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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, 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
61static 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);
70static 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/********************************************************************
80 * Helper functions
81 ********************************************************************/
82
83/* A helper function for delayed processing of INET ECN CE bit. */
84static void sctp_do_ecn_ce_work(struct sctp_association *asoc,
85 __u32 lowest_tsn)
86{
87 /* Save the TSN away for comparison when we receive CWR */
88
89 asoc->last_ecne_tsn = lowest_tsn;
90 asoc->need_ecne = 1;
91}
92
93/* Helper function for delayed processing of SCTP ECNE chunk. */
94/* RFC 2960 Appendix A
95 *
96 * RFC 2481 details a specific bit for a sender to send in
97 * the header of its next outbound TCP segment to indicate to
98 * its peer that it has reduced its congestion window. This
99 * is termed the CWR bit. For SCTP the same indication is made
100 * by including the CWR chunk. This chunk contains one data
101 * element, i.e. the TSN number that was sent in the ECNE chunk.
102 * This element represents the lowest TSN number in the datagram
103 * that was originally marked with the CE bit.
104 */
105static struct sctp_chunk *sctp_do_ecn_ecne_work(struct sctp_association *asoc,
106 __u32 lowest_tsn,
107 struct sctp_chunk *chunk)
108{
109 struct sctp_chunk *repl;
110
111 /* Our previously transmitted packet ran into some congestion
112 * so we should take action by reducing cwnd and ssthresh
113 * and then ACK our peer that we we've done so by
114 * sending a CWR.
115 */
116
117 /* First, try to determine if we want to actually lower
118 * our cwnd variables. Only lower them if the ECNE looks more
119 * recent than the last response.
120 */
121 if (TSN_lt(asoc->last_cwr_tsn, lowest_tsn)) {
122 struct sctp_transport *transport;
123
124 /* Find which transport's congestion variables
125 * need to be adjusted.
126 */
127 transport = sctp_assoc_lookup_tsn(asoc, lowest_tsn);
128
129 /* Update the congestion variables. */
130 if (transport)
131 sctp_transport_lower_cwnd(transport,
132 SCTP_LOWER_CWND_ECNE);
133 asoc->last_cwr_tsn = lowest_tsn;
134 }
135
136 /* Always try to quiet the other end. In case of lost CWR,
137 * resend last_cwr_tsn.
138 */
139 repl = sctp_make_cwr(asoc, asoc->last_cwr_tsn, chunk);
140
141 /* If we run out of memory, it will look like a lost CWR. We'll
142 * get back in sync eventually.
143 */
144 return repl;
145}
146
147/* Helper function to do delayed processing of ECN CWR chunk. */
148static void sctp_do_ecn_cwr_work(struct sctp_association *asoc,
149 __u32 lowest_tsn)
150{
151 /* Turn off ECNE getting auto-prepended to every outgoing
152 * packet
153 */
154 asoc->need_ecne = 0;
155}
156
157/* Generate SACK if necessary. We call this at the end of a packet. */
158static int sctp_gen_sack(struct sctp_association *asoc, int force,
159 sctp_cmd_seq_t *commands)
160{
161 __u32 ctsn, max_tsn_seen;
162 struct sctp_chunk *sack;
163 struct sctp_transport *trans = asoc->peer.last_data_from;
164 int error = 0;
165
166 if (force ||
167 (!trans && (asoc->param_flags & SPP_SACKDELAY_DISABLE)) ||
168 (trans && (trans->param_flags & SPP_SACKDELAY_DISABLE)))
169 asoc->peer.sack_needed = 1;
170
171 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
172 max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
173
174 /* From 12.2 Parameters necessary per association (i.e. the TCB):
175 *
176 * Ack State : This flag indicates if the next received packet
177 * : is to be responded to with a SACK. ...
178 * : When DATA chunks are out of order, SACK's
179 * : are not delayed (see Section 6).
180 *
181 * [This is actually not mentioned in Section 6, but we
182 * implement it here anyway. --piggy]
183 */
184 if (max_tsn_seen != ctsn)
185 asoc->peer.sack_needed = 1;
186
187 /* From 6.2 Acknowledgement on Reception of DATA Chunks:
188 *
189 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically,
190 * an acknowledgement SHOULD be generated for at least every
191 * second packet (not every second DATA chunk) received, and
192 * SHOULD be generated within 200 ms of the arrival of any
193 * unacknowledged DATA chunk. ...
194 */
195 if (!asoc->peer.sack_needed) {
196 asoc->peer.sack_cnt++;
197
198 /* Set the SACK delay timeout based on the
199 * SACK delay for the last transport
200 * data was received from, or the default
201 * for the association.
202 */
203 if (trans) {
204 /* We will need a SACK for the next packet. */
205 if (asoc->peer.sack_cnt >= trans->sackfreq - 1)
206 asoc->peer.sack_needed = 1;
207
208 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
209 trans->sackdelay;
210 } else {
211 /* We will need a SACK for the next packet. */
212 if (asoc->peer.sack_cnt >= asoc->sackfreq - 1)
213 asoc->peer.sack_needed = 1;
214
215 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
216 asoc->sackdelay;
217 }
218
219 /* Restart the SACK timer. */
220 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
221 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
222 } else {
223 asoc->a_rwnd = asoc->rwnd;
224 sack = sctp_make_sack(asoc);
225 if (!sack)
226 goto nomem;
227
228 asoc->peer.sack_needed = 0;
229 asoc->peer.sack_cnt = 0;
230
231 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(sack));
232
233 /* Stop the SACK timer. */
234 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
235 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
236 }
237
238 return error;
239nomem:
240 error = -ENOMEM;
241 return error;
242}
243
244/* When the T3-RTX timer expires, it calls this function to create the
245 * relevant state machine event.
246 */
247void sctp_generate_t3_rtx_event(unsigned long peer)
248{
249 int error;
250 struct sctp_transport *transport = (struct sctp_transport *) peer;
251 struct sctp_association *asoc = transport->asoc;
252
253 /* Check whether a task is in the sock. */
254
255 sctp_bh_lock_sock(asoc->base.sk);
256 if (sock_owned_by_user(asoc->base.sk)) {
257 SCTP_DEBUG_PRINTK("%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 /* Is this transport really dead and just waiting around for
266 * the timer to let go of the reference?
267 */
268 if (transport->dead)
269 goto out_unlock;
270
271 /* Run through the state machine. */
272 error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
273 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX),
274 asoc->state,
275 asoc->ep, asoc,
276 transport, GFP_ATOMIC);
277
278 if (error)
279 asoc->base.sk->sk_err = -error;
280
281out_unlock:
282 sctp_bh_unlock_sock(asoc->base.sk);
283 sctp_transport_put(transport);
284}
285
286/* This is a sa interface for producing timeout events. It works
287 * for timeouts which use the association as their parameter.
288 */
289static void sctp_generate_timeout_event(struct sctp_association *asoc,
290 sctp_event_timeout_t timeout_type)
291{
292 int error = 0;
293
294 sctp_bh_lock_sock(asoc->base.sk);
295 if (sock_owned_by_user(asoc->base.sk)) {
296 SCTP_DEBUG_PRINTK("%s:Sock is busy: timer %d\n",
297 __func__,
298 timeout_type);
299
300 /* Try again later. */
301 if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20)))
302 sctp_association_hold(asoc);
303 goto out_unlock;
304 }
305
306 /* Is this association really dead and just waiting around for
307 * the timer to let go of the reference?
308 */
309 if (asoc->base.dead)
310 goto out_unlock;
311
312 /* Run through the state machine. */
313 error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
314 SCTP_ST_TIMEOUT(timeout_type),
315 asoc->state, asoc->ep, asoc,
316 (void *)timeout_type, GFP_ATOMIC);
317
318 if (error)
319 asoc->base.sk->sk_err = -error;
320
321out_unlock:
322 sctp_bh_unlock_sock(asoc->base.sk);
323 sctp_association_put(asoc);
324}
325
326static void sctp_generate_t1_cookie_event(unsigned long data)
327{
328 struct sctp_association *asoc = (struct sctp_association *) data;
329 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
330}
331
332static void sctp_generate_t1_init_event(unsigned long data)
333{
334 struct sctp_association *asoc = (struct sctp_association *) data;
335 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
336}
337
338static void sctp_generate_t2_shutdown_event(unsigned long data)
339{
340 struct sctp_association *asoc = (struct sctp_association *) data;
341 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
342}
343
344static void sctp_generate_t4_rto_event(unsigned long data)
345{
346 struct sctp_association *asoc = (struct sctp_association *) data;
347 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
348}
349
350static void sctp_generate_t5_shutdown_guard_event(unsigned long data)
351{
352 struct sctp_association *asoc = (struct sctp_association *)data;
353 sctp_generate_timeout_event(asoc,
354 SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);
355
356} /* sctp_generate_t5_shutdown_guard_event() */
357
358static void sctp_generate_autoclose_event(unsigned long data)
359{
360 struct sctp_association *asoc = (struct sctp_association *) data;
361 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE);
362}
363
364/* Generate a heart beat event. If the sock is busy, reschedule. Make
365 * sure that the transport is still valid.
366 */
367void sctp_generate_heartbeat_event(unsigned long data)
368{
369 int error = 0;
370 struct sctp_transport *transport = (struct sctp_transport *) data;
371 struct sctp_association *asoc = transport->asoc;
372
373 sctp_bh_lock_sock(asoc->base.sk);
374 if (sock_owned_by_user(asoc->base.sk)) {
375 SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __func__);
376
377 /* Try again later. */
378 if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20)))
379 sctp_transport_hold(transport);
380 goto out_unlock;
381 }
382
383 /* Is this structure just waiting around for us to actually
384 * get destroyed?
385 */
386 if (transport->dead)
387 goto out_unlock;
388
389 error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
390 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
391 asoc->state, asoc->ep, asoc,
392 transport, GFP_ATOMIC);
393
394 if (error)
395 asoc->base.sk->sk_err = -error;
396
397out_unlock:
398 sctp_bh_unlock_sock(asoc->base.sk);
399 sctp_transport_put(transport);
400}
401
402/* Handle the timeout of the ICMP protocol unreachable timer. Trigger
403 * the correct state machine transition that will close the association.
404 */
405void sctp_generate_proto_unreach_event(unsigned long data)
406{
407 struct sctp_transport *transport = (struct sctp_transport *) data;
408 struct sctp_association *asoc = transport->asoc;
409
410 sctp_bh_lock_sock(asoc->base.sk);
411 if (sock_owned_by_user(asoc->base.sk)) {
412 SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __func__);
413
414 /* Try again later. */
415 if (!mod_timer(&transport->proto_unreach_timer,
416 jiffies + (HZ/20)))
417 sctp_association_hold(asoc);
418 goto out_unlock;
419 }
420
421 /* Is this structure just waiting around for us to actually
422 * get destroyed?
423 */
424 if (asoc->base.dead)
425 goto out_unlock;
426
427 sctp_do_sm(SCTP_EVENT_T_OTHER,
428 SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH),
429 asoc->state, asoc->ep, asoc, transport, GFP_ATOMIC);
430
431out_unlock:
432 sctp_bh_unlock_sock(asoc->base.sk);
433 sctp_association_put(asoc);
434}
435
436
437/* Inject a SACK Timeout event into the state machine. */
438static void sctp_generate_sack_event(unsigned long data)
439{
440 struct sctp_association *asoc = (struct sctp_association *) data;
441 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
442}
443
444sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
445 NULL,
446 sctp_generate_t1_cookie_event,
447 sctp_generate_t1_init_event,
448 sctp_generate_t2_shutdown_event,
449 NULL,
450 sctp_generate_t4_rto_event,
451 sctp_generate_t5_shutdown_guard_event,
452 NULL,
453 sctp_generate_sack_event,
454 sctp_generate_autoclose_event,
455};
456
457
458/* RFC 2960 8.2 Path Failure Detection
459 *
460 * When its peer endpoint is multi-homed, an endpoint should keep a
461 * error counter for each of the destination transport addresses of the
462 * peer endpoint.
463 *
464 * Each time the T3-rtx timer expires on any address, or when a
465 * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
466 * the error counter of that destination address will be incremented.
467 * When the value in the error counter exceeds the protocol parameter
468 * 'Path.Max.Retrans' of that destination address, the endpoint should
469 * mark the destination transport address as inactive, and a
470 * notification SHOULD be sent to the upper layer.
471 *
472 */
473static void sctp_do_8_2_transport_strike(struct sctp_association *asoc,
474 struct sctp_transport *transport,
475 int is_hb)
476{
477 /* The check for association's overall error counter exceeding the
478 * threshold is done in the state function.
479 */
480 /* We are here due to a timer expiration. If the timer was
481 * not a HEARTBEAT, then normal error tracking is done.
482 * If the timer was a heartbeat, we only increment error counts
483 * when we already have an outstanding HEARTBEAT that has not
484 * been acknowledged.
485 * Additionally, some tranport states inhibit error increments.
486 */
487 if (!is_hb) {
488 asoc->overall_error_count++;
489 if (transport->state != SCTP_INACTIVE)
490 transport->error_count++;
491 } else if (transport->hb_sent) {
492 if (transport->state != SCTP_UNCONFIRMED)
493 asoc->overall_error_count++;
494 if (transport->state != SCTP_INACTIVE)
495 transport->error_count++;
496 }
497
498 if (transport->state != SCTP_INACTIVE &&
499 (transport->error_count > transport->pathmaxrxt)) {
500 SCTP_DEBUG_PRINTK_IPADDR("transport_strike:association %p",
501 " transport IP: port:%d failed.\n",
502 asoc,
503 (&transport->ipaddr),
504 ntohs(transport->ipaddr.v4.sin_port));
505 sctp_assoc_control_transport(asoc, transport,
506 SCTP_TRANSPORT_DOWN,
507 SCTP_FAILED_THRESHOLD);
508 }
509
510 /* E2) For the destination address for which the timer
511 * expires, set RTO <- RTO * 2 ("back off the timer"). The
512 * maximum value discussed in rule C7 above (RTO.max) may be
513 * used to provide an upper bound to this doubling operation.
514 *
515 * Special Case: the first HB doesn't trigger exponential backoff.
516 * The first unacknowledged HB triggers it. We do this with a flag
517 * that indicates that we have an outstanding HB.
518 */
519 if (!is_hb || transport->hb_sent) {
520 transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
521 }
522}
523
524/* Worker routine to handle INIT command failure. */
525static void sctp_cmd_init_failed(sctp_cmd_seq_t *commands,
526 struct sctp_association *asoc,
527 unsigned error)
528{
529 struct sctp_ulpevent *event;
530
531 event = sctp_ulpevent_make_assoc_change(asoc,0, SCTP_CANT_STR_ASSOC,
532 (__u16)error, 0, 0, NULL,
533 GFP_ATOMIC);
534
535 if (event)
536 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
537 SCTP_ULPEVENT(event));
538
539 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
540 SCTP_STATE(SCTP_STATE_CLOSED));
541
542 /* SEND_FAILED sent later when cleaning up the association. */
543 asoc->outqueue.error = error;
544 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
545}
546
547/* Worker routine to handle SCTP_CMD_ASSOC_FAILED. */
548static void sctp_cmd_assoc_failed(sctp_cmd_seq_t *commands,
549 struct sctp_association *asoc,
550 sctp_event_t event_type,
551 sctp_subtype_t subtype,
552 struct sctp_chunk *chunk,
553 unsigned error)
554{
555 struct sctp_ulpevent *event;
556
557 /* Cancel any partial delivery in progress. */
558 sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
559
560 if (event_type == SCTP_EVENT_T_CHUNK && subtype.chunk == SCTP_CID_ABORT)
561 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
562 (__u16)error, 0, 0, chunk,
563 GFP_ATOMIC);
564 else
565 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
566 (__u16)error, 0, 0, NULL,
567 GFP_ATOMIC);
568 if (event)
569 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
570 SCTP_ULPEVENT(event));
571
572 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
573 SCTP_STATE(SCTP_STATE_CLOSED));
574
575 /* SEND_FAILED sent later when cleaning up the association. */
576 asoc->outqueue.error = error;
577 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
578}
579
580/* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
581 * inside the cookie. In reality, this is only used for INIT-ACK processing
582 * since all other cases use "temporary" associations and can do all
583 * their work in statefuns directly.
584 */
585static int sctp_cmd_process_init(sctp_cmd_seq_t *commands,
586 struct sctp_association *asoc,
587 struct sctp_chunk *chunk,
588 sctp_init_chunk_t *peer_init,
589 gfp_t gfp)
590{
591 int error;
592
593 /* We only process the init as a sideeffect in a single
594 * case. This is when we process the INIT-ACK. If we
595 * fail during INIT processing (due to malloc problems),
596 * just return the error and stop processing the stack.
597 */
598 if (!sctp_process_init(asoc, chunk, sctp_source(chunk), peer_init, gfp))
599 error = -ENOMEM;
600 else
601 error = 0;
602
603 return error;
604}
605
606/* Helper function to break out starting up of heartbeat timers. */
607static void sctp_cmd_hb_timers_start(sctp_cmd_seq_t *cmds,
608 struct sctp_association *asoc)
609{
610 struct sctp_transport *t;
611
612 /* Start a heartbeat timer for each transport on the association.
613 * hold a reference on the transport to make sure none of
614 * the needed data structures go away.
615 */
616 list_for_each_entry(t, &asoc->peer.transport_addr_list, transports) {
617
618 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
619 sctp_transport_hold(t);
620 }
621}
622
623static void sctp_cmd_hb_timers_stop(sctp_cmd_seq_t *cmds,
624 struct sctp_association *asoc)
625{
626 struct sctp_transport *t;
627
628 /* Stop all heartbeat timers. */
629
630 list_for_each_entry(t, &asoc->peer.transport_addr_list,
631 transports) {
632 if (del_timer(&t->hb_timer))
633 sctp_transport_put(t);
634 }
635}
636
637/* Helper function to stop any pending T3-RTX timers */
638static void sctp_cmd_t3_rtx_timers_stop(sctp_cmd_seq_t *cmds,
639 struct sctp_association *asoc)
640{
641 struct sctp_transport *t;
642
643 list_for_each_entry(t, &asoc->peer.transport_addr_list,
644 transports) {
645 if (timer_pending(&t->T3_rtx_timer) &&
646 del_timer(&t->T3_rtx_timer)) {
647 sctp_transport_put(t);
648 }
649 }
650}
651
652
653/* Helper function to update the heartbeat timer. */
654static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
655 struct sctp_transport *t)
656{
657 /* Update the heartbeat timer. */
658 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
659 sctp_transport_hold(t);
660}
661
662/* Helper function to handle the reception of an HEARTBEAT ACK. */
663static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds,
664 struct sctp_association *asoc,
665 struct sctp_transport *t,
666 struct sctp_chunk *chunk)
667{
668 sctp_sender_hb_info_t *hbinfo;
669
670 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
671 * HEARTBEAT should clear the error counter of the destination
672 * transport address to which the HEARTBEAT was sent.
673 */
674 t->error_count = 0;
675
676 /*
677 * Although RFC4960 specifies that the overall error count must
678 * be cleared when a HEARTBEAT ACK is received, we make an
679 * exception while in SHUTDOWN PENDING. If the peer keeps its
680 * window shut forever, we may never be able to transmit our
681 * outstanding data and rely on the retransmission limit be reached
682 * to shutdown the association.
683 */
684 if (t->asoc->state != SCTP_STATE_SHUTDOWN_PENDING)
685 t->asoc->overall_error_count = 0;
686
687 /* Clear the hb_sent flag to signal that we had a good
688 * acknowledgement.
689 */
690 t->hb_sent = 0;
691
692 /* Mark the destination transport address as active if it is not so
693 * marked.
694 */
695 if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED))
696 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
697 SCTP_HEARTBEAT_SUCCESS);
698
699 /* The receiver of the HEARTBEAT ACK should also perform an
700 * RTT measurement for that destination transport address
701 * using the time value carried in the HEARTBEAT ACK chunk.
702 * If the transport's rto_pending variable has been cleared,
703 * it was most likely due to a retransmit. However, we want
704 * to re-enable it to properly update the rto.
705 */
706 if (t->rto_pending == 0)
707 t->rto_pending = 1;
708
709 hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
710 sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
711
712 /* Update the heartbeat timer. */
713 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
714 sctp_transport_hold(t);
715}
716
717
718/* Helper function to process the process SACK command. */
719static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds,
720 struct sctp_association *asoc,
721 struct sctp_sackhdr *sackh)
722{
723 int err = 0;
724
725 if (sctp_outq_sack(&asoc->outqueue, sackh)) {
726 /* There are no more TSNs awaiting SACK. */
727 err = sctp_do_sm(SCTP_EVENT_T_OTHER,
728 SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
729 asoc->state, asoc->ep, asoc, NULL,
730 GFP_ATOMIC);
731 }
732
733 return err;
734}
735
736/* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
737 * the transport for a shutdown chunk.
738 */
739static void sctp_cmd_setup_t2(sctp_cmd_seq_t *cmds,
740 struct sctp_association *asoc,
741 struct sctp_chunk *chunk)
742{
743 struct sctp_transport *t;
744
745 if (chunk->transport)
746 t = chunk->transport;
747 else {
748 t = sctp_assoc_choose_alter_transport(asoc,
749 asoc->shutdown_last_sent_to);
750 chunk->transport = t;
751 }
752 asoc->shutdown_last_sent_to = t;
753 asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
754}
755
756/* Helper function to change the state of an association. */
757static void sctp_cmd_new_state(sctp_cmd_seq_t *cmds,
758 struct sctp_association *asoc,
759 sctp_state_t state)
760{
761 struct sock *sk = asoc->base.sk;
762
763 asoc->state = state;
764
765 SCTP_DEBUG_PRINTK("sctp_cmd_new_state: asoc %p[%s]\n",
766 asoc, sctp_state_tbl[state]);
767
768 if (sctp_style(sk, TCP)) {
769 /* Change the sk->sk_state of a TCP-style socket that has
770 * successfully completed a connect() call.
771 */
772 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
773 sk->sk_state = SCTP_SS_ESTABLISHED;
774
775 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
776 if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
777 sctp_sstate(sk, ESTABLISHED))
778 sk->sk_shutdown |= RCV_SHUTDOWN;
779 }
780
781 if (sctp_state(asoc, COOKIE_WAIT)) {
782 /* Reset init timeouts since they may have been
783 * increased due to timer expirations.
784 */
785 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
786 asoc->rto_initial;
787 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
788 asoc->rto_initial;
789 }
790
791 if (sctp_state(asoc, ESTABLISHED) ||
792 sctp_state(asoc, CLOSED) ||
793 sctp_state(asoc, SHUTDOWN_RECEIVED)) {
794 /* Wake up any processes waiting in the asoc's wait queue in
795 * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
796 */
797 if (waitqueue_active(&asoc->wait))
798 wake_up_interruptible(&asoc->wait);
799
800 /* Wake up any processes waiting in the sk's sleep queue of
801 * a TCP-style or UDP-style peeled-off socket in
802 * sctp_wait_for_accept() or sctp_wait_for_packet().
803 * For a UDP-style socket, the waiters are woken up by the
804 * notifications.
805 */
806 if (!sctp_style(sk, UDP))
807 sk->sk_state_change(sk);
808 }
809}
810
811/* Helper function to delete an association. */
812static void sctp_cmd_delete_tcb(sctp_cmd_seq_t *cmds,
813 struct sctp_association *asoc)
814{
815 struct sock *sk = asoc->base.sk;
816
817 /* If it is a non-temporary association belonging to a TCP-style
818 * listening socket that is not closed, do not free it so that accept()
819 * can pick it up later.
820 */
821 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
822 (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
823 return;
824
825 sctp_unhash_established(asoc);
826 sctp_association_free(asoc);
827}
828
829/*
830 * ADDIP Section 4.1 ASCONF Chunk Procedures
831 * A4) Start a T-4 RTO timer, using the RTO value of the selected
832 * destination address (we use active path instead of primary path just
833 * because primary path may be inactive.
834 */
835static void sctp_cmd_setup_t4(sctp_cmd_seq_t *cmds,
836 struct sctp_association *asoc,
837 struct sctp_chunk *chunk)
838{
839 struct sctp_transport *t;
840
841 t = sctp_assoc_choose_alter_transport(asoc, chunk->transport);
842 asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
843 chunk->transport = t;
844}
845
846/* Process an incoming Operation Error Chunk. */
847static void sctp_cmd_process_operr(sctp_cmd_seq_t *cmds,
848 struct sctp_association *asoc,
849 struct sctp_chunk *chunk)
850{
851 struct sctp_errhdr *err_hdr;
852 struct sctp_ulpevent *ev;
853
854 while (chunk->chunk_end > chunk->skb->data) {
855 err_hdr = (struct sctp_errhdr *)(chunk->skb->data);
856
857 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
858 GFP_ATOMIC);
859 if (!ev)
860 return;
861
862 sctp_ulpq_tail_event(&asoc->ulpq, ev);
863
864 switch (err_hdr->cause) {
865 case SCTP_ERROR_UNKNOWN_CHUNK:
866 {
867 sctp_chunkhdr_t *unk_chunk_hdr;
868
869 unk_chunk_hdr = (sctp_chunkhdr_t *)err_hdr->variable;
870 switch (unk_chunk_hdr->type) {
871 /* ADDIP 4.1 A9) If the peer responds to an ASCONF with
872 * an ERROR chunk reporting that it did not recognized
873 * the ASCONF chunk type, the sender of the ASCONF MUST
874 * NOT send any further ASCONF chunks and MUST stop its
875 * T-4 timer.
876 */
877 case SCTP_CID_ASCONF:
878 if (asoc->peer.asconf_capable == 0)
879 break;
880
881 asoc->peer.asconf_capable = 0;
882 sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
883 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
884 break;
885 default:
886 break;
887 }
888 break;
889 }
890 default:
891 break;
892 }
893 }
894}
895
896/* Process variable FWDTSN chunk information. */
897static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq,
898 struct sctp_chunk *chunk)
899{
900 struct sctp_fwdtsn_skip *skip;
901 /* Walk through all the skipped SSNs */
902 sctp_walk_fwdtsn(skip, chunk) {
903 sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
904 }
905}
906
907/* Helper function to remove the association non-primary peer
908 * transports.
909 */
910static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
911{
912 struct sctp_transport *t;
913 struct list_head *pos;
914 struct list_head *temp;
915
916 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
917 t = list_entry(pos, struct sctp_transport, transports);
918 if (!sctp_cmp_addr_exact(&t->ipaddr,
919 &asoc->peer.primary_addr)) {
920 sctp_assoc_del_peer(asoc, &t->ipaddr);
921 }
922 }
923}
924
925/* Helper function to set sk_err on a 1-1 style socket. */
926static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
927{
928 struct sock *sk = asoc->base.sk;
929
930 if (!sctp_style(sk, UDP))
931 sk->sk_err = error;
932}
933
934/* Helper function to generate an association change event */
935static void sctp_cmd_assoc_change(sctp_cmd_seq_t *commands,
936 struct sctp_association *asoc,
937 u8 state)
938{
939 struct sctp_ulpevent *ev;
940
941 ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0,
942 asoc->c.sinit_num_ostreams,
943 asoc->c.sinit_max_instreams,
944 NULL, GFP_ATOMIC);
945 if (ev)
946 sctp_ulpq_tail_event(&asoc->ulpq, ev);
947}
948
949/* Helper function to generate an adaptation indication event */
950static void sctp_cmd_adaptation_ind(sctp_cmd_seq_t *commands,
951 struct sctp_association *asoc)
952{
953 struct sctp_ulpevent *ev;
954
955 ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
956
957 if (ev)
958 sctp_ulpq_tail_event(&asoc->ulpq, ev);
959}
960
961
962static void sctp_cmd_t1_timer_update(struct sctp_association *asoc,
963 sctp_event_timeout_t timer,
964 char *name)
965{
966 struct sctp_transport *t;
967
968 t = asoc->init_last_sent_to;
969 asoc->init_err_counter++;
970
971 if (t->init_sent_count > (asoc->init_cycle + 1)) {
972 asoc->timeouts[timer] *= 2;
973 if (asoc->timeouts[timer] > asoc->max_init_timeo) {
974 asoc->timeouts[timer] = asoc->max_init_timeo;
975 }
976 asoc->init_cycle++;
977 SCTP_DEBUG_PRINTK(
978 "T1 %s Timeout adjustment"
979 " init_err_counter: %d"
980 " cycle: %d"
981 " timeout: %ld\n",
982 name,
983 asoc->init_err_counter,
984 asoc->init_cycle,
985 asoc->timeouts[timer]);
986 }
987
988}
989
990/* Send the whole message, chunk by chunk, to the outqueue.
991 * This way the whole message is queued up and bundling if
992 * encouraged for small fragments.
993 */
994static int sctp_cmd_send_msg(struct sctp_association *asoc,
995 struct sctp_datamsg *msg)
996{
997 struct sctp_chunk *chunk;
998 int error = 0;
999
1000 list_for_each_entry(chunk, &msg->chunks, frag_list) {
1001 error = sctp_outq_tail(&asoc->outqueue, chunk);
1002 if (error)
1003 break;
1004 }
1005
1006 return error;
1007}
1008
1009
1010/* Sent the next ASCONF packet currently stored in the association.
1011 * This happens after the ASCONF_ACK was succeffully processed.
1012 */
1013static void sctp_cmd_send_asconf(struct sctp_association *asoc)
1014{
1015 /* Send the next asconf chunk from the addip chunk
1016 * queue.
1017 */
1018 if (!list_empty(&asoc->addip_chunk_list)) {
1019 struct list_head *entry = asoc->addip_chunk_list.next;
1020 struct sctp_chunk *asconf = list_entry(entry,
1021 struct sctp_chunk, list);
1022 list_del_init(entry);
1023
1024 /* Hold the chunk until an ASCONF_ACK is received. */
1025 sctp_chunk_hold(asconf);
1026 if (sctp_primitive_ASCONF(asoc, asconf))
1027 sctp_chunk_free(asconf);
1028 else
1029 asoc->addip_last_asconf = asconf;
1030 }
1031}
1032
1033
1034/* These three macros allow us to pull the debugging code out of the
1035 * main flow of sctp_do_sm() to keep attention focused on the real
1036 * functionality there.
1037 */
1038#define DEBUG_PRE \
1039 SCTP_DEBUG_PRINTK("sctp_do_sm prefn: " \
1040 "ep %p, %s, %s, asoc %p[%s], %s\n", \
1041 ep, sctp_evttype_tbl[event_type], \
1042 (*debug_fn)(subtype), asoc, \
1043 sctp_state_tbl[state], state_fn->name)
1044
1045#define DEBUG_POST \
1046 SCTP_DEBUG_PRINTK("sctp_do_sm postfn: " \
1047 "asoc %p, status: %s\n", \
1048 asoc, sctp_status_tbl[status])
1049
1050#define DEBUG_POST_SFX \
1051 SCTP_DEBUG_PRINTK("sctp_do_sm post sfx: error %d, asoc %p[%s]\n", \
1052 error, asoc, \
1053 sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
1054 sctp_assoc2id(asoc)))?asoc->state:SCTP_STATE_CLOSED])
1055
1056/*
1057 * This is the master state machine processing function.
1058 *
1059 * If you want to understand all of lksctp, this is a
1060 * good place to start.
1061 */
1062int sctp_do_sm(sctp_event_t event_type, sctp_subtype_t subtype,
1063 sctp_state_t state,
1064 struct sctp_endpoint *ep,
1065 struct sctp_association *asoc,
1066 void *event_arg,
1067 gfp_t gfp)
1068{
1069 sctp_cmd_seq_t commands;
1070 const sctp_sm_table_entry_t *state_fn;
1071 sctp_disposition_t status;
1072 int error = 0;
1073 typedef const char *(printfn_t)(sctp_subtype_t);
1074
1075 static printfn_t *table[] = {
1076 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
1077 };
1078 printfn_t *debug_fn __attribute__ ((unused)) = table[event_type];
1079
1080 /* Look up the state function, run it, and then process the
1081 * side effects. These three steps are the heart of lksctp.
1082 */
1083 state_fn = sctp_sm_lookup_event(event_type, state, subtype);
1084
1085 sctp_init_cmd_seq(&commands);
1086
1087 DEBUG_PRE;
1088 status = (*state_fn->fn)(ep, asoc, subtype, event_arg, &commands);
1089 DEBUG_POST;
1090
1091 error = sctp_side_effects(event_type, subtype, state,
1092 ep, asoc, event_arg, status,
1093 &commands, gfp);
1094 DEBUG_POST_SFX;
1095
1096 return error;
1097}
1098
1099#undef DEBUG_PRE
1100#undef DEBUG_POST
1101
1102/*****************************************************************
1103 * This the master state function side effect processing function.
1104 *****************************************************************/
1105static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
1106 sctp_state_t state,
1107 struct sctp_endpoint *ep,
1108 struct sctp_association *asoc,
1109 void *event_arg,
1110 sctp_disposition_t status,
1111 sctp_cmd_seq_t *commands,
1112 gfp_t gfp)
1113{
1114 int error;
1115
1116 /* FIXME - Most of the dispositions left today would be categorized
1117 * as "exceptional" dispositions. For those dispositions, it
1118 * may not be proper to run through any of the commands at all.
1119 * For example, the command interpreter might be run only with
1120 * disposition SCTP_DISPOSITION_CONSUME.
1121 */
1122 if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
1123 ep, asoc,
1124 event_arg, status,
1125 commands, gfp)))
1126 goto bail;
1127
1128 switch (status) {
1129 case SCTP_DISPOSITION_DISCARD:
1130 SCTP_DEBUG_PRINTK("Ignored sctp protocol event - state %d, "
1131 "event_type %d, event_id %d\n",
1132 state, event_type, subtype.chunk);
1133 break;
1134
1135 case SCTP_DISPOSITION_NOMEM:
1136 /* We ran out of memory, so we need to discard this
1137 * packet.
1138 */
1139 /* BUG--we should now recover some memory, probably by
1140 * reneging...
1141 */
1142 error = -ENOMEM;
1143 break;
1144
1145 case SCTP_DISPOSITION_DELETE_TCB:
1146 /* This should now be a command. */
1147 break;
1148
1149 case SCTP_DISPOSITION_CONSUME:
1150 case SCTP_DISPOSITION_ABORT:
1151 /*
1152 * We should no longer have much work to do here as the
1153 * real work has been done as explicit commands above.
1154 */
1155 break;
1156
1157 case SCTP_DISPOSITION_VIOLATION:
1158 if (net_ratelimit())
1159 pr_err("protocol violation state %d chunkid %d\n",
1160 state, subtype.chunk);
1161 break;
1162
1163 case SCTP_DISPOSITION_NOT_IMPL:
1164 pr_warn("unimplemented feature in state %d, event_type %d, event_id %d\n",
1165 state, event_type, subtype.chunk);
1166 break;
1167
1168 case SCTP_DISPOSITION_BUG:
1169 pr_err("bug in state %d, event_type %d, event_id %d\n",
1170 state, event_type, subtype.chunk);
1171 BUG();
1172 break;
1173
1174 default:
1175 pr_err("impossible disposition %d in state %d, event_type %d, event_id %d\n",
1176 status, state, event_type, subtype.chunk);
1177 BUG();
1178 break;
1179 }
1180
1181bail:
1182 return error;
1183}
1184
1185/********************************************************************
1186 * 2nd Level Abstractions
1187 ********************************************************************/
1188
1189/* This is the side-effect interpreter. */
1190static int sctp_cmd_interpreter(sctp_event_t event_type,
1191 sctp_subtype_t subtype,
1192 sctp_state_t state,
1193 struct sctp_endpoint *ep,
1194 struct sctp_association *asoc,
1195 void *event_arg,
1196 sctp_disposition_t status,
1197 sctp_cmd_seq_t *commands,
1198 gfp_t gfp)
1199{
1200 int error = 0;
1201 int force;
1202 sctp_cmd_t *cmd;
1203 struct sctp_chunk *new_obj;
1204 struct sctp_chunk *chunk = NULL;
1205 struct sctp_packet *packet;
1206 struct timer_list *timer;
1207 unsigned long timeout;
1208 struct sctp_transport *t;
1209 struct sctp_sackhdr sackh;
1210 int local_cork = 0;
1211
1212 if (SCTP_EVENT_T_TIMEOUT != event_type)
1213 chunk = event_arg;
1214
1215 /* Note: This whole file is a huge candidate for rework.
1216 * For example, each command could either have its own handler, so
1217 * the loop would look like:
1218 * while (cmds)
1219 * cmd->handle(x, y, z)
1220 * --jgrimm
1221 */
1222 while (NULL != (cmd = sctp_next_cmd(commands))) {
1223 switch (cmd->verb) {
1224 case SCTP_CMD_NOP:
1225 /* Do nothing. */
1226 break;
1227
1228 case SCTP_CMD_NEW_ASOC:
1229 /* Register a new association. */
1230 if (local_cork) {
1231 sctp_outq_uncork(&asoc->outqueue);
1232 local_cork = 0;
1233 }
1234 asoc = cmd->obj.ptr;
1235 /* Register with the endpoint. */
1236 sctp_endpoint_add_asoc(ep, asoc);
1237 sctp_hash_established(asoc);
1238 break;
1239
1240 case SCTP_CMD_UPDATE_ASSOC:
1241 sctp_assoc_update(asoc, cmd->obj.ptr);
1242 break;
1243
1244 case SCTP_CMD_PURGE_OUTQUEUE:
1245 sctp_outq_teardown(&asoc->outqueue);
1246 break;
1247
1248 case SCTP_CMD_DELETE_TCB:
1249 if (local_cork) {
1250 sctp_outq_uncork(&asoc->outqueue);
1251 local_cork = 0;
1252 }
1253 /* Delete the current association. */
1254 sctp_cmd_delete_tcb(commands, asoc);
1255 asoc = NULL;
1256 break;
1257
1258 case SCTP_CMD_NEW_STATE:
1259 /* Enter a new state. */
1260 sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1261 break;
1262
1263 case SCTP_CMD_REPORT_TSN:
1264 /* Record the arrival of a TSN. */
1265 error = sctp_tsnmap_mark(&asoc->peer.tsn_map,
1266 cmd->obj.u32);
1267 break;
1268
1269 case SCTP_CMD_REPORT_FWDTSN:
1270 /* Move the Cumulattive TSN Ack ahead. */
1271 sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32);
1272
1273 /* purge the fragmentation queue */
1274 sctp_ulpq_reasm_flushtsn(&asoc->ulpq, cmd->obj.u32);
1275
1276 /* Abort any in progress partial delivery. */
1277 sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
1278 break;
1279
1280 case SCTP_CMD_PROCESS_FWDTSN:
1281 sctp_cmd_process_fwdtsn(&asoc->ulpq, cmd->obj.ptr);
1282 break;
1283
1284 case SCTP_CMD_GEN_SACK:
1285 /* Generate a Selective ACK.
1286 * The argument tells us whether to just count
1287 * the packet and MAYBE generate a SACK, or
1288 * force a SACK out.
1289 */
1290 force = cmd->obj.i32;
1291 error = sctp_gen_sack(asoc, force, commands);
1292 break;
1293
1294 case SCTP_CMD_PROCESS_SACK:
1295 /* Process an inbound SACK. */
1296 error = sctp_cmd_process_sack(commands, asoc,
1297 cmd->obj.ptr);
1298 break;
1299
1300 case SCTP_CMD_GEN_INIT_ACK:
1301 /* Generate an INIT ACK chunk. */
1302 new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1303 0);
1304 if (!new_obj)
1305 goto nomem;
1306
1307 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1308 SCTP_CHUNK(new_obj));
1309 break;
1310
1311 case SCTP_CMD_PEER_INIT:
1312 /* Process a unified INIT from the peer.
1313 * Note: Only used during INIT-ACK processing. If
1314 * there is an error just return to the outter
1315 * layer which will bail.
1316 */
1317 error = sctp_cmd_process_init(commands, asoc, chunk,
1318 cmd->obj.ptr, gfp);
1319 break;
1320
1321 case SCTP_CMD_GEN_COOKIE_ECHO:
1322 /* Generate a COOKIE ECHO chunk. */
1323 new_obj = sctp_make_cookie_echo(asoc, chunk);
1324 if (!new_obj) {
1325 if (cmd->obj.ptr)
1326 sctp_chunk_free(cmd->obj.ptr);
1327 goto nomem;
1328 }
1329 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1330 SCTP_CHUNK(new_obj));
1331
1332 /* If there is an ERROR chunk to be sent along with
1333 * the COOKIE_ECHO, send it, too.
1334 */
1335 if (cmd->obj.ptr)
1336 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1337 SCTP_CHUNK(cmd->obj.ptr));
1338
1339 if (new_obj->transport) {
1340 new_obj->transport->init_sent_count++;
1341 asoc->init_last_sent_to = new_obj->transport;
1342 }
1343
1344 /* FIXME - Eventually come up with a cleaner way to
1345 * enabling COOKIE-ECHO + DATA bundling during
1346 * multihoming stale cookie scenarios, the following
1347 * command plays with asoc->peer.retran_path to
1348 * avoid the problem of sending the COOKIE-ECHO and
1349 * DATA in different paths, which could result
1350 * in the association being ABORTed if the DATA chunk
1351 * is processed first by the server. Checking the
1352 * init error counter simply causes this command
1353 * to be executed only during failed attempts of
1354 * association establishment.
1355 */
1356 if ((asoc->peer.retran_path !=
1357 asoc->peer.primary_path) &&
1358 (asoc->init_err_counter > 0)) {
1359 sctp_add_cmd_sf(commands,
1360 SCTP_CMD_FORCE_PRIM_RETRAN,
1361 SCTP_NULL());
1362 }
1363
1364 break;
1365
1366 case SCTP_CMD_GEN_SHUTDOWN:
1367 /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1368 * Reset error counts.
1369 */
1370 asoc->overall_error_count = 0;
1371
1372 /* Generate a SHUTDOWN chunk. */
1373 new_obj = sctp_make_shutdown(asoc, chunk);
1374 if (!new_obj)
1375 goto nomem;
1376 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1377 SCTP_CHUNK(new_obj));
1378 break;
1379
1380 case SCTP_CMD_CHUNK_ULP:
1381 /* Send a chunk to the sockets layer. */
1382 SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1383 "chunk_up:", cmd->obj.ptr,
1384 "ulpq:", &asoc->ulpq);
1385 sctp_ulpq_tail_data(&asoc->ulpq, cmd->obj.ptr,
1386 GFP_ATOMIC);
1387 break;
1388
1389 case SCTP_CMD_EVENT_ULP:
1390 /* Send a notification to the sockets layer. */
1391 SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1392 "event_up:",cmd->obj.ptr,
1393 "ulpq:",&asoc->ulpq);
1394 sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ptr);
1395 break;
1396
1397 case SCTP_CMD_REPLY:
1398 /* If an caller has not already corked, do cork. */
1399 if (!asoc->outqueue.cork) {
1400 sctp_outq_cork(&asoc->outqueue);
1401 local_cork = 1;
1402 }
1403 /* Send a chunk to our peer. */
1404 error = sctp_outq_tail(&asoc->outqueue, cmd->obj.ptr);
1405 break;
1406
1407 case SCTP_CMD_SEND_PKT:
1408 /* Send a full packet to our peer. */
1409 packet = cmd->obj.ptr;
1410 sctp_packet_transmit(packet);
1411 sctp_ootb_pkt_free(packet);
1412 break;
1413
1414 case SCTP_CMD_T1_RETRAN:
1415 /* Mark a transport for retransmission. */
1416 sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1417 SCTP_RTXR_T1_RTX);
1418 break;
1419
1420 case SCTP_CMD_RETRAN:
1421 /* Mark a transport for retransmission. */
1422 sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1423 SCTP_RTXR_T3_RTX);
1424 break;
1425
1426 case SCTP_CMD_ECN_CE:
1427 /* Do delayed CE processing. */
1428 sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1429 break;
1430
1431 case SCTP_CMD_ECN_ECNE:
1432 /* Do delayed ECNE processing. */
1433 new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1434 chunk);
1435 if (new_obj)
1436 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1437 SCTP_CHUNK(new_obj));
1438 break;
1439
1440 case SCTP_CMD_ECN_CWR:
1441 /* Do delayed CWR processing. */
1442 sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1443 break;
1444
1445 case SCTP_CMD_SETUP_T2:
1446 sctp_cmd_setup_t2(commands, asoc, cmd->obj.ptr);
1447 break;
1448
1449 case SCTP_CMD_TIMER_START_ONCE:
1450 timer = &asoc->timers[cmd->obj.to];
1451
1452 if (timer_pending(timer))
1453 break;
1454 /* fall through */
1455
1456 case SCTP_CMD_TIMER_START:
1457 timer = &asoc->timers[cmd->obj.to];
1458 timeout = asoc->timeouts[cmd->obj.to];
1459 BUG_ON(!timeout);
1460
1461 timer->expires = jiffies + timeout;
1462 sctp_association_hold(asoc);
1463 add_timer(timer);
1464 break;
1465
1466 case SCTP_CMD_TIMER_RESTART:
1467 timer = &asoc->timers[cmd->obj.to];
1468 timeout = asoc->timeouts[cmd->obj.to];
1469 if (!mod_timer(timer, jiffies + timeout))
1470 sctp_association_hold(asoc);
1471 break;
1472
1473 case SCTP_CMD_TIMER_STOP:
1474 timer = &asoc->timers[cmd->obj.to];
1475 if (timer_pending(timer) && del_timer(timer))
1476 sctp_association_put(asoc);
1477 break;
1478
1479 case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1480 chunk = cmd->obj.ptr;
1481 t = sctp_assoc_choose_alter_transport(asoc,
1482 asoc->init_last_sent_to);
1483 asoc->init_last_sent_to = t;
1484 chunk->transport = t;
1485 t->init_sent_count++;
1486 /* Set the new transport as primary */
1487 sctp_assoc_set_primary(asoc, t);
1488 break;
1489
1490 case SCTP_CMD_INIT_RESTART:
1491 /* Do the needed accounting and updates
1492 * associated with restarting an initialization
1493 * timer. Only multiply the timeout by two if
1494 * all transports have been tried at the current
1495 * timeout.
1496 */
1497 sctp_cmd_t1_timer_update(asoc,
1498 SCTP_EVENT_TIMEOUT_T1_INIT,
1499 "INIT");
1500
1501 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1502 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1503 break;
1504
1505 case SCTP_CMD_COOKIEECHO_RESTART:
1506 /* Do the needed accounting and updates
1507 * associated with restarting an initialization
1508 * timer. Only multiply the timeout by two if
1509 * all transports have been tried at the current
1510 * timeout.
1511 */
1512 sctp_cmd_t1_timer_update(asoc,
1513 SCTP_EVENT_TIMEOUT_T1_COOKIE,
1514 "COOKIE");
1515
1516 /* If we've sent any data bundled with
1517 * COOKIE-ECHO we need to resend.
1518 */
1519 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1520 transports) {
1521 sctp_retransmit_mark(&asoc->outqueue, t,
1522 SCTP_RTXR_T1_RTX);
1523 }
1524
1525 sctp_add_cmd_sf(commands,
1526 SCTP_CMD_TIMER_RESTART,
1527 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1528 break;
1529
1530 case SCTP_CMD_INIT_FAILED:
1531 sctp_cmd_init_failed(commands, asoc, cmd->obj.err);
1532 break;
1533
1534 case SCTP_CMD_ASSOC_FAILED:
1535 sctp_cmd_assoc_failed(commands, asoc, event_type,
1536 subtype, chunk, cmd->obj.err);
1537 break;
1538
1539 case SCTP_CMD_INIT_COUNTER_INC:
1540 asoc->init_err_counter++;
1541 break;
1542
1543 case SCTP_CMD_INIT_COUNTER_RESET:
1544 asoc->init_err_counter = 0;
1545 asoc->init_cycle = 0;
1546 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1547 transports) {
1548 t->init_sent_count = 0;
1549 }
1550 break;
1551
1552 case SCTP_CMD_REPORT_DUP:
1553 sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1554 cmd->obj.u32);
1555 break;
1556
1557 case SCTP_CMD_REPORT_BAD_TAG:
1558 SCTP_DEBUG_PRINTK("vtag mismatch!\n");
1559 break;
1560
1561 case SCTP_CMD_STRIKE:
1562 /* Mark one strike against a transport. */
1563 sctp_do_8_2_transport_strike(asoc, cmd->obj.transport,
1564 0);
1565 break;
1566
1567 case SCTP_CMD_TRANSPORT_IDLE:
1568 t = cmd->obj.transport;
1569 sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
1570 break;
1571
1572 case SCTP_CMD_TRANSPORT_HB_SENT:
1573 t = cmd->obj.transport;
1574 sctp_do_8_2_transport_strike(asoc, t, 1);
1575 t->hb_sent = 1;
1576 break;
1577
1578 case SCTP_CMD_TRANSPORT_ON:
1579 t = cmd->obj.transport;
1580 sctp_cmd_transport_on(commands, asoc, t, chunk);
1581 break;
1582
1583 case SCTP_CMD_HB_TIMERS_START:
1584 sctp_cmd_hb_timers_start(commands, asoc);
1585 break;
1586
1587 case SCTP_CMD_HB_TIMER_UPDATE:
1588 t = cmd->obj.transport;
1589 sctp_cmd_hb_timer_update(commands, t);
1590 break;
1591
1592 case SCTP_CMD_HB_TIMERS_STOP:
1593 sctp_cmd_hb_timers_stop(commands, asoc);
1594 break;
1595
1596 case SCTP_CMD_REPORT_ERROR:
1597 error = cmd->obj.error;
1598 break;
1599
1600 case SCTP_CMD_PROCESS_CTSN:
1601 /* Dummy up a SACK for processing. */
1602 sackh.cum_tsn_ack = cmd->obj.be32;
1603 sackh.a_rwnd = asoc->peer.rwnd +
1604 asoc->outqueue.outstanding_bytes;
1605 sackh.num_gap_ack_blocks = 0;
1606 sackh.num_dup_tsns = 0;
1607 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1608 SCTP_SACKH(&sackh));
1609 break;
1610
1611 case SCTP_CMD_DISCARD_PACKET:
1612 /* We need to discard the whole packet.
1613 * Uncork the queue since there might be
1614 * responses pending
1615 */
1616 chunk->pdiscard = 1;
1617 if (asoc) {
1618 sctp_outq_uncork(&asoc->outqueue);
1619 local_cork = 0;
1620 }
1621 break;
1622
1623 case SCTP_CMD_RTO_PENDING:
1624 t = cmd->obj.transport;
1625 t->rto_pending = 1;
1626 break;
1627
1628 case SCTP_CMD_PART_DELIVER:
1629 sctp_ulpq_partial_delivery(&asoc->ulpq, cmd->obj.ptr,
1630 GFP_ATOMIC);
1631 break;
1632
1633 case SCTP_CMD_RENEGE:
1634 sctp_ulpq_renege(&asoc->ulpq, cmd->obj.ptr,
1635 GFP_ATOMIC);
1636 break;
1637
1638 case SCTP_CMD_SETUP_T4:
1639 sctp_cmd_setup_t4(commands, asoc, cmd->obj.ptr);
1640 break;
1641
1642 case SCTP_CMD_PROCESS_OPERR:
1643 sctp_cmd_process_operr(commands, asoc, chunk);
1644 break;
1645 case SCTP_CMD_CLEAR_INIT_TAG:
1646 asoc->peer.i.init_tag = 0;
1647 break;
1648 case SCTP_CMD_DEL_NON_PRIMARY:
1649 sctp_cmd_del_non_primary(asoc);
1650 break;
1651 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1652 sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1653 break;
1654 case SCTP_CMD_FORCE_PRIM_RETRAN:
1655 t = asoc->peer.retran_path;
1656 asoc->peer.retran_path = asoc->peer.primary_path;
1657 error = sctp_outq_uncork(&asoc->outqueue);
1658 local_cork = 0;
1659 asoc->peer.retran_path = t;
1660 break;
1661 case SCTP_CMD_SET_SK_ERR:
1662 sctp_cmd_set_sk_err(asoc, cmd->obj.error);
1663 break;
1664 case SCTP_CMD_ASSOC_CHANGE:
1665 sctp_cmd_assoc_change(commands, asoc,
1666 cmd->obj.u8);
1667 break;
1668 case SCTP_CMD_ADAPTATION_IND:
1669 sctp_cmd_adaptation_ind(commands, asoc);
1670 break;
1671
1672 case SCTP_CMD_ASSOC_SHKEY:
1673 error = sctp_auth_asoc_init_active_key(asoc,
1674 GFP_ATOMIC);
1675 break;
1676 case SCTP_CMD_UPDATE_INITTAG:
1677 asoc->peer.i.init_tag = cmd->obj.u32;
1678 break;
1679 case SCTP_CMD_SEND_MSG:
1680 if (!asoc->outqueue.cork) {
1681 sctp_outq_cork(&asoc->outqueue);
1682 local_cork = 1;
1683 }
1684 error = sctp_cmd_send_msg(asoc, cmd->obj.msg);
1685 break;
1686 case SCTP_CMD_SEND_NEXT_ASCONF:
1687 sctp_cmd_send_asconf(asoc);
1688 break;
1689 case SCTP_CMD_PURGE_ASCONF_QUEUE:
1690 sctp_asconf_queue_teardown(asoc);
1691 break;
1692
1693 case SCTP_CMD_SET_ASOC:
1694 asoc = cmd->obj.asoc;
1695 break;
1696
1697 default:
1698 pr_warn("Impossible command: %u, %p\n",
1699 cmd->verb, cmd->obj.ptr);
1700 break;
1701 }
1702
1703 if (error)
1704 break;
1705 }
1706
1707out:
1708 /* If this is in response to a received chunk, wait until
1709 * we are done with the packet to open the queue so that we don't
1710 * send multiple packets in response to a single request.
1711 */
1712 if (asoc && SCTP_EVENT_T_CHUNK == event_type && chunk) {
1713 if (chunk->end_of_packet || chunk->singleton)
1714 error = sctp_outq_uncork(&asoc->outqueue);
1715 } else if (local_cork)
1716 error = sctp_outq_uncork(&asoc->outqueue);
1717 return error;
1718nomem:
1719 error = -ENOMEM;
1720 goto out;
1721}
1722
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#include <net/sctp/stream_sched.h>
54
55static int sctp_cmd_interpreter(enum sctp_event event_type,
56 union sctp_subtype subtype,
57 enum sctp_state state,
58 struct sctp_endpoint *ep,
59 struct sctp_association *asoc,
60 void *event_arg,
61 enum sctp_disposition status,
62 struct sctp_cmd_seq *commands,
63 gfp_t gfp);
64static int sctp_side_effects(enum sctp_event event_type,
65 union sctp_subtype subtype,
66 enum sctp_state state,
67 struct sctp_endpoint *ep,
68 struct sctp_association **asoc,
69 void *event_arg,
70 enum sctp_disposition status,
71 struct sctp_cmd_seq *commands,
72 gfp_t gfp);
73
74/********************************************************************
75 * Helper functions
76 ********************************************************************/
77
78/* A helper function for delayed processing of INET ECN CE bit. */
79static void sctp_do_ecn_ce_work(struct sctp_association *asoc,
80 __u32 lowest_tsn)
81{
82 /* Save the TSN away for comparison when we receive CWR */
83
84 asoc->last_ecne_tsn = lowest_tsn;
85 asoc->need_ecne = 1;
86}
87
88/* Helper function for delayed processing of SCTP ECNE chunk. */
89/* RFC 2960 Appendix A
90 *
91 * RFC 2481 details a specific bit for a sender to send in
92 * the header of its next outbound TCP segment to indicate to
93 * its peer that it has reduced its congestion window. This
94 * is termed the CWR bit. For SCTP the same indication is made
95 * by including the CWR chunk. This chunk contains one data
96 * element, i.e. the TSN number that was sent in the ECNE chunk.
97 * This element represents the lowest TSN number in the datagram
98 * that was originally marked with the CE bit.
99 */
100static struct sctp_chunk *sctp_do_ecn_ecne_work(struct sctp_association *asoc,
101 __u32 lowest_tsn,
102 struct sctp_chunk *chunk)
103{
104 struct sctp_chunk *repl;
105
106 /* Our previously transmitted packet ran into some congestion
107 * so we should take action by reducing cwnd and ssthresh
108 * and then ACK our peer that we we've done so by
109 * sending a CWR.
110 */
111
112 /* First, try to determine if we want to actually lower
113 * our cwnd variables. Only lower them if the ECNE looks more
114 * recent than the last response.
115 */
116 if (TSN_lt(asoc->last_cwr_tsn, lowest_tsn)) {
117 struct sctp_transport *transport;
118
119 /* Find which transport's congestion variables
120 * need to be adjusted.
121 */
122 transport = sctp_assoc_lookup_tsn(asoc, lowest_tsn);
123
124 /* Update the congestion variables. */
125 if (transport)
126 sctp_transport_lower_cwnd(transport,
127 SCTP_LOWER_CWND_ECNE);
128 asoc->last_cwr_tsn = lowest_tsn;
129 }
130
131 /* Always try to quiet the other end. In case of lost CWR,
132 * resend last_cwr_tsn.
133 */
134 repl = sctp_make_cwr(asoc, asoc->last_cwr_tsn, chunk);
135
136 /* If we run out of memory, it will look like a lost CWR. We'll
137 * get back in sync eventually.
138 */
139 return repl;
140}
141
142/* Helper function to do delayed processing of ECN CWR chunk. */
143static void sctp_do_ecn_cwr_work(struct sctp_association *asoc,
144 __u32 lowest_tsn)
145{
146 /* Turn off ECNE getting auto-prepended to every outgoing
147 * packet
148 */
149 asoc->need_ecne = 0;
150}
151
152/* Generate SACK if necessary. We call this at the end of a packet. */
153static int sctp_gen_sack(struct sctp_association *asoc, int force,
154 struct sctp_cmd_seq *commands)
155{
156 struct sctp_transport *trans = asoc->peer.last_data_from;
157 __u32 ctsn, max_tsn_seen;
158 struct sctp_chunk *sack;
159 int error = 0;
160
161 if (force ||
162 (!trans && (asoc->param_flags & SPP_SACKDELAY_DISABLE)) ||
163 (trans && (trans->param_flags & SPP_SACKDELAY_DISABLE)))
164 asoc->peer.sack_needed = 1;
165
166 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
167 max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
168
169 /* From 12.2 Parameters necessary per association (i.e. the TCB):
170 *
171 * Ack State : This flag indicates if the next received packet
172 * : is to be responded to with a SACK. ...
173 * : When DATA chunks are out of order, SACK's
174 * : are not delayed (see Section 6).
175 *
176 * [This is actually not mentioned in Section 6, but we
177 * implement it here anyway. --piggy]
178 */
179 if (max_tsn_seen != ctsn)
180 asoc->peer.sack_needed = 1;
181
182 /* From 6.2 Acknowledgement on Reception of DATA Chunks:
183 *
184 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically,
185 * an acknowledgement SHOULD be generated for at least every
186 * second packet (not every second DATA chunk) received, and
187 * SHOULD be generated within 200 ms of the arrival of any
188 * unacknowledged DATA chunk. ...
189 */
190 if (!asoc->peer.sack_needed) {
191 asoc->peer.sack_cnt++;
192
193 /* Set the SACK delay timeout based on the
194 * SACK delay for the last transport
195 * data was received from, or the default
196 * for the association.
197 */
198 if (trans) {
199 /* We will need a SACK for the next packet. */
200 if (asoc->peer.sack_cnt >= trans->sackfreq - 1)
201 asoc->peer.sack_needed = 1;
202
203 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
204 trans->sackdelay;
205 } else {
206 /* We will need a SACK for the next packet. */
207 if (asoc->peer.sack_cnt >= asoc->sackfreq - 1)
208 asoc->peer.sack_needed = 1;
209
210 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
211 asoc->sackdelay;
212 }
213
214 /* Restart the SACK timer. */
215 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
216 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
217 } else {
218 __u32 old_a_rwnd = asoc->a_rwnd;
219
220 asoc->a_rwnd = asoc->rwnd;
221 sack = sctp_make_sack(asoc);
222 if (!sack) {
223 asoc->a_rwnd = old_a_rwnd;
224 goto nomem;
225 }
226
227 asoc->peer.sack_needed = 0;
228 asoc->peer.sack_cnt = 0;
229
230 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(sack));
231
232 /* Stop the SACK timer. */
233 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
234 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
235 }
236
237 return error;
238nomem:
239 error = -ENOMEM;
240 return error;
241}
242
243/* When the T3-RTX timer expires, it calls this function to create the
244 * relevant state machine event.
245 */
246void sctp_generate_t3_rtx_event(struct timer_list *t)
247{
248 struct sctp_transport *transport =
249 from_timer(transport, t, T3_rtx_timer);
250 struct sctp_association *asoc = transport->asoc;
251 struct sock *sk = asoc->base.sk;
252 struct net *net = sock_net(sk);
253 int error;
254
255 /* Check whether a task is in the sock. */
256
257 bh_lock_sock(sk);
258 if (sock_owned_by_user(sk)) {
259 pr_debug("%s: sock is busy\n", __func__);
260
261 /* Try again later. */
262 if (!mod_timer(&transport->T3_rtx_timer, jiffies + (HZ/20)))
263 sctp_transport_hold(transport);
264 goto out_unlock;
265 }
266
267 /* Run through the state machine. */
268 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
269 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX),
270 asoc->state,
271 asoc->ep, asoc,
272 transport, GFP_ATOMIC);
273
274 if (error)
275 sk->sk_err = -error;
276
277out_unlock:
278 bh_unlock_sock(sk);
279 sctp_transport_put(transport);
280}
281
282/* This is a sa interface for producing timeout events. It works
283 * for timeouts which use the association as their parameter.
284 */
285static void sctp_generate_timeout_event(struct sctp_association *asoc,
286 enum sctp_event_timeout timeout_type)
287{
288 struct sock *sk = asoc->base.sk;
289 struct net *net = sock_net(sk);
290 int error = 0;
291
292 bh_lock_sock(sk);
293 if (sock_owned_by_user(sk)) {
294 pr_debug("%s: sock is busy: timer %d\n", __func__,
295 timeout_type);
296
297 /* Try again later. */
298 if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20)))
299 sctp_association_hold(asoc);
300 goto out_unlock;
301 }
302
303 /* Is this association really dead and just waiting around for
304 * the timer to let go of the reference?
305 */
306 if (asoc->base.dead)
307 goto out_unlock;
308
309 /* Run through the state machine. */
310 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
311 SCTP_ST_TIMEOUT(timeout_type),
312 asoc->state, asoc->ep, asoc,
313 (void *)timeout_type, GFP_ATOMIC);
314
315 if (error)
316 sk->sk_err = -error;
317
318out_unlock:
319 bh_unlock_sock(sk);
320 sctp_association_put(asoc);
321}
322
323static void sctp_generate_t1_cookie_event(struct timer_list *t)
324{
325 struct sctp_association *asoc =
326 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_T1_COOKIE]);
327
328 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
329}
330
331static void sctp_generate_t1_init_event(struct timer_list *t)
332{
333 struct sctp_association *asoc =
334 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_T1_INIT]);
335
336 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
337}
338
339static void sctp_generate_t2_shutdown_event(struct timer_list *t)
340{
341 struct sctp_association *asoc =
342 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN]);
343
344 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
345}
346
347static void sctp_generate_t4_rto_event(struct timer_list *t)
348{
349 struct sctp_association *asoc =
350 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_T4_RTO]);
351
352 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
353}
354
355static void sctp_generate_t5_shutdown_guard_event(struct timer_list *t)
356{
357 struct sctp_association *asoc =
358 from_timer(asoc, t,
359 timers[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD]);
360
361 sctp_generate_timeout_event(asoc,
362 SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);
363
364} /* sctp_generate_t5_shutdown_guard_event() */
365
366static void sctp_generate_autoclose_event(struct timer_list *t)
367{
368 struct sctp_association *asoc =
369 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_AUTOCLOSE]);
370
371 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE);
372}
373
374/* Generate a heart beat event. If the sock is busy, reschedule. Make
375 * sure that the transport is still valid.
376 */
377void sctp_generate_heartbeat_event(struct timer_list *t)
378{
379 struct sctp_transport *transport = from_timer(transport, t, hb_timer);
380 struct sctp_association *asoc = transport->asoc;
381 struct sock *sk = asoc->base.sk;
382 struct net *net = sock_net(sk);
383 u32 elapsed, timeout;
384 int error = 0;
385
386 bh_lock_sock(sk);
387 if (sock_owned_by_user(sk)) {
388 pr_debug("%s: sock is busy\n", __func__);
389
390 /* Try again later. */
391 if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20)))
392 sctp_transport_hold(transport);
393 goto out_unlock;
394 }
395
396 /* Check if we should still send the heartbeat or reschedule */
397 elapsed = jiffies - transport->last_time_sent;
398 timeout = sctp_transport_timeout(transport);
399 if (elapsed < timeout) {
400 elapsed = timeout - elapsed;
401 if (!mod_timer(&transport->hb_timer, jiffies + elapsed))
402 sctp_transport_hold(transport);
403 goto out_unlock;
404 }
405
406 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
407 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
408 asoc->state, asoc->ep, asoc,
409 transport, GFP_ATOMIC);
410
411 if (error)
412 sk->sk_err = -error;
413
414out_unlock:
415 bh_unlock_sock(sk);
416 sctp_transport_put(transport);
417}
418
419/* Handle the timeout of the ICMP protocol unreachable timer. Trigger
420 * the correct state machine transition that will close the association.
421 */
422void sctp_generate_proto_unreach_event(struct timer_list *t)
423{
424 struct sctp_transport *transport =
425 from_timer(transport, t, proto_unreach_timer);
426 struct sctp_association *asoc = transport->asoc;
427 struct sock *sk = asoc->base.sk;
428 struct net *net = sock_net(sk);
429
430 bh_lock_sock(sk);
431 if (sock_owned_by_user(sk)) {
432 pr_debug("%s: sock is busy\n", __func__);
433
434 /* Try again later. */
435 if (!mod_timer(&transport->proto_unreach_timer,
436 jiffies + (HZ/20)))
437 sctp_association_hold(asoc);
438 goto out_unlock;
439 }
440
441 /* Is this structure just waiting around for us to actually
442 * get destroyed?
443 */
444 if (asoc->base.dead)
445 goto out_unlock;
446
447 sctp_do_sm(net, SCTP_EVENT_T_OTHER,
448 SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH),
449 asoc->state, asoc->ep, asoc, transport, GFP_ATOMIC);
450
451out_unlock:
452 bh_unlock_sock(sk);
453 sctp_association_put(asoc);
454}
455
456 /* Handle the timeout of the RE-CONFIG timer. */
457void sctp_generate_reconf_event(struct timer_list *t)
458{
459 struct sctp_transport *transport =
460 from_timer(transport, t, reconf_timer);
461 struct sctp_association *asoc = transport->asoc;
462 struct sock *sk = asoc->base.sk;
463 struct net *net = sock_net(sk);
464 int error = 0;
465
466 bh_lock_sock(sk);
467 if (sock_owned_by_user(sk)) {
468 pr_debug("%s: sock is busy\n", __func__);
469
470 /* Try again later. */
471 if (!mod_timer(&transport->reconf_timer, jiffies + (HZ / 20)))
472 sctp_transport_hold(transport);
473 goto out_unlock;
474 }
475
476 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
477 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_RECONF),
478 asoc->state, asoc->ep, asoc,
479 transport, GFP_ATOMIC);
480
481 if (error)
482 sk->sk_err = -error;
483
484out_unlock:
485 bh_unlock_sock(sk);
486 sctp_transport_put(transport);
487}
488
489/* Inject a SACK Timeout event into the state machine. */
490static void sctp_generate_sack_event(struct timer_list *t)
491{
492 struct sctp_association *asoc =
493 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_SACK]);
494
495 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
496}
497
498sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
499 [SCTP_EVENT_TIMEOUT_NONE] = NULL,
500 [SCTP_EVENT_TIMEOUT_T1_COOKIE] = sctp_generate_t1_cookie_event,
501 [SCTP_EVENT_TIMEOUT_T1_INIT] = sctp_generate_t1_init_event,
502 [SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = sctp_generate_t2_shutdown_event,
503 [SCTP_EVENT_TIMEOUT_T3_RTX] = NULL,
504 [SCTP_EVENT_TIMEOUT_T4_RTO] = sctp_generate_t4_rto_event,
505 [SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD] =
506 sctp_generate_t5_shutdown_guard_event,
507 [SCTP_EVENT_TIMEOUT_HEARTBEAT] = NULL,
508 [SCTP_EVENT_TIMEOUT_RECONF] = NULL,
509 [SCTP_EVENT_TIMEOUT_SACK] = sctp_generate_sack_event,
510 [SCTP_EVENT_TIMEOUT_AUTOCLOSE] = sctp_generate_autoclose_event,
511};
512
513
514/* RFC 2960 8.2 Path Failure Detection
515 *
516 * When its peer endpoint is multi-homed, an endpoint should keep a
517 * error counter for each of the destination transport addresses of the
518 * peer endpoint.
519 *
520 * Each time the T3-rtx timer expires on any address, or when a
521 * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
522 * the error counter of that destination address will be incremented.
523 * When the value in the error counter exceeds the protocol parameter
524 * 'Path.Max.Retrans' of that destination address, the endpoint should
525 * mark the destination transport address as inactive, and a
526 * notification SHOULD be sent to the upper layer.
527 *
528 */
529static void sctp_do_8_2_transport_strike(struct sctp_cmd_seq *commands,
530 struct sctp_association *asoc,
531 struct sctp_transport *transport,
532 int is_hb)
533{
534 struct net *net = sock_net(asoc->base.sk);
535
536 /* The check for association's overall error counter exceeding the
537 * threshold is done in the state function.
538 */
539 /* We are here due to a timer expiration. If the timer was
540 * not a HEARTBEAT, then normal error tracking is done.
541 * If the timer was a heartbeat, we only increment error counts
542 * when we already have an outstanding HEARTBEAT that has not
543 * been acknowledged.
544 * Additionally, some tranport states inhibit error increments.
545 */
546 if (!is_hb) {
547 asoc->overall_error_count++;
548 if (transport->state != SCTP_INACTIVE)
549 transport->error_count++;
550 } else if (transport->hb_sent) {
551 if (transport->state != SCTP_UNCONFIRMED)
552 asoc->overall_error_count++;
553 if (transport->state != SCTP_INACTIVE)
554 transport->error_count++;
555 }
556
557 /* If the transport error count is greater than the pf_retrans
558 * threshold, and less than pathmaxrtx, and if the current state
559 * is SCTP_ACTIVE, then mark this transport as Partially Failed,
560 * see SCTP Quick Failover Draft, section 5.1
561 */
562 if (net->sctp.pf_enable &&
563 (transport->state == SCTP_ACTIVE) &&
564 (asoc->pf_retrans < transport->pathmaxrxt) &&
565 (transport->error_count > asoc->pf_retrans)) {
566
567 sctp_assoc_control_transport(asoc, transport,
568 SCTP_TRANSPORT_PF,
569 0);
570
571 /* Update the hb timer to resend a heartbeat every rto */
572 sctp_transport_reset_hb_timer(transport);
573 }
574
575 if (transport->state != SCTP_INACTIVE &&
576 (transport->error_count > transport->pathmaxrxt)) {
577 pr_debug("%s: association:%p transport addr:%pISpc failed\n",
578 __func__, asoc, &transport->ipaddr.sa);
579
580 sctp_assoc_control_transport(asoc, transport,
581 SCTP_TRANSPORT_DOWN,
582 SCTP_FAILED_THRESHOLD);
583 }
584
585 /* E2) For the destination address for which the timer
586 * expires, set RTO <- RTO * 2 ("back off the timer"). The
587 * maximum value discussed in rule C7 above (RTO.max) may be
588 * used to provide an upper bound to this doubling operation.
589 *
590 * Special Case: the first HB doesn't trigger exponential backoff.
591 * The first unacknowledged HB triggers it. We do this with a flag
592 * that indicates that we have an outstanding HB.
593 */
594 if (!is_hb || transport->hb_sent) {
595 transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
596 sctp_max_rto(asoc, transport);
597 }
598}
599
600/* Worker routine to handle INIT command failure. */
601static void sctp_cmd_init_failed(struct sctp_cmd_seq *commands,
602 struct sctp_association *asoc,
603 unsigned int error)
604{
605 struct sctp_ulpevent *event;
606
607 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_CANT_STR_ASSOC,
608 (__u16)error, 0, 0, NULL,
609 GFP_ATOMIC);
610
611 if (event)
612 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
613 SCTP_ULPEVENT(event));
614
615 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
616 SCTP_STATE(SCTP_STATE_CLOSED));
617
618 /* SEND_FAILED sent later when cleaning up the association. */
619 asoc->outqueue.error = error;
620 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
621}
622
623/* Worker routine to handle SCTP_CMD_ASSOC_FAILED. */
624static void sctp_cmd_assoc_failed(struct sctp_cmd_seq *commands,
625 struct sctp_association *asoc,
626 enum sctp_event event_type,
627 union sctp_subtype subtype,
628 struct sctp_chunk *chunk,
629 unsigned int error)
630{
631 struct sctp_ulpevent *event;
632 struct sctp_chunk *abort;
633
634 /* Cancel any partial delivery in progress. */
635 asoc->stream.si->abort_pd(&asoc->ulpq, GFP_ATOMIC);
636
637 if (event_type == SCTP_EVENT_T_CHUNK && subtype.chunk == SCTP_CID_ABORT)
638 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
639 (__u16)error, 0, 0, chunk,
640 GFP_ATOMIC);
641 else
642 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
643 (__u16)error, 0, 0, NULL,
644 GFP_ATOMIC);
645 if (event)
646 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
647 SCTP_ULPEVENT(event));
648
649 if (asoc->overall_error_count >= asoc->max_retrans) {
650 abort = sctp_make_violation_max_retrans(asoc, chunk);
651 if (abort)
652 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
653 SCTP_CHUNK(abort));
654 }
655
656 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
657 SCTP_STATE(SCTP_STATE_CLOSED));
658
659 /* SEND_FAILED sent later when cleaning up the association. */
660 asoc->outqueue.error = error;
661 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
662}
663
664/* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
665 * inside the cookie. In reality, this is only used for INIT-ACK processing
666 * since all other cases use "temporary" associations and can do all
667 * their work in statefuns directly.
668 */
669static int sctp_cmd_process_init(struct sctp_cmd_seq *commands,
670 struct sctp_association *asoc,
671 struct sctp_chunk *chunk,
672 struct sctp_init_chunk *peer_init,
673 gfp_t gfp)
674{
675 int error;
676
677 /* We only process the init as a sideeffect in a single
678 * case. This is when we process the INIT-ACK. If we
679 * fail during INIT processing (due to malloc problems),
680 * just return the error and stop processing the stack.
681 */
682 if (!sctp_process_init(asoc, chunk, sctp_source(chunk), peer_init, gfp))
683 error = -ENOMEM;
684 else
685 error = 0;
686
687 return error;
688}
689
690/* Helper function to break out starting up of heartbeat timers. */
691static void sctp_cmd_hb_timers_start(struct sctp_cmd_seq *cmds,
692 struct sctp_association *asoc)
693{
694 struct sctp_transport *t;
695
696 /* Start a heartbeat timer for each transport on the association.
697 * hold a reference on the transport to make sure none of
698 * the needed data structures go away.
699 */
700 list_for_each_entry(t, &asoc->peer.transport_addr_list, transports)
701 sctp_transport_reset_hb_timer(t);
702}
703
704static void sctp_cmd_hb_timers_stop(struct sctp_cmd_seq *cmds,
705 struct sctp_association *asoc)
706{
707 struct sctp_transport *t;
708
709 /* Stop all heartbeat timers. */
710
711 list_for_each_entry(t, &asoc->peer.transport_addr_list,
712 transports) {
713 if (del_timer(&t->hb_timer))
714 sctp_transport_put(t);
715 }
716}
717
718/* Helper function to stop any pending T3-RTX timers */
719static void sctp_cmd_t3_rtx_timers_stop(struct sctp_cmd_seq *cmds,
720 struct sctp_association *asoc)
721{
722 struct sctp_transport *t;
723
724 list_for_each_entry(t, &asoc->peer.transport_addr_list,
725 transports) {
726 if (del_timer(&t->T3_rtx_timer))
727 sctp_transport_put(t);
728 }
729}
730
731
732/* Helper function to handle the reception of an HEARTBEAT ACK. */
733static void sctp_cmd_transport_on(struct sctp_cmd_seq *cmds,
734 struct sctp_association *asoc,
735 struct sctp_transport *t,
736 struct sctp_chunk *chunk)
737{
738 struct sctp_sender_hb_info *hbinfo;
739 int was_unconfirmed = 0;
740
741 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
742 * HEARTBEAT should clear the error counter of the destination
743 * transport address to which the HEARTBEAT was sent.
744 */
745 t->error_count = 0;
746
747 /*
748 * Although RFC4960 specifies that the overall error count must
749 * be cleared when a HEARTBEAT ACK is received, we make an
750 * exception while in SHUTDOWN PENDING. If the peer keeps its
751 * window shut forever, we may never be able to transmit our
752 * outstanding data and rely on the retransmission limit be reached
753 * to shutdown the association.
754 */
755 if (t->asoc->state < SCTP_STATE_SHUTDOWN_PENDING)
756 t->asoc->overall_error_count = 0;
757
758 /* Clear the hb_sent flag to signal that we had a good
759 * acknowledgement.
760 */
761 t->hb_sent = 0;
762
763 /* Mark the destination transport address as active if it is not so
764 * marked.
765 */
766 if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED)) {
767 was_unconfirmed = 1;
768 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
769 SCTP_HEARTBEAT_SUCCESS);
770 }
771
772 if (t->state == SCTP_PF)
773 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
774 SCTP_HEARTBEAT_SUCCESS);
775
776 /* HB-ACK was received for a the proper HB. Consider this
777 * forward progress.
778 */
779 if (t->dst)
780 sctp_transport_dst_confirm(t);
781
782 /* The receiver of the HEARTBEAT ACK should also perform an
783 * RTT measurement for that destination transport address
784 * using the time value carried in the HEARTBEAT ACK chunk.
785 * If the transport's rto_pending variable has been cleared,
786 * it was most likely due to a retransmit. However, we want
787 * to re-enable it to properly update the rto.
788 */
789 if (t->rto_pending == 0)
790 t->rto_pending = 1;
791
792 hbinfo = (struct sctp_sender_hb_info *)chunk->skb->data;
793 sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
794
795 /* Update the heartbeat timer. */
796 sctp_transport_reset_hb_timer(t);
797
798 if (was_unconfirmed && asoc->peer.transport_count == 1)
799 sctp_transport_immediate_rtx(t);
800}
801
802
803/* Helper function to process the process SACK command. */
804static int sctp_cmd_process_sack(struct sctp_cmd_seq *cmds,
805 struct sctp_association *asoc,
806 struct sctp_chunk *chunk)
807{
808 int err = 0;
809
810 if (sctp_outq_sack(&asoc->outqueue, chunk)) {
811 struct net *net = sock_net(asoc->base.sk);
812
813 /* There are no more TSNs awaiting SACK. */
814 err = sctp_do_sm(net, SCTP_EVENT_T_OTHER,
815 SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
816 asoc->state, asoc->ep, asoc, NULL,
817 GFP_ATOMIC);
818 }
819
820 return err;
821}
822
823/* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
824 * the transport for a shutdown chunk.
825 */
826static void sctp_cmd_setup_t2(struct sctp_cmd_seq *cmds,
827 struct sctp_association *asoc,
828 struct sctp_chunk *chunk)
829{
830 struct sctp_transport *t;
831
832 if (chunk->transport)
833 t = chunk->transport;
834 else {
835 t = sctp_assoc_choose_alter_transport(asoc,
836 asoc->shutdown_last_sent_to);
837 chunk->transport = t;
838 }
839 asoc->shutdown_last_sent_to = t;
840 asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
841}
842
843static void sctp_cmd_assoc_update(struct sctp_cmd_seq *cmds,
844 struct sctp_association *asoc,
845 struct sctp_association *new)
846{
847 struct net *net = sock_net(asoc->base.sk);
848 struct sctp_chunk *abort;
849
850 if (!sctp_assoc_update(asoc, new))
851 return;
852
853 abort = sctp_make_abort(asoc, NULL, sizeof(struct sctp_errhdr));
854 if (abort) {
855 sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0);
856 sctp_add_cmd_sf(cmds, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
857 }
858 sctp_add_cmd_sf(cmds, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNABORTED));
859 sctp_add_cmd_sf(cmds, SCTP_CMD_ASSOC_FAILED,
860 SCTP_PERR(SCTP_ERROR_RSRC_LOW));
861 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
862 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
863}
864
865/* Helper function to change the state of an association. */
866static void sctp_cmd_new_state(struct sctp_cmd_seq *cmds,
867 struct sctp_association *asoc,
868 enum sctp_state state)
869{
870 struct sock *sk = asoc->base.sk;
871
872 asoc->state = state;
873
874 pr_debug("%s: asoc:%p[%s]\n", __func__, asoc, sctp_state_tbl[state]);
875
876 if (sctp_style(sk, TCP)) {
877 /* Change the sk->sk_state of a TCP-style socket that has
878 * successfully completed a connect() call.
879 */
880 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
881 inet_sk_set_state(sk, SCTP_SS_ESTABLISHED);
882
883 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
884 if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
885 sctp_sstate(sk, ESTABLISHED)) {
886 inet_sk_set_state(sk, SCTP_SS_CLOSING);
887 sk->sk_shutdown |= RCV_SHUTDOWN;
888 }
889 }
890
891 if (sctp_state(asoc, COOKIE_WAIT)) {
892 /* Reset init timeouts since they may have been
893 * increased due to timer expirations.
894 */
895 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
896 asoc->rto_initial;
897 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
898 asoc->rto_initial;
899 }
900
901 if (sctp_state(asoc, ESTABLISHED) ||
902 sctp_state(asoc, CLOSED) ||
903 sctp_state(asoc, SHUTDOWN_RECEIVED)) {
904 /* Wake up any processes waiting in the asoc's wait queue in
905 * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
906 */
907 if (waitqueue_active(&asoc->wait))
908 wake_up_interruptible(&asoc->wait);
909
910 /* Wake up any processes waiting in the sk's sleep queue of
911 * a TCP-style or UDP-style peeled-off socket in
912 * sctp_wait_for_accept() or sctp_wait_for_packet().
913 * For a UDP-style socket, the waiters are woken up by the
914 * notifications.
915 */
916 if (!sctp_style(sk, UDP))
917 sk->sk_state_change(sk);
918 }
919
920 if (sctp_state(asoc, SHUTDOWN_PENDING) &&
921 !sctp_outq_is_empty(&asoc->outqueue))
922 sctp_outq_uncork(&asoc->outqueue, GFP_ATOMIC);
923}
924
925/* Helper function to delete an association. */
926static void sctp_cmd_delete_tcb(struct sctp_cmd_seq *cmds,
927 struct sctp_association *asoc)
928{
929 struct sock *sk = asoc->base.sk;
930
931 /* If it is a non-temporary association belonging to a TCP-style
932 * listening socket that is not closed, do not free it so that accept()
933 * can pick it up later.
934 */
935 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
936 (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
937 return;
938
939 sctp_association_free(asoc);
940}
941
942/*
943 * ADDIP Section 4.1 ASCONF Chunk Procedures
944 * A4) Start a T-4 RTO timer, using the RTO value of the selected
945 * destination address (we use active path instead of primary path just
946 * because primary path may be inactive.
947 */
948static void sctp_cmd_setup_t4(struct sctp_cmd_seq *cmds,
949 struct sctp_association *asoc,
950 struct sctp_chunk *chunk)
951{
952 struct sctp_transport *t;
953
954 t = sctp_assoc_choose_alter_transport(asoc, chunk->transport);
955 asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
956 chunk->transport = t;
957}
958
959/* Process an incoming Operation Error Chunk. */
960static void sctp_cmd_process_operr(struct sctp_cmd_seq *cmds,
961 struct sctp_association *asoc,
962 struct sctp_chunk *chunk)
963{
964 struct sctp_errhdr *err_hdr;
965 struct sctp_ulpevent *ev;
966
967 while (chunk->chunk_end > chunk->skb->data) {
968 err_hdr = (struct sctp_errhdr *)(chunk->skb->data);
969
970 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
971 GFP_ATOMIC);
972 if (!ev)
973 return;
974
975 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
976
977 switch (err_hdr->cause) {
978 case SCTP_ERROR_UNKNOWN_CHUNK:
979 {
980 struct sctp_chunkhdr *unk_chunk_hdr;
981
982 unk_chunk_hdr = (struct sctp_chunkhdr *)
983 err_hdr->variable;
984 switch (unk_chunk_hdr->type) {
985 /* ADDIP 4.1 A9) If the peer responds to an ASCONF with
986 * an ERROR chunk reporting that it did not recognized
987 * the ASCONF chunk type, the sender of the ASCONF MUST
988 * NOT send any further ASCONF chunks and MUST stop its
989 * T-4 timer.
990 */
991 case SCTP_CID_ASCONF:
992 if (asoc->peer.asconf_capable == 0)
993 break;
994
995 asoc->peer.asconf_capable = 0;
996 sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
997 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
998 break;
999 default:
1000 break;
1001 }
1002 break;
1003 }
1004 default:
1005 break;
1006 }
1007 }
1008}
1009
1010/* Helper function to remove the association non-primary peer
1011 * transports.
1012 */
1013static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
1014{
1015 struct sctp_transport *t;
1016 struct list_head *temp;
1017 struct list_head *pos;
1018
1019 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
1020 t = list_entry(pos, struct sctp_transport, transports);
1021 if (!sctp_cmp_addr_exact(&t->ipaddr,
1022 &asoc->peer.primary_addr)) {
1023 sctp_assoc_rm_peer(asoc, t);
1024 }
1025 }
1026}
1027
1028/* Helper function to set sk_err on a 1-1 style socket. */
1029static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
1030{
1031 struct sock *sk = asoc->base.sk;
1032
1033 if (!sctp_style(sk, UDP))
1034 sk->sk_err = error;
1035}
1036
1037/* Helper function to generate an association change event */
1038static void sctp_cmd_assoc_change(struct sctp_cmd_seq *commands,
1039 struct sctp_association *asoc,
1040 u8 state)
1041{
1042 struct sctp_ulpevent *ev;
1043
1044 ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0,
1045 asoc->c.sinit_num_ostreams,
1046 asoc->c.sinit_max_instreams,
1047 NULL, GFP_ATOMIC);
1048 if (ev)
1049 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
1050}
1051
1052static void sctp_cmd_peer_no_auth(struct sctp_cmd_seq *commands,
1053 struct sctp_association *asoc)
1054{
1055 struct sctp_ulpevent *ev;
1056
1057 ev = sctp_ulpevent_make_authkey(asoc, 0, SCTP_AUTH_NO_AUTH, GFP_ATOMIC);
1058 if (ev)
1059 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
1060}
1061
1062/* Helper function to generate an adaptation indication event */
1063static void sctp_cmd_adaptation_ind(struct sctp_cmd_seq *commands,
1064 struct sctp_association *asoc)
1065{
1066 struct sctp_ulpevent *ev;
1067
1068 ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
1069
1070 if (ev)
1071 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
1072}
1073
1074
1075static void sctp_cmd_t1_timer_update(struct sctp_association *asoc,
1076 enum sctp_event_timeout timer,
1077 char *name)
1078{
1079 struct sctp_transport *t;
1080
1081 t = asoc->init_last_sent_to;
1082 asoc->init_err_counter++;
1083
1084 if (t->init_sent_count > (asoc->init_cycle + 1)) {
1085 asoc->timeouts[timer] *= 2;
1086 if (asoc->timeouts[timer] > asoc->max_init_timeo) {
1087 asoc->timeouts[timer] = asoc->max_init_timeo;
1088 }
1089 asoc->init_cycle++;
1090
1091 pr_debug("%s: T1[%s] timeout adjustment init_err_counter:%d"
1092 " cycle:%d timeout:%ld\n", __func__, name,
1093 asoc->init_err_counter, asoc->init_cycle,
1094 asoc->timeouts[timer]);
1095 }
1096
1097}
1098
1099/* Send the whole message, chunk by chunk, to the outqueue.
1100 * This way the whole message is queued up and bundling if
1101 * encouraged for small fragments.
1102 */
1103static void sctp_cmd_send_msg(struct sctp_association *asoc,
1104 struct sctp_datamsg *msg, gfp_t gfp)
1105{
1106 struct sctp_chunk *chunk;
1107
1108 list_for_each_entry(chunk, &msg->chunks, frag_list)
1109 sctp_outq_tail(&asoc->outqueue, chunk, gfp);
1110
1111 asoc->outqueue.sched->enqueue(&asoc->outqueue, msg);
1112}
1113
1114
1115/* Sent the next ASCONF packet currently stored in the association.
1116 * This happens after the ASCONF_ACK was succeffully processed.
1117 */
1118static void sctp_cmd_send_asconf(struct sctp_association *asoc)
1119{
1120 struct net *net = sock_net(asoc->base.sk);
1121
1122 /* Send the next asconf chunk from the addip chunk
1123 * queue.
1124 */
1125 if (!list_empty(&asoc->addip_chunk_list)) {
1126 struct list_head *entry = asoc->addip_chunk_list.next;
1127 struct sctp_chunk *asconf = list_entry(entry,
1128 struct sctp_chunk, list);
1129 list_del_init(entry);
1130
1131 /* Hold the chunk until an ASCONF_ACK is received. */
1132 sctp_chunk_hold(asconf);
1133 if (sctp_primitive_ASCONF(net, asoc, asconf))
1134 sctp_chunk_free(asconf);
1135 else
1136 asoc->addip_last_asconf = asconf;
1137 }
1138}
1139
1140
1141/* These three macros allow us to pull the debugging code out of the
1142 * main flow of sctp_do_sm() to keep attention focused on the real
1143 * functionality there.
1144 */
1145#define debug_pre_sfn() \
1146 pr_debug("%s[pre-fn]: ep:%p, %s, %s, asoc:%p[%s], %s\n", __func__, \
1147 ep, sctp_evttype_tbl[event_type], (*debug_fn)(subtype), \
1148 asoc, sctp_state_tbl[state], state_fn->name)
1149
1150#define debug_post_sfn() \
1151 pr_debug("%s[post-fn]: asoc:%p, status:%s\n", __func__, asoc, \
1152 sctp_status_tbl[status])
1153
1154#define debug_post_sfx() \
1155 pr_debug("%s[post-sfx]: error:%d, asoc:%p[%s]\n", __func__, error, \
1156 asoc, sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
1157 sctp_assoc2id(asoc))) ? asoc->state : SCTP_STATE_CLOSED])
1158
1159/*
1160 * This is the master state machine processing function.
1161 *
1162 * If you want to understand all of lksctp, this is a
1163 * good place to start.
1164 */
1165int sctp_do_sm(struct net *net, enum sctp_event event_type,
1166 union sctp_subtype subtype, enum sctp_state state,
1167 struct sctp_endpoint *ep, struct sctp_association *asoc,
1168 void *event_arg, gfp_t gfp)
1169{
1170 typedef const char *(printfn_t)(union sctp_subtype);
1171 static printfn_t *table[] = {
1172 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
1173 };
1174 printfn_t *debug_fn __attribute__ ((unused)) = table[event_type];
1175 const struct sctp_sm_table_entry *state_fn;
1176 struct sctp_cmd_seq commands;
1177 enum sctp_disposition status;
1178 int error = 0;
1179
1180 /* Look up the state function, run it, and then process the
1181 * side effects. These three steps are the heart of lksctp.
1182 */
1183 state_fn = sctp_sm_lookup_event(net, event_type, state, subtype);
1184
1185 sctp_init_cmd_seq(&commands);
1186
1187 debug_pre_sfn();
1188 status = state_fn->fn(net, ep, asoc, subtype, event_arg, &commands);
1189 debug_post_sfn();
1190
1191 error = sctp_side_effects(event_type, subtype, state,
1192 ep, &asoc, event_arg, status,
1193 &commands, gfp);
1194 debug_post_sfx();
1195
1196 return error;
1197}
1198
1199/*****************************************************************
1200 * This the master state function side effect processing function.
1201 *****************************************************************/
1202static int sctp_side_effects(enum sctp_event event_type,
1203 union sctp_subtype subtype,
1204 enum sctp_state state,
1205 struct sctp_endpoint *ep,
1206 struct sctp_association **asoc,
1207 void *event_arg,
1208 enum sctp_disposition status,
1209 struct sctp_cmd_seq *commands,
1210 gfp_t gfp)
1211{
1212 int error;
1213
1214 /* FIXME - Most of the dispositions left today would be categorized
1215 * as "exceptional" dispositions. For those dispositions, it
1216 * may not be proper to run through any of the commands at all.
1217 * For example, the command interpreter might be run only with
1218 * disposition SCTP_DISPOSITION_CONSUME.
1219 */
1220 if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
1221 ep, *asoc,
1222 event_arg, status,
1223 commands, gfp)))
1224 goto bail;
1225
1226 switch (status) {
1227 case SCTP_DISPOSITION_DISCARD:
1228 pr_debug("%s: ignored sctp protocol event - state:%d, "
1229 "event_type:%d, event_id:%d\n", __func__, state,
1230 event_type, subtype.chunk);
1231 break;
1232
1233 case SCTP_DISPOSITION_NOMEM:
1234 /* We ran out of memory, so we need to discard this
1235 * packet.
1236 */
1237 /* BUG--we should now recover some memory, probably by
1238 * reneging...
1239 */
1240 error = -ENOMEM;
1241 break;
1242
1243 case SCTP_DISPOSITION_DELETE_TCB:
1244 case SCTP_DISPOSITION_ABORT:
1245 /* This should now be a command. */
1246 *asoc = NULL;
1247 break;
1248
1249 case SCTP_DISPOSITION_CONSUME:
1250 /*
1251 * We should no longer have much work to do here as the
1252 * real work has been done as explicit commands above.
1253 */
1254 break;
1255
1256 case SCTP_DISPOSITION_VIOLATION:
1257 net_err_ratelimited("protocol violation state %d chunkid %d\n",
1258 state, subtype.chunk);
1259 break;
1260
1261 case SCTP_DISPOSITION_NOT_IMPL:
1262 pr_warn("unimplemented feature in state %d, event_type %d, event_id %d\n",
1263 state, event_type, subtype.chunk);
1264 break;
1265
1266 case SCTP_DISPOSITION_BUG:
1267 pr_err("bug in state %d, event_type %d, event_id %d\n",
1268 state, event_type, subtype.chunk);
1269 BUG();
1270 break;
1271
1272 default:
1273 pr_err("impossible disposition %d in state %d, event_type %d, event_id %d\n",
1274 status, state, event_type, subtype.chunk);
1275 BUG();
1276 break;
1277 }
1278
1279bail:
1280 return error;
1281}
1282
1283/********************************************************************
1284 * 2nd Level Abstractions
1285 ********************************************************************/
1286
1287/* This is the side-effect interpreter. */
1288static int sctp_cmd_interpreter(enum sctp_event event_type,
1289 union sctp_subtype subtype,
1290 enum sctp_state state,
1291 struct sctp_endpoint *ep,
1292 struct sctp_association *asoc,
1293 void *event_arg,
1294 enum sctp_disposition status,
1295 struct sctp_cmd_seq *commands,
1296 gfp_t gfp)
1297{
1298 struct sctp_sock *sp = sctp_sk(ep->base.sk);
1299 struct sctp_chunk *chunk = NULL, *new_obj;
1300 struct sctp_packet *packet;
1301 struct sctp_sackhdr sackh;
1302 struct timer_list *timer;
1303 struct sctp_transport *t;
1304 unsigned long timeout;
1305 struct sctp_cmd *cmd;
1306 int local_cork = 0;
1307 int error = 0;
1308 int force;
1309
1310 if (SCTP_EVENT_T_TIMEOUT != event_type)
1311 chunk = event_arg;
1312
1313 /* Note: This whole file is a huge candidate for rework.
1314 * For example, each command could either have its own handler, so
1315 * the loop would look like:
1316 * while (cmds)
1317 * cmd->handle(x, y, z)
1318 * --jgrimm
1319 */
1320 while (NULL != (cmd = sctp_next_cmd(commands))) {
1321 switch (cmd->verb) {
1322 case SCTP_CMD_NOP:
1323 /* Do nothing. */
1324 break;
1325
1326 case SCTP_CMD_NEW_ASOC:
1327 /* Register a new association. */
1328 if (local_cork) {
1329 sctp_outq_uncork(&asoc->outqueue, gfp);
1330 local_cork = 0;
1331 }
1332
1333 /* Register with the endpoint. */
1334 asoc = cmd->obj.asoc;
1335 BUG_ON(asoc->peer.primary_path == NULL);
1336 sctp_endpoint_add_asoc(ep, asoc);
1337 break;
1338
1339 case SCTP_CMD_UPDATE_ASSOC:
1340 sctp_cmd_assoc_update(commands, asoc, cmd->obj.asoc);
1341 break;
1342
1343 case SCTP_CMD_PURGE_OUTQUEUE:
1344 sctp_outq_teardown(&asoc->outqueue);
1345 break;
1346
1347 case SCTP_CMD_DELETE_TCB:
1348 if (local_cork) {
1349 sctp_outq_uncork(&asoc->outqueue, gfp);
1350 local_cork = 0;
1351 }
1352 /* Delete the current association. */
1353 sctp_cmd_delete_tcb(commands, asoc);
1354 asoc = NULL;
1355 break;
1356
1357 case SCTP_CMD_NEW_STATE:
1358 /* Enter a new state. */
1359 sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1360 break;
1361
1362 case SCTP_CMD_REPORT_TSN:
1363 /* Record the arrival of a TSN. */
1364 error = sctp_tsnmap_mark(&asoc->peer.tsn_map,
1365 cmd->obj.u32, NULL);
1366 break;
1367
1368 case SCTP_CMD_REPORT_FWDTSN:
1369 asoc->stream.si->report_ftsn(&asoc->ulpq, cmd->obj.u32);
1370 break;
1371
1372 case SCTP_CMD_PROCESS_FWDTSN:
1373 asoc->stream.si->handle_ftsn(&asoc->ulpq,
1374 cmd->obj.chunk);
1375 break;
1376
1377 case SCTP_CMD_GEN_SACK:
1378 /* Generate a Selective ACK.
1379 * The argument tells us whether to just count
1380 * the packet and MAYBE generate a SACK, or
1381 * force a SACK out.
1382 */
1383 force = cmd->obj.i32;
1384 error = sctp_gen_sack(asoc, force, commands);
1385 break;
1386
1387 case SCTP_CMD_PROCESS_SACK:
1388 /* Process an inbound SACK. */
1389 error = sctp_cmd_process_sack(commands, asoc,
1390 cmd->obj.chunk);
1391 break;
1392
1393 case SCTP_CMD_GEN_INIT_ACK:
1394 /* Generate an INIT ACK chunk. */
1395 new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1396 0);
1397 if (!new_obj)
1398 goto nomem;
1399
1400 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1401 SCTP_CHUNK(new_obj));
1402 break;
1403
1404 case SCTP_CMD_PEER_INIT:
1405 /* Process a unified INIT from the peer.
1406 * Note: Only used during INIT-ACK processing. If
1407 * there is an error just return to the outter
1408 * layer which will bail.
1409 */
1410 error = sctp_cmd_process_init(commands, asoc, chunk,
1411 cmd->obj.init, gfp);
1412 break;
1413
1414 case SCTP_CMD_GEN_COOKIE_ECHO:
1415 /* Generate a COOKIE ECHO chunk. */
1416 new_obj = sctp_make_cookie_echo(asoc, chunk);
1417 if (!new_obj) {
1418 if (cmd->obj.chunk)
1419 sctp_chunk_free(cmd->obj.chunk);
1420 goto nomem;
1421 }
1422 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1423 SCTP_CHUNK(new_obj));
1424
1425 /* If there is an ERROR chunk to be sent along with
1426 * the COOKIE_ECHO, send it, too.
1427 */
1428 if (cmd->obj.chunk)
1429 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1430 SCTP_CHUNK(cmd->obj.chunk));
1431
1432 if (new_obj->transport) {
1433 new_obj->transport->init_sent_count++;
1434 asoc->init_last_sent_to = new_obj->transport;
1435 }
1436
1437 /* FIXME - Eventually come up with a cleaner way to
1438 * enabling COOKIE-ECHO + DATA bundling during
1439 * multihoming stale cookie scenarios, the following
1440 * command plays with asoc->peer.retran_path to
1441 * avoid the problem of sending the COOKIE-ECHO and
1442 * DATA in different paths, which could result
1443 * in the association being ABORTed if the DATA chunk
1444 * is processed first by the server. Checking the
1445 * init error counter simply causes this command
1446 * to be executed only during failed attempts of
1447 * association establishment.
1448 */
1449 if ((asoc->peer.retran_path !=
1450 asoc->peer.primary_path) &&
1451 (asoc->init_err_counter > 0)) {
1452 sctp_add_cmd_sf(commands,
1453 SCTP_CMD_FORCE_PRIM_RETRAN,
1454 SCTP_NULL());
1455 }
1456
1457 break;
1458
1459 case SCTP_CMD_GEN_SHUTDOWN:
1460 /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1461 * Reset error counts.
1462 */
1463 asoc->overall_error_count = 0;
1464
1465 /* Generate a SHUTDOWN chunk. */
1466 new_obj = sctp_make_shutdown(asoc, chunk);
1467 if (!new_obj)
1468 goto nomem;
1469 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1470 SCTP_CHUNK(new_obj));
1471 break;
1472
1473 case SCTP_CMD_CHUNK_ULP:
1474 /* Send a chunk to the sockets layer. */
1475 pr_debug("%s: sm_sideff: chunk_up:%p, ulpq:%p\n",
1476 __func__, cmd->obj.chunk, &asoc->ulpq);
1477
1478 asoc->stream.si->ulpevent_data(&asoc->ulpq,
1479 cmd->obj.chunk,
1480 GFP_ATOMIC);
1481 break;
1482
1483 case SCTP_CMD_EVENT_ULP:
1484 /* Send a notification to the sockets layer. */
1485 pr_debug("%s: sm_sideff: event_up:%p, ulpq:%p\n",
1486 __func__, cmd->obj.ulpevent, &asoc->ulpq);
1487
1488 asoc->stream.si->enqueue_event(&asoc->ulpq,
1489 cmd->obj.ulpevent);
1490 break;
1491
1492 case SCTP_CMD_REPLY:
1493 /* If an caller has not already corked, do cork. */
1494 if (!asoc->outqueue.cork) {
1495 sctp_outq_cork(&asoc->outqueue);
1496 local_cork = 1;
1497 }
1498 /* Send a chunk to our peer. */
1499 sctp_outq_tail(&asoc->outqueue, cmd->obj.chunk, gfp);
1500 break;
1501
1502 case SCTP_CMD_SEND_PKT:
1503 /* Send a full packet to our peer. */
1504 packet = cmd->obj.packet;
1505 sctp_packet_transmit(packet, gfp);
1506 sctp_ootb_pkt_free(packet);
1507 break;
1508
1509 case SCTP_CMD_T1_RETRAN:
1510 /* Mark a transport for retransmission. */
1511 sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1512 SCTP_RTXR_T1_RTX);
1513 break;
1514
1515 case SCTP_CMD_RETRAN:
1516 /* Mark a transport for retransmission. */
1517 sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1518 SCTP_RTXR_T3_RTX);
1519 break;
1520
1521 case SCTP_CMD_ECN_CE:
1522 /* Do delayed CE processing. */
1523 sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1524 break;
1525
1526 case SCTP_CMD_ECN_ECNE:
1527 /* Do delayed ECNE processing. */
1528 new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1529 chunk);
1530 if (new_obj)
1531 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1532 SCTP_CHUNK(new_obj));
1533 break;
1534
1535 case SCTP_CMD_ECN_CWR:
1536 /* Do delayed CWR processing. */
1537 sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1538 break;
1539
1540 case SCTP_CMD_SETUP_T2:
1541 sctp_cmd_setup_t2(commands, asoc, cmd->obj.chunk);
1542 break;
1543
1544 case SCTP_CMD_TIMER_START_ONCE:
1545 timer = &asoc->timers[cmd->obj.to];
1546
1547 if (timer_pending(timer))
1548 break;
1549 /* fall through */
1550
1551 case SCTP_CMD_TIMER_START:
1552 timer = &asoc->timers[cmd->obj.to];
1553 timeout = asoc->timeouts[cmd->obj.to];
1554 BUG_ON(!timeout);
1555
1556 timer->expires = jiffies + timeout;
1557 sctp_association_hold(asoc);
1558 add_timer(timer);
1559 break;
1560
1561 case SCTP_CMD_TIMER_RESTART:
1562 timer = &asoc->timers[cmd->obj.to];
1563 timeout = asoc->timeouts[cmd->obj.to];
1564 if (!mod_timer(timer, jiffies + timeout))
1565 sctp_association_hold(asoc);
1566 break;
1567
1568 case SCTP_CMD_TIMER_STOP:
1569 timer = &asoc->timers[cmd->obj.to];
1570 if (del_timer(timer))
1571 sctp_association_put(asoc);
1572 break;
1573
1574 case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1575 chunk = cmd->obj.chunk;
1576 t = sctp_assoc_choose_alter_transport(asoc,
1577 asoc->init_last_sent_to);
1578 asoc->init_last_sent_to = t;
1579 chunk->transport = t;
1580 t->init_sent_count++;
1581 /* Set the new transport as primary */
1582 sctp_assoc_set_primary(asoc, t);
1583 break;
1584
1585 case SCTP_CMD_INIT_RESTART:
1586 /* Do the needed accounting and updates
1587 * associated with restarting an initialization
1588 * timer. Only multiply the timeout by two if
1589 * all transports have been tried at the current
1590 * timeout.
1591 */
1592 sctp_cmd_t1_timer_update(asoc,
1593 SCTP_EVENT_TIMEOUT_T1_INIT,
1594 "INIT");
1595
1596 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1597 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1598 break;
1599
1600 case SCTP_CMD_COOKIEECHO_RESTART:
1601 /* Do the needed accounting and updates
1602 * associated with restarting an initialization
1603 * timer. Only multiply the timeout by two if
1604 * all transports have been tried at the current
1605 * timeout.
1606 */
1607 sctp_cmd_t1_timer_update(asoc,
1608 SCTP_EVENT_TIMEOUT_T1_COOKIE,
1609 "COOKIE");
1610
1611 /* If we've sent any data bundled with
1612 * COOKIE-ECHO we need to resend.
1613 */
1614 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1615 transports) {
1616 sctp_retransmit_mark(&asoc->outqueue, t,
1617 SCTP_RTXR_T1_RTX);
1618 }
1619
1620 sctp_add_cmd_sf(commands,
1621 SCTP_CMD_TIMER_RESTART,
1622 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1623 break;
1624
1625 case SCTP_CMD_INIT_FAILED:
1626 sctp_cmd_init_failed(commands, asoc, cmd->obj.u32);
1627 break;
1628
1629 case SCTP_CMD_ASSOC_FAILED:
1630 sctp_cmd_assoc_failed(commands, asoc, event_type,
1631 subtype, chunk, cmd->obj.u32);
1632 break;
1633
1634 case SCTP_CMD_INIT_COUNTER_INC:
1635 asoc->init_err_counter++;
1636 break;
1637
1638 case SCTP_CMD_INIT_COUNTER_RESET:
1639 asoc->init_err_counter = 0;
1640 asoc->init_cycle = 0;
1641 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1642 transports) {
1643 t->init_sent_count = 0;
1644 }
1645 break;
1646
1647 case SCTP_CMD_REPORT_DUP:
1648 sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1649 cmd->obj.u32);
1650 break;
1651
1652 case SCTP_CMD_REPORT_BAD_TAG:
1653 pr_debug("%s: vtag mismatch!\n", __func__);
1654 break;
1655
1656 case SCTP_CMD_STRIKE:
1657 /* Mark one strike against a transport. */
1658 sctp_do_8_2_transport_strike(commands, asoc,
1659 cmd->obj.transport, 0);
1660 break;
1661
1662 case SCTP_CMD_TRANSPORT_IDLE:
1663 t = cmd->obj.transport;
1664 sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
1665 break;
1666
1667 case SCTP_CMD_TRANSPORT_HB_SENT:
1668 t = cmd->obj.transport;
1669 sctp_do_8_2_transport_strike(commands, asoc,
1670 t, 1);
1671 t->hb_sent = 1;
1672 break;
1673
1674 case SCTP_CMD_TRANSPORT_ON:
1675 t = cmd->obj.transport;
1676 sctp_cmd_transport_on(commands, asoc, t, chunk);
1677 break;
1678
1679 case SCTP_CMD_HB_TIMERS_START:
1680 sctp_cmd_hb_timers_start(commands, asoc);
1681 break;
1682
1683 case SCTP_CMD_HB_TIMER_UPDATE:
1684 t = cmd->obj.transport;
1685 sctp_transport_reset_hb_timer(t);
1686 break;
1687
1688 case SCTP_CMD_HB_TIMERS_STOP:
1689 sctp_cmd_hb_timers_stop(commands, asoc);
1690 break;
1691
1692 case SCTP_CMD_REPORT_ERROR:
1693 error = cmd->obj.error;
1694 break;
1695
1696 case SCTP_CMD_PROCESS_CTSN:
1697 /* Dummy up a SACK for processing. */
1698 sackh.cum_tsn_ack = cmd->obj.be32;
1699 sackh.a_rwnd = htonl(asoc->peer.rwnd +
1700 asoc->outqueue.outstanding_bytes);
1701 sackh.num_gap_ack_blocks = 0;
1702 sackh.num_dup_tsns = 0;
1703 chunk->subh.sack_hdr = &sackh;
1704 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1705 SCTP_CHUNK(chunk));
1706 break;
1707
1708 case SCTP_CMD_DISCARD_PACKET:
1709 /* We need to discard the whole packet.
1710 * Uncork the queue since there might be
1711 * responses pending
1712 */
1713 chunk->pdiscard = 1;
1714 if (asoc) {
1715 sctp_outq_uncork(&asoc->outqueue, gfp);
1716 local_cork = 0;
1717 }
1718 break;
1719
1720 case SCTP_CMD_RTO_PENDING:
1721 t = cmd->obj.transport;
1722 t->rto_pending = 1;
1723 break;
1724
1725 case SCTP_CMD_PART_DELIVER:
1726 asoc->stream.si->start_pd(&asoc->ulpq, GFP_ATOMIC);
1727 break;
1728
1729 case SCTP_CMD_RENEGE:
1730 asoc->stream.si->renege_events(&asoc->ulpq,
1731 cmd->obj.chunk,
1732 GFP_ATOMIC);
1733 break;
1734
1735 case SCTP_CMD_SETUP_T4:
1736 sctp_cmd_setup_t4(commands, asoc, cmd->obj.chunk);
1737 break;
1738
1739 case SCTP_CMD_PROCESS_OPERR:
1740 sctp_cmd_process_operr(commands, asoc, chunk);
1741 break;
1742 case SCTP_CMD_CLEAR_INIT_TAG:
1743 asoc->peer.i.init_tag = 0;
1744 break;
1745 case SCTP_CMD_DEL_NON_PRIMARY:
1746 sctp_cmd_del_non_primary(asoc);
1747 break;
1748 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1749 sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1750 break;
1751 case SCTP_CMD_FORCE_PRIM_RETRAN:
1752 t = asoc->peer.retran_path;
1753 asoc->peer.retran_path = asoc->peer.primary_path;
1754 sctp_outq_uncork(&asoc->outqueue, gfp);
1755 local_cork = 0;
1756 asoc->peer.retran_path = t;
1757 break;
1758 case SCTP_CMD_SET_SK_ERR:
1759 sctp_cmd_set_sk_err(asoc, cmd->obj.error);
1760 break;
1761 case SCTP_CMD_ASSOC_CHANGE:
1762 sctp_cmd_assoc_change(commands, asoc,
1763 cmd->obj.u8);
1764 break;
1765 case SCTP_CMD_ADAPTATION_IND:
1766 sctp_cmd_adaptation_ind(commands, asoc);
1767 break;
1768 case SCTP_CMD_PEER_NO_AUTH:
1769 sctp_cmd_peer_no_auth(commands, asoc);
1770 break;
1771
1772 case SCTP_CMD_ASSOC_SHKEY:
1773 error = sctp_auth_asoc_init_active_key(asoc,
1774 GFP_ATOMIC);
1775 break;
1776 case SCTP_CMD_UPDATE_INITTAG:
1777 asoc->peer.i.init_tag = cmd->obj.u32;
1778 break;
1779 case SCTP_CMD_SEND_MSG:
1780 if (!asoc->outqueue.cork) {
1781 sctp_outq_cork(&asoc->outqueue);
1782 local_cork = 1;
1783 }
1784 sctp_cmd_send_msg(asoc, cmd->obj.msg, gfp);
1785 break;
1786 case SCTP_CMD_SEND_NEXT_ASCONF:
1787 sctp_cmd_send_asconf(asoc);
1788 break;
1789 case SCTP_CMD_PURGE_ASCONF_QUEUE:
1790 sctp_asconf_queue_teardown(asoc);
1791 break;
1792
1793 case SCTP_CMD_SET_ASOC:
1794 if (asoc && local_cork) {
1795 sctp_outq_uncork(&asoc->outqueue, gfp);
1796 local_cork = 0;
1797 }
1798 asoc = cmd->obj.asoc;
1799 break;
1800
1801 default:
1802 pr_warn("Impossible command: %u\n",
1803 cmd->verb);
1804 break;
1805 }
1806
1807 if (error)
1808 break;
1809 }
1810
1811out:
1812 /* If this is in response to a received chunk, wait until
1813 * we are done with the packet to open the queue so that we don't
1814 * send multiple packets in response to a single request.
1815 */
1816 if (asoc && SCTP_EVENT_T_CHUNK == event_type && chunk) {
1817 if (chunk->end_of_packet || chunk->singleton)
1818 sctp_outq_uncork(&asoc->outqueue, gfp);
1819 } else if (local_cork)
1820 sctp_outq_uncork(&asoc->outqueue, gfp);
1821
1822 if (sp->data_ready_signalled)
1823 sp->data_ready_signalled = 0;
1824
1825 return error;
1826nomem:
1827 error = -ENOMEM;
1828 goto out;
1829}
1830