * When the value in the error counter exceeds the protocol parameter
470 * 'Path.Max.Retrans' of that destination address, the endpoint should
471 * mark the destination transport address as inactive, and a
472 * notification SHOULD be sent to the upper layer.
473 *
474 */
475 static void sctp_do_8_2_transport_strike(sctp_cmd_seq_t *commands,
476 struct sctp_association *asoc,
477 struct sctp_transport *transport,
478 int is_hb)
479 {
480 struct net *net = sock_net(asoc->base.sk);
481
482 /* The check for association's overall error counter exceeding the
483 * threshold is done in the state function.
484 */
485 /* We are here due to a timer expiration. If the timer was
486 * not a HEARTBEAT, then normal error tracking is done.
487 * If the timer was a heartbeat, we only increment error counts
488 * when we already have an outstanding HEARTBEAT that has not
489 * been acknowledged.
490 * Additionally, some tranport states inhibit error increments.
491 */
492 if (!is_hb) {
493 asoc->overall_error_count++;
494 if (transport->state != SCTP_INACTIVE)
495 transport->error_count++;
496 } else if (transport->hb_sent) {
497 if (transport->state != SCTP_UNCONFIRMED)
498 asoc->overall_error_count++;
499 if (transport->state != SCTP_INACTIVE)
500 transport->error_count++;
501 }
502
503 /* If the transport error count is greater than the pf_retrans
504 * threshold, and less than pathmaxrtx, and if the current state
505 * is SCTP_ACTIVE, then mark this transport as Partially Failed,
506 * see SCTP Quick Failover Draft, section 5.1
507 */
508 if (net->sctp.pf_enable &&
509 (transport->state == SCTP_ACTIVE) &&
510 (asoc->pf_retrans < transport->pathmaxrxt) &&
511 (transport->error_count > asoc->pf_retrans)) {
512
513 sctp_assoc_control_transport(asoc, transport,
514 SCTP_TRANSPORT_PF,
515 0);
516
517 /* Update the hb timer to resend a heartbeat every rto */
518 sctp_cmd_hb_timer_update(commands, transport);
519 }
520
521 if (transport->state != SCTP_INACTIVE &&
522 (transport->error_count > transport->pathmaxrxt)) {
523 pr_debug("%s: association:%p transport addr:%pISpc failed\n",
524 __func__, asoc, &transport->ipaddr.sa);
525
526 sctp_assoc_control_transport(asoc, transport,
527 SCTP_TRANSPORT_DOWN,
528 SCTP_FAILED_THRESHOLD);
529 }
530
531 /* E2) For the destination address for which the timer
532 * expires, set RTO <- RTO * 2 ("back off the timer"). The
533 * maximum value discussed in rule C7 above (RTO.max) may be
534 * used to provide an upper bound to this doubling operation.
535 *
536 * Special Case: the first HB doesn't trigger exponential backoff.
537 * The first unacknowledged HB triggers it. We do this with a flag
538 * that indicates that we have an outstanding HB.
539 */
540 if (!is_hb || transport->hb_sent) {
541 transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
542 sctp_max_rto(asoc, transport);
543 }
544 }
545
546 /* Worker routine to handle INIT command failure. */
547 static void sctp_cmd_init_failed(sctp_cmd_seq_t *commands,
548 struct sctp_association *asoc,
549 unsigned int error)
550 {
551 struct sctp_ulpevent *event;
552
553 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_CANT_STR_ASSOC,
554 (__u16)error, 0, 0, NULL,
555 GFP_ATOMIC);
556
557 if (event)
558 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
559 SCTP_ULPEVENT(event));
560
561 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
562 SCTP_STATE(SCTP_STATE_CLOSED));
563
564 /* SEND_FAILED sent later when cleaning up the association. */
565 asoc->outqueue.error = error;
566 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
567 }
568
569 /* Worker routine to handle SCTP_CMD_ASSOC_FAILED. */
570 static void sctp_cmd_assoc_failed(sctp_cmd_seq_t *commands,
571 struct sctp_association *asoc,
572 sctp_event_t event_type,
573 sctp_subtype_t subtype,
574 struct sctp_chunk *chunk,
575 unsigned int error)
576 {
577 struct sctp_ulpevent *event;
578 struct sctp_chunk *abort;
579 /* Cancel any partial delivery in progress. */
580 sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
581
582 if (event_type == SCTP_EVENT_T_CHUNK && subtype.chunk == SCTP_CID_ABORT)
583 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
584 (__u16)error, 0, 0, chunk,
585 GFP_ATOMIC);
586 else
587 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
588 (__u16)error, 0, 0, NULL,
589 GFP_ATOMIC);
590 if (event)
591 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
592 SCTP_ULPEVENT(event));
593
594 if (asoc->overall_error_count >= asoc->max_retrans) {
595 abort = sctp_make_violation_max_retrans(asoc, chunk);
596 if (abort)
597 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
598 SCTP_CHUNK(abort));
599 }
600
601 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
602 SCTP_STATE(SCTP_STATE_CLOSED));
603
604 /* SEND_FAILED sent later when cleaning up the association. */
605 asoc->outqueue.error = error;
606 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
607 }
608
609 /* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
610 * inside the cookie. In reality, this is only used for INIT-ACK processing
611 * since all other cases use "temporary" associations and can do all
612 * their work in statefuns directly.
613 */
614 static int sctp_cmd_process_init(sctp_cmd_seq_t *commands,
615 struct sctp_association *asoc,
616 struct sctp_chunk *chunk,
617 sctp_init_chunk_t *peer_init,
618 gfp_t gfp)
619 {
620 int error;
621
622 /* We only process the init as a sideeffect in a single
623 * case. This is when we process the INIT-ACK. If we
624 * fail during INIT processing (due to malloc problems),
625 * just return the error and stop processing the stack.
626 */
627 if (!sctp_process_init(asoc, chunk, sctp_source(chunk), peer_init, gfp))
628 error = -ENOMEM;
629 else
630 error = 0;
631
632 return error;
633 }
634
635 /* Helper function to break out starting up of heartbeat timers. */
636 static void sctp_cmd_hb_timers_start(sctp_cmd_seq_t *cmds,
637 struct sctp_association *asoc)
638 {
639 struct sctp_transport *t;
640
641 /* Start a heartbeat timer for each transport on the association.
642 * hold a reference on the transport to make sure none of
643 * the needed data structures go away.
644 */
645 list_for_each_entry(t, &asoc->peer.transport_addr_list, transports) {
646
647 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
648 sctp_transport_hold(t);
649 }
650 }
651
652 static void sctp_cmd_hb_timers_stop(sctp_cmd_seq_t *cmds,
653 struct sctp_association *asoc)
654 {
655 struct sctp_transport *t;
656
657 /* Stop all heartbeat timers. */
658
659 list_for_each_entry(t, &asoc->peer.transport_addr_list,
660 transports) {
661 if (del_timer(&t->hb_timer))
662 sctp_transport_put(t);
663 }
664 }
665
666 /* Helper function to stop any pending T3-RTX timers */
667 static void sctp_cmd_t3_rtx_timers_stop(sctp_cmd_seq_t *cmds,
668 struct sctp_association *asoc)
669 {
670 struct sctp_transport *t;
671
672 list_for_each_entry(t, &asoc->peer.transport_addr_list,
673 transports) {
674 if (del_timer(&t->T3_rtx_timer))
675 sctp_transport_put(t);
676 }
677 }
678
679
680 /* Helper function to update the heartbeat timer. */
681 static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
682 struct sctp_transport *t)
683 {
684 /* Update the heartbeat timer. */
685 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
686 sctp_transport_hold(t);
687 }
688
689 /* Helper function to handle the reception of an HEARTBEAT ACK. */
690 static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds,
691 struct sctp_association *asoc,
692 struct sctp_transport *t,
693 struct sctp_chunk *chunk)
694 {
695 sctp_sender_hb_info_t *hbinfo;
696 int was_unconfirmed = 0;
697
698 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
699 * HEARTBEAT should clear the error counter of the destination
700 * transport address to which the HEARTBEAT was sent.
701 */
702 t->error_count = 0;
703
704 /*
705 * Although RFC4960 specifies that the overall error count must
706 * be cleared when a HEARTBEAT ACK is received, we make an
707 * exception while in SHUTDOWN PENDING. If the peer keeps its
708 * window shut forever, we may never be able to transmit our
709 * outstanding data and rely on the retransmission limit be reached
710 * to shutdown the association.
711 */
712 if (t->asoc->state < SCTP_STATE_SHUTDOWN_PENDING)
713 t->asoc->overall_error_count = 0;
714
715 /* Clear the hb_sent flag to signal that we had a good
716 * acknowledgement.
717 */
718 t->hb_sent = 0;
719
720 /* Mark the destination transport address as active if it is not so
721 * marked.
722 */
723 if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED)) {
724 was_unconfirmed = 1;
725 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
726 SCTP_HEARTBEAT_SUCCESS);
727 }
728
729 if (t->state == SCTP_PF)
730 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
731 SCTP_HEARTBEAT_SUCCESS);
732
733 /* HB-ACK was received for a the proper HB. Consider this
734 * forward progress.
735 */
736 if (t->dst)
737 dst_confirm(t->dst);
738
739 /* The receiver of the HEARTBEAT ACK should also perform an
740 * RTT measurement for that destination transport address
741 * using the time value carried in the HEARTBEAT ACK chunk.
742 * If the transport's rto_pending variable has been cleared,
743 * it was most likely due to a retransmit. However, we want
744 * to re-enable it to properly update the rto.
745 */
746 if (t->rto_pending == 0)
747 t->rto_pending = 1;
748
749 hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
750 sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
751
752 /* Update the heartbeat timer. */
753 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
754 sctp_transport_hold(t);
755
756 if (was_unconfirmed && asoc->peer.transport_count == 1)
757 sctp_transport_immediate_rtx(t);
758 }
759
760
761 /* Helper function to process the process SACK command. */
762 static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds,
763 struct sctp_association *asoc,
764 struct sctp_chunk *chunk)
765 {
766 int err = 0;
767
768 if (sctp_outq_sack(&asoc->outqueue, chunk)) {
769 struct net *net = sock_net(asoc->base.sk);
770
771 /* There are no more TSNs awaiting SACK. */
772 err = sctp_do_sm(net, SCTP_EVENT_T_OTHER,
773 SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
774 asoc->state, asoc->ep, asoc, NULL,
775 GFP_ATOMIC);
776 }
777
778 return err;
779 }
780
781 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
782 * the transport for a shutdown chunk.
783 */
784 static void sctp_cmd_setup_t2(sctp_cmd_seq_t *cmds,
785 struct sctp_association *asoc,
786 struct sctp_chunk *chunk)
787 {
788 struct sctp_transport *t;
789
790 if (chunk->transport)
791 t = chunk->transport;
792 else {
793 t = sctp_assoc_choose_alter_transport(asoc,
794 asoc->shutdown_last_sent_to);
795 chunk->transport = t;
796 }
797 asoc->shutdown_last_sent_to = t;
798 asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
799 }
800
801 /* Helper function to change the state of an association. */
802 static void sctp_cmd_new_state(sctp_cmd_seq_t *cmds,
803 struct sctp_association *asoc,
804 sctp_state_t state)
805 {
806 struct sock *sk = asoc->base.sk;
807
808 asoc->state = state;
809
810 pr_debug("%s: asoc:%p[%s]\n", __func__, asoc, sctp_state_tbl[state]);
811
812 if (sctp_style(sk, TCP)) {
813 /* Change the sk->sk_state of a TCP-style socket that has
814 * successfully completed a connect() call.
815 */
816 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
817 sk->sk_state = SCTP_SS_ESTABLISHED;
818
819 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
820 if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
821 sctp_sstate(sk, ESTABLISHED))
822 sk->sk_shutdown |= RCV_SHUTDOWN;
823 }
824
825 if (sctp_state(asoc, COOKIE_WAIT)) {
826 /* Reset init timeouts since they may have been
827 * increased due to timer expirations.
828 */
829 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
830 asoc->rto_initial;
831 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
832 asoc->rto_initial;
833 }
834
835 if (sctp_state(asoc, ESTABLISHED) ||
836 sctp_state(asoc, CLOSED) ||
837 sctp_state(asoc, SHUTDOWN_RECEIVED)) {
838 /* Wake up any processes waiting in the asoc's wait queue in
839 * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
840 */
841 if (waitqueue_active(&asoc->wait))
842 wake_up_interruptible(&asoc->wait);
843
844 /* Wake up any processes waiting in the sk's sleep queue of
845 * a TCP-style or UDP-style peeled-off socket in
846 * sctp_wait_for_accept() or sctp_wait_for_packet().
847 * For a UDP-style socket, the waiters are woken up by the
848 * notifications.
849 */
850 if (!sctp_style(sk, UDP))
851 sk->sk_state_change(sk);
852 }
853 }
854
855 /* Helper function to delete an association. */
856 static void sctp_cmd_delete_tcb(sctp_cmd_seq_t *cmds,
857 struct sctp_association *asoc)
858 {
859 struct sock *sk = asoc->base.sk;
860
861 /* If it is a non-temporary association belonging to a TCP-style
862 * listening socket that is not closed, do not free it so that accept()
863 * can pick it up later.
864 */
865 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
866 (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
867 return;
868
869 sctp_association_free(asoc);
870 }
871
872 /*
873 * ADDIP Section 4.1 ASCONF Chunk Procedures
874 * A4) Start a T-4 RTO timer, using the RTO value of the selected
875 * destination address (we use active path instead of primary path just
876 * because primary path may be inactive.
877 */
878 static void sctp_cmd_setup_t4(sctp_cmd_seq_t *cmds,
879 struct sctp_association *asoc,
880 struct sctp_chunk *chunk)
881 {
882 struct sctp_transport *t;
883
884 t = sctp_assoc_choose_alter_transport(asoc, chunk->transport);
885 asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
886 chunk->transport = t;
887 }
888
889 /* Process an incoming Operation Error Chunk. */
890 static void sctp_cmd_process_operr(sctp_cmd_seq_t *cmds,
891 struct sctp_association *asoc,
892 struct sctp_chunk *chunk)
893 {
894 struct sctp_errhdr *err_hdr;
895 struct sctp_ulpevent *ev;
896
897 while (chunk->chunk_end > chunk->skb->data) {
898 err_hdr = (struct sctp_errhdr *)(chunk->skb->data);
899
900 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
901 GFP_ATOMIC);
902 if (!ev)
903 return;
904
905 sctp_ulpq_tail_event(&asoc->ulpq, ev);
906
907 switch (err_hdr->cause) {
908 case SCTP_ERROR_UNKNOWN_CHUNK:
909 {
910 sctp_chunkhdr_t *unk_chunk_hdr;
911
912 unk_chunk_hdr = (sctp_chunkhdr_t *)err_hdr->variable;
913 switch (unk_chunk_hdr->type) {
914 /* ADDIP 4.1 A9) If the peer responds to an ASCONF with
915 * an ERROR chunk reporting that it did not recognized
916 * the ASCONF chunk type, the sender of the ASCONF MUST
917 * NOT send any further ASCONF chunks and MUST stop its
918 * T-4 timer.
919 */
920 case SCTP_CID_ASCONF:
921 if (asoc->peer.asconf_capable == 0)
922 break;
923
924 asoc->peer.asconf_capable = 0;
925 sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
926 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
927 break;
928 default:
929 break;
930 }
931 break;
932 }
933 default:
934 break;
935 }
936 }
937 }
938
939 /* Process variable FWDTSN chunk information. */
940 static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq,
941 struct sctp_chunk *chunk)
942 {
943 struct sctp_fwdtsn_skip *skip;
944 /* Walk through all the skipped SSNs */
945 sctp_walk_fwdtsn(skip, chunk) {
946 sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
947 }
948 }
949
950 /* Helper function to remove the association non-primary peer
951 * transports.
952 */
953 static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
954 {
955 struct sctp_transport *t;
956 struct list_head *pos;
957 struct list_head *temp;
958
959 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
960 t = list_entry(pos, struct sctp_transport, transports);
961 if (!sctp_cmp_addr_exact(&t->ipaddr,
962 &asoc->peer.primary_addr)) {
963 sctp_assoc_rm_peer(asoc, t);
964 }
965 }
966 }
967
968 /* Helper function to set sk_err on a 1-1 style socket. */
969 static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
970 {
971 struct sock *sk = asoc->base.sk;
972
973 if (!sctp_style(sk, UDP))
974 sk->sk_err = error;
975 }
976
977 /* Helper function to generate an association change event */
978 static void sctp_cmd_assoc_change(sctp_cmd_seq_t *commands,
979 struct sctp_association *asoc,
980 u8 state)
981 {
982 struct sctp_ulpevent *ev;
983
984 ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0,
985 asoc->c.sinit_num_ostreams,
986 asoc->c.sinit_max_instreams,
987 NULL, GFP_ATOMIC);
988 if (ev)
989 sctp_ulpq_tail_event(&asoc->ulpq, ev);
990 }
991
992 /* Helper function to generate an adaptation indication event */
993 static void sctp_cmd_adaptation_ind(sctp_cmd_seq_t *commands,
994 struct sctp_association *asoc)
995 {
996 struct sctp_ulpevent *ev;
997
998 ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
999
1000 if (ev)
1001 sctp_ulpq_tail_event(&asoc->ulpq, ev);
1002 }
1003
1004
1005 static void sctp_cmd_t1_timer_update(struct sctp_association *asoc,
1006 sctp_event_timeout_t timer,
1007 char *name)
1008 {
1009 struct sctp_transport *t;
1010
1011 t = asoc->init_last_sent_to;
1012 asoc->init_err_counter++;
1013
1014 if (t->init_sent_count > (asoc->init_cycle + 1)) {
1015 asoc->timeouts[timer] *= 2;
1016 if (asoc->timeouts[timer] > asoc->max_init_timeo) {
1017 asoc->timeouts[timer] = asoc->max_init_timeo;
1018 }
1019 asoc->init_cycle++;
1020
1021 pr_debug("%s: T1[%s] timeout adjustment init_err_counter:%d"
1022 " cycle:%d timeout:%ld\n", __func__, name,
1023 asoc->init_err_counter, asoc->init_cycle,
1024 asoc->timeouts[timer]);
1025 }
1026
1027 }
1028
1029 /* Send the whole message, chunk by chunk, to the outqueue.
1030 * This way the whole message is queued up and bundling if
1031 * encouraged for small fragments.
1032 */
1033 static int sctp_cmd_send_msg(struct sctp_association *asoc,
1034 struct sctp_datamsg *msg)
1035 {
1036 struct sctp_chunk *chunk;
1037 int error = 0;
1038
1039 list_for_each_entry(chunk, &msg->chunks, frag_list) {
1040 error = sctp_outq_tail(&asoc->outqueue, chunk);
1041 if (error)
1042 break;
1043 }
1044
1045 return error;
1046 }
1047
1048
1049 /* Sent the next ASCONF packet currently stored in the association.
1050 * This happens after the ASCONF_ACK was succeffully processed.
1051 */
1052 static void sctp_cmd_send_asconf(struct sctp_association *asoc)
1053 {
1054 struct net *net = sock_net(asoc->base.sk);
1055
1056 /* Send the next asconf chunk from the addip chunk
1057 * queue.
1058 */
1059 if (!list_empty(&asoc->addip_chunk_list)) {
1060 struct list_head *entry = asoc->addip_chunk_list.next;
1061 struct sctp_chunk *asconf = list_entry(entry,
1062 struct sctp_chunk, list);
1063 list_del_init(entry);
1064
1065 /* Hold the chunk until an ASCONF_ACK is received. */
1066 sctp_chunk_hold(asconf);
1067 if (sctp_primitive_ASCONF(net, asoc, asconf))
1068 sctp_chunk_free(asconf);
1069 else
1070 asoc->addip_last_asconf = asconf;
1071 }
1072 }
1073
1074
1075 /* These three macros allow us to pull the debugging code out of the
1076 * main flow of sctp_do_sm() to keep attention focused on the real
1077 * functionality there.
1078 */
1079 #define debug_pre_sfn() \
1080 pr_debug("%s[pre-fn]: ep:%p, %s, %s, asoc:%p[%s], %s\n", __func__, \
1081 ep, sctp_evttype_tbl[event_type], (*debug_fn)(subtype), \
1082 asoc, sctp_state_tbl[state], state_fn->name)
1083
1084 #define debug_post_sfn() \
1085 pr_debug("%s[post-fn]: asoc:%p, status:%s\n", __func__, asoc, \
1086 sctp_status_tbl[status])
1087
1088 #define debug_post_sfx() \
1089 pr_debug("%s[post-sfx]: error:%d, asoc:%p[%s]\n", __func__, error, \
1090 asoc, sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
1091 sctp_assoc2id(asoc))) ? asoc->state : SCTP_STATE_CLOSED])
1092
1093 /*
1094 * This is the master state machine processing function.
1095 *
1096 * If you want to understand all of lksctp, this is a
1097 * good place to start.
1098 */
1099 int sctp_do_sm(struct net *net, sctp_event_t event_type, sctp_subtype_t subtype,
1100 sctp_state_t state,
1101 struct sctp_endpoint *ep,
1102 struct sctp_association *asoc,
1103 void *event_arg,
1104 gfp_t gfp)
1105 {
1106 sctp_cmd_seq_t commands;
1107 const sctp_sm_table_entry_t *state_fn;
1108 sctp_disposition_t status;
1109 int error = 0;
1110 typedef const char *(printfn_t)(sctp_subtype_t);
1111 static printfn_t *table[] = {
1112 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
1113 };
1114 printfn_t *debug_fn __attribute__ ((unused)) = table[event_type];
1115
1116 /* Look up the state function, run it, and then process the
1117 * side effects. These three steps are the heart of lksctp.
1118 */
1119 state_fn = sctp_sm_lookup_event(net, event_type, state, subtype);
1120
1121 sctp_init_cmd_seq(&commands);
1122
1123 debug_pre_sfn();
1124 status = state_fn->fn(net, ep, asoc, subtype, event_arg, &commands);
1125 debug_post_sfn();
1126
1127 error = sctp_side_effects(event_type, subtype, state,
1128 ep, &asoc, event_arg, status,
1129 &commands, gfp);
1130 debug_post_sfx();
1131
1132 return error;
1133 }
1134
1135 /*****************************************************************
1136 * This the master state function side effect processing function.
1137 *****************************************************************/
1138 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
1139 sctp_state_t state,
1140 struct sctp_endpoint *ep,
1141 struct sctp_association **asoc,
1142 void *event_arg,
1143 sctp_disposition_t status,
1144 sctp_cmd_seq_t *commands,
1145 gfp_t gfp)
1146 {
1147 int error;
1148
1149 /* FIXME - Most of the dispositions left today would be categorized
1150 * as "exceptional" dispositions. For those dispositions, it
1151 * may not be proper to run through any of the commands at all.
1152 * For example, the command interpreter might be run only with
1153 * disposition SCTP_DISPOSITION_CONSUME.
1154 */
1155 if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
1156 ep, *asoc,
1157 event_arg, status,
1158 commands, gfp)))
1159 goto bail;
1160
1161 switch (status) {
1162 case SCTP_DISPOSITION_DISCARD:
1163 pr_debug("%s: ignored sctp protocol event - state:%d, "
1164 "event_type:%d, event_id:%d\n", __func__, state,
1165 event_type, subtype.chunk);
1166 break;
1167
1168 case SCTP_DISPOSITION_NOMEM:
1169 /* We ran out of memory, so we need to discard this
1170 * packet.
1171 */
1172 /* BUG--we should now recover some memory, probably by
1173 * reneging...
1174 */
1175 error = -ENOMEM;
1176 break;
1177
1178 case SCTP_DISPOSITION_DELETE_TCB:
1179 case SCTP_DISPOSITION_ABORT:
1180 /* This should now be a command. */
1181 *asoc = NULL;
1182 break;
1183
1184 case SCTP_DISPOSITION_CONSUME:
1185 /*
1186 * We should no longer have much work to do here as the
1187 * real work has been done as explicit commands above.
1188 */
1189 break;
1190
1191 case SCTP_DISPOSITION_VIOLATION:
1192 net_err_ratelimited("protocol violation state %d chunkid %d\n",
1193 state, subtype.chunk);
1194 break;
1195
1196 case SCTP_DISPOSITION_NOT_IMPL:
1197 pr_warn("unimplemented feature in state %d, event_type %d, event_id %d\n",
1198 state, event_type, subtype.chunk);
1199 break;
1200
1201 case SCTP_DISPOSITION_BUG:
1202 pr_err("bug in state %d, event_type %d, event_id %d\n",
1203 state, event_type, subtype.chunk);
1204 BUG();
1205 break;
1206
1207 default:
1208 pr_err("impossible disposition %d in state %d, event_type %d, event_id %d\n",
1209 status, state, event_type, subtype.chunk);
1210 BUG();
1211 break;
1212 }
1213
1214 bail:
1215 return error;
1216 }
1217
1218 /********************************************************************
1219 * 2nd Level Abstractions
1220 ********************************************************************/
1221
1222 /* This is the side-effect interpreter. */
1223 static int sctp_cmd_interpreter(sctp_event_t event_type,
1224 sctp_subtype_t subtype,
1225 sctp_state_t state,
1226 struct sctp_endpoint *ep,
1227 struct sctp_association *asoc,
1228 void *event_arg,
1229 sctp_disposition_t status,
1230 sctp_cmd_seq_t *commands,
1231 gfp_t gfp)
1232 {
1233 int error = 0;
1234 int force;
1235 sctp_cmd_t *cmd;
1236 struct sctp_chunk *new_obj;
1237 struct sctp_chunk *chunk = NULL;
1238 struct sctp_packet *packet;
1239 struct timer_list *timer;
1240 unsigned long timeout;
1241 struct sctp_transport *t;
1242 struct sctp_sackhdr sackh;
1243 int local_cork = 0;
1244
1245 if (SCTP_EVENT_T_TIMEOUT != event_type)
1246 chunk = event_arg;
1247
1248 /* Note: This whole file is a huge candidate for rework.
1249 * For example, each command could either have its own handler, so
1250 * the loop would look like:
1251 * while (cmds)
1252 * cmd->handle(x, y, z)
1253 * --jgrimm
1254 */
1255 while (NULL != (cmd = sctp_next_cmd(commands))) {
1256 switch (cmd->verb) {
1257 case SCTP_CMD_NOP:
1258 /* Do nothing. */
1259 break;
1260
1261 case SCTP_CMD_NEW_ASOC:
1262 /* Register a new association. */
1263 if (local_cork) {
1264 sctp_outq_uncork(&asoc->outqueue);
1265 local_cork = 0;
1266 }
1267
1268 /* Register with the endpoint. */
1269 asoc = cmd->obj.asoc;
1270 BUG_ON(asoc->peer.primary_path == NULL);
1271 sctp_endpoint_add_asoc(ep, asoc);
1272 break;
1273
1274 case SCTP_CMD_UPDATE_ASSOC:
1275 sctp_assoc_update(asoc, cmd->obj.asoc);
1276 break;
1277
1278 case SCTP_CMD_PURGE_OUTQUEUE:
1279 sctp_outq_teardown(&asoc->outqueue);
1280 break;
1281
1282 case SCTP_CMD_DELETE_TCB:
1283 if (local_cork) {
1284 sctp_outq_uncork(&asoc->outqueue);
1285 local_cork = 0;
1286 }
1287 /* Delete the current association. */
1288 sctp_cmd_delete_tcb(commands, asoc);
1289 asoc = NULL;
1290 break;
1291
1292 case SCTP_CMD_NEW_STATE:
1293 /* Enter a new state. */
1294 sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1295 break;
1296
1297 case SCTP_CMD_REPORT_TSN:
1298 /* Record the arrival of a TSN. */
1299 error = sctp_tsnmap_mark(&asoc->peer.tsn_map,
1300 cmd->obj.u32, NULL);
1301 break;
1302
1303 case SCTP_CMD_REPORT_FWDTSN:
1304 /* Move the Cumulattive TSN Ack ahead. */
1305 sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32);
1306
1307 /* purge the fragmentation queue */
1308 sctp_ulpq_reasm_flushtsn(&asoc->ulpq, cmd->obj.u32);
1309
1310 /* Abort any in progress partial delivery. */
1311 sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
1312 break;
1313
1314 case SCTP_CMD_PROCESS_FWDTSN:
1315 sctp_cmd_process_fwdtsn(&asoc->ulpq, cmd->obj.chunk);
1316 break;
1317
1318 case SCTP_CMD_GEN_SACK:
1319 /* Generate a Selective ACK.
1320 * The argument tells us whether to just count
1321 * the packet and MAYBE generate a SACK, or
1322 * force a SACK out.
1323 */
1324 force = cmd->obj.i32;
1325 error = sctp_gen_sack(asoc, force, commands);
1326 break;
1327
1328 case SCTP_CMD_PROCESS_SACK:
1329 /* Process an inbound SACK. */
1330 error = sctp_cmd_process_sack(commands, asoc,
1331 cmd->obj.chunk);
1332 break;
1333
1334 case SCTP_CMD_GEN_INIT_ACK:
1335 /* Generate an INIT ACK chunk. */
1336 new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1337 0);
1338 if (!new_obj)
1339 goto nomem;
1340
1341 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1342 SCTP_CHUNK(new_obj));
1343 break;
1344
1345 case SCTP_CMD_PEER_INIT:
1346 /* Process a unified INIT from the peer.
1347 * Note: Only used during INIT-ACK processing. If
1348 * there is an error just return to the outter
1349 * layer which will bail.
1350 */
1351 error = sctp_cmd_process_init(commands, asoc, chunk,
1352 cmd->obj.init, gfp);
1353 break;
1354
1355 case SCTP_CMD_GEN_COOKIE_ECHO:
1356 /* Generate a COOKIE ECHO chunk. */
1357 new_obj = sctp_make_cookie_echo(asoc, chunk);
1358 if (!new_obj) {
1359 if (cmd->obj.chunk)
1360 sctp_chunk_free(cmd->obj.chunk);
1361 goto nomem;
1362 }
1363 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1364 SCTP_CHUNK(new_obj));
1365
1366 /* If there is an ERROR chunk to be sent along with
1367 * the COOKIE_ECHO, send it, too.
1368 */
1369 if (cmd->obj.chunk)
1370 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1371 SCTP_CHUNK(cmd->obj.chunk));
1372
1373 if (new_obj->transport) {
1374 new_obj->transport->init_sent_count++;
1375 asoc->init_last_sent_to = new_obj->transport;
1376 }
1377
1378 /* FIXME - Eventually come up with a cleaner way to
1379 * enabling COOKIE-ECHO + DATA bundling during
1380 * multihoming stale cookie scenarios, the following
1381 * command plays with asoc->peer.retran_path to
1382 * avoid the problem of sending the COOKIE-ECHO and
1383 * DATA in different paths, which could result
1384 * in the association being ABORTed if the DATA chunk
1385 * is processed first by the server. Checking the
1386 * init error counter simply causes this command
1387 * to be executed only during failed attempts of
1388 * association establishment.
1389 */
1390 if ((asoc->peer.retran_path !=
1391 asoc->peer.primary_path) &&
1392 (asoc->init_err_counter > 0)) {
1393 sctp_add_cmd_sf(commands,
1394 SCTP_CMD_FORCE_PRIM_RETRAN,
1395 SCTP_NULL());
1396 }
1397
1398 break;
1399
1400 case SCTP_CMD_GEN_SHUTDOWN:
1401 /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1402 * Reset error counts.
1403 */
1404 asoc->overall_error_count = 0;
1405
1406 /* Generate a SHUTDOWN chunk. */
1407 new_obj = sctp_make_shutdown(asoc, chunk);
1408 if (!new_obj)
1409 goto nomem;
1410 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1411 SCTP_CHUNK(new_obj));
1412 break;
1413
1414 case SCTP_CMD_CHUNK_ULP:
1415 /* Send a chunk to the sockets layer. */
1416 pr_debug("%s: sm_sideff: chunk_up:%p, ulpq:%p\n",
1417 __func__, cmd->obj.chunk, &asoc->ulpq);
1418
1419 sctp_ulpq_tail_data(&asoc->ulpq, cmd->obj.chunk,
1420 GFP_ATOMIC);
1421 break;
1422
1423 case SCTP_CMD_EVENT_ULP:
1424 /* Send a notification to the sockets layer. */
1425 pr_debug("%s: sm_sideff: event_up:%p, ulpq:%p\n",
1426 __func__, cmd->obj.ulpevent, &asoc->ulpq);
1427
1428 sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ulpevent);
1429 break;
1430
1431 case SCTP_CMD_REPLY:
1432 /* If an caller has not already corked, do cork. */
1433 if (!asoc->outqueue.cork) {
1434 sctp_outq_cork(&asoc->outqueue);
1435 local_cork = 1;
1436 }
1437 /* Send a chunk to our peer. */
1438 error = sctp_outq_tail(&asoc->outqueue, cmd->obj.chunk);
1439 break;
1440
1441 case SCTP_CMD_SEND_PKT:
1442 /* Send a full packet to our peer. */
1443 packet = cmd->obj.packet;
1444 sctp_packet_transmit(packet);
1445 sctp_ootb_pkt_free(packet);
1446 break;
1447
1448 case SCTP_CMD_T1_RETRAN:
1449 /* Mark a transport for retransmission. */
1450 sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1451 SCTP_RTXR_T1_RTX);
1452 break;
1453
1454 case SCTP_CMD_RETRAN:
1455 /* Mark a transport for retransmission. */
1456 sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1457 SCTP_RTXR_T3_RTX);
1458 break;
1459
1460 case SCTP_CMD_ECN_CE:
1461 /* Do delayed CE processing. */
1462 sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1463 break;
1464
1465 case SCTP_CMD_ECN_ECNE:
1466 /* Do delayed ECNE processing. */
1467 new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1468 chunk);
1469 if (new_obj)
1470 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1471 SCTP_CHUNK(new_obj));
1472 break;
1473
1474 case SCTP_CMD_ECN_CWR:
1475 /* Do delayed CWR processing. */
1476 sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1477 break;
1478
1479 case SCTP_CMD_SETUP_T2:
1480 sctp_cmd_setup_t2(commands, asoc, cmd->obj.chunk);
1481 break;
1482
1483 case SCTP_CMD_TIMER_START_ONCE:
1484 timer = &asoc->timers[cmd->obj.to];
1485
1486 if (timer_pending(timer))
1487 break;
1488 /* fall through */
1489
1490 case SCTP_CMD_TIMER_START:
1491 timer = &asoc->timers[cmd->obj.to];
1492 timeout = asoc->timeouts[cmd->obj.to];
1493 BUG_ON(!timeout);
1494
1495 timer->expires = jiffies + timeout;
1496 sctp_association_hold(asoc);
1497 add_timer(timer);
1498 break;
1499
1500 case SCTP_CMD_TIMER_RESTART:
1501 timer = &asoc->timers[cmd->obj.to];
1502 timeout = asoc->timeouts[cmd->obj.to];
1503 if (!mod_timer(timer, jiffies + timeout))
1504 sctp_association_hold(asoc);
1505 break;
1506
1507 case SCTP_CMD_TIMER_STOP:
1508 timer = &asoc->timers[cmd->obj.to];
1509 if (del_timer(timer))
1510 sctp_association_put(asoc);
1511 break;
1512
1513 case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1514 chunk = cmd->obj.chunk;
1515 t = sctp_assoc_choose_alter_transport(asoc,
1516 asoc->init_last_sent_to);
1517 asoc->init_last_sent_to = t;
1518 chunk->transport = t;
1519 t->init_sent_count++;
1520 /* Set the new transport as primary */
1521 sctp_assoc_set_primary(asoc, t);
1522 break;
1523
1524 case SCTP_CMD_INIT_RESTART:
1525 /* Do the needed accounting and updates
1526 * associated with restarting an initialization
1527 * timer. Only multiply the timeout by two if
1528 * all transports have been tried at the current
1529 * timeout.
1530 */
1531 sctp_cmd_t1_timer_update(asoc,
1532 SCTP_EVENT_TIMEOUT_T1_INIT,
1533 "INIT");
1534
1535 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1536 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1537 break;
1538
1539 case SCTP_CMD_COOKIEECHO_RESTART:
1540 /* Do the needed accounting and updates
1541 * associated with restarting an initialization
1542 * timer. Only multiply the timeout by two if
1543 * all transports have been tried at the current
1544 * timeout.
1545 */
1546 sctp_cmd_t1_timer_update(asoc,
1547 SCTP_EVENT_TIMEOUT_T1_COOKIE,
1548 "COOKIE");
1549
1550 /* If we've sent any data bundled with
1551 * COOKIE-ECHO we need to resend.
1552 */
1553 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1554 transports) {
1555 sctp_retransmit_mark(&asoc->outqueue, t,
1556 SCTP_RTXR_T1_RTX);
1557 }
1558
1559 sctp_add_cmd_sf(commands,
1560 SCTP_CMD_TIMER_RESTART,
1561 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1562 break;
1563
1564 case SCTP_CMD_INIT_FAILED:
1565 sctp_cmd_init_failed(commands, asoc, cmd->obj.err);
1566 break;
1567
1568 case SCTP_CMD_ASSOC_FAILED:
1569 sctp_cmd_assoc_failed(commands, asoc, event_type,
1570 subtype, chunk, cmd->obj.err);
1571 break;
1572
1573 case SCTP_CMD_INIT_COUNTER_INC:
1574 asoc->init_err_counter++;
1575 break;
1576
1577 case SCTP_CMD_INIT_COUNTER_RESET:
1578 asoc->init_err_counter = 0;
1579 asoc->init_cycle = 0;
1580 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1581 transports) {
1582 t->init_sent_count = 0;
1583 }
1584 break;
1585
1586 case SCTP_CMD_REPORT_DUP:
1587 sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1588 cmd->obj.u32);
1589 break;
1590
1591 case SCTP_CMD_REPORT_BAD_TAG:
1592 pr_debug("%s: vtag mismatch!\n", __func__);
1593 break;
1594
1595 case SCTP_CMD_STRIKE:
1596 /* Mark one strike against a transport. */
1597 sctp_do_8_2_transport_strike(commands, asoc,
1598 cmd->obj.transport, 0);
1599 break;
1600
1601 case SCTP_CMD_TRANSPORT_IDLE:
1602 t = cmd->obj.transport;
1603 sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
1604 break;
1605
1606 case SCTP_CMD_TRANSPORT_HB_SENT:
1607 t = cmd->obj.transport;
1608 sctp_do_8_2_transport_strike(commands, asoc,
1609 t, 1);
1610 t->hb_sent = 1;
1611 break;
1612
1613 case SCTP_CMD_TRANSPORT_ON:
1614 t = cmd->obj.transport;
1615 sctp_cmd_transport_on(commands, asoc, t, chunk);
1616 break;
1617
1618 case SCTP_CMD_HB_TIMERS_START:
1619 sctp_cmd_hb_timers_start(commands, asoc);
1620 break;
1621
1622 case SCTP_CMD_HB_TIMER_UPDATE:
1623 t = cmd->obj.transport;
1624 sctp_cmd_hb_timer_update(commands, t);
1625 break;
1626
1627 case SCTP_CMD_HB_TIMERS_STOP:
1628 sctp_cmd_hb_timers_stop(commands, asoc);
1629 break;
1630
1631 case SCTP_CMD_REPORT_ERROR:
1632 error = cmd->obj.error;
1633 break;
1634
1635 case SCTP_CMD_PROCESS_CTSN:
1636 /* Dummy up a SACK for processing. */
1637 sackh.cum_tsn_ack = cmd->obj.be32;
1638 sackh.a_rwnd = asoc->peer.rwnd +
1639 asoc->outqueue.outstanding_bytes;
1640 sackh.num_gap_ack_blocks = 0;
1641 sackh.num_dup_tsns = 0;
1642 chunk->subh.sack_hdr = &sackh;
1643 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1644 SCTP_CHUNK(chunk));
1645 break;
1646
1647 case SCTP_CMD_DISCARD_PACKET:
1648 /* We need to discard the whole packet.
1649 * Uncork the queue since there might be
1650 * responses pending
1651 */
1652 chunk->pdiscard = 1;
1653 if (asoc) {
1654 sctp_outq_uncork(&asoc->outqueue);
1655 local_cork = 0;
1656 }
1657 break;
1658
1659 case SCTP_CMD_RTO_PENDING:
1660 t = cmd->obj.transport;
1661 t->rto_pending = 1;
1662 break;
1663
1664 case SCTP_CMD_PART_DELIVER:
1665 sctp_ulpq_partial_delivery(&asoc->ulpq, GFP_ATOMIC);
1666 break;
1667
1668 case SCTP_CMD_RENEGE:
1669 sctp_ulpq_renege(&asoc->ulpq, cmd->obj.chunk,
1670 GFP_ATOMIC);
1671 break;
1672
1673 case SCTP_CMD_SETUP_T4:
1674 sctp_cmd_setup_t4(commands, asoc, cmd->obj.chunk);
1675 break;
1676
1677 case SCTP_CMD_PROCESS_OPERR:
1678 sctp_cmd_process_operr(commands, asoc, chunk);
1679 break;
1680 case SCTP_CMD_CLEAR_INIT_TAG:
1681 asoc->peer.i.init_tag = 0;
1682 break;
1683 case SCTP_CMD_DEL_NON_PRIMARY:
1684 sctp_cmd_del_non_primary(asoc);
1685 break;
1686 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1687 sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1688 break;
1689 case SCTP_CMD_FORCE_PRIM_RETRAN:
1690 t = asoc->peer.retran_path;
1691 asoc->peer.retran_path = asoc->peer.primary_path;
1692 error = sctp_outq_uncork(&asoc->outqueue);
1693 local_cork = 0;
1694 asoc->peer.retran_path = t;
1695 break;
1696 case SCTP_CMD_SET_SK_ERR:
1697 sctp_cmd_set_sk_err(asoc, cmd->obj.error);
1698 break;
1699 case SCTP_CMD_ASSOC_CHANGE:
1700 sctp_cmd_assoc_change(commands, asoc,
1701 cmd->obj.u8);
1702 break;
1703 case SCTP_CMD_ADAPTATION_IND:
1704 sctp_cmd_adaptation_ind(commands, asoc);
1705 break;
1706
1707 case SCTP_CMD_ASSOC_SHKEY:
1708 error = sctp_auth_asoc_init_active_key(asoc,
1709 GFP_ATOMIC);
1710 break;
1711 case SCTP_CMD_UPDATE_INITTAG:
1712 asoc->peer.i.init_tag = cmd->obj.u32;
1713 break;
1714 case SCTP_CMD_SEND_MSG:
1715 if (!asoc->outqueue.cork) {
1716 sctp_outq_cork(&asoc->outqueue);
1717 local_cork = 1;
1718 }
1719 error = sctp_cmd_send_msg(asoc, cmd->obj.msg);
1720 break;
1721 case SCTP_CMD_SEND_NEXT_ASCONF:
1722 sctp_cmd_send_asconf(asoc);
1723 break;
1724 case SCTP_CMD_PURGE_ASCONF_QUEUE:
1725 sctp_asconf_queue_teardown(asoc);
1726 break;
1727
1728 case SCTP_CMD_SET_ASOC:
1729 asoc = cmd->obj.asoc;
1730 break;
1731
1732 default:
1733 pr_warn("Impossible command: %u\n",
1734 cmd->verb);
1735 break;
1736 }
1737
1738 if (error)
1739 break;
1740 }
1741
1742 out:
1743 /* If this is in response to a received chunk, wait until
1744 * we are done with the packet to open the queue so that we don't
1745 * send multiple packets in response to a single request.
1746 */
1747 if (asoc && SCTP_EVENT_T_CHUNK == event_type && chunk) {
1748 if (chunk->end_of_packet || chunk->singleton)
1749 error = sctp_outq_uncork(&asoc->outqueue);
1750 } else if (local_cork)
1751 error = sctp_outq_uncork(&asoc->outqueue);
1752 return error;
1753 nomem:
1754 error = -ENOMEM;
1755 goto out;
1756 }
1757
Linux kernel - Deliverables
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