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                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(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, NULL,
 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         if (event_type == SCTP_EVENT_T_CHUNK && subtype.chunk == SCTP_CID_ABORT)
 496                 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
 497                                                 (__u16)error, 0, 0, chunk,
 498                                                 GFP_ATOMIC);
 499         else
 500                 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
 501                                                 (__u16)error, 0, 0, NULL,
 502                                                 GFP_ATOMIC);
 503         if (event)
 504                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 505                                 SCTP_ULPEVENT(event));
 506
 507         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 508                         SCTP_STATE(SCTP_STATE_CLOSED));
 509
 510         /* SEND_FAILED sent later when cleaning up the association. */
 511         asoc->outqueue.error = error;
 512         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 513 }
 514
 515 /* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
 516  * inside the cookie.  In reality, this is only used for INIT-ACK processing
 517  * since all other cases use "temporary" associations and can do all
 518  * their work in statefuns directly.
 519  */
 520 static int sctp_cmd_process_init(sctp_cmd_seq_t *commands,
 521                                  struct sctp_association *asoc,
 522                                  struct sctp_chunk *chunk,
 523                                  sctp_init_chunk_t *peer_init,
 524                                  gfp_t gfp)
 525 {
 526         int error;
 527
 528         /* We only process the init as a sideeffect in a single
 529          * case.   This is when we process the INIT-ACK.   If we
 530          * fail during INIT processing (due to malloc problems),
 531          * just return the error and stop processing the stack.
 532          */
 533         if (!sctp_process_init(asoc, chunk->chunk_hdr->type,
 534                                sctp_source(chunk), peer_init, gfp))
 535                 error = -ENOMEM;
 536         else
 537                 error = 0;
 538
 539         return error;
 540 }
 541
 542 /* Helper function to break out starting up of heartbeat timers.  */
 543 static void sctp_cmd_hb_timers_start(sctp_cmd_seq_t *cmds,
 544                                      struct sctp_association *asoc)
 545 {
 546         struct sctp_transport *t;
 547         struct list_head *pos;
 548
 549         /* Start a heartbeat timer for each transport on the association.
 550          * hold a reference on the transport to make sure none of
 551          * the needed data structures go away.
 552          */
 553         list_for_each(pos, &asoc->peer.transport_addr_list) {
 554                 t = list_entry(pos, struct sctp_transport, transports);
 555
 556                 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 557                         sctp_transport_hold(t);
 558         }
 559 }
 560
 561 static void sctp_cmd_hb_timers_stop(sctp_cmd_seq_t *cmds,
 562                                     struct sctp_association *asoc)
 563 {
 564         struct sctp_transport *t;
 565         struct list_head *pos;
 566
 567         /* Stop all heartbeat timers. */
 568
 569         list_for_each(pos, &asoc->peer.transport_addr_list) {
 570                 t = list_entry(pos, struct sctp_transport, transports);
 571                 if (del_timer(&t->hb_timer))
 572                         sctp_transport_put(t);
 573         }
 574 }
 575
 576 /* Helper function to stop any pending T3-RTX timers */
 577 static void sctp_cmd_t3_rtx_timers_stop(sctp_cmd_seq_t *cmds,
 578                                         struct sctp_association *asoc)
 579 {
 580         struct sctp_transport *t;
 581         struct list_head *pos;
 582
 583         list_for_each(pos, &asoc->peer.transport_addr_list) {
 584                 t = list_entry(pos, struct sctp_transport, transports);
 585                 if (timer_pending(&t->T3_rtx_timer) &&
 586                     del_timer(&t->T3_rtx_timer)) {
 587                         sctp_transport_put(t);
 588                 }
 589         }
 590 }
 591
 592
 593 /* Helper function to update the heartbeat timer. */
 594 static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
 595                                      struct sctp_association *asoc,
 596                                      struct sctp_transport *t)
 597 {
 598         /* Update the heartbeat timer.  */
 599         if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 600                 sctp_transport_hold(t);
 601 }
 602
 603 /* Helper function to handle the reception of an HEARTBEAT ACK.  */
 604 static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds,
 605                                   struct sctp_association *asoc,
 606                                   struct sctp_transport *t,
 607                                   struct sctp_chunk *chunk)
 608 {
 609         sctp_sender_hb_info_t *hbinfo;
 610
 611         /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
 612          * HEARTBEAT should clear the error counter of the destination
 613          * transport address to which the HEARTBEAT was sent.
 614          * The association's overall error count is also cleared.
 615          */
 616         t->error_count = 0;
 617         t->asoc->overall_error_count = 0;
 618
 619         /* Mark the destination transport address as active if it is not so
 620          * marked.
 621          */
 622         if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED))
 623                 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
 624                                              SCTP_HEARTBEAT_SUCCESS);
 625
 626         /* The receiver of the HEARTBEAT ACK should also perform an
 627          * RTT measurement for that destination transport address
 628          * using the time value carried in the HEARTBEAT ACK chunk.
 629          * If the transport's rto_pending variable has been cleared,
 630          * it was most likely due to a retransmit.  However, we want
 631          * to re-enable it to properly update the rto.
 632          */
 633         if (t->rto_pending == 0)
 634                 t->rto_pending = 1;
 635
 636         hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
 637         sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
 638
 639         /* Update the heartbeat timer.  */
 640         if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 641                 sctp_transport_hold(t);
 642 }
 643
 644 /* Helper function to do a transport reset at the expiry of the hearbeat
 645  * timer.
 646  */
 647 static void sctp_cmd_transport_reset(sctp_cmd_seq_t *cmds,
 648                                      struct sctp_association *asoc,
 649                                      struct sctp_transport *t)
 650 {
 651         sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
 652
 653         /* Mark one strike against a transport.  */
 654         sctp_do_8_2_transport_strike(asoc, t);
 655 }
 656
 657 /* Helper function to process the process SACK command.  */
 658 static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds,
 659                                  struct sctp_association *asoc,
 660                                  struct sctp_sackhdr *sackh)
 661 {
 662         int err;
 663
 664         if (sctp_outq_sack(&asoc->outqueue, sackh)) {
 665                 /* There are no more TSNs awaiting SACK.  */
 666                 err = sctp_do_sm(SCTP_EVENT_T_OTHER,
 667                                  SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
 668                                  asoc->state, asoc->ep, asoc, NULL,
 669                                  GFP_ATOMIC);
 670         } else {
 671                 /* Windows may have opened, so we need
 672                  * to check if we have DATA to transmit
 673                  */
 674                 err = sctp_outq_flush(&asoc->outqueue, 0);
 675         }
 676
 677         return err;
 678 }
 679
 680 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
 681  * the transport for a shutdown chunk.
 682  */
 683 static void sctp_cmd_setup_t2(sctp_cmd_seq_t *cmds,
 684                               struct sctp_association *asoc,
 685                               struct sctp_chunk *chunk)
 686 {
 687         struct sctp_transport *t;
 688
 689         t = sctp_assoc_choose_shutdown_transport(asoc);
 690         asoc->shutdown_last_sent_to = t;
 691         asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
 692         chunk->transport = t;
 693 }
 694
 695 /* Helper function to change the state of an association. */
 696 static void sctp_cmd_new_state(sctp_cmd_seq_t *cmds,
 697                                struct sctp_association *asoc,
 698                                sctp_state_t state)
 699 {
 700         struct sock *sk = asoc->base.sk;
 701
 702         asoc->state = state;
 703
 704         SCTP_DEBUG_PRINTK("sctp_cmd_new_state: asoc %p[%s]\n",
 705                           asoc, sctp_state_tbl[state]);
 706
 707         if (sctp_style(sk, TCP)) {
 708                 /* Change the sk->sk_state of a TCP-style socket that has
 709                  * sucessfully completed a connect() call.
 710                  */
 711                 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
 712                         sk->sk_state = SCTP_SS_ESTABLISHED;
 713
 714                 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
 715                 if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
 716                     sctp_sstate(sk, ESTABLISHED))
 717                         sk->sk_shutdown |= RCV_SHUTDOWN;
 718         }
 719
 720         if (sctp_state(asoc, COOKIE_WAIT)) {
 721                 /* Reset init timeouts since they may have been
 722                  * increased due to timer expirations.
 723                  */
 724                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
 725                                                 asoc->rto_initial;
 726                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
 727                                                 asoc->rto_initial;
 728         }
 729
 730         if (sctp_state(asoc, ESTABLISHED) ||
 731             sctp_state(asoc, CLOSED) ||
 732             sctp_state(asoc, SHUTDOWN_RECEIVED)) {
 733                 /* Wake up any processes waiting in the asoc's wait queue in
 734                  * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
 735                  */
 736                 if (waitqueue_active(&asoc->wait))
 737                         wake_up_interruptible(&asoc->wait);
 738
 739                 /* Wake up any processes waiting in the sk's sleep queue of
 740                  * a TCP-style or UDP-style peeled-off socket in
 741                  * sctp_wait_for_accept() or sctp_wait_for_packet().
 742                  * For a UDP-style socket, the waiters are woken up by the
 743                  * notifications.
 744                  */
 745                 if (!sctp_style(sk, UDP))
 746                         sk->sk_state_change(sk);
 747         }
 748 }
 749
 750 /* Helper function to delete an association. */
 751 static void sctp_cmd_delete_tcb(sctp_cmd_seq_t *cmds,
 752                                 struct sctp_association *asoc)
 753 {
 754         struct sock *sk = asoc->base.sk;
 755
 756         /* If it is a non-temporary association belonging to a TCP-style
 757          * listening socket that is not closed, do not free it so that accept()
 758          * can pick it up later.
 759          */
 760         if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
 761             (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
 762                 return;
 763
 764         sctp_unhash_established(asoc);
 765         sctp_association_free(asoc);
 766 }
 767
 768 /*
 769  * ADDIP Section 4.1 ASCONF Chunk Procedures
 770  * A4) Start a T-4 RTO timer, using the RTO value of the selected
 771  * destination address (we use active path instead of primary path just
 772  * because primary path may be inactive.
 773  */
 774 static void sctp_cmd_setup_t4(sctp_cmd_seq_t *cmds,
 775                                 struct sctp_association *asoc,
 776                                 struct sctp_chunk *chunk)
 777 {
 778         struct sctp_transport *t;
 779
 780         t = asoc->peer.active_path;
 781         asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
 782         chunk->transport = t;
 783 }
 784
 785 /* Process an incoming Operation Error Chunk. */
 786 static void sctp_cmd_process_operr(sctp_cmd_seq_t *cmds,
 787                                    struct sctp_association *asoc,
 788                                    struct sctp_chunk *chunk)
 789 {
 790         struct sctp_operr_chunk *operr_chunk;
 791         struct sctp_errhdr *err_hdr;
 792
 793         operr_chunk = (struct sctp_operr_chunk *)chunk->chunk_hdr;
 794         err_hdr = &operr_chunk->err_hdr;
 795
 796         switch (err_hdr->cause) {
 797         case SCTP_ERROR_UNKNOWN_CHUNK:
 798         {
 799                 struct sctp_chunkhdr *unk_chunk_hdr;
 800
 801                 unk_chunk_hdr = (struct sctp_chunkhdr *)err_hdr->variable;
 802                 switch (unk_chunk_hdr->type) {
 803                 /* ADDIP 4.1 A9) If the peer responds to an ASCONF with an
 804                  * ERROR chunk reporting that it did not recognized the ASCONF
 805                  * chunk type, the sender of the ASCONF MUST NOT send any
 806                  * further ASCONF chunks and MUST stop its T-4 timer.
 807                  */
 808                 case SCTP_CID_ASCONF:
 809                         asoc->peer.asconf_capable = 0;
 810                         sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
 811                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
 812                         break;
 813                 default:
 814                         break;
 815                 }
 816                 break;
 817         }
 818         default:
 819                 break;
 820         }
 821 }
 822
 823 /* Process variable FWDTSN chunk information. */
 824 static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq,
 825                                     struct sctp_chunk *chunk)
 826 {
 827         struct sctp_fwdtsn_skip *skip;
 828         /* Walk through all the skipped SSNs */
 829         sctp_walk_fwdtsn(skip, chunk) {
 830                 sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
 831         }
 832
 833         return;
 834 }
 835
 836 /* Helper function to remove the association non-primary peer
 837  * transports.
 838  */
 839 static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
 840 {
 841         struct sctp_transport *t;
 842         struct list_head *pos;
 843         struct list_head *temp;
 844
 845         list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
 846                 t = list_entry(pos, struct sctp_transport, transports);
 847                 if (!sctp_cmp_addr_exact(&t->ipaddr,
 848                                          &asoc->peer.primary_addr)) {
 849                         sctp_assoc_del_peer(asoc, &t->ipaddr);
 850                 }
 851         }
 852
 853         return;
 854 }
 855
 856 /* Helper function to set sk_err on a 1-1 style socket. */
 857 static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
 858 {
 859         struct sock *sk = asoc->base.sk;
 860
 861         if (!sctp_style(sk, UDP))
 862                 sk->sk_err = error;
 863 }
 864
 865 /* These three macros allow us to pull the debugging code out of the
 866  * main flow of sctp_do_sm() to keep attention focused on the real
 867  * functionality there.
 868  */
 869 #define DEBUG_PRE \
 870         SCTP_DEBUG_PRINTK("sctp_do_sm prefn: " \
 871                           "ep %p, %s, %s, asoc %p[%s], %s\n", \
 872                           ep, sctp_evttype_tbl[event_type], \
 873                           (*debug_fn)(subtype), asoc, \
 874                           sctp_state_tbl[state], state_fn->name)
 875
 876 #define DEBUG_POST \
 877         SCTP_DEBUG_PRINTK("sctp_do_sm postfn: " \
 878                           "asoc %p, status: %s\n", \
 879                           asoc, sctp_status_tbl[status])
 880
 881 #define DEBUG_POST_SFX \
 882         SCTP_DEBUG_PRINTK("sctp_do_sm post sfx: error %d, asoc %p[%s]\n", \
 883                           error, asoc, \
 884                           sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
 885                           sctp_assoc2id(asoc)))?asoc->state:SCTP_STATE_CLOSED])
 886
 887 /*
 888  * This is the master state machine processing function.
 889  *
 890  * If you want to understand all of lksctp, this is a
 891  * good place to start.
 892  */
 893 int sctp_do_sm(sctp_event_t event_type, sctp_subtype_t subtype,
 894                sctp_state_t state,
 895                struct sctp_endpoint *ep,
 896                struct sctp_association *asoc,
 897                void *event_arg,
 898                gfp_t gfp)
 899 {
 900         sctp_cmd_seq_t commands;
 901         const sctp_sm_table_entry_t *state_fn;
 902         sctp_disposition_t status;
 903         int error = 0;
 904         typedef const char *(printfn_t)(sctp_subtype_t);
 905
 906         static printfn_t *table[] = {
 907                 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
 908         };
 909         printfn_t *debug_fn  __attribute__ ((unused)) = table[event_type];
 910
 911         /* Look up the state function, run it, and then process the
 912          * side effects.  These three steps are the heart of lksctp.
 913          */
 914         state_fn = sctp_sm_lookup_event(event_type, state, subtype);
 915
 916         sctp_init_cmd_seq(&commands);
 917
 918         DEBUG_PRE;
 919         status = (*state_fn->fn)(ep, asoc, subtype, event_arg, &commands);
 920         DEBUG_POST;
 921
 922         error = sctp_side_effects(event_type, subtype, state,
 923                                   ep, asoc, event_arg, status,
 924                                   &commands, gfp);
 925         DEBUG_POST_SFX;
 926
 927         return error;
 928 }
 929
 930 #undef DEBUG_PRE
 931 #undef DEBUG_POST
 932
 933 /*****************************************************************
 934  * This the master state function side effect processing function.
 935  *****************************************************************/
 936 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
 937                              sctp_state_t state,
 938                              struct sctp_endpoint *ep,
 939                              struct sctp_association *asoc,
 940                              void *event_arg,
 941                              sctp_disposition_t status,
 942                              sctp_cmd_seq_t *commands,
 943                              gfp_t gfp)
 944 {
 945         int error;
 946
 947         /* FIXME - Most of the dispositions left today would be categorized
 948          * as "exceptional" dispositions.  For those dispositions, it
 949          * may not be proper to run through any of the commands at all.
 950          * For example, the command interpreter might be run only with
 951          * disposition SCTP_DISPOSITION_CONSUME.
 952          */
 953         if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
 954                                                ep, asoc,
 955                                                event_arg, status,
 956                                                commands, gfp)))
 957                 goto bail;
 958
 959         switch (status) {
 960         case SCTP_DISPOSITION_DISCARD:
 961                 SCTP_DEBUG_PRINTK("Ignored sctp protocol event - state %d, "
 962                                   "event_type %d, event_id %d\n",
 963                                   state, event_type, subtype.chunk);
 964                 break;
 965
 966         case SCTP_DISPOSITION_NOMEM:
 967                 /* We ran out of memory, so we need to discard this
 968                  * packet.
 969                  */
 970                 /* BUG--we should now recover some memory, probably by
 971                  * reneging...
 972                  */
 973                 error = -ENOMEM;
 974                 break;
 975
 976         case SCTP_DISPOSITION_DELETE_TCB:
 977                 /* This should now be a command. */
 978                 break;
 979
 980         case SCTP_DISPOSITION_CONSUME:
 981         case SCTP_DISPOSITION_ABORT:
 982                 /*
 983                  * We should no longer have much work to do here as the
 984                  * real work has been done as explicit commands above.
 985                  */
 986                 break;
 987
 988         case SCTP_DISPOSITION_VIOLATION:
 989                 printk(KERN_ERR "sctp protocol violation state %d "
 990                        "chunkid %d\n", state, subtype.chunk);
 991                 break;
 992
 993         case SCTP_DISPOSITION_NOT_IMPL:
 994                 printk(KERN_WARNING "sctp unimplemented feature in state %d, "
 995                        "event_type %d, event_id %d\n",
 996                        state, event_type, subtype.chunk);
 997                 break;
 998
 999         case SCTP_DISPOSITION_BUG:
1000                 printk(KERN_ERR "sctp bug in state %d, "
1001                        "event_type %d, event_id %d\n",
1002                        state, event_type, subtype.chunk);
1003                 BUG();
1004                 break;
1005
1006         default:
1007                 printk(KERN_ERR "sctp impossible disposition %d "
1008                        "in state %d, event_type %d, event_id %d\n",
1009                        status, state, event_type, subtype.chunk);
1010                 BUG();
1011                 break;
1012         }
1013
1014 bail:
1015         return error;
1016 }
1017
1018 /********************************************************************
1019  * 2nd Level Abstractions
1020  ********************************************************************/
1021
1022 /* This is the side-effect interpreter.  */
1023 static int sctp_cmd_interpreter(sctp_event_t event_type,
1024                                 sctp_subtype_t subtype,
1025                                 sctp_state_t state,
1026                                 struct sctp_endpoint *ep,
1027                                 struct sctp_association *asoc,
1028                                 void *event_arg,
1029                                 sctp_disposition_t status,
1030                                 sctp_cmd_seq_t *commands,
1031                                 gfp_t gfp)
1032 {
1033         int error = 0;
1034         int force;
1035         sctp_cmd_t *cmd;
1036         struct sctp_chunk *new_obj;
1037         struct sctp_chunk *chunk = NULL;
1038         struct sctp_packet *packet;
1039         struct list_head *pos;
1040         struct timer_list *timer;
1041         unsigned long timeout;
1042         struct sctp_transport *t;
1043         struct sctp_sackhdr sackh;
1044         int local_cork = 0;
1045
1046         if (SCTP_EVENT_T_TIMEOUT != event_type)
1047                 chunk = (struct sctp_chunk *) event_arg;
1048
1049         /* Note:  This whole file is a huge candidate for rework.
1050          * For example, each command could either have its own handler, so
1051          * the loop would look like:
1052          *     while (cmds)
1053          *         cmd->handle(x, y, z)
1054          * --jgrimm
1055          */
1056         while (NULL != (cmd = sctp_next_cmd(commands))) {
1057                 switch (cmd->verb) {
1058                 case SCTP_CMD_NOP:
1059                         /* Do nothing. */
1060                         break;
1061
1062                 case SCTP_CMD_NEW_ASOC:
1063                         /* Register a new association.  */
1064                         if (local_cork) {
1065                                 sctp_outq_uncork(&asoc->outqueue);
1066                                 local_cork = 0;
1067                         }
1068                         asoc = cmd->obj.ptr;
1069                         /* Register with the endpoint.  */
1070                         sctp_endpoint_add_asoc(ep, asoc);
1071                         sctp_hash_established(asoc);
1072                         break;
1073
1074                 case SCTP_CMD_UPDATE_ASSOC:
1075                        sctp_assoc_update(asoc, cmd->obj.ptr);
1076                        break;
1077
1078                 case SCTP_CMD_PURGE_OUTQUEUE:
1079                        sctp_outq_teardown(&asoc->outqueue);
1080                        break;
1081
1082                 case SCTP_CMD_DELETE_TCB:
1083                         if (local_cork) {
1084                                 sctp_outq_uncork(&asoc->outqueue);
1085                                 local_cork = 0;
1086                         }
1087                         /* Delete the current association.  */
1088                         sctp_cmd_delete_tcb(commands, asoc);
1089                         asoc = NULL;
1090                         break;
1091
1092                 case SCTP_CMD_NEW_STATE:
1093                         /* Enter a new state.  */
1094                         sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1095                         break;
1096
1097                 case SCTP_CMD_REPORT_TSN:
1098                         /* Record the arrival of a TSN.  */
1099                         sctp_tsnmap_mark(&asoc->peer.tsn_map, cmd->obj.u32);
1100                         break;
1101
1102                 case SCTP_CMD_REPORT_FWDTSN:
1103                         /* Move the Cumulattive TSN Ack ahead. */
1104                         sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32);
1105
1106                         /* Abort any in progress partial delivery. */
1107                         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
1108                         break;
1109
1110                 case SCTP_CMD_PROCESS_FWDTSN:
1111                         sctp_cmd_process_fwdtsn(&asoc->ulpq, cmd->obj.ptr);
1112                         break;
1113
1114                 case SCTP_CMD_GEN_SACK:
1115                         /* Generate a Selective ACK.
1116                          * The argument tells us whether to just count
1117                          * the packet and MAYBE generate a SACK, or
1118                          * force a SACK out.
1119                          */
1120                         force = cmd->obj.i32;
1121                         error = sctp_gen_sack(asoc, force, commands);
1122                         break;
1123
1124                 case SCTP_CMD_PROCESS_SACK:
1125                         /* Process an inbound SACK.  */
1126                         error = sctp_cmd_process_sack(commands, asoc,
1127                                                       cmd->obj.ptr);
1128                         break;
1129
1130                 case SCTP_CMD_GEN_INIT_ACK:
1131                         /* Generate an INIT ACK chunk.  */
1132                         new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1133                                                      0);
1134                         if (!new_obj)
1135                                 goto nomem;
1136
1137                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1138                                         SCTP_CHUNK(new_obj));
1139                         break;
1140
1141                 case SCTP_CMD_PEER_INIT:
1142                         /* Process a unified INIT from the peer.
1143                          * Note: Only used during INIT-ACK processing.  If
1144                          * there is an error just return to the outter
1145                          * layer which will bail.
1146                          */
1147                         error = sctp_cmd_process_init(commands, asoc, chunk,
1148                                                       cmd->obj.ptr, gfp);
1149                         break;
1150
1151                 case SCTP_CMD_GEN_COOKIE_ECHO:
1152                         /* Generate a COOKIE ECHO chunk.  */
1153                         new_obj = sctp_make_cookie_echo(asoc, chunk);
1154                         if (!new_obj) {
1155                                 if (cmd->obj.ptr)
1156                                         sctp_chunk_free(cmd->obj.ptr);
1157                                 goto nomem;
1158                         }
1159                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1160                                         SCTP_CHUNK(new_obj));
1161
1162                         /* If there is an ERROR chunk to be sent along with
1163                          * the COOKIE_ECHO, send it, too.
1164                          */
1165                         if (cmd->obj.ptr)
1166                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1167                                                 SCTP_CHUNK(cmd->obj.ptr));
1168
1169                         /* FIXME - Eventually come up with a cleaner way to
1170                          * enabling COOKIE-ECHO + DATA bundling during
1171                          * multihoming stale cookie scenarios, the following
1172                          * command plays with asoc->peer.retran_path to
1173                          * avoid the problem of sending the COOKIE-ECHO and
1174                          * DATA in different paths, which could result
1175                          * in the association being ABORTed if the DATA chunk
1176                          * is processed first by the server.  Checking the
1177                          * init error counter simply causes this command
1178                          * to be executed only during failed attempts of
1179                          * association establishment.
1180                          */
1181                         if ((asoc->peer.retran_path !=
1182                              asoc->peer.primary_path) &&
1183                             (asoc->init_err_counter > 0)) {
1184                                 sctp_add_cmd_sf(commands,
1185                                                 SCTP_CMD_FORCE_PRIM_RETRAN,
1186                                                 SCTP_NULL());
1187                         }
1188
1189                         break;
1190
1191                 case SCTP_CMD_GEN_SHUTDOWN:
1192                         /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1193                          * Reset error counts.
1194                          */
1195                         asoc->overall_error_count = 0;
1196
1197                         /* Generate a SHUTDOWN chunk.  */
1198                         new_obj = sctp_make_shutdown(asoc, chunk);
1199                         if (!new_obj)
1200                                 goto nomem;
1201                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1202                                         SCTP_CHUNK(new_obj));
1203                         break;
1204
1205                 case SCTP_CMD_CHUNK_ULP:
1206                         /* Send a chunk to the sockets layer.  */
1207                         SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1208                                           "chunk_up:", cmd->obj.ptr,
1209                                           "ulpq:", &asoc->ulpq);
1210                         sctp_ulpq_tail_data(&asoc->ulpq, cmd->obj.ptr,
1211                                             GFP_ATOMIC);
1212                         break;
1213
1214                 case SCTP_CMD_EVENT_ULP:
1215                         /* Send a notification to the sockets layer.  */
1216                         SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1217                                           "event_up:",cmd->obj.ptr,
1218                                           "ulpq:",&asoc->ulpq);
1219                         sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ptr);
1220                         break;
1221
1222                 case SCTP_CMD_REPLY:
1223                         /* If an caller has not already corked, do cork. */
1224                         if (!asoc->outqueue.cork) {
1225                                 sctp_outq_cork(&asoc->outqueue);
1226                                 local_cork = 1;
1227                         }
1228                         /* Send a chunk to our peer.  */
1229                         error = sctp_outq_tail(&asoc->outqueue, cmd->obj.ptr);
1230                         break;
1231
1232                 case SCTP_CMD_SEND_PKT:
1233                         /* Send a full packet to our peer.  */
1234                         packet = cmd->obj.ptr;
1235                         sctp_packet_transmit(packet);
1236                         sctp_ootb_pkt_free(packet);
1237                         break;
1238
1239                 case SCTP_CMD_RETRAN:
1240                         /* Mark a transport for retransmission.  */
1241                         sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1242                                         SCTP_RTXR_T3_RTX);
1243                         break;
1244
1245                 case SCTP_CMD_TRANSMIT:
1246                         /* Kick start transmission. */
1247                         error = sctp_outq_uncork(&asoc->outqueue);
1248                         local_cork = 0;
1249                         break;
1250
1251                 case SCTP_CMD_ECN_CE:
1252                         /* Do delayed CE processing.   */
1253                         sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1254                         break;
1255
1256                 case SCTP_CMD_ECN_ECNE:
1257                         /* Do delayed ECNE processing. */
1258                         new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1259                                                         chunk);
1260                         if (new_obj)
1261                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1262                                                 SCTP_CHUNK(new_obj));
1263                         break;
1264
1265                 case SCTP_CMD_ECN_CWR:
1266                         /* Do delayed CWR processing.  */
1267                         sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1268                         break;
1269
1270                 case SCTP_CMD_SETUP_T2:
1271                         sctp_cmd_setup_t2(commands, asoc, cmd->obj.ptr);
1272                         break;
1273
1274                 case SCTP_CMD_TIMER_START:
1275                         timer = &asoc->timers[cmd->obj.to];
1276                         timeout = asoc->timeouts[cmd->obj.to];
1277                         BUG_ON(!timeout);
1278
1279                         timer->expires = jiffies + timeout;
1280                         sctp_association_hold(asoc);
1281                         add_timer(timer);
1282                         break;
1283
1284                 case SCTP_CMD_TIMER_RESTART:
1285                         timer = &asoc->timers[cmd->obj.to];
1286                         timeout = asoc->timeouts[cmd->obj.to];
1287                         if (!mod_timer(timer, jiffies + timeout))
1288                                 sctp_association_hold(asoc);
1289                         break;
1290
1291                 case SCTP_CMD_TIMER_STOP:
1292                         timer = &asoc->timers[cmd->obj.to];
1293                         if (timer_pending(timer) && del_timer(timer))
1294                                 sctp_association_put(asoc);
1295                         break;
1296
1297                 case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1298                         chunk = cmd->obj.ptr;
1299                         t = sctp_assoc_choose_init_transport(asoc);
1300                         asoc->init_last_sent_to = t;
1301                         chunk->transport = t;
1302                         t->init_sent_count++;
1303                         break;
1304
1305                 case SCTP_CMD_INIT_RESTART:
1306                         /* Do the needed accounting and updates
1307                          * associated with restarting an initialization
1308                          * timer. Only multiply the timeout by two if
1309                          * all transports have been tried at the current
1310                          * timeout.
1311                          */
1312                         t = asoc->init_last_sent_to;
1313                         asoc->init_err_counter++;
1314
1315                         if (t->init_sent_count > (asoc->init_cycle + 1)) {
1316                                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] *= 2;
1317                                 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] >
1318                                     asoc->max_init_timeo) {
1319                                         asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
1320                                                 asoc->max_init_timeo;
1321                                 }
1322                                 asoc->init_cycle++;
1323                                 SCTP_DEBUG_PRINTK(
1324                                         "T1 INIT Timeout adjustment"
1325                                         " init_err_counter: %d"
1326                                         " cycle: %d"
1327                                         " timeout: %ld\n",
1328                                         asoc->init_err_counter,
1329                                         asoc->init_cycle,
1330                                         asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT]);
1331                         }
1332
1333                         sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1334                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1335                         break;
1336
1337                 case SCTP_CMD_COOKIEECHO_RESTART:
1338                         /* Do the needed accounting and updates
1339                          * associated with restarting an initialization
1340                          * timer. Only multiply the timeout by two if
1341                          * all transports have been tried at the current
1342                          * timeout.
1343                          */
1344                         asoc->init_err_counter++;
1345
1346                         asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] *= 2;
1347                         if (asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] >
1348                             asoc->max_init_timeo) {
1349                                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
1350                                         asoc->max_init_timeo;
1351                         }
1352                         SCTP_DEBUG_PRINTK(
1353                                 "T1 COOKIE Timeout adjustment"
1354                                 " init_err_counter: %d"
1355                                 " timeout: %ld\n",
1356                                 asoc->init_err_counter,
1357                                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE]);
1358
1359                         /* If we've sent any data bundled with
1360                          * COOKIE-ECHO we need to resend.
1361                          */
1362                         list_for_each(pos, &asoc->peer.transport_addr_list) {
1363                                 t = list_entry(pos, struct sctp_transport,
1364                                                transports);
1365                                 sctp_retransmit_mark(&asoc->outqueue, t, 0);
1366                         }
1367
1368                         sctp_add_cmd_sf(commands,
1369                                         SCTP_CMD_TIMER_RESTART,
1370                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1371                         break;
1372
1373                 case SCTP_CMD_INIT_FAILED:
1374                         sctp_cmd_init_failed(commands, asoc, cmd->obj.err);
1375                         break;
1376
1377                 case SCTP_CMD_ASSOC_FAILED:
1378                         sctp_cmd_assoc_failed(commands, asoc, event_type,
1379                                               subtype, chunk, cmd->obj.err);
1380                         break;
1381
1382                 case SCTP_CMD_INIT_COUNTER_INC:
1383                         asoc->init_err_counter++;
1384                         break;
1385
1386                 case SCTP_CMD_INIT_COUNTER_RESET:
1387                         asoc->init_err_counter = 0;
1388                         asoc->init_cycle = 0;
1389                         break;
1390
1391                 case SCTP_CMD_REPORT_DUP:
1392                         sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1393                                              cmd->obj.u32);
1394                         break;
1395
1396                 case SCTP_CMD_REPORT_BAD_TAG:
1397                         SCTP_DEBUG_PRINTK("vtag mismatch!\n");
1398                         break;
1399
1400                 case SCTP_CMD_STRIKE:
1401                         /* Mark one strike against a transport.  */
1402                         sctp_do_8_2_transport_strike(asoc, cmd->obj.transport);
1403                         break;
1404
1405                 case SCTP_CMD_TRANSPORT_RESET:
1406                         t = cmd->obj.transport;
1407                         sctp_cmd_transport_reset(commands, asoc, t);
1408                         break;
1409
1410                 case SCTP_CMD_TRANSPORT_ON:
1411                         t = cmd->obj.transport;
1412                         sctp_cmd_transport_on(commands, asoc, t, chunk);
1413                         break;
1414
1415                 case SCTP_CMD_HB_TIMERS_START:
1416                         sctp_cmd_hb_timers_start(commands, asoc);
1417                         break;
1418
1419                 case SCTP_CMD_HB_TIMER_UPDATE:
1420                         t = cmd->obj.transport;
1421                         sctp_cmd_hb_timer_update(commands, asoc, t);
1422                         break;
1423
1424                 case SCTP_CMD_HB_TIMERS_STOP:
1425                         sctp_cmd_hb_timers_stop(commands, asoc);
1426                         break;
1427
1428                 case SCTP_CMD_REPORT_ERROR:
1429                         error = cmd->obj.error;
1430                         break;
1431
1432                 case SCTP_CMD_PROCESS_CTSN:
1433                         /* Dummy up a SACK for processing. */
1434                         sackh.cum_tsn_ack = cmd->obj.be32;
1435                         sackh.a_rwnd = 0;
1436                         sackh.num_gap_ack_blocks = 0;
1437                         sackh.num_dup_tsns = 0;
1438                         sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1439                                         SCTP_SACKH(&sackh));
1440                         break;
1441
1442                 case SCTP_CMD_DISCARD_PACKET:
1443                         /* We need to discard the whole packet.  */
1444                         chunk->pdiscard = 1;
1445                         break;
1446
1447                 case SCTP_CMD_RTO_PENDING:
1448                         t = cmd->obj.transport;
1449                         t->rto_pending = 1;
1450                         break;
1451
1452                 case SCTP_CMD_PART_DELIVER:
1453                         sctp_ulpq_partial_delivery(&asoc->ulpq, cmd->obj.ptr,
1454                                                    GFP_ATOMIC);
1455                         break;
1456
1457                 case SCTP_CMD_RENEGE:
1458                         sctp_ulpq_renege(&asoc->ulpq, cmd->obj.ptr,
1459                                          GFP_ATOMIC);
1460                         break;
1461
1462                 case SCTP_CMD_SETUP_T4:
1463                         sctp_cmd_setup_t4(commands, asoc, cmd->obj.ptr);
1464                         break;
1465
1466                 case SCTP_CMD_PROCESS_OPERR:
1467                         sctp_cmd_process_operr(commands, asoc, chunk);
1468                         break;
1469                 case SCTP_CMD_CLEAR_INIT_TAG:
1470                         asoc->peer.i.init_tag = 0;
1471                         break;
1472                 case SCTP_CMD_DEL_NON_PRIMARY:
1473                         sctp_cmd_del_non_primary(asoc);
1474                         break;
1475                 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1476                         sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1477                         break;
1478                 case SCTP_CMD_FORCE_PRIM_RETRAN:
1479                         t = asoc->peer.retran_path;
1480                         asoc->peer.retran_path = asoc->peer.primary_path;
1481                         error = sctp_outq_uncork(&asoc->outqueue);
1482                         local_cork = 0;
1483                         asoc->peer.retran_path = t;
1484                         break;
1485                 case SCTP_CMD_SET_SK_ERR:
1486                         sctp_cmd_set_sk_err(asoc, cmd->obj.error);
1487                         break;
1488                 default:
1489                         printk(KERN_WARNING "Impossible command: %u, %p\n",
1490                                cmd->verb, cmd->obj.ptr);
1491                         break;
1492                 }
1493
1494                 if (error)
1495                         break;
1496         }
1497
1498 out:
1499         if (local_cork)
1500                 sctp_outq_uncork(&asoc->outqueue);
1501         return error;
1502 nomem:
1503         error = -ENOMEM;
1504         goto out;
1505 }
1506