Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
[linux-2.6.git] / net / sctp / sm_sideeffect.c
1 /* SCTP kernel 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 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  * This SCTP 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  * This SCTP 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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
51
52 #include <linux/skbuff.h>
53 #include <linux/types.h>
54 #include <linux/socket.h>
55 #include <linux/ip.h>
56 #include <linux/gfp.h>
57 #include <net/sock.h>
58 #include <net/sctp/sctp.h>
59 #include <net/sctp/sm.h>
60
61 static int sctp_cmd_interpreter(sctp_event_t event_type,
62                                 sctp_subtype_t subtype,
63                                 sctp_state_t state,
64                                 struct sctp_endpoint *ep,
65                                 struct sctp_association *asoc,
66                                 void *event_arg,
67                                 sctp_disposition_t status,
68                                 sctp_cmd_seq_t *commands,
69                                 gfp_t gfp);
70 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
71                              sctp_state_t state,
72                              struct sctp_endpoint *ep,
73                              struct sctp_association *asoc,
74                              void *event_arg,
75                              sctp_disposition_t status,
76                              sctp_cmd_seq_t *commands,
77                              gfp_t gfp);
78
79 /********************************************************************
80  * Helper functions
81  ********************************************************************/
82
83 /* A helper function for delayed processing of INET ECN CE bit. */
84 static void sctp_do_ecn_ce_work(struct sctp_association *asoc,
85                                 __u32 lowest_tsn)
86 {
87         /* Save the TSN away for comparison when we receive CWR */
88
89         asoc->last_ecne_tsn = lowest_tsn;
90         asoc->need_ecne = 1;
91 }
92
93 /* Helper function for delayed processing of SCTP ECNE chunk.  */
94 /* RFC 2960 Appendix A
95  *
96  * RFC 2481 details a specific bit for a sender to send in
97  * the header of its next outbound TCP segment to indicate to
98  * its peer that it has reduced its congestion window.  This
99  * is termed the CWR bit.  For SCTP the same indication is made
100  * by including the CWR chunk.  This chunk contains one data
101  * element, i.e. the TSN number that was sent in the ECNE chunk.
102  * This element represents the lowest TSN number in the datagram
103  * that was originally marked with the CE bit.
104  */
105 static struct sctp_chunk *sctp_do_ecn_ecne_work(struct sctp_association *asoc,
106                                            __u32 lowest_tsn,
107                                            struct sctp_chunk *chunk)
108 {
109         struct sctp_chunk *repl;
110
111         /* Our previously transmitted packet ran into some congestion
112          * so we should take action by reducing cwnd and ssthresh
113          * and then ACK our peer that we we've done so by
114          * sending a CWR.
115          */
116
117         /* First, try to determine if we want to actually lower
118          * our cwnd variables.  Only lower them if the ECNE looks more
119          * recent than the last response.
120          */
121         if (TSN_lt(asoc->last_cwr_tsn, lowest_tsn)) {
122                 struct sctp_transport *transport;
123
124                 /* Find which transport's congestion variables
125                  * need to be adjusted.
126                  */
127                 transport = sctp_assoc_lookup_tsn(asoc, lowest_tsn);
128
129                 /* Update the congestion variables. */
130                 if (transport)
131                         sctp_transport_lower_cwnd(transport,
132                                                   SCTP_LOWER_CWND_ECNE);
133                 asoc->last_cwr_tsn = lowest_tsn;
134         }
135
136         /* Always try to quiet the other end.  In case of lost CWR,
137          * resend last_cwr_tsn.
138          */
139         repl = sctp_make_cwr(asoc, asoc->last_cwr_tsn, chunk);
140
141         /* If we run out of memory, it will look like a lost CWR.  We'll
142          * get back in sync eventually.
143          */
144         return repl;
145 }
146
147 /* Helper function to do delayed processing of ECN CWR chunk.  */
148 static void sctp_do_ecn_cwr_work(struct sctp_association *asoc,
149                                  __u32 lowest_tsn)
150 {
151         /* Turn off ECNE getting auto-prepended to every outgoing
152          * packet
153          */
154         asoc->need_ecne = 0;
155 }
156
157 /* Generate SACK if necessary.  We call this at the end of a packet.  */
158 static int sctp_gen_sack(struct sctp_association *asoc, int force,
159                          sctp_cmd_seq_t *commands)
160 {
161         __u32 ctsn, max_tsn_seen;
162         struct sctp_chunk *sack;
163         struct sctp_transport *trans = asoc->peer.last_data_from;
164         int error = 0;
165
166         if (force ||
167             (!trans && (asoc->param_flags & SPP_SACKDELAY_DISABLE)) ||
168             (trans && (trans->param_flags & SPP_SACKDELAY_DISABLE)))
169                 asoc->peer.sack_needed = 1;
170
171         ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
172         max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
173
174         /* From 12.2 Parameters necessary per association (i.e. the TCB):
175          *
176          * Ack State : This flag indicates if the next received packet
177          *           : is to be responded to with a SACK. ...
178          *           : When DATA chunks are out of order, SACK's
179          *           : are not delayed (see Section 6).
180          *
181          * [This is actually not mentioned in Section 6, but we
182          * implement it here anyway. --piggy]
183          */
184         if (max_tsn_seen != ctsn)
185                 asoc->peer.sack_needed = 1;
186
187         /* From 6.2  Acknowledgement on Reception of DATA Chunks:
188          *
189          * Section 4.2 of [RFC2581] SHOULD be followed. Specifically,
190          * an acknowledgement SHOULD be generated for at least every
191          * second packet (not every second DATA chunk) received, and
192          * SHOULD be generated within 200 ms of the arrival of any
193          * unacknowledged DATA chunk. ...
194          */
195         if (!asoc->peer.sack_needed) {
196                 asoc->peer.sack_cnt++;
197
198                 /* Set the SACK delay timeout based on the
199                  * SACK delay for the last transport
200                  * data was received from, or the default
201                  * for the association.
202                  */
203                 if (trans) {
204                         /* We will need a SACK for the next packet.  */
205                         if (asoc->peer.sack_cnt >= trans->sackfreq - 1)
206                                 asoc->peer.sack_needed = 1;
207
208                         asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
209                                 trans->sackdelay;
210                 } else {
211                         /* We will need a SACK for the next packet.  */
212                         if (asoc->peer.sack_cnt >= asoc->sackfreq - 1)
213                                 asoc->peer.sack_needed = 1;
214
215                         asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
216                                 asoc->sackdelay;
217                 }
218
219                 /* Restart the SACK timer. */
220                 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
221                                 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
222         } else {
223                 asoc->a_rwnd = asoc->rwnd;
224                 sack = sctp_make_sack(asoc);
225                 if (!sack)
226                         goto nomem;
227
228                 asoc->peer.sack_needed = 0;
229                 asoc->peer.sack_cnt = 0;
230
231                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(sack));
232
233                 /* Stop the SACK timer.  */
234                 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
235                                 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
236         }
237
238         return error;
239 nomem:
240         error = -ENOMEM;
241         return error;
242 }
243
244 /* When the T3-RTX timer expires, it calls this function to create the
245  * relevant state machine event.
246  */
247 void sctp_generate_t3_rtx_event(unsigned long peer)
248 {
249         int error;
250         struct sctp_transport *transport = (struct sctp_transport *) peer;
251         struct sctp_association *asoc = transport->asoc;
252
253         /* Check whether a task is in the sock.  */
254
255         sctp_bh_lock_sock(asoc->base.sk);
256         if (sock_owned_by_user(asoc->base.sk)) {
257                 SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __func__);
258
259                 /* Try again later.  */
260                 if (!mod_timer(&transport->T3_rtx_timer, jiffies + (HZ/20)))
261                         sctp_transport_hold(transport);
262                 goto out_unlock;
263         }
264
265         /* Is this transport really dead and just waiting around for
266          * the timer to let go of the reference?
267          */
268         if (transport->dead)
269                 goto out_unlock;
270
271         /* Run through the state machine.  */
272         error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
273                            SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX),
274                            asoc->state,
275                            asoc->ep, asoc,
276                            transport, GFP_ATOMIC);
277
278         if (error)
279                 asoc->base.sk->sk_err = -error;
280
281 out_unlock:
282         sctp_bh_unlock_sock(asoc->base.sk);
283         sctp_transport_put(transport);
284 }
285
286 /* This is a sa interface for producing timeout events.  It works
287  * for timeouts which use the association as their parameter.
288  */
289 static void sctp_generate_timeout_event(struct sctp_association *asoc,
290                                         sctp_event_timeout_t timeout_type)
291 {
292         int error = 0;
293
294         sctp_bh_lock_sock(asoc->base.sk);
295         if (sock_owned_by_user(asoc->base.sk)) {
296                 SCTP_DEBUG_PRINTK("%s:Sock is busy: timer %d\n",
297                                   __func__,
298                                   timeout_type);
299
300                 /* Try again later.  */
301                 if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20)))
302                         sctp_association_hold(asoc);
303                 goto out_unlock;
304         }
305
306         /* Is this association really dead and just waiting around for
307          * the timer to let go of the reference?
308          */
309         if (asoc->base.dead)
310                 goto out_unlock;
311
312         /* Run through the state machine.  */
313         error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
314                            SCTP_ST_TIMEOUT(timeout_type),
315                            asoc->state, asoc->ep, asoc,
316                            (void *)timeout_type, GFP_ATOMIC);
317
318         if (error)
319                 asoc->base.sk->sk_err = -error;
320
321 out_unlock:
322         sctp_bh_unlock_sock(asoc->base.sk);
323         sctp_association_put(asoc);
324 }
325
326 static void sctp_generate_t1_cookie_event(unsigned long data)
327 {
328         struct sctp_association *asoc = (struct sctp_association *) data;
329         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
330 }
331
332 static void sctp_generate_t1_init_event(unsigned long data)
333 {
334         struct sctp_association *asoc = (struct sctp_association *) data;
335         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
336 }
337
338 static void sctp_generate_t2_shutdown_event(unsigned long data)
339 {
340         struct sctp_association *asoc = (struct sctp_association *) data;
341         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
342 }
343
344 static void sctp_generate_t4_rto_event(unsigned long data)
345 {
346         struct sctp_association *asoc = (struct sctp_association *) data;
347         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
348 }
349
350 static void sctp_generate_t5_shutdown_guard_event(unsigned long data)
351 {
352         struct sctp_association *asoc = (struct sctp_association *)data;
353         sctp_generate_timeout_event(asoc,
354                                     SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);
355
356 } /* sctp_generate_t5_shutdown_guard_event() */
357
358 static void sctp_generate_autoclose_event(unsigned long data)
359 {
360         struct sctp_association *asoc = (struct sctp_association *) data;
361         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE);
362 }
363
364 /* Generate a heart beat event.  If the sock is busy, reschedule.   Make
365  * sure that the transport is still valid.
366  */
367 void sctp_generate_heartbeat_event(unsigned long data)
368 {
369         int error = 0;
370         struct sctp_transport *transport = (struct sctp_transport *) data;
371         struct sctp_association *asoc = transport->asoc;
372
373         sctp_bh_lock_sock(asoc->base.sk);
374         if (sock_owned_by_user(asoc->base.sk)) {
375                 SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __func__);
376
377                 /* Try again later.  */
378                 if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20)))
379                         sctp_transport_hold(transport);
380                 goto out_unlock;
381         }
382
383         /* Is this structure just waiting around for us to actually
384          * get destroyed?
385          */
386         if (transport->dead)
387                 goto out_unlock;
388
389         error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
390                            SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
391                            asoc->state, asoc->ep, asoc,
392                            transport, GFP_ATOMIC);
393
394          if (error)
395                  asoc->base.sk->sk_err = -error;
396
397 out_unlock:
398         sctp_bh_unlock_sock(asoc->base.sk);
399         sctp_transport_put(transport);
400 }
401
402 /* Handle the timeout of the ICMP protocol unreachable timer.  Trigger
403  * the correct state machine transition that will close the association.
404  */
405 void sctp_generate_proto_unreach_event(unsigned long data)
406 {
407         struct sctp_transport *transport = (struct sctp_transport *) data;
408         struct sctp_association *asoc = transport->asoc;
409         
410         sctp_bh_lock_sock(asoc->base.sk);
411         if (sock_owned_by_user(asoc->base.sk)) {
412                 SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __func__);
413
414                 /* Try again later.  */
415                 if (!mod_timer(&transport->proto_unreach_timer,
416                                 jiffies + (HZ/20)))
417                         sctp_association_hold(asoc);
418                 goto out_unlock;
419         }
420
421         /* Is this structure just waiting around for us to actually
422          * get destroyed?
423          */
424         if (asoc->base.dead)
425                 goto out_unlock;
426
427         sctp_do_sm(SCTP_EVENT_T_OTHER,
428                    SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH),
429                    asoc->state, asoc->ep, asoc, transport, GFP_ATOMIC);
430
431 out_unlock:
432         sctp_bh_unlock_sock(asoc->base.sk);
433         sctp_association_put(asoc);
434 }
435
436
437 /* Inject a SACK Timeout event into the state machine.  */
438 static void sctp_generate_sack_event(unsigned long data)
439 {
440         struct sctp_association *asoc = (struct sctp_association *) data;
441         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
442 }
443
444 sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
445         NULL,
446         sctp_generate_t1_cookie_event,
447         sctp_generate_t1_init_event,
448         sctp_generate_t2_shutdown_event,
449         NULL,
450         sctp_generate_t4_rto_event,
451         sctp_generate_t5_shutdown_guard_event,
452         NULL,
453         sctp_generate_sack_event,
454         sctp_generate_autoclose_event,
455 };
456
457
458 /* RFC 2960 8.2 Path Failure Detection
459  *
460  * When its peer endpoint is multi-homed, an endpoint should keep a
461  * error counter for each of the destination transport addresses of the
462  * peer endpoint.
463  *
464  * Each time the T3-rtx timer expires on any address, or when a
465  * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
466  * the error counter of that destination address will be incremented.
467  * When the value in the error counter exceeds the protocol parameter
468  * 'Path.Max.Retrans' of that destination address, the endpoint should
469  * mark the destination transport address as inactive, and a
470  * notification SHOULD be sent to the upper layer.
471  *
472  */
473 static void sctp_do_8_2_transport_strike(struct sctp_association *asoc,
474                                          struct sctp_transport *transport,
475                                          int is_hb)
476 {
477         /* The check for association's overall error counter exceeding the
478          * threshold is done in the state function.
479          */
480         /* We are here due to a timer expiration.  If the timer was
481          * not a HEARTBEAT, then normal error tracking is done.
482          * If the timer was a heartbeat, we only increment error counts
483          * when we already have an outstanding HEARTBEAT that has not
484          * been acknowledged.
485          * Additionally, some tranport states inhibit error increments.
486          */
487         if (!is_hb) {
488                 asoc->overall_error_count++;
489                 if (transport->state != SCTP_INACTIVE)
490                         transport->error_count++;
491          } else if (transport->hb_sent) {
492                 if (transport->state != SCTP_UNCONFIRMED)
493                         asoc->overall_error_count++;
494                 if (transport->state != SCTP_INACTIVE)
495                         transport->error_count++;
496         }
497
498         if (transport->state != SCTP_INACTIVE &&
499             (transport->error_count > transport->pathmaxrxt)) {
500                 SCTP_DEBUG_PRINTK_IPADDR("transport_strike:association %p",
501                                          " transport IP: port:%d failed.\n",
502                                          asoc,
503                                          (&transport->ipaddr),
504                                          ntohs(transport->ipaddr.v4.sin_port));
505                 sctp_assoc_control_transport(asoc, transport,
506                                              SCTP_TRANSPORT_DOWN,
507                                              SCTP_FAILED_THRESHOLD);
508         }
509
510         /* E2) For the destination address for which the timer
511          * expires, set RTO <- RTO * 2 ("back off the timer").  The
512          * maximum value discussed in rule C7 above (RTO.max) may be
513          * used to provide an upper bound to this doubling operation.
514          *
515          * Special Case:  the first HB doesn't trigger exponential backoff.
516          * The first unacknowledged HB triggers it.  We do this with a flag
517          * that indicates that we have an outstanding HB.
518          */
519         if (!is_hb || transport->hb_sent) {
520                 transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
521         }
522 }
523
524 /* Worker routine to handle INIT command failure.  */
525 static void sctp_cmd_init_failed(sctp_cmd_seq_t *commands,
526                                  struct sctp_association *asoc,
527                                  unsigned error)
528 {
529         struct sctp_ulpevent *event;
530
531         event = sctp_ulpevent_make_assoc_change(asoc,0, SCTP_CANT_STR_ASSOC,
532                                                 (__u16)error, 0, 0, NULL,
533                                                 GFP_ATOMIC);
534
535         if (event)
536                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
537                                 SCTP_ULPEVENT(event));
538
539         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
540                         SCTP_STATE(SCTP_STATE_CLOSED));
541
542         /* SEND_FAILED sent later when cleaning up the association. */
543         asoc->outqueue.error = error;
544         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
545 }
546
547 /* Worker routine to handle SCTP_CMD_ASSOC_FAILED.  */
548 static void sctp_cmd_assoc_failed(sctp_cmd_seq_t *commands,
549                                   struct sctp_association *asoc,
550                                   sctp_event_t event_type,
551                                   sctp_subtype_t subtype,
552                                   struct sctp_chunk *chunk,
553                                   unsigned error)
554 {
555         struct sctp_ulpevent *event;
556
557         /* Cancel any partial delivery in progress. */
558         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
559
560         if (event_type == SCTP_EVENT_T_CHUNK && subtype.chunk == SCTP_CID_ABORT)
561                 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
562                                                 (__u16)error, 0, 0, chunk,
563                                                 GFP_ATOMIC);
564         else
565                 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
566                                                 (__u16)error, 0, 0, NULL,
567                                                 GFP_ATOMIC);
568         if (event)
569                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
570                                 SCTP_ULPEVENT(event));
571
572         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
573                         SCTP_STATE(SCTP_STATE_CLOSED));
574
575         /* SEND_FAILED sent later when cleaning up the association. */
576         asoc->outqueue.error = error;
577         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
578 }
579
580 /* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
581  * inside the cookie.  In reality, this is only used for INIT-ACK processing
582  * since all other cases use "temporary" associations and can do all
583  * their work in statefuns directly.
584  */
585 static int sctp_cmd_process_init(sctp_cmd_seq_t *commands,
586                                  struct sctp_association *asoc,
587                                  struct sctp_chunk *chunk,
588                                  sctp_init_chunk_t *peer_init,
589                                  gfp_t gfp)
590 {
591         int error;
592
593         /* We only process the init as a sideeffect in a single
594          * case.   This is when we process the INIT-ACK.   If we
595          * fail during INIT processing (due to malloc problems),
596          * just return the error and stop processing the stack.
597          */
598         if (!sctp_process_init(asoc, chunk, sctp_source(chunk), peer_init, gfp))
599                 error = -ENOMEM;
600         else
601                 error = 0;
602
603         return error;
604 }
605
606 /* Helper function to break out starting up of heartbeat timers.  */
607 static void sctp_cmd_hb_timers_start(sctp_cmd_seq_t *cmds,
608                                      struct sctp_association *asoc)
609 {
610         struct sctp_transport *t;
611
612         /* Start a heartbeat timer for each transport on the association.
613          * hold a reference on the transport to make sure none of
614          * the needed data structures go away.
615          */
616         list_for_each_entry(t, &asoc->peer.transport_addr_list, transports) {
617
618                 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
619                         sctp_transport_hold(t);
620         }
621 }
622
623 static void sctp_cmd_hb_timers_stop(sctp_cmd_seq_t *cmds,
624                                     struct sctp_association *asoc)
625 {
626         struct sctp_transport *t;
627
628         /* Stop all heartbeat timers. */
629
630         list_for_each_entry(t, &asoc->peer.transport_addr_list,
631                         transports) {
632                 if (del_timer(&t->hb_timer))
633                         sctp_transport_put(t);
634         }
635 }
636
637 /* Helper function to stop any pending T3-RTX timers */
638 static void sctp_cmd_t3_rtx_timers_stop(sctp_cmd_seq_t *cmds,
639                                         struct sctp_association *asoc)
640 {
641         struct sctp_transport *t;
642
643         list_for_each_entry(t, &asoc->peer.transport_addr_list,
644                         transports) {
645                 if (timer_pending(&t->T3_rtx_timer) &&
646                     del_timer(&t->T3_rtx_timer)) {
647                         sctp_transport_put(t);
648                 }
649         }
650 }
651
652
653 /* Helper function to update the heartbeat timer. */
654 static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
655                                      struct sctp_transport *t)
656 {
657         /* Update the heartbeat timer.  */
658         if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
659                 sctp_transport_hold(t);
660 }
661
662 /* Helper function to handle the reception of an HEARTBEAT ACK.  */
663 static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds,
664                                   struct sctp_association *asoc,
665                                   struct sctp_transport *t,
666                                   struct sctp_chunk *chunk)
667 {
668         sctp_sender_hb_info_t *hbinfo;
669
670         /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
671          * HEARTBEAT should clear the error counter of the destination
672          * transport address to which the HEARTBEAT was sent.
673          * The association's overall error count is also cleared.
674          */
675         t->error_count = 0;
676         t->asoc->overall_error_count = 0;
677
678         /* Clear the hb_sent flag to signal that we had a good
679          * acknowledgement.
680          */
681         t->hb_sent = 0;
682
683         /* Mark the destination transport address as active if it is not so
684          * marked.
685          */
686         if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED))
687                 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
688                                              SCTP_HEARTBEAT_SUCCESS);
689
690         /* The receiver of the HEARTBEAT ACK should also perform an
691          * RTT measurement for that destination transport address
692          * using the time value carried in the HEARTBEAT ACK chunk.
693          * If the transport's rto_pending variable has been cleared,
694          * it was most likely due to a retransmit.  However, we want
695          * to re-enable it to properly update the rto.
696          */
697         if (t->rto_pending == 0)
698                 t->rto_pending = 1;
699
700         hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
701         sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
702
703         /* Update the heartbeat timer.  */
704         if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
705                 sctp_transport_hold(t);
706 }
707
708
709 /* Helper function to process the process SACK command.  */
710 static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds,
711                                  struct sctp_association *asoc,
712                                  struct sctp_sackhdr *sackh)
713 {
714         int err = 0;
715
716         if (sctp_outq_sack(&asoc->outqueue, sackh)) {
717                 /* There are no more TSNs awaiting SACK.  */
718                 err = sctp_do_sm(SCTP_EVENT_T_OTHER,
719                                  SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
720                                  asoc->state, asoc->ep, asoc, NULL,
721                                  GFP_ATOMIC);
722         }
723
724         return err;
725 }
726
727 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
728  * the transport for a shutdown chunk.
729  */
730 static void sctp_cmd_setup_t2(sctp_cmd_seq_t *cmds,
731                               struct sctp_association *asoc,
732                               struct sctp_chunk *chunk)
733 {
734         struct sctp_transport *t;
735
736         if (chunk->transport)
737                 t = chunk->transport;
738         else {
739                 t = sctp_assoc_choose_alter_transport(asoc,
740                                               asoc->shutdown_last_sent_to);
741                 chunk->transport = t;
742         }
743         asoc->shutdown_last_sent_to = t;
744         asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
745 }
746
747 /* Helper function to change the state of an association. */
748 static void sctp_cmd_new_state(sctp_cmd_seq_t *cmds,
749                                struct sctp_association *asoc,
750                                sctp_state_t state)
751 {
752         struct sock *sk = asoc->base.sk;
753
754         asoc->state = state;
755
756         SCTP_DEBUG_PRINTK("sctp_cmd_new_state: asoc %p[%s]\n",
757                           asoc, sctp_state_tbl[state]);
758
759         if (sctp_style(sk, TCP)) {
760                 /* Change the sk->sk_state of a TCP-style socket that has
761                  * successfully completed a connect() call.
762                  */
763                 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
764                         sk->sk_state = SCTP_SS_ESTABLISHED;
765
766                 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
767                 if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
768                     sctp_sstate(sk, ESTABLISHED))
769                         sk->sk_shutdown |= RCV_SHUTDOWN;
770         }
771
772         if (sctp_state(asoc, COOKIE_WAIT)) {
773                 /* Reset init timeouts since they may have been
774                  * increased due to timer expirations.
775                  */
776                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
777                                                 asoc->rto_initial;
778                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
779                                                 asoc->rto_initial;
780         }
781
782         if (sctp_state(asoc, ESTABLISHED) ||
783             sctp_state(asoc, CLOSED) ||
784             sctp_state(asoc, SHUTDOWN_RECEIVED)) {
785                 /* Wake up any processes waiting in the asoc's wait queue in
786                  * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
787                  */
788                 if (waitqueue_active(&asoc->wait))
789                         wake_up_interruptible(&asoc->wait);
790
791                 /* Wake up any processes waiting in the sk's sleep queue of
792                  * a TCP-style or UDP-style peeled-off socket in
793                  * sctp_wait_for_accept() or sctp_wait_for_packet().
794                  * For a UDP-style socket, the waiters are woken up by the
795                  * notifications.
796                  */
797                 if (!sctp_style(sk, UDP))
798                         sk->sk_state_change(sk);
799         }
800 }
801
802 /* Helper function to delete an association. */
803 static void sctp_cmd_delete_tcb(sctp_cmd_seq_t *cmds,
804                                 struct sctp_association *asoc)
805 {
806         struct sock *sk = asoc->base.sk;
807
808         /* If it is a non-temporary association belonging to a TCP-style
809          * listening socket that is not closed, do not free it so that accept()
810          * can pick it up later.
811          */
812         if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
813             (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
814                 return;
815
816         sctp_unhash_established(asoc);
817         sctp_association_free(asoc);
818 }
819
820 /*
821  * ADDIP Section 4.1 ASCONF Chunk Procedures
822  * A4) Start a T-4 RTO timer, using the RTO value of the selected
823  * destination address (we use active path instead of primary path just
824  * because primary path may be inactive.
825  */
826 static void sctp_cmd_setup_t4(sctp_cmd_seq_t *cmds,
827                                 struct sctp_association *asoc,
828                                 struct sctp_chunk *chunk)
829 {
830         struct sctp_transport *t;
831
832         t = sctp_assoc_choose_alter_transport(asoc, chunk->transport);
833         asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
834         chunk->transport = t;
835 }
836
837 /* Process an incoming Operation Error Chunk. */
838 static void sctp_cmd_process_operr(sctp_cmd_seq_t *cmds,
839                                    struct sctp_association *asoc,
840                                    struct sctp_chunk *chunk)
841 {
842         struct sctp_errhdr *err_hdr;
843         struct sctp_ulpevent *ev;
844
845         while (chunk->chunk_end > chunk->skb->data) {
846                 err_hdr = (struct sctp_errhdr *)(chunk->skb->data);
847
848                 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
849                                                      GFP_ATOMIC);
850                 if (!ev)
851                         return;
852
853                 sctp_ulpq_tail_event(&asoc->ulpq, ev);
854
855                 switch (err_hdr->cause) {
856                 case SCTP_ERROR_UNKNOWN_CHUNK:
857                 {
858                         sctp_chunkhdr_t *unk_chunk_hdr;
859
860                         unk_chunk_hdr = (sctp_chunkhdr_t *)err_hdr->variable;
861                         switch (unk_chunk_hdr->type) {
862                         /* ADDIP 4.1 A9) If the peer responds to an ASCONF with
863                          * an ERROR chunk reporting that it did not recognized
864                          * the ASCONF chunk type, the sender of the ASCONF MUST
865                          * NOT send any further ASCONF chunks and MUST stop its
866                          * T-4 timer.
867                          */
868                         case SCTP_CID_ASCONF:
869                                 if (asoc->peer.asconf_capable == 0)
870                                         break;
871
872                                 asoc->peer.asconf_capable = 0;
873                                 sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
874                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
875                                 break;
876                         default:
877                                 break;
878                         }
879                         break;
880                 }
881                 default:
882                         break;
883                 }
884         }
885 }
886
887 /* Process variable FWDTSN chunk information. */
888 static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq,
889                                     struct sctp_chunk *chunk)
890 {
891         struct sctp_fwdtsn_skip *skip;
892         /* Walk through all the skipped SSNs */
893         sctp_walk_fwdtsn(skip, chunk) {
894                 sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
895         }
896 }
897
898 /* Helper function to remove the association non-primary peer
899  * transports.
900  */
901 static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
902 {
903         struct sctp_transport *t;
904         struct list_head *pos;
905         struct list_head *temp;
906
907         list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
908                 t = list_entry(pos, struct sctp_transport, transports);
909                 if (!sctp_cmp_addr_exact(&t->ipaddr,
910                                          &asoc->peer.primary_addr)) {
911                         sctp_assoc_del_peer(asoc, &t->ipaddr);
912                 }
913         }
914 }
915
916 /* Helper function to set sk_err on a 1-1 style socket. */
917 static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
918 {
919         struct sock *sk = asoc->base.sk;
920
921         if (!sctp_style(sk, UDP))
922                 sk->sk_err = error;
923 }
924
925 /* Helper function to generate an association change event */
926 static void sctp_cmd_assoc_change(sctp_cmd_seq_t *commands,
927                                  struct sctp_association *asoc,
928                                  u8 state)
929 {
930         struct sctp_ulpevent *ev;
931
932         ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0,
933                                             asoc->c.sinit_num_ostreams,
934                                             asoc->c.sinit_max_instreams,
935                                             NULL, GFP_ATOMIC);
936         if (ev)
937                 sctp_ulpq_tail_event(&asoc->ulpq, ev);
938 }
939
940 /* Helper function to generate an adaptation indication event */
941 static void sctp_cmd_adaptation_ind(sctp_cmd_seq_t *commands,
942                                     struct sctp_association *asoc)
943 {
944         struct sctp_ulpevent *ev;
945
946         ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
947
948         if (ev)
949                 sctp_ulpq_tail_event(&asoc->ulpq, ev);
950 }
951
952
953 static void sctp_cmd_t1_timer_update(struct sctp_association *asoc,
954                                     sctp_event_timeout_t timer,
955                                     char *name)
956 {
957         struct sctp_transport *t;
958
959         t = asoc->init_last_sent_to;
960         asoc->init_err_counter++;
961
962         if (t->init_sent_count > (asoc->init_cycle + 1)) {
963                 asoc->timeouts[timer] *= 2;
964                 if (asoc->timeouts[timer] > asoc->max_init_timeo) {
965                         asoc->timeouts[timer] = asoc->max_init_timeo;
966                 }
967                 asoc->init_cycle++;
968                 SCTP_DEBUG_PRINTK(
969                         "T1 %s Timeout adjustment"
970                         " init_err_counter: %d"
971                         " cycle: %d"
972                         " timeout: %ld\n",
973                         name,
974                         asoc->init_err_counter,
975                         asoc->init_cycle,
976                         asoc->timeouts[timer]);
977         }
978
979 }
980
981 /* Send the whole message, chunk by chunk, to the outqueue.
982  * This way the whole message is queued up and bundling if
983  * encouraged for small fragments.
984  */
985 static int sctp_cmd_send_msg(struct sctp_association *asoc,
986                                 struct sctp_datamsg *msg)
987 {
988         struct sctp_chunk *chunk;
989         int error = 0;
990
991         list_for_each_entry(chunk, &msg->chunks, frag_list) {
992                 error = sctp_outq_tail(&asoc->outqueue, chunk);
993                 if (error)
994                         break;
995         }
996
997         return error;
998 }
999
1000
1001 /* Sent the next ASCONF packet currently stored in the association.
1002  * This happens after the ASCONF_ACK was succeffully processed.
1003  */
1004 static void sctp_cmd_send_asconf(struct sctp_association *asoc)
1005 {
1006         /* Send the next asconf chunk from the addip chunk
1007          * queue.
1008          */
1009         if (!list_empty(&asoc->addip_chunk_list)) {
1010                 struct list_head *entry = asoc->addip_chunk_list.next;
1011                 struct sctp_chunk *asconf = list_entry(entry,
1012                                                 struct sctp_chunk, list);
1013                 list_del_init(entry);
1014
1015                 /* Hold the chunk until an ASCONF_ACK is received. */
1016                 sctp_chunk_hold(asconf);
1017                 if (sctp_primitive_ASCONF(asoc, asconf))
1018                         sctp_chunk_free(asconf);
1019                 else
1020                         asoc->addip_last_asconf = asconf;
1021         }
1022 }
1023
1024
1025 /* These three macros allow us to pull the debugging code out of the
1026  * main flow of sctp_do_sm() to keep attention focused on the real
1027  * functionality there.
1028  */
1029 #define DEBUG_PRE \
1030         SCTP_DEBUG_PRINTK("sctp_do_sm prefn: " \
1031                           "ep %p, %s, %s, asoc %p[%s], %s\n", \
1032                           ep, sctp_evttype_tbl[event_type], \
1033                           (*debug_fn)(subtype), asoc, \
1034                           sctp_state_tbl[state], state_fn->name)
1035
1036 #define DEBUG_POST \
1037         SCTP_DEBUG_PRINTK("sctp_do_sm postfn: " \
1038                           "asoc %p, status: %s\n", \
1039                           asoc, sctp_status_tbl[status])
1040
1041 #define DEBUG_POST_SFX \
1042         SCTP_DEBUG_PRINTK("sctp_do_sm post sfx: error %d, asoc %p[%s]\n", \
1043                           error, asoc, \
1044                           sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
1045                           sctp_assoc2id(asoc)))?asoc->state:SCTP_STATE_CLOSED])
1046
1047 /*
1048  * This is the master state machine processing function.
1049  *
1050  * If you want to understand all of lksctp, this is a
1051  * good place to start.
1052  */
1053 int sctp_do_sm(sctp_event_t event_type, sctp_subtype_t subtype,
1054                sctp_state_t state,
1055                struct sctp_endpoint *ep,
1056                struct sctp_association *asoc,
1057                void *event_arg,
1058                gfp_t gfp)
1059 {
1060         sctp_cmd_seq_t commands;
1061         const sctp_sm_table_entry_t *state_fn;
1062         sctp_disposition_t status;
1063         int error = 0;
1064         typedef const char *(printfn_t)(sctp_subtype_t);
1065
1066         static printfn_t *table[] = {
1067                 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
1068         };
1069         printfn_t *debug_fn  __attribute__ ((unused)) = table[event_type];
1070
1071         /* Look up the state function, run it, and then process the
1072          * side effects.  These three steps are the heart of lksctp.
1073          */
1074         state_fn = sctp_sm_lookup_event(event_type, state, subtype);
1075
1076         sctp_init_cmd_seq(&commands);
1077
1078         DEBUG_PRE;
1079         status = (*state_fn->fn)(ep, asoc, subtype, event_arg, &commands);
1080         DEBUG_POST;
1081
1082         error = sctp_side_effects(event_type, subtype, state,
1083                                   ep, asoc, event_arg, status,
1084                                   &commands, gfp);
1085         DEBUG_POST_SFX;
1086
1087         return error;
1088 }
1089
1090 #undef DEBUG_PRE
1091 #undef DEBUG_POST
1092
1093 /*****************************************************************
1094  * This the master state function side effect processing function.
1095  *****************************************************************/
1096 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
1097                              sctp_state_t state,
1098                              struct sctp_endpoint *ep,
1099                              struct sctp_association *asoc,
1100                              void *event_arg,
1101                              sctp_disposition_t status,
1102                              sctp_cmd_seq_t *commands,
1103                              gfp_t gfp)
1104 {
1105         int error;
1106
1107         /* FIXME - Most of the dispositions left today would be categorized
1108          * as "exceptional" dispositions.  For those dispositions, it
1109          * may not be proper to run through any of the commands at all.
1110          * For example, the command interpreter might be run only with
1111          * disposition SCTP_DISPOSITION_CONSUME.
1112          */
1113         if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
1114                                                ep, asoc,
1115                                                event_arg, status,
1116                                                commands, gfp)))
1117                 goto bail;
1118
1119         switch (status) {
1120         case SCTP_DISPOSITION_DISCARD:
1121                 SCTP_DEBUG_PRINTK("Ignored sctp protocol event - state %d, "
1122                                   "event_type %d, event_id %d\n",
1123                                   state, event_type, subtype.chunk);
1124                 break;
1125
1126         case SCTP_DISPOSITION_NOMEM:
1127                 /* We ran out of memory, so we need to discard this
1128                  * packet.
1129                  */
1130                 /* BUG--we should now recover some memory, probably by
1131                  * reneging...
1132                  */
1133                 error = -ENOMEM;
1134                 break;
1135
1136         case SCTP_DISPOSITION_DELETE_TCB:
1137                 /* This should now be a command. */
1138                 break;
1139
1140         case SCTP_DISPOSITION_CONSUME:
1141         case SCTP_DISPOSITION_ABORT:
1142                 /*
1143                  * We should no longer have much work to do here as the
1144                  * real work has been done as explicit commands above.
1145                  */
1146                 break;
1147
1148         case SCTP_DISPOSITION_VIOLATION:
1149                 if (net_ratelimit())
1150                         pr_err("protocol violation state %d chunkid %d\n",
1151                                state, subtype.chunk);
1152                 break;
1153
1154         case SCTP_DISPOSITION_NOT_IMPL:
1155                 pr_warn("unimplemented feature in state %d, event_type %d, event_id %d\n",
1156                         state, event_type, subtype.chunk);
1157                 break;
1158
1159         case SCTP_DISPOSITION_BUG:
1160                 pr_err("bug in state %d, event_type %d, event_id %d\n",
1161                        state, event_type, subtype.chunk);
1162                 BUG();
1163                 break;
1164
1165         default:
1166                 pr_err("impossible disposition %d in state %d, event_type %d, event_id %d\n",
1167                        status, state, event_type, subtype.chunk);
1168                 BUG();
1169                 break;
1170         }
1171
1172 bail:
1173         return error;
1174 }
1175
1176 /********************************************************************
1177  * 2nd Level Abstractions
1178  ********************************************************************/
1179
1180 /* This is the side-effect interpreter.  */
1181 static int sctp_cmd_interpreter(sctp_event_t event_type,
1182                                 sctp_subtype_t subtype,
1183                                 sctp_state_t state,
1184                                 struct sctp_endpoint *ep,
1185                                 struct sctp_association *asoc,
1186                                 void *event_arg,
1187                                 sctp_disposition_t status,
1188                                 sctp_cmd_seq_t *commands,
1189                                 gfp_t gfp)
1190 {
1191         int error = 0;
1192         int force;
1193         sctp_cmd_t *cmd;
1194         struct sctp_chunk *new_obj;
1195         struct sctp_chunk *chunk = NULL;
1196         struct sctp_packet *packet;
1197         struct timer_list *timer;
1198         unsigned long timeout;
1199         struct sctp_transport *t;
1200         struct sctp_sackhdr sackh;
1201         int local_cork = 0;
1202
1203         if (SCTP_EVENT_T_TIMEOUT != event_type)
1204                 chunk = (struct sctp_chunk *) event_arg;
1205
1206         /* Note:  This whole file is a huge candidate for rework.
1207          * For example, each command could either have its own handler, so
1208          * the loop would look like:
1209          *     while (cmds)
1210          *         cmd->handle(x, y, z)
1211          * --jgrimm
1212          */
1213         while (NULL != (cmd = sctp_next_cmd(commands))) {
1214                 switch (cmd->verb) {
1215                 case SCTP_CMD_NOP:
1216                         /* Do nothing. */
1217                         break;
1218
1219                 case SCTP_CMD_NEW_ASOC:
1220                         /* Register a new association.  */
1221                         if (local_cork) {
1222                                 sctp_outq_uncork(&asoc->outqueue);
1223                                 local_cork = 0;
1224                         }
1225                         asoc = cmd->obj.ptr;
1226                         /* Register with the endpoint.  */
1227                         sctp_endpoint_add_asoc(ep, asoc);
1228                         sctp_hash_established(asoc);
1229                         break;
1230
1231                 case SCTP_CMD_UPDATE_ASSOC:
1232                        sctp_assoc_update(asoc, cmd->obj.ptr);
1233                        break;
1234
1235                 case SCTP_CMD_PURGE_OUTQUEUE:
1236                        sctp_outq_teardown(&asoc->outqueue);
1237                        break;
1238
1239                 case SCTP_CMD_DELETE_TCB:
1240                         if (local_cork) {
1241                                 sctp_outq_uncork(&asoc->outqueue);
1242                                 local_cork = 0;
1243                         }
1244                         /* Delete the current association.  */
1245                         sctp_cmd_delete_tcb(commands, asoc);
1246                         asoc = NULL;
1247                         break;
1248
1249                 case SCTP_CMD_NEW_STATE:
1250                         /* Enter a new state.  */
1251                         sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1252                         break;
1253
1254                 case SCTP_CMD_REPORT_TSN:
1255                         /* Record the arrival of a TSN.  */
1256                         error = sctp_tsnmap_mark(&asoc->peer.tsn_map,
1257                                                  cmd->obj.u32);
1258                         break;
1259
1260                 case SCTP_CMD_REPORT_FWDTSN:
1261                         /* Move the Cumulattive TSN Ack ahead. */
1262                         sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32);
1263
1264                         /* purge the fragmentation queue */
1265                         sctp_ulpq_reasm_flushtsn(&asoc->ulpq, cmd->obj.u32);
1266
1267                         /* Abort any in progress partial delivery. */
1268                         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
1269                         break;
1270
1271                 case SCTP_CMD_PROCESS_FWDTSN:
1272                         sctp_cmd_process_fwdtsn(&asoc->ulpq, cmd->obj.ptr);
1273                         break;
1274
1275                 case SCTP_CMD_GEN_SACK:
1276                         /* Generate a Selective ACK.
1277                          * The argument tells us whether to just count
1278                          * the packet and MAYBE generate a SACK, or
1279                          * force a SACK out.
1280                          */
1281                         force = cmd->obj.i32;
1282                         error = sctp_gen_sack(asoc, force, commands);
1283                         break;
1284
1285                 case SCTP_CMD_PROCESS_SACK:
1286                         /* Process an inbound SACK.  */
1287                         error = sctp_cmd_process_sack(commands, asoc,
1288                                                       cmd->obj.ptr);
1289                         break;
1290
1291                 case SCTP_CMD_GEN_INIT_ACK:
1292                         /* Generate an INIT ACK chunk.  */
1293                         new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1294                                                      0);
1295                         if (!new_obj)
1296                                 goto nomem;
1297
1298                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1299                                         SCTP_CHUNK(new_obj));
1300                         break;
1301
1302                 case SCTP_CMD_PEER_INIT:
1303                         /* Process a unified INIT from the peer.
1304                          * Note: Only used during INIT-ACK processing.  If
1305                          * there is an error just return to the outter
1306                          * layer which will bail.
1307                          */
1308                         error = sctp_cmd_process_init(commands, asoc, chunk,
1309                                                       cmd->obj.ptr, gfp);
1310                         break;
1311
1312                 case SCTP_CMD_GEN_COOKIE_ECHO:
1313                         /* Generate a COOKIE ECHO chunk.  */
1314                         new_obj = sctp_make_cookie_echo(asoc, chunk);
1315                         if (!new_obj) {
1316                                 if (cmd->obj.ptr)
1317                                         sctp_chunk_free(cmd->obj.ptr);
1318                                 goto nomem;
1319                         }
1320                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1321                                         SCTP_CHUNK(new_obj));
1322
1323                         /* If there is an ERROR chunk to be sent along with
1324                          * the COOKIE_ECHO, send it, too.
1325                          */
1326                         if (cmd->obj.ptr)
1327                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1328                                                 SCTP_CHUNK(cmd->obj.ptr));
1329
1330                         if (new_obj->transport) {
1331                                 new_obj->transport->init_sent_count++;
1332                                 asoc->init_last_sent_to = new_obj->transport;
1333                         }
1334
1335                         /* FIXME - Eventually come up with a cleaner way to
1336                          * enabling COOKIE-ECHO + DATA bundling during
1337                          * multihoming stale cookie scenarios, the following
1338                          * command plays with asoc->peer.retran_path to
1339                          * avoid the problem of sending the COOKIE-ECHO and
1340                          * DATA in different paths, which could result
1341                          * in the association being ABORTed if the DATA chunk
1342                          * is processed first by the server.  Checking the
1343                          * init error counter simply causes this command
1344                          * to be executed only during failed attempts of
1345                          * association establishment.
1346                          */
1347                         if ((asoc->peer.retran_path !=
1348                              asoc->peer.primary_path) &&
1349                             (asoc->init_err_counter > 0)) {
1350                                 sctp_add_cmd_sf(commands,
1351                                                 SCTP_CMD_FORCE_PRIM_RETRAN,
1352                                                 SCTP_NULL());
1353                         }
1354
1355                         break;
1356
1357                 case SCTP_CMD_GEN_SHUTDOWN:
1358                         /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1359                          * Reset error counts.
1360                          */
1361                         asoc->overall_error_count = 0;
1362
1363                         /* Generate a SHUTDOWN chunk.  */
1364                         new_obj = sctp_make_shutdown(asoc, chunk);
1365                         if (!new_obj)
1366                                 goto nomem;
1367                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1368                                         SCTP_CHUNK(new_obj));
1369                         break;
1370
1371                 case SCTP_CMD_CHUNK_ULP:
1372                         /* Send a chunk to the sockets layer.  */
1373                         SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1374                                           "chunk_up:", cmd->obj.ptr,
1375                                           "ulpq:", &asoc->ulpq);
1376                         sctp_ulpq_tail_data(&asoc->ulpq, cmd->obj.ptr,
1377                                             GFP_ATOMIC);
1378                         break;
1379
1380                 case SCTP_CMD_EVENT_ULP:
1381                         /* Send a notification to the sockets layer.  */
1382                         SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1383                                           "event_up:",cmd->obj.ptr,
1384                                           "ulpq:",&asoc->ulpq);
1385                         sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ptr);
1386                         break;
1387
1388                 case SCTP_CMD_REPLY:
1389                         /* If an caller has not already corked, do cork. */
1390                         if (!asoc->outqueue.cork) {
1391                                 sctp_outq_cork(&asoc->outqueue);
1392                                 local_cork = 1;
1393                         }
1394                         /* Send a chunk to our peer.  */
1395                         error = sctp_outq_tail(&asoc->outqueue, cmd->obj.ptr);
1396                         break;
1397
1398                 case SCTP_CMD_SEND_PKT:
1399                         /* Send a full packet to our peer.  */
1400                         packet = cmd->obj.ptr;
1401                         sctp_packet_transmit(packet);
1402                         sctp_ootb_pkt_free(packet);
1403                         break;
1404
1405                 case SCTP_CMD_T1_RETRAN:
1406                         /* Mark a transport for retransmission.  */
1407                         sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1408                                         SCTP_RTXR_T1_RTX);
1409                         break;
1410
1411                 case SCTP_CMD_RETRAN:
1412                         /* Mark a transport for retransmission.  */
1413                         sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1414                                         SCTP_RTXR_T3_RTX);
1415                         break;
1416
1417                 case SCTP_CMD_ECN_CE:
1418                         /* Do delayed CE processing.   */
1419                         sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1420                         break;
1421
1422                 case SCTP_CMD_ECN_ECNE:
1423                         /* Do delayed ECNE processing. */
1424                         new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1425                                                         chunk);
1426                         if (new_obj)
1427                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1428                                                 SCTP_CHUNK(new_obj));
1429                         break;
1430
1431                 case SCTP_CMD_ECN_CWR:
1432                         /* Do delayed CWR processing.  */
1433                         sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1434                         break;
1435
1436                 case SCTP_CMD_SETUP_T2:
1437                         sctp_cmd_setup_t2(commands, asoc, cmd->obj.ptr);
1438                         break;
1439
1440                 case SCTP_CMD_TIMER_START:
1441                         timer = &asoc->timers[cmd->obj.to];
1442                         timeout = asoc->timeouts[cmd->obj.to];
1443                         BUG_ON(!timeout);
1444
1445                         timer->expires = jiffies + timeout;
1446                         sctp_association_hold(asoc);
1447                         add_timer(timer);
1448                         break;
1449
1450                 case SCTP_CMD_TIMER_RESTART:
1451                         timer = &asoc->timers[cmd->obj.to];
1452                         timeout = asoc->timeouts[cmd->obj.to];
1453                         if (!mod_timer(timer, jiffies + timeout))
1454                                 sctp_association_hold(asoc);
1455                         break;
1456
1457                 case SCTP_CMD_TIMER_STOP:
1458                         timer = &asoc->timers[cmd->obj.to];
1459                         if (timer_pending(timer) && del_timer(timer))
1460                                 sctp_association_put(asoc);
1461                         break;
1462
1463                 case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1464                         chunk = cmd->obj.ptr;
1465                         t = sctp_assoc_choose_alter_transport(asoc,
1466                                                 asoc->init_last_sent_to);
1467                         asoc->init_last_sent_to = t;
1468                         chunk->transport = t;
1469                         t->init_sent_count++;
1470                         /* Set the new transport as primary */
1471                         sctp_assoc_set_primary(asoc, t);
1472                         break;
1473
1474                 case SCTP_CMD_INIT_RESTART:
1475                         /* Do the needed accounting and updates
1476                          * associated with restarting an initialization
1477                          * timer. Only multiply the timeout by two if
1478                          * all transports have been tried at the current
1479                          * timeout.
1480                          */
1481                         sctp_cmd_t1_timer_update(asoc,
1482                                                 SCTP_EVENT_TIMEOUT_T1_INIT,
1483                                                 "INIT");
1484
1485                         sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1486                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1487                         break;
1488
1489                 case SCTP_CMD_COOKIEECHO_RESTART:
1490                         /* Do the needed accounting and updates
1491                          * associated with restarting an initialization
1492                          * timer. Only multiply the timeout by two if
1493                          * all transports have been tried at the current
1494                          * timeout.
1495                          */
1496                         sctp_cmd_t1_timer_update(asoc,
1497                                                 SCTP_EVENT_TIMEOUT_T1_COOKIE,
1498                                                 "COOKIE");
1499
1500                         /* If we've sent any data bundled with
1501                          * COOKIE-ECHO we need to resend.
1502                          */
1503                         list_for_each_entry(t, &asoc->peer.transport_addr_list,
1504                                         transports) {
1505                                 sctp_retransmit_mark(&asoc->outqueue, t,
1506                                             SCTP_RTXR_T1_RTX);
1507                         }
1508
1509                         sctp_add_cmd_sf(commands,
1510                                         SCTP_CMD_TIMER_RESTART,
1511                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1512                         break;
1513
1514                 case SCTP_CMD_INIT_FAILED:
1515                         sctp_cmd_init_failed(commands, asoc, cmd->obj.err);
1516                         break;
1517
1518                 case SCTP_CMD_ASSOC_FAILED:
1519                         sctp_cmd_assoc_failed(commands, asoc, event_type,
1520                                               subtype, chunk, cmd->obj.err);
1521                         break;
1522
1523                 case SCTP_CMD_INIT_COUNTER_INC:
1524                         asoc->init_err_counter++;
1525                         break;
1526
1527                 case SCTP_CMD_INIT_COUNTER_RESET:
1528                         asoc->init_err_counter = 0;
1529                         asoc->init_cycle = 0;
1530                         list_for_each_entry(t, &asoc->peer.transport_addr_list,
1531                                             transports) {
1532                                 t->init_sent_count = 0;
1533                         }
1534                         break;
1535
1536                 case SCTP_CMD_REPORT_DUP:
1537                         sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1538                                              cmd->obj.u32);
1539                         break;
1540
1541                 case SCTP_CMD_REPORT_BAD_TAG:
1542                         SCTP_DEBUG_PRINTK("vtag mismatch!\n");
1543                         break;
1544
1545                 case SCTP_CMD_STRIKE:
1546                         /* Mark one strike against a transport.  */
1547                         sctp_do_8_2_transport_strike(asoc, cmd->obj.transport,
1548                                                     0);
1549                         break;
1550
1551                 case SCTP_CMD_TRANSPORT_IDLE:
1552                         t = cmd->obj.transport;
1553                         sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
1554                         break;
1555
1556                 case SCTP_CMD_TRANSPORT_HB_SENT:
1557                         t = cmd->obj.transport;
1558                         sctp_do_8_2_transport_strike(asoc, t, 1);
1559                         t->hb_sent = 1;
1560                         break;
1561
1562                 case SCTP_CMD_TRANSPORT_ON:
1563                         t = cmd->obj.transport;
1564                         sctp_cmd_transport_on(commands, asoc, t, chunk);
1565                         break;
1566
1567                 case SCTP_CMD_HB_TIMERS_START:
1568                         sctp_cmd_hb_timers_start(commands, asoc);
1569                         break;
1570
1571                 case SCTP_CMD_HB_TIMER_UPDATE:
1572                         t = cmd->obj.transport;
1573                         sctp_cmd_hb_timer_update(commands, t);
1574                         break;
1575
1576                 case SCTP_CMD_HB_TIMERS_STOP:
1577                         sctp_cmd_hb_timers_stop(commands, asoc);
1578                         break;
1579
1580                 case SCTP_CMD_REPORT_ERROR:
1581                         error = cmd->obj.error;
1582                         break;
1583
1584                 case SCTP_CMD_PROCESS_CTSN:
1585                         /* Dummy up a SACK for processing. */
1586                         sackh.cum_tsn_ack = cmd->obj.be32;
1587                         sackh.a_rwnd = asoc->peer.rwnd +
1588                                         asoc->outqueue.outstanding_bytes;
1589                         sackh.num_gap_ack_blocks = 0;
1590                         sackh.num_dup_tsns = 0;
1591                         sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1592                                         SCTP_SACKH(&sackh));
1593                         break;
1594
1595                 case SCTP_CMD_DISCARD_PACKET:
1596                         /* We need to discard the whole packet.
1597                          * Uncork the queue since there might be
1598                          * responses pending
1599                          */
1600                         chunk->pdiscard = 1;
1601                         if (asoc) {
1602                                 sctp_outq_uncork(&asoc->outqueue);
1603                                 local_cork = 0;
1604                         }
1605                         break;
1606
1607                 case SCTP_CMD_RTO_PENDING:
1608                         t = cmd->obj.transport;
1609                         t->rto_pending = 1;
1610                         break;
1611
1612                 case SCTP_CMD_PART_DELIVER:
1613                         sctp_ulpq_partial_delivery(&asoc->ulpq, cmd->obj.ptr,
1614                                                    GFP_ATOMIC);
1615                         break;
1616
1617                 case SCTP_CMD_RENEGE:
1618                         sctp_ulpq_renege(&asoc->ulpq, cmd->obj.ptr,
1619                                          GFP_ATOMIC);
1620                         break;
1621
1622                 case SCTP_CMD_SETUP_T4:
1623                         sctp_cmd_setup_t4(commands, asoc, cmd->obj.ptr);
1624                         break;
1625
1626                 case SCTP_CMD_PROCESS_OPERR:
1627                         sctp_cmd_process_operr(commands, asoc, chunk);
1628                         break;
1629                 case SCTP_CMD_CLEAR_INIT_TAG:
1630                         asoc->peer.i.init_tag = 0;
1631                         break;
1632                 case SCTP_CMD_DEL_NON_PRIMARY:
1633                         sctp_cmd_del_non_primary(asoc);
1634                         break;
1635                 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1636                         sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1637                         break;
1638                 case SCTP_CMD_FORCE_PRIM_RETRAN:
1639                         t = asoc->peer.retran_path;
1640                         asoc->peer.retran_path = asoc->peer.primary_path;
1641                         error = sctp_outq_uncork(&asoc->outqueue);
1642                         local_cork = 0;
1643                         asoc->peer.retran_path = t;
1644                         break;
1645                 case SCTP_CMD_SET_SK_ERR:
1646                         sctp_cmd_set_sk_err(asoc, cmd->obj.error);
1647                         break;
1648                 case SCTP_CMD_ASSOC_CHANGE:
1649                         sctp_cmd_assoc_change(commands, asoc,
1650                                               cmd->obj.u8);
1651                         break;
1652                 case SCTP_CMD_ADAPTATION_IND:
1653                         sctp_cmd_adaptation_ind(commands, asoc);
1654                         break;
1655
1656                 case SCTP_CMD_ASSOC_SHKEY:
1657                         error = sctp_auth_asoc_init_active_key(asoc,
1658                                                 GFP_ATOMIC);
1659                         break;
1660                 case SCTP_CMD_UPDATE_INITTAG:
1661                         asoc->peer.i.init_tag = cmd->obj.u32;
1662                         break;
1663                 case SCTP_CMD_SEND_MSG:
1664                         if (!asoc->outqueue.cork) {
1665                                 sctp_outq_cork(&asoc->outqueue);
1666                                 local_cork = 1;
1667                         }
1668                         error = sctp_cmd_send_msg(asoc, cmd->obj.msg);
1669                         break;
1670                 case SCTP_CMD_SEND_NEXT_ASCONF:
1671                         sctp_cmd_send_asconf(asoc);
1672                         break;
1673                 case SCTP_CMD_PURGE_ASCONF_QUEUE:
1674                         sctp_asconf_queue_teardown(asoc);
1675                         break;
1676                 default:
1677                         pr_warn("Impossible command: %u, %p\n",
1678                                 cmd->verb, cmd->obj.ptr);
1679                         break;
1680                 }
1681
1682                 if (error)
1683                         break;
1684         }
1685
1686 out:
1687         /* If this is in response to a received chunk, wait until
1688          * we are done with the packet to open the queue so that we don't
1689          * send multiple packets in response to a single request.
1690          */
1691         if (asoc && SCTP_EVENT_T_CHUNK == event_type && chunk) {
1692                 if (chunk->end_of_packet || chunk->singleton)
1693                         error = sctp_outq_uncork(&asoc->outqueue);
1694         } else if (local_cork)
1695                 error = sctp_outq_uncork(&asoc->outqueue);
1696         return error;
1697 nomem:
1698         error = -ENOMEM;
1699         goto out;
1700 }
1701