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 /* Inject a SACK Timeout event into the state machine.  */
 475 static void sctp_generate_sack_event(struct timer_list *t)
 476 {
 477         struct sctp_association *asoc =
 478                 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_SACK]);
 479
 480         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
 481 }
 482
 483 sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
 484         [SCTP_EVENT_TIMEOUT_NONE] =             NULL,
 485         [SCTP_EVENT_TIMEOUT_T1_COOKIE] =        sctp_generate_t1_cookie_event,
 486         [SCTP_EVENT_TIMEOUT_T1_INIT] =          sctp_generate_t1_init_event,
 487         [SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] =      sctp_generate_t2_shutdown_event,
 488         [SCTP_EVENT_TIMEOUT_T3_RTX] =           NULL,
 489         [SCTP_EVENT_TIMEOUT_T4_RTO] =           sctp_generate_t4_rto_event,
 490         [SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD] =
 491                                         sctp_generate_t5_shutdown_guard_event,
 492         [SCTP_EVENT_TIMEOUT_HEARTBEAT] =        NULL,
 493         [SCTP_EVENT_TIMEOUT_RECONF] =           NULL,
 494         [SCTP_EVENT_TIMEOUT_SACK] =             sctp_generate_sack_event,
 495         [SCTP_EVENT_TIMEOUT_AUTOCLOSE] =        sctp_generate_autoclose_event,
 496 };
 497
 498
 499 /* RFC 2960 8.2 Path Failure Detection
 500  *
 501  * When its peer endpoint is multi-homed, an endpoint should keep a
 502  * error counter for each of the destination transport addresses of the
 503  * peer endpoint.
 504  *
 505  * Each time the T3-rtx timer expires on any address, or when a
 506  * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
 507  * the error counter of that destination address will be incremented.
 508  * When the value in the error counter exceeds the protocol parameter
 509  * 'Path.Max.Retrans' of that destination address, the endpoint should
 510  * mark the destination transport address as inactive, and a
 511  * notification SHOULD be sent to the upper layer.
 512  *
 513  */
 514 static void sctp_do_8_2_transport_strike(struct sctp_cmd_seq *commands,
 515                                          struct sctp_association *asoc,
 516                                          struct sctp_transport *transport,
 517                                          int is_hb)
 518 {
 519         /* The check for association's overall error counter exceeding the
 520          * threshold is done in the state function.
 521          */
 522         /* We are here due to a timer expiration.  If the timer was
 523          * not a HEARTBEAT, then normal error tracking is done.
 524          * If the timer was a heartbeat, we only increment error counts
 525          * when we already have an outstanding HEARTBEAT that has not
 526          * been acknowledged.
 527          * Additionally, some tranport states inhibit error increments.
 528          */
 529         if (!is_hb) {
 530                 asoc->overall_error_count++;
 531                 if (transport->state != SCTP_INACTIVE)
 532                         transport->error_count++;
 533          } else if (transport->hb_sent) {
 534                 if (transport->state != SCTP_UNCONFIRMED)
 535                         asoc->overall_error_count++;
 536                 if (transport->state != SCTP_INACTIVE)
 537                         transport->error_count++;
 538         }
 539
 540         /* If the transport error count is greater than the pf_retrans
 541          * threshold, and less than pathmaxrtx, and if the current state
 542          * is SCTP_ACTIVE, then mark this transport as Partially Failed,
 543          * see SCTP Quick Failover Draft, section 5.1
 544          */
 545         if (asoc->base.net->sctp.pf_enable &&
 546             transport->state == SCTP_ACTIVE &&
 547             transport->error_count < transport->pathmaxrxt &&
 548             transport->error_count > transport->pf_retrans) {
 549
 550                 sctp_assoc_control_transport(asoc, transport,
 551                                              SCTP_TRANSPORT_PF,
 552                                              0);
 553
 554                 /* Update the hb timer to resend a heartbeat every rto */
 555                 sctp_transport_reset_hb_timer(transport);
 556         }
 557
 558         if (transport->state != SCTP_INACTIVE &&
 559             (transport->error_count > transport->pathmaxrxt)) {
 560                 pr_debug("%s: association:%p transport addr:%pISpc failed\n",
 561                          __func__, asoc, &transport->ipaddr.sa);
 562
 563                 sctp_assoc_control_transport(asoc, transport,
 564                                              SCTP_TRANSPORT_DOWN,
 565                                              SCTP_FAILED_THRESHOLD);
 566         }
 567
 568         if (transport->error_count > transport->ps_retrans &&
 569             asoc->peer.primary_path == transport &&
 570             asoc->peer.active_path != transport)
 571                 sctp_assoc_set_primary(asoc, asoc->peer.active_path);
 572
 573         /* E2) For the destination address for which the timer
 574          * expires, set RTO <- RTO * 2 ("back off the timer").  The
 575          * maximum value discussed in rule C7 above (RTO.max) may be
 576          * used to provide an upper bound to this doubling operation.
 577          *
 578          * Special Case:  the first HB doesn't trigger exponential backoff.
 579          * The first unacknowledged HB triggers it.  We do this with a flag
 580          * that indicates that we have an outstanding HB.
 581          */
 582         if (!is_hb || transport->hb_sent) {
 583                 transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
 584                 sctp_max_rto(asoc, transport);
 585         }
 586 }
 587
 588 /* Worker routine to handle INIT command failure.  */
 589 static void sctp_cmd_init_failed(struct sctp_cmd_seq *commands,
 590                                  struct sctp_association *asoc,
 591                                  unsigned int error)
 592 {
 593         struct sctp_ulpevent *event;
 594
 595         event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_CANT_STR_ASSOC,
 596                                                 (__u16)error, 0, 0, NULL,
 597                                                 GFP_ATOMIC);
 598
 599         if (event)
 600                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 601                                 SCTP_ULPEVENT(event));
 602
 603         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 604                         SCTP_STATE(SCTP_STATE_CLOSED));
 605
 606         /* SEND_FAILED sent later when cleaning up the association. */
 607         asoc->outqueue.error = error;
 608         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 609 }
 610
 611 /* Worker routine to handle SCTP_CMD_ASSOC_FAILED.  */
 612 static void sctp_cmd_assoc_failed(struct sctp_cmd_seq *commands,
 613                                   struct sctp_association *asoc,
 614                                   enum sctp_event_type event_type,
 615                                   union sctp_subtype subtype,
 616                                   struct sctp_chunk *chunk,
 617                                   unsigned int error)
 618 {
 619         struct sctp_ulpevent *event;
 620         struct sctp_chunk *abort;
 621
 622         /* Cancel any partial delivery in progress. */
 623         asoc->stream.si->abort_pd(&asoc->ulpq, GFP_ATOMIC);
 624
 625         if (event_type == SCTP_EVENT_T_CHUNK && subtype.chunk == SCTP_CID_ABORT)
 626                 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
 627                                                 (__u16)error, 0, 0, chunk,
 628                                                 GFP_ATOMIC);
 629         else
 630                 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
 631                                                 (__u16)error, 0, 0, NULL,
 632                                                 GFP_ATOMIC);
 633         if (event)
 634                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 635                                 SCTP_ULPEVENT(event));
 636
 637         if (asoc->overall_error_count >= asoc->max_retrans) {
 638                 abort = sctp_make_violation_max_retrans(asoc, chunk);
 639                 if (abort)
 640                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
 641                                         SCTP_CHUNK(abort));
 642         }
 643
 644         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 645                         SCTP_STATE(SCTP_STATE_CLOSED));
 646
 647         /* SEND_FAILED sent later when cleaning up the association. */
 648         asoc->outqueue.error = error;
 649         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 650 }
 651
 652 /* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
 653  * inside the cookie.  In reality, this is only used for INIT-ACK processing
 654  * since all other cases use "temporary" associations and can do all
 655  * their work in statefuns directly.
 656  */
 657 static int sctp_cmd_process_init(struct sctp_cmd_seq *commands,
 658                                  struct sctp_association *asoc,
 659                                  struct sctp_chunk *chunk,
 660                                  struct sctp_init_chunk *peer_init,
 661                                  gfp_t gfp)
 662 {
 663         int error;
 664
 665         /* We only process the init as a sideeffect in a single
 666          * case.   This is when we process the INIT-ACK.   If we
 667          * fail during INIT processing (due to malloc problems),
 668          * just return the error and stop processing the stack.
 669          */
 670         if (!sctp_process_init(asoc, chunk, sctp_source(chunk), peer_init, gfp))
 671                 error = -ENOMEM;
 672         else
 673                 error = 0;
 674
 675         return error;
 676 }
 677
 678 /* Helper function to break out starting up of heartbeat timers.  */
 679 static void sctp_cmd_hb_timers_start(struct sctp_cmd_seq *cmds,
 680                                      struct sctp_association *asoc)
 681 {
 682         struct sctp_transport *t;
 683
 684         /* Start a heartbeat timer for each transport on the association.
 685          * hold a reference on the transport to make sure none of
 686          * the needed data structures go away.
 687          */
 688         list_for_each_entry(t, &asoc->peer.transport_addr_list, transports)
 689                 sctp_transport_reset_hb_timer(t);
 690 }
 691
 692 static void sctp_cmd_hb_timers_stop(struct sctp_cmd_seq *cmds,
 693                                     struct sctp_association *asoc)
 694 {
 695         struct sctp_transport *t;
 696
 697         /* Stop all heartbeat timers. */
 698
 699         list_for_each_entry(t, &asoc->peer.transport_addr_list,
 700                         transports) {
 701                 if (del_timer(&t->hb_timer))
 702                         sctp_transport_put(t);
 703         }
 704 }
 705
 706 /* Helper function to stop any pending T3-RTX timers */
 707 static void sctp_cmd_t3_rtx_timers_stop(struct sctp_cmd_seq *cmds,
 708                                         struct sctp_association *asoc)
 709 {
 710         struct sctp_transport *t;
 711
 712         list_for_each_entry(t, &asoc->peer.transport_addr_list,
 713                         transports) {
 714                 if (del_timer(&t->T3_rtx_timer))
 715                         sctp_transport_put(t);
 716         }
 717 }
 718
 719
 720 /* Helper function to handle the reception of an HEARTBEAT ACK.  */
 721 static void sctp_cmd_transport_on(struct sctp_cmd_seq *cmds,
 722                                   struct sctp_association *asoc,
 723                                   struct sctp_transport *t,
 724                                   struct sctp_chunk *chunk)
 725 {
 726         struct sctp_sender_hb_info *hbinfo;
 727         int was_unconfirmed = 0;
 728
 729         /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
 730          * HEARTBEAT should clear the error counter of the destination
 731          * transport address to which the HEARTBEAT was sent.
 732          */
 733         t->error_count = 0;
 734
 735         /*
 736          * Although RFC4960 specifies that the overall error count must
 737          * be cleared when a HEARTBEAT ACK is received, we make an
 738          * exception while in SHUTDOWN PENDING. If the peer keeps its
 739          * window shut forever, we may never be able to transmit our
 740          * outstanding data and rely on the retransmission limit be reached
 741          * to shutdown the association.
 742          */
 743         if (t->asoc->state < SCTP_STATE_SHUTDOWN_PENDING)
 744                 t->asoc->overall_error_count = 0;
 745
 746         /* Clear the hb_sent flag to signal that we had a good
 747          * acknowledgement.
 748          */
 749         t->hb_sent = 0;
 750
 751         /* Mark the destination transport address as active if it is not so
 752          * marked.
 753          */
 754         if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED)) {
 755                 was_unconfirmed = 1;
 756                 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
 757                                              SCTP_HEARTBEAT_SUCCESS);
 758         }
 759
 760         if (t->state == SCTP_PF)
 761                 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
 762                                              SCTP_HEARTBEAT_SUCCESS);
 763
 764         /* HB-ACK was received for a the proper HB.  Consider this
 765          * forward progress.
 766          */
 767         if (t->dst)
 768                 sctp_transport_dst_confirm(t);
 769
 770         /* The receiver of the HEARTBEAT ACK should also perform an
 771          * RTT measurement for that destination transport address
 772          * using the time value carried in the HEARTBEAT ACK chunk.
 773          * If the transport's rto_pending variable has been cleared,
 774          * it was most likely due to a retransmit.  However, we want
 775          * to re-enable it to properly update the rto.
 776          */
 777         if (t->rto_pending == 0)
 778                 t->rto_pending = 1;
 779
 780         hbinfo = (struct sctp_sender_hb_info *)chunk->skb->data;
 781         sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
 782
 783         /* Update the heartbeat timer.  */
 784         sctp_transport_reset_hb_timer(t);
 785
 786         if (was_unconfirmed && asoc->peer.transport_count == 1)
 787                 sctp_transport_immediate_rtx(t);
 788 }
 789
 790
 791 /* Helper function to process the process SACK command.  */
 792 static int sctp_cmd_process_sack(struct sctp_cmd_seq *cmds,
 793                                  struct sctp_association *asoc,
 794                                  struct sctp_chunk *chunk)
 795 {
 796         int err = 0;
 797
 798         if (sctp_outq_sack(&asoc->outqueue, chunk)) {
 799                 /* There are no more TSNs awaiting SACK.  */
 800                 err = sctp_do_sm(asoc->base.net, SCTP_EVENT_T_OTHER,
 801                                  SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
 802                                  asoc->state, asoc->ep, asoc, NULL,
 803                                  GFP_ATOMIC);
 804         }
 805
 806         return err;
 807 }
 808
 809 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
 810  * the transport for a shutdown chunk.
 811  */
 812 static void sctp_cmd_setup_t2(struct sctp_cmd_seq *cmds,
 813                               struct sctp_association *asoc,
 814                               struct sctp_chunk *chunk)
 815 {
 816         struct sctp_transport *t;
 817
 818         if (chunk->transport)
 819                 t = chunk->transport;
 820         else {
 821                 t = sctp_assoc_choose_alter_transport(asoc,
 822                                               asoc->shutdown_last_sent_to);
 823                 chunk->transport = t;
 824         }
 825         asoc->shutdown_last_sent_to = t;
 826         asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
 827 }
 828
 829 static void sctp_cmd_assoc_update(struct sctp_cmd_seq *cmds,
 830                                   struct sctp_association *asoc,
 831                                   struct sctp_association *new)
 832 {
 833         struct net *net = asoc->base.net;
 834         struct sctp_chunk *abort;
 835
 836         if (!sctp_assoc_update(asoc, new))
 837                 return;
 838
 839         abort = sctp_make_abort(asoc, NULL, sizeof(struct sctp_errhdr));
 840         if (abort) {
 841                 sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0);
 842                 sctp_add_cmd_sf(cmds, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
 843         }
 844         sctp_add_cmd_sf(cmds, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNABORTED));
 845         sctp_add_cmd_sf(cmds, SCTP_CMD_ASSOC_FAILED,
 846                         SCTP_PERR(SCTP_ERROR_RSRC_LOW));
 847         SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
 848         SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
 849 }
 850
 851 /* Helper function to change the state of an association. */
 852 static void sctp_cmd_new_state(struct sctp_cmd_seq *cmds,
 853                                struct sctp_association *asoc,
 854                                enum sctp_state state)
 855 {
 856         struct sock *sk = asoc->base.sk;
 857
 858         asoc->state = state;
 859
 860         pr_debug("%s: asoc:%p[%s]\n", __func__, asoc, sctp_state_tbl[state]);
 861
 862         if (sctp_style(sk, TCP)) {
 863                 /* Change the sk->sk_state of a TCP-style socket that has
 864                  * successfully completed a connect() call.
 865                  */
 866                 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
 867                         inet_sk_set_state(sk, SCTP_SS_ESTABLISHED);
 868
 869                 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
 870                 if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
 871                     sctp_sstate(sk, ESTABLISHED)) {
 872                         inet_sk_set_state(sk, SCTP_SS_CLOSING);
 873                         sk->sk_shutdown |= RCV_SHUTDOWN;
 874                 }
 875         }
 876
 877         if (sctp_state(asoc, COOKIE_WAIT)) {
 878                 /* Reset init timeouts since they may have been
 879                  * increased due to timer expirations.
 880                  */
 881                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
 882                                                 asoc->rto_initial;
 883                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
 884                                                 asoc->rto_initial;
 885         }
 886
 887         if (sctp_state(asoc, ESTABLISHED)) {
 888                 kfree(asoc->peer.cookie);
 889                 asoc->peer.cookie = NULL;
 890         }
 891
 892         if (sctp_state(asoc, ESTABLISHED) ||
 893             sctp_state(asoc, CLOSED) ||
 894             sctp_state(asoc, SHUTDOWN_RECEIVED)) {
 895                 /* Wake up any processes waiting in the asoc's wait queue in
 896                  * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
 897                  */
 898                 if (waitqueue_active(&asoc->wait))
 899                         wake_up_interruptible(&asoc->wait);
 900
 901                 /* Wake up any processes waiting in the sk's sleep queue of
 902                  * a TCP-style or UDP-style peeled-off socket in
 903                  * sctp_wait_for_accept() or sctp_wait_for_packet().
 904                  * For a UDP-style socket, the waiters are woken up by the
 905                  * notifications.
 906                  */
 907                 if (!sctp_style(sk, UDP))
 908                         sk->sk_state_change(sk);
 909         }
 910
 911         if (sctp_state(asoc, SHUTDOWN_PENDING) &&
 912             !sctp_outq_is_empty(&asoc->outqueue))
 913                 sctp_outq_uncork(&asoc->outqueue, GFP_ATOMIC);
 914 }
 915
 916 /* Helper function to delete an association. */
 917 static void sctp_cmd_delete_tcb(struct sctp_cmd_seq *cmds,
 918                                 struct sctp_association *asoc)
 919 {
 920         struct sock *sk = asoc->base.sk;
 921
 922         /* If it is a non-temporary association belonging to a TCP-style
 923          * listening socket that is not closed, do not free it so that accept()
 924          * can pick it up later.
 925          */
 926         if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
 927             (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
 928                 return;
 929
 930         sctp_association_free(asoc);
 931 }
 932
 933 /*
 934  * ADDIP Section 4.1 ASCONF Chunk Procedures
 935  * A4) Start a T-4 RTO timer, using the RTO value of the selected
 936  * destination address (we use active path instead of primary path just
 937  * because primary path may be inactive.
 938  */
 939 static void sctp_cmd_setup_t4(struct sctp_cmd_seq *cmds,
 940                               struct sctp_association *asoc,
 941                               struct sctp_chunk *chunk)
 942 {
 943         struct sctp_transport *t;
 944
 945         t = sctp_assoc_choose_alter_transport(asoc, chunk->transport);
 946         asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
 947         chunk->transport = t;
 948 }
 949
 950 /* Process an incoming Operation Error Chunk. */
 951 static void sctp_cmd_process_operr(struct sctp_cmd_seq *cmds,
 952                                    struct sctp_association *asoc,
 953                                    struct sctp_chunk *chunk)
 954 {
 955         struct sctp_errhdr *err_hdr;
 956         struct sctp_ulpevent *ev;
 957
 958         while (chunk->chunk_end > chunk->skb->data) {
 959                 err_hdr = (struct sctp_errhdr *)(chunk->skb->data);
 960
 961                 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
 962                                                      GFP_ATOMIC);
 963                 if (!ev)
 964                         return;
 965
 966                 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
 967
 968                 switch (err_hdr->cause) {
 969                 case SCTP_ERROR_UNKNOWN_CHUNK:
 970                 {
 971                         struct sctp_chunkhdr *unk_chunk_hdr;
 972
 973                         unk_chunk_hdr = (struct sctp_chunkhdr *)
 974                                                         err_hdr->variable;
 975                         switch (unk_chunk_hdr->type) {
 976                         /* ADDIP 4.1 A9) If the peer responds to an ASCONF with
 977                          * an ERROR chunk reporting that it did not recognized
 978                          * the ASCONF chunk type, the sender of the ASCONF MUST
 979                          * NOT send any further ASCONF chunks and MUST stop its
 980                          * T-4 timer.
 981                          */
 982                         case SCTP_CID_ASCONF:
 983                                 if (asoc->peer.asconf_capable == 0)
 984                                         break;
 985
 986                                 asoc->peer.asconf_capable = 0;
 987                                 sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
 988                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
 989                                 break;
 990                         default:
 991                                 break;
 992                         }
 993                         break;
 994                 }
 995                 default:
 996                         break;
 997                 }
 998         }
 999 }
1000
1001 /* Helper function to remove the association non-primary peer
1002  * transports.
1003  */
1004 static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
1005 {
1006         struct sctp_transport *t;
1007         struct list_head *temp;
1008         struct list_head *pos;
1009
1010         list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
1011                 t = list_entry(pos, struct sctp_transport, transports);
1012                 if (!sctp_cmp_addr_exact(&t->ipaddr,
1013                                          &asoc->peer.primary_addr)) {
1014                         sctp_assoc_rm_peer(asoc, t);
1015                 }
1016         }
1017 }
1018
1019 /* Helper function to set sk_err on a 1-1 style socket. */
1020 static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
1021 {
1022         struct sock *sk = asoc->base.sk;
1023
1024         if (!sctp_style(sk, UDP))
1025                 sk->sk_err = error;
1026 }
1027
1028 /* Helper function to generate an association change event */
1029 static void sctp_cmd_assoc_change(struct sctp_cmd_seq *commands,
1030                                   struct sctp_association *asoc,
1031                                   u8 state)
1032 {
1033         struct sctp_ulpevent *ev;
1034
1035         ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0,
1036                                             asoc->c.sinit_num_ostreams,
1037                                             asoc->c.sinit_max_instreams,
1038                                             NULL, GFP_ATOMIC);
1039         if (ev)
1040                 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
1041 }
1042
1043 static void sctp_cmd_peer_no_auth(struct sctp_cmd_seq *commands,
1044                                   struct sctp_association *asoc)
1045 {
1046         struct sctp_ulpevent *ev;
1047
1048         ev = sctp_ulpevent_make_authkey(asoc, 0, SCTP_AUTH_NO_AUTH, GFP_ATOMIC);
1049         if (ev)
1050                 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
1051 }
1052
1053 /* Helper function to generate an adaptation indication event */
1054 static void sctp_cmd_adaptation_ind(struct sctp_cmd_seq *commands,
1055                                     struct sctp_association *asoc)
1056 {
1057         struct sctp_ulpevent *ev;
1058
1059         ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
1060
1061         if (ev)
1062                 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
1063 }
1064
1065
1066 static void sctp_cmd_t1_timer_update(struct sctp_association *asoc,
1067                                      enum sctp_event_timeout timer,
1068                                      char *name)
1069 {
1070         struct sctp_transport *t;
1071
1072         t = asoc->init_last_sent_to;
1073         asoc->init_err_counter++;
1074
1075         if (t->init_sent_count > (asoc->init_cycle + 1)) {
1076                 asoc->timeouts[timer] *= 2;
1077                 if (asoc->timeouts[timer] > asoc->max_init_timeo) {
1078                         asoc->timeouts[timer] = asoc->max_init_timeo;
1079                 }
1080                 asoc->init_cycle++;
1081
1082                 pr_debug("%s: T1[%s] timeout adjustment init_err_counter:%d"
1083                          " cycle:%d timeout:%ld\n", __func__, name,
1084                          asoc->init_err_counter, asoc->init_cycle,
1085                          asoc->timeouts[timer]);
1086         }
1087
1088 }
1089
1090 /* Send the whole message, chunk by chunk, to the outqueue.
1091  * This way the whole message is queued up and bundling if
1092  * encouraged for small fragments.
1093  */
1094 static void sctp_cmd_send_msg(struct sctp_association *asoc,
1095                               struct sctp_datamsg *msg, gfp_t gfp)
1096 {
1097         struct sctp_chunk *chunk;
1098
1099         list_for_each_entry(chunk, &msg->chunks, frag_list)
1100                 sctp_outq_tail(&asoc->outqueue, chunk, gfp);
1101
1102         asoc->outqueue.sched->enqueue(&asoc->outqueue, msg);
1103 }
1104
1105
1106 /* These three macros allow us to pull the debugging code out of the
1107  * main flow of sctp_do_sm() to keep attention focused on the real
1108  * functionality there.
1109  */
1110 #define debug_pre_sfn() \
1111         pr_debug("%s[pre-fn]: ep:%p, %s, %s, asoc:%p[%s], %s\n", __func__, \
1112                  ep, sctp_evttype_tbl[event_type], (*debug_fn)(subtype),   \
1113                  asoc, sctp_state_tbl[state], state_fn->name)
1114
1115 #define debug_post_sfn() \
1116         pr_debug("%s[post-fn]: asoc:%p, status:%s\n", __func__, asoc, \
1117                  sctp_status_tbl[status])
1118
1119 #define debug_post_sfx() \
1120         pr_debug("%s[post-sfx]: error:%d, asoc:%p[%s]\n", __func__, error, \
1121                  asoc, sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
1122                  sctp_assoc2id(asoc))) ? asoc->state : SCTP_STATE_CLOSED])
1123
1124 /*
1125  * This is the master state machine processing function.
1126  *
1127  * If you want to understand all of lksctp, this is a
1128  * good place to start.
1129  */
1130 int sctp_do_sm(struct net *net, enum sctp_event_type event_type,
1131                union sctp_subtype subtype, enum sctp_state state,
1132                struct sctp_endpoint *ep, struct sctp_association *asoc,
1133                void *event_arg, gfp_t gfp)
1134 {
1135         typedef const char *(printfn_t)(union sctp_subtype);
1136         static printfn_t *table[] = {
1137                 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
1138         };
1139         printfn_t *debug_fn  __attribute__ ((unused)) = table[event_type];
1140         const struct sctp_sm_table_entry *state_fn;
1141         struct sctp_cmd_seq commands;
1142         enum sctp_disposition status;
1143         int error = 0;
1144
1145         /* Look up the state function, run it, and then process the
1146          * side effects.  These three steps are the heart of lksctp.
1147          */
1148         state_fn = sctp_sm_lookup_event(net, event_type, state, subtype);
1149
1150         sctp_init_cmd_seq(&commands);
1151
1152         debug_pre_sfn();
1153         status = state_fn->fn(net, ep, asoc, subtype, event_arg, &commands);
1154         debug_post_sfn();
1155
1156         error = sctp_side_effects(event_type, subtype, state,
1157                                   ep, &asoc, event_arg, status,
1158                                   &commands, gfp);
1159         debug_post_sfx();
1160
1161         return error;
1162 }
1163
1164 /*****************************************************************
1165  * This the master state function side effect processing function.
1166  *****************************************************************/
1167 static int sctp_side_effects(enum sctp_event_type event_type,
1168                              union sctp_subtype subtype,
1169                              enum sctp_state state,
1170                              struct sctp_endpoint *ep,
1171                              struct sctp_association **asoc,
1172                              void *event_arg,
1173                              enum sctp_disposition status,
1174                              struct sctp_cmd_seq *commands,
1175                              gfp_t gfp)
1176 {
1177         int error;
1178
1179         /* FIXME - Most of the dispositions left today would be categorized
1180          * as "exceptional" dispositions.  For those dispositions, it
1181          * may not be proper to run through any of the commands at all.
1182          * For example, the command interpreter might be run only with
1183          * disposition SCTP_DISPOSITION_CONSUME.
1184          */
1185         if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
1186                                                ep, *asoc,
1187                                                event_arg, status,
1188                                                commands, gfp)))
1189                 goto bail;
1190
1191         switch (status) {
1192         case SCTP_DISPOSITION_DISCARD:
1193                 pr_debug("%s: ignored sctp protocol event - state:%d, "
1194                          "event_type:%d, event_id:%d\n", __func__, state,
1195                          event_type, subtype.chunk);
1196                 break;
1197
1198         case SCTP_DISPOSITION_NOMEM:
1199                 /* We ran out of memory, so we need to discard this
1200                  * packet.
1201                  */
1202                 /* BUG--we should now recover some memory, probably by
1203                  * reneging...
1204                  */
1205                 error = -ENOMEM;
1206                 break;
1207
1208         case SCTP_DISPOSITION_DELETE_TCB:
1209         case SCTP_DISPOSITION_ABORT:
1210                 /* This should now be a command. */
1211                 *asoc = NULL;
1212                 break;
1213
1214         case SCTP_DISPOSITION_CONSUME:
1215                 /*
1216                  * We should no longer have much work to do here as the
1217                  * real work has been done as explicit commands above.
1218                  */
1219                 break;
1220
1221         case SCTP_DISPOSITION_VIOLATION:
1222                 net_err_ratelimited("protocol violation state %d chunkid %d\n",
1223                                     state, subtype.chunk);
1224                 break;
1225
1226         case SCTP_DISPOSITION_NOT_IMPL:
1227                 pr_warn("unimplemented feature in state %d, event_type %d, event_id %d\n",
1228                         state, event_type, subtype.chunk);
1229                 break;
1230
1231         case SCTP_DISPOSITION_BUG:
1232                 pr_err("bug in state %d, event_type %d, event_id %d\n",
1233                        state, event_type, subtype.chunk);
1234                 BUG();
1235                 break;
1236
1237         default:
1238                 pr_err("impossible disposition %d in state %d, event_type %d, event_id %d\n",
1239                        status, state, event_type, subtype.chunk);
1240                 BUG();
1241                 break;
1242         }
1243
1244 bail:
1245         return error;
1246 }
1247
1248 /********************************************************************
1249  * 2nd Level Abstractions
1250  ********************************************************************/
1251
1252 /* This is the side-effect interpreter.  */
1253 static int sctp_cmd_interpreter(enum sctp_event_type event_type,
1254                                 union sctp_subtype subtype,
1255                                 enum sctp_state state,
1256                                 struct sctp_endpoint *ep,
1257                                 struct sctp_association *asoc,
1258                                 void *event_arg,
1259                                 enum sctp_disposition status,
1260                                 struct sctp_cmd_seq *commands,
1261                                 gfp_t gfp)
1262 {
1263         struct sctp_sock *sp = sctp_sk(ep->base.sk);
1264         struct sctp_chunk *chunk = NULL, *new_obj;
1265         struct sctp_packet *packet;
1266         struct sctp_sackhdr sackh;
1267         struct timer_list *timer;
1268         struct sctp_transport *t;
1269         unsigned long timeout;
1270         struct sctp_cmd *cmd;
1271         int local_cork = 0;
1272         int error = 0;
1273         int force;
1274
1275         if (SCTP_EVENT_T_TIMEOUT != event_type)
1276                 chunk = event_arg;
1277
1278         /* Note:  This whole file is a huge candidate for rework.
1279          * For example, each command could either have its own handler, so
1280          * the loop would look like:
1281          *     while (cmds)
1282          *         cmd->handle(x, y, z)
1283          * --jgrimm
1284          */
1285         while (NULL != (cmd = sctp_next_cmd(commands))) {
1286                 switch (cmd->verb) {
1287                 case SCTP_CMD_NOP:
1288                         /* Do nothing. */
1289                         break;
1290
1291                 case SCTP_CMD_NEW_ASOC:
1292                         /* Register a new association.  */
1293                         if (local_cork) {
1294                                 sctp_outq_uncork(&asoc->outqueue, gfp);
1295                                 local_cork = 0;
1296                         }
1297
1298                         /* Register with the endpoint.  */
1299                         asoc = cmd->obj.asoc;
1300                         BUG_ON(asoc->peer.primary_path == NULL);
1301                         sctp_endpoint_add_asoc(ep, asoc);
1302                         break;
1303
1304                 case SCTP_CMD_UPDATE_ASSOC:
1305                        sctp_cmd_assoc_update(commands, asoc, cmd->obj.asoc);
1306                        break;
1307
1308                 case SCTP_CMD_PURGE_OUTQUEUE:
1309                        sctp_outq_teardown(&asoc->outqueue);
1310                        break;
1311
1312                 case SCTP_CMD_DELETE_TCB:
1313                         if (local_cork) {
1314                                 sctp_outq_uncork(&asoc->outqueue, gfp);
1315                                 local_cork = 0;
1316                         }
1317                         /* Delete the current association.  */
1318                         sctp_cmd_delete_tcb(commands, asoc);
1319                         asoc = NULL;
1320                         break;
1321
1322                 case SCTP_CMD_NEW_STATE:
1323                         /* Enter a new state.  */
1324                         sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1325                         break;
1326
1327                 case SCTP_CMD_REPORT_TSN:
1328                         /* Record the arrival of a TSN.  */
1329                         error = sctp_tsnmap_mark(&asoc->peer.tsn_map,
1330                                                  cmd->obj.u32, NULL);
1331                         break;
1332
1333                 case SCTP_CMD_REPORT_FWDTSN:
1334                         asoc->stream.si->report_ftsn(&asoc->ulpq, cmd->obj.u32);
1335                         break;
1336
1337                 case SCTP_CMD_PROCESS_FWDTSN:
1338                         asoc->stream.si->handle_ftsn(&asoc->ulpq,
1339                                                      cmd->obj.chunk);
1340                         break;
1341
1342                 case SCTP_CMD_GEN_SACK:
1343                         /* Generate a Selective ACK.
1344                          * The argument tells us whether to just count
1345                          * the packet and MAYBE generate a SACK, or
1346                          * force a SACK out.
1347                          */
1348                         force = cmd->obj.i32;
1349                         error = sctp_gen_sack(asoc, force, commands);
1350                         break;
1351
1352                 case SCTP_CMD_PROCESS_SACK:
1353                         /* Process an inbound SACK.  */
1354                         error = sctp_cmd_process_sack(commands, asoc,
1355                                                       cmd->obj.chunk);
1356                         break;
1357
1358                 case SCTP_CMD_GEN_INIT_ACK:
1359                         /* Generate an INIT ACK chunk.  */
1360                         new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1361                                                      0);
1362                         if (!new_obj) {
1363                                 error = -ENOMEM;
1364                                 break;
1365                         }
1366
1367                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1368                                         SCTP_CHUNK(new_obj));
1369                         break;
1370
1371                 case SCTP_CMD_PEER_INIT:
1372                         /* Process a unified INIT from the peer.
1373                          * Note: Only used during INIT-ACK processing.  If
1374                          * there is an error just return to the outter
1375                          * layer which will bail.
1376                          */
1377                         error = sctp_cmd_process_init(commands, asoc, chunk,
1378                                                       cmd->obj.init, gfp);
1379                         break;
1380
1381                 case SCTP_CMD_GEN_COOKIE_ECHO:
1382                         /* Generate a COOKIE ECHO chunk.  */
1383                         new_obj = sctp_make_cookie_echo(asoc, chunk);
1384                         if (!new_obj) {
1385                                 if (cmd->obj.chunk)
1386                                         sctp_chunk_free(cmd->obj.chunk);
1387                                 error = -ENOMEM;
1388                                 break;
1389                         }
1390                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1391                                         SCTP_CHUNK(new_obj));
1392
1393                         /* If there is an ERROR chunk to be sent along with
1394                          * the COOKIE_ECHO, send it, too.
1395                          */
1396                         if (cmd->obj.chunk)
1397                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1398                                                 SCTP_CHUNK(cmd->obj.chunk));
1399
1400                         if (new_obj->transport) {
1401                                 new_obj->transport->init_sent_count++;
1402                                 asoc->init_last_sent_to = new_obj->transport;
1403                         }
1404
1405                         /* FIXME - Eventually come up with a cleaner way to
1406                          * enabling COOKIE-ECHO + DATA bundling during
1407                          * multihoming stale cookie scenarios, the following
1408                          * command plays with asoc->peer.retran_path to
1409                          * avoid the problem of sending the COOKIE-ECHO and
1410                          * DATA in different paths, which could result
1411                          * in the association being ABORTed if the DATA chunk
1412                          * is processed first by the server.  Checking the
1413                          * init error counter simply causes this command
1414                          * to be executed only during failed attempts of
1415                          * association establishment.
1416                          */
1417                         if ((asoc->peer.retran_path !=
1418                              asoc->peer.primary_path) &&
1419                             (asoc->init_err_counter > 0)) {
1420                                 sctp_add_cmd_sf(commands,
1421                                                 SCTP_CMD_FORCE_PRIM_RETRAN,
1422                                                 SCTP_NULL());
1423                         }
1424
1425                         break;
1426
1427                 case SCTP_CMD_GEN_SHUTDOWN:
1428                         /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1429                          * Reset error counts.
1430                          */
1431                         asoc->overall_error_count = 0;
1432
1433                         /* Generate a SHUTDOWN chunk.  */
1434                         new_obj = sctp_make_shutdown(asoc, chunk);
1435                         if (!new_obj) {
1436                                 error = -ENOMEM;
1437                                 break;
1438                         }
1439                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1440                                         SCTP_CHUNK(new_obj));
1441                         break;
1442
1443                 case SCTP_CMD_CHUNK_ULP:
1444                         /* Send a chunk to the sockets layer.  */
1445                         pr_debug("%s: sm_sideff: chunk_up:%p, ulpq:%p\n",
1446                                  __func__, cmd->obj.chunk, &asoc->ulpq);
1447
1448                         asoc->stream.si->ulpevent_data(&asoc->ulpq,
1449                                                        cmd->obj.chunk,
1450                                                        GFP_ATOMIC);
1451                         break;
1452
1453                 case SCTP_CMD_EVENT_ULP:
1454                         /* Send a notification to the sockets layer.  */
1455                         pr_debug("%s: sm_sideff: event_up:%p, ulpq:%p\n",
1456                                  __func__, cmd->obj.ulpevent, &asoc->ulpq);
1457
1458                         asoc->stream.si->enqueue_event(&asoc->ulpq,
1459                                                        cmd->obj.ulpevent);
1460                         break;
1461
1462                 case SCTP_CMD_REPLY:
1463                         /* If an caller has not already corked, do cork. */
1464                         if (!asoc->outqueue.cork) {
1465                                 sctp_outq_cork(&asoc->outqueue);
1466                                 local_cork = 1;
1467                         }
1468                         /* Send a chunk to our peer.  */
1469                         sctp_outq_tail(&asoc->outqueue, cmd->obj.chunk, gfp);
1470                         break;
1471
1472                 case SCTP_CMD_SEND_PKT:
1473                         /* Send a full packet to our peer.  */
1474                         packet = cmd->obj.packet;
1475                         sctp_packet_transmit(packet, gfp);
1476                         sctp_ootb_pkt_free(packet);
1477                         break;
1478
1479                 case SCTP_CMD_T1_RETRAN:
1480                         /* Mark a transport for retransmission.  */
1481                         sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1482                                         SCTP_RTXR_T1_RTX);
1483                         break;
1484
1485                 case SCTP_CMD_RETRAN:
1486                         /* Mark a transport for retransmission.  */
1487                         sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1488                                         SCTP_RTXR_T3_RTX);
1489                         break;
1490
1491                 case SCTP_CMD_ECN_CE:
1492                         /* Do delayed CE processing.   */
1493                         sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1494                         break;
1495
1496                 case SCTP_CMD_ECN_ECNE:
1497                         /* Do delayed ECNE processing. */
1498                         new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1499                                                         chunk);
1500                         if (new_obj)
1501                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1502                                                 SCTP_CHUNK(new_obj));
1503                         break;
1504
1505                 case SCTP_CMD_ECN_CWR:
1506                         /* Do delayed CWR processing.  */
1507                         sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1508                         break;
1509
1510                 case SCTP_CMD_SETUP_T2:
1511                         sctp_cmd_setup_t2(commands, asoc, cmd->obj.chunk);
1512                         break;
1513
1514                 case SCTP_CMD_TIMER_START_ONCE:
1515                         timer = &asoc->timers[cmd->obj.to];
1516
1517                         if (timer_pending(timer))
1518                                 break;
1519                         fallthrough;
1520
1521                 case SCTP_CMD_TIMER_START:
1522                         timer = &asoc->timers[cmd->obj.to];
1523                         timeout = asoc->timeouts[cmd->obj.to];
1524                         BUG_ON(!timeout);
1525
1526                         /*
1527                          * SCTP has a hard time with timer starts.  Because we process
1528                          * timer starts as side effects, it can be hard to tell if we
1529                          * have already started a timer or not, which leads to BUG
1530                          * halts when we call add_timer. So here, instead of just starting
1531                          * a timer, if the timer is already started, and just mod
1532                          * the timer with the shorter of the two expiration times
1533                          */
1534                         if (!timer_pending(timer))
1535                                 sctp_association_hold(asoc);
1536                         timer_reduce(timer, jiffies + timeout);
1537                         break;
1538
1539                 case SCTP_CMD_TIMER_RESTART:
1540                         timer = &asoc->timers[cmd->obj.to];
1541                         timeout = asoc->timeouts[cmd->obj.to];
1542                         if (!mod_timer(timer, jiffies + timeout))
1543                                 sctp_association_hold(asoc);
1544                         break;
1545
1546                 case SCTP_CMD_TIMER_STOP:
1547                         timer = &asoc->timers[cmd->obj.to];
1548                         if (del_timer(timer))
1549                                 sctp_association_put(asoc);
1550                         break;
1551
1552                 case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1553                         chunk = cmd->obj.chunk;
1554                         t = sctp_assoc_choose_alter_transport(asoc,
1555                                                 asoc->init_last_sent_to);
1556                         asoc->init_last_sent_to = t;
1557                         chunk->transport = t;
1558                         t->init_sent_count++;
1559                         /* Set the new transport as primary */
1560                         sctp_assoc_set_primary(asoc, t);
1561                         break;
1562
1563                 case SCTP_CMD_INIT_RESTART:
1564                         /* Do the needed accounting and updates
1565                          * associated with restarting an initialization
1566                          * timer. Only multiply the timeout by two if
1567                          * all transports have been tried at the current
1568                          * timeout.
1569                          */
1570                         sctp_cmd_t1_timer_update(asoc,
1571                                                 SCTP_EVENT_TIMEOUT_T1_INIT,
1572                                                 "INIT");
1573
1574                         sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1575                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1576                         break;
1577
1578                 case SCTP_CMD_COOKIEECHO_RESTART:
1579                         /* Do the needed accounting and updates
1580                          * associated with restarting an initialization
1581                          * timer. Only multiply the timeout by two if
1582                          * all transports have been tried at the current
1583                          * timeout.
1584                          */
1585                         sctp_cmd_t1_timer_update(asoc,
1586                                                 SCTP_EVENT_TIMEOUT_T1_COOKIE,
1587                                                 "COOKIE");
1588
1589                         /* If we've sent any data bundled with
1590                          * COOKIE-ECHO we need to resend.
1591                          */
1592                         list_for_each_entry(t, &asoc->peer.transport_addr_list,
1593                                         transports) {
1594                                 sctp_retransmit_mark(&asoc->outqueue, t,
1595                                             SCTP_RTXR_T1_RTX);
1596                         }
1597
1598                         sctp_add_cmd_sf(commands,
1599                                         SCTP_CMD_TIMER_RESTART,
1600                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1601                         break;
1602
1603                 case SCTP_CMD_INIT_FAILED:
1604                         sctp_cmd_init_failed(commands, asoc, cmd->obj.u16);
1605                         break;
1606
1607                 case SCTP_CMD_ASSOC_FAILED:
1608                         sctp_cmd_assoc_failed(commands, asoc, event_type,
1609                                               subtype, chunk, cmd->obj.u16);
1610                         break;
1611
1612                 case SCTP_CMD_INIT_COUNTER_INC:
1613                         asoc->init_err_counter++;
1614                         break;
1615
1616                 case SCTP_CMD_INIT_COUNTER_RESET:
1617                         asoc->init_err_counter = 0;
1618                         asoc->init_cycle = 0;
1619                         list_for_each_entry(t, &asoc->peer.transport_addr_list,
1620                                             transports) {
1621                                 t->init_sent_count = 0;
1622                         }
1623                         break;
1624
1625                 case SCTP_CMD_REPORT_DUP:
1626                         sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1627                                              cmd->obj.u32);
1628                         break;
1629
1630                 case SCTP_CMD_REPORT_BAD_TAG:
1631                         pr_debug("%s: vtag mismatch!\n", __func__);
1632                         break;
1633
1634                 case SCTP_CMD_STRIKE:
1635                         /* Mark one strike against a transport.  */
1636                         sctp_do_8_2_transport_strike(commands, asoc,
1637                                                     cmd->obj.transport, 0);
1638                         break;
1639
1640                 case SCTP_CMD_TRANSPORT_IDLE:
1641                         t = cmd->obj.transport;
1642                         sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
1643                         break;
1644
1645                 case SCTP_CMD_TRANSPORT_HB_SENT:
1646                         t = cmd->obj.transport;
1647                         sctp_do_8_2_transport_strike(commands, asoc,
1648                                                      t, 1);
1649                         t->hb_sent = 1;
1650                         break;
1651
1652                 case SCTP_CMD_TRANSPORT_ON:
1653                         t = cmd->obj.transport;
1654                         sctp_cmd_transport_on(commands, asoc, t, chunk);
1655                         break;
1656
1657                 case SCTP_CMD_HB_TIMERS_START:
1658                         sctp_cmd_hb_timers_start(commands, asoc);
1659                         break;
1660
1661                 case SCTP_CMD_HB_TIMER_UPDATE:
1662                         t = cmd->obj.transport;
1663                         sctp_transport_reset_hb_timer(t);
1664                         break;
1665
1666                 case SCTP_CMD_HB_TIMERS_STOP:
1667                         sctp_cmd_hb_timers_stop(commands, asoc);
1668                         break;
1669
1670                 case SCTP_CMD_REPORT_ERROR:
1671                         error = cmd->obj.error;
1672                         break;
1673
1674                 case SCTP_CMD_PROCESS_CTSN:
1675                         /* Dummy up a SACK for processing. */
1676                         sackh.cum_tsn_ack = cmd->obj.be32;
1677                         sackh.a_rwnd = htonl(asoc->peer.rwnd +
1678                                              asoc->outqueue.outstanding_bytes);
1679                         sackh.num_gap_ack_blocks = 0;
1680                         sackh.num_dup_tsns = 0;
1681                         chunk->subh.sack_hdr = &sackh;
1682                         sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1683                                         SCTP_CHUNK(chunk));
1684                         break;
1685
1686                 case SCTP_CMD_DISCARD_PACKET:
1687                         /* We need to discard the whole packet.
1688                          * Uncork the queue since there might be
1689                          * responses pending
1690                          */
1691                         chunk->pdiscard = 1;
1692                         if (asoc) {
1693                                 sctp_outq_uncork(&asoc->outqueue, gfp);
1694                                 local_cork = 0;
1695                         }
1696                         break;
1697
1698                 case SCTP_CMD_RTO_PENDING:
1699                         t = cmd->obj.transport;
1700                         t->rto_pending = 1;
1701                         break;
1702
1703                 case SCTP_CMD_PART_DELIVER:
1704                         asoc->stream.si->start_pd(&asoc->ulpq, GFP_ATOMIC);
1705                         break;
1706
1707                 case SCTP_CMD_RENEGE:
1708                         asoc->stream.si->renege_events(&asoc->ulpq,
1709                                                        cmd->obj.chunk,
1710                                                        GFP_ATOMIC);
1711                         break;
1712
1713                 case SCTP_CMD_SETUP_T4:
1714                         sctp_cmd_setup_t4(commands, asoc, cmd->obj.chunk);
1715                         break;
1716
1717                 case SCTP_CMD_PROCESS_OPERR:
1718                         sctp_cmd_process_operr(commands, asoc, chunk);
1719                         break;
1720                 case SCTP_CMD_CLEAR_INIT_TAG:
1721                         asoc->peer.i.init_tag = 0;
1722                         break;
1723                 case SCTP_CMD_DEL_NON_PRIMARY:
1724                         sctp_cmd_del_non_primary(asoc);
1725                         break;
1726                 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1727                         sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1728                         break;
1729                 case SCTP_CMD_FORCE_PRIM_RETRAN:
1730                         t = asoc->peer.retran_path;
1731                         asoc->peer.retran_path = asoc->peer.primary_path;
1732                         sctp_outq_uncork(&asoc->outqueue, gfp);
1733                         local_cork = 0;
1734                         asoc->peer.retran_path = t;
1735                         break;
1736                 case SCTP_CMD_SET_SK_ERR:
1737                         sctp_cmd_set_sk_err(asoc, cmd->obj.error);
1738                         break;
1739                 case SCTP_CMD_ASSOC_CHANGE:
1740                         sctp_cmd_assoc_change(commands, asoc,
1741                                               cmd->obj.u8);
1742                         break;
1743                 case SCTP_CMD_ADAPTATION_IND:
1744                         sctp_cmd_adaptation_ind(commands, asoc);
1745                         break;
1746                 case SCTP_CMD_PEER_NO_AUTH:
1747                         sctp_cmd_peer_no_auth(commands, asoc);
1748                         break;
1749
1750                 case SCTP_CMD_ASSOC_SHKEY:
1751                         error = sctp_auth_asoc_init_active_key(asoc,
1752                                                 GFP_ATOMIC);
1753                         break;
1754                 case SCTP_CMD_UPDATE_INITTAG:
1755                         asoc->peer.i.init_tag = cmd->obj.u32;
1756                         break;
1757                 case SCTP_CMD_SEND_MSG:
1758                         if (!asoc->outqueue.cork) {
1759                                 sctp_outq_cork(&asoc->outqueue);
1760                                 local_cork = 1;
1761                         }
1762                         sctp_cmd_send_msg(asoc, cmd->obj.msg, gfp);
1763                         break;
1764                 case SCTP_CMD_PURGE_ASCONF_QUEUE:
1765                         sctp_asconf_queue_teardown(asoc);
1766                         break;
1767
1768                 case SCTP_CMD_SET_ASOC:
1769                         if (asoc && local_cork) {
1770                                 sctp_outq_uncork(&asoc->outqueue, gfp);
1771                                 local_cork = 0;
1772                         }
1773                         asoc = cmd->obj.asoc;
1774                         break;
1775
1776                 default:
1777                         pr_warn("Impossible command: %u\n",
1778                                 cmd->verb);
1779                         break;
1780                 }
1781
1782                 if (error) {
1783                         cmd = sctp_next_cmd(commands);
1784                         while (cmd) {
1785                                 if (cmd->verb == SCTP_CMD_REPLY)
1786                                         sctp_chunk_free(cmd->obj.chunk);
1787                                 cmd = sctp_next_cmd(commands);
1788                         }
1789                         break;
1790                 }
1791         }
1792
1793         /* If this is in response to a received chunk, wait until
1794          * we are done with the packet to open the queue so that we don't
1795          * send multiple packets in response to a single request.
1796          */
1797         if (asoc && SCTP_EVENT_T_CHUNK == event_type && chunk) {
1798                 if (chunk->end_of_packet || chunk->singleton)
1799                         sctp_outq_uncork(&asoc->outqueue, gfp);
1800         } else if (local_cork)
1801                 sctp_outq_uncork(&asoc->outqueue, gfp);
1802
1803         if (sp->data_ready_signalled)
1804                 sp->data_ready_signalled = 0;
1805
1806         return error;
1807 }