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, write to
  26  * the Free Software Foundation, 59 Temple Place - Suite 330,
  27  * Boston, MA 02111-1307, USA.
  28  *
  29  * Please send any bug reports or fixes you make to the
  30  * email address(es):
  31  *    lksctp developers <lksctp-developers@lists.sourceforge.net>
  32  *
  33  * Or submit a bug report through the following website:
  34  *    http://www.sf.net/projects/lksctp
  35  *
  36  * Written or modified by:
  37  *    La Monte H.P. Yarroll <piggy@acm.org>
  38  *    Karl Knutson          <karl@athena.chicago.il.us>
  39  *    Jon Grimm             <jgrimm@austin.ibm.com>
  40  *    Hui Huang             <hui.huang@nokia.com>
  41  *    Dajiang Zhang         <dajiang.zhang@nokia.com>
  42  *    Daisy Chang           <daisyc@us.ibm.com>
  43  *    Sridhar Samudrala     <sri@us.ibm.com>
  44  *    Ardelle Fan           <ardelle.fan@intel.com>
  45  *
  46  * Any bugs reported given to us we will try to fix... any fixes shared will
  47  * be incorporated into the next SCTP release.
  48  */
  49
  50 #include <linux/skbuff.h>
  51 #include <linux/types.h>
  52 #include <linux/socket.h>
  53 #include <linux/ip.h>
  54 #include <net/sock.h>
  55 #include <net/sctp/sctp.h>
  56 #include <net/sctp/sm.h>
  57
  58 static int sctp_cmd_interpreter(sctp_event_t event_type,
  59                                 sctp_subtype_t subtype,
  60                                 sctp_state_t state,
  61                                 struct sctp_endpoint *ep,
  62                                 struct sctp_association *asoc,
  63                                 void *event_arg,
  64                                 sctp_disposition_t status,
  65                                 sctp_cmd_seq_t *commands,
  66                                 gfp_t gfp);
  67 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
  68                              sctp_state_t state,
  69                              struct sctp_endpoint *ep,
  70                              struct sctp_association *asoc,
  71                              void *event_arg,
  72                              sctp_disposition_t status,
  73                              sctp_cmd_seq_t *commands,
  74                              gfp_t gfp);
  75
  76 /********************************************************************
  77  * Helper functions
  78  ********************************************************************/
  79
  80 /* A helper function for delayed processing of INET ECN CE bit. */
  81 static void sctp_do_ecn_ce_work(struct sctp_association *asoc,
  82                                 __u32 lowest_tsn)
  83 {
  84         /* Save the TSN away for comparison when we receive CWR */
  85
  86         asoc->last_ecne_tsn = lowest_tsn;
  87         asoc->need_ecne = 1;
  88 }
  89
  90 /* Helper function for delayed processing of SCTP ECNE chunk.  */
  91 /* RFC 2960 Appendix A
  92  *
  93  * RFC 2481 details a specific bit for a sender to send in
  94  * the header of its next outbound TCP segment to indicate to
  95  * its peer that it has reduced its congestion window.  This
  96  * is termed the CWR bit.  For SCTP the same indication is made
  97  * by including the CWR chunk.  This chunk contains one data
  98  * element, i.e. the TSN number that was sent in the ECNE chunk.
  99  * This element represents the lowest TSN number in the datagram
 100  * that was originally marked with the CE bit.
 101  */
 102 static struct sctp_chunk *sctp_do_ecn_ecne_work(struct sctp_association *asoc,
 103                                            __u32 lowest_tsn,
 104                                            struct sctp_chunk *chunk)
 105 {
 106         struct sctp_chunk *repl;
 107
 108         /* Our previously transmitted packet ran into some congestion
 109          * so we should take action by reducing cwnd and ssthresh
 110          * and then ACK our peer that we we've done so by
 111          * sending a CWR.
 112          */
 113
 114         /* First, try to determine if we want to actually lower
 115          * our cwnd variables.  Only lower them if the ECNE looks more
 116          * recent than the last response.
 117          */
 118         if (TSN_lt(asoc->last_cwr_tsn, lowest_tsn)) {
 119                 struct sctp_transport *transport;
 120
 121                 /* Find which transport's congestion variables
 122                  * need to be adjusted.
 123                  */
 124                 transport = sctp_assoc_lookup_tsn(asoc, lowest_tsn);
 125
 126                 /* Update the congestion variables. */
 127                 if (transport)
 128                         sctp_transport_lower_cwnd(transport,
 129                                                   SCTP_LOWER_CWND_ECNE);
 130                 asoc->last_cwr_tsn = lowest_tsn;
 131         }
 132
 133         /* Always try to quiet the other end.  In case of lost CWR,
 134          * resend last_cwr_tsn.
 135          */
 136         repl = sctp_make_cwr(asoc, asoc->last_cwr_tsn, chunk);
 137
 138         /* If we run out of memory, it will look like a lost CWR.  We'll
 139          * get back in sync eventually.
 140          */
 141         return repl;
 142 }
 143
 144 /* Helper function to do delayed processing of ECN CWR chunk.  */
 145 static void sctp_do_ecn_cwr_work(struct sctp_association *asoc,
 146                                  __u32 lowest_tsn)
 147 {
 148         /* Turn off ECNE getting auto-prepended to every outgoing
 149          * packet
 150          */
 151         asoc->need_ecne = 0;
 152 }
 153
 154 /* Generate SACK if necessary.  We call this at the end of a packet.  */
 155 static int sctp_gen_sack(struct sctp_association *asoc, int force,
 156                          sctp_cmd_seq_t *commands)
 157 {
 158         __u32 ctsn, max_tsn_seen;
 159         struct sctp_chunk *sack;
 160         struct sctp_transport *trans = asoc->peer.last_data_from;
 161         int error = 0;
 162
 163         if (force ||
 164             (!trans && (asoc->param_flags & SPP_SACKDELAY_DISABLE)) ||
 165             (trans && (trans->param_flags & SPP_SACKDELAY_DISABLE)))
 166                 asoc->peer.sack_needed = 1;
 167
 168         ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
 169         max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
 170
 171         /* From 12.2 Parameters necessary per association (i.e. the TCB):
 172          *
 173          * Ack State : This flag indicates if the next received packet
 174          *           : is to be responded to with a SACK. ...
 175          *           : When DATA chunks are out of order, SACK's
 176          *           : are not delayed (see Section 6).
 177          *
 178          * [This is actually not mentioned in Section 6, but we
 179          * implement it here anyway. --piggy]
 180          */
 181         if (max_tsn_seen != ctsn)
 182                 asoc->peer.sack_needed = 1;
 183
 184         /* From 6.2  Acknowledgement on Reception of DATA Chunks:
 185          *
 186          * Section 4.2 of [RFC2581] SHOULD be followed. Specifically,
 187          * an acknowledgement SHOULD be generated for at least every
 188          * second packet (not every second DATA chunk) received, and
 189          * SHOULD be generated within 200 ms of the arrival of any
 190          * unacknowledged DATA chunk. ...
 191          */
 192         if (!asoc->peer.sack_needed) {
 193                 /* We will need a SACK for the next packet.  */
 194                 asoc->peer.sack_needed = 1;
 195
 196                 /* Set the SACK delay timeout based on the
 197                  * SACK delay for the last transport
 198                  * data was received from, or the default
 199                  * for the association.
 200                  */
 201                 if (trans)
 202                         asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
 203                                 trans->sackdelay;
 204                 else
 205                         asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
 206                                 asoc->sackdelay;
 207
 208                 /* Restart the SACK timer. */
 209                 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
 210                                 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
 211         } else {
 212                 if (asoc->a_rwnd > asoc->rwnd)
 213                         asoc->a_rwnd = asoc->rwnd;
 214                 sack = sctp_make_sack(asoc);
 215                 if (!sack)
 216                         goto nomem;
 217
 218                 asoc->peer.sack_needed = 0;
 219
 220                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(sack));
 221
 222                 /* Stop the SACK timer.  */
 223                 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
 224                                 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
 225         }
 226
 227         return error;
 228 nomem:
 229         error = -ENOMEM;
 230         return error;
 231 }
 232
 233 /* When the T3-RTX timer expires, it calls this function to create the
 234  * relevant state machine event.
 235  */
 236 void sctp_generate_t3_rtx_event(unsigned long peer)
 237 {
 238         int error;
 239         struct sctp_transport *transport = (struct sctp_transport *) peer;
 240         struct sctp_association *asoc = transport->asoc;
 241
 242         /* Check whether a task is in the sock.  */
 243
 244         sctp_bh_lock_sock(asoc->base.sk);
 245         if (sock_owned_by_user(asoc->base.sk)) {
 246                 SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __func__);
 247
 248                 /* Try again later.  */
 249                 if (!mod_timer(&transport->T3_rtx_timer, jiffies + (HZ/20)))
 250                         sctp_transport_hold(transport);
 251                 goto out_unlock;
 252         }
 253
 254         /* Is this transport really dead and just waiting around for
 255          * the timer to let go of the reference?
 256          */
 257         if (transport->dead)
 258                 goto out_unlock;
 259
 260         /* Run through the state machine.  */
 261         error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
 262                            SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX),
 263                            asoc->state,
 264                            asoc->ep, asoc,
 265                            transport, GFP_ATOMIC);
 266
 267         if (error)
 268                 asoc->base.sk->sk_err = -error;
 269
 270 out_unlock:
 271         sctp_bh_unlock_sock(asoc->base.sk);
 272         sctp_transport_put(transport);
 273 }
 274
 275 /* This is a sa interface for producing timeout events.  It works
 276  * for timeouts which use the association as their parameter.
 277  */
 278 static void sctp_generate_timeout_event(struct sctp_association *asoc,
 279                                         sctp_event_timeout_t timeout_type)
 280 {
 281         int error = 0;
 282
 283         sctp_bh_lock_sock(asoc->base.sk);
 284         if (sock_owned_by_user(asoc->base.sk)) {
 285                 SCTP_DEBUG_PRINTK("%s:Sock is busy: timer %d\n",
 286                                   __func__,
 287                                   timeout_type);
 288
 289                 /* Try again later.  */
 290                 if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20)))
 291                         sctp_association_hold(asoc);
 292                 goto out_unlock;
 293         }
 294
 295         /* Is this association really dead and just waiting around for
 296          * the timer to let go of the reference?
 297          */
 298         if (asoc->base.dead)
 299                 goto out_unlock;
 300
 301         /* Run through the state machine.  */
 302         error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
 303                            SCTP_ST_TIMEOUT(timeout_type),
 304                            asoc->state, asoc->ep, asoc,
 305                            (void *)timeout_type, GFP_ATOMIC);
 306
 307         if (error)
 308                 asoc->base.sk->sk_err = -error;
 309
 310 out_unlock:
 311         sctp_bh_unlock_sock(asoc->base.sk);
 312         sctp_association_put(asoc);
 313 }
 314
 315 static void sctp_generate_t1_cookie_event(unsigned long data)
 316 {
 317         struct sctp_association *asoc = (struct sctp_association *) data;
 318         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
 319 }
 320
 321 static void sctp_generate_t1_init_event(unsigned long data)
 322 {
 323         struct sctp_association *asoc = (struct sctp_association *) data;
 324         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
 325 }
 326
 327 static void sctp_generate_t2_shutdown_event(unsigned long data)
 328 {
 329         struct sctp_association *asoc = (struct sctp_association *) data;
 330         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
 331 }
 332
 333 static void sctp_generate_t4_rto_event(unsigned long data)
 334 {
 335         struct sctp_association *asoc = (struct sctp_association *) data;
 336         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
 337 }
 338
 339 static void sctp_generate_t5_shutdown_guard_event(unsigned long data)
 340 {
 341         struct sctp_association *asoc = (struct sctp_association *)data;
 342         sctp_generate_timeout_event(asoc,
 343                                     SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);
 344
 345 } /* sctp_generate_t5_shutdown_guard_event() */
 346
 347 static void sctp_generate_autoclose_event(unsigned long data)
 348 {
 349         struct sctp_association *asoc = (struct sctp_association *) data;
 350         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE);
 351 }
 352
 353 /* Generate a heart beat event.  If the sock is busy, reschedule.   Make
 354  * sure that the transport is still valid.
 355  */
 356 void sctp_generate_heartbeat_event(unsigned long data)
 357 {
 358         int error = 0;
 359         struct sctp_transport *transport = (struct sctp_transport *) data;
 360         struct sctp_association *asoc = transport->asoc;
 361
 362         sctp_bh_lock_sock(asoc->base.sk);
 363         if (sock_owned_by_user(asoc->base.sk)) {
 364                 SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __func__);
 365
 366                 /* Try again later.  */
 367                 if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20)))
 368                         sctp_transport_hold(transport);
 369                 goto out_unlock;
 370         }
 371
 372         /* Is this structure just waiting around for us to actually
 373          * get destroyed?
 374          */
 375         if (transport->dead)
 376                 goto out_unlock;
 377
 378         error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
 379                            SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
 380                            asoc->state, asoc->ep, asoc,
 381                            transport, GFP_ATOMIC);
 382
 383          if (error)
 384                  asoc->base.sk->sk_err = -error;
 385
 386 out_unlock:
 387         sctp_bh_unlock_sock(asoc->base.sk);
 388         sctp_transport_put(transport);
 389 }
 390
 391 /* Inject a SACK Timeout event into the state machine.  */
 392 static void sctp_generate_sack_event(unsigned long data)
 393 {
 394         struct sctp_association *asoc = (struct sctp_association *) data;
 395         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
 396 }
 397
 398 sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
 399         NULL,
 400         sctp_generate_t1_cookie_event,
 401         sctp_generate_t1_init_event,
 402         sctp_generate_t2_shutdown_event,
 403         NULL,
 404         sctp_generate_t4_rto_event,
 405         sctp_generate_t5_shutdown_guard_event,
 406         NULL,
 407         sctp_generate_sack_event,
 408         sctp_generate_autoclose_event,
 409 };
 410
 411
 412 /* RFC 2960 8.2 Path Failure Detection
 413  *
 414  * When its peer endpoint is multi-homed, an endpoint should keep a
 415  * error counter for each of the destination transport addresses of the
 416  * peer endpoint.
 417  *
 418  * Each time the T3-rtx timer expires on any address, or when a
 419  * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
 420  * the error counter of that destination address will be incremented.
 421  * When the value in the error counter exceeds the protocol parameter
 422  * 'Path.Max.Retrans' of that destination address, the endpoint should
 423  * mark the destination transport address as inactive, and a
 424  * notification SHOULD be sent to the upper layer.
 425  *
 426  */
 427 static void sctp_do_8_2_transport_strike(struct sctp_association *asoc,
 428                                          struct sctp_transport *transport)
 429 {
 430         /* The check for association's overall error counter exceeding the
 431          * threshold is done in the state function.
 432          */
 433         /* When probing UNCONFIRMED addresses, the association overall
 434          * error count is NOT incremented
 435          */
 436         if (transport->state != SCTP_UNCONFIRMED)
 437                 asoc->overall_error_count++;
 438
 439         if (transport->state != SCTP_INACTIVE &&
 440             (transport->error_count++ >= transport->pathmaxrxt)) {
 441                 SCTP_DEBUG_PRINTK_IPADDR("transport_strike:association %p",
 442                                          " transport IP: port:%d failed.\n",
 443                                          asoc,
 444                                          (&transport->ipaddr),
 445                                          ntohs(transport->ipaddr.v4.sin_port));
 446                 sctp_assoc_control_transport(asoc, transport,
 447                                              SCTP_TRANSPORT_DOWN,
 448                                              SCTP_FAILED_THRESHOLD);
 449         }
 450
 451         /* E2) For the destination address for which the timer
 452          * expires, set RTO <- RTO * 2 ("back off the timer").  The
 453          * maximum value discussed in rule C7 above (RTO.max) may be
 454          * used to provide an upper bound to this doubling operation.
 455          */
 456         transport->last_rto = transport->rto;
 457         transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
 458 }
 459
 460 /* Worker routine to handle INIT command failure.  */
 461 static void sctp_cmd_init_failed(sctp_cmd_seq_t *commands,
 462                                  struct sctp_association *asoc,
 463                                  unsigned error)
 464 {
 465         struct sctp_ulpevent *event;
 466
 467         event = sctp_ulpevent_make_assoc_change(asoc,0, SCTP_CANT_STR_ASSOC,
 468                                                 (__u16)error, 0, 0, NULL,
 469                                                 GFP_ATOMIC);
 470
 471         if (event)
 472                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 473                                 SCTP_ULPEVENT(event));
 474
 475         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 476                         SCTP_STATE(SCTP_STATE_CLOSED));
 477
 478         /* SEND_FAILED sent later when cleaning up the association. */
 479         asoc->outqueue.error = error;
 480         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 481 }
 482
 483 /* Worker routine to handle SCTP_CMD_ASSOC_FAILED.  */
 484 static void sctp_cmd_assoc_failed(sctp_cmd_seq_t *commands,
 485                                   struct sctp_association *asoc,
 486                                   sctp_event_t event_type,
 487                                   sctp_subtype_t subtype,
 488                                   struct sctp_chunk *chunk,
 489                                   unsigned error)
 490 {
 491         struct sctp_ulpevent *event;
 492
 493         /* Cancel any partial delivery in progress. */
 494         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
 495
 496         if (event_type == SCTP_EVENT_T_CHUNK && subtype.chunk == SCTP_CID_ABORT)
 497                 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
 498                                                 (__u16)error, 0, 0, chunk,
 499                                                 GFP_ATOMIC);
 500         else
 501                 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
 502                                                 (__u16)error, 0, 0, NULL,
 503                                                 GFP_ATOMIC);
 504         if (event)
 505                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 506                                 SCTP_ULPEVENT(event));
 507
 508         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 509                         SCTP_STATE(SCTP_STATE_CLOSED));
 510
 511         /* SEND_FAILED sent later when cleaning up the association. */
 512         asoc->outqueue.error = error;
 513         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 514 }
 515
 516 /* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
 517  * inside the cookie.  In reality, this is only used for INIT-ACK processing
 518  * since all other cases use "temporary" associations and can do all
 519  * their work in statefuns directly.
 520  */
 521 static int sctp_cmd_process_init(sctp_cmd_seq_t *commands,
 522                                  struct sctp_association *asoc,
 523                                  struct sctp_chunk *chunk,
 524                                  sctp_init_chunk_t *peer_init,
 525                                  gfp_t gfp)
 526 {
 527         int error;
 528
 529         /* We only process the init as a sideeffect in a single
 530          * case.   This is when we process the INIT-ACK.   If we
 531          * fail during INIT processing (due to malloc problems),
 532          * just return the error and stop processing the stack.
 533          */
 534         if (!sctp_process_init(asoc, chunk->chunk_hdr->type,
 535                                sctp_source(chunk), peer_init, gfp))
 536                 error = -ENOMEM;
 537         else
 538                 error = 0;
 539
 540         return error;
 541 }
 542
 543 /* Helper function to break out starting up of heartbeat timers.  */
 544 static void sctp_cmd_hb_timers_start(sctp_cmd_seq_t *cmds,
 545                                      struct sctp_association *asoc)
 546 {
 547         struct sctp_transport *t;
 548
 549         /* Start a heartbeat timer for each transport on the association.
 550          * hold a reference on the transport to make sure none of
 551          * the needed data structures go away.
 552          */
 553         list_for_each_entry(t, &asoc->peer.transport_addr_list, transports) {
 554
 555                 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 556                         sctp_transport_hold(t);
 557         }
 558 }
 559
 560 static void sctp_cmd_hb_timers_stop(sctp_cmd_seq_t *cmds,
 561                                     struct sctp_association *asoc)
 562 {
 563         struct sctp_transport *t;
 564
 565         /* Stop all heartbeat timers. */
 566
 567         list_for_each_entry(t, &asoc->peer.transport_addr_list,
 568                         transports) {
 569                 if (del_timer(&t->hb_timer))
 570                         sctp_transport_put(t);
 571         }
 572 }
 573
 574 /* Helper function to stop any pending T3-RTX timers */
 575 static void sctp_cmd_t3_rtx_timers_stop(sctp_cmd_seq_t *cmds,
 576                                         struct sctp_association *asoc)
 577 {
 578         struct sctp_transport *t;
 579
 580         list_for_each_entry(t, &asoc->peer.transport_addr_list,
 581                         transports) {
 582                 if (timer_pending(&t->T3_rtx_timer) &&
 583                     del_timer(&t->T3_rtx_timer)) {
 584                         sctp_transport_put(t);
 585                 }
 586         }
 587 }
 588
 589
 590 /* Helper function to update the heartbeat timer. */
 591 static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
 592                                      struct sctp_transport *t)
 593 {
 594         /* Update the heartbeat timer.  */
 595         if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 596                 sctp_transport_hold(t);
 597 }
 598
 599 /* Helper function to handle the reception of an HEARTBEAT ACK.  */
 600 static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds,
 601                                   struct sctp_association *asoc,
 602                                   struct sctp_transport *t,
 603                                   struct sctp_chunk *chunk)
 604 {
 605         sctp_sender_hb_info_t *hbinfo;
 606
 607         /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
 608          * HEARTBEAT should clear the error counter of the destination
 609          * transport address to which the HEARTBEAT was sent.
 610          * The association's overall error count is also cleared.
 611          */
 612         t->error_count = 0;
 613         t->asoc->overall_error_count = 0;
 614
 615         /* Mark the destination transport address as active if it is not so
 616          * marked.
 617          */
 618         if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED))
 619                 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
 620                                              SCTP_HEARTBEAT_SUCCESS);
 621
 622         /* The receiver of the HEARTBEAT ACK should also perform an
 623          * RTT measurement for that destination transport address
 624          * using the time value carried in the HEARTBEAT ACK chunk.
 625          * If the transport's rto_pending variable has been cleared,
 626          * it was most likely due to a retransmit.  However, we want
 627          * to re-enable it to properly update the rto.
 628          */
 629         if (t->rto_pending == 0)
 630                 t->rto_pending = 1;
 631
 632         hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
 633         sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
 634
 635         /* Update the heartbeat timer.  */
 636         if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 637                 sctp_transport_hold(t);
 638 }
 639
 640 /* Helper function to do a transport reset at the expiry of the hearbeat
 641  * timer.
 642  */
 643 static void sctp_cmd_transport_reset(sctp_cmd_seq_t *cmds,
 644                                      struct sctp_association *asoc,
 645                                      struct sctp_transport *t)
 646 {
 647         sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
 648
 649         /* Mark one strike against a transport.  */
 650         sctp_do_8_2_transport_strike(asoc, t);
 651 }
 652
 653 /* Helper function to process the process SACK command.  */
 654 static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds,
 655                                  struct sctp_association *asoc,
 656                                  struct sctp_sackhdr *sackh)
 657 {
 658         int err;
 659
 660         if (sctp_outq_sack(&asoc->outqueue, sackh)) {
 661                 /* There are no more TSNs awaiting SACK.  */
 662                 err = sctp_do_sm(SCTP_EVENT_T_OTHER,
 663                                  SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
 664                                  asoc->state, asoc->ep, asoc, NULL,
 665                                  GFP_ATOMIC);
 666         } else {
 667                 /* Windows may have opened, so we need
 668                  * to check if we have DATA to transmit
 669                  */
 670                 err = sctp_outq_flush(&asoc->outqueue, 0);
 671         }
 672
 673         return err;
 674 }
 675
 676 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
 677  * the transport for a shutdown chunk.
 678  */
 679 static void sctp_cmd_setup_t2(sctp_cmd_seq_t *cmds,
 680                               struct sctp_association *asoc,
 681                               struct sctp_chunk *chunk)
 682 {
 683         struct sctp_transport *t;
 684
 685         t = sctp_assoc_choose_shutdown_transport(asoc);
 686         asoc->shutdown_last_sent_to = t;
 687         asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
 688         chunk->transport = t;
 689 }
 690
 691 /* Helper function to change the state of an association. */
 692 static void sctp_cmd_new_state(sctp_cmd_seq_t *cmds,
 693                                struct sctp_association *asoc,
 694                                sctp_state_t state)
 695 {
 696         struct sock *sk = asoc->base.sk;
 697
 698         asoc->state = state;
 699
 700         SCTP_DEBUG_PRINTK("sctp_cmd_new_state: asoc %p[%s]\n",
 701                           asoc, sctp_state_tbl[state]);
 702
 703         if (sctp_style(sk, TCP)) {
 704                 /* Change the sk->sk_state of a TCP-style socket that has
 705                  * sucessfully completed a connect() call.
 706                  */
 707                 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
 708                         sk->sk_state = SCTP_SS_ESTABLISHED;
 709
 710                 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
 711                 if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
 712                     sctp_sstate(sk, ESTABLISHED))
 713                         sk->sk_shutdown |= RCV_SHUTDOWN;
 714         }
 715
 716         if (sctp_state(asoc, COOKIE_WAIT)) {
 717                 /* Reset init timeouts since they may have been
 718                  * increased due to timer expirations.
 719                  */
 720                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
 721                                                 asoc->rto_initial;
 722                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
 723                                                 asoc->rto_initial;
 724         }
 725
 726         if (sctp_state(asoc, ESTABLISHED) ||
 727             sctp_state(asoc, CLOSED) ||
 728             sctp_state(asoc, SHUTDOWN_RECEIVED)) {
 729                 /* Wake up any processes waiting in the asoc's wait queue in
 730                  * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
 731                  */
 732                 if (waitqueue_active(&asoc->wait))
 733                         wake_up_interruptible(&asoc->wait);
 734
 735                 /* Wake up any processes waiting in the sk's sleep queue of
 736                  * a TCP-style or UDP-style peeled-off socket in
 737                  * sctp_wait_for_accept() or sctp_wait_for_packet().
 738                  * For a UDP-style socket, the waiters are woken up by the
 739                  * notifications.
 740                  */
 741                 if (!sctp_style(sk, UDP))
 742                         sk->sk_state_change(sk);
 743         }
 744 }
 745
 746 /* Helper function to delete an association. */
 747 static void sctp_cmd_delete_tcb(sctp_cmd_seq_t *cmds,
 748                                 struct sctp_association *asoc)
 749 {
 750         struct sock *sk = asoc->base.sk;
 751
 752         /* If it is a non-temporary association belonging to a TCP-style
 753          * listening socket that is not closed, do not free it so that accept()
 754          * can pick it up later.
 755          */
 756         if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
 757             (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
 758                 return;
 759
 760         sctp_unhash_established(asoc);
 761         sctp_association_free(asoc);
 762 }
 763
 764 /*
 765  * ADDIP Section 4.1 ASCONF Chunk Procedures
 766  * A4) Start a T-4 RTO timer, using the RTO value of the selected
 767  * destination address (we use active path instead of primary path just
 768  * because primary path may be inactive.
 769  */
 770 static void sctp_cmd_setup_t4(sctp_cmd_seq_t *cmds,
 771                                 struct sctp_association *asoc,
 772                                 struct sctp_chunk *chunk)
 773 {
 774         struct sctp_transport *t;
 775
 776         t = asoc->peer.active_path;
 777         asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
 778         chunk->transport = t;
 779 }
 780
 781 /* Process an incoming Operation Error Chunk. */
 782 static void sctp_cmd_process_operr(sctp_cmd_seq_t *cmds,
 783                                    struct sctp_association *asoc,
 784                                    struct sctp_chunk *chunk)
 785 {
 786         struct sctp_operr_chunk *operr_chunk;
 787         struct sctp_errhdr *err_hdr;
 788
 789         operr_chunk = (struct sctp_operr_chunk *)chunk->chunk_hdr;
 790         err_hdr = &operr_chunk->err_hdr;
 791
 792         switch (err_hdr->cause) {
 793         case SCTP_ERROR_UNKNOWN_CHUNK:
 794         {
 795                 struct sctp_chunkhdr *unk_chunk_hdr;
 796
 797                 unk_chunk_hdr = (struct sctp_chunkhdr *)err_hdr->variable;
 798                 switch (unk_chunk_hdr->type) {
 799                 /* ADDIP 4.1 A9) If the peer responds to an ASCONF with an
 800                  * ERROR chunk reporting that it did not recognized the ASCONF
 801                  * chunk type, the sender of the ASCONF MUST NOT send any
 802                  * further ASCONF chunks and MUST stop its T-4 timer.
 803                  */
 804                 case SCTP_CID_ASCONF:
 805                         asoc->peer.asconf_capable = 0;
 806                         sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
 807                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
 808                         break;
 809                 default:
 810                         break;
 811                 }
 812                 break;
 813         }
 814         default:
 815                 break;
 816         }
 817 }
 818
 819 /* Process variable FWDTSN chunk information. */
 820 static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq,
 821                                     struct sctp_chunk *chunk)
 822 {
 823         struct sctp_fwdtsn_skip *skip;
 824         /* Walk through all the skipped SSNs */
 825         sctp_walk_fwdtsn(skip, chunk) {
 826                 sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
 827         }
 828
 829         return;
 830 }
 831
 832 /* Helper function to remove the association non-primary peer
 833  * transports.
 834  */
 835 static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
 836 {
 837         struct sctp_transport *t;
 838         struct list_head *pos;
 839         struct list_head *temp;
 840
 841         list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
 842                 t = list_entry(pos, struct sctp_transport, transports);
 843                 if (!sctp_cmp_addr_exact(&t->ipaddr,
 844                                          &asoc->peer.primary_addr)) {
 845                         sctp_assoc_del_peer(asoc, &t->ipaddr);
 846                 }
 847         }
 848
 849         return;
 850 }
 851
 852 /* Helper function to set sk_err on a 1-1 style socket. */
 853 static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
 854 {
 855         struct sock *sk = asoc->base.sk;
 856
 857         if (!sctp_style(sk, UDP))
 858                 sk->sk_err = error;
 859 }
 860
 861 /* Helper function to generate an association change event */
 862 static void sctp_cmd_assoc_change(sctp_cmd_seq_t *commands,
 863                                  struct sctp_association *asoc,
 864                                  u8 state)
 865 {
 866         struct sctp_ulpevent *ev;
 867
 868         ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0,
 869                                             asoc->c.sinit_num_ostreams,
 870                                             asoc->c.sinit_max_instreams,
 871                                             NULL, GFP_ATOMIC);
 872         if (ev)
 873                 sctp_ulpq_tail_event(&asoc->ulpq, ev);
 874 }
 875
 876 /* Helper function to generate an adaptation indication event */
 877 static void sctp_cmd_adaptation_ind(sctp_cmd_seq_t *commands,
 878                                     struct sctp_association *asoc)
 879 {
 880         struct sctp_ulpevent *ev;
 881
 882         ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
 883
 884         if (ev)
 885                 sctp_ulpq_tail_event(&asoc->ulpq, ev);
 886 }
 887
 888 /* These three macros allow us to pull the debugging code out of the
 889  * main flow of sctp_do_sm() to keep attention focused on the real
 890  * functionality there.
 891  */
 892 #define DEBUG_PRE \
 893         SCTP_DEBUG_PRINTK("sctp_do_sm prefn: " \
 894                           "ep %p, %s, %s, asoc %p[%s], %s\n", \
 895                           ep, sctp_evttype_tbl[event_type], \
 896                           (*debug_fn)(subtype), asoc, \
 897                           sctp_state_tbl[state], state_fn->name)
 898
 899 #define DEBUG_POST \
 900         SCTP_DEBUG_PRINTK("sctp_do_sm postfn: " \
 901                           "asoc %p, status: %s\n", \
 902                           asoc, sctp_status_tbl[status])
 903
 904 #define DEBUG_POST_SFX \
 905         SCTP_DEBUG_PRINTK("sctp_do_sm post sfx: error %d, asoc %p[%s]\n", \
 906                           error, asoc, \
 907                           sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
 908                           sctp_assoc2id(asoc)))?asoc->state:SCTP_STATE_CLOSED])
 909
 910 /*
 911  * This is the master state machine processing function.
 912  *
 913  * If you want to understand all of lksctp, this is a
 914  * good place to start.
 915  */
 916 int sctp_do_sm(sctp_event_t event_type, sctp_subtype_t subtype,
 917                sctp_state_t state,
 918                struct sctp_endpoint *ep,
 919                struct sctp_association *asoc,
 920                void *event_arg,
 921                gfp_t gfp)
 922 {
 923         sctp_cmd_seq_t commands;
 924         const sctp_sm_table_entry_t *state_fn;
 925         sctp_disposition_t status;
 926         int error = 0;
 927         typedef const char *(printfn_t)(sctp_subtype_t);
 928
 929         static printfn_t *table[] = {
 930                 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
 931         };
 932         printfn_t *debug_fn  __attribute__ ((unused)) = table[event_type];
 933
 934         /* Look up the state function, run it, and then process the
 935          * side effects.  These three steps are the heart of lksctp.
 936          */
 937         state_fn = sctp_sm_lookup_event(event_type, state, subtype);
 938
 939         sctp_init_cmd_seq(&commands);
 940
 941         DEBUG_PRE;
 942         status = (*state_fn->fn)(ep, asoc, subtype, event_arg, &commands);
 943         DEBUG_POST;
 944
 945         error = sctp_side_effects(event_type, subtype, state,
 946                                   ep, asoc, event_arg, status,
 947                                   &commands, gfp);
 948         DEBUG_POST_SFX;
 949
 950         return error;
 951 }
 952
 953 #undef DEBUG_PRE
 954 #undef DEBUG_POST
 955
 956 /*****************************************************************
 957  * This the master state function side effect processing function.
 958  *****************************************************************/
 959 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
 960                              sctp_state_t state,
 961                              struct sctp_endpoint *ep,
 962                              struct sctp_association *asoc,
 963                              void *event_arg,
 964                              sctp_disposition_t status,
 965                              sctp_cmd_seq_t *commands,
 966                              gfp_t gfp)
 967 {
 968         int error;
 969
 970         /* FIXME - Most of the dispositions left today would be categorized
 971          * as "exceptional" dispositions.  For those dispositions, it
 972          * may not be proper to run through any of the commands at all.
 973          * For example, the command interpreter might be run only with
 974          * disposition SCTP_DISPOSITION_CONSUME.
 975          */
 976         if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
 977                                                ep, asoc,
 978                                                event_arg, status,
 979                                                commands, gfp)))
 980                 goto bail;
 981
 982         switch (status) {
 983         case SCTP_DISPOSITION_DISCARD:
 984                 SCTP_DEBUG_PRINTK("Ignored sctp protocol event - state %d, "
 985                                   "event_type %d, event_id %d\n",
 986                                   state, event_type, subtype.chunk);
 987                 break;
 988
 989         case SCTP_DISPOSITION_NOMEM:
 990                 /* We ran out of memory, so we need to discard this
 991                  * packet.
 992                  */
 993                 /* BUG--we should now recover some memory, probably by
 994                  * reneging...
 995                  */
 996                 error = -ENOMEM;
 997                 break;
 998
 999         case SCTP_DISPOSITION_DELETE_TCB:
1000                 /* This should now be a command. */
1001                 break;
1002
1003         case SCTP_DISPOSITION_CONSUME:
1004         case SCTP_DISPOSITION_ABORT:
1005                 /*
1006                  * We should no longer have much work to do here as the
1007                  * real work has been done as explicit commands above.
1008                  */
1009                 break;
1010
1011         case SCTP_DISPOSITION_VIOLATION:
1012                 if (net_ratelimit())
1013                         printk(KERN_ERR "sctp protocol violation state %d "
1014                                "chunkid %d\n", state, subtype.chunk);
1015                 break;
1016
1017         case SCTP_DISPOSITION_NOT_IMPL:
1018                 printk(KERN_WARNING "sctp unimplemented feature in state %d, "
1019                        "event_type %d, event_id %d\n",
1020                        state, event_type, subtype.chunk);
1021                 break;
1022
1023         case SCTP_DISPOSITION_BUG:
1024                 printk(KERN_ERR "sctp bug in state %d, "
1025                        "event_type %d, event_id %d\n",
1026                        state, event_type, subtype.chunk);
1027                 BUG();
1028                 break;
1029
1030         default:
1031                 printk(KERN_ERR "sctp impossible disposition %d "
1032                        "in state %d, event_type %d, event_id %d\n",
1033                        status, state, event_type, subtype.chunk);
1034                 BUG();
1035                 break;
1036         }
1037
1038 bail:
1039         return error;
1040 }
1041
1042 /********************************************************************
1043  * 2nd Level Abstractions
1044  ********************************************************************/
1045
1046 /* This is the side-effect interpreter.  */
1047 static int sctp_cmd_interpreter(sctp_event_t event_type,
1048                                 sctp_subtype_t subtype,
1049                                 sctp_state_t state,
1050                                 struct sctp_endpoint *ep,
1051                                 struct sctp_association *asoc,
1052                                 void *event_arg,
1053                                 sctp_disposition_t status,
1054                                 sctp_cmd_seq_t *commands,
1055                                 gfp_t gfp)
1056 {
1057         int error = 0;
1058         int force;
1059         sctp_cmd_t *cmd;
1060         struct sctp_chunk *new_obj;
1061         struct sctp_chunk *chunk = NULL;
1062         struct sctp_packet *packet;
1063         struct timer_list *timer;
1064         unsigned long timeout;
1065         struct sctp_transport *t;
1066         struct sctp_sackhdr sackh;
1067         int local_cork = 0;
1068
1069         if (SCTP_EVENT_T_TIMEOUT != event_type)
1070                 chunk = (struct sctp_chunk *) event_arg;
1071
1072         /* Note:  This whole file is a huge candidate for rework.
1073          * For example, each command could either have its own handler, so
1074          * the loop would look like:
1075          *     while (cmds)
1076          *         cmd->handle(x, y, z)
1077          * --jgrimm
1078          */
1079         while (NULL != (cmd = sctp_next_cmd(commands))) {
1080                 switch (cmd->verb) {
1081                 case SCTP_CMD_NOP:
1082                         /* Do nothing. */
1083                         break;
1084
1085                 case SCTP_CMD_NEW_ASOC:
1086                         /* Register a new association.  */
1087                         if (local_cork) {
1088                                 sctp_outq_uncork(&asoc->outqueue);
1089                                 local_cork = 0;
1090                         }
1091                         asoc = cmd->obj.ptr;
1092                         /* Register with the endpoint.  */
1093                         sctp_endpoint_add_asoc(ep, asoc);
1094                         sctp_hash_established(asoc);
1095                         break;
1096
1097                 case SCTP_CMD_UPDATE_ASSOC:
1098                        sctp_assoc_update(asoc, cmd->obj.ptr);
1099                        break;
1100
1101                 case SCTP_CMD_PURGE_OUTQUEUE:
1102                        sctp_outq_teardown(&asoc->outqueue);
1103                        break;
1104
1105                 case SCTP_CMD_DELETE_TCB:
1106                         if (local_cork) {
1107                                 sctp_outq_uncork(&asoc->outqueue);
1108                                 local_cork = 0;
1109                         }
1110                         /* Delete the current association.  */
1111                         sctp_cmd_delete_tcb(commands, asoc);
1112                         asoc = NULL;
1113                         break;
1114
1115                 case SCTP_CMD_NEW_STATE:
1116                         /* Enter a new state.  */
1117                         sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1118                         break;
1119
1120                 case SCTP_CMD_REPORT_TSN:
1121                         /* Record the arrival of a TSN.  */
1122                         sctp_tsnmap_mark(&asoc->peer.tsn_map, cmd->obj.u32);
1123                         break;
1124
1125                 case SCTP_CMD_REPORT_FWDTSN:
1126                         /* Move the Cumulattive TSN Ack ahead. */
1127                         sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32);
1128
1129                         /* purge the fragmentation queue */
1130                         sctp_ulpq_reasm_flushtsn(&asoc->ulpq, cmd->obj.u32);
1131
1132                         /* Abort any in progress partial delivery. */
1133                         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
1134                         break;
1135
1136                 case SCTP_CMD_PROCESS_FWDTSN:
1137                         sctp_cmd_process_fwdtsn(&asoc->ulpq, cmd->obj.ptr);
1138                         break;
1139
1140                 case SCTP_CMD_GEN_SACK:
1141                         /* Generate a Selective ACK.
1142                          * The argument tells us whether to just count
1143                          * the packet and MAYBE generate a SACK, or
1144                          * force a SACK out.
1145                          */
1146                         force = cmd->obj.i32;
1147                         error = sctp_gen_sack(asoc, force, commands);
1148                         break;
1149
1150                 case SCTP_CMD_PROCESS_SACK:
1151                         /* Process an inbound SACK.  */
1152                         error = sctp_cmd_process_sack(commands, asoc,
1153                                                       cmd->obj.ptr);
1154                         break;
1155
1156                 case SCTP_CMD_GEN_INIT_ACK:
1157                         /* Generate an INIT ACK chunk.  */
1158                         new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1159                                                      0);
1160                         if (!new_obj)
1161                                 goto nomem;
1162
1163                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1164                                         SCTP_CHUNK(new_obj));
1165                         break;
1166
1167                 case SCTP_CMD_PEER_INIT:
1168                         /* Process a unified INIT from the peer.
1169                          * Note: Only used during INIT-ACK processing.  If
1170                          * there is an error just return to the outter
1171                          * layer which will bail.
1172                          */
1173                         error = sctp_cmd_process_init(commands, asoc, chunk,
1174                                                       cmd->obj.ptr, gfp);
1175                         break;
1176
1177                 case SCTP_CMD_GEN_COOKIE_ECHO:
1178                         /* Generate a COOKIE ECHO chunk.  */
1179                         new_obj = sctp_make_cookie_echo(asoc, chunk);
1180                         if (!new_obj) {
1181                                 if (cmd->obj.ptr)
1182                                         sctp_chunk_free(cmd->obj.ptr);
1183                                 goto nomem;
1184                         }
1185                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1186                                         SCTP_CHUNK(new_obj));
1187
1188                         /* If there is an ERROR chunk to be sent along with
1189                          * the COOKIE_ECHO, send it, too.
1190                          */
1191                         if (cmd->obj.ptr)
1192                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1193                                                 SCTP_CHUNK(cmd->obj.ptr));
1194
1195                         /* FIXME - Eventually come up with a cleaner way to
1196                          * enabling COOKIE-ECHO + DATA bundling during
1197                          * multihoming stale cookie scenarios, the following
1198                          * command plays with asoc->peer.retran_path to
1199                          * avoid the problem of sending the COOKIE-ECHO and
1200                          * DATA in different paths, which could result
1201                          * in the association being ABORTed if the DATA chunk
1202                          * is processed first by the server.  Checking the
1203                          * init error counter simply causes this command
1204                          * to be executed only during failed attempts of
1205                          * association establishment.
1206                          */
1207                         if ((asoc->peer.retran_path !=
1208                              asoc->peer.primary_path) &&
1209                             (asoc->init_err_counter > 0)) {
1210                                 sctp_add_cmd_sf(commands,
1211                                                 SCTP_CMD_FORCE_PRIM_RETRAN,
1212                                                 SCTP_NULL());
1213                         }
1214
1215                         break;
1216
1217                 case SCTP_CMD_GEN_SHUTDOWN:
1218                         /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1219                          * Reset error counts.
1220                          */
1221                         asoc->overall_error_count = 0;
1222
1223                         /* Generate a SHUTDOWN chunk.  */
1224                         new_obj = sctp_make_shutdown(asoc, chunk);
1225                         if (!new_obj)
1226                                 goto nomem;
1227                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1228                                         SCTP_CHUNK(new_obj));
1229                         break;
1230
1231                 case SCTP_CMD_CHUNK_ULP:
1232                         /* Send a chunk to the sockets layer.  */
1233                         SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1234                                           "chunk_up:", cmd->obj.ptr,
1235                                           "ulpq:", &asoc->ulpq);
1236                         sctp_ulpq_tail_data(&asoc->ulpq, cmd->obj.ptr,
1237                                             GFP_ATOMIC);
1238                         break;
1239
1240                 case SCTP_CMD_EVENT_ULP:
1241                         /* Send a notification to the sockets layer.  */
1242                         SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1243                                           "event_up:",cmd->obj.ptr,
1244                                           "ulpq:",&asoc->ulpq);
1245                         sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ptr);
1246                         break;
1247
1248                 case SCTP_CMD_REPLY:
1249                         /* If an caller has not already corked, do cork. */
1250                         if (!asoc->outqueue.cork) {
1251                                 sctp_outq_cork(&asoc->outqueue);
1252                                 local_cork = 1;
1253                         }
1254                         /* Send a chunk to our peer.  */
1255                         error = sctp_outq_tail(&asoc->outqueue, cmd->obj.ptr);
1256                         break;
1257
1258                 case SCTP_CMD_SEND_PKT:
1259                         /* Send a full packet to our peer.  */
1260                         packet = cmd->obj.ptr;
1261                         sctp_packet_transmit(packet);
1262                         sctp_ootb_pkt_free(packet);
1263                         break;
1264
1265                 case SCTP_CMD_T1_RETRAN:
1266                         /* Mark a transport for retransmission.  */
1267                         sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1268                                         SCTP_RTXR_T1_RTX);
1269                         break;
1270
1271                 case SCTP_CMD_RETRAN:
1272                         /* Mark a transport for retransmission.  */
1273                         sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1274                                         SCTP_RTXR_T3_RTX);
1275                         break;
1276
1277                 case SCTP_CMD_TRANSMIT:
1278                         /* Kick start transmission. */
1279                         error = sctp_outq_uncork(&asoc->outqueue);
1280                         local_cork = 0;
1281                         break;
1282
1283                 case SCTP_CMD_ECN_CE:
1284                         /* Do delayed CE processing.   */
1285                         sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1286                         break;
1287
1288                 case SCTP_CMD_ECN_ECNE:
1289                         /* Do delayed ECNE processing. */
1290                         new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1291                                                         chunk);
1292                         if (new_obj)
1293                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1294                                                 SCTP_CHUNK(new_obj));
1295                         break;
1296
1297                 case SCTP_CMD_ECN_CWR:
1298                         /* Do delayed CWR processing.  */
1299                         sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1300                         break;
1301
1302                 case SCTP_CMD_SETUP_T2:
1303                         sctp_cmd_setup_t2(commands, asoc, cmd->obj.ptr);
1304                         break;
1305
1306                 case SCTP_CMD_TIMER_START:
1307                         timer = &asoc->timers[cmd->obj.to];
1308                         timeout = asoc->timeouts[cmd->obj.to];
1309                         BUG_ON(!timeout);
1310
1311                         timer->expires = jiffies + timeout;
1312                         sctp_association_hold(asoc);
1313                         add_timer(timer);
1314                         break;
1315
1316                 case SCTP_CMD_TIMER_RESTART:
1317                         timer = &asoc->timers[cmd->obj.to];
1318                         timeout = asoc->timeouts[cmd->obj.to];
1319                         if (!mod_timer(timer, jiffies + timeout))
1320                                 sctp_association_hold(asoc);
1321                         break;
1322
1323                 case SCTP_CMD_TIMER_STOP:
1324                         timer = &asoc->timers[cmd->obj.to];
1325                         if (timer_pending(timer) && del_timer(timer))
1326                                 sctp_association_put(asoc);
1327                         break;
1328
1329                 case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1330                         chunk = cmd->obj.ptr;
1331                         t = sctp_assoc_choose_init_transport(asoc);
1332                         asoc->init_last_sent_to = t;
1333                         chunk->transport = t;
1334                         t->init_sent_count++;
1335                         break;
1336
1337                 case SCTP_CMD_INIT_RESTART:
1338                         /* Do the needed accounting and updates
1339                          * associated with restarting an initialization
1340                          * timer. Only multiply the timeout by two if
1341                          * all transports have been tried at the current
1342                          * timeout.
1343                          */
1344                         t = asoc->init_last_sent_to;
1345                         asoc->init_err_counter++;
1346
1347                         if (t->init_sent_count > (asoc->init_cycle + 1)) {
1348                                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] *= 2;
1349                                 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] >
1350                                     asoc->max_init_timeo) {
1351                                         asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
1352                                                 asoc->max_init_timeo;
1353                                 }
1354                                 asoc->init_cycle++;
1355                                 SCTP_DEBUG_PRINTK(
1356                                         "T1 INIT Timeout adjustment"
1357                                         " init_err_counter: %d"
1358                                         " cycle: %d"
1359                                         " timeout: %ld\n",
1360                                         asoc->init_err_counter,
1361                                         asoc->init_cycle,
1362                                         asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT]);
1363                         }
1364
1365                         sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1366                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1367                         break;
1368
1369                 case SCTP_CMD_COOKIEECHO_RESTART:
1370                         /* Do the needed accounting and updates
1371                          * associated with restarting an initialization
1372                          * timer. Only multiply the timeout by two if
1373                          * all transports have been tried at the current
1374                          * timeout.
1375                          */
1376                         asoc->init_err_counter++;
1377
1378                         asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] *= 2;
1379                         if (asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] >
1380                             asoc->max_init_timeo) {
1381                                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
1382                                         asoc->max_init_timeo;
1383                         }
1384                         SCTP_DEBUG_PRINTK(
1385                                 "T1 COOKIE Timeout adjustment"
1386                                 " init_err_counter: %d"
1387                                 " timeout: %ld\n",
1388                                 asoc->init_err_counter,
1389                                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE]);
1390
1391                         /* If we've sent any data bundled with
1392                          * COOKIE-ECHO we need to resend.
1393                          */
1394                         list_for_each_entry(t, &asoc->peer.transport_addr_list,
1395                                         transports) {
1396                                 sctp_retransmit_mark(&asoc->outqueue, t,
1397                                             SCTP_RTXR_T1_RTX);
1398                         }
1399
1400                         sctp_add_cmd_sf(commands,
1401                                         SCTP_CMD_TIMER_RESTART,
1402                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1403                         break;
1404
1405                 case SCTP_CMD_INIT_FAILED:
1406                         sctp_cmd_init_failed(commands, asoc, cmd->obj.err);
1407                         break;
1408
1409                 case SCTP_CMD_ASSOC_FAILED:
1410                         sctp_cmd_assoc_failed(commands, asoc, event_type,
1411                                               subtype, chunk, cmd->obj.err);
1412                         break;
1413
1414                 case SCTP_CMD_INIT_COUNTER_INC:
1415                         asoc->init_err_counter++;
1416                         break;
1417
1418                 case SCTP_CMD_INIT_COUNTER_RESET:
1419                         asoc->init_err_counter = 0;
1420                         asoc->init_cycle = 0;
1421                         break;
1422
1423                 case SCTP_CMD_REPORT_DUP:
1424                         sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1425                                              cmd->obj.u32);
1426                         break;
1427
1428                 case SCTP_CMD_REPORT_BAD_TAG:
1429                         SCTP_DEBUG_PRINTK("vtag mismatch!\n");
1430                         break;
1431
1432                 case SCTP_CMD_STRIKE:
1433                         /* Mark one strike against a transport.  */
1434                         sctp_do_8_2_transport_strike(asoc, cmd->obj.transport);
1435                         break;
1436
1437                 case SCTP_CMD_TRANSPORT_RESET:
1438                         t = cmd->obj.transport;
1439                         sctp_cmd_transport_reset(commands, asoc, t);
1440                         break;
1441
1442                 case SCTP_CMD_TRANSPORT_ON:
1443                         t = cmd->obj.transport;
1444                         sctp_cmd_transport_on(commands, asoc, t, chunk);
1445                         break;
1446
1447                 case SCTP_CMD_HB_TIMERS_START:
1448                         sctp_cmd_hb_timers_start(commands, asoc);
1449                         break;
1450
1451                 case SCTP_CMD_HB_TIMER_UPDATE:
1452                         t = cmd->obj.transport;
1453                         sctp_cmd_hb_timer_update(commands, t);
1454                         break;
1455
1456                 case SCTP_CMD_HB_TIMERS_STOP:
1457                         sctp_cmd_hb_timers_stop(commands, asoc);
1458                         break;
1459
1460                 case SCTP_CMD_REPORT_ERROR:
1461                         error = cmd->obj.error;
1462                         break;
1463
1464                 case SCTP_CMD_PROCESS_CTSN:
1465                         /* Dummy up a SACK for processing. */
1466                         sackh.cum_tsn_ack = cmd->obj.be32;
1467                         sackh.a_rwnd = 0;
1468                         sackh.num_gap_ack_blocks = 0;
1469                         sackh.num_dup_tsns = 0;
1470                         sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1471                                         SCTP_SACKH(&sackh));
1472                         break;
1473
1474                 case SCTP_CMD_DISCARD_PACKET:
1475                         /* We need to discard the whole packet.  */
1476                         chunk->pdiscard = 1;
1477                         break;
1478
1479                 case SCTP_CMD_RTO_PENDING:
1480                         t = cmd->obj.transport;
1481                         t->rto_pending = 1;
1482                         break;
1483
1484                 case SCTP_CMD_PART_DELIVER:
1485                         sctp_ulpq_partial_delivery(&asoc->ulpq, cmd->obj.ptr,
1486                                                    GFP_ATOMIC);
1487                         break;
1488
1489                 case SCTP_CMD_RENEGE:
1490                         sctp_ulpq_renege(&asoc->ulpq, cmd->obj.ptr,
1491                                          GFP_ATOMIC);
1492                         break;
1493
1494                 case SCTP_CMD_SETUP_T4:
1495                         sctp_cmd_setup_t4(commands, asoc, cmd->obj.ptr);
1496                         break;
1497
1498                 case SCTP_CMD_PROCESS_OPERR:
1499                         sctp_cmd_process_operr(commands, asoc, chunk);
1500                         break;
1501                 case SCTP_CMD_CLEAR_INIT_TAG:
1502                         asoc->peer.i.init_tag = 0;
1503                         break;
1504                 case SCTP_CMD_DEL_NON_PRIMARY:
1505                         sctp_cmd_del_non_primary(asoc);
1506                         break;
1507                 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1508                         sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1509                         break;
1510                 case SCTP_CMD_FORCE_PRIM_RETRAN:
1511                         t = asoc->peer.retran_path;
1512                         asoc->peer.retran_path = asoc->peer.primary_path;
1513                         error = sctp_outq_uncork(&asoc->outqueue);
1514                         local_cork = 0;
1515                         asoc->peer.retran_path = t;
1516                         break;
1517                 case SCTP_CMD_SET_SK_ERR:
1518                         sctp_cmd_set_sk_err(asoc, cmd->obj.error);
1519                         break;
1520                 case SCTP_CMD_ASSOC_CHANGE:
1521                         sctp_cmd_assoc_change(commands, asoc,
1522                                               cmd->obj.u8);
1523                         break;
1524                 case SCTP_CMD_ADAPTATION_IND:
1525                         sctp_cmd_adaptation_ind(commands, asoc);
1526                         break;
1527
1528                 case SCTP_CMD_ASSOC_SHKEY:
1529                         error = sctp_auth_asoc_init_active_key(asoc,
1530                                                 GFP_ATOMIC);
1531                         break;
1532                 case SCTP_CMD_UPDATE_INITTAG:
1533                         asoc->peer.i.init_tag = cmd->obj.u32;
1534                         break;
1535
1536                 default:
1537                         printk(KERN_WARNING "Impossible command: %u, %p\n",
1538                                cmd->verb, cmd->obj.ptr);
1539                         break;
1540                 }
1541
1542                 if (error)
1543                         break;
1544         }
1545
1546 out:
1547         if (local_cork)
1548                 sctp_outq_uncork(&asoc->outqueue);
1549         return error;
1550 nomem:
1551         error = -ENOMEM;
1552         goto out;
1553 }
1554