linux/net/sctp/sm_sideeffect.c
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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
  58static 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);
  67static 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. */
  81static 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 */
 102static 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.  */
 145static 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.  */
 155static int sctp_gen_sack(struct sctp_association *asoc, int force,
 156                         sctp_cmd_seq_t *commands)
 157{
 158        __u32 ctsn, max_tsn_seen;
 159        struct sctp_chunk *sack;
 160        struct sctp_transport *trans = asoc->peer.last_data_from;
 161        int error = 0;
 162
 163        if (force ||
 164            (!trans && (asoc->param_flags & SPP_SACKDELAY_DISABLE)) ||
 165            (trans && (trans->param_flags & SPP_SACKDELAY_DISABLE)))
 166                asoc->peer.sack_needed = 1;
 167
 168        ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
 169        max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
 170
 171        /* From 12.2 Parameters necessary per association (i.e. the TCB):
 172         *
 173         * Ack State : This flag indicates if the next received packet
 174         *           : is to be responded to with a SACK. ...
 175         *           : When DATA chunks are out of order, SACK's
 176         *           : are not delayed (see Section 6).
 177         *
 178         * [This is actually not mentioned in Section 6, but we
 179         * implement it here anyway. --piggy]
 180         */
 181        if (max_tsn_seen != ctsn)
 182                asoc->peer.sack_needed = 1;
 183
 184        /* From 6.2  Acknowledgement on Reception of DATA Chunks:
 185         *
 186         * Section 4.2 of [RFC2581] SHOULD be followed. Specifically,
 187         * an acknowledgement SHOULD be generated for at least every
 188         * second packet (not every second DATA chunk) received, and
 189         * SHOULD be generated within 200 ms of the arrival of any
 190         * unacknowledged DATA chunk. ...
 191         */
 192        if (!asoc->peer.sack_needed) {
 193                asoc->peer.sack_cnt++;
 194
 195                /* Set the SACK delay timeout based on the
 196                 * SACK delay for the last transport
 197                 * data was received from, or the default
 198                 * for the association.
 199                 */
 200                if (trans) {
 201                        /* We will need a SACK for the next packet.  */
 202                        if (asoc->peer.sack_cnt >= trans->sackfreq - 1)
 203                                asoc->peer.sack_needed = 1;
 204
 205                        asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
 206                                trans->sackdelay;
 207                } else {
 208                        /* We will need a SACK for the next packet.  */
 209                        if (asoc->peer.sack_cnt >= asoc->sackfreq - 1)
 210                                asoc->peer.sack_needed = 1;
 211
 212                        asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
 213                                asoc->sackdelay;
 214                }
 215
 216                /* Restart the SACK timer. */
 217                sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
 218                                SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
 219        } else {
 220                if (asoc->a_rwnd > asoc->rwnd)
 221                        asoc->a_rwnd = asoc->rwnd;
 222                sack = sctp_make_sack(asoc);
 223                if (!sack)
 224                        goto nomem;
 225
 226                asoc->peer.sack_needed = 0;
 227                asoc->peer.sack_cnt = 0;
 228
 229                sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(sack));
 230
 231                /* Stop the SACK timer.  */
 232                sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
 233                                SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
 234        }
 235
 236        return error;
 237nomem:
 238        error = -ENOMEM;
 239        return error;
 240}
 241
 242/* When the T3-RTX timer expires, it calls this function to create the
 243 * relevant state machine event.
 244 */
 245void sctp_generate_t3_rtx_event(unsigned long peer)
 246{
 247        int error;
 248        struct sctp_transport *transport = (struct sctp_transport *) peer;
 249        struct sctp_association *asoc = transport->asoc;
 250
 251        /* Check whether a task is in the sock.  */
 252
 253        sctp_bh_lock_sock(asoc->base.sk);
 254        if (sock_owned_by_user(asoc->base.sk)) {
 255                SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __func__);
 256
 257                /* Try again later.  */
 258                if (!mod_timer(&transport->T3_rtx_timer, jiffies + (HZ/20)))
 259                        sctp_transport_hold(transport);
 260                goto out_unlock;
 261        }
 262
 263        /* Is this transport really dead and just waiting around for
 264         * the timer to let go of the reference?
 265         */
 266        if (transport->dead)
 267                goto out_unlock;
 268
 269        /* Run through the state machine.  */
 270        error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
 271                           SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX),
 272                           asoc->state,
 273                           asoc->ep, asoc,
 274                           transport, GFP_ATOMIC);
 275
 276        if (error)
 277                asoc->base.sk->sk_err = -error;
 278
 279out_unlock:
 280        sctp_bh_unlock_sock(asoc->base.sk);
 281        sctp_transport_put(transport);
 282}
 283
 284/* This is a sa interface for producing timeout events.  It works
 285 * for timeouts which use the association as their parameter.
 286 */
 287static void sctp_generate_timeout_event(struct sctp_association *asoc,
 288                                        sctp_event_timeout_t timeout_type)
 289{
 290        int error = 0;
 291
 292        sctp_bh_lock_sock(asoc->base.sk);
 293        if (sock_owned_by_user(asoc->base.sk)) {
 294                SCTP_DEBUG_PRINTK("%s:Sock is busy: timer %d\n",
 295                                  __func__,
 296                                  timeout_type);
 297
 298                /* Try again later.  */
 299                if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20)))
 300                        sctp_association_hold(asoc);
 301                goto out_unlock;
 302        }
 303
 304        /* Is this association really dead and just waiting around for
 305         * the timer to let go of the reference?
 306         */
 307        if (asoc->base.dead)
 308                goto out_unlock;
 309
 310        /* Run through the state machine.  */
 311        error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
 312                           SCTP_ST_TIMEOUT(timeout_type),
 313                           asoc->state, asoc->ep, asoc,
 314                           (void *)timeout_type, GFP_ATOMIC);
 315
 316        if (error)
 317                asoc->base.sk->sk_err = -error;
 318
 319out_unlock:
 320        sctp_bh_unlock_sock(asoc->base.sk);
 321        sctp_association_put(asoc);
 322}
 323
 324static void sctp_generate_t1_cookie_event(unsigned long data)
 325{
 326        struct sctp_association *asoc = (struct sctp_association *) data;
 327        sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
 328}
 329
 330static void sctp_generate_t1_init_event(unsigned long data)
 331{
 332        struct sctp_association *asoc = (struct sctp_association *) data;
 333        sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
 334}
 335
 336static void sctp_generate_t2_shutdown_event(unsigned long data)
 337{
 338        struct sctp_association *asoc = (struct sctp_association *) data;
 339        sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
 340}
 341
 342static void sctp_generate_t4_rto_event(unsigned long data)
 343{
 344        struct sctp_association *asoc = (struct sctp_association *) data;
 345        sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
 346}
 347
 348static void sctp_generate_t5_shutdown_guard_event(unsigned long data)
 349{
 350        struct sctp_association *asoc = (struct sctp_association *)data;
 351        sctp_generate_timeout_event(asoc,
 352                                    SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);
 353
 354} /* sctp_generate_t5_shutdown_guard_event() */
 355
 356static void sctp_generate_autoclose_event(unsigned long data)
 357{
 358        struct sctp_association *asoc = (struct sctp_association *) data;
 359        sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE);
 360}
 361
 362/* Generate a heart beat event.  If the sock is busy, reschedule.   Make
 363 * sure that the transport is still valid.
 364 */
 365void sctp_generate_heartbeat_event(unsigned long data)
 366{
 367        int error = 0;
 368        struct sctp_transport *transport = (struct sctp_transport *) data;
 369        struct sctp_association *asoc = transport->asoc;
 370
 371        sctp_bh_lock_sock(asoc->base.sk);
 372        if (sock_owned_by_user(asoc->base.sk)) {
 373                SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __func__);
 374
 375                /* Try again later.  */
 376                if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20)))
 377                        sctp_transport_hold(transport);
 378                goto out_unlock;
 379        }
 380
 381        /* Is this structure just waiting around for us to actually
 382         * get destroyed?
 383         */
 384        if (transport->dead)
 385                goto out_unlock;
 386
 387        error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
 388                           SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
 389                           asoc->state, asoc->ep, asoc,
 390                           transport, GFP_ATOMIC);
 391
 392         if (error)
 393                 asoc->base.sk->sk_err = -error;
 394
 395out_unlock:
 396        sctp_bh_unlock_sock(asoc->base.sk);
 397        sctp_transport_put(transport);
 398}
 399
 400/* Inject a SACK Timeout event into the state machine.  */
 401static void sctp_generate_sack_event(unsigned long data)
 402{
 403        struct sctp_association *asoc = (struct sctp_association *) data;
 404        sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
 405}
 406
 407sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
 408        NULL,
 409        sctp_generate_t1_cookie_event,
 410        sctp_generate_t1_init_event,
 411        sctp_generate_t2_shutdown_event,
 412        NULL,
 413        sctp_generate_t4_rto_event,
 414        sctp_generate_t5_shutdown_guard_event,
 415        NULL,
 416        sctp_generate_sack_event,
 417        sctp_generate_autoclose_event,
 418};
 419
 420
 421/* RFC 2960 8.2 Path Failure Detection
 422 *
 423 * When its peer endpoint is multi-homed, an endpoint should keep a
 424 * error counter for each of the destination transport addresses of the
 425 * peer endpoint.
 426 *
 427 * Each time the T3-rtx timer expires on any address, or when a
 428 * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
 429 * the error counter of that destination address will be incremented.
 430 * When the value in the error counter exceeds the protocol parameter
 431 * 'Path.Max.Retrans' of that destination address, the endpoint should
 432 * mark the destination transport address as inactive, and a
 433 * notification SHOULD be sent to the upper layer.
 434 *
 435 */
 436static void sctp_do_8_2_transport_strike(struct sctp_association *asoc,
 437                                         struct sctp_transport *transport,
 438                                         int is_hb)
 439{
 440        /* The check for association's overall error counter exceeding the
 441         * threshold is done in the state function.
 442         */
 443        /* When probing UNCONFIRMED addresses, the association overall
 444         * error count is NOT incremented
 445         */
 446        if (transport->state != SCTP_UNCONFIRMED)
 447                asoc->overall_error_count++;
 448
 449        if (transport->state != SCTP_INACTIVE &&
 450            (transport->error_count++ >= transport->pathmaxrxt)) {
 451                SCTP_DEBUG_PRINTK_IPADDR("transport_strike:association %p",
 452                                         " transport IP: port:%d failed.\n",
 453                                         asoc,
 454                                         (&transport->ipaddr),
 455                                         ntohs(transport->ipaddr.v4.sin_port));
 456                sctp_assoc_control_transport(asoc, transport,
 457                                             SCTP_TRANSPORT_DOWN,
 458                                             SCTP_FAILED_THRESHOLD);
 459        }
 460
 461        /* E2) For the destination address for which the timer
 462         * expires, set RTO <- RTO * 2 ("back off the timer").  The
 463         * maximum value discussed in rule C7 above (RTO.max) may be
 464         * used to provide an upper bound to this doubling operation.
 465         *
 466         * Special Case:  the first HB doesn't trigger exponential backoff.
 467         * The first unacknowleged HB triggers it.  We do this with a flag
 468         * that indicates that we have an outstanding HB.
 469         */
 470        if (!is_hb || transport->hb_sent) {
 471                transport->last_rto = transport->rto;
 472                transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
 473        }
 474}
 475
 476/* Worker routine to handle INIT command failure.  */
 477static void sctp_cmd_init_failed(sctp_cmd_seq_t *commands,
 478                                 struct sctp_association *asoc,
 479                                 unsigned error)
 480{
 481        struct sctp_ulpevent *event;
 482
 483        event = sctp_ulpevent_make_assoc_change(asoc,0, SCTP_CANT_STR_ASSOC,
 484                                                (__u16)error, 0, 0, NULL,
 485                                                GFP_ATOMIC);
 486
 487        if (event)
 488                sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 489                                SCTP_ULPEVENT(event));
 490
 491        sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 492                        SCTP_STATE(SCTP_STATE_CLOSED));
 493
 494        /* SEND_FAILED sent later when cleaning up the association. */
 495        asoc->outqueue.error = error;
 496        sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 497}
 498
 499/* Worker routine to handle SCTP_CMD_ASSOC_FAILED.  */
 500static void sctp_cmd_assoc_failed(sctp_cmd_seq_t *commands,
 501                                  struct sctp_association *asoc,
 502                                  sctp_event_t event_type,
 503                                  sctp_subtype_t subtype,
 504                                  struct sctp_chunk *chunk,
 505                                  unsigned error)
 506{
 507        struct sctp_ulpevent *event;
 508
 509        /* Cancel any partial delivery in progress. */
 510        sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
 511
 512        if (event_type == SCTP_EVENT_T_CHUNK && subtype.chunk == SCTP_CID_ABORT)
 513                event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
 514                                                (__u16)error, 0, 0, chunk,
 515                                                GFP_ATOMIC);
 516        else
 517                event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
 518                                                (__u16)error, 0, 0, NULL,
 519                                                GFP_ATOMIC);
 520        if (event)
 521                sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 522                                SCTP_ULPEVENT(event));
 523
 524        sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 525                        SCTP_STATE(SCTP_STATE_CLOSED));
 526
 527        /* SEND_FAILED sent later when cleaning up the association. */
 528        asoc->outqueue.error = error;
 529        sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 530}
 531
 532/* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
 533 * inside the cookie.  In reality, this is only used for INIT-ACK processing
 534 * since all other cases use "temporary" associations and can do all
 535 * their work in statefuns directly.
 536 */
 537static int sctp_cmd_process_init(sctp_cmd_seq_t *commands,
 538                                 struct sctp_association *asoc,
 539                                 struct sctp_chunk *chunk,
 540                                 sctp_init_chunk_t *peer_init,
 541                                 gfp_t gfp)
 542{
 543        int error;
 544
 545        /* We only process the init as a sideeffect in a single
 546         * case.   This is when we process the INIT-ACK.   If we
 547         * fail during INIT processing (due to malloc problems),
 548         * just return the error and stop processing the stack.
 549         */
 550        if (!sctp_process_init(asoc, chunk->chunk_hdr->type,
 551                               sctp_source(chunk), peer_init, gfp))
 552                error = -ENOMEM;
 553        else
 554                error = 0;
 555
 556        return error;
 557}
 558
 559/* Helper function to break out starting up of heartbeat timers.  */
 560static void sctp_cmd_hb_timers_start(sctp_cmd_seq_t *cmds,
 561                                     struct sctp_association *asoc)
 562{
 563        struct sctp_transport *t;
 564
 565        /* Start a heartbeat timer for each transport on the association.
 566         * hold a reference on the transport to make sure none of
 567         * the needed data structures go away.
 568         */
 569        list_for_each_entry(t, &asoc->peer.transport_addr_list, transports) {
 570
 571                if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 572                        sctp_transport_hold(t);
 573        }
 574}
 575
 576static void sctp_cmd_hb_timers_stop(sctp_cmd_seq_t *cmds,
 577                                    struct sctp_association *asoc)
 578{
 579        struct sctp_transport *t;
 580
 581        /* Stop all heartbeat timers. */
 582
 583        list_for_each_entry(t, &asoc->peer.transport_addr_list,
 584                        transports) {
 585                if (del_timer(&t->hb_timer))
 586                        sctp_transport_put(t);
 587        }
 588}
 589
 590/* Helper function to stop any pending T3-RTX timers */
 591static void sctp_cmd_t3_rtx_timers_stop(sctp_cmd_seq_t *cmds,
 592                                        struct sctp_association *asoc)
 593{
 594        struct sctp_transport *t;
 595
 596        list_for_each_entry(t, &asoc->peer.transport_addr_list,
 597                        transports) {
 598                if (timer_pending(&t->T3_rtx_timer) &&
 599                    del_timer(&t->T3_rtx_timer)) {
 600                        sctp_transport_put(t);
 601                }
 602        }
 603}
 604
 605
 606/* Helper function to update the heartbeat timer. */
 607static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
 608                                     struct sctp_transport *t)
 609{
 610        /* Update the heartbeat timer.  */
 611        if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 612                sctp_transport_hold(t);
 613}
 614
 615/* Helper function to handle the reception of an HEARTBEAT ACK.  */
 616static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds,
 617                                  struct sctp_association *asoc,
 618                                  struct sctp_transport *t,
 619                                  struct sctp_chunk *chunk)
 620{
 621        sctp_sender_hb_info_t *hbinfo;
 622
 623        /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
 624         * HEARTBEAT should clear the error counter of the destination
 625         * transport address to which the HEARTBEAT was sent.
 626         * The association's overall error count is also cleared.
 627         */
 628        t->error_count = 0;
 629        t->asoc->overall_error_count = 0;
 630
 631        /* Clear the hb_sent flag to signal that we had a good
 632         * acknowledgement.
 633         */
 634        t->hb_sent = 0;
 635
 636        /* Mark the destination transport address as active if it is not so
 637         * marked.
 638         */
 639        if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED))
 640                sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
 641                                             SCTP_HEARTBEAT_SUCCESS);
 642
 643        /* The receiver of the HEARTBEAT ACK should also perform an
 644         * RTT measurement for that destination transport address
 645         * using the time value carried in the HEARTBEAT ACK chunk.
 646         * If the transport's rto_pending variable has been cleared,
 647         * it was most likely due to a retransmit.  However, we want
 648         * to re-enable it to properly update the rto.
 649         */
 650        if (t->rto_pending == 0)
 651                t->rto_pending = 1;
 652
 653        hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
 654        sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
 655
 656        /* Update the heartbeat timer.  */
 657        if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 658                sctp_transport_hold(t);
 659}
 660
 661
 662/* Helper function to process the process SACK command.  */
 663static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds,
 664                                 struct sctp_association *asoc,
 665                                 struct sctp_sackhdr *sackh)
 666{
 667        int err = 0;
 668
 669        if (sctp_outq_sack(&asoc->outqueue, sackh)) {
 670                /* There are no more TSNs awaiting SACK.  */
 671                err = sctp_do_sm(SCTP_EVENT_T_OTHER,
 672                                 SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
 673                                 asoc->state, asoc->ep, asoc, NULL,
 674                                 GFP_ATOMIC);
 675        }
 676
 677        return err;
 678}
 679
 680/* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
 681 * the transport for a shutdown chunk.
 682 */
 683static void sctp_cmd_setup_t2(sctp_cmd_seq_t *cmds,
 684                              struct sctp_association *asoc,
 685                              struct sctp_chunk *chunk)
 686{
 687        struct sctp_transport *t;
 688
 689        t = sctp_assoc_choose_shutdown_transport(asoc);
 690        asoc->shutdown_last_sent_to = t;
 691        asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
 692        chunk->transport = t;
 693}
 694
 695/* Helper function to change the state of an association. */
 696static void sctp_cmd_new_state(sctp_cmd_seq_t *cmds,
 697                               struct sctp_association *asoc,
 698                               sctp_state_t state)
 699{
 700        struct sock *sk = asoc->base.sk;
 701
 702        asoc->state = state;
 703
 704        SCTP_DEBUG_PRINTK("sctp_cmd_new_state: asoc %p[%s]\n",
 705                          asoc, sctp_state_tbl[state]);
 706
 707        if (sctp_style(sk, TCP)) {
 708                /* Change the sk->sk_state of a TCP-style socket that has
 709                 * sucessfully completed a connect() call.
 710                 */
 711                if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
 712                        sk->sk_state = SCTP_SS_ESTABLISHED;
 713
 714                /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
 715                if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
 716                    sctp_sstate(sk, ESTABLISHED))
 717                        sk->sk_shutdown |= RCV_SHUTDOWN;
 718        }
 719
 720        if (sctp_state(asoc, COOKIE_WAIT)) {
 721                /* Reset init timeouts since they may have been
 722                 * increased due to timer expirations.
 723                 */
 724                asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
 725                                                asoc->rto_initial;
 726                asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
 727                                                asoc->rto_initial;
 728        }
 729
 730        if (sctp_state(asoc, ESTABLISHED) ||
 731            sctp_state(asoc, CLOSED) ||
 732            sctp_state(asoc, SHUTDOWN_RECEIVED)) {
 733                /* Wake up any processes waiting in the asoc's wait queue in
 734                 * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
 735                 */
 736                if (waitqueue_active(&asoc->wait))
 737                        wake_up_interruptible(&asoc->wait);
 738
 739                /* Wake up any processes waiting in the sk's sleep queue of
 740                 * a TCP-style or UDP-style peeled-off socket in
 741                 * sctp_wait_for_accept() or sctp_wait_for_packet().
 742                 * For a UDP-style socket, the waiters are woken up by the
 743                 * notifications.
 744                 */
 745                if (!sctp_style(sk, UDP))
 746                        sk->sk_state_change(sk);
 747        }
 748}
 749
 750/* Helper function to delete an association. */
 751static void sctp_cmd_delete_tcb(sctp_cmd_seq_t *cmds,
 752                                struct sctp_association *asoc)
 753{
 754        struct sock *sk = asoc->base.sk;
 755
 756        /* If it is a non-temporary association belonging to a TCP-style
 757         * listening socket that is not closed, do not free it so that accept()
 758         * can pick it up later.
 759         */
 760        if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
 761            (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
 762                return;
 763
 764        sctp_unhash_established(asoc);
 765        sctp_association_free(asoc);
 766}
 767
 768/*
 769 * ADDIP Section 4.1 ASCONF Chunk Procedures
 770 * A4) Start a T-4 RTO timer, using the RTO value of the selected
 771 * destination address (we use active path instead of primary path just
 772 * because primary path may be inactive.
 773 */
 774static void sctp_cmd_setup_t4(sctp_cmd_seq_t *cmds,
 775                                struct sctp_association *asoc,
 776                                struct sctp_chunk *chunk)
 777{
 778        struct sctp_transport *t;
 779
 780        t = asoc->peer.active_path;
 781        asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
 782        chunk->transport = t;
 783}
 784
 785/* Process an incoming Operation Error Chunk. */
 786static void sctp_cmd_process_operr(sctp_cmd_seq_t *cmds,
 787                                   struct sctp_association *asoc,
 788                                   struct sctp_chunk *chunk)
 789{
 790        struct sctp_errhdr *err_hdr;
 791        struct sctp_ulpevent *ev;
 792
 793        while (chunk->chunk_end > chunk->skb->data) {
 794                err_hdr = (struct sctp_errhdr *)(chunk->skb->data);
 795
 796                ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
 797                                                     GFP_ATOMIC);
 798                if (!ev)
 799                        return;
 800
 801                sctp_ulpq_tail_event(&asoc->ulpq, ev);
 802
 803                switch (err_hdr->cause) {
 804                case SCTP_ERROR_UNKNOWN_CHUNK:
 805                {
 806                        sctp_chunkhdr_t *unk_chunk_hdr;
 807
 808                        unk_chunk_hdr = (sctp_chunkhdr_t *)err_hdr->variable;
 809                        switch (unk_chunk_hdr->type) {
 810                        /* ADDIP 4.1 A9) If the peer responds to an ASCONF with
 811                         * an ERROR chunk reporting that it did not recognized
 812                         * the ASCONF chunk type, the sender of the ASCONF MUST
 813                         * NOT send any further ASCONF chunks and MUST stop its
 814                         * T-4 timer.
 815                         */
 816                        case SCTP_CID_ASCONF:
 817                                if (asoc->peer.asconf_capable == 0)
 818                                        break;
 819
 820                                asoc->peer.asconf_capable = 0;
 821                                sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
 822                                        SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
 823                                break;
 824                        default:
 825                                break;
 826                        }
 827                        break;
 828                }
 829                default:
 830                        break;
 831                }
 832        }
 833}
 834
 835/* Process variable FWDTSN chunk information. */
 836static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq,
 837                                    struct sctp_chunk *chunk)
 838{
 839        struct sctp_fwdtsn_skip *skip;
 840        /* Walk through all the skipped SSNs */
 841        sctp_walk_fwdtsn(skip, chunk) {
 842                sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
 843        }
 844
 845        return;
 846}
 847
 848/* Helper function to remove the association non-primary peer
 849 * transports.
 850 */
 851static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
 852{
 853        struct sctp_transport *t;
 854        struct list_head *pos;
 855        struct list_head *temp;
 856
 857        list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
 858                t = list_entry(pos, struct sctp_transport, transports);
 859                if (!sctp_cmp_addr_exact(&t->ipaddr,
 860                                         &asoc->peer.primary_addr)) {
 861                        sctp_assoc_del_peer(asoc, &t->ipaddr);
 862                }
 863        }
 864
 865        return;
 866}
 867
 868/* Helper function to set sk_err on a 1-1 style socket. */
 869static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
 870{
 871        struct sock *sk = asoc->base.sk;
 872
 873        if (!sctp_style(sk, UDP))
 874                sk->sk_err = error;
 875}
 876
 877/* Helper function to generate an association change event */
 878static void sctp_cmd_assoc_change(sctp_cmd_seq_t *commands,
 879                                 struct sctp_association *asoc,
 880                                 u8 state)
 881{
 882        struct sctp_ulpevent *ev;
 883
 884        ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0,
 885                                            asoc->c.sinit_num_ostreams,
 886                                            asoc->c.sinit_max_instreams,
 887                                            NULL, GFP_ATOMIC);
 888        if (ev)
 889                sctp_ulpq_tail_event(&asoc->ulpq, ev);
 890}
 891
 892/* Helper function to generate an adaptation indication event */
 893static void sctp_cmd_adaptation_ind(sctp_cmd_seq_t *commands,
 894                                    struct sctp_association *asoc)
 895{
 896        struct sctp_ulpevent *ev;
 897
 898        ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
 899
 900        if (ev)
 901                sctp_ulpq_tail_event(&asoc->ulpq, ev);
 902}
 903
 904
 905static void sctp_cmd_t1_timer_update(struct sctp_association *asoc,
 906                                    sctp_event_timeout_t timer,
 907                                    char *name)
 908{
 909        struct sctp_transport *t;
 910
 911        t = asoc->init_last_sent_to;
 912        asoc->init_err_counter++;
 913
 914        if (t->init_sent_count > (asoc->init_cycle + 1)) {
 915                asoc->timeouts[timer] *= 2;
 916                if (asoc->timeouts[timer] > asoc->max_init_timeo) {
 917                        asoc->timeouts[timer] = asoc->max_init_timeo;
 918                }
 919                asoc->init_cycle++;
 920                SCTP_DEBUG_PRINTK(
 921                        "T1 %s Timeout adjustment"
 922                        " init_err_counter: %d"
 923                        " cycle: %d"
 924                        " timeout: %ld\n",
 925                        name,
 926                        asoc->init_err_counter,
 927                        asoc->init_cycle,
 928                        asoc->timeouts[timer]);
 929        }
 930
 931}
 932
 933/* These three macros allow us to pull the debugging code out of the
 934 * main flow of sctp_do_sm() to keep attention focused on the real
 935 * functionality there.
 936 */
 937#define DEBUG_PRE \
 938        SCTP_DEBUG_PRINTK("sctp_do_sm prefn: " \
 939                          "ep %p, %s, %s, asoc %p[%s], %s\n", \
 940                          ep, sctp_evttype_tbl[event_type], \
 941                          (*debug_fn)(subtype), asoc, \
 942                          sctp_state_tbl[state], state_fn->name)
 943
 944#define DEBUG_POST \
 945        SCTP_DEBUG_PRINTK("sctp_do_sm postfn: " \
 946                          "asoc %p, status: %s\n", \
 947                          asoc, sctp_status_tbl[status])
 948
 949#define DEBUG_POST_SFX \
 950        SCTP_DEBUG_PRINTK("sctp_do_sm post sfx: error %d, asoc %p[%s]\n", \
 951                          error, asoc, \
 952                          sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
 953                          sctp_assoc2id(asoc)))?asoc->state:SCTP_STATE_CLOSED])
 954
 955/*
 956 * This is the master state machine processing function.
 957 *
 958 * If you want to understand all of lksctp, this is a
 959 * good place to start.
 960 */
 961int sctp_do_sm(sctp_event_t event_type, sctp_subtype_t subtype,
 962               sctp_state_t state,
 963               struct sctp_endpoint *ep,
 964               struct sctp_association *asoc,
 965               void *event_arg,
 966               gfp_t gfp)
 967{
 968        sctp_cmd_seq_t commands;
 969        const sctp_sm_table_entry_t *state_fn;
 970        sctp_disposition_t status;
 971        int error = 0;
 972        typedef const char *(printfn_t)(sctp_subtype_t);
 973
 974        static printfn_t *table[] = {
 975                NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
 976        };
 977        printfn_t *debug_fn  __attribute__ ((unused)) = table[event_type];
 978
 979        /* Look up the state function, run it, and then process the
 980         * side effects.  These three steps are the heart of lksctp.
 981         */
 982        state_fn = sctp_sm_lookup_event(event_type, state, subtype);
 983
 984        sctp_init_cmd_seq(&commands);
 985
 986        DEBUG_PRE;
 987        status = (*state_fn->fn)(ep, asoc, subtype, event_arg, &commands);
 988        DEBUG_POST;
 989
 990        error = sctp_side_effects(event_type, subtype, state,
 991                                  ep, asoc, event_arg, status,
 992                                  &commands, gfp);
 993        DEBUG_POST_SFX;
 994
 995        return error;
 996}
 997
 998#undef DEBUG_PRE
 999#undef DEBUG_POST
1000
1001/*****************************************************************
1002 * This the master state function side effect processing function.
1003 *****************************************************************/
1004static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
1005                             sctp_state_t state,
1006                             struct sctp_endpoint *ep,
1007                             struct sctp_association *asoc,
1008                             void *event_arg,
1009                             sctp_disposition_t status,
1010                             sctp_cmd_seq_t *commands,
1011                             gfp_t gfp)
1012{
1013        int error;
1014
1015        /* FIXME - Most of the dispositions left today would be categorized
1016         * as "exceptional" dispositions.  For those dispositions, it
1017         * may not be proper to run through any of the commands at all.
1018         * For example, the command interpreter might be run only with
1019         * disposition SCTP_DISPOSITION_CONSUME.
1020         */
1021        if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
1022                                               ep, asoc,
1023                                               event_arg, status,
1024                                               commands, gfp)))
1025                goto bail;
1026
1027        switch (status) {
1028        case SCTP_DISPOSITION_DISCARD:
1029                SCTP_DEBUG_PRINTK("Ignored sctp protocol event - state %d, "
1030                                  "event_type %d, event_id %d\n",
1031                                  state, event_type, subtype.chunk);
1032                break;
1033
1034        case SCTP_DISPOSITION_NOMEM:
1035                /* We ran out of memory, so we need to discard this
1036                 * packet.
1037                 */
1038                /* BUG--we should now recover some memory, probably by
1039                 * reneging...
1040                 */
1041                error = -ENOMEM;
1042                break;
1043
1044        case SCTP_DISPOSITION_DELETE_TCB:
1045                /* This should now be a command. */
1046                break;
1047
1048        case SCTP_DISPOSITION_CONSUME:
1049        case SCTP_DISPOSITION_ABORT:
1050                /*
1051                 * We should no longer have much work to do here as the
1052                 * real work has been done as explicit commands above.
1053                 */
1054                break;
1055
1056        case SCTP_DISPOSITION_VIOLATION:
1057                if (net_ratelimit())
1058                        printk(KERN_ERR "sctp protocol violation state %d "
1059                               "chunkid %d\n", state, subtype.chunk);
1060                break;
1061
1062        case SCTP_DISPOSITION_NOT_IMPL:
1063                printk(KERN_WARNING "sctp unimplemented feature in state %d, "
1064                       "event_type %d, event_id %d\n",
1065                       state, event_type, subtype.chunk);
1066                break;
1067
1068        case SCTP_DISPOSITION_BUG:
1069                printk(KERN_ERR "sctp bug in state %d, "
1070                       "event_type %d, event_id %d\n",
1071                       state, event_type, subtype.chunk);
1072                BUG();
1073                break;
1074
1075        default:
1076                printk(KERN_ERR "sctp impossible disposition %d "
1077                       "in state %d, event_type %d, event_id %d\n",
1078                       status, state, event_type, subtype.chunk);
1079                BUG();
1080                break;
1081        }
1082
1083bail:
1084        return error;
1085}
1086
1087/********************************************************************
1088 * 2nd Level Abstractions
1089 ********************************************************************/
1090
1091/* This is the side-effect interpreter.  */
1092static int sctp_cmd_interpreter(sctp_event_t event_type,
1093                                sctp_subtype_t subtype,
1094                                sctp_state_t state,
1095                                struct sctp_endpoint *ep,
1096                                struct sctp_association *asoc,
1097                                void *event_arg,
1098                                sctp_disposition_t status,
1099                                sctp_cmd_seq_t *commands,
1100                                gfp_t gfp)
1101{
1102        int error = 0;
1103        int force;
1104        sctp_cmd_t *cmd;
1105        struct sctp_chunk *new_obj;
1106        struct sctp_chunk *chunk = NULL;
1107        struct sctp_packet *packet;
1108        struct timer_list *timer;
1109        unsigned long timeout;
1110        struct sctp_transport *t;
1111        struct sctp_sackhdr sackh;
1112        int local_cork = 0;
1113
1114        if (SCTP_EVENT_T_TIMEOUT != event_type)
1115                chunk = (struct sctp_chunk *) event_arg;
1116
1117        /* Note:  This whole file is a huge candidate for rework.
1118         * For example, each command could either have its own handler, so
1119         * the loop would look like:
1120         *     while (cmds)
1121         *         cmd->handle(x, y, z)
1122         * --jgrimm
1123         */
1124        while (NULL != (cmd = sctp_next_cmd(commands))) {
1125                switch (cmd->verb) {
1126                case SCTP_CMD_NOP:
1127                        /* Do nothing. */
1128                        break;
1129
1130                case SCTP_CMD_NEW_ASOC:
1131                        /* Register a new association.  */
1132                        if (local_cork) {
1133                                sctp_outq_uncork(&asoc->outqueue);
1134                                local_cork = 0;
1135                        }
1136                        asoc = cmd->obj.ptr;
1137                        /* Register with the endpoint.  */
1138                        sctp_endpoint_add_asoc(ep, asoc);
1139                        sctp_hash_established(asoc);
1140                        break;
1141
1142                case SCTP_CMD_UPDATE_ASSOC:
1143                       sctp_assoc_update(asoc, cmd->obj.ptr);
1144                       break;
1145
1146                case SCTP_CMD_PURGE_OUTQUEUE:
1147                       sctp_outq_teardown(&asoc->outqueue);
1148                       break;
1149
1150                case SCTP_CMD_DELETE_TCB:
1151                        if (local_cork) {
1152                                sctp_outq_uncork(&asoc->outqueue);
1153                                local_cork = 0;
1154                        }
1155                        /* Delete the current association.  */
1156                        sctp_cmd_delete_tcb(commands, asoc);
1157                        asoc = NULL;
1158                        break;
1159
1160                case SCTP_CMD_NEW_STATE:
1161                        /* Enter a new state.  */
1162                        sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1163                        break;
1164
1165                case SCTP_CMD_REPORT_TSN:
1166                        /* Record the arrival of a TSN.  */
1167                        error = sctp_tsnmap_mark(&asoc->peer.tsn_map,
1168                                                 cmd->obj.u32);
1169                        break;
1170
1171                case SCTP_CMD_REPORT_FWDTSN:
1172                        /* Move the Cumulattive TSN Ack ahead. */
1173                        sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32);
1174
1175                        /* purge the fragmentation queue */
1176                        sctp_ulpq_reasm_flushtsn(&asoc->ulpq, cmd->obj.u32);
1177
1178                        /* Abort any in progress partial delivery. */
1179                        sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
1180                        break;
1181
1182                case SCTP_CMD_PROCESS_FWDTSN:
1183                        sctp_cmd_process_fwdtsn(&asoc->ulpq, cmd->obj.ptr);
1184                        break;
1185
1186                case SCTP_CMD_GEN_SACK:
1187                        /* Generate a Selective ACK.
1188                         * The argument tells us whether to just count
1189                         * the packet and MAYBE generate a SACK, or
1190                         * force a SACK out.
1191                         */
1192                        force = cmd->obj.i32;
1193                        error = sctp_gen_sack(asoc, force, commands);
1194                        break;
1195
1196                case SCTP_CMD_PROCESS_SACK:
1197                        /* Process an inbound SACK.  */
1198                        error = sctp_cmd_process_sack(commands, asoc,
1199                                                      cmd->obj.ptr);
1200                        break;
1201
1202                case SCTP_CMD_GEN_INIT_ACK:
1203                        /* Generate an INIT ACK chunk.  */
1204                        new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1205                                                     0);
1206                        if (!new_obj)
1207                                goto nomem;
1208
1209                        sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1210                                        SCTP_CHUNK(new_obj));
1211                        break;
1212
1213                case SCTP_CMD_PEER_INIT:
1214                        /* Process a unified INIT from the peer.
1215                         * Note: Only used during INIT-ACK processing.  If
1216                         * there is an error just return to the outter
1217                         * layer which will bail.
1218                         */
1219                        error = sctp_cmd_process_init(commands, asoc, chunk,
1220                                                      cmd->obj.ptr, gfp);
1221                        break;
1222
1223                case SCTP_CMD_GEN_COOKIE_ECHO:
1224                        /* Generate a COOKIE ECHO chunk.  */
1225                        new_obj = sctp_make_cookie_echo(asoc, chunk);
1226                        if (!new_obj) {
1227                                if (cmd->obj.ptr)
1228                                        sctp_chunk_free(cmd->obj.ptr);
1229                                goto nomem;
1230                        }
1231                        sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1232                                        SCTP_CHUNK(new_obj));
1233
1234                        /* If there is an ERROR chunk to be sent along with
1235                         * the COOKIE_ECHO, send it, too.
1236                         */
1237                        if (cmd->obj.ptr)
1238                                sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1239                                                SCTP_CHUNK(cmd->obj.ptr));
1240
1241                        if (new_obj->transport) {
1242                                new_obj->transport->init_sent_count++;
1243                                asoc->init_last_sent_to = new_obj->transport;
1244                        }
1245
1246                        /* FIXME - Eventually come up with a cleaner way to
1247                         * enabling COOKIE-ECHO + DATA bundling during
1248                         * multihoming stale cookie scenarios, the following
1249                         * command plays with asoc->peer.retran_path to
1250                         * avoid the problem of sending the COOKIE-ECHO and
1251                         * DATA in different paths, which could result
1252                         * in the association being ABORTed if the DATA chunk
1253                         * is processed first by the server.  Checking the
1254                         * init error counter simply causes this command
1255                         * to be executed only during failed attempts of
1256                         * association establishment.
1257                         */
1258                        if ((asoc->peer.retran_path !=
1259                             asoc->peer.primary_path) &&
1260                            (asoc->init_err_counter > 0)) {
1261                                sctp_add_cmd_sf(commands,
1262                                                SCTP_CMD_FORCE_PRIM_RETRAN,
1263                                                SCTP_NULL());
1264                        }
1265
1266                        break;
1267
1268                case SCTP_CMD_GEN_SHUTDOWN:
1269                        /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1270                         * Reset error counts.
1271                         */
1272                        asoc->overall_error_count = 0;
1273
1274                        /* Generate a SHUTDOWN chunk.  */
1275                        new_obj = sctp_make_shutdown(asoc, chunk);
1276                        if (!new_obj)
1277                                goto nomem;
1278                        sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1279                                        SCTP_CHUNK(new_obj));
1280                        break;
1281
1282                case SCTP_CMD_CHUNK_ULP:
1283                        /* Send a chunk to the sockets layer.  */
1284                        SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1285                                          "chunk_up:", cmd->obj.ptr,
1286                                          "ulpq:", &asoc->ulpq);
1287                        sctp_ulpq_tail_data(&asoc->ulpq, cmd->obj.ptr,
1288                                            GFP_ATOMIC);
1289                        break;
1290
1291                case SCTP_CMD_EVENT_ULP:
1292                        /* Send a notification to the sockets layer.  */
1293                        SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1294                                          "event_up:",cmd->obj.ptr,
1295                                          "ulpq:",&asoc->ulpq);
1296                        sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ptr);
1297                        break;
1298
1299                case SCTP_CMD_REPLY:
1300                        /* If an caller has not already corked, do cork. */
1301                        if (!asoc->outqueue.cork) {
1302                                sctp_outq_cork(&asoc->outqueue);
1303                                local_cork = 1;
1304                        }
1305                        /* Send a chunk to our peer.  */
1306                        error = sctp_outq_tail(&asoc->outqueue, cmd->obj.ptr);
1307                        break;
1308
1309                case SCTP_CMD_SEND_PKT:
1310                        /* Send a full packet to our peer.  */
1311                        packet = cmd->obj.ptr;
1312                        sctp_packet_transmit(packet);
1313                        sctp_ootb_pkt_free(packet);
1314                        break;
1315
1316                case SCTP_CMD_T1_RETRAN:
1317                        /* Mark a transport for retransmission.  */
1318                        sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1319                                        SCTP_RTXR_T1_RTX);
1320                        break;
1321
1322                case SCTP_CMD_RETRAN:
1323                        /* Mark a transport for retransmission.  */
1324                        sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1325                                        SCTP_RTXR_T3_RTX);
1326                        break;
1327
1328                case SCTP_CMD_TRANSMIT:
1329                        /* Kick start transmission. */
1330                        error = sctp_outq_uncork(&asoc->outqueue);
1331                        local_cork = 0;
1332                        break;
1333
1334                case SCTP_CMD_ECN_CE:
1335                        /* Do delayed CE processing.   */
1336                        sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1337                        break;
1338
1339                case SCTP_CMD_ECN_ECNE:
1340                        /* Do delayed ECNE processing. */
1341                        new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1342                                                        chunk);
1343                        if (new_obj)
1344                                sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1345                                                SCTP_CHUNK(new_obj));
1346                        break;
1347
1348                case SCTP_CMD_ECN_CWR:
1349                        /* Do delayed CWR processing.  */
1350                        sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1351                        break;
1352
1353                case SCTP_CMD_SETUP_T2:
1354                        sctp_cmd_setup_t2(commands, asoc, cmd->obj.ptr);
1355                        break;
1356
1357                case SCTP_CMD_TIMER_START:
1358                        timer = &asoc->timers[cmd->obj.to];
1359                        timeout = asoc->timeouts[cmd->obj.to];
1360                        BUG_ON(!timeout);
1361
1362                        timer->expires = jiffies + timeout;
1363                        sctp_association_hold(asoc);
1364                        add_timer(timer);
1365                        break;
1366
1367                case SCTP_CMD_TIMER_RESTART:
1368                        timer = &asoc->timers[cmd->obj.to];
1369                        timeout = asoc->timeouts[cmd->obj.to];
1370                        if (!mod_timer(timer, jiffies + timeout))
1371                                sctp_association_hold(asoc);
1372                        break;
1373
1374                case SCTP_CMD_TIMER_STOP:
1375                        timer = &asoc->timers[cmd->obj.to];
1376                        if (timer_pending(timer) && del_timer(timer))
1377                                sctp_association_put(asoc);
1378                        break;
1379
1380                case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1381                        chunk = cmd->obj.ptr;
1382                        t = sctp_assoc_choose_init_transport(asoc);
1383                        asoc->init_last_sent_to = t;
1384                        chunk->transport = t;
1385                        t->init_sent_count++;
1386                        break;
1387
1388                case SCTP_CMD_INIT_RESTART:
1389                        /* Do the needed accounting and updates
1390                         * associated with restarting an initialization
1391                         * timer. Only multiply the timeout by two if
1392                         * all transports have been tried at the current
1393                         * timeout.
1394                         */
1395                        sctp_cmd_t1_timer_update(asoc,
1396                                                SCTP_EVENT_TIMEOUT_T1_INIT,
1397                                                "INIT");
1398
1399                        sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1400                                        SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1401                        break;
1402
1403                case SCTP_CMD_COOKIEECHO_RESTART:
1404                        /* Do the needed accounting and updates
1405                         * associated with restarting an initialization
1406                         * timer. Only multiply the timeout by two if
1407                         * all transports have been tried at the current
1408                         * timeout.
1409                         */
1410                        sctp_cmd_t1_timer_update(asoc,
1411                                                SCTP_EVENT_TIMEOUT_T1_COOKIE,
1412                                                "COOKIE");
1413
1414                        /* If we've sent any data bundled with
1415                         * COOKIE-ECHO we need to resend.
1416                         */
1417                        list_for_each_entry(t, &asoc->peer.transport_addr_list,
1418                                        transports) {
1419                                sctp_retransmit_mark(&asoc->outqueue, t,
1420                                            SCTP_RTXR_T1_RTX);
1421                        }
1422
1423                        sctp_add_cmd_sf(commands,
1424                                        SCTP_CMD_TIMER_RESTART,
1425                                        SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1426                        break;
1427
1428                case SCTP_CMD_INIT_FAILED:
1429                        sctp_cmd_init_failed(commands, asoc, cmd->obj.err);
1430                        break;
1431
1432                case SCTP_CMD_ASSOC_FAILED:
1433                        sctp_cmd_assoc_failed(commands, asoc, event_type,
1434                                              subtype, chunk, cmd->obj.err);
1435                        break;
1436
1437                case SCTP_CMD_INIT_COUNTER_INC:
1438                        asoc->init_err_counter++;
1439                        break;
1440
1441                case SCTP_CMD_INIT_COUNTER_RESET:
1442                        asoc->init_err_counter = 0;
1443                        asoc->init_cycle = 0;
1444                        list_for_each_entry(t, &asoc->peer.transport_addr_list,
1445                                            transports) {
1446                                t->init_sent_count = 0;
1447                        }
1448                        break;
1449
1450                case SCTP_CMD_REPORT_DUP:
1451                        sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1452                                             cmd->obj.u32);
1453                        break;
1454
1455                case SCTP_CMD_REPORT_BAD_TAG:
1456                        SCTP_DEBUG_PRINTK("vtag mismatch!\n");
1457                        break;
1458
1459                case SCTP_CMD_STRIKE:
1460                        /* Mark one strike against a transport.  */
1461                        sctp_do_8_2_transport_strike(asoc, cmd->obj.transport,
1462                                                    0);
1463                        break;
1464
1465                case SCTP_CMD_TRANSPORT_IDLE:
1466                        t = cmd->obj.transport;
1467                        sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
1468                        break;
1469
1470                case SCTP_CMD_TRANSPORT_HB_SENT:
1471                        t = cmd->obj.transport;
1472                        sctp_do_8_2_transport_strike(asoc, t, 1);
1473                        t->hb_sent = 1;
1474                        break;
1475
1476                case SCTP_CMD_TRANSPORT_ON:
1477                        t = cmd->obj.transport;
1478                        sctp_cmd_transport_on(commands, asoc, t, chunk);
1479                        break;
1480
1481                case SCTP_CMD_HB_TIMERS_START:
1482                        sctp_cmd_hb_timers_start(commands, asoc);
1483                        break;
1484
1485                case SCTP_CMD_HB_TIMER_UPDATE:
1486                        t = cmd->obj.transport;
1487                        sctp_cmd_hb_timer_update(commands, t);
1488                        break;
1489
1490                case SCTP_CMD_HB_TIMERS_STOP:
1491                        sctp_cmd_hb_timers_stop(commands, asoc);
1492                        break;
1493
1494                case SCTP_CMD_REPORT_ERROR:
1495                        error = cmd->obj.error;
1496                        break;
1497
1498                case SCTP_CMD_PROCESS_CTSN:
1499                        /* Dummy up a SACK for processing. */
1500                        sackh.cum_tsn_ack = cmd->obj.be32;
1501                        sackh.a_rwnd = 0;
1502                        sackh.num_gap_ack_blocks = 0;
1503                        sackh.num_dup_tsns = 0;
1504                        sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1505                                        SCTP_SACKH(&sackh));
1506                        break;
1507
1508                case SCTP_CMD_DISCARD_PACKET:
1509                        /* We need to discard the whole packet.
1510                         * Uncork the queue since there might be
1511                         * responses pending
1512                         */
1513                        chunk->pdiscard = 1;
1514                        if (asoc) {
1515                                sctp_outq_uncork(&asoc->outqueue);
1516                                local_cork = 0;
1517                        }
1518                        break;
1519
1520                case SCTP_CMD_RTO_PENDING:
1521                        t = cmd->obj.transport;
1522                        t->rto_pending = 1;
1523                        break;
1524
1525                case SCTP_CMD_PART_DELIVER:
1526                        sctp_ulpq_partial_delivery(&asoc->ulpq, cmd->obj.ptr,
1527                                                   GFP_ATOMIC);
1528                        break;
1529
1530                case SCTP_CMD_RENEGE:
1531                        sctp_ulpq_renege(&asoc->ulpq, cmd->obj.ptr,
1532                                         GFP_ATOMIC);
1533                        break;
1534
1535                case SCTP_CMD_SETUP_T4:
1536                        sctp_cmd_setup_t4(commands, asoc, cmd->obj.ptr);
1537                        break;
1538
1539                case SCTP_CMD_PROCESS_OPERR:
1540                        sctp_cmd_process_operr(commands, asoc, chunk);
1541                        break;
1542                case SCTP_CMD_CLEAR_INIT_TAG:
1543                        asoc->peer.i.init_tag = 0;
1544                        break;
1545                case SCTP_CMD_DEL_NON_PRIMARY:
1546                        sctp_cmd_del_non_primary(asoc);
1547                        break;
1548                case SCTP_CMD_T3_RTX_TIMERS_STOP:
1549                        sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1550                        break;
1551                case SCTP_CMD_FORCE_PRIM_RETRAN:
1552                        t = asoc->peer.retran_path;
1553                        asoc->peer.retran_path = asoc->peer.primary_path;
1554                        error = sctp_outq_uncork(&asoc->outqueue);
1555                        local_cork = 0;
1556                        asoc->peer.retran_path = t;
1557                        break;
1558                case SCTP_CMD_SET_SK_ERR:
1559                        sctp_cmd_set_sk_err(asoc, cmd->obj.error);
1560                        break;
1561                case SCTP_CMD_ASSOC_CHANGE:
1562                        sctp_cmd_assoc_change(commands, asoc,
1563                                              cmd->obj.u8);
1564                        break;
1565                case SCTP_CMD_ADAPTATION_IND:
1566                        sctp_cmd_adaptation_ind(commands, asoc);
1567                        break;
1568
1569                case SCTP_CMD_ASSOC_SHKEY:
1570                        error = sctp_auth_asoc_init_active_key(asoc,
1571                                                GFP_ATOMIC);
1572                        break;
1573                case SCTP_CMD_UPDATE_INITTAG:
1574                        asoc->peer.i.init_tag = cmd->obj.u32;
1575                        break;
1576
1577                default:
1578                        printk(KERN_WARNING "Impossible command: %u, %p\n",
1579                               cmd->verb, cmd->obj.ptr);
1580                        break;
1581                }
1582
1583                if (error)
1584                        break;
1585        }
1586
1587out:
1588        /* If this is in response to a received chunk, wait until
1589         * we are done with the packet to open the queue so that we don't
1590         * send multiple packets in response to a single request.
1591         */
1592        if (asoc && SCTP_EVENT_T_CHUNK == event_type && chunk) {
1593                if (chunk->end_of_packet || chunk->singleton)
1594                        sctp_outq_uncork(&asoc->outqueue);
1595        } else if (local_cork)
1596                        sctp_outq_uncork(&asoc->outqueue);
1597        return error;
1598nomem:
1599        error = -ENOMEM;
1600        goto out;
1601}
1602
1603