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 <linux/gfp.h>
  55#include <net/sock.h>
  56#include <net/sctp/sctp.h>
  57#include <net/sctp/sm.h>
  58
  59static int sctp_cmd_interpreter(sctp_event_t event_type,
  60                                sctp_subtype_t subtype,
  61                                sctp_state_t state,
  62                                struct sctp_endpoint *ep,
  63                                struct sctp_association *asoc,
  64                                void *event_arg,
  65                                sctp_disposition_t status,
  66                                sctp_cmd_seq_t *commands,
  67                                gfp_t gfp);
  68static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
  69                             sctp_state_t state,
  70                             struct sctp_endpoint *ep,
  71                             struct sctp_association *asoc,
  72                             void *event_arg,
  73                             sctp_disposition_t status,
  74                             sctp_cmd_seq_t *commands,
  75                             gfp_t gfp);
  76
  77/********************************************************************
  78 * Helper functions
  79 ********************************************************************/
  80
  81/* A helper function for delayed processing of INET ECN CE bit. */
  82static void sctp_do_ecn_ce_work(struct sctp_association *asoc,
  83                                __u32 lowest_tsn)
  84{
  85        /* Save the TSN away for comparison when we receive CWR */
  86
  87        asoc->last_ecne_tsn = lowest_tsn;
  88        asoc->need_ecne = 1;
  89}
  90
  91/* Helper function for delayed processing of SCTP ECNE chunk.  */
  92/* RFC 2960 Appendix A
  93 *
  94 * RFC 2481 details a specific bit for a sender to send in
  95 * the header of its next outbound TCP segment to indicate to
  96 * its peer that it has reduced its congestion window.  This
  97 * is termed the CWR bit.  For SCTP the same indication is made
  98 * by including the CWR chunk.  This chunk contains one data
  99 * element, i.e. the TSN number that was sent in the ECNE chunk.
 100 * This element represents the lowest TSN number in the datagram
 101 * that was originally marked with the CE bit.
 102 */
 103static struct sctp_chunk *sctp_do_ecn_ecne_work(struct sctp_association *asoc,
 104                                           __u32 lowest_tsn,
 105                                           struct sctp_chunk *chunk)
 106{
 107        struct sctp_chunk *repl;
 108
 109        /* Our previously transmitted packet ran into some congestion
 110         * so we should take action by reducing cwnd and ssthresh
 111         * and then ACK our peer that we we've done so by
 112         * sending a CWR.
 113         */
 114
 115        /* First, try to determine if we want to actually lower
 116         * our cwnd variables.  Only lower them if the ECNE looks more
 117         * recent than the last response.
 118         */
 119        if (TSN_lt(asoc->last_cwr_tsn, lowest_tsn)) {
 120                struct sctp_transport *transport;
 121
 122                /* Find which transport's congestion variables
 123                 * need to be adjusted.
 124                 */
 125                transport = sctp_assoc_lookup_tsn(asoc, lowest_tsn);
 126
 127                /* Update the congestion variables. */
 128                if (transport)
 129                        sctp_transport_lower_cwnd(transport,
 130                                                  SCTP_LOWER_CWND_ECNE);
 131                asoc->last_cwr_tsn = lowest_tsn;
 132        }
 133
 134        /* Always try to quiet the other end.  In case of lost CWR,
 135         * resend last_cwr_tsn.
 136         */
 137        repl = sctp_make_cwr(asoc, asoc->last_cwr_tsn, chunk);
 138
 139        /* If we run out of memory, it will look like a lost CWR.  We'll
 140         * get back in sync eventually.
 141         */
 142        return repl;
 143}
 144
 145/* Helper function to do delayed processing of ECN CWR chunk.  */
 146static void sctp_do_ecn_cwr_work(struct sctp_association *asoc,
 147                                 __u32 lowest_tsn)
 148{
 149        /* Turn off ECNE getting auto-prepended to every outgoing
 150         * packet
 151         */
 152        asoc->need_ecne = 0;
 153}
 154
 155/* Generate SACK if necessary.  We call this at the end of a packet.  */
 156static int sctp_gen_sack(struct sctp_association *asoc, int force,
 157                         sctp_cmd_seq_t *commands)
 158{
 159        __u32 ctsn, max_tsn_seen;
 160        struct sctp_chunk *sack;
 161        struct sctp_transport *trans = asoc->peer.last_data_from;
 162        int error = 0;
 163
 164        if (force ||
 165            (!trans && (asoc->param_flags & SPP_SACKDELAY_DISABLE)) ||
 166            (trans && (trans->param_flags & SPP_SACKDELAY_DISABLE)))
 167                asoc->peer.sack_needed = 1;
 168
 169        ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
 170        max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
 171
 172        /* From 12.2 Parameters necessary per association (i.e. the TCB):
 173         *
 174         * Ack State : This flag indicates if the next received packet
 175         *           : is to be responded to with a SACK. ...
 176         *           : When DATA chunks are out of order, SACK's
 177         *           : are not delayed (see Section 6).
 178         *
 179         * [This is actually not mentioned in Section 6, but we
 180         * implement it here anyway. --piggy]
 181         */
 182        if (max_tsn_seen != ctsn)
 183                asoc->peer.sack_needed = 1;
 184
 185        /* From 6.2  Acknowledgement on Reception of DATA Chunks:
 186         *
 187         * Section 4.2 of [RFC2581] SHOULD be followed. Specifically,
 188         * an acknowledgement SHOULD be generated for at least every
 189         * second packet (not every second DATA chunk) received, and
 190         * SHOULD be generated within 200 ms of the arrival of any
 191         * unacknowledged DATA chunk. ...
 192         */
 193        if (!asoc->peer.sack_needed) {
 194                asoc->peer.sack_cnt++;
 195
 196                /* Set the SACK delay timeout based on the
 197                 * SACK delay for the last transport
 198                 * data was received from, or the default
 199                 * for the association.
 200                 */
 201                if (trans) {
 202                        /* We will need a SACK for the next packet.  */
 203                        if (asoc->peer.sack_cnt >= trans->sackfreq - 1)
 204                                asoc->peer.sack_needed = 1;
 205
 206                        asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
 207                                trans->sackdelay;
 208                } else {
 209                        /* We will need a SACK for the next packet.  */
 210                        if (asoc->peer.sack_cnt >= asoc->sackfreq - 1)
 211                                asoc->peer.sack_needed = 1;
 212
 213                        asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
 214                                asoc->sackdelay;
 215                }
 216
 217                /* Restart the SACK timer. */
 218                sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
 219                                SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
 220        } else {
 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/* Handle the timeout of the ICMP protocol unreachable timer.  Trigger
 401 * the correct state machine transition that will close the association.
 402 */
 403void sctp_generate_proto_unreach_event(unsigned long data)
 404{
 405        struct sctp_transport *transport = (struct sctp_transport *) data;
 406        struct sctp_association *asoc = transport->asoc;
 407        
 408        sctp_bh_lock_sock(asoc->base.sk);
 409        if (sock_owned_by_user(asoc->base.sk)) {
 410                SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __func__);
 411
 412                /* Try again later.  */
 413                if (!mod_timer(&transport->proto_unreach_timer,
 414                                jiffies + (HZ/20)))
 415                        sctp_association_hold(asoc);
 416                goto out_unlock;
 417        }
 418
 419        /* Is this structure just waiting around for us to actually
 420         * get destroyed?
 421         */
 422        if (asoc->base.dead)
 423                goto out_unlock;
 424
 425        sctp_do_sm(SCTP_EVENT_T_OTHER,
 426                   SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH),
 427                   asoc->state, asoc->ep, asoc, transport, GFP_ATOMIC);
 428
 429out_unlock:
 430        sctp_bh_unlock_sock(asoc->base.sk);
 431        sctp_association_put(asoc);
 432}
 433
 434
 435/* Inject a SACK Timeout event into the state machine.  */
 436static void sctp_generate_sack_event(unsigned long data)
 437{
 438        struct sctp_association *asoc = (struct sctp_association *) data;
 439        sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
 440}
 441
 442sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
 443        NULL,
 444        sctp_generate_t1_cookie_event,
 445        sctp_generate_t1_init_event,
 446        sctp_generate_t2_shutdown_event,
 447        NULL,
 448        sctp_generate_t4_rto_event,
 449        sctp_generate_t5_shutdown_guard_event,
 450        NULL,
 451        sctp_generate_sack_event,
 452        sctp_generate_autoclose_event,
 453};
 454
 455
 456/* RFC 2960 8.2 Path Failure Detection
 457 *
 458 * When its peer endpoint is multi-homed, an endpoint should keep a
 459 * error counter for each of the destination transport addresses of the
 460 * peer endpoint.
 461 *
 462 * Each time the T3-rtx timer expires on any address, or when a
 463 * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
 464 * the error counter of that destination address will be incremented.
 465 * When the value in the error counter exceeds the protocol parameter
 466 * 'Path.Max.Retrans' of that destination address, the endpoint should
 467 * mark the destination transport address as inactive, and a
 468 * notification SHOULD be sent to the upper layer.
 469 *
 470 */
 471static void sctp_do_8_2_transport_strike(struct sctp_association *asoc,
 472                                         struct sctp_transport *transport,
 473                                         int is_hb)
 474{
 475        /* The check for association's overall error counter exceeding the
 476         * threshold is done in the state function.
 477         */
 478        /* We are here due to a timer expiration.  If the timer was
 479         * not a HEARTBEAT, then normal error tracking is done.
 480         * If the timer was a heartbeat, we only increment error counts
 481         * when we already have an outstanding HEARTBEAT that has not
 482         * been acknowledged.
 483         * Additionaly, some tranport states inhibit error increments.
 484         */
 485        if (!is_hb) {
 486                asoc->overall_error_count++;
 487                if (transport->state != SCTP_INACTIVE)
 488                        transport->error_count++;
 489         } else if (transport->hb_sent) {
 490                if (transport->state != SCTP_UNCONFIRMED)
 491                        asoc->overall_error_count++;
 492                if (transport->state != SCTP_INACTIVE)
 493                        transport->error_count++;
 494        }
 495
 496        if (transport->state != SCTP_INACTIVE &&
 497            (transport->error_count > transport->pathmaxrxt)) {
 498                SCTP_DEBUG_PRINTK_IPADDR("transport_strike:association %p",
 499                                         " transport IP: port:%d failed.\n",
 500                                         asoc,
 501                                         (&transport->ipaddr),
 502                                         ntohs(transport->ipaddr.v4.sin_port));
 503                sctp_assoc_control_transport(asoc, transport,
 504                                             SCTP_TRANSPORT_DOWN,
 505                                             SCTP_FAILED_THRESHOLD);
 506        }
 507
 508        /* E2) For the destination address for which the timer
 509         * expires, set RTO <- RTO * 2 ("back off the timer").  The
 510         * maximum value discussed in rule C7 above (RTO.max) may be
 511         * used to provide an upper bound to this doubling operation.
 512         *
 513         * Special Case:  the first HB doesn't trigger exponential backoff.
 514         * The first unacknowledged HB triggers it.  We do this with a flag
 515         * that indicates that we have an outstanding HB.
 516         */
 517        if (!is_hb || transport->hb_sent) {
 518                transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
 519        }
 520}
 521
 522/* Worker routine to handle INIT command failure.  */
 523static void sctp_cmd_init_failed(sctp_cmd_seq_t *commands,
 524                                 struct sctp_association *asoc,
 525                                 unsigned error)
 526{
 527        struct sctp_ulpevent *event;
 528
 529        event = sctp_ulpevent_make_assoc_change(asoc,0, SCTP_CANT_STR_ASSOC,
 530                                                (__u16)error, 0, 0, NULL,
 531                                                GFP_ATOMIC);
 532
 533        if (event)
 534                sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 535                                SCTP_ULPEVENT(event));
 536
 537        sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 538                        SCTP_STATE(SCTP_STATE_CLOSED));
 539
 540        /* SEND_FAILED sent later when cleaning up the association. */
 541        asoc->outqueue.error = error;
 542        sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 543}
 544
 545/* Worker routine to handle SCTP_CMD_ASSOC_FAILED.  */
 546static void sctp_cmd_assoc_failed(sctp_cmd_seq_t *commands,
 547                                  struct sctp_association *asoc,
 548                                  sctp_event_t event_type,
 549                                  sctp_subtype_t subtype,
 550                                  struct sctp_chunk *chunk,
 551                                  unsigned error)
 552{
 553        struct sctp_ulpevent *event;
 554
 555        /* Cancel any partial delivery in progress. */
 556        sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
 557
 558        if (event_type == SCTP_EVENT_T_CHUNK && subtype.chunk == SCTP_CID_ABORT)
 559                event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
 560                                                (__u16)error, 0, 0, chunk,
 561                                                GFP_ATOMIC);
 562        else
 563                event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
 564                                                (__u16)error, 0, 0, NULL,
 565                                                GFP_ATOMIC);
 566        if (event)
 567                sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 568                                SCTP_ULPEVENT(event));
 569
 570        sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 571                        SCTP_STATE(SCTP_STATE_CLOSED));
 572
 573        /* SEND_FAILED sent later when cleaning up the association. */
 574        asoc->outqueue.error = error;
 575        sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 576}
 577
 578/* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
 579 * inside the cookie.  In reality, this is only used for INIT-ACK processing
 580 * since all other cases use "temporary" associations and can do all
 581 * their work in statefuns directly.
 582 */
 583static int sctp_cmd_process_init(sctp_cmd_seq_t *commands,
 584                                 struct sctp_association *asoc,
 585                                 struct sctp_chunk *chunk,
 586                                 sctp_init_chunk_t *peer_init,
 587                                 gfp_t gfp)
 588{
 589        int error;
 590
 591        /* We only process the init as a sideeffect in a single
 592         * case.   This is when we process the INIT-ACK.   If we
 593         * fail during INIT processing (due to malloc problems),
 594         * just return the error and stop processing the stack.
 595         */
 596        if (!sctp_process_init(asoc, chunk->chunk_hdr->type,
 597                               sctp_source(chunk), peer_init, gfp))
 598                error = -ENOMEM;
 599        else
 600                error = 0;
 601
 602        return error;
 603}
 604
 605/* Helper function to break out starting up of heartbeat timers.  */
 606static void sctp_cmd_hb_timers_start(sctp_cmd_seq_t *cmds,
 607                                     struct sctp_association *asoc)
 608{
 609        struct sctp_transport *t;
 610
 611        /* Start a heartbeat timer for each transport on the association.
 612         * hold a reference on the transport to make sure none of
 613         * the needed data structures go away.
 614         */
 615        list_for_each_entry(t, &asoc->peer.transport_addr_list, transports) {
 616
 617                if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 618                        sctp_transport_hold(t);
 619        }
 620}
 621
 622static void sctp_cmd_hb_timers_stop(sctp_cmd_seq_t *cmds,
 623                                    struct sctp_association *asoc)
 624{
 625        struct sctp_transport *t;
 626
 627        /* Stop all heartbeat timers. */
 628
 629        list_for_each_entry(t, &asoc->peer.transport_addr_list,
 630                        transports) {
 631                if (del_timer(&t->hb_timer))
 632                        sctp_transport_put(t);
 633        }
 634}
 635
 636/* Helper function to stop any pending T3-RTX timers */
 637static void sctp_cmd_t3_rtx_timers_stop(sctp_cmd_seq_t *cmds,
 638                                        struct sctp_association *asoc)
 639{
 640        struct sctp_transport *t;
 641
 642        list_for_each_entry(t, &asoc->peer.transport_addr_list,
 643                        transports) {
 644                if (timer_pending(&t->T3_rtx_timer) &&
 645                    del_timer(&t->T3_rtx_timer)) {
 646                        sctp_transport_put(t);
 647                }
 648        }
 649}
 650
 651
 652/* Helper function to update the heartbeat timer. */
 653static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
 654                                     struct sctp_transport *t)
 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/* Helper function to handle the reception of an HEARTBEAT ACK.  */
 662static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds,
 663                                  struct sctp_association *asoc,
 664                                  struct sctp_transport *t,
 665                                  struct sctp_chunk *chunk)
 666{
 667        sctp_sender_hb_info_t *hbinfo;
 668
 669        /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
 670         * HEARTBEAT should clear the error counter of the destination
 671         * transport address to which the HEARTBEAT was sent.
 672         * The association's overall error count is also cleared.
 673         */
 674        t->error_count = 0;
 675        t->asoc->overall_error_count = 0;
 676
 677        /* Clear the hb_sent flag to signal that we had a good
 678         * acknowledgement.
 679         */
 680        t->hb_sent = 0;
 681
 682        /* Mark the destination transport address as active if it is not so
 683         * marked.
 684         */
 685        if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED))
 686                sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
 687                                             SCTP_HEARTBEAT_SUCCESS);
 688
 689        /* The receiver of the HEARTBEAT ACK should also perform an
 690         * RTT measurement for that destination transport address
 691         * using the time value carried in the HEARTBEAT ACK chunk.
 692         * If the transport's rto_pending variable has been cleared,
 693         * it was most likely due to a retransmit.  However, we want
 694         * to re-enable it to properly update the rto.
 695         */
 696        if (t->rto_pending == 0)
 697                t->rto_pending = 1;
 698
 699        hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
 700        sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
 701
 702        /* Update the heartbeat timer.  */
 703        if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 704                sctp_transport_hold(t);
 705}
 706
 707
 708/* Helper function to process the process SACK command.  */
 709static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds,
 710                                 struct sctp_association *asoc,
 711                                 struct sctp_sackhdr *sackh)
 712{
 713        int err = 0;
 714
 715        if (sctp_outq_sack(&asoc->outqueue, sackh)) {
 716                /* There are no more TSNs awaiting SACK.  */
 717                err = sctp_do_sm(SCTP_EVENT_T_OTHER,
 718                                 SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
 719                                 asoc->state, asoc->ep, asoc, NULL,
 720                                 GFP_ATOMIC);
 721        }
 722
 723        return err;
 724}
 725
 726/* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
 727 * the transport for a shutdown chunk.
 728 */
 729static void sctp_cmd_setup_t2(sctp_cmd_seq_t *cmds,
 730                              struct sctp_association *asoc,
 731                              struct sctp_chunk *chunk)
 732{
 733        struct sctp_transport *t;
 734
 735        if (chunk->transport)
 736                t = chunk->transport;
 737        else {
 738                t = sctp_assoc_choose_alter_transport(asoc,
 739                                              asoc->shutdown_last_sent_to);
 740                chunk->transport = t;
 741        }
 742        asoc->shutdown_last_sent_to = t;
 743        asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
 744}
 745
 746/* Helper function to change the state of an association. */
 747static void sctp_cmd_new_state(sctp_cmd_seq_t *cmds,
 748                               struct sctp_association *asoc,
 749                               sctp_state_t state)
 750{
 751        struct sock *sk = asoc->base.sk;
 752
 753        asoc->state = state;
 754
 755        SCTP_DEBUG_PRINTK("sctp_cmd_new_state: asoc %p[%s]\n",
 756                          asoc, sctp_state_tbl[state]);
 757
 758        if (sctp_style(sk, TCP)) {
 759                /* Change the sk->sk_state of a TCP-style socket that has
 760                 * successfully completed a connect() call.
 761                 */
 762                if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
 763                        sk->sk_state = SCTP_SS_ESTABLISHED;
 764
 765                /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
 766                if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
 767                    sctp_sstate(sk, ESTABLISHED))
 768                        sk->sk_shutdown |= RCV_SHUTDOWN;
 769        }
 770
 771        if (sctp_state(asoc, COOKIE_WAIT)) {
 772                /* Reset init timeouts since they may have been
 773                 * increased due to timer expirations.
 774                 */
 775                asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
 776                                                asoc->rto_initial;
 777                asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
 778                                                asoc->rto_initial;
 779        }
 780
 781        if (sctp_state(asoc, ESTABLISHED) ||
 782            sctp_state(asoc, CLOSED) ||
 783            sctp_state(asoc, SHUTDOWN_RECEIVED)) {
 784                /* Wake up any processes waiting in the asoc's wait queue in
 785                 * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
 786                 */
 787                if (waitqueue_active(&asoc->wait))
 788                        wake_up_interruptible(&asoc->wait);
 789
 790                /* Wake up any processes waiting in the sk's sleep queue of
 791                 * a TCP-style or UDP-style peeled-off socket in
 792                 * sctp_wait_for_accept() or sctp_wait_for_packet().
 793                 * For a UDP-style socket, the waiters are woken up by the
 794                 * notifications.
 795                 */
 796                if (!sctp_style(sk, UDP))
 797                        sk->sk_state_change(sk);
 798        }
 799}
 800
 801/* Helper function to delete an association. */
 802static void sctp_cmd_delete_tcb(sctp_cmd_seq_t *cmds,
 803                                struct sctp_association *asoc)
 804{
 805        struct sock *sk = asoc->base.sk;
 806
 807        /* If it is a non-temporary association belonging to a TCP-style
 808         * listening socket that is not closed, do not free it so that accept()
 809         * can pick it up later.
 810         */
 811        if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
 812            (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
 813                return;
 814
 815        sctp_unhash_established(asoc);
 816        sctp_association_free(asoc);
 817}
 818
 819/*
 820 * ADDIP Section 4.1 ASCONF Chunk Procedures
 821 * A4) Start a T-4 RTO timer, using the RTO value of the selected
 822 * destination address (we use active path instead of primary path just
 823 * because primary path may be inactive.
 824 */
 825static void sctp_cmd_setup_t4(sctp_cmd_seq_t *cmds,
 826                                struct sctp_association *asoc,
 827                                struct sctp_chunk *chunk)
 828{
 829        struct sctp_transport *t;
 830
 831        t = sctp_assoc_choose_alter_transport(asoc, chunk->transport);
 832        asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
 833        chunk->transport = t;
 834}
 835
 836/* Process an incoming Operation Error Chunk. */
 837static void sctp_cmd_process_operr(sctp_cmd_seq_t *cmds,
 838                                   struct sctp_association *asoc,
 839                                   struct sctp_chunk *chunk)
 840{
 841        struct sctp_errhdr *err_hdr;
 842        struct sctp_ulpevent *ev;
 843
 844        while (chunk->chunk_end > chunk->skb->data) {
 845                err_hdr = (struct sctp_errhdr *)(chunk->skb->data);
 846
 847                ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
 848                                                     GFP_ATOMIC);
 849                if (!ev)
 850                        return;
 851
 852                sctp_ulpq_tail_event(&asoc->ulpq, ev);
 853
 854                switch (err_hdr->cause) {
 855                case SCTP_ERROR_UNKNOWN_CHUNK:
 856                {
 857                        sctp_chunkhdr_t *unk_chunk_hdr;
 858
 859                        unk_chunk_hdr = (sctp_chunkhdr_t *)err_hdr->variable;
 860                        switch (unk_chunk_hdr->type) {
 861                        /* ADDIP 4.1 A9) If the peer responds to an ASCONF with
 862                         * an ERROR chunk reporting that it did not recognized
 863                         * the ASCONF chunk type, the sender of the ASCONF MUST
 864                         * NOT send any further ASCONF chunks and MUST stop its
 865                         * T-4 timer.
 866                         */
 867                        case SCTP_CID_ASCONF:
 868                                if (asoc->peer.asconf_capable == 0)
 869                                        break;
 870
 871                                asoc->peer.asconf_capable = 0;
 872                                sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
 873                                        SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
 874                                break;
 875                        default:
 876                                break;
 877                        }
 878                        break;
 879                }
 880                default:
 881                        break;
 882                }
 883        }
 884}
 885
 886/* Process variable FWDTSN chunk information. */
 887static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq,
 888                                    struct sctp_chunk *chunk)
 889{
 890        struct sctp_fwdtsn_skip *skip;
 891        /* Walk through all the skipped SSNs */
 892        sctp_walk_fwdtsn(skip, chunk) {
 893                sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
 894        }
 895}
 896
 897/* Helper function to remove the association non-primary peer
 898 * transports.
 899 */
 900static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
 901{
 902        struct sctp_transport *t;
 903        struct list_head *pos;
 904        struct list_head *temp;
 905
 906        list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
 907                t = list_entry(pos, struct sctp_transport, transports);
 908                if (!sctp_cmp_addr_exact(&t->ipaddr,
 909                                         &asoc->peer.primary_addr)) {
 910                        sctp_assoc_del_peer(asoc, &t->ipaddr);
 911                }
 912        }
 913}
 914
 915/* Helper function to set sk_err on a 1-1 style socket. */
 916static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
 917{
 918        struct sock *sk = asoc->base.sk;
 919
 920        if (!sctp_style(sk, UDP))
 921                sk->sk_err = error;
 922}
 923
 924/* Helper function to generate an association change event */
 925static void sctp_cmd_assoc_change(sctp_cmd_seq_t *commands,
 926                                 struct sctp_association *asoc,
 927                                 u8 state)
 928{
 929        struct sctp_ulpevent *ev;
 930
 931        ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0,
 932                                            asoc->c.sinit_num_ostreams,
 933                                            asoc->c.sinit_max_instreams,
 934                                            NULL, GFP_ATOMIC);
 935        if (ev)
 936                sctp_ulpq_tail_event(&asoc->ulpq, ev);
 937}
 938
 939/* Helper function to generate an adaptation indication event */
 940static void sctp_cmd_adaptation_ind(sctp_cmd_seq_t *commands,
 941                                    struct sctp_association *asoc)
 942{
 943        struct sctp_ulpevent *ev;
 944
 945        ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
 946
 947        if (ev)
 948                sctp_ulpq_tail_event(&asoc->ulpq, ev);
 949}
 950
 951
 952static void sctp_cmd_t1_timer_update(struct sctp_association *asoc,
 953                                    sctp_event_timeout_t timer,
 954                                    char *name)
 955{
 956        struct sctp_transport *t;
 957
 958        t = asoc->init_last_sent_to;
 959        asoc->init_err_counter++;
 960
 961        if (t->init_sent_count > (asoc->init_cycle + 1)) {
 962                asoc->timeouts[timer] *= 2;
 963                if (asoc->timeouts[timer] > asoc->max_init_timeo) {
 964                        asoc->timeouts[timer] = asoc->max_init_timeo;
 965                }
 966                asoc->init_cycle++;
 967                SCTP_DEBUG_PRINTK(
 968                        "T1 %s Timeout adjustment"
 969                        " init_err_counter: %d"
 970                        " cycle: %d"
 971                        " timeout: %ld\n",
 972                        name,
 973                        asoc->init_err_counter,
 974                        asoc->init_cycle,
 975                        asoc->timeouts[timer]);
 976        }
 977
 978}
 979
 980/* Send the whole message, chunk by chunk, to the outqueue.
 981 * This way the whole message is queued up and bundling if
 982 * encouraged for small fragments.
 983 */
 984static int sctp_cmd_send_msg(struct sctp_association *asoc,
 985                                struct sctp_datamsg *msg)
 986{
 987        struct sctp_chunk *chunk;
 988        int error = 0;
 989
 990        list_for_each_entry(chunk, &msg->chunks, frag_list) {
 991                error = sctp_outq_tail(&asoc->outqueue, chunk);
 992                if (error)
 993                        break;
 994        }
 995
 996        return error;
 997}
 998
 999
1000/* Sent the next ASCONF packet currently stored in the association.
1001 * This happens after the ASCONF_ACK was succeffully processed.
1002 */
1003static void sctp_cmd_send_asconf(struct sctp_association *asoc)
1004{
1005        /* Send the next asconf chunk from the addip chunk
1006         * queue.
1007         */
1008        if (!list_empty(&asoc->addip_chunk_list)) {
1009                struct list_head *entry = asoc->addip_chunk_list.next;
1010                struct sctp_chunk *asconf = list_entry(entry,
1011                                                struct sctp_chunk, list);
1012                list_del_init(entry);
1013
1014                /* Hold the chunk until an ASCONF_ACK is received. */
1015                sctp_chunk_hold(asconf);
1016                if (sctp_primitive_ASCONF(asoc, asconf))
1017                        sctp_chunk_free(asconf);
1018                else
1019                        asoc->addip_last_asconf = asconf;
1020        }
1021}
1022
1023
1024/* These three macros allow us to pull the debugging code out of the
1025 * main flow of sctp_do_sm() to keep attention focused on the real
1026 * functionality there.
1027 */
1028#define DEBUG_PRE \
1029        SCTP_DEBUG_PRINTK("sctp_do_sm prefn: " \
1030                          "ep %p, %s, %s, asoc %p[%s], %s\n", \
1031                          ep, sctp_evttype_tbl[event_type], \
1032                          (*debug_fn)(subtype), asoc, \
1033                          sctp_state_tbl[state], state_fn->name)
1034
1035#define DEBUG_POST \
1036        SCTP_DEBUG_PRINTK("sctp_do_sm postfn: " \
1037                          "asoc %p, status: %s\n", \
1038                          asoc, sctp_status_tbl[status])
1039
1040#define DEBUG_POST_SFX \
1041        SCTP_DEBUG_PRINTK("sctp_do_sm post sfx: error %d, asoc %p[%s]\n", \
1042                          error, asoc, \
1043                          sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
1044                          sctp_assoc2id(asoc)))?asoc->state:SCTP_STATE_CLOSED])
1045
1046/*
1047 * This is the master state machine processing function.
1048 *
1049 * If you want to understand all of lksctp, this is a
1050 * good place to start.
1051 */
1052int sctp_do_sm(sctp_event_t event_type, sctp_subtype_t subtype,
1053               sctp_state_t state,
1054               struct sctp_endpoint *ep,
1055               struct sctp_association *asoc,
1056               void *event_arg,
1057               gfp_t gfp)
1058{
1059        sctp_cmd_seq_t commands;
1060        const sctp_sm_table_entry_t *state_fn;
1061        sctp_disposition_t status;
1062        int error = 0;
1063        typedef const char *(printfn_t)(sctp_subtype_t);
1064
1065        static printfn_t *table[] = {
1066                NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
1067        };
1068        printfn_t *debug_fn  __attribute__ ((unused)) = table[event_type];
1069
1070        /* Look up the state function, run it, and then process the
1071         * side effects.  These three steps are the heart of lksctp.
1072         */
1073        state_fn = sctp_sm_lookup_event(event_type, state, subtype);
1074
1075        sctp_init_cmd_seq(&commands);
1076
1077        DEBUG_PRE;
1078        status = (*state_fn->fn)(ep, asoc, subtype, event_arg, &commands);
1079        DEBUG_POST;
1080
1081        error = sctp_side_effects(event_type, subtype, state,
1082                                  ep, asoc, event_arg, status,
1083                                  &commands, gfp);
1084        DEBUG_POST_SFX;
1085
1086        return error;
1087}
1088
1089#undef DEBUG_PRE
1090#undef DEBUG_POST
1091
1092/*****************************************************************
1093 * This the master state function side effect processing function.
1094 *****************************************************************/
1095static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
1096                             sctp_state_t state,
1097                             struct sctp_endpoint *ep,
1098                             struct sctp_association *asoc,
1099                             void *event_arg,
1100                             sctp_disposition_t status,
1101                             sctp_cmd_seq_t *commands,
1102                             gfp_t gfp)
1103{
1104        int error;
1105
1106        /* FIXME - Most of the dispositions left today would be categorized
1107         * as "exceptional" dispositions.  For those dispositions, it
1108         * may not be proper to run through any of the commands at all.
1109         * For example, the command interpreter might be run only with
1110         * disposition SCTP_DISPOSITION_CONSUME.
1111         */
1112        if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
1113                                               ep, asoc,
1114                                               event_arg, status,
1115                                               commands, gfp)))
1116                goto bail;
1117
1118        switch (status) {
1119        case SCTP_DISPOSITION_DISCARD:
1120                SCTP_DEBUG_PRINTK("Ignored sctp protocol event - state %d, "
1121                                  "event_type %d, event_id %d\n",
1122                                  state, event_type, subtype.chunk);
1123                break;
1124
1125        case SCTP_DISPOSITION_NOMEM:
1126                /* We ran out of memory, so we need to discard this
1127                 * packet.
1128                 */
1129                /* BUG--we should now recover some memory, probably by
1130                 * reneging...
1131                 */
1132                error = -ENOMEM;
1133                break;
1134
1135        case SCTP_DISPOSITION_DELETE_TCB:
1136                /* This should now be a command. */
1137                break;
1138
1139        case SCTP_DISPOSITION_CONSUME:
1140        case SCTP_DISPOSITION_ABORT:
1141                /*
1142                 * We should no longer have much work to do here as the
1143                 * real work has been done as explicit commands above.
1144                 */
1145                break;
1146
1147        case SCTP_DISPOSITION_VIOLATION:
1148                if (net_ratelimit())
1149                        printk(KERN_ERR "sctp protocol violation state %d "
1150                               "chunkid %d\n", state, subtype.chunk);
1151                break;
1152
1153        case SCTP_DISPOSITION_NOT_IMPL:
1154                printk(KERN_WARNING "sctp unimplemented feature in state %d, "
1155                       "event_type %d, event_id %d\n",
1156                       state, event_type, subtype.chunk);
1157                break;
1158
1159        case SCTP_DISPOSITION_BUG:
1160                printk(KERN_ERR "sctp bug in state %d, "
1161                       "event_type %d, event_id %d\n",
1162                       state, event_type, subtype.chunk);
1163                BUG();
1164                break;
1165
1166        default:
1167                printk(KERN_ERR "sctp impossible disposition %d "
1168                       "in state %d, event_type %d, event_id %d\n",
1169                       status, state, event_type, subtype.chunk);
1170                BUG();
1171                break;
1172        }
1173
1174bail:
1175        return error;
1176}
1177
1178/********************************************************************
1179 * 2nd Level Abstractions
1180 ********************************************************************/
1181
1182/* This is the side-effect interpreter.  */
1183static int sctp_cmd_interpreter(sctp_event_t event_type,
1184                                sctp_subtype_t subtype,
1185                                sctp_state_t state,
1186                                struct sctp_endpoint *ep,
1187                                struct sctp_association *asoc,
1188                                void *event_arg,
1189                                sctp_disposition_t status,
1190                                sctp_cmd_seq_t *commands,
1191                                gfp_t gfp)
1192{
1193        int error = 0;
1194        int force;
1195        sctp_cmd_t *cmd;
1196        struct sctp_chunk *new_obj;
1197        struct sctp_chunk *chunk = NULL;
1198        struct sctp_packet *packet;
1199        struct timer_list *timer;
1200        unsigned long timeout;
1201        struct sctp_transport *t;
1202        struct sctp_sackhdr sackh;
1203        int local_cork = 0;
1204
1205        if (SCTP_EVENT_T_TIMEOUT != event_type)
1206                chunk = (struct sctp_chunk *) event_arg;
1207
1208        /* Note:  This whole file is a huge candidate for rework.
1209         * For example, each command could either have its own handler, so
1210         * the loop would look like:
1211         *     while (cmds)
1212         *         cmd->handle(x, y, z)
1213         * --jgrimm
1214         */
1215        while (NULL != (cmd = sctp_next_cmd(commands))) {
1216                switch (cmd->verb) {
1217                case SCTP_CMD_NOP:
1218                        /* Do nothing. */
1219                        break;
1220
1221                case SCTP_CMD_NEW_ASOC:
1222                        /* Register a new association.  */
1223                        if (local_cork) {
1224                                sctp_outq_uncork(&asoc->outqueue);
1225                                local_cork = 0;
1226                        }
1227                        asoc = cmd->obj.ptr;
1228                        /* Register with the endpoint.  */
1229                        sctp_endpoint_add_asoc(ep, asoc);
1230                        sctp_hash_established(asoc);
1231                        break;
1232
1233                case SCTP_CMD_UPDATE_ASSOC:
1234                       sctp_assoc_update(asoc, cmd->obj.ptr);
1235                       break;
1236
1237                case SCTP_CMD_PURGE_OUTQUEUE:
1238                       sctp_outq_teardown(&asoc->outqueue);
1239                       break;
1240
1241                case SCTP_CMD_DELETE_TCB:
1242                        if (local_cork) {
1243                                sctp_outq_uncork(&asoc->outqueue);
1244                                local_cork = 0;
1245                        }
1246                        /* Delete the current association.  */
1247                        sctp_cmd_delete_tcb(commands, asoc);
1248                        asoc = NULL;
1249                        break;
1250
1251                case SCTP_CMD_NEW_STATE:
1252                        /* Enter a new state.  */
1253                        sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1254                        break;
1255
1256                case SCTP_CMD_REPORT_TSN:
1257                        /* Record the arrival of a TSN.  */
1258                        error = sctp_tsnmap_mark(&asoc->peer.tsn_map,
1259                                                 cmd->obj.u32);
1260                        break;
1261
1262                case SCTP_CMD_REPORT_FWDTSN:
1263                        /* Move the Cumulattive TSN Ack ahead. */
1264                        sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32);
1265
1266                        /* purge the fragmentation queue */
1267                        sctp_ulpq_reasm_flushtsn(&asoc->ulpq, cmd->obj.u32);
1268
1269                        /* Abort any in progress partial delivery. */
1270                        sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
1271                        break;
1272
1273                case SCTP_CMD_PROCESS_FWDTSN:
1274                        sctp_cmd_process_fwdtsn(&asoc->ulpq, cmd->obj.ptr);
1275                        break;
1276
1277                case SCTP_CMD_GEN_SACK:
1278                        /* Generate a Selective ACK.
1279                         * The argument tells us whether to just count
1280                         * the packet and MAYBE generate a SACK, or
1281                         * force a SACK out.
1282                         */
1283                        force = cmd->obj.i32;
1284                        error = sctp_gen_sack(asoc, force, commands);
1285                        break;
1286
1287                case SCTP_CMD_PROCESS_SACK:
1288                        /* Process an inbound SACK.  */
1289                        error = sctp_cmd_process_sack(commands, asoc,
1290                                                      cmd->obj.ptr);
1291                        break;
1292
1293                case SCTP_CMD_GEN_INIT_ACK:
1294                        /* Generate an INIT ACK chunk.  */
1295                        new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1296                                                     0);
1297                        if (!new_obj)
1298                                goto nomem;
1299
1300                        sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1301                                        SCTP_CHUNK(new_obj));
1302                        break;
1303
1304                case SCTP_CMD_PEER_INIT:
1305                        /* Process a unified INIT from the peer.
1306                         * Note: Only used during INIT-ACK processing.  If
1307                         * there is an error just return to the outter
1308                         * layer which will bail.
1309                         */
1310                        error = sctp_cmd_process_init(commands, asoc, chunk,
1311                                                      cmd->obj.ptr, gfp);
1312                        break;
1313
1314                case SCTP_CMD_GEN_COOKIE_ECHO:
1315                        /* Generate a COOKIE ECHO chunk.  */
1316                        new_obj = sctp_make_cookie_echo(asoc, chunk);
1317                        if (!new_obj) {
1318                                if (cmd->obj.ptr)
1319                                        sctp_chunk_free(cmd->obj.ptr);
1320                                goto nomem;
1321                        }
1322                        sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1323                                        SCTP_CHUNK(new_obj));
1324
1325                        /* If there is an ERROR chunk to be sent along with
1326                         * the COOKIE_ECHO, send it, too.
1327                         */
1328                        if (cmd->obj.ptr)
1329                                sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1330                                                SCTP_CHUNK(cmd->obj.ptr));
1331
1332                        if (new_obj->transport) {
1333                                new_obj->transport->init_sent_count++;
1334                                asoc->init_last_sent_to = new_obj->transport;
1335                        }
1336
1337                        /* FIXME - Eventually come up with a cleaner way to
1338                         * enabling COOKIE-ECHO + DATA bundling during
1339                         * multihoming stale cookie scenarios, the following
1340                         * command plays with asoc->peer.retran_path to
1341                         * avoid the problem of sending the COOKIE-ECHO and
1342                         * DATA in different paths, which could result
1343                         * in the association being ABORTed if the DATA chunk
1344                         * is processed first by the server.  Checking the
1345                         * init error counter simply causes this command
1346                         * to be executed only during failed attempts of
1347                         * association establishment.
1348                         */
1349                        if ((asoc->peer.retran_path !=
1350                             asoc->peer.primary_path) &&
1351                            (asoc->init_err_counter > 0)) {
1352                                sctp_add_cmd_sf(commands,
1353                                                SCTP_CMD_FORCE_PRIM_RETRAN,
1354                                                SCTP_NULL());
1355                        }
1356
1357                        break;
1358
1359                case SCTP_CMD_GEN_SHUTDOWN:
1360                        /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1361                         * Reset error counts.
1362                         */
1363                        asoc->overall_error_count = 0;
1364
1365                        /* Generate a SHUTDOWN chunk.  */
1366                        new_obj = sctp_make_shutdown(asoc, chunk);
1367                        if (!new_obj)
1368                                goto nomem;
1369                        sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1370                                        SCTP_CHUNK(new_obj));
1371                        break;
1372
1373                case SCTP_CMD_CHUNK_ULP:
1374                        /* Send a chunk to the sockets layer.  */
1375                        SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1376                                          "chunk_up:", cmd->obj.ptr,
1377                                          "ulpq:", &asoc->ulpq);
1378                        sctp_ulpq_tail_data(&asoc->ulpq, cmd->obj.ptr,
1379                                            GFP_ATOMIC);
1380                        break;
1381
1382                case SCTP_CMD_EVENT_ULP:
1383                        /* Send a notification to the sockets layer.  */
1384                        SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1385                                          "event_up:",cmd->obj.ptr,
1386                                          "ulpq:",&asoc->ulpq);
1387                        sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ptr);
1388                        break;
1389
1390                case SCTP_CMD_REPLY:
1391                        /* If an caller has not already corked, do cork. */
1392                        if (!asoc->outqueue.cork) {
1393                                sctp_outq_cork(&asoc->outqueue);
1394                                local_cork = 1;
1395                        }
1396                        /* Send a chunk to our peer.  */
1397                        error = sctp_outq_tail(&asoc->outqueue, cmd->obj.ptr);
1398                        break;
1399
1400                case SCTP_CMD_SEND_PKT:
1401                        /* Send a full packet to our peer.  */
1402                        packet = cmd->obj.ptr;
1403                        sctp_packet_transmit(packet);
1404                        sctp_ootb_pkt_free(packet);
1405                        break;
1406
1407                case SCTP_CMD_T1_RETRAN:
1408                        /* Mark a transport for retransmission.  */
1409                        sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1410                                        SCTP_RTXR_T1_RTX);
1411                        break;
1412
1413                case SCTP_CMD_RETRAN:
1414                        /* Mark a transport for retransmission.  */
1415                        sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1416                                        SCTP_RTXR_T3_RTX);
1417                        break;
1418
1419                case SCTP_CMD_TRANSMIT:
1420                        /* Kick start transmission. */
1421                        error = sctp_outq_uncork(&asoc->outqueue);
1422                        local_cork = 0;
1423                        break;
1424
1425                case SCTP_CMD_ECN_CE:
1426                        /* Do delayed CE processing.   */
1427                        sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1428                        break;
1429
1430                case SCTP_CMD_ECN_ECNE:
1431                        /* Do delayed ECNE processing. */
1432                        new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1433                                                        chunk);
1434                        if (new_obj)
1435                                sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1436                                                SCTP_CHUNK(new_obj));
1437                        break;
1438
1439                case SCTP_CMD_ECN_CWR:
1440                        /* Do delayed CWR processing.  */
1441                        sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1442                        break;
1443
1444                case SCTP_CMD_SETUP_T2:
1445                        sctp_cmd_setup_t2(commands, asoc, cmd->obj.ptr);
1446                        break;
1447
1448                case SCTP_CMD_TIMER_START:
1449                        timer = &asoc->timers[cmd->obj.to];
1450                        timeout = asoc->timeouts[cmd->obj.to];
1451                        BUG_ON(!timeout);
1452
1453                        timer->expires = jiffies + timeout;
1454                        sctp_association_hold(asoc);
1455                        add_timer(timer);
1456                        break;
1457
1458                case SCTP_CMD_TIMER_RESTART:
1459                        timer = &asoc->timers[cmd->obj.to];
1460                        timeout = asoc->timeouts[cmd->obj.to];
1461                        if (!mod_timer(timer, jiffies + timeout))
1462                                sctp_association_hold(asoc);
1463                        break;
1464
1465                case SCTP_CMD_TIMER_STOP:
1466                        timer = &asoc->timers[cmd->obj.to];
1467                        if (timer_pending(timer) && del_timer(timer))
1468                                sctp_association_put(asoc);
1469                        break;
1470
1471                case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1472                        chunk = cmd->obj.ptr;
1473                        t = sctp_assoc_choose_alter_transport(asoc,
1474                                                asoc->init_last_sent_to);
1475                        asoc->init_last_sent_to = t;
1476                        chunk->transport = t;
1477                        t->init_sent_count++;
1478                        /* Set the new transport as primary */
1479                        sctp_assoc_set_primary(asoc, t);
1480                        break;
1481
1482                case SCTP_CMD_INIT_RESTART:
1483                        /* Do the needed accounting and updates
1484                         * associated with restarting an initialization
1485                         * timer. Only multiply the timeout by two if
1486                         * all transports have been tried at the current
1487                         * timeout.
1488                         */
1489                        sctp_cmd_t1_timer_update(asoc,
1490                                                SCTP_EVENT_TIMEOUT_T1_INIT,
1491                                                "INIT");
1492
1493                        sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1494                                        SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1495                        break;
1496
1497                case SCTP_CMD_COOKIEECHO_RESTART:
1498                        /* Do the needed accounting and updates
1499                         * associated with restarting an initialization
1500                         * timer. Only multiply the timeout by two if
1501                         * all transports have been tried at the current
1502                         * timeout.
1503                         */
1504                        sctp_cmd_t1_timer_update(asoc,
1505                                                SCTP_EVENT_TIMEOUT_T1_COOKIE,
1506                                                "COOKIE");
1507
1508                        /* If we've sent any data bundled with
1509                         * COOKIE-ECHO we need to resend.
1510                         */
1511                        list_for_each_entry(t, &asoc->peer.transport_addr_list,
1512                                        transports) {
1513                                sctp_retransmit_mark(&asoc->outqueue, t,
1514                                            SCTP_RTXR_T1_RTX);
1515                        }
1516
1517                        sctp_add_cmd_sf(commands,
1518                                        SCTP_CMD_TIMER_RESTART,
1519                                        SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1520                        break;
1521
1522                case SCTP_CMD_INIT_FAILED:
1523                        sctp_cmd_init_failed(commands, asoc, cmd->obj.err);
1524                        break;
1525
1526                case SCTP_CMD_ASSOC_FAILED:
1527                        sctp_cmd_assoc_failed(commands, asoc, event_type,
1528                                              subtype, chunk, cmd->obj.err);
1529                        break;
1530
1531                case SCTP_CMD_INIT_COUNTER_INC:
1532                        asoc->init_err_counter++;
1533                        break;
1534
1535                case SCTP_CMD_INIT_COUNTER_RESET:
1536                        asoc->init_err_counter = 0;
1537                        asoc->init_cycle = 0;
1538                        list_for_each_entry(t, &asoc->peer.transport_addr_list,
1539                                            transports) {
1540                                t->init_sent_count = 0;
1541                        }
1542                        break;
1543
1544                case SCTP_CMD_REPORT_DUP:
1545                        sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1546                                             cmd->obj.u32);
1547                        break;
1548
1549                case SCTP_CMD_REPORT_BAD_TAG:
1550                        SCTP_DEBUG_PRINTK("vtag mismatch!\n");
1551                        break;
1552
1553                case SCTP_CMD_STRIKE:
1554                        /* Mark one strike against a transport.  */
1555                        sctp_do_8_2_transport_strike(asoc, cmd->obj.transport,
1556                                                    0);
1557                        break;
1558
1559                case SCTP_CMD_TRANSPORT_IDLE:
1560                        t = cmd->obj.transport;
1561                        sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
1562                        break;
1563
1564                case SCTP_CMD_TRANSPORT_HB_SENT:
1565                        t = cmd->obj.transport;
1566                        sctp_do_8_2_transport_strike(asoc, t, 1);
1567                        t->hb_sent = 1;
1568                        break;
1569
1570                case SCTP_CMD_TRANSPORT_ON:
1571                        t = cmd->obj.transport;
1572                        sctp_cmd_transport_on(commands, asoc, t, chunk);
1573                        break;
1574
1575                case SCTP_CMD_HB_TIMERS_START:
1576                        sctp_cmd_hb_timers_start(commands, asoc);
1577                        break;
1578
1579                case SCTP_CMD_HB_TIMER_UPDATE:
1580                        t = cmd->obj.transport;
1581                        sctp_cmd_hb_timer_update(commands, t);
1582                        break;
1583
1584                case SCTP_CMD_HB_TIMERS_STOP:
1585                        sctp_cmd_hb_timers_stop(commands, asoc);
1586                        break;
1587
1588                case SCTP_CMD_REPORT_ERROR:
1589                        error = cmd->obj.error;
1590                        break;
1591
1592                case SCTP_CMD_PROCESS_CTSN:
1593                        /* Dummy up a SACK for processing. */
1594                        sackh.cum_tsn_ack = cmd->obj.be32;
1595                        sackh.a_rwnd = asoc->peer.rwnd +
1596                                        asoc->outqueue.outstanding_bytes;
1597                        sackh.num_gap_ack_blocks = 0;
1598                        sackh.num_dup_tsns = 0;
1599                        sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1600                                        SCTP_SACKH(&sackh));
1601                        break;
1602
1603                case SCTP_CMD_DISCARD_PACKET:
1604                        /* We need to discard the whole packet.
1605                         * Uncork the queue since there might be
1606                         * responses pending
1607                         */
1608                        chunk->pdiscard = 1;
1609                        if (asoc) {
1610                                sctp_outq_uncork(&asoc->outqueue);
1611                                local_cork = 0;
1612                        }
1613                        break;
1614
1615                case SCTP_CMD_RTO_PENDING:
1616                        t = cmd->obj.transport;
1617                        t->rto_pending = 1;
1618                        break;
1619
1620                case SCTP_CMD_PART_DELIVER:
1621                        sctp_ulpq_partial_delivery(&asoc->ulpq, cmd->obj.ptr,
1622                                                   GFP_ATOMIC);
1623                        break;
1624
1625                case SCTP_CMD_RENEGE:
1626                        sctp_ulpq_renege(&asoc->ulpq, cmd->obj.ptr,
1627                                         GFP_ATOMIC);
1628                        break;
1629
1630                case SCTP_CMD_SETUP_T4:
1631                        sctp_cmd_setup_t4(commands, asoc, cmd->obj.ptr);
1632                        break;
1633
1634                case SCTP_CMD_PROCESS_OPERR:
1635                        sctp_cmd_process_operr(commands, asoc, chunk);
1636                        break;
1637                case SCTP_CMD_CLEAR_INIT_TAG:
1638                        asoc->peer.i.init_tag = 0;
1639                        break;
1640                case SCTP_CMD_DEL_NON_PRIMARY:
1641                        sctp_cmd_del_non_primary(asoc);
1642                        break;
1643                case SCTP_CMD_T3_RTX_TIMERS_STOP:
1644                        sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1645                        break;
1646                case SCTP_CMD_FORCE_PRIM_RETRAN:
1647                        t = asoc->peer.retran_path;
1648                        asoc->peer.retran_path = asoc->peer.primary_path;
1649                        error = sctp_outq_uncork(&asoc->outqueue);
1650                        local_cork = 0;
1651                        asoc->peer.retran_path = t;
1652                        break;
1653                case SCTP_CMD_SET_SK_ERR:
1654                        sctp_cmd_set_sk_err(asoc, cmd->obj.error);
1655                        break;
1656                case SCTP_CMD_ASSOC_CHANGE:
1657                        sctp_cmd_assoc_change(commands, asoc,
1658                                              cmd->obj.u8);
1659                        break;
1660                case SCTP_CMD_ADAPTATION_IND:
1661                        sctp_cmd_adaptation_ind(commands, asoc);
1662                        break;
1663
1664                case SCTP_CMD_ASSOC_SHKEY:
1665                        error = sctp_auth_asoc_init_active_key(asoc,
1666                                                GFP_ATOMIC);
1667                        break;
1668                case SCTP_CMD_UPDATE_INITTAG:
1669                        asoc->peer.i.init_tag = cmd->obj.u32;
1670                        break;
1671                case SCTP_CMD_SEND_MSG:
1672                        if (!asoc->outqueue.cork) {
1673                                sctp_outq_cork(&asoc->outqueue);
1674                                local_cork = 1;
1675                        }
1676                        error = sctp_cmd_send_msg(asoc, cmd->obj.msg);
1677                        break;
1678                case SCTP_CMD_SEND_NEXT_ASCONF:
1679                        sctp_cmd_send_asconf(asoc);
1680                        break;
1681                default:
1682                        printk(KERN_WARNING "Impossible command: %u, %p\n",
1683                               cmd->verb, cmd->obj.ptr);
1684                        break;
1685                }
1686
1687                if (error)
1688                        break;
1689        }
1690
1691out:
1692        /* If this is in response to a received chunk, wait until
1693         * we are done with the packet to open the queue so that we don't
1694         * send multiple packets in response to a single request.
1695         */
1696        if (asoc && SCTP_EVENT_T_CHUNK == event_type && chunk) {
1697                if (chunk->end_of_packet || chunk->singleton)
1698                        error = sctp_outq_uncork(&asoc->outqueue);
1699        } else if (local_cork)
1700                error = sctp_outq_uncork(&asoc->outqueue);
1701        return error;
1702nomem:
1703        error = -ENOMEM;
1704        goto out;
1705}
1706
1707