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         /* When probing UNCONFIRMED addresses, the association overall
 434          * error count is NOT incremented
 435          */
 436         if (transport->state != SCTP_UNCONFIRMED)
 437                 asoc->overall_error_count++;
 438
 439         if (transport->state != SCTP_INACTIVE &&
 440             (transport->error_count++ >= transport->pathmaxrxt)) {
 441                 SCTP_DEBUG_PRINTK_IPADDR("transport_strike:association %p",
 442                                          " transport IP: port:%d failed.\n",
 443                                          asoc,
 444                                          (&transport->ipaddr),
 445                                          ntohs(transport->ipaddr.v4.sin_port));
 446                 sctp_assoc_control_transport(asoc, transport,
 447                                              SCTP_TRANSPORT_DOWN,
 448                                              SCTP_FAILED_THRESHOLD);
 449         }
 450
 451         /* E2) For the destination address for which the timer
 452          * expires, set RTO <- RTO * 2 ("back off the timer").  The
 453          * maximum value discussed in rule C7 above (RTO.max) may be
 454          * used to provide an upper bound to this doubling operation.
 455          */
 456         transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
 457 }
 458
 459 /* Worker routine to handle INIT command failure.  */
 460 static void sctp_cmd_init_failed(sctp_cmd_seq_t *commands,
 461                                  struct sctp_association *asoc,
 462                                  unsigned error)
 463 {
 464         struct sctp_ulpevent *event;
 465
 466         event = sctp_ulpevent_make_assoc_change(asoc,0, SCTP_CANT_STR_ASSOC,
 467                                                 (__u16)error, 0, 0,
 468                                                 GFP_ATOMIC);
 469
 470         if (event)
 471                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 472                                 SCTP_ULPEVENT(event));
 473
 474         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 475                         SCTP_STATE(SCTP_STATE_CLOSED));
 476
 477         /* SEND_FAILED sent later when cleaning up the association. */
 478         asoc->outqueue.error = error;
 479         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 480 }
 481
 482 /* Worker routine to handle SCTP_CMD_ASSOC_FAILED.  */
 483 static void sctp_cmd_assoc_failed(sctp_cmd_seq_t *commands,
 484                                   struct sctp_association *asoc,
 485                                   sctp_event_t event_type,
 486                                   sctp_subtype_t subtype,
 487                                   struct sctp_chunk *chunk,
 488                                   unsigned error)
 489 {
 490         struct sctp_ulpevent *event;
 491
 492         /* Cancel any partial delivery in progress. */
 493         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
 494
 495         event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
 496                                                 (__u16)error, 0, 0,
 497                                                 GFP_ATOMIC);
 498         if (event)
 499                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 500                                 SCTP_ULPEVENT(event));
 501
 502         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 503                         SCTP_STATE(SCTP_STATE_CLOSED));
 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) || (t->state == SCTP_UNCONFIRMED))
 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         /* Update the heartbeat timer.  */
 629         if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 630                 sctp_transport_hold(t);
 631 }
 632
 633 /* Helper function to do a transport reset at the expiry of the hearbeat
 634  * timer.
 635  */
 636 static void sctp_cmd_transport_reset(sctp_cmd_seq_t *cmds,
 637                                      struct sctp_association *asoc,
 638                                      struct sctp_transport *t)
 639 {
 640         sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
 641
 642         /* Mark one strike against a transport.  */
 643         sctp_do_8_2_transport_strike(asoc, t);
 644 }
 645
 646 /* Helper function to process the process SACK command.  */
 647 static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds,
 648                                  struct sctp_association *asoc,
 649                                  struct sctp_sackhdr *sackh)
 650 {
 651         int err;
 652
 653         if (sctp_outq_sack(&asoc->outqueue, sackh)) {
 654                 /* There are no more TSNs awaiting SACK.  */
 655                 err = sctp_do_sm(SCTP_EVENT_T_OTHER,
 656                                  SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
 657                                  asoc->state, asoc->ep, asoc, NULL,
 658                                  GFP_ATOMIC);
 659         } else {
 660                 /* Windows may have opened, so we need
 661                  * to check if we have DATA to transmit
 662                  */
 663                 err = sctp_outq_flush(&asoc->outqueue, 0);
 664         }
 665
 666         return err;
 667 }
 668
 669 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
 670  * the transport for a shutdown chunk.
 671  */
 672 static void sctp_cmd_setup_t2(sctp_cmd_seq_t *cmds,
 673                               struct sctp_association *asoc,
 674                               struct sctp_chunk *chunk)
 675 {
 676         struct sctp_transport *t;
 677
 678         t = sctp_assoc_choose_shutdown_transport(asoc);
 679         asoc->shutdown_last_sent_to = t;
 680         asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
 681         chunk->transport = t;
 682 }
 683
 684 /* Helper function to change the state of an association. */
 685 static void sctp_cmd_new_state(sctp_cmd_seq_t *cmds,
 686                                struct sctp_association *asoc,
 687                                sctp_state_t state)
 688 {
 689         struct sock *sk = asoc->base.sk;
 690
 691         asoc->state = state;
 692
 693         SCTP_DEBUG_PRINTK("sctp_cmd_new_state: asoc %p[%s]\n",
 694                           asoc, sctp_state_tbl[state]);
 695
 696         if (sctp_style(sk, TCP)) {
 697                 /* Change the sk->sk_state of a TCP-style socket that has
 698                  * sucessfully completed a connect() call.
 699                  */
 700                 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
 701                         sk->sk_state = SCTP_SS_ESTABLISHED;
 702
 703                 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
 704                 if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
 705                     sctp_sstate(sk, ESTABLISHED))
 706                         sk->sk_shutdown |= RCV_SHUTDOWN;
 707         }
 708
 709         if (sctp_state(asoc, COOKIE_WAIT)) {
 710                 /* Reset init timeouts since they may have been
 711                  * increased due to timer expirations.
 712                  */
 713                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
 714                                                 asoc->rto_initial;
 715                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
 716                                                 asoc->rto_initial;
 717         }
 718
 719         if (sctp_state(asoc, ESTABLISHED) ||
 720             sctp_state(asoc, CLOSED) ||
 721             sctp_state(asoc, SHUTDOWN_RECEIVED)) {
 722                 /* Wake up any processes waiting in the asoc's wait queue in
 723                  * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
 724                  */
 725                 if (waitqueue_active(&asoc->wait))
 726                         wake_up_interruptible(&asoc->wait);
 727
 728                 /* Wake up any processes waiting in the sk's sleep queue of
 729                  * a TCP-style or UDP-style peeled-off socket in
 730                  * sctp_wait_for_accept() or sctp_wait_for_packet().
 731                  * For a UDP-style socket, the waiters are woken up by the
 732                  * notifications.
 733                  */
 734                 if (!sctp_style(sk, UDP))
 735                         sk->sk_state_change(sk);
 736         }
 737 }
 738
 739 /* Helper function to delete an association. */
 740 static void sctp_cmd_delete_tcb(sctp_cmd_seq_t *cmds,
 741                                 struct sctp_association *asoc)
 742 {
 743         struct sock *sk = asoc->base.sk;
 744
 745         /* If it is a non-temporary association belonging to a TCP-style
 746          * listening socket that is not closed, do not free it so that accept()
 747          * can pick it up later.
 748          */
 749         if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
 750             (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
 751                 return;
 752
 753         sctp_unhash_established(asoc);
 754         sctp_association_free(asoc);
 755 }
 756
 757 /*
 758  * ADDIP Section 4.1 ASCONF Chunk Procedures
 759  * A4) Start a T-4 RTO timer, using the RTO value of the selected
 760  * destination address (we use active path instead of primary path just
 761  * because primary path may be inactive.
 762  */
 763 static void sctp_cmd_setup_t4(sctp_cmd_seq_t *cmds,
 764                                 struct sctp_association *asoc,
 765                                 struct sctp_chunk *chunk)
 766 {
 767         struct sctp_transport *t;
 768
 769         t = asoc->peer.active_path;
 770         asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
 771         chunk->transport = t;
 772 }
 773
 774 /* Process an incoming Operation Error Chunk. */
 775 static void sctp_cmd_process_operr(sctp_cmd_seq_t *cmds,
 776                                    struct sctp_association *asoc,
 777                                    struct sctp_chunk *chunk)
 778 {
 779         struct sctp_operr_chunk *operr_chunk;
 780         struct sctp_errhdr *err_hdr;
 781
 782         operr_chunk = (struct sctp_operr_chunk *)chunk->chunk_hdr;
 783         err_hdr = &operr_chunk->err_hdr;
 784
 785         switch (err_hdr->cause) {
 786         case SCTP_ERROR_UNKNOWN_CHUNK:
 787         {
 788                 struct sctp_chunkhdr *unk_chunk_hdr;
 789
 790                 unk_chunk_hdr = (struct sctp_chunkhdr *)err_hdr->variable;
 791                 switch (unk_chunk_hdr->type) {
 792                 /* ADDIP 4.1 A9) If the peer responds to an ASCONF with an
 793                  * ERROR chunk reporting that it did not recognized the ASCONF
 794                  * chunk type, the sender of the ASCONF MUST NOT send any
 795                  * further ASCONF chunks and MUST stop its T-4 timer.
 796                  */
 797                 case SCTP_CID_ASCONF:
 798                         asoc->peer.asconf_capable = 0;
 799                         sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
 800                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
 801                         break;
 802                 default:
 803                         break;
 804                 }
 805                 break;
 806         }
 807         default:
 808                 break;
 809         }
 810 }
 811
 812 /* Process variable FWDTSN chunk information. */
 813 static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq,
 814                                     struct sctp_chunk *chunk)
 815 {
 816         struct sctp_fwdtsn_skip *skip;
 817         /* Walk through all the skipped SSNs */
 818         sctp_walk_fwdtsn(skip, chunk) {
 819                 sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
 820         }
 821
 822         return;
 823 }
 824
 825 /* Helper function to remove the association non-primary peer
 826  * transports.
 827  */
 828 static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
 829 {
 830         struct sctp_transport *t;
 831         struct list_head *pos;
 832         struct list_head *temp;
 833
 834         list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
 835                 t = list_entry(pos, struct sctp_transport, transports);
 836                 if (!sctp_cmp_addr_exact(&t->ipaddr,
 837                                          &asoc->peer.primary_addr)) {
 838                         sctp_assoc_del_peer(asoc, &t->ipaddr);
 839                 }
 840         }
 841
 842         return;
 843 }
 844
 845 /* Helper function to set sk_err on a 1-1 style socket. */
 846 static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
 847 {
 848         struct sock *sk = asoc->base.sk;
 849
 850         if (!sctp_style(sk, UDP))
 851                 sk->sk_err = error;
 852 }
 853
 854 /* These three macros allow us to pull the debugging code out of the
 855  * main flow of sctp_do_sm() to keep attention focused on the real
 856  * functionality there.
 857  */
 858 #define DEBUG_PRE \
 859         SCTP_DEBUG_PRINTK("sctp_do_sm prefn: " \
 860                           "ep %p, %s, %s, asoc %p[%s], %s\n", \
 861                           ep, sctp_evttype_tbl[event_type], \
 862                           (*debug_fn)(subtype), asoc, \
 863                           sctp_state_tbl[state], state_fn->name)
 864
 865 #define DEBUG_POST \
 866         SCTP_DEBUG_PRINTK("sctp_do_sm postfn: " \
 867                           "asoc %p, status: %s\n", \
 868                           asoc, sctp_status_tbl[status])
 869
 870 #define DEBUG_POST_SFX \
 871         SCTP_DEBUG_PRINTK("sctp_do_sm post sfx: error %d, asoc %p[%s]\n", \
 872                           error, asoc, \
 873                           sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
 874                           sctp_assoc2id(asoc)))?asoc->state:SCTP_STATE_CLOSED])
 875
 876 /*
 877  * This is the master state machine processing function.
 878  *
 879  * If you want to understand all of lksctp, this is a
 880  * good place to start.
 881  */
 882 int sctp_do_sm(sctp_event_t event_type, sctp_subtype_t subtype,
 883                sctp_state_t state,
 884                struct sctp_endpoint *ep,
 885                struct sctp_association *asoc,
 886                void *event_arg,
 887                gfp_t gfp)
 888 {
 889         sctp_cmd_seq_t commands;
 890         const sctp_sm_table_entry_t *state_fn;
 891         sctp_disposition_t status;
 892         int error = 0;
 893         typedef const char *(printfn_t)(sctp_subtype_t);
 894
 895         static printfn_t *table[] = {
 896                 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
 897         };
 898         printfn_t *debug_fn  __attribute__ ((unused)) = table[event_type];
 899
 900         /* Look up the state function, run it, and then process the
 901          * side effects.  These three steps are the heart of lksctp.
 902          */
 903         state_fn = sctp_sm_lookup_event(event_type, state, subtype);
 904
 905         sctp_init_cmd_seq(&commands);
 906
 907         DEBUG_PRE;
 908         status = (*state_fn->fn)(ep, asoc, subtype, event_arg, &commands);
 909         DEBUG_POST;
 910
 911         error = sctp_side_effects(event_type, subtype, state,
 912                                   ep, asoc, event_arg, status,
 913                                   &commands, gfp);
 914         DEBUG_POST_SFX;
 915
 916         return error;
 917 }
 918
 919 #undef DEBUG_PRE
 920 #undef DEBUG_POST
 921
 922 /*****************************************************************
 923  * This the master state function side effect processing function.
 924  *****************************************************************/
 925 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
 926                              sctp_state_t state,
 927                              struct sctp_endpoint *ep,
 928                              struct sctp_association *asoc,
 929                              void *event_arg,
 930                              sctp_disposition_t status,
 931                              sctp_cmd_seq_t *commands,
 932                              gfp_t gfp)
 933 {
 934         int error;
 935
 936         /* FIXME - Most of the dispositions left today would be categorized
 937          * as "exceptional" dispositions.  For those dispositions, it
 938          * may not be proper to run through any of the commands at all.
 939          * For example, the command interpreter might be run only with
 940          * disposition SCTP_DISPOSITION_CONSUME.
 941          */
 942         if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
 943                                                ep, asoc,
 944                                                event_arg, status,
 945                                                commands, gfp)))
 946                 goto bail;
 947
 948         switch (status) {
 949         case SCTP_DISPOSITION_DISCARD:
 950                 SCTP_DEBUG_PRINTK("Ignored sctp protocol event - state %d, "
 951                                   "event_type %d, event_id %d\n",
 952                                   state, event_type, subtype.chunk);
 953                 break;
 954
 955         case SCTP_DISPOSITION_NOMEM:
 956                 /* We ran out of memory, so we need to discard this
 957                  * packet.
 958                  */
 959                 /* BUG--we should now recover some memory, probably by
 960                  * reneging...
 961                  */
 962                 error = -ENOMEM;
 963                 break;
 964
 965         case SCTP_DISPOSITION_DELETE_TCB:
 966                 /* This should now be a command. */
 967                 break;
 968
 969         case SCTP_DISPOSITION_CONSUME:
 970         case SCTP_DISPOSITION_ABORT:
 971                 /*
 972                  * We should no longer have much work to do here as the
 973                  * real work has been done as explicit commands above.
 974                  */
 975                 break;
 976
 977         case SCTP_DISPOSITION_VIOLATION:
 978                 printk(KERN_ERR "sctp protocol violation state %d "
 979                        "chunkid %d\n", state, subtype.chunk);
 980                 break;
 981
 982         case SCTP_DISPOSITION_NOT_IMPL:
 983                 printk(KERN_WARNING "sctp unimplemented feature in state %d, "
 984                        "event_type %d, event_id %d\n",
 985                        state, event_type, subtype.chunk);
 986                 break;
 987
 988         case SCTP_DISPOSITION_BUG:
 989                 printk(KERN_ERR "sctp bug in state %d, "
 990                        "event_type %d, event_id %d\n",
 991                        state, event_type, subtype.chunk);
 992                 BUG();
 993                 break;
 994
 995         default:
 996                 printk(KERN_ERR "sctp impossible disposition %d "
 997                        "in state %d, event_type %d, event_id %d\n",
 998                        status, state, event_type, subtype.chunk);
 999                 BUG();
1000                 break;
1001         };
1002
1003 bail:
1004         return error;
1005 }
1006
1007 /********************************************************************
1008  * 2nd Level Abstractions
1009  ********************************************************************/
1010
1011 /* This is the side-effect interpreter.  */
1012 static int sctp_cmd_interpreter(sctp_event_t event_type,
1013                                 sctp_subtype_t subtype,
1014                                 sctp_state_t state,
1015                                 struct sctp_endpoint *ep,
1016                                 struct sctp_association *asoc,
1017                                 void *event_arg,
1018                                 sctp_disposition_t status,
1019                                 sctp_cmd_seq_t *commands,
1020                                 gfp_t gfp)
1021 {
1022         int error = 0;
1023         int force;
1024         sctp_cmd_t *cmd;
1025         struct sctp_chunk *new_obj;
1026         struct sctp_chunk *chunk = NULL;
1027         struct sctp_packet *packet;
1028         struct list_head *pos;
1029         struct timer_list *timer;
1030         unsigned long timeout;
1031         struct sctp_transport *t;
1032         struct sctp_sackhdr sackh;
1033         int local_cork = 0;
1034
1035         if (SCTP_EVENT_T_TIMEOUT != event_type)
1036                 chunk = (struct sctp_chunk *) event_arg;
1037
1038         /* Note:  This whole file is a huge candidate for rework.
1039          * For example, each command could either have its own handler, so
1040          * the loop would look like:
1041          *     while (cmds)
1042          *         cmd->handle(x, y, z)
1043          * --jgrimm
1044          */
1045         while (NULL != (cmd = sctp_next_cmd(commands))) {
1046                 switch (cmd->verb) {
1047                 case SCTP_CMD_NOP:
1048                         /* Do nothing. */
1049                         break;
1050
1051                 case SCTP_CMD_NEW_ASOC:
1052                         /* Register a new association.  */
1053                         if (local_cork) {
1054                                 sctp_outq_uncork(&asoc->outqueue);
1055                                 local_cork = 0;
1056                         }
1057                         asoc = cmd->obj.ptr;
1058                         /* Register with the endpoint.  */
1059                         sctp_endpoint_add_asoc(ep, asoc);
1060                         sctp_hash_established(asoc);
1061                         break;
1062
1063                 case SCTP_CMD_UPDATE_ASSOC:
1064                        sctp_assoc_update(asoc, cmd->obj.ptr);
1065                        break;
1066
1067                 case SCTP_CMD_PURGE_OUTQUEUE:
1068                        sctp_outq_teardown(&asoc->outqueue);
1069                        break;
1070
1071                 case SCTP_CMD_DELETE_TCB:
1072                         if (local_cork) {
1073                                 sctp_outq_uncork(&asoc->outqueue);
1074                                 local_cork = 0;
1075                         }
1076                         /* Delete the current association.  */
1077                         sctp_cmd_delete_tcb(commands, asoc);
1078                         asoc = NULL;
1079                         break;
1080
1081                 case SCTP_CMD_NEW_STATE:
1082                         /* Enter a new state.  */
1083                         sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1084                         break;
1085
1086                 case SCTP_CMD_REPORT_TSN:
1087                         /* Record the arrival of a TSN.  */
1088                         sctp_tsnmap_mark(&asoc->peer.tsn_map, cmd->obj.u32);
1089                         break;
1090
1091                 case SCTP_CMD_REPORT_FWDTSN:
1092                         /* Move the Cumulattive TSN Ack ahead. */
1093                         sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32);
1094
1095                         /* Abort any in progress partial delivery. */
1096                         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
1097                         break;
1098
1099                 case SCTP_CMD_PROCESS_FWDTSN:
1100                         sctp_cmd_process_fwdtsn(&asoc->ulpq, cmd->obj.ptr);
1101                         break;
1102
1103                 case SCTP_CMD_GEN_SACK:
1104                         /* Generate a Selective ACK.
1105                          * The argument tells us whether to just count
1106                          * the packet and MAYBE generate a SACK, or
1107                          * force a SACK out.
1108                          */
1109                         force = cmd->obj.i32;
1110                         error = sctp_gen_sack(asoc, force, commands);
1111                         break;
1112
1113                 case SCTP_CMD_PROCESS_SACK:
1114                         /* Process an inbound SACK.  */
1115                         error = sctp_cmd_process_sack(commands, asoc,
1116                                                       cmd->obj.ptr);
1117                         break;
1118
1119                 case SCTP_CMD_GEN_INIT_ACK:
1120                         /* Generate an INIT ACK chunk.  */
1121                         new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1122                                                      0);
1123                         if (!new_obj)
1124                                 goto nomem;
1125
1126                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1127                                         SCTP_CHUNK(new_obj));
1128                         break;
1129
1130                 case SCTP_CMD_PEER_INIT:
1131                         /* Process a unified INIT from the peer.
1132                          * Note: Only used during INIT-ACK processing.  If
1133                          * there is an error just return to the outter
1134                          * layer which will bail.
1135                          */
1136                         error = sctp_cmd_process_init(commands, asoc, chunk,
1137                                                       cmd->obj.ptr, gfp);
1138                         break;
1139
1140                 case SCTP_CMD_GEN_COOKIE_ECHO:
1141                         /* Generate a COOKIE ECHO chunk.  */
1142                         new_obj = sctp_make_cookie_echo(asoc, chunk);
1143                         if (!new_obj) {
1144                                 if (cmd->obj.ptr)
1145                                         sctp_chunk_free(cmd->obj.ptr);
1146                                 goto nomem;
1147                         }
1148                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1149                                         SCTP_CHUNK(new_obj));
1150
1151                         /* If there is an ERROR chunk to be sent along with
1152                          * the COOKIE_ECHO, send it, too.
1153                          */
1154                         if (cmd->obj.ptr)
1155                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1156                                                 SCTP_CHUNK(cmd->obj.ptr));
1157
1158                         /* FIXME - Eventually come up with a cleaner way to
1159                          * enabling COOKIE-ECHO + DATA bundling during
1160                          * multihoming stale cookie scenarios, the following
1161                          * command plays with asoc->peer.retran_path to
1162                          * avoid the problem of sending the COOKIE-ECHO and
1163                          * DATA in different paths, which could result
1164                          * in the association being ABORTed if the DATA chunk
1165                          * is processed first by the server.  Checking the
1166                          * init error counter simply causes this command
1167                          * to be executed only during failed attempts of
1168                          * association establishment.
1169                          */
1170                         if ((asoc->peer.retran_path !=
1171                              asoc->peer.primary_path) &&
1172                             (asoc->init_err_counter > 0)) {
1173                                 sctp_add_cmd_sf(commands,
1174                                                 SCTP_CMD_FORCE_PRIM_RETRAN,
1175                                                 SCTP_NULL());
1176                         }
1177
1178                         break;
1179
1180                 case SCTP_CMD_GEN_SHUTDOWN:
1181                         /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1182                          * Reset error counts.
1183                          */
1184                         asoc->overall_error_count = 0;
1185
1186                         /* Generate a SHUTDOWN chunk.  */
1187                         new_obj = sctp_make_shutdown(asoc, chunk);
1188                         if (!new_obj)
1189                                 goto nomem;
1190                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1191                                         SCTP_CHUNK(new_obj));
1192                         break;
1193
1194                 case SCTP_CMD_CHUNK_ULP:
1195                         /* Send a chunk to the sockets layer.  */
1196                         SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1197                                           "chunk_up:", cmd->obj.ptr,
1198                                           "ulpq:", &asoc->ulpq);
1199                         sctp_ulpq_tail_data(&asoc->ulpq, cmd->obj.ptr,
1200                                             GFP_ATOMIC);
1201                         break;
1202
1203                 case SCTP_CMD_EVENT_ULP:
1204                         /* Send a notification to the sockets layer.  */
1205                         SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1206                                           "event_up:",cmd->obj.ptr,
1207                                           "ulpq:",&asoc->ulpq);
1208                         sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ptr);
1209                         break;
1210
1211                 case SCTP_CMD_REPLY:
1212                         /* If an caller has not already corked, do cork. */
1213                         if (!asoc->outqueue.cork) {
1214                                 sctp_outq_cork(&asoc->outqueue);
1215                                 local_cork = 1;
1216                         }
1217                         /* Send a chunk to our peer.  */
1218                         error = sctp_outq_tail(&asoc->outqueue, cmd->obj.ptr);
1219                         break;
1220
1221                 case SCTP_CMD_SEND_PKT:
1222                         /* Send a full packet to our peer.  */
1223                         packet = cmd->obj.ptr;
1224                         sctp_packet_transmit(packet);
1225                         sctp_ootb_pkt_free(packet);
1226                         break;
1227
1228                 case SCTP_CMD_RETRAN:
1229                         /* Mark a transport for retransmission.  */
1230                         sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1231                                         SCTP_RTXR_T3_RTX);
1232                         break;
1233
1234                 case SCTP_CMD_TRANSMIT:
1235                         /* Kick start transmission. */
1236                         error = sctp_outq_uncork(&asoc->outqueue);
1237                         local_cork = 0;
1238                         break;
1239
1240                 case SCTP_CMD_ECN_CE:
1241                         /* Do delayed CE processing.   */
1242                         sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1243                         break;
1244
1245                 case SCTP_CMD_ECN_ECNE:
1246                         /* Do delayed ECNE processing. */
1247                         new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1248                                                         chunk);
1249                         if (new_obj)
1250                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1251                                                 SCTP_CHUNK(new_obj));
1252                         break;
1253
1254                 case SCTP_CMD_ECN_CWR:
1255                         /* Do delayed CWR processing.  */
1256                         sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1257                         break;
1258
1259                 case SCTP_CMD_SETUP_T2:
1260                         sctp_cmd_setup_t2(commands, asoc, cmd->obj.ptr);
1261                         break;
1262
1263                 case SCTP_CMD_TIMER_START:
1264                         timer = &asoc->timers[cmd->obj.to];
1265                         timeout = asoc->timeouts[cmd->obj.to];
1266                         BUG_ON(!timeout);
1267
1268                         timer->expires = jiffies + timeout;
1269                         sctp_association_hold(asoc);
1270                         add_timer(timer);
1271                         break;
1272
1273                 case SCTP_CMD_TIMER_RESTART:
1274                         timer = &asoc->timers[cmd->obj.to];
1275                         timeout = asoc->timeouts[cmd->obj.to];
1276                         if (!mod_timer(timer, jiffies + timeout))
1277                                 sctp_association_hold(asoc);
1278                         break;
1279
1280                 case SCTP_CMD_TIMER_STOP:
1281                         timer = &asoc->timers[cmd->obj.to];
1282                         if (timer_pending(timer) && del_timer(timer))
1283                                 sctp_association_put(asoc);
1284                         break;
1285
1286                 case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1287                         chunk = cmd->obj.ptr;
1288                         t = sctp_assoc_choose_init_transport(asoc);
1289                         asoc->init_last_sent_to = t;
1290                         chunk->transport = t;
1291                         t->init_sent_count++;
1292                         break;
1293
1294                 case SCTP_CMD_INIT_RESTART:
1295                         /* Do the needed accounting and updates
1296                          * associated with restarting an initialization
1297                          * timer. Only multiply the timeout by two if
1298                          * all transports have been tried at the current
1299                          * timeout.
1300                          */
1301                         t = asoc->init_last_sent_to;
1302                         asoc->init_err_counter++;
1303
1304                         if (t->init_sent_count > (asoc->init_cycle + 1)) {
1305                                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] *= 2;
1306                                 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] >
1307                                     asoc->max_init_timeo) {
1308                                         asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
1309                                                 asoc->max_init_timeo;
1310                                 }
1311                                 asoc->init_cycle++;
1312                                 SCTP_DEBUG_PRINTK(
1313                                         "T1 INIT Timeout adjustment"
1314                                         " init_err_counter: %d"
1315                                         " cycle: %d"
1316                                         " timeout: %ld\n",
1317                                         asoc->init_err_counter,
1318                                         asoc->init_cycle,
1319                                         asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT]);
1320                         }
1321
1322                         sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1323                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1324                         break;
1325
1326                 case SCTP_CMD_COOKIEECHO_RESTART:
1327                         /* Do the needed accounting and updates
1328                          * associated with restarting an initialization
1329                          * timer. Only multiply the timeout by two if
1330                          * all transports have been tried at the current
1331                          * timeout.
1332                          */
1333                         asoc->init_err_counter++;
1334
1335                         asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] *= 2;
1336                         if (asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] >
1337                             asoc->max_init_timeo) {
1338                                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
1339                                         asoc->max_init_timeo;
1340                         }
1341                         SCTP_DEBUG_PRINTK(
1342                                 "T1 COOKIE Timeout adjustment"
1343                                 " init_err_counter: %d"
1344                                 " timeout: %ld\n",
1345                                 asoc->init_err_counter,
1346                                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE]);
1347
1348                         /* If we've sent any data bundled with
1349                          * COOKIE-ECHO we need to resend.
1350                          */
1351                         list_for_each(pos, &asoc->peer.transport_addr_list) {
1352                                 t = list_entry(pos, struct sctp_transport,
1353                                                transports);
1354                                 sctp_retransmit_mark(&asoc->outqueue, t, 0);
1355                         }
1356
1357                         sctp_add_cmd_sf(commands,
1358                                         SCTP_CMD_TIMER_RESTART,
1359                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1360                         break;
1361
1362                 case SCTP_CMD_INIT_FAILED:
1363                         sctp_cmd_init_failed(commands, asoc, cmd->obj.err);
1364                         break;
1365
1366                 case SCTP_CMD_ASSOC_FAILED:
1367                         sctp_cmd_assoc_failed(commands, asoc, event_type,
1368                                               subtype, chunk, cmd->obj.err);
1369                         break;
1370
1371                 case SCTP_CMD_INIT_COUNTER_INC:
1372                         asoc->init_err_counter++;
1373                         break;
1374
1375                 case SCTP_CMD_INIT_COUNTER_RESET:
1376                         asoc->init_err_counter = 0;
1377                         asoc->init_cycle = 0;
1378                         break;
1379
1380                 case SCTP_CMD_REPORT_DUP:
1381                         sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1382                                              cmd->obj.u32);
1383                         break;
1384
1385                 case SCTP_CMD_REPORT_BAD_TAG:
1386                         SCTP_DEBUG_PRINTK("vtag mismatch!\n");
1387                         break;
1388
1389                 case SCTP_CMD_STRIKE:
1390                         /* Mark one strike against a transport.  */
1391                         sctp_do_8_2_transport_strike(asoc, cmd->obj.transport);
1392                         break;
1393
1394                 case SCTP_CMD_TRANSPORT_RESET:
1395                         t = cmd->obj.transport;
1396                         sctp_cmd_transport_reset(commands, asoc, t);
1397                         break;
1398
1399                 case SCTP_CMD_TRANSPORT_ON:
1400                         t = cmd->obj.transport;
1401                         sctp_cmd_transport_on(commands, asoc, t, chunk);
1402                         break;
1403
1404                 case SCTP_CMD_HB_TIMERS_START:
1405                         sctp_cmd_hb_timers_start(commands, asoc);
1406                         break;
1407
1408                 case SCTP_CMD_HB_TIMER_UPDATE:
1409                         t = cmd->obj.transport;
1410                         sctp_cmd_hb_timer_update(commands, asoc, t);
1411                         break;
1412
1413                 case SCTP_CMD_HB_TIMERS_STOP:
1414                         sctp_cmd_hb_timers_stop(commands, asoc);
1415                         break;
1416
1417                 case SCTP_CMD_REPORT_ERROR:
1418                         error = cmd->obj.error;
1419                         break;
1420
1421                 case SCTP_CMD_PROCESS_CTSN:
1422                         /* Dummy up a SACK for processing. */
1423                         sackh.cum_tsn_ack = cmd->obj.be32;
1424                         sackh.a_rwnd = 0;
1425                         sackh.num_gap_ack_blocks = 0;
1426                         sackh.num_dup_tsns = 0;
1427                         sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1428                                         SCTP_SACKH(&sackh));
1429                         break;
1430
1431                 case SCTP_CMD_DISCARD_PACKET:
1432                         /* We need to discard the whole packet.  */
1433                         chunk->pdiscard = 1;
1434                         break;
1435
1436                 case SCTP_CMD_RTO_PENDING:
1437                         t = cmd->obj.transport;
1438                         t->rto_pending = 1;
1439                         break;
1440
1441                 case SCTP_CMD_PART_DELIVER:
1442                         sctp_ulpq_partial_delivery(&asoc->ulpq, cmd->obj.ptr,
1443                                                    GFP_ATOMIC);
1444                         break;
1445
1446                 case SCTP_CMD_RENEGE:
1447                         sctp_ulpq_renege(&asoc->ulpq, cmd->obj.ptr,
1448                                          GFP_ATOMIC);
1449                         break;
1450
1451                 case SCTP_CMD_SETUP_T4:
1452                         sctp_cmd_setup_t4(commands, asoc, cmd->obj.ptr);
1453                         break;
1454
1455                 case SCTP_CMD_PROCESS_OPERR:
1456                         sctp_cmd_process_operr(commands, asoc, chunk);
1457                         break;
1458                 case SCTP_CMD_CLEAR_INIT_TAG:
1459                         asoc->peer.i.init_tag = 0;
1460                         break;
1461                 case SCTP_CMD_DEL_NON_PRIMARY:
1462                         sctp_cmd_del_non_primary(asoc);
1463                         break;
1464                 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1465                         sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1466                         break;
1467                 case SCTP_CMD_FORCE_PRIM_RETRAN:
1468                         t = asoc->peer.retran_path;
1469                         asoc->peer.retran_path = asoc->peer.primary_path;
1470                         error = sctp_outq_uncork(&asoc->outqueue);
1471                         local_cork = 0;
1472                         asoc->peer.retran_path = t;
1473                         break;
1474                 case SCTP_CMD_SET_SK_ERR:
1475                         sctp_cmd_set_sk_err(asoc, cmd->obj.error);
1476                         break;
1477                 default:
1478                         printk(KERN_WARNING "Impossible command: %u, %p\n",
1479                                cmd->verb, cmd->obj.ptr);
1480                         break;
1481                 };
1482                 if (error)
1483                         break;
1484         }
1485
1486 out:
1487         if (local_cork)
1488                 sctp_outq_uncork(&asoc->outqueue);
1489         return error;
1490 nomem:
1491         error = -ENOMEM;
1492         goto out;
1493 }
1494