net/sctp/sm_sideeffect.c

   1 /* SCTP kernel reference 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 reference 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  * The SCTP reference 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  * The SCTP reference implementation is distributed in the hope that it
  19  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
  20  *                 ************************
  21  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  22  * See the GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with GNU CC; see the file COPYING.  If not, write to
  26  * the Free Software Foundation, 59 Temple Place - Suite 330,
  27  * Boston, MA 02111-1307, USA.
  28  *
  29  * Please send any bug reports or fixes you make to the
  30  * email address(es):
  31  *    lksctp developers <lksctp-developers@lists.sourceforge.net>
  32  *
  33  * Or submit a bug report through the following website:
  34  *    http://www.sf.net/projects/lksctp
  35  *
  36  * Written or modified by:
  37  *    La Monte H.P. Yarroll <piggy@acm.org>
  38  *    Karl Knutson          <karl@athena.chicago.il.us>
  39  *    Jon Grimm             <jgrimm@austin.ibm.com>
  40  *    Hui Huang             <hui.huang@nokia.com>
  41  *    Dajiang Zhang         <dajiang.zhang@nokia.com>
  42  *    Daisy Chang           <daisyc@us.ibm.com>
  43  *    Sridhar Samudrala     <sri@us.ibm.com>
  44  *    Ardelle Fan           <ardelle.fan@intel.com>
  45  *
  46  * Any bugs reported given to us we will try to fix... any fixes shared will
  47  * be incorporated into the next SCTP release.
  48  */
  49
  50 #include <linux/skbuff.h>
  51 #include <linux/types.h>
  52 #include <linux/socket.h>
  53 #include <linux/ip.h>
  54 #include <net/sock.h>
  55 #include <net/sctp/sctp.h>
  56 #include <net/sctp/sm.h>
  57
  58 static int sctp_cmd_interpreter(sctp_event_t event_type,
  59                                 sctp_subtype_t subtype,
  60                                 sctp_state_t state,
  61                                 struct sctp_endpoint *ep,
  62                                 struct sctp_association *asoc,
  63                                 void *event_arg,
  64                                 sctp_disposition_t status,
  65                                 sctp_cmd_seq_t *commands,
  66                                 gfp_t gfp);
  67 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
  68                              sctp_state_t state,
  69                              struct sctp_endpoint *ep,
  70                              struct sctp_association *asoc,
  71                              void *event_arg,
  72                              sctp_disposition_t status,
  73                              sctp_cmd_seq_t *commands,
  74                              gfp_t gfp);
  75
  76 /********************************************************************
  77  * Helper functions
  78  ********************************************************************/
  79
  80 /* A helper function for delayed processing of INET ECN CE bit. */
  81 static void sctp_do_ecn_ce_work(struct sctp_association *asoc,
  82                                 __u32 lowest_tsn)
  83 {
  84         /* Save the TSN away for comparison when we receive CWR */
  85
  86         asoc->last_ecne_tsn = lowest_tsn;
  87         asoc->need_ecne = 1;
  88 }
  89
  90 /* Helper function for delayed processing of SCTP ECNE chunk.  */
  91 /* RFC 2960 Appendix A
  92  *
  93  * RFC 2481 details a specific bit for a sender to send in
  94  * the header of its next outbound TCP segment to indicate to
  95  * its peer that it has reduced its congestion window.  This
  96  * is termed the CWR bit.  For SCTP the same indication is made
  97  * by including the CWR chunk.  This chunk contains one data
  98  * element, i.e. the TSN number that was sent in the ECNE chunk.
  99  * This element represents the lowest TSN number in the datagram
 100  * that was originally marked with the CE bit.
 101  */
 102 static struct sctp_chunk *sctp_do_ecn_ecne_work(struct sctp_association *asoc,
 103                                            __u32 lowest_tsn,
 104                                            struct sctp_chunk *chunk)
 105 {
 106         struct sctp_chunk *repl;
 107
 108         /* Our previously transmitted packet ran into some congestion
 109          * so we should take action by reducing cwnd and ssthresh
 110          * and then ACK our peer that we we've done so by
 111          * sending a CWR.
 112          */
 113
 114         /* First, try to determine if we want to actually lower
 115          * our cwnd variables.  Only lower them if the ECNE looks more
 116          * recent than the last response.
 117          */
 118         if (TSN_lt(asoc->last_cwr_tsn, lowest_tsn)) {
 119                 struct sctp_transport *transport;
 120
 121                 /* Find which transport's congestion variables
 122                  * need to be adjusted.
 123                  */
 124                 transport = sctp_assoc_lookup_tsn(asoc, lowest_tsn);
 125
 126                 /* Update the congestion variables. */
 127                 if (transport)
 128                         sctp_transport_lower_cwnd(transport,
 129                                                   SCTP_LOWER_CWND_ECNE);
 130                 asoc->last_cwr_tsn = lowest_tsn;
 131         }
 132
 133         /* Always try to quiet the other end.  In case of lost CWR,
 134          * resend last_cwr_tsn.
 135          */
 136         repl = sctp_make_cwr(asoc, asoc->last_cwr_tsn, chunk);
 137
 138         /* If we run out of memory, it will look like a lost CWR.  We'll
 139          * get back in sync eventually.
 140          */
 141         return repl;
 142 }
 143
 144 /* Helper function to do delayed processing of ECN CWR chunk.  */
 145 static void sctp_do_ecn_cwr_work(struct sctp_association *asoc,
 146                                  __u32 lowest_tsn)
 147 {
 148         /* Turn off ECNE getting auto-prepended to every outgoing
 149          * packet
 150          */
 151         asoc->need_ecne = 0;
 152 }
 153
 154 /* Generate SACK if necessary.  We call this at the end of a packet.  */
 155 static int sctp_gen_sack(struct sctp_association *asoc, int force,
 156                          sctp_cmd_seq_t *commands)
 157 {
 158         __u32 ctsn, max_tsn_seen;
 159         struct sctp_chunk *sack;
 160         struct sctp_transport *trans = asoc->peer.last_data_from;
 161         int error = 0;
 162
 163         if (force ||
 164             (!trans && (asoc->param_flags & SPP_SACKDELAY_DISABLE)) ||
 165             (trans && (trans->param_flags & SPP_SACKDELAY_DISABLE)))
 166                 asoc->peer.sack_needed = 1;
 167
 168         ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
 169         max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
 170
 171         /* From 12.2 Parameters necessary per association (i.e. the TCB):
 172          *
 173          * Ack State : This flag indicates if the next received packet
 174          *           : is to be responded to with a SACK. ...
 175          *           : When DATA chunks are out of order, SACK's
 176          *           : are not delayed (see Section 6).
 177          *
 178          * [This is actually not mentioned in Section 6, but we
 179          * implement it here anyway. --piggy]
 180          */
 181         if (max_tsn_seen != ctsn)
 182                 asoc->peer.sack_needed = 1;
 183
 184         /* From 6.2  Acknowledgement on Reception of DATA Chunks:
 185          *
 186          * Section 4.2 of [RFC2581] SHOULD be followed. Specifically,
 187          * an acknowledgement SHOULD be generated for at least every
 188          * second packet (not every second DATA chunk) received, and
 189          * SHOULD be generated within 200 ms of the arrival of any
 190          * unacknowledged DATA chunk. ...
 191          */
 192         if (!asoc->peer.sack_needed) {
 193                 /* We will need a SACK for the next packet.  */
 194                 asoc->peer.sack_needed = 1;
 195
 196                 /* Set the SACK delay timeout based on the
 197                  * SACK delay for the last transport
 198                  * data was received from, or the default
 199                  * for the association.
 200                  */
 201                 if (trans)
 202                         asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
 203                                 trans->sackdelay;
 204                 else
 205                         asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
 206                                 asoc->sackdelay;
 207
 208                 /* Restart the SACK timer. */
 209                 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
 210                                 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
 211         } else {
 212                 if (asoc->a_rwnd > asoc->rwnd)
 213                         asoc->a_rwnd = asoc->rwnd;
 214                 sack = sctp_make_sack(asoc);
 215                 if (!sack)
 216                         goto nomem;
 217
 218                 asoc->peer.sack_needed = 0;
 219
 220                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(sack));
 221
 222                 /* Stop the SACK timer.  */
 223                 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
 224                                 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
 225         }
 226
 227         return error;
 228 nomem:
 229         error = -ENOMEM;
 230         return error;
 231 }
 232
 233 /* When the T3-RTX timer expires, it calls this function to create the
 234  * relevant state machine event.
 235  */
 236 void sctp_generate_t3_rtx_event(unsigned long peer)
 237 {
 238         int error;
 239         struct sctp_transport *transport = (struct sctp_transport *) peer;
 240         struct sctp_association *asoc = transport->asoc;
 241
 242         /* Check whether a task is in the sock.  */
 243
 244         sctp_bh_lock_sock(asoc->base.sk);
 245         if (sock_owned_by_user(asoc->base.sk)) {
 246                 SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __FUNCTION__);
 247
 248                 /* Try again later.  */
 249                 if (!mod_timer(&transport->T3_rtx_timer, jiffies + (HZ/20)))
 250                         sctp_transport_hold(transport);
 251                 goto out_unlock;
 252         }
 253
 254         /* Is this transport really dead and just waiting around for
 255          * the timer to let go of the reference?
 256          */
 257         if (transport->dead)
 258                 goto out_unlock;
 259
 260         /* Run through the state machine.  */
 261         error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
 262                            SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX),
 263                            asoc->state,
 264                            asoc->ep, asoc,
 265                            transport, GFP_ATOMIC);
 266
 267         if (error)
 268                 asoc->base.sk->sk_err = -error;
 269
 270 out_unlock:
 271         sctp_bh_unlock_sock(asoc->base.sk);
 272         sctp_transport_put(transport);
 273 }
 274
 275 /* This is a sa interface for producing timeout events.  It works
 276  * for timeouts which use the association as their parameter.
 277  */
 278 static void sctp_generate_timeout_event(struct sctp_association *asoc,
 279                                         sctp_event_timeout_t timeout_type)
 280 {
 281         int error = 0;
 282
 283         sctp_bh_lock_sock(asoc->base.sk);
 284         if (sock_owned_by_user(asoc->base.sk)) {
 285                 SCTP_DEBUG_PRINTK("%s:Sock is busy: timer %d\n",
 286                                   __FUNCTION__,
 287                                   timeout_type);
 288
 289                 /* Try again later.  */
 290                 if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20)))
 291                         sctp_association_hold(asoc);
 292                 goto out_unlock;
 293         }
 294
 295         /* Is this association really dead and just waiting around for
 296          * the timer to let go of the reference?
 297          */
 298         if (asoc->base.dead)
 299                 goto out_unlock;
 300
 301         /* Run through the state machine.  */
 302         error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
 303                            SCTP_ST_TIMEOUT(timeout_type),
 304                            asoc->state, asoc->ep, asoc,
 305                            (void *)timeout_type, GFP_ATOMIC);
 306
 307         if (error)
 308                 asoc->base.sk->sk_err = -error;
 309
 310 out_unlock:
 311         sctp_bh_unlock_sock(asoc->base.sk);
 312         sctp_association_put(asoc);
 313 }
 314
 315 static void sctp_generate_t1_cookie_event(unsigned long data)
 316 {
 317         struct sctp_association *asoc = (struct sctp_association *) data;
 318         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
 319 }
 320
 321 static void sctp_generate_t1_init_event(unsigned long data)
 322 {
 323         struct sctp_association *asoc = (struct sctp_association *) data;
 324         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
 325 }
 326
 327 static void sctp_generate_t2_shutdown_event(unsigned long data)
 328 {
 329         struct sctp_association *asoc = (struct sctp_association *) data;
 330         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
 331 }
 332
 333 static void sctp_generate_t4_rto_event(unsigned long data)
 334 {
 335         struct sctp_association *asoc = (struct sctp_association *) data;
 336         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
 337 }
 338
 339 static void sctp_generate_t5_shutdown_guard_event(unsigned long data)
 340 {
 341         struct sctp_association *asoc = (struct sctp_association *)data;
 342         sctp_generate_timeout_event(asoc,
 343                                     SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);
 344
 345 } /* sctp_generate_t5_shutdown_guard_event() */
 346
 347 static void sctp_generate_autoclose_event(unsigned long data)
 348 {
 349         struct sctp_association *asoc = (struct sctp_association *) data;
 350         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE);
 351 }
 352
 353 /* Generate a heart beat event.  If the sock is busy, reschedule.   Make
 354  * sure that the transport is still valid.
 355  */
 356 void sctp_generate_heartbeat_event(unsigned long data)
 357 {
 358         int error = 0;
 359         struct sctp_transport *transport = (struct sctp_transport *) data;
 360         struct sctp_association *asoc = transport->asoc;
 361
 362         sctp_bh_lock_sock(asoc->base.sk);
 363         if (sock_owned_by_user(asoc->base.sk)) {
 364                 SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __FUNCTION__);
 365
 366                 /* Try again later.  */
 367                 if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20)))
 368                         sctp_transport_hold(transport);
 369                 goto out_unlock;
 370         }
 371
 372         /* Is this structure just waiting around for us to actually
 373          * get destroyed?
 374          */
 375         if (transport->dead)
 376                 goto out_unlock;
 377
 378         error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
 379                            SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
 380                            asoc->state, asoc->ep, asoc,
 381                            transport, GFP_ATOMIC);
 382
 383          if (error)
 384                  asoc->base.sk->sk_err = -error;
 385
 386 out_unlock:
 387         sctp_bh_unlock_sock(asoc->base.sk);
 388         sctp_transport_put(transport);
 389 }
 390
 391 /* Inject a SACK Timeout event into the state machine.  */
 392 static void sctp_generate_sack_event(unsigned long data)
 393 {
 394         struct sctp_association *asoc = (struct sctp_association *) data;
 395         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
 396 }
 397
 398 sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
 399         NULL,
 400         sctp_generate_t1_cookie_event,
 401         sctp_generate_t1_init_event,
 402         sctp_generate_t2_shutdown_event,
 403         NULL,
 404         sctp_generate_t4_rto_event,
 405         sctp_generate_t5_shutdown_guard_event,
 406         NULL,
 407         sctp_generate_sack_event,
 408         sctp_generate_autoclose_event,
 409 };
 410
 411
 412 /* RFC 2960 8.2 Path Failure Detection
 413  *
 414  * When its peer endpoint is multi-homed, an endpoint should keep a
 415  * error counter for each of the destination transport addresses of the
 416  * peer endpoint.
 417  *
 418  * Each time the T3-rtx timer expires on any address, or when a
 419  * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
 420  * the error counter of that destination address will be incremented.
 421  * When the value in the error counter exceeds the protocol parameter
 422  * 'Path.Max.Retrans' of that destination address, the endpoint should
 423  * mark the destination transport address as inactive, and a
 424  * notification SHOULD be sent to the upper layer.
 425  *
 426  */
 427 static void sctp_do_8_2_transport_strike(struct sctp_association *asoc,
 428                                          struct sctp_transport *transport)
 429 {
 430         /* The check for association's overall error counter exceeding the
 431          * threshold is done in the state function.
 432          */
 433         /* When probing UNCONFIRMED addresses, the association overall
 434          * error count is NOT incremented
 435          */
 436         if (transport->state != SCTP_UNCONFIRMED)
 437                 asoc->overall_error_count++;
 438
 439         if (transport->state != SCTP_INACTIVE &&
 440             (transport->error_count++ >= transport->pathmaxrxt)) {
 441                 SCTP_DEBUG_PRINTK_IPADDR("transport_strike:association %p",
 442                                          " transport IP: port:%d failed.\n",
 443                                          asoc,
 444                                          (&transport->ipaddr),
 445                                          ntohs(transport->ipaddr.v4.sin_port));
 446                 sctp_assoc_control_transport(asoc, transport,
 447                                              SCTP_TRANSPORT_DOWN,
 448                                              SCTP_FAILED_THRESHOLD);
 449         }
 450
 451         /* E2) For the destination address for which the timer
 452          * expires, set RTO <- RTO * 2 ("back off the timer").  The
 453          * maximum value discussed in rule C7 above (RTO.max) may be
 454          * used to provide an upper bound to this doubling operation.
 455          */
 456         transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
 457 }
 458
 459 /* Worker routine to handle INIT command failure.  */
 460 static void sctp_cmd_init_failed(sctp_cmd_seq_t *commands,
 461                                  struct sctp_association *asoc,
 462                                  unsigned error)
 463 {
 464         struct sctp_ulpevent *event;
 465
 466         event = sctp_ulpevent_make_assoc_change(asoc,0, SCTP_CANT_STR_ASSOC,
 467                                                 (__u16)error, 0, 0,
 468                                                 GFP_ATOMIC);
 469
 470         if (event)
 471                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 472                                 SCTP_ULPEVENT(event));
 473
 474         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 475                         SCTP_STATE(SCTP_STATE_CLOSED));
 476
 477         /* SEND_FAILED sent later when cleaning up the association. */
 478         asoc->outqueue.error = error;
 479         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 480 }
 481
 482 /* Worker routine to handle SCTP_CMD_ASSOC_FAILED.  */
 483 static void sctp_cmd_assoc_failed(sctp_cmd_seq_t *commands,
 484                                   struct sctp_association *asoc,
 485                                   sctp_event_t event_type,
 486                                   sctp_subtype_t subtype,
 487                                   struct sctp_chunk *chunk,
 488                                   unsigned error)
 489 {
 490         struct sctp_ulpevent *event;
 491
 492         /* Cancel any partial delivery in progress. */
 493         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
 494
 495         event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
 496                                                 (__u16)error, 0, 0,
 497                                                 GFP_ATOMIC);
 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 /* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
 511  * inside the cookie.  In reality, this is only used for INIT-ACK processing
 512  * since all other cases use "temporary" associations and can do all
 513  * their work in statefuns directly.
 514  */
 515 static int sctp_cmd_process_init(sctp_cmd_seq_t *commands,
 516                                  struct sctp_association *asoc,
 517                                  struct sctp_chunk *chunk,
 518                                  sctp_init_chunk_t *peer_init,
 519                                  gfp_t gfp)
 520 {
 521         int error;
 522
 523         /* We only process the init as a sideeffect in a single
 524          * case.   This is when we process the INIT-ACK.   If we
 525          * fail during INIT processing (due to malloc problems),
 526          * just return the error and stop processing the stack.
 527          */
 528         if (!sctp_process_init(asoc, chunk->chunk_hdr->type,
 529                                sctp_source(chunk), peer_init, gfp))
 530                 error = -ENOMEM;
 531         else
 532                 error = 0;
 533
 534         return error;
 535 }
 536
 537 /* Helper function to break out starting up of heartbeat timers.  */
 538 static void sctp_cmd_hb_timers_start(sctp_cmd_seq_t *cmds,
 539                                      struct sctp_association *asoc)
 540 {
 541         struct sctp_transport *t;
 542         struct list_head *pos;
 543
 544         /* Start a heartbeat timer for each transport on the association.
 545          * hold a reference on the transport to make sure none of
 546          * the needed data structures go away.
 547          */
 548         list_for_each(pos, &asoc->peer.transport_addr_list) {
 549                 t = list_entry(pos, struct sctp_transport, transports);
 550
 551                 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 552                         sctp_transport_hold(t);
 553         }
 554 }
 555
 556 static void sctp_cmd_hb_timers_stop(sctp_cmd_seq_t *cmds,
 557                                     struct sctp_association *asoc)
 558 {
 559         struct sctp_transport *t;
 560         struct list_head *pos;
 561
 562         /* Stop all heartbeat timers. */
 563
 564         list_for_each(pos, &asoc->peer.transport_addr_list) {
 565                 t = list_entry(pos, struct sctp_transport, transports);
 566                 if (del_timer(&t->hb_timer))
 567                         sctp_transport_put(t);
 568         }
 569 }
 570
 571 /* Helper function to stop any pending T3-RTX timers */
 572 static void sctp_cmd_t3_rtx_timers_stop(sctp_cmd_seq_t *cmds,
 573                                         struct sctp_association *asoc)
 574 {
 575         struct sctp_transport *t;
 576         struct list_head *pos;
 577
 578         list_for_each(pos, &asoc->peer.transport_addr_list) {
 579                 t = list_entry(pos, struct sctp_transport, transports);
 580                 if (timer_pending(&t->T3_rtx_timer) &&
 581                     del_timer(&t->T3_rtx_timer)) {
 582                         sctp_transport_put(t);
 583                 }
 584         }
 585 }
 586
 587
 588 /* Helper function to update the heartbeat timer. */
 589 static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
 590                                      struct sctp_association *asoc,
 591                                      struct sctp_transport *t)
 592 {
 593         /* Update the heartbeat timer.  */
 594         if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 595                 sctp_transport_hold(t);
 596 }
 597
 598 /* Helper function to handle the reception of an HEARTBEAT ACK.  */
 599 static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds,
 600                                   struct sctp_association *asoc,
 601                                   struct sctp_transport *t,
 602                                   struct sctp_chunk *chunk)
 603 {
 604         sctp_sender_hb_info_t *hbinfo;
 605
 606         /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
 607          * HEARTBEAT should clear the error counter of the destination
 608          * transport address to which the HEARTBEAT was sent.
 609          * The association's overall error count is also cleared.
 610          */
 611         t->error_count = 0;
 612         t->asoc->overall_error_count = 0;
 613
 614         /* Mark the destination transport address as active if it is not so
 615          * marked.
 616          */
 617         if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED))
 618                 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
 619                                              SCTP_HEARTBEAT_SUCCESS);
 620
 621         /* The receiver of the HEARTBEAT ACK should also perform an
 622          * RTT measurement for that destination transport address
 623          * using the time value carried in the HEARTBEAT ACK chunk.
 624          * If the transport's rto_pending variable has been cleared,
 625          * it was most likely due to a retransmit.  However, we want
 626          * to re-enable it to properly update the rto.
 627          */
 628         if (t->rto_pending == 0)
 629                 t->rto_pending = 1;
 630
 631         hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
 632         sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
 633
 634         /* Update the heartbeat timer.  */
 635         if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 636                 sctp_transport_hold(t);
 637 }
 638
 639 /* Helper function to do a transport reset at the expiry of the hearbeat
 640  * timer.
 641  */
 642 static void sctp_cmd_transport_reset(sctp_cmd_seq_t *cmds,
 643                                      struct sctp_association *asoc,
 644                                      struct sctp_transport *t)
 645 {
 646         sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
 647
 648         /* Mark one strike against a transport.  */
 649         sctp_do_8_2_transport_strike(asoc, t);
 650 }
 651
 652 /* Helper function to process the process SACK command.  */
 653 static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds,
 654                                  struct sctp_association *asoc,
 655                                  struct sctp_sackhdr *sackh)
 656 {
 657         int err;
 658
 659         if (sctp_outq_sack(&asoc->outqueue, sackh)) {
 660                 /* There are no more TSNs awaiting SACK.  */
 661                 err = sctp_do_sm(SCTP_EVENT_T_OTHER,
 662                                  SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
 663                                  asoc->state, asoc->ep, asoc, NULL,
 664                                  GFP_ATOMIC);
 665         } else {
 666                 /* Windows may have opened, so we need
 667                  * to check if we have DATA to transmit
 668                  */
 669                 err = sctp_outq_flush(&asoc->outqueue, 0);
 670         }
 671
 672         return err;
 673 }
 674
 675 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
 676  * the transport for a shutdown chunk.
 677  */
 678 static void sctp_cmd_setup_t2(sctp_cmd_seq_t *cmds,
 679                               struct sctp_association *asoc,
 680                               struct sctp_chunk *chunk)
 681 {
 682         struct sctp_transport *t;
 683
 684         t = sctp_assoc_choose_shutdown_transport(asoc);
 685         asoc->shutdown_last_sent_to = t;
 686         asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
 687         chunk->transport = t;
 688 }
 689
 690 /* Helper function to change the state of an association. */
 691 static void sctp_cmd_new_state(sctp_cmd_seq_t *cmds,
 692                                struct sctp_association *asoc,
 693                                sctp_state_t state)
 694 {
 695         struct sock *sk = asoc->base.sk;
 696
 697         asoc->state = state;
 698
 699         SCTP_DEBUG_PRINTK("sctp_cmd_new_state: asoc %p[%s]\n",
 700                           asoc, sctp_state_tbl[state]);
 701
 702         if (sctp_style(sk, TCP)) {
 703                 /* Change the sk->sk_state of a TCP-style socket that has
 704                  * sucessfully completed a connect() call.
 705                  */
 706                 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
 707                         sk->sk_state = SCTP_SS_ESTABLISHED;
 708
 709                 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
 710                 if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
 711                     sctp_sstate(sk, ESTABLISHED))
 712                         sk->sk_shutdown |= RCV_SHUTDOWN;
 713         }
 714
 715         if (sctp_state(asoc, COOKIE_WAIT)) {
 716                 /* Reset init timeouts since they may have been
 717                  * increased due to timer expirations.
 718                  */
 719                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
 720                                                 asoc->rto_initial;
 721                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
 722                                                 asoc->rto_initial;
 723         }
 724
 725         if (sctp_state(asoc, ESTABLISHED) ||
 726             sctp_state(asoc, CLOSED) ||
 727             sctp_state(asoc, SHUTDOWN_RECEIVED)) {
 728                 /* Wake up any processes waiting in the asoc's wait queue in
 729                  * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
 730                  */
 731                 if (waitqueue_active(&asoc->wait))
 732                         wake_up_interruptible(&asoc->wait);
 733
 734                 /* Wake up any processes waiting in the sk's sleep queue of
 735                  * a TCP-style or UDP-style peeled-off socket in
 736                  * sctp_wait_for_accept() or sctp_wait_for_packet().
 737                  * For a UDP-style socket, the waiters are woken up by the
 738                  * notifications.
 739                  */
 740                 if (!sctp_style(sk, UDP))
 741                         sk->sk_state_change(sk);
 742         }
 743 }
 744
 745 /* Helper function to delete an association. */
 746 static void sctp_cmd_delete_tcb(sctp_cmd_seq_t *cmds,
 747                                 struct sctp_association *asoc)
 748 {
 749         struct sock *sk = asoc->base.sk;
 750
 751         /* If it is a non-temporary association belonging to a TCP-style
 752          * listening socket that is not closed, do not free it so that accept()
 753          * can pick it up later.
 754          */
 755         if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
 756             (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
 757                 return;
 758
 759         sctp_unhash_established(asoc);
 760         sctp_association_free(asoc);
 761 }
 762
 763 /*
 764  * ADDIP Section 4.1 ASCONF Chunk Procedures
 765  * A4) Start a T-4 RTO timer, using the RTO value of the selected
 766  * destination address (we use active path instead of primary path just
 767  * because primary path may be inactive.
 768  */
 769 static void sctp_cmd_setup_t4(sctp_cmd_seq_t *cmds,
 770                                 struct sctp_association *asoc,
 771                                 struct sctp_chunk *chunk)
 772 {
 773         struct sctp_transport *t;
 774
 775         t = asoc->peer.active_path;
 776         asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
 777         chunk->transport = t;
 778 }
 779
 780 /* Process an incoming Operation Error Chunk. */
 781 static void sctp_cmd_process_operr(sctp_cmd_seq_t *cmds,
 782                                    struct sctp_association *asoc,
 783                                    struct sctp_chunk *chunk)
 784 {
 785         struct sctp_operr_chunk *operr_chunk;
 786         struct sctp_errhdr *err_hdr;
 787
 788         operr_chunk = (struct sctp_operr_chunk *)chunk->chunk_hdr;
 789         err_hdr = &operr_chunk->err_hdr;
 790
 791         switch (err_hdr->cause) {
 792         case SCTP_ERROR_UNKNOWN_CHUNK:
 793         {
 794                 struct sctp_chunkhdr *unk_chunk_hdr;
 795
 796                 unk_chunk_hdr = (struct sctp_chunkhdr *)err_hdr->variable;
 797                 switch (unk_chunk_hdr->type) {
 798                 /* ADDIP 4.1 A9) If the peer responds to an ASCONF with an
 799                  * ERROR chunk reporting that it did not recognized the ASCONF
 800                  * chunk type, the sender of the ASCONF MUST NOT send any
 801                  * further ASCONF chunks and MUST stop its T-4 timer.
 802                  */
 803                 case SCTP_CID_ASCONF:
 804                         asoc->peer.asconf_capable = 0;
 805                         sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
 806                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
 807                         break;
 808                 default:
 809                         break;
 810                 }
 811                 break;
 812         }
 813         default:
 814                 break;
 815         }
 816 }
 817
 818 /* Process variable FWDTSN chunk information. */
 819 static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq,
 820                                     struct sctp_chunk *chunk)
 821 {
 822         struct sctp_fwdtsn_skip *skip;
 823         /* Walk through all the skipped SSNs */
 824         sctp_walk_fwdtsn(skip, chunk) {
 825                 sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
 826         }
 827
 828         return;
 829 }
 830
 831 /* Helper function to remove the association non-primary peer
 832  * transports.
 833  */
 834 static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
 835 {
 836         struct sctp_transport *t;
 837         struct list_head *pos;
 838         struct list_head *temp;
 839
 840         list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
 841                 t = list_entry(pos, struct sctp_transport, transports);
 842                 if (!sctp_cmp_addr_exact(&t->ipaddr,
 843                                          &asoc->peer.primary_addr)) {
 844                         sctp_assoc_del_peer(asoc, &t->ipaddr);
 845                 }
 846         }
 847
 848         return;
 849 }
 850
 851 /* Helper function to set sk_err on a 1-1 style socket. */
 852 static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
 853 {
 854         struct sock *sk = asoc->base.sk;
 855
 856         if (!sctp_style(sk, UDP))
 857                 sk->sk_err = error;
 858 }
 859
 860 /* These three macros allow us to pull the debugging code out of the
 861  * main flow of sctp_do_sm() to keep attention focused on the real
 862  * functionality there.
 863  */
 864 #define DEBUG_PRE \
 865         SCTP_DEBUG_PRINTK("sctp_do_sm prefn: " \
 866                           "ep %p, %s, %s, asoc %p[%s], %s\n", \
 867                           ep, sctp_evttype_tbl[event_type], \
 868                           (*debug_fn)(subtype), asoc, \
 869                           sctp_state_tbl[state], state_fn->name)
 870
 871 #define DEBUG_POST \
 872         SCTP_DEBUG_PRINTK("sctp_do_sm postfn: " \
 873                           "asoc %p, status: %s\n", \
 874                           asoc, sctp_status_tbl[status])
 875
 876 #define DEBUG_POST_SFX \
 877         SCTP_DEBUG_PRINTK("sctp_do_sm post sfx: error %d, asoc %p[%s]\n", \
 878                           error, asoc, \
 879                           sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
 880                           sctp_assoc2id(asoc)))?asoc->state:SCTP_STATE_CLOSED])
 881
 882 /*
 883  * This is the master state machine processing function.
 884  *
 885  * If you want to understand all of lksctp, this is a
 886  * good place to start.
 887  */
 888 int sctp_do_sm(sctp_event_t event_type, sctp_subtype_t subtype,
 889                sctp_state_t state,
 890                struct sctp_endpoint *ep,
 891                struct sctp_association *asoc,
 892                void *event_arg,
 893                gfp_t gfp)
 894 {
 895         sctp_cmd_seq_t commands;
 896         const sctp_sm_table_entry_t *state_fn;
 897         sctp_disposition_t status;
 898         int error = 0;
 899         typedef const char *(printfn_t)(sctp_subtype_t);
 900
 901         static printfn_t *table[] = {
 902                 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
 903         };
 904         printfn_t *debug_fn  __attribute__ ((unused)) = table[event_type];
 905
 906         /* Look up the state function, run it, and then process the
 907          * side effects.  These three steps are the heart of lksctp.
 908          */
 909         state_fn = sctp_sm_lookup_event(event_type, state, subtype);
 910
 911         sctp_init_cmd_seq(&commands);
 912
 913         DEBUG_PRE;
 914         status = (*state_fn->fn)(ep, asoc, subtype, event_arg, &commands);
 915         DEBUG_POST;
 916
 917         error = sctp_side_effects(event_type, subtype, state,
 918                                   ep, asoc, event_arg, status,
 919                                   &commands, gfp);
 920         DEBUG_POST_SFX;
 921
 922         return error;
 923 }
 924
 925 #undef DEBUG_PRE
 926 #undef DEBUG_POST
 927
 928 /*****************************************************************
 929  * This the master state function side effect processing function.
 930  *****************************************************************/
 931 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
 932                              sctp_state_t state,
 933                              struct sctp_endpoint *ep,
 934                              struct sctp_association *asoc,
 935                              void *event_arg,
 936                              sctp_disposition_t status,
 937                              sctp_cmd_seq_t *commands,
 938                              gfp_t gfp)
 939 {
 940         int error;
 941
 942         /* FIXME - Most of the dispositions left today would be categorized
 943          * as "exceptional" dispositions.  For those dispositions, it
 944          * may not be proper to run through any of the commands at all.
 945          * For example, the command interpreter might be run only with
 946          * disposition SCTP_DISPOSITION_CONSUME.
 947          */
 948         if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
 949                                                ep, asoc,
 950                                                event_arg, status,
 951                                                commands, gfp)))
 952                 goto bail;
 953
 954         switch (status) {
 955         case SCTP_DISPOSITION_DISCARD:
 956                 SCTP_DEBUG_PRINTK("Ignored sctp protocol event - state %d, "
 957                                   "event_type %d, event_id %d\n",
 958                                   state, event_type, subtype.chunk);
 959                 break;
 960
 961         case SCTP_DISPOSITION_NOMEM:
 962                 /* We ran out of memory, so we need to discard this
 963                  * packet.
 964                  */
 965                 /* BUG--we should now recover some memory, probably by
 966                  * reneging...
 967                  */
 968                 error = -ENOMEM;
 969                 break;
 970
 971         case SCTP_DISPOSITION_DELETE_TCB:
 972                 /* This should now be a command. */
 973                 break;
 974
 975         case SCTP_DISPOSITION_CONSUME:
 976         case SCTP_DISPOSITION_ABORT:
 977                 /*
 978                  * We should no longer have much work to do here as the
 979                  * real work has been done as explicit commands above.
 980                  */
 981                 break;
 982
 983         case SCTP_DISPOSITION_VIOLATION:
 984                 printk(KERN_ERR "sctp protocol violation state %d "
 985                        "chunkid %d\n", state, subtype.chunk);
 986                 break;
 987
 988         case SCTP_DISPOSITION_NOT_IMPL:
 989                 printk(KERN_WARNING "sctp unimplemented feature in state %d, "
 990                        "event_type %d, event_id %d\n",
 991                        state, event_type, subtype.chunk);
 992                 break;
 993
 994         case SCTP_DISPOSITION_BUG:
 995                 printk(KERN_ERR "sctp bug in state %d, "
 996                        "event_type %d, event_id %d\n",
 997                        state, event_type, subtype.chunk);
 998                 BUG();
 999                 break;
1000
1001         default:
1002                 printk(KERN_ERR "sctp impossible disposition %d "
1003                        "in state %d, event_type %d, event_id %d\n",
1004                        status, state, event_type, subtype.chunk);
1005                 BUG();
1006                 break;
1007         };
1008
1009 bail:
1010         return error;
1011 }
1012
1013 /********************************************************************
1014  * 2nd Level Abstractions
1015  ********************************************************************/
1016
1017 /* This is the side-effect interpreter.  */
1018 static int sctp_cmd_interpreter(sctp_event_t event_type,
1019                                 sctp_subtype_t subtype,
1020                                 sctp_state_t state,
1021                                 struct sctp_endpoint *ep,
1022                                 struct sctp_association *asoc,
1023                                 void *event_arg,
1024                                 sctp_disposition_t status,
1025                                 sctp_cmd_seq_t *commands,
1026                                 gfp_t gfp)
1027 {
1028         int error = 0;
1029         int force;
1030         sctp_cmd_t *cmd;
1031         struct sctp_chunk *new_obj;
1032         struct sctp_chunk *chunk = NULL;
1033         struct sctp_packet *packet;
1034         struct list_head *pos;
1035         struct timer_list *timer;
1036         unsigned long timeout;
1037         struct sctp_transport *t;
1038         struct sctp_sackhdr sackh;
1039         int local_cork = 0;
1040
1041         if (SCTP_EVENT_T_TIMEOUT != event_type)
1042                 chunk = (struct sctp_chunk *) event_arg;
1043
1044         /* Note:  This whole file is a huge candidate for rework.
1045          * For example, each command could either have its own handler, so
1046          * the loop would look like:
1047          *     while (cmds)
1048          *         cmd->handle(x, y, z)
1049          * --jgrimm
1050          */
1051         while (NULL != (cmd = sctp_next_cmd(commands))) {
1052                 switch (cmd->verb) {
1053                 case SCTP_CMD_NOP:
1054                         /* Do nothing. */
1055                         break;
1056
1057                 case SCTP_CMD_NEW_ASOC:
1058                         /* Register a new association.  */
1059                         if (local_cork) {
1060                                 sctp_outq_uncork(&asoc->outqueue);
1061                                 local_cork = 0;
1062                         }
1063                         asoc = cmd->obj.ptr;
1064                         /* Register with the endpoint.  */
1065                         sctp_endpoint_add_asoc(ep, asoc);
1066                         sctp_hash_established(asoc);
1067                         break;
1068
1069                 case SCTP_CMD_UPDATE_ASSOC:
1070                        sctp_assoc_update(asoc, cmd->obj.ptr);
1071                        break;
1072
1073                 case SCTP_CMD_PURGE_OUTQUEUE:
1074                        sctp_outq_teardown(&asoc->outqueue);
1075                        break;
1076
1077                 case SCTP_CMD_DELETE_TCB:
1078                         if (local_cork) {
1079                                 sctp_outq_uncork(&asoc->outqueue);
1080                                 local_cork = 0;
1081                         }
1082                         /* Delete the current association.  */
1083                         sctp_cmd_delete_tcb(commands, asoc);
1084                         asoc = NULL;
1085                         break;
1086
1087                 case SCTP_CMD_NEW_STATE:
1088                         /* Enter a new state.  */
1089                         sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1090                         break;
1091
1092                 case SCTP_CMD_REPORT_TSN:
1093                         /* Record the arrival of a TSN.  */
1094                         sctp_tsnmap_mark(&asoc->peer.tsn_map, cmd->obj.u32);
1095                         break;
1096
1097                 case SCTP_CMD_REPORT_FWDTSN:
1098                         /* Move the Cumulattive TSN Ack ahead. */
1099                         sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32);
1100
1101                         /* Abort any in progress partial delivery. */
1102                         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
1103                         break;
1104
1105                 case SCTP_CMD_PROCESS_FWDTSN:
1106                         sctp_cmd_process_fwdtsn(&asoc->ulpq, cmd->obj.ptr);
1107                         break;
1108
1109                 case SCTP_CMD_GEN_SACK:
1110                         /* Generate a Selective ACK.
1111                          * The argument tells us whether to just count
1112                          * the packet and MAYBE generate a SACK, or
1113                          * force a SACK out.
1114                          */
1115                         force = cmd->obj.i32;
1116                         error = sctp_gen_sack(asoc, force, commands);
1117                         break;
1118
1119                 case SCTP_CMD_PROCESS_SACK:
1120                         /* Process an inbound SACK.  */
1121                         error = sctp_cmd_process_sack(commands, asoc,
1122                                                       cmd->obj.ptr);
1123                         break;
1124
1125                 case SCTP_CMD_GEN_INIT_ACK:
1126                         /* Generate an INIT ACK chunk.  */
1127                         new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1128                                                      0);
1129                         if (!new_obj)
1130                                 goto nomem;
1131
1132                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1133                                         SCTP_CHUNK(new_obj));
1134                         break;
1135
1136                 case SCTP_CMD_PEER_INIT:
1137                         /* Process a unified INIT from the peer.
1138                          * Note: Only used during INIT-ACK processing.  If
1139                          * there is an error just return to the outter
1140                          * layer which will bail.
1141                          */
1142                         error = sctp_cmd_process_init(commands, asoc, chunk,
1143                                                       cmd->obj.ptr, gfp);
1144                         break;
1145
1146                 case SCTP_CMD_GEN_COOKIE_ECHO:
1147                         /* Generate a COOKIE ECHO chunk.  */
1148                         new_obj = sctp_make_cookie_echo(asoc, chunk);
1149                         if (!new_obj) {
1150                                 if (cmd->obj.ptr)
1151                                         sctp_chunk_free(cmd->obj.ptr);
1152                                 goto nomem;
1153                         }
1154                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1155                                         SCTP_CHUNK(new_obj));
1156
1157                         /* If there is an ERROR chunk to be sent along with
1158                          * the COOKIE_ECHO, send it, too.
1159                          */
1160                         if (cmd->obj.ptr)
1161                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1162                                                 SCTP_CHUNK(cmd->obj.ptr));
1163
1164                         /* FIXME - Eventually come up with a cleaner way to
1165                          * enabling COOKIE-ECHO + DATA bundling during
1166                          * multihoming stale cookie scenarios, the following
1167                          * command plays with asoc->peer.retran_path to
1168                          * avoid the problem of sending the COOKIE-ECHO and
1169                          * DATA in different paths, which could result
1170                          * in the association being ABORTed if the DATA chunk
1171                          * is processed first by the server.  Checking the
1172                          * init error counter simply causes this command
1173                          * to be executed only during failed attempts of
1174                          * association establishment.
1175                          */
1176                         if ((asoc->peer.retran_path !=
1177                              asoc->peer.primary_path) &&
1178                             (asoc->init_err_counter > 0)) {
1179                                 sctp_add_cmd_sf(commands,
1180                                                 SCTP_CMD_FORCE_PRIM_RETRAN,
1181                                                 SCTP_NULL());
1182                         }
1183
1184                         break;
1185
1186                 case SCTP_CMD_GEN_SHUTDOWN:
1187                         /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1188                          * Reset error counts.
1189                          */
1190                         asoc->overall_error_count = 0;
1191
1192                         /* Generate a SHUTDOWN chunk.  */
1193                         new_obj = sctp_make_shutdown(asoc, chunk);
1194                         if (!new_obj)
1195                                 goto nomem;
1196                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1197                                         SCTP_CHUNK(new_obj));
1198                         break;
1199
1200                 case SCTP_CMD_CHUNK_ULP:
1201                         /* Send a chunk to the sockets layer.  */
1202                         SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1203                                           "chunk_up:", cmd->obj.ptr,
1204                                           "ulpq:", &asoc->ulpq);
1205                         sctp_ulpq_tail_data(&asoc->ulpq, cmd->obj.ptr,
1206                                             GFP_ATOMIC);
1207                         break;
1208
1209                 case SCTP_CMD_EVENT_ULP:
1210                         /* Send a notification to the sockets layer.  */
1211                         SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1212                                           "event_up:",cmd->obj.ptr,
1213                                           "ulpq:",&asoc->ulpq);
1214                         sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ptr);
1215                         break;
1216
1217                 case SCTP_CMD_REPLY:
1218                         /* If an caller has not already corked, do cork. */
1219                         if (!asoc->outqueue.cork) {
1220                                 sctp_outq_cork(&asoc->outqueue);
1221                                 local_cork = 1;
1222                         }
1223                         /* Send a chunk to our peer.  */
1224                         error = sctp_outq_tail(&asoc->outqueue, cmd->obj.ptr);
1225                         break;
1226
1227                 case SCTP_CMD_SEND_PKT:
1228                         /* Send a full packet to our peer.  */
1229                         packet = cmd->obj.ptr;
1230                         sctp_packet_transmit(packet);
1231                         sctp_ootb_pkt_free(packet);
1232                         break;
1233
1234                 case SCTP_CMD_RETRAN:
1235                         /* Mark a transport for retransmission.  */
1236                         sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1237                                         SCTP_RTXR_T3_RTX);
1238                         break;
1239
1240                 case SCTP_CMD_TRANSMIT:
1241                         /* Kick start transmission. */
1242                         error = sctp_outq_uncork(&asoc->outqueue);
1243                         local_cork = 0;
1244                         break;
1245
1246                 case SCTP_CMD_ECN_CE:
1247                         /* Do delayed CE processing.   */
1248                         sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1249                         break;
1250
1251                 case SCTP_CMD_ECN_ECNE:
1252                         /* Do delayed ECNE processing. */
1253                         new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1254                                                         chunk);
1255                         if (new_obj)
1256                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1257                                                 SCTP_CHUNK(new_obj));
1258                         break;
1259
1260                 case SCTP_CMD_ECN_CWR:
1261                         /* Do delayed CWR processing.  */
1262                         sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1263                         break;
1264
1265                 case SCTP_CMD_SETUP_T2:
1266                         sctp_cmd_setup_t2(commands, asoc, cmd->obj.ptr);
1267                         break;
1268
1269                 case SCTP_CMD_TIMER_START:
1270                         timer = &asoc->timers[cmd->obj.to];
1271                         timeout = asoc->timeouts[cmd->obj.to];
1272                         BUG_ON(!timeout);
1273
1274                         timer->expires = jiffies + timeout;
1275                         sctp_association_hold(asoc);
1276                         add_timer(timer);
1277                         break;
1278
1279                 case SCTP_CMD_TIMER_RESTART:
1280                         timer = &asoc->timers[cmd->obj.to];
1281                         timeout = asoc->timeouts[cmd->obj.to];
1282                         if (!mod_timer(timer, jiffies + timeout))
1283                                 sctp_association_hold(asoc);
1284                         break;
1285
1286                 case SCTP_CMD_TIMER_STOP:
1287                         timer = &asoc->timers[cmd->obj.to];
1288                         if (timer_pending(timer) && del_timer(timer))
1289                                 sctp_association_put(asoc);
1290                         break;
1291
1292                 case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1293                         chunk = cmd->obj.ptr;
1294                         t = sctp_assoc_choose_init_transport(asoc);
1295                         asoc->init_last_sent_to = t;
1296                         chunk->transport = t;
1297                         t->init_sent_count++;
1298                         break;
1299
1300                 case SCTP_CMD_INIT_RESTART:
1301                         /* Do the needed accounting and updates
1302                          * associated with restarting an initialization
1303                          * timer. Only multiply the timeout by two if
1304                          * all transports have been tried at the current
1305                          * timeout.
1306                          */
1307                         t = asoc->init_last_sent_to;
1308                         asoc->init_err_counter++;
1309
1310                         if (t->init_sent_count > (asoc->init_cycle + 1)) {
1311                                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] *= 2;
1312                                 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] >
1313                                     asoc->max_init_timeo) {
1314                                         asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
1315                                                 asoc->max_init_timeo;
1316                                 }
1317                                 asoc->init_cycle++;
1318                                 SCTP_DEBUG_PRINTK(
1319                                         "T1 INIT Timeout adjustment"
1320                                         " init_err_counter: %d"
1321                                         " cycle: %d"
1322                                         " timeout: %ld\n",
1323                                         asoc->init_err_counter,
1324                                         asoc->init_cycle,
1325                                         asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT]);
1326                         }
1327
1328                         sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1329                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1330                         break;
1331
1332                 case SCTP_CMD_COOKIEECHO_RESTART:
1333                         /* Do the needed accounting and updates
1334                          * associated with restarting an initialization
1335                          * timer. Only multiply the timeout by two if
1336                          * all transports have been tried at the current
1337                          * timeout.
1338                          */
1339                         asoc->init_err_counter++;
1340
1341                         asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] *= 2;
1342                         if (asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] >
1343                             asoc->max_init_timeo) {
1344                                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
1345                                         asoc->max_init_timeo;
1346                         }
1347                         SCTP_DEBUG_PRINTK(
1348                                 "T1 COOKIE Timeout adjustment"
1349                                 " init_err_counter: %d"
1350                                 " timeout: %ld\n",
1351                                 asoc->init_err_counter,
1352                                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE]);
1353
1354                         /* If we've sent any data bundled with
1355                          * COOKIE-ECHO we need to resend.
1356                          */
1357                         list_for_each(pos, &asoc->peer.transport_addr_list) {
1358                                 t = list_entry(pos, struct sctp_transport,
1359                                                transports);
1360                                 sctp_retransmit_mark(&asoc->outqueue, t, 0);
1361                         }
1362
1363                         sctp_add_cmd_sf(commands,
1364                                         SCTP_CMD_TIMER_RESTART,
1365                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1366                         break;
1367
1368                 case SCTP_CMD_INIT_FAILED:
1369                         sctp_cmd_init_failed(commands, asoc, cmd->obj.err);
1370                         break;
1371
1372                 case SCTP_CMD_ASSOC_FAILED:
1373                         sctp_cmd_assoc_failed(commands, asoc, event_type,
1374                                               subtype, chunk, cmd->obj.err);
1375                         break;
1376
1377                 case SCTP_CMD_INIT_COUNTER_INC:
1378                         asoc->init_err_counter++;
1379                         break;
1380
1381                 case SCTP_CMD_INIT_COUNTER_RESET:
1382                         asoc->init_err_counter = 0;
1383                         asoc->init_cycle = 0;
1384                         break;
1385
1386                 case SCTP_CMD_REPORT_DUP:
1387                         sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1388                                              cmd->obj.u32);
1389                         break;
1390
1391                 case SCTP_CMD_REPORT_BAD_TAG:
1392                         SCTP_DEBUG_PRINTK("vtag mismatch!\n");
1393                         break;
1394
1395                 case SCTP_CMD_STRIKE:
1396                         /* Mark one strike against a transport.  */
1397                         sctp_do_8_2_transport_strike(asoc, cmd->obj.transport);
1398                         break;
1399
1400                 case SCTP_CMD_TRANSPORT_RESET:
1401                         t = cmd->obj.transport;
1402                         sctp_cmd_transport_reset(commands, asoc, t);
1403                         break;
1404
1405                 case SCTP_CMD_TRANSPORT_ON:
1406                         t = cmd->obj.transport;
1407                         sctp_cmd_transport_on(commands, asoc, t, chunk);
1408                         break;
1409
1410                 case SCTP_CMD_HB_TIMERS_START:
1411                         sctp_cmd_hb_timers_start(commands, asoc);
1412                         break;
1413
1414                 case SCTP_CMD_HB_TIMER_UPDATE:
1415                         t = cmd->obj.transport;
1416                         sctp_cmd_hb_timer_update(commands, asoc, t);
1417                         break;
1418
1419                 case SCTP_CMD_HB_TIMERS_STOP:
1420                         sctp_cmd_hb_timers_stop(commands, asoc);
1421                         break;
1422
1423                 case SCTP_CMD_REPORT_ERROR:
1424                         error = cmd->obj.error;
1425                         break;
1426
1427                 case SCTP_CMD_PROCESS_CTSN:
1428                         /* Dummy up a SACK for processing. */
1429                         sackh.cum_tsn_ack = cmd->obj.be32;
1430                         sackh.a_rwnd = 0;
1431                         sackh.num_gap_ack_blocks = 0;
1432                         sackh.num_dup_tsns = 0;
1433                         sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1434                                         SCTP_SACKH(&sackh));
1435                         break;
1436
1437                 case SCTP_CMD_DISCARD_PACKET:
1438                         /* We need to discard the whole packet.  */
1439                         chunk->pdiscard = 1;
1440                         break;
1441
1442                 case SCTP_CMD_RTO_PENDING:
1443                         t = cmd->obj.transport;
1444                         t->rto_pending = 1;
1445                         break;
1446
1447                 case SCTP_CMD_PART_DELIVER:
1448                         sctp_ulpq_partial_delivery(&asoc->ulpq, cmd->obj.ptr,
1449                                                    GFP_ATOMIC);
1450                         break;
1451
1452                 case SCTP_CMD_RENEGE:
1453                         sctp_ulpq_renege(&asoc->ulpq, cmd->obj.ptr,
1454                                          GFP_ATOMIC);
1455                         break;
1456
1457                 case SCTP_CMD_SETUP_T4:
1458                         sctp_cmd_setup_t4(commands, asoc, cmd->obj.ptr);
1459                         break;
1460
1461                 case SCTP_CMD_PROCESS_OPERR:
1462                         sctp_cmd_process_operr(commands, asoc, chunk);
1463                         break;
1464                 case SCTP_CMD_CLEAR_INIT_TAG:
1465                         asoc->peer.i.init_tag = 0;
1466                         break;
1467                 case SCTP_CMD_DEL_NON_PRIMARY:
1468                         sctp_cmd_del_non_primary(asoc);
1469                         break;
1470                 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1471                         sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1472                         break;
1473                 case SCTP_CMD_FORCE_PRIM_RETRAN:
1474                         t = asoc->peer.retran_path;
1475                         asoc->peer.retran_path = asoc->peer.primary_path;
1476                         error = sctp_outq_uncork(&asoc->outqueue);
1477                         local_cork = 0;
1478                         asoc->peer.retran_path = t;
1479                         break;
1480                 case SCTP_CMD_SET_SK_ERR:
1481                         sctp_cmd_set_sk_err(asoc, cmd->obj.error);
1482                         break;
1483                 default:
1484                         printk(KERN_WARNING "Impossible command: %u, %p\n",
1485                                cmd->verb, cmd->obj.ptr);
1486                         break;
1487                 };
1488                 if (error)
1489                         break;
1490         }
1491
1492 out:
1493         if (local_cork)
1494                 sctp_outq_uncork(&asoc->outqueue);
1495         return error;
1496 nomem:
1497         error = -ENOMEM;
1498         goto out;
1499 }
1500