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   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                 asoc->a_rwnd = asoc->rwnd;
 221                 sack = sctp_make_sack(asoc);
 222                 if (!sack)
 223                         goto nomem;
 224
 225                 asoc->peer.sack_needed = 0;
 226                 asoc->peer.sack_cnt = 0;
 227
 228                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(sack));
 229
 230                 /* Stop the SACK timer.  */
 231                 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
 232                                 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
 233         }
 234
 235         return error;
 236 nomem:
 237         error = -ENOMEM;
 238         return error;
 239 }
 240
 241 /* When the T3-RTX timer expires, it calls this function to create the
 242  * relevant state machine event.
 243  */
 244 void sctp_generate_t3_rtx_event(unsigned long peer)
 245 {
 246         int error;
 247         struct sctp_transport *transport = (struct sctp_transport *) peer;
 248         struct sctp_association *asoc = transport->asoc;
 249
 250         /* Check whether a task is in the sock.  */
 251
 252         sctp_bh_lock_sock(asoc->base.sk);
 253         if (sock_owned_by_user(asoc->base.sk)) {
 254                 SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __func__);
 255
 256                 /* Try again later.  */
 257                 if (!mod_timer(&transport->T3_rtx_timer, jiffies + (HZ/20)))
 258                         sctp_transport_hold(transport);
 259                 goto out_unlock;
 260         }
 261
 262         /* Is this transport really dead and just waiting around for
 263          * the timer to let go of the reference?
 264          */
 265         if (transport->dead)
 266                 goto out_unlock;
 267
 268         /* Run through the state machine.  */
 269         error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
 270                            SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX),
 271                            asoc->state,
 272                            asoc->ep, asoc,
 273                            transport, GFP_ATOMIC);
 274
 275         if (error)
 276                 asoc->base.sk->sk_err = -error;
 277
 278 out_unlock:
 279         sctp_bh_unlock_sock(asoc->base.sk);
 280         sctp_transport_put(transport);
 281 }
 282
 283 /* This is a sa interface for producing timeout events.  It works
 284  * for timeouts which use the association as their parameter.
 285  */
 286 static void sctp_generate_timeout_event(struct sctp_association *asoc,
 287                                         sctp_event_timeout_t timeout_type)
 288 {
 289         int error = 0;
 290
 291         sctp_bh_lock_sock(asoc->base.sk);
 292         if (sock_owned_by_user(asoc->base.sk)) {
 293                 SCTP_DEBUG_PRINTK("%s:Sock is busy: timer %d\n",
 294                                   __func__,
 295                                   timeout_type);
 296
 297                 /* Try again later.  */
 298                 if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20)))
 299                         sctp_association_hold(asoc);
 300                 goto out_unlock;
 301         }
 302
 303         /* Is this association really dead and just waiting around for
 304          * the timer to let go of the reference?
 305          */
 306         if (asoc->base.dead)
 307                 goto out_unlock;
 308
 309         /* Run through the state machine.  */
 310         error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
 311                            SCTP_ST_TIMEOUT(timeout_type),
 312                            asoc->state, asoc->ep, asoc,
 313                            (void *)timeout_type, GFP_ATOMIC);
 314
 315         if (error)
 316                 asoc->base.sk->sk_err = -error;
 317
 318 out_unlock:
 319         sctp_bh_unlock_sock(asoc->base.sk);
 320         sctp_association_put(asoc);
 321 }
 322
 323 static void sctp_generate_t1_cookie_event(unsigned long data)
 324 {
 325         struct sctp_association *asoc = (struct sctp_association *) data;
 326         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
 327 }
 328
 329 static void sctp_generate_t1_init_event(unsigned long data)
 330 {
 331         struct sctp_association *asoc = (struct sctp_association *) data;
 332         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
 333 }
 334
 335 static void sctp_generate_t2_shutdown_event(unsigned long data)
 336 {
 337         struct sctp_association *asoc = (struct sctp_association *) data;
 338         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
 339 }
 340
 341 static void sctp_generate_t4_rto_event(unsigned long data)
 342 {
 343         struct sctp_association *asoc = (struct sctp_association *) data;
 344         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
 345 }
 346
 347 static void sctp_generate_t5_shutdown_guard_event(unsigned long data)
 348 {
 349         struct sctp_association *asoc = (struct sctp_association *)data;
 350         sctp_generate_timeout_event(asoc,
 351                                     SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);
 352
 353 } /* sctp_generate_t5_shutdown_guard_event() */
 354
 355 static void sctp_generate_autoclose_event(unsigned long data)
 356 {
 357         struct sctp_association *asoc = (struct sctp_association *) data;
 358         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE);
 359 }
 360
 361 /* Generate a heart beat event.  If the sock is busy, reschedule.   Make
 362  * sure that the transport is still valid.
 363  */
 364 void sctp_generate_heartbeat_event(unsigned long data)
 365 {
 366         int error = 0;
 367         struct sctp_transport *transport = (struct sctp_transport *) data;
 368         struct sctp_association *asoc = transport->asoc;
 369
 370         sctp_bh_lock_sock(asoc->base.sk);
 371         if (sock_owned_by_user(asoc->base.sk)) {
 372                 SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __func__);
 373
 374                 /* Try again later.  */
 375                 if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20)))
 376                         sctp_transport_hold(transport);
 377                 goto out_unlock;
 378         }
 379
 380         /* Is this structure just waiting around for us to actually
 381          * get destroyed?
 382          */
 383         if (transport->dead)
 384                 goto out_unlock;
 385
 386         error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
 387                            SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
 388                            asoc->state, asoc->ep, asoc,
 389                            transport, GFP_ATOMIC);
 390
 391          if (error)
 392                  asoc->base.sk->sk_err = -error;
 393
 394 out_unlock:
 395         sctp_bh_unlock_sock(asoc->base.sk);
 396         sctp_transport_put(transport);
 397 }
 398
 399 /* Inject a SACK Timeout event into the state machine.  */
 400 static void sctp_generate_sack_event(unsigned long data)
 401 {
 402         struct sctp_association *asoc = (struct sctp_association *) data;
 403         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
 404 }
 405
 406 sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
 407         NULL,
 408         sctp_generate_t1_cookie_event,
 409         sctp_generate_t1_init_event,
 410         sctp_generate_t2_shutdown_event,
 411         NULL,
 412         sctp_generate_t4_rto_event,
 413         sctp_generate_t5_shutdown_guard_event,
 414         NULL,
 415         sctp_generate_sack_event,
 416         sctp_generate_autoclose_event,
 417 };
 418
 419
 420 /* RFC 2960 8.2 Path Failure Detection
 421  *
 422  * When its peer endpoint is multi-homed, an endpoint should keep a
 423  * error counter for each of the destination transport addresses of the
 424  * peer endpoint.
 425  *
 426  * Each time the T3-rtx timer expires on any address, or when a
 427  * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
 428  * the error counter of that destination address will be incremented.
 429  * When the value in the error counter exceeds the protocol parameter
 430  * 'Path.Max.Retrans' of that destination address, the endpoint should
 431  * mark the destination transport address as inactive, and a
 432  * notification SHOULD be sent to the upper layer.
 433  *
 434  */
 435 static void sctp_do_8_2_transport_strike(struct sctp_association *asoc,
 436                                          struct sctp_transport *transport,
 437                                          int is_hb)
 438 {
 439         /* The check for association's overall error counter exceeding the
 440          * threshold is done in the state function.
 441          */
 442         /* We are here due to a timer expiration.  If the timer was
 443          * not a HEARTBEAT, then normal error tracking is done.
 444          * If the timer was a heartbeat, we only increment error counts
 445          * when we already have an outstanding HEARTBEAT that has not
 446          * been acknowledged.
 447          * Additionaly, some tranport states inhibit error increments.
 448          */
 449         if (!is_hb) {
 450                 asoc->overall_error_count++;
 451                 if (transport->state != SCTP_INACTIVE)
 452                         transport->error_count++;
 453          } else if (transport->hb_sent) {
 454                 if (transport->state != SCTP_UNCONFIRMED)
 455                         asoc->overall_error_count++;
 456                 if (transport->state != SCTP_INACTIVE)
 457                         transport->error_count++;
 458         }
 459
 460         if (transport->state != SCTP_INACTIVE &&
 461             (transport->error_count > transport->pathmaxrxt)) {
 462                 SCTP_DEBUG_PRINTK_IPADDR("transport_strike:association %p",
 463                                          " transport IP: port:%d failed.\n",
 464                                          asoc,
 465                                          (&transport->ipaddr),
 466                                          ntohs(transport->ipaddr.v4.sin_port));
 467                 sctp_assoc_control_transport(asoc, transport,
 468                                              SCTP_TRANSPORT_DOWN,
 469                                              SCTP_FAILED_THRESHOLD);
 470         }
 471
 472         /* E2) For the destination address for which the timer
 473          * expires, set RTO <- RTO * 2 ("back off the timer").  The
 474          * maximum value discussed in rule C7 above (RTO.max) may be
 475          * used to provide an upper bound to this doubling operation.
 476          *
 477          * Special Case:  the first HB doesn't trigger exponential backoff.
 478          * The first unacknowleged HB triggers it.  We do this with a flag
 479          * that indicates that we have an outstanding HB.
 480          */
 481         if (!is_hb || transport->hb_sent) {
 482                 transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
 483         }
 484 }
 485
 486 /* Worker routine to handle INIT command failure.  */
 487 static void sctp_cmd_init_failed(sctp_cmd_seq_t *commands,
 488                                  struct sctp_association *asoc,
 489                                  unsigned error)
 490 {
 491         struct sctp_ulpevent *event;
 492
 493         event = sctp_ulpevent_make_assoc_change(asoc,0, SCTP_CANT_STR_ASSOC,
 494                                                 (__u16)error, 0, 0, NULL,
 495                                                 GFP_ATOMIC);
 496
 497         if (event)
 498                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 499                                 SCTP_ULPEVENT(event));
 500
 501         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 502                         SCTP_STATE(SCTP_STATE_CLOSED));
 503
 504         /* SEND_FAILED sent later when cleaning up the association. */
 505         asoc->outqueue.error = error;
 506         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 507 }
 508
 509 /* Worker routine to handle SCTP_CMD_ASSOC_FAILED.  */
 510 static void sctp_cmd_assoc_failed(sctp_cmd_seq_t *commands,
 511                                   struct sctp_association *asoc,
 512                                   sctp_event_t event_type,
 513                                   sctp_subtype_t subtype,
 514                                   struct sctp_chunk *chunk,
 515                                   unsigned error)
 516 {
 517         struct sctp_ulpevent *event;
 518
 519         /* Cancel any partial delivery in progress. */
 520         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
 521
 522         if (event_type == SCTP_EVENT_T_CHUNK && subtype.chunk == SCTP_CID_ABORT)
 523                 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
 524                                                 (__u16)error, 0, 0, chunk,
 525                                                 GFP_ATOMIC);
 526         else
 527                 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
 528                                                 (__u16)error, 0, 0, NULL,
 529                                                 GFP_ATOMIC);
 530         if (event)
 531                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 532                                 SCTP_ULPEVENT(event));
 533
 534         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 535                         SCTP_STATE(SCTP_STATE_CLOSED));
 536
 537         /* SEND_FAILED sent later when cleaning up the association. */
 538         asoc->outqueue.error = error;
 539         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 540 }
 541
 542 /* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
 543  * inside the cookie.  In reality, this is only used for INIT-ACK processing
 544  * since all other cases use "temporary" associations and can do all
 545  * their work in statefuns directly.
 546  */
 547 static int sctp_cmd_process_init(sctp_cmd_seq_t *commands,
 548                                  struct sctp_association *asoc,
 549                                  struct sctp_chunk *chunk,
 550                                  sctp_init_chunk_t *peer_init,
 551                                  gfp_t gfp)
 552 {
 553         int error;
 554
 555         /* We only process the init as a sideeffect in a single
 556          * case.   This is when we process the INIT-ACK.   If we
 557          * fail during INIT processing (due to malloc problems),
 558          * just return the error and stop processing the stack.
 559          */
 560         if (!sctp_process_init(asoc, chunk->chunk_hdr->type,
 561                                sctp_source(chunk), peer_init, gfp))
 562                 error = -ENOMEM;
 563         else
 564                 error = 0;
 565
 566         return error;
 567 }
 568
 569 /* Helper function to break out starting up of heartbeat timers.  */
 570 static void sctp_cmd_hb_timers_start(sctp_cmd_seq_t *cmds,
 571                                      struct sctp_association *asoc)
 572 {
 573         struct sctp_transport *t;
 574
 575         /* Start a heartbeat timer for each transport on the association.
 576          * hold a reference on the transport to make sure none of
 577          * the needed data structures go away.
 578          */
 579         list_for_each_entry(t, &asoc->peer.transport_addr_list, transports) {
 580
 581                 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 582                         sctp_transport_hold(t);
 583         }
 584 }
 585
 586 static void sctp_cmd_hb_timers_stop(sctp_cmd_seq_t *cmds,
 587                                     struct sctp_association *asoc)
 588 {
 589         struct sctp_transport *t;
 590
 591         /* Stop all heartbeat timers. */
 592
 593         list_for_each_entry(t, &asoc->peer.transport_addr_list,
 594                         transports) {
 595                 if (del_timer(&t->hb_timer))
 596                         sctp_transport_put(t);
 597         }
 598 }
 599
 600 /* Helper function to stop any pending T3-RTX timers */
 601 static void sctp_cmd_t3_rtx_timers_stop(sctp_cmd_seq_t *cmds,
 602                                         struct sctp_association *asoc)
 603 {
 604         struct sctp_transport *t;
 605
 606         list_for_each_entry(t, &asoc->peer.transport_addr_list,
 607                         transports) {
 608                 if (timer_pending(&t->T3_rtx_timer) &&
 609                     del_timer(&t->T3_rtx_timer)) {
 610                         sctp_transport_put(t);
 611                 }
 612         }
 613 }
 614
 615
 616 /* Helper function to update the heartbeat timer. */
 617 static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
 618                                      struct sctp_transport *t)
 619 {
 620         /* Update the heartbeat timer.  */
 621         if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 622                 sctp_transport_hold(t);
 623 }
 624
 625 /* Helper function to handle the reception of an HEARTBEAT ACK.  */
 626 static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds,
 627                                   struct sctp_association *asoc,
 628                                   struct sctp_transport *t,
 629                                   struct sctp_chunk *chunk)
 630 {
 631         sctp_sender_hb_info_t *hbinfo;
 632
 633         /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
 634          * HEARTBEAT should clear the error counter of the destination
 635          * transport address to which the HEARTBEAT was sent.
 636          * The association's overall error count is also cleared.
 637          */
 638         t->error_count = 0;
 639         t->asoc->overall_error_count = 0;
 640
 641         /* Clear the hb_sent flag to signal that we had a good
 642          * acknowledgement.
 643          */
 644         t->hb_sent = 0;
 645
 646         /* Mark the destination transport address as active if it is not so
 647          * marked.
 648          */
 649         if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED))
 650                 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
 651                                              SCTP_HEARTBEAT_SUCCESS);
 652
 653         /* The receiver of the HEARTBEAT ACK should also perform an
 654          * RTT measurement for that destination transport address
 655          * using the time value carried in the HEARTBEAT ACK chunk.
 656          * If the transport's rto_pending variable has been cleared,
 657          * it was most likely due to a retransmit.  However, we want
 658          * to re-enable it to properly update the rto.
 659          */
 660         if (t->rto_pending == 0)
 661                 t->rto_pending = 1;
 662
 663         hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
 664         sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
 665
 666         /* Update the heartbeat timer.  */
 667         if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 668                 sctp_transport_hold(t);
 669 }
 670
 671
 672 /* Helper function to process the process SACK command.  */
 673 static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds,
 674                                  struct sctp_association *asoc,
 675                                  struct sctp_sackhdr *sackh)
 676 {
 677         int err = 0;
 678
 679         if (sctp_outq_sack(&asoc->outqueue, sackh)) {
 680                 /* There are no more TSNs awaiting SACK.  */
 681                 err = sctp_do_sm(SCTP_EVENT_T_OTHER,
 682                                  SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
 683                                  asoc->state, asoc->ep, asoc, NULL,
 684                                  GFP_ATOMIC);
 685         }
 686
 687         return err;
 688 }
 689
 690 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
 691  * the transport for a shutdown chunk.
 692  */
 693 static void sctp_cmd_setup_t2(sctp_cmd_seq_t *cmds,
 694                               struct sctp_association *asoc,
 695                               struct sctp_chunk *chunk)
 696 {
 697         struct sctp_transport *t;
 698
 699         t = sctp_assoc_choose_alter_transport(asoc,
 700                                               asoc->shutdown_last_sent_to);
 701         asoc->shutdown_last_sent_to = t;
 702         asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
 703         chunk->transport = t;
 704 }
 705
 706 /* Helper function to change the state of an association. */
 707 static void sctp_cmd_new_state(sctp_cmd_seq_t *cmds,
 708                                struct sctp_association *asoc,
 709                                sctp_state_t state)
 710 {
 711         struct sock *sk = asoc->base.sk;
 712
 713         asoc->state = state;
 714
 715         SCTP_DEBUG_PRINTK("sctp_cmd_new_state: asoc %p[%s]\n",
 716                           asoc, sctp_state_tbl[state]);
 717
 718         if (sctp_style(sk, TCP)) {
 719                 /* Change the sk->sk_state of a TCP-style socket that has
 720                  * successfully completed a connect() call.
 721                  */
 722                 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
 723                         sk->sk_state = SCTP_SS_ESTABLISHED;
 724
 725                 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
 726                 if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
 727                     sctp_sstate(sk, ESTABLISHED))
 728                         sk->sk_shutdown |= RCV_SHUTDOWN;
 729         }
 730
 731         if (sctp_state(asoc, COOKIE_WAIT)) {
 732                 /* Reset init timeouts since they may have been
 733                  * increased due to timer expirations.
 734                  */
 735                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
 736                                                 asoc->rto_initial;
 737                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
 738                                                 asoc->rto_initial;
 739         }
 740
 741         if (sctp_state(asoc, ESTABLISHED) ||
 742             sctp_state(asoc, CLOSED) ||
 743             sctp_state(asoc, SHUTDOWN_RECEIVED)) {
 744                 /* Wake up any processes waiting in the asoc's wait queue in
 745                  * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
 746                  */
 747                 if (waitqueue_active(&asoc->wait))
 748                         wake_up_interruptible(&asoc->wait);
 749
 750                 /* Wake up any processes waiting in the sk's sleep queue of
 751                  * a TCP-style or UDP-style peeled-off socket in
 752                  * sctp_wait_for_accept() or sctp_wait_for_packet().
 753                  * For a UDP-style socket, the waiters are woken up by the
 754                  * notifications.
 755                  */
 756                 if (!sctp_style(sk, UDP))
 757                         sk->sk_state_change(sk);
 758         }
 759 }
 760
 761 /* Helper function to delete an association. */
 762 static void sctp_cmd_delete_tcb(sctp_cmd_seq_t *cmds,
 763                                 struct sctp_association *asoc)
 764 {
 765         struct sock *sk = asoc->base.sk;
 766
 767         /* If it is a non-temporary association belonging to a TCP-style
 768          * listening socket that is not closed, do not free it so that accept()
 769          * can pick it up later.
 770          */
 771         if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
 772             (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
 773                 return;
 774
 775         sctp_unhash_established(asoc);
 776         sctp_association_free(asoc);
 777 }
 778
 779 /*
 780  * ADDIP Section 4.1 ASCONF Chunk Procedures
 781  * A4) Start a T-4 RTO timer, using the RTO value of the selected
 782  * destination address (we use active path instead of primary path just
 783  * because primary path may be inactive.
 784  */
 785 static void sctp_cmd_setup_t4(sctp_cmd_seq_t *cmds,
 786                                 struct sctp_association *asoc,
 787                                 struct sctp_chunk *chunk)
 788 {
 789         struct sctp_transport *t;
 790
 791         t = sctp_assoc_choose_alter_transport(asoc, chunk->transport);
 792         asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
 793         chunk->transport = t;
 794 }
 795
 796 /* Process an incoming Operation Error Chunk. */
 797 static void sctp_cmd_process_operr(sctp_cmd_seq_t *cmds,
 798                                    struct sctp_association *asoc,
 799                                    struct sctp_chunk *chunk)
 800 {
 801         struct sctp_errhdr *err_hdr;
 802         struct sctp_ulpevent *ev;
 803
 804         while (chunk->chunk_end > chunk->skb->data) {
 805                 err_hdr = (struct sctp_errhdr *)(chunk->skb->data);
 806
 807                 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
 808                                                      GFP_ATOMIC);
 809                 if (!ev)
 810                         return;
 811
 812                 sctp_ulpq_tail_event(&asoc->ulpq, ev);
 813
 814                 switch (err_hdr->cause) {
 815                 case SCTP_ERROR_UNKNOWN_CHUNK:
 816                 {
 817                         sctp_chunkhdr_t *unk_chunk_hdr;
 818
 819                         unk_chunk_hdr = (sctp_chunkhdr_t *)err_hdr->variable;
 820                         switch (unk_chunk_hdr->type) {
 821                         /* ADDIP 4.1 A9) If the peer responds to an ASCONF with
 822                          * an ERROR chunk reporting that it did not recognized
 823                          * the ASCONF chunk type, the sender of the ASCONF MUST
 824                          * NOT send any further ASCONF chunks and MUST stop its
 825                          * T-4 timer.
 826                          */
 827                         case SCTP_CID_ASCONF:
 828                                 if (asoc->peer.asconf_capable == 0)
 829                                         break;
 830
 831                                 asoc->peer.asconf_capable = 0;
 832                                 sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
 833                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
 834                                 break;
 835                         default:
 836                                 break;
 837                         }
 838                         break;
 839                 }
 840                 default:
 841                         break;
 842                 }
 843         }
 844 }
 845
 846 /* Process variable FWDTSN chunk information. */
 847 static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq,
 848                                     struct sctp_chunk *chunk)
 849 {
 850         struct sctp_fwdtsn_skip *skip;
 851         /* Walk through all the skipped SSNs */
 852         sctp_walk_fwdtsn(skip, chunk) {
 853                 sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
 854         }
 855
 856         return;
 857 }
 858
 859 /* Helper function to remove the association non-primary peer
 860  * transports.
 861  */
 862 static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
 863 {
 864         struct sctp_transport *t;
 865         struct list_head *pos;
 866         struct list_head *temp;
 867
 868         list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
 869                 t = list_entry(pos, struct sctp_transport, transports);
 870                 if (!sctp_cmp_addr_exact(&t->ipaddr,
 871                                          &asoc->peer.primary_addr)) {
 872                         sctp_assoc_del_peer(asoc, &t->ipaddr);
 873                 }
 874         }
 875
 876         return;
 877 }
 878
 879 /* Helper function to set sk_err on a 1-1 style socket. */
 880 static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
 881 {
 882         struct sock *sk = asoc->base.sk;
 883
 884         if (!sctp_style(sk, UDP))
 885                 sk->sk_err = error;
 886 }
 887
 888 /* Helper function to generate an association change event */
 889 static void sctp_cmd_assoc_change(sctp_cmd_seq_t *commands,
 890                                  struct sctp_association *asoc,
 891                                  u8 state)
 892 {
 893         struct sctp_ulpevent *ev;
 894
 895         ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0,
 896                                             asoc->c.sinit_num_ostreams,
 897                                             asoc->c.sinit_max_instreams,
 898                                             NULL, GFP_ATOMIC);
 899         if (ev)
 900                 sctp_ulpq_tail_event(&asoc->ulpq, ev);
 901 }
 902
 903 /* Helper function to generate an adaptation indication event */
 904 static void sctp_cmd_adaptation_ind(sctp_cmd_seq_t *commands,
 905                                     struct sctp_association *asoc)
 906 {
 907         struct sctp_ulpevent *ev;
 908
 909         ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
 910
 911         if (ev)
 912                 sctp_ulpq_tail_event(&asoc->ulpq, ev);
 913 }
 914
 915
 916 static void sctp_cmd_t1_timer_update(struct sctp_association *asoc,
 917                                     sctp_event_timeout_t timer,
 918                                     char *name)
 919 {
 920         struct sctp_transport *t;
 921
 922         t = asoc->init_last_sent_to;
 923         asoc->init_err_counter++;
 924
 925         if (t->init_sent_count > (asoc->init_cycle + 1)) {
 926                 asoc->timeouts[timer] *= 2;
 927                 if (asoc->timeouts[timer] > asoc->max_init_timeo) {
 928                         asoc->timeouts[timer] = asoc->max_init_timeo;
 929                 }
 930                 asoc->init_cycle++;
 931                 SCTP_DEBUG_PRINTK(
 932                         "T1 %s Timeout adjustment"
 933                         " init_err_counter: %d"
 934                         " cycle: %d"
 935                         " timeout: %ld\n",
 936                         name,
 937                         asoc->init_err_counter,
 938                         asoc->init_cycle,
 939                         asoc->timeouts[timer]);
 940         }
 941
 942 }
 943
 944 /* Send the whole message, chunk by chunk, to the outqueue.
 945  * This way the whole message is queued up and bundling if
 946  * encouraged for small fragments.
 947  */
 948 static int sctp_cmd_send_msg(struct sctp_association *asoc,
 949                                 struct sctp_datamsg *msg)
 950 {
 951         struct sctp_chunk *chunk;
 952         int error = 0;
 953
 954         list_for_each_entry(chunk, &msg->chunks, frag_list) {
 955                 error = sctp_outq_tail(&asoc->outqueue, chunk);
 956                 if (error)
 957                         break;
 958         }
 959
 960         return error;
 961 }
 962
 963
 964
 965 /* These three macros allow us to pull the debugging code out of the
 966  * main flow of sctp_do_sm() to keep attention focused on the real
 967  * functionality there.
 968  */
 969 #define DEBUG_PRE \
 970         SCTP_DEBUG_PRINTK("sctp_do_sm prefn: " \
 971                           "ep %p, %s, %s, asoc %p[%s], %s\n", \
 972                           ep, sctp_evttype_tbl[event_type], \
 973                           (*debug_fn)(subtype), asoc, \
 974                           sctp_state_tbl[state], state_fn->name)
 975
 976 #define DEBUG_POST \
 977         SCTP_DEBUG_PRINTK("sctp_do_sm postfn: " \
 978                           "asoc %p, status: %s\n", \
 979                           asoc, sctp_status_tbl[status])
 980
 981 #define DEBUG_POST_SFX \
 982         SCTP_DEBUG_PRINTK("sctp_do_sm post sfx: error %d, asoc %p[%s]\n", \
 983                           error, asoc, \
 984                           sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
 985                           sctp_assoc2id(asoc)))?asoc->state:SCTP_STATE_CLOSED])
 986
 987 /*
 988  * This is the master state machine processing function.
 989  *
 990  * If you want to understand all of lksctp, this is a
 991  * good place to start.
 992  */
 993 int sctp_do_sm(sctp_event_t event_type, sctp_subtype_t subtype,
 994                sctp_state_t state,
 995                struct sctp_endpoint *ep,
 996                struct sctp_association *asoc,
 997                void *event_arg,
 998                gfp_t gfp)
 999 {
1000         sctp_cmd_seq_t commands;
1001         const sctp_sm_table_entry_t *state_fn;
1002         sctp_disposition_t status;
1003         int error = 0;
1004         typedef const char *(printfn_t)(sctp_subtype_t);
1005
1006         static printfn_t *table[] = {
1007                 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
1008         };
1009         printfn_t *debug_fn  __attribute__ ((unused)) = table[event_type];
1010
1011         /* Look up the state function, run it, and then process the
1012          * side effects.  These three steps are the heart of lksctp.
1013          */
1014         state_fn = sctp_sm_lookup_event(event_type, state, subtype);
1015
1016         sctp_init_cmd_seq(&commands);
1017
1018         DEBUG_PRE;
1019         status = (*state_fn->fn)(ep, asoc, subtype, event_arg, &commands);
1020         DEBUG_POST;
1021
1022         error = sctp_side_effects(event_type, subtype, state,
1023                                   ep, asoc, event_arg, status,
1024                                   &commands, gfp);
1025         DEBUG_POST_SFX;
1026
1027         return error;
1028 }
1029
1030 #undef DEBUG_PRE
1031 #undef DEBUG_POST
1032
1033 /*****************************************************************
1034  * This the master state function side effect processing function.
1035  *****************************************************************/
1036 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
1037                              sctp_state_t state,
1038                              struct sctp_endpoint *ep,
1039                              struct sctp_association *asoc,
1040                              void *event_arg,
1041                              sctp_disposition_t status,
1042                              sctp_cmd_seq_t *commands,
1043                              gfp_t gfp)
1044 {
1045         int error;
1046
1047         /* FIXME - Most of the dispositions left today would be categorized
1048          * as "exceptional" dispositions.  For those dispositions, it
1049          * may not be proper to run through any of the commands at all.
1050          * For example, the command interpreter might be run only with
1051          * disposition SCTP_DISPOSITION_CONSUME.
1052          */
1053         if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
1054                                                ep, asoc,
1055                                                event_arg, status,
1056                                                commands, gfp)))
1057                 goto bail;
1058
1059         switch (status) {
1060         case SCTP_DISPOSITION_DISCARD:
1061                 SCTP_DEBUG_PRINTK("Ignored sctp protocol event - state %d, "
1062                                   "event_type %d, event_id %d\n",
1063                                   state, event_type, subtype.chunk);
1064                 break;
1065
1066         case SCTP_DISPOSITION_NOMEM:
1067                 /* We ran out of memory, so we need to discard this
1068                  * packet.
1069                  */
1070                 /* BUG--we should now recover some memory, probably by
1071                  * reneging...
1072                  */
1073                 error = -ENOMEM;
1074                 break;
1075
1076         case SCTP_DISPOSITION_DELETE_TCB:
1077                 /* This should now be a command. */
1078                 break;
1079
1080         case SCTP_DISPOSITION_CONSUME:
1081         case SCTP_DISPOSITION_ABORT:
1082                 /*
1083                  * We should no longer have much work to do here as the
1084                  * real work has been done as explicit commands above.
1085                  */
1086                 break;
1087
1088         case SCTP_DISPOSITION_VIOLATION:
1089                 if (net_ratelimit())
1090                         printk(KERN_ERR "sctp protocol violation state %d "
1091                                "chunkid %d\n", state, subtype.chunk);
1092                 break;
1093
1094         case SCTP_DISPOSITION_NOT_IMPL:
1095                 printk(KERN_WARNING "sctp unimplemented feature in state %d, "
1096                        "event_type %d, event_id %d\n",
1097                        state, event_type, subtype.chunk);
1098                 break;
1099
1100         case SCTP_DISPOSITION_BUG:
1101                 printk(KERN_ERR "sctp bug in state %d, "
1102                        "event_type %d, event_id %d\n",
1103                        state, event_type, subtype.chunk);
1104                 BUG();
1105                 break;
1106
1107         default:
1108                 printk(KERN_ERR "sctp impossible disposition %d "
1109                        "in state %d, event_type %d, event_id %d\n",
1110                        status, state, event_type, subtype.chunk);
1111                 BUG();
1112                 break;
1113         }
1114
1115 bail:
1116         return error;
1117 }
1118
1119 /********************************************************************
1120  * 2nd Level Abstractions
1121  ********************************************************************/
1122
1123 /* This is the side-effect interpreter.  */
1124 static int sctp_cmd_interpreter(sctp_event_t event_type,
1125                                 sctp_subtype_t subtype,
1126                                 sctp_state_t state,
1127                                 struct sctp_endpoint *ep,
1128                                 struct sctp_association *asoc,
1129                                 void *event_arg,
1130                                 sctp_disposition_t status,
1131                                 sctp_cmd_seq_t *commands,
1132                                 gfp_t gfp)
1133 {
1134         int error = 0;
1135         int force;
1136         sctp_cmd_t *cmd;
1137         struct sctp_chunk *new_obj;
1138         struct sctp_chunk *chunk = NULL;
1139         struct sctp_packet *packet;
1140         struct timer_list *timer;
1141         unsigned long timeout;
1142         struct sctp_transport *t;
1143         struct sctp_sackhdr sackh;
1144         int local_cork = 0;
1145
1146         if (SCTP_EVENT_T_TIMEOUT != event_type)
1147                 chunk = (struct sctp_chunk *) event_arg;
1148
1149         /* Note:  This whole file is a huge candidate for rework.
1150          * For example, each command could either have its own handler, so
1151          * the loop would look like:
1152          *     while (cmds)
1153          *         cmd->handle(x, y, z)
1154          * --jgrimm
1155          */
1156         while (NULL != (cmd = sctp_next_cmd(commands))) {
1157                 switch (cmd->verb) {
1158                 case SCTP_CMD_NOP:
1159                         /* Do nothing. */
1160                         break;
1161
1162                 case SCTP_CMD_NEW_ASOC:
1163                         /* Register a new association.  */
1164                         if (local_cork) {
1165                                 sctp_outq_uncork(&asoc->outqueue);
1166                                 local_cork = 0;
1167                         }
1168                         asoc = cmd->obj.ptr;
1169                         /* Register with the endpoint.  */
1170                         sctp_endpoint_add_asoc(ep, asoc);
1171                         sctp_hash_established(asoc);
1172                         break;
1173
1174                 case SCTP_CMD_UPDATE_ASSOC:
1175                        sctp_assoc_update(asoc, cmd->obj.ptr);
1176                        break;
1177
1178                 case SCTP_CMD_PURGE_OUTQUEUE:
1179                        sctp_outq_teardown(&asoc->outqueue);
1180                        break;
1181
1182                 case SCTP_CMD_DELETE_TCB:
1183                         if (local_cork) {
1184                                 sctp_outq_uncork(&asoc->outqueue);
1185                                 local_cork = 0;
1186                         }
1187                         /* Delete the current association.  */
1188                         sctp_cmd_delete_tcb(commands, asoc);
1189                         asoc = NULL;
1190                         break;
1191
1192                 case SCTP_CMD_NEW_STATE:
1193                         /* Enter a new state.  */
1194                         sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1195                         break;
1196
1197                 case SCTP_CMD_REPORT_TSN:
1198                         /* Record the arrival of a TSN.  */
1199                         error = sctp_tsnmap_mark(&asoc->peer.tsn_map,
1200                                                  cmd->obj.u32);
1201                         break;
1202
1203                 case SCTP_CMD_REPORT_FWDTSN:
1204                         /* Move the Cumulattive TSN Ack ahead. */
1205                         sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32);
1206
1207                         /* purge the fragmentation queue */
1208                         sctp_ulpq_reasm_flushtsn(&asoc->ulpq, cmd->obj.u32);
1209
1210                         /* Abort any in progress partial delivery. */
1211                         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
1212                         break;
1213
1214                 case SCTP_CMD_PROCESS_FWDTSN:
1215                         sctp_cmd_process_fwdtsn(&asoc->ulpq, cmd->obj.ptr);
1216                         break;
1217
1218                 case SCTP_CMD_GEN_SACK:
1219                         /* Generate a Selective ACK.
1220                          * The argument tells us whether to just count
1221                          * the packet and MAYBE generate a SACK, or
1222                          * force a SACK out.
1223                          */
1224                         force = cmd->obj.i32;
1225                         error = sctp_gen_sack(asoc, force, commands);
1226                         break;
1227
1228                 case SCTP_CMD_PROCESS_SACK:
1229                         /* Process an inbound SACK.  */
1230                         error = sctp_cmd_process_sack(commands, asoc,
1231                                                       cmd->obj.ptr);
1232                         break;
1233
1234                 case SCTP_CMD_GEN_INIT_ACK:
1235                         /* Generate an INIT ACK chunk.  */
1236                         new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1237                                                      0);
1238                         if (!new_obj)
1239                                 goto nomem;
1240
1241                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1242                                         SCTP_CHUNK(new_obj));
1243                         break;
1244
1245                 case SCTP_CMD_PEER_INIT:
1246                         /* Process a unified INIT from the peer.
1247                          * Note: Only used during INIT-ACK processing.  If
1248                          * there is an error just return to the outter
1249                          * layer which will bail.
1250                          */
1251                         error = sctp_cmd_process_init(commands, asoc, chunk,
1252                                                       cmd->obj.ptr, gfp);
1253                         break;
1254
1255                 case SCTP_CMD_GEN_COOKIE_ECHO:
1256                         /* Generate a COOKIE ECHO chunk.  */
1257                         new_obj = sctp_make_cookie_echo(asoc, chunk);
1258                         if (!new_obj) {
1259                                 if (cmd->obj.ptr)
1260                                         sctp_chunk_free(cmd->obj.ptr);
1261                                 goto nomem;
1262                         }
1263                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1264                                         SCTP_CHUNK(new_obj));
1265
1266                         /* If there is an ERROR chunk to be sent along with
1267                          * the COOKIE_ECHO, send it, too.
1268                          */
1269                         if (cmd->obj.ptr)
1270                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1271                                                 SCTP_CHUNK(cmd->obj.ptr));
1272
1273                         if (new_obj->transport) {
1274                                 new_obj->transport->init_sent_count++;
1275                                 asoc->init_last_sent_to = new_obj->transport;
1276                         }
1277
1278                         /* FIXME - Eventually come up with a cleaner way to
1279                          * enabling COOKIE-ECHO + DATA bundling during
1280                          * multihoming stale cookie scenarios, the following
1281                          * command plays with asoc->peer.retran_path to
1282                          * avoid the problem of sending the COOKIE-ECHO and
1283                          * DATA in different paths, which could result
1284                          * in the association being ABORTed if the DATA chunk
1285                          * is processed first by the server.  Checking the
1286                          * init error counter simply causes this command
1287                          * to be executed only during failed attempts of
1288                          * association establishment.
1289                          */
1290                         if ((asoc->peer.retran_path !=
1291                              asoc->peer.primary_path) &&
1292                             (asoc->init_err_counter > 0)) {
1293                                 sctp_add_cmd_sf(commands,
1294                                                 SCTP_CMD_FORCE_PRIM_RETRAN,
1295                                                 SCTP_NULL());
1296                         }
1297
1298                         break;
1299
1300                 case SCTP_CMD_GEN_SHUTDOWN:
1301                         /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1302                          * Reset error counts.
1303                          */
1304                         asoc->overall_error_count = 0;
1305
1306                         /* Generate a SHUTDOWN chunk.  */
1307                         new_obj = sctp_make_shutdown(asoc, chunk);
1308                         if (!new_obj)
1309                                 goto nomem;
1310                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1311                                         SCTP_CHUNK(new_obj));
1312                         break;
1313
1314                 case SCTP_CMD_CHUNK_ULP:
1315                         /* Send a chunk to the sockets layer.  */
1316                         SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1317                                           "chunk_up:", cmd->obj.ptr,
1318                                           "ulpq:", &asoc->ulpq);
1319                         sctp_ulpq_tail_data(&asoc->ulpq, cmd->obj.ptr,
1320                                             GFP_ATOMIC);
1321                         break;
1322
1323                 case SCTP_CMD_EVENT_ULP:
1324                         /* Send a notification to the sockets layer.  */
1325                         SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1326                                           "event_up:",cmd->obj.ptr,
1327                                           "ulpq:",&asoc->ulpq);
1328                         sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ptr);
1329                         break;
1330
1331                 case SCTP_CMD_REPLY:
1332                         /* If an caller has not already corked, do cork. */
1333                         if (!asoc->outqueue.cork) {
1334                                 sctp_outq_cork(&asoc->outqueue);
1335                                 local_cork = 1;
1336                         }
1337                         /* Send a chunk to our peer.  */
1338                         error = sctp_outq_tail(&asoc->outqueue, cmd->obj.ptr);
1339                         break;
1340
1341                 case SCTP_CMD_SEND_PKT:
1342                         /* Send a full packet to our peer.  */
1343                         packet = cmd->obj.ptr;
1344                         sctp_packet_transmit(packet);
1345                         sctp_ootb_pkt_free(packet);
1346                         break;
1347
1348                 case SCTP_CMD_T1_RETRAN:
1349                         /* Mark a transport for retransmission.  */
1350                         sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1351                                         SCTP_RTXR_T1_RTX);
1352                         break;
1353
1354                 case SCTP_CMD_RETRAN:
1355                         /* Mark a transport for retransmission.  */
1356                         sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1357                                         SCTP_RTXR_T3_RTX);
1358                         break;
1359
1360                 case SCTP_CMD_TRANSMIT:
1361                         /* Kick start transmission. */
1362                         error = sctp_outq_uncork(&asoc->outqueue);
1363                         local_cork = 0;
1364                         break;
1365
1366                 case SCTP_CMD_ECN_CE:
1367                         /* Do delayed CE processing.   */
1368                         sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1369                         break;
1370
1371                 case SCTP_CMD_ECN_ECNE:
1372                         /* Do delayed ECNE processing. */
1373                         new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1374                                                         chunk);
1375                         if (new_obj)
1376                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1377                                                 SCTP_CHUNK(new_obj));
1378                         break;
1379
1380                 case SCTP_CMD_ECN_CWR:
1381                         /* Do delayed CWR processing.  */
1382                         sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1383                         break;
1384
1385                 case SCTP_CMD_SETUP_T2:
1386                         sctp_cmd_setup_t2(commands, asoc, cmd->obj.ptr);
1387                         break;
1388
1389                 case SCTP_CMD_TIMER_START:
1390                         timer = &asoc->timers[cmd->obj.to];
1391                         timeout = asoc->timeouts[cmd->obj.to];
1392                         BUG_ON(!timeout);
1393
1394                         timer->expires = jiffies + timeout;
1395                         sctp_association_hold(asoc);
1396                         add_timer(timer);
1397                         break;
1398
1399                 case SCTP_CMD_TIMER_RESTART:
1400                         timer = &asoc->timers[cmd->obj.to];
1401                         timeout = asoc->timeouts[cmd->obj.to];
1402                         if (!mod_timer(timer, jiffies + timeout))
1403                                 sctp_association_hold(asoc);
1404                         break;
1405
1406                 case SCTP_CMD_TIMER_STOP:
1407                         timer = &asoc->timers[cmd->obj.to];
1408                         if (timer_pending(timer) && del_timer(timer))
1409                                 sctp_association_put(asoc);
1410                         break;
1411
1412                 case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1413                         chunk = cmd->obj.ptr;
1414                         t = sctp_assoc_choose_alter_transport(asoc,
1415                                                 asoc->init_last_sent_to);
1416                         asoc->init_last_sent_to = t;
1417                         chunk->transport = t;
1418                         t->init_sent_count++;
1419                         /* Set the new transport as primary */
1420                         sctp_assoc_set_primary(asoc, t);
1421                         break;
1422
1423                 case SCTP_CMD_INIT_RESTART:
1424                         /* Do the needed accounting and updates
1425                          * associated with restarting an initialization
1426                          * timer. Only multiply the timeout by two if
1427                          * all transports have been tried at the current
1428                          * timeout.
1429                          */
1430                         sctp_cmd_t1_timer_update(asoc,
1431                                                 SCTP_EVENT_TIMEOUT_T1_INIT,
1432                                                 "INIT");
1433
1434                         sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1435                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1436                         break;
1437
1438                 case SCTP_CMD_COOKIEECHO_RESTART:
1439                         /* Do the needed accounting and updates
1440                          * associated with restarting an initialization
1441                          * timer. Only multiply the timeout by two if
1442                          * all transports have been tried at the current
1443                          * timeout.
1444                          */
1445                         sctp_cmd_t1_timer_update(asoc,
1446                                                 SCTP_EVENT_TIMEOUT_T1_COOKIE,
1447                                                 "COOKIE");
1448
1449                         /* If we've sent any data bundled with
1450                          * COOKIE-ECHO we need to resend.
1451                          */
1452                         list_for_each_entry(t, &asoc->peer.transport_addr_list,
1453                                         transports) {
1454                                 sctp_retransmit_mark(&asoc->outqueue, t,
1455                                             SCTP_RTXR_T1_RTX);
1456                         }
1457
1458                         sctp_add_cmd_sf(commands,
1459                                         SCTP_CMD_TIMER_RESTART,
1460                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1461                         break;
1462
1463                 case SCTP_CMD_INIT_FAILED:
1464                         sctp_cmd_init_failed(commands, asoc, cmd->obj.err);
1465                         break;
1466
1467                 case SCTP_CMD_ASSOC_FAILED:
1468                         sctp_cmd_assoc_failed(commands, asoc, event_type,
1469                                               subtype, chunk, cmd->obj.err);
1470                         break;
1471
1472                 case SCTP_CMD_INIT_COUNTER_INC:
1473                         asoc->init_err_counter++;
1474                         break;
1475
1476                 case SCTP_CMD_INIT_COUNTER_RESET:
1477                         asoc->init_err_counter = 0;
1478                         asoc->init_cycle = 0;
1479                         list_for_each_entry(t, &asoc->peer.transport_addr_list,
1480                                             transports) {
1481                                 t->init_sent_count = 0;
1482                         }
1483                         break;
1484
1485                 case SCTP_CMD_REPORT_DUP:
1486                         sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1487                                              cmd->obj.u32);
1488                         break;
1489
1490                 case SCTP_CMD_REPORT_BAD_TAG:
1491                         SCTP_DEBUG_PRINTK("vtag mismatch!\n");
1492                         break;
1493
1494                 case SCTP_CMD_STRIKE:
1495                         /* Mark one strike against a transport.  */
1496                         sctp_do_8_2_transport_strike(asoc, cmd->obj.transport,
1497                                                     0);
1498                         break;
1499
1500                 case SCTP_CMD_TRANSPORT_IDLE:
1501                         t = cmd->obj.transport;
1502                         sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
1503                         break;
1504
1505                 case SCTP_CMD_TRANSPORT_HB_SENT:
1506                         t = cmd->obj.transport;
1507                         sctp_do_8_2_transport_strike(asoc, t, 1);
1508                         t->hb_sent = 1;
1509                         break;
1510
1511                 case SCTP_CMD_TRANSPORT_ON:
1512                         t = cmd->obj.transport;
1513                         sctp_cmd_transport_on(commands, asoc, t, chunk);
1514                         break;
1515
1516                 case SCTP_CMD_HB_TIMERS_START:
1517                         sctp_cmd_hb_timers_start(commands, asoc);
1518                         break;
1519
1520                 case SCTP_CMD_HB_TIMER_UPDATE:
1521                         t = cmd->obj.transport;
1522                         sctp_cmd_hb_timer_update(commands, t);
1523                         break;
1524
1525                 case SCTP_CMD_HB_TIMERS_STOP:
1526                         sctp_cmd_hb_timers_stop(commands, asoc);
1527                         break;
1528
1529                 case SCTP_CMD_REPORT_ERROR:
1530                         error = cmd->obj.error;
1531                         break;
1532
1533                 case SCTP_CMD_PROCESS_CTSN:
1534                         /* Dummy up a SACK for processing. */
1535                         sackh.cum_tsn_ack = cmd->obj.be32;
1536                         sackh.a_rwnd = asoc->peer.rwnd +
1537                                         asoc->outqueue.outstanding_bytes;
1538                         sackh.num_gap_ack_blocks = 0;
1539                         sackh.num_dup_tsns = 0;
1540                         sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1541                                         SCTP_SACKH(&sackh));
1542                         break;
1543
1544                 case SCTP_CMD_DISCARD_PACKET:
1545                         /* We need to discard the whole packet.
1546                          * Uncork the queue since there might be
1547                          * responses pending
1548                          */
1549                         chunk->pdiscard = 1;
1550                         if (asoc) {
1551                                 sctp_outq_uncork(&asoc->outqueue);
1552                                 local_cork = 0;
1553                         }
1554                         break;
1555
1556                 case SCTP_CMD_RTO_PENDING:
1557                         t = cmd->obj.transport;
1558                         t->rto_pending = 1;
1559                         break;
1560
1561                 case SCTP_CMD_PART_DELIVER:
1562                         sctp_ulpq_partial_delivery(&asoc->ulpq, cmd->obj.ptr,
1563                                                    GFP_ATOMIC);
1564                         break;
1565
1566                 case SCTP_CMD_RENEGE:
1567                         sctp_ulpq_renege(&asoc->ulpq, cmd->obj.ptr,
1568                                          GFP_ATOMIC);
1569                         break;
1570
1571                 case SCTP_CMD_SETUP_T4:
1572                         sctp_cmd_setup_t4(commands, asoc, cmd->obj.ptr);
1573                         break;
1574
1575                 case SCTP_CMD_PROCESS_OPERR:
1576                         sctp_cmd_process_operr(commands, asoc, chunk);
1577                         break;
1578                 case SCTP_CMD_CLEAR_INIT_TAG:
1579                         asoc->peer.i.init_tag = 0;
1580                         break;
1581                 case SCTP_CMD_DEL_NON_PRIMARY:
1582                         sctp_cmd_del_non_primary(asoc);
1583                         break;
1584                 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1585                         sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1586                         break;
1587                 case SCTP_CMD_FORCE_PRIM_RETRAN:
1588                         t = asoc->peer.retran_path;
1589                         asoc->peer.retran_path = asoc->peer.primary_path;
1590                         error = sctp_outq_uncork(&asoc->outqueue);
1591                         local_cork = 0;
1592                         asoc->peer.retran_path = t;
1593                         break;
1594                 case SCTP_CMD_SET_SK_ERR:
1595                         sctp_cmd_set_sk_err(asoc, cmd->obj.error);
1596                         break;
1597                 case SCTP_CMD_ASSOC_CHANGE:
1598                         sctp_cmd_assoc_change(commands, asoc,
1599                                               cmd->obj.u8);
1600                         break;
1601                 case SCTP_CMD_ADAPTATION_IND:
1602                         sctp_cmd_adaptation_ind(commands, asoc);
1603                         break;
1604
1605                 case SCTP_CMD_ASSOC_SHKEY:
1606                         error = sctp_auth_asoc_init_active_key(asoc,
1607                                                 GFP_ATOMIC);
1608                         break;
1609                 case SCTP_CMD_UPDATE_INITTAG:
1610                         asoc->peer.i.init_tag = cmd->obj.u32;
1611                         break;
1612                 case SCTP_CMD_SEND_MSG:
1613                         if (!asoc->outqueue.cork) {
1614                                 sctp_outq_cork(&asoc->outqueue);
1615                                 local_cork = 1;
1616                         }
1617                         error = sctp_cmd_send_msg(asoc, cmd->obj.msg);
1618                         break;
1619                 default:
1620                         printk(KERN_WARNING "Impossible command: %u, %p\n",
1621                                cmd->verb, cmd->obj.ptr);
1622                         break;
1623                 }
1624
1625                 if (error)
1626                         break;
1627         }
1628
1629 out:
1630         /* If this is in response to a received chunk, wait until
1631          * we are done with the packet to open the queue so that we don't
1632          * send multiple packets in response to a single request.
1633          */
1634         if (asoc && SCTP_EVENT_T_CHUNK == event_type && chunk) {
1635                 if (chunk->end_of_packet || chunk->singleton)
1636                         error = sctp_outq_uncork(&asoc->outqueue);
1637         } else if (local_cork)
1638                 error = sctp_outq_uncork(&asoc->outqueue);
1639         return error;
1640 nomem:
1641         error = -ENOMEM;
1642         goto out;
1643 }
1644