net/sctp/sm_sideeffect.c

   1 /* SCTP kernel implementation
   2  * (C) Copyright IBM Corp. 2001, 2004
   3  * Copyright (c) 1999 Cisco, Inc.
   4  * Copyright (c) 1999-2001 Motorola, Inc.
   5  *
   6  * This file is part of the SCTP kernel implementation
   7  *
   8  * These functions work with the state functions in sctp_sm_statefuns.c
   9  * to implement that state operations.  These functions implement the
  10  * steps which require modifying existing data structures.
  11  *
  12  * This SCTP implementation is free software;
  13  * you can redistribute it and/or modify it under the terms of
  14  * the GNU General Public License as published by
  15  * the Free Software Foundation; either version 2, or (at your option)
  16  * any later version.
  17  *
  18  * This SCTP implementation is distributed in the hope that it
  19  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
  20  *                 ************************
  21  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  22  * See the GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with GNU CC; see the file COPYING.  If not, see
  26  * <http://www.gnu.org/licenses/>.
  27  *
  28  * Please send any bug reports or fixes you make to the
  29  * email address(es):
  30  *    lksctp developers <linux-sctp@vger.kernel.org>
  31  *
  32  * Written or modified by:
  33  *    La Monte H.P. Yarroll <piggy@acm.org>
  34  *    Karl Knutson          <karl@athena.chicago.il.us>
  35  *    Jon Grimm             <jgrimm@austin.ibm.com>
  36  *    Hui Huang             <hui.huang@nokia.com>
  37  *    Dajiang Zhang         <dajiang.zhang@nokia.com>
  38  *    Daisy Chang           <daisyc@us.ibm.com>
  39  *    Sridhar Samudrala     <sri@us.ibm.com>
  40  *    Ardelle Fan           <ardelle.fan@intel.com>
  41  */
  42
  43 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  44
  45 #include <linux/skbuff.h>
  46 #include <linux/types.h>
  47 #include <linux/socket.h>
  48 #include <linux/ip.h>
  49 #include <linux/gfp.h>
  50 #include <net/sock.h>
  51 #include <net/sctp/sctp.h>
  52 #include <net/sctp/sm.h>
  53 #include <net/sctp/stream_sched.h>
  54
  55 static int sctp_cmd_interpreter(enum sctp_event event_type,
  56                                 union sctp_subtype subtype,
  57                                 enum sctp_state state,
  58                                 struct sctp_endpoint *ep,
  59                                 struct sctp_association *asoc,
  60                                 void *event_arg,
  61                                 enum sctp_disposition status,
  62                                 struct sctp_cmd_seq *commands,
  63                                 gfp_t gfp);
  64 static int sctp_side_effects(enum sctp_event event_type,
  65                              union sctp_subtype subtype,
  66                              enum sctp_state state,
  67                              struct sctp_endpoint *ep,
  68                              struct sctp_association **asoc,
  69                              void *event_arg,
  70                              enum sctp_disposition status,
  71                              struct sctp_cmd_seq *commands,
  72                              gfp_t gfp);
  73
  74 /********************************************************************
  75  * Helper functions
  76  ********************************************************************/
  77
  78 /* A helper function for delayed processing of INET ECN CE bit. */
  79 static void sctp_do_ecn_ce_work(struct sctp_association *asoc,
  80                                 __u32 lowest_tsn)
  81 {
  82         /* Save the TSN away for comparison when we receive CWR */
  83
  84         asoc->last_ecne_tsn = lowest_tsn;
  85         asoc->need_ecne = 1;
  86 }
  87
  88 /* Helper function for delayed processing of SCTP ECNE chunk.  */
  89 /* RFC 2960 Appendix A
  90  *
  91  * RFC 2481 details a specific bit for a sender to send in
  92  * the header of its next outbound TCP segment to indicate to
  93  * its peer that it has reduced its congestion window.  This
  94  * is termed the CWR bit.  For SCTP the same indication is made
  95  * by including the CWR chunk.  This chunk contains one data
  96  * element, i.e. the TSN number that was sent in the ECNE chunk.
  97  * This element represents the lowest TSN number in the datagram
  98  * that was originally marked with the CE bit.
  99  */
 100 static struct sctp_chunk *sctp_do_ecn_ecne_work(struct sctp_association *asoc,
 101                                                 __u32 lowest_tsn,
 102                                                 struct sctp_chunk *chunk)
 103 {
 104         struct sctp_chunk *repl;
 105
 106         /* Our previously transmitted packet ran into some congestion
 107          * so we should take action by reducing cwnd and ssthresh
 108          * and then ACK our peer that we we've done so by
 109          * sending a CWR.
 110          */
 111
 112         /* First, try to determine if we want to actually lower
 113          * our cwnd variables.  Only lower them if the ECNE looks more
 114          * recent than the last response.
 115          */
 116         if (TSN_lt(asoc->last_cwr_tsn, lowest_tsn)) {
 117                 struct sctp_transport *transport;
 118
 119                 /* Find which transport's congestion variables
 120                  * need to be adjusted.
 121                  */
 122                 transport = sctp_assoc_lookup_tsn(asoc, lowest_tsn);
 123
 124                 /* Update the congestion variables. */
 125                 if (transport)
 126                         sctp_transport_lower_cwnd(transport,
 127                                                   SCTP_LOWER_CWND_ECNE);
 128                 asoc->last_cwr_tsn = lowest_tsn;
 129         }
 130
 131         /* Always try to quiet the other end.  In case of lost CWR,
 132          * resend last_cwr_tsn.
 133          */
 134         repl = sctp_make_cwr(asoc, asoc->last_cwr_tsn, chunk);
 135
 136         /* If we run out of memory, it will look like a lost CWR.  We'll
 137          * get back in sync eventually.
 138          */
 139         return repl;
 140 }
 141
 142 /* Helper function to do delayed processing of ECN CWR chunk.  */
 143 static void sctp_do_ecn_cwr_work(struct sctp_association *asoc,
 144                                  __u32 lowest_tsn)
 145 {
 146         /* Turn off ECNE getting auto-prepended to every outgoing
 147          * packet
 148          */
 149         asoc->need_ecne = 0;
 150 }
 151
 152 /* Generate SACK if necessary.  We call this at the end of a packet.  */
 153 static int sctp_gen_sack(struct sctp_association *asoc, int force,
 154                          struct sctp_cmd_seq *commands)
 155 {
 156         struct sctp_transport *trans = asoc->peer.last_data_from;
 157         __u32 ctsn, max_tsn_seen;
 158         struct sctp_chunk *sack;
 159         int error = 0;
 160
 161         if (force ||
 162             (!trans && (asoc->param_flags & SPP_SACKDELAY_DISABLE)) ||
 163             (trans && (trans->param_flags & SPP_SACKDELAY_DISABLE)))
 164                 asoc->peer.sack_needed = 1;
 165
 166         ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
 167         max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
 168
 169         /* From 12.2 Parameters necessary per association (i.e. the TCB):
 170          *
 171          * Ack State : This flag indicates if the next received packet
 172          *           : is to be responded to with a SACK. ...
 173          *           : When DATA chunks are out of order, SACK's
 174          *           : are not delayed (see Section 6).
 175          *
 176          * [This is actually not mentioned in Section 6, but we
 177          * implement it here anyway. --piggy]
 178          */
 179         if (max_tsn_seen != ctsn)
 180                 asoc->peer.sack_needed = 1;
 181
 182         /* From 6.2  Acknowledgement on Reception of DATA Chunks:
 183          *
 184          * Section 4.2 of [RFC2581] SHOULD be followed. Specifically,
 185          * an acknowledgement SHOULD be generated for at least every
 186          * second packet (not every second DATA chunk) received, and
 187          * SHOULD be generated within 200 ms of the arrival of any
 188          * unacknowledged DATA chunk. ...
 189          */
 190         if (!asoc->peer.sack_needed) {
 191                 asoc->peer.sack_cnt++;
 192
 193                 /* Set the SACK delay timeout based on the
 194                  * SACK delay for the last transport
 195                  * data was received from, or the default
 196                  * for the association.
 197                  */
 198                 if (trans) {
 199                         /* We will need a SACK for the next packet.  */
 200                         if (asoc->peer.sack_cnt >= trans->sackfreq - 1)
 201                                 asoc->peer.sack_needed = 1;
 202
 203                         asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
 204                                 trans->sackdelay;
 205                 } else {
 206                         /* We will need a SACK for the next packet.  */
 207                         if (asoc->peer.sack_cnt >= asoc->sackfreq - 1)
 208                                 asoc->peer.sack_needed = 1;
 209
 210                         asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
 211                                 asoc->sackdelay;
 212                 }
 213
 214                 /* Restart the SACK timer. */
 215                 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
 216                                 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
 217         } else {
 218                 __u32 old_a_rwnd = asoc->a_rwnd;
 219
 220                 asoc->a_rwnd = asoc->rwnd;
 221                 sack = sctp_make_sack(asoc);
 222                 if (!sack) {
 223                         asoc->a_rwnd = old_a_rwnd;
 224                         goto nomem;
 225                 }
 226
 227                 asoc->peer.sack_needed = 0;
 228                 asoc->peer.sack_cnt = 0;
 229
 230                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(sack));
 231
 232                 /* Stop the SACK timer.  */
 233                 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
 234                                 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
 235         }
 236
 237         return error;
 238 nomem:
 239         error = -ENOMEM;
 240         return error;
 241 }
 242
 243 /* When the T3-RTX timer expires, it calls this function to create the
 244  * relevant state machine event.
 245  */
 246 void sctp_generate_t3_rtx_event(struct timer_list *t)
 247 {
 248         struct sctp_transport *transport =
 249                 from_timer(transport, t, T3_rtx_timer);
 250         struct sctp_association *asoc = transport->asoc;
 251         struct sock *sk = asoc->base.sk;
 252         struct net *net = sock_net(sk);
 253         int error;
 254
 255         /* Check whether a task is in the sock.  */
 256
 257         bh_lock_sock(sk);
 258         if (sock_owned_by_user(sk)) {
 259                 pr_debug("%s: sock is busy\n", __func__);
 260
 261                 /* Try again later.  */
 262                 if (!mod_timer(&transport->T3_rtx_timer, jiffies + (HZ/20)))
 263                         sctp_transport_hold(transport);
 264                 goto out_unlock;
 265         }
 266
 267         /* Run through the state machine.  */
 268         error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
 269                            SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX),
 270                            asoc->state,
 271                            asoc->ep, asoc,
 272                            transport, GFP_ATOMIC);
 273
 274         if (error)
 275                 sk->sk_err = -error;
 276
 277 out_unlock:
 278         bh_unlock_sock(sk);
 279         sctp_transport_put(transport);
 280 }
 281
 282 /* This is a sa interface for producing timeout events.  It works
 283  * for timeouts which use the association as their parameter.
 284  */
 285 static void sctp_generate_timeout_event(struct sctp_association *asoc,
 286                                         enum sctp_event_timeout timeout_type)
 287 {
 288         struct sock *sk = asoc->base.sk;
 289         struct net *net = sock_net(sk);
 290         int error = 0;
 291
 292         bh_lock_sock(sk);
 293         if (sock_owned_by_user(sk)) {
 294                 pr_debug("%s: sock is busy: timer %d\n", __func__,
 295                          timeout_type);
 296
 297                 /* Try again later.  */
 298                 if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20)))
 299                         sctp_association_hold(asoc);
 300                 goto out_unlock;
 301         }
 302
 303         /* Is this association really dead and just waiting around for
 304          * the timer to let go of the reference?
 305          */
 306         if (asoc->base.dead)
 307                 goto out_unlock;
 308
 309         /* Run through the state machine.  */
 310         error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
 311                            SCTP_ST_TIMEOUT(timeout_type),
 312                            asoc->state, asoc->ep, asoc,
 313                            (void *)timeout_type, GFP_ATOMIC);
 314
 315         if (error)
 316                 sk->sk_err = -error;
 317
 318 out_unlock:
 319         bh_unlock_sock(sk);
 320         sctp_association_put(asoc);
 321 }
 322
 323 static void sctp_generate_t1_cookie_event(struct timer_list *t)
 324 {
 325         struct sctp_association *asoc =
 326                 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_T1_COOKIE]);
 327
 328         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
 329 }
 330
 331 static void sctp_generate_t1_init_event(struct timer_list *t)
 332 {
 333         struct sctp_association *asoc =
 334                 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_T1_INIT]);
 335
 336         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
 337 }
 338
 339 static void sctp_generate_t2_shutdown_event(struct timer_list *t)
 340 {
 341         struct sctp_association *asoc =
 342                 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN]);
 343
 344         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
 345 }
 346
 347 static void sctp_generate_t4_rto_event(struct timer_list *t)
 348 {
 349         struct sctp_association *asoc =
 350                 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_T4_RTO]);
 351
 352         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
 353 }
 354
 355 static void sctp_generate_t5_shutdown_guard_event(struct timer_list *t)
 356 {
 357         struct sctp_association *asoc =
 358                 from_timer(asoc, t,
 359                            timers[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD]);
 360
 361         sctp_generate_timeout_event(asoc,
 362                                     SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);
 363
 364 } /* sctp_generate_t5_shutdown_guard_event() */
 365
 366 static void sctp_generate_autoclose_event(struct timer_list *t)
 367 {
 368         struct sctp_association *asoc =
 369                 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_AUTOCLOSE]);
 370
 371         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE);
 372 }
 373
 374 /* Generate a heart beat event.  If the sock is busy, reschedule.   Make
 375  * sure that the transport is still valid.
 376  */
 377 void sctp_generate_heartbeat_event(struct timer_list *t)
 378 {
 379         struct sctp_transport *transport = from_timer(transport, t, hb_timer);
 380         struct sctp_association *asoc = transport->asoc;
 381         struct sock *sk = asoc->base.sk;
 382         struct net *net = sock_net(sk);
 383         u32 elapsed, timeout;
 384         int error = 0;
 385
 386         bh_lock_sock(sk);
 387         if (sock_owned_by_user(sk)) {
 388                 pr_debug("%s: sock is busy\n", __func__);
 389
 390                 /* Try again later.  */
 391                 if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20)))
 392                         sctp_transport_hold(transport);
 393                 goto out_unlock;
 394         }
 395
 396         /* Check if we should still send the heartbeat or reschedule */
 397         elapsed = jiffies - transport->last_time_sent;
 398         timeout = sctp_transport_timeout(transport);
 399         if (elapsed < timeout) {
 400                 elapsed = timeout - elapsed;
 401                 if (!mod_timer(&transport->hb_timer, jiffies + elapsed))
 402                         sctp_transport_hold(transport);
 403                 goto out_unlock;
 404         }
 405
 406         error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
 407                            SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
 408                            asoc->state, asoc->ep, asoc,
 409                            transport, GFP_ATOMIC);
 410
 411         if (error)
 412                 sk->sk_err = -error;
 413
 414 out_unlock:
 415         bh_unlock_sock(sk);
 416         sctp_transport_put(transport);
 417 }
 418
 419 /* Handle the timeout of the ICMP protocol unreachable timer.  Trigger
 420  * the correct state machine transition that will close the association.
 421  */
 422 void sctp_generate_proto_unreach_event(struct timer_list *t)
 423 {
 424         struct sctp_transport *transport =
 425                 from_timer(transport, t, proto_unreach_timer);
 426         struct sctp_association *asoc = transport->asoc;
 427         struct sock *sk = asoc->base.sk;
 428         struct net *net = sock_net(sk);
 429
 430         bh_lock_sock(sk);
 431         if (sock_owned_by_user(sk)) {
 432                 pr_debug("%s: sock is busy\n", __func__);
 433
 434                 /* Try again later.  */
 435                 if (!mod_timer(&transport->proto_unreach_timer,
 436                                 jiffies + (HZ/20)))
 437                         sctp_association_hold(asoc);
 438                 goto out_unlock;
 439         }
 440
 441         /* Is this structure just waiting around for us to actually
 442          * get destroyed?
 443          */
 444         if (asoc->base.dead)
 445                 goto out_unlock;
 446
 447         sctp_do_sm(net, SCTP_EVENT_T_OTHER,
 448                    SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH),
 449                    asoc->state, asoc->ep, asoc, transport, GFP_ATOMIC);
 450
 451 out_unlock:
 452         bh_unlock_sock(sk);
 453         sctp_association_put(asoc);
 454 }
 455
 456  /* Handle the timeout of the RE-CONFIG timer. */
 457 void sctp_generate_reconf_event(struct timer_list *t)
 458 {
 459         struct sctp_transport *transport =
 460                 from_timer(transport, t, reconf_timer);
 461         struct sctp_association *asoc = transport->asoc;
 462         struct sock *sk = asoc->base.sk;
 463         struct net *net = sock_net(sk);
 464         int error = 0;
 465
 466         bh_lock_sock(sk);
 467         if (sock_owned_by_user(sk)) {
 468                 pr_debug("%s: sock is busy\n", __func__);
 469
 470                 /* Try again later.  */
 471                 if (!mod_timer(&transport->reconf_timer, jiffies + (HZ / 20)))
 472                         sctp_transport_hold(transport);
 473                 goto out_unlock;
 474         }
 475
 476         error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
 477                            SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_RECONF),
 478                            asoc->state, asoc->ep, asoc,
 479                            transport, GFP_ATOMIC);
 480
 481         if (error)
 482                 sk->sk_err = -error;
 483
 484 out_unlock:
 485         bh_unlock_sock(sk);
 486         sctp_transport_put(transport);
 487 }
 488
 489 /* Inject a SACK Timeout event into the state machine.  */
 490 static void sctp_generate_sack_event(struct timer_list *t)
 491 {
 492         struct sctp_association *asoc =
 493                 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_SACK]);
 494
 495         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
 496 }
 497
 498 sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
 499         [SCTP_EVENT_TIMEOUT_NONE] =             NULL,
 500         [SCTP_EVENT_TIMEOUT_T1_COOKIE] =        sctp_generate_t1_cookie_event,
 501         [SCTP_EVENT_TIMEOUT_T1_INIT] =          sctp_generate_t1_init_event,
 502         [SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] =      sctp_generate_t2_shutdown_event,
 503         [SCTP_EVENT_TIMEOUT_T3_RTX] =           NULL,
 504         [SCTP_EVENT_TIMEOUT_T4_RTO] =           sctp_generate_t4_rto_event,
 505         [SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD] =
 506                                         sctp_generate_t5_shutdown_guard_event,
 507         [SCTP_EVENT_TIMEOUT_HEARTBEAT] =        NULL,
 508         [SCTP_EVENT_TIMEOUT_RECONF] =           NULL,
 509         [SCTP_EVENT_TIMEOUT_SACK] =             sctp_generate_sack_event,
 510         [SCTP_EVENT_TIMEOUT_AUTOCLOSE] =        sctp_generate_autoclose_event,
 511 };
 512
 513
 514 /* RFC 2960 8.2 Path Failure Detection
 515  *
 516  * When its peer endpoint is multi-homed, an endpoint should keep a
 517  * error counter for each of the destination transport addresses of the
 518  * peer endpoint.
 519  *
 520  * Each time the T3-rtx timer expires on any address, or when a
 521  * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
 522  * the error counter of that destination address will be incremented.
 523  * When the value in the error counter exceeds the protocol parameter
 524  * 'Path.Max.Retrans' of that destination address, the endpoint should
 525  * mark the destination transport address as inactive, and a
 526  * notification SHOULD be sent to the upper layer.
 527  *
 528  */
 529 static void sctp_do_8_2_transport_strike(struct sctp_cmd_seq *commands,
 530                                          struct sctp_association *asoc,
 531                                          struct sctp_transport *transport,
 532                                          int is_hb)
 533 {
 534         struct net *net = sock_net(asoc->base.sk);
 535
 536         /* The check for association's overall error counter exceeding the
 537          * threshold is done in the state function.
 538          */
 539         /* We are here due to a timer expiration.  If the timer was
 540          * not a HEARTBEAT, then normal error tracking is done.
 541          * If the timer was a heartbeat, we only increment error counts
 542          * when we already have an outstanding HEARTBEAT that has not
 543          * been acknowledged.
 544          * Additionally, some tranport states inhibit error increments.
 545          */
 546         if (!is_hb) {
 547                 asoc->overall_error_count++;
 548                 if (transport->state != SCTP_INACTIVE)
 549                         transport->error_count++;
 550          } else if (transport->hb_sent) {
 551                 if (transport->state != SCTP_UNCONFIRMED)
 552                         asoc->overall_error_count++;
 553                 if (transport->state != SCTP_INACTIVE)
 554                         transport->error_count++;
 555         }
 556
 557         /* If the transport error count is greater than the pf_retrans
 558          * threshold, and less than pathmaxrtx, and if the current state
 559          * is SCTP_ACTIVE, then mark this transport as Partially Failed,
 560          * see SCTP Quick Failover Draft, section 5.1
 561          */
 562         if (net->sctp.pf_enable &&
 563            (transport->state == SCTP_ACTIVE) &&
 564            (asoc->pf_retrans < transport->pathmaxrxt) &&
 565            (transport->error_count > asoc->pf_retrans)) {
 566
 567                 sctp_assoc_control_transport(asoc, transport,
 568                                              SCTP_TRANSPORT_PF,
 569                                              0);
 570
 571                 /* Update the hb timer to resend a heartbeat every rto */
 572                 sctp_transport_reset_hb_timer(transport);
 573         }
 574
 575         if (transport->state != SCTP_INACTIVE &&
 576             (transport->error_count > transport->pathmaxrxt)) {
 577                 pr_debug("%s: association:%p transport addr:%pISpc failed\n",
 578                          __func__, asoc, &transport->ipaddr.sa);
 579
 580                 sctp_assoc_control_transport(asoc, transport,
 581                                              SCTP_TRANSPORT_DOWN,
 582                                              SCTP_FAILED_THRESHOLD);
 583         }
 584
 585         /* E2) For the destination address for which the timer
 586          * expires, set RTO <- RTO * 2 ("back off the timer").  The
 587          * maximum value discussed in rule C7 above (RTO.max) may be
 588          * used to provide an upper bound to this doubling operation.
 589          *
 590          * Special Case:  the first HB doesn't trigger exponential backoff.
 591          * The first unacknowledged HB triggers it.  We do this with a flag
 592          * that indicates that we have an outstanding HB.
 593          */
 594         if (!is_hb || transport->hb_sent) {
 595                 transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
 596                 sctp_max_rto(asoc, transport);
 597         }
 598 }
 599
 600 /* Worker routine to handle INIT command failure.  */
 601 static void sctp_cmd_init_failed(struct sctp_cmd_seq *commands,
 602                                  struct sctp_association *asoc,
 603                                  unsigned int error)
 604 {
 605         struct sctp_ulpevent *event;
 606
 607         event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_CANT_STR_ASSOC,
 608                                                 (__u16)error, 0, 0, NULL,
 609                                                 GFP_ATOMIC);
 610
 611         if (event)
 612                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 613                                 SCTP_ULPEVENT(event));
 614
 615         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 616                         SCTP_STATE(SCTP_STATE_CLOSED));
 617
 618         /* SEND_FAILED sent later when cleaning up the association. */
 619         asoc->outqueue.error = error;
 620         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 621 }
 622
 623 /* Worker routine to handle SCTP_CMD_ASSOC_FAILED.  */
 624 static void sctp_cmd_assoc_failed(struct sctp_cmd_seq *commands,
 625                                   struct sctp_association *asoc,
 626                                   enum sctp_event event_type,
 627                                   union sctp_subtype subtype,
 628                                   struct sctp_chunk *chunk,
 629                                   unsigned int error)
 630 {
 631         struct sctp_ulpevent *event;
 632         struct sctp_chunk *abort;
 633
 634         /* Cancel any partial delivery in progress. */
 635         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
 636
 637         if (event_type == SCTP_EVENT_T_CHUNK && subtype.chunk == SCTP_CID_ABORT)
 638                 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
 639                                                 (__u16)error, 0, 0, chunk,
 640                                                 GFP_ATOMIC);
 641         else
 642                 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
 643                                                 (__u16)error, 0, 0, NULL,
 644                                                 GFP_ATOMIC);
 645         if (event)
 646                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 647                                 SCTP_ULPEVENT(event));
 648
 649         if (asoc->overall_error_count >= asoc->max_retrans) {
 650                 abort = sctp_make_violation_max_retrans(asoc, chunk);
 651                 if (abort)
 652                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
 653                                         SCTP_CHUNK(abort));
 654         }
 655
 656         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 657                         SCTP_STATE(SCTP_STATE_CLOSED));
 658
 659         /* SEND_FAILED sent later when cleaning up the association. */
 660         asoc->outqueue.error = error;
 661         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 662 }
 663
 664 /* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
 665  * inside the cookie.  In reality, this is only used for INIT-ACK processing
 666  * since all other cases use "temporary" associations and can do all
 667  * their work in statefuns directly.
 668  */
 669 static int sctp_cmd_process_init(struct sctp_cmd_seq *commands,
 670                                  struct sctp_association *asoc,
 671                                  struct sctp_chunk *chunk,
 672                                  struct sctp_init_chunk *peer_init,
 673                                  gfp_t gfp)
 674 {
 675         int error;
 676
 677         /* We only process the init as a sideeffect in a single
 678          * case.   This is when we process the INIT-ACK.   If we
 679          * fail during INIT processing (due to malloc problems),
 680          * just return the error and stop processing the stack.
 681          */
 682         if (!sctp_process_init(asoc, chunk, sctp_source(chunk), peer_init, gfp))
 683                 error = -ENOMEM;
 684         else
 685                 error = 0;
 686
 687         return error;
 688 }
 689
 690 /* Helper function to break out starting up of heartbeat timers.  */
 691 static void sctp_cmd_hb_timers_start(struct sctp_cmd_seq *cmds,
 692                                      struct sctp_association *asoc)
 693 {
 694         struct sctp_transport *t;
 695
 696         /* Start a heartbeat timer for each transport on the association.
 697          * hold a reference on the transport to make sure none of
 698          * the needed data structures go away.
 699          */
 700         list_for_each_entry(t, &asoc->peer.transport_addr_list, transports)
 701                 sctp_transport_reset_hb_timer(t);
 702 }
 703
 704 static void sctp_cmd_hb_timers_stop(struct sctp_cmd_seq *cmds,
 705                                     struct sctp_association *asoc)
 706 {
 707         struct sctp_transport *t;
 708
 709         /* Stop all heartbeat timers. */
 710
 711         list_for_each_entry(t, &asoc->peer.transport_addr_list,
 712                         transports) {
 713                 if (del_timer(&t->hb_timer))
 714                         sctp_transport_put(t);
 715         }
 716 }
 717
 718 /* Helper function to stop any pending T3-RTX timers */
 719 static void sctp_cmd_t3_rtx_timers_stop(struct sctp_cmd_seq *cmds,
 720                                         struct sctp_association *asoc)
 721 {
 722         struct sctp_transport *t;
 723
 724         list_for_each_entry(t, &asoc->peer.transport_addr_list,
 725                         transports) {
 726                 if (del_timer(&t->T3_rtx_timer))
 727                         sctp_transport_put(t);
 728         }
 729 }
 730
 731
 732 /* Helper function to handle the reception of an HEARTBEAT ACK.  */
 733 static void sctp_cmd_transport_on(struct sctp_cmd_seq *cmds,
 734                                   struct sctp_association *asoc,
 735                                   struct sctp_transport *t,
 736                                   struct sctp_chunk *chunk)
 737 {
 738         struct sctp_sender_hb_info *hbinfo;
 739         int was_unconfirmed = 0;
 740
 741         /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
 742          * HEARTBEAT should clear the error counter of the destination
 743          * transport address to which the HEARTBEAT was sent.
 744          */
 745         t->error_count = 0;
 746
 747         /*
 748          * Although RFC4960 specifies that the overall error count must
 749          * be cleared when a HEARTBEAT ACK is received, we make an
 750          * exception while in SHUTDOWN PENDING. If the peer keeps its
 751          * window shut forever, we may never be able to transmit our
 752          * outstanding data and rely on the retransmission limit be reached
 753          * to shutdown the association.
 754          */
 755         if (t->asoc->state < SCTP_STATE_SHUTDOWN_PENDING)
 756                 t->asoc->overall_error_count = 0;
 757
 758         /* Clear the hb_sent flag to signal that we had a good
 759          * acknowledgement.
 760          */
 761         t->hb_sent = 0;
 762
 763         /* Mark the destination transport address as active if it is not so
 764          * marked.
 765          */
 766         if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED)) {
 767                 was_unconfirmed = 1;
 768                 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
 769                                              SCTP_HEARTBEAT_SUCCESS);
 770         }
 771
 772         if (t->state == SCTP_PF)
 773                 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
 774                                              SCTP_HEARTBEAT_SUCCESS);
 775
 776         /* HB-ACK was received for a the proper HB.  Consider this
 777          * forward progress.
 778          */
 779         if (t->dst)
 780                 sctp_transport_dst_confirm(t);
 781
 782         /* The receiver of the HEARTBEAT ACK should also perform an
 783          * RTT measurement for that destination transport address
 784          * using the time value carried in the HEARTBEAT ACK chunk.
 785          * If the transport's rto_pending variable has been cleared,
 786          * it was most likely due to a retransmit.  However, we want
 787          * to re-enable it to properly update the rto.
 788          */
 789         if (t->rto_pending == 0)
 790                 t->rto_pending = 1;
 791
 792         hbinfo = (struct sctp_sender_hb_info *)chunk->skb->data;
 793         sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
 794
 795         /* Update the heartbeat timer.  */
 796         sctp_transport_reset_hb_timer(t);
 797
 798         if (was_unconfirmed && asoc->peer.transport_count == 1)
 799                 sctp_transport_immediate_rtx(t);
 800 }
 801
 802
 803 /* Helper function to process the process SACK command.  */
 804 static int sctp_cmd_process_sack(struct sctp_cmd_seq *cmds,
 805                                  struct sctp_association *asoc,
 806                                  struct sctp_chunk *chunk)
 807 {
 808         int err = 0;
 809
 810         if (sctp_outq_sack(&asoc->outqueue, chunk)) {
 811                 struct net *net = sock_net(asoc->base.sk);
 812
 813                 /* There are no more TSNs awaiting SACK.  */
 814                 err = sctp_do_sm(net, SCTP_EVENT_T_OTHER,
 815                                  SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
 816                                  asoc->state, asoc->ep, asoc, NULL,
 817                                  GFP_ATOMIC);
 818         }
 819
 820         return err;
 821 }
 822
 823 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
 824  * the transport for a shutdown chunk.
 825  */
 826 static void sctp_cmd_setup_t2(struct sctp_cmd_seq *cmds,
 827                               struct sctp_association *asoc,
 828                               struct sctp_chunk *chunk)
 829 {
 830         struct sctp_transport *t;
 831
 832         if (chunk->transport)
 833                 t = chunk->transport;
 834         else {
 835                 t = sctp_assoc_choose_alter_transport(asoc,
 836                                               asoc->shutdown_last_sent_to);
 837                 chunk->transport = t;
 838         }
 839         asoc->shutdown_last_sent_to = t;
 840         asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
 841 }
 842
 843 static void sctp_cmd_assoc_update(struct sctp_cmd_seq *cmds,
 844                                   struct sctp_association *asoc,
 845                                   struct sctp_association *new)
 846 {
 847         struct net *net = sock_net(asoc->base.sk);
 848         struct sctp_chunk *abort;
 849
 850         if (!sctp_assoc_update(asoc, new))
 851                 return;
 852
 853         abort = sctp_make_abort(asoc, NULL, sizeof(struct sctp_errhdr));
 854         if (abort) {
 855                 sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0);
 856                 sctp_add_cmd_sf(cmds, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
 857         }
 858         sctp_add_cmd_sf(cmds, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNABORTED));
 859         sctp_add_cmd_sf(cmds, SCTP_CMD_ASSOC_FAILED,
 860                         SCTP_PERR(SCTP_ERROR_RSRC_LOW));
 861         SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
 862         SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
 863 }
 864
 865 /* Helper function to change the state of an association. */
 866 static void sctp_cmd_new_state(struct sctp_cmd_seq *cmds,
 867                                struct sctp_association *asoc,
 868                                enum sctp_state state)
 869 {
 870         struct sock *sk = asoc->base.sk;
 871
 872         asoc->state = state;
 873
 874         pr_debug("%s: asoc:%p[%s]\n", __func__, asoc, sctp_state_tbl[state]);
 875
 876         if (sctp_style(sk, TCP)) {
 877                 /* Change the sk->sk_state of a TCP-style socket that has
 878                  * successfully completed a connect() call.
 879                  */
 880                 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
 881                         sk->sk_state = SCTP_SS_ESTABLISHED;
 882
 883                 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
 884                 if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
 885                     sctp_sstate(sk, ESTABLISHED)) {
 886                         sk->sk_state = SCTP_SS_CLOSING;
 887                         sk->sk_shutdown |= RCV_SHUTDOWN;
 888                 }
 889         }
 890
 891         if (sctp_state(asoc, COOKIE_WAIT)) {
 892                 /* Reset init timeouts since they may have been
 893                  * increased due to timer expirations.
 894                  */
 895                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
 896                                                 asoc->rto_initial;
 897                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
 898                                                 asoc->rto_initial;
 899         }
 900
 901         if (sctp_state(asoc, ESTABLISHED) ||
 902             sctp_state(asoc, CLOSED) ||
 903             sctp_state(asoc, SHUTDOWN_RECEIVED)) {
 904                 /* Wake up any processes waiting in the asoc's wait queue in
 905                  * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
 906                  */
 907                 if (waitqueue_active(&asoc->wait))
 908                         wake_up_interruptible(&asoc->wait);
 909
 910                 /* Wake up any processes waiting in the sk's sleep queue of
 911                  * a TCP-style or UDP-style peeled-off socket in
 912                  * sctp_wait_for_accept() or sctp_wait_for_packet().
 913                  * For a UDP-style socket, the waiters are woken up by the
 914                  * notifications.
 915                  */
 916                 if (!sctp_style(sk, UDP))
 917                         sk->sk_state_change(sk);
 918         }
 919
 920         if (sctp_state(asoc, SHUTDOWN_PENDING) &&
 921             !sctp_outq_is_empty(&asoc->outqueue))
 922                 sctp_outq_uncork(&asoc->outqueue, GFP_ATOMIC);
 923 }
 924
 925 /* Helper function to delete an association. */
 926 static void sctp_cmd_delete_tcb(struct sctp_cmd_seq *cmds,
 927                                 struct sctp_association *asoc)
 928 {
 929         struct sock *sk = asoc->base.sk;
 930
 931         /* If it is a non-temporary association belonging to a TCP-style
 932          * listening socket that is not closed, do not free it so that accept()
 933          * can pick it up later.
 934          */
 935         if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
 936             (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
 937                 return;
 938
 939         sctp_association_free(asoc);
 940 }
 941
 942 /*
 943  * ADDIP Section 4.1 ASCONF Chunk Procedures
 944  * A4) Start a T-4 RTO timer, using the RTO value of the selected
 945  * destination address (we use active path instead of primary path just
 946  * because primary path may be inactive.
 947  */
 948 static void sctp_cmd_setup_t4(struct sctp_cmd_seq *cmds,
 949                               struct sctp_association *asoc,
 950                               struct sctp_chunk *chunk)
 951 {
 952         struct sctp_transport *t;
 953
 954         t = sctp_assoc_choose_alter_transport(asoc, chunk->transport);
 955         asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
 956         chunk->transport = t;
 957 }
 958
 959 /* Process an incoming Operation Error Chunk. */
 960 static void sctp_cmd_process_operr(struct sctp_cmd_seq *cmds,
 961                                    struct sctp_association *asoc,
 962                                    struct sctp_chunk *chunk)
 963 {
 964         struct sctp_errhdr *err_hdr;
 965         struct sctp_ulpevent *ev;
 966
 967         while (chunk->chunk_end > chunk->skb->data) {
 968                 err_hdr = (struct sctp_errhdr *)(chunk->skb->data);
 969
 970                 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
 971                                                      GFP_ATOMIC);
 972                 if (!ev)
 973                         return;
 974
 975                 sctp_ulpq_tail_event(&asoc->ulpq, ev);
 976
 977                 switch (err_hdr->cause) {
 978                 case SCTP_ERROR_UNKNOWN_CHUNK:
 979                 {
 980                         struct sctp_chunkhdr *unk_chunk_hdr;
 981
 982                         unk_chunk_hdr = (struct sctp_chunkhdr *)
 983                                                         err_hdr->variable;
 984                         switch (unk_chunk_hdr->type) {
 985                         /* ADDIP 4.1 A9) If the peer responds to an ASCONF with
 986                          * an ERROR chunk reporting that it did not recognized
 987                          * the ASCONF chunk type, the sender of the ASCONF MUST
 988                          * NOT send any further ASCONF chunks and MUST stop its
 989                          * T-4 timer.
 990                          */
 991                         case SCTP_CID_ASCONF:
 992                                 if (asoc->peer.asconf_capable == 0)
 993                                         break;
 994
 995                                 asoc->peer.asconf_capable = 0;
 996                                 sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
 997                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
 998                                 break;
 999                         default:
1000                                 break;
1001                         }
1002                         break;
1003                 }
1004                 default:
1005                         break;
1006                 }
1007         }
1008 }
1009
1010 /* Process variable FWDTSN chunk information. */
1011 static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq,
1012                                     struct sctp_chunk *chunk)
1013 {
1014         struct sctp_fwdtsn_skip *skip;
1015
1016         /* Walk through all the skipped SSNs */
1017         sctp_walk_fwdtsn(skip, chunk) {
1018                 sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
1019         }
1020 }
1021
1022 /* Helper function to remove the association non-primary peer
1023  * transports.
1024  */
1025 static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
1026 {
1027         struct sctp_transport *t;
1028         struct list_head *temp;
1029         struct list_head *pos;
1030
1031         list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
1032                 t = list_entry(pos, struct sctp_transport, transports);
1033                 if (!sctp_cmp_addr_exact(&t->ipaddr,
1034                                          &asoc->peer.primary_addr)) {
1035                         sctp_assoc_rm_peer(asoc, t);
1036                 }
1037         }
1038 }
1039
1040 /* Helper function to set sk_err on a 1-1 style socket. */
1041 static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
1042 {
1043         struct sock *sk = asoc->base.sk;
1044
1045         if (!sctp_style(sk, UDP))
1046                 sk->sk_err = error;
1047 }
1048
1049 /* Helper function to generate an association change event */
1050 static void sctp_cmd_assoc_change(struct sctp_cmd_seq *commands,
1051                                   struct sctp_association *asoc,
1052                                   u8 state)
1053 {
1054         struct sctp_ulpevent *ev;
1055
1056         ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0,
1057                                             asoc->c.sinit_num_ostreams,
1058                                             asoc->c.sinit_max_instreams,
1059                                             NULL, GFP_ATOMIC);
1060         if (ev)
1061                 sctp_ulpq_tail_event(&asoc->ulpq, ev);
1062 }
1063
1064 /* Helper function to generate an adaptation indication event */
1065 static void sctp_cmd_adaptation_ind(struct sctp_cmd_seq *commands,
1066                                     struct sctp_association *asoc)
1067 {
1068         struct sctp_ulpevent *ev;
1069
1070         ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
1071
1072         if (ev)
1073                 sctp_ulpq_tail_event(&asoc->ulpq, ev);
1074 }
1075
1076
1077 static void sctp_cmd_t1_timer_update(struct sctp_association *asoc,
1078                                      enum sctp_event_timeout timer,
1079                                      char *name)
1080 {
1081         struct sctp_transport *t;
1082
1083         t = asoc->init_last_sent_to;
1084         asoc->init_err_counter++;
1085
1086         if (t->init_sent_count > (asoc->init_cycle + 1)) {
1087                 asoc->timeouts[timer] *= 2;
1088                 if (asoc->timeouts[timer] > asoc->max_init_timeo) {
1089                         asoc->timeouts[timer] = asoc->max_init_timeo;
1090                 }
1091                 asoc->init_cycle++;
1092
1093                 pr_debug("%s: T1[%s] timeout adjustment init_err_counter:%d"
1094                          " cycle:%d timeout:%ld\n", __func__, name,
1095                          asoc->init_err_counter, asoc->init_cycle,
1096                          asoc->timeouts[timer]);
1097         }
1098
1099 }
1100
1101 /* Send the whole message, chunk by chunk, to the outqueue.
1102  * This way the whole message is queued up and bundling if
1103  * encouraged for small fragments.
1104  */
1105 static void sctp_cmd_send_msg(struct sctp_association *asoc,
1106                               struct sctp_datamsg *msg, gfp_t gfp)
1107 {
1108         struct sctp_chunk *chunk;
1109
1110         list_for_each_entry(chunk, &msg->chunks, frag_list)
1111                 sctp_outq_tail(&asoc->outqueue, chunk, gfp);
1112
1113         asoc->outqueue.sched->enqueue(&asoc->outqueue, msg);
1114 }
1115
1116
1117 /* Sent the next ASCONF packet currently stored in the association.
1118  * This happens after the ASCONF_ACK was succeffully processed.
1119  */
1120 static void sctp_cmd_send_asconf(struct sctp_association *asoc)
1121 {
1122         struct net *net = sock_net(asoc->base.sk);
1123
1124         /* Send the next asconf chunk from the addip chunk
1125          * queue.
1126          */
1127         if (!list_empty(&asoc->addip_chunk_list)) {
1128                 struct list_head *entry = asoc->addip_chunk_list.next;
1129                 struct sctp_chunk *asconf = list_entry(entry,
1130                                                 struct sctp_chunk, list);
1131                 list_del_init(entry);
1132
1133                 /* Hold the chunk until an ASCONF_ACK is received. */
1134                 sctp_chunk_hold(asconf);
1135                 if (sctp_primitive_ASCONF(net, asoc, asconf))
1136                         sctp_chunk_free(asconf);
1137                 else
1138                         asoc->addip_last_asconf = asconf;
1139         }
1140 }
1141
1142
1143 /* These three macros allow us to pull the debugging code out of the
1144  * main flow of sctp_do_sm() to keep attention focused on the real
1145  * functionality there.
1146  */
1147 #define debug_pre_sfn() \
1148         pr_debug("%s[pre-fn]: ep:%p, %s, %s, asoc:%p[%s], %s\n", __func__, \
1149                  ep, sctp_evttype_tbl[event_type], (*debug_fn)(subtype),   \
1150                  asoc, sctp_state_tbl[state], state_fn->name)
1151
1152 #define debug_post_sfn() \
1153         pr_debug("%s[post-fn]: asoc:%p, status:%s\n", __func__, asoc, \
1154                  sctp_status_tbl[status])
1155
1156 #define debug_post_sfx() \
1157         pr_debug("%s[post-sfx]: error:%d, asoc:%p[%s]\n", __func__, error, \
1158                  asoc, sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
1159                  sctp_assoc2id(asoc))) ? asoc->state : SCTP_STATE_CLOSED])
1160
1161 /*
1162  * This is the master state machine processing function.
1163  *
1164  * If you want to understand all of lksctp, this is a
1165  * good place to start.
1166  */
1167 int sctp_do_sm(struct net *net, enum sctp_event event_type,
1168                union sctp_subtype subtype, enum sctp_state state,
1169                struct sctp_endpoint *ep, struct sctp_association *asoc,
1170                void *event_arg, gfp_t gfp)
1171 {
1172         typedef const char *(printfn_t)(union sctp_subtype);
1173         static printfn_t *table[] = {
1174                 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
1175         };
1176         printfn_t *debug_fn  __attribute__ ((unused)) = table[event_type];
1177         const struct sctp_sm_table_entry *state_fn;
1178         struct sctp_cmd_seq commands;
1179         enum sctp_disposition status;
1180         int error = 0;
1181
1182         /* Look up the state function, run it, and then process the
1183          * side effects.  These three steps are the heart of lksctp.
1184          */
1185         state_fn = sctp_sm_lookup_event(net, event_type, state, subtype);
1186
1187         sctp_init_cmd_seq(&commands);
1188
1189         debug_pre_sfn();
1190         status = state_fn->fn(net, ep, asoc, subtype, event_arg, &commands);
1191         debug_post_sfn();
1192
1193         error = sctp_side_effects(event_type, subtype, state,
1194                                   ep, &asoc, event_arg, status,
1195                                   &commands, gfp);
1196         debug_post_sfx();
1197
1198         return error;
1199 }
1200
1201 /*****************************************************************
1202  * This the master state function side effect processing function.
1203  *****************************************************************/
1204 static int sctp_side_effects(enum sctp_event event_type,
1205                              union sctp_subtype subtype,
1206                              enum sctp_state state,
1207                              struct sctp_endpoint *ep,
1208                              struct sctp_association **asoc,
1209                              void *event_arg,
1210                              enum sctp_disposition status,
1211                              struct sctp_cmd_seq *commands,
1212                              gfp_t gfp)
1213 {
1214         int error;
1215
1216         /* FIXME - Most of the dispositions left today would be categorized
1217          * as "exceptional" dispositions.  For those dispositions, it
1218          * may not be proper to run through any of the commands at all.
1219          * For example, the command interpreter might be run only with
1220          * disposition SCTP_DISPOSITION_CONSUME.
1221          */
1222         if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
1223                                                ep, *asoc,
1224                                                event_arg, status,
1225                                                commands, gfp)))
1226                 goto bail;
1227
1228         switch (status) {
1229         case SCTP_DISPOSITION_DISCARD:
1230                 pr_debug("%s: ignored sctp protocol event - state:%d, "
1231                          "event_type:%d, event_id:%d\n", __func__, state,
1232                          event_type, subtype.chunk);
1233                 break;
1234
1235         case SCTP_DISPOSITION_NOMEM:
1236                 /* We ran out of memory, so we need to discard this
1237                  * packet.
1238                  */
1239                 /* BUG--we should now recover some memory, probably by
1240                  * reneging...
1241                  */
1242                 error = -ENOMEM;
1243                 break;
1244
1245         case SCTP_DISPOSITION_DELETE_TCB:
1246         case SCTP_DISPOSITION_ABORT:
1247                 /* This should now be a command. */
1248                 *asoc = NULL;
1249                 break;
1250
1251         case SCTP_DISPOSITION_CONSUME:
1252                 /*
1253                  * We should no longer have much work to do here as the
1254                  * real work has been done as explicit commands above.
1255                  */
1256                 break;
1257
1258         case SCTP_DISPOSITION_VIOLATION:
1259                 net_err_ratelimited("protocol violation state %d chunkid %d\n",
1260                                     state, subtype.chunk);
1261                 break;
1262
1263         case SCTP_DISPOSITION_NOT_IMPL:
1264                 pr_warn("unimplemented feature in state %d, event_type %d, event_id %d\n",
1265                         state, event_type, subtype.chunk);
1266                 break;
1267
1268         case SCTP_DISPOSITION_BUG:
1269                 pr_err("bug in state %d, event_type %d, event_id %d\n",
1270                        state, event_type, subtype.chunk);
1271                 BUG();
1272                 break;
1273
1274         default:
1275                 pr_err("impossible disposition %d in state %d, event_type %d, event_id %d\n",
1276                        status, state, event_type, subtype.chunk);
1277                 BUG();
1278                 break;
1279         }
1280
1281 bail:
1282         return error;
1283 }
1284
1285 /********************************************************************
1286  * 2nd Level Abstractions
1287  ********************************************************************/
1288
1289 /* This is the side-effect interpreter.  */
1290 static int sctp_cmd_interpreter(enum sctp_event event_type,
1291                                 union sctp_subtype subtype,
1292                                 enum sctp_state state,
1293                                 struct sctp_endpoint *ep,
1294                                 struct sctp_association *asoc,
1295                                 void *event_arg,
1296                                 enum sctp_disposition status,
1297                                 struct sctp_cmd_seq *commands,
1298                                 gfp_t gfp)
1299 {
1300         struct sctp_sock *sp = sctp_sk(ep->base.sk);
1301         struct sctp_chunk *chunk = NULL, *new_obj;
1302         struct sctp_packet *packet;
1303         struct sctp_sackhdr sackh;
1304         struct timer_list *timer;
1305         struct sctp_transport *t;
1306         unsigned long timeout;
1307         struct sctp_cmd *cmd;
1308         int local_cork = 0;
1309         int error = 0;
1310         int force;
1311
1312         if (SCTP_EVENT_T_TIMEOUT != event_type)
1313                 chunk = event_arg;
1314
1315         /* Note:  This whole file is a huge candidate for rework.
1316          * For example, each command could either have its own handler, so
1317          * the loop would look like:
1318          *     while (cmds)
1319          *         cmd->handle(x, y, z)
1320          * --jgrimm
1321          */
1322         while (NULL != (cmd = sctp_next_cmd(commands))) {
1323                 switch (cmd->verb) {
1324                 case SCTP_CMD_NOP:
1325                         /* Do nothing. */
1326                         break;
1327
1328                 case SCTP_CMD_NEW_ASOC:
1329                         /* Register a new association.  */
1330                         if (local_cork) {
1331                                 sctp_outq_uncork(&asoc->outqueue, gfp);
1332                                 local_cork = 0;
1333                         }
1334
1335                         /* Register with the endpoint.  */
1336                         asoc = cmd->obj.asoc;
1337                         BUG_ON(asoc->peer.primary_path == NULL);
1338                         sctp_endpoint_add_asoc(ep, asoc);
1339                         break;
1340
1341                 case SCTP_CMD_UPDATE_ASSOC:
1342                        sctp_cmd_assoc_update(commands, asoc, cmd->obj.asoc);
1343                        break;
1344
1345                 case SCTP_CMD_PURGE_OUTQUEUE:
1346                        sctp_outq_teardown(&asoc->outqueue);
1347                        break;
1348
1349                 case SCTP_CMD_DELETE_TCB:
1350                         if (local_cork) {
1351                                 sctp_outq_uncork(&asoc->outqueue, gfp);
1352                                 local_cork = 0;
1353                         }
1354                         /* Delete the current association.  */
1355                         sctp_cmd_delete_tcb(commands, asoc);
1356                         asoc = NULL;
1357                         break;
1358
1359                 case SCTP_CMD_NEW_STATE:
1360                         /* Enter a new state.  */
1361                         sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1362                         break;
1363
1364                 case SCTP_CMD_REPORT_TSN:
1365                         /* Record the arrival of a TSN.  */
1366                         error = sctp_tsnmap_mark(&asoc->peer.tsn_map,
1367                                                  cmd->obj.u32, NULL);
1368                         break;
1369
1370                 case SCTP_CMD_REPORT_FWDTSN:
1371                         /* Move the Cumulattive TSN Ack ahead. */
1372                         sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32);
1373
1374                         /* purge the fragmentation queue */
1375                         sctp_ulpq_reasm_flushtsn(&asoc->ulpq, cmd->obj.u32);
1376
1377                         /* Abort any in progress partial delivery. */
1378                         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
1379                         break;
1380
1381                 case SCTP_CMD_PROCESS_FWDTSN:
1382                         sctp_cmd_process_fwdtsn(&asoc->ulpq, cmd->obj.chunk);
1383                         break;
1384
1385                 case SCTP_CMD_GEN_SACK:
1386                         /* Generate a Selective ACK.
1387                          * The argument tells us whether to just count
1388                          * the packet and MAYBE generate a SACK, or
1389                          * force a SACK out.
1390                          */
1391                         force = cmd->obj.i32;
1392                         error = sctp_gen_sack(asoc, force, commands);
1393                         break;
1394
1395                 case SCTP_CMD_PROCESS_SACK:
1396                         /* Process an inbound SACK.  */
1397                         error = sctp_cmd_process_sack(commands, asoc,
1398                                                       cmd->obj.chunk);
1399                         break;
1400
1401                 case SCTP_CMD_GEN_INIT_ACK:
1402                         /* Generate an INIT ACK chunk.  */
1403                         new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1404                                                      0);
1405                         if (!new_obj)
1406                                 goto nomem;
1407
1408                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1409                                         SCTP_CHUNK(new_obj));
1410                         break;
1411
1412                 case SCTP_CMD_PEER_INIT:
1413                         /* Process a unified INIT from the peer.
1414                          * Note: Only used during INIT-ACK processing.  If
1415                          * there is an error just return to the outter
1416                          * layer which will bail.
1417                          */
1418                         error = sctp_cmd_process_init(commands, asoc, chunk,
1419                                                       cmd->obj.init, gfp);
1420                         break;
1421
1422                 case SCTP_CMD_GEN_COOKIE_ECHO:
1423                         /* Generate a COOKIE ECHO chunk.  */
1424                         new_obj = sctp_make_cookie_echo(asoc, chunk);
1425                         if (!new_obj) {
1426                                 if (cmd->obj.chunk)
1427                                         sctp_chunk_free(cmd->obj.chunk);
1428                                 goto nomem;
1429                         }
1430                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1431                                         SCTP_CHUNK(new_obj));
1432
1433                         /* If there is an ERROR chunk to be sent along with
1434                          * the COOKIE_ECHO, send it, too.
1435                          */
1436                         if (cmd->obj.chunk)
1437                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1438                                                 SCTP_CHUNK(cmd->obj.chunk));
1439
1440                         if (new_obj->transport) {
1441                                 new_obj->transport->init_sent_count++;
1442                                 asoc->init_last_sent_to = new_obj->transport;
1443                         }
1444
1445                         /* FIXME - Eventually come up with a cleaner way to
1446                          * enabling COOKIE-ECHO + DATA bundling during
1447                          * multihoming stale cookie scenarios, the following
1448                          * command plays with asoc->peer.retran_path to
1449                          * avoid the problem of sending the COOKIE-ECHO and
1450                          * DATA in different paths, which could result
1451                          * in the association being ABORTed if the DATA chunk
1452                          * is processed first by the server.  Checking the
1453                          * init error counter simply causes this command
1454                          * to be executed only during failed attempts of
1455                          * association establishment.
1456                          */
1457                         if ((asoc->peer.retran_path !=
1458                              asoc->peer.primary_path) &&
1459                             (asoc->init_err_counter > 0)) {
1460                                 sctp_add_cmd_sf(commands,
1461                                                 SCTP_CMD_FORCE_PRIM_RETRAN,
1462                                                 SCTP_NULL());
1463                         }
1464
1465                         break;
1466
1467                 case SCTP_CMD_GEN_SHUTDOWN:
1468                         /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1469                          * Reset error counts.
1470                          */
1471                         asoc->overall_error_count = 0;
1472
1473                         /* Generate a SHUTDOWN chunk.  */
1474                         new_obj = sctp_make_shutdown(asoc, chunk);
1475                         if (!new_obj)
1476                                 goto nomem;
1477                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1478                                         SCTP_CHUNK(new_obj));
1479                         break;
1480
1481                 case SCTP_CMD_CHUNK_ULP:
1482                         /* Send a chunk to the sockets layer.  */
1483                         pr_debug("%s: sm_sideff: chunk_up:%p, ulpq:%p\n",
1484                                  __func__, cmd->obj.chunk, &asoc->ulpq);
1485
1486                         asoc->stream.si->ulpevent_data(&asoc->ulpq,
1487                                                        cmd->obj.chunk,
1488                                                        GFP_ATOMIC);
1489                         break;
1490
1491                 case SCTP_CMD_EVENT_ULP:
1492                         /* Send a notification to the sockets layer.  */
1493                         pr_debug("%s: sm_sideff: event_up:%p, ulpq:%p\n",
1494                                  __func__, cmd->obj.ulpevent, &asoc->ulpq);
1495
1496                         sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ulpevent);
1497                         break;
1498
1499                 case SCTP_CMD_REPLY:
1500                         /* If an caller has not already corked, do cork. */
1501                         if (!asoc->outqueue.cork) {
1502                                 sctp_outq_cork(&asoc->outqueue);
1503                                 local_cork = 1;
1504                         }
1505                         /* Send a chunk to our peer.  */
1506                         sctp_outq_tail(&asoc->outqueue, cmd->obj.chunk, gfp);
1507                         break;
1508
1509                 case SCTP_CMD_SEND_PKT:
1510                         /* Send a full packet to our peer.  */
1511                         packet = cmd->obj.packet;
1512                         sctp_packet_transmit(packet, gfp);
1513                         sctp_ootb_pkt_free(packet);
1514                         break;
1515
1516                 case SCTP_CMD_T1_RETRAN:
1517                         /* Mark a transport for retransmission.  */
1518                         sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1519                                         SCTP_RTXR_T1_RTX);
1520                         break;
1521
1522                 case SCTP_CMD_RETRAN:
1523                         /* Mark a transport for retransmission.  */
1524                         sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1525                                         SCTP_RTXR_T3_RTX);
1526                         break;
1527
1528                 case SCTP_CMD_ECN_CE:
1529                         /* Do delayed CE processing.   */
1530                         sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1531                         break;
1532
1533                 case SCTP_CMD_ECN_ECNE:
1534                         /* Do delayed ECNE processing. */
1535                         new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1536                                                         chunk);
1537                         if (new_obj)
1538                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1539                                                 SCTP_CHUNK(new_obj));
1540                         break;
1541
1542                 case SCTP_CMD_ECN_CWR:
1543                         /* Do delayed CWR processing.  */
1544                         sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1545                         break;
1546
1547                 case SCTP_CMD_SETUP_T2:
1548                         sctp_cmd_setup_t2(commands, asoc, cmd->obj.chunk);
1549                         break;
1550
1551                 case SCTP_CMD_TIMER_START_ONCE:
1552                         timer = &asoc->timers[cmd->obj.to];
1553
1554                         if (timer_pending(timer))
1555                                 break;
1556                         /* fall through */
1557
1558                 case SCTP_CMD_TIMER_START:
1559                         timer = &asoc->timers[cmd->obj.to];
1560                         timeout = asoc->timeouts[cmd->obj.to];
1561                         BUG_ON(!timeout);
1562
1563                         timer->expires = jiffies + timeout;
1564                         sctp_association_hold(asoc);
1565                         add_timer(timer);
1566                         break;
1567
1568                 case SCTP_CMD_TIMER_RESTART:
1569                         timer = &asoc->timers[cmd->obj.to];
1570                         timeout = asoc->timeouts[cmd->obj.to];
1571                         if (!mod_timer(timer, jiffies + timeout))
1572                                 sctp_association_hold(asoc);
1573                         break;
1574
1575                 case SCTP_CMD_TIMER_STOP:
1576                         timer = &asoc->timers[cmd->obj.to];
1577                         if (del_timer(timer))
1578                                 sctp_association_put(asoc);
1579                         break;
1580
1581                 case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1582                         chunk = cmd->obj.chunk;
1583                         t = sctp_assoc_choose_alter_transport(asoc,
1584                                                 asoc->init_last_sent_to);
1585                         asoc->init_last_sent_to = t;
1586                         chunk->transport = t;
1587                         t->init_sent_count++;
1588                         /* Set the new transport as primary */
1589                         sctp_assoc_set_primary(asoc, t);
1590                         break;
1591
1592                 case SCTP_CMD_INIT_RESTART:
1593                         /* Do the needed accounting and updates
1594                          * associated with restarting an initialization
1595                          * timer. Only multiply the timeout by two if
1596                          * all transports have been tried at the current
1597                          * timeout.
1598                          */
1599                         sctp_cmd_t1_timer_update(asoc,
1600                                                 SCTP_EVENT_TIMEOUT_T1_INIT,
1601                                                 "INIT");
1602
1603                         sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1604                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1605                         break;
1606
1607                 case SCTP_CMD_COOKIEECHO_RESTART:
1608                         /* Do the needed accounting and updates
1609                          * associated with restarting an initialization
1610                          * timer. Only multiply the timeout by two if
1611                          * all transports have been tried at the current
1612                          * timeout.
1613                          */
1614                         sctp_cmd_t1_timer_update(asoc,
1615                                                 SCTP_EVENT_TIMEOUT_T1_COOKIE,
1616                                                 "COOKIE");
1617
1618                         /* If we've sent any data bundled with
1619                          * COOKIE-ECHO we need to resend.
1620                          */
1621                         list_for_each_entry(t, &asoc->peer.transport_addr_list,
1622                                         transports) {
1623                                 sctp_retransmit_mark(&asoc->outqueue, t,
1624                                             SCTP_RTXR_T1_RTX);
1625                         }
1626
1627                         sctp_add_cmd_sf(commands,
1628                                         SCTP_CMD_TIMER_RESTART,
1629                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1630                         break;
1631
1632                 case SCTP_CMD_INIT_FAILED:
1633                         sctp_cmd_init_failed(commands, asoc, cmd->obj.u32);
1634                         break;
1635
1636                 case SCTP_CMD_ASSOC_FAILED:
1637                         sctp_cmd_assoc_failed(commands, asoc, event_type,
1638                                               subtype, chunk, cmd->obj.u32);
1639                         break;
1640
1641                 case SCTP_CMD_INIT_COUNTER_INC:
1642                         asoc->init_err_counter++;
1643                         break;
1644
1645                 case SCTP_CMD_INIT_COUNTER_RESET:
1646                         asoc->init_err_counter = 0;
1647                         asoc->init_cycle = 0;
1648                         list_for_each_entry(t, &asoc->peer.transport_addr_list,
1649                                             transports) {
1650                                 t->init_sent_count = 0;
1651                         }
1652                         break;
1653
1654                 case SCTP_CMD_REPORT_DUP:
1655                         sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1656                                              cmd->obj.u32);
1657                         break;
1658
1659                 case SCTP_CMD_REPORT_BAD_TAG:
1660                         pr_debug("%s: vtag mismatch!\n", __func__);
1661                         break;
1662
1663                 case SCTP_CMD_STRIKE:
1664                         /* Mark one strike against a transport.  */
1665                         sctp_do_8_2_transport_strike(commands, asoc,
1666                                                     cmd->obj.transport, 0);
1667                         break;
1668
1669                 case SCTP_CMD_TRANSPORT_IDLE:
1670                         t = cmd->obj.transport;
1671                         sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
1672                         break;
1673
1674                 case SCTP_CMD_TRANSPORT_HB_SENT:
1675                         t = cmd->obj.transport;
1676                         sctp_do_8_2_transport_strike(commands, asoc,
1677                                                      t, 1);
1678                         t->hb_sent = 1;
1679                         break;
1680
1681                 case SCTP_CMD_TRANSPORT_ON:
1682                         t = cmd->obj.transport;
1683                         sctp_cmd_transport_on(commands, asoc, t, chunk);
1684                         break;
1685
1686                 case SCTP_CMD_HB_TIMERS_START:
1687                         sctp_cmd_hb_timers_start(commands, asoc);
1688                         break;
1689
1690                 case SCTP_CMD_HB_TIMER_UPDATE:
1691                         t = cmd->obj.transport;
1692                         sctp_transport_reset_hb_timer(t);
1693                         break;
1694
1695                 case SCTP_CMD_HB_TIMERS_STOP:
1696                         sctp_cmd_hb_timers_stop(commands, asoc);
1697                         break;
1698
1699                 case SCTP_CMD_REPORT_ERROR:
1700                         error = cmd->obj.error;
1701                         break;
1702
1703                 case SCTP_CMD_PROCESS_CTSN:
1704                         /* Dummy up a SACK for processing. */
1705                         sackh.cum_tsn_ack = cmd->obj.be32;
1706                         sackh.a_rwnd = htonl(asoc->peer.rwnd +
1707                                              asoc->outqueue.outstanding_bytes);
1708                         sackh.num_gap_ack_blocks = 0;
1709                         sackh.num_dup_tsns = 0;
1710                         chunk->subh.sack_hdr = &sackh;
1711                         sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1712                                         SCTP_CHUNK(chunk));
1713                         break;
1714
1715                 case SCTP_CMD_DISCARD_PACKET:
1716                         /* We need to discard the whole packet.
1717                          * Uncork the queue since there might be
1718                          * responses pending
1719                          */
1720                         chunk->pdiscard = 1;
1721                         if (asoc) {
1722                                 sctp_outq_uncork(&asoc->outqueue, gfp);
1723                                 local_cork = 0;
1724                         }
1725                         break;
1726
1727                 case SCTP_CMD_RTO_PENDING:
1728                         t = cmd->obj.transport;
1729                         t->rto_pending = 1;
1730                         break;
1731
1732                 case SCTP_CMD_PART_DELIVER:
1733                         sctp_ulpq_partial_delivery(&asoc->ulpq, GFP_ATOMIC);
1734                         break;
1735
1736                 case SCTP_CMD_RENEGE:
1737                         sctp_ulpq_renege(&asoc->ulpq, cmd->obj.chunk,
1738                                          GFP_ATOMIC);
1739                         break;
1740
1741                 case SCTP_CMD_SETUP_T4:
1742                         sctp_cmd_setup_t4(commands, asoc, cmd->obj.chunk);
1743                         break;
1744
1745                 case SCTP_CMD_PROCESS_OPERR:
1746                         sctp_cmd_process_operr(commands, asoc, chunk);
1747                         break;
1748                 case SCTP_CMD_CLEAR_INIT_TAG:
1749                         asoc->peer.i.init_tag = 0;
1750                         break;
1751                 case SCTP_CMD_DEL_NON_PRIMARY:
1752                         sctp_cmd_del_non_primary(asoc);
1753                         break;
1754                 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1755                         sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1756                         break;
1757                 case SCTP_CMD_FORCE_PRIM_RETRAN:
1758                         t = asoc->peer.retran_path;
1759                         asoc->peer.retran_path = asoc->peer.primary_path;
1760                         sctp_outq_uncork(&asoc->outqueue, gfp);
1761                         local_cork = 0;
1762                         asoc->peer.retran_path = t;
1763                         break;
1764                 case SCTP_CMD_SET_SK_ERR:
1765                         sctp_cmd_set_sk_err(asoc, cmd->obj.error);
1766                         break;
1767                 case SCTP_CMD_ASSOC_CHANGE:
1768                         sctp_cmd_assoc_change(commands, asoc,
1769                                               cmd->obj.u8);
1770                         break;
1771                 case SCTP_CMD_ADAPTATION_IND:
1772                         sctp_cmd_adaptation_ind(commands, asoc);
1773                         break;
1774
1775                 case SCTP_CMD_ASSOC_SHKEY:
1776                         error = sctp_auth_asoc_init_active_key(asoc,
1777                                                 GFP_ATOMIC);
1778                         break;
1779                 case SCTP_CMD_UPDATE_INITTAG:
1780                         asoc->peer.i.init_tag = cmd->obj.u32;
1781                         break;
1782                 case SCTP_CMD_SEND_MSG:
1783                         if (!asoc->outqueue.cork) {
1784                                 sctp_outq_cork(&asoc->outqueue);
1785                                 local_cork = 1;
1786                         }
1787                         sctp_cmd_send_msg(asoc, cmd->obj.msg, gfp);
1788                         break;
1789                 case SCTP_CMD_SEND_NEXT_ASCONF:
1790                         sctp_cmd_send_asconf(asoc);
1791                         break;
1792                 case SCTP_CMD_PURGE_ASCONF_QUEUE:
1793                         sctp_asconf_queue_teardown(asoc);
1794                         break;
1795
1796                 case SCTP_CMD_SET_ASOC:
1797                         if (asoc && local_cork) {
1798                                 sctp_outq_uncork(&asoc->outqueue, gfp);
1799                                 local_cork = 0;
1800                         }
1801                         asoc = cmd->obj.asoc;
1802                         break;
1803
1804                 default:
1805                         pr_warn("Impossible command: %u\n",
1806                                 cmd->verb);
1807                         break;
1808                 }
1809
1810                 if (error)
1811                         break;
1812         }
1813
1814 out:
1815         /* If this is in response to a received chunk, wait until
1816          * we are done with the packet to open the queue so that we don't
1817          * send multiple packets in response to a single request.
1818          */
1819         if (asoc && SCTP_EVENT_T_CHUNK == event_type && chunk) {
1820                 if (chunk->end_of_packet || chunk->singleton)
1821                         sctp_outq_uncork(&asoc->outqueue, gfp);
1822         } else if (local_cork)
1823                 sctp_outq_uncork(&asoc->outqueue, gfp);
1824
1825         if (sp->data_ready_signalled)
1826                 sp->data_ready_signalled = 0;
1827
1828         return error;
1829 nomem:
1830         error = -ENOMEM;
1831         goto out;
1832 }
1833