Merge master.kernel.org:/pub/scm/linux/kernel/git/davej/agpgart
[linux-2.6] / 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                                 gfp_t 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                              gfp_t 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         struct sctp_transport *trans = asoc->peer.last_data_from;
161         int error = 0;
162
163         if (force ||
164             (!trans && (asoc->param_flags & SPP_SACKDELAY_DISABLE)) ||
165             (trans && (trans->param_flags & SPP_SACKDELAY_DISABLE)))
166                 asoc->peer.sack_needed = 1;
167
168         ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
169         max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
170
171         /* From 12.2 Parameters necessary per association (i.e. the TCB):
172          *
173          * Ack State : This flag indicates if the next received packet
174          *           : is to be responded to with a SACK. ...
175          *           : When DATA chunks are out of order, SACK's
176          *           : are not delayed (see Section 6).
177          *
178          * [This is actually not mentioned in Section 6, but we
179          * implement it here anyway. --piggy]
180          */
181         if (max_tsn_seen != ctsn)
182                 asoc->peer.sack_needed = 1;
183
184         /* From 6.2  Acknowledgement on Reception of DATA Chunks:
185          *
186          * Section 4.2 of [RFC2581] SHOULD be followed. Specifically,
187          * an acknowledgement SHOULD be generated for at least every
188          * second packet (not every second DATA chunk) received, and
189          * SHOULD be generated within 200 ms of the arrival of any
190          * unacknowledged DATA chunk. ...
191          */
192         if (!asoc->peer.sack_needed) {
193                 /* We will need a SACK for the next packet.  */
194                 asoc->peer.sack_needed = 1;
195
196                 /* Set the SACK delay timeout based on the
197                  * SACK delay for the last transport
198                  * data was received from, or the default
199                  * for the association.
200                  */
201                 if (trans)
202                         asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
203                                 trans->sackdelay;
204                 else
205                         asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
206                                 asoc->sackdelay;
207
208                 /* Restart the SACK timer. */
209                 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
210                                 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
211         } else {
212                 if (asoc->a_rwnd > asoc->rwnd)
213                         asoc->a_rwnd = asoc->rwnd;
214                 sack = sctp_make_sack(asoc);
215                 if (!sack)
216                         goto nomem;
217
218                 asoc->peer.sack_needed = 0;
219
220                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(sack));
221
222                 /* Stop the SACK timer.  */
223                 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
224                                 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
225         }
226
227         return error;
228 nomem:
229         error = -ENOMEM;
230         return error;
231 }
232
233 /* When the T3-RTX timer expires, it calls this function to create the
234  * relevant state machine event.
235  */
236 void sctp_generate_t3_rtx_event(unsigned long peer)
237 {
238         int error;
239         struct sctp_transport *transport = (struct sctp_transport *) peer;
240         struct sctp_association *asoc = transport->asoc;
241
242         /* Check whether a task is in the sock.  */
243
244         sctp_bh_lock_sock(asoc->base.sk);
245         if (sock_owned_by_user(asoc->base.sk)) {
246                 SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __FUNCTION__);
247
248                 /* Try again later.  */
249                 if (!mod_timer(&transport->T3_rtx_timer, jiffies + (HZ/20)))
250                         sctp_transport_hold(transport);
251                 goto out_unlock;
252         }
253
254         /* Is this transport really dead and just waiting around for
255          * the timer to let go of the reference?
256          */
257         if (transport->dead)
258                 goto out_unlock;
259
260         /* Run through the state machine.  */
261         error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
262                            SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX),
263                            asoc->state,
264                            asoc->ep, asoc,
265                            transport, GFP_ATOMIC);
266
267         if (error)
268                 asoc->base.sk->sk_err = -error;
269
270 out_unlock:
271         sctp_bh_unlock_sock(asoc->base.sk);
272         sctp_transport_put(transport);
273 }
274
275 /* This is a sa interface for producing timeout events.  It works
276  * for timeouts which use the association as their parameter.
277  */
278 static void sctp_generate_timeout_event(struct sctp_association *asoc,
279                                         sctp_event_timeout_t timeout_type)
280 {
281         int error = 0;
282
283         sctp_bh_lock_sock(asoc->base.sk);
284         if (sock_owned_by_user(asoc->base.sk)) {
285                 SCTP_DEBUG_PRINTK("%s:Sock is busy: timer %d\n",
286                                   __FUNCTION__,
287                                   timeout_type);
288
289                 /* Try again later.  */
290                 if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20)))
291                         sctp_association_hold(asoc);
292                 goto out_unlock;
293         }
294
295         /* Is this association really dead and just waiting around for
296          * the timer to let go of the reference?
297          */
298         if (asoc->base.dead)
299                 goto out_unlock;
300
301         /* Run through the state machine.  */
302         error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
303                            SCTP_ST_TIMEOUT(timeout_type),
304                            asoc->state, asoc->ep, asoc,
305                            (void *)timeout_type, GFP_ATOMIC);
306
307         if (error)
308                 asoc->base.sk->sk_err = -error;
309
310 out_unlock:
311         sctp_bh_unlock_sock(asoc->base.sk);
312         sctp_association_put(asoc);
313 }
314
315 static void sctp_generate_t1_cookie_event(unsigned long data)
316 {
317         struct sctp_association *asoc = (struct sctp_association *) data;
318         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
319 }
320
321 static void sctp_generate_t1_init_event(unsigned long data)
322 {
323         struct sctp_association *asoc = (struct sctp_association *) data;
324         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
325 }
326
327 static void sctp_generate_t2_shutdown_event(unsigned long data)
328 {
329         struct sctp_association *asoc = (struct sctp_association *) data;
330         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
331 }
332
333 static void sctp_generate_t4_rto_event(unsigned long data)
334 {
335         struct sctp_association *asoc = (struct sctp_association *) data;
336         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
337 }
338
339 static void sctp_generate_t5_shutdown_guard_event(unsigned long data)
340 {
341         struct sctp_association *asoc = (struct sctp_association *)data;
342         sctp_generate_timeout_event(asoc,
343                                     SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);
344
345 } /* sctp_generate_t5_shutdown_guard_event() */
346
347 static void sctp_generate_autoclose_event(unsigned long data)
348 {
349         struct sctp_association *asoc = (struct sctp_association *) data;
350         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE);
351 }
352
353 /* Generate a heart beat event.  If the sock is busy, reschedule.   Make
354  * sure that the transport is still valid.
355  */
356 void sctp_generate_heartbeat_event(unsigned long data)
357 {
358         int error = 0;
359         struct sctp_transport *transport = (struct sctp_transport *) data;
360         struct sctp_association *asoc = transport->asoc;
361
362         sctp_bh_lock_sock(asoc->base.sk);
363         if (sock_owned_by_user(asoc->base.sk)) {
364                 SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __FUNCTION__);
365
366                 /* Try again later.  */
367                 if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20)))
368                         sctp_transport_hold(transport);
369                 goto out_unlock;
370         }
371
372         /* Is this structure just waiting around for us to actually
373          * get destroyed?
374          */
375         if (transport->dead)
376                 goto out_unlock;
377
378         error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
379                            SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
380                            asoc->state, asoc->ep, asoc,
381                            transport, GFP_ATOMIC);
382
383          if (error)
384                  asoc->base.sk->sk_err = -error;
385
386 out_unlock:
387         sctp_bh_unlock_sock(asoc->base.sk);
388         sctp_transport_put(transport);
389 }
390
391 /* Inject a SACK Timeout event into the state machine.  */
392 static void sctp_generate_sack_event(unsigned long data)
393 {
394         struct sctp_association *asoc = (struct sctp_association *) data;
395         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
396 }
397
398 sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
399         NULL,
400         sctp_generate_t1_cookie_event,
401         sctp_generate_t1_init_event,
402         sctp_generate_t2_shutdown_event,
403         NULL,
404         sctp_generate_t4_rto_event,
405         sctp_generate_t5_shutdown_guard_event,
406         NULL,
407         sctp_generate_sack_event,
408         sctp_generate_autoclose_event,
409 };
410
411
412 /* RFC 2960 8.2 Path Failure Detection
413  *
414  * When its peer endpoint is multi-homed, an endpoint should keep a
415  * error counter for each of the destination transport addresses of the
416  * peer endpoint.
417  *
418  * Each time the T3-rtx timer expires on any address, or when a
419  * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
420  * the error counter of that destination address will be incremented.
421  * When the value in the error counter exceeds the protocol parameter
422  * 'Path.Max.Retrans' of that destination address, the endpoint should
423  * mark the destination transport address as inactive, and a
424  * notification SHOULD be sent to the upper layer.
425  *
426  */
427 static void sctp_do_8_2_transport_strike(struct sctp_association *asoc,
428                                          struct sctp_transport *transport)
429 {
430         /* The check for association's overall error counter exceeding the
431          * threshold is done in the state function.
432          */
433         /* When probing UNCONFIRMED addresses, the association overall
434          * error count is NOT incremented
435          */
436         if (transport->state != SCTP_UNCONFIRMED)
437                 asoc->overall_error_count++;
438
439         if (transport->state != SCTP_INACTIVE &&
440             (transport->error_count++ >= transport->pathmaxrxt)) {
441                 SCTP_DEBUG_PRINTK_IPADDR("transport_strike:association %p",
442                                          " transport IP: port:%d failed.\n",
443                                          asoc,
444                                          (&transport->ipaddr),
445                                          ntohs(transport->ipaddr.v4.sin_port));
446                 sctp_assoc_control_transport(asoc, transport,
447                                              SCTP_TRANSPORT_DOWN,
448                                              SCTP_FAILED_THRESHOLD);
449         }
450
451         /* E2) For the destination address for which the timer
452          * expires, set RTO <- RTO * 2 ("back off the timer").  The
453          * maximum value discussed in rule C7 above (RTO.max) may be
454          * used to provide an upper bound to this doubling operation.
455          */
456         transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
457 }
458
459 /* Worker routine to handle INIT command failure.  */
460 static void sctp_cmd_init_failed(sctp_cmd_seq_t *commands,
461                                  struct sctp_association *asoc,
462                                  unsigned error)
463 {
464         struct sctp_ulpevent *event;
465
466         event = sctp_ulpevent_make_assoc_change(asoc,0, SCTP_CANT_STR_ASSOC,
467                                                 (__u16)error, 0, 0,
468                                                 GFP_ATOMIC);
469
470         if (event)
471                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
472                                 SCTP_ULPEVENT(event));
473
474         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
475                         SCTP_STATE(SCTP_STATE_CLOSED));
476
477         /* SEND_FAILED sent later when cleaning up the association. */
478         asoc->outqueue.error = error;
479         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
480 }
481
482 /* Worker routine to handle SCTP_CMD_ASSOC_FAILED.  */
483 static void sctp_cmd_assoc_failed(sctp_cmd_seq_t *commands,
484                                   struct sctp_association *asoc,
485                                   sctp_event_t event_type,
486                                   sctp_subtype_t subtype,
487                                   struct sctp_chunk *chunk,
488                                   unsigned error)
489 {
490         struct sctp_ulpevent *event;
491
492         /* Cancel any partial delivery in progress. */
493         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
494
495         event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
496                                                 (__u16)error, 0, 0,
497                                                 GFP_ATOMIC);
498         if (event)
499                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
500                                 SCTP_ULPEVENT(event));
501
502         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
503                         SCTP_STATE(SCTP_STATE_CLOSED));
504
505         /* SEND_FAILED sent later when cleaning up the association. */
506         asoc->outqueue.error = error;
507         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
508 }
509
510 /* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
511  * inside the cookie.  In reality, this is only used for INIT-ACK processing
512  * since all other cases use "temporary" associations and can do all
513  * their work in statefuns directly.
514  */
515 static int sctp_cmd_process_init(sctp_cmd_seq_t *commands,
516                                  struct sctp_association *asoc,
517                                  struct sctp_chunk *chunk,
518                                  sctp_init_chunk_t *peer_init,
519                                  gfp_t gfp)
520 {
521         int error;
522
523         /* We only process the init as a sideeffect in a single
524          * case.   This is when we process the INIT-ACK.   If we
525          * fail during INIT processing (due to malloc problems),
526          * just return the error and stop processing the stack.
527          */
528         if (!sctp_process_init(asoc, chunk->chunk_hdr->type,
529                                sctp_source(chunk), peer_init, gfp))
530                 error = -ENOMEM;
531         else
532                 error = 0;
533
534         return error;
535 }
536
537 /* Helper function to break out starting up of heartbeat timers.  */
538 static void sctp_cmd_hb_timers_start(sctp_cmd_seq_t *cmds,
539                                      struct sctp_association *asoc)
540 {
541         struct sctp_transport *t;
542         struct list_head *pos;
543
544         /* Start a heartbeat timer for each transport on the association.
545          * hold a reference on the transport to make sure none of
546          * the needed data structures go away.
547          */
548         list_for_each(pos, &asoc->peer.transport_addr_list) {
549                 t = list_entry(pos, struct sctp_transport, transports);
550
551                 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
552                         sctp_transport_hold(t);
553         }
554 }
555
556 static void sctp_cmd_hb_timers_stop(sctp_cmd_seq_t *cmds,
557                                     struct sctp_association *asoc)
558 {
559         struct sctp_transport *t;
560         struct list_head *pos;
561
562         /* Stop all heartbeat timers. */
563
564         list_for_each(pos, &asoc->peer.transport_addr_list) {
565                 t = list_entry(pos, struct sctp_transport, transports);
566                 if (del_timer(&t->hb_timer))
567                         sctp_transport_put(t);
568         }
569 }
570
571 /* Helper function to stop any pending T3-RTX timers */
572 static void sctp_cmd_t3_rtx_timers_stop(sctp_cmd_seq_t *cmds,
573                                         struct sctp_association *asoc)
574 {
575         struct sctp_transport *t;
576         struct list_head *pos;
577
578         list_for_each(pos, &asoc->peer.transport_addr_list) {
579                 t = list_entry(pos, struct sctp_transport, transports);
580                 if (timer_pending(&t->T3_rtx_timer) &&
581                     del_timer(&t->T3_rtx_timer)) {
582                         sctp_transport_put(t);
583                 }
584         }
585 }
586
587
588 /* Helper function to update the heartbeat timer. */
589 static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
590                                      struct sctp_association *asoc,
591                                      struct sctp_transport *t)
592 {
593         /* Update the heartbeat timer.  */
594         if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
595                 sctp_transport_hold(t);
596 }
597
598 /* Helper function to handle the reception of an HEARTBEAT ACK.  */
599 static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds,
600                                   struct sctp_association *asoc,
601                                   struct sctp_transport *t,
602                                   struct sctp_chunk *chunk)
603 {
604         sctp_sender_hb_info_t *hbinfo;
605
606         /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
607          * HEARTBEAT should clear the error counter of the destination
608          * transport address to which the HEARTBEAT was sent.
609          * The association's overall error count is also cleared.
610          */
611         t->error_count = 0;
612         t->asoc->overall_error_count = 0;
613
614         /* Mark the destination transport address as active if it is not so
615          * marked.
616          */
617         if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED))
618                 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
619                                              SCTP_HEARTBEAT_SUCCESS);
620
621         /* The receiver of the HEARTBEAT ACK should also perform an
622          * RTT measurement for that destination transport address
623          * using the time value carried in the HEARTBEAT ACK chunk.
624          * If the transport's rto_pending variable has been cleared,
625          * it was most likely due to a retransmit.  However, we want
626          * to re-enable it to properly update the rto.
627          */
628         if (t->rto_pending == 0)
629                 t->rto_pending = 1;
630
631         hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
632         sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
633
634         /* Update the heartbeat timer.  */
635         if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
636                 sctp_transport_hold(t);
637 }
638
639 /* Helper function to do a transport reset at the expiry of the hearbeat
640  * timer.
641  */
642 static void sctp_cmd_transport_reset(sctp_cmd_seq_t *cmds,
643                                      struct sctp_association *asoc,
644                                      struct sctp_transport *t)
645 {
646         sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
647
648         /* Mark one strike against a transport.  */
649         sctp_do_8_2_transport_strike(asoc, t);
650 }
651
652 /* Helper function to process the process SACK command.  */
653 static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds,
654                                  struct sctp_association *asoc,
655                                  struct sctp_sackhdr *sackh)
656 {
657         int err;
658
659         if (sctp_outq_sack(&asoc->outqueue, sackh)) {
660                 /* There are no more TSNs awaiting SACK.  */
661                 err = sctp_do_sm(SCTP_EVENT_T_OTHER,
662                                  SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
663                                  asoc->state, asoc->ep, asoc, NULL,
664                                  GFP_ATOMIC);
665         } else {
666                 /* Windows may have opened, so we need
667                  * to check if we have DATA to transmit
668                  */
669                 err = sctp_outq_flush(&asoc->outqueue, 0);
670         }
671
672         return err;
673 }
674
675 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
676  * the transport for a shutdown chunk.
677  */
678 static void sctp_cmd_setup_t2(sctp_cmd_seq_t *cmds,
679                               struct sctp_association *asoc,
680                               struct sctp_chunk *chunk)
681 {
682         struct sctp_transport *t;
683
684         t = sctp_assoc_choose_shutdown_transport(asoc);
685         asoc->shutdown_last_sent_to = t;
686         asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
687         chunk->transport = t;
688 }
689
690 /* Helper function to change the state of an association. */
691 static void sctp_cmd_new_state(sctp_cmd_seq_t *cmds,
692                                struct sctp_association *asoc,
693                                sctp_state_t state)
694 {
695         struct sock *sk = asoc->base.sk;
696
697         asoc->state = state;
698
699         SCTP_DEBUG_PRINTK("sctp_cmd_new_state: asoc %p[%s]\n",
700                           asoc, sctp_state_tbl[state]);
701
702         if (sctp_style(sk, TCP)) {
703                 /* Change the sk->sk_state of a TCP-style socket that has
704                  * sucessfully completed a connect() call.
705                  */
706                 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
707                         sk->sk_state = SCTP_SS_ESTABLISHED;
708
709                 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
710                 if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
711                     sctp_sstate(sk, ESTABLISHED))
712                         sk->sk_shutdown |= RCV_SHUTDOWN;
713         }
714
715         if (sctp_state(asoc, COOKIE_WAIT)) {
716                 /* Reset init timeouts since they may have been
717                  * increased due to timer expirations.
718                  */
719                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
720                                                 asoc->rto_initial;
721                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
722                                                 asoc->rto_initial;
723         }
724
725         if (sctp_state(asoc, ESTABLISHED) ||
726             sctp_state(asoc, CLOSED) ||
727             sctp_state(asoc, SHUTDOWN_RECEIVED)) {
728                 /* Wake up any processes waiting in the asoc's wait queue in
729                  * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
730                  */
731                 if (waitqueue_active(&asoc->wait))
732                         wake_up_interruptible(&asoc->wait);
733
734                 /* Wake up any processes waiting in the sk's sleep queue of
735                  * a TCP-style or UDP-style peeled-off socket in
736                  * sctp_wait_for_accept() or sctp_wait_for_packet().
737                  * For a UDP-style socket, the waiters are woken up by the
738                  * notifications.
739                  */
740                 if (!sctp_style(sk, UDP))
741                         sk->sk_state_change(sk);
742         }
743 }
744
745 /* Helper function to delete an association. */
746 static void sctp_cmd_delete_tcb(sctp_cmd_seq_t *cmds,
747                                 struct sctp_association *asoc)
748 {
749         struct sock *sk = asoc->base.sk;
750
751         /* If it is a non-temporary association belonging to a TCP-style
752          * listening socket that is not closed, do not free it so that accept()
753          * can pick it up later.
754          */
755         if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
756             (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
757                 return;
758
759         sctp_unhash_established(asoc);
760         sctp_association_free(asoc);
761 }
762
763 /*
764  * ADDIP Section 4.1 ASCONF Chunk Procedures
765  * A4) Start a T-4 RTO timer, using the RTO value of the selected
766  * destination address (we use active path instead of primary path just
767  * because primary path may be inactive.
768  */
769 static void sctp_cmd_setup_t4(sctp_cmd_seq_t *cmds,
770                                 struct sctp_association *asoc,
771                                 struct sctp_chunk *chunk)
772 {
773         struct sctp_transport *t;
774
775         t = asoc->peer.active_path;
776         asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
777         chunk->transport = t;
778 }
779
780 /* Process an incoming Operation Error Chunk. */
781 static void sctp_cmd_process_operr(sctp_cmd_seq_t *cmds,
782                                    struct sctp_association *asoc,
783                                    struct sctp_chunk *chunk)
784 {
785         struct sctp_operr_chunk *operr_chunk;
786         struct sctp_errhdr *err_hdr;
787
788         operr_chunk = (struct sctp_operr_chunk *)chunk->chunk_hdr;
789         err_hdr = &operr_chunk->err_hdr;
790
791         switch (err_hdr->cause) {
792         case SCTP_ERROR_UNKNOWN_CHUNK:
793         {
794                 struct sctp_chunkhdr *unk_chunk_hdr;
795
796                 unk_chunk_hdr = (struct sctp_chunkhdr *)err_hdr->variable;
797                 switch (unk_chunk_hdr->type) {
798                 /* ADDIP 4.1 A9) If the peer responds to an ASCONF with an
799                  * ERROR chunk reporting that it did not recognized the ASCONF
800                  * chunk type, the sender of the ASCONF MUST NOT send any
801                  * further ASCONF chunks and MUST stop its T-4 timer.
802                  */
803                 case SCTP_CID_ASCONF:
804                         asoc->peer.asconf_capable = 0;
805                         sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
806                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
807                         break;
808                 default:
809                         break;
810                 }
811                 break;
812         }
813         default:
814                 break;
815         }
816 }
817
818 /* Process variable FWDTSN chunk information. */
819 static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq,
820                                     struct sctp_chunk *chunk)
821 {
822         struct sctp_fwdtsn_skip *skip;
823         /* Walk through all the skipped SSNs */
824         sctp_walk_fwdtsn(skip, chunk) {
825                 sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
826         }
827
828         return;
829 }
830
831 /* Helper function to remove the association non-primary peer
832  * transports.
833  */
834 static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
835 {
836         struct sctp_transport *t;
837         struct list_head *pos;
838         struct list_head *temp;
839
840         list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
841                 t = list_entry(pos, struct sctp_transport, transports);
842                 if (!sctp_cmp_addr_exact(&t->ipaddr,
843                                          &asoc->peer.primary_addr)) {
844                         sctp_assoc_del_peer(asoc, &t->ipaddr);
845                 }
846         }
847
848         return;
849 }
850
851 /* Helper function to set sk_err on a 1-1 style socket. */
852 static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
853 {
854         struct sock *sk = asoc->base.sk;
855
856         if (!sctp_style(sk, UDP))
857                 sk->sk_err = error;
858 }
859
860 /* These three macros allow us to pull the debugging code out of the
861  * main flow of sctp_do_sm() to keep attention focused on the real
862  * functionality there.
863  */
864 #define DEBUG_PRE \
865         SCTP_DEBUG_PRINTK("sctp_do_sm prefn: " \
866                           "ep %p, %s, %s, asoc %p[%s], %s\n", \
867                           ep, sctp_evttype_tbl[event_type], \
868                           (*debug_fn)(subtype), asoc, \
869                           sctp_state_tbl[state], state_fn->name)
870
871 #define DEBUG_POST \
872         SCTP_DEBUG_PRINTK("sctp_do_sm postfn: " \
873                           "asoc %p, status: %s\n", \
874                           asoc, sctp_status_tbl[status])
875
876 #define DEBUG_POST_SFX \
877         SCTP_DEBUG_PRINTK("sctp_do_sm post sfx: error %d, asoc %p[%s]\n", \
878                           error, asoc, \
879                           sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
880                           sctp_assoc2id(asoc)))?asoc->state:SCTP_STATE_CLOSED])
881
882 /*
883  * This is the master state machine processing function.
884  *
885  * If you want to understand all of lksctp, this is a
886  * good place to start.
887  */
888 int sctp_do_sm(sctp_event_t event_type, sctp_subtype_t subtype,
889                sctp_state_t state,
890                struct sctp_endpoint *ep,
891                struct sctp_association *asoc,
892                void *event_arg,
893                gfp_t gfp)
894 {
895         sctp_cmd_seq_t commands;
896         const sctp_sm_table_entry_t *state_fn;
897         sctp_disposition_t status;
898         int error = 0;
899         typedef const char *(printfn_t)(sctp_subtype_t);
900
901         static printfn_t *table[] = {
902                 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
903         };
904         printfn_t *debug_fn  __attribute__ ((unused)) = table[event_type];
905
906         /* Look up the state function, run it, and then process the
907          * side effects.  These three steps are the heart of lksctp.
908          */
909         state_fn = sctp_sm_lookup_event(event_type, state, subtype);
910
911         sctp_init_cmd_seq(&commands);
912
913         DEBUG_PRE;
914         status = (*state_fn->fn)(ep, asoc, subtype, event_arg, &commands);
915         DEBUG_POST;
916
917         error = sctp_side_effects(event_type, subtype, state,
918                                   ep, asoc, event_arg, status,
919                                   &commands, gfp);
920         DEBUG_POST_SFX;
921
922         return error;
923 }
924
925 #undef DEBUG_PRE
926 #undef DEBUG_POST
927
928 /*****************************************************************
929  * This the master state function side effect processing function.
930  *****************************************************************/
931 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
932                              sctp_state_t state,
933                              struct sctp_endpoint *ep,
934                              struct sctp_association *asoc,
935                              void *event_arg,
936                              sctp_disposition_t status,
937                              sctp_cmd_seq_t *commands,
938                              gfp_t gfp)
939 {
940         int error;
941
942         /* FIXME - Most of the dispositions left today would be categorized
943          * as "exceptional" dispositions.  For those dispositions, it
944          * may not be proper to run through any of the commands at all.
945          * For example, the command interpreter might be run only with
946          * disposition SCTP_DISPOSITION_CONSUME.
947          */
948         if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
949                                                ep, asoc,
950                                                event_arg, status,
951                                                commands, gfp)))
952                 goto bail;
953
954         switch (status) {
955         case SCTP_DISPOSITION_DISCARD:
956                 SCTP_DEBUG_PRINTK("Ignored sctp protocol event - state %d, "
957                                   "event_type %d, event_id %d\n",
958                                   state, event_type, subtype.chunk);
959                 break;
960
961         case SCTP_DISPOSITION_NOMEM:
962                 /* We ran out of memory, so we need to discard this
963                  * packet.
964                  */
965                 /* BUG--we should now recover some memory, probably by
966                  * reneging...
967                  */
968                 error = -ENOMEM;
969                 break;
970
971         case SCTP_DISPOSITION_DELETE_TCB:
972                 /* This should now be a command. */
973                 break;
974
975         case SCTP_DISPOSITION_CONSUME:
976         case SCTP_DISPOSITION_ABORT:
977                 /*
978                  * We should no longer have much work to do here as the
979                  * real work has been done as explicit commands above.
980                  */
981                 break;
982
983         case SCTP_DISPOSITION_VIOLATION:
984                 printk(KERN_ERR "sctp protocol violation state %d "
985                        "chunkid %d\n", state, subtype.chunk);
986                 break;
987
988         case SCTP_DISPOSITION_NOT_IMPL:
989                 printk(KERN_WARNING "sctp unimplemented feature in state %d, "
990                        "event_type %d, event_id %d\n",
991                        state, event_type, subtype.chunk);
992                 break;
993
994         case SCTP_DISPOSITION_BUG:
995                 printk(KERN_ERR "sctp bug in state %d, "
996                        "event_type %d, event_id %d\n",
997                        state, event_type, subtype.chunk);
998                 BUG();
999                 break;
1000
1001         default:
1002                 printk(KERN_ERR "sctp impossible disposition %d "
1003                        "in state %d, event_type %d, event_id %d\n",
1004                        status, state, event_type, subtype.chunk);
1005                 BUG();
1006                 break;
1007         };
1008
1009 bail:
1010         return error;
1011 }
1012
1013 /********************************************************************
1014  * 2nd Level Abstractions
1015  ********************************************************************/
1016
1017 /* This is the side-effect interpreter.  */
1018 static int sctp_cmd_interpreter(sctp_event_t event_type,
1019                                 sctp_subtype_t subtype,
1020                                 sctp_state_t state,
1021                                 struct sctp_endpoint *ep,
1022                                 struct sctp_association *asoc,
1023                                 void *event_arg,
1024                                 sctp_disposition_t status,
1025                                 sctp_cmd_seq_t *commands,
1026                                 gfp_t gfp)
1027 {
1028         int error = 0;
1029         int force;
1030         sctp_cmd_t *cmd;
1031         struct sctp_chunk *new_obj;
1032         struct sctp_chunk *chunk = NULL;
1033         struct sctp_packet *packet;
1034         struct list_head *pos;
1035         struct timer_list *timer;
1036         unsigned long timeout;
1037         struct sctp_transport *t;
1038         struct sctp_sackhdr sackh;
1039         int local_cork = 0;
1040
1041         if (SCTP_EVENT_T_TIMEOUT != event_type)
1042                 chunk = (struct sctp_chunk *) event_arg;
1043
1044         /* Note:  This whole file is a huge candidate for rework.
1045          * For example, each command could either have its own handler, so
1046          * the loop would look like:
1047          *     while (cmds)
1048          *         cmd->handle(x, y, z)
1049          * --jgrimm
1050          */
1051         while (NULL != (cmd = sctp_next_cmd(commands))) {
1052                 switch (cmd->verb) {
1053                 case SCTP_CMD_NOP:
1054                         /* Do nothing. */
1055                         break;
1056
1057                 case SCTP_CMD_NEW_ASOC:
1058                         /* Register a new association.  */
1059                         if (local_cork) {
1060                                 sctp_outq_uncork(&asoc->outqueue);
1061                                 local_cork = 0;
1062                         }
1063                         asoc = cmd->obj.ptr;
1064                         /* Register with the endpoint.  */
1065                         sctp_endpoint_add_asoc(ep, asoc);
1066                         sctp_hash_established(asoc);
1067                         break;
1068
1069                 case SCTP_CMD_UPDATE_ASSOC:
1070                        sctp_assoc_update(asoc, cmd->obj.ptr);
1071                        break;
1072
1073                 case SCTP_CMD_PURGE_OUTQUEUE:
1074                        sctp_outq_teardown(&asoc->outqueue);
1075                        break;
1076
1077                 case SCTP_CMD_DELETE_TCB:
1078                         if (local_cork) {
1079                                 sctp_outq_uncork(&asoc->outqueue);
1080                                 local_cork = 0;
1081                         }
1082                         /* Delete the current association.  */
1083                         sctp_cmd_delete_tcb(commands, asoc);
1084                         asoc = NULL;
1085                         break;
1086
1087                 case SCTP_CMD_NEW_STATE:
1088                         /* Enter a new state.  */
1089                         sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1090                         break;
1091
1092                 case SCTP_CMD_REPORT_TSN:
1093                         /* Record the arrival of a TSN.  */
1094                         sctp_tsnmap_mark(&asoc->peer.tsn_map, cmd->obj.u32);
1095                         break;
1096
1097                 case SCTP_CMD_REPORT_FWDTSN:
1098                         /* Move the Cumulattive TSN Ack ahead. */
1099                         sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32);
1100
1101                         /* Abort any in progress partial delivery. */
1102                         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
1103                         break;
1104
1105                 case SCTP_CMD_PROCESS_FWDTSN:
1106                         sctp_cmd_process_fwdtsn(&asoc->ulpq, cmd->obj.ptr);
1107                         break;
1108
1109                 case SCTP_CMD_GEN_SACK:
1110                         /* Generate a Selective ACK.
1111                          * The argument tells us whether to just count
1112                          * the packet and MAYBE generate a SACK, or
1113                          * force a SACK out.
1114                          */
1115                         force = cmd->obj.i32;
1116                         error = sctp_gen_sack(asoc, force, commands);
1117                         break;
1118
1119                 case SCTP_CMD_PROCESS_SACK:
1120                         /* Process an inbound SACK.  */
1121                         error = sctp_cmd_process_sack(commands, asoc,
1122                                                       cmd->obj.ptr);
1123                         break;
1124
1125                 case SCTP_CMD_GEN_INIT_ACK:
1126                         /* Generate an INIT ACK chunk.  */
1127                         new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1128                                                      0);
1129                         if (!new_obj)
1130                                 goto nomem;
1131
1132                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1133                                         SCTP_CHUNK(new_obj));
1134                         break;
1135
1136                 case SCTP_CMD_PEER_INIT:
1137                         /* Process a unified INIT from the peer.
1138                          * Note: Only used during INIT-ACK processing.  If
1139                          * there is an error just return to the outter
1140                          * layer which will bail.
1141                          */
1142                         error = sctp_cmd_process_init(commands, asoc, chunk,
1143                                                       cmd->obj.ptr, gfp);
1144                         break;
1145
1146                 case SCTP_CMD_GEN_COOKIE_ECHO:
1147                         /* Generate a COOKIE ECHO chunk.  */
1148                         new_obj = sctp_make_cookie_echo(asoc, chunk);
1149                         if (!new_obj) {
1150                                 if (cmd->obj.ptr)
1151                                         sctp_chunk_free(cmd->obj.ptr);
1152                                 goto nomem;
1153                         }
1154                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1155                                         SCTP_CHUNK(new_obj));
1156
1157                         /* If there is an ERROR chunk to be sent along with
1158                          * the COOKIE_ECHO, send it, too.
1159                          */
1160                         if (cmd->obj.ptr)
1161                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1162                                                 SCTP_CHUNK(cmd->obj.ptr));
1163
1164                         /* FIXME - Eventually come up with a cleaner way to
1165                          * enabling COOKIE-ECHO + DATA bundling during
1166                          * multihoming stale cookie scenarios, the following
1167                          * command plays with asoc->peer.retran_path to
1168                          * avoid the problem of sending the COOKIE-ECHO and
1169                          * DATA in different paths, which could result
1170                          * in the association being ABORTed if the DATA chunk
1171                          * is processed first by the server.  Checking the
1172                          * init error counter simply causes this command
1173                          * to be executed only during failed attempts of
1174                          * association establishment.
1175                          */
1176                         if ((asoc->peer.retran_path !=
1177                              asoc->peer.primary_path) &&
1178                             (asoc->init_err_counter > 0)) {
1179                                 sctp_add_cmd_sf(commands,
1180                                                 SCTP_CMD_FORCE_PRIM_RETRAN,
1181                                                 SCTP_NULL());
1182                         }
1183
1184                         break;
1185
1186                 case SCTP_CMD_GEN_SHUTDOWN:
1187                         /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1188                          * Reset error counts.
1189                          */
1190                         asoc->overall_error_count = 0;
1191
1192                         /* Generate a SHUTDOWN chunk.  */
1193                         new_obj = sctp_make_shutdown(asoc, chunk);
1194                         if (!new_obj)
1195                                 goto nomem;
1196                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1197                                         SCTP_CHUNK(new_obj));
1198                         break;
1199
1200                 case SCTP_CMD_CHUNK_ULP:
1201                         /* Send a chunk to the sockets layer.  */
1202                         SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1203                                           "chunk_up:", cmd->obj.ptr,
1204                                           "ulpq:", &asoc->ulpq);
1205                         sctp_ulpq_tail_data(&asoc->ulpq, cmd->obj.ptr,
1206                                             GFP_ATOMIC);
1207                         break;
1208
1209                 case SCTP_CMD_EVENT_ULP:
1210                         /* Send a notification to the sockets layer.  */
1211                         SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1212                                           "event_up:",cmd->obj.ptr,
1213                                           "ulpq:",&asoc->ulpq);
1214                         sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ptr);
1215                         break;
1216
1217                 case SCTP_CMD_REPLY:
1218                         /* If an caller has not already corked, do cork. */
1219                         if (!asoc->outqueue.cork) {
1220                                 sctp_outq_cork(&asoc->outqueue);
1221                                 local_cork = 1;
1222                         }
1223                         /* Send a chunk to our peer.  */
1224                         error = sctp_outq_tail(&asoc->outqueue, cmd->obj.ptr);
1225                         break;
1226
1227                 case SCTP_CMD_SEND_PKT:
1228                         /* Send a full packet to our peer.  */
1229                         packet = cmd->obj.ptr;
1230                         sctp_packet_transmit(packet);
1231                         sctp_ootb_pkt_free(packet);
1232                         break;
1233
1234                 case SCTP_CMD_RETRAN:
1235                         /* Mark a transport for retransmission.  */
1236                         sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1237                                         SCTP_RTXR_T3_RTX);
1238                         break;
1239
1240                 case SCTP_CMD_TRANSMIT:
1241                         /* Kick start transmission. */
1242                         error = sctp_outq_uncork(&asoc->outqueue);
1243                         local_cork = 0;
1244                         break;
1245
1246                 case SCTP_CMD_ECN_CE:
1247                         /* Do delayed CE processing.   */
1248                         sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1249                         break;
1250
1251                 case SCTP_CMD_ECN_ECNE:
1252                         /* Do delayed ECNE processing. */
1253                         new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1254                                                         chunk);
1255                         if (new_obj)
1256                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1257                                                 SCTP_CHUNK(new_obj));
1258                         break;
1259
1260                 case SCTP_CMD_ECN_CWR:
1261                         /* Do delayed CWR processing.  */
1262                         sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1263                         break;
1264
1265                 case SCTP_CMD_SETUP_T2:
1266                         sctp_cmd_setup_t2(commands, asoc, cmd->obj.ptr);
1267                         break;
1268
1269                 case SCTP_CMD_TIMER_START:
1270                         timer = &asoc->timers[cmd->obj.to];
1271                         timeout = asoc->timeouts[cmd->obj.to];
1272                         BUG_ON(!timeout);
1273
1274                         timer->expires = jiffies + timeout;
1275                         sctp_association_hold(asoc);
1276                         add_timer(timer);
1277                         break;
1278
1279                 case SCTP_CMD_TIMER_RESTART:
1280                         timer = &asoc->timers[cmd->obj.to];
1281                         timeout = asoc->timeouts[cmd->obj.to];
1282                         if (!mod_timer(timer, jiffies + timeout))
1283                                 sctp_association_hold(asoc);
1284                         break;
1285
1286                 case SCTP_CMD_TIMER_STOP:
1287                         timer = &asoc->timers[cmd->obj.to];
1288                         if (timer_pending(timer) && del_timer(timer))
1289                                 sctp_association_put(asoc);
1290                         break;
1291
1292                 case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1293                         chunk = cmd->obj.ptr;
1294                         t = sctp_assoc_choose_init_transport(asoc);
1295                         asoc->init_last_sent_to = t;
1296                         chunk->transport = t;
1297                         t->init_sent_count++;
1298                         break;
1299
1300                 case SCTP_CMD_INIT_RESTART:
1301                         /* Do the needed accounting and updates
1302                          * associated with restarting an initialization
1303                          * timer. Only multiply the timeout by two if
1304                          * all transports have been tried at the current
1305                          * timeout.
1306                          */
1307                         t = asoc->init_last_sent_to;
1308                         asoc->init_err_counter++;
1309
1310                         if (t->init_sent_count > (asoc->init_cycle + 1)) {
1311                                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] *= 2;
1312                                 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] >
1313                                     asoc->max_init_timeo) {
1314                                         asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
1315                                                 asoc->max_init_timeo;
1316                                 }
1317                                 asoc->init_cycle++;
1318                                 SCTP_DEBUG_PRINTK(
1319                                         "T1 INIT Timeout adjustment"
1320                                         " init_err_counter: %d"
1321                                         " cycle: %d"
1322                                         " timeout: %ld\n",
1323                                         asoc->init_err_counter,
1324                                         asoc->init_cycle,
1325                                         asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT]);
1326                         }
1327
1328                         sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1329                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1330                         break;
1331
1332                 case SCTP_CMD_COOKIEECHO_RESTART:
1333                         /* Do the needed accounting and updates
1334                          * associated with restarting an initialization
1335                          * timer. Only multiply the timeout by two if
1336                          * all transports have been tried at the current
1337                          * timeout.
1338                          */
1339                         asoc->init_err_counter++;
1340
1341                         asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] *= 2;
1342                         if (asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] >
1343                             asoc->max_init_timeo) {
1344                                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
1345                                         asoc->max_init_timeo;
1346                         }
1347                         SCTP_DEBUG_PRINTK(
1348                                 "T1 COOKIE Timeout adjustment"
1349                                 " init_err_counter: %d"
1350                                 " timeout: %ld\n",
1351                                 asoc->init_err_counter,
1352                                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE]);
1353
1354                         /* If we've sent any data bundled with
1355                          * COOKIE-ECHO we need to resend.
1356                          */
1357                         list_for_each(pos, &asoc->peer.transport_addr_list) {
1358                                 t = list_entry(pos, struct sctp_transport,
1359                                                transports);
1360                                 sctp_retransmit_mark(&asoc->outqueue, t, 0);
1361                         }
1362
1363                         sctp_add_cmd_sf(commands,
1364                                         SCTP_CMD_TIMER_RESTART,
1365                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1366                         break;
1367
1368                 case SCTP_CMD_INIT_FAILED:
1369                         sctp_cmd_init_failed(commands, asoc, cmd->obj.err);
1370                         break;
1371
1372                 case SCTP_CMD_ASSOC_FAILED:
1373                         sctp_cmd_assoc_failed(commands, asoc, event_type,
1374                                               subtype, chunk, cmd->obj.err);
1375                         break;
1376
1377                 case SCTP_CMD_INIT_COUNTER_INC:
1378                         asoc->init_err_counter++;
1379                         break;
1380
1381                 case SCTP_CMD_INIT_COUNTER_RESET:
1382                         asoc->init_err_counter = 0;
1383                         asoc->init_cycle = 0;
1384                         break;
1385
1386                 case SCTP_CMD_REPORT_DUP:
1387                         sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1388                                              cmd->obj.u32);
1389                         break;
1390
1391                 case SCTP_CMD_REPORT_BAD_TAG:
1392                         SCTP_DEBUG_PRINTK("vtag mismatch!\n");
1393                         break;
1394
1395                 case SCTP_CMD_STRIKE:
1396                         /* Mark one strike against a transport.  */
1397                         sctp_do_8_2_transport_strike(asoc, cmd->obj.transport);
1398                         break;
1399
1400                 case SCTP_CMD_TRANSPORT_RESET:
1401                         t = cmd->obj.transport;
1402                         sctp_cmd_transport_reset(commands, asoc, t);
1403                         break;
1404
1405                 case SCTP_CMD_TRANSPORT_ON:
1406                         t = cmd->obj.transport;
1407                         sctp_cmd_transport_on(commands, asoc, t, chunk);
1408                         break;
1409
1410                 case SCTP_CMD_HB_TIMERS_START:
1411                         sctp_cmd_hb_timers_start(commands, asoc);
1412                         break;
1413
1414                 case SCTP_CMD_HB_TIMER_UPDATE:
1415                         t = cmd->obj.transport;
1416                         sctp_cmd_hb_timer_update(commands, asoc, t);
1417                         break;
1418
1419                 case SCTP_CMD_HB_TIMERS_STOP:
1420                         sctp_cmd_hb_timers_stop(commands, asoc);
1421                         break;
1422
1423                 case SCTP_CMD_REPORT_ERROR:
1424                         error = cmd->obj.error;
1425                         break;
1426
1427                 case SCTP_CMD_PROCESS_CTSN:
1428                         /* Dummy up a SACK for processing. */
1429                         sackh.cum_tsn_ack = cmd->obj.be32;
1430                         sackh.a_rwnd = 0;
1431                         sackh.num_gap_ack_blocks = 0;
1432                         sackh.num_dup_tsns = 0;
1433                         sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1434                                         SCTP_SACKH(&sackh));
1435                         break;
1436
1437                 case SCTP_CMD_DISCARD_PACKET:
1438                         /* We need to discard the whole packet.  */
1439                         chunk->pdiscard = 1;
1440                         break;
1441
1442                 case SCTP_CMD_RTO_PENDING:
1443                         t = cmd->obj.transport;
1444                         t->rto_pending = 1;
1445                         break;
1446
1447                 case SCTP_CMD_PART_DELIVER:
1448                         sctp_ulpq_partial_delivery(&asoc->ulpq, cmd->obj.ptr,
1449                                                    GFP_ATOMIC);
1450                         break;
1451
1452                 case SCTP_CMD_RENEGE:
1453                         sctp_ulpq_renege(&asoc->ulpq, cmd->obj.ptr,
1454                                          GFP_ATOMIC);
1455                         break;
1456
1457                 case SCTP_CMD_SETUP_T4:
1458                         sctp_cmd_setup_t4(commands, asoc, cmd->obj.ptr);
1459                         break;
1460
1461                 case SCTP_CMD_PROCESS_OPERR:
1462                         sctp_cmd_process_operr(commands, asoc, chunk);
1463                         break;
1464                 case SCTP_CMD_CLEAR_INIT_TAG:
1465                         asoc->peer.i.init_tag = 0;
1466                         break;
1467                 case SCTP_CMD_DEL_NON_PRIMARY:
1468                         sctp_cmd_del_non_primary(asoc);
1469                         break;
1470                 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1471                         sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1472                         break;
1473                 case SCTP_CMD_FORCE_PRIM_RETRAN:
1474                         t = asoc->peer.retran_path;
1475                         asoc->peer.retran_path = asoc->peer.primary_path;
1476                         error = sctp_outq_uncork(&asoc->outqueue);
1477                         local_cork = 0;
1478                         asoc->peer.retran_path = t;
1479                         break;
1480                 case SCTP_CMD_SET_SK_ERR:
1481                         sctp_cmd_set_sk_err(asoc, cmd->obj.error);
1482                         break;
1483                 default:
1484                         printk(KERN_WARNING "Impossible command: %u, %p\n",
1485                                cmd->verb, cmd->obj.ptr);
1486                         break;
1487                 };
1488                 if (error)
1489                         break;
1490         }
1491
1492 out:
1493         if (local_cork)
1494                 sctp_outq_uncork(&asoc->outqueue);
1495         return error;
1496 nomem:
1497         error = -ENOMEM;
1498         goto out;
1499 }
1500