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->state != SCTP_INACTIVE &&
 418             (transport->error_count++ >= transport->max_retrans)) {
 419                 SCTP_DEBUG_PRINTK_IPADDR("transport_strike:association %p",
 420                                          " transport IP: port:%d failed.\n",
 421                                          asoc,
 422                                          (&transport->ipaddr),
 423                                          transport->ipaddr.v4.sin_port);
 424                 sctp_assoc_control_transport(asoc, transport,
 425                                              SCTP_TRANSPORT_DOWN,
 426                                              SCTP_FAILED_THRESHOLD);
 427         }
 428
 429         /* E2) For the destination address for which the timer
 430          * expires, set RTO <- RTO * 2 ("back off the timer").  The
 431          * maximum value discussed in rule C7 above (RTO.max) may be
 432          * used to provide an upper bound to this doubling operation.
 433          */
 434         transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
 435 }
 436
 437 /* Worker routine to handle INIT command failure.  */
 438 static void sctp_cmd_init_failed(sctp_cmd_seq_t *commands,
 439                                  struct sctp_association *asoc,
 440                                  unsigned error)
 441 {
 442         struct sctp_ulpevent *event;
 443
 444         event = sctp_ulpevent_make_assoc_change(asoc,0, SCTP_CANT_STR_ASSOC,
 445                                                 (__u16)error, 0, 0,
 446                                                 GFP_ATOMIC);
 447
 448         if (event)
 449                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 450                                 SCTP_ULPEVENT(event));
 451
 452         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 453                         SCTP_STATE(SCTP_STATE_CLOSED));
 454
 455         /* SEND_FAILED sent later when cleaning up the association. */
 456         asoc->outqueue.error = error;
 457         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 458 }
 459
 460 /* Worker routine to handle SCTP_CMD_ASSOC_FAILED.  */
 461 static void sctp_cmd_assoc_failed(sctp_cmd_seq_t *commands,
 462                                   struct sctp_association *asoc,
 463                                   sctp_event_t event_type,
 464                                   sctp_subtype_t subtype,
 465                                   struct sctp_chunk *chunk,
 466                                   unsigned error)
 467 {
 468         struct sctp_ulpevent *event;
 469
 470         /* Cancel any partial delivery in progress. */
 471         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
 472
 473         event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
 474                                                 (__u16)error, 0, 0,
 475                                                 GFP_ATOMIC);
 476         if (event)
 477                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 478                                 SCTP_ULPEVENT(event));
 479
 480         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 481                         SCTP_STATE(SCTP_STATE_CLOSED));
 482
 483         /* Set sk_err to ECONNRESET on a 1-1 style socket. */
 484         if (!sctp_style(asoc->base.sk, UDP))
 485                 asoc->base.sk->sk_err = ECONNRESET;
 486
 487         /* SEND_FAILED sent later when cleaning up the association. */
 488         asoc->outqueue.error = error;
 489         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 490 }
 491
 492 /* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
 493  * inside the cookie.  In reality, this is only used for INIT-ACK processing
 494  * since all other cases use "temporary" associations and can do all
 495  * their work in statefuns directly.
 496  */
 497 static int sctp_cmd_process_init(sctp_cmd_seq_t *commands,
 498                                  struct sctp_association *asoc,
 499                                  struct sctp_chunk *chunk,
 500                                  sctp_init_chunk_t *peer_init, int gfp)
 501 {
 502         int error;
 503
 504         /* We only process the init as a sideeffect in a single
 505          * case.   This is when we process the INIT-ACK.   If we
 506          * fail during INIT processing (due to malloc problems),
 507          * just return the error and stop processing the stack.
 508          */
 509         if (!sctp_process_init(asoc, chunk->chunk_hdr->type,
 510                                sctp_source(chunk), peer_init, gfp))
 511                 error = -ENOMEM;
 512         else
 513                 error = 0;
 514
 515         return error;
 516 }
 517
 518 /* Helper function to break out starting up of heartbeat timers.  */
 519 static void sctp_cmd_hb_timers_start(sctp_cmd_seq_t *cmds,
 520                                      struct sctp_association *asoc)
 521 {
 522         struct sctp_transport *t;
 523         struct list_head *pos;
 524
 525         /* Start a heartbeat timer for each transport on the association.
 526          * hold a reference on the transport to make sure none of
 527          * the needed data structures go away.
 528          */
 529         list_for_each(pos, &asoc->peer.transport_addr_list) {
 530                 t = list_entry(pos, struct sctp_transport, transports);
 531
 532                 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 533                         sctp_transport_hold(t);
 534         }
 535 }
 536
 537 static void sctp_cmd_hb_timers_stop(sctp_cmd_seq_t *cmds,
 538                                     struct sctp_association *asoc)
 539 {
 540         struct sctp_transport *t;
 541         struct list_head *pos;
 542
 543         /* Stop all heartbeat timers. */
 544
 545         list_for_each(pos, &asoc->peer.transport_addr_list) {
 546                 t = list_entry(pos, struct sctp_transport, transports);
 547                 if (del_timer(&t->hb_timer))
 548                         sctp_transport_put(t);
 549         }
 550 }
 551
 552 /* Helper function to stop any pending T3-RTX timers */
 553 static void sctp_cmd_t3_rtx_timers_stop(sctp_cmd_seq_t *cmds,
 554                                         struct sctp_association *asoc)
 555 {
 556         struct sctp_transport *t;
 557         struct list_head *pos;
 558
 559         list_for_each(pos, &asoc->peer.transport_addr_list) {
 560                 t = list_entry(pos, struct sctp_transport, transports);
 561                 if (timer_pending(&t->T3_rtx_timer) &&
 562                     del_timer(&t->T3_rtx_timer)) {
 563                         sctp_transport_put(t);
 564                 }
 565         }
 566 }
 567
 568
 569 /* Helper function to update the heartbeat timer. */
 570 static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
 571                                      struct sctp_association *asoc,
 572                                      struct sctp_transport *t)
 573 {
 574         /* Update the heartbeat timer.  */
 575         if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 576                 sctp_transport_hold(t);
 577 }
 578
 579 /* Helper function to handle the reception of an HEARTBEAT ACK.  */
 580 static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds,
 581                                   struct sctp_association *asoc,
 582                                   struct sctp_transport *t,
 583                                   struct sctp_chunk *chunk)
 584 {
 585         sctp_sender_hb_info_t *hbinfo;
 586
 587         /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
 588          * HEARTBEAT should clear the error counter of the destination
 589          * transport address to which the HEARTBEAT was sent.
 590          * The association's overall error count is also cleared.
 591          */
 592         t->error_count = 0;
 593         t->asoc->overall_error_count = 0;
 594
 595         /* Mark the destination transport address as active if it is not so
 596          * marked.
 597          */
 598         if (t->state == SCTP_INACTIVE)
 599                 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
 600                                              SCTP_HEARTBEAT_SUCCESS);
 601
 602         /* The receiver of the HEARTBEAT ACK should also perform an
 603          * RTT measurement for that destination transport address
 604          * using the time value carried in the HEARTBEAT ACK chunk.
 605          */
 606         hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
 607         sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
 608 }
 609
 610 /* Helper function to do a transport reset at the expiry of the hearbeat
 611  * timer.
 612  */
 613 static void sctp_cmd_transport_reset(sctp_cmd_seq_t *cmds,
 614                                      struct sctp_association *asoc,
 615                                      struct sctp_transport *t)
 616 {
 617         sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
 618
 619         /* Mark one strike against a transport.  */
 620         sctp_do_8_2_transport_strike(asoc, t);
 621 }
 622
 623 /* Helper function to process the process SACK command.  */
 624 static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds,
 625                                  struct sctp_association *asoc,
 626                                  struct sctp_sackhdr *sackh)
 627 {
 628         int err;
 629
 630         if (sctp_outq_sack(&asoc->outqueue, sackh)) {
 631                 /* There are no more TSNs awaiting SACK.  */
 632                 err = sctp_do_sm(SCTP_EVENT_T_OTHER,
 633                                  SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
 634                                  asoc->state, asoc->ep, asoc, NULL,
 635                                  GFP_ATOMIC);
 636         } else {
 637                 /* Windows may have opened, so we need
 638                  * to check if we have DATA to transmit
 639                  */
 640                 err = sctp_outq_flush(&asoc->outqueue, 0);
 641         }
 642
 643         return err;
 644 }
 645
 646 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
 647  * the transport for a shutdown chunk.
 648  */
 649 static void sctp_cmd_setup_t2(sctp_cmd_seq_t *cmds,
 650                               struct sctp_association *asoc,
 651                               struct sctp_chunk *chunk)
 652 {
 653         struct sctp_transport *t;
 654
 655         t = sctp_assoc_choose_shutdown_transport(asoc);
 656         asoc->shutdown_last_sent_to = t;
 657         asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
 658         chunk->transport = t;
 659 }
 660
 661 /* Helper function to change the state of an association. */
 662 static void sctp_cmd_new_state(sctp_cmd_seq_t *cmds,
 663                                struct sctp_association *asoc,
 664                                sctp_state_t state)
 665 {
 666         struct sock *sk = asoc->base.sk;
 667
 668         asoc->state = state;
 669
 670         SCTP_DEBUG_PRINTK("sctp_cmd_new_state: asoc %p[%s]\n",
 671                           asoc, sctp_state_tbl[state]);
 672
 673         if (sctp_style(sk, TCP)) {
 674                 /* Change the sk->sk_state of a TCP-style socket that has
 675                  * sucessfully completed a connect() call.
 676                  */
 677                 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
 678                         sk->sk_state = SCTP_SS_ESTABLISHED;
 679
 680                 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
 681                 if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
 682                     sctp_sstate(sk, ESTABLISHED))
 683                         sk->sk_shutdown |= RCV_SHUTDOWN;
 684         }
 685
 686         if (sctp_state(asoc, COOKIE_WAIT)) {
 687                 /* Reset init timeouts since they may have been
 688                  * increased due to timer expirations.
 689                  */
 690                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
 691                         asoc->ep->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT];
 692                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
 693                         asoc->ep->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE];
 694         }
 695
 696         if (sctp_state(asoc, ESTABLISHED) ||
 697             sctp_state(asoc, CLOSED) ||
 698             sctp_state(asoc, SHUTDOWN_RECEIVED)) {
 699                 /* Wake up any processes waiting in the asoc's wait queue in
 700                  * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
 701                  */
 702                 if (waitqueue_active(&asoc->wait))
 703                         wake_up_interruptible(&asoc->wait);
 704
 705                 /* Wake up any processes waiting in the sk's sleep queue of
 706                  * a TCP-style or UDP-style peeled-off socket in
 707                  * sctp_wait_for_accept() or sctp_wait_for_packet().
 708                  * For a UDP-style socket, the waiters are woken up by the
 709                  * notifications.
 710                  */
 711                 if (!sctp_style(sk, UDP))
 712                         sk->sk_state_change(sk);
 713         }
 714 }
 715
 716 /* Helper function to delete an association. */
 717 static void sctp_cmd_delete_tcb(sctp_cmd_seq_t *cmds,
 718                                 struct sctp_association *asoc)
 719 {
 720         struct sock *sk = asoc->base.sk;
 721
 722         /* If it is a non-temporary association belonging to a TCP-style
 723          * listening socket that is not closed, do not free it so that accept()
 724          * can pick it up later.
 725          */
 726         if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
 727             (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
 728                 return;
 729
 730         sctp_unhash_established(asoc);
 731         sctp_association_free(asoc);
 732 }
 733
 734 /*
 735  * ADDIP Section 4.1 ASCONF Chunk Procedures
 736  * A4) Start a T-4 RTO timer, using the RTO value of the selected
 737  * destination address (we use active path instead of primary path just
 738  * because primary path may be inactive.
 739  */
 740 static void sctp_cmd_setup_t4(sctp_cmd_seq_t *cmds,
 741                                 struct sctp_association *asoc,
 742                                 struct sctp_chunk *chunk)
 743 {
 744         struct sctp_transport *t;
 745
 746         t = asoc->peer.active_path;
 747         asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
 748         chunk->transport = t;
 749 }
 750
 751 /* Process an incoming Operation Error Chunk. */
 752 static void sctp_cmd_process_operr(sctp_cmd_seq_t *cmds,
 753                                    struct sctp_association *asoc,
 754                                    struct sctp_chunk *chunk)
 755 {
 756         struct sctp_operr_chunk *operr_chunk;
 757         struct sctp_errhdr *err_hdr;
 758
 759         operr_chunk = (struct sctp_operr_chunk *)chunk->chunk_hdr;
 760         err_hdr = &operr_chunk->err_hdr;
 761
 762         switch (err_hdr->cause) {
 763         case SCTP_ERROR_UNKNOWN_CHUNK:
 764         {
 765                 struct sctp_chunkhdr *unk_chunk_hdr;
 766
 767                 unk_chunk_hdr = (struct sctp_chunkhdr *)err_hdr->variable;
 768                 switch (unk_chunk_hdr->type) {
 769                 /* ADDIP 4.1 A9) If the peer responds to an ASCONF with an
 770                  * ERROR chunk reporting that it did not recognized the ASCONF
 771                  * chunk type, the sender of the ASCONF MUST NOT send any
 772                  * further ASCONF chunks and MUST stop its T-4 timer.
 773                  */
 774                 case SCTP_CID_ASCONF:
 775                         asoc->peer.asconf_capable = 0;
 776                         sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
 777                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
 778                         break;
 779                 default:
 780                         break;
 781                 }
 782                 break;
 783         }
 784         default:
 785                 break;
 786         }
 787 }
 788
 789 /* Process variable FWDTSN chunk information. */
 790 static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq,
 791                                     struct sctp_chunk *chunk)
 792 {
 793         struct sctp_fwdtsn_skip *skip;
 794         /* Walk through all the skipped SSNs */
 795         sctp_walk_fwdtsn(skip, chunk) {
 796                 sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
 797         }
 798
 799         return;
 800 }
 801
 802 /* Helper function to remove the association non-primary peer
 803  * transports.
 804  */
 805 static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
 806 {
 807         struct sctp_transport *t;
 808         struct list_head *pos;
 809         struct list_head *temp;
 810
 811         list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
 812                 t = list_entry(pos, struct sctp_transport, transports);
 813                 if (!sctp_cmp_addr_exact(&t->ipaddr,
 814                                          &asoc->peer.primary_addr)) {
 815                         sctp_assoc_del_peer(asoc, &t->ipaddr);
 816                 }
 817         }
 818
 819         return;
 820 }
 821
 822 /* These three macros allow us to pull the debugging code out of the
 823  * main flow of sctp_do_sm() to keep attention focused on the real
 824  * functionality there.
 825  */
 826 #define DEBUG_PRE \
 827         SCTP_DEBUG_PRINTK("sctp_do_sm prefn: " \
 828                           "ep %p, %s, %s, asoc %p[%s], %s\n", \
 829                           ep, sctp_evttype_tbl[event_type], \
 830                           (*debug_fn)(subtype), asoc, \
 831                           sctp_state_tbl[state], state_fn->name)
 832
 833 #define DEBUG_POST \
 834         SCTP_DEBUG_PRINTK("sctp_do_sm postfn: " \
 835                           "asoc %p, status: %s\n", \
 836                           asoc, sctp_status_tbl[status])
 837
 838 #define DEBUG_POST_SFX \
 839         SCTP_DEBUG_PRINTK("sctp_do_sm post sfx: error %d, asoc %p[%s]\n", \
 840                           error, asoc, \
 841                           sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
 842                           sctp_assoc2id(asoc)))?asoc->state:SCTP_STATE_CLOSED])
 843
 844 /*
 845  * This is the master state machine processing function.
 846  *
 847  * If you want to understand all of lksctp, this is a
 848  * good place to start.
 849  */
 850 int sctp_do_sm(sctp_event_t event_type, sctp_subtype_t subtype,
 851                sctp_state_t state,
 852                struct sctp_endpoint *ep,
 853                struct sctp_association *asoc,
 854                void *event_arg,
 855                int gfp)
 856 {
 857         sctp_cmd_seq_t commands;
 858         const sctp_sm_table_entry_t *state_fn;
 859         sctp_disposition_t status;
 860         int error = 0;
 861         typedef const char *(printfn_t)(sctp_subtype_t);
 862
 863         static printfn_t *table[] = {
 864                 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
 865         };
 866         printfn_t *debug_fn  __attribute__ ((unused)) = table[event_type];
 867
 868         /* Look up the state function, run it, and then process the
 869          * side effects.  These three steps are the heart of lksctp.
 870          */
 871         state_fn = sctp_sm_lookup_event(event_type, state, subtype);
 872
 873         sctp_init_cmd_seq(&commands);
 874
 875         DEBUG_PRE;
 876         status = (*state_fn->fn)(ep, asoc, subtype, event_arg, &commands);
 877         DEBUG_POST;
 878
 879         error = sctp_side_effects(event_type, subtype, state,
 880                                   ep, asoc, event_arg, status,
 881                                   &commands, gfp);
 882         DEBUG_POST_SFX;
 883
 884         return error;
 885 }
 886
 887 #undef DEBUG_PRE
 888 #undef DEBUG_POST
 889
 890 /*****************************************************************
 891  * This the master state function side effect processing function.
 892  *****************************************************************/
 893 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
 894                              sctp_state_t state,
 895                              struct sctp_endpoint *ep,
 896                              struct sctp_association *asoc,
 897                              void *event_arg,
 898                              sctp_disposition_t status,
 899                              sctp_cmd_seq_t *commands,
 900                              int gfp)
 901 {
 902         int error;
 903
 904         /* FIXME - Most of the dispositions left today would be categorized
 905          * as "exceptional" dispositions.  For those dispositions, it
 906          * may not be proper to run through any of the commands at all.
 907          * For example, the command interpreter might be run only with
 908          * disposition SCTP_DISPOSITION_CONSUME.
 909          */
 910         if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
 911                                                ep, asoc,
 912                                                event_arg, status,
 913                                                commands, gfp)))
 914                 goto bail;
 915
 916         switch (status) {
 917         case SCTP_DISPOSITION_DISCARD:
 918                 SCTP_DEBUG_PRINTK("Ignored sctp protocol event - state %d, "
 919                                   "event_type %d, event_id %d\n",
 920                                   state, event_type, subtype.chunk);
 921                 break;
 922
 923         case SCTP_DISPOSITION_NOMEM:
 924                 /* We ran out of memory, so we need to discard this
 925                  * packet.
 926                  */
 927                 /* BUG--we should now recover some memory, probably by
 928                  * reneging...
 929                  */
 930                 error = -ENOMEM;
 931                 break;
 932
 933         case SCTP_DISPOSITION_DELETE_TCB:
 934                 /* This should now be a command. */
 935                 break;
 936
 937         case SCTP_DISPOSITION_CONSUME:
 938         case SCTP_DISPOSITION_ABORT:
 939                 /*
 940                  * We should no longer have much work to do here as the
 941                  * real work has been done as explicit commands above.
 942                  */
 943                 break;
 944
 945         case SCTP_DISPOSITION_VIOLATION:
 946                 printk(KERN_ERR "sctp protocol violation state %d "
 947                        "chunkid %d\n", state, subtype.chunk);
 948                 break;
 949
 950         case SCTP_DISPOSITION_NOT_IMPL:
 951                 printk(KERN_WARNING "sctp unimplemented feature in state %d, "
 952                        "event_type %d, event_id %d\n",
 953                        state, event_type, subtype.chunk);
 954                 break;
 955
 956         case SCTP_DISPOSITION_BUG:
 957                 printk(KERN_ERR "sctp bug in state %d, "
 958                        "event_type %d, event_id %d\n",
 959                        state, event_type, subtype.chunk);
 960                 BUG();
 961                 break;
 962
 963         default:
 964                 printk(KERN_ERR "sctp impossible disposition %d "
 965                        "in state %d, event_type %d, event_id %d\n",
 966                        status, state, event_type, subtype.chunk);
 967                 BUG();
 968                 break;
 969         };
 970
 971 bail:
 972         return error;
 973 }
 974
 975 /********************************************************************
 976  * 2nd Level Abstractions
 977  ********************************************************************/
 978
 979 /* This is the side-effect interpreter.  */
 980 static int sctp_cmd_interpreter(sctp_event_t event_type,
 981                                 sctp_subtype_t subtype,
 982                                 sctp_state_t state,
 983                                 struct sctp_endpoint *ep,
 984                                 struct sctp_association *asoc,
 985                                 void *event_arg,
 986                                 sctp_disposition_t status,
 987                                 sctp_cmd_seq_t *commands,
 988                                 int gfp)
 989 {
 990         int error = 0;
 991         int force;
 992         sctp_cmd_t *cmd;
 993         struct sctp_chunk *new_obj;
 994         struct sctp_chunk *chunk = NULL;
 995         struct sctp_packet *packet;
 996         struct list_head *pos;
 997         struct timer_list *timer;
 998         unsigned long timeout;
 999         struct sctp_transport *t;
1000         struct sctp_sackhdr sackh;
1001         int local_cork = 0;
1002
1003         if (SCTP_EVENT_T_TIMEOUT != event_type)
1004                 chunk = (struct sctp_chunk *) event_arg;
1005
1006         /* Note:  This whole file is a huge candidate for rework.
1007          * For example, each command could either have its own handler, so
1008          * the loop would look like:
1009          *     while (cmds)
1010          *         cmd->handle(x, y, z)
1011          * --jgrimm
1012          */
1013         while (NULL != (cmd = sctp_next_cmd(commands))) {
1014                 switch (cmd->verb) {
1015                 case SCTP_CMD_NOP:
1016                         /* Do nothing. */
1017                         break;
1018
1019                 case SCTP_CMD_NEW_ASOC:
1020                         /* Register a new association.  */
1021                         if (local_cork) {
1022                                 sctp_outq_uncork(&asoc->outqueue);
1023                                 local_cork = 0;
1024                         }
1025                         asoc = cmd->obj.ptr;
1026                         /* Register with the endpoint.  */
1027                         sctp_endpoint_add_asoc(ep, asoc);
1028                         sctp_hash_established(asoc);
1029                         break;
1030
1031                 case SCTP_CMD_UPDATE_ASSOC:
1032                        sctp_assoc_update(asoc, cmd->obj.ptr);
1033                        break;
1034
1035                 case SCTP_CMD_PURGE_OUTQUEUE:
1036                        sctp_outq_teardown(&asoc->outqueue);
1037                        break;
1038
1039                 case SCTP_CMD_DELETE_TCB:
1040                         if (local_cork) {
1041                                 sctp_outq_uncork(&asoc->outqueue);
1042                                 local_cork = 0;
1043                         }
1044                         /* Delete the current association.  */
1045                         sctp_cmd_delete_tcb(commands, asoc);
1046                         asoc = NULL;
1047                         break;
1048
1049                 case SCTP_CMD_NEW_STATE:
1050                         /* Enter a new state.  */
1051                         sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1052                         break;
1053
1054                 case SCTP_CMD_REPORT_TSN:
1055                         /* Record the arrival of a TSN.  */
1056                         sctp_tsnmap_mark(&asoc->peer.tsn_map, cmd->obj.u32);
1057                         break;
1058
1059                 case SCTP_CMD_REPORT_FWDTSN:
1060                         /* Move the Cumulattive TSN Ack ahead. */
1061                         sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32);
1062
1063                         /* Abort any in progress partial delivery. */
1064                         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
1065                         break;
1066
1067                 case SCTP_CMD_PROCESS_FWDTSN:
1068                         sctp_cmd_process_fwdtsn(&asoc->ulpq, cmd->obj.ptr);
1069                         break;
1070
1071                 case SCTP_CMD_GEN_SACK:
1072                         /* Generate a Selective ACK.
1073                          * The argument tells us whether to just count
1074                          * the packet and MAYBE generate a SACK, or
1075                          * force a SACK out.
1076                          */
1077                         force = cmd->obj.i32;
1078                         error = sctp_gen_sack(asoc, force, commands);
1079                         break;
1080
1081                 case SCTP_CMD_PROCESS_SACK:
1082                         /* Process an inbound SACK.  */
1083                         error = sctp_cmd_process_sack(commands, asoc,
1084                                                       cmd->obj.ptr);
1085                         break;
1086
1087                 case SCTP_CMD_GEN_INIT_ACK:
1088                         /* Generate an INIT ACK chunk.  */
1089                         new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1090                                                      0);
1091                         if (!new_obj)
1092                                 goto nomem;
1093
1094                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1095                                         SCTP_CHUNK(new_obj));
1096                         break;
1097
1098                 case SCTP_CMD_PEER_INIT:
1099                         /* Process a unified INIT from the peer.
1100                          * Note: Only used during INIT-ACK processing.  If
1101                          * there is an error just return to the outter
1102                          * layer which will bail.
1103                          */
1104                         error = sctp_cmd_process_init(commands, asoc, chunk,
1105                                                       cmd->obj.ptr, gfp);
1106                         break;
1107
1108                 case SCTP_CMD_GEN_COOKIE_ECHO:
1109                         /* Generate a COOKIE ECHO chunk.  */
1110                         new_obj = sctp_make_cookie_echo(asoc, chunk);
1111                         if (!new_obj) {
1112                                 if (cmd->obj.ptr)
1113                                         sctp_chunk_free(cmd->obj.ptr);
1114                                 goto nomem;
1115                         }
1116                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1117                                         SCTP_CHUNK(new_obj));
1118
1119                         /* If there is an ERROR chunk to be sent along with
1120                          * the COOKIE_ECHO, send it, too.
1121                          */
1122                         if (cmd->obj.ptr)
1123                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1124                                                 SCTP_CHUNK(cmd->obj.ptr));
1125
1126                         /* FIXME - Eventually come up with a cleaner way to
1127                          * enabling COOKIE-ECHO + DATA bundling during
1128                          * multihoming stale cookie scenarios, the following
1129                          * command plays with asoc->peer.retran_path to
1130                          * avoid the problem of sending the COOKIE-ECHO and
1131                          * DATA in different paths, which could result
1132                          * in the association being ABORTed if the DATA chunk
1133                          * is processed first by the server.  Checking the
1134                          * init error counter simply causes this command
1135                          * to be executed only during failed attempts of
1136                          * association establishment.
1137                          */
1138                         if ((asoc->peer.retran_path !=
1139                              asoc->peer.primary_path) &&
1140                             (asoc->init_err_counter > 0)) {
1141                                 sctp_add_cmd_sf(commands,
1142                                                 SCTP_CMD_FORCE_PRIM_RETRAN,
1143                                                 SCTP_NULL());
1144                         }
1145
1146                         break;
1147
1148                 case SCTP_CMD_GEN_SHUTDOWN:
1149                         /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1150                          * Reset error counts.
1151                          */
1152                         asoc->overall_error_count = 0;
1153
1154                         /* Generate a SHUTDOWN chunk.  */
1155                         new_obj = sctp_make_shutdown(asoc, chunk);
1156                         if (!new_obj)
1157                                 goto nomem;
1158                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1159                                         SCTP_CHUNK(new_obj));
1160                         break;
1161
1162                 case SCTP_CMD_CHUNK_ULP:
1163                         /* Send a chunk to the sockets layer.  */
1164                         SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1165                                           "chunk_up:", cmd->obj.ptr,
1166                                           "ulpq:", &asoc->ulpq);
1167                         sctp_ulpq_tail_data(&asoc->ulpq, cmd->obj.ptr,
1168                                             GFP_ATOMIC);
1169                         break;
1170
1171                 case SCTP_CMD_EVENT_ULP:
1172                         /* Send a notification to the sockets layer.  */
1173                         SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1174                                           "event_up:",cmd->obj.ptr,
1175                                           "ulpq:",&asoc->ulpq);
1176                         sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ptr);
1177                         break;
1178
1179                 case SCTP_CMD_REPLY:
1180                         /* If an caller has not already corked, do cork. */
1181                         if (!asoc->outqueue.cork) {
1182                                 sctp_outq_cork(&asoc->outqueue);
1183                                 local_cork = 1;
1184                         }
1185                         /* Send a chunk to our peer.  */
1186                         error = sctp_outq_tail(&asoc->outqueue, cmd->obj.ptr);
1187                         break;
1188
1189                 case SCTP_CMD_SEND_PKT:
1190                         /* Send a full packet to our peer.  */
1191                         packet = cmd->obj.ptr;
1192                         sctp_packet_transmit(packet);
1193                         sctp_ootb_pkt_free(packet);
1194                         break;
1195
1196                 case SCTP_CMD_RETRAN:
1197                         /* Mark a transport for retransmission.  */
1198                         sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1199                                         SCTP_RTXR_T3_RTX);
1200                         break;
1201
1202                 case SCTP_CMD_TRANSMIT:
1203                         /* Kick start transmission. */
1204                         error = sctp_outq_uncork(&asoc->outqueue);
1205                         local_cork = 0;
1206                         break;
1207
1208                 case SCTP_CMD_ECN_CE:
1209                         /* Do delayed CE processing.   */
1210                         sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1211                         break;
1212
1213                 case SCTP_CMD_ECN_ECNE:
1214                         /* Do delayed ECNE processing. */
1215                         new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1216                                                         chunk);
1217                         if (new_obj)
1218                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1219                                                 SCTP_CHUNK(new_obj));
1220                         break;
1221
1222                 case SCTP_CMD_ECN_CWR:
1223                         /* Do delayed CWR processing.  */
1224                         sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1225                         break;
1226
1227                 case SCTP_CMD_SETUP_T2:
1228                         sctp_cmd_setup_t2(commands, asoc, cmd->obj.ptr);
1229                         break;
1230
1231                 case SCTP_CMD_TIMER_START:
1232                         timer = &asoc->timers[cmd->obj.to];
1233                         timeout = asoc->timeouts[cmd->obj.to];
1234                         if (!timeout)
1235                                 BUG();
1236
1237                         timer->expires = jiffies + timeout;
1238                         sctp_association_hold(asoc);
1239                         add_timer(timer);
1240                         break;
1241
1242                 case SCTP_CMD_TIMER_RESTART:
1243                         timer = &asoc->timers[cmd->obj.to];
1244                         timeout = asoc->timeouts[cmd->obj.to];
1245                         if (!mod_timer(timer, jiffies + timeout))
1246                                 sctp_association_hold(asoc);
1247                         break;
1248
1249                 case SCTP_CMD_TIMER_STOP:
1250                         timer = &asoc->timers[cmd->obj.to];
1251                         if (timer_pending(timer) && del_timer(timer))
1252                                 sctp_association_put(asoc);
1253                         break;
1254
1255                 case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1256                         chunk = cmd->obj.ptr;
1257                         t = sctp_assoc_choose_init_transport(asoc);
1258                         asoc->init_last_sent_to = t;
1259                         chunk->transport = t;
1260                         t->init_sent_count++;
1261                         break;
1262
1263                 case SCTP_CMD_INIT_RESTART:
1264                         /* Do the needed accounting and updates
1265                          * associated with restarting an initialization
1266                          * timer. Only multiply the timeout by two if
1267                          * all transports have been tried at the current
1268                          * timeout.
1269                          */
1270                         t = asoc->init_last_sent_to;
1271                         asoc->init_err_counter++;
1272
1273                         if (t->init_sent_count > (asoc->init_cycle + 1)) {
1274                                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] *= 2;
1275                                 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] >
1276                                     asoc->max_init_timeo) {
1277                                         asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
1278                                                 asoc->max_init_timeo;
1279                                 }
1280                                 asoc->init_cycle++;
1281                                 SCTP_DEBUG_PRINTK(
1282                                         "T1 INIT Timeout adjustment"
1283                                         " init_err_counter: %d"
1284                                         " cycle: %d"
1285                                         " timeout: %d\n",
1286                                         asoc->init_err_counter,
1287                                         asoc->init_cycle,
1288                                         asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT]);
1289                         }
1290
1291                         sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1292                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1293                         break;
1294
1295                 case SCTP_CMD_COOKIEECHO_RESTART:
1296                         /* Do the needed accounting and updates
1297                          * associated with restarting an initialization
1298                          * timer. Only multiply the timeout by two if
1299                          * all transports have been tried at the current
1300                          * timeout.
1301                          */
1302                         asoc->init_err_counter++;
1303
1304                         asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] *= 2;
1305                         if (asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] >
1306                             asoc->max_init_timeo) {
1307                                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
1308                                         asoc->max_init_timeo;
1309                         }
1310                         SCTP_DEBUG_PRINTK(
1311                                 "T1 COOKIE Timeout adjustment"
1312                                 " init_err_counter: %d"
1313                                 " timeout: %d\n",
1314                                 asoc->init_err_counter,
1315                                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE]);
1316
1317                         /* If we've sent any data bundled with
1318                          * COOKIE-ECHO we need to resend.
1319                          */
1320                         list_for_each(pos, &asoc->peer.transport_addr_list) {
1321                                 t = list_entry(pos, struct sctp_transport,
1322                                                transports);
1323                                 sctp_retransmit_mark(&asoc->outqueue, t, 0);
1324                         }
1325
1326                         sctp_add_cmd_sf(commands,
1327                                         SCTP_CMD_TIMER_RESTART,
1328                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1329                         break;
1330
1331                 case SCTP_CMD_INIT_FAILED:
1332                         sctp_cmd_init_failed(commands, asoc, cmd->obj.u32);
1333                         break;
1334
1335                 case SCTP_CMD_ASSOC_FAILED:
1336                         sctp_cmd_assoc_failed(commands, asoc, event_type,
1337                                               subtype, chunk, cmd->obj.u32);
1338                         break;
1339
1340                 case SCTP_CMD_INIT_COUNTER_INC:
1341                         asoc->init_err_counter++;
1342                         break;
1343
1344                 case SCTP_CMD_INIT_COUNTER_RESET:
1345                         asoc->init_err_counter = 0;
1346                         asoc->init_cycle = 0;
1347                         break;
1348
1349                 case SCTP_CMD_REPORT_DUP:
1350                         sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1351                                              cmd->obj.u32);
1352                         break;
1353
1354                 case SCTP_CMD_REPORT_BAD_TAG:
1355                         SCTP_DEBUG_PRINTK("vtag mismatch!\n");
1356                         break;
1357
1358                 case SCTP_CMD_STRIKE:
1359                         /* Mark one strike against a transport.  */
1360                         sctp_do_8_2_transport_strike(asoc, cmd->obj.transport);
1361                         break;
1362
1363                 case SCTP_CMD_TRANSPORT_RESET:
1364                         t = cmd->obj.transport;
1365                         sctp_cmd_transport_reset(commands, asoc, t);
1366                         break;
1367
1368                 case SCTP_CMD_TRANSPORT_ON:
1369                         t = cmd->obj.transport;
1370                         sctp_cmd_transport_on(commands, asoc, t, chunk);
1371                         break;
1372
1373                 case SCTP_CMD_HB_TIMERS_START:
1374                         sctp_cmd_hb_timers_start(commands, asoc);
1375                         break;
1376
1377                 case SCTP_CMD_HB_TIMER_UPDATE:
1378                         t = cmd->obj.transport;
1379                         sctp_cmd_hb_timer_update(commands, asoc, t);
1380                         break;
1381
1382                 case SCTP_CMD_HB_TIMERS_STOP:
1383                         sctp_cmd_hb_timers_stop(commands, asoc);
1384                         break;
1385
1386                 case SCTP_CMD_REPORT_ERROR:
1387                         error = cmd->obj.error;
1388                         break;
1389
1390                 case SCTP_CMD_PROCESS_CTSN:
1391                         /* Dummy up a SACK for processing. */
1392                         sackh.cum_tsn_ack = cmd->obj.u32;
1393                         sackh.a_rwnd = 0;
1394                         sackh.num_gap_ack_blocks = 0;
1395                         sackh.num_dup_tsns = 0;
1396                         sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1397                                         SCTP_SACKH(&sackh));
1398                         break;
1399
1400                 case SCTP_CMD_DISCARD_PACKET:
1401                         /* We need to discard the whole packet.  */
1402                         chunk->pdiscard = 1;
1403                         break;
1404
1405                 case SCTP_CMD_RTO_PENDING:
1406                         t = cmd->obj.transport;
1407                         t->rto_pending = 1;
1408                         break;
1409
1410                 case SCTP_CMD_PART_DELIVER:
1411                         sctp_ulpq_partial_delivery(&asoc->ulpq, cmd->obj.ptr,
1412                                                    GFP_ATOMIC);
1413                         break;
1414
1415                 case SCTP_CMD_RENEGE:
1416                         sctp_ulpq_renege(&asoc->ulpq, cmd->obj.ptr,
1417                                          GFP_ATOMIC);
1418                         break;
1419
1420                 case SCTP_CMD_SETUP_T4:
1421                         sctp_cmd_setup_t4(commands, asoc, cmd->obj.ptr);
1422                         break;
1423
1424                 case SCTP_CMD_PROCESS_OPERR:
1425                         sctp_cmd_process_operr(commands, asoc, chunk);
1426                         break;
1427                 case SCTP_CMD_CLEAR_INIT_TAG:
1428                         asoc->peer.i.init_tag = 0;
1429                         break;
1430                 case SCTP_CMD_DEL_NON_PRIMARY:
1431                         sctp_cmd_del_non_primary(asoc);
1432                         break;
1433                 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1434                         sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1435                         break;
1436                 case SCTP_CMD_FORCE_PRIM_RETRAN:
1437                         t = asoc->peer.retran_path;
1438                         asoc->peer.retran_path = asoc->peer.primary_path;
1439                         error = sctp_outq_uncork(&asoc->outqueue);
1440                         local_cork = 0;
1441                         asoc->peer.retran_path = t;
1442                         break;
1443                 default:
1444                         printk(KERN_WARNING "Impossible command: %u, %p\n",
1445                                cmd->verb, cmd->obj.ptr);
1446                         break;
1447                 };
1448                 if (error)
1449                         break;
1450         }
1451
1452 out:
1453         if (local_cork)
1454                 sctp_outq_uncork(&asoc->outqueue);
1455         return error;
1456 nomem:
1457         error = -ENOMEM;
1458         goto out;
1459 }
1460