net/sctp/sm_sideeffect.c

   1 /* SCTP kernel reference Implementation
   2  * (C) Copyright IBM Corp. 2001, 2004
   3  * Copyright (c) 1999 Cisco, Inc.
   4  * Copyright (c) 1999-2001 Motorola, Inc.
   5  *
   6  * This file is part of the SCTP kernel reference Implementation
   7  *
   8  * These functions work with the state functions in sctp_sm_statefuns.c
   9  * to implement that state operations.  These functions implement the
  10  * steps which require modifying existing data structures.
  11  *
  12  * The SCTP reference implementation is free software;
  13  * you can redistribute it and/or modify it under the terms of
  14  * the GNU General Public License as published by
  15  * the Free Software Foundation; either version 2, or (at your option)
  16  * any later version.
  17  *
  18  * The SCTP reference implementation is distributed in the hope that it
  19  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
  20  *                 ************************
  21  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  22  * See the GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with GNU CC; see the file COPYING.  If not, write to
  26  * the Free Software Foundation, 59 Temple Place - Suite 330,
  27  * Boston, MA 02111-1307, USA.
  28  *
  29  * Please send any bug reports or fixes you make to the
  30  * email address(es):
  31  *    lksctp developers <lksctp-developers@lists.sourceforge.net>
  32  *
  33  * Or submit a bug report through the following website:
  34  *    http://www.sf.net/projects/lksctp
  35  *
  36  * Written or modified by:
  37  *    La Monte H.P. Yarroll <piggy@acm.org>
  38  *    Karl Knutson          <karl@athena.chicago.il.us>
  39  *    Jon Grimm             <jgrimm@austin.ibm.com>
  40  *    Hui Huang             <hui.huang@nokia.com>
  41  *    Dajiang Zhang         <dajiang.zhang@nokia.com>
  42  *    Daisy Chang           <daisyc@us.ibm.com>
  43  *    Sridhar Samudrala     <sri@us.ibm.com>
  44  *    Ardelle Fan           <ardelle.fan@intel.com>
  45  *
  46  * Any bugs reported given to us we will try to fix... any fixes shared will
  47  * be incorporated into the next SCTP release.
  48  */
  49
  50 #include <linux/skbuff.h>
  51 #include <linux/types.h>
  52 #include <linux/socket.h>
  53 #include <linux/ip.h>
  54 #include <net/sock.h>
  55 #include <net/sctp/sctp.h>
  56 #include <net/sctp/sm.h>
  57
  58 static int sctp_cmd_interpreter(sctp_event_t event_type,
  59                                 sctp_subtype_t subtype,
  60                                 sctp_state_t state,
  61                                 struct sctp_endpoint *ep,
  62                                 struct sctp_association *asoc,
  63                                 void *event_arg,
  64                                 sctp_disposition_t status,
  65                                 sctp_cmd_seq_t *commands,
  66                                 gfp_t gfp);
  67 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
  68                              sctp_state_t state,
  69                              struct sctp_endpoint *ep,
  70                              struct sctp_association *asoc,
  71                              void *event_arg,
  72                              sctp_disposition_t status,
  73                              sctp_cmd_seq_t *commands,
  74                              gfp_t gfp);
  75
  76 /********************************************************************
  77  * Helper functions
  78  ********************************************************************/
  79
  80 /* A helper function for delayed processing of INET ECN CE bit. */
  81 static void sctp_do_ecn_ce_work(struct sctp_association *asoc,
  82                                 __u32 lowest_tsn)
  83 {
  84         /* Save the TSN away for comparison when we receive CWR */
  85
  86         asoc->last_ecne_tsn = lowest_tsn;
  87         asoc->need_ecne = 1;
  88 }
  89
  90 /* Helper function for delayed processing of SCTP ECNE chunk.  */
  91 /* RFC 2960 Appendix A
  92  *
  93  * RFC 2481 details a specific bit for a sender to send in
  94  * the header of its next outbound TCP segment to indicate to
  95  * its peer that it has reduced its congestion window.  This
  96  * is termed the CWR bit.  For SCTP the same indication is made
  97  * by including the CWR chunk.  This chunk contains one data
  98  * element, i.e. the TSN number that was sent in the ECNE chunk.
  99  * This element represents the lowest TSN number in the datagram
 100  * that was originally marked with the CE bit.
 101  */
 102 static struct sctp_chunk *sctp_do_ecn_ecne_work(struct sctp_association *asoc,
 103                                            __u32 lowest_tsn,
 104                                            struct sctp_chunk *chunk)
 105 {
 106         struct sctp_chunk *repl;
 107
 108         /* Our previously transmitted packet ran into some congestion
 109          * so we should take action by reducing cwnd and ssthresh
 110          * and then ACK our peer that we we've done so by
 111          * sending a CWR.
 112          */
 113
 114         /* First, try to determine if we want to actually lower
 115          * our cwnd variables.  Only lower them if the ECNE looks more
 116          * recent than the last response.
 117          */
 118         if (TSN_lt(asoc->last_cwr_tsn, lowest_tsn)) {
 119                 struct sctp_transport *transport;
 120
 121                 /* Find which transport's congestion variables
 122                  * need to be adjusted.
 123                  */
 124                 transport = sctp_assoc_lookup_tsn(asoc, lowest_tsn);
 125
 126                 /* Update the congestion variables. */
 127                 if (transport)
 128                         sctp_transport_lower_cwnd(transport,
 129                                                   SCTP_LOWER_CWND_ECNE);
 130                 asoc->last_cwr_tsn = lowest_tsn;
 131         }
 132
 133         /* Always try to quiet the other end.  In case of lost CWR,
 134          * resend last_cwr_tsn.
 135          */
 136         repl = sctp_make_cwr(asoc, asoc->last_cwr_tsn, chunk);
 137
 138         /* If we run out of memory, it will look like a lost CWR.  We'll
 139          * get back in sync eventually.
 140          */
 141         return repl;
 142 }
 143
 144 /* Helper function to do delayed processing of ECN CWR chunk.  */
 145 static void sctp_do_ecn_cwr_work(struct sctp_association *asoc,
 146                                  __u32 lowest_tsn)
 147 {
 148         /* Turn off ECNE getting auto-prepended to every outgoing
 149          * packet
 150          */
 151         asoc->need_ecne = 0;
 152 }
 153
 154 /* Generate SACK if necessary.  We call this at the end of a packet.  */
 155 static int sctp_gen_sack(struct sctp_association *asoc, int force,
 156                          sctp_cmd_seq_t *commands)
 157 {
 158         __u32 ctsn, max_tsn_seen;
 159         struct sctp_chunk *sack;
 160         struct sctp_transport *trans = asoc->peer.last_data_from;
 161         int error = 0;
 162
 163         if (force ||
 164             (!trans && (asoc->param_flags & SPP_SACKDELAY_DISABLE)) ||
 165             (trans && (trans->param_flags & SPP_SACKDELAY_DISABLE)))
 166                 asoc->peer.sack_needed = 1;
 167
 168         ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
 169         max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
 170
 171         /* From 12.2 Parameters necessary per association (i.e. the TCB):
 172          *
 173          * Ack State : This flag indicates if the next received packet
 174          *           : is to be responded to with a SACK. ...
 175          *           : When DATA chunks are out of order, SACK's
 176          *           : are not delayed (see Section 6).
 177          *
 178          * [This is actually not mentioned in Section 6, but we
 179          * implement it here anyway. --piggy]
 180          */
 181         if (max_tsn_seen != ctsn)
 182                 asoc->peer.sack_needed = 1;
 183
 184         /* From 6.2  Acknowledgement on Reception of DATA Chunks:
 185          *
 186          * Section 4.2 of [RFC2581] SHOULD be followed. Specifically,
 187          * an acknowledgement SHOULD be generated for at least every
 188          * second packet (not every second DATA chunk) received, and
 189          * SHOULD be generated within 200 ms of the arrival of any
 190          * unacknowledged DATA chunk. ...
 191          */
 192         if (!asoc->peer.sack_needed) {
 193                 /* We will need a SACK for the next packet.  */
 194                 asoc->peer.sack_needed = 1;
 195
 196                 /* Set the SACK delay timeout based on the
 197                  * SACK delay for the last transport
 198                  * data was received from, or the default
 199                  * for the association.
 200                  */
 201                 if (trans)
 202                         asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
 203                                 trans->sackdelay;
 204                 else
 205                         asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
 206                                 asoc->sackdelay;
 207
 208                 /* Restart the SACK timer. */
 209                 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
 210                                 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
 211         } else {
 212                 if (asoc->a_rwnd > asoc->rwnd)
 213                         asoc->a_rwnd = asoc->rwnd;
 214                 sack = sctp_make_sack(asoc);
 215                 if (!sack)
 216                         goto nomem;
 217
 218                 asoc->peer.sack_needed = 0;
 219
 220                 error = sctp_outq_tail(&asoc->outqueue, sack);
 221
 222                 /* Stop the SACK timer.  */
 223                 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
 224                                 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
 225         }
 226
 227         return error;
 228 nomem:
 229         error = -ENOMEM;
 230         return error;
 231 }
 232
 233 /* When the T3-RTX timer expires, it calls this function to create the
 234  * relevant state machine event.
 235  */
 236 void sctp_generate_t3_rtx_event(unsigned long peer)
 237 {
 238         int error;
 239         struct sctp_transport *transport = (struct sctp_transport *) peer;
 240         struct sctp_association *asoc = transport->asoc;
 241
 242         /* Check whether a task is in the sock.  */
 243
 244         sctp_bh_lock_sock(asoc->base.sk);
 245         if (sock_owned_by_user(asoc->base.sk)) {
 246                 SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __FUNCTION__);
 247
 248                 /* Try again later.  */
 249                 if (!mod_timer(&transport->T3_rtx_timer, jiffies + (HZ/20)))
 250                         sctp_transport_hold(transport);
 251                 goto out_unlock;
 252         }
 253
 254         /* Is this transport really dead and just waiting around for
 255          * the timer to let go of the reference?
 256          */
 257         if (transport->dead)
 258                 goto out_unlock;
 259
 260         /* Run through the state machine.  */
 261         error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
 262                            SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX),
 263                            asoc->state,
 264                            asoc->ep, asoc,
 265                            transport, GFP_ATOMIC);
 266
 267         if (error)
 268                 asoc->base.sk->sk_err = -error;
 269
 270 out_unlock:
 271         sctp_bh_unlock_sock(asoc->base.sk);
 272         sctp_transport_put(transport);
 273 }
 274
 275 /* This is a sa interface for producing timeout events.  It works
 276  * for timeouts which use the association as their parameter.
 277  */
 278 static void sctp_generate_timeout_event(struct sctp_association *asoc,
 279                                         sctp_event_timeout_t timeout_type)
 280 {
 281         int error = 0;
 282
 283         sctp_bh_lock_sock(asoc->base.sk);
 284         if (sock_owned_by_user(asoc->base.sk)) {
 285                 SCTP_DEBUG_PRINTK("%s:Sock is busy: timer %d\n",
 286                                   __FUNCTION__,
 287                                   timeout_type);
 288
 289                 /* Try again later.  */
 290                 if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20)))
 291                         sctp_association_hold(asoc);
 292                 goto out_unlock;
 293         }
 294
 295         /* Is this association really dead and just waiting around for
 296          * the timer to let go of the reference?
 297          */
 298         if (asoc->base.dead)
 299                 goto out_unlock;
 300
 301         /* Run through the state machine.  */
 302         error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
 303                            SCTP_ST_TIMEOUT(timeout_type),
 304                            asoc->state, asoc->ep, asoc,
 305                            (void *)timeout_type, GFP_ATOMIC);
 306
 307         if (error)
 308                 asoc->base.sk->sk_err = -error;
 309
 310 out_unlock:
 311         sctp_bh_unlock_sock(asoc->base.sk);
 312         sctp_association_put(asoc);
 313 }
 314
 315 static void sctp_generate_t1_cookie_event(unsigned long data)
 316 {
 317         struct sctp_association *asoc = (struct sctp_association *) data;
 318         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
 319 }
 320
 321 static void sctp_generate_t1_init_event(unsigned long data)
 322 {
 323         struct sctp_association *asoc = (struct sctp_association *) data;
 324         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
 325 }
 326
 327 static void sctp_generate_t2_shutdown_event(unsigned long data)
 328 {
 329         struct sctp_association *asoc = (struct sctp_association *) data;
 330         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
 331 }
 332
 333 static void sctp_generate_t4_rto_event(unsigned long data)
 334 {
 335         struct sctp_association *asoc = (struct sctp_association *) data;
 336         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
 337 }
 338
 339 static void sctp_generate_t5_shutdown_guard_event(unsigned long data)
 340 {
 341         struct sctp_association *asoc = (struct sctp_association *)data;
 342         sctp_generate_timeout_event(asoc,
 343                                     SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);
 344
 345 } /* sctp_generate_t5_shutdown_guard_event() */
 346
 347 static void sctp_generate_autoclose_event(unsigned long data)
 348 {
 349         struct sctp_association *asoc = (struct sctp_association *) data;
 350         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE);
 351 }
 352
 353 /* Generate a heart beat event.  If the sock is busy, reschedule.   Make
 354  * sure that the transport is still valid.
 355  */
 356 void sctp_generate_heartbeat_event(unsigned long data)
 357 {
 358         int error = 0;
 359         struct sctp_transport *transport = (struct sctp_transport *) data;
 360         struct sctp_association *asoc = transport->asoc;
 361
 362         sctp_bh_lock_sock(asoc->base.sk);
 363         if (sock_owned_by_user(asoc->base.sk)) {
 364                 SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __FUNCTION__);
 365
 366                 /* Try again later.  */
 367                 if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20)))
 368                         sctp_transport_hold(transport);
 369                 goto out_unlock;
 370         }
 371
 372         /* Is this structure just waiting around for us to actually
 373          * get destroyed?
 374          */
 375         if (transport->dead)
 376                 goto out_unlock;
 377
 378         error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
 379                            SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
 380                            asoc->state, asoc->ep, asoc,
 381                            transport, GFP_ATOMIC);
 382
 383          if (error)
 384                  asoc->base.sk->sk_err = -error;
 385
 386 out_unlock:
 387         sctp_bh_unlock_sock(asoc->base.sk);
 388         sctp_transport_put(transport);
 389 }
 390
 391 /* Inject a SACK Timeout event into the state machine.  */
 392 static void sctp_generate_sack_event(unsigned long data)
 393 {
 394         struct sctp_association *asoc = (struct sctp_association *) data;
 395         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
 396 }
 397
 398 sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
 399         NULL,
 400         sctp_generate_t1_cookie_event,
 401         sctp_generate_t1_init_event,
 402         sctp_generate_t2_shutdown_event,
 403         NULL,
 404         sctp_generate_t4_rto_event,
 405         sctp_generate_t5_shutdown_guard_event,
 406         NULL,
 407         sctp_generate_sack_event,
 408         sctp_generate_autoclose_event,
 409 };
 410
 411
 412 /* RFC 2960 8.2 Path Failure Detection
 413  *
 414  * When its peer endpoint is multi-homed, an endpoint should keep a
 415  * error counter for each of the destination transport addresses of the
 416  * peer endpoint.
 417  *
 418  * Each time the T3-rtx timer expires on any address, or when a
 419  * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
 420  * the error counter of that destination address will be incremented.
 421  * When the value in the error counter exceeds the protocol parameter
 422  * 'Path.Max.Retrans' of that destination address, the endpoint should
 423  * mark the destination transport address as inactive, and a
 424  * notification SHOULD be sent to the upper layer.
 425  *
 426  */
 427 static void sctp_do_8_2_transport_strike(struct sctp_association *asoc,
 428                                          struct sctp_transport *transport)
 429 {
 430         /* The check for association's overall error counter exceeding the
 431          * threshold is done in the state function.
 432          */
 433         asoc->overall_error_count++;
 434
 435         if (transport->state != SCTP_INACTIVE &&
 436             (transport->error_count++ >= transport->pathmaxrxt)) {
 437                 SCTP_DEBUG_PRINTK_IPADDR("transport_strike:association %p",
 438                                          " transport IP: port:%d failed.\n",
 439                                          asoc,
 440                                          (&transport->ipaddr),
 441                                          transport->ipaddr.v4.sin_port);
 442                 sctp_assoc_control_transport(asoc, transport,
 443                                              SCTP_TRANSPORT_DOWN,
 444                                              SCTP_FAILED_THRESHOLD);
 445         }
 446
 447         /* E2) For the destination address for which the timer
 448          * expires, set RTO <- RTO * 2 ("back off the timer").  The
 449          * maximum value discussed in rule C7 above (RTO.max) may be
 450          * used to provide an upper bound to this doubling operation.
 451          */
 452         transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
 453 }
 454
 455 /* Worker routine to handle INIT command failure.  */
 456 static void sctp_cmd_init_failed(sctp_cmd_seq_t *commands,
 457                                  struct sctp_association *asoc,
 458                                  unsigned error)
 459 {
 460         struct sctp_ulpevent *event;
 461
 462         event = sctp_ulpevent_make_assoc_change(asoc,0, SCTP_CANT_STR_ASSOC,
 463                                                 (__u16)error, 0, 0,
 464                                                 GFP_ATOMIC);
 465
 466         if (event)
 467                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 468                                 SCTP_ULPEVENT(event));
 469
 470         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 471                         SCTP_STATE(SCTP_STATE_CLOSED));
 472
 473         /* SEND_FAILED sent later when cleaning up the association. */
 474         asoc->outqueue.error = error;
 475         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 476 }
 477
 478 /* Worker routine to handle SCTP_CMD_ASSOC_FAILED.  */
 479 static void sctp_cmd_assoc_failed(sctp_cmd_seq_t *commands,
 480                                   struct sctp_association *asoc,
 481                                   sctp_event_t event_type,
 482                                   sctp_subtype_t subtype,
 483                                   struct sctp_chunk *chunk,
 484                                   unsigned error)
 485 {
 486         struct sctp_ulpevent *event;
 487
 488         /* Cancel any partial delivery in progress. */
 489         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
 490
 491         event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
 492                                                 (__u16)error, 0, 0,
 493                                                 GFP_ATOMIC);
 494         if (event)
 495                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 496                                 SCTP_ULPEVENT(event));
 497
 498         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 499                         SCTP_STATE(SCTP_STATE_CLOSED));
 500
 501         /* Set sk_err to ECONNRESET on a 1-1 style socket. */
 502         if (!sctp_style(asoc->base.sk, UDP))
 503                 asoc->base.sk->sk_err = ECONNRESET;
 504
 505         /* SEND_FAILED sent later when cleaning up the association. */
 506         asoc->outqueue.error = error;
 507         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 508 }
 509
 510 /* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
 511  * inside the cookie.  In reality, this is only used for INIT-ACK processing
 512  * since all other cases use "temporary" associations and can do all
 513  * their work in statefuns directly.
 514  */
 515 static int sctp_cmd_process_init(sctp_cmd_seq_t *commands,
 516                                  struct sctp_association *asoc,
 517                                  struct sctp_chunk *chunk,
 518                                  sctp_init_chunk_t *peer_init,
 519                                  gfp_t gfp)
 520 {
 521         int error;
 522
 523         /* We only process the init as a sideeffect in a single
 524          * case.   This is when we process the INIT-ACK.   If we
 525          * fail during INIT processing (due to malloc problems),
 526          * just return the error and stop processing the stack.
 527          */
 528         if (!sctp_process_init(asoc, chunk->chunk_hdr->type,
 529                                sctp_source(chunk), peer_init, gfp))
 530                 error = -ENOMEM;
 531         else
 532                 error = 0;
 533
 534         return error;
 535 }
 536
 537 /* Helper function to break out starting up of heartbeat timers.  */
 538 static void sctp_cmd_hb_timers_start(sctp_cmd_seq_t *cmds,
 539                                      struct sctp_association *asoc)
 540 {
 541         struct sctp_transport *t;
 542         struct list_head *pos;
 543
 544         /* Start a heartbeat timer for each transport on the association.
 545          * hold a reference on the transport to make sure none of
 546          * the needed data structures go away.
 547          */
 548         list_for_each(pos, &asoc->peer.transport_addr_list) {
 549                 t = list_entry(pos, struct sctp_transport, transports);
 550
 551                 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 552                         sctp_transport_hold(t);
 553         }
 554 }
 555
 556 static void sctp_cmd_hb_timers_stop(sctp_cmd_seq_t *cmds,
 557                                     struct sctp_association *asoc)
 558 {
 559         struct sctp_transport *t;
 560         struct list_head *pos;
 561
 562         /* Stop all heartbeat timers. */
 563
 564         list_for_each(pos, &asoc->peer.transport_addr_list) {
 565                 t = list_entry(pos, struct sctp_transport, transports);
 566                 if (del_timer(&t->hb_timer))
 567                         sctp_transport_put(t);
 568         }
 569 }
 570
 571 /* Helper function to stop any pending T3-RTX timers */
 572 static void sctp_cmd_t3_rtx_timers_stop(sctp_cmd_seq_t *cmds,
 573                                         struct sctp_association *asoc)
 574 {
 575         struct sctp_transport *t;
 576         struct list_head *pos;
 577
 578         list_for_each(pos, &asoc->peer.transport_addr_list) {
 579                 t = list_entry(pos, struct sctp_transport, transports);
 580                 if (timer_pending(&t->T3_rtx_timer) &&
 581                     del_timer(&t->T3_rtx_timer)) {
 582                         sctp_transport_put(t);
 583                 }
 584         }
 585 }
 586
 587
 588 /* Helper function to update the heartbeat timer. */
 589 static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
 590                                      struct sctp_association *asoc,
 591                                      struct sctp_transport *t)
 592 {
 593         /* Update the heartbeat timer.  */
 594         if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 595                 sctp_transport_hold(t);
 596 }
 597
 598 /* Helper function to handle the reception of an HEARTBEAT ACK.  */
 599 static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds,
 600                                   struct sctp_association *asoc,
 601                                   struct sctp_transport *t,
 602                                   struct sctp_chunk *chunk)
 603 {
 604         sctp_sender_hb_info_t *hbinfo;
 605
 606         /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
 607          * HEARTBEAT should clear the error counter of the destination
 608          * transport address to which the HEARTBEAT was sent.
 609          * The association's overall error count is also cleared.
 610          */
 611         t->error_count = 0;
 612         t->asoc->overall_error_count = 0;
 613
 614         /* Mark the destination transport address as active if it is not so
 615          * marked.
 616          */
 617         if (t->state == SCTP_INACTIVE)
 618                 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
 619                                              SCTP_HEARTBEAT_SUCCESS);
 620
 621         /* The receiver of the HEARTBEAT ACK should also perform an
 622          * RTT measurement for that destination transport address
 623          * using the time value carried in the HEARTBEAT ACK chunk.
 624          */
 625         hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
 626         sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
 627 }
 628
 629 /* Helper function to do a transport reset at the expiry of the hearbeat
 630  * timer.
 631  */
 632 static void sctp_cmd_transport_reset(sctp_cmd_seq_t *cmds,
 633                                      struct sctp_association *asoc,
 634                                      struct sctp_transport *t)
 635 {
 636         sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
 637
 638         /* Mark one strike against a transport.  */
 639         sctp_do_8_2_transport_strike(asoc, t);
 640 }
 641
 642 /* Helper function to process the process SACK command.  */
 643 static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds,
 644                                  struct sctp_association *asoc,
 645                                  struct sctp_sackhdr *sackh)
 646 {
 647         int err;
 648
 649         if (sctp_outq_sack(&asoc->outqueue, sackh)) {
 650                 /* There are no more TSNs awaiting SACK.  */
 651                 err = sctp_do_sm(SCTP_EVENT_T_OTHER,
 652                                  SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
 653                                  asoc->state, asoc->ep, asoc, NULL,
 654                                  GFP_ATOMIC);
 655         } else {
 656                 /* Windows may have opened, so we need
 657                  * to check if we have DATA to transmit
 658                  */
 659                 err = sctp_outq_flush(&asoc->outqueue, 0);
 660         }
 661
 662         return err;
 663 }
 664
 665 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
 666  * the transport for a shutdown chunk.
 667  */
 668 static void sctp_cmd_setup_t2(sctp_cmd_seq_t *cmds,
 669                               struct sctp_association *asoc,
 670                               struct sctp_chunk *chunk)
 671 {
 672         struct sctp_transport *t;
 673
 674         t = sctp_assoc_choose_shutdown_transport(asoc);
 675         asoc->shutdown_last_sent_to = t;
 676         asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
 677         chunk->transport = t;
 678 }
 679
 680 /* Helper function to change the state of an association. */
 681 static void sctp_cmd_new_state(sctp_cmd_seq_t *cmds,
 682                                struct sctp_association *asoc,
 683                                sctp_state_t state)
 684 {
 685         struct sock *sk = asoc->base.sk;
 686
 687         asoc->state = state;
 688
 689         SCTP_DEBUG_PRINTK("sctp_cmd_new_state: asoc %p[%s]\n",
 690                           asoc, sctp_state_tbl[state]);
 691
 692         if (sctp_style(sk, TCP)) {
 693                 /* Change the sk->sk_state of a TCP-style socket that has
 694                  * sucessfully completed a connect() call.
 695                  */
 696                 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
 697                         sk->sk_state = SCTP_SS_ESTABLISHED;
 698
 699                 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
 700                 if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
 701                     sctp_sstate(sk, ESTABLISHED))
 702                         sk->sk_shutdown |= RCV_SHUTDOWN;
 703         }
 704
 705         if (sctp_state(asoc, COOKIE_WAIT)) {
 706                 /* Reset init timeouts since they may have been
 707                  * increased due to timer expirations.
 708                  */
 709                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
 710                                                 asoc->rto_initial;
 711                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
 712                                                 asoc->rto_initial;
 713         }
 714
 715         if (sctp_state(asoc, ESTABLISHED) ||
 716             sctp_state(asoc, CLOSED) ||
 717             sctp_state(asoc, SHUTDOWN_RECEIVED)) {
 718                 /* Wake up any processes waiting in the asoc's wait queue in
 719                  * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
 720                  */
 721                 if (waitqueue_active(&asoc->wait))
 722                         wake_up_interruptible(&asoc->wait);
 723
 724                 /* Wake up any processes waiting in the sk's sleep queue of
 725                  * a TCP-style or UDP-style peeled-off socket in
 726                  * sctp_wait_for_accept() or sctp_wait_for_packet().
 727                  * For a UDP-style socket, the waiters are woken up by the
 728                  * notifications.
 729                  */
 730                 if (!sctp_style(sk, UDP))
 731                         sk->sk_state_change(sk);
 732         }
 733 }
 734
 735 /* Helper function to delete an association. */
 736 static void sctp_cmd_delete_tcb(sctp_cmd_seq_t *cmds,
 737                                 struct sctp_association *asoc)
 738 {
 739         struct sock *sk = asoc->base.sk;
 740
 741         /* If it is a non-temporary association belonging to a TCP-style
 742          * listening socket that is not closed, do not free it so that accept()
 743          * can pick it up later.
 744          */
 745         if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
 746             (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
 747                 return;
 748
 749         sctp_unhash_established(asoc);
 750         sctp_association_free(asoc);
 751 }
 752
 753 /*
 754  * ADDIP Section 4.1 ASCONF Chunk Procedures
 755  * A4) Start a T-4 RTO timer, using the RTO value of the selected
 756  * destination address (we use active path instead of primary path just
 757  * because primary path may be inactive.
 758  */
 759 static void sctp_cmd_setup_t4(sctp_cmd_seq_t *cmds,
 760                                 struct sctp_association *asoc,
 761                                 struct sctp_chunk *chunk)
 762 {
 763         struct sctp_transport *t;
 764
 765         t = asoc->peer.active_path;
 766         asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
 767         chunk->transport = t;
 768 }
 769
 770 /* Process an incoming Operation Error Chunk. */
 771 static void sctp_cmd_process_operr(sctp_cmd_seq_t *cmds,
 772                                    struct sctp_association *asoc,
 773                                    struct sctp_chunk *chunk)
 774 {
 775         struct sctp_operr_chunk *operr_chunk;
 776         struct sctp_errhdr *err_hdr;
 777
 778         operr_chunk = (struct sctp_operr_chunk *)chunk->chunk_hdr;
 779         err_hdr = &operr_chunk->err_hdr;
 780
 781         switch (err_hdr->cause) {
 782         case SCTP_ERROR_UNKNOWN_CHUNK:
 783         {
 784                 struct sctp_chunkhdr *unk_chunk_hdr;
 785
 786                 unk_chunk_hdr = (struct sctp_chunkhdr *)err_hdr->variable;
 787                 switch (unk_chunk_hdr->type) {
 788                 /* ADDIP 4.1 A9) If the peer responds to an ASCONF with an
 789                  * ERROR chunk reporting that it did not recognized the ASCONF
 790                  * chunk type, the sender of the ASCONF MUST NOT send any
 791                  * further ASCONF chunks and MUST stop its T-4 timer.
 792                  */
 793                 case SCTP_CID_ASCONF:
 794                         asoc->peer.asconf_capable = 0;
 795                         sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
 796                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
 797                         break;
 798                 default:
 799                         break;
 800                 }
 801                 break;
 802         }
 803         default:
 804                 break;
 805         }
 806 }
 807
 808 /* Process variable FWDTSN chunk information. */
 809 static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq,
 810                                     struct sctp_chunk *chunk)
 811 {
 812         struct sctp_fwdtsn_skip *skip;
 813         /* Walk through all the skipped SSNs */
 814         sctp_walk_fwdtsn(skip, chunk) {
 815                 sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
 816         }
 817
 818         return;
 819 }
 820
 821 /* Helper function to remove the association non-primary peer
 822  * transports.
 823  */
 824 static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
 825 {
 826         struct sctp_transport *t;
 827         struct list_head *pos;
 828         struct list_head *temp;
 829
 830         list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
 831                 t = list_entry(pos, struct sctp_transport, transports);
 832                 if (!sctp_cmp_addr_exact(&t->ipaddr,
 833                                          &asoc->peer.primary_addr)) {
 834                         sctp_assoc_del_peer(asoc, &t->ipaddr);
 835                 }
 836         }
 837
 838         return;
 839 }
 840
 841 /* These three macros allow us to pull the debugging code out of the
 842  * main flow of sctp_do_sm() to keep attention focused on the real
 843  * functionality there.
 844  */
 845 #define DEBUG_PRE \
 846         SCTP_DEBUG_PRINTK("sctp_do_sm prefn: " \
 847                           "ep %p, %s, %s, asoc %p[%s], %s\n", \
 848                           ep, sctp_evttype_tbl[event_type], \
 849                           (*debug_fn)(subtype), asoc, \
 850                           sctp_state_tbl[state], state_fn->name)
 851
 852 #define DEBUG_POST \
 853         SCTP_DEBUG_PRINTK("sctp_do_sm postfn: " \
 854                           "asoc %p, status: %s\n", \
 855                           asoc, sctp_status_tbl[status])
 856
 857 #define DEBUG_POST_SFX \
 858         SCTP_DEBUG_PRINTK("sctp_do_sm post sfx: error %d, asoc %p[%s]\n", \
 859                           error, asoc, \
 860                           sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
 861                           sctp_assoc2id(asoc)))?asoc->state:SCTP_STATE_CLOSED])
 862
 863 /*
 864  * This is the master state machine processing function.
 865  *
 866  * If you want to understand all of lksctp, this is a
 867  * good place to start.
 868  */
 869 int sctp_do_sm(sctp_event_t event_type, sctp_subtype_t subtype,
 870                sctp_state_t state,
 871                struct sctp_endpoint *ep,
 872                struct sctp_association *asoc,
 873                void *event_arg,
 874                gfp_t gfp)
 875 {
 876         sctp_cmd_seq_t commands;
 877         const sctp_sm_table_entry_t *state_fn;
 878         sctp_disposition_t status;
 879         int error = 0;
 880         typedef const char *(printfn_t)(sctp_subtype_t);
 881
 882         static printfn_t *table[] = {
 883                 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
 884         };
 885         printfn_t *debug_fn  __attribute__ ((unused)) = table[event_type];
 886
 887         /* Look up the state function, run it, and then process the
 888          * side effects.  These three steps are the heart of lksctp.
 889          */
 890         state_fn = sctp_sm_lookup_event(event_type, state, subtype);
 891
 892         sctp_init_cmd_seq(&commands);
 893
 894         DEBUG_PRE;
 895         status = (*state_fn->fn)(ep, asoc, subtype, event_arg, &commands);
 896         DEBUG_POST;
 897
 898         error = sctp_side_effects(event_type, subtype, state,
 899                                   ep, asoc, event_arg, status,
 900                                   &commands, gfp);
 901         DEBUG_POST_SFX;
 902
 903         return error;
 904 }
 905
 906 #undef DEBUG_PRE
 907 #undef DEBUG_POST
 908
 909 /*****************************************************************
 910  * This the master state function side effect processing function.
 911  *****************************************************************/
 912 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
 913                              sctp_state_t state,
 914                              struct sctp_endpoint *ep,
 915                              struct sctp_association *asoc,
 916                              void *event_arg,
 917                              sctp_disposition_t status,
 918                              sctp_cmd_seq_t *commands,
 919                              gfp_t gfp)
 920 {
 921         int error;
 922
 923         /* FIXME - Most of the dispositions left today would be categorized
 924          * as "exceptional" dispositions.  For those dispositions, it
 925          * may not be proper to run through any of the commands at all.
 926          * For example, the command interpreter might be run only with
 927          * disposition SCTP_DISPOSITION_CONSUME.
 928          */
 929         if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
 930                                                ep, asoc,
 931                                                event_arg, status,
 932                                                commands, gfp)))
 933                 goto bail;
 934
 935         switch (status) {
 936         case SCTP_DISPOSITION_DISCARD:
 937                 SCTP_DEBUG_PRINTK("Ignored sctp protocol event - state %d, "
 938                                   "event_type %d, event_id %d\n",
 939                                   state, event_type, subtype.chunk);
 940                 break;
 941
 942         case SCTP_DISPOSITION_NOMEM:
 943                 /* We ran out of memory, so we need to discard this
 944                  * packet.
 945                  */
 946                 /* BUG--we should now recover some memory, probably by
 947                  * reneging...
 948                  */
 949                 error = -ENOMEM;
 950                 break;
 951
 952         case SCTP_DISPOSITION_DELETE_TCB:
 953                 /* This should now be a command. */
 954                 break;
 955
 956         case SCTP_DISPOSITION_CONSUME:
 957         case SCTP_DISPOSITION_ABORT:
 958                 /*
 959                  * We should no longer have much work to do here as the
 960                  * real work has been done as explicit commands above.
 961                  */
 962                 break;
 963
 964         case SCTP_DISPOSITION_VIOLATION:
 965                 printk(KERN_ERR "sctp protocol violation state %d "
 966                        "chunkid %d\n", state, subtype.chunk);
 967                 break;
 968
 969         case SCTP_DISPOSITION_NOT_IMPL:
 970                 printk(KERN_WARNING "sctp unimplemented feature in state %d, "
 971                        "event_type %d, event_id %d\n",
 972                        state, event_type, subtype.chunk);
 973                 break;
 974
 975         case SCTP_DISPOSITION_BUG:
 976                 printk(KERN_ERR "sctp bug in state %d, "
 977                        "event_type %d, event_id %d\n",
 978                        state, event_type, subtype.chunk);
 979                 BUG();
 980                 break;
 981
 982         default:
 983                 printk(KERN_ERR "sctp impossible disposition %d "
 984                        "in state %d, event_type %d, event_id %d\n",
 985                        status, state, event_type, subtype.chunk);
 986                 BUG();
 987                 break;
 988         };
 989
 990 bail:
 991         return error;
 992 }
 993
 994 /********************************************************************
 995  * 2nd Level Abstractions
 996  ********************************************************************/
 997
 998 /* This is the side-effect interpreter.  */
 999 static int sctp_cmd_interpreter(sctp_event_t event_type,
1000                                 sctp_subtype_t subtype,
1001                                 sctp_state_t state,
1002                                 struct sctp_endpoint *ep,
1003                                 struct sctp_association *asoc,
1004                                 void *event_arg,
1005                                 sctp_disposition_t status,
1006                                 sctp_cmd_seq_t *commands,
1007                                 gfp_t gfp)
1008 {
1009         int error = 0;
1010         int force;
1011         sctp_cmd_t *cmd;
1012         struct sctp_chunk *new_obj;
1013         struct sctp_chunk *chunk = NULL;
1014         struct sctp_packet *packet;
1015         struct list_head *pos;
1016         struct timer_list *timer;
1017         unsigned long timeout;
1018         struct sctp_transport *t;
1019         struct sctp_sackhdr sackh;
1020         int local_cork = 0;
1021
1022         if (SCTP_EVENT_T_TIMEOUT != event_type)
1023                 chunk = (struct sctp_chunk *) event_arg;
1024
1025         /* Note:  This whole file is a huge candidate for rework.
1026          * For example, each command could either have its own handler, so
1027          * the loop would look like:
1028          *     while (cmds)
1029          *         cmd->handle(x, y, z)
1030          * --jgrimm
1031          */
1032         while (NULL != (cmd = sctp_next_cmd(commands))) {
1033                 switch (cmd->verb) {
1034                 case SCTP_CMD_NOP:
1035                         /* Do nothing. */
1036                         break;
1037
1038                 case SCTP_CMD_NEW_ASOC:
1039                         /* Register a new association.  */
1040                         if (local_cork) {
1041                                 sctp_outq_uncork(&asoc->outqueue);
1042                                 local_cork = 0;
1043                         }
1044                         asoc = cmd->obj.ptr;
1045                         /* Register with the endpoint.  */
1046                         sctp_endpoint_add_asoc(ep, asoc);
1047                         sctp_hash_established(asoc);
1048                         break;
1049
1050                 case SCTP_CMD_UPDATE_ASSOC:
1051                        sctp_assoc_update(asoc, cmd->obj.ptr);
1052                        break;
1053
1054                 case SCTP_CMD_PURGE_OUTQUEUE:
1055                        sctp_outq_teardown(&asoc->outqueue);
1056                        break;
1057
1058                 case SCTP_CMD_DELETE_TCB:
1059                         if (local_cork) {
1060                                 sctp_outq_uncork(&asoc->outqueue);
1061                                 local_cork = 0;
1062                         }
1063                         /* Delete the current association.  */
1064                         sctp_cmd_delete_tcb(commands, asoc);
1065                         asoc = NULL;
1066                         break;
1067
1068                 case SCTP_CMD_NEW_STATE:
1069                         /* Enter a new state.  */
1070                         sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1071                         break;
1072
1073                 case SCTP_CMD_REPORT_TSN:
1074                         /* Record the arrival of a TSN.  */
1075                         sctp_tsnmap_mark(&asoc->peer.tsn_map, cmd->obj.u32);
1076                         break;
1077
1078                 case SCTP_CMD_REPORT_FWDTSN:
1079                         /* Move the Cumulattive TSN Ack ahead. */
1080                         sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32);
1081
1082                         /* Abort any in progress partial delivery. */
1083                         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
1084                         break;
1085
1086                 case SCTP_CMD_PROCESS_FWDTSN:
1087                         sctp_cmd_process_fwdtsn(&asoc->ulpq, cmd->obj.ptr);
1088                         break;
1089
1090                 case SCTP_CMD_GEN_SACK:
1091                         /* Generate a Selective ACK.
1092                          * The argument tells us whether to just count
1093                          * the packet and MAYBE generate a SACK, or
1094                          * force a SACK out.
1095                          */
1096                         force = cmd->obj.i32;
1097                         error = sctp_gen_sack(asoc, force, commands);
1098                         break;
1099
1100                 case SCTP_CMD_PROCESS_SACK:
1101                         /* Process an inbound SACK.  */
1102                         error = sctp_cmd_process_sack(commands, asoc,
1103                                                       cmd->obj.ptr);
1104                         break;
1105
1106                 case SCTP_CMD_GEN_INIT_ACK:
1107                         /* Generate an INIT ACK chunk.  */
1108                         new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1109                                                      0);
1110                         if (!new_obj)
1111                                 goto nomem;
1112
1113                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1114                                         SCTP_CHUNK(new_obj));
1115                         break;
1116
1117                 case SCTP_CMD_PEER_INIT:
1118                         /* Process a unified INIT from the peer.
1119                          * Note: Only used during INIT-ACK processing.  If
1120                          * there is an error just return to the outter
1121                          * layer which will bail.
1122                          */
1123                         error = sctp_cmd_process_init(commands, asoc, chunk,
1124                                                       cmd->obj.ptr, gfp);
1125                         break;
1126
1127                 case SCTP_CMD_GEN_COOKIE_ECHO:
1128                         /* Generate a COOKIE ECHO chunk.  */
1129                         new_obj = sctp_make_cookie_echo(asoc, chunk);
1130                         if (!new_obj) {
1131                                 if (cmd->obj.ptr)
1132                                         sctp_chunk_free(cmd->obj.ptr);
1133                                 goto nomem;
1134                         }
1135                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1136                                         SCTP_CHUNK(new_obj));
1137
1138                         /* If there is an ERROR chunk to be sent along with
1139                          * the COOKIE_ECHO, send it, too.
1140                          */
1141                         if (cmd->obj.ptr)
1142                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1143                                                 SCTP_CHUNK(cmd->obj.ptr));
1144
1145                         /* FIXME - Eventually come up with a cleaner way to
1146                          * enabling COOKIE-ECHO + DATA bundling during
1147                          * multihoming stale cookie scenarios, the following
1148                          * command plays with asoc->peer.retran_path to
1149                          * avoid the problem of sending the COOKIE-ECHO and
1150                          * DATA in different paths, which could result
1151                          * in the association being ABORTed if the DATA chunk
1152                          * is processed first by the server.  Checking the
1153                          * init error counter simply causes this command
1154                          * to be executed only during failed attempts of
1155                          * association establishment.
1156                          */
1157                         if ((asoc->peer.retran_path !=
1158                              asoc->peer.primary_path) &&
1159                             (asoc->init_err_counter > 0)) {
1160                                 sctp_add_cmd_sf(commands,
1161                                                 SCTP_CMD_FORCE_PRIM_RETRAN,
1162                                                 SCTP_NULL());
1163                         }
1164
1165                         break;
1166
1167                 case SCTP_CMD_GEN_SHUTDOWN:
1168                         /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1169                          * Reset error counts.
1170                          */
1171                         asoc->overall_error_count = 0;
1172
1173                         /* Generate a SHUTDOWN chunk.  */
1174                         new_obj = sctp_make_shutdown(asoc, chunk);
1175                         if (!new_obj)
1176                                 goto nomem;
1177                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1178                                         SCTP_CHUNK(new_obj));
1179                         break;
1180
1181                 case SCTP_CMD_CHUNK_ULP:
1182                         /* Send a chunk to the sockets layer.  */
1183                         SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1184                                           "chunk_up:", cmd->obj.ptr,
1185                                           "ulpq:", &asoc->ulpq);
1186                         sctp_ulpq_tail_data(&asoc->ulpq, cmd->obj.ptr,
1187                                             GFP_ATOMIC);
1188                         break;
1189
1190                 case SCTP_CMD_EVENT_ULP:
1191                         /* Send a notification to the sockets layer.  */
1192                         SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1193                                           "event_up:",cmd->obj.ptr,
1194                                           "ulpq:",&asoc->ulpq);
1195                         sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ptr);
1196                         break;
1197
1198                 case SCTP_CMD_REPLY:
1199                         /* If an caller has not already corked, do cork. */
1200                         if (!asoc->outqueue.cork) {
1201                                 sctp_outq_cork(&asoc->outqueue);
1202                                 local_cork = 1;
1203                         }
1204                         /* Send a chunk to our peer.  */
1205                         error = sctp_outq_tail(&asoc->outqueue, cmd->obj.ptr);
1206                         break;
1207
1208                 case SCTP_CMD_SEND_PKT:
1209                         /* Send a full packet to our peer.  */
1210                         packet = cmd->obj.ptr;
1211                         sctp_packet_transmit(packet);
1212                         sctp_ootb_pkt_free(packet);
1213                         break;
1214
1215                 case SCTP_CMD_RETRAN:
1216                         /* Mark a transport for retransmission.  */
1217                         sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1218                                         SCTP_RTXR_T3_RTX);
1219                         break;
1220
1221                 case SCTP_CMD_TRANSMIT:
1222                         /* Kick start transmission. */
1223                         error = sctp_outq_uncork(&asoc->outqueue);
1224                         local_cork = 0;
1225                         break;
1226
1227                 case SCTP_CMD_ECN_CE:
1228                         /* Do delayed CE processing.   */
1229                         sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1230                         break;
1231
1232                 case SCTP_CMD_ECN_ECNE:
1233                         /* Do delayed ECNE processing. */
1234                         new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1235                                                         chunk);
1236                         if (new_obj)
1237                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1238                                                 SCTP_CHUNK(new_obj));
1239                         break;
1240
1241                 case SCTP_CMD_ECN_CWR:
1242                         /* Do delayed CWR processing.  */
1243                         sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1244                         break;
1245
1246                 case SCTP_CMD_SETUP_T2:
1247                         sctp_cmd_setup_t2(commands, asoc, cmd->obj.ptr);
1248                         break;
1249
1250                 case SCTP_CMD_TIMER_START:
1251                         timer = &asoc->timers[cmd->obj.to];
1252                         timeout = asoc->timeouts[cmd->obj.to];
1253                         if (!timeout)
1254                                 BUG();
1255
1256                         timer->expires = jiffies + timeout;
1257                         sctp_association_hold(asoc);
1258                         add_timer(timer);
1259                         break;
1260
1261                 case SCTP_CMD_TIMER_RESTART:
1262                         timer = &asoc->timers[cmd->obj.to];
1263                         timeout = asoc->timeouts[cmd->obj.to];
1264                         if (!mod_timer(timer, jiffies + timeout))
1265                                 sctp_association_hold(asoc);
1266                         break;
1267
1268                 case SCTP_CMD_TIMER_STOP:
1269                         timer = &asoc->timers[cmd->obj.to];
1270                         if (timer_pending(timer) && del_timer(timer))
1271                                 sctp_association_put(asoc);
1272                         break;
1273
1274                 case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1275                         chunk = cmd->obj.ptr;
1276                         t = sctp_assoc_choose_init_transport(asoc);
1277                         asoc->init_last_sent_to = t;
1278                         chunk->transport = t;
1279                         t->init_sent_count++;
1280                         break;
1281
1282                 case SCTP_CMD_INIT_RESTART:
1283                         /* Do the needed accounting and updates
1284                          * associated with restarting an initialization
1285                          * timer. Only multiply the timeout by two if
1286                          * all transports have been tried at the current
1287                          * timeout.
1288                          */
1289                         t = asoc->init_last_sent_to;
1290                         asoc->init_err_counter++;
1291
1292                         if (t->init_sent_count > (asoc->init_cycle + 1)) {
1293                                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] *= 2;
1294                                 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] >
1295                                     asoc->max_init_timeo) {
1296                                         asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
1297                                                 asoc->max_init_timeo;
1298                                 }
1299                                 asoc->init_cycle++;
1300                                 SCTP_DEBUG_PRINTK(
1301                                         "T1 INIT Timeout adjustment"
1302                                         " init_err_counter: %d"
1303                                         " cycle: %d"
1304                                         " timeout: %d\n",
1305                                         asoc->init_err_counter,
1306                                         asoc->init_cycle,
1307                                         asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT]);
1308                         }
1309
1310                         sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1311                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1312                         break;
1313
1314                 case SCTP_CMD_COOKIEECHO_RESTART:
1315                         /* Do the needed accounting and updates
1316                          * associated with restarting an initialization
1317                          * timer. Only multiply the timeout by two if
1318                          * all transports have been tried at the current
1319                          * timeout.
1320                          */
1321                         asoc->init_err_counter++;
1322
1323                         asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] *= 2;
1324                         if (asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] >
1325                             asoc->max_init_timeo) {
1326                                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
1327                                         asoc->max_init_timeo;
1328                         }
1329                         SCTP_DEBUG_PRINTK(
1330                                 "T1 COOKIE Timeout adjustment"
1331                                 " init_err_counter: %d"
1332                                 " timeout: %d\n",
1333                                 asoc->init_err_counter,
1334                                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE]);
1335
1336                         /* If we've sent any data bundled with
1337                          * COOKIE-ECHO we need to resend.
1338                          */
1339                         list_for_each(pos, &asoc->peer.transport_addr_list) {
1340                                 t = list_entry(pos, struct sctp_transport,
1341                                                transports);
1342                                 sctp_retransmit_mark(&asoc->outqueue, t, 0);
1343                         }
1344
1345                         sctp_add_cmd_sf(commands,
1346                                         SCTP_CMD_TIMER_RESTART,
1347                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1348                         break;
1349
1350                 case SCTP_CMD_INIT_FAILED:
1351                         sctp_cmd_init_failed(commands, asoc, cmd->obj.u32);
1352                         break;
1353
1354                 case SCTP_CMD_ASSOC_FAILED:
1355                         sctp_cmd_assoc_failed(commands, asoc, event_type,
1356                                               subtype, chunk, cmd->obj.u32);
1357                         break;
1358
1359                 case SCTP_CMD_INIT_COUNTER_INC:
1360                         asoc->init_err_counter++;
1361                         break;
1362
1363                 case SCTP_CMD_INIT_COUNTER_RESET:
1364                         asoc->init_err_counter = 0;
1365                         asoc->init_cycle = 0;
1366                         break;
1367
1368                 case SCTP_CMD_REPORT_DUP:
1369                         sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1370                                              cmd->obj.u32);
1371                         break;
1372
1373                 case SCTP_CMD_REPORT_BAD_TAG:
1374                         SCTP_DEBUG_PRINTK("vtag mismatch!\n");
1375                         break;
1376
1377                 case SCTP_CMD_STRIKE:
1378                         /* Mark one strike against a transport.  */
1379                         sctp_do_8_2_transport_strike(asoc, cmd->obj.transport);
1380                         break;
1381
1382                 case SCTP_CMD_TRANSPORT_RESET:
1383                         t = cmd->obj.transport;
1384                         sctp_cmd_transport_reset(commands, asoc, t);
1385                         break;
1386
1387                 case SCTP_CMD_TRANSPORT_ON:
1388                         t = cmd->obj.transport;
1389                         sctp_cmd_transport_on(commands, asoc, t, chunk);
1390                         break;
1391
1392                 case SCTP_CMD_HB_TIMERS_START:
1393                         sctp_cmd_hb_timers_start(commands, asoc);
1394                         break;
1395
1396                 case SCTP_CMD_HB_TIMER_UPDATE:
1397                         t = cmd->obj.transport;
1398                         sctp_cmd_hb_timer_update(commands, asoc, t);
1399                         break;
1400
1401                 case SCTP_CMD_HB_TIMERS_STOP:
1402                         sctp_cmd_hb_timers_stop(commands, asoc);
1403                         break;
1404
1405                 case SCTP_CMD_REPORT_ERROR:
1406                         error = cmd->obj.error;
1407                         break;
1408
1409                 case SCTP_CMD_PROCESS_CTSN:
1410                         /* Dummy up a SACK for processing. */
1411                         sackh.cum_tsn_ack = cmd->obj.u32;
1412                         sackh.a_rwnd = 0;
1413                         sackh.num_gap_ack_blocks = 0;
1414                         sackh.num_dup_tsns = 0;
1415                         sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1416                                         SCTP_SACKH(&sackh));
1417                         break;
1418
1419                 case SCTP_CMD_DISCARD_PACKET:
1420                         /* We need to discard the whole packet.  */
1421                         chunk->pdiscard = 1;
1422                         break;
1423
1424                 case SCTP_CMD_RTO_PENDING:
1425                         t = cmd->obj.transport;
1426                         t->rto_pending = 1;
1427                         break;
1428
1429                 case SCTP_CMD_PART_DELIVER:
1430                         sctp_ulpq_partial_delivery(&asoc->ulpq, cmd->obj.ptr,
1431                                                    GFP_ATOMIC);
1432                         break;
1433
1434                 case SCTP_CMD_RENEGE:
1435                         sctp_ulpq_renege(&asoc->ulpq, cmd->obj.ptr,
1436                                          GFP_ATOMIC);
1437                         break;
1438
1439                 case SCTP_CMD_SETUP_T4:
1440                         sctp_cmd_setup_t4(commands, asoc, cmd->obj.ptr);
1441                         break;
1442
1443                 case SCTP_CMD_PROCESS_OPERR:
1444                         sctp_cmd_process_operr(commands, asoc, chunk);
1445                         break;
1446                 case SCTP_CMD_CLEAR_INIT_TAG:
1447                         asoc->peer.i.init_tag = 0;
1448                         break;
1449                 case SCTP_CMD_DEL_NON_PRIMARY:
1450                         sctp_cmd_del_non_primary(asoc);
1451                         break;
1452                 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1453                         sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1454                         break;
1455                 case SCTP_CMD_FORCE_PRIM_RETRAN:
1456                         t = asoc->peer.retran_path;
1457                         asoc->peer.retran_path = asoc->peer.primary_path;
1458                         error = sctp_outq_uncork(&asoc->outqueue);
1459                         local_cork = 0;
1460                         asoc->peer.retran_path = t;
1461                         break;
1462                 default:
1463                         printk(KERN_WARNING "Impossible command: %u, %p\n",
1464                                cmd->verb, cmd->obj.ptr);
1465                         break;
1466                 };
1467                 if (error)
1468                         break;
1469         }
1470
1471 out:
1472         if (local_cork)
1473                 sctp_outq_uncork(&asoc->outqueue);
1474         return error;
1475 nomem:
1476         error = -ENOMEM;
1477         goto out;
1478 }
1479