ftp://ftp.kernel.org/pub/linux/kernel/v2.6/linux-2.6.6.tar.bz2
[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 /********************************************************************
59  * Helper functions
60  ********************************************************************/
61
62 /* A helper function for delayed processing of INET ECN CE bit. */
63 static void sctp_do_ecn_ce_work(struct sctp_association *asoc, 
64                                 __u32 lowest_tsn)
65 {
66         /* Save the TSN away for comparison when we receive CWR */
67
68         asoc->last_ecne_tsn = lowest_tsn;
69         asoc->need_ecne = 1;
70 }
71
72 /* Helper function for delayed processing of SCTP ECNE chunk.  */
73 /* RFC 2960 Appendix A
74  *
75  * RFC 2481 details a specific bit for a sender to send in
76  * the header of its next outbound TCP segment to indicate to
77  * its peer that it has reduced its congestion window.  This
78  * is termed the CWR bit.  For SCTP the same indication is made
79  * by including the CWR chunk.  This chunk contains one data
80  * element, i.e. the TSN number that was sent in the ECNE chunk.
81  * This element represents the lowest TSN number in the datagram
82  * that was originally marked with the CE bit.
83  */
84 static struct sctp_chunk *sctp_do_ecn_ecne_work(struct sctp_association *asoc,
85                                            __u32 lowest_tsn,
86                                            struct sctp_chunk *chunk)
87 {
88         struct sctp_chunk *repl;
89
90         /* Our previously transmitted packet ran into some congestion
91          * so we should take action by reducing cwnd and ssthresh
92          * and then ACK our peer that we we've done so by
93          * sending a CWR.
94          */
95
96         /* First, try to determine if we want to actually lower
97          * our cwnd variables.  Only lower them if the ECNE looks more
98          * recent than the last response.
99          */
100         if (TSN_lt(asoc->last_cwr_tsn, lowest_tsn)) {
101                 struct sctp_transport *transport;
102
103                 /* Find which transport's congestion variables
104                  * need to be adjusted.
105                  */
106                 transport = sctp_assoc_lookup_tsn(asoc, lowest_tsn);
107
108                 /* Update the congestion variables. */
109                 if (transport)
110                         sctp_transport_lower_cwnd(transport,
111                                                   SCTP_LOWER_CWND_ECNE);
112                 asoc->last_cwr_tsn = lowest_tsn;
113         }
114
115         /* Always try to quiet the other end.  In case of lost CWR,
116          * resend last_cwr_tsn.
117          */
118         repl = sctp_make_cwr(asoc, asoc->last_cwr_tsn, chunk);
119
120         /* If we run out of memory, it will look like a lost CWR.  We'll
121          * get back in sync eventually.
122          */
123         return repl;
124 }
125
126 /* Helper function to do delayed processing of ECN CWR chunk.  */
127 static void sctp_do_ecn_cwr_work(struct sctp_association *asoc,
128                                  __u32 lowest_tsn)
129 {
130         /* Turn off ECNE getting auto-prepended to every outgoing
131          * packet
132          */
133         asoc->need_ecne = 0;
134 }
135
136 /* Generate SACK if necessary.  We call this at the end of a packet.  */
137 int sctp_gen_sack(struct sctp_association *asoc, int force,
138                   sctp_cmd_seq_t *commands)
139 {
140         __u32 ctsn, max_tsn_seen;
141         struct sctp_chunk *sack;
142         int error = 0;
143
144         if (force)
145                 asoc->peer.sack_needed = 1;
146
147         ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
148         max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
149
150         /* From 12.2 Parameters necessary per association (i.e. the TCB):
151          *
152          * Ack State : This flag indicates if the next received packet
153          *           : is to be responded to with a SACK. ...
154          *           : When DATA chunks are out of order, SACK's
155          *           : are not delayed (see Section 6).
156          *
157          * [This is actually not mentioned in Section 6, but we
158          * implement it here anyway. --piggy]
159          */
160         if (max_tsn_seen != ctsn)
161                 asoc->peer.sack_needed = 1;
162
163         /* From 6.2  Acknowledgement on Reception of DATA Chunks:
164          *
165          * Section 4.2 of [RFC2581] SHOULD be followed. Specifically,
166          * an acknowledgement SHOULD be generated for at least every
167          * second packet (not every second DATA chunk) received, and
168          * SHOULD be generated within 200 ms of the arrival of any
169          * unacknowledged DATA chunk. ...
170          */
171         if (!asoc->peer.sack_needed) {
172                 /* We will need a SACK for the next packet.  */
173                 asoc->peer.sack_needed = 1;
174                 goto out;
175         } else {
176                 if (asoc->a_rwnd > asoc->rwnd)
177                         asoc->a_rwnd = asoc->rwnd;
178                 sack = sctp_make_sack(asoc);
179                 if (!sack)
180                         goto nomem;
181
182                 asoc->peer.sack_needed = 0;
183
184                 error = sctp_outq_tail(&asoc->outqueue, sack);
185
186                 /* Stop the SACK timer.  */
187                 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
188                                 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
189         }
190 out:
191         return error;
192 nomem:
193         error = -ENOMEM;
194         return error;
195 }
196
197 /* When the T3-RTX timer expires, it calls this function to create the
198  * relevant state machine event.
199  */
200 void sctp_generate_t3_rtx_event(unsigned long peer)
201 {
202         int error;
203         struct sctp_transport *transport = (struct sctp_transport *) peer;
204         struct sctp_association *asoc = transport->asoc;
205
206         /* Check whether a task is in the sock.  */
207
208         sctp_bh_lock_sock(asoc->base.sk);
209         if (sock_owned_by_user(asoc->base.sk)) {
210                 SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __FUNCTION__);
211
212                 /* Try again later.  */
213                 if (!mod_timer(&transport->T3_rtx_timer, jiffies + (HZ/20)))
214                         sctp_transport_hold(transport);
215                 goto out_unlock;
216         }
217
218         /* Is this transport really dead and just waiting around for
219          * the timer to let go of the reference?
220          */
221         if (transport->dead)
222                 goto out_unlock;
223
224         /* Run through the state machine.  */
225         error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
226                            SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX),
227                            asoc->state,
228                            asoc->ep, asoc,
229                            transport, GFP_ATOMIC);
230
231         if (error)
232                 asoc->base.sk->sk_err = -error;
233
234 out_unlock:
235         sctp_bh_unlock_sock(asoc->base.sk);
236         sctp_transport_put(transport);
237 }
238
239 /* This is a sa interface for producing timeout events.  It works
240  * for timeouts which use the association as their parameter.
241  */
242 static void sctp_generate_timeout_event(struct sctp_association *asoc,
243                                         sctp_event_timeout_t timeout_type)
244 {
245         int error = 0;
246
247         sctp_bh_lock_sock(asoc->base.sk);
248         if (sock_owned_by_user(asoc->base.sk)) {
249                 SCTP_DEBUG_PRINTK("%s:Sock is busy: timer %d\n",
250                                   __FUNCTION__,
251                                   timeout_type);
252
253                 /* Try again later.  */
254                 if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20)))
255                         sctp_association_hold(asoc);
256                 goto out_unlock;
257         }
258
259         /* Is this association really dead and just waiting around for
260          * the timer to let go of the reference?
261          */
262         if (asoc->base.dead)
263                 goto out_unlock;
264
265         /* Run through the state machine.  */
266         error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
267                            SCTP_ST_TIMEOUT(timeout_type),
268                            asoc->state, asoc->ep, asoc,
269                            (void *)timeout_type, GFP_ATOMIC);
270
271         if (error)
272                 asoc->base.sk->sk_err = -error;
273
274 out_unlock:
275         sctp_bh_unlock_sock(asoc->base.sk);
276         sctp_association_put(asoc);
277 }
278
279 void sctp_generate_t1_cookie_event(unsigned long data)
280 {
281         struct sctp_association *asoc = (struct sctp_association *) data;
282         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
283 }
284
285 void sctp_generate_t1_init_event(unsigned long data)
286 {
287         struct sctp_association *asoc = (struct sctp_association *) data;
288         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
289 }
290
291 void sctp_generate_t2_shutdown_event(unsigned long data)
292 {
293         struct sctp_association *asoc = (struct sctp_association *) data;
294         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
295 }
296
297 void sctp_generate_t4_rto_event(unsigned long data)
298 {
299         struct sctp_association *asoc = (struct sctp_association *) data;
300         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
301 }
302
303 void sctp_generate_t5_shutdown_guard_event(unsigned long data)
304 {
305         struct sctp_association *asoc = (struct sctp_association *)data;
306         sctp_generate_timeout_event(asoc,
307                                     SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);
308
309 } /* sctp_generate_t5_shutdown_guard_event() */
310
311 void sctp_generate_autoclose_event(unsigned long data)
312 {
313         struct sctp_association *asoc = (struct sctp_association *) data;
314         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE);
315 }
316
317 /* Generate a heart beat event.  If the sock is busy, reschedule.   Make
318  * sure that the transport is still valid.
319  */
320 void sctp_generate_heartbeat_event(unsigned long data)
321 {
322         int error = 0;
323         struct sctp_transport *transport = (struct sctp_transport *) data;
324         struct sctp_association *asoc = transport->asoc;
325
326         sctp_bh_lock_sock(asoc->base.sk);
327         if (sock_owned_by_user(asoc->base.sk)) {
328                 SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __FUNCTION__);
329
330                 /* Try again later.  */
331                 if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20)))
332                         sctp_transport_hold(transport);
333                 goto out_unlock;
334         }
335
336         /* Is this structure just waiting around for us to actually
337          * get destroyed?
338          */
339         if (transport->dead)
340                 goto out_unlock;
341
342         error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
343                            SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
344                            asoc->state, asoc->ep, asoc,
345                            transport, GFP_ATOMIC);
346
347          if (error)
348                  asoc->base.sk->sk_err = -error;
349
350 out_unlock:
351         sctp_bh_unlock_sock(asoc->base.sk);
352         sctp_transport_put(transport);
353 }
354
355 /* Inject a SACK Timeout event into the state machine.  */
356 void sctp_generate_sack_event(unsigned long data)
357 {
358         struct sctp_association *asoc = (struct sctp_association *) data;
359         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
360 }
361
362 sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
363         NULL,
364         sctp_generate_t1_cookie_event,
365         sctp_generate_t1_init_event,
366         sctp_generate_t2_shutdown_event,
367         NULL,
368         sctp_generate_t4_rto_event,
369         sctp_generate_t5_shutdown_guard_event,
370         sctp_generate_heartbeat_event,
371         sctp_generate_sack_event,
372         sctp_generate_autoclose_event,
373 };
374
375
376 /* RFC 2960 8.2 Path Failure Detection
377  *
378  * When its peer endpoint is multi-homed, an endpoint should keep a
379  * error counter for each of the destination transport addresses of the
380  * peer endpoint.
381  *
382  * Each time the T3-rtx timer expires on any address, or when a
383  * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
384  * the error counter of that destination address will be incremented.
385  * When the value in the error counter exceeds the protocol parameter
386  * 'Path.Max.Retrans' of that destination address, the endpoint should
387  * mark the destination transport address as inactive, and a
388  * notification SHOULD be sent to the upper layer.
389  *
390  */
391 static void sctp_do_8_2_transport_strike(struct sctp_association *asoc,
392                                          struct sctp_transport *transport)
393 {
394         /* The check for association's overall error counter exceeding the
395          * threshold is done in the state function.
396          */
397         asoc->overall_error_count++;
398
399         if (transport->active &&
400             (transport->error_count++ >= transport->error_threshold)) {
401                 SCTP_DEBUG_PRINTK("transport_strike: transport "
402                                   "IP:%d.%d.%d.%d failed.\n",
403                                   NIPQUAD(transport->ipaddr.v4.sin_addr));
404                 sctp_assoc_control_transport(asoc, transport,
405                                              SCTP_TRANSPORT_DOWN,
406                                              SCTP_FAILED_THRESHOLD);
407         }
408
409         /* E2) For the destination address for which the timer
410          * expires, set RTO <- RTO * 2 ("back off the timer").  The
411          * maximum value discussed in rule C7 above (RTO.max) may be
412          * used to provide an upper bound to this doubling operation.
413          */
414         transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
415 }
416
417 /* Worker routine to handle INIT command failure.  */
418 static void sctp_cmd_init_failed(sctp_cmd_seq_t *commands,
419                                  struct sctp_association *asoc,
420                                  unsigned error)
421 {
422         struct sctp_ulpevent *event;
423
424         event = sctp_ulpevent_make_assoc_change(asoc,0, SCTP_CANT_STR_ASSOC,
425                                                 (__u16)error, 0, 0,
426                                                 GFP_ATOMIC);
427
428         if (event)
429                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
430                                 SCTP_ULPEVENT(event));
431
432         /* SEND_FAILED sent later when cleaning up the association. */
433         asoc->outqueue.error = error;
434         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
435 }
436
437 /* Worker routine to handle SCTP_CMD_ASSOC_FAILED.  */
438 static void sctp_cmd_assoc_failed(sctp_cmd_seq_t *commands,
439                                   struct sctp_association *asoc,
440                                   sctp_event_t event_type,
441                                   sctp_subtype_t subtype,
442                                   struct sctp_chunk *chunk,
443                                   unsigned error)
444 {
445         struct sctp_ulpevent *event;
446
447         /* Cancel any partial delivery in progress. */
448         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
449
450         event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
451                                                 (__u16)error, 0, 0,
452                                                 GFP_ATOMIC);
453         if (event)
454                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
455                                 SCTP_ULPEVENT(event));
456
457         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
458                         SCTP_STATE(SCTP_STATE_CLOSED));
459
460         /* SEND_FAILED sent later when cleaning up the association. */
461         asoc->outqueue.error = error;
462         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
463 }
464
465 /* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
466  * inside the cookie.  In reality, this is only used for INIT-ACK processing
467  * since all other cases use "temporary" associations and can do all
468  * their work in statefuns directly.
469  */
470 static int sctp_cmd_process_init(sctp_cmd_seq_t *commands,
471                                  struct sctp_association *asoc,
472                                  struct sctp_chunk *chunk,
473                                  sctp_init_chunk_t *peer_init, int gfp)
474 {
475         int error;
476
477         /* We only process the init as a sideeffect in a single
478          * case.   This is when we process the INIT-ACK.   If we
479          * fail during INIT processing (due to malloc problems),
480          * just return the error and stop processing the stack.
481          */
482         if (!sctp_process_init(asoc, chunk->chunk_hdr->type,
483                                sctp_source(chunk), peer_init, gfp))
484                 error = -ENOMEM;
485         else
486                 error = 0;
487
488         return error;
489 }
490
491 /* Helper function to break out starting up of heartbeat timers.  */
492 static void sctp_cmd_hb_timers_start(sctp_cmd_seq_t *cmds,
493                                      struct sctp_association *asoc)
494 {
495         struct sctp_transport *t;
496         struct list_head *pos;
497
498         /* Start a heartbeat timer for each transport on the association.
499          * hold a reference on the transport to make sure none of
500          * the needed data structures go away.
501          */
502         list_for_each(pos, &asoc->peer.transport_addr_list) {
503                 t = list_entry(pos, struct sctp_transport, transports);
504
505                 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
506                         sctp_transport_hold(t);
507         }
508 }
509
510 static void sctp_cmd_hb_timers_stop(sctp_cmd_seq_t *cmds,
511                                     struct sctp_association *asoc)
512 {
513         struct sctp_transport *t;
514         struct list_head *pos;
515
516         /* Stop all heartbeat timers. */
517
518         list_for_each(pos, &asoc->peer.transport_addr_list) {
519                 t = list_entry(pos, struct sctp_transport, transports);
520                 if (del_timer(&t->hb_timer))
521                         sctp_transport_put(t);
522         }
523 }
524
525 /* Helper function to update the heartbeat timer. */
526 static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
527                                      struct sctp_association *asoc,
528                                      struct sctp_transport *t)
529 {
530         /* Update the heartbeat timer.  */
531         if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
532                 sctp_transport_hold(t);
533 }
534
535 /* Helper function to handle the reception of an HEARTBEAT ACK.  */
536 static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds,
537                                   struct sctp_association *asoc,
538                                   struct sctp_transport *t,
539                                   struct sctp_chunk *chunk)
540 {
541         sctp_sender_hb_info_t *hbinfo;
542
543         /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
544          * HEARTBEAT should clear the error counter of the destination
545          * transport address to which the HEARTBEAT was sent.
546          * The association's overall error count is also cleared.
547          */
548         t->error_count = 0;
549         t->asoc->overall_error_count = 0;
550
551         /* Mark the destination transport address as active if it is not so
552          * marked.
553          */
554         if (!t->active)
555                 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
556                                              SCTP_HEARTBEAT_SUCCESS);
557
558         /* The receiver of the HEARTBEAT ACK should also perform an
559          * RTT measurement for that destination transport address
560          * using the time value carried in the HEARTBEAT ACK chunk.
561          */
562         hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
563         sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
564 }
565
566 /* Helper function to do a transport reset at the expiry of the hearbeat
567  * timer.
568  */
569 static void sctp_cmd_transport_reset(sctp_cmd_seq_t *cmds,
570                                      struct sctp_association *asoc,
571                                      struct sctp_transport *t)
572 {
573         sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
574
575         /* Mark one strike against a transport.  */
576         sctp_do_8_2_transport_strike(asoc, t);
577 }
578
579 /* Helper function to process the process SACK command.  */
580 static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds,
581                                  struct sctp_association *asoc,
582                                  struct sctp_sackhdr *sackh)
583 {
584         int err;
585
586         if (sctp_outq_sack(&asoc->outqueue, sackh)) {
587                 /* There are no more TSNs awaiting SACK.  */
588                 err = sctp_do_sm(SCTP_EVENT_T_OTHER,
589                                  SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
590                                  asoc->state, asoc->ep, asoc, NULL,
591                                  GFP_ATOMIC);
592         } else {
593                 /* Windows may have opened, so we need
594                  * to check if we have DATA to transmit
595                  */
596                 err = sctp_outq_flush(&asoc->outqueue, 0);
597         }
598
599         return err;
600 }
601
602 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
603  * the transport for a shutdown chunk.
604  */
605 static void sctp_cmd_setup_t2(sctp_cmd_seq_t *cmds, 
606                               struct sctp_association *asoc,
607                               struct sctp_chunk *chunk)
608 {
609         struct sctp_transport *t;
610
611         t = sctp_assoc_choose_shutdown_transport(asoc);
612         asoc->shutdown_last_sent_to = t;
613         asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
614         chunk->transport = t;
615 }
616
617 /* Helper function to change the state of an association. */
618 static void sctp_cmd_new_state(sctp_cmd_seq_t *cmds, 
619                                struct sctp_association *asoc,
620                                sctp_state_t state)
621 {
622         struct sock *sk = asoc->base.sk;
623
624         asoc->state = state;
625
626         if (sctp_style(sk, TCP)) {
627                 /* Change the sk->sk_state of a TCP-style socket that has 
628                  * sucessfully completed a connect() call.
629                  */
630                 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
631                         sk->sk_state = SCTP_SS_ESTABLISHED;
632
633                 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
634                 if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
635                     sctp_sstate(sk, ESTABLISHED))
636                         sk->sk_shutdown |= RCV_SHUTDOWN;
637         }
638
639         if (sctp_state(asoc, ESTABLISHED) ||
640             sctp_state(asoc, CLOSED) ||
641             sctp_state(asoc, SHUTDOWN_RECEIVED)) {
642                 /* Wake up any processes waiting in the asoc's wait queue in
643                  * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
644                  */
645                 if (waitqueue_active(&asoc->wait))
646                         wake_up_interruptible(&asoc->wait);
647
648                 /* Wake up any processes waiting in the sk's sleep queue of
649                  * a TCP-style or UDP-style peeled-off socket in
650                  * sctp_wait_for_accept() or sctp_wait_for_packet().
651                  * For a UDP-style socket, the waiters are woken up by the
652                  * notifications.
653                  */
654                 if (!sctp_style(sk, UDP))
655                         sk->sk_state_change(sk);
656         }
657 }
658
659 /* Helper function to delete an association. */
660 static void sctp_cmd_delete_tcb(sctp_cmd_seq_t *cmds,
661                                 struct sctp_association *asoc)
662 {
663         struct sock *sk = asoc->base.sk;
664
665         /* If it is a non-temporary association belonging to a TCP-style
666          * listening socket that is not closed, do not free it so that accept() 
667          * can pick it up later.
668          */ 
669         if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
670             (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
671                 return;
672
673         sctp_unhash_established(asoc);
674         sctp_association_free(asoc);
675 }
676
677 /*
678  * ADDIP Section 4.1 ASCONF Chunk Procedures
679  * A4) Start a T-4 RTO timer, using the RTO value of the selected
680  * destination address (we use active path instead of primary path just
681  * because primary path may be inactive. 
682  */
683 static void sctp_cmd_setup_t4(sctp_cmd_seq_t *cmds,
684                                 struct sctp_association *asoc,
685                                 struct sctp_chunk *chunk)
686 {
687         struct sctp_transport *t;
688
689         t = asoc->peer.active_path;
690         asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
691         chunk->transport = t;
692 }
693
694 /* Process an incoming Operation Error Chunk. */ 
695 static void sctp_cmd_process_operr(sctp_cmd_seq_t *cmds,
696                                    struct sctp_association *asoc,
697                                    struct sctp_chunk *chunk)
698 {
699         struct sctp_operr_chunk *operr_chunk;
700         struct sctp_errhdr *err_hdr;
701
702         operr_chunk = (struct sctp_operr_chunk *)chunk->chunk_hdr;
703         err_hdr = &operr_chunk->err_hdr;
704
705         switch (err_hdr->cause) {
706         case SCTP_ERROR_UNKNOWN_CHUNK:
707         {
708                 struct sctp_chunkhdr *unk_chunk_hdr;
709
710                 unk_chunk_hdr = (struct sctp_chunkhdr *)err_hdr->variable;
711                 switch (unk_chunk_hdr->type) {
712                 /* ADDIP 4.1 A9) If the peer responds to an ASCONF with an
713                  * ERROR chunk reporting that it did not recognized the ASCONF
714                  * chunk type, the sender of the ASCONF MUST NOT send any
715                  * further ASCONF chunks and MUST stop its T-4 timer.
716                  */
717                 case SCTP_CID_ASCONF:
718                         asoc->peer.asconf_capable = 0;
719                         sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
720                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
721                         break;
722                 default:
723                         break;
724                 }
725                 break;
726         }
727         default:
728                 break;
729         }
730 }
731
732 /* Process variable FWDTSN chunk information. */
733 static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq, 
734                                     struct sctp_chunk *chunk)
735 {
736         struct sctp_fwdtsn_skip *skip;
737         /* Walk through all the skipped SSNs */
738         sctp_walk_fwdtsn(skip, chunk) {
739                 sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
740         }
741
742         return;
743 }
744
745 /* These three macros allow us to pull the debugging code out of the
746  * main flow of sctp_do_sm() to keep attention focused on the real
747  * functionality there.
748  */
749 #define DEBUG_PRE \
750         SCTP_DEBUG_PRINTK("sctp_do_sm prefn: " \
751                           "ep %p, %s, %s, asoc %p[%s], %s\n", \
752                           ep, sctp_evttype_tbl[event_type], \
753                           (*debug_fn)(subtype), asoc, \
754                           sctp_state_tbl[state], state_fn->name)
755
756 #define DEBUG_POST \
757         SCTP_DEBUG_PRINTK("sctp_do_sm postfn: " \
758                           "asoc %p, status: %s\n", \
759                           asoc, sctp_status_tbl[status])
760
761 #define DEBUG_POST_SFX \
762         SCTP_DEBUG_PRINTK("sctp_do_sm post sfx: error %d, asoc %p[%s]\n", \
763                           error, asoc, \
764                           sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
765                           sctp_assoc2id(asoc)))?asoc->state:SCTP_STATE_CLOSED])
766
767 /*
768  * This is the master state machine processing function.
769  *
770  * If you want to understand all of lksctp, this is a
771  * good place to start.
772  */
773 int sctp_do_sm(sctp_event_t event_type, sctp_subtype_t subtype,
774                sctp_state_t state,
775                struct sctp_endpoint *ep,
776                struct sctp_association *asoc,
777                void *event_arg,
778                int gfp)
779 {
780         sctp_cmd_seq_t commands;
781         const sctp_sm_table_entry_t *state_fn;
782         sctp_disposition_t status;
783         int error = 0;
784         typedef const char *(printfn_t)(sctp_subtype_t);
785
786         static printfn_t *table[] = {
787                 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
788         };
789         printfn_t *debug_fn  __attribute__ ((unused)) = table[event_type];
790
791         /* Look up the state function, run it, and then process the
792          * side effects.  These three steps are the heart of lksctp.
793          */
794         state_fn = sctp_sm_lookup_event(event_type, state, subtype);
795
796         sctp_init_cmd_seq(&commands);
797
798         DEBUG_PRE;
799         status = (*state_fn->fn)(ep, asoc, subtype, event_arg, &commands);
800         DEBUG_POST;
801
802         error = sctp_side_effects(event_type, subtype, state,
803                                   ep, asoc, event_arg, status, 
804                                   &commands, gfp);
805         DEBUG_POST_SFX;
806
807         return error;
808 }
809
810 #undef DEBUG_PRE
811 #undef DEBUG_POST
812
813 /*****************************************************************
814  * This the master state function side effect processing function.
815  *****************************************************************/
816 int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
817                       sctp_state_t state,
818                       struct sctp_endpoint *ep,
819                       struct sctp_association *asoc,
820                       void *event_arg,
821                       sctp_disposition_t status,
822                       sctp_cmd_seq_t *commands,
823                       int gfp)
824 {
825         int error;
826
827         /* FIXME - Most of the dispositions left today would be categorized
828          * as "exceptional" dispositions.  For those dispositions, it
829          * may not be proper to run through any of the commands at all.
830          * For example, the command interpreter might be run only with
831          * disposition SCTP_DISPOSITION_CONSUME.
832          */
833         if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
834                                                ep, asoc,
835                                                event_arg, status,
836                                                commands, gfp)))
837                 goto bail;
838
839         switch (status) {
840         case SCTP_DISPOSITION_DISCARD:
841                 SCTP_DEBUG_PRINTK("Ignored sctp protocol event - state %d, "
842                                   "event_type %d, event_id %d\n",
843                                   state, event_type, subtype.chunk);
844                 break;
845
846         case SCTP_DISPOSITION_NOMEM:
847                 /* We ran out of memory, so we need to discard this
848                  * packet.
849                  */
850                 /* BUG--we should now recover some memory, probably by
851                  * reneging...
852                  */
853                 error = -ENOMEM;
854                 break;
855
856         case SCTP_DISPOSITION_DELETE_TCB:
857                 /* This should now be a command. */
858                 break;
859
860         case SCTP_DISPOSITION_CONSUME:
861         case SCTP_DISPOSITION_ABORT:
862                 /*
863                  * We should no longer have much work to do here as the
864                  * real work has been done as explicit commands above.
865                  */
866                 break;
867
868         case SCTP_DISPOSITION_VIOLATION:
869                 printk(KERN_ERR "sctp protocol violation state %d "
870                        "chunkid %d\n", state, subtype.chunk);
871                 break;
872
873         case SCTP_DISPOSITION_NOT_IMPL:
874                 printk(KERN_WARNING "sctp unimplemented feature in state %d, "
875                        "event_type %d, event_id %d\n",
876                        state, event_type, subtype.chunk);
877                 break;
878
879         case SCTP_DISPOSITION_BUG:
880                 printk(KERN_ERR "sctp bug in state %d, "
881                        "event_type %d, event_id %d\n",
882                        state, event_type, subtype.chunk);
883                 BUG();
884                 break;
885
886         default:
887                 printk(KERN_ERR "sctp impossible disposition %d "
888                        "in state %d, event_type %d, event_id %d\n",
889                        status, state, event_type, subtype.chunk);
890                 BUG();
891                 break;
892         };
893
894 bail:
895         return error;
896 }
897
898 /********************************************************************
899  * 2nd Level Abstractions
900  ********************************************************************/
901
902 /* This is the side-effect interpreter.  */
903 int sctp_cmd_interpreter(sctp_event_t event_type, sctp_subtype_t subtype,
904                          sctp_state_t state, struct sctp_endpoint *ep,
905                          struct sctp_association *asoc, void *event_arg,
906                          sctp_disposition_t status, sctp_cmd_seq_t *commands,
907                          int gfp)
908 {
909         int error = 0;
910         int force;
911         sctp_cmd_t *cmd;
912         struct sctp_chunk *new_obj;
913         struct sctp_chunk *chunk = NULL;
914         struct sctp_packet *packet;
915         struct list_head *pos;
916         struct timer_list *timer;
917         unsigned long timeout;
918         struct sctp_transport *t;
919         struct sctp_sackhdr sackh;
920         int local_cork = 0;
921
922         if (SCTP_EVENT_T_TIMEOUT != event_type)
923                 chunk = (struct sctp_chunk *) event_arg;
924
925         /* Note:  This whole file is a huge candidate for rework.
926          * For example, each command could either have its own handler, so
927          * the loop would look like:
928          *     while (cmds)
929          *         cmd->handle(x, y, z)
930          * --jgrimm
931          */
932         while (NULL != (cmd = sctp_next_cmd(commands))) {
933                 switch (cmd->verb) {
934                 case SCTP_CMD_NOP:
935                         /* Do nothing. */
936                         break;
937
938                 case SCTP_CMD_NEW_ASOC:
939                         /* Register a new association.  */
940                         if (local_cork) {
941                                 sctp_outq_uncork(&asoc->outqueue); 
942                                 local_cork = 0;
943                         }
944                         asoc = cmd->obj.ptr;
945                         /* Register with the endpoint.  */
946                         sctp_endpoint_add_asoc(ep, asoc);
947                         sctp_hash_established(asoc);
948                         break;
949
950                 case SCTP_CMD_UPDATE_ASSOC:
951                        sctp_assoc_update(asoc, cmd->obj.ptr);
952                        break;
953
954                 case SCTP_CMD_PURGE_OUTQUEUE:
955                        sctp_outq_teardown(&asoc->outqueue);
956                        break;
957
958                 case SCTP_CMD_DELETE_TCB:                       
959                         if (local_cork) {
960                                 sctp_outq_uncork(&asoc->outqueue);
961                                 local_cork = 0;
962                         }
963                         /* Delete the current association.  */
964                         sctp_cmd_delete_tcb(commands, asoc);
965                         asoc = NULL;
966                         break;
967
968                 case SCTP_CMD_NEW_STATE:
969                         /* Enter a new state.  */
970                         sctp_cmd_new_state(commands, asoc, cmd->obj.state);
971                         break;
972
973                 case SCTP_CMD_REPORT_TSN:
974                         /* Record the arrival of a TSN.  */
975                         sctp_tsnmap_mark(&asoc->peer.tsn_map, cmd->obj.u32);
976                         break;
977
978                 case SCTP_CMD_REPORT_FWDTSN:
979                         /* Move the Cumulattive TSN Ack ahead. */
980                         sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32);
981
982                         /* Abort any in progress partial delivery. */
983                         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
984                         break;
985
986                 case SCTP_CMD_PROCESS_FWDTSN:
987                         sctp_cmd_process_fwdtsn(&asoc->ulpq, cmd->obj.ptr);
988                         break;
989
990                 case SCTP_CMD_GEN_SACK:
991                         /* Generate a Selective ACK.
992                          * The argument tells us whether to just count
993                          * the packet and MAYBE generate a SACK, or
994                          * force a SACK out.
995                          */
996                         force = cmd->obj.i32;
997                         error = sctp_gen_sack(asoc, force, commands);
998                         break;
999
1000                 case SCTP_CMD_PROCESS_SACK:
1001                         /* Process an inbound SACK.  */
1002                         error = sctp_cmd_process_sack(commands, asoc,
1003                                                       cmd->obj.ptr);
1004                         break;
1005
1006                 case SCTP_CMD_GEN_INIT_ACK:
1007                         /* Generate an INIT ACK chunk.  */
1008                         new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1009                                                      0);
1010                         if (!new_obj)
1011                                 goto nomem;
1012
1013                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1014                                         SCTP_CHUNK(new_obj));
1015                         break;
1016
1017                 case SCTP_CMD_PEER_INIT:
1018                         /* Process a unified INIT from the peer.
1019                          * Note: Only used during INIT-ACK processing.  If
1020                          * there is an error just return to the outter
1021                          * layer which will bail.
1022                          */
1023                         error = sctp_cmd_process_init(commands, asoc, chunk,
1024                                                       cmd->obj.ptr, gfp);
1025                         break;
1026
1027                 case SCTP_CMD_GEN_COOKIE_ECHO:
1028                         /* Generate a COOKIE ECHO chunk.  */
1029                         new_obj = sctp_make_cookie_echo(asoc, chunk);
1030                         if (!new_obj) {
1031                                 if (cmd->obj.ptr)
1032                                         sctp_chunk_free(cmd->obj.ptr);
1033                                 goto nomem;
1034                         }
1035                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1036                                         SCTP_CHUNK(new_obj));
1037
1038                         /* If there is an ERROR chunk to be sent along with
1039                          * the COOKIE_ECHO, send it, too.
1040                          */
1041                         if (cmd->obj.ptr)
1042                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1043                                                 SCTP_CHUNK(cmd->obj.ptr));
1044                         break;
1045
1046                 case SCTP_CMD_GEN_SHUTDOWN:
1047                         /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1048                          * Reset error counts.
1049                          */
1050                         asoc->overall_error_count = 0;
1051
1052                         /* Generate a SHUTDOWN chunk.  */
1053                         new_obj = sctp_make_shutdown(asoc, chunk);
1054                         if (!new_obj)
1055                                 goto nomem;
1056                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1057                                         SCTP_CHUNK(new_obj));
1058                         break;
1059
1060                 case SCTP_CMD_CHUNK_ULP:
1061                         /* Send a chunk to the sockets layer.  */
1062                         SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1063                                           "chunk_up:", cmd->obj.ptr,
1064                                           "ulpq:", &asoc->ulpq);
1065                         sctp_ulpq_tail_data(&asoc->ulpq, cmd->obj.ptr,
1066                                             GFP_ATOMIC);
1067                         break;
1068
1069                 case SCTP_CMD_EVENT_ULP:
1070                         /* Send a notification to the sockets layer.  */
1071                         SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1072                                           "event_up:",cmd->obj.ptr,
1073                                           "ulpq:",&asoc->ulpq);
1074                         sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ptr);
1075                         break;
1076
1077                 case SCTP_CMD_REPLY:
1078                         /* If an caller has not already corked, do cork. */
1079                         if (!asoc->outqueue.cork) {
1080                                 sctp_outq_cork(&asoc->outqueue);
1081                                 local_cork = 1;
1082                         }
1083                         /* Send a chunk to our peer.  */
1084                         error = sctp_outq_tail(&asoc->outqueue, cmd->obj.ptr);
1085                         break;
1086
1087                 case SCTP_CMD_SEND_PKT:
1088                         /* Send a full packet to our peer.  */
1089                         packet = cmd->obj.ptr;
1090                         sctp_packet_transmit(packet);
1091                         sctp_ootb_pkt_free(packet);
1092                         break;
1093
1094                 case SCTP_CMD_RETRAN:
1095                         /* Mark a transport for retransmission.  */
1096                         sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1097                                         SCTP_RTXR_T3_RTX);
1098                         break;
1099
1100                 case SCTP_CMD_TRANSMIT:
1101                         /* Kick start transmission. */
1102                         error = sctp_outq_uncork(&asoc->outqueue);
1103                         local_cork = 0;
1104                         break;
1105
1106                 case SCTP_CMD_ECN_CE:
1107                         /* Do delayed CE processing.   */
1108                         sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1109                         break;
1110
1111                 case SCTP_CMD_ECN_ECNE:
1112                         /* Do delayed ECNE processing. */
1113                         new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1114                                                         chunk);
1115                         if (new_obj)
1116                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1117                                                 SCTP_CHUNK(new_obj));
1118                         break;
1119
1120                 case SCTP_CMD_ECN_CWR:
1121                         /* Do delayed CWR processing.  */
1122                         sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1123                         break;
1124
1125                 case SCTP_CMD_SETUP_T2:
1126                         sctp_cmd_setup_t2(commands, asoc, cmd->obj.ptr);
1127                         break;
1128
1129                 case SCTP_CMD_TIMER_START:
1130                         timer = &asoc->timers[cmd->obj.to];
1131                         timeout = asoc->timeouts[cmd->obj.to];
1132                         if (!timeout)
1133                                 BUG();
1134
1135                         timer->expires = jiffies + timeout;
1136                         sctp_association_hold(asoc);
1137                         add_timer(timer);
1138                         break;
1139
1140                 case SCTP_CMD_TIMER_RESTART:
1141                         timer = &asoc->timers[cmd->obj.to];
1142                         timeout = asoc->timeouts[cmd->obj.to];
1143                         if (!mod_timer(timer, jiffies + timeout))
1144                                 sctp_association_hold(asoc);
1145                         break;
1146
1147                 case SCTP_CMD_TIMER_STOP:
1148                         timer = &asoc->timers[cmd->obj.to];
1149                         if (timer_pending(timer) && del_timer(timer))
1150                                 sctp_association_put(asoc);
1151                         break;
1152
1153                 case SCTP_CMD_INIT_RESTART:
1154                         /* Do the needed accounting and updates
1155                          * associated with restarting an initialization
1156                          * timer.
1157                          */
1158                         asoc->counters[SCTP_COUNTER_INIT_ERROR]++;
1159                         asoc->timeouts[cmd->obj.to] *= 2;
1160                         if (asoc->timeouts[cmd->obj.to] >
1161                             asoc->max_init_timeo) {
1162                                 asoc->timeouts[cmd->obj.to] =
1163                                         asoc->max_init_timeo;
1164                         }
1165
1166                         /* If we've sent any data bundled with
1167                          * COOKIE-ECHO we need to resend.
1168                          */
1169                         list_for_each(pos, &asoc->peer.transport_addr_list) {
1170                                 t = list_entry(pos, struct sctp_transport,
1171                                                transports);
1172                                 sctp_retransmit_mark(&asoc->outqueue, t, 0);
1173                         }
1174
1175                         sctp_add_cmd_sf(commands,
1176                                         SCTP_CMD_TIMER_RESTART,
1177                                         SCTP_TO(cmd->obj.to));
1178                         break;
1179
1180                 case SCTP_CMD_INIT_FAILED:
1181                         sctp_cmd_init_failed(commands, asoc, cmd->obj.u32);
1182                         break;
1183
1184                 case SCTP_CMD_ASSOC_FAILED:
1185                         sctp_cmd_assoc_failed(commands, asoc, event_type,
1186                                               subtype, chunk, cmd->obj.u32);
1187                         break;
1188
1189                 case SCTP_CMD_COUNTER_INC:
1190                         asoc->counters[cmd->obj.counter]++;
1191                         break;
1192
1193                 case SCTP_CMD_COUNTER_RESET:
1194                         asoc->counters[cmd->obj.counter] = 0;
1195                         break;
1196
1197                 case SCTP_CMD_REPORT_DUP:
1198                         sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1199                                              cmd->obj.u32);
1200                         break;
1201
1202                 case SCTP_CMD_REPORT_BAD_TAG:
1203                         SCTP_DEBUG_PRINTK("vtag mismatch!\n");
1204                         break;
1205
1206                 case SCTP_CMD_STRIKE:
1207                         /* Mark one strike against a transport.  */
1208                         sctp_do_8_2_transport_strike(asoc, cmd->obj.transport);
1209                         break;
1210
1211                 case SCTP_CMD_TRANSPORT_RESET:
1212                         t = cmd->obj.transport;
1213                         sctp_cmd_transport_reset(commands, asoc, t);
1214                         break;
1215
1216                 case SCTP_CMD_TRANSPORT_ON:
1217                         t = cmd->obj.transport;
1218                         sctp_cmd_transport_on(commands, asoc, t, chunk);
1219                         break;
1220
1221                 case SCTP_CMD_HB_TIMERS_START:
1222                         sctp_cmd_hb_timers_start(commands, asoc);
1223                         break;
1224
1225                 case SCTP_CMD_HB_TIMER_UPDATE:
1226                         t = cmd->obj.transport;
1227                         sctp_cmd_hb_timer_update(commands, asoc, t);
1228                         break;
1229
1230                 case SCTP_CMD_HB_TIMERS_STOP:
1231                         sctp_cmd_hb_timers_stop(commands, asoc);
1232                         break;
1233
1234                 case SCTP_CMD_REPORT_ERROR:
1235                         error = cmd->obj.error;
1236                         break;
1237
1238                 case SCTP_CMD_PROCESS_CTSN:
1239                         /* Dummy up a SACK for processing. */
1240                         sackh.cum_tsn_ack = cmd->obj.u32;
1241                         sackh.a_rwnd = 0;
1242                         sackh.num_gap_ack_blocks = 0;
1243                         sackh.num_dup_tsns = 0;
1244                         sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1245                                         SCTP_SACKH(&sackh));
1246                         break;
1247
1248                 case SCTP_CMD_DISCARD_PACKET:
1249                         /* We need to discard the whole packet.  */
1250                         chunk->pdiscard = 1;
1251                         break;
1252
1253                 case SCTP_CMD_RTO_PENDING:
1254                         t = cmd->obj.transport;
1255                         t->rto_pending = 1;
1256                         break;
1257
1258                 case SCTP_CMD_PART_DELIVER:
1259                         sctp_ulpq_partial_delivery(&asoc->ulpq, cmd->obj.ptr,
1260                                                    GFP_ATOMIC);
1261                         break;
1262
1263                 case SCTP_CMD_RENEGE:
1264                         sctp_ulpq_renege(&asoc->ulpq, cmd->obj.ptr,
1265                                          GFP_ATOMIC);
1266                         break;
1267
1268                 case SCTP_CMD_SETUP_T4:
1269                         sctp_cmd_setup_t4(commands, asoc, cmd->obj.ptr);
1270                         break;
1271
1272                 case SCTP_CMD_PROCESS_OPERR:
1273                         sctp_cmd_process_operr(commands, asoc, chunk);
1274                         break;
1275                 default:
1276                         printk(KERN_WARNING "Impossible command: %u, %p\n",
1277                                cmd->verb, cmd->obj.ptr);
1278                         break;
1279                 };
1280                 if (error)
1281                         break;
1282         }
1283
1284 out:
1285         if (local_cork)
1286                 sctp_outq_uncork(&asoc->outqueue);
1287         return error;
1288 nomem:
1289         error = -ENOMEM;
1290         goto out;
1291 }
1292