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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* SCTP kernel reference Implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999-2000 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 * Copyright (c) 2001-2002 Intel Corp.
6 * Copyright (c) 2002 Nokia Corp.
7 *
8 * This file is part of the SCTP kernel reference Implementation
9 *
10 * This is part of the SCTP Linux Kernel Reference Implementation.
11 *
12 * These are the state functions for the state machine.
13 *
14 * The SCTP reference implementation is free software;
15 * you can redistribute it and/or modify it under the terms of
16 * the GNU General Public License as published by
17 * the Free Software Foundation; either version 2, or (at your option)
18 * any later version.
19 *
20 * The SCTP reference implementation is distributed in the hope that it
21 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
22 * ************************
23 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
24 * See the GNU General Public License for more details.
25 *
26 * You should have received a copy of the GNU General Public License
27 * along with GNU CC; see the file COPYING. If not, write to
28 * the Free Software Foundation, 59 Temple Place - Suite 330,
29 * Boston, MA 02111-1307, USA.
30 *
31 * Please send any bug reports or fixes you make to the
32 * email address(es):
33 * lksctp developers <lksctp-developers@lists.sourceforge.net>
34 *
35 * Or submit a bug report through the following website:
36 * http://www.sf.net/projects/lksctp
37 *
38 * Written or modified by:
39 * La Monte H.P. Yarroll <piggy@acm.org>
40 * Karl Knutson <karl@athena.chicago.il.us>
41 * Mathew Kotowsky <kotowsky@sctp.org>
42 * Sridhar Samudrala <samudrala@us.ibm.com>
43 * Jon Grimm <jgrimm@us.ibm.com>
44 * Hui Huang <hui.huang@nokia.com>
45 * Dajiang Zhang <dajiang.zhang@nokia.com>
46 * Daisy Chang <daisyc@us.ibm.com>
47 * Ardelle Fan <ardelle.fan@intel.com>
48 * Ryan Layer <rmlayer@us.ibm.com>
49 * Kevin Gao <kevin.gao@intel.com>
50 *
51 * Any bugs reported given to us we will try to fix... any fixes shared will
52 * be incorporated into the next SCTP release.
53 */
54
55#include <linux/types.h>
56#include <linux/kernel.h>
57#include <linux/ip.h>
58#include <linux/ipv6.h>
59#include <linux/net.h>
60#include <linux/inet.h>
61#include <net/sock.h>
62#include <net/inet_ecn.h>
63#include <linux/skbuff.h>
64#include <net/sctp/sctp.h>
65#include <net/sctp/sm.h>
66#include <net/sctp/structs.h>
67
68static struct sctp_packet *sctp_abort_pkt_new(const struct sctp_endpoint *ep,
69 const struct sctp_association *asoc,
70 struct sctp_chunk *chunk,
71 const void *payload,
72 size_t paylen);
73static int sctp_eat_data(const struct sctp_association *asoc,
74 struct sctp_chunk *chunk,
75 sctp_cmd_seq_t *commands);
76static struct sctp_packet *sctp_ootb_pkt_new(const struct sctp_association *asoc,
77 const struct sctp_chunk *chunk);
78static void sctp_send_stale_cookie_err(const struct sctp_endpoint *ep,
79 const struct sctp_association *asoc,
80 const struct sctp_chunk *chunk,
81 sctp_cmd_seq_t *commands,
82 struct sctp_chunk *err_chunk);
83static sctp_disposition_t sctp_sf_do_5_2_6_stale(const struct sctp_endpoint *ep,
84 const struct sctp_association *asoc,
85 const sctp_subtype_t type,
86 void *arg,
87 sctp_cmd_seq_t *commands);
88static sctp_disposition_t sctp_sf_shut_8_4_5(const struct sctp_endpoint *ep,
89 const struct sctp_association *asoc,
90 const sctp_subtype_t type,
91 void *arg,
92 sctp_cmd_seq_t *commands);
Vlad Yasevichece25df2007-09-07 16:30:54 -040093static sctp_disposition_t sctp_sf_tabort_8_4_8(const struct sctp_endpoint *ep,
94 const struct sctp_association *asoc,
95 const sctp_subtype_t type,
96 void *arg,
97 sctp_cmd_seq_t *commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -070098static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk);
99
Adrian Bunk52c1da32005-06-23 22:05:33 -0700100static sctp_disposition_t sctp_stop_t1_and_abort(sctp_cmd_seq_t *commands,
Al Virof94c0192006-11-20 17:00:25 -0800101 __be16 error, int sk_err,
Adrian Bunk52c1da32005-06-23 22:05:33 -0700102 const struct sctp_association *asoc,
103 struct sctp_transport *transport);
104
Wei Yongjunaecedea2007-08-02 16:57:44 +0800105static sctp_disposition_t sctp_sf_abort_violation(
Vlad Yasevichece25df2007-09-07 16:30:54 -0400106 const struct sctp_endpoint *ep,
Wei Yongjunaecedea2007-08-02 16:57:44 +0800107 const struct sctp_association *asoc,
108 void *arg,
109 sctp_cmd_seq_t *commands,
110 const __u8 *payload,
111 const size_t paylen);
112
Adrian Bunk52c1da32005-06-23 22:05:33 -0700113static sctp_disposition_t sctp_sf_violation_chunklen(
114 const struct sctp_endpoint *ep,
115 const struct sctp_association *asoc,
116 const sctp_subtype_t type,
117 void *arg,
118 sctp_cmd_seq_t *commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119
Wei Yongjun6f4c6182007-09-19 17:19:52 +0800120static sctp_disposition_t sctp_sf_violation_paramlen(
121 const struct sctp_endpoint *ep,
122 const struct sctp_association *asoc,
123 const sctp_subtype_t type,
124 void *arg,
125 sctp_cmd_seq_t *commands);
126
Wei Yongjunaecedea2007-08-02 16:57:44 +0800127static sctp_disposition_t sctp_sf_violation_ctsn(
128 const struct sctp_endpoint *ep,
129 const struct sctp_association *asoc,
130 const sctp_subtype_t type,
131 void *arg,
132 sctp_cmd_seq_t *commands);
133
Vlad Yasevichece25df2007-09-07 16:30:54 -0400134static sctp_disposition_t sctp_sf_violation_chunk(
135 const struct sctp_endpoint *ep,
136 const struct sctp_association *asoc,
137 const sctp_subtype_t type,
138 void *arg,
139 sctp_cmd_seq_t *commands);
140
Vlad Yasevichbbd0d592007-10-03 17:51:34 -0700141static sctp_ierror_t sctp_sf_authenticate(const struct sctp_endpoint *ep,
142 const struct sctp_association *asoc,
143 const sctp_subtype_t type,
144 struct sctp_chunk *chunk);
145
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146/* Small helper function that checks if the chunk length
147 * is of the appropriate length. The 'required_length' argument
148 * is set to be the size of a specific chunk we are testing.
149 * Return Values: 1 = Valid length
150 * 0 = Invalid length
151 *
152 */
153static inline int
154sctp_chunk_length_valid(struct sctp_chunk *chunk,
155 __u16 required_length)
156{
157 __u16 chunk_length = ntohs(chunk->chunk_hdr->length);
158
159 if (unlikely(chunk_length < required_length))
160 return 0;
161
162 return 1;
163}
164
165/**********************************************************
166 * These are the state functions for handling chunk events.
167 **********************************************************/
168
169/*
170 * Process the final SHUTDOWN COMPLETE.
171 *
172 * Section: 4 (C) (diagram), 9.2
173 * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify
174 * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be
175 * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint
176 * should stop the T2-shutdown timer and remove all knowledge of the
177 * association (and thus the association enters the CLOSED state).
178 *
Jerome Forissier047a2422005-04-28 11:58:43 -0700179 * Verification Tag: 8.5.1(C), sctpimpguide 2.41.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180 * C) Rules for packet carrying SHUTDOWN COMPLETE:
181 * ...
Jerome Forissier047a2422005-04-28 11:58:43 -0700182 * - The receiver of a SHUTDOWN COMPLETE shall accept the packet
183 * if the Verification Tag field of the packet matches its own tag and
184 * the T bit is not set
185 * OR
186 * it is set to its peer's tag and the T bit is set in the Chunk
187 * Flags.
188 * Otherwise, the receiver MUST silently discard the packet
189 * and take no further action. An endpoint MUST ignore the
190 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191 *
192 * Inputs
193 * (endpoint, asoc, chunk)
194 *
195 * Outputs
196 * (asoc, reply_msg, msg_up, timers, counters)
197 *
198 * The return value is the disposition of the chunk.
199 */
200sctp_disposition_t sctp_sf_do_4_C(const struct sctp_endpoint *ep,
201 const struct sctp_association *asoc,
202 const sctp_subtype_t type,
203 void *arg,
204 sctp_cmd_seq_t *commands)
205{
206 struct sctp_chunk *chunk = arg;
207 struct sctp_ulpevent *ev;
208
Vlad Yasevichece25df2007-09-07 16:30:54 -0400209 if (!sctp_vtag_verify_either(chunk, asoc))
210 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
211
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212 /* RFC 2960 6.10 Bundling
213 *
214 * An endpoint MUST NOT bundle INIT, INIT ACK or
215 * SHUTDOWN COMPLETE with any other chunks.
216 */
217 if (!chunk->singleton)
Vlad Yasevichece25df2007-09-07 16:30:54 -0400218 return sctp_sf_violation_chunk(ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219
Vlad Yasevichece25df2007-09-07 16:30:54 -0400220 /* Make sure that the SHUTDOWN_COMPLETE chunk has a valid length. */
221 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
222 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
223 commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224
225 /* RFC 2960 10.2 SCTP-to-ULP
226 *
227 * H) SHUTDOWN COMPLETE notification
228 *
229 * When SCTP completes the shutdown procedures (section 9.2) this
230 * notification is passed to the upper layer.
231 */
232 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
Vlad Yasevicha5a35e72007-03-23 11:34:08 -0700233 0, 0, 0, NULL, GFP_ATOMIC);
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700234 if (ev)
235 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900236 SCTP_ULPEVENT(ev));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237
238 /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint
239 * will verify that it is in SHUTDOWN-ACK-SENT state, if it is
240 * not the chunk should be discarded. If the endpoint is in
241 * the SHUTDOWN-ACK-SENT state the endpoint should stop the
242 * T2-shutdown timer and remove all knowledge of the
243 * association (and thus the association enters the CLOSED
244 * state).
245 */
246 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
247 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
248
249 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
250 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
251
252 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
253 SCTP_STATE(SCTP_STATE_CLOSED));
254
255 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
256 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
257
258 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
259
260 return SCTP_DISPOSITION_DELETE_TCB;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261}
262
263/*
264 * Respond to a normal INIT chunk.
265 * We are the side that is being asked for an association.
266 *
267 * Section: 5.1 Normal Establishment of an Association, B
268 * B) "Z" shall respond immediately with an INIT ACK chunk. The
269 * destination IP address of the INIT ACK MUST be set to the source
270 * IP address of the INIT to which this INIT ACK is responding. In
271 * the response, besides filling in other parameters, "Z" must set the
272 * Verification Tag field to Tag_A, and also provide its own
273 * Verification Tag (Tag_Z) in the Initiate Tag field.
274 *
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900275 * Verification Tag: Must be 0.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276 *
277 * Inputs
278 * (endpoint, asoc, chunk)
279 *
280 * Outputs
281 * (asoc, reply_msg, msg_up, timers, counters)
282 *
283 * The return value is the disposition of the chunk.
284 */
285sctp_disposition_t sctp_sf_do_5_1B_init(const struct sctp_endpoint *ep,
286 const struct sctp_association *asoc,
287 const sctp_subtype_t type,
288 void *arg,
289 sctp_cmd_seq_t *commands)
290{
291 struct sctp_chunk *chunk = arg;
292 struct sctp_chunk *repl;
293 struct sctp_association *new_asoc;
294 struct sctp_chunk *err_chunk;
295 struct sctp_packet *packet;
296 sctp_unrecognized_param_t *unk_param;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297 int len;
298
299 /* 6.10 Bundling
300 * An endpoint MUST NOT bundle INIT, INIT ACK or
301 * SHUTDOWN COMPLETE with any other chunks.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900302 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303 * IG Section 2.11.2
304 * Furthermore, we require that the receiver of an INIT chunk MUST
305 * enforce these rules by silently discarding an arriving packet
306 * with an INIT chunk that is bundled with other chunks.
307 */
308 if (!chunk->singleton)
309 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
310
311 /* If the packet is an OOTB packet which is temporarily on the
312 * control endpoint, respond with an ABORT.
313 */
314 if (ep == sctp_sk((sctp_get_ctl_sock()))->ep)
315 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
316
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900318 * Tag.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319 */
320 if (chunk->sctp_hdr->vtag != 0)
321 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
322
323 /* Make sure that the INIT chunk has a valid length.
324 * Normally, this would cause an ABORT with a Protocol Violation
325 * error, but since we don't have an association, we'll
326 * just discard the packet.
327 */
328 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
329 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
330
331 /* Verify the INIT chunk before processing it. */
332 err_chunk = NULL;
333 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
334 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
335 &err_chunk)) {
336 /* This chunk contains fatal error. It is to be discarded.
337 * Send an ABORT, with causes if there is any.
338 */
339 if (err_chunk) {
340 packet = sctp_abort_pkt_new(ep, asoc, arg,
341 (__u8 *)(err_chunk->chunk_hdr) +
342 sizeof(sctp_chunkhdr_t),
343 ntohs(err_chunk->chunk_hdr->length) -
344 sizeof(sctp_chunkhdr_t));
345
346 sctp_chunk_free(err_chunk);
347
348 if (packet) {
349 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
350 SCTP_PACKET(packet));
351 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
352 return SCTP_DISPOSITION_CONSUME;
353 } else {
354 return SCTP_DISPOSITION_NOMEM;
355 }
356 } else {
357 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg,
358 commands);
359 }
360 }
361
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900362 /* Grab the INIT header. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363 chunk->subh.init_hdr = (sctp_inithdr_t *)chunk->skb->data;
364
365 /* Tag the variable length parameters. */
366 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
367
368 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
369 if (!new_asoc)
370 goto nomem;
371
372 /* The call, sctp_process_init(), can fail on memory allocation. */
373 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
374 sctp_source(chunk),
375 (sctp_init_chunk_t *)chunk->chunk_hdr,
376 GFP_ATOMIC))
377 goto nomem_init;
378
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
380
381 /* If there are errors need to be reported for unknown parameters,
382 * make sure to reserve enough room in the INIT ACK for them.
383 */
384 len = 0;
385 if (err_chunk)
386 len = ntohs(err_chunk->chunk_hdr->length) -
387 sizeof(sctp_chunkhdr_t);
388
389 if (sctp_assoc_set_bind_addr_from_ep(new_asoc, GFP_ATOMIC) < 0)
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700390 goto nomem_init;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391
392 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
393 if (!repl)
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700394 goto nomem_init;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395
396 /* If there are errors need to be reported for unknown parameters,
397 * include them in the outgoing INIT ACK as "Unrecognized parameter"
398 * parameter.
399 */
400 if (err_chunk) {
401 /* Get the "Unrecognized parameter" parameter(s) out of the
402 * ERROR chunk generated by sctp_verify_init(). Since the
403 * error cause code for "unknown parameter" and the
404 * "Unrecognized parameter" type is the same, we can
405 * construct the parameters in INIT ACK by copying the
406 * ERROR causes over.
407 */
408 unk_param = (sctp_unrecognized_param_t *)
409 ((__u8 *)(err_chunk->chunk_hdr) +
410 sizeof(sctp_chunkhdr_t));
411 /* Replace the cause code with the "Unrecognized parameter"
412 * parameter type.
413 */
414 sctp_addto_chunk(repl, len, unk_param);
415 sctp_chunk_free(err_chunk);
416 }
417
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700418 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
419
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
421
422 /*
423 * Note: After sending out INIT ACK with the State Cookie parameter,
424 * "Z" MUST NOT allocate any resources, nor keep any states for the
425 * new association. Otherwise, "Z" will be vulnerable to resource
426 * attacks.
427 */
428 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
429
430 return SCTP_DISPOSITION_DELETE_TCB;
431
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432nomem_init:
433 sctp_association_free(new_asoc);
434nomem:
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700435 if (err_chunk)
436 sctp_chunk_free(err_chunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437 return SCTP_DISPOSITION_NOMEM;
438}
439
440/*
441 * Respond to a normal INIT ACK chunk.
442 * We are the side that is initiating the association.
443 *
444 * Section: 5.1 Normal Establishment of an Association, C
445 * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init
446 * timer and leave COOKIE-WAIT state. "A" shall then send the State
447 * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start
448 * the T1-cookie timer, and enter the COOKIE-ECHOED state.
449 *
450 * Note: The COOKIE ECHO chunk can be bundled with any pending outbound
451 * DATA chunks, but it MUST be the first chunk in the packet and
452 * until the COOKIE ACK is returned the sender MUST NOT send any
453 * other packets to the peer.
454 *
455 * Verification Tag: 3.3.3
456 * If the value of the Initiate Tag in a received INIT ACK chunk is
457 * found to be 0, the receiver MUST treat it as an error and close the
458 * association by transmitting an ABORT.
459 *
460 * Inputs
461 * (endpoint, asoc, chunk)
462 *
463 * Outputs
464 * (asoc, reply_msg, msg_up, timers, counters)
465 *
466 * The return value is the disposition of the chunk.
467 */
468sctp_disposition_t sctp_sf_do_5_1C_ack(const struct sctp_endpoint *ep,
469 const struct sctp_association *asoc,
470 const sctp_subtype_t type,
471 void *arg,
472 sctp_cmd_seq_t *commands)
473{
474 struct sctp_chunk *chunk = arg;
475 sctp_init_chunk_t *initchunk;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476 struct sctp_chunk *err_chunk;
477 struct sctp_packet *packet;
Al Virof94c0192006-11-20 17:00:25 -0800478 sctp_error_t error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479
480 if (!sctp_vtag_verify(chunk, asoc))
481 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
482
Linus Torvalds1da177e2005-04-16 15:20:36 -0700483 /* 6.10 Bundling
484 * An endpoint MUST NOT bundle INIT, INIT ACK or
485 * SHUTDOWN COMPLETE with any other chunks.
486 */
487 if (!chunk->singleton)
Vlad Yasevichece25df2007-09-07 16:30:54 -0400488 return sctp_sf_violation_chunk(ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489
Vlad Yasevichece25df2007-09-07 16:30:54 -0400490 /* Make sure that the INIT-ACK chunk has a valid length */
491 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_initack_chunk_t)))
492 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
493 commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494 /* Grab the INIT header. */
495 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
496
Linus Torvalds1da177e2005-04-16 15:20:36 -0700497 /* Verify the INIT chunk before processing it. */
498 err_chunk = NULL;
499 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
500 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
501 &err_chunk)) {
502
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503 /* This chunk contains fatal error. It is to be discarded.
504 * Send an ABORT, with causes if there is any.
505 */
506 if (err_chunk) {
507 packet = sctp_abort_pkt_new(ep, asoc, arg,
508 (__u8 *)(err_chunk->chunk_hdr) +
509 sizeof(sctp_chunkhdr_t),
510 ntohs(err_chunk->chunk_hdr->length) -
511 sizeof(sctp_chunkhdr_t));
512
513 sctp_chunk_free(err_chunk);
514
515 if (packet) {
516 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
517 SCTP_PACKET(packet));
518 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700519 error = SCTP_ERROR_INV_PARAM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520 } else {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700521 error = SCTP_ERROR_NO_RESOURCE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522 }
523 } else {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700524 sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
525 error = SCTP_ERROR_INV_PARAM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700526 }
Vlad Yasevichbbd0d592007-10-03 17:51:34 -0700527
528 /* SCTP-AUTH, Section 6.3:
529 * It should be noted that if the receiver wants to tear
530 * down an association in an authenticated way only, the
531 * handling of malformed packets should not result in
532 * tearing down the association.
533 *
534 * This means that if we only want to abort associations
535 * in an authenticated way (i.e AUTH+ABORT), then we
536 * can't destory this association just becuase the packet
537 * was malformed.
538 */
539 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
540 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
541
542 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700543 return sctp_stop_t1_and_abort(commands, error, ECONNREFUSED,
544 asoc, chunk->transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700545 }
546
547 /* Tag the variable length parameters. Note that we never
548 * convert the parameters in an INIT chunk.
549 */
550 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
551
552 initchunk = (sctp_init_chunk_t *) chunk->chunk_hdr;
553
554 sctp_add_cmd_sf(commands, SCTP_CMD_PEER_INIT,
555 SCTP_PEER_INIT(initchunk));
556
Frank Filz3f7a87d2005-06-20 13:14:57 -0700557 /* Reset init error count upon receipt of INIT-ACK. */
558 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
559
Linus Torvalds1da177e2005-04-16 15:20:36 -0700560 /* 5.1 C) "A" shall stop the T1-init timer and leave
561 * COOKIE-WAIT state. "A" shall then ... start the T1-cookie
562 * timer, and enter the COOKIE-ECHOED state.
563 */
564 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
565 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
566 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
567 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
568 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
569 SCTP_STATE(SCTP_STATE_COOKIE_ECHOED));
570
Vlad Yasevich730fc3d2007-09-16 19:32:11 -0700571 /* SCTP-AUTH: genereate the assocition shared keys so that
572 * we can potentially signe the COOKIE-ECHO.
573 */
574 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_SHKEY, SCTP_NULL());
575
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576 /* 5.1 C) "A" shall then send the State Cookie received in the
577 * INIT ACK chunk in a COOKIE ECHO chunk, ...
578 */
579 /* If there is any errors to report, send the ERROR chunk generated
580 * for unknown parameters as well.
581 */
582 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_COOKIE_ECHO,
583 SCTP_CHUNK(err_chunk));
584
585 return SCTP_DISPOSITION_CONSUME;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586}
587
588/*
589 * Respond to a normal COOKIE ECHO chunk.
590 * We are the side that is being asked for an association.
591 *
592 * Section: 5.1 Normal Establishment of an Association, D
593 * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply
594 * with a COOKIE ACK chunk after building a TCB and moving to
595 * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with
596 * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK
597 * chunk MUST be the first chunk in the packet.
598 *
599 * IMPLEMENTATION NOTE: An implementation may choose to send the
600 * Communication Up notification to the SCTP user upon reception
601 * of a valid COOKIE ECHO chunk.
602 *
603 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
604 * D) Rules for packet carrying a COOKIE ECHO
605 *
606 * - When sending a COOKIE ECHO, the endpoint MUST use the value of the
607 * Initial Tag received in the INIT ACK.
608 *
609 * - The receiver of a COOKIE ECHO follows the procedures in Section 5.
610 *
611 * Inputs
612 * (endpoint, asoc, chunk)
613 *
614 * Outputs
615 * (asoc, reply_msg, msg_up, timers, counters)
616 *
617 * The return value is the disposition of the chunk.
618 */
619sctp_disposition_t sctp_sf_do_5_1D_ce(const struct sctp_endpoint *ep,
620 const struct sctp_association *asoc,
621 const sctp_subtype_t type, void *arg,
622 sctp_cmd_seq_t *commands)
623{
624 struct sctp_chunk *chunk = arg;
625 struct sctp_association *new_asoc;
626 sctp_init_chunk_t *peer_init;
627 struct sctp_chunk *repl;
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700628 struct sctp_ulpevent *ev, *ai_ev = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629 int error = 0;
630 struct sctp_chunk *err_chk_p;
Vlad Yasevich609ee462007-08-31 03:10:59 +0900631 struct sock *sk;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632
633 /* If the packet is an OOTB packet which is temporarily on the
634 * control endpoint, respond with an ABORT.
635 */
636 if (ep == sctp_sk((sctp_get_ctl_sock()))->ep)
Vlad Yasevichece25df2007-09-07 16:30:54 -0400637 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700638
639 /* Make sure that the COOKIE_ECHO chunk has a valid length.
640 * In this case, we check that we have enough for at least a
641 * chunk header. More detailed verification is done
642 * in sctp_unpack_cookie().
643 */
644 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
645 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
646
Vlad Yasevich609ee462007-08-31 03:10:59 +0900647 /* If the endpoint is not listening or if the number of associations
648 * on the TCP-style socket exceed the max backlog, respond with an
649 * ABORT.
650 */
651 sk = ep->base.sk;
652 if (!sctp_sstate(sk, LISTENING) ||
653 (sctp_style(sk, TCP) && sk_acceptq_is_full(sk)))
654 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
655
Linus Torvalds1da177e2005-04-16 15:20:36 -0700656 /* "Decode" the chunk. We have no optional parameters so we
657 * are in good shape.
658 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900659 chunk->subh.cookie_hdr =
Linus Torvalds1da177e2005-04-16 15:20:36 -0700660 (struct sctp_signed_cookie *)chunk->skb->data;
Sridhar Samudrala62b08082006-05-05 17:04:43 -0700661 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
662 sizeof(sctp_chunkhdr_t)))
663 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700664
665 /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
666 * "Z" will reply with a COOKIE ACK chunk after building a TCB
667 * and moving to the ESTABLISHED state.
668 */
669 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
670 &err_chk_p);
671
672 /* FIXME:
673 * If the re-build failed, what is the proper error path
674 * from here?
675 *
676 * [We should abort the association. --piggy]
677 */
678 if (!new_asoc) {
679 /* FIXME: Several errors are possible. A bad cookie should
680 * be silently discarded, but think about logging it too.
681 */
682 switch (error) {
683 case -SCTP_IERROR_NOMEM:
684 goto nomem;
685
686 case -SCTP_IERROR_STALE_COOKIE:
687 sctp_send_stale_cookie_err(ep, asoc, chunk, commands,
688 err_chk_p);
689 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
690
691 case -SCTP_IERROR_BAD_SIG:
692 default:
693 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700694 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695 }
696
Linus Torvalds1da177e2005-04-16 15:20:36 -0700697
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700698 /* Delay state machine commands until later.
699 *
700 * Re-build the bind address for the association is done in
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701 * the sctp_unpack_cookie() already.
702 */
703 /* This is a brand-new association, so these are not yet side
704 * effects--it is safe to run them here.
705 */
706 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
707
708 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
Al Viro6a1e5f32006-11-20 17:12:25 -0800709 &chunk->subh.cookie_hdr->c.peer_addr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700710 peer_init, GFP_ATOMIC))
711 goto nomem_init;
712
Vlad Yasevich730fc3d2007-09-16 19:32:11 -0700713 /* SCTP-AUTH: Now that we've populate required fields in
714 * sctp_process_init, set up the assocaition shared keys as
715 * necessary so that we can potentially authenticate the ACK
716 */
717 error = sctp_auth_asoc_init_active_key(new_asoc, GFP_ATOMIC);
718 if (error)
719 goto nomem_init;
720
Vlad Yasevichbbd0d592007-10-03 17:51:34 -0700721 /* SCTP-AUTH: auth_chunk pointer is only set when the cookie-echo
722 * is supposed to be authenticated and we have to do delayed
723 * authentication. We've just recreated the association using
724 * the information in the cookie and now it's much easier to
725 * do the authentication.
726 */
727 if (chunk->auth_chunk) {
728 struct sctp_chunk auth;
729 sctp_ierror_t ret;
730
731 /* set-up our fake chunk so that we can process it */
732 auth.skb = chunk->auth_chunk;
733 auth.asoc = chunk->asoc;
734 auth.sctp_hdr = chunk->sctp_hdr;
735 auth.chunk_hdr = (sctp_chunkhdr_t *)skb_push(chunk->auth_chunk,
736 sizeof(sctp_chunkhdr_t));
737 skb_pull(chunk->auth_chunk, sizeof(sctp_chunkhdr_t));
738 auth.transport = chunk->transport;
739
740 ret = sctp_sf_authenticate(ep, new_asoc, type, &auth);
741
742 /* We can now safely free the auth_chunk clone */
743 kfree_skb(chunk->auth_chunk);
744
745 if (ret != SCTP_IERROR_NO_ERROR) {
746 sctp_association_free(new_asoc);
747 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
748 }
749 }
750
Linus Torvalds1da177e2005-04-16 15:20:36 -0700751 repl = sctp_make_cookie_ack(new_asoc, chunk);
752 if (!repl)
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700753 goto nomem_init;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754
755 /* RFC 2960 5.1 Normal Establishment of an Association
756 *
757 * D) IMPLEMENTATION NOTE: An implementation may choose to
758 * send the Communication Up notification to the SCTP user
759 * upon reception of a valid COOKIE ECHO chunk.
760 */
761 ev = sctp_ulpevent_make_assoc_change(new_asoc, 0, SCTP_COMM_UP, 0,
762 new_asoc->c.sinit_num_ostreams,
763 new_asoc->c.sinit_max_instreams,
Vlad Yasevicha5a35e72007-03-23 11:34:08 -0700764 NULL, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765 if (!ev)
766 goto nomem_ev;
767
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900768 /* Sockets API Draft Section 5.3.1.6
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -0800769 * When a peer sends a Adaptation Layer Indication parameter , SCTP
Linus Torvalds1da177e2005-04-16 15:20:36 -0700770 * delivers this notification to inform the application that of the
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -0800771 * peers requested adaptation layer.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700772 */
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -0800773 if (new_asoc->peer.adaptation_ind) {
774 ai_ev = sctp_ulpevent_make_adaptation_indication(new_asoc,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700775 GFP_ATOMIC);
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700776 if (!ai_ev)
777 goto nomem_aiev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700778 }
779
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700780 /* Add all the state machine commands now since we've created
781 * everything. This way we don't introduce memory corruptions
782 * during side-effect processing and correclty count established
783 * associations.
784 */
785 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
786 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
787 SCTP_STATE(SCTP_STATE_ESTABLISHED));
788 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
789 SCTP_INC_STATS(SCTP_MIB_PASSIVEESTABS);
790 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
791
792 if (new_asoc->autoclose)
793 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
794 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
795
796 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
797
798 /* This will send the COOKIE ACK */
799 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
800
801 /* Queue the ASSOC_CHANGE event */
802 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
803
804 /* Send up the Adaptation Layer Indication event */
805 if (ai_ev)
806 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
807 SCTP_ULPEVENT(ai_ev));
808
Linus Torvalds1da177e2005-04-16 15:20:36 -0700809 return SCTP_DISPOSITION_CONSUME;
810
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700811nomem_aiev:
812 sctp_ulpevent_free(ev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700813nomem_ev:
814 sctp_chunk_free(repl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700815nomem_init:
816 sctp_association_free(new_asoc);
817nomem:
818 return SCTP_DISPOSITION_NOMEM;
819}
820
821/*
822 * Respond to a normal COOKIE ACK chunk.
823 * We are the side that is being asked for an association.
824 *
825 * RFC 2960 5.1 Normal Establishment of an Association
826 *
827 * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the
828 * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie
829 * timer. It may also notify its ULP about the successful
830 * establishment of the association with a Communication Up
831 * notification (see Section 10).
832 *
833 * Verification Tag:
834 * Inputs
835 * (endpoint, asoc, chunk)
836 *
837 * Outputs
838 * (asoc, reply_msg, msg_up, timers, counters)
839 *
840 * The return value is the disposition of the chunk.
841 */
842sctp_disposition_t sctp_sf_do_5_1E_ca(const struct sctp_endpoint *ep,
843 const struct sctp_association *asoc,
844 const sctp_subtype_t type, void *arg,
845 sctp_cmd_seq_t *commands)
846{
847 struct sctp_chunk *chunk = arg;
848 struct sctp_ulpevent *ev;
849
850 if (!sctp_vtag_verify(chunk, asoc))
851 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
852
853 /* Verify that the chunk length for the COOKIE-ACK is OK.
854 * If we don't do this, any bundled chunks may be junked.
855 */
856 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
857 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
858 commands);
859
860 /* Reset init error count upon receipt of COOKIE-ACK,
861 * to avoid problems with the managemement of this
862 * counter in stale cookie situations when a transition back
863 * from the COOKIE-ECHOED state to the COOKIE-WAIT
864 * state is performed.
865 */
Frank Filz3f7a87d2005-06-20 13:14:57 -0700866 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
Linus Torvalds1da177e2005-04-16 15:20:36 -0700867
868 /* RFC 2960 5.1 Normal Establishment of an Association
869 *
870 * E) Upon reception of the COOKIE ACK, endpoint "A" will move
871 * from the COOKIE-ECHOED state to the ESTABLISHED state,
872 * stopping the T1-cookie timer.
873 */
874 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
875 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
876 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
877 SCTP_STATE(SCTP_STATE_ESTABLISHED));
878 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
879 SCTP_INC_STATS(SCTP_MIB_ACTIVEESTABS);
880 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
881 if (asoc->autoclose)
882 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
883 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
884 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
885
886 /* It may also notify its ULP about the successful
887 * establishment of the association with a Communication Up
888 * notification (see Section 10).
889 */
890 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP,
891 0, asoc->c.sinit_num_ostreams,
892 asoc->c.sinit_max_instreams,
Vlad Yasevicha5a35e72007-03-23 11:34:08 -0700893 NULL, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700894
895 if (!ev)
896 goto nomem;
897
898 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
899
900 /* Sockets API Draft Section 5.3.1.6
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -0800901 * When a peer sends a Adaptation Layer Indication parameter , SCTP
Linus Torvalds1da177e2005-04-16 15:20:36 -0700902 * delivers this notification to inform the application that of the
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -0800903 * peers requested adaptation layer.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700904 */
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -0800905 if (asoc->peer.adaptation_ind) {
906 ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700907 if (!ev)
908 goto nomem;
909
910 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
911 SCTP_ULPEVENT(ev));
912 }
913
914 return SCTP_DISPOSITION_CONSUME;
915nomem:
916 return SCTP_DISPOSITION_NOMEM;
917}
918
919/* Generate and sendout a heartbeat packet. */
920static sctp_disposition_t sctp_sf_heartbeat(const struct sctp_endpoint *ep,
921 const struct sctp_association *asoc,
922 const sctp_subtype_t type,
923 void *arg,
924 sctp_cmd_seq_t *commands)
925{
926 struct sctp_transport *transport = (struct sctp_transport *) arg;
927 struct sctp_chunk *reply;
928 sctp_sender_hb_info_t hbinfo;
929 size_t paylen = 0;
930
931 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO;
932 hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t));
Al Viro63de08f2006-11-20 17:07:25 -0800933 hbinfo.daddr = transport->ipaddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700934 hbinfo.sent_at = jiffies;
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700935 hbinfo.hb_nonce = transport->hb_nonce;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700936
937 /* Send a heartbeat to our peer. */
938 paylen = sizeof(sctp_sender_hb_info_t);
939 reply = sctp_make_heartbeat(asoc, transport, &hbinfo, paylen);
940 if (!reply)
941 return SCTP_DISPOSITION_NOMEM;
942
943 /* Set rto_pending indicating that an RTT measurement
944 * is started with this heartbeat chunk.
945 */
946 sctp_add_cmd_sf(commands, SCTP_CMD_RTO_PENDING,
947 SCTP_TRANSPORT(transport));
948
949 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
950 return SCTP_DISPOSITION_CONSUME;
951}
952
953/* Generate a HEARTBEAT packet on the given transport. */
954sctp_disposition_t sctp_sf_sendbeat_8_3(const struct sctp_endpoint *ep,
955 const struct sctp_association *asoc,
956 const sctp_subtype_t type,
957 void *arg,
958 sctp_cmd_seq_t *commands)
959{
960 struct sctp_transport *transport = (struct sctp_transport *) arg;
961
Vlad Yaseviche2c2fc22006-01-30 16:00:40 -0800962 if (asoc->overall_error_count >= asoc->max_retrans) {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700963 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
964 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700965 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
966 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -0800967 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700968 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
969 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
970 return SCTP_DISPOSITION_DELETE_TCB;
971 }
972
973 /* Section 3.3.5.
974 * The Sender-specific Heartbeat Info field should normally include
975 * information about the sender's current time when this HEARTBEAT
976 * chunk is sent and the destination transport address to which this
977 * HEARTBEAT is sent (see Section 8.3).
978 */
979
Frank Filz52ccb8e2005-12-22 11:36:46 -0800980 if (transport->param_flags & SPP_HB_ENABLE) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700981 if (SCTP_DISPOSITION_NOMEM ==
982 sctp_sf_heartbeat(ep, asoc, type, arg,
983 commands))
984 return SCTP_DISPOSITION_NOMEM;
985 /* Set transport error counter and association error counter
986 * when sending heartbeat.
987 */
988 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_RESET,
989 SCTP_TRANSPORT(transport));
990 }
991 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMER_UPDATE,
992 SCTP_TRANSPORT(transport));
993
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900994 return SCTP_DISPOSITION_CONSUME;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700995}
996
997/*
998 * Process an heartbeat request.
999 *
1000 * Section: 8.3 Path Heartbeat
1001 * The receiver of the HEARTBEAT should immediately respond with a
1002 * HEARTBEAT ACK that contains the Heartbeat Information field copied
1003 * from the received HEARTBEAT chunk.
1004 *
1005 * Verification Tag: 8.5 Verification Tag [Normal verification]
1006 * When receiving an SCTP packet, the endpoint MUST ensure that the
1007 * value in the Verification Tag field of the received SCTP packet
1008 * matches its own Tag. If the received Verification Tag value does not
1009 * match the receiver's own tag value, the receiver shall silently
1010 * discard the packet and shall not process it any further except for
1011 * those cases listed in Section 8.5.1 below.
1012 *
1013 * Inputs
1014 * (endpoint, asoc, chunk)
1015 *
1016 * Outputs
1017 * (asoc, reply_msg, msg_up, timers, counters)
1018 *
1019 * The return value is the disposition of the chunk.
1020 */
1021sctp_disposition_t sctp_sf_beat_8_3(const struct sctp_endpoint *ep,
1022 const struct sctp_association *asoc,
1023 const sctp_subtype_t type,
1024 void *arg,
1025 sctp_cmd_seq_t *commands)
1026{
1027 struct sctp_chunk *chunk = arg;
1028 struct sctp_chunk *reply;
1029 size_t paylen = 0;
1030
1031 if (!sctp_vtag_verify(chunk, asoc))
1032 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1033
1034 /* Make sure that the HEARTBEAT chunk has a valid length. */
1035 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t)))
1036 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1037 commands);
1038
1039 /* 8.3 The receiver of the HEARTBEAT should immediately
1040 * respond with a HEARTBEAT ACK that contains the Heartbeat
1041 * Information field copied from the received HEARTBEAT chunk.
1042 */
1043 chunk->subh.hb_hdr = (sctp_heartbeathdr_t *) chunk->skb->data;
1044 paylen = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
Sridhar Samudrala62b08082006-05-05 17:04:43 -07001045 if (!pskb_pull(chunk->skb, paylen))
1046 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001047
1048 reply = sctp_make_heartbeat_ack(asoc, chunk,
1049 chunk->subh.hb_hdr, paylen);
1050 if (!reply)
1051 goto nomem;
1052
1053 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
1054 return SCTP_DISPOSITION_CONSUME;
1055
1056nomem:
1057 return SCTP_DISPOSITION_NOMEM;
1058}
1059
1060/*
1061 * Process the returning HEARTBEAT ACK.
1062 *
1063 * Section: 8.3 Path Heartbeat
1064 * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT
1065 * should clear the error counter of the destination transport
1066 * address to which the HEARTBEAT was sent, and mark the destination
1067 * transport address as active if it is not so marked. The endpoint may
1068 * optionally report to the upper layer when an inactive destination
1069 * address is marked as active due to the reception of the latest
1070 * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also
1071 * clear the association overall error count as well (as defined
1072 * in section 8.1).
1073 *
1074 * The receiver of the HEARTBEAT ACK should also perform an RTT
1075 * measurement for that destination transport address using the time
1076 * value carried in the HEARTBEAT ACK chunk.
1077 *
1078 * Verification Tag: 8.5 Verification Tag [Normal verification]
1079 *
1080 * Inputs
1081 * (endpoint, asoc, chunk)
1082 *
1083 * Outputs
1084 * (asoc, reply_msg, msg_up, timers, counters)
1085 *
1086 * The return value is the disposition of the chunk.
1087 */
1088sctp_disposition_t sctp_sf_backbeat_8_3(const struct sctp_endpoint *ep,
1089 const struct sctp_association *asoc,
1090 const sctp_subtype_t type,
1091 void *arg,
1092 sctp_cmd_seq_t *commands)
1093{
1094 struct sctp_chunk *chunk = arg;
1095 union sctp_addr from_addr;
1096 struct sctp_transport *link;
1097 sctp_sender_hb_info_t *hbinfo;
1098 unsigned long max_interval;
1099
1100 if (!sctp_vtag_verify(chunk, asoc))
1101 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1102
1103 /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */
1104 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t)))
1105 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1106 commands);
1107
1108 hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
Vladislav Yasevicha6012662006-05-19 14:25:53 -07001109 /* Make sure that the length of the parameter is what we expect */
1110 if (ntohs(hbinfo->param_hdr.length) !=
1111 sizeof(sctp_sender_hb_info_t)) {
1112 return SCTP_DISPOSITION_DISCARD;
1113 }
1114
Linus Torvalds1da177e2005-04-16 15:20:36 -07001115 from_addr = hbinfo->daddr;
Al Viro63de08f2006-11-20 17:07:25 -08001116 link = sctp_assoc_lookup_paddr(asoc, &from_addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001117
1118 /* This should never happen, but lets log it if so. */
Frank Filz3f7a87d2005-06-20 13:14:57 -07001119 if (unlikely(!link)) {
1120 if (from_addr.sa.sa_family == AF_INET6) {
Wei Yongjund99fa422007-08-27 11:19:24 +08001121 if (net_ratelimit())
1122 printk(KERN_WARNING
1123 "%s association %p could not find address "
1124 NIP6_FMT "\n",
1125 __FUNCTION__,
1126 asoc,
1127 NIP6(from_addr.v6.sin6_addr));
Frank Filz3f7a87d2005-06-20 13:14:57 -07001128 } else {
Wei Yongjund99fa422007-08-27 11:19:24 +08001129 if (net_ratelimit())
1130 printk(KERN_WARNING
1131 "%s association %p could not find address "
1132 NIPQUAD_FMT "\n",
1133 __FUNCTION__,
1134 asoc,
1135 NIPQUAD(from_addr.v4.sin_addr.s_addr));
Frank Filz3f7a87d2005-06-20 13:14:57 -07001136 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001137 return SCTP_DISPOSITION_DISCARD;
1138 }
1139
Sridhar Samudralaad8fec12006-07-21 14:48:50 -07001140 /* Validate the 64-bit random nonce. */
1141 if (hbinfo->hb_nonce != link->hb_nonce)
1142 return SCTP_DISPOSITION_DISCARD;
1143
Frank Filz52ccb8e2005-12-22 11:36:46 -08001144 max_interval = link->hbinterval + link->rto;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001145
1146 /* Check if the timestamp looks valid. */
1147 if (time_after(hbinfo->sent_at, jiffies) ||
1148 time_after(jiffies, hbinfo->sent_at + max_interval)) {
1149 SCTP_DEBUG_PRINTK("%s: HEARTBEAT ACK with invalid timestamp"
1150 "received for transport: %p\n",
1151 __FUNCTION__, link);
1152 return SCTP_DISPOSITION_DISCARD;
1153 }
1154
1155 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of
1156 * the HEARTBEAT should clear the error counter of the
1157 * destination transport address to which the HEARTBEAT was
1158 * sent and mark the destination transport address as active if
1159 * it is not so marked.
1160 */
1161 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_ON, SCTP_TRANSPORT(link));
1162
1163 return SCTP_DISPOSITION_CONSUME;
1164}
1165
1166/* Helper function to send out an abort for the restart
1167 * condition.
1168 */
1169static int sctp_sf_send_restart_abort(union sctp_addr *ssa,
1170 struct sctp_chunk *init,
1171 sctp_cmd_seq_t *commands)
1172{
1173 int len;
1174 struct sctp_packet *pkt;
1175 union sctp_addr_param *addrparm;
1176 struct sctp_errhdr *errhdr;
1177 struct sctp_endpoint *ep;
1178 char buffer[sizeof(struct sctp_errhdr)+sizeof(union sctp_addr_param)];
1179 struct sctp_af *af = sctp_get_af_specific(ssa->v4.sin_family);
1180
1181 /* Build the error on the stack. We are way to malloc crazy
1182 * throughout the code today.
1183 */
1184 errhdr = (struct sctp_errhdr *)buffer;
1185 addrparm = (union sctp_addr_param *)errhdr->variable;
1186
1187 /* Copy into a parm format. */
1188 len = af->to_addr_param(ssa, addrparm);
1189 len += sizeof(sctp_errhdr_t);
1190
1191 errhdr->cause = SCTP_ERROR_RESTART;
1192 errhdr->length = htons(len);
1193
1194 /* Assign to the control socket. */
1195 ep = sctp_sk((sctp_get_ctl_sock()))->ep;
1196
1197 /* Association is NULL since this may be a restart attack and we
1198 * want to send back the attacker's vtag.
1199 */
1200 pkt = sctp_abort_pkt_new(ep, NULL, init, errhdr, len);
1201
1202 if (!pkt)
1203 goto out;
1204 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, SCTP_PACKET(pkt));
1205
1206 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
1207
1208 /* Discard the rest of the inbound packet. */
1209 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
1210
1211out:
1212 /* Even if there is no memory, treat as a failure so
1213 * the packet will get dropped.
1214 */
1215 return 0;
1216}
1217
1218/* A restart is occurring, check to make sure no new addresses
1219 * are being added as we may be under a takeover attack.
1220 */
1221static int sctp_sf_check_restart_addrs(const struct sctp_association *new_asoc,
1222 const struct sctp_association *asoc,
1223 struct sctp_chunk *init,
1224 sctp_cmd_seq_t *commands)
1225{
1226 struct sctp_transport *new_addr, *addr;
1227 struct list_head *pos, *pos2;
1228 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
1244 list_for_each(pos, &new_asoc->peer.transport_addr_list) {
1245 new_addr = list_entry(pos, struct sctp_transport, transports);
1246 found = 0;
1247 list_for_each(pos2, &asoc->peer.transport_addr_list) {
1248 addr = list_entry(pos2, struct sctp_transport,
1249 transports);
Al Viro5f242a12006-11-20 17:05:23 -08001250 if (sctp_cmp_addr_exact(&new_addr->ipaddr,
1251 &addr->ipaddr)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001252 found = 1;
1253 break;
1254 }
1255 }
1256 if (!found)
1257 break;
1258 }
1259
1260 /* If a new address was added, ABORT the sender. */
1261 if (!found && new_addr) {
Al Viro7dd8a582006-11-20 17:23:25 -08001262 sctp_sf_send_restart_abort(&new_addr->ipaddr, init, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001263 }
1264
1265 /* Return success if all addresses were found. */
1266 return found;
1267}
1268
1269/* Populate the verification/tie tags based on overlapping INIT
1270 * scenario.
1271 *
1272 * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state.
1273 */
1274static void sctp_tietags_populate(struct sctp_association *new_asoc,
1275 const struct sctp_association *asoc)
1276{
1277 switch (asoc->state) {
1278
1279 /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */
1280
1281 case SCTP_STATE_COOKIE_WAIT:
1282 new_asoc->c.my_vtag = asoc->c.my_vtag;
1283 new_asoc->c.my_ttag = asoc->c.my_vtag;
1284 new_asoc->c.peer_ttag = 0;
1285 break;
1286
1287 case SCTP_STATE_COOKIE_ECHOED:
1288 new_asoc->c.my_vtag = asoc->c.my_vtag;
1289 new_asoc->c.my_ttag = asoc->c.my_vtag;
1290 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1291 break;
1292
1293 /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED,
1294 * COOKIE-WAIT and SHUTDOWN-ACK-SENT
1295 */
1296 default:
1297 new_asoc->c.my_ttag = asoc->c.my_vtag;
1298 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1299 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07001300 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001301
1302 /* Other parameters for the endpoint SHOULD be copied from the
1303 * existing parameters of the association (e.g. number of
1304 * outbound streams) into the INIT ACK and cookie.
1305 */
1306 new_asoc->rwnd = asoc->rwnd;
1307 new_asoc->c.sinit_num_ostreams = asoc->c.sinit_num_ostreams;
1308 new_asoc->c.sinit_max_instreams = asoc->c.sinit_max_instreams;
1309 new_asoc->c.initial_tsn = asoc->c.initial_tsn;
1310}
1311
Vlad Yasevich730fc3d2007-09-16 19:32:11 -07001312static void sctp_auth_params_populate(struct sctp_association *new_asoc,
1313 const struct sctp_association *asoc)
1314{
1315 /* Only perform this if AUTH extension is enabled */
1316 if (!sctp_auth_enable)
1317 return;
1318
1319 /* We need to provide the same parameter information as
1320 * was in the original INIT. This means that we need to copy
1321 * the HMACS, CHUNKS, and RANDOM parameter from the original
1322 * assocaition.
1323 */
1324 memcpy(new_asoc->c.auth_random, asoc->c.auth_random,
1325 sizeof(asoc->c.auth_random));
1326 memcpy(new_asoc->c.auth_hmacs, asoc->c.auth_hmacs,
1327 sizeof(asoc->c.auth_hmacs));
1328 memcpy(new_asoc->c.auth_chunks, asoc->c.auth_chunks,
1329 sizeof(asoc->c.auth_chunks));
1330}
1331
Linus Torvalds1da177e2005-04-16 15:20:36 -07001332/*
1333 * Compare vtag/tietag values to determine unexpected COOKIE-ECHO
1334 * handling action.
1335 *
1336 * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists.
1337 *
1338 * Returns value representing action to be taken. These action values
1339 * correspond to Action/Description values in RFC 2960, Table 2.
1340 */
1341static char sctp_tietags_compare(struct sctp_association *new_asoc,
1342 const struct sctp_association *asoc)
1343{
1344 /* In this case, the peer may have restarted. */
1345 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1346 (asoc->c.peer_vtag != new_asoc->c.peer_vtag) &&
1347 (asoc->c.my_vtag == new_asoc->c.my_ttag) &&
1348 (asoc->c.peer_vtag == new_asoc->c.peer_ttag))
1349 return 'A';
1350
1351 /* Collision case B. */
1352 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1353 ((asoc->c.peer_vtag != new_asoc->c.peer_vtag) ||
1354 (0 == asoc->c.peer_vtag))) {
1355 return 'B';
1356 }
1357
1358 /* Collision case D. */
1359 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1360 (asoc->c.peer_vtag == new_asoc->c.peer_vtag))
1361 return 'D';
1362
1363 /* Collision case C. */
1364 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1365 (asoc->c.peer_vtag == new_asoc->c.peer_vtag) &&
1366 (0 == new_asoc->c.my_ttag) &&
1367 (0 == new_asoc->c.peer_ttag))
1368 return 'C';
1369
1370 /* No match to any of the special cases; discard this packet. */
1371 return 'E';
1372}
1373
1374/* Common helper routine for both duplicate and simulataneous INIT
1375 * chunk handling.
1376 */
1377static sctp_disposition_t sctp_sf_do_unexpected_init(
1378 const struct sctp_endpoint *ep,
1379 const struct sctp_association *asoc,
1380 const sctp_subtype_t type,
1381 void *arg, sctp_cmd_seq_t *commands)
1382{
1383 sctp_disposition_t retval;
1384 struct sctp_chunk *chunk = arg;
1385 struct sctp_chunk *repl;
1386 struct sctp_association *new_asoc;
1387 struct sctp_chunk *err_chunk;
1388 struct sctp_packet *packet;
1389 sctp_unrecognized_param_t *unk_param;
1390 int len;
1391
1392 /* 6.10 Bundling
1393 * An endpoint MUST NOT bundle INIT, INIT ACK or
1394 * SHUTDOWN COMPLETE with any other chunks.
1395 *
1396 * IG Section 2.11.2
1397 * Furthermore, we require that the receiver of an INIT chunk MUST
1398 * enforce these rules by silently discarding an arriving packet
1399 * with an INIT chunk that is bundled with other chunks.
1400 */
1401 if (!chunk->singleton)
1402 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1403
1404 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001405 * Tag.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001406 */
1407 if (chunk->sctp_hdr->vtag != 0)
1408 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
1409
1410 /* Make sure that the INIT chunk has a valid length.
1411 * In this case, we generate a protocol violation since we have
1412 * an association established.
1413 */
1414 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
1415 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1416 commands);
1417 /* Grab the INIT header. */
1418 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
1419
1420 /* Tag the variable length parameters. */
1421 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
1422
1423 /* Verify the INIT chunk before processing it. */
1424 err_chunk = NULL;
1425 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
1426 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
1427 &err_chunk)) {
1428 /* This chunk contains fatal error. It is to be discarded.
1429 * Send an ABORT, with causes if there is any.
1430 */
1431 if (err_chunk) {
1432 packet = sctp_abort_pkt_new(ep, asoc, arg,
1433 (__u8 *)(err_chunk->chunk_hdr) +
1434 sizeof(sctp_chunkhdr_t),
1435 ntohs(err_chunk->chunk_hdr->length) -
1436 sizeof(sctp_chunkhdr_t));
1437
1438 if (packet) {
1439 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
1440 SCTP_PACKET(packet));
1441 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
1442 retval = SCTP_DISPOSITION_CONSUME;
1443 } else {
1444 retval = SCTP_DISPOSITION_NOMEM;
1445 }
1446 goto cleanup;
1447 } else {
1448 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg,
1449 commands);
1450 }
1451 }
1452
1453 /*
1454 * Other parameters for the endpoint SHOULD be copied from the
1455 * existing parameters of the association (e.g. number of
1456 * outbound streams) into the INIT ACK and cookie.
1457 * FIXME: We are copying parameters from the endpoint not the
1458 * association.
1459 */
1460 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
1461 if (!new_asoc)
1462 goto nomem;
1463
1464 /* In the outbound INIT ACK the endpoint MUST copy its current
1465 * Verification Tag and Peers Verification tag into a reserved
1466 * place (local tie-tag and per tie-tag) within the state cookie.
1467 */
1468 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
1469 sctp_source(chunk),
1470 (sctp_init_chunk_t *)chunk->chunk_hdr,
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001471 GFP_ATOMIC))
1472 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001473
1474 /* Make sure no new addresses are being added during the
1475 * restart. Do not do this check for COOKIE-WAIT state,
1476 * since there are no peer addresses to check against.
1477 * Upon return an ABORT will have been sent if needed.
1478 */
1479 if (!sctp_state(asoc, COOKIE_WAIT)) {
1480 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk,
1481 commands)) {
1482 retval = SCTP_DISPOSITION_CONSUME;
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001483 goto nomem_retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001484 }
1485 }
1486
1487 sctp_tietags_populate(new_asoc, asoc);
1488
Vlad Yasevich730fc3d2007-09-16 19:32:11 -07001489 sctp_auth_params_populate(new_asoc, asoc);
1490
Linus Torvalds1da177e2005-04-16 15:20:36 -07001491 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
1492
1493 /* If there are errors need to be reported for unknown parameters,
1494 * make sure to reserve enough room in the INIT ACK for them.
1495 */
1496 len = 0;
1497 if (err_chunk) {
1498 len = ntohs(err_chunk->chunk_hdr->length) -
1499 sizeof(sctp_chunkhdr_t);
1500 }
1501
1502 if (sctp_assoc_set_bind_addr_from_ep(new_asoc, GFP_ATOMIC) < 0)
1503 goto nomem;
1504
1505 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
1506 if (!repl)
1507 goto nomem;
1508
1509 /* If there are errors need to be reported for unknown parameters,
1510 * include them in the outgoing INIT ACK as "Unrecognized parameter"
1511 * parameter.
1512 */
1513 if (err_chunk) {
1514 /* Get the "Unrecognized parameter" parameter(s) out of the
1515 * ERROR chunk generated by sctp_verify_init(). Since the
1516 * error cause code for "unknown parameter" and the
1517 * "Unrecognized parameter" type is the same, we can
1518 * construct the parameters in INIT ACK by copying the
1519 * ERROR causes over.
1520 */
1521 unk_param = (sctp_unrecognized_param_t *)
1522 ((__u8 *)(err_chunk->chunk_hdr) +
1523 sizeof(sctp_chunkhdr_t));
1524 /* Replace the cause code with the "Unrecognized parameter"
1525 * parameter type.
1526 */
1527 sctp_addto_chunk(repl, len, unk_param);
1528 }
1529
1530 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
1531 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1532
1533 /*
1534 * Note: After sending out INIT ACK with the State Cookie parameter,
1535 * "Z" MUST NOT allocate any resources for this new association.
1536 * Otherwise, "Z" will be vulnerable to resource attacks.
1537 */
1538 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
1539 retval = SCTP_DISPOSITION_CONSUME;
1540
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001541 return retval;
1542
1543nomem:
1544 retval = SCTP_DISPOSITION_NOMEM;
1545nomem_retval:
1546 if (new_asoc)
1547 sctp_association_free(new_asoc);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001548cleanup:
1549 if (err_chunk)
1550 sctp_chunk_free(err_chunk);
1551 return retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001552}
1553
1554/*
1555 * Handle simultanous INIT.
1556 * This means we started an INIT and then we got an INIT request from
1557 * our peer.
1558 *
1559 * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B)
1560 * This usually indicates an initialization collision, i.e., each
1561 * endpoint is attempting, at about the same time, to establish an
1562 * association with the other endpoint.
1563 *
1564 * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an
1565 * endpoint MUST respond with an INIT ACK using the same parameters it
1566 * sent in its original INIT chunk (including its Verification Tag,
1567 * unchanged). These original parameters are combined with those from the
1568 * newly received INIT chunk. The endpoint shall also generate a State
1569 * Cookie with the INIT ACK. The endpoint uses the parameters sent in its
1570 * INIT to calculate the State Cookie.
1571 *
1572 * After that, the endpoint MUST NOT change its state, the T1-init
1573 * timer shall be left running and the corresponding TCB MUST NOT be
1574 * destroyed. The normal procedures for handling State Cookies when
1575 * a TCB exists will resolve the duplicate INITs to a single association.
1576 *
1577 * For an endpoint that is in the COOKIE-ECHOED state it MUST populate
1578 * its Tie-Tags with the Tag information of itself and its peer (see
1579 * section 5.2.2 for a description of the Tie-Tags).
1580 *
1581 * Verification Tag: Not explicit, but an INIT can not have a valid
1582 * verification tag, so we skip the check.
1583 *
1584 * Inputs
1585 * (endpoint, asoc, chunk)
1586 *
1587 * Outputs
1588 * (asoc, reply_msg, msg_up, timers, counters)
1589 *
1590 * The return value is the disposition of the chunk.
1591 */
1592sctp_disposition_t sctp_sf_do_5_2_1_siminit(const struct sctp_endpoint *ep,
1593 const struct sctp_association *asoc,
1594 const sctp_subtype_t type,
1595 void *arg,
1596 sctp_cmd_seq_t *commands)
1597{
1598 /* Call helper to do the real work for both simulataneous and
1599 * duplicate INIT chunk handling.
1600 */
1601 return sctp_sf_do_unexpected_init(ep, asoc, type, arg, commands);
1602}
1603
1604/*
1605 * Handle duplicated INIT messages. These are usually delayed
1606 * restransmissions.
1607 *
1608 * Section: 5.2.2 Unexpected INIT in States Other than CLOSED,
1609 * COOKIE-ECHOED and COOKIE-WAIT
1610 *
1611 * Unless otherwise stated, upon reception of an unexpected INIT for
1612 * this association, the endpoint shall generate an INIT ACK with a
1613 * State Cookie. In the outbound INIT ACK the endpoint MUST copy its
1614 * current Verification Tag and peer's Verification Tag into a reserved
1615 * place within the state cookie. We shall refer to these locations as
1616 * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet
1617 * containing this INIT ACK MUST carry a Verification Tag value equal to
1618 * the Initiation Tag found in the unexpected INIT. And the INIT ACK
1619 * MUST contain a new Initiation Tag (randomly generated see Section
1620 * 5.3.1). Other parameters for the endpoint SHOULD be copied from the
1621 * existing parameters of the association (e.g. number of outbound
1622 * streams) into the INIT ACK and cookie.
1623 *
1624 * After sending out the INIT ACK, the endpoint shall take no further
1625 * actions, i.e., the existing association, including its current state,
1626 * and the corresponding TCB MUST NOT be changed.
1627 *
1628 * Note: Only when a TCB exists and the association is not in a COOKIE-
1629 * WAIT state are the Tie-Tags populated. For a normal association INIT
1630 * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be
1631 * set to 0 (indicating that no previous TCB existed). The INIT ACK and
1632 * State Cookie are populated as specified in section 5.2.1.
1633 *
1634 * Verification Tag: Not specified, but an INIT has no way of knowing
1635 * what the verification tag could be, so we ignore it.
1636 *
1637 * Inputs
1638 * (endpoint, asoc, chunk)
1639 *
1640 * Outputs
1641 * (asoc, reply_msg, msg_up, timers, counters)
1642 *
1643 * The return value is the disposition of the chunk.
1644 */
1645sctp_disposition_t sctp_sf_do_5_2_2_dupinit(const struct sctp_endpoint *ep,
1646 const struct sctp_association *asoc,
1647 const sctp_subtype_t type,
1648 void *arg,
1649 sctp_cmd_seq_t *commands)
1650{
1651 /* Call helper to do the real work for both simulataneous and
1652 * duplicate INIT chunk handling.
1653 */
1654 return sctp_sf_do_unexpected_init(ep, asoc, type, arg, commands);
1655}
1656
1657
Vlad Yasevich610ab732007-01-15 19:18:30 -08001658/*
1659 * Unexpected INIT-ACK handler.
1660 *
1661 * Section 5.2.3
1662 * If an INIT ACK received by an endpoint in any state other than the
1663 * COOKIE-WAIT state, the endpoint should discard the INIT ACK chunk.
1664 * An unexpected INIT ACK usually indicates the processing of an old or
1665 * duplicated INIT chunk.
1666*/
1667sctp_disposition_t sctp_sf_do_5_2_3_initack(const struct sctp_endpoint *ep,
1668 const struct sctp_association *asoc,
1669 const sctp_subtype_t type,
1670 void *arg, sctp_cmd_seq_t *commands)
1671{
1672 /* Per the above section, we'll discard the chunk if we have an
1673 * endpoint. If this is an OOTB INIT-ACK, treat it as such.
1674 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001675 if (ep == sctp_sk((sctp_get_ctl_sock()))->ep)
Vlad Yasevich610ab732007-01-15 19:18:30 -08001676 return sctp_sf_ootb(ep, asoc, type, arg, commands);
1677 else
1678 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
1679}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001680
1681/* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A')
1682 *
1683 * Section 5.2.4
1684 * A) In this case, the peer may have restarted.
1685 */
1686static sctp_disposition_t sctp_sf_do_dupcook_a(const struct sctp_endpoint *ep,
1687 const struct sctp_association *asoc,
1688 struct sctp_chunk *chunk,
1689 sctp_cmd_seq_t *commands,
1690 struct sctp_association *new_asoc)
1691{
1692 sctp_init_chunk_t *peer_init;
1693 struct sctp_ulpevent *ev;
1694 struct sctp_chunk *repl;
1695 struct sctp_chunk *err;
1696 sctp_disposition_t disposition;
1697
1698 /* new_asoc is a brand-new association, so these are not yet
1699 * side effects--it is safe to run them here.
1700 */
1701 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1702
1703 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
1704 sctp_source(chunk), peer_init,
1705 GFP_ATOMIC))
1706 goto nomem;
1707
1708 /* Make sure no new addresses are being added during the
1709 * restart. Though this is a pretty complicated attack
1710 * since you'd have to get inside the cookie.
1711 */
1712 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk, commands)) {
1713 return SCTP_DISPOSITION_CONSUME;
1714 }
1715
1716 /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes
1717 * the peer has restarted (Action A), it MUST NOT setup a new
1718 * association but instead resend the SHUTDOWN ACK and send an ERROR
1719 * chunk with a "Cookie Received while Shutting Down" error cause to
1720 * its peer.
1721 */
1722 if (sctp_state(asoc, SHUTDOWN_ACK_SENT)) {
1723 disposition = sctp_sf_do_9_2_reshutack(ep, asoc,
1724 SCTP_ST_CHUNK(chunk->chunk_hdr->type),
1725 chunk, commands);
1726 if (SCTP_DISPOSITION_NOMEM == disposition)
1727 goto nomem;
1728
1729 err = sctp_make_op_error(asoc, chunk,
1730 SCTP_ERROR_COOKIE_IN_SHUTDOWN,
1731 NULL, 0);
1732 if (err)
1733 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1734 SCTP_CHUNK(err));
1735
1736 return SCTP_DISPOSITION_CONSUME;
1737 }
1738
1739 /* For now, fail any unsent/unacked data. Consider the optional
1740 * choice of resending of this data.
1741 */
1742 sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_OUTQUEUE, SCTP_NULL());
1743
Linus Torvalds1da177e2005-04-16 15:20:36 -07001744 repl = sctp_make_cookie_ack(new_asoc, chunk);
1745 if (!repl)
1746 goto nomem;
1747
Linus Torvalds1da177e2005-04-16 15:20:36 -07001748 /* Report association restart to upper layer. */
1749 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_RESTART, 0,
1750 new_asoc->c.sinit_num_ostreams,
1751 new_asoc->c.sinit_max_instreams,
Vlad Yasevicha5a35e72007-03-23 11:34:08 -07001752 NULL, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001753 if (!ev)
1754 goto nomem_ev;
1755
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001756 /* Update the content of current association. */
1757 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1758 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001759 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
1760 return SCTP_DISPOSITION_CONSUME;
1761
1762nomem_ev:
1763 sctp_chunk_free(repl);
1764nomem:
1765 return SCTP_DISPOSITION_NOMEM;
1766}
1767
1768/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B')
1769 *
1770 * Section 5.2.4
1771 * B) In this case, both sides may be attempting to start an association
1772 * at about the same time but the peer endpoint started its INIT
1773 * after responding to the local endpoint's INIT
1774 */
1775/* This case represents an initialization collision. */
1776static sctp_disposition_t sctp_sf_do_dupcook_b(const struct sctp_endpoint *ep,
1777 const struct sctp_association *asoc,
1778 struct sctp_chunk *chunk,
1779 sctp_cmd_seq_t *commands,
1780 struct sctp_association *new_asoc)
1781{
1782 sctp_init_chunk_t *peer_init;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001783 struct sctp_chunk *repl;
1784
1785 /* new_asoc is a brand-new association, so these are not yet
1786 * side effects--it is safe to run them here.
1787 */
1788 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1789 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
1790 sctp_source(chunk), peer_init,
1791 GFP_ATOMIC))
1792 goto nomem;
1793
1794 /* Update the content of current association. */
1795 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1796 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1797 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1798 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
1799 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
1800
1801 repl = sctp_make_cookie_ack(new_asoc, chunk);
1802 if (!repl)
1803 goto nomem;
1804
1805 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1806 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
1807
1808 /* RFC 2960 5.1 Normal Establishment of an Association
1809 *
1810 * D) IMPLEMENTATION NOTE: An implementation may choose to
1811 * send the Communication Up notification to the SCTP user
1812 * upon reception of a valid COOKIE ECHO chunk.
Vlad Yasevich07d93962007-05-04 13:55:27 -07001813 *
1814 * Sadly, this needs to be implemented as a side-effect, because
1815 * we are not guaranteed to have set the association id of the real
1816 * association and so these notifications need to be delayed until
1817 * the association id is allocated.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001818 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001819
Vlad Yasevich07d93962007-05-04 13:55:27 -07001820 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_CHANGE, SCTP_U8(SCTP_COMM_UP));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001821
1822 /* Sockets API Draft Section 5.3.1.6
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -08001823 * When a peer sends a Adaptation Layer Indication parameter , SCTP
Linus Torvalds1da177e2005-04-16 15:20:36 -07001824 * delivers this notification to inform the application that of the
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -08001825 * peers requested adaptation layer.
Vlad Yasevich07d93962007-05-04 13:55:27 -07001826 *
1827 * This also needs to be done as a side effect for the same reason as
1828 * above.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001829 */
Vlad Yasevich07d93962007-05-04 13:55:27 -07001830 if (asoc->peer.adaptation_ind)
1831 sctp_add_cmd_sf(commands, SCTP_CMD_ADAPTATION_IND, SCTP_NULL());
Linus Torvalds1da177e2005-04-16 15:20:36 -07001832
1833 return SCTP_DISPOSITION_CONSUME;
1834
Linus Torvalds1da177e2005-04-16 15:20:36 -07001835nomem:
1836 return SCTP_DISPOSITION_NOMEM;
1837}
1838
1839/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C')
1840 *
1841 * Section 5.2.4
1842 * C) In this case, the local endpoint's cookie has arrived late.
1843 * Before it arrived, the local endpoint sent an INIT and received an
1844 * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag
1845 * but a new tag of its own.
1846 */
1847/* This case represents an initialization collision. */
1848static sctp_disposition_t sctp_sf_do_dupcook_c(const struct sctp_endpoint *ep,
1849 const struct sctp_association *asoc,
1850 struct sctp_chunk *chunk,
1851 sctp_cmd_seq_t *commands,
1852 struct sctp_association *new_asoc)
1853{
1854 /* The cookie should be silently discarded.
1855 * The endpoint SHOULD NOT change states and should leave
1856 * any timers running.
1857 */
1858 return SCTP_DISPOSITION_DISCARD;
1859}
1860
1861/* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D')
1862 *
1863 * Section 5.2.4
1864 *
1865 * D) When both local and remote tags match the endpoint should always
1866 * enter the ESTABLISHED state, if it has not already done so.
1867 */
1868/* This case represents an initialization collision. */
1869static sctp_disposition_t sctp_sf_do_dupcook_d(const struct sctp_endpoint *ep,
1870 const struct sctp_association *asoc,
1871 struct sctp_chunk *chunk,
1872 sctp_cmd_seq_t *commands,
1873 struct sctp_association *new_asoc)
1874{
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001875 struct sctp_ulpevent *ev = NULL, *ai_ev = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001876 struct sctp_chunk *repl;
1877
1878 /* Clarification from Implementor's Guide:
1879 * D) When both local and remote tags match the endpoint should
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001880 * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state.
1881 * It should stop any cookie timer that may be running and send
1882 * a COOKIE ACK.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001883 */
1884
1885 /* Don't accidentally move back into established state. */
1886 if (asoc->state < SCTP_STATE_ESTABLISHED) {
1887 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1888 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1889 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1890 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1891 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
1892 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START,
1893 SCTP_NULL());
1894
1895 /* RFC 2960 5.1 Normal Establishment of an Association
1896 *
1897 * D) IMPLEMENTATION NOTE: An implementation may choose
1898 * to send the Communication Up notification to the
1899 * SCTP user upon reception of a valid COOKIE
1900 * ECHO chunk.
1901 */
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001902 ev = sctp_ulpevent_make_assoc_change(asoc, 0,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001903 SCTP_COMM_UP, 0,
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001904 asoc->c.sinit_num_ostreams,
1905 asoc->c.sinit_max_instreams,
YOSHIFUJI Hideaki9cbcbf42007-07-19 10:44:50 +09001906 NULL, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001907 if (!ev)
1908 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001909
1910 /* Sockets API Draft Section 5.3.1.6
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -08001911 * When a peer sends a Adaptation Layer Indication parameter,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001912 * SCTP delivers this notification to inform the application
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -08001913 * that of the peers requested adaptation layer.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001914 */
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -08001915 if (asoc->peer.adaptation_ind) {
1916 ai_ev = sctp_ulpevent_make_adaptation_indication(asoc,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001917 GFP_ATOMIC);
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001918 if (!ai_ev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001919 goto nomem;
1920
Linus Torvalds1da177e2005-04-16 15:20:36 -07001921 }
1922 }
1923 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
1924
1925 repl = sctp_make_cookie_ack(new_asoc, chunk);
1926 if (!repl)
1927 goto nomem;
1928
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001929 if (ev)
1930 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1931 SCTP_ULPEVENT(ev));
1932 if (ai_ev)
1933 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1934 SCTP_ULPEVENT(ai_ev));
1935
Linus Torvalds1da177e2005-04-16 15:20:36 -07001936 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1937 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
1938
1939 return SCTP_DISPOSITION_CONSUME;
1940
1941nomem:
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001942 if (ai_ev)
1943 sctp_ulpevent_free(ai_ev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001944 if (ev)
1945 sctp_ulpevent_free(ev);
1946 return SCTP_DISPOSITION_NOMEM;
1947}
1948
1949/*
1950 * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying
1951 * chunk was retransmitted and then delayed in the network.
1952 *
1953 * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists
1954 *
1955 * Verification Tag: None. Do cookie validation.
1956 *
1957 * Inputs
1958 * (endpoint, asoc, chunk)
1959 *
1960 * Outputs
1961 * (asoc, reply_msg, msg_up, timers, counters)
1962 *
1963 * The return value is the disposition of the chunk.
1964 */
1965sctp_disposition_t sctp_sf_do_5_2_4_dupcook(const struct sctp_endpoint *ep,
1966 const struct sctp_association *asoc,
1967 const sctp_subtype_t type,
1968 void *arg,
1969 sctp_cmd_seq_t *commands)
1970{
1971 sctp_disposition_t retval;
1972 struct sctp_chunk *chunk = arg;
1973 struct sctp_association *new_asoc;
1974 int error = 0;
1975 char action;
1976 struct sctp_chunk *err_chk_p;
1977
1978 /* Make sure that the chunk has a valid length from the protocol
1979 * perspective. In this case check to make sure we have at least
1980 * enough for the chunk header. Cookie length verification is
1981 * done later.
1982 */
1983 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
1984 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1985 commands);
1986
1987 /* "Decode" the chunk. We have no optional parameters so we
1988 * are in good shape.
1989 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001990 chunk->subh.cookie_hdr = (struct sctp_signed_cookie *)chunk->skb->data;
Sridhar Samudrala62b08082006-05-05 17:04:43 -07001991 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
1992 sizeof(sctp_chunkhdr_t)))
1993 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001994
1995 /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
1996 * of a duplicate COOKIE ECHO match the Verification Tags of the
1997 * current association, consider the State Cookie valid even if
1998 * the lifespan is exceeded.
1999 */
2000 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
2001 &err_chk_p);
2002
2003 /* FIXME:
2004 * If the re-build failed, what is the proper error path
2005 * from here?
2006 *
2007 * [We should abort the association. --piggy]
2008 */
2009 if (!new_asoc) {
2010 /* FIXME: Several errors are possible. A bad cookie should
2011 * be silently discarded, but think about logging it too.
2012 */
2013 switch (error) {
2014 case -SCTP_IERROR_NOMEM:
2015 goto nomem;
2016
2017 case -SCTP_IERROR_STALE_COOKIE:
2018 sctp_send_stale_cookie_err(ep, asoc, chunk, commands,
2019 err_chk_p);
2020 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2021 case -SCTP_IERROR_BAD_SIG:
2022 default:
2023 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07002024 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002025 }
2026
2027 /* Compare the tie_tag in cookie with the verification tag of
2028 * current association.
2029 */
2030 action = sctp_tietags_compare(new_asoc, asoc);
2031
2032 switch (action) {
2033 case 'A': /* Association restart. */
2034 retval = sctp_sf_do_dupcook_a(ep, asoc, chunk, commands,
2035 new_asoc);
2036 break;
2037
2038 case 'B': /* Collision case B. */
2039 retval = sctp_sf_do_dupcook_b(ep, asoc, chunk, commands,
2040 new_asoc);
2041 break;
2042
2043 case 'C': /* Collision case C. */
2044 retval = sctp_sf_do_dupcook_c(ep, asoc, chunk, commands,
2045 new_asoc);
2046 break;
2047
2048 case 'D': /* Collision case D. */
2049 retval = sctp_sf_do_dupcook_d(ep, asoc, chunk, commands,
2050 new_asoc);
2051 break;
2052
2053 default: /* Discard packet for all others. */
2054 retval = sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2055 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07002056 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002057
2058 /* Delete the tempory new association. */
2059 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
2060 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
2061
2062 return retval;
2063
2064nomem:
2065 return SCTP_DISPOSITION_NOMEM;
2066}
2067
2068/*
2069 * Process an ABORT. (SHUTDOWN-PENDING state)
2070 *
2071 * See sctp_sf_do_9_1_abort().
2072 */
2073sctp_disposition_t sctp_sf_shutdown_pending_abort(
2074 const struct sctp_endpoint *ep,
2075 const struct sctp_association *asoc,
2076 const sctp_subtype_t type,
2077 void *arg,
2078 sctp_cmd_seq_t *commands)
2079{
2080 struct sctp_chunk *chunk = arg;
2081
2082 if (!sctp_vtag_verify_either(chunk, asoc))
2083 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2084
2085 /* Make sure that the ABORT chunk has a valid length.
2086 * Since this is an ABORT chunk, we have to discard it
2087 * because of the following text:
2088 * RFC 2960, Section 3.3.7
2089 * If an endpoint receives an ABORT with a format error or for an
2090 * association that doesn't exist, it MUST silently discard it.
2091 * Becasue the length is "invalid", we can't really discard just
2092 * as we do not know its true length. So, to be safe, discard the
2093 * packet.
2094 */
2095 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2096 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2097
2098 /* Stop the T5-shutdown guard timer. */
2099 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2100 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
2101
2102 return sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
2103}
2104
2105/*
2106 * Process an ABORT. (SHUTDOWN-SENT state)
2107 *
2108 * See sctp_sf_do_9_1_abort().
2109 */
2110sctp_disposition_t sctp_sf_shutdown_sent_abort(const struct sctp_endpoint *ep,
2111 const struct sctp_association *asoc,
2112 const sctp_subtype_t type,
2113 void *arg,
2114 sctp_cmd_seq_t *commands)
2115{
2116 struct sctp_chunk *chunk = arg;
2117
2118 if (!sctp_vtag_verify_either(chunk, asoc))
2119 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2120
2121 /* Make sure that the ABORT chunk has a valid length.
2122 * Since this is an ABORT chunk, we have to discard it
2123 * because of the following text:
2124 * RFC 2960, Section 3.3.7
2125 * If an endpoint receives an ABORT with a format error or for an
2126 * association that doesn't exist, it MUST silently discard it.
2127 * Becasue the length is "invalid", we can't really discard just
2128 * as we do not know its true length. So, to be safe, discard the
2129 * packet.
2130 */
2131 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2132 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2133
2134 /* Stop the T2-shutdown timer. */
2135 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2136 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2137
2138 /* Stop the T5-shutdown guard timer. */
2139 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2140 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
2141
2142 return sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
2143}
2144
2145/*
2146 * Process an ABORT. (SHUTDOWN-ACK-SENT state)
2147 *
2148 * See sctp_sf_do_9_1_abort().
2149 */
2150sctp_disposition_t sctp_sf_shutdown_ack_sent_abort(
2151 const struct sctp_endpoint *ep,
2152 const struct sctp_association *asoc,
2153 const sctp_subtype_t type,
2154 void *arg,
2155 sctp_cmd_seq_t *commands)
2156{
2157 /* The same T2 timer, so we should be able to use
2158 * common function with the SHUTDOWN-SENT state.
2159 */
2160 return sctp_sf_shutdown_sent_abort(ep, asoc, type, arg, commands);
2161}
2162
2163/*
2164 * Handle an Error received in COOKIE_ECHOED state.
2165 *
2166 * Only handle the error type of stale COOKIE Error, the other errors will
2167 * be ignored.
2168 *
2169 * Inputs
2170 * (endpoint, asoc, chunk)
2171 *
2172 * Outputs
2173 * (asoc, reply_msg, msg_up, timers, counters)
2174 *
2175 * The return value is the disposition of the chunk.
2176 */
2177sctp_disposition_t sctp_sf_cookie_echoed_err(const struct sctp_endpoint *ep,
2178 const struct sctp_association *asoc,
2179 const sctp_subtype_t type,
2180 void *arg,
2181 sctp_cmd_seq_t *commands)
2182{
2183 struct sctp_chunk *chunk = arg;
2184 sctp_errhdr_t *err;
2185
2186 if (!sctp_vtag_verify(chunk, asoc))
2187 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2188
2189 /* Make sure that the ERROR chunk has a valid length.
2190 * The parameter walking depends on this as well.
2191 */
2192 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
2193 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2194 commands);
2195
2196 /* Process the error here */
2197 /* FUTURE FIXME: When PR-SCTP related and other optional
2198 * parms are emitted, this will have to change to handle multiple
2199 * errors.
2200 */
2201 sctp_walk_errors(err, chunk->chunk_hdr) {
2202 if (SCTP_ERROR_STALE_COOKIE == err->cause)
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002203 return sctp_sf_do_5_2_6_stale(ep, asoc, type,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002204 arg, commands);
2205 }
2206
2207 /* It is possible to have malformed error causes, and that
2208 * will cause us to end the walk early. However, since
2209 * we are discarding the packet, there should be no adverse
2210 * affects.
2211 */
2212 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2213}
2214
2215/*
2216 * Handle a Stale COOKIE Error
2217 *
2218 * Section: 5.2.6 Handle Stale COOKIE Error
2219 * If the association is in the COOKIE-ECHOED state, the endpoint may elect
2220 * one of the following three alternatives.
2221 * ...
2222 * 3) Send a new INIT chunk to the endpoint, adding a Cookie
2223 * Preservative parameter requesting an extension to the lifetime of
2224 * the State Cookie. When calculating the time extension, an
2225 * implementation SHOULD use the RTT information measured based on the
2226 * previous COOKIE ECHO / ERROR exchange, and should add no more
2227 * than 1 second beyond the measured RTT, due to long State Cookie
2228 * lifetimes making the endpoint more subject to a replay attack.
2229 *
2230 * Verification Tag: Not explicit, but safe to ignore.
2231 *
2232 * Inputs
2233 * (endpoint, asoc, chunk)
2234 *
2235 * Outputs
2236 * (asoc, reply_msg, msg_up, timers, counters)
2237 *
2238 * The return value is the disposition of the chunk.
2239 */
2240static sctp_disposition_t sctp_sf_do_5_2_6_stale(const struct sctp_endpoint *ep,
2241 const struct sctp_association *asoc,
2242 const sctp_subtype_t type,
2243 void *arg,
2244 sctp_cmd_seq_t *commands)
2245{
2246 struct sctp_chunk *chunk = arg;
2247 time_t stale;
2248 sctp_cookie_preserve_param_t bht;
2249 sctp_errhdr_t *err;
2250 struct sctp_chunk *reply;
2251 struct sctp_bind_addr *bp;
Frank Filz3f7a87d2005-06-20 13:14:57 -07002252 int attempts = asoc->init_err_counter + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002253
Vlad Yasevich81845c22006-01-30 15:59:54 -08002254 if (attempts > asoc->max_init_attempts) {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002255 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
2256 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002257 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08002258 SCTP_PERR(SCTP_ERROR_STALE_COOKIE));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002259 return SCTP_DISPOSITION_DELETE_TCB;
2260 }
2261
2262 err = (sctp_errhdr_t *)(chunk->skb->data);
2263
2264 /* When calculating the time extension, an implementation
2265 * SHOULD use the RTT information measured based on the
2266 * previous COOKIE ECHO / ERROR exchange, and should add no
2267 * more than 1 second beyond the measured RTT, due to long
2268 * State Cookie lifetimes making the endpoint more subject to
2269 * a replay attack.
2270 * Measure of Staleness's unit is usec. (1/1000000 sec)
2271 * Suggested Cookie Life-span Increment's unit is msec.
2272 * (1/1000 sec)
2273 * In general, if you use the suggested cookie life, the value
2274 * found in the field of measure of staleness should be doubled
2275 * to give ample time to retransmit the new cookie and thus
2276 * yield a higher probability of success on the reattempt.
2277 */
Al Viro34bcca22006-11-20 17:27:15 -08002278 stale = ntohl(*(__be32 *)((u8 *)err + sizeof(sctp_errhdr_t)));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002279 stale = (stale * 2) / 1000;
2280
2281 bht.param_hdr.type = SCTP_PARAM_COOKIE_PRESERVATIVE;
2282 bht.param_hdr.length = htons(sizeof(bht));
2283 bht.lifespan_increment = htonl(stale);
2284
2285 /* Build that new INIT chunk. */
2286 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
2287 reply = sctp_make_init(asoc, bp, GFP_ATOMIC, sizeof(bht));
2288 if (!reply)
2289 goto nomem;
2290
2291 sctp_addto_chunk(reply, sizeof(bht), &bht);
2292
2293 /* Clear peer's init_tag cached in assoc as we are sending a new INIT */
2294 sctp_add_cmd_sf(commands, SCTP_CMD_CLEAR_INIT_TAG, SCTP_NULL());
2295
2296 /* Stop pending T3-rtx and heartbeat timers */
2297 sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
2298 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
2299
2300 /* Delete non-primary peer ip addresses since we are transitioning
2301 * back to the COOKIE-WAIT state
2302 */
2303 sctp_add_cmd_sf(commands, SCTP_CMD_DEL_NON_PRIMARY, SCTP_NULL());
2304
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002305 /* If we've sent any data bundled with COOKIE-ECHO we will need to
2306 * resend
Linus Torvalds1da177e2005-04-16 15:20:36 -07002307 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002308 sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002309 SCTP_TRANSPORT(asoc->peer.primary_path));
2310
2311 /* Cast away the const modifier, as we want to just
2312 * rerun it through as a sideffect.
2313 */
Frank Filz3f7a87d2005-06-20 13:14:57 -07002314 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_INC, SCTP_NULL());
Linus Torvalds1da177e2005-04-16 15:20:36 -07002315
2316 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2317 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
2318 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2319 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
2320 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
2321 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
2322
2323 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2324
2325 return SCTP_DISPOSITION_CONSUME;
2326
2327nomem:
2328 return SCTP_DISPOSITION_NOMEM;
2329}
2330
2331/*
2332 * Process an ABORT.
2333 *
2334 * Section: 9.1
2335 * After checking the Verification Tag, the receiving endpoint shall
2336 * remove the association from its record, and shall report the
2337 * termination to its upper layer.
2338 *
2339 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
2340 * B) Rules for packet carrying ABORT:
2341 *
2342 * - The endpoint shall always fill in the Verification Tag field of the
2343 * outbound packet with the destination endpoint's tag value if it
2344 * is known.
2345 *
2346 * - If the ABORT is sent in response to an OOTB packet, the endpoint
2347 * MUST follow the procedure described in Section 8.4.
2348 *
2349 * - The receiver MUST accept the packet if the Verification Tag
2350 * matches either its own tag, OR the tag of its peer. Otherwise, the
2351 * receiver MUST silently discard the packet and take no further
2352 * action.
2353 *
2354 * Inputs
2355 * (endpoint, asoc, chunk)
2356 *
2357 * Outputs
2358 * (asoc, reply_msg, msg_up, timers, counters)
2359 *
2360 * The return value is the disposition of the chunk.
2361 */
2362sctp_disposition_t sctp_sf_do_9_1_abort(const struct sctp_endpoint *ep,
2363 const struct sctp_association *asoc,
2364 const sctp_subtype_t type,
2365 void *arg,
2366 sctp_cmd_seq_t *commands)
2367{
2368 struct sctp_chunk *chunk = arg;
2369 unsigned len;
Al Viro5be291f2006-11-20 17:01:06 -08002370 __be16 error = SCTP_ERROR_NO_ERROR;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002371
2372 if (!sctp_vtag_verify_either(chunk, asoc))
2373 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2374
2375 /* Make sure that the ABORT chunk has a valid length.
2376 * Since this is an ABORT chunk, we have to discard it
2377 * because of the following text:
2378 * RFC 2960, Section 3.3.7
2379 * If an endpoint receives an ABORT with a format error or for an
2380 * association that doesn't exist, it MUST silently discard it.
2381 * Becasue the length is "invalid", we can't really discard just
2382 * as we do not know its true length. So, to be safe, discard the
2383 * packet.
2384 */
2385 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2386 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2387
2388 /* See if we have an error cause code in the chunk. */
2389 len = ntohs(chunk->chunk_hdr->length);
2390 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
2391 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2392
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002393 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNRESET));
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002394 /* ASSOC_FAILED will DELETE_TCB. */
Al Viro5be291f2006-11-20 17:01:06 -08002395 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, SCTP_PERR(error));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002396 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
2397 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
2398
2399 return SCTP_DISPOSITION_ABORT;
2400}
2401
2402/*
2403 * Process an ABORT. (COOKIE-WAIT state)
2404 *
2405 * See sctp_sf_do_9_1_abort() above.
2406 */
2407sctp_disposition_t sctp_sf_cookie_wait_abort(const struct sctp_endpoint *ep,
2408 const struct sctp_association *asoc,
2409 const sctp_subtype_t type,
2410 void *arg,
2411 sctp_cmd_seq_t *commands)
2412{
2413 struct sctp_chunk *chunk = arg;
2414 unsigned len;
Al Virof94c0192006-11-20 17:00:25 -08002415 __be16 error = SCTP_ERROR_NO_ERROR;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002416
2417 if (!sctp_vtag_verify_either(chunk, asoc))
2418 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2419
2420 /* Make sure that the ABORT chunk has a valid length.
2421 * Since this is an ABORT chunk, we have to discard it
2422 * because of the following text:
2423 * RFC 2960, Section 3.3.7
2424 * If an endpoint receives an ABORT with a format error or for an
2425 * association that doesn't exist, it MUST silently discard it.
2426 * Becasue the length is "invalid", we can't really discard just
2427 * as we do not know its true length. So, to be safe, discard the
2428 * packet.
2429 */
2430 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2431 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2432
2433 /* See if we have an error cause code in the chunk. */
2434 len = ntohs(chunk->chunk_hdr->length);
2435 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
2436 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2437
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002438 return sctp_stop_t1_and_abort(commands, error, ECONNREFUSED, asoc,
2439 chunk->transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002440}
2441
2442/*
2443 * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state)
2444 */
2445sctp_disposition_t sctp_sf_cookie_wait_icmp_abort(const struct sctp_endpoint *ep,
2446 const struct sctp_association *asoc,
2447 const sctp_subtype_t type,
2448 void *arg,
2449 sctp_cmd_seq_t *commands)
2450{
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002451 return sctp_stop_t1_and_abort(commands, SCTP_ERROR_NO_ERROR,
2452 ENOPROTOOPT, asoc,
Frank Filz3f7a87d2005-06-20 13:14:57 -07002453 (struct sctp_transport *)arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002454}
2455
2456/*
2457 * Process an ABORT. (COOKIE-ECHOED state)
2458 */
2459sctp_disposition_t sctp_sf_cookie_echoed_abort(const struct sctp_endpoint *ep,
2460 const struct sctp_association *asoc,
2461 const sctp_subtype_t type,
2462 void *arg,
2463 sctp_cmd_seq_t *commands)
2464{
2465 /* There is a single T1 timer, so we should be able to use
2466 * common function with the COOKIE-WAIT state.
2467 */
2468 return sctp_sf_cookie_wait_abort(ep, asoc, type, arg, commands);
2469}
2470
2471/*
2472 * Stop T1 timer and abort association with "INIT failed".
2473 *
2474 * This is common code called by several sctp_sf_*_abort() functions above.
2475 */
Adrian Bunk52c1da32005-06-23 22:05:33 -07002476static sctp_disposition_t sctp_stop_t1_and_abort(sctp_cmd_seq_t *commands,
Al Virof94c0192006-11-20 17:00:25 -08002477 __be16 error, int sk_err,
Frank Filz3f7a87d2005-06-20 13:14:57 -07002478 const struct sctp_association *asoc,
2479 struct sctp_transport *transport)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002480{
Frank Filz3f7a87d2005-06-20 13:14:57 -07002481 SCTP_DEBUG_PRINTK("ABORT received (INIT).\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07002482 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2483 SCTP_STATE(SCTP_STATE_CLOSED));
2484 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
2485 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2486 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002487 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(sk_err));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002488 /* CMD_INIT_FAILED will DELETE_TCB. */
2489 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08002490 SCTP_PERR(error));
Frank Filz3f7a87d2005-06-20 13:14:57 -07002491 return SCTP_DISPOSITION_ABORT;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002492}
2493
2494/*
2495 * sctp_sf_do_9_2_shut
2496 *
2497 * Section: 9.2
2498 * Upon the reception of the SHUTDOWN, the peer endpoint shall
2499 * - enter the SHUTDOWN-RECEIVED state,
2500 *
2501 * - stop accepting new data from its SCTP user
2502 *
2503 * - verify, by checking the Cumulative TSN Ack field of the chunk,
2504 * that all its outstanding DATA chunks have been received by the
2505 * SHUTDOWN sender.
2506 *
2507 * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT
2508 * send a SHUTDOWN in response to a ULP request. And should discard
2509 * subsequent SHUTDOWN chunks.
2510 *
2511 * If there are still outstanding DATA chunks left, the SHUTDOWN
2512 * receiver shall continue to follow normal data transmission
2513 * procedures defined in Section 6 until all outstanding DATA chunks
2514 * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept
2515 * new data from its SCTP user.
2516 *
2517 * Verification Tag: 8.5 Verification Tag [Normal verification]
2518 *
2519 * Inputs
2520 * (endpoint, asoc, chunk)
2521 *
2522 * Outputs
2523 * (asoc, reply_msg, msg_up, timers, counters)
2524 *
2525 * The return value is the disposition of the chunk.
2526 */
2527sctp_disposition_t sctp_sf_do_9_2_shutdown(const struct sctp_endpoint *ep,
2528 const struct sctp_association *asoc,
2529 const sctp_subtype_t type,
2530 void *arg,
2531 sctp_cmd_seq_t *commands)
2532{
2533 struct sctp_chunk *chunk = arg;
2534 sctp_shutdownhdr_t *sdh;
2535 sctp_disposition_t disposition;
2536 struct sctp_ulpevent *ev;
2537
2538 if (!sctp_vtag_verify(chunk, asoc))
2539 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2540
2541 /* Make sure that the SHUTDOWN chunk has a valid length. */
2542 if (!sctp_chunk_length_valid(chunk,
2543 sizeof(struct sctp_shutdown_chunk_t)))
2544 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2545 commands);
2546
2547 /* Convert the elaborate header. */
2548 sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
2549 skb_pull(chunk->skb, sizeof(sctp_shutdownhdr_t));
2550 chunk->subh.shutdown_hdr = sdh;
2551
Sridhar Samudralaeb0e0072005-09-22 23:48:38 -07002552 /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT
2553 * When a peer sends a SHUTDOWN, SCTP delivers this notification to
2554 * inform the application that it should cease sending data.
2555 */
2556 ev = sctp_ulpevent_make_shutdown_event(asoc, 0, GFP_ATOMIC);
2557 if (!ev) {
2558 disposition = SCTP_DISPOSITION_NOMEM;
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002559 goto out;
Sridhar Samudralaeb0e0072005-09-22 23:48:38 -07002560 }
2561 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
2562
Linus Torvalds1da177e2005-04-16 15:20:36 -07002563 /* Upon the reception of the SHUTDOWN, the peer endpoint shall
2564 * - enter the SHUTDOWN-RECEIVED state,
2565 * - stop accepting new data from its SCTP user
2566 *
2567 * [This is implicit in the new state.]
2568 */
2569 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2570 SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED));
2571 disposition = SCTP_DISPOSITION_CONSUME;
2572
2573 if (sctp_outq_is_empty(&asoc->outqueue)) {
2574 disposition = sctp_sf_do_9_2_shutdown_ack(ep, asoc, type,
2575 arg, commands);
2576 }
2577
2578 if (SCTP_DISPOSITION_NOMEM == disposition)
2579 goto out;
2580
2581 /* - verify, by checking the Cumulative TSN Ack field of the
2582 * chunk, that all its outstanding DATA chunks have been
2583 * received by the SHUTDOWN sender.
2584 */
2585 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
Al Viro2178eda2006-11-20 17:26:53 -08002586 SCTP_BE32(chunk->subh.shutdown_hdr->cum_tsn_ack));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002587
Linus Torvalds1da177e2005-04-16 15:20:36 -07002588out:
2589 return disposition;
2590}
2591
2592/* RFC 2960 9.2
2593 * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk
2594 * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination
2595 * transport addresses (either in the IP addresses or in the INIT chunk)
2596 * that belong to this association, it should discard the INIT chunk and
2597 * retransmit the SHUTDOWN ACK chunk.
2598 */
2599sctp_disposition_t sctp_sf_do_9_2_reshutack(const struct sctp_endpoint *ep,
2600 const struct sctp_association *asoc,
2601 const sctp_subtype_t type,
2602 void *arg,
2603 sctp_cmd_seq_t *commands)
2604{
2605 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
2606 struct sctp_chunk *reply;
2607
Vlad Yasevichece25df2007-09-07 16:30:54 -04002608 /* Make sure that the chunk has a valid length */
2609 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
2610 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2611 commands);
2612
Linus Torvalds1da177e2005-04-16 15:20:36 -07002613 /* Since we are not going to really process this INIT, there
2614 * is no point in verifying chunk boundries. Just generate
2615 * the SHUTDOWN ACK.
2616 */
2617 reply = sctp_make_shutdown_ack(asoc, chunk);
2618 if (NULL == reply)
2619 goto nomem;
2620
2621 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
2622 * the T2-SHUTDOWN timer.
2623 */
2624 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
2625
2626 /* and restart the T2-shutdown timer. */
2627 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2628 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2629
2630 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2631
2632 return SCTP_DISPOSITION_CONSUME;
2633nomem:
2634 return SCTP_DISPOSITION_NOMEM;
2635}
2636
2637/*
2638 * sctp_sf_do_ecn_cwr
2639 *
2640 * Section: Appendix A: Explicit Congestion Notification
2641 *
2642 * CWR:
2643 *
2644 * RFC 2481 details a specific bit for a sender to send in the header of
2645 * its next outbound TCP segment to indicate to its peer that it has
2646 * reduced its congestion window. This is termed the CWR bit. For
2647 * SCTP the same indication is made by including the CWR chunk.
2648 * This chunk contains one data element, i.e. the TSN number that
2649 * was sent in the ECNE chunk. This element represents the lowest
2650 * TSN number in the datagram that was originally marked with the
2651 * CE bit.
2652 *
2653 * Verification Tag: 8.5 Verification Tag [Normal verification]
2654 * Inputs
2655 * (endpoint, asoc, chunk)
2656 *
2657 * Outputs
2658 * (asoc, reply_msg, msg_up, timers, counters)
2659 *
2660 * The return value is the disposition of the chunk.
2661 */
2662sctp_disposition_t sctp_sf_do_ecn_cwr(const struct sctp_endpoint *ep,
2663 const struct sctp_association *asoc,
2664 const sctp_subtype_t type,
2665 void *arg,
2666 sctp_cmd_seq_t *commands)
2667{
2668 sctp_cwrhdr_t *cwr;
2669 struct sctp_chunk *chunk = arg;
Al Viro34bcca22006-11-20 17:27:15 -08002670 u32 lowest_tsn;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002671
2672 if (!sctp_vtag_verify(chunk, asoc))
2673 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2674
2675 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2676 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2677 commands);
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002678
Linus Torvalds1da177e2005-04-16 15:20:36 -07002679 cwr = (sctp_cwrhdr_t *) chunk->skb->data;
2680 skb_pull(chunk->skb, sizeof(sctp_cwrhdr_t));
2681
Al Viro34bcca22006-11-20 17:27:15 -08002682 lowest_tsn = ntohl(cwr->lowest_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002683
2684 /* Does this CWR ack the last sent congestion notification? */
Al Viro34bcca22006-11-20 17:27:15 -08002685 if (TSN_lte(asoc->last_ecne_tsn, lowest_tsn)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002686 /* Stop sending ECNE. */
2687 sctp_add_cmd_sf(commands,
2688 SCTP_CMD_ECN_CWR,
Al Viro34bcca22006-11-20 17:27:15 -08002689 SCTP_U32(lowest_tsn));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002690 }
2691 return SCTP_DISPOSITION_CONSUME;
2692}
2693
2694/*
2695 * sctp_sf_do_ecne
2696 *
2697 * Section: Appendix A: Explicit Congestion Notification
2698 *
2699 * ECN-Echo
2700 *
2701 * RFC 2481 details a specific bit for a receiver to send back in its
2702 * TCP acknowledgements to notify the sender of the Congestion
2703 * Experienced (CE) bit having arrived from the network. For SCTP this
2704 * same indication is made by including the ECNE chunk. This chunk
2705 * contains one data element, i.e. the lowest TSN associated with the IP
2706 * datagram marked with the CE bit.....
2707 *
2708 * Verification Tag: 8.5 Verification Tag [Normal verification]
2709 * Inputs
2710 * (endpoint, asoc, chunk)
2711 *
2712 * Outputs
2713 * (asoc, reply_msg, msg_up, timers, counters)
2714 *
2715 * The return value is the disposition of the chunk.
2716 */
2717sctp_disposition_t sctp_sf_do_ecne(const struct sctp_endpoint *ep,
2718 const struct sctp_association *asoc,
2719 const sctp_subtype_t type,
2720 void *arg,
2721 sctp_cmd_seq_t *commands)
2722{
2723 sctp_ecnehdr_t *ecne;
2724 struct sctp_chunk *chunk = arg;
2725
2726 if (!sctp_vtag_verify(chunk, asoc))
2727 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2728
2729 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2730 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2731 commands);
2732
2733 ecne = (sctp_ecnehdr_t *) chunk->skb->data;
2734 skb_pull(chunk->skb, sizeof(sctp_ecnehdr_t));
2735
2736 /* If this is a newer ECNE than the last CWR packet we sent out */
2737 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_ECNE,
2738 SCTP_U32(ntohl(ecne->lowest_tsn)));
2739
2740 return SCTP_DISPOSITION_CONSUME;
2741}
2742
2743/*
2744 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
2745 *
2746 * The SCTP endpoint MUST always acknowledge the reception of each valid
2747 * DATA chunk.
2748 *
2749 * The guidelines on delayed acknowledgement algorithm specified in
2750 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
2751 * acknowledgement SHOULD be generated for at least every second packet
2752 * (not every second DATA chunk) received, and SHOULD be generated within
2753 * 200 ms of the arrival of any unacknowledged DATA chunk. In some
2754 * situations it may be beneficial for an SCTP transmitter to be more
2755 * conservative than the algorithms detailed in this document allow.
2756 * However, an SCTP transmitter MUST NOT be more aggressive than the
2757 * following algorithms allow.
2758 *
2759 * A SCTP receiver MUST NOT generate more than one SACK for every
2760 * incoming packet, other than to update the offered window as the
2761 * receiving application consumes new data.
2762 *
2763 * Verification Tag: 8.5 Verification Tag [Normal verification]
2764 *
2765 * Inputs
2766 * (endpoint, asoc, chunk)
2767 *
2768 * Outputs
2769 * (asoc, reply_msg, msg_up, timers, counters)
2770 *
2771 * The return value is the disposition of the chunk.
2772 */
2773sctp_disposition_t sctp_sf_eat_data_6_2(const struct sctp_endpoint *ep,
2774 const struct sctp_association *asoc,
2775 const sctp_subtype_t type,
2776 void *arg,
2777 sctp_cmd_seq_t *commands)
2778{
2779 struct sctp_chunk *chunk = arg;
2780 int error;
2781
2782 if (!sctp_vtag_verify(chunk, asoc)) {
2783 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
2784 SCTP_NULL());
2785 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002786 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002787
2788 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
2789 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2790 commands);
2791
2792 error = sctp_eat_data(asoc, chunk, commands );
2793 switch (error) {
2794 case SCTP_IERROR_NO_ERROR:
2795 break;
2796 case SCTP_IERROR_HIGH_TSN:
2797 case SCTP_IERROR_BAD_STREAM:
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07002798 SCTP_INC_STATS(SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002799 goto discard_noforce;
2800 case SCTP_IERROR_DUP_TSN:
2801 case SCTP_IERROR_IGNORE_TSN:
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07002802 SCTP_INC_STATS(SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002803 goto discard_force;
2804 case SCTP_IERROR_NO_DATA:
2805 goto consume;
2806 default:
2807 BUG();
2808 }
2809
2810 if (asoc->autoclose) {
2811 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2812 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
2813 }
2814
2815 /* If this is the last chunk in a packet, we need to count it
2816 * toward sack generation. Note that we need to SACK every
2817 * OTHER packet containing data chunks, EVEN IF WE DISCARD
2818 * THEM. We elect to NOT generate SACK's if the chunk fails
2819 * the verification tag test.
2820 *
2821 * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2822 *
2823 * The SCTP endpoint MUST always acknowledge the reception of
2824 * each valid DATA chunk.
2825 *
2826 * The guidelines on delayed acknowledgement algorithm
2827 * specified in Section 4.2 of [RFC2581] SHOULD be followed.
2828 * Specifically, an acknowledgement SHOULD be generated for at
2829 * least every second packet (not every second DATA chunk)
2830 * received, and SHOULD be generated within 200 ms of the
2831 * arrival of any unacknowledged DATA chunk. In some
2832 * situations it may be beneficial for an SCTP transmitter to
2833 * be more conservative than the algorithms detailed in this
2834 * document allow. However, an SCTP transmitter MUST NOT be
2835 * more aggressive than the following algorithms allow.
2836 */
Frank Filz52ccb8e2005-12-22 11:36:46 -08002837 if (chunk->end_of_packet)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002838 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
2839
Linus Torvalds1da177e2005-04-16 15:20:36 -07002840 return SCTP_DISPOSITION_CONSUME;
2841
2842discard_force:
2843 /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2844 *
2845 * When a packet arrives with duplicate DATA chunk(s) and with
2846 * no new DATA chunk(s), the endpoint MUST immediately send a
2847 * SACK with no delay. If a packet arrives with duplicate
2848 * DATA chunk(s) bundled with new DATA chunks, the endpoint
2849 * MAY immediately send a SACK. Normally receipt of duplicate
2850 * DATA chunks will occur when the original SACK chunk was lost
2851 * and the peer's RTO has expired. The duplicate TSN number(s)
2852 * SHOULD be reported in the SACK as duplicate.
2853 */
2854 /* In our case, we split the MAY SACK advice up whether or not
2855 * the last chunk is a duplicate.'
2856 */
2857 if (chunk->end_of_packet)
2858 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
2859 return SCTP_DISPOSITION_DISCARD;
2860
2861discard_noforce:
Frank Filz52ccb8e2005-12-22 11:36:46 -08002862 if (chunk->end_of_packet)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002863 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
2864
Linus Torvalds1da177e2005-04-16 15:20:36 -07002865 return SCTP_DISPOSITION_DISCARD;
2866consume:
2867 return SCTP_DISPOSITION_CONSUME;
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002868
Linus Torvalds1da177e2005-04-16 15:20:36 -07002869}
2870
2871/*
2872 * sctp_sf_eat_data_fast_4_4
2873 *
2874 * Section: 4 (4)
2875 * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received
2876 * DATA chunks without delay.
2877 *
2878 * Verification Tag: 8.5 Verification Tag [Normal verification]
2879 * Inputs
2880 * (endpoint, asoc, chunk)
2881 *
2882 * Outputs
2883 * (asoc, reply_msg, msg_up, timers, counters)
2884 *
2885 * The return value is the disposition of the chunk.
2886 */
2887sctp_disposition_t sctp_sf_eat_data_fast_4_4(const struct sctp_endpoint *ep,
2888 const struct sctp_association *asoc,
2889 const sctp_subtype_t type,
2890 void *arg,
2891 sctp_cmd_seq_t *commands)
2892{
2893 struct sctp_chunk *chunk = arg;
2894 int error;
2895
2896 if (!sctp_vtag_verify(chunk, asoc)) {
2897 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
2898 SCTP_NULL());
2899 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2900 }
2901
2902 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
2903 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2904 commands);
2905
2906 error = sctp_eat_data(asoc, chunk, commands );
2907 switch (error) {
2908 case SCTP_IERROR_NO_ERROR:
2909 case SCTP_IERROR_HIGH_TSN:
2910 case SCTP_IERROR_DUP_TSN:
2911 case SCTP_IERROR_IGNORE_TSN:
2912 case SCTP_IERROR_BAD_STREAM:
2913 break;
2914 case SCTP_IERROR_NO_DATA:
2915 goto consume;
2916 default:
2917 BUG();
2918 }
2919
2920 /* Go a head and force a SACK, since we are shutting down. */
2921
2922 /* Implementor's Guide.
2923 *
2924 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
2925 * respond to each received packet containing one or more DATA chunk(s)
2926 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
2927 */
2928 if (chunk->end_of_packet) {
2929 /* We must delay the chunk creation since the cumulative
2930 * TSN has not been updated yet.
2931 */
2932 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
2933 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
2934 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2935 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2936 }
2937
2938consume:
2939 return SCTP_DISPOSITION_CONSUME;
2940}
2941
2942/*
2943 * Section: 6.2 Processing a Received SACK
2944 * D) Any time a SACK arrives, the endpoint performs the following:
2945 *
2946 * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point,
2947 * then drop the SACK. Since Cumulative TSN Ack is monotonically
2948 * increasing, a SACK whose Cumulative TSN Ack is less than the
2949 * Cumulative TSN Ack Point indicates an out-of-order SACK.
2950 *
2951 * ii) Set rwnd equal to the newly received a_rwnd minus the number
2952 * of bytes still outstanding after processing the Cumulative TSN Ack
2953 * and the Gap Ack Blocks.
2954 *
2955 * iii) If the SACK is missing a TSN that was previously
2956 * acknowledged via a Gap Ack Block (e.g., the data receiver
2957 * reneged on the data), then mark the corresponding DATA chunk
2958 * as available for retransmit: Mark it as missing for fast
2959 * retransmit as described in Section 7.2.4 and if no retransmit
2960 * timer is running for the destination address to which the DATA
2961 * chunk was originally transmitted, then T3-rtx is started for
2962 * that destination address.
2963 *
2964 * Verification Tag: 8.5 Verification Tag [Normal verification]
2965 *
2966 * Inputs
2967 * (endpoint, asoc, chunk)
2968 *
2969 * Outputs
2970 * (asoc, reply_msg, msg_up, timers, counters)
2971 *
2972 * The return value is the disposition of the chunk.
2973 */
2974sctp_disposition_t sctp_sf_eat_sack_6_2(const struct sctp_endpoint *ep,
2975 const struct sctp_association *asoc,
2976 const sctp_subtype_t type,
2977 void *arg,
2978 sctp_cmd_seq_t *commands)
2979{
2980 struct sctp_chunk *chunk = arg;
2981 sctp_sackhdr_t *sackh;
2982 __u32 ctsn;
2983
2984 if (!sctp_vtag_verify(chunk, asoc))
2985 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2986
2987 /* Make sure that the SACK chunk has a valid length. */
2988 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_sack_chunk_t)))
2989 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2990 commands);
2991
2992 /* Pull the SACK chunk from the data buffer */
2993 sackh = sctp_sm_pull_sack(chunk);
2994 /* Was this a bogus SACK? */
2995 if (!sackh)
2996 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2997 chunk->subh.sack_hdr = sackh;
2998 ctsn = ntohl(sackh->cum_tsn_ack);
2999
3000 /* i) If Cumulative TSN Ack is less than the Cumulative TSN
3001 * Ack Point, then drop the SACK. Since Cumulative TSN
3002 * Ack is monotonically increasing, a SACK whose
3003 * Cumulative TSN Ack is less than the Cumulative TSN Ack
3004 * Point indicates an out-of-order SACK.
3005 */
3006 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
3007 SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn);
3008 SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc->ctsn_ack_point);
3009 return SCTP_DISPOSITION_DISCARD;
3010 }
3011
Wei Yongjunaecedea2007-08-02 16:57:44 +08003012 /* If Cumulative TSN Ack beyond the max tsn currently
3013 * send, terminating the association and respond to the
3014 * sender with an ABORT.
3015 */
3016 if (!TSN_lt(ctsn, asoc->next_tsn))
3017 return sctp_sf_violation_ctsn(ep, asoc, type, arg, commands);
3018
Linus Torvalds1da177e2005-04-16 15:20:36 -07003019 /* Return this SACK for further processing. */
3020 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_SACKH(sackh));
3021
3022 /* Note: We do the rest of the work on the PROCESS_SACK
3023 * sideeffect.
3024 */
3025 return SCTP_DISPOSITION_CONSUME;
3026}
3027
3028/*
3029 * Generate an ABORT in response to a packet.
3030 *
Jerome Forissier047a2422005-04-28 11:58:43 -07003031 * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41
Linus Torvalds1da177e2005-04-16 15:20:36 -07003032 *
Jerome Forissier047a2422005-04-28 11:58:43 -07003033 * 8) The receiver should respond to the sender of the OOTB packet with
3034 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3035 * MUST fill in the Verification Tag field of the outbound packet
3036 * with the value found in the Verification Tag field of the OOTB
3037 * packet and set the T-bit in the Chunk Flags to indicate that the
3038 * Verification Tag is reflected. After sending this ABORT, the
3039 * receiver of the OOTB packet shall discard the OOTB packet and take
3040 * no further action.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003041 *
3042 * Verification Tag:
3043 *
3044 * The return value is the disposition of the chunk.
3045*/
Vlad Yasevichece25df2007-09-07 16:30:54 -04003046static sctp_disposition_t sctp_sf_tabort_8_4_8(const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003047 const struct sctp_association *asoc,
3048 const sctp_subtype_t type,
3049 void *arg,
3050 sctp_cmd_seq_t *commands)
3051{
3052 struct sctp_packet *packet = NULL;
3053 struct sctp_chunk *chunk = arg;
3054 struct sctp_chunk *abort;
3055
3056 packet = sctp_ootb_pkt_new(asoc, chunk);
3057
3058 if (packet) {
3059 /* Make an ABORT. The T bit will be set if the asoc
3060 * is NULL.
3061 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003062 abort = sctp_make_abort(asoc, chunk, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003063 if (!abort) {
3064 sctp_ootb_pkt_free(packet);
3065 return SCTP_DISPOSITION_NOMEM;
3066 }
3067
Jerome Forissier047a2422005-04-28 11:58:43 -07003068 /* Reflect vtag if T-Bit is set */
3069 if (sctp_test_T_bit(abort))
3070 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3071
Linus Torvalds1da177e2005-04-16 15:20:36 -07003072 /* Set the skb to the belonging sock for accounting. */
3073 abort->skb->sk = ep->base.sk;
3074
3075 sctp_packet_append_chunk(packet, abort);
3076
3077 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3078 SCTP_PACKET(packet));
3079
3080 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
3081
Vlad Yasevichd3f25962007-09-07 11:47:45 -04003082 sctp_sf_pdiscard(ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003083 return SCTP_DISPOSITION_CONSUME;
3084 }
3085
3086 return SCTP_DISPOSITION_NOMEM;
3087}
3088
3089/*
3090 * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR
3091 * event as ULP notification for each cause included in the chunk.
3092 *
3093 * API 5.3.1.3 - SCTP_REMOTE_ERROR
3094 *
3095 * The return value is the disposition of the chunk.
3096*/
3097sctp_disposition_t sctp_sf_operr_notify(const struct sctp_endpoint *ep,
3098 const struct sctp_association *asoc,
3099 const sctp_subtype_t type,
3100 void *arg,
3101 sctp_cmd_seq_t *commands)
3102{
3103 struct sctp_chunk *chunk = arg;
3104 struct sctp_ulpevent *ev;
3105
3106 if (!sctp_vtag_verify(chunk, asoc))
3107 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3108
3109 /* Make sure that the ERROR chunk has a valid length. */
3110 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
3111 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3112 commands);
3113
3114 while (chunk->chunk_end > chunk->skb->data) {
3115 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
3116 GFP_ATOMIC);
3117 if (!ev)
3118 goto nomem;
3119
3120 if (!sctp_add_cmd(commands, SCTP_CMD_EVENT_ULP,
3121 SCTP_ULPEVENT(ev))) {
3122 sctp_ulpevent_free(ev);
3123 goto nomem;
3124 }
3125
3126 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_OPERR,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003127 SCTP_CHUNK(chunk));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003128 }
3129 return SCTP_DISPOSITION_CONSUME;
3130
3131nomem:
3132 return SCTP_DISPOSITION_NOMEM;
3133}
3134
3135/*
3136 * Process an inbound SHUTDOWN ACK.
3137 *
3138 * From Section 9.2:
3139 * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3140 * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its
3141 * peer, and remove all record of the association.
3142 *
3143 * The return value is the disposition.
3144 */
3145sctp_disposition_t sctp_sf_do_9_2_final(const struct sctp_endpoint *ep,
3146 const struct sctp_association *asoc,
3147 const sctp_subtype_t type,
3148 void *arg,
3149 sctp_cmd_seq_t *commands)
3150{
3151 struct sctp_chunk *chunk = arg;
3152 struct sctp_chunk *reply;
3153 struct sctp_ulpevent *ev;
3154
3155 if (!sctp_vtag_verify(chunk, asoc))
3156 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3157
3158 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3159 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3160 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3161 commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003162 /* 10.2 H) SHUTDOWN COMPLETE notification
3163 *
3164 * When SCTP completes the shutdown procedures (section 9.2) this
3165 * notification is passed to the upper layer.
3166 */
3167 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
Vlad Yasevicha5a35e72007-03-23 11:34:08 -07003168 0, 0, 0, NULL, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003169 if (!ev)
3170 goto nomem;
3171
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07003172 /* ...send a SHUTDOWN COMPLETE chunk to its peer, */
3173 reply = sctp_make_shutdown_complete(asoc, chunk);
3174 if (!reply)
3175 goto nomem_chunk;
3176
3177 /* Do all the commands now (after allocation), so that we
3178 * have consistent state if memory allocation failes
3179 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003180 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
3181
3182 /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3183 * stop the T2-shutdown timer,
3184 */
3185 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3186 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3187
3188 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3189 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
3190
Linus Torvalds1da177e2005-04-16 15:20:36 -07003191 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3192 SCTP_STATE(SCTP_STATE_CLOSED));
3193 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
3194 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3195 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
3196
3197 /* ...and remove all record of the association. */
3198 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
3199 return SCTP_DISPOSITION_DELETE_TCB;
3200
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07003201nomem_chunk:
3202 sctp_ulpevent_free(ev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003203nomem:
3204 return SCTP_DISPOSITION_NOMEM;
3205}
3206
3207/*
Jerome Forissier047a2422005-04-28 11:58:43 -07003208 * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41.
3209 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003210 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3211 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3212 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3213 * packet must fill in the Verification Tag field of the outbound
3214 * packet with the Verification Tag received in the SHUTDOWN ACK and
Jerome Forissier047a2422005-04-28 11:58:43 -07003215 * set the T-bit in the Chunk Flags to indicate that the Verification
3216 * Tag is reflected.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003217 *
3218 * 8) The receiver should respond to the sender of the OOTB packet with
3219 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3220 * MUST fill in the Verification Tag field of the outbound packet
3221 * with the value found in the Verification Tag field of the OOTB
Jerome Forissier047a2422005-04-28 11:58:43 -07003222 * packet and set the T-bit in the Chunk Flags to indicate that the
3223 * Verification Tag is reflected. After sending this ABORT, the
3224 * receiver of the OOTB packet shall discard the OOTB packet and take
3225 * no further action.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003226 */
3227sctp_disposition_t sctp_sf_ootb(const struct sctp_endpoint *ep,
3228 const struct sctp_association *asoc,
3229 const sctp_subtype_t type,
3230 void *arg,
3231 sctp_cmd_seq_t *commands)
3232{
3233 struct sctp_chunk *chunk = arg;
3234 struct sk_buff *skb = chunk->skb;
3235 sctp_chunkhdr_t *ch;
3236 __u8 *ch_end;
3237 int ootb_shut_ack = 0;
3238
3239 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES);
3240
3241 ch = (sctp_chunkhdr_t *) chunk->chunk_hdr;
3242 do {
Vlad Yasevichece25df2007-09-07 16:30:54 -04003243 /* Report violation if the chunk is less then minimal */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003244 if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t))
Vlad Yasevichece25df2007-09-07 16:30:54 -04003245 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3246 commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003247
Vlad Yasevichece25df2007-09-07 16:30:54 -04003248 /* Now that we know we at least have a chunk header,
3249 * do things that are type appropriate.
3250 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003251 if (SCTP_CID_SHUTDOWN_ACK == ch->type)
3252 ootb_shut_ack = 1;
3253
3254 /* RFC 2960, Section 3.3.7
3255 * Moreover, under any circumstances, an endpoint that
3256 * receives an ABORT MUST NOT respond to that ABORT by
3257 * sending an ABORT of its own.
3258 */
3259 if (SCTP_CID_ABORT == ch->type)
3260 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003261
Vlad Yasevichece25df2007-09-07 16:30:54 -04003262 /* Report violation if chunk len overflows */
3263 ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
3264 if (ch_end > skb_tail_pointer(skb))
3265 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3266 commands);
3267
Linus Torvalds1da177e2005-04-16 15:20:36 -07003268 ch = (sctp_chunkhdr_t *) ch_end;
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07003269 } while (ch_end < skb_tail_pointer(skb));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003270
3271 if (ootb_shut_ack)
Vlad Yasevichd3f25962007-09-07 11:47:45 -04003272 return sctp_sf_shut_8_4_5(ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003273 else
Vlad Yasevichd3f25962007-09-07 11:47:45 -04003274 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003275}
3276
3277/*
3278 * Handle an "Out of the blue" SHUTDOWN ACK.
3279 *
Jerome Forissier047a2422005-04-28 11:58:43 -07003280 * Section: 8.4 5, sctpimpguide 2.41.
3281 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003282 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
Jerome Forissier047a2422005-04-28 11:58:43 -07003283 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3284 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3285 * packet must fill in the Verification Tag field of the outbound
3286 * packet with the Verification Tag received in the SHUTDOWN ACK and
3287 * set the T-bit in the Chunk Flags to indicate that the Verification
3288 * Tag is reflected.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003289 *
3290 * Inputs
3291 * (endpoint, asoc, type, arg, commands)
3292 *
3293 * Outputs
3294 * (sctp_disposition_t)
3295 *
3296 * The return value is the disposition of the chunk.
3297 */
3298static sctp_disposition_t sctp_sf_shut_8_4_5(const struct sctp_endpoint *ep,
3299 const struct sctp_association *asoc,
3300 const sctp_subtype_t type,
3301 void *arg,
3302 sctp_cmd_seq_t *commands)
3303{
3304 struct sctp_packet *packet = NULL;
3305 struct sctp_chunk *chunk = arg;
3306 struct sctp_chunk *shut;
3307
3308 packet = sctp_ootb_pkt_new(asoc, chunk);
3309
3310 if (packet) {
3311 /* Make an SHUTDOWN_COMPLETE.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003312 * The T bit will be set if the asoc is NULL.
3313 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003314 shut = sctp_make_shutdown_complete(asoc, chunk);
3315 if (!shut) {
3316 sctp_ootb_pkt_free(packet);
3317 return SCTP_DISPOSITION_NOMEM;
3318 }
3319
Jerome Forissier047a2422005-04-28 11:58:43 -07003320 /* Reflect vtag if T-Bit is set */
3321 if (sctp_test_T_bit(shut))
3322 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3323
Linus Torvalds1da177e2005-04-16 15:20:36 -07003324 /* Set the skb to the belonging sock for accounting. */
3325 shut->skb->sk = ep->base.sk;
3326
3327 sctp_packet_append_chunk(packet, shut);
3328
3329 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3330 SCTP_PACKET(packet));
3331
3332 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
3333
3334 /* If the chunk length is invalid, we don't want to process
3335 * the reset of the packet.
3336 */
3337 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3338 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3339
Vlad Yasevichd3f25962007-09-07 11:47:45 -04003340 /* We need to discard the rest of the packet to prevent
3341 * potential bomming attacks from additional bundled chunks.
3342 * This is documented in SCTP Threats ID.
3343 */
3344 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003345 }
3346
3347 return SCTP_DISPOSITION_NOMEM;
3348}
3349
3350/*
3351 * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state.
3352 *
3353 * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK
3354 * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the
3355 * procedures in section 8.4 SHOULD be followed, in other words it
3356 * should be treated as an Out Of The Blue packet.
3357 * [This means that we do NOT check the Verification Tag on these
3358 * chunks. --piggy ]
3359 *
3360 */
3361sctp_disposition_t sctp_sf_do_8_5_1_E_sa(const struct sctp_endpoint *ep,
3362 const struct sctp_association *asoc,
3363 const sctp_subtype_t type,
3364 void *arg,
3365 sctp_cmd_seq_t *commands)
3366{
Vlad Yasevichece25df2007-09-07 16:30:54 -04003367 struct sctp_chunk *chunk = arg;
3368
3369 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3370 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3371 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3372 commands);
3373
Linus Torvalds1da177e2005-04-16 15:20:36 -07003374 /* Although we do have an association in this case, it corresponds
3375 * to a restarted association. So the packet is treated as an OOTB
3376 * packet and the state function that handles OOTB SHUTDOWN_ACK is
3377 * called with a NULL association.
3378 */
3379 return sctp_sf_shut_8_4_5(ep, NULL, type, arg, commands);
3380}
3381
3382/* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */
3383sctp_disposition_t sctp_sf_do_asconf(const struct sctp_endpoint *ep,
3384 const struct sctp_association *asoc,
3385 const sctp_subtype_t type, void *arg,
3386 sctp_cmd_seq_t *commands)
3387{
3388 struct sctp_chunk *chunk = arg;
3389 struct sctp_chunk *asconf_ack = NULL;
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003390 struct sctp_paramhdr *err_param = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003391 sctp_addiphdr_t *hdr;
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003392 union sctp_addr_param *addr_param;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003393 __u32 serial;
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003394 int length;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003395
3396 if (!sctp_vtag_verify(chunk, asoc)) {
3397 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3398 SCTP_NULL());
3399 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3400 }
3401
3402 /* Make sure that the ASCONF ADDIP chunk has a valid length. */
3403 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_addip_chunk_t)))
3404 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3405 commands);
3406
3407 hdr = (sctp_addiphdr_t *)chunk->skb->data;
3408 serial = ntohl(hdr->serial);
3409
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003410 addr_param = (union sctp_addr_param *)hdr->params;
3411 length = ntohs(addr_param->p.length);
3412 if (length < sizeof(sctp_paramhdr_t))
3413 return sctp_sf_violation_paramlen(ep, asoc, type,
3414 (void *)addr_param, commands);
3415
3416 /* Verify the ASCONF chunk before processing it. */
3417 if (!sctp_verify_asconf(asoc,
3418 (sctp_paramhdr_t *)((void *)addr_param + length),
3419 (void *)chunk->chunk_end,
3420 &err_param))
3421 return sctp_sf_violation_paramlen(ep, asoc, type,
3422 (void *)&err_param, commands);
3423
Linus Torvalds1da177e2005-04-16 15:20:36 -07003424 /* ADDIP 4.2 C1) Compare the value of the serial number to the value
3425 * the endpoint stored in a new association variable
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003426 * 'Peer-Serial-Number'.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003427 */
3428 if (serial == asoc->peer.addip_serial + 1) {
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003429 /* ADDIP 4.2 C2) If the value found in the serial number is
Linus Torvalds1da177e2005-04-16 15:20:36 -07003430 * equal to the ('Peer-Serial-Number' + 1), the endpoint MUST
3431 * do V1-V5.
3432 */
3433 asconf_ack = sctp_process_asconf((struct sctp_association *)
3434 asoc, chunk);
3435 if (!asconf_ack)
3436 return SCTP_DISPOSITION_NOMEM;
3437 } else if (serial == asoc->peer.addip_serial) {
3438 /* ADDIP 4.2 C3) If the value found in the serial number is
3439 * equal to the value stored in the 'Peer-Serial-Number'
3440 * IMPLEMENTATION NOTE: As an optimization a receiver may wish
3441 * to save the last ASCONF-ACK for some predetermined period of
3442 * time and instead of re-processing the ASCONF (with the same
3443 * serial number) it may just re-transmit the ASCONF-ACK.
3444 */
3445 if (asoc->addip_last_asconf_ack)
3446 asconf_ack = asoc->addip_last_asconf_ack;
3447 else
3448 return SCTP_DISPOSITION_DISCARD;
3449 } else {
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003450 /* ADDIP 4.2 C4) Otherwise, the ASCONF Chunk is discarded since
Linus Torvalds1da177e2005-04-16 15:20:36 -07003451 * it must be either a stale packet or from an attacker.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003452 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003453 return SCTP_DISPOSITION_DISCARD;
3454 }
3455
3456 /* ADDIP 4.2 C5) In both cases C2 and C3 the ASCONF-ACK MUST be sent
3457 * back to the source address contained in the IP header of the ASCONF
3458 * being responded to.
3459 */
3460 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(asconf_ack));
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003461
Linus Torvalds1da177e2005-04-16 15:20:36 -07003462 return SCTP_DISPOSITION_CONSUME;
3463}
3464
3465/*
3466 * ADDIP Section 4.3 General rules for address manipulation
3467 * When building TLV parameters for the ASCONF Chunk that will add or
3468 * delete IP addresses the D0 to D13 rules should be applied:
3469 */
3470sctp_disposition_t sctp_sf_do_asconf_ack(const struct sctp_endpoint *ep,
3471 const struct sctp_association *asoc,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003472 const sctp_subtype_t type, void *arg,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003473 sctp_cmd_seq_t *commands)
3474{
3475 struct sctp_chunk *asconf_ack = arg;
3476 struct sctp_chunk *last_asconf = asoc->addip_last_asconf;
3477 struct sctp_chunk *abort;
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003478 struct sctp_paramhdr *err_param = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003479 sctp_addiphdr_t *addip_hdr;
3480 __u32 sent_serial, rcvd_serial;
3481
3482 if (!sctp_vtag_verify(asconf_ack, asoc)) {
3483 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3484 SCTP_NULL());
3485 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3486 }
3487
3488 /* Make sure that the ADDIP chunk has a valid length. */
3489 if (!sctp_chunk_length_valid(asconf_ack, sizeof(sctp_addip_chunk_t)))
3490 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3491 commands);
3492
3493 addip_hdr = (sctp_addiphdr_t *)asconf_ack->skb->data;
3494 rcvd_serial = ntohl(addip_hdr->serial);
3495
Wei Yongjun6f4c6182007-09-19 17:19:52 +08003496 /* Verify the ASCONF-ACK chunk before processing it. */
3497 if (!sctp_verify_asconf(asoc,
3498 (sctp_paramhdr_t *)addip_hdr->params,
3499 (void *)asconf_ack->chunk_end,
3500 &err_param))
3501 return sctp_sf_violation_paramlen(ep, asoc, type,
3502 (void *)&err_param, commands);
3503
Linus Torvalds1da177e2005-04-16 15:20:36 -07003504 if (last_asconf) {
3505 addip_hdr = (sctp_addiphdr_t *)last_asconf->subh.addip_hdr;
3506 sent_serial = ntohl(addip_hdr->serial);
3507 } else {
3508 sent_serial = asoc->addip_serial - 1;
3509 }
3510
3511 /* D0) If an endpoint receives an ASCONF-ACK that is greater than or
3512 * equal to the next serial number to be used but no ASCONF chunk is
3513 * outstanding the endpoint MUST ABORT the association. Note that a
3514 * sequence number is greater than if it is no more than 2^^31-1
3515 * larger than the current sequence number (using serial arithmetic).
3516 */
3517 if (ADDIP_SERIAL_gte(rcvd_serial, sent_serial + 1) &&
3518 !(asoc->addip_last_asconf)) {
3519 abort = sctp_make_abort(asoc, asconf_ack,
3520 sizeof(sctp_errhdr_t));
3521 if (abort) {
Wei Yongjun00f1c2d2007-08-21 15:50:01 +08003522 sctp_init_cause(abort, SCTP_ERROR_ASCONF_ACK, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003523 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3524 SCTP_CHUNK(abort));
3525 }
3526 /* We are going to ABORT, so we might as well stop
3527 * processing the rest of the chunks in the packet.
3528 */
3529 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3530 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3531 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07003532 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003533 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003534 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08003535 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003536 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
3537 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3538 return SCTP_DISPOSITION_ABORT;
3539 }
3540
3541 if ((rcvd_serial == sent_serial) && asoc->addip_last_asconf) {
3542 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3543 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3544
3545 if (!sctp_process_asconf_ack((struct sctp_association *)asoc,
3546 asconf_ack))
3547 return SCTP_DISPOSITION_CONSUME;
3548
3549 abort = sctp_make_abort(asoc, asconf_ack,
3550 sizeof(sctp_errhdr_t));
3551 if (abort) {
Wei Yongjun00f1c2d2007-08-21 15:50:01 +08003552 sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003553 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3554 SCTP_CHUNK(abort));
3555 }
3556 /* We are going to ABORT, so we might as well stop
3557 * processing the rest of the chunks in the packet.
3558 */
3559 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07003560 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003561 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003562 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08003563 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003564 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
3565 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3566 return SCTP_DISPOSITION_ABORT;
3567 }
3568
3569 return SCTP_DISPOSITION_DISCARD;
3570}
3571
3572/*
3573 * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP
3574 *
3575 * When a FORWARD TSN chunk arrives, the data receiver MUST first update
3576 * its cumulative TSN point to the value carried in the FORWARD TSN
3577 * chunk, and then MUST further advance its cumulative TSN point locally
3578 * if possible.
3579 * After the above processing, the data receiver MUST stop reporting any
3580 * missing TSNs earlier than or equal to the new cumulative TSN point.
3581 *
3582 * Verification Tag: 8.5 Verification Tag [Normal verification]
3583 *
3584 * The return value is the disposition of the chunk.
3585 */
3586sctp_disposition_t sctp_sf_eat_fwd_tsn(const struct sctp_endpoint *ep,
3587 const struct sctp_association *asoc,
3588 const sctp_subtype_t type,
3589 void *arg,
3590 sctp_cmd_seq_t *commands)
3591{
3592 struct sctp_chunk *chunk = arg;
3593 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
3594 __u16 len;
3595 __u32 tsn;
3596
3597 if (!sctp_vtag_verify(chunk, asoc)) {
3598 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3599 SCTP_NULL());
3600 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3601 }
3602
3603 /* Make sure that the FORWARD_TSN chunk has valid length. */
3604 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
3605 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3606 commands);
3607
3608 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3609 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3610 len = ntohs(chunk->chunk_hdr->length);
3611 len -= sizeof(struct sctp_chunkhdr);
3612 skb_pull(chunk->skb, len);
3613
3614 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
3615 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __FUNCTION__, tsn);
3616
3617 /* The TSN is too high--silently discard the chunk and count on it
3618 * getting retransmitted later.
3619 */
3620 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3621 goto discard_noforce;
3622
3623 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3624 if (len > sizeof(struct sctp_fwdtsn_hdr))
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003625 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003626 SCTP_CHUNK(chunk));
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003627
Linus Torvalds1da177e2005-04-16 15:20:36 -07003628 /* Count this as receiving DATA. */
3629 if (asoc->autoclose) {
3630 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3631 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
3632 }
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003633
Linus Torvalds1da177e2005-04-16 15:20:36 -07003634 /* FIXME: For now send a SACK, but DATA processing may
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003635 * send another.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003636 */
3637 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
Linus Torvalds1da177e2005-04-16 15:20:36 -07003638
3639 return SCTP_DISPOSITION_CONSUME;
3640
3641discard_noforce:
3642 return SCTP_DISPOSITION_DISCARD;
3643}
3644
3645sctp_disposition_t sctp_sf_eat_fwd_tsn_fast(
3646 const struct sctp_endpoint *ep,
3647 const struct sctp_association *asoc,
3648 const sctp_subtype_t type,
3649 void *arg,
3650 sctp_cmd_seq_t *commands)
3651{
3652 struct sctp_chunk *chunk = arg;
3653 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
3654 __u16 len;
3655 __u32 tsn;
3656
3657 if (!sctp_vtag_verify(chunk, asoc)) {
3658 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3659 SCTP_NULL());
3660 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3661 }
3662
3663 /* Make sure that the FORWARD_TSN chunk has a valid length. */
3664 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
3665 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3666 commands);
3667
3668 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3669 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3670 len = ntohs(chunk->chunk_hdr->length);
3671 len -= sizeof(struct sctp_chunkhdr);
3672 skb_pull(chunk->skb, len);
3673
3674 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
3675 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __FUNCTION__, tsn);
3676
3677 /* The TSN is too high--silently discard the chunk and count on it
3678 * getting retransmitted later.
3679 */
3680 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3681 goto gen_shutdown;
3682
3683 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3684 if (len > sizeof(struct sctp_fwdtsn_hdr))
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003685 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003686 SCTP_CHUNK(chunk));
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003687
Linus Torvalds1da177e2005-04-16 15:20:36 -07003688 /* Go a head and force a SACK, since we are shutting down. */
3689gen_shutdown:
3690 /* Implementor's Guide.
3691 *
3692 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3693 * respond to each received packet containing one or more DATA chunk(s)
3694 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3695 */
3696 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
3697 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3698 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3699 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3700
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003701 return SCTP_DISPOSITION_CONSUME;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003702}
3703
3704/*
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07003705 * SCTP-AUTH Section 6.3 Receving authenticated chukns
3706 *
3707 * The receiver MUST use the HMAC algorithm indicated in the HMAC
3708 * Identifier field. If this algorithm was not specified by the
3709 * receiver in the HMAC-ALGO parameter in the INIT or INIT-ACK chunk
3710 * during association setup, the AUTH chunk and all chunks after it MUST
3711 * be discarded and an ERROR chunk SHOULD be sent with the error cause
3712 * defined in Section 4.1.
3713 *
3714 * If an endpoint with no shared key receives a Shared Key Identifier
3715 * other than 0, it MUST silently discard all authenticated chunks. If
3716 * the endpoint has at least one endpoint pair shared key for the peer,
3717 * it MUST use the key specified by the Shared Key Identifier if a
3718 * key has been configured for that Shared Key Identifier. If no
3719 * endpoint pair shared key has been configured for that Shared Key
3720 * Identifier, all authenticated chunks MUST be silently discarded.
3721 *
3722 * Verification Tag: 8.5 Verification Tag [Normal verification]
3723 *
3724 * The return value is the disposition of the chunk.
3725 */
3726static sctp_ierror_t sctp_sf_authenticate(const struct sctp_endpoint *ep,
3727 const struct sctp_association *asoc,
3728 const sctp_subtype_t type,
3729 struct sctp_chunk *chunk)
3730{
3731 struct sctp_authhdr *auth_hdr;
3732 struct sctp_hmac *hmac;
3733 unsigned int sig_len;
3734 __u16 key_id;
3735 __u8 *save_digest;
3736 __u8 *digest;
3737
3738 /* Pull in the auth header, so we can do some more verification */
3739 auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
3740 chunk->subh.auth_hdr = auth_hdr;
3741 skb_pull(chunk->skb, sizeof(struct sctp_authhdr));
3742
3743 /* Make sure that we suport the HMAC algorithm from the auth
3744 * chunk.
3745 */
3746 if (!sctp_auth_asoc_verify_hmac_id(asoc, auth_hdr->hmac_id))
3747 return SCTP_IERROR_AUTH_BAD_HMAC;
3748
3749 /* Make sure that the provided shared key identifier has been
3750 * configured
3751 */
3752 key_id = ntohs(auth_hdr->shkey_id);
3753 if (key_id != asoc->active_key_id && !sctp_auth_get_shkey(asoc, key_id))
3754 return SCTP_IERROR_AUTH_BAD_KEYID;
3755
3756
3757 /* Make sure that the length of the signature matches what
3758 * we expect.
3759 */
3760 sig_len = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_auth_chunk_t);
3761 hmac = sctp_auth_get_hmac(ntohs(auth_hdr->hmac_id));
3762 if (sig_len != hmac->hmac_len)
3763 return SCTP_IERROR_PROTO_VIOLATION;
3764
3765 /* Now that we've done validation checks, we can compute and
3766 * verify the hmac. The steps involved are:
3767 * 1. Save the digest from the chunk.
3768 * 2. Zero out the digest in the chunk.
3769 * 3. Compute the new digest
3770 * 4. Compare saved and new digests.
3771 */
3772 digest = auth_hdr->hmac;
3773 skb_pull(chunk->skb, sig_len);
3774
3775 save_digest = kmemdup(digest, sig_len, GFP_ATOMIC);
3776 if (!save_digest)
3777 goto nomem;
3778
3779 memset(digest, 0, sig_len);
3780
3781 sctp_auth_calculate_hmac(asoc, chunk->skb,
3782 (struct sctp_auth_chunk *)chunk->chunk_hdr,
3783 GFP_ATOMIC);
3784
3785 /* Discard the packet if the digests do not match */
3786 if (memcmp(save_digest, digest, sig_len)) {
3787 kfree(save_digest);
3788 return SCTP_IERROR_BAD_SIG;
3789 }
3790
3791 kfree(save_digest);
3792 chunk->auth = 1;
3793
3794 return SCTP_IERROR_NO_ERROR;
3795nomem:
3796 return SCTP_IERROR_NOMEM;
3797}
3798
3799sctp_disposition_t sctp_sf_eat_auth(const struct sctp_endpoint *ep,
3800 const struct sctp_association *asoc,
3801 const sctp_subtype_t type,
3802 void *arg,
3803 sctp_cmd_seq_t *commands)
3804{
3805 struct sctp_authhdr *auth_hdr;
3806 struct sctp_chunk *chunk = arg;
3807 struct sctp_chunk *err_chunk;
3808 sctp_ierror_t error;
3809
3810 if (!sctp_vtag_verify(chunk, asoc)) {
3811 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3812 SCTP_NULL());
3813 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3814 }
3815
3816 /* Make sure that the AUTH chunk has valid length. */
3817 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_auth_chunk)))
3818 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3819 commands);
3820
3821 auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
3822 error = sctp_sf_authenticate(ep, asoc, type, chunk);
3823 switch (error) {
3824 case SCTP_IERROR_AUTH_BAD_HMAC:
3825 /* Generate the ERROR chunk and discard the rest
3826 * of the packet
3827 */
3828 err_chunk = sctp_make_op_error(asoc, chunk,
3829 SCTP_ERROR_UNSUP_HMAC,
3830 &auth_hdr->hmac_id,
3831 sizeof(__u16));
3832 if (err_chunk) {
3833 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3834 SCTP_CHUNK(err_chunk));
3835 }
3836 /* Fall Through */
3837 case SCTP_IERROR_AUTH_BAD_KEYID:
3838 case SCTP_IERROR_BAD_SIG:
3839 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3840 break;
3841 case SCTP_IERROR_PROTO_VIOLATION:
3842 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3843 commands);
3844 break;
3845 case SCTP_IERROR_NOMEM:
3846 return SCTP_DISPOSITION_NOMEM;
3847 default:
3848 break;
3849 }
3850
Vlad Yasevich65b07e52007-09-16 19:34:00 -07003851 if (asoc->active_key_id != ntohs(auth_hdr->shkey_id)) {
3852 struct sctp_ulpevent *ev;
3853
3854 ev = sctp_ulpevent_make_authkey(asoc, ntohs(auth_hdr->shkey_id),
3855 SCTP_AUTH_NEWKEY, GFP_ATOMIC);
3856
3857 if (!ev)
3858 return -ENOMEM;
3859
3860 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
3861 SCTP_ULPEVENT(ev));
3862 }
3863
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07003864 return SCTP_DISPOSITION_CONSUME;
3865}
3866
3867/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07003868 * Process an unknown chunk.
3869 *
3870 * Section: 3.2. Also, 2.1 in the implementor's guide.
3871 *
3872 * Chunk Types are encoded such that the highest-order two bits specify
3873 * the action that must be taken if the processing endpoint does not
3874 * recognize the Chunk Type.
3875 *
3876 * 00 - Stop processing this SCTP packet and discard it, do not process
3877 * any further chunks within it.
3878 *
3879 * 01 - Stop processing this SCTP packet and discard it, do not process
3880 * any further chunks within it, and report the unrecognized
3881 * chunk in an 'Unrecognized Chunk Type'.
3882 *
3883 * 10 - Skip this chunk and continue processing.
3884 *
3885 * 11 - Skip this chunk and continue processing, but report in an ERROR
3886 * Chunk using the 'Unrecognized Chunk Type' cause of error.
3887 *
3888 * The return value is the disposition of the chunk.
3889 */
3890sctp_disposition_t sctp_sf_unk_chunk(const struct sctp_endpoint *ep,
3891 const struct sctp_association *asoc,
3892 const sctp_subtype_t type,
3893 void *arg,
3894 sctp_cmd_seq_t *commands)
3895{
3896 struct sctp_chunk *unk_chunk = arg;
3897 struct sctp_chunk *err_chunk;
3898 sctp_chunkhdr_t *hdr;
3899
3900 SCTP_DEBUG_PRINTK("Processing the unknown chunk id %d.\n", type.chunk);
3901
3902 if (!sctp_vtag_verify(unk_chunk, asoc))
3903 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3904
3905 /* Make sure that the chunk has a valid length.
3906 * Since we don't know the chunk type, we use a general
3907 * chunkhdr structure to make a comparison.
3908 */
3909 if (!sctp_chunk_length_valid(unk_chunk, sizeof(sctp_chunkhdr_t)))
3910 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3911 commands);
3912
3913 switch (type.chunk & SCTP_CID_ACTION_MASK) {
3914 case SCTP_CID_ACTION_DISCARD:
3915 /* Discard the packet. */
3916 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3917 break;
3918 case SCTP_CID_ACTION_DISCARD_ERR:
3919 /* Discard the packet. */
3920 sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3921
3922 /* Generate an ERROR chunk as response. */
3923 hdr = unk_chunk->chunk_hdr;
3924 err_chunk = sctp_make_op_error(asoc, unk_chunk,
3925 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
3926 WORD_ROUND(ntohs(hdr->length)));
3927 if (err_chunk) {
3928 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3929 SCTP_CHUNK(err_chunk));
3930 }
3931 return SCTP_DISPOSITION_CONSUME;
3932 break;
3933 case SCTP_CID_ACTION_SKIP:
3934 /* Skip the chunk. */
3935 return SCTP_DISPOSITION_DISCARD;
3936 break;
3937 case SCTP_CID_ACTION_SKIP_ERR:
3938 /* Generate an ERROR chunk as response. */
3939 hdr = unk_chunk->chunk_hdr;
3940 err_chunk = sctp_make_op_error(asoc, unk_chunk,
3941 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
3942 WORD_ROUND(ntohs(hdr->length)));
3943 if (err_chunk) {
3944 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3945 SCTP_CHUNK(err_chunk));
3946 }
3947 /* Skip the chunk. */
3948 return SCTP_DISPOSITION_CONSUME;
3949 break;
3950 default:
3951 break;
3952 }
3953
3954 return SCTP_DISPOSITION_DISCARD;
3955}
3956
3957/*
3958 * Discard the chunk.
3959 *
3960 * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2
3961 * [Too numerous to mention...]
3962 * Verification Tag: No verification needed.
3963 * Inputs
3964 * (endpoint, asoc, chunk)
3965 *
3966 * Outputs
3967 * (asoc, reply_msg, msg_up, timers, counters)
3968 *
3969 * The return value is the disposition of the chunk.
3970 */
3971sctp_disposition_t sctp_sf_discard_chunk(const struct sctp_endpoint *ep,
3972 const struct sctp_association *asoc,
3973 const sctp_subtype_t type,
3974 void *arg,
3975 sctp_cmd_seq_t *commands)
3976{
Vlad Yasevichece25df2007-09-07 16:30:54 -04003977 struct sctp_chunk *chunk = arg;
3978
3979 /* Make sure that the chunk has a valid length.
3980 * Since we don't know the chunk type, we use a general
3981 * chunkhdr structure to make a comparison.
3982 */
3983 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3984 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3985 commands);
3986
Linus Torvalds1da177e2005-04-16 15:20:36 -07003987 SCTP_DEBUG_PRINTK("Chunk %d is discarded\n", type.chunk);
3988 return SCTP_DISPOSITION_DISCARD;
3989}
3990
3991/*
3992 * Discard the whole packet.
3993 *
3994 * Section: 8.4 2)
3995 *
3996 * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST
3997 * silently discard the OOTB packet and take no further action.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003998 *
3999 * Verification Tag: No verification necessary
4000 *
4001 * Inputs
4002 * (endpoint, asoc, chunk)
4003 *
4004 * Outputs
4005 * (asoc, reply_msg, msg_up, timers, counters)
4006 *
4007 * The return value is the disposition of the chunk.
4008 */
4009sctp_disposition_t sctp_sf_pdiscard(const struct sctp_endpoint *ep,
4010 const struct sctp_association *asoc,
4011 const sctp_subtype_t type,
4012 void *arg,
4013 sctp_cmd_seq_t *commands)
4014{
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07004015 SCTP_INC_STATS(SCTP_MIB_IN_PKT_DISCARDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004016 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
4017
4018 return SCTP_DISPOSITION_CONSUME;
4019}
4020
4021
4022/*
4023 * The other end is violating protocol.
4024 *
4025 * Section: Not specified
4026 * Verification Tag: Not specified
4027 * Inputs
4028 * (endpoint, asoc, chunk)
4029 *
4030 * Outputs
4031 * (asoc, reply_msg, msg_up, timers, counters)
4032 *
4033 * We simply tag the chunk as a violation. The state machine will log
4034 * the violation and continue.
4035 */
4036sctp_disposition_t sctp_sf_violation(const struct sctp_endpoint *ep,
4037 const struct sctp_association *asoc,
4038 const sctp_subtype_t type,
4039 void *arg,
4040 sctp_cmd_seq_t *commands)
4041{
Vlad Yasevichece25df2007-09-07 16:30:54 -04004042 struct sctp_chunk *chunk = arg;
4043
4044 /* Make sure that the chunk has a valid length. */
4045 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
4046 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
4047 commands);
4048
Linus Torvalds1da177e2005-04-16 15:20:36 -07004049 return SCTP_DISPOSITION_VIOLATION;
4050}
4051
Linus Torvalds1da177e2005-04-16 15:20:36 -07004052/*
Wei Yongjunaecedea2007-08-02 16:57:44 +08004053 * Common function to handle a protocol violation.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004054 */
Wei Yongjunaecedea2007-08-02 16:57:44 +08004055static sctp_disposition_t sctp_sf_abort_violation(
Vlad Yasevichece25df2007-09-07 16:30:54 -04004056 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07004057 const struct sctp_association *asoc,
Linus Torvalds1da177e2005-04-16 15:20:36 -07004058 void *arg,
Wei Yongjunaecedea2007-08-02 16:57:44 +08004059 sctp_cmd_seq_t *commands,
4060 const __u8 *payload,
4061 const size_t paylen)
Linus Torvalds1da177e2005-04-16 15:20:36 -07004062{
Vlad Yasevichece25df2007-09-07 16:30:54 -04004063 struct sctp_packet *packet = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004064 struct sctp_chunk *chunk = arg;
4065 struct sctp_chunk *abort = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004066
4067 /* Make the abort chunk. */
Wei Yongjunaecedea2007-08-02 16:57:44 +08004068 abort = sctp_make_abort_violation(asoc, chunk, payload, paylen);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004069 if (!abort)
4070 goto nomem;
4071
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07004072 /* SCTP-AUTH, Section 6.3:
4073 * It should be noted that if the receiver wants to tear
4074 * down an association in an authenticated way only, the
4075 * handling of malformed packets should not result in
4076 * tearing down the association.
4077 *
4078 * This means that if we only want to abort associations
4079 * in an authenticated way (i.e AUTH+ABORT), then we
4080 * can't destory this association just becuase the packet
4081 * was malformed.
4082 */
4083 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
4084 goto discard;
4085
Vlad Yasevichece25df2007-09-07 16:30:54 -04004086 if (asoc) {
4087 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4088 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004089
Vlad Yasevichece25df2007-09-07 16:30:54 -04004090 if (asoc->state <= SCTP_STATE_COOKIE_ECHOED) {
4091 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4092 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4093 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4094 SCTP_ERROR(ECONNREFUSED));
4095 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
4096 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4097 } else {
4098 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4099 SCTP_ERROR(ECONNABORTED));
4100 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4101 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4102 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
4103 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07004104 } else {
Vlad Yasevichece25df2007-09-07 16:30:54 -04004105 packet = sctp_ootb_pkt_new(asoc, chunk);
4106
4107 if (!packet)
4108 goto nomem_pkt;
4109
4110 if (sctp_test_T_bit(abort))
4111 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
4112
4113 abort->skb->sk = ep->base.sk;
4114
4115 sctp_packet_append_chunk(packet, abort);
4116
4117 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
4118 SCTP_PACKET(packet));
4119
4120 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004121 }
4122
Vlad Yasevichbbd0d592007-10-03 17:51:34 -07004123discard:
Vlad Yasevichece25df2007-09-07 16:30:54 -04004124 sctp_sf_pdiscard(ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004125
4126 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09004127
Linus Torvalds1da177e2005-04-16 15:20:36 -07004128 return SCTP_DISPOSITION_ABORT;
4129
Vlad Yasevichece25df2007-09-07 16:30:54 -04004130nomem_pkt:
4131 sctp_chunk_free(abort);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004132nomem:
4133 return SCTP_DISPOSITION_NOMEM;
4134}
4135
Wei Yongjunaecedea2007-08-02 16:57:44 +08004136/*
4137 * Handle a protocol violation when the chunk length is invalid.
4138 * "Invalid" length is identified as smaller then the minimal length a
4139 * given chunk can be. For example, a SACK chunk has invalid length
4140 * if it's length is set to be smaller then the size of sctp_sack_chunk_t.
4141 *
4142 * We inform the other end by sending an ABORT with a Protocol Violation
4143 * error code.
4144 *
4145 * Section: Not specified
4146 * Verification Tag: Nothing to do
4147 * Inputs
4148 * (endpoint, asoc, chunk)
4149 *
4150 * Outputs
4151 * (reply_msg, msg_up, counters)
4152 *
4153 * Generate an ABORT chunk and terminate the association.
4154 */
4155static sctp_disposition_t sctp_sf_violation_chunklen(
4156 const struct sctp_endpoint *ep,
4157 const struct sctp_association *asoc,
4158 const sctp_subtype_t type,
4159 void *arg,
4160 sctp_cmd_seq_t *commands)
4161{
4162 char err_str[]="The following chunk had invalid length:";
4163
Vlad Yasevichece25df2007-09-07 16:30:54 -04004164 return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
Wei Yongjunaecedea2007-08-02 16:57:44 +08004165 sizeof(err_str));
4166}
4167
Wei Yongjun6f4c6182007-09-19 17:19:52 +08004168/*
4169 * Handle a protocol violation when the parameter length is invalid.
4170 * "Invalid" length is identified as smaller then the minimal length a
4171 * given parameter can be.
4172 */
4173static sctp_disposition_t sctp_sf_violation_paramlen(
4174 const struct sctp_endpoint *ep,
4175 const struct sctp_association *asoc,
4176 const sctp_subtype_t type,
4177 void *arg,
4178 sctp_cmd_seq_t *commands) {
4179 char err_str[] = "The following parameter had invalid length:";
4180
4181 return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
4182 sizeof(err_str));
4183}
4184
Wei Yongjunaecedea2007-08-02 16:57:44 +08004185/* Handle a protocol violation when the peer trying to advance the
4186 * cumulative tsn ack to a point beyond the max tsn currently sent.
4187 *
4188 * We inform the other end by sending an ABORT with a Protocol Violation
4189 * error code.
4190 */
4191static sctp_disposition_t sctp_sf_violation_ctsn(
4192 const struct sctp_endpoint *ep,
4193 const struct sctp_association *asoc,
4194 const sctp_subtype_t type,
4195 void *arg,
4196 sctp_cmd_seq_t *commands)
4197{
4198 char err_str[]="The cumulative tsn ack beyond the max tsn currently sent:";
4199
Vlad Yasevichece25df2007-09-07 16:30:54 -04004200 return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
Wei Yongjunaecedea2007-08-02 16:57:44 +08004201 sizeof(err_str));
4202}
4203
Vlad Yasevichece25df2007-09-07 16:30:54 -04004204/* Handle protocol violation of an invalid chunk bundling. For example,
4205 * when we have an association and we recieve bundled INIT-ACK, or
4206 * SHUDOWN-COMPLETE, our peer is clearly violationg the "MUST NOT bundle"
4207 * statement from the specs. Additinally, there might be an attacker
4208 * on the path and we may not want to continue this communication.
4209 */
4210static sctp_disposition_t sctp_sf_violation_chunk(
4211 const struct sctp_endpoint *ep,
4212 const struct sctp_association *asoc,
4213 const sctp_subtype_t type,
4214 void *arg,
4215 sctp_cmd_seq_t *commands)
4216{
4217 char err_str[]="The following chunk violates protocol:";
4218
4219 if (!asoc)
4220 return sctp_sf_violation(ep, asoc, type, arg, commands);
4221
4222 return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
4223 sizeof(err_str));
4224}
Linus Torvalds1da177e2005-04-16 15:20:36 -07004225/***************************************************************************
4226 * These are the state functions for handling primitive (Section 10) events.
4227 ***************************************************************************/
4228/*
4229 * sctp_sf_do_prm_asoc
4230 *
4231 * Section: 10.1 ULP-to-SCTP
4232 * B) Associate
4233 *
4234 * Format: ASSOCIATE(local SCTP instance name, destination transport addr,
4235 * outbound stream count)
4236 * -> association id [,destination transport addr list] [,outbound stream
4237 * count]
4238 *
4239 * This primitive allows the upper layer to initiate an association to a
4240 * specific peer endpoint.
4241 *
4242 * The peer endpoint shall be specified by one of the transport addresses
4243 * which defines the endpoint (see Section 1.4). If the local SCTP
4244 * instance has not been initialized, the ASSOCIATE is considered an
4245 * error.
4246 * [This is not relevant for the kernel implementation since we do all
4247 * initialization at boot time. It we hadn't initialized we wouldn't
4248 * get anywhere near this code.]
4249 *
4250 * An association id, which is a local handle to the SCTP association,
4251 * will be returned on successful establishment of the association. If
4252 * SCTP is not able to open an SCTP association with the peer endpoint,
4253 * an error is returned.
4254 * [In the kernel implementation, the struct sctp_association needs to
4255 * be created BEFORE causing this primitive to run.]
4256 *
4257 * Other association parameters may be returned, including the
4258 * complete destination transport addresses of the peer as well as the
4259 * outbound stream count of the local endpoint. One of the transport
4260 * address from the returned destination addresses will be selected by
4261 * the local endpoint as default primary path for sending SCTP packets
4262 * to this peer. The returned "destination transport addr list" can
4263 * be used by the ULP to change the default primary path or to force
4264 * sending a packet to a specific transport address. [All of this
4265 * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING
4266 * function.]
4267 *
4268 * Mandatory attributes:
4269 *
4270 * o local SCTP instance name - obtained from the INITIALIZE operation.
4271 * [This is the argument asoc.]
4272 * o destination transport addr - specified as one of the transport
4273 * addresses of the peer endpoint with which the association is to be
4274 * established.
4275 * [This is asoc->peer.active_path.]
4276 * o outbound stream count - the number of outbound streams the ULP
4277 * would like to open towards this peer endpoint.
4278 * [BUG: This is not currently implemented.]
4279 * Optional attributes:
4280 *
4281 * None.
4282 *
4283 * The return value is a disposition.
4284 */
4285sctp_disposition_t sctp_sf_do_prm_asoc(const struct sctp_endpoint *ep,
4286 const struct sctp_association *asoc,
4287 const sctp_subtype_t type,
4288 void *arg,
4289 sctp_cmd_seq_t *commands)
4290{
4291 struct sctp_chunk *repl;
4292
4293 /* The comment below says that we enter COOKIE-WAIT AFTER
4294 * sending the INIT, but that doesn't actually work in our
4295 * implementation...
4296 */
4297 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4298 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
4299
4300 /* RFC 2960 5.1 Normal Establishment of an Association
4301 *
4302 * A) "A" first sends an INIT chunk to "Z". In the INIT, "A"
4303 * must provide its Verification Tag (Tag_A) in the Initiate
4304 * Tag field. Tag_A SHOULD be a random number in the range of
4305 * 1 to 4294967295 (see 5.3.1 for Tag value selection). ...
4306 */
4307
4308 repl = sctp_make_init(asoc, &asoc->base.bind_addr, GFP_ATOMIC, 0);
4309 if (!repl)
4310 goto nomem;
4311
4312 /* Cast away the const modifier, as we want to just
4313 * rerun it through as a sideffect.
4314 */
4315 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC,
4316 SCTP_ASOC((struct sctp_association *) asoc));
4317
Frank Filz3f7a87d2005-06-20 13:14:57 -07004318 /* Choose transport for INIT. */
4319 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
4320 SCTP_CHUNK(repl));
4321
Linus Torvalds1da177e2005-04-16 15:20:36 -07004322 /* After sending the INIT, "A" starts the T1-init timer and
4323 * enters the COOKIE-WAIT state.
4324 */
4325 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4326 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4327 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
4328 return SCTP_DISPOSITION_CONSUME;
4329
4330nomem:
4331 return SCTP_DISPOSITION_NOMEM;
4332}
4333
4334/*
4335 * Process the SEND primitive.
4336 *
4337 * Section: 10.1 ULP-to-SCTP
4338 * E) Send
4339 *
4340 * Format: SEND(association id, buffer address, byte count [,context]
4341 * [,stream id] [,life time] [,destination transport address]
4342 * [,unorder flag] [,no-bundle flag] [,payload protocol-id] )
4343 * -> result
4344 *
4345 * This is the main method to send user data via SCTP.
4346 *
4347 * Mandatory attributes:
4348 *
4349 * o association id - local handle to the SCTP association
4350 *
4351 * o buffer address - the location where the user message to be
4352 * transmitted is stored;
4353 *
4354 * o byte count - The size of the user data in number of bytes;
4355 *
4356 * Optional attributes:
4357 *
4358 * o context - an optional 32 bit integer that will be carried in the
4359 * sending failure notification to the ULP if the transportation of
4360 * this User Message fails.
4361 *
4362 * o stream id - to indicate which stream to send the data on. If not
4363 * specified, stream 0 will be used.
4364 *
4365 * o life time - specifies the life time of the user data. The user data
4366 * will not be sent by SCTP after the life time expires. This
4367 * parameter can be used to avoid efforts to transmit stale
4368 * user messages. SCTP notifies the ULP if the data cannot be
4369 * initiated to transport (i.e. sent to the destination via SCTP's
4370 * send primitive) within the life time variable. However, the
4371 * user data will be transmitted if SCTP has attempted to transmit a
4372 * chunk before the life time expired.
4373 *
4374 * o destination transport address - specified as one of the destination
4375 * transport addresses of the peer endpoint to which this packet
4376 * should be sent. Whenever possible, SCTP should use this destination
4377 * transport address for sending the packets, instead of the current
4378 * primary path.
4379 *
4380 * o unorder flag - this flag, if present, indicates that the user
4381 * would like the data delivered in an unordered fashion to the peer
4382 * (i.e., the U flag is set to 1 on all DATA chunks carrying this
4383 * message).
4384 *
4385 * o no-bundle flag - instructs SCTP not to bundle this user data with
4386 * other outbound DATA chunks. SCTP MAY still bundle even when
4387 * this flag is present, when faced with network congestion.
4388 *
4389 * o payload protocol-id - A 32 bit unsigned integer that is to be
4390 * passed to the peer indicating the type of payload protocol data
4391 * being transmitted. This value is passed as opaque data by SCTP.
4392 *
4393 * The return value is the disposition.
4394 */
4395sctp_disposition_t sctp_sf_do_prm_send(const struct sctp_endpoint *ep,
4396 const struct sctp_association *asoc,
4397 const sctp_subtype_t type,
4398 void *arg,
4399 sctp_cmd_seq_t *commands)
4400{
4401 struct sctp_chunk *chunk = arg;
4402
4403 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
4404 return SCTP_DISPOSITION_CONSUME;
4405}
4406
4407/*
4408 * Process the SHUTDOWN primitive.
4409 *
4410 * Section: 10.1:
4411 * C) Shutdown
4412 *
4413 * Format: SHUTDOWN(association id)
4414 * -> result
4415 *
4416 * Gracefully closes an association. Any locally queued user data
4417 * will be delivered to the peer. The association will be terminated only
4418 * after the peer acknowledges all the SCTP packets sent. A success code
4419 * will be returned on successful termination of the association. If
4420 * attempting to terminate the association results in a failure, an error
4421 * code shall be returned.
4422 *
4423 * Mandatory attributes:
4424 *
4425 * o association id - local handle to the SCTP association
4426 *
4427 * Optional attributes:
4428 *
4429 * None.
4430 *
4431 * The return value is the disposition.
4432 */
4433sctp_disposition_t sctp_sf_do_9_2_prm_shutdown(
4434 const struct sctp_endpoint *ep,
4435 const struct sctp_association *asoc,
4436 const sctp_subtype_t type,
4437 void *arg,
4438 sctp_cmd_seq_t *commands)
4439{
4440 int disposition;
4441
4442 /* From 9.2 Shutdown of an Association
4443 * Upon receipt of the SHUTDOWN primitive from its upper
4444 * layer, the endpoint enters SHUTDOWN-PENDING state and
4445 * remains there until all outstanding data has been
4446 * acknowledged by its peer. The endpoint accepts no new data
4447 * from its upper layer, but retransmits data to the far end
4448 * if necessary to fill gaps.
4449 */
4450 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4451 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
4452
4453 /* sctpimpguide-05 Section 2.12.2
4454 * The sender of the SHUTDOWN MAY also start an overall guard timer
4455 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
4456 */
4457 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4458 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4459
4460 disposition = SCTP_DISPOSITION_CONSUME;
4461 if (sctp_outq_is_empty(&asoc->outqueue)) {
4462 disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type,
4463 arg, commands);
4464 }
4465 return disposition;
4466}
4467
4468/*
4469 * Process the ABORT primitive.
4470 *
4471 * Section: 10.1:
4472 * C) Abort
4473 *
4474 * Format: Abort(association id [, cause code])
4475 * -> result
4476 *
4477 * Ungracefully closes an association. Any locally queued user data
4478 * will be discarded and an ABORT chunk is sent to the peer. A success code
4479 * will be returned on successful abortion of the association. If
4480 * attempting to abort the association results in a failure, an error
4481 * code shall be returned.
4482 *
4483 * Mandatory attributes:
4484 *
4485 * o association id - local handle to the SCTP association
4486 *
4487 * Optional attributes:
4488 *
4489 * o cause code - reason of the abort to be passed to the peer
4490 *
4491 * None.
4492 *
4493 * The return value is the disposition.
4494 */
4495sctp_disposition_t sctp_sf_do_9_1_prm_abort(
4496 const struct sctp_endpoint *ep,
4497 const struct sctp_association *asoc,
4498 const sctp_subtype_t type,
4499 void *arg,
4500 sctp_cmd_seq_t *commands)
4501{
4502 /* From 9.1 Abort of an Association
4503 * Upon receipt of the ABORT primitive from its upper
4504 * layer, the endpoint enters CLOSED state and
4505 * discard all outstanding data has been
4506 * acknowledged by its peer. The endpoint accepts no new data
4507 * from its upper layer, but retransmits data to the far end
4508 * if necessary to fill gaps.
4509 */
Sridhar Samudralac164a9b2006-08-22 11:50:39 -07004510 struct sctp_chunk *abort = arg;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004511 sctp_disposition_t retval;
4512
4513 retval = SCTP_DISPOSITION_CONSUME;
4514
Sridhar Samudralac164a9b2006-08-22 11:50:39 -07004515 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004516
4517 /* Even if we can't send the ABORT due to low memory delete the
4518 * TCB. This is a departure from our typical NOMEM handling.
4519 */
4520
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004521 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4522 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004523 /* Delete the established association. */
4524 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08004525 SCTP_PERR(SCTP_ERROR_USER_ABORT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004526
4527 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4528 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
4529
4530 return retval;
4531}
4532
4533/* We tried an illegal operation on an association which is closed. */
4534sctp_disposition_t sctp_sf_error_closed(const struct sctp_endpoint *ep,
4535 const struct sctp_association *asoc,
4536 const sctp_subtype_t type,
4537 void *arg,
4538 sctp_cmd_seq_t *commands)
4539{
4540 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, SCTP_ERROR(-EINVAL));
4541 return SCTP_DISPOSITION_CONSUME;
4542}
4543
4544/* We tried an illegal operation on an association which is shutting
4545 * down.
4546 */
4547sctp_disposition_t sctp_sf_error_shutdown(const struct sctp_endpoint *ep,
4548 const struct sctp_association *asoc,
4549 const sctp_subtype_t type,
4550 void *arg,
4551 sctp_cmd_seq_t *commands)
4552{
4553 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR,
4554 SCTP_ERROR(-ESHUTDOWN));
4555 return SCTP_DISPOSITION_CONSUME;
4556}
4557
4558/*
4559 * sctp_cookie_wait_prm_shutdown
4560 *
4561 * Section: 4 Note: 2
4562 * Verification Tag:
4563 * Inputs
4564 * (endpoint, asoc)
4565 *
4566 * The RFC does not explicitly address this issue, but is the route through the
4567 * state table when someone issues a shutdown while in COOKIE_WAIT state.
4568 *
4569 * Outputs
4570 * (timers)
4571 */
4572sctp_disposition_t sctp_sf_cookie_wait_prm_shutdown(
4573 const struct sctp_endpoint *ep,
4574 const struct sctp_association *asoc,
4575 const sctp_subtype_t type,
4576 void *arg,
4577 sctp_cmd_seq_t *commands)
4578{
4579 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4580 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4581
4582 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4583 SCTP_STATE(SCTP_STATE_CLOSED));
4584
4585 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
4586
4587 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
4588
4589 return SCTP_DISPOSITION_DELETE_TCB;
4590}
4591
4592/*
4593 * sctp_cookie_echoed_prm_shutdown
4594 *
4595 * Section: 4 Note: 2
4596 * Verification Tag:
4597 * Inputs
4598 * (endpoint, asoc)
4599 *
4600 * The RFC does not explcitly address this issue, but is the route through the
4601 * state table when someone issues a shutdown while in COOKIE_ECHOED state.
4602 *
4603 * Outputs
4604 * (timers)
4605 */
4606sctp_disposition_t sctp_sf_cookie_echoed_prm_shutdown(
4607 const struct sctp_endpoint *ep,
4608 const struct sctp_association *asoc,
4609 const sctp_subtype_t type,
4610 void *arg, sctp_cmd_seq_t *commands)
4611{
4612 /* There is a single T1 timer, so we should be able to use
4613 * common function with the COOKIE-WAIT state.
4614 */
4615 return sctp_sf_cookie_wait_prm_shutdown(ep, asoc, type, arg, commands);
4616}
4617
4618/*
4619 * sctp_sf_cookie_wait_prm_abort
4620 *
4621 * Section: 4 Note: 2
4622 * Verification Tag:
4623 * Inputs
4624 * (endpoint, asoc)
4625 *
4626 * The RFC does not explicitly address this issue, but is the route through the
4627 * state table when someone issues an abort while in COOKIE_WAIT state.
4628 *
4629 * Outputs
4630 * (timers)
4631 */
4632sctp_disposition_t sctp_sf_cookie_wait_prm_abort(
4633 const struct sctp_endpoint *ep,
4634 const struct sctp_association *asoc,
4635 const sctp_subtype_t type,
4636 void *arg,
4637 sctp_cmd_seq_t *commands)
4638{
Sridhar Samudralac164a9b2006-08-22 11:50:39 -07004639 struct sctp_chunk *abort = arg;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004640 sctp_disposition_t retval;
4641
4642 /* Stop T1-init timer */
4643 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4644 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4645 retval = SCTP_DISPOSITION_CONSUME;
4646
Sridhar Samudralac164a9b2006-08-22 11:50:39 -07004647 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004648
4649 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4650 SCTP_STATE(SCTP_STATE_CLOSED));
4651
4652 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4653
4654 /* Even if we can't send the ABORT due to low memory delete the
4655 * TCB. This is a departure from our typical NOMEM handling.
4656 */
4657
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004658 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4659 SCTP_ERROR(ECONNREFUSED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004660 /* Delete the established association. */
4661 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08004662 SCTP_PERR(SCTP_ERROR_USER_ABORT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004663
4664 return retval;
4665}
4666
4667/*
4668 * sctp_sf_cookie_echoed_prm_abort
4669 *
4670 * Section: 4 Note: 3
4671 * Verification Tag:
4672 * Inputs
4673 * (endpoint, asoc)
4674 *
4675 * The RFC does not explcitly address this issue, but is the route through the
4676 * state table when someone issues an abort while in COOKIE_ECHOED state.
4677 *
4678 * Outputs
4679 * (timers)
4680 */
4681sctp_disposition_t sctp_sf_cookie_echoed_prm_abort(
4682 const struct sctp_endpoint *ep,
4683 const struct sctp_association *asoc,
4684 const sctp_subtype_t type,
4685 void *arg,
4686 sctp_cmd_seq_t *commands)
4687{
4688 /* There is a single T1 timer, so we should be able to use
4689 * common function with the COOKIE-WAIT state.
4690 */
4691 return sctp_sf_cookie_wait_prm_abort(ep, asoc, type, arg, commands);
4692}
4693
4694/*
4695 * sctp_sf_shutdown_pending_prm_abort
4696 *
4697 * Inputs
4698 * (endpoint, asoc)
4699 *
4700 * The RFC does not explicitly address this issue, but is the route through the
4701 * state table when someone issues an abort while in SHUTDOWN-PENDING state.
4702 *
4703 * Outputs
4704 * (timers)
4705 */
4706sctp_disposition_t sctp_sf_shutdown_pending_prm_abort(
4707 const struct sctp_endpoint *ep,
4708 const struct sctp_association *asoc,
4709 const sctp_subtype_t type,
4710 void *arg,
4711 sctp_cmd_seq_t *commands)
4712{
4713 /* Stop the T5-shutdown guard timer. */
4714 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4715 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4716
4717 return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands);
4718}
4719
4720/*
4721 * sctp_sf_shutdown_sent_prm_abort
4722 *
4723 * Inputs
4724 * (endpoint, asoc)
4725 *
4726 * The RFC does not explicitly address this issue, but is the route through the
4727 * state table when someone issues an abort while in SHUTDOWN-SENT state.
4728 *
4729 * Outputs
4730 * (timers)
4731 */
4732sctp_disposition_t sctp_sf_shutdown_sent_prm_abort(
4733 const struct sctp_endpoint *ep,
4734 const struct sctp_association *asoc,
4735 const sctp_subtype_t type,
4736 void *arg,
4737 sctp_cmd_seq_t *commands)
4738{
4739 /* Stop the T2-shutdown timer. */
4740 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4741 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4742
4743 /* Stop the T5-shutdown guard timer. */
4744 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4745 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4746
4747 return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands);
4748}
4749
4750/*
4751 * sctp_sf_cookie_echoed_prm_abort
4752 *
4753 * Inputs
4754 * (endpoint, asoc)
4755 *
4756 * The RFC does not explcitly address this issue, but is the route through the
4757 * state table when someone issues an abort while in COOKIE_ECHOED state.
4758 *
4759 * Outputs
4760 * (timers)
4761 */
4762sctp_disposition_t sctp_sf_shutdown_ack_sent_prm_abort(
4763 const struct sctp_endpoint *ep,
4764 const struct sctp_association *asoc,
4765 const sctp_subtype_t type,
4766 void *arg,
4767 sctp_cmd_seq_t *commands)
4768{
4769 /* The same T2 timer, so we should be able to use
4770 * common function with the SHUTDOWN-SENT state.
4771 */
4772 return sctp_sf_shutdown_sent_prm_abort(ep, asoc, type, arg, commands);
4773}
4774
4775/*
4776 * Process the REQUESTHEARTBEAT primitive
4777 *
4778 * 10.1 ULP-to-SCTP
4779 * J) Request Heartbeat
4780 *
4781 * Format: REQUESTHEARTBEAT(association id, destination transport address)
4782 *
4783 * -> result
4784 *
4785 * Instructs the local endpoint to perform a HeartBeat on the specified
4786 * destination transport address of the given association. The returned
4787 * result should indicate whether the transmission of the HEARTBEAT
4788 * chunk to the destination address is successful.
4789 *
4790 * Mandatory attributes:
4791 *
4792 * o association id - local handle to the SCTP association
4793 *
4794 * o destination transport address - the transport address of the
4795 * association on which a heartbeat should be issued.
4796 */
4797sctp_disposition_t sctp_sf_do_prm_requestheartbeat(
4798 const struct sctp_endpoint *ep,
4799 const struct sctp_association *asoc,
4800 const sctp_subtype_t type,
4801 void *arg,
4802 sctp_cmd_seq_t *commands)
4803{
Vlad Yasevichfb785252007-03-19 17:02:03 -07004804 if (SCTP_DISPOSITION_NOMEM == sctp_sf_heartbeat(ep, asoc, type,
4805 (struct sctp_transport *)arg, commands))
4806 return SCTP_DISPOSITION_NOMEM;
4807
4808 /*
4809 * RFC 2960 (bis), section 8.3
4810 *
4811 * D) Request an on-demand HEARTBEAT on a specific destination
4812 * transport address of a given association.
4813 *
4814 * The endpoint should increment the respective error counter of
4815 * the destination transport address each time a HEARTBEAT is sent
4816 * to that address and not acknowledged within one RTO.
4817 *
4818 */
4819 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_RESET,
4820 SCTP_TRANSPORT(arg));
4821 return SCTP_DISPOSITION_CONSUME;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004822}
4823
4824/*
4825 * ADDIP Section 4.1 ASCONF Chunk Procedures
4826 * When an endpoint has an ASCONF signaled change to be sent to the
4827 * remote endpoint it should do A1 to A9
4828 */
4829sctp_disposition_t sctp_sf_do_prm_asconf(const struct sctp_endpoint *ep,
4830 const struct sctp_association *asoc,
4831 const sctp_subtype_t type,
4832 void *arg,
4833 sctp_cmd_seq_t *commands)
4834{
4835 struct sctp_chunk *chunk = arg;
4836
4837 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
4838 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4839 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
4840 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
4841 return SCTP_DISPOSITION_CONSUME;
4842}
4843
4844/*
4845 * Ignore the primitive event
4846 *
4847 * The return value is the disposition of the primitive.
4848 */
4849sctp_disposition_t sctp_sf_ignore_primitive(
4850 const struct sctp_endpoint *ep,
4851 const struct sctp_association *asoc,
4852 const sctp_subtype_t type,
4853 void *arg,
4854 sctp_cmd_seq_t *commands)
4855{
4856 SCTP_DEBUG_PRINTK("Primitive type %d is ignored.\n", type.primitive);
4857 return SCTP_DISPOSITION_DISCARD;
4858}
4859
4860/***************************************************************************
4861 * These are the state functions for the OTHER events.
4862 ***************************************************************************/
4863
4864/*
4865 * Start the shutdown negotiation.
4866 *
4867 * From Section 9.2:
4868 * Once all its outstanding data has been acknowledged, the endpoint
4869 * shall send a SHUTDOWN chunk to its peer including in the Cumulative
4870 * TSN Ack field the last sequential TSN it has received from the peer.
4871 * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT
4872 * state. If the timer expires, the endpoint must re-send the SHUTDOWN
4873 * with the updated last sequential TSN received from its peer.
4874 *
4875 * The return value is the disposition.
4876 */
4877sctp_disposition_t sctp_sf_do_9_2_start_shutdown(
4878 const struct sctp_endpoint *ep,
4879 const struct sctp_association *asoc,
4880 const sctp_subtype_t type,
4881 void *arg,
4882 sctp_cmd_seq_t *commands)
4883{
4884 struct sctp_chunk *reply;
4885
4886 /* Once all its outstanding data has been acknowledged, the
4887 * endpoint shall send a SHUTDOWN chunk to its peer including
4888 * in the Cumulative TSN Ack field the last sequential TSN it
4889 * has received from the peer.
4890 */
4891 reply = sctp_make_shutdown(asoc, NULL);
4892 if (!reply)
4893 goto nomem;
4894
4895 /* Set the transport for the SHUTDOWN chunk and the timeout for the
4896 * T2-shutdown timer.
4897 */
4898 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
4899
4900 /* It shall then start the T2-shutdown timer */
4901 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4902 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4903
4904 if (asoc->autoclose)
4905 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4906 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
4907
4908 /* and enter the SHUTDOWN-SENT state. */
4909 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4910 SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT));
4911
4912 /* sctp-implguide 2.10 Issues with Heartbeating and failover
4913 *
4914 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09004915 * or SHUTDOWN-ACK.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004916 */
4917 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
4918
4919 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
4920
4921 return SCTP_DISPOSITION_CONSUME;
4922
4923nomem:
4924 return SCTP_DISPOSITION_NOMEM;
4925}
4926
4927/*
4928 * Generate a SHUTDOWN ACK now that everything is SACK'd.
4929 *
4930 * From Section 9.2:
4931 *
4932 * If it has no more outstanding DATA chunks, the SHUTDOWN receiver
4933 * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own,
4934 * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the
4935 * endpoint must re-send the SHUTDOWN ACK.
4936 *
4937 * The return value is the disposition.
4938 */
4939sctp_disposition_t sctp_sf_do_9_2_shutdown_ack(
4940 const struct sctp_endpoint *ep,
4941 const struct sctp_association *asoc,
4942 const sctp_subtype_t type,
4943 void *arg,
4944 sctp_cmd_seq_t *commands)
4945{
4946 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
4947 struct sctp_chunk *reply;
4948
4949 /* There are 2 ways of getting here:
4950 * 1) called in response to a SHUTDOWN chunk
4951 * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued.
4952 *
4953 * For the case (2), the arg parameter is set to NULL. We need
4954 * to check that we have a chunk before accessing it's fields.
4955 */
4956 if (chunk) {
4957 if (!sctp_vtag_verify(chunk, asoc))
4958 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
4959
4960 /* Make sure that the SHUTDOWN chunk has a valid length. */
4961 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_shutdown_chunk_t)))
4962 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
4963 commands);
4964 }
4965
4966 /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
4967 * shall send a SHUTDOWN ACK ...
4968 */
4969 reply = sctp_make_shutdown_ack(asoc, chunk);
4970 if (!reply)
4971 goto nomem;
4972
4973 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
4974 * the T2-shutdown timer.
4975 */
4976 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
4977
4978 /* and start/restart a T2-shutdown timer of its own, */
4979 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
4980 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4981
4982 if (asoc->autoclose)
4983 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4984 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
4985
4986 /* Enter the SHUTDOWN-ACK-SENT state. */
4987 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4988 SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT));
4989
4990 /* sctp-implguide 2.10 Issues with Heartbeating and failover
4991 *
4992 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09004993 * or SHUTDOWN-ACK.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004994 */
4995 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
4996
4997 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
4998
4999 return SCTP_DISPOSITION_CONSUME;
5000
5001nomem:
5002 return SCTP_DISPOSITION_NOMEM;
5003}
5004
5005/*
5006 * Ignore the event defined as other
5007 *
5008 * The return value is the disposition of the event.
5009 */
5010sctp_disposition_t sctp_sf_ignore_other(const struct sctp_endpoint *ep,
5011 const struct sctp_association *asoc,
5012 const sctp_subtype_t type,
5013 void *arg,
5014 sctp_cmd_seq_t *commands)
5015{
5016 SCTP_DEBUG_PRINTK("The event other type %d is ignored\n", type.other);
5017 return SCTP_DISPOSITION_DISCARD;
5018}
5019
5020/************************************************************
5021 * These are the state functions for handling timeout events.
5022 ************************************************************/
5023
5024/*
5025 * RTX Timeout
5026 *
5027 * Section: 6.3.3 Handle T3-rtx Expiration
5028 *
5029 * Whenever the retransmission timer T3-rtx expires for a destination
5030 * address, do the following:
5031 * [See below]
5032 *
5033 * The return value is the disposition of the chunk.
5034 */
5035sctp_disposition_t sctp_sf_do_6_3_3_rtx(const struct sctp_endpoint *ep,
5036 const struct sctp_association *asoc,
5037 const sctp_subtype_t type,
5038 void *arg,
5039 sctp_cmd_seq_t *commands)
5040{
5041 struct sctp_transport *transport = arg;
5042
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07005043 SCTP_INC_STATS(SCTP_MIB_T3_RTX_EXPIREDS);
5044
Linus Torvalds1da177e2005-04-16 15:20:36 -07005045 if (asoc->overall_error_count >= asoc->max_retrans) {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07005046 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5047 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005048 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5049 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08005050 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005051 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
5052 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
5053 return SCTP_DISPOSITION_DELETE_TCB;
5054 }
5055
5056 /* E1) For the destination address for which the timer
5057 * expires, adjust its ssthresh with rules defined in Section
5058 * 7.2.3 and set the cwnd <- MTU.
5059 */
5060
5061 /* E2) For the destination address for which the timer
5062 * expires, set RTO <- RTO * 2 ("back off the timer"). The
5063 * maximum value discussed in rule C7 above (RTO.max) may be
5064 * used to provide an upper bound to this doubling operation.
5065 */
5066
5067 /* E3) Determine how many of the earliest (i.e., lowest TSN)
5068 * outstanding DATA chunks for the address for which the
5069 * T3-rtx has expired will fit into a single packet, subject
5070 * to the MTU constraint for the path corresponding to the
5071 * destination transport address to which the retransmission
5072 * is being sent (this may be different from the address for
5073 * which the timer expires [see Section 6.4]). Call this
5074 * value K. Bundle and retransmit those K DATA chunks in a
5075 * single packet to the destination endpoint.
5076 *
5077 * Note: Any DATA chunks that were sent to the address for
5078 * which the T3-rtx timer expired but did not fit in one MTU
5079 * (rule E3 above), should be marked for retransmission and
5080 * sent as soon as cwnd allows (normally when a SACK arrives).
5081 */
5082
Linus Torvalds1da177e2005-04-16 15:20:36 -07005083 /* Do some failure management (Section 8.2). */
5084 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
5085
Vlad Yasevich1845a572007-02-21 02:06:19 -08005086 /* NB: Rules E4 and F1 are implicit in R1. */
5087 sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN, SCTP_TRANSPORT(transport));
5088
Linus Torvalds1da177e2005-04-16 15:20:36 -07005089 return SCTP_DISPOSITION_CONSUME;
5090}
5091
5092/*
5093 * Generate delayed SACK on timeout
5094 *
5095 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
5096 *
5097 * The guidelines on delayed acknowledgement algorithm specified in
5098 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
5099 * acknowledgement SHOULD be generated for at least every second packet
5100 * (not every second DATA chunk) received, and SHOULD be generated
5101 * within 200 ms of the arrival of any unacknowledged DATA chunk. In
5102 * some situations it may be beneficial for an SCTP transmitter to be
5103 * more conservative than the algorithms detailed in this document
5104 * allow. However, an SCTP transmitter MUST NOT be more aggressive than
5105 * the following algorithms allow.
5106 */
5107sctp_disposition_t sctp_sf_do_6_2_sack(const struct sctp_endpoint *ep,
5108 const struct sctp_association *asoc,
5109 const sctp_subtype_t type,
5110 void *arg,
5111 sctp_cmd_seq_t *commands)
5112{
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07005113 SCTP_INC_STATS(SCTP_MIB_DELAY_SACK_EXPIREDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005114 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
5115 return SCTP_DISPOSITION_CONSUME;
5116}
5117
5118/*
Frank Filz3f7a87d2005-06-20 13:14:57 -07005119 * sctp_sf_t1_init_timer_expire
Linus Torvalds1da177e2005-04-16 15:20:36 -07005120 *
5121 * Section: 4 Note: 2
5122 * Verification Tag:
5123 * Inputs
5124 * (endpoint, asoc)
5125 *
5126 * RFC 2960 Section 4 Notes
5127 * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT
5128 * and re-start the T1-init timer without changing state. This MUST
5129 * be repeated up to 'Max.Init.Retransmits' times. After that, the
5130 * endpoint MUST abort the initialization process and report the
5131 * error to SCTP user.
5132 *
Frank Filz3f7a87d2005-06-20 13:14:57 -07005133 * Outputs
5134 * (timers, events)
5135 *
5136 */
5137sctp_disposition_t sctp_sf_t1_init_timer_expire(const struct sctp_endpoint *ep,
5138 const struct sctp_association *asoc,
5139 const sctp_subtype_t type,
5140 void *arg,
5141 sctp_cmd_seq_t *commands)
5142{
5143 struct sctp_chunk *repl = NULL;
5144 struct sctp_bind_addr *bp;
5145 int attempts = asoc->init_err_counter + 1;
5146
5147 SCTP_DEBUG_PRINTK("Timer T1 expired (INIT).\n");
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07005148 SCTP_INC_STATS(SCTP_MIB_T1_INIT_EXPIREDS);
Frank Filz3f7a87d2005-06-20 13:14:57 -07005149
Vlad Yasevich81845c22006-01-30 15:59:54 -08005150 if (attempts <= asoc->max_init_attempts) {
Frank Filz3f7a87d2005-06-20 13:14:57 -07005151 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
5152 repl = sctp_make_init(asoc, bp, GFP_ATOMIC, 0);
5153 if (!repl)
5154 return SCTP_DISPOSITION_NOMEM;
5155
5156 /* Choose transport for INIT. */
5157 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
5158 SCTP_CHUNK(repl));
5159
5160 /* Issue a sideeffect to do the needed accounting. */
5161 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_RESTART,
5162 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
5163
5164 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
5165 } else {
5166 SCTP_DEBUG_PRINTK("Giving up on INIT, attempts: %d"
5167 " max_init_attempts: %d\n",
5168 attempts, asoc->max_init_attempts);
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07005169 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5170 SCTP_ERROR(ETIMEDOUT));
Frank Filz3f7a87d2005-06-20 13:14:57 -07005171 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08005172 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Frank Filz3f7a87d2005-06-20 13:14:57 -07005173 return SCTP_DISPOSITION_DELETE_TCB;
5174 }
5175
5176 return SCTP_DISPOSITION_CONSUME;
5177}
5178
5179/*
5180 * sctp_sf_t1_cookie_timer_expire
5181 *
5182 * Section: 4 Note: 2
5183 * Verification Tag:
5184 * Inputs
5185 * (endpoint, asoc)
5186 *
5187 * RFC 2960 Section 4 Notes
5188 * 3) If the T1-cookie timer expires, the endpoint MUST retransmit
Linus Torvalds1da177e2005-04-16 15:20:36 -07005189 * COOKIE ECHO and re-start the T1-cookie timer without changing
5190 * state. This MUST be repeated up to 'Max.Init.Retransmits' times.
5191 * After that, the endpoint MUST abort the initialization process and
5192 * report the error to SCTP user.
5193 *
5194 * Outputs
5195 * (timers, events)
5196 *
5197 */
Frank Filz3f7a87d2005-06-20 13:14:57 -07005198sctp_disposition_t sctp_sf_t1_cookie_timer_expire(const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005199 const struct sctp_association *asoc,
5200 const sctp_subtype_t type,
5201 void *arg,
5202 sctp_cmd_seq_t *commands)
5203{
Frank Filz3f7a87d2005-06-20 13:14:57 -07005204 struct sctp_chunk *repl = NULL;
5205 int attempts = asoc->init_err_counter + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005206
Frank Filz3f7a87d2005-06-20 13:14:57 -07005207 SCTP_DEBUG_PRINTK("Timer T1 expired (COOKIE-ECHO).\n");
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07005208 SCTP_INC_STATS(SCTP_MIB_T1_COOKIE_EXPIREDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005209
Vlad Yasevich81845c22006-01-30 15:59:54 -08005210 if (attempts <= asoc->max_init_attempts) {
Frank Filz3f7a87d2005-06-20 13:14:57 -07005211 repl = sctp_make_cookie_echo(asoc, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005212 if (!repl)
Frank Filz3f7a87d2005-06-20 13:14:57 -07005213 return SCTP_DISPOSITION_NOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005214
5215 /* Issue a sideeffect to do the needed accounting. */
Frank Filz3f7a87d2005-06-20 13:14:57 -07005216 sctp_add_cmd_sf(commands, SCTP_CMD_COOKIEECHO_RESTART,
5217 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
5218
Linus Torvalds1da177e2005-04-16 15:20:36 -07005219 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
5220 } else {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07005221 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5222 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005223 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08005224 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005225 return SCTP_DISPOSITION_DELETE_TCB;
5226 }
5227
5228 return SCTP_DISPOSITION_CONSUME;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005229}
5230
5231/* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN
5232 * with the updated last sequential TSN received from its peer.
5233 *
5234 * An endpoint should limit the number of retransmissions of the
5235 * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'.
5236 * If this threshold is exceeded the endpoint should destroy the TCB and
5237 * MUST report the peer endpoint unreachable to the upper layer (and
5238 * thus the association enters the CLOSED state). The reception of any
5239 * packet from its peer (i.e. as the peer sends all of its queued DATA
5240 * chunks) should clear the endpoint's retransmission count and restart
5241 * the T2-Shutdown timer, giving its peer ample opportunity to transmit
5242 * all of its queued DATA chunks that have not yet been sent.
5243 */
5244sctp_disposition_t sctp_sf_t2_timer_expire(const struct sctp_endpoint *ep,
5245 const struct sctp_association *asoc,
5246 const sctp_subtype_t type,
5247 void *arg,
5248 sctp_cmd_seq_t *commands)
5249{
5250 struct sctp_chunk *reply = NULL;
5251
5252 SCTP_DEBUG_PRINTK("Timer T2 expired.\n");
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07005253 SCTP_INC_STATS(SCTP_MIB_T2_SHUTDOWN_EXPIREDS);
5254
Linus Torvalds1da177e2005-04-16 15:20:36 -07005255 if (asoc->overall_error_count >= asoc->max_retrans) {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07005256 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5257 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005258 /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5259 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08005260 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005261 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
5262 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
5263 return SCTP_DISPOSITION_DELETE_TCB;
5264 }
5265
5266 switch (asoc->state) {
5267 case SCTP_STATE_SHUTDOWN_SENT:
5268 reply = sctp_make_shutdown(asoc, NULL);
5269 break;
5270
5271 case SCTP_STATE_SHUTDOWN_ACK_SENT:
5272 reply = sctp_make_shutdown_ack(asoc, NULL);
5273 break;
5274
5275 default:
5276 BUG();
5277 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07005278 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07005279
5280 if (!reply)
5281 goto nomem;
5282
5283 /* Do some failure management (Section 8.2). */
5284 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
5285 SCTP_TRANSPORT(asoc->shutdown_last_sent_to));
5286
5287 /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for
5288 * the T2-shutdown timer.
5289 */
5290 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5291
5292 /* Restart the T2-shutdown timer. */
5293 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5294 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5295 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5296 return SCTP_DISPOSITION_CONSUME;
5297
5298nomem:
5299 return SCTP_DISPOSITION_NOMEM;
5300}
5301
5302/*
5303 * ADDIP Section 4.1 ASCONF CHunk Procedures
5304 * If the T4 RTO timer expires the endpoint should do B1 to B5
5305 */
5306sctp_disposition_t sctp_sf_t4_timer_expire(
5307 const struct sctp_endpoint *ep,
5308 const struct sctp_association *asoc,
5309 const sctp_subtype_t type,
5310 void *arg,
5311 sctp_cmd_seq_t *commands)
5312{
5313 struct sctp_chunk *chunk = asoc->addip_last_asconf;
5314 struct sctp_transport *transport = chunk->transport;
5315
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07005316 SCTP_INC_STATS(SCTP_MIB_T4_RTO_EXPIREDS);
5317
Linus Torvalds1da177e2005-04-16 15:20:36 -07005318 /* ADDIP 4.1 B1) Increment the error counters and perform path failure
5319 * detection on the appropriate destination address as defined in
5320 * RFC2960 [5] section 8.1 and 8.2.
5321 */
5322 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
5323
5324 /* Reconfig T4 timer and transport. */
5325 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
5326
5327 /* ADDIP 4.1 B2) Increment the association error counters and perform
5328 * endpoint failure detection on the association as defined in
5329 * RFC2960 [5] section 8.1 and 8.2.
5330 * association error counter is incremented in SCTP_CMD_STRIKE.
5331 */
5332 if (asoc->overall_error_count >= asoc->max_retrans) {
5333 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5334 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07005335 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5336 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005337 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08005338 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005339 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
5340 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
5341 return SCTP_DISPOSITION_ABORT;
5342 }
5343
5344 /* ADDIP 4.1 B3) Back-off the destination address RTO value to which
5345 * the ASCONF chunk was sent by doubling the RTO timer value.
5346 * This is done in SCTP_CMD_STRIKE.
5347 */
5348
5349 /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible
5350 * choose an alternate destination address (please refer to RFC2960
5351 * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09005352 * chunk, it MUST be the same (including its serial number) as the last
Linus Torvalds1da177e2005-04-16 15:20:36 -07005353 * ASCONF sent.
5354 */
5355 sctp_chunk_hold(asoc->addip_last_asconf);
5356 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
5357 SCTP_CHUNK(asoc->addip_last_asconf));
5358
5359 /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different
5360 * destination is selected, then the RTO used will be that of the new
5361 * destination address.
5362 */
5363 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5364 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
5365
5366 return SCTP_DISPOSITION_CONSUME;
5367}
5368
5369/* sctpimpguide-05 Section 2.12.2
5370 * The sender of the SHUTDOWN MAY also start an overall guard timer
5371 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5372 * At the expiration of this timer the sender SHOULD abort the association
5373 * by sending an ABORT chunk.
5374 */
5375sctp_disposition_t sctp_sf_t5_timer_expire(const struct sctp_endpoint *ep,
5376 const struct sctp_association *asoc,
5377 const sctp_subtype_t type,
5378 void *arg,
5379 sctp_cmd_seq_t *commands)
5380{
5381 struct sctp_chunk *reply = NULL;
5382
5383 SCTP_DEBUG_PRINTK("Timer T5 expired.\n");
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07005384 SCTP_INC_STATS(SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005385
5386 reply = sctp_make_abort(asoc, NULL, 0);
5387 if (!reply)
5388 goto nomem;
5389
5390 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07005391 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5392 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005393 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08005394 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005395
5396 return SCTP_DISPOSITION_DELETE_TCB;
5397nomem:
5398 return SCTP_DISPOSITION_NOMEM;
5399}
5400
5401/* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires,
5402 * the association is automatically closed by starting the shutdown process.
5403 * The work that needs to be done is same as when SHUTDOWN is initiated by
5404 * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown().
5405 */
5406sctp_disposition_t sctp_sf_autoclose_timer_expire(
5407 const struct sctp_endpoint *ep,
5408 const struct sctp_association *asoc,
5409 const sctp_subtype_t type,
5410 void *arg,
5411 sctp_cmd_seq_t *commands)
5412{
5413 int disposition;
5414
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07005415 SCTP_INC_STATS(SCTP_MIB_AUTOCLOSE_EXPIREDS);
5416
Linus Torvalds1da177e2005-04-16 15:20:36 -07005417 /* From 9.2 Shutdown of an Association
5418 * Upon receipt of the SHUTDOWN primitive from its upper
5419 * layer, the endpoint enters SHUTDOWN-PENDING state and
5420 * remains there until all outstanding data has been
5421 * acknowledged by its peer. The endpoint accepts no new data
5422 * from its upper layer, but retransmits data to the far end
5423 * if necessary to fill gaps.
5424 */
5425 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5426 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
5427
5428 /* sctpimpguide-05 Section 2.12.2
5429 * The sender of the SHUTDOWN MAY also start an overall guard timer
5430 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09005431 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07005432 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
5433 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5434 disposition = SCTP_DISPOSITION_CONSUME;
5435 if (sctp_outq_is_empty(&asoc->outqueue)) {
5436 disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type,
5437 arg, commands);
5438 }
5439 return disposition;
5440}
5441
5442/*****************************************************************************
5443 * These are sa state functions which could apply to all types of events.
5444 ****************************************************************************/
5445
5446/*
5447 * This table entry is not implemented.
5448 *
5449 * Inputs
5450 * (endpoint, asoc, chunk)
5451 *
5452 * The return value is the disposition of the chunk.
5453 */
5454sctp_disposition_t sctp_sf_not_impl(const struct sctp_endpoint *ep,
5455 const struct sctp_association *asoc,
5456 const sctp_subtype_t type,
5457 void *arg,
5458 sctp_cmd_seq_t *commands)
5459{
5460 return SCTP_DISPOSITION_NOT_IMPL;
5461}
5462
5463/*
5464 * This table entry represents a bug.
5465 *
5466 * Inputs
5467 * (endpoint, asoc, chunk)
5468 *
5469 * The return value is the disposition of the chunk.
5470 */
5471sctp_disposition_t sctp_sf_bug(const struct sctp_endpoint *ep,
5472 const struct sctp_association *asoc,
5473 const sctp_subtype_t type,
5474 void *arg,
5475 sctp_cmd_seq_t *commands)
5476{
5477 return SCTP_DISPOSITION_BUG;
5478}
5479
5480/*
5481 * This table entry represents the firing of a timer in the wrong state.
5482 * Since timer deletion cannot be guaranteed a timer 'may' end up firing
5483 * when the association is in the wrong state. This event should
5484 * be ignored, so as to prevent any rearming of the timer.
5485 *
5486 * Inputs
5487 * (endpoint, asoc, chunk)
5488 *
5489 * The return value is the disposition of the chunk.
5490 */
5491sctp_disposition_t sctp_sf_timer_ignore(const struct sctp_endpoint *ep,
5492 const struct sctp_association *asoc,
5493 const sctp_subtype_t type,
5494 void *arg,
5495 sctp_cmd_seq_t *commands)
5496{
5497 SCTP_DEBUG_PRINTK("Timer %d ignored.\n", type.chunk);
5498 return SCTP_DISPOSITION_CONSUME;
5499}
5500
5501/********************************************************************
5502 * 2nd Level Abstractions
5503 ********************************************************************/
5504
5505/* Pull the SACK chunk based on the SACK header. */
5506static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk)
5507{
5508 struct sctp_sackhdr *sack;
5509 unsigned int len;
5510 __u16 num_blocks;
5511 __u16 num_dup_tsns;
5512
5513 /* Protect ourselves from reading too far into
5514 * the skb from a bogus sender.
5515 */
5516 sack = (struct sctp_sackhdr *) chunk->skb->data;
5517
5518 num_blocks = ntohs(sack->num_gap_ack_blocks);
5519 num_dup_tsns = ntohs(sack->num_dup_tsns);
5520 len = sizeof(struct sctp_sackhdr);
5521 len += (num_blocks + num_dup_tsns) * sizeof(__u32);
5522 if (len > chunk->skb->len)
5523 return NULL;
5524
5525 skb_pull(chunk->skb, len);
5526
5527 return sack;
5528}
5529
5530/* Create an ABORT packet to be sent as a response, with the specified
5531 * error causes.
5532 */
5533static struct sctp_packet *sctp_abort_pkt_new(const struct sctp_endpoint *ep,
5534 const struct sctp_association *asoc,
5535 struct sctp_chunk *chunk,
5536 const void *payload,
5537 size_t paylen)
5538{
5539 struct sctp_packet *packet;
5540 struct sctp_chunk *abort;
5541
5542 packet = sctp_ootb_pkt_new(asoc, chunk);
5543
5544 if (packet) {
5545 /* Make an ABORT.
5546 * The T bit will be set if the asoc is NULL.
5547 */
5548 abort = sctp_make_abort(asoc, chunk, paylen);
5549 if (!abort) {
5550 sctp_ootb_pkt_free(packet);
5551 return NULL;
5552 }
Jerome Forissier047a2422005-04-28 11:58:43 -07005553
5554 /* Reflect vtag if T-Bit is set */
5555 if (sctp_test_T_bit(abort))
5556 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
5557
Linus Torvalds1da177e2005-04-16 15:20:36 -07005558 /* Add specified error causes, i.e., payload, to the
5559 * end of the chunk.
5560 */
5561 sctp_addto_chunk(abort, paylen, payload);
5562
5563 /* Set the skb to the belonging sock for accounting. */
5564 abort->skb->sk = ep->base.sk;
5565
5566 sctp_packet_append_chunk(packet, abort);
5567
5568 }
5569
5570 return packet;
5571}
5572
5573/* Allocate a packet for responding in the OOTB conditions. */
5574static struct sctp_packet *sctp_ootb_pkt_new(const struct sctp_association *asoc,
5575 const struct sctp_chunk *chunk)
5576{
5577 struct sctp_packet *packet;
5578 struct sctp_transport *transport;
5579 __u16 sport;
5580 __u16 dport;
5581 __u32 vtag;
5582
5583 /* Get the source and destination port from the inbound packet. */
5584 sport = ntohs(chunk->sctp_hdr->dest);
5585 dport = ntohs(chunk->sctp_hdr->source);
5586
5587 /* The V-tag is going to be the same as the inbound packet if no
5588 * association exists, otherwise, use the peer's vtag.
5589 */
5590 if (asoc) {
Wei Yongjun02c4e122007-08-31 10:03:58 +08005591 /* Special case the INIT-ACK as there is no peer's vtag
5592 * yet.
5593 */
5594 switch(chunk->chunk_hdr->type) {
5595 case SCTP_CID_INIT_ACK:
5596 {
5597 sctp_initack_chunk_t *initack;
5598
5599 initack = (sctp_initack_chunk_t *)chunk->chunk_hdr;
5600 vtag = ntohl(initack->init_hdr.init_tag);
5601 break;
5602 }
5603 default:
5604 vtag = asoc->peer.i.init_tag;
5605 break;
5606 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07005607 } else {
5608 /* Special case the INIT and stale COOKIE_ECHO as there is no
5609 * vtag yet.
5610 */
5611 switch(chunk->chunk_hdr->type) {
5612 case SCTP_CID_INIT:
5613 {
5614 sctp_init_chunk_t *init;
5615
5616 init = (sctp_init_chunk_t *)chunk->chunk_hdr;
5617 vtag = ntohl(init->init_hdr.init_tag);
5618 break;
5619 }
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09005620 default:
Linus Torvalds1da177e2005-04-16 15:20:36 -07005621 vtag = ntohl(chunk->sctp_hdr->vtag);
5622 break;
5623 }
5624 }
5625
5626 /* Make a transport for the bucket, Eliza... */
Al Viro6a1e5f32006-11-20 17:12:25 -08005627 transport = sctp_transport_new(sctp_source(chunk), GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005628 if (!transport)
5629 goto nomem;
5630
5631 /* Cache a route for the transport with the chunk's destination as
5632 * the source address.
5633 */
Al Viro16b0a032006-11-20 17:13:38 -08005634 sctp_transport_route(transport, (union sctp_addr *)&chunk->dest,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005635 sctp_sk(sctp_get_ctl_sock()));
5636
5637 packet = sctp_packet_init(&transport->packet, transport, sport, dport);
5638 packet = sctp_packet_config(packet, vtag, 0);
5639
5640 return packet;
5641
5642nomem:
5643 return NULL;
5644}
5645
5646/* Free the packet allocated earlier for responding in the OOTB condition. */
5647void sctp_ootb_pkt_free(struct sctp_packet *packet)
5648{
5649 sctp_transport_free(packet->transport);
5650}
5651
5652/* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */
5653static void sctp_send_stale_cookie_err(const struct sctp_endpoint *ep,
5654 const struct sctp_association *asoc,
5655 const struct sctp_chunk *chunk,
5656 sctp_cmd_seq_t *commands,
5657 struct sctp_chunk *err_chunk)
5658{
5659 struct sctp_packet *packet;
5660
5661 if (err_chunk) {
5662 packet = sctp_ootb_pkt_new(asoc, chunk);
5663 if (packet) {
5664 struct sctp_signed_cookie *cookie;
5665
5666 /* Override the OOTB vtag from the cookie. */
5667 cookie = chunk->subh.cookie_hdr;
5668 packet->vtag = cookie->c.peer_vtag;
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09005669
Linus Torvalds1da177e2005-04-16 15:20:36 -07005670 /* Set the skb to the belonging sock for accounting. */
5671 err_chunk->skb->sk = ep->base.sk;
5672 sctp_packet_append_chunk(packet, err_chunk);
5673 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
5674 SCTP_PACKET(packet));
5675 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
5676 } else
5677 sctp_chunk_free (err_chunk);
5678 }
5679}
5680
5681
5682/* Process a data chunk */
5683static int sctp_eat_data(const struct sctp_association *asoc,
5684 struct sctp_chunk *chunk,
5685 sctp_cmd_seq_t *commands)
5686{
5687 sctp_datahdr_t *data_hdr;
5688 struct sctp_chunk *err;
5689 size_t datalen;
5690 sctp_verb_t deliver;
5691 int tmp;
5692 __u32 tsn;
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005693 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
Neil Horman049b3ff2005-11-11 16:08:24 -08005694 struct sock *sk = asoc->base.sk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005695
5696 data_hdr = chunk->subh.data_hdr = (sctp_datahdr_t *)chunk->skb->data;
5697 skb_pull(chunk->skb, sizeof(sctp_datahdr_t));
5698
5699 tsn = ntohl(data_hdr->tsn);
5700 SCTP_DEBUG_PRINTK("eat_data: TSN 0x%x.\n", tsn);
5701
5702 /* ASSERT: Now skb->data is really the user data. */
5703
Linus Torvalds1da177e2005-04-16 15:20:36 -07005704 /* Process ECN based congestion.
5705 *
5706 * Since the chunk structure is reused for all chunks within
5707 * a packet, we use ecn_ce_done to track if we've already
5708 * done CE processing for this packet.
5709 *
5710 * We need to do ECN processing even if we plan to discard the
5711 * chunk later.
5712 */
5713
5714 if (!chunk->ecn_ce_done) {
5715 struct sctp_af *af;
5716 chunk->ecn_ce_done = 1;
5717
5718 af = sctp_get_af_specific(
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07005719 ipver2af(ip_hdr(chunk->skb)->version));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005720
5721 if (af && af->is_ce(chunk->skb) && asoc->peer.ecn_capable) {
5722 /* Do real work as sideffect. */
5723 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_CE,
5724 SCTP_U32(tsn));
5725 }
5726 }
5727
5728 tmp = sctp_tsnmap_check(&asoc->peer.tsn_map, tsn);
5729 if (tmp < 0) {
5730 /* The TSN is too high--silently discard the chunk and
5731 * count on it getting retransmitted later.
5732 */
5733 return SCTP_IERROR_HIGH_TSN;
5734 } else if (tmp > 0) {
5735 /* This is a duplicate. Record it. */
5736 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_DUP, SCTP_U32(tsn));
5737 return SCTP_IERROR_DUP_TSN;
5738 }
5739
5740 /* This is a new TSN. */
5741
5742 /* Discard if there is no room in the receive window.
5743 * Actually, allow a little bit of overflow (up to a MTU).
5744 */
5745 datalen = ntohs(chunk->chunk_hdr->length);
5746 datalen -= sizeof(sctp_data_chunk_t);
5747
5748 deliver = SCTP_CMD_CHUNK_ULP;
5749
5750 /* Think about partial delivery. */
5751 if ((datalen >= asoc->rwnd) && (!asoc->ulpq.pd_mode)) {
5752
5753 /* Even if we don't accept this chunk there is
5754 * memory pressure.
5755 */
5756 sctp_add_cmd_sf(commands, SCTP_CMD_PART_DELIVER, SCTP_NULL());
5757 }
5758
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09005759 /* Spill over rwnd a little bit. Note: While allowed, this spill over
Linus Torvalds1da177e2005-04-16 15:20:36 -07005760 * seems a bit troublesome in that frag_point varies based on
5761 * PMTU. In cases, such as loopback, this might be a rather
5762 * large spill over.
5763 */
Neil Horman4d93df02007-08-15 16:07:44 -07005764 if ((!chunk->data_accepted) && (!asoc->rwnd || asoc->rwnd_over ||
5765 (datalen > asoc->rwnd + asoc->frag_point))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07005766
5767 /* If this is the next TSN, consider reneging to make
5768 * room. Note: Playing nice with a confused sender. A
5769 * malicious sender can still eat up all our buffer
5770 * space and in the future we may want to detect and
5771 * do more drastic reneging.
5772 */
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005773 if (sctp_tsnmap_has_gap(map) &&
5774 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07005775 SCTP_DEBUG_PRINTK("Reneging for tsn:%u\n", tsn);
5776 deliver = SCTP_CMD_RENEGE;
5777 } else {
5778 SCTP_DEBUG_PRINTK("Discard tsn: %u len: %Zd, "
5779 "rwnd: %d\n", tsn, datalen,
5780 asoc->rwnd);
5781 return SCTP_IERROR_IGNORE_TSN;
5782 }
5783 }
5784
5785 /*
Neil Horman4d93df02007-08-15 16:07:44 -07005786 * Also try to renege to limit our memory usage in the event that
5787 * we are under memory pressure
5788 * If we can't renege, don't worry about it, the sk_stream_rmem_schedule
5789 * in sctp_ulpevent_make_rcvmsg will drop the frame if we grow our
5790 * memory usage too much
5791 */
5792 if (*sk->sk_prot_creator->memory_pressure) {
5793 if (sctp_tsnmap_has_gap(map) &&
5794 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
5795 SCTP_DEBUG_PRINTK("Under Pressure! Reneging for tsn:%u\n", tsn);
5796 deliver = SCTP_CMD_RENEGE;
5797 }
5798 }
5799
5800 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -07005801 * Section 3.3.10.9 No User Data (9)
5802 *
5803 * Cause of error
5804 * ---------------
5805 * No User Data: This error cause is returned to the originator of a
5806 * DATA chunk if a received DATA chunk has no user data.
5807 */
5808 if (unlikely(0 == datalen)) {
5809 err = sctp_make_abort_no_data(asoc, chunk, tsn);
5810 if (err) {
5811 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
5812 SCTP_CHUNK(err));
5813 }
5814 /* We are going to ABORT, so we might as well stop
5815 * processing the rest of the chunks in the packet.
5816 */
5817 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07005818 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5819 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005820 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08005821 SCTP_PERR(SCTP_ERROR_NO_DATA));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005822 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
5823 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
5824 return SCTP_IERROR_NO_DATA;
5825 }
5826
5827 /* If definately accepting the DATA chunk, record its TSN, otherwise
5828 * wait for renege processing.
5829 */
5830 if (SCTP_CMD_CHUNK_ULP == deliver)
5831 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_TSN, SCTP_U32(tsn));
5832
Sridhar Samudrala9faa7302006-07-21 14:49:07 -07005833 chunk->data_accepted = 1;
5834
Linus Torvalds1da177e2005-04-16 15:20:36 -07005835 /* Note: Some chunks may get overcounted (if we drop) or overcounted
5836 * if we renege and the chunk arrives again.
5837 */
5838 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
5839 SCTP_INC_STATS(SCTP_MIB_INUNORDERCHUNKS);
5840 else
5841 SCTP_INC_STATS(SCTP_MIB_INORDERCHUNKS);
5842
5843 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
5844 *
5845 * If an endpoint receive a DATA chunk with an invalid stream
5846 * identifier, it shall acknowledge the reception of the DATA chunk
5847 * following the normal procedure, immediately send an ERROR chunk
5848 * with cause set to "Invalid Stream Identifier" (See Section 3.3.10)
5849 * and discard the DATA chunk.
5850 */
5851 if (ntohs(data_hdr->stream) >= asoc->c.sinit_max_instreams) {
5852 err = sctp_make_op_error(asoc, chunk, SCTP_ERROR_INV_STRM,
5853 &data_hdr->stream,
5854 sizeof(data_hdr->stream));
5855 if (err)
5856 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
5857 SCTP_CHUNK(err));
5858 return SCTP_IERROR_BAD_STREAM;
5859 }
5860
5861 /* Send the data up to the user. Note: Schedule the
5862 * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK
5863 * chunk needs the updated rwnd.
5864 */
5865 sctp_add_cmd_sf(commands, deliver, SCTP_CHUNK(chunk));
5866
5867 return SCTP_IERROR_NO_ERROR;
5868}