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_transport_hold(transport);
 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_transport_put(transport);
 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         /* This happens when the response arrives after the timer is triggered. */
 477         if (!asoc->strreset_chunk)
 478                 goto out_unlock;
 479
 480         error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
 481                            SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_RECONF),
 482                            asoc->state, asoc->ep, asoc,
 483                            transport, GFP_ATOMIC);
 484
 485         if (error)
 486                 sk->sk_err = -error;
 487
 488 out_unlock:
 489         bh_unlock_sock(sk);
 490         sctp_transport_put(transport);
 491 }
 492
 493 /* Inject a SACK Timeout event into the state machine.  */
 494 static void sctp_generate_sack_event(struct timer_list *t)
 495 {
 496         struct sctp_association *asoc =
 497                 from_timer(asoc, t, timers[SCTP_EVENT_TIMEOUT_SACK]);
 498
 499         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
 500 }
 501
 502 sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
 503         [SCTP_EVENT_TIMEOUT_NONE] =             NULL,
 504         [SCTP_EVENT_TIMEOUT_T1_COOKIE] =        sctp_generate_t1_cookie_event,
 505         [SCTP_EVENT_TIMEOUT_T1_INIT] =          sctp_generate_t1_init_event,
 506         [SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] =      sctp_generate_t2_shutdown_event,
 507         [SCTP_EVENT_TIMEOUT_T3_RTX] =           NULL,
 508         [SCTP_EVENT_TIMEOUT_T4_RTO] =           sctp_generate_t4_rto_event,
 509         [SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD] =
 510                                         sctp_generate_t5_shutdown_guard_event,
 511         [SCTP_EVENT_TIMEOUT_HEARTBEAT] =        NULL,
 512         [SCTP_EVENT_TIMEOUT_RECONF] =           NULL,
 513         [SCTP_EVENT_TIMEOUT_SACK] =             sctp_generate_sack_event,
 514         [SCTP_EVENT_TIMEOUT_AUTOCLOSE] =        sctp_generate_autoclose_event,
 515 };
 516
 517
 518 /* RFC 2960 8.2 Path Failure Detection
 519  *
 520  * When its peer endpoint is multi-homed, an endpoint should keep a
 521  * error counter for each of the destination transport addresses of the
 522  * peer endpoint.
 523  *
 524  * Each time the T3-rtx timer expires on any address, or when a
 525  * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
 526  * the error counter of that destination address will be incremented.
 527  * When the value in the error counter exceeds the protocol parameter
 528  * 'Path.Max.Retrans' of that destination address, the endpoint should
 529  * mark the destination transport address as inactive, and a
 530  * notification SHOULD be sent to the upper layer.
 531  *
 532  */
 533 static void sctp_do_8_2_transport_strike(struct sctp_cmd_seq *commands,
 534                                          struct sctp_association *asoc,
 535                                          struct sctp_transport *transport,
 536                                          int is_hb)
 537 {
 538         struct net *net = sock_net(asoc->base.sk);
 539
 540         /* The check for association's overall error counter exceeding the
 541          * threshold is done in the state function.
 542          */
 543         /* We are here due to a timer expiration.  If the timer was
 544          * not a HEARTBEAT, then normal error tracking is done.
 545          * If the timer was a heartbeat, we only increment error counts
 546          * when we already have an outstanding HEARTBEAT that has not
 547          * been acknowledged.
 548          * Additionally, some tranport states inhibit error increments.
 549          */
 550         if (!is_hb) {
 551                 asoc->overall_error_count++;
 552                 if (transport->state != SCTP_INACTIVE)
 553                         transport->error_count++;
 554          } else if (transport->hb_sent) {
 555                 if (transport->state != SCTP_UNCONFIRMED)
 556                         asoc->overall_error_count++;
 557                 if (transport->state != SCTP_INACTIVE)
 558                         transport->error_count++;
 559         }
 560
 561         /* If the transport error count is greater than the pf_retrans
 562          * threshold, and less than pathmaxrtx, and if the current state
 563          * is SCTP_ACTIVE, then mark this transport as Partially Failed,
 564          * see SCTP Quick Failover Draft, section 5.1
 565          */
 566         if (net->sctp.pf_enable &&
 567            (transport->state == SCTP_ACTIVE) &&
 568            (transport->error_count < transport->pathmaxrxt) &&
 569            (transport->error_count > transport->pf_retrans)) {
 570
 571                 sctp_assoc_control_transport(asoc, transport,
 572                                              SCTP_TRANSPORT_PF,
 573                                              0);
 574
 575                 /* Update the hb timer to resend a heartbeat every rto */
 576                 sctp_transport_reset_hb_timer(transport);
 577         }
 578
 579         if (transport->state != SCTP_INACTIVE &&
 580             (transport->error_count > transport->pathmaxrxt)) {
 581                 pr_debug("%s: association:%p transport addr:%pISpc failed\n",
 582                          __func__, asoc, &transport->ipaddr.sa);
 583
 584                 sctp_assoc_control_transport(asoc, transport,
 585                                              SCTP_TRANSPORT_DOWN,
 586                                              SCTP_FAILED_THRESHOLD);
 587         }
 588
 589         /* E2) For the destination address for which the timer
 590          * expires, set RTO <- RTO * 2 ("back off the timer").  The
 591          * maximum value discussed in rule C7 above (RTO.max) may be
 592          * used to provide an upper bound to this doubling operation.
 593          *
 594          * Special Case:  the first HB doesn't trigger exponential backoff.
 595          * The first unacknowledged HB triggers it.  We do this with a flag
 596          * that indicates that we have an outstanding HB.
 597          */
 598         if (!is_hb || transport->hb_sent) {
 599                 transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
 600                 sctp_max_rto(asoc, transport);
 601         }
 602 }
 603
 604 /* Worker routine to handle INIT command failure.  */
 605 static void sctp_cmd_init_failed(struct sctp_cmd_seq *commands,
 606                                  struct sctp_association *asoc,
 607                                  unsigned int error)
 608 {
 609         struct sctp_ulpevent *event;
 610
 611         event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_CANT_STR_ASSOC,
 612                                                 (__u16)error, 0, 0, NULL,
 613                                                 GFP_ATOMIC);
 614
 615         if (event)
 616                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 617                                 SCTP_ULPEVENT(event));
 618
 619         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 620                         SCTP_STATE(SCTP_STATE_CLOSED));
 621
 622         /* SEND_FAILED sent later when cleaning up the association. */
 623         asoc->outqueue.error = error;
 624         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 625 }
 626
 627 /* Worker routine to handle SCTP_CMD_ASSOC_FAILED.  */
 628 static void sctp_cmd_assoc_failed(struct sctp_cmd_seq *commands,
 629                                   struct sctp_association *asoc,
 630                                   enum sctp_event event_type,
 631                                   union sctp_subtype subtype,
 632                                   struct sctp_chunk *chunk,
 633                                   unsigned int error)
 634 {
 635         struct sctp_ulpevent *event;
 636         struct sctp_chunk *abort;
 637
 638         /* Cancel any partial delivery in progress. */
 639         asoc->stream.si->abort_pd(&asoc->ulpq, GFP_ATOMIC);
 640
 641         if (event_type == SCTP_EVENT_T_CHUNK && subtype.chunk == SCTP_CID_ABORT)
 642                 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
 643                                                 (__u16)error, 0, 0, chunk,
 644                                                 GFP_ATOMIC);
 645         else
 646                 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
 647                                                 (__u16)error, 0, 0, NULL,
 648                                                 GFP_ATOMIC);
 649         if (event)
 650                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 651                                 SCTP_ULPEVENT(event));
 652
 653         if (asoc->overall_error_count >= asoc->max_retrans) {
 654                 abort = sctp_make_violation_max_retrans(asoc, chunk);
 655                 if (abort)
 656                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
 657                                         SCTP_CHUNK(abort));
 658         }
 659
 660         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 661                         SCTP_STATE(SCTP_STATE_CLOSED));
 662
 663         /* SEND_FAILED sent later when cleaning up the association. */
 664         asoc->outqueue.error = error;
 665         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 666 }
 667
 668 /* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
 669  * inside the cookie.  In reality, this is only used for INIT-ACK processing
 670  * since all other cases use "temporary" associations and can do all
 671  * their work in statefuns directly.
 672  */
 673 static int sctp_cmd_process_init(struct sctp_cmd_seq *commands,
 674                                  struct sctp_association *asoc,
 675                                  struct sctp_chunk *chunk,
 676                                  struct sctp_init_chunk *peer_init,
 677                                  gfp_t gfp)
 678 {
 679         int error;
 680
 681         /* We only process the init as a sideeffect in a single
 682          * case.   This is when we process the INIT-ACK.   If we
 683          * fail during INIT processing (due to malloc problems),
 684          * just return the error and stop processing the stack.
 685          */
 686         if (!sctp_process_init(asoc, chunk, sctp_source(chunk), peer_init, gfp))
 687                 error = -ENOMEM;
 688         else
 689                 error = 0;
 690
 691         return error;
 692 }
 693
 694 /* Helper function to break out starting up of heartbeat timers.  */
 695 static void sctp_cmd_hb_timers_start(struct sctp_cmd_seq *cmds,
 696                                      struct sctp_association *asoc)
 697 {
 698         struct sctp_transport *t;
 699
 700         /* Start a heartbeat timer for each transport on the association.
 701          * hold a reference on the transport to make sure none of
 702          * the needed data structures go away.
 703          */
 704         list_for_each_entry(t, &asoc->peer.transport_addr_list, transports)
 705                 sctp_transport_reset_hb_timer(t);
 706 }
 707
 708 static void sctp_cmd_hb_timers_stop(struct sctp_cmd_seq *cmds,
 709                                     struct sctp_association *asoc)
 710 {
 711         struct sctp_transport *t;
 712
 713         /* Stop all heartbeat timers. */
 714
 715         list_for_each_entry(t, &asoc->peer.transport_addr_list,
 716                         transports) {
 717                 if (del_timer(&t->hb_timer))
 718                         sctp_transport_put(t);
 719         }
 720 }
 721
 722 /* Helper function to stop any pending T3-RTX timers */
 723 static void sctp_cmd_t3_rtx_timers_stop(struct sctp_cmd_seq *cmds,
 724                                         struct sctp_association *asoc)
 725 {
 726         struct sctp_transport *t;
 727
 728         list_for_each_entry(t, &asoc->peer.transport_addr_list,
 729                         transports) {
 730                 if (del_timer(&t->T3_rtx_timer))
 731                         sctp_transport_put(t);
 732         }
 733 }
 734
 735
 736 /* Helper function to handle the reception of an HEARTBEAT ACK.  */
 737 static void sctp_cmd_transport_on(struct sctp_cmd_seq *cmds,
 738                                   struct sctp_association *asoc,
 739                                   struct sctp_transport *t,
 740                                   struct sctp_chunk *chunk)
 741 {
 742         struct sctp_sender_hb_info *hbinfo;
 743         int was_unconfirmed = 0;
 744
 745         /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
 746          * HEARTBEAT should clear the error counter of the destination
 747          * transport address to which the HEARTBEAT was sent.
 748          */
 749         t->error_count = 0;
 750
 751         /*
 752          * Although RFC4960 specifies that the overall error count must
 753          * be cleared when a HEARTBEAT ACK is received, we make an
 754          * exception while in SHUTDOWN PENDING. If the peer keeps its
 755          * window shut forever, we may never be able to transmit our
 756          * outstanding data and rely on the retransmission limit be reached
 757          * to shutdown the association.
 758          */
 759         if (t->asoc->state < SCTP_STATE_SHUTDOWN_PENDING)
 760                 t->asoc->overall_error_count = 0;
 761
 762         /* Clear the hb_sent flag to signal that we had a good
 763          * acknowledgement.
 764          */
 765         t->hb_sent = 0;
 766
 767         /* Mark the destination transport address as active if it is not so
 768          * marked.
 769          */
 770         if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED)) {
 771                 was_unconfirmed = 1;
 772                 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
 773                                              SCTP_HEARTBEAT_SUCCESS);
 774         }
 775
 776         if (t->state == SCTP_PF)
 777                 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
 778                                              SCTP_HEARTBEAT_SUCCESS);
 779
 780         /* HB-ACK was received for a the proper HB.  Consider this
 781          * forward progress.
 782          */
 783         if (t->dst)
 784                 sctp_transport_dst_confirm(t);
 785
 786         /* The receiver of the HEARTBEAT ACK should also perform an
 787          * RTT measurement for that destination transport address
 788          * using the time value carried in the HEARTBEAT ACK chunk.
 789          * If the transport's rto_pending variable has been cleared,
 790          * it was most likely due to a retransmit.  However, we want
 791          * to re-enable it to properly update the rto.
 792          */
 793         if (t->rto_pending == 0)
 794                 t->rto_pending = 1;
 795
 796         hbinfo = (struct sctp_sender_hb_info *)chunk->skb->data;
 797         sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
 798
 799         /* Update the heartbeat timer.  */
 800         sctp_transport_reset_hb_timer(t);
 801
 802         if (was_unconfirmed && asoc->peer.transport_count == 1)
 803                 sctp_transport_immediate_rtx(t);
 804 }
 805
 806
 807 /* Helper function to process the process SACK command.  */
 808 static int sctp_cmd_process_sack(struct sctp_cmd_seq *cmds,
 809                                  struct sctp_association *asoc,
 810                                  struct sctp_chunk *chunk)
 811 {
 812         int err = 0;
 813
 814         if (sctp_outq_sack(&asoc->outqueue, chunk)) {
 815                 struct net *net = sock_net(asoc->base.sk);
 816
 817                 /* There are no more TSNs awaiting SACK.  */
 818                 err = sctp_do_sm(net, SCTP_EVENT_T_OTHER,
 819                                  SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
 820                                  asoc->state, asoc->ep, asoc, NULL,
 821                                  GFP_ATOMIC);
 822         }
 823
 824         return err;
 825 }
 826
 827 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
 828  * the transport for a shutdown chunk.
 829  */
 830 static void sctp_cmd_setup_t2(struct sctp_cmd_seq *cmds,
 831                               struct sctp_association *asoc,
 832                               struct sctp_chunk *chunk)
 833 {
 834         struct sctp_transport *t;
 835
 836         if (chunk->transport)
 837                 t = chunk->transport;
 838         else {
 839                 t = sctp_assoc_choose_alter_transport(asoc,
 840                                               asoc->shutdown_last_sent_to);
 841                 chunk->transport = t;
 842         }
 843         asoc->shutdown_last_sent_to = t;
 844         asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
 845 }
 846
 847 static void sctp_cmd_assoc_update(struct sctp_cmd_seq *cmds,
 848                                   struct sctp_association *asoc,
 849                                   struct sctp_association *new)
 850 {
 851         struct net *net = sock_net(asoc->base.sk);
 852         struct sctp_chunk *abort;
 853
 854         if (!sctp_assoc_update(asoc, new))
 855                 return;
 856
 857         abort = sctp_make_abort(asoc, NULL, sizeof(struct sctp_errhdr));
 858         if (abort) {
 859                 sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0);
 860                 sctp_add_cmd_sf(cmds, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
 861         }
 862         sctp_add_cmd_sf(cmds, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNABORTED));
 863         sctp_add_cmd_sf(cmds, SCTP_CMD_ASSOC_FAILED,
 864                         SCTP_PERR(SCTP_ERROR_RSRC_LOW));
 865         SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
 866         SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
 867 }
 868
 869 /* Helper function to change the state of an association. */
 870 static void sctp_cmd_new_state(struct sctp_cmd_seq *cmds,
 871                                struct sctp_association *asoc,
 872                                enum sctp_state state)
 873 {
 874         struct sock *sk = asoc->base.sk;
 875
 876         asoc->state = state;
 877
 878         pr_debug("%s: asoc:%p[%s]\n", __func__, asoc, sctp_state_tbl[state]);
 879
 880         if (sctp_style(sk, TCP)) {
 881                 /* Change the sk->sk_state of a TCP-style socket that has
 882                  * successfully completed a connect() call.
 883                  */
 884                 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
 885                         inet_sk_set_state(sk, SCTP_SS_ESTABLISHED);
 886
 887                 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
 888                 if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
 889                     sctp_sstate(sk, ESTABLISHED)) {
 890                         inet_sk_set_state(sk, SCTP_SS_CLOSING);
 891                         sk->sk_shutdown |= RCV_SHUTDOWN;
 892                 }
 893         }
 894
 895         if (sctp_state(asoc, COOKIE_WAIT)) {
 896                 /* Reset init timeouts since they may have been
 897                  * increased due to timer expirations.
 898                  */
 899                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
 900                                                 asoc->rto_initial;
 901                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
 902                                                 asoc->rto_initial;
 903         }
 904
 905         if (sctp_state(asoc, ESTABLISHED)) {
 906                 kfree(asoc->peer.cookie);
 907                 asoc->peer.cookie = NULL;
 908         }
 909
 910         if (sctp_state(asoc, ESTABLISHED) ||
 911             sctp_state(asoc, CLOSED) ||
 912             sctp_state(asoc, SHUTDOWN_RECEIVED)) {
 913                 /* Wake up any processes waiting in the asoc's wait queue in
 914                  * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
 915                  */
 916                 if (waitqueue_active(&asoc->wait))
 917                         wake_up_interruptible(&asoc->wait);
 918
 919                 /* Wake up any processes waiting in the sk's sleep queue of
 920                  * a TCP-style or UDP-style peeled-off socket in
 921                  * sctp_wait_for_accept() or sctp_wait_for_packet().
 922                  * For a UDP-style socket, the waiters are woken up by the
 923                  * notifications.
 924                  */
 925                 if (!sctp_style(sk, UDP))
 926                         sk->sk_state_change(sk);
 927         }
 928
 929         if (sctp_state(asoc, SHUTDOWN_PENDING) &&
 930             !sctp_outq_is_empty(&asoc->outqueue))
 931                 sctp_outq_uncork(&asoc->outqueue, GFP_ATOMIC);
 932 }
 933
 934 /* Helper function to delete an association. */
 935 static void sctp_cmd_delete_tcb(struct sctp_cmd_seq *cmds,
 936                                 struct sctp_association *asoc)
 937 {
 938         struct sock *sk = asoc->base.sk;
 939
 940         /* If it is a non-temporary association belonging to a TCP-style
 941          * listening socket that is not closed, do not free it so that accept()
 942          * can pick it up later.
 943          */
 944         if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
 945             (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
 946                 return;
 947
 948         sctp_association_free(asoc);
 949 }
 950
 951 /*
 952  * ADDIP Section 4.1 ASCONF Chunk Procedures
 953  * A4) Start a T-4 RTO timer, using the RTO value of the selected
 954  * destination address (we use active path instead of primary path just
 955  * because primary path may be inactive.
 956  */
 957 static void sctp_cmd_setup_t4(struct sctp_cmd_seq *cmds,
 958                               struct sctp_association *asoc,
 959                               struct sctp_chunk *chunk)
 960 {
 961         struct sctp_transport *t;
 962
 963         t = sctp_assoc_choose_alter_transport(asoc, chunk->transport);
 964         asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
 965         chunk->transport = t;
 966 }
 967
 968 /* Process an incoming Operation Error Chunk. */
 969 static void sctp_cmd_process_operr(struct sctp_cmd_seq *cmds,
 970                                    struct sctp_association *asoc,
 971                                    struct sctp_chunk *chunk)
 972 {
 973         struct sctp_errhdr *err_hdr;
 974         struct sctp_ulpevent *ev;
 975
 976         while (chunk->chunk_end > chunk->skb->data) {
 977                 err_hdr = (struct sctp_errhdr *)(chunk->skb->data);
 978
 979                 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
 980                                                      GFP_ATOMIC);
 981                 if (!ev)
 982                         return;
 983
 984                 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
 985
 986                 switch (err_hdr->cause) {
 987                 case SCTP_ERROR_UNKNOWN_CHUNK:
 988                 {
 989                         struct sctp_chunkhdr *unk_chunk_hdr;
 990
 991                         unk_chunk_hdr = (struct sctp_chunkhdr *)
 992                                                         err_hdr->variable;
 993                         switch (unk_chunk_hdr->type) {
 994                         /* ADDIP 4.1 A9) If the peer responds to an ASCONF with
 995                          * an ERROR chunk reporting that it did not recognized
 996                          * the ASCONF chunk type, the sender of the ASCONF MUST
 997                          * NOT send any further ASCONF chunks and MUST stop its
 998                          * T-4 timer.
 999                          */
1000                         case SCTP_CID_ASCONF:
1001                                 if (asoc->peer.asconf_capable == 0)
1002                                         break;
1003
1004                                 asoc->peer.asconf_capable = 0;
1005                                 sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
1006                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
1007                                 break;
1008                         default:
1009                                 break;
1010                         }
1011                         break;
1012                 }
1013                 default:
1014                         break;
1015                 }
1016         }
1017 }
1018
1019 /* Helper function to remove the association non-primary peer
1020  * transports.
1021  */
1022 static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
1023 {
1024         struct sctp_transport *t;
1025         struct list_head *temp;
1026         struct list_head *pos;
1027
1028         list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
1029                 t = list_entry(pos, struct sctp_transport, transports);
1030                 if (!sctp_cmp_addr_exact(&t->ipaddr,
1031                                          &asoc->peer.primary_addr)) {
1032                         sctp_assoc_rm_peer(asoc, t);
1033                 }
1034         }
1035 }
1036
1037 /* Helper function to set sk_err on a 1-1 style socket. */
1038 static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
1039 {
1040         struct sock *sk = asoc->base.sk;
1041
1042         if (!sctp_style(sk, UDP))
1043                 sk->sk_err = error;
1044 }
1045
1046 /* Helper function to generate an association change event */
1047 static void sctp_cmd_assoc_change(struct sctp_cmd_seq *commands,
1048                                   struct sctp_association *asoc,
1049                                   u8 state)
1050 {
1051         struct sctp_ulpevent *ev;
1052
1053         ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0,
1054                                             asoc->c.sinit_num_ostreams,
1055                                             asoc->c.sinit_max_instreams,
1056                                             NULL, GFP_ATOMIC);
1057         if (ev)
1058                 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
1059 }
1060
1061 static void sctp_cmd_peer_no_auth(struct sctp_cmd_seq *commands,
1062                                   struct sctp_association *asoc)
1063 {
1064         struct sctp_ulpevent *ev;
1065
1066         ev = sctp_ulpevent_make_authkey(asoc, 0, SCTP_AUTH_NO_AUTH, GFP_ATOMIC);
1067         if (ev)
1068                 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
1069 }
1070
1071 /* Helper function to generate an adaptation indication event */
1072 static void sctp_cmd_adaptation_ind(struct sctp_cmd_seq *commands,
1073                                     struct sctp_association *asoc)
1074 {
1075         struct sctp_ulpevent *ev;
1076
1077         ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
1078
1079         if (ev)
1080                 asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
1081 }
1082
1083
1084 static void sctp_cmd_t1_timer_update(struct sctp_association *asoc,
1085                                      enum sctp_event_timeout timer,
1086                                      char *name)
1087 {
1088         struct sctp_transport *t;
1089
1090         t = asoc->init_last_sent_to;
1091         asoc->init_err_counter++;
1092
1093         if (t->init_sent_count > (asoc->init_cycle + 1)) {
1094                 asoc->timeouts[timer] *= 2;
1095                 if (asoc->timeouts[timer] > asoc->max_init_timeo) {
1096                         asoc->timeouts[timer] = asoc->max_init_timeo;
1097                 }
1098                 asoc->init_cycle++;
1099
1100                 pr_debug("%s: T1[%s] timeout adjustment init_err_counter:%d"
1101                          " cycle:%d timeout:%ld\n", __func__, name,
1102                          asoc->init_err_counter, asoc->init_cycle,
1103                          asoc->timeouts[timer]);
1104         }
1105
1106 }
1107
1108 /* Send the whole message, chunk by chunk, to the outqueue.
1109  * This way the whole message is queued up and bundling if
1110  * encouraged for small fragments.
1111  */
1112 static void sctp_cmd_send_msg(struct sctp_association *asoc,
1113                               struct sctp_datamsg *msg, gfp_t gfp)
1114 {
1115         struct sctp_chunk *chunk;
1116
1117         list_for_each_entry(chunk, &msg->chunks, frag_list)
1118                 sctp_outq_tail(&asoc->outqueue, chunk, gfp);
1119
1120         asoc->outqueue.sched->enqueue(&asoc->outqueue, msg);
1121 }
1122
1123
1124 /* These three macros allow us to pull the debugging code out of the
1125  * main flow of sctp_do_sm() to keep attention focused on the real
1126  * functionality there.
1127  */
1128 #define debug_pre_sfn() \
1129         pr_debug("%s[pre-fn]: ep:%p, %s, %s, asoc:%p[%s], %s\n", __func__, \
1130                  ep, sctp_evttype_tbl[event_type], (*debug_fn)(subtype),   \
1131                  asoc, sctp_state_tbl[state], state_fn->name)
1132
1133 #define debug_post_sfn() \
1134         pr_debug("%s[post-fn]: asoc:%p, status:%s\n", __func__, asoc, \
1135                  sctp_status_tbl[status])
1136
1137 #define debug_post_sfx() \
1138         pr_debug("%s[post-sfx]: error:%d, asoc:%p[%s]\n", __func__, error, \
1139                  asoc, sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
1140                  sctp_assoc2id(asoc))) ? asoc->state : SCTP_STATE_CLOSED])
1141
1142 /*
1143  * This is the master state machine processing function.
1144  *
1145  * If you want to understand all of lksctp, this is a
1146  * good place to start.
1147  */
1148 int sctp_do_sm(struct net *net, enum sctp_event event_type,
1149                union sctp_subtype subtype, enum sctp_state state,
1150                struct sctp_endpoint *ep, struct sctp_association *asoc,
1151                void *event_arg, gfp_t gfp)
1152 {
1153         typedef const char *(printfn_t)(union sctp_subtype);
1154         static printfn_t *table[] = {
1155                 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
1156         };
1157         printfn_t *debug_fn  __attribute__ ((unused)) = table[event_type];
1158         const struct sctp_sm_table_entry *state_fn;
1159         struct sctp_cmd_seq commands;
1160         enum sctp_disposition status;
1161         int error = 0;
1162
1163         /* Look up the state function, run it, and then process the
1164          * side effects.  These three steps are the heart of lksctp.
1165          */
1166         state_fn = sctp_sm_lookup_event(net, event_type, state, subtype);
1167
1168         sctp_init_cmd_seq(&commands);
1169
1170         debug_pre_sfn();
1171         status = state_fn->fn(net, ep, asoc, subtype, event_arg, &commands);
1172         debug_post_sfn();
1173
1174         error = sctp_side_effects(event_type, subtype, state,
1175                                   ep, &asoc, event_arg, status,
1176                                   &commands, gfp);
1177         debug_post_sfx();
1178
1179         return error;
1180 }
1181
1182 /*****************************************************************
1183  * This the master state function side effect processing function.
1184  *****************************************************************/
1185 static int sctp_side_effects(enum sctp_event event_type,
1186                              union sctp_subtype subtype,
1187                              enum sctp_state state,
1188                              struct sctp_endpoint *ep,
1189                              struct sctp_association **asoc,
1190                              void *event_arg,
1191                              enum sctp_disposition status,
1192                              struct sctp_cmd_seq *commands,
1193                              gfp_t gfp)
1194 {
1195         int error;
1196
1197         /* FIXME - Most of the dispositions left today would be categorized
1198          * as "exceptional" dispositions.  For those dispositions, it
1199          * may not be proper to run through any of the commands at all.
1200          * For example, the command interpreter might be run only with
1201          * disposition SCTP_DISPOSITION_CONSUME.
1202          */
1203         if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
1204                                                ep, *asoc,
1205                                                event_arg, status,
1206                                                commands, gfp)))
1207                 goto bail;
1208
1209         switch (status) {
1210         case SCTP_DISPOSITION_DISCARD:
1211                 pr_debug("%s: ignored sctp protocol event - state:%d, "
1212                          "event_type:%d, event_id:%d\n", __func__, state,
1213                          event_type, subtype.chunk);
1214                 break;
1215
1216         case SCTP_DISPOSITION_NOMEM:
1217                 /* We ran out of memory, so we need to discard this
1218                  * packet.
1219                  */
1220                 /* BUG--we should now recover some memory, probably by
1221                  * reneging...
1222                  */
1223                 error = -ENOMEM;
1224                 break;
1225
1226         case SCTP_DISPOSITION_DELETE_TCB:
1227         case SCTP_DISPOSITION_ABORT:
1228                 /* This should now be a command. */
1229                 *asoc = NULL;
1230                 break;
1231
1232         case SCTP_DISPOSITION_CONSUME:
1233                 /*
1234                  * We should no longer have much work to do here as the
1235                  * real work has been done as explicit commands above.
1236                  */
1237                 break;
1238
1239         case SCTP_DISPOSITION_VIOLATION:
1240                 net_err_ratelimited("protocol violation state %d chunkid %d\n",
1241                                     state, subtype.chunk);
1242                 break;
1243
1244         case SCTP_DISPOSITION_NOT_IMPL:
1245                 pr_warn("unimplemented feature in state %d, event_type %d, event_id %d\n",
1246                         state, event_type, subtype.chunk);
1247                 break;
1248
1249         case SCTP_DISPOSITION_BUG:
1250                 pr_err("bug in state %d, event_type %d, event_id %d\n",
1251                        state, event_type, subtype.chunk);
1252                 BUG();
1253                 break;
1254
1255         default:
1256                 pr_err("impossible disposition %d in state %d, event_type %d, event_id %d\n",
1257                        status, state, event_type, subtype.chunk);
1258                 BUG();
1259                 break;
1260         }
1261
1262 bail:
1263         return error;
1264 }
1265
1266 /********************************************************************
1267  * 2nd Level Abstractions
1268  ********************************************************************/
1269
1270 /* This is the side-effect interpreter.  */
1271 static int sctp_cmd_interpreter(enum sctp_event event_type,
1272                                 union sctp_subtype subtype,
1273                                 enum sctp_state state,
1274                                 struct sctp_endpoint *ep,
1275                                 struct sctp_association *asoc,
1276                                 void *event_arg,
1277                                 enum sctp_disposition status,
1278                                 struct sctp_cmd_seq *commands,
1279                                 gfp_t gfp)
1280 {
1281         struct sctp_sock *sp = sctp_sk(ep->base.sk);
1282         struct sctp_chunk *chunk = NULL, *new_obj;
1283         struct sctp_packet *packet;
1284         struct sctp_sackhdr sackh;
1285         struct timer_list *timer;
1286         struct sctp_transport *t;
1287         unsigned long timeout;
1288         struct sctp_cmd *cmd;
1289         int local_cork = 0;
1290         int error = 0;
1291         int force;
1292
1293         if (SCTP_EVENT_T_TIMEOUT != event_type)
1294                 chunk = event_arg;
1295
1296         /* Note:  This whole file is a huge candidate for rework.
1297          * For example, each command could either have its own handler, so
1298          * the loop would look like:
1299          *     while (cmds)
1300          *         cmd->handle(x, y, z)
1301          * --jgrimm
1302          */
1303         while (NULL != (cmd = sctp_next_cmd(commands))) {
1304                 switch (cmd->verb) {
1305                 case SCTP_CMD_NOP:
1306                         /* Do nothing. */
1307                         break;
1308
1309                 case SCTP_CMD_NEW_ASOC:
1310                         /* Register a new association.  */
1311                         if (local_cork) {
1312                                 sctp_outq_uncork(&asoc->outqueue, gfp);
1313                                 local_cork = 0;
1314                         }
1315
1316                         /* Register with the endpoint.  */
1317                         asoc = cmd->obj.asoc;
1318                         BUG_ON(asoc->peer.primary_path == NULL);
1319                         sctp_endpoint_add_asoc(ep, asoc);
1320                         break;
1321
1322                 case SCTP_CMD_UPDATE_ASSOC:
1323                        sctp_cmd_assoc_update(commands, asoc, cmd->obj.asoc);
1324                        break;
1325
1326                 case SCTP_CMD_PURGE_OUTQUEUE:
1327                        sctp_outq_teardown(&asoc->outqueue);
1328                        break;
1329
1330                 case SCTP_CMD_DELETE_TCB:
1331                         if (local_cork) {
1332                                 sctp_outq_uncork(&asoc->outqueue, gfp);
1333                                 local_cork = 0;
1334                         }
1335                         /* Delete the current association.  */
1336                         sctp_cmd_delete_tcb(commands, asoc);
1337                         asoc = NULL;
1338                         break;
1339
1340                 case SCTP_CMD_NEW_STATE:
1341                         /* Enter a new state.  */
1342                         sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1343                         break;
1344
1345                 case SCTP_CMD_REPORT_TSN:
1346                         /* Record the arrival of a TSN.  */
1347                         error = sctp_tsnmap_mark(&asoc->peer.tsn_map,
1348                                                  cmd->obj.u32, NULL);
1349                         break;
1350
1351                 case SCTP_CMD_REPORT_FWDTSN:
1352                         asoc->stream.si->report_ftsn(&asoc->ulpq, cmd->obj.u32);
1353                         break;
1354
1355                 case SCTP_CMD_PROCESS_FWDTSN:
1356                         asoc->stream.si->handle_ftsn(&asoc->ulpq,
1357                                                      cmd->obj.chunk);
1358                         break;
1359
1360                 case SCTP_CMD_GEN_SACK:
1361                         /* Generate a Selective ACK.
1362                          * The argument tells us whether to just count
1363                          * the packet and MAYBE generate a SACK, or
1364                          * force a SACK out.
1365                          */
1366                         force = cmd->obj.i32;
1367                         error = sctp_gen_sack(asoc, force, commands);
1368                         break;
1369
1370                 case SCTP_CMD_PROCESS_SACK:
1371                         /* Process an inbound SACK.  */
1372                         error = sctp_cmd_process_sack(commands, asoc,
1373                                                       cmd->obj.chunk);
1374                         break;
1375
1376                 case SCTP_CMD_GEN_INIT_ACK:
1377                         /* Generate an INIT ACK chunk.  */
1378                         new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1379                                                      0);
1380                         if (!new_obj) {
1381                                 error = -ENOMEM;
1382                                 break;
1383                         }
1384
1385                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1386                                         SCTP_CHUNK(new_obj));
1387                         break;
1388
1389                 case SCTP_CMD_PEER_INIT:
1390                         /* Process a unified INIT from the peer.
1391                          * Note: Only used during INIT-ACK processing.  If
1392                          * there is an error just return to the outter
1393                          * layer which will bail.
1394                          */
1395                         error = sctp_cmd_process_init(commands, asoc, chunk,
1396                                                       cmd->obj.init, gfp);
1397                         break;
1398
1399                 case SCTP_CMD_GEN_COOKIE_ECHO:
1400                         /* Generate a COOKIE ECHO chunk.  */
1401                         new_obj = sctp_make_cookie_echo(asoc, chunk);
1402                         if (!new_obj) {
1403                                 if (cmd->obj.chunk)
1404                                         sctp_chunk_free(cmd->obj.chunk);
1405                                 error = -ENOMEM;
1406                                 break;
1407                         }
1408                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1409                                         SCTP_CHUNK(new_obj));
1410
1411                         /* If there is an ERROR chunk to be sent along with
1412                          * the COOKIE_ECHO, send it, too.
1413                          */
1414                         if (cmd->obj.chunk)
1415                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1416                                                 SCTP_CHUNK(cmd->obj.chunk));
1417
1418                         if (new_obj->transport) {
1419                                 new_obj->transport->init_sent_count++;
1420                                 asoc->init_last_sent_to = new_obj->transport;
1421                         }
1422
1423                         /* FIXME - Eventually come up with a cleaner way to
1424                          * enabling COOKIE-ECHO + DATA bundling during
1425                          * multihoming stale cookie scenarios, the following
1426                          * command plays with asoc->peer.retran_path to
1427                          * avoid the problem of sending the COOKIE-ECHO and
1428                          * DATA in different paths, which could result
1429                          * in the association being ABORTed if the DATA chunk
1430                          * is processed first by the server.  Checking the
1431                          * init error counter simply causes this command
1432                          * to be executed only during failed attempts of
1433                          * association establishment.
1434                          */
1435                         if ((asoc->peer.retran_path !=
1436                              asoc->peer.primary_path) &&
1437                             (asoc->init_err_counter > 0)) {
1438                                 sctp_add_cmd_sf(commands,
1439                                                 SCTP_CMD_FORCE_PRIM_RETRAN,
1440                                                 SCTP_NULL());
1441                         }
1442
1443                         break;
1444
1445                 case SCTP_CMD_GEN_SHUTDOWN:
1446                         /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1447                          * Reset error counts.
1448                          */
1449                         asoc->overall_error_count = 0;
1450
1451                         /* Generate a SHUTDOWN chunk.  */
1452                         new_obj = sctp_make_shutdown(asoc, chunk);
1453                         if (!new_obj) {
1454                                 error = -ENOMEM;
1455                                 break;
1456                         }
1457                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1458                                         SCTP_CHUNK(new_obj));
1459                         break;
1460
1461                 case SCTP_CMD_CHUNK_ULP:
1462                         /* Send a chunk to the sockets layer.  */
1463                         pr_debug("%s: sm_sideff: chunk_up:%p, ulpq:%p\n",
1464                                  __func__, cmd->obj.chunk, &asoc->ulpq);
1465
1466                         asoc->stream.si->ulpevent_data(&asoc->ulpq,
1467                                                        cmd->obj.chunk,
1468                                                        GFP_ATOMIC);
1469                         break;
1470
1471                 case SCTP_CMD_EVENT_ULP:
1472                         /* Send a notification to the sockets layer.  */
1473                         pr_debug("%s: sm_sideff: event_up:%p, ulpq:%p\n",
1474                                  __func__, cmd->obj.ulpevent, &asoc->ulpq);
1475
1476                         asoc->stream.si->enqueue_event(&asoc->ulpq,
1477                                                        cmd->obj.ulpevent);
1478                         break;
1479
1480                 case SCTP_CMD_REPLY:
1481                         /* If an caller has not already corked, do cork. */
1482                         if (!asoc->outqueue.cork) {
1483                                 sctp_outq_cork(&asoc->outqueue);
1484                                 local_cork = 1;
1485                         }
1486                         /* Send a chunk to our peer.  */
1487                         sctp_outq_tail(&asoc->outqueue, cmd->obj.chunk, gfp);
1488                         break;
1489
1490                 case SCTP_CMD_SEND_PKT:
1491                         /* Send a full packet to our peer.  */
1492                         packet = cmd->obj.packet;
1493                         sctp_packet_transmit(packet, gfp);
1494                         sctp_ootb_pkt_free(packet);
1495                         break;
1496
1497                 case SCTP_CMD_T1_RETRAN:
1498                         /* Mark a transport for retransmission.  */
1499                         sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1500                                         SCTP_RTXR_T1_RTX);
1501                         break;
1502
1503                 case SCTP_CMD_RETRAN:
1504                         /* Mark a transport for retransmission.  */
1505                         sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1506                                         SCTP_RTXR_T3_RTX);
1507                         break;
1508
1509                 case SCTP_CMD_ECN_CE:
1510                         /* Do delayed CE processing.   */
1511                         sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1512                         break;
1513
1514                 case SCTP_CMD_ECN_ECNE:
1515                         /* Do delayed ECNE processing. */
1516                         new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1517                                                         chunk);
1518                         if (new_obj)
1519                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1520                                                 SCTP_CHUNK(new_obj));
1521                         break;
1522
1523                 case SCTP_CMD_ECN_CWR:
1524                         /* Do delayed CWR processing.  */
1525                         sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1526                         break;
1527
1528                 case SCTP_CMD_SETUP_T2:
1529                         sctp_cmd_setup_t2(commands, asoc, cmd->obj.chunk);
1530                         break;
1531
1532                 case SCTP_CMD_TIMER_START_ONCE:
1533                         timer = &asoc->timers[cmd->obj.to];
1534
1535                         if (timer_pending(timer))
1536                                 break;
1537                         /* fall through */
1538
1539                 case SCTP_CMD_TIMER_START:
1540                         timer = &asoc->timers[cmd->obj.to];
1541                         timeout = asoc->timeouts[cmd->obj.to];
1542                         BUG_ON(!timeout);
1543
1544                         /*
1545                          * SCTP has a hard time with timer starts.  Because we process
1546                          * timer starts as side effects, it can be hard to tell if we
1547                          * have already started a timer or not, which leads to BUG
1548                          * halts when we call add_timer. So here, instead of just starting
1549                          * a timer, if the timer is already started, and just mod
1550                          * the timer with the shorter of the two expiration times
1551                          */
1552                         if (!timer_pending(timer))
1553                                 sctp_association_hold(asoc);
1554                         timer_reduce(timer, jiffies + timeout);
1555                         break;
1556
1557                 case SCTP_CMD_TIMER_RESTART:
1558                         timer = &asoc->timers[cmd->obj.to];
1559                         timeout = asoc->timeouts[cmd->obj.to];
1560                         if (!mod_timer(timer, jiffies + timeout))
1561                                 sctp_association_hold(asoc);
1562                         break;
1563
1564                 case SCTP_CMD_TIMER_STOP:
1565                         timer = &asoc->timers[cmd->obj.to];
1566                         if (del_timer(timer))
1567                                 sctp_association_put(asoc);
1568                         break;
1569
1570                 case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1571                         chunk = cmd->obj.chunk;
1572                         t = sctp_assoc_choose_alter_transport(asoc,
1573                                                 asoc->init_last_sent_to);
1574                         asoc->init_last_sent_to = t;
1575                         chunk->transport = t;
1576                         t->init_sent_count++;
1577                         /* Set the new transport as primary */
1578                         sctp_assoc_set_primary(asoc, t);
1579                         break;
1580
1581                 case SCTP_CMD_INIT_RESTART:
1582                         /* Do the needed accounting and updates
1583                          * associated with restarting an initialization
1584                          * timer. Only multiply the timeout by two if
1585                          * all transports have been tried at the current
1586                          * timeout.
1587                          */
1588                         sctp_cmd_t1_timer_update(asoc,
1589                                                 SCTP_EVENT_TIMEOUT_T1_INIT,
1590                                                 "INIT");
1591
1592                         sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1593                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1594                         break;
1595
1596                 case SCTP_CMD_COOKIEECHO_RESTART:
1597                         /* Do the needed accounting and updates
1598                          * associated with restarting an initialization
1599                          * timer. Only multiply the timeout by two if
1600                          * all transports have been tried at the current
1601                          * timeout.
1602                          */
1603                         sctp_cmd_t1_timer_update(asoc,
1604                                                 SCTP_EVENT_TIMEOUT_T1_COOKIE,
1605                                                 "COOKIE");
1606
1607                         /* If we've sent any data bundled with
1608                          * COOKIE-ECHO we need to resend.
1609                          */
1610                         list_for_each_entry(t, &asoc->peer.transport_addr_list,
1611                                         transports) {
1612                                 sctp_retransmit_mark(&asoc->outqueue, t,
1613                                             SCTP_RTXR_T1_RTX);
1614                         }
1615
1616                         sctp_add_cmd_sf(commands,
1617                                         SCTP_CMD_TIMER_RESTART,
1618                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1619                         break;
1620
1621                 case SCTP_CMD_INIT_FAILED:
1622                         sctp_cmd_init_failed(commands, asoc, cmd->obj.u16);
1623                         break;
1624
1625                 case SCTP_CMD_ASSOC_FAILED:
1626                         sctp_cmd_assoc_failed(commands, asoc, event_type,
1627                                               subtype, chunk, cmd->obj.u16);
1628                         break;
1629
1630                 case SCTP_CMD_INIT_COUNTER_INC:
1631                         asoc->init_err_counter++;
1632                         break;
1633
1634                 case SCTP_CMD_INIT_COUNTER_RESET:
1635                         asoc->init_err_counter = 0;
1636                         asoc->init_cycle = 0;
1637                         list_for_each_entry(t, &asoc->peer.transport_addr_list,
1638                                             transports) {
1639                                 t->init_sent_count = 0;
1640                         }
1641                         break;
1642
1643                 case SCTP_CMD_REPORT_DUP:
1644                         sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1645                                              cmd->obj.u32);
1646                         break;
1647
1648                 case SCTP_CMD_REPORT_BAD_TAG:
1649                         pr_debug("%s: vtag mismatch!\n", __func__);
1650                         break;
1651
1652                 case SCTP_CMD_STRIKE:
1653                         /* Mark one strike against a transport.  */
1654                         sctp_do_8_2_transport_strike(commands, asoc,
1655                                                     cmd->obj.transport, 0);
1656                         break;
1657
1658                 case SCTP_CMD_TRANSPORT_IDLE:
1659                         t = cmd->obj.transport;
1660                         sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
1661                         break;
1662
1663                 case SCTP_CMD_TRANSPORT_HB_SENT:
1664                         t = cmd->obj.transport;
1665                         sctp_do_8_2_transport_strike(commands, asoc,
1666                                                      t, 1);
1667                         t->hb_sent = 1;
1668                         break;
1669
1670                 case SCTP_CMD_TRANSPORT_ON:
1671                         t = cmd->obj.transport;
1672                         sctp_cmd_transport_on(commands, asoc, t, chunk);
1673                         break;
1674
1675                 case SCTP_CMD_HB_TIMERS_START:
1676                         sctp_cmd_hb_timers_start(commands, asoc);
1677                         break;
1678
1679                 case SCTP_CMD_HB_TIMER_UPDATE:
1680                         t = cmd->obj.transport;
1681                         sctp_transport_reset_hb_timer(t);
1682                         break;
1683
1684                 case SCTP_CMD_HB_TIMERS_STOP:
1685                         sctp_cmd_hb_timers_stop(commands, asoc);
1686                         break;
1687
1688                 case SCTP_CMD_REPORT_ERROR:
1689                         error = cmd->obj.error;
1690                         break;
1691
1692                 case SCTP_CMD_PROCESS_CTSN:
1693                         /* Dummy up a SACK for processing. */
1694                         sackh.cum_tsn_ack = cmd->obj.be32;
1695                         sackh.a_rwnd = htonl(asoc->peer.rwnd +
1696                                              asoc->outqueue.outstanding_bytes);
1697                         sackh.num_gap_ack_blocks = 0;
1698                         sackh.num_dup_tsns = 0;
1699                         chunk->subh.sack_hdr = &sackh;
1700                         sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1701                                         SCTP_CHUNK(chunk));
1702                         break;
1703
1704                 case SCTP_CMD_DISCARD_PACKET:
1705                         /* We need to discard the whole packet.
1706                          * Uncork the queue since there might be
1707                          * responses pending
1708                          */
1709                         chunk->pdiscard = 1;
1710                         if (asoc) {
1711                                 sctp_outq_uncork(&asoc->outqueue, gfp);
1712                                 local_cork = 0;
1713                         }
1714                         break;
1715
1716                 case SCTP_CMD_RTO_PENDING:
1717                         t = cmd->obj.transport;
1718                         t->rto_pending = 1;
1719                         break;
1720
1721                 case SCTP_CMD_PART_DELIVER:
1722                         asoc->stream.si->start_pd(&asoc->ulpq, GFP_ATOMIC);
1723                         break;
1724
1725                 case SCTP_CMD_RENEGE:
1726                         asoc->stream.si->renege_events(&asoc->ulpq,
1727                                                        cmd->obj.chunk,
1728                                                        GFP_ATOMIC);
1729                         break;
1730
1731                 case SCTP_CMD_SETUP_T4:
1732                         sctp_cmd_setup_t4(commands, asoc, cmd->obj.chunk);
1733                         break;
1734
1735                 case SCTP_CMD_PROCESS_OPERR:
1736                         sctp_cmd_process_operr(commands, asoc, chunk);
1737                         break;
1738                 case SCTP_CMD_CLEAR_INIT_TAG:
1739                         asoc->peer.i.init_tag = 0;
1740                         break;
1741                 case SCTP_CMD_DEL_NON_PRIMARY:
1742                         sctp_cmd_del_non_primary(asoc);
1743                         break;
1744                 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1745                         sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1746                         break;
1747                 case SCTP_CMD_FORCE_PRIM_RETRAN:
1748                         t = asoc->peer.retran_path;
1749                         asoc->peer.retran_path = asoc->peer.primary_path;
1750                         sctp_outq_uncork(&asoc->outqueue, gfp);
1751                         local_cork = 0;
1752                         asoc->peer.retran_path = t;
1753                         break;
1754                 case SCTP_CMD_SET_SK_ERR:
1755                         sctp_cmd_set_sk_err(asoc, cmd->obj.error);
1756                         break;
1757                 case SCTP_CMD_ASSOC_CHANGE:
1758                         sctp_cmd_assoc_change(commands, asoc,
1759                                               cmd->obj.u8);
1760                         break;
1761                 case SCTP_CMD_ADAPTATION_IND:
1762                         sctp_cmd_adaptation_ind(commands, asoc);
1763                         break;
1764                 case SCTP_CMD_PEER_NO_AUTH:
1765                         sctp_cmd_peer_no_auth(commands, asoc);
1766                         break;
1767
1768                 case SCTP_CMD_ASSOC_SHKEY:
1769                         error = sctp_auth_asoc_init_active_key(asoc,
1770                                                 GFP_ATOMIC);
1771                         break;
1772                 case SCTP_CMD_UPDATE_INITTAG:
1773                         asoc->peer.i.init_tag = cmd->obj.u32;
1774                         break;
1775                 case SCTP_CMD_SEND_MSG:
1776                         if (!asoc->outqueue.cork) {
1777                                 sctp_outq_cork(&asoc->outqueue);
1778                                 local_cork = 1;
1779                         }
1780                         sctp_cmd_send_msg(asoc, cmd->obj.msg, gfp);
1781                         break;
1782                 case SCTP_CMD_PURGE_ASCONF_QUEUE:
1783                         sctp_asconf_queue_teardown(asoc);
1784                         break;
1785
1786                 case SCTP_CMD_SET_ASOC:
1787                         if (asoc && local_cork) {
1788                                 sctp_outq_uncork(&asoc->outqueue, gfp);
1789                                 local_cork = 0;
1790                         }
1791                         asoc = cmd->obj.asoc;
1792                         break;
1793
1794                 default:
1795                         pr_warn("Impossible command: %u\n",
1796                                 cmd->verb);
1797                         break;
1798                 }
1799
1800                 if (error) {
1801                         cmd = sctp_next_cmd(commands);
1802                         while (cmd) {
1803                                 if (cmd->verb == SCTP_CMD_REPLY)
1804                                         sctp_chunk_free(cmd->obj.chunk);
1805                                 cmd = sctp_next_cmd(commands);
1806                         }
1807                         break;
1808                 }
1809         }
1810
1811         /* If this is in response to a received chunk, wait until
1812          * we are done with the packet to open the queue so that we don't
1813          * send multiple packets in response to a single request.
1814          */
1815         if (asoc && SCTP_EVENT_T_CHUNK == event_type && chunk) {
1816                 if (chunk->end_of_packet || chunk->singleton)
1817                         sctp_outq_uncork(&asoc->outqueue, gfp);
1818         } else if (local_cork)
1819                 sctp_outq_uncork(&asoc->outqueue, gfp);
1820
1821         if (sp->data_ready_signalled)
1822                 sp->data_ready_signalled = 0;
1823
1824         return error;
1825 }