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                 asoc->peer.sack_cnt++;
 194
 195                 /* Set the SACK delay timeout based on the
 196                  * SACK delay for the last transport
 197                  * data was received from, or the default
 198                  * for the association.
 199                  */
 200                 if (trans) {
 201                         /* We will need a SACK for the next packet.  */
 202                         if (asoc->peer.sack_cnt >= trans->sackfreq - 1)
 203                                 asoc->peer.sack_needed = 1;
 204
 205                         asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
 206                                 trans->sackdelay;
 207                 } else {
 208                         /* We will need a SACK for the next packet.  */
 209                         if (asoc->peer.sack_cnt >= asoc->sackfreq - 1)
 210                                 asoc->peer.sack_needed = 1;
 211
 212                         asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
 213                                 asoc->sackdelay;
 214                 }
 215
 216                 /* Restart the SACK timer. */
 217                 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
 218                                 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
 219         } else {
 220                 if (asoc->a_rwnd > asoc->rwnd)
 221                         asoc->a_rwnd = asoc->rwnd;
 222                 sack = sctp_make_sack(asoc);
 223                 if (!sack)
 224                         goto nomem;
 225
 226                 asoc->peer.sack_needed = 0;
 227                 asoc->peer.sack_cnt = 0;
 228
 229                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(sack));
 230
 231                 /* Stop the SACK timer.  */
 232                 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
 233                                 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
 234         }
 235
 236         return error;
 237 nomem:
 238         error = -ENOMEM;
 239         return error;
 240 }
 241
 242 /* When the T3-RTX timer expires, it calls this function to create the
 243  * relevant state machine event.
 244  */
 245 void sctp_generate_t3_rtx_event(unsigned long peer)
 246 {
 247         int error;
 248         struct sctp_transport *transport = (struct sctp_transport *) peer;
 249         struct sctp_association *asoc = transport->asoc;
 250
 251         /* Check whether a task is in the sock.  */
 252
 253         sctp_bh_lock_sock(asoc->base.sk);
 254         if (sock_owned_by_user(asoc->base.sk)) {
 255                 SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __func__);
 256
 257                 /* Try again later.  */
 258                 if (!mod_timer(&transport->T3_rtx_timer, jiffies + (HZ/20)))
 259                         sctp_transport_hold(transport);
 260                 goto out_unlock;
 261         }
 262
 263         /* Is this transport really dead and just waiting around for
 264          * the timer to let go of the reference?
 265          */
 266         if (transport->dead)
 267                 goto out_unlock;
 268
 269         /* Run through the state machine.  */
 270         error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
 271                            SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX),
 272                            asoc->state,
 273                            asoc->ep, asoc,
 274                            transport, GFP_ATOMIC);
 275
 276         if (error)
 277                 asoc->base.sk->sk_err = -error;
 278
 279 out_unlock:
 280         sctp_bh_unlock_sock(asoc->base.sk);
 281         sctp_transport_put(transport);
 282 }
 283
 284 /* This is a sa interface for producing timeout events.  It works
 285  * for timeouts which use the association as their parameter.
 286  */
 287 static void sctp_generate_timeout_event(struct sctp_association *asoc,
 288                                         sctp_event_timeout_t timeout_type)
 289 {
 290         int error = 0;
 291
 292         sctp_bh_lock_sock(asoc->base.sk);
 293         if (sock_owned_by_user(asoc->base.sk)) {
 294                 SCTP_DEBUG_PRINTK("%s:Sock is busy: timer %d\n",
 295                                   __func__,
 296                                   timeout_type);
 297
 298                 /* Try again later.  */
 299                 if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20)))
 300                         sctp_association_hold(asoc);
 301                 goto out_unlock;
 302         }
 303
 304         /* Is this association really dead and just waiting around for
 305          * the timer to let go of the reference?
 306          */
 307         if (asoc->base.dead)
 308                 goto out_unlock;
 309
 310         /* Run through the state machine.  */
 311         error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
 312                            SCTP_ST_TIMEOUT(timeout_type),
 313                            asoc->state, asoc->ep, asoc,
 314                            (void *)timeout_type, GFP_ATOMIC);
 315
 316         if (error)
 317                 asoc->base.sk->sk_err = -error;
 318
 319 out_unlock:
 320         sctp_bh_unlock_sock(asoc->base.sk);
 321         sctp_association_put(asoc);
 322 }
 323
 324 static void sctp_generate_t1_cookie_event(unsigned long data)
 325 {
 326         struct sctp_association *asoc = (struct sctp_association *) data;
 327         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
 328 }
 329
 330 static void sctp_generate_t1_init_event(unsigned long data)
 331 {
 332         struct sctp_association *asoc = (struct sctp_association *) data;
 333         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
 334 }
 335
 336 static void sctp_generate_t2_shutdown_event(unsigned long data)
 337 {
 338         struct sctp_association *asoc = (struct sctp_association *) data;
 339         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
 340 }
 341
 342 static void sctp_generate_t4_rto_event(unsigned long data)
 343 {
 344         struct sctp_association *asoc = (struct sctp_association *) data;
 345         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
 346 }
 347
 348 static void sctp_generate_t5_shutdown_guard_event(unsigned long data)
 349 {
 350         struct sctp_association *asoc = (struct sctp_association *)data;
 351         sctp_generate_timeout_event(asoc,
 352                                     SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);
 353
 354 } /* sctp_generate_t5_shutdown_guard_event() */
 355
 356 static void sctp_generate_autoclose_event(unsigned long data)
 357 {
 358         struct sctp_association *asoc = (struct sctp_association *) data;
 359         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE);
 360 }
 361
 362 /* Generate a heart beat event.  If the sock is busy, reschedule.   Make
 363  * sure that the transport is still valid.
 364  */
 365 void sctp_generate_heartbeat_event(unsigned long data)
 366 {
 367         int error = 0;
 368         struct sctp_transport *transport = (struct sctp_transport *) data;
 369         struct sctp_association *asoc = transport->asoc;
 370
 371         sctp_bh_lock_sock(asoc->base.sk);
 372         if (sock_owned_by_user(asoc->base.sk)) {
 373                 SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __func__);
 374
 375                 /* Try again later.  */
 376                 if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20)))
 377                         sctp_transport_hold(transport);
 378                 goto out_unlock;
 379         }
 380
 381         /* Is this structure just waiting around for us to actually
 382          * get destroyed?
 383          */
 384         if (transport->dead)
 385                 goto out_unlock;
 386
 387         error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
 388                            SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
 389                            asoc->state, asoc->ep, asoc,
 390                            transport, GFP_ATOMIC);
 391
 392          if (error)
 393                  asoc->base.sk->sk_err = -error;
 394
 395 out_unlock:
 396         sctp_bh_unlock_sock(asoc->base.sk);
 397         sctp_transport_put(transport);
 398 }
 399
 400 /* Inject a SACK Timeout event into the state machine.  */
 401 static void sctp_generate_sack_event(unsigned long data)
 402 {
 403         struct sctp_association *asoc = (struct sctp_association *) data;
 404         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
 405 }
 406
 407 sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
 408         NULL,
 409         sctp_generate_t1_cookie_event,
 410         sctp_generate_t1_init_event,
 411         sctp_generate_t2_shutdown_event,
 412         NULL,
 413         sctp_generate_t4_rto_event,
 414         sctp_generate_t5_shutdown_guard_event,
 415         NULL,
 416         sctp_generate_sack_event,
 417         sctp_generate_autoclose_event,
 418 };
 419
 420
 421 /* RFC 2960 8.2 Path Failure Detection
 422  *
 423  * When its peer endpoint is multi-homed, an endpoint should keep a
 424  * error counter for each of the destination transport addresses of the
 425  * peer endpoint.
 426  *
 427  * Each time the T3-rtx timer expires on any address, or when a
 428  * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
 429  * the error counter of that destination address will be incremented.
 430  * When the value in the error counter exceeds the protocol parameter
 431  * 'Path.Max.Retrans' of that destination address, the endpoint should
 432  * mark the destination transport address as inactive, and a
 433  * notification SHOULD be sent to the upper layer.
 434  *
 435  */
 436 static void sctp_do_8_2_transport_strike(struct sctp_association *asoc,
 437                                          struct sctp_transport *transport)
 438 {
 439         /* The check for association's overall error counter exceeding the
 440          * threshold is done in the state function.
 441          */
 442         /* When probing UNCONFIRMED addresses, the association overall
 443          * error count is NOT incremented
 444          */
 445         if (transport->state != SCTP_UNCONFIRMED)
 446                 asoc->overall_error_count++;
 447
 448         if (transport->state != SCTP_INACTIVE &&
 449             (transport->error_count++ >= transport->pathmaxrxt)) {
 450                 SCTP_DEBUG_PRINTK_IPADDR("transport_strike:association %p",
 451                                          " transport IP: port:%d failed.\n",
 452                                          asoc,
 453                                          (&transport->ipaddr),
 454                                          ntohs(transport->ipaddr.v4.sin_port));
 455                 sctp_assoc_control_transport(asoc, transport,
 456                                              SCTP_TRANSPORT_DOWN,
 457                                              SCTP_FAILED_THRESHOLD);
 458         }
 459
 460         /* E2) For the destination address for which the timer
 461          * expires, set RTO <- RTO * 2 ("back off the timer").  The
 462          * maximum value discussed in rule C7 above (RTO.max) may be
 463          * used to provide an upper bound to this doubling operation.
 464          *
 465          * Special Case:  the first HB doesn't trigger exponential backoff.
 466          * The first unacknowleged HB triggers it.  We do this with a flag
 467          * that indicates that we have an outstanding HB.
 468          */
 469         if (transport->hb_sent) {
 470                 transport->last_rto = transport->rto;
 471                 transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
 472         }
 473 }
 474
 475 /* Worker routine to handle INIT command failure.  */
 476 static void sctp_cmd_init_failed(sctp_cmd_seq_t *commands,
 477                                  struct sctp_association *asoc,
 478                                  unsigned error)
 479 {
 480         struct sctp_ulpevent *event;
 481
 482         event = sctp_ulpevent_make_assoc_change(asoc,0, SCTP_CANT_STR_ASSOC,
 483                                                 (__u16)error, 0, 0, NULL,
 484                                                 GFP_ATOMIC);
 485
 486         if (event)
 487                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 488                                 SCTP_ULPEVENT(event));
 489
 490         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 491                         SCTP_STATE(SCTP_STATE_CLOSED));
 492
 493         /* SEND_FAILED sent later when cleaning up the association. */
 494         asoc->outqueue.error = error;
 495         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 496 }
 497
 498 /* Worker routine to handle SCTP_CMD_ASSOC_FAILED.  */
 499 static void sctp_cmd_assoc_failed(sctp_cmd_seq_t *commands,
 500                                   struct sctp_association *asoc,
 501                                   sctp_event_t event_type,
 502                                   sctp_subtype_t subtype,
 503                                   struct sctp_chunk *chunk,
 504                                   unsigned error)
 505 {
 506         struct sctp_ulpevent *event;
 507
 508         /* Cancel any partial delivery in progress. */
 509         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
 510
 511         if (event_type == SCTP_EVENT_T_CHUNK && subtype.chunk == SCTP_CID_ABORT)
 512                 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
 513                                                 (__u16)error, 0, 0, chunk,
 514                                                 GFP_ATOMIC);
 515         else
 516                 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
 517                                                 (__u16)error, 0, 0, NULL,
 518                                                 GFP_ATOMIC);
 519         if (event)
 520                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 521                                 SCTP_ULPEVENT(event));
 522
 523         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 524                         SCTP_STATE(SCTP_STATE_CLOSED));
 525
 526         /* SEND_FAILED sent later when cleaning up the association. */
 527         asoc->outqueue.error = error;
 528         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 529 }
 530
 531 /* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
 532  * inside the cookie.  In reality, this is only used for INIT-ACK processing
 533  * since all other cases use "temporary" associations and can do all
 534  * their work in statefuns directly.
 535  */
 536 static int sctp_cmd_process_init(sctp_cmd_seq_t *commands,
 537                                  struct sctp_association *asoc,
 538                                  struct sctp_chunk *chunk,
 539                                  sctp_init_chunk_t *peer_init,
 540                                  gfp_t gfp)
 541 {
 542         int error;
 543
 544         /* We only process the init as a sideeffect in a single
 545          * case.   This is when we process the INIT-ACK.   If we
 546          * fail during INIT processing (due to malloc problems),
 547          * just return the error and stop processing the stack.
 548          */
 549         if (!sctp_process_init(asoc, chunk->chunk_hdr->type,
 550                                sctp_source(chunk), peer_init, gfp))
 551                 error = -ENOMEM;
 552         else
 553                 error = 0;
 554
 555         return error;
 556 }
 557
 558 /* Helper function to break out starting up of heartbeat timers.  */
 559 static void sctp_cmd_hb_timers_start(sctp_cmd_seq_t *cmds,
 560                                      struct sctp_association *asoc)
 561 {
 562         struct sctp_transport *t;
 563
 564         /* Start a heartbeat timer for each transport on the association.
 565          * hold a reference on the transport to make sure none of
 566          * the needed data structures go away.
 567          */
 568         list_for_each_entry(t, &asoc->peer.transport_addr_list, transports) {
 569
 570                 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 571                         sctp_transport_hold(t);
 572         }
 573 }
 574
 575 static void sctp_cmd_hb_timers_stop(sctp_cmd_seq_t *cmds,
 576                                     struct sctp_association *asoc)
 577 {
 578         struct sctp_transport *t;
 579
 580         /* Stop all heartbeat timers. */
 581
 582         list_for_each_entry(t, &asoc->peer.transport_addr_list,
 583                         transports) {
 584                 if (del_timer(&t->hb_timer))
 585                         sctp_transport_put(t);
 586         }
 587 }
 588
 589 /* Helper function to stop any pending T3-RTX timers */
 590 static void sctp_cmd_t3_rtx_timers_stop(sctp_cmd_seq_t *cmds,
 591                                         struct sctp_association *asoc)
 592 {
 593         struct sctp_transport *t;
 594
 595         list_for_each_entry(t, &asoc->peer.transport_addr_list,
 596                         transports) {
 597                 if (timer_pending(&t->T3_rtx_timer) &&
 598                     del_timer(&t->T3_rtx_timer)) {
 599                         sctp_transport_put(t);
 600                 }
 601         }
 602 }
 603
 604
 605 /* Helper function to update the heartbeat timer. */
 606 static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
 607                                      struct sctp_transport *t)
 608 {
 609         /* Update the heartbeat timer.  */
 610         if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 611                 sctp_transport_hold(t);
 612 }
 613
 614 /* Helper function to handle the reception of an HEARTBEAT ACK.  */
 615 static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds,
 616                                   struct sctp_association *asoc,
 617                                   struct sctp_transport *t,
 618                                   struct sctp_chunk *chunk)
 619 {
 620         sctp_sender_hb_info_t *hbinfo;
 621
 622         /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
 623          * HEARTBEAT should clear the error counter of the destination
 624          * transport address to which the HEARTBEAT was sent.
 625          * The association's overall error count is also cleared.
 626          */
 627         t->error_count = 0;
 628         t->asoc->overall_error_count = 0;
 629
 630         /* Clear the hb_sent flag to signal that we had a good
 631          * acknowledgement.
 632          */
 633         t->hb_sent = 0;
 634
 635         /* Mark the destination transport address as active if it is not so
 636          * marked.
 637          */
 638         if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED))
 639                 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
 640                                              SCTP_HEARTBEAT_SUCCESS);
 641
 642         /* The receiver of the HEARTBEAT ACK should also perform an
 643          * RTT measurement for that destination transport address
 644          * using the time value carried in the HEARTBEAT ACK chunk.
 645          * If the transport's rto_pending variable has been cleared,
 646          * it was most likely due to a retransmit.  However, we want
 647          * to re-enable it to properly update the rto.
 648          */
 649         if (t->rto_pending == 0)
 650                 t->rto_pending = 1;
 651
 652         hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
 653         sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
 654
 655         /* Update the heartbeat timer.  */
 656         if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 657                 sctp_transport_hold(t);
 658 }
 659
 660 /* Helper function to do a transport reset at the expiry of the hearbeat
 661  * timer.
 662  */
 663 static void sctp_cmd_transport_reset(sctp_cmd_seq_t *cmds,
 664                                      struct sctp_association *asoc,
 665                                      struct sctp_transport *t)
 666 {
 667         sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
 668
 669         /* Mark one strike against a transport.  */
 670         sctp_do_8_2_transport_strike(asoc, t);
 671
 672         t->hb_sent = 1;
 673 }
 674
 675 /* Helper function to process the process SACK command.  */
 676 static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds,
 677                                  struct sctp_association *asoc,
 678                                  struct sctp_sackhdr *sackh)
 679 {
 680         int err = 0;
 681
 682         if (sctp_outq_sack(&asoc->outqueue, sackh)) {
 683                 /* There are no more TSNs awaiting SACK.  */
 684                 err = sctp_do_sm(SCTP_EVENT_T_OTHER,
 685                                  SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
 686                                  asoc->state, asoc->ep, asoc, NULL,
 687                                  GFP_ATOMIC);
 688         }
 689
 690         return err;
 691 }
 692
 693 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
 694  * the transport for a shutdown chunk.
 695  */
 696 static void sctp_cmd_setup_t2(sctp_cmd_seq_t *cmds,
 697                               struct sctp_association *asoc,
 698                               struct sctp_chunk *chunk)
 699 {
 700         struct sctp_transport *t;
 701
 702         t = sctp_assoc_choose_shutdown_transport(asoc);
 703         asoc->shutdown_last_sent_to = t;
 704         asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
 705         chunk->transport = t;
 706 }
 707
 708 /* Helper function to change the state of an association. */
 709 static void sctp_cmd_new_state(sctp_cmd_seq_t *cmds,
 710                                struct sctp_association *asoc,
 711                                sctp_state_t state)
 712 {
 713         struct sock *sk = asoc->base.sk;
 714
 715         asoc->state = state;
 716
 717         SCTP_DEBUG_PRINTK("sctp_cmd_new_state: asoc %p[%s]\n",
 718                           asoc, sctp_state_tbl[state]);
 719
 720         if (sctp_style(sk, TCP)) {
 721                 /* Change the sk->sk_state of a TCP-style socket that has
 722                  * sucessfully completed a connect() call.
 723                  */
 724                 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
 725                         sk->sk_state = SCTP_SS_ESTABLISHED;
 726
 727                 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
 728                 if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
 729                     sctp_sstate(sk, ESTABLISHED))
 730                         sk->sk_shutdown |= RCV_SHUTDOWN;
 731         }
 732
 733         if (sctp_state(asoc, COOKIE_WAIT)) {
 734                 /* Reset init timeouts since they may have been
 735                  * increased due to timer expirations.
 736                  */
 737                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
 738                                                 asoc->rto_initial;
 739                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
 740                                                 asoc->rto_initial;
 741         }
 742
 743         if (sctp_state(asoc, ESTABLISHED) ||
 744             sctp_state(asoc, CLOSED) ||
 745             sctp_state(asoc, SHUTDOWN_RECEIVED)) {
 746                 /* Wake up any processes waiting in the asoc's wait queue in
 747                  * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
 748                  */
 749                 if (waitqueue_active(&asoc->wait))
 750                         wake_up_interruptible(&asoc->wait);
 751
 752                 /* Wake up any processes waiting in the sk's sleep queue of
 753                  * a TCP-style or UDP-style peeled-off socket in
 754                  * sctp_wait_for_accept() or sctp_wait_for_packet().
 755                  * For a UDP-style socket, the waiters are woken up by the
 756                  * notifications.
 757                  */
 758                 if (!sctp_style(sk, UDP))
 759                         sk->sk_state_change(sk);
 760         }
 761 }
 762
 763 /* Helper function to delete an association. */
 764 static void sctp_cmd_delete_tcb(sctp_cmd_seq_t *cmds,
 765                                 struct sctp_association *asoc)
 766 {
 767         struct sock *sk = asoc->base.sk;
 768
 769         /* If it is a non-temporary association belonging to a TCP-style
 770          * listening socket that is not closed, do not free it so that accept()
 771          * can pick it up later.
 772          */
 773         if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
 774             (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
 775                 return;
 776
 777         sctp_unhash_established(asoc);
 778         sctp_association_free(asoc);
 779 }
 780
 781 /*
 782  * ADDIP Section 4.1 ASCONF Chunk Procedures
 783  * A4) Start a T-4 RTO timer, using the RTO value of the selected
 784  * destination address (we use active path instead of primary path just
 785  * because primary path may be inactive.
 786  */
 787 static void sctp_cmd_setup_t4(sctp_cmd_seq_t *cmds,
 788                                 struct sctp_association *asoc,
 789                                 struct sctp_chunk *chunk)
 790 {
 791         struct sctp_transport *t;
 792
 793         t = asoc->peer.active_path;
 794         asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
 795         chunk->transport = t;
 796 }
 797
 798 /* Process an incoming Operation Error Chunk. */
 799 static void sctp_cmd_process_operr(sctp_cmd_seq_t *cmds,
 800                                    struct sctp_association *asoc,
 801                                    struct sctp_chunk *chunk)
 802 {
 803         struct sctp_operr_chunk *operr_chunk;
 804         struct sctp_errhdr *err_hdr;
 805
 806         operr_chunk = (struct sctp_operr_chunk *)chunk->chunk_hdr;
 807         err_hdr = &operr_chunk->err_hdr;
 808
 809         switch (err_hdr->cause) {
 810         case SCTP_ERROR_UNKNOWN_CHUNK:
 811         {
 812                 struct sctp_chunkhdr *unk_chunk_hdr;
 813
 814                 unk_chunk_hdr = (struct sctp_chunkhdr *)err_hdr->variable;
 815                 switch (unk_chunk_hdr->type) {
 816                 /* ADDIP 4.1 A9) If the peer responds to an ASCONF with an
 817                  * ERROR chunk reporting that it did not recognized the ASCONF
 818                  * chunk type, the sender of the ASCONF MUST NOT send any
 819                  * further ASCONF chunks and MUST stop its T-4 timer.
 820                  */
 821                 case SCTP_CID_ASCONF:
 822                         asoc->peer.asconf_capable = 0;
 823                         sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
 824                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
 825                         break;
 826                 default:
 827                         break;
 828                 }
 829                 break;
 830         }
 831         default:
 832                 break;
 833         }
 834 }
 835
 836 /* Process variable FWDTSN chunk information. */
 837 static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq,
 838                                     struct sctp_chunk *chunk)
 839 {
 840         struct sctp_fwdtsn_skip *skip;
 841         /* Walk through all the skipped SSNs */
 842         sctp_walk_fwdtsn(skip, chunk) {
 843                 sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
 844         }
 845
 846         return;
 847 }
 848
 849 /* Helper function to remove the association non-primary peer
 850  * transports.
 851  */
 852 static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
 853 {
 854         struct sctp_transport *t;
 855         struct list_head *pos;
 856         struct list_head *temp;
 857
 858         list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
 859                 t = list_entry(pos, struct sctp_transport, transports);
 860                 if (!sctp_cmp_addr_exact(&t->ipaddr,
 861                                          &asoc->peer.primary_addr)) {
 862                         sctp_assoc_del_peer(asoc, &t->ipaddr);
 863                 }
 864         }
 865
 866         return;
 867 }
 868
 869 /* Helper function to set sk_err on a 1-1 style socket. */
 870 static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
 871 {
 872         struct sock *sk = asoc->base.sk;
 873
 874         if (!sctp_style(sk, UDP))
 875                 sk->sk_err = error;
 876 }
 877
 878 /* Helper function to generate an association change event */
 879 static void sctp_cmd_assoc_change(sctp_cmd_seq_t *commands,
 880                                  struct sctp_association *asoc,
 881                                  u8 state)
 882 {
 883         struct sctp_ulpevent *ev;
 884
 885         ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0,
 886                                             asoc->c.sinit_num_ostreams,
 887                                             asoc->c.sinit_max_instreams,
 888                                             NULL, GFP_ATOMIC);
 889         if (ev)
 890                 sctp_ulpq_tail_event(&asoc->ulpq, ev);
 891 }
 892
 893 /* Helper function to generate an adaptation indication event */
 894 static void sctp_cmd_adaptation_ind(sctp_cmd_seq_t *commands,
 895                                     struct sctp_association *asoc)
 896 {
 897         struct sctp_ulpevent *ev;
 898
 899         ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
 900
 901         if (ev)
 902                 sctp_ulpq_tail_event(&asoc->ulpq, ev);
 903 }
 904
 905
 906 static void sctp_cmd_t1_timer_update(struct sctp_association *asoc,
 907                                     sctp_event_timeout_t timer,
 908                                     char *name)
 909 {
 910         struct sctp_transport *t;
 911
 912         t = asoc->init_last_sent_to;
 913         asoc->init_err_counter++;
 914
 915         if (t->init_sent_count > (asoc->init_cycle + 1)) {
 916                 asoc->timeouts[timer] *= 2;
 917                 if (asoc->timeouts[timer] > asoc->max_init_timeo) {
 918                         asoc->timeouts[timer] = asoc->max_init_timeo;
 919                 }
 920                 asoc->init_cycle++;
 921                 SCTP_DEBUG_PRINTK(
 922                         "T1 %s Timeout adjustment"
 923                         " init_err_counter: %d"
 924                         " cycle: %d"
 925                         " timeout: %ld\n",
 926                         name,
 927                         asoc->init_err_counter,
 928                         asoc->init_cycle,
 929                         asoc->timeouts[timer]);
 930         }
 931
 932 }
 933
 934 /* These three macros allow us to pull the debugging code out of the
 935  * main flow of sctp_do_sm() to keep attention focused on the real
 936  * functionality there.
 937  */
 938 #define DEBUG_PRE \
 939         SCTP_DEBUG_PRINTK("sctp_do_sm prefn: " \
 940                           "ep %p, %s, %s, asoc %p[%s], %s\n", \
 941                           ep, sctp_evttype_tbl[event_type], \
 942                           (*debug_fn)(subtype), asoc, \
 943                           sctp_state_tbl[state], state_fn->name)
 944
 945 #define DEBUG_POST \
 946         SCTP_DEBUG_PRINTK("sctp_do_sm postfn: " \
 947                           "asoc %p, status: %s\n", \
 948                           asoc, sctp_status_tbl[status])
 949
 950 #define DEBUG_POST_SFX \
 951         SCTP_DEBUG_PRINTK("sctp_do_sm post sfx: error %d, asoc %p[%s]\n", \
 952                           error, asoc, \
 953                           sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
 954                           sctp_assoc2id(asoc)))?asoc->state:SCTP_STATE_CLOSED])
 955
 956 /*
 957  * This is the master state machine processing function.
 958  *
 959  * If you want to understand all of lksctp, this is a
 960  * good place to start.
 961  */
 962 int sctp_do_sm(sctp_event_t event_type, sctp_subtype_t subtype,
 963                sctp_state_t state,
 964                struct sctp_endpoint *ep,
 965                struct sctp_association *asoc,
 966                void *event_arg,
 967                gfp_t gfp)
 968 {
 969         sctp_cmd_seq_t commands;
 970         const sctp_sm_table_entry_t *state_fn;
 971         sctp_disposition_t status;
 972         int error = 0;
 973         typedef const char *(printfn_t)(sctp_subtype_t);
 974
 975         static printfn_t *table[] = {
 976                 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
 977         };
 978         printfn_t *debug_fn  __attribute__ ((unused)) = table[event_type];
 979
 980         /* Look up the state function, run it, and then process the
 981          * side effects.  These three steps are the heart of lksctp.
 982          */
 983         state_fn = sctp_sm_lookup_event(event_type, state, subtype);
 984
 985         sctp_init_cmd_seq(&commands);
 986
 987         DEBUG_PRE;
 988         status = (*state_fn->fn)(ep, asoc, subtype, event_arg, &commands);
 989         DEBUG_POST;
 990
 991         error = sctp_side_effects(event_type, subtype, state,
 992                                   ep, asoc, event_arg, status,
 993                                   &commands, gfp);
 994         DEBUG_POST_SFX;
 995
 996         return error;
 997 }
 998
 999 #undef DEBUG_PRE
1000 #undef DEBUG_POST
1001
1002 /*****************************************************************
1003  * This the master state function side effect processing function.
1004  *****************************************************************/
1005 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
1006                              sctp_state_t state,
1007                              struct sctp_endpoint *ep,
1008                              struct sctp_association *asoc,
1009                              void *event_arg,
1010                              sctp_disposition_t status,
1011                              sctp_cmd_seq_t *commands,
1012                              gfp_t gfp)
1013 {
1014         int error;
1015
1016         /* FIXME - Most of the dispositions left today would be categorized
1017          * as "exceptional" dispositions.  For those dispositions, it
1018          * may not be proper to run through any of the commands at all.
1019          * For example, the command interpreter might be run only with
1020          * disposition SCTP_DISPOSITION_CONSUME.
1021          */
1022         if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
1023                                                ep, asoc,
1024                                                event_arg, status,
1025                                                commands, gfp)))
1026                 goto bail;
1027
1028         switch (status) {
1029         case SCTP_DISPOSITION_DISCARD:
1030                 SCTP_DEBUG_PRINTK("Ignored sctp protocol event - state %d, "
1031                                   "event_type %d, event_id %d\n",
1032                                   state, event_type, subtype.chunk);
1033                 break;
1034
1035         case SCTP_DISPOSITION_NOMEM:
1036                 /* We ran out of memory, so we need to discard this
1037                  * packet.
1038                  */
1039                 /* BUG--we should now recover some memory, probably by
1040                  * reneging...
1041                  */
1042                 error = -ENOMEM;
1043                 break;
1044
1045         case SCTP_DISPOSITION_DELETE_TCB:
1046                 /* This should now be a command. */
1047                 break;
1048
1049         case SCTP_DISPOSITION_CONSUME:
1050         case SCTP_DISPOSITION_ABORT:
1051                 /*
1052                  * We should no longer have much work to do here as the
1053                  * real work has been done as explicit commands above.
1054                  */
1055                 break;
1056
1057         case SCTP_DISPOSITION_VIOLATION:
1058                 if (net_ratelimit())
1059                         printk(KERN_ERR "sctp protocol violation state %d "
1060                                "chunkid %d\n", state, subtype.chunk);
1061                 break;
1062
1063         case SCTP_DISPOSITION_NOT_IMPL:
1064                 printk(KERN_WARNING "sctp unimplemented feature in state %d, "
1065                        "event_type %d, event_id %d\n",
1066                        state, event_type, subtype.chunk);
1067                 break;
1068
1069         case SCTP_DISPOSITION_BUG:
1070                 printk(KERN_ERR "sctp bug in state %d, "
1071                        "event_type %d, event_id %d\n",
1072                        state, event_type, subtype.chunk);
1073                 BUG();
1074                 break;
1075
1076         default:
1077                 printk(KERN_ERR "sctp impossible disposition %d "
1078                        "in state %d, event_type %d, event_id %d\n",
1079                        status, state, event_type, subtype.chunk);
1080                 BUG();
1081                 break;
1082         }
1083
1084 bail:
1085         return error;
1086 }
1087
1088 /********************************************************************
1089  * 2nd Level Abstractions
1090  ********************************************************************/
1091
1092 /* This is the side-effect interpreter.  */
1093 static int sctp_cmd_interpreter(sctp_event_t event_type,
1094                                 sctp_subtype_t subtype,
1095                                 sctp_state_t state,
1096                                 struct sctp_endpoint *ep,
1097                                 struct sctp_association *asoc,
1098                                 void *event_arg,
1099                                 sctp_disposition_t status,
1100                                 sctp_cmd_seq_t *commands,
1101                                 gfp_t gfp)
1102 {
1103         int error = 0;
1104         int force;
1105         sctp_cmd_t *cmd;
1106         struct sctp_chunk *new_obj;
1107         struct sctp_chunk *chunk = NULL;
1108         struct sctp_packet *packet;
1109         struct timer_list *timer;
1110         unsigned long timeout;
1111         struct sctp_transport *t;
1112         struct sctp_sackhdr sackh;
1113         int local_cork = 0;
1114
1115         if (SCTP_EVENT_T_TIMEOUT != event_type)
1116                 chunk = (struct sctp_chunk *) event_arg;
1117
1118         /* Note:  This whole file is a huge candidate for rework.
1119          * For example, each command could either have its own handler, so
1120          * the loop would look like:
1121          *     while (cmds)
1122          *         cmd->handle(x, y, z)
1123          * --jgrimm
1124          */
1125         while (NULL != (cmd = sctp_next_cmd(commands))) {
1126                 switch (cmd->verb) {
1127                 case SCTP_CMD_NOP:
1128                         /* Do nothing. */
1129                         break;
1130
1131                 case SCTP_CMD_NEW_ASOC:
1132                         /* Register a new association.  */
1133                         if (local_cork) {
1134                                 sctp_outq_uncork(&asoc->outqueue);
1135                                 local_cork = 0;
1136                         }
1137                         asoc = cmd->obj.ptr;
1138                         /* Register with the endpoint.  */
1139                         sctp_endpoint_add_asoc(ep, asoc);
1140                         sctp_hash_established(asoc);
1141                         break;
1142
1143                 case SCTP_CMD_UPDATE_ASSOC:
1144                        sctp_assoc_update(asoc, cmd->obj.ptr);
1145                        break;
1146
1147                 case SCTP_CMD_PURGE_OUTQUEUE:
1148                        sctp_outq_teardown(&asoc->outqueue);
1149                        break;
1150
1151                 case SCTP_CMD_DELETE_TCB:
1152                         if (local_cork) {
1153                                 sctp_outq_uncork(&asoc->outqueue);
1154                                 local_cork = 0;
1155                         }
1156                         /* Delete the current association.  */
1157                         sctp_cmd_delete_tcb(commands, asoc);
1158                         asoc = NULL;
1159                         break;
1160
1161                 case SCTP_CMD_NEW_STATE:
1162                         /* Enter a new state.  */
1163                         sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1164                         break;
1165
1166                 case SCTP_CMD_REPORT_TSN:
1167                         /* Record the arrival of a TSN.  */
1168                         error = sctp_tsnmap_mark(&asoc->peer.tsn_map,
1169                                                  cmd->obj.u32);
1170                         break;
1171
1172                 case SCTP_CMD_REPORT_FWDTSN:
1173                         /* Move the Cumulattive TSN Ack ahead. */
1174                         sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32);
1175
1176                         /* purge the fragmentation queue */
1177                         sctp_ulpq_reasm_flushtsn(&asoc->ulpq, cmd->obj.u32);
1178
1179                         /* Abort any in progress partial delivery. */
1180                         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
1181                         break;
1182
1183                 case SCTP_CMD_PROCESS_FWDTSN:
1184                         sctp_cmd_process_fwdtsn(&asoc->ulpq, cmd->obj.ptr);
1185                         break;
1186
1187                 case SCTP_CMD_GEN_SACK:
1188                         /* Generate a Selective ACK.
1189                          * The argument tells us whether to just count
1190                          * the packet and MAYBE generate a SACK, or
1191                          * force a SACK out.
1192                          */
1193                         force = cmd->obj.i32;
1194                         error = sctp_gen_sack(asoc, force, commands);
1195                         break;
1196
1197                 case SCTP_CMD_PROCESS_SACK:
1198                         /* Process an inbound SACK.  */
1199                         error = sctp_cmd_process_sack(commands, asoc,
1200                                                       cmd->obj.ptr);
1201                         break;
1202
1203                 case SCTP_CMD_GEN_INIT_ACK:
1204                         /* Generate an INIT ACK chunk.  */
1205                         new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1206                                                      0);
1207                         if (!new_obj)
1208                                 goto nomem;
1209
1210                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1211                                         SCTP_CHUNK(new_obj));
1212                         break;
1213
1214                 case SCTP_CMD_PEER_INIT:
1215                         /* Process a unified INIT from the peer.
1216                          * Note: Only used during INIT-ACK processing.  If
1217                          * there is an error just return to the outter
1218                          * layer which will bail.
1219                          */
1220                         error = sctp_cmd_process_init(commands, asoc, chunk,
1221                                                       cmd->obj.ptr, gfp);
1222                         break;
1223
1224                 case SCTP_CMD_GEN_COOKIE_ECHO:
1225                         /* Generate a COOKIE ECHO chunk.  */
1226                         new_obj = sctp_make_cookie_echo(asoc, chunk);
1227                         if (!new_obj) {
1228                                 if (cmd->obj.ptr)
1229                                         sctp_chunk_free(cmd->obj.ptr);
1230                                 goto nomem;
1231                         }
1232                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1233                                         SCTP_CHUNK(new_obj));
1234
1235                         /* If there is an ERROR chunk to be sent along with
1236                          * the COOKIE_ECHO, send it, too.
1237                          */
1238                         if (cmd->obj.ptr)
1239                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1240                                                 SCTP_CHUNK(cmd->obj.ptr));
1241
1242                         if (new_obj->transport) {
1243                                 new_obj->transport->init_sent_count++;
1244                                 asoc->init_last_sent_to = new_obj->transport;
1245                         }
1246
1247                         /* FIXME - Eventually come up with a cleaner way to
1248                          * enabling COOKIE-ECHO + DATA bundling during
1249                          * multihoming stale cookie scenarios, the following
1250                          * command plays with asoc->peer.retran_path to
1251                          * avoid the problem of sending the COOKIE-ECHO and
1252                          * DATA in different paths, which could result
1253                          * in the association being ABORTed if the DATA chunk
1254                          * is processed first by the server.  Checking the
1255                          * init error counter simply causes this command
1256                          * to be executed only during failed attempts of
1257                          * association establishment.
1258                          */
1259                         if ((asoc->peer.retran_path !=
1260                              asoc->peer.primary_path) &&
1261                             (asoc->init_err_counter > 0)) {
1262                                 sctp_add_cmd_sf(commands,
1263                                                 SCTP_CMD_FORCE_PRIM_RETRAN,
1264                                                 SCTP_NULL());
1265                         }
1266
1267                         break;
1268
1269                 case SCTP_CMD_GEN_SHUTDOWN:
1270                         /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1271                          * Reset error counts.
1272                          */
1273                         asoc->overall_error_count = 0;
1274
1275                         /* Generate a SHUTDOWN chunk.  */
1276                         new_obj = sctp_make_shutdown(asoc, chunk);
1277                         if (!new_obj)
1278                                 goto nomem;
1279                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1280                                         SCTP_CHUNK(new_obj));
1281                         break;
1282
1283                 case SCTP_CMD_CHUNK_ULP:
1284                         /* Send a chunk to the sockets layer.  */
1285                         SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1286                                           "chunk_up:", cmd->obj.ptr,
1287                                           "ulpq:", &asoc->ulpq);
1288                         sctp_ulpq_tail_data(&asoc->ulpq, cmd->obj.ptr,
1289                                             GFP_ATOMIC);
1290                         break;
1291
1292                 case SCTP_CMD_EVENT_ULP:
1293                         /* Send a notification to the sockets layer.  */
1294                         SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1295                                           "event_up:",cmd->obj.ptr,
1296                                           "ulpq:",&asoc->ulpq);
1297                         sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ptr);
1298                         break;
1299
1300                 case SCTP_CMD_REPLY:
1301                         /* If an caller has not already corked, do cork. */
1302                         if (!asoc->outqueue.cork) {
1303                                 sctp_outq_cork(&asoc->outqueue);
1304                                 local_cork = 1;
1305                         }
1306                         /* Send a chunk to our peer.  */
1307                         error = sctp_outq_tail(&asoc->outqueue, cmd->obj.ptr);
1308                         break;
1309
1310                 case SCTP_CMD_SEND_PKT:
1311                         /* Send a full packet to our peer.  */
1312                         packet = cmd->obj.ptr;
1313                         sctp_packet_transmit(packet);
1314                         sctp_ootb_pkt_free(packet);
1315                         break;
1316
1317                 case SCTP_CMD_T1_RETRAN:
1318                         /* Mark a transport for retransmission.  */
1319                         sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1320                                         SCTP_RTXR_T1_RTX);
1321                         break;
1322
1323                 case SCTP_CMD_RETRAN:
1324                         /* Mark a transport for retransmission.  */
1325                         sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1326                                         SCTP_RTXR_T3_RTX);
1327                         break;
1328
1329                 case SCTP_CMD_TRANSMIT:
1330                         /* Kick start transmission. */
1331                         error = sctp_outq_uncork(&asoc->outqueue);
1332                         local_cork = 0;
1333                         break;
1334
1335                 case SCTP_CMD_ECN_CE:
1336                         /* Do delayed CE processing.   */
1337                         sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1338                         break;
1339
1340                 case SCTP_CMD_ECN_ECNE:
1341                         /* Do delayed ECNE processing. */
1342                         new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1343                                                         chunk);
1344                         if (new_obj)
1345                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1346                                                 SCTP_CHUNK(new_obj));
1347                         break;
1348
1349                 case SCTP_CMD_ECN_CWR:
1350                         /* Do delayed CWR processing.  */
1351                         sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1352                         break;
1353
1354                 case SCTP_CMD_SETUP_T2:
1355                         sctp_cmd_setup_t2(commands, asoc, cmd->obj.ptr);
1356                         break;
1357
1358                 case SCTP_CMD_TIMER_START:
1359                         timer = &asoc->timers[cmd->obj.to];
1360                         timeout = asoc->timeouts[cmd->obj.to];
1361                         BUG_ON(!timeout);
1362
1363                         timer->expires = jiffies + timeout;
1364                         sctp_association_hold(asoc);
1365                         add_timer(timer);
1366                         break;
1367
1368                 case SCTP_CMD_TIMER_RESTART:
1369                         timer = &asoc->timers[cmd->obj.to];
1370                         timeout = asoc->timeouts[cmd->obj.to];
1371                         if (!mod_timer(timer, jiffies + timeout))
1372                                 sctp_association_hold(asoc);
1373                         break;
1374
1375                 case SCTP_CMD_TIMER_STOP:
1376                         timer = &asoc->timers[cmd->obj.to];
1377                         if (timer_pending(timer) && del_timer(timer))
1378                                 sctp_association_put(asoc);
1379                         break;
1380
1381                 case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1382                         chunk = cmd->obj.ptr;
1383                         t = sctp_assoc_choose_init_transport(asoc);
1384                         asoc->init_last_sent_to = t;
1385                         chunk->transport = t;
1386                         t->init_sent_count++;
1387                         break;
1388
1389                 case SCTP_CMD_INIT_RESTART:
1390                         /* Do the needed accounting and updates
1391                          * associated with restarting an initialization
1392                          * timer. Only multiply the timeout by two if
1393                          * all transports have been tried at the current
1394                          * timeout.
1395                          */
1396                         sctp_cmd_t1_timer_update(asoc,
1397                                                 SCTP_EVENT_TIMEOUT_T1_INIT,
1398                                                 "INIT");
1399
1400                         sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1401                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1402                         break;
1403
1404                 case SCTP_CMD_COOKIEECHO_RESTART:
1405                         /* Do the needed accounting and updates
1406                          * associated with restarting an initialization
1407                          * timer. Only multiply the timeout by two if
1408                          * all transports have been tried at the current
1409                          * timeout.
1410                          */
1411                         sctp_cmd_t1_timer_update(asoc,
1412                                                 SCTP_EVENT_TIMEOUT_T1_COOKIE,
1413                                                 "COOKIE");
1414
1415                         /* If we've sent any data bundled with
1416                          * COOKIE-ECHO we need to resend.
1417                          */
1418                         list_for_each_entry(t, &asoc->peer.transport_addr_list,
1419                                         transports) {
1420                                 sctp_retransmit_mark(&asoc->outqueue, t,
1421                                             SCTP_RTXR_T1_RTX);
1422                         }
1423
1424                         sctp_add_cmd_sf(commands,
1425                                         SCTP_CMD_TIMER_RESTART,
1426                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1427                         break;
1428
1429                 case SCTP_CMD_INIT_FAILED:
1430                         sctp_cmd_init_failed(commands, asoc, cmd->obj.err);
1431                         break;
1432
1433                 case SCTP_CMD_ASSOC_FAILED:
1434                         sctp_cmd_assoc_failed(commands, asoc, event_type,
1435                                               subtype, chunk, cmd->obj.err);
1436                         break;
1437
1438                 case SCTP_CMD_INIT_COUNTER_INC:
1439                         asoc->init_err_counter++;
1440                         break;
1441
1442                 case SCTP_CMD_INIT_COUNTER_RESET:
1443                         asoc->init_err_counter = 0;
1444                         asoc->init_cycle = 0;
1445                         list_for_each_entry(t, &asoc->peer.transport_addr_list,
1446                                             transports) {
1447                                 t->init_sent_count = 0;
1448                         }
1449                         break;
1450
1451                 case SCTP_CMD_REPORT_DUP:
1452                         sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1453                                              cmd->obj.u32);
1454                         break;
1455
1456                 case SCTP_CMD_REPORT_BAD_TAG:
1457                         SCTP_DEBUG_PRINTK("vtag mismatch!\n");
1458                         break;
1459
1460                 case SCTP_CMD_STRIKE:
1461                         /* Mark one strike against a transport.  */
1462                         sctp_do_8_2_transport_strike(asoc, cmd->obj.transport);
1463                         break;
1464
1465                 case SCTP_CMD_TRANSPORT_RESET:
1466                         t = cmd->obj.transport;
1467                         sctp_cmd_transport_reset(commands, asoc, t);
1468                         break;
1469
1470                 case SCTP_CMD_TRANSPORT_ON:
1471                         t = cmd->obj.transport;
1472                         sctp_cmd_transport_on(commands, asoc, t, chunk);
1473                         break;
1474
1475                 case SCTP_CMD_HB_TIMERS_START:
1476                         sctp_cmd_hb_timers_start(commands, asoc);
1477                         break;
1478
1479                 case SCTP_CMD_HB_TIMER_UPDATE:
1480                         t = cmd->obj.transport;
1481                         sctp_cmd_hb_timer_update(commands, t);
1482                         break;
1483
1484                 case SCTP_CMD_HB_TIMERS_STOP:
1485                         sctp_cmd_hb_timers_stop(commands, asoc);
1486                         break;
1487
1488                 case SCTP_CMD_REPORT_ERROR:
1489                         error = cmd->obj.error;
1490                         break;
1491
1492                 case SCTP_CMD_PROCESS_CTSN:
1493                         /* Dummy up a SACK for processing. */
1494                         sackh.cum_tsn_ack = cmd->obj.be32;
1495                         sackh.a_rwnd = 0;
1496                         sackh.num_gap_ack_blocks = 0;
1497                         sackh.num_dup_tsns = 0;
1498                         sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1499                                         SCTP_SACKH(&sackh));
1500                         break;
1501
1502                 case SCTP_CMD_DISCARD_PACKET:
1503                         /* We need to discard the whole packet.
1504                          * Uncork the queue since there might be
1505                          * responses pending
1506                          */
1507                         chunk->pdiscard = 1;
1508                         if (asoc) {
1509                                 sctp_outq_uncork(&asoc->outqueue);
1510                                 local_cork = 0;
1511                         }
1512                         break;
1513
1514                 case SCTP_CMD_RTO_PENDING:
1515                         t = cmd->obj.transport;
1516                         t->rto_pending = 1;
1517                         break;
1518
1519                 case SCTP_CMD_PART_DELIVER:
1520                         sctp_ulpq_partial_delivery(&asoc->ulpq, cmd->obj.ptr,
1521                                                    GFP_ATOMIC);
1522                         break;
1523
1524                 case SCTP_CMD_RENEGE:
1525                         sctp_ulpq_renege(&asoc->ulpq, cmd->obj.ptr,
1526                                          GFP_ATOMIC);
1527                         break;
1528
1529                 case SCTP_CMD_SETUP_T4:
1530                         sctp_cmd_setup_t4(commands, asoc, cmd->obj.ptr);
1531                         break;
1532
1533                 case SCTP_CMD_PROCESS_OPERR:
1534                         sctp_cmd_process_operr(commands, asoc, chunk);
1535                         break;
1536                 case SCTP_CMD_CLEAR_INIT_TAG:
1537                         asoc->peer.i.init_tag = 0;
1538                         break;
1539                 case SCTP_CMD_DEL_NON_PRIMARY:
1540                         sctp_cmd_del_non_primary(asoc);
1541                         break;
1542                 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1543                         sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1544                         break;
1545                 case SCTP_CMD_FORCE_PRIM_RETRAN:
1546                         t = asoc->peer.retran_path;
1547                         asoc->peer.retran_path = asoc->peer.primary_path;
1548                         error = sctp_outq_uncork(&asoc->outqueue);
1549                         local_cork = 0;
1550                         asoc->peer.retran_path = t;
1551                         break;
1552                 case SCTP_CMD_SET_SK_ERR:
1553                         sctp_cmd_set_sk_err(asoc, cmd->obj.error);
1554                         break;
1555                 case SCTP_CMD_ASSOC_CHANGE:
1556                         sctp_cmd_assoc_change(commands, asoc,
1557                                               cmd->obj.u8);
1558                         break;
1559                 case SCTP_CMD_ADAPTATION_IND:
1560                         sctp_cmd_adaptation_ind(commands, asoc);
1561                         break;
1562
1563                 case SCTP_CMD_ASSOC_SHKEY:
1564                         error = sctp_auth_asoc_init_active_key(asoc,
1565                                                 GFP_ATOMIC);
1566                         break;
1567                 case SCTP_CMD_UPDATE_INITTAG:
1568                         asoc->peer.i.init_tag = cmd->obj.u32;
1569                         break;
1570
1571                 default:
1572                         printk(KERN_WARNING "Impossible command: %u, %p\n",
1573                                cmd->verb, cmd->obj.ptr);
1574                         break;
1575                 }
1576
1577                 if (error)
1578                         break;
1579         }
1580
1581 out:
1582         /* If this is in response to a received chunk, wait until
1583          * we are done with the packet to open the queue so that we don't
1584          * send multiple packets in response to a single request.
1585          */
1586         if (asoc && SCTP_EVENT_T_CHUNK == event_type && chunk) {
1587                 if (chunk->end_of_packet || chunk->singleton)
1588                         sctp_outq_uncork(&asoc->outqueue);
1589         } else if (local_cork)
1590                         sctp_outq_uncork(&asoc->outqueue);
1591         return error;
1592 nomem:
1593         error = -ENOMEM;
1594         goto out;
1595 }
1596