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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) 2001-2002 Intel Corp.
6 * Copyright (c) 2002 Nokia Corp.
7 *
Vlad Yasevich60c778b2008-01-11 09:57:09 -05008 * This is part of the SCTP Linux Kernel Implementation.
Linus Torvalds1da177e2005-04-16 15:20:36 -07009 *
10 * These are the state functions for the state machine.
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 * Mathew Kotowsky <kotowsky@sctp.org>
36 * Sridhar Samudrala <samudrala@us.ibm.com>
37 * Jon Grimm <jgrimm@us.ibm.com>
38 * Hui Huang <hui.huang@nokia.com>
39 * Dajiang Zhang <dajiang.zhang@nokia.com>
40 * Daisy Chang <daisyc@us.ibm.com>
41 * Ardelle Fan <ardelle.fan@intel.com>
42 * Ryan Layer <rmlayer@us.ibm.com>
43 * Kevin Gao <kevin.gao@intel.com>
Linus Torvalds1da177e2005-04-16 15:20:36 -070044 */
45
Joe Perches145ce502010-08-24 13:21:08 +000046#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
47
Linus Torvalds1da177e2005-04-16 15:20:36 -070048#include <linux/types.h>
49#include <linux/kernel.h>
50#include <linux/ip.h>
51#include <linux/ipv6.h>
52#include <linux/net.h>
53#include <linux/inet.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090054#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070055#include <net/sock.h>
56#include <net/inet_ecn.h>
57#include <linux/skbuff.h>
58#include <net/sctp/sctp.h>
59#include <net/sctp/sm.h>
60#include <net/sctp/structs.h>
61
Eric W. Biederman24cb81a2012-08-07 07:28:09 +000062static struct sctp_packet *sctp_abort_pkt_new(struct net *net,
63 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -070064 const struct sctp_association *asoc,
65 struct sctp_chunk *chunk,
66 const void *payload,
67 size_t paylen);
68static int sctp_eat_data(const struct sctp_association *asoc,
69 struct sctp_chunk *chunk,
70 sctp_cmd_seq_t *commands);
Eric W. Biederman2ce95502012-08-06 08:43:06 +000071static struct sctp_packet *sctp_ootb_pkt_new(struct net *net,
72 const struct sctp_association *asoc,
Linus Torvalds1da177e2005-04-16 15:20:36 -070073 const struct sctp_chunk *chunk);
Eric W. Biederman24cb81a2012-08-07 07:28:09 +000074static void sctp_send_stale_cookie_err(struct net *net,
75 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -070076 const struct sctp_association *asoc,
77 const struct sctp_chunk *chunk,
78 sctp_cmd_seq_t *commands,
79 struct sctp_chunk *err_chunk);
Eric W. Biederman24cb81a2012-08-07 07:28:09 +000080static sctp_disposition_t sctp_sf_do_5_2_6_stale(struct net *net,
81 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -070082 const struct sctp_association *asoc,
83 const sctp_subtype_t type,
84 void *arg,
85 sctp_cmd_seq_t *commands);
Eric W. Biederman24cb81a2012-08-07 07:28:09 +000086static sctp_disposition_t sctp_sf_shut_8_4_5(struct net *net,
87 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -070088 const struct sctp_association *asoc,
89 const sctp_subtype_t type,
90 void *arg,
91 sctp_cmd_seq_t *commands);
Eric W. Biederman24cb81a2012-08-07 07:28:09 +000092static sctp_disposition_t sctp_sf_tabort_8_4_8(struct net *net,
93 const struct sctp_endpoint *ep,
Vlad Yasevichece25df2007-09-07 16:30:54 -040094 const struct sctp_association *asoc,
95 const sctp_subtype_t type,
96 void *arg,
97 sctp_cmd_seq_t *commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -070098static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk);
99
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000100static sctp_disposition_t sctp_stop_t1_and_abort(struct net *net,
101 sctp_cmd_seq_t *commands,
Al Virof94c0192006-11-20 17:00:25 -0800102 __be16 error, int sk_err,
Adrian Bunk52c1da32005-06-23 22:05:33 -0700103 const struct sctp_association *asoc,
104 struct sctp_transport *transport);
105
Wei Yongjunaecedea2007-08-02 16:57:44 +0800106static sctp_disposition_t sctp_sf_abort_violation(
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000107 struct net *net,
Vlad Yasevichece25df2007-09-07 16:30:54 -0400108 const struct sctp_endpoint *ep,
Wei Yongjunaecedea2007-08-02 16:57:44 +0800109 const struct sctp_association *asoc,
110 void *arg,
111 sctp_cmd_seq_t *commands,
112 const __u8 *payload,
113 const size_t paylen);
114
Adrian Bunk52c1da32005-06-23 22:05:33 -0700115static sctp_disposition_t sctp_sf_violation_chunklen(
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000116 struct net *net,
Adrian Bunk52c1da32005-06-23 22:05:33 -0700117 const struct sctp_endpoint *ep,
118 const struct sctp_association *asoc,
119 const sctp_subtype_t type,
120 void *arg,
121 sctp_cmd_seq_t *commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122
Wei Yongjun6f4c6182007-09-19 17:19:52 +0800123static sctp_disposition_t sctp_sf_violation_paramlen(
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000124 struct net *net,
Wei Yongjun6f4c6182007-09-19 17:19:52 +0800125 const struct sctp_endpoint *ep,
126 const struct sctp_association *asoc,
127 const sctp_subtype_t type,
Wei Yongjunba016672008-09-30 05:32:24 -0700128 void *arg, void *ext,
Wei Yongjun6f4c6182007-09-19 17:19:52 +0800129 sctp_cmd_seq_t *commands);
130
Wei Yongjunaecedea2007-08-02 16:57:44 +0800131static sctp_disposition_t sctp_sf_violation_ctsn(
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000132 struct net *net,
Wei Yongjunaecedea2007-08-02 16:57:44 +0800133 const struct sctp_endpoint *ep,
134 const struct sctp_association *asoc,
135 const sctp_subtype_t type,
136 void *arg,
137 sctp_cmd_seq_t *commands);
138
Vlad Yasevichece25df2007-09-07 16:30:54 -0400139static sctp_disposition_t sctp_sf_violation_chunk(
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000140 struct net *net,
Vlad Yasevichece25df2007-09-07 16:30:54 -0400141 const struct sctp_endpoint *ep,
142 const struct sctp_association *asoc,
143 const sctp_subtype_t type,
144 void *arg,
145 sctp_cmd_seq_t *commands);
146
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000147static sctp_ierror_t sctp_sf_authenticate(struct net *net,
148 const struct sctp_endpoint *ep,
Vlad Yasevichbbd0d592007-10-03 17:51:34 -0700149 const struct sctp_association *asoc,
150 const sctp_subtype_t type,
151 struct sctp_chunk *chunk);
152
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000153static sctp_disposition_t __sctp_sf_do_9_1_abort(struct net *net,
154 const struct sctp_endpoint *ep,
Vlad Yasevich75205f42007-12-20 14:12:59 -0800155 const struct sctp_association *asoc,
156 const sctp_subtype_t type,
157 void *arg,
158 sctp_cmd_seq_t *commands);
159
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160/* Small helper function that checks if the chunk length
161 * is of the appropriate length. The 'required_length' argument
162 * is set to be the size of a specific chunk we are testing.
163 * Return Values: 1 = Valid length
164 * 0 = Invalid length
165 *
166 */
167static inline int
168sctp_chunk_length_valid(struct sctp_chunk *chunk,
169 __u16 required_length)
170{
171 __u16 chunk_length = ntohs(chunk->chunk_hdr->length);
172
173 if (unlikely(chunk_length < required_length))
174 return 0;
175
176 return 1;
177}
178
179/**********************************************************
180 * These are the state functions for handling chunk events.
181 **********************************************************/
182
183/*
184 * Process the final SHUTDOWN COMPLETE.
185 *
186 * Section: 4 (C) (diagram), 9.2
187 * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify
188 * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be
189 * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint
190 * should stop the T2-shutdown timer and remove all knowledge of the
191 * association (and thus the association enters the CLOSED state).
192 *
Jerome Forissier047a2422005-04-28 11:58:43 -0700193 * Verification Tag: 8.5.1(C), sctpimpguide 2.41.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 * C) Rules for packet carrying SHUTDOWN COMPLETE:
195 * ...
Jerome Forissier047a2422005-04-28 11:58:43 -0700196 * - The receiver of a SHUTDOWN COMPLETE shall accept the packet
197 * if the Verification Tag field of the packet matches its own tag and
198 * the T bit is not set
199 * OR
200 * it is set to its peer's tag and the T bit is set in the Chunk
201 * Flags.
202 * Otherwise, the receiver MUST silently discard the packet
203 * and take no further action. An endpoint MUST ignore the
204 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205 *
206 * Inputs
207 * (endpoint, asoc, chunk)
208 *
209 * Outputs
210 * (asoc, reply_msg, msg_up, timers, counters)
211 *
212 * The return value is the disposition of the chunk.
213 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000214sctp_disposition_t sctp_sf_do_4_C(struct net *net,
215 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 const struct sctp_association *asoc,
217 const sctp_subtype_t type,
218 void *arg,
219 sctp_cmd_seq_t *commands)
220{
221 struct sctp_chunk *chunk = arg;
222 struct sctp_ulpevent *ev;
223
Vlad Yasevichece25df2007-09-07 16:30:54 -0400224 if (!sctp_vtag_verify_either(chunk, asoc))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000225 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Vlad Yasevichece25df2007-09-07 16:30:54 -0400226
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 /* RFC 2960 6.10 Bundling
228 *
229 * An endpoint MUST NOT bundle INIT, INIT ACK or
230 * SHUTDOWN COMPLETE with any other chunks.
231 */
232 if (!chunk->singleton)
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000233 return sctp_sf_violation_chunk(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234
Vlad Yasevichece25df2007-09-07 16:30:54 -0400235 /* Make sure that the SHUTDOWN_COMPLETE chunk has a valid length. */
236 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000237 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
Vlad Yasevichece25df2007-09-07 16:30:54 -0400238 commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239
240 /* RFC 2960 10.2 SCTP-to-ULP
241 *
242 * H) SHUTDOWN COMPLETE notification
243 *
244 * When SCTP completes the shutdown procedures (section 9.2) this
245 * notification is passed to the upper layer.
246 */
247 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
Vlad Yasevicha5a35e72007-03-23 11:34:08 -0700248 0, 0, 0, NULL, GFP_ATOMIC);
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700249 if (ev)
250 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900251 SCTP_ULPEVENT(ev));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252
253 /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint
254 * will verify that it is in SHUTDOWN-ACK-SENT state, if it is
255 * not the chunk should be discarded. If the endpoint is in
256 * the SHUTDOWN-ACK-SENT state the endpoint should stop the
257 * T2-shutdown timer and remove all knowledge of the
258 * association (and thus the association enters the CLOSED
259 * state).
260 */
261 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
262 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
263
264 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
265 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
266
267 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
268 SCTP_STATE(SCTP_STATE_CLOSED));
269
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000270 SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS);
271 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272
273 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
274
275 return SCTP_DISPOSITION_DELETE_TCB;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276}
277
278/*
279 * Respond to a normal INIT chunk.
280 * We are the side that is being asked for an association.
281 *
282 * Section: 5.1 Normal Establishment of an Association, B
283 * B) "Z" shall respond immediately with an INIT ACK chunk. The
284 * destination IP address of the INIT ACK MUST be set to the source
285 * IP address of the INIT to which this INIT ACK is responding. In
286 * the response, besides filling in other parameters, "Z" must set the
287 * Verification Tag field to Tag_A, and also provide its own
288 * Verification Tag (Tag_Z) in the Initiate Tag field.
289 *
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900290 * Verification Tag: Must be 0.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291 *
292 * Inputs
293 * (endpoint, asoc, chunk)
294 *
295 * Outputs
296 * (asoc, reply_msg, msg_up, timers, counters)
297 *
298 * The return value is the disposition of the chunk.
299 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000300sctp_disposition_t sctp_sf_do_5_1B_init(struct net *net,
301 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302 const struct sctp_association *asoc,
303 const sctp_subtype_t type,
304 void *arg,
305 sctp_cmd_seq_t *commands)
306{
307 struct sctp_chunk *chunk = arg;
308 struct sctp_chunk *repl;
309 struct sctp_association *new_asoc;
310 struct sctp_chunk *err_chunk;
311 struct sctp_packet *packet;
312 sctp_unrecognized_param_t *unk_param;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700313 int len;
314
315 /* 6.10 Bundling
316 * An endpoint MUST NOT bundle INIT, INIT ACK or
317 * SHUTDOWN COMPLETE with any other chunks.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900318 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319 * IG Section 2.11.2
320 * Furthermore, we require that the receiver of an INIT chunk MUST
321 * enforce these rules by silently discarding an arriving packet
322 * with an INIT chunk that is bundled with other chunks.
323 */
324 if (!chunk->singleton)
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000325 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700326
327 /* If the packet is an OOTB packet which is temporarily on the
328 * control endpoint, respond with an ABORT.
329 */
Eric W. Biederman2ce95502012-08-06 08:43:06 +0000330 if (ep == sctp_sk(net->sctp.ctl_sock)->ep) {
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000331 SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000332 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
Wei Yongjun8190f892008-09-08 12:13:55 +0800333 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900336 * Tag.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337 */
338 if (chunk->sctp_hdr->vtag != 0)
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000339 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340
341 /* Make sure that the INIT chunk has a valid length.
342 * Normally, this would cause an ABORT with a Protocol Violation
343 * error, but since we don't have an association, we'll
344 * just discard the packet.
345 */
346 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000347 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348
Vlad Yasevichbec96402009-07-30 18:08:28 -0400349 /* If the INIT is coming toward a closing socket, we'll send back
350 * and ABORT. Essentially, this catches the race of INIT being
351 * backloged to the socket at the same time as the user isses close().
352 * Since the socket and all its associations are going away, we
353 * can treat this OOTB
354 */
355 if (sctp_sstate(ep->base.sk, CLOSING))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000356 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
Vlad Yasevichbec96402009-07-30 18:08:28 -0400357
Linus Torvalds1da177e2005-04-16 15:20:36 -0700358 /* Verify the INIT chunk before processing it. */
359 err_chunk = NULL;
Eric W. Biedermanf53b5b02012-08-07 07:29:08 +0000360 if (!sctp_verify_init(net, asoc, chunk->chunk_hdr->type,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
362 &err_chunk)) {
363 /* This chunk contains fatal error. It is to be discarded.
364 * Send an ABORT, with causes if there is any.
365 */
366 if (err_chunk) {
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000367 packet = sctp_abort_pkt_new(net, ep, asoc, arg,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368 (__u8 *)(err_chunk->chunk_hdr) +
369 sizeof(sctp_chunkhdr_t),
370 ntohs(err_chunk->chunk_hdr->length) -
371 sizeof(sctp_chunkhdr_t));
372
373 sctp_chunk_free(err_chunk);
374
375 if (packet) {
376 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
377 SCTP_PACKET(packet));
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000378 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379 return SCTP_DISPOSITION_CONSUME;
380 } else {
381 return SCTP_DISPOSITION_NOMEM;
382 }
383 } else {
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000384 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385 commands);
386 }
387 }
388
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900389 /* Grab the INIT header. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390 chunk->subh.init_hdr = (sctp_inithdr_t *)chunk->skb->data;
391
392 /* Tag the variable length parameters. */
393 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
394
395 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
396 if (!new_asoc)
397 goto nomem;
398
Vlad Yasevich409b95a2009-11-10 08:57:34 +0000399 if (sctp_assoc_set_bind_addr_from_ep(new_asoc,
400 sctp_scope(sctp_source(chunk)),
401 GFP_ATOMIC) < 0)
402 goto nomem_init;
403
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404 /* The call, sctp_process_init(), can fail on memory allocation. */
Wei Yongjunde6becd2011-04-19 21:30:51 +0000405 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406 (sctp_init_chunk_t *)chunk->chunk_hdr,
407 GFP_ATOMIC))
408 goto nomem_init;
409
Linus Torvalds1da177e2005-04-16 15:20:36 -0700410 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
411
412 /* If there are errors need to be reported for unknown parameters,
413 * make sure to reserve enough room in the INIT ACK for them.
414 */
415 len = 0;
416 if (err_chunk)
417 len = ntohs(err_chunk->chunk_hdr->length) -
418 sizeof(sctp_chunkhdr_t);
419
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
421 if (!repl)
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700422 goto nomem_init;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423
424 /* If there are errors need to be reported for unknown parameters,
425 * include them in the outgoing INIT ACK as "Unrecognized parameter"
426 * parameter.
427 */
428 if (err_chunk) {
429 /* Get the "Unrecognized parameter" parameter(s) out of the
430 * ERROR chunk generated by sctp_verify_init(). Since the
431 * error cause code for "unknown parameter" and the
432 * "Unrecognized parameter" type is the same, we can
433 * construct the parameters in INIT ACK by copying the
434 * ERROR causes over.
435 */
436 unk_param = (sctp_unrecognized_param_t *)
437 ((__u8 *)(err_chunk->chunk_hdr) +
438 sizeof(sctp_chunkhdr_t));
439 /* Replace the cause code with the "Unrecognized parameter"
440 * parameter type.
441 */
442 sctp_addto_chunk(repl, len, unk_param);
443 sctp_chunk_free(err_chunk);
444 }
445
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700446 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
447
Linus Torvalds1da177e2005-04-16 15:20:36 -0700448 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
449
450 /*
451 * Note: After sending out INIT ACK with the State Cookie parameter,
452 * "Z" MUST NOT allocate any resources, nor keep any states for the
453 * new association. Otherwise, "Z" will be vulnerable to resource
454 * attacks.
455 */
456 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
457
458 return SCTP_DISPOSITION_DELETE_TCB;
459
Linus Torvalds1da177e2005-04-16 15:20:36 -0700460nomem_init:
461 sctp_association_free(new_asoc);
462nomem:
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700463 if (err_chunk)
464 sctp_chunk_free(err_chunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465 return SCTP_DISPOSITION_NOMEM;
466}
467
468/*
469 * Respond to a normal INIT ACK chunk.
470 * We are the side that is initiating the association.
471 *
472 * Section: 5.1 Normal Establishment of an Association, C
473 * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init
474 * timer and leave COOKIE-WAIT state. "A" shall then send the State
475 * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start
476 * the T1-cookie timer, and enter the COOKIE-ECHOED state.
477 *
478 * Note: The COOKIE ECHO chunk can be bundled with any pending outbound
479 * DATA chunks, but it MUST be the first chunk in the packet and
480 * until the COOKIE ACK is returned the sender MUST NOT send any
481 * other packets to the peer.
482 *
483 * Verification Tag: 3.3.3
484 * If the value of the Initiate Tag in a received INIT ACK chunk is
485 * found to be 0, the receiver MUST treat it as an error and close the
486 * association by transmitting an ABORT.
487 *
488 * Inputs
489 * (endpoint, asoc, chunk)
490 *
491 * Outputs
492 * (asoc, reply_msg, msg_up, timers, counters)
493 *
494 * The return value is the disposition of the chunk.
495 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000496sctp_disposition_t sctp_sf_do_5_1C_ack(struct net *net,
497 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498 const struct sctp_association *asoc,
499 const sctp_subtype_t type,
500 void *arg,
501 sctp_cmd_seq_t *commands)
502{
503 struct sctp_chunk *chunk = arg;
504 sctp_init_chunk_t *initchunk;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700505 struct sctp_chunk *err_chunk;
506 struct sctp_packet *packet;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507
508 if (!sctp_vtag_verify(chunk, asoc))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000509 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510
Linus Torvalds1da177e2005-04-16 15:20:36 -0700511 /* 6.10 Bundling
512 * An endpoint MUST NOT bundle INIT, INIT ACK or
513 * SHUTDOWN COMPLETE with any other chunks.
514 */
515 if (!chunk->singleton)
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000516 return sctp_sf_violation_chunk(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517
Vlad Yasevichece25df2007-09-07 16:30:54 -0400518 /* Make sure that the INIT-ACK chunk has a valid length */
519 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_initack_chunk_t)))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000520 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
Vlad Yasevichece25df2007-09-07 16:30:54 -0400521 commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522 /* Grab the INIT header. */
523 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
524
Linus Torvalds1da177e2005-04-16 15:20:36 -0700525 /* Verify the INIT chunk before processing it. */
526 err_chunk = NULL;
Eric W. Biedermanf53b5b02012-08-07 07:29:08 +0000527 if (!sctp_verify_init(net, asoc, chunk->chunk_hdr->type,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
529 &err_chunk)) {
530
Vlad Yasevich853f4b52008-01-20 06:10:46 -0800531 sctp_error_t error = SCTP_ERROR_NO_RESOURCE;
532
Linus Torvalds1da177e2005-04-16 15:20:36 -0700533 /* This chunk contains fatal error. It is to be discarded.
Vlad Yasevichd6701192007-12-20 14:13:31 -0800534 * Send an ABORT, with causes. If there are no causes,
535 * then there wasn't enough memory. Just terminate
536 * the association.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537 */
538 if (err_chunk) {
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000539 packet = sctp_abort_pkt_new(net, ep, asoc, arg,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700540 (__u8 *)(err_chunk->chunk_hdr) +
541 sizeof(sctp_chunkhdr_t),
542 ntohs(err_chunk->chunk_hdr->length) -
543 sizeof(sctp_chunkhdr_t));
544
545 sctp_chunk_free(err_chunk);
546
547 if (packet) {
548 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
549 SCTP_PACKET(packet));
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000550 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700551 error = SCTP_ERROR_INV_PARAM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553 }
Vlad Yasevichbbd0d592007-10-03 17:51:34 -0700554
555 /* SCTP-AUTH, Section 6.3:
556 * It should be noted that if the receiver wants to tear
557 * down an association in an authenticated way only, the
558 * handling of malformed packets should not result in
559 * tearing down the association.
560 *
561 * This means that if we only want to abort associations
562 * in an authenticated way (i.e AUTH+ABORT), then we
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300563 * can't destroy this association just because the packet
Vlad Yasevichbbd0d592007-10-03 17:51:34 -0700564 * was malformed.
565 */
566 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000567 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Vlad Yasevichbbd0d592007-10-03 17:51:34 -0700568
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000569 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
570 return sctp_stop_t1_and_abort(net, commands, error, ECONNREFUSED,
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700571 asoc, chunk->transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700572 }
573
574 /* Tag the variable length parameters. Note that we never
575 * convert the parameters in an INIT chunk.
576 */
577 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
578
579 initchunk = (sctp_init_chunk_t *) chunk->chunk_hdr;
580
581 sctp_add_cmd_sf(commands, SCTP_CMD_PEER_INIT,
582 SCTP_PEER_INIT(initchunk));
583
Frank Filz3f7a87d2005-06-20 13:14:57 -0700584 /* Reset init error count upon receipt of INIT-ACK. */
585 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
586
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587 /* 5.1 C) "A" shall stop the T1-init timer and leave
588 * COOKIE-WAIT state. "A" shall then ... start the T1-cookie
589 * timer, and enter the COOKIE-ECHOED state.
590 */
591 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
592 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
593 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
594 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
595 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
596 SCTP_STATE(SCTP_STATE_COOKIE_ECHOED));
597
Vlad Yasevich730fc3d2007-09-16 19:32:11 -0700598 /* SCTP-AUTH: genereate the assocition shared keys so that
599 * we can potentially signe the COOKIE-ECHO.
600 */
601 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_SHKEY, SCTP_NULL());
602
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603 /* 5.1 C) "A" shall then send the State Cookie received in the
604 * INIT ACK chunk in a COOKIE ECHO chunk, ...
605 */
606 /* If there is any errors to report, send the ERROR chunk generated
607 * for unknown parameters as well.
608 */
609 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_COOKIE_ECHO,
610 SCTP_CHUNK(err_chunk));
611
612 return SCTP_DISPOSITION_CONSUME;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613}
614
615/*
616 * Respond to a normal COOKIE ECHO chunk.
617 * We are the side that is being asked for an association.
618 *
619 * Section: 5.1 Normal Establishment of an Association, D
620 * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply
621 * with a COOKIE ACK chunk after building a TCB and moving to
622 * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with
623 * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK
624 * chunk MUST be the first chunk in the packet.
625 *
626 * IMPLEMENTATION NOTE: An implementation may choose to send the
627 * Communication Up notification to the SCTP user upon reception
628 * of a valid COOKIE ECHO chunk.
629 *
630 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
631 * D) Rules for packet carrying a COOKIE ECHO
632 *
633 * - When sending a COOKIE ECHO, the endpoint MUST use the value of the
634 * Initial Tag received in the INIT ACK.
635 *
636 * - The receiver of a COOKIE ECHO follows the procedures in Section 5.
637 *
638 * Inputs
639 * (endpoint, asoc, chunk)
640 *
641 * Outputs
642 * (asoc, reply_msg, msg_up, timers, counters)
643 *
644 * The return value is the disposition of the chunk.
645 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000646sctp_disposition_t sctp_sf_do_5_1D_ce(struct net *net,
647 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648 const struct sctp_association *asoc,
649 const sctp_subtype_t type, void *arg,
650 sctp_cmd_seq_t *commands)
651{
652 struct sctp_chunk *chunk = arg;
653 struct sctp_association *new_asoc;
654 sctp_init_chunk_t *peer_init;
655 struct sctp_chunk *repl;
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700656 struct sctp_ulpevent *ev, *ai_ev = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657 int error = 0;
658 struct sctp_chunk *err_chk_p;
Vlad Yasevich609ee462007-08-31 03:10:59 +0900659 struct sock *sk;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700660
661 /* If the packet is an OOTB packet which is temporarily on the
662 * control endpoint, respond with an ABORT.
663 */
Eric W. Biederman2ce95502012-08-06 08:43:06 +0000664 if (ep == sctp_sk(net->sctp.ctl_sock)->ep) {
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000665 SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000666 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
Wei Yongjun8190f892008-09-08 12:13:55 +0800667 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668
669 /* Make sure that the COOKIE_ECHO chunk has a valid length.
670 * In this case, we check that we have enough for at least a
671 * chunk header. More detailed verification is done
672 * in sctp_unpack_cookie().
673 */
674 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000675 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676
Vlad Yasevich609ee462007-08-31 03:10:59 +0900677 /* If the endpoint is not listening or if the number of associations
678 * on the TCP-style socket exceed the max backlog, respond with an
679 * ABORT.
680 */
681 sk = ep->base.sk;
682 if (!sctp_sstate(sk, LISTENING) ||
683 (sctp_style(sk, TCP) && sk_acceptq_is_full(sk)))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000684 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
Vlad Yasevich609ee462007-08-31 03:10:59 +0900685
Linus Torvalds1da177e2005-04-16 15:20:36 -0700686 /* "Decode" the chunk. We have no optional parameters so we
687 * are in good shape.
688 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900689 chunk->subh.cookie_hdr =
Linus Torvalds1da177e2005-04-16 15:20:36 -0700690 (struct sctp_signed_cookie *)chunk->skb->data;
Sridhar Samudrala62b08082006-05-05 17:04:43 -0700691 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
692 sizeof(sctp_chunkhdr_t)))
693 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700694
695 /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
696 * "Z" will reply with a COOKIE ACK chunk after building a TCB
697 * and moving to the ESTABLISHED state.
698 */
699 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
700 &err_chk_p);
701
702 /* FIXME:
703 * If the re-build failed, what is the proper error path
704 * from here?
705 *
706 * [We should abort the association. --piggy]
707 */
708 if (!new_asoc) {
709 /* FIXME: Several errors are possible. A bad cookie should
710 * be silently discarded, but think about logging it too.
711 */
712 switch (error) {
713 case -SCTP_IERROR_NOMEM:
714 goto nomem;
715
716 case -SCTP_IERROR_STALE_COOKIE:
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000717 sctp_send_stale_cookie_err(net, ep, asoc, chunk, commands,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718 err_chk_p);
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000719 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700720
721 case -SCTP_IERROR_BAD_SIG:
722 default:
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000723 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700724 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700725 }
726
Linus Torvalds1da177e2005-04-16 15:20:36 -0700727
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700728 /* Delay state machine commands until later.
729 *
730 * Re-build the bind address for the association is done in
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731 * the sctp_unpack_cookie() already.
732 */
733 /* This is a brand-new association, so these are not yet side
734 * effects--it is safe to run them here.
735 */
736 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
737
Wei Yongjunde6becd2011-04-19 21:30:51 +0000738 if (!sctp_process_init(new_asoc, chunk,
Al Viro6a1e5f32006-11-20 17:12:25 -0800739 &chunk->subh.cookie_hdr->c.peer_addr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700740 peer_init, GFP_ATOMIC))
741 goto nomem_init;
742
Vlad Yasevich730fc3d2007-09-16 19:32:11 -0700743 /* SCTP-AUTH: Now that we've populate required fields in
744 * sctp_process_init, set up the assocaition shared keys as
745 * necessary so that we can potentially authenticate the ACK
746 */
747 error = sctp_auth_asoc_init_active_key(new_asoc, GFP_ATOMIC);
748 if (error)
749 goto nomem_init;
750
Vlad Yasevichbbd0d592007-10-03 17:51:34 -0700751 /* SCTP-AUTH: auth_chunk pointer is only set when the cookie-echo
752 * is supposed to be authenticated and we have to do delayed
753 * authentication. We've just recreated the association using
754 * the information in the cookie and now it's much easier to
755 * do the authentication.
756 */
757 if (chunk->auth_chunk) {
758 struct sctp_chunk auth;
759 sctp_ierror_t ret;
760
Daniel Borkmannec0223e2014-03-03 17:23:04 +0100761 /* Make sure that we and the peer are AUTH capable */
762 if (!net->sctp.auth_enable || !new_asoc->peer.auth_capable) {
Daniel Borkmannec0223e2014-03-03 17:23:04 +0100763 sctp_association_free(new_asoc);
764 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
765 }
766
Vlad Yasevichbbd0d592007-10-03 17:51:34 -0700767 /* set-up our fake chunk so that we can process it */
768 auth.skb = chunk->auth_chunk;
769 auth.asoc = chunk->asoc;
770 auth.sctp_hdr = chunk->sctp_hdr;
771 auth.chunk_hdr = (sctp_chunkhdr_t *)skb_push(chunk->auth_chunk,
772 sizeof(sctp_chunkhdr_t));
773 skb_pull(chunk->auth_chunk, sizeof(sctp_chunkhdr_t));
774 auth.transport = chunk->transport;
775
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000776 ret = sctp_sf_authenticate(net, ep, new_asoc, type, &auth);
Vlad Yasevichbbd0d592007-10-03 17:51:34 -0700777 if (ret != SCTP_IERROR_NO_ERROR) {
778 sctp_association_free(new_asoc);
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000779 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Vlad Yasevichbbd0d592007-10-03 17:51:34 -0700780 }
781 }
782
Linus Torvalds1da177e2005-04-16 15:20:36 -0700783 repl = sctp_make_cookie_ack(new_asoc, chunk);
784 if (!repl)
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700785 goto nomem_init;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786
787 /* RFC 2960 5.1 Normal Establishment of an Association
788 *
789 * D) IMPLEMENTATION NOTE: An implementation may choose to
790 * send the Communication Up notification to the SCTP user
791 * upon reception of a valid COOKIE ECHO chunk.
792 */
793 ev = sctp_ulpevent_make_assoc_change(new_asoc, 0, SCTP_COMM_UP, 0,
794 new_asoc->c.sinit_num_ostreams,
795 new_asoc->c.sinit_max_instreams,
Vlad Yasevicha5a35e72007-03-23 11:34:08 -0700796 NULL, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700797 if (!ev)
798 goto nomem_ev;
799
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900800 /* Sockets API Draft Section 5.3.1.6
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -0800801 * When a peer sends a Adaptation Layer Indication parameter , SCTP
Linus Torvalds1da177e2005-04-16 15:20:36 -0700802 * delivers this notification to inform the application that of the
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -0800803 * peers requested adaptation layer.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700804 */
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -0800805 if (new_asoc->peer.adaptation_ind) {
806 ai_ev = sctp_ulpevent_make_adaptation_indication(new_asoc,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700807 GFP_ATOMIC);
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700808 if (!ai_ev)
809 goto nomem_aiev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700810 }
811
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700812 /* Add all the state machine commands now since we've created
813 * everything. This way we don't introduce memory corruptions
814 * during side-effect processing and correclty count established
815 * associations.
816 */
817 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
818 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
819 SCTP_STATE(SCTP_STATE_ESTABLISHED));
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000820 SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
821 SCTP_INC_STATS(net, SCTP_MIB_PASSIVEESTABS);
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700822 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
823
Neil Horman9f70f462013-12-10 06:48:15 -0500824 if (new_asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700825 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
826 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
827
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700828 /* This will send the COOKIE ACK */
829 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
830
831 /* Queue the ASSOC_CHANGE event */
832 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
833
834 /* Send up the Adaptation Layer Indication event */
835 if (ai_ev)
836 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
837 SCTP_ULPEVENT(ai_ev));
838
Linus Torvalds1da177e2005-04-16 15:20:36 -0700839 return SCTP_DISPOSITION_CONSUME;
840
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700841nomem_aiev:
842 sctp_ulpevent_free(ev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700843nomem_ev:
844 sctp_chunk_free(repl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700845nomem_init:
846 sctp_association_free(new_asoc);
847nomem:
848 return SCTP_DISPOSITION_NOMEM;
849}
850
851/*
852 * Respond to a normal COOKIE ACK chunk.
853 * We are the side that is being asked for an association.
854 *
855 * RFC 2960 5.1 Normal Establishment of an Association
856 *
857 * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the
858 * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie
859 * timer. It may also notify its ULP about the successful
860 * establishment of the association with a Communication Up
861 * notification (see Section 10).
862 *
863 * Verification Tag:
864 * Inputs
865 * (endpoint, asoc, chunk)
866 *
867 * Outputs
868 * (asoc, reply_msg, msg_up, timers, counters)
869 *
870 * The return value is the disposition of the chunk.
871 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000872sctp_disposition_t sctp_sf_do_5_1E_ca(struct net *net,
873 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700874 const struct sctp_association *asoc,
875 const sctp_subtype_t type, void *arg,
876 sctp_cmd_seq_t *commands)
877{
878 struct sctp_chunk *chunk = arg;
879 struct sctp_ulpevent *ev;
880
881 if (!sctp_vtag_verify(chunk, asoc))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000882 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883
884 /* Verify that the chunk length for the COOKIE-ACK is OK.
885 * If we don't do this, any bundled chunks may be junked.
886 */
887 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000888 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700889 commands);
890
891 /* Reset init error count upon receipt of COOKIE-ACK,
892 * to avoid problems with the managemement of this
893 * counter in stale cookie situations when a transition back
894 * from the COOKIE-ECHOED state to the COOKIE-WAIT
895 * state is performed.
896 */
Frank Filz3f7a87d2005-06-20 13:14:57 -0700897 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
Linus Torvalds1da177e2005-04-16 15:20:36 -0700898
899 /* RFC 2960 5.1 Normal Establishment of an Association
900 *
901 * E) Upon reception of the COOKIE ACK, endpoint "A" will move
902 * from the COOKIE-ECHOED state to the ESTABLISHED state,
903 * stopping the T1-cookie timer.
904 */
905 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
906 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
907 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
908 SCTP_STATE(SCTP_STATE_ESTABLISHED));
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000909 SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
910 SCTP_INC_STATS(net, SCTP_MIB_ACTIVEESTABS);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700911 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
Neil Horman9f70f462013-12-10 06:48:15 -0500912 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
Linus Torvalds1da177e2005-04-16 15:20:36 -0700913 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
914 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700915
916 /* It may also notify its ULP about the successful
917 * establishment of the association with a Communication Up
918 * notification (see Section 10).
919 */
920 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP,
921 0, asoc->c.sinit_num_ostreams,
922 asoc->c.sinit_max_instreams,
Vlad Yasevicha5a35e72007-03-23 11:34:08 -0700923 NULL, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700924
925 if (!ev)
926 goto nomem;
927
928 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
929
930 /* Sockets API Draft Section 5.3.1.6
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -0800931 * When a peer sends a Adaptation Layer Indication parameter , SCTP
Linus Torvalds1da177e2005-04-16 15:20:36 -0700932 * delivers this notification to inform the application that of the
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -0800933 * peers requested adaptation layer.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700934 */
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -0800935 if (asoc->peer.adaptation_ind) {
936 ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700937 if (!ev)
938 goto nomem;
939
940 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
941 SCTP_ULPEVENT(ev));
942 }
943
944 return SCTP_DISPOSITION_CONSUME;
945nomem:
946 return SCTP_DISPOSITION_NOMEM;
947}
948
949/* Generate and sendout a heartbeat packet. */
950static sctp_disposition_t sctp_sf_heartbeat(const struct sctp_endpoint *ep,
951 const struct sctp_association *asoc,
952 const sctp_subtype_t type,
953 void *arg,
954 sctp_cmd_seq_t *commands)
955{
956 struct sctp_transport *transport = (struct sctp_transport *) arg;
957 struct sctp_chunk *reply;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700958
959 /* Send a heartbeat to our peer. */
Wei Yongjun92c73af2011-04-19 21:31:47 +0000960 reply = sctp_make_heartbeat(asoc, transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700961 if (!reply)
962 return SCTP_DISPOSITION_NOMEM;
963
964 /* Set rto_pending indicating that an RTT measurement
965 * is started with this heartbeat chunk.
966 */
967 sctp_add_cmd_sf(commands, SCTP_CMD_RTO_PENDING,
968 SCTP_TRANSPORT(transport));
969
970 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
971 return SCTP_DISPOSITION_CONSUME;
972}
973
974/* Generate a HEARTBEAT packet on the given transport. */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +0000975sctp_disposition_t sctp_sf_sendbeat_8_3(struct net *net,
976 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700977 const struct sctp_association *asoc,
978 const sctp_subtype_t type,
979 void *arg,
980 sctp_cmd_seq_t *commands)
981{
982 struct sctp_transport *transport = (struct sctp_transport *) arg;
983
Vlad Yasevichb9f84782009-08-26 09:36:25 -0400984 if (asoc->overall_error_count >= asoc->max_retrans) {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700985 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
986 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700987 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
988 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -0800989 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Eric W. Biedermanb01a2402012-08-06 08:47:55 +0000990 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
991 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700992 return SCTP_DISPOSITION_DELETE_TCB;
993 }
994
995 /* Section 3.3.5.
996 * The Sender-specific Heartbeat Info field should normally include
997 * information about the sender's current time when this HEARTBEAT
998 * chunk is sent and the destination transport address to which this
999 * HEARTBEAT is sent (see Section 8.3).
1000 */
1001
Frank Filz52ccb8e2005-12-22 11:36:46 -08001002 if (transport->param_flags & SPP_HB_ENABLE) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001003 if (SCTP_DISPOSITION_NOMEM ==
1004 sctp_sf_heartbeat(ep, asoc, type, arg,
1005 commands))
1006 return SCTP_DISPOSITION_NOMEM;
Vlad Yasevich245cba72009-11-23 15:53:58 -05001007
Linus Torvalds1da177e2005-04-16 15:20:36 -07001008 /* Set transport error counter and association error counter
1009 * when sending heartbeat.
1010 */
Vlad Yasevich7e990132009-03-02 09:46:14 +00001011 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_HB_SENT,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001012 SCTP_TRANSPORT(transport));
1013 }
Vlad Yasevich245cba72009-11-23 15:53:58 -05001014 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_IDLE,
1015 SCTP_TRANSPORT(transport));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001016 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMER_UPDATE,
1017 SCTP_TRANSPORT(transport));
1018
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001019 return SCTP_DISPOSITION_CONSUME;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001020}
1021
1022/*
1023 * Process an heartbeat request.
1024 *
1025 * Section: 8.3 Path Heartbeat
1026 * The receiver of the HEARTBEAT should immediately respond with a
1027 * HEARTBEAT ACK that contains the Heartbeat Information field copied
1028 * from the received HEARTBEAT chunk.
1029 *
1030 * Verification Tag: 8.5 Verification Tag [Normal verification]
1031 * When receiving an SCTP packet, the endpoint MUST ensure that the
1032 * value in the Verification Tag field of the received SCTP packet
1033 * matches its own Tag. If the received Verification Tag value does not
1034 * match the receiver's own tag value, the receiver shall silently
1035 * discard the packet and shall not process it any further except for
1036 * those cases listed in Section 8.5.1 below.
1037 *
1038 * Inputs
1039 * (endpoint, asoc, chunk)
1040 *
1041 * Outputs
1042 * (asoc, reply_msg, msg_up, timers, counters)
1043 *
1044 * The return value is the disposition of the chunk.
1045 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00001046sctp_disposition_t sctp_sf_beat_8_3(struct net *net,
1047 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001048 const struct sctp_association *asoc,
1049 const sctp_subtype_t type,
1050 void *arg,
1051 sctp_cmd_seq_t *commands)
1052{
Thomas Graf06a31e22012-11-30 02:16:27 +00001053 sctp_paramhdr_t *param_hdr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001054 struct sctp_chunk *chunk = arg;
1055 struct sctp_chunk *reply;
1056 size_t paylen = 0;
1057
1058 if (!sctp_vtag_verify(chunk, asoc))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00001059 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001060
1061 /* Make sure that the HEARTBEAT chunk has a valid length. */
1062 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t)))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00001063 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001064 commands);
1065
1066 /* 8.3 The receiver of the HEARTBEAT should immediately
1067 * respond with a HEARTBEAT ACK that contains the Heartbeat
1068 * Information field copied from the received HEARTBEAT chunk.
1069 */
1070 chunk->subh.hb_hdr = (sctp_heartbeathdr_t *) chunk->skb->data;
Thomas Graf06a31e22012-11-30 02:16:27 +00001071 param_hdr = (sctp_paramhdr_t *) chunk->subh.hb_hdr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001072 paylen = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
Thomas Graf06a31e22012-11-30 02:16:27 +00001073
1074 if (ntohs(param_hdr->length) > paylen)
1075 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
1076 param_hdr, commands);
1077
Sridhar Samudrala62b08082006-05-05 17:04:43 -07001078 if (!pskb_pull(chunk->skb, paylen))
1079 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001080
Thomas Graf06a31e22012-11-30 02:16:27 +00001081 reply = sctp_make_heartbeat_ack(asoc, chunk, param_hdr, paylen);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001082 if (!reply)
1083 goto nomem;
1084
1085 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
1086 return SCTP_DISPOSITION_CONSUME;
1087
1088nomem:
1089 return SCTP_DISPOSITION_NOMEM;
1090}
1091
1092/*
1093 * Process the returning HEARTBEAT ACK.
1094 *
1095 * Section: 8.3 Path Heartbeat
1096 * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT
1097 * should clear the error counter of the destination transport
1098 * address to which the HEARTBEAT was sent, and mark the destination
1099 * transport address as active if it is not so marked. The endpoint may
1100 * optionally report to the upper layer when an inactive destination
1101 * address is marked as active due to the reception of the latest
1102 * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also
1103 * clear the association overall error count as well (as defined
1104 * in section 8.1).
1105 *
1106 * The receiver of the HEARTBEAT ACK should also perform an RTT
1107 * measurement for that destination transport address using the time
1108 * value carried in the HEARTBEAT ACK chunk.
1109 *
1110 * Verification Tag: 8.5 Verification Tag [Normal verification]
1111 *
1112 * Inputs
1113 * (endpoint, asoc, chunk)
1114 *
1115 * Outputs
1116 * (asoc, reply_msg, msg_up, timers, counters)
1117 *
1118 * The return value is the disposition of the chunk.
1119 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00001120sctp_disposition_t sctp_sf_backbeat_8_3(struct net *net,
1121 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001122 const struct sctp_association *asoc,
1123 const sctp_subtype_t type,
1124 void *arg,
1125 sctp_cmd_seq_t *commands)
1126{
1127 struct sctp_chunk *chunk = arg;
1128 union sctp_addr from_addr;
1129 struct sctp_transport *link;
1130 sctp_sender_hb_info_t *hbinfo;
1131 unsigned long max_interval;
1132
1133 if (!sctp_vtag_verify(chunk, asoc))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00001134 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001135
1136 /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */
Wei Yongjundadb50c2009-08-22 11:27:37 +08001137 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t) +
1138 sizeof(sctp_sender_hb_info_t)))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00001139 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001140 commands);
1141
1142 hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
Vladislav Yasevicha6012662006-05-19 14:25:53 -07001143 /* Make sure that the length of the parameter is what we expect */
1144 if (ntohs(hbinfo->param_hdr.length) !=
1145 sizeof(sctp_sender_hb_info_t)) {
1146 return SCTP_DISPOSITION_DISCARD;
1147 }
1148
Linus Torvalds1da177e2005-04-16 15:20:36 -07001149 from_addr = hbinfo->daddr;
Al Viro63de08f2006-11-20 17:07:25 -08001150 link = sctp_assoc_lookup_paddr(asoc, &from_addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001151
1152 /* This should never happen, but lets log it if so. */
Frank Filz3f7a87d2005-06-20 13:14:57 -07001153 if (unlikely(!link)) {
1154 if (from_addr.sa.sa_family == AF_INET6) {
Joe Perchese87cc472012-05-13 21:56:26 +00001155 net_warn_ratelimited("%s association %p could not find address %pI6\n",
1156 __func__,
1157 asoc,
1158 &from_addr.v6.sin6_addr);
Frank Filz3f7a87d2005-06-20 13:14:57 -07001159 } else {
Joe Perchese87cc472012-05-13 21:56:26 +00001160 net_warn_ratelimited("%s association %p could not find address %pI4\n",
1161 __func__,
1162 asoc,
1163 &from_addr.v4.sin_addr.s_addr);
Frank Filz3f7a87d2005-06-20 13:14:57 -07001164 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001165 return SCTP_DISPOSITION_DISCARD;
1166 }
1167
Sridhar Samudralaad8fec12006-07-21 14:48:50 -07001168 /* Validate the 64-bit random nonce. */
1169 if (hbinfo->hb_nonce != link->hb_nonce)
1170 return SCTP_DISPOSITION_DISCARD;
1171
Frank Filz52ccb8e2005-12-22 11:36:46 -08001172 max_interval = link->hbinterval + link->rto;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001173
1174 /* Check if the timestamp looks valid. */
1175 if (time_after(hbinfo->sent_at, jiffies) ||
1176 time_after(jiffies, hbinfo->sent_at + max_interval)) {
Daniel Borkmannbb333812013-06-28 19:49:40 +02001177 pr_debug("%s: HEARTBEAT ACK with invalid timestamp received "
1178 "for transport:%p\n", __func__, link);
1179
Linus Torvalds1da177e2005-04-16 15:20:36 -07001180 return SCTP_DISPOSITION_DISCARD;
1181 }
1182
1183 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of
1184 * the HEARTBEAT should clear the error counter of the
1185 * destination transport address to which the HEARTBEAT was
1186 * sent and mark the destination transport address as active if
1187 * it is not so marked.
1188 */
1189 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_ON, SCTP_TRANSPORT(link));
1190
1191 return SCTP_DISPOSITION_CONSUME;
1192}
1193
1194/* Helper function to send out an abort for the restart
1195 * condition.
1196 */
Eric W. Biederman2ce95502012-08-06 08:43:06 +00001197static int sctp_sf_send_restart_abort(struct net *net, union sctp_addr *ssa,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001198 struct sctp_chunk *init,
1199 sctp_cmd_seq_t *commands)
1200{
1201 int len;
1202 struct sctp_packet *pkt;
1203 union sctp_addr_param *addrparm;
1204 struct sctp_errhdr *errhdr;
1205 struct sctp_endpoint *ep;
1206 char buffer[sizeof(struct sctp_errhdr)+sizeof(union sctp_addr_param)];
1207 struct sctp_af *af = sctp_get_af_specific(ssa->v4.sin_family);
1208
1209 /* Build the error on the stack. We are way to malloc crazy
1210 * throughout the code today.
1211 */
1212 errhdr = (struct sctp_errhdr *)buffer;
1213 addrparm = (union sctp_addr_param *)errhdr->variable;
1214
1215 /* Copy into a parm format. */
1216 len = af->to_addr_param(ssa, addrparm);
1217 len += sizeof(sctp_errhdr_t);
1218
1219 errhdr->cause = SCTP_ERROR_RESTART;
1220 errhdr->length = htons(len);
1221
1222 /* Assign to the control socket. */
Eric W. Biederman2ce95502012-08-06 08:43:06 +00001223 ep = sctp_sk(net->sctp.ctl_sock)->ep;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001224
1225 /* Association is NULL since this may be a restart attack and we
1226 * want to send back the attacker's vtag.
1227 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00001228 pkt = sctp_abort_pkt_new(net, ep, NULL, init, errhdr, len);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001229
1230 if (!pkt)
1231 goto out;
1232 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, SCTP_PACKET(pkt));
1233
Eric W. Biedermanb01a2402012-08-06 08:47:55 +00001234 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001235
1236 /* Discard the rest of the inbound packet. */
1237 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
1238
1239out:
1240 /* Even if there is no memory, treat as a failure so
1241 * the packet will get dropped.
1242 */
1243 return 0;
1244}
1245
Joe Perches123031c2010-09-08 11:04:21 +00001246static bool list_has_sctp_addr(const struct list_head *list,
1247 union sctp_addr *ipaddr)
1248{
1249 struct sctp_transport *addr;
1250
1251 list_for_each_entry(addr, list, transports) {
1252 if (sctp_cmp_addr_exact(ipaddr, &addr->ipaddr))
1253 return true;
1254 }
1255
1256 return false;
1257}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001258/* A restart is occurring, check to make sure no new addresses
1259 * are being added as we may be under a takeover attack.
1260 */
1261static int sctp_sf_check_restart_addrs(const struct sctp_association *new_asoc,
1262 const struct sctp_association *asoc,
1263 struct sctp_chunk *init,
1264 sctp_cmd_seq_t *commands)
1265{
Eric W. Biederman2ce95502012-08-06 08:43:06 +00001266 struct net *net = sock_net(new_asoc->base.sk);
Joe Perches123031c2010-09-08 11:04:21 +00001267 struct sctp_transport *new_addr;
1268 int ret = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001269
Joe Perches123031c2010-09-08 11:04:21 +00001270 /* Implementor's Guide - Section 5.2.2
Linus Torvalds1da177e2005-04-16 15:20:36 -07001271 * ...
1272 * Before responding the endpoint MUST check to see if the
1273 * unexpected INIT adds new addresses to the association. If new
1274 * addresses are added to the association, the endpoint MUST respond
1275 * with an ABORT..
1276 */
1277
1278 /* Search through all current addresses and make sure
1279 * we aren't adding any new ones.
1280 */
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -07001281 list_for_each_entry(new_addr, &new_asoc->peer.transport_addr_list,
Joe Perches123031c2010-09-08 11:04:21 +00001282 transports) {
1283 if (!list_has_sctp_addr(&asoc->peer.transport_addr_list,
1284 &new_addr->ipaddr)) {
Eric W. Biederman2ce95502012-08-06 08:43:06 +00001285 sctp_sf_send_restart_abort(net, &new_addr->ipaddr, init,
Joe Perches123031c2010-09-08 11:04:21 +00001286 commands);
1287 ret = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001288 break;
Joe Perches123031c2010-09-08 11:04:21 +00001289 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001290 }
1291
1292 /* Return success if all addresses were found. */
Joe Perches123031c2010-09-08 11:04:21 +00001293 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001294}
1295
1296/* Populate the verification/tie tags based on overlapping INIT
1297 * scenario.
1298 *
1299 * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state.
1300 */
1301static void sctp_tietags_populate(struct sctp_association *new_asoc,
1302 const struct sctp_association *asoc)
1303{
1304 switch (asoc->state) {
1305
1306 /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */
1307
1308 case SCTP_STATE_COOKIE_WAIT:
1309 new_asoc->c.my_vtag = asoc->c.my_vtag;
1310 new_asoc->c.my_ttag = asoc->c.my_vtag;
1311 new_asoc->c.peer_ttag = 0;
1312 break;
1313
1314 case SCTP_STATE_COOKIE_ECHOED:
1315 new_asoc->c.my_vtag = asoc->c.my_vtag;
1316 new_asoc->c.my_ttag = asoc->c.my_vtag;
1317 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1318 break;
1319
1320 /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED,
1321 * COOKIE-WAIT and SHUTDOWN-ACK-SENT
1322 */
1323 default:
1324 new_asoc->c.my_ttag = asoc->c.my_vtag;
1325 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1326 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07001327 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001328
1329 /* Other parameters for the endpoint SHOULD be copied from the
1330 * existing parameters of the association (e.g. number of
1331 * outbound streams) into the INIT ACK and cookie.
1332 */
1333 new_asoc->rwnd = asoc->rwnd;
1334 new_asoc->c.sinit_num_ostreams = asoc->c.sinit_num_ostreams;
1335 new_asoc->c.sinit_max_instreams = asoc->c.sinit_max_instreams;
1336 new_asoc->c.initial_tsn = asoc->c.initial_tsn;
1337}
1338
1339/*
1340 * Compare vtag/tietag values to determine unexpected COOKIE-ECHO
1341 * handling action.
1342 *
1343 * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists.
1344 *
1345 * Returns value representing action to be taken. These action values
1346 * correspond to Action/Description values in RFC 2960, Table 2.
1347 */
1348static char sctp_tietags_compare(struct sctp_association *new_asoc,
1349 const struct sctp_association *asoc)
1350{
1351 /* In this case, the peer may have restarted. */
1352 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1353 (asoc->c.peer_vtag != new_asoc->c.peer_vtag) &&
1354 (asoc->c.my_vtag == new_asoc->c.my_ttag) &&
1355 (asoc->c.peer_vtag == new_asoc->c.peer_ttag))
1356 return 'A';
1357
1358 /* Collision case B. */
1359 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1360 ((asoc->c.peer_vtag != new_asoc->c.peer_vtag) ||
1361 (0 == asoc->c.peer_vtag))) {
1362 return 'B';
1363 }
1364
1365 /* Collision case D. */
1366 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1367 (asoc->c.peer_vtag == new_asoc->c.peer_vtag))
1368 return 'D';
1369
1370 /* Collision case C. */
1371 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1372 (asoc->c.peer_vtag == new_asoc->c.peer_vtag) &&
1373 (0 == new_asoc->c.my_ttag) &&
1374 (0 == new_asoc->c.peer_ttag))
1375 return 'C';
1376
1377 /* No match to any of the special cases; discard this packet. */
1378 return 'E';
1379}
1380
1381/* Common helper routine for both duplicate and simulataneous INIT
1382 * chunk handling.
1383 */
1384static sctp_disposition_t sctp_sf_do_unexpected_init(
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00001385 struct net *net,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001386 const struct sctp_endpoint *ep,
1387 const struct sctp_association *asoc,
1388 const sctp_subtype_t type,
1389 void *arg, sctp_cmd_seq_t *commands)
1390{
1391 sctp_disposition_t retval;
1392 struct sctp_chunk *chunk = arg;
1393 struct sctp_chunk *repl;
1394 struct sctp_association *new_asoc;
1395 struct sctp_chunk *err_chunk;
1396 struct sctp_packet *packet;
1397 sctp_unrecognized_param_t *unk_param;
1398 int len;
1399
1400 /* 6.10 Bundling
1401 * An endpoint MUST NOT bundle INIT, INIT ACK or
1402 * SHUTDOWN COMPLETE with any other chunks.
1403 *
1404 * IG Section 2.11.2
1405 * Furthermore, we require that the receiver of an INIT chunk MUST
1406 * enforce these rules by silently discarding an arriving packet
1407 * with an INIT chunk that is bundled with other chunks.
1408 */
1409 if (!chunk->singleton)
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00001410 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001411
1412 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001413 * Tag.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001414 */
1415 if (chunk->sctp_hdr->vtag != 0)
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00001416 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001417
1418 /* Make sure that the INIT chunk has a valid length.
1419 * In this case, we generate a protocol violation since we have
1420 * an association established.
1421 */
1422 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00001423 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001424 commands);
1425 /* Grab the INIT header. */
1426 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
1427
1428 /* Tag the variable length parameters. */
1429 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
1430
1431 /* Verify the INIT chunk before processing it. */
1432 err_chunk = NULL;
Eric W. Biedermanf53b5b02012-08-07 07:29:08 +00001433 if (!sctp_verify_init(net, asoc, chunk->chunk_hdr->type,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001434 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
1435 &err_chunk)) {
1436 /* This chunk contains fatal error. It is to be discarded.
1437 * Send an ABORT, with causes if there is any.
1438 */
1439 if (err_chunk) {
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00001440 packet = sctp_abort_pkt_new(net, ep, asoc, arg,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001441 (__u8 *)(err_chunk->chunk_hdr) +
1442 sizeof(sctp_chunkhdr_t),
1443 ntohs(err_chunk->chunk_hdr->length) -
1444 sizeof(sctp_chunkhdr_t));
1445
1446 if (packet) {
1447 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
1448 SCTP_PACKET(packet));
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00001449 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001450 retval = SCTP_DISPOSITION_CONSUME;
1451 } else {
1452 retval = SCTP_DISPOSITION_NOMEM;
1453 }
1454 goto cleanup;
1455 } else {
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00001456 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001457 commands);
1458 }
1459 }
1460
1461 /*
1462 * Other parameters for the endpoint SHOULD be copied from the
1463 * existing parameters of the association (e.g. number of
1464 * outbound streams) into the INIT ACK and cookie.
1465 * FIXME: We are copying parameters from the endpoint not the
1466 * association.
1467 */
1468 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
1469 if (!new_asoc)
1470 goto nomem;
1471
Vlad Yasevich409b95a2009-11-10 08:57:34 +00001472 if (sctp_assoc_set_bind_addr_from_ep(new_asoc,
1473 sctp_scope(sctp_source(chunk)), GFP_ATOMIC) < 0)
1474 goto nomem;
1475
Linus Torvalds1da177e2005-04-16 15:20:36 -07001476 /* In the outbound INIT ACK the endpoint MUST copy its current
1477 * Verification Tag and Peers Verification tag into a reserved
1478 * place (local tie-tag and per tie-tag) within the state cookie.
1479 */
Wei Yongjunde6becd2011-04-19 21:30:51 +00001480 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk),
Linus Torvalds1da177e2005-04-16 15:20:36 -07001481 (sctp_init_chunk_t *)chunk->chunk_hdr,
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001482 GFP_ATOMIC))
1483 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001484
1485 /* Make sure no new addresses are being added during the
1486 * restart. Do not do this check for COOKIE-WAIT state,
1487 * since there are no peer addresses to check against.
1488 * Upon return an ABORT will have been sent if needed.
1489 */
1490 if (!sctp_state(asoc, COOKIE_WAIT)) {
1491 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk,
1492 commands)) {
1493 retval = SCTP_DISPOSITION_CONSUME;
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001494 goto nomem_retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001495 }
1496 }
1497
1498 sctp_tietags_populate(new_asoc, asoc);
1499
1500 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
1501
1502 /* If there are errors need to be reported for unknown parameters,
1503 * make sure to reserve enough room in the INIT ACK for them.
1504 */
1505 len = 0;
1506 if (err_chunk) {
1507 len = ntohs(err_chunk->chunk_hdr->length) -
1508 sizeof(sctp_chunkhdr_t);
1509 }
1510
Linus Torvalds1da177e2005-04-16 15:20:36 -07001511 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
1512 if (!repl)
1513 goto nomem;
1514
1515 /* If there are errors need to be reported for unknown parameters,
1516 * include them in the outgoing INIT ACK as "Unrecognized parameter"
1517 * parameter.
1518 */
1519 if (err_chunk) {
1520 /* Get the "Unrecognized parameter" parameter(s) out of the
1521 * ERROR chunk generated by sctp_verify_init(). Since the
1522 * error cause code for "unknown parameter" and the
1523 * "Unrecognized parameter" type is the same, we can
1524 * construct the parameters in INIT ACK by copying the
1525 * ERROR causes over.
1526 */
1527 unk_param = (sctp_unrecognized_param_t *)
1528 ((__u8 *)(err_chunk->chunk_hdr) +
1529 sizeof(sctp_chunkhdr_t));
1530 /* Replace the cause code with the "Unrecognized parameter"
1531 * parameter type.
1532 */
1533 sctp_addto_chunk(repl, len, unk_param);
1534 }
1535
1536 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
1537 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1538
1539 /*
1540 * Note: After sending out INIT ACK with the State Cookie parameter,
1541 * "Z" MUST NOT allocate any resources for this new association.
1542 * Otherwise, "Z" will be vulnerable to resource attacks.
1543 */
1544 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
1545 retval = SCTP_DISPOSITION_CONSUME;
1546
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001547 return retval;
1548
1549nomem:
1550 retval = SCTP_DISPOSITION_NOMEM;
1551nomem_retval:
1552 if (new_asoc)
1553 sctp_association_free(new_asoc);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001554cleanup:
1555 if (err_chunk)
1556 sctp_chunk_free(err_chunk);
1557 return retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001558}
1559
1560/*
Lucas De Marchi25985ed2011-03-30 22:57:33 -03001561 * Handle simultaneous INIT.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001562 * This means we started an INIT and then we got an INIT request from
1563 * our peer.
1564 *
1565 * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B)
1566 * This usually indicates an initialization collision, i.e., each
1567 * endpoint is attempting, at about the same time, to establish an
1568 * association with the other endpoint.
1569 *
1570 * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an
1571 * endpoint MUST respond with an INIT ACK using the same parameters it
1572 * sent in its original INIT chunk (including its Verification Tag,
1573 * unchanged). These original parameters are combined with those from the
1574 * newly received INIT chunk. The endpoint shall also generate a State
1575 * Cookie with the INIT ACK. The endpoint uses the parameters sent in its
1576 * INIT to calculate the State Cookie.
1577 *
1578 * After that, the endpoint MUST NOT change its state, the T1-init
1579 * timer shall be left running and the corresponding TCB MUST NOT be
1580 * destroyed. The normal procedures for handling State Cookies when
1581 * a TCB exists will resolve the duplicate INITs to a single association.
1582 *
1583 * For an endpoint that is in the COOKIE-ECHOED state it MUST populate
1584 * its Tie-Tags with the Tag information of itself and its peer (see
1585 * section 5.2.2 for a description of the Tie-Tags).
1586 *
1587 * Verification Tag: Not explicit, but an INIT can not have a valid
1588 * verification tag, so we skip the check.
1589 *
1590 * Inputs
1591 * (endpoint, asoc, chunk)
1592 *
1593 * Outputs
1594 * (asoc, reply_msg, msg_up, timers, counters)
1595 *
1596 * The return value is the disposition of the chunk.
1597 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00001598sctp_disposition_t sctp_sf_do_5_2_1_siminit(struct net *net,
1599 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001600 const struct sctp_association *asoc,
1601 const sctp_subtype_t type,
1602 void *arg,
1603 sctp_cmd_seq_t *commands)
1604{
1605 /* Call helper to do the real work for both simulataneous and
1606 * duplicate INIT chunk handling.
1607 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00001608 return sctp_sf_do_unexpected_init(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001609}
1610
1611/*
1612 * Handle duplicated INIT messages. These are usually delayed
1613 * restransmissions.
1614 *
1615 * Section: 5.2.2 Unexpected INIT in States Other than CLOSED,
1616 * COOKIE-ECHOED and COOKIE-WAIT
1617 *
1618 * Unless otherwise stated, upon reception of an unexpected INIT for
1619 * this association, the endpoint shall generate an INIT ACK with a
1620 * State Cookie. In the outbound INIT ACK the endpoint MUST copy its
1621 * current Verification Tag and peer's Verification Tag into a reserved
1622 * place within the state cookie. We shall refer to these locations as
1623 * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet
1624 * containing this INIT ACK MUST carry a Verification Tag value equal to
1625 * the Initiation Tag found in the unexpected INIT. And the INIT ACK
1626 * MUST contain a new Initiation Tag (randomly generated see Section
1627 * 5.3.1). Other parameters for the endpoint SHOULD be copied from the
1628 * existing parameters of the association (e.g. number of outbound
1629 * streams) into the INIT ACK and cookie.
1630 *
1631 * After sending out the INIT ACK, the endpoint shall take no further
1632 * actions, i.e., the existing association, including its current state,
1633 * and the corresponding TCB MUST NOT be changed.
1634 *
1635 * Note: Only when a TCB exists and the association is not in a COOKIE-
1636 * WAIT state are the Tie-Tags populated. For a normal association INIT
1637 * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be
1638 * set to 0 (indicating that no previous TCB existed). The INIT ACK and
1639 * State Cookie are populated as specified in section 5.2.1.
1640 *
1641 * Verification Tag: Not specified, but an INIT has no way of knowing
1642 * what the verification tag could be, so we ignore it.
1643 *
1644 * Inputs
1645 * (endpoint, asoc, chunk)
1646 *
1647 * Outputs
1648 * (asoc, reply_msg, msg_up, timers, counters)
1649 *
1650 * The return value is the disposition of the chunk.
1651 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00001652sctp_disposition_t sctp_sf_do_5_2_2_dupinit(struct net *net,
1653 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001654 const struct sctp_association *asoc,
1655 const sctp_subtype_t type,
1656 void *arg,
1657 sctp_cmd_seq_t *commands)
1658{
1659 /* Call helper to do the real work for both simulataneous and
1660 * duplicate INIT chunk handling.
1661 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00001662 return sctp_sf_do_unexpected_init(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001663}
1664
1665
Vlad Yasevich610ab732007-01-15 19:18:30 -08001666/*
1667 * Unexpected INIT-ACK handler.
1668 *
1669 * Section 5.2.3
1670 * If an INIT ACK received by an endpoint in any state other than the
1671 * COOKIE-WAIT state, the endpoint should discard the INIT ACK chunk.
1672 * An unexpected INIT ACK usually indicates the processing of an old or
1673 * duplicated INIT chunk.
1674*/
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00001675sctp_disposition_t sctp_sf_do_5_2_3_initack(struct net *net,
1676 const struct sctp_endpoint *ep,
Vlad Yasevich610ab732007-01-15 19:18:30 -08001677 const struct sctp_association *asoc,
1678 const sctp_subtype_t type,
1679 void *arg, sctp_cmd_seq_t *commands)
1680{
1681 /* Per the above section, we'll discard the chunk if we have an
1682 * endpoint. If this is an OOTB INIT-ACK, treat it as such.
1683 */
Eric W. Biederman2ce95502012-08-06 08:43:06 +00001684 if (ep == sctp_sk(net->sctp.ctl_sock)->ep)
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00001685 return sctp_sf_ootb(net, ep, asoc, type, arg, commands);
Vlad Yasevich610ab732007-01-15 19:18:30 -08001686 else
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00001687 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
Vlad Yasevich610ab732007-01-15 19:18:30 -08001688}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001689
1690/* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A')
1691 *
1692 * Section 5.2.4
1693 * A) In this case, the peer may have restarted.
1694 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00001695static sctp_disposition_t sctp_sf_do_dupcook_a(struct net *net,
1696 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001697 const struct sctp_association *asoc,
1698 struct sctp_chunk *chunk,
1699 sctp_cmd_seq_t *commands,
1700 struct sctp_association *new_asoc)
1701{
1702 sctp_init_chunk_t *peer_init;
1703 struct sctp_ulpevent *ev;
1704 struct sctp_chunk *repl;
1705 struct sctp_chunk *err;
1706 sctp_disposition_t disposition;
1707
1708 /* new_asoc is a brand-new association, so these are not yet
1709 * side effects--it is safe to run them here.
1710 */
1711 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1712
Wei Yongjunde6becd2011-04-19 21:30:51 +00001713 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), peer_init,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001714 GFP_ATOMIC))
1715 goto nomem;
1716
1717 /* Make sure no new addresses are being added during the
1718 * restart. Though this is a pretty complicated attack
1719 * since you'd have to get inside the cookie.
1720 */
1721 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk, commands)) {
1722 return SCTP_DISPOSITION_CONSUME;
1723 }
1724
1725 /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes
1726 * the peer has restarted (Action A), it MUST NOT setup a new
1727 * association but instead resend the SHUTDOWN ACK and send an ERROR
1728 * chunk with a "Cookie Received while Shutting Down" error cause to
1729 * its peer.
1730 */
1731 if (sctp_state(asoc, SHUTDOWN_ACK_SENT)) {
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00001732 disposition = sctp_sf_do_9_2_reshutack(net, ep, asoc,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001733 SCTP_ST_CHUNK(chunk->chunk_hdr->type),
1734 chunk, commands);
1735 if (SCTP_DISPOSITION_NOMEM == disposition)
1736 goto nomem;
1737
1738 err = sctp_make_op_error(asoc, chunk,
1739 SCTP_ERROR_COOKIE_IN_SHUTDOWN,
Vlad Yasevich6383cfb2009-11-23 15:53:56 -05001740 NULL, 0, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001741 if (err)
1742 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1743 SCTP_CHUNK(err));
1744
1745 return SCTP_DISPOSITION_CONSUME;
1746 }
1747
Wei Yongjuna000c012011-05-29 23:23:36 +00001748 /* For now, stop pending T3-rtx and SACK timers, fail any unsent/unacked
1749 * data. Consider the optional choice of resending of this data.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001750 */
Wei Yongjuna000c012011-05-29 23:23:36 +00001751 sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
1752 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1753 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001754 sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_OUTQUEUE, SCTP_NULL());
1755
Wei Yongjuna000c012011-05-29 23:23:36 +00001756 /* Stop pending T4-rto timer, teardown ASCONF queue, ASCONF-ACK queue
1757 * and ASCONF-ACK cache.
1758 */
1759 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1760 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
1761 sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_ASCONF_QUEUE, SCTP_NULL());
1762
Linus Torvalds1da177e2005-04-16 15:20:36 -07001763 repl = sctp_make_cookie_ack(new_asoc, chunk);
1764 if (!repl)
1765 goto nomem;
1766
Linus Torvalds1da177e2005-04-16 15:20:36 -07001767 /* Report association restart to upper layer. */
1768 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_RESTART, 0,
1769 new_asoc->c.sinit_num_ostreams,
1770 new_asoc->c.sinit_max_instreams,
Vlad Yasevicha5a35e72007-03-23 11:34:08 -07001771 NULL, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001772 if (!ev)
1773 goto nomem_ev;
1774
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001775 /* Update the content of current association. */
1776 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001777 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
Xufeng Zhang9839ff02013-01-23 16:44:34 +00001778 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1779 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1780 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001781 return SCTP_DISPOSITION_CONSUME;
1782
1783nomem_ev:
1784 sctp_chunk_free(repl);
1785nomem:
1786 return SCTP_DISPOSITION_NOMEM;
1787}
1788
1789/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B')
1790 *
1791 * Section 5.2.4
1792 * B) In this case, both sides may be attempting to start an association
1793 * at about the same time but the peer endpoint started its INIT
1794 * after responding to the local endpoint's INIT
1795 */
1796/* This case represents an initialization collision. */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00001797static sctp_disposition_t sctp_sf_do_dupcook_b(struct net *net,
1798 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001799 const struct sctp_association *asoc,
1800 struct sctp_chunk *chunk,
1801 sctp_cmd_seq_t *commands,
1802 struct sctp_association *new_asoc)
1803{
1804 sctp_init_chunk_t *peer_init;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001805 struct sctp_chunk *repl;
1806
1807 /* new_asoc is a brand-new association, so these are not yet
1808 * side effects--it is safe to run them here.
1809 */
1810 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
Wei Yongjunde6becd2011-04-19 21:30:51 +00001811 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), peer_init,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001812 GFP_ATOMIC))
1813 goto nomem;
1814
1815 /* Update the content of current association. */
1816 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1817 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1818 SCTP_STATE(SCTP_STATE_ESTABLISHED));
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00001819 SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001820 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
1821
1822 repl = sctp_make_cookie_ack(new_asoc, chunk);
1823 if (!repl)
1824 goto nomem;
1825
1826 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001827
1828 /* RFC 2960 5.1 Normal Establishment of an Association
1829 *
1830 * D) IMPLEMENTATION NOTE: An implementation may choose to
1831 * send the Communication Up notification to the SCTP user
1832 * upon reception of a valid COOKIE ECHO chunk.
Vlad Yasevich07d93962007-05-04 13:55:27 -07001833 *
1834 * Sadly, this needs to be implemented as a side-effect, because
1835 * we are not guaranteed to have set the association id of the real
1836 * association and so these notifications need to be delayed until
1837 * the association id is allocated.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001838 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001839
Vlad Yasevich07d93962007-05-04 13:55:27 -07001840 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_CHANGE, SCTP_U8(SCTP_COMM_UP));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001841
1842 /* Sockets API Draft Section 5.3.1.6
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -08001843 * When a peer sends a Adaptation Layer Indication parameter , SCTP
Linus Torvalds1da177e2005-04-16 15:20:36 -07001844 * delivers this notification to inform the application that of the
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -08001845 * peers requested adaptation layer.
Vlad Yasevich07d93962007-05-04 13:55:27 -07001846 *
1847 * This also needs to be done as a side effect for the same reason as
1848 * above.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001849 */
Vlad Yasevich07d93962007-05-04 13:55:27 -07001850 if (asoc->peer.adaptation_ind)
1851 sctp_add_cmd_sf(commands, SCTP_CMD_ADAPTATION_IND, SCTP_NULL());
Linus Torvalds1da177e2005-04-16 15:20:36 -07001852
1853 return SCTP_DISPOSITION_CONSUME;
1854
Linus Torvalds1da177e2005-04-16 15:20:36 -07001855nomem:
1856 return SCTP_DISPOSITION_NOMEM;
1857}
1858
1859/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C')
1860 *
1861 * Section 5.2.4
1862 * C) In this case, the local endpoint's cookie has arrived late.
1863 * Before it arrived, the local endpoint sent an INIT and received an
1864 * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag
1865 * but a new tag of its own.
1866 */
1867/* This case represents an initialization collision. */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00001868static sctp_disposition_t sctp_sf_do_dupcook_c(struct net *net,
1869 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001870 const struct sctp_association *asoc,
1871 struct sctp_chunk *chunk,
1872 sctp_cmd_seq_t *commands,
1873 struct sctp_association *new_asoc)
1874{
1875 /* The cookie should be silently discarded.
1876 * The endpoint SHOULD NOT change states and should leave
1877 * any timers running.
1878 */
1879 return SCTP_DISPOSITION_DISCARD;
1880}
1881
1882/* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D')
1883 *
1884 * Section 5.2.4
1885 *
1886 * D) When both local and remote tags match the endpoint should always
1887 * enter the ESTABLISHED state, if it has not already done so.
1888 */
1889/* This case represents an initialization collision. */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00001890static sctp_disposition_t sctp_sf_do_dupcook_d(struct net *net,
1891 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001892 const struct sctp_association *asoc,
1893 struct sctp_chunk *chunk,
1894 sctp_cmd_seq_t *commands,
1895 struct sctp_association *new_asoc)
1896{
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001897 struct sctp_ulpevent *ev = NULL, *ai_ev = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001898 struct sctp_chunk *repl;
1899
1900 /* Clarification from Implementor's Guide:
1901 * D) When both local and remote tags match the endpoint should
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001902 * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state.
1903 * It should stop any cookie timer that may be running and send
1904 * a COOKIE ACK.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001905 */
1906
1907 /* Don't accidentally move back into established state. */
1908 if (asoc->state < SCTP_STATE_ESTABLISHED) {
1909 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1910 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1911 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1912 SCTP_STATE(SCTP_STATE_ESTABLISHED));
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00001913 SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001914 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START,
1915 SCTP_NULL());
1916
1917 /* RFC 2960 5.1 Normal Establishment of an Association
1918 *
1919 * D) IMPLEMENTATION NOTE: An implementation may choose
1920 * to send the Communication Up notification to the
1921 * SCTP user upon reception of a valid COOKIE
1922 * ECHO chunk.
1923 */
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001924 ev = sctp_ulpevent_make_assoc_change(asoc, 0,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001925 SCTP_COMM_UP, 0,
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001926 asoc->c.sinit_num_ostreams,
1927 asoc->c.sinit_max_instreams,
YOSHIFUJI Hideaki9cbcbf42007-07-19 10:44:50 +09001928 NULL, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001929 if (!ev)
1930 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001931
1932 /* Sockets API Draft Section 5.3.1.6
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -08001933 * When a peer sends a Adaptation Layer Indication parameter,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001934 * SCTP delivers this notification to inform the application
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -08001935 * that of the peers requested adaptation layer.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001936 */
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -08001937 if (asoc->peer.adaptation_ind) {
1938 ai_ev = sctp_ulpevent_make_adaptation_indication(asoc,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001939 GFP_ATOMIC);
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001940 if (!ai_ev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001941 goto nomem;
1942
Linus Torvalds1da177e2005-04-16 15:20:36 -07001943 }
1944 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001945
1946 repl = sctp_make_cookie_ack(new_asoc, chunk);
1947 if (!repl)
1948 goto nomem;
1949
Vlad Yasevich2e3216c2008-06-19 16:08:18 -07001950 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1951
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001952 if (ev)
1953 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1954 SCTP_ULPEVENT(ev));
1955 if (ai_ev)
1956 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1957 SCTP_ULPEVENT(ai_ev));
1958
Linus Torvalds1da177e2005-04-16 15:20:36 -07001959 return SCTP_DISPOSITION_CONSUME;
1960
1961nomem:
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001962 if (ai_ev)
1963 sctp_ulpevent_free(ai_ev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001964 if (ev)
1965 sctp_ulpevent_free(ev);
1966 return SCTP_DISPOSITION_NOMEM;
1967}
1968
1969/*
1970 * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying
1971 * chunk was retransmitted and then delayed in the network.
1972 *
1973 * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists
1974 *
1975 * Verification Tag: None. Do cookie validation.
1976 *
1977 * Inputs
1978 * (endpoint, asoc, chunk)
1979 *
1980 * Outputs
1981 * (asoc, reply_msg, msg_up, timers, counters)
1982 *
1983 * The return value is the disposition of the chunk.
1984 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00001985sctp_disposition_t sctp_sf_do_5_2_4_dupcook(struct net *net,
1986 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001987 const struct sctp_association *asoc,
1988 const sctp_subtype_t type,
1989 void *arg,
1990 sctp_cmd_seq_t *commands)
1991{
1992 sctp_disposition_t retval;
1993 struct sctp_chunk *chunk = arg;
1994 struct sctp_association *new_asoc;
1995 int error = 0;
1996 char action;
1997 struct sctp_chunk *err_chk_p;
1998
1999 /* Make sure that the chunk has a valid length from the protocol
2000 * perspective. In this case check to make sure we have at least
2001 * enough for the chunk header. Cookie length verification is
2002 * done later.
2003 */
2004 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002005 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002006 commands);
2007
2008 /* "Decode" the chunk. We have no optional parameters so we
2009 * are in good shape.
2010 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002011 chunk->subh.cookie_hdr = (struct sctp_signed_cookie *)chunk->skb->data;
Sridhar Samudrala62b08082006-05-05 17:04:43 -07002012 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
2013 sizeof(sctp_chunkhdr_t)))
2014 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002015
2016 /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
2017 * of a duplicate COOKIE ECHO match the Verification Tags of the
2018 * current association, consider the State Cookie valid even if
2019 * the lifespan is exceeded.
2020 */
2021 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
2022 &err_chk_p);
2023
2024 /* FIXME:
2025 * If the re-build failed, what is the proper error path
2026 * from here?
2027 *
2028 * [We should abort the association. --piggy]
2029 */
2030 if (!new_asoc) {
2031 /* FIXME: Several errors are possible. A bad cookie should
2032 * be silently discarded, but think about logging it too.
2033 */
2034 switch (error) {
2035 case -SCTP_IERROR_NOMEM:
2036 goto nomem;
2037
2038 case -SCTP_IERROR_STALE_COOKIE:
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002039 sctp_send_stale_cookie_err(net, ep, asoc, chunk, commands,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002040 err_chk_p);
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002041 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002042 case -SCTP_IERROR_BAD_SIG:
2043 default:
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002044 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07002045 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002046 }
2047
2048 /* Compare the tie_tag in cookie with the verification tag of
2049 * current association.
2050 */
2051 action = sctp_tietags_compare(new_asoc, asoc);
2052
2053 switch (action) {
2054 case 'A': /* Association restart. */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002055 retval = sctp_sf_do_dupcook_a(net, ep, asoc, chunk, commands,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002056 new_asoc);
2057 break;
2058
2059 case 'B': /* Collision case B. */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002060 retval = sctp_sf_do_dupcook_b(net, ep, asoc, chunk, commands,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002061 new_asoc);
2062 break;
2063
2064 case 'C': /* Collision case C. */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002065 retval = sctp_sf_do_dupcook_c(net, ep, asoc, chunk, commands,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002066 new_asoc);
2067 break;
2068
2069 case 'D': /* Collision case D. */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002070 retval = sctp_sf_do_dupcook_d(net, ep, asoc, chunk, commands,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002071 new_asoc);
2072 break;
2073
2074 default: /* Discard packet for all others. */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002075 retval = sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002076 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07002077 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002078
2079 /* Delete the tempory new association. */
Vlad Yasevichf2815632013-03-12 15:53:23 +00002080 sctp_add_cmd_sf(commands, SCTP_CMD_SET_ASOC, SCTP_ASOC(new_asoc));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002081 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
2082
Max Matveevd5ccd492011-08-29 21:02:24 +00002083 /* Restore association pointer to provide SCTP command interpeter
2084 * with a valid context in case it needs to manipulate
2085 * the queues */
2086 sctp_add_cmd_sf(commands, SCTP_CMD_SET_ASOC,
2087 SCTP_ASOC((struct sctp_association *)asoc));
2088
Linus Torvalds1da177e2005-04-16 15:20:36 -07002089 return retval;
2090
2091nomem:
2092 return SCTP_DISPOSITION_NOMEM;
2093}
2094
2095/*
2096 * Process an ABORT. (SHUTDOWN-PENDING state)
2097 *
2098 * See sctp_sf_do_9_1_abort().
2099 */
2100sctp_disposition_t sctp_sf_shutdown_pending_abort(
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002101 struct net *net,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002102 const struct sctp_endpoint *ep,
2103 const struct sctp_association *asoc,
2104 const sctp_subtype_t type,
2105 void *arg,
2106 sctp_cmd_seq_t *commands)
2107{
2108 struct sctp_chunk *chunk = arg;
2109
2110 if (!sctp_vtag_verify_either(chunk, asoc))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002111 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002112
2113 /* Make sure that the ABORT chunk has a valid length.
2114 * Since this is an ABORT chunk, we have to discard it
2115 * because of the following text:
2116 * RFC 2960, Section 3.3.7
2117 * If an endpoint receives an ABORT with a format error or for an
2118 * association that doesn't exist, it MUST silently discard it.
Lucas De Marchi25985ed2011-03-30 22:57:33 -03002119 * Because the length is "invalid", we can't really discard just
Linus Torvalds1da177e2005-04-16 15:20:36 -07002120 * as we do not know its true length. So, to be safe, discard the
2121 * packet.
2122 */
2123 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002124 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002125
Vlad Yasevich75205f42007-12-20 14:12:59 -08002126 /* ADD-IP: Special case for ABORT chunks
2127 * F4) One special consideration is that ABORT Chunks arriving
2128 * destined to the IP address being deleted MUST be
2129 * ignored (see Section 5.3.1 for further details).
2130 */
2131 if (SCTP_ADDR_DEL ==
2132 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002133 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
Vlad Yasevich75205f42007-12-20 14:12:59 -08002134
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002135 return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002136}
2137
2138/*
2139 * Process an ABORT. (SHUTDOWN-SENT state)
2140 *
2141 * See sctp_sf_do_9_1_abort().
2142 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002143sctp_disposition_t sctp_sf_shutdown_sent_abort(struct net *net,
2144 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002145 const struct sctp_association *asoc,
2146 const sctp_subtype_t type,
2147 void *arg,
2148 sctp_cmd_seq_t *commands)
2149{
2150 struct sctp_chunk *chunk = arg;
2151
2152 if (!sctp_vtag_verify_either(chunk, asoc))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002153 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002154
2155 /* Make sure that the ABORT chunk has a valid length.
2156 * Since this is an ABORT chunk, we have to discard it
2157 * because of the following text:
2158 * RFC 2960, Section 3.3.7
2159 * If an endpoint receives an ABORT with a format error or for an
2160 * association that doesn't exist, it MUST silently discard it.
Lucas De Marchi25985ed2011-03-30 22:57:33 -03002161 * Because the length is "invalid", we can't really discard just
Linus Torvalds1da177e2005-04-16 15:20:36 -07002162 * as we do not know its true length. So, to be safe, discard the
2163 * packet.
2164 */
2165 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002166 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002167
Vlad Yasevich75205f42007-12-20 14:12:59 -08002168 /* ADD-IP: Special case for ABORT chunks
2169 * F4) One special consideration is that ABORT Chunks arriving
2170 * destined to the IP address being deleted MUST be
2171 * ignored (see Section 5.3.1 for further details).
2172 */
2173 if (SCTP_ADDR_DEL ==
2174 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002175 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
Vlad Yasevich75205f42007-12-20 14:12:59 -08002176
Linus Torvalds1da177e2005-04-16 15:20:36 -07002177 /* Stop the T2-shutdown timer. */
2178 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2179 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2180
2181 /* Stop the T5-shutdown guard timer. */
2182 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2183 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
2184
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002185 return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002186}
2187
2188/*
2189 * Process an ABORT. (SHUTDOWN-ACK-SENT state)
2190 *
2191 * See sctp_sf_do_9_1_abort().
2192 */
2193sctp_disposition_t sctp_sf_shutdown_ack_sent_abort(
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002194 struct net *net,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002195 const struct sctp_endpoint *ep,
2196 const struct sctp_association *asoc,
2197 const sctp_subtype_t type,
2198 void *arg,
2199 sctp_cmd_seq_t *commands)
2200{
2201 /* The same T2 timer, so we should be able to use
2202 * common function with the SHUTDOWN-SENT state.
2203 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002204 return sctp_sf_shutdown_sent_abort(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002205}
2206
2207/*
2208 * Handle an Error received in COOKIE_ECHOED state.
2209 *
2210 * Only handle the error type of stale COOKIE Error, the other errors will
2211 * be ignored.
2212 *
2213 * Inputs
2214 * (endpoint, asoc, chunk)
2215 *
2216 * Outputs
2217 * (asoc, reply_msg, msg_up, timers, counters)
2218 *
2219 * The return value is the disposition of the chunk.
2220 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002221sctp_disposition_t sctp_sf_cookie_echoed_err(struct net *net,
2222 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002223 const struct sctp_association *asoc,
2224 const sctp_subtype_t type,
2225 void *arg,
2226 sctp_cmd_seq_t *commands)
2227{
2228 struct sctp_chunk *chunk = arg;
2229 sctp_errhdr_t *err;
2230
2231 if (!sctp_vtag_verify(chunk, asoc))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002232 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002233
2234 /* Make sure that the ERROR chunk has a valid length.
2235 * The parameter walking depends on this as well.
2236 */
2237 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002238 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002239 commands);
2240
2241 /* Process the error here */
2242 /* FUTURE FIXME: When PR-SCTP related and other optional
2243 * parms are emitted, this will have to change to handle multiple
2244 * errors.
2245 */
2246 sctp_walk_errors(err, chunk->chunk_hdr) {
2247 if (SCTP_ERROR_STALE_COOKIE == err->cause)
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002248 return sctp_sf_do_5_2_6_stale(net, ep, asoc, type,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002249 arg, commands);
2250 }
2251
2252 /* It is possible to have malformed error causes, and that
2253 * will cause us to end the walk early. However, since
2254 * we are discarding the packet, there should be no adverse
2255 * affects.
2256 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002257 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002258}
2259
2260/*
2261 * Handle a Stale COOKIE Error
2262 *
2263 * Section: 5.2.6 Handle Stale COOKIE Error
2264 * If the association is in the COOKIE-ECHOED state, the endpoint may elect
2265 * one of the following three alternatives.
2266 * ...
2267 * 3) Send a new INIT chunk to the endpoint, adding a Cookie
2268 * Preservative parameter requesting an extension to the lifetime of
2269 * the State Cookie. When calculating the time extension, an
2270 * implementation SHOULD use the RTT information measured based on the
2271 * previous COOKIE ECHO / ERROR exchange, and should add no more
2272 * than 1 second beyond the measured RTT, due to long State Cookie
2273 * lifetimes making the endpoint more subject to a replay attack.
2274 *
2275 * Verification Tag: Not explicit, but safe to ignore.
2276 *
2277 * Inputs
2278 * (endpoint, asoc, chunk)
2279 *
2280 * Outputs
2281 * (asoc, reply_msg, msg_up, timers, counters)
2282 *
2283 * The return value is the disposition of the chunk.
2284 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002285static sctp_disposition_t sctp_sf_do_5_2_6_stale(struct net *net,
2286 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002287 const struct sctp_association *asoc,
2288 const sctp_subtype_t type,
2289 void *arg,
2290 sctp_cmd_seq_t *commands)
2291{
2292 struct sctp_chunk *chunk = arg;
2293 time_t stale;
2294 sctp_cookie_preserve_param_t bht;
2295 sctp_errhdr_t *err;
2296 struct sctp_chunk *reply;
2297 struct sctp_bind_addr *bp;
Frank Filz3f7a87d2005-06-20 13:14:57 -07002298 int attempts = asoc->init_err_counter + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002299
Vlad Yasevich81845c22006-01-30 15:59:54 -08002300 if (attempts > asoc->max_init_attempts) {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002301 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
2302 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002303 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08002304 SCTP_PERR(SCTP_ERROR_STALE_COOKIE));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002305 return SCTP_DISPOSITION_DELETE_TCB;
2306 }
2307
2308 err = (sctp_errhdr_t *)(chunk->skb->data);
2309
2310 /* When calculating the time extension, an implementation
2311 * SHOULD use the RTT information measured based on the
2312 * previous COOKIE ECHO / ERROR exchange, and should add no
2313 * more than 1 second beyond the measured RTT, due to long
2314 * State Cookie lifetimes making the endpoint more subject to
2315 * a replay attack.
2316 * Measure of Staleness's unit is usec. (1/1000000 sec)
2317 * Suggested Cookie Life-span Increment's unit is msec.
2318 * (1/1000 sec)
2319 * In general, if you use the suggested cookie life, the value
2320 * found in the field of measure of staleness should be doubled
2321 * to give ample time to retransmit the new cookie and thus
2322 * yield a higher probability of success on the reattempt.
2323 */
Al Viro34bcca22006-11-20 17:27:15 -08002324 stale = ntohl(*(__be32 *)((u8 *)err + sizeof(sctp_errhdr_t)));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002325 stale = (stale * 2) / 1000;
2326
2327 bht.param_hdr.type = SCTP_PARAM_COOKIE_PRESERVATIVE;
2328 bht.param_hdr.length = htons(sizeof(bht));
2329 bht.lifespan_increment = htonl(stale);
2330
2331 /* Build that new INIT chunk. */
2332 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
2333 reply = sctp_make_init(asoc, bp, GFP_ATOMIC, sizeof(bht));
2334 if (!reply)
2335 goto nomem;
2336
2337 sctp_addto_chunk(reply, sizeof(bht), &bht);
2338
2339 /* Clear peer's init_tag cached in assoc as we are sending a new INIT */
2340 sctp_add_cmd_sf(commands, SCTP_CMD_CLEAR_INIT_TAG, SCTP_NULL());
2341
2342 /* Stop pending T3-rtx and heartbeat timers */
2343 sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
2344 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
2345
2346 /* Delete non-primary peer ip addresses since we are transitioning
2347 * back to the COOKIE-WAIT state
2348 */
2349 sctp_add_cmd_sf(commands, SCTP_CMD_DEL_NON_PRIMARY, SCTP_NULL());
2350
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002351 /* If we've sent any data bundled with COOKIE-ECHO we will need to
2352 * resend
Linus Torvalds1da177e2005-04-16 15:20:36 -07002353 */
Vlad Yasevichb6157d82007-10-24 15:59:16 -04002354 sctp_add_cmd_sf(commands, SCTP_CMD_T1_RETRAN,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002355 SCTP_TRANSPORT(asoc->peer.primary_path));
2356
2357 /* Cast away the const modifier, as we want to just
2358 * rerun it through as a sideffect.
2359 */
Frank Filz3f7a87d2005-06-20 13:14:57 -07002360 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_INC, SCTP_NULL());
Linus Torvalds1da177e2005-04-16 15:20:36 -07002361
2362 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2363 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
2364 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2365 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
2366 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
2367 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
2368
2369 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2370
2371 return SCTP_DISPOSITION_CONSUME;
2372
2373nomem:
2374 return SCTP_DISPOSITION_NOMEM;
2375}
2376
2377/*
2378 * Process an ABORT.
2379 *
2380 * Section: 9.1
2381 * After checking the Verification Tag, the receiving endpoint shall
2382 * remove the association from its record, and shall report the
2383 * termination to its upper layer.
2384 *
2385 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
2386 * B) Rules for packet carrying ABORT:
2387 *
2388 * - The endpoint shall always fill in the Verification Tag field of the
2389 * outbound packet with the destination endpoint's tag value if it
2390 * is known.
2391 *
2392 * - If the ABORT is sent in response to an OOTB packet, the endpoint
2393 * MUST follow the procedure described in Section 8.4.
2394 *
2395 * - The receiver MUST accept the packet if the Verification Tag
2396 * matches either its own tag, OR the tag of its peer. Otherwise, the
2397 * receiver MUST silently discard the packet and take no further
2398 * action.
2399 *
2400 * Inputs
2401 * (endpoint, asoc, chunk)
2402 *
2403 * Outputs
2404 * (asoc, reply_msg, msg_up, timers, counters)
2405 *
2406 * The return value is the disposition of the chunk.
2407 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002408sctp_disposition_t sctp_sf_do_9_1_abort(struct net *net,
2409 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002410 const struct sctp_association *asoc,
2411 const sctp_subtype_t type,
2412 void *arg,
2413 sctp_cmd_seq_t *commands)
2414{
2415 struct sctp_chunk *chunk = arg;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002416
2417 if (!sctp_vtag_verify_either(chunk, asoc))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002418 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002419
2420 /* Make sure that the ABORT chunk has a valid length.
2421 * Since this is an ABORT chunk, we have to discard it
2422 * because of the following text:
2423 * RFC 2960, Section 3.3.7
2424 * If an endpoint receives an ABORT with a format error or for an
2425 * association that doesn't exist, it MUST silently discard it.
Lucas De Marchi25985ed2011-03-30 22:57:33 -03002426 * Because the length is "invalid", we can't really discard just
Linus Torvalds1da177e2005-04-16 15:20:36 -07002427 * as we do not know its true length. So, to be safe, discard the
2428 * packet.
2429 */
2430 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002431 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002432
Vlad Yasevich75205f42007-12-20 14:12:59 -08002433 /* ADD-IP: Special case for ABORT chunks
2434 * F4) One special consideration is that ABORT Chunks arriving
2435 * destined to the IP address being deleted MUST be
2436 * ignored (see Section 5.3.1 for further details).
2437 */
2438 if (SCTP_ADDR_DEL ==
2439 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002440 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
Vlad Yasevich75205f42007-12-20 14:12:59 -08002441
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002442 return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands);
Vlad Yasevich75205f42007-12-20 14:12:59 -08002443}
2444
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002445static sctp_disposition_t __sctp_sf_do_9_1_abort(struct net *net,
2446 const struct sctp_endpoint *ep,
Vlad Yasevich75205f42007-12-20 14:12:59 -08002447 const struct sctp_association *asoc,
2448 const sctp_subtype_t type,
2449 void *arg,
2450 sctp_cmd_seq_t *commands)
2451{
2452 struct sctp_chunk *chunk = arg;
Eric Dumazet95c96172012-04-15 05:58:06 +00002453 unsigned int len;
Vlad Yasevich75205f42007-12-20 14:12:59 -08002454 __be16 error = SCTP_ERROR_NO_ERROR;
2455
Linus Torvalds1da177e2005-04-16 15:20:36 -07002456 /* See if we have an error cause code in the chunk. */
2457 len = ntohs(chunk->chunk_hdr->length);
Shan Wei96ca4682011-04-19 21:26:26 +00002458 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr)) {
2459
2460 sctp_errhdr_t *err;
2461 sctp_walk_errors(err, chunk->chunk_hdr);
2462 if ((void *)err != (void *)chunk->chunk_end)
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002463 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Shan Wei96ca4682011-04-19 21:26:26 +00002464
Linus Torvalds1da177e2005-04-16 15:20:36 -07002465 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
Shan Wei96ca4682011-04-19 21:26:26 +00002466 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002467
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002468 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNRESET));
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002469 /* ASSOC_FAILED will DELETE_TCB. */
Al Viro5be291f2006-11-20 17:01:06 -08002470 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, SCTP_PERR(error));
Eric W. Biedermanb01a2402012-08-06 08:47:55 +00002471 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
2472 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002473
2474 return SCTP_DISPOSITION_ABORT;
2475}
2476
2477/*
2478 * Process an ABORT. (COOKIE-WAIT state)
2479 *
2480 * See sctp_sf_do_9_1_abort() above.
2481 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002482sctp_disposition_t sctp_sf_cookie_wait_abort(struct net *net,
2483 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002484 const struct sctp_association *asoc,
2485 const sctp_subtype_t type,
2486 void *arg,
2487 sctp_cmd_seq_t *commands)
2488{
2489 struct sctp_chunk *chunk = arg;
Eric Dumazet95c96172012-04-15 05:58:06 +00002490 unsigned int len;
Al Virof94c0192006-11-20 17:00:25 -08002491 __be16 error = SCTP_ERROR_NO_ERROR;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002492
2493 if (!sctp_vtag_verify_either(chunk, asoc))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002494 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002495
2496 /* Make sure that the ABORT chunk has a valid length.
2497 * Since this is an ABORT chunk, we have to discard it
2498 * because of the following text:
2499 * RFC 2960, Section 3.3.7
2500 * If an endpoint receives an ABORT with a format error or for an
2501 * association that doesn't exist, it MUST silently discard it.
Lucas De Marchi25985ed2011-03-30 22:57:33 -03002502 * Because the length is "invalid", we can't really discard just
Linus Torvalds1da177e2005-04-16 15:20:36 -07002503 * as we do not know its true length. So, to be safe, discard the
2504 * packet.
2505 */
2506 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002507 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002508
2509 /* See if we have an error cause code in the chunk. */
2510 len = ntohs(chunk->chunk_hdr->length);
2511 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
2512 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2513
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002514 return sctp_stop_t1_and_abort(net, commands, error, ECONNREFUSED, asoc,
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002515 chunk->transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002516}
2517
2518/*
2519 * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state)
2520 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002521sctp_disposition_t sctp_sf_cookie_wait_icmp_abort(struct net *net,
2522 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002523 const struct sctp_association *asoc,
2524 const sctp_subtype_t type,
2525 void *arg,
2526 sctp_cmd_seq_t *commands)
2527{
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002528 return sctp_stop_t1_and_abort(net, commands, SCTP_ERROR_NO_ERROR,
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002529 ENOPROTOOPT, asoc,
Frank Filz3f7a87d2005-06-20 13:14:57 -07002530 (struct sctp_transport *)arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002531}
2532
2533/*
2534 * Process an ABORT. (COOKIE-ECHOED state)
2535 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002536sctp_disposition_t sctp_sf_cookie_echoed_abort(struct net *net,
2537 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002538 const struct sctp_association *asoc,
2539 const sctp_subtype_t type,
2540 void *arg,
2541 sctp_cmd_seq_t *commands)
2542{
2543 /* There is a single T1 timer, so we should be able to use
2544 * common function with the COOKIE-WAIT state.
2545 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002546 return sctp_sf_cookie_wait_abort(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002547}
2548
2549/*
2550 * Stop T1 timer and abort association with "INIT failed".
2551 *
2552 * This is common code called by several sctp_sf_*_abort() functions above.
2553 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002554static sctp_disposition_t sctp_stop_t1_and_abort(struct net *net,
2555 sctp_cmd_seq_t *commands,
Al Virof94c0192006-11-20 17:00:25 -08002556 __be16 error, int sk_err,
Frank Filz3f7a87d2005-06-20 13:14:57 -07002557 const struct sctp_association *asoc,
2558 struct sctp_transport *transport)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002559{
Daniel Borkmannbb333812013-06-28 19:49:40 +02002560 pr_debug("%s: ABORT received (INIT)\n", __func__);
2561
Linus Torvalds1da177e2005-04-16 15:20:36 -07002562 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2563 SCTP_STATE(SCTP_STATE_CLOSED));
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002564 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002565 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2566 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002567 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(sk_err));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002568 /* CMD_INIT_FAILED will DELETE_TCB. */
2569 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08002570 SCTP_PERR(error));
Daniel Borkmannbb333812013-06-28 19:49:40 +02002571
Frank Filz3f7a87d2005-06-20 13:14:57 -07002572 return SCTP_DISPOSITION_ABORT;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002573}
2574
2575/*
2576 * sctp_sf_do_9_2_shut
2577 *
2578 * Section: 9.2
2579 * Upon the reception of the SHUTDOWN, the peer endpoint shall
2580 * - enter the SHUTDOWN-RECEIVED state,
2581 *
2582 * - stop accepting new data from its SCTP user
2583 *
2584 * - verify, by checking the Cumulative TSN Ack field of the chunk,
2585 * that all its outstanding DATA chunks have been received by the
2586 * SHUTDOWN sender.
2587 *
2588 * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT
2589 * send a SHUTDOWN in response to a ULP request. And should discard
2590 * subsequent SHUTDOWN chunks.
2591 *
2592 * If there are still outstanding DATA chunks left, the SHUTDOWN
2593 * receiver shall continue to follow normal data transmission
2594 * procedures defined in Section 6 until all outstanding DATA chunks
2595 * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept
2596 * new data from its SCTP user.
2597 *
2598 * Verification Tag: 8.5 Verification Tag [Normal verification]
2599 *
2600 * Inputs
2601 * (endpoint, asoc, chunk)
2602 *
2603 * Outputs
2604 * (asoc, reply_msg, msg_up, timers, counters)
2605 *
2606 * The return value is the disposition of the chunk.
2607 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002608sctp_disposition_t sctp_sf_do_9_2_shutdown(struct net *net,
2609 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002610 const struct sctp_association *asoc,
2611 const sctp_subtype_t type,
2612 void *arg,
2613 sctp_cmd_seq_t *commands)
2614{
2615 struct sctp_chunk *chunk = arg;
2616 sctp_shutdownhdr_t *sdh;
2617 sctp_disposition_t disposition;
2618 struct sctp_ulpevent *ev;
Wei Yongjundf10eec2008-10-23 01:00:21 -07002619 __u32 ctsn;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002620
2621 if (!sctp_vtag_verify(chunk, asoc))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002622 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002623
2624 /* Make sure that the SHUTDOWN chunk has a valid length. */
2625 if (!sctp_chunk_length_valid(chunk,
2626 sizeof(struct sctp_shutdown_chunk_t)))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002627 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002628 commands);
2629
2630 /* Convert the elaborate header. */
2631 sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
2632 skb_pull(chunk->skb, sizeof(sctp_shutdownhdr_t));
2633 chunk->subh.shutdown_hdr = sdh;
Wei Yongjundf10eec2008-10-23 01:00:21 -07002634 ctsn = ntohl(sdh->cum_tsn_ack);
2635
Wei Yongjuna2f36ee2009-08-22 11:24:00 +08002636 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
Daniel Borkmannbb333812013-06-28 19:49:40 +02002637 pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn,
2638 asoc->ctsn_ack_point);
2639
Wei Yongjuna2f36ee2009-08-22 11:24:00 +08002640 return SCTP_DISPOSITION_DISCARD;
2641 }
2642
Wei Yongjundf10eec2008-10-23 01:00:21 -07002643 /* If Cumulative TSN Ack beyond the max tsn currently
2644 * send, terminating the association and respond to the
2645 * sender with an ABORT.
2646 */
2647 if (!TSN_lt(ctsn, asoc->next_tsn))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002648 return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002649
Sridhar Samudralaeb0e0072005-09-22 23:48:38 -07002650 /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT
2651 * When a peer sends a SHUTDOWN, SCTP delivers this notification to
2652 * inform the application that it should cease sending data.
2653 */
2654 ev = sctp_ulpevent_make_shutdown_event(asoc, 0, GFP_ATOMIC);
2655 if (!ev) {
2656 disposition = SCTP_DISPOSITION_NOMEM;
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002657 goto out;
Sridhar Samudralaeb0e0072005-09-22 23:48:38 -07002658 }
2659 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
2660
Linus Torvalds1da177e2005-04-16 15:20:36 -07002661 /* Upon the reception of the SHUTDOWN, the peer endpoint shall
2662 * - enter the SHUTDOWN-RECEIVED state,
2663 * - stop accepting new data from its SCTP user
2664 *
2665 * [This is implicit in the new state.]
2666 */
2667 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2668 SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED));
2669 disposition = SCTP_DISPOSITION_CONSUME;
2670
2671 if (sctp_outq_is_empty(&asoc->outqueue)) {
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002672 disposition = sctp_sf_do_9_2_shutdown_ack(net, ep, asoc, type,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002673 arg, commands);
2674 }
2675
2676 if (SCTP_DISPOSITION_NOMEM == disposition)
2677 goto out;
2678
2679 /* - verify, by checking the Cumulative TSN Ack field of the
2680 * chunk, that all its outstanding DATA chunks have been
2681 * received by the SHUTDOWN sender.
2682 */
2683 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
Al Viro2178eda2006-11-20 17:26:53 -08002684 SCTP_BE32(chunk->subh.shutdown_hdr->cum_tsn_ack));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002685
Linus Torvalds1da177e2005-04-16 15:20:36 -07002686out:
2687 return disposition;
2688}
2689
Wei Yongjun2e3f92d2008-10-23 01:01:18 -07002690/*
2691 * sctp_sf_do_9_2_shut_ctsn
2692 *
2693 * Once an endpoint has reached the SHUTDOWN-RECEIVED state,
2694 * it MUST NOT send a SHUTDOWN in response to a ULP request.
2695 * The Cumulative TSN Ack of the received SHUTDOWN chunk
2696 * MUST be processed.
2697 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002698sctp_disposition_t sctp_sf_do_9_2_shut_ctsn(struct net *net,
2699 const struct sctp_endpoint *ep,
Wei Yongjun2e3f92d2008-10-23 01:01:18 -07002700 const struct sctp_association *asoc,
2701 const sctp_subtype_t type,
2702 void *arg,
2703 sctp_cmd_seq_t *commands)
2704{
2705 struct sctp_chunk *chunk = arg;
2706 sctp_shutdownhdr_t *sdh;
Wei Yongjuna2f36ee2009-08-22 11:24:00 +08002707 __u32 ctsn;
Wei Yongjun2e3f92d2008-10-23 01:01:18 -07002708
2709 if (!sctp_vtag_verify(chunk, asoc))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002710 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Wei Yongjun2e3f92d2008-10-23 01:01:18 -07002711
2712 /* Make sure that the SHUTDOWN chunk has a valid length. */
2713 if (!sctp_chunk_length_valid(chunk,
2714 sizeof(struct sctp_shutdown_chunk_t)))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002715 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
Wei Yongjun2e3f92d2008-10-23 01:01:18 -07002716 commands);
2717
2718 sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
Wei Yongjuna2f36ee2009-08-22 11:24:00 +08002719 ctsn = ntohl(sdh->cum_tsn_ack);
2720
2721 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
Daniel Borkmannbb333812013-06-28 19:49:40 +02002722 pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn,
2723 asoc->ctsn_ack_point);
2724
Wei Yongjuna2f36ee2009-08-22 11:24:00 +08002725 return SCTP_DISPOSITION_DISCARD;
2726 }
Wei Yongjun2e3f92d2008-10-23 01:01:18 -07002727
2728 /* If Cumulative TSN Ack beyond the max tsn currently
2729 * send, terminating the association and respond to the
2730 * sender with an ABORT.
2731 */
Wei Yongjuna2f36ee2009-08-22 11:24:00 +08002732 if (!TSN_lt(ctsn, asoc->next_tsn))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002733 return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands);
Wei Yongjun2e3f92d2008-10-23 01:01:18 -07002734
2735 /* verify, by checking the Cumulative TSN Ack field of the
2736 * chunk, that all its outstanding DATA chunks have been
2737 * received by the SHUTDOWN sender.
2738 */
2739 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
2740 SCTP_BE32(sdh->cum_tsn_ack));
2741
2742 return SCTP_DISPOSITION_CONSUME;
2743}
2744
Linus Torvalds1da177e2005-04-16 15:20:36 -07002745/* RFC 2960 9.2
2746 * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk
2747 * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination
2748 * transport addresses (either in the IP addresses or in the INIT chunk)
2749 * that belong to this association, it should discard the INIT chunk and
2750 * retransmit the SHUTDOWN ACK chunk.
2751 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002752sctp_disposition_t sctp_sf_do_9_2_reshutack(struct net *net,
2753 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002754 const struct sctp_association *asoc,
2755 const sctp_subtype_t type,
2756 void *arg,
2757 sctp_cmd_seq_t *commands)
2758{
2759 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
2760 struct sctp_chunk *reply;
2761
Vlad Yasevichece25df2007-09-07 16:30:54 -04002762 /* Make sure that the chunk has a valid length */
2763 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002764 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
Vlad Yasevichece25df2007-09-07 16:30:54 -04002765 commands);
2766
Linus Torvalds1da177e2005-04-16 15:20:36 -07002767 /* Since we are not going to really process this INIT, there
2768 * is no point in verifying chunk boundries. Just generate
2769 * the SHUTDOWN ACK.
2770 */
2771 reply = sctp_make_shutdown_ack(asoc, chunk);
2772 if (NULL == reply)
2773 goto nomem;
2774
2775 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
2776 * the T2-SHUTDOWN timer.
2777 */
2778 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
2779
2780 /* and restart the T2-shutdown timer. */
2781 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2782 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2783
2784 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2785
2786 return SCTP_DISPOSITION_CONSUME;
2787nomem:
2788 return SCTP_DISPOSITION_NOMEM;
2789}
2790
2791/*
2792 * sctp_sf_do_ecn_cwr
2793 *
2794 * Section: Appendix A: Explicit Congestion Notification
2795 *
2796 * CWR:
2797 *
2798 * RFC 2481 details a specific bit for a sender to send in the header of
2799 * its next outbound TCP segment to indicate to its peer that it has
2800 * reduced its congestion window. This is termed the CWR bit. For
2801 * SCTP the same indication is made by including the CWR chunk.
2802 * This chunk contains one data element, i.e. the TSN number that
2803 * was sent in the ECNE chunk. This element represents the lowest
2804 * TSN number in the datagram that was originally marked with the
2805 * CE bit.
2806 *
2807 * Verification Tag: 8.5 Verification Tag [Normal verification]
2808 * Inputs
2809 * (endpoint, asoc, chunk)
2810 *
2811 * Outputs
2812 * (asoc, reply_msg, msg_up, timers, counters)
2813 *
2814 * The return value is the disposition of the chunk.
2815 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002816sctp_disposition_t sctp_sf_do_ecn_cwr(struct net *net,
2817 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002818 const struct sctp_association *asoc,
2819 const sctp_subtype_t type,
2820 void *arg,
2821 sctp_cmd_seq_t *commands)
2822{
2823 sctp_cwrhdr_t *cwr;
2824 struct sctp_chunk *chunk = arg;
Al Viro34bcca22006-11-20 17:27:15 -08002825 u32 lowest_tsn;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002826
2827 if (!sctp_vtag_verify(chunk, asoc))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002828 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002829
2830 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002831 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002832 commands);
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002833
Linus Torvalds1da177e2005-04-16 15:20:36 -07002834 cwr = (sctp_cwrhdr_t *) chunk->skb->data;
2835 skb_pull(chunk->skb, sizeof(sctp_cwrhdr_t));
2836
Al Viro34bcca22006-11-20 17:27:15 -08002837 lowest_tsn = ntohl(cwr->lowest_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002838
2839 /* Does this CWR ack the last sent congestion notification? */
Al Viro34bcca22006-11-20 17:27:15 -08002840 if (TSN_lte(asoc->last_ecne_tsn, lowest_tsn)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002841 /* Stop sending ECNE. */
2842 sctp_add_cmd_sf(commands,
2843 SCTP_CMD_ECN_CWR,
Al Viro34bcca22006-11-20 17:27:15 -08002844 SCTP_U32(lowest_tsn));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002845 }
2846 return SCTP_DISPOSITION_CONSUME;
2847}
2848
2849/*
2850 * sctp_sf_do_ecne
2851 *
2852 * Section: Appendix A: Explicit Congestion Notification
2853 *
2854 * ECN-Echo
2855 *
2856 * RFC 2481 details a specific bit for a receiver to send back in its
2857 * TCP acknowledgements to notify the sender of the Congestion
2858 * Experienced (CE) bit having arrived from the network. For SCTP this
2859 * same indication is made by including the ECNE chunk. This chunk
2860 * contains one data element, i.e. the lowest TSN associated with the IP
2861 * datagram marked with the CE bit.....
2862 *
2863 * Verification Tag: 8.5 Verification Tag [Normal verification]
2864 * Inputs
2865 * (endpoint, asoc, chunk)
2866 *
2867 * Outputs
2868 * (asoc, reply_msg, msg_up, timers, counters)
2869 *
2870 * The return value is the disposition of the chunk.
2871 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002872sctp_disposition_t sctp_sf_do_ecne(struct net *net,
2873 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002874 const struct sctp_association *asoc,
2875 const sctp_subtype_t type,
2876 void *arg,
2877 sctp_cmd_seq_t *commands)
2878{
2879 sctp_ecnehdr_t *ecne;
2880 struct sctp_chunk *chunk = arg;
2881
2882 if (!sctp_vtag_verify(chunk, asoc))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002883 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002884
2885 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002886 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002887 commands);
2888
2889 ecne = (sctp_ecnehdr_t *) chunk->skb->data;
2890 skb_pull(chunk->skb, sizeof(sctp_ecnehdr_t));
2891
2892 /* If this is a newer ECNE than the last CWR packet we sent out */
2893 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_ECNE,
2894 SCTP_U32(ntohl(ecne->lowest_tsn)));
2895
2896 return SCTP_DISPOSITION_CONSUME;
2897}
2898
2899/*
2900 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
2901 *
2902 * The SCTP endpoint MUST always acknowledge the reception of each valid
2903 * DATA chunk.
2904 *
2905 * The guidelines on delayed acknowledgement algorithm specified in
2906 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
2907 * acknowledgement SHOULD be generated for at least every second packet
2908 * (not every second DATA chunk) received, and SHOULD be generated within
2909 * 200 ms of the arrival of any unacknowledged DATA chunk. In some
2910 * situations it may be beneficial for an SCTP transmitter to be more
2911 * conservative than the algorithms detailed in this document allow.
2912 * However, an SCTP transmitter MUST NOT be more aggressive than the
2913 * following algorithms allow.
2914 *
2915 * A SCTP receiver MUST NOT generate more than one SACK for every
2916 * incoming packet, other than to update the offered window as the
2917 * receiving application consumes new data.
2918 *
2919 * Verification Tag: 8.5 Verification Tag [Normal verification]
2920 *
2921 * Inputs
2922 * (endpoint, asoc, chunk)
2923 *
2924 * Outputs
2925 * (asoc, reply_msg, msg_up, timers, counters)
2926 *
2927 * The return value is the disposition of the chunk.
2928 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002929sctp_disposition_t sctp_sf_eat_data_6_2(struct net *net,
2930 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002931 const struct sctp_association *asoc,
2932 const sctp_subtype_t type,
2933 void *arg,
2934 sctp_cmd_seq_t *commands)
2935{
2936 struct sctp_chunk *chunk = arg;
Wei Yongjun6dc76942009-11-23 15:53:53 -05002937 sctp_arg_t force = SCTP_NOFORCE();
Linus Torvalds1da177e2005-04-16 15:20:36 -07002938 int error;
2939
2940 if (!sctp_vtag_verify(chunk, asoc)) {
2941 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
2942 SCTP_NULL());
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002943 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002944 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002945
2946 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002947 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002948 commands);
2949
wangweidongcb3f8372013-12-23 12:16:50 +08002950 error = sctp_eat_data(asoc, chunk, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002951 switch (error) {
2952 case SCTP_IERROR_NO_ERROR:
2953 break;
2954 case SCTP_IERROR_HIGH_TSN:
2955 case SCTP_IERROR_BAD_STREAM:
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002956 SCTP_INC_STATS(net, SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002957 goto discard_noforce;
2958 case SCTP_IERROR_DUP_TSN:
2959 case SCTP_IERROR_IGNORE_TSN:
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002960 SCTP_INC_STATS(net, SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002961 goto discard_force;
2962 case SCTP_IERROR_NO_DATA:
2963 goto consume;
Vlad Yasevichf1751c52009-09-04 18:21:03 -04002964 case SCTP_IERROR_PROTO_VIOLATION:
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00002965 return sctp_sf_abort_violation(net, ep, asoc, chunk, commands,
Vlad Yasevichf1751c52009-09-04 18:21:03 -04002966 (u8 *)chunk->subh.data_hdr, sizeof(sctp_datahdr_t));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002967 default:
2968 BUG();
2969 }
2970
Wei Yongjun6dc76942009-11-23 15:53:53 -05002971 if (chunk->chunk_hdr->flags & SCTP_DATA_SACK_IMM)
2972 force = SCTP_FORCE();
2973
Neil Horman9f70f462013-12-10 06:48:15 -05002974 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002975 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2976 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
2977 }
2978
2979 /* If this is the last chunk in a packet, we need to count it
2980 * toward sack generation. Note that we need to SACK every
2981 * OTHER packet containing data chunks, EVEN IF WE DISCARD
2982 * THEM. We elect to NOT generate SACK's if the chunk fails
2983 * the verification tag test.
2984 *
2985 * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2986 *
2987 * The SCTP endpoint MUST always acknowledge the reception of
2988 * each valid DATA chunk.
2989 *
2990 * The guidelines on delayed acknowledgement algorithm
2991 * specified in Section 4.2 of [RFC2581] SHOULD be followed.
2992 * Specifically, an acknowledgement SHOULD be generated for at
2993 * least every second packet (not every second DATA chunk)
2994 * received, and SHOULD be generated within 200 ms of the
2995 * arrival of any unacknowledged DATA chunk. In some
2996 * situations it may be beneficial for an SCTP transmitter to
2997 * be more conservative than the algorithms detailed in this
2998 * document allow. However, an SCTP transmitter MUST NOT be
2999 * more aggressive than the following algorithms allow.
3000 */
Frank Filz52ccb8e2005-12-22 11:36:46 -08003001 if (chunk->end_of_packet)
Wei Yongjun6dc76942009-11-23 15:53:53 -05003002 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003003
Linus Torvalds1da177e2005-04-16 15:20:36 -07003004 return SCTP_DISPOSITION_CONSUME;
3005
3006discard_force:
3007 /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
3008 *
3009 * When a packet arrives with duplicate DATA chunk(s) and with
3010 * no new DATA chunk(s), the endpoint MUST immediately send a
3011 * SACK with no delay. If a packet arrives with duplicate
3012 * DATA chunk(s) bundled with new DATA chunks, the endpoint
3013 * MAY immediately send a SACK. Normally receipt of duplicate
3014 * DATA chunks will occur when the original SACK chunk was lost
3015 * and the peer's RTO has expired. The duplicate TSN number(s)
3016 * SHOULD be reported in the SACK as duplicate.
3017 */
3018 /* In our case, we split the MAY SACK advice up whether or not
3019 * the last chunk is a duplicate.'
3020 */
3021 if (chunk->end_of_packet)
3022 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3023 return SCTP_DISPOSITION_DISCARD;
3024
3025discard_noforce:
Frank Filz52ccb8e2005-12-22 11:36:46 -08003026 if (chunk->end_of_packet)
Wei Yongjun6dc76942009-11-23 15:53:53 -05003027 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003028
Linus Torvalds1da177e2005-04-16 15:20:36 -07003029 return SCTP_DISPOSITION_DISCARD;
3030consume:
3031 return SCTP_DISPOSITION_CONSUME;
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003032
Linus Torvalds1da177e2005-04-16 15:20:36 -07003033}
3034
3035/*
3036 * sctp_sf_eat_data_fast_4_4
3037 *
3038 * Section: 4 (4)
3039 * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received
3040 * DATA chunks without delay.
3041 *
3042 * Verification Tag: 8.5 Verification Tag [Normal verification]
3043 * Inputs
3044 * (endpoint, asoc, chunk)
3045 *
3046 * Outputs
3047 * (asoc, reply_msg, msg_up, timers, counters)
3048 *
3049 * The return value is the disposition of the chunk.
3050 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003051sctp_disposition_t sctp_sf_eat_data_fast_4_4(struct net *net,
3052 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003053 const struct sctp_association *asoc,
3054 const sctp_subtype_t type,
3055 void *arg,
3056 sctp_cmd_seq_t *commands)
3057{
3058 struct sctp_chunk *chunk = arg;
3059 int error;
3060
3061 if (!sctp_vtag_verify(chunk, asoc)) {
3062 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3063 SCTP_NULL());
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003064 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003065 }
3066
3067 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003068 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003069 commands);
3070
wangweidongcb3f8372013-12-23 12:16:50 +08003071 error = sctp_eat_data(asoc, chunk, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003072 switch (error) {
3073 case SCTP_IERROR_NO_ERROR:
3074 case SCTP_IERROR_HIGH_TSN:
3075 case SCTP_IERROR_DUP_TSN:
3076 case SCTP_IERROR_IGNORE_TSN:
3077 case SCTP_IERROR_BAD_STREAM:
3078 break;
3079 case SCTP_IERROR_NO_DATA:
3080 goto consume;
Vlad Yasevichf1751c52009-09-04 18:21:03 -04003081 case SCTP_IERROR_PROTO_VIOLATION:
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003082 return sctp_sf_abort_violation(net, ep, asoc, chunk, commands,
Vlad Yasevichf1751c52009-09-04 18:21:03 -04003083 (u8 *)chunk->subh.data_hdr, sizeof(sctp_datahdr_t));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003084 default:
3085 BUG();
3086 }
3087
3088 /* Go a head and force a SACK, since we are shutting down. */
3089
3090 /* Implementor's Guide.
3091 *
3092 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3093 * respond to each received packet containing one or more DATA chunk(s)
3094 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3095 */
3096 if (chunk->end_of_packet) {
3097 /* We must delay the chunk creation since the cumulative
3098 * TSN has not been updated yet.
3099 */
3100 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
3101 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3102 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3103 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3104 }
3105
3106consume:
3107 return SCTP_DISPOSITION_CONSUME;
3108}
3109
3110/*
3111 * Section: 6.2 Processing a Received SACK
3112 * D) Any time a SACK arrives, the endpoint performs the following:
3113 *
3114 * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point,
3115 * then drop the SACK. Since Cumulative TSN Ack is monotonically
3116 * increasing, a SACK whose Cumulative TSN Ack is less than the
3117 * Cumulative TSN Ack Point indicates an out-of-order SACK.
3118 *
3119 * ii) Set rwnd equal to the newly received a_rwnd minus the number
3120 * of bytes still outstanding after processing the Cumulative TSN Ack
3121 * and the Gap Ack Blocks.
3122 *
3123 * iii) If the SACK is missing a TSN that was previously
3124 * acknowledged via a Gap Ack Block (e.g., the data receiver
3125 * reneged on the data), then mark the corresponding DATA chunk
3126 * as available for retransmit: Mark it as missing for fast
3127 * retransmit as described in Section 7.2.4 and if no retransmit
3128 * timer is running for the destination address to which the DATA
3129 * chunk was originally transmitted, then T3-rtx is started for
3130 * that destination address.
3131 *
3132 * Verification Tag: 8.5 Verification Tag [Normal verification]
3133 *
3134 * Inputs
3135 * (endpoint, asoc, chunk)
3136 *
3137 * Outputs
3138 * (asoc, reply_msg, msg_up, timers, counters)
3139 *
3140 * The return value is the disposition of the chunk.
3141 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003142sctp_disposition_t sctp_sf_eat_sack_6_2(struct net *net,
3143 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003144 const struct sctp_association *asoc,
3145 const sctp_subtype_t type,
3146 void *arg,
3147 sctp_cmd_seq_t *commands)
3148{
3149 struct sctp_chunk *chunk = arg;
3150 sctp_sackhdr_t *sackh;
3151 __u32 ctsn;
3152
3153 if (!sctp_vtag_verify(chunk, asoc))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003154 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003155
3156 /* Make sure that the SACK chunk has a valid length. */
3157 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_sack_chunk_t)))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003158 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003159 commands);
3160
3161 /* Pull the SACK chunk from the data buffer */
3162 sackh = sctp_sm_pull_sack(chunk);
3163 /* Was this a bogus SACK? */
3164 if (!sackh)
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003165 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003166 chunk->subh.sack_hdr = sackh;
3167 ctsn = ntohl(sackh->cum_tsn_ack);
3168
3169 /* i) If Cumulative TSN Ack is less than the Cumulative TSN
3170 * Ack Point, then drop the SACK. Since Cumulative TSN
3171 * Ack is monotonically increasing, a SACK whose
3172 * Cumulative TSN Ack is less than the Cumulative TSN Ack
3173 * Point indicates an out-of-order SACK.
3174 */
3175 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
Daniel Borkmannbb333812013-06-28 19:49:40 +02003176 pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn,
3177 asoc->ctsn_ack_point);
3178
Linus Torvalds1da177e2005-04-16 15:20:36 -07003179 return SCTP_DISPOSITION_DISCARD;
3180 }
3181
Wei Yongjunaecedea2007-08-02 16:57:44 +08003182 /* If Cumulative TSN Ack beyond the max tsn currently
3183 * send, terminating the association and respond to the
3184 * sender with an ABORT.
3185 */
3186 if (!TSN_lt(ctsn, asoc->next_tsn))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003187 return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands);
Wei Yongjunaecedea2007-08-02 16:57:44 +08003188
Linus Torvalds1da177e2005-04-16 15:20:36 -07003189 /* Return this SACK for further processing. */
Nicolas Dichteledfee032012-10-03 05:43:22 +00003190 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_CHUNK(chunk));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003191
3192 /* Note: We do the rest of the work on the PROCESS_SACK
3193 * sideeffect.
3194 */
3195 return SCTP_DISPOSITION_CONSUME;
3196}
3197
3198/*
3199 * Generate an ABORT in response to a packet.
3200 *
Jerome Forissier047a2422005-04-28 11:58:43 -07003201 * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41
Linus Torvalds1da177e2005-04-16 15:20:36 -07003202 *
Jerome Forissier047a2422005-04-28 11:58:43 -07003203 * 8) The receiver should respond to the sender of the OOTB packet with
3204 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3205 * MUST fill in the Verification Tag field of the outbound packet
3206 * with the value found in the Verification Tag field of the OOTB
3207 * packet and set the T-bit in the Chunk Flags to indicate that the
3208 * Verification Tag is reflected. After sending this ABORT, the
3209 * receiver of the OOTB packet shall discard the OOTB packet and take
3210 * no further action.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003211 *
3212 * Verification Tag:
3213 *
3214 * The return value is the disposition of the chunk.
3215*/
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003216static sctp_disposition_t sctp_sf_tabort_8_4_8(struct net *net,
3217 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003218 const struct sctp_association *asoc,
3219 const sctp_subtype_t type,
3220 void *arg,
3221 sctp_cmd_seq_t *commands)
3222{
3223 struct sctp_packet *packet = NULL;
3224 struct sctp_chunk *chunk = arg;
3225 struct sctp_chunk *abort;
3226
Eric W. Biederman2ce95502012-08-06 08:43:06 +00003227 packet = sctp_ootb_pkt_new(net, asoc, chunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003228
3229 if (packet) {
3230 /* Make an ABORT. The T bit will be set if the asoc
3231 * is NULL.
3232 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003233 abort = sctp_make_abort(asoc, chunk, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003234 if (!abort) {
3235 sctp_ootb_pkt_free(packet);
3236 return SCTP_DISPOSITION_NOMEM;
3237 }
3238
Jerome Forissier047a2422005-04-28 11:58:43 -07003239 /* Reflect vtag if T-Bit is set */
3240 if (sctp_test_T_bit(abort))
3241 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3242
Linus Torvalds1da177e2005-04-16 15:20:36 -07003243 /* Set the skb to the belonging sock for accounting. */
3244 abort->skb->sk = ep->base.sk;
3245
3246 sctp_packet_append_chunk(packet, abort);
3247
3248 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3249 SCTP_PACKET(packet));
3250
Eric W. Biedermanb01a2402012-08-06 08:47:55 +00003251 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003252
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003253 sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003254 return SCTP_DISPOSITION_CONSUME;
3255 }
3256
3257 return SCTP_DISPOSITION_NOMEM;
3258}
3259
3260/*
3261 * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR
3262 * event as ULP notification for each cause included in the chunk.
3263 *
3264 * API 5.3.1.3 - SCTP_REMOTE_ERROR
3265 *
3266 * The return value is the disposition of the chunk.
3267*/
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003268sctp_disposition_t sctp_sf_operr_notify(struct net *net,
3269 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003270 const struct sctp_association *asoc,
3271 const sctp_subtype_t type,
3272 void *arg,
3273 sctp_cmd_seq_t *commands)
3274{
3275 struct sctp_chunk *chunk = arg;
Shan Wei8a00be12011-04-19 21:25:40 +00003276 sctp_errhdr_t *err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003277
3278 if (!sctp_vtag_verify(chunk, asoc))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003279 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003280
3281 /* Make sure that the ERROR chunk has a valid length. */
3282 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003283 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003284 commands);
Shan Wei8a00be12011-04-19 21:25:40 +00003285 sctp_walk_errors(err, chunk->chunk_hdr);
3286 if ((void *)err != (void *)chunk->chunk_end)
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003287 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
Shan Wei8a00be12011-04-19 21:25:40 +00003288 (void *)err, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003289
Wei Yongjun3df26782009-03-02 06:46:51 +00003290 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_OPERR,
3291 SCTP_CHUNK(chunk));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003292
Linus Torvalds1da177e2005-04-16 15:20:36 -07003293 return SCTP_DISPOSITION_CONSUME;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003294}
3295
3296/*
3297 * Process an inbound SHUTDOWN ACK.
3298 *
3299 * From Section 9.2:
3300 * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3301 * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its
3302 * peer, and remove all record of the association.
3303 *
3304 * The return value is the disposition.
3305 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003306sctp_disposition_t sctp_sf_do_9_2_final(struct net *net,
3307 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003308 const struct sctp_association *asoc,
3309 const sctp_subtype_t type,
3310 void *arg,
3311 sctp_cmd_seq_t *commands)
3312{
3313 struct sctp_chunk *chunk = arg;
3314 struct sctp_chunk *reply;
3315 struct sctp_ulpevent *ev;
3316
3317 if (!sctp_vtag_verify(chunk, asoc))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003318 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003319
3320 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3321 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003322 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003323 commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003324 /* 10.2 H) SHUTDOWN COMPLETE notification
3325 *
3326 * When SCTP completes the shutdown procedures (section 9.2) this
3327 * notification is passed to the upper layer.
3328 */
3329 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
Vlad Yasevicha5a35e72007-03-23 11:34:08 -07003330 0, 0, 0, NULL, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003331 if (!ev)
3332 goto nomem;
3333
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07003334 /* ...send a SHUTDOWN COMPLETE chunk to its peer, */
3335 reply = sctp_make_shutdown_complete(asoc, chunk);
3336 if (!reply)
3337 goto nomem_chunk;
3338
3339 /* Do all the commands now (after allocation), so that we
3340 * have consistent state if memory allocation failes
3341 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003342 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
3343
3344 /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3345 * stop the T2-shutdown timer,
3346 */
3347 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3348 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3349
3350 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3351 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
3352
Linus Torvalds1da177e2005-04-16 15:20:36 -07003353 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3354 SCTP_STATE(SCTP_STATE_CLOSED));
Eric W. Biedermanb01a2402012-08-06 08:47:55 +00003355 SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS);
3356 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003357 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
3358
3359 /* ...and remove all record of the association. */
3360 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
3361 return SCTP_DISPOSITION_DELETE_TCB;
3362
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07003363nomem_chunk:
3364 sctp_ulpevent_free(ev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003365nomem:
3366 return SCTP_DISPOSITION_NOMEM;
3367}
3368
3369/*
Jerome Forissier047a2422005-04-28 11:58:43 -07003370 * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41.
3371 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003372 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3373 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3374 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3375 * packet must fill in the Verification Tag field of the outbound
3376 * packet with the Verification Tag received in the SHUTDOWN ACK and
Jerome Forissier047a2422005-04-28 11:58:43 -07003377 * set the T-bit in the Chunk Flags to indicate that the Verification
3378 * Tag is reflected.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003379 *
3380 * 8) The receiver should respond to the sender of the OOTB packet with
3381 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3382 * MUST fill in the Verification Tag field of the outbound packet
3383 * with the value found in the Verification Tag field of the OOTB
Jerome Forissier047a2422005-04-28 11:58:43 -07003384 * packet and set the T-bit in the Chunk Flags to indicate that the
3385 * Verification Tag is reflected. After sending this ABORT, the
3386 * receiver of the OOTB packet shall discard the OOTB packet and take
3387 * no further action.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003388 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003389sctp_disposition_t sctp_sf_ootb(struct net *net,
3390 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003391 const struct sctp_association *asoc,
3392 const sctp_subtype_t type,
3393 void *arg,
3394 sctp_cmd_seq_t *commands)
3395{
3396 struct sctp_chunk *chunk = arg;
3397 struct sk_buff *skb = chunk->skb;
3398 sctp_chunkhdr_t *ch;
Shan Wei85c5ed42011-04-19 21:30:01 +00003399 sctp_errhdr_t *err;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003400 __u8 *ch_end;
3401 int ootb_shut_ack = 0;
Shan Wei85c5ed42011-04-19 21:30:01 +00003402 int ootb_cookie_ack = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003403
Eric W. Biedermanb01a2402012-08-06 08:47:55 +00003404 SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003405
3406 ch = (sctp_chunkhdr_t *) chunk->chunk_hdr;
3407 do {
Vlad Yasevichece25df2007-09-07 16:30:54 -04003408 /* Report violation if the chunk is less then minimal */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003409 if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003410 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
Vlad Yasevichece25df2007-09-07 16:30:54 -04003411 commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003412
Vlad Yasevichece25df2007-09-07 16:30:54 -04003413 /* Now that we know we at least have a chunk header,
3414 * do things that are type appropriate.
3415 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003416 if (SCTP_CID_SHUTDOWN_ACK == ch->type)
3417 ootb_shut_ack = 1;
3418
3419 /* RFC 2960, Section 3.3.7
3420 * Moreover, under any circumstances, an endpoint that
3421 * receives an ABORT MUST NOT respond to that ABORT by
3422 * sending an ABORT of its own.
3423 */
3424 if (SCTP_CID_ABORT == ch->type)
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003425 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003426
Shan Wei85c5ed42011-04-19 21:30:01 +00003427 /* RFC 8.4, 7) If the packet contains a "Stale cookie" ERROR
3428 * or a COOKIE ACK the SCTP Packet should be silently
3429 * discarded.
3430 */
3431
3432 if (SCTP_CID_COOKIE_ACK == ch->type)
3433 ootb_cookie_ack = 1;
3434
3435 if (SCTP_CID_ERROR == ch->type) {
3436 sctp_walk_errors(err, ch) {
3437 if (SCTP_ERROR_STALE_COOKIE == err->cause) {
3438 ootb_cookie_ack = 1;
3439 break;
3440 }
3441 }
3442 }
3443
Vlad Yasevichece25df2007-09-07 16:30:54 -04003444 /* Report violation if chunk len overflows */
3445 ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
3446 if (ch_end > skb_tail_pointer(skb))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003447 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
Vlad Yasevichece25df2007-09-07 16:30:54 -04003448 commands);
3449
Linus Torvalds1da177e2005-04-16 15:20:36 -07003450 ch = (sctp_chunkhdr_t *) ch_end;
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07003451 } while (ch_end < skb_tail_pointer(skb));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003452
3453 if (ootb_shut_ack)
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003454 return sctp_sf_shut_8_4_5(net, ep, asoc, type, arg, commands);
Shan Wei85c5ed42011-04-19 21:30:01 +00003455 else if (ootb_cookie_ack)
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003456 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003457 else
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003458 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003459}
3460
3461/*
3462 * Handle an "Out of the blue" SHUTDOWN ACK.
3463 *
Jerome Forissier047a2422005-04-28 11:58:43 -07003464 * Section: 8.4 5, sctpimpguide 2.41.
3465 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003466 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
Jerome Forissier047a2422005-04-28 11:58:43 -07003467 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3468 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3469 * packet must fill in the Verification Tag field of the outbound
3470 * packet with the Verification Tag received in the SHUTDOWN ACK and
3471 * set the T-bit in the Chunk Flags to indicate that the Verification
3472 * Tag is reflected.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003473 *
3474 * Inputs
3475 * (endpoint, asoc, type, arg, commands)
3476 *
3477 * Outputs
3478 * (sctp_disposition_t)
3479 *
3480 * The return value is the disposition of the chunk.
3481 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003482static sctp_disposition_t sctp_sf_shut_8_4_5(struct net *net,
3483 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003484 const struct sctp_association *asoc,
3485 const sctp_subtype_t type,
3486 void *arg,
3487 sctp_cmd_seq_t *commands)
3488{
3489 struct sctp_packet *packet = NULL;
3490 struct sctp_chunk *chunk = arg;
3491 struct sctp_chunk *shut;
3492
Eric W. Biederman2ce95502012-08-06 08:43:06 +00003493 packet = sctp_ootb_pkt_new(net, asoc, chunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003494
3495 if (packet) {
3496 /* Make an SHUTDOWN_COMPLETE.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003497 * The T bit will be set if the asoc is NULL.
3498 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003499 shut = sctp_make_shutdown_complete(asoc, chunk);
3500 if (!shut) {
3501 sctp_ootb_pkt_free(packet);
3502 return SCTP_DISPOSITION_NOMEM;
3503 }
3504
Jerome Forissier047a2422005-04-28 11:58:43 -07003505 /* Reflect vtag if T-Bit is set */
3506 if (sctp_test_T_bit(shut))
3507 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3508
Linus Torvalds1da177e2005-04-16 15:20:36 -07003509 /* Set the skb to the belonging sock for accounting. */
3510 shut->skb->sk = ep->base.sk;
3511
3512 sctp_packet_append_chunk(packet, shut);
3513
3514 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3515 SCTP_PACKET(packet));
3516
Eric W. Biedermanb01a2402012-08-06 08:47:55 +00003517 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003518
3519 /* If the chunk length is invalid, we don't want to process
3520 * the reset of the packet.
3521 */
3522 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003523 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003524
Vlad Yasevichd3f25962007-09-07 11:47:45 -04003525 /* We need to discard the rest of the packet to prevent
3526 * potential bomming attacks from additional bundled chunks.
3527 * This is documented in SCTP Threats ID.
3528 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003529 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003530 }
3531
3532 return SCTP_DISPOSITION_NOMEM;
3533}
3534
3535/*
3536 * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state.
3537 *
3538 * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK
3539 * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the
3540 * procedures in section 8.4 SHOULD be followed, in other words it
3541 * should be treated as an Out Of The Blue packet.
3542 * [This means that we do NOT check the Verification Tag on these
3543 * chunks. --piggy ]
3544 *
3545 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003546sctp_disposition_t sctp_sf_do_8_5_1_E_sa(struct net *net,
3547 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003548 const struct sctp_association *asoc,
3549 const sctp_subtype_t type,
3550 void *arg,
3551 sctp_cmd_seq_t *commands)
3552{
Vlad Yasevichece25df2007-09-07 16:30:54 -04003553 struct sctp_chunk *chunk = arg;
3554
3555 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3556 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003557 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
Vlad Yasevichece25df2007-09-07 16:30:54 -04003558 commands);
3559
Linus Torvalds1da177e2005-04-16 15:20:36 -07003560 /* Although we do have an association in this case, it corresponds
3561 * to a restarted association. So the packet is treated as an OOTB
3562 * packet and the state function that handles OOTB SHUTDOWN_ACK is
3563 * called with a NULL association.
3564 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003565 SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
Wei Yongjun8190f892008-09-08 12:13:55 +08003566
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003567 return sctp_sf_shut_8_4_5(net, ep, NULL, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003568}
3569
3570/* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003571sctp_disposition_t sctp_sf_do_asconf(struct net *net,
3572 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003573 const struct sctp_association *asoc,
3574 const sctp_subtype_t type, void *arg,
3575 sctp_cmd_seq_t *commands)
3576{
3577 struct sctp_chunk *chunk = arg;
3578 struct sctp_chunk *asconf_ack = NULL;
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003579 struct sctp_paramhdr *err_param = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003580 sctp_addiphdr_t *hdr;
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003581 union sctp_addr_param *addr_param;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003582 __u32 serial;
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003583 int length;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003584
3585 if (!sctp_vtag_verify(chunk, asoc)) {
3586 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3587 SCTP_NULL());
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003588 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003589 }
3590
Vlad Yasevich6afd2e82007-12-20 14:08:04 -08003591 /* ADD-IP: Section 4.1.1
3592 * This chunk MUST be sent in an authenticated way by using
3593 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3594 * is received unauthenticated it MUST be silently discarded as
3595 * described in [I-D.ietf-tsvwg-sctp-auth].
3596 */
Eric W. Biedermane1fc3b12012-08-07 07:29:57 +00003597 if (!net->sctp.addip_noauth && !chunk->auth)
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003598 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
Vlad Yasevich6afd2e82007-12-20 14:08:04 -08003599
Linus Torvalds1da177e2005-04-16 15:20:36 -07003600 /* Make sure that the ASCONF ADDIP chunk has a valid length. */
3601 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_addip_chunk_t)))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003602 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003603 commands);
3604
3605 hdr = (sctp_addiphdr_t *)chunk->skb->data;
3606 serial = ntohl(hdr->serial);
3607
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003608 addr_param = (union sctp_addr_param *)hdr->params;
3609 length = ntohs(addr_param->p.length);
3610 if (length < sizeof(sctp_paramhdr_t))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003611 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003612 (void *)addr_param, commands);
3613
3614 /* Verify the ASCONF chunk before processing it. */
3615 if (!sctp_verify_asconf(asoc,
Vlad Yasevicha08de642007-12-20 14:11:47 -08003616 (sctp_paramhdr_t *)((void *)addr_param + length),
3617 (void *)chunk->chunk_end,
3618 &err_param))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003619 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
Wei Yongjunba016672008-09-30 05:32:24 -07003620 (void *)err_param, commands);
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003621
Vlad Yasevicha08de642007-12-20 14:11:47 -08003622 /* ADDIP 5.2 E1) Compare the value of the serial number to the value
Linus Torvalds1da177e2005-04-16 15:20:36 -07003623 * the endpoint stored in a new association variable
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003624 * 'Peer-Serial-Number'.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003625 */
3626 if (serial == asoc->peer.addip_serial + 1) {
Vlad Yasevicha08de642007-12-20 14:11:47 -08003627 /* If this is the first instance of ASCONF in the packet,
3628 * we can clean our old ASCONF-ACKs.
3629 */
3630 if (!chunk->has_asconf)
3631 sctp_assoc_clean_asconf_ack_cache(asoc);
3632
3633 /* ADDIP 5.2 E4) When the Sequence Number matches the next one
3634 * expected, process the ASCONF as described below and after
3635 * processing the ASCONF Chunk, append an ASCONF-ACK Chunk to
3636 * the response packet and cache a copy of it (in the event it
3637 * later needs to be retransmitted).
3638 *
3639 * Essentially, do V1-V5.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003640 */
3641 asconf_ack = sctp_process_asconf((struct sctp_association *)
3642 asoc, chunk);
3643 if (!asconf_ack)
3644 return SCTP_DISPOSITION_NOMEM;
Vlad Yasevicha08de642007-12-20 14:11:47 -08003645 } else if (serial < asoc->peer.addip_serial + 1) {
3646 /* ADDIP 5.2 E2)
3647 * If the value found in the Sequence Number is less than the
3648 * ('Peer- Sequence-Number' + 1), simply skip to the next
3649 * ASCONF, and include in the outbound response packet
3650 * any previously cached ASCONF-ACK response that was
3651 * sent and saved that matches the Sequence Number of the
3652 * ASCONF. Note: It is possible that no cached ASCONF-ACK
3653 * Chunk exists. This will occur when an older ASCONF
3654 * arrives out of order. In such a case, the receiver
3655 * should skip the ASCONF Chunk and not include ASCONF-ACK
3656 * Chunk for that chunk.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003657 */
Vlad Yasevicha08de642007-12-20 14:11:47 -08003658 asconf_ack = sctp_assoc_lookup_asconf_ack(asoc, hdr->serial);
3659 if (!asconf_ack)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003660 return SCTP_DISPOSITION_DISCARD;
Vlad Yasevich31b02e12009-09-04 18:21:00 -04003661
3662 /* Reset the transport so that we select the correct one
3663 * this time around. This is to make sure that we don't
3664 * accidentally use a stale transport that's been removed.
3665 */
3666 asconf_ack->transport = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003667 } else {
Vlad Yasevicha08de642007-12-20 14:11:47 -08003668 /* ADDIP 5.2 E5) Otherwise, the ASCONF Chunk is discarded since
Linus Torvalds1da177e2005-04-16 15:20:36 -07003669 * it must be either a stale packet or from an attacker.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003670 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003671 return SCTP_DISPOSITION_DISCARD;
3672 }
3673
Vlad Yasevicha08de642007-12-20 14:11:47 -08003674 /* ADDIP 5.2 E6) The destination address of the SCTP packet
3675 * containing the ASCONF-ACK Chunks MUST be the source address of
3676 * the SCTP packet that held the ASCONF Chunks.
3677 *
3678 * To do this properly, we'll set the destination address of the chunk
3679 * and at the transmit time, will try look up the transport to use.
3680 * Since ASCONFs may be bundled, the correct transport may not be
Thadeu Lima de Souza Cascardo94e2bd62009-10-16 15:20:49 +02003681 * created until we process the entire packet, thus this workaround.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003682 */
Vlad Yasevicha08de642007-12-20 14:11:47 -08003683 asconf_ack->dest = chunk->source;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003684 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(asconf_ack));
Michio Honda6af29cc2011-06-16 17:14:34 +09003685 if (asoc->new_transport) {
wangweidongf7010e62013-12-23 12:16:52 +08003686 sctp_sf_heartbeat(ep, asoc, type, asoc->new_transport, commands);
Michio Honda6af29cc2011-06-16 17:14:34 +09003687 ((struct sctp_association *)asoc)->new_transport = NULL;
3688 }
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003689
Linus Torvalds1da177e2005-04-16 15:20:36 -07003690 return SCTP_DISPOSITION_CONSUME;
3691}
3692
3693/*
3694 * ADDIP Section 4.3 General rules for address manipulation
3695 * When building TLV parameters for the ASCONF Chunk that will add or
3696 * delete IP addresses the D0 to D13 rules should be applied:
3697 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003698sctp_disposition_t sctp_sf_do_asconf_ack(struct net *net,
3699 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003700 const struct sctp_association *asoc,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003701 const sctp_subtype_t type, void *arg,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003702 sctp_cmd_seq_t *commands)
3703{
3704 struct sctp_chunk *asconf_ack = arg;
3705 struct sctp_chunk *last_asconf = asoc->addip_last_asconf;
3706 struct sctp_chunk *abort;
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003707 struct sctp_paramhdr *err_param = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003708 sctp_addiphdr_t *addip_hdr;
3709 __u32 sent_serial, rcvd_serial;
3710
3711 if (!sctp_vtag_verify(asconf_ack, asoc)) {
3712 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3713 SCTP_NULL());
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003714 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003715 }
3716
Vlad Yasevich6afd2e82007-12-20 14:08:04 -08003717 /* ADD-IP, Section 4.1.2:
3718 * This chunk MUST be sent in an authenticated way by using
3719 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3720 * is received unauthenticated it MUST be silently discarded as
3721 * described in [I-D.ietf-tsvwg-sctp-auth].
3722 */
Eric W. Biedermane1fc3b12012-08-07 07:29:57 +00003723 if (!net->sctp.addip_noauth && !asconf_ack->auth)
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003724 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
Vlad Yasevich6afd2e82007-12-20 14:08:04 -08003725
Linus Torvalds1da177e2005-04-16 15:20:36 -07003726 /* Make sure that the ADDIP chunk has a valid length. */
3727 if (!sctp_chunk_length_valid(asconf_ack, sizeof(sctp_addip_chunk_t)))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003728 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003729 commands);
3730
3731 addip_hdr = (sctp_addiphdr_t *)asconf_ack->skb->data;
3732 rcvd_serial = ntohl(addip_hdr->serial);
3733
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003734 /* Verify the ASCONF-ACK chunk before processing it. */
3735 if (!sctp_verify_asconf(asoc,
3736 (sctp_paramhdr_t *)addip_hdr->params,
3737 (void *)asconf_ack->chunk_end,
3738 &err_param))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003739 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
Wei Yongjunba016672008-09-30 05:32:24 -07003740 (void *)err_param, commands);
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003741
Linus Torvalds1da177e2005-04-16 15:20:36 -07003742 if (last_asconf) {
3743 addip_hdr = (sctp_addiphdr_t *)last_asconf->subh.addip_hdr;
3744 sent_serial = ntohl(addip_hdr->serial);
3745 } else {
3746 sent_serial = asoc->addip_serial - 1;
3747 }
3748
3749 /* D0) If an endpoint receives an ASCONF-ACK that is greater than or
3750 * equal to the next serial number to be used but no ASCONF chunk is
3751 * outstanding the endpoint MUST ABORT the association. Note that a
3752 * sequence number is greater than if it is no more than 2^^31-1
3753 * larger than the current sequence number (using serial arithmetic).
3754 */
3755 if (ADDIP_SERIAL_gte(rcvd_serial, sent_serial + 1) &&
3756 !(asoc->addip_last_asconf)) {
3757 abort = sctp_make_abort(asoc, asconf_ack,
3758 sizeof(sctp_errhdr_t));
3759 if (abort) {
Wei Yongjun00f1c2d2007-08-21 15:50:01 +08003760 sctp_init_cause(abort, SCTP_ERROR_ASCONF_ACK, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003761 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3762 SCTP_CHUNK(abort));
3763 }
3764 /* We are going to ABORT, so we might as well stop
3765 * processing the rest of the chunks in the packet.
3766 */
3767 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3768 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
wangweidongcb3f8372013-12-23 12:16:50 +08003769 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07003770 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003771 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003772 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08003773 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
Eric W. Biedermanb01a2402012-08-06 08:47:55 +00003774 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
3775 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003776 return SCTP_DISPOSITION_ABORT;
3777 }
3778
3779 if ((rcvd_serial == sent_serial) && asoc->addip_last_asconf) {
3780 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3781 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3782
3783 if (!sctp_process_asconf_ack((struct sctp_association *)asoc,
Vlad Yasevichc0786692010-04-28 08:47:22 +00003784 asconf_ack)) {
3785 /* Successfully processed ASCONF_ACK. We can
3786 * release the next asconf if we have one.
3787 */
3788 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_NEXT_ASCONF,
3789 SCTP_NULL());
Linus Torvalds1da177e2005-04-16 15:20:36 -07003790 return SCTP_DISPOSITION_CONSUME;
Vlad Yasevichc0786692010-04-28 08:47:22 +00003791 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07003792
3793 abort = sctp_make_abort(asoc, asconf_ack,
3794 sizeof(sctp_errhdr_t));
3795 if (abort) {
Wei Yongjun00f1c2d2007-08-21 15:50:01 +08003796 sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003797 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3798 SCTP_CHUNK(abort));
3799 }
3800 /* We are going to ABORT, so we might as well stop
3801 * processing the rest of the chunks in the packet.
3802 */
wangweidongcb3f8372013-12-23 12:16:50 +08003803 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07003804 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003805 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003806 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08003807 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
Eric W. Biedermanb01a2402012-08-06 08:47:55 +00003808 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
3809 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003810 return SCTP_DISPOSITION_ABORT;
3811 }
3812
3813 return SCTP_DISPOSITION_DISCARD;
3814}
3815
3816/*
3817 * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP
3818 *
3819 * When a FORWARD TSN chunk arrives, the data receiver MUST first update
3820 * its cumulative TSN point to the value carried in the FORWARD TSN
3821 * chunk, and then MUST further advance its cumulative TSN point locally
3822 * if possible.
3823 * After the above processing, the data receiver MUST stop reporting any
3824 * missing TSNs earlier than or equal to the new cumulative TSN point.
3825 *
3826 * Verification Tag: 8.5 Verification Tag [Normal verification]
3827 *
3828 * The return value is the disposition of the chunk.
3829 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003830sctp_disposition_t sctp_sf_eat_fwd_tsn(struct net *net,
3831 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003832 const struct sctp_association *asoc,
3833 const sctp_subtype_t type,
3834 void *arg,
3835 sctp_cmd_seq_t *commands)
3836{
3837 struct sctp_chunk *chunk = arg;
3838 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
Wei Yongjun9fcb95a2008-12-25 16:58:11 -08003839 struct sctp_fwdtsn_skip *skip;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003840 __u16 len;
3841 __u32 tsn;
3842
3843 if (!sctp_vtag_verify(chunk, asoc)) {
3844 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3845 SCTP_NULL());
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003846 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003847 }
3848
3849 /* Make sure that the FORWARD_TSN chunk has valid length. */
3850 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003851 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003852 commands);
3853
3854 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3855 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3856 len = ntohs(chunk->chunk_hdr->length);
3857 len -= sizeof(struct sctp_chunkhdr);
3858 skb_pull(chunk->skb, len);
3859
3860 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
Daniel Borkmannbb333812013-06-28 19:49:40 +02003861 pr_debug("%s: TSN 0x%x\n", __func__, tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003862
3863 /* The TSN is too high--silently discard the chunk and count on it
3864 * getting retransmitted later.
3865 */
3866 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3867 goto discard_noforce;
3868
Wei Yongjun9fcb95a2008-12-25 16:58:11 -08003869 /* Silently discard the chunk if stream-id is not valid */
3870 sctp_walk_fwdtsn(skip, chunk) {
3871 if (ntohs(skip->stream) >= asoc->c.sinit_max_instreams)
3872 goto discard_noforce;
3873 }
3874
Linus Torvalds1da177e2005-04-16 15:20:36 -07003875 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3876 if (len > sizeof(struct sctp_fwdtsn_hdr))
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003877 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003878 SCTP_CHUNK(chunk));
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003879
Linus Torvalds1da177e2005-04-16 15:20:36 -07003880 /* Count this as receiving DATA. */
Neil Horman9f70f462013-12-10 06:48:15 -05003881 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07003882 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3883 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
3884 }
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003885
Linus Torvalds1da177e2005-04-16 15:20:36 -07003886 /* FIXME: For now send a SACK, but DATA processing may
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003887 * send another.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003888 */
3889 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
Linus Torvalds1da177e2005-04-16 15:20:36 -07003890
3891 return SCTP_DISPOSITION_CONSUME;
3892
3893discard_noforce:
3894 return SCTP_DISPOSITION_DISCARD;
3895}
3896
3897sctp_disposition_t sctp_sf_eat_fwd_tsn_fast(
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003898 struct net *net,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003899 const struct sctp_endpoint *ep,
3900 const struct sctp_association *asoc,
3901 const sctp_subtype_t type,
3902 void *arg,
3903 sctp_cmd_seq_t *commands)
3904{
3905 struct sctp_chunk *chunk = arg;
3906 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
Wei Yongjun9fcb95a2008-12-25 16:58:11 -08003907 struct sctp_fwdtsn_skip *skip;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003908 __u16 len;
3909 __u32 tsn;
3910
3911 if (!sctp_vtag_verify(chunk, asoc)) {
3912 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3913 SCTP_NULL());
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003914 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003915 }
3916
3917 /* Make sure that the FORWARD_TSN chunk has a valid length. */
3918 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003919 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003920 commands);
3921
3922 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3923 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3924 len = ntohs(chunk->chunk_hdr->length);
3925 len -= sizeof(struct sctp_chunkhdr);
3926 skb_pull(chunk->skb, len);
3927
3928 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
Daniel Borkmannbb333812013-06-28 19:49:40 +02003929 pr_debug("%s: TSN 0x%x\n", __func__, tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003930
3931 /* The TSN is too high--silently discard the chunk and count on it
3932 * getting retransmitted later.
3933 */
3934 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3935 goto gen_shutdown;
3936
Wei Yongjun9fcb95a2008-12-25 16:58:11 -08003937 /* Silently discard the chunk if stream-id is not valid */
3938 sctp_walk_fwdtsn(skip, chunk) {
3939 if (ntohs(skip->stream) >= asoc->c.sinit_max_instreams)
3940 goto gen_shutdown;
3941 }
3942
Linus Torvalds1da177e2005-04-16 15:20:36 -07003943 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3944 if (len > sizeof(struct sctp_fwdtsn_hdr))
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003945 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003946 SCTP_CHUNK(chunk));
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003947
Linus Torvalds1da177e2005-04-16 15:20:36 -07003948 /* Go a head and force a SACK, since we are shutting down. */
3949gen_shutdown:
3950 /* Implementor's Guide.
3951 *
3952 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3953 * respond to each received packet containing one or more DATA chunk(s)
3954 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3955 */
3956 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
3957 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3958 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3959 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3960
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003961 return SCTP_DISPOSITION_CONSUME;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003962}
3963
3964/*
Lucas De Marchi25985ed2011-03-30 22:57:33 -03003965 * SCTP-AUTH Section 6.3 Receiving authenticated chukns
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07003966 *
3967 * The receiver MUST use the HMAC algorithm indicated in the HMAC
3968 * Identifier field. If this algorithm was not specified by the
3969 * receiver in the HMAC-ALGO parameter in the INIT or INIT-ACK chunk
3970 * during association setup, the AUTH chunk and all chunks after it MUST
3971 * be discarded and an ERROR chunk SHOULD be sent with the error cause
3972 * defined in Section 4.1.
3973 *
3974 * If an endpoint with no shared key receives a Shared Key Identifier
3975 * other than 0, it MUST silently discard all authenticated chunks. If
3976 * the endpoint has at least one endpoint pair shared key for the peer,
3977 * it MUST use the key specified by the Shared Key Identifier if a
3978 * key has been configured for that Shared Key Identifier. If no
3979 * endpoint pair shared key has been configured for that Shared Key
3980 * Identifier, all authenticated chunks MUST be silently discarded.
3981 *
3982 * Verification Tag: 8.5 Verification Tag [Normal verification]
3983 *
3984 * The return value is the disposition of the chunk.
3985 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00003986static sctp_ierror_t sctp_sf_authenticate(struct net *net,
3987 const struct sctp_endpoint *ep,
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07003988 const struct sctp_association *asoc,
3989 const sctp_subtype_t type,
3990 struct sctp_chunk *chunk)
3991{
3992 struct sctp_authhdr *auth_hdr;
3993 struct sctp_hmac *hmac;
3994 unsigned int sig_len;
3995 __u16 key_id;
3996 __u8 *save_digest;
3997 __u8 *digest;
3998
3999 /* Pull in the auth header, so we can do some more verification */
4000 auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
4001 chunk->subh.auth_hdr = auth_hdr;
4002 skb_pull(chunk->skb, sizeof(struct sctp_authhdr));
4003
Masanari Iida02582e92012-08-22 19:11:26 +09004004 /* Make sure that we support the HMAC algorithm from the auth
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07004005 * chunk.
4006 */
4007 if (!sctp_auth_asoc_verify_hmac_id(asoc, auth_hdr->hmac_id))
4008 return SCTP_IERROR_AUTH_BAD_HMAC;
4009
4010 /* Make sure that the provided shared key identifier has been
4011 * configured
4012 */
4013 key_id = ntohs(auth_hdr->shkey_id);
4014 if (key_id != asoc->active_key_id && !sctp_auth_get_shkey(asoc, key_id))
4015 return SCTP_IERROR_AUTH_BAD_KEYID;
4016
4017
4018 /* Make sure that the length of the signature matches what
4019 * we expect.
4020 */
4021 sig_len = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_auth_chunk_t);
4022 hmac = sctp_auth_get_hmac(ntohs(auth_hdr->hmac_id));
4023 if (sig_len != hmac->hmac_len)
4024 return SCTP_IERROR_PROTO_VIOLATION;
4025
4026 /* Now that we've done validation checks, we can compute and
4027 * verify the hmac. The steps involved are:
4028 * 1. Save the digest from the chunk.
4029 * 2. Zero out the digest in the chunk.
4030 * 3. Compute the new digest
4031 * 4. Compare saved and new digests.
4032 */
4033 digest = auth_hdr->hmac;
4034 skb_pull(chunk->skb, sig_len);
4035
4036 save_digest = kmemdup(digest, sig_len, GFP_ATOMIC);
4037 if (!save_digest)
4038 goto nomem;
4039
4040 memset(digest, 0, sig_len);
4041
4042 sctp_auth_calculate_hmac(asoc, chunk->skb,
4043 (struct sctp_auth_chunk *)chunk->chunk_hdr,
4044 GFP_ATOMIC);
4045
4046 /* Discard the packet if the digests do not match */
4047 if (memcmp(save_digest, digest, sig_len)) {
4048 kfree(save_digest);
4049 return SCTP_IERROR_BAD_SIG;
4050 }
4051
4052 kfree(save_digest);
4053 chunk->auth = 1;
4054
4055 return SCTP_IERROR_NO_ERROR;
4056nomem:
4057 return SCTP_IERROR_NOMEM;
4058}
4059
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004060sctp_disposition_t sctp_sf_eat_auth(struct net *net,
4061 const struct sctp_endpoint *ep,
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07004062 const struct sctp_association *asoc,
4063 const sctp_subtype_t type,
4064 void *arg,
4065 sctp_cmd_seq_t *commands)
4066{
4067 struct sctp_authhdr *auth_hdr;
4068 struct sctp_chunk *chunk = arg;
4069 struct sctp_chunk *err_chunk;
4070 sctp_ierror_t error;
4071
Wei Yongjund2f19fa2008-02-05 03:02:26 -08004072 /* Make sure that the peer has AUTH capable */
4073 if (!asoc->peer.auth_capable)
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004074 return sctp_sf_unk_chunk(net, ep, asoc, type, arg, commands);
Wei Yongjund2f19fa2008-02-05 03:02:26 -08004075
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07004076 if (!sctp_vtag_verify(chunk, asoc)) {
4077 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
4078 SCTP_NULL());
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004079 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07004080 }
4081
4082 /* Make sure that the AUTH chunk has valid length. */
4083 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_auth_chunk)))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004084 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07004085 commands);
4086
4087 auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004088 error = sctp_sf_authenticate(net, ep, asoc, type, chunk);
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07004089 switch (error) {
Joe Perches7fd71b12011-07-01 09:43:11 +00004090 case SCTP_IERROR_AUTH_BAD_HMAC:
4091 /* Generate the ERROR chunk and discard the rest
4092 * of the packet
4093 */
4094 err_chunk = sctp_make_op_error(asoc, chunk,
4095 SCTP_ERROR_UNSUP_HMAC,
4096 &auth_hdr->hmac_id,
4097 sizeof(__u16), 0);
4098 if (err_chunk) {
4099 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4100 SCTP_CHUNK(err_chunk));
4101 }
4102 /* Fall Through */
4103 case SCTP_IERROR_AUTH_BAD_KEYID:
4104 case SCTP_IERROR_BAD_SIG:
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004105 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Joe Perches7fd71b12011-07-01 09:43:11 +00004106
4107 case SCTP_IERROR_PROTO_VIOLATION:
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004108 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
Joe Perches7fd71b12011-07-01 09:43:11 +00004109 commands);
4110
4111 case SCTP_IERROR_NOMEM:
4112 return SCTP_DISPOSITION_NOMEM;
4113
4114 default: /* Prevent gcc warnings */
4115 break;
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07004116 }
4117
Vlad Yasevich65b07e52007-09-16 19:34:00 -07004118 if (asoc->active_key_id != ntohs(auth_hdr->shkey_id)) {
4119 struct sctp_ulpevent *ev;
4120
4121 ev = sctp_ulpevent_make_authkey(asoc, ntohs(auth_hdr->shkey_id),
4122 SCTP_AUTH_NEWKEY, GFP_ATOMIC);
4123
4124 if (!ev)
4125 return -ENOMEM;
4126
4127 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
4128 SCTP_ULPEVENT(ev));
4129 }
4130
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07004131 return SCTP_DISPOSITION_CONSUME;
4132}
4133
4134/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07004135 * Process an unknown chunk.
4136 *
4137 * Section: 3.2. Also, 2.1 in the implementor's guide.
4138 *
4139 * Chunk Types are encoded such that the highest-order two bits specify
4140 * the action that must be taken if the processing endpoint does not
4141 * recognize the Chunk Type.
4142 *
4143 * 00 - Stop processing this SCTP packet and discard it, do not process
4144 * any further chunks within it.
4145 *
4146 * 01 - Stop processing this SCTP packet and discard it, do not process
4147 * any further chunks within it, and report the unrecognized
4148 * chunk in an 'Unrecognized Chunk Type'.
4149 *
4150 * 10 - Skip this chunk and continue processing.
4151 *
4152 * 11 - Skip this chunk and continue processing, but report in an ERROR
4153 * Chunk using the 'Unrecognized Chunk Type' cause of error.
4154 *
4155 * The return value is the disposition of the chunk.
4156 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004157sctp_disposition_t sctp_sf_unk_chunk(struct net *net,
4158 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07004159 const struct sctp_association *asoc,
4160 const sctp_subtype_t type,
4161 void *arg,
4162 sctp_cmd_seq_t *commands)
4163{
4164 struct sctp_chunk *unk_chunk = arg;
4165 struct sctp_chunk *err_chunk;
4166 sctp_chunkhdr_t *hdr;
4167
Daniel Borkmannbb333812013-06-28 19:49:40 +02004168 pr_debug("%s: processing unknown chunk id:%d\n", __func__, type.chunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004169
4170 if (!sctp_vtag_verify(unk_chunk, asoc))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004171 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004172
4173 /* Make sure that the chunk has a valid length.
4174 * Since we don't know the chunk type, we use a general
4175 * chunkhdr structure to make a comparison.
4176 */
4177 if (!sctp_chunk_length_valid(unk_chunk, sizeof(sctp_chunkhdr_t)))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004178 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
Linus Torvalds1da177e2005-04-16 15:20:36 -07004179 commands);
4180
4181 switch (type.chunk & SCTP_CID_ACTION_MASK) {
4182 case SCTP_CID_ACTION_DISCARD:
4183 /* Discard the packet. */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004184 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004185 break;
4186 case SCTP_CID_ACTION_DISCARD_ERR:
Linus Torvalds1da177e2005-04-16 15:20:36 -07004187 /* Generate an ERROR chunk as response. */
4188 hdr = unk_chunk->chunk_hdr;
4189 err_chunk = sctp_make_op_error(asoc, unk_chunk,
4190 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
Vlad Yasevich6383cfb2009-11-23 15:53:56 -05004191 WORD_ROUND(ntohs(hdr->length)),
4192 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004193 if (err_chunk) {
4194 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4195 SCTP_CHUNK(err_chunk));
4196 }
Vlad Yasevich2e3216c2008-06-19 16:08:18 -07004197
4198 /* Discard the packet. */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004199 sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004200 return SCTP_DISPOSITION_CONSUME;
4201 break;
4202 case SCTP_CID_ACTION_SKIP:
4203 /* Skip the chunk. */
4204 return SCTP_DISPOSITION_DISCARD;
4205 break;
4206 case SCTP_CID_ACTION_SKIP_ERR:
4207 /* Generate an ERROR chunk as response. */
4208 hdr = unk_chunk->chunk_hdr;
4209 err_chunk = sctp_make_op_error(asoc, unk_chunk,
4210 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
Vlad Yasevich6383cfb2009-11-23 15:53:56 -05004211 WORD_ROUND(ntohs(hdr->length)),
4212 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004213 if (err_chunk) {
4214 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4215 SCTP_CHUNK(err_chunk));
4216 }
4217 /* Skip the chunk. */
4218 return SCTP_DISPOSITION_CONSUME;
4219 break;
4220 default:
4221 break;
4222 }
4223
4224 return SCTP_DISPOSITION_DISCARD;
4225}
4226
4227/*
4228 * Discard the chunk.
4229 *
4230 * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2
4231 * [Too numerous to mention...]
4232 * Verification Tag: No verification needed.
4233 * Inputs
4234 * (endpoint, asoc, chunk)
4235 *
4236 * Outputs
4237 * (asoc, reply_msg, msg_up, timers, counters)
4238 *
4239 * The return value is the disposition of the chunk.
4240 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004241sctp_disposition_t sctp_sf_discard_chunk(struct net *net,
4242 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07004243 const struct sctp_association *asoc,
4244 const sctp_subtype_t type,
4245 void *arg,
4246 sctp_cmd_seq_t *commands)
4247{
Vlad Yasevichece25df2007-09-07 16:30:54 -04004248 struct sctp_chunk *chunk = arg;
4249
4250 /* Make sure that the chunk has a valid length.
4251 * Since we don't know the chunk type, we use a general
4252 * chunkhdr structure to make a comparison.
4253 */
4254 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004255 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
Vlad Yasevichece25df2007-09-07 16:30:54 -04004256 commands);
4257
Daniel Borkmannbb333812013-06-28 19:49:40 +02004258 pr_debug("%s: chunk:%d is discarded\n", __func__, type.chunk);
4259
Linus Torvalds1da177e2005-04-16 15:20:36 -07004260 return SCTP_DISPOSITION_DISCARD;
4261}
4262
4263/*
4264 * Discard the whole packet.
4265 *
4266 * Section: 8.4 2)
4267 *
4268 * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST
4269 * silently discard the OOTB packet and take no further action.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004270 *
4271 * Verification Tag: No verification necessary
4272 *
4273 * Inputs
4274 * (endpoint, asoc, chunk)
4275 *
4276 * Outputs
4277 * (asoc, reply_msg, msg_up, timers, counters)
4278 *
4279 * The return value is the disposition of the chunk.
4280 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004281sctp_disposition_t sctp_sf_pdiscard(struct net *net,
4282 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07004283 const struct sctp_association *asoc,
4284 const sctp_subtype_t type,
4285 void *arg,
4286 sctp_cmd_seq_t *commands)
4287{
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004288 SCTP_INC_STATS(net, SCTP_MIB_IN_PKT_DISCARDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004289 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
4290
4291 return SCTP_DISPOSITION_CONSUME;
4292}
4293
4294
4295/*
4296 * The other end is violating protocol.
4297 *
4298 * Section: Not specified
4299 * Verification Tag: Not specified
4300 * Inputs
4301 * (endpoint, asoc, chunk)
4302 *
4303 * Outputs
4304 * (asoc, reply_msg, msg_up, timers, counters)
4305 *
4306 * We simply tag the chunk as a violation. The state machine will log
4307 * the violation and continue.
4308 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004309sctp_disposition_t sctp_sf_violation(struct net *net,
4310 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07004311 const struct sctp_association *asoc,
4312 const sctp_subtype_t type,
4313 void *arg,
4314 sctp_cmd_seq_t *commands)
4315{
Vlad Yasevichece25df2007-09-07 16:30:54 -04004316 struct sctp_chunk *chunk = arg;
4317
4318 /* Make sure that the chunk has a valid length. */
4319 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004320 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
Vlad Yasevichece25df2007-09-07 16:30:54 -04004321 commands);
4322
Linus Torvalds1da177e2005-04-16 15:20:36 -07004323 return SCTP_DISPOSITION_VIOLATION;
4324}
4325
Linus Torvalds1da177e2005-04-16 15:20:36 -07004326/*
Wei Yongjunaecedea2007-08-02 16:57:44 +08004327 * Common function to handle a protocol violation.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004328 */
Wei Yongjunaecedea2007-08-02 16:57:44 +08004329static sctp_disposition_t sctp_sf_abort_violation(
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004330 struct net *net,
Vlad Yasevichece25df2007-09-07 16:30:54 -04004331 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07004332 const struct sctp_association *asoc,
Linus Torvalds1da177e2005-04-16 15:20:36 -07004333 void *arg,
Wei Yongjunaecedea2007-08-02 16:57:44 +08004334 sctp_cmd_seq_t *commands,
4335 const __u8 *payload,
4336 const size_t paylen)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004337{
Vlad Yasevichece25df2007-09-07 16:30:54 -04004338 struct sctp_packet *packet = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004339 struct sctp_chunk *chunk = arg;
4340 struct sctp_chunk *abort = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004341
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07004342 /* SCTP-AUTH, Section 6.3:
4343 * It should be noted that if the receiver wants to tear
4344 * down an association in an authenticated way only, the
4345 * handling of malformed packets should not result in
4346 * tearing down the association.
4347 *
4348 * This means that if we only want to abort associations
4349 * in an authenticated way (i.e AUTH+ABORT), then we
Lucas De Marchi25985ed2011-03-30 22:57:33 -03004350 * can't destroy this association just because the packet
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07004351 * was malformed.
4352 */
4353 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
4354 goto discard;
4355
Jesper Juhl9abed242007-11-11 23:57:49 +01004356 /* Make the abort chunk. */
4357 abort = sctp_make_abort_violation(asoc, chunk, payload, paylen);
4358 if (!abort)
4359 goto nomem;
4360
Vlad Yasevichece25df2007-09-07 16:30:54 -04004361 if (asoc) {
Gui Jianfengf4ad85c2008-04-12 18:39:34 -07004362 /* Treat INIT-ACK as a special case during COOKIE-WAIT. */
4363 if (chunk->chunk_hdr->type == SCTP_CID_INIT_ACK &&
4364 !asoc->peer.i.init_tag) {
4365 sctp_initack_chunk_t *initack;
4366
4367 initack = (sctp_initack_chunk_t *)chunk->chunk_hdr;
4368 if (!sctp_chunk_length_valid(chunk,
4369 sizeof(sctp_initack_chunk_t)))
4370 abort->chunk_hdr->flags |= SCTP_CHUNK_FLAG_T;
4371 else {
4372 unsigned int inittag;
4373
4374 inittag = ntohl(initack->init_hdr.init_tag);
4375 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_INITTAG,
4376 SCTP_U32(inittag));
4377 }
4378 }
4379
Vlad Yasevichece25df2007-09-07 16:30:54 -04004380 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
Eric W. Biedermanb01a2402012-08-06 08:47:55 +00004381 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004382
Vlad Yasevichece25df2007-09-07 16:30:54 -04004383 if (asoc->state <= SCTP_STATE_COOKIE_ECHOED) {
4384 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4385 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4386 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4387 SCTP_ERROR(ECONNREFUSED));
4388 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
4389 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4390 } else {
4391 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4392 SCTP_ERROR(ECONNABORTED));
4393 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4394 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
Eric W. Biedermanb01a2402012-08-06 08:47:55 +00004395 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
Vlad Yasevichece25df2007-09-07 16:30:54 -04004396 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07004397 } else {
Eric W. Biederman2ce95502012-08-06 08:43:06 +00004398 packet = sctp_ootb_pkt_new(net, asoc, chunk);
Vlad Yasevichece25df2007-09-07 16:30:54 -04004399
4400 if (!packet)
4401 goto nomem_pkt;
4402
4403 if (sctp_test_T_bit(abort))
4404 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
4405
4406 abort->skb->sk = ep->base.sk;
4407
4408 sctp_packet_append_chunk(packet, abort);
4409
4410 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
4411 SCTP_PACKET(packet));
4412
Eric W. Biedermanb01a2402012-08-06 08:47:55 +00004413 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004414 }
4415
Eric W. Biedermanb01a2402012-08-06 08:47:55 +00004416 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09004417
Vlad Yasevich56eb82b2008-10-09 14:33:01 -07004418discard:
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004419 sctp_sf_pdiscard(net, ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004420 return SCTP_DISPOSITION_ABORT;
4421
Vlad Yasevichece25df2007-09-07 16:30:54 -04004422nomem_pkt:
4423 sctp_chunk_free(abort);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004424nomem:
4425 return SCTP_DISPOSITION_NOMEM;
4426}
4427
Wei Yongjunaecedea2007-08-02 16:57:44 +08004428/*
4429 * Handle a protocol violation when the chunk length is invalid.
Frederik Schwarzer025dfda2008-10-16 19:02:37 +02004430 * "Invalid" length is identified as smaller than the minimal length a
Wei Yongjunaecedea2007-08-02 16:57:44 +08004431 * given chunk can be. For example, a SACK chunk has invalid length
Frederik Schwarzer025dfda2008-10-16 19:02:37 +02004432 * if its length is set to be smaller than the size of sctp_sack_chunk_t.
Wei Yongjunaecedea2007-08-02 16:57:44 +08004433 *
4434 * We inform the other end by sending an ABORT with a Protocol Violation
4435 * error code.
4436 *
4437 * Section: Not specified
4438 * Verification Tag: Nothing to do
4439 * Inputs
4440 * (endpoint, asoc, chunk)
4441 *
4442 * Outputs
4443 * (reply_msg, msg_up, counters)
4444 *
4445 * Generate an ABORT chunk and terminate the association.
4446 */
4447static sctp_disposition_t sctp_sf_violation_chunklen(
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004448 struct net *net,
Wei Yongjunaecedea2007-08-02 16:57:44 +08004449 const struct sctp_endpoint *ep,
4450 const struct sctp_association *asoc,
4451 const sctp_subtype_t type,
4452 void *arg,
4453 sctp_cmd_seq_t *commands)
4454{
wangweidongcb3f8372013-12-23 12:16:50 +08004455 static const char err_str[] = "The following chunk had invalid length:";
Wei Yongjunaecedea2007-08-02 16:57:44 +08004456
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004457 return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str,
Wei Yongjunaecedea2007-08-02 16:57:44 +08004458 sizeof(err_str));
4459}
4460
Wei Yongjun6f4c6182007-09-19 17:19:52 +08004461/*
4462 * Handle a protocol violation when the parameter length is invalid.
Shan Wei33c7cfd2011-04-18 19:11:01 +00004463 * If the length is smaller than the minimum length of a given parameter,
4464 * or accumulated length in multi parameters exceeds the end of the chunk,
4465 * the length is considered as invalid.
Wei Yongjun6f4c6182007-09-19 17:19:52 +08004466 */
4467static sctp_disposition_t sctp_sf_violation_paramlen(
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004468 struct net *net,
Wei Yongjun6f4c6182007-09-19 17:19:52 +08004469 const struct sctp_endpoint *ep,
4470 const struct sctp_association *asoc,
4471 const sctp_subtype_t type,
Wei Yongjunba016672008-09-30 05:32:24 -07004472 void *arg, void *ext,
4473 sctp_cmd_seq_t *commands)
4474{
4475 struct sctp_chunk *chunk = arg;
4476 struct sctp_paramhdr *param = ext;
4477 struct sctp_chunk *abort = NULL;
Wei Yongjun6f4c6182007-09-19 17:19:52 +08004478
Wei Yongjunba016672008-09-30 05:32:24 -07004479 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
4480 goto discard;
4481
4482 /* Make the abort chunk. */
4483 abort = sctp_make_violation_paramlen(asoc, chunk, param);
4484 if (!abort)
4485 goto nomem;
4486
4487 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
Eric W. Biedermanb01a2402012-08-06 08:47:55 +00004488 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
Wei Yongjunba016672008-09-30 05:32:24 -07004489
4490 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4491 SCTP_ERROR(ECONNABORTED));
4492 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4493 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
Eric W. Biedermanb01a2402012-08-06 08:47:55 +00004494 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
4495 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
Wei Yongjunba016672008-09-30 05:32:24 -07004496
4497discard:
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004498 sctp_sf_pdiscard(net, ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
Wei Yongjunba016672008-09-30 05:32:24 -07004499 return SCTP_DISPOSITION_ABORT;
4500nomem:
4501 return SCTP_DISPOSITION_NOMEM;
Wei Yongjun6f4c6182007-09-19 17:19:52 +08004502}
4503
Wei Yongjunaecedea2007-08-02 16:57:44 +08004504/* Handle a protocol violation when the peer trying to advance the
4505 * cumulative tsn ack to a point beyond the max tsn currently sent.
4506 *
4507 * We inform the other end by sending an ABORT with a Protocol Violation
4508 * error code.
4509 */
4510static sctp_disposition_t sctp_sf_violation_ctsn(
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004511 struct net *net,
Wei Yongjunaecedea2007-08-02 16:57:44 +08004512 const struct sctp_endpoint *ep,
4513 const struct sctp_association *asoc,
4514 const sctp_subtype_t type,
4515 void *arg,
4516 sctp_cmd_seq_t *commands)
4517{
wangweidongcb3f8372013-12-23 12:16:50 +08004518 static const char err_str[] = "The cumulative tsn ack beyond the max tsn currently sent:";
Wei Yongjunaecedea2007-08-02 16:57:44 +08004519
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004520 return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str,
Wei Yongjunaecedea2007-08-02 16:57:44 +08004521 sizeof(err_str));
4522}
4523
Vlad Yasevichece25df2007-09-07 16:30:54 -04004524/* Handle protocol violation of an invalid chunk bundling. For example,
Lucas De Marchi25985ed2011-03-30 22:57:33 -03004525 * when we have an association and we receive bundled INIT-ACK, or
Vlad Yasevichece25df2007-09-07 16:30:54 -04004526 * SHUDOWN-COMPLETE, our peer is clearly violationg the "MUST NOT bundle"
Lucas De Marchi25985ed2011-03-30 22:57:33 -03004527 * statement from the specs. Additionally, there might be an attacker
Vlad Yasevichece25df2007-09-07 16:30:54 -04004528 * on the path and we may not want to continue this communication.
4529 */
4530static sctp_disposition_t sctp_sf_violation_chunk(
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004531 struct net *net,
Vlad Yasevichece25df2007-09-07 16:30:54 -04004532 const struct sctp_endpoint *ep,
4533 const struct sctp_association *asoc,
4534 const sctp_subtype_t type,
4535 void *arg,
4536 sctp_cmd_seq_t *commands)
4537{
wangweidongcb3f8372013-12-23 12:16:50 +08004538 static const char err_str[] = "The following chunk violates protocol:";
Vlad Yasevichece25df2007-09-07 16:30:54 -04004539
4540 if (!asoc)
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004541 return sctp_sf_violation(net, ep, asoc, type, arg, commands);
Vlad Yasevichece25df2007-09-07 16:30:54 -04004542
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004543 return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str,
Vlad Yasevichece25df2007-09-07 16:30:54 -04004544 sizeof(err_str));
4545}
Linus Torvalds1da177e2005-04-16 15:20:36 -07004546/***************************************************************************
4547 * These are the state functions for handling primitive (Section 10) events.
4548 ***************************************************************************/
4549/*
4550 * sctp_sf_do_prm_asoc
4551 *
4552 * Section: 10.1 ULP-to-SCTP
4553 * B) Associate
4554 *
4555 * Format: ASSOCIATE(local SCTP instance name, destination transport addr,
4556 * outbound stream count)
4557 * -> association id [,destination transport addr list] [,outbound stream
4558 * count]
4559 *
4560 * This primitive allows the upper layer to initiate an association to a
4561 * specific peer endpoint.
4562 *
4563 * The peer endpoint shall be specified by one of the transport addresses
4564 * which defines the endpoint (see Section 1.4). If the local SCTP
4565 * instance has not been initialized, the ASSOCIATE is considered an
4566 * error.
4567 * [This is not relevant for the kernel implementation since we do all
4568 * initialization at boot time. It we hadn't initialized we wouldn't
4569 * get anywhere near this code.]
4570 *
4571 * An association id, which is a local handle to the SCTP association,
4572 * will be returned on successful establishment of the association. If
4573 * SCTP is not able to open an SCTP association with the peer endpoint,
4574 * an error is returned.
4575 * [In the kernel implementation, the struct sctp_association needs to
4576 * be created BEFORE causing this primitive to run.]
4577 *
4578 * Other association parameters may be returned, including the
4579 * complete destination transport addresses of the peer as well as the
4580 * outbound stream count of the local endpoint. One of the transport
4581 * address from the returned destination addresses will be selected by
4582 * the local endpoint as default primary path for sending SCTP packets
4583 * to this peer. The returned "destination transport addr list" can
4584 * be used by the ULP to change the default primary path or to force
4585 * sending a packet to a specific transport address. [All of this
4586 * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING
4587 * function.]
4588 *
4589 * Mandatory attributes:
4590 *
4591 * o local SCTP instance name - obtained from the INITIALIZE operation.
4592 * [This is the argument asoc.]
4593 * o destination transport addr - specified as one of the transport
4594 * addresses of the peer endpoint with which the association is to be
4595 * established.
4596 * [This is asoc->peer.active_path.]
4597 * o outbound stream count - the number of outbound streams the ULP
4598 * would like to open towards this peer endpoint.
4599 * [BUG: This is not currently implemented.]
4600 * Optional attributes:
4601 *
4602 * None.
4603 *
4604 * The return value is a disposition.
4605 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004606sctp_disposition_t sctp_sf_do_prm_asoc(struct net *net,
4607 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07004608 const struct sctp_association *asoc,
4609 const sctp_subtype_t type,
4610 void *arg,
4611 sctp_cmd_seq_t *commands)
4612{
4613 struct sctp_chunk *repl;
wangweidong26ac8e52013-12-23 12:16:51 +08004614 struct sctp_association *my_asoc;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004615
4616 /* The comment below says that we enter COOKIE-WAIT AFTER
4617 * sending the INIT, but that doesn't actually work in our
4618 * implementation...
4619 */
4620 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4621 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
4622
4623 /* RFC 2960 5.1 Normal Establishment of an Association
4624 *
4625 * A) "A" first sends an INIT chunk to "Z". In the INIT, "A"
4626 * must provide its Verification Tag (Tag_A) in the Initiate
4627 * Tag field. Tag_A SHOULD be a random number in the range of
4628 * 1 to 4294967295 (see 5.3.1 for Tag value selection). ...
4629 */
4630
4631 repl = sctp_make_init(asoc, &asoc->base.bind_addr, GFP_ATOMIC, 0);
4632 if (!repl)
4633 goto nomem;
4634
Daniel Borkmann405426f2013-06-14 18:24:05 +02004635 /* Choose transport for INIT. */
4636 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
4637 SCTP_CHUNK(repl));
4638
Linus Torvalds1da177e2005-04-16 15:20:36 -07004639 /* Cast away the const modifier, as we want to just
4640 * rerun it through as a sideffect.
4641 */
Vlad Yasevichab38fb02008-04-12 18:40:06 -07004642 my_asoc = (struct sctp_association *)asoc;
4643 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(my_asoc));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004644
4645 /* After sending the INIT, "A" starts the T1-init timer and
4646 * enters the COOKIE-WAIT state.
4647 */
4648 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4649 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4650 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
4651 return SCTP_DISPOSITION_CONSUME;
4652
4653nomem:
4654 return SCTP_DISPOSITION_NOMEM;
4655}
4656
4657/*
4658 * Process the SEND primitive.
4659 *
4660 * Section: 10.1 ULP-to-SCTP
4661 * E) Send
4662 *
4663 * Format: SEND(association id, buffer address, byte count [,context]
4664 * [,stream id] [,life time] [,destination transport address]
4665 * [,unorder flag] [,no-bundle flag] [,payload protocol-id] )
4666 * -> result
4667 *
4668 * This is the main method to send user data via SCTP.
4669 *
4670 * Mandatory attributes:
4671 *
4672 * o association id - local handle to the SCTP association
4673 *
4674 * o buffer address - the location where the user message to be
4675 * transmitted is stored;
4676 *
4677 * o byte count - The size of the user data in number of bytes;
4678 *
4679 * Optional attributes:
4680 *
4681 * o context - an optional 32 bit integer that will be carried in the
4682 * sending failure notification to the ULP if the transportation of
4683 * this User Message fails.
4684 *
4685 * o stream id - to indicate which stream to send the data on. If not
4686 * specified, stream 0 will be used.
4687 *
4688 * o life time - specifies the life time of the user data. The user data
4689 * will not be sent by SCTP after the life time expires. This
4690 * parameter can be used to avoid efforts to transmit stale
4691 * user messages. SCTP notifies the ULP if the data cannot be
4692 * initiated to transport (i.e. sent to the destination via SCTP's
4693 * send primitive) within the life time variable. However, the
4694 * user data will be transmitted if SCTP has attempted to transmit a
4695 * chunk before the life time expired.
4696 *
4697 * o destination transport address - specified as one of the destination
4698 * transport addresses of the peer endpoint to which this packet
4699 * should be sent. Whenever possible, SCTP should use this destination
4700 * transport address for sending the packets, instead of the current
4701 * primary path.
4702 *
4703 * o unorder flag - this flag, if present, indicates that the user
4704 * would like the data delivered in an unordered fashion to the peer
4705 * (i.e., the U flag is set to 1 on all DATA chunks carrying this
4706 * message).
4707 *
4708 * o no-bundle flag - instructs SCTP not to bundle this user data with
4709 * other outbound DATA chunks. SCTP MAY still bundle even when
4710 * this flag is present, when faced with network congestion.
4711 *
4712 * o payload protocol-id - A 32 bit unsigned integer that is to be
4713 * passed to the peer indicating the type of payload protocol data
4714 * being transmitted. This value is passed as opaque data by SCTP.
4715 *
4716 * The return value is the disposition.
4717 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004718sctp_disposition_t sctp_sf_do_prm_send(struct net *net,
4719 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07004720 const struct sctp_association *asoc,
4721 const sctp_subtype_t type,
4722 void *arg,
4723 sctp_cmd_seq_t *commands)
4724{
Vlad Yasevich9c5c62b2009-08-10 13:51:03 -04004725 struct sctp_datamsg *msg = arg;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004726
Vlad Yasevich9c5c62b2009-08-10 13:51:03 -04004727 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_MSG, SCTP_DATAMSG(msg));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004728 return SCTP_DISPOSITION_CONSUME;
4729}
4730
4731/*
4732 * Process the SHUTDOWN primitive.
4733 *
4734 * Section: 10.1:
4735 * C) Shutdown
4736 *
4737 * Format: SHUTDOWN(association id)
4738 * -> result
4739 *
4740 * Gracefully closes an association. Any locally queued user data
4741 * will be delivered to the peer. The association will be terminated only
4742 * after the peer acknowledges all the SCTP packets sent. A success code
4743 * will be returned on successful termination of the association. If
4744 * attempting to terminate the association results in a failure, an error
4745 * code shall be returned.
4746 *
4747 * Mandatory attributes:
4748 *
4749 * o association id - local handle to the SCTP association
4750 *
4751 * Optional attributes:
4752 *
4753 * None.
4754 *
4755 * The return value is the disposition.
4756 */
4757sctp_disposition_t sctp_sf_do_9_2_prm_shutdown(
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004758 struct net *net,
Linus Torvalds1da177e2005-04-16 15:20:36 -07004759 const struct sctp_endpoint *ep,
4760 const struct sctp_association *asoc,
4761 const sctp_subtype_t type,
4762 void *arg,
4763 sctp_cmd_seq_t *commands)
4764{
4765 int disposition;
4766
4767 /* From 9.2 Shutdown of an Association
4768 * Upon receipt of the SHUTDOWN primitive from its upper
4769 * layer, the endpoint enters SHUTDOWN-PENDING state and
4770 * remains there until all outstanding data has been
4771 * acknowledged by its peer. The endpoint accepts no new data
4772 * from its upper layer, but retransmits data to the far end
4773 * if necessary to fill gaps.
4774 */
4775 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4776 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
4777
Linus Torvalds1da177e2005-04-16 15:20:36 -07004778 disposition = SCTP_DISPOSITION_CONSUME;
4779 if (sctp_outq_is_empty(&asoc->outqueue)) {
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004780 disposition = sctp_sf_do_9_2_start_shutdown(net, ep, asoc, type,
Linus Torvalds1da177e2005-04-16 15:20:36 -07004781 arg, commands);
4782 }
4783 return disposition;
4784}
4785
4786/*
4787 * Process the ABORT primitive.
4788 *
4789 * Section: 10.1:
4790 * C) Abort
4791 *
4792 * Format: Abort(association id [, cause code])
4793 * -> result
4794 *
4795 * Ungracefully closes an association. Any locally queued user data
4796 * will be discarded and an ABORT chunk is sent to the peer. A success code
4797 * will be returned on successful abortion of the association. If
4798 * attempting to abort the association results in a failure, an error
4799 * code shall be returned.
4800 *
4801 * Mandatory attributes:
4802 *
4803 * o association id - local handle to the SCTP association
4804 *
4805 * Optional attributes:
4806 *
4807 * o cause code - reason of the abort to be passed to the peer
4808 *
4809 * None.
4810 *
4811 * The return value is the disposition.
4812 */
4813sctp_disposition_t sctp_sf_do_9_1_prm_abort(
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004814 struct net *net,
Linus Torvalds1da177e2005-04-16 15:20:36 -07004815 const struct sctp_endpoint *ep,
4816 const struct sctp_association *asoc,
4817 const sctp_subtype_t type,
4818 void *arg,
4819 sctp_cmd_seq_t *commands)
4820{
4821 /* From 9.1 Abort of an Association
4822 * Upon receipt of the ABORT primitive from its upper
4823 * layer, the endpoint enters CLOSED state and
4824 * discard all outstanding data has been
4825 * acknowledged by its peer. The endpoint accepts no new data
4826 * from its upper layer, but retransmits data to the far end
4827 * if necessary to fill gaps.
4828 */
Sridhar Samudralac164a9b2006-08-22 11:50:39 -07004829 struct sctp_chunk *abort = arg;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004830 sctp_disposition_t retval;
4831
4832 retval = SCTP_DISPOSITION_CONSUME;
4833
Sridhar Samudralac164a9b2006-08-22 11:50:39 -07004834 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004835
4836 /* Even if we can't send the ABORT due to low memory delete the
4837 * TCB. This is a departure from our typical NOMEM handling.
4838 */
4839
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004840 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4841 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004842 /* Delete the established association. */
4843 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08004844 SCTP_PERR(SCTP_ERROR_USER_ABORT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004845
Eric W. Biedermanb01a2402012-08-06 08:47:55 +00004846 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
4847 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004848
4849 return retval;
4850}
4851
4852/* We tried an illegal operation on an association which is closed. */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004853sctp_disposition_t sctp_sf_error_closed(struct net *net,
4854 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07004855 const struct sctp_association *asoc,
4856 const sctp_subtype_t type,
4857 void *arg,
4858 sctp_cmd_seq_t *commands)
4859{
4860 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, SCTP_ERROR(-EINVAL));
4861 return SCTP_DISPOSITION_CONSUME;
4862}
4863
4864/* We tried an illegal operation on an association which is shutting
4865 * down.
4866 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004867sctp_disposition_t sctp_sf_error_shutdown(struct net *net,
4868 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07004869 const struct sctp_association *asoc,
4870 const sctp_subtype_t type,
4871 void *arg,
4872 sctp_cmd_seq_t *commands)
4873{
4874 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR,
4875 SCTP_ERROR(-ESHUTDOWN));
4876 return SCTP_DISPOSITION_CONSUME;
4877}
4878
4879/*
4880 * sctp_cookie_wait_prm_shutdown
4881 *
4882 * Section: 4 Note: 2
4883 * Verification Tag:
4884 * Inputs
4885 * (endpoint, asoc)
4886 *
4887 * The RFC does not explicitly address this issue, but is the route through the
4888 * state table when someone issues a shutdown while in COOKIE_WAIT state.
4889 *
4890 * Outputs
4891 * (timers)
4892 */
4893sctp_disposition_t sctp_sf_cookie_wait_prm_shutdown(
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004894 struct net *net,
Linus Torvalds1da177e2005-04-16 15:20:36 -07004895 const struct sctp_endpoint *ep,
4896 const struct sctp_association *asoc,
4897 const sctp_subtype_t type,
4898 void *arg,
4899 sctp_cmd_seq_t *commands)
4900{
4901 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4902 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4903
4904 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4905 SCTP_STATE(SCTP_STATE_CLOSED));
4906
Eric W. Biedermanb01a2402012-08-06 08:47:55 +00004907 SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004908
4909 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
4910
4911 return SCTP_DISPOSITION_DELETE_TCB;
4912}
4913
4914/*
4915 * sctp_cookie_echoed_prm_shutdown
4916 *
4917 * Section: 4 Note: 2
4918 * Verification Tag:
4919 * Inputs
4920 * (endpoint, asoc)
4921 *
4922 * The RFC does not explcitly address this issue, but is the route through the
4923 * state table when someone issues a shutdown while in COOKIE_ECHOED state.
4924 *
4925 * Outputs
4926 * (timers)
4927 */
4928sctp_disposition_t sctp_sf_cookie_echoed_prm_shutdown(
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004929 struct net *net,
Linus Torvalds1da177e2005-04-16 15:20:36 -07004930 const struct sctp_endpoint *ep,
4931 const struct sctp_association *asoc,
4932 const sctp_subtype_t type,
4933 void *arg, sctp_cmd_seq_t *commands)
4934{
4935 /* There is a single T1 timer, so we should be able to use
4936 * common function with the COOKIE-WAIT state.
4937 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004938 return sctp_sf_cookie_wait_prm_shutdown(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004939}
4940
4941/*
4942 * sctp_sf_cookie_wait_prm_abort
4943 *
4944 * Section: 4 Note: 2
4945 * Verification Tag:
4946 * Inputs
4947 * (endpoint, asoc)
4948 *
4949 * The RFC does not explicitly address this issue, but is the route through the
4950 * state table when someone issues an abort while in COOKIE_WAIT state.
4951 *
4952 * Outputs
4953 * (timers)
4954 */
4955sctp_disposition_t sctp_sf_cookie_wait_prm_abort(
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00004956 struct net *net,
Linus Torvalds1da177e2005-04-16 15:20:36 -07004957 const struct sctp_endpoint *ep,
4958 const struct sctp_association *asoc,
4959 const sctp_subtype_t type,
4960 void *arg,
4961 sctp_cmd_seq_t *commands)
4962{
Sridhar Samudralac164a9b2006-08-22 11:50:39 -07004963 struct sctp_chunk *abort = arg;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004964 sctp_disposition_t retval;
4965
4966 /* Stop T1-init timer */
4967 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4968 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4969 retval = SCTP_DISPOSITION_CONSUME;
4970
Sridhar Samudralac164a9b2006-08-22 11:50:39 -07004971 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004972
4973 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4974 SCTP_STATE(SCTP_STATE_CLOSED));
4975
Eric W. Biedermanb01a2402012-08-06 08:47:55 +00004976 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004977
4978 /* Even if we can't send the ABORT due to low memory delete the
4979 * TCB. This is a departure from our typical NOMEM handling.
4980 */
4981
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004982 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4983 SCTP_ERROR(ECONNREFUSED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004984 /* Delete the established association. */
4985 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08004986 SCTP_PERR(SCTP_ERROR_USER_ABORT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004987
4988 return retval;
4989}
4990
4991/*
4992 * sctp_sf_cookie_echoed_prm_abort
4993 *
4994 * Section: 4 Note: 3
4995 * Verification Tag:
4996 * Inputs
4997 * (endpoint, asoc)
4998 *
4999 * The RFC does not explcitly address this issue, but is the route through the
5000 * state table when someone issues an abort while in COOKIE_ECHOED state.
5001 *
5002 * Outputs
5003 * (timers)
5004 */
5005sctp_disposition_t sctp_sf_cookie_echoed_prm_abort(
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00005006 struct net *net,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005007 const struct sctp_endpoint *ep,
5008 const struct sctp_association *asoc,
5009 const sctp_subtype_t type,
5010 void *arg,
5011 sctp_cmd_seq_t *commands)
5012{
5013 /* There is a single T1 timer, so we should be able to use
5014 * common function with the COOKIE-WAIT state.
5015 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00005016 return sctp_sf_cookie_wait_prm_abort(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005017}
5018
5019/*
5020 * sctp_sf_shutdown_pending_prm_abort
5021 *
5022 * Inputs
5023 * (endpoint, asoc)
5024 *
5025 * The RFC does not explicitly address this issue, but is the route through the
5026 * state table when someone issues an abort while in SHUTDOWN-PENDING state.
5027 *
5028 * Outputs
5029 * (timers)
5030 */
5031sctp_disposition_t sctp_sf_shutdown_pending_prm_abort(
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00005032 struct net *net,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005033 const struct sctp_endpoint *ep,
5034 const struct sctp_association *asoc,
5035 const sctp_subtype_t type,
5036 void *arg,
5037 sctp_cmd_seq_t *commands)
5038{
5039 /* Stop the T5-shutdown guard timer. */
5040 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5041 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5042
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00005043 return sctp_sf_do_9_1_prm_abort(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005044}
5045
5046/*
5047 * sctp_sf_shutdown_sent_prm_abort
5048 *
5049 * Inputs
5050 * (endpoint, asoc)
5051 *
5052 * The RFC does not explicitly address this issue, but is the route through the
5053 * state table when someone issues an abort while in SHUTDOWN-SENT state.
5054 *
5055 * Outputs
5056 * (timers)
5057 */
5058sctp_disposition_t sctp_sf_shutdown_sent_prm_abort(
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00005059 struct net *net,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005060 const struct sctp_endpoint *ep,
5061 const struct sctp_association *asoc,
5062 const sctp_subtype_t type,
5063 void *arg,
5064 sctp_cmd_seq_t *commands)
5065{
5066 /* Stop the T2-shutdown timer. */
5067 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5068 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5069
5070 /* Stop the T5-shutdown guard timer. */
5071 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5072 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5073
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00005074 return sctp_sf_do_9_1_prm_abort(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005075}
5076
5077/*
5078 * sctp_sf_cookie_echoed_prm_abort
5079 *
5080 * Inputs
5081 * (endpoint, asoc)
5082 *
5083 * The RFC does not explcitly address this issue, but is the route through the
5084 * state table when someone issues an abort while in COOKIE_ECHOED state.
5085 *
5086 * Outputs
5087 * (timers)
5088 */
5089sctp_disposition_t sctp_sf_shutdown_ack_sent_prm_abort(
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00005090 struct net *net,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005091 const struct sctp_endpoint *ep,
5092 const struct sctp_association *asoc,
5093 const sctp_subtype_t type,
5094 void *arg,
5095 sctp_cmd_seq_t *commands)
5096{
5097 /* The same T2 timer, so we should be able to use
5098 * common function with the SHUTDOWN-SENT state.
5099 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00005100 return sctp_sf_shutdown_sent_prm_abort(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005101}
5102
5103/*
5104 * Process the REQUESTHEARTBEAT primitive
5105 *
5106 * 10.1 ULP-to-SCTP
5107 * J) Request Heartbeat
5108 *
5109 * Format: REQUESTHEARTBEAT(association id, destination transport address)
5110 *
5111 * -> result
5112 *
5113 * Instructs the local endpoint to perform a HeartBeat on the specified
5114 * destination transport address of the given association. The returned
5115 * result should indicate whether the transmission of the HEARTBEAT
5116 * chunk to the destination address is successful.
5117 *
5118 * Mandatory attributes:
5119 *
5120 * o association id - local handle to the SCTP association
5121 *
5122 * o destination transport address - the transport address of the
5123 * association on which a heartbeat should be issued.
5124 */
5125sctp_disposition_t sctp_sf_do_prm_requestheartbeat(
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00005126 struct net *net,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005127 const struct sctp_endpoint *ep,
5128 const struct sctp_association *asoc,
5129 const sctp_subtype_t type,
5130 void *arg,
5131 sctp_cmd_seq_t *commands)
5132{
Vlad Yasevichfb785252007-03-19 17:02:03 -07005133 if (SCTP_DISPOSITION_NOMEM == sctp_sf_heartbeat(ep, asoc, type,
5134 (struct sctp_transport *)arg, commands))
5135 return SCTP_DISPOSITION_NOMEM;
5136
5137 /*
5138 * RFC 2960 (bis), section 8.3
5139 *
5140 * D) Request an on-demand HEARTBEAT on a specific destination
5141 * transport address of a given association.
5142 *
5143 * The endpoint should increment the respective error counter of
5144 * the destination transport address each time a HEARTBEAT is sent
5145 * to that address and not acknowledged within one RTO.
5146 *
5147 */
Vlad Yasevich7e990132009-03-02 09:46:14 +00005148 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_HB_SENT,
Vlad Yasevichfb785252007-03-19 17:02:03 -07005149 SCTP_TRANSPORT(arg));
5150 return SCTP_DISPOSITION_CONSUME;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005151}
5152
5153/*
5154 * ADDIP Section 4.1 ASCONF Chunk Procedures
5155 * When an endpoint has an ASCONF signaled change to be sent to the
5156 * remote endpoint it should do A1 to A9
5157 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00005158sctp_disposition_t sctp_sf_do_prm_asconf(struct net *net,
5159 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005160 const struct sctp_association *asoc,
5161 const sctp_subtype_t type,
5162 void *arg,
5163 sctp_cmd_seq_t *commands)
5164{
5165 struct sctp_chunk *chunk = arg;
5166
5167 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
5168 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
5169 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
5170 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
5171 return SCTP_DISPOSITION_CONSUME;
5172}
5173
5174/*
5175 * Ignore the primitive event
5176 *
5177 * The return value is the disposition of the primitive.
5178 */
5179sctp_disposition_t sctp_sf_ignore_primitive(
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00005180 struct net *net,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005181 const struct sctp_endpoint *ep,
5182 const struct sctp_association *asoc,
5183 const sctp_subtype_t type,
5184 void *arg,
5185 sctp_cmd_seq_t *commands)
5186{
Daniel Borkmannbb333812013-06-28 19:49:40 +02005187 pr_debug("%s: primitive type:%d is ignored\n", __func__,
5188 type.primitive);
5189
Linus Torvalds1da177e2005-04-16 15:20:36 -07005190 return SCTP_DISPOSITION_DISCARD;
5191}
5192
5193/***************************************************************************
5194 * These are the state functions for the OTHER events.
5195 ***************************************************************************/
5196
5197/*
Wei Yongjune1cdd552011-04-17 17:29:03 +00005198 * When the SCTP stack has no more user data to send or retransmit, this
5199 * notification is given to the user. Also, at the time when a user app
5200 * subscribes to this event, if there is no data to be sent or
5201 * retransmit, the stack will immediately send up this notification.
5202 */
5203sctp_disposition_t sctp_sf_do_no_pending_tsn(
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00005204 struct net *net,
Wei Yongjune1cdd552011-04-17 17:29:03 +00005205 const struct sctp_endpoint *ep,
5206 const struct sctp_association *asoc,
5207 const sctp_subtype_t type,
5208 void *arg,
5209 sctp_cmd_seq_t *commands)
5210{
5211 struct sctp_ulpevent *event;
5212
5213 event = sctp_ulpevent_make_sender_dry_event(asoc, GFP_ATOMIC);
5214 if (!event)
5215 return SCTP_DISPOSITION_NOMEM;
5216
5217 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(event));
5218
5219 return SCTP_DISPOSITION_CONSUME;
5220}
5221
5222/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07005223 * Start the shutdown negotiation.
5224 *
5225 * From Section 9.2:
5226 * Once all its outstanding data has been acknowledged, the endpoint
5227 * shall send a SHUTDOWN chunk to its peer including in the Cumulative
5228 * TSN Ack field the last sequential TSN it has received from the peer.
5229 * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT
5230 * state. If the timer expires, the endpoint must re-send the SHUTDOWN
5231 * with the updated last sequential TSN received from its peer.
5232 *
5233 * The return value is the disposition.
5234 */
5235sctp_disposition_t sctp_sf_do_9_2_start_shutdown(
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00005236 struct net *net,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005237 const struct sctp_endpoint *ep,
5238 const struct sctp_association *asoc,
5239 const sctp_subtype_t type,
5240 void *arg,
5241 sctp_cmd_seq_t *commands)
5242{
5243 struct sctp_chunk *reply;
5244
5245 /* Once all its outstanding data has been acknowledged, the
5246 * endpoint shall send a SHUTDOWN chunk to its peer including
5247 * in the Cumulative TSN Ack field the last sequential TSN it
5248 * has received from the peer.
5249 */
5250 reply = sctp_make_shutdown(asoc, NULL);
5251 if (!reply)
5252 goto nomem;
5253
5254 /* Set the transport for the SHUTDOWN chunk and the timeout for the
5255 * T2-shutdown timer.
5256 */
5257 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5258
5259 /* It shall then start the T2-shutdown timer */
5260 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
5261 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5262
Wei Yongjun536428a2008-09-05 08:55:26 +08005263 /* RFC 4960 Section 9.2
5264 * The sender of the SHUTDOWN MAY also start an overall guard timer
5265 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5266 */
Thomas Graff8d96052011-07-07 00:28:35 +00005267 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
Wei Yongjun536428a2008-09-05 08:55:26 +08005268 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5269
Neil Horman9f70f462013-12-10 06:48:15 -05005270 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
Linus Torvalds1da177e2005-04-16 15:20:36 -07005271 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5272 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
5273
5274 /* and enter the SHUTDOWN-SENT state. */
5275 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5276 SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT));
5277
5278 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5279 *
5280 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09005281 * or SHUTDOWN-ACK.
Linus Torvalds1da177e2005-04-16 15:20:36 -07005282 */
5283 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
5284
5285 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5286
5287 return SCTP_DISPOSITION_CONSUME;
5288
5289nomem:
5290 return SCTP_DISPOSITION_NOMEM;
5291}
5292
5293/*
5294 * Generate a SHUTDOWN ACK now that everything is SACK'd.
5295 *
5296 * From Section 9.2:
5297 *
5298 * If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5299 * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own,
5300 * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the
5301 * endpoint must re-send the SHUTDOWN ACK.
5302 *
5303 * The return value is the disposition.
5304 */
5305sctp_disposition_t sctp_sf_do_9_2_shutdown_ack(
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00005306 struct net *net,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005307 const struct sctp_endpoint *ep,
5308 const struct sctp_association *asoc,
5309 const sctp_subtype_t type,
5310 void *arg,
5311 sctp_cmd_seq_t *commands)
5312{
5313 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
5314 struct sctp_chunk *reply;
5315
5316 /* There are 2 ways of getting here:
5317 * 1) called in response to a SHUTDOWN chunk
5318 * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued.
5319 *
5320 * For the case (2), the arg parameter is set to NULL. We need
5321 * to check that we have a chunk before accessing it's fields.
5322 */
5323 if (chunk) {
5324 if (!sctp_vtag_verify(chunk, asoc))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00005325 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005326
5327 /* Make sure that the SHUTDOWN chunk has a valid length. */
5328 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_shutdown_chunk_t)))
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00005329 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005330 commands);
5331 }
5332
5333 /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5334 * shall send a SHUTDOWN ACK ...
5335 */
5336 reply = sctp_make_shutdown_ack(asoc, chunk);
5337 if (!reply)
5338 goto nomem;
5339
5340 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
5341 * the T2-shutdown timer.
5342 */
5343 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5344
5345 /* and start/restart a T2-shutdown timer of its own, */
5346 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5347 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5348
Neil Horman9f70f462013-12-10 06:48:15 -05005349 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
Linus Torvalds1da177e2005-04-16 15:20:36 -07005350 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5351 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
5352
5353 /* Enter the SHUTDOWN-ACK-SENT state. */
5354 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5355 SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT));
5356
5357 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5358 *
5359 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09005360 * or SHUTDOWN-ACK.
Linus Torvalds1da177e2005-04-16 15:20:36 -07005361 */
5362 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
5363
5364 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5365
5366 return SCTP_DISPOSITION_CONSUME;
5367
5368nomem:
5369 return SCTP_DISPOSITION_NOMEM;
5370}
5371
5372/*
5373 * Ignore the event defined as other
5374 *
5375 * The return value is the disposition of the event.
5376 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00005377sctp_disposition_t sctp_sf_ignore_other(struct net *net,
5378 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005379 const struct sctp_association *asoc,
5380 const sctp_subtype_t type,
5381 void *arg,
5382 sctp_cmd_seq_t *commands)
5383{
Daniel Borkmannbb333812013-06-28 19:49:40 +02005384 pr_debug("%s: the event other type:%d is ignored\n",
5385 __func__, type.other);
5386
Linus Torvalds1da177e2005-04-16 15:20:36 -07005387 return SCTP_DISPOSITION_DISCARD;
5388}
5389
5390/************************************************************
5391 * These are the state functions for handling timeout events.
5392 ************************************************************/
5393
5394/*
5395 * RTX Timeout
5396 *
5397 * Section: 6.3.3 Handle T3-rtx Expiration
5398 *
5399 * Whenever the retransmission timer T3-rtx expires for a destination
5400 * address, do the following:
5401 * [See below]
5402 *
5403 * The return value is the disposition of the chunk.
5404 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00005405sctp_disposition_t sctp_sf_do_6_3_3_rtx(struct net *net,
5406 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005407 const struct sctp_association *asoc,
5408 const sctp_subtype_t type,
5409 void *arg,
5410 sctp_cmd_seq_t *commands)
5411{
5412 struct sctp_transport *transport = arg;
5413
Eric W. Biedermanb01a2402012-08-06 08:47:55 +00005414 SCTP_INC_STATS(net, SCTP_MIB_T3_RTX_EXPIREDS);
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07005415
Linus Torvalds1da177e2005-04-16 15:20:36 -07005416 if (asoc->overall_error_count >= asoc->max_retrans) {
Thomas Graff8d96052011-07-07 00:28:35 +00005417 if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING) {
5418 /*
5419 * We are here likely because the receiver had its rwnd
5420 * closed for a while and we have not been able to
5421 * transmit the locally queued data within the maximum
5422 * retransmission attempts limit. Start the T5
5423 * shutdown guard timer to give the receiver one last
5424 * chance and some additional time to recover before
5425 * aborting.
5426 */
5427 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START_ONCE,
5428 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5429 } else {
5430 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5431 SCTP_ERROR(ETIMEDOUT));
5432 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5433 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5434 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Eric W. Biedermanb01a2402012-08-06 08:47:55 +00005435 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5436 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
Thomas Graff8d96052011-07-07 00:28:35 +00005437 return SCTP_DISPOSITION_DELETE_TCB;
5438 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07005439 }
5440
5441 /* E1) For the destination address for which the timer
5442 * expires, adjust its ssthresh with rules defined in Section
5443 * 7.2.3 and set the cwnd <- MTU.
5444 */
5445
5446 /* E2) For the destination address for which the timer
5447 * expires, set RTO <- RTO * 2 ("back off the timer"). The
5448 * maximum value discussed in rule C7 above (RTO.max) may be
5449 * used to provide an upper bound to this doubling operation.
5450 */
5451
5452 /* E3) Determine how many of the earliest (i.e., lowest TSN)
5453 * outstanding DATA chunks for the address for which the
5454 * T3-rtx has expired will fit into a single packet, subject
5455 * to the MTU constraint for the path corresponding to the
5456 * destination transport address to which the retransmission
5457 * is being sent (this may be different from the address for
5458 * which the timer expires [see Section 6.4]). Call this
5459 * value K. Bundle and retransmit those K DATA chunks in a
5460 * single packet to the destination endpoint.
5461 *
5462 * Note: Any DATA chunks that were sent to the address for
5463 * which the T3-rtx timer expired but did not fit in one MTU
5464 * (rule E3 above), should be marked for retransmission and
5465 * sent as soon as cwnd allows (normally when a SACK arrives).
5466 */
5467
Linus Torvalds1da177e2005-04-16 15:20:36 -07005468 /* Do some failure management (Section 8.2). */
5469 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
5470
Vlad Yasevich1845a572007-02-21 02:06:19 -08005471 /* NB: Rules E4 and F1 are implicit in R1. */
5472 sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN, SCTP_TRANSPORT(transport));
5473
Linus Torvalds1da177e2005-04-16 15:20:36 -07005474 return SCTP_DISPOSITION_CONSUME;
5475}
5476
5477/*
5478 * Generate delayed SACK on timeout
5479 *
5480 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
5481 *
5482 * The guidelines on delayed acknowledgement algorithm specified in
5483 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
5484 * acknowledgement SHOULD be generated for at least every second packet
5485 * (not every second DATA chunk) received, and SHOULD be generated
5486 * within 200 ms of the arrival of any unacknowledged DATA chunk. In
5487 * some situations it may be beneficial for an SCTP transmitter to be
5488 * more conservative than the algorithms detailed in this document
5489 * allow. However, an SCTP transmitter MUST NOT be more aggressive than
5490 * the following algorithms allow.
5491 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00005492sctp_disposition_t sctp_sf_do_6_2_sack(struct net *net,
5493 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005494 const struct sctp_association *asoc,
5495 const sctp_subtype_t type,
5496 void *arg,
5497 sctp_cmd_seq_t *commands)
5498{
Eric W. Biedermanb01a2402012-08-06 08:47:55 +00005499 SCTP_INC_STATS(net, SCTP_MIB_DELAY_SACK_EXPIREDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005500 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
5501 return SCTP_DISPOSITION_CONSUME;
5502}
5503
5504/*
Frank Filz3f7a87d2005-06-20 13:14:57 -07005505 * sctp_sf_t1_init_timer_expire
Linus Torvalds1da177e2005-04-16 15:20:36 -07005506 *
5507 * Section: 4 Note: 2
5508 * Verification Tag:
5509 * Inputs
5510 * (endpoint, asoc)
5511 *
5512 * RFC 2960 Section 4 Notes
5513 * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT
5514 * and re-start the T1-init timer without changing state. This MUST
5515 * be repeated up to 'Max.Init.Retransmits' times. After that, the
5516 * endpoint MUST abort the initialization process and report the
5517 * error to SCTP user.
5518 *
Frank Filz3f7a87d2005-06-20 13:14:57 -07005519 * Outputs
5520 * (timers, events)
5521 *
5522 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00005523sctp_disposition_t sctp_sf_t1_init_timer_expire(struct net *net,
5524 const struct sctp_endpoint *ep,
Frank Filz3f7a87d2005-06-20 13:14:57 -07005525 const struct sctp_association *asoc,
5526 const sctp_subtype_t type,
5527 void *arg,
5528 sctp_cmd_seq_t *commands)
5529{
5530 struct sctp_chunk *repl = NULL;
5531 struct sctp_bind_addr *bp;
5532 int attempts = asoc->init_err_counter + 1;
5533
Daniel Borkmannbb333812013-06-28 19:49:40 +02005534 pr_debug("%s: timer T1 expired (INIT)\n", __func__);
5535
Eric W. Biedermanb01a2402012-08-06 08:47:55 +00005536 SCTP_INC_STATS(net, SCTP_MIB_T1_INIT_EXPIREDS);
Frank Filz3f7a87d2005-06-20 13:14:57 -07005537
Vlad Yasevich81845c22006-01-30 15:59:54 -08005538 if (attempts <= asoc->max_init_attempts) {
Frank Filz3f7a87d2005-06-20 13:14:57 -07005539 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
5540 repl = sctp_make_init(asoc, bp, GFP_ATOMIC, 0);
5541 if (!repl)
5542 return SCTP_DISPOSITION_NOMEM;
5543
5544 /* Choose transport for INIT. */
5545 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
5546 SCTP_CHUNK(repl));
5547
5548 /* Issue a sideeffect to do the needed accounting. */
5549 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_RESTART,
5550 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
5551
5552 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
5553 } else {
Daniel Borkmannbb333812013-06-28 19:49:40 +02005554 pr_debug("%s: giving up on INIT, attempts:%d "
5555 "max_init_attempts:%d\n", __func__, attempts,
5556 asoc->max_init_attempts);
5557
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07005558 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5559 SCTP_ERROR(ETIMEDOUT));
Frank Filz3f7a87d2005-06-20 13:14:57 -07005560 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08005561 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Frank Filz3f7a87d2005-06-20 13:14:57 -07005562 return SCTP_DISPOSITION_DELETE_TCB;
5563 }
5564
5565 return SCTP_DISPOSITION_CONSUME;
5566}
5567
5568/*
5569 * sctp_sf_t1_cookie_timer_expire
5570 *
5571 * Section: 4 Note: 2
5572 * Verification Tag:
5573 * Inputs
5574 * (endpoint, asoc)
5575 *
5576 * RFC 2960 Section 4 Notes
5577 * 3) If the T1-cookie timer expires, the endpoint MUST retransmit
Linus Torvalds1da177e2005-04-16 15:20:36 -07005578 * COOKIE ECHO and re-start the T1-cookie timer without changing
5579 * state. This MUST be repeated up to 'Max.Init.Retransmits' times.
5580 * After that, the endpoint MUST abort the initialization process and
5581 * report the error to SCTP user.
5582 *
5583 * Outputs
5584 * (timers, events)
5585 *
5586 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00005587sctp_disposition_t sctp_sf_t1_cookie_timer_expire(struct net *net,
5588 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005589 const struct sctp_association *asoc,
5590 const sctp_subtype_t type,
5591 void *arg,
5592 sctp_cmd_seq_t *commands)
5593{
Frank Filz3f7a87d2005-06-20 13:14:57 -07005594 struct sctp_chunk *repl = NULL;
5595 int attempts = asoc->init_err_counter + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005596
Daniel Borkmannbb333812013-06-28 19:49:40 +02005597 pr_debug("%s: timer T1 expired (COOKIE-ECHO)\n", __func__);
5598
Eric W. Biedermanb01a2402012-08-06 08:47:55 +00005599 SCTP_INC_STATS(net, SCTP_MIB_T1_COOKIE_EXPIREDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005600
Vlad Yasevich81845c22006-01-30 15:59:54 -08005601 if (attempts <= asoc->max_init_attempts) {
Frank Filz3f7a87d2005-06-20 13:14:57 -07005602 repl = sctp_make_cookie_echo(asoc, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005603 if (!repl)
Frank Filz3f7a87d2005-06-20 13:14:57 -07005604 return SCTP_DISPOSITION_NOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005605
Vlad Yasevich96cd0d32008-09-08 14:00:26 -04005606 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
5607 SCTP_CHUNK(repl));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005608 /* Issue a sideeffect to do the needed accounting. */
Frank Filz3f7a87d2005-06-20 13:14:57 -07005609 sctp_add_cmd_sf(commands, SCTP_CMD_COOKIEECHO_RESTART,
5610 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
5611
Linus Torvalds1da177e2005-04-16 15:20:36 -07005612 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
5613 } else {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07005614 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5615 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005616 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08005617 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005618 return SCTP_DISPOSITION_DELETE_TCB;
5619 }
5620
5621 return SCTP_DISPOSITION_CONSUME;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005622}
5623
5624/* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN
5625 * with the updated last sequential TSN received from its peer.
5626 *
5627 * An endpoint should limit the number of retransmissions of the
5628 * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'.
5629 * If this threshold is exceeded the endpoint should destroy the TCB and
5630 * MUST report the peer endpoint unreachable to the upper layer (and
5631 * thus the association enters the CLOSED state). The reception of any
5632 * packet from its peer (i.e. as the peer sends all of its queued DATA
5633 * chunks) should clear the endpoint's retransmission count and restart
5634 * the T2-Shutdown timer, giving its peer ample opportunity to transmit
5635 * all of its queued DATA chunks that have not yet been sent.
5636 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00005637sctp_disposition_t sctp_sf_t2_timer_expire(struct net *net,
5638 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005639 const struct sctp_association *asoc,
5640 const sctp_subtype_t type,
5641 void *arg,
5642 sctp_cmd_seq_t *commands)
5643{
5644 struct sctp_chunk *reply = NULL;
5645
Daniel Borkmannbb333812013-06-28 19:49:40 +02005646 pr_debug("%s: timer T2 expired\n", __func__);
5647
Eric W. Biedermanb01a2402012-08-06 08:47:55 +00005648 SCTP_INC_STATS(net, SCTP_MIB_T2_SHUTDOWN_EXPIREDS);
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07005649
Neil Horman58fbbed2008-02-29 11:40:56 -08005650 ((struct sctp_association *)asoc)->shutdown_retries++;
5651
Linus Torvalds1da177e2005-04-16 15:20:36 -07005652 if (asoc->overall_error_count >= asoc->max_retrans) {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07005653 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5654 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005655 /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5656 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08005657 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Eric W. Biedermanb01a2402012-08-06 08:47:55 +00005658 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5659 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005660 return SCTP_DISPOSITION_DELETE_TCB;
5661 }
5662
5663 switch (asoc->state) {
5664 case SCTP_STATE_SHUTDOWN_SENT:
5665 reply = sctp_make_shutdown(asoc, NULL);
5666 break;
5667
5668 case SCTP_STATE_SHUTDOWN_ACK_SENT:
5669 reply = sctp_make_shutdown_ack(asoc, NULL);
5670 break;
5671
5672 default:
5673 BUG();
5674 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07005675 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07005676
5677 if (!reply)
5678 goto nomem;
5679
Wei Yongjun6345b192009-04-26 23:13:35 +08005680 /* Do some failure management (Section 8.2).
5681 * If we remove the transport an SHUTDOWN was last sent to, don't
5682 * do failure management.
5683 */
5684 if (asoc->shutdown_last_sent_to)
5685 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
5686 SCTP_TRANSPORT(asoc->shutdown_last_sent_to));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005687
5688 /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for
5689 * the T2-shutdown timer.
5690 */
5691 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5692
5693 /* Restart the T2-shutdown timer. */
5694 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5695 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5696 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5697 return SCTP_DISPOSITION_CONSUME;
5698
5699nomem:
5700 return SCTP_DISPOSITION_NOMEM;
5701}
5702
5703/*
5704 * ADDIP Section 4.1 ASCONF CHunk Procedures
5705 * If the T4 RTO timer expires the endpoint should do B1 to B5
5706 */
5707sctp_disposition_t sctp_sf_t4_timer_expire(
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00005708 struct net *net,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005709 const struct sctp_endpoint *ep,
5710 const struct sctp_association *asoc,
5711 const sctp_subtype_t type,
5712 void *arg,
5713 sctp_cmd_seq_t *commands)
5714{
5715 struct sctp_chunk *chunk = asoc->addip_last_asconf;
5716 struct sctp_transport *transport = chunk->transport;
5717
Eric W. Biedermanb01a2402012-08-06 08:47:55 +00005718 SCTP_INC_STATS(net, SCTP_MIB_T4_RTO_EXPIREDS);
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07005719
Linus Torvalds1da177e2005-04-16 15:20:36 -07005720 /* ADDIP 4.1 B1) Increment the error counters and perform path failure
5721 * detection on the appropriate destination address as defined in
5722 * RFC2960 [5] section 8.1 and 8.2.
5723 */
Wei Yongjun10a43ce2009-04-26 23:14:42 +08005724 if (transport)
5725 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
5726 SCTP_TRANSPORT(transport));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005727
5728 /* Reconfig T4 timer and transport. */
5729 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
5730
5731 /* ADDIP 4.1 B2) Increment the association error counters and perform
5732 * endpoint failure detection on the association as defined in
5733 * RFC2960 [5] section 8.1 and 8.2.
5734 * association error counter is incremented in SCTP_CMD_STRIKE.
5735 */
5736 if (asoc->overall_error_count >= asoc->max_retrans) {
5737 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5738 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07005739 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5740 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005741 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08005742 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Eric W. Biedermanb01a2402012-08-06 08:47:55 +00005743 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5744 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005745 return SCTP_DISPOSITION_ABORT;
5746 }
5747
5748 /* ADDIP 4.1 B3) Back-off the destination address RTO value to which
5749 * the ASCONF chunk was sent by doubling the RTO timer value.
5750 * This is done in SCTP_CMD_STRIKE.
5751 */
5752
5753 /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible
5754 * choose an alternate destination address (please refer to RFC2960
5755 * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09005756 * chunk, it MUST be the same (including its serial number) as the last
Linus Torvalds1da177e2005-04-16 15:20:36 -07005757 * ASCONF sent.
5758 */
5759 sctp_chunk_hold(asoc->addip_last_asconf);
5760 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
5761 SCTP_CHUNK(asoc->addip_last_asconf));
5762
5763 /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different
5764 * destination is selected, then the RTO used will be that of the new
5765 * destination address.
5766 */
5767 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5768 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
5769
5770 return SCTP_DISPOSITION_CONSUME;
5771}
5772
5773/* sctpimpguide-05 Section 2.12.2
5774 * The sender of the SHUTDOWN MAY also start an overall guard timer
5775 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5776 * At the expiration of this timer the sender SHOULD abort the association
5777 * by sending an ABORT chunk.
5778 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00005779sctp_disposition_t sctp_sf_t5_timer_expire(struct net *net,
5780 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005781 const struct sctp_association *asoc,
5782 const sctp_subtype_t type,
5783 void *arg,
5784 sctp_cmd_seq_t *commands)
5785{
5786 struct sctp_chunk *reply = NULL;
5787
Daniel Borkmannbb333812013-06-28 19:49:40 +02005788 pr_debug("%s: timer T5 expired\n", __func__);
5789
Eric W. Biedermanb01a2402012-08-06 08:47:55 +00005790 SCTP_INC_STATS(net, SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005791
5792 reply = sctp_make_abort(asoc, NULL, 0);
5793 if (!reply)
5794 goto nomem;
5795
5796 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07005797 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5798 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005799 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08005800 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005801
Eric W. Biedermanb01a2402012-08-06 08:47:55 +00005802 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5803 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
Vlad Yasevicha1080a82008-10-09 14:33:26 -07005804
Linus Torvalds1da177e2005-04-16 15:20:36 -07005805 return SCTP_DISPOSITION_DELETE_TCB;
5806nomem:
5807 return SCTP_DISPOSITION_NOMEM;
5808}
5809
5810/* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires,
5811 * the association is automatically closed by starting the shutdown process.
5812 * The work that needs to be done is same as when SHUTDOWN is initiated by
5813 * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown().
5814 */
5815sctp_disposition_t sctp_sf_autoclose_timer_expire(
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00005816 struct net *net,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005817 const struct sctp_endpoint *ep,
5818 const struct sctp_association *asoc,
5819 const sctp_subtype_t type,
5820 void *arg,
5821 sctp_cmd_seq_t *commands)
5822{
5823 int disposition;
5824
Eric W. Biedermanb01a2402012-08-06 08:47:55 +00005825 SCTP_INC_STATS(net, SCTP_MIB_AUTOCLOSE_EXPIREDS);
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07005826
Linus Torvalds1da177e2005-04-16 15:20:36 -07005827 /* From 9.2 Shutdown of an Association
5828 * Upon receipt of the SHUTDOWN primitive from its upper
5829 * layer, the endpoint enters SHUTDOWN-PENDING state and
5830 * remains there until all outstanding data has been
5831 * acknowledged by its peer. The endpoint accepts no new data
5832 * from its upper layer, but retransmits data to the far end
5833 * if necessary to fill gaps.
5834 */
5835 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5836 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
5837
Linus Torvalds1da177e2005-04-16 15:20:36 -07005838 disposition = SCTP_DISPOSITION_CONSUME;
5839 if (sctp_outq_is_empty(&asoc->outqueue)) {
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00005840 disposition = sctp_sf_do_9_2_start_shutdown(net, ep, asoc, type,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005841 arg, commands);
5842 }
5843 return disposition;
5844}
5845
5846/*****************************************************************************
5847 * These are sa state functions which could apply to all types of events.
5848 ****************************************************************************/
5849
5850/*
5851 * This table entry is not implemented.
5852 *
5853 * Inputs
5854 * (endpoint, asoc, chunk)
5855 *
5856 * The return value is the disposition of the chunk.
5857 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00005858sctp_disposition_t sctp_sf_not_impl(struct net *net,
5859 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005860 const struct sctp_association *asoc,
5861 const sctp_subtype_t type,
5862 void *arg,
5863 sctp_cmd_seq_t *commands)
5864{
5865 return SCTP_DISPOSITION_NOT_IMPL;
5866}
5867
5868/*
5869 * This table entry represents a bug.
5870 *
5871 * Inputs
5872 * (endpoint, asoc, chunk)
5873 *
5874 * The return value is the disposition of the chunk.
5875 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00005876sctp_disposition_t sctp_sf_bug(struct net *net,
5877 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005878 const struct sctp_association *asoc,
5879 const sctp_subtype_t type,
5880 void *arg,
5881 sctp_cmd_seq_t *commands)
5882{
5883 return SCTP_DISPOSITION_BUG;
5884}
5885
5886/*
5887 * This table entry represents the firing of a timer in the wrong state.
5888 * Since timer deletion cannot be guaranteed a timer 'may' end up firing
5889 * when the association is in the wrong state. This event should
5890 * be ignored, so as to prevent any rearming of the timer.
5891 *
5892 * Inputs
5893 * (endpoint, asoc, chunk)
5894 *
5895 * The return value is the disposition of the chunk.
5896 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00005897sctp_disposition_t sctp_sf_timer_ignore(struct net *net,
5898 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005899 const struct sctp_association *asoc,
5900 const sctp_subtype_t type,
5901 void *arg,
5902 sctp_cmd_seq_t *commands)
5903{
Daniel Borkmannbb333812013-06-28 19:49:40 +02005904 pr_debug("%s: timer %d ignored\n", __func__, type.chunk);
5905
Linus Torvalds1da177e2005-04-16 15:20:36 -07005906 return SCTP_DISPOSITION_CONSUME;
5907}
5908
5909/********************************************************************
5910 * 2nd Level Abstractions
5911 ********************************************************************/
5912
5913/* Pull the SACK chunk based on the SACK header. */
5914static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk)
5915{
5916 struct sctp_sackhdr *sack;
5917 unsigned int len;
5918 __u16 num_blocks;
5919 __u16 num_dup_tsns;
5920
5921 /* Protect ourselves from reading too far into
5922 * the skb from a bogus sender.
5923 */
5924 sack = (struct sctp_sackhdr *) chunk->skb->data;
5925
5926 num_blocks = ntohs(sack->num_gap_ack_blocks);
5927 num_dup_tsns = ntohs(sack->num_dup_tsns);
5928 len = sizeof(struct sctp_sackhdr);
5929 len += (num_blocks + num_dup_tsns) * sizeof(__u32);
5930 if (len > chunk->skb->len)
5931 return NULL;
5932
5933 skb_pull(chunk->skb, len);
5934
5935 return sack;
5936}
5937
5938/* Create an ABORT packet to be sent as a response, with the specified
5939 * error causes.
5940 */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00005941static struct sctp_packet *sctp_abort_pkt_new(struct net *net,
5942 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005943 const struct sctp_association *asoc,
5944 struct sctp_chunk *chunk,
5945 const void *payload,
5946 size_t paylen)
5947{
5948 struct sctp_packet *packet;
5949 struct sctp_chunk *abort;
5950
Eric W. Biederman2ce95502012-08-06 08:43:06 +00005951 packet = sctp_ootb_pkt_new(net, asoc, chunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005952
5953 if (packet) {
5954 /* Make an ABORT.
5955 * The T bit will be set if the asoc is NULL.
5956 */
5957 abort = sctp_make_abort(asoc, chunk, paylen);
5958 if (!abort) {
5959 sctp_ootb_pkt_free(packet);
5960 return NULL;
5961 }
Jerome Forissier047a2422005-04-28 11:58:43 -07005962
5963 /* Reflect vtag if T-Bit is set */
5964 if (sctp_test_T_bit(abort))
5965 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
5966
Linus Torvalds1da177e2005-04-16 15:20:36 -07005967 /* Add specified error causes, i.e., payload, to the
5968 * end of the chunk.
5969 */
5970 sctp_addto_chunk(abort, paylen, payload);
5971
5972 /* Set the skb to the belonging sock for accounting. */
5973 abort->skb->sk = ep->base.sk;
5974
5975 sctp_packet_append_chunk(packet, abort);
5976
5977 }
5978
5979 return packet;
5980}
5981
5982/* Allocate a packet for responding in the OOTB conditions. */
Eric W. Biederman2ce95502012-08-06 08:43:06 +00005983static struct sctp_packet *sctp_ootb_pkt_new(struct net *net,
5984 const struct sctp_association *asoc,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005985 const struct sctp_chunk *chunk)
5986{
5987 struct sctp_packet *packet;
5988 struct sctp_transport *transport;
5989 __u16 sport;
5990 __u16 dport;
5991 __u32 vtag;
5992
5993 /* Get the source and destination port from the inbound packet. */
5994 sport = ntohs(chunk->sctp_hdr->dest);
5995 dport = ntohs(chunk->sctp_hdr->source);
5996
5997 /* The V-tag is going to be the same as the inbound packet if no
5998 * association exists, otherwise, use the peer's vtag.
5999 */
6000 if (asoc) {
Wei Yongjun02c4e122007-08-31 10:03:58 +08006001 /* Special case the INIT-ACK as there is no peer's vtag
6002 * yet.
6003 */
wangweidongcb3f8372013-12-23 12:16:50 +08006004 switch (chunk->chunk_hdr->type) {
Wei Yongjun02c4e122007-08-31 10:03:58 +08006005 case SCTP_CID_INIT_ACK:
6006 {
6007 sctp_initack_chunk_t *initack;
6008
6009 initack = (sctp_initack_chunk_t *)chunk->chunk_hdr;
6010 vtag = ntohl(initack->init_hdr.init_tag);
6011 break;
6012 }
6013 default:
6014 vtag = asoc->peer.i.init_tag;
6015 break;
6016 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07006017 } else {
6018 /* Special case the INIT and stale COOKIE_ECHO as there is no
6019 * vtag yet.
6020 */
wangweidongcb3f8372013-12-23 12:16:50 +08006021 switch (chunk->chunk_hdr->type) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07006022 case SCTP_CID_INIT:
6023 {
6024 sctp_init_chunk_t *init;
6025
6026 init = (sctp_init_chunk_t *)chunk->chunk_hdr;
6027 vtag = ntohl(init->init_hdr.init_tag);
6028 break;
6029 }
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09006030 default:
Linus Torvalds1da177e2005-04-16 15:20:36 -07006031 vtag = ntohl(chunk->sctp_hdr->vtag);
6032 break;
6033 }
6034 }
6035
6036 /* Make a transport for the bucket, Eliza... */
Eric W. Biederman89bf3452012-08-07 07:26:14 +00006037 transport = sctp_transport_new(net, sctp_source(chunk), GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07006038 if (!transport)
6039 goto nomem;
6040
6041 /* Cache a route for the transport with the chunk's destination as
6042 * the source address.
6043 */
Al Viro16b0a032006-11-20 17:13:38 -08006044 sctp_transport_route(transport, (union sctp_addr *)&chunk->dest,
Eric W. Biederman2ce95502012-08-06 08:43:06 +00006045 sctp_sk(net->sctp.ctl_sock));
Linus Torvalds1da177e2005-04-16 15:20:36 -07006046
6047 packet = sctp_packet_init(&transport->packet, transport, sport, dport);
6048 packet = sctp_packet_config(packet, vtag, 0);
6049
6050 return packet;
6051
6052nomem:
6053 return NULL;
6054}
6055
6056/* Free the packet allocated earlier for responding in the OOTB condition. */
6057void sctp_ootb_pkt_free(struct sctp_packet *packet)
6058{
6059 sctp_transport_free(packet->transport);
6060}
6061
6062/* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00006063static void sctp_send_stale_cookie_err(struct net *net,
6064 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07006065 const struct sctp_association *asoc,
6066 const struct sctp_chunk *chunk,
6067 sctp_cmd_seq_t *commands,
6068 struct sctp_chunk *err_chunk)
6069{
6070 struct sctp_packet *packet;
6071
6072 if (err_chunk) {
Eric W. Biederman2ce95502012-08-06 08:43:06 +00006073 packet = sctp_ootb_pkt_new(net, asoc, chunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -07006074 if (packet) {
6075 struct sctp_signed_cookie *cookie;
6076
6077 /* Override the OOTB vtag from the cookie. */
6078 cookie = chunk->subh.cookie_hdr;
6079 packet->vtag = cookie->c.peer_vtag;
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09006080
Linus Torvalds1da177e2005-04-16 15:20:36 -07006081 /* Set the skb to the belonging sock for accounting. */
6082 err_chunk->skb->sk = ep->base.sk;
6083 sctp_packet_append_chunk(packet, err_chunk);
6084 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
6085 SCTP_PACKET(packet));
Eric W. Biedermanb01a2402012-08-06 08:47:55 +00006086 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07006087 } else
6088 sctp_chunk_free (err_chunk);
6089 }
6090}
6091
6092
6093/* Process a data chunk */
6094static int sctp_eat_data(const struct sctp_association *asoc,
6095 struct sctp_chunk *chunk,
6096 sctp_cmd_seq_t *commands)
6097{
6098 sctp_datahdr_t *data_hdr;
6099 struct sctp_chunk *err;
6100 size_t datalen;
6101 sctp_verb_t deliver;
6102 int tmp;
6103 __u32 tsn;
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07006104 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
Neil Horman049b3ff2005-11-11 16:08:24 -08006105 struct sock *sk = asoc->base.sk;
Eric W. Biederman24cb81a2012-08-07 07:28:09 +00006106 struct net *net = sock_net(sk);
Vlad Yasevichf1751c52009-09-04 18:21:03 -04006107 u16 ssn;
6108 u16 sid;
6109 u8 ordered = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07006110
6111 data_hdr = chunk->subh.data_hdr = (sctp_datahdr_t *)chunk->skb->data;
6112 skb_pull(chunk->skb, sizeof(sctp_datahdr_t));
6113
6114 tsn = ntohl(data_hdr->tsn);
Daniel Borkmannbb333812013-06-28 19:49:40 +02006115 pr_debug("%s: TSN 0x%x\n", __func__, tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07006116
6117 /* ASSERT: Now skb->data is really the user data. */
6118
Linus Torvalds1da177e2005-04-16 15:20:36 -07006119 /* Process ECN based congestion.
6120 *
6121 * Since the chunk structure is reused for all chunks within
6122 * a packet, we use ecn_ce_done to track if we've already
6123 * done CE processing for this packet.
6124 *
6125 * We need to do ECN processing even if we plan to discard the
6126 * chunk later.
6127 */
6128
6129 if (!chunk->ecn_ce_done) {
6130 struct sctp_af *af;
6131 chunk->ecn_ce_done = 1;
6132
6133 af = sctp_get_af_specific(
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07006134 ipver2af(ip_hdr(chunk->skb)->version));
Linus Torvalds1da177e2005-04-16 15:20:36 -07006135
6136 if (af && af->is_ce(chunk->skb) && asoc->peer.ecn_capable) {
6137 /* Do real work as sideffect. */
6138 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_CE,
6139 SCTP_U32(tsn));
6140 }
6141 }
6142
6143 tmp = sctp_tsnmap_check(&asoc->peer.tsn_map, tsn);
6144 if (tmp < 0) {
6145 /* The TSN is too high--silently discard the chunk and
6146 * count on it getting retransmitted later.
6147 */
Michele Baldessari196d6752012-12-01 04:49:42 +00006148 if (chunk->asoc)
6149 chunk->asoc->stats.outofseqtsns++;
Linus Torvalds1da177e2005-04-16 15:20:36 -07006150 return SCTP_IERROR_HIGH_TSN;
6151 } else if (tmp > 0) {
6152 /* This is a duplicate. Record it. */
6153 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_DUP, SCTP_U32(tsn));
6154 return SCTP_IERROR_DUP_TSN;
6155 }
6156
6157 /* This is a new TSN. */
6158
6159 /* Discard if there is no room in the receive window.
6160 * Actually, allow a little bit of overflow (up to a MTU).
6161 */
6162 datalen = ntohs(chunk->chunk_hdr->length);
6163 datalen -= sizeof(sctp_data_chunk_t);
6164
6165 deliver = SCTP_CMD_CHUNK_ULP;
6166
6167 /* Think about partial delivery. */
6168 if ((datalen >= asoc->rwnd) && (!asoc->ulpq.pd_mode)) {
6169
6170 /* Even if we don't accept this chunk there is
6171 * memory pressure.
6172 */
6173 sctp_add_cmd_sf(commands, SCTP_CMD_PART_DELIVER, SCTP_NULL());
6174 }
6175
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09006176 /* Spill over rwnd a little bit. Note: While allowed, this spill over
Linus Torvalds1da177e2005-04-16 15:20:36 -07006177 * seems a bit troublesome in that frag_point varies based on
6178 * PMTU. In cases, such as loopback, this might be a rather
6179 * large spill over.
6180 */
Matija Glavinic Pecoticef2820a2014-02-14 14:51:18 +01006181 if ((!chunk->data_accepted) && (!asoc->rwnd ||
Neil Horman4d93df02007-08-15 16:07:44 -07006182 (datalen > asoc->rwnd + asoc->frag_point))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07006183
6184 /* If this is the next TSN, consider reneging to make
6185 * room. Note: Playing nice with a confused sender. A
6186 * malicious sender can still eat up all our buffer
6187 * space and in the future we may want to detect and
6188 * do more drastic reneging.
6189 */
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07006190 if (sctp_tsnmap_has_gap(map) &&
6191 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
Daniel Borkmannbb333812013-06-28 19:49:40 +02006192 pr_debug("%s: reneging for tsn:%u\n", __func__, tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07006193 deliver = SCTP_CMD_RENEGE;
6194 } else {
Daniel Borkmannbb333812013-06-28 19:49:40 +02006195 pr_debug("%s: discard tsn:%u len:%zu, rwnd:%d\n",
6196 __func__, tsn, datalen, asoc->rwnd);
6197
Linus Torvalds1da177e2005-04-16 15:20:36 -07006198 return SCTP_IERROR_IGNORE_TSN;
6199 }
6200 }
6201
6202 /*
Neil Horman4d93df02007-08-15 16:07:44 -07006203 * Also try to renege to limit our memory usage in the event that
6204 * we are under memory pressure
Hideo Aoki3ab224b2007-12-31 00:11:19 -08006205 * If we can't renege, don't worry about it, the sk_rmem_schedule
Neil Horman4d93df02007-08-15 16:07:44 -07006206 * in sctp_ulpevent_make_rcvmsg will drop the frame if we grow our
6207 * memory usage too much
6208 */
6209 if (*sk->sk_prot_creator->memory_pressure) {
6210 if (sctp_tsnmap_has_gap(map) &&
wangweidongf7010e62013-12-23 12:16:52 +08006211 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
Daniel Borkmannbb333812013-06-28 19:49:40 +02006212 pr_debug("%s: under pressure, reneging for tsn:%u\n",
6213 __func__, tsn);
Neil Horman4d93df02007-08-15 16:07:44 -07006214 deliver = SCTP_CMD_RENEGE;
6215 }
6216 }
6217
6218 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -07006219 * Section 3.3.10.9 No User Data (9)
6220 *
6221 * Cause of error
6222 * ---------------
6223 * No User Data: This error cause is returned to the originator of a
6224 * DATA chunk if a received DATA chunk has no user data.
6225 */
6226 if (unlikely(0 == datalen)) {
6227 err = sctp_make_abort_no_data(asoc, chunk, tsn);
6228 if (err) {
6229 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
6230 SCTP_CHUNK(err));
6231 }
6232 /* We are going to ABORT, so we might as well stop
6233 * processing the rest of the chunks in the packet.
6234 */
wangweidongcb3f8372013-12-23 12:16:50 +08006235 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07006236 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
6237 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07006238 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08006239 SCTP_PERR(SCTP_ERROR_NO_DATA));
Eric W. Biedermanb01a2402012-08-06 08:47:55 +00006240 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
6241 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
Linus Torvalds1da177e2005-04-16 15:20:36 -07006242 return SCTP_IERROR_NO_DATA;
6243 }
6244
Sridhar Samudrala9faa7302006-07-21 14:49:07 -07006245 chunk->data_accepted = 1;
6246
Linus Torvalds1da177e2005-04-16 15:20:36 -07006247 /* Note: Some chunks may get overcounted (if we drop) or overcounted
6248 * if we renege and the chunk arrives again.
6249 */
Michele Baldessari196d6752012-12-01 04:49:42 +00006250 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
Eric W. Biedermanb01a2402012-08-06 08:47:55 +00006251 SCTP_INC_STATS(net, SCTP_MIB_INUNORDERCHUNKS);
Michele Baldessari196d6752012-12-01 04:49:42 +00006252 if (chunk->asoc)
6253 chunk->asoc->stats.iuodchunks++;
6254 } else {
Eric W. Biedermanb01a2402012-08-06 08:47:55 +00006255 SCTP_INC_STATS(net, SCTP_MIB_INORDERCHUNKS);
Michele Baldessari196d6752012-12-01 04:49:42 +00006256 if (chunk->asoc)
6257 chunk->asoc->stats.iodchunks++;
Vlad Yasevichf1751c52009-09-04 18:21:03 -04006258 ordered = 1;
6259 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07006260
6261 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
6262 *
6263 * If an endpoint receive a DATA chunk with an invalid stream
6264 * identifier, it shall acknowledge the reception of the DATA chunk
6265 * following the normal procedure, immediately send an ERROR chunk
6266 * with cause set to "Invalid Stream Identifier" (See Section 3.3.10)
6267 * and discard the DATA chunk.
6268 */
Vlad Yasevichf1751c52009-09-04 18:21:03 -04006269 sid = ntohs(data_hdr->stream);
6270 if (sid >= asoc->c.sinit_max_instreams) {
Vlad Yasevich3888e9e2008-07-08 02:28:39 -07006271 /* Mark tsn as received even though we drop it */
6272 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_TSN, SCTP_U32(tsn));
6273
Linus Torvalds1da177e2005-04-16 15:20:36 -07006274 err = sctp_make_op_error(asoc, chunk, SCTP_ERROR_INV_STRM,
6275 &data_hdr->stream,
Vlad Yasevich6383cfb2009-11-23 15:53:56 -05006276 sizeof(data_hdr->stream),
6277 sizeof(u16));
Linus Torvalds1da177e2005-04-16 15:20:36 -07006278 if (err)
6279 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
6280 SCTP_CHUNK(err));
6281 return SCTP_IERROR_BAD_STREAM;
6282 }
6283
Vlad Yasevichf1751c52009-09-04 18:21:03 -04006284 /* Check to see if the SSN is possible for this TSN.
6285 * The biggest gap we can record is 4K wide. Since SSNs wrap
6286 * at an unsigned short, there is no way that an SSN can
6287 * wrap and for a valid TSN. We can simply check if the current
6288 * SSN is smaller then the next expected one. If it is, it wrapped
6289 * and is invalid.
6290 */
6291 ssn = ntohs(data_hdr->ssn);
6292 if (ordered && SSN_lt(ssn, sctp_ssn_peek(&asoc->ssnmap->in, sid))) {
6293 return SCTP_IERROR_PROTO_VIOLATION;
6294 }
6295
Linus Torvalds1da177e2005-04-16 15:20:36 -07006296 /* Send the data up to the user. Note: Schedule the
6297 * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK
6298 * chunk needs the updated rwnd.
6299 */
6300 sctp_add_cmd_sf(commands, deliver, SCTP_CHUNK(chunk));
6301
6302 return SCTP_IERROR_NO_ERROR;
6303}