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