[SCTP] sctp_connectx() API support
[linux-2.6.git] / net / sctp / sm_sideeffect.c
1 /* SCTP kernel reference 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 reference 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  * The SCTP reference 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  * The SCTP reference 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 #include <linux/skbuff.h>
51 #include <linux/types.h>
52 #include <linux/socket.h>
53 #include <linux/ip.h>
54 #include <net/sock.h>
55 #include <net/sctp/sctp.h>
56 #include <net/sctp/sm.h>
57
58 static int sctp_cmd_interpreter(sctp_event_t event_type,
59                                 sctp_subtype_t subtype,
60                                 sctp_state_t state,
61                                 struct sctp_endpoint *ep,
62                                 struct sctp_association *asoc,
63                                 void *event_arg,
64                                 sctp_disposition_t status,
65                                 sctp_cmd_seq_t *commands,
66                                 int gfp);
67 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
68                              sctp_state_t state,
69                              struct sctp_endpoint *ep,
70                              struct sctp_association *asoc,
71                              void *event_arg,
72                              sctp_disposition_t status,
73                              sctp_cmd_seq_t *commands,
74                              int gfp);
75
76 /********************************************************************
77  * Helper functions
78  ********************************************************************/
79
80 /* A helper function for delayed processing of INET ECN CE bit. */
81 static void sctp_do_ecn_ce_work(struct sctp_association *asoc, 
82                                 __u32 lowest_tsn)
83 {
84         /* Save the TSN away for comparison when we receive CWR */
85
86         asoc->last_ecne_tsn = lowest_tsn;
87         asoc->need_ecne = 1;
88 }
89
90 /* Helper function for delayed processing of SCTP ECNE chunk.  */
91 /* RFC 2960 Appendix A
92  *
93  * RFC 2481 details a specific bit for a sender to send in
94  * the header of its next outbound TCP segment to indicate to
95  * its peer that it has reduced its congestion window.  This
96  * is termed the CWR bit.  For SCTP the same indication is made
97  * by including the CWR chunk.  This chunk contains one data
98  * element, i.e. the TSN number that was sent in the ECNE chunk.
99  * This element represents the lowest TSN number in the datagram
100  * that was originally marked with the CE bit.
101  */
102 static struct sctp_chunk *sctp_do_ecn_ecne_work(struct sctp_association *asoc,
103                                            __u32 lowest_tsn,
104                                            struct sctp_chunk *chunk)
105 {
106         struct sctp_chunk *repl;
107
108         /* Our previously transmitted packet ran into some congestion
109          * so we should take action by reducing cwnd and ssthresh
110          * and then ACK our peer that we we've done so by
111          * sending a CWR.
112          */
113
114         /* First, try to determine if we want to actually lower
115          * our cwnd variables.  Only lower them if the ECNE looks more
116          * recent than the last response.
117          */
118         if (TSN_lt(asoc->last_cwr_tsn, lowest_tsn)) {
119                 struct sctp_transport *transport;
120
121                 /* Find which transport's congestion variables
122                  * need to be adjusted.
123                  */
124                 transport = sctp_assoc_lookup_tsn(asoc, lowest_tsn);
125
126                 /* Update the congestion variables. */
127                 if (transport)
128                         sctp_transport_lower_cwnd(transport,
129                                                   SCTP_LOWER_CWND_ECNE);
130                 asoc->last_cwr_tsn = lowest_tsn;
131         }
132
133         /* Always try to quiet the other end.  In case of lost CWR,
134          * resend last_cwr_tsn.
135          */
136         repl = sctp_make_cwr(asoc, asoc->last_cwr_tsn, chunk);
137
138         /* If we run out of memory, it will look like a lost CWR.  We'll
139          * get back in sync eventually.
140          */
141         return repl;
142 }
143
144 /* Helper function to do delayed processing of ECN CWR chunk.  */
145 static void sctp_do_ecn_cwr_work(struct sctp_association *asoc,
146                                  __u32 lowest_tsn)
147 {
148         /* Turn off ECNE getting auto-prepended to every outgoing
149          * packet
150          */
151         asoc->need_ecne = 0;
152 }
153
154 /* Generate SACK if necessary.  We call this at the end of a packet.  */
155 static int sctp_gen_sack(struct sctp_association *asoc, int force,
156                          sctp_cmd_seq_t *commands)
157 {
158         __u32 ctsn, max_tsn_seen;
159         struct sctp_chunk *sack;
160         int error = 0;
161
162         if (force)
163                 asoc->peer.sack_needed = 1;
164
165         ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
166         max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
167
168         /* From 12.2 Parameters necessary per association (i.e. the TCB):
169          *
170          * Ack State : This flag indicates if the next received packet
171          *           : is to be responded to with a SACK. ...
172          *           : When DATA chunks are out of order, SACK's
173          *           : are not delayed (see Section 6).
174          *
175          * [This is actually not mentioned in Section 6, but we
176          * implement it here anyway. --piggy]
177          */
178         if (max_tsn_seen != ctsn)
179                 asoc->peer.sack_needed = 1;
180
181         /* From 6.2  Acknowledgement on Reception of DATA Chunks:
182          *
183          * Section 4.2 of [RFC2581] SHOULD be followed. Specifically,
184          * an acknowledgement SHOULD be generated for at least every
185          * second packet (not every second DATA chunk) received, and
186          * SHOULD be generated within 200 ms of the arrival of any
187          * unacknowledged DATA chunk. ...
188          */
189         if (!asoc->peer.sack_needed) {
190                 /* We will need a SACK for the next packet.  */
191                 asoc->peer.sack_needed = 1;
192                 goto out;
193         } else {
194                 if (asoc->a_rwnd > asoc->rwnd)
195                         asoc->a_rwnd = asoc->rwnd;
196                 sack = sctp_make_sack(asoc);
197                 if (!sack)
198                         goto nomem;
199
200                 asoc->peer.sack_needed = 0;
201
202                 error = sctp_outq_tail(&asoc->outqueue, sack);
203
204                 /* Stop the SACK timer.  */
205                 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
206                                 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
207         }
208 out:
209         return error;
210 nomem:
211         error = -ENOMEM;
212         return error;
213 }
214
215 /* When the T3-RTX timer expires, it calls this function to create the
216  * relevant state machine event.
217  */
218 void sctp_generate_t3_rtx_event(unsigned long peer)
219 {
220         int error;
221         struct sctp_transport *transport = (struct sctp_transport *) peer;
222         struct sctp_association *asoc = transport->asoc;
223
224         /* Check whether a task is in the sock.  */
225
226         sctp_bh_lock_sock(asoc->base.sk);
227         if (sock_owned_by_user(asoc->base.sk)) {
228                 SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __FUNCTION__);
229
230                 /* Try again later.  */
231                 if (!mod_timer(&transport->T3_rtx_timer, jiffies + (HZ/20)))
232                         sctp_transport_hold(transport);
233                 goto out_unlock;
234         }
235
236         /* Is this transport really dead and just waiting around for
237          * the timer to let go of the reference?
238          */
239         if (transport->dead)
240                 goto out_unlock;
241
242         /* Run through the state machine.  */
243         error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
244                            SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX),
245                            asoc->state,
246                            asoc->ep, asoc,
247                            transport, GFP_ATOMIC);
248
249         if (error)
250                 asoc->base.sk->sk_err = -error;
251
252 out_unlock:
253         sctp_bh_unlock_sock(asoc->base.sk);
254         sctp_transport_put(transport);
255 }
256
257 /* This is a sa interface for producing timeout events.  It works
258  * for timeouts which use the association as their parameter.
259  */
260 static void sctp_generate_timeout_event(struct sctp_association *asoc,
261                                         sctp_event_timeout_t timeout_type)
262 {
263         int error = 0;
264
265         sctp_bh_lock_sock(asoc->base.sk);
266         if (sock_owned_by_user(asoc->base.sk)) {
267                 SCTP_DEBUG_PRINTK("%s:Sock is busy: timer %d\n",
268                                   __FUNCTION__,
269                                   timeout_type);
270
271                 /* Try again later.  */
272                 if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20)))
273                         sctp_association_hold(asoc);
274                 goto out_unlock;
275         }
276
277         /* Is this association really dead and just waiting around for
278          * the timer to let go of the reference?
279          */
280         if (asoc->base.dead)
281                 goto out_unlock;
282
283         /* Run through the state machine.  */
284         error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
285                            SCTP_ST_TIMEOUT(timeout_type),
286                            asoc->state, asoc->ep, asoc,
287                            (void *)timeout_type, GFP_ATOMIC);
288
289         if (error)
290                 asoc->base.sk->sk_err = -error;
291
292 out_unlock:
293         sctp_bh_unlock_sock(asoc->base.sk);
294         sctp_association_put(asoc);
295 }
296
297 static void sctp_generate_t1_cookie_event(unsigned long data)
298 {
299         struct sctp_association *asoc = (struct sctp_association *) data;
300         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
301 }
302
303 static void sctp_generate_t1_init_event(unsigned long data)
304 {
305         struct sctp_association *asoc = (struct sctp_association *) data;
306         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
307 }
308
309 static void sctp_generate_t2_shutdown_event(unsigned long data)
310 {
311         struct sctp_association *asoc = (struct sctp_association *) data;
312         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
313 }
314
315 static void sctp_generate_t4_rto_event(unsigned long data)
316 {
317         struct sctp_association *asoc = (struct sctp_association *) data;
318         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
319 }
320
321 static void sctp_generate_t5_shutdown_guard_event(unsigned long data)
322 {
323         struct sctp_association *asoc = (struct sctp_association *)data;
324         sctp_generate_timeout_event(asoc,
325                                     SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);
326
327 } /* sctp_generate_t5_shutdown_guard_event() */
328
329 static void sctp_generate_autoclose_event(unsigned long data)
330 {
331         struct sctp_association *asoc = (struct sctp_association *) data;
332         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE);
333 }
334
335 /* Generate a heart beat event.  If the sock is busy, reschedule.   Make
336  * sure that the transport is still valid.
337  */
338 void sctp_generate_heartbeat_event(unsigned long data)
339 {
340         int error = 0;
341         struct sctp_transport *transport = (struct sctp_transport *) data;
342         struct sctp_association *asoc = transport->asoc;
343
344         sctp_bh_lock_sock(asoc->base.sk);
345         if (sock_owned_by_user(asoc->base.sk)) {
346                 SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __FUNCTION__);
347
348                 /* Try again later.  */
349                 if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20)))
350                         sctp_transport_hold(transport);
351                 goto out_unlock;
352         }
353
354         /* Is this structure just waiting around for us to actually
355          * get destroyed?
356          */
357         if (transport->dead)
358                 goto out_unlock;
359
360         error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
361                            SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
362                            asoc->state, asoc->ep, asoc,
363                            transport, GFP_ATOMIC);
364
365          if (error)
366                  asoc->base.sk->sk_err = -error;
367
368 out_unlock:
369         sctp_bh_unlock_sock(asoc->base.sk);
370         sctp_transport_put(transport);
371 }
372
373 /* Inject a SACK Timeout event into the state machine.  */
374 static void sctp_generate_sack_event(unsigned long data)
375 {
376         struct sctp_association *asoc = (struct sctp_association *) data;
377         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
378 }
379
380 sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
381         NULL,
382         sctp_generate_t1_cookie_event,
383         sctp_generate_t1_init_event,
384         sctp_generate_t2_shutdown_event,
385         NULL,
386         sctp_generate_t4_rto_event,
387         sctp_generate_t5_shutdown_guard_event,
388         sctp_generate_heartbeat_event,
389         sctp_generate_sack_event,
390         sctp_generate_autoclose_event,
391 };
392
393
394 /* RFC 2960 8.2 Path Failure Detection
395  *
396  * When its peer endpoint is multi-homed, an endpoint should keep a
397  * error counter for each of the destination transport addresses of the
398  * peer endpoint.
399  *
400  * Each time the T3-rtx timer expires on any address, or when a
401  * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
402  * the error counter of that destination address will be incremented.
403  * When the value in the error counter exceeds the protocol parameter
404  * 'Path.Max.Retrans' of that destination address, the endpoint should
405  * mark the destination transport address as inactive, and a
406  * notification SHOULD be sent to the upper layer.
407  *
408  */
409 static void sctp_do_8_2_transport_strike(struct sctp_association *asoc,
410                                          struct sctp_transport *transport)
411 {
412         /* The check for association's overall error counter exceeding the
413          * threshold is done in the state function.
414          */
415         asoc->overall_error_count++;
416
417         if (transport->state != SCTP_INACTIVE &&
418             (transport->error_count++ >= transport->max_retrans)) {
419                 SCTP_DEBUG_PRINTK_IPADDR("transport_strike:association %p",
420                                          " transport IP: port:%d failed.\n",
421                                          asoc,
422                                          (&transport->ipaddr),
423                                          transport->ipaddr.v4.sin_port);
424                 sctp_assoc_control_transport(asoc, transport,
425                                              SCTP_TRANSPORT_DOWN,
426                                              SCTP_FAILED_THRESHOLD);
427         }
428
429         /* E2) For the destination address for which the timer
430          * expires, set RTO <- RTO * 2 ("back off the timer").  The
431          * maximum value discussed in rule C7 above (RTO.max) may be
432          * used to provide an upper bound to this doubling operation.
433          */
434         transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
435 }
436
437 /* Worker routine to handle INIT command failure.  */
438 static void sctp_cmd_init_failed(sctp_cmd_seq_t *commands,
439                                  struct sctp_association *asoc,
440                                  unsigned error)
441 {
442         struct sctp_ulpevent *event;
443
444         event = sctp_ulpevent_make_assoc_change(asoc,0, SCTP_CANT_STR_ASSOC,
445                                                 (__u16)error, 0, 0,
446                                                 GFP_ATOMIC);
447
448         if (event)
449                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
450                                 SCTP_ULPEVENT(event));
451
452         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
453                         SCTP_STATE(SCTP_STATE_CLOSED));
454
455         /* SEND_FAILED sent later when cleaning up the association. */
456         asoc->outqueue.error = error;
457         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
458 }
459
460 /* Worker routine to handle SCTP_CMD_ASSOC_FAILED.  */
461 static void sctp_cmd_assoc_failed(sctp_cmd_seq_t *commands,
462                                   struct sctp_association *asoc,
463                                   sctp_event_t event_type,
464                                   sctp_subtype_t subtype,
465                                   struct sctp_chunk *chunk,
466                                   unsigned error)
467 {
468         struct sctp_ulpevent *event;
469
470         /* Cancel any partial delivery in progress. */
471         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
472
473         event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
474                                                 (__u16)error, 0, 0,
475                                                 GFP_ATOMIC);
476         if (event)
477                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
478                                 SCTP_ULPEVENT(event));
479
480         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
481                         SCTP_STATE(SCTP_STATE_CLOSED));
482
483         /* Set sk_err to ECONNRESET on a 1-1 style socket. */
484         if (!sctp_style(asoc->base.sk, UDP))
485                 asoc->base.sk->sk_err = ECONNRESET; 
486
487         /* SEND_FAILED sent later when cleaning up the association. */
488         asoc->outqueue.error = error;
489         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
490 }
491
492 /* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
493  * inside the cookie.  In reality, this is only used for INIT-ACK processing
494  * since all other cases use "temporary" associations and can do all
495  * their work in statefuns directly.
496  */
497 static int sctp_cmd_process_init(sctp_cmd_seq_t *commands,
498                                  struct sctp_association *asoc,
499                                  struct sctp_chunk *chunk,
500                                  sctp_init_chunk_t *peer_init, int gfp)
501 {
502         int error;
503
504         /* We only process the init as a sideeffect in a single
505          * case.   This is when we process the INIT-ACK.   If we
506          * fail during INIT processing (due to malloc problems),
507          * just return the error and stop processing the stack.
508          */
509         if (!sctp_process_init(asoc, chunk->chunk_hdr->type,
510                                sctp_source(chunk), peer_init, gfp))
511                 error = -ENOMEM;
512         else
513                 error = 0;
514
515         return error;
516 }
517
518 /* Helper function to break out starting up of heartbeat timers.  */
519 static void sctp_cmd_hb_timers_start(sctp_cmd_seq_t *cmds,
520                                      struct sctp_association *asoc)
521 {
522         struct sctp_transport *t;
523         struct list_head *pos;
524
525         /* Start a heartbeat timer for each transport on the association.
526          * hold a reference on the transport to make sure none of
527          * the needed data structures go away.
528          */
529         list_for_each(pos, &asoc->peer.transport_addr_list) {
530                 t = list_entry(pos, struct sctp_transport, transports);
531
532                 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
533                         sctp_transport_hold(t);
534         }
535 }
536
537 static void sctp_cmd_hb_timers_stop(sctp_cmd_seq_t *cmds,
538                                     struct sctp_association *asoc)
539 {
540         struct sctp_transport *t;
541         struct list_head *pos;
542
543         /* Stop all heartbeat timers. */
544
545         list_for_each(pos, &asoc->peer.transport_addr_list) {
546                 t = list_entry(pos, struct sctp_transport, transports);
547                 if (del_timer(&t->hb_timer))
548                         sctp_transport_put(t);
549         }
550 }
551
552 /* Helper function to stop any pending T3-RTX timers */
553 static void sctp_cmd_t3_rtx_timers_stop(sctp_cmd_seq_t *cmds,
554                                         struct sctp_association *asoc)
555 {
556         struct sctp_transport *t;
557         struct list_head *pos;
558
559         list_for_each(pos, &asoc->peer.transport_addr_list) {
560                 t = list_entry(pos, struct sctp_transport, transports);
561                 if (timer_pending(&t->T3_rtx_timer) &&
562                     del_timer(&t->T3_rtx_timer)) {
563                         sctp_transport_put(t);
564                 }
565         }
566 }
567
568
569 /* Helper function to update the heartbeat timer. */
570 static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
571                                      struct sctp_association *asoc,
572                                      struct sctp_transport *t)
573 {
574         /* Update the heartbeat timer.  */
575         if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
576                 sctp_transport_hold(t);
577 }
578
579 /* Helper function to handle the reception of an HEARTBEAT ACK.  */
580 static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds,
581                                   struct sctp_association *asoc,
582                                   struct sctp_transport *t,
583                                   struct sctp_chunk *chunk)
584 {
585         sctp_sender_hb_info_t *hbinfo;
586
587         /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
588          * HEARTBEAT should clear the error counter of the destination
589          * transport address to which the HEARTBEAT was sent.
590          * The association's overall error count is also cleared.
591          */
592         t->error_count = 0;
593         t->asoc->overall_error_count = 0;
594
595         /* Mark the destination transport address as active if it is not so
596          * marked.
597          */
598         if (t->state == SCTP_INACTIVE)
599                 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
600                                              SCTP_HEARTBEAT_SUCCESS);
601
602         /* The receiver of the HEARTBEAT ACK should also perform an
603          * RTT measurement for that destination transport address
604          * using the time value carried in the HEARTBEAT ACK chunk.
605          */
606         hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
607         sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
608 }
609
610 /* Helper function to do a transport reset at the expiry of the hearbeat
611  * timer.
612  */
613 static void sctp_cmd_transport_reset(sctp_cmd_seq_t *cmds,
614                                      struct sctp_association *asoc,
615                                      struct sctp_transport *t)
616 {
617         sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
618
619         /* Mark one strike against a transport.  */
620         sctp_do_8_2_transport_strike(asoc, t);
621 }
622
623 /* Helper function to process the process SACK command.  */
624 static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds,
625                                  struct sctp_association *asoc,
626                                  struct sctp_sackhdr *sackh)
627 {
628         int err;
629
630         if (sctp_outq_sack(&asoc->outqueue, sackh)) {
631                 /* There are no more TSNs awaiting SACK.  */
632                 err = sctp_do_sm(SCTP_EVENT_T_OTHER,
633                                  SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
634                                  asoc->state, asoc->ep, asoc, NULL,
635                                  GFP_ATOMIC);
636         } else {
637                 /* Windows may have opened, so we need
638                  * to check if we have DATA to transmit
639                  */
640                 err = sctp_outq_flush(&asoc->outqueue, 0);
641         }
642
643         return err;
644 }
645
646 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
647  * the transport for a shutdown chunk.
648  */
649 static void sctp_cmd_setup_t2(sctp_cmd_seq_t *cmds, 
650                               struct sctp_association *asoc,
651                               struct sctp_chunk *chunk)
652 {
653         struct sctp_transport *t;
654
655         t = sctp_assoc_choose_shutdown_transport(asoc);
656         asoc->shutdown_last_sent_to = t;
657         asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
658         chunk->transport = t;
659 }
660
661 /* Helper function to change the state of an association. */
662 static void sctp_cmd_new_state(sctp_cmd_seq_t *cmds, 
663                                struct sctp_association *asoc,
664                                sctp_state_t state)
665 {
666         struct sock *sk = asoc->base.sk;
667
668         asoc->state = state;
669
670         SCTP_DEBUG_PRINTK("sctp_cmd_new_state: asoc %p[%s]\n",
671                           asoc, sctp_state_tbl[state]);
672
673         if (sctp_style(sk, TCP)) {
674                 /* Change the sk->sk_state of a TCP-style socket that has
675                  * sucessfully completed a connect() call.
676                  */
677                 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
678                         sk->sk_state = SCTP_SS_ESTABLISHED;
679
680                 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
681                 if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
682                     sctp_sstate(sk, ESTABLISHED))
683                         sk->sk_shutdown |= RCV_SHUTDOWN;
684         }
685
686         if (sctp_state(asoc, COOKIE_WAIT)) {
687                 /* Reset init timeouts since they may have been
688                  * increased due to timer expirations.
689                  */
690                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
691                         asoc->ep->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT];
692                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
693                         asoc->ep->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE];
694         }
695
696         if (sctp_state(asoc, ESTABLISHED) ||
697             sctp_state(asoc, CLOSED) ||
698             sctp_state(asoc, SHUTDOWN_RECEIVED)) {
699                 /* Wake up any processes waiting in the asoc's wait queue in
700                  * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
701                  */
702                 if (waitqueue_active(&asoc->wait))
703                         wake_up_interruptible(&asoc->wait);
704
705                 /* Wake up any processes waiting in the sk's sleep queue of
706                  * a TCP-style or UDP-style peeled-off socket in
707                  * sctp_wait_for_accept() or sctp_wait_for_packet().
708                  * For a UDP-style socket, the waiters are woken up by the
709                  * notifications.
710                  */
711                 if (!sctp_style(sk, UDP))
712                         sk->sk_state_change(sk);
713         }
714 }
715
716 /* Helper function to delete an association. */
717 static void sctp_cmd_delete_tcb(sctp_cmd_seq_t *cmds,
718                                 struct sctp_association *asoc)
719 {
720         struct sock *sk = asoc->base.sk;
721
722         /* If it is a non-temporary association belonging to a TCP-style
723          * listening socket that is not closed, do not free it so that accept() 
724          * can pick it up later.
725          */ 
726         if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
727             (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
728                 return;
729
730         sctp_unhash_established(asoc);
731         sctp_association_free(asoc);
732 }
733
734 /*
735  * ADDIP Section 4.1 ASCONF Chunk Procedures
736  * A4) Start a T-4 RTO timer, using the RTO value of the selected
737  * destination address (we use active path instead of primary path just
738  * because primary path may be inactive. 
739  */
740 static void sctp_cmd_setup_t4(sctp_cmd_seq_t *cmds,
741                                 struct sctp_association *asoc,
742                                 struct sctp_chunk *chunk)
743 {
744         struct sctp_transport *t;
745
746         t = asoc->peer.active_path;
747         asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
748         chunk->transport = t;
749 }
750
751 /* Process an incoming Operation Error Chunk. */ 
752 static void sctp_cmd_process_operr(sctp_cmd_seq_t *cmds,
753                                    struct sctp_association *asoc,
754                                    struct sctp_chunk *chunk)
755 {
756         struct sctp_operr_chunk *operr_chunk;
757         struct sctp_errhdr *err_hdr;
758
759         operr_chunk = (struct sctp_operr_chunk *)chunk->chunk_hdr;
760         err_hdr = &operr_chunk->err_hdr;
761
762         switch (err_hdr->cause) {
763         case SCTP_ERROR_UNKNOWN_CHUNK:
764         {
765                 struct sctp_chunkhdr *unk_chunk_hdr;
766
767                 unk_chunk_hdr = (struct sctp_chunkhdr *)err_hdr->variable;
768                 switch (unk_chunk_hdr->type) {
769                 /* ADDIP 4.1 A9) If the peer responds to an ASCONF with an
770                  * ERROR chunk reporting that it did not recognized the ASCONF
771                  * chunk type, the sender of the ASCONF MUST NOT send any
772                  * further ASCONF chunks and MUST stop its T-4 timer.
773                  */
774                 case SCTP_CID_ASCONF:
775                         asoc->peer.asconf_capable = 0;
776                         sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
777                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
778                         break;
779                 default:
780                         break;
781                 }
782                 break;
783         }
784         default:
785                 break;
786         }
787 }
788
789 /* Process variable FWDTSN chunk information. */
790 static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq, 
791                                     struct sctp_chunk *chunk)
792 {
793         struct sctp_fwdtsn_skip *skip;
794         /* Walk through all the skipped SSNs */
795         sctp_walk_fwdtsn(skip, chunk) {
796                 sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
797         }
798
799         return;
800 }
801
802 /* Helper function to remove the association non-primary peer 
803  * transports.
804  */ 
805 static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
806 {
807         struct sctp_transport *t;
808         struct list_head *pos;
809         struct list_head *temp;
810
811         list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
812                 t = list_entry(pos, struct sctp_transport, transports);
813                 if (!sctp_cmp_addr_exact(&t->ipaddr,
814                                          &asoc->peer.primary_addr)) {
815                         sctp_assoc_del_peer(asoc, &t->ipaddr);
816                 }
817         }
818
819         return;
820 }
821
822 /* These three macros allow us to pull the debugging code out of the
823  * main flow of sctp_do_sm() to keep attention focused on the real
824  * functionality there.
825  */
826 #define DEBUG_PRE \
827         SCTP_DEBUG_PRINTK("sctp_do_sm prefn: " \
828                           "ep %p, %s, %s, asoc %p[%s], %s\n", \
829                           ep, sctp_evttype_tbl[event_type], \
830                           (*debug_fn)(subtype), asoc, \
831                           sctp_state_tbl[state], state_fn->name)
832
833 #define DEBUG_POST \
834         SCTP_DEBUG_PRINTK("sctp_do_sm postfn: " \
835                           "asoc %p, status: %s\n", \
836                           asoc, sctp_status_tbl[status])
837
838 #define DEBUG_POST_SFX \
839         SCTP_DEBUG_PRINTK("sctp_do_sm post sfx: error %d, asoc %p[%s]\n", \
840                           error, asoc, \
841                           sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
842                           sctp_assoc2id(asoc)))?asoc->state:SCTP_STATE_CLOSED])
843
844 /*
845  * This is the master state machine processing function.
846  *
847  * If you want to understand all of lksctp, this is a
848  * good place to start.
849  */
850 int sctp_do_sm(sctp_event_t event_type, sctp_subtype_t subtype,
851                sctp_state_t state,
852                struct sctp_endpoint *ep,
853                struct sctp_association *asoc,
854                void *event_arg,
855                int gfp)
856 {
857         sctp_cmd_seq_t commands;
858         const sctp_sm_table_entry_t *state_fn;
859         sctp_disposition_t status;
860         int error = 0;
861         typedef const char *(printfn_t)(sctp_subtype_t);
862
863         static printfn_t *table[] = {
864                 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
865         };
866         printfn_t *debug_fn  __attribute__ ((unused)) = table[event_type];
867
868         /* Look up the state function, run it, and then process the
869          * side effects.  These three steps are the heart of lksctp.
870          */
871         state_fn = sctp_sm_lookup_event(event_type, state, subtype);
872
873         sctp_init_cmd_seq(&commands);
874
875         DEBUG_PRE;
876         status = (*state_fn->fn)(ep, asoc, subtype, event_arg, &commands);
877         DEBUG_POST;
878
879         error = sctp_side_effects(event_type, subtype, state,
880                                   ep, asoc, event_arg, status, 
881                                   &commands, gfp);
882         DEBUG_POST_SFX;
883
884         return error;
885 }
886
887 #undef DEBUG_PRE
888 #undef DEBUG_POST
889
890 /*****************************************************************
891  * This the master state function side effect processing function.
892  *****************************************************************/
893 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
894                              sctp_state_t state,
895                              struct sctp_endpoint *ep,
896                              struct sctp_association *asoc,
897                              void *event_arg,
898                              sctp_disposition_t status,
899                              sctp_cmd_seq_t *commands,
900                              int gfp)
901 {
902         int error;
903
904         /* FIXME - Most of the dispositions left today would be categorized
905          * as "exceptional" dispositions.  For those dispositions, it
906          * may not be proper to run through any of the commands at all.
907          * For example, the command interpreter might be run only with
908          * disposition SCTP_DISPOSITION_CONSUME.
909          */
910         if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
911                                                ep, asoc,
912                                                event_arg, status,
913                                                commands, gfp)))
914                 goto bail;
915
916         switch (status) {
917         case SCTP_DISPOSITION_DISCARD:
918                 SCTP_DEBUG_PRINTK("Ignored sctp protocol event - state %d, "
919                                   "event_type %d, event_id %d\n",
920                                   state, event_type, subtype.chunk);
921                 break;
922
923         case SCTP_DISPOSITION_NOMEM:
924                 /* We ran out of memory, so we need to discard this
925                  * packet.
926                  */
927                 /* BUG--we should now recover some memory, probably by
928                  * reneging...
929                  */
930                 error = -ENOMEM;
931                 break;
932
933         case SCTP_DISPOSITION_DELETE_TCB:
934                 /* This should now be a command. */
935                 break;
936
937         case SCTP_DISPOSITION_CONSUME:
938         case SCTP_DISPOSITION_ABORT:
939                 /*
940                  * We should no longer have much work to do here as the
941                  * real work has been done as explicit commands above.
942                  */
943                 break;
944
945         case SCTP_DISPOSITION_VIOLATION:
946                 printk(KERN_ERR "sctp protocol violation state %d "
947                        "chunkid %d\n", state, subtype.chunk);
948                 break;
949
950         case SCTP_DISPOSITION_NOT_IMPL:
951                 printk(KERN_WARNING "sctp unimplemented feature in state %d, "
952                        "event_type %d, event_id %d\n",
953                        state, event_type, subtype.chunk);
954                 break;
955
956         case SCTP_DISPOSITION_BUG:
957                 printk(KERN_ERR "sctp bug in state %d, "
958                        "event_type %d, event_id %d\n",
959                        state, event_type, subtype.chunk);
960                 BUG();
961                 break;
962
963         default:
964                 printk(KERN_ERR "sctp impossible disposition %d "
965                        "in state %d, event_type %d, event_id %d\n",
966                        status, state, event_type, subtype.chunk);
967                 BUG();
968                 break;
969         };
970
971 bail:
972         return error;
973 }
974
975 /********************************************************************
976  * 2nd Level Abstractions
977  ********************************************************************/
978
979 /* This is the side-effect interpreter.  */
980 static int sctp_cmd_interpreter(sctp_event_t event_type,
981                                 sctp_subtype_t subtype,
982                                 sctp_state_t state,
983                                 struct sctp_endpoint *ep,
984                                 struct sctp_association *asoc,
985                                 void *event_arg,
986                                 sctp_disposition_t status,
987                                 sctp_cmd_seq_t *commands,
988                                 int gfp)
989 {
990         int error = 0;
991         int force;
992         sctp_cmd_t *cmd;
993         struct sctp_chunk *new_obj;
994         struct sctp_chunk *chunk = NULL;
995         struct sctp_packet *packet;
996         struct list_head *pos;
997         struct timer_list *timer;
998         unsigned long timeout;
999         struct sctp_transport *t;
1000         struct sctp_sackhdr sackh;
1001         int local_cork = 0;
1002
1003         if (SCTP_EVENT_T_TIMEOUT != event_type)
1004                 chunk = (struct sctp_chunk *) event_arg;
1005
1006         /* Note:  This whole file is a huge candidate for rework.
1007          * For example, each command could either have its own handler, so
1008          * the loop would look like:
1009          *     while (cmds)
1010          *         cmd->handle(x, y, z)
1011          * --jgrimm
1012          */
1013         while (NULL != (cmd = sctp_next_cmd(commands))) {
1014                 switch (cmd->verb) {
1015                 case SCTP_CMD_NOP:
1016                         /* Do nothing. */
1017                         break;
1018
1019                 case SCTP_CMD_NEW_ASOC:
1020                         /* Register a new association.  */
1021                         if (local_cork) {
1022                                 sctp_outq_uncork(&asoc->outqueue); 
1023                                 local_cork = 0;
1024                         }
1025                         asoc = cmd->obj.ptr;
1026                         /* Register with the endpoint.  */
1027                         sctp_endpoint_add_asoc(ep, asoc);
1028                         sctp_hash_established(asoc);
1029                         break;
1030
1031                 case SCTP_CMD_UPDATE_ASSOC:
1032                        sctp_assoc_update(asoc, cmd->obj.ptr);
1033                        break;
1034
1035                 case SCTP_CMD_PURGE_OUTQUEUE:
1036                        sctp_outq_teardown(&asoc->outqueue);
1037                        break;
1038
1039                 case SCTP_CMD_DELETE_TCB:                       
1040                         if (local_cork) {
1041                                 sctp_outq_uncork(&asoc->outqueue);
1042                                 local_cork = 0;
1043                         }
1044                         /* Delete the current association.  */
1045                         sctp_cmd_delete_tcb(commands, asoc);
1046                         asoc = NULL;
1047                         break;
1048
1049                 case SCTP_CMD_NEW_STATE:
1050                         /* Enter a new state.  */
1051                         sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1052                         break;
1053
1054                 case SCTP_CMD_REPORT_TSN:
1055                         /* Record the arrival of a TSN.  */
1056                         sctp_tsnmap_mark(&asoc->peer.tsn_map, cmd->obj.u32);
1057                         break;
1058
1059                 case SCTP_CMD_REPORT_FWDTSN:
1060                         /* Move the Cumulattive TSN Ack ahead. */
1061                         sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32);
1062
1063                         /* Abort any in progress partial delivery. */
1064                         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
1065                         break;
1066
1067                 case SCTP_CMD_PROCESS_FWDTSN:
1068                         sctp_cmd_process_fwdtsn(&asoc->ulpq, cmd->obj.ptr);
1069                         break;
1070
1071                 case SCTP_CMD_GEN_SACK:
1072                         /* Generate a Selective ACK.
1073                          * The argument tells us whether to just count
1074                          * the packet and MAYBE generate a SACK, or
1075                          * force a SACK out.
1076                          */
1077                         force = cmd->obj.i32;
1078                         error = sctp_gen_sack(asoc, force, commands);
1079                         break;
1080
1081                 case SCTP_CMD_PROCESS_SACK:
1082                         /* Process an inbound SACK.  */
1083                         error = sctp_cmd_process_sack(commands, asoc,
1084                                                       cmd->obj.ptr);
1085                         break;
1086
1087                 case SCTP_CMD_GEN_INIT_ACK:
1088                         /* Generate an INIT ACK chunk.  */
1089                         new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1090                                                      0);
1091                         if (!new_obj)
1092                                 goto nomem;
1093
1094                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1095                                         SCTP_CHUNK(new_obj));
1096                         break;
1097
1098                 case SCTP_CMD_PEER_INIT:
1099                         /* Process a unified INIT from the peer.
1100                          * Note: Only used during INIT-ACK processing.  If
1101                          * there is an error just return to the outter
1102                          * layer which will bail.
1103                          */
1104                         error = sctp_cmd_process_init(commands, asoc, chunk,
1105                                                       cmd->obj.ptr, gfp);
1106                         break;
1107
1108                 case SCTP_CMD_GEN_COOKIE_ECHO:
1109                         /* Generate a COOKIE ECHO chunk.  */
1110                         new_obj = sctp_make_cookie_echo(asoc, chunk);
1111                         if (!new_obj) {
1112                                 if (cmd->obj.ptr)
1113                                         sctp_chunk_free(cmd->obj.ptr);
1114                                 goto nomem;
1115                         }
1116                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1117                                         SCTP_CHUNK(new_obj));
1118
1119                         /* If there is an ERROR chunk to be sent along with
1120                          * the COOKIE_ECHO, send it, too.
1121                          */
1122                         if (cmd->obj.ptr)
1123                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1124                                                 SCTP_CHUNK(cmd->obj.ptr));
1125
1126                         /* FIXME - Eventually come up with a cleaner way to
1127                          * enabling COOKIE-ECHO + DATA bundling during 
1128                          * multihoming stale cookie scenarios, the following 
1129                          * command plays with asoc->peer.retran_path to 
1130                          * avoid the problem of sending the COOKIE-ECHO and 
1131                          * DATA in different paths, which could result 
1132                          * in the association being ABORTed if the DATA chunk 
1133                          * is processed first by the server.  Checking the
1134                          * init error counter simply causes this command
1135                          * to be executed only during failed attempts of
1136                          * association establishment.
1137                          */
1138                         if ((asoc->peer.retran_path !=
1139                              asoc->peer.primary_path) &&
1140                             (asoc->init_err_counter > 0)) {
1141                                 sctp_add_cmd_sf(commands,
1142                                                 SCTP_CMD_FORCE_PRIM_RETRAN,
1143                                                 SCTP_NULL());
1144                         }
1145
1146                         break;
1147
1148                 case SCTP_CMD_GEN_SHUTDOWN:
1149                         /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1150                          * Reset error counts.
1151                          */
1152                         asoc->overall_error_count = 0;
1153
1154                         /* Generate a SHUTDOWN chunk.  */
1155                         new_obj = sctp_make_shutdown(asoc, chunk);
1156                         if (!new_obj)
1157                                 goto nomem;
1158                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1159                                         SCTP_CHUNK(new_obj));
1160                         break;
1161
1162                 case SCTP_CMD_CHUNK_ULP:
1163                         /* Send a chunk to the sockets layer.  */
1164                         SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1165                                           "chunk_up:", cmd->obj.ptr,
1166                                           "ulpq:", &asoc->ulpq);
1167                         sctp_ulpq_tail_data(&asoc->ulpq, cmd->obj.ptr,
1168                                             GFP_ATOMIC);
1169                         break;
1170
1171                 case SCTP_CMD_EVENT_ULP:
1172                         /* Send a notification to the sockets layer.  */
1173                         SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1174                                           "event_up:",cmd->obj.ptr,
1175                                           "ulpq:",&asoc->ulpq);
1176                         sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ptr);
1177                         break;
1178
1179                 case SCTP_CMD_REPLY:
1180                         /* If an caller has not already corked, do cork. */
1181                         if (!asoc->outqueue.cork) {
1182                                 sctp_outq_cork(&asoc->outqueue);
1183                                 local_cork = 1;
1184                         }
1185                         /* Send a chunk to our peer.  */
1186                         error = sctp_outq_tail(&asoc->outqueue, cmd->obj.ptr);
1187                         break;
1188
1189                 case SCTP_CMD_SEND_PKT:
1190                         /* Send a full packet to our peer.  */
1191                         packet = cmd->obj.ptr;
1192                         sctp_packet_transmit(packet);
1193                         sctp_ootb_pkt_free(packet);
1194                         break;
1195
1196                 case SCTP_CMD_RETRAN:
1197                         /* Mark a transport for retransmission.  */
1198                         sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1199                                         SCTP_RTXR_T3_RTX);
1200                         break;
1201
1202                 case SCTP_CMD_TRANSMIT:
1203                         /* Kick start transmission. */
1204                         error = sctp_outq_uncork(&asoc->outqueue);
1205                         local_cork = 0;
1206                         break;
1207
1208                 case SCTP_CMD_ECN_CE:
1209                         /* Do delayed CE processing.   */
1210                         sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1211                         break;
1212
1213                 case SCTP_CMD_ECN_ECNE:
1214                         /* Do delayed ECNE processing. */
1215                         new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1216                                                         chunk);
1217                         if (new_obj)
1218                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1219                                                 SCTP_CHUNK(new_obj));
1220                         break;
1221
1222                 case SCTP_CMD_ECN_CWR:
1223                         /* Do delayed CWR processing.  */
1224                         sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1225                         break;
1226
1227                 case SCTP_CMD_SETUP_T2:
1228                         sctp_cmd_setup_t2(commands, asoc, cmd->obj.ptr);
1229                         break;
1230
1231                 case SCTP_CMD_TIMER_START:
1232                         timer = &asoc->timers[cmd->obj.to];
1233                         timeout = asoc->timeouts[cmd->obj.to];
1234                         if (!timeout)
1235                                 BUG();
1236
1237                         timer->expires = jiffies + timeout;
1238                         sctp_association_hold(asoc);
1239                         add_timer(timer);
1240                         break;
1241
1242                 case SCTP_CMD_TIMER_RESTART:
1243                         timer = &asoc->timers[cmd->obj.to];
1244                         timeout = asoc->timeouts[cmd->obj.to];
1245                         if (!mod_timer(timer, jiffies + timeout))
1246                                 sctp_association_hold(asoc);
1247                         break;
1248
1249                 case SCTP_CMD_TIMER_STOP:
1250                         timer = &asoc->timers[cmd->obj.to];
1251                         if (timer_pending(timer) && del_timer(timer))
1252                                 sctp_association_put(asoc);
1253                         break;
1254
1255                 case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1256                         chunk = cmd->obj.ptr;
1257                         t = sctp_assoc_choose_init_transport(asoc);
1258                         asoc->init_last_sent_to = t;
1259                         chunk->transport = t;
1260                         t->init_sent_count++;
1261                         break;
1262
1263                 case SCTP_CMD_INIT_RESTART:
1264                         /* Do the needed accounting and updates
1265                          * associated with restarting an initialization
1266                          * timer. Only multiply the timeout by two if
1267                          * all transports have been tried at the current
1268                          * timeout.
1269                          */
1270                         t = asoc->init_last_sent_to;
1271                         asoc->init_err_counter++;
1272
1273                         if (t->init_sent_count > (asoc->init_cycle + 1)) {
1274                                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] *= 2;
1275                                 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] >
1276                                     asoc->max_init_timeo) {
1277                                         asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
1278                                                 asoc->max_init_timeo;
1279                                 }
1280                                 asoc->init_cycle++;
1281                                 SCTP_DEBUG_PRINTK(
1282                                         "T1 INIT Timeout adjustment"
1283                                         " init_err_counter: %d"
1284                                         " cycle: %d"
1285                                         " timeout: %d\n",
1286                                         asoc->init_err_counter,
1287                                         asoc->init_cycle,
1288                                         asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT]);
1289                         }
1290
1291                         sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1292                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1293                         break;
1294
1295                 case SCTP_CMD_COOKIEECHO_RESTART:
1296                         /* Do the needed accounting and updates
1297                          * associated with restarting an initialization
1298                          * timer. Only multiply the timeout by two if
1299                          * all transports have been tried at the current
1300                          * timeout.
1301                          */
1302                         asoc->init_err_counter++;
1303
1304                         asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] *= 2;
1305                         if (asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] >
1306                             asoc->max_init_timeo) {
1307                                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
1308                                         asoc->max_init_timeo;
1309                         }
1310                         SCTP_DEBUG_PRINTK(
1311                                 "T1 COOKIE Timeout adjustment"
1312                                 " init_err_counter: %d"
1313                                 " timeout: %d\n",
1314                                 asoc->init_err_counter,
1315                                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE]);
1316
1317                         /* If we've sent any data bundled with
1318                          * COOKIE-ECHO we need to resend.
1319                          */
1320                         list_for_each(pos, &asoc->peer.transport_addr_list) {
1321                                 t = list_entry(pos, struct sctp_transport,
1322                                                transports);
1323                                 sctp_retransmit_mark(&asoc->outqueue, t, 0);
1324                         }
1325
1326                         sctp_add_cmd_sf(commands,
1327                                         SCTP_CMD_TIMER_RESTART,
1328                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1329                         break;
1330
1331                 case SCTP_CMD_INIT_FAILED:
1332                         sctp_cmd_init_failed(commands, asoc, cmd->obj.u32);
1333                         break;
1334
1335                 case SCTP_CMD_ASSOC_FAILED:
1336                         sctp_cmd_assoc_failed(commands, asoc, event_type,
1337                                               subtype, chunk, cmd->obj.u32);
1338                         break;
1339
1340                 case SCTP_CMD_INIT_COUNTER_INC:
1341                         asoc->init_err_counter++;
1342                         break;
1343
1344                 case SCTP_CMD_INIT_COUNTER_RESET:
1345                         asoc->init_err_counter = 0;
1346                         asoc->init_cycle = 0;
1347                         break;
1348
1349                 case SCTP_CMD_REPORT_DUP:
1350                         sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1351                                              cmd->obj.u32);
1352                         break;
1353
1354                 case SCTP_CMD_REPORT_BAD_TAG:
1355                         SCTP_DEBUG_PRINTK("vtag mismatch!\n");
1356                         break;
1357
1358                 case SCTP_CMD_STRIKE:
1359                         /* Mark one strike against a transport.  */
1360                         sctp_do_8_2_transport_strike(asoc, cmd->obj.transport);
1361                         break;
1362
1363                 case SCTP_CMD_TRANSPORT_RESET:
1364                         t = cmd->obj.transport;
1365                         sctp_cmd_transport_reset(commands, asoc, t);
1366                         break;
1367
1368                 case SCTP_CMD_TRANSPORT_ON:
1369                         t = cmd->obj.transport;
1370                         sctp_cmd_transport_on(commands, asoc, t, chunk);
1371                         break;
1372
1373                 case SCTP_CMD_HB_TIMERS_START:
1374                         sctp_cmd_hb_timers_start(commands, asoc);
1375                         break;
1376
1377                 case SCTP_CMD_HB_TIMER_UPDATE:
1378                         t = cmd->obj.transport;
1379                         sctp_cmd_hb_timer_update(commands, asoc, t);
1380                         break;
1381
1382                 case SCTP_CMD_HB_TIMERS_STOP:
1383                         sctp_cmd_hb_timers_stop(commands, asoc);
1384                         break;
1385
1386                 case SCTP_CMD_REPORT_ERROR:
1387                         error = cmd->obj.error;
1388                         break;
1389
1390                 case SCTP_CMD_PROCESS_CTSN:
1391                         /* Dummy up a SACK for processing. */
1392                         sackh.cum_tsn_ack = cmd->obj.u32;
1393                         sackh.a_rwnd = 0;
1394                         sackh.num_gap_ack_blocks = 0;
1395                         sackh.num_dup_tsns = 0;
1396                         sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1397                                         SCTP_SACKH(&sackh));
1398                         break;
1399
1400                 case SCTP_CMD_DISCARD_PACKET:
1401                         /* We need to discard the whole packet.  */
1402                         chunk->pdiscard = 1;
1403                         break;
1404
1405                 case SCTP_CMD_RTO_PENDING:
1406                         t = cmd->obj.transport;
1407                         t->rto_pending = 1;
1408                         break;
1409
1410                 case SCTP_CMD_PART_DELIVER:
1411                         sctp_ulpq_partial_delivery(&asoc->ulpq, cmd->obj.ptr,
1412                                                    GFP_ATOMIC);
1413                         break;
1414
1415                 case SCTP_CMD_RENEGE:
1416                         sctp_ulpq_renege(&asoc->ulpq, cmd->obj.ptr,
1417                                          GFP_ATOMIC);
1418                         break;
1419
1420                 case SCTP_CMD_SETUP_T4:
1421                         sctp_cmd_setup_t4(commands, asoc, cmd->obj.ptr);
1422                         break;
1423
1424                 case SCTP_CMD_PROCESS_OPERR:
1425                         sctp_cmd_process_operr(commands, asoc, chunk);
1426                         break;
1427                 case SCTP_CMD_CLEAR_INIT_TAG:
1428                         asoc->peer.i.init_tag = 0;
1429                         break;
1430                 case SCTP_CMD_DEL_NON_PRIMARY:
1431                         sctp_cmd_del_non_primary(asoc);
1432                         break;
1433                 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1434                         sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1435                         break;
1436                 case SCTP_CMD_FORCE_PRIM_RETRAN:
1437                         t = asoc->peer.retran_path;
1438                         asoc->peer.retran_path = asoc->peer.primary_path;
1439                         error = sctp_outq_uncork(&asoc->outqueue);
1440                         local_cork = 0;
1441                         asoc->peer.retran_path = t;
1442                         break;
1443                 default:
1444                         printk(KERN_WARNING "Impossible command: %u, %p\n",
1445                                cmd->verb, cmd->obj.ptr);
1446                         break;
1447                 };
1448                 if (error)
1449                         break;
1450         }
1451
1452 out:
1453         if (local_cork)
1454                 sctp_outq_uncork(&asoc->outqueue);
1455         return error;
1456 nomem:
1457         error = -ENOMEM;
1458         goto out;
1459 }
1460