associola.c 48.7 KB
Newer Older
1
/* SCTP kernel implementation
L
Linus Torvalds 已提交
2 3 4 5 6 7
 * (C) Copyright IBM Corp. 2001, 2004
 * Copyright (c) 1999-2000 Cisco, Inc.
 * Copyright (c) 1999-2001 Motorola, Inc.
 * Copyright (c) 2001 Intel Corp.
 * Copyright (c) 2001 La Monte H.P. Yarroll
 *
8
 * This file is part of the SCTP kernel implementation
L
Linus Torvalds 已提交
9 10 11
 *
 * This module provides the abstraction for an SCTP association.
 *
12
 * This SCTP implementation is free software;
L
Linus Torvalds 已提交
13 14 15 16 17
 * you can redistribute it and/or modify it under the terms of
 * the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
18
 * This SCTP implementation is distributed in the hope that it
L
Linus Torvalds 已提交
19 20 21 22 23 24
 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
 *                 ************************
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
25 26
 * along with GNU CC; see the file COPYING.  If not, see
 * <http://www.gnu.org/licenses/>.
L
Linus Torvalds 已提交
27 28 29
 *
 * Please send any bug reports or fixes you make to the
 * email address(es):
30
 *    lksctp developers <linux-sctp@vger.kernel.org>
L
Linus Torvalds 已提交
31 32 33 34 35 36 37 38 39 40 41 42 43
 *
 * Written or modified by:
 *    La Monte H.P. Yarroll <piggy@acm.org>
 *    Karl Knutson          <karl@athena.chicago.il.us>
 *    Jon Grimm             <jgrimm@us.ibm.com>
 *    Xingang Guo           <xingang.guo@intel.com>
 *    Hui Huang             <hui.huang@nokia.com>
 *    Sridhar Samudrala	    <sri@us.ibm.com>
 *    Daisy Chang	    <daisyc@us.ibm.com>
 *    Ryan Layer	    <rmlayer@us.ibm.com>
 *    Kevin Gao             <kevin.gao@intel.com>
 */

44 45
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

L
Linus Torvalds 已提交
46 47 48 49 50 51 52 53 54 55 56 57
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/poll.h>
#include <linux/init.h>

#include <linux/slab.h>
#include <linux/in.h>
#include <net/ipv6.h>
#include <net/sctp/sctp.h>
#include <net/sctp/sm.h>

/* Forward declarations for internal functions. */
58
static void sctp_select_active_and_retran_path(struct sctp_association *asoc);
D
David Howells 已提交
59
static void sctp_assoc_bh_rcv(struct work_struct *work);
60
static void sctp_assoc_free_asconf_acks(struct sctp_association *asoc);
61
static void sctp_assoc_free_asconf_queue(struct sctp_association *asoc);
L
Linus Torvalds 已提交
62 63 64 65 66 67 68 69

/* 1st Level Abstractions. */

/* Initialize a new association from provided memory. */
static struct sctp_association *sctp_association_init(struct sctp_association *asoc,
					  const struct sctp_endpoint *ep,
					  const struct sock *sk,
					  sctp_scope_t scope,
A
Al Viro 已提交
70
					  gfp_t gfp)
L
Linus Torvalds 已提交
71
{
72
	struct net *net = sock_net(sk);
L
Linus Torvalds 已提交
73
	struct sctp_sock *sp;
74
	sctp_paramhdr_t *p;
75
	int i;
L
Linus Torvalds 已提交
76 77 78 79 80 81 82

	/* Retrieve the SCTP per socket area.  */
	sp = sctp_sk((struct sock *)sk);

	/* Discarding const is appropriate here.  */
	asoc->ep = (struct sctp_endpoint *)ep;
	asoc->base.sk = (struct sock *)sk;
83 84

	sctp_endpoint_hold(asoc->ep);
L
Linus Torvalds 已提交
85 86 87 88 89 90 91 92 93 94 95 96
	sock_hold(asoc->base.sk);

	/* Initialize the common base substructure.  */
	asoc->base.type = SCTP_EP_TYPE_ASSOCIATION;

	/* Initialize the object handling fields.  */
	atomic_set(&asoc->base.refcnt, 1);

	/* Initialize the bind addr area.  */
	sctp_bind_addr_init(&asoc->base.bind_addr, ep->base.bind_addr.port);

	asoc->state = SCTP_STATE_CLOSED;
97
	asoc->cookie_life = ms_to_ktime(sp->assocparams.sasoc_cookie_life);
98
	asoc->user_frag = sp->user_frag;
L
Linus Torvalds 已提交
99 100 101 102 103

	/* Set the association max_retrans and RTO values from the
	 * socket values.
	 */
	asoc->max_retrans = sp->assocparams.sasoc_asocmaxrxt;
104
	asoc->pf_retrans  = net->sctp.pf_retrans;
105

L
Linus Torvalds 已提交
106 107 108 109
	asoc->rto_initial = msecs_to_jiffies(sp->rtoinfo.srto_initial);
	asoc->rto_max = msecs_to_jiffies(sp->rtoinfo.srto_max);
	asoc->rto_min = msecs_to_jiffies(sp->rtoinfo.srto_min);

110 111 112 113 114 115 116 117 118 119 120 121 122
	/* Initialize the association's heartbeat interval based on the
	 * sock configured value.
	 */
	asoc->hbinterval = msecs_to_jiffies(sp->hbinterval);

	/* Initialize path max retrans value. */
	asoc->pathmaxrxt = sp->pathmaxrxt;

	/* Initialize default path MTU. */
	asoc->pathmtu = sp->pathmtu;

	/* Set association default SACK delay */
	asoc->sackdelay = msecs_to_jiffies(sp->sackdelay);
123
	asoc->sackfreq = sp->sackfreq;
124 125 126 127 128 129

	/* Set the association default flags controlling
	 * Heartbeat, SACK delay, and Path MTU Discovery.
	 */
	asoc->param_flags = sp->param_flags;

130
	/* Initialize the maximum number of new data packets that can be sent
L
Linus Torvalds 已提交
131 132
	 * in a burst.
	 */
133
	asoc->max_burst = sp->max_burst;
L
Linus Torvalds 已提交
134

135 136 137 138 139 140 141 142 143
	/* initialize association timers */
	asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] = asoc->rto_initial;
	asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] = asoc->rto_initial;
	asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = asoc->rto_initial;

	/* sctpimpguide Section 2.12.2
	 * If the 'T5-shutdown-guard' timer is used, it SHOULD be set to the
	 * recommended value of 5 times 'RTO.Max'.
	 */
144
	asoc->timeouts[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD]
145 146
		= 5 * asoc->rto_max;

147
	asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] = asoc->sackdelay;
148
	asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE] = sp->autoclose * HZ;
149

150
	/* Initializes the timers */
151 152 153
	for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i)
		setup_timer(&asoc->timers[i], sctp_timer_events[i],
				(unsigned long)asoc);
L
Linus Torvalds 已提交
154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170

	/* Pull default initialization values from the sock options.
	 * Note: This assumes that the values have already been
	 * validated in the sock.
	 */
	asoc->c.sinit_max_instreams = sp->initmsg.sinit_max_instreams;
	asoc->c.sinit_num_ostreams  = sp->initmsg.sinit_num_ostreams;
	asoc->max_init_attempts	= sp->initmsg.sinit_max_attempts;

	asoc->max_init_timeo =
		 msecs_to_jiffies(sp->initmsg.sinit_max_init_timeo);

	/* Set the local window size for receive.
	 * This is also the rcvbuf space per association.
	 * RFC 6 - A SCTP receiver MUST be able to receive a minimum of
	 * 1500 bytes in one SCTP packet.
	 */
171
	if ((sk->sk_rcvbuf/2) < SCTP_DEFAULT_MINWINDOW)
L
Linus Torvalds 已提交
172 173
		asoc->rwnd = SCTP_DEFAULT_MINWINDOW;
	else
174
		asoc->rwnd = sk->sk_rcvbuf/2;
L
Linus Torvalds 已提交
175 176 177 178 179 180

	asoc->a_rwnd = asoc->rwnd;

	/* Use my own max window until I learn something better.  */
	asoc->peer.rwnd = SCTP_DEFAULT_MAXWINDOW;

181 182 183
	/* Initialize the receive memory counter */
	atomic_set(&asoc->rmem_alloc, 0);

L
Linus Torvalds 已提交
184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208
	init_waitqueue_head(&asoc->wait);

	asoc->c.my_vtag = sctp_generate_tag(ep);
	asoc->c.my_port = ep->base.bind_addr.port;

	asoc->c.initial_tsn = sctp_generate_tsn(ep);

	asoc->next_tsn = asoc->c.initial_tsn;

	asoc->ctsn_ack_point = asoc->next_tsn - 1;
	asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
	asoc->highest_sacked = asoc->ctsn_ack_point;
	asoc->last_cwr_tsn = asoc->ctsn_ack_point;

	/* ADDIP Section 4.1 Asconf Chunk Procedures
	 *
	 * When an endpoint has an ASCONF signaled change to be sent to the
	 * remote endpoint it should do the following:
	 * ...
	 * A2) a serial number should be assigned to the chunk. The serial
	 * number SHOULD be a monotonically increasing number. The serial
	 * numbers SHOULD be initialized at the start of the
	 * association to the same value as the initial TSN.
	 */
	asoc->addip_serial = asoc->c.initial_tsn;
209
	asoc->strreset_outseq = asoc->c.initial_tsn;
L
Linus Torvalds 已提交
210

211
	INIT_LIST_HEAD(&asoc->addip_chunk_list);
212
	INIT_LIST_HEAD(&asoc->asconf_ack_list);
L
Linus Torvalds 已提交
213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228

	/* Make an empty list of remote transport addresses.  */
	INIT_LIST_HEAD(&asoc->peer.transport_addr_list);

	/* RFC 2960 5.1 Normal Establishment of an Association
	 *
	 * After the reception of the first data chunk in an
	 * association the endpoint must immediately respond with a
	 * sack to acknowledge the data chunk.  Subsequent
	 * acknowledgements should be done as described in Section
	 * 6.2.
	 *
	 * [We implement this by telling a new association that it
	 * already received one packet.]
	 */
	asoc->peer.sack_needed = 1;
229
	asoc->peer.sack_generation = 1;
L
Linus Torvalds 已提交
230

231 232
	/* Assume that the peer will tell us if he recognizes ASCONF
	 * as part of INIT exchange.
233
	 * The sctp_addip_noauth option is there for backward compatibility
234
	 * and will revert old behavior.
L
Linus Torvalds 已提交
235
	 */
236
	if (net->sctp.addip_noauth)
237
		asoc->peer.asconf_capable = 1;
L
Linus Torvalds 已提交
238 239 240

	/* Create an input queue.  */
	sctp_inq_init(&asoc->base.inqueue);
D
David Howells 已提交
241
	sctp_inq_set_th_handler(&asoc->base.inqueue, sctp_assoc_bh_rcv);
L
Linus Torvalds 已提交
242 243 244 245 246 247 248

	/* Create an output queue.  */
	sctp_outq_init(asoc, &asoc->outqueue);

	if (!sctp_ulpq_init(&asoc->ulpq, asoc))
		goto fail_init;

249 250 251
	if (sctp_stream_new(asoc, gfp))
		goto fail_init;

L
Linus Torvalds 已提交
252 253 254 255
	/* Assume that peer would support both address types unless we are
	 * told otherwise.
	 */
	asoc->peer.ipv4_address = 1;
256 257
	if (asoc->base.sk->sk_family == PF_INET6)
		asoc->peer.ipv6_address = 1;
L
Linus Torvalds 已提交
258 259 260 261 262 263 264
	INIT_LIST_HEAD(&asoc->asocs);

	asoc->default_stream = sp->default_stream;
	asoc->default_ppid = sp->default_ppid;
	asoc->default_flags = sp->default_flags;
	asoc->default_context = sp->default_context;
	asoc->default_timetolive = sp->default_timetolive;
265
	asoc->default_rcv_context = sp->default_rcv_context;
L
Linus Torvalds 已提交
266

267 268
	/* AUTH related initializations */
	INIT_LIST_HEAD(&asoc->endpoint_shared_keys);
269
	if (sctp_auth_asoc_copy_shkeys(ep, asoc, gfp))
270
		goto stream_free;
271 272

	asoc->active_key_id = ep->active_key_id;
273
	asoc->prsctp_enable = ep->prsctp_enable;
274
	asoc->reconf_enable = ep->reconf_enable;
275
	asoc->strreset_enable = ep->strreset_enable;
276 277 278 279 280 281 282 283 284 285 286 287 288 289 290

	/* Save the hmacs and chunks list into this association */
	if (ep->auth_hmacs_list)
		memcpy(asoc->c.auth_hmacs, ep->auth_hmacs_list,
			ntohs(ep->auth_hmacs_list->param_hdr.length));
	if (ep->auth_chunk_list)
		memcpy(asoc->c.auth_chunks, ep->auth_chunk_list,
			ntohs(ep->auth_chunk_list->param_hdr.length));

	/* Get the AUTH random number for this association */
	p = (sctp_paramhdr_t *)asoc->c.auth_random;
	p->type = SCTP_PARAM_RANDOM;
	p->length = htons(sizeof(sctp_paramhdr_t) + SCTP_AUTH_RANDOM_LENGTH);
	get_random_bytes(p+1, SCTP_AUTH_RANDOM_LENGTH);

L
Linus Torvalds 已提交
291 292
	return asoc;

293 294
stream_free:
	sctp_stream_free(asoc->stream);
L
Linus Torvalds 已提交
295 296
fail_init:
	sock_put(asoc->base.sk);
297
	sctp_endpoint_put(asoc->ep);
L
Linus Torvalds 已提交
298 299 300 301 302 303
	return NULL;
}

/* Allocate and initialize a new association */
struct sctp_association *sctp_association_new(const struct sctp_endpoint *ep,
					 const struct sock *sk,
A
Alexey Dobriyan 已提交
304
					 sctp_scope_t scope,
A
Al Viro 已提交
305
					 gfp_t gfp)
L
Linus Torvalds 已提交
306 307 308
{
	struct sctp_association *asoc;

309
	asoc = kzalloc(sizeof(*asoc), gfp);
L
Linus Torvalds 已提交
310 311 312 313 314 315 316
	if (!asoc)
		goto fail;

	if (!sctp_association_init(asoc, ep, sk, scope, gfp))
		goto fail_init;

	SCTP_DBG_OBJCNT_INC(assoc);
317 318

	pr_debug("Created asoc %p\n", asoc);
L
Linus Torvalds 已提交
319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337

	return asoc;

fail_init:
	kfree(asoc);
fail:
	return NULL;
}

/* Free this association if possible.  There may still be users, so
 * the actual deallocation may be delayed.
 */
void sctp_association_free(struct sctp_association *asoc)
{
	struct sock *sk = asoc->base.sk;
	struct sctp_transport *transport;
	struct list_head *pos, *temp;
	int i;

338 339 340
	/* Only real associations count against the endpoint, so
	 * don't bother for if this is a temporary association.
	 */
341
	if (!list_empty(&asoc->asocs)) {
342 343 344 345 346 347 348 349
		list_del(&asoc->asocs);

		/* Decrement the backlog value for a TCP-style listening
		 * socket.
		 */
		if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
			sk->sk_ack_backlog--;
	}
L
Linus Torvalds 已提交
350 351 352 353

	/* Mark as dead, so other users can know this structure is
	 * going away.
	 */
354
	asoc->base.dead = true;
L
Linus Torvalds 已提交
355 356 357 358 359 360 361 362 363 364

	/* Dispose of any data lying around in the outqueue. */
	sctp_outq_free(&asoc->outqueue);

	/* Dispose of any pending messages for the upper layer. */
	sctp_ulpq_free(&asoc->ulpq);

	/* Dispose of any pending chunks on the inqueue. */
	sctp_inq_free(&asoc->base.inqueue);

365 366
	sctp_tsnmap_free(&asoc->peer.tsn_map);

367 368
	/* Free stream information. */
	sctp_stream_free(asoc->stream);
L
Linus Torvalds 已提交
369

X
Xin Long 已提交
370 371 372
	if (asoc->strreset_chunk)
		sctp_chunk_free(asoc->strreset_chunk);

L
Linus Torvalds 已提交
373 374 375 376 377 378 379 380 381
	/* Clean up the bound address list. */
	sctp_bind_addr_free(&asoc->base.bind_addr);

	/* Do we need to go through all of our timers and
	 * delete them?   To be safe we will try to delete all, but we
	 * should be able to go through and make a guess based
	 * on our state.
	 */
	for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i) {
382
		if (del_timer(&asoc->timers[i]))
L
Linus Torvalds 已提交
383 384 385 386
			sctp_association_put(asoc);
	}

	/* Free peer's cached cookie. */
J
Jesper Juhl 已提交
387
	kfree(asoc->peer.cookie);
388 389 390
	kfree(asoc->peer.peer_random);
	kfree(asoc->peer.peer_chunks);
	kfree(asoc->peer.peer_hmacs);
L
Linus Torvalds 已提交
391 392 393 394

	/* Release the transport structures. */
	list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
		transport = list_entry(pos, struct sctp_transport, transports);
395
		list_del_rcu(pos);
396
		sctp_unhash_transport(transport);
L
Linus Torvalds 已提交
397 398 399
		sctp_transport_free(transport);
	}

F
Frank Filz 已提交
400 401
	asoc->peer.transport_count = 0;

402
	sctp_asconf_queue_teardown(asoc);
L
Linus Torvalds 已提交
403

404
	/* Free pending address space being deleted */
405
	kfree(asoc->asconf_addr_del_pending);
406

407 408 409 410 411 412
	/* AUTH - Free the endpoint shared keys */
	sctp_auth_destroy_keys(&asoc->endpoint_shared_keys);

	/* AUTH - Free the association shared key */
	sctp_auth_key_put(asoc->asoc_shared_key);

L
Linus Torvalds 已提交
413 414 415 416 417 418
	sctp_association_put(asoc);
}

/* Cleanup and free up an association. */
static void sctp_association_destroy(struct sctp_association *asoc)
{
419 420 421 422
	if (unlikely(!asoc->base.dead)) {
		WARN(1, "Attempt to destroy undead association %p!\n", asoc);
		return;
	}
L
Linus Torvalds 已提交
423 424 425 426 427 428 429 430 431 432

	sctp_endpoint_put(asoc->ep);
	sock_put(asoc->base.sk);

	if (asoc->assoc_id != 0) {
		spin_lock_bh(&sctp_assocs_id_lock);
		idr_remove(&sctp_assocs_id, asoc->assoc_id);
		spin_unlock_bh(&sctp_assocs_id_lock);
	}

433
	WARN_ON(atomic_read(&asoc->rmem_alloc));
434

435 436
	kfree(asoc);
	SCTP_DBG_OBJCNT_DEC(assoc);
L
Linus Torvalds 已提交
437 438 439 440 441 442
}

/* Change the primary destination address for the peer. */
void sctp_assoc_set_primary(struct sctp_association *asoc,
			    struct sctp_transport *transport)
{
443 444 445 446 447 448 449 450 451
	int changeover = 0;

	/* it's a changeover only if we already have a primary path
	 * that we are changing
	 */
	if (asoc->peer.primary_path != NULL &&
	    asoc->peer.primary_path != transport)
		changeover = 1 ;

L
Linus Torvalds 已提交
452 453 454 455 456 457 458 459 460
	asoc->peer.primary_path = transport;

	/* Set a default msg_name for events. */
	memcpy(&asoc->peer.primary_addr, &transport->ipaddr,
	       sizeof(union sctp_addr));

	/* If the primary path is changing, assume that the
	 * user wants to use this new path.
	 */
461 462
	if ((transport->state == SCTP_ACTIVE) ||
	    (transport->state == SCTP_UNKNOWN))
L
Linus Torvalds 已提交
463 464 465 466 467 468 469 470 471 472 473 474
		asoc->peer.active_path = transport;

	/*
	 * SFR-CACC algorithm:
	 * Upon the receipt of a request to change the primary
	 * destination address, on the data structure for the new
	 * primary destination, the sender MUST do the following:
	 *
	 * 1) If CHANGEOVER_ACTIVE is set, then there was a switch
	 * to this destination address earlier. The sender MUST set
	 * CYCLING_CHANGEOVER to indicate that this switch is a
	 * double switch to the same destination address.
475 476 477
	 *
	 * Really, only bother is we have data queued or outstanding on
	 * the association.
L
Linus Torvalds 已提交
478
	 */
479 480 481
	if (!asoc->outqueue.outstanding_bytes && !asoc->outqueue.out_qlen)
		return;

L
Linus Torvalds 已提交
482
	if (transport->cacc.changeover_active)
483
		transport->cacc.cycling_changeover = changeover;
L
Linus Torvalds 已提交
484 485 486 487

	/* 2) The sender MUST set CHANGEOVER_ACTIVE to indicate that
	 * a changeover has occurred.
	 */
488
	transport->cacc.changeover_active = changeover;
L
Linus Torvalds 已提交
489 490 491 492 493 494 495

	/* 3) The sender MUST store the next TSN to be sent in
	 * next_tsn_at_change.
	 */
	transport->cacc.next_tsn_at_change = asoc->next_tsn;
}

F
Frank Filz 已提交
496 497 498 499 500 501 502
/* Remove a transport from an association.  */
void sctp_assoc_rm_peer(struct sctp_association *asoc,
			struct sctp_transport *peer)
{
	struct list_head	*pos;
	struct sctp_transport	*transport;

503 504
	pr_debug("%s: association:%p addr:%pISpc\n",
		 __func__, asoc, &peer->ipaddr.sa);
F
Frank Filz 已提交
505 506 507 508 509 510 511 512

	/* If we are to remove the current retran_path, update it
	 * to the next peer before removing this peer from the list.
	 */
	if (asoc->peer.retran_path == peer)
		sctp_assoc_update_retran_path(asoc);

	/* Remove this peer from the list. */
513
	list_del_rcu(&peer->transports);
514 515
	/* Remove this peer from the transport hashtable */
	sctp_unhash_transport(peer);
F
Frank Filz 已提交
516 517 518 519 520 521 522 523 524 525

	/* Get the first transport of asoc. */
	pos = asoc->peer.transport_addr_list.next;
	transport = list_entry(pos, struct sctp_transport, transports);

	/* Update any entries that match the peer to be deleted. */
	if (asoc->peer.primary_path == peer)
		sctp_assoc_set_primary(asoc, transport);
	if (asoc->peer.active_path == peer)
		asoc->peer.active_path = transport;
526 527
	if (asoc->peer.retran_path == peer)
		asoc->peer.retran_path = transport;
F
Frank Filz 已提交
528 529 530
	if (asoc->peer.last_data_from == peer)
		asoc->peer.last_data_from = transport;

X
Xin Long 已提交
531 532 533 534 535 536
	if (asoc->strreset_chunk &&
	    asoc->strreset_chunk->transport == peer) {
		asoc->strreset_chunk->transport = transport;
		sctp_transport_reset_reconf_timer(transport);
	}

F
Frank Filz 已提交
537 538 539 540 541 542 543 544
	/* If we remove the transport an INIT was last sent to, set it to
	 * NULL. Combined with the update of the retran path above, this
	 * will cause the next INIT to be sent to the next available
	 * transport, maintaining the cycle.
	 */
	if (asoc->init_last_sent_to == peer)
		asoc->init_last_sent_to = NULL;

545 546 547 548 549 550 551 552
	/* If we remove the transport an SHUTDOWN was last sent to, set it
	 * to NULL. Combined with the update of the retran path above, this
	 * will cause the next SHUTDOWN to be sent to the next available
	 * transport, maintaining the cycle.
	 */
	if (asoc->shutdown_last_sent_to == peer)
		asoc->shutdown_last_sent_to = NULL;

553 554 555 556 557 558 559
	/* If we remove the transport an ASCONF was last sent to, set it to
	 * NULL.
	 */
	if (asoc->addip_last_asconf &&
	    asoc->addip_last_asconf->transport == peer)
		asoc->addip_last_asconf->transport = NULL;

560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578
	/* If we have something on the transmitted list, we have to
	 * save it off.  The best place is the active path.
	 */
	if (!list_empty(&peer->transmitted)) {
		struct sctp_transport *active = asoc->peer.active_path;
		struct sctp_chunk *ch;

		/* Reset the transport of each chunk on this list */
		list_for_each_entry(ch, &peer->transmitted,
					transmitted_list) {
			ch->transport = NULL;
			ch->rtt_in_progress = 0;
		}

		list_splice_tail_init(&peer->transmitted,
					&active->transmitted);

		/* Start a T3 timer here in case it wasn't running so
		 * that these migrated packets have a chance to get
579
		 * retransmitted.
580 581 582 583 584 585 586
		 */
		if (!timer_pending(&active->T3_rtx_timer))
			if (!mod_timer(&active->T3_rtx_timer,
					jiffies + active->rto))
				sctp_transport_hold(active);
	}

F
Frank Filz 已提交
587 588 589 590 591
	asoc->peer.transport_count--;

	sctp_transport_free(peer);
}

L
Linus Torvalds 已提交
592 593 594
/* Add a transport address to an association.  */
struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc,
					   const union sctp_addr *addr,
A
Al Viro 已提交
595
					   const gfp_t gfp,
F
Frank Filz 已提交
596
					   const int peer_state)
L
Linus Torvalds 已提交
597
{
598
	struct net *net = sock_net(asoc->base.sk);
L
Linus Torvalds 已提交
599 600 601 602 603 604 605
	struct sctp_transport *peer;
	struct sctp_sock *sp;
	unsigned short port;

	sp = sctp_sk(asoc->base.sk);

	/* AF_INET and AF_INET6 share common port field. */
606
	port = ntohs(addr->v4.sin_port);
L
Linus Torvalds 已提交
607

608 609
	pr_debug("%s: association:%p addr:%pISpc state:%d\n", __func__,
		 asoc, &addr->sa, peer_state);
F
Frank Filz 已提交
610

L
Linus Torvalds 已提交
611 612 613 614 615 616
	/* Set the port if it has not been set yet.  */
	if (0 == asoc->peer.port)
		asoc->peer.port = port;

	/* Check to see if this is a duplicate. */
	peer = sctp_assoc_lookup_paddr(asoc, addr);
F
Frank Filz 已提交
617
	if (peer) {
618 619 620 621
		/* An UNKNOWN state is only set on transports added by
		 * user in sctp_connectx() call.  Such transports should be
		 * considered CONFIRMED per RFC 4960, Section 5.4.
		 */
622
		if (peer->state == SCTP_UNKNOWN) {
623
			peer->state = SCTP_ACTIVE;
624
		}
L
Linus Torvalds 已提交
625
		return peer;
F
Frank Filz 已提交
626
	}
L
Linus Torvalds 已提交
627

628
	peer = sctp_transport_new(net, addr, gfp);
L
Linus Torvalds 已提交
629 630 631 632 633
	if (!peer)
		return NULL;

	sctp_transport_set_owner(peer, asoc);

634 635 636 637 638 639 640 641
	/* Initialize the peer's heartbeat interval based on the
	 * association configured value.
	 */
	peer->hbinterval = asoc->hbinterval;

	/* Set the path max_retrans.  */
	peer->pathmaxrxt = asoc->pathmaxrxt;

642
	/* And the partial failure retrans threshold */
643 644
	peer->pf_retrans = asoc->pf_retrans;

645 646 647 648
	/* Initialize the peer's SACK delay timeout based on the
	 * association configured value.
	 */
	peer->sackdelay = asoc->sackdelay;
649
	peer->sackfreq = asoc->sackfreq;
650 651 652 653 654 655

	/* Enable/disable heartbeat, SACK delay, and path MTU discovery
	 * based on association setting.
	 */
	peer->param_flags = asoc->param_flags;

656 657
	sctp_transport_route(peer, NULL, sp);

L
Linus Torvalds 已提交
658
	/* Initialize the pmtu of the transport. */
659 660 661 662 663 664
	if (peer->param_flags & SPP_PMTUD_DISABLE) {
		if (asoc->pathmtu)
			peer->pathmtu = asoc->pathmtu;
		else
			peer->pathmtu = SCTP_DEFAULT_MAXSEGMENT;
	}
L
Linus Torvalds 已提交
665 666 667 668 669 670

	/* If this is the first transport addr on this association,
	 * initialize the association PMTU to the peer's PMTU.
	 * If not and the current association PMTU is higher than the new
	 * peer's PMTU, reset the association PMTU to the new peer's PMTU.
	 */
671 672
	if (asoc->pathmtu)
		asoc->pathmtu = min_t(int, peer->pathmtu, asoc->pathmtu);
L
Linus Torvalds 已提交
673
	else
674
		asoc->pathmtu = peer->pathmtu;
L
Linus Torvalds 已提交
675

676 677 678
	pr_debug("%s: association:%p PMTU set to %d\n", __func__, asoc,
		 asoc->pathmtu);

679
	peer->pmtu_pending = 0;
L
Linus Torvalds 已提交
680

681
	asoc->frag_point = sctp_frag_point(asoc, asoc->pathmtu);
L
Linus Torvalds 已提交
682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698

	/* The asoc->peer.port might not be meaningful yet, but
	 * initialize the packet structure anyway.
	 */
	sctp_packet_init(&peer->packet, peer, asoc->base.bind_addr.port,
			 asoc->peer.port);

	/* 7.2.1 Slow-Start
	 *
	 * o The initial cwnd before DATA transmission or after a sufficiently
	 *   long idle period MUST be set to
	 *      min(4*MTU, max(2*MTU, 4380 bytes))
	 *
	 * o The initial value of ssthresh MAY be arbitrarily high
	 *   (for example, implementations MAY use the size of the
	 *   receiver advertised window).
	 */
699
	peer->cwnd = min(4*asoc->pathmtu, max_t(__u32, 2*asoc->pathmtu, 4380));
L
Linus Torvalds 已提交
700 701 702 703 704 705 706 707 708

	/* At this point, we may not have the receiver's advertised window,
	 * so initialize ssthresh to the default value and it will be set
	 * later when we process the INIT.
	 */
	peer->ssthresh = SCTP_DEFAULT_MAXWINDOW;

	peer->partial_bytes_acked = 0;
	peer->flight_size = 0;
709
	peer->burst_limited = 0;
L
Linus Torvalds 已提交
710 711 712

	/* Set the transport's RTO.initial value */
	peer->rto = asoc->rto_initial;
713
	sctp_max_rto(asoc, peer);
L
Linus Torvalds 已提交
714

F
Frank Filz 已提交
715 716 717
	/* Set the peer's active state. */
	peer->state = peer_state;

718 719 720 721 722 723
	/* Add this peer into the transport hashtable */
	if (sctp_hash_transport(peer)) {
		sctp_transport_free(peer);
		return NULL;
	}

L
Linus Torvalds 已提交
724
	/* Attach the remote transport to our asoc.  */
725
	list_add_tail_rcu(&peer->transports, &asoc->peer.transport_addr_list);
F
Frank Filz 已提交
726
	asoc->peer.transport_count++;
L
Linus Torvalds 已提交
727 728 729 730 731 732 733

	/* If we do not yet have a primary path, set one.  */
	if (!asoc->peer.primary_path) {
		sctp_assoc_set_primary(asoc, peer);
		asoc->peer.retran_path = peer;
	}

734 735
	if (asoc->peer.active_path == asoc->peer.retran_path &&
	    peer->state != SCTP_UNCONFIRMED) {
L
Linus Torvalds 已提交
736
		asoc->peer.retran_path = peer;
F
Frank Filz 已提交
737
	}
L
Linus Torvalds 已提交
738 739 740 741 742 743 744 745 746 747 748 749 750 751 752

	return peer;
}

/* Delete a transport address from an association.  */
void sctp_assoc_del_peer(struct sctp_association *asoc,
			 const union sctp_addr *addr)
{
	struct list_head	*pos;
	struct list_head	*temp;
	struct sctp_transport	*transport;

	list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
		transport = list_entry(pos, struct sctp_transport, transports);
		if (sctp_cmp_addr_exact(addr, &transport->ipaddr)) {
F
Frank Filz 已提交
753 754
			/* Do book keeping for removing the peer and free it. */
			sctp_assoc_rm_peer(asoc, transport);
L
Linus Torvalds 已提交
755 756 757 758 759 760 761 762 763 764 765 766 767 768
			break;
		}
	}
}

/* Lookup a transport by address. */
struct sctp_transport *sctp_assoc_lookup_paddr(
					const struct sctp_association *asoc,
					const union sctp_addr *address)
{
	struct sctp_transport *t;

	/* Cycle through all transports searching for a peer address. */

769 770
	list_for_each_entry(t, &asoc->peer.transport_addr_list,
			transports) {
L
Linus Torvalds 已提交
771 772 773 774 775 776 777
		if (sctp_cmp_addr_exact(address, &t->ipaddr))
			return t;
	}

	return NULL;
}

778 779 780 781 782 783 784 785 786 787 788 789 790 791 792
/* Remove all transports except a give one */
void sctp_assoc_del_nonprimary_peers(struct sctp_association *asoc,
				     struct sctp_transport *primary)
{
	struct sctp_transport	*temp;
	struct sctp_transport	*t;

	list_for_each_entry_safe(t, temp, &asoc->peer.transport_addr_list,
				 transports) {
		/* if the current transport is not the primary one, delete it */
		if (t != primary)
			sctp_assoc_rm_peer(asoc, t);
	}
}

L
Linus Torvalds 已提交
793 794 795 796 797 798 799 800 801 802
/* Engage in transport control operations.
 * Mark the transport up or down and send a notification to the user.
 * Select and update the new active and retran paths.
 */
void sctp_assoc_control_transport(struct sctp_association *asoc,
				  struct sctp_transport *transport,
				  sctp_transport_cmd_t command,
				  sctp_sn_error_t error)
{
	struct sctp_ulpevent *event;
803
	struct sockaddr_storage addr;
L
Linus Torvalds 已提交
804
	int spc_state = 0;
805
	bool ulp_notify = true;
L
Linus Torvalds 已提交
806 807 808 809

	/* Record the transition on the transport.  */
	switch (command) {
	case SCTP_TRANSPORT_UP:
810 811 812 813 814 815 816 817 818
		/* If we are moving from UNCONFIRMED state due
		 * to heartbeat success, report the SCTP_ADDR_CONFIRMED
		 * state to the user, otherwise report SCTP_ADDR_AVAILABLE.
		 */
		if (SCTP_UNCONFIRMED == transport->state &&
		    SCTP_HEARTBEAT_SUCCESS == error)
			spc_state = SCTP_ADDR_CONFIRMED;
		else
			spc_state = SCTP_ADDR_AVAILABLE;
819
		/* Don't inform ULP about transition from PF to
820
		 * active state and set cwnd to 1 MTU, see SCTP
821 822 823 824
		 * Quick failover draft section 5.1, point 5
		 */
		if (transport->state == SCTP_PF) {
			ulp_notify = false;
825
			transport->cwnd = asoc->pathmtu;
826
		}
F
Frank Filz 已提交
827
		transport->state = SCTP_ACTIVE;
L
Linus Torvalds 已提交
828 829 830
		break;

	case SCTP_TRANSPORT_DOWN:
831 832 833
		/* If the transport was never confirmed, do not transition it
		 * to inactive state.  Also, release the cached route since
		 * there may be a better route next time.
834 835 836
		 */
		if (transport->state != SCTP_UNCONFIRMED)
			transport->state = SCTP_INACTIVE;
837
		else {
838
			sctp_transport_dst_release(transport);
839
			ulp_notify = false;
840
		}
841

L
Linus Torvalds 已提交
842 843 844
		spc_state = SCTP_ADDR_UNREACHABLE;
		break;

845 846 847 848 849
	case SCTP_TRANSPORT_PF:
		transport->state = SCTP_PF;
		ulp_notify = false;
		break;

L
Linus Torvalds 已提交
850 851
	default:
		return;
852
	}
L
Linus Torvalds 已提交
853

854 855
	/* Generate and send a SCTP_PEER_ADDR_CHANGE notification
	 * to the user.
L
Linus Torvalds 已提交
856
	 */
857 858 859 860
	if (ulp_notify) {
		memset(&addr, 0, sizeof(struct sockaddr_storage));
		memcpy(&addr, &transport->ipaddr,
		       transport->af_specific->sockaddr_len);
861

862 863 864 865 866
		event = sctp_ulpevent_make_peer_addr_change(asoc, &addr,
					0, spc_state, error, GFP_ATOMIC);
		if (event)
			sctp_ulpq_tail_event(&asoc->ulpq, event);
	}
L
Linus Torvalds 已提交
867 868

	/* Select new active and retran paths. */
869
	sctp_select_active_and_retran_path(asoc);
L
Linus Torvalds 已提交
870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924
}

/* Hold a reference to an association. */
void sctp_association_hold(struct sctp_association *asoc)
{
	atomic_inc(&asoc->base.refcnt);
}

/* Release a reference to an association and cleanup
 * if there are no more references.
 */
void sctp_association_put(struct sctp_association *asoc)
{
	if (atomic_dec_and_test(&asoc->base.refcnt))
		sctp_association_destroy(asoc);
}

/* Allocate the next TSN, Transmission Sequence Number, for the given
 * association.
 */
__u32 sctp_association_get_next_tsn(struct sctp_association *asoc)
{
	/* From Section 1.6 Serial Number Arithmetic:
	 * Transmission Sequence Numbers wrap around when they reach
	 * 2**32 - 1.  That is, the next TSN a DATA chunk MUST use
	 * after transmitting TSN = 2*32 - 1 is TSN = 0.
	 */
	__u32 retval = asoc->next_tsn;
	asoc->next_tsn++;
	asoc->unack_data++;

	return retval;
}

/* Compare two addresses to see if they match.  Wildcard addresses
 * only match themselves.
 */
int sctp_cmp_addr_exact(const union sctp_addr *ss1,
			const union sctp_addr *ss2)
{
	struct sctp_af *af;

	af = sctp_get_af_specific(ss1->sa.sa_family);
	if (unlikely(!af))
		return 0;

	return af->cmp_addr(ss1, ss2);
}

/* Return an ecne chunk to get prepended to a packet.
 * Note:  We are sly and return a shared, prealloced chunk.  FIXME:
 * No we don't, but we could/should.
 */
struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc)
{
W
wangweidong 已提交
925 926
	if (!asoc->need_ecne)
		return NULL;
L
Linus Torvalds 已提交
927 928 929 930

	/* Send ECNE if needed.
	 * Not being able to allocate a chunk here is not deadly.
	 */
W
wangweidong 已提交
931
	return sctp_make_ecne(asoc, asoc->last_ecne_tsn);
L
Linus Torvalds 已提交
932 933 934 935 936 937 938 939 940 941 942 943
}

/*
 * Find which transport this TSN was sent on.
 */
struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *asoc,
					     __u32 tsn)
{
	struct sctp_transport *active;
	struct sctp_transport *match;
	struct sctp_transport *transport;
	struct sctp_chunk *chunk;
944
	__be32 key = htonl(tsn);
L
Linus Torvalds 已提交
945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964

	match = NULL;

	/*
	 * FIXME: In general, find a more efficient data structure for
	 * searching.
	 */

	/*
	 * The general strategy is to search each transport's transmitted
	 * list.   Return which transport this TSN lives on.
	 *
	 * Let's be hopeful and check the active_path first.
	 * Another optimization would be to know if there is only one
	 * outbound path and not have to look for the TSN at all.
	 *
	 */

	active = asoc->peer.active_path;

965 966
	list_for_each_entry(chunk, &active->transmitted,
			transmitted_list) {
L
Linus Torvalds 已提交
967 968 969 970 971 972 973 974

		if (key == chunk->subh.data_hdr->tsn) {
			match = active;
			goto out;
		}
	}

	/* If not found, go search all the other transports. */
975 976
	list_for_each_entry(transport, &asoc->peer.transport_addr_list,
			transports) {
L
Linus Torvalds 已提交
977 978

		if (transport == active)
979
			continue;
980 981
		list_for_each_entry(chunk, &transport->transmitted,
				transmitted_list) {
L
Linus Torvalds 已提交
982 983 984 985 986 987 988 989 990 991 992 993
			if (key == chunk->subh.data_hdr->tsn) {
				match = transport;
				goto out;
			}
		}
	}
out:
	return match;
}

/* Is this the association we are looking for? */
struct sctp_transport *sctp_assoc_is_match(struct sctp_association *asoc,
994
					   struct net *net,
L
Linus Torvalds 已提交
995 996 997 998 999
					   const union sctp_addr *laddr,
					   const union sctp_addr *paddr)
{
	struct sctp_transport *transport;

1000
	if ((htons(asoc->base.bind_addr.port) == laddr->v4.sin_port) &&
1001 1002
	    (htons(asoc->peer.port) == paddr->v4.sin_port) &&
	    net_eq(sock_net(asoc->base.sk), net)) {
L
Linus Torvalds 已提交
1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017
		transport = sctp_assoc_lookup_paddr(asoc, paddr);
		if (!transport)
			goto out;

		if (sctp_bind_addr_match(&asoc->base.bind_addr, laddr,
					 sctp_sk(asoc->base.sk)))
			goto out;
	}
	transport = NULL;

out:
	return transport;
}

/* Do delayed input processing.  This is scheduled by sctp_rcv(). */
D
David Howells 已提交
1018
static void sctp_assoc_bh_rcv(struct work_struct *work)
L
Linus Torvalds 已提交
1019
{
D
David Howells 已提交
1020 1021 1022
	struct sctp_association *asoc =
		container_of(work, struct sctp_association,
			     base.inqueue.immediate);
1023
	struct net *net = sock_net(asoc->base.sk);
L
Linus Torvalds 已提交
1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039
	struct sctp_endpoint *ep;
	struct sctp_chunk *chunk;
	struct sctp_inq *inqueue;
	int state;
	sctp_subtype_t subtype;
	int error = 0;

	/* The association should be held so we should be safe. */
	ep = asoc->ep;

	inqueue = &asoc->base.inqueue;
	sctp_association_hold(asoc);
	while (NULL != (chunk = sctp_inq_pop(inqueue))) {
		state = asoc->state;
		subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type);

1040 1041 1042 1043 1044 1045 1046 1047 1048 1049
		/* SCTP-AUTH, Section 6.3:
		 *    The receiver has a list of chunk types which it expects
		 *    to be received only after an AUTH-chunk.  This list has
		 *    been sent to the peer during the association setup.  It
		 *    MUST silently discard these chunks if they are not placed
		 *    after an AUTH chunk in the packet.
		 */
		if (sctp_auth_recv_cid(subtype.chunk, asoc) && !chunk->auth)
			continue;

L
Linus Torvalds 已提交
1050 1051 1052 1053 1054
		/* Remember where the last DATA chunk came from so we
		 * know where to send the SACK.
		 */
		if (sctp_chunk_is_data(chunk))
			asoc->peer.last_data_from = chunk->transport;
1055
		else {
1056
			SCTP_INC_STATS(net, SCTP_MIB_INCTRLCHUNKS);
1057 1058 1059 1060
			asoc->stats.ictrlchunks++;
			if (chunk->chunk_hdr->type == SCTP_CID_SACK)
				asoc->stats.isacks++;
		}
L
Linus Torvalds 已提交
1061 1062

		if (chunk->transport)
1063
			chunk->transport->last_time_heard = ktime_get();
L
Linus Torvalds 已提交
1064 1065

		/* Run through the state machine. */
1066
		error = sctp_do_sm(net, SCTP_EVENT_T_CHUNK, subtype,
L
Linus Torvalds 已提交
1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123
				   state, ep, asoc, chunk, GFP_ATOMIC);

		/* Check to see if the association is freed in response to
		 * the incoming chunk.  If so, get out of the while loop.
		 */
		if (asoc->base.dead)
			break;

		/* If there is an error on chunk, discard this packet. */
		if (error && chunk)
			chunk->pdiscard = 1;
	}
	sctp_association_put(asoc);
}

/* This routine moves an association from its old sk to a new sk.  */
void sctp_assoc_migrate(struct sctp_association *assoc, struct sock *newsk)
{
	struct sctp_sock *newsp = sctp_sk(newsk);
	struct sock *oldsk = assoc->base.sk;

	/* Delete the association from the old endpoint's list of
	 * associations.
	 */
	list_del_init(&assoc->asocs);

	/* Decrement the backlog value for a TCP-style socket. */
	if (sctp_style(oldsk, TCP))
		oldsk->sk_ack_backlog--;

	/* Release references to the old endpoint and the sock.  */
	sctp_endpoint_put(assoc->ep);
	sock_put(assoc->base.sk);

	/* Get a reference to the new endpoint.  */
	assoc->ep = newsp->ep;
	sctp_endpoint_hold(assoc->ep);

	/* Get a reference to the new sock.  */
	assoc->base.sk = newsk;
	sock_hold(assoc->base.sk);

	/* Add the association to the new endpoint's list of associations.  */
	sctp_endpoint_add_asoc(newsp->ep, assoc);
}

/* Update an association (possibly from unexpected COOKIE-ECHO processing).  */
void sctp_assoc_update(struct sctp_association *asoc,
		       struct sctp_association *new)
{
	struct sctp_transport *trans;
	struct list_head *pos, *temp;

	/* Copy in new parameters of peer. */
	asoc->c = new->c;
	asoc->peer.rwnd = new->peer.rwnd;
	asoc->peer.sack_needed = new->peer.sack_needed;
1124
	asoc->peer.auth_capable = new->peer.auth_capable;
L
Linus Torvalds 已提交
1125
	asoc->peer.i = new->peer.i;
1126 1127
	sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
			 asoc->peer.i.initial_tsn, GFP_ATOMIC);
L
Linus Torvalds 已提交
1128 1129 1130 1131

	/* Remove any peer addresses not present in the new association. */
	list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
		trans = list_entry(pos, struct sctp_transport, transports);
1132 1133 1134 1135
		if (!sctp_assoc_lookup_paddr(new, &trans->ipaddr)) {
			sctp_assoc_rm_peer(asoc, trans);
			continue;
		}
1136 1137 1138

		if (asoc->state >= SCTP_STATE_ESTABLISHED)
			sctp_transport_reset(trans);
L
Linus Torvalds 已提交
1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153
	}

	/* If the case is A (association restart), use
	 * initial_tsn as next_tsn. If the case is B, use
	 * current next_tsn in case data sent to peer
	 * has been discarded and needs retransmission.
	 */
	if (asoc->state >= SCTP_STATE_ESTABLISHED) {
		asoc->next_tsn = new->next_tsn;
		asoc->ctsn_ack_point = new->ctsn_ack_point;
		asoc->adv_peer_ack_point = new->adv_peer_ack_point;

		/* Reinitialize SSN for both local streams
		 * and peer's streams.
		 */
1154
		sctp_stream_clear(asoc->stream);
L
Linus Torvalds 已提交
1155

1156 1157 1158 1159 1160 1161
		/* Flush the ULP reassembly and ordered queue.
		 * Any data there will now be stale and will
		 * cause problems.
		 */
		sctp_ulpq_flush(&asoc->ulpq);

1162 1163 1164 1165 1166 1167
		/* reset the overall association error count so
		 * that the restarted association doesn't get torn
		 * down on the next retransmission timer.
		 */
		asoc->overall_error_count = 0;

L
Linus Torvalds 已提交
1168 1169
	} else {
		/* Add any peer addresses from the new association. */
1170 1171
		list_for_each_entry(trans, &new->peer.transport_addr_list,
				transports) {
L
Linus Torvalds 已提交
1172 1173
			if (!sctp_assoc_lookup_paddr(asoc, &trans->ipaddr))
				sctp_assoc_add_peer(asoc, &trans->ipaddr,
1174
						    GFP_ATOMIC, trans->state);
L
Linus Torvalds 已提交
1175 1176 1177 1178
		}

		asoc->ctsn_ack_point = asoc->next_tsn - 1;
		asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
1179 1180 1181
		if (!asoc->stream) {
			asoc->stream = new->stream;
			new->stream = NULL;
L
Linus Torvalds 已提交
1182
		}
1183 1184 1185 1186 1187 1188 1189

		if (!asoc->assoc_id) {
			/* get a new association id since we don't have one
			 * yet.
			 */
			sctp_assoc_set_id(asoc, GFP_ATOMIC);
		}
L
Linus Torvalds 已提交
1190
	}
1191

1192
	/* SCTP-AUTH: Save the peer parameters from the new associations
1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207
	 * and also move the association shared keys over
	 */
	kfree(asoc->peer.peer_random);
	asoc->peer.peer_random = new->peer.peer_random;
	new->peer.peer_random = NULL;

	kfree(asoc->peer.peer_chunks);
	asoc->peer.peer_chunks = new->peer.peer_chunks;
	new->peer.peer_chunks = NULL;

	kfree(asoc->peer.peer_hmacs);
	asoc->peer.peer_hmacs = new->peer.peer_hmacs;
	new->peer.peer_hmacs = NULL;

	sctp_auth_asoc_init_active_key(asoc, GFP_ATOMIC);
L
Linus Torvalds 已提交
1208 1209 1210
}

/* Update the retran path for sending a retransmitted packet.
1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233
 * See also RFC4960, 6.4. Multi-Homed SCTP Endpoints:
 *
 *   When there is outbound data to send and the primary path
 *   becomes inactive (e.g., due to failures), or where the
 *   SCTP user explicitly requests to send data to an
 *   inactive destination transport address, before reporting
 *   an error to its ULP, the SCTP endpoint should try to send
 *   the data to an alternate active destination transport
 *   address if one exists.
 *
 *   When retransmitting data that timed out, if the endpoint
 *   is multihomed, it should consider each source-destination
 *   address pair in its retransmission selection policy.
 *   When retransmitting timed-out data, the endpoint should
 *   attempt to pick the most divergent source-destination
 *   pair from the original source-destination pair to which
 *   the packet was transmitted.
 *
 *   Note: Rules for picking the most divergent source-destination
 *   pair are an implementation decision and are not specified
 *   within this document.
 *
 * Our basic strategy is to round-robin transports in priorities
1234
 * according to sctp_trans_score() e.g., if no such
1235 1236
 * transport with state SCTP_ACTIVE exists, round-robin through
 * SCTP_UNKNOWN, etc. You get the picture.
L
Linus Torvalds 已提交
1237
 */
1238
static u8 sctp_trans_score(const struct sctp_transport *trans)
L
Linus Torvalds 已提交
1239
{
1240 1241 1242 1243 1244 1245 1246 1247 1248 1249
	switch (trans->state) {
	case SCTP_ACTIVE:
		return 3;	/* best case */
	case SCTP_UNKNOWN:
		return 2;
	case SCTP_PF:
		return 1;
	default: /* case SCTP_INACTIVE */
		return 0;	/* worst case */
	}
1250
}
L
Linus Torvalds 已提交
1251

1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265
static struct sctp_transport *sctp_trans_elect_tie(struct sctp_transport *trans1,
						   struct sctp_transport *trans2)
{
	if (trans1->error_count > trans2->error_count) {
		return trans2;
	} else if (trans1->error_count == trans2->error_count &&
		   ktime_after(trans2->last_time_heard,
			       trans1->last_time_heard)) {
		return trans2;
	} else {
		return trans1;
	}
}

1266 1267 1268
static struct sctp_transport *sctp_trans_elect_best(struct sctp_transport *curr,
						    struct sctp_transport *best)
{
1269 1270
	u8 score_curr, score_best;

1271
	if (best == NULL || curr == best)
1272
		return curr;
G
Gui Jianfeng 已提交
1273

1274 1275 1276 1277 1278 1279 1280 1281 1282 1283
	score_curr = sctp_trans_score(curr);
	score_best = sctp_trans_score(best);

	/* First, try a score-based selection if both transport states
	 * differ. If we're in a tie, lets try to make a more clever
	 * decision here based on error counts and last time heard.
	 */
	if (score_curr > score_best)
		return curr;
	else if (score_curr == score_best)
1284
		return sctp_trans_elect_tie(best, curr);
1285 1286
	else
		return best;
1287
}
L
Linus Torvalds 已提交
1288

1289 1290 1291 1292
void sctp_assoc_update_retran_path(struct sctp_association *asoc)
{
	struct sctp_transport *trans = asoc->peer.retran_path;
	struct sctp_transport *trans_next = NULL;
L
Linus Torvalds 已提交
1293

1294 1295 1296 1297 1298 1299 1300 1301 1302
	/* We're done as we only have the one and only path. */
	if (asoc->peer.transport_count == 1)
		return;
	/* If active_path and retran_path are the same and active,
	 * then this is the only active path. Use it.
	 */
	if (asoc->peer.active_path == asoc->peer.retran_path &&
	    asoc->peer.active_path->state == SCTP_ACTIVE)
		return;
L
Linus Torvalds 已提交
1303

1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314
	/* Iterate from retran_path's successor back to retran_path. */
	for (trans = list_next_entry(trans, transports); 1;
	     trans = list_next_entry(trans, transports)) {
		/* Manually skip the head element. */
		if (&trans->transports == &asoc->peer.transport_addr_list)
			continue;
		if (trans->state == SCTP_UNCONFIRMED)
			continue;
		trans_next = sctp_trans_elect_best(trans, trans_next);
		/* Active is good enough for immediate return. */
		if (trans_next->state == SCTP_ACTIVE)
G
Gui Jianfeng 已提交
1315
			break;
1316 1317
		/* We've reached the end, time to update path. */
		if (trans == asoc->peer.retran_path)
L
Linus Torvalds 已提交
1318 1319 1320
			break;
	}

1321
	asoc->peer.retran_path = trans_next;
F
Frank Filz 已提交
1322

1323 1324
	pr_debug("%s: association:%p updated new path to addr:%pISpc\n",
		 __func__, asoc, &asoc->peer.retran_path->ipaddr.sa);
F
Frank Filz 已提交
1325 1326
}

1327 1328 1329
static void sctp_select_active_and_retran_path(struct sctp_association *asoc)
{
	struct sctp_transport *trans, *trans_pri = NULL, *trans_sec = NULL;
1330
	struct sctp_transport *trans_pf = NULL;
1331 1332 1333 1334

	/* Look for the two most recently used active transports. */
	list_for_each_entry(trans, &asoc->peer.transport_addr_list,
			    transports) {
1335
		/* Skip uninteresting transports. */
1336
		if (trans->state == SCTP_INACTIVE ||
1337
		    trans->state == SCTP_UNCONFIRMED)
1338
			continue;
1339 1340 1341 1342 1343 1344 1345 1346
		/* Keep track of the best PF transport from our
		 * list in case we don't find an active one.
		 */
		if (trans->state == SCTP_PF) {
			trans_pf = sctp_trans_elect_best(trans, trans_pf);
			continue;
		}
		/* For active transports, pick the most recent ones. */
1347
		if (trans_pri == NULL ||
1348 1349
		    ktime_after(trans->last_time_heard,
				trans_pri->last_time_heard)) {
1350 1351 1352
			trans_sec = trans_pri;
			trans_pri = trans;
		} else if (trans_sec == NULL ||
1353 1354
			   ktime_after(trans->last_time_heard,
				       trans_sec->last_time_heard)) {
1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381
			trans_sec = trans;
		}
	}

	/* RFC 2960 6.4 Multi-Homed SCTP Endpoints
	 *
	 * By default, an endpoint should always transmit to the primary
	 * path, unless the SCTP user explicitly specifies the
	 * destination transport address (and possibly source transport
	 * address) to use. [If the primary is active but not most recent,
	 * bump the most recently used transport.]
	 */
	if ((asoc->peer.primary_path->state == SCTP_ACTIVE ||
	     asoc->peer.primary_path->state == SCTP_UNKNOWN) &&
	     asoc->peer.primary_path != trans_pri) {
		trans_sec = trans_pri;
		trans_pri = asoc->peer.primary_path;
	}

	/* We did not find anything useful for a possible retransmission
	 * path; either primary path that we found is the the same as
	 * the current one, or we didn't generally find an active one.
	 */
	if (trans_sec == NULL)
		trans_sec = trans_pri;

	/* If we failed to find a usable transport, just camp on the
1382
	 * active or pick a PF iff it's the better choice.
1383 1384
	 */
	if (trans_pri == NULL) {
1385 1386
		trans_pri = sctp_trans_elect_best(asoc->peer.active_path, trans_pf);
		trans_sec = trans_pri;
1387 1388 1389 1390 1391 1392 1393
	}

	/* Set the active and retran transports. */
	asoc->peer.active_path = trans_pri;
	asoc->peer.retran_path = trans_sec;
}

1394 1395 1396
struct sctp_transport *
sctp_assoc_choose_alter_transport(struct sctp_association *asoc,
				  struct sctp_transport *last_sent_to)
F
Frank Filz 已提交
1397
{
1398 1399
	/* If this is the first time packet is sent, use the active path,
	 * else use the retran path. If the last packet was sent over the
F
Frank Filz 已提交
1400 1401
	 * retran path, update the retran path and use it.
	 */
1402
	if (last_sent_to == NULL) {
L
Linus Torvalds 已提交
1403
		return asoc->peer.active_path;
1404
	} else {
1405
		if (last_sent_to == asoc->peer.retran_path)
L
Linus Torvalds 已提交
1406
			sctp_assoc_update_retran_path(asoc);
1407

L
Linus Torvalds 已提交
1408 1409 1410 1411 1412 1413 1414
		return asoc->peer.retran_path;
	}
}

/* Update the association's pmtu and frag_point by going through all the
 * transports. This routine is called when a transport's PMTU has changed.
 */
1415
void sctp_assoc_sync_pmtu(struct sock *sk, struct sctp_association *asoc)
L
Linus Torvalds 已提交
1416 1417 1418 1419 1420 1421 1422 1423
{
	struct sctp_transport *t;
	__u32 pmtu = 0;

	if (!asoc)
		return;

	/* Get the lowest pmtu of all the transports. */
1424 1425
	list_for_each_entry(t, &asoc->peer.transport_addr_list,
				transports) {
1426
		if (t->pmtu_pending && t->dst) {
1427
			sctp_transport_update_pmtu(sk, t,
1428
						   SCTP_TRUNC4(dst_mtu(t->dst)));
1429 1430
			t->pmtu_pending = 0;
		}
1431 1432
		if (!pmtu || (t->pathmtu < pmtu))
			pmtu = t->pathmtu;
L
Linus Torvalds 已提交
1433 1434 1435
	}

	if (pmtu) {
1436
		asoc->pathmtu = pmtu;
1437
		asoc->frag_point = sctp_frag_point(asoc, pmtu);
L
Linus Torvalds 已提交
1438 1439
	}

1440 1441
	pr_debug("%s: asoc:%p, pmtu:%d, frag_point:%d\n", __func__, asoc,
		 asoc->pathmtu, asoc->frag_point);
L
Linus Torvalds 已提交
1442 1443 1444
}

/* Should we send a SACK to update our peer? */
1445
static inline bool sctp_peer_needs_update(struct sctp_association *asoc)
L
Linus Torvalds 已提交
1446
{
1447
	struct net *net = sock_net(asoc->base.sk);
L
Linus Torvalds 已提交
1448 1449 1450 1451 1452 1453
	switch (asoc->state) {
	case SCTP_STATE_ESTABLISHED:
	case SCTP_STATE_SHUTDOWN_PENDING:
	case SCTP_STATE_SHUTDOWN_RECEIVED:
	case SCTP_STATE_SHUTDOWN_SENT:
		if ((asoc->rwnd > asoc->a_rwnd) &&
1454
		    ((asoc->rwnd - asoc->a_rwnd) >= max_t(__u32,
1455
			   (asoc->base.sk->sk_rcvbuf >> net->sctp.rwnd_upd_shift),
1456
			   asoc->pathmtu)))
1457
			return true;
L
Linus Torvalds 已提交
1458 1459 1460 1461
		break;
	default:
		break;
	}
1462
	return false;
L
Linus Torvalds 已提交
1463 1464
}

1465 1466
/* Increase asoc's rwnd by len and send any window update SACK if needed. */
void sctp_assoc_rwnd_increase(struct sctp_association *asoc, unsigned int len)
L
Linus Torvalds 已提交
1467 1468 1469 1470
{
	struct sctp_chunk *sack;
	struct timer_list *timer;

1471 1472 1473 1474 1475 1476 1477 1478 1479 1480
	if (asoc->rwnd_over) {
		if (asoc->rwnd_over >= len) {
			asoc->rwnd_over -= len;
		} else {
			asoc->rwnd += (len - asoc->rwnd_over);
			asoc->rwnd_over = 0;
		}
	} else {
		asoc->rwnd += len;
	}
L
Linus Torvalds 已提交
1481

1482 1483 1484 1485 1486
	/* If we had window pressure, start recovering it
	 * once our rwnd had reached the accumulated pressure
	 * threshold.  The idea is to recover slowly, but up
	 * to the initial advertised window.
	 */
1487
	if (asoc->rwnd_press) {
1488 1489 1490 1491
		int change = min(asoc->pathmtu, asoc->rwnd_press);
		asoc->rwnd += change;
		asoc->rwnd_press -= change;
	}
1492

1493 1494 1495
	pr_debug("%s: asoc:%p rwnd increased by %d to (%u, %u) - %u\n",
		 __func__, asoc, len, asoc->rwnd, asoc->rwnd_over,
		 asoc->a_rwnd);
L
Linus Torvalds 已提交
1496 1497 1498 1499 1500 1501

	/* Send a window update SACK if the rwnd has increased by at least the
	 * minimum of the association's PMTU and half of the receive buffer.
	 * The algorithm used is similar to the one described in
	 * Section 4.2.3.3 of RFC 1122.
	 */
1502
	if (sctp_peer_needs_update(asoc)) {
L
Linus Torvalds 已提交
1503
		asoc->a_rwnd = asoc->rwnd;
1504 1505 1506 1507 1508

		pr_debug("%s: sending window update SACK- asoc:%p rwnd:%u "
			 "a_rwnd:%u\n", __func__, asoc, asoc->rwnd,
			 asoc->a_rwnd);

L
Linus Torvalds 已提交
1509 1510 1511 1512 1513 1514
		sack = sctp_make_sack(asoc);
		if (!sack)
			return;

		asoc->peer.sack_needed = 0;

1515
		sctp_outq_tail(&asoc->outqueue, sack, GFP_ATOMIC);
L
Linus Torvalds 已提交
1516 1517 1518

		/* Stop the SACK timer.  */
		timer = &asoc->timers[SCTP_EVENT_TIMEOUT_SACK];
1519
		if (del_timer(timer))
L
Linus Torvalds 已提交
1520 1521 1522 1523
			sctp_association_put(asoc);
	}
}

1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554
/* Decrease asoc's rwnd by len. */
void sctp_assoc_rwnd_decrease(struct sctp_association *asoc, unsigned int len)
{
	int rx_count;
	int over = 0;

	if (unlikely(!asoc->rwnd || asoc->rwnd_over))
		pr_debug("%s: association:%p has asoc->rwnd:%u, "
			 "asoc->rwnd_over:%u!\n", __func__, asoc,
			 asoc->rwnd, asoc->rwnd_over);

	if (asoc->ep->rcvbuf_policy)
		rx_count = atomic_read(&asoc->rmem_alloc);
	else
		rx_count = atomic_read(&asoc->base.sk->sk_rmem_alloc);

	/* If we've reached or overflowed our receive buffer, announce
	 * a 0 rwnd if rwnd would still be positive.  Store the
	 * the potential pressure overflow so that the window can be restored
	 * back to original value.
	 */
	if (rx_count >= asoc->base.sk->sk_rcvbuf)
		over = 1;

	if (asoc->rwnd >= len) {
		asoc->rwnd -= len;
		if (over) {
			asoc->rwnd_press += asoc->rwnd;
			asoc->rwnd = 0;
		}
	} else {
1555
		asoc->rwnd_over += len - asoc->rwnd;
1556 1557 1558 1559 1560 1561 1562
		asoc->rwnd = 0;
	}

	pr_debug("%s: asoc:%p rwnd decreased by %d to (%u, %u, %u)\n",
		 __func__, asoc, len, asoc->rwnd, asoc->rwnd_over,
		 asoc->rwnd_press);
}
L
Linus Torvalds 已提交
1563 1564 1565 1566

/* Build the bind address list for the association based on info from the
 * local endpoint and the remote peer.
 */
A
Alexey Dobriyan 已提交
1567
int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
1568
				     sctp_scope_t scope, gfp_t gfp)
L
Linus Torvalds 已提交
1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580
{
	int flags;

	/* Use scoping rules to determine the subset of addresses from
	 * the endpoint.
	 */
	flags = (PF_INET6 == asoc->base.sk->sk_family) ? SCTP_ADDR6_ALLOWED : 0;
	if (asoc->peer.ipv4_address)
		flags |= SCTP_ADDR4_PEERSUPP;
	if (asoc->peer.ipv6_address)
		flags |= SCTP_ADDR6_PEERSUPP;

1581 1582
	return sctp_bind_addr_copy(sock_net(asoc->base.sk),
				   &asoc->base.bind_addr,
L
Linus Torvalds 已提交
1583 1584 1585 1586 1587 1588
				   &asoc->ep->base.bind_addr,
				   scope, gfp, flags);
}

/* Build the association's bind address list from the cookie.  */
int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *asoc,
A
Alexey Dobriyan 已提交
1589
					 struct sctp_cookie *cookie,
A
Al Viro 已提交
1590
					 gfp_t gfp)
L
Linus Torvalds 已提交
1591 1592 1593 1594 1595 1596 1597 1598 1599
{
	int var_size2 = ntohs(cookie->peer_init->chunk_hdr.length);
	int var_size3 = cookie->raw_addr_list_len;
	__u8 *raw = (__u8 *)cookie->peer_init + var_size2;

	return sctp_raw_to_bind_addrs(&asoc->base.bind_addr, raw, var_size3,
				      asoc->ep->base.bind_addr.port, gfp);
}

1600 1601
/* Lookup laddr in the bind address list of an association. */
int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
L
Linus Torvalds 已提交
1602 1603
			    const union sctp_addr *laddr)
{
1604
	int found = 0;
L
Linus Torvalds 已提交
1605 1606 1607

	if ((asoc->base.bind_addr.port == ntohs(laddr->v4.sin_port)) &&
	    sctp_bind_addr_match(&asoc->base.bind_addr, laddr,
1608
				 sctp_sk(asoc->base.sk)))
L
Linus Torvalds 已提交
1609 1610 1611 1612
		found = 1;

	return found;
}
1613 1614 1615 1616

/* Set an association id for a given association */
int sctp_assoc_set_id(struct sctp_association *asoc, gfp_t gfp)
{
1617
	bool preload = gfpflags_allow_blocking(gfp);
T
Tejun Heo 已提交
1618
	int ret;
1619 1620 1621

	/* If the id is already assigned, keep it. */
	if (asoc->assoc_id)
T
Tejun Heo 已提交
1622
		return 0;
1623

T
Tejun Heo 已提交
1624 1625
	if (preload)
		idr_preload(gfp);
1626
	spin_lock_bh(&sctp_assocs_id_lock);
1627 1628
	/* 0 is not a valid assoc_id, must be >= 1 */
	ret = idr_alloc_cyclic(&sctp_assocs_id, asoc, 1, 0, GFP_NOWAIT);
1629
	spin_unlock_bh(&sctp_assocs_id_lock);
T
Tejun Heo 已提交
1630 1631 1632 1633
	if (preload)
		idr_preload_end();
	if (ret < 0)
		return ret;
1634

T
Tejun Heo 已提交
1635 1636
	asoc->assoc_id = (sctp_assoc_t)ret;
	return 0;
1637
}
1638

1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650
/* Free the ASCONF queue */
static void sctp_assoc_free_asconf_queue(struct sctp_association *asoc)
{
	struct sctp_chunk *asconf;
	struct sctp_chunk *tmp;

	list_for_each_entry_safe(asconf, tmp, &asoc->addip_chunk_list, list) {
		list_del_init(&asconf->list);
		sctp_chunk_free(asconf);
	}
}

1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669
/* Free asconf_ack cache */
static void sctp_assoc_free_asconf_acks(struct sctp_association *asoc)
{
	struct sctp_chunk *ack;
	struct sctp_chunk *tmp;

	list_for_each_entry_safe(ack, tmp, &asoc->asconf_ack_list,
				transmitted_list) {
		list_del_init(&ack->transmitted_list);
		sctp_chunk_free(ack);
	}
}

/* Clean up the ASCONF_ACK queue */
void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc)
{
	struct sctp_chunk *ack;
	struct sctp_chunk *tmp;

L
Lucas De Marchi 已提交
1670
	/* We can remove all the entries from the queue up to
1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688
	 * the "Peer-Sequence-Number".
	 */
	list_for_each_entry_safe(ack, tmp, &asoc->asconf_ack_list,
				transmitted_list) {
		if (ack->subh.addip_hdr->serial ==
				htonl(asoc->peer.addip_serial))
			break;

		list_del_init(&ack->transmitted_list);
		sctp_chunk_free(ack);
	}
}

/* Find the ASCONF_ACK whose serial number matches ASCONF */
struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
					const struct sctp_association *asoc,
					__be32 serial)
{
1689
	struct sctp_chunk *ack;
1690 1691 1692 1693 1694

	/* Walk through the list of cached ASCONF-ACKs and find the
	 * ack chunk whose serial number matches that of the request.
	 */
	list_for_each_entry(ack, &asoc->asconf_ack_list, transmitted_list) {
1695 1696
		if (sctp_chunk_pending(ack))
			continue;
1697 1698
		if (ack->subh.addip_hdr->serial == serial) {
			sctp_chunk_hold(ack);
1699
			return ack;
1700 1701 1702
		}
	}

1703
	return NULL;
1704
}
1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717

void sctp_asconf_queue_teardown(struct sctp_association *asoc)
{
	/* Free any cached ASCONF_ACK chunk. */
	sctp_assoc_free_asconf_acks(asoc);

	/* Free the ASCONF queue. */
	sctp_assoc_free_asconf_queue(asoc);

	/* Free any cached ASCONF chunk. */
	if (asoc->addip_last_asconf)
		sctp_chunk_free(asoc->addip_last_asconf);
}