git.oblomov.eu Git - linux-2.6/blob - net/sctp/sm_sideeffect.c

   1 /* SCTP kernel implementation
   2  * (C) Copyright IBM Corp. 2001, 2004
   3  * Copyright (c) 1999 Cisco, Inc.
   4  * Copyright (c) 1999-2001 Motorola, Inc.
   5  *
   6  * This file is part of the SCTP kernel implementation
   7  *
   8  * These functions work with the state functions in sctp_sm_statefuns.c
   9  * to implement that state operations.  These functions implement the
  10  * steps which require modifying existing data structures.
  11  *
  12  * This SCTP implementation is free software;
  13  * you can redistribute it and/or modify it under the terms of
  14  * the GNU General Public License as published by
  15  * the Free Software Foundation; either version 2, or (at your option)
  16  * any later version.
  17  *
  18  * This SCTP implementation is distributed in the hope that it
  19  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
  20  *                 ************************
  21  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  22  * See the GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with GNU CC; see the file COPYING.  If not, write to
  26  * the Free Software Foundation, 59 Temple Place - Suite 330,
  27  * Boston, MA 02111-1307, USA.
  28  *
  29  * Please send any bug reports or fixes you make to the
  30  * email address(es):
  31  *    lksctp developers <lksctp-developers@lists.sourceforge.net>
  32  *
  33  * Or submit a bug report through the following website:
  34  *    http://www.sf.net/projects/lksctp
  35  *
  36  * Written or modified by:
  37  *    La Monte H.P. Yarroll <piggy@acm.org>
  38  *    Karl Knutson          <karl@athena.chicago.il.us>
  39  *    Jon Grimm             <jgrimm@austin.ibm.com>
  40  *    Hui Huang             <hui.huang@nokia.com>
  41  *    Dajiang Zhang         <dajiang.zhang@nokia.com>
  42  *    Daisy Chang           <daisyc@us.ibm.com>
  43  *    Sridhar Samudrala     <sri@us.ibm.com>
  44  *    Ardelle Fan           <ardelle.fan@intel.com>
  45  *
  46  * Any bugs reported given to us we will try to fix... any fixes shared will
  47  * be incorporated into the next SCTP release.
  48  */
  49
  50 #include <linux/skbuff.h>
  51 #include <linux/types.h>
  52 #include <linux/socket.h>
  53 #include <linux/ip.h>
  54 #include <net/sock.h>
  55 #include <net/sctp/sctp.h>
  56 #include <net/sctp/sm.h>
  57
  58 static int sctp_cmd_interpreter(sctp_event_t event_type,
  59                                 sctp_subtype_t subtype,
  60                                 sctp_state_t state,
  61                                 struct sctp_endpoint *ep,
  62                                 struct sctp_association *asoc,
  63                                 void *event_arg,
  64                                 sctp_disposition_t status,
  65                                 sctp_cmd_seq_t *commands,
  66                                 gfp_t gfp);
  67 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
  68                              sctp_state_t state,
  69                              struct sctp_endpoint *ep,
  70                              struct sctp_association *asoc,
  71                              void *event_arg,
  72                              sctp_disposition_t status,
  73                              sctp_cmd_seq_t *commands,
  74                              gfp_t gfp);
  75
  76 /********************************************************************
  77  * Helper functions
  78  ********************************************************************/
  79
  80 /* A helper function for delayed processing of INET ECN CE bit. */
  81 static void sctp_do_ecn_ce_work(struct sctp_association *asoc,
  82                                 __u32 lowest_tsn)
  83 {
  84         /* Save the TSN away for comparison when we receive CWR */
  85
  86         asoc->last_ecne_tsn = lowest_tsn;
  87         asoc->need_ecne = 1;
  88 }
  89
  90 /* Helper function for delayed processing of SCTP ECNE chunk.  */
  91 /* RFC 2960 Appendix A
  92  *
  93  * RFC 2481 details a specific bit for a sender to send in
  94  * the header of its next outbound TCP segment to indicate to
  95  * its peer that it has reduced its congestion window.  This
  96  * is termed the CWR bit.  For SCTP the same indication is made
  97  * by including the CWR chunk.  This chunk contains one data
  98  * element, i.e. the TSN number that was sent in the ECNE chunk.
  99  * This element represents the lowest TSN number in the datagram
 100  * that was originally marked with the CE bit.
 101  */
 102 static struct sctp_chunk *sctp_do_ecn_ecne_work(struct sctp_association *asoc,
 103                                            __u32 lowest_tsn,
 104                                            struct sctp_chunk *chunk)
 105 {
 106         struct sctp_chunk *repl;
 107
 108         /* Our previously transmitted packet ran into some congestion
 109          * so we should take action by reducing cwnd and ssthresh
 110          * and then ACK our peer that we we've done so by
 111          * sending a CWR.
 112          */
 113
 114         /* First, try to determine if we want to actually lower
 115          * our cwnd variables.  Only lower them if the ECNE looks more
 116          * recent than the last response.
 117          */
 118         if (TSN_lt(asoc->last_cwr_tsn, lowest_tsn)) {
 119                 struct sctp_transport *transport;
 120
 121                 /* Find which transport's congestion variables
 122                  * need to be adjusted.
 123                  */
 124                 transport = sctp_assoc_lookup_tsn(asoc, lowest_tsn);
 125
 126                 /* Update the congestion variables. */
 127                 if (transport)
 128                         sctp_transport_lower_cwnd(transport,
 129                                                   SCTP_LOWER_CWND_ECNE);
 130                 asoc->last_cwr_tsn = lowest_tsn;
 131         }
 132
 133         /* Always try to quiet the other end.  In case of lost CWR,
 134          * resend last_cwr_tsn.
 135          */
 136         repl = sctp_make_cwr(asoc, asoc->last_cwr_tsn, chunk);
 137
 138         /* If we run out of memory, it will look like a lost CWR.  We'll
 139          * get back in sync eventually.
 140          */
 141         return repl;
 142 }
 143
 144 /* Helper function to do delayed processing of ECN CWR chunk.  */
 145 static void sctp_do_ecn_cwr_work(struct sctp_association *asoc,
 146                                  __u32 lowest_tsn)
 147 {
 148         /* Turn off ECNE getting auto-prepended to every outgoing
 149          * packet
 150          */
 151         asoc->need_ecne = 0;
 152 }
 153
 154 /* Generate SACK if necessary.  We call this at the end of a packet.  */
 155 static int sctp_gen_sack(struct sctp_association *asoc, int force,
 156                          sctp_cmd_seq_t *commands)
 157 {
 158         __u32 ctsn, max_tsn_seen;
 159         struct sctp_chunk *sack;
 160         struct sctp_transport *trans = asoc->peer.last_data_from;
 161         int error = 0;
 162
 163         if (force ||
 164             (!trans && (asoc->param_flags & SPP_SACKDELAY_DISABLE)) ||
 165             (trans && (trans->param_flags & SPP_SACKDELAY_DISABLE)))
 166                 asoc->peer.sack_needed = 1;
 167
 168         ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
 169         max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
 170
 171         /* From 12.2 Parameters necessary per association (i.e. the TCB):
 172          *
 173          * Ack State : This flag indicates if the next received packet
 174          *           : is to be responded to with a SACK. ...
 175          *           : When DATA chunks are out of order, SACK's
 176          *           : are not delayed (see Section 6).
 177          *
 178          * [This is actually not mentioned in Section 6, but we
 179          * implement it here anyway. --piggy]
 180          */
 181         if (max_tsn_seen != ctsn)
 182                 asoc->peer.sack_needed = 1;
 183
 184         /* From 6.2  Acknowledgement on Reception of DATA Chunks:
 185          *
 186          * Section 4.2 of [RFC2581] SHOULD be followed. Specifically,
 187          * an acknowledgement SHOULD be generated for at least every
 188          * second packet (not every second DATA chunk) received, and
 189          * SHOULD be generated within 200 ms of the arrival of any
 190          * unacknowledged DATA chunk. ...
 191          */
 192         if (!asoc->peer.sack_needed) {
 193                 asoc->peer.sack_cnt++;
 194
 195                 /* Set the SACK delay timeout based on the
 196                  * SACK delay for the last transport
 197                  * data was received from, or the default
 198                  * for the association.
 199                  */
 200                 if (trans) {
 201                         /* We will need a SACK for the next packet.  */
 202                         if (asoc->peer.sack_cnt >= trans->sackfreq - 1)
 203                                 asoc->peer.sack_needed = 1;
 204
 205                         asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
 206                                 trans->sackdelay;
 207                 } else {
 208                         /* We will need a SACK for the next packet.  */
 209                         if (asoc->peer.sack_cnt >= asoc->sackfreq - 1)
 210                                 asoc->peer.sack_needed = 1;
 211
 212                         asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
 213                                 asoc->sackdelay;
 214                 }
 215
 216                 /* Restart the SACK timer. */
 217                 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
 218                                 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
 219         } else {
 220                 if (asoc->a_rwnd > asoc->rwnd)
 221                         asoc->a_rwnd = asoc->rwnd;
 222                 sack = sctp_make_sack(asoc);
 223                 if (!sack)
 224                         goto nomem;
 225
 226                 asoc->peer.sack_needed = 0;
 227                 asoc->peer.sack_cnt = 0;
 228
 229                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(sack));
 230
 231                 /* Stop the SACK timer.  */
 232                 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
 233                                 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
 234         }
 235
 236         return error;
 237 nomem:
 238         error = -ENOMEM;
 239         return error;
 240 }
 241
 242 /* When the T3-RTX timer expires, it calls this function to create the
 243  * relevant state machine event.
 244  */
 245 void sctp_generate_t3_rtx_event(unsigned long peer)
 246 {
 247         int error;
 248         struct sctp_transport *transport = (struct sctp_transport *) peer;
 249         struct sctp_association *asoc = transport->asoc;
 250
 251         /* Check whether a task is in the sock.  */
 252
 253         sctp_bh_lock_sock(asoc->base.sk);
 254         if (sock_owned_by_user(asoc->base.sk)) {
 255                 SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __func__);
 256
 257                 /* Try again later.  */
 258                 if (!mod_timer(&transport->T3_rtx_timer, jiffies + (HZ/20)))
 259                         sctp_transport_hold(transport);
 260                 goto out_unlock;
 261         }
 262
 263         /* Is this transport really dead and just waiting around for
 264          * the timer to let go of the reference?
 265          */
 266         if (transport->dead)
 267                 goto out_unlock;
 268
 269         /* Run through the state machine.  */
 270         error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
 271                            SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX),
 272                            asoc->state,
 273                            asoc->ep, asoc,
 274                            transport, GFP_ATOMIC);
 275
 276         if (error)
 277                 asoc->base.sk->sk_err = -error;
 278
 279 out_unlock:
 280         sctp_bh_unlock_sock(asoc->base.sk);
 281         sctp_transport_put(transport);
 282 }
 283
 284 /* This is a sa interface for producing timeout events.  It works
 285  * for timeouts which use the association as their parameter.
 286  */
 287 static void sctp_generate_timeout_event(struct sctp_association *asoc,
 288                                         sctp_event_timeout_t timeout_type)
 289 {
 290         int error = 0;
 291
 292         sctp_bh_lock_sock(asoc->base.sk);
 293         if (sock_owned_by_user(asoc->base.sk)) {
 294                 SCTP_DEBUG_PRINTK("%s:Sock is busy: timer %d\n",
 295                                   __func__,
 296                                   timeout_type);
 297
 298                 /* Try again later.  */
 299                 if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20)))
 300                         sctp_association_hold(asoc);
 301                 goto out_unlock;
 302         }
 303
 304         /* Is this association really dead and just waiting around for
 305          * the timer to let go of the reference?
 306          */
 307         if (asoc->base.dead)
 308                 goto out_unlock;
 309
 310         /* Run through the state machine.  */
 311         error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
 312                            SCTP_ST_TIMEOUT(timeout_type),
 313                            asoc->state, asoc->ep, asoc,
 314                            (void *)timeout_type, GFP_ATOMIC);
 315
 316         if (error)
 317                 asoc->base.sk->sk_err = -error;
 318
 319 out_unlock:
 320         sctp_bh_unlock_sock(asoc->base.sk);
 321         sctp_association_put(asoc);
 322 }
 323
 324 static void sctp_generate_t1_cookie_event(unsigned long data)
 325 {
 326         struct sctp_association *asoc = (struct sctp_association *) data;
 327         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
 328 }
 329
 330 static void sctp_generate_t1_init_event(unsigned long data)
 331 {
 332         struct sctp_association *asoc = (struct sctp_association *) data;
 333         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
 334 }
 335
 336 static void sctp_generate_t2_shutdown_event(unsigned long data)
 337 {
 338         struct sctp_association *asoc = (struct sctp_association *) data;
 339         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
 340 }
 341
 342 static void sctp_generate_t4_rto_event(unsigned long data)
 343 {
 344         struct sctp_association *asoc = (struct sctp_association *) data;
 345         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
 346 }
 347
 348 static void sctp_generate_t5_shutdown_guard_event(unsigned long data)
 349 {
 350         struct sctp_association *asoc = (struct sctp_association *)data;
 351         sctp_generate_timeout_event(asoc,
 352                                     SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);
 353
 354 } /* sctp_generate_t5_shutdown_guard_event() */
 355
 356 static void sctp_generate_autoclose_event(unsigned long data)
 357 {
 358         struct sctp_association *asoc = (struct sctp_association *) data;
 359         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE);
 360 }
 361
 362 /* Generate a heart beat event.  If the sock is busy, reschedule.   Make
 363  * sure that the transport is still valid.
 364  */
 365 void sctp_generate_heartbeat_event(unsigned long data)
 366 {
 367         int error = 0;
 368         struct sctp_transport *transport = (struct sctp_transport *) data;
 369         struct sctp_association *asoc = transport->asoc;
 370
 371         sctp_bh_lock_sock(asoc->base.sk);
 372         if (sock_owned_by_user(asoc->base.sk)) {
 373                 SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __func__);
 374
 375                 /* Try again later.  */
 376                 if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20)))
 377                         sctp_transport_hold(transport);
 378                 goto out_unlock;
 379         }
 380
 381         /* Is this structure just waiting around for us to actually
 382          * get destroyed?
 383          */
 384         if (transport->dead)
 385                 goto out_unlock;
 386
 387         error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
 388                            SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
 389                            asoc->state, asoc->ep, asoc,
 390                            transport, GFP_ATOMIC);
 391
 392          if (error)
 393                  asoc->base.sk->sk_err = -error;
 394
 395 out_unlock:
 396         sctp_bh_unlock_sock(asoc->base.sk);
 397         sctp_transport_put(transport);
 398 }
 399
 400 /* Inject a SACK Timeout event into the state machine.  */
 401 static void sctp_generate_sack_event(unsigned long data)
 402 {
 403         struct sctp_association *asoc = (struct sctp_association *) data;
 404         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
 405 }
 406
 407 sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
 408         NULL,
 409         sctp_generate_t1_cookie_event,
 410         sctp_generate_t1_init_event,
 411         sctp_generate_t2_shutdown_event,
 412         NULL,
 413         sctp_generate_t4_rto_event,
 414         sctp_generate_t5_shutdown_guard_event,
 415         NULL,
 416         sctp_generate_sack_event,
 417         sctp_generate_autoclose_event,
 418 };
 419
 420
 421 /* RFC 2960 8.2 Path Failure Detection
 422  *
 423  * When its peer endpoint is multi-homed, an endpoint should keep a
 424  * error counter for each of the destination transport addresses of the
 425  * peer endpoint.
 426  *
 427  * Each time the T3-rtx timer expires on any address, or when a
 428  * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
 429  * the error counter of that destination address will be incremented.
 430  * When the value in the error counter exceeds the protocol parameter
 431  * 'Path.Max.Retrans' of that destination address, the endpoint should
 432  * mark the destination transport address as inactive, and a
 433  * notification SHOULD be sent to the upper layer.
 434  *
 435  */
 436 static void sctp_do_8_2_transport_strike(struct sctp_association *asoc,
 437                                          struct sctp_transport *transport)
 438 {
 439         /* The check for association's overall error counter exceeding the
 440          * threshold is done in the state function.
 441          */
 442         /* When probing UNCONFIRMED addresses, the association overall
 443          * error count is NOT incremented
 444          */
 445         if (transport->state != SCTP_UNCONFIRMED)
 446                 asoc->overall_error_count++;
 447
 448         if (transport->state != SCTP_INACTIVE &&
 449             (transport->error_count++ >= transport->pathmaxrxt)) {
 450                 SCTP_DEBUG_PRINTK_IPADDR("transport_strike:association %p",
 451                                          " transport IP: port:%d failed.\n",
 452                                          asoc,
 453                                          (&transport->ipaddr),
 454                                          ntohs(transport->ipaddr.v4.sin_port));
 455                 sctp_assoc_control_transport(asoc, transport,
 456                                              SCTP_TRANSPORT_DOWN,
 457                                              SCTP_FAILED_THRESHOLD);
 458         }
 459
 460         /* E2) For the destination address for which the timer
 461          * expires, set RTO <- RTO * 2 ("back off the timer").  The
 462          * maximum value discussed in rule C7 above (RTO.max) may be
 463          * used to provide an upper bound to this doubling operation.
 464          */
 465         transport->last_rto = transport->rto;
 466         transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
 467 }
 468
 469 /* Worker routine to handle INIT command failure.  */
 470 static void sctp_cmd_init_failed(sctp_cmd_seq_t *commands,
 471                                  struct sctp_association *asoc,
 472                                  unsigned error)
 473 {
 474         struct sctp_ulpevent *event;
 475
 476         event = sctp_ulpevent_make_assoc_change(asoc,0, SCTP_CANT_STR_ASSOC,
 477                                                 (__u16)error, 0, 0, NULL,
 478                                                 GFP_ATOMIC);
 479
 480         if (event)
 481                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 482                                 SCTP_ULPEVENT(event));
 483
 484         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 485                         SCTP_STATE(SCTP_STATE_CLOSED));
 486
 487         /* SEND_FAILED sent later when cleaning up the association. */
 488         asoc->outqueue.error = error;
 489         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 490 }
 491
 492 /* Worker routine to handle SCTP_CMD_ASSOC_FAILED.  */
 493 static void sctp_cmd_assoc_failed(sctp_cmd_seq_t *commands,
 494                                   struct sctp_association *asoc,
 495                                   sctp_event_t event_type,
 496                                   sctp_subtype_t subtype,
 497                                   struct sctp_chunk *chunk,
 498                                   unsigned error)
 499 {
 500         struct sctp_ulpevent *event;
 501
 502         /* Cancel any partial delivery in progress. */
 503         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
 504
 505         if (event_type == SCTP_EVENT_T_CHUNK && subtype.chunk == SCTP_CID_ABORT)
 506                 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
 507                                                 (__u16)error, 0, 0, chunk,
 508                                                 GFP_ATOMIC);
 509         else
 510                 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
 511                                                 (__u16)error, 0, 0, NULL,
 512                                                 GFP_ATOMIC);
 513         if (event)
 514                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 515                                 SCTP_ULPEVENT(event));
 516
 517         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 518                         SCTP_STATE(SCTP_STATE_CLOSED));
 519
 520         /* SEND_FAILED sent later when cleaning up the association. */
 521         asoc->outqueue.error = error;
 522         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 523 }
 524
 525 /* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
 526  * inside the cookie.  In reality, this is only used for INIT-ACK processing
 527  * since all other cases use "temporary" associations and can do all
 528  * their work in statefuns directly.
 529  */
 530 static int sctp_cmd_process_init(sctp_cmd_seq_t *commands,
 531                                  struct sctp_association *asoc,
 532                                  struct sctp_chunk *chunk,
 533                                  sctp_init_chunk_t *peer_init,
 534                                  gfp_t gfp)
 535 {
 536         int error;
 537
 538         /* We only process the init as a sideeffect in a single
 539          * case.   This is when we process the INIT-ACK.   If we
 540          * fail during INIT processing (due to malloc problems),
 541          * just return the error and stop processing the stack.
 542          */
 543         if (!sctp_process_init(asoc, chunk->chunk_hdr->type,
 544                                sctp_source(chunk), peer_init, gfp))
 545                 error = -ENOMEM;
 546         else
 547                 error = 0;
 548
 549         return error;
 550 }
 551
 552 /* Helper function to break out starting up of heartbeat timers.  */
 553 static void sctp_cmd_hb_timers_start(sctp_cmd_seq_t *cmds,
 554                                      struct sctp_association *asoc)
 555 {
 556         struct sctp_transport *t;
 557
 558         /* Start a heartbeat timer for each transport on the association.
 559          * hold a reference on the transport to make sure none of
 560          * the needed data structures go away.
 561          */
 562         list_for_each_entry(t, &asoc->peer.transport_addr_list, transports) {
 563
 564                 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 565                         sctp_transport_hold(t);
 566         }
 567 }
 568
 569 static void sctp_cmd_hb_timers_stop(sctp_cmd_seq_t *cmds,
 570                                     struct sctp_association *asoc)
 571 {
 572         struct sctp_transport *t;
 573
 574         /* Stop all heartbeat timers. */
 575
 576         list_for_each_entry(t, &asoc->peer.transport_addr_list,
 577                         transports) {
 578                 if (del_timer(&t->hb_timer))
 579                         sctp_transport_put(t);
 580         }
 581 }
 582
 583 /* Helper function to stop any pending T3-RTX timers */
 584 static void sctp_cmd_t3_rtx_timers_stop(sctp_cmd_seq_t *cmds,
 585                                         struct sctp_association *asoc)
 586 {
 587         struct sctp_transport *t;
 588
 589         list_for_each_entry(t, &asoc->peer.transport_addr_list,
 590                         transports) {
 591                 if (timer_pending(&t->T3_rtx_timer) &&
 592                     del_timer(&t->T3_rtx_timer)) {
 593                         sctp_transport_put(t);
 594                 }
 595         }
 596 }
 597
 598
 599 /* Helper function to update the heartbeat timer. */
 600 static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
 601                                      struct sctp_transport *t)
 602 {
 603         /* Update the heartbeat timer.  */
 604         if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 605                 sctp_transport_hold(t);
 606 }
 607
 608 /* Helper function to handle the reception of an HEARTBEAT ACK.  */
 609 static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds,
 610                                   struct sctp_association *asoc,
 611                                   struct sctp_transport *t,
 612                                   struct sctp_chunk *chunk)
 613 {
 614         sctp_sender_hb_info_t *hbinfo;
 615
 616         /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
 617          * HEARTBEAT should clear the error counter of the destination
 618          * transport address to which the HEARTBEAT was sent.
 619          * The association's overall error count is also cleared.
 620          */
 621         t->error_count = 0;
 622         t->asoc->overall_error_count = 0;
 623
 624         /* Mark the destination transport address as active if it is not so
 625          * marked.
 626          */
 627         if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED))
 628                 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
 629                                              SCTP_HEARTBEAT_SUCCESS);
 630
 631         /* The receiver of the HEARTBEAT ACK should also perform an
 632          * RTT measurement for that destination transport address
 633          * using the time value carried in the HEARTBEAT ACK chunk.
 634          * If the transport's rto_pending variable has been cleared,
 635          * it was most likely due to a retransmit.  However, we want
 636          * to re-enable it to properly update the rto.
 637          */
 638         if (t->rto_pending == 0)
 639                 t->rto_pending = 1;
 640
 641         hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
 642         sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
 643
 644         /* Update the heartbeat timer.  */
 645         if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 646                 sctp_transport_hold(t);
 647 }
 648
 649 /* Helper function to do a transport reset at the expiry of the hearbeat
 650  * timer.
 651  */
 652 static void sctp_cmd_transport_reset(sctp_cmd_seq_t *cmds,
 653                                      struct sctp_association *asoc,
 654                                      struct sctp_transport *t)
 655 {
 656         sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
 657
 658         /* Mark one strike against a transport.  */
 659         sctp_do_8_2_transport_strike(asoc, t);
 660 }
 661
 662 /* Helper function to process the process SACK command.  */
 663 static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds,
 664                                  struct sctp_association *asoc,
 665                                  struct sctp_sackhdr *sackh)
 666 {
 667         int err;
 668
 669         if (sctp_outq_sack(&asoc->outqueue, sackh)) {
 670                 /* There are no more TSNs awaiting SACK.  */
 671                 err = sctp_do_sm(SCTP_EVENT_T_OTHER,
 672                                  SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
 673                                  asoc->state, asoc->ep, asoc, NULL,
 674                                  GFP_ATOMIC);
 675         } else {
 676                 /* Windows may have opened, so we need
 677                  * to check if we have DATA to transmit
 678                  */
 679                 err = sctp_outq_flush(&asoc->outqueue, 0);
 680         }
 681
 682         return err;
 683 }
 684
 685 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
 686  * the transport for a shutdown chunk.
 687  */
 688 static void sctp_cmd_setup_t2(sctp_cmd_seq_t *cmds,
 689                               struct sctp_association *asoc,
 690                               struct sctp_chunk *chunk)
 691 {
 692         struct sctp_transport *t;
 693
 694         t = sctp_assoc_choose_shutdown_transport(asoc);
 695         asoc->shutdown_last_sent_to = t;
 696         asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
 697         chunk->transport = t;
 698 }
 699
 700 /* Helper function to change the state of an association. */
 701 static void sctp_cmd_new_state(sctp_cmd_seq_t *cmds,
 702                                struct sctp_association *asoc,
 703                                sctp_state_t state)
 704 {
 705         struct sock *sk = asoc->base.sk;
 706
 707         asoc->state = state;
 708
 709         SCTP_DEBUG_PRINTK("sctp_cmd_new_state: asoc %p[%s]\n",
 710                           asoc, sctp_state_tbl[state]);
 711
 712         if (sctp_style(sk, TCP)) {
 713                 /* Change the sk->sk_state of a TCP-style socket that has
 714                  * sucessfully completed a connect() call.
 715                  */
 716                 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
 717                         sk->sk_state = SCTP_SS_ESTABLISHED;
 718
 719                 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
 720                 if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
 721                     sctp_sstate(sk, ESTABLISHED))
 722                         sk->sk_shutdown |= RCV_SHUTDOWN;
 723         }
 724
 725         if (sctp_state(asoc, COOKIE_WAIT)) {
 726                 /* Reset init timeouts since they may have been
 727                  * increased due to timer expirations.
 728                  */
 729                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
 730                                                 asoc->rto_initial;
 731                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
 732                                                 asoc->rto_initial;
 733         }
 734
 735         if (sctp_state(asoc, ESTABLISHED) ||
 736             sctp_state(asoc, CLOSED) ||
 737             sctp_state(asoc, SHUTDOWN_RECEIVED)) {
 738                 /* Wake up any processes waiting in the asoc's wait queue in
 739                  * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
 740                  */
 741                 if (waitqueue_active(&asoc->wait))
 742                         wake_up_interruptible(&asoc->wait);
 743
 744                 /* Wake up any processes waiting in the sk's sleep queue of
 745                  * a TCP-style or UDP-style peeled-off socket in
 746                  * sctp_wait_for_accept() or sctp_wait_for_packet().
 747                  * For a UDP-style socket, the waiters are woken up by the
 748                  * notifications.
 749                  */
 750                 if (!sctp_style(sk, UDP))
 751                         sk->sk_state_change(sk);
 752         }
 753 }
 754
 755 /* Helper function to delete an association. */
 756 static void sctp_cmd_delete_tcb(sctp_cmd_seq_t *cmds,
 757                                 struct sctp_association *asoc)
 758 {
 759         struct sock *sk = asoc->base.sk;
 760
 761         /* If it is a non-temporary association belonging to a TCP-style
 762          * listening socket that is not closed, do not free it so that accept()
 763          * can pick it up later.
 764          */
 765         if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
 766             (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
 767                 return;
 768
 769         sctp_unhash_established(asoc);
 770         sctp_association_free(asoc);
 771 }
 772
 773 /*
 774  * ADDIP Section 4.1 ASCONF Chunk Procedures
 775  * A4) Start a T-4 RTO timer, using the RTO value of the selected
 776  * destination address (we use active path instead of primary path just
 777  * because primary path may be inactive.
 778  */
 779 static void sctp_cmd_setup_t4(sctp_cmd_seq_t *cmds,
 780                                 struct sctp_association *asoc,
 781                                 struct sctp_chunk *chunk)
 782 {
 783         struct sctp_transport *t;
 784
 785         t = asoc->peer.active_path;
 786         asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
 787         chunk->transport = t;
 788 }
 789
 790 /* Process an incoming Operation Error Chunk. */
 791 static void sctp_cmd_process_operr(sctp_cmd_seq_t *cmds,
 792                                    struct sctp_association *asoc,
 793                                    struct sctp_chunk *chunk)
 794 {
 795         struct sctp_operr_chunk *operr_chunk;
 796         struct sctp_errhdr *err_hdr;
 797
 798         operr_chunk = (struct sctp_operr_chunk *)chunk->chunk_hdr;
 799         err_hdr = &operr_chunk->err_hdr;
 800
 801         switch (err_hdr->cause) {
 802         case SCTP_ERROR_UNKNOWN_CHUNK:
 803         {
 804                 struct sctp_chunkhdr *unk_chunk_hdr;
 805
 806                 unk_chunk_hdr = (struct sctp_chunkhdr *)err_hdr->variable;
 807                 switch (unk_chunk_hdr->type) {
 808                 /* ADDIP 4.1 A9) If the peer responds to an ASCONF with an
 809                  * ERROR chunk reporting that it did not recognized the ASCONF
 810                  * chunk type, the sender of the ASCONF MUST NOT send any
 811                  * further ASCONF chunks and MUST stop its T-4 timer.
 812                  */
 813                 case SCTP_CID_ASCONF:
 814                         asoc->peer.asconf_capable = 0;
 815                         sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
 816                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
 817                         break;
 818                 default:
 819                         break;
 820                 }
 821                 break;
 822         }
 823         default:
 824                 break;
 825         }
 826 }
 827
 828 /* Process variable FWDTSN chunk information. */
 829 static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq,
 830                                     struct sctp_chunk *chunk)
 831 {
 832         struct sctp_fwdtsn_skip *skip;
 833         /* Walk through all the skipped SSNs */
 834         sctp_walk_fwdtsn(skip, chunk) {
 835                 sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
 836         }
 837
 838         return;
 839 }
 840
 841 /* Helper function to remove the association non-primary peer
 842  * transports.
 843  */
 844 static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
 845 {
 846         struct sctp_transport *t;
 847         struct list_head *pos;
 848         struct list_head *temp;
 849
 850         list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
 851                 t = list_entry(pos, struct sctp_transport, transports);
 852                 if (!sctp_cmp_addr_exact(&t->ipaddr,
 853                                          &asoc->peer.primary_addr)) {
 854                         sctp_assoc_del_peer(asoc, &t->ipaddr);
 855                 }
 856         }
 857
 858         return;
 859 }
 860
 861 /* Helper function to set sk_err on a 1-1 style socket. */
 862 static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
 863 {
 864         struct sock *sk = asoc->base.sk;
 865
 866         if (!sctp_style(sk, UDP))
 867                 sk->sk_err = error;
 868 }
 869
 870 /* Helper function to generate an association change event */
 871 static void sctp_cmd_assoc_change(sctp_cmd_seq_t *commands,
 872                                  struct sctp_association *asoc,
 873                                  u8 state)
 874 {
 875         struct sctp_ulpevent *ev;
 876
 877         ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0,
 878                                             asoc->c.sinit_num_ostreams,
 879                                             asoc->c.sinit_max_instreams,
 880                                             NULL, GFP_ATOMIC);
 881         if (ev)
 882                 sctp_ulpq_tail_event(&asoc->ulpq, ev);
 883 }
 884
 885 /* Helper function to generate an adaptation indication event */
 886 static void sctp_cmd_adaptation_ind(sctp_cmd_seq_t *commands,
 887                                     struct sctp_association *asoc)
 888 {
 889         struct sctp_ulpevent *ev;
 890
 891         ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
 892
 893         if (ev)
 894                 sctp_ulpq_tail_event(&asoc->ulpq, ev);
 895 }
 896
 897 /* These three macros allow us to pull the debugging code out of the
 898  * main flow of sctp_do_sm() to keep attention focused on the real
 899  * functionality there.
 900  */
 901 #define DEBUG_PRE \
 902         SCTP_DEBUG_PRINTK("sctp_do_sm prefn: " \
 903                           "ep %p, %s, %s, asoc %p[%s], %s\n", \
 904                           ep, sctp_evttype_tbl[event_type], \
 905                           (*debug_fn)(subtype), asoc, \
 906                           sctp_state_tbl[state], state_fn->name)
 907
 908 #define DEBUG_POST \
 909         SCTP_DEBUG_PRINTK("sctp_do_sm postfn: " \
 910                           "asoc %p, status: %s\n", \
 911                           asoc, sctp_status_tbl[status])
 912
 913 #define DEBUG_POST_SFX \
 914         SCTP_DEBUG_PRINTK("sctp_do_sm post sfx: error %d, asoc %p[%s]\n", \
 915                           error, asoc, \
 916                           sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
 917                           sctp_assoc2id(asoc)))?asoc->state:SCTP_STATE_CLOSED])
 918
 919 /*
 920  * This is the master state machine processing function.
 921  *
 922  * If you want to understand all of lksctp, this is a
 923  * good place to start.
 924  */
 925 int sctp_do_sm(sctp_event_t event_type, sctp_subtype_t subtype,
 926                sctp_state_t state,
 927                struct sctp_endpoint *ep,
 928                struct sctp_association *asoc,
 929                void *event_arg,
 930                gfp_t gfp)
 931 {
 932         sctp_cmd_seq_t commands;
 933         const sctp_sm_table_entry_t *state_fn;
 934         sctp_disposition_t status;
 935         int error = 0;
 936         typedef const char *(printfn_t)(sctp_subtype_t);
 937
 938         static printfn_t *table[] = {
 939                 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
 940         };
 941         printfn_t *debug_fn  __attribute__ ((unused)) = table[event_type];
 942
 943         /* Look up the state function, run it, and then process the
 944          * side effects.  These three steps are the heart of lksctp.
 945          */
 946         state_fn = sctp_sm_lookup_event(event_type, state, subtype);
 947
 948         sctp_init_cmd_seq(&commands);
 949
 950         DEBUG_PRE;
 951         status = (*state_fn->fn)(ep, asoc, subtype, event_arg, &commands);
 952         DEBUG_POST;
 953
 954         error = sctp_side_effects(event_type, subtype, state,
 955                                   ep, asoc, event_arg, status,
 956                                   &commands, gfp);
 957         DEBUG_POST_SFX;
 958
 959         return error;
 960 }
 961
 962 #undef DEBUG_PRE
 963 #undef DEBUG_POST
 964
 965 /*****************************************************************
 966  * This the master state function side effect processing function.
 967  *****************************************************************/
 968 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
 969                              sctp_state_t state,
 970                              struct sctp_endpoint *ep,
 971                              struct sctp_association *asoc,
 972                              void *event_arg,
 973                              sctp_disposition_t status,
 974                              sctp_cmd_seq_t *commands,
 975                              gfp_t gfp)
 976 {
 977         int error;
 978
 979         /* FIXME - Most of the dispositions left today would be categorized
 980          * as "exceptional" dispositions.  For those dispositions, it
 981          * may not be proper to run through any of the commands at all.
 982          * For example, the command interpreter might be run only with
 983          * disposition SCTP_DISPOSITION_CONSUME.
 984          */
 985         if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
 986                                                ep, asoc,
 987                                                event_arg, status,
 988                                                commands, gfp)))
 989                 goto bail;
 990
 991         switch (status) {
 992         case SCTP_DISPOSITION_DISCARD:
 993                 SCTP_DEBUG_PRINTK("Ignored sctp protocol event - state %d, "
 994                                   "event_type %d, event_id %d\n",
 995                                   state, event_type, subtype.chunk);
 996                 break;
 997
 998         case SCTP_DISPOSITION_NOMEM:
 999                 /* We ran out of memory, so we need to discard this
1000                  * packet.
1001                  */
1002                 /* BUG--we should now recover some memory, probably by
1003                  * reneging...
1004                  */
1005                 error = -ENOMEM;
1006                 break;
1007
1008         case SCTP_DISPOSITION_DELETE_TCB:
1009                 /* This should now be a command. */
1010                 break;
1011
1012         case SCTP_DISPOSITION_CONSUME:
1013         case SCTP_DISPOSITION_ABORT:
1014                 /*
1015                  * We should no longer have much work to do here as the
1016                  * real work has been done as explicit commands above.
1017                  */
1018                 break;
1019
1020         case SCTP_DISPOSITION_VIOLATION:
1021                 if (net_ratelimit())
1022                         printk(KERN_ERR "sctp protocol violation state %d "
1023                                "chunkid %d\n", state, subtype.chunk);
1024                 break;
1025
1026         case SCTP_DISPOSITION_NOT_IMPL:
1027                 printk(KERN_WARNING "sctp unimplemented feature in state %d, "
1028                        "event_type %d, event_id %d\n",
1029                        state, event_type, subtype.chunk);
1030                 break;
1031
1032         case SCTP_DISPOSITION_BUG:
1033                 printk(KERN_ERR "sctp bug in state %d, "
1034                        "event_type %d, event_id %d\n",
1035                        state, event_type, subtype.chunk);
1036                 BUG();
1037                 break;
1038
1039         default:
1040                 printk(KERN_ERR "sctp impossible disposition %d "
1041                        "in state %d, event_type %d, event_id %d\n",
1042                        status, state, event_type, subtype.chunk);
1043                 BUG();
1044                 break;
1045         }
1046
1047 bail:
1048         return error;
1049 }
1050
1051 /********************************************************************
1052  * 2nd Level Abstractions
1053  ********************************************************************/
1054
1055 /* This is the side-effect interpreter.  */
1056 static int sctp_cmd_interpreter(sctp_event_t event_type,
1057                                 sctp_subtype_t subtype,
1058                                 sctp_state_t state,
1059                                 struct sctp_endpoint *ep,
1060                                 struct sctp_association *asoc,
1061                                 void *event_arg,
1062                                 sctp_disposition_t status,
1063                                 sctp_cmd_seq_t *commands,
1064                                 gfp_t gfp)
1065 {
1066         int error = 0;
1067         int force;
1068         sctp_cmd_t *cmd;
1069         struct sctp_chunk *new_obj;
1070         struct sctp_chunk *chunk = NULL;
1071         struct sctp_packet *packet;
1072         struct timer_list *timer;
1073         unsigned long timeout;
1074         struct sctp_transport *t;
1075         struct sctp_sackhdr sackh;
1076         int local_cork = 0;
1077
1078         if (SCTP_EVENT_T_TIMEOUT != event_type)
1079                 chunk = (struct sctp_chunk *) event_arg;
1080
1081         /* Note:  This whole file is a huge candidate for rework.
1082          * For example, each command could either have its own handler, so
1083          * the loop would look like:
1084          *     while (cmds)
1085          *         cmd->handle(x, y, z)
1086          * --jgrimm
1087          */
1088         while (NULL != (cmd = sctp_next_cmd(commands))) {
1089                 switch (cmd->verb) {
1090                 case SCTP_CMD_NOP:
1091                         /* Do nothing. */
1092                         break;
1093
1094                 case SCTP_CMD_NEW_ASOC:
1095                         /* Register a new association.  */
1096                         if (local_cork) {
1097                                 sctp_outq_uncork(&asoc->outqueue);
1098                                 local_cork = 0;
1099                         }
1100                         asoc = cmd->obj.ptr;
1101                         /* Register with the endpoint.  */
1102                         sctp_endpoint_add_asoc(ep, asoc);
1103                         sctp_hash_established(asoc);
1104                         break;
1105
1106                 case SCTP_CMD_UPDATE_ASSOC:
1107                        sctp_assoc_update(asoc, cmd->obj.ptr);
1108                        break;
1109
1110                 case SCTP_CMD_PURGE_OUTQUEUE:
1111                        sctp_outq_teardown(&asoc->outqueue);
1112                        break;
1113
1114                 case SCTP_CMD_DELETE_TCB:
1115                         if (local_cork) {
1116                                 sctp_outq_uncork(&asoc->outqueue);
1117                                 local_cork = 0;
1118                         }
1119                         /* Delete the current association.  */
1120                         sctp_cmd_delete_tcb(commands, asoc);
1121                         asoc = NULL;
1122                         break;
1123
1124                 case SCTP_CMD_NEW_STATE:
1125                         /* Enter a new state.  */
1126                         sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1127                         break;
1128
1129                 case SCTP_CMD_REPORT_TSN:
1130                         /* Record the arrival of a TSN.  */
1131                         sctp_tsnmap_mark(&asoc->peer.tsn_map, cmd->obj.u32);
1132                         break;
1133
1134                 case SCTP_CMD_REPORT_FWDTSN:
1135                         /* Move the Cumulattive TSN Ack ahead. */
1136                         sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32);
1137
1138                         /* purge the fragmentation queue */
1139                         sctp_ulpq_reasm_flushtsn(&asoc->ulpq, cmd->obj.u32);
1140
1141                         /* Abort any in progress partial delivery. */
1142                         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
1143                         break;
1144
1145                 case SCTP_CMD_PROCESS_FWDTSN:
1146                         sctp_cmd_process_fwdtsn(&asoc->ulpq, cmd->obj.ptr);
1147                         break;
1148
1149                 case SCTP_CMD_GEN_SACK:
1150                         /* Generate a Selective ACK.
1151                          * The argument tells us whether to just count
1152                          * the packet and MAYBE generate a SACK, or
1153                          * force a SACK out.
1154                          */
1155                         force = cmd->obj.i32;
1156                         error = sctp_gen_sack(asoc, force, commands);
1157                         break;
1158
1159                 case SCTP_CMD_PROCESS_SACK:
1160                         /* Process an inbound SACK.  */
1161                         error = sctp_cmd_process_sack(commands, asoc,
1162                                                       cmd->obj.ptr);
1163                         break;
1164
1165                 case SCTP_CMD_GEN_INIT_ACK:
1166                         /* Generate an INIT ACK chunk.  */
1167                         new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1168                                                      0);
1169                         if (!new_obj)
1170                                 goto nomem;
1171
1172                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1173                                         SCTP_CHUNK(new_obj));
1174                         break;
1175
1176                 case SCTP_CMD_PEER_INIT:
1177                         /* Process a unified INIT from the peer.
1178                          * Note: Only used during INIT-ACK processing.  If
1179                          * there is an error just return to the outter
1180                          * layer which will bail.
1181                          */
1182                         error = sctp_cmd_process_init(commands, asoc, chunk,
1183                                                       cmd->obj.ptr, gfp);
1184                         break;
1185
1186                 case SCTP_CMD_GEN_COOKIE_ECHO:
1187                         /* Generate a COOKIE ECHO chunk.  */
1188                         new_obj = sctp_make_cookie_echo(asoc, chunk);
1189                         if (!new_obj) {
1190                                 if (cmd->obj.ptr)
1191                                         sctp_chunk_free(cmd->obj.ptr);
1192                                 goto nomem;
1193                         }
1194                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1195                                         SCTP_CHUNK(new_obj));
1196
1197                         /* If there is an ERROR chunk to be sent along with
1198                          * the COOKIE_ECHO, send it, too.
1199                          */
1200                         if (cmd->obj.ptr)
1201                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1202                                                 SCTP_CHUNK(cmd->obj.ptr));
1203
1204                         /* FIXME - Eventually come up with a cleaner way to
1205                          * enabling COOKIE-ECHO + DATA bundling during
1206                          * multihoming stale cookie scenarios, the following
1207                          * command plays with asoc->peer.retran_path to
1208                          * avoid the problem of sending the COOKIE-ECHO and
1209                          * DATA in different paths, which could result
1210                          * in the association being ABORTed if the DATA chunk
1211                          * is processed first by the server.  Checking the
1212                          * init error counter simply causes this command
1213                          * to be executed only during failed attempts of
1214                          * association establishment.
1215                          */
1216                         if ((asoc->peer.retran_path !=
1217                              asoc->peer.primary_path) &&
1218                             (asoc->init_err_counter > 0)) {
1219                                 sctp_add_cmd_sf(commands,
1220                                                 SCTP_CMD_FORCE_PRIM_RETRAN,
1221                                                 SCTP_NULL());
1222                         }
1223
1224                         break;
1225
1226                 case SCTP_CMD_GEN_SHUTDOWN:
1227                         /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1228                          * Reset error counts.
1229                          */
1230                         asoc->overall_error_count = 0;
1231
1232                         /* Generate a SHUTDOWN chunk.  */
1233                         new_obj = sctp_make_shutdown(asoc, chunk);
1234                         if (!new_obj)
1235                                 goto nomem;
1236                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1237                                         SCTP_CHUNK(new_obj));
1238                         break;
1239
1240                 case SCTP_CMD_CHUNK_ULP:
1241                         /* Send a chunk to the sockets layer.  */
1242                         SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1243                                           "chunk_up:", cmd->obj.ptr,
1244                                           "ulpq:", &asoc->ulpq);
1245                         sctp_ulpq_tail_data(&asoc->ulpq, cmd->obj.ptr,
1246                                             GFP_ATOMIC);
1247                         break;
1248
1249                 case SCTP_CMD_EVENT_ULP:
1250                         /* Send a notification to the sockets layer.  */
1251                         SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1252                                           "event_up:",cmd->obj.ptr,
1253                                           "ulpq:",&asoc->ulpq);
1254                         sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ptr);
1255                         break;
1256
1257                 case SCTP_CMD_REPLY:
1258                         /* If an caller has not already corked, do cork. */
1259                         if (!asoc->outqueue.cork) {
1260                                 sctp_outq_cork(&asoc->outqueue);
1261                                 local_cork = 1;
1262                         }
1263                         /* Send a chunk to our peer.  */
1264                         error = sctp_outq_tail(&asoc->outqueue, cmd->obj.ptr);
1265                         break;
1266
1267                 case SCTP_CMD_SEND_PKT:
1268                         /* Send a full packet to our peer.  */
1269                         packet = cmd->obj.ptr;
1270                         sctp_packet_transmit(packet);
1271                         sctp_ootb_pkt_free(packet);
1272                         break;
1273
1274                 case SCTP_CMD_T1_RETRAN:
1275                         /* Mark a transport for retransmission.  */
1276                         sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1277                                         SCTP_RTXR_T1_RTX);
1278                         break;
1279
1280                 case SCTP_CMD_RETRAN:
1281                         /* Mark a transport for retransmission.  */
1282                         sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1283                                         SCTP_RTXR_T3_RTX);
1284                         break;
1285
1286                 case SCTP_CMD_TRANSMIT:
1287                         /* Kick start transmission. */
1288                         error = sctp_outq_uncork(&asoc->outqueue);
1289                         local_cork = 0;
1290                         break;
1291
1292                 case SCTP_CMD_ECN_CE:
1293                         /* Do delayed CE processing.   */
1294                         sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1295                         break;
1296
1297                 case SCTP_CMD_ECN_ECNE:
1298                         /* Do delayed ECNE processing. */
1299                         new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1300                                                         chunk);
1301                         if (new_obj)
1302                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1303                                                 SCTP_CHUNK(new_obj));
1304                         break;
1305
1306                 case SCTP_CMD_ECN_CWR:
1307                         /* Do delayed CWR processing.  */
1308                         sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1309                         break;
1310
1311                 case SCTP_CMD_SETUP_T2:
1312                         sctp_cmd_setup_t2(commands, asoc, cmd->obj.ptr);
1313                         break;
1314
1315                 case SCTP_CMD_TIMER_START:
1316                         timer = &asoc->timers[cmd->obj.to];
1317                         timeout = asoc->timeouts[cmd->obj.to];
1318                         BUG_ON(!timeout);
1319
1320                         timer->expires = jiffies + timeout;
1321                         sctp_association_hold(asoc);
1322                         add_timer(timer);
1323                         break;
1324
1325                 case SCTP_CMD_TIMER_RESTART:
1326                         timer = &asoc->timers[cmd->obj.to];
1327                         timeout = asoc->timeouts[cmd->obj.to];
1328                         if (!mod_timer(timer, jiffies + timeout))
1329                                 sctp_association_hold(asoc);
1330                         break;
1331
1332                 case SCTP_CMD_TIMER_STOP:
1333                         timer = &asoc->timers[cmd->obj.to];
1334                         if (timer_pending(timer) && del_timer(timer))
1335                                 sctp_association_put(asoc);
1336                         break;
1337
1338                 case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1339                         chunk = cmd->obj.ptr;
1340                         t = sctp_assoc_choose_init_transport(asoc);
1341                         asoc->init_last_sent_to = t;
1342                         chunk->transport = t;
1343                         t->init_sent_count++;
1344                         break;
1345
1346                 case SCTP_CMD_INIT_RESTART:
1347                         /* Do the needed accounting and updates
1348                          * associated with restarting an initialization
1349                          * timer. Only multiply the timeout by two if
1350                          * all transports have been tried at the current
1351                          * timeout.
1352                          */
1353                         t = asoc->init_last_sent_to;
1354                         asoc->init_err_counter++;
1355
1356                         if (t->init_sent_count > (asoc->init_cycle + 1)) {
1357                                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] *= 2;
1358                                 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] >
1359                                     asoc->max_init_timeo) {
1360                                         asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
1361                                                 asoc->max_init_timeo;
1362                                 }
1363                                 asoc->init_cycle++;
1364                                 SCTP_DEBUG_PRINTK(
1365                                         "T1 INIT Timeout adjustment"
1366                                         " init_err_counter: %d"
1367                                         " cycle: %d"
1368                                         " timeout: %ld\n",
1369                                         asoc->init_err_counter,
1370                                         asoc->init_cycle,
1371                                         asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT]);
1372                         }
1373
1374                         sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1375                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1376                         break;
1377
1378                 case SCTP_CMD_COOKIEECHO_RESTART:
1379                         /* Do the needed accounting and updates
1380                          * associated with restarting an initialization
1381                          * timer. Only multiply the timeout by two if
1382                          * all transports have been tried at the current
1383                          * timeout.
1384                          */
1385                         asoc->init_err_counter++;
1386
1387                         asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] *= 2;
1388                         if (asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] >
1389                             asoc->max_init_timeo) {
1390                                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
1391                                         asoc->max_init_timeo;
1392                         }
1393                         SCTP_DEBUG_PRINTK(
1394                                 "T1 COOKIE Timeout adjustment"
1395                                 " init_err_counter: %d"
1396                                 " timeout: %ld\n",
1397                                 asoc->init_err_counter,
1398                                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE]);
1399
1400                         /* If we've sent any data bundled with
1401                          * COOKIE-ECHO we need to resend.
1402                          */
1403                         list_for_each_entry(t, &asoc->peer.transport_addr_list,
1404                                         transports) {
1405                                 sctp_retransmit_mark(&asoc->outqueue, t,
1406                                             SCTP_RTXR_T1_RTX);
1407                         }
1408
1409                         sctp_add_cmd_sf(commands,
1410                                         SCTP_CMD_TIMER_RESTART,
1411                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1412                         break;
1413
1414                 case SCTP_CMD_INIT_FAILED:
1415                         sctp_cmd_init_failed(commands, asoc, cmd->obj.err);
1416                         break;
1417
1418                 case SCTP_CMD_ASSOC_FAILED:
1419                         sctp_cmd_assoc_failed(commands, asoc, event_type,
1420                                               subtype, chunk, cmd->obj.err);
1421                         break;
1422
1423                 case SCTP_CMD_INIT_COUNTER_INC:
1424                         asoc->init_err_counter++;
1425                         break;
1426
1427                 case SCTP_CMD_INIT_COUNTER_RESET:
1428                         asoc->init_err_counter = 0;
1429                         asoc->init_cycle = 0;
1430                         break;
1431
1432                 case SCTP_CMD_REPORT_DUP:
1433                         sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1434                                              cmd->obj.u32);
1435                         break;
1436
1437                 case SCTP_CMD_REPORT_BAD_TAG:
1438                         SCTP_DEBUG_PRINTK("vtag mismatch!\n");
1439                         break;
1440
1441                 case SCTP_CMD_STRIKE:
1442                         /* Mark one strike against a transport.  */
1443                         sctp_do_8_2_transport_strike(asoc, cmd->obj.transport);
1444                         break;
1445
1446                 case SCTP_CMD_TRANSPORT_RESET:
1447                         t = cmd->obj.transport;
1448                         sctp_cmd_transport_reset(commands, asoc, t);
1449                         break;
1450
1451                 case SCTP_CMD_TRANSPORT_ON:
1452                         t = cmd->obj.transport;
1453                         sctp_cmd_transport_on(commands, asoc, t, chunk);
1454                         break;
1455
1456                 case SCTP_CMD_HB_TIMERS_START:
1457                         sctp_cmd_hb_timers_start(commands, asoc);
1458                         break;
1459
1460                 case SCTP_CMD_HB_TIMER_UPDATE:
1461                         t = cmd->obj.transport;
1462                         sctp_cmd_hb_timer_update(commands, t);
1463                         break;
1464
1465                 case SCTP_CMD_HB_TIMERS_STOP:
1466                         sctp_cmd_hb_timers_stop(commands, asoc);
1467                         break;
1468
1469                 case SCTP_CMD_REPORT_ERROR:
1470                         error = cmd->obj.error;
1471                         break;
1472
1473                 case SCTP_CMD_PROCESS_CTSN:
1474                         /* Dummy up a SACK for processing. */
1475                         sackh.cum_tsn_ack = cmd->obj.be32;
1476                         sackh.a_rwnd = 0;
1477                         sackh.num_gap_ack_blocks = 0;
1478                         sackh.num_dup_tsns = 0;
1479                         sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1480                                         SCTP_SACKH(&sackh));
1481                         break;
1482
1483                 case SCTP_CMD_DISCARD_PACKET:
1484                         /* We need to discard the whole packet.  */
1485                         chunk->pdiscard = 1;
1486                         break;
1487
1488                 case SCTP_CMD_RTO_PENDING:
1489                         t = cmd->obj.transport;
1490                         t->rto_pending = 1;
1491                         break;
1492
1493                 case SCTP_CMD_PART_DELIVER:
1494                         sctp_ulpq_partial_delivery(&asoc->ulpq, cmd->obj.ptr,
1495                                                    GFP_ATOMIC);
1496                         break;
1497
1498                 case SCTP_CMD_RENEGE:
1499                         sctp_ulpq_renege(&asoc->ulpq, cmd->obj.ptr,
1500                                          GFP_ATOMIC);
1501                         break;
1502
1503                 case SCTP_CMD_SETUP_T4:
1504                         sctp_cmd_setup_t4(commands, asoc, cmd->obj.ptr);
1505                         break;
1506
1507                 case SCTP_CMD_PROCESS_OPERR:
1508                         sctp_cmd_process_operr(commands, asoc, chunk);
1509                         break;
1510                 case SCTP_CMD_CLEAR_INIT_TAG:
1511                         asoc->peer.i.init_tag = 0;
1512                         break;
1513                 case SCTP_CMD_DEL_NON_PRIMARY:
1514                         sctp_cmd_del_non_primary(asoc);
1515                         break;
1516                 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1517                         sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1518                         break;
1519                 case SCTP_CMD_FORCE_PRIM_RETRAN:
1520                         t = asoc->peer.retran_path;
1521                         asoc->peer.retran_path = asoc->peer.primary_path;
1522                         error = sctp_outq_uncork(&asoc->outqueue);
1523                         local_cork = 0;
1524                         asoc->peer.retran_path = t;
1525                         break;
1526                 case SCTP_CMD_SET_SK_ERR:
1527                         sctp_cmd_set_sk_err(asoc, cmd->obj.error);
1528                         break;
1529                 case SCTP_CMD_ASSOC_CHANGE:
1530                         sctp_cmd_assoc_change(commands, asoc,
1531                                               cmd->obj.u8);
1532                         break;
1533                 case SCTP_CMD_ADAPTATION_IND:
1534                         sctp_cmd_adaptation_ind(commands, asoc);
1535                         break;
1536
1537                 case SCTP_CMD_ASSOC_SHKEY:
1538                         error = sctp_auth_asoc_init_active_key(asoc,
1539                                                 GFP_ATOMIC);
1540                         break;
1541                 case SCTP_CMD_UPDATE_INITTAG:
1542                         asoc->peer.i.init_tag = cmd->obj.u32;
1543                         break;
1544
1545                 default:
1546                         printk(KERN_WARNING "Impossible command: %u, %p\n",
1547                                cmd->verb, cmd->obj.ptr);
1548                         break;
1549                 }
1550
1551                 if (error)
1552                         break;
1553         }
1554
1555 out:
1556         if (local_cork)
1557                 sctp_outq_uncork(&asoc->outqueue);
1558         return error;
1559 nomem:
1560         error = -ENOMEM;
1561         goto out;
1562 }
1563