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