sm_sideeffect.c

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/* SCTP kernel implementation
   3 * (C) Copyright IBM Corp. 2001, 2004
   4 * Copyright (c) 1999 Cisco, Inc.
   5 * Copyright (c) 1999-2001 Motorola, Inc.
   6 *
   7 * This file is part of the SCTP kernel implementation
   8 *
   9 * These functions work with the state functions in sctp_sm_statefuns.c
  10 * to implement that state operations.  These functions implement the
  11 * steps which require modifying existing data structures.
  12 *
  13 * Please send any bug reports or fixes you make to the
  14 * email address(es):
  15 *    lksctp developers <linux-sctp@vger.kernel.org>
  16 *
  17 * Written or modified by:
  18 *    La Monte H.P. Yarroll <piggy@acm.org>
  19 *    Karl Knutson          <karl@athena.chicago.il.us>
  20 *    Jon Grimm             <jgrimm@austin.ibm.com>
  21 *    Hui Huang		    <hui.huang@nokia.com>
  22 *    Dajiang Zhang	    <dajiang.zhang@nokia.com>
  23 *    Daisy Chang	    <daisyc@us.ibm.com>
  24 *    Sridhar Samudrala	    <sri@us.ibm.com>
  25 *    Ardelle Fan	    <ardelle.fan@intel.com>
  26 */
  27
  28#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  29
  30#include <linux/skbuff.h>
  31#include <linux/types.h>
  32#include <linux/socket.h>
  33#include <linux/ip.h>
  34#include <linux/gfp.h>
  35#include <net/sock.h>
  36#include <net/sctp/sctp.h>
  37#include <net/sctp/sm.h>
  38#include <net/sctp/stream_sched.h>
  39
  40static int sctp_cmd_interpreter(enum sctp_event_type event_type,
  41				union sctp_subtype subtype,
  42				enum sctp_state state,
  43				struct sctp_endpoint *ep,
  44				struct sctp_association *asoc,
  45				void *event_arg,
  46				enum sctp_disposition status,
  47				struct sctp_cmd_seq *commands,
  48				gfp_t gfp);
  49static int sctp_side_effects(enum sctp_event_type event_type,
  50			     union sctp_subtype subtype,
  51			     enum sctp_state state,
  52			     struct sctp_endpoint *ep,
  53			     struct sctp_association **asoc,
  54			     void *event_arg,
  55			     enum sctp_disposition status,
  56			     struct sctp_cmd_seq *commands,
  57			     gfp_t gfp);
  58
  59/********************************************************************
  60 * Helper functions
  61 ********************************************************************/
  62
  63/* A helper function for delayed processing of INET ECN CE bit. */
  64static void sctp_do_ecn_ce_work(struct sctp_association *asoc,
  65				__u32 lowest_tsn)
  66{
  67	/* Save the TSN away for comparison when we receive CWR */
  68
  69	asoc->last_ecne_tsn = lowest_tsn;
  70	asoc->need_ecne = 1;
  71}
  72
  73/* Helper function for delayed processing of SCTP ECNE chunk.  */
  74/* RFC 2960 Appendix A
  75 *
  76 * RFC 2481 details a specific bit for a sender to send in
  77 * the header of its next outbound TCP segment to indicate to
  78 * its peer that it has reduced its congestion window.  This
  79 * is termed the CWR bit.  For SCTP the same indication is made
  80 * by including the CWR chunk.  This chunk contains one data
  81 * element, i.e. the TSN number that was sent in the ECNE chunk.
  82 * This element represents the lowest TSN number in the datagram
  83 * that was originally marked with the CE bit.
  84 */
  85static struct sctp_chunk *sctp_do_ecn_ecne_work(struct sctp_association *asoc,
  86						__u32 lowest_tsn,
  87						struct sctp_chunk *chunk)
  88{
  89	struct sctp_chunk *repl;
  90
  91	/* Our previously transmitted packet ran into some congestion
  92	 * so we should take action by reducing cwnd and ssthresh
  93	 * and then ACK our peer that we we've done so by
  94	 * sending a CWR.
  95	 */
  96
  97	/* First, try to determine if we want to actually lower
  98	 * our cwnd variables.  Only lower them if the ECNE looks more
  99	 * recent than the last response.
 100	 */
 101	if (TSN_lt(asoc->last_cwr_tsn, lowest_tsn)) {
 102		struct sctp_transport *transport;
 103
 104		/* Find which transport's congestion variables
 105		 * need to be adjusted.
 106		 */
 107		transport = sctp_assoc_lookup_tsn(asoc, lowest_tsn);
 108
 109		/* Update the congestion variables. */
 110		if (transport)
 111			sctp_transport_lower_cwnd(transport,
 112						  SCTP_LOWER_CWND_ECNE);
 113		asoc->last_cwr_tsn = lowest_tsn;
 114	}
 115
 116	/* Always try to quiet the other end.  In case of lost CWR,
 117	 * resend last_cwr_tsn.
 118	 */
 119	repl = sctp_make_cwr(asoc, asoc->last_cwr_tsn, chunk);
 120
 121	/* If we run out of memory, it will look like a lost CWR.  We'll
 122	 * get back in sync eventually.
 123	 */
 124	return repl;
 125}
 126
 127/* Helper function to do delayed processing of ECN CWR chunk.  */
 128static void sctp_do_ecn_cwr_work(struct sctp_association *asoc,
 129				 __u32 lowest_tsn)
 130{
 131	/* Turn off ECNE getting auto-prepended to every outgoing
 132	 * packet
 133	 */
 134	asoc->need_ecne = 0;
 135}
 136
 137/* Generate SACK if necessary.  We call this at the end of a packet.  */
 138static int sctp_gen_sack(struct sctp_association *asoc, int force,
 139			 struct sctp_cmd_seq *commands)
 140{
 141	struct sctp_transport *trans = asoc->peer.last_data_from;
 142	__u32 ctsn, max_tsn_seen;
 143	struct sctp_chunk *sack;
 144	int error = 0;
 145
 146	if (force ||
 147	    (!trans && (asoc->param_flags & SPP_SACKDELAY_DISABLE)) ||
 148	    (trans && (trans->param_flags & SPP_SACKDELAY_DISABLE)))
 149		asoc->peer.sack_needed = 1;
 150
 151	ctsn = sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map);
 152	max_tsn_seen = sctp_tsnmap_get_max_tsn_seen(&asoc->peer.tsn_map);
 153
 154	/* From 12.2 Parameters necessary per association (i.e. the TCB):
 155	 *
 156	 * Ack State : This flag indicates if the next received packet
 157	 * 	     : is to be responded to with a SACK. ...
 158	 *	     : When DATA chunks are out of order, SACK's
 159	 *           : are not delayed (see Section 6).
 160	 *
 161	 * [This is actually not mentioned in Section 6, but we
 162	 * implement it here anyway. --piggy]
 163	 */
 164	if (max_tsn_seen != ctsn)
 165		asoc->peer.sack_needed = 1;
 166
 167	/* From 6.2  Acknowledgement on Reception of DATA Chunks:
 168	 *
 169	 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically,
 170	 * an acknowledgement SHOULD be generated for at least every
 171	 * second packet (not every second DATA chunk) received, and
 172	 * SHOULD be generated within 200 ms of the arrival of any
 173	 * unacknowledged DATA chunk. ...
 174	 */
 175	if (!asoc->peer.sack_needed) {
 176		asoc->peer.sack_cnt++;
 177
 178		/* Set the SACK delay timeout based on the
 179		 * SACK delay for the last transport
 180		 * data was received from, or the default
 181		 * for the association.
 182		 */
 183		if (trans) {
 184			/* We will need a SACK for the next packet.  */
 185			if (asoc->peer.sack_cnt >= trans->sackfreq - 1)
 186				asoc->peer.sack_needed = 1;
 187
 188			asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
 189				trans->sackdelay;
 190		} else {
 191			/* We will need a SACK for the next packet.  */
 192			if (asoc->peer.sack_cnt >= asoc->sackfreq - 1)
 193				asoc->peer.sack_needed = 1;
 194
 195			asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] =
 196				asoc->sackdelay;
 197		}
 198
 199		/* Restart the SACK timer. */
 200		sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
 201				SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
 202	} else {
 203		__u32 old_a_rwnd = asoc->a_rwnd;
 204
 205		asoc->a_rwnd = asoc->rwnd;
 206		sack = sctp_make_sack(asoc);
 207		if (!sack) {
 208			asoc->a_rwnd = old_a_rwnd;
 209			goto nomem;
 210		}
 211
 212		asoc->peer.sack_needed = 0;
 213		asoc->peer.sack_cnt = 0;
 214
 215		sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(sack));
 216
 217		/* Stop the SACK timer.  */
 218		sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
 219				SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
 220	}
 221
 222	return error;
 223nomem:
 224	error = -ENOMEM;
 225	return error;
 226}
 227
 228/* When the T3-RTX timer expires, it calls this function to create the
 229 * relevant state machine event.
 230 */
 231void sctp_generate_t3_rtx_event(struct timer_list *t)
 232{
 233	struct sctp_transport *transport =
 234		timer_container_of(transport, t, T3_rtx_timer);
 235	struct sctp_association *asoc = transport->asoc;
 236	struct sock *sk = asoc->base.sk;
 237	struct net *net = sock_net(sk);
 238	int error;
 239
 240	/* Check whether a task is in the sock.  */
 241
 242	bh_lock_sock(sk);
 243	if (sock_owned_by_user(sk)) {
 244		pr_debug("%s: sock is busy\n", __func__);
 245
 246		/* Try again later.  */
 247		if (!mod_timer(&transport->T3_rtx_timer, jiffies + (HZ/20)))
 248			sctp_transport_hold(transport);
 249		goto out_unlock;
 250	}
 251
 252	/* Run through the state machine.  */
 253	error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
 254			   SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_T3_RTX),
 255			   asoc->state,
 256			   asoc->ep, asoc,
 257			   transport, GFP_ATOMIC);
 258
 259	if (error)
 260		sk->sk_err = -error;
 261
 262out_unlock:
 263	bh_unlock_sock(sk);
 264	sctp_transport_put(transport);
 265}
 266
 267/* This is a sa interface for producing timeout events.  It works
 268 * for timeouts which use the association as their parameter.
 269 */
 270static void sctp_generate_timeout_event(struct sctp_association *asoc,
 271					enum sctp_event_timeout timeout_type)
 272{
 273	struct sock *sk = asoc->base.sk;
 274	struct net *net = sock_net(sk);
 275	int error = 0;
 276
 277	bh_lock_sock(sk);
 278	if (sock_owned_by_user(sk)) {
 279		pr_debug("%s: sock is busy: timer %d\n", __func__,
 280			 timeout_type);
 281
 282		/* Try again later.  */
 283		if (!mod_timer(&asoc->timers[timeout_type], jiffies + (HZ/20)))
 284			sctp_association_hold(asoc);
 285		goto out_unlock;
 286	}
 287
 288	/* Is this association really dead and just waiting around for
 289	 * the timer to let go of the reference?
 290	 */
 291	if (asoc->base.dead)
 292		goto out_unlock;
 293
 294	/* Run through the state machine.  */
 295	error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
 296			   SCTP_ST_TIMEOUT(timeout_type),
 297			   asoc->state, asoc->ep, asoc,
 298			   (void *)timeout_type, GFP_ATOMIC);
 299
 300	if (error)
 301		sk->sk_err = -error;
 302
 303out_unlock:
 304	bh_unlock_sock(sk);
 305	sctp_association_put(asoc);
 306}
 307
 308static void sctp_generate_t1_cookie_event(struct timer_list *t)
 309{
 310	struct sctp_association *asoc =
 311		timer_container_of(asoc, t,
 312				   timers[SCTP_EVENT_TIMEOUT_T1_COOKIE]);
 313
 314	sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_COOKIE);
 315}
 316
 317static void sctp_generate_t1_init_event(struct timer_list *t)
 318{
 319	struct sctp_association *asoc =
 320		timer_container_of(asoc, t,
 321				   timers[SCTP_EVENT_TIMEOUT_T1_INIT]);
 322
 323	sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T1_INIT);
 324}
 325
 326static void sctp_generate_t2_shutdown_event(struct timer_list *t)
 327{
 328	struct sctp_association *asoc =
 329		timer_container_of(asoc, t,
 330				   timers[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN]);
 331
 332	sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T2_SHUTDOWN);
 333}
 334
 335static void sctp_generate_t4_rto_event(struct timer_list *t)
 336{
 337	struct sctp_association *asoc =
 338		timer_container_of(asoc, t, timers[SCTP_EVENT_TIMEOUT_T4_RTO]);
 339
 340	sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_T4_RTO);
 341}
 342
 343static void sctp_generate_t5_shutdown_guard_event(struct timer_list *t)
 344{
 345	struct sctp_association *asoc =
 346		timer_container_of(asoc, t,
 347				   timers[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD]);
 348
 349	sctp_generate_timeout_event(asoc,
 350				    SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD);
 351
 352} /* sctp_generate_t5_shutdown_guard_event() */
 353
 354static void sctp_generate_autoclose_event(struct timer_list *t)
 355{
 356	struct sctp_association *asoc =
 357		timer_container_of(asoc, t,
 358				   timers[SCTP_EVENT_TIMEOUT_AUTOCLOSE]);
 359
 360	sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_AUTOCLOSE);
 361}
 362
 363/* Generate a heart beat event.  If the sock is busy, reschedule.   Make
 364 * sure that the transport is still valid.
 365 */
 366void sctp_generate_heartbeat_event(struct timer_list *t)
 367{
 368	struct sctp_transport *transport = timer_container_of(transport, t,
 369							      hb_timer);
 370	struct sctp_association *asoc = transport->asoc;
 371	struct sock *sk = asoc->base.sk;
 372	struct net *net = sock_net(sk);
 373	u32 elapsed, timeout;
 374	int error = 0;
 375
 376	bh_lock_sock(sk);
 377	if (sock_owned_by_user(sk)) {
 378		pr_debug("%s: sock is busy\n", __func__);
 379
 380		/* Try again later.  */
 381		if (!mod_timer(&transport->hb_timer, jiffies + (HZ/20)))
 382			sctp_transport_hold(transport);
 383		goto out_unlock;
 384	}
 385
 386	/* Check if we should still send the heartbeat or reschedule */
 387	elapsed = jiffies - transport->last_time_sent;
 388	timeout = sctp_transport_timeout(transport);
 389	if (elapsed < timeout) {
 390		elapsed = timeout - elapsed;
 391		if (!mod_timer(&transport->hb_timer, jiffies + elapsed))
 392			sctp_transport_hold(transport);
 393		goto out_unlock;
 394	}
 395
 396	error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
 397			   SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_HEARTBEAT),
 398			   asoc->state, asoc->ep, asoc,
 399			   transport, GFP_ATOMIC);
 400
 401	if (error)
 402		sk->sk_err = -error;
 403
 404out_unlock:
 405	bh_unlock_sock(sk);
 406	sctp_transport_put(transport);
 407}
 408
 409/* Handle the timeout of the ICMP protocol unreachable timer.  Trigger
 410 * the correct state machine transition that will close the association.
 411 */
 412void sctp_generate_proto_unreach_event(struct timer_list *t)
 413{
 414	struct sctp_transport *transport =
 415		timer_container_of(transport, t, proto_unreach_timer);
 416	struct sctp_association *asoc = transport->asoc;
 417	struct sock *sk = asoc->base.sk;
 418	struct net *net = sock_net(sk);
 419
 420	bh_lock_sock(sk);
 421	if (sock_owned_by_user(sk)) {
 422		pr_debug("%s: sock is busy\n", __func__);
 423
 424		/* Try again later.  */
 425		if (!mod_timer(&transport->proto_unreach_timer,
 426				jiffies + (HZ/20)))
 427			sctp_transport_hold(transport);
 428		goto out_unlock;
 429	}
 430
 431	/* Is this structure just waiting around for us to actually
 432	 * get destroyed?
 433	 */
 434	if (asoc->base.dead)
 435		goto out_unlock;
 436
 437	sctp_do_sm(net, SCTP_EVENT_T_OTHER,
 438		   SCTP_ST_OTHER(SCTP_EVENT_ICMP_PROTO_UNREACH),
 439		   asoc->state, asoc->ep, asoc, transport, GFP_ATOMIC);
 440
 441out_unlock:
 442	bh_unlock_sock(sk);
 443	sctp_transport_put(transport);
 444}
 445
 446 /* Handle the timeout of the RE-CONFIG timer. */
 447void sctp_generate_reconf_event(struct timer_list *t)
 448{
 449	struct sctp_transport *transport =
 450		timer_container_of(transport, t, reconf_timer);
 451	struct sctp_association *asoc = transport->asoc;
 452	struct sock *sk = asoc->base.sk;
 453	struct net *net = sock_net(sk);
 454	int error = 0;
 455
 456	bh_lock_sock(sk);
 457	if (sock_owned_by_user(sk)) {
 458		pr_debug("%s: sock is busy\n", __func__);
 459
 460		/* Try again later.  */
 461		if (!mod_timer(&transport->reconf_timer, jiffies + (HZ / 20)))
 462			sctp_transport_hold(transport);
 463		goto out_unlock;
 464	}
 465
 466	/* This happens when the response arrives after the timer is triggered. */
 467	if (!asoc->strreset_chunk)
 468		goto out_unlock;
 469
 470	error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
 471			   SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_RECONF),
 472			   asoc->state, asoc->ep, asoc,
 473			   transport, GFP_ATOMIC);
 474
 475	if (error)
 476		sk->sk_err = -error;
 477
 478out_unlock:
 479	bh_unlock_sock(sk);
 480	sctp_transport_put(transport);
 481}
 482
 483/* Handle the timeout of the probe timer. */
 484void sctp_generate_probe_event(struct timer_list *t)
 485{
 486	struct sctp_transport *transport = timer_container_of(transport, t,
 487							      probe_timer);
 488	struct sctp_association *asoc = transport->asoc;
 489	struct sock *sk = asoc->base.sk;
 490	struct net *net = sock_net(sk);
 491	int error = 0;
 492
 493	bh_lock_sock(sk);
 494	if (sock_owned_by_user(sk)) {
 495		pr_debug("%s: sock is busy\n", __func__);
 496
 497		/* Try again later.  */
 498		if (!mod_timer(&transport->probe_timer, jiffies + (HZ / 20)))
 499			sctp_transport_hold(transport);
 500		goto out_unlock;
 501	}
 502
 503	error = sctp_do_sm(net, SCTP_EVENT_T_TIMEOUT,
 504			   SCTP_ST_TIMEOUT(SCTP_EVENT_TIMEOUT_PROBE),
 505			   asoc->state, asoc->ep, asoc,
 506			   transport, GFP_ATOMIC);
 507
 508	if (error)
 509		sk->sk_err = -error;
 510
 511out_unlock:
 512	bh_unlock_sock(sk);
 513	sctp_transport_put(transport);
 514}
 515
 516/* Inject a SACK Timeout event into the state machine.  */
 517static void sctp_generate_sack_event(struct timer_list *t)
 518{
 519	struct sctp_association *asoc =
 520		timer_container_of(asoc, t, timers[SCTP_EVENT_TIMEOUT_SACK]);
 521
 522	sctp_generate_timeout_event(asoc, SCTP_EVENT_TIMEOUT_SACK);
 523}
 524
 525sctp_timer_event_t *sctp_timer_events[SCTP_NUM_TIMEOUT_TYPES] = {
 526	[SCTP_EVENT_TIMEOUT_NONE] =		NULL,
 527	[SCTP_EVENT_TIMEOUT_T1_COOKIE] =	sctp_generate_t1_cookie_event,
 528	[SCTP_EVENT_TIMEOUT_T1_INIT] =		sctp_generate_t1_init_event,
 529	[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] =	sctp_generate_t2_shutdown_event,
 530	[SCTP_EVENT_TIMEOUT_T3_RTX] =		NULL,
 531	[SCTP_EVENT_TIMEOUT_T4_RTO] =		sctp_generate_t4_rto_event,
 532	[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD] =
 533					sctp_generate_t5_shutdown_guard_event,
 534	[SCTP_EVENT_TIMEOUT_HEARTBEAT] =	NULL,
 535	[SCTP_EVENT_TIMEOUT_RECONF] =		NULL,
 536	[SCTP_EVENT_TIMEOUT_SACK] =		sctp_generate_sack_event,
 537	[SCTP_EVENT_TIMEOUT_AUTOCLOSE] =	sctp_generate_autoclose_event,
 538};
 539
 540
 541/* RFC 2960 8.2 Path Failure Detection
 542 *
 543 * When its peer endpoint is multi-homed, an endpoint should keep a
 544 * error counter for each of the destination transport addresses of the
 545 * peer endpoint.
 546 *
 547 * Each time the T3-rtx timer expires on any address, or when a
 548 * HEARTBEAT sent to an idle address is not acknowledged within a RTO,
 549 * the error counter of that destination address will be incremented.
 550 * When the value in the error counter exceeds the protocol parameter
 551 * 'Path.Max.Retrans' of that destination address, the endpoint should
 552 * mark the destination transport address as inactive, and a
 553 * notification SHOULD be sent to the upper layer.
 554 *
 555 */
 556static void sctp_do_8_2_transport_strike(struct sctp_cmd_seq *commands,
 557					 struct sctp_association *asoc,
 558					 struct sctp_transport *transport,
 559					 int is_hb)
 560{
 561	/* The check for association's overall error counter exceeding the
 562	 * threshold is done in the state function.
 563	 */
 564	/* We are here due to a timer expiration.  If the timer was
 565	 * not a HEARTBEAT, then normal error tracking is done.
 566	 * If the timer was a heartbeat, we only increment error counts
 567	 * when we already have an outstanding HEARTBEAT that has not
 568	 * been acknowledged.
 569	 * Additionally, some tranport states inhibit error increments.
 570	 */
 571	if (!is_hb) {
 572		asoc->overall_error_count++;
 573		if (transport->state != SCTP_INACTIVE)
 574			transport->error_count++;
 575	 } else if (transport->hb_sent) {
 576		if (transport->state != SCTP_UNCONFIRMED)
 577			asoc->overall_error_count++;
 578		if (transport->state != SCTP_INACTIVE)
 579			transport->error_count++;
 580	}
 581
 582	/* If the transport error count is greater than the pf_retrans
 583	 * threshold, and less than pathmaxrtx, and if the current state
 584	 * is SCTP_ACTIVE, then mark this transport as Partially Failed,
 585	 * see SCTP Quick Failover Draft, section 5.1
 586	 */
 587	if (asoc->base.net->sctp.pf_enable &&
 588	    transport->state == SCTP_ACTIVE &&
 589	    transport->error_count < transport->pathmaxrxt &&
 590	    transport->error_count > transport->pf_retrans) {
 591
 592		sctp_assoc_control_transport(asoc, transport,
 593					     SCTP_TRANSPORT_PF,
 594					     0);
 595
 596		/* Update the hb timer to resend a heartbeat every rto */
 597		sctp_transport_reset_hb_timer(transport);
 598	}
 599
 600	if (transport->state != SCTP_INACTIVE &&
 601	    (transport->error_count > transport->pathmaxrxt)) {
 602		pr_debug("%s: association:%p transport addr:%pISpc failed\n",
 603			 __func__, asoc, &transport->ipaddr.sa);
 604
 605		sctp_assoc_control_transport(asoc, transport,
 606					     SCTP_TRANSPORT_DOWN,
 607					     SCTP_FAILED_THRESHOLD);
 608	}
 609
 610	if (transport->error_count > transport->ps_retrans &&
 611	    asoc->peer.primary_path == transport &&
 612	    asoc->peer.active_path != transport)
 613		sctp_assoc_set_primary(asoc, asoc->peer.active_path);
 614
 615	/* E2) For the destination address for which the timer
 616	 * expires, set RTO <- RTO * 2 ("back off the timer").  The
 617	 * maximum value discussed in rule C7 above (RTO.max) may be
 618	 * used to provide an upper bound to this doubling operation.
 619	 *
 620	 * Special Case:  the first HB doesn't trigger exponential backoff.
 621	 * The first unacknowledged HB triggers it.  We do this with a flag
 622	 * that indicates that we have an outstanding HB.
 623	 */
 624	if (!is_hb || transport->hb_sent) {
 625		transport->rto = min((transport->rto * 2), transport->asoc->rto_max);
 626		sctp_max_rto(asoc, transport);
 627	}
 628}
 629
 630/* Worker routine to handle INIT command failure.  */
 631static void sctp_cmd_init_failed(struct sctp_cmd_seq *commands,
 632				 struct sctp_association *asoc,
 633				 unsigned int error)
 634{
 635	struct sctp_ulpevent *event;
 636
 637	event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_CANT_STR_ASSOC,
 638						(__u16)error, 0, 0, NULL,
 639						GFP_ATOMIC);
 640
 641	if (event)
 642		sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 643				SCTP_ULPEVENT(event));
 644
 645	sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 646			SCTP_STATE(SCTP_STATE_CLOSED));
 647
 648	/* SEND_FAILED sent later when cleaning up the association. */
 649	asoc->outqueue.error = error;
 650	sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 651}
 652
 653/* Worker routine to handle SCTP_CMD_ASSOC_FAILED.  */
 654static void sctp_cmd_assoc_failed(struct sctp_cmd_seq *commands,
 655				  struct sctp_association *asoc,
 656				  enum sctp_event_type event_type,
 657				  union sctp_subtype subtype,
 658				  struct sctp_chunk *chunk,
 659				  unsigned int error)
 660{
 661	struct sctp_ulpevent *event;
 662	struct sctp_chunk *abort;
 663
 664	/* Cancel any partial delivery in progress. */
 665	asoc->stream.si->abort_pd(&asoc->ulpq, GFP_ATOMIC);
 666
 667	if (event_type == SCTP_EVENT_T_CHUNK && subtype.chunk == SCTP_CID_ABORT)
 668		event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
 669						(__u16)error, 0, 0, chunk,
 670						GFP_ATOMIC);
 671	else
 672		event = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_LOST,
 673						(__u16)error, 0, 0, NULL,
 674						GFP_ATOMIC);
 675	if (event)
 676		sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 677				SCTP_ULPEVENT(event));
 678
 679	if (asoc->overall_error_count >= asoc->max_retrans) {
 680		abort = sctp_make_violation_max_retrans(asoc, chunk);
 681		if (abort)
 682			sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
 683					SCTP_CHUNK(abort));
 684	}
 685
 686	sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
 687			SCTP_STATE(SCTP_STATE_CLOSED));
 688
 689	/* SEND_FAILED sent later when cleaning up the association. */
 690	asoc->outqueue.error = error;
 691	sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
 692}
 693
 694/* Process an init chunk (may be real INIT/INIT-ACK or an embedded INIT
 695 * inside the cookie.  In reality, this is only used for INIT-ACK processing
 696 * since all other cases use "temporary" associations and can do all
 697 * their work in statefuns directly.
 698 */
 699static int sctp_cmd_process_init(struct sctp_cmd_seq *commands,
 700				 struct sctp_association *asoc,
 701				 struct sctp_chunk *chunk,
 702				 struct sctp_init_chunk *peer_init,
 703				 gfp_t gfp)
 704{
 705	int error;
 706
 707	/* We only process the init as a sideeffect in a single
 708	 * case.   This is when we process the INIT-ACK.   If we
 709	 * fail during INIT processing (due to malloc problems),
 710	 * just return the error and stop processing the stack.
 711	 */
 712	if (!sctp_process_init(asoc, chunk, sctp_source(chunk), peer_init, gfp))
 713		error = -ENOMEM;
 714	else
 715		error = 0;
 716
 717	return error;
 718}
 719
 720/* Helper function to break out starting up of heartbeat timers.  */
 721static void sctp_cmd_hb_timers_start(struct sctp_cmd_seq *cmds,
 722				     struct sctp_association *asoc)
 723{
 724	struct sctp_transport *t;
 725
 726	/* Start a heartbeat timer for each transport on the association.
 727	 * hold a reference on the transport to make sure none of
 728	 * the needed data structures go away.
 729	 */
 730	list_for_each_entry(t, &asoc->peer.transport_addr_list, transports)
 731		sctp_transport_reset_hb_timer(t);
 732}
 733
 734static void sctp_cmd_hb_timers_stop(struct sctp_cmd_seq *cmds,
 735				    struct sctp_association *asoc)
 736{
 737	struct sctp_transport *t;
 738
 739	/* Stop all heartbeat timers. */
 740
 741	list_for_each_entry(t, &asoc->peer.transport_addr_list,
 742			transports) {
 743		if (timer_delete(&t->hb_timer))
 744			sctp_transport_put(t);
 745	}
 746}
 747
 748/* Helper function to stop any pending T3-RTX timers */
 749static void sctp_cmd_t3_rtx_timers_stop(struct sctp_cmd_seq *cmds,
 750					struct sctp_association *asoc)
 751{
 752	struct sctp_transport *t;
 753
 754	list_for_each_entry(t, &asoc->peer.transport_addr_list,
 755			transports) {
 756		if (timer_delete(&t->T3_rtx_timer))
 757			sctp_transport_put(t);
 758	}
 759}
 760
 761
 762/* Helper function to handle the reception of an HEARTBEAT ACK.  */
 763static void sctp_cmd_transport_on(struct sctp_cmd_seq *cmds,
 764				  struct sctp_association *asoc,
 765				  struct sctp_transport *t,
 766				  struct sctp_chunk *chunk)
 767{
 768	struct sctp_sender_hb_info *hbinfo;
 769	int was_unconfirmed = 0;
 770
 771	/* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of the
 772	 * HEARTBEAT should clear the error counter of the destination
 773	 * transport address to which the HEARTBEAT was sent.
 774	 */
 775	t->error_count = 0;
 776
 777	/*
 778	 * Although RFC4960 specifies that the overall error count must
 779	 * be cleared when a HEARTBEAT ACK is received, we make an
 780	 * exception while in SHUTDOWN PENDING. If the peer keeps its
 781	 * window shut forever, we may never be able to transmit our
 782	 * outstanding data and rely on the retransmission limit be reached
 783	 * to shutdown the association.
 784	 */
 785	if (t->asoc->state < SCTP_STATE_SHUTDOWN_PENDING)
 786		t->asoc->overall_error_count = 0;
 787
 788	/* Clear the hb_sent flag to signal that we had a good
 789	 * acknowledgement.
 790	 */
 791	t->hb_sent = 0;
 792
 793	/* Mark the destination transport address as active if it is not so
 794	 * marked.
 795	 */
 796	if ((t->state == SCTP_INACTIVE) || (t->state == SCTP_UNCONFIRMED)) {
 797		was_unconfirmed = 1;
 798		sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
 799					     SCTP_HEARTBEAT_SUCCESS);
 800	}
 801
 802	if (t->state == SCTP_PF)
 803		sctp_assoc_control_transport(asoc, t, SCTP_TRANSPORT_UP,
 804					     SCTP_HEARTBEAT_SUCCESS);
 805
 806	/* HB-ACK was received for a the proper HB.  Consider this
 807	 * forward progress.
 808	 */
 809	if (t->dst)
 810		sctp_transport_dst_confirm(t);
 811
 812	/* The receiver of the HEARTBEAT ACK should also perform an
 813	 * RTT measurement for that destination transport address
 814	 * using the time value carried in the HEARTBEAT ACK chunk.
 815	 * If the transport's rto_pending variable has been cleared,
 816	 * it was most likely due to a retransmit.  However, we want
 817	 * to re-enable it to properly update the rto.
 818	 */
 819	if (t->rto_pending == 0)
 820		t->rto_pending = 1;
 821
 822	hbinfo = (struct sctp_sender_hb_info *)chunk->skb->data;
 823	sctp_transport_update_rto(t, (jiffies - hbinfo->sent_at));
 824
 825	/* Update the heartbeat timer.  */
 826	sctp_transport_reset_hb_timer(t);
 827
 828	if (was_unconfirmed && asoc->peer.transport_count == 1)
 829		sctp_transport_immediate_rtx(t);
 830}
 831
 832
 833/* Helper function to process the process SACK command.  */
 834static int sctp_cmd_process_sack(struct sctp_cmd_seq *cmds,
 835				 struct sctp_association *asoc,
 836				 struct sctp_chunk *chunk)
 837{
 838	int err = 0;
 839
 840	if (sctp_outq_sack(&asoc->outqueue, chunk)) {
 841		/* There are no more TSNs awaiting SACK.  */
 842		err = sctp_do_sm(asoc->base.net, SCTP_EVENT_T_OTHER,
 843				 SCTP_ST_OTHER(SCTP_EVENT_NO_PENDING_TSN),
 844				 asoc->state, asoc->ep, asoc, NULL,
 845				 GFP_ATOMIC);
 846	}
 847
 848	return err;
 849}
 850
 851/* Helper function to set the timeout value for T2-SHUTDOWN timer and to set
 852 * the transport for a shutdown chunk.
 853 */
 854static void sctp_cmd_setup_t2(struct sctp_cmd_seq *cmds,
 855			      struct sctp_association *asoc,
 856			      struct sctp_chunk *chunk)
 857{
 858	struct sctp_transport *t;
 859
 860	if (chunk->transport)
 861		t = chunk->transport;
 862	else {
 863		t = sctp_assoc_choose_alter_transport(asoc,
 864					      asoc->shutdown_last_sent_to);
 865		chunk->transport = t;
 866	}
 867	asoc->shutdown_last_sent_to = t;
 868	asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = t->rto;
 869}
 870
 871/* Helper function to change the state of an association. */
 872static void sctp_cmd_new_state(struct sctp_cmd_seq *cmds,
 873			       struct sctp_association *asoc,
 874			       enum sctp_state state)
 875{
 876	struct sock *sk = asoc->base.sk;
 877
 878	asoc->state = state;
 879
 880	pr_debug("%s: asoc:%p[%s]\n", __func__, asoc, sctp_state_tbl[state]);
 881
 882	if (sctp_style(sk, TCP)) {
 883		/* Change the sk->sk_state of a TCP-style socket that has
 884		 * successfully completed a connect() call.
 885		 */
 886		if (sctp_state(asoc, ESTABLISHED) && sctp_sstate(sk, CLOSED))
 887			inet_sk_set_state(sk, SCTP_SS_ESTABLISHED);
 888
 889		/* Set the RCV_SHUTDOWN flag when a SHUTDOWN is received. */
 890		if (sctp_state(asoc, SHUTDOWN_RECEIVED) &&
 891		    sctp_sstate(sk, ESTABLISHED)) {
 892			inet_sk_set_state(sk, SCTP_SS_CLOSING);
 893			sk->sk_shutdown |= RCV_SHUTDOWN;
 894		}
 895	}
 896
 897	if (sctp_state(asoc, COOKIE_WAIT)) {
 898		/* Reset init timeouts since they may have been
 899		 * increased due to timer expirations.
 900		 */
 901		asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] =
 902						asoc->rto_initial;
 903		asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] =
 904						asoc->rto_initial;
 905	}
 906
 907	if (sctp_state(asoc, ESTABLISHED)) {
 908		kfree(asoc->peer.cookie);
 909		asoc->peer.cookie = NULL;
 910	}
 911
 912	if (sctp_state(asoc, ESTABLISHED) ||
 913	    sctp_state(asoc, CLOSED) ||
 914	    sctp_state(asoc, SHUTDOWN_RECEIVED)) {
 915		/* Wake up any processes waiting in the asoc's wait queue in
 916		 * sctp_wait_for_connect() or sctp_wait_for_sndbuf().
 917		 */
 918		if (waitqueue_active(&asoc->wait))
 919			wake_up_interruptible(&asoc->wait);
 920
 921		/* Wake up any processes waiting in the sk's sleep queue of
 922		 * a TCP-style or UDP-style peeled-off socket in
 923		 * sctp_wait_for_accept() or sctp_wait_for_packet().
 924		 * For a UDP-style socket, the waiters are woken up by the
 925		 * notifications.
 926		 */
 927		if (!sctp_style(sk, UDP))
 928			sk->sk_state_change(sk);
 929	}
 930
 931	if (sctp_state(asoc, SHUTDOWN_PENDING) &&
 932	    !sctp_outq_is_empty(&asoc->outqueue))
 933		sctp_outq_uncork(&asoc->outqueue, GFP_ATOMIC);
 934}
 935
 936/* Helper function to delete an association. */
 937static void sctp_cmd_delete_tcb(struct sctp_cmd_seq *cmds,
 938				struct sctp_association *asoc)
 939{
 940	struct sock *sk = asoc->base.sk;
 941
 942	/* If it is a non-temporary association belonging to a TCP-style
 943	 * listening socket that is not closed, do not free it so that accept()
 944	 * can pick it up later.
 945	 */
 946	if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING) &&
 947	    (!asoc->temp) && (sk->sk_shutdown != SHUTDOWN_MASK))
 948		return;
 949
 950	sctp_association_free(asoc);
 951}
 952
 953/*
 954 * ADDIP Section 4.1 ASCONF Chunk Procedures
 955 * A4) Start a T-4 RTO timer, using the RTO value of the selected
 956 * destination address (we use active path instead of primary path just
 957 * because primary path may be inactive.
 958 */
 959static void sctp_cmd_setup_t4(struct sctp_cmd_seq *cmds,
 960			      struct sctp_association *asoc,
 961			      struct sctp_chunk *chunk)
 962{
 963	struct sctp_transport *t;
 964
 965	t = sctp_assoc_choose_alter_transport(asoc, chunk->transport);
 966	asoc->timeouts[SCTP_EVENT_TIMEOUT_T4_RTO] = t->rto;
 967	chunk->transport = t;
 968}
 969
 970/* Process an incoming Operation Error Chunk. */
 971static void sctp_cmd_process_operr(struct sctp_cmd_seq *cmds,
 972				   struct sctp_association *asoc,
 973				   struct sctp_chunk *chunk)
 974{
 975	struct sctp_errhdr *err_hdr;
 976	struct sctp_ulpevent *ev;
 977
 978	while (chunk->chunk_end > chunk->skb->data) {
 979		err_hdr = (struct sctp_errhdr *)(chunk->skb->data);
 980
 981		ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
 982						     GFP_ATOMIC);
 983		if (!ev)
 984			return;
 985
 986		asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
 987
 988		switch (err_hdr->cause) {
 989		case SCTP_ERROR_UNKNOWN_CHUNK:
 990		{
 991			struct sctp_chunkhdr *unk_chunk_hdr;
 992
 993			unk_chunk_hdr = (struct sctp_chunkhdr *)(err_hdr + 1);
 994			switch (unk_chunk_hdr->type) {
 995			/* ADDIP 4.1 A9) If the peer responds to an ASCONF with
 996			 * an ERROR chunk reporting that it did not recognized
 997			 * the ASCONF chunk type, the sender of the ASCONF MUST
 998			 * NOT send any further ASCONF chunks and MUST stop its
 999			 * T-4 timer.
1000			 */
1001			case SCTP_CID_ASCONF:
1002				if (asoc->peer.asconf_capable == 0)
1003					break;
1004
1005				asoc->peer.asconf_capable = 0;
1006				sctp_add_cmd_sf(cmds, SCTP_CMD_TIMER_STOP,
1007					SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
1008				break;
1009			default:
1010				break;
1011			}
1012			break;
1013		}
1014		default:
1015			break;
1016		}
1017	}
1018}
1019
1020/* Helper function to remove the association non-primary peer
1021 * transports.
1022 */
1023static void sctp_cmd_del_non_primary(struct sctp_association *asoc)
1024{
1025	struct sctp_transport *t;
1026	struct list_head *temp;
1027	struct list_head *pos;
1028
1029	list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
1030		t = list_entry(pos, struct sctp_transport, transports);
1031		if (!sctp_cmp_addr_exact(&t->ipaddr,
1032					 &asoc->peer.primary_addr)) {
1033			sctp_assoc_rm_peer(asoc, t);
1034		}
1035	}
1036}
1037
1038/* Helper function to set sk_err on a 1-1 style socket. */
1039static void sctp_cmd_set_sk_err(struct sctp_association *asoc, int error)
1040{
1041	struct sock *sk = asoc->base.sk;
1042
1043	if (!sctp_style(sk, UDP))
1044		sk->sk_err = error;
1045}
1046
1047/* Helper function to generate an association change event */
1048static void sctp_cmd_assoc_change(struct sctp_cmd_seq *commands,
1049				  struct sctp_association *asoc,
1050				  u8 state)
1051{
1052	struct sctp_ulpevent *ev;
1053
1054	ev = sctp_ulpevent_make_assoc_change(asoc, 0, state, 0,
1055					    asoc->c.sinit_num_ostreams,
1056					    asoc->c.sinit_max_instreams,
1057					    NULL, GFP_ATOMIC);
1058	if (ev)
1059		asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
1060}
1061
1062static void sctp_cmd_peer_no_auth(struct sctp_cmd_seq *commands,
1063				  struct sctp_association *asoc)
1064{
1065	struct sctp_ulpevent *ev;
1066
1067	ev = sctp_ulpevent_make_authkey(asoc, 0, SCTP_AUTH_NO_AUTH, GFP_ATOMIC);
1068	if (ev)
1069		asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
1070}
1071
1072/* Helper function to generate an adaptation indication event */
1073static void sctp_cmd_adaptation_ind(struct sctp_cmd_seq *commands,
1074				    struct sctp_association *asoc)
1075{
1076	struct sctp_ulpevent *ev;
1077
1078	ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
1079
1080	if (ev)
1081		asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
1082}
1083
1084
1085static void sctp_cmd_t1_timer_update(struct sctp_association *asoc,
1086				     enum sctp_event_timeout timer,
1087				     char *name)
1088{
1089	struct sctp_transport *t;
1090
1091	t = asoc->init_last_sent_to;
1092	asoc->init_err_counter++;
1093
1094	if (t->init_sent_count > (asoc->init_cycle + 1)) {
1095		asoc->timeouts[timer] *= 2;
1096		if (asoc->timeouts[timer] > asoc->max_init_timeo) {
1097			asoc->timeouts[timer] = asoc->max_init_timeo;
1098		}
1099		asoc->init_cycle++;
1100
1101		pr_debug("%s: T1[%s] timeout adjustment init_err_counter:%d"
1102			 " cycle:%d timeout:%ld\n", __func__, name,
1103			 asoc->init_err_counter, asoc->init_cycle,
1104			 asoc->timeouts[timer]);
1105	}
1106
1107}
1108
1109/* Send the whole message, chunk by chunk, to the outqueue.
1110 * This way the whole message is queued up and bundling if
1111 * encouraged for small fragments.
1112 */
1113static void sctp_cmd_send_msg(struct sctp_association *asoc,
1114			      struct sctp_datamsg *msg, gfp_t gfp)
1115{
1116	struct sctp_chunk *chunk;
1117
1118	list_for_each_entry(chunk, &msg->chunks, frag_list)
1119		sctp_outq_tail(&asoc->outqueue, chunk, gfp);
1120
1121	asoc->outqueue.sched->enqueue(&asoc->outqueue, msg);
1122}
1123
1124
1125/* These three macros allow us to pull the debugging code out of the
1126 * main flow of sctp_do_sm() to keep attention focused on the real
1127 * functionality there.
1128 */
1129#define debug_pre_sfn() \
1130	pr_debug("%s[pre-fn]: ep:%p, %s, %s, asoc:%p[%s], %s\n", __func__, \
1131		 ep, sctp_evttype_tbl[event_type], (*debug_fn)(subtype),   \
1132		 asoc, sctp_state_tbl[state], state_fn->name)
1133
1134#define debug_post_sfn() \
1135	pr_debug("%s[post-fn]: asoc:%p, status:%s\n", __func__, asoc, \
1136		 sctp_status_tbl[status])
1137
1138#define debug_post_sfx() \
1139	pr_debug("%s[post-sfx]: error:%d, asoc:%p[%s]\n", __func__, error, \
1140		 asoc, sctp_state_tbl[(asoc && sctp_id2assoc(ep->base.sk, \
1141		 sctp_assoc2id(asoc))) ? asoc->state : SCTP_STATE_CLOSED])
1142
1143/*
1144 * This is the master state machine processing function.
1145 *
1146 * If you want to understand all of lksctp, this is a
1147 * good place to start.
1148 */
1149int sctp_do_sm(struct net *net, enum sctp_event_type event_type,
1150	       union sctp_subtype subtype, enum sctp_state state,
1151	       struct sctp_endpoint *ep, struct sctp_association *asoc,
1152	       void *event_arg, gfp_t gfp)
1153{
1154	typedef const char *(printfn_t)(union sctp_subtype);
1155	static printfn_t *table[] = {
1156		NULL, sctp_cname, sctp_tname, sctp_oname, sctp_pname,
1157	};
1158	printfn_t *debug_fn  __attribute__ ((unused)) = table[event_type];
1159	const struct sctp_sm_table_entry *state_fn;
1160	struct sctp_cmd_seq commands;
1161	enum sctp_disposition status;
1162	int error = 0;
1163
1164	/* Look up the state function, run it, and then process the
1165	 * side effects.  These three steps are the heart of lksctp.
1166	 */
1167	state_fn = sctp_sm_lookup_event(net, event_type, state, subtype);
1168
1169	sctp_init_cmd_seq(&commands);
1170
1171	debug_pre_sfn();
1172	status = state_fn->fn(net, ep, asoc, subtype, event_arg, &commands);
1173	debug_post_sfn();
1174
1175	error = sctp_side_effects(event_type, subtype, state,
1176				  ep, &asoc, event_arg, status,
1177				  &commands, gfp);
1178	debug_post_sfx();
1179
1180	return error;
1181}
1182
1183/*****************************************************************
1184 * This the master state function side effect processing function.
1185 *****************************************************************/
1186static int sctp_side_effects(enum sctp_event_type event_type,
1187			     union sctp_subtype subtype,
1188			     enum sctp_state state,
1189			     struct sctp_endpoint *ep,
1190			     struct sctp_association **asoc,
1191			     void *event_arg,
1192			     enum sctp_disposition status,
1193			     struct sctp_cmd_seq *commands,
1194			     gfp_t gfp)
1195{
1196	int error;
1197
1198	/* FIXME - Most of the dispositions left today would be categorized
1199	 * as "exceptional" dispositions.  For those dispositions, it
1200	 * may not be proper to run through any of the commands at all.
1201	 * For example, the command interpreter might be run only with
1202	 * disposition SCTP_DISPOSITION_CONSUME.
1203	 */
1204	if (0 != (error = sctp_cmd_interpreter(event_type, subtype, state,
1205					       ep, *asoc,
1206					       event_arg, status,
1207					       commands, gfp)))
1208		goto bail;
1209
1210	switch (status) {
1211	case SCTP_DISPOSITION_DISCARD:
1212		pr_debug("%s: ignored sctp protocol event - state:%d, "
1213			 "event_type:%d, event_id:%d\n", __func__, state,
1214			 event_type, subtype.chunk);
1215		break;
1216
1217	case SCTP_DISPOSITION_NOMEM:
1218		/* We ran out of memory, so we need to discard this
1219		 * packet.
1220		 */
1221		/* BUG--we should now recover some memory, probably by
1222		 * reneging...
1223		 */
1224		error = -ENOMEM;
1225		break;
1226
1227	case SCTP_DISPOSITION_DELETE_TCB:
1228	case SCTP_DISPOSITION_ABORT:
1229		/* This should now be a command. */
1230		*asoc = NULL;
1231		break;
1232
1233	case SCTP_DISPOSITION_CONSUME:
1234		/*
1235		 * We should no longer have much work to do here as the
1236		 * real work has been done as explicit commands above.
1237		 */
1238		break;
1239
1240	case SCTP_DISPOSITION_VIOLATION:
1241		net_err_ratelimited("protocol violation state %d chunkid %d\n",
1242				    state, subtype.chunk);
1243		break;
1244
1245	case SCTP_DISPOSITION_NOT_IMPL:
1246		pr_warn("unimplemented feature in state %d, event_type %d, event_id %d\n",
1247			state, event_type, subtype.chunk);
1248		break;
1249
1250	case SCTP_DISPOSITION_BUG:
1251		pr_err("bug in state %d, event_type %d, event_id %d\n",
1252		       state, event_type, subtype.chunk);
1253		BUG();
1254		break;
1255
1256	default:
1257		pr_err("impossible disposition %d in state %d, event_type %d, event_id %d\n",
1258		       status, state, event_type, subtype.chunk);
1259		error = status;
1260		if (error >= 0)
1261			error = -EINVAL;
1262		WARN_ON_ONCE(1);
1263		break;
1264	}
1265
1266bail:
1267	return error;
1268}
1269
1270/********************************************************************
1271 * 2nd Level Abstractions
1272 ********************************************************************/
1273
1274/* This is the side-effect interpreter.  */
1275static int sctp_cmd_interpreter(enum sctp_event_type event_type,
1276				union sctp_subtype subtype,
1277				enum sctp_state state,
1278				struct sctp_endpoint *ep,
1279				struct sctp_association *asoc,
1280				void *event_arg,
1281				enum sctp_disposition status,
1282				struct sctp_cmd_seq *commands,
1283				gfp_t gfp)
1284{
1285	struct sctp_sock *sp = sctp_sk(ep->base.sk);
1286	struct sctp_chunk *chunk = NULL, *new_obj;
1287	struct sctp_packet *packet;
1288	struct sctp_sackhdr sackh;
1289	struct timer_list *timer;
1290	struct sctp_transport *t;
1291	unsigned long timeout;
1292	struct sctp_cmd *cmd;
1293	int local_cork = 0;
1294	int error = 0;
1295	int force;
1296
1297	if (SCTP_EVENT_T_TIMEOUT != event_type)
1298		chunk = event_arg;
1299
1300	/* Note:  This whole file is a huge candidate for rework.
1301	 * For example, each command could either have its own handler, so
1302	 * the loop would look like:
1303	 *     while (cmds)
1304	 *         cmd->handle(x, y, z)
1305	 * --jgrimm
1306	 */
1307	while (NULL != (cmd = sctp_next_cmd(commands))) {
1308		switch (cmd->verb) {
1309		case SCTP_CMD_NOP:
1310			/* Do nothing. */
1311			break;
1312
1313		case SCTP_CMD_NEW_ASOC:
1314			/* Register a new association.  */
1315			if (local_cork) {
1316				sctp_outq_uncork(&asoc->outqueue, gfp);
1317				local_cork = 0;
1318			}
1319
1320			/* Register with the endpoint.  */
1321			asoc = cmd->obj.asoc;
1322			BUG_ON(asoc->peer.primary_path == NULL);
1323			sctp_endpoint_add_asoc(ep, asoc);
1324			break;
1325
1326		case SCTP_CMD_PURGE_OUTQUEUE:
1327		       sctp_outq_teardown(&asoc->outqueue);
1328		       break;
1329
1330		case SCTP_CMD_DELETE_TCB:
1331			if (local_cork) {
1332				sctp_outq_uncork(&asoc->outqueue, gfp);
1333				local_cork = 0;
1334			}
1335			/* Delete the current association.  */
1336			sctp_cmd_delete_tcb(commands, asoc);
1337			asoc = NULL;
1338			break;
1339
1340		case SCTP_CMD_NEW_STATE:
1341			/* Enter a new state.  */
1342			sctp_cmd_new_state(commands, asoc, cmd->obj.state);
1343			break;
1344
1345		case SCTP_CMD_REPORT_TSN:
1346			/* Record the arrival of a TSN.  */
1347			error = sctp_tsnmap_mark(&asoc->peer.tsn_map,
1348						 cmd->obj.u32, NULL);
1349			break;
1350
1351		case SCTP_CMD_REPORT_FWDTSN:
1352			asoc->stream.si->report_ftsn(&asoc->ulpq, cmd->obj.u32);
1353			break;
1354
1355		case SCTP_CMD_PROCESS_FWDTSN:
1356			asoc->stream.si->handle_ftsn(&asoc->ulpq,
1357						     cmd->obj.chunk);
1358			break;
1359
1360		case SCTP_CMD_GEN_SACK:
1361			/* Generate a Selective ACK.
1362			 * The argument tells us whether to just count
1363			 * the packet and MAYBE generate a SACK, or
1364			 * force a SACK out.
1365			 */
1366			force = cmd->obj.i32;
1367			error = sctp_gen_sack(asoc, force, commands);
1368			break;
1369
1370		case SCTP_CMD_PROCESS_SACK:
1371			/* Process an inbound SACK.  */
1372			error = sctp_cmd_process_sack(commands, asoc,
1373						      cmd->obj.chunk);
1374			break;
1375
1376		case SCTP_CMD_GEN_INIT_ACK:
1377			/* Generate an INIT ACK chunk.  */
1378			new_obj = sctp_make_init_ack(asoc, chunk, GFP_ATOMIC,
1379						     0);
1380			if (!new_obj) {
1381				error = -ENOMEM;
1382				break;
1383			}
1384
1385			sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1386					SCTP_CHUNK(new_obj));
1387			break;
1388
1389		case SCTP_CMD_PEER_INIT:
1390			/* Process a unified INIT from the peer.
1391			 * Note: Only used during INIT-ACK processing.  If
1392			 * there is an error just return to the outter
1393			 * layer which will bail.
1394			 */
1395			error = sctp_cmd_process_init(commands, asoc, chunk,
1396						      cmd->obj.init, gfp);
1397			break;
1398
1399		case SCTP_CMD_GEN_COOKIE_ECHO:
1400			/* Generate a COOKIE ECHO chunk.  */
1401			new_obj = sctp_make_cookie_echo(asoc, chunk);
1402			if (!new_obj) {
1403				if (cmd->obj.chunk)
1404					sctp_chunk_free(cmd->obj.chunk);
1405				error = -ENOMEM;
1406				break;
1407			}
1408			sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1409					SCTP_CHUNK(new_obj));
1410
1411			/* If there is an ERROR chunk to be sent along with
1412			 * the COOKIE_ECHO, send it, too.
1413			 */
1414			if (cmd->obj.chunk)
1415				sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1416						SCTP_CHUNK(cmd->obj.chunk));
1417
1418			if (new_obj->transport) {
1419				new_obj->transport->init_sent_count++;
1420				asoc->init_last_sent_to = new_obj->transport;
1421			}
1422
1423			/* FIXME - Eventually come up with a cleaner way to
1424			 * enabling COOKIE-ECHO + DATA bundling during
1425			 * multihoming stale cookie scenarios, the following
1426			 * command plays with asoc->peer.retran_path to
1427			 * avoid the problem of sending the COOKIE-ECHO and
1428			 * DATA in different paths, which could result
1429			 * in the association being ABORTed if the DATA chunk
1430			 * is processed first by the server.  Checking the
1431			 * init error counter simply causes this command
1432			 * to be executed only during failed attempts of
1433			 * association establishment.
1434			 */
1435			if ((asoc->peer.retran_path !=
1436			     asoc->peer.primary_path) &&
1437			    (asoc->init_err_counter > 0)) {
1438				sctp_add_cmd_sf(commands,
1439						SCTP_CMD_FORCE_PRIM_RETRAN,
1440						SCTP_NULL());
1441			}
1442
1443			break;
1444
1445		case SCTP_CMD_GEN_SHUTDOWN:
1446			/* Generate SHUTDOWN when in SHUTDOWN_SENT state.
1447			 * Reset error counts.
1448			 */
1449			asoc->overall_error_count = 0;
1450
1451			/* Generate a SHUTDOWN chunk.  */
1452			new_obj = sctp_make_shutdown(asoc, chunk);
1453			if (!new_obj) {
1454				error = -ENOMEM;
1455				break;
1456			}
1457			sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1458					SCTP_CHUNK(new_obj));
1459			break;
1460
1461		case SCTP_CMD_CHUNK_ULP:
1462			/* Send a chunk to the sockets layer.  */
1463			pr_debug("%s: sm_sideff: chunk_up:%p, ulpq:%p\n",
1464				 __func__, cmd->obj.chunk, &asoc->ulpq);
1465
1466			asoc->stream.si->ulpevent_data(&asoc->ulpq,
1467						       cmd->obj.chunk,
1468						       GFP_ATOMIC);
1469			break;
1470
1471		case SCTP_CMD_EVENT_ULP:
1472			/* Send a notification to the sockets layer.  */
1473			pr_debug("%s: sm_sideff: event_up:%p, ulpq:%p\n",
1474				 __func__, cmd->obj.ulpevent, &asoc->ulpq);
1475
1476			asoc->stream.si->enqueue_event(&asoc->ulpq,
1477						       cmd->obj.ulpevent);
1478			break;
1479
1480		case SCTP_CMD_REPLY:
1481			/* If an caller has not already corked, do cork. */
1482			if (!asoc->outqueue.cork) {
1483				sctp_outq_cork(&asoc->outqueue);
1484				local_cork = 1;
1485			}
1486			/* Send a chunk to our peer.  */
1487			sctp_outq_tail(&asoc->outqueue, cmd->obj.chunk, gfp);
1488			break;
1489
1490		case SCTP_CMD_SEND_PKT:
1491			/* Send a full packet to our peer.  */
1492			packet = cmd->obj.packet;
1493			sctp_packet_transmit(packet, gfp);
1494			sctp_ootb_pkt_free(packet);
1495			break;
1496
1497		case SCTP_CMD_T1_RETRAN:
1498			/* Mark a transport for retransmission.  */
1499			sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1500					SCTP_RTXR_T1_RTX);
1501			break;
1502
1503		case SCTP_CMD_RETRAN:
1504			/* Mark a transport for retransmission.  */
1505			sctp_retransmit(&asoc->outqueue, cmd->obj.transport,
1506					SCTP_RTXR_T3_RTX);
1507			break;
1508
1509		case SCTP_CMD_ECN_CE:
1510			/* Do delayed CE processing.   */
1511			sctp_do_ecn_ce_work(asoc, cmd->obj.u32);
1512			break;
1513
1514		case SCTP_CMD_ECN_ECNE:
1515			/* Do delayed ECNE processing. */
1516			new_obj = sctp_do_ecn_ecne_work(asoc, cmd->obj.u32,
1517							chunk);
1518			if (new_obj)
1519				sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1520						SCTP_CHUNK(new_obj));
1521			break;
1522
1523		case SCTP_CMD_ECN_CWR:
1524			/* Do delayed CWR processing.  */
1525			sctp_do_ecn_cwr_work(asoc, cmd->obj.u32);
1526			break;
1527
1528		case SCTP_CMD_SETUP_T2:
1529			sctp_cmd_setup_t2(commands, asoc, cmd->obj.chunk);
1530			break;
1531
1532		case SCTP_CMD_TIMER_START_ONCE:
1533			timer = &asoc->timers[cmd->obj.to];
1534
1535			if (timer_pending(timer))
1536				break;
1537			fallthrough;
1538
1539		case SCTP_CMD_TIMER_START:
1540			timer = &asoc->timers[cmd->obj.to];
1541			timeout = asoc->timeouts[cmd->obj.to];
1542			BUG_ON(!timeout);
1543
1544			/*
1545			 * SCTP has a hard time with timer starts.  Because we process
1546			 * timer starts as side effects, it can be hard to tell if we
1547			 * have already started a timer or not, which leads to BUG
1548			 * halts when we call add_timer. So here, instead of just starting
1549			 * a timer, if the timer is already started, and just mod
1550			 * the timer with the shorter of the two expiration times
1551			 */
1552			if (!timer_pending(timer))
1553				sctp_association_hold(asoc);
1554			timer_reduce(timer, jiffies + timeout);
1555			break;
1556
1557		case SCTP_CMD_TIMER_RESTART:
1558			timer = &asoc->timers[cmd->obj.to];
1559			timeout = asoc->timeouts[cmd->obj.to];
1560			if (!mod_timer(timer, jiffies + timeout))
1561				sctp_association_hold(asoc);
1562			break;
1563
1564		case SCTP_CMD_TIMER_STOP:
1565			timer = &asoc->timers[cmd->obj.to];
1566			if (timer_delete(timer))
1567				sctp_association_put(asoc);
1568			break;
1569
1570		case SCTP_CMD_INIT_CHOOSE_TRANSPORT:
1571			chunk = cmd->obj.chunk;
1572			t = sctp_assoc_choose_alter_transport(asoc,
1573						asoc->init_last_sent_to);
1574			asoc->init_last_sent_to = t;
1575			chunk->transport = t;
1576			t->init_sent_count++;
1577			/* Set the new transport as primary */
1578			sctp_assoc_set_primary(asoc, t);
1579			break;
1580
1581		case SCTP_CMD_INIT_RESTART:
1582			/* Do the needed accounting and updates
1583			 * associated with restarting an initialization
1584			 * timer. Only multiply the timeout by two if
1585			 * all transports have been tried at the current
1586			 * timeout.
1587			 */
1588			sctp_cmd_t1_timer_update(asoc,
1589						SCTP_EVENT_TIMEOUT_T1_INIT,
1590						"INIT");
1591
1592			sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
1593					SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1594			break;
1595
1596		case SCTP_CMD_COOKIEECHO_RESTART:
1597			/* Do the needed accounting and updates
1598			 * associated with restarting an initialization
1599			 * timer. Only multiply the timeout by two if
1600			 * all transports have been tried at the current
1601			 * timeout.
1602			 */
1603			sctp_cmd_t1_timer_update(asoc,
1604						SCTP_EVENT_TIMEOUT_T1_COOKIE,
1605						"COOKIE");
1606
1607			/* If we've sent any data bundled with
1608			 * COOKIE-ECHO we need to resend.
1609			 */
1610			list_for_each_entry(t, &asoc->peer.transport_addr_list,
1611					transports) {
1612				sctp_retransmit_mark(&asoc->outqueue, t,
1613					    SCTP_RTXR_T1_RTX);
1614			}
1615
1616			sctp_add_cmd_sf(commands,
1617					SCTP_CMD_TIMER_RESTART,
1618					SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1619			break;
1620
1621		case SCTP_CMD_INIT_FAILED:
1622			sctp_cmd_init_failed(commands, asoc, cmd->obj.u16);
1623			break;
1624
1625		case SCTP_CMD_ASSOC_FAILED:
1626			sctp_cmd_assoc_failed(commands, asoc, event_type,
1627					      subtype, chunk, cmd->obj.u16);
1628			break;
1629
1630		case SCTP_CMD_INIT_COUNTER_INC:
1631			asoc->init_err_counter++;
1632			break;
1633
1634		case SCTP_CMD_INIT_COUNTER_RESET:
1635			asoc->init_err_counter = 0;
1636			asoc->init_cycle = 0;
1637			list_for_each_entry(t, &asoc->peer.transport_addr_list,
1638					    transports) {
1639				t->init_sent_count = 0;
1640			}
1641			break;
1642
1643		case SCTP_CMD_REPORT_DUP:
1644			sctp_tsnmap_mark_dup(&asoc->peer.tsn_map,
1645					     cmd->obj.u32);
1646			break;
1647
1648		case SCTP_CMD_REPORT_BAD_TAG:
1649			pr_debug("%s: vtag mismatch!\n", __func__);
1650			break;
1651
1652		case SCTP_CMD_STRIKE:
1653			/* Mark one strike against a transport.  */
1654			sctp_do_8_2_transport_strike(commands, asoc,
1655						    cmd->obj.transport, 0);
1656			break;
1657
1658		case SCTP_CMD_TRANSPORT_IDLE:
1659			t = cmd->obj.transport;
1660			sctp_transport_lower_cwnd(t, SCTP_LOWER_CWND_INACTIVE);
1661			break;
1662
1663		case SCTP_CMD_TRANSPORT_HB_SENT:
1664			t = cmd->obj.transport;
1665			sctp_do_8_2_transport_strike(commands, asoc,
1666						     t, 1);
1667			t->hb_sent = 1;
1668			break;
1669
1670		case SCTP_CMD_TRANSPORT_ON:
1671			t = cmd->obj.transport;
1672			sctp_cmd_transport_on(commands, asoc, t, chunk);
1673			break;
1674
1675		case SCTP_CMD_HB_TIMERS_START:
1676			sctp_cmd_hb_timers_start(commands, asoc);
1677			break;
1678
1679		case SCTP_CMD_HB_TIMER_UPDATE:
1680			t = cmd->obj.transport;
1681			sctp_transport_reset_hb_timer(t);
1682			break;
1683
1684		case SCTP_CMD_HB_TIMERS_STOP:
1685			sctp_cmd_hb_timers_stop(commands, asoc);
1686			break;
1687
1688		case SCTP_CMD_PROBE_TIMER_UPDATE:
1689			t = cmd->obj.transport;
1690			sctp_transport_reset_probe_timer(t);
1691			break;
1692
1693		case SCTP_CMD_REPORT_ERROR:
1694			error = cmd->obj.error;
1695			break;
1696
1697		case SCTP_CMD_PROCESS_CTSN:
1698			/* Dummy up a SACK for processing. */
1699			sackh.cum_tsn_ack = cmd->obj.be32;
1700			sackh.a_rwnd = htonl(asoc->peer.rwnd +
1701					     asoc->outqueue.outstanding_bytes);
1702			sackh.num_gap_ack_blocks = 0;
1703			sackh.num_dup_tsns = 0;
1704			chunk->subh.sack_hdr = &sackh;
1705			sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK,
1706					SCTP_CHUNK(chunk));
1707			break;
1708
1709		case SCTP_CMD_DISCARD_PACKET:
1710			/* We need to discard the whole packet.
1711			 * Uncork the queue since there might be
1712			 * responses pending
1713			 */
1714			chunk->pdiscard = 1;
1715			if (asoc) {
1716				sctp_outq_uncork(&asoc->outqueue, gfp);
1717				local_cork = 0;
1718			}
1719			break;
1720
1721		case SCTP_CMD_RTO_PENDING:
1722			t = cmd->obj.transport;
1723			t->rto_pending = 1;
1724			break;
1725
1726		case SCTP_CMD_PART_DELIVER:
1727			asoc->stream.si->start_pd(&asoc->ulpq, GFP_ATOMIC);
1728			break;
1729
1730		case SCTP_CMD_RENEGE:
1731			asoc->stream.si->renege_events(&asoc->ulpq,
1732						       cmd->obj.chunk,
1733						       GFP_ATOMIC);
1734			break;
1735
1736		case SCTP_CMD_SETUP_T4:
1737			sctp_cmd_setup_t4(commands, asoc, cmd->obj.chunk);
1738			break;
1739
1740		case SCTP_CMD_PROCESS_OPERR:
1741			sctp_cmd_process_operr(commands, asoc, chunk);
1742			break;
1743		case SCTP_CMD_CLEAR_INIT_TAG:
1744			asoc->peer.i.init_tag = 0;
1745			break;
1746		case SCTP_CMD_DEL_NON_PRIMARY:
1747			sctp_cmd_del_non_primary(asoc);
1748			break;
1749		case SCTP_CMD_T3_RTX_TIMERS_STOP:
1750			sctp_cmd_t3_rtx_timers_stop(commands, asoc);
1751			break;
1752		case SCTP_CMD_FORCE_PRIM_RETRAN:
1753			t = asoc->peer.retran_path;
1754			asoc->peer.retran_path = asoc->peer.primary_path;
1755			sctp_outq_uncork(&asoc->outqueue, gfp);
1756			local_cork = 0;
1757			asoc->peer.retran_path = t;
1758			break;
1759		case SCTP_CMD_SET_SK_ERR:
1760			sctp_cmd_set_sk_err(asoc, cmd->obj.error);
1761			break;
1762		case SCTP_CMD_ASSOC_CHANGE:
1763			sctp_cmd_assoc_change(commands, asoc,
1764					      cmd->obj.u8);
1765			break;
1766		case SCTP_CMD_ADAPTATION_IND:
1767			sctp_cmd_adaptation_ind(commands, asoc);
1768			break;
1769		case SCTP_CMD_PEER_NO_AUTH:
1770			sctp_cmd_peer_no_auth(commands, asoc);
1771			break;
1772
1773		case SCTP_CMD_ASSOC_SHKEY:
1774			error = sctp_auth_asoc_init_active_key(asoc,
1775						GFP_ATOMIC);
1776			break;
1777		case SCTP_CMD_UPDATE_INITTAG:
1778			asoc->peer.i.init_tag = cmd->obj.u32;
1779			break;
1780		case SCTP_CMD_SEND_MSG:
1781			if (!asoc->outqueue.cork) {
1782				sctp_outq_cork(&asoc->outqueue);
1783				local_cork = 1;
1784			}
1785			sctp_cmd_send_msg(asoc, cmd->obj.msg, gfp);
1786			break;
1787		case SCTP_CMD_PURGE_ASCONF_QUEUE:
1788			sctp_asconf_queue_teardown(asoc);
1789			break;
1790
1791		case SCTP_CMD_SET_ASOC:
1792			if (asoc && local_cork) {
1793				sctp_outq_uncork(&asoc->outqueue, gfp);
1794				local_cork = 0;
1795			}
1796			asoc = cmd->obj.asoc;
1797			break;
1798
1799		default:
1800			pr_warn("Impossible command: %u\n",
1801				cmd->verb);
1802			break;
1803		}
1804
1805		if (error) {
1806			cmd = sctp_next_cmd(commands);
1807			while (cmd) {
1808				if (cmd->verb == SCTP_CMD_REPLY)
1809					sctp_chunk_free(cmd->obj.chunk);
1810				cmd = sctp_next_cmd(commands);
1811			}
1812			break;
1813		}
1814	}
1815
1816	/* If this is in response to a received chunk, wait until
1817	 * we are done with the packet to open the queue so that we don't
1818	 * send multiple packets in response to a single request.
1819	 */
1820	if (asoc && SCTP_EVENT_T_CHUNK == event_type && chunk) {
1821		if (chunk->end_of_packet || chunk->singleton)
1822			sctp_outq_uncork(&asoc->outqueue, gfp);
1823	} else if (local_cork)
1824		sctp_outq_uncork(&asoc->outqueue, gfp);
1825
1826	if (sp->data_ready_signalled)
1827		sp->data_ready_signalled = 0;
1828
1829	return error;
1830}