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