Pileus Git - ~andy/linux/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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  51
  52 #include <linux/skbuff.h>
  53 #include <linux/types.h>
  54 #include <linux/socket.h>
  55 #include <linux/ip.h>
  56 #include <linux/gfp.h>
  57 #include <net/sock.h>
  58 #include <net/sctp/sctp.h>
  59 #include <net/sctp/sm.h>
  60
  61 static int sctp_cmd_interpreter(sctp_event_t event_type,
  62                                 sctp_subtype_t subtype,
  63                                 sctp_state_t state,
  64                                 struct sctp_endpoint *ep,
  65                                 struct sctp_association *asoc,
  66                                 void *event_arg,
  67                                 sctp_disposition_t status,
  68                                 sctp_cmd_seq_t *commands,
  69                                 gfp_t gfp);
  70 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
  71                              sctp_state_t state,
  72                              struct sctp_endpoint *ep,
  73                              struct sctp_association *asoc,
  74                              void *event_arg,
  75                              sctp_disposition_t status,
  76                              sctp_cmd_seq_t *commands,
  77                              gfp_t gfp);
  78
  79 static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
  80                                      struct sctp_transport *t);
  81 /********************************************************************
  82  * Helper functions
  83  ********************************************************************/
  84
  85 /* A helper function for delayed processing of INET ECN CE bit. */
  86 static void sctp_do_ecn_ce_work(struct sctp_association *asoc,
  87                                 __u32 lowest_tsn)
  88 {
  89         /* Save the TSN away for comparison when we receive CWR */
  90
  91         asoc->last_ecne_tsn = lowest_tsn;
  92         asoc->need_ecne = 1;
  93 }
  94
  95 /* Helper function for delayed processing of SCTP ECNE chunk.  */
  96 /* RFC 2960 Appendix A
  97  *
  98  * RFC 2481 details a specific bit for a sender to send in
  99  * the header of its next outbound TCP segment to indicate to
 100  * its peer that it has reduced its congestion window.  This
 101  * is termed the CWR bit.  For SCTP the same indication is made
 102  * by including the CWR chunk.  This chunk contains one data
 103  * element, i.e. the TSN number that was sent in the ECNE chunk.
 104  * This element represents the lowest TSN number in the datagram
 105  * that was originally marked with the CE bit.
 106  */
 107 static struct sctp_chunk *sctp_do_ecn_ecne_work(struct sctp_association *asoc,
 108                                            __u32 lowest_tsn,
 109                                            struct sctp_chunk *chunk)
 110 {
 111         struct sctp_chunk *repl;
 112
 113         /* Our previously transmitted packet ran into some congestion
 114          * so we should take action by reducing cwnd and ssthresh
 115          * and then ACK our peer that we we've done so by
 116          * sending a CWR.
 117          */
 118
 119         /* First, try to determine if we want to actually lower
 120          * our cwnd variables.  Only lower them if the ECNE looks more
 121          * recent than the last response.
 122          */
 123         if (TSN_lt(asoc->last_cwr_tsn, lowest_tsn)) {
 124                 struct sctp_transport *transport;
 125
 126                 /* Find which transport's congestion variables
 127                  * need to be adjusted.
 128                  */
 129                 transport = sctp_assoc_lookup_tsn(asoc, lowest_tsn);
 130
 131                 /* Update the congestion variables. */
 132                 if (transport)
 133                         sctp_transport_lower_cwnd(transport,
 134                                                   SCTP_LOWER_CWND_ECNE);
 135                 asoc->last_cwr_tsn = lowest_tsn;
 136         }
 137
 138         /* Always try to quiet the other end.  In case of lost CWR,
 139          * resend last_cwr_tsn.
 140          */
 141         repl = sctp_make_cwr(asoc, asoc->last_cwr_tsn, chunk);
 142
 143         /* If we run out of memory, it will look like a lost CWR.  We'll
 144          * get back in sync eventually.
 145          */
 146         return repl;
 147 }
 148
 149 /* Helper function to do delayed processing of ECN CWR chunk.  */
 150 static void sctp_do_ecn_cwr_work(struct sctp_association *asoc,
 151                                  __u32 lowest_tsn)
 152 {
 153         /* Turn off ECNE getting auto-prepended to every outgoing
 154          * packet
 155          */
 156         asoc->need_ecne = 0;
 157 }
 158
 159 /* Generate SACK if necessary.  We call this at the end of a packet.  */
 160 static int sctp_gen_sack(struct sctp_association *asoc, int force,
 161                          sctp_cmd_seq_t *commands)
 162 {
 163         __u32 ctsn, max_tsn_seen;
 164         struct sctp_chunk *sack;
 165         struct sctp_transport *trans = asoc->peer.last_data_from;
 166         int error = 0;
 167
 168         if (force ||
 169             (!trans && (asoc->param_flags & SPP_SACKDELAY_DISABLE)) ||
 170             (trans && (trans->param_flags & SPP_SACKDELAY_DISABLE)))
 171                 asoc->peer.sack_needed = 1;
 172
 173         ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
 174         max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
 175
 176         /* From 12.2 Parameters necessary per association (i.e. the TCB):
 177          *
 178          * Ack State : This flag indicates if the next received packet
 179          *           : is to be responded to with a SACK. ...
 180          *           : When DATA chunks are out of order, SACK's
 181          *           : are not delayed (see Section 6).
 182          *
 183          * [This is actually not mentioned in Section 6, but we
 184          * implement it here anyway. --piggy]
 185          */
 186         if (max_tsn_seen != ctsn)
 187                 asoc->peer.sack_needed = 1;
 188
 189         /* From 6.2  Acknowledgement on Reception of DATA Chunks:
 190          *
 191          * Section 4.2 of [RFC2581] SHOULD be followed. Specifically,
 192          * an acknowledgement SHOULD be generated for at least every
 193          * second packet (not every second DATA chunk) received, and
 194          * SHOULD be generated within 200 ms of the arrival of any
 195          * unacknowledged DATA chunk. ...
 196          */
 197         if (!asoc->peer.sack_needed) {
 198                 asoc->peer.sack_cnt++;
 199
 200                 /* Set the SACK delay timeout based on the
 201                  * SACK delay for the last transport
 202                  * data was received from, or the default
 203                  * for the association.
 204                  */
 205                 if (trans) {
 206                         /* We will need a SACK for the next packet.  */
 207                         if (asoc->peer.sack_cnt >= trans->sackfreq - 1)
 208                                 asoc->peer.sack_needed = 1;
 209
 210                         asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
 211                                 trans->sackdelay;
 212                 } else {
 213                         /* We will need a SACK for the next packet.  */
 214                         if (asoc->peer.sack_cnt >= asoc->sackfreq - 1)
 215                                 asoc->peer.sack_needed = 1;
 216
 217                         asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
 218                                 asoc->sackdelay;
 219                 }
 220
 221                 /* Restart the SACK timer. */
 222                 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
 223                                 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
 224         } else {
 225                 asoc->a_rwnd = asoc->rwnd;
 226                 sack = sctp_make_sack(asoc);
 227                 if (!sack)
 228                         goto nomem;
 229
 230                 asoc->peer.sack_needed = 0;
 231                 asoc->peer.sack_cnt = 0;
 232
 233                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(sack));
 234
 235                 /* Stop the SACK timer.  */
 236                 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
 237                                 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
 238         }
 239
 240         return error;
 241 nomem:
 242         error = -ENOMEM;
 243         return error;
 244 }
 245
 246 /* When the T3-RTX timer expires, it calls this function to create the
 247  * relevant state machine event.
 248  */
 249 void sctp_generate_t3_rtx_event(unsigned long peer)
 250 {
 251         int error;
 252         struct sctp_transport *transport = (struct sctp_transport *) peer;
 253         struct sctp_association *asoc = transport->asoc;
 254         struct net *net = sock_net(asoc->base.sk);
 255
 256         /* Check whether a task is in the sock.  */
 257
 258         sctp_bh_lock_sock(asoc->base.sk);
 259         if (sock_owned_by_user(asoc->base.sk)) {
 260                 pr_debug("%s: sock is busy\n", __func__);
 261
 262                 /* Try again later.  */
 263                 if (!mod_timer(&transport->T3_rtx_timer, jiffies + (HZ/20)))
 264                         sctp_transport_hold(transport);
 265                 goto out_unlock;
 266         }
 267
 268         /* Is this transport really dead and just waiting around for
 269          * the timer to let go of the reference?
 270          */
 271         if (transport->dead)
 272                 goto out_unlock;
 273
 274         /* Run through the state machine.  */
 275         error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
 276                            SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX),
 277                            asoc->state,
 278                            asoc->ep, asoc,
 279                            transport, GFP_ATOMIC);
 280
 281         if (error)
 282                 asoc->base.sk->sk_err = -error;
 283
 284 out_unlock:
 285         sctp_bh_unlock_sock(asoc->base.sk);
 286         sctp_transport_put(transport);
 287 }
 288
 289 /* This is a sa interface for producing timeout events.  It works
 290  * for timeouts which use the association as their parameter.
 291  */
 292 static void sctp_generate_timeout_event(struct sctp_association *asoc,
 293                                         sctp_event_timeout_t timeout_type)
 294 {
 295         struct net *net = sock_net(asoc->base.sk);
 296         int error = 0;
 297
 298         sctp_bh_lock_sock(asoc->base.sk);
 299         if (sock_owned_by_user(asoc->base.sk)) {
 300                 pr_debug("%s: sock is busy: timer %d\n", __func__,
 301                          timeout_type);
 302
 303                 /* Try again later.  */
 304                 if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20)))
 305                         sctp_association_hold(asoc);
 306                 goto out_unlock;
 307         }
 308
 309         /* Is this association really dead and just waiting around for
 310          * the timer to let go of the reference?
 311          */
 312         if (asoc->base.dead)
 313                 goto out_unlock;
 314
 315         /* Run through the state machine.  */
 316         error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
 317                            SCTP_ST_TIMEOUT(timeout_type),
 318                            asoc->state, asoc->ep, asoc,
 319                            (void *)timeout_type, GFP_ATOMIC);
 320
 321         if (error)
 322                 asoc->base.sk->sk_err = -error;
 323
 324 out_unlock:
 325         sctp_bh_unlock_sock(asoc->base.sk);
 326         sctp_association_put(asoc);
 327 }
 328
 329 static void sctp_generate_t1_cookie_event(unsigned long data)
 330 {
 331         struct sctp_association *asoc = (struct sctp_association *) data;
 332         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
 333 }
 334
 335 static void sctp_generate_t1_init_event(unsigned long data)
 336 {
 337         struct sctp_association *asoc = (struct sctp_association *) data;
 338         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
 339 }
 340
 341 static void sctp_generate_t2_shutdown_event(unsigned long data)
 342 {
 343         struct sctp_association *asoc = (struct sctp_association *) data;
 344         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
 345 }
 346
 347 static void sctp_generate_t4_rto_event(unsigned long data)
 348 {
 349         struct sctp_association *asoc = (struct sctp_association *) data;
 350         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
 351 }
 352
 353 static void sctp_generate_t5_shutdown_guard_event(unsigned long data)
 354 {
 355         struct sctp_association *asoc = (struct sctp_association *)data;
 356         sctp_generate_timeout_event(asoc,
 357                                     SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);
 358
 359 } /* sctp_generate_t5_shutdown_guard_event() */
 360
 361 static void sctp_generate_autoclose_event(unsigned long data)
 362 {
 363         struct sctp_association *asoc = (struct sctp_association *) data;
 364         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE);
 365 }
 366
 367 /* Generate a heart beat event.  If the sock is busy, reschedule.   Make
 368  * sure that the transport is still valid.
 369  */
 370 void sctp_generate_heartbeat_event(unsigned long data)
 371 {
 372         int error = 0;
 373         struct sctp_transport *transport = (struct sctp_transport *) data;
 374         struct sctp_association *asoc = transport->asoc;
 375         struct net *net = sock_net(asoc->base.sk);
 376
 377         sctp_bh_lock_sock(asoc->base.sk);
 378         if (sock_owned_by_user(asoc->base.sk)) {
 379                 pr_debug("%s: sock is busy\n", __func__);
 380
 381                 /* Try again later.  */
 382                 if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20)))
 383                         sctp_transport_hold(transport);
 384                 goto out_unlock;
 385         }
 386
 387         /* Is this structure just waiting around for us to actually
 388          * get destroyed?
 389          */
 390         if (transport->dead)
 391                 goto out_unlock;
 392
 393         error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
 394                            SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
 395                            asoc->state, asoc->ep, asoc,
 396                            transport, GFP_ATOMIC);
 397
 398          if (error)
 399                  asoc->base.sk->sk_err = -error;
 400
 401 out_unlock:
 402         sctp_bh_unlock_sock(asoc->base.sk);
 403         sctp_transport_put(transport);
 404 }
 405
 406 /* Handle the timeout of the ICMP protocol unreachable timer.  Trigger
 407  * the correct state machine transition that will close the association.
 408  */
 409 void sctp_generate_proto_unreach_event(unsigned long data)
 410 {
 411         struct sctp_transport *transport = (struct sctp_transport *) data;
 412         struct sctp_association *asoc = transport->asoc;
 413         struct net *net = sock_net(asoc->base.sk);
 414
 415         sctp_bh_lock_sock(asoc->base.sk);
 416         if (sock_owned_by_user(asoc->base.sk)) {
 417                 pr_debug("%s: sock is busy\n", __func__);
 418
 419                 /* Try again later.  */
 420                 if (!mod_timer(&transport->proto_unreach_timer,
 421                                 jiffies + (HZ/20)))
 422                         sctp_association_hold(asoc);
 423                 goto out_unlock;
 424         }
 425
 426         /* Is this structure just waiting around for us to actually
 427          * get destroyed?
 428          */
 429         if (asoc->base.dead)
 430                 goto out_unlock;
 431
 432         sctp_do_sm(net, SCTP_EVENT_T_OTHER,
 433                    SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH),
 434                    asoc->state, asoc->ep, asoc, transport, GFP_ATOMIC);
 435
 436 out_unlock:
 437         sctp_bh_unlock_sock(asoc->base.sk);
 438         sctp_association_put(asoc);
 439 }
 440
 441
 442 /* Inject a SACK Timeout event into the state machine.  */
 443 static void sctp_generate_sack_event(unsigned long data)
 444 {
 445         struct sctp_association *asoc = (struct sctp_association *) data;
 446         sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
 447 }
 448
 449 sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
 450         NULL,
 451         sctp_generate_t1_cookie_event,
 452         sctp_generate_t1_init_event,
 453         sctp_generate_t2_shutdown_event,
 454         NULL,
 455         sctp_generate_t4_rto_event,
 456         sctp_generate_t5_shutdown_guard_event,
 457         NULL,
 458         sctp_generate_sack_event,
 459         sctp_generate_autoclose_event,
 460 };
 461
 462
 463 /* RFC 2960 8.2 Path Failure Detection
 464  *
 465  * When its peer endpoint is multi-homed, an endpoint should keep a
 466  * error counter for each of the destination transport addresses of the
 467  * peer endpoint.
 468  *
 469  * Each time the T3-rtx timer expires on any address, or when a
 470  * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
 471  * the error counter of that destination address will be incremented.
 472  * When the value in the error counter exceeds the protocol parameter
 473  * 'Path.Max.Retrans' of that destination address, the endpoint should
 474  * mark the destination transport address as inactive, and a
 475  * notification SHOULD be sent to the upper layer.
 476  *
 477  */
 478 static void sctp_do_8_2_transport_strike(sctp_cmd_seq_t *commands,
 479                                          struct sctp_association *asoc,
 480                                          struct sctp_transport *transport,
 481                                          int is_hb)
 482 {
 483         /* The check for association's overall error counter exceeding the
 484          * threshold is done in the state function.
 485          */
 486         /* We are here due to a timer expiration.  If the timer was
 487          * not a HEARTBEAT, then normal error tracking is done.
 488          * If the timer was a heartbeat, we only increment error counts
 489          * when we already have an outstanding HEARTBEAT that has not
 490          * been acknowledged.
 491          * Additionally, some tranport states inhibit error increments.
 492          */
 493         if (!is_hb) {
 494                 asoc->overall_error_count++;
 495                 if (transport->state != SCTP_INACTIVE)
 496                         transport->error_count++;
 497          } else if (transport->hb_sent) {
 498                 if (transport->state != SCTP_UNCONFIRMED)
 499                         asoc->overall_error_count++;
 500                 if (transport->state != SCTP_INACTIVE)
 501                         transport->error_count++;
 502         }
 503
 504         /* If the transport error count is greater than the pf_retrans
 505          * threshold, and less than pathmaxrtx, then mark this transport
 506          * as Partially Failed, ee SCTP Quick Failover Draft, secon 5.1,
 507          * point 1
 508          */
 509         if ((transport->state != SCTP_PF) &&
 510            (asoc->pf_retrans < transport->pathmaxrxt) &&
 511            (transport->error_count > asoc->pf_retrans)) {
 512
 513                 sctp_assoc_control_transport(asoc, transport,
 514                                              SCTP_TRANSPORT_PF,
 515                                              0);
 516
 517                 /* Update the hb timer to resend a heartbeat every rto */
 518                 sctp_cmd_hb_timer_update(commands, transport);
 519         }
 520
 521         if (transport->state != SCTP_INACTIVE &&
 522             (transport->error_count > transport->pathmaxrxt)) {
 523                 pr_debug("%s: association:%p transport addr:%pISpc failed\n",
 524                          __func__, asoc, &transport->ipaddr.sa);
 525
 526                 sctp_assoc_control_transport(asoc, transport,
 527                                              SCTP_TRANSPORT_DOWN,
 528                                              SCTP_FAILED_THRESHOLD);
 529         }
 530
 531         /* E2) For the destination address for which the timer
 532          * expires, set RTO <- RTO * 2 ("back off the timer").  The
 533          * maximum value discussed in rule C7 above (RTO.max) may be
 534          * used to provide an upper bound to this doubling operation.
 535          *
 536          * Special Case:  the first HB doesn't trigger exponential backoff.
 537          * The first unacknowledged HB triggers it.  We do this with a flag
 538          * that indicates that we have an outstanding HB.
 539          */
 540         if (!is_hb || transport->hb_sent) {
 541                 transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
 542                 sctp_max_rto(asoc, transport);
 543         }
 544 }
 545
 546 /* Worker routine to handle INIT command failure.  */
 547 static void sctp_cmd_init_failed(sctp_cmd_seq_t *commands,
 548                                  struct sctp_association *asoc,
 549                                  unsigned int error)
 550 {
 551         struct sctp_ulpevent *event;
 552
 553         event = sctp_ulpevent_make_assoc_change(asoc,0, SCTP_CANT_STR_ASSOC,
 554                                                 (__u16)error, 0, 0, NULL,
 555                                                 GFP_ATOMIC);
 556
 557         if (event)
 558                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 559                                 SCTP_ULPEVENT(event));
 560
 561         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 562                         SCTP_STATE(SCTP_STATE_CLOSED));
 563
 564         /* SEND_FAILED sent later when cleaning up the association. */
 565         asoc->outqueue.error = error;
 566         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 567 }
 568
 569 /* Worker routine to handle SCTP_CMD_ASSOC_FAILED.  */
 570 static void sctp_cmd_assoc_failed(sctp_cmd_seq_t *commands,
 571                                   struct sctp_association *asoc,
 572                                   sctp_event_t event_type,
 573                                   sctp_subtype_t subtype,
 574                                   struct sctp_chunk *chunk,
 575                                   unsigned int error)
 576 {
 577         struct sctp_ulpevent *event;
 578         struct sctp_chunk *abort;
 579         /* Cancel any partial delivery in progress. */
 580         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
 581
 582         if (event_type == SCTP_EVENT_T_CHUNK && subtype.chunk == SCTP_CID_ABORT)
 583                 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
 584                                                 (__u16)error, 0, 0, chunk,
 585                                                 GFP_ATOMIC);
 586         else
 587                 event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
 588                                                 (__u16)error, 0, 0, NULL,
 589                                                 GFP_ATOMIC);
 590         if (event)
 591                 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 592                                 SCTP_ULPEVENT(event));
 593
 594         if (asoc->overall_error_count >= asoc->max_retrans) {
 595                 abort = sctp_make_violation_max_retrans(asoc, chunk);
 596                 if (abort)
 597                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
 598                                         SCTP_CHUNK(abort));
 599         }
 600
 601         sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 602                         SCTP_STATE(SCTP_STATE_CLOSED));
 603
 604         /* SEND_FAILED sent later when cleaning up the association. */
 605         asoc->outqueue.error = error;
 606         sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 607 }
 608
 609 /* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
 610  * inside the cookie.  In reality, this is only used for INIT-ACK processing
 611  * since all other cases use "temporary" associations and can do all
 612  * their work in statefuns directly.
 613  */
 614 static int sctp_cmd_process_init(sctp_cmd_seq_t *commands,
 615                                  struct sctp_association *asoc,
 616                                  struct sctp_chunk *chunk,
 617                                  sctp_init_chunk_t *peer_init,
 618                                  gfp_t gfp)
 619 {
 620         int error;
 621
 622         /* We only process the init as a sideeffect in a single
 623          * case.   This is when we process the INIT-ACK.   If we
 624          * fail during INIT processing (due to malloc problems),
 625          * just return the error and stop processing the stack.
 626          */
 627         if (!sctp_process_init(asoc, chunk, sctp_source(chunk), peer_init, gfp))
 628                 error = -ENOMEM;
 629         else
 630                 error = 0;
 631
 632         return error;
 633 }
 634
 635 /* Helper function to break out starting up of heartbeat timers.  */
 636 static void sctp_cmd_hb_timers_start(sctp_cmd_seq_t *cmds,
 637                                      struct sctp_association *asoc)
 638 {
 639         struct sctp_transport *t;
 640
 641         /* Start a heartbeat timer for each transport on the association.
 642          * hold a reference on the transport to make sure none of
 643          * the needed data structures go away.
 644          */
 645         list_for_each_entry(t, &asoc->peer.transport_addr_list, transports) {
 646
 647                 if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 648                         sctp_transport_hold(t);
 649         }
 650 }
 651
 652 static void sctp_cmd_hb_timers_stop(sctp_cmd_seq_t *cmds,
 653                                     struct sctp_association *asoc)
 654 {
 655         struct sctp_transport *t;
 656
 657         /* Stop all heartbeat timers. */
 658
 659         list_for_each_entry(t, &asoc->peer.transport_addr_list,
 660                         transports) {
 661                 if (del_timer(&t->hb_timer))
 662                         sctp_transport_put(t);
 663         }
 664 }
 665
 666 /* Helper function to stop any pending T3-RTX timers */
 667 static void sctp_cmd_t3_rtx_timers_stop(sctp_cmd_seq_t *cmds,
 668                                         struct sctp_association *asoc)
 669 {
 670         struct sctp_transport *t;
 671
 672         list_for_each_entry(t, &asoc->peer.transport_addr_list,
 673                         transports) {
 674                 if (del_timer(&t->T3_rtx_timer))
 675                         sctp_transport_put(t);
 676         }
 677 }
 678
 679
 680 /* Helper function to update the heartbeat timer. */
 681 static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
 682                                      struct sctp_transport *t)
 683 {
 684         /* Update the heartbeat timer.  */
 685         if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 686                 sctp_transport_hold(t);
 687 }
 688
 689 /* Helper function to handle the reception of an HEARTBEAT ACK.  */
 690 static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds,
 691                                   struct sctp_association *asoc,
 692                                   struct sctp_transport *t,
 693                                   struct sctp_chunk *chunk)
 694 {
 695         sctp_sender_hb_info_t *hbinfo;
 696         int was_unconfirmed = 0;
 697
 698         /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
 699          * HEARTBEAT should clear the error counter of the destination
 700          * transport address to which the HEARTBEAT was sent.
 701          */
 702         t->error_count = 0;
 703
 704         /*
 705          * Although RFC4960 specifies that the overall error count must
 706          * be cleared when a HEARTBEAT ACK is received, we make an
 707          * exception while in SHUTDOWN PENDING. If the peer keeps its
 708          * window shut forever, we may never be able to transmit our
 709          * outstanding data and rely on the retransmission limit be reached
 710          * to shutdown the association.
 711          */
 712         if (t->asoc->state != SCTP_STATE_SHUTDOWN_PENDING)
 713                 t->asoc->overall_error_count = 0;
 714
 715         /* Clear the hb_sent flag to signal that we had a good
 716          * acknowledgement.
 717          */
 718         t->hb_sent = 0;
 719
 720         /* Mark the destination transport address as active if it is not so
 721          * marked.
 722          */
 723         if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED)) {
 724                 was_unconfirmed = 1;
 725                 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
 726                                              SCTP_HEARTBEAT_SUCCESS);
 727         }
 728
 729         if (t->state == SCTP_PF)
 730                 sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
 731                                              SCTP_HEARTBEAT_SUCCESS);
 732
 733         /* HB-ACK was received for a the proper HB.  Consider this
 734          * forward progress.
 735          */
 736         if (t->dst)
 737                 dst_confirm(t->dst);
 738
 739         /* The receiver of the HEARTBEAT ACK should also perform an
 740          * RTT measurement for that destination transport address
 741          * using the time value carried in the HEARTBEAT ACK chunk.
 742          * If the transport's rto_pending variable has been cleared,
 743          * it was most likely due to a retransmit.  However, we want
 744          * to re-enable it to properly update the rto.
 745          */
 746         if (t->rto_pending == 0)
 747                 t->rto_pending = 1;
 748
 749         hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
 750         sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
 751
 752         /* Update the heartbeat timer.  */
 753         if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 754                 sctp_transport_hold(t);
 755
 756         if (was_unconfirmed && asoc->peer.transport_count == 1)
 757                 sctp_transport_immediate_rtx(t);
 758 }
 759
 760
 761 /* Helper function to process the process SACK command.  */
 762 static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds,
 763                                  struct sctp_association *asoc,
 764                                  struct sctp_chunk *chunk)
 765 {
 766         int err = 0;
 767
 768         if (sctp_outq_sack(&asoc->outqueue, chunk)) {
 769                 struct net *net = sock_net(asoc->base.sk);
 770
 771                 /* There are no more TSNs awaiting SACK.  */
 772                 err = sctp_do_sm(net, SCTP_EVENT_T_OTHER,
 773                                  SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
 774                                  asoc->state, asoc->ep, asoc, NULL,
 775                                  GFP_ATOMIC);
 776         }
 777
 778         return err;
 779 }
 780
 781 /* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
 782  * the transport for a shutdown chunk.
 783  */
 784 static void sctp_cmd_setup_t2(sctp_cmd_seq_t *cmds,
 785                               struct sctp_association *asoc,
 786                               struct sctp_chunk *chunk)
 787 {
 788         struct sctp_transport *t;
 789
 790         if (chunk->transport)
 791                 t = chunk->transport;
 792         else {
 793                 t = sctp_assoc_choose_alter_transport(asoc,
 794                                               asoc->shutdown_last_sent_to);
 795                 chunk->transport = t;
 796         }
 797         asoc->shutdown_last_sent_to = t;
 798         asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
 799 }
 800
 801 /* Helper function to change the state of an association. */
 802 static void sctp_cmd_new_state(sctp_cmd_seq_t *cmds,
 803                                struct sctp_association *asoc,
 804                                sctp_state_t state)
 805 {
 806         struct sock *sk = asoc->base.sk;
 807
 808         asoc->state = state;
 809
 810         pr_debug("%s: asoc:%p[%s]\n", __func__, asoc, sctp_state_tbl[state]);
 811
 812         if (sctp_style(sk, TCP)) {
 813                 /* Change the sk->sk_state of a TCP-style socket that has
 814                  * successfully completed a connect() call.
 815                  */
 816                 if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
 817                         sk->sk_state = SCTP_SS_ESTABLISHED;
 818
 819                 /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
 820                 if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
 821                     sctp_sstate(sk, ESTABLISHED))
 822                         sk->sk_shutdown |= RCV_SHUTDOWN;
 823         }
 824
 825         if (sctp_state(asoc, COOKIE_WAIT)) {
 826                 /* Reset init timeouts since they may have been
 827                  * increased due to timer expirations.
 828                  */
 829                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
 830                                                 asoc->rto_initial;
 831                 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
 832                                                 asoc->rto_initial;
 833         }
 834
 835         if (sctp_state(asoc, ESTABLISHED) ||
 836             sctp_state(asoc, CLOSED) ||
 837             sctp_state(asoc, SHUTDOWN_RECEIVED)) {
 838                 /* Wake up any processes waiting in the asoc's wait queue in
 839                  * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
 840                  */
 841                 if (waitqueue_active(&asoc->wait))
 842                         wake_up_interruptible(&asoc->wait);
 843
 844                 /* Wake up any processes waiting in the sk's sleep queue of
 845                  * a TCP-style or UDP-style peeled-off socket in
 846                  * sctp_wait_for_accept() or sctp_wait_for_packet().
 847                  * For a UDP-style socket, the waiters are woken up by the
 848                  * notifications.
 849                  */
 850                 if (!sctp_style(sk, UDP))
 851                         sk->sk_state_change(sk);
 852         }
 853 }
 854
 855 /* Helper function to delete an association. */
 856 static void sctp_cmd_delete_tcb(sctp_cmd_seq_t *cmds,
 857                                 struct sctp_association *asoc)
 858 {
 859         struct sock *sk = asoc->base.sk;
 860
 861         /* If it is a non-temporary association belonging to a TCP-style
 862          * listening socket that is not closed, do not free it so that accept()
 863          * can pick it up later.
 864          */
 865         if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
 866             (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
 867                 return;
 868
 869         BUG_ON(asoc->peer.primary_path == NULL);
 870         sctp_unhash_established(asoc);
 871         sctp_association_free(asoc);
 872 }
 873
 874 /*
 875  * ADDIP Section 4.1 ASCONF Chunk Procedures
 876  * A4) Start a T-4 RTO timer, using the RTO value of the selected
 877  * destination address (we use active path instead of primary path just
 878  * because primary path may be inactive.
 879  */
 880 static void sctp_cmd_setup_t4(sctp_cmd_seq_t *cmds,
 881                                 struct sctp_association *asoc,
 882                                 struct sctp_chunk *chunk)
 883 {
 884         struct sctp_transport *t;
 885
 886         t = sctp_assoc_choose_alter_transport(asoc, chunk->transport);
 887         asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
 888         chunk->transport = t;
 889 }
 890
 891 /* Process an incoming Operation Error Chunk. */
 892 static void sctp_cmd_process_operr(sctp_cmd_seq_t *cmds,
 893                                    struct sctp_association *asoc,
 894                                    struct sctp_chunk *chunk)
 895 {
 896         struct sctp_errhdr *err_hdr;
 897         struct sctp_ulpevent *ev;
 898
 899         while (chunk->chunk_end > chunk->skb->data) {
 900                 err_hdr = (struct sctp_errhdr *)(chunk->skb->data);
 901
 902                 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
 903                                                      GFP_ATOMIC);
 904                 if (!ev)
 905                         return;
 906
 907                 sctp_ulpq_tail_event(&asoc->ulpq, ev);
 908
 909                 switch (err_hdr->cause) {
 910                 case SCTP_ERROR_UNKNOWN_CHUNK:
 911                 {
 912                         sctp_chunkhdr_t *unk_chunk_hdr;
 913
 914                         unk_chunk_hdr = (sctp_chunkhdr_t *)err_hdr->variable;
 915                         switch (unk_chunk_hdr->type) {
 916                         /* ADDIP 4.1 A9) If the peer responds to an ASCONF with
 917                          * an ERROR chunk reporting that it did not recognized
 918                          * the ASCONF chunk type, the sender of the ASCONF MUST
 919                          * NOT send any further ASCONF chunks and MUST stop its
 920                          * T-4 timer.
 921                          */
 922                         case SCTP_CID_ASCONF:
 923                                 if (asoc->peer.asconf_capable == 0)
 924                                         break;
 925
 926                                 asoc->peer.asconf_capable = 0;
 927                                 sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
 928                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
 929                                 break;
 930                         default:
 931                                 break;
 932                         }
 933                         break;
 934                 }
 935                 default:
 936                         break;
 937                 }
 938         }
 939 }
 940
 941 /* Process variable FWDTSN chunk information. */
 942 static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq,
 943                                     struct sctp_chunk *chunk)
 944 {
 945         struct sctp_fwdtsn_skip *skip;
 946         /* Walk through all the skipped SSNs */
 947         sctp_walk_fwdtsn(skip, chunk) {
 948                 sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
 949         }
 950 }
 951
 952 /* Helper function to remove the association non-primary peer
 953  * transports.
 954  */
 955 static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
 956 {
 957         struct sctp_transport *t;
 958         struct list_head *pos;
 959         struct list_head *temp;
 960
 961         list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
 962                 t = list_entry(pos, struct sctp_transport, transports);
 963                 if (!sctp_cmp_addr_exact(&t->ipaddr,
 964                                          &asoc->peer.primary_addr)) {
 965                         sctp_assoc_del_peer(asoc, &t->ipaddr);
 966                 }
 967         }
 968 }
 969
 970 /* Helper function to set sk_err on a 1-1 style socket. */
 971 static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
 972 {
 973         struct sock *sk = asoc->base.sk;
 974
 975         if (!sctp_style(sk, UDP))
 976                 sk->sk_err = error;
 977 }
 978
 979 /* Helper function to generate an association change event */
 980 static void sctp_cmd_assoc_change(sctp_cmd_seq_t *commands,
 981                                  struct sctp_association *asoc,
 982                                  u8 state)
 983 {
 984         struct sctp_ulpevent *ev;
 985
 986         ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0,
 987                                             asoc->c.sinit_num_ostreams,
 988                                             asoc->c.sinit_max_instreams,
 989                                             NULL, GFP_ATOMIC);
 990         if (ev)
 991                 sctp_ulpq_tail_event(&asoc->ulpq, ev);
 992 }
 993
 994 /* Helper function to generate an adaptation indication event */
 995 static void sctp_cmd_adaptation_ind(sctp_cmd_seq_t *commands,
 996                                     struct sctp_association *asoc)
 997 {
 998         struct sctp_ulpevent *ev;
 999
1000         ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
1001
1002         if (ev)
1003                 sctp_ulpq_tail_event(&asoc->ulpq, ev);
1004 }
1005
1006
1007 static void sctp_cmd_t1_timer_update(struct sctp_association *asoc,
1008                                     sctp_event_timeout_t timer,
1009                                     char *name)
1010 {
1011         struct sctp_transport *t;
1012
1013         t = asoc->init_last_sent_to;
1014         asoc->init_err_counter++;
1015
1016         if (t->init_sent_count > (asoc->init_cycle + 1)) {
1017                 asoc->timeouts[timer] *= 2;
1018                 if (asoc->timeouts[timer] > asoc->max_init_timeo) {
1019                         asoc->timeouts[timer] = asoc->max_init_timeo;
1020                 }
1021                 asoc->init_cycle++;
1022
1023                 pr_debug("%s: T1[%s] timeout adjustment init_err_counter:%d"
1024                          " cycle:%d timeout:%ld\n", __func__, name,
1025                          asoc->init_err_counter, asoc->init_cycle,
1026                          asoc->timeouts[timer]);
1027         }
1028
1029 }
1030
1031 /* Send the whole message, chunk by chunk, to the outqueue.
1032  * This way the whole message is queued up and bundling if
1033  * encouraged for small fragments.
1034  */
1035 static int sctp_cmd_send_msg(struct sctp_association *asoc,
1036                                 struct sctp_datamsg *msg)
1037 {
1038         struct sctp_chunk *chunk;
1039         int error = 0;
1040
1041         list_for_each_entry(chunk, &msg->chunks, frag_list) {
1042                 error = sctp_outq_tail(&asoc->outqueue, chunk);
1043                 if (error)
1044                         break;
1045         }
1046
1047         return error;
1048 }
1049
1050
1051 /* Sent the next ASCONF packet currently stored in the association.
1052  * This happens after the ASCONF_ACK was succeffully processed.
1053  */
1054 static void sctp_cmd_send_asconf(struct sctp_association *asoc)
1055 {
1056         struct net *net = sock_net(asoc->base.sk);
1057
1058         /* Send the next asconf chunk from the addip chunk
1059          * queue.
1060          */
1061         if (!list_empty(&asoc->addip_chunk_list)) {
1062                 struct list_head *entry = asoc->addip_chunk_list.next;
1063                 struct sctp_chunk *asconf = list_entry(entry,
1064                                                 struct sctp_chunk, list);
1065                 list_del_init(entry);
1066
1067                 /* Hold the chunk until an ASCONF_ACK is received. */
1068                 sctp_chunk_hold(asconf);
1069                 if (sctp_primitive_ASCONF(net, asoc, asconf))
1070                         sctp_chunk_free(asconf);
1071                 else
1072                         asoc->addip_last_asconf = asconf;
1073         }
1074 }
1075
1076
1077 /* These three macros allow us to pull the debugging code out of the
1078  * main flow of sctp_do_sm() to keep attention focused on the real
1079  * functionality there.
1080  */
1081 #define debug_pre_sfn() \
1082         pr_debug("%s[pre-fn]: ep:%p, %s, %s, asoc:%p[%s], %s\n", __func__, \
1083                  ep, sctp_evttype_tbl[event_type], (*debug_fn)(subtype),   \
1084                  asoc, sctp_state_tbl[state], state_fn->name)
1085
1086 #define debug_post_sfn() \
1087         pr_debug("%s[post-fn]: asoc:%p, status:%s\n", __func__, asoc, \
1088                  sctp_status_tbl[status])
1089
1090 #define debug_post_sfx() \
1091         pr_debug("%s[post-sfx]: error:%d, asoc:%p[%s]\n", __func__, error, \
1092                  asoc, sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
1093                  sctp_assoc2id(asoc))) ? asoc->state : SCTP_STATE_CLOSED])
1094
1095 /*
1096  * This is the master state machine processing function.
1097  *
1098  * If you want to understand all of lksctp, this is a
1099  * good place to start.
1100  */
1101 int sctp_do_sm(struct net *net, sctp_event_t event_type, sctp_subtype_t subtype,
1102                sctp_state_t state,
1103                struct sctp_endpoint *ep,
1104                struct sctp_association *asoc,
1105                void *event_arg,
1106                gfp_t gfp)
1107 {
1108         sctp_cmd_seq_t commands;
1109         const sctp_sm_table_entry_t *state_fn;
1110         sctp_disposition_t status;
1111         int error = 0;
1112         typedef const char *(printfn_t)(sctp_subtype_t);
1113         static printfn_t *table[] = {
1114                 NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
1115         };
1116         printfn_t *debug_fn  __attribute__ ((unused)) = table[event_type];
1117
1118         /* Look up the state function, run it, and then process the
1119          * side effects.  These three steps are the heart of lksctp.
1120          */
1121         state_fn = sctp_sm_lookup_event(net, event_type, state, subtype);
1122
1123         sctp_init_cmd_seq(&commands);
1124
1125         debug_pre_sfn();
1126         status = (*state_fn->fn)(net, ep, asoc, subtype, event_arg, &commands);
1127         debug_post_sfn();
1128
1129         error = sctp_side_effects(event_type, subtype, state,
1130                                   ep, asoc, event_arg, status,
1131                                   &commands, gfp);
1132         debug_post_sfx();
1133
1134         return error;
1135 }
1136
1137 /*****************************************************************
1138  * This the master state function side effect processing function.
1139  *****************************************************************/
1140 static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
1141                              sctp_state_t state,
1142                              struct sctp_endpoint *ep,
1143                              struct sctp_association *asoc,
1144                              void *event_arg,
1145                              sctp_disposition_t status,
1146                              sctp_cmd_seq_t *commands,
1147                              gfp_t gfp)
1148 {
1149         int error;
1150
1151         /* FIXME - Most of the dispositions left today would be categorized
1152          * as "exceptional" dispositions.  For those dispositions, it
1153          * may not be proper to run through any of the commands at all.
1154          * For example, the command interpreter might be run only with
1155          * disposition SCTP_DISPOSITION_CONSUME.
1156          */
1157         if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
1158                                                ep, asoc,
1159                                                event_arg, status,
1160                                                commands, gfp)))
1161                 goto bail;
1162
1163         switch (status) {
1164         case SCTP_DISPOSITION_DISCARD:
1165                 pr_debug("%s: ignored sctp protocol event - state:%d, "
1166                          "event_type:%d, event_id:%d\n", __func__, state,
1167                          event_type, subtype.chunk);
1168                 break;
1169
1170         case SCTP_DISPOSITION_NOMEM:
1171                 /* We ran out of memory, so we need to discard this
1172                  * packet.
1173                  */
1174                 /* BUG--we should now recover some memory, probably by
1175                  * reneging...
1176                  */
1177                 error = -ENOMEM;
1178                 break;
1179
1180         case SCTP_DISPOSITION_DELETE_TCB:
1181                 /* This should now be a command. */
1182                 break;
1183
1184         case SCTP_DISPOSITION_CONSUME:
1185         case SCTP_DISPOSITION_ABORT:
1186                 /*
1187                  * We should no longer have much work to do here as the
1188                  * real work has been done as explicit commands above.
1189                  */
1190                 break;
1191
1192         case SCTP_DISPOSITION_VIOLATION:
1193                 net_err_ratelimited("protocol violation state %d chunkid %d\n",
1194                                     state, subtype.chunk);
1195                 break;
1196
1197         case SCTP_DISPOSITION_NOT_IMPL:
1198                 pr_warn("unimplemented feature in state %d, event_type %d, event_id %d\n",
1199                         state, event_type, subtype.chunk);
1200                 break;
1201
1202         case SCTP_DISPOSITION_BUG:
1203                 pr_err("bug in state %d, event_type %d, event_id %d\n",
1204                        state, event_type, subtype.chunk);
1205                 BUG();
1206                 break;
1207
1208         default:
1209                 pr_err("impossible disposition %d in state %d, event_type %d, event_id %d\n",
1210                        status, state, event_type, subtype.chunk);
1211                 BUG();
1212                 break;
1213         }
1214
1215 bail:
1216         return error;
1217 }
1218
1219 /********************************************************************
1220  * 2nd Level Abstractions
1221  ********************************************************************/
1222
1223 /* This is the side-effect interpreter.  */
1224 static int sctp_cmd_interpreter(sctp_event_t event_type,
1225                                 sctp_subtype_t subtype,
1226                                 sctp_state_t state,
1227                                 struct sctp_endpoint *ep,
1228                                 struct sctp_association *asoc,
1229                                 void *event_arg,
1230                                 sctp_disposition_t status,
1231                                 sctp_cmd_seq_t *commands,
1232                                 gfp_t gfp)
1233 {
1234         int error = 0;
1235         int force;
1236         sctp_cmd_t *cmd;
1237         struct sctp_chunk *new_obj;
1238         struct sctp_chunk *chunk = NULL;
1239         struct sctp_packet *packet;
1240         struct timer_list *timer;
1241         unsigned long timeout;
1242         struct sctp_transport *t;
1243         struct sctp_sackhdr sackh;
1244         int local_cork = 0;
1245
1246         if (SCTP_EVENT_T_TIMEOUT != event_type)
1247                 chunk = event_arg;
1248
1249         /* Note:  This whole file is a huge candidate for rework.
1250          * For example, each command could either have its own handler, so
1251          * the loop would look like:
1252          *     while (cmds)
1253          *         cmd->handle(x, y, z)
1254          * --jgrimm
1255          */
1256         while (NULL != (cmd = sctp_next_cmd(commands))) {
1257                 switch (cmd->verb) {
1258                 case SCTP_CMD_NOP:
1259                         /* Do nothing. */
1260                         break;
1261
1262                 case SCTP_CMD_NEW_ASOC:
1263                         /* Register a new association.  */
1264                         if (local_cork) {
1265                                 sctp_outq_uncork(&asoc->outqueue);
1266                                 local_cork = 0;
1267                         }
1268
1269                         /* Register with the endpoint.  */
1270                         asoc = cmd->obj.asoc;
1271                         BUG_ON(asoc->peer.primary_path == NULL);
1272                         sctp_endpoint_add_asoc(ep, asoc);
1273                         sctp_hash_established(asoc);
1274                         break;
1275
1276                 case SCTP_CMD_UPDATE_ASSOC:
1277                        sctp_assoc_update(asoc, cmd->obj.asoc);
1278                        break;
1279
1280                 case SCTP_CMD_PURGE_OUTQUEUE:
1281                        sctp_outq_teardown(&asoc->outqueue);
1282                        break;
1283
1284                 case SCTP_CMD_DELETE_TCB:
1285                         if (local_cork) {
1286                                 sctp_outq_uncork(&asoc->outqueue);
1287                                 local_cork = 0;
1288                         }
1289                         /* Delete the current association.  */
1290                         sctp_cmd_delete_tcb(commands, asoc);
1291                         asoc = NULL;
1292                         break;
1293
1294                 case SCTP_CMD_NEW_STATE:
1295                         /* Enter a new state.  */
1296                         sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1297                         break;
1298
1299                 case SCTP_CMD_REPORT_TSN:
1300                         /* Record the arrival of a TSN.  */
1301                         error = sctp_tsnmap_mark(&asoc->peer.tsn_map,
1302                                                  cmd->obj.u32, NULL);
1303                         break;
1304
1305                 case SCTP_CMD_REPORT_FWDTSN:
1306                         /* Move the Cumulattive TSN Ack ahead. */
1307                         sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32);
1308
1309                         /* purge the fragmentation queue */
1310                         sctp_ulpq_reasm_flushtsn(&asoc->ulpq, cmd->obj.u32);
1311
1312                         /* Abort any in progress partial delivery. */
1313                         sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
1314                         break;
1315
1316                 case SCTP_CMD_PROCESS_FWDTSN:
1317                         sctp_cmd_process_fwdtsn(&asoc->ulpq, cmd->obj.chunk);
1318                         break;
1319
1320                 case SCTP_CMD_GEN_SACK:
1321                         /* Generate a Selective ACK.
1322                          * The argument tells us whether to just count
1323                          * the packet and MAYBE generate a SACK, or
1324                          * force a SACK out.
1325                          */
1326                         force = cmd->obj.i32;
1327                         error = sctp_gen_sack(asoc, force, commands);
1328                         break;
1329
1330                 case SCTP_CMD_PROCESS_SACK:
1331                         /* Process an inbound SACK.  */
1332                         error = sctp_cmd_process_sack(commands, asoc,
1333                                                       cmd->obj.chunk);
1334                         break;
1335
1336                 case SCTP_CMD_GEN_INIT_ACK:
1337                         /* Generate an INIT ACK chunk.  */
1338                         new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1339                                                      0);
1340                         if (!new_obj)
1341                                 goto nomem;
1342
1343                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1344                                         SCTP_CHUNK(new_obj));
1345                         break;
1346
1347                 case SCTP_CMD_PEER_INIT:
1348                         /* Process a unified INIT from the peer.
1349                          * Note: Only used during INIT-ACK processing.  If
1350                          * there is an error just return to the outter
1351                          * layer which will bail.
1352                          */
1353                         error = sctp_cmd_process_init(commands, asoc, chunk,
1354                                                       cmd->obj.init, gfp);
1355                         break;
1356
1357                 case SCTP_CMD_GEN_COOKIE_ECHO:
1358                         /* Generate a COOKIE ECHO chunk.  */
1359                         new_obj = sctp_make_cookie_echo(asoc, chunk);
1360                         if (!new_obj) {
1361                                 if (cmd->obj.chunk)
1362                                         sctp_chunk_free(cmd->obj.chunk);
1363                                 goto nomem;
1364                         }
1365                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1366                                         SCTP_CHUNK(new_obj));
1367
1368                         /* If there is an ERROR chunk to be sent along with
1369                          * the COOKIE_ECHO, send it, too.
1370                          */
1371                         if (cmd->obj.chunk)
1372                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1373                                                 SCTP_CHUNK(cmd->obj.chunk));
1374
1375                         if (new_obj->transport) {
1376                                 new_obj->transport->init_sent_count++;
1377                                 asoc->init_last_sent_to = new_obj->transport;
1378                         }
1379
1380                         /* FIXME - Eventually come up with a cleaner way to
1381                          * enabling COOKIE-ECHO + DATA bundling during
1382                          * multihoming stale cookie scenarios, the following
1383                          * command plays with asoc->peer.retran_path to
1384                          * avoid the problem of sending the COOKIE-ECHO and
1385                          * DATA in different paths, which could result
1386                          * in the association being ABORTed if the DATA chunk
1387                          * is processed first by the server.  Checking the
1388                          * init error counter simply causes this command
1389                          * to be executed only during failed attempts of
1390                          * association establishment.
1391                          */
1392                         if ((asoc->peer.retran_path !=
1393                              asoc->peer.primary_path) &&
1394                             (asoc->init_err_counter > 0)) {
1395                                 sctp_add_cmd_sf(commands,
1396                                                 SCTP_CMD_FORCE_PRIM_RETRAN,
1397                                                 SCTP_NULL());
1398                         }
1399
1400                         break;
1401
1402                 case SCTP_CMD_GEN_SHUTDOWN:
1403                         /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1404                          * Reset error counts.
1405                          */
1406                         asoc->overall_error_count = 0;
1407
1408                         /* Generate a SHUTDOWN chunk.  */
1409                         new_obj = sctp_make_shutdown(asoc, chunk);
1410                         if (!new_obj)
1411                                 goto nomem;
1412                         sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1413                                         SCTP_CHUNK(new_obj));
1414                         break;
1415
1416                 case SCTP_CMD_CHUNK_ULP:
1417                         /* Send a chunk to the sockets layer.  */
1418                         pr_debug("%s: sm_sideff: chunk_up:%p, ulpq:%p\n",
1419                                  __func__, cmd->obj.chunk, &asoc->ulpq);
1420
1421                         sctp_ulpq_tail_data(&asoc->ulpq, cmd->obj.chunk,
1422                                             GFP_ATOMIC);
1423                         break;
1424
1425                 case SCTP_CMD_EVENT_ULP:
1426                         /* Send a notification to the sockets layer.  */
1427                         pr_debug("%s: sm_sideff: event_up:%p, ulpq:%p\n",
1428                                  __func__, cmd->obj.ulpevent, &asoc->ulpq);
1429
1430                         sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ulpevent);
1431                         break;
1432
1433                 case SCTP_CMD_REPLY:
1434                         /* If an caller has not already corked, do cork. */
1435                         if (!asoc->outqueue.cork) {
1436                                 sctp_outq_cork(&asoc->outqueue);
1437                                 local_cork = 1;
1438                         }
1439                         /* Send a chunk to our peer.  */
1440                         error = sctp_outq_tail(&asoc->outqueue, cmd->obj.chunk);
1441                         break;
1442
1443                 case SCTP_CMD_SEND_PKT:
1444                         /* Send a full packet to our peer.  */
1445                         packet = cmd->obj.packet;
1446                         sctp_packet_transmit(packet);
1447                         sctp_ootb_pkt_free(packet);
1448                         break;
1449
1450                 case SCTP_CMD_T1_RETRAN:
1451                         /* Mark a transport for retransmission.  */
1452                         sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1453                                         SCTP_RTXR_T1_RTX);
1454                         break;
1455
1456                 case SCTP_CMD_RETRAN:
1457                         /* Mark a transport for retransmission.  */
1458                         sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1459                                         SCTP_RTXR_T3_RTX);
1460                         break;
1461
1462                 case SCTP_CMD_ECN_CE:
1463                         /* Do delayed CE processing.   */
1464                         sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1465                         break;
1466
1467                 case SCTP_CMD_ECN_ECNE:
1468                         /* Do delayed ECNE processing. */
1469                         new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1470                                                         chunk);
1471                         if (new_obj)
1472                                 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1473                                                 SCTP_CHUNK(new_obj));
1474                         break;
1475
1476                 case SCTP_CMD_ECN_CWR:
1477                         /* Do delayed CWR processing.  */
1478                         sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1479                         break;
1480
1481                 case SCTP_CMD_SETUP_T2:
1482                         sctp_cmd_setup_t2(commands, asoc, cmd->obj.chunk);
1483                         break;
1484
1485                 case SCTP_CMD_TIMER_START_ONCE:
1486                         timer = &asoc->timers[cmd->obj.to];
1487
1488                         if (timer_pending(timer))
1489                                 break;
1490                         /* fall through */
1491
1492                 case SCTP_CMD_TIMER_START:
1493                         timer = &asoc->timers[cmd->obj.to];
1494                         timeout = asoc->timeouts[cmd->obj.to];
1495                         BUG_ON(!timeout);
1496
1497                         timer->expires = jiffies + timeout;
1498                         sctp_association_hold(asoc);
1499                         add_timer(timer);
1500                         break;
1501
1502                 case SCTP_CMD_TIMER_RESTART:
1503                         timer = &asoc->timers[cmd->obj.to];
1504                         timeout = asoc->timeouts[cmd->obj.to];
1505                         if (!mod_timer(timer, jiffies + timeout))
1506                                 sctp_association_hold(asoc);
1507                         break;
1508
1509                 case SCTP_CMD_TIMER_STOP:
1510                         timer = &asoc->timers[cmd->obj.to];
1511                         if (del_timer(timer))
1512                                 sctp_association_put(asoc);
1513                         break;
1514
1515                 case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1516                         chunk = cmd->obj.chunk;
1517                         t = sctp_assoc_choose_alter_transport(asoc,
1518                                                 asoc->init_last_sent_to);
1519                         asoc->init_last_sent_to = t;
1520                         chunk->transport = t;
1521                         t->init_sent_count++;
1522                         /* Set the new transport as primary */
1523                         sctp_assoc_set_primary(asoc, t);
1524                         break;
1525
1526                 case SCTP_CMD_INIT_RESTART:
1527                         /* Do the needed accounting and updates
1528                          * associated with restarting an initialization
1529                          * timer. Only multiply the timeout by two if
1530                          * all transports have been tried at the current
1531                          * timeout.
1532                          */
1533                         sctp_cmd_t1_timer_update(asoc,
1534                                                 SCTP_EVENT_TIMEOUT_T1_INIT,
1535                                                 "INIT");
1536
1537                         sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1538                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1539                         break;
1540
1541                 case SCTP_CMD_COOKIEECHO_RESTART:
1542                         /* Do the needed accounting and updates
1543                          * associated with restarting an initialization
1544                          * timer. Only multiply the timeout by two if
1545                          * all transports have been tried at the current
1546                          * timeout.
1547                          */
1548                         sctp_cmd_t1_timer_update(asoc,
1549                                                 SCTP_EVENT_TIMEOUT_T1_COOKIE,
1550                                                 "COOKIE");
1551
1552                         /* If we've sent any data bundled with
1553                          * COOKIE-ECHO we need to resend.
1554                          */
1555                         list_for_each_entry(t, &asoc->peer.transport_addr_list,
1556                                         transports) {
1557                                 sctp_retransmit_mark(&asoc->outqueue, t,
1558                                             SCTP_RTXR_T1_RTX);
1559                         }
1560
1561                         sctp_add_cmd_sf(commands,
1562                                         SCTP_CMD_TIMER_RESTART,
1563                                         SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1564                         break;
1565
1566                 case SCTP_CMD_INIT_FAILED:
1567                         sctp_cmd_init_failed(commands, asoc, cmd->obj.err);
1568                         break;
1569
1570                 case SCTP_CMD_ASSOC_FAILED:
1571                         sctp_cmd_assoc_failed(commands, asoc, event_type,
1572                                               subtype, chunk, cmd->obj.err);
1573                         break;
1574
1575                 case SCTP_CMD_INIT_COUNTER_INC:
1576                         asoc->init_err_counter++;
1577                         break;
1578
1579                 case SCTP_CMD_INIT_COUNTER_RESET:
1580                         asoc->init_err_counter = 0;
1581                         asoc->init_cycle = 0;
1582                         list_for_each_entry(t, &asoc->peer.transport_addr_list,
1583                                             transports) {
1584                                 t->init_sent_count = 0;
1585                         }
1586                         break;
1587
1588                 case SCTP_CMD_REPORT_DUP:
1589                         sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1590                                              cmd->obj.u32);
1591                         break;
1592
1593                 case SCTP_CMD_REPORT_BAD_TAG:
1594                         pr_debug("%s: vtag mismatch!\n", __func__);
1595                         break;
1596
1597                 case SCTP_CMD_STRIKE:
1598                         /* Mark one strike against a transport.  */
1599                         sctp_do_8_2_transport_strike(commands, asoc,
1600                                                     cmd->obj.transport, 0);
1601                         break;
1602
1603                 case SCTP_CMD_TRANSPORT_IDLE:
1604                         t = cmd->obj.transport;
1605                         sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
1606                         break;
1607
1608                 case SCTP_CMD_TRANSPORT_HB_SENT:
1609                         t = cmd->obj.transport;
1610                         sctp_do_8_2_transport_strike(commands, asoc,
1611                                                      t, 1);
1612                         t->hb_sent = 1;
1613                         break;
1614
1615                 case SCTP_CMD_TRANSPORT_ON:
1616                         t = cmd->obj.transport;
1617                         sctp_cmd_transport_on(commands, asoc, t, chunk);
1618                         break;
1619
1620                 case SCTP_CMD_HB_TIMERS_START:
1621                         sctp_cmd_hb_timers_start(commands, asoc);
1622                         break;
1623
1624                 case SCTP_CMD_HB_TIMER_UPDATE:
1625                         t = cmd->obj.transport;
1626                         sctp_cmd_hb_timer_update(commands, t);
1627                         break;
1628
1629                 case SCTP_CMD_HB_TIMERS_STOP:
1630                         sctp_cmd_hb_timers_stop(commands, asoc);
1631                         break;
1632
1633                 case SCTP_CMD_REPORT_ERROR:
1634                         error = cmd->obj.error;
1635                         break;
1636
1637                 case SCTP_CMD_PROCESS_CTSN:
1638                         /* Dummy up a SACK for processing. */
1639                         sackh.cum_tsn_ack = cmd->obj.be32;
1640                         sackh.a_rwnd = asoc->peer.rwnd +
1641                                         asoc->outqueue.outstanding_bytes;
1642                         sackh.num_gap_ack_blocks = 0;
1643                         sackh.num_dup_tsns = 0;
1644                         chunk->subh.sack_hdr = &sackh;
1645                         sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1646                                         SCTP_CHUNK(chunk));
1647                         break;
1648
1649                 case SCTP_CMD_DISCARD_PACKET:
1650                         /* We need to discard the whole packet.
1651                          * Uncork the queue since there might be
1652                          * responses pending
1653                          */
1654                         chunk->pdiscard = 1;
1655                         if (asoc) {
1656                                 sctp_outq_uncork(&asoc->outqueue);
1657                                 local_cork = 0;
1658                         }
1659                         break;
1660
1661                 case SCTP_CMD_RTO_PENDING:
1662                         t = cmd->obj.transport;
1663                         t->rto_pending = 1;
1664                         break;
1665
1666                 case SCTP_CMD_PART_DELIVER:
1667                         sctp_ulpq_partial_delivery(&asoc->ulpq, GFP_ATOMIC);
1668                         break;
1669
1670                 case SCTP_CMD_RENEGE:
1671                         sctp_ulpq_renege(&asoc->ulpq, cmd->obj.chunk,
1672                                          GFP_ATOMIC);
1673                         break;
1674
1675                 case SCTP_CMD_SETUP_T4:
1676                         sctp_cmd_setup_t4(commands, asoc, cmd->obj.chunk);
1677                         break;
1678
1679                 case SCTP_CMD_PROCESS_OPERR:
1680                         sctp_cmd_process_operr(commands, asoc, chunk);
1681                         break;
1682                 case SCTP_CMD_CLEAR_INIT_TAG:
1683                         asoc->peer.i.init_tag = 0;
1684                         break;
1685                 case SCTP_CMD_DEL_NON_PRIMARY:
1686                         sctp_cmd_del_non_primary(asoc);
1687                         break;
1688                 case SCTP_CMD_T3_RTX_TIMERS_STOP:
1689                         sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1690                         break;
1691                 case SCTP_CMD_FORCE_PRIM_RETRAN:
1692                         t = asoc->peer.retran_path;
1693                         asoc->peer.retran_path = asoc->peer.primary_path;
1694                         error = sctp_outq_uncork(&asoc->outqueue);
1695                         local_cork = 0;
1696                         asoc->peer.retran_path = t;
1697                         break;
1698                 case SCTP_CMD_SET_SK_ERR:
1699                         sctp_cmd_set_sk_err(asoc, cmd->obj.error);
1700                         break;
1701                 case SCTP_CMD_ASSOC_CHANGE:
1702                         sctp_cmd_assoc_change(commands, asoc,
1703                                               cmd->obj.u8);
1704                         break;
1705                 case SCTP_CMD_ADAPTATION_IND:
1706                         sctp_cmd_adaptation_ind(commands, asoc);
1707                         break;
1708
1709                 case SCTP_CMD_ASSOC_SHKEY:
1710                         error = sctp_auth_asoc_init_active_key(asoc,
1711                                                 GFP_ATOMIC);
1712                         break;
1713                 case SCTP_CMD_UPDATE_INITTAG:
1714                         asoc->peer.i.init_tag = cmd->obj.u32;
1715                         break;
1716                 case SCTP_CMD_SEND_MSG:
1717                         if (!asoc->outqueue.cork) {
1718                                 sctp_outq_cork(&asoc->outqueue);
1719                                 local_cork = 1;
1720                         }
1721                         error = sctp_cmd_send_msg(asoc, cmd->obj.msg);
1722                         break;
1723                 case SCTP_CMD_SEND_NEXT_ASCONF:
1724                         sctp_cmd_send_asconf(asoc);
1725                         break;
1726                 case SCTP_CMD_PURGE_ASCONF_QUEUE:
1727                         sctp_asconf_queue_teardown(asoc);
1728                         break;
1729
1730                 case SCTP_CMD_SET_ASOC:
1731                         asoc = cmd->obj.asoc;
1732                         break;
1733
1734                 default:
1735                         pr_warn("Impossible command: %u\n",
1736                                 cmd->verb);
1737                         break;
1738                 }
1739
1740                 if (error)
1741                         break;
1742         }
1743
1744 out:
1745         /* If this is in response to a received chunk, wait until
1746          * we are done with the packet to open the queue so that we don't
1747          * send multiple packets in response to a single request.
1748          */
1749         if (asoc && SCTP_EVENT_T_CHUNK == event_type && chunk) {
1750                 if (chunk->end_of_packet || chunk->singleton)
1751                         error = sctp_outq_uncork(&asoc->outqueue);
1752         } else if (local_cork)
1753                 error = sctp_outq_uncork(&asoc->outqueue);
1754         return error;
1755 nomem:
1756         error = -ENOMEM;
1757         goto out;
1758 }
1759