net/sctp/sm_sideeffect.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* SCTP kernel implementation
   3  * (C) Copyright IBM Corp. 2001, 2004
   4  * Copyright (c) 1999 Cisco, Inc.
   5  * Copyright (c) 1999-2001 Motorola, Inc.
   6  *
   7  * This file is part of the SCTP kernel implementation
   8  *
   9  * These functions work with the state functions in sctp_sm_statefuns.c
  10  * to implement that state operations.  These functions implement the
  11  * steps which require modifying existing data structures.
  12  *
  13  * Please send any bug reports or fixes you make to the
  14  * email address(es):
  15  *    lksctp developers <linux-sctp@vger.kernel.org>
  16  *
  17  * Written or modified by:
  18  *    La Monte H.P. Yarroll <piggy@acm.org>
  19  *    Karl Knutson          <karl@athena.chicago.il.us>
  20  *    Jon Grimm             <jgrimm@austin.ibm.com>
  21  *    Hui Huang             <hui.huang@nokia.com>
  22  *    Dajiang Zhang         <dajiang.zhang@nokia.com>
  23  *    Daisy Chang           <daisyc@us.ibm.com>
  24  *    Sridhar Samudrala     <sri@us.ibm.com>
  25  *    Ardelle Fan           <ardelle.fan@intel.com>
  26  */
  27
  28 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  29
  30 #include <linux/skbuff.h>
  31 #include <linux/types.h>
  32 #include <linux/socket.h>
  33 #include <linux/ip.h>
  34 #include <linux/gfp.h>
  35 #include <net/sock.h>
  36 #include <net/sctp/sctp.h>
  37 #include <net/sctp/sm.h>
  38 #include <net/sctp/stream_sched.h>
  39
  40 static int sctp_cmd_interpreter(enum sctp_event_type event_type,
  41                                 union sctp_subtype subtype,
  42                                 enum sctp_state state,
  43                                 struct sctp_endpoint *ep,
  44                                 struct sctp_association *asoc,
  45                                 void *event_arg,
  46                                 enum sctp_disposition status,
  47                                 struct sctp_cmd_seq *commands,
  48                                 gfp_t gfp);
  49 static int sctp_side_effects(enum sctp_event_type event_type,
  50                              union sctp_subtype subtype,
  51                              enum sctp_state state,
  52                              struct sctp_endpoint *ep,
  53                              struct sctp_association **asoc,
  54                              void *event_arg,
  55                              enum sctp_disposition status,
  56                              struct sctp_cmd_seq *commands,
  57                              gfp_t gfp);
  58
  59 /********************************************************************
  60  * Helper functions
  61  ********************************************************************/
  62
  63 /* A helper function for delayed processing of INET ECN CE bit. */
  64 static void sctp_do_ecn_ce_work(struct sctp_association *asoc,
  65                                 __u32 lowest_tsn)
  66 {
  67         /* Save the TSN away for comparison when we receive CWR */
  68
  69         asoc->last_ecne_tsn = lowest_tsn;
  70         asoc->need_ecne = 1;
  71 }
  72
  73 /* Helper function for delayed processing of SCTP ECNE chunk.  */
  74 /* RFC 2960 Appendix A
  75  *
  76  * RFC 2481 details a specific bit for a sender to send in
  77  * the header of its next outbound TCP segment to indicate to
  78  * its peer that it has reduced its congestion window.  This
  79  * is termed the CWR bit.  For SCTP the same indication is made
  80  * by including the CWR chunk.  This chunk contains one data
  81  * element, i.e. the TSN number that was sent in the ECNE chunk.
  82  * This element represents the lowest TSN number in the datagram
  83  * that was originally marked with the CE bit.
  84  */
  85 static struct sctp_chunk *sctp_do_ecn_ecne_work(struct sctp_association *asoc,
  86                                                 __u32 lowest_tsn,
  87                                                 struct sctp_chunk *chunk)
  88 {
  89         struct sctp_chunk *repl;
  90
  91         /* Our previously transmitted packet ran into some congestion
  92          * so we should take action by reducing cwnd and ssthresh
  93          * and then ACK our peer that we we've done so by
  94          * sending a CWR.
  95          */
  96
  97         /* First, try to determine if we want to actually lower
  98          * our cwnd variables.  Only lower them if the ECNE looks more
  99          * recent than the last response.
 100          */
 101         if (TSN_lt(asoc->last_cwr_tsn, lowest_tsn)) {
 102                 struct sctp_transport *transport;
 103
 104                 /* Find which transport's congestion variables
 105                  * need to be adjusted.
 106                  */
 107                 transport = sctp_assoc_lookup_tsn(asoc, lowest_tsn);
 108
 109                 /* Update the congestion variables. */
 110                 if (transport)
 111                         sctp_transport_lower_cwnd(transport,
 112                                                   SCTP_LOWER_CWND_ECNE);
 113                 asoc->last_cwr_tsn = lowest_tsn;
 114         }
 115
 116         /* Always try to quiet the other end.  In case of lost CWR,
 117          * resend last_cwr_tsn.
 118          */
 119         repl = sctp_make_cwr(asoc, asoc->last_cwr_tsn, chunk);
 120
 121         /* If we run out of memory, it will look like a lost CWR.  We'll
 122          * get back in sync eventually.
 123          */
 124         return repl;
 125 }
 126
 127 /* Helper function to do delayed processing of ECN CWR chunk.  */
 128 static void sctp_do_ecn_cwr_work(struct sctp_association *asoc,
 129                                  __u32 lowest_tsn)
 130 {
 131         /* Turn off ECNE getting auto-prepended to every outgoing
 132          * packet
 133          */
 134         asoc->need_ecne = 0;
 135 }
 136
 137 /* Generate SACK if necessary.  We call this at the end of a packet.  */
 138 static int sctp_gen_sack(struct sctp_association *asoc, int force,
 139                          struct sctp_cmd_seq *commands)
 140 {
 141         struct sctp_transport *trans = asoc->peer.last_data_from;
 142         __u32 ctsn, max_tsn_seen;
 143         struct sctp_chunk *sack;
 144         int error = 0;
 145
 146         if (force ||
 147             (!trans && (asoc->param_flags & SPP_SACKDELAY_DISABLE)) ||
 148             (trans && (trans->param_flags & SPP_SACKDELAY_DISABLE)))
 149                 asoc->peer.sack_needed = 1;
 150
 151         ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
 152         max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
 153
 154         /* From 12.2 Parameters necessary per association (i.e. the TCB):
 155          *
 156          * Ack State : This flag indicates if the next received packet
 157          *           : is to be responded to with a SACK. ...
 158          *           : When DATA chunks are out of order, SACK's
 159          *           : are not delayed (see Section 6).
 160          *
 161          * [This is actually not mentioned in Section 6, but we
 162          * implement it here anyway. --piggy]
 163          */
 164         if (max_tsn_seen != ctsn)
 165                 asoc->peer.sack_needed = 1;
 166
 167         /* From 6.2  Acknowledgement on Reception of DATA Chunks:
 168          *
 169          * Section 4.2 of [RFC2581] SHOULD be followed. Specifically,
 170          * an acknowledgement SHOULD be generated for at least every
 171          * second packet (not every second DATA chunk) received, and
 172          * SHOULD be generated within 200 ms of the arrival of any
 173          * unacknowledged DATA chunk. ...
 174          */
 175         if (!asoc->peer.sack_needed) {
 176                 asoc->peer.sack_cnt++;
 177
 178                 /* Set the SACK delay timeout based on the
 179                  * SACK delay for the last transport
 180                  * data was received from, or the default
 181                  * for the association.
 182                  */
 183                 if (trans) {
 184                         /* We will need a SACK for the next packet.  */
 185                         if (asoc->peer.sack_cnt >= trans->sackfreq - 1)
 186                                 asoc->peer.sack_needed = 1;
 187
 188                         asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
 189                                 trans->sackdelay;
 190                 } else {
 191                         /* We will need a SACK for the next packet.  */
 192                         if (asoc->peer.sack_cnt >= asoc->sackfreq - 1)
 193                                 asoc->peer.sack_needed = 1;
 194
 195                         asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
 196                                 asoc->sackdelay;
 197                 }
 198
 199                 /* Restart the SACK timer. */
 200                 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
 201                                 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
 202         } else {
 203                 __u32 old_a_rwnd = asoc->a_rwnd;
 204
 205                 asoc->a_rwnd = asoc->rwnd;
 206                 sack = sctp_make_sack(asoc);
 207                 if (!sack) {
 208                         asoc->a_rwnd = old_a_rwnd;
 209                         goto nomem;
 210                 }
 211
 212                 asoc->peer.sack_needed = 0;
 213                 asoc->peer.sack_cnt = 0;
 214
 215                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(sack));
 216
 217                 /* Stop the SACK timer.  */
 218                 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
 219                                 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
 220         }
 221
 222         return error;
 223 nomem:
 224         error = -ENOMEM;
 225         return error;
 226 }
 227
 228 /* When the T3-RTX timer expires, it calls this function to create the
 229  * relevant state machine event.
 230  */
 231 void sctp_generate_t3_rtx_event(struct timer_list *t)
 232 {
 233         struct sctp_transport *transport =
 234                 from_timer(transport, t, T3_rtx_timer);
 235         struct sctp_association *asoc = transport->asoc;
 236         struct sock *sk = asoc->base.sk;
 237         struct net *net = sock_net(sk);
 238         int error;
 239
 240         /* Check whether a task is in the sock.  */
 241
 242         bh_lock_sock(sk);
 243         if (sock_owned_by_user(sk)) {
 244                 pr_debug("%s: sock is busy\n", __func__);
 245
 246                 /* Try again later.  */
 247                 if (!mod_timer(&transport->T3_rtx_timer, jiffies + (HZ/20)))
 248                         sctp_transport_hold(transport);
 249                 goto out_unlock;
 250         }
 251
 252         /* Run through the state machine.  */
 253         error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
 254                            SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX),
 255                            asoc->state,
 256                            asoc->ep, asoc,
 257                            transport, GFP_ATOMIC);
 258
 259         if (error)
 260                 sk->sk_err = -error;
 261
 262 out_unlock:
 263         bh_unlock_sock(sk);
 264         sctp_transport_put(transport);
 265 }
 266
 267 /* This is a sa interface for producing timeout events.  It works
 268  * for timeouts which use the association as their parameter.
 269  */
 270 static void sctp_generate_timeout_event(struct sctp_association *asoc,
 271                                         enum sctp_event_timeout timeout_type)
 272 {
 273         struct sock *sk = asoc->base.sk;
 274         struct net *net = sock_net(sk);
 275         int error = 0;
 276
 277         bh_lock_sock(sk);
 278         if (sock_owned_by_user(sk)) {
 279                 pr_debug("%s: sock is busy: timer %d\n", __func__,
 280                          timeout_type);
 281
 282                 /* Try again later.  */
 283                 if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20)))
 284                         sctp_association_hold(asoc);
 285                 goto out_unlock;
 286         }
 287
 288         /* Is this association really dead and just waiting around for
 289          * the timer to let go of the reference?
 290          */
 291         if (asoc->base.dead)
 292                 goto out_unlock;
 293
 294         /* Run through the state machine.  */
 295         error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
 296                            SCTP_ST_TIMEOUT(timeout_type),
 297                            asoc->state, asoc->ep, asoc,
 298                            (void *)timeout_type, GFP_ATOMIC);
 299
 300         if (error)
 301                 sk->sk_err = -error;
 302
 303 out_unlock:
 304         bh_unlock_sock(sk);
 305         sctp_association_put(asoc);
 306 }
 307
 308 static void sctp_generate_t1_cookie_event(struct timer_list *t)
 309 {
 310         struct sctp_association *asoc =
 311                 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_T1_COOKIE]);
 312
 313         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
 314 }
 315
 316 static void sctp_generate_t1_init_event(struct timer_list *t)
 317 {
 318         struct sctp_association *asoc =
 319                 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_T1_INIT]);
 320
 321         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
 322 }
 323
 324 static void sctp_generate_t2_shutdown_event(struct timer_list *t)
 325 {
 326         struct sctp_association *asoc =
 327                 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN]);
 328
 329         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
 330 }
 331
 332 static void sctp_generate_t4_rto_event(struct timer_list *t)
 333 {
 334         struct sctp_association *asoc =
 335                 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_T4_RTO]);
 336
 337         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
 338 }
 339
 340 static void sctp_generate_t5_shutdown_guard_event(struct timer_list *t)
 341 {
 342         struct sctp_association *asoc =
 343                 from_timer(asoc, t,
 344                            timers[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD]);
 345
 346         sctp_generate_timeout_event(asoc,
 347                                     SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);
 348
 349 } /* sctp_generate_t5_shutdown_guard_event() */
 350
 351 static void sctp_generate_autoclose_event(struct timer_list *t)
 352 {
 353         struct sctp_association *asoc =
 354                 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_AUTOCLOSE]);
 355
 356         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE);
 357 }
 358
 359 /* Generate a heart beat event.  If the sock is busy, reschedule.   Make
 360  * sure that the transport is still valid.
 361  */
 362 void sctp_generate_heartbeat_event(struct timer_list *t)
 363 {
 364         struct sctp_transport *transport = from_timer(transport, t, hb_timer);
 365         struct sctp_association *asoc = transport->asoc;
 366         struct sock *sk = asoc->base.sk;
 367         struct net *net = sock_net(sk);
 368         u32 elapsed, timeout;
 369         int error = 0;
 370
 371         bh_lock_sock(sk);
 372         if (sock_owned_by_user(sk)) {
 373                 pr_debug("%s: sock is busy\n", __func__);
 374
 375                 /* Try again later.  */
 376                 if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20)))
 377                         sctp_transport_hold(transport);
 378                 goto out_unlock;
 379         }
 380
 381         /* Check if we should still send the heartbeat or reschedule */
 382         elapsed = jiffies - transport->last_time_sent;
 383         timeout = sctp_transport_timeout(transport);
 384         if (elapsed < timeout) {
 385                 elapsed = timeout - elapsed;
 386                 if (!mod_timer(&transport->hb_timer, jiffies + elapsed))
 387                         sctp_transport_hold(transport);
 388                 goto out_unlock;
 389         }
 390
 391         error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
 392                            SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
 393                            asoc->state, asoc->ep, asoc,
 394                            transport, GFP_ATOMIC);
 395
 396         if (error)
 397                 sk->sk_err = -error;
 398
 399 out_unlock:
 400         bh_unlock_sock(sk);
 401         sctp_transport_put(transport);
 402 }
 403
 404 /* Handle the timeout of the ICMP protocol unreachable timer.  Trigger
 405  * the correct state machine transition that will close the association.
 406  */
 407 void sctp_generate_proto_unreach_event(struct timer_list *t)
 408 {
 409         struct sctp_transport *transport =
 410                 from_timer(transport, t, proto_unreach_timer);
 411         struct sctp_association *asoc = transport->asoc;
 412         struct sock *sk = asoc->base.sk;
 413         struct net *net = sock_net(sk);
 414
 415         bh_lock_sock(sk);
 416         if (sock_owned_by_user(sk)) {
 417                 pr_debug("%s: sock is busy\n", __func__);
 418
 419                 /* Try again later.  */
 420                 if (!mod_timer(&transport->proto_unreach_timer,
 421                                 jiffies + (HZ/20)))
 422                         sctp_transport_hold(transport);
 423                 goto out_unlock;
 424         }
 425
 426         /* Is this structure just waiting around for us to actually
 427          * get destroyed?
 428          */
 429         if (asoc->base.dead)
 430                 goto out_unlock;
 431
 432         sctp_do_sm(net, SCTP_EVENT_T_OTHER,
 433                    SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH),
 434                    asoc->state, asoc->ep, asoc, transport, GFP_ATOMIC);
 435
 436 out_unlock:
 437         bh_unlock_sock(sk);
 438         sctp_transport_put(transport);
 439 }
 440
 441  /* Handle the timeout of the RE-CONFIG timer. */
 442 void sctp_generate_reconf_event(struct timer_list *t)
 443 {
 444         struct sctp_transport *transport =
 445                 from_timer(transport, t, reconf_timer);
 446         struct sctp_association *asoc = transport->asoc;
 447         struct sock *sk = asoc->base.sk;
 448         struct net *net = sock_net(sk);
 449         int error = 0;
 450
 451         bh_lock_sock(sk);
 452         if (sock_owned_by_user(sk)) {
 453                 pr_debug("%s: sock is busy\n", __func__);
 454
 455                 /* Try again later.  */
 456                 if (!mod_timer(&transport->reconf_timer, jiffies + (HZ / 20)))
 457                         sctp_transport_hold(transport);
 458                 goto out_unlock;
 459         }
 460
 461         error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
 462                            SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_RECONF),
 463                            asoc->state, asoc->ep, asoc,
 464                            transport, GFP_ATOMIC);
 465
 466         if (error)
 467                 sk->sk_err = -error;
 468
 469 out_unlock:
 470         bh_unlock_sock(sk);
 471         sctp_transport_put(transport);
 472 }
 473
 474 /* Handle the timeout of the probe timer. */
 475 void sctp_generate_probe_event(struct timer_list *t)
 476 {
 477         struct sctp_transport *transport = from_timer(transport, t, probe_timer);
 478         struct sctp_association *asoc = transport->asoc;
 479         struct sock *sk = asoc->base.sk;
 480         struct net *net = sock_net(sk);
 481         int error = 0;
 482
 483         bh_lock_sock(sk);
 484         if (sock_owned_by_user(sk)) {
 485                 pr_debug("%s: sock is busy\n", __func__);
 486
 487                 /* Try again later.  */
 488                 if (!mod_timer(&transport->probe_timer, jiffies + (HZ / 20)))
 489                         sctp_transport_hold(transport);
 490                 goto out_unlock;
 491         }
 492
 493         error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
 494                            SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_PROBE),
 495                            asoc->state, asoc->ep, asoc,
 496                            transport, GFP_ATOMIC);
 497
 498         if (error)
 499                 sk->sk_err = -error;
 500
 501 out_unlock:
 502         bh_unlock_sock(sk);
 503         sctp_transport_put(transport);
 504 }
 505
 506 /* Inject a SACK Timeout event into the state machine.  */
 507 static void sctp_generate_sack_event(struct timer_list *t)
 508 {
 509         struct sctp_association *asoc =
 510                 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_SACK]);
 511
 512         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
 513 }
 514
 515 sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
 516         [SCTP_EVENT_TIMEOUT_NONE] =             NULL,
 517         [SCTP_EVENT_TIMEOUT_T1_COOKIE] =        sctp_generate_t1_cookie_event,
 518         [SCTP_EVENT_TIMEOUT_T1_INIT] =          sctp_generate_t1_init_event,
 519         [SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] =      sctp_generate_t2_shutdown_event,
 520         [SCTP_EVENT_TIMEOUT_T3_RTX] =           NULL,
 521         [SCTP_EVENT_TIMEOUT_T4_RTO] =           sctp_generate_t4_rto_event,
 522         [SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD] =
 523                                         sctp_generate_t5_shutdown_guard_event,
 524         [SCTP_EVENT_TIMEOUT_HEARTBEAT] =        NULL,
 525         [SCTP_EVENT_TIMEOUT_RECONF] =           NULL,
 526         [SCTP_EVENT_TIMEOUT_SACK] =             sctp_generate_sack_event,
 527         [SCTP_EVENT_TIMEOUT_AUTOCLOSE] =        sctp_generate_autoclose_event,
 528 };
 529
 530
 531 /* RFC 2960 8.2 Path Failure Detection
 532  *
 533  * When its peer endpoint is multi-homed, an endpoint should keep a
 534  * error counter for each of the destination transport addresses of the
 535  * peer endpoint.
 536  *
 537  * Each time the T3-rtx timer expires on any address, or when a
 538  * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
 539  * the error counter of that destination address will be incremented.
 540  * When the value in the error counter exceeds the protocol parameter
 541  * 'Path.Max.Retrans' of that destination address, the endpoint should
 542  * mark the destination transport address as inactive, and a
 543  * notification SHOULD be sent to the upper layer.
 544  *
 545  */
 546 static void sctp_do_8_2_transport_strike(struct sctp_cmd_seq *commands,
 547                                          struct sctp_association *asoc,
 548                                          struct sctp_transport *transport,
 549                                          int is_hb)
 550 {
 551         /* The check for association's overall error counter exceeding the
 552          * threshold is done in the state function.
 553          */
 554         /* We are here due to a timer expiration.  If the timer was
 555          * not a HEARTBEAT, then normal error tracking is done.
 556          * If the timer was a heartbeat, we only increment error counts
 557          * when we already have an outstanding HEARTBEAT that has not
 558          * been acknowledged.
 559          * Additionally, some tranport states inhibit error increments.
 560          */
 561         if (!is_hb) {
 562                 asoc->overall_error_count++;
 563                 if (transport->state != SCTP_INACTIVE)
 564                         transport->error_count++;
 565          } else if (transport->hb_sent) {
 566                 if (transport->state != SCTP_UNCONFIRMED)
 567                         asoc->overall_error_count++;
 568                 if (transport->state != SCTP_INACTIVE)
 569                         transport->error_count++;
 570         }
 571
 572         /* If the transport error count is greater than the pf_retrans
 573          * threshold, and less than pathmaxrtx, and if the current state
 574          * is SCTP_ACTIVE, then mark this transport as Partially Failed,
 575          * see SCTP Quick Failover Draft, section 5.1
 576          */
 577         if (asoc->base.net->sctp.pf_enable &&
 578             transport->state == SCTP_ACTIVE &&
 579             transport->error_count < transport->pathmaxrxt &&
 580             transport->error_count > transport->pf_retrans) {
 581
 582                 sctp_assoc_control_transport(asoc, transport,
 583                                              SCTP_TRANSPORT_PF,
 584                                              0);
 585
 586                 /* Update the hb timer to resend a heartbeat every rto */
 587                 sctp_transport_reset_hb_timer(transport);
 588         }
 589
 590         if (transport->state != SCTP_INACTIVE &&
 591             (transport->error_count > transport->pathmaxrxt)) {
 592                 pr_debug("%s: association:%p transport addr:%pISpc failed\n",
 593                          __func__, asoc, &transport->ipaddr.sa);
 594
 595                 sctp_assoc_control_transport(asoc, transport,
 596                                              SCTP_TRANSPORT_DOWN,
 597                                              SCTP_FAILED_THRESHOLD);
 598         }
 599
 600         if (transport->error_count > transport->ps_retrans &&
 601             asoc->peer.primary_path == transport &&
 602             asoc->peer.active_path != transport)
 603                 sctp_assoc_set_primary(asoc, asoc->peer.active_path);
 604
 605         /* E2) For the destination address for which the timer
 606          * expires, set RTO <- RTO * 2 ("back off the timer").  The
 607          * maximum value discussed in rule C7 above (RTO.max) may be
 608          * used to provide an upper bound to this doubling operation.
 609          *
 610          * Special Case:  the first HB doesn't trigger exponential backoff.
 611          * The first unacknowledged HB triggers it.  We do this with a flag
 612          * that indicates that we have an outstanding HB.
 613          */
 614         if (!is_hb || transport->hb_sent) {
 615                 transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
 616                 sctp_max_rto(asoc, transport);
 617         }
 618 }
 619
 620 /* Worker routine to handle INIT command failure.  */
 621 static void sctp_cmd_init_failed(struct sctp_cmd_seq *commands,
 622                                  struct sctp_association *asoc,
 623                                  unsigned int error)
 624 {
 625         struct sctp_ulpevent *event;
 626
 627         event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_CANT_STR_ASSOC,
 628                                                 (__u16)error, 0, 0, NULL,
 629                                                 GFP_ATOMIC);
 630
 631         if (event)
 632                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 633                                 SCTP_ULPEVENT(event));
 634
 635         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 636                         SCTP_STATE(SCTP_STATE_CLOSED));
 637
 638         /* SEND_FAILED sent later when cleaning up the association. */
 639         asoc->outqueue.error = error;
 640         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 641 }
 642
 643 /* Worker routine to handle SCTP_CMD_ASSOC_FAILED.  */
 644 static void sctp_cmd_assoc_failed(struct sctp_cmd_seq *commands,
 645                                   struct sctp_association *asoc,
 646                                   enum sctp_event_type event_type,
 647                                   union sctp_subtype subtype,
 648                                   struct sctp_chunk *chunk,
 649                                   unsigned int error)
 650 {
 651         struct sctp_ulpevent *event;
 652         struct sctp_chunk *abort;
 653
 654         /* Cancel any partial delivery in progress. */
 655         asoc->stream.si->abort_pd(&asoc->ulpq, GFP_ATOMIC);
 656
 657         if (event_type == SCTP_EVENT_T_CHUNK && subtype.chunk == SCTP_CID_ABORT)
 658                 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
 659                                                 (__u16)error, 0, 0, chunk,
 660                                                 GFP_ATOMIC);
 661         else
 662                 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
 663                                                 (__u16)error, 0, 0, NULL,
 664                                                 GFP_ATOMIC);
 665         if (event)
 666                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 667                                 SCTP_ULPEVENT(event));
 668
 669         if (asoc->overall_error_count >= asoc->max_retrans) {
 670                 abort = sctp_make_violation_max_retrans(asoc, chunk);
 671                 if (abort)
 672                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
 673                                         SCTP_CHUNK(abort));
 674         }
 675
 676         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 677                         SCTP_STATE(SCTP_STATE_CLOSED));
 678
 679         /* SEND_FAILED sent later when cleaning up the association. */
 680         asoc->outqueue.error = error;
 681         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 682 }
 683
 684 /* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
 685  * inside the cookie.  In reality, this is only used for INIT-ACK processing
 686  * since all other cases use "temporary" associations and can do all
 687  * their work in statefuns directly.
 688  */
 689 static int sctp_cmd_process_init(struct sctp_cmd_seq *commands,
 690                                  struct sctp_association *asoc,
 691                                  struct sctp_chunk *chunk,
 692                                  struct sctp_init_chunk *peer_init,
 693                                  gfp_t gfp)
 694 {
 695         int error;
 696
 697         /* We only process the init as a sideeffect in a single
 698          * case.   This is when we process the INIT-ACK.   If we
 699          * fail during INIT processing (due to malloc problems),
 700          * just return the error and stop processing the stack.
 701          */
 702         if (!sctp_process_init(asoc, chunk, sctp_source(chunk), peer_init, gfp))
 703                 error = -ENOMEM;
 704         else
 705                 error = 0;
 706
 707         return error;
 708 }
 709
 710 /* Helper function to break out starting up of heartbeat timers.  */
 711 static void sctp_cmd_hb_timers_start(struct sctp_cmd_seq *cmds,
 712                                      struct sctp_association *asoc)
 713 {
 714         struct sctp_transport *t;
 715
 716         /* Start a heartbeat timer for each transport on the association.
 717          * hold a reference on the transport to make sure none of
 718          * the needed data structures go away.
 719          */
 720         list_for_each_entry(t, &asoc->peer.transport_addr_list, transports)
 721                 sctp_transport_reset_hb_timer(t);
 722 }
 723
 724 static void sctp_cmd_hb_timers_stop(struct sctp_cmd_seq *cmds,
 725                                     struct sctp_association *asoc)
 726 {
 727         struct sctp_transport *t;
 728
 729         /* Stop all heartbeat timers. */
 730
 731         list_for_each_entry(t, &asoc->peer.transport_addr_list,
 732                         transports) {
 733                 if (del_timer(&t->hb_timer))
 734                         sctp_transport_put(t);
 735         }
 736 }
 737
 738 /* Helper function to stop any pending T3-RTX timers */
 739 static void sctp_cmd_t3_rtx_timers_stop(struct sctp_cmd_seq *cmds,
 740                                         struct sctp_association *asoc)
 741 {
 742         struct sctp_transport *t;
 743
 744         list_for_each_entry(t, &asoc->peer.transport_addr_list,
 745                         transports) {
 746                 if (del_timer(&t->T3_rtx_timer))
 747                         sctp_transport_put(t);
 748         }
 749 }
 750
 751
 752 /* Helper function to handle the reception of an HEARTBEAT ACK.  */
 753 static void sctp_cmd_transport_on(struct sctp_cmd_seq *cmds,
 754                                   struct sctp_association *asoc,
 755                                   struct sctp_transport *t,
 756                                   struct sctp_chunk *chunk)
 757 {
 758         struct sctp_sender_hb_info *hbinfo;
 759         int was_unconfirmed = 0;
 760
 761         /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
 762          * HEARTBEAT should clear the error counter of the destination
 763          * transport address to which the HEARTBEAT was sent.
 764          */
 765         t->error_count = 0;
 766
 767         /*
 768          * Although RFC4960 specifies that the overall error count must
 769          * be cleared when a HEARTBEAT ACK is received, we make an
 770          * exception while in SHUTDOWN PENDING. If the peer keeps its
 771          * window shut forever, we may never be able to transmit our
 772          * outstanding data and rely on the retransmission limit be reached
 773          * to shutdown the association.
 774          */
 775         if (t->asoc->state < SCTP_STATE_SHUTDOWN_PENDING)
 776                 t->asoc->overall_error_count = 0;
 777
 778         /* Clear the hb_sent flag to signal that we had a good
 779          * acknowledgement.
 780          */
 781         t->hb_sent = 0;
 782
 783         /* Mark the destination transport address as active if it is not so
 784          * marked.
 785          */
 786         if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED)) {
 787                 was_unconfirmed = 1;
 788                 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
 789                                              SCTP_HEARTBEAT_SUCCESS);
 790         }
 791
 792         if (t->state == SCTP_PF)
 793                 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
 794                                              SCTP_HEARTBEAT_SUCCESS);
 795
 796         /* HB-ACK was received for a the proper HB.  Consider this
 797          * forward progress.
 798          */
 799         if (t->dst)
 800                 sctp_transport_dst_confirm(t);
 801
 802         /* The receiver of the HEARTBEAT ACK should also perform an
 803          * RTT measurement for that destination transport address
 804          * using the time value carried in the HEARTBEAT ACK chunk.
 805          * If the transport's rto_pending variable has been cleared,
 806          * it was most likely due to a retransmit.  However, we want
 807          * to re-enable it to properly update the rto.
 808          */
 809         if (t->rto_pending == 0)
 810                 t->rto_pending = 1;
 811
 812         hbinfo = (struct sctp_sender_hb_info *)chunk->skb->data;
 813         sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
 814
 815         /* Update the heartbeat timer.  */
 816         sctp_transport_reset_hb_timer(t);
 817
 818         if (was_unconfirmed && asoc->peer.transport_count == 1)
 819                 sctp_transport_immediate_rtx(t);
 820 }
 821
 822
 823 /* Helper function to process the process SACK command.  */
 824 static int sctp_cmd_process_sack(struct sctp_cmd_seq *cmds,
 825                                  struct sctp_association *asoc,
 826                                  struct sctp_chunk *chunk)
 827 {
 828         int err = 0;
 829
 830         if (sctp_outq_sack(&asoc->outqueue, chunk)) {
 831                 /* There are no more TSNs awaiting SACK.  */
 832                 err = sctp_do_sm(asoc->base.net, SCTP_EVENT_T_OTHER,
 833                                  SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
 834                                  asoc->state, asoc->ep, asoc, NULL,
 835                                  GFP_ATOMIC);
 836         }
 837
 838         return err;
 839 }
 840
 841 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
 842  * the transport for a shutdown chunk.
 843  */
 844 static void sctp_cmd_setup_t2(struct sctp_cmd_seq *cmds,
 845                               struct sctp_association *asoc,
 846                               struct sctp_chunk *chunk)
 847 {
 848         struct sctp_transport *t;
 849
 850         if (chunk->transport)
 851                 t = chunk->transport;
 852         else {
 853                 t = sctp_assoc_choose_alter_transport(asoc,
 854                                               asoc->shutdown_last_sent_to);
 855                 chunk->transport = t;
 856         }
 857         asoc->shutdown_last_sent_to = t;
 858         asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
 859 }
 860
 861 /* Helper function to change the state of an association. */
 862 static void sctp_cmd_new_state(struct sctp_cmd_seq *cmds,
 863                                struct sctp_association *asoc,
 864                                enum sctp_state state)
 865 {
 866         struct sock *sk = asoc->base.sk;
 867
 868         asoc->state = state;
 869
 870         pr_debug("%s: asoc:%p[%s]\n", __func__, asoc, sctp_state_tbl[state]);
 871
 872         if (sctp_style(sk, TCP)) {
 873                 /* Change the sk->sk_state of a TCP-style socket that has
 874                  * successfully completed a connect() call.
 875                  */
 876                 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
 877                         inet_sk_set_state(sk, SCTP_SS_ESTABLISHED);
 878
 879                 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
 880                 if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
 881                     sctp_sstate(sk, ESTABLISHED)) {
 882                         inet_sk_set_state(sk, SCTP_SS_CLOSING);
 883                         sk->sk_shutdown |= RCV_SHUTDOWN;
 884                 }
 885         }
 886
 887         if (sctp_state(asoc, COOKIE_WAIT)) {
 888                 /* Reset init timeouts since they may have been
 889                  * increased due to timer expirations.
 890                  */
 891                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
 892                                                 asoc->rto_initial;
 893                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
 894                                                 asoc->rto_initial;
 895         }
 896
 897         if (sctp_state(asoc, ESTABLISHED)) {
 898                 kfree(asoc->peer.cookie);
 899                 asoc->peer.cookie = NULL;
 900         }
 901
 902         if (sctp_state(asoc, ESTABLISHED) ||
 903             sctp_state(asoc, CLOSED) ||
 904             sctp_state(asoc, SHUTDOWN_RECEIVED)) {
 905                 /* Wake up any processes waiting in the asoc's wait queue in
 906                  * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
 907                  */
 908                 if (waitqueue_active(&asoc->wait))
 909                         wake_up_interruptible(&asoc->wait);
 910
 911                 /* Wake up any processes waiting in the sk's sleep queue of
 912                  * a TCP-style or UDP-style peeled-off socket in
 913                  * sctp_wait_for_accept() or sctp_wait_for_packet().
 914                  * For a UDP-style socket, the waiters are woken up by the
 915                  * notifications.
 916                  */
 917                 if (!sctp_style(sk, UDP))
 918                         sk->sk_state_change(sk);
 919         }
 920
 921         if (sctp_state(asoc, SHUTDOWN_PENDING) &&
 922             !sctp_outq_is_empty(&asoc->outqueue))
 923                 sctp_outq_uncork(&asoc->outqueue, GFP_ATOMIC);
 924 }
 925
 926 /* Helper function to delete an association. */
 927 static void sctp_cmd_delete_tcb(struct sctp_cmd_seq *cmds,
 928                                 struct sctp_association *asoc)
 929 {
 930         struct sock *sk = asoc->base.sk;
 931
 932         /* If it is a non-temporary association belonging to a TCP-style
 933          * listening socket that is not closed, do not free it so that accept()
 934          * can pick it up later.
 935          */
 936         if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
 937             (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
 938                 return;
 939
 940         sctp_association_free(asoc);
 941 }
 942
 943 /*
 944  * ADDIP Section 4.1 ASCONF Chunk Procedures
 945  * A4) Start a T-4 RTO timer, using the RTO value of the selected
 946  * destination address (we use active path instead of primary path just
 947  * because primary path may be inactive.
 948  */
 949 static void sctp_cmd_setup_t4(struct sctp_cmd_seq *cmds,
 950                               struct sctp_association *asoc,
 951                               struct sctp_chunk *chunk)
 952 {
 953         struct sctp_transport *t;
 954
 955         t = sctp_assoc_choose_alter_transport(asoc, chunk->transport);
 956         asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
 957         chunk->transport = t;
 958 }
 959
 960 /* Process an incoming Operation Error Chunk. */
 961 static void sctp_cmd_process_operr(struct sctp_cmd_seq *cmds,
 962                                    struct sctp_association *asoc,
 963                                    struct sctp_chunk *chunk)
 964 {
 965         struct sctp_errhdr *err_hdr;
 966         struct sctp_ulpevent *ev;
 967
 968         while (chunk->chunk_end > chunk->skb->data) {
 969                 err_hdr = (struct sctp_errhdr *)(chunk->skb->data);
 970
 971                 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
 972                                                      GFP_ATOMIC);
 973                 if (!ev)
 974                         return;
 975
 976                 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
 977
 978                 switch (err_hdr->cause) {
 979                 case SCTP_ERROR_UNKNOWN_CHUNK:
 980                 {
 981                         struct sctp_chunkhdr *unk_chunk_hdr;
 982
 983                         unk_chunk_hdr = (struct sctp_chunkhdr *)
 984                                                         err_hdr->variable;
 985                         switch (unk_chunk_hdr->type) {
 986                         /* ADDIP 4.1 A9) If the peer responds to an ASCONF with
 987                          * an ERROR chunk reporting that it did not recognized
 988                          * the ASCONF chunk type, the sender of the ASCONF MUST
 989                          * NOT send any further ASCONF chunks and MUST stop its
 990                          * T-4 timer.
 991                          */
 992                         case SCTP_CID_ASCONF:
 993                                 if (asoc->peer.asconf_capable == 0)
 994                                         break;
 995
 996                                 asoc->peer.asconf_capable = 0;
 997                                 sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
 998                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
 999                                 break;
1000                         default:
1001                                 break;
1002                         }
1003                         break;
1004                 }
1005                 default:
1006                         break;
1007                 }
1008         }
1009 }
1010
1011 /* Helper function to remove the association non-primary peer
1012  * transports.
1013  */
1014 static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
1015 {
1016         struct sctp_transport *t;
1017         struct list_head *temp;
1018         struct list_head *pos;
1019
1020         list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
1021                 t = list_entry(pos, struct sctp_transport, transports);
1022                 if (!sctp_cmp_addr_exact(&t->ipaddr,
1023                                          &asoc->peer.primary_addr)) {
1024                         sctp_assoc_rm_peer(asoc, t);
1025                 }
1026         }
1027 }
1028
1029 /* Helper function to set sk_err on a 1-1 style socket. */
1030 static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
1031 {
1032         struct sock *sk = asoc->base.sk;
1033
1034         if (!sctp_style(sk, UDP))
1035                 sk->sk_err = error;
1036 }
1037
1038 /* Helper function to generate an association change event */
1039 static void sctp_cmd_assoc_change(struct sctp_cmd_seq *commands,
1040                                   struct sctp_association *asoc,
1041                                   u8 state)
1042 {
1043         struct sctp_ulpevent *ev;
1044
1045         ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0,
1046                                             asoc->c.sinit_num_ostreams,
1047                                             asoc->c.sinit_max_instreams,
1048                                             NULL, GFP_ATOMIC);
1049         if (ev)
1050                 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
1051 }
1052
1053 static void sctp_cmd_peer_no_auth(struct sctp_cmd_seq *commands,
1054                                   struct sctp_association *asoc)
1055 {
1056         struct sctp_ulpevent *ev;
1057
1058         ev = sctp_ulpevent_make_authkey(asoc, 0, SCTP_AUTH_NO_AUTH, GFP_ATOMIC);
1059         if (ev)
1060                 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
1061 }
1062
1063 /* Helper function to generate an adaptation indication event */
1064 static void sctp_cmd_adaptation_ind(struct sctp_cmd_seq *commands,
1065                                     struct sctp_association *asoc)
1066 {
1067         struct sctp_ulpevent *ev;
1068
1069         ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
1070
1071         if (ev)
1072                 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
1073 }
1074
1075
1076 static void sctp_cmd_t1_timer_update(struct sctp_association *asoc,
1077                                      enum sctp_event_timeout timer,
1078                                      char *name)
1079 {
1080         struct sctp_transport *t;
1081
1082         t = asoc->init_last_sent_to;
1083         asoc->init_err_counter++;
1084
1085         if (t->init_sent_count > (asoc->init_cycle + 1)) {
1086                 asoc->timeouts[timer] *= 2;
1087                 if (asoc->timeouts[timer] > asoc->max_init_timeo) {
1088                         asoc->timeouts[timer] = asoc->max_init_timeo;
1089                 }
1090                 asoc->init_cycle++;
1091
1092                 pr_debug("%s: T1[%s] timeout adjustment init_err_counter:%d"
1093                          " cycle:%d timeout:%ld\n", __func__, name,
1094                          asoc->init_err_counter, asoc->init_cycle,
1095                          asoc->timeouts[timer]);
1096         }
1097
1098 }
1099
1100 /* Send the whole message, chunk by chunk, to the outqueue.
1101  * This way the whole message is queued up and bundling if
1102  * encouraged for small fragments.
1103  */
1104 static void sctp_cmd_send_msg(struct sctp_association *asoc,
1105                               struct sctp_datamsg *msg, gfp_t gfp)
1106 {
1107         struct sctp_chunk *chunk;
1108
1109         list_for_each_entry(chunk, &msg->chunks, frag_list)
1110                 sctp_outq_tail(&asoc->outqueue, chunk, gfp);
1111
1112         asoc->outqueue.sched->enqueue(&asoc->outqueue, msg);
1113 }
1114
1115
1116 /* These three macros allow us to pull the debugging code out of the
1117  * main flow of sctp_do_sm() to keep attention focused on the real
1118  * functionality there.
1119  */
1120 #define debug_pre_sfn() \
1121         pr_debug("%s[pre-fn]: ep:%p, %s, %s, asoc:%p[%s], %s\n", __func__, \
1122                  ep, sctp_evttype_tbl[event_type], (*debug_fn)(subtype),   \
1123                  asoc, sctp_state_tbl[state], state_fn->name)
1124
1125 #define debug_post_sfn() \
1126         pr_debug("%s[post-fn]: asoc:%p, status:%s\n", __func__, asoc, \
1127                  sctp_status_tbl[status])
1128
1129 #define debug_post_sfx() \
1130         pr_debug("%s[post-sfx]: error:%d, asoc:%p[%s]\n", __func__, error, \
1131                  asoc, sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
1132                  sctp_assoc2id(asoc))) ? asoc->state : SCTP_STATE_CLOSED])
1133
1134 /*
1135  * This is the master state machine processing function.
1136  *
1137  * If you want to understand all of lksctp, this is a
1138  * good place to start.
1139  */
1140 int sctp_do_sm(struct net *net, enum sctp_event_type event_type,
1141                union sctp_subtype subtype, enum sctp_state state,
1142                struct sctp_endpoint *ep, struct sctp_association *asoc,
1143                void *event_arg, gfp_t gfp)
1144 {
1145         typedef const char *(printfn_t)(union sctp_subtype);
1146         static printfn_t *table[] = {
1147                 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
1148         };
1149         printfn_t *debug_fn  __attribute__ ((unused)) = table[event_type];
1150         const struct sctp_sm_table_entry *state_fn;
1151         struct sctp_cmd_seq commands;
1152         enum sctp_disposition status;
1153         int error = 0;
1154
1155         /* Look up the state function, run it, and then process the
1156          * side effects.  These three steps are the heart of lksctp.
1157          */
1158         state_fn = sctp_sm_lookup_event(net, event_type, state, subtype);
1159
1160         sctp_init_cmd_seq(&commands);
1161
1162         debug_pre_sfn();
1163         status = state_fn->fn(net, ep, asoc, subtype, event_arg, &commands);
1164         debug_post_sfn();
1165
1166         error = sctp_side_effects(event_type, subtype, state,
1167                                   ep, &asoc, event_arg, status,
1168                                   &commands, gfp);
1169         debug_post_sfx();
1170
1171         return error;
1172 }
1173
1174 /*****************************************************************
1175  * This the master state function side effect processing function.
1176  *****************************************************************/
1177 static int sctp_side_effects(enum sctp_event_type event_type,
1178                              union sctp_subtype subtype,
1179                              enum sctp_state state,
1180                              struct sctp_endpoint *ep,
1181                              struct sctp_association **asoc,
1182                              void *event_arg,
1183                              enum sctp_disposition status,
1184                              struct sctp_cmd_seq *commands,
1185                              gfp_t gfp)
1186 {
1187         int error;
1188
1189         /* FIXME - Most of the dispositions left today would be categorized
1190          * as "exceptional" dispositions.  For those dispositions, it
1191          * may not be proper to run through any of the commands at all.
1192          * For example, the command interpreter might be run only with
1193          * disposition SCTP_DISPOSITION_CONSUME.
1194          */
1195         if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
1196                                                ep, *asoc,
1197                                                event_arg, status,
1198                                                commands, gfp)))
1199                 goto bail;
1200
1201         switch (status) {
1202         case SCTP_DISPOSITION_DISCARD:
1203                 pr_debug("%s: ignored sctp protocol event - state:%d, "
1204                          "event_type:%d, event_id:%d\n", __func__, state,
1205                          event_type, subtype.chunk);
1206                 break;
1207
1208         case SCTP_DISPOSITION_NOMEM:
1209                 /* We ran out of memory, so we need to discard this
1210                  * packet.
1211                  */
1212                 /* BUG--we should now recover some memory, probably by
1213                  * reneging...
1214                  */
1215                 error = -ENOMEM;
1216                 break;
1217
1218         case SCTP_DISPOSITION_DELETE_TCB:
1219         case SCTP_DISPOSITION_ABORT:
1220                 /* This should now be a command. */
1221                 *asoc = NULL;
1222                 break;
1223
1224         case SCTP_DISPOSITION_CONSUME:
1225                 /*
1226                  * We should no longer have much work to do here as the
1227                  * real work has been done as explicit commands above.
1228                  */
1229                 break;
1230
1231         case SCTP_DISPOSITION_VIOLATION:
1232                 net_err_ratelimited("protocol violation state %d chunkid %d\n",
1233                                     state, subtype.chunk);
1234                 break;
1235
1236         case SCTP_DISPOSITION_NOT_IMPL:
1237                 pr_warn("unimplemented feature in state %d, event_type %d, event_id %d\n",
1238                         state, event_type, subtype.chunk);
1239                 break;
1240
1241         case SCTP_DISPOSITION_BUG:
1242                 pr_err("bug in state %d, event_type %d, event_id %d\n",
1243                        state, event_type, subtype.chunk);
1244                 BUG();
1245                 break;
1246
1247         default:
1248                 pr_err("impossible disposition %d in state %d, event_type %d, event_id %d\n",
1249                        status, state, event_type, subtype.chunk);
1250                 BUG();
1251                 break;
1252         }
1253
1254 bail:
1255         return error;
1256 }
1257
1258 /********************************************************************
1259  * 2nd Level Abstractions
1260  ********************************************************************/
1261
1262 /* This is the side-effect interpreter.  */
1263 static int sctp_cmd_interpreter(enum sctp_event_type event_type,
1264                                 union sctp_subtype subtype,
1265                                 enum sctp_state state,
1266                                 struct sctp_endpoint *ep,
1267                                 struct sctp_association *asoc,
1268                                 void *event_arg,
1269                                 enum sctp_disposition status,
1270                                 struct sctp_cmd_seq *commands,
1271                                 gfp_t gfp)
1272 {
1273         struct sctp_sock *sp = sctp_sk(ep->base.sk);
1274         struct sctp_chunk *chunk = NULL, *new_obj;
1275         struct sctp_packet *packet;
1276         struct sctp_sackhdr sackh;
1277         struct timer_list *timer;
1278         struct sctp_transport *t;
1279         unsigned long timeout;
1280         struct sctp_cmd *cmd;
1281         int local_cork = 0;
1282         int error = 0;
1283         int force;
1284
1285         if (SCTP_EVENT_T_TIMEOUT != event_type)
1286                 chunk = event_arg;
1287
1288         /* Note:  This whole file is a huge candidate for rework.
1289          * For example, each command could either have its own handler, so
1290          * the loop would look like:
1291          *     while (cmds)
1292          *         cmd->handle(x, y, z)
1293          * --jgrimm
1294          */
1295         while (NULL != (cmd = sctp_next_cmd(commands))) {
1296                 switch (cmd->verb) {
1297                 case SCTP_CMD_NOP:
1298                         /* Do nothing. */
1299                         break;
1300
1301                 case SCTP_CMD_NEW_ASOC:
1302                         /* Register a new association.  */
1303                         if (local_cork) {
1304                                 sctp_outq_uncork(&asoc->outqueue, gfp);
1305                                 local_cork = 0;
1306                         }
1307
1308                         /* Register with the endpoint.  */
1309                         asoc = cmd->obj.asoc;
1310                         BUG_ON(asoc->peer.primary_path == NULL);
1311                         sctp_endpoint_add_asoc(ep, asoc);
1312                         break;
1313
1314                 case SCTP_CMD_PURGE_OUTQUEUE:
1315                        sctp_outq_teardown(&asoc->outqueue);
1316                        break;
1317
1318                 case SCTP_CMD_DELETE_TCB:
1319                         if (local_cork) {
1320                                 sctp_outq_uncork(&asoc->outqueue, gfp);
1321                                 local_cork = 0;
1322                         }
1323                         /* Delete the current association.  */
1324                         sctp_cmd_delete_tcb(commands, asoc);
1325                         asoc = NULL;
1326                         break;
1327
1328                 case SCTP_CMD_NEW_STATE:
1329                         /* Enter a new state.  */
1330                         sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1331                         break;
1332
1333                 case SCTP_CMD_REPORT_TSN:
1334                         /* Record the arrival of a TSN.  */
1335                         error = sctp_tsnmap_mark(&asoc->peer.tsn_map,
1336                                                  cmd->obj.u32, NULL);
1337                         break;
1338
1339                 case SCTP_CMD_REPORT_FWDTSN:
1340                         asoc->stream.si->report_ftsn(&asoc->ulpq, cmd->obj.u32);
1341                         break;
1342
1343                 case SCTP_CMD_PROCESS_FWDTSN:
1344                         asoc->stream.si->handle_ftsn(&asoc->ulpq,
1345                                                      cmd->obj.chunk);
1346                         break;
1347
1348                 case SCTP_CMD_GEN_SACK:
1349                         /* Generate a Selective ACK.
1350                          * The argument tells us whether to just count
1351                          * the packet and MAYBE generate a SACK, or
1352                          * force a SACK out.
1353                          */
1354                         force = cmd->obj.i32;
1355                         error = sctp_gen_sack(asoc, force, commands);
1356                         break;
1357
1358                 case SCTP_CMD_PROCESS_SACK:
1359                         /* Process an inbound SACK.  */
1360                         error = sctp_cmd_process_sack(commands, asoc,
1361                                                       cmd->obj.chunk);
1362                         break;
1363
1364                 case SCTP_CMD_GEN_INIT_ACK:
1365                         /* Generate an INIT ACK chunk.  */
1366                         new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1367                                                      0);
1368                         if (!new_obj) {
1369                                 error = -ENOMEM;
1370                                 break;
1371                         }
1372
1373                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1374                                         SCTP_CHUNK(new_obj));
1375                         break;
1376
1377                 case SCTP_CMD_PEER_INIT:
1378                         /* Process a unified INIT from the peer.
1379                          * Note: Only used during INIT-ACK processing.  If
1380                          * there is an error just return to the outter
1381                          * layer which will bail.
1382                          */
1383                         error = sctp_cmd_process_init(commands, asoc, chunk,
1384                                                       cmd->obj.init, gfp);
1385                         break;
1386
1387                 case SCTP_CMD_GEN_COOKIE_ECHO:
1388                         /* Generate a COOKIE ECHO chunk.  */
1389                         new_obj = sctp_make_cookie_echo(asoc, chunk);
1390                         if (!new_obj) {
1391                                 if (cmd->obj.chunk)
1392                                         sctp_chunk_free(cmd->obj.chunk);
1393                                 error = -ENOMEM;
1394                                 break;
1395                         }
1396                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1397                                         SCTP_CHUNK(new_obj));
1398
1399                         /* If there is an ERROR chunk to be sent along with
1400                          * the COOKIE_ECHO, send it, too.
1401                          */
1402                         if (cmd->obj.chunk)
1403                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1404                                                 SCTP_CHUNK(cmd->obj.chunk));
1405
1406                         if (new_obj->transport) {
1407                                 new_obj->transport->init_sent_count++;
1408                                 asoc->init_last_sent_to = new_obj->transport;
1409                         }
1410
1411                         /* FIXME - Eventually come up with a cleaner way to
1412                          * enabling COOKIE-ECHO + DATA bundling during
1413                          * multihoming stale cookie scenarios, the following
1414                          * command plays with asoc->peer.retran_path to
1415                          * avoid the problem of sending the COOKIE-ECHO and
1416                          * DATA in different paths, which could result
1417                          * in the association being ABORTed if the DATA chunk
1418                          * is processed first by the server.  Checking the
1419                          * init error counter simply causes this command
1420                          * to be executed only during failed attempts of
1421                          * association establishment.
1422                          */
1423                         if ((asoc->peer.retran_path !=
1424                              asoc->peer.primary_path) &&
1425                             (asoc->init_err_counter > 0)) {
1426                                 sctp_add_cmd_sf(commands,
1427                                                 SCTP_CMD_FORCE_PRIM_RETRAN,
1428                                                 SCTP_NULL());
1429                         }
1430
1431                         break;
1432
1433                 case SCTP_CMD_GEN_SHUTDOWN:
1434                         /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1435                          * Reset error counts.
1436                          */
1437                         asoc->overall_error_count = 0;
1438
1439                         /* Generate a SHUTDOWN chunk.  */
1440                         new_obj = sctp_make_shutdown(asoc, chunk);
1441                         if (!new_obj) {
1442                                 error = -ENOMEM;
1443                                 break;
1444                         }
1445                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1446                                         SCTP_CHUNK(new_obj));
1447                         break;
1448
1449                 case SCTP_CMD_CHUNK_ULP:
1450                         /* Send a chunk to the sockets layer.  */
1451                         pr_debug("%s: sm_sideff: chunk_up:%p, ulpq:%p\n",
1452                                  __func__, cmd->obj.chunk, &asoc->ulpq);
1453
1454                         asoc->stream.si->ulpevent_data(&asoc->ulpq,
1455                                                        cmd->obj.chunk,
1456                                                        GFP_ATOMIC);
1457                         break;
1458
1459                 case SCTP_CMD_EVENT_ULP:
1460                         /* Send a notification to the sockets layer.  */
1461                         pr_debug("%s: sm_sideff: event_up:%p, ulpq:%p\n",
1462                                  __func__, cmd->obj.ulpevent, &asoc->ulpq);
1463
1464                         asoc->stream.si->enqueue_event(&asoc->ulpq,
1465                                                        cmd->obj.ulpevent);
1466                         break;
1467
1468                 case SCTP_CMD_REPLY:
1469                         /* If an caller has not already corked, do cork. */
1470                         if (!asoc->outqueue.cork) {
1471                                 sctp_outq_cork(&asoc->outqueue);
1472                                 local_cork = 1;
1473                         }
1474                         /* Send a chunk to our peer.  */
1475                         sctp_outq_tail(&asoc->outqueue, cmd->obj.chunk, gfp);
1476                         break;
1477
1478                 case SCTP_CMD_SEND_PKT:
1479                         /* Send a full packet to our peer.  */
1480                         packet = cmd->obj.packet;
1481                         sctp_packet_transmit(packet, gfp);
1482                         sctp_ootb_pkt_free(packet);
1483                         break;
1484
1485                 case SCTP_CMD_T1_RETRAN:
1486                         /* Mark a transport for retransmission.  */
1487                         sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1488                                         SCTP_RTXR_T1_RTX);
1489                         break;
1490
1491                 case SCTP_CMD_RETRAN:
1492                         /* Mark a transport for retransmission.  */
1493                         sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1494                                         SCTP_RTXR_T3_RTX);
1495                         break;
1496
1497                 case SCTP_CMD_ECN_CE:
1498                         /* Do delayed CE processing.   */
1499                         sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1500                         break;
1501
1502                 case SCTP_CMD_ECN_ECNE:
1503                         /* Do delayed ECNE processing. */
1504                         new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1505                                                         chunk);
1506                         if (new_obj)
1507                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1508                                                 SCTP_CHUNK(new_obj));
1509                         break;
1510
1511                 case SCTP_CMD_ECN_CWR:
1512                         /* Do delayed CWR processing.  */
1513                         sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1514                         break;
1515
1516                 case SCTP_CMD_SETUP_T2:
1517                         sctp_cmd_setup_t2(commands, asoc, cmd->obj.chunk);
1518                         break;
1519
1520                 case SCTP_CMD_TIMER_START_ONCE:
1521                         timer = &asoc->timers[cmd->obj.to];
1522
1523                         if (timer_pending(timer))
1524                                 break;
1525                         fallthrough;
1526
1527                 case SCTP_CMD_TIMER_START:
1528                         timer = &asoc->timers[cmd->obj.to];
1529                         timeout = asoc->timeouts[cmd->obj.to];
1530                         BUG_ON(!timeout);
1531
1532                         /*
1533                          * SCTP has a hard time with timer starts.  Because we process
1534                          * timer starts as side effects, it can be hard to tell if we
1535                          * have already started a timer or not, which leads to BUG
1536                          * halts when we call add_timer. So here, instead of just starting
1537                          * a timer, if the timer is already started, and just mod
1538                          * the timer with the shorter of the two expiration times
1539                          */
1540                         if (!timer_pending(timer))
1541                                 sctp_association_hold(asoc);
1542                         timer_reduce(timer, jiffies + timeout);
1543                         break;
1544
1545                 case SCTP_CMD_TIMER_RESTART:
1546                         timer = &asoc->timers[cmd->obj.to];
1547                         timeout = asoc->timeouts[cmd->obj.to];
1548                         if (!mod_timer(timer, jiffies + timeout))
1549                                 sctp_association_hold(asoc);
1550                         break;
1551
1552                 case SCTP_CMD_TIMER_STOP:
1553                         timer = &asoc->timers[cmd->obj.to];
1554                         if (del_timer(timer))
1555                                 sctp_association_put(asoc);
1556                         break;
1557
1558                 case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1559                         chunk = cmd->obj.chunk;
1560                         t = sctp_assoc_choose_alter_transport(asoc,
1561                                                 asoc->init_last_sent_to);
1562                         asoc->init_last_sent_to = t;
1563                         chunk->transport = t;
1564                         t->init_sent_count++;
1565                         /* Set the new transport as primary */
1566                         sctp_assoc_set_primary(asoc, t);
1567                         break;
1568
1569                 case SCTP_CMD_INIT_RESTART:
1570                         /* Do the needed accounting and updates
1571                          * associated with restarting an initialization
1572                          * timer. Only multiply the timeout by two if
1573                          * all transports have been tried at the current
1574                          * timeout.
1575                          */
1576                         sctp_cmd_t1_timer_update(asoc,
1577                                                 SCTP_EVENT_TIMEOUT_T1_INIT,
1578                                                 "INIT");
1579
1580                         sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1581                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1582                         break;
1583
1584                 case SCTP_CMD_COOKIEECHO_RESTART:
1585                         /* Do the needed accounting and updates
1586                          * associated with restarting an initialization
1587                          * timer. Only multiply the timeout by two if
1588                          * all transports have been tried at the current
1589                          * timeout.
1590                          */
1591                         sctp_cmd_t1_timer_update(asoc,
1592                                                 SCTP_EVENT_TIMEOUT_T1_COOKIE,
1593                                                 "COOKIE");
1594
1595                         /* If we've sent any data bundled with
1596                          * COOKIE-ECHO we need to resend.
1597                          */
1598                         list_for_each_entry(t, &asoc->peer.transport_addr_list,
1599                                         transports) {
1600                                 sctp_retransmit_mark(&asoc->outqueue, t,
1601                                             SCTP_RTXR_T1_RTX);
1602                         }
1603
1604                         sctp_add_cmd_sf(commands,
1605                                         SCTP_CMD_TIMER_RESTART,
1606                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1607                         break;
1608
1609                 case SCTP_CMD_INIT_FAILED:
1610                         sctp_cmd_init_failed(commands, asoc, cmd->obj.u16);
1611                         break;
1612
1613                 case SCTP_CMD_ASSOC_FAILED:
1614                         sctp_cmd_assoc_failed(commands, asoc, event_type,
1615                                               subtype, chunk, cmd->obj.u16);
1616                         break;
1617
1618                 case SCTP_CMD_INIT_COUNTER_INC:
1619                         asoc->init_err_counter++;
1620                         break;
1621
1622                 case SCTP_CMD_INIT_COUNTER_RESET:
1623                         asoc->init_err_counter = 0;
1624                         asoc->init_cycle = 0;
1625                         list_for_each_entry(t, &asoc->peer.transport_addr_list,
1626                                             transports) {
1627                                 t->init_sent_count = 0;
1628                         }
1629                         break;
1630
1631                 case SCTP_CMD_REPORT_DUP:
1632                         sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1633                                              cmd->obj.u32);
1634                         break;
1635
1636                 case SCTP_CMD_REPORT_BAD_TAG:
1637                         pr_debug("%s: vtag mismatch!\n", __func__);
1638                         break;
1639
1640                 case SCTP_CMD_STRIKE:
1641                         /* Mark one strike against a transport.  */
1642                         sctp_do_8_2_transport_strike(commands, asoc,
1643                                                     cmd->obj.transport, 0);
1644                         break;
1645
1646                 case SCTP_CMD_TRANSPORT_IDLE:
1647                         t = cmd->obj.transport;
1648                         sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
1649                         break;
1650
1651                 case SCTP_CMD_TRANSPORT_HB_SENT:
1652                         t = cmd->obj.transport;
1653                         sctp_do_8_2_transport_strike(commands, asoc,
1654                                                      t, 1);
1655                         t->hb_sent = 1;
1656                         break;
1657
1658                 case SCTP_CMD_TRANSPORT_ON:
1659                         t = cmd->obj.transport;
1660                         sctp_cmd_transport_on(commands, asoc, t, chunk);
1661                         break;
1662
1663                 case SCTP_CMD_HB_TIMERS_START:
1664                         sctp_cmd_hb_timers_start(commands, asoc);
1665                         break;
1666
1667                 case SCTP_CMD_HB_TIMER_UPDATE:
1668                         t = cmd->obj.transport;
1669                         sctp_transport_reset_hb_timer(t);
1670                         break;
1671
1672                 case SCTP_CMD_HB_TIMERS_STOP:
1673                         sctp_cmd_hb_timers_stop(commands, asoc);
1674                         break;
1675
1676                 case SCTP_CMD_PROBE_TIMER_UPDATE:
1677                         t = cmd->obj.transport;
1678                         sctp_transport_reset_probe_timer(t);
1679                         break;
1680
1681                 case SCTP_CMD_REPORT_ERROR:
1682                         error = cmd->obj.error;
1683                         break;
1684
1685                 case SCTP_CMD_PROCESS_CTSN:
1686                         /* Dummy up a SACK for processing. */
1687                         sackh.cum_tsn_ack = cmd->obj.be32;
1688                         sackh.a_rwnd = htonl(asoc->peer.rwnd +
1689                                              asoc->outqueue.outstanding_bytes);
1690                         sackh.num_gap_ack_blocks = 0;
1691                         sackh.num_dup_tsns = 0;
1692                         chunk->subh.sack_hdr = &sackh;
1693                         sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1694                                         SCTP_CHUNK(chunk));
1695                         break;
1696
1697                 case SCTP_CMD_DISCARD_PACKET:
1698                         /* We need to discard the whole packet.
1699                          * Uncork the queue since there might be
1700                          * responses pending
1701                          */
1702                         chunk->pdiscard = 1;
1703                         if (asoc) {
1704                                 sctp_outq_uncork(&asoc->outqueue, gfp);
1705                                 local_cork = 0;
1706                         }
1707                         break;
1708
1709                 case SCTP_CMD_RTO_PENDING:
1710                         t = cmd->obj.transport;
1711                         t->rto_pending = 1;
1712                         break;
1713
1714                 case SCTP_CMD_PART_DELIVER:
1715                         asoc->stream.si->start_pd(&asoc->ulpq, GFP_ATOMIC);
1716                         break;
1717
1718                 case SCTP_CMD_RENEGE:
1719                         asoc->stream.si->renege_events(&asoc->ulpq,
1720                                                        cmd->obj.chunk,
1721                                                        GFP_ATOMIC);
1722                         break;
1723
1724                 case SCTP_CMD_SETUP_T4:
1725                         sctp_cmd_setup_t4(commands, asoc, cmd->obj.chunk);
1726                         break;
1727
1728                 case SCTP_CMD_PROCESS_OPERR:
1729                         sctp_cmd_process_operr(commands, asoc, chunk);
1730                         break;
1731                 case SCTP_CMD_CLEAR_INIT_TAG:
1732                         asoc->peer.i.init_tag = 0;
1733                         break;
1734                 case SCTP_CMD_DEL_NON_PRIMARY:
1735                         sctp_cmd_del_non_primary(asoc);
1736                         break;
1737                 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1738                         sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1739                         break;
1740                 case SCTP_CMD_FORCE_PRIM_RETRAN:
1741                         t = asoc->peer.retran_path;
1742                         asoc->peer.retran_path = asoc->peer.primary_path;
1743                         sctp_outq_uncork(&asoc->outqueue, gfp);
1744                         local_cork = 0;
1745                         asoc->peer.retran_path = t;
1746                         break;
1747                 case SCTP_CMD_SET_SK_ERR:
1748                         sctp_cmd_set_sk_err(asoc, cmd->obj.error);
1749                         break;
1750                 case SCTP_CMD_ASSOC_CHANGE:
1751                         sctp_cmd_assoc_change(commands, asoc,
1752                                               cmd->obj.u8);
1753                         break;
1754                 case SCTP_CMD_ADAPTATION_IND:
1755                         sctp_cmd_adaptation_ind(commands, asoc);
1756                         break;
1757                 case SCTP_CMD_PEER_NO_AUTH:
1758                         sctp_cmd_peer_no_auth(commands, asoc);
1759                         break;
1760
1761                 case SCTP_CMD_ASSOC_SHKEY:
1762                         error = sctp_auth_asoc_init_active_key(asoc,
1763                                                 GFP_ATOMIC);
1764                         break;
1765                 case SCTP_CMD_UPDATE_INITTAG:
1766                         asoc->peer.i.init_tag = cmd->obj.u32;
1767                         break;
1768                 case SCTP_CMD_SEND_MSG:
1769                         if (!asoc->outqueue.cork) {
1770                                 sctp_outq_cork(&asoc->outqueue);
1771                                 local_cork = 1;
1772                         }
1773                         sctp_cmd_send_msg(asoc, cmd->obj.msg, gfp);
1774                         break;
1775                 case SCTP_CMD_PURGE_ASCONF_QUEUE:
1776                         sctp_asconf_queue_teardown(asoc);
1777                         break;
1778
1779                 case SCTP_CMD_SET_ASOC:
1780                         if (asoc && local_cork) {
1781                                 sctp_outq_uncork(&asoc->outqueue, gfp);
1782                                 local_cork = 0;
1783                         }
1784                         asoc = cmd->obj.asoc;
1785                         break;
1786
1787                 default:
1788                         pr_warn("Impossible command: %u\n",
1789                                 cmd->verb);
1790                         break;
1791                 }
1792
1793                 if (error) {
1794                         cmd = sctp_next_cmd(commands);
1795                         while (cmd) {
1796                                 if (cmd->verb == SCTP_CMD_REPLY)
1797                                         sctp_chunk_free(cmd->obj.chunk);
1798                                 cmd = sctp_next_cmd(commands);
1799                         }
1800                         break;
1801                 }
1802         }
1803
1804         /* If this is in response to a received chunk, wait until
1805          * we are done with the packet to open the queue so that we don't
1806          * send multiple packets in response to a single request.
1807          */
1808         if (asoc && SCTP_EVENT_T_CHUNK == event_type && chunk) {
1809                 if (chunk->end_of_packet || chunk->singleton)
1810                         sctp_outq_uncork(&asoc->outqueue, gfp);
1811         } else if (local_cork)
1812                 sctp_outq_uncork(&asoc->outqueue, gfp);
1813
1814         if (sp->data_ready_signalled)
1815                 sp->data_ready_signalled = 0;
1816
1817         return error;
1818 }