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Vlad Yasevich60c778b2008-01-11 09:57:09 -05001/* SCTP kernel implementation
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999-2000 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 * Copyright (c) 2001 Intel Corp.
6 * Copyright (c) 2001 La Monte H.P. Yarroll
7 *
Vlad Yasevich60c778b2008-01-11 09:57:09 -05008 * This file is part of the SCTP kernel implementation
Linus Torvalds1da177e2005-04-16 15:20:36 -07009 *
10 * This module provides the abstraction for an SCTP association.
11 *
Vlad Yasevich60c778b2008-01-11 09:57:09 -050012 * This SCTP implementation is free software;
Linus Torvalds1da177e2005-04-16 15:20:36 -070013 * 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 *
Vlad Yasevich60c778b2008-01-11 09:57:09 -050018 * This SCTP implementation is distributed in the hope that it
Linus Torvalds1da177e2005-04-16 15:20:36 -070019 * 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
Jeff Kirsher4b2f13a2013-12-06 06:28:48 -080025 * along with GNU CC; see the file COPYING. If not, see
26 * <http://www.gnu.org/licenses/>.
Linus Torvalds1da177e2005-04-16 15:20:36 -070027 *
28 * Please send any bug reports or fixes you make to the
29 * email address(es):
Daniel Borkmann91705c62013-07-23 14:51:47 +020030 * lksctp developers <linux-sctp@vger.kernel.org>
Linus Torvalds1da177e2005-04-16 15:20:36 -070031 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070032 * 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@us.ibm.com>
36 * Xingang Guo <xingang.guo@intel.com>
37 * Hui Huang <hui.huang@nokia.com>
38 * Sridhar Samudrala <sri@us.ibm.com>
39 * Daisy Chang <daisyc@us.ibm.com>
40 * Ryan Layer <rmlayer@us.ibm.com>
41 * Kevin Gao <kevin.gao@intel.com>
Linus Torvalds1da177e2005-04-16 15:20:36 -070042 */
43
Joe Perches145ce502010-08-24 13:21:08 +000044#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
45
Linus Torvalds1da177e2005-04-16 15:20:36 -070046#include <linux/types.h>
47#include <linux/fcntl.h>
48#include <linux/poll.h>
49#include <linux/init.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070050
51#include <linux/slab.h>
52#include <linux/in.h>
53#include <net/ipv6.h>
54#include <net/sctp/sctp.h>
55#include <net/sctp/sm.h>
56
57/* Forward declarations for internal functions. */
Daniel Borkmannb82e8f32014-06-11 18:19:29 +020058static void sctp_select_active_and_retran_path(struct sctp_association *asoc);
David Howellsc4028952006-11-22 14:57:56 +000059static void sctp_assoc_bh_rcv(struct work_struct *work);
Vlad Yasevicha08de642007-12-20 14:11:47 -080060static void sctp_assoc_free_asconf_acks(struct sctp_association *asoc);
Wei Yongjun8b4472c2011-05-24 21:48:02 +000061static void sctp_assoc_free_asconf_queue(struct sctp_association *asoc);
Linus Torvalds1da177e2005-04-16 15:20:36 -070062
Linus Torvalds1da177e2005-04-16 15:20:36 -070063/* 1st Level Abstractions. */
64
65/* Initialize a new association from provided memory. */
66static struct sctp_association *sctp_association_init(struct sctp_association *asoc,
67 const struct sctp_endpoint *ep,
68 const struct sock *sk,
69 sctp_scope_t scope,
Al Virodd0fc662005-10-07 07:46:04 +010070 gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -070071{
Eric W. Biedermane1fc3b12012-08-07 07:29:57 +000072 struct net *net = sock_net(sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -070073 struct sctp_sock *sp;
74 int i;
Vlad Yasevicha29a5bd2007-09-16 19:31:35 -070075 sctp_paramhdr_t *p;
76 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -070077
78 /* Retrieve the SCTP per socket area. */
79 sp = sctp_sk((struct sock *)sk);
80
Linus Torvalds1da177e2005-04-16 15:20:36 -070081 /* Discarding const is appropriate here. */
82 asoc->ep = (struct sctp_endpoint *)ep;
Linus Torvalds1da177e2005-04-16 15:20:36 -070083 asoc->base.sk = (struct sock *)sk;
Daniel Borkmann2e0c9e72013-06-14 18:24:07 +020084
85 sctp_endpoint_hold(asoc->ep);
Linus Torvalds1da177e2005-04-16 15:20:36 -070086 sock_hold(asoc->base.sk);
87
88 /* Initialize the common base substructure. */
89 asoc->base.type = SCTP_EP_TYPE_ASSOCIATION;
90
91 /* Initialize the object handling fields. */
92 atomic_set(&asoc->base.refcnt, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -070093
94 /* Initialize the bind addr area. */
95 sctp_bind_addr_init(&asoc->base.bind_addr, ep->base.bind_addr.port);
Linus Torvalds1da177e2005-04-16 15:20:36 -070096
97 asoc->state = SCTP_STATE_CLOSED;
Daniel Borkmann52db8822013-06-25 18:17:27 +020098 asoc->cookie_life = ms_to_ktime(sp->assocparams.sasoc_cookie_life);
Vlad Yasevichf68b2e02009-09-04 18:21:00 -040099 asoc->user_frag = sp->user_frag;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100
101 /* Set the association max_retrans and RTO values from the
102 * socket values.
103 */
104 asoc->max_retrans = sp->assocparams.sasoc_asocmaxrxt;
Eric W. Biedermane1fc3b12012-08-07 07:29:57 +0000105 asoc->pf_retrans = net->sctp.pf_retrans;
Neil Horman5aa93bc2012-07-21 07:56:07 +0000106
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107 asoc->rto_initial = msecs_to_jiffies(sp->rtoinfo.srto_initial);
108 asoc->rto_max = msecs_to_jiffies(sp->rtoinfo.srto_max);
109 asoc->rto_min = msecs_to_jiffies(sp->rtoinfo.srto_min);
110
Frank Filz52ccb8e2005-12-22 11:36:46 -0800111 /* Initialize the association's heartbeat interval based on the
112 * sock configured value.
113 */
114 asoc->hbinterval = msecs_to_jiffies(sp->hbinterval);
115
116 /* Initialize path max retrans value. */
117 asoc->pathmaxrxt = sp->pathmaxrxt;
118
119 /* Initialize default path MTU. */
120 asoc->pathmtu = sp->pathmtu;
121
122 /* Set association default SACK delay */
123 asoc->sackdelay = msecs_to_jiffies(sp->sackdelay);
Wei Yongjund364d922008-05-09 15:13:26 -0700124 asoc->sackfreq = sp->sackfreq;
Frank Filz52ccb8e2005-12-22 11:36:46 -0800125
126 /* Set the association default flags controlling
127 * Heartbeat, SACK delay, and Path MTU Discovery.
128 */
129 asoc->param_flags = sp->param_flags;
130
wangweidong9d2c8812013-12-06 09:36:30 +0800131 /* Initialize the maximum number of new data packets that can be sent
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 * in a burst.
133 */
Vlad Yasevich70331572007-03-23 11:34:36 -0700134 asoc->max_burst = sp->max_burst;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135
Vladislav Yasevich1e7d3d92005-11-11 16:06:16 -0800136 /* initialize association timers */
Vladislav Yasevich1e7d3d92005-11-11 16:06:16 -0800137 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] = asoc->rto_initial;
138 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] = asoc->rto_initial;
139 asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = asoc->rto_initial;
Vladislav Yasevich1e7d3d92005-11-11 16:06:16 -0800140
141 /* sctpimpguide Section 2.12.2
142 * If the 'T5-shutdown-guard' timer is used, it SHOULD be set to the
143 * recommended value of 5 times 'RTO.Max'.
144 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900145 asoc->timeouts[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD]
Vladislav Yasevich1e7d3d92005-11-11 16:06:16 -0800146 = 5 * asoc->rto_max;
147
Frank Filz52ccb8e2005-12-22 11:36:46 -0800148 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] = asoc->sackdelay;
Neil Horman9f70f462013-12-10 06:48:15 -0500149 asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE] = sp->autoclose * HZ;
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900150
Uwe Kleine-König421f91d2010-06-11 12:17:00 +0200151 /* Initializes the timers */
Pavel Emelyanovb24b8a22008-01-23 21:20:07 -0800152 for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i)
153 setup_timer(&asoc->timers[i], sctp_timer_events[i],
154 (unsigned long)asoc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155
156 /* Pull default initialization values from the sock options.
157 * Note: This assumes that the values have already been
158 * validated in the sock.
159 */
160 asoc->c.sinit_max_instreams = sp->initmsg.sinit_max_instreams;
161 asoc->c.sinit_num_ostreams = sp->initmsg.sinit_num_ostreams;
162 asoc->max_init_attempts = sp->initmsg.sinit_max_attempts;
163
164 asoc->max_init_timeo =
165 msecs_to_jiffies(sp->initmsg.sinit_max_init_timeo);
166
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167 /* Set the local window size for receive.
168 * This is also the rcvbuf space per association.
169 * RFC 6 - A SCTP receiver MUST be able to receive a minimum of
170 * 1500 bytes in one SCTP packet.
171 */
Neil Horman049b3ff2005-11-11 16:08:24 -0800172 if ((sk->sk_rcvbuf/2) < SCTP_DEFAULT_MINWINDOW)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173 asoc->rwnd = SCTP_DEFAULT_MINWINDOW;
174 else
Neil Horman049b3ff2005-11-11 16:08:24 -0800175 asoc->rwnd = sk->sk_rcvbuf/2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176
177 asoc->a_rwnd = asoc->rwnd;
178
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179 /* Use my own max window until I learn something better. */
180 asoc->peer.rwnd = SCTP_DEFAULT_MAXWINDOW;
181
Neil Horman049b3ff2005-11-11 16:08:24 -0800182 /* Initialize the receive memory counter */
183 atomic_set(&asoc->rmem_alloc, 0);
184
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185 init_waitqueue_head(&asoc->wait);
186
187 asoc->c.my_vtag = sctp_generate_tag(ep);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188 asoc->c.my_port = ep->base.bind_addr.port;
189
190 asoc->c.initial_tsn = sctp_generate_tsn(ep);
191
192 asoc->next_tsn = asoc->c.initial_tsn;
193
194 asoc->ctsn_ack_point = asoc->next_tsn - 1;
195 asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
196 asoc->highest_sacked = asoc->ctsn_ack_point;
197 asoc->last_cwr_tsn = asoc->ctsn_ack_point;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 /* ADDIP Section 4.1 Asconf Chunk Procedures
200 *
201 * When an endpoint has an ASCONF signaled change to be sent to the
202 * remote endpoint it should do the following:
203 * ...
204 * A2) a serial number should be assigned to the chunk. The serial
205 * number SHOULD be a monotonically increasing number. The serial
206 * numbers SHOULD be initialized at the start of the
207 * association to the same value as the initial TSN.
208 */
209 asoc->addip_serial = asoc->c.initial_tsn;
210
David S. Miller79af02c2005-07-08 21:47:49 -0700211 INIT_LIST_HEAD(&asoc->addip_chunk_list);
Vlad Yasevicha08de642007-12-20 14:11:47 -0800212 INIT_LIST_HEAD(&asoc->asconf_ack_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213
214 /* Make an empty list of remote transport addresses. */
215 INIT_LIST_HEAD(&asoc->peer.transport_addr_list);
216
217 /* RFC 2960 5.1 Normal Establishment of an Association
218 *
219 * After the reception of the first data chunk in an
220 * association the endpoint must immediately respond with a
221 * sack to acknowledge the data chunk. Subsequent
222 * acknowledgements should be done as described in Section
223 * 6.2.
224 *
225 * [We implement this by telling a new association that it
226 * already received one packet.]
227 */
228 asoc->peer.sack_needed = 1;
Neil Horman42448542012-06-30 03:04:26 +0000229 asoc->peer.sack_generation = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230
Vlad Yasevich73d9c4f2007-10-24 17:24:26 -0400231 /* Assume that the peer will tell us if he recognizes ASCONF
232 * as part of INIT exchange.
wangweidong9d2c8812013-12-06 09:36:30 +0800233 * The sctp_addip_noauth option is there for backward compatibility
Vlad Yasevich73d9c4f2007-10-24 17:24:26 -0400234 * and will revert old behavior.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235 */
Eric W. Biedermane1fc3b12012-08-07 07:29:57 +0000236 if (net->sctp.addip_noauth)
Vlad Yasevich73d9c4f2007-10-24 17:24:26 -0400237 asoc->peer.asconf_capable = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238
239 /* Create an input queue. */
240 sctp_inq_init(&asoc->base.inqueue);
David Howellsc4028952006-11-22 14:57:56 +0000241 sctp_inq_set_th_handler(&asoc->base.inqueue, sctp_assoc_bh_rcv);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242
243 /* Create an output queue. */
244 sctp_outq_init(asoc, &asoc->outqueue);
245
246 if (!sctp_ulpq_init(&asoc->ulpq, asoc))
247 goto fail_init;
248
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249 /* Assume that peer would support both address types unless we are
250 * told otherwise.
251 */
252 asoc->peer.ipv4_address = 1;
Wei Yongjuna2c39582009-04-07 16:35:11 +0800253 if (asoc->base.sk->sk_family == PF_INET6)
254 asoc->peer.ipv6_address = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255 INIT_LIST_HEAD(&asoc->asocs);
256
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257 asoc->default_stream = sp->default_stream;
258 asoc->default_ppid = sp->default_ppid;
259 asoc->default_flags = sp->default_flags;
260 asoc->default_context = sp->default_context;
261 asoc->default_timetolive = sp->default_timetolive;
Ivan Skytte Jorgensen6ab792f2006-12-13 16:34:22 -0800262 asoc->default_rcv_context = sp->default_rcv_context;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263
Vlad Yasevicha29a5bd2007-09-16 19:31:35 -0700264 /* AUTH related initializations */
265 INIT_LIST_HEAD(&asoc->endpoint_shared_keys);
266 err = sctp_auth_asoc_copy_shkeys(ep, asoc, gfp);
267 if (err)
268 goto fail_init;
269
270 asoc->active_key_id = ep->active_key_id;
Vlad Yasevicha29a5bd2007-09-16 19:31:35 -0700271
Vlad Yasevicha29a5bd2007-09-16 19:31:35 -0700272 /* Save the hmacs and chunks list into this association */
273 if (ep->auth_hmacs_list)
274 memcpy(asoc->c.auth_hmacs, ep->auth_hmacs_list,
275 ntohs(ep->auth_hmacs_list->param_hdr.length));
276 if (ep->auth_chunk_list)
277 memcpy(asoc->c.auth_chunks, ep->auth_chunk_list,
278 ntohs(ep->auth_chunk_list->param_hdr.length));
279
280 /* Get the AUTH random number for this association */
281 p = (sctp_paramhdr_t *)asoc->c.auth_random;
282 p->type = SCTP_PARAM_RANDOM;
283 p->length = htons(sizeof(sctp_paramhdr_t) + SCTP_AUTH_RANDOM_LENGTH);
284 get_random_bytes(p+1, SCTP_AUTH_RANDOM_LENGTH);
285
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286 return asoc;
287
288fail_init:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289 sock_put(asoc->base.sk);
Daniel Borkmann2e0c9e72013-06-14 18:24:07 +0200290 sctp_endpoint_put(asoc->ep);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291 return NULL;
292}
293
294/* Allocate and initialize a new association */
295struct sctp_association *sctp_association_new(const struct sctp_endpoint *ep,
296 const struct sock *sk,
Alexey Dobriyan3182cd82005-07-11 20:57:47 -0700297 sctp_scope_t scope,
Al Virodd0fc662005-10-07 07:46:04 +0100298 gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299{
300 struct sctp_association *asoc;
301
Daniel Borkmann939cfa72013-06-17 11:40:04 +0200302 asoc = kzalloc(sizeof(*asoc), gfp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303 if (!asoc)
304 goto fail;
305
306 if (!sctp_association_init(asoc, ep, sk, scope, gfp))
307 goto fail_init;
308
Linus Torvalds1da177e2005-04-16 15:20:36 -0700309 SCTP_DBG_OBJCNT_INC(assoc);
Daniel Borkmannbb333812013-06-28 19:49:40 +0200310
311 pr_debug("Created asoc %p\n", asoc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312
313 return asoc;
314
315fail_init:
316 kfree(asoc);
317fail:
318 return NULL;
319}
320
321/* Free this association if possible. There may still be users, so
322 * the actual deallocation may be delayed.
323 */
324void sctp_association_free(struct sctp_association *asoc)
325{
326 struct sock *sk = asoc->base.sk;
327 struct sctp_transport *transport;
328 struct list_head *pos, *temp;
329 int i;
330
Vlad Yasevichde76e692006-10-30 18:55:11 -0800331 /* Only real associations count against the endpoint, so
332 * don't bother for if this is a temporary association.
333 */
Xufeng Zhangd3217b12014-06-12 10:53:36 +0800334 if (!list_empty(&asoc->asocs)) {
Vlad Yasevichde76e692006-10-30 18:55:11 -0800335 list_del(&asoc->asocs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336
Vlad Yasevichde76e692006-10-30 18:55:11 -0800337 /* Decrement the backlog value for a TCP-style listening
338 * socket.
339 */
340 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
341 sk->sk_ack_backlog--;
342 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343
344 /* Mark as dead, so other users can know this structure is
345 * going away.
346 */
Daniel Borkmann0022d2d2013-04-15 03:27:18 +0000347 asoc->base.dead = true;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348
349 /* Dispose of any data lying around in the outqueue. */
350 sctp_outq_free(&asoc->outqueue);
351
352 /* Dispose of any pending messages for the upper layer. */
353 sctp_ulpq_free(&asoc->ulpq);
354
355 /* Dispose of any pending chunks on the inqueue. */
356 sctp_inq_free(&asoc->base.inqueue);
357
Vlad Yasevich8e1ee182008-10-08 14:18:39 -0700358 sctp_tsnmap_free(&asoc->peer.tsn_map);
359
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360 /* Free ssnmap storage. */
361 sctp_ssnmap_free(asoc->ssnmap);
362
363 /* Clean up the bound address list. */
364 sctp_bind_addr_free(&asoc->base.bind_addr);
365
366 /* Do we need to go through all of our timers and
367 * delete them? To be safe we will try to delete all, but we
368 * should be able to go through and make a guess based
369 * on our state.
370 */
371 for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i) {
Ying Xue25cc4ae2013-02-03 20:32:57 +0000372 if (del_timer(&asoc->timers[i]))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373 sctp_association_put(asoc);
374 }
375
376 /* Free peer's cached cookie. */
Jesper Juhla51482b2005-11-08 09:41:34 -0800377 kfree(asoc->peer.cookie);
Vlad Yasevich730fc3d2007-09-16 19:32:11 -0700378 kfree(asoc->peer.peer_random);
379 kfree(asoc->peer.peer_chunks);
380 kfree(asoc->peer.peer_hmacs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381
382 /* Release the transport structures. */
383 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
384 transport = list_entry(pos, struct sctp_transport, transports);
Thomas Graf45122ca262012-12-06 09:25:05 +0000385 list_del_rcu(pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386 sctp_transport_free(transport);
387 }
388
Frank Filz3f7a87d2005-06-20 13:14:57 -0700389 asoc->peer.transport_count = 0;
390
Wei Yongjuna000c012011-05-29 23:23:36 +0000391 sctp_asconf_queue_teardown(asoc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392
Michio Honda8a07eb02011-04-26 20:19:36 +0900393 /* Free pending address space being deleted */
394 if (asoc->asconf_addr_del_pending != NULL)
395 kfree(asoc->asconf_addr_del_pending);
396
Vlad Yasevicha29a5bd2007-09-16 19:31:35 -0700397 /* AUTH - Free the endpoint shared keys */
398 sctp_auth_destroy_keys(&asoc->endpoint_shared_keys);
399
400 /* AUTH - Free the association shared key */
401 sctp_auth_key_put(asoc->asoc_shared_key);
402
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403 sctp_association_put(asoc);
404}
405
406/* Cleanup and free up an association. */
407static void sctp_association_destroy(struct sctp_association *asoc)
408{
Daniel Borkmannbb333812013-06-28 19:49:40 +0200409 if (unlikely(!asoc->base.dead)) {
410 WARN(1, "Attempt to destroy undead association %p!\n", asoc);
411 return;
412 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700413
414 sctp_endpoint_put(asoc->ep);
415 sock_put(asoc->base.sk);
416
417 if (asoc->assoc_id != 0) {
418 spin_lock_bh(&sctp_assocs_id_lock);
419 idr_remove(&sctp_assocs_id, asoc->assoc_id);
420 spin_unlock_bh(&sctp_assocs_id_lock);
421 }
422
Ilpo Järvinen547b7922008-07-25 21:43:18 -0700423 WARN_ON(atomic_read(&asoc->rmem_alloc));
Neil Horman049b3ff2005-11-11 16:08:24 -0800424
Daniel Borkmannff2266c2013-04-15 03:27:17 +0000425 kfree(asoc);
426 SCTP_DBG_OBJCNT_DEC(assoc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427}
428
429/* Change the primary destination address for the peer. */
430void sctp_assoc_set_primary(struct sctp_association *asoc,
431 struct sctp_transport *transport)
432{
Vlad Yasevich319fa2a2008-06-16 17:00:29 -0700433 int changeover = 0;
434
435 /* it's a changeover only if we already have a primary path
436 * that we are changing
437 */
438 if (asoc->peer.primary_path != NULL &&
439 asoc->peer.primary_path != transport)
440 changeover = 1 ;
441
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442 asoc->peer.primary_path = transport;
443
444 /* Set a default msg_name for events. */
445 memcpy(&asoc->peer.primary_addr, &transport->ipaddr,
446 sizeof(union sctp_addr));
447
448 /* If the primary path is changing, assume that the
449 * user wants to use this new path.
450 */
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700451 if ((transport->state == SCTP_ACTIVE) ||
452 (transport->state == SCTP_UNKNOWN))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700453 asoc->peer.active_path = transport;
454
455 /*
456 * SFR-CACC algorithm:
457 * Upon the receipt of a request to change the primary
458 * destination address, on the data structure for the new
459 * primary destination, the sender MUST do the following:
460 *
461 * 1) If CHANGEOVER_ACTIVE is set, then there was a switch
462 * to this destination address earlier. The sender MUST set
463 * CYCLING_CHANGEOVER to indicate that this switch is a
464 * double switch to the same destination address.
Vlad Yaseviche0e9db12009-11-23 15:53:57 -0500465 *
466 * Really, only bother is we have data queued or outstanding on
467 * the association.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468 */
Vlad Yaseviche0e9db12009-11-23 15:53:57 -0500469 if (!asoc->outqueue.outstanding_bytes && !asoc->outqueue.out_qlen)
470 return;
471
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472 if (transport->cacc.changeover_active)
Vlad Yasevich319fa2a2008-06-16 17:00:29 -0700473 transport->cacc.cycling_changeover = changeover;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474
475 /* 2) The sender MUST set CHANGEOVER_ACTIVE to indicate that
476 * a changeover has occurred.
477 */
Vlad Yasevich319fa2a2008-06-16 17:00:29 -0700478 transport->cacc.changeover_active = changeover;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479
480 /* 3) The sender MUST store the next TSN to be sent in
481 * next_tsn_at_change.
482 */
483 transport->cacc.next_tsn_at_change = asoc->next_tsn;
484}
485
Frank Filz3f7a87d2005-06-20 13:14:57 -0700486/* Remove a transport from an association. */
487void sctp_assoc_rm_peer(struct sctp_association *asoc,
488 struct sctp_transport *peer)
489{
490 struct list_head *pos;
491 struct sctp_transport *transport;
492
Daniel Borkmannbb333812013-06-28 19:49:40 +0200493 pr_debug("%s: association:%p addr:%pISpc\n",
494 __func__, asoc, &peer->ipaddr.sa);
Frank Filz3f7a87d2005-06-20 13:14:57 -0700495
496 /* If we are to remove the current retran_path, update it
497 * to the next peer before removing this peer from the list.
498 */
499 if (asoc->peer.retran_path == peer)
500 sctp_assoc_update_retran_path(asoc);
501
502 /* Remove this peer from the list. */
Thomas Graf45122ca262012-12-06 09:25:05 +0000503 list_del_rcu(&peer->transports);
Frank Filz3f7a87d2005-06-20 13:14:57 -0700504
505 /* Get the first transport of asoc. */
506 pos = asoc->peer.transport_addr_list.next;
507 transport = list_entry(pos, struct sctp_transport, transports);
508
509 /* Update any entries that match the peer to be deleted. */
510 if (asoc->peer.primary_path == peer)
511 sctp_assoc_set_primary(asoc, transport);
512 if (asoc->peer.active_path == peer)
513 asoc->peer.active_path = transport;
Wei Yongjun9494c7c2011-04-12 15:22:22 +0000514 if (asoc->peer.retran_path == peer)
515 asoc->peer.retran_path = transport;
Frank Filz3f7a87d2005-06-20 13:14:57 -0700516 if (asoc->peer.last_data_from == peer)
517 asoc->peer.last_data_from = transport;
518
519 /* If we remove the transport an INIT was last sent to, set it to
520 * NULL. Combined with the update of the retran path above, this
521 * will cause the next INIT to be sent to the next available
522 * transport, maintaining the cycle.
523 */
524 if (asoc->init_last_sent_to == peer)
525 asoc->init_last_sent_to = NULL;
526
Wei Yongjun6345b192009-04-26 23:13:35 +0800527 /* If we remove the transport an SHUTDOWN was last sent to, set it
528 * to NULL. Combined with the update of the retran path above, this
529 * will cause the next SHUTDOWN to be sent to the next available
530 * transport, maintaining the cycle.
531 */
532 if (asoc->shutdown_last_sent_to == peer)
533 asoc->shutdown_last_sent_to = NULL;
534
Wei Yongjun10a43ce2009-04-26 23:14:42 +0800535 /* If we remove the transport an ASCONF was last sent to, set it to
536 * NULL.
537 */
538 if (asoc->addip_last_asconf &&
539 asoc->addip_last_asconf->transport == peer)
540 asoc->addip_last_asconf->transport = NULL;
541
Vlad Yasevich31b02e12009-09-04 18:21:00 -0400542 /* If we have something on the transmitted list, we have to
543 * save it off. The best place is the active path.
544 */
545 if (!list_empty(&peer->transmitted)) {
546 struct sctp_transport *active = asoc->peer.active_path;
547 struct sctp_chunk *ch;
548
549 /* Reset the transport of each chunk on this list */
550 list_for_each_entry(ch, &peer->transmitted,
551 transmitted_list) {
552 ch->transport = NULL;
553 ch->rtt_in_progress = 0;
554 }
555
556 list_splice_tail_init(&peer->transmitted,
557 &active->transmitted);
558
559 /* Start a T3 timer here in case it wasn't running so
560 * that these migrated packets have a chance to get
wangweidong2bccbad2013-10-26 16:06:30 +0800561 * retransmitted.
Vlad Yasevich31b02e12009-09-04 18:21:00 -0400562 */
563 if (!timer_pending(&active->T3_rtx_timer))
564 if (!mod_timer(&active->T3_rtx_timer,
565 jiffies + active->rto))
566 sctp_transport_hold(active);
567 }
568
Frank Filz3f7a87d2005-06-20 13:14:57 -0700569 asoc->peer.transport_count--;
570
571 sctp_transport_free(peer);
572}
573
Linus Torvalds1da177e2005-04-16 15:20:36 -0700574/* Add a transport address to an association. */
575struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc,
576 const union sctp_addr *addr,
Al Virodd0fc662005-10-07 07:46:04 +0100577 const gfp_t gfp,
Frank Filz3f7a87d2005-06-20 13:14:57 -0700578 const int peer_state)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579{
Eric W. Biederman89bf3452012-08-07 07:26:14 +0000580 struct net *net = sock_net(asoc->base.sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700581 struct sctp_transport *peer;
582 struct sctp_sock *sp;
583 unsigned short port;
584
585 sp = sctp_sk(asoc->base.sk);
586
587 /* AF_INET and AF_INET6 share common port field. */
Al Viro4bdf4b52006-11-20 17:10:20 -0800588 port = ntohs(addr->v4.sin_port);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700589
Daniel Borkmannbb333812013-06-28 19:49:40 +0200590 pr_debug("%s: association:%p addr:%pISpc state:%d\n", __func__,
591 asoc, &addr->sa, peer_state);
Frank Filz3f7a87d2005-06-20 13:14:57 -0700592
Linus Torvalds1da177e2005-04-16 15:20:36 -0700593 /* Set the port if it has not been set yet. */
594 if (0 == asoc->peer.port)
595 asoc->peer.port = port;
596
597 /* Check to see if this is a duplicate. */
598 peer = sctp_assoc_lookup_paddr(asoc, addr);
Frank Filz3f7a87d2005-06-20 13:14:57 -0700599 if (peer) {
Vlad Yasevichadd52372008-09-18 16:28:27 -0700600 /* An UNKNOWN state is only set on transports added by
601 * user in sctp_connectx() call. Such transports should be
602 * considered CONFIRMED per RFC 4960, Section 5.4.
603 */
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700604 if (peer->state == SCTP_UNKNOWN) {
Vlad Yasevichadd52372008-09-18 16:28:27 -0700605 peer->state = SCTP_ACTIVE;
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700606 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607 return peer;
Frank Filz3f7a87d2005-06-20 13:14:57 -0700608 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609
Eric W. Biederman89bf3452012-08-07 07:26:14 +0000610 peer = sctp_transport_new(net, addr, gfp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611 if (!peer)
612 return NULL;
613
614 sctp_transport_set_owner(peer, asoc);
615
Frank Filz52ccb8e2005-12-22 11:36:46 -0800616 /* Initialize the peer's heartbeat interval based on the
617 * association configured value.
618 */
619 peer->hbinterval = asoc->hbinterval;
620
621 /* Set the path max_retrans. */
622 peer->pathmaxrxt = asoc->pathmaxrxt;
623
wangweidong2bccbad2013-10-26 16:06:30 +0800624 /* And the partial failure retrans threshold */
Neil Horman5aa93bc2012-07-21 07:56:07 +0000625 peer->pf_retrans = asoc->pf_retrans;
626
Frank Filz52ccb8e2005-12-22 11:36:46 -0800627 /* Initialize the peer's SACK delay timeout based on the
628 * association configured value.
629 */
630 peer->sackdelay = asoc->sackdelay;
Wei Yongjund364d922008-05-09 15:13:26 -0700631 peer->sackfreq = asoc->sackfreq;
Frank Filz52ccb8e2005-12-22 11:36:46 -0800632
633 /* Enable/disable heartbeat, SACK delay, and path MTU discovery
634 * based on association setting.
635 */
636 peer->param_flags = asoc->param_flags;
637
Vlad Yasevich8da645e2009-09-04 18:21:01 -0400638 sctp_transport_route(peer, NULL, sp);
639
Linus Torvalds1da177e2005-04-16 15:20:36 -0700640 /* Initialize the pmtu of the transport. */
Vlad Yasevich8da645e2009-09-04 18:21:01 -0400641 if (peer->param_flags & SPP_PMTUD_DISABLE) {
642 if (asoc->pathmtu)
643 peer->pathmtu = asoc->pathmtu;
644 else
645 peer->pathmtu = SCTP_DEFAULT_MAXSEGMENT;
646 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647
648 /* If this is the first transport addr on this association,
649 * initialize the association PMTU to the peer's PMTU.
650 * If not and the current association PMTU is higher than the new
651 * peer's PMTU, reset the association PMTU to the new peer's PMTU.
652 */
Frank Filz52ccb8e2005-12-22 11:36:46 -0800653 if (asoc->pathmtu)
654 asoc->pathmtu = min_t(int, peer->pathmtu, asoc->pathmtu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700655 else
Frank Filz52ccb8e2005-12-22 11:36:46 -0800656 asoc->pathmtu = peer->pathmtu;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657
Daniel Borkmannbb333812013-06-28 19:49:40 +0200658 pr_debug("%s: association:%p PMTU set to %d\n", __func__, asoc,
659 asoc->pathmtu);
660
Florian Westphal6d0ccba2008-07-18 23:04:39 -0700661 peer->pmtu_pending = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700662
Vlad Yasevichf68b2e02009-09-04 18:21:00 -0400663 asoc->frag_point = sctp_frag_point(asoc, asoc->pathmtu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700664
665 /* The asoc->peer.port might not be meaningful yet, but
666 * initialize the packet structure anyway.
667 */
668 sctp_packet_init(&peer->packet, peer, asoc->base.bind_addr.port,
669 asoc->peer.port);
670
671 /* 7.2.1 Slow-Start
672 *
673 * o The initial cwnd before DATA transmission or after a sufficiently
674 * long idle period MUST be set to
675 * min(4*MTU, max(2*MTU, 4380 bytes))
676 *
677 * o The initial value of ssthresh MAY be arbitrarily high
678 * (for example, implementations MAY use the size of the
679 * receiver advertised window).
680 */
Frank Filz52ccb8e2005-12-22 11:36:46 -0800681 peer->cwnd = min(4*asoc->pathmtu, max_t(__u32, 2*asoc->pathmtu, 4380));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700682
683 /* At this point, we may not have the receiver's advertised window,
684 * so initialize ssthresh to the default value and it will be set
685 * later when we process the INIT.
686 */
687 peer->ssthresh = SCTP_DEFAULT_MAXWINDOW;
688
689 peer->partial_bytes_acked = 0;
690 peer->flight_size = 0;
Vlad Yasevich46d5a802009-11-23 15:54:00 -0500691 peer->burst_limited = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700692
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693 /* Set the transport's RTO.initial value */
694 peer->rto = asoc->rto_initial;
Michele Baldessari196d6752012-12-01 04:49:42 +0000695 sctp_max_rto(asoc, peer);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700696
Frank Filz3f7a87d2005-06-20 13:14:57 -0700697 /* Set the peer's active state. */
698 peer->state = peer_state;
699
Linus Torvalds1da177e2005-04-16 15:20:36 -0700700 /* Attach the remote transport to our asoc. */
Thomas Graf45122ca262012-12-06 09:25:05 +0000701 list_add_tail_rcu(&peer->transports, &asoc->peer.transport_addr_list);
Frank Filz3f7a87d2005-06-20 13:14:57 -0700702 asoc->peer.transport_count++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703
704 /* If we do not yet have a primary path, set one. */
705 if (!asoc->peer.primary_path) {
706 sctp_assoc_set_primary(asoc, peer);
707 asoc->peer.retran_path = peer;
708 }
709
Vlad Yasevichfbdf5012010-04-30 22:39:26 -0400710 if (asoc->peer.active_path == asoc->peer.retran_path &&
711 peer->state != SCTP_UNCONFIRMED) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712 asoc->peer.retran_path = peer;
Frank Filz3f7a87d2005-06-20 13:14:57 -0700713 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714
715 return peer;
716}
717
718/* Delete a transport address from an association. */
719void sctp_assoc_del_peer(struct sctp_association *asoc,
720 const union sctp_addr *addr)
721{
722 struct list_head *pos;
723 struct list_head *temp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700724 struct sctp_transport *transport;
725
726 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
727 transport = list_entry(pos, struct sctp_transport, transports);
728 if (sctp_cmp_addr_exact(addr, &transport->ipaddr)) {
Frank Filz3f7a87d2005-06-20 13:14:57 -0700729 /* Do book keeping for removing the peer and free it. */
730 sctp_assoc_rm_peer(asoc, transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731 break;
732 }
733 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700734}
735
736/* Lookup a transport by address. */
737struct sctp_transport *sctp_assoc_lookup_paddr(
738 const struct sctp_association *asoc,
739 const union sctp_addr *address)
740{
741 struct sctp_transport *t;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700742
743 /* Cycle through all transports searching for a peer address. */
744
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -0700745 list_for_each_entry(t, &asoc->peer.transport_addr_list,
746 transports) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700747 if (sctp_cmp_addr_exact(address, &t->ipaddr))
748 return t;
749 }
750
751 return NULL;
752}
753
Vlad Yasevich42e30bf2007-12-20 14:08:56 -0800754/* Remove all transports except a give one */
755void sctp_assoc_del_nonprimary_peers(struct sctp_association *asoc,
756 struct sctp_transport *primary)
757{
758 struct sctp_transport *temp;
759 struct sctp_transport *t;
760
761 list_for_each_entry_safe(t, temp, &asoc->peer.transport_addr_list,
762 transports) {
763 /* if the current transport is not the primary one, delete it */
764 if (t != primary)
765 sctp_assoc_rm_peer(asoc, t);
766 }
Vlad Yasevich42e30bf2007-12-20 14:08:56 -0800767}
768
Linus Torvalds1da177e2005-04-16 15:20:36 -0700769/* Engage in transport control operations.
770 * Mark the transport up or down and send a notification to the user.
771 * Select and update the new active and retran paths.
772 */
773void sctp_assoc_control_transport(struct sctp_association *asoc,
774 struct sctp_transport *transport,
775 sctp_transport_cmd_t command,
776 sctp_sn_error_t error)
777{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700778 struct sctp_ulpevent *event;
Al Viro0906e202006-11-20 17:03:01 -0800779 struct sockaddr_storage addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700780 int spc_state = 0;
Neil Horman5aa93bc2012-07-21 07:56:07 +0000781 bool ulp_notify = true;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700782
783 /* Record the transition on the transport. */
784 switch (command) {
785 case SCTP_TRANSPORT_UP:
Vlad Yasevich1ae4114d2007-03-23 11:32:26 -0700786 /* If we are moving from UNCONFIRMED state due
787 * to heartbeat success, report the SCTP_ADDR_CONFIRMED
788 * state to the user, otherwise report SCTP_ADDR_AVAILABLE.
789 */
790 if (SCTP_UNCONFIRMED == transport->state &&
791 SCTP_HEARTBEAT_SUCCESS == error)
792 spc_state = SCTP_ADDR_CONFIRMED;
793 else
794 spc_state = SCTP_ADDR_AVAILABLE;
Neil Horman5aa93bc2012-07-21 07:56:07 +0000795 /* Don't inform ULP about transition from PF to
Daniel Borkmannac4f9592013-08-09 15:09:08 +0200796 * active state and set cwnd to 1 MTU, see SCTP
Neil Horman5aa93bc2012-07-21 07:56:07 +0000797 * Quick failover draft section 5.1, point 5
798 */
799 if (transport->state == SCTP_PF) {
800 ulp_notify = false;
Daniel Borkmannac4f9592013-08-09 15:09:08 +0200801 transport->cwnd = asoc->pathmtu;
Neil Horman5aa93bc2012-07-21 07:56:07 +0000802 }
Frank Filz3f7a87d2005-06-20 13:14:57 -0700803 transport->state = SCTP_ACTIVE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700804 break;
805
806 case SCTP_TRANSPORT_DOWN:
Vlad Yasevich40187882009-06-23 11:28:05 -0400807 /* If the transport was never confirmed, do not transition it
808 * to inactive state. Also, release the cached route since
809 * there may be a better route next time.
Vlad Yasevichcc756892007-08-24 19:30:25 +0900810 */
811 if (transport->state != SCTP_UNCONFIRMED)
812 transport->state = SCTP_INACTIVE;
Vlad Yasevich40187882009-06-23 11:28:05 -0400813 else {
814 dst_release(transport->dst);
815 transport->dst = NULL;
zhuyj061079a2014-08-20 17:31:43 +0800816 ulp_notify = false;
Vlad Yasevich40187882009-06-23 11:28:05 -0400817 }
Vlad Yasevichcc756892007-08-24 19:30:25 +0900818
Linus Torvalds1da177e2005-04-16 15:20:36 -0700819 spc_state = SCTP_ADDR_UNREACHABLE;
820 break;
821
Neil Horman5aa93bc2012-07-21 07:56:07 +0000822 case SCTP_TRANSPORT_PF:
823 transport->state = SCTP_PF;
824 ulp_notify = false;
825 break;
826
Linus Torvalds1da177e2005-04-16 15:20:36 -0700827 default:
828 return;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700829 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700830
Daniel Borkmannb82e8f32014-06-11 18:19:29 +0200831 /* Generate and send a SCTP_PEER_ADDR_CHANGE notification
832 * to the user.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700833 */
Neil Horman5aa93bc2012-07-21 07:56:07 +0000834 if (ulp_notify) {
835 memset(&addr, 0, sizeof(struct sockaddr_storage));
836 memcpy(&addr, &transport->ipaddr,
837 transport->af_specific->sockaddr_len);
Daniel Borkmannb82e8f32014-06-11 18:19:29 +0200838
Neil Horman5aa93bc2012-07-21 07:56:07 +0000839 event = sctp_ulpevent_make_peer_addr_change(asoc, &addr,
840 0, spc_state, error, GFP_ATOMIC);
841 if (event)
842 sctp_ulpq_tail_event(&asoc->ulpq, event);
843 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700844
845 /* Select new active and retran paths. */
Daniel Borkmannb82e8f32014-06-11 18:19:29 +0200846 sctp_select_active_and_retran_path(asoc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700847}
848
849/* Hold a reference to an association. */
850void sctp_association_hold(struct sctp_association *asoc)
851{
852 atomic_inc(&asoc->base.refcnt);
853}
854
855/* Release a reference to an association and cleanup
856 * if there are no more references.
857 */
858void sctp_association_put(struct sctp_association *asoc)
859{
860 if (atomic_dec_and_test(&asoc->base.refcnt))
861 sctp_association_destroy(asoc);
862}
863
864/* Allocate the next TSN, Transmission Sequence Number, for the given
865 * association.
866 */
867__u32 sctp_association_get_next_tsn(struct sctp_association *asoc)
868{
869 /* From Section 1.6 Serial Number Arithmetic:
870 * Transmission Sequence Numbers wrap around when they reach
871 * 2**32 - 1. That is, the next TSN a DATA chunk MUST use
872 * after transmitting TSN = 2*32 - 1 is TSN = 0.
873 */
874 __u32 retval = asoc->next_tsn;
875 asoc->next_tsn++;
876 asoc->unack_data++;
877
878 return retval;
879}
880
881/* Compare two addresses to see if they match. Wildcard addresses
882 * only match themselves.
883 */
884int sctp_cmp_addr_exact(const union sctp_addr *ss1,
885 const union sctp_addr *ss2)
886{
887 struct sctp_af *af;
888
889 af = sctp_get_af_specific(ss1->sa.sa_family);
890 if (unlikely(!af))
891 return 0;
892
893 return af->cmp_addr(ss1, ss2);
894}
895
896/* Return an ecne chunk to get prepended to a packet.
897 * Note: We are sly and return a shared, prealloced chunk. FIXME:
898 * No we don't, but we could/should.
899 */
900struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc)
901{
wangweidong8b7318d2013-12-06 09:36:28 +0800902 if (!asoc->need_ecne)
903 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700904
905 /* Send ECNE if needed.
906 * Not being able to allocate a chunk here is not deadly.
907 */
wangweidong8b7318d2013-12-06 09:36:28 +0800908 return sctp_make_ecne(asoc, asoc->last_ecne_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700909}
910
911/*
912 * Find which transport this TSN was sent on.
913 */
914struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *asoc,
915 __u32 tsn)
916{
917 struct sctp_transport *active;
918 struct sctp_transport *match;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700919 struct sctp_transport *transport;
920 struct sctp_chunk *chunk;
Al Virodbc16db2006-11-20 17:01:42 -0800921 __be32 key = htonl(tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700922
923 match = NULL;
924
925 /*
926 * FIXME: In general, find a more efficient data structure for
927 * searching.
928 */
929
930 /*
931 * The general strategy is to search each transport's transmitted
932 * list. Return which transport this TSN lives on.
933 *
934 * Let's be hopeful and check the active_path first.
935 * Another optimization would be to know if there is only one
936 * outbound path and not have to look for the TSN at all.
937 *
938 */
939
940 active = asoc->peer.active_path;
941
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -0700942 list_for_each_entry(chunk, &active->transmitted,
943 transmitted_list) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700944
945 if (key == chunk->subh.data_hdr->tsn) {
946 match = active;
947 goto out;
948 }
949 }
950
951 /* If not found, go search all the other transports. */
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -0700952 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
953 transports) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700954
955 if (transport == active)
Xufeng Zhang2317f442013-03-07 21:39:37 +0000956 continue;
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -0700957 list_for_each_entry(chunk, &transport->transmitted,
958 transmitted_list) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700959 if (key == chunk->subh.data_hdr->tsn) {
960 match = transport;
961 goto out;
962 }
963 }
964 }
965out:
966 return match;
967}
968
969/* Is this the association we are looking for? */
970struct sctp_transport *sctp_assoc_is_match(struct sctp_association *asoc,
Eric W. Biederman4110cc22012-08-06 08:41:13 +0000971 struct net *net,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700972 const union sctp_addr *laddr,
973 const union sctp_addr *paddr)
974{
975 struct sctp_transport *transport;
976
Al Viroe2fcced2006-11-20 17:08:41 -0800977 if ((htons(asoc->base.bind_addr.port) == laddr->v4.sin_port) &&
Eric W. Biederman4110cc22012-08-06 08:41:13 +0000978 (htons(asoc->peer.port) == paddr->v4.sin_port) &&
979 net_eq(sock_net(asoc->base.sk), net)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700980 transport = sctp_assoc_lookup_paddr(asoc, paddr);
981 if (!transport)
982 goto out;
983
984 if (sctp_bind_addr_match(&asoc->base.bind_addr, laddr,
985 sctp_sk(asoc->base.sk)))
986 goto out;
987 }
988 transport = NULL;
989
990out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700991 return transport;
992}
993
994/* Do delayed input processing. This is scheduled by sctp_rcv(). */
David Howellsc4028952006-11-22 14:57:56 +0000995static void sctp_assoc_bh_rcv(struct work_struct *work)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700996{
David Howellsc4028952006-11-22 14:57:56 +0000997 struct sctp_association *asoc =
998 container_of(work, struct sctp_association,
999 base.inqueue.immediate);
Eric W. Biederman55e26eb2012-08-07 07:25:24 +00001000 struct net *net = sock_net(asoc->base.sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001001 struct sctp_endpoint *ep;
1002 struct sctp_chunk *chunk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001003 struct sctp_inq *inqueue;
1004 int state;
1005 sctp_subtype_t subtype;
1006 int error = 0;
1007
1008 /* The association should be held so we should be safe. */
1009 ep = asoc->ep;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001010
1011 inqueue = &asoc->base.inqueue;
1012 sctp_association_hold(asoc);
1013 while (NULL != (chunk = sctp_inq_pop(inqueue))) {
1014 state = asoc->state;
1015 subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type);
1016
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07001017 /* SCTP-AUTH, Section 6.3:
1018 * The receiver has a list of chunk types which it expects
1019 * to be received only after an AUTH-chunk. This list has
1020 * been sent to the peer during the association setup. It
1021 * MUST silently discard these chunks if they are not placed
1022 * after an AUTH chunk in the packet.
1023 */
1024 if (sctp_auth_recv_cid(subtype.chunk, asoc) && !chunk->auth)
1025 continue;
1026
Linus Torvalds1da177e2005-04-16 15:20:36 -07001027 /* Remember where the last DATA chunk came from so we
1028 * know where to send the SACK.
1029 */
1030 if (sctp_chunk_is_data(chunk))
1031 asoc->peer.last_data_from = chunk->transport;
Michele Baldessari196d6752012-12-01 04:49:42 +00001032 else {
Eric W. Biederman55e26eb2012-08-07 07:25:24 +00001033 SCTP_INC_STATS(net, SCTP_MIB_INCTRLCHUNKS);
Michele Baldessari196d6752012-12-01 04:49:42 +00001034 asoc->stats.ictrlchunks++;
1035 if (chunk->chunk_hdr->type == SCTP_CID_SACK)
1036 asoc->stats.isacks++;
1037 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001038
1039 if (chunk->transport)
Daniel Borkmanne575235f2014-06-11 18:19:30 +02001040 chunk->transport->last_time_heard = ktime_get();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001041
1042 /* Run through the state machine. */
Eric W. Biederman55e26eb2012-08-07 07:25:24 +00001043 error = sctp_do_sm(net, SCTP_EVENT_T_CHUNK, subtype,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001044 state, ep, asoc, chunk, GFP_ATOMIC);
1045
1046 /* Check to see if the association is freed in response to
1047 * the incoming chunk. If so, get out of the while loop.
1048 */
1049 if (asoc->base.dead)
1050 break;
1051
1052 /* If there is an error on chunk, discard this packet. */
1053 if (error && chunk)
1054 chunk->pdiscard = 1;
1055 }
1056 sctp_association_put(asoc);
1057}
1058
1059/* This routine moves an association from its old sk to a new sk. */
1060void sctp_assoc_migrate(struct sctp_association *assoc, struct sock *newsk)
1061{
1062 struct sctp_sock *newsp = sctp_sk(newsk);
1063 struct sock *oldsk = assoc->base.sk;
1064
1065 /* Delete the association from the old endpoint's list of
1066 * associations.
1067 */
1068 list_del_init(&assoc->asocs);
1069
1070 /* Decrement the backlog value for a TCP-style socket. */
1071 if (sctp_style(oldsk, TCP))
1072 oldsk->sk_ack_backlog--;
1073
1074 /* Release references to the old endpoint and the sock. */
1075 sctp_endpoint_put(assoc->ep);
1076 sock_put(assoc->base.sk);
1077
1078 /* Get a reference to the new endpoint. */
1079 assoc->ep = newsp->ep;
1080 sctp_endpoint_hold(assoc->ep);
1081
1082 /* Get a reference to the new sock. */
1083 assoc->base.sk = newsk;
1084 sock_hold(assoc->base.sk);
1085
1086 /* Add the association to the new endpoint's list of associations. */
1087 sctp_endpoint_add_asoc(newsp->ep, assoc);
1088}
1089
1090/* Update an association (possibly from unexpected COOKIE-ECHO processing). */
1091void sctp_assoc_update(struct sctp_association *asoc,
1092 struct sctp_association *new)
1093{
1094 struct sctp_transport *trans;
1095 struct list_head *pos, *temp;
1096
1097 /* Copy in new parameters of peer. */
1098 asoc->c = new->c;
1099 asoc->peer.rwnd = new->peer.rwnd;
1100 asoc->peer.sack_needed = new->peer.sack_needed;
Daniel Borkmann1be9a952014-07-22 15:22:45 +02001101 asoc->peer.auth_capable = new->peer.auth_capable;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001102 asoc->peer.i = new->peer.i;
Vlad Yasevich8e1ee182008-10-08 14:18:39 -07001103 sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
1104 asoc->peer.i.initial_tsn, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001105
1106 /* Remove any peer addresses not present in the new association. */
1107 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
1108 trans = list_entry(pos, struct sctp_transport, transports);
Vlad Yasevich0c427492010-04-28 08:47:19 +00001109 if (!sctp_assoc_lookup_paddr(new, &trans->ipaddr)) {
1110 sctp_assoc_rm_peer(asoc, trans);
1111 continue;
1112 }
Vlad Yasevich749bf922007-03-19 17:02:30 -07001113
1114 if (asoc->state >= SCTP_STATE_ESTABLISHED)
1115 sctp_transport_reset(trans);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001116 }
1117
1118 /* If the case is A (association restart), use
1119 * initial_tsn as next_tsn. If the case is B, use
1120 * current next_tsn in case data sent to peer
1121 * has been discarded and needs retransmission.
1122 */
1123 if (asoc->state >= SCTP_STATE_ESTABLISHED) {
1124 asoc->next_tsn = new->next_tsn;
1125 asoc->ctsn_ack_point = new->ctsn_ack_point;
1126 asoc->adv_peer_ack_point = new->adv_peer_ack_point;
1127
1128 /* Reinitialize SSN for both local streams
1129 * and peer's streams.
1130 */
1131 sctp_ssnmap_clear(asoc->ssnmap);
1132
Vlad Yasevich0b58a812007-03-19 17:01:17 -07001133 /* Flush the ULP reassembly and ordered queue.
1134 * Any data there will now be stale and will
1135 * cause problems.
1136 */
1137 sctp_ulpq_flush(&asoc->ulpq);
1138
Vlad Yasevich749bf922007-03-19 17:02:30 -07001139 /* reset the overall association error count so
1140 * that the restarted association doesn't get torn
1141 * down on the next retransmission timer.
1142 */
1143 asoc->overall_error_count = 0;
1144
Linus Torvalds1da177e2005-04-16 15:20:36 -07001145 } else {
1146 /* Add any peer addresses from the new association. */
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -07001147 list_for_each_entry(trans, &new->peer.transport_addr_list,
1148 transports) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001149 if (!sctp_assoc_lookup_paddr(asoc, &trans->ipaddr))
1150 sctp_assoc_add_peer(asoc, &trans->ipaddr,
Sridhar Samudralaad8fec12006-07-21 14:48:50 -07001151 GFP_ATOMIC, trans->state);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001152 }
1153
1154 asoc->ctsn_ack_point = asoc->next_tsn - 1;
1155 asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
1156 if (!asoc->ssnmap) {
1157 /* Move the ssnmap. */
1158 asoc->ssnmap = new->ssnmap;
1159 new->ssnmap = NULL;
1160 }
Vlad Yasevich07d93962007-05-04 13:55:27 -07001161
1162 if (!asoc->assoc_id) {
1163 /* get a new association id since we don't have one
1164 * yet.
1165 */
1166 sctp_assoc_set_id(asoc, GFP_ATOMIC);
1167 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001168 }
Vlad Yasevicha29a5bd2007-09-16 19:31:35 -07001169
wangweidong9d2c8812013-12-06 09:36:30 +08001170 /* SCTP-AUTH: Save the peer parameters from the new associations
Vlad Yasevich730fc3d2007-09-16 19:32:11 -07001171 * and also move the association shared keys over
1172 */
1173 kfree(asoc->peer.peer_random);
1174 asoc->peer.peer_random = new->peer.peer_random;
1175 new->peer.peer_random = NULL;
1176
1177 kfree(asoc->peer.peer_chunks);
1178 asoc->peer.peer_chunks = new->peer.peer_chunks;
1179 new->peer.peer_chunks = NULL;
1180
1181 kfree(asoc->peer.peer_hmacs);
1182 asoc->peer.peer_hmacs = new->peer.peer_hmacs;
1183 new->peer.peer_hmacs = NULL;
1184
1185 sctp_auth_key_put(asoc->asoc_shared_key);
1186 sctp_auth_asoc_init_active_key(asoc, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001187}
1188
1189/* Update the retran path for sending a retransmitted packet.
Daniel Borkmann4c47af42014-02-20 20:51:06 +01001190 * See also RFC4960, 6.4. Multi-Homed SCTP Endpoints:
1191 *
1192 * When there is outbound data to send and the primary path
1193 * becomes inactive (e.g., due to failures), or where the
1194 * SCTP user explicitly requests to send data to an
1195 * inactive destination transport address, before reporting
1196 * an error to its ULP, the SCTP endpoint should try to send
1197 * the data to an alternate active destination transport
1198 * address if one exists.
1199 *
1200 * When retransmitting data that timed out, if the endpoint
1201 * is multihomed, it should consider each source-destination
1202 * address pair in its retransmission selection policy.
1203 * When retransmitting timed-out data, the endpoint should
1204 * attempt to pick the most divergent source-destination
1205 * pair from the original source-destination pair to which
1206 * the packet was transmitted.
1207 *
1208 * Note: Rules for picking the most divergent source-destination
1209 * pair are an implementation decision and are not specified
1210 * within this document.
1211 *
1212 * Our basic strategy is to round-robin transports in priorities
1213 * according to sctp_state_prio_map[] e.g., if no such
1214 * transport with state SCTP_ACTIVE exists, round-robin through
1215 * SCTP_UNKNOWN, etc. You get the picture.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001216 */
Daniel Borkmann4c47af42014-02-20 20:51:06 +01001217static const u8 sctp_trans_state_to_prio_map[] = {
1218 [SCTP_ACTIVE] = 3, /* best case */
1219 [SCTP_UNKNOWN] = 2,
1220 [SCTP_PF] = 1,
1221 [SCTP_INACTIVE] = 0, /* worst case */
1222};
1223
1224static u8 sctp_trans_score(const struct sctp_transport *trans)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001225{
Daniel Borkmann4c47af42014-02-20 20:51:06 +01001226 return sctp_trans_state_to_prio_map[trans->state];
Frank Filz3f7a87d2005-06-20 13:14:57 -07001227}
1228
Daniel Borkmanna7288c42014-06-11 18:19:31 +02001229static struct sctp_transport *sctp_trans_elect_tie(struct sctp_transport *trans1,
1230 struct sctp_transport *trans2)
1231{
1232 if (trans1->error_count > trans2->error_count) {
1233 return trans2;
1234 } else if (trans1->error_count == trans2->error_count &&
1235 ktime_after(trans2->last_time_heard,
1236 trans1->last_time_heard)) {
1237 return trans2;
1238 } else {
1239 return trans1;
1240 }
1241}
1242
Daniel Borkmann4c47af42014-02-20 20:51:06 +01001243static struct sctp_transport *sctp_trans_elect_best(struct sctp_transport *curr,
1244 struct sctp_transport *best)
1245{
Daniel Borkmanna7288c42014-06-11 18:19:31 +02001246 u8 score_curr, score_best;
1247
Daniel Borkmannea4f19c2014-08-22 13:03:29 +02001248 if (best == NULL || curr == best)
Daniel Borkmann4c47af42014-02-20 20:51:06 +01001249 return curr;
1250
Daniel Borkmanna7288c42014-06-11 18:19:31 +02001251 score_curr = sctp_trans_score(curr);
1252 score_best = sctp_trans_score(best);
1253
1254 /* First, try a score-based selection if both transport states
1255 * differ. If we're in a tie, lets try to make a more clever
1256 * decision here based on error counts and last time heard.
1257 */
1258 if (score_curr > score_best)
1259 return curr;
1260 else if (score_curr == score_best)
1261 return sctp_trans_elect_tie(curr, best);
1262 else
1263 return best;
Daniel Borkmann4c47af42014-02-20 20:51:06 +01001264}
1265
1266void sctp_assoc_update_retran_path(struct sctp_association *asoc)
1267{
1268 struct sctp_transport *trans = asoc->peer.retran_path;
1269 struct sctp_transport *trans_next = NULL;
1270
1271 /* We're done as we only have the one and only path. */
1272 if (asoc->peer.transport_count == 1)
1273 return;
1274 /* If active_path and retran_path are the same and active,
1275 * then this is the only active path. Use it.
1276 */
1277 if (asoc->peer.active_path == asoc->peer.retran_path &&
1278 asoc->peer.active_path->state == SCTP_ACTIVE)
1279 return;
1280
1281 /* Iterate from retran_path's successor back to retran_path. */
1282 for (trans = list_next_entry(trans, transports); 1;
1283 trans = list_next_entry(trans, transports)) {
1284 /* Manually skip the head element. */
1285 if (&trans->transports == &asoc->peer.transport_addr_list)
1286 continue;
1287 if (trans->state == SCTP_UNCONFIRMED)
1288 continue;
1289 trans_next = sctp_trans_elect_best(trans, trans_next);
1290 /* Active is good enough for immediate return. */
1291 if (trans_next->state == SCTP_ACTIVE)
1292 break;
1293 /* We've reached the end, time to update path. */
1294 if (trans == asoc->peer.retran_path)
1295 break;
1296 }
1297
Daniel Borkmann433131b2014-03-13 14:45:26 +01001298 asoc->peer.retran_path = trans_next;
Daniel Borkmann4c47af42014-02-20 20:51:06 +01001299
1300 pr_debug("%s: association:%p updated new path to addr:%pISpc\n",
1301 __func__, asoc, &asoc->peer.retran_path->ipaddr.sa);
1302}
1303
Daniel Borkmannb82e8f32014-06-11 18:19:29 +02001304static void sctp_select_active_and_retran_path(struct sctp_association *asoc)
1305{
1306 struct sctp_transport *trans, *trans_pri = NULL, *trans_sec = NULL;
Daniel Borkmanna7288c42014-06-11 18:19:31 +02001307 struct sctp_transport *trans_pf = NULL;
Daniel Borkmannb82e8f32014-06-11 18:19:29 +02001308
1309 /* Look for the two most recently used active transports. */
1310 list_for_each_entry(trans, &asoc->peer.transport_addr_list,
1311 transports) {
Daniel Borkmanna7288c42014-06-11 18:19:31 +02001312 /* Skip uninteresting transports. */
Daniel Borkmannb82e8f32014-06-11 18:19:29 +02001313 if (trans->state == SCTP_INACTIVE ||
Daniel Borkmanna7288c42014-06-11 18:19:31 +02001314 trans->state == SCTP_UNCONFIRMED)
Daniel Borkmannb82e8f32014-06-11 18:19:29 +02001315 continue;
Daniel Borkmanna7288c42014-06-11 18:19:31 +02001316 /* Keep track of the best PF transport from our
1317 * list in case we don't find an active one.
1318 */
1319 if (trans->state == SCTP_PF) {
1320 trans_pf = sctp_trans_elect_best(trans, trans_pf);
1321 continue;
1322 }
1323 /* For active transports, pick the most recent ones. */
Daniel Borkmannb82e8f32014-06-11 18:19:29 +02001324 if (trans_pri == NULL ||
Daniel Borkmanne575235f2014-06-11 18:19:30 +02001325 ktime_after(trans->last_time_heard,
1326 trans_pri->last_time_heard)) {
Daniel Borkmannb82e8f32014-06-11 18:19:29 +02001327 trans_sec = trans_pri;
1328 trans_pri = trans;
1329 } else if (trans_sec == NULL ||
Daniel Borkmanne575235f2014-06-11 18:19:30 +02001330 ktime_after(trans->last_time_heard,
1331 trans_sec->last_time_heard)) {
Daniel Borkmannb82e8f32014-06-11 18:19:29 +02001332 trans_sec = trans;
1333 }
1334 }
1335
1336 /* RFC 2960 6.4 Multi-Homed SCTP Endpoints
1337 *
1338 * By default, an endpoint should always transmit to the primary
1339 * path, unless the SCTP user explicitly specifies the
1340 * destination transport address (and possibly source transport
1341 * address) to use. [If the primary is active but not most recent,
1342 * bump the most recently used transport.]
1343 */
1344 if ((asoc->peer.primary_path->state == SCTP_ACTIVE ||
1345 asoc->peer.primary_path->state == SCTP_UNKNOWN) &&
1346 asoc->peer.primary_path != trans_pri) {
1347 trans_sec = trans_pri;
1348 trans_pri = asoc->peer.primary_path;
1349 }
1350
1351 /* We did not find anything useful for a possible retransmission
1352 * path; either primary path that we found is the the same as
1353 * the current one, or we didn't generally find an active one.
1354 */
1355 if (trans_sec == NULL)
1356 trans_sec = trans_pri;
1357
1358 /* If we failed to find a usable transport, just camp on the
Daniel Borkmannaa4a83e2014-08-22 13:03:30 +02001359 * active or pick a PF iff it's the better choice.
Daniel Borkmannb82e8f32014-06-11 18:19:29 +02001360 */
1361 if (trans_pri == NULL) {
Daniel Borkmannaa4a83e2014-08-22 13:03:30 +02001362 trans_pri = sctp_trans_elect_best(asoc->peer.active_path, trans_pf);
1363 trans_sec = trans_pri;
Daniel Borkmannb82e8f32014-06-11 18:19:29 +02001364 }
1365
1366 /* Set the active and retran transports. */
1367 asoc->peer.active_path = trans_pri;
1368 asoc->peer.retran_path = trans_sec;
1369}
1370
Daniel Borkmann4c47af42014-02-20 20:51:06 +01001371struct sctp_transport *
1372sctp_assoc_choose_alter_transport(struct sctp_association *asoc,
1373 struct sctp_transport *last_sent_to)
Frank Filz3f7a87d2005-06-20 13:14:57 -07001374{
Wei Yongjun9919b452009-05-12 21:52:51 +08001375 /* If this is the first time packet is sent, use the active path,
1376 * else use the retran path. If the last packet was sent over the
Frank Filz3f7a87d2005-06-20 13:14:57 -07001377 * retran path, update the retran path and use it.
1378 */
Daniel Borkmann4c47af42014-02-20 20:51:06 +01001379 if (last_sent_to == NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001380 return asoc->peer.active_path;
Daniel Borkmann4c47af42014-02-20 20:51:06 +01001381 } else {
Wei Yongjun9919b452009-05-12 21:52:51 +08001382 if (last_sent_to == asoc->peer.retran_path)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001383 sctp_assoc_update_retran_path(asoc);
Daniel Borkmann4c47af42014-02-20 20:51:06 +01001384
Linus Torvalds1da177e2005-04-16 15:20:36 -07001385 return asoc->peer.retran_path;
1386 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001387}
1388
1389/* Update the association's pmtu and frag_point by going through all the
1390 * transports. This routine is called when a transport's PMTU has changed.
1391 */
David S. Miller02f3d4c2012-07-16 03:57:14 -07001392void sctp_assoc_sync_pmtu(struct sock *sk, struct sctp_association *asoc)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001393{
1394 struct sctp_transport *t;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001395 __u32 pmtu = 0;
1396
1397 if (!asoc)
1398 return;
1399
1400 /* Get the lowest pmtu of all the transports. */
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -07001401 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1402 transports) {
Vlad Yasevich8a479492007-06-07 14:21:05 -04001403 if (t->pmtu_pending && t->dst) {
David S. Miller02f3d4c2012-07-16 03:57:14 -07001404 sctp_transport_update_pmtu(sk, t, dst_mtu(t->dst));
Vlad Yasevich8a479492007-06-07 14:21:05 -04001405 t->pmtu_pending = 0;
1406 }
Frank Filz52ccb8e2005-12-22 11:36:46 -08001407 if (!pmtu || (t->pathmtu < pmtu))
1408 pmtu = t->pathmtu;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001409 }
1410
1411 if (pmtu) {
Frank Filz52ccb8e2005-12-22 11:36:46 -08001412 asoc->pathmtu = pmtu;
Vlad Yasevichf68b2e02009-09-04 18:21:00 -04001413 asoc->frag_point = sctp_frag_point(asoc, pmtu);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001414 }
1415
Daniel Borkmannbb333812013-06-28 19:49:40 +02001416 pr_debug("%s: asoc:%p, pmtu:%d, frag_point:%d\n", __func__, asoc,
1417 asoc->pathmtu, asoc->frag_point);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001418}
1419
1420/* Should we send a SACK to update our peer? */
wangweidongce4a03d2013-12-06 09:36:29 +08001421static inline bool sctp_peer_needs_update(struct sctp_association *asoc)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001422{
Eric W. Biedermane1fc3b12012-08-07 07:29:57 +00001423 struct net *net = sock_net(asoc->base.sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001424 switch (asoc->state) {
1425 case SCTP_STATE_ESTABLISHED:
1426 case SCTP_STATE_SHUTDOWN_PENDING:
1427 case SCTP_STATE_SHUTDOWN_RECEIVED:
1428 case SCTP_STATE_SHUTDOWN_SENT:
1429 if ((asoc->rwnd > asoc->a_rwnd) &&
Vlad Yasevich90f2f532009-11-23 15:53:57 -05001430 ((asoc->rwnd - asoc->a_rwnd) >= max_t(__u32,
Eric W. Biedermane1fc3b12012-08-07 07:29:57 +00001431 (asoc->base.sk->sk_rcvbuf >> net->sctp.rwnd_upd_shift),
Vlad Yasevich90f2f532009-11-23 15:53:57 -05001432 asoc->pathmtu)))
wangweidongce4a03d2013-12-06 09:36:29 +08001433 return true;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001434 break;
1435 default:
1436 break;
1437 }
wangweidongce4a03d2013-12-06 09:36:29 +08001438 return false;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001439}
1440
Daniel Borkmann362d5202014-04-14 21:45:17 +02001441/* Increase asoc's rwnd by len and send any window update SACK if needed. */
1442void sctp_assoc_rwnd_increase(struct sctp_association *asoc, unsigned int len)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001443{
1444 struct sctp_chunk *sack;
1445 struct timer_list *timer;
1446
Daniel Borkmann362d5202014-04-14 21:45:17 +02001447 if (asoc->rwnd_over) {
1448 if (asoc->rwnd_over >= len) {
1449 asoc->rwnd_over -= len;
1450 } else {
1451 asoc->rwnd += (len - asoc->rwnd_over);
1452 asoc->rwnd_over = 0;
1453 }
1454 } else {
1455 asoc->rwnd += len;
1456 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001457
Daniel Borkmann362d5202014-04-14 21:45:17 +02001458 /* If we had window pressure, start recovering it
1459 * once our rwnd had reached the accumulated pressure
1460 * threshold. The idea is to recover slowly, but up
1461 * to the initial advertised window.
1462 */
1463 if (asoc->rwnd_press && asoc->rwnd >= asoc->rwnd_press) {
1464 int change = min(asoc->pathmtu, asoc->rwnd_press);
1465 asoc->rwnd += change;
1466 asoc->rwnd_press -= change;
1467 }
Vlad Yasevich4d3c46e2009-09-04 18:20:59 -04001468
Daniel Borkmann362d5202014-04-14 21:45:17 +02001469 pr_debug("%s: asoc:%p rwnd increased by %d to (%u, %u) - %u\n",
1470 __func__, asoc, len, asoc->rwnd, asoc->rwnd_over,
1471 asoc->a_rwnd);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001472
1473 /* Send a window update SACK if the rwnd has increased by at least the
1474 * minimum of the association's PMTU and half of the receive buffer.
1475 * The algorithm used is similar to the one described in
1476 * Section 4.2.3.3 of RFC 1122.
1477 */
Daniel Borkmann362d5202014-04-14 21:45:17 +02001478 if (sctp_peer_needs_update(asoc)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001479 asoc->a_rwnd = asoc->rwnd;
Daniel Borkmannbb333812013-06-28 19:49:40 +02001480
1481 pr_debug("%s: sending window update SACK- asoc:%p rwnd:%u "
1482 "a_rwnd:%u\n", __func__, asoc, asoc->rwnd,
1483 asoc->a_rwnd);
1484
Linus Torvalds1da177e2005-04-16 15:20:36 -07001485 sack = sctp_make_sack(asoc);
1486 if (!sack)
1487 return;
1488
1489 asoc->peer.sack_needed = 0;
1490
1491 sctp_outq_tail(&asoc->outqueue, sack);
1492
1493 /* Stop the SACK timer. */
1494 timer = &asoc->timers[SCTP_EVENT_TIMEOUT_SACK];
Ying Xue25cc4ae2013-02-03 20:32:57 +00001495 if (del_timer(timer))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001496 sctp_association_put(asoc);
1497 }
1498}
1499
Daniel Borkmann362d5202014-04-14 21:45:17 +02001500/* Decrease asoc's rwnd by len. */
1501void sctp_assoc_rwnd_decrease(struct sctp_association *asoc, unsigned int len)
1502{
1503 int rx_count;
1504 int over = 0;
1505
1506 if (unlikely(!asoc->rwnd || asoc->rwnd_over))
1507 pr_debug("%s: association:%p has asoc->rwnd:%u, "
1508 "asoc->rwnd_over:%u!\n", __func__, asoc,
1509 asoc->rwnd, asoc->rwnd_over);
1510
1511 if (asoc->ep->rcvbuf_policy)
1512 rx_count = atomic_read(&asoc->rmem_alloc);
1513 else
1514 rx_count = atomic_read(&asoc->base.sk->sk_rmem_alloc);
1515
1516 /* If we've reached or overflowed our receive buffer, announce
1517 * a 0 rwnd if rwnd would still be positive. Store the
1518 * the potential pressure overflow so that the window can be restored
1519 * back to original value.
1520 */
1521 if (rx_count >= asoc->base.sk->sk_rcvbuf)
1522 over = 1;
1523
1524 if (asoc->rwnd >= len) {
1525 asoc->rwnd -= len;
1526 if (over) {
1527 asoc->rwnd_press += asoc->rwnd;
1528 asoc->rwnd = 0;
1529 }
1530 } else {
1531 asoc->rwnd_over = len - asoc->rwnd;
1532 asoc->rwnd = 0;
1533 }
1534
1535 pr_debug("%s: asoc:%p rwnd decreased by %d to (%u, %u, %u)\n",
1536 __func__, asoc, len, asoc->rwnd, asoc->rwnd_over,
1537 asoc->rwnd_press);
1538}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001539
1540/* Build the bind address list for the association based on info from the
1541 * local endpoint and the remote peer.
1542 */
Alexey Dobriyan3182cd82005-07-11 20:57:47 -07001543int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
Vlad Yasevich409b95a2009-11-10 08:57:34 +00001544 sctp_scope_t scope, gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001545{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001546 int flags;
1547
1548 /* Use scoping rules to determine the subset of addresses from
1549 * the endpoint.
1550 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001551 flags = (PF_INET6 == asoc->base.sk->sk_family) ? SCTP_ADDR6_ALLOWED : 0;
1552 if (asoc->peer.ipv4_address)
1553 flags |= SCTP_ADDR4_PEERSUPP;
1554 if (asoc->peer.ipv6_address)
1555 flags |= SCTP_ADDR6_PEERSUPP;
1556
Eric W. Biederman4db67e82012-08-06 08:42:04 +00001557 return sctp_bind_addr_copy(sock_net(asoc->base.sk),
1558 &asoc->base.bind_addr,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001559 &asoc->ep->base.bind_addr,
1560 scope, gfp, flags);
1561}
1562
1563/* Build the association's bind address list from the cookie. */
1564int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *asoc,
Alexey Dobriyan3182cd82005-07-11 20:57:47 -07001565 struct sctp_cookie *cookie,
Al Virodd0fc662005-10-07 07:46:04 +01001566 gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001567{
1568 int var_size2 = ntohs(cookie->peer_init->chunk_hdr.length);
1569 int var_size3 = cookie->raw_addr_list_len;
1570 __u8 *raw = (__u8 *)cookie->peer_init + var_size2;
1571
1572 return sctp_raw_to_bind_addrs(&asoc->base.bind_addr, raw, var_size3,
1573 asoc->ep->base.bind_addr.port, gfp);
1574}
1575
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001576/* Lookup laddr in the bind address list of an association. */
1577int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001578 const union sctp_addr *laddr)
1579{
Vlad Yasevich559cf712007-09-16 16:03:28 -07001580 int found = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001581
Linus Torvalds1da177e2005-04-16 15:20:36 -07001582 if ((asoc->base.bind_addr.port == ntohs(laddr->v4.sin_port)) &&
1583 sctp_bind_addr_match(&asoc->base.bind_addr, laddr,
Vlad Yasevich559cf712007-09-16 16:03:28 -07001584 sctp_sk(asoc->base.sk)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001585 found = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001586
Linus Torvalds1da177e2005-04-16 15:20:36 -07001587 return found;
1588}
Vlad Yasevich07d93962007-05-04 13:55:27 -07001589
1590/* Set an association id for a given association */
1591int sctp_assoc_set_id(struct sctp_association *asoc, gfp_t gfp)
1592{
Daniel Borkmann9b87d462014-06-11 18:19:32 +02001593 bool preload = !!(gfp & __GFP_WAIT);
Tejun Heo94960e82013-02-27 17:05:00 -08001594 int ret;
Vlad Yasevichc6ba68a2009-06-01 12:41:15 -04001595
1596 /* If the id is already assigned, keep it. */
1597 if (asoc->assoc_id)
Tejun Heo94960e82013-02-27 17:05:00 -08001598 return 0;
Vlad Yasevich07d93962007-05-04 13:55:27 -07001599
Tejun Heo94960e82013-02-27 17:05:00 -08001600 if (preload)
1601 idr_preload(gfp);
Vlad Yasevich07d93962007-05-04 13:55:27 -07001602 spin_lock_bh(&sctp_assocs_id_lock);
Jeff Layton713e00a2013-04-29 16:21:22 -07001603 /* 0 is not a valid assoc_id, must be >= 1 */
1604 ret = idr_alloc_cyclic(&sctp_assocs_id, asoc, 1, 0, GFP_NOWAIT);
Vlad Yasevich07d93962007-05-04 13:55:27 -07001605 spin_unlock_bh(&sctp_assocs_id_lock);
Tejun Heo94960e82013-02-27 17:05:00 -08001606 if (preload)
1607 idr_preload_end();
1608 if (ret < 0)
1609 return ret;
Vlad Yasevich07d93962007-05-04 13:55:27 -07001610
Tejun Heo94960e82013-02-27 17:05:00 -08001611 asoc->assoc_id = (sctp_assoc_t)ret;
1612 return 0;
Vlad Yasevich07d93962007-05-04 13:55:27 -07001613}
Vlad Yasevicha08de642007-12-20 14:11:47 -08001614
Wei Yongjun8b4472c2011-05-24 21:48:02 +00001615/* Free the ASCONF queue */
1616static void sctp_assoc_free_asconf_queue(struct sctp_association *asoc)
1617{
1618 struct sctp_chunk *asconf;
1619 struct sctp_chunk *tmp;
1620
1621 list_for_each_entry_safe(asconf, tmp, &asoc->addip_chunk_list, list) {
1622 list_del_init(&asconf->list);
1623 sctp_chunk_free(asconf);
1624 }
1625}
1626
Vlad Yasevicha08de642007-12-20 14:11:47 -08001627/* Free asconf_ack cache */
1628static void sctp_assoc_free_asconf_acks(struct sctp_association *asoc)
1629{
1630 struct sctp_chunk *ack;
1631 struct sctp_chunk *tmp;
1632
1633 list_for_each_entry_safe(ack, tmp, &asoc->asconf_ack_list,
1634 transmitted_list) {
1635 list_del_init(&ack->transmitted_list);
1636 sctp_chunk_free(ack);
1637 }
1638}
1639
1640/* Clean up the ASCONF_ACK queue */
1641void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc)
1642{
1643 struct sctp_chunk *ack;
1644 struct sctp_chunk *tmp;
1645
Lucas De Marchi25985ed2011-03-30 22:57:33 -03001646 /* We can remove all the entries from the queue up to
Vlad Yasevicha08de642007-12-20 14:11:47 -08001647 * the "Peer-Sequence-Number".
1648 */
1649 list_for_each_entry_safe(ack, tmp, &asoc->asconf_ack_list,
1650 transmitted_list) {
1651 if (ack->subh.addip_hdr->serial ==
1652 htonl(asoc->peer.addip_serial))
1653 break;
1654
1655 list_del_init(&ack->transmitted_list);
1656 sctp_chunk_free(ack);
1657 }
1658}
1659
1660/* Find the ASCONF_ACK whose serial number matches ASCONF */
1661struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
1662 const struct sctp_association *asoc,
1663 __be32 serial)
1664{
Wei Yongjuna8699812008-02-05 23:35:04 +09001665 struct sctp_chunk *ack;
Vlad Yasevicha08de642007-12-20 14:11:47 -08001666
1667 /* Walk through the list of cached ASCONF-ACKs and find the
1668 * ack chunk whose serial number matches that of the request.
1669 */
1670 list_for_each_entry(ack, &asoc->asconf_ack_list, transmitted_list) {
Daniel Borkmannb69040d2014-10-09 22:55:32 +02001671 if (sctp_chunk_pending(ack))
1672 continue;
Vlad Yasevicha08de642007-12-20 14:11:47 -08001673 if (ack->subh.addip_hdr->serial == serial) {
1674 sctp_chunk_hold(ack);
Wei Yongjuna8699812008-02-05 23:35:04 +09001675 return ack;
Vlad Yasevicha08de642007-12-20 14:11:47 -08001676 }
1677 }
1678
Wei Yongjuna8699812008-02-05 23:35:04 +09001679 return NULL;
Vlad Yasevicha08de642007-12-20 14:11:47 -08001680}
Wei Yongjuna000c012011-05-29 23:23:36 +00001681
1682void sctp_asconf_queue_teardown(struct sctp_association *asoc)
1683{
1684 /* Free any cached ASCONF_ACK chunk. */
1685 sctp_assoc_free_asconf_acks(asoc);
1686
1687 /* Free the ASCONF queue. */
1688 sctp_assoc_free_asconf_queue(asoc);
1689
1690 /* Free any cached ASCONF chunk. */
1691 if (asoc->addip_last_asconf)
1692 sctp_chunk_free(asoc->addip_last_asconf);
1693}