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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;
Vlad Yasevicha29a5bd2007-09-16 19:31:35 -070074 sctp_paramhdr_t *p;
Xin Long58194772017-03-20 18:00:28 +080075 int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -070076
77 /* Retrieve the SCTP per socket area. */
78 sp = sctp_sk((struct sock *)sk);
79
Linus Torvalds1da177e2005-04-16 15:20:36 -070080 /* Discarding const is appropriate here. */
81 asoc->ep = (struct sctp_endpoint *)ep;
Linus Torvalds1da177e2005-04-16 15:20:36 -070082 asoc->base.sk = (struct sock *)sk;
Daniel Borkmann2e0c9e72013-06-14 18:24:07 +020083
84 sctp_endpoint_hold(asoc->ep);
Linus Torvalds1da177e2005-04-16 15:20:36 -070085 sock_hold(asoc->base.sk);
86
87 /* Initialize the common base substructure. */
88 asoc->base.type = SCTP_EP_TYPE_ASSOCIATION;
89
90 /* Initialize the object handling fields. */
91 atomic_set(&asoc->base.refcnt, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -070092
93 /* Initialize the bind addr area. */
94 sctp_bind_addr_init(&asoc->base.bind_addr, ep->base.bind_addr.port);
Linus Torvalds1da177e2005-04-16 15:20:36 -070095
96 asoc->state = SCTP_STATE_CLOSED;
Daniel Borkmann52db8822013-06-25 18:17:27 +020097 asoc->cookie_life = ms_to_ktime(sp->assocparams.sasoc_cookie_life);
Vlad Yasevichf68b2e02009-09-04 18:21:00 -040098 asoc->user_frag = sp->user_frag;
Linus Torvalds1da177e2005-04-16 15:20:36 -070099
100 /* Set the association max_retrans and RTO values from the
101 * socket values.
102 */
103 asoc->max_retrans = sp->assocparams.sasoc_asocmaxrxt;
Eric W. Biedermane1fc3b12012-08-07 07:29:57 +0000104 asoc->pf_retrans = net->sctp.pf_retrans;
Neil Horman5aa93bc2012-07-21 07:56:07 +0000105
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106 asoc->rto_initial = msecs_to_jiffies(sp->rtoinfo.srto_initial);
107 asoc->rto_max = msecs_to_jiffies(sp->rtoinfo.srto_max);
108 asoc->rto_min = msecs_to_jiffies(sp->rtoinfo.srto_min);
109
Frank Filz52ccb8e2005-12-22 11:36:46 -0800110 /* Initialize the association's heartbeat interval based on the
111 * sock configured value.
112 */
113 asoc->hbinterval = msecs_to_jiffies(sp->hbinterval);
114
115 /* Initialize path max retrans value. */
116 asoc->pathmaxrxt = sp->pathmaxrxt;
117
118 /* Initialize default path MTU. */
119 asoc->pathmtu = sp->pathmtu;
120
121 /* Set association default SACK delay */
122 asoc->sackdelay = msecs_to_jiffies(sp->sackdelay);
Wei Yongjund364d922008-05-09 15:13:26 -0700123 asoc->sackfreq = sp->sackfreq;
Frank Filz52ccb8e2005-12-22 11:36:46 -0800124
125 /* Set the association default flags controlling
126 * Heartbeat, SACK delay, and Path MTU Discovery.
127 */
128 asoc->param_flags = sp->param_flags;
129
wangweidong9d2c8812013-12-06 09:36:30 +0800130 /* Initialize the maximum number of new data packets that can be sent
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131 * in a burst.
132 */
Vlad Yasevich70331572007-03-23 11:34:36 -0700133 asoc->max_burst = sp->max_burst;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134
Vladislav Yasevich1e7d3d92005-11-11 16:06:16 -0800135 /* initialize association timers */
Vladislav Yasevich1e7d3d92005-11-11 16:06:16 -0800136 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_COOKIE] = asoc->rto_initial;
137 asoc->timeouts[SCTP_EVENT_TIMEOUT_T1_INIT] = asoc->rto_initial;
138 asoc->timeouts[SCTP_EVENT_TIMEOUT_T2_SHUTDOWN] = asoc->rto_initial;
Vladislav Yasevich1e7d3d92005-11-11 16:06:16 -0800139
140 /* sctpimpguide Section 2.12.2
141 * If the 'T5-shutdown-guard' timer is used, it SHOULD be set to the
142 * recommended value of 5 times 'RTO.Max'.
143 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900144 asoc->timeouts[SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD]
Vladislav Yasevich1e7d3d92005-11-11 16:06:16 -0800145 = 5 * asoc->rto_max;
146
Frank Filz52ccb8e2005-12-22 11:36:46 -0800147 asoc->timeouts[SCTP_EVENT_TIMEOUT_SACK] = asoc->sackdelay;
Neil Horman9f70f462013-12-10 06:48:15 -0500148 asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE] = sp->autoclose * HZ;
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900149
Uwe Kleine-König421f91d2010-06-11 12:17:00 +0200150 /* Initializes the timers */
Pavel Emelyanovb24b8a22008-01-23 21:20:07 -0800151 for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i)
152 setup_timer(&asoc->timers[i], sctp_timer_events[i],
153 (unsigned long)asoc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154
155 /* Pull default initialization values from the sock options.
156 * Note: This assumes that the values have already been
157 * validated in the sock.
158 */
159 asoc->c.sinit_max_instreams = sp->initmsg.sinit_max_instreams;
160 asoc->c.sinit_num_ostreams = sp->initmsg.sinit_num_ostreams;
161 asoc->max_init_attempts = sp->initmsg.sinit_max_attempts;
162
163 asoc->max_init_timeo =
164 msecs_to_jiffies(sp->initmsg.sinit_max_init_timeo);
165
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166 /* Set the local window size for receive.
167 * This is also the rcvbuf space per association.
168 * RFC 6 - A SCTP receiver MUST be able to receive a minimum of
169 * 1500 bytes in one SCTP packet.
170 */
Neil Horman049b3ff2005-11-11 16:08:24 -0800171 if ((sk->sk_rcvbuf/2) < SCTP_DEFAULT_MINWINDOW)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172 asoc->rwnd = SCTP_DEFAULT_MINWINDOW;
173 else
Neil Horman049b3ff2005-11-11 16:08:24 -0800174 asoc->rwnd = sk->sk_rcvbuf/2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175
176 asoc->a_rwnd = asoc->rwnd;
177
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178 /* Use my own max window until I learn something better. */
179 asoc->peer.rwnd = SCTP_DEFAULT_MAXWINDOW;
180
Neil Horman049b3ff2005-11-11 16:08:24 -0800181 /* Initialize the receive memory counter */
182 atomic_set(&asoc->rmem_alloc, 0);
183
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184 init_waitqueue_head(&asoc->wait);
185
186 asoc->c.my_vtag = sctp_generate_tag(ep);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 asoc->c.my_port = ep->base.bind_addr.port;
188
189 asoc->c.initial_tsn = sctp_generate_tsn(ep);
190
191 asoc->next_tsn = asoc->c.initial_tsn;
192
193 asoc->ctsn_ack_point = asoc->next_tsn - 1;
194 asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
195 asoc->highest_sacked = asoc->ctsn_ack_point;
196 asoc->last_cwr_tsn = asoc->ctsn_ack_point;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198 /* ADDIP Section 4.1 Asconf Chunk Procedures
199 *
200 * When an endpoint has an ASCONF signaled change to be sent to the
201 * remote endpoint it should do the following:
202 * ...
203 * A2) a serial number should be assigned to the chunk. The serial
204 * number SHOULD be a monotonically increasing number. The serial
205 * numbers SHOULD be initialized at the start of the
206 * association to the same value as the initial TSN.
207 */
208 asoc->addip_serial = asoc->c.initial_tsn;
Xin Longcc16f002017-01-18 00:44:42 +0800209 asoc->strreset_outseq = asoc->c.initial_tsn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210
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);
Xin Long58194772017-03-20 18:00:28 +0800266 if (sctp_auth_asoc_copy_shkeys(ep, asoc, gfp))
Vlad Yasevicha29a5bd2007-09-16 19:31:35 -0700267 goto fail_init;
268
269 asoc->active_key_id = ep->active_key_id;
Xin Long28aa4c22016-07-09 19:47:40 +0800270 asoc->prsctp_enable = ep->prsctp_enable;
Xin Longc28445c2017-01-18 00:44:45 +0800271 asoc->reconf_enable = ep->reconf_enable;
Xin Long9fb657a2017-01-18 00:44:46 +0800272 asoc->strreset_enable = ep->strreset_enable;
Vlad Yasevicha29a5bd2007-09-16 19:31:35 -0700273
Vlad Yasevicha29a5bd2007-09-16 19:31:35 -0700274 /* Save the hmacs and chunks list into this association */
275 if (ep->auth_hmacs_list)
276 memcpy(asoc->c.auth_hmacs, ep->auth_hmacs_list,
277 ntohs(ep->auth_hmacs_list->param_hdr.length));
278 if (ep->auth_chunk_list)
279 memcpy(asoc->c.auth_chunks, ep->auth_chunk_list,
280 ntohs(ep->auth_chunk_list->param_hdr.length));
281
282 /* Get the AUTH random number for this association */
283 p = (sctp_paramhdr_t *)asoc->c.auth_random;
284 p->type = SCTP_PARAM_RANDOM;
285 p->length = htons(sizeof(sctp_paramhdr_t) + SCTP_AUTH_RANDOM_LENGTH);
286 get_random_bytes(p+1, SCTP_AUTH_RANDOM_LENGTH);
287
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288 return asoc;
289
290fail_init:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291 sock_put(asoc->base.sk);
Daniel Borkmann2e0c9e72013-06-14 18:24:07 +0200292 sctp_endpoint_put(asoc->ep);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293 return NULL;
294}
295
296/* Allocate and initialize a new association */
297struct sctp_association *sctp_association_new(const struct sctp_endpoint *ep,
298 const struct sock *sk,
Alexey Dobriyan3182cd82005-07-11 20:57:47 -0700299 sctp_scope_t scope,
Al Virodd0fc662005-10-07 07:46:04 +0100300 gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301{
302 struct sctp_association *asoc;
303
Daniel Borkmann939cfa72013-06-17 11:40:04 +0200304 asoc = kzalloc(sizeof(*asoc), gfp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305 if (!asoc)
306 goto fail;
307
308 if (!sctp_association_init(asoc, ep, sk, scope, gfp))
309 goto fail_init;
310
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311 SCTP_DBG_OBJCNT_INC(assoc);
Daniel Borkmannbb333812013-06-28 19:49:40 +0200312
313 pr_debug("Created asoc %p\n", asoc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700314
315 return asoc;
316
317fail_init:
318 kfree(asoc);
319fail:
320 return NULL;
321}
322
323/* Free this association if possible. There may still be users, so
324 * the actual deallocation may be delayed.
325 */
326void sctp_association_free(struct sctp_association *asoc)
327{
328 struct sock *sk = asoc->base.sk;
329 struct sctp_transport *transport;
330 struct list_head *pos, *temp;
331 int i;
332
Vlad Yasevichde76e692006-10-30 18:55:11 -0800333 /* Only real associations count against the endpoint, so
334 * don't bother for if this is a temporary association.
335 */
Xufeng Zhangd3217b12014-06-12 10:53:36 +0800336 if (!list_empty(&asoc->asocs)) {
Vlad Yasevichde76e692006-10-30 18:55:11 -0800337 list_del(&asoc->asocs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338
Vlad Yasevichde76e692006-10-30 18:55:11 -0800339 /* Decrement the backlog value for a TCP-style listening
340 * socket.
341 */
342 if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
343 sk->sk_ack_backlog--;
344 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345
346 /* Mark as dead, so other users can know this structure is
347 * going away.
348 */
Daniel Borkmann0022d2d2013-04-15 03:27:18 +0000349 asoc->base.dead = true;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350
351 /* Dispose of any data lying around in the outqueue. */
352 sctp_outq_free(&asoc->outqueue);
353
354 /* Dispose of any pending messages for the upper layer. */
355 sctp_ulpq_free(&asoc->ulpq);
356
357 /* Dispose of any pending chunks on the inqueue. */
358 sctp_inq_free(&asoc->base.inqueue);
359
Vlad Yasevich8e1ee182008-10-08 14:18:39 -0700360 sctp_tsnmap_free(&asoc->peer.tsn_map);
361
Xin Longa8386312017-01-06 22:18:33 +0800362 /* Free stream information. */
363 sctp_stream_free(asoc->stream);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364
Xin Long7b9438d2017-01-18 00:44:43 +0800365 if (asoc->strreset_chunk)
366 sctp_chunk_free(asoc->strreset_chunk);
367
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368 /* Clean up the bound address list. */
369 sctp_bind_addr_free(&asoc->base.bind_addr);
370
371 /* Do we need to go through all of our timers and
372 * delete them? To be safe we will try to delete all, but we
373 * should be able to go through and make a guess based
374 * on our state.
375 */
376 for (i = SCTP_EVENT_TIMEOUT_NONE; i < SCTP_NUM_TIMEOUT_TYPES; ++i) {
Ying Xue25cc4ae2013-02-03 20:32:57 +0000377 if (del_timer(&asoc->timers[i]))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378 sctp_association_put(asoc);
379 }
380
381 /* Free peer's cached cookie. */
Jesper Juhla51482b2005-11-08 09:41:34 -0800382 kfree(asoc->peer.cookie);
Vlad Yasevich730fc3d2007-09-16 19:32:11 -0700383 kfree(asoc->peer.peer_random);
384 kfree(asoc->peer.peer_chunks);
385 kfree(asoc->peer.peer_hmacs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386
387 /* Release the transport structures. */
388 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
389 transport = list_entry(pos, struct sctp_transport, transports);
Thomas Graf45122ca262012-12-06 09:25:05 +0000390 list_del_rcu(pos);
Xin Long4f008782015-12-30 23:50:47 +0800391 sctp_unhash_transport(transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392 sctp_transport_free(transport);
393 }
394
Frank Filz3f7a87d2005-06-20 13:14:57 -0700395 asoc->peer.transport_count = 0;
396
Wei Yongjuna000c012011-05-29 23:23:36 +0000397 sctp_asconf_queue_teardown(asoc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398
Michio Honda8a07eb02011-04-26 20:19:36 +0900399 /* Free pending address space being deleted */
Markus Elfring7d37d0c2015-01-31 18:10:03 +0100400 kfree(asoc->asconf_addr_del_pending);
Michio Honda8a07eb02011-04-26 20:19:36 +0900401
Vlad Yasevicha29a5bd2007-09-16 19:31:35 -0700402 /* AUTH - Free the endpoint shared keys */
403 sctp_auth_destroy_keys(&asoc->endpoint_shared_keys);
404
405 /* AUTH - Free the association shared key */
406 sctp_auth_key_put(asoc->asoc_shared_key);
407
Linus Torvalds1da177e2005-04-16 15:20:36 -0700408 sctp_association_put(asoc);
409}
410
411/* Cleanup and free up an association. */
412static void sctp_association_destroy(struct sctp_association *asoc)
413{
Daniel Borkmannbb333812013-06-28 19:49:40 +0200414 if (unlikely(!asoc->base.dead)) {
415 WARN(1, "Attempt to destroy undead association %p!\n", asoc);
416 return;
417 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418
419 sctp_endpoint_put(asoc->ep);
420 sock_put(asoc->base.sk);
421
422 if (asoc->assoc_id != 0) {
423 spin_lock_bh(&sctp_assocs_id_lock);
424 idr_remove(&sctp_assocs_id, asoc->assoc_id);
425 spin_unlock_bh(&sctp_assocs_id_lock);
426 }
427
Ilpo Järvinen547b7922008-07-25 21:43:18 -0700428 WARN_ON(atomic_read(&asoc->rmem_alloc));
Neil Horman049b3ff2005-11-11 16:08:24 -0800429
Daniel Borkmannff2266c2013-04-15 03:27:17 +0000430 kfree(asoc);
431 SCTP_DBG_OBJCNT_DEC(assoc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432}
433
434/* Change the primary destination address for the peer. */
435void sctp_assoc_set_primary(struct sctp_association *asoc,
436 struct sctp_transport *transport)
437{
Vlad Yasevich319fa2a2008-06-16 17:00:29 -0700438 int changeover = 0;
439
440 /* it's a changeover only if we already have a primary path
441 * that we are changing
442 */
443 if (asoc->peer.primary_path != NULL &&
444 asoc->peer.primary_path != transport)
445 changeover = 1 ;
446
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447 asoc->peer.primary_path = transport;
448
449 /* Set a default msg_name for events. */
450 memcpy(&asoc->peer.primary_addr, &transport->ipaddr,
451 sizeof(union sctp_addr));
452
453 /* If the primary path is changing, assume that the
454 * user wants to use this new path.
455 */
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700456 if ((transport->state == SCTP_ACTIVE) ||
457 (transport->state == SCTP_UNKNOWN))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700458 asoc->peer.active_path = transport;
459
460 /*
461 * SFR-CACC algorithm:
462 * Upon the receipt of a request to change the primary
463 * destination address, on the data structure for the new
464 * primary destination, the sender MUST do the following:
465 *
466 * 1) If CHANGEOVER_ACTIVE is set, then there was a switch
467 * to this destination address earlier. The sender MUST set
468 * CYCLING_CHANGEOVER to indicate that this switch is a
469 * double switch to the same destination address.
Vlad Yaseviche0e9db12009-11-23 15:53:57 -0500470 *
471 * Really, only bother is we have data queued or outstanding on
472 * the association.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700473 */
Vlad Yaseviche0e9db12009-11-23 15:53:57 -0500474 if (!asoc->outqueue.outstanding_bytes && !asoc->outqueue.out_qlen)
475 return;
476
Linus Torvalds1da177e2005-04-16 15:20:36 -0700477 if (transport->cacc.changeover_active)
Vlad Yasevich319fa2a2008-06-16 17:00:29 -0700478 transport->cacc.cycling_changeover = changeover;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479
480 /* 2) The sender MUST set CHANGEOVER_ACTIVE to indicate that
481 * a changeover has occurred.
482 */
Vlad Yasevich319fa2a2008-06-16 17:00:29 -0700483 transport->cacc.changeover_active = changeover;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484
485 /* 3) The sender MUST store the next TSN to be sent in
486 * next_tsn_at_change.
487 */
488 transport->cacc.next_tsn_at_change = asoc->next_tsn;
489}
490
Frank Filz3f7a87d2005-06-20 13:14:57 -0700491/* Remove a transport from an association. */
492void sctp_assoc_rm_peer(struct sctp_association *asoc,
493 struct sctp_transport *peer)
494{
495 struct list_head *pos;
496 struct sctp_transport *transport;
497
Daniel Borkmannbb333812013-06-28 19:49:40 +0200498 pr_debug("%s: association:%p addr:%pISpc\n",
499 __func__, asoc, &peer->ipaddr.sa);
Frank Filz3f7a87d2005-06-20 13:14:57 -0700500
501 /* If we are to remove the current retran_path, update it
502 * to the next peer before removing this peer from the list.
503 */
504 if (asoc->peer.retran_path == peer)
505 sctp_assoc_update_retran_path(asoc);
506
507 /* Remove this peer from the list. */
Thomas Graf45122ca262012-12-06 09:25:05 +0000508 list_del_rcu(&peer->transports);
Xin Long4f008782015-12-30 23:50:47 +0800509 /* Remove this peer from the transport hashtable */
510 sctp_unhash_transport(peer);
Frank Filz3f7a87d2005-06-20 13:14:57 -0700511
512 /* Get the first transport of asoc. */
513 pos = asoc->peer.transport_addr_list.next;
514 transport = list_entry(pos, struct sctp_transport, transports);
515
516 /* Update any entries that match the peer to be deleted. */
517 if (asoc->peer.primary_path == peer)
518 sctp_assoc_set_primary(asoc, transport);
519 if (asoc->peer.active_path == peer)
520 asoc->peer.active_path = transport;
Wei Yongjun9494c7c2011-04-12 15:22:22 +0000521 if (asoc->peer.retran_path == peer)
522 asoc->peer.retran_path = transport;
Frank Filz3f7a87d2005-06-20 13:14:57 -0700523 if (asoc->peer.last_data_from == peer)
524 asoc->peer.last_data_from = transport;
525
Xin Long7b9438d2017-01-18 00:44:43 +0800526 if (asoc->strreset_chunk &&
527 asoc->strreset_chunk->transport == peer) {
528 asoc->strreset_chunk->transport = transport;
529 sctp_transport_reset_reconf_timer(transport);
530 }
531
Frank Filz3f7a87d2005-06-20 13:14:57 -0700532 /* If we remove the transport an INIT was last sent to, set it to
533 * NULL. Combined with the update of the retran path above, this
534 * will cause the next INIT to be sent to the next available
535 * transport, maintaining the cycle.
536 */
537 if (asoc->init_last_sent_to == peer)
538 asoc->init_last_sent_to = NULL;
539
Wei Yongjun6345b192009-04-26 23:13:35 +0800540 /* If we remove the transport an SHUTDOWN was last sent to, set it
541 * to NULL. Combined with the update of the retran path above, this
542 * will cause the next SHUTDOWN to be sent to the next available
543 * transport, maintaining the cycle.
544 */
545 if (asoc->shutdown_last_sent_to == peer)
546 asoc->shutdown_last_sent_to = NULL;
547
Wei Yongjun10a43ce2009-04-26 23:14:42 +0800548 /* If we remove the transport an ASCONF was last sent to, set it to
549 * NULL.
550 */
551 if (asoc->addip_last_asconf &&
552 asoc->addip_last_asconf->transport == peer)
553 asoc->addip_last_asconf->transport = NULL;
554
Vlad Yasevich31b02e12009-09-04 18:21:00 -0400555 /* If we have something on the transmitted list, we have to
556 * save it off. The best place is the active path.
557 */
558 if (!list_empty(&peer->transmitted)) {
559 struct sctp_transport *active = asoc->peer.active_path;
560 struct sctp_chunk *ch;
561
562 /* Reset the transport of each chunk on this list */
563 list_for_each_entry(ch, &peer->transmitted,
564 transmitted_list) {
565 ch->transport = NULL;
566 ch->rtt_in_progress = 0;
567 }
568
569 list_splice_tail_init(&peer->transmitted,
570 &active->transmitted);
571
572 /* Start a T3 timer here in case it wasn't running so
573 * that these migrated packets have a chance to get
wangweidong2bccbad2013-10-26 16:06:30 +0800574 * retransmitted.
Vlad Yasevich31b02e12009-09-04 18:21:00 -0400575 */
576 if (!timer_pending(&active->T3_rtx_timer))
577 if (!mod_timer(&active->T3_rtx_timer,
578 jiffies + active->rto))
579 sctp_transport_hold(active);
580 }
581
Frank Filz3f7a87d2005-06-20 13:14:57 -0700582 asoc->peer.transport_count--;
583
584 sctp_transport_free(peer);
585}
586
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587/* Add a transport address to an association. */
588struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc,
589 const union sctp_addr *addr,
Al Virodd0fc662005-10-07 07:46:04 +0100590 const gfp_t gfp,
Frank Filz3f7a87d2005-06-20 13:14:57 -0700591 const int peer_state)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700592{
Eric W. Biederman89bf3452012-08-07 07:26:14 +0000593 struct net *net = sock_net(asoc->base.sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700594 struct sctp_transport *peer;
595 struct sctp_sock *sp;
596 unsigned short port;
597
598 sp = sctp_sk(asoc->base.sk);
599
600 /* AF_INET and AF_INET6 share common port field. */
Al Viro4bdf4b52006-11-20 17:10:20 -0800601 port = ntohs(addr->v4.sin_port);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602
Daniel Borkmannbb333812013-06-28 19:49:40 +0200603 pr_debug("%s: association:%p addr:%pISpc state:%d\n", __func__,
604 asoc, &addr->sa, peer_state);
Frank Filz3f7a87d2005-06-20 13:14:57 -0700605
Linus Torvalds1da177e2005-04-16 15:20:36 -0700606 /* Set the port if it has not been set yet. */
607 if (0 == asoc->peer.port)
608 asoc->peer.port = port;
609
610 /* Check to see if this is a duplicate. */
611 peer = sctp_assoc_lookup_paddr(asoc, addr);
Frank Filz3f7a87d2005-06-20 13:14:57 -0700612 if (peer) {
Vlad Yasevichadd52372008-09-18 16:28:27 -0700613 /* An UNKNOWN state is only set on transports added by
614 * user in sctp_connectx() call. Such transports should be
615 * considered CONFIRMED per RFC 4960, Section 5.4.
616 */
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700617 if (peer->state == SCTP_UNKNOWN) {
Vlad Yasevichadd52372008-09-18 16:28:27 -0700618 peer->state = SCTP_ACTIVE;
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700619 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700620 return peer;
Frank Filz3f7a87d2005-06-20 13:14:57 -0700621 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700622
Eric W. Biederman89bf3452012-08-07 07:26:14 +0000623 peer = sctp_transport_new(net, addr, gfp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700624 if (!peer)
625 return NULL;
626
627 sctp_transport_set_owner(peer, asoc);
628
Frank Filz52ccb8e2005-12-22 11:36:46 -0800629 /* Initialize the peer's heartbeat interval based on the
630 * association configured value.
631 */
632 peer->hbinterval = asoc->hbinterval;
633
634 /* Set the path max_retrans. */
635 peer->pathmaxrxt = asoc->pathmaxrxt;
636
wangweidong2bccbad2013-10-26 16:06:30 +0800637 /* And the partial failure retrans threshold */
Neil Horman5aa93bc2012-07-21 07:56:07 +0000638 peer->pf_retrans = asoc->pf_retrans;
639
Frank Filz52ccb8e2005-12-22 11:36:46 -0800640 /* Initialize the peer's SACK delay timeout based on the
641 * association configured value.
642 */
643 peer->sackdelay = asoc->sackdelay;
Wei Yongjund364d922008-05-09 15:13:26 -0700644 peer->sackfreq = asoc->sackfreq;
Frank Filz52ccb8e2005-12-22 11:36:46 -0800645
646 /* Enable/disable heartbeat, SACK delay, and path MTU discovery
647 * based on association setting.
648 */
649 peer->param_flags = asoc->param_flags;
650
Vlad Yasevich8da645e2009-09-04 18:21:01 -0400651 sctp_transport_route(peer, NULL, sp);
652
Linus Torvalds1da177e2005-04-16 15:20:36 -0700653 /* Initialize the pmtu of the transport. */
Vlad Yasevich8da645e2009-09-04 18:21:01 -0400654 if (peer->param_flags & SPP_PMTUD_DISABLE) {
655 if (asoc->pathmtu)
656 peer->pathmtu = asoc->pathmtu;
657 else
658 peer->pathmtu = SCTP_DEFAULT_MAXSEGMENT;
659 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700660
661 /* If this is the first transport addr on this association,
662 * initialize the association PMTU to the peer's PMTU.
663 * If not and the current association PMTU is higher than the new
664 * peer's PMTU, reset the association PMTU to the new peer's PMTU.
665 */
Frank Filz52ccb8e2005-12-22 11:36:46 -0800666 if (asoc->pathmtu)
667 asoc->pathmtu = min_t(int, peer->pathmtu, asoc->pathmtu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668 else
Frank Filz52ccb8e2005-12-22 11:36:46 -0800669 asoc->pathmtu = peer->pathmtu;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670
Daniel Borkmannbb333812013-06-28 19:49:40 +0200671 pr_debug("%s: association:%p PMTU set to %d\n", __func__, asoc,
672 asoc->pathmtu);
673
Florian Westphal6d0ccba2008-07-18 23:04:39 -0700674 peer->pmtu_pending = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675
Vlad Yasevichf68b2e02009-09-04 18:21:00 -0400676 asoc->frag_point = sctp_frag_point(asoc, asoc->pathmtu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677
678 /* The asoc->peer.port might not be meaningful yet, but
679 * initialize the packet structure anyway.
680 */
681 sctp_packet_init(&peer->packet, peer, asoc->base.bind_addr.port,
682 asoc->peer.port);
683
684 /* 7.2.1 Slow-Start
685 *
686 * o The initial cwnd before DATA transmission or after a sufficiently
687 * long idle period MUST be set to
688 * min(4*MTU, max(2*MTU, 4380 bytes))
689 *
690 * o The initial value of ssthresh MAY be arbitrarily high
691 * (for example, implementations MAY use the size of the
692 * receiver advertised window).
693 */
Frank Filz52ccb8e2005-12-22 11:36:46 -0800694 peer->cwnd = min(4*asoc->pathmtu, max_t(__u32, 2*asoc->pathmtu, 4380));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695
696 /* At this point, we may not have the receiver's advertised window,
697 * so initialize ssthresh to the default value and it will be set
698 * later when we process the INIT.
699 */
700 peer->ssthresh = SCTP_DEFAULT_MAXWINDOW;
701
702 peer->partial_bytes_acked = 0;
703 peer->flight_size = 0;
Vlad Yasevich46d5a802009-11-23 15:54:00 -0500704 peer->burst_limited = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700705
Linus Torvalds1da177e2005-04-16 15:20:36 -0700706 /* Set the transport's RTO.initial value */
707 peer->rto = asoc->rto_initial;
Michele Baldessari196d6752012-12-01 04:49:42 +0000708 sctp_max_rto(asoc, peer);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709
Frank Filz3f7a87d2005-06-20 13:14:57 -0700710 /* Set the peer's active state. */
711 peer->state = peer_state;
712
Xin Long7fda7022016-11-15 23:23:11 +0800713 /* Add this peer into the transport hashtable */
714 if (sctp_hash_transport(peer)) {
715 sctp_transport_free(peer);
716 return NULL;
717 }
718
Linus Torvalds1da177e2005-04-16 15:20:36 -0700719 /* Attach the remote transport to our asoc. */
Thomas Graf45122ca262012-12-06 09:25:05 +0000720 list_add_tail_rcu(&peer->transports, &asoc->peer.transport_addr_list);
Frank Filz3f7a87d2005-06-20 13:14:57 -0700721 asoc->peer.transport_count++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700722
723 /* If we do not yet have a primary path, set one. */
724 if (!asoc->peer.primary_path) {
725 sctp_assoc_set_primary(asoc, peer);
726 asoc->peer.retran_path = peer;
727 }
728
Vlad Yasevichfbdf5012010-04-30 22:39:26 -0400729 if (asoc->peer.active_path == asoc->peer.retran_path &&
730 peer->state != SCTP_UNCONFIRMED) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731 asoc->peer.retran_path = peer;
Frank Filz3f7a87d2005-06-20 13:14:57 -0700732 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700733
734 return peer;
735}
736
737/* Delete a transport address from an association. */
738void sctp_assoc_del_peer(struct sctp_association *asoc,
739 const union sctp_addr *addr)
740{
741 struct list_head *pos;
742 struct list_head *temp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700743 struct sctp_transport *transport;
744
745 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
746 transport = list_entry(pos, struct sctp_transport, transports);
747 if (sctp_cmp_addr_exact(addr, &transport->ipaddr)) {
Frank Filz3f7a87d2005-06-20 13:14:57 -0700748 /* Do book keeping for removing the peer and free it. */
749 sctp_assoc_rm_peer(asoc, transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700750 break;
751 }
752 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700753}
754
755/* Lookup a transport by address. */
756struct sctp_transport *sctp_assoc_lookup_paddr(
757 const struct sctp_association *asoc,
758 const union sctp_addr *address)
759{
760 struct sctp_transport *t;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700761
762 /* Cycle through all transports searching for a peer address. */
763
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -0700764 list_for_each_entry(t, &asoc->peer.transport_addr_list,
765 transports) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700766 if (sctp_cmp_addr_exact(address, &t->ipaddr))
767 return t;
768 }
769
770 return NULL;
771}
772
Vlad Yasevich42e30bf2007-12-20 14:08:56 -0800773/* Remove all transports except a give one */
774void sctp_assoc_del_nonprimary_peers(struct sctp_association *asoc,
775 struct sctp_transport *primary)
776{
777 struct sctp_transport *temp;
778 struct sctp_transport *t;
779
780 list_for_each_entry_safe(t, temp, &asoc->peer.transport_addr_list,
781 transports) {
782 /* if the current transport is not the primary one, delete it */
783 if (t != primary)
784 sctp_assoc_rm_peer(asoc, t);
785 }
Vlad Yasevich42e30bf2007-12-20 14:08:56 -0800786}
787
Linus Torvalds1da177e2005-04-16 15:20:36 -0700788/* Engage in transport control operations.
789 * Mark the transport up or down and send a notification to the user.
790 * Select and update the new active and retran paths.
791 */
792void sctp_assoc_control_transport(struct sctp_association *asoc,
793 struct sctp_transport *transport,
794 sctp_transport_cmd_t command,
795 sctp_sn_error_t error)
796{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700797 struct sctp_ulpevent *event;
Al Viro0906e202006-11-20 17:03:01 -0800798 struct sockaddr_storage addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700799 int spc_state = 0;
Neil Horman5aa93bc2012-07-21 07:56:07 +0000800 bool ulp_notify = true;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700801
802 /* Record the transition on the transport. */
803 switch (command) {
804 case SCTP_TRANSPORT_UP:
Vlad Yasevich1ae41142007-03-23 11:32:26 -0700805 /* If we are moving from UNCONFIRMED state due
806 * to heartbeat success, report the SCTP_ADDR_CONFIRMED
807 * state to the user, otherwise report SCTP_ADDR_AVAILABLE.
808 */
809 if (SCTP_UNCONFIRMED == transport->state &&
810 SCTP_HEARTBEAT_SUCCESS == error)
811 spc_state = SCTP_ADDR_CONFIRMED;
812 else
813 spc_state = SCTP_ADDR_AVAILABLE;
Neil Horman5aa93bc2012-07-21 07:56:07 +0000814 /* Don't inform ULP about transition from PF to
Daniel Borkmannac4f9592013-08-09 15:09:08 +0200815 * active state and set cwnd to 1 MTU, see SCTP
Neil Horman5aa93bc2012-07-21 07:56:07 +0000816 * Quick failover draft section 5.1, point 5
817 */
818 if (transport->state == SCTP_PF) {
819 ulp_notify = false;
Daniel Borkmannac4f9592013-08-09 15:09:08 +0200820 transport->cwnd = asoc->pathmtu;
Neil Horman5aa93bc2012-07-21 07:56:07 +0000821 }
Frank Filz3f7a87d2005-06-20 13:14:57 -0700822 transport->state = SCTP_ACTIVE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700823 break;
824
825 case SCTP_TRANSPORT_DOWN:
Vlad Yasevich40187882009-06-23 11:28:05 -0400826 /* If the transport was never confirmed, do not transition it
827 * to inactive state. Also, release the cached route since
828 * there may be a better route next time.
Vlad Yasevichcc756892007-08-24 19:30:25 +0900829 */
830 if (transport->state != SCTP_UNCONFIRMED)
831 transport->state = SCTP_INACTIVE;
Vlad Yasevich40187882009-06-23 11:28:05 -0400832 else {
Julian Anastasovc86a7732017-02-06 23:14:13 +0200833 sctp_transport_dst_release(transport);
zhuyj061079a2014-08-20 17:31:43 +0800834 ulp_notify = false;
Vlad Yasevich40187882009-06-23 11:28:05 -0400835 }
Vlad Yasevichcc756892007-08-24 19:30:25 +0900836
Linus Torvalds1da177e2005-04-16 15:20:36 -0700837 spc_state = SCTP_ADDR_UNREACHABLE;
838 break;
839
Neil Horman5aa93bc2012-07-21 07:56:07 +0000840 case SCTP_TRANSPORT_PF:
841 transport->state = SCTP_PF;
842 ulp_notify = false;
843 break;
844
Linus Torvalds1da177e2005-04-16 15:20:36 -0700845 default:
846 return;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700847 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700848
Daniel Borkmannb82e8f32014-06-11 18:19:29 +0200849 /* Generate and send a SCTP_PEER_ADDR_CHANGE notification
850 * to the user.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700851 */
Neil Horman5aa93bc2012-07-21 07:56:07 +0000852 if (ulp_notify) {
853 memset(&addr, 0, sizeof(struct sockaddr_storage));
854 memcpy(&addr, &transport->ipaddr,
855 transport->af_specific->sockaddr_len);
Daniel Borkmannb82e8f32014-06-11 18:19:29 +0200856
Neil Horman5aa93bc2012-07-21 07:56:07 +0000857 event = sctp_ulpevent_make_peer_addr_change(asoc, &addr,
858 0, spc_state, error, GFP_ATOMIC);
859 if (event)
860 sctp_ulpq_tail_event(&asoc->ulpq, event);
861 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700862
863 /* Select new active and retran paths. */
Daniel Borkmannb82e8f32014-06-11 18:19:29 +0200864 sctp_select_active_and_retran_path(asoc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700865}
866
867/* Hold a reference to an association. */
868void sctp_association_hold(struct sctp_association *asoc)
869{
870 atomic_inc(&asoc->base.refcnt);
871}
872
873/* Release a reference to an association and cleanup
874 * if there are no more references.
875 */
876void sctp_association_put(struct sctp_association *asoc)
877{
878 if (atomic_dec_and_test(&asoc->base.refcnt))
879 sctp_association_destroy(asoc);
880}
881
882/* Allocate the next TSN, Transmission Sequence Number, for the given
883 * association.
884 */
885__u32 sctp_association_get_next_tsn(struct sctp_association *asoc)
886{
887 /* From Section 1.6 Serial Number Arithmetic:
888 * Transmission Sequence Numbers wrap around when they reach
889 * 2**32 - 1. That is, the next TSN a DATA chunk MUST use
890 * after transmitting TSN = 2*32 - 1 is TSN = 0.
891 */
892 __u32 retval = asoc->next_tsn;
893 asoc->next_tsn++;
894 asoc->unack_data++;
895
896 return retval;
897}
898
899/* Compare two addresses to see if they match. Wildcard addresses
900 * only match themselves.
901 */
902int sctp_cmp_addr_exact(const union sctp_addr *ss1,
903 const union sctp_addr *ss2)
904{
905 struct sctp_af *af;
906
907 af = sctp_get_af_specific(ss1->sa.sa_family);
908 if (unlikely(!af))
909 return 0;
910
911 return af->cmp_addr(ss1, ss2);
912}
913
914/* Return an ecne chunk to get prepended to a packet.
915 * Note: We are sly and return a shared, prealloced chunk. FIXME:
916 * No we don't, but we could/should.
917 */
918struct sctp_chunk *sctp_get_ecne_prepend(struct sctp_association *asoc)
919{
wangweidong8b7318d2013-12-06 09:36:28 +0800920 if (!asoc->need_ecne)
921 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700922
923 /* Send ECNE if needed.
924 * Not being able to allocate a chunk here is not deadly.
925 */
wangweidong8b7318d2013-12-06 09:36:28 +0800926 return sctp_make_ecne(asoc, asoc->last_ecne_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700927}
928
929/*
930 * Find which transport this TSN was sent on.
931 */
932struct sctp_transport *sctp_assoc_lookup_tsn(struct sctp_association *asoc,
933 __u32 tsn)
934{
935 struct sctp_transport *active;
936 struct sctp_transport *match;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700937 struct sctp_transport *transport;
938 struct sctp_chunk *chunk;
Al Virodbc16db2006-11-20 17:01:42 -0800939 __be32 key = htonl(tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700940
941 match = NULL;
942
943 /*
944 * FIXME: In general, find a more efficient data structure for
945 * searching.
946 */
947
948 /*
949 * The general strategy is to search each transport's transmitted
950 * list. Return which transport this TSN lives on.
951 *
952 * Let's be hopeful and check the active_path first.
953 * Another optimization would be to know if there is only one
954 * outbound path and not have to look for the TSN at all.
955 *
956 */
957
958 active = asoc->peer.active_path;
959
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -0700960 list_for_each_entry(chunk, &active->transmitted,
961 transmitted_list) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700962
963 if (key == chunk->subh.data_hdr->tsn) {
964 match = active;
965 goto out;
966 }
967 }
968
969 /* If not found, go search all the other transports. */
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -0700970 list_for_each_entry(transport, &asoc->peer.transport_addr_list,
971 transports) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700972
973 if (transport == active)
Xufeng Zhang2317f442013-03-07 21:39:37 +0000974 continue;
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -0700975 list_for_each_entry(chunk, &transport->transmitted,
976 transmitted_list) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700977 if (key == chunk->subh.data_hdr->tsn) {
978 match = transport;
979 goto out;
980 }
981 }
982 }
983out:
984 return match;
985}
986
987/* Is this the association we are looking for? */
988struct sctp_transport *sctp_assoc_is_match(struct sctp_association *asoc,
Eric W. Biederman4110cc22012-08-06 08:41:13 +0000989 struct net *net,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700990 const union sctp_addr *laddr,
991 const union sctp_addr *paddr)
992{
993 struct sctp_transport *transport;
994
Al Viroe2fcced2006-11-20 17:08:41 -0800995 if ((htons(asoc->base.bind_addr.port) == laddr->v4.sin_port) &&
Eric W. Biederman4110cc22012-08-06 08:41:13 +0000996 (htons(asoc->peer.port) == paddr->v4.sin_port) &&
997 net_eq(sock_net(asoc->base.sk), net)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700998 transport = sctp_assoc_lookup_paddr(asoc, paddr);
999 if (!transport)
1000 goto out;
1001
1002 if (sctp_bind_addr_match(&asoc->base.bind_addr, laddr,
1003 sctp_sk(asoc->base.sk)))
1004 goto out;
1005 }
1006 transport = NULL;
1007
1008out:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001009 return transport;
1010}
1011
1012/* Do delayed input processing. This is scheduled by sctp_rcv(). */
David Howellsc4028952006-11-22 14:57:56 +00001013static void sctp_assoc_bh_rcv(struct work_struct *work)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001014{
David Howellsc4028952006-11-22 14:57:56 +00001015 struct sctp_association *asoc =
1016 container_of(work, struct sctp_association,
1017 base.inqueue.immediate);
Eric W. Biederman55e26eb2012-08-07 07:25:24 +00001018 struct net *net = sock_net(asoc->base.sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001019 struct sctp_endpoint *ep;
1020 struct sctp_chunk *chunk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001021 struct sctp_inq *inqueue;
1022 int state;
1023 sctp_subtype_t subtype;
1024 int error = 0;
1025
1026 /* The association should be held so we should be safe. */
1027 ep = asoc->ep;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001028
1029 inqueue = &asoc->base.inqueue;
1030 sctp_association_hold(asoc);
1031 while (NULL != (chunk = sctp_inq_pop(inqueue))) {
1032 state = asoc->state;
1033 subtype = SCTP_ST_CHUNK(chunk->chunk_hdr->type);
1034
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07001035 /* SCTP-AUTH, Section 6.3:
1036 * The receiver has a list of chunk types which it expects
1037 * to be received only after an AUTH-chunk. This list has
1038 * been sent to the peer during the association setup. It
1039 * MUST silently discard these chunks if they are not placed
1040 * after an AUTH chunk in the packet.
1041 */
1042 if (sctp_auth_recv_cid(subtype.chunk, asoc) && !chunk->auth)
1043 continue;
1044
Linus Torvalds1da177e2005-04-16 15:20:36 -07001045 /* Remember where the last DATA chunk came from so we
1046 * know where to send the SACK.
1047 */
1048 if (sctp_chunk_is_data(chunk))
1049 asoc->peer.last_data_from = chunk->transport;
Michele Baldessari196d6752012-12-01 04:49:42 +00001050 else {
Eric W. Biederman55e26eb2012-08-07 07:25:24 +00001051 SCTP_INC_STATS(net, SCTP_MIB_INCTRLCHUNKS);
Michele Baldessari196d6752012-12-01 04:49:42 +00001052 asoc->stats.ictrlchunks++;
1053 if (chunk->chunk_hdr->type == SCTP_CID_SACK)
1054 asoc->stats.isacks++;
1055 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001056
1057 if (chunk->transport)
Daniel Borkmanne5752352014-06-11 18:19:30 +02001058 chunk->transport->last_time_heard = ktime_get();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001059
1060 /* Run through the state machine. */
Eric W. Biederman55e26eb2012-08-07 07:25:24 +00001061 error = sctp_do_sm(net, SCTP_EVENT_T_CHUNK, subtype,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001062 state, ep, asoc, chunk, GFP_ATOMIC);
1063
1064 /* Check to see if the association is freed in response to
1065 * the incoming chunk. If so, get out of the while loop.
1066 */
1067 if (asoc->base.dead)
1068 break;
1069
1070 /* If there is an error on chunk, discard this packet. */
1071 if (error && chunk)
1072 chunk->pdiscard = 1;
1073 }
1074 sctp_association_put(asoc);
1075}
1076
1077/* This routine moves an association from its old sk to a new sk. */
1078void sctp_assoc_migrate(struct sctp_association *assoc, struct sock *newsk)
1079{
1080 struct sctp_sock *newsp = sctp_sk(newsk);
1081 struct sock *oldsk = assoc->base.sk;
1082
1083 /* Delete the association from the old endpoint's list of
1084 * associations.
1085 */
1086 list_del_init(&assoc->asocs);
1087
1088 /* Decrement the backlog value for a TCP-style socket. */
1089 if (sctp_style(oldsk, TCP))
1090 oldsk->sk_ack_backlog--;
1091
1092 /* Release references to the old endpoint and the sock. */
1093 sctp_endpoint_put(assoc->ep);
1094 sock_put(assoc->base.sk);
1095
1096 /* Get a reference to the new endpoint. */
1097 assoc->ep = newsp->ep;
1098 sctp_endpoint_hold(assoc->ep);
1099
1100 /* Get a reference to the new sock. */
1101 assoc->base.sk = newsk;
1102 sock_hold(assoc->base.sk);
1103
1104 /* Add the association to the new endpoint's list of associations. */
1105 sctp_endpoint_add_asoc(newsp->ep, assoc);
1106}
1107
1108/* Update an association (possibly from unexpected COOKIE-ECHO processing). */
1109void sctp_assoc_update(struct sctp_association *asoc,
1110 struct sctp_association *new)
1111{
1112 struct sctp_transport *trans;
1113 struct list_head *pos, *temp;
1114
1115 /* Copy in new parameters of peer. */
1116 asoc->c = new->c;
1117 asoc->peer.rwnd = new->peer.rwnd;
1118 asoc->peer.sack_needed = new->peer.sack_needed;
Daniel Borkmann1be9a952014-07-22 15:22:45 +02001119 asoc->peer.auth_capable = new->peer.auth_capable;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001120 asoc->peer.i = new->peer.i;
Vlad Yasevich8e1ee182008-10-08 14:18:39 -07001121 sctp_tsnmap_init(&asoc->peer.tsn_map, SCTP_TSN_MAP_INITIAL,
1122 asoc->peer.i.initial_tsn, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001123
1124 /* Remove any peer addresses not present in the new association. */
1125 list_for_each_safe(pos, temp, &asoc->peer.transport_addr_list) {
1126 trans = list_entry(pos, struct sctp_transport, transports);
Vlad Yasevich0c427492010-04-28 08:47:19 +00001127 if (!sctp_assoc_lookup_paddr(new, &trans->ipaddr)) {
1128 sctp_assoc_rm_peer(asoc, trans);
1129 continue;
1130 }
Vlad Yasevich749bf922007-03-19 17:02:30 -07001131
1132 if (asoc->state >= SCTP_STATE_ESTABLISHED)
1133 sctp_transport_reset(trans);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001134 }
1135
1136 /* If the case is A (association restart), use
1137 * initial_tsn as next_tsn. If the case is B, use
1138 * current next_tsn in case data sent to peer
1139 * has been discarded and needs retransmission.
1140 */
1141 if (asoc->state >= SCTP_STATE_ESTABLISHED) {
1142 asoc->next_tsn = new->next_tsn;
1143 asoc->ctsn_ack_point = new->ctsn_ack_point;
1144 asoc->adv_peer_ack_point = new->adv_peer_ack_point;
1145
1146 /* Reinitialize SSN for both local streams
1147 * and peer's streams.
1148 */
Xin Longa8386312017-01-06 22:18:33 +08001149 sctp_stream_clear(asoc->stream);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001150
Vlad Yasevich0b58a812007-03-19 17:01:17 -07001151 /* Flush the ULP reassembly and ordered queue.
1152 * Any data there will now be stale and will
1153 * cause problems.
1154 */
1155 sctp_ulpq_flush(&asoc->ulpq);
1156
Vlad Yasevich749bf922007-03-19 17:02:30 -07001157 /* reset the overall association error count so
1158 * that the restarted association doesn't get torn
1159 * down on the next retransmission timer.
1160 */
1161 asoc->overall_error_count = 0;
1162
Linus Torvalds1da177e2005-04-16 15:20:36 -07001163 } else {
1164 /* Add any peer addresses from the new association. */
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -07001165 list_for_each_entry(trans, &new->peer.transport_addr_list,
1166 transports) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001167 if (!sctp_assoc_lookup_paddr(asoc, &trans->ipaddr))
1168 sctp_assoc_add_peer(asoc, &trans->ipaddr,
Sridhar Samudralaad8fec12006-07-21 14:48:50 -07001169 GFP_ATOMIC, trans->state);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001170 }
1171
1172 asoc->ctsn_ack_point = asoc->next_tsn - 1;
1173 asoc->adv_peer_ack_point = asoc->ctsn_ack_point;
Xin Longa8386312017-01-06 22:18:33 +08001174 if (!asoc->stream) {
1175 asoc->stream = new->stream;
1176 new->stream = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001177 }
Vlad Yasevich07d93962007-05-04 13:55:27 -07001178
1179 if (!asoc->assoc_id) {
1180 /* get a new association id since we don't have one
1181 * yet.
1182 */
1183 sctp_assoc_set_id(asoc, GFP_ATOMIC);
1184 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001185 }
Vlad Yasevicha29a5bd2007-09-16 19:31:35 -07001186
wangweidong9d2c8812013-12-06 09:36:30 +08001187 /* SCTP-AUTH: Save the peer parameters from the new associations
Vlad Yasevich730fc3d2007-09-16 19:32:11 -07001188 * and also move the association shared keys over
1189 */
1190 kfree(asoc->peer.peer_random);
1191 asoc->peer.peer_random = new->peer.peer_random;
1192 new->peer.peer_random = NULL;
1193
1194 kfree(asoc->peer.peer_chunks);
1195 asoc->peer.peer_chunks = new->peer.peer_chunks;
1196 new->peer.peer_chunks = NULL;
1197
1198 kfree(asoc->peer.peer_hmacs);
1199 asoc->peer.peer_hmacs = new->peer.peer_hmacs;
1200 new->peer.peer_hmacs = NULL;
1201
Vlad Yasevich730fc3d2007-09-16 19:32:11 -07001202 sctp_auth_asoc_init_active_key(asoc, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001203}
1204
1205/* Update the retran path for sending a retransmitted packet.
Daniel Borkmann4c47af42014-02-20 20:51:06 +01001206 * See also RFC4960, 6.4. Multi-Homed SCTP Endpoints:
1207 *
1208 * When there is outbound data to send and the primary path
1209 * becomes inactive (e.g., due to failures), or where the
1210 * SCTP user explicitly requests to send data to an
1211 * inactive destination transport address, before reporting
1212 * an error to its ULP, the SCTP endpoint should try to send
1213 * the data to an alternate active destination transport
1214 * address if one exists.
1215 *
1216 * When retransmitting data that timed out, if the endpoint
1217 * is multihomed, it should consider each source-destination
1218 * address pair in its retransmission selection policy.
1219 * When retransmitting timed-out data, the endpoint should
1220 * attempt to pick the most divergent source-destination
1221 * pair from the original source-destination pair to which
1222 * the packet was transmitted.
1223 *
1224 * Note: Rules for picking the most divergent source-destination
1225 * pair are an implementation decision and are not specified
1226 * within this document.
1227 *
1228 * Our basic strategy is to round-robin transports in priorities
Denys Vlasenko2103d6b2015-09-28 14:34:04 +02001229 * according to sctp_trans_score() e.g., if no such
Daniel Borkmann4c47af42014-02-20 20:51:06 +01001230 * transport with state SCTP_ACTIVE exists, round-robin through
1231 * SCTP_UNKNOWN, etc. You get the picture.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001232 */
Daniel Borkmann4c47af42014-02-20 20:51:06 +01001233static u8 sctp_trans_score(const struct sctp_transport *trans)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001234{
Denys Vlasenko2103d6b2015-09-28 14:34:04 +02001235 switch (trans->state) {
1236 case SCTP_ACTIVE:
1237 return 3; /* best case */
1238 case SCTP_UNKNOWN:
1239 return 2;
1240 case SCTP_PF:
1241 return 1;
1242 default: /* case SCTP_INACTIVE */
1243 return 0; /* worst case */
1244 }
Frank Filz3f7a87d2005-06-20 13:14:57 -07001245}
1246
Daniel Borkmanna7288c42014-06-11 18:19:31 +02001247static struct sctp_transport *sctp_trans_elect_tie(struct sctp_transport *trans1,
1248 struct sctp_transport *trans2)
1249{
1250 if (trans1->error_count > trans2->error_count) {
1251 return trans2;
1252 } else if (trans1->error_count == trans2->error_count &&
1253 ktime_after(trans2->last_time_heard,
1254 trans1->last_time_heard)) {
1255 return trans2;
1256 } else {
1257 return trans1;
1258 }
1259}
1260
Daniel Borkmann4c47af42014-02-20 20:51:06 +01001261static struct sctp_transport *sctp_trans_elect_best(struct sctp_transport *curr,
1262 struct sctp_transport *best)
1263{
Daniel Borkmanna7288c42014-06-11 18:19:31 +02001264 u8 score_curr, score_best;
1265
Daniel Borkmannea4f19c2014-08-22 13:03:29 +02001266 if (best == NULL || curr == best)
Daniel Borkmann4c47af42014-02-20 20:51:06 +01001267 return curr;
1268
Daniel Borkmanna7288c42014-06-11 18:19:31 +02001269 score_curr = sctp_trans_score(curr);
1270 score_best = sctp_trans_score(best);
1271
1272 /* First, try a score-based selection if both transport states
1273 * differ. If we're in a tie, lets try to make a more clever
1274 * decision here based on error counts and last time heard.
1275 */
1276 if (score_curr > score_best)
1277 return curr;
1278 else if (score_curr == score_best)
Xin Long39d2ade2016-03-10 15:31:57 +08001279 return sctp_trans_elect_tie(best, curr);
Daniel Borkmanna7288c42014-06-11 18:19:31 +02001280 else
1281 return best;
Daniel Borkmann4c47af42014-02-20 20:51:06 +01001282}
1283
1284void sctp_assoc_update_retran_path(struct sctp_association *asoc)
1285{
1286 struct sctp_transport *trans = asoc->peer.retran_path;
1287 struct sctp_transport *trans_next = NULL;
1288
1289 /* We're done as we only have the one and only path. */
1290 if (asoc->peer.transport_count == 1)
1291 return;
1292 /* If active_path and retran_path are the same and active,
1293 * then this is the only active path. Use it.
1294 */
1295 if (asoc->peer.active_path == asoc->peer.retran_path &&
1296 asoc->peer.active_path->state == SCTP_ACTIVE)
1297 return;
1298
1299 /* Iterate from retran_path's successor back to retran_path. */
1300 for (trans = list_next_entry(trans, transports); 1;
1301 trans = list_next_entry(trans, transports)) {
1302 /* Manually skip the head element. */
1303 if (&trans->transports == &asoc->peer.transport_addr_list)
1304 continue;
1305 if (trans->state == SCTP_UNCONFIRMED)
1306 continue;
1307 trans_next = sctp_trans_elect_best(trans, trans_next);
1308 /* Active is good enough for immediate return. */
1309 if (trans_next->state == SCTP_ACTIVE)
1310 break;
1311 /* We've reached the end, time to update path. */
1312 if (trans == asoc->peer.retran_path)
1313 break;
1314 }
1315
Daniel Borkmann433131b2014-03-13 14:45:26 +01001316 asoc->peer.retran_path = trans_next;
Daniel Borkmann4c47af42014-02-20 20:51:06 +01001317
1318 pr_debug("%s: association:%p updated new path to addr:%pISpc\n",
1319 __func__, asoc, &asoc->peer.retran_path->ipaddr.sa);
1320}
1321
Daniel Borkmannb82e8f32014-06-11 18:19:29 +02001322static void sctp_select_active_and_retran_path(struct sctp_association *asoc)
1323{
1324 struct sctp_transport *trans, *trans_pri = NULL, *trans_sec = NULL;
Daniel Borkmanna7288c42014-06-11 18:19:31 +02001325 struct sctp_transport *trans_pf = NULL;
Daniel Borkmannb82e8f32014-06-11 18:19:29 +02001326
1327 /* Look for the two most recently used active transports. */
1328 list_for_each_entry(trans, &asoc->peer.transport_addr_list,
1329 transports) {
Daniel Borkmanna7288c42014-06-11 18:19:31 +02001330 /* Skip uninteresting transports. */
Daniel Borkmannb82e8f32014-06-11 18:19:29 +02001331 if (trans->state == SCTP_INACTIVE ||
Daniel Borkmanna7288c42014-06-11 18:19:31 +02001332 trans->state == SCTP_UNCONFIRMED)
Daniel Borkmannb82e8f32014-06-11 18:19:29 +02001333 continue;
Daniel Borkmanna7288c42014-06-11 18:19:31 +02001334 /* Keep track of the best PF transport from our
1335 * list in case we don't find an active one.
1336 */
1337 if (trans->state == SCTP_PF) {
1338 trans_pf = sctp_trans_elect_best(trans, trans_pf);
1339 continue;
1340 }
1341 /* For active transports, pick the most recent ones. */
Daniel Borkmannb82e8f32014-06-11 18:19:29 +02001342 if (trans_pri == NULL ||
Daniel Borkmanne5752352014-06-11 18:19:30 +02001343 ktime_after(trans->last_time_heard,
1344 trans_pri->last_time_heard)) {
Daniel Borkmannb82e8f32014-06-11 18:19:29 +02001345 trans_sec = trans_pri;
1346 trans_pri = trans;
1347 } else if (trans_sec == NULL ||
Daniel Borkmanne5752352014-06-11 18:19:30 +02001348 ktime_after(trans->last_time_heard,
1349 trans_sec->last_time_heard)) {
Daniel Borkmannb82e8f32014-06-11 18:19:29 +02001350 trans_sec = trans;
1351 }
1352 }
1353
1354 /* RFC 2960 6.4 Multi-Homed SCTP Endpoints
1355 *
1356 * By default, an endpoint should always transmit to the primary
1357 * path, unless the SCTP user explicitly specifies the
1358 * destination transport address (and possibly source transport
1359 * address) to use. [If the primary is active but not most recent,
1360 * bump the most recently used transport.]
1361 */
1362 if ((asoc->peer.primary_path->state == SCTP_ACTIVE ||
1363 asoc->peer.primary_path->state == SCTP_UNKNOWN) &&
1364 asoc->peer.primary_path != trans_pri) {
1365 trans_sec = trans_pri;
1366 trans_pri = asoc->peer.primary_path;
1367 }
1368
1369 /* We did not find anything useful for a possible retransmission
1370 * path; either primary path that we found is the the same as
1371 * the current one, or we didn't generally find an active one.
1372 */
1373 if (trans_sec == NULL)
1374 trans_sec = trans_pri;
1375
1376 /* If we failed to find a usable transport, just camp on the
Daniel Borkmannaa4a83e2014-08-22 13:03:30 +02001377 * active or pick a PF iff it's the better choice.
Daniel Borkmannb82e8f32014-06-11 18:19:29 +02001378 */
1379 if (trans_pri == NULL) {
Daniel Borkmannaa4a83e2014-08-22 13:03:30 +02001380 trans_pri = sctp_trans_elect_best(asoc->peer.active_path, trans_pf);
1381 trans_sec = trans_pri;
Daniel Borkmannb82e8f32014-06-11 18:19:29 +02001382 }
1383
1384 /* Set the active and retran transports. */
1385 asoc->peer.active_path = trans_pri;
1386 asoc->peer.retran_path = trans_sec;
1387}
1388
Daniel Borkmann4c47af42014-02-20 20:51:06 +01001389struct sctp_transport *
1390sctp_assoc_choose_alter_transport(struct sctp_association *asoc,
1391 struct sctp_transport *last_sent_to)
Frank Filz3f7a87d2005-06-20 13:14:57 -07001392{
Wei Yongjun9919b452009-05-12 21:52:51 +08001393 /* If this is the first time packet is sent, use the active path,
1394 * else use the retran path. If the last packet was sent over the
Frank Filz3f7a87d2005-06-20 13:14:57 -07001395 * retran path, update the retran path and use it.
1396 */
Daniel Borkmann4c47af42014-02-20 20:51:06 +01001397 if (last_sent_to == NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001398 return asoc->peer.active_path;
Daniel Borkmann4c47af42014-02-20 20:51:06 +01001399 } else {
Wei Yongjun9919b452009-05-12 21:52:51 +08001400 if (last_sent_to == asoc->peer.retran_path)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001401 sctp_assoc_update_retran_path(asoc);
Daniel Borkmann4c47af42014-02-20 20:51:06 +01001402
Linus Torvalds1da177e2005-04-16 15:20:36 -07001403 return asoc->peer.retran_path;
1404 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001405}
1406
1407/* Update the association's pmtu and frag_point by going through all the
1408 * transports. This routine is called when a transport's PMTU has changed.
1409 */
David S. Miller02f3d4c2012-07-16 03:57:14 -07001410void sctp_assoc_sync_pmtu(struct sock *sk, struct sctp_association *asoc)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001411{
1412 struct sctp_transport *t;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001413 __u32 pmtu = 0;
1414
1415 if (!asoc)
1416 return;
1417
1418 /* Get the lowest pmtu of all the transports. */
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -07001419 list_for_each_entry(t, &asoc->peer.transport_addr_list,
1420 transports) {
Vlad Yasevich8a479492007-06-07 14:21:05 -04001421 if (t->pmtu_pending && t->dst) {
Marcelo Ricardo Leitner3822a5f2016-03-19 12:17:20 -03001422 sctp_transport_update_pmtu(sk, t,
Marcelo Ricardo Leitnere2f036a2016-09-21 08:45:55 -03001423 SCTP_TRUNC4(dst_mtu(t->dst)));
Vlad Yasevich8a479492007-06-07 14:21:05 -04001424 t->pmtu_pending = 0;
1425 }
Frank Filz52ccb8e2005-12-22 11:36:46 -08001426 if (!pmtu || (t->pathmtu < pmtu))
1427 pmtu = t->pathmtu;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001428 }
1429
1430 if (pmtu) {
Frank Filz52ccb8e2005-12-22 11:36:46 -08001431 asoc->pathmtu = pmtu;
Vlad Yasevichf68b2e02009-09-04 18:21:00 -04001432 asoc->frag_point = sctp_frag_point(asoc, pmtu);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001433 }
1434
Daniel Borkmannbb333812013-06-28 19:49:40 +02001435 pr_debug("%s: asoc:%p, pmtu:%d, frag_point:%d\n", __func__, asoc,
1436 asoc->pathmtu, asoc->frag_point);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001437}
1438
1439/* Should we send a SACK to update our peer? */
wangweidongce4a03d2013-12-06 09:36:29 +08001440static inline bool sctp_peer_needs_update(struct sctp_association *asoc)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001441{
Eric W. Biedermane1fc3b12012-08-07 07:29:57 +00001442 struct net *net = sock_net(asoc->base.sk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001443 switch (asoc->state) {
1444 case SCTP_STATE_ESTABLISHED:
1445 case SCTP_STATE_SHUTDOWN_PENDING:
1446 case SCTP_STATE_SHUTDOWN_RECEIVED:
1447 case SCTP_STATE_SHUTDOWN_SENT:
1448 if ((asoc->rwnd > asoc->a_rwnd) &&
Vlad Yasevich90f2f532009-11-23 15:53:57 -05001449 ((asoc->rwnd - asoc->a_rwnd) >= max_t(__u32,
Eric W. Biedermane1fc3b12012-08-07 07:29:57 +00001450 (asoc->base.sk->sk_rcvbuf >> net->sctp.rwnd_upd_shift),
Vlad Yasevich90f2f532009-11-23 15:53:57 -05001451 asoc->pathmtu)))
wangweidongce4a03d2013-12-06 09:36:29 +08001452 return true;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001453 break;
1454 default:
1455 break;
1456 }
wangweidongce4a03d2013-12-06 09:36:29 +08001457 return false;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001458}
1459
Daniel Borkmann362d5202014-04-14 21:45:17 +02001460/* Increase asoc's rwnd by len and send any window update SACK if needed. */
1461void sctp_assoc_rwnd_increase(struct sctp_association *asoc, unsigned int len)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001462{
1463 struct sctp_chunk *sack;
1464 struct timer_list *timer;
1465
Daniel Borkmann362d5202014-04-14 21:45:17 +02001466 if (asoc->rwnd_over) {
1467 if (asoc->rwnd_over >= len) {
1468 asoc->rwnd_over -= len;
1469 } else {
1470 asoc->rwnd += (len - asoc->rwnd_over);
1471 asoc->rwnd_over = 0;
1472 }
1473 } else {
1474 asoc->rwnd += len;
1475 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001476
Daniel Borkmann362d5202014-04-14 21:45:17 +02001477 /* If we had window pressure, start recovering it
1478 * once our rwnd had reached the accumulated pressure
1479 * threshold. The idea is to recover slowly, but up
1480 * to the initial advertised window.
1481 */
Marcelo Ricardo Leitner16360982016-12-23 14:29:37 -02001482 if (asoc->rwnd_press) {
Daniel Borkmann362d5202014-04-14 21:45:17 +02001483 int change = min(asoc->pathmtu, asoc->rwnd_press);
1484 asoc->rwnd += change;
1485 asoc->rwnd_press -= change;
1486 }
Vlad Yasevich4d3c46e2009-09-04 18:20:59 -04001487
Daniel Borkmann362d5202014-04-14 21:45:17 +02001488 pr_debug("%s: asoc:%p rwnd increased by %d to (%u, %u) - %u\n",
1489 __func__, asoc, len, asoc->rwnd, asoc->rwnd_over,
1490 asoc->a_rwnd);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001491
1492 /* Send a window update SACK if the rwnd has increased by at least the
1493 * minimum of the association's PMTU and half of the receive buffer.
1494 * The algorithm used is similar to the one described in
1495 * Section 4.2.3.3 of RFC 1122.
1496 */
Daniel Borkmann362d5202014-04-14 21:45:17 +02001497 if (sctp_peer_needs_update(asoc)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001498 asoc->a_rwnd = asoc->rwnd;
Daniel Borkmannbb333812013-06-28 19:49:40 +02001499
1500 pr_debug("%s: sending window update SACK- asoc:%p rwnd:%u "
1501 "a_rwnd:%u\n", __func__, asoc, asoc->rwnd,
1502 asoc->a_rwnd);
1503
Linus Torvalds1da177e2005-04-16 15:20:36 -07001504 sack = sctp_make_sack(asoc);
1505 if (!sack)
1506 return;
1507
1508 asoc->peer.sack_needed = 0;
1509
Marcelo Ricardo Leitnercea87682016-03-10 18:33:07 -03001510 sctp_outq_tail(&asoc->outqueue, sack, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001511
1512 /* Stop the SACK timer. */
1513 timer = &asoc->timers[SCTP_EVENT_TIMEOUT_SACK];
Ying Xue25cc4ae2013-02-03 20:32:57 +00001514 if (del_timer(timer))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001515 sctp_association_put(asoc);
1516 }
1517}
1518
Daniel Borkmann362d5202014-04-14 21:45:17 +02001519/* Decrease asoc's rwnd by len. */
1520void sctp_assoc_rwnd_decrease(struct sctp_association *asoc, unsigned int len)
1521{
1522 int rx_count;
1523 int over = 0;
1524
1525 if (unlikely(!asoc->rwnd || asoc->rwnd_over))
1526 pr_debug("%s: association:%p has asoc->rwnd:%u, "
1527 "asoc->rwnd_over:%u!\n", __func__, asoc,
1528 asoc->rwnd, asoc->rwnd_over);
1529
1530 if (asoc->ep->rcvbuf_policy)
1531 rx_count = atomic_read(&asoc->rmem_alloc);
1532 else
1533 rx_count = atomic_read(&asoc->base.sk->sk_rmem_alloc);
1534
1535 /* If we've reached or overflowed our receive buffer, announce
1536 * a 0 rwnd if rwnd would still be positive. Store the
1537 * the potential pressure overflow so that the window can be restored
1538 * back to original value.
1539 */
1540 if (rx_count >= asoc->base.sk->sk_rcvbuf)
1541 over = 1;
1542
1543 if (asoc->rwnd >= len) {
1544 asoc->rwnd -= len;
1545 if (over) {
1546 asoc->rwnd_press += asoc->rwnd;
1547 asoc->rwnd = 0;
1548 }
1549 } else {
Marcelo Ricardo Leitner58b94d82016-12-23 14:29:02 -02001550 asoc->rwnd_over += len - asoc->rwnd;
Daniel Borkmann362d5202014-04-14 21:45:17 +02001551 asoc->rwnd = 0;
1552 }
1553
1554 pr_debug("%s: asoc:%p rwnd decreased by %d to (%u, %u, %u)\n",
1555 __func__, asoc, len, asoc->rwnd, asoc->rwnd_over,
1556 asoc->rwnd_press);
1557}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001558
1559/* Build the bind address list for the association based on info from the
1560 * local endpoint and the remote peer.
1561 */
Alexey Dobriyan3182cd82005-07-11 20:57:47 -07001562int sctp_assoc_set_bind_addr_from_ep(struct sctp_association *asoc,
Vlad Yasevich409b95a2009-11-10 08:57:34 +00001563 sctp_scope_t scope, gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001564{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001565 int flags;
1566
1567 /* Use scoping rules to determine the subset of addresses from
1568 * the endpoint.
1569 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001570 flags = (PF_INET6 == asoc->base.sk->sk_family) ? SCTP_ADDR6_ALLOWED : 0;
1571 if (asoc->peer.ipv4_address)
1572 flags |= SCTP_ADDR4_PEERSUPP;
1573 if (asoc->peer.ipv6_address)
1574 flags |= SCTP_ADDR6_PEERSUPP;
1575
Eric W. Biederman4db67e82012-08-06 08:42:04 +00001576 return sctp_bind_addr_copy(sock_net(asoc->base.sk),
1577 &asoc->base.bind_addr,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001578 &asoc->ep->base.bind_addr,
1579 scope, gfp, flags);
1580}
1581
1582/* Build the association's bind address list from the cookie. */
1583int sctp_assoc_set_bind_addr_from_cookie(struct sctp_association *asoc,
Alexey Dobriyan3182cd82005-07-11 20:57:47 -07001584 struct sctp_cookie *cookie,
Al Virodd0fc662005-10-07 07:46:04 +01001585 gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001586{
1587 int var_size2 = ntohs(cookie->peer_init->chunk_hdr.length);
1588 int var_size3 = cookie->raw_addr_list_len;
1589 __u8 *raw = (__u8 *)cookie->peer_init + var_size2;
1590
1591 return sctp_raw_to_bind_addrs(&asoc->base.bind_addr, raw, var_size3,
1592 asoc->ep->base.bind_addr.port, gfp);
1593}
1594
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001595/* Lookup laddr in the bind address list of an association. */
1596int sctp_assoc_lookup_laddr(struct sctp_association *asoc,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001597 const union sctp_addr *laddr)
1598{
Vlad Yasevich559cf712007-09-16 16:03:28 -07001599 int found = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001600
Linus Torvalds1da177e2005-04-16 15:20:36 -07001601 if ((asoc->base.bind_addr.port == ntohs(laddr->v4.sin_port)) &&
1602 sctp_bind_addr_match(&asoc->base.bind_addr, laddr,
Vlad Yasevich559cf712007-09-16 16:03:28 -07001603 sctp_sk(asoc->base.sk)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001604 found = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001605
Linus Torvalds1da177e2005-04-16 15:20:36 -07001606 return found;
1607}
Vlad Yasevich07d93962007-05-04 13:55:27 -07001608
1609/* Set an association id for a given association */
1610int sctp_assoc_set_id(struct sctp_association *asoc, gfp_t gfp)
1611{
Mel Gormand0164ad2015-11-06 16:28:21 -08001612 bool preload = gfpflags_allow_blocking(gfp);
Tejun Heo94960e82013-02-27 17:05:00 -08001613 int ret;
Vlad Yasevichc6ba68a2009-06-01 12:41:15 -04001614
1615 /* If the id is already assigned, keep it. */
1616 if (asoc->assoc_id)
Tejun Heo94960e82013-02-27 17:05:00 -08001617 return 0;
Vlad Yasevich07d93962007-05-04 13:55:27 -07001618
Tejun Heo94960e82013-02-27 17:05:00 -08001619 if (preload)
1620 idr_preload(gfp);
Vlad Yasevich07d93962007-05-04 13:55:27 -07001621 spin_lock_bh(&sctp_assocs_id_lock);
Jeff Layton713e00a2013-04-29 16:21:22 -07001622 /* 0 is not a valid assoc_id, must be >= 1 */
1623 ret = idr_alloc_cyclic(&sctp_assocs_id, asoc, 1, 0, GFP_NOWAIT);
Vlad Yasevich07d93962007-05-04 13:55:27 -07001624 spin_unlock_bh(&sctp_assocs_id_lock);
Tejun Heo94960e82013-02-27 17:05:00 -08001625 if (preload)
1626 idr_preload_end();
1627 if (ret < 0)
1628 return ret;
Vlad Yasevich07d93962007-05-04 13:55:27 -07001629
Tejun Heo94960e82013-02-27 17:05:00 -08001630 asoc->assoc_id = (sctp_assoc_t)ret;
1631 return 0;
Vlad Yasevich07d93962007-05-04 13:55:27 -07001632}
Vlad Yasevicha08de642007-12-20 14:11:47 -08001633
Wei Yongjun8b4472c2011-05-24 21:48:02 +00001634/* Free the ASCONF queue */
1635static void sctp_assoc_free_asconf_queue(struct sctp_association *asoc)
1636{
1637 struct sctp_chunk *asconf;
1638 struct sctp_chunk *tmp;
1639
1640 list_for_each_entry_safe(asconf, tmp, &asoc->addip_chunk_list, list) {
1641 list_del_init(&asconf->list);
1642 sctp_chunk_free(asconf);
1643 }
1644}
1645
Vlad Yasevicha08de642007-12-20 14:11:47 -08001646/* Free asconf_ack cache */
1647static void sctp_assoc_free_asconf_acks(struct sctp_association *asoc)
1648{
1649 struct sctp_chunk *ack;
1650 struct sctp_chunk *tmp;
1651
1652 list_for_each_entry_safe(ack, tmp, &asoc->asconf_ack_list,
1653 transmitted_list) {
1654 list_del_init(&ack->transmitted_list);
1655 sctp_chunk_free(ack);
1656 }
1657}
1658
1659/* Clean up the ASCONF_ACK queue */
1660void sctp_assoc_clean_asconf_ack_cache(const struct sctp_association *asoc)
1661{
1662 struct sctp_chunk *ack;
1663 struct sctp_chunk *tmp;
1664
Lucas De Marchi25985ed2011-03-30 22:57:33 -03001665 /* We can remove all the entries from the queue up to
Vlad Yasevicha08de642007-12-20 14:11:47 -08001666 * the "Peer-Sequence-Number".
1667 */
1668 list_for_each_entry_safe(ack, tmp, &asoc->asconf_ack_list,
1669 transmitted_list) {
1670 if (ack->subh.addip_hdr->serial ==
1671 htonl(asoc->peer.addip_serial))
1672 break;
1673
1674 list_del_init(&ack->transmitted_list);
1675 sctp_chunk_free(ack);
1676 }
1677}
1678
1679/* Find the ASCONF_ACK whose serial number matches ASCONF */
1680struct sctp_chunk *sctp_assoc_lookup_asconf_ack(
1681 const struct sctp_association *asoc,
1682 __be32 serial)
1683{
Wei Yongjuna8699812008-02-05 23:35:04 +09001684 struct sctp_chunk *ack;
Vlad Yasevicha08de642007-12-20 14:11:47 -08001685
1686 /* Walk through the list of cached ASCONF-ACKs and find the
1687 * ack chunk whose serial number matches that of the request.
1688 */
1689 list_for_each_entry(ack, &asoc->asconf_ack_list, transmitted_list) {
Daniel Borkmannb69040d2014-10-09 22:55:32 +02001690 if (sctp_chunk_pending(ack))
1691 continue;
Vlad Yasevicha08de642007-12-20 14:11:47 -08001692 if (ack->subh.addip_hdr->serial == serial) {
1693 sctp_chunk_hold(ack);
Wei Yongjuna8699812008-02-05 23:35:04 +09001694 return ack;
Vlad Yasevicha08de642007-12-20 14:11:47 -08001695 }
1696 }
1697
Wei Yongjuna8699812008-02-05 23:35:04 +09001698 return NULL;
Vlad Yasevicha08de642007-12-20 14:11:47 -08001699}
Wei Yongjuna000c012011-05-29 23:23:36 +00001700
1701void sctp_asconf_queue_teardown(struct sctp_association *asoc)
1702{
1703 /* Free any cached ASCONF_ACK chunk. */
1704 sctp_assoc_free_asconf_acks(asoc);
1705
1706 /* Free the ASCONF queue. */
1707 sctp_assoc_free_asconf_queue(asoc);
1708
1709 /* Free any cached ASCONF chunk. */
1710 if (asoc->addip_last_asconf)
1711 sctp_chunk_free(asoc->addip_last_asconf);
1712}