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1 /* SCTP kernel implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 *
6 * This file is part of the SCTP kernel implementation
7 *
8 * These functions work with the state functions in sctp_sm_statefuns.c
9 * to implement that state operations. These functions implement the
10 * steps which require modifying existing data structures.
11 *
12 * This SCTP implementation is free software;
13 * you can redistribute it and/or modify it under the terms of
14 * the GNU General Public License as published by
15 * the Free Software Foundation; either version 2, or (at your option)
16 * any later version.
17 *
18 * This SCTP implementation is distributed in the hope that it
19 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
20 * ************************
21 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
22 * See the GNU General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License
25 * along with GNU CC; see the file COPYING. If not, see
26 * <http://www.gnu.org/licenses/>.
27 *
28 * Please send any bug reports or fixes you make to the
29 * email address(es):
30 * lksctp developers <linux-sctp@vger.kernel.org>
31 *
32 * Written or modified by:
33 * La Monte H.P. Yarroll <piggy@acm.org>
34 * Karl Knutson <karl@athena.chicago.il.us>
35 * Jon Grimm <jgrimm@austin.ibm.com>
36 * Hui Huang <hui.huang@nokia.com>
37 * Dajiang Zhang <dajiang.zhang@nokia.com>
38 * Daisy Chang <daisyc@us.ibm.com>
39 * Sridhar Samudrala <sri@us.ibm.com>
40 * Ardelle Fan <ardelle.fan@intel.com>
41 */
42
43 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
44
45 #include <linux/skbuff.h>
46 #include <linux/types.h>
47 #include <linux/socket.h>
48 #include <linux/ip.h>
49 #include <linux/gfp.h>
50 #include <net/sock.h>
51 #include <net/sctp/sctp.h>
52 #include <net/sctp/sm.h>
53
54 static int sctp_cmd_interpreter(enum sctp_event event_type,
55 union sctp_subtype subtype,
56 enum sctp_state state,
57 struct sctp_endpoint *ep,
58 struct sctp_association *asoc,
59 void *event_arg,
60 enum sctp_disposition status,
61 struct sctp_cmd_seq *commands,
62 gfp_t gfp);
63 static int sctp_side_effects(enum sctp_event event_type,
64 union sctp_subtype subtype,
65 enum sctp_state state,
66 struct sctp_endpoint *ep,
67 struct sctp_association **asoc,
68 void *event_arg,
69 enum sctp_disposition status,
70 struct sctp_cmd_seq *commands,
71 gfp_t gfp);
72
73 /********************************************************************
74 * Helper functions
75 ********************************************************************/
76
77 /* A helper function for delayed processing of INET ECN CE bit. */
78 static void sctp_do_ecn_ce_work(struct sctp_association *asoc,
79 __u32 lowest_tsn)
80 {
81 /* Save the TSN away for comparison when we receive CWR */
82
83 asoc->last_ecne_tsn = lowest_tsn;
84 asoc->need_ecne = 1;
85 }
86
87 /* Helper function for delayed processing of SCTP ECNE chunk. */
88 /* RFC 2960 Appendix A
89 *
90 * RFC 2481 details a specific bit for a sender to send in
91 * the header of its next outbound TCP segment to indicate to
92 * its peer that it has reduced its congestion window. This
93 * is termed the CWR bit. For SCTP the same indication is made
94 * by including the CWR chunk. This chunk contains one data
95 * element, i.e. the TSN number that was sent in the ECNE chunk.
96 * This element represents the lowest TSN number in the datagram
97 * that was originally marked with the CE bit.
98 */
99 static struct sctp_chunk *sctp_do_ecn_ecne_work(struct sctp_association *asoc,
100 __u32 lowest_tsn,
101 struct sctp_chunk *chunk)
102 {
103 struct sctp_chunk *repl;
104
105 /* Our previously transmitted packet ran into some congestion
106 * so we should take action by reducing cwnd and ssthresh
107 * and then ACK our peer that we we've done so by
108 * sending a CWR.
109 */
110
111 /* First, try to determine if we want to actually lower
112 * our cwnd variables. Only lower them if the ECNE looks more
113 * recent than the last response.
114 */
115 if (TSN_lt(asoc->last_cwr_tsn, lowest_tsn)) {
116 struct sctp_transport *transport;
117
118 /* Find which transport's congestion variables
119 * need to be adjusted.
120 */
121 transport = sctp_assoc_lookup_tsn(asoc, lowest_tsn);
122
123 /* Update the congestion variables. */
124 if (transport)
125 sctp_transport_lower_cwnd(transport,
126 SCTP_LOWER_CWND_ECNE);
127 asoc->last_cwr_tsn = lowest_tsn;
128 }
129
130 /* Always try to quiet the other end. In case of lost CWR,
131 * resend last_cwr_tsn.
132 */
133 repl = sctp_make_cwr(asoc, asoc->last_cwr_tsn, chunk);
134
135 /* If we run out of memory, it will look like a lost CWR. We'll
136 * get back in sync eventually.
137 */
138 return repl;
139 }
140
141 /* Helper function to do delayed processing of ECN CWR chunk. */
142 static void sctp_do_ecn_cwr_work(struct sctp_association *asoc,
143 __u32 lowest_tsn)
144 {
145 /* Turn off ECNE getting auto-prepended to every outgoing
146 * packet
147 */
148 asoc->need_ecne = 0;
149 }
150
151 /* Generate SACK if necessary. We call this at the end of a packet. */
152 static int sctp_gen_sack(struct sctp_association *asoc, int force,
153 struct sctp_cmd_seq *commands)
154 {
155 struct sctp_transport *trans = asoc->peer.last_data_from;
156 __u32 ctsn, max_tsn_seen;
157 struct sctp_chunk *sack;
158 int error = 0;
159
160 if (force ||
161 (!trans && (asoc->param_flags & SPP_SACKDELAY_DISABLE)) ||
162 (trans && (trans->param_flags & SPP_SACKDELAY_DISABLE)))
163 asoc->peer.sack_needed = 1;
164
165 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
166 max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
167
168 /* From 12.2 Parameters necessary per association (i.e. the TCB):
169 *
170 * Ack State : This flag indicates if the next received packet
171 * : is to be responded to with a SACK. ...
172 * : When DATA chunks are out of order, SACK's
173 * : are not delayed (see Section 6).
174 *
175 * [This is actually not mentioned in Section 6, but we
176 * implement it here anyway. --piggy]
177 */
178 if (max_tsn_seen != ctsn)
179 asoc->peer.sack_needed = 1;
180
181 /* From 6.2 Acknowledgement on Reception of DATA Chunks:
182 *
183 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically,
184 * an acknowledgement SHOULD be generated for at least every
185 * second packet (not every second DATA chunk) received, and
186 * SHOULD be generated within 200 ms of the arrival of any
187 * unacknowledged DATA chunk. ...
188 */
189 if (!asoc->peer.sack_needed) {
190 asoc->peer.sack_cnt++;
191
192 /* Set the SACK delay timeout based on the
193 * SACK delay for the last transport
194 * data was received from, or the default
195 * for the association.
196 */
197 if (trans) {
198 /* We will need a SACK for the next packet. */
199 if (asoc->peer.sack_cnt >= trans->sackfreq - 1)
200 asoc->peer.sack_needed = 1;
201
202 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
203 trans->sackdelay;
204 } else {
205 /* We will need a SACK for the next packet. */
206 if (asoc->peer.sack_cnt >= asoc->sackfreq - 1)
207 asoc->peer.sack_needed = 1;
208
209 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
210 asoc->sackdelay;
211 }
212
213 /* Restart the SACK timer. */
214 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
215 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
216 } else {
217 __u32 old_a_rwnd = asoc->a_rwnd;
218
219 asoc->a_rwnd = asoc->rwnd;
220 sack = sctp_make_sack(asoc);
221 if (!sack) {
222 asoc->a_rwnd = old_a_rwnd;
223 goto nomem;
224 }
225
226 asoc->peer.sack_needed = 0;
227 asoc->peer.sack_cnt = 0;
228
229 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(sack));
230
231 /* Stop the SACK timer. */
232 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
233 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
234 }
235
236 return error;
237 nomem:
238 error = -ENOMEM;
239 return error;
240 }
241
242 /* When the T3-RTX timer expires, it calls this function to create the
243 * relevant state machine event.
244 */
245 void sctp_generate_t3_rtx_event(unsigned long peer)
246 {
247 struct sctp_transport *transport = (struct sctp_transport *) peer;
248 struct sctp_association *asoc = transport->asoc;
249 struct sock *sk = asoc->base.sk;
250 struct net *net = sock_net(sk);
251 int error;
252
253 /* Check whether a task is in the sock. */
254
255 bh_lock_sock(sk);
256 if (sock_owned_by_user(sk)) {
257 pr_debug("%s: sock is busy\n", __func__);
258
259 /* Try again later. */
260 if (!mod_timer(&transport->T3_rtx_timer, jiffies + (HZ/20)))
261 sctp_transport_hold(transport);
262 goto out_unlock;
263 }
264
265 /* Run through the state machine. */
266 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
267 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX),
268 asoc->state,
269 asoc->ep, asoc,
270 transport, GFP_ATOMIC);
271
272 if (error)
273 sk->sk_err = -error;
274
275 out_unlock:
276 bh_unlock_sock(sk);
277 sctp_transport_put(transport);
278 }
279
280 /* This is a sa interface for producing timeout events. It works
281 * for timeouts which use the association as their parameter.
282 */
283 static void sctp_generate_timeout_event(struct sctp_association *asoc,
284 enum sctp_event_timeout timeout_type)
285 {
286 struct sock *sk = asoc->base.sk;
287 struct net *net = sock_net(sk);
288 int error = 0;
289
290 bh_lock_sock(sk);
291 if (sock_owned_by_user(sk)) {
292 pr_debug("%s: sock is busy: timer %d\n", __func__,
293 timeout_type);
294
295 /* Try again later. */
296 if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20)))
297 sctp_association_hold(asoc);
298 goto out_unlock;
299 }
300
301 /* Is this association really dead and just waiting around for
302 * the timer to let go of the reference?
303 */
304 if (asoc->base.dead)
305 goto out_unlock;
306
307 /* Run through the state machine. */
308 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
309 SCTP_ST_TIMEOUT(timeout_type),
310 asoc->state, asoc->ep, asoc,
311 (void *)timeout_type, GFP_ATOMIC);
312
313 if (error)
314 sk->sk_err = -error;
315
316 out_unlock:
317 bh_unlock_sock(sk);
318 sctp_association_put(asoc);
319 }
320
321 static void sctp_generate_t1_cookie_event(unsigned long data)
322 {
323 struct sctp_association *asoc = (struct sctp_association *) data;
324 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
325 }
326
327 static void sctp_generate_t1_init_event(unsigned long data)
328 {
329 struct sctp_association *asoc = (struct sctp_association *) data;
330 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
331 }
332
333 static void sctp_generate_t2_shutdown_event(unsigned long data)
334 {
335 struct sctp_association *asoc = (struct sctp_association *) data;
336 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
337 }
338
339 static void sctp_generate_t4_rto_event(unsigned long data)
340 {
341 struct sctp_association *asoc = (struct sctp_association *) data;
342 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
343 }
344
345 static void sctp_generate_t5_shutdown_guard_event(unsigned long data)
346 {
347 struct sctp_association *asoc = (struct sctp_association *)data;
348 sctp_generate_timeout_event(asoc,
349 SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);
350
351 } /* sctp_generate_t5_shutdown_guard_event() */
352
353 static void sctp_generate_autoclose_event(unsigned long data)
354 {
355 struct sctp_association *asoc = (struct sctp_association *) data;
356 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE);
357 }
358
359 /* Generate a heart beat event. If the sock is busy, reschedule. Make
360 * sure that the transport is still valid.
361 */
362 void sctp_generate_heartbeat_event(unsigned long data)
363 {
364 struct sctp_transport *transport = (struct sctp_transport *) data;
365 struct sctp_association *asoc = transport->asoc;
366 struct sock *sk = asoc->base.sk;
367 struct net *net = sock_net(sk);
368 u32 elapsed, timeout;
369 int error = 0;
370
371 bh_lock_sock(sk);
372 if (sock_owned_by_user(sk)) {
373 pr_debug("%s: sock is busy\n", __func__);
374
375 /* Try again later. */
376 if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20)))
377 sctp_transport_hold(transport);
378 goto out_unlock;
379 }
380
381 /* Check if we should still send the heartbeat or reschedule */
382 elapsed = jiffies - transport->last_time_sent;
383 timeout = sctp_transport_timeout(transport);
384 if (elapsed < timeout) {
385 elapsed = timeout - elapsed;
386 if (!mod_timer(&transport->hb_timer, jiffies + elapsed))
387 sctp_transport_hold(transport);
388 goto out_unlock;
389 }
390
391 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
392 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
393 asoc->state, asoc->ep, asoc,
394 transport, GFP_ATOMIC);
395
396 if (error)
397 sk->sk_err = -error;
398
399 out_unlock:
400 bh_unlock_sock(sk);
401 sctp_transport_put(transport);
402 }
403
404 /* Handle the timeout of the ICMP protocol unreachable timer. Trigger
405 * the correct state machine transition that will close the association.
406 */
407 void sctp_generate_proto_unreach_event(unsigned long data)
408 {
409 struct sctp_transport *transport = (struct sctp_transport *)data;
410 struct sctp_association *asoc = transport->asoc;
411 struct sock *sk = asoc->base.sk;
412 struct net *net = sock_net(sk);
413
414 bh_lock_sock(sk);
415 if (sock_owned_by_user(sk)) {
416 pr_debug("%s: sock is busy\n", __func__);
417
418 /* Try again later. */
419 if (!mod_timer(&transport->proto_unreach_timer,
420 jiffies + (HZ/20)))
421 sctp_association_hold(asoc);
422 goto out_unlock;
423 }
424
425 /* Is this structure just waiting around for us to actually
426 * get destroyed?
427 */
428 if (asoc->base.dead)
429 goto out_unlock;
430
431 sctp_do_sm(net, SCTP_EVENT_T_OTHER,
432 SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH),
433 asoc->state, asoc->ep, asoc, transport, GFP_ATOMIC);
434
435 out_unlock:
436 bh_unlock_sock(sk);
437 sctp_association_put(asoc);
438 }
439
440 /* Handle the timeout of the RE-CONFIG timer. */
441 void sctp_generate_reconf_event(unsigned long data)
442 {
443 struct sctp_transport *transport = (struct sctp_transport *)data;
444 struct sctp_association *asoc = transport->asoc;
445 struct sock *sk = asoc->base.sk;
446 struct net *net = sock_net(sk);
447 int error = 0;
448
449 bh_lock_sock(sk);
450 if (sock_owned_by_user(sk)) {
451 pr_debug("%s: sock is busy\n", __func__);
452
453 /* Try again later. */
454 if (!mod_timer(&transport->reconf_timer, jiffies + (HZ / 20)))
455 sctp_transport_hold(transport);
456 goto out_unlock;
457 }
458
459 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
460 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_RECONF),
461 asoc->state, asoc->ep, asoc,
462 transport, GFP_ATOMIC);
463
464 if (error)
465 sk->sk_err = -error;
466
467 out_unlock:
468 bh_unlock_sock(sk);
469 sctp_transport_put(transport);
470 }
471
472 /* Inject a SACK Timeout event into the state machine. */
473 static void sctp_generate_sack_event(unsigned long data)
474 {
475 struct sctp_association *asoc = (struct sctp_association *)data;
476 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
477 }
478
479 sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
480 NULL,
481 sctp_generate_t1_cookie_event,
482 sctp_generate_t1_init_event,
483 sctp_generate_t2_shutdown_event,
484 NULL,
485 sctp_generate_t4_rto_event,
486 sctp_generate_t5_shutdown_guard_event,
487 NULL,
488 NULL,
489 sctp_generate_sack_event,
490 sctp_generate_autoclose_event,
491 };
492
493
494 /* RFC 2960 8.2 Path Failure Detection
495 *
496 * When its peer endpoint is multi-homed, an endpoint should keep a
497 * error counter for each of the destination transport addresses of the
498 * peer endpoint.
499 *
500 * Each time the T3-rtx timer expires on any address, or when a
501 * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
502 * the error counter of that destination address will be incremented.
503 * When the value in the error counter exceeds the protocol parameter
504 * 'Path.Max.Retrans' of that destination address, the endpoint should
505 * mark the destination transport address as inactive, and a
506 * notification SHOULD be sent to the upper layer.
507 *
508 */
509 static void sctp_do_8_2_transport_strike(struct sctp_cmd_seq *commands,
510 struct sctp_association *asoc,
511 struct sctp_transport *transport,
512 int is_hb)
513 {
514 struct net *net = sock_net(asoc->base.sk);
515
516 /* The check for association's overall error counter exceeding the
517 * threshold is done in the state function.
518 */
519 /* We are here due to a timer expiration. If the timer was
520 * not a HEARTBEAT, then normal error tracking is done.
521 * If the timer was a heartbeat, we only increment error counts
522 * when we already have an outstanding HEARTBEAT that has not
523 * been acknowledged.
524 * Additionally, some tranport states inhibit error increments.
525 */
526 if (!is_hb) {
527 asoc->overall_error_count++;
528 if (transport->state != SCTP_INACTIVE)
529 transport->error_count++;
530 } else if (transport->hb_sent) {
531 if (transport->state != SCTP_UNCONFIRMED)
532 asoc->overall_error_count++;
533 if (transport->state != SCTP_INACTIVE)
534 transport->error_count++;
535 }
536
537 /* If the transport error count is greater than the pf_retrans
538 * threshold, and less than pathmaxrtx, and if the current state
539 * is SCTP_ACTIVE, then mark this transport as Partially Failed,
540 * see SCTP Quick Failover Draft, section 5.1
541 */
542 if (net->sctp.pf_enable &&
543 (transport->state == SCTP_ACTIVE) &&
544 (asoc->pf_retrans < transport->pathmaxrxt) &&
545 (transport->error_count > asoc->pf_retrans)) {
546
547 sctp_assoc_control_transport(asoc, transport,
548 SCTP_TRANSPORT_PF,
549 0);
550
551 /* Update the hb timer to resend a heartbeat every rto */
552 sctp_transport_reset_hb_timer(transport);
553 }
554
555 if (transport->state != SCTP_INACTIVE &&
556 (transport->error_count > transport->pathmaxrxt)) {
557 pr_debug("%s: association:%p transport addr:%pISpc failed\n",
558 __func__, asoc, &transport->ipaddr.sa);
559
560 sctp_assoc_control_transport(asoc, transport,
561 SCTP_TRANSPORT_DOWN,
562 SCTP_FAILED_THRESHOLD);
563 }
564
565 /* E2) For the destination address for which the timer
566 * expires, set RTO <- RTO * 2 ("back off the timer"). The
567 * maximum value discussed in rule C7 above (RTO.max) may be
568 * used to provide an upper bound to this doubling operation.
569 *
570 * Special Case: the first HB doesn't trigger exponential backoff.
571 * The first unacknowledged HB triggers it. We do this with a flag
572 * that indicates that we have an outstanding HB.
573 */
574 if (!is_hb || transport->hb_sent) {
575 transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
576 sctp_max_rto(asoc, transport);
577 }
578 }
579
580 /* Worker routine to handle INIT command failure. */
581 static void sctp_cmd_init_failed(struct sctp_cmd_seq *commands,
582 struct sctp_association *asoc,
583 unsigned int error)
584 {
585 struct sctp_ulpevent *event;
586
587 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_CANT_STR_ASSOC,
588 (__u16)error, 0, 0, NULL,
589 GFP_ATOMIC);
590
591 if (event)
592 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
593 SCTP_ULPEVENT(event));
594
595 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
596 SCTP_STATE(SCTP_STATE_CLOSED));
597
598 /* SEND_FAILED sent later when cleaning up the association. */
599 asoc->outqueue.error = error;
600 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
601 }
602
603 /* Worker routine to handle SCTP_CMD_ASSOC_FAILED. */
604 static void sctp_cmd_assoc_failed(struct sctp_cmd_seq *commands,
605 struct sctp_association *asoc,
606 enum sctp_event event_type,
607 union sctp_subtype subtype,
608 struct sctp_chunk *chunk,
609 unsigned int error)
610 {
611 struct sctp_ulpevent *event;
612 struct sctp_chunk *abort;
613
614 /* Cancel any partial delivery in progress. */
615 sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
616
617 if (event_type == SCTP_EVENT_T_CHUNK && subtype.chunk == SCTP_CID_ABORT)
618 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
619 (__u16)error, 0, 0, chunk,
620 GFP_ATOMIC);
621 else
622 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
623 (__u16)error, 0, 0, NULL,
624 GFP_ATOMIC);
625 if (event)
626 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
627 SCTP_ULPEVENT(event));
628
629 if (asoc->overall_error_count >= asoc->max_retrans) {
630 abort = sctp_make_violation_max_retrans(asoc, chunk);
631 if (abort)
632 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
633 SCTP_CHUNK(abort));
634 }
635
636 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
637 SCTP_STATE(SCTP_STATE_CLOSED));
638
639 /* SEND_FAILED sent later when cleaning up the association. */
640 asoc->outqueue.error = error;
641 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
642 }
643
644 /* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
645 * inside the cookie. In reality, this is only used for INIT-ACK processing
646 * since all other cases use "temporary" associations and can do all
647 * their work in statefuns directly.
648 */
649 static int sctp_cmd_process_init(struct sctp_cmd_seq *commands,
650 struct sctp_association *asoc,
651 struct sctp_chunk *chunk,
652 struct sctp_init_chunk *peer_init,
653 gfp_t gfp)
654 {
655 int error;
656
657 /* We only process the init as a sideeffect in a single
658 * case. This is when we process the INIT-ACK. If we
659 * fail during INIT processing (due to malloc problems),
660 * just return the error and stop processing the stack.
661 */
662 if (!sctp_process_init(asoc, chunk, sctp_source(chunk), peer_init, gfp))
663 error = -ENOMEM;
664 else
665 error = 0;
666
667 return error;
668 }
669
670 /* Helper function to break out starting up of heartbeat timers. */
671 static void sctp_cmd_hb_timers_start(struct sctp_cmd_seq *cmds,
672 struct sctp_association *asoc)
673 {
674 struct sctp_transport *t;
675
676 /* Start a heartbeat timer for each transport on the association.
677 * hold a reference on the transport to make sure none of
678 * the needed data structures go away.
679 */
680 list_for_each_entry(t, &asoc->peer.transport_addr_list, transports)
681 sctp_transport_reset_hb_timer(t);
682 }
683
684 static void sctp_cmd_hb_timers_stop(struct sctp_cmd_seq *cmds,
685 struct sctp_association *asoc)
686 {
687 struct sctp_transport *t;
688
689 /* Stop all heartbeat timers. */
690
691 list_for_each_entry(t, &asoc->peer.transport_addr_list,
692 transports) {
693 if (del_timer(&t->hb_timer))
694 sctp_transport_put(t);
695 }
696 }
697
698 /* Helper function to stop any pending T3-RTX timers */
699 static void sctp_cmd_t3_rtx_timers_stop(struct sctp_cmd_seq *cmds,
700 struct sctp_association *asoc)
701 {
702 struct sctp_transport *t;
703
704 list_for_each_entry(t, &asoc->peer.transport_addr_list,
705 transports) {
706 if (del_timer(&t->T3_rtx_timer))
707 sctp_transport_put(t);
708 }
709 }
710
711
712 /* Helper function to handle the reception of an HEARTBEAT ACK. */
713 static void sctp_cmd_transport_on(struct sctp_cmd_seq *cmds,
714 struct sctp_association *asoc,
715 struct sctp_transport *t,
716 struct sctp_chunk *chunk)
717 {
718 struct sctp_sender_hb_info *hbinfo;
719 int was_unconfirmed = 0;
720
721 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
722 * HEARTBEAT should clear the error counter of the destination
723 * transport address to which the HEARTBEAT was sent.
724 */
725 t->error_count = 0;
726
727 /*
728 * Although RFC4960 specifies that the overall error count must
729 * be cleared when a HEARTBEAT ACK is received, we make an
730 * exception while in SHUTDOWN PENDING. If the peer keeps its
731 * window shut forever, we may never be able to transmit our
732 * outstanding data and rely on the retransmission limit be reached
733 * to shutdown the association.
734 */
735 if (t->asoc->state < SCTP_STATE_SHUTDOWN_PENDING)
736 t->asoc->overall_error_count = 0;
737
738 /* Clear the hb_sent flag to signal that we had a good
739 * acknowledgement.
740 */
741 t->hb_sent = 0;
742
743 /* Mark the destination transport address as active if it is not so
744 * marked.
745 */
746 if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED)) {
747 was_unconfirmed = 1;
748 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
749 SCTP_HEARTBEAT_SUCCESS);
750 }
751
752 if (t->state == SCTP_PF)
753 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
754 SCTP_HEARTBEAT_SUCCESS);
755
756 /* HB-ACK was received for a the proper HB. Consider this
757 * forward progress.
758 */
759 if (t->dst)
760 sctp_transport_dst_confirm(t);
761
762 /* The receiver of the HEARTBEAT ACK should also perform an
763 * RTT measurement for that destination transport address
764 * using the time value carried in the HEARTBEAT ACK chunk.
765 * If the transport's rto_pending variable has been cleared,
766 * it was most likely due to a retransmit. However, we want
767 * to re-enable it to properly update the rto.
768 */
769 if (t->rto_pending == 0)
770 t->rto_pending = 1;
771
772 hbinfo = (struct sctp_sender_hb_info *)chunk->skb->data;
773 sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
774
775 /* Update the heartbeat timer. */
776 sctp_transport_reset_hb_timer(t);
777
778 if (was_unconfirmed && asoc->peer.transport_count == 1)
779 sctp_transport_immediate_rtx(t);
780 }
781
782
783 /* Helper function to process the process SACK command. */
784 static int sctp_cmd_process_sack(struct sctp_cmd_seq *cmds,
785 struct sctp_association *asoc,
786 struct sctp_chunk *chunk)
787 {
788 int err = 0;
789
790 if (sctp_outq_sack(&asoc->outqueue, chunk)) {
791 struct net *net = sock_net(asoc->base.sk);
792
793 /* There are no more TSNs awaiting SACK. */
794 err = sctp_do_sm(net, SCTP_EVENT_T_OTHER,
795 SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
796 asoc->state, asoc->ep, asoc, NULL,
797 GFP_ATOMIC);
798 }
799
800 return err;
801 }
802
803 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
804 * the transport for a shutdown chunk.
805 */
806 static void sctp_cmd_setup_t2(struct sctp_cmd_seq *cmds,
807 struct sctp_association *asoc,
808 struct sctp_chunk *chunk)
809 {
810 struct sctp_transport *t;
811
812 if (chunk->transport)
813 t = chunk->transport;
814 else {
815 t = sctp_assoc_choose_alter_transport(asoc,
816 asoc->shutdown_last_sent_to);
817 chunk->transport = t;
818 }
819 asoc->shutdown_last_sent_to = t;
820 asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
821 }
822
823 static void sctp_cmd_assoc_update(struct sctp_cmd_seq *cmds,
824 struct sctp_association *asoc,
825 struct sctp_association *new)
826 {
827 struct net *net = sock_net(asoc->base.sk);
828 struct sctp_chunk *abort;
829
830 if (!sctp_assoc_update(asoc, new))
831 return;
832
833 abort = sctp_make_abort(asoc, NULL, sizeof(struct sctp_errhdr));
834 if (abort) {
835 sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0);
836 sctp_add_cmd_sf(cmds, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
837 }
838 sctp_add_cmd_sf(cmds, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNABORTED));
839 sctp_add_cmd_sf(cmds, SCTP_CMD_ASSOC_FAILED,
840 SCTP_PERR(SCTP_ERROR_RSRC_LOW));
841 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
842 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
843 }
844
845 /* Helper function to change the state of an association. */
846 static void sctp_cmd_new_state(struct sctp_cmd_seq *cmds,
847 struct sctp_association *asoc,
848 enum sctp_state state)
849 {
850 struct sock *sk = asoc->base.sk;
851
852 asoc->state = state;
853
854 pr_debug("%s: asoc:%p[%s]\n", __func__, asoc, sctp_state_tbl[state]);
855
856 if (sctp_style(sk, TCP)) {
857 /* Change the sk->sk_state of a TCP-style socket that has
858 * successfully completed a connect() call.
859 */
860 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
861 sk->sk_state = SCTP_SS_ESTABLISHED;
862
863 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
864 if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
865 sctp_sstate(sk, ESTABLISHED)) {
866 sk->sk_state = SCTP_SS_CLOSING;
867 sk->sk_shutdown |= RCV_SHUTDOWN;
868 }
869 }
870
871 if (sctp_state(asoc, COOKIE_WAIT)) {
872 /* Reset init timeouts since they may have been
873 * increased due to timer expirations.
874 */
875 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
876 asoc->rto_initial;
877 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
878 asoc->rto_initial;
879 }
880
881 if (sctp_state(asoc, ESTABLISHED) ||
882 sctp_state(asoc, CLOSED) ||
883 sctp_state(asoc, SHUTDOWN_RECEIVED)) {
884 /* Wake up any processes waiting in the asoc's wait queue in
885 * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
886 */
887 if (waitqueue_active(&asoc->wait))
888 wake_up_interruptible(&asoc->wait);
889
890 /* Wake up any processes waiting in the sk's sleep queue of
891 * a TCP-style or UDP-style peeled-off socket in
892 * sctp_wait_for_accept() or sctp_wait_for_packet().
893 * For a UDP-style socket, the waiters are woken up by the
894 * notifications.
895 */
896 if (!sctp_style(sk, UDP))
897 sk->sk_state_change(sk);
898 }
899
900 if (sctp_state(asoc, SHUTDOWN_PENDING) &&
901 !sctp_outq_is_empty(&asoc->outqueue))
902 sctp_outq_uncork(&asoc->outqueue, GFP_ATOMIC);
903 }
904
905 /* Helper function to delete an association. */
906 static void sctp_cmd_delete_tcb(struct sctp_cmd_seq *cmds,
907 struct sctp_association *asoc)
908 {
909 struct sock *sk = asoc->base.sk;
910
911 /* If it is a non-temporary association belonging to a TCP-style
912 * listening socket that is not closed, do not free it so that accept()
913 * can pick it up later.
914 */
915 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
916 (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
917 return;
918
919 sctp_association_free(asoc);
920 }
921
922 /*
923 * ADDIP Section 4.1 ASCONF Chunk Procedures
924 * A4) Start a T-4 RTO timer, using the RTO value of the selected
925 * destination address (we use active path instead of primary path just
926 * because primary path may be inactive.
927 */
928 static void sctp_cmd_setup_t4(struct sctp_cmd_seq *cmds,
929 struct sctp_association *asoc,
930 struct sctp_chunk *chunk)
931 {
932 struct sctp_transport *t;
933
934 t = sctp_assoc_choose_alter_transport(asoc, chunk->transport);
935 asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
936 chunk->transport = t;
937 }
938
939 /* Process an incoming Operation Error Chunk. */
940 static void sctp_cmd_process_operr(struct sctp_cmd_seq *cmds,
941 struct sctp_association *asoc,
942 struct sctp_chunk *chunk)
943 {
944 struct sctp_errhdr *err_hdr;
945 struct sctp_ulpevent *ev;
946
947 while (chunk->chunk_end > chunk->skb->data) {
948 err_hdr = (struct sctp_errhdr *)(chunk->skb->data);
949
950 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
951 GFP_ATOMIC);
952 if (!ev)
953 return;
954
955 sctp_ulpq_tail_event(&asoc->ulpq, ev);
956
957 switch (err_hdr->cause) {
958 case SCTP_ERROR_UNKNOWN_CHUNK:
959 {
960 struct sctp_chunkhdr *unk_chunk_hdr;
961
962 unk_chunk_hdr = (struct sctp_chunkhdr *)
963 err_hdr->variable;
964 switch (unk_chunk_hdr->type) {
965 /* ADDIP 4.1 A9) If the peer responds to an ASCONF with
966 * an ERROR chunk reporting that it did not recognized
967 * the ASCONF chunk type, the sender of the ASCONF MUST
968 * NOT send any further ASCONF chunks and MUST stop its
969 * T-4 timer.
970 */
971 case SCTP_CID_ASCONF:
972 if (asoc->peer.asconf_capable == 0)
973 break;
974
975 asoc->peer.asconf_capable = 0;
976 sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
977 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
978 break;
979 default:
980 break;
981 }
982 break;
983 }
984 default:
985 break;
986 }
987 }
988 }
989
990 /* Process variable FWDTSN chunk information. */
991 static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq,
992 struct sctp_chunk *chunk)
993 {
994 struct sctp_fwdtsn_skip *skip;
995
996 /* Walk through all the skipped SSNs */
997 sctp_walk_fwdtsn(skip, chunk) {
998 sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
999 }
1000 }
1001
1002 /* Helper function to remove the association non-primary peer
1003 * transports.
1004 */
1005 static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
1006 {
1007 struct sctp_transport *t;
1008 struct list_head *temp;
1009 struct list_head *pos;
1010
1011 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
1012 t = list_entry(pos, struct sctp_transport, transports);
1013 if (!sctp_cmp_addr_exact(&t->ipaddr,
1014 &asoc->peer.primary_addr)) {
1015 sctp_assoc_rm_peer(asoc, t);
1016 }
1017 }
1018 }
1019
1020 /* Helper function to set sk_err on a 1-1 style socket. */
1021 static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
1022 {
1023 struct sock *sk = asoc->base.sk;
1024
1025 if (!sctp_style(sk, UDP))
1026 sk->sk_err = error;
1027 }
1028
1029 /* Helper function to generate an association change event */
1030 static void sctp_cmd_assoc_change(struct sctp_cmd_seq *commands,
1031 struct sctp_association *asoc,
1032 u8 state)
1033 {
1034 struct sctp_ulpevent *ev;
1035
1036 ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0,
1037 asoc->c.sinit_num_ostreams,
1038 asoc->c.sinit_max_instreams,
1039 NULL, GFP_ATOMIC);
1040 if (ev)
1041 sctp_ulpq_tail_event(&asoc->ulpq, ev);
1042 }
1043
1044 /* Helper function to generate an adaptation indication event */
1045 static void sctp_cmd_adaptation_ind(struct sctp_cmd_seq *commands,
1046 struct sctp_association *asoc)
1047 {
1048 struct sctp_ulpevent *ev;
1049
1050 ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
1051
1052 if (ev)
1053 sctp_ulpq_tail_event(&asoc->ulpq, ev);
1054 }
1055
1056
1057 static void sctp_cmd_t1_timer_update(struct sctp_association *asoc,
1058 enum sctp_event_timeout timer,
1059 char *name)
1060 {
1061 struct sctp_transport *t;
1062
1063 t = asoc->init_last_sent_to;
1064 asoc->init_err_counter++;
1065
1066 if (t->init_sent_count > (asoc->init_cycle + 1)) {
1067 asoc->timeouts[timer] *= 2;
1068 if (asoc->timeouts[timer] > asoc->max_init_timeo) {
1069 asoc->timeouts[timer] = asoc->max_init_timeo;
1070 }
1071 asoc->init_cycle++;
1072
1073 pr_debug("%s: T1[%s] timeout adjustment init_err_counter:%d"
1074 " cycle:%d timeout:%ld\n", __func__, name,
1075 asoc->init_err_counter, asoc->init_cycle,
1076 asoc->timeouts[timer]);
1077 }
1078
1079 }
1080
1081 /* Send the whole message, chunk by chunk, to the outqueue.
1082 * This way the whole message is queued up and bundling if
1083 * encouraged for small fragments.
1084 */
1085 static void sctp_cmd_send_msg(struct sctp_association *asoc,
1086 struct sctp_datamsg *msg, gfp_t gfp)
1087 {
1088 struct sctp_chunk *chunk;
1089
1090 list_for_each_entry(chunk, &msg->chunks, frag_list)
1091 sctp_outq_tail(&asoc->outqueue, chunk, gfp);
1092 }
1093
1094
1095 /* Sent the next ASCONF packet currently stored in the association.
1096 * This happens after the ASCONF_ACK was succeffully processed.
1097 */
1098 static void sctp_cmd_send_asconf(struct sctp_association *asoc)
1099 {
1100 struct net *net = sock_net(asoc->base.sk);
1101
1102 /* Send the next asconf chunk from the addip chunk
1103 * queue.
1104 */
1105 if (!list_empty(&asoc->addip_chunk_list)) {
1106 struct list_head *entry = asoc->addip_chunk_list.next;
1107 struct sctp_chunk *asconf = list_entry(entry,
1108 struct sctp_chunk, list);
1109 list_del_init(entry);
1110
1111 /* Hold the chunk until an ASCONF_ACK is received. */
1112 sctp_chunk_hold(asconf);
1113 if (sctp_primitive_ASCONF(net, asoc, asconf))
1114 sctp_chunk_free(asconf);
1115 else
1116 asoc->addip_last_asconf = asconf;
1117 }
1118 }
1119
1120
1121 /* These three macros allow us to pull the debugging code out of the
1122 * main flow of sctp_do_sm() to keep attention focused on the real
1123 * functionality there.
1124 */
1125 #define debug_pre_sfn() \
1126 pr_debug("%s[pre-fn]: ep:%p, %s, %s, asoc:%p[%s], %s\n", __func__, \
1127 ep, sctp_evttype_tbl[event_type], (*debug_fn)(subtype), \
1128 asoc, sctp_state_tbl[state], state_fn->name)
1129
1130 #define debug_post_sfn() \
1131 pr_debug("%s[post-fn]: asoc:%p, status:%s\n", __func__, asoc, \
1132 sctp_status_tbl[status])
1133
1134 #define debug_post_sfx() \
1135 pr_debug("%s[post-sfx]: error:%d, asoc:%p[%s]\n", __func__, error, \
1136 asoc, sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
1137 sctp_assoc2id(asoc))) ? asoc->state : SCTP_STATE_CLOSED])
1138
1139 /*
1140 * This is the master state machine processing function.
1141 *
1142 * If you want to understand all of lksctp, this is a
1143 * good place to start.
1144 */
1145 int sctp_do_sm(struct net *net, enum sctp_event event_type,
1146 union sctp_subtype subtype, enum sctp_state state,
1147 struct sctp_endpoint *ep, struct sctp_association *asoc,
1148 void *event_arg, gfp_t gfp)
1149 {
1150 typedef const char *(printfn_t)(union sctp_subtype);
1151 static printfn_t *table[] = {
1152 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
1153 };
1154 printfn_t *debug_fn __attribute__ ((unused)) = table[event_type];
1155 const struct sctp_sm_table_entry *state_fn;
1156 struct sctp_cmd_seq commands;
1157 enum sctp_disposition status;
1158 int error = 0;
1159
1160 /* Look up the state function, run it, and then process the
1161 * side effects. These three steps are the heart of lksctp.
1162 */
1163 state_fn = sctp_sm_lookup_event(net, event_type, state, subtype);
1164
1165 sctp_init_cmd_seq(&commands);
1166
1167 debug_pre_sfn();
1168 status = state_fn->fn(net, ep, asoc, subtype, event_arg, &commands);
1169 debug_post_sfn();
1170
1171 error = sctp_side_effects(event_type, subtype, state,
1172 ep, &asoc, event_arg, status,
1173 &commands, gfp);
1174 debug_post_sfx();
1175
1176 return error;
1177 }
1178
1179 /*****************************************************************
1180 * This the master state function side effect processing function.
1181 *****************************************************************/
1182 static int sctp_side_effects(enum sctp_event event_type,
1183 union sctp_subtype subtype,
1184 enum sctp_state state,
1185 struct sctp_endpoint *ep,
1186 struct sctp_association **asoc,
1187 void *event_arg,
1188 enum sctp_disposition status,
1189 struct sctp_cmd_seq *commands,
1190 gfp_t gfp)
1191 {
1192 int error;
1193
1194 /* FIXME - Most of the dispositions left today would be categorized
1195 * as "exceptional" dispositions. For those dispositions, it
1196 * may not be proper to run through any of the commands at all.
1197 * For example, the command interpreter might be run only with
1198 * disposition SCTP_DISPOSITION_CONSUME.
1199 */
1200 if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
1201 ep, *asoc,
1202 event_arg, status,
1203 commands, gfp)))
1204 goto bail;
1205
1206 switch (status) {
1207 case SCTP_DISPOSITION_DISCARD:
1208 pr_debug("%s: ignored sctp protocol event - state:%d, "
1209 "event_type:%d, event_id:%d\n", __func__, state,
1210 event_type, subtype.chunk);
1211 break;
1212
1213 case SCTP_DISPOSITION_NOMEM:
1214 /* We ran out of memory, so we need to discard this
1215 * packet.
1216 */
1217 /* BUG--we should now recover some memory, probably by
1218 * reneging...
1219 */
1220 error = -ENOMEM;
1221 break;
1222
1223 case SCTP_DISPOSITION_DELETE_TCB:
1224 case SCTP_DISPOSITION_ABORT:
1225 /* This should now be a command. */
1226 *asoc = NULL;
1227 break;
1228
1229 case SCTP_DISPOSITION_CONSUME:
1230 /*
1231 * We should no longer have much work to do here as the
1232 * real work has been done as explicit commands above.
1233 */
1234 break;
1235
1236 case SCTP_DISPOSITION_VIOLATION:
1237 net_err_ratelimited("protocol violation state %d chunkid %d\n",
1238 state, subtype.chunk);
1239 break;
1240
1241 case SCTP_DISPOSITION_NOT_IMPL:
1242 pr_warn("unimplemented feature in state %d, event_type %d, event_id %d\n",
1243 state, event_type, subtype.chunk);
1244 break;
1245
1246 case SCTP_DISPOSITION_BUG:
1247 pr_err("bug in state %d, event_type %d, event_id %d\n",
1248 state, event_type, subtype.chunk);
1249 BUG();
1250 break;
1251
1252 default:
1253 pr_err("impossible disposition %d in state %d, event_type %d, event_id %d\n",
1254 status, state, event_type, subtype.chunk);
1255 BUG();
1256 break;
1257 }
1258
1259 bail:
1260 return error;
1261 }
1262
1263 /********************************************************************
1264 * 2nd Level Abstractions
1265 ********************************************************************/
1266
1267 /* This is the side-effect interpreter. */
1268 static int sctp_cmd_interpreter(enum sctp_event event_type,
1269 union sctp_subtype subtype,
1270 enum sctp_state state,
1271 struct sctp_endpoint *ep,
1272 struct sctp_association *asoc,
1273 void *event_arg,
1274 enum sctp_disposition status,
1275 struct sctp_cmd_seq *commands,
1276 gfp_t gfp)
1277 {
1278 struct sctp_sock *sp = sctp_sk(ep->base.sk);
1279 struct sctp_chunk *chunk = NULL, *new_obj;
1280 struct sctp_packet *packet;
1281 struct sctp_sackhdr sackh;
1282 struct timer_list *timer;
1283 struct sctp_transport *t;
1284 unsigned long timeout;
1285 struct sctp_cmd *cmd;
1286 int local_cork = 0;
1287 int error = 0;
1288 int force;
1289
1290 if (SCTP_EVENT_T_TIMEOUT != event_type)
1291 chunk = event_arg;
1292
1293 /* Note: This whole file is a huge candidate for rework.
1294 * For example, each command could either have its own handler, so
1295 * the loop would look like:
1296 * while (cmds)
1297 * cmd->handle(x, y, z)
1298 * --jgrimm
1299 */
1300 while (NULL != (cmd = sctp_next_cmd(commands))) {
1301 switch (cmd->verb) {
1302 case SCTP_CMD_NOP:
1303 /* Do nothing. */
1304 break;
1305
1306 case SCTP_CMD_NEW_ASOC:
1307 /* Register a new association. */
1308 if (local_cork) {
1309 sctp_outq_uncork(&asoc->outqueue, gfp);
1310 local_cork = 0;
1311 }
1312
1313 /* Register with the endpoint. */
1314 asoc = cmd->obj.asoc;
1315 BUG_ON(asoc->peer.primary_path == NULL);
1316 sctp_endpoint_add_asoc(ep, asoc);
1317 break;
1318
1319 case SCTP_CMD_UPDATE_ASSOC:
1320 sctp_cmd_assoc_update(commands, asoc, cmd->obj.asoc);
1321 break;
1322
1323 case SCTP_CMD_PURGE_OUTQUEUE:
1324 sctp_outq_teardown(&asoc->outqueue);
1325 break;
1326
1327 case SCTP_CMD_DELETE_TCB:
1328 if (local_cork) {
1329 sctp_outq_uncork(&asoc->outqueue, gfp);
1330 local_cork = 0;
1331 }
1332 /* Delete the current association. */
1333 sctp_cmd_delete_tcb(commands, asoc);
1334 asoc = NULL;
1335 break;
1336
1337 case SCTP_CMD_NEW_STATE:
1338 /* Enter a new state. */
1339 sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1340 break;
1341
1342 case SCTP_CMD_REPORT_TSN:
1343 /* Record the arrival of a TSN. */
1344 error = sctp_tsnmap_mark(&asoc->peer.tsn_map,
1345 cmd->obj.u32, NULL);
1346 break;
1347
1348 case SCTP_CMD_REPORT_FWDTSN:
1349 /* Move the Cumulattive TSN Ack ahead. */
1350 sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32);
1351
1352 /* purge the fragmentation queue */
1353 sctp_ulpq_reasm_flushtsn(&asoc->ulpq, cmd->obj.u32);
1354
1355 /* Abort any in progress partial delivery. */
1356 sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
1357 break;
1358
1359 case SCTP_CMD_PROCESS_FWDTSN:
1360 sctp_cmd_process_fwdtsn(&asoc->ulpq, cmd->obj.chunk);
1361 break;
1362
1363 case SCTP_CMD_GEN_SACK:
1364 /* Generate a Selective ACK.
1365 * The argument tells us whether to just count
1366 * the packet and MAYBE generate a SACK, or
1367 * force a SACK out.
1368 */
1369 force = cmd->obj.i32;
1370 error = sctp_gen_sack(asoc, force, commands);
1371 break;
1372
1373 case SCTP_CMD_PROCESS_SACK:
1374 /* Process an inbound SACK. */
1375 error = sctp_cmd_process_sack(commands, asoc,
1376 cmd->obj.chunk);
1377 break;
1378
1379 case SCTP_CMD_GEN_INIT_ACK:
1380 /* Generate an INIT ACK chunk. */
1381 new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1382 0);
1383 if (!new_obj)
1384 goto nomem;
1385
1386 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1387 SCTP_CHUNK(new_obj));
1388 break;
1389
1390 case SCTP_CMD_PEER_INIT:
1391 /* Process a unified INIT from the peer.
1392 * Note: Only used during INIT-ACK processing. If
1393 * there is an error just return to the outter
1394 * layer which will bail.
1395 */
1396 error = sctp_cmd_process_init(commands, asoc, chunk,
1397 cmd->obj.init, gfp);
1398 break;
1399
1400 case SCTP_CMD_GEN_COOKIE_ECHO:
1401 /* Generate a COOKIE ECHO chunk. */
1402 new_obj = sctp_make_cookie_echo(asoc, chunk);
1403 if (!new_obj) {
1404 if (cmd->obj.chunk)
1405 sctp_chunk_free(cmd->obj.chunk);
1406 goto nomem;
1407 }
1408 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1409 SCTP_CHUNK(new_obj));
1410
1411 /* If there is an ERROR chunk to be sent along with
1412 * the COOKIE_ECHO, send it, too.
1413 */
1414 if (cmd->obj.chunk)
1415 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1416 SCTP_CHUNK(cmd->obj.chunk));
1417
1418 if (new_obj->transport) {
1419 new_obj->transport->init_sent_count++;
1420 asoc->init_last_sent_to = new_obj->transport;
1421 }
1422
1423 /* FIXME - Eventually come up with a cleaner way to
1424 * enabling COOKIE-ECHO + DATA bundling during
1425 * multihoming stale cookie scenarios, the following
1426 * command plays with asoc->peer.retran_path to
1427 * avoid the problem of sending the COOKIE-ECHO and
1428 * DATA in different paths, which could result
1429 * in the association being ABORTed if the DATA chunk
1430 * is processed first by the server. Checking the
1431 * init error counter simply causes this command
1432 * to be executed only during failed attempts of
1433 * association establishment.
1434 */
1435 if ((asoc->peer.retran_path !=
1436 asoc->peer.primary_path) &&
1437 (asoc->init_err_counter > 0)) {
1438 sctp_add_cmd_sf(commands,
1439 SCTP_CMD_FORCE_PRIM_RETRAN,
1440 SCTP_NULL());
1441 }
1442
1443 break;
1444
1445 case SCTP_CMD_GEN_SHUTDOWN:
1446 /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1447 * Reset error counts.
1448 */
1449 asoc->overall_error_count = 0;
1450
1451 /* Generate a SHUTDOWN chunk. */
1452 new_obj = sctp_make_shutdown(asoc, chunk);
1453 if (!new_obj)
1454 goto nomem;
1455 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1456 SCTP_CHUNK(new_obj));
1457 break;
1458
1459 case SCTP_CMD_CHUNK_ULP:
1460 /* Send a chunk to the sockets layer. */
1461 pr_debug("%s: sm_sideff: chunk_up:%p, ulpq:%p\n",
1462 __func__, cmd->obj.chunk, &asoc->ulpq);
1463
1464 sctp_ulpq_tail_data(&asoc->ulpq, cmd->obj.chunk,
1465 GFP_ATOMIC);
1466 break;
1467
1468 case SCTP_CMD_EVENT_ULP:
1469 /* Send a notification to the sockets layer. */
1470 pr_debug("%s: sm_sideff: event_up:%p, ulpq:%p\n",
1471 __func__, cmd->obj.ulpevent, &asoc->ulpq);
1472
1473 sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ulpevent);
1474 break;
1475
1476 case SCTP_CMD_REPLY:
1477 /* If an caller has not already corked, do cork. */
1478 if (!asoc->outqueue.cork) {
1479 sctp_outq_cork(&asoc->outqueue);
1480 local_cork = 1;
1481 }
1482 /* Send a chunk to our peer. */
1483 sctp_outq_tail(&asoc->outqueue, cmd->obj.chunk, gfp);
1484 break;
1485
1486 case SCTP_CMD_SEND_PKT:
1487 /* Send a full packet to our peer. */
1488 packet = cmd->obj.packet;
1489 sctp_packet_transmit(packet, gfp);
1490 sctp_ootb_pkt_free(packet);
1491 break;
1492
1493 case SCTP_CMD_T1_RETRAN:
1494 /* Mark a transport for retransmission. */
1495 sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1496 SCTP_RTXR_T1_RTX);
1497 break;
1498
1499 case SCTP_CMD_RETRAN:
1500 /* Mark a transport for retransmission. */
1501 sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1502 SCTP_RTXR_T3_RTX);
1503 break;
1504
1505 case SCTP_CMD_ECN_CE:
1506 /* Do delayed CE processing. */
1507 sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1508 break;
1509
1510 case SCTP_CMD_ECN_ECNE:
1511 /* Do delayed ECNE processing. */
1512 new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1513 chunk);
1514 if (new_obj)
1515 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1516 SCTP_CHUNK(new_obj));
1517 break;
1518
1519 case SCTP_CMD_ECN_CWR:
1520 /* Do delayed CWR processing. */
1521 sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1522 break;
1523
1524 case SCTP_CMD_SETUP_T2:
1525 sctp_cmd_setup_t2(commands, asoc, cmd->obj.chunk);
1526 break;
1527
1528 case SCTP_CMD_TIMER_START_ONCE:
1529 timer = &asoc->timers[cmd->obj.to];
1530
1531 if (timer_pending(timer))
1532 break;
1533 /* fall through */
1534
1535 case SCTP_CMD_TIMER_START:
1536 timer = &asoc->timers[cmd->obj.to];
1537 timeout = asoc->timeouts[cmd->obj.to];
1538 BUG_ON(!timeout);
1539
1540 timer->expires = jiffies + timeout;
1541 sctp_association_hold(asoc);
1542 add_timer(timer);
1543 break;
1544
1545 case SCTP_CMD_TIMER_RESTART:
1546 timer = &asoc->timers[cmd->obj.to];
1547 timeout = asoc->timeouts[cmd->obj.to];
1548 if (!mod_timer(timer, jiffies + timeout))
1549 sctp_association_hold(asoc);
1550 break;
1551
1552 case SCTP_CMD_TIMER_STOP:
1553 timer = &asoc->timers[cmd->obj.to];
1554 if (del_timer(timer))
1555 sctp_association_put(asoc);
1556 break;
1557
1558 case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1559 chunk = cmd->obj.chunk;
1560 t = sctp_assoc_choose_alter_transport(asoc,
1561 asoc->init_last_sent_to);
1562 asoc->init_last_sent_to = t;
1563 chunk->transport = t;
1564 t->init_sent_count++;
1565 /* Set the new transport as primary */
1566 sctp_assoc_set_primary(asoc, t);
1567 break;
1568
1569 case SCTP_CMD_INIT_RESTART:
1570 /* Do the needed accounting and updates
1571 * associated with restarting an initialization
1572 * timer. Only multiply the timeout by two if
1573 * all transports have been tried at the current
1574 * timeout.
1575 */
1576 sctp_cmd_t1_timer_update(asoc,
1577 SCTP_EVENT_TIMEOUT_T1_INIT,
1578 "INIT");
1579
1580 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1581 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1582 break;
1583
1584 case SCTP_CMD_COOKIEECHO_RESTART:
1585 /* Do the needed accounting and updates
1586 * associated with restarting an initialization
1587 * timer. Only multiply the timeout by two if
1588 * all transports have been tried at the current
1589 * timeout.
1590 */
1591 sctp_cmd_t1_timer_update(asoc,
1592 SCTP_EVENT_TIMEOUT_T1_COOKIE,
1593 "COOKIE");
1594
1595 /* If we've sent any data bundled with
1596 * COOKIE-ECHO we need to resend.
1597 */
1598 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1599 transports) {
1600 sctp_retransmit_mark(&asoc->outqueue, t,
1601 SCTP_RTXR_T1_RTX);
1602 }
1603
1604 sctp_add_cmd_sf(commands,
1605 SCTP_CMD_TIMER_RESTART,
1606 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1607 break;
1608
1609 case SCTP_CMD_INIT_FAILED:
1610 sctp_cmd_init_failed(commands, asoc, cmd->obj.u32);
1611 break;
1612
1613 case SCTP_CMD_ASSOC_FAILED:
1614 sctp_cmd_assoc_failed(commands, asoc, event_type,
1615 subtype, chunk, cmd->obj.u32);
1616 break;
1617
1618 case SCTP_CMD_INIT_COUNTER_INC:
1619 asoc->init_err_counter++;
1620 break;
1621
1622 case SCTP_CMD_INIT_COUNTER_RESET:
1623 asoc->init_err_counter = 0;
1624 asoc->init_cycle = 0;
1625 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1626 transports) {
1627 t->init_sent_count = 0;
1628 }
1629 break;
1630
1631 case SCTP_CMD_REPORT_DUP:
1632 sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1633 cmd->obj.u32);
1634 break;
1635
1636 case SCTP_CMD_REPORT_BAD_TAG:
1637 pr_debug("%s: vtag mismatch!\n", __func__);
1638 break;
1639
1640 case SCTP_CMD_STRIKE:
1641 /* Mark one strike against a transport. */
1642 sctp_do_8_2_transport_strike(commands, asoc,
1643 cmd->obj.transport, 0);
1644 break;
1645
1646 case SCTP_CMD_TRANSPORT_IDLE:
1647 t = cmd->obj.transport;
1648 sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
1649 break;
1650
1651 case SCTP_CMD_TRANSPORT_HB_SENT:
1652 t = cmd->obj.transport;
1653 sctp_do_8_2_transport_strike(commands, asoc,
1654 t, 1);
1655 t->hb_sent = 1;
1656 break;
1657
1658 case SCTP_CMD_TRANSPORT_ON:
1659 t = cmd->obj.transport;
1660 sctp_cmd_transport_on(commands, asoc, t, chunk);
1661 break;
1662
1663 case SCTP_CMD_HB_TIMERS_START:
1664 sctp_cmd_hb_timers_start(commands, asoc);
1665 break;
1666
1667 case SCTP_CMD_HB_TIMER_UPDATE:
1668 t = cmd->obj.transport;
1669 sctp_transport_reset_hb_timer(t);
1670 break;
1671
1672 case SCTP_CMD_HB_TIMERS_STOP:
1673 sctp_cmd_hb_timers_stop(commands, asoc);
1674 break;
1675
1676 case SCTP_CMD_REPORT_ERROR:
1677 error = cmd->obj.error;
1678 break;
1679
1680 case SCTP_CMD_PROCESS_CTSN:
1681 /* Dummy up a SACK for processing. */
1682 sackh.cum_tsn_ack = cmd->obj.be32;
1683 sackh.a_rwnd = htonl(asoc->peer.rwnd +
1684 asoc->outqueue.outstanding_bytes);
1685 sackh.num_gap_ack_blocks = 0;
1686 sackh.num_dup_tsns = 0;
1687 chunk->subh.sack_hdr = &sackh;
1688 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1689 SCTP_CHUNK(chunk));
1690 break;
1691
1692 case SCTP_CMD_DISCARD_PACKET:
1693 /* We need to discard the whole packet.
1694 * Uncork the queue since there might be
1695 * responses pending
1696 */
1697 chunk->pdiscard = 1;
1698 if (asoc) {
1699 sctp_outq_uncork(&asoc->outqueue, gfp);
1700 local_cork = 0;
1701 }
1702 break;
1703
1704 case SCTP_CMD_RTO_PENDING:
1705 t = cmd->obj.transport;
1706 t->rto_pending = 1;
1707 break;
1708
1709 case SCTP_CMD_PART_DELIVER:
1710 sctp_ulpq_partial_delivery(&asoc->ulpq, GFP_ATOMIC);
1711 break;
1712
1713 case SCTP_CMD_RENEGE:
1714 sctp_ulpq_renege(&asoc->ulpq, cmd->obj.chunk,
1715 GFP_ATOMIC);
1716 break;
1717
1718 case SCTP_CMD_SETUP_T4:
1719 sctp_cmd_setup_t4(commands, asoc, cmd->obj.chunk);
1720 break;
1721
1722 case SCTP_CMD_PROCESS_OPERR:
1723 sctp_cmd_process_operr(commands, asoc, chunk);
1724 break;
1725 case SCTP_CMD_CLEAR_INIT_TAG:
1726 asoc->peer.i.init_tag = 0;
1727 break;
1728 case SCTP_CMD_DEL_NON_PRIMARY:
1729 sctp_cmd_del_non_primary(asoc);
1730 break;
1731 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1732 sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1733 break;
1734 case SCTP_CMD_FORCE_PRIM_RETRAN:
1735 t = asoc->peer.retran_path;
1736 asoc->peer.retran_path = asoc->peer.primary_path;
1737 sctp_outq_uncork(&asoc->outqueue, gfp);
1738 local_cork = 0;
1739 asoc->peer.retran_path = t;
1740 break;
1741 case SCTP_CMD_SET_SK_ERR:
1742 sctp_cmd_set_sk_err(asoc, cmd->obj.error);
1743 break;
1744 case SCTP_CMD_ASSOC_CHANGE:
1745 sctp_cmd_assoc_change(commands, asoc,
1746 cmd->obj.u8);
1747 break;
1748 case SCTP_CMD_ADAPTATION_IND:
1749 sctp_cmd_adaptation_ind(commands, asoc);
1750 break;
1751
1752 case SCTP_CMD_ASSOC_SHKEY:
1753 error = sctp_auth_asoc_init_active_key(asoc,
1754 GFP_ATOMIC);
1755 break;
1756 case SCTP_CMD_UPDATE_INITTAG:
1757 asoc->peer.i.init_tag = cmd->obj.u32;
1758 break;
1759 case SCTP_CMD_SEND_MSG:
1760 if (!asoc->outqueue.cork) {
1761 sctp_outq_cork(&asoc->outqueue);
1762 local_cork = 1;
1763 }
1764 sctp_cmd_send_msg(asoc, cmd->obj.msg, gfp);
1765 break;
1766 case SCTP_CMD_SEND_NEXT_ASCONF:
1767 sctp_cmd_send_asconf(asoc);
1768 break;
1769 case SCTP_CMD_PURGE_ASCONF_QUEUE:
1770 sctp_asconf_queue_teardown(asoc);
1771 break;
1772
1773 case SCTP_CMD_SET_ASOC:
1774 if (asoc && local_cork) {
1775 sctp_outq_uncork(&asoc->outqueue, gfp);
1776 local_cork = 0;
1777 }
1778 asoc = cmd->obj.asoc;
1779 break;
1780
1781 default:
1782 pr_warn("Impossible command: %u\n",
1783 cmd->verb);
1784 break;
1785 }
1786
1787 if (error)
1788 break;
1789 }
1790
1791 out:
1792 /* If this is in response to a received chunk, wait until
1793 * we are done with the packet to open the queue so that we don't
1794 * send multiple packets in response to a single request.
1795 */
1796 if (asoc && SCTP_EVENT_T_CHUNK == event_type && chunk) {
1797 if (chunk->end_of_packet || chunk->singleton)
1798 sctp_outq_uncork(&asoc->outqueue, gfp);
1799 } else if (local_cork)
1800 sctp_outq_uncork(&asoc->outqueue, gfp);
1801
1802 if (sp->data_ready_signalled)
1803 sp->data_ready_signalled = 0;
1804
1805 return error;
1806 nomem:
1807 error = -ENOMEM;
1808 goto out;
1809 }
1810
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