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spi-topcliff-pch: Fix issue for transmitting over 4KByte
[zen-stable.git] / net / sctp / sm_sideeffect.c
blob1ff51c9d18d5d5ca925da9bd24544fe46014ad7b
1 /* SCTP kernel implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 *
6 * This file is part of the SCTP kernel implementation
7 *
8 * These functions work with the state functions in sctp_sm_statefuns.c
9 * to implement that state operations. These functions implement the
10 * steps which require modifying existing data structures.
11 *
12 * This SCTP implementation is free software;
13 * you can redistribute it and/or modify it under the terms of
14 * the GNU General Public License as published by
15 * the Free Software Foundation; either version 2, or (at your option)
16 * any later version.
17 *
18 * This SCTP implementation is distributed in the hope that it
19 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
20 * ************************
21 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
22 * See the GNU General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License
25 * along with GNU CC; see the file COPYING. If not, write to
26 * the Free Software Foundation, 59 Temple Place - Suite 330,
27 * Boston, MA 02111-1307, USA.
28 *
29 * Please send any bug reports or fixes you make to the
30 * email address(es):
31 * lksctp developers <lksctp-developers@lists.sourceforge.net>
32 *
33 * Or submit a bug report through the following website:
34 * http://www.sf.net/projects/lksctp
35 *
36 * Written or modified by:
37 * La Monte H.P. Yarroll <piggy@acm.org>
38 * Karl Knutson <karl@athena.chicago.il.us>
39 * Jon Grimm <jgrimm@austin.ibm.com>
40 * Hui Huang <hui.huang@nokia.com>
41 * Dajiang Zhang <dajiang.zhang@nokia.com>
42 * Daisy Chang <daisyc@us.ibm.com>
43 * Sridhar Samudrala <sri@us.ibm.com>
44 * Ardelle Fan <ardelle.fan@intel.com>
45 *
46 * Any bugs reported given to us we will try to fix... any fixes shared will
47 * be incorporated into the next SCTP release.
48 */
49
50 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
51
52 #include <linux/skbuff.h>
53 #include <linux/types.h>
54 #include <linux/socket.h>
55 #include <linux/ip.h>
56 #include <linux/gfp.h>
57 #include <net/sock.h>
58 #include <net/sctp/sctp.h>
59 #include <net/sctp/sm.h>
60
61 static int sctp_cmd_interpreter(sctp_event_t event_type,
62 sctp_subtype_t subtype,
63 sctp_state_t state,
64 struct sctp_endpoint *ep,
65 struct sctp_association *asoc,
66 void *event_arg,
67 sctp_disposition_t status,
68 sctp_cmd_seq_t *commands,
69 gfp_t gfp);
70 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
71 sctp_state_t state,
72 struct sctp_endpoint *ep,
73 struct sctp_association *asoc,
74 void *event_arg,
75 sctp_disposition_t status,
76 sctp_cmd_seq_t *commands,
77 gfp_t gfp);
78
79 /********************************************************************
80 * Helper functions
81 ********************************************************************/
82
83 /* A helper function for delayed processing of INET ECN CE bit. */
84 static 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 */
105 static 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. */
148 static 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. */
158 static 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;
239 nomem:
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 */
247 void 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
281 out_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 */
289 static 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
321 out_unlock:
322 sctp_bh_unlock_sock(asoc->base.sk);
323 sctp_association_put(asoc);
324 }
325
326 static 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
332 static 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
338 static 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
344 static 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
350 static 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
358 static 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 */
367 void 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
397 out_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 */
405 void sctp_generate_proto_unreach_event(unsigned long data)
406 {
407 struct sctp_transport *transport = (struct sctp_transport *) data;
408 struct sctp_association *asoc = transport->asoc;
409
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
431 out_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. */
438 static 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
444 sctp_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 */
473 static 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. */
525 static 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. */
548 static 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 */
585 static 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. */
607 static 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
623 static 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 */
638 static 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. */
654 static 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. */
663 static 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 int was_unconfirmed = 0;
670
671 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
672 * HEARTBEAT should clear the error counter of the destination
673 * transport address to which the HEARTBEAT was sent.
674 */
675 t->error_count = 0;
676
677 /*
678 * Although RFC4960 specifies that the overall error count must
679 * be cleared when a HEARTBEAT ACK is received, we make an
680 * exception while in SHUTDOWN PENDING. If the peer keeps its
681 * window shut forever, we may never be able to transmit our
682 * outstanding data and rely on the retransmission limit be reached
683 * to shutdown the association.
684 */
685 if (t->asoc->state != SCTP_STATE_SHUTDOWN_PENDING)
686 t->asoc->overall_error_count = 0;
687
688 /* Clear the hb_sent flag to signal that we had a good
689 * acknowledgement.
690 */
691 t->hb_sent = 0;
692
693 /* Mark the destination transport address as active if it is not so
694 * marked.
695 */
696 if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED)) {
697 was_unconfirmed = 1;
698 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
699 SCTP_HEARTBEAT_SUCCESS);
700 }
701
702 /* The receiver of the HEARTBEAT ACK should also perform an
703 * RTT measurement for that destination transport address
704 * using the time value carried in the HEARTBEAT ACK chunk.
705 * If the transport's rto_pending variable has been cleared,
706 * it was most likely due to a retransmit. However, we want
707 * to re-enable it to properly update the rto.
708 */
709 if (t->rto_pending == 0)
710 t->rto_pending = 1;
711
712 hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
713 sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
714
715 /* Update the heartbeat timer. */
716 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
717 sctp_transport_hold(t);
718
719 if (was_unconfirmed && asoc->peer.transport_count == 1)
720 sctp_transport_immediate_rtx(t);
721 }
722
723
724 /* Helper function to process the process SACK command. */
725 static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds,
726 struct sctp_association *asoc,
727 struct sctp_sackhdr *sackh)
728 {
729 int err = 0;
730
731 if (sctp_outq_sack(&asoc->outqueue, sackh)) {
732 /* There are no more TSNs awaiting SACK. */
733 err = sctp_do_sm(SCTP_EVENT_T_OTHER,
734 SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
735 asoc->state, asoc->ep, asoc, NULL,
736 GFP_ATOMIC);
737 }
738
739 return err;
740 }
741
742 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
743 * the transport for a shutdown chunk.
744 */
745 static void sctp_cmd_setup_t2(sctp_cmd_seq_t *cmds,
746 struct sctp_association *asoc,
747 struct sctp_chunk *chunk)
748 {
749 struct sctp_transport *t;
750
751 if (chunk->transport)
752 t = chunk->transport;
753 else {
754 t = sctp_assoc_choose_alter_transport(asoc,
755 asoc->shutdown_last_sent_to);
756 chunk->transport = t;
757 }
758 asoc->shutdown_last_sent_to = t;
759 asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
760 }
761
762 /* Helper function to change the state of an association. */
763 static void sctp_cmd_new_state(sctp_cmd_seq_t *cmds,
764 struct sctp_association *asoc,
765 sctp_state_t state)
766 {
767 struct sock *sk = asoc->base.sk;
768
769 asoc->state = state;
770
771 SCTP_DEBUG_PRINTK("sctp_cmd_new_state: asoc %p[%s]\n",
772 asoc, sctp_state_tbl[state]);
773
774 if (sctp_style(sk, TCP)) {
775 /* Change the sk->sk_state of a TCP-style socket that has
776 * successfully completed a connect() call.
777 */
778 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
779 sk->sk_state = SCTP_SS_ESTABLISHED;
780
781 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
782 if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
783 sctp_sstate(sk, ESTABLISHED))
784 sk->sk_shutdown |= RCV_SHUTDOWN;
785 }
786
787 if (sctp_state(asoc, COOKIE_WAIT)) {
788 /* Reset init timeouts since they may have been
789 * increased due to timer expirations.
790 */
791 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
792 asoc->rto_initial;
793 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
794 asoc->rto_initial;
795 }
796
797 if (sctp_state(asoc, ESTABLISHED) ||
798 sctp_state(asoc, CLOSED) ||
799 sctp_state(asoc, SHUTDOWN_RECEIVED)) {
800 /* Wake up any processes waiting in the asoc's wait queue in
801 * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
802 */
803 if (waitqueue_active(&asoc->wait))
804 wake_up_interruptible(&asoc->wait);
805
806 /* Wake up any processes waiting in the sk's sleep queue of
807 * a TCP-style or UDP-style peeled-off socket in
808 * sctp_wait_for_accept() or sctp_wait_for_packet().
809 * For a UDP-style socket, the waiters are woken up by the
810 * notifications.
811 */
812 if (!sctp_style(sk, UDP))
813 sk->sk_state_change(sk);
814 }
815 }
816
817 /* Helper function to delete an association. */
818 static void sctp_cmd_delete_tcb(sctp_cmd_seq_t *cmds,
819 struct sctp_association *asoc)
820 {
821 struct sock *sk = asoc->base.sk;
822
823 /* If it is a non-temporary association belonging to a TCP-style
824 * listening socket that is not closed, do not free it so that accept()
825 * can pick it up later.
826 */
827 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
828 (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
829 return;
830
831 sctp_unhash_established(asoc);
832 sctp_association_free(asoc);
833 }
834
835 /*
836 * ADDIP Section 4.1 ASCONF Chunk Procedures
837 * A4) Start a T-4 RTO timer, using the RTO value of the selected
838 * destination address (we use active path instead of primary path just
839 * because primary path may be inactive.
840 */
841 static void sctp_cmd_setup_t4(sctp_cmd_seq_t *cmds,
842 struct sctp_association *asoc,
843 struct sctp_chunk *chunk)
844 {
845 struct sctp_transport *t;
846
847 t = sctp_assoc_choose_alter_transport(asoc, chunk->transport);
848 asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
849 chunk->transport = t;
850 }
851
852 /* Process an incoming Operation Error Chunk. */
853 static void sctp_cmd_process_operr(sctp_cmd_seq_t *cmds,
854 struct sctp_association *asoc,
855 struct sctp_chunk *chunk)
856 {
857 struct sctp_errhdr *err_hdr;
858 struct sctp_ulpevent *ev;
859
860 while (chunk->chunk_end > chunk->skb->data) {
861 err_hdr = (struct sctp_errhdr *)(chunk->skb->data);
862
863 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
864 GFP_ATOMIC);
865 if (!ev)
866 return;
867
868 sctp_ulpq_tail_event(&asoc->ulpq, ev);
869
870 switch (err_hdr->cause) {
871 case SCTP_ERROR_UNKNOWN_CHUNK:
872 {
873 sctp_chunkhdr_t *unk_chunk_hdr;
874
875 unk_chunk_hdr = (sctp_chunkhdr_t *)err_hdr->variable;
876 switch (unk_chunk_hdr->type) {
877 /* ADDIP 4.1 A9) If the peer responds to an ASCONF with
878 * an ERROR chunk reporting that it did not recognized
879 * the ASCONF chunk type, the sender of the ASCONF MUST
880 * NOT send any further ASCONF chunks and MUST stop its
881 * T-4 timer.
882 */
883 case SCTP_CID_ASCONF:
884 if (asoc->peer.asconf_capable == 0)
885 break;
886
887 asoc->peer.asconf_capable = 0;
888 sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
889 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
890 break;
891 default:
892 break;
893 }
894 break;
895 }
896 default:
897 break;
898 }
899 }
900 }
901
902 /* Process variable FWDTSN chunk information. */
903 static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq,
904 struct sctp_chunk *chunk)
905 {
906 struct sctp_fwdtsn_skip *skip;
907 /* Walk through all the skipped SSNs */
908 sctp_walk_fwdtsn(skip, chunk) {
909 sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
910 }
911 }
912
913 /* Helper function to remove the association non-primary peer
914 * transports.
915 */
916 static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
917 {
918 struct sctp_transport *t;
919 struct list_head *pos;
920 struct list_head *temp;
921
922 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
923 t = list_entry(pos, struct sctp_transport, transports);
924 if (!sctp_cmp_addr_exact(&t->ipaddr,
925 &asoc->peer.primary_addr)) {
926 sctp_assoc_del_peer(asoc, &t->ipaddr);
927 }
928 }
929 }
930
931 /* Helper function to set sk_err on a 1-1 style socket. */
932 static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
933 {
934 struct sock *sk = asoc->base.sk;
935
936 if (!sctp_style(sk, UDP))
937 sk->sk_err = error;
938 }
939
940 /* Helper function to generate an association change event */
941 static void sctp_cmd_assoc_change(sctp_cmd_seq_t *commands,
942 struct sctp_association *asoc,
943 u8 state)
944 {
945 struct sctp_ulpevent *ev;
946
947 ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0,
948 asoc->c.sinit_num_ostreams,
949 asoc->c.sinit_max_instreams,
950 NULL, GFP_ATOMIC);
951 if (ev)
952 sctp_ulpq_tail_event(&asoc->ulpq, ev);
953 }
954
955 /* Helper function to generate an adaptation indication event */
956 static void sctp_cmd_adaptation_ind(sctp_cmd_seq_t *commands,
957 struct sctp_association *asoc)
958 {
959 struct sctp_ulpevent *ev;
960
961 ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
962
963 if (ev)
964 sctp_ulpq_tail_event(&asoc->ulpq, ev);
965 }
966
967
968 static void sctp_cmd_t1_timer_update(struct sctp_association *asoc,
969 sctp_event_timeout_t timer,
970 char *name)
971 {
972 struct sctp_transport *t;
973
974 t = asoc->init_last_sent_to;
975 asoc->init_err_counter++;
976
977 if (t->init_sent_count > (asoc->init_cycle + 1)) {
978 asoc->timeouts[timer] *= 2;
979 if (asoc->timeouts[timer] > asoc->max_init_timeo) {
980 asoc->timeouts[timer] = asoc->max_init_timeo;
981 }
982 asoc->init_cycle++;
983 SCTP_DEBUG_PRINTK(
984 "T1 %s Timeout adjustment"
985 " init_err_counter: %d"
986 " cycle: %d"
987 " timeout: %ld\n",
988 name,
989 asoc->init_err_counter,
990 asoc->init_cycle,
991 asoc->timeouts[timer]);
992 }
993
994 }
995
996 /* Send the whole message, chunk by chunk, to the outqueue.
997 * This way the whole message is queued up and bundling if
998 * encouraged for small fragments.
999 */
1000 static int sctp_cmd_send_msg(struct sctp_association *asoc,
1001 struct sctp_datamsg *msg)
1002 {
1003 struct sctp_chunk *chunk;
1004 int error = 0;
1005
1006 list_for_each_entry(chunk, &msg->chunks, frag_list) {
1007 error = sctp_outq_tail(&asoc->outqueue, chunk);
1008 if (error)
1009 break;
1010 }
1011
1012 return error;
1013 }
1014
1015
1016 /* Sent the next ASCONF packet currently stored in the association.
1017 * This happens after the ASCONF_ACK was succeffully processed.
1018 */
1019 static void sctp_cmd_send_asconf(struct sctp_association *asoc)
1020 {
1021 /* Send the next asconf chunk from the addip chunk
1022 * queue.
1023 */
1024 if (!list_empty(&asoc->addip_chunk_list)) {
1025 struct list_head *entry = asoc->addip_chunk_list.next;
1026 struct sctp_chunk *asconf = list_entry(entry,
1027 struct sctp_chunk, list);
1028 list_del_init(entry);
1029
1030 /* Hold the chunk until an ASCONF_ACK is received. */
1031 sctp_chunk_hold(asconf);
1032 if (sctp_primitive_ASCONF(asoc, asconf))
1033 sctp_chunk_free(asconf);
1034 else
1035 asoc->addip_last_asconf = asconf;
1036 }
1037 }
1038
1039
1040 /* These three macros allow us to pull the debugging code out of the
1041 * main flow of sctp_do_sm() to keep attention focused on the real
1042 * functionality there.
1043 */
1044 #define DEBUG_PRE \
1045 SCTP_DEBUG_PRINTK("sctp_do_sm prefn: " \
1046 "ep %p, %s, %s, asoc %p[%s], %s\n", \
1047 ep, sctp_evttype_tbl[event_type], \
1048 (*debug_fn)(subtype), asoc, \
1049 sctp_state_tbl[state], state_fn->name)
1050
1051 #define DEBUG_POST \
1052 SCTP_DEBUG_PRINTK("sctp_do_sm postfn: " \
1053 "asoc %p, status: %s\n", \
1054 asoc, sctp_status_tbl[status])
1055
1056 #define DEBUG_POST_SFX \
1057 SCTP_DEBUG_PRINTK("sctp_do_sm post sfx: error %d, asoc %p[%s]\n", \
1058 error, asoc, \
1059 sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
1060 sctp_assoc2id(asoc)))?asoc->state:SCTP_STATE_CLOSED])
1061
1062 /*
1063 * This is the master state machine processing function.
1064 *
1065 * If you want to understand all of lksctp, this is a
1066 * good place to start.
1067 */
1068 int sctp_do_sm(sctp_event_t event_type, sctp_subtype_t subtype,
1069 sctp_state_t state,
1070 struct sctp_endpoint *ep,
1071 struct sctp_association *asoc,
1072 void *event_arg,
1073 gfp_t gfp)
1074 {
1075 sctp_cmd_seq_t commands;
1076 const sctp_sm_table_entry_t *state_fn;
1077 sctp_disposition_t status;
1078 int error = 0;
1079 typedef const char *(printfn_t)(sctp_subtype_t);
1080
1081 static printfn_t *table[] = {
1082 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
1083 };
1084 printfn_t *debug_fn __attribute__ ((unused)) = table[event_type];
1085
1086 /* Look up the state function, run it, and then process the
1087 * side effects. These three steps are the heart of lksctp.
1088 */
1089 state_fn = sctp_sm_lookup_event(event_type, state, subtype);
1090
1091 sctp_init_cmd_seq(&commands);
1092
1093 DEBUG_PRE;
1094 status = (*state_fn->fn)(ep, asoc, subtype, event_arg, &commands);
1095 DEBUG_POST;
1096
1097 error = sctp_side_effects(event_type, subtype, state,
1098 ep, asoc, event_arg, status,
1099 &commands, gfp);
1100 DEBUG_POST_SFX;
1101
1102 return error;
1103 }
1104
1105 #undef DEBUG_PRE
1106 #undef DEBUG_POST
1107
1108 /*****************************************************************
1109 * This the master state function side effect processing function.
1110 *****************************************************************/
1111 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
1112 sctp_state_t state,
1113 struct sctp_endpoint *ep,
1114 struct sctp_association *asoc,
1115 void *event_arg,
1116 sctp_disposition_t status,
1117 sctp_cmd_seq_t *commands,
1118 gfp_t gfp)
1119 {
1120 int error;
1121
1122 /* FIXME - Most of the dispositions left today would be categorized
1123 * as "exceptional" dispositions. For those dispositions, it
1124 * may not be proper to run through any of the commands at all.
1125 * For example, the command interpreter might be run only with
1126 * disposition SCTP_DISPOSITION_CONSUME.
1127 */
1128 if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
1129 ep, asoc,
1130 event_arg, status,
1131 commands, gfp)))
1132 goto bail;
1133
1134 switch (status) {
1135 case SCTP_DISPOSITION_DISCARD:
1136 SCTP_DEBUG_PRINTK("Ignored sctp protocol event - state %d, "
1137 "event_type %d, event_id %d\n",
1138 state, event_type, subtype.chunk);
1139 break;
1140
1141 case SCTP_DISPOSITION_NOMEM:
1142 /* We ran out of memory, so we need to discard this
1143 * packet.
1144 */
1145 /* BUG--we should now recover some memory, probably by
1146 * reneging...
1147 */
1148 error = -ENOMEM;
1149 break;
1150
1151 case SCTP_DISPOSITION_DELETE_TCB:
1152 /* This should now be a command. */
1153 break;
1154
1155 case SCTP_DISPOSITION_CONSUME:
1156 case SCTP_DISPOSITION_ABORT:
1157 /*
1158 * We should no longer have much work to do here as the
1159 * real work has been done as explicit commands above.
1160 */
1161 break;
1162
1163 case SCTP_DISPOSITION_VIOLATION:
1164 if (net_ratelimit())
1165 pr_err("protocol violation state %d chunkid %d\n",
1166 state, subtype.chunk);
1167 break;
1168
1169 case SCTP_DISPOSITION_NOT_IMPL:
1170 pr_warn("unimplemented feature in state %d, event_type %d, event_id %d\n",
1171 state, event_type, subtype.chunk);
1172 break;
1173
1174 case SCTP_DISPOSITION_BUG:
1175 pr_err("bug in state %d, event_type %d, event_id %d\n",
1176 state, event_type, subtype.chunk);
1177 BUG();
1178 break;
1179
1180 default:
1181 pr_err("impossible disposition %d in state %d, event_type %d, event_id %d\n",
1182 status, state, event_type, subtype.chunk);
1183 BUG();
1184 break;
1185 }
1186
1187 bail:
1188 return error;
1189 }
1190
1191 /********************************************************************
1192 * 2nd Level Abstractions
1193 ********************************************************************/
1194
1195 /* This is the side-effect interpreter. */
1196 static int sctp_cmd_interpreter(sctp_event_t event_type,
1197 sctp_subtype_t subtype,
1198 sctp_state_t state,
1199 struct sctp_endpoint *ep,
1200 struct sctp_association *asoc,
1201 void *event_arg,
1202 sctp_disposition_t status,
1203 sctp_cmd_seq_t *commands,
1204 gfp_t gfp)
1205 {
1206 int error = 0;
1207 int force;
1208 sctp_cmd_t *cmd;
1209 struct sctp_chunk *new_obj;
1210 struct sctp_chunk *chunk = NULL;
1211 struct sctp_packet *packet;
1212 struct timer_list *timer;
1213 unsigned long timeout;
1214 struct sctp_transport *t;
1215 struct sctp_sackhdr sackh;
1216 int local_cork = 0;
1217
1218 if (SCTP_EVENT_T_TIMEOUT != event_type)
1219 chunk = event_arg;
1220
1221 /* Note: This whole file is a huge candidate for rework.
1222 * For example, each command could either have its own handler, so
1223 * the loop would look like:
1224 * while (cmds)
1225 * cmd->handle(x, y, z)
1226 * --jgrimm
1227 */
1228 while (NULL != (cmd = sctp_next_cmd(commands))) {
1229 switch (cmd->verb) {
1230 case SCTP_CMD_NOP:
1231 /* Do nothing. */
1232 break;
1233
1234 case SCTP_CMD_NEW_ASOC:
1235 /* Register a new association. */
1236 if (local_cork) {
1237 sctp_outq_uncork(&asoc->outqueue);
1238 local_cork = 0;
1239 }
1240 asoc = cmd->obj.ptr;
1241 /* Register with the endpoint. */
1242 sctp_endpoint_add_asoc(ep, asoc);
1243 sctp_hash_established(asoc);
1244 break;
1245
1246 case SCTP_CMD_UPDATE_ASSOC:
1247 sctp_assoc_update(asoc, cmd->obj.ptr);
1248 break;
1249
1250 case SCTP_CMD_PURGE_OUTQUEUE:
1251 sctp_outq_teardown(&asoc->outqueue);
1252 break;
1253
1254 case SCTP_CMD_DELETE_TCB:
1255 if (local_cork) {
1256 sctp_outq_uncork(&asoc->outqueue);
1257 local_cork = 0;
1258 }
1259 /* Delete the current association. */
1260 sctp_cmd_delete_tcb(commands, asoc);
1261 asoc = NULL;
1262 break;
1263
1264 case SCTP_CMD_NEW_STATE:
1265 /* Enter a new state. */
1266 sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1267 break;
1268
1269 case SCTP_CMD_REPORT_TSN:
1270 /* Record the arrival of a TSN. */
1271 error = sctp_tsnmap_mark(&asoc->peer.tsn_map,
1272 cmd->obj.u32);
1273 break;
1274
1275 case SCTP_CMD_REPORT_FWDTSN:
1276 /* Move the Cumulattive TSN Ack ahead. */
1277 sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32);
1278
1279 /* purge the fragmentation queue */
1280 sctp_ulpq_reasm_flushtsn(&asoc->ulpq, cmd->obj.u32);
1281
1282 /* Abort any in progress partial delivery. */
1283 sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
1284 break;
1285
1286 case SCTP_CMD_PROCESS_FWDTSN:
1287 sctp_cmd_process_fwdtsn(&asoc->ulpq, cmd->obj.ptr);
1288 break;
1289
1290 case SCTP_CMD_GEN_SACK:
1291 /* Generate a Selective ACK.
1292 * The argument tells us whether to just count
1293 * the packet and MAYBE generate a SACK, or
1294 * force a SACK out.
1295 */
1296 force = cmd->obj.i32;
1297 error = sctp_gen_sack(asoc, force, commands);
1298 break;
1299
1300 case SCTP_CMD_PROCESS_SACK:
1301 /* Process an inbound SACK. */
1302 error = sctp_cmd_process_sack(commands, asoc,
1303 cmd->obj.ptr);
1304 break;
1305
1306 case SCTP_CMD_GEN_INIT_ACK:
1307 /* Generate an INIT ACK chunk. */
1308 new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1309 0);
1310 if (!new_obj)
1311 goto nomem;
1312
1313 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1314 SCTP_CHUNK(new_obj));
1315 break;
1316
1317 case SCTP_CMD_PEER_INIT:
1318 /* Process a unified INIT from the peer.
1319 * Note: Only used during INIT-ACK processing. If
1320 * there is an error just return to the outter
1321 * layer which will bail.
1322 */
1323 error = sctp_cmd_process_init(commands, asoc, chunk,
1324 cmd->obj.ptr, gfp);
1325 break;
1326
1327 case SCTP_CMD_GEN_COOKIE_ECHO:
1328 /* Generate a COOKIE ECHO chunk. */
1329 new_obj = sctp_make_cookie_echo(asoc, chunk);
1330 if (!new_obj) {
1331 if (cmd->obj.ptr)
1332 sctp_chunk_free(cmd->obj.ptr);
1333 goto nomem;
1334 }
1335 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1336 SCTP_CHUNK(new_obj));
1337
1338 /* If there is an ERROR chunk to be sent along with
1339 * the COOKIE_ECHO, send it, too.
1340 */
1341 if (cmd->obj.ptr)
1342 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1343 SCTP_CHUNK(cmd->obj.ptr));
1344
1345 if (new_obj->transport) {
1346 new_obj->transport->init_sent_count++;
1347 asoc->init_last_sent_to = new_obj->transport;
1348 }
1349
1350 /* FIXME - Eventually come up with a cleaner way to
1351 * enabling COOKIE-ECHO + DATA bundling during
1352 * multihoming stale cookie scenarios, the following
1353 * command plays with asoc->peer.retran_path to
1354 * avoid the problem of sending the COOKIE-ECHO and
1355 * DATA in different paths, which could result
1356 * in the association being ABORTed if the DATA chunk
1357 * is processed first by the server. Checking the
1358 * init error counter simply causes this command
1359 * to be executed only during failed attempts of
1360 * association establishment.
1361 */
1362 if ((asoc->peer.retran_path !=
1363 asoc->peer.primary_path) &&
1364 (asoc->init_err_counter > 0)) {
1365 sctp_add_cmd_sf(commands,
1366 SCTP_CMD_FORCE_PRIM_RETRAN,
1367 SCTP_NULL());
1368 }
1369
1370 break;
1371
1372 case SCTP_CMD_GEN_SHUTDOWN:
1373 /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1374 * Reset error counts.
1375 */
1376 asoc->overall_error_count = 0;
1377
1378 /* Generate a SHUTDOWN chunk. */
1379 new_obj = sctp_make_shutdown(asoc, chunk);
1380 if (!new_obj)
1381 goto nomem;
1382 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1383 SCTP_CHUNK(new_obj));
1384 break;
1385
1386 case SCTP_CMD_CHUNK_ULP:
1387 /* Send a chunk to the sockets layer. */
1388 SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1389 "chunk_up:", cmd->obj.ptr,
1390 "ulpq:", &asoc->ulpq);
1391 sctp_ulpq_tail_data(&asoc->ulpq, cmd->obj.ptr,
1392 GFP_ATOMIC);
1393 break;
1394
1395 case SCTP_CMD_EVENT_ULP:
1396 /* Send a notification to the sockets layer. */
1397 SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1398 "event_up:",cmd->obj.ptr,
1399 "ulpq:",&asoc->ulpq);
1400 sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ptr);
1401 break;
1402
1403 case SCTP_CMD_REPLY:
1404 /* If an caller has not already corked, do cork. */
1405 if (!asoc->outqueue.cork) {
1406 sctp_outq_cork(&asoc->outqueue);
1407 local_cork = 1;
1408 }
1409 /* Send a chunk to our peer. */
1410 error = sctp_outq_tail(&asoc->outqueue, cmd->obj.ptr);
1411 break;
1412
1413 case SCTP_CMD_SEND_PKT:
1414 /* Send a full packet to our peer. */
1415 packet = cmd->obj.ptr;
1416 sctp_packet_transmit(packet);
1417 sctp_ootb_pkt_free(packet);
1418 break;
1419
1420 case SCTP_CMD_T1_RETRAN:
1421 /* Mark a transport for retransmission. */
1422 sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1423 SCTP_RTXR_T1_RTX);
1424 break;
1425
1426 case SCTP_CMD_RETRAN:
1427 /* Mark a transport for retransmission. */
1428 sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1429 SCTP_RTXR_T3_RTX);
1430 break;
1431
1432 case SCTP_CMD_ECN_CE:
1433 /* Do delayed CE processing. */
1434 sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1435 break;
1436
1437 case SCTP_CMD_ECN_ECNE:
1438 /* Do delayed ECNE processing. */
1439 new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1440 chunk);
1441 if (new_obj)
1442 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1443 SCTP_CHUNK(new_obj));
1444 break;
1445
1446 case SCTP_CMD_ECN_CWR:
1447 /* Do delayed CWR processing. */
1448 sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1449 break;
1450
1451 case SCTP_CMD_SETUP_T2:
1452 sctp_cmd_setup_t2(commands, asoc, cmd->obj.ptr);
1453 break;
1454
1455 case SCTP_CMD_TIMER_START_ONCE:
1456 timer = &asoc->timers[cmd->obj.to];
1457
1458 if (timer_pending(timer))
1459 break;
1460 /* fall through */
1461
1462 case SCTP_CMD_TIMER_START:
1463 timer = &asoc->timers[cmd->obj.to];
1464 timeout = asoc->timeouts[cmd->obj.to];
1465 BUG_ON(!timeout);
1466
1467 timer->expires = jiffies + timeout;
1468 sctp_association_hold(asoc);
1469 add_timer(timer);
1470 break;
1471
1472 case SCTP_CMD_TIMER_RESTART:
1473 timer = &asoc->timers[cmd->obj.to];
1474 timeout = asoc->timeouts[cmd->obj.to];
1475 if (!mod_timer(timer, jiffies + timeout))
1476 sctp_association_hold(asoc);
1477 break;
1478
1479 case SCTP_CMD_TIMER_STOP:
1480 timer = &asoc->timers[cmd->obj.to];
1481 if (timer_pending(timer) && del_timer(timer))
1482 sctp_association_put(asoc);
1483 break;
1484
1485 case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1486 chunk = cmd->obj.ptr;
1487 t = sctp_assoc_choose_alter_transport(asoc,
1488 asoc->init_last_sent_to);
1489 asoc->init_last_sent_to = t;
1490 chunk->transport = t;
1491 t->init_sent_count++;
1492 /* Set the new transport as primary */
1493 sctp_assoc_set_primary(asoc, t);
1494 break;
1495
1496 case SCTP_CMD_INIT_RESTART:
1497 /* Do the needed accounting and updates
1498 * associated with restarting an initialization
1499 * timer. Only multiply the timeout by two if
1500 * all transports have been tried at the current
1501 * timeout.
1502 */
1503 sctp_cmd_t1_timer_update(asoc,
1504 SCTP_EVENT_TIMEOUT_T1_INIT,
1505 "INIT");
1506
1507 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1508 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1509 break;
1510
1511 case SCTP_CMD_COOKIEECHO_RESTART:
1512 /* Do the needed accounting and updates
1513 * associated with restarting an initialization
1514 * timer. Only multiply the timeout by two if
1515 * all transports have been tried at the current
1516 * timeout.
1517 */
1518 sctp_cmd_t1_timer_update(asoc,
1519 SCTP_EVENT_TIMEOUT_T1_COOKIE,
1520 "COOKIE");
1521
1522 /* If we've sent any data bundled with
1523 * COOKIE-ECHO we need to resend.
1524 */
1525 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1526 transports) {
1527 sctp_retransmit_mark(&asoc->outqueue, t,
1528 SCTP_RTXR_T1_RTX);
1529 }
1530
1531 sctp_add_cmd_sf(commands,
1532 SCTP_CMD_TIMER_RESTART,
1533 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1534 break;
1535
1536 case SCTP_CMD_INIT_FAILED:
1537 sctp_cmd_init_failed(commands, asoc, cmd->obj.err);
1538 break;
1539
1540 case SCTP_CMD_ASSOC_FAILED:
1541 sctp_cmd_assoc_failed(commands, asoc, event_type,
1542 subtype, chunk, cmd->obj.err);
1543 break;
1544
1545 case SCTP_CMD_INIT_COUNTER_INC:
1546 asoc->init_err_counter++;
1547 break;
1548
1549 case SCTP_CMD_INIT_COUNTER_RESET:
1550 asoc->init_err_counter = 0;
1551 asoc->init_cycle = 0;
1552 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1553 transports) {
1554 t->init_sent_count = 0;
1555 }
1556 break;
1557
1558 case SCTP_CMD_REPORT_DUP:
1559 sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1560 cmd->obj.u32);
1561 break;
1562
1563 case SCTP_CMD_REPORT_BAD_TAG:
1564 SCTP_DEBUG_PRINTK("vtag mismatch!\n");
1565 break;
1566
1567 case SCTP_CMD_STRIKE:
1568 /* Mark one strike against a transport. */
1569 sctp_do_8_2_transport_strike(asoc, cmd->obj.transport,
1570 0);
1571 break;
1572
1573 case SCTP_CMD_TRANSPORT_IDLE:
1574 t = cmd->obj.transport;
1575 sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
1576 break;
1577
1578 case SCTP_CMD_TRANSPORT_HB_SENT:
1579 t = cmd->obj.transport;
1580 sctp_do_8_2_transport_strike(asoc, t, 1);
1581 t->hb_sent = 1;
1582 break;
1583
1584 case SCTP_CMD_TRANSPORT_ON:
1585 t = cmd->obj.transport;
1586 sctp_cmd_transport_on(commands, asoc, t, chunk);
1587 break;
1588
1589 case SCTP_CMD_HB_TIMERS_START:
1590 sctp_cmd_hb_timers_start(commands, asoc);
1591 break;
1592
1593 case SCTP_CMD_HB_TIMER_UPDATE:
1594 t = cmd->obj.transport;
1595 sctp_cmd_hb_timer_update(commands, t);
1596 break;
1597
1598 case SCTP_CMD_HB_TIMERS_STOP:
1599 sctp_cmd_hb_timers_stop(commands, asoc);
1600 break;
1601
1602 case SCTP_CMD_REPORT_ERROR:
1603 error = cmd->obj.error;
1604 break;
1605
1606 case SCTP_CMD_PROCESS_CTSN:
1607 /* Dummy up a SACK for processing. */
1608 sackh.cum_tsn_ack = cmd->obj.be32;
1609 sackh.a_rwnd = asoc->peer.rwnd +
1610 asoc->outqueue.outstanding_bytes;
1611 sackh.num_gap_ack_blocks = 0;
1612 sackh.num_dup_tsns = 0;
1613 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1614 SCTP_SACKH(&sackh));
1615 break;
1616
1617 case SCTP_CMD_DISCARD_PACKET:
1618 /* We need to discard the whole packet.
1619 * Uncork the queue since there might be
1620 * responses pending
1621 */
1622 chunk->pdiscard = 1;
1623 if (asoc) {
1624 sctp_outq_uncork(&asoc->outqueue);
1625 local_cork = 0;
1626 }
1627 break;
1628
1629 case SCTP_CMD_RTO_PENDING:
1630 t = cmd->obj.transport;
1631 t->rto_pending = 1;
1632 break;
1633
1634 case SCTP_CMD_PART_DELIVER:
1635 sctp_ulpq_partial_delivery(&asoc->ulpq, cmd->obj.ptr,
1636 GFP_ATOMIC);
1637 break;
1638
1639 case SCTP_CMD_RENEGE:
1640 sctp_ulpq_renege(&asoc->ulpq, cmd->obj.ptr,
1641 GFP_ATOMIC);
1642 break;
1643
1644 case SCTP_CMD_SETUP_T4:
1645 sctp_cmd_setup_t4(commands, asoc, cmd->obj.ptr);
1646 break;
1647
1648 case SCTP_CMD_PROCESS_OPERR:
1649 sctp_cmd_process_operr(commands, asoc, chunk);
1650 break;
1651 case SCTP_CMD_CLEAR_INIT_TAG:
1652 asoc->peer.i.init_tag = 0;
1653 break;
1654 case SCTP_CMD_DEL_NON_PRIMARY:
1655 sctp_cmd_del_non_primary(asoc);
1656 break;
1657 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1658 sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1659 break;
1660 case SCTP_CMD_FORCE_PRIM_RETRAN:
1661 t = asoc->peer.retran_path;
1662 asoc->peer.retran_path = asoc->peer.primary_path;
1663 error = sctp_outq_uncork(&asoc->outqueue);
1664 local_cork = 0;
1665 asoc->peer.retran_path = t;
1666 break;
1667 case SCTP_CMD_SET_SK_ERR:
1668 sctp_cmd_set_sk_err(asoc, cmd->obj.error);
1669 break;
1670 case SCTP_CMD_ASSOC_CHANGE:
1671 sctp_cmd_assoc_change(commands, asoc,
1672 cmd->obj.u8);
1673 break;
1674 case SCTP_CMD_ADAPTATION_IND:
1675 sctp_cmd_adaptation_ind(commands, asoc);
1676 break;
1677
1678 case SCTP_CMD_ASSOC_SHKEY:
1679 error = sctp_auth_asoc_init_active_key(asoc,
1680 GFP_ATOMIC);
1681 break;
1682 case SCTP_CMD_UPDATE_INITTAG:
1683 asoc->peer.i.init_tag = cmd->obj.u32;
1684 break;
1685 case SCTP_CMD_SEND_MSG:
1686 if (!asoc->outqueue.cork) {
1687 sctp_outq_cork(&asoc->outqueue);
1688 local_cork = 1;
1689 }
1690 error = sctp_cmd_send_msg(asoc, cmd->obj.msg);
1691 break;
1692 case SCTP_CMD_SEND_NEXT_ASCONF:
1693 sctp_cmd_send_asconf(asoc);
1694 break;
1695 case SCTP_CMD_PURGE_ASCONF_QUEUE:
1696 sctp_asconf_queue_teardown(asoc);
1697 break;
1698
1699 case SCTP_CMD_SET_ASOC:
1700 asoc = cmd->obj.asoc;
1701 break;
1702
1703 default:
1704 pr_warn("Impossible command: %u, %p\n",
1705 cmd->verb, cmd->obj.ptr);
1706 break;
1707 }
1708
1709 if (error)
1710 break;
1711 }
1712
1713 out:
1714 /* If this is in response to a received chunk, wait until
1715 * we are done with the packet to open the queue so that we don't
1716 * send multiple packets in response to a single request.
1717 */
1718 if (asoc && SCTP_EVENT_T_CHUNK == event_type && chunk) {
1719 if (chunk->end_of_packet || chunk->singleton)
1720 error = sctp_outq_uncork(&asoc->outqueue);
1721 } else if (local_cork)
1722 error = sctp_outq_uncork(&asoc->outqueue);
1723 return error;
1724 nomem:
1725 error = -ENOMEM;
1726 goto out;
1727 }
1728