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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
25 * along with GNU CC; see the file COPYING. If not, write to
26 * the Free Software Foundation, 59 Temple Place - Suite 330,
27 * Boston, MA 02111-1307, USA.
28 *
29 * Please send any bug reports or fixes you make to the
30 * email address(es):
31 * lksctp developers <lksctp-developers@lists.sourceforge.net>
32 *
33 * Or submit a bug report through the following website:
34 * http://www.sf.net/projects/lksctp
35 *
36 * Written or modified by:
37 * La Monte H.P. Yarroll <piggy@acm.org>
38 * Karl Knutson <karl@athena.chicago.il.us>
39 * Mathew Kotowsky <kotowsky@sctp.org>
40 * Sridhar Samudrala <samudrala@us.ibm.com>
41 * Jon Grimm <jgrimm@us.ibm.com>
42 * Hui Huang <hui.huang@nokia.com>
43 * Dajiang Zhang <dajiang.zhang@nokia.com>
44 * Daisy Chang <daisyc@us.ibm.com>
45 * Ardelle Fan <ardelle.fan@intel.com>
46 * Ryan Layer <rmlayer@us.ibm.com>
47 * Kevin Gao <kevin.gao@intel.com>
48 *
49 * Any bugs reported given to us we will try to fix... any fixes shared will
50 * be incorporated into the next SCTP release.
51 */
52
53#include <linux/types.h>
54#include <linux/kernel.h>
55#include <linux/ip.h>
56#include <linux/ipv6.h>
57#include <linux/net.h>
58#include <linux/inet.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090059#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070060#include <net/sock.h>
61#include <net/inet_ecn.h>
62#include <linux/skbuff.h>
63#include <net/sctp/sctp.h>
64#include <net/sctp/sm.h>
65#include <net/sctp/structs.h>
66
67static struct sctp_packet *sctp_abort_pkt_new(const struct sctp_endpoint *ep,
68 const struct sctp_association *asoc,
69 struct sctp_chunk *chunk,
70 const void *payload,
71 size_t paylen);
72static int sctp_eat_data(const struct sctp_association *asoc,
73 struct sctp_chunk *chunk,
74 sctp_cmd_seq_t *commands);
75static struct sctp_packet *sctp_ootb_pkt_new(const struct sctp_association *asoc,
76 const struct sctp_chunk *chunk);
77static void sctp_send_stale_cookie_err(const struct sctp_endpoint *ep,
78 const struct sctp_association *asoc,
79 const struct sctp_chunk *chunk,
80 sctp_cmd_seq_t *commands,
81 struct sctp_chunk *err_chunk);
82static sctp_disposition_t sctp_sf_do_5_2_6_stale(const struct sctp_endpoint *ep,
83 const struct sctp_association *asoc,
84 const sctp_subtype_t type,
85 void *arg,
86 sctp_cmd_seq_t *commands);
87static sctp_disposition_t sctp_sf_shut_8_4_5(const struct sctp_endpoint *ep,
88 const struct sctp_association *asoc,
89 const sctp_subtype_t type,
90 void *arg,
91 sctp_cmd_seq_t *commands);
Vlad Yasevichece25df2007-09-07 16:30:54 -040092static sctp_disposition_t sctp_sf_tabort_8_4_8(const struct sctp_endpoint *ep,
93 const struct sctp_association *asoc,
94 const sctp_subtype_t type,
95 void *arg,
96 sctp_cmd_seq_t *commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -070097static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk);
98
Adrian Bunk52c1da32005-06-23 22:05:33 -070099static sctp_disposition_t sctp_stop_t1_and_abort(sctp_cmd_seq_t *commands,
Al Virof94c0192006-11-20 17:00:25 -0800100 __be16 error, int sk_err,
Adrian Bunk52c1da32005-06-23 22:05:33 -0700101 const struct sctp_association *asoc,
102 struct sctp_transport *transport);
103
Wei Yongjunaecedea2007-08-02 16:57:44 +0800104static sctp_disposition_t sctp_sf_abort_violation(
Vlad Yasevichece25df2007-09-07 16:30:54 -0400105 const struct sctp_endpoint *ep,
Wei Yongjunaecedea2007-08-02 16:57:44 +0800106 const struct sctp_association *asoc,
107 void *arg,
108 sctp_cmd_seq_t *commands,
109 const __u8 *payload,
110 const size_t paylen);
111
Adrian Bunk52c1da32005-06-23 22:05:33 -0700112static sctp_disposition_t sctp_sf_violation_chunklen(
113 const struct sctp_endpoint *ep,
114 const struct sctp_association *asoc,
115 const sctp_subtype_t type,
116 void *arg,
117 sctp_cmd_seq_t *commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118
Wei Yongjun6f4c6182007-09-19 17:19:52 +0800119static sctp_disposition_t sctp_sf_violation_paramlen(
120 const struct sctp_endpoint *ep,
121 const struct sctp_association *asoc,
122 const sctp_subtype_t type,
Wei Yongjunba016672008-09-30 05:32:24 -0700123 void *arg, void *ext,
Wei Yongjun6f4c6182007-09-19 17:19:52 +0800124 sctp_cmd_seq_t *commands);
125
Wei Yongjunaecedea2007-08-02 16:57:44 +0800126static sctp_disposition_t sctp_sf_violation_ctsn(
127 const struct sctp_endpoint *ep,
128 const struct sctp_association *asoc,
129 const sctp_subtype_t type,
130 void *arg,
131 sctp_cmd_seq_t *commands);
132
Vlad Yasevichece25df2007-09-07 16:30:54 -0400133static sctp_disposition_t sctp_sf_violation_chunk(
134 const struct sctp_endpoint *ep,
135 const struct sctp_association *asoc,
136 const sctp_subtype_t type,
137 void *arg,
138 sctp_cmd_seq_t *commands);
139
Vlad Yasevichbbd0d592007-10-03 17:51:34 -0700140static sctp_ierror_t sctp_sf_authenticate(const struct sctp_endpoint *ep,
141 const struct sctp_association *asoc,
142 const sctp_subtype_t type,
143 struct sctp_chunk *chunk);
144
Vlad Yasevich75205f42007-12-20 14:12:59 -0800145static sctp_disposition_t __sctp_sf_do_9_1_abort(const struct sctp_endpoint *ep,
146 const struct sctp_association *asoc,
147 const sctp_subtype_t type,
148 void *arg,
149 sctp_cmd_seq_t *commands);
150
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151/* Small helper function that checks if the chunk length
152 * is of the appropriate length. The 'required_length' argument
153 * is set to be the size of a specific chunk we are testing.
154 * Return Values: 1 = Valid length
155 * 0 = Invalid length
156 *
157 */
158static inline int
159sctp_chunk_length_valid(struct sctp_chunk *chunk,
160 __u16 required_length)
161{
162 __u16 chunk_length = ntohs(chunk->chunk_hdr->length);
163
164 if (unlikely(chunk_length < required_length))
165 return 0;
166
167 return 1;
168}
169
170/**********************************************************
171 * These are the state functions for handling chunk events.
172 **********************************************************/
173
174/*
175 * Process the final SHUTDOWN COMPLETE.
176 *
177 * Section: 4 (C) (diagram), 9.2
178 * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify
179 * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be
180 * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint
181 * should stop the T2-shutdown timer and remove all knowledge of the
182 * association (and thus the association enters the CLOSED state).
183 *
Jerome Forissier047a2422005-04-28 11:58:43 -0700184 * Verification Tag: 8.5.1(C), sctpimpguide 2.41.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185 * C) Rules for packet carrying SHUTDOWN COMPLETE:
186 * ...
Jerome Forissier047a2422005-04-28 11:58:43 -0700187 * - The receiver of a SHUTDOWN COMPLETE shall accept the packet
188 * if the Verification Tag field of the packet matches its own tag and
189 * the T bit is not set
190 * OR
191 * it is set to its peer's tag and the T bit is set in the Chunk
192 * Flags.
193 * Otherwise, the receiver MUST silently discard the packet
194 * and take no further action. An endpoint MUST ignore the
195 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 *
197 * Inputs
198 * (endpoint, asoc, chunk)
199 *
200 * Outputs
201 * (asoc, reply_msg, msg_up, timers, counters)
202 *
203 * The return value is the disposition of the chunk.
204 */
205sctp_disposition_t sctp_sf_do_4_C(const struct sctp_endpoint *ep,
206 const struct sctp_association *asoc,
207 const sctp_subtype_t type,
208 void *arg,
209 sctp_cmd_seq_t *commands)
210{
211 struct sctp_chunk *chunk = arg;
212 struct sctp_ulpevent *ev;
213
Vlad Yasevichece25df2007-09-07 16:30:54 -0400214 if (!sctp_vtag_verify_either(chunk, asoc))
215 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
216
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217 /* RFC 2960 6.10 Bundling
218 *
219 * An endpoint MUST NOT bundle INIT, INIT ACK or
220 * SHUTDOWN COMPLETE with any other chunks.
221 */
222 if (!chunk->singleton)
Vlad Yasevichece25df2007-09-07 16:30:54 -0400223 return sctp_sf_violation_chunk(ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224
Vlad Yasevichece25df2007-09-07 16:30:54 -0400225 /* Make sure that the SHUTDOWN_COMPLETE chunk has a valid length. */
226 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
227 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
228 commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229
230 /* RFC 2960 10.2 SCTP-to-ULP
231 *
232 * H) SHUTDOWN COMPLETE notification
233 *
234 * When SCTP completes the shutdown procedures (section 9.2) this
235 * notification is passed to the upper layer.
236 */
237 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
Vlad Yasevicha5a35e72007-03-23 11:34:08 -0700238 0, 0, 0, NULL, GFP_ATOMIC);
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700239 if (ev)
240 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900241 SCTP_ULPEVENT(ev));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242
243 /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint
244 * will verify that it is in SHUTDOWN-ACK-SENT state, if it is
245 * not the chunk should be discarded. If the endpoint is in
246 * the SHUTDOWN-ACK-SENT state the endpoint should stop the
247 * T2-shutdown timer and remove all knowledge of the
248 * association (and thus the association enters the CLOSED
249 * state).
250 */
251 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
252 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
253
254 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
255 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
256
257 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
258 SCTP_STATE(SCTP_STATE_CLOSED));
259
260 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
261 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
262
263 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
264
265 return SCTP_DISPOSITION_DELETE_TCB;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266}
267
268/*
269 * Respond to a normal INIT chunk.
270 * We are the side that is being asked for an association.
271 *
272 * Section: 5.1 Normal Establishment of an Association, B
273 * B) "Z" shall respond immediately with an INIT ACK chunk. The
274 * destination IP address of the INIT ACK MUST be set to the source
275 * IP address of the INIT to which this INIT ACK is responding. In
276 * the response, besides filling in other parameters, "Z" must set the
277 * Verification Tag field to Tag_A, and also provide its own
278 * Verification Tag (Tag_Z) in the Initiate Tag field.
279 *
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900280 * Verification Tag: Must be 0.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281 *
282 * Inputs
283 * (endpoint, asoc, chunk)
284 *
285 * Outputs
286 * (asoc, reply_msg, msg_up, timers, counters)
287 *
288 * The return value is the disposition of the chunk.
289 */
290sctp_disposition_t sctp_sf_do_5_1B_init(const struct sctp_endpoint *ep,
291 const struct sctp_association *asoc,
292 const sctp_subtype_t type,
293 void *arg,
294 sctp_cmd_seq_t *commands)
295{
296 struct sctp_chunk *chunk = arg;
297 struct sctp_chunk *repl;
298 struct sctp_association *new_asoc;
299 struct sctp_chunk *err_chunk;
300 struct sctp_packet *packet;
301 sctp_unrecognized_param_t *unk_param;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302 int len;
303
304 /* 6.10 Bundling
305 * An endpoint MUST NOT bundle INIT, INIT ACK or
306 * SHUTDOWN COMPLETE with any other chunks.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900307 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308 * IG Section 2.11.2
309 * Furthermore, we require that the receiver of an INIT chunk MUST
310 * enforce these rules by silently discarding an arriving packet
311 * with an INIT chunk that is bundled with other chunks.
312 */
313 if (!chunk->singleton)
314 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
315
316 /* If the packet is an OOTB packet which is temporarily on the
317 * control endpoint, respond with an ABORT.
318 */
Wei Yongjun8190f892008-09-08 12:13:55 +0800319 if (ep == sctp_sk((sctp_get_ctl_sock()))->ep) {
320 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
Wei Yongjun8190f892008-09-08 12:13:55 +0800322 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900325 * Tag.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700326 */
327 if (chunk->sctp_hdr->vtag != 0)
328 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
329
330 /* Make sure that the INIT chunk has a valid length.
331 * Normally, this would cause an ABORT with a Protocol Violation
332 * error, but since we don't have an association, we'll
333 * just discard the packet.
334 */
335 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
336 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
337
Vlad Yasevichbec96402009-07-30 18:08:28 -0400338 /* If the INIT is coming toward a closing socket, we'll send back
339 * and ABORT. Essentially, this catches the race of INIT being
340 * backloged to the socket at the same time as the user isses close().
341 * Since the socket and all its associations are going away, we
342 * can treat this OOTB
343 */
344 if (sctp_sstate(ep->base.sk, CLOSING))
345 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
346
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347 /* Verify the INIT chunk before processing it. */
348 err_chunk = NULL;
349 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
350 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
351 &err_chunk)) {
352 /* This chunk contains fatal error. It is to be discarded.
353 * Send an ABORT, with causes if there is any.
354 */
355 if (err_chunk) {
356 packet = sctp_abort_pkt_new(ep, asoc, arg,
357 (__u8 *)(err_chunk->chunk_hdr) +
358 sizeof(sctp_chunkhdr_t),
359 ntohs(err_chunk->chunk_hdr->length) -
360 sizeof(sctp_chunkhdr_t));
361
362 sctp_chunk_free(err_chunk);
363
364 if (packet) {
365 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
366 SCTP_PACKET(packet));
367 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
368 return SCTP_DISPOSITION_CONSUME;
369 } else {
370 return SCTP_DISPOSITION_NOMEM;
371 }
372 } else {
373 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg,
374 commands);
375 }
376 }
377
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900378 /* Grab the INIT header. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379 chunk->subh.init_hdr = (sctp_inithdr_t *)chunk->skb->data;
380
381 /* Tag the variable length parameters. */
382 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
383
384 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
385 if (!new_asoc)
386 goto nomem;
387
Vlad Yasevich409b95a2009-11-10 08:57:34 +0000388 if (sctp_assoc_set_bind_addr_from_ep(new_asoc,
389 sctp_scope(sctp_source(chunk)),
390 GFP_ATOMIC) < 0)
391 goto nomem_init;
392
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393 /* The call, sctp_process_init(), can fail on memory allocation. */
394 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
395 sctp_source(chunk),
396 (sctp_init_chunk_t *)chunk->chunk_hdr,
397 GFP_ATOMIC))
398 goto nomem_init;
399
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
401
402 /* If there are errors need to be reported for unknown parameters,
403 * make sure to reserve enough room in the INIT ACK for them.
404 */
405 len = 0;
406 if (err_chunk)
407 len = ntohs(err_chunk->chunk_hdr->length) -
408 sizeof(sctp_chunkhdr_t);
409
Linus Torvalds1da177e2005-04-16 15:20:36 -0700410 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
411 if (!repl)
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700412 goto nomem_init;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700413
414 /* If there are errors need to be reported for unknown parameters,
415 * include them in the outgoing INIT ACK as "Unrecognized parameter"
416 * parameter.
417 */
418 if (err_chunk) {
419 /* Get the "Unrecognized parameter" parameter(s) out of the
420 * ERROR chunk generated by sctp_verify_init(). Since the
421 * error cause code for "unknown parameter" and the
422 * "Unrecognized parameter" type is the same, we can
423 * construct the parameters in INIT ACK by copying the
424 * ERROR causes over.
425 */
426 unk_param = (sctp_unrecognized_param_t *)
427 ((__u8 *)(err_chunk->chunk_hdr) +
428 sizeof(sctp_chunkhdr_t));
429 /* Replace the cause code with the "Unrecognized parameter"
430 * parameter type.
431 */
432 sctp_addto_chunk(repl, len, unk_param);
433 sctp_chunk_free(err_chunk);
434 }
435
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700436 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
437
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
439
440 /*
441 * Note: After sending out INIT ACK with the State Cookie parameter,
442 * "Z" MUST NOT allocate any resources, nor keep any states for the
443 * new association. Otherwise, "Z" will be vulnerable to resource
444 * attacks.
445 */
446 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
447
448 return SCTP_DISPOSITION_DELETE_TCB;
449
Linus Torvalds1da177e2005-04-16 15:20:36 -0700450nomem_init:
451 sctp_association_free(new_asoc);
452nomem:
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700453 if (err_chunk)
454 sctp_chunk_free(err_chunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455 return SCTP_DISPOSITION_NOMEM;
456}
457
458/*
459 * Respond to a normal INIT ACK chunk.
460 * We are the side that is initiating the association.
461 *
462 * Section: 5.1 Normal Establishment of an Association, C
463 * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init
464 * timer and leave COOKIE-WAIT state. "A" shall then send the State
465 * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start
466 * the T1-cookie timer, and enter the COOKIE-ECHOED state.
467 *
468 * Note: The COOKIE ECHO chunk can be bundled with any pending outbound
469 * DATA chunks, but it MUST be the first chunk in the packet and
470 * until the COOKIE ACK is returned the sender MUST NOT send any
471 * other packets to the peer.
472 *
473 * Verification Tag: 3.3.3
474 * If the value of the Initiate Tag in a received INIT ACK chunk is
475 * found to be 0, the receiver MUST treat it as an error and close the
476 * association by transmitting an ABORT.
477 *
478 * Inputs
479 * (endpoint, asoc, chunk)
480 *
481 * Outputs
482 * (asoc, reply_msg, msg_up, timers, counters)
483 *
484 * The return value is the disposition of the chunk.
485 */
486sctp_disposition_t sctp_sf_do_5_1C_ack(const struct sctp_endpoint *ep,
487 const struct sctp_association *asoc,
488 const sctp_subtype_t type,
489 void *arg,
490 sctp_cmd_seq_t *commands)
491{
492 struct sctp_chunk *chunk = arg;
493 sctp_init_chunk_t *initchunk;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494 struct sctp_chunk *err_chunk;
495 struct sctp_packet *packet;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700496
497 if (!sctp_vtag_verify(chunk, asoc))
498 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
499
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500 /* 6.10 Bundling
501 * An endpoint MUST NOT bundle INIT, INIT ACK or
502 * SHUTDOWN COMPLETE with any other chunks.
503 */
504 if (!chunk->singleton)
Vlad Yasevichece25df2007-09-07 16:30:54 -0400505 return sctp_sf_violation_chunk(ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506
Vlad Yasevichece25df2007-09-07 16:30:54 -0400507 /* Make sure that the INIT-ACK chunk has a valid length */
508 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_initack_chunk_t)))
509 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
510 commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700511 /* Grab the INIT header. */
512 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
513
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514 /* Verify the INIT chunk before processing it. */
515 err_chunk = NULL;
516 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
517 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
518 &err_chunk)) {
519
Vlad Yasevich853f4b52008-01-20 06:10:46 -0800520 sctp_error_t error = SCTP_ERROR_NO_RESOURCE;
521
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522 /* This chunk contains fatal error. It is to be discarded.
Vlad Yasevichd6701192007-12-20 14:13:31 -0800523 * Send an ABORT, with causes. If there are no causes,
524 * then there wasn't enough memory. Just terminate
525 * the association.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526 */
527 if (err_chunk) {
528 packet = sctp_abort_pkt_new(ep, asoc, arg,
529 (__u8 *)(err_chunk->chunk_hdr) +
530 sizeof(sctp_chunkhdr_t),
531 ntohs(err_chunk->chunk_hdr->length) -
532 sizeof(sctp_chunkhdr_t));
533
534 sctp_chunk_free(err_chunk);
535
536 if (packet) {
537 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
538 SCTP_PACKET(packet));
539 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700540 error = SCTP_ERROR_INV_PARAM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700541 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542 }
Vlad Yasevichbbd0d592007-10-03 17:51:34 -0700543
544 /* SCTP-AUTH, Section 6.3:
545 * It should be noted that if the receiver wants to tear
546 * down an association in an authenticated way only, the
547 * handling of malformed packets should not result in
548 * tearing down the association.
549 *
550 * This means that if we only want to abort associations
551 * in an authenticated way (i.e AUTH+ABORT), then we
Oliver Pinterac461a02008-02-03 17:52:41 +0200552 * can't destroy this association just becuase the packet
Vlad Yasevichbbd0d592007-10-03 17:51:34 -0700553 * was malformed.
554 */
555 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
556 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
557
558 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700559 return sctp_stop_t1_and_abort(commands, error, ECONNREFUSED,
560 asoc, chunk->transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561 }
562
563 /* Tag the variable length parameters. Note that we never
564 * convert the parameters in an INIT chunk.
565 */
566 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
567
568 initchunk = (sctp_init_chunk_t *) chunk->chunk_hdr;
569
570 sctp_add_cmd_sf(commands, SCTP_CMD_PEER_INIT,
571 SCTP_PEER_INIT(initchunk));
572
Frank Filz3f7a87d2005-06-20 13:14:57 -0700573 /* Reset init error count upon receipt of INIT-ACK. */
574 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
575
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576 /* 5.1 C) "A" shall stop the T1-init timer and leave
577 * COOKIE-WAIT state. "A" shall then ... start the T1-cookie
578 * timer, and enter the COOKIE-ECHOED state.
579 */
580 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
581 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
582 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
583 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
584 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
585 SCTP_STATE(SCTP_STATE_COOKIE_ECHOED));
586
Vlad Yasevich730fc3d2007-09-16 19:32:11 -0700587 /* SCTP-AUTH: genereate the assocition shared keys so that
588 * we can potentially signe the COOKIE-ECHO.
589 */
590 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_SHKEY, SCTP_NULL());
591
Linus Torvalds1da177e2005-04-16 15:20:36 -0700592 /* 5.1 C) "A" shall then send the State Cookie received in the
593 * INIT ACK chunk in a COOKIE ECHO chunk, ...
594 */
595 /* If there is any errors to report, send the ERROR chunk generated
596 * for unknown parameters as well.
597 */
598 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_COOKIE_ECHO,
599 SCTP_CHUNK(err_chunk));
600
601 return SCTP_DISPOSITION_CONSUME;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602}
603
604/*
605 * Respond to a normal COOKIE ECHO chunk.
606 * We are the side that is being asked for an association.
607 *
608 * Section: 5.1 Normal Establishment of an Association, D
609 * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply
610 * with a COOKIE ACK chunk after building a TCB and moving to
611 * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with
612 * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK
613 * chunk MUST be the first chunk in the packet.
614 *
615 * IMPLEMENTATION NOTE: An implementation may choose to send the
616 * Communication Up notification to the SCTP user upon reception
617 * of a valid COOKIE ECHO chunk.
618 *
619 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
620 * D) Rules for packet carrying a COOKIE ECHO
621 *
622 * - When sending a COOKIE ECHO, the endpoint MUST use the value of the
623 * Initial Tag received in the INIT ACK.
624 *
625 * - The receiver of a COOKIE ECHO follows the procedures in Section 5.
626 *
627 * Inputs
628 * (endpoint, asoc, chunk)
629 *
630 * Outputs
631 * (asoc, reply_msg, msg_up, timers, counters)
632 *
633 * The return value is the disposition of the chunk.
634 */
635sctp_disposition_t sctp_sf_do_5_1D_ce(const struct sctp_endpoint *ep,
636 const struct sctp_association *asoc,
637 const sctp_subtype_t type, void *arg,
638 sctp_cmd_seq_t *commands)
639{
640 struct sctp_chunk *chunk = arg;
641 struct sctp_association *new_asoc;
642 sctp_init_chunk_t *peer_init;
643 struct sctp_chunk *repl;
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700644 struct sctp_ulpevent *ev, *ai_ev = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700645 int error = 0;
646 struct sctp_chunk *err_chk_p;
Vlad Yasevich609ee462007-08-31 03:10:59 +0900647 struct sock *sk;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648
649 /* If the packet is an OOTB packet which is temporarily on the
650 * control endpoint, respond with an ABORT.
651 */
Wei Yongjun8190f892008-09-08 12:13:55 +0800652 if (ep == sctp_sk((sctp_get_ctl_sock()))->ep) {
653 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES);
Vlad Yasevichece25df2007-09-07 16:30:54 -0400654 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
Wei Yongjun8190f892008-09-08 12:13:55 +0800655 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700656
657 /* Make sure that the COOKIE_ECHO chunk has a valid length.
658 * In this case, we check that we have enough for at least a
659 * chunk header. More detailed verification is done
660 * in sctp_unpack_cookie().
661 */
662 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
663 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
664
Vlad Yasevich609ee462007-08-31 03:10:59 +0900665 /* If the endpoint is not listening or if the number of associations
666 * on the TCP-style socket exceed the max backlog, respond with an
667 * ABORT.
668 */
669 sk = ep->base.sk;
670 if (!sctp_sstate(sk, LISTENING) ||
671 (sctp_style(sk, TCP) && sk_acceptq_is_full(sk)))
672 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
673
Linus Torvalds1da177e2005-04-16 15:20:36 -0700674 /* "Decode" the chunk. We have no optional parameters so we
675 * are in good shape.
676 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900677 chunk->subh.cookie_hdr =
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678 (struct sctp_signed_cookie *)chunk->skb->data;
Sridhar Samudrala62b08082006-05-05 17:04:43 -0700679 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
680 sizeof(sctp_chunkhdr_t)))
681 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700682
683 /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
684 * "Z" will reply with a COOKIE ACK chunk after building a TCB
685 * and moving to the ESTABLISHED state.
686 */
687 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
688 &err_chk_p);
689
690 /* FIXME:
691 * If the re-build failed, what is the proper error path
692 * from here?
693 *
694 * [We should abort the association. --piggy]
695 */
696 if (!new_asoc) {
697 /* FIXME: Several errors are possible. A bad cookie should
698 * be silently discarded, but think about logging it too.
699 */
700 switch (error) {
701 case -SCTP_IERROR_NOMEM:
702 goto nomem;
703
704 case -SCTP_IERROR_STALE_COOKIE:
705 sctp_send_stale_cookie_err(ep, asoc, chunk, commands,
706 err_chk_p);
707 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
708
709 case -SCTP_IERROR_BAD_SIG:
710 default:
711 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700712 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713 }
714
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700716 /* Delay state machine commands until later.
717 *
718 * Re-build the bind address for the association is done in
Linus Torvalds1da177e2005-04-16 15:20:36 -0700719 * the sctp_unpack_cookie() already.
720 */
721 /* This is a brand-new association, so these are not yet side
722 * effects--it is safe to run them here.
723 */
724 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
725
726 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
Al Viro6a1e5f32006-11-20 17:12:25 -0800727 &chunk->subh.cookie_hdr->c.peer_addr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728 peer_init, GFP_ATOMIC))
729 goto nomem_init;
730
Vlad Yasevich730fc3d2007-09-16 19:32:11 -0700731 /* SCTP-AUTH: Now that we've populate required fields in
732 * sctp_process_init, set up the assocaition shared keys as
733 * necessary so that we can potentially authenticate the ACK
734 */
735 error = sctp_auth_asoc_init_active_key(new_asoc, GFP_ATOMIC);
736 if (error)
737 goto nomem_init;
738
Vlad Yasevichbbd0d592007-10-03 17:51:34 -0700739 /* SCTP-AUTH: auth_chunk pointer is only set when the cookie-echo
740 * is supposed to be authenticated and we have to do delayed
741 * authentication. We've just recreated the association using
742 * the information in the cookie and now it's much easier to
743 * do the authentication.
744 */
745 if (chunk->auth_chunk) {
746 struct sctp_chunk auth;
747 sctp_ierror_t ret;
748
749 /* set-up our fake chunk so that we can process it */
750 auth.skb = chunk->auth_chunk;
751 auth.asoc = chunk->asoc;
752 auth.sctp_hdr = chunk->sctp_hdr;
753 auth.chunk_hdr = (sctp_chunkhdr_t *)skb_push(chunk->auth_chunk,
754 sizeof(sctp_chunkhdr_t));
755 skb_pull(chunk->auth_chunk, sizeof(sctp_chunkhdr_t));
756 auth.transport = chunk->transport;
757
758 ret = sctp_sf_authenticate(ep, new_asoc, type, &auth);
759
760 /* We can now safely free the auth_chunk clone */
761 kfree_skb(chunk->auth_chunk);
762
763 if (ret != SCTP_IERROR_NO_ERROR) {
764 sctp_association_free(new_asoc);
765 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
766 }
767 }
768
Linus Torvalds1da177e2005-04-16 15:20:36 -0700769 repl = sctp_make_cookie_ack(new_asoc, chunk);
770 if (!repl)
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700771 goto nomem_init;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700772
773 /* RFC 2960 5.1 Normal Establishment of an Association
774 *
775 * D) IMPLEMENTATION NOTE: An implementation may choose to
776 * send the Communication Up notification to the SCTP user
777 * upon reception of a valid COOKIE ECHO chunk.
778 */
779 ev = sctp_ulpevent_make_assoc_change(new_asoc, 0, SCTP_COMM_UP, 0,
780 new_asoc->c.sinit_num_ostreams,
781 new_asoc->c.sinit_max_instreams,
Vlad Yasevicha5a35e72007-03-23 11:34:08 -0700782 NULL, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700783 if (!ev)
784 goto nomem_ev;
785
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900786 /* Sockets API Draft Section 5.3.1.6
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -0800787 * When a peer sends a Adaptation Layer Indication parameter , SCTP
Linus Torvalds1da177e2005-04-16 15:20:36 -0700788 * delivers this notification to inform the application that of the
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -0800789 * peers requested adaptation layer.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790 */
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -0800791 if (new_asoc->peer.adaptation_ind) {
792 ai_ev = sctp_ulpevent_make_adaptation_indication(new_asoc,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700793 GFP_ATOMIC);
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700794 if (!ai_ev)
795 goto nomem_aiev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700796 }
797
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700798 /* Add all the state machine commands now since we've created
799 * everything. This way we don't introduce memory corruptions
800 * during side-effect processing and correclty count established
801 * associations.
802 */
803 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
804 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
805 SCTP_STATE(SCTP_STATE_ESTABLISHED));
806 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
807 SCTP_INC_STATS(SCTP_MIB_PASSIVEESTABS);
808 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
809
810 if (new_asoc->autoclose)
811 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
812 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
813
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700814 /* This will send the COOKIE ACK */
815 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
816
817 /* Queue the ASSOC_CHANGE event */
818 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
819
820 /* Send up the Adaptation Layer Indication event */
821 if (ai_ev)
822 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
823 SCTP_ULPEVENT(ai_ev));
824
Linus Torvalds1da177e2005-04-16 15:20:36 -0700825 return SCTP_DISPOSITION_CONSUME;
826
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700827nomem_aiev:
828 sctp_ulpevent_free(ev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700829nomem_ev:
830 sctp_chunk_free(repl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700831nomem_init:
832 sctp_association_free(new_asoc);
833nomem:
834 return SCTP_DISPOSITION_NOMEM;
835}
836
837/*
838 * Respond to a normal COOKIE ACK chunk.
839 * We are the side that is being asked for an association.
840 *
841 * RFC 2960 5.1 Normal Establishment of an Association
842 *
843 * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the
844 * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie
845 * timer. It may also notify its ULP about the successful
846 * establishment of the association with a Communication Up
847 * notification (see Section 10).
848 *
849 * Verification Tag:
850 * Inputs
851 * (endpoint, asoc, chunk)
852 *
853 * Outputs
854 * (asoc, reply_msg, msg_up, timers, counters)
855 *
856 * The return value is the disposition of the chunk.
857 */
858sctp_disposition_t sctp_sf_do_5_1E_ca(const struct sctp_endpoint *ep,
859 const struct sctp_association *asoc,
860 const sctp_subtype_t type, void *arg,
861 sctp_cmd_seq_t *commands)
862{
863 struct sctp_chunk *chunk = arg;
864 struct sctp_ulpevent *ev;
865
866 if (!sctp_vtag_verify(chunk, asoc))
867 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
868
869 /* Verify that the chunk length for the COOKIE-ACK is OK.
870 * If we don't do this, any bundled chunks may be junked.
871 */
872 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
873 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
874 commands);
875
876 /* Reset init error count upon receipt of COOKIE-ACK,
877 * to avoid problems with the managemement of this
878 * counter in stale cookie situations when a transition back
879 * from the COOKIE-ECHOED state to the COOKIE-WAIT
880 * state is performed.
881 */
Frank Filz3f7a87d2005-06-20 13:14:57 -0700882 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883
884 /* RFC 2960 5.1 Normal Establishment of an Association
885 *
886 * E) Upon reception of the COOKIE ACK, endpoint "A" will move
887 * from the COOKIE-ECHOED state to the ESTABLISHED state,
888 * stopping the T1-cookie timer.
889 */
890 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
891 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
892 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
893 SCTP_STATE(SCTP_STATE_ESTABLISHED));
894 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
895 SCTP_INC_STATS(SCTP_MIB_ACTIVEESTABS);
896 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
897 if (asoc->autoclose)
898 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
899 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700900
901 /* It may also notify its ULP about the successful
902 * establishment of the association with a Communication Up
903 * notification (see Section 10).
904 */
905 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP,
906 0, asoc->c.sinit_num_ostreams,
907 asoc->c.sinit_max_instreams,
Vlad Yasevicha5a35e72007-03-23 11:34:08 -0700908 NULL, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700909
910 if (!ev)
911 goto nomem;
912
913 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
914
915 /* Sockets API Draft Section 5.3.1.6
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -0800916 * When a peer sends a Adaptation Layer Indication parameter , SCTP
Linus Torvalds1da177e2005-04-16 15:20:36 -0700917 * delivers this notification to inform the application that of the
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -0800918 * peers requested adaptation layer.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700919 */
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -0800920 if (asoc->peer.adaptation_ind) {
921 ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700922 if (!ev)
923 goto nomem;
924
925 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
926 SCTP_ULPEVENT(ev));
927 }
928
929 return SCTP_DISPOSITION_CONSUME;
930nomem:
931 return SCTP_DISPOSITION_NOMEM;
932}
933
934/* Generate and sendout a heartbeat packet. */
935static sctp_disposition_t sctp_sf_heartbeat(const struct sctp_endpoint *ep,
936 const struct sctp_association *asoc,
937 const sctp_subtype_t type,
938 void *arg,
939 sctp_cmd_seq_t *commands)
940{
941 struct sctp_transport *transport = (struct sctp_transport *) arg;
942 struct sctp_chunk *reply;
943 sctp_sender_hb_info_t hbinfo;
944 size_t paylen = 0;
945
946 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO;
947 hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t));
Al Viro63de08f2006-11-20 17:07:25 -0800948 hbinfo.daddr = transport->ipaddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700949 hbinfo.sent_at = jiffies;
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700950 hbinfo.hb_nonce = transport->hb_nonce;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700951
952 /* Send a heartbeat to our peer. */
953 paylen = sizeof(sctp_sender_hb_info_t);
954 reply = sctp_make_heartbeat(asoc, transport, &hbinfo, paylen);
955 if (!reply)
956 return SCTP_DISPOSITION_NOMEM;
957
958 /* Set rto_pending indicating that an RTT measurement
959 * is started with this heartbeat chunk.
960 */
961 sctp_add_cmd_sf(commands, SCTP_CMD_RTO_PENDING,
962 SCTP_TRANSPORT(transport));
963
964 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
965 return SCTP_DISPOSITION_CONSUME;
966}
967
968/* Generate a HEARTBEAT packet on the given transport. */
969sctp_disposition_t sctp_sf_sendbeat_8_3(const struct sctp_endpoint *ep,
970 const struct sctp_association *asoc,
971 const sctp_subtype_t type,
972 void *arg,
973 sctp_cmd_seq_t *commands)
974{
975 struct sctp_transport *transport = (struct sctp_transport *) arg;
976
Vlad Yasevichb9f84782009-08-26 09:36:25 -0400977 if (asoc->overall_error_count >= asoc->max_retrans) {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700978 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
979 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700980 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
981 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -0800982 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700983 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
984 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
985 return SCTP_DISPOSITION_DELETE_TCB;
986 }
987
988 /* Section 3.3.5.
989 * The Sender-specific Heartbeat Info field should normally include
990 * information about the sender's current time when this HEARTBEAT
991 * chunk is sent and the destination transport address to which this
992 * HEARTBEAT is sent (see Section 8.3).
993 */
994
Frank Filz52ccb8e2005-12-22 11:36:46 -0800995 if (transport->param_flags & SPP_HB_ENABLE) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700996 if (SCTP_DISPOSITION_NOMEM ==
997 sctp_sf_heartbeat(ep, asoc, type, arg,
998 commands))
999 return SCTP_DISPOSITION_NOMEM;
Vlad Yasevich245cba72009-11-23 15:53:58 -05001000
Linus Torvalds1da177e2005-04-16 15:20:36 -07001001 /* Set transport error counter and association error counter
1002 * when sending heartbeat.
1003 */
Vlad Yasevich7e990132009-03-02 09:46:14 +00001004 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_HB_SENT,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001005 SCTP_TRANSPORT(transport));
1006 }
Vlad Yasevich245cba72009-11-23 15:53:58 -05001007 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_IDLE,
1008 SCTP_TRANSPORT(transport));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001009 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMER_UPDATE,
1010 SCTP_TRANSPORT(transport));
1011
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001012 return SCTP_DISPOSITION_CONSUME;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001013}
1014
1015/*
1016 * Process an heartbeat request.
1017 *
1018 * Section: 8.3 Path Heartbeat
1019 * The receiver of the HEARTBEAT should immediately respond with a
1020 * HEARTBEAT ACK that contains the Heartbeat Information field copied
1021 * from the received HEARTBEAT chunk.
1022 *
1023 * Verification Tag: 8.5 Verification Tag [Normal verification]
1024 * When receiving an SCTP packet, the endpoint MUST ensure that the
1025 * value in the Verification Tag field of the received SCTP packet
1026 * matches its own Tag. If the received Verification Tag value does not
1027 * match the receiver's own tag value, the receiver shall silently
1028 * discard the packet and shall not process it any further except for
1029 * those cases listed in Section 8.5.1 below.
1030 *
1031 * Inputs
1032 * (endpoint, asoc, chunk)
1033 *
1034 * Outputs
1035 * (asoc, reply_msg, msg_up, timers, counters)
1036 *
1037 * The return value is the disposition of the chunk.
1038 */
1039sctp_disposition_t sctp_sf_beat_8_3(const struct sctp_endpoint *ep,
1040 const struct sctp_association *asoc,
1041 const sctp_subtype_t type,
1042 void *arg,
1043 sctp_cmd_seq_t *commands)
1044{
1045 struct sctp_chunk *chunk = arg;
1046 struct sctp_chunk *reply;
1047 size_t paylen = 0;
1048
1049 if (!sctp_vtag_verify(chunk, asoc))
1050 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1051
1052 /* Make sure that the HEARTBEAT chunk has a valid length. */
1053 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t)))
1054 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1055 commands);
1056
1057 /* 8.3 The receiver of the HEARTBEAT should immediately
1058 * respond with a HEARTBEAT ACK that contains the Heartbeat
1059 * Information field copied from the received HEARTBEAT chunk.
1060 */
1061 chunk->subh.hb_hdr = (sctp_heartbeathdr_t *) chunk->skb->data;
1062 paylen = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
Sridhar Samudrala62b08082006-05-05 17:04:43 -07001063 if (!pskb_pull(chunk->skb, paylen))
1064 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001065
1066 reply = sctp_make_heartbeat_ack(asoc, chunk,
1067 chunk->subh.hb_hdr, paylen);
1068 if (!reply)
1069 goto nomem;
1070
1071 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
1072 return SCTP_DISPOSITION_CONSUME;
1073
1074nomem:
1075 return SCTP_DISPOSITION_NOMEM;
1076}
1077
1078/*
1079 * Process the returning HEARTBEAT ACK.
1080 *
1081 * Section: 8.3 Path Heartbeat
1082 * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT
1083 * should clear the error counter of the destination transport
1084 * address to which the HEARTBEAT was sent, and mark the destination
1085 * transport address as active if it is not so marked. The endpoint may
1086 * optionally report to the upper layer when an inactive destination
1087 * address is marked as active due to the reception of the latest
1088 * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also
1089 * clear the association overall error count as well (as defined
1090 * in section 8.1).
1091 *
1092 * The receiver of the HEARTBEAT ACK should also perform an RTT
1093 * measurement for that destination transport address using the time
1094 * value carried in the HEARTBEAT ACK chunk.
1095 *
1096 * Verification Tag: 8.5 Verification Tag [Normal verification]
1097 *
1098 * Inputs
1099 * (endpoint, asoc, chunk)
1100 *
1101 * Outputs
1102 * (asoc, reply_msg, msg_up, timers, counters)
1103 *
1104 * The return value is the disposition of the chunk.
1105 */
1106sctp_disposition_t sctp_sf_backbeat_8_3(const struct sctp_endpoint *ep,
1107 const struct sctp_association *asoc,
1108 const sctp_subtype_t type,
1109 void *arg,
1110 sctp_cmd_seq_t *commands)
1111{
1112 struct sctp_chunk *chunk = arg;
1113 union sctp_addr from_addr;
1114 struct sctp_transport *link;
1115 sctp_sender_hb_info_t *hbinfo;
1116 unsigned long max_interval;
1117
1118 if (!sctp_vtag_verify(chunk, asoc))
1119 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1120
1121 /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */
Wei Yongjundadb50c2009-08-22 11:27:37 +08001122 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t) +
1123 sizeof(sctp_sender_hb_info_t)))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001124 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1125 commands);
1126
1127 hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
Vladislav Yasevicha6012662006-05-19 14:25:53 -07001128 /* Make sure that the length of the parameter is what we expect */
1129 if (ntohs(hbinfo->param_hdr.length) !=
1130 sizeof(sctp_sender_hb_info_t)) {
1131 return SCTP_DISPOSITION_DISCARD;
1132 }
1133
Linus Torvalds1da177e2005-04-16 15:20:36 -07001134 from_addr = hbinfo->daddr;
Al Viro63de08f2006-11-20 17:07:25 -08001135 link = sctp_assoc_lookup_paddr(asoc, &from_addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001136
1137 /* This should never happen, but lets log it if so. */
Frank Filz3f7a87d2005-06-20 13:14:57 -07001138 if (unlikely(!link)) {
1139 if (from_addr.sa.sa_family == AF_INET6) {
Wei Yongjund99fa422007-08-27 11:19:24 +08001140 if (net_ratelimit())
1141 printk(KERN_WARNING
Harvey Harrison5b095d9892008-10-29 12:52:50 -07001142 "%s association %p could not find address %pI6\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001143 __func__,
Wei Yongjund99fa422007-08-27 11:19:24 +08001144 asoc,
Harvey Harrisonfdb46ee2008-10-28 16:10:17 -07001145 &from_addr.v6.sin6_addr);
Frank Filz3f7a87d2005-06-20 13:14:57 -07001146 } else {
Wei Yongjund99fa422007-08-27 11:19:24 +08001147 if (net_ratelimit())
1148 printk(KERN_WARNING
Harvey Harrison21454aa2008-10-31 00:54:56 -07001149 "%s association %p could not find address %pI4\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001150 __func__,
Wei Yongjund99fa422007-08-27 11:19:24 +08001151 asoc,
Harvey Harrison21454aa2008-10-31 00:54:56 -07001152 &from_addr.v4.sin_addr.s_addr);
Frank Filz3f7a87d2005-06-20 13:14:57 -07001153 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001154 return SCTP_DISPOSITION_DISCARD;
1155 }
1156
Sridhar Samudralaad8fec12006-07-21 14:48:50 -07001157 /* Validate the 64-bit random nonce. */
1158 if (hbinfo->hb_nonce != link->hb_nonce)
1159 return SCTP_DISPOSITION_DISCARD;
1160
Frank Filz52ccb8e2005-12-22 11:36:46 -08001161 max_interval = link->hbinterval + link->rto;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001162
1163 /* Check if the timestamp looks valid. */
1164 if (time_after(hbinfo->sent_at, jiffies) ||
1165 time_after(jiffies, hbinfo->sent_at + max_interval)) {
Joe Perches9ee46f12007-11-19 23:47:47 -08001166 SCTP_DEBUG_PRINTK("%s: HEARTBEAT ACK with invalid timestamp "
Linus Torvalds1da177e2005-04-16 15:20:36 -07001167 "received for transport: %p\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001168 __func__, link);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001169 return SCTP_DISPOSITION_DISCARD;
1170 }
1171
1172 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of
1173 * the HEARTBEAT should clear the error counter of the
1174 * destination transport address to which the HEARTBEAT was
1175 * sent and mark the destination transport address as active if
1176 * it is not so marked.
1177 */
1178 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_ON, SCTP_TRANSPORT(link));
1179
1180 return SCTP_DISPOSITION_CONSUME;
1181}
1182
1183/* Helper function to send out an abort for the restart
1184 * condition.
1185 */
1186static int sctp_sf_send_restart_abort(union sctp_addr *ssa,
1187 struct sctp_chunk *init,
1188 sctp_cmd_seq_t *commands)
1189{
1190 int len;
1191 struct sctp_packet *pkt;
1192 union sctp_addr_param *addrparm;
1193 struct sctp_errhdr *errhdr;
1194 struct sctp_endpoint *ep;
1195 char buffer[sizeof(struct sctp_errhdr)+sizeof(union sctp_addr_param)];
1196 struct sctp_af *af = sctp_get_af_specific(ssa->v4.sin_family);
1197
1198 /* Build the error on the stack. We are way to malloc crazy
1199 * throughout the code today.
1200 */
1201 errhdr = (struct sctp_errhdr *)buffer;
1202 addrparm = (union sctp_addr_param *)errhdr->variable;
1203
1204 /* Copy into a parm format. */
1205 len = af->to_addr_param(ssa, addrparm);
1206 len += sizeof(sctp_errhdr_t);
1207
1208 errhdr->cause = SCTP_ERROR_RESTART;
1209 errhdr->length = htons(len);
1210
1211 /* Assign to the control socket. */
1212 ep = sctp_sk((sctp_get_ctl_sock()))->ep;
1213
1214 /* Association is NULL since this may be a restart attack and we
1215 * want to send back the attacker's vtag.
1216 */
1217 pkt = sctp_abort_pkt_new(ep, NULL, init, errhdr, len);
1218
1219 if (!pkt)
1220 goto out;
1221 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, SCTP_PACKET(pkt));
1222
1223 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
1224
1225 /* Discard the rest of the inbound packet. */
1226 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
1227
1228out:
1229 /* Even if there is no memory, treat as a failure so
1230 * the packet will get dropped.
1231 */
1232 return 0;
1233}
1234
1235/* A restart is occurring, check to make sure no new addresses
1236 * are being added as we may be under a takeover attack.
1237 */
1238static int sctp_sf_check_restart_addrs(const struct sctp_association *new_asoc,
1239 const struct sctp_association *asoc,
1240 struct sctp_chunk *init,
1241 sctp_cmd_seq_t *commands)
1242{
1243 struct sctp_transport *new_addr, *addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001244 int found;
1245
1246 /* Implementor's Guide - Sectin 5.2.2
1247 * ...
1248 * Before responding the endpoint MUST check to see if the
1249 * unexpected INIT adds new addresses to the association. If new
1250 * addresses are added to the association, the endpoint MUST respond
1251 * with an ABORT..
1252 */
1253
1254 /* Search through all current addresses and make sure
1255 * we aren't adding any new ones.
1256 */
1257 new_addr = NULL;
1258 found = 0;
1259
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -07001260 list_for_each_entry(new_addr, &new_asoc->peer.transport_addr_list,
1261 transports) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001262 found = 0;
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -07001263 list_for_each_entry(addr, &asoc->peer.transport_addr_list,
1264 transports) {
Al Viro5f242a12006-11-20 17:05:23 -08001265 if (sctp_cmp_addr_exact(&new_addr->ipaddr,
1266 &addr->ipaddr)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001267 found = 1;
1268 break;
1269 }
1270 }
1271 if (!found)
1272 break;
1273 }
1274
1275 /* If a new address was added, ABORT the sender. */
1276 if (!found && new_addr) {
Al Viro7dd8a582006-11-20 17:23:25 -08001277 sctp_sf_send_restart_abort(&new_addr->ipaddr, init, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001278 }
1279
1280 /* Return success if all addresses were found. */
1281 return found;
1282}
1283
1284/* Populate the verification/tie tags based on overlapping INIT
1285 * scenario.
1286 *
1287 * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state.
1288 */
1289static void sctp_tietags_populate(struct sctp_association *new_asoc,
1290 const struct sctp_association *asoc)
1291{
1292 switch (asoc->state) {
1293
1294 /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */
1295
1296 case SCTP_STATE_COOKIE_WAIT:
1297 new_asoc->c.my_vtag = asoc->c.my_vtag;
1298 new_asoc->c.my_ttag = asoc->c.my_vtag;
1299 new_asoc->c.peer_ttag = 0;
1300 break;
1301
1302 case SCTP_STATE_COOKIE_ECHOED:
1303 new_asoc->c.my_vtag = asoc->c.my_vtag;
1304 new_asoc->c.my_ttag = asoc->c.my_vtag;
1305 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1306 break;
1307
1308 /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED,
1309 * COOKIE-WAIT and SHUTDOWN-ACK-SENT
1310 */
1311 default:
1312 new_asoc->c.my_ttag = asoc->c.my_vtag;
1313 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1314 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07001315 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001316
1317 /* Other parameters for the endpoint SHOULD be copied from the
1318 * existing parameters of the association (e.g. number of
1319 * outbound streams) into the INIT ACK and cookie.
1320 */
1321 new_asoc->rwnd = asoc->rwnd;
1322 new_asoc->c.sinit_num_ostreams = asoc->c.sinit_num_ostreams;
1323 new_asoc->c.sinit_max_instreams = asoc->c.sinit_max_instreams;
1324 new_asoc->c.initial_tsn = asoc->c.initial_tsn;
1325}
1326
1327/*
1328 * Compare vtag/tietag values to determine unexpected COOKIE-ECHO
1329 * handling action.
1330 *
1331 * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists.
1332 *
1333 * Returns value representing action to be taken. These action values
1334 * correspond to Action/Description values in RFC 2960, Table 2.
1335 */
1336static char sctp_tietags_compare(struct sctp_association *new_asoc,
1337 const struct sctp_association *asoc)
1338{
1339 /* In this case, the peer may have restarted. */
1340 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1341 (asoc->c.peer_vtag != new_asoc->c.peer_vtag) &&
1342 (asoc->c.my_vtag == new_asoc->c.my_ttag) &&
1343 (asoc->c.peer_vtag == new_asoc->c.peer_ttag))
1344 return 'A';
1345
1346 /* Collision case B. */
1347 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1348 ((asoc->c.peer_vtag != new_asoc->c.peer_vtag) ||
1349 (0 == asoc->c.peer_vtag))) {
1350 return 'B';
1351 }
1352
1353 /* Collision case D. */
1354 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1355 (asoc->c.peer_vtag == new_asoc->c.peer_vtag))
1356 return 'D';
1357
1358 /* Collision case C. */
1359 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1360 (asoc->c.peer_vtag == new_asoc->c.peer_vtag) &&
1361 (0 == new_asoc->c.my_ttag) &&
1362 (0 == new_asoc->c.peer_ttag))
1363 return 'C';
1364
1365 /* No match to any of the special cases; discard this packet. */
1366 return 'E';
1367}
1368
1369/* Common helper routine for both duplicate and simulataneous INIT
1370 * chunk handling.
1371 */
1372static sctp_disposition_t sctp_sf_do_unexpected_init(
1373 const struct sctp_endpoint *ep,
1374 const struct sctp_association *asoc,
1375 const sctp_subtype_t type,
1376 void *arg, sctp_cmd_seq_t *commands)
1377{
1378 sctp_disposition_t retval;
1379 struct sctp_chunk *chunk = arg;
1380 struct sctp_chunk *repl;
1381 struct sctp_association *new_asoc;
1382 struct sctp_chunk *err_chunk;
1383 struct sctp_packet *packet;
1384 sctp_unrecognized_param_t *unk_param;
1385 int len;
1386
1387 /* 6.10 Bundling
1388 * An endpoint MUST NOT bundle INIT, INIT ACK or
1389 * SHUTDOWN COMPLETE with any other chunks.
1390 *
1391 * IG Section 2.11.2
1392 * Furthermore, we require that the receiver of an INIT chunk MUST
1393 * enforce these rules by silently discarding an arriving packet
1394 * with an INIT chunk that is bundled with other chunks.
1395 */
1396 if (!chunk->singleton)
1397 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1398
1399 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001400 * Tag.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001401 */
1402 if (chunk->sctp_hdr->vtag != 0)
1403 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
1404
1405 /* Make sure that the INIT chunk has a valid length.
1406 * In this case, we generate a protocol violation since we have
1407 * an association established.
1408 */
1409 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
1410 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1411 commands);
1412 /* Grab the INIT header. */
1413 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
1414
1415 /* Tag the variable length parameters. */
1416 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
1417
1418 /* Verify the INIT chunk before processing it. */
1419 err_chunk = NULL;
1420 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
1421 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
1422 &err_chunk)) {
1423 /* This chunk contains fatal error. It is to be discarded.
1424 * Send an ABORT, with causes if there is any.
1425 */
1426 if (err_chunk) {
1427 packet = sctp_abort_pkt_new(ep, asoc, arg,
1428 (__u8 *)(err_chunk->chunk_hdr) +
1429 sizeof(sctp_chunkhdr_t),
1430 ntohs(err_chunk->chunk_hdr->length) -
1431 sizeof(sctp_chunkhdr_t));
1432
1433 if (packet) {
1434 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
1435 SCTP_PACKET(packet));
1436 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
1437 retval = SCTP_DISPOSITION_CONSUME;
1438 } else {
1439 retval = SCTP_DISPOSITION_NOMEM;
1440 }
1441 goto cleanup;
1442 } else {
1443 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg,
1444 commands);
1445 }
1446 }
1447
1448 /*
1449 * Other parameters for the endpoint SHOULD be copied from the
1450 * existing parameters of the association (e.g. number of
1451 * outbound streams) into the INIT ACK and cookie.
1452 * FIXME: We are copying parameters from the endpoint not the
1453 * association.
1454 */
1455 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
1456 if (!new_asoc)
1457 goto nomem;
1458
Vlad Yasevich409b95a2009-11-10 08:57:34 +00001459 if (sctp_assoc_set_bind_addr_from_ep(new_asoc,
1460 sctp_scope(sctp_source(chunk)), GFP_ATOMIC) < 0)
1461 goto nomem;
1462
Linus Torvalds1da177e2005-04-16 15:20:36 -07001463 /* In the outbound INIT ACK the endpoint MUST copy its current
1464 * Verification Tag and Peers Verification tag into a reserved
1465 * place (local tie-tag and per tie-tag) within the state cookie.
1466 */
1467 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
1468 sctp_source(chunk),
1469 (sctp_init_chunk_t *)chunk->chunk_hdr,
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001470 GFP_ATOMIC))
1471 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001472
1473 /* Make sure no new addresses are being added during the
1474 * restart. Do not do this check for COOKIE-WAIT state,
1475 * since there are no peer addresses to check against.
1476 * Upon return an ABORT will have been sent if needed.
1477 */
1478 if (!sctp_state(asoc, COOKIE_WAIT)) {
1479 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk,
1480 commands)) {
1481 retval = SCTP_DISPOSITION_CONSUME;
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001482 goto nomem_retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001483 }
1484 }
1485
1486 sctp_tietags_populate(new_asoc, asoc);
1487
1488 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
1489
1490 /* If there are errors need to be reported for unknown parameters,
1491 * make sure to reserve enough room in the INIT ACK for them.
1492 */
1493 len = 0;
1494 if (err_chunk) {
1495 len = ntohs(err_chunk->chunk_hdr->length) -
1496 sizeof(sctp_chunkhdr_t);
1497 }
1498
Linus Torvalds1da177e2005-04-16 15:20:36 -07001499 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
1500 if (!repl)
1501 goto nomem;
1502
1503 /* If there are errors need to be reported for unknown parameters,
1504 * include them in the outgoing INIT ACK as "Unrecognized parameter"
1505 * parameter.
1506 */
1507 if (err_chunk) {
1508 /* Get the "Unrecognized parameter" parameter(s) out of the
1509 * ERROR chunk generated by sctp_verify_init(). Since the
1510 * error cause code for "unknown parameter" and the
1511 * "Unrecognized parameter" type is the same, we can
1512 * construct the parameters in INIT ACK by copying the
1513 * ERROR causes over.
1514 */
1515 unk_param = (sctp_unrecognized_param_t *)
1516 ((__u8 *)(err_chunk->chunk_hdr) +
1517 sizeof(sctp_chunkhdr_t));
1518 /* Replace the cause code with the "Unrecognized parameter"
1519 * parameter type.
1520 */
1521 sctp_addto_chunk(repl, len, unk_param);
1522 }
1523
1524 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
1525 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1526
1527 /*
1528 * Note: After sending out INIT ACK with the State Cookie parameter,
1529 * "Z" MUST NOT allocate any resources for this new association.
1530 * Otherwise, "Z" will be vulnerable to resource attacks.
1531 */
1532 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
1533 retval = SCTP_DISPOSITION_CONSUME;
1534
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001535 return retval;
1536
1537nomem:
1538 retval = SCTP_DISPOSITION_NOMEM;
1539nomem_retval:
1540 if (new_asoc)
1541 sctp_association_free(new_asoc);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001542cleanup:
1543 if (err_chunk)
1544 sctp_chunk_free(err_chunk);
1545 return retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001546}
1547
1548/*
1549 * Handle simultanous INIT.
1550 * This means we started an INIT and then we got an INIT request from
1551 * our peer.
1552 *
1553 * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B)
1554 * This usually indicates an initialization collision, i.e., each
1555 * endpoint is attempting, at about the same time, to establish an
1556 * association with the other endpoint.
1557 *
1558 * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an
1559 * endpoint MUST respond with an INIT ACK using the same parameters it
1560 * sent in its original INIT chunk (including its Verification Tag,
1561 * unchanged). These original parameters are combined with those from the
1562 * newly received INIT chunk. The endpoint shall also generate a State
1563 * Cookie with the INIT ACK. The endpoint uses the parameters sent in its
1564 * INIT to calculate the State Cookie.
1565 *
1566 * After that, the endpoint MUST NOT change its state, the T1-init
1567 * timer shall be left running and the corresponding TCB MUST NOT be
1568 * destroyed. The normal procedures for handling State Cookies when
1569 * a TCB exists will resolve the duplicate INITs to a single association.
1570 *
1571 * For an endpoint that is in the COOKIE-ECHOED state it MUST populate
1572 * its Tie-Tags with the Tag information of itself and its peer (see
1573 * section 5.2.2 for a description of the Tie-Tags).
1574 *
1575 * Verification Tag: Not explicit, but an INIT can not have a valid
1576 * verification tag, so we skip the check.
1577 *
1578 * Inputs
1579 * (endpoint, asoc, chunk)
1580 *
1581 * Outputs
1582 * (asoc, reply_msg, msg_up, timers, counters)
1583 *
1584 * The return value is the disposition of the chunk.
1585 */
1586sctp_disposition_t sctp_sf_do_5_2_1_siminit(const struct sctp_endpoint *ep,
1587 const struct sctp_association *asoc,
1588 const sctp_subtype_t type,
1589 void *arg,
1590 sctp_cmd_seq_t *commands)
1591{
1592 /* Call helper to do the real work for both simulataneous and
1593 * duplicate INIT chunk handling.
1594 */
1595 return sctp_sf_do_unexpected_init(ep, asoc, type, arg, commands);
1596}
1597
1598/*
1599 * Handle duplicated INIT messages. These are usually delayed
1600 * restransmissions.
1601 *
1602 * Section: 5.2.2 Unexpected INIT in States Other than CLOSED,
1603 * COOKIE-ECHOED and COOKIE-WAIT
1604 *
1605 * Unless otherwise stated, upon reception of an unexpected INIT for
1606 * this association, the endpoint shall generate an INIT ACK with a
1607 * State Cookie. In the outbound INIT ACK the endpoint MUST copy its
1608 * current Verification Tag and peer's Verification Tag into a reserved
1609 * place within the state cookie. We shall refer to these locations as
1610 * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet
1611 * containing this INIT ACK MUST carry a Verification Tag value equal to
1612 * the Initiation Tag found in the unexpected INIT. And the INIT ACK
1613 * MUST contain a new Initiation Tag (randomly generated see Section
1614 * 5.3.1). Other parameters for the endpoint SHOULD be copied from the
1615 * existing parameters of the association (e.g. number of outbound
1616 * streams) into the INIT ACK and cookie.
1617 *
1618 * After sending out the INIT ACK, the endpoint shall take no further
1619 * actions, i.e., the existing association, including its current state,
1620 * and the corresponding TCB MUST NOT be changed.
1621 *
1622 * Note: Only when a TCB exists and the association is not in a COOKIE-
1623 * WAIT state are the Tie-Tags populated. For a normal association INIT
1624 * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be
1625 * set to 0 (indicating that no previous TCB existed). The INIT ACK and
1626 * State Cookie are populated as specified in section 5.2.1.
1627 *
1628 * Verification Tag: Not specified, but an INIT has no way of knowing
1629 * what the verification tag could be, so we ignore it.
1630 *
1631 * Inputs
1632 * (endpoint, asoc, chunk)
1633 *
1634 * Outputs
1635 * (asoc, reply_msg, msg_up, timers, counters)
1636 *
1637 * The return value is the disposition of the chunk.
1638 */
1639sctp_disposition_t sctp_sf_do_5_2_2_dupinit(const struct sctp_endpoint *ep,
1640 const struct sctp_association *asoc,
1641 const sctp_subtype_t type,
1642 void *arg,
1643 sctp_cmd_seq_t *commands)
1644{
1645 /* Call helper to do the real work for both simulataneous and
1646 * duplicate INIT chunk handling.
1647 */
1648 return sctp_sf_do_unexpected_init(ep, asoc, type, arg, commands);
1649}
1650
1651
Vlad Yasevich610ab732007-01-15 19:18:30 -08001652/*
1653 * Unexpected INIT-ACK handler.
1654 *
1655 * Section 5.2.3
1656 * If an INIT ACK received by an endpoint in any state other than the
1657 * COOKIE-WAIT state, the endpoint should discard the INIT ACK chunk.
1658 * An unexpected INIT ACK usually indicates the processing of an old or
1659 * duplicated INIT chunk.
1660*/
1661sctp_disposition_t sctp_sf_do_5_2_3_initack(const struct sctp_endpoint *ep,
1662 const struct sctp_association *asoc,
1663 const sctp_subtype_t type,
1664 void *arg, sctp_cmd_seq_t *commands)
1665{
1666 /* Per the above section, we'll discard the chunk if we have an
1667 * endpoint. If this is an OOTB INIT-ACK, treat it as such.
1668 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001669 if (ep == sctp_sk((sctp_get_ctl_sock()))->ep)
Vlad Yasevich610ab732007-01-15 19:18:30 -08001670 return sctp_sf_ootb(ep, asoc, type, arg, commands);
1671 else
1672 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
1673}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001674
1675/* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A')
1676 *
1677 * Section 5.2.4
1678 * A) In this case, the peer may have restarted.
1679 */
1680static sctp_disposition_t sctp_sf_do_dupcook_a(const struct sctp_endpoint *ep,
1681 const struct sctp_association *asoc,
1682 struct sctp_chunk *chunk,
1683 sctp_cmd_seq_t *commands,
1684 struct sctp_association *new_asoc)
1685{
1686 sctp_init_chunk_t *peer_init;
1687 struct sctp_ulpevent *ev;
1688 struct sctp_chunk *repl;
1689 struct sctp_chunk *err;
1690 sctp_disposition_t disposition;
1691
1692 /* new_asoc is a brand-new association, so these are not yet
1693 * side effects--it is safe to run them here.
1694 */
1695 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1696
1697 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
1698 sctp_source(chunk), peer_init,
1699 GFP_ATOMIC))
1700 goto nomem;
1701
1702 /* Make sure no new addresses are being added during the
1703 * restart. Though this is a pretty complicated attack
1704 * since you'd have to get inside the cookie.
1705 */
1706 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk, commands)) {
1707 return SCTP_DISPOSITION_CONSUME;
1708 }
1709
1710 /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes
1711 * the peer has restarted (Action A), it MUST NOT setup a new
1712 * association but instead resend the SHUTDOWN ACK and send an ERROR
1713 * chunk with a "Cookie Received while Shutting Down" error cause to
1714 * its peer.
1715 */
1716 if (sctp_state(asoc, SHUTDOWN_ACK_SENT)) {
1717 disposition = sctp_sf_do_9_2_reshutack(ep, asoc,
1718 SCTP_ST_CHUNK(chunk->chunk_hdr->type),
1719 chunk, commands);
1720 if (SCTP_DISPOSITION_NOMEM == disposition)
1721 goto nomem;
1722
1723 err = sctp_make_op_error(asoc, chunk,
1724 SCTP_ERROR_COOKIE_IN_SHUTDOWN,
Vlad Yasevich6383cfb2009-11-23 15:53:56 -05001725 NULL, 0, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001726 if (err)
1727 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1728 SCTP_CHUNK(err));
1729
1730 return SCTP_DISPOSITION_CONSUME;
1731 }
1732
1733 /* For now, fail any unsent/unacked data. Consider the optional
1734 * choice of resending of this data.
1735 */
1736 sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_OUTQUEUE, SCTP_NULL());
1737
Linus Torvalds1da177e2005-04-16 15:20:36 -07001738 repl = sctp_make_cookie_ack(new_asoc, chunk);
1739 if (!repl)
1740 goto nomem;
1741
Linus Torvalds1da177e2005-04-16 15:20:36 -07001742 /* Report association restart to upper layer. */
1743 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_RESTART, 0,
1744 new_asoc->c.sinit_num_ostreams,
1745 new_asoc->c.sinit_max_instreams,
Vlad Yasevicha5a35e72007-03-23 11:34:08 -07001746 NULL, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001747 if (!ev)
1748 goto nomem_ev;
1749
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001750 /* Update the content of current association. */
1751 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1752 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001753 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
1754 return SCTP_DISPOSITION_CONSUME;
1755
1756nomem_ev:
1757 sctp_chunk_free(repl);
1758nomem:
1759 return SCTP_DISPOSITION_NOMEM;
1760}
1761
1762/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B')
1763 *
1764 * Section 5.2.4
1765 * B) In this case, both sides may be attempting to start an association
1766 * at about the same time but the peer endpoint started its INIT
1767 * after responding to the local endpoint's INIT
1768 */
1769/* This case represents an initialization collision. */
1770static sctp_disposition_t sctp_sf_do_dupcook_b(const struct sctp_endpoint *ep,
1771 const struct sctp_association *asoc,
1772 struct sctp_chunk *chunk,
1773 sctp_cmd_seq_t *commands,
1774 struct sctp_association *new_asoc)
1775{
1776 sctp_init_chunk_t *peer_init;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001777 struct sctp_chunk *repl;
1778
1779 /* new_asoc is a brand-new association, so these are not yet
1780 * side effects--it is safe to run them here.
1781 */
1782 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1783 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
1784 sctp_source(chunk), peer_init,
1785 GFP_ATOMIC))
1786 goto nomem;
1787
1788 /* Update the content of current association. */
1789 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1790 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1791 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1792 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
1793 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
1794
1795 repl = sctp_make_cookie_ack(new_asoc, chunk);
1796 if (!repl)
1797 goto nomem;
1798
1799 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001800
1801 /* RFC 2960 5.1 Normal Establishment of an Association
1802 *
1803 * D) IMPLEMENTATION NOTE: An implementation may choose to
1804 * send the Communication Up notification to the SCTP user
1805 * upon reception of a valid COOKIE ECHO chunk.
Vlad Yasevich07d93962007-05-04 13:55:27 -07001806 *
1807 * Sadly, this needs to be implemented as a side-effect, because
1808 * we are not guaranteed to have set the association id of the real
1809 * association and so these notifications need to be delayed until
1810 * the association id is allocated.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001811 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001812
Vlad Yasevich07d93962007-05-04 13:55:27 -07001813 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_CHANGE, SCTP_U8(SCTP_COMM_UP));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001814
1815 /* Sockets API Draft Section 5.3.1.6
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -08001816 * When a peer sends a Adaptation Layer Indication parameter , SCTP
Linus Torvalds1da177e2005-04-16 15:20:36 -07001817 * delivers this notification to inform the application that of the
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -08001818 * peers requested adaptation layer.
Vlad Yasevich07d93962007-05-04 13:55:27 -07001819 *
1820 * This also needs to be done as a side effect for the same reason as
1821 * above.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001822 */
Vlad Yasevich07d93962007-05-04 13:55:27 -07001823 if (asoc->peer.adaptation_ind)
1824 sctp_add_cmd_sf(commands, SCTP_CMD_ADAPTATION_IND, SCTP_NULL());
Linus Torvalds1da177e2005-04-16 15:20:36 -07001825
1826 return SCTP_DISPOSITION_CONSUME;
1827
Linus Torvalds1da177e2005-04-16 15:20:36 -07001828nomem:
1829 return SCTP_DISPOSITION_NOMEM;
1830}
1831
1832/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C')
1833 *
1834 * Section 5.2.4
1835 * C) In this case, the local endpoint's cookie has arrived late.
1836 * Before it arrived, the local endpoint sent an INIT and received an
1837 * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag
1838 * but a new tag of its own.
1839 */
1840/* This case represents an initialization collision. */
1841static sctp_disposition_t sctp_sf_do_dupcook_c(const struct sctp_endpoint *ep,
1842 const struct sctp_association *asoc,
1843 struct sctp_chunk *chunk,
1844 sctp_cmd_seq_t *commands,
1845 struct sctp_association *new_asoc)
1846{
1847 /* The cookie should be silently discarded.
1848 * The endpoint SHOULD NOT change states and should leave
1849 * any timers running.
1850 */
1851 return SCTP_DISPOSITION_DISCARD;
1852}
1853
1854/* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D')
1855 *
1856 * Section 5.2.4
1857 *
1858 * D) When both local and remote tags match the endpoint should always
1859 * enter the ESTABLISHED state, if it has not already done so.
1860 */
1861/* This case represents an initialization collision. */
1862static sctp_disposition_t sctp_sf_do_dupcook_d(const struct sctp_endpoint *ep,
1863 const struct sctp_association *asoc,
1864 struct sctp_chunk *chunk,
1865 sctp_cmd_seq_t *commands,
1866 struct sctp_association *new_asoc)
1867{
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001868 struct sctp_ulpevent *ev = NULL, *ai_ev = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001869 struct sctp_chunk *repl;
1870
1871 /* Clarification from Implementor's Guide:
1872 * D) When both local and remote tags match the endpoint should
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001873 * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state.
1874 * It should stop any cookie timer that may be running and send
1875 * a COOKIE ACK.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001876 */
1877
1878 /* Don't accidentally move back into established state. */
1879 if (asoc->state < SCTP_STATE_ESTABLISHED) {
1880 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1881 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1882 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1883 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1884 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
1885 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START,
1886 SCTP_NULL());
1887
1888 /* RFC 2960 5.1 Normal Establishment of an Association
1889 *
1890 * D) IMPLEMENTATION NOTE: An implementation may choose
1891 * to send the Communication Up notification to the
1892 * SCTP user upon reception of a valid COOKIE
1893 * ECHO chunk.
1894 */
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001895 ev = sctp_ulpevent_make_assoc_change(asoc, 0,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001896 SCTP_COMM_UP, 0,
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001897 asoc->c.sinit_num_ostreams,
1898 asoc->c.sinit_max_instreams,
YOSHIFUJI Hideaki9cbcbf42007-07-19 10:44:50 +09001899 NULL, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001900 if (!ev)
1901 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001902
1903 /* Sockets API Draft Section 5.3.1.6
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -08001904 * When a peer sends a Adaptation Layer Indication parameter,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001905 * SCTP delivers this notification to inform the application
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -08001906 * that of the peers requested adaptation layer.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001907 */
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -08001908 if (asoc->peer.adaptation_ind) {
1909 ai_ev = sctp_ulpevent_make_adaptation_indication(asoc,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001910 GFP_ATOMIC);
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001911 if (!ai_ev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001912 goto nomem;
1913
Linus Torvalds1da177e2005-04-16 15:20:36 -07001914 }
1915 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001916
1917 repl = sctp_make_cookie_ack(new_asoc, chunk);
1918 if (!repl)
1919 goto nomem;
1920
Vlad Yasevich2e3216c2008-06-19 16:08:18 -07001921 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1922
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001923 if (ev)
1924 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1925 SCTP_ULPEVENT(ev));
1926 if (ai_ev)
1927 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1928 SCTP_ULPEVENT(ai_ev));
1929
Linus Torvalds1da177e2005-04-16 15:20:36 -07001930 return SCTP_DISPOSITION_CONSUME;
1931
1932nomem:
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001933 if (ai_ev)
1934 sctp_ulpevent_free(ai_ev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001935 if (ev)
1936 sctp_ulpevent_free(ev);
1937 return SCTP_DISPOSITION_NOMEM;
1938}
1939
1940/*
1941 * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying
1942 * chunk was retransmitted and then delayed in the network.
1943 *
1944 * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists
1945 *
1946 * Verification Tag: None. Do cookie validation.
1947 *
1948 * Inputs
1949 * (endpoint, asoc, chunk)
1950 *
1951 * Outputs
1952 * (asoc, reply_msg, msg_up, timers, counters)
1953 *
1954 * The return value is the disposition of the chunk.
1955 */
1956sctp_disposition_t sctp_sf_do_5_2_4_dupcook(const struct sctp_endpoint *ep,
1957 const struct sctp_association *asoc,
1958 const sctp_subtype_t type,
1959 void *arg,
1960 sctp_cmd_seq_t *commands)
1961{
1962 sctp_disposition_t retval;
1963 struct sctp_chunk *chunk = arg;
1964 struct sctp_association *new_asoc;
1965 int error = 0;
1966 char action;
1967 struct sctp_chunk *err_chk_p;
1968
1969 /* Make sure that the chunk has a valid length from the protocol
1970 * perspective. In this case check to make sure we have at least
1971 * enough for the chunk header. Cookie length verification is
1972 * done later.
1973 */
1974 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
1975 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1976 commands);
1977
1978 /* "Decode" the chunk. We have no optional parameters so we
1979 * are in good shape.
1980 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001981 chunk->subh.cookie_hdr = (struct sctp_signed_cookie *)chunk->skb->data;
Sridhar Samudrala62b08082006-05-05 17:04:43 -07001982 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
1983 sizeof(sctp_chunkhdr_t)))
1984 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001985
1986 /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
1987 * of a duplicate COOKIE ECHO match the Verification Tags of the
1988 * current association, consider the State Cookie valid even if
1989 * the lifespan is exceeded.
1990 */
1991 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
1992 &err_chk_p);
1993
1994 /* FIXME:
1995 * If the re-build failed, what is the proper error path
1996 * from here?
1997 *
1998 * [We should abort the association. --piggy]
1999 */
2000 if (!new_asoc) {
2001 /* FIXME: Several errors are possible. A bad cookie should
2002 * be silently discarded, but think about logging it too.
2003 */
2004 switch (error) {
2005 case -SCTP_IERROR_NOMEM:
2006 goto nomem;
2007
2008 case -SCTP_IERROR_STALE_COOKIE:
2009 sctp_send_stale_cookie_err(ep, asoc, chunk, commands,
2010 err_chk_p);
2011 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2012 case -SCTP_IERROR_BAD_SIG:
2013 default:
2014 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07002015 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002016 }
2017
2018 /* Compare the tie_tag in cookie with the verification tag of
2019 * current association.
2020 */
2021 action = sctp_tietags_compare(new_asoc, asoc);
2022
2023 switch (action) {
2024 case 'A': /* Association restart. */
2025 retval = sctp_sf_do_dupcook_a(ep, asoc, chunk, commands,
2026 new_asoc);
2027 break;
2028
2029 case 'B': /* Collision case B. */
2030 retval = sctp_sf_do_dupcook_b(ep, asoc, chunk, commands,
2031 new_asoc);
2032 break;
2033
2034 case 'C': /* Collision case C. */
2035 retval = sctp_sf_do_dupcook_c(ep, asoc, chunk, commands,
2036 new_asoc);
2037 break;
2038
2039 case 'D': /* Collision case D. */
2040 retval = sctp_sf_do_dupcook_d(ep, asoc, chunk, commands,
2041 new_asoc);
2042 break;
2043
2044 default: /* Discard packet for all others. */
2045 retval = sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2046 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07002047 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002048
2049 /* Delete the tempory new association. */
2050 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
2051 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
2052
2053 return retval;
2054
2055nomem:
2056 return SCTP_DISPOSITION_NOMEM;
2057}
2058
2059/*
2060 * Process an ABORT. (SHUTDOWN-PENDING state)
2061 *
2062 * See sctp_sf_do_9_1_abort().
2063 */
2064sctp_disposition_t sctp_sf_shutdown_pending_abort(
2065 const struct sctp_endpoint *ep,
2066 const struct sctp_association *asoc,
2067 const sctp_subtype_t type,
2068 void *arg,
2069 sctp_cmd_seq_t *commands)
2070{
2071 struct sctp_chunk *chunk = arg;
2072
2073 if (!sctp_vtag_verify_either(chunk, asoc))
2074 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2075
2076 /* Make sure that the ABORT chunk has a valid length.
2077 * Since this is an ABORT chunk, we have to discard it
2078 * because of the following text:
2079 * RFC 2960, Section 3.3.7
2080 * If an endpoint receives an ABORT with a format error or for an
2081 * association that doesn't exist, it MUST silently discard it.
2082 * Becasue the length is "invalid", we can't really discard just
2083 * as we do not know its true length. So, to be safe, discard the
2084 * packet.
2085 */
2086 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2087 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2088
Vlad Yasevich75205f42007-12-20 14:12:59 -08002089 /* ADD-IP: Special case for ABORT chunks
2090 * F4) One special consideration is that ABORT Chunks arriving
2091 * destined to the IP address being deleted MUST be
2092 * ignored (see Section 5.3.1 for further details).
2093 */
2094 if (SCTP_ADDR_DEL ==
2095 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2096 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
2097
Vlad Yasevich75205f42007-12-20 14:12:59 -08002098 return __sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002099}
2100
2101/*
2102 * Process an ABORT. (SHUTDOWN-SENT state)
2103 *
2104 * See sctp_sf_do_9_1_abort().
2105 */
2106sctp_disposition_t sctp_sf_shutdown_sent_abort(const struct sctp_endpoint *ep,
2107 const struct sctp_association *asoc,
2108 const sctp_subtype_t type,
2109 void *arg,
2110 sctp_cmd_seq_t *commands)
2111{
2112 struct sctp_chunk *chunk = arg;
2113
2114 if (!sctp_vtag_verify_either(chunk, asoc))
2115 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2116
2117 /* Make sure that the ABORT chunk has a valid length.
2118 * Since this is an ABORT chunk, we have to discard it
2119 * because of the following text:
2120 * RFC 2960, Section 3.3.7
2121 * If an endpoint receives an ABORT with a format error or for an
2122 * association that doesn't exist, it MUST silently discard it.
2123 * Becasue the length is "invalid", we can't really discard just
2124 * as we do not know its true length. So, to be safe, discard the
2125 * packet.
2126 */
2127 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2128 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2129
Vlad Yasevich75205f42007-12-20 14:12:59 -08002130 /* ADD-IP: Special case for ABORT chunks
2131 * F4) One special consideration is that ABORT Chunks arriving
2132 * destined to the IP address being deleted MUST be
2133 * ignored (see Section 5.3.1 for further details).
2134 */
2135 if (SCTP_ADDR_DEL ==
2136 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2137 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
2138
Linus Torvalds1da177e2005-04-16 15:20:36 -07002139 /* Stop the T2-shutdown timer. */
2140 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2141 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2142
2143 /* Stop the T5-shutdown guard timer. */
2144 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2145 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
2146
Vlad Yasevich75205f42007-12-20 14:12:59 -08002147 return __sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002148}
2149
2150/*
2151 * Process an ABORT. (SHUTDOWN-ACK-SENT state)
2152 *
2153 * See sctp_sf_do_9_1_abort().
2154 */
2155sctp_disposition_t sctp_sf_shutdown_ack_sent_abort(
2156 const struct sctp_endpoint *ep,
2157 const struct sctp_association *asoc,
2158 const sctp_subtype_t type,
2159 void *arg,
2160 sctp_cmd_seq_t *commands)
2161{
2162 /* The same T2 timer, so we should be able to use
2163 * common function with the SHUTDOWN-SENT state.
2164 */
2165 return sctp_sf_shutdown_sent_abort(ep, asoc, type, arg, commands);
2166}
2167
2168/*
2169 * Handle an Error received in COOKIE_ECHOED state.
2170 *
2171 * Only handle the error type of stale COOKIE Error, the other errors will
2172 * be ignored.
2173 *
2174 * Inputs
2175 * (endpoint, asoc, chunk)
2176 *
2177 * Outputs
2178 * (asoc, reply_msg, msg_up, timers, counters)
2179 *
2180 * The return value is the disposition of the chunk.
2181 */
2182sctp_disposition_t sctp_sf_cookie_echoed_err(const struct sctp_endpoint *ep,
2183 const struct sctp_association *asoc,
2184 const sctp_subtype_t type,
2185 void *arg,
2186 sctp_cmd_seq_t *commands)
2187{
2188 struct sctp_chunk *chunk = arg;
2189 sctp_errhdr_t *err;
2190
2191 if (!sctp_vtag_verify(chunk, asoc))
2192 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2193
2194 /* Make sure that the ERROR chunk has a valid length.
2195 * The parameter walking depends on this as well.
2196 */
2197 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
2198 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2199 commands);
2200
2201 /* Process the error here */
2202 /* FUTURE FIXME: When PR-SCTP related and other optional
2203 * parms are emitted, this will have to change to handle multiple
2204 * errors.
2205 */
2206 sctp_walk_errors(err, chunk->chunk_hdr) {
2207 if (SCTP_ERROR_STALE_COOKIE == err->cause)
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002208 return sctp_sf_do_5_2_6_stale(ep, asoc, type,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002209 arg, commands);
2210 }
2211
2212 /* It is possible to have malformed error causes, and that
2213 * will cause us to end the walk early. However, since
2214 * we are discarding the packet, there should be no adverse
2215 * affects.
2216 */
2217 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2218}
2219
2220/*
2221 * Handle a Stale COOKIE Error
2222 *
2223 * Section: 5.2.6 Handle Stale COOKIE Error
2224 * If the association is in the COOKIE-ECHOED state, the endpoint may elect
2225 * one of the following three alternatives.
2226 * ...
2227 * 3) Send a new INIT chunk to the endpoint, adding a Cookie
2228 * Preservative parameter requesting an extension to the lifetime of
2229 * the State Cookie. When calculating the time extension, an
2230 * implementation SHOULD use the RTT information measured based on the
2231 * previous COOKIE ECHO / ERROR exchange, and should add no more
2232 * than 1 second beyond the measured RTT, due to long State Cookie
2233 * lifetimes making the endpoint more subject to a replay attack.
2234 *
2235 * Verification Tag: Not explicit, but safe to ignore.
2236 *
2237 * Inputs
2238 * (endpoint, asoc, chunk)
2239 *
2240 * Outputs
2241 * (asoc, reply_msg, msg_up, timers, counters)
2242 *
2243 * The return value is the disposition of the chunk.
2244 */
2245static sctp_disposition_t sctp_sf_do_5_2_6_stale(const struct sctp_endpoint *ep,
2246 const struct sctp_association *asoc,
2247 const sctp_subtype_t type,
2248 void *arg,
2249 sctp_cmd_seq_t *commands)
2250{
2251 struct sctp_chunk *chunk = arg;
2252 time_t stale;
2253 sctp_cookie_preserve_param_t bht;
2254 sctp_errhdr_t *err;
2255 struct sctp_chunk *reply;
2256 struct sctp_bind_addr *bp;
Frank Filz3f7a87d2005-06-20 13:14:57 -07002257 int attempts = asoc->init_err_counter + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002258
Vlad Yasevich81845c22006-01-30 15:59:54 -08002259 if (attempts > asoc->max_init_attempts) {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002260 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
2261 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002262 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08002263 SCTP_PERR(SCTP_ERROR_STALE_COOKIE));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002264 return SCTP_DISPOSITION_DELETE_TCB;
2265 }
2266
2267 err = (sctp_errhdr_t *)(chunk->skb->data);
2268
2269 /* When calculating the time extension, an implementation
2270 * SHOULD use the RTT information measured based on the
2271 * previous COOKIE ECHO / ERROR exchange, and should add no
2272 * more than 1 second beyond the measured RTT, due to long
2273 * State Cookie lifetimes making the endpoint more subject to
2274 * a replay attack.
2275 * Measure of Staleness's unit is usec. (1/1000000 sec)
2276 * Suggested Cookie Life-span Increment's unit is msec.
2277 * (1/1000 sec)
2278 * In general, if you use the suggested cookie life, the value
2279 * found in the field of measure of staleness should be doubled
2280 * to give ample time to retransmit the new cookie and thus
2281 * yield a higher probability of success on the reattempt.
2282 */
Al Viro34bcca22006-11-20 17:27:15 -08002283 stale = ntohl(*(__be32 *)((u8 *)err + sizeof(sctp_errhdr_t)));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002284 stale = (stale * 2) / 1000;
2285
2286 bht.param_hdr.type = SCTP_PARAM_COOKIE_PRESERVATIVE;
2287 bht.param_hdr.length = htons(sizeof(bht));
2288 bht.lifespan_increment = htonl(stale);
2289
2290 /* Build that new INIT chunk. */
2291 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
2292 reply = sctp_make_init(asoc, bp, GFP_ATOMIC, sizeof(bht));
2293 if (!reply)
2294 goto nomem;
2295
2296 sctp_addto_chunk(reply, sizeof(bht), &bht);
2297
2298 /* Clear peer's init_tag cached in assoc as we are sending a new INIT */
2299 sctp_add_cmd_sf(commands, SCTP_CMD_CLEAR_INIT_TAG, SCTP_NULL());
2300
2301 /* Stop pending T3-rtx and heartbeat timers */
2302 sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
2303 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
2304
2305 /* Delete non-primary peer ip addresses since we are transitioning
2306 * back to the COOKIE-WAIT state
2307 */
2308 sctp_add_cmd_sf(commands, SCTP_CMD_DEL_NON_PRIMARY, SCTP_NULL());
2309
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002310 /* If we've sent any data bundled with COOKIE-ECHO we will need to
2311 * resend
Linus Torvalds1da177e2005-04-16 15:20:36 -07002312 */
Vlad Yasevichb6157d82007-10-24 15:59:16 -04002313 sctp_add_cmd_sf(commands, SCTP_CMD_T1_RETRAN,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002314 SCTP_TRANSPORT(asoc->peer.primary_path));
2315
2316 /* Cast away the const modifier, as we want to just
2317 * rerun it through as a sideffect.
2318 */
Frank Filz3f7a87d2005-06-20 13:14:57 -07002319 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_INC, SCTP_NULL());
Linus Torvalds1da177e2005-04-16 15:20:36 -07002320
2321 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2322 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
2323 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2324 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
2325 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
2326 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
2327
2328 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2329
2330 return SCTP_DISPOSITION_CONSUME;
2331
2332nomem:
2333 return SCTP_DISPOSITION_NOMEM;
2334}
2335
2336/*
2337 * Process an ABORT.
2338 *
2339 * Section: 9.1
2340 * After checking the Verification Tag, the receiving endpoint shall
2341 * remove the association from its record, and shall report the
2342 * termination to its upper layer.
2343 *
2344 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
2345 * B) Rules for packet carrying ABORT:
2346 *
2347 * - The endpoint shall always fill in the Verification Tag field of the
2348 * outbound packet with the destination endpoint's tag value if it
2349 * is known.
2350 *
2351 * - If the ABORT is sent in response to an OOTB packet, the endpoint
2352 * MUST follow the procedure described in Section 8.4.
2353 *
2354 * - The receiver MUST accept the packet if the Verification Tag
2355 * matches either its own tag, OR the tag of its peer. Otherwise, the
2356 * receiver MUST silently discard the packet and take no further
2357 * action.
2358 *
2359 * Inputs
2360 * (endpoint, asoc, chunk)
2361 *
2362 * Outputs
2363 * (asoc, reply_msg, msg_up, timers, counters)
2364 *
2365 * The return value is the disposition of the chunk.
2366 */
2367sctp_disposition_t sctp_sf_do_9_1_abort(const struct sctp_endpoint *ep,
2368 const struct sctp_association *asoc,
2369 const sctp_subtype_t type,
2370 void *arg,
2371 sctp_cmd_seq_t *commands)
2372{
2373 struct sctp_chunk *chunk = arg;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002374
2375 if (!sctp_vtag_verify_either(chunk, asoc))
2376 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2377
2378 /* Make sure that the ABORT chunk has a valid length.
2379 * Since this is an ABORT chunk, we have to discard it
2380 * because of the following text:
2381 * RFC 2960, Section 3.3.7
2382 * If an endpoint receives an ABORT with a format error or for an
2383 * association that doesn't exist, it MUST silently discard it.
2384 * Becasue the length is "invalid", we can't really discard just
2385 * as we do not know its true length. So, to be safe, discard the
2386 * packet.
2387 */
2388 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2389 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2390
Vlad Yasevich75205f42007-12-20 14:12:59 -08002391 /* ADD-IP: Special case for ABORT chunks
2392 * F4) One special consideration is that ABORT Chunks arriving
2393 * destined to the IP address being deleted MUST be
2394 * ignored (see Section 5.3.1 for further details).
2395 */
2396 if (SCTP_ADDR_DEL ==
2397 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2398 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
2399
2400 return __sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
2401}
2402
2403static sctp_disposition_t __sctp_sf_do_9_1_abort(const struct sctp_endpoint *ep,
2404 const struct sctp_association *asoc,
2405 const sctp_subtype_t type,
2406 void *arg,
2407 sctp_cmd_seq_t *commands)
2408{
2409 struct sctp_chunk *chunk = arg;
2410 unsigned len;
2411 __be16 error = SCTP_ERROR_NO_ERROR;
2412
Linus Torvalds1da177e2005-04-16 15:20:36 -07002413 /* See if we have an error cause code in the chunk. */
2414 len = ntohs(chunk->chunk_hdr->length);
2415 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
2416 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2417
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002418 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNRESET));
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002419 /* ASSOC_FAILED will DELETE_TCB. */
Al Viro5be291f2006-11-20 17:01:06 -08002420 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, SCTP_PERR(error));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002421 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
2422 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
2423
2424 return SCTP_DISPOSITION_ABORT;
2425}
2426
2427/*
2428 * Process an ABORT. (COOKIE-WAIT state)
2429 *
2430 * See sctp_sf_do_9_1_abort() above.
2431 */
2432sctp_disposition_t sctp_sf_cookie_wait_abort(const struct sctp_endpoint *ep,
2433 const struct sctp_association *asoc,
2434 const sctp_subtype_t type,
2435 void *arg,
2436 sctp_cmd_seq_t *commands)
2437{
2438 struct sctp_chunk *chunk = arg;
2439 unsigned len;
Al Virof94c0192006-11-20 17:00:25 -08002440 __be16 error = SCTP_ERROR_NO_ERROR;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002441
2442 if (!sctp_vtag_verify_either(chunk, asoc))
2443 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2444
2445 /* Make sure that the ABORT chunk has a valid length.
2446 * Since this is an ABORT chunk, we have to discard it
2447 * because of the following text:
2448 * RFC 2960, Section 3.3.7
2449 * If an endpoint receives an ABORT with a format error or for an
2450 * association that doesn't exist, it MUST silently discard it.
2451 * Becasue the length is "invalid", we can't really discard just
2452 * as we do not know its true length. So, to be safe, discard the
2453 * packet.
2454 */
2455 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2456 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2457
2458 /* See if we have an error cause code in the chunk. */
2459 len = ntohs(chunk->chunk_hdr->length);
2460 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
2461 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2462
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002463 return sctp_stop_t1_and_abort(commands, error, ECONNREFUSED, asoc,
2464 chunk->transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002465}
2466
2467/*
2468 * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state)
2469 */
2470sctp_disposition_t sctp_sf_cookie_wait_icmp_abort(const struct sctp_endpoint *ep,
2471 const struct sctp_association *asoc,
2472 const sctp_subtype_t type,
2473 void *arg,
2474 sctp_cmd_seq_t *commands)
2475{
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002476 return sctp_stop_t1_and_abort(commands, SCTP_ERROR_NO_ERROR,
2477 ENOPROTOOPT, asoc,
Frank Filz3f7a87d2005-06-20 13:14:57 -07002478 (struct sctp_transport *)arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002479}
2480
2481/*
2482 * Process an ABORT. (COOKIE-ECHOED state)
2483 */
2484sctp_disposition_t sctp_sf_cookie_echoed_abort(const struct sctp_endpoint *ep,
2485 const struct sctp_association *asoc,
2486 const sctp_subtype_t type,
2487 void *arg,
2488 sctp_cmd_seq_t *commands)
2489{
2490 /* There is a single T1 timer, so we should be able to use
2491 * common function with the COOKIE-WAIT state.
2492 */
2493 return sctp_sf_cookie_wait_abort(ep, asoc, type, arg, commands);
2494}
2495
2496/*
2497 * Stop T1 timer and abort association with "INIT failed".
2498 *
2499 * This is common code called by several sctp_sf_*_abort() functions above.
2500 */
Adrian Bunk52c1da32005-06-23 22:05:33 -07002501static sctp_disposition_t sctp_stop_t1_and_abort(sctp_cmd_seq_t *commands,
Al Virof94c0192006-11-20 17:00:25 -08002502 __be16 error, int sk_err,
Frank Filz3f7a87d2005-06-20 13:14:57 -07002503 const struct sctp_association *asoc,
2504 struct sctp_transport *transport)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002505{
Frank Filz3f7a87d2005-06-20 13:14:57 -07002506 SCTP_DEBUG_PRINTK("ABORT received (INIT).\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07002507 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2508 SCTP_STATE(SCTP_STATE_CLOSED));
2509 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
2510 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2511 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002512 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(sk_err));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002513 /* CMD_INIT_FAILED will DELETE_TCB. */
2514 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08002515 SCTP_PERR(error));
Frank Filz3f7a87d2005-06-20 13:14:57 -07002516 return SCTP_DISPOSITION_ABORT;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002517}
2518
2519/*
2520 * sctp_sf_do_9_2_shut
2521 *
2522 * Section: 9.2
2523 * Upon the reception of the SHUTDOWN, the peer endpoint shall
2524 * - enter the SHUTDOWN-RECEIVED state,
2525 *
2526 * - stop accepting new data from its SCTP user
2527 *
2528 * - verify, by checking the Cumulative TSN Ack field of the chunk,
2529 * that all its outstanding DATA chunks have been received by the
2530 * SHUTDOWN sender.
2531 *
2532 * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT
2533 * send a SHUTDOWN in response to a ULP request. And should discard
2534 * subsequent SHUTDOWN chunks.
2535 *
2536 * If there are still outstanding DATA chunks left, the SHUTDOWN
2537 * receiver shall continue to follow normal data transmission
2538 * procedures defined in Section 6 until all outstanding DATA chunks
2539 * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept
2540 * new data from its SCTP user.
2541 *
2542 * Verification Tag: 8.5 Verification Tag [Normal verification]
2543 *
2544 * Inputs
2545 * (endpoint, asoc, chunk)
2546 *
2547 * Outputs
2548 * (asoc, reply_msg, msg_up, timers, counters)
2549 *
2550 * The return value is the disposition of the chunk.
2551 */
2552sctp_disposition_t sctp_sf_do_9_2_shutdown(const struct sctp_endpoint *ep,
2553 const struct sctp_association *asoc,
2554 const sctp_subtype_t type,
2555 void *arg,
2556 sctp_cmd_seq_t *commands)
2557{
2558 struct sctp_chunk *chunk = arg;
2559 sctp_shutdownhdr_t *sdh;
2560 sctp_disposition_t disposition;
2561 struct sctp_ulpevent *ev;
Wei Yongjundf10eec2008-10-23 01:00:21 -07002562 __u32 ctsn;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002563
2564 if (!sctp_vtag_verify(chunk, asoc))
2565 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2566
2567 /* Make sure that the SHUTDOWN chunk has a valid length. */
2568 if (!sctp_chunk_length_valid(chunk,
2569 sizeof(struct sctp_shutdown_chunk_t)))
2570 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2571 commands);
2572
2573 /* Convert the elaborate header. */
2574 sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
2575 skb_pull(chunk->skb, sizeof(sctp_shutdownhdr_t));
2576 chunk->subh.shutdown_hdr = sdh;
Wei Yongjundf10eec2008-10-23 01:00:21 -07002577 ctsn = ntohl(sdh->cum_tsn_ack);
2578
Wei Yongjuna2f36ee2009-08-22 11:24:00 +08002579 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
2580 SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn);
2581 SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc->ctsn_ack_point);
2582 return SCTP_DISPOSITION_DISCARD;
2583 }
2584
Wei Yongjundf10eec2008-10-23 01:00:21 -07002585 /* If Cumulative TSN Ack beyond the max tsn currently
2586 * send, terminating the association and respond to the
2587 * sender with an ABORT.
2588 */
2589 if (!TSN_lt(ctsn, asoc->next_tsn))
2590 return sctp_sf_violation_ctsn(ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002591
Sridhar Samudralaeb0e0072005-09-22 23:48:38 -07002592 /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT
2593 * When a peer sends a SHUTDOWN, SCTP delivers this notification to
2594 * inform the application that it should cease sending data.
2595 */
2596 ev = sctp_ulpevent_make_shutdown_event(asoc, 0, GFP_ATOMIC);
2597 if (!ev) {
2598 disposition = SCTP_DISPOSITION_NOMEM;
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002599 goto out;
Sridhar Samudralaeb0e0072005-09-22 23:48:38 -07002600 }
2601 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
2602
Linus Torvalds1da177e2005-04-16 15:20:36 -07002603 /* Upon the reception of the SHUTDOWN, the peer endpoint shall
2604 * - enter the SHUTDOWN-RECEIVED state,
2605 * - stop accepting new data from its SCTP user
2606 *
2607 * [This is implicit in the new state.]
2608 */
2609 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2610 SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED));
2611 disposition = SCTP_DISPOSITION_CONSUME;
2612
2613 if (sctp_outq_is_empty(&asoc->outqueue)) {
2614 disposition = sctp_sf_do_9_2_shutdown_ack(ep, asoc, type,
2615 arg, commands);
2616 }
2617
2618 if (SCTP_DISPOSITION_NOMEM == disposition)
2619 goto out;
2620
2621 /* - verify, by checking the Cumulative TSN Ack field of the
2622 * chunk, that all its outstanding DATA chunks have been
2623 * received by the SHUTDOWN sender.
2624 */
2625 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
Al Viro2178eda2006-11-20 17:26:53 -08002626 SCTP_BE32(chunk->subh.shutdown_hdr->cum_tsn_ack));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002627
Linus Torvalds1da177e2005-04-16 15:20:36 -07002628out:
2629 return disposition;
2630}
2631
Wei Yongjun2e3f92d2008-10-23 01:01:18 -07002632/*
2633 * sctp_sf_do_9_2_shut_ctsn
2634 *
2635 * Once an endpoint has reached the SHUTDOWN-RECEIVED state,
2636 * it MUST NOT send a SHUTDOWN in response to a ULP request.
2637 * The Cumulative TSN Ack of the received SHUTDOWN chunk
2638 * MUST be processed.
2639 */
2640sctp_disposition_t sctp_sf_do_9_2_shut_ctsn(const struct sctp_endpoint *ep,
2641 const struct sctp_association *asoc,
2642 const sctp_subtype_t type,
2643 void *arg,
2644 sctp_cmd_seq_t *commands)
2645{
2646 struct sctp_chunk *chunk = arg;
2647 sctp_shutdownhdr_t *sdh;
Wei Yongjuna2f36ee2009-08-22 11:24:00 +08002648 __u32 ctsn;
Wei Yongjun2e3f92d2008-10-23 01:01:18 -07002649
2650 if (!sctp_vtag_verify(chunk, asoc))
2651 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2652
2653 /* Make sure that the SHUTDOWN chunk has a valid length. */
2654 if (!sctp_chunk_length_valid(chunk,
2655 sizeof(struct sctp_shutdown_chunk_t)))
2656 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2657 commands);
2658
2659 sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
Wei Yongjuna2f36ee2009-08-22 11:24:00 +08002660 ctsn = ntohl(sdh->cum_tsn_ack);
2661
2662 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
2663 SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn);
2664 SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc->ctsn_ack_point);
2665 return SCTP_DISPOSITION_DISCARD;
2666 }
Wei Yongjun2e3f92d2008-10-23 01:01:18 -07002667
2668 /* If Cumulative TSN Ack beyond the max tsn currently
2669 * send, terminating the association and respond to the
2670 * sender with an ABORT.
2671 */
Wei Yongjuna2f36ee2009-08-22 11:24:00 +08002672 if (!TSN_lt(ctsn, asoc->next_tsn))
Wei Yongjun2e3f92d2008-10-23 01:01:18 -07002673 return sctp_sf_violation_ctsn(ep, asoc, type, arg, commands);
2674
2675 /* verify, by checking the Cumulative TSN Ack field of the
2676 * chunk, that all its outstanding DATA chunks have been
2677 * received by the SHUTDOWN sender.
2678 */
2679 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
2680 SCTP_BE32(sdh->cum_tsn_ack));
2681
2682 return SCTP_DISPOSITION_CONSUME;
2683}
2684
Linus Torvalds1da177e2005-04-16 15:20:36 -07002685/* RFC 2960 9.2
2686 * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk
2687 * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination
2688 * transport addresses (either in the IP addresses or in the INIT chunk)
2689 * that belong to this association, it should discard the INIT chunk and
2690 * retransmit the SHUTDOWN ACK chunk.
2691 */
2692sctp_disposition_t sctp_sf_do_9_2_reshutack(const struct sctp_endpoint *ep,
2693 const struct sctp_association *asoc,
2694 const sctp_subtype_t type,
2695 void *arg,
2696 sctp_cmd_seq_t *commands)
2697{
2698 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
2699 struct sctp_chunk *reply;
2700
Vlad Yasevichece25df2007-09-07 16:30:54 -04002701 /* Make sure that the chunk has a valid length */
2702 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
2703 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2704 commands);
2705
Linus Torvalds1da177e2005-04-16 15:20:36 -07002706 /* Since we are not going to really process this INIT, there
2707 * is no point in verifying chunk boundries. Just generate
2708 * the SHUTDOWN ACK.
2709 */
2710 reply = sctp_make_shutdown_ack(asoc, chunk);
2711 if (NULL == reply)
2712 goto nomem;
2713
2714 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
2715 * the T2-SHUTDOWN timer.
2716 */
2717 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
2718
2719 /* and restart the T2-shutdown timer. */
2720 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2721 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2722
2723 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2724
2725 return SCTP_DISPOSITION_CONSUME;
2726nomem:
2727 return SCTP_DISPOSITION_NOMEM;
2728}
2729
2730/*
2731 * sctp_sf_do_ecn_cwr
2732 *
2733 * Section: Appendix A: Explicit Congestion Notification
2734 *
2735 * CWR:
2736 *
2737 * RFC 2481 details a specific bit for a sender to send in the header of
2738 * its next outbound TCP segment to indicate to its peer that it has
2739 * reduced its congestion window. This is termed the CWR bit. For
2740 * SCTP the same indication is made by including the CWR chunk.
2741 * This chunk contains one data element, i.e. the TSN number that
2742 * was sent in the ECNE chunk. This element represents the lowest
2743 * TSN number in the datagram that was originally marked with the
2744 * CE bit.
2745 *
2746 * Verification Tag: 8.5 Verification Tag [Normal verification]
2747 * Inputs
2748 * (endpoint, asoc, chunk)
2749 *
2750 * Outputs
2751 * (asoc, reply_msg, msg_up, timers, counters)
2752 *
2753 * The return value is the disposition of the chunk.
2754 */
2755sctp_disposition_t sctp_sf_do_ecn_cwr(const struct sctp_endpoint *ep,
2756 const struct sctp_association *asoc,
2757 const sctp_subtype_t type,
2758 void *arg,
2759 sctp_cmd_seq_t *commands)
2760{
2761 sctp_cwrhdr_t *cwr;
2762 struct sctp_chunk *chunk = arg;
Al Viro34bcca22006-11-20 17:27:15 -08002763 u32 lowest_tsn;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002764
2765 if (!sctp_vtag_verify(chunk, asoc))
2766 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2767
2768 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2769 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2770 commands);
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002771
Linus Torvalds1da177e2005-04-16 15:20:36 -07002772 cwr = (sctp_cwrhdr_t *) chunk->skb->data;
2773 skb_pull(chunk->skb, sizeof(sctp_cwrhdr_t));
2774
Al Viro34bcca22006-11-20 17:27:15 -08002775 lowest_tsn = ntohl(cwr->lowest_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002776
2777 /* Does this CWR ack the last sent congestion notification? */
Al Viro34bcca22006-11-20 17:27:15 -08002778 if (TSN_lte(asoc->last_ecne_tsn, lowest_tsn)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002779 /* Stop sending ECNE. */
2780 sctp_add_cmd_sf(commands,
2781 SCTP_CMD_ECN_CWR,
Al Viro34bcca22006-11-20 17:27:15 -08002782 SCTP_U32(lowest_tsn));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002783 }
2784 return SCTP_DISPOSITION_CONSUME;
2785}
2786
2787/*
2788 * sctp_sf_do_ecne
2789 *
2790 * Section: Appendix A: Explicit Congestion Notification
2791 *
2792 * ECN-Echo
2793 *
2794 * RFC 2481 details a specific bit for a receiver to send back in its
2795 * TCP acknowledgements to notify the sender of the Congestion
2796 * Experienced (CE) bit having arrived from the network. For SCTP this
2797 * same indication is made by including the ECNE chunk. This chunk
2798 * contains one data element, i.e. the lowest TSN associated with the IP
2799 * datagram marked with the CE bit.....
2800 *
2801 * Verification Tag: 8.5 Verification Tag [Normal verification]
2802 * Inputs
2803 * (endpoint, asoc, chunk)
2804 *
2805 * Outputs
2806 * (asoc, reply_msg, msg_up, timers, counters)
2807 *
2808 * The return value is the disposition of the chunk.
2809 */
2810sctp_disposition_t sctp_sf_do_ecne(const struct sctp_endpoint *ep,
2811 const struct sctp_association *asoc,
2812 const sctp_subtype_t type,
2813 void *arg,
2814 sctp_cmd_seq_t *commands)
2815{
2816 sctp_ecnehdr_t *ecne;
2817 struct sctp_chunk *chunk = arg;
2818
2819 if (!sctp_vtag_verify(chunk, asoc))
2820 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2821
2822 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2823 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2824 commands);
2825
2826 ecne = (sctp_ecnehdr_t *) chunk->skb->data;
2827 skb_pull(chunk->skb, sizeof(sctp_ecnehdr_t));
2828
2829 /* If this is a newer ECNE than the last CWR packet we sent out */
2830 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_ECNE,
2831 SCTP_U32(ntohl(ecne->lowest_tsn)));
2832
2833 return SCTP_DISPOSITION_CONSUME;
2834}
2835
2836/*
2837 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
2838 *
2839 * The SCTP endpoint MUST always acknowledge the reception of each valid
2840 * DATA chunk.
2841 *
2842 * The guidelines on delayed acknowledgement algorithm specified in
2843 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
2844 * acknowledgement SHOULD be generated for at least every second packet
2845 * (not every second DATA chunk) received, and SHOULD be generated within
2846 * 200 ms of the arrival of any unacknowledged DATA chunk. In some
2847 * situations it may be beneficial for an SCTP transmitter to be more
2848 * conservative than the algorithms detailed in this document allow.
2849 * However, an SCTP transmitter MUST NOT be more aggressive than the
2850 * following algorithms allow.
2851 *
2852 * A SCTP receiver MUST NOT generate more than one SACK for every
2853 * incoming packet, other than to update the offered window as the
2854 * receiving application consumes new data.
2855 *
2856 * Verification Tag: 8.5 Verification Tag [Normal verification]
2857 *
2858 * Inputs
2859 * (endpoint, asoc, chunk)
2860 *
2861 * Outputs
2862 * (asoc, reply_msg, msg_up, timers, counters)
2863 *
2864 * The return value is the disposition of the chunk.
2865 */
2866sctp_disposition_t sctp_sf_eat_data_6_2(const struct sctp_endpoint *ep,
2867 const struct sctp_association *asoc,
2868 const sctp_subtype_t type,
2869 void *arg,
2870 sctp_cmd_seq_t *commands)
2871{
2872 struct sctp_chunk *chunk = arg;
Wei Yongjun6dc76942009-11-23 15:53:53 -05002873 sctp_arg_t force = SCTP_NOFORCE();
Linus Torvalds1da177e2005-04-16 15:20:36 -07002874 int error;
2875
2876 if (!sctp_vtag_verify(chunk, asoc)) {
2877 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
2878 SCTP_NULL());
2879 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002880 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002881
2882 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
2883 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2884 commands);
2885
2886 error = sctp_eat_data(asoc, chunk, commands );
2887 switch (error) {
2888 case SCTP_IERROR_NO_ERROR:
2889 break;
2890 case SCTP_IERROR_HIGH_TSN:
2891 case SCTP_IERROR_BAD_STREAM:
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07002892 SCTP_INC_STATS(SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002893 goto discard_noforce;
2894 case SCTP_IERROR_DUP_TSN:
2895 case SCTP_IERROR_IGNORE_TSN:
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07002896 SCTP_INC_STATS(SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002897 goto discard_force;
2898 case SCTP_IERROR_NO_DATA:
2899 goto consume;
Vlad Yasevichf1751c52009-09-04 18:21:03 -04002900 case SCTP_IERROR_PROTO_VIOLATION:
2901 return sctp_sf_abort_violation(ep, asoc, chunk, commands,
2902 (u8 *)chunk->subh.data_hdr, sizeof(sctp_datahdr_t));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002903 default:
2904 BUG();
2905 }
2906
Wei Yongjun6dc76942009-11-23 15:53:53 -05002907 if (chunk->chunk_hdr->flags & SCTP_DATA_SACK_IMM)
2908 force = SCTP_FORCE();
2909
Linus Torvalds1da177e2005-04-16 15:20:36 -07002910 if (asoc->autoclose) {
2911 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2912 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
2913 }
2914
2915 /* If this is the last chunk in a packet, we need to count it
2916 * toward sack generation. Note that we need to SACK every
2917 * OTHER packet containing data chunks, EVEN IF WE DISCARD
2918 * THEM. We elect to NOT generate SACK's if the chunk fails
2919 * the verification tag test.
2920 *
2921 * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2922 *
2923 * The SCTP endpoint MUST always acknowledge the reception of
2924 * each valid DATA chunk.
2925 *
2926 * The guidelines on delayed acknowledgement algorithm
2927 * specified in Section 4.2 of [RFC2581] SHOULD be followed.
2928 * Specifically, an acknowledgement SHOULD be generated for at
2929 * least every second packet (not every second DATA chunk)
2930 * received, and SHOULD be generated within 200 ms of the
2931 * arrival of any unacknowledged DATA chunk. In some
2932 * situations it may be beneficial for an SCTP transmitter to
2933 * be more conservative than the algorithms detailed in this
2934 * document allow. However, an SCTP transmitter MUST NOT be
2935 * more aggressive than the following algorithms allow.
2936 */
Frank Filz52ccb8e2005-12-22 11:36:46 -08002937 if (chunk->end_of_packet)
Wei Yongjun6dc76942009-11-23 15:53:53 -05002938 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002939
Linus Torvalds1da177e2005-04-16 15:20:36 -07002940 return SCTP_DISPOSITION_CONSUME;
2941
2942discard_force:
2943 /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2944 *
2945 * When a packet arrives with duplicate DATA chunk(s) and with
2946 * no new DATA chunk(s), the endpoint MUST immediately send a
2947 * SACK with no delay. If a packet arrives with duplicate
2948 * DATA chunk(s) bundled with new DATA chunks, the endpoint
2949 * MAY immediately send a SACK. Normally receipt of duplicate
2950 * DATA chunks will occur when the original SACK chunk was lost
2951 * and the peer's RTO has expired. The duplicate TSN number(s)
2952 * SHOULD be reported in the SACK as duplicate.
2953 */
2954 /* In our case, we split the MAY SACK advice up whether or not
2955 * the last chunk is a duplicate.'
2956 */
2957 if (chunk->end_of_packet)
2958 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
2959 return SCTP_DISPOSITION_DISCARD;
2960
2961discard_noforce:
Frank Filz52ccb8e2005-12-22 11:36:46 -08002962 if (chunk->end_of_packet)
Wei Yongjun6dc76942009-11-23 15:53:53 -05002963 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002964
Linus Torvalds1da177e2005-04-16 15:20:36 -07002965 return SCTP_DISPOSITION_DISCARD;
2966consume:
2967 return SCTP_DISPOSITION_CONSUME;
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002968
Linus Torvalds1da177e2005-04-16 15:20:36 -07002969}
2970
2971/*
2972 * sctp_sf_eat_data_fast_4_4
2973 *
2974 * Section: 4 (4)
2975 * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received
2976 * DATA chunks without delay.
2977 *
2978 * Verification Tag: 8.5 Verification Tag [Normal verification]
2979 * Inputs
2980 * (endpoint, asoc, chunk)
2981 *
2982 * Outputs
2983 * (asoc, reply_msg, msg_up, timers, counters)
2984 *
2985 * The return value is the disposition of the chunk.
2986 */
2987sctp_disposition_t sctp_sf_eat_data_fast_4_4(const struct sctp_endpoint *ep,
2988 const struct sctp_association *asoc,
2989 const sctp_subtype_t type,
2990 void *arg,
2991 sctp_cmd_seq_t *commands)
2992{
2993 struct sctp_chunk *chunk = arg;
2994 int error;
2995
2996 if (!sctp_vtag_verify(chunk, asoc)) {
2997 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
2998 SCTP_NULL());
2999 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3000 }
3001
3002 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
3003 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3004 commands);
3005
3006 error = sctp_eat_data(asoc, chunk, commands );
3007 switch (error) {
3008 case SCTP_IERROR_NO_ERROR:
3009 case SCTP_IERROR_HIGH_TSN:
3010 case SCTP_IERROR_DUP_TSN:
3011 case SCTP_IERROR_IGNORE_TSN:
3012 case SCTP_IERROR_BAD_STREAM:
3013 break;
3014 case SCTP_IERROR_NO_DATA:
3015 goto consume;
Vlad Yasevichf1751c52009-09-04 18:21:03 -04003016 case SCTP_IERROR_PROTO_VIOLATION:
3017 return sctp_sf_abort_violation(ep, asoc, chunk, commands,
3018 (u8 *)chunk->subh.data_hdr, sizeof(sctp_datahdr_t));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003019 default:
3020 BUG();
3021 }
3022
3023 /* Go a head and force a SACK, since we are shutting down. */
3024
3025 /* Implementor's Guide.
3026 *
3027 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3028 * respond to each received packet containing one or more DATA chunk(s)
3029 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3030 */
3031 if (chunk->end_of_packet) {
3032 /* We must delay the chunk creation since the cumulative
3033 * TSN has not been updated yet.
3034 */
3035 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
3036 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3037 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3038 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3039 }
3040
3041consume:
3042 return SCTP_DISPOSITION_CONSUME;
3043}
3044
3045/*
3046 * Section: 6.2 Processing a Received SACK
3047 * D) Any time a SACK arrives, the endpoint performs the following:
3048 *
3049 * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point,
3050 * then drop the SACK. Since Cumulative TSN Ack is monotonically
3051 * increasing, a SACK whose Cumulative TSN Ack is less than the
3052 * Cumulative TSN Ack Point indicates an out-of-order SACK.
3053 *
3054 * ii) Set rwnd equal to the newly received a_rwnd minus the number
3055 * of bytes still outstanding after processing the Cumulative TSN Ack
3056 * and the Gap Ack Blocks.
3057 *
3058 * iii) If the SACK is missing a TSN that was previously
3059 * acknowledged via a Gap Ack Block (e.g., the data receiver
3060 * reneged on the data), then mark the corresponding DATA chunk
3061 * as available for retransmit: Mark it as missing for fast
3062 * retransmit as described in Section 7.2.4 and if no retransmit
3063 * timer is running for the destination address to which the DATA
3064 * chunk was originally transmitted, then T3-rtx is started for
3065 * that destination address.
3066 *
3067 * Verification Tag: 8.5 Verification Tag [Normal verification]
3068 *
3069 * Inputs
3070 * (endpoint, asoc, chunk)
3071 *
3072 * Outputs
3073 * (asoc, reply_msg, msg_up, timers, counters)
3074 *
3075 * The return value is the disposition of the chunk.
3076 */
3077sctp_disposition_t sctp_sf_eat_sack_6_2(const struct sctp_endpoint *ep,
3078 const struct sctp_association *asoc,
3079 const sctp_subtype_t type,
3080 void *arg,
3081 sctp_cmd_seq_t *commands)
3082{
3083 struct sctp_chunk *chunk = arg;
3084 sctp_sackhdr_t *sackh;
3085 __u32 ctsn;
3086
3087 if (!sctp_vtag_verify(chunk, asoc))
3088 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3089
3090 /* Make sure that the SACK chunk has a valid length. */
3091 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_sack_chunk_t)))
3092 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3093 commands);
3094
3095 /* Pull the SACK chunk from the data buffer */
3096 sackh = sctp_sm_pull_sack(chunk);
3097 /* Was this a bogus SACK? */
3098 if (!sackh)
3099 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3100 chunk->subh.sack_hdr = sackh;
3101 ctsn = ntohl(sackh->cum_tsn_ack);
3102
3103 /* i) If Cumulative TSN Ack is less than the Cumulative TSN
3104 * Ack Point, then drop the SACK. Since Cumulative TSN
3105 * Ack is monotonically increasing, a SACK whose
3106 * Cumulative TSN Ack is less than the Cumulative TSN Ack
3107 * Point indicates an out-of-order SACK.
3108 */
3109 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
3110 SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn);
3111 SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc->ctsn_ack_point);
3112 return SCTP_DISPOSITION_DISCARD;
3113 }
3114
Wei Yongjunaecedea2007-08-02 16:57:44 +08003115 /* If Cumulative TSN Ack beyond the max tsn currently
3116 * send, terminating the association and respond to the
3117 * sender with an ABORT.
3118 */
3119 if (!TSN_lt(ctsn, asoc->next_tsn))
3120 return sctp_sf_violation_ctsn(ep, asoc, type, arg, commands);
3121
Linus Torvalds1da177e2005-04-16 15:20:36 -07003122 /* Return this SACK for further processing. */
3123 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_SACKH(sackh));
3124
3125 /* Note: We do the rest of the work on the PROCESS_SACK
3126 * sideeffect.
3127 */
3128 return SCTP_DISPOSITION_CONSUME;
3129}
3130
3131/*
3132 * Generate an ABORT in response to a packet.
3133 *
Jerome Forissier047a2422005-04-28 11:58:43 -07003134 * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41
Linus Torvalds1da177e2005-04-16 15:20:36 -07003135 *
Jerome Forissier047a2422005-04-28 11:58:43 -07003136 * 8) The receiver should respond to the sender of the OOTB packet with
3137 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3138 * MUST fill in the Verification Tag field of the outbound packet
3139 * with the value found in the Verification Tag field of the OOTB
3140 * packet and set the T-bit in the Chunk Flags to indicate that the
3141 * Verification Tag is reflected. After sending this ABORT, the
3142 * receiver of the OOTB packet shall discard the OOTB packet and take
3143 * no further action.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003144 *
3145 * Verification Tag:
3146 *
3147 * The return value is the disposition of the chunk.
3148*/
Vlad Yasevichece25df2007-09-07 16:30:54 -04003149static sctp_disposition_t sctp_sf_tabort_8_4_8(const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003150 const struct sctp_association *asoc,
3151 const sctp_subtype_t type,
3152 void *arg,
3153 sctp_cmd_seq_t *commands)
3154{
3155 struct sctp_packet *packet = NULL;
3156 struct sctp_chunk *chunk = arg;
3157 struct sctp_chunk *abort;
3158
3159 packet = sctp_ootb_pkt_new(asoc, chunk);
3160
3161 if (packet) {
3162 /* Make an ABORT. The T bit will be set if the asoc
3163 * is NULL.
3164 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003165 abort = sctp_make_abort(asoc, chunk, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003166 if (!abort) {
3167 sctp_ootb_pkt_free(packet);
3168 return SCTP_DISPOSITION_NOMEM;
3169 }
3170
Jerome Forissier047a2422005-04-28 11:58:43 -07003171 /* Reflect vtag if T-Bit is set */
3172 if (sctp_test_T_bit(abort))
3173 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3174
Linus Torvalds1da177e2005-04-16 15:20:36 -07003175 /* Set the skb to the belonging sock for accounting. */
3176 abort->skb->sk = ep->base.sk;
3177
3178 sctp_packet_append_chunk(packet, abort);
3179
3180 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3181 SCTP_PACKET(packet));
3182
3183 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
3184
Vlad Yasevichd3f25962007-09-07 11:47:45 -04003185 sctp_sf_pdiscard(ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003186 return SCTP_DISPOSITION_CONSUME;
3187 }
3188
3189 return SCTP_DISPOSITION_NOMEM;
3190}
3191
3192/*
3193 * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR
3194 * event as ULP notification for each cause included in the chunk.
3195 *
3196 * API 5.3.1.3 - SCTP_REMOTE_ERROR
3197 *
3198 * The return value is the disposition of the chunk.
3199*/
3200sctp_disposition_t sctp_sf_operr_notify(const struct sctp_endpoint *ep,
3201 const struct sctp_association *asoc,
3202 const sctp_subtype_t type,
3203 void *arg,
3204 sctp_cmd_seq_t *commands)
3205{
3206 struct sctp_chunk *chunk = arg;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003207
3208 if (!sctp_vtag_verify(chunk, asoc))
3209 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3210
3211 /* Make sure that the ERROR chunk has a valid length. */
3212 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
3213 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3214 commands);
3215
Wei Yongjun3df26782009-03-02 06:46:51 +00003216 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_OPERR,
3217 SCTP_CHUNK(chunk));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003218
Linus Torvalds1da177e2005-04-16 15:20:36 -07003219 return SCTP_DISPOSITION_CONSUME;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003220}
3221
3222/*
3223 * Process an inbound SHUTDOWN ACK.
3224 *
3225 * From Section 9.2:
3226 * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3227 * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its
3228 * peer, and remove all record of the association.
3229 *
3230 * The return value is the disposition.
3231 */
3232sctp_disposition_t sctp_sf_do_9_2_final(const struct sctp_endpoint *ep,
3233 const struct sctp_association *asoc,
3234 const sctp_subtype_t type,
3235 void *arg,
3236 sctp_cmd_seq_t *commands)
3237{
3238 struct sctp_chunk *chunk = arg;
3239 struct sctp_chunk *reply;
3240 struct sctp_ulpevent *ev;
3241
3242 if (!sctp_vtag_verify(chunk, asoc))
3243 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3244
3245 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3246 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3247 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3248 commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003249 /* 10.2 H) SHUTDOWN COMPLETE notification
3250 *
3251 * When SCTP completes the shutdown procedures (section 9.2) this
3252 * notification is passed to the upper layer.
3253 */
3254 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
Vlad Yasevicha5a35e72007-03-23 11:34:08 -07003255 0, 0, 0, NULL, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003256 if (!ev)
3257 goto nomem;
3258
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07003259 /* ...send a SHUTDOWN COMPLETE chunk to its peer, */
3260 reply = sctp_make_shutdown_complete(asoc, chunk);
3261 if (!reply)
3262 goto nomem_chunk;
3263
3264 /* Do all the commands now (after allocation), so that we
3265 * have consistent state if memory allocation failes
3266 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003267 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
3268
3269 /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3270 * stop the T2-shutdown timer,
3271 */
3272 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3273 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3274
3275 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3276 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
3277
Linus Torvalds1da177e2005-04-16 15:20:36 -07003278 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3279 SCTP_STATE(SCTP_STATE_CLOSED));
3280 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
3281 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3282 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
3283
3284 /* ...and remove all record of the association. */
3285 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
3286 return SCTP_DISPOSITION_DELETE_TCB;
3287
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07003288nomem_chunk:
3289 sctp_ulpevent_free(ev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003290nomem:
3291 return SCTP_DISPOSITION_NOMEM;
3292}
3293
3294/*
Jerome Forissier047a2422005-04-28 11:58:43 -07003295 * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41.
3296 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003297 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3298 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3299 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3300 * packet must fill in the Verification Tag field of the outbound
3301 * packet with the Verification Tag received in the SHUTDOWN ACK and
Jerome Forissier047a2422005-04-28 11:58:43 -07003302 * set the T-bit in the Chunk Flags to indicate that the Verification
3303 * Tag is reflected.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003304 *
3305 * 8) The receiver should respond to the sender of the OOTB packet with
3306 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3307 * MUST fill in the Verification Tag field of the outbound packet
3308 * with the value found in the Verification Tag field of the OOTB
Jerome Forissier047a2422005-04-28 11:58:43 -07003309 * packet and set the T-bit in the Chunk Flags to indicate that the
3310 * Verification Tag is reflected. After sending this ABORT, the
3311 * receiver of the OOTB packet shall discard the OOTB packet and take
3312 * no further action.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003313 */
3314sctp_disposition_t sctp_sf_ootb(const struct sctp_endpoint *ep,
3315 const struct sctp_association *asoc,
3316 const sctp_subtype_t type,
3317 void *arg,
3318 sctp_cmd_seq_t *commands)
3319{
3320 struct sctp_chunk *chunk = arg;
3321 struct sk_buff *skb = chunk->skb;
3322 sctp_chunkhdr_t *ch;
3323 __u8 *ch_end;
3324 int ootb_shut_ack = 0;
3325
3326 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES);
3327
3328 ch = (sctp_chunkhdr_t *) chunk->chunk_hdr;
3329 do {
Vlad Yasevichece25df2007-09-07 16:30:54 -04003330 /* Report violation if the chunk is less then minimal */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003331 if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t))
Vlad Yasevichece25df2007-09-07 16:30:54 -04003332 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3333 commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003334
Vlad Yasevichece25df2007-09-07 16:30:54 -04003335 /* Now that we know we at least have a chunk header,
3336 * do things that are type appropriate.
3337 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003338 if (SCTP_CID_SHUTDOWN_ACK == ch->type)
3339 ootb_shut_ack = 1;
3340
3341 /* RFC 2960, Section 3.3.7
3342 * Moreover, under any circumstances, an endpoint that
3343 * receives an ABORT MUST NOT respond to that ABORT by
3344 * sending an ABORT of its own.
3345 */
3346 if (SCTP_CID_ABORT == ch->type)
3347 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003348
Vlad Yasevichece25df2007-09-07 16:30:54 -04003349 /* Report violation if chunk len overflows */
3350 ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
3351 if (ch_end > skb_tail_pointer(skb))
3352 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3353 commands);
3354
Linus Torvalds1da177e2005-04-16 15:20:36 -07003355 ch = (sctp_chunkhdr_t *) ch_end;
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07003356 } while (ch_end < skb_tail_pointer(skb));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003357
3358 if (ootb_shut_ack)
Vlad Yasevichd3f25962007-09-07 11:47:45 -04003359 return sctp_sf_shut_8_4_5(ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003360 else
Vlad Yasevichd3f25962007-09-07 11:47:45 -04003361 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003362}
3363
3364/*
3365 * Handle an "Out of the blue" SHUTDOWN ACK.
3366 *
Jerome Forissier047a2422005-04-28 11:58:43 -07003367 * Section: 8.4 5, sctpimpguide 2.41.
3368 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003369 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
Jerome Forissier047a2422005-04-28 11:58:43 -07003370 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3371 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3372 * packet must fill in the Verification Tag field of the outbound
3373 * packet with the Verification Tag received in the SHUTDOWN ACK and
3374 * set the T-bit in the Chunk Flags to indicate that the Verification
3375 * Tag is reflected.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003376 *
3377 * Inputs
3378 * (endpoint, asoc, type, arg, commands)
3379 *
3380 * Outputs
3381 * (sctp_disposition_t)
3382 *
3383 * The return value is the disposition of the chunk.
3384 */
3385static sctp_disposition_t sctp_sf_shut_8_4_5(const struct sctp_endpoint *ep,
3386 const struct sctp_association *asoc,
3387 const sctp_subtype_t type,
3388 void *arg,
3389 sctp_cmd_seq_t *commands)
3390{
3391 struct sctp_packet *packet = NULL;
3392 struct sctp_chunk *chunk = arg;
3393 struct sctp_chunk *shut;
3394
3395 packet = sctp_ootb_pkt_new(asoc, chunk);
3396
3397 if (packet) {
3398 /* Make an SHUTDOWN_COMPLETE.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003399 * The T bit will be set if the asoc is NULL.
3400 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003401 shut = sctp_make_shutdown_complete(asoc, chunk);
3402 if (!shut) {
3403 sctp_ootb_pkt_free(packet);
3404 return SCTP_DISPOSITION_NOMEM;
3405 }
3406
Jerome Forissier047a2422005-04-28 11:58:43 -07003407 /* Reflect vtag if T-Bit is set */
3408 if (sctp_test_T_bit(shut))
3409 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3410
Linus Torvalds1da177e2005-04-16 15:20:36 -07003411 /* Set the skb to the belonging sock for accounting. */
3412 shut->skb->sk = ep->base.sk;
3413
3414 sctp_packet_append_chunk(packet, shut);
3415
3416 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3417 SCTP_PACKET(packet));
3418
3419 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
3420
3421 /* If the chunk length is invalid, we don't want to process
3422 * the reset of the packet.
3423 */
3424 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3425 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3426
Vlad Yasevichd3f25962007-09-07 11:47:45 -04003427 /* We need to discard the rest of the packet to prevent
3428 * potential bomming attacks from additional bundled chunks.
3429 * This is documented in SCTP Threats ID.
3430 */
3431 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003432 }
3433
3434 return SCTP_DISPOSITION_NOMEM;
3435}
3436
3437/*
3438 * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state.
3439 *
3440 * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK
3441 * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the
3442 * procedures in section 8.4 SHOULD be followed, in other words it
3443 * should be treated as an Out Of The Blue packet.
3444 * [This means that we do NOT check the Verification Tag on these
3445 * chunks. --piggy ]
3446 *
3447 */
3448sctp_disposition_t sctp_sf_do_8_5_1_E_sa(const struct sctp_endpoint *ep,
3449 const struct sctp_association *asoc,
3450 const sctp_subtype_t type,
3451 void *arg,
3452 sctp_cmd_seq_t *commands)
3453{
Vlad Yasevichece25df2007-09-07 16:30:54 -04003454 struct sctp_chunk *chunk = arg;
3455
3456 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3457 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3458 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3459 commands);
3460
Linus Torvalds1da177e2005-04-16 15:20:36 -07003461 /* Although we do have an association in this case, it corresponds
3462 * to a restarted association. So the packet is treated as an OOTB
3463 * packet and the state function that handles OOTB SHUTDOWN_ACK is
3464 * called with a NULL association.
3465 */
Wei Yongjun8190f892008-09-08 12:13:55 +08003466 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES);
3467
Linus Torvalds1da177e2005-04-16 15:20:36 -07003468 return sctp_sf_shut_8_4_5(ep, NULL, type, arg, commands);
3469}
3470
3471/* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */
3472sctp_disposition_t sctp_sf_do_asconf(const struct sctp_endpoint *ep,
3473 const struct sctp_association *asoc,
3474 const sctp_subtype_t type, void *arg,
3475 sctp_cmd_seq_t *commands)
3476{
3477 struct sctp_chunk *chunk = arg;
3478 struct sctp_chunk *asconf_ack = NULL;
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003479 struct sctp_paramhdr *err_param = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003480 sctp_addiphdr_t *hdr;
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003481 union sctp_addr_param *addr_param;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003482 __u32 serial;
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003483 int length;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003484
3485 if (!sctp_vtag_verify(chunk, asoc)) {
3486 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3487 SCTP_NULL());
3488 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3489 }
3490
Vlad Yasevich6afd2e82007-12-20 14:08:04 -08003491 /* ADD-IP: Section 4.1.1
3492 * This chunk MUST be sent in an authenticated way by using
3493 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3494 * is received unauthenticated it MUST be silently discarded as
3495 * described in [I-D.ietf-tsvwg-sctp-auth].
3496 */
3497 if (!sctp_addip_noauth && !chunk->auth)
3498 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
3499
Linus Torvalds1da177e2005-04-16 15:20:36 -07003500 /* Make sure that the ASCONF ADDIP chunk has a valid length. */
3501 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_addip_chunk_t)))
3502 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3503 commands);
3504
3505 hdr = (sctp_addiphdr_t *)chunk->skb->data;
3506 serial = ntohl(hdr->serial);
3507
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003508 addr_param = (union sctp_addr_param *)hdr->params;
3509 length = ntohs(addr_param->p.length);
3510 if (length < sizeof(sctp_paramhdr_t))
Wei Yongjunba016672008-09-30 05:32:24 -07003511 return sctp_sf_violation_paramlen(ep, asoc, type, arg,
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003512 (void *)addr_param, commands);
3513
3514 /* Verify the ASCONF chunk before processing it. */
3515 if (!sctp_verify_asconf(asoc,
Vlad Yasevicha08de642007-12-20 14:11:47 -08003516 (sctp_paramhdr_t *)((void *)addr_param + length),
3517 (void *)chunk->chunk_end,
3518 &err_param))
Wei Yongjunba016672008-09-30 05:32:24 -07003519 return sctp_sf_violation_paramlen(ep, asoc, type, arg,
3520 (void *)err_param, commands);
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003521
Vlad Yasevicha08de642007-12-20 14:11:47 -08003522 /* ADDIP 5.2 E1) Compare the value of the serial number to the value
Linus Torvalds1da177e2005-04-16 15:20:36 -07003523 * the endpoint stored in a new association variable
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003524 * 'Peer-Serial-Number'.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003525 */
3526 if (serial == asoc->peer.addip_serial + 1) {
Vlad Yasevicha08de642007-12-20 14:11:47 -08003527 /* If this is the first instance of ASCONF in the packet,
3528 * we can clean our old ASCONF-ACKs.
3529 */
3530 if (!chunk->has_asconf)
3531 sctp_assoc_clean_asconf_ack_cache(asoc);
3532
3533 /* ADDIP 5.2 E4) When the Sequence Number matches the next one
3534 * expected, process the ASCONF as described below and after
3535 * processing the ASCONF Chunk, append an ASCONF-ACK Chunk to
3536 * the response packet and cache a copy of it (in the event it
3537 * later needs to be retransmitted).
3538 *
3539 * Essentially, do V1-V5.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003540 */
3541 asconf_ack = sctp_process_asconf((struct sctp_association *)
3542 asoc, chunk);
3543 if (!asconf_ack)
3544 return SCTP_DISPOSITION_NOMEM;
Vlad Yasevicha08de642007-12-20 14:11:47 -08003545 } else if (serial < asoc->peer.addip_serial + 1) {
3546 /* ADDIP 5.2 E2)
3547 * If the value found in the Sequence Number is less than the
3548 * ('Peer- Sequence-Number' + 1), simply skip to the next
3549 * ASCONF, and include in the outbound response packet
3550 * any previously cached ASCONF-ACK response that was
3551 * sent and saved that matches the Sequence Number of the
3552 * ASCONF. Note: It is possible that no cached ASCONF-ACK
3553 * Chunk exists. This will occur when an older ASCONF
3554 * arrives out of order. In such a case, the receiver
3555 * should skip the ASCONF Chunk and not include ASCONF-ACK
3556 * Chunk for that chunk.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003557 */
Vlad Yasevicha08de642007-12-20 14:11:47 -08003558 asconf_ack = sctp_assoc_lookup_asconf_ack(asoc, hdr->serial);
3559 if (!asconf_ack)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003560 return SCTP_DISPOSITION_DISCARD;
Vlad Yasevich31b02e12009-09-04 18:21:00 -04003561
3562 /* Reset the transport so that we select the correct one
3563 * this time around. This is to make sure that we don't
3564 * accidentally use a stale transport that's been removed.
3565 */
3566 asconf_ack->transport = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003567 } else {
Vlad Yasevicha08de642007-12-20 14:11:47 -08003568 /* ADDIP 5.2 E5) Otherwise, the ASCONF Chunk is discarded since
Linus Torvalds1da177e2005-04-16 15:20:36 -07003569 * it must be either a stale packet or from an attacker.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003570 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003571 return SCTP_DISPOSITION_DISCARD;
3572 }
3573
Vlad Yasevicha08de642007-12-20 14:11:47 -08003574 /* ADDIP 5.2 E6) The destination address of the SCTP packet
3575 * containing the ASCONF-ACK Chunks MUST be the source address of
3576 * the SCTP packet that held the ASCONF Chunks.
3577 *
3578 * To do this properly, we'll set the destination address of the chunk
3579 * and at the transmit time, will try look up the transport to use.
3580 * Since ASCONFs may be bundled, the correct transport may not be
Thadeu Lima de Souza Cascardo94e2bd62009-10-16 15:20:49 +02003581 * created until we process the entire packet, thus this workaround.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003582 */
Vlad Yasevicha08de642007-12-20 14:11:47 -08003583 asconf_ack->dest = chunk->source;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003584 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(asconf_ack));
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003585
Linus Torvalds1da177e2005-04-16 15:20:36 -07003586 return SCTP_DISPOSITION_CONSUME;
3587}
3588
3589/*
3590 * ADDIP Section 4.3 General rules for address manipulation
3591 * When building TLV parameters for the ASCONF Chunk that will add or
3592 * delete IP addresses the D0 to D13 rules should be applied:
3593 */
3594sctp_disposition_t sctp_sf_do_asconf_ack(const struct sctp_endpoint *ep,
3595 const struct sctp_association *asoc,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003596 const sctp_subtype_t type, void *arg,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003597 sctp_cmd_seq_t *commands)
3598{
3599 struct sctp_chunk *asconf_ack = arg;
3600 struct sctp_chunk *last_asconf = asoc->addip_last_asconf;
3601 struct sctp_chunk *abort;
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003602 struct sctp_paramhdr *err_param = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003603 sctp_addiphdr_t *addip_hdr;
3604 __u32 sent_serial, rcvd_serial;
3605
3606 if (!sctp_vtag_verify(asconf_ack, asoc)) {
3607 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3608 SCTP_NULL());
3609 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3610 }
3611
Vlad Yasevich6afd2e82007-12-20 14:08:04 -08003612 /* ADD-IP, Section 4.1.2:
3613 * This chunk MUST be sent in an authenticated way by using
3614 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3615 * is received unauthenticated it MUST be silently discarded as
3616 * described in [I-D.ietf-tsvwg-sctp-auth].
3617 */
3618 if (!sctp_addip_noauth && !asconf_ack->auth)
3619 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
3620
Linus Torvalds1da177e2005-04-16 15:20:36 -07003621 /* Make sure that the ADDIP chunk has a valid length. */
3622 if (!sctp_chunk_length_valid(asconf_ack, sizeof(sctp_addip_chunk_t)))
3623 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3624 commands);
3625
3626 addip_hdr = (sctp_addiphdr_t *)asconf_ack->skb->data;
3627 rcvd_serial = ntohl(addip_hdr->serial);
3628
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003629 /* Verify the ASCONF-ACK chunk before processing it. */
3630 if (!sctp_verify_asconf(asoc,
3631 (sctp_paramhdr_t *)addip_hdr->params,
3632 (void *)asconf_ack->chunk_end,
3633 &err_param))
Wei Yongjunba016672008-09-30 05:32:24 -07003634 return sctp_sf_violation_paramlen(ep, asoc, type, arg,
3635 (void *)err_param, commands);
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003636
Linus Torvalds1da177e2005-04-16 15:20:36 -07003637 if (last_asconf) {
3638 addip_hdr = (sctp_addiphdr_t *)last_asconf->subh.addip_hdr;
3639 sent_serial = ntohl(addip_hdr->serial);
3640 } else {
3641 sent_serial = asoc->addip_serial - 1;
3642 }
3643
3644 /* D0) If an endpoint receives an ASCONF-ACK that is greater than or
3645 * equal to the next serial number to be used but no ASCONF chunk is
3646 * outstanding the endpoint MUST ABORT the association. Note that a
3647 * sequence number is greater than if it is no more than 2^^31-1
3648 * larger than the current sequence number (using serial arithmetic).
3649 */
3650 if (ADDIP_SERIAL_gte(rcvd_serial, sent_serial + 1) &&
3651 !(asoc->addip_last_asconf)) {
3652 abort = sctp_make_abort(asoc, asconf_ack,
3653 sizeof(sctp_errhdr_t));
3654 if (abort) {
Wei Yongjun00f1c2d2007-08-21 15:50:01 +08003655 sctp_init_cause(abort, SCTP_ERROR_ASCONF_ACK, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003656 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3657 SCTP_CHUNK(abort));
3658 }
3659 /* We are going to ABORT, so we might as well stop
3660 * processing the rest of the chunks in the packet.
3661 */
3662 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3663 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3664 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07003665 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003666 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003667 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08003668 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003669 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
3670 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3671 return SCTP_DISPOSITION_ABORT;
3672 }
3673
3674 if ((rcvd_serial == sent_serial) && asoc->addip_last_asconf) {
3675 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3676 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3677
3678 if (!sctp_process_asconf_ack((struct sctp_association *)asoc,
Vlad Yasevichc0786692010-04-28 08:47:22 +00003679 asconf_ack)) {
3680 /* Successfully processed ASCONF_ACK. We can
3681 * release the next asconf if we have one.
3682 */
3683 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_NEXT_ASCONF,
3684 SCTP_NULL());
Linus Torvalds1da177e2005-04-16 15:20:36 -07003685 return SCTP_DISPOSITION_CONSUME;
Vlad Yasevichc0786692010-04-28 08:47:22 +00003686 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07003687
3688 abort = sctp_make_abort(asoc, asconf_ack,
3689 sizeof(sctp_errhdr_t));
3690 if (abort) {
Wei Yongjun00f1c2d2007-08-21 15:50:01 +08003691 sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003692 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3693 SCTP_CHUNK(abort));
3694 }
3695 /* We are going to ABORT, so we might as well stop
3696 * processing the rest of the chunks in the packet.
3697 */
3698 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07003699 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003700 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003701 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08003702 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003703 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
3704 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3705 return SCTP_DISPOSITION_ABORT;
3706 }
3707
3708 return SCTP_DISPOSITION_DISCARD;
3709}
3710
3711/*
3712 * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP
3713 *
3714 * When a FORWARD TSN chunk arrives, the data receiver MUST first update
3715 * its cumulative TSN point to the value carried in the FORWARD TSN
3716 * chunk, and then MUST further advance its cumulative TSN point locally
3717 * if possible.
3718 * After the above processing, the data receiver MUST stop reporting any
3719 * missing TSNs earlier than or equal to the new cumulative TSN point.
3720 *
3721 * Verification Tag: 8.5 Verification Tag [Normal verification]
3722 *
3723 * The return value is the disposition of the chunk.
3724 */
3725sctp_disposition_t sctp_sf_eat_fwd_tsn(const struct sctp_endpoint *ep,
3726 const struct sctp_association *asoc,
3727 const sctp_subtype_t type,
3728 void *arg,
3729 sctp_cmd_seq_t *commands)
3730{
3731 struct sctp_chunk *chunk = arg;
3732 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
Wei Yongjun9fcb95a2008-12-25 16:58:11 -08003733 struct sctp_fwdtsn_skip *skip;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003734 __u16 len;
3735 __u32 tsn;
3736
3737 if (!sctp_vtag_verify(chunk, asoc)) {
3738 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3739 SCTP_NULL());
3740 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3741 }
3742
3743 /* Make sure that the FORWARD_TSN chunk has valid length. */
3744 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
3745 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3746 commands);
3747
3748 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3749 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3750 len = ntohs(chunk->chunk_hdr->length);
3751 len -= sizeof(struct sctp_chunkhdr);
3752 skb_pull(chunk->skb, len);
3753
3754 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
Harvey Harrison0dc47872008-03-05 20:47:47 -08003755 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __func__, tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003756
3757 /* The TSN is too high--silently discard the chunk and count on it
3758 * getting retransmitted later.
3759 */
3760 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3761 goto discard_noforce;
3762
Wei Yongjun9fcb95a2008-12-25 16:58:11 -08003763 /* Silently discard the chunk if stream-id is not valid */
3764 sctp_walk_fwdtsn(skip, chunk) {
3765 if (ntohs(skip->stream) >= asoc->c.sinit_max_instreams)
3766 goto discard_noforce;
3767 }
3768
Linus Torvalds1da177e2005-04-16 15:20:36 -07003769 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3770 if (len > sizeof(struct sctp_fwdtsn_hdr))
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003771 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003772 SCTP_CHUNK(chunk));
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003773
Linus Torvalds1da177e2005-04-16 15:20:36 -07003774 /* Count this as receiving DATA. */
3775 if (asoc->autoclose) {
3776 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3777 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
3778 }
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003779
Linus Torvalds1da177e2005-04-16 15:20:36 -07003780 /* FIXME: For now send a SACK, but DATA processing may
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003781 * send another.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003782 */
3783 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
Linus Torvalds1da177e2005-04-16 15:20:36 -07003784
3785 return SCTP_DISPOSITION_CONSUME;
3786
3787discard_noforce:
3788 return SCTP_DISPOSITION_DISCARD;
3789}
3790
3791sctp_disposition_t sctp_sf_eat_fwd_tsn_fast(
3792 const struct sctp_endpoint *ep,
3793 const struct sctp_association *asoc,
3794 const sctp_subtype_t type,
3795 void *arg,
3796 sctp_cmd_seq_t *commands)
3797{
3798 struct sctp_chunk *chunk = arg;
3799 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
Wei Yongjun9fcb95a2008-12-25 16:58:11 -08003800 struct sctp_fwdtsn_skip *skip;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003801 __u16 len;
3802 __u32 tsn;
3803
3804 if (!sctp_vtag_verify(chunk, asoc)) {
3805 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3806 SCTP_NULL());
3807 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3808 }
3809
3810 /* Make sure that the FORWARD_TSN chunk has a valid length. */
3811 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
3812 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3813 commands);
3814
3815 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3816 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3817 len = ntohs(chunk->chunk_hdr->length);
3818 len -= sizeof(struct sctp_chunkhdr);
3819 skb_pull(chunk->skb, len);
3820
3821 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
Harvey Harrison0dc47872008-03-05 20:47:47 -08003822 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __func__, tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003823
3824 /* The TSN is too high--silently discard the chunk and count on it
3825 * getting retransmitted later.
3826 */
3827 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3828 goto gen_shutdown;
3829
Wei Yongjun9fcb95a2008-12-25 16:58:11 -08003830 /* Silently discard the chunk if stream-id is not valid */
3831 sctp_walk_fwdtsn(skip, chunk) {
3832 if (ntohs(skip->stream) >= asoc->c.sinit_max_instreams)
3833 goto gen_shutdown;
3834 }
3835
Linus Torvalds1da177e2005-04-16 15:20:36 -07003836 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3837 if (len > sizeof(struct sctp_fwdtsn_hdr))
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003838 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003839 SCTP_CHUNK(chunk));
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003840
Linus Torvalds1da177e2005-04-16 15:20:36 -07003841 /* Go a head and force a SACK, since we are shutting down. */
3842gen_shutdown:
3843 /* Implementor's Guide.
3844 *
3845 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3846 * respond to each received packet containing one or more DATA chunk(s)
3847 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3848 */
3849 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
3850 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3851 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3852 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3853
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003854 return SCTP_DISPOSITION_CONSUME;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003855}
3856
3857/*
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07003858 * SCTP-AUTH Section 6.3 Receving authenticated chukns
3859 *
3860 * The receiver MUST use the HMAC algorithm indicated in the HMAC
3861 * Identifier field. If this algorithm was not specified by the
3862 * receiver in the HMAC-ALGO parameter in the INIT or INIT-ACK chunk
3863 * during association setup, the AUTH chunk and all chunks after it MUST
3864 * be discarded and an ERROR chunk SHOULD be sent with the error cause
3865 * defined in Section 4.1.
3866 *
3867 * If an endpoint with no shared key receives a Shared Key Identifier
3868 * other than 0, it MUST silently discard all authenticated chunks. If
3869 * the endpoint has at least one endpoint pair shared key for the peer,
3870 * it MUST use the key specified by the Shared Key Identifier if a
3871 * key has been configured for that Shared Key Identifier. If no
3872 * endpoint pair shared key has been configured for that Shared Key
3873 * Identifier, all authenticated chunks MUST be silently discarded.
3874 *
3875 * Verification Tag: 8.5 Verification Tag [Normal verification]
3876 *
3877 * The return value is the disposition of the chunk.
3878 */
3879static sctp_ierror_t sctp_sf_authenticate(const struct sctp_endpoint *ep,
3880 const struct sctp_association *asoc,
3881 const sctp_subtype_t type,
3882 struct sctp_chunk *chunk)
3883{
3884 struct sctp_authhdr *auth_hdr;
3885 struct sctp_hmac *hmac;
3886 unsigned int sig_len;
3887 __u16 key_id;
3888 __u8 *save_digest;
3889 __u8 *digest;
3890
3891 /* Pull in the auth header, so we can do some more verification */
3892 auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
3893 chunk->subh.auth_hdr = auth_hdr;
3894 skb_pull(chunk->skb, sizeof(struct sctp_authhdr));
3895
3896 /* Make sure that we suport the HMAC algorithm from the auth
3897 * chunk.
3898 */
3899 if (!sctp_auth_asoc_verify_hmac_id(asoc, auth_hdr->hmac_id))
3900 return SCTP_IERROR_AUTH_BAD_HMAC;
3901
3902 /* Make sure that the provided shared key identifier has been
3903 * configured
3904 */
3905 key_id = ntohs(auth_hdr->shkey_id);
3906 if (key_id != asoc->active_key_id && !sctp_auth_get_shkey(asoc, key_id))
3907 return SCTP_IERROR_AUTH_BAD_KEYID;
3908
3909
3910 /* Make sure that the length of the signature matches what
3911 * we expect.
3912 */
3913 sig_len = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_auth_chunk_t);
3914 hmac = sctp_auth_get_hmac(ntohs(auth_hdr->hmac_id));
3915 if (sig_len != hmac->hmac_len)
3916 return SCTP_IERROR_PROTO_VIOLATION;
3917
3918 /* Now that we've done validation checks, we can compute and
3919 * verify the hmac. The steps involved are:
3920 * 1. Save the digest from the chunk.
3921 * 2. Zero out the digest in the chunk.
3922 * 3. Compute the new digest
3923 * 4. Compare saved and new digests.
3924 */
3925 digest = auth_hdr->hmac;
3926 skb_pull(chunk->skb, sig_len);
3927
3928 save_digest = kmemdup(digest, sig_len, GFP_ATOMIC);
3929 if (!save_digest)
3930 goto nomem;
3931
3932 memset(digest, 0, sig_len);
3933
3934 sctp_auth_calculate_hmac(asoc, chunk->skb,
3935 (struct sctp_auth_chunk *)chunk->chunk_hdr,
3936 GFP_ATOMIC);
3937
3938 /* Discard the packet if the digests do not match */
3939 if (memcmp(save_digest, digest, sig_len)) {
3940 kfree(save_digest);
3941 return SCTP_IERROR_BAD_SIG;
3942 }
3943
3944 kfree(save_digest);
3945 chunk->auth = 1;
3946
3947 return SCTP_IERROR_NO_ERROR;
3948nomem:
3949 return SCTP_IERROR_NOMEM;
3950}
3951
3952sctp_disposition_t sctp_sf_eat_auth(const struct sctp_endpoint *ep,
3953 const struct sctp_association *asoc,
3954 const sctp_subtype_t type,
3955 void *arg,
3956 sctp_cmd_seq_t *commands)
3957{
3958 struct sctp_authhdr *auth_hdr;
3959 struct sctp_chunk *chunk = arg;
3960 struct sctp_chunk *err_chunk;
3961 sctp_ierror_t error;
3962
Wei Yongjund2f19fa2008-02-05 03:02:26 -08003963 /* Make sure that the peer has AUTH capable */
3964 if (!asoc->peer.auth_capable)
3965 return sctp_sf_unk_chunk(ep, asoc, type, arg, commands);
3966
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07003967 if (!sctp_vtag_verify(chunk, asoc)) {
3968 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3969 SCTP_NULL());
3970 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3971 }
3972
3973 /* Make sure that the AUTH chunk has valid length. */
3974 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_auth_chunk)))
3975 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3976 commands);
3977
3978 auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
3979 error = sctp_sf_authenticate(ep, asoc, type, chunk);
3980 switch (error) {
3981 case SCTP_IERROR_AUTH_BAD_HMAC:
3982 /* Generate the ERROR chunk and discard the rest
3983 * of the packet
3984 */
3985 err_chunk = sctp_make_op_error(asoc, chunk,
3986 SCTP_ERROR_UNSUP_HMAC,
3987 &auth_hdr->hmac_id,
Vlad Yasevich6383cfb2009-11-23 15:53:56 -05003988 sizeof(__u16), 0);
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07003989 if (err_chunk) {
3990 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3991 SCTP_CHUNK(err_chunk));
3992 }
3993 /* Fall Through */
3994 case SCTP_IERROR_AUTH_BAD_KEYID:
3995 case SCTP_IERROR_BAD_SIG:
3996 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3997 break;
3998 case SCTP_IERROR_PROTO_VIOLATION:
3999 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
4000 commands);
4001 break;
4002 case SCTP_IERROR_NOMEM:
4003 return SCTP_DISPOSITION_NOMEM;
4004 default:
4005 break;
4006 }
4007
Vlad Yasevich65b07e52007-09-16 19:34:00 -07004008 if (asoc->active_key_id != ntohs(auth_hdr->shkey_id)) {
4009 struct sctp_ulpevent *ev;
4010
4011 ev = sctp_ulpevent_make_authkey(asoc, ntohs(auth_hdr->shkey_id),
4012 SCTP_AUTH_NEWKEY, GFP_ATOMIC);
4013
4014 if (!ev)
4015 return -ENOMEM;
4016
4017 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
4018 SCTP_ULPEVENT(ev));
4019 }
4020
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07004021 return SCTP_DISPOSITION_CONSUME;
4022}
4023
4024/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07004025 * Process an unknown chunk.
4026 *
4027 * Section: 3.2. Also, 2.1 in the implementor's guide.
4028 *
4029 * Chunk Types are encoded such that the highest-order two bits specify
4030 * the action that must be taken if the processing endpoint does not
4031 * recognize the Chunk Type.
4032 *
4033 * 00 - Stop processing this SCTP packet and discard it, do not process
4034 * any further chunks within it.
4035 *
4036 * 01 - Stop processing this SCTP packet and discard it, do not process
4037 * any further chunks within it, and report the unrecognized
4038 * chunk in an 'Unrecognized Chunk Type'.
4039 *
4040 * 10 - Skip this chunk and continue processing.
4041 *
4042 * 11 - Skip this chunk and continue processing, but report in an ERROR
4043 * Chunk using the 'Unrecognized Chunk Type' cause of error.
4044 *
4045 * The return value is the disposition of the chunk.
4046 */
4047sctp_disposition_t sctp_sf_unk_chunk(const struct sctp_endpoint *ep,
4048 const struct sctp_association *asoc,
4049 const sctp_subtype_t type,
4050 void *arg,
4051 sctp_cmd_seq_t *commands)
4052{
4053 struct sctp_chunk *unk_chunk = arg;
4054 struct sctp_chunk *err_chunk;
4055 sctp_chunkhdr_t *hdr;
4056
4057 SCTP_DEBUG_PRINTK("Processing the unknown chunk id %d.\n", type.chunk);
4058
4059 if (!sctp_vtag_verify(unk_chunk, asoc))
4060 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
4061
4062 /* Make sure that the chunk has a valid length.
4063 * Since we don't know the chunk type, we use a general
4064 * chunkhdr structure to make a comparison.
4065 */
4066 if (!sctp_chunk_length_valid(unk_chunk, sizeof(sctp_chunkhdr_t)))
4067 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
4068 commands);
4069
4070 switch (type.chunk & SCTP_CID_ACTION_MASK) {
4071 case SCTP_CID_ACTION_DISCARD:
4072 /* Discard the packet. */
4073 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
4074 break;
4075 case SCTP_CID_ACTION_DISCARD_ERR:
Linus Torvalds1da177e2005-04-16 15:20:36 -07004076 /* Generate an ERROR chunk as response. */
4077 hdr = unk_chunk->chunk_hdr;
4078 err_chunk = sctp_make_op_error(asoc, unk_chunk,
4079 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
Vlad Yasevich6383cfb2009-11-23 15:53:56 -05004080 WORD_ROUND(ntohs(hdr->length)),
4081 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004082 if (err_chunk) {
4083 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4084 SCTP_CHUNK(err_chunk));
4085 }
Vlad Yasevich2e3216c2008-06-19 16:08:18 -07004086
4087 /* Discard the packet. */
4088 sctp_sf_pdiscard(ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004089 return SCTP_DISPOSITION_CONSUME;
4090 break;
4091 case SCTP_CID_ACTION_SKIP:
4092 /* Skip the chunk. */
4093 return SCTP_DISPOSITION_DISCARD;
4094 break;
4095 case SCTP_CID_ACTION_SKIP_ERR:
4096 /* Generate an ERROR chunk as response. */
4097 hdr = unk_chunk->chunk_hdr;
4098 err_chunk = sctp_make_op_error(asoc, unk_chunk,
4099 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
Vlad Yasevich6383cfb2009-11-23 15:53:56 -05004100 WORD_ROUND(ntohs(hdr->length)),
4101 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004102 if (err_chunk) {
4103 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4104 SCTP_CHUNK(err_chunk));
4105 }
4106 /* Skip the chunk. */
4107 return SCTP_DISPOSITION_CONSUME;
4108 break;
4109 default:
4110 break;
4111 }
4112
4113 return SCTP_DISPOSITION_DISCARD;
4114}
4115
4116/*
4117 * Discard the chunk.
4118 *
4119 * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2
4120 * [Too numerous to mention...]
4121 * Verification Tag: No verification needed.
4122 * Inputs
4123 * (endpoint, asoc, chunk)
4124 *
4125 * Outputs
4126 * (asoc, reply_msg, msg_up, timers, counters)
4127 *
4128 * The return value is the disposition of the chunk.
4129 */
4130sctp_disposition_t sctp_sf_discard_chunk(const struct sctp_endpoint *ep,
4131 const struct sctp_association *asoc,
4132 const sctp_subtype_t type,
4133 void *arg,
4134 sctp_cmd_seq_t *commands)
4135{
Vlad Yasevichece25df2007-09-07 16:30:54 -04004136 struct sctp_chunk *chunk = arg;
4137
4138 /* Make sure that the chunk has a valid length.
4139 * Since we don't know the chunk type, we use a general
4140 * chunkhdr structure to make a comparison.
4141 */
4142 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
4143 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
4144 commands);
4145
Linus Torvalds1da177e2005-04-16 15:20:36 -07004146 SCTP_DEBUG_PRINTK("Chunk %d is discarded\n", type.chunk);
4147 return SCTP_DISPOSITION_DISCARD;
4148}
4149
4150/*
4151 * Discard the whole packet.
4152 *
4153 * Section: 8.4 2)
4154 *
4155 * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST
4156 * silently discard the OOTB packet and take no further action.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004157 *
4158 * Verification Tag: No verification necessary
4159 *
4160 * Inputs
4161 * (endpoint, asoc, chunk)
4162 *
4163 * Outputs
4164 * (asoc, reply_msg, msg_up, timers, counters)
4165 *
4166 * The return value is the disposition of the chunk.
4167 */
4168sctp_disposition_t sctp_sf_pdiscard(const struct sctp_endpoint *ep,
4169 const struct sctp_association *asoc,
4170 const sctp_subtype_t type,
4171 void *arg,
4172 sctp_cmd_seq_t *commands)
4173{
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07004174 SCTP_INC_STATS(SCTP_MIB_IN_PKT_DISCARDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004175 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
4176
4177 return SCTP_DISPOSITION_CONSUME;
4178}
4179
4180
4181/*
4182 * The other end is violating protocol.
4183 *
4184 * Section: Not specified
4185 * Verification Tag: Not specified
4186 * Inputs
4187 * (endpoint, asoc, chunk)
4188 *
4189 * Outputs
4190 * (asoc, reply_msg, msg_up, timers, counters)
4191 *
4192 * We simply tag the chunk as a violation. The state machine will log
4193 * the violation and continue.
4194 */
4195sctp_disposition_t sctp_sf_violation(const struct sctp_endpoint *ep,
4196 const struct sctp_association *asoc,
4197 const sctp_subtype_t type,
4198 void *arg,
4199 sctp_cmd_seq_t *commands)
4200{
Vlad Yasevichece25df2007-09-07 16:30:54 -04004201 struct sctp_chunk *chunk = arg;
4202
4203 /* Make sure that the chunk has a valid length. */
4204 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
4205 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
4206 commands);
4207
Linus Torvalds1da177e2005-04-16 15:20:36 -07004208 return SCTP_DISPOSITION_VIOLATION;
4209}
4210
Linus Torvalds1da177e2005-04-16 15:20:36 -07004211/*
Wei Yongjunaecedea2007-08-02 16:57:44 +08004212 * Common function to handle a protocol violation.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004213 */
Wei Yongjunaecedea2007-08-02 16:57:44 +08004214static sctp_disposition_t sctp_sf_abort_violation(
Vlad Yasevichece25df2007-09-07 16:30:54 -04004215 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07004216 const struct sctp_association *asoc,
Linus Torvalds1da177e2005-04-16 15:20:36 -07004217 void *arg,
Wei Yongjunaecedea2007-08-02 16:57:44 +08004218 sctp_cmd_seq_t *commands,
4219 const __u8 *payload,
4220 const size_t paylen)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004221{
Vlad Yasevichece25df2007-09-07 16:30:54 -04004222 struct sctp_packet *packet = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004223 struct sctp_chunk *chunk = arg;
4224 struct sctp_chunk *abort = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004225
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07004226 /* SCTP-AUTH, Section 6.3:
4227 * It should be noted that if the receiver wants to tear
4228 * down an association in an authenticated way only, the
4229 * handling of malformed packets should not result in
4230 * tearing down the association.
4231 *
4232 * This means that if we only want to abort associations
4233 * in an authenticated way (i.e AUTH+ABORT), then we
Oliver Pinterac461a02008-02-03 17:52:41 +02004234 * can't destroy this association just becuase the packet
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07004235 * was malformed.
4236 */
4237 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
4238 goto discard;
4239
Jesper Juhl9abed242007-11-11 23:57:49 +01004240 /* Make the abort chunk. */
4241 abort = sctp_make_abort_violation(asoc, chunk, payload, paylen);
4242 if (!abort)
4243 goto nomem;
4244
Vlad Yasevichece25df2007-09-07 16:30:54 -04004245 if (asoc) {
Gui Jianfengf4ad85c2008-04-12 18:39:34 -07004246 /* Treat INIT-ACK as a special case during COOKIE-WAIT. */
4247 if (chunk->chunk_hdr->type == SCTP_CID_INIT_ACK &&
4248 !asoc->peer.i.init_tag) {
4249 sctp_initack_chunk_t *initack;
4250
4251 initack = (sctp_initack_chunk_t *)chunk->chunk_hdr;
4252 if (!sctp_chunk_length_valid(chunk,
4253 sizeof(sctp_initack_chunk_t)))
4254 abort->chunk_hdr->flags |= SCTP_CHUNK_FLAG_T;
4255 else {
4256 unsigned int inittag;
4257
4258 inittag = ntohl(initack->init_hdr.init_tag);
4259 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_INITTAG,
4260 SCTP_U32(inittag));
4261 }
4262 }
4263
Vlad Yasevichece25df2007-09-07 16:30:54 -04004264 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4265 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004266
Vlad Yasevichece25df2007-09-07 16:30:54 -04004267 if (asoc->state <= SCTP_STATE_COOKIE_ECHOED) {
4268 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4269 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4270 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4271 SCTP_ERROR(ECONNREFUSED));
4272 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
4273 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4274 } else {
4275 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4276 SCTP_ERROR(ECONNABORTED));
4277 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4278 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4279 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
4280 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07004281 } else {
Vlad Yasevichece25df2007-09-07 16:30:54 -04004282 packet = sctp_ootb_pkt_new(asoc, chunk);
4283
4284 if (!packet)
4285 goto nomem_pkt;
4286
4287 if (sctp_test_T_bit(abort))
4288 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
4289
4290 abort->skb->sk = ep->base.sk;
4291
4292 sctp_packet_append_chunk(packet, abort);
4293
4294 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
4295 SCTP_PACKET(packet));
4296
4297 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004298 }
4299
Linus Torvalds1da177e2005-04-16 15:20:36 -07004300 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09004301
Vlad Yasevich56eb82b2008-10-09 14:33:01 -07004302discard:
4303 sctp_sf_pdiscard(ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004304 return SCTP_DISPOSITION_ABORT;
4305
Vlad Yasevichece25df2007-09-07 16:30:54 -04004306nomem_pkt:
4307 sctp_chunk_free(abort);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004308nomem:
4309 return SCTP_DISPOSITION_NOMEM;
4310}
4311
Wei Yongjunaecedea2007-08-02 16:57:44 +08004312/*
4313 * Handle a protocol violation when the chunk length is invalid.
Frederik Schwarzer025dfda2008-10-16 19:02:37 +02004314 * "Invalid" length is identified as smaller than the minimal length a
Wei Yongjunaecedea2007-08-02 16:57:44 +08004315 * given chunk can be. For example, a SACK chunk has invalid length
Frederik Schwarzer025dfda2008-10-16 19:02:37 +02004316 * if its length is set to be smaller than the size of sctp_sack_chunk_t.
Wei Yongjunaecedea2007-08-02 16:57:44 +08004317 *
4318 * We inform the other end by sending an ABORT with a Protocol Violation
4319 * error code.
4320 *
4321 * Section: Not specified
4322 * Verification Tag: Nothing to do
4323 * Inputs
4324 * (endpoint, asoc, chunk)
4325 *
4326 * Outputs
4327 * (reply_msg, msg_up, counters)
4328 *
4329 * Generate an ABORT chunk and terminate the association.
4330 */
4331static sctp_disposition_t sctp_sf_violation_chunklen(
4332 const struct sctp_endpoint *ep,
4333 const struct sctp_association *asoc,
4334 const sctp_subtype_t type,
4335 void *arg,
4336 sctp_cmd_seq_t *commands)
4337{
Florian Westphal24448442008-03-23 22:46:34 -07004338 static const char err_str[]="The following chunk had invalid length:";
Wei Yongjunaecedea2007-08-02 16:57:44 +08004339
Vlad Yasevichece25df2007-09-07 16:30:54 -04004340 return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
Wei Yongjunaecedea2007-08-02 16:57:44 +08004341 sizeof(err_str));
4342}
4343
Wei Yongjun6f4c6182007-09-19 17:19:52 +08004344/*
4345 * Handle a protocol violation when the parameter length is invalid.
Frederik Schwarzer025dfda2008-10-16 19:02:37 +02004346 * "Invalid" length is identified as smaller than the minimal length a
Wei Yongjun6f4c6182007-09-19 17:19:52 +08004347 * given parameter can be.
4348 */
4349static sctp_disposition_t sctp_sf_violation_paramlen(
4350 const struct sctp_endpoint *ep,
4351 const struct sctp_association *asoc,
4352 const sctp_subtype_t type,
Wei Yongjunba016672008-09-30 05:32:24 -07004353 void *arg, void *ext,
4354 sctp_cmd_seq_t *commands)
4355{
4356 struct sctp_chunk *chunk = arg;
4357 struct sctp_paramhdr *param = ext;
4358 struct sctp_chunk *abort = NULL;
Wei Yongjun6f4c6182007-09-19 17:19:52 +08004359
Wei Yongjunba016672008-09-30 05:32:24 -07004360 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
4361 goto discard;
4362
4363 /* Make the abort chunk. */
4364 abort = sctp_make_violation_paramlen(asoc, chunk, param);
4365 if (!abort)
4366 goto nomem;
4367
4368 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4369 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
4370
4371 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4372 SCTP_ERROR(ECONNABORTED));
4373 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4374 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4375 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
Vlad Yasevich56eb82b2008-10-09 14:33:01 -07004376 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
Wei Yongjunba016672008-09-30 05:32:24 -07004377
4378discard:
4379 sctp_sf_pdiscard(ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
Wei Yongjunba016672008-09-30 05:32:24 -07004380 return SCTP_DISPOSITION_ABORT;
4381nomem:
4382 return SCTP_DISPOSITION_NOMEM;
Wei Yongjun6f4c6182007-09-19 17:19:52 +08004383}
4384
Wei Yongjunaecedea2007-08-02 16:57:44 +08004385/* Handle a protocol violation when the peer trying to advance the
4386 * cumulative tsn ack to a point beyond the max tsn currently sent.
4387 *
4388 * We inform the other end by sending an ABORT with a Protocol Violation
4389 * error code.
4390 */
4391static sctp_disposition_t sctp_sf_violation_ctsn(
4392 const struct sctp_endpoint *ep,
4393 const struct sctp_association *asoc,
4394 const sctp_subtype_t type,
4395 void *arg,
4396 sctp_cmd_seq_t *commands)
4397{
Florian Westphal24448442008-03-23 22:46:34 -07004398 static const char err_str[]="The cumulative tsn ack beyond the max tsn currently sent:";
Wei Yongjunaecedea2007-08-02 16:57:44 +08004399
Vlad Yasevichece25df2007-09-07 16:30:54 -04004400 return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
Wei Yongjunaecedea2007-08-02 16:57:44 +08004401 sizeof(err_str));
4402}
4403
Vlad Yasevichece25df2007-09-07 16:30:54 -04004404/* Handle protocol violation of an invalid chunk bundling. For example,
4405 * when we have an association and we recieve bundled INIT-ACK, or
4406 * SHUDOWN-COMPLETE, our peer is clearly violationg the "MUST NOT bundle"
4407 * statement from the specs. Additinally, there might be an attacker
4408 * on the path and we may not want to continue this communication.
4409 */
4410static sctp_disposition_t sctp_sf_violation_chunk(
4411 const struct sctp_endpoint *ep,
4412 const struct sctp_association *asoc,
4413 const sctp_subtype_t type,
4414 void *arg,
4415 sctp_cmd_seq_t *commands)
4416{
Florian Westphal24448442008-03-23 22:46:34 -07004417 static const char err_str[]="The following chunk violates protocol:";
Vlad Yasevichece25df2007-09-07 16:30:54 -04004418
4419 if (!asoc)
4420 return sctp_sf_violation(ep, asoc, type, arg, commands);
4421
4422 return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
4423 sizeof(err_str));
4424}
Linus Torvalds1da177e2005-04-16 15:20:36 -07004425/***************************************************************************
4426 * These are the state functions for handling primitive (Section 10) events.
4427 ***************************************************************************/
4428/*
4429 * sctp_sf_do_prm_asoc
4430 *
4431 * Section: 10.1 ULP-to-SCTP
4432 * B) Associate
4433 *
4434 * Format: ASSOCIATE(local SCTP instance name, destination transport addr,
4435 * outbound stream count)
4436 * -> association id [,destination transport addr list] [,outbound stream
4437 * count]
4438 *
4439 * This primitive allows the upper layer to initiate an association to a
4440 * specific peer endpoint.
4441 *
4442 * The peer endpoint shall be specified by one of the transport addresses
4443 * which defines the endpoint (see Section 1.4). If the local SCTP
4444 * instance has not been initialized, the ASSOCIATE is considered an
4445 * error.
4446 * [This is not relevant for the kernel implementation since we do all
4447 * initialization at boot time. It we hadn't initialized we wouldn't
4448 * get anywhere near this code.]
4449 *
4450 * An association id, which is a local handle to the SCTP association,
4451 * will be returned on successful establishment of the association. If
4452 * SCTP is not able to open an SCTP association with the peer endpoint,
4453 * an error is returned.
4454 * [In the kernel implementation, the struct sctp_association needs to
4455 * be created BEFORE causing this primitive to run.]
4456 *
4457 * Other association parameters may be returned, including the
4458 * complete destination transport addresses of the peer as well as the
4459 * outbound stream count of the local endpoint. One of the transport
4460 * address from the returned destination addresses will be selected by
4461 * the local endpoint as default primary path for sending SCTP packets
4462 * to this peer. The returned "destination transport addr list" can
4463 * be used by the ULP to change the default primary path or to force
4464 * sending a packet to a specific transport address. [All of this
4465 * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING
4466 * function.]
4467 *
4468 * Mandatory attributes:
4469 *
4470 * o local SCTP instance name - obtained from the INITIALIZE operation.
4471 * [This is the argument asoc.]
4472 * o destination transport addr - specified as one of the transport
4473 * addresses of the peer endpoint with which the association is to be
4474 * established.
4475 * [This is asoc->peer.active_path.]
4476 * o outbound stream count - the number of outbound streams the ULP
4477 * would like to open towards this peer endpoint.
4478 * [BUG: This is not currently implemented.]
4479 * Optional attributes:
4480 *
4481 * None.
4482 *
4483 * The return value is a disposition.
4484 */
4485sctp_disposition_t sctp_sf_do_prm_asoc(const struct sctp_endpoint *ep,
4486 const struct sctp_association *asoc,
4487 const sctp_subtype_t type,
4488 void *arg,
4489 sctp_cmd_seq_t *commands)
4490{
4491 struct sctp_chunk *repl;
Vlad Yasevichab38fb02008-04-12 18:40:06 -07004492 struct sctp_association* my_asoc;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004493
4494 /* The comment below says that we enter COOKIE-WAIT AFTER
4495 * sending the INIT, but that doesn't actually work in our
4496 * implementation...
4497 */
4498 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4499 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
4500
4501 /* RFC 2960 5.1 Normal Establishment of an Association
4502 *
4503 * A) "A" first sends an INIT chunk to "Z". In the INIT, "A"
4504 * must provide its Verification Tag (Tag_A) in the Initiate
4505 * Tag field. Tag_A SHOULD be a random number in the range of
4506 * 1 to 4294967295 (see 5.3.1 for Tag value selection). ...
4507 */
4508
4509 repl = sctp_make_init(asoc, &asoc->base.bind_addr, GFP_ATOMIC, 0);
4510 if (!repl)
4511 goto nomem;
4512
4513 /* Cast away the const modifier, as we want to just
4514 * rerun it through as a sideffect.
4515 */
Vlad Yasevichab38fb02008-04-12 18:40:06 -07004516 my_asoc = (struct sctp_association *)asoc;
4517 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(my_asoc));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004518
Frank Filz3f7a87d2005-06-20 13:14:57 -07004519 /* Choose transport for INIT. */
4520 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
4521 SCTP_CHUNK(repl));
4522
Linus Torvalds1da177e2005-04-16 15:20:36 -07004523 /* After sending the INIT, "A" starts the T1-init timer and
4524 * enters the COOKIE-WAIT state.
4525 */
4526 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4527 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4528 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
4529 return SCTP_DISPOSITION_CONSUME;
4530
4531nomem:
4532 return SCTP_DISPOSITION_NOMEM;
4533}
4534
4535/*
4536 * Process the SEND primitive.
4537 *
4538 * Section: 10.1 ULP-to-SCTP
4539 * E) Send
4540 *
4541 * Format: SEND(association id, buffer address, byte count [,context]
4542 * [,stream id] [,life time] [,destination transport address]
4543 * [,unorder flag] [,no-bundle flag] [,payload protocol-id] )
4544 * -> result
4545 *
4546 * This is the main method to send user data via SCTP.
4547 *
4548 * Mandatory attributes:
4549 *
4550 * o association id - local handle to the SCTP association
4551 *
4552 * o buffer address - the location where the user message to be
4553 * transmitted is stored;
4554 *
4555 * o byte count - The size of the user data in number of bytes;
4556 *
4557 * Optional attributes:
4558 *
4559 * o context - an optional 32 bit integer that will be carried in the
4560 * sending failure notification to the ULP if the transportation of
4561 * this User Message fails.
4562 *
4563 * o stream id - to indicate which stream to send the data on. If not
4564 * specified, stream 0 will be used.
4565 *
4566 * o life time - specifies the life time of the user data. The user data
4567 * will not be sent by SCTP after the life time expires. This
4568 * parameter can be used to avoid efforts to transmit stale
4569 * user messages. SCTP notifies the ULP if the data cannot be
4570 * initiated to transport (i.e. sent to the destination via SCTP's
4571 * send primitive) within the life time variable. However, the
4572 * user data will be transmitted if SCTP has attempted to transmit a
4573 * chunk before the life time expired.
4574 *
4575 * o destination transport address - specified as one of the destination
4576 * transport addresses of the peer endpoint to which this packet
4577 * should be sent. Whenever possible, SCTP should use this destination
4578 * transport address for sending the packets, instead of the current
4579 * primary path.
4580 *
4581 * o unorder flag - this flag, if present, indicates that the user
4582 * would like the data delivered in an unordered fashion to the peer
4583 * (i.e., the U flag is set to 1 on all DATA chunks carrying this
4584 * message).
4585 *
4586 * o no-bundle flag - instructs SCTP not to bundle this user data with
4587 * other outbound DATA chunks. SCTP MAY still bundle even when
4588 * this flag is present, when faced with network congestion.
4589 *
4590 * o payload protocol-id - A 32 bit unsigned integer that is to be
4591 * passed to the peer indicating the type of payload protocol data
4592 * being transmitted. This value is passed as opaque data by SCTP.
4593 *
4594 * The return value is the disposition.
4595 */
4596sctp_disposition_t sctp_sf_do_prm_send(const struct sctp_endpoint *ep,
4597 const struct sctp_association *asoc,
4598 const sctp_subtype_t type,
4599 void *arg,
4600 sctp_cmd_seq_t *commands)
4601{
Vlad Yasevich9c5c62b2009-08-10 13:51:03 -04004602 struct sctp_datamsg *msg = arg;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004603
Vlad Yasevich9c5c62b2009-08-10 13:51:03 -04004604 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_MSG, SCTP_DATAMSG(msg));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004605 return SCTP_DISPOSITION_CONSUME;
4606}
4607
4608/*
4609 * Process the SHUTDOWN primitive.
4610 *
4611 * Section: 10.1:
4612 * C) Shutdown
4613 *
4614 * Format: SHUTDOWN(association id)
4615 * -> result
4616 *
4617 * Gracefully closes an association. Any locally queued user data
4618 * will be delivered to the peer. The association will be terminated only
4619 * after the peer acknowledges all the SCTP packets sent. A success code
4620 * will be returned on successful termination of the association. If
4621 * attempting to terminate the association results in a failure, an error
4622 * code shall be returned.
4623 *
4624 * Mandatory attributes:
4625 *
4626 * o association id - local handle to the SCTP association
4627 *
4628 * Optional attributes:
4629 *
4630 * None.
4631 *
4632 * The return value is the disposition.
4633 */
4634sctp_disposition_t sctp_sf_do_9_2_prm_shutdown(
4635 const struct sctp_endpoint *ep,
4636 const struct sctp_association *asoc,
4637 const sctp_subtype_t type,
4638 void *arg,
4639 sctp_cmd_seq_t *commands)
4640{
4641 int disposition;
4642
4643 /* From 9.2 Shutdown of an Association
4644 * Upon receipt of the SHUTDOWN primitive from its upper
4645 * layer, the endpoint enters SHUTDOWN-PENDING state and
4646 * remains there until all outstanding data has been
4647 * acknowledged by its peer. The endpoint accepts no new data
4648 * from its upper layer, but retransmits data to the far end
4649 * if necessary to fill gaps.
4650 */
4651 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4652 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
4653
Linus Torvalds1da177e2005-04-16 15:20:36 -07004654 disposition = SCTP_DISPOSITION_CONSUME;
4655 if (sctp_outq_is_empty(&asoc->outqueue)) {
4656 disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type,
4657 arg, commands);
4658 }
4659 return disposition;
4660}
4661
4662/*
4663 * Process the ABORT primitive.
4664 *
4665 * Section: 10.1:
4666 * C) Abort
4667 *
4668 * Format: Abort(association id [, cause code])
4669 * -> result
4670 *
4671 * Ungracefully closes an association. Any locally queued user data
4672 * will be discarded and an ABORT chunk is sent to the peer. A success code
4673 * will be returned on successful abortion of the association. If
4674 * attempting to abort the association results in a failure, an error
4675 * code shall be returned.
4676 *
4677 * Mandatory attributes:
4678 *
4679 * o association id - local handle to the SCTP association
4680 *
4681 * Optional attributes:
4682 *
4683 * o cause code - reason of the abort to be passed to the peer
4684 *
4685 * None.
4686 *
4687 * The return value is the disposition.
4688 */
4689sctp_disposition_t sctp_sf_do_9_1_prm_abort(
4690 const struct sctp_endpoint *ep,
4691 const struct sctp_association *asoc,
4692 const sctp_subtype_t type,
4693 void *arg,
4694 sctp_cmd_seq_t *commands)
4695{
4696 /* From 9.1 Abort of an Association
4697 * Upon receipt of the ABORT primitive from its upper
4698 * layer, the endpoint enters CLOSED state and
4699 * discard all outstanding data has been
4700 * acknowledged by its peer. The endpoint accepts no new data
4701 * from its upper layer, but retransmits data to the far end
4702 * if necessary to fill gaps.
4703 */
Sridhar Samudralac164a9b2006-08-22 11:50:39 -07004704 struct sctp_chunk *abort = arg;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004705 sctp_disposition_t retval;
4706
4707 retval = SCTP_DISPOSITION_CONSUME;
4708
Sridhar Samudralac164a9b2006-08-22 11:50:39 -07004709 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004710
4711 /* Even if we can't send the ABORT due to low memory delete the
4712 * TCB. This is a departure from our typical NOMEM handling.
4713 */
4714
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004715 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4716 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004717 /* Delete the established association. */
4718 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08004719 SCTP_PERR(SCTP_ERROR_USER_ABORT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004720
4721 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4722 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
4723
4724 return retval;
4725}
4726
4727/* We tried an illegal operation on an association which is closed. */
4728sctp_disposition_t sctp_sf_error_closed(const struct sctp_endpoint *ep,
4729 const struct sctp_association *asoc,
4730 const sctp_subtype_t type,
4731 void *arg,
4732 sctp_cmd_seq_t *commands)
4733{
4734 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, SCTP_ERROR(-EINVAL));
4735 return SCTP_DISPOSITION_CONSUME;
4736}
4737
4738/* We tried an illegal operation on an association which is shutting
4739 * down.
4740 */
4741sctp_disposition_t sctp_sf_error_shutdown(const struct sctp_endpoint *ep,
4742 const struct sctp_association *asoc,
4743 const sctp_subtype_t type,
4744 void *arg,
4745 sctp_cmd_seq_t *commands)
4746{
4747 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR,
4748 SCTP_ERROR(-ESHUTDOWN));
4749 return SCTP_DISPOSITION_CONSUME;
4750}
4751
4752/*
4753 * sctp_cookie_wait_prm_shutdown
4754 *
4755 * Section: 4 Note: 2
4756 * Verification Tag:
4757 * Inputs
4758 * (endpoint, asoc)
4759 *
4760 * The RFC does not explicitly address this issue, but is the route through the
4761 * state table when someone issues a shutdown while in COOKIE_WAIT state.
4762 *
4763 * Outputs
4764 * (timers)
4765 */
4766sctp_disposition_t sctp_sf_cookie_wait_prm_shutdown(
4767 const struct sctp_endpoint *ep,
4768 const struct sctp_association *asoc,
4769 const sctp_subtype_t type,
4770 void *arg,
4771 sctp_cmd_seq_t *commands)
4772{
4773 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4774 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4775
4776 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4777 SCTP_STATE(SCTP_STATE_CLOSED));
4778
4779 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
4780
4781 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
4782
4783 return SCTP_DISPOSITION_DELETE_TCB;
4784}
4785
4786/*
4787 * sctp_cookie_echoed_prm_shutdown
4788 *
4789 * Section: 4 Note: 2
4790 * Verification Tag:
4791 * Inputs
4792 * (endpoint, asoc)
4793 *
4794 * The RFC does not explcitly address this issue, but is the route through the
4795 * state table when someone issues a shutdown while in COOKIE_ECHOED state.
4796 *
4797 * Outputs
4798 * (timers)
4799 */
4800sctp_disposition_t sctp_sf_cookie_echoed_prm_shutdown(
4801 const struct sctp_endpoint *ep,
4802 const struct sctp_association *asoc,
4803 const sctp_subtype_t type,
4804 void *arg, sctp_cmd_seq_t *commands)
4805{
4806 /* There is a single T1 timer, so we should be able to use
4807 * common function with the COOKIE-WAIT state.
4808 */
4809 return sctp_sf_cookie_wait_prm_shutdown(ep, asoc, type, arg, commands);
4810}
4811
4812/*
4813 * sctp_sf_cookie_wait_prm_abort
4814 *
4815 * Section: 4 Note: 2
4816 * Verification Tag:
4817 * Inputs
4818 * (endpoint, asoc)
4819 *
4820 * The RFC does not explicitly address this issue, but is the route through the
4821 * state table when someone issues an abort while in COOKIE_WAIT state.
4822 *
4823 * Outputs
4824 * (timers)
4825 */
4826sctp_disposition_t sctp_sf_cookie_wait_prm_abort(
4827 const struct sctp_endpoint *ep,
4828 const struct sctp_association *asoc,
4829 const sctp_subtype_t type,
4830 void *arg,
4831 sctp_cmd_seq_t *commands)
4832{
Sridhar Samudralac164a9b2006-08-22 11:50:39 -07004833 struct sctp_chunk *abort = arg;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004834 sctp_disposition_t retval;
4835
4836 /* Stop T1-init timer */
4837 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4838 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4839 retval = SCTP_DISPOSITION_CONSUME;
4840
Sridhar Samudralac164a9b2006-08-22 11:50:39 -07004841 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004842
4843 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4844 SCTP_STATE(SCTP_STATE_CLOSED));
4845
4846 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4847
4848 /* Even if we can't send the ABORT due to low memory delete the
4849 * TCB. This is a departure from our typical NOMEM handling.
4850 */
4851
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004852 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4853 SCTP_ERROR(ECONNREFUSED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004854 /* Delete the established association. */
4855 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08004856 SCTP_PERR(SCTP_ERROR_USER_ABORT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004857
4858 return retval;
4859}
4860
4861/*
4862 * sctp_sf_cookie_echoed_prm_abort
4863 *
4864 * Section: 4 Note: 3
4865 * Verification Tag:
4866 * Inputs
4867 * (endpoint, asoc)
4868 *
4869 * The RFC does not explcitly address this issue, but is the route through the
4870 * state table when someone issues an abort while in COOKIE_ECHOED state.
4871 *
4872 * Outputs
4873 * (timers)
4874 */
4875sctp_disposition_t sctp_sf_cookie_echoed_prm_abort(
4876 const struct sctp_endpoint *ep,
4877 const struct sctp_association *asoc,
4878 const sctp_subtype_t type,
4879 void *arg,
4880 sctp_cmd_seq_t *commands)
4881{
4882 /* There is a single T1 timer, so we should be able to use
4883 * common function with the COOKIE-WAIT state.
4884 */
4885 return sctp_sf_cookie_wait_prm_abort(ep, asoc, type, arg, commands);
4886}
4887
4888/*
4889 * sctp_sf_shutdown_pending_prm_abort
4890 *
4891 * Inputs
4892 * (endpoint, asoc)
4893 *
4894 * The RFC does not explicitly address this issue, but is the route through the
4895 * state table when someone issues an abort while in SHUTDOWN-PENDING state.
4896 *
4897 * Outputs
4898 * (timers)
4899 */
4900sctp_disposition_t sctp_sf_shutdown_pending_prm_abort(
4901 const struct sctp_endpoint *ep,
4902 const struct sctp_association *asoc,
4903 const sctp_subtype_t type,
4904 void *arg,
4905 sctp_cmd_seq_t *commands)
4906{
4907 /* Stop the T5-shutdown guard timer. */
4908 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4909 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4910
4911 return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands);
4912}
4913
4914/*
4915 * sctp_sf_shutdown_sent_prm_abort
4916 *
4917 * Inputs
4918 * (endpoint, asoc)
4919 *
4920 * The RFC does not explicitly address this issue, but is the route through the
4921 * state table when someone issues an abort while in SHUTDOWN-SENT state.
4922 *
4923 * Outputs
4924 * (timers)
4925 */
4926sctp_disposition_t sctp_sf_shutdown_sent_prm_abort(
4927 const struct sctp_endpoint *ep,
4928 const struct sctp_association *asoc,
4929 const sctp_subtype_t type,
4930 void *arg,
4931 sctp_cmd_seq_t *commands)
4932{
4933 /* Stop the T2-shutdown timer. */
4934 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4935 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4936
4937 /* Stop the T5-shutdown guard timer. */
4938 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4939 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4940
4941 return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands);
4942}
4943
4944/*
4945 * sctp_sf_cookie_echoed_prm_abort
4946 *
4947 * Inputs
4948 * (endpoint, asoc)
4949 *
4950 * The RFC does not explcitly address this issue, but is the route through the
4951 * state table when someone issues an abort while in COOKIE_ECHOED state.
4952 *
4953 * Outputs
4954 * (timers)
4955 */
4956sctp_disposition_t sctp_sf_shutdown_ack_sent_prm_abort(
4957 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{
4963 /* The same T2 timer, so we should be able to use
4964 * common function with the SHUTDOWN-SENT state.
4965 */
4966 return sctp_sf_shutdown_sent_prm_abort(ep, asoc, type, arg, commands);
4967}
4968
4969/*
4970 * Process the REQUESTHEARTBEAT primitive
4971 *
4972 * 10.1 ULP-to-SCTP
4973 * J) Request Heartbeat
4974 *
4975 * Format: REQUESTHEARTBEAT(association id, destination transport address)
4976 *
4977 * -> result
4978 *
4979 * Instructs the local endpoint to perform a HeartBeat on the specified
4980 * destination transport address of the given association. The returned
4981 * result should indicate whether the transmission of the HEARTBEAT
4982 * chunk to the destination address is successful.
4983 *
4984 * Mandatory attributes:
4985 *
4986 * o association id - local handle to the SCTP association
4987 *
4988 * o destination transport address - the transport address of the
4989 * association on which a heartbeat should be issued.
4990 */
4991sctp_disposition_t sctp_sf_do_prm_requestheartbeat(
4992 const struct sctp_endpoint *ep,
4993 const struct sctp_association *asoc,
4994 const sctp_subtype_t type,
4995 void *arg,
4996 sctp_cmd_seq_t *commands)
4997{
Vlad Yasevichfb785252007-03-19 17:02:03 -07004998 if (SCTP_DISPOSITION_NOMEM == sctp_sf_heartbeat(ep, asoc, type,
4999 (struct sctp_transport *)arg, commands))
5000 return SCTP_DISPOSITION_NOMEM;
5001
5002 /*
5003 * RFC 2960 (bis), section 8.3
5004 *
5005 * D) Request an on-demand HEARTBEAT on a specific destination
5006 * transport address of a given association.
5007 *
5008 * The endpoint should increment the respective error counter of
5009 * the destination transport address each time a HEARTBEAT is sent
5010 * to that address and not acknowledged within one RTO.
5011 *
5012 */
Vlad Yasevich7e990132009-03-02 09:46:14 +00005013 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_HB_SENT,
Vlad Yasevichfb785252007-03-19 17:02:03 -07005014 SCTP_TRANSPORT(arg));
5015 return SCTP_DISPOSITION_CONSUME;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005016}
5017
5018/*
5019 * ADDIP Section 4.1 ASCONF Chunk Procedures
5020 * When an endpoint has an ASCONF signaled change to be sent to the
5021 * remote endpoint it should do A1 to A9
5022 */
5023sctp_disposition_t sctp_sf_do_prm_asconf(const struct sctp_endpoint *ep,
5024 const struct sctp_association *asoc,
5025 const sctp_subtype_t type,
5026 void *arg,
5027 sctp_cmd_seq_t *commands)
5028{
5029 struct sctp_chunk *chunk = arg;
5030
5031 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
5032 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
5033 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
5034 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
5035 return SCTP_DISPOSITION_CONSUME;
5036}
5037
5038/*
5039 * Ignore the primitive event
5040 *
5041 * The return value is the disposition of the primitive.
5042 */
5043sctp_disposition_t sctp_sf_ignore_primitive(
5044 const struct sctp_endpoint *ep,
5045 const struct sctp_association *asoc,
5046 const sctp_subtype_t type,
5047 void *arg,
5048 sctp_cmd_seq_t *commands)
5049{
5050 SCTP_DEBUG_PRINTK("Primitive type %d is ignored.\n", type.primitive);
5051 return SCTP_DISPOSITION_DISCARD;
5052}
5053
5054/***************************************************************************
5055 * These are the state functions for the OTHER events.
5056 ***************************************************************************/
5057
5058/*
5059 * Start the shutdown negotiation.
5060 *
5061 * From Section 9.2:
5062 * Once all its outstanding data has been acknowledged, the endpoint
5063 * shall send a SHUTDOWN chunk to its peer including in the Cumulative
5064 * TSN Ack field the last sequential TSN it has received from the peer.
5065 * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT
5066 * state. If the timer expires, the endpoint must re-send the SHUTDOWN
5067 * with the updated last sequential TSN received from its peer.
5068 *
5069 * The return value is the disposition.
5070 */
5071sctp_disposition_t sctp_sf_do_9_2_start_shutdown(
5072 const struct sctp_endpoint *ep,
5073 const struct sctp_association *asoc,
5074 const sctp_subtype_t type,
5075 void *arg,
5076 sctp_cmd_seq_t *commands)
5077{
5078 struct sctp_chunk *reply;
5079
5080 /* Once all its outstanding data has been acknowledged, the
5081 * endpoint shall send a SHUTDOWN chunk to its peer including
5082 * in the Cumulative TSN Ack field the last sequential TSN it
5083 * has received from the peer.
5084 */
5085 reply = sctp_make_shutdown(asoc, NULL);
5086 if (!reply)
5087 goto nomem;
5088
5089 /* Set the transport for the SHUTDOWN chunk and the timeout for the
5090 * T2-shutdown timer.
5091 */
5092 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5093
5094 /* It shall then start the T2-shutdown timer */
5095 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
5096 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5097
Wei Yongjun536428a2008-09-05 08:55:26 +08005098 /* RFC 4960 Section 9.2
5099 * The sender of the SHUTDOWN MAY also start an overall guard timer
5100 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5101 */
5102 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
5103 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5104
Linus Torvalds1da177e2005-04-16 15:20:36 -07005105 if (asoc->autoclose)
5106 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5107 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
5108
5109 /* and enter the SHUTDOWN-SENT state. */
5110 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5111 SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT));
5112
5113 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5114 *
5115 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09005116 * or SHUTDOWN-ACK.
Linus Torvalds1da177e2005-04-16 15:20:36 -07005117 */
5118 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
5119
5120 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5121
5122 return SCTP_DISPOSITION_CONSUME;
5123
5124nomem:
5125 return SCTP_DISPOSITION_NOMEM;
5126}
5127
5128/*
5129 * Generate a SHUTDOWN ACK now that everything is SACK'd.
5130 *
5131 * From Section 9.2:
5132 *
5133 * If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5134 * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own,
5135 * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the
5136 * endpoint must re-send the SHUTDOWN ACK.
5137 *
5138 * The return value is the disposition.
5139 */
5140sctp_disposition_t sctp_sf_do_9_2_shutdown_ack(
5141 const struct sctp_endpoint *ep,
5142 const struct sctp_association *asoc,
5143 const sctp_subtype_t type,
5144 void *arg,
5145 sctp_cmd_seq_t *commands)
5146{
5147 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
5148 struct sctp_chunk *reply;
5149
5150 /* There are 2 ways of getting here:
5151 * 1) called in response to a SHUTDOWN chunk
5152 * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued.
5153 *
5154 * For the case (2), the arg parameter is set to NULL. We need
5155 * to check that we have a chunk before accessing it's fields.
5156 */
5157 if (chunk) {
5158 if (!sctp_vtag_verify(chunk, asoc))
5159 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
5160
5161 /* Make sure that the SHUTDOWN chunk has a valid length. */
5162 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_shutdown_chunk_t)))
5163 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
5164 commands);
5165 }
5166
5167 /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5168 * shall send a SHUTDOWN ACK ...
5169 */
5170 reply = sctp_make_shutdown_ack(asoc, chunk);
5171 if (!reply)
5172 goto nomem;
5173
5174 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
5175 * the T2-shutdown timer.
5176 */
5177 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5178
5179 /* and start/restart a T2-shutdown timer of its own, */
5180 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5181 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5182
5183 if (asoc->autoclose)
5184 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5185 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
5186
5187 /* Enter the SHUTDOWN-ACK-SENT state. */
5188 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5189 SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT));
5190
5191 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5192 *
5193 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09005194 * or SHUTDOWN-ACK.
Linus Torvalds1da177e2005-04-16 15:20:36 -07005195 */
5196 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
5197
5198 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5199
5200 return SCTP_DISPOSITION_CONSUME;
5201
5202nomem:
5203 return SCTP_DISPOSITION_NOMEM;
5204}
5205
5206/*
5207 * Ignore the event defined as other
5208 *
5209 * The return value is the disposition of the event.
5210 */
5211sctp_disposition_t sctp_sf_ignore_other(const struct sctp_endpoint *ep,
5212 const struct sctp_association *asoc,
5213 const sctp_subtype_t type,
5214 void *arg,
5215 sctp_cmd_seq_t *commands)
5216{
5217 SCTP_DEBUG_PRINTK("The event other type %d is ignored\n", type.other);
5218 return SCTP_DISPOSITION_DISCARD;
5219}
5220
5221/************************************************************
5222 * These are the state functions for handling timeout events.
5223 ************************************************************/
5224
5225/*
5226 * RTX Timeout
5227 *
5228 * Section: 6.3.3 Handle T3-rtx Expiration
5229 *
5230 * Whenever the retransmission timer T3-rtx expires for a destination
5231 * address, do the following:
5232 * [See below]
5233 *
5234 * The return value is the disposition of the chunk.
5235 */
5236sctp_disposition_t sctp_sf_do_6_3_3_rtx(const struct sctp_endpoint *ep,
5237 const struct sctp_association *asoc,
5238 const sctp_subtype_t type,
5239 void *arg,
5240 sctp_cmd_seq_t *commands)
5241{
5242 struct sctp_transport *transport = arg;
5243
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07005244 SCTP_INC_STATS(SCTP_MIB_T3_RTX_EXPIREDS);
5245
Linus Torvalds1da177e2005-04-16 15:20:36 -07005246 if (asoc->overall_error_count >= asoc->max_retrans) {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07005247 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5248 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005249 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5250 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08005251 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005252 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
5253 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
5254 return SCTP_DISPOSITION_DELETE_TCB;
5255 }
5256
5257 /* E1) For the destination address for which the timer
5258 * expires, adjust its ssthresh with rules defined in Section
5259 * 7.2.3 and set the cwnd <- MTU.
5260 */
5261
5262 /* E2) For the destination address for which the timer
5263 * expires, set RTO <- RTO * 2 ("back off the timer"). The
5264 * maximum value discussed in rule C7 above (RTO.max) may be
5265 * used to provide an upper bound to this doubling operation.
5266 */
5267
5268 /* E3) Determine how many of the earliest (i.e., lowest TSN)
5269 * outstanding DATA chunks for the address for which the
5270 * T3-rtx has expired will fit into a single packet, subject
5271 * to the MTU constraint for the path corresponding to the
5272 * destination transport address to which the retransmission
5273 * is being sent (this may be different from the address for
5274 * which the timer expires [see Section 6.4]). Call this
5275 * value K. Bundle and retransmit those K DATA chunks in a
5276 * single packet to the destination endpoint.
5277 *
5278 * Note: Any DATA chunks that were sent to the address for
5279 * which the T3-rtx timer expired but did not fit in one MTU
5280 * (rule E3 above), should be marked for retransmission and
5281 * sent as soon as cwnd allows (normally when a SACK arrives).
5282 */
5283
Linus Torvalds1da177e2005-04-16 15:20:36 -07005284 /* Do some failure management (Section 8.2). */
5285 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
5286
Vlad Yasevich1845a572007-02-21 02:06:19 -08005287 /* NB: Rules E4 and F1 are implicit in R1. */
5288 sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN, SCTP_TRANSPORT(transport));
5289
Linus Torvalds1da177e2005-04-16 15:20:36 -07005290 return SCTP_DISPOSITION_CONSUME;
5291}
5292
5293/*
5294 * Generate delayed SACK on timeout
5295 *
5296 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
5297 *
5298 * The guidelines on delayed acknowledgement algorithm specified in
5299 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
5300 * acknowledgement SHOULD be generated for at least every second packet
5301 * (not every second DATA chunk) received, and SHOULD be generated
5302 * within 200 ms of the arrival of any unacknowledged DATA chunk. In
5303 * some situations it may be beneficial for an SCTP transmitter to be
5304 * more conservative than the algorithms detailed in this document
5305 * allow. However, an SCTP transmitter MUST NOT be more aggressive than
5306 * the following algorithms allow.
5307 */
5308sctp_disposition_t sctp_sf_do_6_2_sack(const struct sctp_endpoint *ep,
5309 const struct sctp_association *asoc,
5310 const sctp_subtype_t type,
5311 void *arg,
5312 sctp_cmd_seq_t *commands)
5313{
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07005314 SCTP_INC_STATS(SCTP_MIB_DELAY_SACK_EXPIREDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005315 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
5316 return SCTP_DISPOSITION_CONSUME;
5317}
5318
5319/*
Frank Filz3f7a87d2005-06-20 13:14:57 -07005320 * sctp_sf_t1_init_timer_expire
Linus Torvalds1da177e2005-04-16 15:20:36 -07005321 *
5322 * Section: 4 Note: 2
5323 * Verification Tag:
5324 * Inputs
5325 * (endpoint, asoc)
5326 *
5327 * RFC 2960 Section 4 Notes
5328 * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT
5329 * and re-start the T1-init timer without changing state. This MUST
5330 * be repeated up to 'Max.Init.Retransmits' times. After that, the
5331 * endpoint MUST abort the initialization process and report the
5332 * error to SCTP user.
5333 *
Frank Filz3f7a87d2005-06-20 13:14:57 -07005334 * Outputs
5335 * (timers, events)
5336 *
5337 */
5338sctp_disposition_t sctp_sf_t1_init_timer_expire(const struct sctp_endpoint *ep,
5339 const struct sctp_association *asoc,
5340 const sctp_subtype_t type,
5341 void *arg,
5342 sctp_cmd_seq_t *commands)
5343{
5344 struct sctp_chunk *repl = NULL;
5345 struct sctp_bind_addr *bp;
5346 int attempts = asoc->init_err_counter + 1;
5347
5348 SCTP_DEBUG_PRINTK("Timer T1 expired (INIT).\n");
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07005349 SCTP_INC_STATS(SCTP_MIB_T1_INIT_EXPIREDS);
Frank Filz3f7a87d2005-06-20 13:14:57 -07005350
Vlad Yasevich81845c22006-01-30 15:59:54 -08005351 if (attempts <= asoc->max_init_attempts) {
Frank Filz3f7a87d2005-06-20 13:14:57 -07005352 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
5353 repl = sctp_make_init(asoc, bp, GFP_ATOMIC, 0);
5354 if (!repl)
5355 return SCTP_DISPOSITION_NOMEM;
5356
5357 /* Choose transport for INIT. */
5358 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
5359 SCTP_CHUNK(repl));
5360
5361 /* Issue a sideeffect to do the needed accounting. */
5362 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_RESTART,
5363 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
5364
5365 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
5366 } else {
5367 SCTP_DEBUG_PRINTK("Giving up on INIT, attempts: %d"
5368 " max_init_attempts: %d\n",
5369 attempts, asoc->max_init_attempts);
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07005370 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5371 SCTP_ERROR(ETIMEDOUT));
Frank Filz3f7a87d2005-06-20 13:14:57 -07005372 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08005373 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Frank Filz3f7a87d2005-06-20 13:14:57 -07005374 return SCTP_DISPOSITION_DELETE_TCB;
5375 }
5376
5377 return SCTP_DISPOSITION_CONSUME;
5378}
5379
5380/*
5381 * sctp_sf_t1_cookie_timer_expire
5382 *
5383 * Section: 4 Note: 2
5384 * Verification Tag:
5385 * Inputs
5386 * (endpoint, asoc)
5387 *
5388 * RFC 2960 Section 4 Notes
5389 * 3) If the T1-cookie timer expires, the endpoint MUST retransmit
Linus Torvalds1da177e2005-04-16 15:20:36 -07005390 * COOKIE ECHO and re-start the T1-cookie timer without changing
5391 * state. This MUST be repeated up to 'Max.Init.Retransmits' times.
5392 * After that, the endpoint MUST abort the initialization process and
5393 * report the error to SCTP user.
5394 *
5395 * Outputs
5396 * (timers, events)
5397 *
5398 */
Frank Filz3f7a87d2005-06-20 13:14:57 -07005399sctp_disposition_t sctp_sf_t1_cookie_timer_expire(const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005400 const struct sctp_association *asoc,
5401 const sctp_subtype_t type,
5402 void *arg,
5403 sctp_cmd_seq_t *commands)
5404{
Frank Filz3f7a87d2005-06-20 13:14:57 -07005405 struct sctp_chunk *repl = NULL;
5406 int attempts = asoc->init_err_counter + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005407
Frank Filz3f7a87d2005-06-20 13:14:57 -07005408 SCTP_DEBUG_PRINTK("Timer T1 expired (COOKIE-ECHO).\n");
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07005409 SCTP_INC_STATS(SCTP_MIB_T1_COOKIE_EXPIREDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005410
Vlad Yasevich81845c22006-01-30 15:59:54 -08005411 if (attempts <= asoc->max_init_attempts) {
Frank Filz3f7a87d2005-06-20 13:14:57 -07005412 repl = sctp_make_cookie_echo(asoc, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005413 if (!repl)
Frank Filz3f7a87d2005-06-20 13:14:57 -07005414 return SCTP_DISPOSITION_NOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005415
Vlad Yasevich96cd0d32008-09-08 14:00:26 -04005416 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
5417 SCTP_CHUNK(repl));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005418 /* Issue a sideeffect to do the needed accounting. */
Frank Filz3f7a87d2005-06-20 13:14:57 -07005419 sctp_add_cmd_sf(commands, SCTP_CMD_COOKIEECHO_RESTART,
5420 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
5421
Linus Torvalds1da177e2005-04-16 15:20:36 -07005422 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
5423 } else {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07005424 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5425 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005426 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08005427 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005428 return SCTP_DISPOSITION_DELETE_TCB;
5429 }
5430
5431 return SCTP_DISPOSITION_CONSUME;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005432}
5433
5434/* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN
5435 * with the updated last sequential TSN received from its peer.
5436 *
5437 * An endpoint should limit the number of retransmissions of the
5438 * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'.
5439 * If this threshold is exceeded the endpoint should destroy the TCB and
5440 * MUST report the peer endpoint unreachable to the upper layer (and
5441 * thus the association enters the CLOSED state). The reception of any
5442 * packet from its peer (i.e. as the peer sends all of its queued DATA
5443 * chunks) should clear the endpoint's retransmission count and restart
5444 * the T2-Shutdown timer, giving its peer ample opportunity to transmit
5445 * all of its queued DATA chunks that have not yet been sent.
5446 */
5447sctp_disposition_t sctp_sf_t2_timer_expire(const struct sctp_endpoint *ep,
5448 const struct sctp_association *asoc,
5449 const sctp_subtype_t type,
5450 void *arg,
5451 sctp_cmd_seq_t *commands)
5452{
5453 struct sctp_chunk *reply = NULL;
5454
5455 SCTP_DEBUG_PRINTK("Timer T2 expired.\n");
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07005456 SCTP_INC_STATS(SCTP_MIB_T2_SHUTDOWN_EXPIREDS);
5457
Neil Horman58fbbed2008-02-29 11:40:56 -08005458 ((struct sctp_association *)asoc)->shutdown_retries++;
5459
Linus Torvalds1da177e2005-04-16 15:20:36 -07005460 if (asoc->overall_error_count >= asoc->max_retrans) {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07005461 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5462 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005463 /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5464 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08005465 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005466 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
5467 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
5468 return SCTP_DISPOSITION_DELETE_TCB;
5469 }
5470
5471 switch (asoc->state) {
5472 case SCTP_STATE_SHUTDOWN_SENT:
5473 reply = sctp_make_shutdown(asoc, NULL);
5474 break;
5475
5476 case SCTP_STATE_SHUTDOWN_ACK_SENT:
5477 reply = sctp_make_shutdown_ack(asoc, NULL);
5478 break;
5479
5480 default:
5481 BUG();
5482 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07005483 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07005484
5485 if (!reply)
5486 goto nomem;
5487
Wei Yongjun6345b192009-04-26 23:13:35 +08005488 /* Do some failure management (Section 8.2).
5489 * If we remove the transport an SHUTDOWN was last sent to, don't
5490 * do failure management.
5491 */
5492 if (asoc->shutdown_last_sent_to)
5493 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
5494 SCTP_TRANSPORT(asoc->shutdown_last_sent_to));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005495
5496 /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for
5497 * the T2-shutdown timer.
5498 */
5499 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5500
5501 /* Restart the T2-shutdown timer. */
5502 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5503 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5504 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5505 return SCTP_DISPOSITION_CONSUME;
5506
5507nomem:
5508 return SCTP_DISPOSITION_NOMEM;
5509}
5510
5511/*
5512 * ADDIP Section 4.1 ASCONF CHunk Procedures
5513 * If the T4 RTO timer expires the endpoint should do B1 to B5
5514 */
5515sctp_disposition_t sctp_sf_t4_timer_expire(
5516 const struct sctp_endpoint *ep,
5517 const struct sctp_association *asoc,
5518 const sctp_subtype_t type,
5519 void *arg,
5520 sctp_cmd_seq_t *commands)
5521{
5522 struct sctp_chunk *chunk = asoc->addip_last_asconf;
5523 struct sctp_transport *transport = chunk->transport;
5524
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07005525 SCTP_INC_STATS(SCTP_MIB_T4_RTO_EXPIREDS);
5526
Linus Torvalds1da177e2005-04-16 15:20:36 -07005527 /* ADDIP 4.1 B1) Increment the error counters and perform path failure
5528 * detection on the appropriate destination address as defined in
5529 * RFC2960 [5] section 8.1 and 8.2.
5530 */
Wei Yongjun10a43ce2009-04-26 23:14:42 +08005531 if (transport)
5532 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
5533 SCTP_TRANSPORT(transport));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005534
5535 /* Reconfig T4 timer and transport. */
5536 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
5537
5538 /* ADDIP 4.1 B2) Increment the association error counters and perform
5539 * endpoint failure detection on the association as defined in
5540 * RFC2960 [5] section 8.1 and 8.2.
5541 * association error counter is incremented in SCTP_CMD_STRIKE.
5542 */
5543 if (asoc->overall_error_count >= asoc->max_retrans) {
5544 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5545 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07005546 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5547 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005548 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08005549 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005550 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
Wei Yongjun3d5a0192008-10-09 14:32:24 -07005551 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005552 return SCTP_DISPOSITION_ABORT;
5553 }
5554
5555 /* ADDIP 4.1 B3) Back-off the destination address RTO value to which
5556 * the ASCONF chunk was sent by doubling the RTO timer value.
5557 * This is done in SCTP_CMD_STRIKE.
5558 */
5559
5560 /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible
5561 * choose an alternate destination address (please refer to RFC2960
5562 * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09005563 * chunk, it MUST be the same (including its serial number) as the last
Linus Torvalds1da177e2005-04-16 15:20:36 -07005564 * ASCONF sent.
5565 */
5566 sctp_chunk_hold(asoc->addip_last_asconf);
5567 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
5568 SCTP_CHUNK(asoc->addip_last_asconf));
5569
5570 /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different
5571 * destination is selected, then the RTO used will be that of the new
5572 * destination address.
5573 */
5574 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5575 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
5576
5577 return SCTP_DISPOSITION_CONSUME;
5578}
5579
5580/* sctpimpguide-05 Section 2.12.2
5581 * The sender of the SHUTDOWN MAY also start an overall guard timer
5582 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5583 * At the expiration of this timer the sender SHOULD abort the association
5584 * by sending an ABORT chunk.
5585 */
5586sctp_disposition_t sctp_sf_t5_timer_expire(const struct sctp_endpoint *ep,
5587 const struct sctp_association *asoc,
5588 const sctp_subtype_t type,
5589 void *arg,
5590 sctp_cmd_seq_t *commands)
5591{
5592 struct sctp_chunk *reply = NULL;
5593
5594 SCTP_DEBUG_PRINTK("Timer T5 expired.\n");
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07005595 SCTP_INC_STATS(SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005596
5597 reply = sctp_make_abort(asoc, NULL, 0);
5598 if (!reply)
5599 goto nomem;
5600
5601 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07005602 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5603 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005604 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08005605 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005606
Vlad Yasevicha1080a82008-10-09 14:33:26 -07005607 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
5608 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
5609
Linus Torvalds1da177e2005-04-16 15:20:36 -07005610 return SCTP_DISPOSITION_DELETE_TCB;
5611nomem:
5612 return SCTP_DISPOSITION_NOMEM;
5613}
5614
5615/* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires,
5616 * the association is automatically closed by starting the shutdown process.
5617 * The work that needs to be done is same as when SHUTDOWN is initiated by
5618 * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown().
5619 */
5620sctp_disposition_t sctp_sf_autoclose_timer_expire(
5621 const struct sctp_endpoint *ep,
5622 const struct sctp_association *asoc,
5623 const sctp_subtype_t type,
5624 void *arg,
5625 sctp_cmd_seq_t *commands)
5626{
5627 int disposition;
5628
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07005629 SCTP_INC_STATS(SCTP_MIB_AUTOCLOSE_EXPIREDS);
5630
Linus Torvalds1da177e2005-04-16 15:20:36 -07005631 /* From 9.2 Shutdown of an Association
5632 * Upon receipt of the SHUTDOWN primitive from its upper
5633 * layer, the endpoint enters SHUTDOWN-PENDING state and
5634 * remains there until all outstanding data has been
5635 * acknowledged by its peer. The endpoint accepts no new data
5636 * from its upper layer, but retransmits data to the far end
5637 * if necessary to fill gaps.
5638 */
5639 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5640 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
5641
Linus Torvalds1da177e2005-04-16 15:20:36 -07005642 disposition = SCTP_DISPOSITION_CONSUME;
5643 if (sctp_outq_is_empty(&asoc->outqueue)) {
5644 disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type,
5645 arg, commands);
5646 }
5647 return disposition;
5648}
5649
5650/*****************************************************************************
5651 * These are sa state functions which could apply to all types of events.
5652 ****************************************************************************/
5653
5654/*
5655 * This table entry is not implemented.
5656 *
5657 * Inputs
5658 * (endpoint, asoc, chunk)
5659 *
5660 * The return value is the disposition of the chunk.
5661 */
5662sctp_disposition_t sctp_sf_not_impl(const struct sctp_endpoint *ep,
5663 const struct sctp_association *asoc,
5664 const sctp_subtype_t type,
5665 void *arg,
5666 sctp_cmd_seq_t *commands)
5667{
5668 return SCTP_DISPOSITION_NOT_IMPL;
5669}
5670
5671/*
5672 * This table entry represents a bug.
5673 *
5674 * Inputs
5675 * (endpoint, asoc, chunk)
5676 *
5677 * The return value is the disposition of the chunk.
5678 */
5679sctp_disposition_t sctp_sf_bug(const struct sctp_endpoint *ep,
5680 const struct sctp_association *asoc,
5681 const sctp_subtype_t type,
5682 void *arg,
5683 sctp_cmd_seq_t *commands)
5684{
5685 return SCTP_DISPOSITION_BUG;
5686}
5687
5688/*
5689 * This table entry represents the firing of a timer in the wrong state.
5690 * Since timer deletion cannot be guaranteed a timer 'may' end up firing
5691 * when the association is in the wrong state. This event should
5692 * be ignored, so as to prevent any rearming of the timer.
5693 *
5694 * Inputs
5695 * (endpoint, asoc, chunk)
5696 *
5697 * The return value is the disposition of the chunk.
5698 */
5699sctp_disposition_t sctp_sf_timer_ignore(const struct sctp_endpoint *ep,
5700 const struct sctp_association *asoc,
5701 const sctp_subtype_t type,
5702 void *arg,
5703 sctp_cmd_seq_t *commands)
5704{
5705 SCTP_DEBUG_PRINTK("Timer %d ignored.\n", type.chunk);
5706 return SCTP_DISPOSITION_CONSUME;
5707}
5708
5709/********************************************************************
5710 * 2nd Level Abstractions
5711 ********************************************************************/
5712
5713/* Pull the SACK chunk based on the SACK header. */
5714static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk)
5715{
5716 struct sctp_sackhdr *sack;
5717 unsigned int len;
5718 __u16 num_blocks;
5719 __u16 num_dup_tsns;
5720
5721 /* Protect ourselves from reading too far into
5722 * the skb from a bogus sender.
5723 */
5724 sack = (struct sctp_sackhdr *) chunk->skb->data;
5725
5726 num_blocks = ntohs(sack->num_gap_ack_blocks);
5727 num_dup_tsns = ntohs(sack->num_dup_tsns);
5728 len = sizeof(struct sctp_sackhdr);
5729 len += (num_blocks + num_dup_tsns) * sizeof(__u32);
5730 if (len > chunk->skb->len)
5731 return NULL;
5732
5733 skb_pull(chunk->skb, len);
5734
5735 return sack;
5736}
5737
5738/* Create an ABORT packet to be sent as a response, with the specified
5739 * error causes.
5740 */
5741static struct sctp_packet *sctp_abort_pkt_new(const struct sctp_endpoint *ep,
5742 const struct sctp_association *asoc,
5743 struct sctp_chunk *chunk,
5744 const void *payload,
5745 size_t paylen)
5746{
5747 struct sctp_packet *packet;
5748 struct sctp_chunk *abort;
5749
5750 packet = sctp_ootb_pkt_new(asoc, chunk);
5751
5752 if (packet) {
5753 /* Make an ABORT.
5754 * The T bit will be set if the asoc is NULL.
5755 */
5756 abort = sctp_make_abort(asoc, chunk, paylen);
5757 if (!abort) {
5758 sctp_ootb_pkt_free(packet);
5759 return NULL;
5760 }
Jerome Forissier047a2422005-04-28 11:58:43 -07005761
5762 /* Reflect vtag if T-Bit is set */
5763 if (sctp_test_T_bit(abort))
5764 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
5765
Linus Torvalds1da177e2005-04-16 15:20:36 -07005766 /* Add specified error causes, i.e., payload, to the
5767 * end of the chunk.
5768 */
5769 sctp_addto_chunk(abort, paylen, payload);
5770
5771 /* Set the skb to the belonging sock for accounting. */
5772 abort->skb->sk = ep->base.sk;
5773
5774 sctp_packet_append_chunk(packet, abort);
5775
5776 }
5777
5778 return packet;
5779}
5780
5781/* Allocate a packet for responding in the OOTB conditions. */
5782static struct sctp_packet *sctp_ootb_pkt_new(const struct sctp_association *asoc,
5783 const struct sctp_chunk *chunk)
5784{
5785 struct sctp_packet *packet;
5786 struct sctp_transport *transport;
5787 __u16 sport;
5788 __u16 dport;
5789 __u32 vtag;
5790
5791 /* Get the source and destination port from the inbound packet. */
5792 sport = ntohs(chunk->sctp_hdr->dest);
5793 dport = ntohs(chunk->sctp_hdr->source);
5794
5795 /* The V-tag is going to be the same as the inbound packet if no
5796 * association exists, otherwise, use the peer's vtag.
5797 */
5798 if (asoc) {
Wei Yongjun02c4e122007-08-31 10:03:58 +08005799 /* Special case the INIT-ACK as there is no peer's vtag
5800 * yet.
5801 */
5802 switch(chunk->chunk_hdr->type) {
5803 case SCTP_CID_INIT_ACK:
5804 {
5805 sctp_initack_chunk_t *initack;
5806
5807 initack = (sctp_initack_chunk_t *)chunk->chunk_hdr;
5808 vtag = ntohl(initack->init_hdr.init_tag);
5809 break;
5810 }
5811 default:
5812 vtag = asoc->peer.i.init_tag;
5813 break;
5814 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07005815 } else {
5816 /* Special case the INIT and stale COOKIE_ECHO as there is no
5817 * vtag yet.
5818 */
5819 switch(chunk->chunk_hdr->type) {
5820 case SCTP_CID_INIT:
5821 {
5822 sctp_init_chunk_t *init;
5823
5824 init = (sctp_init_chunk_t *)chunk->chunk_hdr;
5825 vtag = ntohl(init->init_hdr.init_tag);
5826 break;
5827 }
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09005828 default:
Linus Torvalds1da177e2005-04-16 15:20:36 -07005829 vtag = ntohl(chunk->sctp_hdr->vtag);
5830 break;
5831 }
5832 }
5833
5834 /* Make a transport for the bucket, Eliza... */
Al Viro6a1e5f32006-11-20 17:12:25 -08005835 transport = sctp_transport_new(sctp_source(chunk), GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005836 if (!transport)
5837 goto nomem;
5838
5839 /* Cache a route for the transport with the chunk's destination as
5840 * the source address.
5841 */
Al Viro16b0a032006-11-20 17:13:38 -08005842 sctp_transport_route(transport, (union sctp_addr *)&chunk->dest,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005843 sctp_sk(sctp_get_ctl_sock()));
5844
5845 packet = sctp_packet_init(&transport->packet, transport, sport, dport);
5846 packet = sctp_packet_config(packet, vtag, 0);
5847
5848 return packet;
5849
5850nomem:
5851 return NULL;
5852}
5853
5854/* Free the packet allocated earlier for responding in the OOTB condition. */
5855void sctp_ootb_pkt_free(struct sctp_packet *packet)
5856{
5857 sctp_transport_free(packet->transport);
5858}
5859
5860/* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */
5861static void sctp_send_stale_cookie_err(const struct sctp_endpoint *ep,
5862 const struct sctp_association *asoc,
5863 const struct sctp_chunk *chunk,
5864 sctp_cmd_seq_t *commands,
5865 struct sctp_chunk *err_chunk)
5866{
5867 struct sctp_packet *packet;
5868
5869 if (err_chunk) {
5870 packet = sctp_ootb_pkt_new(asoc, chunk);
5871 if (packet) {
5872 struct sctp_signed_cookie *cookie;
5873
5874 /* Override the OOTB vtag from the cookie. */
5875 cookie = chunk->subh.cookie_hdr;
5876 packet->vtag = cookie->c.peer_vtag;
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09005877
Linus Torvalds1da177e2005-04-16 15:20:36 -07005878 /* Set the skb to the belonging sock for accounting. */
5879 err_chunk->skb->sk = ep->base.sk;
5880 sctp_packet_append_chunk(packet, err_chunk);
5881 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
5882 SCTP_PACKET(packet));
5883 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
5884 } else
5885 sctp_chunk_free (err_chunk);
5886 }
5887}
5888
5889
5890/* Process a data chunk */
5891static int sctp_eat_data(const struct sctp_association *asoc,
5892 struct sctp_chunk *chunk,
5893 sctp_cmd_seq_t *commands)
5894{
5895 sctp_datahdr_t *data_hdr;
5896 struct sctp_chunk *err;
5897 size_t datalen;
5898 sctp_verb_t deliver;
5899 int tmp;
5900 __u32 tsn;
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005901 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
Neil Horman049b3ff2005-11-11 16:08:24 -08005902 struct sock *sk = asoc->base.sk;
Vlad Yasevichf1751c52009-09-04 18:21:03 -04005903 u16 ssn;
5904 u16 sid;
5905 u8 ordered = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005906
5907 data_hdr = chunk->subh.data_hdr = (sctp_datahdr_t *)chunk->skb->data;
5908 skb_pull(chunk->skb, sizeof(sctp_datahdr_t));
5909
5910 tsn = ntohl(data_hdr->tsn);
5911 SCTP_DEBUG_PRINTK("eat_data: TSN 0x%x.\n", tsn);
5912
5913 /* ASSERT: Now skb->data is really the user data. */
5914
Linus Torvalds1da177e2005-04-16 15:20:36 -07005915 /* Process ECN based congestion.
5916 *
5917 * Since the chunk structure is reused for all chunks within
5918 * a packet, we use ecn_ce_done to track if we've already
5919 * done CE processing for this packet.
5920 *
5921 * We need to do ECN processing even if we plan to discard the
5922 * chunk later.
5923 */
5924
5925 if (!chunk->ecn_ce_done) {
5926 struct sctp_af *af;
5927 chunk->ecn_ce_done = 1;
5928
5929 af = sctp_get_af_specific(
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07005930 ipver2af(ip_hdr(chunk->skb)->version));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005931
5932 if (af && af->is_ce(chunk->skb) && asoc->peer.ecn_capable) {
5933 /* Do real work as sideffect. */
5934 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_CE,
5935 SCTP_U32(tsn));
5936 }
5937 }
5938
5939 tmp = sctp_tsnmap_check(&asoc->peer.tsn_map, tsn);
5940 if (tmp < 0) {
5941 /* The TSN is too high--silently discard the chunk and
5942 * count on it getting retransmitted later.
5943 */
5944 return SCTP_IERROR_HIGH_TSN;
5945 } else if (tmp > 0) {
5946 /* This is a duplicate. Record it. */
5947 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_DUP, SCTP_U32(tsn));
5948 return SCTP_IERROR_DUP_TSN;
5949 }
5950
5951 /* This is a new TSN. */
5952
5953 /* Discard if there is no room in the receive window.
5954 * Actually, allow a little bit of overflow (up to a MTU).
5955 */
5956 datalen = ntohs(chunk->chunk_hdr->length);
5957 datalen -= sizeof(sctp_data_chunk_t);
5958
5959 deliver = SCTP_CMD_CHUNK_ULP;
5960
5961 /* Think about partial delivery. */
5962 if ((datalen >= asoc->rwnd) && (!asoc->ulpq.pd_mode)) {
5963
5964 /* Even if we don't accept this chunk there is
5965 * memory pressure.
5966 */
5967 sctp_add_cmd_sf(commands, SCTP_CMD_PART_DELIVER, SCTP_NULL());
5968 }
5969
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09005970 /* Spill over rwnd a little bit. Note: While allowed, this spill over
Linus Torvalds1da177e2005-04-16 15:20:36 -07005971 * seems a bit troublesome in that frag_point varies based on
5972 * PMTU. In cases, such as loopback, this might be a rather
5973 * large spill over.
5974 */
Neil Horman4d93df02007-08-15 16:07:44 -07005975 if ((!chunk->data_accepted) && (!asoc->rwnd || asoc->rwnd_over ||
5976 (datalen > asoc->rwnd + asoc->frag_point))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07005977
5978 /* If this is the next TSN, consider reneging to make
5979 * room. Note: Playing nice with a confused sender. A
5980 * malicious sender can still eat up all our buffer
5981 * space and in the future we may want to detect and
5982 * do more drastic reneging.
5983 */
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005984 if (sctp_tsnmap_has_gap(map) &&
5985 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07005986 SCTP_DEBUG_PRINTK("Reneging for tsn:%u\n", tsn);
5987 deliver = SCTP_CMD_RENEGE;
5988 } else {
5989 SCTP_DEBUG_PRINTK("Discard tsn: %u len: %Zd, "
5990 "rwnd: %d\n", tsn, datalen,
5991 asoc->rwnd);
5992 return SCTP_IERROR_IGNORE_TSN;
5993 }
5994 }
5995
5996 /*
Neil Horman4d93df02007-08-15 16:07:44 -07005997 * Also try to renege to limit our memory usage in the event that
5998 * we are under memory pressure
Hideo Aoki3ab224b2007-12-31 00:11:19 -08005999 * If we can't renege, don't worry about it, the sk_rmem_schedule
Neil Horman4d93df02007-08-15 16:07:44 -07006000 * in sctp_ulpevent_make_rcvmsg will drop the frame if we grow our
6001 * memory usage too much
6002 */
6003 if (*sk->sk_prot_creator->memory_pressure) {
6004 if (sctp_tsnmap_has_gap(map) &&
6005 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
6006 SCTP_DEBUG_PRINTK("Under Pressure! Reneging for tsn:%u\n", tsn);
6007 deliver = SCTP_CMD_RENEGE;
6008 }
6009 }
6010
6011 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -07006012 * Section 3.3.10.9 No User Data (9)
6013 *
6014 * Cause of error
6015 * ---------------
6016 * No User Data: This error cause is returned to the originator of a
6017 * DATA chunk if a received DATA chunk has no user data.
6018 */
6019 if (unlikely(0 == datalen)) {
6020 err = sctp_make_abort_no_data(asoc, chunk, tsn);
6021 if (err) {
6022 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
6023 SCTP_CHUNK(err));
6024 }
6025 /* We are going to ABORT, so we might as well stop
6026 * processing the rest of the chunks in the packet.
6027 */
6028 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07006029 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
6030 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07006031 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08006032 SCTP_PERR(SCTP_ERROR_NO_DATA));
Linus Torvalds1da177e2005-04-16 15:20:36 -07006033 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
6034 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
6035 return SCTP_IERROR_NO_DATA;
6036 }
6037
Sridhar Samudrala9faa7302006-07-21 14:49:07 -07006038 chunk->data_accepted = 1;
6039
Linus Torvalds1da177e2005-04-16 15:20:36 -07006040 /* Note: Some chunks may get overcounted (if we drop) or overcounted
6041 * if we renege and the chunk arrives again.
6042 */
6043 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
6044 SCTP_INC_STATS(SCTP_MIB_INUNORDERCHUNKS);
Vlad Yasevichf1751c52009-09-04 18:21:03 -04006045 else {
Linus Torvalds1da177e2005-04-16 15:20:36 -07006046 SCTP_INC_STATS(SCTP_MIB_INORDERCHUNKS);
Vlad Yasevichf1751c52009-09-04 18:21:03 -04006047 ordered = 1;
6048 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07006049
6050 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
6051 *
6052 * If an endpoint receive a DATA chunk with an invalid stream
6053 * identifier, it shall acknowledge the reception of the DATA chunk
6054 * following the normal procedure, immediately send an ERROR chunk
6055 * with cause set to "Invalid Stream Identifier" (See Section 3.3.10)
6056 * and discard the DATA chunk.
6057 */
Vlad Yasevichf1751c52009-09-04 18:21:03 -04006058 sid = ntohs(data_hdr->stream);
6059 if (sid >= asoc->c.sinit_max_instreams) {
Vlad Yasevich3888e9e2008-07-08 02:28:39 -07006060 /* Mark tsn as received even though we drop it */
6061 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_TSN, SCTP_U32(tsn));
6062
Linus Torvalds1da177e2005-04-16 15:20:36 -07006063 err = sctp_make_op_error(asoc, chunk, SCTP_ERROR_INV_STRM,
6064 &data_hdr->stream,
Vlad Yasevich6383cfb2009-11-23 15:53:56 -05006065 sizeof(data_hdr->stream),
6066 sizeof(u16));
Linus Torvalds1da177e2005-04-16 15:20:36 -07006067 if (err)
6068 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
6069 SCTP_CHUNK(err));
6070 return SCTP_IERROR_BAD_STREAM;
6071 }
6072
Vlad Yasevichf1751c52009-09-04 18:21:03 -04006073 /* Check to see if the SSN is possible for this TSN.
6074 * The biggest gap we can record is 4K wide. Since SSNs wrap
6075 * at an unsigned short, there is no way that an SSN can
6076 * wrap and for a valid TSN. We can simply check if the current
6077 * SSN is smaller then the next expected one. If it is, it wrapped
6078 * and is invalid.
6079 */
6080 ssn = ntohs(data_hdr->ssn);
6081 if (ordered && SSN_lt(ssn, sctp_ssn_peek(&asoc->ssnmap->in, sid))) {
6082 return SCTP_IERROR_PROTO_VIOLATION;
6083 }
6084
Linus Torvalds1da177e2005-04-16 15:20:36 -07006085 /* Send the data up to the user. Note: Schedule the
6086 * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK
6087 * chunk needs the updated rwnd.
6088 */
6089 sctp_add_cmd_sf(commands, deliver, SCTP_CHUNK(chunk));
6090
6091 return SCTP_IERROR_NO_ERROR;
6092}