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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  51
  52#include <linux/skbuff.h>
  53#include <linux/types.h>
  54#include <linux/socket.h>
  55#include <linux/ip.h>
  56#include <linux/gfp.h>
  57#include <net/sock.h>
  58#include <net/sctp/sctp.h>
  59#include <net/sctp/sm.h>
  60
  61static int sctp_cmd_interpreter(sctp_event_t event_type,
  62                                sctp_subtype_t subtype,
  63                                sctp_state_t state,
  64                                struct sctp_endpoint *ep,
  65                                struct sctp_association *asoc,
  66                                void *event_arg,
  67                                sctp_disposition_t status,
  68                                sctp_cmd_seq_t *commands,
  69                                gfp_t gfp);
  70static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
  71                             sctp_state_t state,
  72                             struct sctp_endpoint *ep,
  73                             struct sctp_association *asoc,
  74                             void *event_arg,
  75                             sctp_disposition_t status,
  76                             sctp_cmd_seq_t *commands,
  77                             gfp_t gfp);
  78
  79static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
  80                                     struct sctp_transport *t);
  81/********************************************************************
  82 * Helper functions
  83 ********************************************************************/
  84
  85/* A helper function for delayed processing of INET ECN CE bit. */
  86static void sctp_do_ecn_ce_work(struct sctp_association *asoc,
  87                                __u32 lowest_tsn)
  88{
  89        /* Save the TSN away for comparison when we receive CWR */
  90
  91        asoc->last_ecne_tsn = lowest_tsn;
  92        asoc->need_ecne = 1;
  93}
  94
  95/* Helper function for delayed processing of SCTP ECNE chunk.  */
  96/* RFC 2960 Appendix A
  97 *
  98 * RFC 2481 details a specific bit for a sender to send in
  99 * the header of its next outbound TCP segment to indicate to
 100 * its peer that it has reduced its congestion window.  This
 101 * is termed the CWR bit.  For SCTP the same indication is made
 102 * by including the CWR chunk.  This chunk contains one data
 103 * element, i.e. the TSN number that was sent in the ECNE chunk.
 104 * This element represents the lowest TSN number in the datagram
 105 * that was originally marked with the CE bit.
 106 */
 107static struct sctp_chunk *sctp_do_ecn_ecne_work(struct sctp_association *asoc,
 108                                           __u32 lowest_tsn,
 109                                           struct sctp_chunk *chunk)
 110{
 111        struct sctp_chunk *repl;
 112
 113        /* Our previously transmitted packet ran into some congestion
 114         * so we should take action by reducing cwnd and ssthresh
 115         * and then ACK our peer that we we've done so by
 116         * sending a CWR.
 117         */
 118
 119        /* First, try to determine if we want to actually lower
 120         * our cwnd variables.  Only lower them if the ECNE looks more
 121         * recent than the last response.
 122         */
 123        if (TSN_lt(asoc->last_cwr_tsn, lowest_tsn)) {
 124                struct sctp_transport *transport;
 125
 126                /* Find which transport's congestion variables
 127                 * need to be adjusted.
 128                 */
 129                transport = sctp_assoc_lookup_tsn(asoc, lowest_tsn);
 130
 131                /* Update the congestion variables. */
 132                if (transport)
 133                        sctp_transport_lower_cwnd(transport,
 134                                                  SCTP_LOWER_CWND_ECNE);
 135                asoc->last_cwr_tsn = lowest_tsn;
 136        }
 137
 138        /* Always try to quiet the other end.  In case of lost CWR,
 139         * resend last_cwr_tsn.
 140         */
 141        repl = sctp_make_cwr(asoc, asoc->last_cwr_tsn, chunk);
 142
 143        /* If we run out of memory, it will look like a lost CWR.  We'll
 144         * get back in sync eventually.
 145         */
 146        return repl;
 147}
 148
 149/* Helper function to do delayed processing of ECN CWR chunk.  */
 150static void sctp_do_ecn_cwr_work(struct sctp_association *asoc,
 151                                 __u32 lowest_tsn)
 152{
 153        /* Turn off ECNE getting auto-prepended to every outgoing
 154         * packet
 155         */
 156        asoc->need_ecne = 0;
 157}
 158
 159/* Generate SACK if necessary.  We call this at the end of a packet.  */
 160static int sctp_gen_sack(struct sctp_association *asoc, int force,
 161                         sctp_cmd_seq_t *commands)
 162{
 163        __u32 ctsn, max_tsn_seen;
 164        struct sctp_chunk *sack;
 165        struct sctp_transport *trans = asoc->peer.last_data_from;
 166        int error = 0;
 167
 168        if (force ||
 169            (!trans && (asoc->param_flags & SPP_SACKDELAY_DISABLE)) ||
 170            (trans && (trans->param_flags & SPP_SACKDELAY_DISABLE)))
 171                asoc->peer.sack_needed = 1;
 172
 173        ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
 174        max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
 175
 176        /* From 12.2 Parameters necessary per association (i.e. the TCB):
 177         *
 178         * Ack State : This flag indicates if the next received packet
 179         *           : is to be responded to with a SACK. ...
 180         *           : When DATA chunks are out of order, SACK's
 181         *           : are not delayed (see Section 6).
 182         *
 183         * [This is actually not mentioned in Section 6, but we
 184         * implement it here anyway. --piggy]
 185         */
 186        if (max_tsn_seen != ctsn)
 187                asoc->peer.sack_needed = 1;
 188
 189        /* From 6.2  Acknowledgement on Reception of DATA Chunks:
 190         *
 191         * Section 4.2 of [RFC2581] SHOULD be followed. Specifically,
 192         * an acknowledgement SHOULD be generated for at least every
 193         * second packet (not every second DATA chunk) received, and
 194         * SHOULD be generated within 200 ms of the arrival of any
 195         * unacknowledged DATA chunk. ...
 196         */
 197        if (!asoc->peer.sack_needed) {
 198                asoc->peer.sack_cnt++;
 199
 200                /* Set the SACK delay timeout based on the
 201                 * SACK delay for the last transport
 202                 * data was received from, or the default
 203                 * for the association.
 204                 */
 205                if (trans) {
 206                        /* We will need a SACK for the next packet.  */
 207                        if (asoc->peer.sack_cnt >= trans->sackfreq - 1)
 208                                asoc->peer.sack_needed = 1;
 209
 210                        asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
 211                                trans->sackdelay;
 212                } else {
 213                        /* We will need a SACK for the next packet.  */
 214                        if (asoc->peer.sack_cnt >= asoc->sackfreq - 1)
 215                                asoc->peer.sack_needed = 1;
 216
 217                        asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
 218                                asoc->sackdelay;
 219                }
 220
 221                /* Restart the SACK timer. */
 222                sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
 223                                SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
 224        } else {
 225                asoc->a_rwnd = asoc->rwnd;
 226                sack = sctp_make_sack(asoc);
 227                if (!sack)
 228                        goto nomem;
 229
 230                asoc->peer.sack_needed = 0;
 231                asoc->peer.sack_cnt = 0;
 232
 233                sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(sack));
 234
 235                /* Stop the SACK timer.  */
 236                sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
 237                                SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
 238        }
 239
 240        return error;
 241nomem:
 242        error = -ENOMEM;
 243        return error;
 244}
 245
 246/* When the T3-RTX timer expires, it calls this function to create the
 247 * relevant state machine event.
 248 */
 249void sctp_generate_t3_rtx_event(unsigned long peer)
 250{
 251        int error;
 252        struct sctp_transport *transport = (struct sctp_transport *) peer;
 253        struct sctp_association *asoc = transport->asoc;
 254
 255        /* Check whether a task is in the sock.  */
 256
 257        sctp_bh_lock_sock(asoc->base.sk);
 258        if (sock_owned_by_user(asoc->base.sk)) {
 259                SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __func__);
 260
 261                /* Try again later.  */
 262                if (!mod_timer(&transport->T3_rtx_timer, jiffies + (HZ/20)))
 263                        sctp_transport_hold(transport);
 264                goto out_unlock;
 265        }
 266
 267        /* Is this transport really dead and just waiting around for
 268         * the timer to let go of the reference?
 269         */
 270        if (transport->dead)
 271                goto out_unlock;
 272
 273        /* Run through the state machine.  */
 274        error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
 275                           SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX),
 276                           asoc->state,
 277                           asoc->ep, asoc,
 278                           transport, GFP_ATOMIC);
 279
 280        if (error)
 281                asoc->base.sk->sk_err = -error;
 282
 283out_unlock:
 284        sctp_bh_unlock_sock(asoc->base.sk);
 285        sctp_transport_put(transport);
 286}
 287
 288/* This is a sa interface for producing timeout events.  It works
 289 * for timeouts which use the association as their parameter.
 290 */
 291static void sctp_generate_timeout_event(struct sctp_association *asoc,
 292                                        sctp_event_timeout_t timeout_type)
 293{
 294        int error = 0;
 295
 296        sctp_bh_lock_sock(asoc->base.sk);
 297        if (sock_owned_by_user(asoc->base.sk)) {
 298                SCTP_DEBUG_PRINTK("%s:Sock is busy: timer %d\n",
 299                                  __func__,
 300                                  timeout_type);
 301
 302                /* Try again later.  */
 303                if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20)))
 304                        sctp_association_hold(asoc);
 305                goto out_unlock;
 306        }
 307
 308        /* Is this association really dead and just waiting around for
 309         * the timer to let go of the reference?
 310         */
 311        if (asoc->base.dead)
 312                goto out_unlock;
 313
 314        /* Run through the state machine.  */
 315        error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
 316                           SCTP_ST_TIMEOUT(timeout_type),
 317                           asoc->state, asoc->ep, asoc,
 318                           (void *)timeout_type, GFP_ATOMIC);
 319
 320        if (error)
 321                asoc->base.sk->sk_err = -error;
 322
 323out_unlock:
 324        sctp_bh_unlock_sock(asoc->base.sk);
 325        sctp_association_put(asoc);
 326}
 327
 328static void sctp_generate_t1_cookie_event(unsigned long data)
 329{
 330        struct sctp_association *asoc = (struct sctp_association *) data;
 331        sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
 332}
 333
 334static void sctp_generate_t1_init_event(unsigned long data)
 335{
 336        struct sctp_association *asoc = (struct sctp_association *) data;
 337        sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
 338}
 339
 340static void sctp_generate_t2_shutdown_event(unsigned long data)
 341{
 342        struct sctp_association *asoc = (struct sctp_association *) data;
 343        sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
 344}
 345
 346static void sctp_generate_t4_rto_event(unsigned long data)
 347{
 348        struct sctp_association *asoc = (struct sctp_association *) data;
 349        sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
 350}
 351
 352static void sctp_generate_t5_shutdown_guard_event(unsigned long data)
 353{
 354        struct sctp_association *asoc = (struct sctp_association *)data;
 355        sctp_generate_timeout_event(asoc,
 356                                    SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);
 357
 358} /* sctp_generate_t5_shutdown_guard_event() */
 359
 360static void sctp_generate_autoclose_event(unsigned long data)
 361{
 362        struct sctp_association *asoc = (struct sctp_association *) data;
 363        sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE);
 364}
 365
 366/* Generate a heart beat event.  If the sock is busy, reschedule.   Make
 367 * sure that the transport is still valid.
 368 */
 369void sctp_generate_heartbeat_event(unsigned long data)
 370{
 371        int error = 0;
 372        struct sctp_transport *transport = (struct sctp_transport *) data;
 373        struct sctp_association *asoc = transport->asoc;
 374
 375        sctp_bh_lock_sock(asoc->base.sk);
 376        if (sock_owned_by_user(asoc->base.sk)) {
 377                SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __func__);
 378
 379                /* Try again later.  */
 380                if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20)))
 381                        sctp_transport_hold(transport);
 382                goto out_unlock;
 383        }
 384
 385        /* Is this structure just waiting around for us to actually
 386         * get destroyed?
 387         */
 388        if (transport->dead)
 389                goto out_unlock;
 390
 391        error = sctp_do_sm(SCTP_EVENT_T_TIMEOUT,
 392                           SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
 393                           asoc->state, asoc->ep, asoc,
 394                           transport, GFP_ATOMIC);
 395
 396         if (error)
 397                 asoc->base.sk->sk_err = -error;
 398
 399out_unlock:
 400        sctp_bh_unlock_sock(asoc->base.sk);
 401        sctp_transport_put(transport);
 402}
 403
 404/* Handle the timeout of the ICMP protocol unreachable timer.  Trigger
 405 * the correct state machine transition that will close the association.
 406 */
 407void sctp_generate_proto_unreach_event(unsigned long data)
 408{
 409        struct sctp_transport *transport = (struct sctp_transport *) data;
 410        struct sctp_association *asoc = transport->asoc;
 411        
 412        sctp_bh_lock_sock(asoc->base.sk);
 413        if (sock_owned_by_user(asoc->base.sk)) {
 414                SCTP_DEBUG_PRINTK("%s:Sock is busy.\n", __func__);
 415
 416                /* Try again later.  */
 417                if (!mod_timer(&transport->proto_unreach_timer,
 418                                jiffies + (HZ/20)))
 419                        sctp_association_hold(asoc);
 420                goto out_unlock;
 421        }
 422
 423        /* Is this structure just waiting around for us to actually
 424         * get destroyed?
 425         */
 426        if (asoc->base.dead)
 427                goto out_unlock;
 428
 429        sctp_do_sm(SCTP_EVENT_T_OTHER,
 430                   SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH),
 431                   asoc->state, asoc->ep, asoc, transport, GFP_ATOMIC);
 432
 433out_unlock:
 434        sctp_bh_unlock_sock(asoc->base.sk);
 435        sctp_association_put(asoc);
 436}
 437
 438
 439/* Inject a SACK Timeout event into the state machine.  */
 440static void sctp_generate_sack_event(unsigned long data)
 441{
 442        struct sctp_association *asoc = (struct sctp_association *) data;
 443        sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
 444}
 445
 446sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
 447        NULL,
 448        sctp_generate_t1_cookie_event,
 449        sctp_generate_t1_init_event,
 450        sctp_generate_t2_shutdown_event,
 451        NULL,
 452        sctp_generate_t4_rto_event,
 453        sctp_generate_t5_shutdown_guard_event,
 454        NULL,
 455        sctp_generate_sack_event,
 456        sctp_generate_autoclose_event,
 457};
 458
 459
 460/* RFC 2960 8.2 Path Failure Detection
 461 *
 462 * When its peer endpoint is multi-homed, an endpoint should keep a
 463 * error counter for each of the destination transport addresses of the
 464 * peer endpoint.
 465 *
 466 * Each time the T3-rtx timer expires on any address, or when a
 467 * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
 468 * the error counter of that destination address will be incremented.
 469 * When the value in the error counter exceeds the protocol parameter
 470 * 'Path.Max.Retrans' of that destination address, the endpoint should
 471 * mark the destination transport address as inactive, and a
 472 * notification SHOULD be sent to the upper layer.
 473 *
 474 */
 475static void sctp_do_8_2_transport_strike(sctp_cmd_seq_t *commands,
 476                                         struct sctp_association *asoc,
 477                                         struct sctp_transport *transport,
 478                                         int is_hb)
 479{
 480        /* The check for association's overall error counter exceeding the
 481         * threshold is done in the state function.
 482         */
 483        /* We are here due to a timer expiration.  If the timer was
 484         * not a HEARTBEAT, then normal error tracking is done.
 485         * If the timer was a heartbeat, we only increment error counts
 486         * when we already have an outstanding HEARTBEAT that has not
 487         * been acknowledged.
 488         * Additionally, some tranport states inhibit error increments.
 489         */
 490        if (!is_hb) {
 491                asoc->overall_error_count++;
 492                if (transport->state != SCTP_INACTIVE)
 493                        transport->error_count++;
 494         } else if (transport->hb_sent) {
 495                if (transport->state != SCTP_UNCONFIRMED)
 496                        asoc->overall_error_count++;
 497                if (transport->state != SCTP_INACTIVE)
 498                        transport->error_count++;
 499        }
 500
 501        /* If the transport error count is greater than the pf_retrans
 502         * threshold, and less than pathmaxrtx, then mark this transport
 503         * as Partially Failed, ee SCTP Quick Failover Draft, secon 5.1,
 504         * point 1
 505         */
 506        if ((transport->state != SCTP_PF) &&
 507           (asoc->pf_retrans < transport->pathmaxrxt) &&
 508           (transport->error_count > asoc->pf_retrans)) {
 509
 510                sctp_assoc_control_transport(asoc, transport,
 511                                             SCTP_TRANSPORT_PF,
 512                                             0);
 513
 514                /* Update the hb timer to resend a heartbeat every rto */
 515                sctp_cmd_hb_timer_update(commands, transport);
 516        }
 517
 518        if (transport->state != SCTP_INACTIVE &&
 519            (transport->error_count > transport->pathmaxrxt)) {
 520                SCTP_DEBUG_PRINTK_IPADDR("transport_strike:association %p",
 521                                         " transport IP: port:%d failed.\n",
 522                                         asoc,
 523                                         (&transport->ipaddr),
 524                                         ntohs(transport->ipaddr.v4.sin_port));
 525                sctp_assoc_control_transport(asoc, transport,
 526                                             SCTP_TRANSPORT_DOWN,
 527                                             SCTP_FAILED_THRESHOLD);
 528        }
 529
 530        /* E2) For the destination address for which the timer
 531         * expires, set RTO <- RTO * 2 ("back off the timer").  The
 532         * maximum value discussed in rule C7 above (RTO.max) may be
 533         * used to provide an upper bound to this doubling operation.
 534         *
 535         * Special Case:  the first HB doesn't trigger exponential backoff.
 536         * The first unacknowledged HB triggers it.  We do this with a flag
 537         * that indicates that we have an outstanding HB.
 538         */
 539        if (!is_hb || transport->hb_sent) {
 540                transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
 541        }
 542}
 543
 544/* Worker routine to handle INIT command failure.  */
 545static void sctp_cmd_init_failed(sctp_cmd_seq_t *commands,
 546                                 struct sctp_association *asoc,
 547                                 unsigned int error)
 548{
 549        struct sctp_ulpevent *event;
 550
 551        event = sctp_ulpevent_make_assoc_change(asoc,0, SCTP_CANT_STR_ASSOC,
 552                                                (__u16)error, 0, 0, NULL,
 553                                                GFP_ATOMIC);
 554
 555        if (event)
 556                sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 557                                SCTP_ULPEVENT(event));
 558
 559        sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 560                        SCTP_STATE(SCTP_STATE_CLOSED));
 561
 562        /* SEND_FAILED sent later when cleaning up the association. */
 563        asoc->outqueue.error = error;
 564        sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 565}
 566
 567/* Worker routine to handle SCTP_CMD_ASSOC_FAILED.  */
 568static void sctp_cmd_assoc_failed(sctp_cmd_seq_t *commands,
 569                                  struct sctp_association *asoc,
 570                                  sctp_event_t event_type,
 571                                  sctp_subtype_t subtype,
 572                                  struct sctp_chunk *chunk,
 573                                  unsigned int error)
 574{
 575        struct sctp_ulpevent *event;
 576
 577        /* Cancel any partial delivery in progress. */
 578        sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
 579
 580        if (event_type == SCTP_EVENT_T_CHUNK && subtype.chunk == SCTP_CID_ABORT)
 581                event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
 582                                                (__u16)error, 0, 0, chunk,
 583                                                GFP_ATOMIC);
 584        else
 585                event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
 586                                                (__u16)error, 0, 0, NULL,
 587                                                GFP_ATOMIC);
 588        if (event)
 589                sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 590                                SCTP_ULPEVENT(event));
 591
 592        sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 593                        SCTP_STATE(SCTP_STATE_CLOSED));
 594
 595        /* SEND_FAILED sent later when cleaning up the association. */
 596        asoc->outqueue.error = error;
 597        sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 598}
 599
 600/* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
 601 * inside the cookie.  In reality, this is only used for INIT-ACK processing
 602 * since all other cases use "temporary" associations and can do all
 603 * their work in statefuns directly.
 604 */
 605static int sctp_cmd_process_init(sctp_cmd_seq_t *commands,
 606                                 struct sctp_association *asoc,
 607                                 struct sctp_chunk *chunk,
 608                                 sctp_init_chunk_t *peer_init,
 609                                 gfp_t gfp)
 610{
 611        int error;
 612
 613        /* We only process the init as a sideeffect in a single
 614         * case.   This is when we process the INIT-ACK.   If we
 615         * fail during INIT processing (due to malloc problems),
 616         * just return the error and stop processing the stack.
 617         */
 618        if (!sctp_process_init(asoc, chunk, sctp_source(chunk), peer_init, gfp))
 619                error = -ENOMEM;
 620        else
 621                error = 0;
 622
 623        return error;
 624}
 625
 626/* Helper function to break out starting up of heartbeat timers.  */
 627static void sctp_cmd_hb_timers_start(sctp_cmd_seq_t *cmds,
 628                                     struct sctp_association *asoc)
 629{
 630        struct sctp_transport *t;
 631
 632        /* Start a heartbeat timer for each transport on the association.
 633         * hold a reference on the transport to make sure none of
 634         * the needed data structures go away.
 635         */
 636        list_for_each_entry(t, &asoc->peer.transport_addr_list, transports) {
 637
 638                if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 639                        sctp_transport_hold(t);
 640        }
 641}
 642
 643static void sctp_cmd_hb_timers_stop(sctp_cmd_seq_t *cmds,
 644                                    struct sctp_association *asoc)
 645{
 646        struct sctp_transport *t;
 647
 648        /* Stop all heartbeat timers. */
 649
 650        list_for_each_entry(t, &asoc->peer.transport_addr_list,
 651                        transports) {
 652                if (del_timer(&t->hb_timer))
 653                        sctp_transport_put(t);
 654        }
 655}
 656
 657/* Helper function to stop any pending T3-RTX timers */
 658static void sctp_cmd_t3_rtx_timers_stop(sctp_cmd_seq_t *cmds,
 659                                        struct sctp_association *asoc)
 660{
 661        struct sctp_transport *t;
 662
 663        list_for_each_entry(t, &asoc->peer.transport_addr_list,
 664                        transports) {
 665                if (timer_pending(&t->T3_rtx_timer) &&
 666                    del_timer(&t->T3_rtx_timer)) {
 667                        sctp_transport_put(t);
 668                }
 669        }
 670}
 671
 672
 673/* Helper function to update the heartbeat timer. */
 674static void sctp_cmd_hb_timer_update(sctp_cmd_seq_t *cmds,
 675                                     struct sctp_transport *t)
 676{
 677        /* Update the heartbeat timer.  */
 678        if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 679                sctp_transport_hold(t);
 680}
 681
 682/* Helper function to handle the reception of an HEARTBEAT ACK.  */
 683static void sctp_cmd_transport_on(sctp_cmd_seq_t *cmds,
 684                                  struct sctp_association *asoc,
 685                                  struct sctp_transport *t,
 686                                  struct sctp_chunk *chunk)
 687{
 688        sctp_sender_hb_info_t *hbinfo;
 689        int was_unconfirmed = 0;
 690
 691        /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
 692         * HEARTBEAT should clear the error counter of the destination
 693         * transport address to which the HEARTBEAT was sent.
 694         */
 695        t->error_count = 0;
 696
 697        /*
 698         * Although RFC4960 specifies that the overall error count must
 699         * be cleared when a HEARTBEAT ACK is received, we make an
 700         * exception while in SHUTDOWN PENDING. If the peer keeps its
 701         * window shut forever, we may never be able to transmit our
 702         * outstanding data and rely on the retransmission limit be reached
 703         * to shutdown the association.
 704         */
 705        if (t->asoc->state != SCTP_STATE_SHUTDOWN_PENDING)
 706                t->asoc->overall_error_count = 0;
 707
 708        /* Clear the hb_sent flag to signal that we had a good
 709         * acknowledgement.
 710         */
 711        t->hb_sent = 0;
 712
 713        /* Mark the destination transport address as active if it is not so
 714         * marked.
 715         */
 716        if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED)) {
 717                was_unconfirmed = 1;
 718                sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
 719                                             SCTP_HEARTBEAT_SUCCESS);
 720        }
 721
 722        if (t->state == SCTP_PF)
 723                sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
 724                                             SCTP_HEARTBEAT_SUCCESS);
 725
 726        /* The receiver of the HEARTBEAT ACK should also perform an
 727         * RTT measurement for that destination transport address
 728         * using the time value carried in the HEARTBEAT ACK chunk.
 729         * If the transport's rto_pending variable has been cleared,
 730         * it was most likely due to a retransmit.  However, we want
 731         * to re-enable it to properly update the rto.
 732         */
 733        if (t->rto_pending == 0)
 734                t->rto_pending = 1;
 735
 736        hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
 737        sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
 738
 739        /* Update the heartbeat timer.  */
 740        if (!mod_timer(&t->hb_timer, sctp_transport_timeout(t)))
 741                sctp_transport_hold(t);
 742
 743        if (was_unconfirmed && asoc->peer.transport_count == 1)
 744                sctp_transport_immediate_rtx(t);
 745}
 746
 747
 748/* Helper function to process the process SACK command.  */
 749static int sctp_cmd_process_sack(sctp_cmd_seq_t *cmds,
 750                                 struct sctp_association *asoc,
 751                                 struct sctp_sackhdr *sackh)
 752{
 753        int err = 0;
 754
 755        if (sctp_outq_sack(&asoc->outqueue, sackh)) {
 756                /* There are no more TSNs awaiting SACK.  */
 757                err = sctp_do_sm(SCTP_EVENT_T_OTHER,
 758                                 SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
 759                                 asoc->state, asoc->ep, asoc, NULL,
 760                                 GFP_ATOMIC);
 761        }
 762
 763        return err;
 764}
 765
 766/* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
 767 * the transport for a shutdown chunk.
 768 */
 769static void sctp_cmd_setup_t2(sctp_cmd_seq_t *cmds,
 770                              struct sctp_association *asoc,
 771                              struct sctp_chunk *chunk)
 772{
 773        struct sctp_transport *t;
 774
 775        if (chunk->transport)
 776                t = chunk->transport;
 777        else {
 778                t = sctp_assoc_choose_alter_transport(asoc,
 779                                              asoc->shutdown_last_sent_to);
 780                chunk->transport = t;
 781        }
 782        asoc->shutdown_last_sent_to = t;
 783        asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
 784}
 785
 786/* Helper function to change the state of an association. */
 787static void sctp_cmd_new_state(sctp_cmd_seq_t *cmds,
 788                               struct sctp_association *asoc,
 789                               sctp_state_t state)
 790{
 791        struct sock *sk = asoc->base.sk;
 792
 793        asoc->state = state;
 794
 795        SCTP_DEBUG_PRINTK("sctp_cmd_new_state: asoc %p[%s]\n",
 796                          asoc, sctp_state_tbl[state]);
 797
 798        if (sctp_style(sk, TCP)) {
 799                /* Change the sk->sk_state of a TCP-style socket that has
 800                 * successfully completed a connect() call.
 801                 */
 802                if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
 803                        sk->sk_state = SCTP_SS_ESTABLISHED;
 804
 805                /* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
 806                if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
 807                    sctp_sstate(sk, ESTABLISHED))
 808                        sk->sk_shutdown |= RCV_SHUTDOWN;
 809        }
 810
 811        if (sctp_state(asoc, COOKIE_WAIT)) {
 812                /* Reset init timeouts since they may have been
 813                 * increased due to timer expirations.
 814                 */
 815                asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
 816                                                asoc->rto_initial;
 817                asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
 818                                                asoc->rto_initial;
 819        }
 820
 821        if (sctp_state(asoc, ESTABLISHED) ||
 822            sctp_state(asoc, CLOSED) ||
 823            sctp_state(asoc, SHUTDOWN_RECEIVED)) {
 824                /* Wake up any processes waiting in the asoc's wait queue in
 825                 * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
 826                 */
 827                if (waitqueue_active(&asoc->wait))
 828                        wake_up_interruptible(&asoc->wait);
 829
 830                /* Wake up any processes waiting in the sk's sleep queue of
 831                 * a TCP-style or UDP-style peeled-off socket in
 832                 * sctp_wait_for_accept() or sctp_wait_for_packet().
 833                 * For a UDP-style socket, the waiters are woken up by the
 834                 * notifications.
 835                 */
 836                if (!sctp_style(sk, UDP))
 837                        sk->sk_state_change(sk);
 838        }
 839}
 840
 841/* Helper function to delete an association. */
 842static void sctp_cmd_delete_tcb(sctp_cmd_seq_t *cmds,
 843                                struct sctp_association *asoc)
 844{
 845        struct sock *sk = asoc->base.sk;
 846
 847        /* If it is a non-temporary association belonging to a TCP-style
 848         * listening socket that is not closed, do not free it so that accept()
 849         * can pick it up later.
 850         */
 851        if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
 852            (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
 853                return;
 854
 855        sctp_unhash_established(asoc);
 856        sctp_association_free(asoc);
 857}
 858
 859/*
 860 * ADDIP Section 4.1 ASCONF Chunk Procedures
 861 * A4) Start a T-4 RTO timer, using the RTO value of the selected
 862 * destination address (we use active path instead of primary path just
 863 * because primary path may be inactive.
 864 */
 865static void sctp_cmd_setup_t4(sctp_cmd_seq_t *cmds,
 866                                struct sctp_association *asoc,
 867                                struct sctp_chunk *chunk)
 868{
 869        struct sctp_transport *t;
 870
 871        t = sctp_assoc_choose_alter_transport(asoc, chunk->transport);
 872        asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
 873        chunk->transport = t;
 874}
 875
 876/* Process an incoming Operation Error Chunk. */
 877static void sctp_cmd_process_operr(sctp_cmd_seq_t *cmds,
 878                                   struct sctp_association *asoc,
 879                                   struct sctp_chunk *chunk)
 880{
 881        struct sctp_errhdr *err_hdr;
 882        struct sctp_ulpevent *ev;
 883
 884        while (chunk->chunk_end > chunk->skb->data) {
 885                err_hdr = (struct sctp_errhdr *)(chunk->skb->data);
 886
 887                ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
 888                                                     GFP_ATOMIC);
 889                if (!ev)
 890                        return;
 891
 892                sctp_ulpq_tail_event(&asoc->ulpq, ev);
 893
 894                switch (err_hdr->cause) {
 895                case SCTP_ERROR_UNKNOWN_CHUNK:
 896                {
 897                        sctp_chunkhdr_t *unk_chunk_hdr;
 898
 899                        unk_chunk_hdr = (sctp_chunkhdr_t *)err_hdr->variable;
 900                        switch (unk_chunk_hdr->type) {
 901                        /* ADDIP 4.1 A9) If the peer responds to an ASCONF with
 902                         * an ERROR chunk reporting that it did not recognized
 903                         * the ASCONF chunk type, the sender of the ASCONF MUST
 904                         * NOT send any further ASCONF chunks and MUST stop its
 905                         * T-4 timer.
 906                         */
 907                        case SCTP_CID_ASCONF:
 908                                if (asoc->peer.asconf_capable == 0)
 909                                        break;
 910
 911                                asoc->peer.asconf_capable = 0;
 912                                sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
 913                                        SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
 914                                break;
 915                        default:
 916                                break;
 917                        }
 918                        break;
 919                }
 920                default:
 921                        break;
 922                }
 923        }
 924}
 925
 926/* Process variable FWDTSN chunk information. */
 927static void sctp_cmd_process_fwdtsn(struct sctp_ulpq *ulpq,
 928                                    struct sctp_chunk *chunk)
 929{
 930        struct sctp_fwdtsn_skip *skip;
 931        /* Walk through all the skipped SSNs */
 932        sctp_walk_fwdtsn(skip, chunk) {
 933                sctp_ulpq_skip(ulpq, ntohs(skip->stream), ntohs(skip->ssn));
 934        }
 935}
 936
 937/* Helper function to remove the association non-primary peer
 938 * transports.
 939 */
 940static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
 941{
 942        struct sctp_transport *t;
 943        struct list_head *pos;
 944        struct list_head *temp;
 945
 946        list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
 947                t = list_entry(pos, struct sctp_transport, transports);
 948                if (!sctp_cmp_addr_exact(&t->ipaddr,
 949                                         &asoc->peer.primary_addr)) {
 950                        sctp_assoc_del_peer(asoc, &t->ipaddr);
 951                }
 952        }
 953}
 954
 955/* Helper function to set sk_err on a 1-1 style socket. */
 956static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
 957{
 958        struct sock *sk = asoc->base.sk;
 959
 960        if (!sctp_style(sk, UDP))
 961                sk->sk_err = error;
 962}
 963
 964/* Helper function to generate an association change event */
 965static void sctp_cmd_assoc_change(sctp_cmd_seq_t *commands,
 966                                 struct sctp_association *asoc,
 967                                 u8 state)
 968{
 969        struct sctp_ulpevent *ev;
 970
 971        ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0,
 972                                            asoc->c.sinit_num_ostreams,
 973                                            asoc->c.sinit_max_instreams,
 974                                            NULL, GFP_ATOMIC);
 975        if (ev)
 976                sctp_ulpq_tail_event(&asoc->ulpq, ev);
 977}
 978
 979/* Helper function to generate an adaptation indication event */
 980static void sctp_cmd_adaptation_ind(sctp_cmd_seq_t *commands,
 981                                    struct sctp_association *asoc)
 982{
 983        struct sctp_ulpevent *ev;
 984
 985        ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
 986
 987        if (ev)
 988                sctp_ulpq_tail_event(&asoc->ulpq, ev);
 989}
 990
 991
 992static void sctp_cmd_t1_timer_update(struct sctp_association *asoc,
 993                                    sctp_event_timeout_t timer,
 994                                    char *name)
 995{
 996        struct sctp_transport *t;
 997
 998        t = asoc->init_last_sent_to;
 999        asoc->init_err_counter++;
1000
1001        if (t->init_sent_count > (asoc->init_cycle + 1)) {
1002                asoc->timeouts[timer] *= 2;
1003                if (asoc->timeouts[timer] > asoc->max_init_timeo) {
1004                        asoc->timeouts[timer] = asoc->max_init_timeo;
1005                }
1006                asoc->init_cycle++;
1007                SCTP_DEBUG_PRINTK(
1008                        "T1 %s Timeout adjustment"
1009                        " init_err_counter: %d"
1010                        " cycle: %d"
1011                        " timeout: %ld\n",
1012                        name,
1013                        asoc->init_err_counter,
1014                        asoc->init_cycle,
1015                        asoc->timeouts[timer]);
1016        }
1017
1018}
1019
1020/* Send the whole message, chunk by chunk, to the outqueue.
1021 * This way the whole message is queued up and bundling if
1022 * encouraged for small fragments.
1023 */
1024static int sctp_cmd_send_msg(struct sctp_association *asoc,
1025                                struct sctp_datamsg *msg)
1026{
1027        struct sctp_chunk *chunk;
1028        int error = 0;
1029
1030        list_for_each_entry(chunk, &msg->chunks, frag_list) {
1031                error = sctp_outq_tail(&asoc->outqueue, chunk);
1032                if (error)
1033                        break;
1034        }
1035
1036        return error;
1037}
1038
1039
1040/* Sent the next ASCONF packet currently stored in the association.
1041 * This happens after the ASCONF_ACK was succeffully processed.
1042 */
1043static void sctp_cmd_send_asconf(struct sctp_association *asoc)
1044{
1045        /* Send the next asconf chunk from the addip chunk
1046         * queue.
1047         */
1048        if (!list_empty(&asoc->addip_chunk_list)) {
1049                struct list_head *entry = asoc->addip_chunk_list.next;
1050                struct sctp_chunk *asconf = list_entry(entry,
1051                                                struct sctp_chunk, list);
1052                list_del_init(entry);
1053
1054                /* Hold the chunk until an ASCONF_ACK is received. */
1055                sctp_chunk_hold(asconf);
1056                if (sctp_primitive_ASCONF(asoc, asconf))
1057                        sctp_chunk_free(asconf);
1058                else
1059                        asoc->addip_last_asconf = asconf;
1060        }
1061}
1062
1063
1064/* These three macros allow us to pull the debugging code out of the
1065 * main flow of sctp_do_sm() to keep attention focused on the real
1066 * functionality there.
1067 */
1068#define DEBUG_PRE \
1069        SCTP_DEBUG_PRINTK("sctp_do_sm prefn: " \
1070                          "ep %p, %s, %s, asoc %p[%s], %s\n", \
1071                          ep, sctp_evttype_tbl[event_type], \
1072                          (*debug_fn)(subtype), asoc, \
1073                          sctp_state_tbl[state], state_fn->name)
1074
1075#define DEBUG_POST \
1076        SCTP_DEBUG_PRINTK("sctp_do_sm postfn: " \
1077                          "asoc %p, status: %s\n", \
1078                          asoc, sctp_status_tbl[status])
1079
1080#define DEBUG_POST_SFX \
1081        SCTP_DEBUG_PRINTK("sctp_do_sm post sfx: error %d, asoc %p[%s]\n", \
1082                          error, asoc, \
1083                          sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
1084                          sctp_assoc2id(asoc)))?asoc->state:SCTP_STATE_CLOSED])
1085
1086/*
1087 * This is the master state machine processing function.
1088 *
1089 * If you want to understand all of lksctp, this is a
1090 * good place to start.
1091 */
1092int sctp_do_sm(sctp_event_t event_type, sctp_subtype_t subtype,
1093               sctp_state_t state,
1094               struct sctp_endpoint *ep,
1095               struct sctp_association *asoc,
1096               void *event_arg,
1097               gfp_t gfp)
1098{
1099        sctp_cmd_seq_t commands;
1100        const sctp_sm_table_entry_t *state_fn;
1101        sctp_disposition_t status;
1102        int error = 0;
1103        typedef const char *(printfn_t)(sctp_subtype_t);
1104
1105        static printfn_t *table[] = {
1106                NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
1107        };
1108        printfn_t *debug_fn  __attribute__ ((unused)) = table[event_type];
1109
1110        /* Look up the state function, run it, and then process the
1111         * side effects.  These three steps are the heart of lksctp.
1112         */
1113        state_fn = sctp_sm_lookup_event(event_type, state, subtype);
1114
1115        sctp_init_cmd_seq(&commands);
1116
1117        DEBUG_PRE;
1118        status = (*state_fn->fn)(ep, asoc, subtype, event_arg, &commands);
1119        DEBUG_POST;
1120
1121        error = sctp_side_effects(event_type, subtype, state,
1122                                  ep, asoc, event_arg, status,
1123                                  &commands, gfp);
1124        DEBUG_POST_SFX;
1125
1126        return error;
1127}
1128
1129#undef DEBUG_PRE
1130#undef DEBUG_POST
1131
1132/*****************************************************************
1133 * This the master state function side effect processing function.
1134 *****************************************************************/
1135static int sctp_side_effects(sctp_event_t event_type, sctp_subtype_t subtype,
1136                             sctp_state_t state,
1137                             struct sctp_endpoint *ep,
1138                             struct sctp_association *asoc,
1139                             void *event_arg,
1140                             sctp_disposition_t status,
1141                             sctp_cmd_seq_t *commands,
1142                             gfp_t gfp)
1143{
1144        int error;
1145
1146        /* FIXME - Most of the dispositions left today would be categorized
1147         * as "exceptional" dispositions.  For those dispositions, it
1148         * may not be proper to run through any of the commands at all.
1149         * For example, the command interpreter might be run only with
1150         * disposition SCTP_DISPOSITION_CONSUME.
1151         */
1152        if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
1153                                               ep, asoc,
1154                                               event_arg, status,
1155                                               commands, gfp)))
1156                goto bail;
1157
1158        switch (status) {
1159        case SCTP_DISPOSITION_DISCARD:
1160                SCTP_DEBUG_PRINTK("Ignored sctp protocol event - state %d, "
1161                                  "event_type %d, event_id %d\n",
1162                                  state, event_type, subtype.chunk);
1163                break;
1164
1165        case SCTP_DISPOSITION_NOMEM:
1166                /* We ran out of memory, so we need to discard this
1167                 * packet.
1168                 */
1169                /* BUG--we should now recover some memory, probably by
1170                 * reneging...
1171                 */
1172                error = -ENOMEM;
1173                break;
1174
1175        case SCTP_DISPOSITION_DELETE_TCB:
1176                /* This should now be a command. */
1177                break;
1178
1179        case SCTP_DISPOSITION_CONSUME:
1180        case SCTP_DISPOSITION_ABORT:
1181                /*
1182                 * We should no longer have much work to do here as the
1183                 * real work has been done as explicit commands above.
1184                 */
1185                break;
1186
1187        case SCTP_DISPOSITION_VIOLATION:
1188                net_err_ratelimited("protocol violation state %d chunkid %d\n",
1189                                    state, subtype.chunk);
1190                break;
1191
1192        case SCTP_DISPOSITION_NOT_IMPL:
1193                pr_warn("unimplemented feature in state %d, event_type %d, event_id %d\n",
1194                        state, event_type, subtype.chunk);
1195                break;
1196
1197        case SCTP_DISPOSITION_BUG:
1198                pr_err("bug in state %d, event_type %d, event_id %d\n",
1199                       state, event_type, subtype.chunk);
1200                BUG();
1201                break;
1202
1203        default:
1204                pr_err("impossible disposition %d in state %d, event_type %d, event_id %d\n",
1205                       status, state, event_type, subtype.chunk);
1206                BUG();
1207                break;
1208        }
1209
1210bail:
1211        return error;
1212}
1213
1214/********************************************************************
1215 * 2nd Level Abstractions
1216 ********************************************************************/
1217
1218/* This is the side-effect interpreter.  */
1219static int sctp_cmd_interpreter(sctp_event_t event_type,
1220                                sctp_subtype_t subtype,
1221                                sctp_state_t state,
1222                                struct sctp_endpoint *ep,
1223                                struct sctp_association *asoc,
1224                                void *event_arg,
1225                                sctp_disposition_t status,
1226                                sctp_cmd_seq_t *commands,
1227                                gfp_t gfp)
1228{
1229        int error = 0;
1230        int force;
1231        sctp_cmd_t *cmd;
1232        struct sctp_chunk *new_obj;
1233        struct sctp_chunk *chunk = NULL;
1234        struct sctp_packet *packet;
1235        struct timer_list *timer;
1236        unsigned long timeout;
1237        struct sctp_transport *t;
1238        struct sctp_sackhdr sackh;
1239        int local_cork = 0;
1240
1241        if (SCTP_EVENT_T_TIMEOUT != event_type)
1242                chunk = event_arg;
1243
1244        /* Note:  This whole file is a huge candidate for rework.
1245         * For example, each command could either have its own handler, so
1246         * the loop would look like:
1247         *     while (cmds)
1248         *         cmd->handle(x, y, z)
1249         * --jgrimm
1250         */
1251        while (NULL != (cmd = sctp_next_cmd(commands))) {
1252                switch (cmd->verb) {
1253                case SCTP_CMD_NOP:
1254                        /* Do nothing. */
1255                        break;
1256
1257                case SCTP_CMD_NEW_ASOC:
1258                        /* Register a new association.  */
1259                        if (local_cork) {
1260                                sctp_outq_uncork(&asoc->outqueue);
1261                                local_cork = 0;
1262                        }
1263                        asoc = cmd->obj.ptr;
1264                        /* Register with the endpoint.  */
1265                        sctp_endpoint_add_asoc(ep, asoc);
1266                        sctp_hash_established(asoc);
1267                        break;
1268
1269                case SCTP_CMD_UPDATE_ASSOC:
1270                       sctp_assoc_update(asoc, cmd->obj.ptr);
1271                       break;
1272
1273                case SCTP_CMD_PURGE_OUTQUEUE:
1274                       sctp_outq_teardown(&asoc->outqueue);
1275                       break;
1276
1277                case SCTP_CMD_DELETE_TCB:
1278                        if (local_cork) {
1279                                sctp_outq_uncork(&asoc->outqueue);
1280                                local_cork = 0;
1281                        }
1282                        /* Delete the current association.  */
1283                        sctp_cmd_delete_tcb(commands, asoc);
1284                        asoc = NULL;
1285                        break;
1286
1287                case SCTP_CMD_NEW_STATE:
1288                        /* Enter a new state.  */
1289                        sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1290                        break;
1291
1292                case SCTP_CMD_REPORT_TSN:
1293                        /* Record the arrival of a TSN.  */
1294                        error = sctp_tsnmap_mark(&asoc->peer.tsn_map,
1295                                                 cmd->obj.u32, NULL);
1296                        break;
1297
1298                case SCTP_CMD_REPORT_FWDTSN:
1299                        /* Move the Cumulattive TSN Ack ahead. */
1300                        sctp_tsnmap_skip(&asoc->peer.tsn_map, cmd->obj.u32);
1301
1302                        /* purge the fragmentation queue */
1303                        sctp_ulpq_reasm_flushtsn(&asoc->ulpq, cmd->obj.u32);
1304
1305                        /* Abort any in progress partial delivery. */
1306                        sctp_ulpq_abort_pd(&asoc->ulpq, GFP_ATOMIC);
1307                        break;
1308
1309                case SCTP_CMD_PROCESS_FWDTSN:
1310                        sctp_cmd_process_fwdtsn(&asoc->ulpq, cmd->obj.ptr);
1311                        break;
1312
1313                case SCTP_CMD_GEN_SACK:
1314                        /* Generate a Selective ACK.
1315                         * The argument tells us whether to just count
1316                         * the packet and MAYBE generate a SACK, or
1317                         * force a SACK out.
1318                         */
1319                        force = cmd->obj.i32;
1320                        error = sctp_gen_sack(asoc, force, commands);
1321                        break;
1322
1323                case SCTP_CMD_PROCESS_SACK:
1324                        /* Process an inbound SACK.  */
1325                        error = sctp_cmd_process_sack(commands, asoc,
1326                                                      cmd->obj.ptr);
1327                        break;
1328
1329                case SCTP_CMD_GEN_INIT_ACK:
1330                        /* Generate an INIT ACK chunk.  */
1331                        new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1332                                                     0);
1333                        if (!new_obj)
1334                                goto nomem;
1335
1336                        sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1337                                        SCTP_CHUNK(new_obj));
1338                        break;
1339
1340                case SCTP_CMD_PEER_INIT:
1341                        /* Process a unified INIT from the peer.
1342                         * Note: Only used during INIT-ACK processing.  If
1343                         * there is an error just return to the outter
1344                         * layer which will bail.
1345                         */
1346                        error = sctp_cmd_process_init(commands, asoc, chunk,
1347                                                      cmd->obj.ptr, gfp);
1348                        break;
1349
1350                case SCTP_CMD_GEN_COOKIE_ECHO:
1351                        /* Generate a COOKIE ECHO chunk.  */
1352                        new_obj = sctp_make_cookie_echo(asoc, chunk);
1353                        if (!new_obj) {
1354                                if (cmd->obj.ptr)
1355                                        sctp_chunk_free(cmd->obj.ptr);
1356                                goto nomem;
1357                        }
1358                        sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1359                                        SCTP_CHUNK(new_obj));
1360
1361                        /* If there is an ERROR chunk to be sent along with
1362                         * the COOKIE_ECHO, send it, too.
1363                         */
1364                        if (cmd->obj.ptr)
1365                                sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1366                                                SCTP_CHUNK(cmd->obj.ptr));
1367
1368                        if (new_obj->transport) {
1369                                new_obj->transport->init_sent_count++;
1370                                asoc->init_last_sent_to = new_obj->transport;
1371                        }
1372
1373                        /* FIXME - Eventually come up with a cleaner way to
1374                         * enabling COOKIE-ECHO + DATA bundling during
1375                         * multihoming stale cookie scenarios, the following
1376                         * command plays with asoc->peer.retran_path to
1377                         * avoid the problem of sending the COOKIE-ECHO and
1378                         * DATA in different paths, which could result
1379                         * in the association being ABORTed if the DATA chunk
1380                         * is processed first by the server.  Checking the
1381                         * init error counter simply causes this command
1382                         * to be executed only during failed attempts of
1383                         * association establishment.
1384                         */
1385                        if ((asoc->peer.retran_path !=
1386                             asoc->peer.primary_path) &&
1387                            (asoc->init_err_counter > 0)) {
1388                                sctp_add_cmd_sf(commands,
1389                                                SCTP_CMD_FORCE_PRIM_RETRAN,
1390                                                SCTP_NULL());
1391                        }
1392
1393                        break;
1394
1395                case SCTP_CMD_GEN_SHUTDOWN:
1396                        /* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1397                         * Reset error counts.
1398                         */
1399                        asoc->overall_error_count = 0;
1400
1401                        /* Generate a SHUTDOWN chunk.  */
1402                        new_obj = sctp_make_shutdown(asoc, chunk);
1403                        if (!new_obj)
1404                                goto nomem;
1405                        sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1406                                        SCTP_CHUNK(new_obj));
1407                        break;
1408
1409                case SCTP_CMD_CHUNK_ULP:
1410                        /* Send a chunk to the sockets layer.  */
1411                        SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1412                                          "chunk_up:", cmd->obj.ptr,
1413                                          "ulpq:", &asoc->ulpq);
1414                        sctp_ulpq_tail_data(&asoc->ulpq, cmd->obj.ptr,
1415                                            GFP_ATOMIC);
1416                        break;
1417
1418                case SCTP_CMD_EVENT_ULP:
1419                        /* Send a notification to the sockets layer.  */
1420                        SCTP_DEBUG_PRINTK("sm_sideff: %s %p, %s %p.\n",
1421                                          "event_up:",cmd->obj.ptr,
1422                                          "ulpq:",&asoc->ulpq);
1423                        sctp_ulpq_tail_event(&asoc->ulpq, cmd->obj.ptr);
1424                        break;
1425
1426                case SCTP_CMD_REPLY:
1427                        /* If an caller has not already corked, do cork. */
1428                        if (!asoc->outqueue.cork) {
1429                                sctp_outq_cork(&asoc->outqueue);
1430                                local_cork = 1;
1431                        }
1432                        /* Send a chunk to our peer.  */
1433                        error = sctp_outq_tail(&asoc->outqueue, cmd->obj.ptr);
1434                        break;
1435
1436                case SCTP_CMD_SEND_PKT:
1437                        /* Send a full packet to our peer.  */
1438                        packet = cmd->obj.ptr;
1439                        sctp_packet_transmit(packet);
1440                        sctp_ootb_pkt_free(packet);
1441                        break;
1442
1443                case SCTP_CMD_T1_RETRAN:
1444                        /* Mark a transport for retransmission.  */
1445                        sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1446                                        SCTP_RTXR_T1_RTX);
1447                        break;
1448
1449                case SCTP_CMD_RETRAN:
1450                        /* Mark a transport for retransmission.  */
1451                        sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1452                                        SCTP_RTXR_T3_RTX);
1453                        break;
1454
1455                case SCTP_CMD_ECN_CE:
1456                        /* Do delayed CE processing.   */
1457                        sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1458                        break;
1459
1460                case SCTP_CMD_ECN_ECNE:
1461                        /* Do delayed ECNE processing. */
1462                        new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1463                                                        chunk);
1464                        if (new_obj)
1465                                sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1466                                                SCTP_CHUNK(new_obj));
1467                        break;
1468
1469                case SCTP_CMD_ECN_CWR:
1470                        /* Do delayed CWR processing.  */
1471                        sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1472                        break;
1473
1474                case SCTP_CMD_SETUP_T2:
1475                        sctp_cmd_setup_t2(commands, asoc, cmd->obj.ptr);
1476                        break;
1477
1478                case SCTP_CMD_TIMER_START_ONCE:
1479                        timer = &asoc->timers[cmd->obj.to];
1480
1481                        if (timer_pending(timer))
1482                                break;
1483                        /* fall through */
1484
1485                case SCTP_CMD_TIMER_START:
1486                        timer = &asoc->timers[cmd->obj.to];
1487                        timeout = asoc->timeouts[cmd->obj.to];
1488                        BUG_ON(!timeout);
1489
1490                        timer->expires = jiffies + timeout;
1491                        sctp_association_hold(asoc);
1492                        add_timer(timer);
1493                        break;
1494
1495                case SCTP_CMD_TIMER_RESTART:
1496                        timer = &asoc->timers[cmd->obj.to];
1497                        timeout = asoc->timeouts[cmd->obj.to];
1498                        if (!mod_timer(timer, jiffies + timeout))
1499                                sctp_association_hold(asoc);
1500                        break;
1501
1502                case SCTP_CMD_TIMER_STOP:
1503                        timer = &asoc->timers[cmd->obj.to];
1504                        if (timer_pending(timer) && del_timer(timer))
1505                                sctp_association_put(asoc);
1506                        break;
1507
1508                case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1509                        chunk = cmd->obj.ptr;
1510                        t = sctp_assoc_choose_alter_transport(asoc,
1511                                                asoc->init_last_sent_to);
1512                        asoc->init_last_sent_to = t;
1513                        chunk->transport = t;
1514                        t->init_sent_count++;
1515                        /* Set the new transport as primary */
1516                        sctp_assoc_set_primary(asoc, t);
1517                        break;
1518
1519                case SCTP_CMD_INIT_RESTART:
1520                        /* Do the needed accounting and updates
1521                         * associated with restarting an initialization
1522                         * timer. Only multiply the timeout by two if
1523                         * all transports have been tried at the current
1524                         * timeout.
1525                         */
1526                        sctp_cmd_t1_timer_update(asoc,
1527                                                SCTP_EVENT_TIMEOUT_T1_INIT,
1528                                                "INIT");
1529
1530                        sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1531                                        SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1532                        break;
1533
1534                case SCTP_CMD_COOKIEECHO_RESTART:
1535                        /* Do the needed accounting and updates
1536                         * associated with restarting an initialization
1537                         * timer. Only multiply the timeout by two if
1538                         * all transports have been tried at the current
1539                         * timeout.
1540                         */
1541                        sctp_cmd_t1_timer_update(asoc,
1542                                                SCTP_EVENT_TIMEOUT_T1_COOKIE,
1543                                                "COOKIE");
1544
1545                        /* If we've sent any data bundled with
1546                         * COOKIE-ECHO we need to resend.
1547                         */
1548                        list_for_each_entry(t, &asoc->peer.transport_addr_list,
1549                                        transports) {
1550                                sctp_retransmit_mark(&asoc->outqueue, t,
1551                                            SCTP_RTXR_T1_RTX);
1552                        }
1553
1554                        sctp_add_cmd_sf(commands,
1555                                        SCTP_CMD_TIMER_RESTART,
1556                                        SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1557                        break;
1558
1559                case SCTP_CMD_INIT_FAILED:
1560                        sctp_cmd_init_failed(commands, asoc, cmd->obj.err);
1561                        break;
1562
1563                case SCTP_CMD_ASSOC_FAILED:
1564                        sctp_cmd_assoc_failed(commands, asoc, event_type,
1565                                              subtype, chunk, cmd->obj.err);
1566                        break;
1567
1568                case SCTP_CMD_INIT_COUNTER_INC:
1569                        asoc->init_err_counter++;
1570                        break;
1571
1572                case SCTP_CMD_INIT_COUNTER_RESET:
1573                        asoc->init_err_counter = 0;
1574                        asoc->init_cycle = 0;
1575                        list_for_each_entry(t, &asoc->peer.transport_addr_list,
1576                                            transports) {
1577                                t->init_sent_count = 0;
1578                        }
1579                        break;
1580
1581                case SCTP_CMD_REPORT_DUP:
1582                        sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1583                                             cmd->obj.u32);
1584                        break;
1585
1586                case SCTP_CMD_REPORT_BAD_TAG:
1587                        SCTP_DEBUG_PRINTK("vtag mismatch!\n");
1588                        break;
1589
1590                case SCTP_CMD_STRIKE:
1591                        /* Mark one strike against a transport.  */
1592                        sctp_do_8_2_transport_strike(commands, asoc,
1593                                                    cmd->obj.transport, 0);
1594                        break;
1595
1596                case SCTP_CMD_TRANSPORT_IDLE:
1597                        t = cmd->obj.transport;
1598                        sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
1599                        break;
1600
1601                case SCTP_CMD_TRANSPORT_HB_SENT:
1602                        t = cmd->obj.transport;
1603                        sctp_do_8_2_transport_strike(commands, asoc,
1604                                                     t, 1);
1605                        t->hb_sent = 1;
1606                        break;
1607
1608                case SCTP_CMD_TRANSPORT_ON:
1609                        t = cmd->obj.transport;
1610                        sctp_cmd_transport_on(commands, asoc, t, chunk);
1611                        break;
1612
1613                case SCTP_CMD_HB_TIMERS_START:
1614                        sctp_cmd_hb_timers_start(commands, asoc);
1615                        break;
1616
1617                case SCTP_CMD_HB_TIMER_UPDATE:
1618                        t = cmd->obj.transport;
1619                        sctp_cmd_hb_timer_update(commands, t);
1620                        break;
1621
1622                case SCTP_CMD_HB_TIMERS_STOP:
1623                        sctp_cmd_hb_timers_stop(commands, asoc);
1624                        break;
1625
1626                case SCTP_CMD_REPORT_ERROR:
1627                        error = cmd->obj.error;
1628                        break;
1629
1630                case SCTP_CMD_PROCESS_CTSN:
1631                        /* Dummy up a SACK for processing. */
1632                        sackh.cum_tsn_ack = cmd->obj.be32;
1633                        sackh.a_rwnd = asoc->peer.rwnd +
1634                                        asoc->outqueue.outstanding_bytes;
1635                        sackh.num_gap_ack_blocks = 0;
1636                        sackh.num_dup_tsns = 0;
1637                        sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1638                                        SCTP_SACKH(&sackh));
1639                        break;
1640
1641                case SCTP_CMD_DISCARD_PACKET:
1642                        /* We need to discard the whole packet.
1643                         * Uncork the queue since there might be
1644                         * responses pending
1645                         */
1646                        chunk->pdiscard = 1;
1647                        if (asoc) {
1648                                sctp_outq_uncork(&asoc->outqueue);
1649                                local_cork = 0;
1650                        }
1651                        break;
1652
1653                case SCTP_CMD_RTO_PENDING:
1654                        t = cmd->obj.transport;
1655                        t->rto_pending = 1;
1656                        break;
1657
1658                case SCTP_CMD_PART_DELIVER:
1659                        sctp_ulpq_partial_delivery(&asoc->ulpq, cmd->obj.ptr,
1660                                                   GFP_ATOMIC);
1661                        break;
1662
1663                case SCTP_CMD_RENEGE:
1664                        sctp_ulpq_renege(&asoc->ulpq, cmd->obj.ptr,
1665                                         GFP_ATOMIC);
1666                        break;
1667
1668                case SCTP_CMD_SETUP_T4:
1669                        sctp_cmd_setup_t4(commands, asoc, cmd->obj.ptr);
1670                        break;
1671
1672                case SCTP_CMD_PROCESS_OPERR:
1673                        sctp_cmd_process_operr(commands, asoc, chunk);
1674                        break;
1675                case SCTP_CMD_CLEAR_INIT_TAG:
1676                        asoc->peer.i.init_tag = 0;
1677                        break;
1678                case SCTP_CMD_DEL_NON_PRIMARY:
1679                        sctp_cmd_del_non_primary(asoc);
1680                        break;
1681                case SCTP_CMD_T3_RTX_TIMERS_STOP:
1682                        sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1683                        break;
1684                case SCTP_CMD_FORCE_PRIM_RETRAN:
1685                        t = asoc->peer.retran_path;
1686                        asoc->peer.retran_path = asoc->peer.primary_path;
1687                        error = sctp_outq_uncork(&asoc->outqueue);
1688                        local_cork = 0;
1689                        asoc->peer.retran_path = t;
1690                        break;
1691                case SCTP_CMD_SET_SK_ERR:
1692                        sctp_cmd_set_sk_err(asoc, cmd->obj.error);
1693                        break;
1694                case SCTP_CMD_ASSOC_CHANGE:
1695                        sctp_cmd_assoc_change(commands, asoc,
1696                                              cmd->obj.u8);
1697                        break;
1698                case SCTP_CMD_ADAPTATION_IND:
1699                        sctp_cmd_adaptation_ind(commands, asoc);
1700                        break;
1701
1702                case SCTP_CMD_ASSOC_SHKEY:
1703                        error = sctp_auth_asoc_init_active_key(asoc,
1704                                                GFP_ATOMIC);
1705                        break;
1706                case SCTP_CMD_UPDATE_INITTAG:
1707                        asoc->peer.i.init_tag = cmd->obj.u32;
1708                        break;
1709                case SCTP_CMD_SEND_MSG:
1710                        if (!asoc->outqueue.cork) {
1711                                sctp_outq_cork(&asoc->outqueue);
1712                                local_cork = 1;
1713                        }
1714                        error = sctp_cmd_send_msg(asoc, cmd->obj.msg);
1715                        break;
1716                case SCTP_CMD_SEND_NEXT_ASCONF:
1717                        sctp_cmd_send_asconf(asoc);
1718                        break;
1719                case SCTP_CMD_PURGE_ASCONF_QUEUE:
1720                        sctp_asconf_queue_teardown(asoc);
1721                        break;
1722
1723                case SCTP_CMD_SET_ASOC:
1724                        asoc = cmd->obj.asoc;
1725                        break;
1726
1727                default:
1728                        pr_warn("Impossible command: %u, %p\n",
1729                                cmd->verb, cmd->obj.ptr);
1730                        break;
1731                }
1732
1733                if (error)
1734                        break;
1735        }
1736
1737out:
1738        /* If this is in response to a received chunk, wait until
1739         * we are done with the packet to open the queue so that we don't
1740         * send multiple packets in response to a single request.
1741         */
1742        if (asoc && SCTP_EVENT_T_CHUNK == event_type && chunk) {
1743                if (chunk->end_of_packet || chunk->singleton)
1744                        error = sctp_outq_uncork(&asoc->outqueue);
1745        } else if (local_cork)
1746                error = sctp_outq_uncork(&asoc->outqueue);
1747        return error;
1748nomem:
1749        error = -ENOMEM;
1750        goto out;
1751}
1752
1753
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