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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// SPDX-License-Identifier: GPL-2.0-or-later
2/* SCTP kernel implementation
3 * (C) Copyright IBM Corp. 2001, 2004
4 * Copyright (c) 1999 Cisco, Inc.
5 * Copyright (c) 1999-2001 Motorola, Inc.
6 *
7 * This file is part of the SCTP kernel implementation
8 *
9 * These functions work with the state functions in sctp_sm_statefuns.c
10 * to implement that state operations. These functions implement the
11 * steps which require modifying existing data structures.
12 *
13 * Please send any bug reports or fixes you make to the
14 * email address(es):
15 * lksctp developers <linux-sctp@vger.kernel.org>
16 *
17 * Written or modified by:
18 * La Monte H.P. Yarroll <piggy@acm.org>
19 * Karl Knutson <karl@athena.chicago.il.us>
20 * Jon Grimm <jgrimm@austin.ibm.com>
21 * Hui Huang <hui.huang@nokia.com>
22 * Dajiang Zhang <dajiang.zhang@nokia.com>
23 * Daisy Chang <daisyc@us.ibm.com>
24 * Sridhar Samudrala <sri@us.ibm.com>
25 * Ardelle Fan <ardelle.fan@intel.com>
26 */
27
28#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
29
30#include <linux/skbuff.h>
31#include <linux/types.h>
32#include <linux/socket.h>
33#include <linux/ip.h>
34#include <linux/gfp.h>
35#include <net/sock.h>
36#include <net/sctp/sctp.h>
37#include <net/sctp/sm.h>
38#include <net/sctp/stream_sched.h>
39
40static int sctp_cmd_interpreter(enum sctp_event_type event_type,
41 union sctp_subtype subtype,
42 enum sctp_state state,
43 struct sctp_endpoint *ep,
44 struct sctp_association *asoc,
45 void *event_arg,
46 enum sctp_disposition status,
47 struct sctp_cmd_seq *commands,
48 gfp_t gfp);
49static int sctp_side_effects(enum sctp_event_type event_type,
50 union sctp_subtype subtype,
51 enum sctp_state state,
52 struct sctp_endpoint *ep,
53 struct sctp_association **asoc,
54 void *event_arg,
55 enum sctp_disposition status,
56 struct sctp_cmd_seq *commands,
57 gfp_t gfp);
58
59/********************************************************************
60 * Helper functions
61 ********************************************************************/
62
63/* A helper function for delayed processing of INET ECN CE bit. */
64static void sctp_do_ecn_ce_work(struct sctp_association *asoc,
65 __u32 lowest_tsn)
66{
67 /* Save the TSN away for comparison when we receive CWR */
68
69 asoc->last_ecne_tsn = lowest_tsn;
70 asoc->need_ecne = 1;
71}
72
73/* Helper function for delayed processing of SCTP ECNE chunk. */
74/* RFC 2960 Appendix A
75 *
76 * RFC 2481 details a specific bit for a sender to send in
77 * the header of its next outbound TCP segment to indicate to
78 * its peer that it has reduced its congestion window. This
79 * is termed the CWR bit. For SCTP the same indication is made
80 * by including the CWR chunk. This chunk contains one data
81 * element, i.e. the TSN number that was sent in the ECNE chunk.
82 * This element represents the lowest TSN number in the datagram
83 * that was originally marked with the CE bit.
84 */
85static struct sctp_chunk *sctp_do_ecn_ecne_work(struct sctp_association *asoc,
86 __u32 lowest_tsn,
87 struct sctp_chunk *chunk)
88{
89 struct sctp_chunk *repl;
90
91 /* Our previously transmitted packet ran into some congestion
92 * so we should take action by reducing cwnd and ssthresh
93 * and then ACK our peer that we we've done so by
94 * sending a CWR.
95 */
96
97 /* First, try to determine if we want to actually lower
98 * our cwnd variables. Only lower them if the ECNE looks more
99 * recent than the last response.
100 */
101 if (TSN_lt(asoc->last_cwr_tsn, lowest_tsn)) {
102 struct sctp_transport *transport;
103
104 /* Find which transport's congestion variables
105 * need to be adjusted.
106 */
107 transport = sctp_assoc_lookup_tsn(asoc, lowest_tsn);
108
109 /* Update the congestion variables. */
110 if (transport)
111 sctp_transport_lower_cwnd(transport,
112 SCTP_LOWER_CWND_ECNE);
113 asoc->last_cwr_tsn = lowest_tsn;
114 }
115
116 /* Always try to quiet the other end. In case of lost CWR,
117 * resend last_cwr_tsn.
118 */
119 repl = sctp_make_cwr(asoc, asoc->last_cwr_tsn, chunk);
120
121 /* If we run out of memory, it will look like a lost CWR. We'll
122 * get back in sync eventually.
123 */
124 return repl;
125}
126
127/* Helper function to do delayed processing of ECN CWR chunk. */
128static void sctp_do_ecn_cwr_work(struct sctp_association *asoc,
129 __u32 lowest_tsn)
130{
131 /* Turn off ECNE getting auto-prepended to every outgoing
132 * packet
133 */
134 asoc->need_ecne = 0;
135}
136
137/* Generate SACK if necessary. We call this at the end of a packet. */
138static int sctp_gen_sack(struct sctp_association *asoc, int force,
139 struct sctp_cmd_seq *commands)
140{
141 struct sctp_transport *trans = asoc->peer.last_data_from;
142 __u32 ctsn, max_tsn_seen;
143 struct sctp_chunk *sack;
144 int error = 0;
145
146 if (force ||
147 (!trans && (asoc->param_flags & SPP_SACKDELAY_DISABLE)) ||
148 (trans && (trans->param_flags & SPP_SACKDELAY_DISABLE)))
149 asoc->peer.sack_needed = 1;
150
151 ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
152 max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
153
154 /* From 12.2 Parameters necessary per association (i.e. the TCB):
155 *
156 * Ack State : This flag indicates if the next received packet
157 * : is to be responded to with a SACK. ...
158 * : When DATA chunks are out of order, SACK's
159 * : are not delayed (see Section 6).
160 *
161 * [This is actually not mentioned in Section 6, but we
162 * implement it here anyway. --piggy]
163 */
164 if (max_tsn_seen != ctsn)
165 asoc->peer.sack_needed = 1;
166
167 /* From 6.2 Acknowledgement on Reception of DATA Chunks:
168 *
169 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically,
170 * an acknowledgement SHOULD be generated for at least every
171 * second packet (not every second DATA chunk) received, and
172 * SHOULD be generated within 200 ms of the arrival of any
173 * unacknowledged DATA chunk. ...
174 */
175 if (!asoc->peer.sack_needed) {
176 asoc->peer.sack_cnt++;
177
178 /* Set the SACK delay timeout based on the
179 * SACK delay for the last transport
180 * data was received from, or the default
181 * for the association.
182 */
183 if (trans) {
184 /* We will need a SACK for the next packet. */
185 if (asoc->peer.sack_cnt >= trans->sackfreq - 1)
186 asoc->peer.sack_needed = 1;
187
188 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
189 trans->sackdelay;
190 } else {
191 /* We will need a SACK for the next packet. */
192 if (asoc->peer.sack_cnt >= asoc->sackfreq - 1)
193 asoc->peer.sack_needed = 1;
194
195 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
196 asoc->sackdelay;
197 }
198
199 /* Restart the SACK timer. */
200 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
201 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
202 } else {
203 __u32 old_a_rwnd = asoc->a_rwnd;
204
205 asoc->a_rwnd = asoc->rwnd;
206 sack = sctp_make_sack(asoc);
207 if (!sack) {
208 asoc->a_rwnd = old_a_rwnd;
209 goto nomem;
210 }
211
212 asoc->peer.sack_needed = 0;
213 asoc->peer.sack_cnt = 0;
214
215 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(sack));
216
217 /* Stop the SACK timer. */
218 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
219 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
220 }
221
222 return error;
223nomem:
224 error = -ENOMEM;
225 return error;
226}
227
228/* When the T3-RTX timer expires, it calls this function to create the
229 * relevant state machine event.
230 */
231void sctp_generate_t3_rtx_event(struct timer_list *t)
232{
233 struct sctp_transport *transport =
234 from_timer(transport, t, T3_rtx_timer);
235 struct sctp_association *asoc = transport->asoc;
236 struct sock *sk = asoc->base.sk;
237 struct net *net = sock_net(sk);
238 int error;
239
240 /* Check whether a task is in the sock. */
241
242 bh_lock_sock(sk);
243 if (sock_owned_by_user(sk)) {
244 pr_debug("%s: sock is busy\n", __func__);
245
246 /* Try again later. */
247 if (!mod_timer(&transport->T3_rtx_timer, jiffies + (HZ/20)))
248 sctp_transport_hold(transport);
249 goto out_unlock;
250 }
251
252 /* Run through the state machine. */
253 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
254 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX),
255 asoc->state,
256 asoc->ep, asoc,
257 transport, GFP_ATOMIC);
258
259 if (error)
260 sk->sk_err = -error;
261
262out_unlock:
263 bh_unlock_sock(sk);
264 sctp_transport_put(transport);
265}
266
267/* This is a sa interface for producing timeout events. It works
268 * for timeouts which use the association as their parameter.
269 */
270static void sctp_generate_timeout_event(struct sctp_association *asoc,
271 enum sctp_event_timeout timeout_type)
272{
273 struct sock *sk = asoc->base.sk;
274 struct net *net = sock_net(sk);
275 int error = 0;
276
277 bh_lock_sock(sk);
278 if (sock_owned_by_user(sk)) {
279 pr_debug("%s: sock is busy: timer %d\n", __func__,
280 timeout_type);
281
282 /* Try again later. */
283 if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20)))
284 sctp_association_hold(asoc);
285 goto out_unlock;
286 }
287
288 /* Is this association really dead and just waiting around for
289 * the timer to let go of the reference?
290 */
291 if (asoc->base.dead)
292 goto out_unlock;
293
294 /* Run through the state machine. */
295 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
296 SCTP_ST_TIMEOUT(timeout_type),
297 asoc->state, asoc->ep, asoc,
298 (void *)timeout_type, GFP_ATOMIC);
299
300 if (error)
301 sk->sk_err = -error;
302
303out_unlock:
304 bh_unlock_sock(sk);
305 sctp_association_put(asoc);
306}
307
308static void sctp_generate_t1_cookie_event(struct timer_list *t)
309{
310 struct sctp_association *asoc =
311 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_T1_COOKIE]);
312
313 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
314}
315
316static void sctp_generate_t1_init_event(struct timer_list *t)
317{
318 struct sctp_association *asoc =
319 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_T1_INIT]);
320
321 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
322}
323
324static void sctp_generate_t2_shutdown_event(struct timer_list *t)
325{
326 struct sctp_association *asoc =
327 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN]);
328
329 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
330}
331
332static void sctp_generate_t4_rto_event(struct timer_list *t)
333{
334 struct sctp_association *asoc =
335 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_T4_RTO]);
336
337 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
338}
339
340static void sctp_generate_t5_shutdown_guard_event(struct timer_list *t)
341{
342 struct sctp_association *asoc =
343 from_timer(asoc, t,
344 timers[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD]);
345
346 sctp_generate_timeout_event(asoc,
347 SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);
348
349} /* sctp_generate_t5_shutdown_guard_event() */
350
351static void sctp_generate_autoclose_event(struct timer_list *t)
352{
353 struct sctp_association *asoc =
354 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_AUTOCLOSE]);
355
356 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE);
357}
358
359/* Generate a heart beat event. If the sock is busy, reschedule. Make
360 * sure that the transport is still valid.
361 */
362void sctp_generate_heartbeat_event(struct timer_list *t)
363{
364 struct sctp_transport *transport = from_timer(transport, t, hb_timer);
365 struct sctp_association *asoc = transport->asoc;
366 struct sock *sk = asoc->base.sk;
367 struct net *net = sock_net(sk);
368 u32 elapsed, timeout;
369 int error = 0;
370
371 bh_lock_sock(sk);
372 if (sock_owned_by_user(sk)) {
373 pr_debug("%s: sock is busy\n", __func__);
374
375 /* Try again later. */
376 if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20)))
377 sctp_transport_hold(transport);
378 goto out_unlock;
379 }
380
381 /* Check if we should still send the heartbeat or reschedule */
382 elapsed = jiffies - transport->last_time_sent;
383 timeout = sctp_transport_timeout(transport);
384 if (elapsed < timeout) {
385 elapsed = timeout - elapsed;
386 if (!mod_timer(&transport->hb_timer, jiffies + elapsed))
387 sctp_transport_hold(transport);
388 goto out_unlock;
389 }
390
391 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
392 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
393 asoc->state, asoc->ep, asoc,
394 transport, GFP_ATOMIC);
395
396 if (error)
397 sk->sk_err = -error;
398
399out_unlock:
400 bh_unlock_sock(sk);
401 sctp_transport_put(transport);
402}
403
404/* Handle the timeout of the ICMP protocol unreachable timer. Trigger
405 * the correct state machine transition that will close the association.
406 */
407void sctp_generate_proto_unreach_event(struct timer_list *t)
408{
409 struct sctp_transport *transport =
410 from_timer(transport, t, proto_unreach_timer);
411 struct sctp_association *asoc = transport->asoc;
412 struct sock *sk = asoc->base.sk;
413 struct net *net = sock_net(sk);
414
415 bh_lock_sock(sk);
416 if (sock_owned_by_user(sk)) {
417 pr_debug("%s: sock is busy\n", __func__);
418
419 /* Try again later. */
420 if (!mod_timer(&transport->proto_unreach_timer,
421 jiffies + (HZ/20)))
422 sctp_association_hold(asoc);
423 goto out_unlock;
424 }
425
426 /* Is this structure just waiting around for us to actually
427 * get destroyed?
428 */
429 if (asoc->base.dead)
430 goto out_unlock;
431
432 sctp_do_sm(net, SCTP_EVENT_T_OTHER,
433 SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH),
434 asoc->state, asoc->ep, asoc, transport, GFP_ATOMIC);
435
436out_unlock:
437 bh_unlock_sock(sk);
438 sctp_association_put(asoc);
439}
440
441 /* Handle the timeout of the RE-CONFIG timer. */
442void sctp_generate_reconf_event(struct timer_list *t)
443{
444 struct sctp_transport *transport =
445 from_timer(transport, t, reconf_timer);
446 struct sctp_association *asoc = transport->asoc;
447 struct sock *sk = asoc->base.sk;
448 struct net *net = sock_net(sk);
449 int error = 0;
450
451 bh_lock_sock(sk);
452 if (sock_owned_by_user(sk)) {
453 pr_debug("%s: sock is busy\n", __func__);
454
455 /* Try again later. */
456 if (!mod_timer(&transport->reconf_timer, jiffies + (HZ / 20)))
457 sctp_transport_hold(transport);
458 goto out_unlock;
459 }
460
461 error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
462 SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_RECONF),
463 asoc->state, asoc->ep, asoc,
464 transport, GFP_ATOMIC);
465
466 if (error)
467 sk->sk_err = -error;
468
469out_unlock:
470 bh_unlock_sock(sk);
471 sctp_transport_put(transport);
472}
473
474/* Inject a SACK Timeout event into the state machine. */
475static void sctp_generate_sack_event(struct timer_list *t)
476{
477 struct sctp_association *asoc =
478 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_SACK]);
479
480 sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
481}
482
483sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
484 [SCTP_EVENT_TIMEOUT_NONE] = NULL,
485 [SCTP_EVENT_TIMEOUT_T1_COOKIE] = sctp_generate_t1_cookie_event,
486 [SCTP_EVENT_TIMEOUT_T1_INIT] = sctp_generate_t1_init_event,
487 [SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = sctp_generate_t2_shutdown_event,
488 [SCTP_EVENT_TIMEOUT_T3_RTX] = NULL,
489 [SCTP_EVENT_TIMEOUT_T4_RTO] = sctp_generate_t4_rto_event,
490 [SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD] =
491 sctp_generate_t5_shutdown_guard_event,
492 [SCTP_EVENT_TIMEOUT_HEARTBEAT] = NULL,
493 [SCTP_EVENT_TIMEOUT_RECONF] = NULL,
494 [SCTP_EVENT_TIMEOUT_SACK] = sctp_generate_sack_event,
495 [SCTP_EVENT_TIMEOUT_AUTOCLOSE] = sctp_generate_autoclose_event,
496};
497
498
499/* RFC 2960 8.2 Path Failure Detection
500 *
501 * When its peer endpoint is multi-homed, an endpoint should keep a
502 * error counter for each of the destination transport addresses of the
503 * peer endpoint.
504 *
505 * Each time the T3-rtx timer expires on any address, or when a
506 * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
507 * the error counter of that destination address will be incremented.
508 * When the value in the error counter exceeds the protocol parameter
509 * 'Path.Max.Retrans' of that destination address, the endpoint should
510 * mark the destination transport address as inactive, and a
511 * notification SHOULD be sent to the upper layer.
512 *
513 */
514static void sctp_do_8_2_transport_strike(struct sctp_cmd_seq *commands,
515 struct sctp_association *asoc,
516 struct sctp_transport *transport,
517 int is_hb)
518{
519 struct net *net = sock_net(asoc->base.sk);
520
521 /* The check for association's overall error counter exceeding the
522 * threshold is done in the state function.
523 */
524 /* We are here due to a timer expiration. If the timer was
525 * not a HEARTBEAT, then normal error tracking is done.
526 * If the timer was a heartbeat, we only increment error counts
527 * when we already have an outstanding HEARTBEAT that has not
528 * been acknowledged.
529 * Additionally, some tranport states inhibit error increments.
530 */
531 if (!is_hb) {
532 asoc->overall_error_count++;
533 if (transport->state != SCTP_INACTIVE)
534 transport->error_count++;
535 } else if (transport->hb_sent) {
536 if (transport->state != SCTP_UNCONFIRMED)
537 asoc->overall_error_count++;
538 if (transport->state != SCTP_INACTIVE)
539 transport->error_count++;
540 }
541
542 /* If the transport error count is greater than the pf_retrans
543 * threshold, and less than pathmaxrtx, and if the current state
544 * is SCTP_ACTIVE, then mark this transport as Partially Failed,
545 * see SCTP Quick Failover Draft, section 5.1
546 */
547 if (net->sctp.pf_enable &&
548 (transport->state == SCTP_ACTIVE) &&
549 (transport->error_count < transport->pathmaxrxt) &&
550 (transport->error_count > transport->pf_retrans)) {
551
552 sctp_assoc_control_transport(asoc, transport,
553 SCTP_TRANSPORT_PF,
554 0);
555
556 /* Update the hb timer to resend a heartbeat every rto */
557 sctp_transport_reset_hb_timer(transport);
558 }
559
560 if (transport->state != SCTP_INACTIVE &&
561 (transport->error_count > transport->pathmaxrxt)) {
562 pr_debug("%s: association:%p transport addr:%pISpc failed\n",
563 __func__, asoc, &transport->ipaddr.sa);
564
565 sctp_assoc_control_transport(asoc, transport,
566 SCTP_TRANSPORT_DOWN,
567 SCTP_FAILED_THRESHOLD);
568 }
569
570 /* E2) For the destination address for which the timer
571 * expires, set RTO <- RTO * 2 ("back off the timer"). The
572 * maximum value discussed in rule C7 above (RTO.max) may be
573 * used to provide an upper bound to this doubling operation.
574 *
575 * Special Case: the first HB doesn't trigger exponential backoff.
576 * The first unacknowledged HB triggers it. We do this with a flag
577 * that indicates that we have an outstanding HB.
578 */
579 if (!is_hb || transport->hb_sent) {
580 transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
581 sctp_max_rto(asoc, transport);
582 }
583}
584
585/* Worker routine to handle INIT command failure. */
586static void sctp_cmd_init_failed(struct sctp_cmd_seq *commands,
587 struct sctp_association *asoc,
588 unsigned int error)
589{
590 struct sctp_ulpevent *event;
591
592 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_CANT_STR_ASSOC,
593 (__u16)error, 0, 0, NULL,
594 GFP_ATOMIC);
595
596 if (event)
597 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
598 SCTP_ULPEVENT(event));
599
600 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
601 SCTP_STATE(SCTP_STATE_CLOSED));
602
603 /* SEND_FAILED sent later when cleaning up the association. */
604 asoc->outqueue.error = error;
605 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
606}
607
608/* Worker routine to handle SCTP_CMD_ASSOC_FAILED. */
609static void sctp_cmd_assoc_failed(struct sctp_cmd_seq *commands,
610 struct sctp_association *asoc,
611 enum sctp_event_type event_type,
612 union sctp_subtype subtype,
613 struct sctp_chunk *chunk,
614 unsigned int error)
615{
616 struct sctp_ulpevent *event;
617 struct sctp_chunk *abort;
618
619 /* Cancel any partial delivery in progress. */
620 asoc->stream.si->abort_pd(&asoc->ulpq, GFP_ATOMIC);
621
622 if (event_type == SCTP_EVENT_T_CHUNK && subtype.chunk == SCTP_CID_ABORT)
623 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
624 (__u16)error, 0, 0, chunk,
625 GFP_ATOMIC);
626 else
627 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
628 (__u16)error, 0, 0, NULL,
629 GFP_ATOMIC);
630 if (event)
631 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
632 SCTP_ULPEVENT(event));
633
634 if (asoc->overall_error_count >= asoc->max_retrans) {
635 abort = sctp_make_violation_max_retrans(asoc, chunk);
636 if (abort)
637 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
638 SCTP_CHUNK(abort));
639 }
640
641 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
642 SCTP_STATE(SCTP_STATE_CLOSED));
643
644 /* SEND_FAILED sent later when cleaning up the association. */
645 asoc->outqueue.error = error;
646 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
647}
648
649/* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
650 * inside the cookie. In reality, this is only used for INIT-ACK processing
651 * since all other cases use "temporary" associations and can do all
652 * their work in statefuns directly.
653 */
654static int sctp_cmd_process_init(struct sctp_cmd_seq *commands,
655 struct sctp_association *asoc,
656 struct sctp_chunk *chunk,
657 struct sctp_init_chunk *peer_init,
658 gfp_t gfp)
659{
660 int error;
661
662 /* We only process the init as a sideeffect in a single
663 * case. This is when we process the INIT-ACK. If we
664 * fail during INIT processing (due to malloc problems),
665 * just return the error and stop processing the stack.
666 */
667 if (!sctp_process_init(asoc, chunk, sctp_source(chunk), peer_init, gfp))
668 error = -ENOMEM;
669 else
670 error = 0;
671
672 return error;
673}
674
675/* Helper function to break out starting up of heartbeat timers. */
676static void sctp_cmd_hb_timers_start(struct sctp_cmd_seq *cmds,
677 struct sctp_association *asoc)
678{
679 struct sctp_transport *t;
680
681 /* Start a heartbeat timer for each transport on the association.
682 * hold a reference on the transport to make sure none of
683 * the needed data structures go away.
684 */
685 list_for_each_entry(t, &asoc->peer.transport_addr_list, transports)
686 sctp_transport_reset_hb_timer(t);
687}
688
689static void sctp_cmd_hb_timers_stop(struct sctp_cmd_seq *cmds,
690 struct sctp_association *asoc)
691{
692 struct sctp_transport *t;
693
694 /* Stop all heartbeat timers. */
695
696 list_for_each_entry(t, &asoc->peer.transport_addr_list,
697 transports) {
698 if (del_timer(&t->hb_timer))
699 sctp_transport_put(t);
700 }
701}
702
703/* Helper function to stop any pending T3-RTX timers */
704static void sctp_cmd_t3_rtx_timers_stop(struct sctp_cmd_seq *cmds,
705 struct sctp_association *asoc)
706{
707 struct sctp_transport *t;
708
709 list_for_each_entry(t, &asoc->peer.transport_addr_list,
710 transports) {
711 if (del_timer(&t->T3_rtx_timer))
712 sctp_transport_put(t);
713 }
714}
715
716
717/* Helper function to handle the reception of an HEARTBEAT ACK. */
718static void sctp_cmd_transport_on(struct sctp_cmd_seq *cmds,
719 struct sctp_association *asoc,
720 struct sctp_transport *t,
721 struct sctp_chunk *chunk)
722{
723 struct sctp_sender_hb_info *hbinfo;
724 int was_unconfirmed = 0;
725
726 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
727 * HEARTBEAT should clear the error counter of the destination
728 * transport address to which the HEARTBEAT was sent.
729 */
730 t->error_count = 0;
731
732 /*
733 * Although RFC4960 specifies that the overall error count must
734 * be cleared when a HEARTBEAT ACK is received, we make an
735 * exception while in SHUTDOWN PENDING. If the peer keeps its
736 * window shut forever, we may never be able to transmit our
737 * outstanding data and rely on the retransmission limit be reached
738 * to shutdown the association.
739 */
740 if (t->asoc->state < SCTP_STATE_SHUTDOWN_PENDING)
741 t->asoc->overall_error_count = 0;
742
743 /* Clear the hb_sent flag to signal that we had a good
744 * acknowledgement.
745 */
746 t->hb_sent = 0;
747
748 /* Mark the destination transport address as active if it is not so
749 * marked.
750 */
751 if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED)) {
752 was_unconfirmed = 1;
753 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
754 SCTP_HEARTBEAT_SUCCESS);
755 }
756
757 if (t->state == SCTP_PF)
758 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
759 SCTP_HEARTBEAT_SUCCESS);
760
761 /* HB-ACK was received for a the proper HB. Consider this
762 * forward progress.
763 */
764 if (t->dst)
765 sctp_transport_dst_confirm(t);
766
767 /* The receiver of the HEARTBEAT ACK should also perform an
768 * RTT measurement for that destination transport address
769 * using the time value carried in the HEARTBEAT ACK chunk.
770 * If the transport's rto_pending variable has been cleared,
771 * it was most likely due to a retransmit. However, we want
772 * to re-enable it to properly update the rto.
773 */
774 if (t->rto_pending == 0)
775 t->rto_pending = 1;
776
777 hbinfo = (struct sctp_sender_hb_info *)chunk->skb->data;
778 sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
779
780 /* Update the heartbeat timer. */
781 sctp_transport_reset_hb_timer(t);
782
783 if (was_unconfirmed && asoc->peer.transport_count == 1)
784 sctp_transport_immediate_rtx(t);
785}
786
787
788/* Helper function to process the process SACK command. */
789static int sctp_cmd_process_sack(struct sctp_cmd_seq *cmds,
790 struct sctp_association *asoc,
791 struct sctp_chunk *chunk)
792{
793 int err = 0;
794
795 if (sctp_outq_sack(&asoc->outqueue, chunk)) {
796 struct net *net = sock_net(asoc->base.sk);
797
798 /* There are no more TSNs awaiting SACK. */
799 err = sctp_do_sm(net, SCTP_EVENT_T_OTHER,
800 SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
801 asoc->state, asoc->ep, asoc, NULL,
802 GFP_ATOMIC);
803 }
804
805 return err;
806}
807
808/* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
809 * the transport for a shutdown chunk.
810 */
811static void sctp_cmd_setup_t2(struct sctp_cmd_seq *cmds,
812 struct sctp_association *asoc,
813 struct sctp_chunk *chunk)
814{
815 struct sctp_transport *t;
816
817 if (chunk->transport)
818 t = chunk->transport;
819 else {
820 t = sctp_assoc_choose_alter_transport(asoc,
821 asoc->shutdown_last_sent_to);
822 chunk->transport = t;
823 }
824 asoc->shutdown_last_sent_to = t;
825 asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
826}
827
828static void sctp_cmd_assoc_update(struct sctp_cmd_seq *cmds,
829 struct sctp_association *asoc,
830 struct sctp_association *new)
831{
832 struct net *net = sock_net(asoc->base.sk);
833 struct sctp_chunk *abort;
834
835 if (!sctp_assoc_update(asoc, new))
836 return;
837
838 abort = sctp_make_abort(asoc, NULL, sizeof(struct sctp_errhdr));
839 if (abort) {
840 sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0);
841 sctp_add_cmd_sf(cmds, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
842 }
843 sctp_add_cmd_sf(cmds, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNABORTED));
844 sctp_add_cmd_sf(cmds, SCTP_CMD_ASSOC_FAILED,
845 SCTP_PERR(SCTP_ERROR_RSRC_LOW));
846 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
847 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
848}
849
850/* Helper function to change the state of an association. */
851static void sctp_cmd_new_state(struct sctp_cmd_seq *cmds,
852 struct sctp_association *asoc,
853 enum sctp_state state)
854{
855 struct sock *sk = asoc->base.sk;
856
857 asoc->state = state;
858
859 pr_debug("%s: asoc:%p[%s]\n", __func__, asoc, sctp_state_tbl[state]);
860
861 if (sctp_style(sk, TCP)) {
862 /* Change the sk->sk_state of a TCP-style socket that has
863 * successfully completed a connect() call.
864 */
865 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
866 inet_sk_set_state(sk, SCTP_SS_ESTABLISHED);
867
868 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
869 if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
870 sctp_sstate(sk, ESTABLISHED)) {
871 inet_sk_set_state(sk, SCTP_SS_CLOSING);
872 sk->sk_shutdown |= RCV_SHUTDOWN;
873 }
874 }
875
876 if (sctp_state(asoc, COOKIE_WAIT)) {
877 /* Reset init timeouts since they may have been
878 * increased due to timer expirations.
879 */
880 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
881 asoc->rto_initial;
882 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
883 asoc->rto_initial;
884 }
885
886 if (sctp_state(asoc, ESTABLISHED)) {
887 kfree(asoc->peer.cookie);
888 asoc->peer.cookie = NULL;
889 }
890
891 if (sctp_state(asoc, ESTABLISHED) ||
892 sctp_state(asoc, CLOSED) ||
893 sctp_state(asoc, SHUTDOWN_RECEIVED)) {
894 /* Wake up any processes waiting in the asoc's wait queue in
895 * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
896 */
897 if (waitqueue_active(&asoc->wait))
898 wake_up_interruptible(&asoc->wait);
899
900 /* Wake up any processes waiting in the sk's sleep queue of
901 * a TCP-style or UDP-style peeled-off socket in
902 * sctp_wait_for_accept() or sctp_wait_for_packet().
903 * For a UDP-style socket, the waiters are woken up by the
904 * notifications.
905 */
906 if (!sctp_style(sk, UDP))
907 sk->sk_state_change(sk);
908 }
909
910 if (sctp_state(asoc, SHUTDOWN_PENDING) &&
911 !sctp_outq_is_empty(&asoc->outqueue))
912 sctp_outq_uncork(&asoc->outqueue, GFP_ATOMIC);
913}
914
915/* Helper function to delete an association. */
916static void sctp_cmd_delete_tcb(struct sctp_cmd_seq *cmds,
917 struct sctp_association *asoc)
918{
919 struct sock *sk = asoc->base.sk;
920
921 /* If it is a non-temporary association belonging to a TCP-style
922 * listening socket that is not closed, do not free it so that accept()
923 * can pick it up later.
924 */
925 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
926 (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
927 return;
928
929 sctp_association_free(asoc);
930}
931
932/*
933 * ADDIP Section 4.1 ASCONF Chunk Procedures
934 * A4) Start a T-4 RTO timer, using the RTO value of the selected
935 * destination address (we use active path instead of primary path just
936 * because primary path may be inactive.
937 */
938static void sctp_cmd_setup_t4(struct sctp_cmd_seq *cmds,
939 struct sctp_association *asoc,
940 struct sctp_chunk *chunk)
941{
942 struct sctp_transport *t;
943
944 t = sctp_assoc_choose_alter_transport(asoc, chunk->transport);
945 asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
946 chunk->transport = t;
947}
948
949/* Process an incoming Operation Error Chunk. */
950static void sctp_cmd_process_operr(struct sctp_cmd_seq *cmds,
951 struct sctp_association *asoc,
952 struct sctp_chunk *chunk)
953{
954 struct sctp_errhdr *err_hdr;
955 struct sctp_ulpevent *ev;
956
957 while (chunk->chunk_end > chunk->skb->data) {
958 err_hdr = (struct sctp_errhdr *)(chunk->skb->data);
959
960 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
961 GFP_ATOMIC);
962 if (!ev)
963 return;
964
965 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
966
967 switch (err_hdr->cause) {
968 case SCTP_ERROR_UNKNOWN_CHUNK:
969 {
970 struct sctp_chunkhdr *unk_chunk_hdr;
971
972 unk_chunk_hdr = (struct sctp_chunkhdr *)
973 err_hdr->variable;
974 switch (unk_chunk_hdr->type) {
975 /* ADDIP 4.1 A9) If the peer responds to an ASCONF with
976 * an ERROR chunk reporting that it did not recognized
977 * the ASCONF chunk type, the sender of the ASCONF MUST
978 * NOT send any further ASCONF chunks and MUST stop its
979 * T-4 timer.
980 */
981 case SCTP_CID_ASCONF:
982 if (asoc->peer.asconf_capable == 0)
983 break;
984
985 asoc->peer.asconf_capable = 0;
986 sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
987 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
988 break;
989 default:
990 break;
991 }
992 break;
993 }
994 default:
995 break;
996 }
997 }
998}
999
1000/* Helper function to remove the association non-primary peer
1001 * transports.
1002 */
1003static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
1004{
1005 struct sctp_transport *t;
1006 struct list_head *temp;
1007 struct list_head *pos;
1008
1009 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
1010 t = list_entry(pos, struct sctp_transport, transports);
1011 if (!sctp_cmp_addr_exact(&t->ipaddr,
1012 &asoc->peer.primary_addr)) {
1013 sctp_assoc_rm_peer(asoc, t);
1014 }
1015 }
1016}
1017
1018/* Helper function to set sk_err on a 1-1 style socket. */
1019static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
1020{
1021 struct sock *sk = asoc->base.sk;
1022
1023 if (!sctp_style(sk, UDP))
1024 sk->sk_err = error;
1025}
1026
1027/* Helper function to generate an association change event */
1028static void sctp_cmd_assoc_change(struct sctp_cmd_seq *commands,
1029 struct sctp_association *asoc,
1030 u8 state)
1031{
1032 struct sctp_ulpevent *ev;
1033
1034 ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0,
1035 asoc->c.sinit_num_ostreams,
1036 asoc->c.sinit_max_instreams,
1037 NULL, GFP_ATOMIC);
1038 if (ev)
1039 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
1040}
1041
1042static void sctp_cmd_peer_no_auth(struct sctp_cmd_seq *commands,
1043 struct sctp_association *asoc)
1044{
1045 struct sctp_ulpevent *ev;
1046
1047 ev = sctp_ulpevent_make_authkey(asoc, 0, SCTP_AUTH_NO_AUTH, GFP_ATOMIC);
1048 if (ev)
1049 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
1050}
1051
1052/* Helper function to generate an adaptation indication event */
1053static void sctp_cmd_adaptation_ind(struct sctp_cmd_seq *commands,
1054 struct sctp_association *asoc)
1055{
1056 struct sctp_ulpevent *ev;
1057
1058 ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
1059
1060 if (ev)
1061 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
1062}
1063
1064
1065static void sctp_cmd_t1_timer_update(struct sctp_association *asoc,
1066 enum sctp_event_timeout timer,
1067 char *name)
1068{
1069 struct sctp_transport *t;
1070
1071 t = asoc->init_last_sent_to;
1072 asoc->init_err_counter++;
1073
1074 if (t->init_sent_count > (asoc->init_cycle + 1)) {
1075 asoc->timeouts[timer] *= 2;
1076 if (asoc->timeouts[timer] > asoc->max_init_timeo) {
1077 asoc->timeouts[timer] = asoc->max_init_timeo;
1078 }
1079 asoc->init_cycle++;
1080
1081 pr_debug("%s: T1[%s] timeout adjustment init_err_counter:%d"
1082 " cycle:%d timeout:%ld\n", __func__, name,
1083 asoc->init_err_counter, asoc->init_cycle,
1084 asoc->timeouts[timer]);
1085 }
1086
1087}
1088
1089/* Send the whole message, chunk by chunk, to the outqueue.
1090 * This way the whole message is queued up and bundling if
1091 * encouraged for small fragments.
1092 */
1093static void sctp_cmd_send_msg(struct sctp_association *asoc,
1094 struct sctp_datamsg *msg, gfp_t gfp)
1095{
1096 struct sctp_chunk *chunk;
1097
1098 list_for_each_entry(chunk, &msg->chunks, frag_list)
1099 sctp_outq_tail(&asoc->outqueue, chunk, gfp);
1100
1101 asoc->outqueue.sched->enqueue(&asoc->outqueue, msg);
1102}
1103
1104
1105/* These three macros allow us to pull the debugging code out of the
1106 * main flow of sctp_do_sm() to keep attention focused on the real
1107 * functionality there.
1108 */
1109#define debug_pre_sfn() \
1110 pr_debug("%s[pre-fn]: ep:%p, %s, %s, asoc:%p[%s], %s\n", __func__, \
1111 ep, sctp_evttype_tbl[event_type], (*debug_fn)(subtype), \
1112 asoc, sctp_state_tbl[state], state_fn->name)
1113
1114#define debug_post_sfn() \
1115 pr_debug("%s[post-fn]: asoc:%p, status:%s\n", __func__, asoc, \
1116 sctp_status_tbl[status])
1117
1118#define debug_post_sfx() \
1119 pr_debug("%s[post-sfx]: error:%d, asoc:%p[%s]\n", __func__, error, \
1120 asoc, sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
1121 sctp_assoc2id(asoc))) ? asoc->state : SCTP_STATE_CLOSED])
1122
1123/*
1124 * This is the master state machine processing function.
1125 *
1126 * If you want to understand all of lksctp, this is a
1127 * good place to start.
1128 */
1129int sctp_do_sm(struct net *net, enum sctp_event_type event_type,
1130 union sctp_subtype subtype, enum sctp_state state,
1131 struct sctp_endpoint *ep, struct sctp_association *asoc,
1132 void *event_arg, gfp_t gfp)
1133{
1134 typedef const char *(printfn_t)(union sctp_subtype);
1135 static printfn_t *table[] = {
1136 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
1137 };
1138 printfn_t *debug_fn __attribute__ ((unused)) = table[event_type];
1139 const struct sctp_sm_table_entry *state_fn;
1140 struct sctp_cmd_seq commands;
1141 enum sctp_disposition status;
1142 int error = 0;
1143
1144 /* Look up the state function, run it, and then process the
1145 * side effects. These three steps are the heart of lksctp.
1146 */
1147 state_fn = sctp_sm_lookup_event(net, event_type, state, subtype);
1148
1149 sctp_init_cmd_seq(&commands);
1150
1151 debug_pre_sfn();
1152 status = state_fn->fn(net, ep, asoc, subtype, event_arg, &commands);
1153 debug_post_sfn();
1154
1155 error = sctp_side_effects(event_type, subtype, state,
1156 ep, &asoc, event_arg, status,
1157 &commands, gfp);
1158 debug_post_sfx();
1159
1160 return error;
1161}
1162
1163/*****************************************************************
1164 * This the master state function side effect processing function.
1165 *****************************************************************/
1166static int sctp_side_effects(enum sctp_event_type event_type,
1167 union sctp_subtype subtype,
1168 enum sctp_state state,
1169 struct sctp_endpoint *ep,
1170 struct sctp_association **asoc,
1171 void *event_arg,
1172 enum sctp_disposition status,
1173 struct sctp_cmd_seq *commands,
1174 gfp_t gfp)
1175{
1176 int error;
1177
1178 /* FIXME - Most of the dispositions left today would be categorized
1179 * as "exceptional" dispositions. For those dispositions, it
1180 * may not be proper to run through any of the commands at all.
1181 * For example, the command interpreter might be run only with
1182 * disposition SCTP_DISPOSITION_CONSUME.
1183 */
1184 if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
1185 ep, *asoc,
1186 event_arg, status,
1187 commands, gfp)))
1188 goto bail;
1189
1190 switch (status) {
1191 case SCTP_DISPOSITION_DISCARD:
1192 pr_debug("%s: ignored sctp protocol event - state:%d, "
1193 "event_type:%d, event_id:%d\n", __func__, state,
1194 event_type, subtype.chunk);
1195 break;
1196
1197 case SCTP_DISPOSITION_NOMEM:
1198 /* We ran out of memory, so we need to discard this
1199 * packet.
1200 */
1201 /* BUG--we should now recover some memory, probably by
1202 * reneging...
1203 */
1204 error = -ENOMEM;
1205 break;
1206
1207 case SCTP_DISPOSITION_DELETE_TCB:
1208 case SCTP_DISPOSITION_ABORT:
1209 /* This should now be a command. */
1210 *asoc = NULL;
1211 break;
1212
1213 case SCTP_DISPOSITION_CONSUME:
1214 /*
1215 * We should no longer have much work to do here as the
1216 * real work has been done as explicit commands above.
1217 */
1218 break;
1219
1220 case SCTP_DISPOSITION_VIOLATION:
1221 net_err_ratelimited("protocol violation state %d chunkid %d\n",
1222 state, subtype.chunk);
1223 break;
1224
1225 case SCTP_DISPOSITION_NOT_IMPL:
1226 pr_warn("unimplemented feature in state %d, event_type %d, event_id %d\n",
1227 state, event_type, subtype.chunk);
1228 break;
1229
1230 case SCTP_DISPOSITION_BUG:
1231 pr_err("bug in state %d, event_type %d, event_id %d\n",
1232 state, event_type, subtype.chunk);
1233 BUG();
1234 break;
1235
1236 default:
1237 pr_err("impossible disposition %d in state %d, event_type %d, event_id %d\n",
1238 status, state, event_type, subtype.chunk);
1239 BUG();
1240 break;
1241 }
1242
1243bail:
1244 return error;
1245}
1246
1247/********************************************************************
1248 * 2nd Level Abstractions
1249 ********************************************************************/
1250
1251/* This is the side-effect interpreter. */
1252static int sctp_cmd_interpreter(enum sctp_event_type event_type,
1253 union sctp_subtype subtype,
1254 enum sctp_state state,
1255 struct sctp_endpoint *ep,
1256 struct sctp_association *asoc,
1257 void *event_arg,
1258 enum sctp_disposition status,
1259 struct sctp_cmd_seq *commands,
1260 gfp_t gfp)
1261{
1262 struct sctp_sock *sp = sctp_sk(ep->base.sk);
1263 struct sctp_chunk *chunk = NULL, *new_obj;
1264 struct sctp_packet *packet;
1265 struct sctp_sackhdr sackh;
1266 struct timer_list *timer;
1267 struct sctp_transport *t;
1268 unsigned long timeout;
1269 struct sctp_cmd *cmd;
1270 int local_cork = 0;
1271 int error = 0;
1272 int force;
1273
1274 if (SCTP_EVENT_T_TIMEOUT != event_type)
1275 chunk = event_arg;
1276
1277 /* Note: This whole file is a huge candidate for rework.
1278 * For example, each command could either have its own handler, so
1279 * the loop would look like:
1280 * while (cmds)
1281 * cmd->handle(x, y, z)
1282 * --jgrimm
1283 */
1284 while (NULL != (cmd = sctp_next_cmd(commands))) {
1285 switch (cmd->verb) {
1286 case SCTP_CMD_NOP:
1287 /* Do nothing. */
1288 break;
1289
1290 case SCTP_CMD_NEW_ASOC:
1291 /* Register a new association. */
1292 if (local_cork) {
1293 sctp_outq_uncork(&asoc->outqueue, gfp);
1294 local_cork = 0;
1295 }
1296
1297 /* Register with the endpoint. */
1298 asoc = cmd->obj.asoc;
1299 BUG_ON(asoc->peer.primary_path == NULL);
1300 sctp_endpoint_add_asoc(ep, asoc);
1301 break;
1302
1303 case SCTP_CMD_UPDATE_ASSOC:
1304 sctp_cmd_assoc_update(commands, asoc, cmd->obj.asoc);
1305 break;
1306
1307 case SCTP_CMD_PURGE_OUTQUEUE:
1308 sctp_outq_teardown(&asoc->outqueue);
1309 break;
1310
1311 case SCTP_CMD_DELETE_TCB:
1312 if (local_cork) {
1313 sctp_outq_uncork(&asoc->outqueue, gfp);
1314 local_cork = 0;
1315 }
1316 /* Delete the current association. */
1317 sctp_cmd_delete_tcb(commands, asoc);
1318 asoc = NULL;
1319 break;
1320
1321 case SCTP_CMD_NEW_STATE:
1322 /* Enter a new state. */
1323 sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1324 break;
1325
1326 case SCTP_CMD_REPORT_TSN:
1327 /* Record the arrival of a TSN. */
1328 error = sctp_tsnmap_mark(&asoc->peer.tsn_map,
1329 cmd->obj.u32, NULL);
1330 break;
1331
1332 case SCTP_CMD_REPORT_FWDTSN:
1333 asoc->stream.si->report_ftsn(&asoc->ulpq, cmd->obj.u32);
1334 break;
1335
1336 case SCTP_CMD_PROCESS_FWDTSN:
1337 asoc->stream.si->handle_ftsn(&asoc->ulpq,
1338 cmd->obj.chunk);
1339 break;
1340
1341 case SCTP_CMD_GEN_SACK:
1342 /* Generate a Selective ACK.
1343 * The argument tells us whether to just count
1344 * the packet and MAYBE generate a SACK, or
1345 * force a SACK out.
1346 */
1347 force = cmd->obj.i32;
1348 error = sctp_gen_sack(asoc, force, commands);
1349 break;
1350
1351 case SCTP_CMD_PROCESS_SACK:
1352 /* Process an inbound SACK. */
1353 error = sctp_cmd_process_sack(commands, asoc,
1354 cmd->obj.chunk);
1355 break;
1356
1357 case SCTP_CMD_GEN_INIT_ACK:
1358 /* Generate an INIT ACK chunk. */
1359 new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1360 0);
1361 if (!new_obj)
1362 goto nomem;
1363
1364 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1365 SCTP_CHUNK(new_obj));
1366 break;
1367
1368 case SCTP_CMD_PEER_INIT:
1369 /* Process a unified INIT from the peer.
1370 * Note: Only used during INIT-ACK processing. If
1371 * there is an error just return to the outter
1372 * layer which will bail.
1373 */
1374 error = sctp_cmd_process_init(commands, asoc, chunk,
1375 cmd->obj.init, gfp);
1376 break;
1377
1378 case SCTP_CMD_GEN_COOKIE_ECHO:
1379 /* Generate a COOKIE ECHO chunk. */
1380 new_obj = sctp_make_cookie_echo(asoc, chunk);
1381 if (!new_obj) {
1382 if (cmd->obj.chunk)
1383 sctp_chunk_free(cmd->obj.chunk);
1384 goto nomem;
1385 }
1386 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1387 SCTP_CHUNK(new_obj));
1388
1389 /* If there is an ERROR chunk to be sent along with
1390 * the COOKIE_ECHO, send it, too.
1391 */
1392 if (cmd->obj.chunk)
1393 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1394 SCTP_CHUNK(cmd->obj.chunk));
1395
1396 if (new_obj->transport) {
1397 new_obj->transport->init_sent_count++;
1398 asoc->init_last_sent_to = new_obj->transport;
1399 }
1400
1401 /* FIXME - Eventually come up with a cleaner way to
1402 * enabling COOKIE-ECHO + DATA bundling during
1403 * multihoming stale cookie scenarios, the following
1404 * command plays with asoc->peer.retran_path to
1405 * avoid the problem of sending the COOKIE-ECHO and
1406 * DATA in different paths, which could result
1407 * in the association being ABORTed if the DATA chunk
1408 * is processed first by the server. Checking the
1409 * init error counter simply causes this command
1410 * to be executed only during failed attempts of
1411 * association establishment.
1412 */
1413 if ((asoc->peer.retran_path !=
1414 asoc->peer.primary_path) &&
1415 (asoc->init_err_counter > 0)) {
1416 sctp_add_cmd_sf(commands,
1417 SCTP_CMD_FORCE_PRIM_RETRAN,
1418 SCTP_NULL());
1419 }
1420
1421 break;
1422
1423 case SCTP_CMD_GEN_SHUTDOWN:
1424 /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1425 * Reset error counts.
1426 */
1427 asoc->overall_error_count = 0;
1428
1429 /* Generate a SHUTDOWN chunk. */
1430 new_obj = sctp_make_shutdown(asoc, chunk);
1431 if (!new_obj)
1432 goto nomem;
1433 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1434 SCTP_CHUNK(new_obj));
1435 break;
1436
1437 case SCTP_CMD_CHUNK_ULP:
1438 /* Send a chunk to the sockets layer. */
1439 pr_debug("%s: sm_sideff: chunk_up:%p, ulpq:%p\n",
1440 __func__, cmd->obj.chunk, &asoc->ulpq);
1441
1442 asoc->stream.si->ulpevent_data(&asoc->ulpq,
1443 cmd->obj.chunk,
1444 GFP_ATOMIC);
1445 break;
1446
1447 case SCTP_CMD_EVENT_ULP:
1448 /* Send a notification to the sockets layer. */
1449 pr_debug("%s: sm_sideff: event_up:%p, ulpq:%p\n",
1450 __func__, cmd->obj.ulpevent, &asoc->ulpq);
1451
1452 asoc->stream.si->enqueue_event(&asoc->ulpq,
1453 cmd->obj.ulpevent);
1454 break;
1455
1456 case SCTP_CMD_REPLY:
1457 /* If an caller has not already corked, do cork. */
1458 if (!asoc->outqueue.cork) {
1459 sctp_outq_cork(&asoc->outqueue);
1460 local_cork = 1;
1461 }
1462 /* Send a chunk to our peer. */
1463 sctp_outq_tail(&asoc->outqueue, cmd->obj.chunk, gfp);
1464 break;
1465
1466 case SCTP_CMD_SEND_PKT:
1467 /* Send a full packet to our peer. */
1468 packet = cmd->obj.packet;
1469 sctp_packet_transmit(packet, gfp);
1470 sctp_ootb_pkt_free(packet);
1471 break;
1472
1473 case SCTP_CMD_T1_RETRAN:
1474 /* Mark a transport for retransmission. */
1475 sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1476 SCTP_RTXR_T1_RTX);
1477 break;
1478
1479 case SCTP_CMD_RETRAN:
1480 /* Mark a transport for retransmission. */
1481 sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1482 SCTP_RTXR_T3_RTX);
1483 break;
1484
1485 case SCTP_CMD_ECN_CE:
1486 /* Do delayed CE processing. */
1487 sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1488 break;
1489
1490 case SCTP_CMD_ECN_ECNE:
1491 /* Do delayed ECNE processing. */
1492 new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1493 chunk);
1494 if (new_obj)
1495 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1496 SCTP_CHUNK(new_obj));
1497 break;
1498
1499 case SCTP_CMD_ECN_CWR:
1500 /* Do delayed CWR processing. */
1501 sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1502 break;
1503
1504 case SCTP_CMD_SETUP_T2:
1505 sctp_cmd_setup_t2(commands, asoc, cmd->obj.chunk);
1506 break;
1507
1508 case SCTP_CMD_TIMER_START_ONCE:
1509 timer = &asoc->timers[cmd->obj.to];
1510
1511 if (timer_pending(timer))
1512 break;
1513 /* fall through */
1514
1515 case SCTP_CMD_TIMER_START:
1516 timer = &asoc->timers[cmd->obj.to];
1517 timeout = asoc->timeouts[cmd->obj.to];
1518 BUG_ON(!timeout);
1519
1520 timer->expires = jiffies + timeout;
1521 sctp_association_hold(asoc);
1522 add_timer(timer);
1523 break;
1524
1525 case SCTP_CMD_TIMER_RESTART:
1526 timer = &asoc->timers[cmd->obj.to];
1527 timeout = asoc->timeouts[cmd->obj.to];
1528 if (!mod_timer(timer, jiffies + timeout))
1529 sctp_association_hold(asoc);
1530 break;
1531
1532 case SCTP_CMD_TIMER_STOP:
1533 timer = &asoc->timers[cmd->obj.to];
1534 if (del_timer(timer))
1535 sctp_association_put(asoc);
1536 break;
1537
1538 case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1539 chunk = cmd->obj.chunk;
1540 t = sctp_assoc_choose_alter_transport(asoc,
1541 asoc->init_last_sent_to);
1542 asoc->init_last_sent_to = t;
1543 chunk->transport = t;
1544 t->init_sent_count++;
1545 /* Set the new transport as primary */
1546 sctp_assoc_set_primary(asoc, t);
1547 break;
1548
1549 case SCTP_CMD_INIT_RESTART:
1550 /* Do the needed accounting and updates
1551 * associated with restarting an initialization
1552 * timer. Only multiply the timeout by two if
1553 * all transports have been tried at the current
1554 * timeout.
1555 */
1556 sctp_cmd_t1_timer_update(asoc,
1557 SCTP_EVENT_TIMEOUT_T1_INIT,
1558 "INIT");
1559
1560 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1561 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1562 break;
1563
1564 case SCTP_CMD_COOKIEECHO_RESTART:
1565 /* Do the needed accounting and updates
1566 * associated with restarting an initialization
1567 * timer. Only multiply the timeout by two if
1568 * all transports have been tried at the current
1569 * timeout.
1570 */
1571 sctp_cmd_t1_timer_update(asoc,
1572 SCTP_EVENT_TIMEOUT_T1_COOKIE,
1573 "COOKIE");
1574
1575 /* If we've sent any data bundled with
1576 * COOKIE-ECHO we need to resend.
1577 */
1578 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1579 transports) {
1580 sctp_retransmit_mark(&asoc->outqueue, t,
1581 SCTP_RTXR_T1_RTX);
1582 }
1583
1584 sctp_add_cmd_sf(commands,
1585 SCTP_CMD_TIMER_RESTART,
1586 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1587 break;
1588
1589 case SCTP_CMD_INIT_FAILED:
1590 sctp_cmd_init_failed(commands, asoc, cmd->obj.u32);
1591 break;
1592
1593 case SCTP_CMD_ASSOC_FAILED:
1594 sctp_cmd_assoc_failed(commands, asoc, event_type,
1595 subtype, chunk, cmd->obj.u32);
1596 break;
1597
1598 case SCTP_CMD_INIT_COUNTER_INC:
1599 asoc->init_err_counter++;
1600 break;
1601
1602 case SCTP_CMD_INIT_COUNTER_RESET:
1603 asoc->init_err_counter = 0;
1604 asoc->init_cycle = 0;
1605 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1606 transports) {
1607 t->init_sent_count = 0;
1608 }
1609 break;
1610
1611 case SCTP_CMD_REPORT_DUP:
1612 sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1613 cmd->obj.u32);
1614 break;
1615
1616 case SCTP_CMD_REPORT_BAD_TAG:
1617 pr_debug("%s: vtag mismatch!\n", __func__);
1618 break;
1619
1620 case SCTP_CMD_STRIKE:
1621 /* Mark one strike against a transport. */
1622 sctp_do_8_2_transport_strike(commands, asoc,
1623 cmd->obj.transport, 0);
1624 break;
1625
1626 case SCTP_CMD_TRANSPORT_IDLE:
1627 t = cmd->obj.transport;
1628 sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
1629 break;
1630
1631 case SCTP_CMD_TRANSPORT_HB_SENT:
1632 t = cmd->obj.transport;
1633 sctp_do_8_2_transport_strike(commands, asoc,
1634 t, 1);
1635 t->hb_sent = 1;
1636 break;
1637
1638 case SCTP_CMD_TRANSPORT_ON:
1639 t = cmd->obj.transport;
1640 sctp_cmd_transport_on(commands, asoc, t, chunk);
1641 break;
1642
1643 case SCTP_CMD_HB_TIMERS_START:
1644 sctp_cmd_hb_timers_start(commands, asoc);
1645 break;
1646
1647 case SCTP_CMD_HB_TIMER_UPDATE:
1648 t = cmd->obj.transport;
1649 sctp_transport_reset_hb_timer(t);
1650 break;
1651
1652 case SCTP_CMD_HB_TIMERS_STOP:
1653 sctp_cmd_hb_timers_stop(commands, asoc);
1654 break;
1655
1656 case SCTP_CMD_REPORT_ERROR:
1657 error = cmd->obj.error;
1658 break;
1659
1660 case SCTP_CMD_PROCESS_CTSN:
1661 /* Dummy up a SACK for processing. */
1662 sackh.cum_tsn_ack = cmd->obj.be32;
1663 sackh.a_rwnd = htonl(asoc->peer.rwnd +
1664 asoc->outqueue.outstanding_bytes);
1665 sackh.num_gap_ack_blocks = 0;
1666 sackh.num_dup_tsns = 0;
1667 chunk->subh.sack_hdr = &sackh;
1668 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1669 SCTP_CHUNK(chunk));
1670 break;
1671
1672 case SCTP_CMD_DISCARD_PACKET:
1673 /* We need to discard the whole packet.
1674 * Uncork the queue since there might be
1675 * responses pending
1676 */
1677 chunk->pdiscard = 1;
1678 if (asoc) {
1679 sctp_outq_uncork(&asoc->outqueue, gfp);
1680 local_cork = 0;
1681 }
1682 break;
1683
1684 case SCTP_CMD_RTO_PENDING:
1685 t = cmd->obj.transport;
1686 t->rto_pending = 1;
1687 break;
1688
1689 case SCTP_CMD_PART_DELIVER:
1690 asoc->stream.si->start_pd(&asoc->ulpq, GFP_ATOMIC);
1691 break;
1692
1693 case SCTP_CMD_RENEGE:
1694 asoc->stream.si->renege_events(&asoc->ulpq,
1695 cmd->obj.chunk,
1696 GFP_ATOMIC);
1697 break;
1698
1699 case SCTP_CMD_SETUP_T4:
1700 sctp_cmd_setup_t4(commands, asoc, cmd->obj.chunk);
1701 break;
1702
1703 case SCTP_CMD_PROCESS_OPERR:
1704 sctp_cmd_process_operr(commands, asoc, chunk);
1705 break;
1706 case SCTP_CMD_CLEAR_INIT_TAG:
1707 asoc->peer.i.init_tag = 0;
1708 break;
1709 case SCTP_CMD_DEL_NON_PRIMARY:
1710 sctp_cmd_del_non_primary(asoc);
1711 break;
1712 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1713 sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1714 break;
1715 case SCTP_CMD_FORCE_PRIM_RETRAN:
1716 t = asoc->peer.retran_path;
1717 asoc->peer.retran_path = asoc->peer.primary_path;
1718 sctp_outq_uncork(&asoc->outqueue, gfp);
1719 local_cork = 0;
1720 asoc->peer.retran_path = t;
1721 break;
1722 case SCTP_CMD_SET_SK_ERR:
1723 sctp_cmd_set_sk_err(asoc, cmd->obj.error);
1724 break;
1725 case SCTP_CMD_ASSOC_CHANGE:
1726 sctp_cmd_assoc_change(commands, asoc,
1727 cmd->obj.u8);
1728 break;
1729 case SCTP_CMD_ADAPTATION_IND:
1730 sctp_cmd_adaptation_ind(commands, asoc);
1731 break;
1732 case SCTP_CMD_PEER_NO_AUTH:
1733 sctp_cmd_peer_no_auth(commands, asoc);
1734 break;
1735
1736 case SCTP_CMD_ASSOC_SHKEY:
1737 error = sctp_auth_asoc_init_active_key(asoc,
1738 GFP_ATOMIC);
1739 break;
1740 case SCTP_CMD_UPDATE_INITTAG:
1741 asoc->peer.i.init_tag = cmd->obj.u32;
1742 break;
1743 case SCTP_CMD_SEND_MSG:
1744 if (!asoc->outqueue.cork) {
1745 sctp_outq_cork(&asoc->outqueue);
1746 local_cork = 1;
1747 }
1748 sctp_cmd_send_msg(asoc, cmd->obj.msg, gfp);
1749 break;
1750 case SCTP_CMD_PURGE_ASCONF_QUEUE:
1751 sctp_asconf_queue_teardown(asoc);
1752 break;
1753
1754 case SCTP_CMD_SET_ASOC:
1755 if (asoc && local_cork) {
1756 sctp_outq_uncork(&asoc->outqueue, gfp);
1757 local_cork = 0;
1758 }
1759 asoc = cmd->obj.asoc;
1760 break;
1761
1762 default:
1763 pr_warn("Impossible command: %u\n",
1764 cmd->verb);
1765 break;
1766 }
1767
1768 if (error)
1769 break;
1770 }
1771
1772out:
1773 /* If this is in response to a received chunk, wait until
1774 * we are done with the packet to open the queue so that we don't
1775 * send multiple packets in response to a single request.
1776 */
1777 if (asoc && SCTP_EVENT_T_CHUNK == event_type && chunk) {
1778 if (chunk->end_of_packet || chunk->singleton)
1779 sctp_outq_uncork(&asoc->outqueue, gfp);
1780 } else if (local_cork)
1781 sctp_outq_uncork(&asoc->outqueue, gfp);
1782
1783 if (sp->data_ready_signalled)
1784 sp->data_ready_signalled = 0;
1785
1786 return error;
1787nomem:
1788 error = -ENOMEM;
1789 goto out;
1790}