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Vlad Yasevich60c778b2008-01-11 09:57:09 -05001/* SCTP kernel implementation
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999-2000 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 * Copyright (c) 2001-2002 Intel Corp.
6 * Copyright (c) 2002 Nokia Corp.
7 *
Vlad Yasevich60c778b2008-01-11 09:57:09 -05008 * This is part of the SCTP Linux Kernel Implementation.
Linus Torvalds1da177e2005-04-16 15:20:36 -07009 *
10 * These are the state functions for the state machine.
11 *
Vlad Yasevich60c778b2008-01-11 09:57:09 -050012 * This SCTP implementation is free software;
Linus Torvalds1da177e2005-04-16 15:20:36 -070013 * you can redistribute it and/or modify it under the terms of
14 * the GNU General Public License as published by
15 * the Free Software Foundation; either version 2, or (at your option)
16 * any later version.
17 *
Vlad Yasevich60c778b2008-01-11 09:57:09 -050018 * This SCTP implementation is distributed in the hope that it
Linus Torvalds1da177e2005-04-16 15:20:36 -070019 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
20 * ************************
21 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
22 * See the GNU General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License
25 * along with GNU CC; see the file COPYING. If not, write to
26 * the Free Software Foundation, 59 Temple Place - Suite 330,
27 * Boston, MA 02111-1307, USA.
28 *
29 * Please send any bug reports or fixes you make to the
30 * email address(es):
31 * lksctp developers <lksctp-developers@lists.sourceforge.net>
32 *
33 * Or submit a bug report through the following website:
34 * http://www.sf.net/projects/lksctp
35 *
36 * Written or modified by:
37 * La Monte H.P. Yarroll <piggy@acm.org>
38 * Karl Knutson <karl@athena.chicago.il.us>
39 * Mathew Kotowsky <kotowsky@sctp.org>
40 * Sridhar Samudrala <samudrala@us.ibm.com>
41 * Jon Grimm <jgrimm@us.ibm.com>
42 * Hui Huang <hui.huang@nokia.com>
43 * Dajiang Zhang <dajiang.zhang@nokia.com>
44 * Daisy Chang <daisyc@us.ibm.com>
45 * Ardelle Fan <ardelle.fan@intel.com>
46 * Ryan Layer <rmlayer@us.ibm.com>
47 * Kevin Gao <kevin.gao@intel.com>
48 *
49 * Any bugs reported given to us we will try to fix... any fixes shared will
50 * be incorporated into the next SCTP release.
51 */
52
53#include <linux/types.h>
54#include <linux/kernel.h>
55#include <linux/ip.h>
56#include <linux/ipv6.h>
57#include <linux/net.h>
58#include <linux/inet.h>
59#include <net/sock.h>
60#include <net/inet_ecn.h>
61#include <linux/skbuff.h>
62#include <net/sctp/sctp.h>
63#include <net/sctp/sm.h>
64#include <net/sctp/structs.h>
65
66static struct sctp_packet *sctp_abort_pkt_new(const struct sctp_endpoint *ep,
67 const struct sctp_association *asoc,
68 struct sctp_chunk *chunk,
69 const void *payload,
70 size_t paylen);
71static int sctp_eat_data(const struct sctp_association *asoc,
72 struct sctp_chunk *chunk,
73 sctp_cmd_seq_t *commands);
74static struct sctp_packet *sctp_ootb_pkt_new(const struct sctp_association *asoc,
75 const struct sctp_chunk *chunk);
76static void sctp_send_stale_cookie_err(const struct sctp_endpoint *ep,
77 const struct sctp_association *asoc,
78 const struct sctp_chunk *chunk,
79 sctp_cmd_seq_t *commands,
80 struct sctp_chunk *err_chunk);
81static sctp_disposition_t sctp_sf_do_5_2_6_stale(const struct sctp_endpoint *ep,
82 const struct sctp_association *asoc,
83 const sctp_subtype_t type,
84 void *arg,
85 sctp_cmd_seq_t *commands);
86static sctp_disposition_t sctp_sf_shut_8_4_5(const struct sctp_endpoint *ep,
87 const struct sctp_association *asoc,
88 const sctp_subtype_t type,
89 void *arg,
90 sctp_cmd_seq_t *commands);
Vlad Yasevichece25df2007-09-07 16:30:54 -040091static sctp_disposition_t sctp_sf_tabort_8_4_8(const struct sctp_endpoint *ep,
92 const struct sctp_association *asoc,
93 const sctp_subtype_t type,
94 void *arg,
95 sctp_cmd_seq_t *commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -070096static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk);
97
Adrian Bunk52c1da32005-06-23 22:05:33 -070098static sctp_disposition_t sctp_stop_t1_and_abort(sctp_cmd_seq_t *commands,
Al Virof94c0192006-11-20 17:00:25 -080099 __be16 error, int sk_err,
Adrian Bunk52c1da32005-06-23 22:05:33 -0700100 const struct sctp_association *asoc,
101 struct sctp_transport *transport);
102
Wei Yongjunaecedea2007-08-02 16:57:44 +0800103static sctp_disposition_t sctp_sf_abort_violation(
Vlad Yasevichece25df2007-09-07 16:30:54 -0400104 const struct sctp_endpoint *ep,
Wei Yongjunaecedea2007-08-02 16:57:44 +0800105 const struct sctp_association *asoc,
106 void *arg,
107 sctp_cmd_seq_t *commands,
108 const __u8 *payload,
109 const size_t paylen);
110
Adrian Bunk52c1da32005-06-23 22:05:33 -0700111static sctp_disposition_t sctp_sf_violation_chunklen(
112 const struct sctp_endpoint *ep,
113 const struct sctp_association *asoc,
114 const sctp_subtype_t type,
115 void *arg,
116 sctp_cmd_seq_t *commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117
Wei Yongjun6f4c6182007-09-19 17:19:52 +0800118static sctp_disposition_t sctp_sf_violation_paramlen(
119 const struct sctp_endpoint *ep,
120 const struct sctp_association *asoc,
121 const sctp_subtype_t type,
Wei Yongjunba016672008-09-30 05:32:24 -0700122 void *arg, void *ext,
Wei Yongjun6f4c6182007-09-19 17:19:52 +0800123 sctp_cmd_seq_t *commands);
124
Wei Yongjunaecedea2007-08-02 16:57:44 +0800125static sctp_disposition_t sctp_sf_violation_ctsn(
126 const struct sctp_endpoint *ep,
127 const struct sctp_association *asoc,
128 const sctp_subtype_t type,
129 void *arg,
130 sctp_cmd_seq_t *commands);
131
Vlad Yasevichece25df2007-09-07 16:30:54 -0400132static sctp_disposition_t sctp_sf_violation_chunk(
133 const struct sctp_endpoint *ep,
134 const struct sctp_association *asoc,
135 const sctp_subtype_t type,
136 void *arg,
137 sctp_cmd_seq_t *commands);
138
Vlad Yasevichbbd0d592007-10-03 17:51:34 -0700139static sctp_ierror_t sctp_sf_authenticate(const struct sctp_endpoint *ep,
140 const struct sctp_association *asoc,
141 const sctp_subtype_t type,
142 struct sctp_chunk *chunk);
143
Vlad Yasevich75205f42007-12-20 14:12:59 -0800144static sctp_disposition_t __sctp_sf_do_9_1_abort(const struct sctp_endpoint *ep,
145 const struct sctp_association *asoc,
146 const sctp_subtype_t type,
147 void *arg,
148 sctp_cmd_seq_t *commands);
149
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150/* Small helper function that checks if the chunk length
151 * is of the appropriate length. The 'required_length' argument
152 * is set to be the size of a specific chunk we are testing.
153 * Return Values: 1 = Valid length
154 * 0 = Invalid length
155 *
156 */
157static inline int
158sctp_chunk_length_valid(struct sctp_chunk *chunk,
159 __u16 required_length)
160{
161 __u16 chunk_length = ntohs(chunk->chunk_hdr->length);
162
163 if (unlikely(chunk_length < required_length))
164 return 0;
165
166 return 1;
167}
168
169/**********************************************************
170 * These are the state functions for handling chunk events.
171 **********************************************************/
172
173/*
174 * Process the final SHUTDOWN COMPLETE.
175 *
176 * Section: 4 (C) (diagram), 9.2
177 * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify
178 * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be
179 * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint
180 * should stop the T2-shutdown timer and remove all knowledge of the
181 * association (and thus the association enters the CLOSED state).
182 *
Jerome Forissier047a2422005-04-28 11:58:43 -0700183 * Verification Tag: 8.5.1(C), sctpimpguide 2.41.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184 * C) Rules for packet carrying SHUTDOWN COMPLETE:
185 * ...
Jerome Forissier047a2422005-04-28 11:58:43 -0700186 * - The receiver of a SHUTDOWN COMPLETE shall accept the packet
187 * if the Verification Tag field of the packet matches its own tag and
188 * the T bit is not set
189 * OR
190 * it is set to its peer's tag and the T bit is set in the Chunk
191 * Flags.
192 * Otherwise, the receiver MUST silently discard the packet
193 * and take no further action. An endpoint MUST ignore the
194 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195 *
196 * Inputs
197 * (endpoint, asoc, chunk)
198 *
199 * Outputs
200 * (asoc, reply_msg, msg_up, timers, counters)
201 *
202 * The return value is the disposition of the chunk.
203 */
204sctp_disposition_t sctp_sf_do_4_C(const struct sctp_endpoint *ep,
205 const struct sctp_association *asoc,
206 const sctp_subtype_t type,
207 void *arg,
208 sctp_cmd_seq_t *commands)
209{
210 struct sctp_chunk *chunk = arg;
211 struct sctp_ulpevent *ev;
212
Vlad Yasevichece25df2007-09-07 16:30:54 -0400213 if (!sctp_vtag_verify_either(chunk, asoc))
214 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
215
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 /* RFC 2960 6.10 Bundling
217 *
218 * An endpoint MUST NOT bundle INIT, INIT ACK or
219 * SHUTDOWN COMPLETE with any other chunks.
220 */
221 if (!chunk->singleton)
Vlad Yasevichece25df2007-09-07 16:30:54 -0400222 return sctp_sf_violation_chunk(ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223
Vlad Yasevichece25df2007-09-07 16:30:54 -0400224 /* Make sure that the SHUTDOWN_COMPLETE chunk has a valid length. */
225 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
226 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
227 commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228
229 /* RFC 2960 10.2 SCTP-to-ULP
230 *
231 * H) SHUTDOWN COMPLETE notification
232 *
233 * When SCTP completes the shutdown procedures (section 9.2) this
234 * notification is passed to the upper layer.
235 */
236 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
Vlad Yasevicha5a35e72007-03-23 11:34:08 -0700237 0, 0, 0, NULL, GFP_ATOMIC);
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700238 if (ev)
239 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900240 SCTP_ULPEVENT(ev));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241
242 /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint
243 * will verify that it is in SHUTDOWN-ACK-SENT state, if it is
244 * not the chunk should be discarded. If the endpoint is in
245 * the SHUTDOWN-ACK-SENT state the endpoint should stop the
246 * T2-shutdown timer and remove all knowledge of the
247 * association (and thus the association enters the CLOSED
248 * state).
249 */
250 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
251 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
252
253 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
254 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
255
256 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
257 SCTP_STATE(SCTP_STATE_CLOSED));
258
259 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
260 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
261
262 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
263
264 return SCTP_DISPOSITION_DELETE_TCB;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265}
266
267/*
268 * Respond to a normal INIT chunk.
269 * We are the side that is being asked for an association.
270 *
271 * Section: 5.1 Normal Establishment of an Association, B
272 * B) "Z" shall respond immediately with an INIT ACK chunk. The
273 * destination IP address of the INIT ACK MUST be set to the source
274 * IP address of the INIT to which this INIT ACK is responding. In
275 * the response, besides filling in other parameters, "Z" must set the
276 * Verification Tag field to Tag_A, and also provide its own
277 * Verification Tag (Tag_Z) in the Initiate Tag field.
278 *
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900279 * Verification Tag: Must be 0.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280 *
281 * Inputs
282 * (endpoint, asoc, chunk)
283 *
284 * Outputs
285 * (asoc, reply_msg, msg_up, timers, counters)
286 *
287 * The return value is the disposition of the chunk.
288 */
289sctp_disposition_t sctp_sf_do_5_1B_init(const struct sctp_endpoint *ep,
290 const struct sctp_association *asoc,
291 const sctp_subtype_t type,
292 void *arg,
293 sctp_cmd_seq_t *commands)
294{
295 struct sctp_chunk *chunk = arg;
296 struct sctp_chunk *repl;
297 struct sctp_association *new_asoc;
298 struct sctp_chunk *err_chunk;
299 struct sctp_packet *packet;
300 sctp_unrecognized_param_t *unk_param;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301 int len;
302
303 /* 6.10 Bundling
304 * An endpoint MUST NOT bundle INIT, INIT ACK or
305 * SHUTDOWN COMPLETE with any other chunks.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900306 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307 * IG Section 2.11.2
308 * Furthermore, we require that the receiver of an INIT chunk MUST
309 * enforce these rules by silently discarding an arriving packet
310 * with an INIT chunk that is bundled with other chunks.
311 */
312 if (!chunk->singleton)
313 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
314
315 /* If the packet is an OOTB packet which is temporarily on the
316 * control endpoint, respond with an ABORT.
317 */
Wei Yongjun8190f892008-09-08 12:13:55 +0800318 if (ep == sctp_sk((sctp_get_ctl_sock()))->ep) {
319 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700320 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
Wei Yongjun8190f892008-09-08 12:13:55 +0800321 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322
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 */
Wei Yongjun8190f892008-09-08 12:13:55 +0800640 if (ep == sctp_sk((sctp_get_ctl_sock()))->ep) {
641 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES);
Vlad Yasevichece25df2007-09-07 16:30:54 -0400642 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
Wei Yongjun8190f892008-09-08 12:13:55 +0800643 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644
645 /* Make sure that the COOKIE_ECHO chunk has a valid length.
646 * In this case, we check that we have enough for at least a
647 * chunk header. More detailed verification is done
648 * in sctp_unpack_cookie().
649 */
650 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
651 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
652
Vlad Yasevich609ee462007-08-31 03:10:59 +0900653 /* If the endpoint is not listening or if the number of associations
654 * on the TCP-style socket exceed the max backlog, respond with an
655 * ABORT.
656 */
657 sk = ep->base.sk;
658 if (!sctp_sstate(sk, LISTENING) ||
659 (sctp_style(sk, TCP) && sk_acceptq_is_full(sk)))
660 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
661
Linus Torvalds1da177e2005-04-16 15:20:36 -0700662 /* "Decode" the chunk. We have no optional parameters so we
663 * are in good shape.
664 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900665 chunk->subh.cookie_hdr =
Linus Torvalds1da177e2005-04-16 15:20:36 -0700666 (struct sctp_signed_cookie *)chunk->skb->data;
Sridhar Samudrala62b08082006-05-05 17:04:43 -0700667 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
668 sizeof(sctp_chunkhdr_t)))
669 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670
671 /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
672 * "Z" will reply with a COOKIE ACK chunk after building a TCB
673 * and moving to the ESTABLISHED state.
674 */
675 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
676 &err_chk_p);
677
678 /* FIXME:
679 * If the re-build failed, what is the proper error path
680 * from here?
681 *
682 * [We should abort the association. --piggy]
683 */
684 if (!new_asoc) {
685 /* FIXME: Several errors are possible. A bad cookie should
686 * be silently discarded, but think about logging it too.
687 */
688 switch (error) {
689 case -SCTP_IERROR_NOMEM:
690 goto nomem;
691
692 case -SCTP_IERROR_STALE_COOKIE:
693 sctp_send_stale_cookie_err(ep, asoc, chunk, commands,
694 err_chk_p);
695 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
696
697 case -SCTP_IERROR_BAD_SIG:
698 default:
699 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700700 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701 }
702
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700704 /* Delay state machine commands until later.
705 *
706 * Re-build the bind address for the association is done in
Linus Torvalds1da177e2005-04-16 15:20:36 -0700707 * the sctp_unpack_cookie() already.
708 */
709 /* This is a brand-new association, so these are not yet side
710 * effects--it is safe to run them here.
711 */
712 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
713
714 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
Al Viro6a1e5f32006-11-20 17:12:25 -0800715 &chunk->subh.cookie_hdr->c.peer_addr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700716 peer_init, GFP_ATOMIC))
717 goto nomem_init;
718
Vlad Yasevich730fc3d2007-09-16 19:32:11 -0700719 /* SCTP-AUTH: Now that we've populate required fields in
720 * sctp_process_init, set up the assocaition shared keys as
721 * necessary so that we can potentially authenticate the ACK
722 */
723 error = sctp_auth_asoc_init_active_key(new_asoc, GFP_ATOMIC);
724 if (error)
725 goto nomem_init;
726
Vlad Yasevichbbd0d592007-10-03 17:51:34 -0700727 /* SCTP-AUTH: auth_chunk pointer is only set when the cookie-echo
728 * is supposed to be authenticated and we have to do delayed
729 * authentication. We've just recreated the association using
730 * the information in the cookie and now it's much easier to
731 * do the authentication.
732 */
733 if (chunk->auth_chunk) {
734 struct sctp_chunk auth;
735 sctp_ierror_t ret;
736
737 /* set-up our fake chunk so that we can process it */
738 auth.skb = chunk->auth_chunk;
739 auth.asoc = chunk->asoc;
740 auth.sctp_hdr = chunk->sctp_hdr;
741 auth.chunk_hdr = (sctp_chunkhdr_t *)skb_push(chunk->auth_chunk,
742 sizeof(sctp_chunkhdr_t));
743 skb_pull(chunk->auth_chunk, sizeof(sctp_chunkhdr_t));
744 auth.transport = chunk->transport;
745
746 ret = sctp_sf_authenticate(ep, new_asoc, type, &auth);
747
748 /* We can now safely free the auth_chunk clone */
749 kfree_skb(chunk->auth_chunk);
750
751 if (ret != SCTP_IERROR_NO_ERROR) {
752 sctp_association_free(new_asoc);
753 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
754 }
755 }
756
Linus Torvalds1da177e2005-04-16 15:20:36 -0700757 repl = sctp_make_cookie_ack(new_asoc, chunk);
758 if (!repl)
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700759 goto nomem_init;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700760
761 /* RFC 2960 5.1 Normal Establishment of an Association
762 *
763 * D) IMPLEMENTATION NOTE: An implementation may choose to
764 * send the Communication Up notification to the SCTP user
765 * upon reception of a valid COOKIE ECHO chunk.
766 */
767 ev = sctp_ulpevent_make_assoc_change(new_asoc, 0, SCTP_COMM_UP, 0,
768 new_asoc->c.sinit_num_ostreams,
769 new_asoc->c.sinit_max_instreams,
Vlad Yasevicha5a35e72007-03-23 11:34:08 -0700770 NULL, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700771 if (!ev)
772 goto nomem_ev;
773
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900774 /* Sockets API Draft Section 5.3.1.6
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -0800775 * When a peer sends a Adaptation Layer Indication parameter , SCTP
Linus Torvalds1da177e2005-04-16 15:20:36 -0700776 * delivers this notification to inform the application that of the
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -0800777 * peers requested adaptation layer.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700778 */
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -0800779 if (new_asoc->peer.adaptation_ind) {
780 ai_ev = sctp_ulpevent_make_adaptation_indication(new_asoc,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700781 GFP_ATOMIC);
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700782 if (!ai_ev)
783 goto nomem_aiev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700784 }
785
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700786 /* Add all the state machine commands now since we've created
787 * everything. This way we don't introduce memory corruptions
788 * during side-effect processing and correclty count established
789 * associations.
790 */
791 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
792 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
793 SCTP_STATE(SCTP_STATE_ESTABLISHED));
794 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
795 SCTP_INC_STATS(SCTP_MIB_PASSIVEESTABS);
796 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
797
798 if (new_asoc->autoclose)
799 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
800 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
801
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700802 /* 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));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700888
889 /* It may also notify its ULP about the successful
890 * establishment of the association with a Communication Up
891 * notification (see Section 10).
892 */
893 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP,
894 0, asoc->c.sinit_num_ostreams,
895 asoc->c.sinit_max_instreams,
Vlad Yasevicha5a35e72007-03-23 11:34:08 -0700896 NULL, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700897
898 if (!ev)
899 goto nomem;
900
901 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
902
903 /* Sockets API Draft Section 5.3.1.6
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -0800904 * When a peer sends a Adaptation Layer Indication parameter , SCTP
Linus Torvalds1da177e2005-04-16 15:20:36 -0700905 * delivers this notification to inform the application that of the
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -0800906 * peers requested adaptation layer.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700907 */
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -0800908 if (asoc->peer.adaptation_ind) {
909 ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700910 if (!ev)
911 goto nomem;
912
913 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
914 SCTP_ULPEVENT(ev));
915 }
916
917 return SCTP_DISPOSITION_CONSUME;
918nomem:
919 return SCTP_DISPOSITION_NOMEM;
920}
921
922/* Generate and sendout a heartbeat packet. */
923static sctp_disposition_t sctp_sf_heartbeat(const struct sctp_endpoint *ep,
924 const struct sctp_association *asoc,
925 const sctp_subtype_t type,
926 void *arg,
927 sctp_cmd_seq_t *commands)
928{
929 struct sctp_transport *transport = (struct sctp_transport *) arg;
930 struct sctp_chunk *reply;
931 sctp_sender_hb_info_t hbinfo;
932 size_t paylen = 0;
933
934 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO;
935 hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t));
Al Viro63de08f2006-11-20 17:07:25 -0800936 hbinfo.daddr = transport->ipaddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700937 hbinfo.sent_at = jiffies;
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700938 hbinfo.hb_nonce = transport->hb_nonce;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700939
940 /* Send a heartbeat to our peer. */
941 paylen = sizeof(sctp_sender_hb_info_t);
942 reply = sctp_make_heartbeat(asoc, transport, &hbinfo, paylen);
943 if (!reply)
944 return SCTP_DISPOSITION_NOMEM;
945
946 /* Set rto_pending indicating that an RTT measurement
947 * is started with this heartbeat chunk.
948 */
949 sctp_add_cmd_sf(commands, SCTP_CMD_RTO_PENDING,
950 SCTP_TRANSPORT(transport));
951
952 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
953 return SCTP_DISPOSITION_CONSUME;
954}
955
956/* Generate a HEARTBEAT packet on the given transport. */
957sctp_disposition_t sctp_sf_sendbeat_8_3(const struct sctp_endpoint *ep,
958 const struct sctp_association *asoc,
959 const sctp_subtype_t type,
960 void *arg,
961 sctp_cmd_seq_t *commands)
962{
963 struct sctp_transport *transport = (struct sctp_transport *) arg;
964
Vlad Yasevichfd102792007-11-15 12:13:32 -0500965 if (asoc->overall_error_count > asoc->max_retrans) {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700966 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
967 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700968 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
969 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -0800970 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700971 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
972 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
973 return SCTP_DISPOSITION_DELETE_TCB;
974 }
975
976 /* Section 3.3.5.
977 * The Sender-specific Heartbeat Info field should normally include
978 * information about the sender's current time when this HEARTBEAT
979 * chunk is sent and the destination transport address to which this
980 * HEARTBEAT is sent (see Section 8.3).
981 */
982
Frank Filz52ccb8e2005-12-22 11:36:46 -0800983 if (transport->param_flags & SPP_HB_ENABLE) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700984 if (SCTP_DISPOSITION_NOMEM ==
985 sctp_sf_heartbeat(ep, asoc, type, arg,
986 commands))
987 return SCTP_DISPOSITION_NOMEM;
988 /* Set transport error counter and association error counter
989 * when sending heartbeat.
990 */
991 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_RESET,
992 SCTP_TRANSPORT(transport));
993 }
994 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMER_UPDATE,
995 SCTP_TRANSPORT(transport));
996
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900997 return SCTP_DISPOSITION_CONSUME;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700998}
999
1000/*
1001 * Process an heartbeat request.
1002 *
1003 * Section: 8.3 Path Heartbeat
1004 * The receiver of the HEARTBEAT should immediately respond with a
1005 * HEARTBEAT ACK that contains the Heartbeat Information field copied
1006 * from the received HEARTBEAT chunk.
1007 *
1008 * Verification Tag: 8.5 Verification Tag [Normal verification]
1009 * When receiving an SCTP packet, the endpoint MUST ensure that the
1010 * value in the Verification Tag field of the received SCTP packet
1011 * matches its own Tag. If the received Verification Tag value does not
1012 * match the receiver's own tag value, the receiver shall silently
1013 * discard the packet and shall not process it any further except for
1014 * those cases listed in Section 8.5.1 below.
1015 *
1016 * Inputs
1017 * (endpoint, asoc, chunk)
1018 *
1019 * Outputs
1020 * (asoc, reply_msg, msg_up, timers, counters)
1021 *
1022 * The return value is the disposition of the chunk.
1023 */
1024sctp_disposition_t sctp_sf_beat_8_3(const struct sctp_endpoint *ep,
1025 const struct sctp_association *asoc,
1026 const sctp_subtype_t type,
1027 void *arg,
1028 sctp_cmd_seq_t *commands)
1029{
1030 struct sctp_chunk *chunk = arg;
1031 struct sctp_chunk *reply;
1032 size_t paylen = 0;
1033
1034 if (!sctp_vtag_verify(chunk, asoc))
1035 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1036
1037 /* Make sure that the HEARTBEAT chunk has a valid length. */
1038 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t)))
1039 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1040 commands);
1041
1042 /* 8.3 The receiver of the HEARTBEAT should immediately
1043 * respond with a HEARTBEAT ACK that contains the Heartbeat
1044 * Information field copied from the received HEARTBEAT chunk.
1045 */
1046 chunk->subh.hb_hdr = (sctp_heartbeathdr_t *) chunk->skb->data;
1047 paylen = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
Sridhar Samudrala62b08082006-05-05 17:04:43 -07001048 if (!pskb_pull(chunk->skb, paylen))
1049 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001050
1051 reply = sctp_make_heartbeat_ack(asoc, chunk,
1052 chunk->subh.hb_hdr, paylen);
1053 if (!reply)
1054 goto nomem;
1055
1056 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
1057 return SCTP_DISPOSITION_CONSUME;
1058
1059nomem:
1060 return SCTP_DISPOSITION_NOMEM;
1061}
1062
1063/*
1064 * Process the returning HEARTBEAT ACK.
1065 *
1066 * Section: 8.3 Path Heartbeat
1067 * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT
1068 * should clear the error counter of the destination transport
1069 * address to which the HEARTBEAT was sent, and mark the destination
1070 * transport address as active if it is not so marked. The endpoint may
1071 * optionally report to the upper layer when an inactive destination
1072 * address is marked as active due to the reception of the latest
1073 * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also
1074 * clear the association overall error count as well (as defined
1075 * in section 8.1).
1076 *
1077 * The receiver of the HEARTBEAT ACK should also perform an RTT
1078 * measurement for that destination transport address using the time
1079 * value carried in the HEARTBEAT ACK chunk.
1080 *
1081 * Verification Tag: 8.5 Verification Tag [Normal verification]
1082 *
1083 * Inputs
1084 * (endpoint, asoc, chunk)
1085 *
1086 * Outputs
1087 * (asoc, reply_msg, msg_up, timers, counters)
1088 *
1089 * The return value is the disposition of the chunk.
1090 */
1091sctp_disposition_t sctp_sf_backbeat_8_3(const struct sctp_endpoint *ep,
1092 const struct sctp_association *asoc,
1093 const sctp_subtype_t type,
1094 void *arg,
1095 sctp_cmd_seq_t *commands)
1096{
1097 struct sctp_chunk *chunk = arg;
1098 union sctp_addr from_addr;
1099 struct sctp_transport *link;
1100 sctp_sender_hb_info_t *hbinfo;
1101 unsigned long max_interval;
1102
1103 if (!sctp_vtag_verify(chunk, asoc))
1104 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1105
1106 /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */
1107 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t)))
1108 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1109 commands);
1110
1111 hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
Vladislav Yasevicha6012662006-05-19 14:25:53 -07001112 /* Make sure that the length of the parameter is what we expect */
1113 if (ntohs(hbinfo->param_hdr.length) !=
1114 sizeof(sctp_sender_hb_info_t)) {
1115 return SCTP_DISPOSITION_DISCARD;
1116 }
1117
Linus Torvalds1da177e2005-04-16 15:20:36 -07001118 from_addr = hbinfo->daddr;
Al Viro63de08f2006-11-20 17:07:25 -08001119 link = sctp_assoc_lookup_paddr(asoc, &from_addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001120
1121 /* This should never happen, but lets log it if so. */
Frank Filz3f7a87d2005-06-20 13:14:57 -07001122 if (unlikely(!link)) {
1123 if (from_addr.sa.sa_family == AF_INET6) {
Wei Yongjund99fa422007-08-27 11:19:24 +08001124 if (net_ratelimit())
1125 printk(KERN_WARNING
Harvey Harrison5b095d9892008-10-29 12:52:50 -07001126 "%s association %p could not find address %pI6\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001127 __func__,
Wei Yongjund99fa422007-08-27 11:19:24 +08001128 asoc,
Harvey Harrisonfdb46ee2008-10-28 16:10:17 -07001129 &from_addr.v6.sin6_addr);
Frank Filz3f7a87d2005-06-20 13:14:57 -07001130 } else {
Wei Yongjund99fa422007-08-27 11:19:24 +08001131 if (net_ratelimit())
1132 printk(KERN_WARNING
Harvey Harrison21454aa2008-10-31 00:54:56 -07001133 "%s association %p could not find address %pI4\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001134 __func__,
Wei Yongjund99fa422007-08-27 11:19:24 +08001135 asoc,
Harvey Harrison21454aa2008-10-31 00:54:56 -07001136 &from_addr.v4.sin_addr.s_addr);
Frank Filz3f7a87d2005-06-20 13:14:57 -07001137 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001138 return SCTP_DISPOSITION_DISCARD;
1139 }
1140
Sridhar Samudralaad8fec12006-07-21 14:48:50 -07001141 /* Validate the 64-bit random nonce. */
1142 if (hbinfo->hb_nonce != link->hb_nonce)
1143 return SCTP_DISPOSITION_DISCARD;
1144
Frank Filz52ccb8e2005-12-22 11:36:46 -08001145 max_interval = link->hbinterval + link->rto;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001146
1147 /* Check if the timestamp looks valid. */
1148 if (time_after(hbinfo->sent_at, jiffies) ||
1149 time_after(jiffies, hbinfo->sent_at + max_interval)) {
Joe Perches9ee46f12007-11-19 23:47:47 -08001150 SCTP_DEBUG_PRINTK("%s: HEARTBEAT ACK with invalid timestamp "
Linus Torvalds1da177e2005-04-16 15:20:36 -07001151 "received for transport: %p\n",
Harvey Harrison0dc47872008-03-05 20:47:47 -08001152 __func__, link);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001153 return SCTP_DISPOSITION_DISCARD;
1154 }
1155
1156 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of
1157 * the HEARTBEAT should clear the error counter of the
1158 * destination transport address to which the HEARTBEAT was
1159 * sent and mark the destination transport address as active if
1160 * it is not so marked.
1161 */
1162 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_ON, SCTP_TRANSPORT(link));
1163
1164 return SCTP_DISPOSITION_CONSUME;
1165}
1166
1167/* Helper function to send out an abort for the restart
1168 * condition.
1169 */
1170static int sctp_sf_send_restart_abort(union sctp_addr *ssa,
1171 struct sctp_chunk *init,
1172 sctp_cmd_seq_t *commands)
1173{
1174 int len;
1175 struct sctp_packet *pkt;
1176 union sctp_addr_param *addrparm;
1177 struct sctp_errhdr *errhdr;
1178 struct sctp_endpoint *ep;
1179 char buffer[sizeof(struct sctp_errhdr)+sizeof(union sctp_addr_param)];
1180 struct sctp_af *af = sctp_get_af_specific(ssa->v4.sin_family);
1181
1182 /* Build the error on the stack. We are way to malloc crazy
1183 * throughout the code today.
1184 */
1185 errhdr = (struct sctp_errhdr *)buffer;
1186 addrparm = (union sctp_addr_param *)errhdr->variable;
1187
1188 /* Copy into a parm format. */
1189 len = af->to_addr_param(ssa, addrparm);
1190 len += sizeof(sctp_errhdr_t);
1191
1192 errhdr->cause = SCTP_ERROR_RESTART;
1193 errhdr->length = htons(len);
1194
1195 /* Assign to the control socket. */
1196 ep = sctp_sk((sctp_get_ctl_sock()))->ep;
1197
1198 /* Association is NULL since this may be a restart attack and we
1199 * want to send back the attacker's vtag.
1200 */
1201 pkt = sctp_abort_pkt_new(ep, NULL, init, errhdr, len);
1202
1203 if (!pkt)
1204 goto out;
1205 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, SCTP_PACKET(pkt));
1206
1207 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
1208
1209 /* Discard the rest of the inbound packet. */
1210 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
1211
1212out:
1213 /* Even if there is no memory, treat as a failure so
1214 * the packet will get dropped.
1215 */
1216 return 0;
1217}
1218
1219/* A restart is occurring, check to make sure no new addresses
1220 * are being added as we may be under a takeover attack.
1221 */
1222static int sctp_sf_check_restart_addrs(const struct sctp_association *new_asoc,
1223 const struct sctp_association *asoc,
1224 struct sctp_chunk *init,
1225 sctp_cmd_seq_t *commands)
1226{
1227 struct sctp_transport *new_addr, *addr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001228 int found;
1229
1230 /* Implementor's Guide - Sectin 5.2.2
1231 * ...
1232 * Before responding the endpoint MUST check to see if the
1233 * unexpected INIT adds new addresses to the association. If new
1234 * addresses are added to the association, the endpoint MUST respond
1235 * with an ABORT..
1236 */
1237
1238 /* Search through all current addresses and make sure
1239 * we aren't adding any new ones.
1240 */
1241 new_addr = NULL;
1242 found = 0;
1243
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -07001244 list_for_each_entry(new_addr, &new_asoc->peer.transport_addr_list,
1245 transports) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001246 found = 0;
Robert P. J. Day9dbc15f2008-04-12 18:54:24 -07001247 list_for_each_entry(addr, &asoc->peer.transport_addr_list,
1248 transports) {
Al Viro5f242a12006-11-20 17:05:23 -08001249 if (sctp_cmp_addr_exact(&new_addr->ipaddr,
1250 &addr->ipaddr)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001251 found = 1;
1252 break;
1253 }
1254 }
1255 if (!found)
1256 break;
1257 }
1258
1259 /* If a new address was added, ABORT the sender. */
1260 if (!found && new_addr) {
Al Viro7dd8a582006-11-20 17:23:25 -08001261 sctp_sf_send_restart_abort(&new_addr->ipaddr, init, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001262 }
1263
1264 /* Return success if all addresses were found. */
1265 return found;
1266}
1267
1268/* Populate the verification/tie tags based on overlapping INIT
1269 * scenario.
1270 *
1271 * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state.
1272 */
1273static void sctp_tietags_populate(struct sctp_association *new_asoc,
1274 const struct sctp_association *asoc)
1275{
1276 switch (asoc->state) {
1277
1278 /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */
1279
1280 case SCTP_STATE_COOKIE_WAIT:
1281 new_asoc->c.my_vtag = asoc->c.my_vtag;
1282 new_asoc->c.my_ttag = asoc->c.my_vtag;
1283 new_asoc->c.peer_ttag = 0;
1284 break;
1285
1286 case SCTP_STATE_COOKIE_ECHOED:
1287 new_asoc->c.my_vtag = asoc->c.my_vtag;
1288 new_asoc->c.my_ttag = asoc->c.my_vtag;
1289 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1290 break;
1291
1292 /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED,
1293 * COOKIE-WAIT and SHUTDOWN-ACK-SENT
1294 */
1295 default:
1296 new_asoc->c.my_ttag = asoc->c.my_vtag;
1297 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1298 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07001299 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001300
1301 /* Other parameters for the endpoint SHOULD be copied from the
1302 * existing parameters of the association (e.g. number of
1303 * outbound streams) into the INIT ACK and cookie.
1304 */
1305 new_asoc->rwnd = asoc->rwnd;
1306 new_asoc->c.sinit_num_ostreams = asoc->c.sinit_num_ostreams;
1307 new_asoc->c.sinit_max_instreams = asoc->c.sinit_max_instreams;
1308 new_asoc->c.initial_tsn = asoc->c.initial_tsn;
1309}
1310
1311/*
1312 * Compare vtag/tietag values to determine unexpected COOKIE-ECHO
1313 * handling action.
1314 *
1315 * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists.
1316 *
1317 * Returns value representing action to be taken. These action values
1318 * correspond to Action/Description values in RFC 2960, Table 2.
1319 */
1320static char sctp_tietags_compare(struct sctp_association *new_asoc,
1321 const struct sctp_association *asoc)
1322{
1323 /* In this case, the peer may have restarted. */
1324 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1325 (asoc->c.peer_vtag != new_asoc->c.peer_vtag) &&
1326 (asoc->c.my_vtag == new_asoc->c.my_ttag) &&
1327 (asoc->c.peer_vtag == new_asoc->c.peer_ttag))
1328 return 'A';
1329
1330 /* Collision case B. */
1331 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1332 ((asoc->c.peer_vtag != new_asoc->c.peer_vtag) ||
1333 (0 == asoc->c.peer_vtag))) {
1334 return 'B';
1335 }
1336
1337 /* Collision case D. */
1338 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1339 (asoc->c.peer_vtag == new_asoc->c.peer_vtag))
1340 return 'D';
1341
1342 /* Collision case C. */
1343 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1344 (asoc->c.peer_vtag == new_asoc->c.peer_vtag) &&
1345 (0 == new_asoc->c.my_ttag) &&
1346 (0 == new_asoc->c.peer_ttag))
1347 return 'C';
1348
1349 /* No match to any of the special cases; discard this packet. */
1350 return 'E';
1351}
1352
1353/* Common helper routine for both duplicate and simulataneous INIT
1354 * chunk handling.
1355 */
1356static sctp_disposition_t sctp_sf_do_unexpected_init(
1357 const struct sctp_endpoint *ep,
1358 const struct sctp_association *asoc,
1359 const sctp_subtype_t type,
1360 void *arg, sctp_cmd_seq_t *commands)
1361{
1362 sctp_disposition_t retval;
1363 struct sctp_chunk *chunk = arg;
1364 struct sctp_chunk *repl;
1365 struct sctp_association *new_asoc;
1366 struct sctp_chunk *err_chunk;
1367 struct sctp_packet *packet;
1368 sctp_unrecognized_param_t *unk_param;
1369 int len;
1370
1371 /* 6.10 Bundling
1372 * An endpoint MUST NOT bundle INIT, INIT ACK or
1373 * SHUTDOWN COMPLETE with any other chunks.
1374 *
1375 * IG Section 2.11.2
1376 * Furthermore, we require that the receiver of an INIT chunk MUST
1377 * enforce these rules by silently discarding an arriving packet
1378 * with an INIT chunk that is bundled with other chunks.
1379 */
1380 if (!chunk->singleton)
1381 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1382
1383 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001384 * Tag.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001385 */
1386 if (chunk->sctp_hdr->vtag != 0)
1387 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
1388
1389 /* Make sure that the INIT chunk has a valid length.
1390 * In this case, we generate a protocol violation since we have
1391 * an association established.
1392 */
1393 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
1394 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1395 commands);
1396 /* Grab the INIT header. */
1397 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
1398
1399 /* Tag the variable length parameters. */
1400 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
1401
1402 /* Verify the INIT chunk before processing it. */
1403 err_chunk = NULL;
1404 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
1405 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
1406 &err_chunk)) {
1407 /* This chunk contains fatal error. It is to be discarded.
1408 * Send an ABORT, with causes if there is any.
1409 */
1410 if (err_chunk) {
1411 packet = sctp_abort_pkt_new(ep, asoc, arg,
1412 (__u8 *)(err_chunk->chunk_hdr) +
1413 sizeof(sctp_chunkhdr_t),
1414 ntohs(err_chunk->chunk_hdr->length) -
1415 sizeof(sctp_chunkhdr_t));
1416
1417 if (packet) {
1418 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
1419 SCTP_PACKET(packet));
1420 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
1421 retval = SCTP_DISPOSITION_CONSUME;
1422 } else {
1423 retval = SCTP_DISPOSITION_NOMEM;
1424 }
1425 goto cleanup;
1426 } else {
1427 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg,
1428 commands);
1429 }
1430 }
1431
1432 /*
1433 * Other parameters for the endpoint SHOULD be copied from the
1434 * existing parameters of the association (e.g. number of
1435 * outbound streams) into the INIT ACK and cookie.
1436 * FIXME: We are copying parameters from the endpoint not the
1437 * association.
1438 */
1439 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
1440 if (!new_asoc)
1441 goto nomem;
1442
1443 /* In the outbound INIT ACK the endpoint MUST copy its current
1444 * Verification Tag and Peers Verification tag into a reserved
1445 * place (local tie-tag and per tie-tag) within the state cookie.
1446 */
1447 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
1448 sctp_source(chunk),
1449 (sctp_init_chunk_t *)chunk->chunk_hdr,
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001450 GFP_ATOMIC))
1451 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001452
1453 /* Make sure no new addresses are being added during the
1454 * restart. Do not do this check for COOKIE-WAIT state,
1455 * since there are no peer addresses to check against.
1456 * Upon return an ABORT will have been sent if needed.
1457 */
1458 if (!sctp_state(asoc, COOKIE_WAIT)) {
1459 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk,
1460 commands)) {
1461 retval = SCTP_DISPOSITION_CONSUME;
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001462 goto nomem_retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001463 }
1464 }
1465
1466 sctp_tietags_populate(new_asoc, asoc);
1467
1468 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
1469
1470 /* If there are errors need to be reported for unknown parameters,
1471 * make sure to reserve enough room in the INIT ACK for them.
1472 */
1473 len = 0;
1474 if (err_chunk) {
1475 len = ntohs(err_chunk->chunk_hdr->length) -
1476 sizeof(sctp_chunkhdr_t);
1477 }
1478
1479 if (sctp_assoc_set_bind_addr_from_ep(new_asoc, GFP_ATOMIC) < 0)
1480 goto nomem;
1481
1482 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
1483 if (!repl)
1484 goto nomem;
1485
1486 /* If there are errors need to be reported for unknown parameters,
1487 * include them in the outgoing INIT ACK as "Unrecognized parameter"
1488 * parameter.
1489 */
1490 if (err_chunk) {
1491 /* Get the "Unrecognized parameter" parameter(s) out of the
1492 * ERROR chunk generated by sctp_verify_init(). Since the
1493 * error cause code for "unknown parameter" and the
1494 * "Unrecognized parameter" type is the same, we can
1495 * construct the parameters in INIT ACK by copying the
1496 * ERROR causes over.
1497 */
1498 unk_param = (sctp_unrecognized_param_t *)
1499 ((__u8 *)(err_chunk->chunk_hdr) +
1500 sizeof(sctp_chunkhdr_t));
1501 /* Replace the cause code with the "Unrecognized parameter"
1502 * parameter type.
1503 */
1504 sctp_addto_chunk(repl, len, unk_param);
1505 }
1506
1507 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
1508 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1509
1510 /*
1511 * Note: After sending out INIT ACK with the State Cookie parameter,
1512 * "Z" MUST NOT allocate any resources for this new association.
1513 * Otherwise, "Z" will be vulnerable to resource attacks.
1514 */
1515 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
1516 retval = SCTP_DISPOSITION_CONSUME;
1517
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001518 return retval;
1519
1520nomem:
1521 retval = SCTP_DISPOSITION_NOMEM;
1522nomem_retval:
1523 if (new_asoc)
1524 sctp_association_free(new_asoc);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001525cleanup:
1526 if (err_chunk)
1527 sctp_chunk_free(err_chunk);
1528 return retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001529}
1530
1531/*
1532 * Handle simultanous INIT.
1533 * This means we started an INIT and then we got an INIT request from
1534 * our peer.
1535 *
1536 * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B)
1537 * This usually indicates an initialization collision, i.e., each
1538 * endpoint is attempting, at about the same time, to establish an
1539 * association with the other endpoint.
1540 *
1541 * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an
1542 * endpoint MUST respond with an INIT ACK using the same parameters it
1543 * sent in its original INIT chunk (including its Verification Tag,
1544 * unchanged). These original parameters are combined with those from the
1545 * newly received INIT chunk. The endpoint shall also generate a State
1546 * Cookie with the INIT ACK. The endpoint uses the parameters sent in its
1547 * INIT to calculate the State Cookie.
1548 *
1549 * After that, the endpoint MUST NOT change its state, the T1-init
1550 * timer shall be left running and the corresponding TCB MUST NOT be
1551 * destroyed. The normal procedures for handling State Cookies when
1552 * a TCB exists will resolve the duplicate INITs to a single association.
1553 *
1554 * For an endpoint that is in the COOKIE-ECHOED state it MUST populate
1555 * its Tie-Tags with the Tag information of itself and its peer (see
1556 * section 5.2.2 for a description of the Tie-Tags).
1557 *
1558 * Verification Tag: Not explicit, but an INIT can not have a valid
1559 * verification tag, so we skip the check.
1560 *
1561 * Inputs
1562 * (endpoint, asoc, chunk)
1563 *
1564 * Outputs
1565 * (asoc, reply_msg, msg_up, timers, counters)
1566 *
1567 * The return value is the disposition of the chunk.
1568 */
1569sctp_disposition_t sctp_sf_do_5_2_1_siminit(const struct sctp_endpoint *ep,
1570 const struct sctp_association *asoc,
1571 const sctp_subtype_t type,
1572 void *arg,
1573 sctp_cmd_seq_t *commands)
1574{
1575 /* Call helper to do the real work for both simulataneous and
1576 * duplicate INIT chunk handling.
1577 */
1578 return sctp_sf_do_unexpected_init(ep, asoc, type, arg, commands);
1579}
1580
1581/*
1582 * Handle duplicated INIT messages. These are usually delayed
1583 * restransmissions.
1584 *
1585 * Section: 5.2.2 Unexpected INIT in States Other than CLOSED,
1586 * COOKIE-ECHOED and COOKIE-WAIT
1587 *
1588 * Unless otherwise stated, upon reception of an unexpected INIT for
1589 * this association, the endpoint shall generate an INIT ACK with a
1590 * State Cookie. In the outbound INIT ACK the endpoint MUST copy its
1591 * current Verification Tag and peer's Verification Tag into a reserved
1592 * place within the state cookie. We shall refer to these locations as
1593 * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet
1594 * containing this INIT ACK MUST carry a Verification Tag value equal to
1595 * the Initiation Tag found in the unexpected INIT. And the INIT ACK
1596 * MUST contain a new Initiation Tag (randomly generated see Section
1597 * 5.3.1). Other parameters for the endpoint SHOULD be copied from the
1598 * existing parameters of the association (e.g. number of outbound
1599 * streams) into the INIT ACK and cookie.
1600 *
1601 * After sending out the INIT ACK, the endpoint shall take no further
1602 * actions, i.e., the existing association, including its current state,
1603 * and the corresponding TCB MUST NOT be changed.
1604 *
1605 * Note: Only when a TCB exists and the association is not in a COOKIE-
1606 * WAIT state are the Tie-Tags populated. For a normal association INIT
1607 * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be
1608 * set to 0 (indicating that no previous TCB existed). The INIT ACK and
1609 * State Cookie are populated as specified in section 5.2.1.
1610 *
1611 * Verification Tag: Not specified, but an INIT has no way of knowing
1612 * what the verification tag could be, so we ignore it.
1613 *
1614 * Inputs
1615 * (endpoint, asoc, chunk)
1616 *
1617 * Outputs
1618 * (asoc, reply_msg, msg_up, timers, counters)
1619 *
1620 * The return value is the disposition of the chunk.
1621 */
1622sctp_disposition_t sctp_sf_do_5_2_2_dupinit(const struct sctp_endpoint *ep,
1623 const struct sctp_association *asoc,
1624 const sctp_subtype_t type,
1625 void *arg,
1626 sctp_cmd_seq_t *commands)
1627{
1628 /* Call helper to do the real work for both simulataneous and
1629 * duplicate INIT chunk handling.
1630 */
1631 return sctp_sf_do_unexpected_init(ep, asoc, type, arg, commands);
1632}
1633
1634
Vlad Yasevich610ab732007-01-15 19:18:30 -08001635/*
1636 * Unexpected INIT-ACK handler.
1637 *
1638 * Section 5.2.3
1639 * If an INIT ACK received by an endpoint in any state other than the
1640 * COOKIE-WAIT state, the endpoint should discard the INIT ACK chunk.
1641 * An unexpected INIT ACK usually indicates the processing of an old or
1642 * duplicated INIT chunk.
1643*/
1644sctp_disposition_t sctp_sf_do_5_2_3_initack(const struct sctp_endpoint *ep,
1645 const struct sctp_association *asoc,
1646 const sctp_subtype_t type,
1647 void *arg, sctp_cmd_seq_t *commands)
1648{
1649 /* Per the above section, we'll discard the chunk if we have an
1650 * endpoint. If this is an OOTB INIT-ACK, treat it as such.
1651 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001652 if (ep == sctp_sk((sctp_get_ctl_sock()))->ep)
Vlad Yasevich610ab732007-01-15 19:18:30 -08001653 return sctp_sf_ootb(ep, asoc, type, arg, commands);
1654 else
1655 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
1656}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001657
1658/* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A')
1659 *
1660 * Section 5.2.4
1661 * A) In this case, the peer may have restarted.
1662 */
1663static sctp_disposition_t sctp_sf_do_dupcook_a(const struct sctp_endpoint *ep,
1664 const struct sctp_association *asoc,
1665 struct sctp_chunk *chunk,
1666 sctp_cmd_seq_t *commands,
1667 struct sctp_association *new_asoc)
1668{
1669 sctp_init_chunk_t *peer_init;
1670 struct sctp_ulpevent *ev;
1671 struct sctp_chunk *repl;
1672 struct sctp_chunk *err;
1673 sctp_disposition_t disposition;
1674
1675 /* new_asoc is a brand-new association, so these are not yet
1676 * side effects--it is safe to run them here.
1677 */
1678 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1679
1680 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
1681 sctp_source(chunk), peer_init,
1682 GFP_ATOMIC))
1683 goto nomem;
1684
1685 /* Make sure no new addresses are being added during the
1686 * restart. Though this is a pretty complicated attack
1687 * since you'd have to get inside the cookie.
1688 */
1689 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk, commands)) {
1690 return SCTP_DISPOSITION_CONSUME;
1691 }
1692
1693 /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes
1694 * the peer has restarted (Action A), it MUST NOT setup a new
1695 * association but instead resend the SHUTDOWN ACK and send an ERROR
1696 * chunk with a "Cookie Received while Shutting Down" error cause to
1697 * its peer.
1698 */
1699 if (sctp_state(asoc, SHUTDOWN_ACK_SENT)) {
1700 disposition = sctp_sf_do_9_2_reshutack(ep, asoc,
1701 SCTP_ST_CHUNK(chunk->chunk_hdr->type),
1702 chunk, commands);
1703 if (SCTP_DISPOSITION_NOMEM == disposition)
1704 goto nomem;
1705
1706 err = sctp_make_op_error(asoc, chunk,
1707 SCTP_ERROR_COOKIE_IN_SHUTDOWN,
1708 NULL, 0);
1709 if (err)
1710 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1711 SCTP_CHUNK(err));
1712
1713 return SCTP_DISPOSITION_CONSUME;
1714 }
1715
1716 /* For now, fail any unsent/unacked data. Consider the optional
1717 * choice of resending of this data.
1718 */
1719 sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_OUTQUEUE, SCTP_NULL());
1720
Linus Torvalds1da177e2005-04-16 15:20:36 -07001721 repl = sctp_make_cookie_ack(new_asoc, chunk);
1722 if (!repl)
1723 goto nomem;
1724
Linus Torvalds1da177e2005-04-16 15:20:36 -07001725 /* Report association restart to upper layer. */
1726 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_RESTART, 0,
1727 new_asoc->c.sinit_num_ostreams,
1728 new_asoc->c.sinit_max_instreams,
Vlad Yasevicha5a35e72007-03-23 11:34:08 -07001729 NULL, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001730 if (!ev)
1731 goto nomem_ev;
1732
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001733 /* Update the content of current association. */
1734 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1735 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001736 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
1737 return SCTP_DISPOSITION_CONSUME;
1738
1739nomem_ev:
1740 sctp_chunk_free(repl);
1741nomem:
1742 return SCTP_DISPOSITION_NOMEM;
1743}
1744
1745/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B')
1746 *
1747 * Section 5.2.4
1748 * B) In this case, both sides may be attempting to start an association
1749 * at about the same time but the peer endpoint started its INIT
1750 * after responding to the local endpoint's INIT
1751 */
1752/* This case represents an initialization collision. */
1753static sctp_disposition_t sctp_sf_do_dupcook_b(const struct sctp_endpoint *ep,
1754 const struct sctp_association *asoc,
1755 struct sctp_chunk *chunk,
1756 sctp_cmd_seq_t *commands,
1757 struct sctp_association *new_asoc)
1758{
1759 sctp_init_chunk_t *peer_init;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001760 struct sctp_chunk *repl;
1761
1762 /* new_asoc is a brand-new association, so these are not yet
1763 * side effects--it is safe to run them here.
1764 */
1765 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1766 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
1767 sctp_source(chunk), peer_init,
1768 GFP_ATOMIC))
1769 goto nomem;
1770
1771 /* Update the content of current association. */
1772 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1773 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1774 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1775 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
1776 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
1777
1778 repl = sctp_make_cookie_ack(new_asoc, chunk);
1779 if (!repl)
1780 goto nomem;
1781
1782 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001783
1784 /* RFC 2960 5.1 Normal Establishment of an Association
1785 *
1786 * D) IMPLEMENTATION NOTE: An implementation may choose to
1787 * send the Communication Up notification to the SCTP user
1788 * upon reception of a valid COOKIE ECHO chunk.
Vlad Yasevich07d93962007-05-04 13:55:27 -07001789 *
1790 * Sadly, this needs to be implemented as a side-effect, because
1791 * we are not guaranteed to have set the association id of the real
1792 * association and so these notifications need to be delayed until
1793 * the association id is allocated.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001794 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001795
Vlad Yasevich07d93962007-05-04 13:55:27 -07001796 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_CHANGE, SCTP_U8(SCTP_COMM_UP));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001797
1798 /* Sockets API Draft Section 5.3.1.6
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -08001799 * When a peer sends a Adaptation Layer Indication parameter , SCTP
Linus Torvalds1da177e2005-04-16 15:20:36 -07001800 * delivers this notification to inform the application that of the
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -08001801 * peers requested adaptation layer.
Vlad Yasevich07d93962007-05-04 13:55:27 -07001802 *
1803 * This also needs to be done as a side effect for the same reason as
1804 * above.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001805 */
Vlad Yasevich07d93962007-05-04 13:55:27 -07001806 if (asoc->peer.adaptation_ind)
1807 sctp_add_cmd_sf(commands, SCTP_CMD_ADAPTATION_IND, SCTP_NULL());
Linus Torvalds1da177e2005-04-16 15:20:36 -07001808
1809 return SCTP_DISPOSITION_CONSUME;
1810
Linus Torvalds1da177e2005-04-16 15:20:36 -07001811nomem:
1812 return SCTP_DISPOSITION_NOMEM;
1813}
1814
1815/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C')
1816 *
1817 * Section 5.2.4
1818 * C) In this case, the local endpoint's cookie has arrived late.
1819 * Before it arrived, the local endpoint sent an INIT and received an
1820 * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag
1821 * but a new tag of its own.
1822 */
1823/* This case represents an initialization collision. */
1824static sctp_disposition_t sctp_sf_do_dupcook_c(const struct sctp_endpoint *ep,
1825 const struct sctp_association *asoc,
1826 struct sctp_chunk *chunk,
1827 sctp_cmd_seq_t *commands,
1828 struct sctp_association *new_asoc)
1829{
1830 /* The cookie should be silently discarded.
1831 * The endpoint SHOULD NOT change states and should leave
1832 * any timers running.
1833 */
1834 return SCTP_DISPOSITION_DISCARD;
1835}
1836
1837/* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D')
1838 *
1839 * Section 5.2.4
1840 *
1841 * D) When both local and remote tags match the endpoint should always
1842 * enter the ESTABLISHED state, if it has not already done so.
1843 */
1844/* This case represents an initialization collision. */
1845static sctp_disposition_t sctp_sf_do_dupcook_d(const struct sctp_endpoint *ep,
1846 const struct sctp_association *asoc,
1847 struct sctp_chunk *chunk,
1848 sctp_cmd_seq_t *commands,
1849 struct sctp_association *new_asoc)
1850{
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001851 struct sctp_ulpevent *ev = NULL, *ai_ev = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001852 struct sctp_chunk *repl;
1853
1854 /* Clarification from Implementor's Guide:
1855 * D) When both local and remote tags match the endpoint should
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001856 * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state.
1857 * It should stop any cookie timer that may be running and send
1858 * a COOKIE ACK.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001859 */
1860
1861 /* Don't accidentally move back into established state. */
1862 if (asoc->state < SCTP_STATE_ESTABLISHED) {
1863 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1864 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1865 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1866 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1867 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
1868 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START,
1869 SCTP_NULL());
1870
1871 /* RFC 2960 5.1 Normal Establishment of an Association
1872 *
1873 * D) IMPLEMENTATION NOTE: An implementation may choose
1874 * to send the Communication Up notification to the
1875 * SCTP user upon reception of a valid COOKIE
1876 * ECHO chunk.
1877 */
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001878 ev = sctp_ulpevent_make_assoc_change(asoc, 0,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001879 SCTP_COMM_UP, 0,
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001880 asoc->c.sinit_num_ostreams,
1881 asoc->c.sinit_max_instreams,
YOSHIFUJI Hideaki9cbcbf42007-07-19 10:44:50 +09001882 NULL, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001883 if (!ev)
1884 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001885
1886 /* Sockets API Draft Section 5.3.1.6
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -08001887 * When a peer sends a Adaptation Layer Indication parameter,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001888 * SCTP delivers this notification to inform the application
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -08001889 * that of the peers requested adaptation layer.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001890 */
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -08001891 if (asoc->peer.adaptation_ind) {
1892 ai_ev = sctp_ulpevent_make_adaptation_indication(asoc,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001893 GFP_ATOMIC);
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001894 if (!ai_ev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001895 goto nomem;
1896
Linus Torvalds1da177e2005-04-16 15:20:36 -07001897 }
1898 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001899
1900 repl = sctp_make_cookie_ack(new_asoc, chunk);
1901 if (!repl)
1902 goto nomem;
1903
Vlad Yasevich2e3216c2008-06-19 16:08:18 -07001904 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1905
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001906 if (ev)
1907 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1908 SCTP_ULPEVENT(ev));
1909 if (ai_ev)
1910 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1911 SCTP_ULPEVENT(ai_ev));
1912
Linus Torvalds1da177e2005-04-16 15:20:36 -07001913 return SCTP_DISPOSITION_CONSUME;
1914
1915nomem:
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001916 if (ai_ev)
1917 sctp_ulpevent_free(ai_ev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001918 if (ev)
1919 sctp_ulpevent_free(ev);
1920 return SCTP_DISPOSITION_NOMEM;
1921}
1922
1923/*
1924 * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying
1925 * chunk was retransmitted and then delayed in the network.
1926 *
1927 * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists
1928 *
1929 * Verification Tag: None. Do cookie validation.
1930 *
1931 * Inputs
1932 * (endpoint, asoc, chunk)
1933 *
1934 * Outputs
1935 * (asoc, reply_msg, msg_up, timers, counters)
1936 *
1937 * The return value is the disposition of the chunk.
1938 */
1939sctp_disposition_t sctp_sf_do_5_2_4_dupcook(const struct sctp_endpoint *ep,
1940 const struct sctp_association *asoc,
1941 const sctp_subtype_t type,
1942 void *arg,
1943 sctp_cmd_seq_t *commands)
1944{
1945 sctp_disposition_t retval;
1946 struct sctp_chunk *chunk = arg;
1947 struct sctp_association *new_asoc;
1948 int error = 0;
1949 char action;
1950 struct sctp_chunk *err_chk_p;
1951
1952 /* Make sure that the chunk has a valid length from the protocol
1953 * perspective. In this case check to make sure we have at least
1954 * enough for the chunk header. Cookie length verification is
1955 * done later.
1956 */
1957 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
1958 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1959 commands);
1960
1961 /* "Decode" the chunk. We have no optional parameters so we
1962 * are in good shape.
1963 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001964 chunk->subh.cookie_hdr = (struct sctp_signed_cookie *)chunk->skb->data;
Sridhar Samudrala62b08082006-05-05 17:04:43 -07001965 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
1966 sizeof(sctp_chunkhdr_t)))
1967 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001968
1969 /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
1970 * of a duplicate COOKIE ECHO match the Verification Tags of the
1971 * current association, consider the State Cookie valid even if
1972 * the lifespan is exceeded.
1973 */
1974 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
1975 &err_chk_p);
1976
1977 /* FIXME:
1978 * If the re-build failed, what is the proper error path
1979 * from here?
1980 *
1981 * [We should abort the association. --piggy]
1982 */
1983 if (!new_asoc) {
1984 /* FIXME: Several errors are possible. A bad cookie should
1985 * be silently discarded, but think about logging it too.
1986 */
1987 switch (error) {
1988 case -SCTP_IERROR_NOMEM:
1989 goto nomem;
1990
1991 case -SCTP_IERROR_STALE_COOKIE:
1992 sctp_send_stale_cookie_err(ep, asoc, chunk, commands,
1993 err_chk_p);
1994 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1995 case -SCTP_IERROR_BAD_SIG:
1996 default:
1997 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07001998 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001999 }
2000
2001 /* Compare the tie_tag in cookie with the verification tag of
2002 * current association.
2003 */
2004 action = sctp_tietags_compare(new_asoc, asoc);
2005
2006 switch (action) {
2007 case 'A': /* Association restart. */
2008 retval = sctp_sf_do_dupcook_a(ep, asoc, chunk, commands,
2009 new_asoc);
2010 break;
2011
2012 case 'B': /* Collision case B. */
2013 retval = sctp_sf_do_dupcook_b(ep, asoc, chunk, commands,
2014 new_asoc);
2015 break;
2016
2017 case 'C': /* Collision case C. */
2018 retval = sctp_sf_do_dupcook_c(ep, asoc, chunk, commands,
2019 new_asoc);
2020 break;
2021
2022 case 'D': /* Collision case D. */
2023 retval = sctp_sf_do_dupcook_d(ep, asoc, chunk, commands,
2024 new_asoc);
2025 break;
2026
2027 default: /* Discard packet for all others. */
2028 retval = sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2029 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07002030 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002031
2032 /* Delete the tempory new association. */
2033 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
2034 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
2035
2036 return retval;
2037
2038nomem:
2039 return SCTP_DISPOSITION_NOMEM;
2040}
2041
2042/*
2043 * Process an ABORT. (SHUTDOWN-PENDING state)
2044 *
2045 * See sctp_sf_do_9_1_abort().
2046 */
2047sctp_disposition_t sctp_sf_shutdown_pending_abort(
2048 const struct sctp_endpoint *ep,
2049 const struct sctp_association *asoc,
2050 const sctp_subtype_t type,
2051 void *arg,
2052 sctp_cmd_seq_t *commands)
2053{
2054 struct sctp_chunk *chunk = arg;
2055
2056 if (!sctp_vtag_verify_either(chunk, asoc))
2057 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2058
2059 /* Make sure that the ABORT chunk has a valid length.
2060 * Since this is an ABORT chunk, we have to discard it
2061 * because of the following text:
2062 * RFC 2960, Section 3.3.7
2063 * If an endpoint receives an ABORT with a format error or for an
2064 * association that doesn't exist, it MUST silently discard it.
2065 * Becasue the length is "invalid", we can't really discard just
2066 * as we do not know its true length. So, to be safe, discard the
2067 * packet.
2068 */
2069 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2070 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2071
Vlad Yasevich75205f42007-12-20 14:12:59 -08002072 /* ADD-IP: Special case for ABORT chunks
2073 * F4) One special consideration is that ABORT Chunks arriving
2074 * destined to the IP address being deleted MUST be
2075 * ignored (see Section 5.3.1 for further details).
2076 */
2077 if (SCTP_ADDR_DEL ==
2078 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2079 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
2080
Vlad Yasevich75205f42007-12-20 14:12:59 -08002081 return __sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002082}
2083
2084/*
2085 * Process an ABORT. (SHUTDOWN-SENT state)
2086 *
2087 * See sctp_sf_do_9_1_abort().
2088 */
2089sctp_disposition_t sctp_sf_shutdown_sent_abort(const struct sctp_endpoint *ep,
2090 const struct sctp_association *asoc,
2091 const sctp_subtype_t type,
2092 void *arg,
2093 sctp_cmd_seq_t *commands)
2094{
2095 struct sctp_chunk *chunk = arg;
2096
2097 if (!sctp_vtag_verify_either(chunk, asoc))
2098 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2099
2100 /* Make sure that the ABORT chunk has a valid length.
2101 * Since this is an ABORT chunk, we have to discard it
2102 * because of the following text:
2103 * RFC 2960, Section 3.3.7
2104 * If an endpoint receives an ABORT with a format error or for an
2105 * association that doesn't exist, it MUST silently discard it.
2106 * Becasue the length is "invalid", we can't really discard just
2107 * as we do not know its true length. So, to be safe, discard the
2108 * packet.
2109 */
2110 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2111 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2112
Vlad Yasevich75205f42007-12-20 14:12:59 -08002113 /* ADD-IP: Special case for ABORT chunks
2114 * F4) One special consideration is that ABORT Chunks arriving
2115 * destined to the IP address being deleted MUST be
2116 * ignored (see Section 5.3.1 for further details).
2117 */
2118 if (SCTP_ADDR_DEL ==
2119 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2120 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
2121
Linus Torvalds1da177e2005-04-16 15:20:36 -07002122 /* Stop the T2-shutdown timer. */
2123 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2124 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2125
2126 /* Stop the T5-shutdown guard timer. */
2127 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2128 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
2129
Vlad Yasevich75205f42007-12-20 14:12:59 -08002130 return __sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002131}
2132
2133/*
2134 * Process an ABORT. (SHUTDOWN-ACK-SENT state)
2135 *
2136 * See sctp_sf_do_9_1_abort().
2137 */
2138sctp_disposition_t sctp_sf_shutdown_ack_sent_abort(
2139 const struct sctp_endpoint *ep,
2140 const struct sctp_association *asoc,
2141 const sctp_subtype_t type,
2142 void *arg,
2143 sctp_cmd_seq_t *commands)
2144{
2145 /* The same T2 timer, so we should be able to use
2146 * common function with the SHUTDOWN-SENT state.
2147 */
2148 return sctp_sf_shutdown_sent_abort(ep, asoc, type, arg, commands);
2149}
2150
2151/*
2152 * Handle an Error received in COOKIE_ECHOED state.
2153 *
2154 * Only handle the error type of stale COOKIE Error, the other errors will
2155 * be ignored.
2156 *
2157 * Inputs
2158 * (endpoint, asoc, chunk)
2159 *
2160 * Outputs
2161 * (asoc, reply_msg, msg_up, timers, counters)
2162 *
2163 * The return value is the disposition of the chunk.
2164 */
2165sctp_disposition_t sctp_sf_cookie_echoed_err(const struct sctp_endpoint *ep,
2166 const struct sctp_association *asoc,
2167 const sctp_subtype_t type,
2168 void *arg,
2169 sctp_cmd_seq_t *commands)
2170{
2171 struct sctp_chunk *chunk = arg;
2172 sctp_errhdr_t *err;
2173
2174 if (!sctp_vtag_verify(chunk, asoc))
2175 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2176
2177 /* Make sure that the ERROR chunk has a valid length.
2178 * The parameter walking depends on this as well.
2179 */
2180 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
2181 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2182 commands);
2183
2184 /* Process the error here */
2185 /* FUTURE FIXME: When PR-SCTP related and other optional
2186 * parms are emitted, this will have to change to handle multiple
2187 * errors.
2188 */
2189 sctp_walk_errors(err, chunk->chunk_hdr) {
2190 if (SCTP_ERROR_STALE_COOKIE == err->cause)
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002191 return sctp_sf_do_5_2_6_stale(ep, asoc, type,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002192 arg, commands);
2193 }
2194
2195 /* It is possible to have malformed error causes, and that
2196 * will cause us to end the walk early. However, since
2197 * we are discarding the packet, there should be no adverse
2198 * affects.
2199 */
2200 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2201}
2202
2203/*
2204 * Handle a Stale COOKIE Error
2205 *
2206 * Section: 5.2.6 Handle Stale COOKIE Error
2207 * If the association is in the COOKIE-ECHOED state, the endpoint may elect
2208 * one of the following three alternatives.
2209 * ...
2210 * 3) Send a new INIT chunk to the endpoint, adding a Cookie
2211 * Preservative parameter requesting an extension to the lifetime of
2212 * the State Cookie. When calculating the time extension, an
2213 * implementation SHOULD use the RTT information measured based on the
2214 * previous COOKIE ECHO / ERROR exchange, and should add no more
2215 * than 1 second beyond the measured RTT, due to long State Cookie
2216 * lifetimes making the endpoint more subject to a replay attack.
2217 *
2218 * Verification Tag: Not explicit, but safe to ignore.
2219 *
2220 * Inputs
2221 * (endpoint, asoc, chunk)
2222 *
2223 * Outputs
2224 * (asoc, reply_msg, msg_up, timers, counters)
2225 *
2226 * The return value is the disposition of the chunk.
2227 */
2228static sctp_disposition_t sctp_sf_do_5_2_6_stale(const struct sctp_endpoint *ep,
2229 const struct sctp_association *asoc,
2230 const sctp_subtype_t type,
2231 void *arg,
2232 sctp_cmd_seq_t *commands)
2233{
2234 struct sctp_chunk *chunk = arg;
2235 time_t stale;
2236 sctp_cookie_preserve_param_t bht;
2237 sctp_errhdr_t *err;
2238 struct sctp_chunk *reply;
2239 struct sctp_bind_addr *bp;
Frank Filz3f7a87d2005-06-20 13:14:57 -07002240 int attempts = asoc->init_err_counter + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002241
Vlad Yasevich81845c22006-01-30 15:59:54 -08002242 if (attempts > asoc->max_init_attempts) {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002243 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
2244 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002245 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08002246 SCTP_PERR(SCTP_ERROR_STALE_COOKIE));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002247 return SCTP_DISPOSITION_DELETE_TCB;
2248 }
2249
2250 err = (sctp_errhdr_t *)(chunk->skb->data);
2251
2252 /* When calculating the time extension, an implementation
2253 * SHOULD use the RTT information measured based on the
2254 * previous COOKIE ECHO / ERROR exchange, and should add no
2255 * more than 1 second beyond the measured RTT, due to long
2256 * State Cookie lifetimes making the endpoint more subject to
2257 * a replay attack.
2258 * Measure of Staleness's unit is usec. (1/1000000 sec)
2259 * Suggested Cookie Life-span Increment's unit is msec.
2260 * (1/1000 sec)
2261 * In general, if you use the suggested cookie life, the value
2262 * found in the field of measure of staleness should be doubled
2263 * to give ample time to retransmit the new cookie and thus
2264 * yield a higher probability of success on the reattempt.
2265 */
Al Viro34bcca22006-11-20 17:27:15 -08002266 stale = ntohl(*(__be32 *)((u8 *)err + sizeof(sctp_errhdr_t)));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002267 stale = (stale * 2) / 1000;
2268
2269 bht.param_hdr.type = SCTP_PARAM_COOKIE_PRESERVATIVE;
2270 bht.param_hdr.length = htons(sizeof(bht));
2271 bht.lifespan_increment = htonl(stale);
2272
2273 /* Build that new INIT chunk. */
2274 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
2275 reply = sctp_make_init(asoc, bp, GFP_ATOMIC, sizeof(bht));
2276 if (!reply)
2277 goto nomem;
2278
2279 sctp_addto_chunk(reply, sizeof(bht), &bht);
2280
2281 /* Clear peer's init_tag cached in assoc as we are sending a new INIT */
2282 sctp_add_cmd_sf(commands, SCTP_CMD_CLEAR_INIT_TAG, SCTP_NULL());
2283
2284 /* Stop pending T3-rtx and heartbeat timers */
2285 sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
2286 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
2287
2288 /* Delete non-primary peer ip addresses since we are transitioning
2289 * back to the COOKIE-WAIT state
2290 */
2291 sctp_add_cmd_sf(commands, SCTP_CMD_DEL_NON_PRIMARY, SCTP_NULL());
2292
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002293 /* If we've sent any data bundled with COOKIE-ECHO we will need to
2294 * resend
Linus Torvalds1da177e2005-04-16 15:20:36 -07002295 */
Vlad Yasevichb6157d82007-10-24 15:59:16 -04002296 sctp_add_cmd_sf(commands, SCTP_CMD_T1_RETRAN,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002297 SCTP_TRANSPORT(asoc->peer.primary_path));
2298
2299 /* Cast away the const modifier, as we want to just
2300 * rerun it through as a sideffect.
2301 */
Frank Filz3f7a87d2005-06-20 13:14:57 -07002302 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_INC, SCTP_NULL());
Linus Torvalds1da177e2005-04-16 15:20:36 -07002303
2304 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2305 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
2306 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2307 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
2308 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
2309 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
2310
2311 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2312
2313 return SCTP_DISPOSITION_CONSUME;
2314
2315nomem:
2316 return SCTP_DISPOSITION_NOMEM;
2317}
2318
2319/*
2320 * Process an ABORT.
2321 *
2322 * Section: 9.1
2323 * After checking the Verification Tag, the receiving endpoint shall
2324 * remove the association from its record, and shall report the
2325 * termination to its upper layer.
2326 *
2327 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
2328 * B) Rules for packet carrying ABORT:
2329 *
2330 * - The endpoint shall always fill in the Verification Tag field of the
2331 * outbound packet with the destination endpoint's tag value if it
2332 * is known.
2333 *
2334 * - If the ABORT is sent in response to an OOTB packet, the endpoint
2335 * MUST follow the procedure described in Section 8.4.
2336 *
2337 * - The receiver MUST accept the packet if the Verification Tag
2338 * matches either its own tag, OR the tag of its peer. Otherwise, the
2339 * receiver MUST silently discard the packet and take no further
2340 * action.
2341 *
2342 * Inputs
2343 * (endpoint, asoc, chunk)
2344 *
2345 * Outputs
2346 * (asoc, reply_msg, msg_up, timers, counters)
2347 *
2348 * The return value is the disposition of the chunk.
2349 */
2350sctp_disposition_t sctp_sf_do_9_1_abort(const struct sctp_endpoint *ep,
2351 const struct sctp_association *asoc,
2352 const sctp_subtype_t type,
2353 void *arg,
2354 sctp_cmd_seq_t *commands)
2355{
2356 struct sctp_chunk *chunk = arg;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002357
2358 if (!sctp_vtag_verify_either(chunk, asoc))
2359 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2360
2361 /* Make sure that the ABORT chunk has a valid length.
2362 * Since this is an ABORT chunk, we have to discard it
2363 * because of the following text:
2364 * RFC 2960, Section 3.3.7
2365 * If an endpoint receives an ABORT with a format error or for an
2366 * association that doesn't exist, it MUST silently discard it.
2367 * Becasue the length is "invalid", we can't really discard just
2368 * as we do not know its true length. So, to be safe, discard the
2369 * packet.
2370 */
2371 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2372 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2373
Vlad Yasevich75205f42007-12-20 14:12:59 -08002374 /* ADD-IP: Special case for ABORT chunks
2375 * F4) One special consideration is that ABORT Chunks arriving
2376 * destined to the IP address being deleted MUST be
2377 * ignored (see Section 5.3.1 for further details).
2378 */
2379 if (SCTP_ADDR_DEL ==
2380 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2381 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
2382
2383 return __sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
2384}
2385
2386static sctp_disposition_t __sctp_sf_do_9_1_abort(const struct sctp_endpoint *ep,
2387 const struct sctp_association *asoc,
2388 const sctp_subtype_t type,
2389 void *arg,
2390 sctp_cmd_seq_t *commands)
2391{
2392 struct sctp_chunk *chunk = arg;
2393 unsigned len;
2394 __be16 error = SCTP_ERROR_NO_ERROR;
2395
Linus Torvalds1da177e2005-04-16 15:20:36 -07002396 /* See if we have an error cause code in the chunk. */
2397 len = ntohs(chunk->chunk_hdr->length);
2398 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
2399 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2400
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002401 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNRESET));
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002402 /* ASSOC_FAILED will DELETE_TCB. */
Al Viro5be291f2006-11-20 17:01:06 -08002403 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, SCTP_PERR(error));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002404 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
2405 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
2406
2407 return SCTP_DISPOSITION_ABORT;
2408}
2409
2410/*
2411 * Process an ABORT. (COOKIE-WAIT state)
2412 *
2413 * See sctp_sf_do_9_1_abort() above.
2414 */
2415sctp_disposition_t sctp_sf_cookie_wait_abort(const struct sctp_endpoint *ep,
2416 const struct sctp_association *asoc,
2417 const sctp_subtype_t type,
2418 void *arg,
2419 sctp_cmd_seq_t *commands)
2420{
2421 struct sctp_chunk *chunk = arg;
2422 unsigned len;
Al Virof94c0192006-11-20 17:00:25 -08002423 __be16 error = SCTP_ERROR_NO_ERROR;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002424
2425 if (!sctp_vtag_verify_either(chunk, asoc))
2426 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2427
2428 /* Make sure that the ABORT chunk has a valid length.
2429 * Since this is an ABORT chunk, we have to discard it
2430 * because of the following text:
2431 * RFC 2960, Section 3.3.7
2432 * If an endpoint receives an ABORT with a format error or for an
2433 * association that doesn't exist, it MUST silently discard it.
2434 * Becasue the length is "invalid", we can't really discard just
2435 * as we do not know its true length. So, to be safe, discard the
2436 * packet.
2437 */
2438 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2439 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2440
2441 /* See if we have an error cause code in the chunk. */
2442 len = ntohs(chunk->chunk_hdr->length);
2443 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
2444 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2445
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002446 return sctp_stop_t1_and_abort(commands, error, ECONNREFUSED, asoc,
2447 chunk->transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002448}
2449
2450/*
2451 * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state)
2452 */
2453sctp_disposition_t sctp_sf_cookie_wait_icmp_abort(const struct sctp_endpoint *ep,
2454 const struct sctp_association *asoc,
2455 const sctp_subtype_t type,
2456 void *arg,
2457 sctp_cmd_seq_t *commands)
2458{
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002459 return sctp_stop_t1_and_abort(commands, SCTP_ERROR_NO_ERROR,
2460 ENOPROTOOPT, asoc,
Frank Filz3f7a87d2005-06-20 13:14:57 -07002461 (struct sctp_transport *)arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002462}
2463
2464/*
2465 * Process an ABORT. (COOKIE-ECHOED state)
2466 */
2467sctp_disposition_t sctp_sf_cookie_echoed_abort(const struct sctp_endpoint *ep,
2468 const struct sctp_association *asoc,
2469 const sctp_subtype_t type,
2470 void *arg,
2471 sctp_cmd_seq_t *commands)
2472{
2473 /* There is a single T1 timer, so we should be able to use
2474 * common function with the COOKIE-WAIT state.
2475 */
2476 return sctp_sf_cookie_wait_abort(ep, asoc, type, arg, commands);
2477}
2478
2479/*
2480 * Stop T1 timer and abort association with "INIT failed".
2481 *
2482 * This is common code called by several sctp_sf_*_abort() functions above.
2483 */
Adrian Bunk52c1da32005-06-23 22:05:33 -07002484static sctp_disposition_t sctp_stop_t1_and_abort(sctp_cmd_seq_t *commands,
Al Virof94c0192006-11-20 17:00:25 -08002485 __be16 error, int sk_err,
Frank Filz3f7a87d2005-06-20 13:14:57 -07002486 const struct sctp_association *asoc,
2487 struct sctp_transport *transport)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002488{
Frank Filz3f7a87d2005-06-20 13:14:57 -07002489 SCTP_DEBUG_PRINTK("ABORT received (INIT).\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07002490 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2491 SCTP_STATE(SCTP_STATE_CLOSED));
2492 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
2493 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2494 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002495 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(sk_err));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002496 /* CMD_INIT_FAILED will DELETE_TCB. */
2497 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08002498 SCTP_PERR(error));
Frank Filz3f7a87d2005-06-20 13:14:57 -07002499 return SCTP_DISPOSITION_ABORT;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002500}
2501
2502/*
2503 * sctp_sf_do_9_2_shut
2504 *
2505 * Section: 9.2
2506 * Upon the reception of the SHUTDOWN, the peer endpoint shall
2507 * - enter the SHUTDOWN-RECEIVED state,
2508 *
2509 * - stop accepting new data from its SCTP user
2510 *
2511 * - verify, by checking the Cumulative TSN Ack field of the chunk,
2512 * that all its outstanding DATA chunks have been received by the
2513 * SHUTDOWN sender.
2514 *
2515 * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT
2516 * send a SHUTDOWN in response to a ULP request. And should discard
2517 * subsequent SHUTDOWN chunks.
2518 *
2519 * If there are still outstanding DATA chunks left, the SHUTDOWN
2520 * receiver shall continue to follow normal data transmission
2521 * procedures defined in Section 6 until all outstanding DATA chunks
2522 * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept
2523 * new data from its SCTP user.
2524 *
2525 * Verification Tag: 8.5 Verification Tag [Normal verification]
2526 *
2527 * Inputs
2528 * (endpoint, asoc, chunk)
2529 *
2530 * Outputs
2531 * (asoc, reply_msg, msg_up, timers, counters)
2532 *
2533 * The return value is the disposition of the chunk.
2534 */
2535sctp_disposition_t sctp_sf_do_9_2_shutdown(const struct sctp_endpoint *ep,
2536 const struct sctp_association *asoc,
2537 const sctp_subtype_t type,
2538 void *arg,
2539 sctp_cmd_seq_t *commands)
2540{
2541 struct sctp_chunk *chunk = arg;
2542 sctp_shutdownhdr_t *sdh;
2543 sctp_disposition_t disposition;
2544 struct sctp_ulpevent *ev;
Wei Yongjundf10eec2008-10-23 01:00:21 -07002545 __u32 ctsn;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002546
2547 if (!sctp_vtag_verify(chunk, asoc))
2548 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2549
2550 /* Make sure that the SHUTDOWN chunk has a valid length. */
2551 if (!sctp_chunk_length_valid(chunk,
2552 sizeof(struct sctp_shutdown_chunk_t)))
2553 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2554 commands);
2555
2556 /* Convert the elaborate header. */
2557 sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
2558 skb_pull(chunk->skb, sizeof(sctp_shutdownhdr_t));
2559 chunk->subh.shutdown_hdr = sdh;
Wei Yongjundf10eec2008-10-23 01:00:21 -07002560 ctsn = ntohl(sdh->cum_tsn_ack);
2561
2562 /* If Cumulative TSN Ack beyond the max tsn currently
2563 * send, terminating the association and respond to the
2564 * sender with an ABORT.
2565 */
2566 if (!TSN_lt(ctsn, asoc->next_tsn))
2567 return sctp_sf_violation_ctsn(ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002568
Sridhar Samudralaeb0e0072005-09-22 23:48:38 -07002569 /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT
2570 * When a peer sends a SHUTDOWN, SCTP delivers this notification to
2571 * inform the application that it should cease sending data.
2572 */
2573 ev = sctp_ulpevent_make_shutdown_event(asoc, 0, GFP_ATOMIC);
2574 if (!ev) {
2575 disposition = SCTP_DISPOSITION_NOMEM;
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002576 goto out;
Sridhar Samudralaeb0e0072005-09-22 23:48:38 -07002577 }
2578 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
2579
Linus Torvalds1da177e2005-04-16 15:20:36 -07002580 /* Upon the reception of the SHUTDOWN, the peer endpoint shall
2581 * - enter the SHUTDOWN-RECEIVED state,
2582 * - stop accepting new data from its SCTP user
2583 *
2584 * [This is implicit in the new state.]
2585 */
2586 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2587 SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED));
2588 disposition = SCTP_DISPOSITION_CONSUME;
2589
2590 if (sctp_outq_is_empty(&asoc->outqueue)) {
2591 disposition = sctp_sf_do_9_2_shutdown_ack(ep, asoc, type,
2592 arg, commands);
2593 }
2594
2595 if (SCTP_DISPOSITION_NOMEM == disposition)
2596 goto out;
2597
2598 /* - verify, by checking the Cumulative TSN Ack field of the
2599 * chunk, that all its outstanding DATA chunks have been
2600 * received by the SHUTDOWN sender.
2601 */
2602 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
Al Viro2178eda2006-11-20 17:26:53 -08002603 SCTP_BE32(chunk->subh.shutdown_hdr->cum_tsn_ack));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002604
Linus Torvalds1da177e2005-04-16 15:20:36 -07002605out:
2606 return disposition;
2607}
2608
Wei Yongjun2e3f92d2008-10-23 01:01:18 -07002609/*
2610 * sctp_sf_do_9_2_shut_ctsn
2611 *
2612 * Once an endpoint has reached the SHUTDOWN-RECEIVED state,
2613 * it MUST NOT send a SHUTDOWN in response to a ULP request.
2614 * The Cumulative TSN Ack of the received SHUTDOWN chunk
2615 * MUST be processed.
2616 */
2617sctp_disposition_t sctp_sf_do_9_2_shut_ctsn(const struct sctp_endpoint *ep,
2618 const struct sctp_association *asoc,
2619 const sctp_subtype_t type,
2620 void *arg,
2621 sctp_cmd_seq_t *commands)
2622{
2623 struct sctp_chunk *chunk = arg;
2624 sctp_shutdownhdr_t *sdh;
2625
2626 if (!sctp_vtag_verify(chunk, asoc))
2627 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2628
2629 /* Make sure that the SHUTDOWN chunk has a valid length. */
2630 if (!sctp_chunk_length_valid(chunk,
2631 sizeof(struct sctp_shutdown_chunk_t)))
2632 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2633 commands);
2634
2635 sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
2636
2637 /* If Cumulative TSN Ack beyond the max tsn currently
2638 * send, terminating the association and respond to the
2639 * sender with an ABORT.
2640 */
2641 if (!TSN_lt(ntohl(sdh->cum_tsn_ack), asoc->next_tsn))
2642 return sctp_sf_violation_ctsn(ep, asoc, type, arg, commands);
2643
2644 /* verify, by checking the Cumulative TSN Ack field of the
2645 * chunk, that all its outstanding DATA chunks have been
2646 * received by the SHUTDOWN sender.
2647 */
2648 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
2649 SCTP_BE32(sdh->cum_tsn_ack));
2650
2651 return SCTP_DISPOSITION_CONSUME;
2652}
2653
Linus Torvalds1da177e2005-04-16 15:20:36 -07002654/* RFC 2960 9.2
2655 * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk
2656 * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination
2657 * transport addresses (either in the IP addresses or in the INIT chunk)
2658 * that belong to this association, it should discard the INIT chunk and
2659 * retransmit the SHUTDOWN ACK chunk.
2660 */
2661sctp_disposition_t sctp_sf_do_9_2_reshutack(const struct sctp_endpoint *ep,
2662 const struct sctp_association *asoc,
2663 const sctp_subtype_t type,
2664 void *arg,
2665 sctp_cmd_seq_t *commands)
2666{
2667 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
2668 struct sctp_chunk *reply;
2669
Vlad Yasevichece25df2007-09-07 16:30:54 -04002670 /* Make sure that the chunk has a valid length */
2671 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
2672 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2673 commands);
2674
Linus Torvalds1da177e2005-04-16 15:20:36 -07002675 /* Since we are not going to really process this INIT, there
2676 * is no point in verifying chunk boundries. Just generate
2677 * the SHUTDOWN ACK.
2678 */
2679 reply = sctp_make_shutdown_ack(asoc, chunk);
2680 if (NULL == reply)
2681 goto nomem;
2682
2683 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
2684 * the T2-SHUTDOWN timer.
2685 */
2686 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
2687
2688 /* and restart the T2-shutdown timer. */
2689 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2690 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2691
2692 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2693
2694 return SCTP_DISPOSITION_CONSUME;
2695nomem:
2696 return SCTP_DISPOSITION_NOMEM;
2697}
2698
2699/*
2700 * sctp_sf_do_ecn_cwr
2701 *
2702 * Section: Appendix A: Explicit Congestion Notification
2703 *
2704 * CWR:
2705 *
2706 * RFC 2481 details a specific bit for a sender to send in the header of
2707 * its next outbound TCP segment to indicate to its peer that it has
2708 * reduced its congestion window. This is termed the CWR bit. For
2709 * SCTP the same indication is made by including the CWR chunk.
2710 * This chunk contains one data element, i.e. the TSN number that
2711 * was sent in the ECNE chunk. This element represents the lowest
2712 * TSN number in the datagram that was originally marked with the
2713 * CE bit.
2714 *
2715 * Verification Tag: 8.5 Verification Tag [Normal verification]
2716 * Inputs
2717 * (endpoint, asoc, chunk)
2718 *
2719 * Outputs
2720 * (asoc, reply_msg, msg_up, timers, counters)
2721 *
2722 * The return value is the disposition of the chunk.
2723 */
2724sctp_disposition_t sctp_sf_do_ecn_cwr(const struct sctp_endpoint *ep,
2725 const struct sctp_association *asoc,
2726 const sctp_subtype_t type,
2727 void *arg,
2728 sctp_cmd_seq_t *commands)
2729{
2730 sctp_cwrhdr_t *cwr;
2731 struct sctp_chunk *chunk = arg;
Al Viro34bcca22006-11-20 17:27:15 -08002732 u32 lowest_tsn;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002733
2734 if (!sctp_vtag_verify(chunk, asoc))
2735 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2736
2737 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2738 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2739 commands);
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002740
Linus Torvalds1da177e2005-04-16 15:20:36 -07002741 cwr = (sctp_cwrhdr_t *) chunk->skb->data;
2742 skb_pull(chunk->skb, sizeof(sctp_cwrhdr_t));
2743
Al Viro34bcca22006-11-20 17:27:15 -08002744 lowest_tsn = ntohl(cwr->lowest_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002745
2746 /* Does this CWR ack the last sent congestion notification? */
Al Viro34bcca22006-11-20 17:27:15 -08002747 if (TSN_lte(asoc->last_ecne_tsn, lowest_tsn)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002748 /* Stop sending ECNE. */
2749 sctp_add_cmd_sf(commands,
2750 SCTP_CMD_ECN_CWR,
Al Viro34bcca22006-11-20 17:27:15 -08002751 SCTP_U32(lowest_tsn));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002752 }
2753 return SCTP_DISPOSITION_CONSUME;
2754}
2755
2756/*
2757 * sctp_sf_do_ecne
2758 *
2759 * Section: Appendix A: Explicit Congestion Notification
2760 *
2761 * ECN-Echo
2762 *
2763 * RFC 2481 details a specific bit for a receiver to send back in its
2764 * TCP acknowledgements to notify the sender of the Congestion
2765 * Experienced (CE) bit having arrived from the network. For SCTP this
2766 * same indication is made by including the ECNE chunk. This chunk
2767 * contains one data element, i.e. the lowest TSN associated with the IP
2768 * datagram marked with the CE bit.....
2769 *
2770 * Verification Tag: 8.5 Verification Tag [Normal verification]
2771 * Inputs
2772 * (endpoint, asoc, chunk)
2773 *
2774 * Outputs
2775 * (asoc, reply_msg, msg_up, timers, counters)
2776 *
2777 * The return value is the disposition of the chunk.
2778 */
2779sctp_disposition_t sctp_sf_do_ecne(const struct sctp_endpoint *ep,
2780 const struct sctp_association *asoc,
2781 const sctp_subtype_t type,
2782 void *arg,
2783 sctp_cmd_seq_t *commands)
2784{
2785 sctp_ecnehdr_t *ecne;
2786 struct sctp_chunk *chunk = arg;
2787
2788 if (!sctp_vtag_verify(chunk, asoc))
2789 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2790
2791 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2792 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2793 commands);
2794
2795 ecne = (sctp_ecnehdr_t *) chunk->skb->data;
2796 skb_pull(chunk->skb, sizeof(sctp_ecnehdr_t));
2797
2798 /* If this is a newer ECNE than the last CWR packet we sent out */
2799 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_ECNE,
2800 SCTP_U32(ntohl(ecne->lowest_tsn)));
2801
2802 return SCTP_DISPOSITION_CONSUME;
2803}
2804
2805/*
2806 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
2807 *
2808 * The SCTP endpoint MUST always acknowledge the reception of each valid
2809 * DATA chunk.
2810 *
2811 * The guidelines on delayed acknowledgement algorithm specified in
2812 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
2813 * acknowledgement SHOULD be generated for at least every second packet
2814 * (not every second DATA chunk) received, and SHOULD be generated within
2815 * 200 ms of the arrival of any unacknowledged DATA chunk. In some
2816 * situations it may be beneficial for an SCTP transmitter to be more
2817 * conservative than the algorithms detailed in this document allow.
2818 * However, an SCTP transmitter MUST NOT be more aggressive than the
2819 * following algorithms allow.
2820 *
2821 * A SCTP receiver MUST NOT generate more than one SACK for every
2822 * incoming packet, other than to update the offered window as the
2823 * receiving application consumes new data.
2824 *
2825 * Verification Tag: 8.5 Verification Tag [Normal verification]
2826 *
2827 * Inputs
2828 * (endpoint, asoc, chunk)
2829 *
2830 * Outputs
2831 * (asoc, reply_msg, msg_up, timers, counters)
2832 *
2833 * The return value is the disposition of the chunk.
2834 */
2835sctp_disposition_t sctp_sf_eat_data_6_2(const struct sctp_endpoint *ep,
2836 const struct sctp_association *asoc,
2837 const sctp_subtype_t type,
2838 void *arg,
2839 sctp_cmd_seq_t *commands)
2840{
2841 struct sctp_chunk *chunk = arg;
2842 int error;
2843
2844 if (!sctp_vtag_verify(chunk, asoc)) {
2845 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
2846 SCTP_NULL());
2847 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002848 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002849
2850 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
2851 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2852 commands);
2853
2854 error = sctp_eat_data(asoc, chunk, commands );
2855 switch (error) {
2856 case SCTP_IERROR_NO_ERROR:
2857 break;
2858 case SCTP_IERROR_HIGH_TSN:
2859 case SCTP_IERROR_BAD_STREAM:
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07002860 SCTP_INC_STATS(SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002861 goto discard_noforce;
2862 case SCTP_IERROR_DUP_TSN:
2863 case SCTP_IERROR_IGNORE_TSN:
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07002864 SCTP_INC_STATS(SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002865 goto discard_force;
2866 case SCTP_IERROR_NO_DATA:
2867 goto consume;
2868 default:
2869 BUG();
2870 }
2871
2872 if (asoc->autoclose) {
2873 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2874 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
2875 }
2876
2877 /* If this is the last chunk in a packet, we need to count it
2878 * toward sack generation. Note that we need to SACK every
2879 * OTHER packet containing data chunks, EVEN IF WE DISCARD
2880 * THEM. We elect to NOT generate SACK's if the chunk fails
2881 * the verification tag test.
2882 *
2883 * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2884 *
2885 * The SCTP endpoint MUST always acknowledge the reception of
2886 * each valid DATA chunk.
2887 *
2888 * The guidelines on delayed acknowledgement algorithm
2889 * specified in Section 4.2 of [RFC2581] SHOULD be followed.
2890 * Specifically, an acknowledgement SHOULD be generated for at
2891 * least every second packet (not every second DATA chunk)
2892 * received, and SHOULD be generated within 200 ms of the
2893 * arrival of any unacknowledged DATA chunk. In some
2894 * situations it may be beneficial for an SCTP transmitter to
2895 * be more conservative than the algorithms detailed in this
2896 * document allow. However, an SCTP transmitter MUST NOT be
2897 * more aggressive than the following algorithms allow.
2898 */
Frank Filz52ccb8e2005-12-22 11:36:46 -08002899 if (chunk->end_of_packet)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002900 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
2901
Linus Torvalds1da177e2005-04-16 15:20:36 -07002902 return SCTP_DISPOSITION_CONSUME;
2903
2904discard_force:
2905 /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2906 *
2907 * When a packet arrives with duplicate DATA chunk(s) and with
2908 * no new DATA chunk(s), the endpoint MUST immediately send a
2909 * SACK with no delay. If a packet arrives with duplicate
2910 * DATA chunk(s) bundled with new DATA chunks, the endpoint
2911 * MAY immediately send a SACK. Normally receipt of duplicate
2912 * DATA chunks will occur when the original SACK chunk was lost
2913 * and the peer's RTO has expired. The duplicate TSN number(s)
2914 * SHOULD be reported in the SACK as duplicate.
2915 */
2916 /* In our case, we split the MAY SACK advice up whether or not
2917 * the last chunk is a duplicate.'
2918 */
2919 if (chunk->end_of_packet)
2920 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
2921 return SCTP_DISPOSITION_DISCARD;
2922
2923discard_noforce:
Frank Filz52ccb8e2005-12-22 11:36:46 -08002924 if (chunk->end_of_packet)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002925 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
2926
Linus Torvalds1da177e2005-04-16 15:20:36 -07002927 return SCTP_DISPOSITION_DISCARD;
2928consume:
2929 return SCTP_DISPOSITION_CONSUME;
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002930
Linus Torvalds1da177e2005-04-16 15:20:36 -07002931}
2932
2933/*
2934 * sctp_sf_eat_data_fast_4_4
2935 *
2936 * Section: 4 (4)
2937 * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received
2938 * DATA chunks without delay.
2939 *
2940 * Verification Tag: 8.5 Verification Tag [Normal verification]
2941 * Inputs
2942 * (endpoint, asoc, chunk)
2943 *
2944 * Outputs
2945 * (asoc, reply_msg, msg_up, timers, counters)
2946 *
2947 * The return value is the disposition of the chunk.
2948 */
2949sctp_disposition_t sctp_sf_eat_data_fast_4_4(const struct sctp_endpoint *ep,
2950 const struct sctp_association *asoc,
2951 const sctp_subtype_t type,
2952 void *arg,
2953 sctp_cmd_seq_t *commands)
2954{
2955 struct sctp_chunk *chunk = arg;
2956 int error;
2957
2958 if (!sctp_vtag_verify(chunk, asoc)) {
2959 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
2960 SCTP_NULL());
2961 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2962 }
2963
2964 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
2965 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2966 commands);
2967
2968 error = sctp_eat_data(asoc, chunk, commands );
2969 switch (error) {
2970 case SCTP_IERROR_NO_ERROR:
2971 case SCTP_IERROR_HIGH_TSN:
2972 case SCTP_IERROR_DUP_TSN:
2973 case SCTP_IERROR_IGNORE_TSN:
2974 case SCTP_IERROR_BAD_STREAM:
2975 break;
2976 case SCTP_IERROR_NO_DATA:
2977 goto consume;
2978 default:
2979 BUG();
2980 }
2981
2982 /* Go a head and force a SACK, since we are shutting down. */
2983
2984 /* Implementor's Guide.
2985 *
2986 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
2987 * respond to each received packet containing one or more DATA chunk(s)
2988 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
2989 */
2990 if (chunk->end_of_packet) {
2991 /* We must delay the chunk creation since the cumulative
2992 * TSN has not been updated yet.
2993 */
2994 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
2995 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
2996 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2997 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2998 }
2999
3000consume:
3001 return SCTP_DISPOSITION_CONSUME;
3002}
3003
3004/*
3005 * Section: 6.2 Processing a Received SACK
3006 * D) Any time a SACK arrives, the endpoint performs the following:
3007 *
3008 * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point,
3009 * then drop the SACK. Since Cumulative TSN Ack is monotonically
3010 * increasing, a SACK whose Cumulative TSN Ack is less than the
3011 * Cumulative TSN Ack Point indicates an out-of-order SACK.
3012 *
3013 * ii) Set rwnd equal to the newly received a_rwnd minus the number
3014 * of bytes still outstanding after processing the Cumulative TSN Ack
3015 * and the Gap Ack Blocks.
3016 *
3017 * iii) If the SACK is missing a TSN that was previously
3018 * acknowledged via a Gap Ack Block (e.g., the data receiver
3019 * reneged on the data), then mark the corresponding DATA chunk
3020 * as available for retransmit: Mark it as missing for fast
3021 * retransmit as described in Section 7.2.4 and if no retransmit
3022 * timer is running for the destination address to which the DATA
3023 * chunk was originally transmitted, then T3-rtx is started for
3024 * that destination address.
3025 *
3026 * Verification Tag: 8.5 Verification Tag [Normal verification]
3027 *
3028 * Inputs
3029 * (endpoint, asoc, chunk)
3030 *
3031 * Outputs
3032 * (asoc, reply_msg, msg_up, timers, counters)
3033 *
3034 * The return value is the disposition of the chunk.
3035 */
3036sctp_disposition_t sctp_sf_eat_sack_6_2(const struct sctp_endpoint *ep,
3037 const struct sctp_association *asoc,
3038 const sctp_subtype_t type,
3039 void *arg,
3040 sctp_cmd_seq_t *commands)
3041{
3042 struct sctp_chunk *chunk = arg;
3043 sctp_sackhdr_t *sackh;
3044 __u32 ctsn;
3045
3046 if (!sctp_vtag_verify(chunk, asoc))
3047 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3048
3049 /* Make sure that the SACK chunk has a valid length. */
3050 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_sack_chunk_t)))
3051 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3052 commands);
3053
3054 /* Pull the SACK chunk from the data buffer */
3055 sackh = sctp_sm_pull_sack(chunk);
3056 /* Was this a bogus SACK? */
3057 if (!sackh)
3058 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3059 chunk->subh.sack_hdr = sackh;
3060 ctsn = ntohl(sackh->cum_tsn_ack);
3061
3062 /* i) If Cumulative TSN Ack is less than the Cumulative TSN
3063 * Ack Point, then drop the SACK. Since Cumulative TSN
3064 * Ack is monotonically increasing, a SACK whose
3065 * Cumulative TSN Ack is less than the Cumulative TSN Ack
3066 * Point indicates an out-of-order SACK.
3067 */
3068 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
3069 SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn);
3070 SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc->ctsn_ack_point);
3071 return SCTP_DISPOSITION_DISCARD;
3072 }
3073
Wei Yongjunaecedea2007-08-02 16:57:44 +08003074 /* If Cumulative TSN Ack beyond the max tsn currently
3075 * send, terminating the association and respond to the
3076 * sender with an ABORT.
3077 */
3078 if (!TSN_lt(ctsn, asoc->next_tsn))
3079 return sctp_sf_violation_ctsn(ep, asoc, type, arg, commands);
3080
Linus Torvalds1da177e2005-04-16 15:20:36 -07003081 /* Return this SACK for further processing. */
3082 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_SACKH(sackh));
3083
3084 /* Note: We do the rest of the work on the PROCESS_SACK
3085 * sideeffect.
3086 */
3087 return SCTP_DISPOSITION_CONSUME;
3088}
3089
3090/*
3091 * Generate an ABORT in response to a packet.
3092 *
Jerome Forissier047a2422005-04-28 11:58:43 -07003093 * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41
Linus Torvalds1da177e2005-04-16 15:20:36 -07003094 *
Jerome Forissier047a2422005-04-28 11:58:43 -07003095 * 8) The receiver should respond to the sender of the OOTB packet with
3096 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3097 * MUST fill in the Verification Tag field of the outbound packet
3098 * with the value found in the Verification Tag field of the OOTB
3099 * packet and set the T-bit in the Chunk Flags to indicate that the
3100 * Verification Tag is reflected. After sending this ABORT, the
3101 * receiver of the OOTB packet shall discard the OOTB packet and take
3102 * no further action.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003103 *
3104 * Verification Tag:
3105 *
3106 * The return value is the disposition of the chunk.
3107*/
Vlad Yasevichece25df2007-09-07 16:30:54 -04003108static sctp_disposition_t sctp_sf_tabort_8_4_8(const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003109 const struct sctp_association *asoc,
3110 const sctp_subtype_t type,
3111 void *arg,
3112 sctp_cmd_seq_t *commands)
3113{
3114 struct sctp_packet *packet = NULL;
3115 struct sctp_chunk *chunk = arg;
3116 struct sctp_chunk *abort;
3117
3118 packet = sctp_ootb_pkt_new(asoc, chunk);
3119
3120 if (packet) {
3121 /* Make an ABORT. The T bit will be set if the asoc
3122 * is NULL.
3123 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003124 abort = sctp_make_abort(asoc, chunk, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003125 if (!abort) {
3126 sctp_ootb_pkt_free(packet);
3127 return SCTP_DISPOSITION_NOMEM;
3128 }
3129
Jerome Forissier047a2422005-04-28 11:58:43 -07003130 /* Reflect vtag if T-Bit is set */
3131 if (sctp_test_T_bit(abort))
3132 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3133
Linus Torvalds1da177e2005-04-16 15:20:36 -07003134 /* Set the skb to the belonging sock for accounting. */
3135 abort->skb->sk = ep->base.sk;
3136
3137 sctp_packet_append_chunk(packet, abort);
3138
3139 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3140 SCTP_PACKET(packet));
3141
3142 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
3143
Vlad Yasevichd3f25962007-09-07 11:47:45 -04003144 sctp_sf_pdiscard(ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003145 return SCTP_DISPOSITION_CONSUME;
3146 }
3147
3148 return SCTP_DISPOSITION_NOMEM;
3149}
3150
3151/*
3152 * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR
3153 * event as ULP notification for each cause included in the chunk.
3154 *
3155 * API 5.3.1.3 - SCTP_REMOTE_ERROR
3156 *
3157 * The return value is the disposition of the chunk.
3158*/
3159sctp_disposition_t sctp_sf_operr_notify(const struct sctp_endpoint *ep,
3160 const struct sctp_association *asoc,
3161 const sctp_subtype_t type,
3162 void *arg,
3163 sctp_cmd_seq_t *commands)
3164{
3165 struct sctp_chunk *chunk = arg;
3166 struct sctp_ulpevent *ev;
3167
3168 if (!sctp_vtag_verify(chunk, asoc))
3169 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3170
3171 /* Make sure that the ERROR chunk has a valid length. */
3172 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
3173 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3174 commands);
3175
3176 while (chunk->chunk_end > chunk->skb->data) {
3177 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
3178 GFP_ATOMIC);
3179 if (!ev)
3180 goto nomem;
3181
Ilpo Järvinenbc09dff2008-03-27 17:54:29 -07003182 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
3183 SCTP_ULPEVENT(ev));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003184 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_OPERR,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003185 SCTP_CHUNK(chunk));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003186 }
3187 return SCTP_DISPOSITION_CONSUME;
3188
3189nomem:
3190 return SCTP_DISPOSITION_NOMEM;
3191}
3192
3193/*
3194 * Process an inbound SHUTDOWN ACK.
3195 *
3196 * From Section 9.2:
3197 * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3198 * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its
3199 * peer, and remove all record of the association.
3200 *
3201 * The return value is the disposition.
3202 */
3203sctp_disposition_t sctp_sf_do_9_2_final(const struct sctp_endpoint *ep,
3204 const struct sctp_association *asoc,
3205 const sctp_subtype_t type,
3206 void *arg,
3207 sctp_cmd_seq_t *commands)
3208{
3209 struct sctp_chunk *chunk = arg;
3210 struct sctp_chunk *reply;
3211 struct sctp_ulpevent *ev;
3212
3213 if (!sctp_vtag_verify(chunk, asoc))
3214 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3215
3216 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3217 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3218 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3219 commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003220 /* 10.2 H) SHUTDOWN COMPLETE notification
3221 *
3222 * When SCTP completes the shutdown procedures (section 9.2) this
3223 * notification is passed to the upper layer.
3224 */
3225 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
Vlad Yasevicha5a35e72007-03-23 11:34:08 -07003226 0, 0, 0, NULL, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003227 if (!ev)
3228 goto nomem;
3229
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07003230 /* ...send a SHUTDOWN COMPLETE chunk to its peer, */
3231 reply = sctp_make_shutdown_complete(asoc, chunk);
3232 if (!reply)
3233 goto nomem_chunk;
3234
3235 /* Do all the commands now (after allocation), so that we
3236 * have consistent state if memory allocation failes
3237 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003238 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
3239
3240 /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3241 * stop the T2-shutdown timer,
3242 */
3243 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3244 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3245
3246 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3247 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
3248
Linus Torvalds1da177e2005-04-16 15:20:36 -07003249 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3250 SCTP_STATE(SCTP_STATE_CLOSED));
3251 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
3252 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3253 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
3254
3255 /* ...and remove all record of the association. */
3256 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
3257 return SCTP_DISPOSITION_DELETE_TCB;
3258
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07003259nomem_chunk:
3260 sctp_ulpevent_free(ev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003261nomem:
3262 return SCTP_DISPOSITION_NOMEM;
3263}
3264
3265/*
Jerome Forissier047a2422005-04-28 11:58:43 -07003266 * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41.
3267 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003268 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3269 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3270 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3271 * packet must fill in the Verification Tag field of the outbound
3272 * packet with the Verification Tag received in the SHUTDOWN ACK and
Jerome Forissier047a2422005-04-28 11:58:43 -07003273 * set the T-bit in the Chunk Flags to indicate that the Verification
3274 * Tag is reflected.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003275 *
3276 * 8) The receiver should respond to the sender of the OOTB packet with
3277 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3278 * MUST fill in the Verification Tag field of the outbound packet
3279 * with the value found in the Verification Tag field of the OOTB
Jerome Forissier047a2422005-04-28 11:58:43 -07003280 * packet and set the T-bit in the Chunk Flags to indicate that the
3281 * Verification Tag is reflected. After sending this ABORT, the
3282 * receiver of the OOTB packet shall discard the OOTB packet and take
3283 * no further action.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003284 */
3285sctp_disposition_t sctp_sf_ootb(const struct sctp_endpoint *ep,
3286 const struct sctp_association *asoc,
3287 const sctp_subtype_t type,
3288 void *arg,
3289 sctp_cmd_seq_t *commands)
3290{
3291 struct sctp_chunk *chunk = arg;
3292 struct sk_buff *skb = chunk->skb;
3293 sctp_chunkhdr_t *ch;
3294 __u8 *ch_end;
3295 int ootb_shut_ack = 0;
3296
3297 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES);
3298
3299 ch = (sctp_chunkhdr_t *) chunk->chunk_hdr;
3300 do {
Vlad Yasevichece25df2007-09-07 16:30:54 -04003301 /* Report violation if the chunk is less then minimal */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003302 if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t))
Vlad Yasevichece25df2007-09-07 16:30:54 -04003303 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3304 commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003305
Vlad Yasevichece25df2007-09-07 16:30:54 -04003306 /* Now that we know we at least have a chunk header,
3307 * do things that are type appropriate.
3308 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003309 if (SCTP_CID_SHUTDOWN_ACK == ch->type)
3310 ootb_shut_ack = 1;
3311
3312 /* RFC 2960, Section 3.3.7
3313 * Moreover, under any circumstances, an endpoint that
3314 * receives an ABORT MUST NOT respond to that ABORT by
3315 * sending an ABORT of its own.
3316 */
3317 if (SCTP_CID_ABORT == ch->type)
3318 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003319
Vlad Yasevichece25df2007-09-07 16:30:54 -04003320 /* Report violation if chunk len overflows */
3321 ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
3322 if (ch_end > skb_tail_pointer(skb))
3323 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3324 commands);
3325
Linus Torvalds1da177e2005-04-16 15:20:36 -07003326 ch = (sctp_chunkhdr_t *) ch_end;
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07003327 } while (ch_end < skb_tail_pointer(skb));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003328
3329 if (ootb_shut_ack)
Vlad Yasevichd3f25962007-09-07 11:47:45 -04003330 return sctp_sf_shut_8_4_5(ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003331 else
Vlad Yasevichd3f25962007-09-07 11:47:45 -04003332 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003333}
3334
3335/*
3336 * Handle an "Out of the blue" SHUTDOWN ACK.
3337 *
Jerome Forissier047a2422005-04-28 11:58:43 -07003338 * Section: 8.4 5, sctpimpguide 2.41.
3339 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003340 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
Jerome Forissier047a2422005-04-28 11:58:43 -07003341 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3342 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3343 * packet must fill in the Verification Tag field of the outbound
3344 * packet with the Verification Tag received in the SHUTDOWN ACK and
3345 * set the T-bit in the Chunk Flags to indicate that the Verification
3346 * Tag is reflected.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003347 *
3348 * Inputs
3349 * (endpoint, asoc, type, arg, commands)
3350 *
3351 * Outputs
3352 * (sctp_disposition_t)
3353 *
3354 * The return value is the disposition of the chunk.
3355 */
3356static sctp_disposition_t sctp_sf_shut_8_4_5(const struct sctp_endpoint *ep,
3357 const struct sctp_association *asoc,
3358 const sctp_subtype_t type,
3359 void *arg,
3360 sctp_cmd_seq_t *commands)
3361{
3362 struct sctp_packet *packet = NULL;
3363 struct sctp_chunk *chunk = arg;
3364 struct sctp_chunk *shut;
3365
3366 packet = sctp_ootb_pkt_new(asoc, chunk);
3367
3368 if (packet) {
3369 /* Make an SHUTDOWN_COMPLETE.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003370 * The T bit will be set if the asoc is NULL.
3371 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003372 shut = sctp_make_shutdown_complete(asoc, chunk);
3373 if (!shut) {
3374 sctp_ootb_pkt_free(packet);
3375 return SCTP_DISPOSITION_NOMEM;
3376 }
3377
Jerome Forissier047a2422005-04-28 11:58:43 -07003378 /* Reflect vtag if T-Bit is set */
3379 if (sctp_test_T_bit(shut))
3380 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3381
Linus Torvalds1da177e2005-04-16 15:20:36 -07003382 /* Set the skb to the belonging sock for accounting. */
3383 shut->skb->sk = ep->base.sk;
3384
3385 sctp_packet_append_chunk(packet, shut);
3386
3387 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3388 SCTP_PACKET(packet));
3389
3390 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
3391
3392 /* If the chunk length is invalid, we don't want to process
3393 * the reset of the packet.
3394 */
3395 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3396 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3397
Vlad Yasevichd3f25962007-09-07 11:47:45 -04003398 /* We need to discard the rest of the packet to prevent
3399 * potential bomming attacks from additional bundled chunks.
3400 * This is documented in SCTP Threats ID.
3401 */
3402 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003403 }
3404
3405 return SCTP_DISPOSITION_NOMEM;
3406}
3407
3408/*
3409 * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state.
3410 *
3411 * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK
3412 * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the
3413 * procedures in section 8.4 SHOULD be followed, in other words it
3414 * should be treated as an Out Of The Blue packet.
3415 * [This means that we do NOT check the Verification Tag on these
3416 * chunks. --piggy ]
3417 *
3418 */
3419sctp_disposition_t sctp_sf_do_8_5_1_E_sa(const struct sctp_endpoint *ep,
3420 const struct sctp_association *asoc,
3421 const sctp_subtype_t type,
3422 void *arg,
3423 sctp_cmd_seq_t *commands)
3424{
Vlad Yasevichece25df2007-09-07 16:30:54 -04003425 struct sctp_chunk *chunk = arg;
3426
3427 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3428 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3429 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3430 commands);
3431
Linus Torvalds1da177e2005-04-16 15:20:36 -07003432 /* Although we do have an association in this case, it corresponds
3433 * to a restarted association. So the packet is treated as an OOTB
3434 * packet and the state function that handles OOTB SHUTDOWN_ACK is
3435 * called with a NULL association.
3436 */
Wei Yongjun8190f892008-09-08 12:13:55 +08003437 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES);
3438
Linus Torvalds1da177e2005-04-16 15:20:36 -07003439 return sctp_sf_shut_8_4_5(ep, NULL, type, arg, commands);
3440}
3441
3442/* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */
3443sctp_disposition_t sctp_sf_do_asconf(const struct sctp_endpoint *ep,
3444 const struct sctp_association *asoc,
3445 const sctp_subtype_t type, void *arg,
3446 sctp_cmd_seq_t *commands)
3447{
3448 struct sctp_chunk *chunk = arg;
3449 struct sctp_chunk *asconf_ack = NULL;
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003450 struct sctp_paramhdr *err_param = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003451 sctp_addiphdr_t *hdr;
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003452 union sctp_addr_param *addr_param;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003453 __u32 serial;
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003454 int length;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003455
3456 if (!sctp_vtag_verify(chunk, asoc)) {
3457 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3458 SCTP_NULL());
3459 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3460 }
3461
Vlad Yasevich6afd2e82007-12-20 14:08:04 -08003462 /* ADD-IP: Section 4.1.1
3463 * This chunk MUST be sent in an authenticated way by using
3464 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3465 * is received unauthenticated it MUST be silently discarded as
3466 * described in [I-D.ietf-tsvwg-sctp-auth].
3467 */
3468 if (!sctp_addip_noauth && !chunk->auth)
3469 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
3470
Linus Torvalds1da177e2005-04-16 15:20:36 -07003471 /* Make sure that the ASCONF ADDIP chunk has a valid length. */
3472 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_addip_chunk_t)))
3473 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3474 commands);
3475
3476 hdr = (sctp_addiphdr_t *)chunk->skb->data;
3477 serial = ntohl(hdr->serial);
3478
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003479 addr_param = (union sctp_addr_param *)hdr->params;
3480 length = ntohs(addr_param->p.length);
3481 if (length < sizeof(sctp_paramhdr_t))
Wei Yongjunba016672008-09-30 05:32:24 -07003482 return sctp_sf_violation_paramlen(ep, asoc, type, arg,
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003483 (void *)addr_param, commands);
3484
3485 /* Verify the ASCONF chunk before processing it. */
3486 if (!sctp_verify_asconf(asoc,
Vlad Yasevicha08de642007-12-20 14:11:47 -08003487 (sctp_paramhdr_t *)((void *)addr_param + length),
3488 (void *)chunk->chunk_end,
3489 &err_param))
Wei Yongjunba016672008-09-30 05:32:24 -07003490 return sctp_sf_violation_paramlen(ep, asoc, type, arg,
3491 (void *)err_param, commands);
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003492
Vlad Yasevicha08de642007-12-20 14:11:47 -08003493 /* ADDIP 5.2 E1) Compare the value of the serial number to the value
Linus Torvalds1da177e2005-04-16 15:20:36 -07003494 * the endpoint stored in a new association variable
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003495 * 'Peer-Serial-Number'.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003496 */
3497 if (serial == asoc->peer.addip_serial + 1) {
Vlad Yasevicha08de642007-12-20 14:11:47 -08003498 /* If this is the first instance of ASCONF in the packet,
3499 * we can clean our old ASCONF-ACKs.
3500 */
3501 if (!chunk->has_asconf)
3502 sctp_assoc_clean_asconf_ack_cache(asoc);
3503
3504 /* ADDIP 5.2 E4) When the Sequence Number matches the next one
3505 * expected, process the ASCONF as described below and after
3506 * processing the ASCONF Chunk, append an ASCONF-ACK Chunk to
3507 * the response packet and cache a copy of it (in the event it
3508 * later needs to be retransmitted).
3509 *
3510 * Essentially, do V1-V5.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003511 */
3512 asconf_ack = sctp_process_asconf((struct sctp_association *)
3513 asoc, chunk);
3514 if (!asconf_ack)
3515 return SCTP_DISPOSITION_NOMEM;
Vlad Yasevicha08de642007-12-20 14:11:47 -08003516 } else if (serial < asoc->peer.addip_serial + 1) {
3517 /* ADDIP 5.2 E2)
3518 * If the value found in the Sequence Number is less than the
3519 * ('Peer- Sequence-Number' + 1), simply skip to the next
3520 * ASCONF, and include in the outbound response packet
3521 * any previously cached ASCONF-ACK response that was
3522 * sent and saved that matches the Sequence Number of the
3523 * ASCONF. Note: It is possible that no cached ASCONF-ACK
3524 * Chunk exists. This will occur when an older ASCONF
3525 * arrives out of order. In such a case, the receiver
3526 * should skip the ASCONF Chunk and not include ASCONF-ACK
3527 * Chunk for that chunk.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003528 */
Vlad Yasevicha08de642007-12-20 14:11:47 -08003529 asconf_ack = sctp_assoc_lookup_asconf_ack(asoc, hdr->serial);
3530 if (!asconf_ack)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003531 return SCTP_DISPOSITION_DISCARD;
3532 } else {
Vlad Yasevicha08de642007-12-20 14:11:47 -08003533 /* ADDIP 5.2 E5) Otherwise, the ASCONF Chunk is discarded since
Linus Torvalds1da177e2005-04-16 15:20:36 -07003534 * it must be either a stale packet or from an attacker.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003535 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003536 return SCTP_DISPOSITION_DISCARD;
3537 }
3538
Vlad Yasevicha08de642007-12-20 14:11:47 -08003539 /* ADDIP 5.2 E6) The destination address of the SCTP packet
3540 * containing the ASCONF-ACK Chunks MUST be the source address of
3541 * the SCTP packet that held the ASCONF Chunks.
3542 *
3543 * To do this properly, we'll set the destination address of the chunk
3544 * and at the transmit time, will try look up the transport to use.
3545 * Since ASCONFs may be bundled, the correct transport may not be
3546 * created untill we process the entire packet, thus this workaround.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003547 */
Vlad Yasevicha08de642007-12-20 14:11:47 -08003548 asconf_ack->dest = chunk->source;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003549 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(asconf_ack));
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003550
Linus Torvalds1da177e2005-04-16 15:20:36 -07003551 return SCTP_DISPOSITION_CONSUME;
3552}
3553
3554/*
3555 * ADDIP Section 4.3 General rules for address manipulation
3556 * When building TLV parameters for the ASCONF Chunk that will add or
3557 * delete IP addresses the D0 to D13 rules should be applied:
3558 */
3559sctp_disposition_t sctp_sf_do_asconf_ack(const struct sctp_endpoint *ep,
3560 const struct sctp_association *asoc,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003561 const sctp_subtype_t type, void *arg,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003562 sctp_cmd_seq_t *commands)
3563{
3564 struct sctp_chunk *asconf_ack = arg;
3565 struct sctp_chunk *last_asconf = asoc->addip_last_asconf;
3566 struct sctp_chunk *abort;
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003567 struct sctp_paramhdr *err_param = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003568 sctp_addiphdr_t *addip_hdr;
3569 __u32 sent_serial, rcvd_serial;
3570
3571 if (!sctp_vtag_verify(asconf_ack, asoc)) {
3572 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3573 SCTP_NULL());
3574 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3575 }
3576
Vlad Yasevich6afd2e82007-12-20 14:08:04 -08003577 /* ADD-IP, Section 4.1.2:
3578 * This chunk MUST be sent in an authenticated way by using
3579 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3580 * is received unauthenticated it MUST be silently discarded as
3581 * described in [I-D.ietf-tsvwg-sctp-auth].
3582 */
3583 if (!sctp_addip_noauth && !asconf_ack->auth)
3584 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
3585
Linus Torvalds1da177e2005-04-16 15:20:36 -07003586 /* Make sure that the ADDIP chunk has a valid length. */
3587 if (!sctp_chunk_length_valid(asconf_ack, sizeof(sctp_addip_chunk_t)))
3588 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3589 commands);
3590
3591 addip_hdr = (sctp_addiphdr_t *)asconf_ack->skb->data;
3592 rcvd_serial = ntohl(addip_hdr->serial);
3593
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003594 /* Verify the ASCONF-ACK chunk before processing it. */
3595 if (!sctp_verify_asconf(asoc,
3596 (sctp_paramhdr_t *)addip_hdr->params,
3597 (void *)asconf_ack->chunk_end,
3598 &err_param))
Wei Yongjunba016672008-09-30 05:32:24 -07003599 return sctp_sf_violation_paramlen(ep, asoc, type, arg,
3600 (void *)err_param, commands);
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003601
Linus Torvalds1da177e2005-04-16 15:20:36 -07003602 if (last_asconf) {
3603 addip_hdr = (sctp_addiphdr_t *)last_asconf->subh.addip_hdr;
3604 sent_serial = ntohl(addip_hdr->serial);
3605 } else {
3606 sent_serial = asoc->addip_serial - 1;
3607 }
3608
3609 /* D0) If an endpoint receives an ASCONF-ACK that is greater than or
3610 * equal to the next serial number to be used but no ASCONF chunk is
3611 * outstanding the endpoint MUST ABORT the association. Note that a
3612 * sequence number is greater than if it is no more than 2^^31-1
3613 * larger than the current sequence number (using serial arithmetic).
3614 */
3615 if (ADDIP_SERIAL_gte(rcvd_serial, sent_serial + 1) &&
3616 !(asoc->addip_last_asconf)) {
3617 abort = sctp_make_abort(asoc, asconf_ack,
3618 sizeof(sctp_errhdr_t));
3619 if (abort) {
Wei Yongjun00f1c2d2007-08-21 15:50:01 +08003620 sctp_init_cause(abort, SCTP_ERROR_ASCONF_ACK, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003621 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3622 SCTP_CHUNK(abort));
3623 }
3624 /* We are going to ABORT, so we might as well stop
3625 * processing the rest of the chunks in the packet.
3626 */
3627 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3628 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3629 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07003630 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003631 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003632 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08003633 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003634 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
3635 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3636 return SCTP_DISPOSITION_ABORT;
3637 }
3638
3639 if ((rcvd_serial == sent_serial) && asoc->addip_last_asconf) {
3640 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3641 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3642
3643 if (!sctp_process_asconf_ack((struct sctp_association *)asoc,
3644 asconf_ack))
3645 return SCTP_DISPOSITION_CONSUME;
3646
3647 abort = sctp_make_abort(asoc, asconf_ack,
3648 sizeof(sctp_errhdr_t));
3649 if (abort) {
Wei Yongjun00f1c2d2007-08-21 15:50:01 +08003650 sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003651 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3652 SCTP_CHUNK(abort));
3653 }
3654 /* We are going to ABORT, so we might as well stop
3655 * processing the rest of the chunks in the packet.
3656 */
3657 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07003658 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003659 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003660 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08003661 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003662 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
3663 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3664 return SCTP_DISPOSITION_ABORT;
3665 }
3666
3667 return SCTP_DISPOSITION_DISCARD;
3668}
3669
3670/*
3671 * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP
3672 *
3673 * When a FORWARD TSN chunk arrives, the data receiver MUST first update
3674 * its cumulative TSN point to the value carried in the FORWARD TSN
3675 * chunk, and then MUST further advance its cumulative TSN point locally
3676 * if possible.
3677 * After the above processing, the data receiver MUST stop reporting any
3678 * missing TSNs earlier than or equal to the new cumulative TSN point.
3679 *
3680 * Verification Tag: 8.5 Verification Tag [Normal verification]
3681 *
3682 * The return value is the disposition of the chunk.
3683 */
3684sctp_disposition_t sctp_sf_eat_fwd_tsn(const struct sctp_endpoint *ep,
3685 const struct sctp_association *asoc,
3686 const sctp_subtype_t type,
3687 void *arg,
3688 sctp_cmd_seq_t *commands)
3689{
3690 struct sctp_chunk *chunk = arg;
3691 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
Wei Yongjun9fcb95a2008-12-25 16:58:11 -08003692 struct sctp_fwdtsn_skip *skip;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003693 __u16 len;
3694 __u32 tsn;
3695
3696 if (!sctp_vtag_verify(chunk, asoc)) {
3697 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3698 SCTP_NULL());
3699 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3700 }
3701
3702 /* Make sure that the FORWARD_TSN chunk has valid length. */
3703 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
3704 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3705 commands);
3706
3707 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3708 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3709 len = ntohs(chunk->chunk_hdr->length);
3710 len -= sizeof(struct sctp_chunkhdr);
3711 skb_pull(chunk->skb, len);
3712
3713 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
Harvey Harrison0dc47872008-03-05 20:47:47 -08003714 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __func__, tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003715
3716 /* The TSN is too high--silently discard the chunk and count on it
3717 * getting retransmitted later.
3718 */
3719 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3720 goto discard_noforce;
3721
Wei Yongjun9fcb95a2008-12-25 16:58:11 -08003722 /* Silently discard the chunk if stream-id is not valid */
3723 sctp_walk_fwdtsn(skip, chunk) {
3724 if (ntohs(skip->stream) >= asoc->c.sinit_max_instreams)
3725 goto discard_noforce;
3726 }
3727
Linus Torvalds1da177e2005-04-16 15:20:36 -07003728 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3729 if (len > sizeof(struct sctp_fwdtsn_hdr))
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003730 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003731 SCTP_CHUNK(chunk));
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003732
Linus Torvalds1da177e2005-04-16 15:20:36 -07003733 /* Count this as receiving DATA. */
3734 if (asoc->autoclose) {
3735 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3736 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
3737 }
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003738
Linus Torvalds1da177e2005-04-16 15:20:36 -07003739 /* FIXME: For now send a SACK, but DATA processing may
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003740 * send another.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003741 */
3742 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
Linus Torvalds1da177e2005-04-16 15:20:36 -07003743
3744 return SCTP_DISPOSITION_CONSUME;
3745
3746discard_noforce:
3747 return SCTP_DISPOSITION_DISCARD;
3748}
3749
3750sctp_disposition_t sctp_sf_eat_fwd_tsn_fast(
3751 const struct sctp_endpoint *ep,
3752 const struct sctp_association *asoc,
3753 const sctp_subtype_t type,
3754 void *arg,
3755 sctp_cmd_seq_t *commands)
3756{
3757 struct sctp_chunk *chunk = arg;
3758 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
Wei Yongjun9fcb95a2008-12-25 16:58:11 -08003759 struct sctp_fwdtsn_skip *skip;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003760 __u16 len;
3761 __u32 tsn;
3762
3763 if (!sctp_vtag_verify(chunk, asoc)) {
3764 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3765 SCTP_NULL());
3766 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3767 }
3768
3769 /* Make sure that the FORWARD_TSN chunk has a valid length. */
3770 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
3771 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3772 commands);
3773
3774 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3775 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3776 len = ntohs(chunk->chunk_hdr->length);
3777 len -= sizeof(struct sctp_chunkhdr);
3778 skb_pull(chunk->skb, len);
3779
3780 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
Harvey Harrison0dc47872008-03-05 20:47:47 -08003781 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __func__, tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003782
3783 /* The TSN is too high--silently discard the chunk and count on it
3784 * getting retransmitted later.
3785 */
3786 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3787 goto gen_shutdown;
3788
Wei Yongjun9fcb95a2008-12-25 16:58:11 -08003789 /* Silently discard the chunk if stream-id is not valid */
3790 sctp_walk_fwdtsn(skip, chunk) {
3791 if (ntohs(skip->stream) >= asoc->c.sinit_max_instreams)
3792 goto gen_shutdown;
3793 }
3794
Linus Torvalds1da177e2005-04-16 15:20:36 -07003795 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3796 if (len > sizeof(struct sctp_fwdtsn_hdr))
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003797 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003798 SCTP_CHUNK(chunk));
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003799
Linus Torvalds1da177e2005-04-16 15:20:36 -07003800 /* Go a head and force a SACK, since we are shutting down. */
3801gen_shutdown:
3802 /* Implementor's Guide.
3803 *
3804 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3805 * respond to each received packet containing one or more DATA chunk(s)
3806 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3807 */
3808 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
3809 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3810 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3811 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3812
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003813 return SCTP_DISPOSITION_CONSUME;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003814}
3815
3816/*
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07003817 * SCTP-AUTH Section 6.3 Receving authenticated chukns
3818 *
3819 * The receiver MUST use the HMAC algorithm indicated in the HMAC
3820 * Identifier field. If this algorithm was not specified by the
3821 * receiver in the HMAC-ALGO parameter in the INIT or INIT-ACK chunk
3822 * during association setup, the AUTH chunk and all chunks after it MUST
3823 * be discarded and an ERROR chunk SHOULD be sent with the error cause
3824 * defined in Section 4.1.
3825 *
3826 * If an endpoint with no shared key receives a Shared Key Identifier
3827 * other than 0, it MUST silently discard all authenticated chunks. If
3828 * the endpoint has at least one endpoint pair shared key for the peer,
3829 * it MUST use the key specified by the Shared Key Identifier if a
3830 * key has been configured for that Shared Key Identifier. If no
3831 * endpoint pair shared key has been configured for that Shared Key
3832 * Identifier, all authenticated chunks MUST be silently discarded.
3833 *
3834 * Verification Tag: 8.5 Verification Tag [Normal verification]
3835 *
3836 * The return value is the disposition of the chunk.
3837 */
3838static sctp_ierror_t sctp_sf_authenticate(const struct sctp_endpoint *ep,
3839 const struct sctp_association *asoc,
3840 const sctp_subtype_t type,
3841 struct sctp_chunk *chunk)
3842{
3843 struct sctp_authhdr *auth_hdr;
3844 struct sctp_hmac *hmac;
3845 unsigned int sig_len;
3846 __u16 key_id;
3847 __u8 *save_digest;
3848 __u8 *digest;
3849
3850 /* Pull in the auth header, so we can do some more verification */
3851 auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
3852 chunk->subh.auth_hdr = auth_hdr;
3853 skb_pull(chunk->skb, sizeof(struct sctp_authhdr));
3854
3855 /* Make sure that we suport the HMAC algorithm from the auth
3856 * chunk.
3857 */
3858 if (!sctp_auth_asoc_verify_hmac_id(asoc, auth_hdr->hmac_id))
3859 return SCTP_IERROR_AUTH_BAD_HMAC;
3860
3861 /* Make sure that the provided shared key identifier has been
3862 * configured
3863 */
3864 key_id = ntohs(auth_hdr->shkey_id);
3865 if (key_id != asoc->active_key_id && !sctp_auth_get_shkey(asoc, key_id))
3866 return SCTP_IERROR_AUTH_BAD_KEYID;
3867
3868
3869 /* Make sure that the length of the signature matches what
3870 * we expect.
3871 */
3872 sig_len = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_auth_chunk_t);
3873 hmac = sctp_auth_get_hmac(ntohs(auth_hdr->hmac_id));
3874 if (sig_len != hmac->hmac_len)
3875 return SCTP_IERROR_PROTO_VIOLATION;
3876
3877 /* Now that we've done validation checks, we can compute and
3878 * verify the hmac. The steps involved are:
3879 * 1. Save the digest from the chunk.
3880 * 2. Zero out the digest in the chunk.
3881 * 3. Compute the new digest
3882 * 4. Compare saved and new digests.
3883 */
3884 digest = auth_hdr->hmac;
3885 skb_pull(chunk->skb, sig_len);
3886
3887 save_digest = kmemdup(digest, sig_len, GFP_ATOMIC);
3888 if (!save_digest)
3889 goto nomem;
3890
3891 memset(digest, 0, sig_len);
3892
3893 sctp_auth_calculate_hmac(asoc, chunk->skb,
3894 (struct sctp_auth_chunk *)chunk->chunk_hdr,
3895 GFP_ATOMIC);
3896
3897 /* Discard the packet if the digests do not match */
3898 if (memcmp(save_digest, digest, sig_len)) {
3899 kfree(save_digest);
3900 return SCTP_IERROR_BAD_SIG;
3901 }
3902
3903 kfree(save_digest);
3904 chunk->auth = 1;
3905
3906 return SCTP_IERROR_NO_ERROR;
3907nomem:
3908 return SCTP_IERROR_NOMEM;
3909}
3910
3911sctp_disposition_t sctp_sf_eat_auth(const struct sctp_endpoint *ep,
3912 const struct sctp_association *asoc,
3913 const sctp_subtype_t type,
3914 void *arg,
3915 sctp_cmd_seq_t *commands)
3916{
3917 struct sctp_authhdr *auth_hdr;
3918 struct sctp_chunk *chunk = arg;
3919 struct sctp_chunk *err_chunk;
3920 sctp_ierror_t error;
3921
Wei Yongjund2f19fa2008-02-05 03:02:26 -08003922 /* Make sure that the peer has AUTH capable */
3923 if (!asoc->peer.auth_capable)
3924 return sctp_sf_unk_chunk(ep, asoc, type, arg, commands);
3925
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07003926 if (!sctp_vtag_verify(chunk, asoc)) {
3927 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3928 SCTP_NULL());
3929 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3930 }
3931
3932 /* Make sure that the AUTH chunk has valid length. */
3933 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_auth_chunk)))
3934 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3935 commands);
3936
3937 auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
3938 error = sctp_sf_authenticate(ep, asoc, type, chunk);
3939 switch (error) {
3940 case SCTP_IERROR_AUTH_BAD_HMAC:
3941 /* Generate the ERROR chunk and discard the rest
3942 * of the packet
3943 */
3944 err_chunk = sctp_make_op_error(asoc, chunk,
3945 SCTP_ERROR_UNSUP_HMAC,
3946 &auth_hdr->hmac_id,
3947 sizeof(__u16));
3948 if (err_chunk) {
3949 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3950 SCTP_CHUNK(err_chunk));
3951 }
3952 /* Fall Through */
3953 case SCTP_IERROR_AUTH_BAD_KEYID:
3954 case SCTP_IERROR_BAD_SIG:
3955 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3956 break;
3957 case SCTP_IERROR_PROTO_VIOLATION:
3958 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3959 commands);
3960 break;
3961 case SCTP_IERROR_NOMEM:
3962 return SCTP_DISPOSITION_NOMEM;
3963 default:
3964 break;
3965 }
3966
Vlad Yasevich65b07e52007-09-16 19:34:00 -07003967 if (asoc->active_key_id != ntohs(auth_hdr->shkey_id)) {
3968 struct sctp_ulpevent *ev;
3969
3970 ev = sctp_ulpevent_make_authkey(asoc, ntohs(auth_hdr->shkey_id),
3971 SCTP_AUTH_NEWKEY, GFP_ATOMIC);
3972
3973 if (!ev)
3974 return -ENOMEM;
3975
3976 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
3977 SCTP_ULPEVENT(ev));
3978 }
3979
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07003980 return SCTP_DISPOSITION_CONSUME;
3981}
3982
3983/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07003984 * Process an unknown chunk.
3985 *
3986 * Section: 3.2. Also, 2.1 in the implementor's guide.
3987 *
3988 * Chunk Types are encoded such that the highest-order two bits specify
3989 * the action that must be taken if the processing endpoint does not
3990 * recognize the Chunk Type.
3991 *
3992 * 00 - Stop processing this SCTP packet and discard it, do not process
3993 * any further chunks within it.
3994 *
3995 * 01 - Stop processing this SCTP packet and discard it, do not process
3996 * any further chunks within it, and report the unrecognized
3997 * chunk in an 'Unrecognized Chunk Type'.
3998 *
3999 * 10 - Skip this chunk and continue processing.
4000 *
4001 * 11 - Skip this chunk and continue processing, but report in an ERROR
4002 * Chunk using the 'Unrecognized Chunk Type' cause of error.
4003 *
4004 * The return value is the disposition of the chunk.
4005 */
4006sctp_disposition_t sctp_sf_unk_chunk(const struct sctp_endpoint *ep,
4007 const struct sctp_association *asoc,
4008 const sctp_subtype_t type,
4009 void *arg,
4010 sctp_cmd_seq_t *commands)
4011{
4012 struct sctp_chunk *unk_chunk = arg;
4013 struct sctp_chunk *err_chunk;
4014 sctp_chunkhdr_t *hdr;
4015
4016 SCTP_DEBUG_PRINTK("Processing the unknown chunk id %d.\n", type.chunk);
4017
4018 if (!sctp_vtag_verify(unk_chunk, asoc))
4019 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
4020
4021 /* Make sure that the chunk has a valid length.
4022 * Since we don't know the chunk type, we use a general
4023 * chunkhdr structure to make a comparison.
4024 */
4025 if (!sctp_chunk_length_valid(unk_chunk, sizeof(sctp_chunkhdr_t)))
4026 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
4027 commands);
4028
4029 switch (type.chunk & SCTP_CID_ACTION_MASK) {
4030 case SCTP_CID_ACTION_DISCARD:
4031 /* Discard the packet. */
4032 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
4033 break;
4034 case SCTP_CID_ACTION_DISCARD_ERR:
Linus Torvalds1da177e2005-04-16 15:20:36 -07004035 /* Generate an ERROR chunk as response. */
4036 hdr = unk_chunk->chunk_hdr;
4037 err_chunk = sctp_make_op_error(asoc, unk_chunk,
4038 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
4039 WORD_ROUND(ntohs(hdr->length)));
4040 if (err_chunk) {
4041 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4042 SCTP_CHUNK(err_chunk));
4043 }
Vlad Yasevich2e3216c2008-06-19 16:08:18 -07004044
4045 /* Discard the packet. */
4046 sctp_sf_pdiscard(ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004047 return SCTP_DISPOSITION_CONSUME;
4048 break;
4049 case SCTP_CID_ACTION_SKIP:
4050 /* Skip the chunk. */
4051 return SCTP_DISPOSITION_DISCARD;
4052 break;
4053 case SCTP_CID_ACTION_SKIP_ERR:
4054 /* Generate an ERROR chunk as response. */
4055 hdr = unk_chunk->chunk_hdr;
4056 err_chunk = sctp_make_op_error(asoc, unk_chunk,
4057 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
4058 WORD_ROUND(ntohs(hdr->length)));
4059 if (err_chunk) {
4060 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4061 SCTP_CHUNK(err_chunk));
4062 }
4063 /* Skip the chunk. */
4064 return SCTP_DISPOSITION_CONSUME;
4065 break;
4066 default:
4067 break;
4068 }
4069
4070 return SCTP_DISPOSITION_DISCARD;
4071}
4072
4073/*
4074 * Discard the chunk.
4075 *
4076 * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2
4077 * [Too numerous to mention...]
4078 * Verification Tag: No verification needed.
4079 * Inputs
4080 * (endpoint, asoc, chunk)
4081 *
4082 * Outputs
4083 * (asoc, reply_msg, msg_up, timers, counters)
4084 *
4085 * The return value is the disposition of the chunk.
4086 */
4087sctp_disposition_t sctp_sf_discard_chunk(const struct sctp_endpoint *ep,
4088 const struct sctp_association *asoc,
4089 const sctp_subtype_t type,
4090 void *arg,
4091 sctp_cmd_seq_t *commands)
4092{
Vlad Yasevichece25df2007-09-07 16:30:54 -04004093 struct sctp_chunk *chunk = arg;
4094
4095 /* Make sure that the chunk has a valid length.
4096 * Since we don't know the chunk type, we use a general
4097 * chunkhdr structure to make a comparison.
4098 */
4099 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
4100 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
4101 commands);
4102
Linus Torvalds1da177e2005-04-16 15:20:36 -07004103 SCTP_DEBUG_PRINTK("Chunk %d is discarded\n", type.chunk);
4104 return SCTP_DISPOSITION_DISCARD;
4105}
4106
4107/*
4108 * Discard the whole packet.
4109 *
4110 * Section: 8.4 2)
4111 *
4112 * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST
4113 * silently discard the OOTB packet and take no further action.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004114 *
4115 * Verification Tag: No verification necessary
4116 *
4117 * Inputs
4118 * (endpoint, asoc, chunk)
4119 *
4120 * Outputs
4121 * (asoc, reply_msg, msg_up, timers, counters)
4122 *
4123 * The return value is the disposition of the chunk.
4124 */
4125sctp_disposition_t sctp_sf_pdiscard(const struct sctp_endpoint *ep,
4126 const struct sctp_association *asoc,
4127 const sctp_subtype_t type,
4128 void *arg,
4129 sctp_cmd_seq_t *commands)
4130{
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07004131 SCTP_INC_STATS(SCTP_MIB_IN_PKT_DISCARDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004132 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
4133
4134 return SCTP_DISPOSITION_CONSUME;
4135}
4136
4137
4138/*
4139 * The other end is violating protocol.
4140 *
4141 * Section: Not specified
4142 * Verification Tag: Not specified
4143 * Inputs
4144 * (endpoint, asoc, chunk)
4145 *
4146 * Outputs
4147 * (asoc, reply_msg, msg_up, timers, counters)
4148 *
4149 * We simply tag the chunk as a violation. The state machine will log
4150 * the violation and continue.
4151 */
4152sctp_disposition_t sctp_sf_violation(const struct sctp_endpoint *ep,
4153 const struct sctp_association *asoc,
4154 const sctp_subtype_t type,
4155 void *arg,
4156 sctp_cmd_seq_t *commands)
4157{
Vlad Yasevichece25df2007-09-07 16:30:54 -04004158 struct sctp_chunk *chunk = arg;
4159
4160 /* Make sure that the chunk has a valid length. */
4161 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
4162 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
4163 commands);
4164
Linus Torvalds1da177e2005-04-16 15:20:36 -07004165 return SCTP_DISPOSITION_VIOLATION;
4166}
4167
Linus Torvalds1da177e2005-04-16 15:20:36 -07004168/*
Wei Yongjunaecedea2007-08-02 16:57:44 +08004169 * Common function to handle a protocol violation.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004170 */
Wei Yongjunaecedea2007-08-02 16:57:44 +08004171static sctp_disposition_t sctp_sf_abort_violation(
Vlad Yasevichece25df2007-09-07 16:30:54 -04004172 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07004173 const struct sctp_association *asoc,
Linus Torvalds1da177e2005-04-16 15:20:36 -07004174 void *arg,
Wei Yongjunaecedea2007-08-02 16:57:44 +08004175 sctp_cmd_seq_t *commands,
4176 const __u8 *payload,
4177 const size_t paylen)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004178{
Vlad Yasevichece25df2007-09-07 16:30:54 -04004179 struct sctp_packet *packet = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004180 struct sctp_chunk *chunk = arg;
4181 struct sctp_chunk *abort = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004182
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07004183 /* SCTP-AUTH, Section 6.3:
4184 * It should be noted that if the receiver wants to tear
4185 * down an association in an authenticated way only, the
4186 * handling of malformed packets should not result in
4187 * tearing down the association.
4188 *
4189 * This means that if we only want to abort associations
4190 * in an authenticated way (i.e AUTH+ABORT), then we
Oliver Pinterac461a02008-02-03 17:52:41 +02004191 * can't destroy this association just becuase the packet
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07004192 * was malformed.
4193 */
4194 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
4195 goto discard;
4196
Jesper Juhl9abed242007-11-11 23:57:49 +01004197 /* Make the abort chunk. */
4198 abort = sctp_make_abort_violation(asoc, chunk, payload, paylen);
4199 if (!abort)
4200 goto nomem;
4201
Vlad Yasevichece25df2007-09-07 16:30:54 -04004202 if (asoc) {
Gui Jianfengf4ad85c2008-04-12 18:39:34 -07004203 /* Treat INIT-ACK as a special case during COOKIE-WAIT. */
4204 if (chunk->chunk_hdr->type == SCTP_CID_INIT_ACK &&
4205 !asoc->peer.i.init_tag) {
4206 sctp_initack_chunk_t *initack;
4207
4208 initack = (sctp_initack_chunk_t *)chunk->chunk_hdr;
4209 if (!sctp_chunk_length_valid(chunk,
4210 sizeof(sctp_initack_chunk_t)))
4211 abort->chunk_hdr->flags |= SCTP_CHUNK_FLAG_T;
4212 else {
4213 unsigned int inittag;
4214
4215 inittag = ntohl(initack->init_hdr.init_tag);
4216 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_INITTAG,
4217 SCTP_U32(inittag));
4218 }
4219 }
4220
Vlad Yasevichece25df2007-09-07 16:30:54 -04004221 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4222 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004223
Vlad Yasevichece25df2007-09-07 16:30:54 -04004224 if (asoc->state <= SCTP_STATE_COOKIE_ECHOED) {
4225 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4226 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4227 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4228 SCTP_ERROR(ECONNREFUSED));
4229 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
4230 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4231 } else {
4232 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4233 SCTP_ERROR(ECONNABORTED));
4234 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4235 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4236 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
4237 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07004238 } else {
Vlad Yasevichece25df2007-09-07 16:30:54 -04004239 packet = sctp_ootb_pkt_new(asoc, chunk);
4240
4241 if (!packet)
4242 goto nomem_pkt;
4243
4244 if (sctp_test_T_bit(abort))
4245 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
4246
4247 abort->skb->sk = ep->base.sk;
4248
4249 sctp_packet_append_chunk(packet, abort);
4250
4251 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
4252 SCTP_PACKET(packet));
4253
4254 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004255 }
4256
Linus Torvalds1da177e2005-04-16 15:20:36 -07004257 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09004258
Vlad Yasevich56eb82b2008-10-09 14:33:01 -07004259discard:
4260 sctp_sf_pdiscard(ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004261 return SCTP_DISPOSITION_ABORT;
4262
Vlad Yasevichece25df2007-09-07 16:30:54 -04004263nomem_pkt:
4264 sctp_chunk_free(abort);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004265nomem:
4266 return SCTP_DISPOSITION_NOMEM;
4267}
4268
Wei Yongjunaecedea2007-08-02 16:57:44 +08004269/*
4270 * Handle a protocol violation when the chunk length is invalid.
4271 * "Invalid" length is identified as smaller then the minimal length a
4272 * given chunk can be. For example, a SACK chunk has invalid length
4273 * if it's length is set to be smaller then the size of sctp_sack_chunk_t.
4274 *
4275 * We inform the other end by sending an ABORT with a Protocol Violation
4276 * error code.
4277 *
4278 * Section: Not specified
4279 * Verification Tag: Nothing to do
4280 * Inputs
4281 * (endpoint, asoc, chunk)
4282 *
4283 * Outputs
4284 * (reply_msg, msg_up, counters)
4285 *
4286 * Generate an ABORT chunk and terminate the association.
4287 */
4288static sctp_disposition_t sctp_sf_violation_chunklen(
4289 const struct sctp_endpoint *ep,
4290 const struct sctp_association *asoc,
4291 const sctp_subtype_t type,
4292 void *arg,
4293 sctp_cmd_seq_t *commands)
4294{
Florian Westphal24448442008-03-23 22:46:34 -07004295 static const char err_str[]="The following chunk had invalid length:";
Wei Yongjunaecedea2007-08-02 16:57:44 +08004296
Vlad Yasevichece25df2007-09-07 16:30:54 -04004297 return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
Wei Yongjunaecedea2007-08-02 16:57:44 +08004298 sizeof(err_str));
4299}
4300
Wei Yongjun6f4c6182007-09-19 17:19:52 +08004301/*
4302 * Handle a protocol violation when the parameter length is invalid.
4303 * "Invalid" length is identified as smaller then the minimal length a
4304 * given parameter can be.
4305 */
4306static sctp_disposition_t sctp_sf_violation_paramlen(
4307 const struct sctp_endpoint *ep,
4308 const struct sctp_association *asoc,
4309 const sctp_subtype_t type,
Wei Yongjunba016672008-09-30 05:32:24 -07004310 void *arg, void *ext,
4311 sctp_cmd_seq_t *commands)
4312{
4313 struct sctp_chunk *chunk = arg;
4314 struct sctp_paramhdr *param = ext;
4315 struct sctp_chunk *abort = NULL;
Wei Yongjun6f4c6182007-09-19 17:19:52 +08004316
Wei Yongjunba016672008-09-30 05:32:24 -07004317 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
4318 goto discard;
4319
4320 /* Make the abort chunk. */
4321 abort = sctp_make_violation_paramlen(asoc, chunk, param);
4322 if (!abort)
4323 goto nomem;
4324
4325 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4326 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
4327
4328 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4329 SCTP_ERROR(ECONNABORTED));
4330 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4331 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4332 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
Vlad Yasevich56eb82b2008-10-09 14:33:01 -07004333 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
Wei Yongjunba016672008-09-30 05:32:24 -07004334
4335discard:
4336 sctp_sf_pdiscard(ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
Wei Yongjunba016672008-09-30 05:32:24 -07004337 return SCTP_DISPOSITION_ABORT;
4338nomem:
4339 return SCTP_DISPOSITION_NOMEM;
Wei Yongjun6f4c6182007-09-19 17:19:52 +08004340}
4341
Wei Yongjunaecedea2007-08-02 16:57:44 +08004342/* Handle a protocol violation when the peer trying to advance the
4343 * cumulative tsn ack to a point beyond the max tsn currently sent.
4344 *
4345 * We inform the other end by sending an ABORT with a Protocol Violation
4346 * error code.
4347 */
4348static sctp_disposition_t sctp_sf_violation_ctsn(
4349 const struct sctp_endpoint *ep,
4350 const struct sctp_association *asoc,
4351 const sctp_subtype_t type,
4352 void *arg,
4353 sctp_cmd_seq_t *commands)
4354{
Florian Westphal24448442008-03-23 22:46:34 -07004355 static const char err_str[]="The cumulative tsn ack beyond the max tsn currently sent:";
Wei Yongjunaecedea2007-08-02 16:57:44 +08004356
Vlad Yasevichece25df2007-09-07 16:30:54 -04004357 return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
Wei Yongjunaecedea2007-08-02 16:57:44 +08004358 sizeof(err_str));
4359}
4360
Vlad Yasevichece25df2007-09-07 16:30:54 -04004361/* Handle protocol violation of an invalid chunk bundling. For example,
4362 * when we have an association and we recieve bundled INIT-ACK, or
4363 * SHUDOWN-COMPLETE, our peer is clearly violationg the "MUST NOT bundle"
4364 * statement from the specs. Additinally, there might be an attacker
4365 * on the path and we may not want to continue this communication.
4366 */
4367static sctp_disposition_t sctp_sf_violation_chunk(
4368 const struct sctp_endpoint *ep,
4369 const struct sctp_association *asoc,
4370 const sctp_subtype_t type,
4371 void *arg,
4372 sctp_cmd_seq_t *commands)
4373{
Florian Westphal24448442008-03-23 22:46:34 -07004374 static const char err_str[]="The following chunk violates protocol:";
Vlad Yasevichece25df2007-09-07 16:30:54 -04004375
4376 if (!asoc)
4377 return sctp_sf_violation(ep, asoc, type, arg, commands);
4378
4379 return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
4380 sizeof(err_str));
4381}
Linus Torvalds1da177e2005-04-16 15:20:36 -07004382/***************************************************************************
4383 * These are the state functions for handling primitive (Section 10) events.
4384 ***************************************************************************/
4385/*
4386 * sctp_sf_do_prm_asoc
4387 *
4388 * Section: 10.1 ULP-to-SCTP
4389 * B) Associate
4390 *
4391 * Format: ASSOCIATE(local SCTP instance name, destination transport addr,
4392 * outbound stream count)
4393 * -> association id [,destination transport addr list] [,outbound stream
4394 * count]
4395 *
4396 * This primitive allows the upper layer to initiate an association to a
4397 * specific peer endpoint.
4398 *
4399 * The peer endpoint shall be specified by one of the transport addresses
4400 * which defines the endpoint (see Section 1.4). If the local SCTP
4401 * instance has not been initialized, the ASSOCIATE is considered an
4402 * error.
4403 * [This is not relevant for the kernel implementation since we do all
4404 * initialization at boot time. It we hadn't initialized we wouldn't
4405 * get anywhere near this code.]
4406 *
4407 * An association id, which is a local handle to the SCTP association,
4408 * will be returned on successful establishment of the association. If
4409 * SCTP is not able to open an SCTP association with the peer endpoint,
4410 * an error is returned.
4411 * [In the kernel implementation, the struct sctp_association needs to
4412 * be created BEFORE causing this primitive to run.]
4413 *
4414 * Other association parameters may be returned, including the
4415 * complete destination transport addresses of the peer as well as the
4416 * outbound stream count of the local endpoint. One of the transport
4417 * address from the returned destination addresses will be selected by
4418 * the local endpoint as default primary path for sending SCTP packets
4419 * to this peer. The returned "destination transport addr list" can
4420 * be used by the ULP to change the default primary path or to force
4421 * sending a packet to a specific transport address. [All of this
4422 * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING
4423 * function.]
4424 *
4425 * Mandatory attributes:
4426 *
4427 * o local SCTP instance name - obtained from the INITIALIZE operation.
4428 * [This is the argument asoc.]
4429 * o destination transport addr - specified as one of the transport
4430 * addresses of the peer endpoint with which the association is to be
4431 * established.
4432 * [This is asoc->peer.active_path.]
4433 * o outbound stream count - the number of outbound streams the ULP
4434 * would like to open towards this peer endpoint.
4435 * [BUG: This is not currently implemented.]
4436 * Optional attributes:
4437 *
4438 * None.
4439 *
4440 * The return value is a disposition.
4441 */
4442sctp_disposition_t sctp_sf_do_prm_asoc(const struct sctp_endpoint *ep,
4443 const struct sctp_association *asoc,
4444 const sctp_subtype_t type,
4445 void *arg,
4446 sctp_cmd_seq_t *commands)
4447{
4448 struct sctp_chunk *repl;
Vlad Yasevichab38fb02008-04-12 18:40:06 -07004449 struct sctp_association* my_asoc;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004450
4451 /* The comment below says that we enter COOKIE-WAIT AFTER
4452 * sending the INIT, but that doesn't actually work in our
4453 * implementation...
4454 */
4455 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4456 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
4457
4458 /* RFC 2960 5.1 Normal Establishment of an Association
4459 *
4460 * A) "A" first sends an INIT chunk to "Z". In the INIT, "A"
4461 * must provide its Verification Tag (Tag_A) in the Initiate
4462 * Tag field. Tag_A SHOULD be a random number in the range of
4463 * 1 to 4294967295 (see 5.3.1 for Tag value selection). ...
4464 */
4465
4466 repl = sctp_make_init(asoc, &asoc->base.bind_addr, GFP_ATOMIC, 0);
4467 if (!repl)
4468 goto nomem;
4469
4470 /* Cast away the const modifier, as we want to just
4471 * rerun it through as a sideffect.
4472 */
Vlad Yasevichab38fb02008-04-12 18:40:06 -07004473 my_asoc = (struct sctp_association *)asoc;
4474 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(my_asoc));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004475
Frank Filz3f7a87d2005-06-20 13:14:57 -07004476 /* Choose transport for INIT. */
4477 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
4478 SCTP_CHUNK(repl));
4479
Linus Torvalds1da177e2005-04-16 15:20:36 -07004480 /* After sending the INIT, "A" starts the T1-init timer and
4481 * enters the COOKIE-WAIT state.
4482 */
4483 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4484 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4485 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
4486 return SCTP_DISPOSITION_CONSUME;
4487
4488nomem:
4489 return SCTP_DISPOSITION_NOMEM;
4490}
4491
4492/*
4493 * Process the SEND primitive.
4494 *
4495 * Section: 10.1 ULP-to-SCTP
4496 * E) Send
4497 *
4498 * Format: SEND(association id, buffer address, byte count [,context]
4499 * [,stream id] [,life time] [,destination transport address]
4500 * [,unorder flag] [,no-bundle flag] [,payload protocol-id] )
4501 * -> result
4502 *
4503 * This is the main method to send user data via SCTP.
4504 *
4505 * Mandatory attributes:
4506 *
4507 * o association id - local handle to the SCTP association
4508 *
4509 * o buffer address - the location where the user message to be
4510 * transmitted is stored;
4511 *
4512 * o byte count - The size of the user data in number of bytes;
4513 *
4514 * Optional attributes:
4515 *
4516 * o context - an optional 32 bit integer that will be carried in the
4517 * sending failure notification to the ULP if the transportation of
4518 * this User Message fails.
4519 *
4520 * o stream id - to indicate which stream to send the data on. If not
4521 * specified, stream 0 will be used.
4522 *
4523 * o life time - specifies the life time of the user data. The user data
4524 * will not be sent by SCTP after the life time expires. This
4525 * parameter can be used to avoid efforts to transmit stale
4526 * user messages. SCTP notifies the ULP if the data cannot be
4527 * initiated to transport (i.e. sent to the destination via SCTP's
4528 * send primitive) within the life time variable. However, the
4529 * user data will be transmitted if SCTP has attempted to transmit a
4530 * chunk before the life time expired.
4531 *
4532 * o destination transport address - specified as one of the destination
4533 * transport addresses of the peer endpoint to which this packet
4534 * should be sent. Whenever possible, SCTP should use this destination
4535 * transport address for sending the packets, instead of the current
4536 * primary path.
4537 *
4538 * o unorder flag - this flag, if present, indicates that the user
4539 * would like the data delivered in an unordered fashion to the peer
4540 * (i.e., the U flag is set to 1 on all DATA chunks carrying this
4541 * message).
4542 *
4543 * o no-bundle flag - instructs SCTP not to bundle this user data with
4544 * other outbound DATA chunks. SCTP MAY still bundle even when
4545 * this flag is present, when faced with network congestion.
4546 *
4547 * o payload protocol-id - A 32 bit unsigned integer that is to be
4548 * passed to the peer indicating the type of payload protocol data
4549 * being transmitted. This value is passed as opaque data by SCTP.
4550 *
4551 * The return value is the disposition.
4552 */
4553sctp_disposition_t sctp_sf_do_prm_send(const struct sctp_endpoint *ep,
4554 const struct sctp_association *asoc,
4555 const sctp_subtype_t type,
4556 void *arg,
4557 sctp_cmd_seq_t *commands)
4558{
4559 struct sctp_chunk *chunk = arg;
4560
4561 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
4562 return SCTP_DISPOSITION_CONSUME;
4563}
4564
4565/*
4566 * Process the SHUTDOWN primitive.
4567 *
4568 * Section: 10.1:
4569 * C) Shutdown
4570 *
4571 * Format: SHUTDOWN(association id)
4572 * -> result
4573 *
4574 * Gracefully closes an association. Any locally queued user data
4575 * will be delivered to the peer. The association will be terminated only
4576 * after the peer acknowledges all the SCTP packets sent. A success code
4577 * will be returned on successful termination of the association. If
4578 * attempting to terminate the association results in a failure, an error
4579 * code shall be returned.
4580 *
4581 * Mandatory attributes:
4582 *
4583 * o association id - local handle to the SCTP association
4584 *
4585 * Optional attributes:
4586 *
4587 * None.
4588 *
4589 * The return value is the disposition.
4590 */
4591sctp_disposition_t sctp_sf_do_9_2_prm_shutdown(
4592 const struct sctp_endpoint *ep,
4593 const struct sctp_association *asoc,
4594 const sctp_subtype_t type,
4595 void *arg,
4596 sctp_cmd_seq_t *commands)
4597{
4598 int disposition;
4599
4600 /* From 9.2 Shutdown of an Association
4601 * Upon receipt of the SHUTDOWN primitive from its upper
4602 * layer, the endpoint enters SHUTDOWN-PENDING state and
4603 * remains there until all outstanding data has been
4604 * acknowledged by its peer. The endpoint accepts no new data
4605 * from its upper layer, but retransmits data to the far end
4606 * if necessary to fill gaps.
4607 */
4608 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4609 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
4610
Linus Torvalds1da177e2005-04-16 15:20:36 -07004611 disposition = SCTP_DISPOSITION_CONSUME;
4612 if (sctp_outq_is_empty(&asoc->outqueue)) {
4613 disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type,
4614 arg, commands);
4615 }
4616 return disposition;
4617}
4618
4619/*
4620 * Process the ABORT primitive.
4621 *
4622 * Section: 10.1:
4623 * C) Abort
4624 *
4625 * Format: Abort(association id [, cause code])
4626 * -> result
4627 *
4628 * Ungracefully closes an association. Any locally queued user data
4629 * will be discarded and an ABORT chunk is sent to the peer. A success code
4630 * will be returned on successful abortion of the association. If
4631 * attempting to abort the association results in a failure, an error
4632 * code shall be returned.
4633 *
4634 * Mandatory attributes:
4635 *
4636 * o association id - local handle to the SCTP association
4637 *
4638 * Optional attributes:
4639 *
4640 * o cause code - reason of the abort to be passed to the peer
4641 *
4642 * None.
4643 *
4644 * The return value is the disposition.
4645 */
4646sctp_disposition_t sctp_sf_do_9_1_prm_abort(
4647 const struct sctp_endpoint *ep,
4648 const struct sctp_association *asoc,
4649 const sctp_subtype_t type,
4650 void *arg,
4651 sctp_cmd_seq_t *commands)
4652{
4653 /* From 9.1 Abort of an Association
4654 * Upon receipt of the ABORT primitive from its upper
4655 * layer, the endpoint enters CLOSED state and
4656 * discard all outstanding data has been
4657 * acknowledged by its peer. The endpoint accepts no new data
4658 * from its upper layer, but retransmits data to the far end
4659 * if necessary to fill gaps.
4660 */
Sridhar Samudralac164a9b2006-08-22 11:50:39 -07004661 struct sctp_chunk *abort = arg;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004662 sctp_disposition_t retval;
4663
4664 retval = SCTP_DISPOSITION_CONSUME;
4665
Sridhar Samudralac164a9b2006-08-22 11:50:39 -07004666 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004667
4668 /* Even if we can't send the ABORT due to low memory delete the
4669 * TCB. This is a departure from our typical NOMEM handling.
4670 */
4671
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004672 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4673 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004674 /* Delete the established association. */
4675 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08004676 SCTP_PERR(SCTP_ERROR_USER_ABORT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004677
4678 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4679 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
4680
4681 return retval;
4682}
4683
4684/* We tried an illegal operation on an association which is closed. */
4685sctp_disposition_t sctp_sf_error_closed(const struct sctp_endpoint *ep,
4686 const struct sctp_association *asoc,
4687 const sctp_subtype_t type,
4688 void *arg,
4689 sctp_cmd_seq_t *commands)
4690{
4691 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, SCTP_ERROR(-EINVAL));
4692 return SCTP_DISPOSITION_CONSUME;
4693}
4694
4695/* We tried an illegal operation on an association which is shutting
4696 * down.
4697 */
4698sctp_disposition_t sctp_sf_error_shutdown(const struct sctp_endpoint *ep,
4699 const struct sctp_association *asoc,
4700 const sctp_subtype_t type,
4701 void *arg,
4702 sctp_cmd_seq_t *commands)
4703{
4704 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR,
4705 SCTP_ERROR(-ESHUTDOWN));
4706 return SCTP_DISPOSITION_CONSUME;
4707}
4708
4709/*
4710 * sctp_cookie_wait_prm_shutdown
4711 *
4712 * Section: 4 Note: 2
4713 * Verification Tag:
4714 * Inputs
4715 * (endpoint, asoc)
4716 *
4717 * The RFC does not explicitly address this issue, but is the route through the
4718 * state table when someone issues a shutdown while in COOKIE_WAIT state.
4719 *
4720 * Outputs
4721 * (timers)
4722 */
4723sctp_disposition_t sctp_sf_cookie_wait_prm_shutdown(
4724 const struct sctp_endpoint *ep,
4725 const struct sctp_association *asoc,
4726 const sctp_subtype_t type,
4727 void *arg,
4728 sctp_cmd_seq_t *commands)
4729{
4730 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4731 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4732
4733 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4734 SCTP_STATE(SCTP_STATE_CLOSED));
4735
4736 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
4737
4738 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
4739
4740 return SCTP_DISPOSITION_DELETE_TCB;
4741}
4742
4743/*
4744 * sctp_cookie_echoed_prm_shutdown
4745 *
4746 * Section: 4 Note: 2
4747 * Verification Tag:
4748 * Inputs
4749 * (endpoint, asoc)
4750 *
4751 * The RFC does not explcitly address this issue, but is the route through the
4752 * state table when someone issues a shutdown while in COOKIE_ECHOED state.
4753 *
4754 * Outputs
4755 * (timers)
4756 */
4757sctp_disposition_t sctp_sf_cookie_echoed_prm_shutdown(
4758 const struct sctp_endpoint *ep,
4759 const struct sctp_association *asoc,
4760 const sctp_subtype_t type,
4761 void *arg, sctp_cmd_seq_t *commands)
4762{
4763 /* There is a single T1 timer, so we should be able to use
4764 * common function with the COOKIE-WAIT state.
4765 */
4766 return sctp_sf_cookie_wait_prm_shutdown(ep, asoc, type, arg, commands);
4767}
4768
4769/*
4770 * sctp_sf_cookie_wait_prm_abort
4771 *
4772 * Section: 4 Note: 2
4773 * Verification Tag:
4774 * Inputs
4775 * (endpoint, asoc)
4776 *
4777 * The RFC does not explicitly address this issue, but is the route through the
4778 * state table when someone issues an abort while in COOKIE_WAIT state.
4779 *
4780 * Outputs
4781 * (timers)
4782 */
4783sctp_disposition_t sctp_sf_cookie_wait_prm_abort(
4784 const struct sctp_endpoint *ep,
4785 const struct sctp_association *asoc,
4786 const sctp_subtype_t type,
4787 void *arg,
4788 sctp_cmd_seq_t *commands)
4789{
Sridhar Samudralac164a9b2006-08-22 11:50:39 -07004790 struct sctp_chunk *abort = arg;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004791 sctp_disposition_t retval;
4792
4793 /* Stop T1-init timer */
4794 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4795 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4796 retval = SCTP_DISPOSITION_CONSUME;
4797
Sridhar Samudralac164a9b2006-08-22 11:50:39 -07004798 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004799
4800 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4801 SCTP_STATE(SCTP_STATE_CLOSED));
4802
4803 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4804
4805 /* Even if we can't send the ABORT due to low memory delete the
4806 * TCB. This is a departure from our typical NOMEM handling.
4807 */
4808
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004809 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4810 SCTP_ERROR(ECONNREFUSED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004811 /* Delete the established association. */
4812 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08004813 SCTP_PERR(SCTP_ERROR_USER_ABORT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004814
4815 return retval;
4816}
4817
4818/*
4819 * sctp_sf_cookie_echoed_prm_abort
4820 *
4821 * Section: 4 Note: 3
4822 * Verification Tag:
4823 * Inputs
4824 * (endpoint, asoc)
4825 *
4826 * The RFC does not explcitly address this issue, but is the route through the
4827 * state table when someone issues an abort while in COOKIE_ECHOED state.
4828 *
4829 * Outputs
4830 * (timers)
4831 */
4832sctp_disposition_t sctp_sf_cookie_echoed_prm_abort(
4833 const struct sctp_endpoint *ep,
4834 const struct sctp_association *asoc,
4835 const sctp_subtype_t type,
4836 void *arg,
4837 sctp_cmd_seq_t *commands)
4838{
4839 /* There is a single T1 timer, so we should be able to use
4840 * common function with the COOKIE-WAIT state.
4841 */
4842 return sctp_sf_cookie_wait_prm_abort(ep, asoc, type, arg, commands);
4843}
4844
4845/*
4846 * sctp_sf_shutdown_pending_prm_abort
4847 *
4848 * Inputs
4849 * (endpoint, asoc)
4850 *
4851 * The RFC does not explicitly address this issue, but is the route through the
4852 * state table when someone issues an abort while in SHUTDOWN-PENDING state.
4853 *
4854 * Outputs
4855 * (timers)
4856 */
4857sctp_disposition_t sctp_sf_shutdown_pending_prm_abort(
4858 const struct sctp_endpoint *ep,
4859 const struct sctp_association *asoc,
4860 const sctp_subtype_t type,
4861 void *arg,
4862 sctp_cmd_seq_t *commands)
4863{
4864 /* Stop the T5-shutdown guard timer. */
4865 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4866 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4867
4868 return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands);
4869}
4870
4871/*
4872 * sctp_sf_shutdown_sent_prm_abort
4873 *
4874 * Inputs
4875 * (endpoint, asoc)
4876 *
4877 * The RFC does not explicitly address this issue, but is the route through the
4878 * state table when someone issues an abort while in SHUTDOWN-SENT state.
4879 *
4880 * Outputs
4881 * (timers)
4882 */
4883sctp_disposition_t sctp_sf_shutdown_sent_prm_abort(
4884 const struct sctp_endpoint *ep,
4885 const struct sctp_association *asoc,
4886 const sctp_subtype_t type,
4887 void *arg,
4888 sctp_cmd_seq_t *commands)
4889{
4890 /* Stop the T2-shutdown timer. */
4891 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4892 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4893
4894 /* Stop the T5-shutdown guard timer. */
4895 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4896 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4897
4898 return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands);
4899}
4900
4901/*
4902 * sctp_sf_cookie_echoed_prm_abort
4903 *
4904 * Inputs
4905 * (endpoint, asoc)
4906 *
4907 * The RFC does not explcitly address this issue, but is the route through the
4908 * state table when someone issues an abort while in COOKIE_ECHOED state.
4909 *
4910 * Outputs
4911 * (timers)
4912 */
4913sctp_disposition_t sctp_sf_shutdown_ack_sent_prm_abort(
4914 const struct sctp_endpoint *ep,
4915 const struct sctp_association *asoc,
4916 const sctp_subtype_t type,
4917 void *arg,
4918 sctp_cmd_seq_t *commands)
4919{
4920 /* The same T2 timer, so we should be able to use
4921 * common function with the SHUTDOWN-SENT state.
4922 */
4923 return sctp_sf_shutdown_sent_prm_abort(ep, asoc, type, arg, commands);
4924}
4925
4926/*
4927 * Process the REQUESTHEARTBEAT primitive
4928 *
4929 * 10.1 ULP-to-SCTP
4930 * J) Request Heartbeat
4931 *
4932 * Format: REQUESTHEARTBEAT(association id, destination transport address)
4933 *
4934 * -> result
4935 *
4936 * Instructs the local endpoint to perform a HeartBeat on the specified
4937 * destination transport address of the given association. The returned
4938 * result should indicate whether the transmission of the HEARTBEAT
4939 * chunk to the destination address is successful.
4940 *
4941 * Mandatory attributes:
4942 *
4943 * o association id - local handle to the SCTP association
4944 *
4945 * o destination transport address - the transport address of the
4946 * association on which a heartbeat should be issued.
4947 */
4948sctp_disposition_t sctp_sf_do_prm_requestheartbeat(
4949 const struct sctp_endpoint *ep,
4950 const struct sctp_association *asoc,
4951 const sctp_subtype_t type,
4952 void *arg,
4953 sctp_cmd_seq_t *commands)
4954{
Vlad Yasevichfb785252007-03-19 17:02:03 -07004955 if (SCTP_DISPOSITION_NOMEM == sctp_sf_heartbeat(ep, asoc, type,
4956 (struct sctp_transport *)arg, commands))
4957 return SCTP_DISPOSITION_NOMEM;
4958
4959 /*
4960 * RFC 2960 (bis), section 8.3
4961 *
4962 * D) Request an on-demand HEARTBEAT on a specific destination
4963 * transport address of a given association.
4964 *
4965 * The endpoint should increment the respective error counter of
4966 * the destination transport address each time a HEARTBEAT is sent
4967 * to that address and not acknowledged within one RTO.
4968 *
4969 */
4970 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_RESET,
4971 SCTP_TRANSPORT(arg));
4972 return SCTP_DISPOSITION_CONSUME;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004973}
4974
4975/*
4976 * ADDIP Section 4.1 ASCONF Chunk Procedures
4977 * When an endpoint has an ASCONF signaled change to be sent to the
4978 * remote endpoint it should do A1 to A9
4979 */
4980sctp_disposition_t sctp_sf_do_prm_asconf(const struct sctp_endpoint *ep,
4981 const struct sctp_association *asoc,
4982 const sctp_subtype_t type,
4983 void *arg,
4984 sctp_cmd_seq_t *commands)
4985{
4986 struct sctp_chunk *chunk = arg;
4987
4988 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
4989 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4990 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
4991 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
4992 return SCTP_DISPOSITION_CONSUME;
4993}
4994
4995/*
4996 * Ignore the primitive event
4997 *
4998 * The return value is the disposition of the primitive.
4999 */
5000sctp_disposition_t sctp_sf_ignore_primitive(
5001 const struct sctp_endpoint *ep,
5002 const struct sctp_association *asoc,
5003 const sctp_subtype_t type,
5004 void *arg,
5005 sctp_cmd_seq_t *commands)
5006{
5007 SCTP_DEBUG_PRINTK("Primitive type %d is ignored.\n", type.primitive);
5008 return SCTP_DISPOSITION_DISCARD;
5009}
5010
5011/***************************************************************************
5012 * These are the state functions for the OTHER events.
5013 ***************************************************************************/
5014
5015/*
5016 * Start the shutdown negotiation.
5017 *
5018 * From Section 9.2:
5019 * Once all its outstanding data has been acknowledged, the endpoint
5020 * shall send a SHUTDOWN chunk to its peer including in the Cumulative
5021 * TSN Ack field the last sequential TSN it has received from the peer.
5022 * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT
5023 * state. If the timer expires, the endpoint must re-send the SHUTDOWN
5024 * with the updated last sequential TSN received from its peer.
5025 *
5026 * The return value is the disposition.
5027 */
5028sctp_disposition_t sctp_sf_do_9_2_start_shutdown(
5029 const struct sctp_endpoint *ep,
5030 const struct sctp_association *asoc,
5031 const sctp_subtype_t type,
5032 void *arg,
5033 sctp_cmd_seq_t *commands)
5034{
5035 struct sctp_chunk *reply;
5036
5037 /* Once all its outstanding data has been acknowledged, the
5038 * endpoint shall send a SHUTDOWN chunk to its peer including
5039 * in the Cumulative TSN Ack field the last sequential TSN it
5040 * has received from the peer.
5041 */
5042 reply = sctp_make_shutdown(asoc, NULL);
5043 if (!reply)
5044 goto nomem;
5045
5046 /* Set the transport for the SHUTDOWN chunk and the timeout for the
5047 * T2-shutdown timer.
5048 */
5049 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5050
5051 /* It shall then start the T2-shutdown timer */
5052 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
5053 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5054
Wei Yongjun536428a2008-09-05 08:55:26 +08005055 /* RFC 4960 Section 9.2
5056 * The sender of the SHUTDOWN MAY also start an overall guard timer
5057 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5058 */
5059 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
5060 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5061
Linus Torvalds1da177e2005-04-16 15:20:36 -07005062 if (asoc->autoclose)
5063 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5064 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
5065
5066 /* and enter the SHUTDOWN-SENT state. */
5067 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5068 SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT));
5069
5070 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5071 *
5072 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09005073 * or SHUTDOWN-ACK.
Linus Torvalds1da177e2005-04-16 15:20:36 -07005074 */
5075 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
5076
5077 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5078
5079 return SCTP_DISPOSITION_CONSUME;
5080
5081nomem:
5082 return SCTP_DISPOSITION_NOMEM;
5083}
5084
5085/*
5086 * Generate a SHUTDOWN ACK now that everything is SACK'd.
5087 *
5088 * From Section 9.2:
5089 *
5090 * If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5091 * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own,
5092 * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the
5093 * endpoint must re-send the SHUTDOWN ACK.
5094 *
5095 * The return value is the disposition.
5096 */
5097sctp_disposition_t sctp_sf_do_9_2_shutdown_ack(
5098 const struct sctp_endpoint *ep,
5099 const struct sctp_association *asoc,
5100 const sctp_subtype_t type,
5101 void *arg,
5102 sctp_cmd_seq_t *commands)
5103{
5104 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
5105 struct sctp_chunk *reply;
5106
5107 /* There are 2 ways of getting here:
5108 * 1) called in response to a SHUTDOWN chunk
5109 * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued.
5110 *
5111 * For the case (2), the arg parameter is set to NULL. We need
5112 * to check that we have a chunk before accessing it's fields.
5113 */
5114 if (chunk) {
5115 if (!sctp_vtag_verify(chunk, asoc))
5116 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
5117
5118 /* Make sure that the SHUTDOWN chunk has a valid length. */
5119 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_shutdown_chunk_t)))
5120 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
5121 commands);
5122 }
5123
5124 /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5125 * shall send a SHUTDOWN ACK ...
5126 */
5127 reply = sctp_make_shutdown_ack(asoc, chunk);
5128 if (!reply)
5129 goto nomem;
5130
5131 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
5132 * the T2-shutdown timer.
5133 */
5134 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5135
5136 /* and start/restart a T2-shutdown timer of its own, */
5137 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5138 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5139
5140 if (asoc->autoclose)
5141 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5142 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
5143
5144 /* Enter the SHUTDOWN-ACK-SENT state. */
5145 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5146 SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT));
5147
5148 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5149 *
5150 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09005151 * or SHUTDOWN-ACK.
Linus Torvalds1da177e2005-04-16 15:20:36 -07005152 */
5153 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
5154
5155 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5156
5157 return SCTP_DISPOSITION_CONSUME;
5158
5159nomem:
5160 return SCTP_DISPOSITION_NOMEM;
5161}
5162
5163/*
5164 * Ignore the event defined as other
5165 *
5166 * The return value is the disposition of the event.
5167 */
5168sctp_disposition_t sctp_sf_ignore_other(const struct sctp_endpoint *ep,
5169 const struct sctp_association *asoc,
5170 const sctp_subtype_t type,
5171 void *arg,
5172 sctp_cmd_seq_t *commands)
5173{
5174 SCTP_DEBUG_PRINTK("The event other type %d is ignored\n", type.other);
5175 return SCTP_DISPOSITION_DISCARD;
5176}
5177
5178/************************************************************
5179 * These are the state functions for handling timeout events.
5180 ************************************************************/
5181
5182/*
5183 * RTX Timeout
5184 *
5185 * Section: 6.3.3 Handle T3-rtx Expiration
5186 *
5187 * Whenever the retransmission timer T3-rtx expires for a destination
5188 * address, do the following:
5189 * [See below]
5190 *
5191 * The return value is the disposition of the chunk.
5192 */
5193sctp_disposition_t sctp_sf_do_6_3_3_rtx(const struct sctp_endpoint *ep,
5194 const struct sctp_association *asoc,
5195 const sctp_subtype_t type,
5196 void *arg,
5197 sctp_cmd_seq_t *commands)
5198{
5199 struct sctp_transport *transport = arg;
5200
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07005201 SCTP_INC_STATS(SCTP_MIB_T3_RTX_EXPIREDS);
5202
Linus Torvalds1da177e2005-04-16 15:20:36 -07005203 if (asoc->overall_error_count >= asoc->max_retrans) {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07005204 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5205 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005206 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5207 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08005208 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005209 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
5210 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
5211 return SCTP_DISPOSITION_DELETE_TCB;
5212 }
5213
5214 /* E1) For the destination address for which the timer
5215 * expires, adjust its ssthresh with rules defined in Section
5216 * 7.2.3 and set the cwnd <- MTU.
5217 */
5218
5219 /* E2) For the destination address for which the timer
5220 * expires, set RTO <- RTO * 2 ("back off the timer"). The
5221 * maximum value discussed in rule C7 above (RTO.max) may be
5222 * used to provide an upper bound to this doubling operation.
5223 */
5224
5225 /* E3) Determine how many of the earliest (i.e., lowest TSN)
5226 * outstanding DATA chunks for the address for which the
5227 * T3-rtx has expired will fit into a single packet, subject
5228 * to the MTU constraint for the path corresponding to the
5229 * destination transport address to which the retransmission
5230 * is being sent (this may be different from the address for
5231 * which the timer expires [see Section 6.4]). Call this
5232 * value K. Bundle and retransmit those K DATA chunks in a
5233 * single packet to the destination endpoint.
5234 *
5235 * Note: Any DATA chunks that were sent to the address for
5236 * which the T3-rtx timer expired but did not fit in one MTU
5237 * (rule E3 above), should be marked for retransmission and
5238 * sent as soon as cwnd allows (normally when a SACK arrives).
5239 */
5240
Linus Torvalds1da177e2005-04-16 15:20:36 -07005241 /* Do some failure management (Section 8.2). */
5242 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
5243
Vlad Yasevich1845a572007-02-21 02:06:19 -08005244 /* NB: Rules E4 and F1 are implicit in R1. */
5245 sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN, SCTP_TRANSPORT(transport));
5246
Linus Torvalds1da177e2005-04-16 15:20:36 -07005247 return SCTP_DISPOSITION_CONSUME;
5248}
5249
5250/*
5251 * Generate delayed SACK on timeout
5252 *
5253 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
5254 *
5255 * The guidelines on delayed acknowledgement algorithm specified in
5256 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
5257 * acknowledgement SHOULD be generated for at least every second packet
5258 * (not every second DATA chunk) received, and SHOULD be generated
5259 * within 200 ms of the arrival of any unacknowledged DATA chunk. In
5260 * some situations it may be beneficial for an SCTP transmitter to be
5261 * more conservative than the algorithms detailed in this document
5262 * allow. However, an SCTP transmitter MUST NOT be more aggressive than
5263 * the following algorithms allow.
5264 */
5265sctp_disposition_t sctp_sf_do_6_2_sack(const struct sctp_endpoint *ep,
5266 const struct sctp_association *asoc,
5267 const sctp_subtype_t type,
5268 void *arg,
5269 sctp_cmd_seq_t *commands)
5270{
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07005271 SCTP_INC_STATS(SCTP_MIB_DELAY_SACK_EXPIREDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005272 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
5273 return SCTP_DISPOSITION_CONSUME;
5274}
5275
5276/*
Frank Filz3f7a87d2005-06-20 13:14:57 -07005277 * sctp_sf_t1_init_timer_expire
Linus Torvalds1da177e2005-04-16 15:20:36 -07005278 *
5279 * Section: 4 Note: 2
5280 * Verification Tag:
5281 * Inputs
5282 * (endpoint, asoc)
5283 *
5284 * RFC 2960 Section 4 Notes
5285 * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT
5286 * and re-start the T1-init timer without changing state. This MUST
5287 * be repeated up to 'Max.Init.Retransmits' times. After that, the
5288 * endpoint MUST abort the initialization process and report the
5289 * error to SCTP user.
5290 *
Frank Filz3f7a87d2005-06-20 13:14:57 -07005291 * Outputs
5292 * (timers, events)
5293 *
5294 */
5295sctp_disposition_t sctp_sf_t1_init_timer_expire(const struct sctp_endpoint *ep,
5296 const struct sctp_association *asoc,
5297 const sctp_subtype_t type,
5298 void *arg,
5299 sctp_cmd_seq_t *commands)
5300{
5301 struct sctp_chunk *repl = NULL;
5302 struct sctp_bind_addr *bp;
5303 int attempts = asoc->init_err_counter + 1;
5304
5305 SCTP_DEBUG_PRINTK("Timer T1 expired (INIT).\n");
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07005306 SCTP_INC_STATS(SCTP_MIB_T1_INIT_EXPIREDS);
Frank Filz3f7a87d2005-06-20 13:14:57 -07005307
Vlad Yasevich81845c22006-01-30 15:59:54 -08005308 if (attempts <= asoc->max_init_attempts) {
Frank Filz3f7a87d2005-06-20 13:14:57 -07005309 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
5310 repl = sctp_make_init(asoc, bp, GFP_ATOMIC, 0);
5311 if (!repl)
5312 return SCTP_DISPOSITION_NOMEM;
5313
5314 /* Choose transport for INIT. */
5315 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
5316 SCTP_CHUNK(repl));
5317
5318 /* Issue a sideeffect to do the needed accounting. */
5319 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_RESTART,
5320 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
5321
5322 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
5323 } else {
5324 SCTP_DEBUG_PRINTK("Giving up on INIT, attempts: %d"
5325 " max_init_attempts: %d\n",
5326 attempts, asoc->max_init_attempts);
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07005327 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5328 SCTP_ERROR(ETIMEDOUT));
Frank Filz3f7a87d2005-06-20 13:14:57 -07005329 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08005330 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Frank Filz3f7a87d2005-06-20 13:14:57 -07005331 return SCTP_DISPOSITION_DELETE_TCB;
5332 }
5333
5334 return SCTP_DISPOSITION_CONSUME;
5335}
5336
5337/*
5338 * sctp_sf_t1_cookie_timer_expire
5339 *
5340 * Section: 4 Note: 2
5341 * Verification Tag:
5342 * Inputs
5343 * (endpoint, asoc)
5344 *
5345 * RFC 2960 Section 4 Notes
5346 * 3) If the T1-cookie timer expires, the endpoint MUST retransmit
Linus Torvalds1da177e2005-04-16 15:20:36 -07005347 * COOKIE ECHO and re-start the T1-cookie timer without changing
5348 * state. This MUST be repeated up to 'Max.Init.Retransmits' times.
5349 * After that, the endpoint MUST abort the initialization process and
5350 * report the error to SCTP user.
5351 *
5352 * Outputs
5353 * (timers, events)
5354 *
5355 */
Frank Filz3f7a87d2005-06-20 13:14:57 -07005356sctp_disposition_t sctp_sf_t1_cookie_timer_expire(const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005357 const struct sctp_association *asoc,
5358 const sctp_subtype_t type,
5359 void *arg,
5360 sctp_cmd_seq_t *commands)
5361{
Frank Filz3f7a87d2005-06-20 13:14:57 -07005362 struct sctp_chunk *repl = NULL;
5363 int attempts = asoc->init_err_counter + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005364
Frank Filz3f7a87d2005-06-20 13:14:57 -07005365 SCTP_DEBUG_PRINTK("Timer T1 expired (COOKIE-ECHO).\n");
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07005366 SCTP_INC_STATS(SCTP_MIB_T1_COOKIE_EXPIREDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005367
Vlad Yasevich81845c22006-01-30 15:59:54 -08005368 if (attempts <= asoc->max_init_attempts) {
Frank Filz3f7a87d2005-06-20 13:14:57 -07005369 repl = sctp_make_cookie_echo(asoc, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005370 if (!repl)
Frank Filz3f7a87d2005-06-20 13:14:57 -07005371 return SCTP_DISPOSITION_NOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005372
Vlad Yasevich96cd0d32008-09-08 14:00:26 -04005373 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
5374 SCTP_CHUNK(repl));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005375 /* Issue a sideeffect to do the needed accounting. */
Frank Filz3f7a87d2005-06-20 13:14:57 -07005376 sctp_add_cmd_sf(commands, SCTP_CMD_COOKIEECHO_RESTART,
5377 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
5378
Linus Torvalds1da177e2005-04-16 15:20:36 -07005379 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
5380 } else {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07005381 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5382 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005383 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08005384 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005385 return SCTP_DISPOSITION_DELETE_TCB;
5386 }
5387
5388 return SCTP_DISPOSITION_CONSUME;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005389}
5390
5391/* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN
5392 * with the updated last sequential TSN received from its peer.
5393 *
5394 * An endpoint should limit the number of retransmissions of the
5395 * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'.
5396 * If this threshold is exceeded the endpoint should destroy the TCB and
5397 * MUST report the peer endpoint unreachable to the upper layer (and
5398 * thus the association enters the CLOSED state). The reception of any
5399 * packet from its peer (i.e. as the peer sends all of its queued DATA
5400 * chunks) should clear the endpoint's retransmission count and restart
5401 * the T2-Shutdown timer, giving its peer ample opportunity to transmit
5402 * all of its queued DATA chunks that have not yet been sent.
5403 */
5404sctp_disposition_t sctp_sf_t2_timer_expire(const struct sctp_endpoint *ep,
5405 const struct sctp_association *asoc,
5406 const sctp_subtype_t type,
5407 void *arg,
5408 sctp_cmd_seq_t *commands)
5409{
5410 struct sctp_chunk *reply = NULL;
5411
5412 SCTP_DEBUG_PRINTK("Timer T2 expired.\n");
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07005413 SCTP_INC_STATS(SCTP_MIB_T2_SHUTDOWN_EXPIREDS);
5414
Neil Horman58fbbed2008-02-29 11:40:56 -08005415 ((struct sctp_association *)asoc)->shutdown_retries++;
5416
Linus Torvalds1da177e2005-04-16 15:20:36 -07005417 if (asoc->overall_error_count >= asoc->max_retrans) {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07005418 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5419 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005420 /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5421 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08005422 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005423 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
5424 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
5425 return SCTP_DISPOSITION_DELETE_TCB;
5426 }
5427
5428 switch (asoc->state) {
5429 case SCTP_STATE_SHUTDOWN_SENT:
5430 reply = sctp_make_shutdown(asoc, NULL);
5431 break;
5432
5433 case SCTP_STATE_SHUTDOWN_ACK_SENT:
5434 reply = sctp_make_shutdown_ack(asoc, NULL);
5435 break;
5436
5437 default:
5438 BUG();
5439 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07005440 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07005441
5442 if (!reply)
5443 goto nomem;
5444
5445 /* Do some failure management (Section 8.2). */
5446 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
5447 SCTP_TRANSPORT(asoc->shutdown_last_sent_to));
5448
5449 /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for
5450 * the T2-shutdown timer.
5451 */
5452 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5453
5454 /* Restart the T2-shutdown timer. */
5455 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5456 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5457 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5458 return SCTP_DISPOSITION_CONSUME;
5459
5460nomem:
5461 return SCTP_DISPOSITION_NOMEM;
5462}
5463
5464/*
5465 * ADDIP Section 4.1 ASCONF CHunk Procedures
5466 * If the T4 RTO timer expires the endpoint should do B1 to B5
5467 */
5468sctp_disposition_t sctp_sf_t4_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 struct sctp_chunk *chunk = asoc->addip_last_asconf;
5476 struct sctp_transport *transport = chunk->transport;
5477
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07005478 SCTP_INC_STATS(SCTP_MIB_T4_RTO_EXPIREDS);
5479
Linus Torvalds1da177e2005-04-16 15:20:36 -07005480 /* ADDIP 4.1 B1) Increment the error counters and perform path failure
5481 * detection on the appropriate destination address as defined in
5482 * RFC2960 [5] section 8.1 and 8.2.
5483 */
5484 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
5485
5486 /* Reconfig T4 timer and transport. */
5487 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
5488
5489 /* ADDIP 4.1 B2) Increment the association error counters and perform
5490 * endpoint failure detection on the association as defined in
5491 * RFC2960 [5] section 8.1 and 8.2.
5492 * association error counter is incremented in SCTP_CMD_STRIKE.
5493 */
5494 if (asoc->overall_error_count >= asoc->max_retrans) {
5495 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5496 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07005497 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5498 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005499 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08005500 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005501 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
Wei Yongjun3d5a0192008-10-09 14:32:24 -07005502 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005503 return SCTP_DISPOSITION_ABORT;
5504 }
5505
5506 /* ADDIP 4.1 B3) Back-off the destination address RTO value to which
5507 * the ASCONF chunk was sent by doubling the RTO timer value.
5508 * This is done in SCTP_CMD_STRIKE.
5509 */
5510
5511 /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible
5512 * choose an alternate destination address (please refer to RFC2960
5513 * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09005514 * chunk, it MUST be the same (including its serial number) as the last
Linus Torvalds1da177e2005-04-16 15:20:36 -07005515 * ASCONF sent.
5516 */
5517 sctp_chunk_hold(asoc->addip_last_asconf);
5518 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
5519 SCTP_CHUNK(asoc->addip_last_asconf));
5520
5521 /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different
5522 * destination is selected, then the RTO used will be that of the new
5523 * destination address.
5524 */
5525 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5526 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
5527
5528 return SCTP_DISPOSITION_CONSUME;
5529}
5530
5531/* sctpimpguide-05 Section 2.12.2
5532 * The sender of the SHUTDOWN MAY also start an overall guard timer
5533 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5534 * At the expiration of this timer the sender SHOULD abort the association
5535 * by sending an ABORT chunk.
5536 */
5537sctp_disposition_t sctp_sf_t5_timer_expire(const struct sctp_endpoint *ep,
5538 const struct sctp_association *asoc,
5539 const sctp_subtype_t type,
5540 void *arg,
5541 sctp_cmd_seq_t *commands)
5542{
5543 struct sctp_chunk *reply = NULL;
5544
5545 SCTP_DEBUG_PRINTK("Timer T5 expired.\n");
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07005546 SCTP_INC_STATS(SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005547
5548 reply = sctp_make_abort(asoc, NULL, 0);
5549 if (!reply)
5550 goto nomem;
5551
5552 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07005553 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5554 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005555 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08005556 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005557
Vlad Yasevicha1080a82008-10-09 14:33:26 -07005558 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
5559 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
5560
Linus Torvalds1da177e2005-04-16 15:20:36 -07005561 return SCTP_DISPOSITION_DELETE_TCB;
5562nomem:
5563 return SCTP_DISPOSITION_NOMEM;
5564}
5565
5566/* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires,
5567 * the association is automatically closed by starting the shutdown process.
5568 * The work that needs to be done is same as when SHUTDOWN is initiated by
5569 * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown().
5570 */
5571sctp_disposition_t sctp_sf_autoclose_timer_expire(
5572 const struct sctp_endpoint *ep,
5573 const struct sctp_association *asoc,
5574 const sctp_subtype_t type,
5575 void *arg,
5576 sctp_cmd_seq_t *commands)
5577{
5578 int disposition;
5579
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07005580 SCTP_INC_STATS(SCTP_MIB_AUTOCLOSE_EXPIREDS);
5581
Linus Torvalds1da177e2005-04-16 15:20:36 -07005582 /* From 9.2 Shutdown of an Association
5583 * Upon receipt of the SHUTDOWN primitive from its upper
5584 * layer, the endpoint enters SHUTDOWN-PENDING state and
5585 * remains there until all outstanding data has been
5586 * acknowledged by its peer. The endpoint accepts no new data
5587 * from its upper layer, but retransmits data to the far end
5588 * if necessary to fill gaps.
5589 */
5590 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5591 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
5592
Linus Torvalds1da177e2005-04-16 15:20:36 -07005593 disposition = SCTP_DISPOSITION_CONSUME;
5594 if (sctp_outq_is_empty(&asoc->outqueue)) {
5595 disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type,
5596 arg, commands);
5597 }
5598 return disposition;
5599}
5600
5601/*****************************************************************************
5602 * These are sa state functions which could apply to all types of events.
5603 ****************************************************************************/
5604
5605/*
5606 * This table entry is not implemented.
5607 *
5608 * Inputs
5609 * (endpoint, asoc, chunk)
5610 *
5611 * The return value is the disposition of the chunk.
5612 */
5613sctp_disposition_t sctp_sf_not_impl(const struct sctp_endpoint *ep,
5614 const struct sctp_association *asoc,
5615 const sctp_subtype_t type,
5616 void *arg,
5617 sctp_cmd_seq_t *commands)
5618{
5619 return SCTP_DISPOSITION_NOT_IMPL;
5620}
5621
5622/*
5623 * This table entry represents a bug.
5624 *
5625 * Inputs
5626 * (endpoint, asoc, chunk)
5627 *
5628 * The return value is the disposition of the chunk.
5629 */
5630sctp_disposition_t sctp_sf_bug(const struct sctp_endpoint *ep,
5631 const struct sctp_association *asoc,
5632 const sctp_subtype_t type,
5633 void *arg,
5634 sctp_cmd_seq_t *commands)
5635{
5636 return SCTP_DISPOSITION_BUG;
5637}
5638
5639/*
5640 * This table entry represents the firing of a timer in the wrong state.
5641 * Since timer deletion cannot be guaranteed a timer 'may' end up firing
5642 * when the association is in the wrong state. This event should
5643 * be ignored, so as to prevent any rearming of the timer.
5644 *
5645 * Inputs
5646 * (endpoint, asoc, chunk)
5647 *
5648 * The return value is the disposition of the chunk.
5649 */
5650sctp_disposition_t sctp_sf_timer_ignore(const struct sctp_endpoint *ep,
5651 const struct sctp_association *asoc,
5652 const sctp_subtype_t type,
5653 void *arg,
5654 sctp_cmd_seq_t *commands)
5655{
5656 SCTP_DEBUG_PRINTK("Timer %d ignored.\n", type.chunk);
5657 return SCTP_DISPOSITION_CONSUME;
5658}
5659
5660/********************************************************************
5661 * 2nd Level Abstractions
5662 ********************************************************************/
5663
5664/* Pull the SACK chunk based on the SACK header. */
5665static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk)
5666{
5667 struct sctp_sackhdr *sack;
5668 unsigned int len;
5669 __u16 num_blocks;
5670 __u16 num_dup_tsns;
5671
5672 /* Protect ourselves from reading too far into
5673 * the skb from a bogus sender.
5674 */
5675 sack = (struct sctp_sackhdr *) chunk->skb->data;
5676
5677 num_blocks = ntohs(sack->num_gap_ack_blocks);
5678 num_dup_tsns = ntohs(sack->num_dup_tsns);
5679 len = sizeof(struct sctp_sackhdr);
5680 len += (num_blocks + num_dup_tsns) * sizeof(__u32);
5681 if (len > chunk->skb->len)
5682 return NULL;
5683
5684 skb_pull(chunk->skb, len);
5685
5686 return sack;
5687}
5688
5689/* Create an ABORT packet to be sent as a response, with the specified
5690 * error causes.
5691 */
5692static struct sctp_packet *sctp_abort_pkt_new(const struct sctp_endpoint *ep,
5693 const struct sctp_association *asoc,
5694 struct sctp_chunk *chunk,
5695 const void *payload,
5696 size_t paylen)
5697{
5698 struct sctp_packet *packet;
5699 struct sctp_chunk *abort;
5700
5701 packet = sctp_ootb_pkt_new(asoc, chunk);
5702
5703 if (packet) {
5704 /* Make an ABORT.
5705 * The T bit will be set if the asoc is NULL.
5706 */
5707 abort = sctp_make_abort(asoc, chunk, paylen);
5708 if (!abort) {
5709 sctp_ootb_pkt_free(packet);
5710 return NULL;
5711 }
Jerome Forissier047a2422005-04-28 11:58:43 -07005712
5713 /* Reflect vtag if T-Bit is set */
5714 if (sctp_test_T_bit(abort))
5715 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
5716
Linus Torvalds1da177e2005-04-16 15:20:36 -07005717 /* Add specified error causes, i.e., payload, to the
5718 * end of the chunk.
5719 */
5720 sctp_addto_chunk(abort, paylen, payload);
5721
5722 /* Set the skb to the belonging sock for accounting. */
5723 abort->skb->sk = ep->base.sk;
5724
5725 sctp_packet_append_chunk(packet, abort);
5726
5727 }
5728
5729 return packet;
5730}
5731
5732/* Allocate a packet for responding in the OOTB conditions. */
5733static struct sctp_packet *sctp_ootb_pkt_new(const struct sctp_association *asoc,
5734 const struct sctp_chunk *chunk)
5735{
5736 struct sctp_packet *packet;
5737 struct sctp_transport *transport;
5738 __u16 sport;
5739 __u16 dport;
5740 __u32 vtag;
5741
5742 /* Get the source and destination port from the inbound packet. */
5743 sport = ntohs(chunk->sctp_hdr->dest);
5744 dport = ntohs(chunk->sctp_hdr->source);
5745
5746 /* The V-tag is going to be the same as the inbound packet if no
5747 * association exists, otherwise, use the peer's vtag.
5748 */
5749 if (asoc) {
Wei Yongjun02c4e122007-08-31 10:03:58 +08005750 /* Special case the INIT-ACK as there is no peer's vtag
5751 * yet.
5752 */
5753 switch(chunk->chunk_hdr->type) {
5754 case SCTP_CID_INIT_ACK:
5755 {
5756 sctp_initack_chunk_t *initack;
5757
5758 initack = (sctp_initack_chunk_t *)chunk->chunk_hdr;
5759 vtag = ntohl(initack->init_hdr.init_tag);
5760 break;
5761 }
5762 default:
5763 vtag = asoc->peer.i.init_tag;
5764 break;
5765 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07005766 } else {
5767 /* Special case the INIT and stale COOKIE_ECHO as there is no
5768 * vtag yet.
5769 */
5770 switch(chunk->chunk_hdr->type) {
5771 case SCTP_CID_INIT:
5772 {
5773 sctp_init_chunk_t *init;
5774
5775 init = (sctp_init_chunk_t *)chunk->chunk_hdr;
5776 vtag = ntohl(init->init_hdr.init_tag);
5777 break;
5778 }
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09005779 default:
Linus Torvalds1da177e2005-04-16 15:20:36 -07005780 vtag = ntohl(chunk->sctp_hdr->vtag);
5781 break;
5782 }
5783 }
5784
5785 /* Make a transport for the bucket, Eliza... */
Al Viro6a1e5f32006-11-20 17:12:25 -08005786 transport = sctp_transport_new(sctp_source(chunk), GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005787 if (!transport)
5788 goto nomem;
5789
5790 /* Cache a route for the transport with the chunk's destination as
5791 * the source address.
5792 */
Al Viro16b0a032006-11-20 17:13:38 -08005793 sctp_transport_route(transport, (union sctp_addr *)&chunk->dest,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005794 sctp_sk(sctp_get_ctl_sock()));
5795
5796 packet = sctp_packet_init(&transport->packet, transport, sport, dport);
5797 packet = sctp_packet_config(packet, vtag, 0);
5798
5799 return packet;
5800
5801nomem:
5802 return NULL;
5803}
5804
5805/* Free the packet allocated earlier for responding in the OOTB condition. */
5806void sctp_ootb_pkt_free(struct sctp_packet *packet)
5807{
5808 sctp_transport_free(packet->transport);
5809}
5810
5811/* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */
5812static void sctp_send_stale_cookie_err(const struct sctp_endpoint *ep,
5813 const struct sctp_association *asoc,
5814 const struct sctp_chunk *chunk,
5815 sctp_cmd_seq_t *commands,
5816 struct sctp_chunk *err_chunk)
5817{
5818 struct sctp_packet *packet;
5819
5820 if (err_chunk) {
5821 packet = sctp_ootb_pkt_new(asoc, chunk);
5822 if (packet) {
5823 struct sctp_signed_cookie *cookie;
5824
5825 /* Override the OOTB vtag from the cookie. */
5826 cookie = chunk->subh.cookie_hdr;
5827 packet->vtag = cookie->c.peer_vtag;
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09005828
Linus Torvalds1da177e2005-04-16 15:20:36 -07005829 /* Set the skb to the belonging sock for accounting. */
5830 err_chunk->skb->sk = ep->base.sk;
5831 sctp_packet_append_chunk(packet, err_chunk);
5832 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
5833 SCTP_PACKET(packet));
5834 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
5835 } else
5836 sctp_chunk_free (err_chunk);
5837 }
5838}
5839
5840
5841/* Process a data chunk */
5842static int sctp_eat_data(const struct sctp_association *asoc,
5843 struct sctp_chunk *chunk,
5844 sctp_cmd_seq_t *commands)
5845{
5846 sctp_datahdr_t *data_hdr;
5847 struct sctp_chunk *err;
5848 size_t datalen;
5849 sctp_verb_t deliver;
5850 int tmp;
5851 __u32 tsn;
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005852 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
Neil Horman049b3ff2005-11-11 16:08:24 -08005853 struct sock *sk = asoc->base.sk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005854
5855 data_hdr = chunk->subh.data_hdr = (sctp_datahdr_t *)chunk->skb->data;
5856 skb_pull(chunk->skb, sizeof(sctp_datahdr_t));
5857
5858 tsn = ntohl(data_hdr->tsn);
5859 SCTP_DEBUG_PRINTK("eat_data: TSN 0x%x.\n", tsn);
5860
5861 /* ASSERT: Now skb->data is really the user data. */
5862
Linus Torvalds1da177e2005-04-16 15:20:36 -07005863 /* Process ECN based congestion.
5864 *
5865 * Since the chunk structure is reused for all chunks within
5866 * a packet, we use ecn_ce_done to track if we've already
5867 * done CE processing for this packet.
5868 *
5869 * We need to do ECN processing even if we plan to discard the
5870 * chunk later.
5871 */
5872
5873 if (!chunk->ecn_ce_done) {
5874 struct sctp_af *af;
5875 chunk->ecn_ce_done = 1;
5876
5877 af = sctp_get_af_specific(
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07005878 ipver2af(ip_hdr(chunk->skb)->version));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005879
5880 if (af && af->is_ce(chunk->skb) && asoc->peer.ecn_capable) {
5881 /* Do real work as sideffect. */
5882 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_CE,
5883 SCTP_U32(tsn));
5884 }
5885 }
5886
5887 tmp = sctp_tsnmap_check(&asoc->peer.tsn_map, tsn);
5888 if (tmp < 0) {
5889 /* The TSN is too high--silently discard the chunk and
5890 * count on it getting retransmitted later.
5891 */
5892 return SCTP_IERROR_HIGH_TSN;
5893 } else if (tmp > 0) {
5894 /* This is a duplicate. Record it. */
5895 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_DUP, SCTP_U32(tsn));
5896 return SCTP_IERROR_DUP_TSN;
5897 }
5898
5899 /* This is a new TSN. */
5900
5901 /* Discard if there is no room in the receive window.
5902 * Actually, allow a little bit of overflow (up to a MTU).
5903 */
5904 datalen = ntohs(chunk->chunk_hdr->length);
5905 datalen -= sizeof(sctp_data_chunk_t);
5906
5907 deliver = SCTP_CMD_CHUNK_ULP;
5908
5909 /* Think about partial delivery. */
5910 if ((datalen >= asoc->rwnd) && (!asoc->ulpq.pd_mode)) {
5911
5912 /* Even if we don't accept this chunk there is
5913 * memory pressure.
5914 */
5915 sctp_add_cmd_sf(commands, SCTP_CMD_PART_DELIVER, SCTP_NULL());
5916 }
5917
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09005918 /* Spill over rwnd a little bit. Note: While allowed, this spill over
Linus Torvalds1da177e2005-04-16 15:20:36 -07005919 * seems a bit troublesome in that frag_point varies based on
5920 * PMTU. In cases, such as loopback, this might be a rather
5921 * large spill over.
5922 */
Neil Horman4d93df02007-08-15 16:07:44 -07005923 if ((!chunk->data_accepted) && (!asoc->rwnd || asoc->rwnd_over ||
5924 (datalen > asoc->rwnd + asoc->frag_point))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07005925
5926 /* If this is the next TSN, consider reneging to make
5927 * room. Note: Playing nice with a confused sender. A
5928 * malicious sender can still eat up all our buffer
5929 * space and in the future we may want to detect and
5930 * do more drastic reneging.
5931 */
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005932 if (sctp_tsnmap_has_gap(map) &&
5933 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07005934 SCTP_DEBUG_PRINTK("Reneging for tsn:%u\n", tsn);
5935 deliver = SCTP_CMD_RENEGE;
5936 } else {
5937 SCTP_DEBUG_PRINTK("Discard tsn: %u len: %Zd, "
5938 "rwnd: %d\n", tsn, datalen,
5939 asoc->rwnd);
5940 return SCTP_IERROR_IGNORE_TSN;
5941 }
5942 }
5943
5944 /*
Neil Horman4d93df02007-08-15 16:07:44 -07005945 * Also try to renege to limit our memory usage in the event that
5946 * we are under memory pressure
Hideo Aoki3ab224b2007-12-31 00:11:19 -08005947 * If we can't renege, don't worry about it, the sk_rmem_schedule
Neil Horman4d93df02007-08-15 16:07:44 -07005948 * in sctp_ulpevent_make_rcvmsg will drop the frame if we grow our
5949 * memory usage too much
5950 */
5951 if (*sk->sk_prot_creator->memory_pressure) {
5952 if (sctp_tsnmap_has_gap(map) &&
5953 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
5954 SCTP_DEBUG_PRINTK("Under Pressure! Reneging for tsn:%u\n", tsn);
5955 deliver = SCTP_CMD_RENEGE;
5956 }
5957 }
5958
5959 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -07005960 * Section 3.3.10.9 No User Data (9)
5961 *
5962 * Cause of error
5963 * ---------------
5964 * No User Data: This error cause is returned to the originator of a
5965 * DATA chunk if a received DATA chunk has no user data.
5966 */
5967 if (unlikely(0 == datalen)) {
5968 err = sctp_make_abort_no_data(asoc, chunk, tsn);
5969 if (err) {
5970 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
5971 SCTP_CHUNK(err));
5972 }
5973 /* We are going to ABORT, so we might as well stop
5974 * processing the rest of the chunks in the packet.
5975 */
5976 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07005977 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5978 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005979 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08005980 SCTP_PERR(SCTP_ERROR_NO_DATA));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005981 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
5982 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
5983 return SCTP_IERROR_NO_DATA;
5984 }
5985
Sridhar Samudrala9faa7302006-07-21 14:49:07 -07005986 chunk->data_accepted = 1;
5987
Linus Torvalds1da177e2005-04-16 15:20:36 -07005988 /* Note: Some chunks may get overcounted (if we drop) or overcounted
5989 * if we renege and the chunk arrives again.
5990 */
5991 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
5992 SCTP_INC_STATS(SCTP_MIB_INUNORDERCHUNKS);
5993 else
5994 SCTP_INC_STATS(SCTP_MIB_INORDERCHUNKS);
5995
5996 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
5997 *
5998 * If an endpoint receive a DATA chunk with an invalid stream
5999 * identifier, it shall acknowledge the reception of the DATA chunk
6000 * following the normal procedure, immediately send an ERROR chunk
6001 * with cause set to "Invalid Stream Identifier" (See Section 3.3.10)
6002 * and discard the DATA chunk.
6003 */
6004 if (ntohs(data_hdr->stream) >= asoc->c.sinit_max_instreams) {
Vlad Yasevich3888e9e2008-07-08 02:28:39 -07006005 /* Mark tsn as received even though we drop it */
6006 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_TSN, SCTP_U32(tsn));
6007
Linus Torvalds1da177e2005-04-16 15:20:36 -07006008 err = sctp_make_op_error(asoc, chunk, SCTP_ERROR_INV_STRM,
6009 &data_hdr->stream,
6010 sizeof(data_hdr->stream));
6011 if (err)
6012 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
6013 SCTP_CHUNK(err));
6014 return SCTP_IERROR_BAD_STREAM;
6015 }
6016
6017 /* Send the data up to the user. Note: Schedule the
6018 * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK
6019 * chunk needs the updated rwnd.
6020 */
6021 sctp_add_cmd_sf(commands, deliver, SCTP_CHUNK(chunk));
6022
6023 return SCTP_IERROR_NO_ERROR;
6024}