[PATCH] gfp flags annotations - part 1
[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                                 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         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,
501                                  gfp_t gfp)
502 {
503         int error;
504
505         /* We only process the init as a sideeffect in a single
506          * case.   This is when we process the INIT-ACK.   If we
507          * fail during INIT processing (due to malloc problems),
508          * just return the error and stop processing the stack.
509          */
510         if (!sctp_process_init(asoc, chunk->chunk_hdr->type,
511                                sctp_source(chunk), peer_init, gfp))
512                 error = -ENOMEM;
513         else
514                 error = 0;
515
516         return error;
517 }
518
519 /* Helper function to break out starting up of heartbeat timers.  */
520 static void sctp_cmd_hb_timers_start(sctp_cmd_seq_t *cmds,
521                                      struct sctp_association *asoc)
522 {
523         struct sctp_transport *t;
524         struct list_head *pos;
525
526         /* Start a heartbeat timer for each transport on the association.
527          * hold a reference on the transport to make sure none of
528          * the needed data structures go away.
529          */
530         list_for_each(pos, &asoc->peer.transport_addr_list) {
531                 t = list_entry(pos, struct sctp_transport, transports);
532
533                 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
534                         sctp_transport_hold(t);
535         }
536 }
537
538 static void sctp_cmd_hb_timers_stop(sctp_cmd_seq_t *cmds,
539                                     struct sctp_association *asoc)
540 {
541         struct sctp_transport *t;
542         struct list_head *pos;
543
544         /* Stop all heartbeat timers. */
545
546         list_for_each(pos, &asoc->peer.transport_addr_list) {
547                 t = list_entry(pos, struct sctp_transport, transports);
548                 if (del_timer(&t->hb_timer))
549                         sctp_transport_put(t);
550         }
551 }
552
553 /* Helper function to stop any pending T3-RTX timers */
554 static void sctp_cmd_t3_rtx_timers_stop(sctp_cmd_seq_t *cmds,
555                                         struct sctp_association *asoc)
556 {
557         struct sctp_transport *t;
558         struct list_head *pos;
559
560         list_for_each(pos, &asoc->peer.transport_addr_list) {
561                 t = list_entry(pos, struct sctp_transport, transports);
562                 if (timer_pending(&t->T3_rtx_timer) &&
563                     del_timer(&t->T3_rtx_timer)) {
564                         sctp_transport_put(t);
565                 }
566         }
567 }
568
569
570 /* Helper function to update the heartbeat timer. */
571 static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
572                                      struct sctp_association *asoc,
573                                      struct sctp_transport *t)
574 {
575         /* Update the heartbeat timer.  */
576         if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
577                 sctp_transport_hold(t);
578 }
579
580 /* Helper function to handle the reception of an HEARTBEAT ACK.  */
581 static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds,
582                                   struct sctp_association *asoc,
583                                   struct sctp_transport *t,
584                                   struct sctp_chunk *chunk)
585 {
586         sctp_sender_hb_info_t *hbinfo;
587
588         /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
589          * HEARTBEAT should clear the error counter of the destination
590          * transport address to which the HEARTBEAT was sent.
591          * The association's overall error count is also cleared.
592          */
593         t->error_count = 0;
594         t->asoc->overall_error_count = 0;
595
596         /* Mark the destination transport address as active if it is not so
597          * marked.
598          */
599         if (t->state == SCTP_INACTIVE)
600                 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
601                                              SCTP_HEARTBEAT_SUCCESS);
602
603         /* The receiver of the HEARTBEAT ACK should also perform an
604          * RTT measurement for that destination transport address
605          * using the time value carried in the HEARTBEAT ACK chunk.
606          */
607         hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
608         sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
609 }
610
611 /* Helper function to do a transport reset at the expiry of the hearbeat
612  * timer.
613  */
614 static void sctp_cmd_transport_reset(sctp_cmd_seq_t *cmds,
615                                      struct sctp_association *asoc,
616                                      struct sctp_transport *t)
617 {
618         sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
619
620         /* Mark one strike against a transport.  */
621         sctp_do_8_2_transport_strike(asoc, t);
622 }
623
624 /* Helper function to process the process SACK command.  */
625 static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds,
626                                  struct sctp_association *asoc,
627                                  struct sctp_sackhdr *sackh)
628 {
629         int err;
630
631         if (sctp_outq_sack(&asoc->outqueue, sackh)) {
632                 /* There are no more TSNs awaiting SACK.  */
633                 err = sctp_do_sm(SCTP_EVENT_T_OTHER,
634                                  SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
635                                  asoc->state, asoc->ep, asoc, NULL,
636                                  GFP_ATOMIC);
637         } else {
638                 /* Windows may have opened, so we need
639                  * to check if we have DATA to transmit
640                  */
641                 err = sctp_outq_flush(&asoc->outqueue, 0);
642         }
643
644         return err;
645 }
646
647 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
648  * the transport for a shutdown chunk.
649  */
650 static void sctp_cmd_setup_t2(sctp_cmd_seq_t *cmds, 
651                               struct sctp_association *asoc,
652                               struct sctp_chunk *chunk)
653 {
654         struct sctp_transport *t;
655
656         t = sctp_assoc_choose_shutdown_transport(asoc);
657         asoc->shutdown_last_sent_to = t;
658         asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
659         chunk->transport = t;
660 }
661
662 /* Helper function to change the state of an association. */
663 static void sctp_cmd_new_state(sctp_cmd_seq_t *cmds, 
664                                struct sctp_association *asoc,
665                                sctp_state_t state)
666 {
667         struct sock *sk = asoc->base.sk;
668
669         asoc->state = state;
670
671         SCTP_DEBUG_PRINTK("sctp_cmd_new_state: asoc %p[%s]\n",
672                           asoc, sctp_state_tbl[state]);
673
674         if (sctp_style(sk, TCP)) {
675                 /* Change the sk->sk_state of a TCP-style socket that has
676                  * sucessfully completed a connect() call.
677                  */
678                 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
679                         sk->sk_state = SCTP_SS_ESTABLISHED;
680
681                 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
682                 if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
683                     sctp_sstate(sk, ESTABLISHED))
684                         sk->sk_shutdown |= RCV_SHUTDOWN;
685         }
686
687         if (sctp_state(asoc, COOKIE_WAIT)) {
688                 /* Reset init timeouts since they may have been
689                  * increased due to timer expirations.
690                  */
691                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
692                         asoc->ep->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT];
693                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
694                         asoc->ep->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE];
695         }
696
697         if (sctp_state(asoc, ESTABLISHED) ||
698             sctp_state(asoc, CLOSED) ||
699             sctp_state(asoc, SHUTDOWN_RECEIVED)) {
700                 /* Wake up any processes waiting in the asoc's wait queue in
701                  * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
702                  */
703                 if (waitqueue_active(&asoc->wait))
704                         wake_up_interruptible(&asoc->wait);
705
706                 /* Wake up any processes waiting in the sk's sleep queue of
707                  * a TCP-style or UDP-style peeled-off socket in
708                  * sctp_wait_for_accept() or sctp_wait_for_packet().
709                  * For a UDP-style socket, the waiters are woken up by the
710                  * notifications.
711                  */
712                 if (!sctp_style(sk, UDP))
713                         sk->sk_state_change(sk);
714         }
715 }
716
717 /* Helper function to delete an association. */
718 static void sctp_cmd_delete_tcb(sctp_cmd_seq_t *cmds,
719                                 struct sctp_association *asoc)
720 {
721         struct sock *sk = asoc->base.sk;
722
723         /* If it is a non-temporary association belonging to a TCP-style
724          * listening socket that is not closed, do not free it so that accept() 
725          * can pick it up later.
726          */ 
727         if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
728             (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
729                 return;
730
731         sctp_unhash_established(asoc);
732         sctp_association_free(asoc);
733 }
734
735 /*
736  * ADDIP Section 4.1 ASCONF Chunk Procedures
737  * A4) Start a T-4 RTO timer, using the RTO value of the selected
738  * destination address (we use active path instead of primary path just
739  * because primary path may be inactive. 
740  */
741 static void sctp_cmd_setup_t4(sctp_cmd_seq_t *cmds,
742                                 struct sctp_association *asoc,
743                                 struct sctp_chunk *chunk)
744 {
745         struct sctp_transport *t;
746
747         t = asoc->peer.active_path;
748         asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
749         chunk->transport = t;
750 }
751
752 /* Process an incoming Operation Error Chunk. */ 
753 static void sctp_cmd_process_operr(sctp_cmd_seq_t *cmds,
754                                    struct sctp_association *asoc,
755                                    struct sctp_chunk *chunk)
756 {
757         struct sctp_operr_chunk *operr_chunk;
758         struct sctp_errhdr *err_hdr;
759
760         operr_chunk = (struct sctp_operr_chunk *)chunk->chunk_hdr;
761         err_hdr = &operr_chunk->err_hdr;
762
763         switch (err_hdr->cause) {
764         case SCTP_ERROR_UNKNOWN_CHUNK:
765         {
766                 struct sctp_chunkhdr *unk_chunk_hdr;
767
768                 unk_chunk_hdr = (struct sctp_chunkhdr *)err_hdr->variable;
769                 switch (unk_chunk_hdr->type) {
770                 /* ADDIP 4.1 A9) If the peer responds to an ASCONF with an
771                  * ERROR chunk reporting that it did not recognized the ASCONF
772                  * chunk type, the sender of the ASCONF MUST NOT send any
773                  * further ASCONF chunks and MUST stop its T-4 timer.
774                  */
775                 case SCTP_CID_ASCONF:
776                         asoc->peer.asconf_capable = 0;
777                         sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
778                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
779                         break;
780                 default:
781                         break;
782                 }
783                 break;
784         }
785         default:
786                 break;
787         }
788 }
789
790 /* Process variable FWDTSN chunk information. */
791 static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq, 
792                                     struct sctp_chunk *chunk)
793 {
794         struct sctp_fwdtsn_skip *skip;
795         /* Walk through all the skipped SSNs */
796         sctp_walk_fwdtsn(skip, chunk) {
797                 sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
798         }
799
800         return;
801 }
802
803 /* Helper function to remove the association non-primary peer 
804  * transports.
805  */ 
806 static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
807 {
808         struct sctp_transport *t;
809         struct list_head *pos;
810         struct list_head *temp;
811
812         list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
813                 t = list_entry(pos, struct sctp_transport, transports);
814                 if (!sctp_cmp_addr_exact(&t->ipaddr,
815                                          &asoc->peer.primary_addr)) {
816                         sctp_assoc_del_peer(asoc, &t->ipaddr);
817                 }
818         }
819
820         return;
821 }
822
823 /* These three macros allow us to pull the debugging code out of the
824  * main flow of sctp_do_sm() to keep attention focused on the real
825  * functionality there.
826  */
827 #define DEBUG_PRE \
828         SCTP_DEBUG_PRINTK("sctp_do_sm prefn: " \
829                           "ep %p, %s, %s, asoc %p[%s], %s\n", \
830                           ep, sctp_evttype_tbl[event_type], \
831                           (*debug_fn)(subtype), asoc, \
832                           sctp_state_tbl[state], state_fn->name)
833
834 #define DEBUG_POST \
835         SCTP_DEBUG_PRINTK("sctp_do_sm postfn: " \
836                           "asoc %p, status: %s\n", \
837                           asoc, sctp_status_tbl[status])
838
839 #define DEBUG_POST_SFX \
840         SCTP_DEBUG_PRINTK("sctp_do_sm post sfx: error %d, asoc %p[%s]\n", \
841                           error, asoc, \
842                           sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
843                           sctp_assoc2id(asoc)))?asoc->state:SCTP_STATE_CLOSED])
844
845 /*
846  * This is the master state machine processing function.
847  *
848  * If you want to understand all of lksctp, this is a
849  * good place to start.
850  */
851 int sctp_do_sm(sctp_event_t event_type, sctp_subtype_t subtype,
852                sctp_state_t state,
853                struct sctp_endpoint *ep,
854                struct sctp_association *asoc,
855                void *event_arg,
856                gfp_t gfp)
857 {
858         sctp_cmd_seq_t commands;
859         const sctp_sm_table_entry_t *state_fn;
860         sctp_disposition_t status;
861         int error = 0;
862         typedef const char *(printfn_t)(sctp_subtype_t);
863
864         static printfn_t *table[] = {
865                 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
866         };
867         printfn_t *debug_fn  __attribute__ ((unused)) = table[event_type];
868
869         /* Look up the state function, run it, and then process the
870          * side effects.  These three steps are the heart of lksctp.
871          */
872         state_fn = sctp_sm_lookup_event(event_type, state, subtype);
873
874         sctp_init_cmd_seq(&commands);
875
876         DEBUG_PRE;
877         status = (*state_fn->fn)(ep, asoc, subtype, event_arg, &commands);
878         DEBUG_POST;
879
880         error = sctp_side_effects(event_type, subtype, state,
881                                   ep, asoc, event_arg, status, 
882                                   &commands, gfp);
883         DEBUG_POST_SFX;
884
885         return error;
886 }
887
888 #undef DEBUG_PRE
889 #undef DEBUG_POST
890
891 /*****************************************************************
892  * This the master state function side effect processing function.
893  *****************************************************************/
894 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
895                              sctp_state_t state,
896                              struct sctp_endpoint *ep,
897                              struct sctp_association *asoc,
898                              void *event_arg,
899                              sctp_disposition_t status,
900                              sctp_cmd_seq_t *commands,
901                              gfp_t gfp)
902 {
903         int error;
904
905         /* FIXME - Most of the dispositions left today would be categorized
906          * as "exceptional" dispositions.  For those dispositions, it
907          * may not be proper to run through any of the commands at all.
908          * For example, the command interpreter might be run only with
909          * disposition SCTP_DISPOSITION_CONSUME.
910          */
911         if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
912                                                ep, asoc,
913                                                event_arg, status,
914                                                commands, gfp)))
915                 goto bail;
916
917         switch (status) {
918         case SCTP_DISPOSITION_DISCARD:
919                 SCTP_DEBUG_PRINTK("Ignored sctp protocol event - state %d, "
920                                   "event_type %d, event_id %d\n",
921                                   state, event_type, subtype.chunk);
922                 break;
923
924         case SCTP_DISPOSITION_NOMEM:
925                 /* We ran out of memory, so we need to discard this
926                  * packet.
927                  */
928                 /* BUG--we should now recover some memory, probably by
929                  * reneging...
930                  */
931                 error = -ENOMEM;
932                 break;
933
934         case SCTP_DISPOSITION_DELETE_TCB:
935                 /* This should now be a command. */
936                 break;
937
938         case SCTP_DISPOSITION_CONSUME:
939         case SCTP_DISPOSITION_ABORT:
940                 /*
941                  * We should no longer have much work to do here as the
942                  * real work has been done as explicit commands above.
943                  */
944                 break;
945
946         case SCTP_DISPOSITION_VIOLATION:
947                 printk(KERN_ERR "sctp protocol violation state %d "
948                        "chunkid %d\n", state, subtype.chunk);
949                 break;
950
951         case SCTP_DISPOSITION_NOT_IMPL:
952                 printk(KERN_WARNING "sctp unimplemented feature in state %d, "
953                        "event_type %d, event_id %d\n",
954                        state, event_type, subtype.chunk);
955                 break;
956
957         case SCTP_DISPOSITION_BUG:
958                 printk(KERN_ERR "sctp bug in state %d, "
959                        "event_type %d, event_id %d\n",
960                        state, event_type, subtype.chunk);
961                 BUG();
962                 break;
963
964         default:
965                 printk(KERN_ERR "sctp impossible disposition %d "
966                        "in state %d, event_type %d, event_id %d\n",
967                        status, state, event_type, subtype.chunk);
968                 BUG();
969                 break;
970         };
971
972 bail:
973         return error;
974 }
975
976 /********************************************************************
977  * 2nd Level Abstractions
978  ********************************************************************/
979
980 /* This is the side-effect interpreter.  */
981 static int sctp_cmd_interpreter(sctp_event_t event_type,
982                                 sctp_subtype_t subtype,
983                                 sctp_state_t state,
984                                 struct sctp_endpoint *ep,
985                                 struct sctp_association *asoc,
986                                 void *event_arg,
987                                 sctp_disposition_t status,
988                                 sctp_cmd_seq_t *commands,
989                                 gfp_t gfp)
990 {
991         int error = 0;
992         int force;
993         sctp_cmd_t *cmd;
994         struct sctp_chunk *new_obj;
995         struct sctp_chunk *chunk = NULL;
996         struct sctp_packet *packet;
997         struct list_head *pos;
998         struct timer_list *timer;
999         unsigned long timeout;
1000         struct sctp_transport *t;
1001         struct sctp_sackhdr sackh;
1002         int local_cork = 0;
1003
1004         if (SCTP_EVENT_T_TIMEOUT != event_type)
1005                 chunk = (struct sctp_chunk *) event_arg;
1006
1007         /* Note:  This whole file is a huge candidate for rework.
1008          * For example, each command could either have its own handler, so
1009          * the loop would look like:
1010          *     while (cmds)
1011          *         cmd->handle(x, y, z)
1012          * --jgrimm
1013          */
1014         while (NULL != (cmd = sctp_next_cmd(commands))) {
1015                 switch (cmd->verb) {
1016                 case SCTP_CMD_NOP:
1017                         /* Do nothing. */
1018                         break;
1019
1020                 case SCTP_CMD_NEW_ASOC:
1021                         /* Register a new association.  */
1022                         if (local_cork) {
1023                                 sctp_outq_uncork(&asoc->outqueue); 
1024                                 local_cork = 0;
1025                         }
1026                         asoc = cmd->obj.ptr;
1027                         /* Register with the endpoint.  */
1028                         sctp_endpoint_add_asoc(ep, asoc);
1029                         sctp_hash_established(asoc);
1030                         break;
1031
1032                 case SCTP_CMD_UPDATE_ASSOC:
1033                        sctp_assoc_update(asoc, cmd->obj.ptr);
1034                        break;
1035
1036                 case SCTP_CMD_PURGE_OUTQUEUE:
1037                        sctp_outq_teardown(&asoc->outqueue);
1038                        break;
1039
1040                 case SCTP_CMD_DELETE_TCB:                       
1041                         if (local_cork) {
1042                                 sctp_outq_uncork(&asoc->outqueue);
1043                                 local_cork = 0;
1044                         }
1045                         /* Delete the current association.  */
1046                         sctp_cmd_delete_tcb(commands, asoc);
1047                         asoc = NULL;
1048                         break;
1049
1050                 case SCTP_CMD_NEW_STATE:
1051                         /* Enter a new state.  */
1052                         sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1053                         break;
1054
1055                 case SCTP_CMD_REPORT_TSN:
1056                         /* Record the arrival of a TSN.  */
1057                         sctp_tsnmap_mark(&asoc->peer.tsn_map, cmd->obj.u32);
1058                         break;
1059
1060                 case SCTP_CMD_REPORT_FWDTSN:
1061                         /* Move the Cumulattive TSN Ack ahead. */
1062                         sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32);
1063
1064                         /* Abort any in progress partial delivery. */
1065                         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
1066                         break;
1067
1068                 case SCTP_CMD_PROCESS_FWDTSN:
1069                         sctp_cmd_process_fwdtsn(&asoc->ulpq, cmd->obj.ptr);
1070                         break;
1071
1072                 case SCTP_CMD_GEN_SACK:
1073                         /* Generate a Selective ACK.
1074                          * The argument tells us whether to just count
1075                          * the packet and MAYBE generate a SACK, or
1076                          * force a SACK out.
1077                          */
1078                         force = cmd->obj.i32;
1079                         error = sctp_gen_sack(asoc, force, commands);
1080                         break;
1081
1082                 case SCTP_CMD_PROCESS_SACK:
1083                         /* Process an inbound SACK.  */
1084                         error = sctp_cmd_process_sack(commands, asoc,
1085                                                       cmd->obj.ptr);
1086                         break;
1087
1088                 case SCTP_CMD_GEN_INIT_ACK:
1089                         /* Generate an INIT ACK chunk.  */
1090                         new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1091                                                      0);
1092                         if (!new_obj)
1093                                 goto nomem;
1094
1095                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1096                                         SCTP_CHUNK(new_obj));
1097                         break;
1098
1099                 case SCTP_CMD_PEER_INIT:
1100                         /* Process a unified INIT from the peer.
1101                          * Note: Only used during INIT-ACK processing.  If
1102                          * there is an error just return to the outter
1103                          * layer which will bail.
1104                          */
1105                         error = sctp_cmd_process_init(commands, asoc, chunk,
1106                                                       cmd->obj.ptr, gfp);
1107                         break;
1108
1109                 case SCTP_CMD_GEN_COOKIE_ECHO:
1110                         /* Generate a COOKIE ECHO chunk.  */
1111                         new_obj = sctp_make_cookie_echo(asoc, chunk);
1112                         if (!new_obj) {
1113                                 if (cmd->obj.ptr)
1114                                         sctp_chunk_free(cmd->obj.ptr);
1115                                 goto nomem;
1116                         }
1117                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1118                                         SCTP_CHUNK(new_obj));
1119
1120                         /* If there is an ERROR chunk to be sent along with
1121                          * the COOKIE_ECHO, send it, too.
1122                          */
1123                         if (cmd->obj.ptr)
1124                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1125                                                 SCTP_CHUNK(cmd->obj.ptr));
1126
1127                         /* FIXME - Eventually come up with a cleaner way to
1128                          * enabling COOKIE-ECHO + DATA bundling during 
1129                          * multihoming stale cookie scenarios, the following 
1130                          * command plays with asoc->peer.retran_path to 
1131                          * avoid the problem of sending the COOKIE-ECHO and 
1132                          * DATA in different paths, which could result 
1133                          * in the association being ABORTed if the DATA chunk 
1134                          * is processed first by the server.  Checking the
1135                          * init error counter simply causes this command
1136                          * to be executed only during failed attempts of
1137                          * association establishment.
1138                          */
1139                         if ((asoc->peer.retran_path !=
1140                              asoc->peer.primary_path) &&
1141                             (asoc->init_err_counter > 0)) {
1142                                 sctp_add_cmd_sf(commands,
1143                                                 SCTP_CMD_FORCE_PRIM_RETRAN,
1144                                                 SCTP_NULL());
1145                         }
1146
1147                         break;
1148
1149                 case SCTP_CMD_GEN_SHUTDOWN:
1150                         /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1151                          * Reset error counts.
1152                          */
1153                         asoc->overall_error_count = 0;
1154
1155                         /* Generate a SHUTDOWN chunk.  */
1156                         new_obj = sctp_make_shutdown(asoc, chunk);
1157                         if (!new_obj)
1158                                 goto nomem;
1159                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1160                                         SCTP_CHUNK(new_obj));
1161                         break;
1162
1163                 case SCTP_CMD_CHUNK_ULP:
1164                         /* Send a chunk to the sockets layer.  */
1165                         SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1166                                           "chunk_up:", cmd->obj.ptr,
1167                                           "ulpq:", &asoc->ulpq);
1168                         sctp_ulpq_tail_data(&asoc->ulpq, cmd->obj.ptr,
1169                                             GFP_ATOMIC);
1170                         break;
1171
1172                 case SCTP_CMD_EVENT_ULP:
1173                         /* Send a notification to the sockets layer.  */
1174                         SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1175                                           "event_up:",cmd->obj.ptr,
1176                                           "ulpq:",&asoc->ulpq);
1177                         sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ptr);
1178                         break;
1179
1180                 case SCTP_CMD_REPLY:
1181                         /* If an caller has not already corked, do cork. */
1182                         if (!asoc->outqueue.cork) {
1183                                 sctp_outq_cork(&asoc->outqueue);
1184                                 local_cork = 1;
1185                         }
1186                         /* Send a chunk to our peer.  */
1187                         error = sctp_outq_tail(&asoc->outqueue, cmd->obj.ptr);
1188                         break;
1189
1190                 case SCTP_CMD_SEND_PKT:
1191                         /* Send a full packet to our peer.  */
1192                         packet = cmd->obj.ptr;
1193                         sctp_packet_transmit(packet);
1194                         sctp_ootb_pkt_free(packet);
1195                         break;
1196
1197                 case SCTP_CMD_RETRAN:
1198                         /* Mark a transport for retransmission.  */
1199                         sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1200                                         SCTP_RTXR_T3_RTX);
1201                         break;
1202
1203                 case SCTP_CMD_TRANSMIT:
1204                         /* Kick start transmission. */
1205                         error = sctp_outq_uncork(&asoc->outqueue);
1206                         local_cork = 0;
1207                         break;
1208
1209                 case SCTP_CMD_ECN_CE:
1210                         /* Do delayed CE processing.   */
1211                         sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1212                         break;
1213
1214                 case SCTP_CMD_ECN_ECNE:
1215                         /* Do delayed ECNE processing. */
1216                         new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1217                                                         chunk);
1218                         if (new_obj)
1219                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1220                                                 SCTP_CHUNK(new_obj));
1221                         break;
1222
1223                 case SCTP_CMD_ECN_CWR:
1224                         /* Do delayed CWR processing.  */
1225                         sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1226                         break;
1227
1228                 case SCTP_CMD_SETUP_T2:
1229                         sctp_cmd_setup_t2(commands, asoc, cmd->obj.ptr);
1230                         break;
1231
1232                 case SCTP_CMD_TIMER_START:
1233                         timer = &asoc->timers[cmd->obj.to];
1234                         timeout = asoc->timeouts[cmd->obj.to];
1235                         if (!timeout)
1236                                 BUG();
1237
1238                         timer->expires = jiffies + timeout;
1239                         sctp_association_hold(asoc);
1240                         add_timer(timer);
1241                         break;
1242
1243                 case SCTP_CMD_TIMER_RESTART:
1244                         timer = &asoc->timers[cmd->obj.to];
1245                         timeout = asoc->timeouts[cmd->obj.to];
1246                         if (!mod_timer(timer, jiffies + timeout))
1247                                 sctp_association_hold(asoc);
1248                         break;
1249
1250                 case SCTP_CMD_TIMER_STOP:
1251                         timer = &asoc->timers[cmd->obj.to];
1252                         if (timer_pending(timer) && del_timer(timer))
1253                                 sctp_association_put(asoc);
1254                         break;
1255
1256                 case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1257                         chunk = cmd->obj.ptr;
1258                         t = sctp_assoc_choose_init_transport(asoc);
1259                         asoc->init_last_sent_to = t;
1260                         chunk->transport = t;
1261                         t->init_sent_count++;
1262                         break;
1263
1264                 case SCTP_CMD_INIT_RESTART:
1265                         /* Do the needed accounting and updates
1266                          * associated with restarting an initialization
1267                          * timer. Only multiply the timeout by two if
1268                          * all transports have been tried at the current
1269                          * timeout.
1270                          */
1271                         t = asoc->init_last_sent_to;
1272                         asoc->init_err_counter++;
1273
1274                         if (t->init_sent_count > (asoc->init_cycle + 1)) {
1275                                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] *= 2;
1276                                 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] >
1277                                     asoc->max_init_timeo) {
1278                                         asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
1279                                                 asoc->max_init_timeo;
1280                                 }
1281                                 asoc->init_cycle++;
1282                                 SCTP_DEBUG_PRINTK(
1283                                         "T1 INIT Timeout adjustment"
1284                                         " init_err_counter: %d"
1285                                         " cycle: %d"
1286                                         " timeout: %d\n",
1287                                         asoc->init_err_counter,
1288                                         asoc->init_cycle,
1289                                         asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT]);
1290                         }
1291
1292                         sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1293                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1294                         break;
1295
1296                 case SCTP_CMD_COOKIEECHO_RESTART:
1297                         /* Do the needed accounting and updates
1298                          * associated with restarting an initialization
1299                          * timer. Only multiply the timeout by two if
1300                          * all transports have been tried at the current
1301                          * timeout.
1302                          */
1303                         asoc->init_err_counter++;
1304
1305                         asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] *= 2;
1306                         if (asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] >
1307                             asoc->max_init_timeo) {
1308                                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
1309                                         asoc->max_init_timeo;
1310                         }
1311                         SCTP_DEBUG_PRINTK(
1312                                 "T1 COOKIE Timeout adjustment"
1313                                 " init_err_counter: %d"
1314                                 " timeout: %d\n",
1315                                 asoc->init_err_counter,
1316                                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE]);
1317
1318                         /* If we've sent any data bundled with
1319                          * COOKIE-ECHO we need to resend.
1320                          */
1321                         list_for_each(pos, &asoc->peer.transport_addr_list) {
1322                                 t = list_entry(pos, struct sctp_transport,
1323                                                transports);
1324                                 sctp_retransmit_mark(&asoc->outqueue, t, 0);
1325                         }
1326
1327                         sctp_add_cmd_sf(commands,
1328                                         SCTP_CMD_TIMER_RESTART,
1329                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1330                         break;
1331
1332                 case SCTP_CMD_INIT_FAILED:
1333                         sctp_cmd_init_failed(commands, asoc, cmd->obj.u32);
1334                         break;
1335
1336                 case SCTP_CMD_ASSOC_FAILED:
1337                         sctp_cmd_assoc_failed(commands, asoc, event_type,
1338                                               subtype, chunk, cmd->obj.u32);
1339                         break;
1340
1341                 case SCTP_CMD_INIT_COUNTER_INC:
1342                         asoc->init_err_counter++;
1343                         break;
1344
1345                 case SCTP_CMD_INIT_COUNTER_RESET:
1346                         asoc->init_err_counter = 0;
1347                         asoc->init_cycle = 0;
1348                         break;
1349
1350                 case SCTP_CMD_REPORT_DUP:
1351                         sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1352                                              cmd->obj.u32);
1353                         break;
1354
1355                 case SCTP_CMD_REPORT_BAD_TAG:
1356                         SCTP_DEBUG_PRINTK("vtag mismatch!\n");
1357                         break;
1358
1359                 case SCTP_CMD_STRIKE:
1360                         /* Mark one strike against a transport.  */
1361                         sctp_do_8_2_transport_strike(asoc, cmd->obj.transport);
1362                         break;
1363
1364                 case SCTP_CMD_TRANSPORT_RESET:
1365                         t = cmd->obj.transport;
1366                         sctp_cmd_transport_reset(commands, asoc, t);
1367                         break;
1368
1369                 case SCTP_CMD_TRANSPORT_ON:
1370                         t = cmd->obj.transport;
1371                         sctp_cmd_transport_on(commands, asoc, t, chunk);
1372                         break;
1373
1374                 case SCTP_CMD_HB_TIMERS_START:
1375                         sctp_cmd_hb_timers_start(commands, asoc);
1376                         break;
1377
1378                 case SCTP_CMD_HB_TIMER_UPDATE:
1379                         t = cmd->obj.transport;
1380                         sctp_cmd_hb_timer_update(commands, asoc, t);
1381                         break;
1382
1383                 case SCTP_CMD_HB_TIMERS_STOP:
1384                         sctp_cmd_hb_timers_stop(commands, asoc);
1385                         break;
1386
1387                 case SCTP_CMD_REPORT_ERROR:
1388                         error = cmd->obj.error;
1389                         break;
1390
1391                 case SCTP_CMD_PROCESS_CTSN:
1392                         /* Dummy up a SACK for processing. */
1393                         sackh.cum_tsn_ack = cmd->obj.u32;
1394                         sackh.a_rwnd = 0;
1395                         sackh.num_gap_ack_blocks = 0;
1396                         sackh.num_dup_tsns = 0;
1397                         sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1398                                         SCTP_SACKH(&sackh));
1399                         break;
1400
1401                 case SCTP_CMD_DISCARD_PACKET:
1402                         /* We need to discard the whole packet.  */
1403                         chunk->pdiscard = 1;
1404                         break;
1405
1406                 case SCTP_CMD_RTO_PENDING:
1407                         t = cmd->obj.transport;
1408                         t->rto_pending = 1;
1409                         break;
1410
1411                 case SCTP_CMD_PART_DELIVER:
1412                         sctp_ulpq_partial_delivery(&asoc->ulpq, cmd->obj.ptr,
1413                                                    GFP_ATOMIC);
1414                         break;
1415
1416                 case SCTP_CMD_RENEGE:
1417                         sctp_ulpq_renege(&asoc->ulpq, cmd->obj.ptr,
1418                                          GFP_ATOMIC);
1419                         break;
1420
1421                 case SCTP_CMD_SETUP_T4:
1422                         sctp_cmd_setup_t4(commands, asoc, cmd->obj.ptr);
1423                         break;
1424
1425                 case SCTP_CMD_PROCESS_OPERR:
1426                         sctp_cmd_process_operr(commands, asoc, chunk);
1427                         break;
1428                 case SCTP_CMD_CLEAR_INIT_TAG:
1429                         asoc->peer.i.init_tag = 0;
1430                         break;
1431                 case SCTP_CMD_DEL_NON_PRIMARY:
1432                         sctp_cmd_del_non_primary(asoc);
1433                         break;
1434                 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1435                         sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1436                         break;
1437                 case SCTP_CMD_FORCE_PRIM_RETRAN:
1438                         t = asoc->peer.retran_path;
1439                         asoc->peer.retran_path = asoc->peer.primary_path;
1440                         error = sctp_outq_uncork(&asoc->outqueue);
1441                         local_cork = 0;
1442                         asoc->peer.retran_path = t;
1443                         break;
1444                 default:
1445                         printk(KERN_WARNING "Impossible command: %u, %p\n",
1446                                cmd->verb, cmd->obj.ptr);
1447                         break;
1448                 };
1449                 if (error)
1450                         break;
1451         }
1452
1453 out:
1454         if (local_cork)
1455                 sctp_outq_uncork(&asoc->outqueue);
1456         return error;
1457 nomem:
1458         error = -ENOMEM;
1459         goto out;
1460 }
1461