Merge git://git.kernel.org/pub/scm/linux/kernel/git/sam/x86
[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->last_rto = transport->rto;
457         transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
458 }
459
460 /* Worker routine to handle INIT command failure.  */
461 static void sctp_cmd_init_failed(sctp_cmd_seq_t *commands,
462                                  struct sctp_association *asoc,
463                                  unsigned error)
464 {
465         struct sctp_ulpevent *event;
466
467         event = sctp_ulpevent_make_assoc_change(asoc,0, SCTP_CANT_STR_ASSOC,
468                                                 (__u16)error, 0, 0, NULL,
469                                                 GFP_ATOMIC);
470
471         if (event)
472                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
473                                 SCTP_ULPEVENT(event));
474
475         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
476                         SCTP_STATE(SCTP_STATE_CLOSED));
477
478         /* SEND_FAILED sent later when cleaning up the association. */
479         asoc->outqueue.error = error;
480         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
481 }
482
483 /* Worker routine to handle SCTP_CMD_ASSOC_FAILED.  */
484 static void sctp_cmd_assoc_failed(sctp_cmd_seq_t *commands,
485                                   struct sctp_association *asoc,
486                                   sctp_event_t event_type,
487                                   sctp_subtype_t subtype,
488                                   struct sctp_chunk *chunk,
489                                   unsigned error)
490 {
491         struct sctp_ulpevent *event;
492
493         /* Cancel any partial delivery in progress. */
494         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
495
496         if (event_type == SCTP_EVENT_T_CHUNK && subtype.chunk == SCTP_CID_ABORT)
497                 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
498                                                 (__u16)error, 0, 0, chunk,
499                                                 GFP_ATOMIC);
500         else
501                 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
502                                                 (__u16)error, 0, 0, NULL,
503                                                 GFP_ATOMIC);
504         if (event)
505                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
506                                 SCTP_ULPEVENT(event));
507
508         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
509                         SCTP_STATE(SCTP_STATE_CLOSED));
510
511         /* SEND_FAILED sent later when cleaning up the association. */
512         asoc->outqueue.error = error;
513         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
514 }
515
516 /* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
517  * inside the cookie.  In reality, this is only used for INIT-ACK processing
518  * since all other cases use "temporary" associations and can do all
519  * their work in statefuns directly.
520  */
521 static int sctp_cmd_process_init(sctp_cmd_seq_t *commands,
522                                  struct sctp_association *asoc,
523                                  struct sctp_chunk *chunk,
524                                  sctp_init_chunk_t *peer_init,
525                                  gfp_t gfp)
526 {
527         int error;
528
529         /* We only process the init as a sideeffect in a single
530          * case.   This is when we process the INIT-ACK.   If we
531          * fail during INIT processing (due to malloc problems),
532          * just return the error and stop processing the stack.
533          */
534         if (!sctp_process_init(asoc, chunk->chunk_hdr->type,
535                                sctp_source(chunk), peer_init, gfp))
536                 error = -ENOMEM;
537         else
538                 error = 0;
539
540         return error;
541 }
542
543 /* Helper function to break out starting up of heartbeat timers.  */
544 static void sctp_cmd_hb_timers_start(sctp_cmd_seq_t *cmds,
545                                      struct sctp_association *asoc)
546 {
547         struct sctp_transport *t;
548         struct list_head *pos;
549
550         /* Start a heartbeat timer for each transport on the association.
551          * hold a reference on the transport to make sure none of
552          * the needed data structures go away.
553          */
554         list_for_each(pos, &asoc->peer.transport_addr_list) {
555                 t = list_entry(pos, struct sctp_transport, transports);
556
557                 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
558                         sctp_transport_hold(t);
559         }
560 }
561
562 static void sctp_cmd_hb_timers_stop(sctp_cmd_seq_t *cmds,
563                                     struct sctp_association *asoc)
564 {
565         struct sctp_transport *t;
566         struct list_head *pos;
567
568         /* Stop all heartbeat timers. */
569
570         list_for_each(pos, &asoc->peer.transport_addr_list) {
571                 t = list_entry(pos, struct sctp_transport, transports);
572                 if (del_timer(&t->hb_timer))
573                         sctp_transport_put(t);
574         }
575 }
576
577 /* Helper function to stop any pending T3-RTX timers */
578 static void sctp_cmd_t3_rtx_timers_stop(sctp_cmd_seq_t *cmds,
579                                         struct sctp_association *asoc)
580 {
581         struct sctp_transport *t;
582         struct list_head *pos;
583
584         list_for_each(pos, &asoc->peer.transport_addr_list) {
585                 t = list_entry(pos, struct sctp_transport, transports);
586                 if (timer_pending(&t->T3_rtx_timer) &&
587                     del_timer(&t->T3_rtx_timer)) {
588                         sctp_transport_put(t);
589                 }
590         }
591 }
592
593
594 /* Helper function to update the heartbeat timer. */
595 static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
596                                      struct sctp_association *asoc,
597                                      struct sctp_transport *t)
598 {
599         /* Update the heartbeat timer.  */
600         if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
601                 sctp_transport_hold(t);
602 }
603
604 /* Helper function to handle the reception of an HEARTBEAT ACK.  */
605 static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds,
606                                   struct sctp_association *asoc,
607                                   struct sctp_transport *t,
608                                   struct sctp_chunk *chunk)
609 {
610         sctp_sender_hb_info_t *hbinfo;
611
612         /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
613          * HEARTBEAT should clear the error counter of the destination
614          * transport address to which the HEARTBEAT was sent.
615          * The association's overall error count is also cleared.
616          */
617         t->error_count = 0;
618         t->asoc->overall_error_count = 0;
619
620         /* Mark the destination transport address as active if it is not so
621          * marked.
622          */
623         if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED))
624                 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
625                                              SCTP_HEARTBEAT_SUCCESS);
626
627         /* The receiver of the HEARTBEAT ACK should also perform an
628          * RTT measurement for that destination transport address
629          * using the time value carried in the HEARTBEAT ACK chunk.
630          * If the transport's rto_pending variable has been cleared,
631          * it was most likely due to a retransmit.  However, we want
632          * to re-enable it to properly update the rto.
633          */
634         if (t->rto_pending == 0)
635                 t->rto_pending = 1;
636
637         hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
638         sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
639
640         /* Update the heartbeat timer.  */
641         if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
642                 sctp_transport_hold(t);
643 }
644
645 /* Helper function to do a transport reset at the expiry of the hearbeat
646  * timer.
647  */
648 static void sctp_cmd_transport_reset(sctp_cmd_seq_t *cmds,
649                                      struct sctp_association *asoc,
650                                      struct sctp_transport *t)
651 {
652         sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
653
654         /* Mark one strike against a transport.  */
655         sctp_do_8_2_transport_strike(asoc, t);
656 }
657
658 /* Helper function to process the process SACK command.  */
659 static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds,
660                                  struct sctp_association *asoc,
661                                  struct sctp_sackhdr *sackh)
662 {
663         int err;
664
665         if (sctp_outq_sack(&asoc->outqueue, sackh)) {
666                 /* There are no more TSNs awaiting SACK.  */
667                 err = sctp_do_sm(SCTP_EVENT_T_OTHER,
668                                  SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
669                                  asoc->state, asoc->ep, asoc, NULL,
670                                  GFP_ATOMIC);
671         } else {
672                 /* Windows may have opened, so we need
673                  * to check if we have DATA to transmit
674                  */
675                 err = sctp_outq_flush(&asoc->outqueue, 0);
676         }
677
678         return err;
679 }
680
681 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
682  * the transport for a shutdown chunk.
683  */
684 static void sctp_cmd_setup_t2(sctp_cmd_seq_t *cmds,
685                               struct sctp_association *asoc,
686                               struct sctp_chunk *chunk)
687 {
688         struct sctp_transport *t;
689
690         t = sctp_assoc_choose_shutdown_transport(asoc);
691         asoc->shutdown_last_sent_to = t;
692         asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
693         chunk->transport = t;
694 }
695
696 /* Helper function to change the state of an association. */
697 static void sctp_cmd_new_state(sctp_cmd_seq_t *cmds,
698                                struct sctp_association *asoc,
699                                sctp_state_t state)
700 {
701         struct sock *sk = asoc->base.sk;
702
703         asoc->state = state;
704
705         SCTP_DEBUG_PRINTK("sctp_cmd_new_state: asoc %p[%s]\n",
706                           asoc, sctp_state_tbl[state]);
707
708         if (sctp_style(sk, TCP)) {
709                 /* Change the sk->sk_state of a TCP-style socket that has
710                  * sucessfully completed a connect() call.
711                  */
712                 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
713                         sk->sk_state = SCTP_SS_ESTABLISHED;
714
715                 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
716                 if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
717                     sctp_sstate(sk, ESTABLISHED))
718                         sk->sk_shutdown |= RCV_SHUTDOWN;
719         }
720
721         if (sctp_state(asoc, COOKIE_WAIT)) {
722                 /* Reset init timeouts since they may have been
723                  * increased due to timer expirations.
724                  */
725                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
726                                                 asoc->rto_initial;
727                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
728                                                 asoc->rto_initial;
729         }
730
731         if (sctp_state(asoc, ESTABLISHED) ||
732             sctp_state(asoc, CLOSED) ||
733             sctp_state(asoc, SHUTDOWN_RECEIVED)) {
734                 /* Wake up any processes waiting in the asoc's wait queue in
735                  * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
736                  */
737                 if (waitqueue_active(&asoc->wait))
738                         wake_up_interruptible(&asoc->wait);
739
740                 /* Wake up any processes waiting in the sk's sleep queue of
741                  * a TCP-style or UDP-style peeled-off socket in
742                  * sctp_wait_for_accept() or sctp_wait_for_packet().
743                  * For a UDP-style socket, the waiters are woken up by the
744                  * notifications.
745                  */
746                 if (!sctp_style(sk, UDP))
747                         sk->sk_state_change(sk);
748         }
749 }
750
751 /* Helper function to delete an association. */
752 static void sctp_cmd_delete_tcb(sctp_cmd_seq_t *cmds,
753                                 struct sctp_association *asoc)
754 {
755         struct sock *sk = asoc->base.sk;
756
757         /* If it is a non-temporary association belonging to a TCP-style
758          * listening socket that is not closed, do not free it so that accept()
759          * can pick it up later.
760          */
761         if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
762             (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
763                 return;
764
765         sctp_unhash_established(asoc);
766         sctp_association_free(asoc);
767 }
768
769 /*
770  * ADDIP Section 4.1 ASCONF Chunk Procedures
771  * A4) Start a T-4 RTO timer, using the RTO value of the selected
772  * destination address (we use active path instead of primary path just
773  * because primary path may be inactive.
774  */
775 static void sctp_cmd_setup_t4(sctp_cmd_seq_t *cmds,
776                                 struct sctp_association *asoc,
777                                 struct sctp_chunk *chunk)
778 {
779         struct sctp_transport *t;
780
781         t = asoc->peer.active_path;
782         asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
783         chunk->transport = t;
784 }
785
786 /* Process an incoming Operation Error Chunk. */
787 static void sctp_cmd_process_operr(sctp_cmd_seq_t *cmds,
788                                    struct sctp_association *asoc,
789                                    struct sctp_chunk *chunk)
790 {
791         struct sctp_operr_chunk *operr_chunk;
792         struct sctp_errhdr *err_hdr;
793
794         operr_chunk = (struct sctp_operr_chunk *)chunk->chunk_hdr;
795         err_hdr = &operr_chunk->err_hdr;
796
797         switch (err_hdr->cause) {
798         case SCTP_ERROR_UNKNOWN_CHUNK:
799         {
800                 struct sctp_chunkhdr *unk_chunk_hdr;
801
802                 unk_chunk_hdr = (struct sctp_chunkhdr *)err_hdr->variable;
803                 switch (unk_chunk_hdr->type) {
804                 /* ADDIP 4.1 A9) If the peer responds to an ASCONF with an
805                  * ERROR chunk reporting that it did not recognized the ASCONF
806                  * chunk type, the sender of the ASCONF MUST NOT send any
807                  * further ASCONF chunks and MUST stop its T-4 timer.
808                  */
809                 case SCTP_CID_ASCONF:
810                         asoc->peer.asconf_capable = 0;
811                         sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
812                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
813                         break;
814                 default:
815                         break;
816                 }
817                 break;
818         }
819         default:
820                 break;
821         }
822 }
823
824 /* Process variable FWDTSN chunk information. */
825 static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq,
826                                     struct sctp_chunk *chunk)
827 {
828         struct sctp_fwdtsn_skip *skip;
829         /* Walk through all the skipped SSNs */
830         sctp_walk_fwdtsn(skip, chunk) {
831                 sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
832         }
833
834         return;
835 }
836
837 /* Helper function to remove the association non-primary peer
838  * transports.
839  */
840 static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
841 {
842         struct sctp_transport *t;
843         struct list_head *pos;
844         struct list_head *temp;
845
846         list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
847                 t = list_entry(pos, struct sctp_transport, transports);
848                 if (!sctp_cmp_addr_exact(&t->ipaddr,
849                                          &asoc->peer.primary_addr)) {
850                         sctp_assoc_del_peer(asoc, &t->ipaddr);
851                 }
852         }
853
854         return;
855 }
856
857 /* Helper function to set sk_err on a 1-1 style socket. */
858 static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
859 {
860         struct sock *sk = asoc->base.sk;
861
862         if (!sctp_style(sk, UDP))
863                 sk->sk_err = error;
864 }
865
866 /* Helper function to generate an association change event */
867 static void sctp_cmd_assoc_change(sctp_cmd_seq_t *commands,
868                                  struct sctp_association *asoc,
869                                  u8 state)
870 {
871         struct sctp_ulpevent *ev;
872
873         ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0,
874                                             asoc->c.sinit_num_ostreams,
875                                             asoc->c.sinit_max_instreams,
876                                             NULL, GFP_ATOMIC);
877         if (ev)
878                 sctp_ulpq_tail_event(&asoc->ulpq, ev);
879 }
880
881 /* Helper function to generate an adaptation indication event */
882 static void sctp_cmd_adaptation_ind(sctp_cmd_seq_t *commands,
883                                     struct sctp_association *asoc)
884 {
885         struct sctp_ulpevent *ev;
886
887         ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
888
889         if (ev)
890                 sctp_ulpq_tail_event(&asoc->ulpq, ev);
891 }
892
893 /* These three macros allow us to pull the debugging code out of the
894  * main flow of sctp_do_sm() to keep attention focused on the real
895  * functionality there.
896  */
897 #define DEBUG_PRE \
898         SCTP_DEBUG_PRINTK("sctp_do_sm prefn: " \
899                           "ep %p, %s, %s, asoc %p[%s], %s\n", \
900                           ep, sctp_evttype_tbl[event_type], \
901                           (*debug_fn)(subtype), asoc, \
902                           sctp_state_tbl[state], state_fn->name)
903
904 #define DEBUG_POST \
905         SCTP_DEBUG_PRINTK("sctp_do_sm postfn: " \
906                           "asoc %p, status: %s\n", \
907                           asoc, sctp_status_tbl[status])
908
909 #define DEBUG_POST_SFX \
910         SCTP_DEBUG_PRINTK("sctp_do_sm post sfx: error %d, asoc %p[%s]\n", \
911                           error, asoc, \
912                           sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
913                           sctp_assoc2id(asoc)))?asoc->state:SCTP_STATE_CLOSED])
914
915 /*
916  * This is the master state machine processing function.
917  *
918  * If you want to understand all of lksctp, this is a
919  * good place to start.
920  */
921 int sctp_do_sm(sctp_event_t event_type, sctp_subtype_t subtype,
922                sctp_state_t state,
923                struct sctp_endpoint *ep,
924                struct sctp_association *asoc,
925                void *event_arg,
926                gfp_t gfp)
927 {
928         sctp_cmd_seq_t commands;
929         const sctp_sm_table_entry_t *state_fn;
930         sctp_disposition_t status;
931         int error = 0;
932         typedef const char *(printfn_t)(sctp_subtype_t);
933
934         static printfn_t *table[] = {
935                 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
936         };
937         printfn_t *debug_fn  __attribute__ ((unused)) = table[event_type];
938
939         /* Look up the state function, run it, and then process the
940          * side effects.  These three steps are the heart of lksctp.
941          */
942         state_fn = sctp_sm_lookup_event(event_type, state, subtype);
943
944         sctp_init_cmd_seq(&commands);
945
946         DEBUG_PRE;
947         status = (*state_fn->fn)(ep, asoc, subtype, event_arg, &commands);
948         DEBUG_POST;
949
950         error = sctp_side_effects(event_type, subtype, state,
951                                   ep, asoc, event_arg, status,
952                                   &commands, gfp);
953         DEBUG_POST_SFX;
954
955         return error;
956 }
957
958 #undef DEBUG_PRE
959 #undef DEBUG_POST
960
961 /*****************************************************************
962  * This the master state function side effect processing function.
963  *****************************************************************/
964 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
965                              sctp_state_t state,
966                              struct sctp_endpoint *ep,
967                              struct sctp_association *asoc,
968                              void *event_arg,
969                              sctp_disposition_t status,
970                              sctp_cmd_seq_t *commands,
971                              gfp_t gfp)
972 {
973         int error;
974
975         /* FIXME - Most of the dispositions left today would be categorized
976          * as "exceptional" dispositions.  For those dispositions, it
977          * may not be proper to run through any of the commands at all.
978          * For example, the command interpreter might be run only with
979          * disposition SCTP_DISPOSITION_CONSUME.
980          */
981         if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
982                                                ep, asoc,
983                                                event_arg, status,
984                                                commands, gfp)))
985                 goto bail;
986
987         switch (status) {
988         case SCTP_DISPOSITION_DISCARD:
989                 SCTP_DEBUG_PRINTK("Ignored sctp protocol event - state %d, "
990                                   "event_type %d, event_id %d\n",
991                                   state, event_type, subtype.chunk);
992                 break;
993
994         case SCTP_DISPOSITION_NOMEM:
995                 /* We ran out of memory, so we need to discard this
996                  * packet.
997                  */
998                 /* BUG--we should now recover some memory, probably by
999                  * reneging...
1000                  */
1001                 error = -ENOMEM;
1002                 break;
1003
1004         case SCTP_DISPOSITION_DELETE_TCB:
1005                 /* This should now be a command. */
1006                 break;
1007
1008         case SCTP_DISPOSITION_CONSUME:
1009         case SCTP_DISPOSITION_ABORT:
1010                 /*
1011                  * We should no longer have much work to do here as the
1012                  * real work has been done as explicit commands above.
1013                  */
1014                 break;
1015
1016         case SCTP_DISPOSITION_VIOLATION:
1017                 if (net_ratelimit())
1018                         printk(KERN_ERR "sctp protocol violation state %d "
1019                                "chunkid %d\n", state, subtype.chunk);
1020                 break;
1021
1022         case SCTP_DISPOSITION_NOT_IMPL:
1023                 printk(KERN_WARNING "sctp unimplemented feature in state %d, "
1024                        "event_type %d, event_id %d\n",
1025                        state, event_type, subtype.chunk);
1026                 break;
1027
1028         case SCTP_DISPOSITION_BUG:
1029                 printk(KERN_ERR "sctp bug in state %d, "
1030                        "event_type %d, event_id %d\n",
1031                        state, event_type, subtype.chunk);
1032                 BUG();
1033                 break;
1034
1035         default:
1036                 printk(KERN_ERR "sctp impossible disposition %d "
1037                        "in state %d, event_type %d, event_id %d\n",
1038                        status, state, event_type, subtype.chunk);
1039                 BUG();
1040                 break;
1041         }
1042
1043 bail:
1044         return error;
1045 }
1046
1047 /********************************************************************
1048  * 2nd Level Abstractions
1049  ********************************************************************/
1050
1051 /* This is the side-effect interpreter.  */
1052 static int sctp_cmd_interpreter(sctp_event_t event_type,
1053                                 sctp_subtype_t subtype,
1054                                 sctp_state_t state,
1055                                 struct sctp_endpoint *ep,
1056                                 struct sctp_association *asoc,
1057                                 void *event_arg,
1058                                 sctp_disposition_t status,
1059                                 sctp_cmd_seq_t *commands,
1060                                 gfp_t gfp)
1061 {
1062         int error = 0;
1063         int force;
1064         sctp_cmd_t *cmd;
1065         struct sctp_chunk *new_obj;
1066         struct sctp_chunk *chunk = NULL;
1067         struct sctp_packet *packet;
1068         struct list_head *pos;
1069         struct timer_list *timer;
1070         unsigned long timeout;
1071         struct sctp_transport *t;
1072         struct sctp_sackhdr sackh;
1073         int local_cork = 0;
1074
1075         if (SCTP_EVENT_T_TIMEOUT != event_type)
1076                 chunk = (struct sctp_chunk *) event_arg;
1077
1078         /* Note:  This whole file is a huge candidate for rework.
1079          * For example, each command could either have its own handler, so
1080          * the loop would look like:
1081          *     while (cmds)
1082          *         cmd->handle(x, y, z)
1083          * --jgrimm
1084          */
1085         while (NULL != (cmd = sctp_next_cmd(commands))) {
1086                 switch (cmd->verb) {
1087                 case SCTP_CMD_NOP:
1088                         /* Do nothing. */
1089                         break;
1090
1091                 case SCTP_CMD_NEW_ASOC:
1092                         /* Register a new association.  */
1093                         if (local_cork) {
1094                                 sctp_outq_uncork(&asoc->outqueue);
1095                                 local_cork = 0;
1096                         }
1097                         asoc = cmd->obj.ptr;
1098                         /* Register with the endpoint.  */
1099                         sctp_endpoint_add_asoc(ep, asoc);
1100                         sctp_hash_established(asoc);
1101                         break;
1102
1103                 case SCTP_CMD_UPDATE_ASSOC:
1104                        sctp_assoc_update(asoc, cmd->obj.ptr);
1105                        break;
1106
1107                 case SCTP_CMD_PURGE_OUTQUEUE:
1108                        sctp_outq_teardown(&asoc->outqueue);
1109                        break;
1110
1111                 case SCTP_CMD_DELETE_TCB:
1112                         if (local_cork) {
1113                                 sctp_outq_uncork(&asoc->outqueue);
1114                                 local_cork = 0;
1115                         }
1116                         /* Delete the current association.  */
1117                         sctp_cmd_delete_tcb(commands, asoc);
1118                         asoc = NULL;
1119                         break;
1120
1121                 case SCTP_CMD_NEW_STATE:
1122                         /* Enter a new state.  */
1123                         sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1124                         break;
1125
1126                 case SCTP_CMD_REPORT_TSN:
1127                         /* Record the arrival of a TSN.  */
1128                         sctp_tsnmap_mark(&asoc->peer.tsn_map, cmd->obj.u32);
1129                         break;
1130
1131                 case SCTP_CMD_REPORT_FWDTSN:
1132                         /* Move the Cumulattive TSN Ack ahead. */
1133                         sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32);
1134
1135                         /* purge the fragmentation queue */
1136                         sctp_ulpq_reasm_flushtsn(&asoc->ulpq, cmd->obj.u32);
1137
1138                         /* Abort any in progress partial delivery. */
1139                         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
1140                         break;
1141
1142                 case SCTP_CMD_PROCESS_FWDTSN:
1143                         sctp_cmd_process_fwdtsn(&asoc->ulpq, cmd->obj.ptr);
1144                         break;
1145
1146                 case SCTP_CMD_GEN_SACK:
1147                         /* Generate a Selective ACK.
1148                          * The argument tells us whether to just count
1149                          * the packet and MAYBE generate a SACK, or
1150                          * force a SACK out.
1151                          */
1152                         force = cmd->obj.i32;
1153                         error = sctp_gen_sack(asoc, force, commands);
1154                         break;
1155
1156                 case SCTP_CMD_PROCESS_SACK:
1157                         /* Process an inbound SACK.  */
1158                         error = sctp_cmd_process_sack(commands, asoc,
1159                                                       cmd->obj.ptr);
1160                         break;
1161
1162                 case SCTP_CMD_GEN_INIT_ACK:
1163                         /* Generate an INIT ACK chunk.  */
1164                         new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1165                                                      0);
1166                         if (!new_obj)
1167                                 goto nomem;
1168
1169                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1170                                         SCTP_CHUNK(new_obj));
1171                         break;
1172
1173                 case SCTP_CMD_PEER_INIT:
1174                         /* Process a unified INIT from the peer.
1175                          * Note: Only used during INIT-ACK processing.  If
1176                          * there is an error just return to the outter
1177                          * layer which will bail.
1178                          */
1179                         error = sctp_cmd_process_init(commands, asoc, chunk,
1180                                                       cmd->obj.ptr, gfp);
1181                         break;
1182
1183                 case SCTP_CMD_GEN_COOKIE_ECHO:
1184                         /* Generate a COOKIE ECHO chunk.  */
1185                         new_obj = sctp_make_cookie_echo(asoc, chunk);
1186                         if (!new_obj) {
1187                                 if (cmd->obj.ptr)
1188                                         sctp_chunk_free(cmd->obj.ptr);
1189                                 goto nomem;
1190                         }
1191                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1192                                         SCTP_CHUNK(new_obj));
1193
1194                         /* If there is an ERROR chunk to be sent along with
1195                          * the COOKIE_ECHO, send it, too.
1196                          */
1197                         if (cmd->obj.ptr)
1198                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1199                                                 SCTP_CHUNK(cmd->obj.ptr));
1200
1201                         /* FIXME - Eventually come up with a cleaner way to
1202                          * enabling COOKIE-ECHO + DATA bundling during
1203                          * multihoming stale cookie scenarios, the following
1204                          * command plays with asoc->peer.retran_path to
1205                          * avoid the problem of sending the COOKIE-ECHO and
1206                          * DATA in different paths, which could result
1207                          * in the association being ABORTed if the DATA chunk
1208                          * is processed first by the server.  Checking the
1209                          * init error counter simply causes this command
1210                          * to be executed only during failed attempts of
1211                          * association establishment.
1212                          */
1213                         if ((asoc->peer.retran_path !=
1214                              asoc->peer.primary_path) &&
1215                             (asoc->init_err_counter > 0)) {
1216                                 sctp_add_cmd_sf(commands,
1217                                                 SCTP_CMD_FORCE_PRIM_RETRAN,
1218                                                 SCTP_NULL());
1219                         }
1220
1221                         break;
1222
1223                 case SCTP_CMD_GEN_SHUTDOWN:
1224                         /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1225                          * Reset error counts.
1226                          */
1227                         asoc->overall_error_count = 0;
1228
1229                         /* Generate a SHUTDOWN chunk.  */
1230                         new_obj = sctp_make_shutdown(asoc, chunk);
1231                         if (!new_obj)
1232                                 goto nomem;
1233                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1234                                         SCTP_CHUNK(new_obj));
1235                         break;
1236
1237                 case SCTP_CMD_CHUNK_ULP:
1238                         /* Send a chunk to the sockets layer.  */
1239                         SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1240                                           "chunk_up:", cmd->obj.ptr,
1241                                           "ulpq:", &asoc->ulpq);
1242                         sctp_ulpq_tail_data(&asoc->ulpq, cmd->obj.ptr,
1243                                             GFP_ATOMIC);
1244                         break;
1245
1246                 case SCTP_CMD_EVENT_ULP:
1247                         /* Send a notification to the sockets layer.  */
1248                         SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1249                                           "event_up:",cmd->obj.ptr,
1250                                           "ulpq:",&asoc->ulpq);
1251                         sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ptr);
1252                         break;
1253
1254                 case SCTP_CMD_REPLY:
1255                         /* If an caller has not already corked, do cork. */
1256                         if (!asoc->outqueue.cork) {
1257                                 sctp_outq_cork(&asoc->outqueue);
1258                                 local_cork = 1;
1259                         }
1260                         /* Send a chunk to our peer.  */
1261                         error = sctp_outq_tail(&asoc->outqueue, cmd->obj.ptr);
1262                         break;
1263
1264                 case SCTP_CMD_SEND_PKT:
1265                         /* Send a full packet to our peer.  */
1266                         packet = cmd->obj.ptr;
1267                         sctp_packet_transmit(packet);
1268                         sctp_ootb_pkt_free(packet);
1269                         break;
1270
1271                 case SCTP_CMD_T1_RETRAN:
1272                         /* Mark a transport for retransmission.  */
1273                         sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1274                                         SCTP_RTXR_T1_RTX);
1275                         break;
1276
1277                 case SCTP_CMD_RETRAN:
1278                         /* Mark a transport for retransmission.  */
1279                         sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1280                                         SCTP_RTXR_T3_RTX);
1281                         break;
1282
1283                 case SCTP_CMD_TRANSMIT:
1284                         /* Kick start transmission. */
1285                         error = sctp_outq_uncork(&asoc->outqueue);
1286                         local_cork = 0;
1287                         break;
1288
1289                 case SCTP_CMD_ECN_CE:
1290                         /* Do delayed CE processing.   */
1291                         sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1292                         break;
1293
1294                 case SCTP_CMD_ECN_ECNE:
1295                         /* Do delayed ECNE processing. */
1296                         new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1297                                                         chunk);
1298                         if (new_obj)
1299                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1300                                                 SCTP_CHUNK(new_obj));
1301                         break;
1302
1303                 case SCTP_CMD_ECN_CWR:
1304                         /* Do delayed CWR processing.  */
1305                         sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1306                         break;
1307
1308                 case SCTP_CMD_SETUP_T2:
1309                         sctp_cmd_setup_t2(commands, asoc, cmd->obj.ptr);
1310                         break;
1311
1312                 case SCTP_CMD_TIMER_START:
1313                         timer = &asoc->timers[cmd->obj.to];
1314                         timeout = asoc->timeouts[cmd->obj.to];
1315                         BUG_ON(!timeout);
1316
1317                         timer->expires = jiffies + timeout;
1318                         sctp_association_hold(asoc);
1319                         add_timer(timer);
1320                         break;
1321
1322                 case SCTP_CMD_TIMER_RESTART:
1323                         timer = &asoc->timers[cmd->obj.to];
1324                         timeout = asoc->timeouts[cmd->obj.to];
1325                         if (!mod_timer(timer, jiffies + timeout))
1326                                 sctp_association_hold(asoc);
1327                         break;
1328
1329                 case SCTP_CMD_TIMER_STOP:
1330                         timer = &asoc->timers[cmd->obj.to];
1331                         if (timer_pending(timer) && del_timer(timer))
1332                                 sctp_association_put(asoc);
1333                         break;
1334
1335                 case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1336                         chunk = cmd->obj.ptr;
1337                         t = sctp_assoc_choose_init_transport(asoc);
1338                         asoc->init_last_sent_to = t;
1339                         chunk->transport = t;
1340                         t->init_sent_count++;
1341                         break;
1342
1343                 case SCTP_CMD_INIT_RESTART:
1344                         /* Do the needed accounting and updates
1345                          * associated with restarting an initialization
1346                          * timer. Only multiply the timeout by two if
1347                          * all transports have been tried at the current
1348                          * timeout.
1349                          */
1350                         t = asoc->init_last_sent_to;
1351                         asoc->init_err_counter++;
1352
1353                         if (t->init_sent_count > (asoc->init_cycle + 1)) {
1354                                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] *= 2;
1355                                 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] >
1356                                     asoc->max_init_timeo) {
1357                                         asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
1358                                                 asoc->max_init_timeo;
1359                                 }
1360                                 asoc->init_cycle++;
1361                                 SCTP_DEBUG_PRINTK(
1362                                         "T1 INIT Timeout adjustment"
1363                                         " init_err_counter: %d"
1364                                         " cycle: %d"
1365                                         " timeout: %ld\n",
1366                                         asoc->init_err_counter,
1367                                         asoc->init_cycle,
1368                                         asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT]);
1369                         }
1370
1371                         sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1372                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1373                         break;
1374
1375                 case SCTP_CMD_COOKIEECHO_RESTART:
1376                         /* Do the needed accounting and updates
1377                          * associated with restarting an initialization
1378                          * timer. Only multiply the timeout by two if
1379                          * all transports have been tried at the current
1380                          * timeout.
1381                          */
1382                         asoc->init_err_counter++;
1383
1384                         asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] *= 2;
1385                         if (asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] >
1386                             asoc->max_init_timeo) {
1387                                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
1388                                         asoc->max_init_timeo;
1389                         }
1390                         SCTP_DEBUG_PRINTK(
1391                                 "T1 COOKIE Timeout adjustment"
1392                                 " init_err_counter: %d"
1393                                 " timeout: %ld\n",
1394                                 asoc->init_err_counter,
1395                                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE]);
1396
1397                         /* If we've sent any data bundled with
1398                          * COOKIE-ECHO we need to resend.
1399                          */
1400                         list_for_each(pos, &asoc->peer.transport_addr_list) {
1401                                 t = list_entry(pos, struct sctp_transport,
1402                                                transports);
1403                                 sctp_retransmit_mark(&asoc->outqueue, t,
1404                                             SCTP_RTXR_T1_RTX);
1405                         }
1406
1407                         sctp_add_cmd_sf(commands,
1408                                         SCTP_CMD_TIMER_RESTART,
1409                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1410                         break;
1411
1412                 case SCTP_CMD_INIT_FAILED:
1413                         sctp_cmd_init_failed(commands, asoc, cmd->obj.err);
1414                         break;
1415
1416                 case SCTP_CMD_ASSOC_FAILED:
1417                         sctp_cmd_assoc_failed(commands, asoc, event_type,
1418                                               subtype, chunk, cmd->obj.err);
1419                         break;
1420
1421                 case SCTP_CMD_INIT_COUNTER_INC:
1422                         asoc->init_err_counter++;
1423                         break;
1424
1425                 case SCTP_CMD_INIT_COUNTER_RESET:
1426                         asoc->init_err_counter = 0;
1427                         asoc->init_cycle = 0;
1428                         break;
1429
1430                 case SCTP_CMD_REPORT_DUP:
1431                         sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1432                                              cmd->obj.u32);
1433                         break;
1434
1435                 case SCTP_CMD_REPORT_BAD_TAG:
1436                         SCTP_DEBUG_PRINTK("vtag mismatch!\n");
1437                         break;
1438
1439                 case SCTP_CMD_STRIKE:
1440                         /* Mark one strike against a transport.  */
1441                         sctp_do_8_2_transport_strike(asoc, cmd->obj.transport);
1442                         break;
1443
1444                 case SCTP_CMD_TRANSPORT_RESET:
1445                         t = cmd->obj.transport;
1446                         sctp_cmd_transport_reset(commands, asoc, t);
1447                         break;
1448
1449                 case SCTP_CMD_TRANSPORT_ON:
1450                         t = cmd->obj.transport;
1451                         sctp_cmd_transport_on(commands, asoc, t, chunk);
1452                         break;
1453
1454                 case SCTP_CMD_HB_TIMERS_START:
1455                         sctp_cmd_hb_timers_start(commands, asoc);
1456                         break;
1457
1458                 case SCTP_CMD_HB_TIMER_UPDATE:
1459                         t = cmd->obj.transport;
1460                         sctp_cmd_hb_timer_update(commands, asoc, t);
1461                         break;
1462
1463                 case SCTP_CMD_HB_TIMERS_STOP:
1464                         sctp_cmd_hb_timers_stop(commands, asoc);
1465                         break;
1466
1467                 case SCTP_CMD_REPORT_ERROR:
1468                         error = cmd->obj.error;
1469                         break;
1470
1471                 case SCTP_CMD_PROCESS_CTSN:
1472                         /* Dummy up a SACK for processing. */
1473                         sackh.cum_tsn_ack = cmd->obj.be32;
1474                         sackh.a_rwnd = 0;
1475                         sackh.num_gap_ack_blocks = 0;
1476                         sackh.num_dup_tsns = 0;
1477                         sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1478                                         SCTP_SACKH(&sackh));
1479                         break;
1480
1481                 case SCTP_CMD_DISCARD_PACKET:
1482                         /* We need to discard the whole packet.  */
1483                         chunk->pdiscard = 1;
1484                         break;
1485
1486                 case SCTP_CMD_RTO_PENDING:
1487                         t = cmd->obj.transport;
1488                         t->rto_pending = 1;
1489                         break;
1490
1491                 case SCTP_CMD_PART_DELIVER:
1492                         sctp_ulpq_partial_delivery(&asoc->ulpq, cmd->obj.ptr,
1493                                                    GFP_ATOMIC);
1494                         break;
1495
1496                 case SCTP_CMD_RENEGE:
1497                         sctp_ulpq_renege(&asoc->ulpq, cmd->obj.ptr,
1498                                          GFP_ATOMIC);
1499                         break;
1500
1501                 case SCTP_CMD_SETUP_T4:
1502                         sctp_cmd_setup_t4(commands, asoc, cmd->obj.ptr);
1503                         break;
1504
1505                 case SCTP_CMD_PROCESS_OPERR:
1506                         sctp_cmd_process_operr(commands, asoc, chunk);
1507                         break;
1508                 case SCTP_CMD_CLEAR_INIT_TAG:
1509                         asoc->peer.i.init_tag = 0;
1510                         break;
1511                 case SCTP_CMD_DEL_NON_PRIMARY:
1512                         sctp_cmd_del_non_primary(asoc);
1513                         break;
1514                 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1515                         sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1516                         break;
1517                 case SCTP_CMD_FORCE_PRIM_RETRAN:
1518                         t = asoc->peer.retran_path;
1519                         asoc->peer.retran_path = asoc->peer.primary_path;
1520                         error = sctp_outq_uncork(&asoc->outqueue);
1521                         local_cork = 0;
1522                         asoc->peer.retran_path = t;
1523                         break;
1524                 case SCTP_CMD_SET_SK_ERR:
1525                         sctp_cmd_set_sk_err(asoc, cmd->obj.error);
1526                         break;
1527                 case SCTP_CMD_ASSOC_CHANGE:
1528                         sctp_cmd_assoc_change(commands, asoc,
1529                                               cmd->obj.u8);
1530                         break;
1531                 case SCTP_CMD_ADAPTATION_IND:
1532                         sctp_cmd_adaptation_ind(commands, asoc);
1533                         break;
1534
1535                 case SCTP_CMD_ASSOC_SHKEY:
1536                         error = sctp_auth_asoc_init_active_key(asoc,
1537                                                 GFP_ATOMIC);
1538                         break;
1539
1540                 default:
1541                         printk(KERN_WARNING "Impossible command: %u, %p\n",
1542                                cmd->verb, cmd->obj.ptr);
1543                         break;
1544                 }
1545
1546                 if (error)
1547                         break;
1548         }
1549
1550 out:
1551         if (local_cork)
1552                 sctp_outq_uncork(&asoc->outqueue);
1553         return error;
1554 nomem:
1555         error = -ENOMEM;
1556         goto out;
1557 }
1558