net/sctp/sm_sideeffect.c

   1 /* SCTP kernel reference Implementation
   2  * (C) Copyright IBM Corp. 2001, 2004
   3  * Copyright (c) 1999 Cisco, Inc.
   4  * Copyright (c) 1999-2001 Motorola, Inc.
   5  *
   6  * This file is part of the SCTP kernel reference Implementation
   7  *
   8  * These functions work with the state functions in sctp_sm_statefuns.c
   9  * to implement that state operations.  These functions implement the
  10  * steps which require modifying existing data structures.
  11  *
  12  * The SCTP reference implementation is free software;
  13  * you can redistribute it and/or modify it under the terms of
  14  * the GNU General Public License as published by
  15  * the Free Software Foundation; either version 2, or (at your option)
  16  * any later version.
  17  *
  18  * The SCTP reference implementation is distributed in the hope that it
  19  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
  20  *                 ************************
  21  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  22  * See the GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with GNU CC; see the file COPYING.  If not, write to
  26  * the Free Software Foundation, 59 Temple Place - Suite 330,
  27  * Boston, MA 02111-1307, USA.
  28  *
  29  * Please send any bug reports or fixes you make to the
  30  * email address(es):
  31  *    lksctp developers <lksctp-developers@lists.sourceforge.net>
  32  *
  33  * Or submit a bug report through the following website:
  34  *    http://www.sf.net/projects/lksctp
  35  *
  36  * Written or modified by:
  37  *    La Monte H.P. Yarroll <piggy@acm.org>
  38  *    Karl Knutson          <karl@athena.chicago.il.us>
  39  *    Jon Grimm             <jgrimm@austin.ibm.com>
  40  *    Hui Huang             <hui.huang@nokia.com>
  41  *    Dajiang Zhang         <dajiang.zhang@nokia.com>
  42  *    Daisy Chang           <daisyc@us.ibm.com>
  43  *    Sridhar Samudrala     <sri@us.ibm.com>
  44  *    Ardelle Fan           <ardelle.fan@intel.com>
  45  *
  46  * Any bugs reported given to us we will try to fix... any fixes shared will
  47  * be incorporated into the next SCTP release.
  48  */
  49
  50 #include <linux/skbuff.h>
  51 #include <linux/types.h>
  52 #include <linux/socket.h>
  53 #include <linux/ip.h>
  54 #include <net/sock.h>
  55 #include <net/sctp/sctp.h>
  56 #include <net/sctp/sm.h>
  57
  58 static int sctp_cmd_interpreter(sctp_event_t event_type,
  59                                 sctp_subtype_t subtype,
  60                                 sctp_state_t state,
  61                                 struct sctp_endpoint *ep,
  62                                 struct sctp_association *asoc,
  63                                 void *event_arg,
  64                                 sctp_disposition_t status,
  65                                 sctp_cmd_seq_t *commands,
  66                                 int gfp);
  67 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
  68                              sctp_state_t state,
  69                              struct sctp_endpoint *ep,
  70                              struct sctp_association *asoc,
  71                              void *event_arg,
  72                              sctp_disposition_t status,
  73                              sctp_cmd_seq_t *commands,
  74                              int gfp);
  75
  76 /********************************************************************
  77  * Helper functions
  78  ********************************************************************/
  79
  80 /* A helper function for delayed processing of INET ECN CE bit. */
  81 static void sctp_do_ecn_ce_work(struct sctp_association *asoc,
  82                                 __u32 lowest_tsn)
  83 {
  84         /* Save the TSN away for comparison when we receive CWR */
  85
  86         asoc->last_ecne_tsn = lowest_tsn;
  87         asoc->need_ecne = 1;
  88 }
  89
  90 /* Helper function for delayed processing of SCTP ECNE chunk.  */
  91 /* RFC 2960 Appendix A
  92  *
  93  * RFC 2481 details a specific bit for a sender to send in
  94  * the header of its next outbound TCP segment to indicate to
  95  * its peer that it has reduced its congestion window.  This
  96  * is termed the CWR bit.  For SCTP the same indication is made
  97  * by including the CWR chunk.  This chunk contains one data
  98  * element, i.e. the TSN number that was sent in the ECNE chunk.
  99  * This element represents the lowest TSN number in the datagram
 100  * that was originally marked with the CE bit.
 101  */
 102 static struct sctp_chunk *sctp_do_ecn_ecne_work(struct sctp_association *asoc,
 103                                            __u32 lowest_tsn,
 104                                            struct sctp_chunk *chunk)
 105 {
 106         struct sctp_chunk *repl;
 107
 108         /* Our previously transmitted packet ran into some congestion
 109          * so we should take action by reducing cwnd and ssthresh
 110          * and then ACK our peer that we we've done so by
 111          * sending a CWR.
 112          */
 113
 114         /* First, try to determine if we want to actually lower
 115          * our cwnd variables.  Only lower them if the ECNE looks more
 116          * recent than the last response.
 117          */
 118         if (TSN_lt(asoc->last_cwr_tsn, lowest_tsn)) {
 119                 struct sctp_transport *transport;
 120
 121                 /* Find which transport's congestion variables
 122                  * need to be adjusted.
 123                  */
 124                 transport = sctp_assoc_lookup_tsn(asoc, lowest_tsn);
 125
 126                 /* Update the congestion variables. */
 127                 if (transport)
 128                         sctp_transport_lower_cwnd(transport,
 129                                                   SCTP_LOWER_CWND_ECNE);
 130                 asoc->last_cwr_tsn = lowest_tsn;
 131         }
 132
 133         /* Always try to quiet the other end.  In case of lost CWR,
 134          * resend last_cwr_tsn.
 135          */
 136         repl = sctp_make_cwr(asoc, asoc->last_cwr_tsn, chunk);
 137
 138         /* If we run out of memory, it will look like a lost CWR.  We'll
 139          * get back in sync eventually.
 140          */
 141         return repl;
 142 }
 143
 144 /* Helper function to do delayed processing of ECN CWR chunk.  */
 145 static void sctp_do_ecn_cwr_work(struct sctp_association *asoc,
 146                                  __u32 lowest_tsn)
 147 {
 148         /* Turn off ECNE getting auto-prepended to every outgoing
 149          * packet
 150          */
 151         asoc->need_ecne = 0;
 152 }
 153
 154 /* Generate SACK if necessary.  We call this at the end of a packet.  */
 155 static int sctp_gen_sack(struct sctp_association *asoc, int force,
 156                          sctp_cmd_seq_t *commands)
 157 {
 158         __u32 ctsn, max_tsn_seen;
 159         struct sctp_chunk *sack;
 160         int error = 0;
 161
 162         if (force)
 163                 asoc->peer.sack_needed = 1;
 164
 165         ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
 166         max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
 167
 168         /* From 12.2 Parameters necessary per association (i.e. the TCB):
 169          *
 170          * Ack State : This flag indicates if the next received packet
 171          *           : is to be responded to with a SACK. ...
 172          *           : When DATA chunks are out of order, SACK's
 173          *           : are not delayed (see Section 6).
 174          *
 175          * [This is actually not mentioned in Section 6, but we
 176          * implement it here anyway. --piggy]
 177          */
 178         if (max_tsn_seen != ctsn)
 179                 asoc->peer.sack_needed = 1;
 180
 181         /* From 6.2  Acknowledgement on Reception of DATA Chunks:
 182          *
 183          * Section 4.2 of [RFC2581] SHOULD be followed. Specifically,
 184          * an acknowledgement SHOULD be generated for at least every
 185          * second packet (not every second DATA chunk) received, and
 186          * SHOULD be generated within 200 ms of the arrival of any
 187          * unacknowledged DATA chunk. ...
 188          */
 189         if (!asoc->peer.sack_needed) {
 190                 /* We will need a SACK for the next packet.  */
 191                 asoc->peer.sack_needed = 1;
 192                 goto out;
 193         } else {
 194                 if (asoc->a_rwnd > asoc->rwnd)
 195                         asoc->a_rwnd = asoc->rwnd;
 196                 sack = sctp_make_sack(asoc);
 197                 if (!sack)
 198                         goto nomem;
 199
 200                 asoc->peer.sack_needed = 0;
 201
 202                 error = sctp_outq_tail(&asoc->outqueue, sack);
 203
 204                 /* Stop the SACK timer.  */
 205                 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
 206                                 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
 207         }
 208 out:
 209         return error;
 210 nomem:
 211         error = -ENOMEM;
 212         return error;
 213 }
 214
 215 /* When the T3-RTX timer expires, it calls this function to create the
 216  * relevant state machine event.
 217  */
 218 void sctp_generate_t3_rtx_event(unsigned long peer)
 219 {
 220         int error;
 221         struct sctp_transport *transport = (struct sctp_transport *) peer;
 222         struct sctp_association *asoc = transport->asoc;
 223
 224         /* Check whether a task is in the sock.  */
 225
 226         sctp_bh_lock_sock(asoc->base.sk);
 227         if (sock_owned_by_user(asoc->base.sk)) {
 228                 SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __FUNCTION__);
 229
 230                 /* Try again later.  */
 231                 if (!mod_timer(&transport->T3_rtx_timer, jiffies + (HZ/20)))
 232                         sctp_transport_hold(transport);
 233                 goto out_unlock;
 234         }
 235
 236         /* Is this transport really dead and just waiting around for
 237          * the timer to let go of the reference?
 238          */
 239         if (transport->dead)
 240                 goto out_unlock;
 241
 242         /* Run through the state machine.  */
 243         error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
 244                            SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX),
 245                            asoc->state,
 246                            asoc->ep, asoc,
 247                            transport, GFP_ATOMIC);
 248
 249         if (error)
 250                 asoc->base.sk->sk_err = -error;
 251
 252 out_unlock:
 253         sctp_bh_unlock_sock(asoc->base.sk);
 254         sctp_transport_put(transport);
 255 }
 256
 257 /* This is a sa interface for producing timeout events.  It works
 258  * for timeouts which use the association as their parameter.
 259  */
 260 static void sctp_generate_timeout_event(struct sctp_association *asoc,
 261                                         sctp_event_timeout_t timeout_type)
 262 {
 263         int error = 0;
 264
 265         sctp_bh_lock_sock(asoc->base.sk);
 266         if (sock_owned_by_user(asoc->base.sk)) {
 267                 SCTP_DEBUG_PRINTK("%s:Sock is busy: timer %d\n",
 268                                   __FUNCTION__,
 269                                   timeout_type);
 270
 271                 /* Try again later.  */
 272                 if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20)))
 273                         sctp_association_hold(asoc);
 274                 goto out_unlock;
 275         }
 276
 277         /* Is this association really dead and just waiting around for
 278          * the timer to let go of the reference?
 279          */
 280         if (asoc->base.dead)
 281                 goto out_unlock;
 282
 283         /* Run through the state machine.  */
 284         error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
 285                            SCTP_ST_TIMEOUT(timeout_type),
 286                            asoc->state, asoc->ep, asoc,
 287                            (void *)timeout_type, GFP_ATOMIC);
 288
 289         if (error)
 290                 asoc->base.sk->sk_err = -error;
 291
 292 out_unlock:
 293         sctp_bh_unlock_sock(asoc->base.sk);
 294         sctp_association_put(asoc);
 295 }
 296
 297 static void sctp_generate_t1_cookie_event(unsigned long data)
 298 {
 299         struct sctp_association *asoc = (struct sctp_association *) data;
 300         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
 301 }
 302
 303 static void sctp_generate_t1_init_event(unsigned long data)
 304 {
 305         struct sctp_association *asoc = (struct sctp_association *) data;
 306         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
 307 }
 308
 309 static void sctp_generate_t2_shutdown_event(unsigned long data)
 310 {
 311         struct sctp_association *asoc = (struct sctp_association *) data;
 312         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
 313 }
 314
 315 static void sctp_generate_t4_rto_event(unsigned long data)
 316 {
 317         struct sctp_association *asoc = (struct sctp_association *) data;
 318         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
 319 }
 320
 321 static void sctp_generate_t5_shutdown_guard_event(unsigned long data)
 322 {
 323         struct sctp_association *asoc = (struct sctp_association *)data;
 324         sctp_generate_timeout_event(asoc,
 325                                     SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);
 326
 327 } /* sctp_generate_t5_shutdown_guard_event() */
 328
 329 static void sctp_generate_autoclose_event(unsigned long data)
 330 {
 331         struct sctp_association *asoc = (struct sctp_association *) data;
 332         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE);
 333 }
 334
 335 /* Generate a heart beat event.  If the sock is busy, reschedule.   Make
 336  * sure that the transport is still valid.
 337  */
 338 void sctp_generate_heartbeat_event(unsigned long data)
 339 {
 340         int error = 0;
 341         struct sctp_transport *transport = (struct sctp_transport *) data;
 342         struct sctp_association *asoc = transport->asoc;
 343
 344         sctp_bh_lock_sock(asoc->base.sk);
 345         if (sock_owned_by_user(asoc->base.sk)) {
 346                 SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __FUNCTION__);
 347
 348                 /* Try again later.  */
 349                 if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20)))
 350                         sctp_transport_hold(transport);
 351                 goto out_unlock;
 352         }
 353
 354         /* Is this structure just waiting around for us to actually
 355          * get destroyed?
 356          */
 357         if (transport->dead)
 358                 goto out_unlock;
 359
 360         error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
 361                            SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
 362                            asoc->state, asoc->ep, asoc,
 363                            transport, GFP_ATOMIC);
 364
 365          if (error)
 366                  asoc->base.sk->sk_err = -error;
 367
 368 out_unlock:
 369         sctp_bh_unlock_sock(asoc->base.sk);
 370         sctp_transport_put(transport);
 371 }
 372
 373 /* Inject a SACK Timeout event into the state machine.  */
 374 static void sctp_generate_sack_event(unsigned long data)
 375 {
 376         struct sctp_association *asoc = (struct sctp_association *) data;
 377         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
 378 }
 379
 380 sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
 381         NULL,
 382         sctp_generate_t1_cookie_event,
 383         sctp_generate_t1_init_event,
 384         sctp_generate_t2_shutdown_event,
 385         NULL,
 386         sctp_generate_t4_rto_event,
 387         sctp_generate_t5_shutdown_guard_event,
 388         sctp_generate_heartbeat_event,
 389         sctp_generate_sack_event,
 390         sctp_generate_autoclose_event,
 391 };
 392
 393
 394 /* RFC 2960 8.2 Path Failure Detection
 395  *
 396  * When its peer endpoint is multi-homed, an endpoint should keep a
 397  * error counter for each of the destination transport addresses of the
 398  * peer endpoint.
 399  *
 400  * Each time the T3-rtx timer expires on any address, or when a
 401  * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
 402  * the error counter of that destination address will be incremented.
 403  * When the value in the error counter exceeds the protocol parameter
 404  * 'Path.Max.Retrans' of that destination address, the endpoint should
 405  * mark the destination transport address as inactive, and a
 406  * notification SHOULD be sent to the upper layer.
 407  *
 408  */
 409 static void sctp_do_8_2_transport_strike(struct sctp_association *asoc,
 410                                          struct sctp_transport *transport)
 411 {
 412         /* The check for association's overall error counter exceeding the
 413          * threshold is done in the state function.
 414          */
 415         asoc->overall_error_count++;
 416
 417         if (transport->active &&
 418             (transport->error_count++ >= transport->max_retrans)) {
 419                 SCTP_DEBUG_PRINTK("transport_strike: transport "
 420                                   "IP:%d.%d.%d.%d failed.\n",
 421                                   NIPQUAD(transport->ipaddr.v4.sin_addr));
 422                 sctp_assoc_control_transport(asoc, transport,
 423                                              SCTP_TRANSPORT_DOWN,
 424                                              SCTP_FAILED_THRESHOLD);
 425         }
 426
 427         /* E2) For the destination address for which the timer
 428          * expires, set RTO <- RTO * 2 ("back off the timer").  The
 429          * maximum value discussed in rule C7 above (RTO.max) may be
 430          * used to provide an upper bound to this doubling operation.
 431          */
 432         transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
 433 }
 434
 435 /* Worker routine to handle INIT command failure.  */
 436 static void sctp_cmd_init_failed(sctp_cmd_seq_t *commands,
 437                                  struct sctp_association *asoc,
 438                                  unsigned error)
 439 {
 440         struct sctp_ulpevent *event;
 441
 442         event = sctp_ulpevent_make_assoc_change(asoc,0, SCTP_CANT_STR_ASSOC,
 443                                                 (__u16)error, 0, 0,
 444                                                 GFP_ATOMIC);
 445
 446         if (event)
 447                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 448                                 SCTP_ULPEVENT(event));
 449
 450         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 451                         SCTP_STATE(SCTP_STATE_CLOSED));
 452
 453         /* SEND_FAILED sent later when cleaning up the association. */
 454         asoc->outqueue.error = error;
 455         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 456 }
 457
 458 /* Worker routine to handle SCTP_CMD_ASSOC_FAILED.  */
 459 static void sctp_cmd_assoc_failed(sctp_cmd_seq_t *commands,
 460                                   struct sctp_association *asoc,
 461                                   sctp_event_t event_type,
 462                                   sctp_subtype_t subtype,
 463                                   struct sctp_chunk *chunk,
 464                                   unsigned error)
 465 {
 466         struct sctp_ulpevent *event;
 467
 468         /* Cancel any partial delivery in progress. */
 469         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
 470
 471         event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
 472                                                 (__u16)error, 0, 0,
 473                                                 GFP_ATOMIC);
 474         if (event)
 475                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 476                                 SCTP_ULPEVENT(event));
 477
 478         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 479                         SCTP_STATE(SCTP_STATE_CLOSED));
 480
 481         /* Set sk_err to ECONNRESET on a 1-1 style socket. */
 482         if (!sctp_style(asoc->base.sk, UDP))
 483                 asoc->base.sk->sk_err = ECONNRESET;
 484
 485         /* SEND_FAILED sent later when cleaning up the association. */
 486         asoc->outqueue.error = error;
 487         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 488 }
 489
 490 /* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
 491  * inside the cookie.  In reality, this is only used for INIT-ACK processing
 492  * since all other cases use "temporary" associations and can do all
 493  * their work in statefuns directly.
 494  */
 495 static int sctp_cmd_process_init(sctp_cmd_seq_t *commands,
 496                                  struct sctp_association *asoc,
 497                                  struct sctp_chunk *chunk,
 498                                  sctp_init_chunk_t *peer_init, int gfp)
 499 {
 500         int error;
 501
 502         /* We only process the init as a sideeffect in a single
 503          * case.   This is when we process the INIT-ACK.   If we
 504          * fail during INIT processing (due to malloc problems),
 505          * just return the error and stop processing the stack.
 506          */
 507         if (!sctp_process_init(asoc, chunk->chunk_hdr->type,
 508                                sctp_source(chunk), peer_init, gfp))
 509                 error = -ENOMEM;
 510         else
 511                 error = 0;
 512
 513         return error;
 514 }
 515
 516 /* Helper function to break out starting up of heartbeat timers.  */
 517 static void sctp_cmd_hb_timers_start(sctp_cmd_seq_t *cmds,
 518                                      struct sctp_association *asoc)
 519 {
 520         struct sctp_transport *t;
 521         struct list_head *pos;
 522
 523         /* Start a heartbeat timer for each transport on the association.
 524          * hold a reference on the transport to make sure none of
 525          * the needed data structures go away.
 526          */
 527         list_for_each(pos, &asoc->peer.transport_addr_list) {
 528                 t = list_entry(pos, struct sctp_transport, transports);
 529
 530                 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 531                         sctp_transport_hold(t);
 532         }
 533 }
 534
 535 static void sctp_cmd_hb_timers_stop(sctp_cmd_seq_t *cmds,
 536                                     struct sctp_association *asoc)
 537 {
 538         struct sctp_transport *t;
 539         struct list_head *pos;
 540
 541         /* Stop all heartbeat timers. */
 542
 543         list_for_each(pos, &asoc->peer.transport_addr_list) {
 544                 t = list_entry(pos, struct sctp_transport, transports);
 545                 if (del_timer(&t->hb_timer))
 546                         sctp_transport_put(t);
 547         }
 548 }
 549
 550 /* Helper function to stop any pending T3-RTX timers */
 551 static void sctp_cmd_t3_rtx_timers_stop(sctp_cmd_seq_t *cmds,
 552                                         struct sctp_association *asoc)
 553 {
 554         struct sctp_transport *t;
 555         struct list_head *pos;
 556
 557         list_for_each(pos, &asoc->peer.transport_addr_list) {
 558                 t = list_entry(pos, struct sctp_transport, transports);
 559                 if (timer_pending(&t->T3_rtx_timer) &&
 560                     del_timer(&t->T3_rtx_timer)) {
 561                         sctp_transport_put(t);
 562                 }
 563         }
 564 }
 565
 566
 567 /* Helper function to update the heartbeat timer. */
 568 static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
 569                                      struct sctp_association *asoc,
 570                                      struct sctp_transport *t)
 571 {
 572         /* Update the heartbeat timer.  */
 573         if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 574                 sctp_transport_hold(t);
 575 }
 576
 577 /* Helper function to handle the reception of an HEARTBEAT ACK.  */
 578 static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds,
 579                                   struct sctp_association *asoc,
 580                                   struct sctp_transport *t,
 581                                   struct sctp_chunk *chunk)
 582 {
 583         sctp_sender_hb_info_t *hbinfo;
 584
 585         /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
 586          * HEARTBEAT should clear the error counter of the destination
 587          * transport address to which the HEARTBEAT was sent.
 588          * The association's overall error count is also cleared.
 589          */
 590         t->error_count = 0;
 591         t->asoc->overall_error_count = 0;
 592
 593         /* Mark the destination transport address as active if it is not so
 594          * marked.
 595          */
 596         if (!t->active)
 597                 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
 598                                              SCTP_HEARTBEAT_SUCCESS);
 599
 600         /* The receiver of the HEARTBEAT ACK should also perform an
 601          * RTT measurement for that destination transport address
 602          * using the time value carried in the HEARTBEAT ACK chunk.
 603          */
 604         hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
 605         sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
 606 }
 607
 608 /* Helper function to do a transport reset at the expiry of the hearbeat
 609  * timer.
 610  */
 611 static void sctp_cmd_transport_reset(sctp_cmd_seq_t *cmds,
 612                                      struct sctp_association *asoc,
 613                                      struct sctp_transport *t)
 614 {
 615         sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
 616
 617         /* Mark one strike against a transport.  */
 618         sctp_do_8_2_transport_strike(asoc, t);
 619 }
 620
 621 /* Helper function to process the process SACK command.  */
 622 static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds,
 623                                  struct sctp_association *asoc,
 624                                  struct sctp_sackhdr *sackh)
 625 {
 626         int err;
 627
 628         if (sctp_outq_sack(&asoc->outqueue, sackh)) {
 629                 /* There are no more TSNs awaiting SACK.  */
 630                 err = sctp_do_sm(SCTP_EVENT_T_OTHER,
 631                                  SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
 632                                  asoc->state, asoc->ep, asoc, NULL,
 633                                  GFP_ATOMIC);
 634         } else {
 635                 /* Windows may have opened, so we need
 636                  * to check if we have DATA to transmit
 637                  */
 638                 err = sctp_outq_flush(&asoc->outqueue, 0);
 639         }
 640
 641         return err;
 642 }
 643
 644 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
 645  * the transport for a shutdown chunk.
 646  */
 647 static void sctp_cmd_setup_t2(sctp_cmd_seq_t *cmds,
 648                               struct sctp_association *asoc,
 649                               struct sctp_chunk *chunk)
 650 {
 651         struct sctp_transport *t;
 652
 653         t = sctp_assoc_choose_shutdown_transport(asoc);
 654         asoc->shutdown_last_sent_to = t;
 655         asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
 656         chunk->transport = t;
 657 }
 658
 659 /* Helper function to change the state of an association. */
 660 static void sctp_cmd_new_state(sctp_cmd_seq_t *cmds,
 661                                struct sctp_association *asoc,
 662                                sctp_state_t state)
 663 {
 664         struct sock *sk = asoc->base.sk;
 665
 666         asoc->state = state;
 667
 668         if (sctp_style(sk, TCP)) {
 669                 /* Change the sk->sk_state of a TCP-style socket that has
 670                  * sucessfully completed a connect() call.
 671                  */
 672                 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
 673                         sk->sk_state = SCTP_SS_ESTABLISHED;
 674
 675                 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
 676                 if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
 677                     sctp_sstate(sk, ESTABLISHED))
 678                         sk->sk_shutdown |= RCV_SHUTDOWN;
 679         }
 680
 681         if (sctp_state(asoc, ESTABLISHED) ||
 682             sctp_state(asoc, CLOSED) ||
 683             sctp_state(asoc, SHUTDOWN_RECEIVED)) {
 684                 /* Wake up any processes waiting in the asoc's wait queue in
 685                  * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
 686                  */
 687                 if (waitqueue_active(&asoc->wait))
 688                         wake_up_interruptible(&asoc->wait);
 689
 690                 /* Wake up any processes waiting in the sk's sleep queue of
 691                  * a TCP-style or UDP-style peeled-off socket in
 692                  * sctp_wait_for_accept() or sctp_wait_for_packet().
 693                  * For a UDP-style socket, the waiters are woken up by the
 694                  * notifications.
 695                  */
 696                 if (!sctp_style(sk, UDP))
 697                         sk->sk_state_change(sk);
 698         }
 699 }
 700
 701 /* Helper function to delete an association. */
 702 static void sctp_cmd_delete_tcb(sctp_cmd_seq_t *cmds,
 703                                 struct sctp_association *asoc)
 704 {
 705         struct sock *sk = asoc->base.sk;
 706
 707         /* If it is a non-temporary association belonging to a TCP-style
 708          * listening socket that is not closed, do not free it so that accept()
 709          * can pick it up later.
 710          */
 711         if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
 712             (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
 713                 return;
 714
 715         sctp_unhash_established(asoc);
 716         sctp_association_free(asoc);
 717 }
 718
 719 /*
 720  * ADDIP Section 4.1 ASCONF Chunk Procedures
 721  * A4) Start a T-4 RTO timer, using the RTO value of the selected
 722  * destination address (we use active path instead of primary path just
 723  * because primary path may be inactive.
 724  */
 725 static void sctp_cmd_setup_t4(sctp_cmd_seq_t *cmds,
 726                                 struct sctp_association *asoc,
 727                                 struct sctp_chunk *chunk)
 728 {
 729         struct sctp_transport *t;
 730
 731         t = asoc->peer.active_path;
 732         asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
 733         chunk->transport = t;
 734 }
 735
 736 /* Process an incoming Operation Error Chunk. */
 737 static void sctp_cmd_process_operr(sctp_cmd_seq_t *cmds,
 738                                    struct sctp_association *asoc,
 739                                    struct sctp_chunk *chunk)
 740 {
 741         struct sctp_operr_chunk *operr_chunk;
 742         struct sctp_errhdr *err_hdr;
 743
 744         operr_chunk = (struct sctp_operr_chunk *)chunk->chunk_hdr;
 745         err_hdr = &operr_chunk->err_hdr;
 746
 747         switch (err_hdr->cause) {
 748         case SCTP_ERROR_UNKNOWN_CHUNK:
 749         {
 750                 struct sctp_chunkhdr *unk_chunk_hdr;
 751
 752                 unk_chunk_hdr = (struct sctp_chunkhdr *)err_hdr->variable;
 753                 switch (unk_chunk_hdr->type) {
 754                 /* ADDIP 4.1 A9) If the peer responds to an ASCONF with an
 755                  * ERROR chunk reporting that it did not recognized the ASCONF
 756                  * chunk type, the sender of the ASCONF MUST NOT send any
 757                  * further ASCONF chunks and MUST stop its T-4 timer.
 758                  */
 759                 case SCTP_CID_ASCONF:
 760                         asoc->peer.asconf_capable = 0;
 761                         sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
 762                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
 763                         break;
 764                 default:
 765                         break;
 766                 }
 767                 break;
 768         }
 769         default:
 770                 break;
 771         }
 772 }
 773
 774 /* Process variable FWDTSN chunk information. */
 775 static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq,
 776                                     struct sctp_chunk *chunk)
 777 {
 778         struct sctp_fwdtsn_skip *skip;
 779         /* Walk through all the skipped SSNs */
 780         sctp_walk_fwdtsn(skip, chunk) {
 781                 sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
 782         }
 783
 784         return;
 785 }
 786
 787 /* Helper function to remove the association non-primary peer
 788  * transports.
 789  */
 790 static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
 791 {
 792         struct sctp_transport *t;
 793         struct list_head *pos;
 794         struct list_head *temp;
 795
 796         list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
 797                 t = list_entry(pos, struct sctp_transport, transports);
 798                 if (!sctp_cmp_addr_exact(&t->ipaddr,
 799                                          &asoc->peer.primary_addr)) {
 800                         sctp_assoc_del_peer(asoc, &t->ipaddr);
 801                 }
 802         }
 803
 804         return;
 805 }
 806
 807 /* These three macros allow us to pull the debugging code out of the
 808  * main flow of sctp_do_sm() to keep attention focused on the real
 809  * functionality there.
 810  */
 811 #define DEBUG_PRE \
 812         SCTP_DEBUG_PRINTK("sctp_do_sm prefn: " \
 813                           "ep %p, %s, %s, asoc %p[%s], %s\n", \
 814                           ep, sctp_evttype_tbl[event_type], \
 815                           (*debug_fn)(subtype), asoc, \
 816                           sctp_state_tbl[state], state_fn->name)
 817
 818 #define DEBUG_POST \
 819         SCTP_DEBUG_PRINTK("sctp_do_sm postfn: " \
 820                           "asoc %p, status: %s\n", \
 821                           asoc, sctp_status_tbl[status])
 822
 823 #define DEBUG_POST_SFX \
 824         SCTP_DEBUG_PRINTK("sctp_do_sm post sfx: error %d, asoc %p[%s]\n", \
 825                           error, asoc, \
 826                           sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
 827                           sctp_assoc2id(asoc)))?asoc->state:SCTP_STATE_CLOSED])
 828
 829 /*
 830  * This is the master state machine processing function.
 831  *
 832  * If you want to understand all of lksctp, this is a
 833  * good place to start.
 834  */
 835 int sctp_do_sm(sctp_event_t event_type, sctp_subtype_t subtype,
 836                sctp_state_t state,
 837                struct sctp_endpoint *ep,
 838                struct sctp_association *asoc,
 839                void *event_arg,
 840                int gfp)
 841 {
 842         sctp_cmd_seq_t commands;
 843         const sctp_sm_table_entry_t *state_fn;
 844         sctp_disposition_t status;
 845         int error = 0;
 846         typedef const char *(printfn_t)(sctp_subtype_t);
 847
 848         static printfn_t *table[] = {
 849                 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
 850         };
 851         printfn_t *debug_fn  __attribute__ ((unused)) = table[event_type];
 852
 853         /* Look up the state function, run it, and then process the
 854          * side effects.  These three steps are the heart of lksctp.
 855          */
 856         state_fn = sctp_sm_lookup_event(event_type, state, subtype);
 857
 858         sctp_init_cmd_seq(&commands);
 859
 860         DEBUG_PRE;
 861         status = (*state_fn->fn)(ep, asoc, subtype, event_arg, &commands);
 862         DEBUG_POST;
 863
 864         error = sctp_side_effects(event_type, subtype, state,
 865                                   ep, asoc, event_arg, status,
 866                                   &commands, gfp);
 867         DEBUG_POST_SFX;
 868
 869         return error;
 870 }
 871
 872 #undef DEBUG_PRE
 873 #undef DEBUG_POST
 874
 875 /*****************************************************************
 876  * This the master state function side effect processing function.
 877  *****************************************************************/
 878 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
 879                              sctp_state_t state,
 880                              struct sctp_endpoint *ep,
 881                              struct sctp_association *asoc,
 882                              void *event_arg,
 883                              sctp_disposition_t status,
 884                              sctp_cmd_seq_t *commands,
 885                              int gfp)
 886 {
 887         int error;
 888
 889         /* FIXME - Most of the dispositions left today would be categorized
 890          * as "exceptional" dispositions.  For those dispositions, it
 891          * may not be proper to run through any of the commands at all.
 892          * For example, the command interpreter might be run only with
 893          * disposition SCTP_DISPOSITION_CONSUME.
 894          */
 895         if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
 896                                                ep, asoc,
 897                                                event_arg, status,
 898                                                commands, gfp)))
 899                 goto bail;
 900
 901         switch (status) {
 902         case SCTP_DISPOSITION_DISCARD:
 903                 SCTP_DEBUG_PRINTK("Ignored sctp protocol event - state %d, "
 904                                   "event_type %d, event_id %d\n",
 905                                   state, event_type, subtype.chunk);
 906                 break;
 907
 908         case SCTP_DISPOSITION_NOMEM:
 909                 /* We ran out of memory, so we need to discard this
 910                  * packet.
 911                  */
 912                 /* BUG--we should now recover some memory, probably by
 913                  * reneging...
 914                  */
 915                 error = -ENOMEM;
 916                 break;
 917
 918         case SCTP_DISPOSITION_DELETE_TCB:
 919                 /* This should now be a command. */
 920                 break;
 921
 922         case SCTP_DISPOSITION_CONSUME:
 923         case SCTP_DISPOSITION_ABORT:
 924                 /*
 925                  * We should no longer have much work to do here as the
 926                  * real work has been done as explicit commands above.
 927                  */
 928                 break;
 929
 930         case SCTP_DISPOSITION_VIOLATION:
 931                 printk(KERN_ERR "sctp protocol violation state %d "
 932                        "chunkid %d\n", state, subtype.chunk);
 933                 break;
 934
 935         case SCTP_DISPOSITION_NOT_IMPL:
 936                 printk(KERN_WARNING "sctp unimplemented feature in state %d, "
 937                        "event_type %d, event_id %d\n",
 938                        state, event_type, subtype.chunk);
 939                 break;
 940
 941         case SCTP_DISPOSITION_BUG:
 942                 printk(KERN_ERR "sctp bug in state %d, "
 943                        "event_type %d, event_id %d\n",
 944                        state, event_type, subtype.chunk);
 945                 BUG();
 946                 break;
 947
 948         default:
 949                 printk(KERN_ERR "sctp impossible disposition %d "
 950                        "in state %d, event_type %d, event_id %d\n",
 951                        status, state, event_type, subtype.chunk);
 952                 BUG();
 953                 break;
 954         };
 955
 956 bail:
 957         return error;
 958 }
 959
 960 /********************************************************************
 961  * 2nd Level Abstractions
 962  ********************************************************************/
 963
 964 /* This is the side-effect interpreter.  */
 965 static int sctp_cmd_interpreter(sctp_event_t event_type,
 966                                 sctp_subtype_t subtype,
 967                                 sctp_state_t state,
 968                                 struct sctp_endpoint *ep,
 969                                 struct sctp_association *asoc,
 970                                 void *event_arg,
 971                                 sctp_disposition_t status,
 972                                 sctp_cmd_seq_t *commands,
 973                                 int gfp)
 974 {
 975         int error = 0;
 976         int force;
 977         sctp_cmd_t *cmd;
 978         struct sctp_chunk *new_obj;
 979         struct sctp_chunk *chunk = NULL;
 980         struct sctp_packet *packet;
 981         struct list_head *pos;
 982         struct timer_list *timer;
 983         unsigned long timeout;
 984         struct sctp_transport *t;
 985         struct sctp_sackhdr sackh;
 986         int local_cork = 0;
 987
 988         if (SCTP_EVENT_T_TIMEOUT != event_type)
 989                 chunk = (struct sctp_chunk *) event_arg;
 990
 991         /* Note:  This whole file is a huge candidate for rework.
 992          * For example, each command could either have its own handler, so
 993          * the loop would look like:
 994          *     while (cmds)
 995          *         cmd->handle(x, y, z)
 996          * --jgrimm
 997          */
 998         while (NULL != (cmd = sctp_next_cmd(commands))) {
 999                 switch (cmd->verb) {
1000                 case SCTP_CMD_NOP:
1001                         /* Do nothing. */
1002                         break;
1003
1004                 case SCTP_CMD_NEW_ASOC:
1005                         /* Register a new association.  */
1006                         if (local_cork) {
1007                                 sctp_outq_uncork(&asoc->outqueue);
1008                                 local_cork = 0;
1009                         }
1010                         asoc = cmd->obj.ptr;
1011                         /* Register with the endpoint.  */
1012                         sctp_endpoint_add_asoc(ep, asoc);
1013                         sctp_hash_established(asoc);
1014                         break;
1015
1016                 case SCTP_CMD_UPDATE_ASSOC:
1017                        sctp_assoc_update(asoc, cmd->obj.ptr);
1018                        break;
1019
1020                 case SCTP_CMD_PURGE_OUTQUEUE:
1021                        sctp_outq_teardown(&asoc->outqueue);
1022                        break;
1023
1024                 case SCTP_CMD_DELETE_TCB:
1025                         if (local_cork) {
1026                                 sctp_outq_uncork(&asoc->outqueue);
1027                                 local_cork = 0;
1028                         }
1029                         /* Delete the current association.  */
1030                         sctp_cmd_delete_tcb(commands, asoc);
1031                         asoc = NULL;
1032                         break;
1033
1034                 case SCTP_CMD_NEW_STATE:
1035                         /* Enter a new state.  */
1036                         sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1037                         break;
1038
1039                 case SCTP_CMD_REPORT_TSN:
1040                         /* Record the arrival of a TSN.  */
1041                         sctp_tsnmap_mark(&asoc->peer.tsn_map, cmd->obj.u32);
1042                         break;
1043
1044                 case SCTP_CMD_REPORT_FWDTSN:
1045                         /* Move the Cumulattive TSN Ack ahead. */
1046                         sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32);
1047
1048                         /* Abort any in progress partial delivery. */
1049                         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
1050                         break;
1051
1052                 case SCTP_CMD_PROCESS_FWDTSN:
1053                         sctp_cmd_process_fwdtsn(&asoc->ulpq, cmd->obj.ptr);
1054                         break;
1055
1056                 case SCTP_CMD_GEN_SACK:
1057                         /* Generate a Selective ACK.
1058                          * The argument tells us whether to just count
1059                          * the packet and MAYBE generate a SACK, or
1060                          * force a SACK out.
1061                          */
1062                         force = cmd->obj.i32;
1063                         error = sctp_gen_sack(asoc, force, commands);
1064                         break;
1065
1066                 case SCTP_CMD_PROCESS_SACK:
1067                         /* Process an inbound SACK.  */
1068                         error = sctp_cmd_process_sack(commands, asoc,
1069                                                       cmd->obj.ptr);
1070                         break;
1071
1072                 case SCTP_CMD_GEN_INIT_ACK:
1073                         /* Generate an INIT ACK chunk.  */
1074                         new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1075                                                      0);
1076                         if (!new_obj)
1077                                 goto nomem;
1078
1079                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1080                                         SCTP_CHUNK(new_obj));
1081                         break;
1082
1083                 case SCTP_CMD_PEER_INIT:
1084                         /* Process a unified INIT from the peer.
1085                          * Note: Only used during INIT-ACK processing.  If
1086                          * there is an error just return to the outter
1087                          * layer which will bail.
1088                          */
1089                         error = sctp_cmd_process_init(commands, asoc, chunk,
1090                                                       cmd->obj.ptr, gfp);
1091                         break;
1092
1093                 case SCTP_CMD_GEN_COOKIE_ECHO:
1094                         /* Generate a COOKIE ECHO chunk.  */
1095                         new_obj = sctp_make_cookie_echo(asoc, chunk);
1096                         if (!new_obj) {
1097                                 if (cmd->obj.ptr)
1098                                         sctp_chunk_free(cmd->obj.ptr);
1099                                 goto nomem;
1100                         }
1101                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1102                                         SCTP_CHUNK(new_obj));
1103
1104                         /* If there is an ERROR chunk to be sent along with
1105                          * the COOKIE_ECHO, send it, too.
1106                          */
1107                         if (cmd->obj.ptr)
1108                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1109                                                 SCTP_CHUNK(cmd->obj.ptr));
1110
1111                         /* FIXME - Eventually come up with a cleaner way to
1112                          * enabling COOKIE-ECHO + DATA bundling during
1113                          * multihoming stale cookie scenarios, the following
1114                          * command plays with asoc->peer.retran_path to
1115                          * avoid the problem of sending the COOKIE-ECHO and
1116                          * DATA in different paths, which could result
1117                          * in the association being ABORTed if the DATA chunk
1118                          * is processed first by the server.  Checking the
1119                          * init error counter simply causes this command
1120                          * to be executed only during failed attempts of
1121                          * association establishment.
1122                          */
1123                         if ((asoc->peer.retran_path !=
1124                              asoc->peer.primary_path) &&
1125                             (asoc->counters[SCTP_COUNTER_INIT_ERROR] > 0)) {
1126                                 sctp_add_cmd_sf(commands,
1127                                                 SCTP_CMD_FORCE_PRIM_RETRAN,
1128                                                 SCTP_NULL());
1129                         }
1130
1131                         break;
1132
1133                 case SCTP_CMD_GEN_SHUTDOWN:
1134                         /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1135                          * Reset error counts.
1136                          */
1137                         asoc->overall_error_count = 0;
1138
1139                         /* Generate a SHUTDOWN chunk.  */
1140                         new_obj = sctp_make_shutdown(asoc, chunk);
1141                         if (!new_obj)
1142                                 goto nomem;
1143                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1144                                         SCTP_CHUNK(new_obj));
1145                         break;
1146
1147                 case SCTP_CMD_CHUNK_ULP:
1148                         /* Send a chunk to the sockets layer.  */
1149                         SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1150                                           "chunk_up:", cmd->obj.ptr,
1151                                           "ulpq:", &asoc->ulpq);
1152                         sctp_ulpq_tail_data(&asoc->ulpq, cmd->obj.ptr,
1153                                             GFP_ATOMIC);
1154                         break;
1155
1156                 case SCTP_CMD_EVENT_ULP:
1157                         /* Send a notification to the sockets layer.  */
1158                         SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1159                                           "event_up:",cmd->obj.ptr,
1160                                           "ulpq:",&asoc->ulpq);
1161                         sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ptr);
1162                         break;
1163
1164                 case SCTP_CMD_REPLY:
1165                         /* If an caller has not already corked, do cork. */
1166                         if (!asoc->outqueue.cork) {
1167                                 sctp_outq_cork(&asoc->outqueue);
1168                                 local_cork = 1;
1169                         }
1170                         /* Send a chunk to our peer.  */
1171                         error = sctp_outq_tail(&asoc->outqueue, cmd->obj.ptr);
1172                         break;
1173
1174                 case SCTP_CMD_SEND_PKT:
1175                         /* Send a full packet to our peer.  */
1176                         packet = cmd->obj.ptr;
1177                         sctp_packet_transmit(packet);
1178                         sctp_ootb_pkt_free(packet);
1179                         break;
1180
1181                 case SCTP_CMD_RETRAN:
1182                         /* Mark a transport for retransmission.  */
1183                         sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1184                                         SCTP_RTXR_T3_RTX);
1185                         break;
1186
1187                 case SCTP_CMD_TRANSMIT:
1188                         /* Kick start transmission. */
1189                         error = sctp_outq_uncork(&asoc->outqueue);
1190                         local_cork = 0;
1191                         break;
1192
1193                 case SCTP_CMD_ECN_CE:
1194                         /* Do delayed CE processing.   */
1195                         sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1196                         break;
1197
1198                 case SCTP_CMD_ECN_ECNE:
1199                         /* Do delayed ECNE processing. */
1200                         new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1201                                                         chunk);
1202                         if (new_obj)
1203                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1204                                                 SCTP_CHUNK(new_obj));
1205                         break;
1206
1207                 case SCTP_CMD_ECN_CWR:
1208                         /* Do delayed CWR processing.  */
1209                         sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1210                         break;
1211
1212                 case SCTP_CMD_SETUP_T2:
1213                         sctp_cmd_setup_t2(commands, asoc, cmd->obj.ptr);
1214                         break;
1215
1216                 case SCTP_CMD_TIMER_START:
1217                         timer = &asoc->timers[cmd->obj.to];
1218                         timeout = asoc->timeouts[cmd->obj.to];
1219                         if (!timeout)
1220                                 BUG();
1221
1222                         timer->expires = jiffies + timeout;
1223                         sctp_association_hold(asoc);
1224                         add_timer(timer);
1225                         break;
1226
1227                 case SCTP_CMD_TIMER_RESTART:
1228                         timer = &asoc->timers[cmd->obj.to];
1229                         timeout = asoc->timeouts[cmd->obj.to];
1230                         if (!mod_timer(timer, jiffies + timeout))
1231                                 sctp_association_hold(asoc);
1232                         break;
1233
1234                 case SCTP_CMD_TIMER_STOP:
1235                         timer = &asoc->timers[cmd->obj.to];
1236                         if (timer_pending(timer) && del_timer(timer))
1237                                 sctp_association_put(asoc);
1238                         break;
1239
1240                 case SCTP_CMD_INIT_RESTART:
1241                         /* Do the needed accounting and updates
1242                          * associated with restarting an initialization
1243                          * timer.
1244                          */
1245                         asoc->counters[SCTP_COUNTER_INIT_ERROR]++;
1246                         asoc->timeouts[cmd->obj.to] *= 2;
1247                         if (asoc->timeouts[cmd->obj.to] >
1248                             asoc->max_init_timeo) {
1249                                 asoc->timeouts[cmd->obj.to] =
1250                                         asoc->max_init_timeo;
1251                         }
1252
1253                         /* If we've sent any data bundled with
1254                          * COOKIE-ECHO we need to resend.
1255                          */
1256                         list_for_each(pos, &asoc->peer.transport_addr_list) {
1257                                 t = list_entry(pos, struct sctp_transport,
1258                                                transports);
1259                                 sctp_retransmit_mark(&asoc->outqueue, t, 0);
1260                         }
1261
1262                         sctp_add_cmd_sf(commands,
1263                                         SCTP_CMD_TIMER_RESTART,
1264                                         SCTP_TO(cmd->obj.to));
1265                         break;
1266
1267                 case SCTP_CMD_INIT_FAILED:
1268                         sctp_cmd_init_failed(commands, asoc, cmd->obj.u32);
1269                         break;
1270
1271                 case SCTP_CMD_ASSOC_FAILED:
1272                         sctp_cmd_assoc_failed(commands, asoc, event_type,
1273                                               subtype, chunk, cmd->obj.u32);
1274                         break;
1275
1276                 case SCTP_CMD_COUNTER_INC:
1277                         asoc->counters[cmd->obj.counter]++;
1278                         break;
1279
1280                 case SCTP_CMD_COUNTER_RESET:
1281                         asoc->counters[cmd->obj.counter] = 0;
1282                         break;
1283
1284                 case SCTP_CMD_REPORT_DUP:
1285                         sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1286                                              cmd->obj.u32);
1287                         break;
1288
1289                 case SCTP_CMD_REPORT_BAD_TAG:
1290                         SCTP_DEBUG_PRINTK("vtag mismatch!\n");
1291                         break;
1292
1293                 case SCTP_CMD_STRIKE:
1294                         /* Mark one strike against a transport.  */
1295                         sctp_do_8_2_transport_strike(asoc, cmd->obj.transport);
1296                         break;
1297
1298                 case SCTP_CMD_TRANSPORT_RESET:
1299                         t = cmd->obj.transport;
1300                         sctp_cmd_transport_reset(commands, asoc, t);
1301                         break;
1302
1303                 case SCTP_CMD_TRANSPORT_ON:
1304                         t = cmd->obj.transport;
1305                         sctp_cmd_transport_on(commands, asoc, t, chunk);
1306                         break;
1307
1308                 case SCTP_CMD_HB_TIMERS_START:
1309                         sctp_cmd_hb_timers_start(commands, asoc);
1310                         break;
1311
1312                 case SCTP_CMD_HB_TIMER_UPDATE:
1313                         t = cmd->obj.transport;
1314                         sctp_cmd_hb_timer_update(commands, asoc, t);
1315                         break;
1316
1317                 case SCTP_CMD_HB_TIMERS_STOP:
1318                         sctp_cmd_hb_timers_stop(commands, asoc);
1319                         break;
1320
1321                 case SCTP_CMD_REPORT_ERROR:
1322                         error = cmd->obj.error;
1323                         break;
1324
1325                 case SCTP_CMD_PROCESS_CTSN:
1326                         /* Dummy up a SACK for processing. */
1327                         sackh.cum_tsn_ack = cmd->obj.u32;
1328                         sackh.a_rwnd = 0;
1329                         sackh.num_gap_ack_blocks = 0;
1330                         sackh.num_dup_tsns = 0;
1331                         sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1332                                         SCTP_SACKH(&sackh));
1333                         break;
1334
1335                 case SCTP_CMD_DISCARD_PACKET:
1336                         /* We need to discard the whole packet.  */
1337                         chunk->pdiscard = 1;
1338                         break;
1339
1340                 case SCTP_CMD_RTO_PENDING:
1341                         t = cmd->obj.transport;
1342                         t->rto_pending = 1;
1343                         break;
1344
1345                 case SCTP_CMD_PART_DELIVER:
1346                         sctp_ulpq_partial_delivery(&asoc->ulpq, cmd->obj.ptr,
1347                                                    GFP_ATOMIC);
1348                         break;
1349
1350                 case SCTP_CMD_RENEGE:
1351                         sctp_ulpq_renege(&asoc->ulpq, cmd->obj.ptr,
1352                                          GFP_ATOMIC);
1353                         break;
1354
1355                 case SCTP_CMD_SETUP_T4:
1356                         sctp_cmd_setup_t4(commands, asoc, cmd->obj.ptr);
1357                         break;
1358
1359                 case SCTP_CMD_PROCESS_OPERR:
1360                         sctp_cmd_process_operr(commands, asoc, chunk);
1361                         break;
1362                 case SCTP_CMD_CLEAR_INIT_TAG:
1363                         asoc->peer.i.init_tag = 0;
1364                         break;
1365                 case SCTP_CMD_DEL_NON_PRIMARY:
1366                         sctp_cmd_del_non_primary(asoc);
1367                         break;
1368                 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1369                         sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1370                         break;
1371                 case SCTP_CMD_FORCE_PRIM_RETRAN:
1372                         t = asoc->peer.retran_path;
1373                         asoc->peer.retran_path = asoc->peer.primary_path;
1374                         error = sctp_outq_uncork(&asoc->outqueue);
1375                         local_cork = 0;
1376                         asoc->peer.retran_path = t;
1377                         break;
1378                 default:
1379                         printk(KERN_WARNING "Impossible command: %u, %p\n",
1380                                cmd->verb, cmd->obj.ptr);
1381                         break;
1382                 };
1383                 if (error)
1384                         break;
1385         }
1386
1387 out:
1388         if (local_cork)
1389                 sctp_outq_uncork(&asoc->outqueue);
1390         return error;
1391 nomem:
1392         error = -ENOMEM;
1393         goto out;
1394 }
1395