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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* SCTP kernel reference Implementation
2 * (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 *
8 * This file is part of the SCTP kernel reference Implementation
9 *
10 * This is part of the SCTP Linux Kernel Reference Implementation.
11 *
12 * These are the state functions for the state machine.
13 *
14 * The SCTP reference implementation is free software;
15 * you can redistribute it and/or modify it under the terms of
16 * the GNU General Public License as published by
17 * the Free Software Foundation; either version 2, or (at your option)
18 * any later version.
19 *
20 * The SCTP reference implementation is distributed in the hope that it
21 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
22 * ************************
23 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
24 * See the GNU General Public License for more details.
25 *
26 * You should have received a copy of the GNU General Public License
27 * along with GNU CC; see the file COPYING. If not, write to
28 * the Free Software Foundation, 59 Temple Place - Suite 330,
29 * Boston, MA 02111-1307, USA.
30 *
31 * Please send any bug reports or fixes you make to the
32 * email address(es):
33 * lksctp developers <lksctp-developers@lists.sourceforge.net>
34 *
35 * Or submit a bug report through the following website:
36 * http://www.sf.net/projects/lksctp
37 *
38 * Written or modified by:
39 * La Monte H.P. Yarroll <piggy@acm.org>
40 * Karl Knutson <karl@athena.chicago.il.us>
41 * Mathew Kotowsky <kotowsky@sctp.org>
42 * Sridhar Samudrala <samudrala@us.ibm.com>
43 * Jon Grimm <jgrimm@us.ibm.com>
44 * Hui Huang <hui.huang@nokia.com>
45 * Dajiang Zhang <dajiang.zhang@nokia.com>
46 * Daisy Chang <daisyc@us.ibm.com>
47 * Ardelle Fan <ardelle.fan@intel.com>
48 * Ryan Layer <rmlayer@us.ibm.com>
49 * Kevin Gao <kevin.gao@intel.com>
50 *
51 * Any bugs reported given to us we will try to fix... any fixes shared will
52 * be incorporated into the next SCTP release.
53 */
54
55#include <linux/types.h>
56#include <linux/kernel.h>
57#include <linux/ip.h>
58#include <linux/ipv6.h>
59#include <linux/net.h>
60#include <linux/inet.h>
61#include <net/sock.h>
62#include <net/inet_ecn.h>
63#include <linux/skbuff.h>
64#include <net/sctp/sctp.h>
65#include <net/sctp/sm.h>
66#include <net/sctp/structs.h>
67
68static struct sctp_packet *sctp_abort_pkt_new(const struct sctp_endpoint *ep,
69 const struct sctp_association *asoc,
70 struct sctp_chunk *chunk,
71 const void *payload,
72 size_t paylen);
73static int sctp_eat_data(const struct sctp_association *asoc,
74 struct sctp_chunk *chunk,
75 sctp_cmd_seq_t *commands);
76static struct sctp_packet *sctp_ootb_pkt_new(const struct sctp_association *asoc,
77 const struct sctp_chunk *chunk);
78static void sctp_send_stale_cookie_err(const struct sctp_endpoint *ep,
79 const struct sctp_association *asoc,
80 const struct sctp_chunk *chunk,
81 sctp_cmd_seq_t *commands,
82 struct sctp_chunk *err_chunk);
83static sctp_disposition_t sctp_sf_do_5_2_6_stale(const struct sctp_endpoint *ep,
84 const struct sctp_association *asoc,
85 const sctp_subtype_t type,
86 void *arg,
87 sctp_cmd_seq_t *commands);
88static sctp_disposition_t sctp_sf_shut_8_4_5(const struct sctp_endpoint *ep,
89 const struct sctp_association *asoc,
90 const sctp_subtype_t type,
91 void *arg,
92 sctp_cmd_seq_t *commands);
Vlad Yasevichece25df2007-09-07 16:30:54 -040093static sctp_disposition_t sctp_sf_tabort_8_4_8(const struct sctp_endpoint *ep,
94 const struct sctp_association *asoc,
95 const sctp_subtype_t type,
96 void *arg,
97 sctp_cmd_seq_t *commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -070098static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk);
99
Adrian Bunk52c1da32005-06-23 22:05:33 -0700100static sctp_disposition_t sctp_stop_t1_and_abort(sctp_cmd_seq_t *commands,
Al Virof94c0192006-11-20 17:00:25 -0800101 __be16 error, int sk_err,
Adrian Bunk52c1da32005-06-23 22:05:33 -0700102 const struct sctp_association *asoc,
103 struct sctp_transport *transport);
104
Wei Yongjunaecedea2007-08-02 16:57:44 +0800105static sctp_disposition_t sctp_sf_abort_violation(
Vlad Yasevichece25df2007-09-07 16:30:54 -0400106 const struct sctp_endpoint *ep,
Wei Yongjunaecedea2007-08-02 16:57:44 +0800107 const struct sctp_association *asoc,
108 void *arg,
109 sctp_cmd_seq_t *commands,
110 const __u8 *payload,
111 const size_t paylen);
112
Adrian Bunk52c1da32005-06-23 22:05:33 -0700113static sctp_disposition_t sctp_sf_violation_chunklen(
114 const struct sctp_endpoint *ep,
115 const struct sctp_association *asoc,
116 const sctp_subtype_t type,
117 void *arg,
118 sctp_cmd_seq_t *commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119
Wei Yongjun6f4c6182007-09-19 17:19:52 +0800120static sctp_disposition_t sctp_sf_violation_paramlen(
121 const struct sctp_endpoint *ep,
122 const struct sctp_association *asoc,
123 const sctp_subtype_t type,
124 void *arg,
125 sctp_cmd_seq_t *commands);
126
Wei Yongjunaecedea2007-08-02 16:57:44 +0800127static sctp_disposition_t sctp_sf_violation_ctsn(
128 const struct sctp_endpoint *ep,
129 const struct sctp_association *asoc,
130 const sctp_subtype_t type,
131 void *arg,
132 sctp_cmd_seq_t *commands);
133
Vlad Yasevichece25df2007-09-07 16:30:54 -0400134static sctp_disposition_t sctp_sf_violation_chunk(
135 const struct sctp_endpoint *ep,
136 const struct sctp_association *asoc,
137 const sctp_subtype_t type,
138 void *arg,
139 sctp_cmd_seq_t *commands);
140
Vlad Yasevichbbd0d592007-10-03 17:51:34 -0700141static sctp_ierror_t sctp_sf_authenticate(const struct sctp_endpoint *ep,
142 const struct sctp_association *asoc,
143 const sctp_subtype_t type,
144 struct sctp_chunk *chunk);
145
Vlad Yasevich75205f42007-12-20 14:12:59 -0800146static sctp_disposition_t __sctp_sf_do_9_1_abort(const struct sctp_endpoint *ep,
147 const struct sctp_association *asoc,
148 const sctp_subtype_t type,
149 void *arg,
150 sctp_cmd_seq_t *commands);
151
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152/* Small helper function that checks if the chunk length
153 * is of the appropriate length. The 'required_length' argument
154 * is set to be the size of a specific chunk we are testing.
155 * Return Values: 1 = Valid length
156 * 0 = Invalid length
157 *
158 */
159static inline int
160sctp_chunk_length_valid(struct sctp_chunk *chunk,
161 __u16 required_length)
162{
163 __u16 chunk_length = ntohs(chunk->chunk_hdr->length);
164
165 if (unlikely(chunk_length < required_length))
166 return 0;
167
168 return 1;
169}
170
171/**********************************************************
172 * These are the state functions for handling chunk events.
173 **********************************************************/
174
175/*
176 * Process the final SHUTDOWN COMPLETE.
177 *
178 * Section: 4 (C) (diagram), 9.2
179 * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify
180 * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be
181 * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint
182 * should stop the T2-shutdown timer and remove all knowledge of the
183 * association (and thus the association enters the CLOSED state).
184 *
Jerome Forissier047a2422005-04-28 11:58:43 -0700185 * Verification Tag: 8.5.1(C), sctpimpguide 2.41.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186 * C) Rules for packet carrying SHUTDOWN COMPLETE:
187 * ...
Jerome Forissier047a2422005-04-28 11:58:43 -0700188 * - The receiver of a SHUTDOWN COMPLETE shall accept the packet
189 * if the Verification Tag field of the packet matches its own tag and
190 * the T bit is not set
191 * OR
192 * it is set to its peer's tag and the T bit is set in the Chunk
193 * Flags.
194 * Otherwise, the receiver MUST silently discard the packet
195 * and take no further action. An endpoint MUST ignore the
196 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197 *
198 * Inputs
199 * (endpoint, asoc, chunk)
200 *
201 * Outputs
202 * (asoc, reply_msg, msg_up, timers, counters)
203 *
204 * The return value is the disposition of the chunk.
205 */
206sctp_disposition_t sctp_sf_do_4_C(const struct sctp_endpoint *ep,
207 const struct sctp_association *asoc,
208 const sctp_subtype_t type,
209 void *arg,
210 sctp_cmd_seq_t *commands)
211{
212 struct sctp_chunk *chunk = arg;
213 struct sctp_ulpevent *ev;
214
Vlad Yasevichece25df2007-09-07 16:30:54 -0400215 if (!sctp_vtag_verify_either(chunk, asoc))
216 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
217
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 /* RFC 2960 6.10 Bundling
219 *
220 * An endpoint MUST NOT bundle INIT, INIT ACK or
221 * SHUTDOWN COMPLETE with any other chunks.
222 */
223 if (!chunk->singleton)
Vlad Yasevichece25df2007-09-07 16:30:54 -0400224 return sctp_sf_violation_chunk(ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225
Vlad Yasevichece25df2007-09-07 16:30:54 -0400226 /* Make sure that the SHUTDOWN_COMPLETE chunk has a valid length. */
227 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
228 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
229 commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230
231 /* RFC 2960 10.2 SCTP-to-ULP
232 *
233 * H) SHUTDOWN COMPLETE notification
234 *
235 * When SCTP completes the shutdown procedures (section 9.2) this
236 * notification is passed to the upper layer.
237 */
238 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
Vlad Yasevicha5a35e72007-03-23 11:34:08 -0700239 0, 0, 0, NULL, GFP_ATOMIC);
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700240 if (ev)
241 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900242 SCTP_ULPEVENT(ev));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243
244 /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint
245 * will verify that it is in SHUTDOWN-ACK-SENT state, if it is
246 * not the chunk should be discarded. If the endpoint is in
247 * the SHUTDOWN-ACK-SENT state the endpoint should stop the
248 * T2-shutdown timer and remove all knowledge of the
249 * association (and thus the association enters the CLOSED
250 * state).
251 */
252 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
253 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
254
255 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
256 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
257
258 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
259 SCTP_STATE(SCTP_STATE_CLOSED));
260
261 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
262 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
263
264 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
265
266 return SCTP_DISPOSITION_DELETE_TCB;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267}
268
269/*
270 * Respond to a normal INIT chunk.
271 * We are the side that is being asked for an association.
272 *
273 * Section: 5.1 Normal Establishment of an Association, B
274 * B) "Z" shall respond immediately with an INIT ACK chunk. The
275 * destination IP address of the INIT ACK MUST be set to the source
276 * IP address of the INIT to which this INIT ACK is responding. In
277 * the response, besides filling in other parameters, "Z" must set the
278 * Verification Tag field to Tag_A, and also provide its own
279 * Verification Tag (Tag_Z) in the Initiate Tag field.
280 *
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900281 * Verification Tag: Must be 0.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282 *
283 * Inputs
284 * (endpoint, asoc, chunk)
285 *
286 * Outputs
287 * (asoc, reply_msg, msg_up, timers, counters)
288 *
289 * The return value is the disposition of the chunk.
290 */
291sctp_disposition_t sctp_sf_do_5_1B_init(const struct sctp_endpoint *ep,
292 const struct sctp_association *asoc,
293 const sctp_subtype_t type,
294 void *arg,
295 sctp_cmd_seq_t *commands)
296{
297 struct sctp_chunk *chunk = arg;
298 struct sctp_chunk *repl;
299 struct sctp_association *new_asoc;
300 struct sctp_chunk *err_chunk;
301 struct sctp_packet *packet;
302 sctp_unrecognized_param_t *unk_param;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303 int len;
304
305 /* 6.10 Bundling
306 * An endpoint MUST NOT bundle INIT, INIT ACK or
307 * SHUTDOWN COMPLETE with any other chunks.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900308 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700309 * IG Section 2.11.2
310 * Furthermore, we require that the receiver of an INIT chunk MUST
311 * enforce these rules by silently discarding an arriving packet
312 * with an INIT chunk that is bundled with other chunks.
313 */
314 if (!chunk->singleton)
315 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
316
317 /* If the packet is an OOTB packet which is temporarily on the
318 * control endpoint, respond with an ABORT.
319 */
320 if (ep == sctp_sk((sctp_get_ctl_sock()))->ep)
321 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
322
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900324 * Tag.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325 */
326 if (chunk->sctp_hdr->vtag != 0)
327 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
328
329 /* Make sure that the INIT chunk has a valid length.
330 * Normally, this would cause an ABORT with a Protocol Violation
331 * error, but since we don't have an association, we'll
332 * just discard the packet.
333 */
334 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
335 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
336
337 /* Verify the INIT chunk before processing it. */
338 err_chunk = NULL;
339 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
340 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
341 &err_chunk)) {
342 /* This chunk contains fatal error. It is to be discarded.
343 * Send an ABORT, with causes if there is any.
344 */
345 if (err_chunk) {
346 packet = sctp_abort_pkt_new(ep, asoc, arg,
347 (__u8 *)(err_chunk->chunk_hdr) +
348 sizeof(sctp_chunkhdr_t),
349 ntohs(err_chunk->chunk_hdr->length) -
350 sizeof(sctp_chunkhdr_t));
351
352 sctp_chunk_free(err_chunk);
353
354 if (packet) {
355 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
356 SCTP_PACKET(packet));
357 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
358 return SCTP_DISPOSITION_CONSUME;
359 } else {
360 return SCTP_DISPOSITION_NOMEM;
361 }
362 } else {
363 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg,
364 commands);
365 }
366 }
367
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900368 /* Grab the INIT header. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369 chunk->subh.init_hdr = (sctp_inithdr_t *)chunk->skb->data;
370
371 /* Tag the variable length parameters. */
372 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
373
374 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
375 if (!new_asoc)
376 goto nomem;
377
378 /* The call, sctp_process_init(), can fail on memory allocation. */
379 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
380 sctp_source(chunk),
381 (sctp_init_chunk_t *)chunk->chunk_hdr,
382 GFP_ATOMIC))
383 goto nomem_init;
384
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
386
387 /* If there are errors need to be reported for unknown parameters,
388 * make sure to reserve enough room in the INIT ACK for them.
389 */
390 len = 0;
391 if (err_chunk)
392 len = ntohs(err_chunk->chunk_hdr->length) -
393 sizeof(sctp_chunkhdr_t);
394
395 if (sctp_assoc_set_bind_addr_from_ep(new_asoc, GFP_ATOMIC) < 0)
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700396 goto nomem_init;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700397
398 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
399 if (!repl)
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700400 goto nomem_init;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700401
402 /* If there are errors need to be reported for unknown parameters,
403 * include them in the outgoing INIT ACK as "Unrecognized parameter"
404 * parameter.
405 */
406 if (err_chunk) {
407 /* Get the "Unrecognized parameter" parameter(s) out of the
408 * ERROR chunk generated by sctp_verify_init(). Since the
409 * error cause code for "unknown parameter" and the
410 * "Unrecognized parameter" type is the same, we can
411 * construct the parameters in INIT ACK by copying the
412 * ERROR causes over.
413 */
414 unk_param = (sctp_unrecognized_param_t *)
415 ((__u8 *)(err_chunk->chunk_hdr) +
416 sizeof(sctp_chunkhdr_t));
417 /* Replace the cause code with the "Unrecognized parameter"
418 * parameter type.
419 */
420 sctp_addto_chunk(repl, len, unk_param);
421 sctp_chunk_free(err_chunk);
422 }
423
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700424 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
425
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
427
428 /*
429 * Note: After sending out INIT ACK with the State Cookie parameter,
430 * "Z" MUST NOT allocate any resources, nor keep any states for the
431 * new association. Otherwise, "Z" will be vulnerable to resource
432 * attacks.
433 */
434 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
435
436 return SCTP_DISPOSITION_DELETE_TCB;
437
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438nomem_init:
439 sctp_association_free(new_asoc);
440nomem:
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700441 if (err_chunk)
442 sctp_chunk_free(err_chunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443 return SCTP_DISPOSITION_NOMEM;
444}
445
446/*
447 * Respond to a normal INIT ACK chunk.
448 * We are the side that is initiating the association.
449 *
450 * Section: 5.1 Normal Establishment of an Association, C
451 * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init
452 * timer and leave COOKIE-WAIT state. "A" shall then send the State
453 * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start
454 * the T1-cookie timer, and enter the COOKIE-ECHOED state.
455 *
456 * Note: The COOKIE ECHO chunk can be bundled with any pending outbound
457 * DATA chunks, but it MUST be the first chunk in the packet and
458 * until the COOKIE ACK is returned the sender MUST NOT send any
459 * other packets to the peer.
460 *
461 * Verification Tag: 3.3.3
462 * If the value of the Initiate Tag in a received INIT ACK chunk is
463 * found to be 0, the receiver MUST treat it as an error and close the
464 * association by transmitting an ABORT.
465 *
466 * Inputs
467 * (endpoint, asoc, chunk)
468 *
469 * Outputs
470 * (asoc, reply_msg, msg_up, timers, counters)
471 *
472 * The return value is the disposition of the chunk.
473 */
474sctp_disposition_t sctp_sf_do_5_1C_ack(const struct sctp_endpoint *ep,
475 const struct sctp_association *asoc,
476 const sctp_subtype_t type,
477 void *arg,
478 sctp_cmd_seq_t *commands)
479{
480 struct sctp_chunk *chunk = arg;
481 sctp_init_chunk_t *initchunk;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700482 struct sctp_chunk *err_chunk;
483 struct sctp_packet *packet;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484
485 if (!sctp_vtag_verify(chunk, asoc))
486 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
487
Linus Torvalds1da177e2005-04-16 15:20:36 -0700488 /* 6.10 Bundling
489 * An endpoint MUST NOT bundle INIT, INIT ACK or
490 * SHUTDOWN COMPLETE with any other chunks.
491 */
492 if (!chunk->singleton)
Vlad Yasevichece25df2007-09-07 16:30:54 -0400493 return sctp_sf_violation_chunk(ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494
Vlad Yasevichece25df2007-09-07 16:30:54 -0400495 /* Make sure that the INIT-ACK chunk has a valid length */
496 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_initack_chunk_t)))
497 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
498 commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700499 /* Grab the INIT header. */
500 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
501
Linus Torvalds1da177e2005-04-16 15:20:36 -0700502 /* Verify the INIT chunk before processing it. */
503 err_chunk = NULL;
504 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
505 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
506 &err_chunk)) {
507
Vlad Yasevich853f4b52008-01-20 06:10:46 -0800508 sctp_error_t error = SCTP_ERROR_NO_RESOURCE;
509
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510 /* This chunk contains fatal error. It is to be discarded.
Vlad Yasevichd6701192007-12-20 14:13:31 -0800511 * Send an ABORT, with causes. If there are no causes,
512 * then there wasn't enough memory. Just terminate
513 * the association.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514 */
515 if (err_chunk) {
516 packet = sctp_abort_pkt_new(ep, asoc, arg,
517 (__u8 *)(err_chunk->chunk_hdr) +
518 sizeof(sctp_chunkhdr_t),
519 ntohs(err_chunk->chunk_hdr->length) -
520 sizeof(sctp_chunkhdr_t));
521
522 sctp_chunk_free(err_chunk);
523
524 if (packet) {
525 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
526 SCTP_PACKET(packet));
527 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700528 error = SCTP_ERROR_INV_PARAM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700529 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700530 }
Vlad Yasevichbbd0d592007-10-03 17:51:34 -0700531
532 /* SCTP-AUTH, Section 6.3:
533 * It should be noted that if the receiver wants to tear
534 * down an association in an authenticated way only, the
535 * handling of malformed packets should not result in
536 * tearing down the association.
537 *
538 * This means that if we only want to abort associations
539 * in an authenticated way (i.e AUTH+ABORT), then we
Oliver Pinterac461a02008-02-03 17:52:41 +0200540 * can't destroy this association just becuase the packet
Vlad Yasevichbbd0d592007-10-03 17:51:34 -0700541 * was malformed.
542 */
543 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
544 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
545
546 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700547 return sctp_stop_t1_and_abort(commands, error, ECONNREFUSED,
548 asoc, chunk->transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549 }
550
551 /* Tag the variable length parameters. Note that we never
552 * convert the parameters in an INIT chunk.
553 */
554 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
555
556 initchunk = (sctp_init_chunk_t *) chunk->chunk_hdr;
557
558 sctp_add_cmd_sf(commands, SCTP_CMD_PEER_INIT,
559 SCTP_PEER_INIT(initchunk));
560
Frank Filz3f7a87d2005-06-20 13:14:57 -0700561 /* Reset init error count upon receipt of INIT-ACK. */
562 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
563
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564 /* 5.1 C) "A" shall stop the T1-init timer and leave
565 * COOKIE-WAIT state. "A" shall then ... start the T1-cookie
566 * timer, and enter the COOKIE-ECHOED state.
567 */
568 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
569 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
570 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
571 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
572 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
573 SCTP_STATE(SCTP_STATE_COOKIE_ECHOED));
574
Vlad Yasevich730fc3d2007-09-16 19:32:11 -0700575 /* SCTP-AUTH: genereate the assocition shared keys so that
576 * we can potentially signe the COOKIE-ECHO.
577 */
578 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_SHKEY, SCTP_NULL());
579
Linus Torvalds1da177e2005-04-16 15:20:36 -0700580 /* 5.1 C) "A" shall then send the State Cookie received in the
581 * INIT ACK chunk in a COOKIE ECHO chunk, ...
582 */
583 /* If there is any errors to report, send the ERROR chunk generated
584 * for unknown parameters as well.
585 */
586 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_COOKIE_ECHO,
587 SCTP_CHUNK(err_chunk));
588
589 return SCTP_DISPOSITION_CONSUME;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590}
591
592/*
593 * Respond to a normal COOKIE ECHO chunk.
594 * We are the side that is being asked for an association.
595 *
596 * Section: 5.1 Normal Establishment of an Association, D
597 * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply
598 * with a COOKIE ACK chunk after building a TCB and moving to
599 * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with
600 * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK
601 * chunk MUST be the first chunk in the packet.
602 *
603 * IMPLEMENTATION NOTE: An implementation may choose to send the
604 * Communication Up notification to the SCTP user upon reception
605 * of a valid COOKIE ECHO chunk.
606 *
607 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
608 * D) Rules for packet carrying a COOKIE ECHO
609 *
610 * - When sending a COOKIE ECHO, the endpoint MUST use the value of the
611 * Initial Tag received in the INIT ACK.
612 *
613 * - The receiver of a COOKIE ECHO follows the procedures in Section 5.
614 *
615 * Inputs
616 * (endpoint, asoc, chunk)
617 *
618 * Outputs
619 * (asoc, reply_msg, msg_up, timers, counters)
620 *
621 * The return value is the disposition of the chunk.
622 */
623sctp_disposition_t sctp_sf_do_5_1D_ce(const struct sctp_endpoint *ep,
624 const struct sctp_association *asoc,
625 const sctp_subtype_t type, void *arg,
626 sctp_cmd_seq_t *commands)
627{
628 struct sctp_chunk *chunk = arg;
629 struct sctp_association *new_asoc;
630 sctp_init_chunk_t *peer_init;
631 struct sctp_chunk *repl;
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700632 struct sctp_ulpevent *ev, *ai_ev = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633 int error = 0;
634 struct sctp_chunk *err_chk_p;
Vlad Yasevich609ee462007-08-31 03:10:59 +0900635 struct sock *sk;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700636
637 /* If the packet is an OOTB packet which is temporarily on the
638 * control endpoint, respond with an ABORT.
639 */
640 if (ep == sctp_sk((sctp_get_ctl_sock()))->ep)
Vlad Yasevichece25df2007-09-07 16:30:54 -0400641 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700642
643 /* Make sure that the COOKIE_ECHO chunk has a valid length.
644 * In this case, we check that we have enough for at least a
645 * chunk header. More detailed verification is done
646 * in sctp_unpack_cookie().
647 */
648 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
649 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
650
Vlad Yasevich609ee462007-08-31 03:10:59 +0900651 /* If the endpoint is not listening or if the number of associations
652 * on the TCP-style socket exceed the max backlog, respond with an
653 * ABORT.
654 */
655 sk = ep->base.sk;
656 if (!sctp_sstate(sk, LISTENING) ||
657 (sctp_style(sk, TCP) && sk_acceptq_is_full(sk)))
658 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
659
Linus Torvalds1da177e2005-04-16 15:20:36 -0700660 /* "Decode" the chunk. We have no optional parameters so we
661 * are in good shape.
662 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900663 chunk->subh.cookie_hdr =
Linus Torvalds1da177e2005-04-16 15:20:36 -0700664 (struct sctp_signed_cookie *)chunk->skb->data;
Sridhar Samudrala62b08082006-05-05 17:04:43 -0700665 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
666 sizeof(sctp_chunkhdr_t)))
667 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668
669 /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
670 * "Z" will reply with a COOKIE ACK chunk after building a TCB
671 * and moving to the ESTABLISHED state.
672 */
673 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
674 &err_chk_p);
675
676 /* FIXME:
677 * If the re-build failed, what is the proper error path
678 * from here?
679 *
680 * [We should abort the association. --piggy]
681 */
682 if (!new_asoc) {
683 /* FIXME: Several errors are possible. A bad cookie should
684 * be silently discarded, but think about logging it too.
685 */
686 switch (error) {
687 case -SCTP_IERROR_NOMEM:
688 goto nomem;
689
690 case -SCTP_IERROR_STALE_COOKIE:
691 sctp_send_stale_cookie_err(ep, asoc, chunk, commands,
692 err_chk_p);
693 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
694
695 case -SCTP_IERROR_BAD_SIG:
696 default:
697 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700698 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700699 }
700
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700702 /* Delay state machine commands until later.
703 *
704 * Re-build the bind address for the association is done in
Linus Torvalds1da177e2005-04-16 15:20:36 -0700705 * the sctp_unpack_cookie() already.
706 */
707 /* This is a brand-new association, so these are not yet side
708 * effects--it is safe to run them here.
709 */
710 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
711
712 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
Al Viro6a1e5f32006-11-20 17:12:25 -0800713 &chunk->subh.cookie_hdr->c.peer_addr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714 peer_init, GFP_ATOMIC))
715 goto nomem_init;
716
Vlad Yasevich730fc3d2007-09-16 19:32:11 -0700717 /* SCTP-AUTH: Now that we've populate required fields in
718 * sctp_process_init, set up the assocaition shared keys as
719 * necessary so that we can potentially authenticate the ACK
720 */
721 error = sctp_auth_asoc_init_active_key(new_asoc, GFP_ATOMIC);
722 if (error)
723 goto nomem_init;
724
Vlad Yasevichbbd0d592007-10-03 17:51:34 -0700725 /* SCTP-AUTH: auth_chunk pointer is only set when the cookie-echo
726 * is supposed to be authenticated and we have to do delayed
727 * authentication. We've just recreated the association using
728 * the information in the cookie and now it's much easier to
729 * do the authentication.
730 */
731 if (chunk->auth_chunk) {
732 struct sctp_chunk auth;
733 sctp_ierror_t ret;
734
735 /* set-up our fake chunk so that we can process it */
736 auth.skb = chunk->auth_chunk;
737 auth.asoc = chunk->asoc;
738 auth.sctp_hdr = chunk->sctp_hdr;
739 auth.chunk_hdr = (sctp_chunkhdr_t *)skb_push(chunk->auth_chunk,
740 sizeof(sctp_chunkhdr_t));
741 skb_pull(chunk->auth_chunk, sizeof(sctp_chunkhdr_t));
742 auth.transport = chunk->transport;
743
744 ret = sctp_sf_authenticate(ep, new_asoc, type, &auth);
745
746 /* We can now safely free the auth_chunk clone */
747 kfree_skb(chunk->auth_chunk);
748
749 if (ret != SCTP_IERROR_NO_ERROR) {
750 sctp_association_free(new_asoc);
751 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
752 }
753 }
754
Linus Torvalds1da177e2005-04-16 15:20:36 -0700755 repl = sctp_make_cookie_ack(new_asoc, chunk);
756 if (!repl)
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700757 goto nomem_init;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700758
759 /* RFC 2960 5.1 Normal Establishment of an Association
760 *
761 * D) IMPLEMENTATION NOTE: An implementation may choose to
762 * send the Communication Up notification to the SCTP user
763 * upon reception of a valid COOKIE ECHO chunk.
764 */
765 ev = sctp_ulpevent_make_assoc_change(new_asoc, 0, SCTP_COMM_UP, 0,
766 new_asoc->c.sinit_num_ostreams,
767 new_asoc->c.sinit_max_instreams,
Vlad Yasevicha5a35e72007-03-23 11:34:08 -0700768 NULL, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700769 if (!ev)
770 goto nomem_ev;
771
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900772 /* Sockets API Draft Section 5.3.1.6
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -0800773 * When a peer sends a Adaptation Layer Indication parameter , SCTP
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774 * delivers this notification to inform the application that of the
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -0800775 * peers requested adaptation layer.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700776 */
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -0800777 if (new_asoc->peer.adaptation_ind) {
778 ai_ev = sctp_ulpevent_make_adaptation_indication(new_asoc,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700779 GFP_ATOMIC);
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700780 if (!ai_ev)
781 goto nomem_aiev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700782 }
783
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700784 /* Add all the state machine commands now since we've created
785 * everything. This way we don't introduce memory corruptions
786 * during side-effect processing and correclty count established
787 * associations.
788 */
789 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
790 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
791 SCTP_STATE(SCTP_STATE_ESTABLISHED));
792 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
793 SCTP_INC_STATS(SCTP_MIB_PASSIVEESTABS);
794 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
795
796 if (new_asoc->autoclose)
797 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
798 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
799
800 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
801
802 /* This will send the COOKIE ACK */
803 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
804
805 /* Queue the ASSOC_CHANGE event */
806 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
807
808 /* Send up the Adaptation Layer Indication event */
809 if (ai_ev)
810 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
811 SCTP_ULPEVENT(ai_ev));
812
Linus Torvalds1da177e2005-04-16 15:20:36 -0700813 return SCTP_DISPOSITION_CONSUME;
814
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700815nomem_aiev:
816 sctp_ulpevent_free(ev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700817nomem_ev:
818 sctp_chunk_free(repl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700819nomem_init:
820 sctp_association_free(new_asoc);
821nomem:
822 return SCTP_DISPOSITION_NOMEM;
823}
824
825/*
826 * Respond to a normal COOKIE ACK chunk.
827 * We are the side that is being asked for an association.
828 *
829 * RFC 2960 5.1 Normal Establishment of an Association
830 *
831 * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the
832 * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie
833 * timer. It may also notify its ULP about the successful
834 * establishment of the association with a Communication Up
835 * notification (see Section 10).
836 *
837 * Verification Tag:
838 * Inputs
839 * (endpoint, asoc, chunk)
840 *
841 * Outputs
842 * (asoc, reply_msg, msg_up, timers, counters)
843 *
844 * The return value is the disposition of the chunk.
845 */
846sctp_disposition_t sctp_sf_do_5_1E_ca(const struct sctp_endpoint *ep,
847 const struct sctp_association *asoc,
848 const sctp_subtype_t type, void *arg,
849 sctp_cmd_seq_t *commands)
850{
851 struct sctp_chunk *chunk = arg;
852 struct sctp_ulpevent *ev;
853
854 if (!sctp_vtag_verify(chunk, asoc))
855 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
856
857 /* Verify that the chunk length for the COOKIE-ACK is OK.
858 * If we don't do this, any bundled chunks may be junked.
859 */
860 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
861 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
862 commands);
863
864 /* Reset init error count upon receipt of COOKIE-ACK,
865 * to avoid problems with the managemement of this
866 * counter in stale cookie situations when a transition back
867 * from the COOKIE-ECHOED state to the COOKIE-WAIT
868 * state is performed.
869 */
Frank Filz3f7a87d2005-06-20 13:14:57 -0700870 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
Linus Torvalds1da177e2005-04-16 15:20:36 -0700871
872 /* RFC 2960 5.1 Normal Establishment of an Association
873 *
874 * E) Upon reception of the COOKIE ACK, endpoint "A" will move
875 * from the COOKIE-ECHOED state to the ESTABLISHED state,
876 * stopping the T1-cookie timer.
877 */
878 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
879 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
880 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
881 SCTP_STATE(SCTP_STATE_ESTABLISHED));
882 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
883 SCTP_INC_STATS(SCTP_MIB_ACTIVEESTABS);
884 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
885 if (asoc->autoclose)
886 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
887 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
888 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
889
890 /* It may also notify its ULP about the successful
891 * establishment of the association with a Communication Up
892 * notification (see Section 10).
893 */
894 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP,
895 0, asoc->c.sinit_num_ostreams,
896 asoc->c.sinit_max_instreams,
Vlad Yasevicha5a35e72007-03-23 11:34:08 -0700897 NULL, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700898
899 if (!ev)
900 goto nomem;
901
902 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
903
904 /* Sockets API Draft Section 5.3.1.6
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -0800905 * When a peer sends a Adaptation Layer Indication parameter , SCTP
Linus Torvalds1da177e2005-04-16 15:20:36 -0700906 * delivers this notification to inform the application that of the
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -0800907 * peers requested adaptation layer.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700908 */
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -0800909 if (asoc->peer.adaptation_ind) {
910 ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700911 if (!ev)
912 goto nomem;
913
914 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
915 SCTP_ULPEVENT(ev));
916 }
917
918 return SCTP_DISPOSITION_CONSUME;
919nomem:
920 return SCTP_DISPOSITION_NOMEM;
921}
922
923/* Generate and sendout a heartbeat packet. */
924static sctp_disposition_t sctp_sf_heartbeat(const struct sctp_endpoint *ep,
925 const struct sctp_association *asoc,
926 const sctp_subtype_t type,
927 void *arg,
928 sctp_cmd_seq_t *commands)
929{
930 struct sctp_transport *transport = (struct sctp_transport *) arg;
931 struct sctp_chunk *reply;
932 sctp_sender_hb_info_t hbinfo;
933 size_t paylen = 0;
934
935 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO;
936 hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t));
Al Viro63de08f2006-11-20 17:07:25 -0800937 hbinfo.daddr = transport->ipaddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700938 hbinfo.sent_at = jiffies;
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700939 hbinfo.hb_nonce = transport->hb_nonce;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700940
941 /* Send a heartbeat to our peer. */
942 paylen = sizeof(sctp_sender_hb_info_t);
943 reply = sctp_make_heartbeat(asoc, transport, &hbinfo, paylen);
944 if (!reply)
945 return SCTP_DISPOSITION_NOMEM;
946
947 /* Set rto_pending indicating that an RTT measurement
948 * is started with this heartbeat chunk.
949 */
950 sctp_add_cmd_sf(commands, SCTP_CMD_RTO_PENDING,
951 SCTP_TRANSPORT(transport));
952
953 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
954 return SCTP_DISPOSITION_CONSUME;
955}
956
957/* Generate a HEARTBEAT packet on the given transport. */
958sctp_disposition_t sctp_sf_sendbeat_8_3(const struct sctp_endpoint *ep,
959 const struct sctp_association *asoc,
960 const sctp_subtype_t type,
961 void *arg,
962 sctp_cmd_seq_t *commands)
963{
964 struct sctp_transport *transport = (struct sctp_transport *) arg;
965
Vlad Yasevichfd102792007-11-15 12:13:32 -0500966 if (asoc->overall_error_count > asoc->max_retrans) {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700967 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
968 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700969 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
970 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -0800971 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700972 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
973 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
974 return SCTP_DISPOSITION_DELETE_TCB;
975 }
976
977 /* Section 3.3.5.
978 * The Sender-specific Heartbeat Info field should normally include
979 * information about the sender's current time when this HEARTBEAT
980 * chunk is sent and the destination transport address to which this
981 * HEARTBEAT is sent (see Section 8.3).
982 */
983
Frank Filz52ccb8e2005-12-22 11:36:46 -0800984 if (transport->param_flags & SPP_HB_ENABLE) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700985 if (SCTP_DISPOSITION_NOMEM ==
986 sctp_sf_heartbeat(ep, asoc, type, arg,
987 commands))
988 return SCTP_DISPOSITION_NOMEM;
989 /* Set transport error counter and association error counter
990 * when sending heartbeat.
991 */
992 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_RESET,
993 SCTP_TRANSPORT(transport));
994 }
995 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMER_UPDATE,
996 SCTP_TRANSPORT(transport));
997
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900998 return SCTP_DISPOSITION_CONSUME;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700999}
1000
1001/*
1002 * Process an heartbeat request.
1003 *
1004 * Section: 8.3 Path Heartbeat
1005 * The receiver of the HEARTBEAT should immediately respond with a
1006 * HEARTBEAT ACK that contains the Heartbeat Information field copied
1007 * from the received HEARTBEAT chunk.
1008 *
1009 * Verification Tag: 8.5 Verification Tag [Normal verification]
1010 * When receiving an SCTP packet, the endpoint MUST ensure that the
1011 * value in the Verification Tag field of the received SCTP packet
1012 * matches its own Tag. If the received Verification Tag value does not
1013 * match the receiver's own tag value, the receiver shall silently
1014 * discard the packet and shall not process it any further except for
1015 * those cases listed in Section 8.5.1 below.
1016 *
1017 * Inputs
1018 * (endpoint, asoc, chunk)
1019 *
1020 * Outputs
1021 * (asoc, reply_msg, msg_up, timers, counters)
1022 *
1023 * The return value is the disposition of the chunk.
1024 */
1025sctp_disposition_t sctp_sf_beat_8_3(const struct sctp_endpoint *ep,
1026 const struct sctp_association *asoc,
1027 const sctp_subtype_t type,
1028 void *arg,
1029 sctp_cmd_seq_t *commands)
1030{
1031 struct sctp_chunk *chunk = arg;
1032 struct sctp_chunk *reply;
1033 size_t paylen = 0;
1034
1035 if (!sctp_vtag_verify(chunk, asoc))
1036 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1037
1038 /* Make sure that the HEARTBEAT chunk has a valid length. */
1039 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t)))
1040 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1041 commands);
1042
1043 /* 8.3 The receiver of the HEARTBEAT should immediately
1044 * respond with a HEARTBEAT ACK that contains the Heartbeat
1045 * Information field copied from the received HEARTBEAT chunk.
1046 */
1047 chunk->subh.hb_hdr = (sctp_heartbeathdr_t *) chunk->skb->data;
1048 paylen = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
Sridhar Samudrala62b08082006-05-05 17:04:43 -07001049 if (!pskb_pull(chunk->skb, paylen))
1050 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001051
1052 reply = sctp_make_heartbeat_ack(asoc, chunk,
1053 chunk->subh.hb_hdr, paylen);
1054 if (!reply)
1055 goto nomem;
1056
1057 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
1058 return SCTP_DISPOSITION_CONSUME;
1059
1060nomem:
1061 return SCTP_DISPOSITION_NOMEM;
1062}
1063
1064/*
1065 * Process the returning HEARTBEAT ACK.
1066 *
1067 * Section: 8.3 Path Heartbeat
1068 * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT
1069 * should clear the error counter of the destination transport
1070 * address to which the HEARTBEAT was sent, and mark the destination
1071 * transport address as active if it is not so marked. The endpoint may
1072 * optionally report to the upper layer when an inactive destination
1073 * address is marked as active due to the reception of the latest
1074 * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also
1075 * clear the association overall error count as well (as defined
1076 * in section 8.1).
1077 *
1078 * The receiver of the HEARTBEAT ACK should also perform an RTT
1079 * measurement for that destination transport address using the time
1080 * value carried in the HEARTBEAT ACK chunk.
1081 *
1082 * Verification Tag: 8.5 Verification Tag [Normal verification]
1083 *
1084 * Inputs
1085 * (endpoint, asoc, chunk)
1086 *
1087 * Outputs
1088 * (asoc, reply_msg, msg_up, timers, counters)
1089 *
1090 * The return value is the disposition of the chunk.
1091 */
1092sctp_disposition_t sctp_sf_backbeat_8_3(const struct sctp_endpoint *ep,
1093 const struct sctp_association *asoc,
1094 const sctp_subtype_t type,
1095 void *arg,
1096 sctp_cmd_seq_t *commands)
1097{
1098 struct sctp_chunk *chunk = arg;
1099 union sctp_addr from_addr;
1100 struct sctp_transport *link;
1101 sctp_sender_hb_info_t *hbinfo;
1102 unsigned long max_interval;
1103
1104 if (!sctp_vtag_verify(chunk, asoc))
1105 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1106
1107 /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */
1108 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t)))
1109 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1110 commands);
1111
1112 hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
Vladislav Yasevicha6012662006-05-19 14:25:53 -07001113 /* Make sure that the length of the parameter is what we expect */
1114 if (ntohs(hbinfo->param_hdr.length) !=
1115 sizeof(sctp_sender_hb_info_t)) {
1116 return SCTP_DISPOSITION_DISCARD;
1117 }
1118
Linus Torvalds1da177e2005-04-16 15:20:36 -07001119 from_addr = hbinfo->daddr;
Al Viro63de08f2006-11-20 17:07:25 -08001120 link = sctp_assoc_lookup_paddr(asoc, &from_addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001121
1122 /* This should never happen, but lets log it if so. */
Frank Filz3f7a87d2005-06-20 13:14:57 -07001123 if (unlikely(!link)) {
1124 if (from_addr.sa.sa_family == AF_INET6) {
Wei Yongjund99fa422007-08-27 11:19:24 +08001125 if (net_ratelimit())
1126 printk(KERN_WARNING
1127 "%s association %p could not find address "
1128 NIP6_FMT "\n",
1129 __FUNCTION__,
1130 asoc,
1131 NIP6(from_addr.v6.sin6_addr));
Frank Filz3f7a87d2005-06-20 13:14:57 -07001132 } else {
Wei Yongjund99fa422007-08-27 11:19:24 +08001133 if (net_ratelimit())
1134 printk(KERN_WARNING
1135 "%s association %p could not find address "
1136 NIPQUAD_FMT "\n",
1137 __FUNCTION__,
1138 asoc,
1139 NIPQUAD(from_addr.v4.sin_addr.s_addr));
Frank Filz3f7a87d2005-06-20 13:14:57 -07001140 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001141 return SCTP_DISPOSITION_DISCARD;
1142 }
1143
Sridhar Samudralaad8fec12006-07-21 14:48:50 -07001144 /* Validate the 64-bit random nonce. */
1145 if (hbinfo->hb_nonce != link->hb_nonce)
1146 return SCTP_DISPOSITION_DISCARD;
1147
Frank Filz52ccb8e2005-12-22 11:36:46 -08001148 max_interval = link->hbinterval + link->rto;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001149
1150 /* Check if the timestamp looks valid. */
1151 if (time_after(hbinfo->sent_at, jiffies) ||
1152 time_after(jiffies, hbinfo->sent_at + max_interval)) {
Joe Perches9ee46f12007-11-19 23:47:47 -08001153 SCTP_DEBUG_PRINTK("%s: HEARTBEAT ACK with invalid timestamp "
Linus Torvalds1da177e2005-04-16 15:20:36 -07001154 "received for transport: %p\n",
1155 __FUNCTION__, link);
1156 return SCTP_DISPOSITION_DISCARD;
1157 }
1158
1159 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of
1160 * the HEARTBEAT should clear the error counter of the
1161 * destination transport address to which the HEARTBEAT was
1162 * sent and mark the destination transport address as active if
1163 * it is not so marked.
1164 */
1165 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_ON, SCTP_TRANSPORT(link));
1166
1167 return SCTP_DISPOSITION_CONSUME;
1168}
1169
1170/* Helper function to send out an abort for the restart
1171 * condition.
1172 */
1173static int sctp_sf_send_restart_abort(union sctp_addr *ssa,
1174 struct sctp_chunk *init,
1175 sctp_cmd_seq_t *commands)
1176{
1177 int len;
1178 struct sctp_packet *pkt;
1179 union sctp_addr_param *addrparm;
1180 struct sctp_errhdr *errhdr;
1181 struct sctp_endpoint *ep;
1182 char buffer[sizeof(struct sctp_errhdr)+sizeof(union sctp_addr_param)];
1183 struct sctp_af *af = sctp_get_af_specific(ssa->v4.sin_family);
1184
1185 /* Build the error on the stack. We are way to malloc crazy
1186 * throughout the code today.
1187 */
1188 errhdr = (struct sctp_errhdr *)buffer;
1189 addrparm = (union sctp_addr_param *)errhdr->variable;
1190
1191 /* Copy into a parm format. */
1192 len = af->to_addr_param(ssa, addrparm);
1193 len += sizeof(sctp_errhdr_t);
1194
1195 errhdr->cause = SCTP_ERROR_RESTART;
1196 errhdr->length = htons(len);
1197
1198 /* Assign to the control socket. */
1199 ep = sctp_sk((sctp_get_ctl_sock()))->ep;
1200
1201 /* Association is NULL since this may be a restart attack and we
1202 * want to send back the attacker's vtag.
1203 */
1204 pkt = sctp_abort_pkt_new(ep, NULL, init, errhdr, len);
1205
1206 if (!pkt)
1207 goto out;
1208 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, SCTP_PACKET(pkt));
1209
1210 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
1211
1212 /* Discard the rest of the inbound packet. */
1213 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
1214
1215out:
1216 /* Even if there is no memory, treat as a failure so
1217 * the packet will get dropped.
1218 */
1219 return 0;
1220}
1221
1222/* A restart is occurring, check to make sure no new addresses
1223 * are being added as we may be under a takeover attack.
1224 */
1225static int sctp_sf_check_restart_addrs(const struct sctp_association *new_asoc,
1226 const struct sctp_association *asoc,
1227 struct sctp_chunk *init,
1228 sctp_cmd_seq_t *commands)
1229{
1230 struct sctp_transport *new_addr, *addr;
1231 struct list_head *pos, *pos2;
1232 int found;
1233
1234 /* Implementor's Guide - Sectin 5.2.2
1235 * ...
1236 * Before responding the endpoint MUST check to see if the
1237 * unexpected INIT adds new addresses to the association. If new
1238 * addresses are added to the association, the endpoint MUST respond
1239 * with an ABORT..
1240 */
1241
1242 /* Search through all current addresses and make sure
1243 * we aren't adding any new ones.
1244 */
1245 new_addr = NULL;
1246 found = 0;
1247
1248 list_for_each(pos, &new_asoc->peer.transport_addr_list) {
1249 new_addr = list_entry(pos, struct sctp_transport, transports);
1250 found = 0;
1251 list_for_each(pos2, &asoc->peer.transport_addr_list) {
1252 addr = list_entry(pos2, struct sctp_transport,
1253 transports);
Al Viro5f242a12006-11-20 17:05:23 -08001254 if (sctp_cmp_addr_exact(&new_addr->ipaddr,
1255 &addr->ipaddr)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001256 found = 1;
1257 break;
1258 }
1259 }
1260 if (!found)
1261 break;
1262 }
1263
1264 /* If a new address was added, ABORT the sender. */
1265 if (!found && new_addr) {
Al Viro7dd8a582006-11-20 17:23:25 -08001266 sctp_sf_send_restart_abort(&new_addr->ipaddr, init, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001267 }
1268
1269 /* Return success if all addresses were found. */
1270 return found;
1271}
1272
1273/* Populate the verification/tie tags based on overlapping INIT
1274 * scenario.
1275 *
1276 * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state.
1277 */
1278static void sctp_tietags_populate(struct sctp_association *new_asoc,
1279 const struct sctp_association *asoc)
1280{
1281 switch (asoc->state) {
1282
1283 /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */
1284
1285 case SCTP_STATE_COOKIE_WAIT:
1286 new_asoc->c.my_vtag = asoc->c.my_vtag;
1287 new_asoc->c.my_ttag = asoc->c.my_vtag;
1288 new_asoc->c.peer_ttag = 0;
1289 break;
1290
1291 case SCTP_STATE_COOKIE_ECHOED:
1292 new_asoc->c.my_vtag = asoc->c.my_vtag;
1293 new_asoc->c.my_ttag = asoc->c.my_vtag;
1294 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1295 break;
1296
1297 /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED,
1298 * COOKIE-WAIT and SHUTDOWN-ACK-SENT
1299 */
1300 default:
1301 new_asoc->c.my_ttag = asoc->c.my_vtag;
1302 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1303 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07001304 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001305
1306 /* Other parameters for the endpoint SHOULD be copied from the
1307 * existing parameters of the association (e.g. number of
1308 * outbound streams) into the INIT ACK and cookie.
1309 */
1310 new_asoc->rwnd = asoc->rwnd;
1311 new_asoc->c.sinit_num_ostreams = asoc->c.sinit_num_ostreams;
1312 new_asoc->c.sinit_max_instreams = asoc->c.sinit_max_instreams;
1313 new_asoc->c.initial_tsn = asoc->c.initial_tsn;
1314}
1315
1316/*
1317 * Compare vtag/tietag values to determine unexpected COOKIE-ECHO
1318 * handling action.
1319 *
1320 * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists.
1321 *
1322 * Returns value representing action to be taken. These action values
1323 * correspond to Action/Description values in RFC 2960, Table 2.
1324 */
1325static char sctp_tietags_compare(struct sctp_association *new_asoc,
1326 const struct sctp_association *asoc)
1327{
1328 /* In this case, the peer may have restarted. */
1329 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1330 (asoc->c.peer_vtag != new_asoc->c.peer_vtag) &&
1331 (asoc->c.my_vtag == new_asoc->c.my_ttag) &&
1332 (asoc->c.peer_vtag == new_asoc->c.peer_ttag))
1333 return 'A';
1334
1335 /* Collision case B. */
1336 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1337 ((asoc->c.peer_vtag != new_asoc->c.peer_vtag) ||
1338 (0 == asoc->c.peer_vtag))) {
1339 return 'B';
1340 }
1341
1342 /* Collision case D. */
1343 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1344 (asoc->c.peer_vtag == new_asoc->c.peer_vtag))
1345 return 'D';
1346
1347 /* Collision case C. */
1348 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1349 (asoc->c.peer_vtag == new_asoc->c.peer_vtag) &&
1350 (0 == new_asoc->c.my_ttag) &&
1351 (0 == new_asoc->c.peer_ttag))
1352 return 'C';
1353
1354 /* No match to any of the special cases; discard this packet. */
1355 return 'E';
1356}
1357
1358/* Common helper routine for both duplicate and simulataneous INIT
1359 * chunk handling.
1360 */
1361static sctp_disposition_t sctp_sf_do_unexpected_init(
1362 const struct sctp_endpoint *ep,
1363 const struct sctp_association *asoc,
1364 const sctp_subtype_t type,
1365 void *arg, sctp_cmd_seq_t *commands)
1366{
1367 sctp_disposition_t retval;
1368 struct sctp_chunk *chunk = arg;
1369 struct sctp_chunk *repl;
1370 struct sctp_association *new_asoc;
1371 struct sctp_chunk *err_chunk;
1372 struct sctp_packet *packet;
1373 sctp_unrecognized_param_t *unk_param;
1374 int len;
1375
1376 /* 6.10 Bundling
1377 * An endpoint MUST NOT bundle INIT, INIT ACK or
1378 * SHUTDOWN COMPLETE with any other chunks.
1379 *
1380 * IG Section 2.11.2
1381 * Furthermore, we require that the receiver of an INIT chunk MUST
1382 * enforce these rules by silently discarding an arriving packet
1383 * with an INIT chunk that is bundled with other chunks.
1384 */
1385 if (!chunk->singleton)
1386 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1387
1388 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001389 * Tag.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001390 */
1391 if (chunk->sctp_hdr->vtag != 0)
1392 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
1393
1394 /* Make sure that the INIT chunk has a valid length.
1395 * In this case, we generate a protocol violation since we have
1396 * an association established.
1397 */
1398 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
1399 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1400 commands);
1401 /* Grab the INIT header. */
1402 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
1403
1404 /* Tag the variable length parameters. */
1405 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
1406
1407 /* Verify the INIT chunk before processing it. */
1408 err_chunk = NULL;
1409 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
1410 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
1411 &err_chunk)) {
1412 /* This chunk contains fatal error. It is to be discarded.
1413 * Send an ABORT, with causes if there is any.
1414 */
1415 if (err_chunk) {
1416 packet = sctp_abort_pkt_new(ep, asoc, arg,
1417 (__u8 *)(err_chunk->chunk_hdr) +
1418 sizeof(sctp_chunkhdr_t),
1419 ntohs(err_chunk->chunk_hdr->length) -
1420 sizeof(sctp_chunkhdr_t));
1421
1422 if (packet) {
1423 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
1424 SCTP_PACKET(packet));
1425 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
1426 retval = SCTP_DISPOSITION_CONSUME;
1427 } else {
1428 retval = SCTP_DISPOSITION_NOMEM;
1429 }
1430 goto cleanup;
1431 } else {
1432 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg,
1433 commands);
1434 }
1435 }
1436
1437 /*
1438 * Other parameters for the endpoint SHOULD be copied from the
1439 * existing parameters of the association (e.g. number of
1440 * outbound streams) into the INIT ACK and cookie.
1441 * FIXME: We are copying parameters from the endpoint not the
1442 * association.
1443 */
1444 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
1445 if (!new_asoc)
1446 goto nomem;
1447
1448 /* In the outbound INIT ACK the endpoint MUST copy its current
1449 * Verification Tag and Peers Verification tag into a reserved
1450 * place (local tie-tag and per tie-tag) within the state cookie.
1451 */
1452 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
1453 sctp_source(chunk),
1454 (sctp_init_chunk_t *)chunk->chunk_hdr,
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001455 GFP_ATOMIC))
1456 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001457
1458 /* Make sure no new addresses are being added during the
1459 * restart. Do not do this check for COOKIE-WAIT state,
1460 * since there are no peer addresses to check against.
1461 * Upon return an ABORT will have been sent if needed.
1462 */
1463 if (!sctp_state(asoc, COOKIE_WAIT)) {
1464 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk,
1465 commands)) {
1466 retval = SCTP_DISPOSITION_CONSUME;
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001467 goto nomem_retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001468 }
1469 }
1470
1471 sctp_tietags_populate(new_asoc, asoc);
1472
1473 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
1474
1475 /* If there are errors need to be reported for unknown parameters,
1476 * make sure to reserve enough room in the INIT ACK for them.
1477 */
1478 len = 0;
1479 if (err_chunk) {
1480 len = ntohs(err_chunk->chunk_hdr->length) -
1481 sizeof(sctp_chunkhdr_t);
1482 }
1483
1484 if (sctp_assoc_set_bind_addr_from_ep(new_asoc, GFP_ATOMIC) < 0)
1485 goto nomem;
1486
1487 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
1488 if (!repl)
1489 goto nomem;
1490
1491 /* If there are errors need to be reported for unknown parameters,
1492 * include them in the outgoing INIT ACK as "Unrecognized parameter"
1493 * parameter.
1494 */
1495 if (err_chunk) {
1496 /* Get the "Unrecognized parameter" parameter(s) out of the
1497 * ERROR chunk generated by sctp_verify_init(). Since the
1498 * error cause code for "unknown parameter" and the
1499 * "Unrecognized parameter" type is the same, we can
1500 * construct the parameters in INIT ACK by copying the
1501 * ERROR causes over.
1502 */
1503 unk_param = (sctp_unrecognized_param_t *)
1504 ((__u8 *)(err_chunk->chunk_hdr) +
1505 sizeof(sctp_chunkhdr_t));
1506 /* Replace the cause code with the "Unrecognized parameter"
1507 * parameter type.
1508 */
1509 sctp_addto_chunk(repl, len, unk_param);
1510 }
1511
1512 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
1513 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1514
1515 /*
1516 * Note: After sending out INIT ACK with the State Cookie parameter,
1517 * "Z" MUST NOT allocate any resources for this new association.
1518 * Otherwise, "Z" will be vulnerable to resource attacks.
1519 */
1520 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
1521 retval = SCTP_DISPOSITION_CONSUME;
1522
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001523 return retval;
1524
1525nomem:
1526 retval = SCTP_DISPOSITION_NOMEM;
1527nomem_retval:
1528 if (new_asoc)
1529 sctp_association_free(new_asoc);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001530cleanup:
1531 if (err_chunk)
1532 sctp_chunk_free(err_chunk);
1533 return retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001534}
1535
1536/*
1537 * Handle simultanous INIT.
1538 * This means we started an INIT and then we got an INIT request from
1539 * our peer.
1540 *
1541 * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B)
1542 * This usually indicates an initialization collision, i.e., each
1543 * endpoint is attempting, at about the same time, to establish an
1544 * association with the other endpoint.
1545 *
1546 * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an
1547 * endpoint MUST respond with an INIT ACK using the same parameters it
1548 * sent in its original INIT chunk (including its Verification Tag,
1549 * unchanged). These original parameters are combined with those from the
1550 * newly received INIT chunk. The endpoint shall also generate a State
1551 * Cookie with the INIT ACK. The endpoint uses the parameters sent in its
1552 * INIT to calculate the State Cookie.
1553 *
1554 * After that, the endpoint MUST NOT change its state, the T1-init
1555 * timer shall be left running and the corresponding TCB MUST NOT be
1556 * destroyed. The normal procedures for handling State Cookies when
1557 * a TCB exists will resolve the duplicate INITs to a single association.
1558 *
1559 * For an endpoint that is in the COOKIE-ECHOED state it MUST populate
1560 * its Tie-Tags with the Tag information of itself and its peer (see
1561 * section 5.2.2 for a description of the Tie-Tags).
1562 *
1563 * Verification Tag: Not explicit, but an INIT can not have a valid
1564 * verification tag, so we skip the check.
1565 *
1566 * Inputs
1567 * (endpoint, asoc, chunk)
1568 *
1569 * Outputs
1570 * (asoc, reply_msg, msg_up, timers, counters)
1571 *
1572 * The return value is the disposition of the chunk.
1573 */
1574sctp_disposition_t sctp_sf_do_5_2_1_siminit(const struct sctp_endpoint *ep,
1575 const struct sctp_association *asoc,
1576 const sctp_subtype_t type,
1577 void *arg,
1578 sctp_cmd_seq_t *commands)
1579{
1580 /* Call helper to do the real work for both simulataneous and
1581 * duplicate INIT chunk handling.
1582 */
1583 return sctp_sf_do_unexpected_init(ep, asoc, type, arg, commands);
1584}
1585
1586/*
1587 * Handle duplicated INIT messages. These are usually delayed
1588 * restransmissions.
1589 *
1590 * Section: 5.2.2 Unexpected INIT in States Other than CLOSED,
1591 * COOKIE-ECHOED and COOKIE-WAIT
1592 *
1593 * Unless otherwise stated, upon reception of an unexpected INIT for
1594 * this association, the endpoint shall generate an INIT ACK with a
1595 * State Cookie. In the outbound INIT ACK the endpoint MUST copy its
1596 * current Verification Tag and peer's Verification Tag into a reserved
1597 * place within the state cookie. We shall refer to these locations as
1598 * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet
1599 * containing this INIT ACK MUST carry a Verification Tag value equal to
1600 * the Initiation Tag found in the unexpected INIT. And the INIT ACK
1601 * MUST contain a new Initiation Tag (randomly generated see Section
1602 * 5.3.1). Other parameters for the endpoint SHOULD be copied from the
1603 * existing parameters of the association (e.g. number of outbound
1604 * streams) into the INIT ACK and cookie.
1605 *
1606 * After sending out the INIT ACK, the endpoint shall take no further
1607 * actions, i.e., the existing association, including its current state,
1608 * and the corresponding TCB MUST NOT be changed.
1609 *
1610 * Note: Only when a TCB exists and the association is not in a COOKIE-
1611 * WAIT state are the Tie-Tags populated. For a normal association INIT
1612 * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be
1613 * set to 0 (indicating that no previous TCB existed). The INIT ACK and
1614 * State Cookie are populated as specified in section 5.2.1.
1615 *
1616 * Verification Tag: Not specified, but an INIT has no way of knowing
1617 * what the verification tag could be, so we ignore it.
1618 *
1619 * Inputs
1620 * (endpoint, asoc, chunk)
1621 *
1622 * Outputs
1623 * (asoc, reply_msg, msg_up, timers, counters)
1624 *
1625 * The return value is the disposition of the chunk.
1626 */
1627sctp_disposition_t sctp_sf_do_5_2_2_dupinit(const struct sctp_endpoint *ep,
1628 const struct sctp_association *asoc,
1629 const sctp_subtype_t type,
1630 void *arg,
1631 sctp_cmd_seq_t *commands)
1632{
1633 /* Call helper to do the real work for both simulataneous and
1634 * duplicate INIT chunk handling.
1635 */
1636 return sctp_sf_do_unexpected_init(ep, asoc, type, arg, commands);
1637}
1638
1639
Vlad Yasevich610ab732007-01-15 19:18:30 -08001640/*
1641 * Unexpected INIT-ACK handler.
1642 *
1643 * Section 5.2.3
1644 * If an INIT ACK received by an endpoint in any state other than the
1645 * COOKIE-WAIT state, the endpoint should discard the INIT ACK chunk.
1646 * An unexpected INIT ACK usually indicates the processing of an old or
1647 * duplicated INIT chunk.
1648*/
1649sctp_disposition_t sctp_sf_do_5_2_3_initack(const struct sctp_endpoint *ep,
1650 const struct sctp_association *asoc,
1651 const sctp_subtype_t type,
1652 void *arg, sctp_cmd_seq_t *commands)
1653{
1654 /* Per the above section, we'll discard the chunk if we have an
1655 * endpoint. If this is an OOTB INIT-ACK, treat it as such.
1656 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001657 if (ep == sctp_sk((sctp_get_ctl_sock()))->ep)
Vlad Yasevich610ab732007-01-15 19:18:30 -08001658 return sctp_sf_ootb(ep, asoc, type, arg, commands);
1659 else
1660 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
1661}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001662
1663/* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A')
1664 *
1665 * Section 5.2.4
1666 * A) In this case, the peer may have restarted.
1667 */
1668static sctp_disposition_t sctp_sf_do_dupcook_a(const struct sctp_endpoint *ep,
1669 const struct sctp_association *asoc,
1670 struct sctp_chunk *chunk,
1671 sctp_cmd_seq_t *commands,
1672 struct sctp_association *new_asoc)
1673{
1674 sctp_init_chunk_t *peer_init;
1675 struct sctp_ulpevent *ev;
1676 struct sctp_chunk *repl;
1677 struct sctp_chunk *err;
1678 sctp_disposition_t disposition;
1679
1680 /* new_asoc is a brand-new association, so these are not yet
1681 * side effects--it is safe to run them here.
1682 */
1683 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1684
1685 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
1686 sctp_source(chunk), peer_init,
1687 GFP_ATOMIC))
1688 goto nomem;
1689
1690 /* Make sure no new addresses are being added during the
1691 * restart. Though this is a pretty complicated attack
1692 * since you'd have to get inside the cookie.
1693 */
1694 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk, commands)) {
1695 return SCTP_DISPOSITION_CONSUME;
1696 }
1697
1698 /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes
1699 * the peer has restarted (Action A), it MUST NOT setup a new
1700 * association but instead resend the SHUTDOWN ACK and send an ERROR
1701 * chunk with a "Cookie Received while Shutting Down" error cause to
1702 * its peer.
1703 */
1704 if (sctp_state(asoc, SHUTDOWN_ACK_SENT)) {
1705 disposition = sctp_sf_do_9_2_reshutack(ep, asoc,
1706 SCTP_ST_CHUNK(chunk->chunk_hdr->type),
1707 chunk, commands);
1708 if (SCTP_DISPOSITION_NOMEM == disposition)
1709 goto nomem;
1710
1711 err = sctp_make_op_error(asoc, chunk,
1712 SCTP_ERROR_COOKIE_IN_SHUTDOWN,
1713 NULL, 0);
1714 if (err)
1715 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1716 SCTP_CHUNK(err));
1717
1718 return SCTP_DISPOSITION_CONSUME;
1719 }
1720
1721 /* For now, fail any unsent/unacked data. Consider the optional
1722 * choice of resending of this data.
1723 */
1724 sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_OUTQUEUE, SCTP_NULL());
1725
Linus Torvalds1da177e2005-04-16 15:20:36 -07001726 repl = sctp_make_cookie_ack(new_asoc, chunk);
1727 if (!repl)
1728 goto nomem;
1729
Linus Torvalds1da177e2005-04-16 15:20:36 -07001730 /* Report association restart to upper layer. */
1731 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_RESTART, 0,
1732 new_asoc->c.sinit_num_ostreams,
1733 new_asoc->c.sinit_max_instreams,
Vlad Yasevicha5a35e72007-03-23 11:34:08 -07001734 NULL, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001735 if (!ev)
1736 goto nomem_ev;
1737
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001738 /* Update the content of current association. */
1739 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1740 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001741 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
1742 return SCTP_DISPOSITION_CONSUME;
1743
1744nomem_ev:
1745 sctp_chunk_free(repl);
1746nomem:
1747 return SCTP_DISPOSITION_NOMEM;
1748}
1749
1750/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B')
1751 *
1752 * Section 5.2.4
1753 * B) In this case, both sides may be attempting to start an association
1754 * at about the same time but the peer endpoint started its INIT
1755 * after responding to the local endpoint's INIT
1756 */
1757/* This case represents an initialization collision. */
1758static sctp_disposition_t sctp_sf_do_dupcook_b(const struct sctp_endpoint *ep,
1759 const struct sctp_association *asoc,
1760 struct sctp_chunk *chunk,
1761 sctp_cmd_seq_t *commands,
1762 struct sctp_association *new_asoc)
1763{
1764 sctp_init_chunk_t *peer_init;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001765 struct sctp_chunk *repl;
1766
1767 /* new_asoc is a brand-new association, so these are not yet
1768 * side effects--it is safe to run them here.
1769 */
1770 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1771 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
1772 sctp_source(chunk), peer_init,
1773 GFP_ATOMIC))
1774 goto nomem;
1775
1776 /* Update the content of current association. */
1777 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1778 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1779 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1780 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
1781 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
1782
1783 repl = sctp_make_cookie_ack(new_asoc, chunk);
1784 if (!repl)
1785 goto nomem;
1786
1787 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1788 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
1789
1790 /* RFC 2960 5.1 Normal Establishment of an Association
1791 *
1792 * D) IMPLEMENTATION NOTE: An implementation may choose to
1793 * send the Communication Up notification to the SCTP user
1794 * upon reception of a valid COOKIE ECHO chunk.
Vlad Yasevich07d93962007-05-04 13:55:27 -07001795 *
1796 * Sadly, this needs to be implemented as a side-effect, because
1797 * we are not guaranteed to have set the association id of the real
1798 * association and so these notifications need to be delayed until
1799 * the association id is allocated.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001800 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001801
Vlad Yasevich07d93962007-05-04 13:55:27 -07001802 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_CHANGE, SCTP_U8(SCTP_COMM_UP));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001803
1804 /* Sockets API Draft Section 5.3.1.6
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -08001805 * When a peer sends a Adaptation Layer Indication parameter , SCTP
Linus Torvalds1da177e2005-04-16 15:20:36 -07001806 * delivers this notification to inform the application that of the
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -08001807 * peers requested adaptation layer.
Vlad Yasevich07d93962007-05-04 13:55:27 -07001808 *
1809 * This also needs to be done as a side effect for the same reason as
1810 * above.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001811 */
Vlad Yasevich07d93962007-05-04 13:55:27 -07001812 if (asoc->peer.adaptation_ind)
1813 sctp_add_cmd_sf(commands, SCTP_CMD_ADAPTATION_IND, SCTP_NULL());
Linus Torvalds1da177e2005-04-16 15:20:36 -07001814
1815 return SCTP_DISPOSITION_CONSUME;
1816
Linus Torvalds1da177e2005-04-16 15:20:36 -07001817nomem:
1818 return SCTP_DISPOSITION_NOMEM;
1819}
1820
1821/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C')
1822 *
1823 * Section 5.2.4
1824 * C) In this case, the local endpoint's cookie has arrived late.
1825 * Before it arrived, the local endpoint sent an INIT and received an
1826 * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag
1827 * but a new tag of its own.
1828 */
1829/* This case represents an initialization collision. */
1830static sctp_disposition_t sctp_sf_do_dupcook_c(const struct sctp_endpoint *ep,
1831 const struct sctp_association *asoc,
1832 struct sctp_chunk *chunk,
1833 sctp_cmd_seq_t *commands,
1834 struct sctp_association *new_asoc)
1835{
1836 /* The cookie should be silently discarded.
1837 * The endpoint SHOULD NOT change states and should leave
1838 * any timers running.
1839 */
1840 return SCTP_DISPOSITION_DISCARD;
1841}
1842
1843/* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D')
1844 *
1845 * Section 5.2.4
1846 *
1847 * D) When both local and remote tags match the endpoint should always
1848 * enter the ESTABLISHED state, if it has not already done so.
1849 */
1850/* This case represents an initialization collision. */
1851static sctp_disposition_t sctp_sf_do_dupcook_d(const struct sctp_endpoint *ep,
1852 const struct sctp_association *asoc,
1853 struct sctp_chunk *chunk,
1854 sctp_cmd_seq_t *commands,
1855 struct sctp_association *new_asoc)
1856{
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001857 struct sctp_ulpevent *ev = NULL, *ai_ev = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001858 struct sctp_chunk *repl;
1859
1860 /* Clarification from Implementor's Guide:
1861 * D) When both local and remote tags match the endpoint should
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001862 * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state.
1863 * It should stop any cookie timer that may be running and send
1864 * a COOKIE ACK.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001865 */
1866
1867 /* Don't accidentally move back into established state. */
1868 if (asoc->state < SCTP_STATE_ESTABLISHED) {
1869 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1870 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1871 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1872 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1873 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
1874 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START,
1875 SCTP_NULL());
1876
1877 /* RFC 2960 5.1 Normal Establishment of an Association
1878 *
1879 * D) IMPLEMENTATION NOTE: An implementation may choose
1880 * to send the Communication Up notification to the
1881 * SCTP user upon reception of a valid COOKIE
1882 * ECHO chunk.
1883 */
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001884 ev = sctp_ulpevent_make_assoc_change(asoc, 0,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001885 SCTP_COMM_UP, 0,
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001886 asoc->c.sinit_num_ostreams,
1887 asoc->c.sinit_max_instreams,
YOSHIFUJI Hideaki9cbcbf42007-07-19 10:44:50 +09001888 NULL, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001889 if (!ev)
1890 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001891
1892 /* Sockets API Draft Section 5.3.1.6
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -08001893 * When a peer sends a Adaptation Layer Indication parameter,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001894 * SCTP delivers this notification to inform the application
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -08001895 * that of the peers requested adaptation layer.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001896 */
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -08001897 if (asoc->peer.adaptation_ind) {
1898 ai_ev = sctp_ulpevent_make_adaptation_indication(asoc,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001899 GFP_ATOMIC);
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001900 if (!ai_ev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001901 goto nomem;
1902
Linus Torvalds1da177e2005-04-16 15:20:36 -07001903 }
1904 }
1905 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
1906
1907 repl = sctp_make_cookie_ack(new_asoc, chunk);
1908 if (!repl)
1909 goto nomem;
1910
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001911 if (ev)
1912 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1913 SCTP_ULPEVENT(ev));
1914 if (ai_ev)
1915 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1916 SCTP_ULPEVENT(ai_ev));
1917
Linus Torvalds1da177e2005-04-16 15:20:36 -07001918 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1919 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
1920
1921 return SCTP_DISPOSITION_CONSUME;
1922
1923nomem:
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001924 if (ai_ev)
1925 sctp_ulpevent_free(ai_ev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001926 if (ev)
1927 sctp_ulpevent_free(ev);
1928 return SCTP_DISPOSITION_NOMEM;
1929}
1930
1931/*
1932 * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying
1933 * chunk was retransmitted and then delayed in the network.
1934 *
1935 * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists
1936 *
1937 * Verification Tag: None. Do cookie validation.
1938 *
1939 * Inputs
1940 * (endpoint, asoc, chunk)
1941 *
1942 * Outputs
1943 * (asoc, reply_msg, msg_up, timers, counters)
1944 *
1945 * The return value is the disposition of the chunk.
1946 */
1947sctp_disposition_t sctp_sf_do_5_2_4_dupcook(const struct sctp_endpoint *ep,
1948 const struct sctp_association *asoc,
1949 const sctp_subtype_t type,
1950 void *arg,
1951 sctp_cmd_seq_t *commands)
1952{
1953 sctp_disposition_t retval;
1954 struct sctp_chunk *chunk = arg;
1955 struct sctp_association *new_asoc;
1956 int error = 0;
1957 char action;
1958 struct sctp_chunk *err_chk_p;
1959
1960 /* Make sure that the chunk has a valid length from the protocol
1961 * perspective. In this case check to make sure we have at least
1962 * enough for the chunk header. Cookie length verification is
1963 * done later.
1964 */
1965 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
1966 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1967 commands);
1968
1969 /* "Decode" the chunk. We have no optional parameters so we
1970 * are in good shape.
1971 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001972 chunk->subh.cookie_hdr = (struct sctp_signed_cookie *)chunk->skb->data;
Sridhar Samudrala62b08082006-05-05 17:04:43 -07001973 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
1974 sizeof(sctp_chunkhdr_t)))
1975 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001976
1977 /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
1978 * of a duplicate COOKIE ECHO match the Verification Tags of the
1979 * current association, consider the State Cookie valid even if
1980 * the lifespan is exceeded.
1981 */
1982 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
1983 &err_chk_p);
1984
1985 /* FIXME:
1986 * If the re-build failed, what is the proper error path
1987 * from here?
1988 *
1989 * [We should abort the association. --piggy]
1990 */
1991 if (!new_asoc) {
1992 /* FIXME: Several errors are possible. A bad cookie should
1993 * be silently discarded, but think about logging it too.
1994 */
1995 switch (error) {
1996 case -SCTP_IERROR_NOMEM:
1997 goto nomem;
1998
1999 case -SCTP_IERROR_STALE_COOKIE:
2000 sctp_send_stale_cookie_err(ep, asoc, chunk, commands,
2001 err_chk_p);
2002 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2003 case -SCTP_IERROR_BAD_SIG:
2004 default:
2005 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07002006 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002007 }
2008
2009 /* Compare the tie_tag in cookie with the verification tag of
2010 * current association.
2011 */
2012 action = sctp_tietags_compare(new_asoc, asoc);
2013
2014 switch (action) {
2015 case 'A': /* Association restart. */
2016 retval = sctp_sf_do_dupcook_a(ep, asoc, chunk, commands,
2017 new_asoc);
2018 break;
2019
2020 case 'B': /* Collision case B. */
2021 retval = sctp_sf_do_dupcook_b(ep, asoc, chunk, commands,
2022 new_asoc);
2023 break;
2024
2025 case 'C': /* Collision case C. */
2026 retval = sctp_sf_do_dupcook_c(ep, asoc, chunk, commands,
2027 new_asoc);
2028 break;
2029
2030 case 'D': /* Collision case D. */
2031 retval = sctp_sf_do_dupcook_d(ep, asoc, chunk, commands,
2032 new_asoc);
2033 break;
2034
2035 default: /* Discard packet for all others. */
2036 retval = sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2037 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07002038 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002039
2040 /* Delete the tempory new association. */
2041 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
2042 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
2043
2044 return retval;
2045
2046nomem:
2047 return SCTP_DISPOSITION_NOMEM;
2048}
2049
2050/*
2051 * Process an ABORT. (SHUTDOWN-PENDING state)
2052 *
2053 * See sctp_sf_do_9_1_abort().
2054 */
2055sctp_disposition_t sctp_sf_shutdown_pending_abort(
2056 const struct sctp_endpoint *ep,
2057 const struct sctp_association *asoc,
2058 const sctp_subtype_t type,
2059 void *arg,
2060 sctp_cmd_seq_t *commands)
2061{
2062 struct sctp_chunk *chunk = arg;
2063
2064 if (!sctp_vtag_verify_either(chunk, asoc))
2065 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2066
2067 /* Make sure that the ABORT chunk has a valid length.
2068 * Since this is an ABORT chunk, we have to discard it
2069 * because of the following text:
2070 * RFC 2960, Section 3.3.7
2071 * If an endpoint receives an ABORT with a format error or for an
2072 * association that doesn't exist, it MUST silently discard it.
2073 * Becasue the length is "invalid", we can't really discard just
2074 * as we do not know its true length. So, to be safe, discard the
2075 * packet.
2076 */
2077 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2078 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2079
Vlad Yasevich75205f42007-12-20 14:12:59 -08002080 /* ADD-IP: Special case for ABORT chunks
2081 * F4) One special consideration is that ABORT Chunks arriving
2082 * destined to the IP address being deleted MUST be
2083 * ignored (see Section 5.3.1 for further details).
2084 */
2085 if (SCTP_ADDR_DEL ==
2086 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2087 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
2088
Linus Torvalds1da177e2005-04-16 15:20:36 -07002089 /* Stop the T5-shutdown guard timer. */
2090 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2091 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
2092
Vlad Yasevich75205f42007-12-20 14:12:59 -08002093 return __sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002094}
2095
2096/*
2097 * Process an ABORT. (SHUTDOWN-SENT state)
2098 *
2099 * See sctp_sf_do_9_1_abort().
2100 */
2101sctp_disposition_t sctp_sf_shutdown_sent_abort(const struct sctp_endpoint *ep,
2102 const struct sctp_association *asoc,
2103 const sctp_subtype_t type,
2104 void *arg,
2105 sctp_cmd_seq_t *commands)
2106{
2107 struct sctp_chunk *chunk = arg;
2108
2109 if (!sctp_vtag_verify_either(chunk, asoc))
2110 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2111
2112 /* Make sure that the ABORT chunk has a valid length.
2113 * Since this is an ABORT chunk, we have to discard it
2114 * because of the following text:
2115 * RFC 2960, Section 3.3.7
2116 * If an endpoint receives an ABORT with a format error or for an
2117 * association that doesn't exist, it MUST silently discard it.
2118 * Becasue the length is "invalid", we can't really discard just
2119 * as we do not know its true length. So, to be safe, discard the
2120 * packet.
2121 */
2122 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2123 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2124
Vlad Yasevich75205f42007-12-20 14:12:59 -08002125 /* ADD-IP: Special case for ABORT chunks
2126 * F4) One special consideration is that ABORT Chunks arriving
2127 * destined to the IP address being deleted MUST be
2128 * ignored (see Section 5.3.1 for further details).
2129 */
2130 if (SCTP_ADDR_DEL ==
2131 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2132 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
2133
Linus Torvalds1da177e2005-04-16 15:20:36 -07002134 /* Stop the T2-shutdown timer. */
2135 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2136 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2137
2138 /* Stop the T5-shutdown guard timer. */
2139 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2140 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
2141
Vlad Yasevich75205f42007-12-20 14:12:59 -08002142 return __sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002143}
2144
2145/*
2146 * Process an ABORT. (SHUTDOWN-ACK-SENT state)
2147 *
2148 * See sctp_sf_do_9_1_abort().
2149 */
2150sctp_disposition_t sctp_sf_shutdown_ack_sent_abort(
2151 const struct sctp_endpoint *ep,
2152 const struct sctp_association *asoc,
2153 const sctp_subtype_t type,
2154 void *arg,
2155 sctp_cmd_seq_t *commands)
2156{
2157 /* The same T2 timer, so we should be able to use
2158 * common function with the SHUTDOWN-SENT state.
2159 */
2160 return sctp_sf_shutdown_sent_abort(ep, asoc, type, arg, commands);
2161}
2162
2163/*
2164 * Handle an Error received in COOKIE_ECHOED state.
2165 *
2166 * Only handle the error type of stale COOKIE Error, the other errors will
2167 * be ignored.
2168 *
2169 * Inputs
2170 * (endpoint, asoc, chunk)
2171 *
2172 * Outputs
2173 * (asoc, reply_msg, msg_up, timers, counters)
2174 *
2175 * The return value is the disposition of the chunk.
2176 */
2177sctp_disposition_t sctp_sf_cookie_echoed_err(const struct sctp_endpoint *ep,
2178 const struct sctp_association *asoc,
2179 const sctp_subtype_t type,
2180 void *arg,
2181 sctp_cmd_seq_t *commands)
2182{
2183 struct sctp_chunk *chunk = arg;
2184 sctp_errhdr_t *err;
2185
2186 if (!sctp_vtag_verify(chunk, asoc))
2187 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2188
2189 /* Make sure that the ERROR chunk has a valid length.
2190 * The parameter walking depends on this as well.
2191 */
2192 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
2193 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2194 commands);
2195
2196 /* Process the error here */
2197 /* FUTURE FIXME: When PR-SCTP related and other optional
2198 * parms are emitted, this will have to change to handle multiple
2199 * errors.
2200 */
2201 sctp_walk_errors(err, chunk->chunk_hdr) {
2202 if (SCTP_ERROR_STALE_COOKIE == err->cause)
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002203 return sctp_sf_do_5_2_6_stale(ep, asoc, type,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002204 arg, commands);
2205 }
2206
2207 /* It is possible to have malformed error causes, and that
2208 * will cause us to end the walk early. However, since
2209 * we are discarding the packet, there should be no adverse
2210 * affects.
2211 */
2212 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2213}
2214
2215/*
2216 * Handle a Stale COOKIE Error
2217 *
2218 * Section: 5.2.6 Handle Stale COOKIE Error
2219 * If the association is in the COOKIE-ECHOED state, the endpoint may elect
2220 * one of the following three alternatives.
2221 * ...
2222 * 3) Send a new INIT chunk to the endpoint, adding a Cookie
2223 * Preservative parameter requesting an extension to the lifetime of
2224 * the State Cookie. When calculating the time extension, an
2225 * implementation SHOULD use the RTT information measured based on the
2226 * previous COOKIE ECHO / ERROR exchange, and should add no more
2227 * than 1 second beyond the measured RTT, due to long State Cookie
2228 * lifetimes making the endpoint more subject to a replay attack.
2229 *
2230 * Verification Tag: Not explicit, but safe to ignore.
2231 *
2232 * Inputs
2233 * (endpoint, asoc, chunk)
2234 *
2235 * Outputs
2236 * (asoc, reply_msg, msg_up, timers, counters)
2237 *
2238 * The return value is the disposition of the chunk.
2239 */
2240static sctp_disposition_t sctp_sf_do_5_2_6_stale(const struct sctp_endpoint *ep,
2241 const struct sctp_association *asoc,
2242 const sctp_subtype_t type,
2243 void *arg,
2244 sctp_cmd_seq_t *commands)
2245{
2246 struct sctp_chunk *chunk = arg;
2247 time_t stale;
2248 sctp_cookie_preserve_param_t bht;
2249 sctp_errhdr_t *err;
2250 struct sctp_chunk *reply;
2251 struct sctp_bind_addr *bp;
Frank Filz3f7a87d2005-06-20 13:14:57 -07002252 int attempts = asoc->init_err_counter + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002253
Vlad Yasevich81845c22006-01-30 15:59:54 -08002254 if (attempts > asoc->max_init_attempts) {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002255 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
2256 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002257 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08002258 SCTP_PERR(SCTP_ERROR_STALE_COOKIE));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002259 return SCTP_DISPOSITION_DELETE_TCB;
2260 }
2261
2262 err = (sctp_errhdr_t *)(chunk->skb->data);
2263
2264 /* When calculating the time extension, an implementation
2265 * SHOULD use the RTT information measured based on the
2266 * previous COOKIE ECHO / ERROR exchange, and should add no
2267 * more than 1 second beyond the measured RTT, due to long
2268 * State Cookie lifetimes making the endpoint more subject to
2269 * a replay attack.
2270 * Measure of Staleness's unit is usec. (1/1000000 sec)
2271 * Suggested Cookie Life-span Increment's unit is msec.
2272 * (1/1000 sec)
2273 * In general, if you use the suggested cookie life, the value
2274 * found in the field of measure of staleness should be doubled
2275 * to give ample time to retransmit the new cookie and thus
2276 * yield a higher probability of success on the reattempt.
2277 */
Al Viro34bcca22006-11-20 17:27:15 -08002278 stale = ntohl(*(__be32 *)((u8 *)err + sizeof(sctp_errhdr_t)));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002279 stale = (stale * 2) / 1000;
2280
2281 bht.param_hdr.type = SCTP_PARAM_COOKIE_PRESERVATIVE;
2282 bht.param_hdr.length = htons(sizeof(bht));
2283 bht.lifespan_increment = htonl(stale);
2284
2285 /* Build that new INIT chunk. */
2286 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
2287 reply = sctp_make_init(asoc, bp, GFP_ATOMIC, sizeof(bht));
2288 if (!reply)
2289 goto nomem;
2290
2291 sctp_addto_chunk(reply, sizeof(bht), &bht);
2292
2293 /* Clear peer's init_tag cached in assoc as we are sending a new INIT */
2294 sctp_add_cmd_sf(commands, SCTP_CMD_CLEAR_INIT_TAG, SCTP_NULL());
2295
2296 /* Stop pending T3-rtx and heartbeat timers */
2297 sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
2298 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
2299
2300 /* Delete non-primary peer ip addresses since we are transitioning
2301 * back to the COOKIE-WAIT state
2302 */
2303 sctp_add_cmd_sf(commands, SCTP_CMD_DEL_NON_PRIMARY, SCTP_NULL());
2304
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002305 /* If we've sent any data bundled with COOKIE-ECHO we will need to
2306 * resend
Linus Torvalds1da177e2005-04-16 15:20:36 -07002307 */
Vlad Yasevichb6157d82007-10-24 15:59:16 -04002308 sctp_add_cmd_sf(commands, SCTP_CMD_T1_RETRAN,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002309 SCTP_TRANSPORT(asoc->peer.primary_path));
2310
2311 /* Cast away the const modifier, as we want to just
2312 * rerun it through as a sideffect.
2313 */
Frank Filz3f7a87d2005-06-20 13:14:57 -07002314 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_INC, SCTP_NULL());
Linus Torvalds1da177e2005-04-16 15:20:36 -07002315
2316 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2317 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
2318 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2319 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
2320 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
2321 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
2322
2323 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2324
2325 return SCTP_DISPOSITION_CONSUME;
2326
2327nomem:
2328 return SCTP_DISPOSITION_NOMEM;
2329}
2330
2331/*
2332 * Process an ABORT.
2333 *
2334 * Section: 9.1
2335 * After checking the Verification Tag, the receiving endpoint shall
2336 * remove the association from its record, and shall report the
2337 * termination to its upper layer.
2338 *
2339 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
2340 * B) Rules for packet carrying ABORT:
2341 *
2342 * - The endpoint shall always fill in the Verification Tag field of the
2343 * outbound packet with the destination endpoint's tag value if it
2344 * is known.
2345 *
2346 * - If the ABORT is sent in response to an OOTB packet, the endpoint
2347 * MUST follow the procedure described in Section 8.4.
2348 *
2349 * - The receiver MUST accept the packet if the Verification Tag
2350 * matches either its own tag, OR the tag of its peer. Otherwise, the
2351 * receiver MUST silently discard the packet and take no further
2352 * action.
2353 *
2354 * Inputs
2355 * (endpoint, asoc, chunk)
2356 *
2357 * Outputs
2358 * (asoc, reply_msg, msg_up, timers, counters)
2359 *
2360 * The return value is the disposition of the chunk.
2361 */
2362sctp_disposition_t sctp_sf_do_9_1_abort(const struct sctp_endpoint *ep,
2363 const struct sctp_association *asoc,
2364 const sctp_subtype_t type,
2365 void *arg,
2366 sctp_cmd_seq_t *commands)
2367{
2368 struct sctp_chunk *chunk = arg;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002369
2370 if (!sctp_vtag_verify_either(chunk, asoc))
2371 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2372
2373 /* Make sure that the ABORT chunk has a valid length.
2374 * Since this is an ABORT chunk, we have to discard it
2375 * because of the following text:
2376 * RFC 2960, Section 3.3.7
2377 * If an endpoint receives an ABORT with a format error or for an
2378 * association that doesn't exist, it MUST silently discard it.
2379 * Becasue the length is "invalid", we can't really discard just
2380 * as we do not know its true length. So, to be safe, discard the
2381 * packet.
2382 */
2383 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2384 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2385
Vlad Yasevich75205f42007-12-20 14:12:59 -08002386 /* ADD-IP: Special case for ABORT chunks
2387 * F4) One special consideration is that ABORT Chunks arriving
2388 * destined to the IP address being deleted MUST be
2389 * ignored (see Section 5.3.1 for further details).
2390 */
2391 if (SCTP_ADDR_DEL ==
2392 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2393 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
2394
2395 return __sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
2396}
2397
2398static sctp_disposition_t __sctp_sf_do_9_1_abort(const struct sctp_endpoint *ep,
2399 const struct sctp_association *asoc,
2400 const sctp_subtype_t type,
2401 void *arg,
2402 sctp_cmd_seq_t *commands)
2403{
2404 struct sctp_chunk *chunk = arg;
2405 unsigned len;
2406 __be16 error = SCTP_ERROR_NO_ERROR;
2407
Linus Torvalds1da177e2005-04-16 15:20:36 -07002408 /* See if we have an error cause code in the chunk. */
2409 len = ntohs(chunk->chunk_hdr->length);
2410 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
2411 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2412
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002413 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNRESET));
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002414 /* ASSOC_FAILED will DELETE_TCB. */
Al Viro5be291f2006-11-20 17:01:06 -08002415 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, SCTP_PERR(error));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002416 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
2417 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
2418
2419 return SCTP_DISPOSITION_ABORT;
2420}
2421
2422/*
2423 * Process an ABORT. (COOKIE-WAIT state)
2424 *
2425 * See sctp_sf_do_9_1_abort() above.
2426 */
2427sctp_disposition_t sctp_sf_cookie_wait_abort(const struct sctp_endpoint *ep,
2428 const struct sctp_association *asoc,
2429 const sctp_subtype_t type,
2430 void *arg,
2431 sctp_cmd_seq_t *commands)
2432{
2433 struct sctp_chunk *chunk = arg;
2434 unsigned len;
Al Virof94c0192006-11-20 17:00:25 -08002435 __be16 error = SCTP_ERROR_NO_ERROR;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002436
2437 if (!sctp_vtag_verify_either(chunk, asoc))
2438 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2439
2440 /* Make sure that the ABORT chunk has a valid length.
2441 * Since this is an ABORT chunk, we have to discard it
2442 * because of the following text:
2443 * RFC 2960, Section 3.3.7
2444 * If an endpoint receives an ABORT with a format error or for an
2445 * association that doesn't exist, it MUST silently discard it.
2446 * Becasue the length is "invalid", we can't really discard just
2447 * as we do not know its true length. So, to be safe, discard the
2448 * packet.
2449 */
2450 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2451 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2452
2453 /* See if we have an error cause code in the chunk. */
2454 len = ntohs(chunk->chunk_hdr->length);
2455 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
2456 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2457
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002458 return sctp_stop_t1_and_abort(commands, error, ECONNREFUSED, asoc,
2459 chunk->transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002460}
2461
2462/*
2463 * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state)
2464 */
2465sctp_disposition_t sctp_sf_cookie_wait_icmp_abort(const struct sctp_endpoint *ep,
2466 const struct sctp_association *asoc,
2467 const sctp_subtype_t type,
2468 void *arg,
2469 sctp_cmd_seq_t *commands)
2470{
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002471 return sctp_stop_t1_and_abort(commands, SCTP_ERROR_NO_ERROR,
2472 ENOPROTOOPT, asoc,
Frank Filz3f7a87d2005-06-20 13:14:57 -07002473 (struct sctp_transport *)arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002474}
2475
2476/*
2477 * Process an ABORT. (COOKIE-ECHOED state)
2478 */
2479sctp_disposition_t sctp_sf_cookie_echoed_abort(const struct sctp_endpoint *ep,
2480 const struct sctp_association *asoc,
2481 const sctp_subtype_t type,
2482 void *arg,
2483 sctp_cmd_seq_t *commands)
2484{
2485 /* There is a single T1 timer, so we should be able to use
2486 * common function with the COOKIE-WAIT state.
2487 */
2488 return sctp_sf_cookie_wait_abort(ep, asoc, type, arg, commands);
2489}
2490
2491/*
2492 * Stop T1 timer and abort association with "INIT failed".
2493 *
2494 * This is common code called by several sctp_sf_*_abort() functions above.
2495 */
Adrian Bunk52c1da32005-06-23 22:05:33 -07002496static sctp_disposition_t sctp_stop_t1_and_abort(sctp_cmd_seq_t *commands,
Al Virof94c0192006-11-20 17:00:25 -08002497 __be16 error, int sk_err,
Frank Filz3f7a87d2005-06-20 13:14:57 -07002498 const struct sctp_association *asoc,
2499 struct sctp_transport *transport)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002500{
Frank Filz3f7a87d2005-06-20 13:14:57 -07002501 SCTP_DEBUG_PRINTK("ABORT received (INIT).\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07002502 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2503 SCTP_STATE(SCTP_STATE_CLOSED));
2504 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
2505 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2506 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002507 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(sk_err));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002508 /* CMD_INIT_FAILED will DELETE_TCB. */
2509 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08002510 SCTP_PERR(error));
Frank Filz3f7a87d2005-06-20 13:14:57 -07002511 return SCTP_DISPOSITION_ABORT;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002512}
2513
2514/*
2515 * sctp_sf_do_9_2_shut
2516 *
2517 * Section: 9.2
2518 * Upon the reception of the SHUTDOWN, the peer endpoint shall
2519 * - enter the SHUTDOWN-RECEIVED state,
2520 *
2521 * - stop accepting new data from its SCTP user
2522 *
2523 * - verify, by checking the Cumulative TSN Ack field of the chunk,
2524 * that all its outstanding DATA chunks have been received by the
2525 * SHUTDOWN sender.
2526 *
2527 * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT
2528 * send a SHUTDOWN in response to a ULP request. And should discard
2529 * subsequent SHUTDOWN chunks.
2530 *
2531 * If there are still outstanding DATA chunks left, the SHUTDOWN
2532 * receiver shall continue to follow normal data transmission
2533 * procedures defined in Section 6 until all outstanding DATA chunks
2534 * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept
2535 * new data from its SCTP user.
2536 *
2537 * Verification Tag: 8.5 Verification Tag [Normal verification]
2538 *
2539 * Inputs
2540 * (endpoint, asoc, chunk)
2541 *
2542 * Outputs
2543 * (asoc, reply_msg, msg_up, timers, counters)
2544 *
2545 * The return value is the disposition of the chunk.
2546 */
2547sctp_disposition_t sctp_sf_do_9_2_shutdown(const struct sctp_endpoint *ep,
2548 const struct sctp_association *asoc,
2549 const sctp_subtype_t type,
2550 void *arg,
2551 sctp_cmd_seq_t *commands)
2552{
2553 struct sctp_chunk *chunk = arg;
2554 sctp_shutdownhdr_t *sdh;
2555 sctp_disposition_t disposition;
2556 struct sctp_ulpevent *ev;
2557
2558 if (!sctp_vtag_verify(chunk, asoc))
2559 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2560
2561 /* Make sure that the SHUTDOWN chunk has a valid length. */
2562 if (!sctp_chunk_length_valid(chunk,
2563 sizeof(struct sctp_shutdown_chunk_t)))
2564 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2565 commands);
2566
2567 /* Convert the elaborate header. */
2568 sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
2569 skb_pull(chunk->skb, sizeof(sctp_shutdownhdr_t));
2570 chunk->subh.shutdown_hdr = sdh;
2571
Sridhar Samudralaeb0e0072005-09-22 23:48:38 -07002572 /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT
2573 * When a peer sends a SHUTDOWN, SCTP delivers this notification to
2574 * inform the application that it should cease sending data.
2575 */
2576 ev = sctp_ulpevent_make_shutdown_event(asoc, 0, GFP_ATOMIC);
2577 if (!ev) {
2578 disposition = SCTP_DISPOSITION_NOMEM;
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002579 goto out;
Sridhar Samudralaeb0e0072005-09-22 23:48:38 -07002580 }
2581 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
2582
Linus Torvalds1da177e2005-04-16 15:20:36 -07002583 /* Upon the reception of the SHUTDOWN, the peer endpoint shall
2584 * - enter the SHUTDOWN-RECEIVED state,
2585 * - stop accepting new data from its SCTP user
2586 *
2587 * [This is implicit in the new state.]
2588 */
2589 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2590 SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED));
2591 disposition = SCTP_DISPOSITION_CONSUME;
2592
2593 if (sctp_outq_is_empty(&asoc->outqueue)) {
2594 disposition = sctp_sf_do_9_2_shutdown_ack(ep, asoc, type,
2595 arg, commands);
2596 }
2597
2598 if (SCTP_DISPOSITION_NOMEM == disposition)
2599 goto out;
2600
2601 /* - verify, by checking the Cumulative TSN Ack field of the
2602 * chunk, that all its outstanding DATA chunks have been
2603 * received by the SHUTDOWN sender.
2604 */
2605 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
Al Viro2178eda2006-11-20 17:26:53 -08002606 SCTP_BE32(chunk->subh.shutdown_hdr->cum_tsn_ack));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002607
Linus Torvalds1da177e2005-04-16 15:20:36 -07002608out:
2609 return disposition;
2610}
2611
2612/* RFC 2960 9.2
2613 * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk
2614 * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination
2615 * transport addresses (either in the IP addresses or in the INIT chunk)
2616 * that belong to this association, it should discard the INIT chunk and
2617 * retransmit the SHUTDOWN ACK chunk.
2618 */
2619sctp_disposition_t sctp_sf_do_9_2_reshutack(const struct sctp_endpoint *ep,
2620 const struct sctp_association *asoc,
2621 const sctp_subtype_t type,
2622 void *arg,
2623 sctp_cmd_seq_t *commands)
2624{
2625 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
2626 struct sctp_chunk *reply;
2627
Vlad Yasevichece25df2007-09-07 16:30:54 -04002628 /* Make sure that the chunk has a valid length */
2629 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
2630 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2631 commands);
2632
Linus Torvalds1da177e2005-04-16 15:20:36 -07002633 /* Since we are not going to really process this INIT, there
2634 * is no point in verifying chunk boundries. Just generate
2635 * the SHUTDOWN ACK.
2636 */
2637 reply = sctp_make_shutdown_ack(asoc, chunk);
2638 if (NULL == reply)
2639 goto nomem;
2640
2641 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
2642 * the T2-SHUTDOWN timer.
2643 */
2644 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
2645
2646 /* and restart the T2-shutdown timer. */
2647 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2648 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2649
2650 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2651
2652 return SCTP_DISPOSITION_CONSUME;
2653nomem:
2654 return SCTP_DISPOSITION_NOMEM;
2655}
2656
2657/*
2658 * sctp_sf_do_ecn_cwr
2659 *
2660 * Section: Appendix A: Explicit Congestion Notification
2661 *
2662 * CWR:
2663 *
2664 * RFC 2481 details a specific bit for a sender to send in the header of
2665 * its next outbound TCP segment to indicate to its peer that it has
2666 * reduced its congestion window. This is termed the CWR bit. For
2667 * SCTP the same indication is made by including the CWR chunk.
2668 * This chunk contains one data element, i.e. the TSN number that
2669 * was sent in the ECNE chunk. This element represents the lowest
2670 * TSN number in the datagram that was originally marked with the
2671 * CE bit.
2672 *
2673 * Verification Tag: 8.5 Verification Tag [Normal verification]
2674 * Inputs
2675 * (endpoint, asoc, chunk)
2676 *
2677 * Outputs
2678 * (asoc, reply_msg, msg_up, timers, counters)
2679 *
2680 * The return value is the disposition of the chunk.
2681 */
2682sctp_disposition_t sctp_sf_do_ecn_cwr(const struct sctp_endpoint *ep,
2683 const struct sctp_association *asoc,
2684 const sctp_subtype_t type,
2685 void *arg,
2686 sctp_cmd_seq_t *commands)
2687{
2688 sctp_cwrhdr_t *cwr;
2689 struct sctp_chunk *chunk = arg;
Al Viro34bcca22006-11-20 17:27:15 -08002690 u32 lowest_tsn;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002691
2692 if (!sctp_vtag_verify(chunk, asoc))
2693 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2694
2695 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2696 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2697 commands);
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002698
Linus Torvalds1da177e2005-04-16 15:20:36 -07002699 cwr = (sctp_cwrhdr_t *) chunk->skb->data;
2700 skb_pull(chunk->skb, sizeof(sctp_cwrhdr_t));
2701
Al Viro34bcca22006-11-20 17:27:15 -08002702 lowest_tsn = ntohl(cwr->lowest_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002703
2704 /* Does this CWR ack the last sent congestion notification? */
Al Viro34bcca22006-11-20 17:27:15 -08002705 if (TSN_lte(asoc->last_ecne_tsn, lowest_tsn)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002706 /* Stop sending ECNE. */
2707 sctp_add_cmd_sf(commands,
2708 SCTP_CMD_ECN_CWR,
Al Viro34bcca22006-11-20 17:27:15 -08002709 SCTP_U32(lowest_tsn));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002710 }
2711 return SCTP_DISPOSITION_CONSUME;
2712}
2713
2714/*
2715 * sctp_sf_do_ecne
2716 *
2717 * Section: Appendix A: Explicit Congestion Notification
2718 *
2719 * ECN-Echo
2720 *
2721 * RFC 2481 details a specific bit for a receiver to send back in its
2722 * TCP acknowledgements to notify the sender of the Congestion
2723 * Experienced (CE) bit having arrived from the network. For SCTP this
2724 * same indication is made by including the ECNE chunk. This chunk
2725 * contains one data element, i.e. the lowest TSN associated with the IP
2726 * datagram marked with the CE bit.....
2727 *
2728 * Verification Tag: 8.5 Verification Tag [Normal verification]
2729 * Inputs
2730 * (endpoint, asoc, chunk)
2731 *
2732 * Outputs
2733 * (asoc, reply_msg, msg_up, timers, counters)
2734 *
2735 * The return value is the disposition of the chunk.
2736 */
2737sctp_disposition_t sctp_sf_do_ecne(const struct sctp_endpoint *ep,
2738 const struct sctp_association *asoc,
2739 const sctp_subtype_t type,
2740 void *arg,
2741 sctp_cmd_seq_t *commands)
2742{
2743 sctp_ecnehdr_t *ecne;
2744 struct sctp_chunk *chunk = arg;
2745
2746 if (!sctp_vtag_verify(chunk, asoc))
2747 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2748
2749 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2750 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2751 commands);
2752
2753 ecne = (sctp_ecnehdr_t *) chunk->skb->data;
2754 skb_pull(chunk->skb, sizeof(sctp_ecnehdr_t));
2755
2756 /* If this is a newer ECNE than the last CWR packet we sent out */
2757 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_ECNE,
2758 SCTP_U32(ntohl(ecne->lowest_tsn)));
2759
2760 return SCTP_DISPOSITION_CONSUME;
2761}
2762
2763/*
2764 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
2765 *
2766 * The SCTP endpoint MUST always acknowledge the reception of each valid
2767 * DATA chunk.
2768 *
2769 * The guidelines on delayed acknowledgement algorithm specified in
2770 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
2771 * acknowledgement SHOULD be generated for at least every second packet
2772 * (not every second DATA chunk) received, and SHOULD be generated within
2773 * 200 ms of the arrival of any unacknowledged DATA chunk. In some
2774 * situations it may be beneficial for an SCTP transmitter to be more
2775 * conservative than the algorithms detailed in this document allow.
2776 * However, an SCTP transmitter MUST NOT be more aggressive than the
2777 * following algorithms allow.
2778 *
2779 * A SCTP receiver MUST NOT generate more than one SACK for every
2780 * incoming packet, other than to update the offered window as the
2781 * receiving application consumes new data.
2782 *
2783 * Verification Tag: 8.5 Verification Tag [Normal verification]
2784 *
2785 * Inputs
2786 * (endpoint, asoc, chunk)
2787 *
2788 * Outputs
2789 * (asoc, reply_msg, msg_up, timers, counters)
2790 *
2791 * The return value is the disposition of the chunk.
2792 */
2793sctp_disposition_t sctp_sf_eat_data_6_2(const struct sctp_endpoint *ep,
2794 const struct sctp_association *asoc,
2795 const sctp_subtype_t type,
2796 void *arg,
2797 sctp_cmd_seq_t *commands)
2798{
2799 struct sctp_chunk *chunk = arg;
2800 int error;
2801
2802 if (!sctp_vtag_verify(chunk, asoc)) {
2803 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
2804 SCTP_NULL());
2805 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002806 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002807
2808 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
2809 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2810 commands);
2811
2812 error = sctp_eat_data(asoc, chunk, commands );
2813 switch (error) {
2814 case SCTP_IERROR_NO_ERROR:
2815 break;
2816 case SCTP_IERROR_HIGH_TSN:
2817 case SCTP_IERROR_BAD_STREAM:
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07002818 SCTP_INC_STATS(SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002819 goto discard_noforce;
2820 case SCTP_IERROR_DUP_TSN:
2821 case SCTP_IERROR_IGNORE_TSN:
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07002822 SCTP_INC_STATS(SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002823 goto discard_force;
2824 case SCTP_IERROR_NO_DATA:
2825 goto consume;
2826 default:
2827 BUG();
2828 }
2829
2830 if (asoc->autoclose) {
2831 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2832 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
2833 }
2834
2835 /* If this is the last chunk in a packet, we need to count it
2836 * toward sack generation. Note that we need to SACK every
2837 * OTHER packet containing data chunks, EVEN IF WE DISCARD
2838 * THEM. We elect to NOT generate SACK's if the chunk fails
2839 * the verification tag test.
2840 *
2841 * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2842 *
2843 * The SCTP endpoint MUST always acknowledge the reception of
2844 * each valid DATA chunk.
2845 *
2846 * The guidelines on delayed acknowledgement algorithm
2847 * specified in Section 4.2 of [RFC2581] SHOULD be followed.
2848 * Specifically, an acknowledgement SHOULD be generated for at
2849 * least every second packet (not every second DATA chunk)
2850 * received, and SHOULD be generated within 200 ms of the
2851 * arrival of any unacknowledged DATA chunk. In some
2852 * situations it may be beneficial for an SCTP transmitter to
2853 * be more conservative than the algorithms detailed in this
2854 * document allow. However, an SCTP transmitter MUST NOT be
2855 * more aggressive than the following algorithms allow.
2856 */
Frank Filz52ccb8e2005-12-22 11:36:46 -08002857 if (chunk->end_of_packet)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002858 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
2859
Linus Torvalds1da177e2005-04-16 15:20:36 -07002860 return SCTP_DISPOSITION_CONSUME;
2861
2862discard_force:
2863 /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2864 *
2865 * When a packet arrives with duplicate DATA chunk(s) and with
2866 * no new DATA chunk(s), the endpoint MUST immediately send a
2867 * SACK with no delay. If a packet arrives with duplicate
2868 * DATA chunk(s) bundled with new DATA chunks, the endpoint
2869 * MAY immediately send a SACK. Normally receipt of duplicate
2870 * DATA chunks will occur when the original SACK chunk was lost
2871 * and the peer's RTO has expired. The duplicate TSN number(s)
2872 * SHOULD be reported in the SACK as duplicate.
2873 */
2874 /* In our case, we split the MAY SACK advice up whether or not
2875 * the last chunk is a duplicate.'
2876 */
2877 if (chunk->end_of_packet)
2878 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
2879 return SCTP_DISPOSITION_DISCARD;
2880
2881discard_noforce:
Frank Filz52ccb8e2005-12-22 11:36:46 -08002882 if (chunk->end_of_packet)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002883 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
2884
Linus Torvalds1da177e2005-04-16 15:20:36 -07002885 return SCTP_DISPOSITION_DISCARD;
2886consume:
2887 return SCTP_DISPOSITION_CONSUME;
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002888
Linus Torvalds1da177e2005-04-16 15:20:36 -07002889}
2890
2891/*
2892 * sctp_sf_eat_data_fast_4_4
2893 *
2894 * Section: 4 (4)
2895 * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received
2896 * DATA chunks without delay.
2897 *
2898 * Verification Tag: 8.5 Verification Tag [Normal verification]
2899 * Inputs
2900 * (endpoint, asoc, chunk)
2901 *
2902 * Outputs
2903 * (asoc, reply_msg, msg_up, timers, counters)
2904 *
2905 * The return value is the disposition of the chunk.
2906 */
2907sctp_disposition_t sctp_sf_eat_data_fast_4_4(const struct sctp_endpoint *ep,
2908 const struct sctp_association *asoc,
2909 const sctp_subtype_t type,
2910 void *arg,
2911 sctp_cmd_seq_t *commands)
2912{
2913 struct sctp_chunk *chunk = arg;
2914 int error;
2915
2916 if (!sctp_vtag_verify(chunk, asoc)) {
2917 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
2918 SCTP_NULL());
2919 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2920 }
2921
2922 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
2923 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2924 commands);
2925
2926 error = sctp_eat_data(asoc, chunk, commands );
2927 switch (error) {
2928 case SCTP_IERROR_NO_ERROR:
2929 case SCTP_IERROR_HIGH_TSN:
2930 case SCTP_IERROR_DUP_TSN:
2931 case SCTP_IERROR_IGNORE_TSN:
2932 case SCTP_IERROR_BAD_STREAM:
2933 break;
2934 case SCTP_IERROR_NO_DATA:
2935 goto consume;
2936 default:
2937 BUG();
2938 }
2939
2940 /* Go a head and force a SACK, since we are shutting down. */
2941
2942 /* Implementor's Guide.
2943 *
2944 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
2945 * respond to each received packet containing one or more DATA chunk(s)
2946 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
2947 */
2948 if (chunk->end_of_packet) {
2949 /* We must delay the chunk creation since the cumulative
2950 * TSN has not been updated yet.
2951 */
2952 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
2953 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
2954 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2955 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2956 }
2957
2958consume:
2959 return SCTP_DISPOSITION_CONSUME;
2960}
2961
2962/*
2963 * Section: 6.2 Processing a Received SACK
2964 * D) Any time a SACK arrives, the endpoint performs the following:
2965 *
2966 * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point,
2967 * then drop the SACK. Since Cumulative TSN Ack is monotonically
2968 * increasing, a SACK whose Cumulative TSN Ack is less than the
2969 * Cumulative TSN Ack Point indicates an out-of-order SACK.
2970 *
2971 * ii) Set rwnd equal to the newly received a_rwnd minus the number
2972 * of bytes still outstanding after processing the Cumulative TSN Ack
2973 * and the Gap Ack Blocks.
2974 *
2975 * iii) If the SACK is missing a TSN that was previously
2976 * acknowledged via a Gap Ack Block (e.g., the data receiver
2977 * reneged on the data), then mark the corresponding DATA chunk
2978 * as available for retransmit: Mark it as missing for fast
2979 * retransmit as described in Section 7.2.4 and if no retransmit
2980 * timer is running for the destination address to which the DATA
2981 * chunk was originally transmitted, then T3-rtx is started for
2982 * that destination address.
2983 *
2984 * Verification Tag: 8.5 Verification Tag [Normal verification]
2985 *
2986 * Inputs
2987 * (endpoint, asoc, chunk)
2988 *
2989 * Outputs
2990 * (asoc, reply_msg, msg_up, timers, counters)
2991 *
2992 * The return value is the disposition of the chunk.
2993 */
2994sctp_disposition_t sctp_sf_eat_sack_6_2(const struct sctp_endpoint *ep,
2995 const struct sctp_association *asoc,
2996 const sctp_subtype_t type,
2997 void *arg,
2998 sctp_cmd_seq_t *commands)
2999{
3000 struct sctp_chunk *chunk = arg;
3001 sctp_sackhdr_t *sackh;
3002 __u32 ctsn;
3003
3004 if (!sctp_vtag_verify(chunk, asoc))
3005 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3006
3007 /* Make sure that the SACK chunk has a valid length. */
3008 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_sack_chunk_t)))
3009 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3010 commands);
3011
3012 /* Pull the SACK chunk from the data buffer */
3013 sackh = sctp_sm_pull_sack(chunk);
3014 /* Was this a bogus SACK? */
3015 if (!sackh)
3016 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3017 chunk->subh.sack_hdr = sackh;
3018 ctsn = ntohl(sackh->cum_tsn_ack);
3019
3020 /* i) If Cumulative TSN Ack is less than the Cumulative TSN
3021 * Ack Point, then drop the SACK. Since Cumulative TSN
3022 * Ack is monotonically increasing, a SACK whose
3023 * Cumulative TSN Ack is less than the Cumulative TSN Ack
3024 * Point indicates an out-of-order SACK.
3025 */
3026 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
3027 SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn);
3028 SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc->ctsn_ack_point);
3029 return SCTP_DISPOSITION_DISCARD;
3030 }
3031
Wei Yongjunaecedea2007-08-02 16:57:44 +08003032 /* If Cumulative TSN Ack beyond the max tsn currently
3033 * send, terminating the association and respond to the
3034 * sender with an ABORT.
3035 */
3036 if (!TSN_lt(ctsn, asoc->next_tsn))
3037 return sctp_sf_violation_ctsn(ep, asoc, type, arg, commands);
3038
Linus Torvalds1da177e2005-04-16 15:20:36 -07003039 /* Return this SACK for further processing. */
3040 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_SACKH(sackh));
3041
3042 /* Note: We do the rest of the work on the PROCESS_SACK
3043 * sideeffect.
3044 */
3045 return SCTP_DISPOSITION_CONSUME;
3046}
3047
3048/*
3049 * Generate an ABORT in response to a packet.
3050 *
Jerome Forissier047a2422005-04-28 11:58:43 -07003051 * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41
Linus Torvalds1da177e2005-04-16 15:20:36 -07003052 *
Jerome Forissier047a2422005-04-28 11:58:43 -07003053 * 8) The receiver should respond to the sender of the OOTB packet with
3054 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3055 * MUST fill in the Verification Tag field of the outbound packet
3056 * with the value found in the Verification Tag field of the OOTB
3057 * packet and set the T-bit in the Chunk Flags to indicate that the
3058 * Verification Tag is reflected. After sending this ABORT, the
3059 * receiver of the OOTB packet shall discard the OOTB packet and take
3060 * no further action.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003061 *
3062 * Verification Tag:
3063 *
3064 * The return value is the disposition of the chunk.
3065*/
Vlad Yasevichece25df2007-09-07 16:30:54 -04003066static sctp_disposition_t sctp_sf_tabort_8_4_8(const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003067 const struct sctp_association *asoc,
3068 const sctp_subtype_t type,
3069 void *arg,
3070 sctp_cmd_seq_t *commands)
3071{
3072 struct sctp_packet *packet = NULL;
3073 struct sctp_chunk *chunk = arg;
3074 struct sctp_chunk *abort;
3075
3076 packet = sctp_ootb_pkt_new(asoc, chunk);
3077
3078 if (packet) {
3079 /* Make an ABORT. The T bit will be set if the asoc
3080 * is NULL.
3081 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003082 abort = sctp_make_abort(asoc, chunk, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003083 if (!abort) {
3084 sctp_ootb_pkt_free(packet);
3085 return SCTP_DISPOSITION_NOMEM;
3086 }
3087
Jerome Forissier047a2422005-04-28 11:58:43 -07003088 /* Reflect vtag if T-Bit is set */
3089 if (sctp_test_T_bit(abort))
3090 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3091
Linus Torvalds1da177e2005-04-16 15:20:36 -07003092 /* Set the skb to the belonging sock for accounting. */
3093 abort->skb->sk = ep->base.sk;
3094
3095 sctp_packet_append_chunk(packet, abort);
3096
3097 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3098 SCTP_PACKET(packet));
3099
3100 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
3101
Vlad Yasevichd3f25962007-09-07 11:47:45 -04003102 sctp_sf_pdiscard(ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003103 return SCTP_DISPOSITION_CONSUME;
3104 }
3105
3106 return SCTP_DISPOSITION_NOMEM;
3107}
3108
3109/*
3110 * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR
3111 * event as ULP notification for each cause included in the chunk.
3112 *
3113 * API 5.3.1.3 - SCTP_REMOTE_ERROR
3114 *
3115 * The return value is the disposition of the chunk.
3116*/
3117sctp_disposition_t sctp_sf_operr_notify(const struct sctp_endpoint *ep,
3118 const struct sctp_association *asoc,
3119 const sctp_subtype_t type,
3120 void *arg,
3121 sctp_cmd_seq_t *commands)
3122{
3123 struct sctp_chunk *chunk = arg;
3124 struct sctp_ulpevent *ev;
3125
3126 if (!sctp_vtag_verify(chunk, asoc))
3127 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3128
3129 /* Make sure that the ERROR chunk has a valid length. */
3130 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
3131 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3132 commands);
3133
3134 while (chunk->chunk_end > chunk->skb->data) {
3135 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
3136 GFP_ATOMIC);
3137 if (!ev)
3138 goto nomem;
3139
3140 if (!sctp_add_cmd(commands, SCTP_CMD_EVENT_ULP,
3141 SCTP_ULPEVENT(ev))) {
3142 sctp_ulpevent_free(ev);
3143 goto nomem;
3144 }
3145
3146 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_OPERR,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003147 SCTP_CHUNK(chunk));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003148 }
3149 return SCTP_DISPOSITION_CONSUME;
3150
3151nomem:
3152 return SCTP_DISPOSITION_NOMEM;
3153}
3154
3155/*
3156 * Process an inbound SHUTDOWN ACK.
3157 *
3158 * From Section 9.2:
3159 * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3160 * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its
3161 * peer, and remove all record of the association.
3162 *
3163 * The return value is the disposition.
3164 */
3165sctp_disposition_t sctp_sf_do_9_2_final(const struct sctp_endpoint *ep,
3166 const struct sctp_association *asoc,
3167 const sctp_subtype_t type,
3168 void *arg,
3169 sctp_cmd_seq_t *commands)
3170{
3171 struct sctp_chunk *chunk = arg;
3172 struct sctp_chunk *reply;
3173 struct sctp_ulpevent *ev;
3174
3175 if (!sctp_vtag_verify(chunk, asoc))
3176 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3177
3178 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3179 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3180 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3181 commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003182 /* 10.2 H) SHUTDOWN COMPLETE notification
3183 *
3184 * When SCTP completes the shutdown procedures (section 9.2) this
3185 * notification is passed to the upper layer.
3186 */
3187 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
Vlad Yasevicha5a35e72007-03-23 11:34:08 -07003188 0, 0, 0, NULL, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003189 if (!ev)
3190 goto nomem;
3191
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07003192 /* ...send a SHUTDOWN COMPLETE chunk to its peer, */
3193 reply = sctp_make_shutdown_complete(asoc, chunk);
3194 if (!reply)
3195 goto nomem_chunk;
3196
3197 /* Do all the commands now (after allocation), so that we
3198 * have consistent state if memory allocation failes
3199 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003200 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
3201
3202 /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3203 * stop the T2-shutdown timer,
3204 */
3205 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3206 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3207
3208 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3209 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
3210
Linus Torvalds1da177e2005-04-16 15:20:36 -07003211 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3212 SCTP_STATE(SCTP_STATE_CLOSED));
3213 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
3214 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3215 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
3216
3217 /* ...and remove all record of the association. */
3218 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
3219 return SCTP_DISPOSITION_DELETE_TCB;
3220
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07003221nomem_chunk:
3222 sctp_ulpevent_free(ev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003223nomem:
3224 return SCTP_DISPOSITION_NOMEM;
3225}
3226
3227/*
Jerome Forissier047a2422005-04-28 11:58:43 -07003228 * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41.
3229 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003230 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3231 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3232 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3233 * packet must fill in the Verification Tag field of the outbound
3234 * packet with the Verification Tag received in the SHUTDOWN ACK and
Jerome Forissier047a2422005-04-28 11:58:43 -07003235 * set the T-bit in the Chunk Flags to indicate that the Verification
3236 * Tag is reflected.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003237 *
3238 * 8) The receiver should respond to the sender of the OOTB packet with
3239 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3240 * MUST fill in the Verification Tag field of the outbound packet
3241 * with the value found in the Verification Tag field of the OOTB
Jerome Forissier047a2422005-04-28 11:58:43 -07003242 * packet and set the T-bit in the Chunk Flags to indicate that the
3243 * Verification Tag is reflected. After sending this ABORT, the
3244 * receiver of the OOTB packet shall discard the OOTB packet and take
3245 * no further action.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003246 */
3247sctp_disposition_t sctp_sf_ootb(const struct sctp_endpoint *ep,
3248 const struct sctp_association *asoc,
3249 const sctp_subtype_t type,
3250 void *arg,
3251 sctp_cmd_seq_t *commands)
3252{
3253 struct sctp_chunk *chunk = arg;
3254 struct sk_buff *skb = chunk->skb;
3255 sctp_chunkhdr_t *ch;
3256 __u8 *ch_end;
3257 int ootb_shut_ack = 0;
3258
3259 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES);
3260
3261 ch = (sctp_chunkhdr_t *) chunk->chunk_hdr;
3262 do {
Vlad Yasevichece25df2007-09-07 16:30:54 -04003263 /* Report violation if the chunk is less then minimal */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003264 if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t))
Vlad Yasevichece25df2007-09-07 16:30:54 -04003265 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3266 commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003267
Vlad Yasevichece25df2007-09-07 16:30:54 -04003268 /* Now that we know we at least have a chunk header,
3269 * do things that are type appropriate.
3270 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003271 if (SCTP_CID_SHUTDOWN_ACK == ch->type)
3272 ootb_shut_ack = 1;
3273
3274 /* RFC 2960, Section 3.3.7
3275 * Moreover, under any circumstances, an endpoint that
3276 * receives an ABORT MUST NOT respond to that ABORT by
3277 * sending an ABORT of its own.
3278 */
3279 if (SCTP_CID_ABORT == ch->type)
3280 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003281
Vlad Yasevichece25df2007-09-07 16:30:54 -04003282 /* Report violation if chunk len overflows */
3283 ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
3284 if (ch_end > skb_tail_pointer(skb))
3285 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3286 commands);
3287
Linus Torvalds1da177e2005-04-16 15:20:36 -07003288 ch = (sctp_chunkhdr_t *) ch_end;
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07003289 } while (ch_end < skb_tail_pointer(skb));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003290
3291 if (ootb_shut_ack)
Vlad Yasevichd3f25962007-09-07 11:47:45 -04003292 return sctp_sf_shut_8_4_5(ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003293 else
Vlad Yasevichd3f25962007-09-07 11:47:45 -04003294 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003295}
3296
3297/*
3298 * Handle an "Out of the blue" SHUTDOWN ACK.
3299 *
Jerome Forissier047a2422005-04-28 11:58:43 -07003300 * Section: 8.4 5, sctpimpguide 2.41.
3301 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003302 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
Jerome Forissier047a2422005-04-28 11:58:43 -07003303 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3304 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3305 * packet must fill in the Verification Tag field of the outbound
3306 * packet with the Verification Tag received in the SHUTDOWN ACK and
3307 * set the T-bit in the Chunk Flags to indicate that the Verification
3308 * Tag is reflected.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003309 *
3310 * Inputs
3311 * (endpoint, asoc, type, arg, commands)
3312 *
3313 * Outputs
3314 * (sctp_disposition_t)
3315 *
3316 * The return value is the disposition of the chunk.
3317 */
3318static sctp_disposition_t sctp_sf_shut_8_4_5(const struct sctp_endpoint *ep,
3319 const struct sctp_association *asoc,
3320 const sctp_subtype_t type,
3321 void *arg,
3322 sctp_cmd_seq_t *commands)
3323{
3324 struct sctp_packet *packet = NULL;
3325 struct sctp_chunk *chunk = arg;
3326 struct sctp_chunk *shut;
3327
3328 packet = sctp_ootb_pkt_new(asoc, chunk);
3329
3330 if (packet) {
3331 /* Make an SHUTDOWN_COMPLETE.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003332 * The T bit will be set if the asoc is NULL.
3333 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003334 shut = sctp_make_shutdown_complete(asoc, chunk);
3335 if (!shut) {
3336 sctp_ootb_pkt_free(packet);
3337 return SCTP_DISPOSITION_NOMEM;
3338 }
3339
Jerome Forissier047a2422005-04-28 11:58:43 -07003340 /* Reflect vtag if T-Bit is set */
3341 if (sctp_test_T_bit(shut))
3342 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3343
Linus Torvalds1da177e2005-04-16 15:20:36 -07003344 /* Set the skb to the belonging sock for accounting. */
3345 shut->skb->sk = ep->base.sk;
3346
3347 sctp_packet_append_chunk(packet, shut);
3348
3349 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3350 SCTP_PACKET(packet));
3351
3352 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
3353
3354 /* If the chunk length is invalid, we don't want to process
3355 * the reset of the packet.
3356 */
3357 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3358 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3359
Vlad Yasevichd3f25962007-09-07 11:47:45 -04003360 /* We need to discard the rest of the packet to prevent
3361 * potential bomming attacks from additional bundled chunks.
3362 * This is documented in SCTP Threats ID.
3363 */
3364 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003365 }
3366
3367 return SCTP_DISPOSITION_NOMEM;
3368}
3369
3370/*
3371 * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state.
3372 *
3373 * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK
3374 * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the
3375 * procedures in section 8.4 SHOULD be followed, in other words it
3376 * should be treated as an Out Of The Blue packet.
3377 * [This means that we do NOT check the Verification Tag on these
3378 * chunks. --piggy ]
3379 *
3380 */
3381sctp_disposition_t sctp_sf_do_8_5_1_E_sa(const struct sctp_endpoint *ep,
3382 const struct sctp_association *asoc,
3383 const sctp_subtype_t type,
3384 void *arg,
3385 sctp_cmd_seq_t *commands)
3386{
Vlad Yasevichece25df2007-09-07 16:30:54 -04003387 struct sctp_chunk *chunk = arg;
3388
3389 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3390 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3391 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3392 commands);
3393
Linus Torvalds1da177e2005-04-16 15:20:36 -07003394 /* Although we do have an association in this case, it corresponds
3395 * to a restarted association. So the packet is treated as an OOTB
3396 * packet and the state function that handles OOTB SHUTDOWN_ACK is
3397 * called with a NULL association.
3398 */
3399 return sctp_sf_shut_8_4_5(ep, NULL, type, arg, commands);
3400}
3401
3402/* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */
3403sctp_disposition_t sctp_sf_do_asconf(const struct sctp_endpoint *ep,
3404 const struct sctp_association *asoc,
3405 const sctp_subtype_t type, void *arg,
3406 sctp_cmd_seq_t *commands)
3407{
3408 struct sctp_chunk *chunk = arg;
3409 struct sctp_chunk *asconf_ack = NULL;
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003410 struct sctp_paramhdr *err_param = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003411 sctp_addiphdr_t *hdr;
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003412 union sctp_addr_param *addr_param;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003413 __u32 serial;
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003414 int length;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003415
3416 if (!sctp_vtag_verify(chunk, asoc)) {
3417 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3418 SCTP_NULL());
3419 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3420 }
3421
Vlad Yasevich6afd2e82007-12-20 14:08:04 -08003422 /* ADD-IP: Section 4.1.1
3423 * This chunk MUST be sent in an authenticated way by using
3424 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3425 * is received unauthenticated it MUST be silently discarded as
3426 * described in [I-D.ietf-tsvwg-sctp-auth].
3427 */
3428 if (!sctp_addip_noauth && !chunk->auth)
3429 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
3430
Linus Torvalds1da177e2005-04-16 15:20:36 -07003431 /* Make sure that the ASCONF ADDIP chunk has a valid length. */
3432 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_addip_chunk_t)))
3433 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3434 commands);
3435
3436 hdr = (sctp_addiphdr_t *)chunk->skb->data;
3437 serial = ntohl(hdr->serial);
3438
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003439 addr_param = (union sctp_addr_param *)hdr->params;
3440 length = ntohs(addr_param->p.length);
3441 if (length < sizeof(sctp_paramhdr_t))
3442 return sctp_sf_violation_paramlen(ep, asoc, type,
3443 (void *)addr_param, commands);
3444
3445 /* Verify the ASCONF chunk before processing it. */
3446 if (!sctp_verify_asconf(asoc,
Vlad Yasevicha08de642007-12-20 14:11:47 -08003447 (sctp_paramhdr_t *)((void *)addr_param + length),
3448 (void *)chunk->chunk_end,
3449 &err_param))
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003450 return sctp_sf_violation_paramlen(ep, asoc, type,
Vlad Yasevicha08de642007-12-20 14:11:47 -08003451 (void *)&err_param, commands);
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003452
Vlad Yasevicha08de642007-12-20 14:11:47 -08003453 /* ADDIP 5.2 E1) Compare the value of the serial number to the value
Linus Torvalds1da177e2005-04-16 15:20:36 -07003454 * the endpoint stored in a new association variable
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003455 * 'Peer-Serial-Number'.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003456 */
3457 if (serial == asoc->peer.addip_serial + 1) {
Vlad Yasevicha08de642007-12-20 14:11:47 -08003458 /* If this is the first instance of ASCONF in the packet,
3459 * we can clean our old ASCONF-ACKs.
3460 */
3461 if (!chunk->has_asconf)
3462 sctp_assoc_clean_asconf_ack_cache(asoc);
3463
3464 /* ADDIP 5.2 E4) When the Sequence Number matches the next one
3465 * expected, process the ASCONF as described below and after
3466 * processing the ASCONF Chunk, append an ASCONF-ACK Chunk to
3467 * the response packet and cache a copy of it (in the event it
3468 * later needs to be retransmitted).
3469 *
3470 * Essentially, do V1-V5.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003471 */
3472 asconf_ack = sctp_process_asconf((struct sctp_association *)
3473 asoc, chunk);
3474 if (!asconf_ack)
3475 return SCTP_DISPOSITION_NOMEM;
Vlad Yasevicha08de642007-12-20 14:11:47 -08003476 } else if (serial < asoc->peer.addip_serial + 1) {
3477 /* ADDIP 5.2 E2)
3478 * If the value found in the Sequence Number is less than the
3479 * ('Peer- Sequence-Number' + 1), simply skip to the next
3480 * ASCONF, and include in the outbound response packet
3481 * any previously cached ASCONF-ACK response that was
3482 * sent and saved that matches the Sequence Number of the
3483 * ASCONF. Note: It is possible that no cached ASCONF-ACK
3484 * Chunk exists. This will occur when an older ASCONF
3485 * arrives out of order. In such a case, the receiver
3486 * should skip the ASCONF Chunk and not include ASCONF-ACK
3487 * Chunk for that chunk.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003488 */
Vlad Yasevicha08de642007-12-20 14:11:47 -08003489 asconf_ack = sctp_assoc_lookup_asconf_ack(asoc, hdr->serial);
3490 if (!asconf_ack)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003491 return SCTP_DISPOSITION_DISCARD;
3492 } else {
Vlad Yasevicha08de642007-12-20 14:11:47 -08003493 /* ADDIP 5.2 E5) Otherwise, the ASCONF Chunk is discarded since
Linus Torvalds1da177e2005-04-16 15:20:36 -07003494 * it must be either a stale packet or from an attacker.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003495 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003496 return SCTP_DISPOSITION_DISCARD;
3497 }
3498
Vlad Yasevicha08de642007-12-20 14:11:47 -08003499 /* ADDIP 5.2 E6) The destination address of the SCTP packet
3500 * containing the ASCONF-ACK Chunks MUST be the source address of
3501 * the SCTP packet that held the ASCONF Chunks.
3502 *
3503 * To do this properly, we'll set the destination address of the chunk
3504 * and at the transmit time, will try look up the transport to use.
3505 * Since ASCONFs may be bundled, the correct transport may not be
3506 * created untill we process the entire packet, thus this workaround.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003507 */
Vlad Yasevicha08de642007-12-20 14:11:47 -08003508 asconf_ack->dest = chunk->source;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003509 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(asconf_ack));
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003510
Linus Torvalds1da177e2005-04-16 15:20:36 -07003511 return SCTP_DISPOSITION_CONSUME;
3512}
3513
3514/*
3515 * ADDIP Section 4.3 General rules for address manipulation
3516 * When building TLV parameters for the ASCONF Chunk that will add or
3517 * delete IP addresses the D0 to D13 rules should be applied:
3518 */
3519sctp_disposition_t sctp_sf_do_asconf_ack(const struct sctp_endpoint *ep,
3520 const struct sctp_association *asoc,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003521 const sctp_subtype_t type, void *arg,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003522 sctp_cmd_seq_t *commands)
3523{
3524 struct sctp_chunk *asconf_ack = arg;
3525 struct sctp_chunk *last_asconf = asoc->addip_last_asconf;
3526 struct sctp_chunk *abort;
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003527 struct sctp_paramhdr *err_param = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003528 sctp_addiphdr_t *addip_hdr;
3529 __u32 sent_serial, rcvd_serial;
3530
3531 if (!sctp_vtag_verify(asconf_ack, asoc)) {
3532 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3533 SCTP_NULL());
3534 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3535 }
3536
Vlad Yasevich6afd2e82007-12-20 14:08:04 -08003537 /* ADD-IP, Section 4.1.2:
3538 * This chunk MUST be sent in an authenticated way by using
3539 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3540 * is received unauthenticated it MUST be silently discarded as
3541 * described in [I-D.ietf-tsvwg-sctp-auth].
3542 */
3543 if (!sctp_addip_noauth && !asconf_ack->auth)
3544 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
3545
Linus Torvalds1da177e2005-04-16 15:20:36 -07003546 /* Make sure that the ADDIP chunk has a valid length. */
3547 if (!sctp_chunk_length_valid(asconf_ack, sizeof(sctp_addip_chunk_t)))
3548 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3549 commands);
3550
3551 addip_hdr = (sctp_addiphdr_t *)asconf_ack->skb->data;
3552 rcvd_serial = ntohl(addip_hdr->serial);
3553
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003554 /* Verify the ASCONF-ACK chunk before processing it. */
3555 if (!sctp_verify_asconf(asoc,
3556 (sctp_paramhdr_t *)addip_hdr->params,
3557 (void *)asconf_ack->chunk_end,
3558 &err_param))
3559 return sctp_sf_violation_paramlen(ep, asoc, type,
3560 (void *)&err_param, commands);
3561
Linus Torvalds1da177e2005-04-16 15:20:36 -07003562 if (last_asconf) {
3563 addip_hdr = (sctp_addiphdr_t *)last_asconf->subh.addip_hdr;
3564 sent_serial = ntohl(addip_hdr->serial);
3565 } else {
3566 sent_serial = asoc->addip_serial - 1;
3567 }
3568
3569 /* D0) If an endpoint receives an ASCONF-ACK that is greater than or
3570 * equal to the next serial number to be used but no ASCONF chunk is
3571 * outstanding the endpoint MUST ABORT the association. Note that a
3572 * sequence number is greater than if it is no more than 2^^31-1
3573 * larger than the current sequence number (using serial arithmetic).
3574 */
3575 if (ADDIP_SERIAL_gte(rcvd_serial, sent_serial + 1) &&
3576 !(asoc->addip_last_asconf)) {
3577 abort = sctp_make_abort(asoc, asconf_ack,
3578 sizeof(sctp_errhdr_t));
3579 if (abort) {
Wei Yongjun00f1c2d2007-08-21 15:50:01 +08003580 sctp_init_cause(abort, SCTP_ERROR_ASCONF_ACK, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003581 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3582 SCTP_CHUNK(abort));
3583 }
3584 /* We are going to ABORT, so we might as well stop
3585 * processing the rest of the chunks in the packet.
3586 */
3587 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3588 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3589 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07003590 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003591 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003592 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08003593 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003594 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
3595 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3596 return SCTP_DISPOSITION_ABORT;
3597 }
3598
3599 if ((rcvd_serial == sent_serial) && asoc->addip_last_asconf) {
3600 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3601 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3602
3603 if (!sctp_process_asconf_ack((struct sctp_association *)asoc,
3604 asconf_ack))
3605 return SCTP_DISPOSITION_CONSUME;
3606
3607 abort = sctp_make_abort(asoc, asconf_ack,
3608 sizeof(sctp_errhdr_t));
3609 if (abort) {
Wei Yongjun00f1c2d2007-08-21 15:50:01 +08003610 sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003611 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3612 SCTP_CHUNK(abort));
3613 }
3614 /* We are going to ABORT, so we might as well stop
3615 * processing the rest of the chunks in the packet.
3616 */
3617 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07003618 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003619 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003620 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08003621 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003622 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
3623 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3624 return SCTP_DISPOSITION_ABORT;
3625 }
3626
3627 return SCTP_DISPOSITION_DISCARD;
3628}
3629
3630/*
3631 * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP
3632 *
3633 * When a FORWARD TSN chunk arrives, the data receiver MUST first update
3634 * its cumulative TSN point to the value carried in the FORWARD TSN
3635 * chunk, and then MUST further advance its cumulative TSN point locally
3636 * if possible.
3637 * After the above processing, the data receiver MUST stop reporting any
3638 * missing TSNs earlier than or equal to the new cumulative TSN point.
3639 *
3640 * Verification Tag: 8.5 Verification Tag [Normal verification]
3641 *
3642 * The return value is the disposition of the chunk.
3643 */
3644sctp_disposition_t sctp_sf_eat_fwd_tsn(const struct sctp_endpoint *ep,
3645 const struct sctp_association *asoc,
3646 const sctp_subtype_t type,
3647 void *arg,
3648 sctp_cmd_seq_t *commands)
3649{
3650 struct sctp_chunk *chunk = arg;
3651 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
3652 __u16 len;
3653 __u32 tsn;
3654
3655 if (!sctp_vtag_verify(chunk, asoc)) {
3656 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3657 SCTP_NULL());
3658 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3659 }
3660
3661 /* Make sure that the FORWARD_TSN chunk has valid length. */
3662 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
3663 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3664 commands);
3665
3666 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3667 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3668 len = ntohs(chunk->chunk_hdr->length);
3669 len -= sizeof(struct sctp_chunkhdr);
3670 skb_pull(chunk->skb, len);
3671
3672 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
3673 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __FUNCTION__, tsn);
3674
3675 /* The TSN is too high--silently discard the chunk and count on it
3676 * getting retransmitted later.
3677 */
3678 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3679 goto discard_noforce;
3680
3681 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3682 if (len > sizeof(struct sctp_fwdtsn_hdr))
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003683 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003684 SCTP_CHUNK(chunk));
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003685
Linus Torvalds1da177e2005-04-16 15:20:36 -07003686 /* Count this as receiving DATA. */
3687 if (asoc->autoclose) {
3688 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3689 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
3690 }
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003691
Linus Torvalds1da177e2005-04-16 15:20:36 -07003692 /* FIXME: For now send a SACK, but DATA processing may
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003693 * send another.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003694 */
3695 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
Linus Torvalds1da177e2005-04-16 15:20:36 -07003696
3697 return SCTP_DISPOSITION_CONSUME;
3698
3699discard_noforce:
3700 return SCTP_DISPOSITION_DISCARD;
3701}
3702
3703sctp_disposition_t sctp_sf_eat_fwd_tsn_fast(
3704 const struct sctp_endpoint *ep,
3705 const struct sctp_association *asoc,
3706 const sctp_subtype_t type,
3707 void *arg,
3708 sctp_cmd_seq_t *commands)
3709{
3710 struct sctp_chunk *chunk = arg;
3711 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
3712 __u16 len;
3713 __u32 tsn;
3714
3715 if (!sctp_vtag_verify(chunk, asoc)) {
3716 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3717 SCTP_NULL());
3718 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3719 }
3720
3721 /* Make sure that the FORWARD_TSN chunk has a valid length. */
3722 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
3723 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3724 commands);
3725
3726 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3727 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3728 len = ntohs(chunk->chunk_hdr->length);
3729 len -= sizeof(struct sctp_chunkhdr);
3730 skb_pull(chunk->skb, len);
3731
3732 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
3733 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __FUNCTION__, tsn);
3734
3735 /* The TSN is too high--silently discard the chunk and count on it
3736 * getting retransmitted later.
3737 */
3738 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3739 goto gen_shutdown;
3740
3741 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3742 if (len > sizeof(struct sctp_fwdtsn_hdr))
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003743 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003744 SCTP_CHUNK(chunk));
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003745
Linus Torvalds1da177e2005-04-16 15:20:36 -07003746 /* Go a head and force a SACK, since we are shutting down. */
3747gen_shutdown:
3748 /* Implementor's Guide.
3749 *
3750 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3751 * respond to each received packet containing one or more DATA chunk(s)
3752 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3753 */
3754 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
3755 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3756 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3757 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3758
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003759 return SCTP_DISPOSITION_CONSUME;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003760}
3761
3762/*
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07003763 * SCTP-AUTH Section 6.3 Receving authenticated chukns
3764 *
3765 * The receiver MUST use the HMAC algorithm indicated in the HMAC
3766 * Identifier field. If this algorithm was not specified by the
3767 * receiver in the HMAC-ALGO parameter in the INIT or INIT-ACK chunk
3768 * during association setup, the AUTH chunk and all chunks after it MUST
3769 * be discarded and an ERROR chunk SHOULD be sent with the error cause
3770 * defined in Section 4.1.
3771 *
3772 * If an endpoint with no shared key receives a Shared Key Identifier
3773 * other than 0, it MUST silently discard all authenticated chunks. If
3774 * the endpoint has at least one endpoint pair shared key for the peer,
3775 * it MUST use the key specified by the Shared Key Identifier if a
3776 * key has been configured for that Shared Key Identifier. If no
3777 * endpoint pair shared key has been configured for that Shared Key
3778 * Identifier, all authenticated chunks MUST be silently discarded.
3779 *
3780 * Verification Tag: 8.5 Verification Tag [Normal verification]
3781 *
3782 * The return value is the disposition of the chunk.
3783 */
3784static sctp_ierror_t sctp_sf_authenticate(const struct sctp_endpoint *ep,
3785 const struct sctp_association *asoc,
3786 const sctp_subtype_t type,
3787 struct sctp_chunk *chunk)
3788{
3789 struct sctp_authhdr *auth_hdr;
3790 struct sctp_hmac *hmac;
3791 unsigned int sig_len;
3792 __u16 key_id;
3793 __u8 *save_digest;
3794 __u8 *digest;
3795
3796 /* Pull in the auth header, so we can do some more verification */
3797 auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
3798 chunk->subh.auth_hdr = auth_hdr;
3799 skb_pull(chunk->skb, sizeof(struct sctp_authhdr));
3800
3801 /* Make sure that we suport the HMAC algorithm from the auth
3802 * chunk.
3803 */
3804 if (!sctp_auth_asoc_verify_hmac_id(asoc, auth_hdr->hmac_id))
3805 return SCTP_IERROR_AUTH_BAD_HMAC;
3806
3807 /* Make sure that the provided shared key identifier has been
3808 * configured
3809 */
3810 key_id = ntohs(auth_hdr->shkey_id);
3811 if (key_id != asoc->active_key_id && !sctp_auth_get_shkey(asoc, key_id))
3812 return SCTP_IERROR_AUTH_BAD_KEYID;
3813
3814
3815 /* Make sure that the length of the signature matches what
3816 * we expect.
3817 */
3818 sig_len = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_auth_chunk_t);
3819 hmac = sctp_auth_get_hmac(ntohs(auth_hdr->hmac_id));
3820 if (sig_len != hmac->hmac_len)
3821 return SCTP_IERROR_PROTO_VIOLATION;
3822
3823 /* Now that we've done validation checks, we can compute and
3824 * verify the hmac. The steps involved are:
3825 * 1. Save the digest from the chunk.
3826 * 2. Zero out the digest in the chunk.
3827 * 3. Compute the new digest
3828 * 4. Compare saved and new digests.
3829 */
3830 digest = auth_hdr->hmac;
3831 skb_pull(chunk->skb, sig_len);
3832
3833 save_digest = kmemdup(digest, sig_len, GFP_ATOMIC);
3834 if (!save_digest)
3835 goto nomem;
3836
3837 memset(digest, 0, sig_len);
3838
3839 sctp_auth_calculate_hmac(asoc, chunk->skb,
3840 (struct sctp_auth_chunk *)chunk->chunk_hdr,
3841 GFP_ATOMIC);
3842
3843 /* Discard the packet if the digests do not match */
3844 if (memcmp(save_digest, digest, sig_len)) {
3845 kfree(save_digest);
3846 return SCTP_IERROR_BAD_SIG;
3847 }
3848
3849 kfree(save_digest);
3850 chunk->auth = 1;
3851
3852 return SCTP_IERROR_NO_ERROR;
3853nomem:
3854 return SCTP_IERROR_NOMEM;
3855}
3856
3857sctp_disposition_t sctp_sf_eat_auth(const struct sctp_endpoint *ep,
3858 const struct sctp_association *asoc,
3859 const sctp_subtype_t type,
3860 void *arg,
3861 sctp_cmd_seq_t *commands)
3862{
3863 struct sctp_authhdr *auth_hdr;
3864 struct sctp_chunk *chunk = arg;
3865 struct sctp_chunk *err_chunk;
3866 sctp_ierror_t error;
3867
Wei Yongjund2f19fa2008-02-05 03:02:26 -08003868 /* Make sure that the peer has AUTH capable */
3869 if (!asoc->peer.auth_capable)
3870 return sctp_sf_unk_chunk(ep, asoc, type, arg, commands);
3871
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07003872 if (!sctp_vtag_verify(chunk, asoc)) {
3873 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3874 SCTP_NULL());
3875 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3876 }
3877
3878 /* Make sure that the AUTH chunk has valid length. */
3879 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_auth_chunk)))
3880 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3881 commands);
3882
3883 auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
3884 error = sctp_sf_authenticate(ep, asoc, type, chunk);
3885 switch (error) {
3886 case SCTP_IERROR_AUTH_BAD_HMAC:
3887 /* Generate the ERROR chunk and discard the rest
3888 * of the packet
3889 */
3890 err_chunk = sctp_make_op_error(asoc, chunk,
3891 SCTP_ERROR_UNSUP_HMAC,
3892 &auth_hdr->hmac_id,
3893 sizeof(__u16));
3894 if (err_chunk) {
3895 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3896 SCTP_CHUNK(err_chunk));
3897 }
3898 /* Fall Through */
3899 case SCTP_IERROR_AUTH_BAD_KEYID:
3900 case SCTP_IERROR_BAD_SIG:
3901 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3902 break;
3903 case SCTP_IERROR_PROTO_VIOLATION:
3904 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3905 commands);
3906 break;
3907 case SCTP_IERROR_NOMEM:
3908 return SCTP_DISPOSITION_NOMEM;
3909 default:
3910 break;
3911 }
3912
Vlad Yasevich65b07e52007-09-16 19:34:00 -07003913 if (asoc->active_key_id != ntohs(auth_hdr->shkey_id)) {
3914 struct sctp_ulpevent *ev;
3915
3916 ev = sctp_ulpevent_make_authkey(asoc, ntohs(auth_hdr->shkey_id),
3917 SCTP_AUTH_NEWKEY, GFP_ATOMIC);
3918
3919 if (!ev)
3920 return -ENOMEM;
3921
3922 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
3923 SCTP_ULPEVENT(ev));
3924 }
3925
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07003926 return SCTP_DISPOSITION_CONSUME;
3927}
3928
3929/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07003930 * Process an unknown chunk.
3931 *
3932 * Section: 3.2. Also, 2.1 in the implementor's guide.
3933 *
3934 * Chunk Types are encoded such that the highest-order two bits specify
3935 * the action that must be taken if the processing endpoint does not
3936 * recognize the Chunk Type.
3937 *
3938 * 00 - Stop processing this SCTP packet and discard it, do not process
3939 * any further chunks within it.
3940 *
3941 * 01 - Stop processing this SCTP packet and discard it, do not process
3942 * any further chunks within it, and report the unrecognized
3943 * chunk in an 'Unrecognized Chunk Type'.
3944 *
3945 * 10 - Skip this chunk and continue processing.
3946 *
3947 * 11 - Skip this chunk and continue processing, but report in an ERROR
3948 * Chunk using the 'Unrecognized Chunk Type' cause of error.
3949 *
3950 * The return value is the disposition of the chunk.
3951 */
3952sctp_disposition_t sctp_sf_unk_chunk(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_chunk *unk_chunk = arg;
3959 struct sctp_chunk *err_chunk;
3960 sctp_chunkhdr_t *hdr;
3961
3962 SCTP_DEBUG_PRINTK("Processing the unknown chunk id %d.\n", type.chunk);
3963
3964 if (!sctp_vtag_verify(unk_chunk, asoc))
3965 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3966
3967 /* Make sure that the chunk has a valid length.
3968 * Since we don't know the chunk type, we use a general
3969 * chunkhdr structure to make a comparison.
3970 */
3971 if (!sctp_chunk_length_valid(unk_chunk, sizeof(sctp_chunkhdr_t)))
3972 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3973 commands);
3974
3975 switch (type.chunk & SCTP_CID_ACTION_MASK) {
3976 case SCTP_CID_ACTION_DISCARD:
3977 /* Discard the packet. */
3978 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3979 break;
3980 case SCTP_CID_ACTION_DISCARD_ERR:
3981 /* Discard the packet. */
3982 sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3983
3984 /* Generate an ERROR chunk as response. */
3985 hdr = unk_chunk->chunk_hdr;
3986 err_chunk = sctp_make_op_error(asoc, unk_chunk,
3987 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
3988 WORD_ROUND(ntohs(hdr->length)));
3989 if (err_chunk) {
3990 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3991 SCTP_CHUNK(err_chunk));
3992 }
3993 return SCTP_DISPOSITION_CONSUME;
3994 break;
3995 case SCTP_CID_ACTION_SKIP:
3996 /* Skip the chunk. */
3997 return SCTP_DISPOSITION_DISCARD;
3998 break;
3999 case SCTP_CID_ACTION_SKIP_ERR:
4000 /* Generate an ERROR chunk as response. */
4001 hdr = unk_chunk->chunk_hdr;
4002 err_chunk = sctp_make_op_error(asoc, unk_chunk,
4003 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
4004 WORD_ROUND(ntohs(hdr->length)));
4005 if (err_chunk) {
4006 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4007 SCTP_CHUNK(err_chunk));
4008 }
4009 /* Skip the chunk. */
4010 return SCTP_DISPOSITION_CONSUME;
4011 break;
4012 default:
4013 break;
4014 }
4015
4016 return SCTP_DISPOSITION_DISCARD;
4017}
4018
4019/*
4020 * Discard the chunk.
4021 *
4022 * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2
4023 * [Too numerous to mention...]
4024 * Verification Tag: No verification needed.
4025 * Inputs
4026 * (endpoint, asoc, chunk)
4027 *
4028 * Outputs
4029 * (asoc, reply_msg, msg_up, timers, counters)
4030 *
4031 * The return value is the disposition of the chunk.
4032 */
4033sctp_disposition_t sctp_sf_discard_chunk(const struct sctp_endpoint *ep,
4034 const struct sctp_association *asoc,
4035 const sctp_subtype_t type,
4036 void *arg,
4037 sctp_cmd_seq_t *commands)
4038{
Vlad Yasevichece25df2007-09-07 16:30:54 -04004039 struct sctp_chunk *chunk = arg;
4040
4041 /* Make sure that the chunk has a valid length.
4042 * Since we don't know the chunk type, we use a general
4043 * chunkhdr structure to make a comparison.
4044 */
4045 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
4046 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
4047 commands);
4048
Linus Torvalds1da177e2005-04-16 15:20:36 -07004049 SCTP_DEBUG_PRINTK("Chunk %d is discarded\n", type.chunk);
4050 return SCTP_DISPOSITION_DISCARD;
4051}
4052
4053/*
4054 * Discard the whole packet.
4055 *
4056 * Section: 8.4 2)
4057 *
4058 * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST
4059 * silently discard the OOTB packet and take no further action.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004060 *
4061 * Verification Tag: No verification necessary
4062 *
4063 * Inputs
4064 * (endpoint, asoc, chunk)
4065 *
4066 * Outputs
4067 * (asoc, reply_msg, msg_up, timers, counters)
4068 *
4069 * The return value is the disposition of the chunk.
4070 */
4071sctp_disposition_t sctp_sf_pdiscard(const struct sctp_endpoint *ep,
4072 const struct sctp_association *asoc,
4073 const sctp_subtype_t type,
4074 void *arg,
4075 sctp_cmd_seq_t *commands)
4076{
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07004077 SCTP_INC_STATS(SCTP_MIB_IN_PKT_DISCARDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004078 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
4079
4080 return SCTP_DISPOSITION_CONSUME;
4081}
4082
4083
4084/*
4085 * The other end is violating protocol.
4086 *
4087 * Section: Not specified
4088 * Verification Tag: Not specified
4089 * Inputs
4090 * (endpoint, asoc, chunk)
4091 *
4092 * Outputs
4093 * (asoc, reply_msg, msg_up, timers, counters)
4094 *
4095 * We simply tag the chunk as a violation. The state machine will log
4096 * the violation and continue.
4097 */
4098sctp_disposition_t sctp_sf_violation(const struct sctp_endpoint *ep,
4099 const struct sctp_association *asoc,
4100 const sctp_subtype_t type,
4101 void *arg,
4102 sctp_cmd_seq_t *commands)
4103{
Vlad Yasevichece25df2007-09-07 16:30:54 -04004104 struct sctp_chunk *chunk = arg;
4105
4106 /* Make sure that the chunk has a valid length. */
4107 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
4108 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
4109 commands);
4110
Linus Torvalds1da177e2005-04-16 15:20:36 -07004111 return SCTP_DISPOSITION_VIOLATION;
4112}
4113
Linus Torvalds1da177e2005-04-16 15:20:36 -07004114/*
Wei Yongjunaecedea2007-08-02 16:57:44 +08004115 * Common function to handle a protocol violation.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004116 */
Wei Yongjunaecedea2007-08-02 16:57:44 +08004117static sctp_disposition_t sctp_sf_abort_violation(
Vlad Yasevichece25df2007-09-07 16:30:54 -04004118 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07004119 const struct sctp_association *asoc,
Linus Torvalds1da177e2005-04-16 15:20:36 -07004120 void *arg,
Wei Yongjunaecedea2007-08-02 16:57:44 +08004121 sctp_cmd_seq_t *commands,
4122 const __u8 *payload,
4123 const size_t paylen)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004124{
Vlad Yasevichece25df2007-09-07 16:30:54 -04004125 struct sctp_packet *packet = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004126 struct sctp_chunk *chunk = arg;
4127 struct sctp_chunk *abort = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004128
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07004129 /* SCTP-AUTH, Section 6.3:
4130 * It should be noted that if the receiver wants to tear
4131 * down an association in an authenticated way only, the
4132 * handling of malformed packets should not result in
4133 * tearing down the association.
4134 *
4135 * This means that if we only want to abort associations
4136 * in an authenticated way (i.e AUTH+ABORT), then we
Oliver Pinterac461a02008-02-03 17:52:41 +02004137 * can't destroy this association just becuase the packet
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07004138 * was malformed.
4139 */
4140 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
4141 goto discard;
4142
Jesper Juhl9abed242007-11-11 23:57:49 +01004143 /* Make the abort chunk. */
4144 abort = sctp_make_abort_violation(asoc, chunk, payload, paylen);
4145 if (!abort)
4146 goto nomem;
4147
Vlad Yasevichece25df2007-09-07 16:30:54 -04004148 if (asoc) {
4149 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4150 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004151
Vlad Yasevichece25df2007-09-07 16:30:54 -04004152 if (asoc->state <= SCTP_STATE_COOKIE_ECHOED) {
4153 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4154 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4155 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4156 SCTP_ERROR(ECONNREFUSED));
4157 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
4158 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4159 } else {
4160 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4161 SCTP_ERROR(ECONNABORTED));
4162 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4163 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4164 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
4165 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07004166 } else {
Vlad Yasevichece25df2007-09-07 16:30:54 -04004167 packet = sctp_ootb_pkt_new(asoc, chunk);
4168
4169 if (!packet)
4170 goto nomem_pkt;
4171
4172 if (sctp_test_T_bit(abort))
4173 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
4174
4175 abort->skb->sk = ep->base.sk;
4176
4177 sctp_packet_append_chunk(packet, abort);
4178
4179 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
4180 SCTP_PACKET(packet));
4181
4182 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004183 }
4184
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07004185discard:
Vlad Yasevichece25df2007-09-07 16:30:54 -04004186 sctp_sf_pdiscard(ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004187
4188 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09004189
Linus Torvalds1da177e2005-04-16 15:20:36 -07004190 return SCTP_DISPOSITION_ABORT;
4191
Vlad Yasevichece25df2007-09-07 16:30:54 -04004192nomem_pkt:
4193 sctp_chunk_free(abort);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004194nomem:
4195 return SCTP_DISPOSITION_NOMEM;
4196}
4197
Wei Yongjunaecedea2007-08-02 16:57:44 +08004198/*
4199 * Handle a protocol violation when the chunk length is invalid.
4200 * "Invalid" length is identified as smaller then the minimal length a
4201 * given chunk can be. For example, a SACK chunk has invalid length
4202 * if it's length is set to be smaller then the size of sctp_sack_chunk_t.
4203 *
4204 * We inform the other end by sending an ABORT with a Protocol Violation
4205 * error code.
4206 *
4207 * Section: Not specified
4208 * Verification Tag: Nothing to do
4209 * Inputs
4210 * (endpoint, asoc, chunk)
4211 *
4212 * Outputs
4213 * (reply_msg, msg_up, counters)
4214 *
4215 * Generate an ABORT chunk and terminate the association.
4216 */
4217static sctp_disposition_t sctp_sf_violation_chunklen(
4218 const struct sctp_endpoint *ep,
4219 const struct sctp_association *asoc,
4220 const sctp_subtype_t type,
4221 void *arg,
4222 sctp_cmd_seq_t *commands)
4223{
4224 char err_str[]="The following chunk had invalid length:";
4225
Vlad Yasevichece25df2007-09-07 16:30:54 -04004226 return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
Wei Yongjunaecedea2007-08-02 16:57:44 +08004227 sizeof(err_str));
4228}
4229
Wei Yongjun6f4c6182007-09-19 17:19:52 +08004230/*
4231 * Handle a protocol violation when the parameter length is invalid.
4232 * "Invalid" length is identified as smaller then the minimal length a
4233 * given parameter can be.
4234 */
4235static sctp_disposition_t sctp_sf_violation_paramlen(
4236 const struct sctp_endpoint *ep,
4237 const struct sctp_association *asoc,
4238 const sctp_subtype_t type,
4239 void *arg,
4240 sctp_cmd_seq_t *commands) {
4241 char err_str[] = "The following parameter had invalid length:";
4242
4243 return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
4244 sizeof(err_str));
4245}
4246
Wei Yongjunaecedea2007-08-02 16:57:44 +08004247/* Handle a protocol violation when the peer trying to advance the
4248 * cumulative tsn ack to a point beyond the max tsn currently sent.
4249 *
4250 * We inform the other end by sending an ABORT with a Protocol Violation
4251 * error code.
4252 */
4253static sctp_disposition_t sctp_sf_violation_ctsn(
4254 const struct sctp_endpoint *ep,
4255 const struct sctp_association *asoc,
4256 const sctp_subtype_t type,
4257 void *arg,
4258 sctp_cmd_seq_t *commands)
4259{
4260 char err_str[]="The cumulative tsn ack beyond the max tsn currently sent:";
4261
Vlad Yasevichece25df2007-09-07 16:30:54 -04004262 return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
Wei Yongjunaecedea2007-08-02 16:57:44 +08004263 sizeof(err_str));
4264}
4265
Vlad Yasevichece25df2007-09-07 16:30:54 -04004266/* Handle protocol violation of an invalid chunk bundling. For example,
4267 * when we have an association and we recieve bundled INIT-ACK, or
4268 * SHUDOWN-COMPLETE, our peer is clearly violationg the "MUST NOT bundle"
4269 * statement from the specs. Additinally, there might be an attacker
4270 * on the path and we may not want to continue this communication.
4271 */
4272static sctp_disposition_t sctp_sf_violation_chunk(
4273 const struct sctp_endpoint *ep,
4274 const struct sctp_association *asoc,
4275 const sctp_subtype_t type,
4276 void *arg,
4277 sctp_cmd_seq_t *commands)
4278{
4279 char err_str[]="The following chunk violates protocol:";
4280
4281 if (!asoc)
4282 return sctp_sf_violation(ep, asoc, type, arg, commands);
4283
4284 return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
4285 sizeof(err_str));
4286}
Linus Torvalds1da177e2005-04-16 15:20:36 -07004287/***************************************************************************
4288 * These are the state functions for handling primitive (Section 10) events.
4289 ***************************************************************************/
4290/*
4291 * sctp_sf_do_prm_asoc
4292 *
4293 * Section: 10.1 ULP-to-SCTP
4294 * B) Associate
4295 *
4296 * Format: ASSOCIATE(local SCTP instance name, destination transport addr,
4297 * outbound stream count)
4298 * -> association id [,destination transport addr list] [,outbound stream
4299 * count]
4300 *
4301 * This primitive allows the upper layer to initiate an association to a
4302 * specific peer endpoint.
4303 *
4304 * The peer endpoint shall be specified by one of the transport addresses
4305 * which defines the endpoint (see Section 1.4). If the local SCTP
4306 * instance has not been initialized, the ASSOCIATE is considered an
4307 * error.
4308 * [This is not relevant for the kernel implementation since we do all
4309 * initialization at boot time. It we hadn't initialized we wouldn't
4310 * get anywhere near this code.]
4311 *
4312 * An association id, which is a local handle to the SCTP association,
4313 * will be returned on successful establishment of the association. If
4314 * SCTP is not able to open an SCTP association with the peer endpoint,
4315 * an error is returned.
4316 * [In the kernel implementation, the struct sctp_association needs to
4317 * be created BEFORE causing this primitive to run.]
4318 *
4319 * Other association parameters may be returned, including the
4320 * complete destination transport addresses of the peer as well as the
4321 * outbound stream count of the local endpoint. One of the transport
4322 * address from the returned destination addresses will be selected by
4323 * the local endpoint as default primary path for sending SCTP packets
4324 * to this peer. The returned "destination transport addr list" can
4325 * be used by the ULP to change the default primary path or to force
4326 * sending a packet to a specific transport address. [All of this
4327 * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING
4328 * function.]
4329 *
4330 * Mandatory attributes:
4331 *
4332 * o local SCTP instance name - obtained from the INITIALIZE operation.
4333 * [This is the argument asoc.]
4334 * o destination transport addr - specified as one of the transport
4335 * addresses of the peer endpoint with which the association is to be
4336 * established.
4337 * [This is asoc->peer.active_path.]
4338 * o outbound stream count - the number of outbound streams the ULP
4339 * would like to open towards this peer endpoint.
4340 * [BUG: This is not currently implemented.]
4341 * Optional attributes:
4342 *
4343 * None.
4344 *
4345 * The return value is a disposition.
4346 */
4347sctp_disposition_t sctp_sf_do_prm_asoc(const struct sctp_endpoint *ep,
4348 const struct sctp_association *asoc,
4349 const sctp_subtype_t type,
4350 void *arg,
4351 sctp_cmd_seq_t *commands)
4352{
4353 struct sctp_chunk *repl;
4354
4355 /* The comment below says that we enter COOKIE-WAIT AFTER
4356 * sending the INIT, but that doesn't actually work in our
4357 * implementation...
4358 */
4359 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4360 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
4361
4362 /* RFC 2960 5.1 Normal Establishment of an Association
4363 *
4364 * A) "A" first sends an INIT chunk to "Z". In the INIT, "A"
4365 * must provide its Verification Tag (Tag_A) in the Initiate
4366 * Tag field. Tag_A SHOULD be a random number in the range of
4367 * 1 to 4294967295 (see 5.3.1 for Tag value selection). ...
4368 */
4369
4370 repl = sctp_make_init(asoc, &asoc->base.bind_addr, GFP_ATOMIC, 0);
4371 if (!repl)
4372 goto nomem;
4373
4374 /* Cast away the const modifier, as we want to just
4375 * rerun it through as a sideffect.
4376 */
4377 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC,
4378 SCTP_ASOC((struct sctp_association *) asoc));
4379
Frank Filz3f7a87d2005-06-20 13:14:57 -07004380 /* Choose transport for INIT. */
4381 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
4382 SCTP_CHUNK(repl));
4383
Linus Torvalds1da177e2005-04-16 15:20:36 -07004384 /* After sending the INIT, "A" starts the T1-init timer and
4385 * enters the COOKIE-WAIT state.
4386 */
4387 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4388 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4389 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
4390 return SCTP_DISPOSITION_CONSUME;
4391
4392nomem:
4393 return SCTP_DISPOSITION_NOMEM;
4394}
4395
4396/*
4397 * Process the SEND primitive.
4398 *
4399 * Section: 10.1 ULP-to-SCTP
4400 * E) Send
4401 *
4402 * Format: SEND(association id, buffer address, byte count [,context]
4403 * [,stream id] [,life time] [,destination transport address]
4404 * [,unorder flag] [,no-bundle flag] [,payload protocol-id] )
4405 * -> result
4406 *
4407 * This is the main method to send user data via SCTP.
4408 *
4409 * Mandatory attributes:
4410 *
4411 * o association id - local handle to the SCTP association
4412 *
4413 * o buffer address - the location where the user message to be
4414 * transmitted is stored;
4415 *
4416 * o byte count - The size of the user data in number of bytes;
4417 *
4418 * Optional attributes:
4419 *
4420 * o context - an optional 32 bit integer that will be carried in the
4421 * sending failure notification to the ULP if the transportation of
4422 * this User Message fails.
4423 *
4424 * o stream id - to indicate which stream to send the data on. If not
4425 * specified, stream 0 will be used.
4426 *
4427 * o life time - specifies the life time of the user data. The user data
4428 * will not be sent by SCTP after the life time expires. This
4429 * parameter can be used to avoid efforts to transmit stale
4430 * user messages. SCTP notifies the ULP if the data cannot be
4431 * initiated to transport (i.e. sent to the destination via SCTP's
4432 * send primitive) within the life time variable. However, the
4433 * user data will be transmitted if SCTP has attempted to transmit a
4434 * chunk before the life time expired.
4435 *
4436 * o destination transport address - specified as one of the destination
4437 * transport addresses of the peer endpoint to which this packet
4438 * should be sent. Whenever possible, SCTP should use this destination
4439 * transport address for sending the packets, instead of the current
4440 * primary path.
4441 *
4442 * o unorder flag - this flag, if present, indicates that the user
4443 * would like the data delivered in an unordered fashion to the peer
4444 * (i.e., the U flag is set to 1 on all DATA chunks carrying this
4445 * message).
4446 *
4447 * o no-bundle flag - instructs SCTP not to bundle this user data with
4448 * other outbound DATA chunks. SCTP MAY still bundle even when
4449 * this flag is present, when faced with network congestion.
4450 *
4451 * o payload protocol-id - A 32 bit unsigned integer that is to be
4452 * passed to the peer indicating the type of payload protocol data
4453 * being transmitted. This value is passed as opaque data by SCTP.
4454 *
4455 * The return value is the disposition.
4456 */
4457sctp_disposition_t sctp_sf_do_prm_send(const struct sctp_endpoint *ep,
4458 const struct sctp_association *asoc,
4459 const sctp_subtype_t type,
4460 void *arg,
4461 sctp_cmd_seq_t *commands)
4462{
4463 struct sctp_chunk *chunk = arg;
4464
4465 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
4466 return SCTP_DISPOSITION_CONSUME;
4467}
4468
4469/*
4470 * Process the SHUTDOWN primitive.
4471 *
4472 * Section: 10.1:
4473 * C) Shutdown
4474 *
4475 * Format: SHUTDOWN(association id)
4476 * -> result
4477 *
4478 * Gracefully closes an association. Any locally queued user data
4479 * will be delivered to the peer. The association will be terminated only
4480 * after the peer acknowledges all the SCTP packets sent. A success code
4481 * will be returned on successful termination of the association. If
4482 * attempting to terminate the association results in a failure, an error
4483 * code shall be returned.
4484 *
4485 * Mandatory attributes:
4486 *
4487 * o association id - local handle to the SCTP association
4488 *
4489 * Optional attributes:
4490 *
4491 * None.
4492 *
4493 * The return value is the disposition.
4494 */
4495sctp_disposition_t sctp_sf_do_9_2_prm_shutdown(
4496 const struct sctp_endpoint *ep,
4497 const struct sctp_association *asoc,
4498 const sctp_subtype_t type,
4499 void *arg,
4500 sctp_cmd_seq_t *commands)
4501{
4502 int disposition;
4503
4504 /* From 9.2 Shutdown of an Association
4505 * Upon receipt of the SHUTDOWN primitive from its upper
4506 * layer, the endpoint enters SHUTDOWN-PENDING state and
4507 * remains there until all outstanding data has been
4508 * acknowledged by its peer. The endpoint accepts no new data
4509 * from its upper layer, but retransmits data to the far end
4510 * if necessary to fill gaps.
4511 */
4512 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4513 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
4514
4515 /* sctpimpguide-05 Section 2.12.2
4516 * The sender of the SHUTDOWN MAY also start an overall guard timer
4517 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
4518 */
4519 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4520 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4521
4522 disposition = SCTP_DISPOSITION_CONSUME;
4523 if (sctp_outq_is_empty(&asoc->outqueue)) {
4524 disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type,
4525 arg, commands);
4526 }
4527 return disposition;
4528}
4529
4530/*
4531 * Process the ABORT primitive.
4532 *
4533 * Section: 10.1:
4534 * C) Abort
4535 *
4536 * Format: Abort(association id [, cause code])
4537 * -> result
4538 *
4539 * Ungracefully closes an association. Any locally queued user data
4540 * will be discarded and an ABORT chunk is sent to the peer. A success code
4541 * will be returned on successful abortion of the association. If
4542 * attempting to abort the association results in a failure, an error
4543 * code shall be returned.
4544 *
4545 * Mandatory attributes:
4546 *
4547 * o association id - local handle to the SCTP association
4548 *
4549 * Optional attributes:
4550 *
4551 * o cause code - reason of the abort to be passed to the peer
4552 *
4553 * None.
4554 *
4555 * The return value is the disposition.
4556 */
4557sctp_disposition_t sctp_sf_do_9_1_prm_abort(
4558 const struct sctp_endpoint *ep,
4559 const struct sctp_association *asoc,
4560 const sctp_subtype_t type,
4561 void *arg,
4562 sctp_cmd_seq_t *commands)
4563{
4564 /* From 9.1 Abort of an Association
4565 * Upon receipt of the ABORT primitive from its upper
4566 * layer, the endpoint enters CLOSED state and
4567 * discard all outstanding data has been
4568 * acknowledged by its peer. The endpoint accepts no new data
4569 * from its upper layer, but retransmits data to the far end
4570 * if necessary to fill gaps.
4571 */
Sridhar Samudralac164a9b2006-08-22 11:50:39 -07004572 struct sctp_chunk *abort = arg;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004573 sctp_disposition_t retval;
4574
4575 retval = SCTP_DISPOSITION_CONSUME;
4576
Sridhar Samudralac164a9b2006-08-22 11:50:39 -07004577 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004578
4579 /* Even if we can't send the ABORT due to low memory delete the
4580 * TCB. This is a departure from our typical NOMEM handling.
4581 */
4582
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004583 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4584 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004585 /* Delete the established association. */
4586 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08004587 SCTP_PERR(SCTP_ERROR_USER_ABORT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004588
4589 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4590 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
4591
4592 return retval;
4593}
4594
4595/* We tried an illegal operation on an association which is closed. */
4596sctp_disposition_t sctp_sf_error_closed(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{
4602 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, SCTP_ERROR(-EINVAL));
4603 return SCTP_DISPOSITION_CONSUME;
4604}
4605
4606/* We tried an illegal operation on an association which is shutting
4607 * down.
4608 */
4609sctp_disposition_t sctp_sf_error_shutdown(const struct sctp_endpoint *ep,
4610 const struct sctp_association *asoc,
4611 const sctp_subtype_t type,
4612 void *arg,
4613 sctp_cmd_seq_t *commands)
4614{
4615 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR,
4616 SCTP_ERROR(-ESHUTDOWN));
4617 return SCTP_DISPOSITION_CONSUME;
4618}
4619
4620/*
4621 * sctp_cookie_wait_prm_shutdown
4622 *
4623 * Section: 4 Note: 2
4624 * Verification Tag:
4625 * Inputs
4626 * (endpoint, asoc)
4627 *
4628 * The RFC does not explicitly address this issue, but is the route through the
4629 * state table when someone issues a shutdown while in COOKIE_WAIT state.
4630 *
4631 * Outputs
4632 * (timers)
4633 */
4634sctp_disposition_t sctp_sf_cookie_wait_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 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4642 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4643
4644 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4645 SCTP_STATE(SCTP_STATE_CLOSED));
4646
4647 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
4648
4649 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
4650
4651 return SCTP_DISPOSITION_DELETE_TCB;
4652}
4653
4654/*
4655 * sctp_cookie_echoed_prm_shutdown
4656 *
4657 * Section: 4 Note: 2
4658 * Verification Tag:
4659 * Inputs
4660 * (endpoint, asoc)
4661 *
4662 * The RFC does not explcitly address this issue, but is the route through the
4663 * state table when someone issues a shutdown while in COOKIE_ECHOED state.
4664 *
4665 * Outputs
4666 * (timers)
4667 */
4668sctp_disposition_t sctp_sf_cookie_echoed_prm_shutdown(
4669 const struct sctp_endpoint *ep,
4670 const struct sctp_association *asoc,
4671 const sctp_subtype_t type,
4672 void *arg, sctp_cmd_seq_t *commands)
4673{
4674 /* There is a single T1 timer, so we should be able to use
4675 * common function with the COOKIE-WAIT state.
4676 */
4677 return sctp_sf_cookie_wait_prm_shutdown(ep, asoc, type, arg, commands);
4678}
4679
4680/*
4681 * sctp_sf_cookie_wait_prm_abort
4682 *
4683 * Section: 4 Note: 2
4684 * Verification Tag:
4685 * Inputs
4686 * (endpoint, asoc)
4687 *
4688 * The RFC does not explicitly address this issue, but is the route through the
4689 * state table when someone issues an abort while in COOKIE_WAIT state.
4690 *
4691 * Outputs
4692 * (timers)
4693 */
4694sctp_disposition_t sctp_sf_cookie_wait_prm_abort(
4695 const struct sctp_endpoint *ep,
4696 const struct sctp_association *asoc,
4697 const sctp_subtype_t type,
4698 void *arg,
4699 sctp_cmd_seq_t *commands)
4700{
Sridhar Samudralac164a9b2006-08-22 11:50:39 -07004701 struct sctp_chunk *abort = arg;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004702 sctp_disposition_t retval;
4703
4704 /* Stop T1-init timer */
4705 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4706 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
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 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4712 SCTP_STATE(SCTP_STATE_CLOSED));
4713
4714 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4715
4716 /* Even if we can't send the ABORT due to low memory delete the
4717 * TCB. This is a departure from our typical NOMEM handling.
4718 */
4719
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004720 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4721 SCTP_ERROR(ECONNREFUSED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004722 /* Delete the established association. */
4723 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08004724 SCTP_PERR(SCTP_ERROR_USER_ABORT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004725
4726 return retval;
4727}
4728
4729/*
4730 * sctp_sf_cookie_echoed_prm_abort
4731 *
4732 * Section: 4 Note: 3
4733 * Verification Tag:
4734 * Inputs
4735 * (endpoint, asoc)
4736 *
4737 * The RFC does not explcitly address this issue, but is the route through the
4738 * state table when someone issues an abort while in COOKIE_ECHOED state.
4739 *
4740 * Outputs
4741 * (timers)
4742 */
4743sctp_disposition_t sctp_sf_cookie_echoed_prm_abort(
4744 const struct sctp_endpoint *ep,
4745 const struct sctp_association *asoc,
4746 const sctp_subtype_t type,
4747 void *arg,
4748 sctp_cmd_seq_t *commands)
4749{
4750 /* There is a single T1 timer, so we should be able to use
4751 * common function with the COOKIE-WAIT state.
4752 */
4753 return sctp_sf_cookie_wait_prm_abort(ep, asoc, type, arg, commands);
4754}
4755
4756/*
4757 * sctp_sf_shutdown_pending_prm_abort
4758 *
4759 * Inputs
4760 * (endpoint, asoc)
4761 *
4762 * The RFC does not explicitly address this issue, but is the route through the
4763 * state table when someone issues an abort while in SHUTDOWN-PENDING state.
4764 *
4765 * Outputs
4766 * (timers)
4767 */
4768sctp_disposition_t sctp_sf_shutdown_pending_prm_abort(
4769 const struct sctp_endpoint *ep,
4770 const struct sctp_association *asoc,
4771 const sctp_subtype_t type,
4772 void *arg,
4773 sctp_cmd_seq_t *commands)
4774{
4775 /* Stop the T5-shutdown guard timer. */
4776 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4777 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4778
4779 return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands);
4780}
4781
4782/*
4783 * sctp_sf_shutdown_sent_prm_abort
4784 *
4785 * Inputs
4786 * (endpoint, asoc)
4787 *
4788 * The RFC does not explicitly address this issue, but is the route through the
4789 * state table when someone issues an abort while in SHUTDOWN-SENT state.
4790 *
4791 * Outputs
4792 * (timers)
4793 */
4794sctp_disposition_t sctp_sf_shutdown_sent_prm_abort(
4795 const struct sctp_endpoint *ep,
4796 const struct sctp_association *asoc,
4797 const sctp_subtype_t type,
4798 void *arg,
4799 sctp_cmd_seq_t *commands)
4800{
4801 /* Stop the T2-shutdown timer. */
4802 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4803 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4804
4805 /* Stop the T5-shutdown guard timer. */
4806 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4807 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4808
4809 return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands);
4810}
4811
4812/*
4813 * sctp_sf_cookie_echoed_prm_abort
4814 *
4815 * Inputs
4816 * (endpoint, asoc)
4817 *
4818 * The RFC does not explcitly address this issue, but is the route through the
4819 * state table when someone issues an abort while in COOKIE_ECHOED state.
4820 *
4821 * Outputs
4822 * (timers)
4823 */
4824sctp_disposition_t sctp_sf_shutdown_ack_sent_prm_abort(
4825 const struct sctp_endpoint *ep,
4826 const struct sctp_association *asoc,
4827 const sctp_subtype_t type,
4828 void *arg,
4829 sctp_cmd_seq_t *commands)
4830{
4831 /* The same T2 timer, so we should be able to use
4832 * common function with the SHUTDOWN-SENT state.
4833 */
4834 return sctp_sf_shutdown_sent_prm_abort(ep, asoc, type, arg, commands);
4835}
4836
4837/*
4838 * Process the REQUESTHEARTBEAT primitive
4839 *
4840 * 10.1 ULP-to-SCTP
4841 * J) Request Heartbeat
4842 *
4843 * Format: REQUESTHEARTBEAT(association id, destination transport address)
4844 *
4845 * -> result
4846 *
4847 * Instructs the local endpoint to perform a HeartBeat on the specified
4848 * destination transport address of the given association. The returned
4849 * result should indicate whether the transmission of the HEARTBEAT
4850 * chunk to the destination address is successful.
4851 *
4852 * Mandatory attributes:
4853 *
4854 * o association id - local handle to the SCTP association
4855 *
4856 * o destination transport address - the transport address of the
4857 * association on which a heartbeat should be issued.
4858 */
4859sctp_disposition_t sctp_sf_do_prm_requestheartbeat(
4860 const struct sctp_endpoint *ep,
4861 const struct sctp_association *asoc,
4862 const sctp_subtype_t type,
4863 void *arg,
4864 sctp_cmd_seq_t *commands)
4865{
Vlad Yasevichfb785252007-03-19 17:02:03 -07004866 if (SCTP_DISPOSITION_NOMEM == sctp_sf_heartbeat(ep, asoc, type,
4867 (struct sctp_transport *)arg, commands))
4868 return SCTP_DISPOSITION_NOMEM;
4869
4870 /*
4871 * RFC 2960 (bis), section 8.3
4872 *
4873 * D) Request an on-demand HEARTBEAT on a specific destination
4874 * transport address of a given association.
4875 *
4876 * The endpoint should increment the respective error counter of
4877 * the destination transport address each time a HEARTBEAT is sent
4878 * to that address and not acknowledged within one RTO.
4879 *
4880 */
4881 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_RESET,
4882 SCTP_TRANSPORT(arg));
4883 return SCTP_DISPOSITION_CONSUME;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004884}
4885
4886/*
4887 * ADDIP Section 4.1 ASCONF Chunk Procedures
4888 * When an endpoint has an ASCONF signaled change to be sent to the
4889 * remote endpoint it should do A1 to A9
4890 */
4891sctp_disposition_t sctp_sf_do_prm_asconf(const struct sctp_endpoint *ep,
4892 const struct sctp_association *asoc,
4893 const sctp_subtype_t type,
4894 void *arg,
4895 sctp_cmd_seq_t *commands)
4896{
4897 struct sctp_chunk *chunk = arg;
4898
4899 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
4900 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4901 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
4902 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
4903 return SCTP_DISPOSITION_CONSUME;
4904}
4905
4906/*
4907 * Ignore the primitive event
4908 *
4909 * The return value is the disposition of the primitive.
4910 */
4911sctp_disposition_t sctp_sf_ignore_primitive(
4912 const struct sctp_endpoint *ep,
4913 const struct sctp_association *asoc,
4914 const sctp_subtype_t type,
4915 void *arg,
4916 sctp_cmd_seq_t *commands)
4917{
4918 SCTP_DEBUG_PRINTK("Primitive type %d is ignored.\n", type.primitive);
4919 return SCTP_DISPOSITION_DISCARD;
4920}
4921
4922/***************************************************************************
4923 * These are the state functions for the OTHER events.
4924 ***************************************************************************/
4925
4926/*
4927 * Start the shutdown negotiation.
4928 *
4929 * From Section 9.2:
4930 * Once all its outstanding data has been acknowledged, the endpoint
4931 * shall send a SHUTDOWN chunk to its peer including in the Cumulative
4932 * TSN Ack field the last sequential TSN it has received from the peer.
4933 * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT
4934 * state. If the timer expires, the endpoint must re-send the SHUTDOWN
4935 * with the updated last sequential TSN received from its peer.
4936 *
4937 * The return value is the disposition.
4938 */
4939sctp_disposition_t sctp_sf_do_9_2_start_shutdown(
4940 const struct sctp_endpoint *ep,
4941 const struct sctp_association *asoc,
4942 const sctp_subtype_t type,
4943 void *arg,
4944 sctp_cmd_seq_t *commands)
4945{
4946 struct sctp_chunk *reply;
4947
4948 /* Once all its outstanding data has been acknowledged, the
4949 * endpoint shall send a SHUTDOWN chunk to its peer including
4950 * in the Cumulative TSN Ack field the last sequential TSN it
4951 * has received from the peer.
4952 */
4953 reply = sctp_make_shutdown(asoc, NULL);
4954 if (!reply)
4955 goto nomem;
4956
4957 /* Set the transport for the SHUTDOWN chunk and the timeout for the
4958 * T2-shutdown timer.
4959 */
4960 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
4961
4962 /* It shall then start the T2-shutdown timer */
4963 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4964 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4965
4966 if (asoc->autoclose)
4967 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4968 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
4969
4970 /* and enter the SHUTDOWN-SENT state. */
4971 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4972 SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT));
4973
4974 /* sctp-implguide 2.10 Issues with Heartbeating and failover
4975 *
4976 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09004977 * or SHUTDOWN-ACK.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004978 */
4979 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
4980
4981 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
4982
4983 return SCTP_DISPOSITION_CONSUME;
4984
4985nomem:
4986 return SCTP_DISPOSITION_NOMEM;
4987}
4988
4989/*
4990 * Generate a SHUTDOWN ACK now that everything is SACK'd.
4991 *
4992 * From Section 9.2:
4993 *
4994 * If it has no more outstanding DATA chunks, the SHUTDOWN receiver
4995 * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own,
4996 * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the
4997 * endpoint must re-send the SHUTDOWN ACK.
4998 *
4999 * The return value is the disposition.
5000 */
5001sctp_disposition_t sctp_sf_do_9_2_shutdown_ack(
5002 const struct sctp_endpoint *ep,
5003 const struct sctp_association *asoc,
5004 const sctp_subtype_t type,
5005 void *arg,
5006 sctp_cmd_seq_t *commands)
5007{
5008 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
5009 struct sctp_chunk *reply;
5010
5011 /* There are 2 ways of getting here:
5012 * 1) called in response to a SHUTDOWN chunk
5013 * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued.
5014 *
5015 * For the case (2), the arg parameter is set to NULL. We need
5016 * to check that we have a chunk before accessing it's fields.
5017 */
5018 if (chunk) {
5019 if (!sctp_vtag_verify(chunk, asoc))
5020 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
5021
5022 /* Make sure that the SHUTDOWN chunk has a valid length. */
5023 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_shutdown_chunk_t)))
5024 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
5025 commands);
5026 }
5027
5028 /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5029 * shall send a SHUTDOWN ACK ...
5030 */
5031 reply = sctp_make_shutdown_ack(asoc, chunk);
5032 if (!reply)
5033 goto nomem;
5034
5035 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
5036 * the T2-shutdown timer.
5037 */
5038 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5039
5040 /* and start/restart a T2-shutdown timer of its own, */
5041 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5042 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5043
5044 if (asoc->autoclose)
5045 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5046 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
5047
5048 /* Enter the SHUTDOWN-ACK-SENT state. */
5049 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5050 SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT));
5051
5052 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5053 *
5054 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09005055 * or SHUTDOWN-ACK.
Linus Torvalds1da177e2005-04-16 15:20:36 -07005056 */
5057 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
5058
5059 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5060
5061 return SCTP_DISPOSITION_CONSUME;
5062
5063nomem:
5064 return SCTP_DISPOSITION_NOMEM;
5065}
5066
5067/*
5068 * Ignore the event defined as other
5069 *
5070 * The return value is the disposition of the event.
5071 */
5072sctp_disposition_t sctp_sf_ignore_other(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 SCTP_DEBUG_PRINTK("The event other type %d is ignored\n", type.other);
5079 return SCTP_DISPOSITION_DISCARD;
5080}
5081
5082/************************************************************
5083 * These are the state functions for handling timeout events.
5084 ************************************************************/
5085
5086/*
5087 * RTX Timeout
5088 *
5089 * Section: 6.3.3 Handle T3-rtx Expiration
5090 *
5091 * Whenever the retransmission timer T3-rtx expires for a destination
5092 * address, do the following:
5093 * [See below]
5094 *
5095 * The return value is the disposition of the chunk.
5096 */
5097sctp_disposition_t sctp_sf_do_6_3_3_rtx(const struct sctp_endpoint *ep,
5098 const struct sctp_association *asoc,
5099 const sctp_subtype_t type,
5100 void *arg,
5101 sctp_cmd_seq_t *commands)
5102{
5103 struct sctp_transport *transport = arg;
5104
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07005105 SCTP_INC_STATS(SCTP_MIB_T3_RTX_EXPIREDS);
5106
Linus Torvalds1da177e2005-04-16 15:20:36 -07005107 if (asoc->overall_error_count >= asoc->max_retrans) {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07005108 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5109 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005110 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5111 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08005112 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005113 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
5114 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
5115 return SCTP_DISPOSITION_DELETE_TCB;
5116 }
5117
5118 /* E1) For the destination address for which the timer
5119 * expires, adjust its ssthresh with rules defined in Section
5120 * 7.2.3 and set the cwnd <- MTU.
5121 */
5122
5123 /* E2) For the destination address for which the timer
5124 * expires, set RTO <- RTO * 2 ("back off the timer"). The
5125 * maximum value discussed in rule C7 above (RTO.max) may be
5126 * used to provide an upper bound to this doubling operation.
5127 */
5128
5129 /* E3) Determine how many of the earliest (i.e., lowest TSN)
5130 * outstanding DATA chunks for the address for which the
5131 * T3-rtx has expired will fit into a single packet, subject
5132 * to the MTU constraint for the path corresponding to the
5133 * destination transport address to which the retransmission
5134 * is being sent (this may be different from the address for
5135 * which the timer expires [see Section 6.4]). Call this
5136 * value K. Bundle and retransmit those K DATA chunks in a
5137 * single packet to the destination endpoint.
5138 *
5139 * Note: Any DATA chunks that were sent to the address for
5140 * which the T3-rtx timer expired but did not fit in one MTU
5141 * (rule E3 above), should be marked for retransmission and
5142 * sent as soon as cwnd allows (normally when a SACK arrives).
5143 */
5144
Linus Torvalds1da177e2005-04-16 15:20:36 -07005145 /* Do some failure management (Section 8.2). */
5146 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
5147
Vlad Yasevich1845a572007-02-21 02:06:19 -08005148 /* NB: Rules E4 and F1 are implicit in R1. */
5149 sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN, SCTP_TRANSPORT(transport));
5150
Linus Torvalds1da177e2005-04-16 15:20:36 -07005151 return SCTP_DISPOSITION_CONSUME;
5152}
5153
5154/*
5155 * Generate delayed SACK on timeout
5156 *
5157 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
5158 *
5159 * The guidelines on delayed acknowledgement algorithm specified in
5160 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
5161 * acknowledgement SHOULD be generated for at least every second packet
5162 * (not every second DATA chunk) received, and SHOULD be generated
5163 * within 200 ms of the arrival of any unacknowledged DATA chunk. In
5164 * some situations it may be beneficial for an SCTP transmitter to be
5165 * more conservative than the algorithms detailed in this document
5166 * allow. However, an SCTP transmitter MUST NOT be more aggressive than
5167 * the following algorithms allow.
5168 */
5169sctp_disposition_t sctp_sf_do_6_2_sack(const struct sctp_endpoint *ep,
5170 const struct sctp_association *asoc,
5171 const sctp_subtype_t type,
5172 void *arg,
5173 sctp_cmd_seq_t *commands)
5174{
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07005175 SCTP_INC_STATS(SCTP_MIB_DELAY_SACK_EXPIREDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005176 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
5177 return SCTP_DISPOSITION_CONSUME;
5178}
5179
5180/*
Frank Filz3f7a87d2005-06-20 13:14:57 -07005181 * sctp_sf_t1_init_timer_expire
Linus Torvalds1da177e2005-04-16 15:20:36 -07005182 *
5183 * Section: 4 Note: 2
5184 * Verification Tag:
5185 * Inputs
5186 * (endpoint, asoc)
5187 *
5188 * RFC 2960 Section 4 Notes
5189 * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT
5190 * and re-start the T1-init timer without changing state. This MUST
5191 * be repeated up to 'Max.Init.Retransmits' times. After that, the
5192 * endpoint MUST abort the initialization process and report the
5193 * error to SCTP user.
5194 *
Frank Filz3f7a87d2005-06-20 13:14:57 -07005195 * Outputs
5196 * (timers, events)
5197 *
5198 */
5199sctp_disposition_t sctp_sf_t1_init_timer_expire(const struct sctp_endpoint *ep,
5200 const struct sctp_association *asoc,
5201 const sctp_subtype_t type,
5202 void *arg,
5203 sctp_cmd_seq_t *commands)
5204{
5205 struct sctp_chunk *repl = NULL;
5206 struct sctp_bind_addr *bp;
5207 int attempts = asoc->init_err_counter + 1;
5208
5209 SCTP_DEBUG_PRINTK("Timer T1 expired (INIT).\n");
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07005210 SCTP_INC_STATS(SCTP_MIB_T1_INIT_EXPIREDS);
Frank Filz3f7a87d2005-06-20 13:14:57 -07005211
Vlad Yasevich81845c22006-01-30 15:59:54 -08005212 if (attempts <= asoc->max_init_attempts) {
Frank Filz3f7a87d2005-06-20 13:14:57 -07005213 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
5214 repl = sctp_make_init(asoc, bp, GFP_ATOMIC, 0);
5215 if (!repl)
5216 return SCTP_DISPOSITION_NOMEM;
5217
5218 /* Choose transport for INIT. */
5219 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
5220 SCTP_CHUNK(repl));
5221
5222 /* Issue a sideeffect to do the needed accounting. */
5223 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_RESTART,
5224 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
5225
5226 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
5227 } else {
5228 SCTP_DEBUG_PRINTK("Giving up on INIT, attempts: %d"
5229 " max_init_attempts: %d\n",
5230 attempts, asoc->max_init_attempts);
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07005231 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5232 SCTP_ERROR(ETIMEDOUT));
Frank Filz3f7a87d2005-06-20 13:14:57 -07005233 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08005234 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Frank Filz3f7a87d2005-06-20 13:14:57 -07005235 return SCTP_DISPOSITION_DELETE_TCB;
5236 }
5237
5238 return SCTP_DISPOSITION_CONSUME;
5239}
5240
5241/*
5242 * sctp_sf_t1_cookie_timer_expire
5243 *
5244 * Section: 4 Note: 2
5245 * Verification Tag:
5246 * Inputs
5247 * (endpoint, asoc)
5248 *
5249 * RFC 2960 Section 4 Notes
5250 * 3) If the T1-cookie timer expires, the endpoint MUST retransmit
Linus Torvalds1da177e2005-04-16 15:20:36 -07005251 * COOKIE ECHO and re-start the T1-cookie timer without changing
5252 * state. This MUST be repeated up to 'Max.Init.Retransmits' times.
5253 * After that, the endpoint MUST abort the initialization process and
5254 * report the error to SCTP user.
5255 *
5256 * Outputs
5257 * (timers, events)
5258 *
5259 */
Frank Filz3f7a87d2005-06-20 13:14:57 -07005260sctp_disposition_t sctp_sf_t1_cookie_timer_expire(const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005261 const struct sctp_association *asoc,
5262 const sctp_subtype_t type,
5263 void *arg,
5264 sctp_cmd_seq_t *commands)
5265{
Frank Filz3f7a87d2005-06-20 13:14:57 -07005266 struct sctp_chunk *repl = NULL;
5267 int attempts = asoc->init_err_counter + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005268
Frank Filz3f7a87d2005-06-20 13:14:57 -07005269 SCTP_DEBUG_PRINTK("Timer T1 expired (COOKIE-ECHO).\n");
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07005270 SCTP_INC_STATS(SCTP_MIB_T1_COOKIE_EXPIREDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005271
Vlad Yasevich81845c22006-01-30 15:59:54 -08005272 if (attempts <= asoc->max_init_attempts) {
Frank Filz3f7a87d2005-06-20 13:14:57 -07005273 repl = sctp_make_cookie_echo(asoc, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005274 if (!repl)
Frank Filz3f7a87d2005-06-20 13:14:57 -07005275 return SCTP_DISPOSITION_NOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005276
5277 /* Issue a sideeffect to do the needed accounting. */
Frank Filz3f7a87d2005-06-20 13:14:57 -07005278 sctp_add_cmd_sf(commands, SCTP_CMD_COOKIEECHO_RESTART,
5279 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
5280
Linus Torvalds1da177e2005-04-16 15:20:36 -07005281 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
5282 } else {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07005283 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5284 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005285 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08005286 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005287 return SCTP_DISPOSITION_DELETE_TCB;
5288 }
5289
5290 return SCTP_DISPOSITION_CONSUME;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005291}
5292
5293/* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN
5294 * with the updated last sequential TSN received from its peer.
5295 *
5296 * An endpoint should limit the number of retransmissions of the
5297 * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'.
5298 * If this threshold is exceeded the endpoint should destroy the TCB and
5299 * MUST report the peer endpoint unreachable to the upper layer (and
5300 * thus the association enters the CLOSED state). The reception of any
5301 * packet from its peer (i.e. as the peer sends all of its queued DATA
5302 * chunks) should clear the endpoint's retransmission count and restart
5303 * the T2-Shutdown timer, giving its peer ample opportunity to transmit
5304 * all of its queued DATA chunks that have not yet been sent.
5305 */
5306sctp_disposition_t sctp_sf_t2_timer_expire(const struct sctp_endpoint *ep,
5307 const struct sctp_association *asoc,
5308 const sctp_subtype_t type,
5309 void *arg,
5310 sctp_cmd_seq_t *commands)
5311{
5312 struct sctp_chunk *reply = NULL;
5313
5314 SCTP_DEBUG_PRINTK("Timer T2 expired.\n");
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07005315 SCTP_INC_STATS(SCTP_MIB_T2_SHUTDOWN_EXPIREDS);
5316
Linus Torvalds1da177e2005-04-16 15:20:36 -07005317 if (asoc->overall_error_count >= asoc->max_retrans) {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07005318 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5319 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005320 /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5321 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08005322 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005323 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
5324 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
5325 return SCTP_DISPOSITION_DELETE_TCB;
5326 }
5327
5328 switch (asoc->state) {
5329 case SCTP_STATE_SHUTDOWN_SENT:
5330 reply = sctp_make_shutdown(asoc, NULL);
5331 break;
5332
5333 case SCTP_STATE_SHUTDOWN_ACK_SENT:
5334 reply = sctp_make_shutdown_ack(asoc, NULL);
5335 break;
5336
5337 default:
5338 BUG();
5339 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07005340 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07005341
5342 if (!reply)
5343 goto nomem;
5344
5345 /* Do some failure management (Section 8.2). */
5346 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
5347 SCTP_TRANSPORT(asoc->shutdown_last_sent_to));
5348
5349 /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for
5350 * the T2-shutdown timer.
5351 */
5352 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5353
5354 /* Restart the T2-shutdown timer. */
5355 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5356 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5357 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5358 return SCTP_DISPOSITION_CONSUME;
5359
5360nomem:
5361 return SCTP_DISPOSITION_NOMEM;
5362}
5363
5364/*
5365 * ADDIP Section 4.1 ASCONF CHunk Procedures
5366 * If the T4 RTO timer expires the endpoint should do B1 to B5
5367 */
5368sctp_disposition_t sctp_sf_t4_timer_expire(
5369 const struct sctp_endpoint *ep,
5370 const struct sctp_association *asoc,
5371 const sctp_subtype_t type,
5372 void *arg,
5373 sctp_cmd_seq_t *commands)
5374{
5375 struct sctp_chunk *chunk = asoc->addip_last_asconf;
5376 struct sctp_transport *transport = chunk->transport;
5377
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07005378 SCTP_INC_STATS(SCTP_MIB_T4_RTO_EXPIREDS);
5379
Linus Torvalds1da177e2005-04-16 15:20:36 -07005380 /* ADDIP 4.1 B1) Increment the error counters and perform path failure
5381 * detection on the appropriate destination address as defined in
5382 * RFC2960 [5] section 8.1 and 8.2.
5383 */
5384 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
5385
5386 /* Reconfig T4 timer and transport. */
5387 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
5388
5389 /* ADDIP 4.1 B2) Increment the association error counters and perform
5390 * endpoint failure detection on the association as defined in
5391 * RFC2960 [5] section 8.1 and 8.2.
5392 * association error counter is incremented in SCTP_CMD_STRIKE.
5393 */
5394 if (asoc->overall_error_count >= asoc->max_retrans) {
5395 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5396 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07005397 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5398 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005399 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08005400 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005401 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
5402 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
5403 return SCTP_DISPOSITION_ABORT;
5404 }
5405
5406 /* ADDIP 4.1 B3) Back-off the destination address RTO value to which
5407 * the ASCONF chunk was sent by doubling the RTO timer value.
5408 * This is done in SCTP_CMD_STRIKE.
5409 */
5410
5411 /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible
5412 * choose an alternate destination address (please refer to RFC2960
5413 * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09005414 * chunk, it MUST be the same (including its serial number) as the last
Linus Torvalds1da177e2005-04-16 15:20:36 -07005415 * ASCONF sent.
5416 */
5417 sctp_chunk_hold(asoc->addip_last_asconf);
5418 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
5419 SCTP_CHUNK(asoc->addip_last_asconf));
5420
5421 /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different
5422 * destination is selected, then the RTO used will be that of the new
5423 * destination address.
5424 */
5425 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5426 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
5427
5428 return SCTP_DISPOSITION_CONSUME;
5429}
5430
5431/* sctpimpguide-05 Section 2.12.2
5432 * The sender of the SHUTDOWN MAY also start an overall guard timer
5433 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5434 * At the expiration of this timer the sender SHOULD abort the association
5435 * by sending an ABORT chunk.
5436 */
5437sctp_disposition_t sctp_sf_t5_timer_expire(const struct sctp_endpoint *ep,
5438 const struct sctp_association *asoc,
5439 const sctp_subtype_t type,
5440 void *arg,
5441 sctp_cmd_seq_t *commands)
5442{
5443 struct sctp_chunk *reply = NULL;
5444
5445 SCTP_DEBUG_PRINTK("Timer T5 expired.\n");
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07005446 SCTP_INC_STATS(SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005447
5448 reply = sctp_make_abort(asoc, NULL, 0);
5449 if (!reply)
5450 goto nomem;
5451
5452 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07005453 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5454 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005455 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08005456 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005457
5458 return SCTP_DISPOSITION_DELETE_TCB;
5459nomem:
5460 return SCTP_DISPOSITION_NOMEM;
5461}
5462
5463/* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires,
5464 * the association is automatically closed by starting the shutdown process.
5465 * The work that needs to be done is same as when SHUTDOWN is initiated by
5466 * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown().
5467 */
5468sctp_disposition_t sctp_sf_autoclose_timer_expire(
5469 const struct sctp_endpoint *ep,
5470 const struct sctp_association *asoc,
5471 const sctp_subtype_t type,
5472 void *arg,
5473 sctp_cmd_seq_t *commands)
5474{
5475 int disposition;
5476
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07005477 SCTP_INC_STATS(SCTP_MIB_AUTOCLOSE_EXPIREDS);
5478
Linus Torvalds1da177e2005-04-16 15:20:36 -07005479 /* From 9.2 Shutdown of an Association
5480 * Upon receipt of the SHUTDOWN primitive from its upper
5481 * layer, the endpoint enters SHUTDOWN-PENDING state and
5482 * remains there until all outstanding data has been
5483 * acknowledged by its peer. The endpoint accepts no new data
5484 * from its upper layer, but retransmits data to the far end
5485 * if necessary to fill gaps.
5486 */
5487 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5488 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
5489
5490 /* sctpimpguide-05 Section 2.12.2
5491 * The sender of the SHUTDOWN MAY also start an overall guard timer
5492 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09005493 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07005494 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
5495 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5496 disposition = SCTP_DISPOSITION_CONSUME;
5497 if (sctp_outq_is_empty(&asoc->outqueue)) {
5498 disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type,
5499 arg, commands);
5500 }
5501 return disposition;
5502}
5503
5504/*****************************************************************************
5505 * These are sa state functions which could apply to all types of events.
5506 ****************************************************************************/
5507
5508/*
5509 * This table entry is not implemented.
5510 *
5511 * Inputs
5512 * (endpoint, asoc, chunk)
5513 *
5514 * The return value is the disposition of the chunk.
5515 */
5516sctp_disposition_t sctp_sf_not_impl(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 return SCTP_DISPOSITION_NOT_IMPL;
5523}
5524
5525/*
5526 * This table entry represents a bug.
5527 *
5528 * Inputs
5529 * (endpoint, asoc, chunk)
5530 *
5531 * The return value is the disposition of the chunk.
5532 */
5533sctp_disposition_t sctp_sf_bug(const struct sctp_endpoint *ep,
5534 const struct sctp_association *asoc,
5535 const sctp_subtype_t type,
5536 void *arg,
5537 sctp_cmd_seq_t *commands)
5538{
5539 return SCTP_DISPOSITION_BUG;
5540}
5541
5542/*
5543 * This table entry represents the firing of a timer in the wrong state.
5544 * Since timer deletion cannot be guaranteed a timer 'may' end up firing
5545 * when the association is in the wrong state. This event should
5546 * be ignored, so as to prevent any rearming of the timer.
5547 *
5548 * Inputs
5549 * (endpoint, asoc, chunk)
5550 *
5551 * The return value is the disposition of the chunk.
5552 */
5553sctp_disposition_t sctp_sf_timer_ignore(const struct sctp_endpoint *ep,
5554 const struct sctp_association *asoc,
5555 const sctp_subtype_t type,
5556 void *arg,
5557 sctp_cmd_seq_t *commands)
5558{
5559 SCTP_DEBUG_PRINTK("Timer %d ignored.\n", type.chunk);
5560 return SCTP_DISPOSITION_CONSUME;
5561}
5562
5563/********************************************************************
5564 * 2nd Level Abstractions
5565 ********************************************************************/
5566
5567/* Pull the SACK chunk based on the SACK header. */
5568static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk)
5569{
5570 struct sctp_sackhdr *sack;
5571 unsigned int len;
5572 __u16 num_blocks;
5573 __u16 num_dup_tsns;
5574
5575 /* Protect ourselves from reading too far into
5576 * the skb from a bogus sender.
5577 */
5578 sack = (struct sctp_sackhdr *) chunk->skb->data;
5579
5580 num_blocks = ntohs(sack->num_gap_ack_blocks);
5581 num_dup_tsns = ntohs(sack->num_dup_tsns);
5582 len = sizeof(struct sctp_sackhdr);
5583 len += (num_blocks + num_dup_tsns) * sizeof(__u32);
5584 if (len > chunk->skb->len)
5585 return NULL;
5586
5587 skb_pull(chunk->skb, len);
5588
5589 return sack;
5590}
5591
5592/* Create an ABORT packet to be sent as a response, with the specified
5593 * error causes.
5594 */
5595static struct sctp_packet *sctp_abort_pkt_new(const struct sctp_endpoint *ep,
5596 const struct sctp_association *asoc,
5597 struct sctp_chunk *chunk,
5598 const void *payload,
5599 size_t paylen)
5600{
5601 struct sctp_packet *packet;
5602 struct sctp_chunk *abort;
5603
5604 packet = sctp_ootb_pkt_new(asoc, chunk);
5605
5606 if (packet) {
5607 /* Make an ABORT.
5608 * The T bit will be set if the asoc is NULL.
5609 */
5610 abort = sctp_make_abort(asoc, chunk, paylen);
5611 if (!abort) {
5612 sctp_ootb_pkt_free(packet);
5613 return NULL;
5614 }
Jerome Forissier047a2422005-04-28 11:58:43 -07005615
5616 /* Reflect vtag if T-Bit is set */
5617 if (sctp_test_T_bit(abort))
5618 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
5619
Linus Torvalds1da177e2005-04-16 15:20:36 -07005620 /* Add specified error causes, i.e., payload, to the
5621 * end of the chunk.
5622 */
5623 sctp_addto_chunk(abort, paylen, payload);
5624
5625 /* Set the skb to the belonging sock for accounting. */
5626 abort->skb->sk = ep->base.sk;
5627
5628 sctp_packet_append_chunk(packet, abort);
5629
5630 }
5631
5632 return packet;
5633}
5634
5635/* Allocate a packet for responding in the OOTB conditions. */
5636static struct sctp_packet *sctp_ootb_pkt_new(const struct sctp_association *asoc,
5637 const struct sctp_chunk *chunk)
5638{
5639 struct sctp_packet *packet;
5640 struct sctp_transport *transport;
5641 __u16 sport;
5642 __u16 dport;
5643 __u32 vtag;
5644
5645 /* Get the source and destination port from the inbound packet. */
5646 sport = ntohs(chunk->sctp_hdr->dest);
5647 dport = ntohs(chunk->sctp_hdr->source);
5648
5649 /* The V-tag is going to be the same as the inbound packet if no
5650 * association exists, otherwise, use the peer's vtag.
5651 */
5652 if (asoc) {
Wei Yongjun02c4e122007-08-31 10:03:58 +08005653 /* Special case the INIT-ACK as there is no peer's vtag
5654 * yet.
5655 */
5656 switch(chunk->chunk_hdr->type) {
5657 case SCTP_CID_INIT_ACK:
5658 {
5659 sctp_initack_chunk_t *initack;
5660
5661 initack = (sctp_initack_chunk_t *)chunk->chunk_hdr;
5662 vtag = ntohl(initack->init_hdr.init_tag);
5663 break;
5664 }
5665 default:
5666 vtag = asoc->peer.i.init_tag;
5667 break;
5668 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07005669 } else {
5670 /* Special case the INIT and stale COOKIE_ECHO as there is no
5671 * vtag yet.
5672 */
5673 switch(chunk->chunk_hdr->type) {
5674 case SCTP_CID_INIT:
5675 {
5676 sctp_init_chunk_t *init;
5677
5678 init = (sctp_init_chunk_t *)chunk->chunk_hdr;
5679 vtag = ntohl(init->init_hdr.init_tag);
5680 break;
5681 }
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09005682 default:
Linus Torvalds1da177e2005-04-16 15:20:36 -07005683 vtag = ntohl(chunk->sctp_hdr->vtag);
5684 break;
5685 }
5686 }
5687
5688 /* Make a transport for the bucket, Eliza... */
Al Viro6a1e5f32006-11-20 17:12:25 -08005689 transport = sctp_transport_new(sctp_source(chunk), GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005690 if (!transport)
5691 goto nomem;
5692
5693 /* Cache a route for the transport with the chunk's destination as
5694 * the source address.
5695 */
Al Viro16b0a032006-11-20 17:13:38 -08005696 sctp_transport_route(transport, (union sctp_addr *)&chunk->dest,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005697 sctp_sk(sctp_get_ctl_sock()));
5698
5699 packet = sctp_packet_init(&transport->packet, transport, sport, dport);
5700 packet = sctp_packet_config(packet, vtag, 0);
5701
5702 return packet;
5703
5704nomem:
5705 return NULL;
5706}
5707
5708/* Free the packet allocated earlier for responding in the OOTB condition. */
5709void sctp_ootb_pkt_free(struct sctp_packet *packet)
5710{
5711 sctp_transport_free(packet->transport);
5712}
5713
5714/* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */
5715static void sctp_send_stale_cookie_err(const struct sctp_endpoint *ep,
5716 const struct sctp_association *asoc,
5717 const struct sctp_chunk *chunk,
5718 sctp_cmd_seq_t *commands,
5719 struct sctp_chunk *err_chunk)
5720{
5721 struct sctp_packet *packet;
5722
5723 if (err_chunk) {
5724 packet = sctp_ootb_pkt_new(asoc, chunk);
5725 if (packet) {
5726 struct sctp_signed_cookie *cookie;
5727
5728 /* Override the OOTB vtag from the cookie. */
5729 cookie = chunk->subh.cookie_hdr;
5730 packet->vtag = cookie->c.peer_vtag;
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09005731
Linus Torvalds1da177e2005-04-16 15:20:36 -07005732 /* Set the skb to the belonging sock for accounting. */
5733 err_chunk->skb->sk = ep->base.sk;
5734 sctp_packet_append_chunk(packet, err_chunk);
5735 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
5736 SCTP_PACKET(packet));
5737 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
5738 } else
5739 sctp_chunk_free (err_chunk);
5740 }
5741}
5742
5743
5744/* Process a data chunk */
5745static int sctp_eat_data(const struct sctp_association *asoc,
5746 struct sctp_chunk *chunk,
5747 sctp_cmd_seq_t *commands)
5748{
5749 sctp_datahdr_t *data_hdr;
5750 struct sctp_chunk *err;
5751 size_t datalen;
5752 sctp_verb_t deliver;
5753 int tmp;
5754 __u32 tsn;
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005755 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
Neil Horman049b3ff2005-11-11 16:08:24 -08005756 struct sock *sk = asoc->base.sk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005757
5758 data_hdr = chunk->subh.data_hdr = (sctp_datahdr_t *)chunk->skb->data;
5759 skb_pull(chunk->skb, sizeof(sctp_datahdr_t));
5760
5761 tsn = ntohl(data_hdr->tsn);
5762 SCTP_DEBUG_PRINTK("eat_data: TSN 0x%x.\n", tsn);
5763
5764 /* ASSERT: Now skb->data is really the user data. */
5765
Linus Torvalds1da177e2005-04-16 15:20:36 -07005766 /* Process ECN based congestion.
5767 *
5768 * Since the chunk structure is reused for all chunks within
5769 * a packet, we use ecn_ce_done to track if we've already
5770 * done CE processing for this packet.
5771 *
5772 * We need to do ECN processing even if we plan to discard the
5773 * chunk later.
5774 */
5775
5776 if (!chunk->ecn_ce_done) {
5777 struct sctp_af *af;
5778 chunk->ecn_ce_done = 1;
5779
5780 af = sctp_get_af_specific(
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07005781 ipver2af(ip_hdr(chunk->skb)->version));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005782
5783 if (af && af->is_ce(chunk->skb) && asoc->peer.ecn_capable) {
5784 /* Do real work as sideffect. */
5785 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_CE,
5786 SCTP_U32(tsn));
5787 }
5788 }
5789
5790 tmp = sctp_tsnmap_check(&asoc->peer.tsn_map, tsn);
5791 if (tmp < 0) {
5792 /* The TSN is too high--silently discard the chunk and
5793 * count on it getting retransmitted later.
5794 */
5795 return SCTP_IERROR_HIGH_TSN;
5796 } else if (tmp > 0) {
5797 /* This is a duplicate. Record it. */
5798 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_DUP, SCTP_U32(tsn));
5799 return SCTP_IERROR_DUP_TSN;
5800 }
5801
5802 /* This is a new TSN. */
5803
5804 /* Discard if there is no room in the receive window.
5805 * Actually, allow a little bit of overflow (up to a MTU).
5806 */
5807 datalen = ntohs(chunk->chunk_hdr->length);
5808 datalen -= sizeof(sctp_data_chunk_t);
5809
5810 deliver = SCTP_CMD_CHUNK_ULP;
5811
5812 /* Think about partial delivery. */
5813 if ((datalen >= asoc->rwnd) && (!asoc->ulpq.pd_mode)) {
5814
5815 /* Even if we don't accept this chunk there is
5816 * memory pressure.
5817 */
5818 sctp_add_cmd_sf(commands, SCTP_CMD_PART_DELIVER, SCTP_NULL());
5819 }
5820
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09005821 /* Spill over rwnd a little bit. Note: While allowed, this spill over
Linus Torvalds1da177e2005-04-16 15:20:36 -07005822 * seems a bit troublesome in that frag_point varies based on
5823 * PMTU. In cases, such as loopback, this might be a rather
5824 * large spill over.
5825 */
Neil Horman4d93df02007-08-15 16:07:44 -07005826 if ((!chunk->data_accepted) && (!asoc->rwnd || asoc->rwnd_over ||
5827 (datalen > asoc->rwnd + asoc->frag_point))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07005828
5829 /* If this is the next TSN, consider reneging to make
5830 * room. Note: Playing nice with a confused sender. A
5831 * malicious sender can still eat up all our buffer
5832 * space and in the future we may want to detect and
5833 * do more drastic reneging.
5834 */
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005835 if (sctp_tsnmap_has_gap(map) &&
5836 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07005837 SCTP_DEBUG_PRINTK("Reneging for tsn:%u\n", tsn);
5838 deliver = SCTP_CMD_RENEGE;
5839 } else {
5840 SCTP_DEBUG_PRINTK("Discard tsn: %u len: %Zd, "
5841 "rwnd: %d\n", tsn, datalen,
5842 asoc->rwnd);
5843 return SCTP_IERROR_IGNORE_TSN;
5844 }
5845 }
5846
5847 /*
Neil Horman4d93df02007-08-15 16:07:44 -07005848 * Also try to renege to limit our memory usage in the event that
5849 * we are under memory pressure
Hideo Aoki3ab224b2007-12-31 00:11:19 -08005850 * If we can't renege, don't worry about it, the sk_rmem_schedule
Neil Horman4d93df02007-08-15 16:07:44 -07005851 * in sctp_ulpevent_make_rcvmsg will drop the frame if we grow our
5852 * memory usage too much
5853 */
5854 if (*sk->sk_prot_creator->memory_pressure) {
5855 if (sctp_tsnmap_has_gap(map) &&
5856 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
5857 SCTP_DEBUG_PRINTK("Under Pressure! Reneging for tsn:%u\n", tsn);
5858 deliver = SCTP_CMD_RENEGE;
5859 }
5860 }
5861
5862 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -07005863 * Section 3.3.10.9 No User Data (9)
5864 *
5865 * Cause of error
5866 * ---------------
5867 * No User Data: This error cause is returned to the originator of a
5868 * DATA chunk if a received DATA chunk has no user data.
5869 */
5870 if (unlikely(0 == datalen)) {
5871 err = sctp_make_abort_no_data(asoc, chunk, tsn);
5872 if (err) {
5873 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
5874 SCTP_CHUNK(err));
5875 }
5876 /* We are going to ABORT, so we might as well stop
5877 * processing the rest of the chunks in the packet.
5878 */
5879 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07005880 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5881 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005882 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08005883 SCTP_PERR(SCTP_ERROR_NO_DATA));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005884 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
5885 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
5886 return SCTP_IERROR_NO_DATA;
5887 }
5888
5889 /* If definately accepting the DATA chunk, record its TSN, otherwise
5890 * wait for renege processing.
5891 */
5892 if (SCTP_CMD_CHUNK_ULP == deliver)
5893 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_TSN, SCTP_U32(tsn));
5894
Sridhar Samudrala9faa7302006-07-21 14:49:07 -07005895 chunk->data_accepted = 1;
5896
Linus Torvalds1da177e2005-04-16 15:20:36 -07005897 /* Note: Some chunks may get overcounted (if we drop) or overcounted
5898 * if we renege and the chunk arrives again.
5899 */
5900 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
5901 SCTP_INC_STATS(SCTP_MIB_INUNORDERCHUNKS);
5902 else
5903 SCTP_INC_STATS(SCTP_MIB_INORDERCHUNKS);
5904
5905 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
5906 *
5907 * If an endpoint receive a DATA chunk with an invalid stream
5908 * identifier, it shall acknowledge the reception of the DATA chunk
5909 * following the normal procedure, immediately send an ERROR chunk
5910 * with cause set to "Invalid Stream Identifier" (See Section 3.3.10)
5911 * and discard the DATA chunk.
5912 */
5913 if (ntohs(data_hdr->stream) >= asoc->c.sinit_max_instreams) {
5914 err = sctp_make_op_error(asoc, chunk, SCTP_ERROR_INV_STRM,
5915 &data_hdr->stream,
5916 sizeof(data_hdr->stream));
5917 if (err)
5918 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
5919 SCTP_CHUNK(err));
5920 return SCTP_IERROR_BAD_STREAM;
5921 }
5922
5923 /* Send the data up to the user. Note: Schedule the
5924 * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK
5925 * chunk needs the updated rwnd.
5926 */
5927 sctp_add_cmd_sf(commands, deliver, SCTP_CHUNK(chunk));
5928
5929 return SCTP_IERROR_NO_ERROR;
5930}