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Merge branch 'for-3.11' of git://linux-nfs.org/~bfields/linux
[linux-2.6.git] / net / sctp / sm_sideeffect.c
blob9da68852ee94fbf0a7dcb02b61ba90700d18f77c
1 /* SCTP kernel implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 *
6 * This file is part of the SCTP kernel implementation
7 *
8 * These functions work with the state functions in sctp_sm_statefuns.c
9 * to implement that state operations. These functions implement the
10 * steps which require modifying existing data structures.
11 *
12 * This SCTP implementation is free software;
13 * you can redistribute it and/or modify it under the terms of
14 * the GNU General Public License as published by
15 * the Free Software Foundation; either version 2, or (at your option)
16 * any later version.
17 *
18 * This SCTP implementation is distributed in the hope that it
19 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
20 * ************************
21 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
22 * See the GNU General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License
25 * along with GNU CC; see the file COPYING. If not, write to
26 * the Free Software Foundation, 59 Temple Place - Suite 330,
27 * Boston, MA 02111-1307, USA.
28 *
29 * Please send any bug reports or fixes you make to the
30 * email address(es):
31 * lksctp developers <lksctp-developers@lists.sourceforge.net>
32 *
33 * Or submit a bug report through the following website:
34 * http://www.sf.net/projects/lksctp
35 *
36 * Written or modified by:
37 * La Monte H.P. Yarroll <piggy@acm.org>
38 * Karl Knutson <karl@athena.chicago.il.us>
39 * Jon Grimm <jgrimm@austin.ibm.com>
40 * Hui Huang <hui.huang@nokia.com>
41 * Dajiang Zhang <dajiang.zhang@nokia.com>
42 * Daisy Chang <daisyc@us.ibm.com>
43 * Sridhar Samudrala <sri@us.ibm.com>
44 * Ardelle Fan <ardelle.fan@intel.com>
45 *
46 * Any bugs reported given to us we will try to fix... any fixes shared will
47 * be incorporated into the next SCTP release.
48 */
49
50 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
51
52 #include <linux/skbuff.h>
53 #include <linux/types.h>
54 #include <linux/socket.h>
55 #include <linux/ip.h>
56 #include <linux/gfp.h>
57 #include <net/sock.h>
58 #include <net/sctp/sctp.h>
59 #include <net/sctp/sm.h>
60
61 static int sctp_cmd_interpreter(sctp_event_t event_type,
62 sctp_subtype_t subtype,
63 sctp_state_t state,
64 struct sctp_endpoint *ep,
65 struct sctp_association *asoc,
66 void *event_arg,
67 sctp_disposition_t status,
68 sctp_cmd_seq_t *commands,
69 gfp_t gfp);
70 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
71 sctp_state_t state,
72 struct sctp_endpoint *ep,
73 struct sctp_association *asoc,
74 void *event_arg,
75 sctp_disposition_t status,
76 sctp_cmd_seq_t *commands,
77 gfp_t gfp);
78
79 static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
80 struct sctp_transport *t);
81 /********************************************************************
82 * Helper functions
83 ********************************************************************/
84
85 /* A helper function for delayed processing of INET ECN CE bit. */
86 static void sctp_do_ecn_ce_work(struct sctp_association *asoc,
87 __u32 lowest_tsn)
88 {
89 /* Save the TSN away for comparison when we receive CWR */
90
91 asoc->last_ecne_tsn = lowest_tsn;
92 asoc->need_ecne = 1;
93 }
94
95 /* Helper function for delayed processing of SCTP ECNE chunk. */
96 /* RFC 2960 Appendix A
97 *
98 * RFC 2481 details a specific bit for a sender to send in
99 * the header of its next outbound TCP segment to indicate to
100 * its peer that it has reduced its congestion window. This
101 * is termed the CWR bit. For SCTP the same indication is made
102 * by including the CWR chunk. This chunk contains one data
103 * element, i.e. the TSN number that was sent in the ECNE chunk.
104 * This element represents the lowest TSN number in the datagram
105 * that was originally marked with the CE bit.
106 */
107 static struct sctp_chunk *sctp_do_ecn_ecne_work(struct sctp_association *asoc,
108 __u32 lowest_tsn,
109 struct sctp_chunk *chunk)
110 {
111 struct sctp_chunk *repl;
112
113 /* Our previously transmitted packet ran into some congestion
114 * so we should take action by reducing cwnd and ssthresh
115 * and then ACK our peer that we we've done so by
116 * sending a CWR.
117 */
118
119 /* First, try to determine if we want to actually lower
120 * our cwnd variables. Only lower them if the ECNE looks more
121 * recent than the last response.
122 */
123 if (TSN_lt(asoc->last_cwr_tsn, lowest_tsn)) {
124 struct sctp_transport *transport;
125
126 /* Find which transport's congestion variables
127 * need to be adjusted.
128 */
129 transport = sctp_assoc_lookup_tsn(asoc, lowest_tsn);
130
131 /* Update the congestion variables. */
132 if (transport)
133 sctp_transport_lower_cwnd(transport,
134 SCTP_LOWER_CWND_ECNE);
135 asoc->last_cwr_tsn = lowest_tsn;
136 }
137
138 /* Always try to quiet the other end. In case of lost CWR,
139 * resend last_cwr_tsn.
140 */
141 repl = sctp_make_cwr(asoc, asoc->last_cwr_tsn, chunk);
142
143 /* If we run out of memory, it will look like a lost CWR. We'll
144 * get back in sync eventually.
145 */
146 return repl;
147 }
148
149 /* Helper function to do delayed processing of ECN CWR chunk. */
150 static void sctp_do_ecn_cwr_work(struct sctp_association *asoc,
151 __u32 lowest_tsn)
152 {
153 /* Turn off ECNE getting auto-prepended to every outgoing
154 * packet
155 */
156 asoc->need_ecne = 0;
157 }
158
159 /* Generate SACK if necessary. We call this at the end of a packet. */
160 static int sctp_gen_sack(struct sctp_association *asoc, int force,
161 sctp_cmd_seq_t *commands)
162 {
163 __u32 ctsn, max_tsn_seen;
164 struct sctp_chunk *sack;
165 struct sctp_transport *trans = asoc->peer.last_data_from;
166 int error = 0;
167
168 if (force ||
169 (!trans && (asoc->param_flags & SPP_SACKDELAY_DISABLE)) ||
170 (trans && (trans->param_flags & SPP_SACKDELAY_DISABLE)))
171 asoc->peer.sack_needed = 1;
172
173 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
174 max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
175
176 /* From 12.2 Parameters necessary per association (i.e. the TCB):
177 *
178 * Ack State : This flag indicates if the next received packet
179 * : is to be responded to with a SACK. ...
180 * : When DATA chunks are out of order, SACK's
181 * : are not delayed (see Section 6).
182 *
183 * [This is actually not mentioned in Section 6, but we
184 * implement it here anyway. --piggy]
185 */
186 if (max_tsn_seen != ctsn)
187 asoc->peer.sack_needed = 1;
188
189 /* From 6.2 Acknowledgement on Reception of DATA Chunks:
190 *
191 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically,
192 * an acknowledgement SHOULD be generated for at least every
193 * second packet (not every second DATA chunk) received, and
194 * SHOULD be generated within 200 ms of the arrival of any
195 * unacknowledged DATA chunk. ...
196 */
197 if (!asoc->peer.sack_needed) {
198 asoc->peer.sack_cnt++;
199
200 /* Set the SACK delay timeout based on the
201 * SACK delay for the last transport
202 * data was received from, or the default
203 * for the association.
204 */
205 if (trans) {
206 /* We will need a SACK for the next packet. */
207 if (asoc->peer.sack_cnt >= trans->sackfreq - 1)
208 asoc->peer.sack_needed = 1;
209
210 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
211 trans->sackdelay;
212 } else {
213 /* We will need a SACK for the next packet. */
214 if (asoc->peer.sack_cnt >= asoc->sackfreq - 1)
215 asoc->peer.sack_needed = 1;
216
217 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
218 asoc->sackdelay;
219 }
220
221 /* Restart the SACK timer. */
222 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
223 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
224 } else {
225 asoc->a_rwnd = asoc->rwnd;
226 sack = sctp_make_sack(asoc);
227 if (!sack)
228 goto nomem;
229
230 asoc->peer.sack_needed = 0;
231 asoc->peer.sack_cnt = 0;
232
233 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(sack));
234
235 /* Stop the SACK timer. */
236 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
237 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
238 }
239
240 return error;
241 nomem:
242 error = -ENOMEM;
243 return error;
244 }
245
246 /* When the T3-RTX timer expires, it calls this function to create the
247 * relevant state machine event.
248 */
249 void sctp_generate_t3_rtx_event(unsigned long peer)
250 {
251 int error;
252 struct sctp_transport *transport = (struct sctp_transport *) peer;
253 struct sctp_association *asoc = transport->asoc;
254 struct net *net = sock_net(asoc->base.sk);
255
256 /* Check whether a task is in the sock. */
257
258 sctp_bh_lock_sock(asoc->base.sk);
259 if (sock_owned_by_user(asoc->base.sk)) {
260 pr_debug("%s: sock is busy\n", __func__);
261
262 /* Try again later. */
263 if (!mod_timer(&transport->T3_rtx_timer, jiffies + (HZ/20)))
264 sctp_transport_hold(transport);
265 goto out_unlock;
266 }
267
268 /* Is this transport really dead and just waiting around for
269 * the timer to let go of the reference?
270 */
271 if (transport->dead)
272 goto out_unlock;
273
274 /* Run through the state machine. */
275 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
276 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX),
277 asoc->state,
278 asoc->ep, asoc,
279 transport, GFP_ATOMIC);
280
281 if (error)
282 asoc->base.sk->sk_err = -error;
283
284 out_unlock:
285 sctp_bh_unlock_sock(asoc->base.sk);
286 sctp_transport_put(transport);
287 }
288
289 /* This is a sa interface for producing timeout events. It works
290 * for timeouts which use the association as their parameter.
291 */
292 static void sctp_generate_timeout_event(struct sctp_association *asoc,
293 sctp_event_timeout_t timeout_type)
294 {
295 struct net *net = sock_net(asoc->base.sk);
296 int error = 0;
297
298 sctp_bh_lock_sock(asoc->base.sk);
299 if (sock_owned_by_user(asoc->base.sk)) {
300 pr_debug("%s: sock is busy: timer %d\n", __func__,
301 timeout_type);
302
303 /* Try again later. */
304 if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20)))
305 sctp_association_hold(asoc);
306 goto out_unlock;
307 }
308
309 /* Is this association really dead and just waiting around for
310 * the timer to let go of the reference?
311 */
312 if (asoc->base.dead)
313 goto out_unlock;
314
315 /* Run through the state machine. */
316 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
317 SCTP_ST_TIMEOUT(timeout_type),
318 asoc->state, asoc->ep, asoc,
319 (void *)timeout_type, GFP_ATOMIC);
320
321 if (error)
322 asoc->base.sk->sk_err = -error;
323
324 out_unlock:
325 sctp_bh_unlock_sock(asoc->base.sk);
326 sctp_association_put(asoc);
327 }
328
329 static void sctp_generate_t1_cookie_event(unsigned long data)
330 {
331 struct sctp_association *asoc = (struct sctp_association *) data;
332 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
333 }
334
335 static void sctp_generate_t1_init_event(unsigned long data)
336 {
337 struct sctp_association *asoc = (struct sctp_association *) data;
338 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
339 }
340
341 static void sctp_generate_t2_shutdown_event(unsigned long data)
342 {
343 struct sctp_association *asoc = (struct sctp_association *) data;
344 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
345 }
346
347 static void sctp_generate_t4_rto_event(unsigned long data)
348 {
349 struct sctp_association *asoc = (struct sctp_association *) data;
350 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
351 }
352
353 static void sctp_generate_t5_shutdown_guard_event(unsigned long data)
354 {
355 struct sctp_association *asoc = (struct sctp_association *)data;
356 sctp_generate_timeout_event(asoc,
357 SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);
358
359 } /* sctp_generate_t5_shutdown_guard_event() */
360
361 static void sctp_generate_autoclose_event(unsigned long data)
362 {
363 struct sctp_association *asoc = (struct sctp_association *) data;
364 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE);
365 }
366
367 /* Generate a heart beat event. If the sock is busy, reschedule. Make
368 * sure that the transport is still valid.
369 */
370 void sctp_generate_heartbeat_event(unsigned long data)
371 {
372 int error = 0;
373 struct sctp_transport *transport = (struct sctp_transport *) data;
374 struct sctp_association *asoc = transport->asoc;
375 struct net *net = sock_net(asoc->base.sk);
376
377 sctp_bh_lock_sock(asoc->base.sk);
378 if (sock_owned_by_user(asoc->base.sk)) {
379 pr_debug("%s: sock is busy\n", __func__);
380
381 /* Try again later. */
382 if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20)))
383 sctp_transport_hold(transport);
384 goto out_unlock;
385 }
386
387 /* Is this structure just waiting around for us to actually
388 * get destroyed?
389 */
390 if (transport->dead)
391 goto out_unlock;
392
393 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
394 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
395 asoc->state, asoc->ep, asoc,
396 transport, GFP_ATOMIC);
397
398 if (error)
399 asoc->base.sk->sk_err = -error;
400
401 out_unlock:
402 sctp_bh_unlock_sock(asoc->base.sk);
403 sctp_transport_put(transport);
404 }
405
406 /* Handle the timeout of the ICMP protocol unreachable timer. Trigger
407 * the correct state machine transition that will close the association.
408 */
409 void sctp_generate_proto_unreach_event(unsigned long data)
410 {
411 struct sctp_transport *transport = (struct sctp_transport *) data;
412 struct sctp_association *asoc = transport->asoc;
413 struct net *net = sock_net(asoc->base.sk);
414
415 sctp_bh_lock_sock(asoc->base.sk);
416 if (sock_owned_by_user(asoc->base.sk)) {
417 pr_debug("%s: sock is busy\n", __func__);
418
419 /* Try again later. */
420 if (!mod_timer(&transport->proto_unreach_timer,
421 jiffies + (HZ/20)))
422 sctp_association_hold(asoc);
423 goto out_unlock;
424 }
425
426 /* Is this structure just waiting around for us to actually
427 * get destroyed?
428 */
429 if (asoc->base.dead)
430 goto out_unlock;
431
432 sctp_do_sm(net, SCTP_EVENT_T_OTHER,
433 SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH),
434 asoc->state, asoc->ep, asoc, transport, GFP_ATOMIC);
435
436 out_unlock:
437 sctp_bh_unlock_sock(asoc->base.sk);
438 sctp_association_put(asoc);
439 }
440
441
442 /* Inject a SACK Timeout event into the state machine. */
443 static void sctp_generate_sack_event(unsigned long data)
444 {
445 struct sctp_association *asoc = (struct sctp_association *) data;
446 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
447 }
448
449 sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
450 NULL,
451 sctp_generate_t1_cookie_event,
452 sctp_generate_t1_init_event,
453 sctp_generate_t2_shutdown_event,
454 NULL,
455 sctp_generate_t4_rto_event,
456 sctp_generate_t5_shutdown_guard_event,
457 NULL,
458 sctp_generate_sack_event,
459 sctp_generate_autoclose_event,
460 };
461
462
463 /* RFC 2960 8.2 Path Failure Detection
464 *
465 * When its peer endpoint is multi-homed, an endpoint should keep a
466 * error counter for each of the destination transport addresses of the
467 * peer endpoint.
468 *
469 * Each time the T3-rtx timer expires on any address, or when a
470 * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
471 * the error counter of that destination address will be incremented.
472 * When the value in the error counter exceeds the protocol parameter
473 * 'Path.Max.Retrans' of that destination address, the endpoint should
474 * mark the destination transport address as inactive, and a
475 * notification SHOULD be sent to the upper layer.
476 *
477 */
478 static void sctp_do_8_2_transport_strike(sctp_cmd_seq_t *commands,
479 struct sctp_association *asoc,
480 struct sctp_transport *transport,
481 int is_hb)
482 {
483 /* The check for association's overall error counter exceeding the
484 * threshold is done in the state function.
485 */
486 /* We are here due to a timer expiration. If the timer was
487 * not a HEARTBEAT, then normal error tracking is done.
488 * If the timer was a heartbeat, we only increment error counts
489 * when we already have an outstanding HEARTBEAT that has not
490 * been acknowledged.
491 * Additionally, some tranport states inhibit error increments.
492 */
493 if (!is_hb) {
494 asoc->overall_error_count++;
495 if (transport->state != SCTP_INACTIVE)
496 transport->error_count++;
497 } else if (transport->hb_sent) {
498 if (transport->state != SCTP_UNCONFIRMED)
499 asoc->overall_error_count++;
500 if (transport->state != SCTP_INACTIVE)
501 transport->error_count++;
502 }
503
504 /* If the transport error count is greater than the pf_retrans
505 * threshold, and less than pathmaxrtx, then mark this transport
506 * as Partially Failed, ee SCTP Quick Failover Draft, secon 5.1,
507 * point 1
508 */
509 if ((transport->state != SCTP_PF) &&
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 BUG_ON(asoc->peer.primary_path == NULL);
870 sctp_unhash_established(asoc);
871 sctp_association_free(asoc);
872 }
873
874 /*
875 * ADDIP Section 4.1 ASCONF Chunk Procedures
876 * A4) Start a T-4 RTO timer, using the RTO value of the selected
877 * destination address (we use active path instead of primary path just
878 * because primary path may be inactive.
879 */
880 static void sctp_cmd_setup_t4(sctp_cmd_seq_t *cmds,
881 struct sctp_association *asoc,
882 struct sctp_chunk *chunk)
883 {
884 struct sctp_transport *t;
885
886 t = sctp_assoc_choose_alter_transport(asoc, chunk->transport);
887 asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
888 chunk->transport = t;
889 }
890
891 /* Process an incoming Operation Error Chunk. */
892 static void sctp_cmd_process_operr(sctp_cmd_seq_t *cmds,
893 struct sctp_association *asoc,
894 struct sctp_chunk *chunk)
895 {
896 struct sctp_errhdr *err_hdr;
897 struct sctp_ulpevent *ev;
898
899 while (chunk->chunk_end > chunk->skb->data) {
900 err_hdr = (struct sctp_errhdr *)(chunk->skb->data);
901
902 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
903 GFP_ATOMIC);
904 if (!ev)
905 return;
906
907 sctp_ulpq_tail_event(&asoc->ulpq, ev);
908
909 switch (err_hdr->cause) {
910 case SCTP_ERROR_UNKNOWN_CHUNK:
911 {
912 sctp_chunkhdr_t *unk_chunk_hdr;
913
914 unk_chunk_hdr = (sctp_chunkhdr_t *)err_hdr->variable;
915 switch (unk_chunk_hdr->type) {
916 /* ADDIP 4.1 A9) If the peer responds to an ASCONF with
917 * an ERROR chunk reporting that it did not recognized
918 * the ASCONF chunk type, the sender of the ASCONF MUST
919 * NOT send any further ASCONF chunks and MUST stop its
920 * T-4 timer.
921 */
922 case SCTP_CID_ASCONF:
923 if (asoc->peer.asconf_capable == 0)
924 break;
925
926 asoc->peer.asconf_capable = 0;
927 sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
928 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
929 break;
930 default:
931 break;
932 }
933 break;
934 }
935 default:
936 break;
937 }
938 }
939 }
940
941 /* Process variable FWDTSN chunk information. */
942 static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq,
943 struct sctp_chunk *chunk)
944 {
945 struct sctp_fwdtsn_skip *skip;
946 /* Walk through all the skipped SSNs */
947 sctp_walk_fwdtsn(skip, chunk) {
948 sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
949 }
950 }
951
952 /* Helper function to remove the association non-primary peer
953 * transports.
954 */
955 static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
956 {
957 struct sctp_transport *t;
958 struct list_head *pos;
959 struct list_head *temp;
960
961 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
962 t = list_entry(pos, struct sctp_transport, transports);
963 if (!sctp_cmp_addr_exact(&t->ipaddr,
964 &asoc->peer.primary_addr)) {
965 sctp_assoc_del_peer(asoc, &t->ipaddr);
966 }
967 }
968 }
969
970 /* Helper function to set sk_err on a 1-1 style socket. */
971 static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
972 {
973 struct sock *sk = asoc->base.sk;
974
975 if (!sctp_style(sk, UDP))
976 sk->sk_err = error;
977 }
978
979 /* Helper function to generate an association change event */
980 static void sctp_cmd_assoc_change(sctp_cmd_seq_t *commands,
981 struct sctp_association *asoc,
982 u8 state)
983 {
984 struct sctp_ulpevent *ev;
985
986 ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0,
987 asoc->c.sinit_num_ostreams,
988 asoc->c.sinit_max_instreams,
989 NULL, GFP_ATOMIC);
990 if (ev)
991 sctp_ulpq_tail_event(&asoc->ulpq, ev);
992 }
993
994 /* Helper function to generate an adaptation indication event */
995 static void sctp_cmd_adaptation_ind(sctp_cmd_seq_t *commands,
996 struct sctp_association *asoc)
997 {
998 struct sctp_ulpevent *ev;
999
1000 ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
1001
1002 if (ev)
1003 sctp_ulpq_tail_event(&asoc->ulpq, ev);
1004 }
1005
1006
1007 static void sctp_cmd_t1_timer_update(struct sctp_association *asoc,
1008 sctp_event_timeout_t timer,
1009 char *name)
1010 {
1011 struct sctp_transport *t;
1012
1013 t = asoc->init_last_sent_to;
1014 asoc->init_err_counter++;
1015
1016 if (t->init_sent_count > (asoc->init_cycle + 1)) {
1017 asoc->timeouts[timer] *= 2;
1018 if (asoc->timeouts[timer] > asoc->max_init_timeo) {
1019 asoc->timeouts[timer] = asoc->max_init_timeo;
1020 }
1021 asoc->init_cycle++;
1022
1023 pr_debug("%s: T1[%s] timeout adjustment init_err_counter:%d"
1024 " cycle:%d timeout:%ld\n", __func__, name,
1025 asoc->init_err_counter, asoc->init_cycle,
1026 asoc->timeouts[timer]);
1027 }
1028
1029 }
1030
1031 /* Send the whole message, chunk by chunk, to the outqueue.
1032 * This way the whole message is queued up and bundling if
1033 * encouraged for small fragments.
1034 */
1035 static int sctp_cmd_send_msg(struct sctp_association *asoc,
1036 struct sctp_datamsg *msg)
1037 {
1038 struct sctp_chunk *chunk;
1039 int error = 0;
1040
1041 list_for_each_entry(chunk, &msg->chunks, frag_list) {
1042 error = sctp_outq_tail(&asoc->outqueue, chunk);
1043 if (error)
1044 break;
1045 }
1046
1047 return error;
1048 }
1049
1050
1051 /* Sent the next ASCONF packet currently stored in the association.
1052 * This happens after the ASCONF_ACK was succeffully processed.
1053 */
1054 static void sctp_cmd_send_asconf(struct sctp_association *asoc)
1055 {
1056 struct net *net = sock_net(asoc->base.sk);
1057
1058 /* Send the next asconf chunk from the addip chunk
1059 * queue.
1060 */
1061 if (!list_empty(&asoc->addip_chunk_list)) {
1062 struct list_head *entry = asoc->addip_chunk_list.next;
1063 struct sctp_chunk *asconf = list_entry(entry,
1064 struct sctp_chunk, list);
1065 list_del_init(entry);
1066
1067 /* Hold the chunk until an ASCONF_ACK is received. */
1068 sctp_chunk_hold(asconf);
1069 if (sctp_primitive_ASCONF(net, asoc, asconf))
1070 sctp_chunk_free(asconf);
1071 else
1072 asoc->addip_last_asconf = asconf;
1073 }
1074 }
1075
1076
1077 /* These three macros allow us to pull the debugging code out of the
1078 * main flow of sctp_do_sm() to keep attention focused on the real
1079 * functionality there.
1080 */
1081 #define debug_pre_sfn() \
1082 pr_debug("%s[pre-fn]: ep:%p, %s, %s, asoc:%p[%s], %s\n", __func__, \
1083 ep, sctp_evttype_tbl[event_type], (*debug_fn)(subtype), \
1084 asoc, sctp_state_tbl[state], state_fn->name)
1085
1086 #define debug_post_sfn() \
1087 pr_debug("%s[post-fn]: asoc:%p, status:%s\n", __func__, asoc, \
1088 sctp_status_tbl[status])
1089
1090 #define debug_post_sfx() \
1091 pr_debug("%s[post-sfx]: error:%d, asoc:%p[%s]\n", __func__, error, \
1092 asoc, sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
1093 sctp_assoc2id(asoc))) ? asoc->state : SCTP_STATE_CLOSED])
1094
1095 /*
1096 * This is the master state machine processing function.
1097 *
1098 * If you want to understand all of lksctp, this is a
1099 * good place to start.
1100 */
1101 int sctp_do_sm(struct net *net, sctp_event_t event_type, sctp_subtype_t subtype,
1102 sctp_state_t state,
1103 struct sctp_endpoint *ep,
1104 struct sctp_association *asoc,
1105 void *event_arg,
1106 gfp_t gfp)
1107 {
1108 sctp_cmd_seq_t commands;
1109 const sctp_sm_table_entry_t *state_fn;
1110 sctp_disposition_t status;
1111 int error = 0;
1112 typedef const char *(printfn_t)(sctp_subtype_t);
1113 static printfn_t *table[] = {
1114 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
1115 };
1116 printfn_t *debug_fn __attribute__ ((unused)) = table[event_type];
1117
1118 /* Look up the state function, run it, and then process the
1119 * side effects. These three steps are the heart of lksctp.
1120 */
1121 state_fn = sctp_sm_lookup_event(net, event_type, state, subtype);
1122
1123 sctp_init_cmd_seq(&commands);
1124
1125 debug_pre_sfn();
1126 status = (*state_fn->fn)(net, ep, asoc, subtype, event_arg, &commands);
1127 debug_post_sfn();
1128
1129 error = sctp_side_effects(event_type, subtype, state,
1130 ep, asoc, event_arg, status,
1131 &commands, gfp);
1132 debug_post_sfx();
1133
1134 return error;
1135 }
1136
1137 /*****************************************************************
1138 * This the master state function side effect processing function.
1139 *****************************************************************/
1140 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
1141 sctp_state_t state,
1142 struct sctp_endpoint *ep,
1143 struct sctp_association *asoc,
1144 void *event_arg,
1145 sctp_disposition_t status,
1146 sctp_cmd_seq_t *commands,
1147 gfp_t gfp)
1148 {
1149 int error;
1150
1151 /* FIXME - Most of the dispositions left today would be categorized
1152 * as "exceptional" dispositions. For those dispositions, it
1153 * may not be proper to run through any of the commands at all.
1154 * For example, the command interpreter might be run only with
1155 * disposition SCTP_DISPOSITION_CONSUME.
1156 */
1157 if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
1158 ep, asoc,
1159 event_arg, status,
1160 commands, gfp)))
1161 goto bail;
1162
1163 switch (status) {
1164 case SCTP_DISPOSITION_DISCARD:
1165 pr_debug("%s: ignored sctp protocol event - state:%d, "
1166 "event_type:%d, event_id:%d\n", __func__, state,
1167 event_type, subtype.chunk);
1168 break;
1169
1170 case SCTP_DISPOSITION_NOMEM:
1171 /* We ran out of memory, so we need to discard this
1172 * packet.
1173 */
1174 /* BUG--we should now recover some memory, probably by
1175 * reneging...
1176 */
1177 error = -ENOMEM;
1178 break;
1179
1180 case SCTP_DISPOSITION_DELETE_TCB:
1181 /* This should now be a command. */
1182 break;
1183
1184 case SCTP_DISPOSITION_CONSUME:
1185 case SCTP_DISPOSITION_ABORT:
1186 /*
1187 * We should no longer have much work to do here as the
1188 * real work has been done as explicit commands above.
1189 */
1190 break;
1191
1192 case SCTP_DISPOSITION_VIOLATION:
1193 net_err_ratelimited("protocol violation state %d chunkid %d\n",
1194 state, subtype.chunk);
1195 break;
1196
1197 case SCTP_DISPOSITION_NOT_IMPL:
1198 pr_warn("unimplemented feature in state %d, event_type %d, event_id %d\n",
1199 state, event_type, subtype.chunk);
1200 break;
1201
1202 case SCTP_DISPOSITION_BUG:
1203 pr_err("bug in state %d, event_type %d, event_id %d\n",
1204 state, event_type, subtype.chunk);
1205 BUG();
1206 break;
1207
1208 default:
1209 pr_err("impossible disposition %d in state %d, event_type %d, event_id %d\n",
1210 status, state, event_type, subtype.chunk);
1211 BUG();
1212 break;
1213 }
1214
1215 bail:
1216 return error;
1217 }
1218
1219 /********************************************************************
1220 * 2nd Level Abstractions
1221 ********************************************************************/
1222
1223 /* This is the side-effect interpreter. */
1224 static int sctp_cmd_interpreter(sctp_event_t event_type,
1225 sctp_subtype_t subtype,
1226 sctp_state_t state,
1227 struct sctp_endpoint *ep,
1228 struct sctp_association *asoc,
1229 void *event_arg,
1230 sctp_disposition_t status,
1231 sctp_cmd_seq_t *commands,
1232 gfp_t gfp)
1233 {
1234 int error = 0;
1235 int force;
1236 sctp_cmd_t *cmd;
1237 struct sctp_chunk *new_obj;
1238 struct sctp_chunk *chunk = NULL;
1239 struct sctp_packet *packet;
1240 struct timer_list *timer;
1241 unsigned long timeout;
1242 struct sctp_transport *t;
1243 struct sctp_sackhdr sackh;
1244 int local_cork = 0;
1245
1246 if (SCTP_EVENT_T_TIMEOUT != event_type)
1247 chunk = event_arg;
1248
1249 /* Note: This whole file is a huge candidate for rework.
1250 * For example, each command could either have its own handler, so
1251 * the loop would look like:
1252 * while (cmds)
1253 * cmd->handle(x, y, z)
1254 * --jgrimm
1255 */
1256 while (NULL != (cmd = sctp_next_cmd(commands))) {
1257 switch (cmd->verb) {
1258 case SCTP_CMD_NOP:
1259 /* Do nothing. */
1260 break;
1261
1262 case SCTP_CMD_NEW_ASOC:
1263 /* Register a new association. */
1264 if (local_cork) {
1265 sctp_outq_uncork(&asoc->outqueue);
1266 local_cork = 0;
1267 }
1268
1269 /* Register with the endpoint. */
1270 asoc = cmd->obj.asoc;
1271 BUG_ON(asoc->peer.primary_path == NULL);
1272 sctp_endpoint_add_asoc(ep, asoc);
1273 sctp_hash_established(asoc);
1274 break;
1275
1276 case SCTP_CMD_UPDATE_ASSOC:
1277 sctp_assoc_update(asoc, cmd->obj.asoc);
1278 break;
1279
1280 case SCTP_CMD_PURGE_OUTQUEUE:
1281 sctp_outq_teardown(&asoc->outqueue);
1282 break;
1283
1284 case SCTP_CMD_DELETE_TCB:
1285 if (local_cork) {
1286 sctp_outq_uncork(&asoc->outqueue);
1287 local_cork = 0;
1288 }
1289 /* Delete the current association. */
1290 sctp_cmd_delete_tcb(commands, asoc);
1291 asoc = NULL;
1292 break;
1293
1294 case SCTP_CMD_NEW_STATE:
1295 /* Enter a new state. */
1296 sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1297 break;
1298
1299 case SCTP_CMD_REPORT_TSN:
1300 /* Record the arrival of a TSN. */
1301 error = sctp_tsnmap_mark(&asoc->peer.tsn_map,
1302 cmd->obj.u32, NULL);
1303 break;
1304
1305 case SCTP_CMD_REPORT_FWDTSN:
1306 /* Move the Cumulattive TSN Ack ahead. */
1307 sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32);
1308
1309 /* purge the fragmentation queue */
1310 sctp_ulpq_reasm_flushtsn(&asoc->ulpq, cmd->obj.u32);
1311
1312 /* Abort any in progress partial delivery. */
1313 sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
1314 break;
1315
1316 case SCTP_CMD_PROCESS_FWDTSN:
1317 sctp_cmd_process_fwdtsn(&asoc->ulpq, cmd->obj.chunk);
1318 break;
1319
1320 case SCTP_CMD_GEN_SACK:
1321 /* Generate a Selective ACK.
1322 * The argument tells us whether to just count
1323 * the packet and MAYBE generate a SACK, or
1324 * force a SACK out.
1325 */
1326 force = cmd->obj.i32;
1327 error = sctp_gen_sack(asoc, force, commands);
1328 break;
1329
1330 case SCTP_CMD_PROCESS_SACK:
1331 /* Process an inbound SACK. */
1332 error = sctp_cmd_process_sack(commands, asoc,
1333 cmd->obj.chunk);
1334 break;
1335
1336 case SCTP_CMD_GEN_INIT_ACK:
1337 /* Generate an INIT ACK chunk. */
1338 new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1339 0);
1340 if (!new_obj)
1341 goto nomem;
1342
1343 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1344 SCTP_CHUNK(new_obj));
1345 break;
1346
1347 case SCTP_CMD_PEER_INIT:
1348 /* Process a unified INIT from the peer.
1349 * Note: Only used during INIT-ACK processing. If
1350 * there is an error just return to the outter
1351 * layer which will bail.
1352 */
1353 error = sctp_cmd_process_init(commands, asoc, chunk,
1354 cmd->obj.init, gfp);
1355 break;
1356
1357 case SCTP_CMD_GEN_COOKIE_ECHO:
1358 /* Generate a COOKIE ECHO chunk. */
1359 new_obj = sctp_make_cookie_echo(asoc, chunk);
1360 if (!new_obj) {
1361 if (cmd->obj.chunk)
1362 sctp_chunk_free(cmd->obj.chunk);
1363 goto nomem;
1364 }
1365 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1366 SCTP_CHUNK(new_obj));
1367
1368 /* If there is an ERROR chunk to be sent along with
1369 * the COOKIE_ECHO, send it, too.
1370 */
1371 if (cmd->obj.chunk)
1372 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1373 SCTP_CHUNK(cmd->obj.chunk));
1374
1375 if (new_obj->transport) {
1376 new_obj->transport->init_sent_count++;
1377 asoc->init_last_sent_to = new_obj->transport;
1378 }
1379
1380 /* FIXME - Eventually come up with a cleaner way to
1381 * enabling COOKIE-ECHO + DATA bundling during
1382 * multihoming stale cookie scenarios, the following
1383 * command plays with asoc->peer.retran_path to
1384 * avoid the problem of sending the COOKIE-ECHO and
1385 * DATA in different paths, which could result
1386 * in the association being ABORTed if the DATA chunk
1387 * is processed first by the server. Checking the
1388 * init error counter simply causes this command
1389 * to be executed only during failed attempts of
1390 * association establishment.
1391 */
1392 if ((asoc->peer.retran_path !=
1393 asoc->peer.primary_path) &&
1394 (asoc->init_err_counter > 0)) {
1395 sctp_add_cmd_sf(commands,
1396 SCTP_CMD_FORCE_PRIM_RETRAN,
1397 SCTP_NULL());
1398 }
1399
1400 break;
1401
1402 case SCTP_CMD_GEN_SHUTDOWN:
1403 /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1404 * Reset error counts.
1405 */
1406 asoc->overall_error_count = 0;
1407
1408 /* Generate a SHUTDOWN chunk. */
1409 new_obj = sctp_make_shutdown(asoc, chunk);
1410 if (!new_obj)
1411 goto nomem;
1412 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1413 SCTP_CHUNK(new_obj));
1414 break;
1415
1416 case SCTP_CMD_CHUNK_ULP:
1417 /* Send a chunk to the sockets layer. */
1418 pr_debug("%s: sm_sideff: chunk_up:%p, ulpq:%p\n",
1419 __func__, cmd->obj.chunk, &asoc->ulpq);
1420
1421 sctp_ulpq_tail_data(&asoc->ulpq, cmd->obj.chunk,
1422 GFP_ATOMIC);
1423 break;
1424
1425 case SCTP_CMD_EVENT_ULP:
1426 /* Send a notification to the sockets layer. */
1427 pr_debug("%s: sm_sideff: event_up:%p, ulpq:%p\n",
1428 __func__, cmd->obj.ulpevent, &asoc->ulpq);
1429
1430 sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ulpevent);
1431 break;
1432
1433 case SCTP_CMD_REPLY:
1434 /* If an caller has not already corked, do cork. */
1435 if (!asoc->outqueue.cork) {
1436 sctp_outq_cork(&asoc->outqueue);
1437 local_cork = 1;
1438 }
1439 /* Send a chunk to our peer. */
1440 error = sctp_outq_tail(&asoc->outqueue, cmd->obj.chunk);
1441 break;
1442
1443 case SCTP_CMD_SEND_PKT:
1444 /* Send a full packet to our peer. */
1445 packet = cmd->obj.packet;
1446 sctp_packet_transmit(packet);
1447 sctp_ootb_pkt_free(packet);
1448 break;
1449
1450 case SCTP_CMD_T1_RETRAN:
1451 /* Mark a transport for retransmission. */
1452 sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1453 SCTP_RTXR_T1_RTX);
1454 break;
1455
1456 case SCTP_CMD_RETRAN:
1457 /* Mark a transport for retransmission. */
1458 sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1459 SCTP_RTXR_T3_RTX);
1460 break;
1461
1462 case SCTP_CMD_ECN_CE:
1463 /* Do delayed CE processing. */
1464 sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1465 break;
1466
1467 case SCTP_CMD_ECN_ECNE:
1468 /* Do delayed ECNE processing. */
1469 new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1470 chunk);
1471 if (new_obj)
1472 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1473 SCTP_CHUNK(new_obj));
1474 break;
1475
1476 case SCTP_CMD_ECN_CWR:
1477 /* Do delayed CWR processing. */
1478 sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1479 break;
1480
1481 case SCTP_CMD_SETUP_T2:
1482 sctp_cmd_setup_t2(commands, asoc, cmd->obj.chunk);
1483 break;
1484
1485 case SCTP_CMD_TIMER_START_ONCE:
1486 timer = &asoc->timers[cmd->obj.to];
1487
1488 if (timer_pending(timer))
1489 break;
1490 /* fall through */
1491
1492 case SCTP_CMD_TIMER_START:
1493 timer = &asoc->timers[cmd->obj.to];
1494 timeout = asoc->timeouts[cmd->obj.to];
1495 BUG_ON(!timeout);
1496
1497 timer->expires = jiffies + timeout;
1498 sctp_association_hold(asoc);
1499 add_timer(timer);
1500 break;
1501
1502 case SCTP_CMD_TIMER_RESTART:
1503 timer = &asoc->timers[cmd->obj.to];
1504 timeout = asoc->timeouts[cmd->obj.to];
1505 if (!mod_timer(timer, jiffies + timeout))
1506 sctp_association_hold(asoc);
1507 break;
1508
1509 case SCTP_CMD_TIMER_STOP:
1510 timer = &asoc->timers[cmd->obj.to];
1511 if (del_timer(timer))
1512 sctp_association_put(asoc);
1513 break;
1514
1515 case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1516 chunk = cmd->obj.chunk;
1517 t = sctp_assoc_choose_alter_transport(asoc,
1518 asoc->init_last_sent_to);
1519 asoc->init_last_sent_to = t;
1520 chunk->transport = t;
1521 t->init_sent_count++;
1522 /* Set the new transport as primary */
1523 sctp_assoc_set_primary(asoc, t);
1524 break;
1525
1526 case SCTP_CMD_INIT_RESTART:
1527 /* Do the needed accounting and updates
1528 * associated with restarting an initialization
1529 * timer. Only multiply the timeout by two if
1530 * all transports have been tried at the current
1531 * timeout.
1532 */
1533 sctp_cmd_t1_timer_update(asoc,
1534 SCTP_EVENT_TIMEOUT_T1_INIT,
1535 "INIT");
1536
1537 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1538 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1539 break;
1540
1541 case SCTP_CMD_COOKIEECHO_RESTART:
1542 /* Do the needed accounting and updates
1543 * associated with restarting an initialization
1544 * timer. Only multiply the timeout by two if
1545 * all transports have been tried at the current
1546 * timeout.
1547 */
1548 sctp_cmd_t1_timer_update(asoc,
1549 SCTP_EVENT_TIMEOUT_T1_COOKIE,
1550 "COOKIE");
1551
1552 /* If we've sent any data bundled with
1553 * COOKIE-ECHO we need to resend.
1554 */
1555 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1556 transports) {
1557 sctp_retransmit_mark(&asoc->outqueue, t,
1558 SCTP_RTXR_T1_RTX);
1559 }
1560
1561 sctp_add_cmd_sf(commands,
1562 SCTP_CMD_TIMER_RESTART,
1563 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1564 break;
1565
1566 case SCTP_CMD_INIT_FAILED:
1567 sctp_cmd_init_failed(commands, asoc, cmd->obj.err);
1568 break;
1569
1570 case SCTP_CMD_ASSOC_FAILED:
1571 sctp_cmd_assoc_failed(commands, asoc, event_type,
1572 subtype, chunk, cmd->obj.err);
1573 break;
1574
1575 case SCTP_CMD_INIT_COUNTER_INC:
1576 asoc->init_err_counter++;
1577 break;
1578
1579 case SCTP_CMD_INIT_COUNTER_RESET:
1580 asoc->init_err_counter = 0;
1581 asoc->init_cycle = 0;
1582 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1583 transports) {
1584 t->init_sent_count = 0;
1585 }
1586 break;
1587
1588 case SCTP_CMD_REPORT_DUP:
1589 sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1590 cmd->obj.u32);
1591 break;
1592
1593 case SCTP_CMD_REPORT_BAD_TAG:
1594 pr_debug("%s: vtag mismatch!\n", __func__);
1595 break;
1596
1597 case SCTP_CMD_STRIKE:
1598 /* Mark one strike against a transport. */
1599 sctp_do_8_2_transport_strike(commands, asoc,
1600 cmd->obj.transport, 0);
1601 break;
1602
1603 case SCTP_CMD_TRANSPORT_IDLE:
1604 t = cmd->obj.transport;
1605 sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
1606 break;
1607
1608 case SCTP_CMD_TRANSPORT_HB_SENT:
1609 t = cmd->obj.transport;
1610 sctp_do_8_2_transport_strike(commands, asoc,
1611 t, 1);
1612 t->hb_sent = 1;
1613 break;
1614
1615 case SCTP_CMD_TRANSPORT_ON:
1616 t = cmd->obj.transport;
1617 sctp_cmd_transport_on(commands, asoc, t, chunk);
1618 break;
1619
1620 case SCTP_CMD_HB_TIMERS_START:
1621 sctp_cmd_hb_timers_start(commands, asoc);
1622 break;
1623
1624 case SCTP_CMD_HB_TIMER_UPDATE:
1625 t = cmd->obj.transport;
1626 sctp_cmd_hb_timer_update(commands, t);
1627 break;
1628
1629 case SCTP_CMD_HB_TIMERS_STOP:
1630 sctp_cmd_hb_timers_stop(commands, asoc);
1631 break;
1632
1633 case SCTP_CMD_REPORT_ERROR:
1634 error = cmd->obj.error;
1635 break;
1636
1637 case SCTP_CMD_PROCESS_CTSN:
1638 /* Dummy up a SACK for processing. */
1639 sackh.cum_tsn_ack = cmd->obj.be32;
1640 sackh.a_rwnd = asoc->peer.rwnd +
1641 asoc->outqueue.outstanding_bytes;
1642 sackh.num_gap_ack_blocks = 0;
1643 sackh.num_dup_tsns = 0;
1644 chunk->subh.sack_hdr = &sackh;
1645 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1646 SCTP_CHUNK(chunk));
1647 break;
1648
1649 case SCTP_CMD_DISCARD_PACKET:
1650 /* We need to discard the whole packet.
1651 * Uncork the queue since there might be
1652 * responses pending
1653 */
1654 chunk->pdiscard = 1;
1655 if (asoc) {
1656 sctp_outq_uncork(&asoc->outqueue);
1657 local_cork = 0;
1658 }
1659 break;
1660
1661 case SCTP_CMD_RTO_PENDING:
1662 t = cmd->obj.transport;
1663 t->rto_pending = 1;
1664 break;
1665
1666 case SCTP_CMD_PART_DELIVER:
1667 sctp_ulpq_partial_delivery(&asoc->ulpq, GFP_ATOMIC);
1668 break;
1669
1670 case SCTP_CMD_RENEGE:
1671 sctp_ulpq_renege(&asoc->ulpq, cmd->obj.chunk,
1672 GFP_ATOMIC);
1673 break;
1674
1675 case SCTP_CMD_SETUP_T4:
1676 sctp_cmd_setup_t4(commands, asoc, cmd->obj.chunk);
1677 break;
1678
1679 case SCTP_CMD_PROCESS_OPERR:
1680 sctp_cmd_process_operr(commands, asoc, chunk);
1681 break;
1682 case SCTP_CMD_CLEAR_INIT_TAG:
1683 asoc->peer.i.init_tag = 0;
1684 break;
1685 case SCTP_CMD_DEL_NON_PRIMARY:
1686 sctp_cmd_del_non_primary(asoc);
1687 break;
1688 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1689 sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1690 break;
1691 case SCTP_CMD_FORCE_PRIM_RETRAN:
1692 t = asoc->peer.retran_path;
1693 asoc->peer.retran_path = asoc->peer.primary_path;
1694 error = sctp_outq_uncork(&asoc->outqueue);
1695 local_cork = 0;
1696 asoc->peer.retran_path = t;
1697 break;
1698 case SCTP_CMD_SET_SK_ERR:
1699 sctp_cmd_set_sk_err(asoc, cmd->obj.error);
1700 break;
1701 case SCTP_CMD_ASSOC_CHANGE:
1702 sctp_cmd_assoc_change(commands, asoc,
1703 cmd->obj.u8);
1704 break;
1705 case SCTP_CMD_ADAPTATION_IND:
1706 sctp_cmd_adaptation_ind(commands, asoc);
1707 break;
1708
1709 case SCTP_CMD_ASSOC_SHKEY:
1710 error = sctp_auth_asoc_init_active_key(asoc,
1711 GFP_ATOMIC);
1712 break;
1713 case SCTP_CMD_UPDATE_INITTAG:
1714 asoc->peer.i.init_tag = cmd->obj.u32;
1715 break;
1716 case SCTP_CMD_SEND_MSG:
1717 if (!asoc->outqueue.cork) {
1718 sctp_outq_cork(&asoc->outqueue);
1719 local_cork = 1;
1720 }
1721 error = sctp_cmd_send_msg(asoc, cmd->obj.msg);
1722 break;
1723 case SCTP_CMD_SEND_NEXT_ASCONF:
1724 sctp_cmd_send_asconf(asoc);
1725 break;
1726 case SCTP_CMD_PURGE_ASCONF_QUEUE:
1727 sctp_asconf_queue_teardown(asoc);
1728 break;
1729
1730 case SCTP_CMD_SET_ASOC:
1731 asoc = cmd->obj.asoc;
1732 break;
1733
1734 default:
1735 pr_warn("Impossible command: %u\n",
1736 cmd->verb);
1737 break;
1738 }
1739
1740 if (error)
1741 break;
1742 }
1743
1744 out:
1745 /* If this is in response to a received chunk, wait until
1746 * we are done with the packet to open the queue so that we don't
1747 * send multiple packets in response to a single request.
1748 */
1749 if (asoc && SCTP_EVENT_T_CHUNK == event_type && chunk) {
1750 if (chunk->end_of_packet || chunk->singleton)
1751 error = sctp_outq_uncork(&asoc->outqueue);
1752 } else if (local_cork)
1753 error = sctp_outq_uncork(&asoc->outqueue);
1754 return error;
1755 nomem:
1756 error = -ENOMEM;
1757 goto out;
1758 }
1759
Linus' kernel tree