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                                          int is_hb)
 439 {
 440         /* The check for association's overall error counter exceeding the
 441          * threshold is done in the state function.
 442          */
 443         /* We are here due to a timer expiration.  If the timer was
 444          * not a HEARTBEAT, then normal error tracking is done.
 445          * If the timer was a heartbeat, we only increment error counts
 446          * when we already have an outstanding HEARTBEAT that has not
 447          * been acknowledged.
 448          * Additionaly, some tranport states inhibit error increments.
 449          */
 450         if (!is_hb) {
 451                 asoc->overall_error_count++;
 452                 if (transport->state != SCTP_INACTIVE)
 453                         transport->error_count++;
 454          } else if (transport->hb_sent) {
 455                 if (transport->state != SCTP_UNCONFIRMED)
 456                         asoc->overall_error_count++;
 457                 if (transport->state != SCTP_INACTIVE)
 458                         transport->error_count++;
 459         }
 460
 461         if (transport->state != SCTP_INACTIVE &&
 462             (transport->error_count > transport->pathmaxrxt)) {
 463                 SCTP_DEBUG_PRINTK_IPADDR("transport_strike:association %p",
 464                                          " transport IP: port:%d failed.\n",
 465                                          asoc,
 466                                          (&transport->ipaddr),
 467                                          ntohs(transport->ipaddr.v4.sin_port));
 468                 sctp_assoc_control_transport(asoc, transport,
 469                                              SCTP_TRANSPORT_DOWN,
 470                                              SCTP_FAILED_THRESHOLD);
 471         }
 472
 473         /* E2) For the destination address for which the timer
 474          * expires, set RTO <- RTO * 2 ("back off the timer").  The
 475          * maximum value discussed in rule C7 above (RTO.max) may be
 476          * used to provide an upper bound to this doubling operation.
 477          *
 478          * Special Case:  the first HB doesn't trigger exponential backoff.
 479          * The first unacknowleged HB triggers it.  We do this with a flag
 480          * that indicates that we have an outstanding HB.
 481          */
 482         if (!is_hb || transport->hb_sent) {
 483                 transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
 484         }
 485 }
 486
 487 /* Worker routine to handle INIT command failure.  */
 488 static void sctp_cmd_init_failed(sctp_cmd_seq_t *commands,
 489                                  struct sctp_association *asoc,
 490                                  unsigned error)
 491 {
 492         struct sctp_ulpevent *event;
 493
 494         event = sctp_ulpevent_make_assoc_change(asoc,0, SCTP_CANT_STR_ASSOC,
 495                                                 (__u16)error, 0, 0, NULL,
 496                                                 GFP_ATOMIC);
 497
 498         if (event)
 499                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 500                                 SCTP_ULPEVENT(event));
 501
 502         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 503                         SCTP_STATE(SCTP_STATE_CLOSED));
 504
 505         /* SEND_FAILED sent later when cleaning up the association. */
 506         asoc->outqueue.error = error;
 507         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 508 }
 509
 510 /* Worker routine to handle SCTP_CMD_ASSOC_FAILED.  */
 511 static void sctp_cmd_assoc_failed(sctp_cmd_seq_t *commands,
 512                                   struct sctp_association *asoc,
 513                                   sctp_event_t event_type,
 514                                   sctp_subtype_t subtype,
 515                                   struct sctp_chunk *chunk,
 516                                   unsigned error)
 517 {
 518         struct sctp_ulpevent *event;
 519
 520         /* Cancel any partial delivery in progress. */
 521         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
 522
 523         if (event_type == SCTP_EVENT_T_CHUNK && subtype.chunk == SCTP_CID_ABORT)
 524                 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
 525                                                 (__u16)error, 0, 0, chunk,
 526                                                 GFP_ATOMIC);
 527         else
 528                 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
 529                                                 (__u16)error, 0, 0, NULL,
 530                                                 GFP_ATOMIC);
 531         if (event)
 532                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 533                                 SCTP_ULPEVENT(event));
 534
 535         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 536                         SCTP_STATE(SCTP_STATE_CLOSED));
 537
 538         /* SEND_FAILED sent later when cleaning up the association. */
 539         asoc->outqueue.error = error;
 540         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 541 }
 542
 543 /* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
 544  * inside the cookie.  In reality, this is only used for INIT-ACK processing
 545  * since all other cases use "temporary" associations and can do all
 546  * their work in statefuns directly.
 547  */
 548 static int sctp_cmd_process_init(sctp_cmd_seq_t *commands,
 549                                  struct sctp_association *asoc,
 550                                  struct sctp_chunk *chunk,
 551                                  sctp_init_chunk_t *peer_init,
 552                                  gfp_t gfp)
 553 {
 554         int error;
 555
 556         /* We only process the init as a sideeffect in a single
 557          * case.   This is when we process the INIT-ACK.   If we
 558          * fail during INIT processing (due to malloc problems),
 559          * just return the error and stop processing the stack.
 560          */
 561         if (!sctp_process_init(asoc, chunk->chunk_hdr->type,
 562                                sctp_source(chunk), peer_init, gfp))
 563                 error = -ENOMEM;
 564         else
 565                 error = 0;
 566
 567         return error;
 568 }
 569
 570 /* Helper function to break out starting up of heartbeat timers.  */
 571 static void sctp_cmd_hb_timers_start(sctp_cmd_seq_t *cmds,
 572                                      struct sctp_association *asoc)
 573 {
 574         struct sctp_transport *t;
 575
 576         /* Start a heartbeat timer for each transport on the association.
 577          * hold a reference on the transport to make sure none of
 578          * the needed data structures go away.
 579          */
 580         list_for_each_entry(t, &asoc->peer.transport_addr_list, transports) {
 581
 582                 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 583                         sctp_transport_hold(t);
 584         }
 585 }
 586
 587 static void sctp_cmd_hb_timers_stop(sctp_cmd_seq_t *cmds,
 588                                     struct sctp_association *asoc)
 589 {
 590         struct sctp_transport *t;
 591
 592         /* Stop all heartbeat timers. */
 593
 594         list_for_each_entry(t, &asoc->peer.transport_addr_list,
 595                         transports) {
 596                 if (del_timer(&t->hb_timer))
 597                         sctp_transport_put(t);
 598         }
 599 }
 600
 601 /* Helper function to stop any pending T3-RTX timers */
 602 static void sctp_cmd_t3_rtx_timers_stop(sctp_cmd_seq_t *cmds,
 603                                         struct sctp_association *asoc)
 604 {
 605         struct sctp_transport *t;
 606
 607         list_for_each_entry(t, &asoc->peer.transport_addr_list,
 608                         transports) {
 609                 if (timer_pending(&t->T3_rtx_timer) &&
 610                     del_timer(&t->T3_rtx_timer)) {
 611                         sctp_transport_put(t);
 612                 }
 613         }
 614 }
 615
 616
 617 /* Helper function to update the heartbeat timer. */
 618 static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
 619                                      struct sctp_transport *t)
 620 {
 621         /* Update the heartbeat timer.  */
 622         if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 623                 sctp_transport_hold(t);
 624 }
 625
 626 /* Helper function to handle the reception of an HEARTBEAT ACK.  */
 627 static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds,
 628                                   struct sctp_association *asoc,
 629                                   struct sctp_transport *t,
 630                                   struct sctp_chunk *chunk)
 631 {
 632         sctp_sender_hb_info_t *hbinfo;
 633
 634         /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
 635          * HEARTBEAT should clear the error counter of the destination
 636          * transport address to which the HEARTBEAT was sent.
 637          * The association's overall error count is also cleared.
 638          */
 639         t->error_count = 0;
 640         t->asoc->overall_error_count = 0;
 641
 642         /* Clear the hb_sent flag to signal that we had a good
 643          * acknowledgement.
 644          */
 645         t->hb_sent = 0;
 646
 647         /* Mark the destination transport address as active if it is not so
 648          * marked.
 649          */
 650         if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED))
 651                 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
 652                                              SCTP_HEARTBEAT_SUCCESS);
 653
 654         /* The receiver of the HEARTBEAT ACK should also perform an
 655          * RTT measurement for that destination transport address
 656          * using the time value carried in the HEARTBEAT ACK chunk.
 657          * If the transport's rto_pending variable has been cleared,
 658          * it was most likely due to a retransmit.  However, we want
 659          * to re-enable it to properly update the rto.
 660          */
 661         if (t->rto_pending == 0)
 662                 t->rto_pending = 1;
 663
 664         hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
 665         sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
 666
 667         /* Update the heartbeat timer.  */
 668         if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 669                 sctp_transport_hold(t);
 670 }
 671
 672
 673 /* Helper function to process the process SACK command.  */
 674 static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds,
 675                                  struct sctp_association *asoc,
 676                                  struct sctp_sackhdr *sackh)
 677 {
 678         int err = 0;
 679
 680         if (sctp_outq_sack(&asoc->outqueue, sackh)) {
 681                 /* There are no more TSNs awaiting SACK.  */
 682                 err = sctp_do_sm(SCTP_EVENT_T_OTHER,
 683                                  SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
 684                                  asoc->state, asoc->ep, asoc, NULL,
 685                                  GFP_ATOMIC);
 686         }
 687
 688         return err;
 689 }
 690
 691 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
 692  * the transport for a shutdown chunk.
 693  */
 694 static void sctp_cmd_setup_t2(sctp_cmd_seq_t *cmds,
 695                               struct sctp_association *asoc,
 696                               struct sctp_chunk *chunk)
 697 {
 698         struct sctp_transport *t;
 699
 700         t = sctp_assoc_choose_alter_transport(asoc,
 701                                               asoc->shutdown_last_sent_to);
 702         asoc->shutdown_last_sent_to = t;
 703         asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
 704         chunk->transport = t;
 705 }
 706
 707 /* Helper function to change the state of an association. */
 708 static void sctp_cmd_new_state(sctp_cmd_seq_t *cmds,
 709                                struct sctp_association *asoc,
 710                                sctp_state_t state)
 711 {
 712         struct sock *sk = asoc->base.sk;
 713
 714         asoc->state = state;
 715
 716         SCTP_DEBUG_PRINTK("sctp_cmd_new_state: asoc %p[%s]\n",
 717                           asoc, sctp_state_tbl[state]);
 718
 719         if (sctp_style(sk, TCP)) {
 720                 /* Change the sk->sk_state of a TCP-style socket that has
 721                  * sucessfully completed a connect() call.
 722                  */
 723                 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
 724                         sk->sk_state = SCTP_SS_ESTABLISHED;
 725
 726                 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
 727                 if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
 728                     sctp_sstate(sk, ESTABLISHED))
 729                         sk->sk_shutdown |= RCV_SHUTDOWN;
 730         }
 731
 732         if (sctp_state(asoc, COOKIE_WAIT)) {
 733                 /* Reset init timeouts since they may have been
 734                  * increased due to timer expirations.
 735                  */
 736                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
 737                                                 asoc->rto_initial;
 738                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
 739                                                 asoc->rto_initial;
 740         }
 741
 742         if (sctp_state(asoc, ESTABLISHED) ||
 743             sctp_state(asoc, CLOSED) ||
 744             sctp_state(asoc, SHUTDOWN_RECEIVED)) {
 745                 /* Wake up any processes waiting in the asoc's wait queue in
 746                  * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
 747                  */
 748                 if (waitqueue_active(&asoc->wait))
 749                         wake_up_interruptible(&asoc->wait);
 750
 751                 /* Wake up any processes waiting in the sk's sleep queue of
 752                  * a TCP-style or UDP-style peeled-off socket in
 753                  * sctp_wait_for_accept() or sctp_wait_for_packet().
 754                  * For a UDP-style socket, the waiters are woken up by the
 755                  * notifications.
 756                  */
 757                 if (!sctp_style(sk, UDP))
 758                         sk->sk_state_change(sk);
 759         }
 760 }
 761
 762 /* Helper function to delete an association. */
 763 static void sctp_cmd_delete_tcb(sctp_cmd_seq_t *cmds,
 764                                 struct sctp_association *asoc)
 765 {
 766         struct sock *sk = asoc->base.sk;
 767
 768         /* If it is a non-temporary association belonging to a TCP-style
 769          * listening socket that is not closed, do not free it so that accept()
 770          * can pick it up later.
 771          */
 772         if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
 773             (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
 774                 return;
 775
 776         sctp_unhash_established(asoc);
 777         sctp_association_free(asoc);
 778 }
 779
 780 /*
 781  * ADDIP Section 4.1 ASCONF Chunk Procedures
 782  * A4) Start a T-4 RTO timer, using the RTO value of the selected
 783  * destination address (we use active path instead of primary path just
 784  * because primary path may be inactive.
 785  */
 786 static void sctp_cmd_setup_t4(sctp_cmd_seq_t *cmds,
 787                                 struct sctp_association *asoc,
 788                                 struct sctp_chunk *chunk)
 789 {
 790         struct sctp_transport *t;
 791
 792         t = sctp_assoc_choose_alter_transport(asoc, chunk->transport);
 793         asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
 794         chunk->transport = t;
 795 }
 796
 797 /* Process an incoming Operation Error Chunk. */
 798 static void sctp_cmd_process_operr(sctp_cmd_seq_t *cmds,
 799                                    struct sctp_association *asoc,
 800                                    struct sctp_chunk *chunk)
 801 {
 802         struct sctp_errhdr *err_hdr;
 803         struct sctp_ulpevent *ev;
 804
 805         while (chunk->chunk_end > chunk->skb->data) {
 806                 err_hdr = (struct sctp_errhdr *)(chunk->skb->data);
 807
 808                 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
 809                                                      GFP_ATOMIC);
 810                 if (!ev)
 811                         return;
 812
 813                 sctp_ulpq_tail_event(&asoc->ulpq, ev);
 814
 815                 switch (err_hdr->cause) {
 816                 case SCTP_ERROR_UNKNOWN_CHUNK:
 817                 {
 818                         sctp_chunkhdr_t *unk_chunk_hdr;
 819
 820                         unk_chunk_hdr = (sctp_chunkhdr_t *)err_hdr->variable;
 821                         switch (unk_chunk_hdr->type) {
 822                         /* ADDIP 4.1 A9) If the peer responds to an ASCONF with
 823                          * an ERROR chunk reporting that it did not recognized
 824                          * the ASCONF chunk type, the sender of the ASCONF MUST
 825                          * NOT send any further ASCONF chunks and MUST stop its
 826                          * T-4 timer.
 827                          */
 828                         case SCTP_CID_ASCONF:
 829                                 if (asoc->peer.asconf_capable == 0)
 830                                         break;
 831
 832                                 asoc->peer.asconf_capable = 0;
 833                                 sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
 834                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
 835                                 break;
 836                         default:
 837                                 break;
 838                         }
 839                         break;
 840                 }
 841                 default:
 842                         break;
 843                 }
 844         }
 845 }
 846
 847 /* Process variable FWDTSN chunk information. */
 848 static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq,
 849                                     struct sctp_chunk *chunk)
 850 {
 851         struct sctp_fwdtsn_skip *skip;
 852         /* Walk through all the skipped SSNs */
 853         sctp_walk_fwdtsn(skip, chunk) {
 854                 sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
 855         }
 856
 857         return;
 858 }
 859
 860 /* Helper function to remove the association non-primary peer
 861  * transports.
 862  */
 863 static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
 864 {
 865         struct sctp_transport *t;
 866         struct list_head *pos;
 867         struct list_head *temp;
 868
 869         list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
 870                 t = list_entry(pos, struct sctp_transport, transports);
 871                 if (!sctp_cmp_addr_exact(&t->ipaddr,
 872                                          &asoc->peer.primary_addr)) {
 873                         sctp_assoc_del_peer(asoc, &t->ipaddr);
 874                 }
 875         }
 876
 877         return;
 878 }
 879
 880 /* Helper function to set sk_err on a 1-1 style socket. */
 881 static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
 882 {
 883         struct sock *sk = asoc->base.sk;
 884
 885         if (!sctp_style(sk, UDP))
 886                 sk->sk_err = error;
 887 }
 888
 889 /* Helper function to generate an association change event */
 890 static void sctp_cmd_assoc_change(sctp_cmd_seq_t *commands,
 891                                  struct sctp_association *asoc,
 892                                  u8 state)
 893 {
 894         struct sctp_ulpevent *ev;
 895
 896         ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0,
 897                                             asoc->c.sinit_num_ostreams,
 898                                             asoc->c.sinit_max_instreams,
 899                                             NULL, GFP_ATOMIC);
 900         if (ev)
 901                 sctp_ulpq_tail_event(&asoc->ulpq, ev);
 902 }
 903
 904 /* Helper function to generate an adaptation indication event */
 905 static void sctp_cmd_adaptation_ind(sctp_cmd_seq_t *commands,
 906                                     struct sctp_association *asoc)
 907 {
 908         struct sctp_ulpevent *ev;
 909
 910         ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
 911
 912         if (ev)
 913                 sctp_ulpq_tail_event(&asoc->ulpq, ev);
 914 }
 915
 916
 917 static void sctp_cmd_t1_timer_update(struct sctp_association *asoc,
 918                                     sctp_event_timeout_t timer,
 919                                     char *name)
 920 {
 921         struct sctp_transport *t;
 922
 923         t = asoc->init_last_sent_to;
 924         asoc->init_err_counter++;
 925
 926         if (t->init_sent_count > (asoc->init_cycle + 1)) {
 927                 asoc->timeouts[timer] *= 2;
 928                 if (asoc->timeouts[timer] > asoc->max_init_timeo) {
 929                         asoc->timeouts[timer] = asoc->max_init_timeo;
 930                 }
 931                 asoc->init_cycle++;
 932                 SCTP_DEBUG_PRINTK(
 933                         "T1 %s Timeout adjustment"
 934                         " init_err_counter: %d"
 935                         " cycle: %d"
 936                         " timeout: %ld\n",
 937                         name,
 938                         asoc->init_err_counter,
 939                         asoc->init_cycle,
 940                         asoc->timeouts[timer]);
 941         }
 942
 943 }
 944
 945 /* Send the whole message, chunk by chunk, to the outqueue.
 946  * This way the whole message is queued up and bundling if
 947  * encouraged for small fragments.
 948  */
 949 static int sctp_cmd_send_msg(struct sctp_association *asoc,
 950                                 struct sctp_datamsg *msg)
 951 {
 952         struct sctp_chunk *chunk;
 953         int error = 0;
 954
 955         list_for_each_entry(chunk, &msg->chunks, frag_list) {
 956                 error = sctp_outq_tail(&asoc->outqueue, chunk);
 957                 if (error)
 958                         break;
 959         }
 960
 961         return error;
 962 }
 963
 964
 965
 966 /* These three macros allow us to pull the debugging code out of the
 967  * main flow of sctp_do_sm() to keep attention focused on the real
 968  * functionality there.
 969  */
 970 #define DEBUG_PRE \
 971         SCTP_DEBUG_PRINTK("sctp_do_sm prefn: " \
 972                           "ep %p, %s, %s, asoc %p[%s], %s\n", \
 973                           ep, sctp_evttype_tbl[event_type], \
 974                           (*debug_fn)(subtype), asoc, \
 975                           sctp_state_tbl[state], state_fn->name)
 976
 977 #define DEBUG_POST \
 978         SCTP_DEBUG_PRINTK("sctp_do_sm postfn: " \
 979                           "asoc %p, status: %s\n", \
 980                           asoc, sctp_status_tbl[status])
 981
 982 #define DEBUG_POST_SFX \
 983         SCTP_DEBUG_PRINTK("sctp_do_sm post sfx: error %d, asoc %p[%s]\n", \
 984                           error, asoc, \
 985                           sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
 986                           sctp_assoc2id(asoc)))?asoc->state:SCTP_STATE_CLOSED])
 987
 988 /*
 989  * This is the master state machine processing function.
 990  *
 991  * If you want to understand all of lksctp, this is a
 992  * good place to start.
 993  */
 994 int sctp_do_sm(sctp_event_t event_type, sctp_subtype_t subtype,
 995                sctp_state_t state,
 996                struct sctp_endpoint *ep,
 997                struct sctp_association *asoc,
 998                void *event_arg,
 999                gfp_t gfp)
1000 {
1001         sctp_cmd_seq_t commands;
1002         const sctp_sm_table_entry_t *state_fn;
1003         sctp_disposition_t status;
1004         int error = 0;
1005         typedef const char *(printfn_t)(sctp_subtype_t);
1006
1007         static printfn_t *table[] = {
1008                 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
1009         };
1010         printfn_t *debug_fn  __attribute__ ((unused)) = table[event_type];
1011
1012         /* Look up the state function, run it, and then process the
1013          * side effects.  These three steps are the heart of lksctp.
1014          */
1015         state_fn = sctp_sm_lookup_event(event_type, state, subtype);
1016
1017         sctp_init_cmd_seq(&commands);
1018
1019         DEBUG_PRE;
1020         status = (*state_fn->fn)(ep, asoc, subtype, event_arg, &commands);
1021         DEBUG_POST;
1022
1023         error = sctp_side_effects(event_type, subtype, state,
1024                                   ep, asoc, event_arg, status,
1025                                   &commands, gfp);
1026         DEBUG_POST_SFX;
1027
1028         return error;
1029 }
1030
1031 #undef DEBUG_PRE
1032 #undef DEBUG_POST
1033
1034 /*****************************************************************
1035  * This the master state function side effect processing function.
1036  *****************************************************************/
1037 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
1038                              sctp_state_t state,
1039                              struct sctp_endpoint *ep,
1040                              struct sctp_association *asoc,
1041                              void *event_arg,
1042                              sctp_disposition_t status,
1043                              sctp_cmd_seq_t *commands,
1044                              gfp_t gfp)
1045 {
1046         int error;
1047
1048         /* FIXME - Most of the dispositions left today would be categorized
1049          * as "exceptional" dispositions.  For those dispositions, it
1050          * may not be proper to run through any of the commands at all.
1051          * For example, the command interpreter might be run only with
1052          * disposition SCTP_DISPOSITION_CONSUME.
1053          */
1054         if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
1055                                                ep, asoc,
1056                                                event_arg, status,
1057                                                commands, gfp)))
1058                 goto bail;
1059
1060         switch (status) {
1061         case SCTP_DISPOSITION_DISCARD:
1062                 SCTP_DEBUG_PRINTK("Ignored sctp protocol event - state %d, "
1063                                   "event_type %d, event_id %d\n",
1064                                   state, event_type, subtype.chunk);
1065                 break;
1066
1067         case SCTP_DISPOSITION_NOMEM:
1068                 /* We ran out of memory, so we need to discard this
1069                  * packet.
1070                  */
1071                 /* BUG--we should now recover some memory, probably by
1072                  * reneging...
1073                  */
1074                 error = -ENOMEM;
1075                 break;
1076
1077         case SCTP_DISPOSITION_DELETE_TCB:
1078                 /* This should now be a command. */
1079                 break;
1080
1081         case SCTP_DISPOSITION_CONSUME:
1082         case SCTP_DISPOSITION_ABORT:
1083                 /*
1084                  * We should no longer have much work to do here as the
1085                  * real work has been done as explicit commands above.
1086                  */
1087                 break;
1088
1089         case SCTP_DISPOSITION_VIOLATION:
1090                 if (net_ratelimit())
1091                         printk(KERN_ERR "sctp protocol violation state %d "
1092                                "chunkid %d\n", state, subtype.chunk);
1093                 break;
1094
1095         case SCTP_DISPOSITION_NOT_IMPL:
1096                 printk(KERN_WARNING "sctp unimplemented feature in state %d, "
1097                        "event_type %d, event_id %d\n",
1098                        state, event_type, subtype.chunk);
1099                 break;
1100
1101         case SCTP_DISPOSITION_BUG:
1102                 printk(KERN_ERR "sctp bug in state %d, "
1103                        "event_type %d, event_id %d\n",
1104                        state, event_type, subtype.chunk);
1105                 BUG();
1106                 break;
1107
1108         default:
1109                 printk(KERN_ERR "sctp impossible disposition %d "
1110                        "in state %d, event_type %d, event_id %d\n",
1111                        status, state, event_type, subtype.chunk);
1112                 BUG();
1113                 break;
1114         }
1115
1116 bail:
1117         return error;
1118 }
1119
1120 /********************************************************************
1121  * 2nd Level Abstractions
1122  ********************************************************************/
1123
1124 /* This is the side-effect interpreter.  */
1125 static int sctp_cmd_interpreter(sctp_event_t event_type,
1126                                 sctp_subtype_t subtype,
1127                                 sctp_state_t state,
1128                                 struct sctp_endpoint *ep,
1129                                 struct sctp_association *asoc,
1130                                 void *event_arg,
1131                                 sctp_disposition_t status,
1132                                 sctp_cmd_seq_t *commands,
1133                                 gfp_t gfp)
1134 {
1135         int error = 0;
1136         int force;
1137         sctp_cmd_t *cmd;
1138         struct sctp_chunk *new_obj;
1139         struct sctp_chunk *chunk = NULL;
1140         struct sctp_packet *packet;
1141         struct timer_list *timer;
1142         unsigned long timeout;
1143         struct sctp_transport *t;
1144         struct sctp_sackhdr sackh;
1145         int local_cork = 0;
1146
1147         if (SCTP_EVENT_T_TIMEOUT != event_type)
1148                 chunk = (struct sctp_chunk *) event_arg;
1149
1150         /* Note:  This whole file is a huge candidate for rework.
1151          * For example, each command could either have its own handler, so
1152          * the loop would look like:
1153          *     while (cmds)
1154          *         cmd->handle(x, y, z)
1155          * --jgrimm
1156          */
1157         while (NULL != (cmd = sctp_next_cmd(commands))) {
1158                 switch (cmd->verb) {
1159                 case SCTP_CMD_NOP:
1160                         /* Do nothing. */
1161                         break;
1162
1163                 case SCTP_CMD_NEW_ASOC:
1164                         /* Register a new association.  */
1165                         if (local_cork) {
1166                                 sctp_outq_uncork(&asoc->outqueue);
1167                                 local_cork = 0;
1168                         }
1169                         asoc = cmd->obj.ptr;
1170                         /* Register with the endpoint.  */
1171                         sctp_endpoint_add_asoc(ep, asoc);
1172                         sctp_hash_established(asoc);
1173                         break;
1174
1175                 case SCTP_CMD_UPDATE_ASSOC:
1176                        sctp_assoc_update(asoc, cmd->obj.ptr);
1177                        break;
1178
1179                 case SCTP_CMD_PURGE_OUTQUEUE:
1180                        sctp_outq_teardown(&asoc->outqueue);
1181                        break;
1182
1183                 case SCTP_CMD_DELETE_TCB:
1184                         if (local_cork) {
1185                                 sctp_outq_uncork(&asoc->outqueue);
1186                                 local_cork = 0;
1187                         }
1188                         /* Delete the current association.  */
1189                         sctp_cmd_delete_tcb(commands, asoc);
1190                         asoc = NULL;
1191                         break;
1192
1193                 case SCTP_CMD_NEW_STATE:
1194                         /* Enter a new state.  */
1195                         sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1196                         break;
1197
1198                 case SCTP_CMD_REPORT_TSN:
1199                         /* Record the arrival of a TSN.  */
1200                         error = sctp_tsnmap_mark(&asoc->peer.tsn_map,
1201                                                  cmd->obj.u32);
1202                         break;
1203
1204                 case SCTP_CMD_REPORT_FWDTSN:
1205                         /* Move the Cumulattive TSN Ack ahead. */
1206                         sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32);
1207
1208                         /* purge the fragmentation queue */
1209                         sctp_ulpq_reasm_flushtsn(&asoc->ulpq, cmd->obj.u32);
1210
1211                         /* Abort any in progress partial delivery. */
1212                         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
1213                         break;
1214
1215                 case SCTP_CMD_PROCESS_FWDTSN:
1216                         sctp_cmd_process_fwdtsn(&asoc->ulpq, cmd->obj.ptr);
1217                         break;
1218
1219                 case SCTP_CMD_GEN_SACK:
1220                         /* Generate a Selective ACK.
1221                          * The argument tells us whether to just count
1222                          * the packet and MAYBE generate a SACK, or
1223                          * force a SACK out.
1224                          */
1225                         force = cmd->obj.i32;
1226                         error = sctp_gen_sack(asoc, force, commands);
1227                         break;
1228
1229                 case SCTP_CMD_PROCESS_SACK:
1230                         /* Process an inbound SACK.  */
1231                         error = sctp_cmd_process_sack(commands, asoc,
1232                                                       cmd->obj.ptr);
1233                         break;
1234
1235                 case SCTP_CMD_GEN_INIT_ACK:
1236                         /* Generate an INIT ACK chunk.  */
1237                         new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1238                                                      0);
1239                         if (!new_obj)
1240                                 goto nomem;
1241
1242                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1243                                         SCTP_CHUNK(new_obj));
1244                         break;
1245
1246                 case SCTP_CMD_PEER_INIT:
1247                         /* Process a unified INIT from the peer.
1248                          * Note: Only used during INIT-ACK processing.  If
1249                          * there is an error just return to the outter
1250                          * layer which will bail.
1251                          */
1252                         error = sctp_cmd_process_init(commands, asoc, chunk,
1253                                                       cmd->obj.ptr, gfp);
1254                         break;
1255
1256                 case SCTP_CMD_GEN_COOKIE_ECHO:
1257                         /* Generate a COOKIE ECHO chunk.  */
1258                         new_obj = sctp_make_cookie_echo(asoc, chunk);
1259                         if (!new_obj) {
1260                                 if (cmd->obj.ptr)
1261                                         sctp_chunk_free(cmd->obj.ptr);
1262                                 goto nomem;
1263                         }
1264                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1265                                         SCTP_CHUNK(new_obj));
1266
1267                         /* If there is an ERROR chunk to be sent along with
1268                          * the COOKIE_ECHO, send it, too.
1269                          */
1270                         if (cmd->obj.ptr)
1271                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1272                                                 SCTP_CHUNK(cmd->obj.ptr));
1273
1274                         if (new_obj->transport) {
1275                                 new_obj->transport->init_sent_count++;
1276                                 asoc->init_last_sent_to = new_obj->transport;
1277                         }
1278
1279                         /* FIXME - Eventually come up with a cleaner way to
1280                          * enabling COOKIE-ECHO + DATA bundling during
1281                          * multihoming stale cookie scenarios, the following
1282                          * command plays with asoc->peer.retran_path to
1283                          * avoid the problem of sending the COOKIE-ECHO and
1284                          * DATA in different paths, which could result
1285                          * in the association being ABORTed if the DATA chunk
1286                          * is processed first by the server.  Checking the
1287                          * init error counter simply causes this command
1288                          * to be executed only during failed attempts of
1289                          * association establishment.
1290                          */
1291                         if ((asoc->peer.retran_path !=
1292                              asoc->peer.primary_path) &&
1293                             (asoc->init_err_counter > 0)) {
1294                                 sctp_add_cmd_sf(commands,
1295                                                 SCTP_CMD_FORCE_PRIM_RETRAN,
1296                                                 SCTP_NULL());
1297                         }
1298
1299                         break;
1300
1301                 case SCTP_CMD_GEN_SHUTDOWN:
1302                         /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1303                          * Reset error counts.
1304                          */
1305                         asoc->overall_error_count = 0;
1306
1307                         /* Generate a SHUTDOWN chunk.  */
1308                         new_obj = sctp_make_shutdown(asoc, chunk);
1309                         if (!new_obj)
1310                                 goto nomem;
1311                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1312                                         SCTP_CHUNK(new_obj));
1313                         break;
1314
1315                 case SCTP_CMD_CHUNK_ULP:
1316                         /* Send a chunk to the sockets layer.  */
1317                         SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1318                                           "chunk_up:", cmd->obj.ptr,
1319                                           "ulpq:", &asoc->ulpq);
1320                         sctp_ulpq_tail_data(&asoc->ulpq, cmd->obj.ptr,
1321                                             GFP_ATOMIC);
1322                         break;
1323
1324                 case SCTP_CMD_EVENT_ULP:
1325                         /* Send a notification to the sockets layer.  */
1326                         SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1327                                           "event_up:",cmd->obj.ptr,
1328                                           "ulpq:",&asoc->ulpq);
1329                         sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ptr);
1330                         break;
1331
1332                 case SCTP_CMD_REPLY:
1333                         /* If an caller has not already corked, do cork. */
1334                         if (!asoc->outqueue.cork) {
1335                                 sctp_outq_cork(&asoc->outqueue);
1336                                 local_cork = 1;
1337                         }
1338                         /* Send a chunk to our peer.  */
1339                         error = sctp_outq_tail(&asoc->outqueue, cmd->obj.ptr);
1340                         break;
1341
1342                 case SCTP_CMD_SEND_PKT:
1343                         /* Send a full packet to our peer.  */
1344                         packet = cmd->obj.ptr;
1345                         sctp_packet_transmit(packet);
1346                         sctp_ootb_pkt_free(packet);
1347                         break;
1348
1349                 case SCTP_CMD_T1_RETRAN:
1350                         /* Mark a transport for retransmission.  */
1351                         sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1352                                         SCTP_RTXR_T1_RTX);
1353                         break;
1354
1355                 case SCTP_CMD_RETRAN:
1356                         /* Mark a transport for retransmission.  */
1357                         sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1358                                         SCTP_RTXR_T3_RTX);
1359                         break;
1360
1361                 case SCTP_CMD_TRANSMIT:
1362                         /* Kick start transmission. */
1363                         error = sctp_outq_uncork(&asoc->outqueue);
1364                         local_cork = 0;
1365                         break;
1366
1367                 case SCTP_CMD_ECN_CE:
1368                         /* Do delayed CE processing.   */
1369                         sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1370                         break;
1371
1372                 case SCTP_CMD_ECN_ECNE:
1373                         /* Do delayed ECNE processing. */
1374                         new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1375                                                         chunk);
1376                         if (new_obj)
1377                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1378                                                 SCTP_CHUNK(new_obj));
1379                         break;
1380
1381                 case SCTP_CMD_ECN_CWR:
1382                         /* Do delayed CWR processing.  */
1383                         sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1384                         break;
1385
1386                 case SCTP_CMD_SETUP_T2:
1387                         sctp_cmd_setup_t2(commands, asoc, cmd->obj.ptr);
1388                         break;
1389
1390                 case SCTP_CMD_TIMER_START:
1391                         timer = &asoc->timers[cmd->obj.to];
1392                         timeout = asoc->timeouts[cmd->obj.to];
1393                         BUG_ON(!timeout);
1394
1395                         timer->expires = jiffies + timeout;
1396                         sctp_association_hold(asoc);
1397                         add_timer(timer);
1398                         break;
1399
1400                 case SCTP_CMD_TIMER_RESTART:
1401                         timer = &asoc->timers[cmd->obj.to];
1402                         timeout = asoc->timeouts[cmd->obj.to];
1403                         if (!mod_timer(timer, jiffies + timeout))
1404                                 sctp_association_hold(asoc);
1405                         break;
1406
1407                 case SCTP_CMD_TIMER_STOP:
1408                         timer = &asoc->timers[cmd->obj.to];
1409                         if (timer_pending(timer) && del_timer(timer))
1410                                 sctp_association_put(asoc);
1411                         break;
1412
1413                 case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1414                         chunk = cmd->obj.ptr;
1415                         t = sctp_assoc_choose_alter_transport(asoc,
1416                                                 asoc->init_last_sent_to);
1417                         asoc->init_last_sent_to = t;
1418                         chunk->transport = t;
1419                         t->init_sent_count++;
1420                         break;
1421
1422                 case SCTP_CMD_INIT_RESTART:
1423                         /* Do the needed accounting and updates
1424                          * associated with restarting an initialization
1425                          * timer. Only multiply the timeout by two if
1426                          * all transports have been tried at the current
1427                          * timeout.
1428                          */
1429                         sctp_cmd_t1_timer_update(asoc,
1430                                                 SCTP_EVENT_TIMEOUT_T1_INIT,
1431                                                 "INIT");
1432
1433                         sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1434                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1435                         break;
1436
1437                 case SCTP_CMD_COOKIEECHO_RESTART:
1438                         /* Do the needed accounting and updates
1439                          * associated with restarting an initialization
1440                          * timer. Only multiply the timeout by two if
1441                          * all transports have been tried at the current
1442                          * timeout.
1443                          */
1444                         sctp_cmd_t1_timer_update(asoc,
1445                                                 SCTP_EVENT_TIMEOUT_T1_COOKIE,
1446                                                 "COOKIE");
1447
1448                         /* If we've sent any data bundled with
1449                          * COOKIE-ECHO we need to resend.
1450                          */
1451                         list_for_each_entry(t, &asoc->peer.transport_addr_list,
1452                                         transports) {
1453                                 sctp_retransmit_mark(&asoc->outqueue, t,
1454                                             SCTP_RTXR_T1_RTX);
1455                         }
1456
1457                         sctp_add_cmd_sf(commands,
1458                                         SCTP_CMD_TIMER_RESTART,
1459                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1460                         break;
1461
1462                 case SCTP_CMD_INIT_FAILED:
1463                         sctp_cmd_init_failed(commands, asoc, cmd->obj.err);
1464                         break;
1465
1466                 case SCTP_CMD_ASSOC_FAILED:
1467                         sctp_cmd_assoc_failed(commands, asoc, event_type,
1468                                               subtype, chunk, cmd->obj.err);
1469                         break;
1470
1471                 case SCTP_CMD_INIT_COUNTER_INC:
1472                         asoc->init_err_counter++;
1473                         break;
1474
1475                 case SCTP_CMD_INIT_COUNTER_RESET:
1476                         asoc->init_err_counter = 0;
1477                         asoc->init_cycle = 0;
1478                         list_for_each_entry(t, &asoc->peer.transport_addr_list,
1479                                             transports) {
1480                                 t->init_sent_count = 0;
1481                         }
1482                         break;
1483
1484                 case SCTP_CMD_REPORT_DUP:
1485                         sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1486                                              cmd->obj.u32);
1487                         break;
1488
1489                 case SCTP_CMD_REPORT_BAD_TAG:
1490                         SCTP_DEBUG_PRINTK("vtag mismatch!\n");
1491                         break;
1492
1493                 case SCTP_CMD_STRIKE:
1494                         /* Mark one strike against a transport.  */
1495                         sctp_do_8_2_transport_strike(asoc, cmd->obj.transport,
1496                                                     0);
1497                         break;
1498
1499                 case SCTP_CMD_TRANSPORT_IDLE:
1500                         t = cmd->obj.transport;
1501                         sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
1502                         break;
1503
1504                 case SCTP_CMD_TRANSPORT_HB_SENT:
1505                         t = cmd->obj.transport;
1506                         sctp_do_8_2_transport_strike(asoc, t, 1);
1507                         t->hb_sent = 1;
1508                         break;
1509
1510                 case SCTP_CMD_TRANSPORT_ON:
1511                         t = cmd->obj.transport;
1512                         sctp_cmd_transport_on(commands, asoc, t, chunk);
1513                         break;
1514
1515                 case SCTP_CMD_HB_TIMERS_START:
1516                         sctp_cmd_hb_timers_start(commands, asoc);
1517                         break;
1518
1519                 case SCTP_CMD_HB_TIMER_UPDATE:
1520                         t = cmd->obj.transport;
1521                         sctp_cmd_hb_timer_update(commands, t);
1522                         break;
1523
1524                 case SCTP_CMD_HB_TIMERS_STOP:
1525                         sctp_cmd_hb_timers_stop(commands, asoc);
1526                         break;
1527
1528                 case SCTP_CMD_REPORT_ERROR:
1529                         error = cmd->obj.error;
1530                         break;
1531
1532                 case SCTP_CMD_PROCESS_CTSN:
1533                         /* Dummy up a SACK for processing. */
1534                         sackh.cum_tsn_ack = cmd->obj.be32;
1535                         sackh.a_rwnd = asoc->peer.rwnd +
1536                                         asoc->outqueue.outstanding_bytes;
1537                         sackh.num_gap_ack_blocks = 0;
1538                         sackh.num_dup_tsns = 0;
1539                         sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1540                                         SCTP_SACKH(&sackh));
1541                         break;
1542
1543                 case SCTP_CMD_DISCARD_PACKET:
1544                         /* We need to discard the whole packet.
1545                          * Uncork the queue since there might be
1546                          * responses pending
1547                          */
1548                         chunk->pdiscard = 1;
1549                         if (asoc) {
1550                                 sctp_outq_uncork(&asoc->outqueue);
1551                                 local_cork = 0;
1552                         }
1553                         break;
1554
1555                 case SCTP_CMD_RTO_PENDING:
1556                         t = cmd->obj.transport;
1557                         t->rto_pending = 1;
1558                         break;
1559
1560                 case SCTP_CMD_PART_DELIVER:
1561                         sctp_ulpq_partial_delivery(&asoc->ulpq, cmd->obj.ptr,
1562                                                    GFP_ATOMIC);
1563                         break;
1564
1565                 case SCTP_CMD_RENEGE:
1566                         sctp_ulpq_renege(&asoc->ulpq, cmd->obj.ptr,
1567                                          GFP_ATOMIC);
1568                         break;
1569
1570                 case SCTP_CMD_SETUP_T4:
1571                         sctp_cmd_setup_t4(commands, asoc, cmd->obj.ptr);
1572                         break;
1573
1574                 case SCTP_CMD_PROCESS_OPERR:
1575                         sctp_cmd_process_operr(commands, asoc, chunk);
1576                         break;
1577                 case SCTP_CMD_CLEAR_INIT_TAG:
1578                         asoc->peer.i.init_tag = 0;
1579                         break;
1580                 case SCTP_CMD_DEL_NON_PRIMARY:
1581                         sctp_cmd_del_non_primary(asoc);
1582                         break;
1583                 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1584                         sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1585                         break;
1586                 case SCTP_CMD_FORCE_PRIM_RETRAN:
1587                         t = asoc->peer.retran_path;
1588                         asoc->peer.retran_path = asoc->peer.primary_path;
1589                         error = sctp_outq_uncork(&asoc->outqueue);
1590                         local_cork = 0;
1591                         asoc->peer.retran_path = t;
1592                         break;
1593                 case SCTP_CMD_SET_SK_ERR:
1594                         sctp_cmd_set_sk_err(asoc, cmd->obj.error);
1595                         break;
1596                 case SCTP_CMD_ASSOC_CHANGE:
1597                         sctp_cmd_assoc_change(commands, asoc,
1598                                               cmd->obj.u8);
1599                         break;
1600                 case SCTP_CMD_ADAPTATION_IND:
1601                         sctp_cmd_adaptation_ind(commands, asoc);
1602                         break;
1603
1604                 case SCTP_CMD_ASSOC_SHKEY:
1605                         error = sctp_auth_asoc_init_active_key(asoc,
1606                                                 GFP_ATOMIC);
1607                         break;
1608                 case SCTP_CMD_UPDATE_INITTAG:
1609                         asoc->peer.i.init_tag = cmd->obj.u32;
1610                         break;
1611                 case SCTP_CMD_SEND_MSG:
1612                         if (!asoc->outqueue.cork) {
1613                                 sctp_outq_cork(&asoc->outqueue);
1614                                 local_cork = 1;
1615                         }
1616                         error = sctp_cmd_send_msg(asoc, cmd->obj.msg);
1617                         break;
1618                 default:
1619                         printk(KERN_WARNING "Impossible command: %u, %p\n",
1620                                cmd->verb, cmd->obj.ptr);
1621                         break;
1622                 }
1623
1624                 if (error)
1625                         break;
1626         }
1627
1628 out:
1629         /* If this is in response to a received chunk, wait until
1630          * we are done with the packet to open the queue so that we don't
1631          * send multiple packets in response to a single request.
1632          */
1633         if (asoc && SCTP_EVENT_T_CHUNK == event_type && chunk) {
1634                 if (chunk->end_of_packet || chunk->singleton)
1635                         error = sctp_outq_uncork(&asoc->outqueue);
1636         } else if (local_cork)
1637                 error = sctp_outq_uncork(&asoc->outqueue);
1638         return error;
1639 nomem:
1640         error = -ENOMEM;
1641         goto out;
1642 }
1643