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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);
93static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk);
94
Adrian Bunk52c1da32005-06-23 22:05:33 -070095static sctp_disposition_t sctp_stop_t1_and_abort(sctp_cmd_seq_t *commands,
Al Virof94c0192006-11-20 17:00:25 -080096 __be16 error, int sk_err,
Adrian Bunk52c1da32005-06-23 22:05:33 -070097 const struct sctp_association *asoc,
98 struct sctp_transport *transport);
99
100static sctp_disposition_t sctp_sf_violation_chunklen(
101 const struct sctp_endpoint *ep,
102 const struct sctp_association *asoc,
103 const sctp_subtype_t type,
104 void *arg,
105 sctp_cmd_seq_t *commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106
107/* Small helper function that checks if the chunk length
108 * is of the appropriate length. The 'required_length' argument
109 * is set to be the size of a specific chunk we are testing.
110 * Return Values: 1 = Valid length
111 * 0 = Invalid length
112 *
113 */
114static inline int
115sctp_chunk_length_valid(struct sctp_chunk *chunk,
116 __u16 required_length)
117{
118 __u16 chunk_length = ntohs(chunk->chunk_hdr->length);
119
120 if (unlikely(chunk_length < required_length))
121 return 0;
122
123 return 1;
124}
125
126/**********************************************************
127 * These are the state functions for handling chunk events.
128 **********************************************************/
129
130/*
131 * Process the final SHUTDOWN COMPLETE.
132 *
133 * Section: 4 (C) (diagram), 9.2
134 * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify
135 * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be
136 * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint
137 * should stop the T2-shutdown timer and remove all knowledge of the
138 * association (and thus the association enters the CLOSED state).
139 *
Jerome Forissier047a2422005-04-28 11:58:43 -0700140 * Verification Tag: 8.5.1(C), sctpimpguide 2.41.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141 * C) Rules for packet carrying SHUTDOWN COMPLETE:
142 * ...
Jerome Forissier047a2422005-04-28 11:58:43 -0700143 * - The receiver of a SHUTDOWN COMPLETE shall accept the packet
144 * if the Verification Tag field of the packet matches its own tag and
145 * the T bit is not set
146 * OR
147 * it is set to its peer's tag and the T bit is set in the Chunk
148 * Flags.
149 * Otherwise, the receiver MUST silently discard the packet
150 * and take no further action. An endpoint MUST ignore the
151 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152 *
153 * Inputs
154 * (endpoint, asoc, chunk)
155 *
156 * Outputs
157 * (asoc, reply_msg, msg_up, timers, counters)
158 *
159 * The return value is the disposition of the chunk.
160 */
161sctp_disposition_t sctp_sf_do_4_C(const struct sctp_endpoint *ep,
162 const struct sctp_association *asoc,
163 const sctp_subtype_t type,
164 void *arg,
165 sctp_cmd_seq_t *commands)
166{
167 struct sctp_chunk *chunk = arg;
168 struct sctp_ulpevent *ev;
169
170 /* RFC 2960 6.10 Bundling
171 *
172 * An endpoint MUST NOT bundle INIT, INIT ACK or
173 * SHUTDOWN COMPLETE with any other chunks.
174 */
175 if (!chunk->singleton)
176 return SCTP_DISPOSITION_VIOLATION;
177
178 if (!sctp_vtag_verify_either(chunk, asoc))
179 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
180
181 /* RFC 2960 10.2 SCTP-to-ULP
182 *
183 * H) SHUTDOWN COMPLETE notification
184 *
185 * When SCTP completes the shutdown procedures (section 9.2) this
186 * notification is passed to the upper layer.
187 */
188 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
Vlad Yasevicha5a35e72007-03-23 11:34:08 -0700189 0, 0, 0, NULL, GFP_ATOMIC);
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700190 if (ev)
191 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900192 SCTP_ULPEVENT(ev));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193
194 /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint
195 * will verify that it is in SHUTDOWN-ACK-SENT state, if it is
196 * not the chunk should be discarded. If the endpoint is in
197 * the SHUTDOWN-ACK-SENT state the endpoint should stop the
198 * T2-shutdown timer and remove all knowledge of the
199 * association (and thus the association enters the CLOSED
200 * state).
201 */
202 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
203 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
204
205 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
206 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
207
208 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
209 SCTP_STATE(SCTP_STATE_CLOSED));
210
211 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
212 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
213
214 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
215
216 return SCTP_DISPOSITION_DELETE_TCB;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217}
218
219/*
220 * Respond to a normal INIT chunk.
221 * We are the side that is being asked for an association.
222 *
223 * Section: 5.1 Normal Establishment of an Association, B
224 * B) "Z" shall respond immediately with an INIT ACK chunk. The
225 * destination IP address of the INIT ACK MUST be set to the source
226 * IP address of the INIT to which this INIT ACK is responding. In
227 * the response, besides filling in other parameters, "Z" must set the
228 * Verification Tag field to Tag_A, and also provide its own
229 * Verification Tag (Tag_Z) in the Initiate Tag field.
230 *
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900231 * Verification Tag: Must be 0.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232 *
233 * Inputs
234 * (endpoint, asoc, chunk)
235 *
236 * Outputs
237 * (asoc, reply_msg, msg_up, timers, counters)
238 *
239 * The return value is the disposition of the chunk.
240 */
241sctp_disposition_t sctp_sf_do_5_1B_init(const struct sctp_endpoint *ep,
242 const struct sctp_association *asoc,
243 const sctp_subtype_t type,
244 void *arg,
245 sctp_cmd_seq_t *commands)
246{
247 struct sctp_chunk *chunk = arg;
248 struct sctp_chunk *repl;
249 struct sctp_association *new_asoc;
250 struct sctp_chunk *err_chunk;
251 struct sctp_packet *packet;
252 sctp_unrecognized_param_t *unk_param;
253 struct sock *sk;
254 int len;
255
256 /* 6.10 Bundling
257 * An endpoint MUST NOT bundle INIT, INIT ACK or
258 * SHUTDOWN COMPLETE with any other chunks.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900259 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260 * IG Section 2.11.2
261 * Furthermore, we require that the receiver of an INIT chunk MUST
262 * enforce these rules by silently discarding an arriving packet
263 * with an INIT chunk that is bundled with other chunks.
264 */
265 if (!chunk->singleton)
266 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
267
268 /* If the packet is an OOTB packet which is temporarily on the
269 * control endpoint, respond with an ABORT.
270 */
271 if (ep == sctp_sk((sctp_get_ctl_sock()))->ep)
272 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
273
274 sk = ep->base.sk;
275 /* If the endpoint is not listening or if the number of associations
276 * on the TCP-style socket exceed the max backlog, respond with an
277 * ABORT.
278 */
279 if (!sctp_sstate(sk, LISTENING) ||
280 (sctp_style(sk, TCP) &&
281 sk_acceptq_is_full(sk)))
282 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
283
284 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900285 * Tag.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286 */
287 if (chunk->sctp_hdr->vtag != 0)
288 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
289
290 /* Make sure that the INIT chunk has a valid length.
291 * Normally, this would cause an ABORT with a Protocol Violation
292 * error, but since we don't have an association, we'll
293 * just discard the packet.
294 */
295 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
296 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
297
298 /* Verify the INIT chunk before processing it. */
299 err_chunk = NULL;
300 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
301 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
302 &err_chunk)) {
303 /* This chunk contains fatal error. It is to be discarded.
304 * Send an ABORT, with causes if there is any.
305 */
306 if (err_chunk) {
307 packet = sctp_abort_pkt_new(ep, asoc, arg,
308 (__u8 *)(err_chunk->chunk_hdr) +
309 sizeof(sctp_chunkhdr_t),
310 ntohs(err_chunk->chunk_hdr->length) -
311 sizeof(sctp_chunkhdr_t));
312
313 sctp_chunk_free(err_chunk);
314
315 if (packet) {
316 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
317 SCTP_PACKET(packet));
318 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
319 return SCTP_DISPOSITION_CONSUME;
320 } else {
321 return SCTP_DISPOSITION_NOMEM;
322 }
323 } else {
324 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg,
325 commands);
326 }
327 }
328
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900329 /* Grab the INIT header. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330 chunk->subh.init_hdr = (sctp_inithdr_t *)chunk->skb->data;
331
332 /* Tag the variable length parameters. */
333 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
334
335 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
336 if (!new_asoc)
337 goto nomem;
338
339 /* The call, sctp_process_init(), can fail on memory allocation. */
340 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
341 sctp_source(chunk),
342 (sctp_init_chunk_t *)chunk->chunk_hdr,
343 GFP_ATOMIC))
344 goto nomem_init;
345
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
347
348 /* If there are errors need to be reported for unknown parameters,
349 * make sure to reserve enough room in the INIT ACK for them.
350 */
351 len = 0;
352 if (err_chunk)
353 len = ntohs(err_chunk->chunk_hdr->length) -
354 sizeof(sctp_chunkhdr_t);
355
356 if (sctp_assoc_set_bind_addr_from_ep(new_asoc, GFP_ATOMIC) < 0)
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700357 goto nomem_init;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700358
359 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
360 if (!repl)
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700361 goto nomem_init;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362
363 /* If there are errors need to be reported for unknown parameters,
364 * include them in the outgoing INIT ACK as "Unrecognized parameter"
365 * parameter.
366 */
367 if (err_chunk) {
368 /* Get the "Unrecognized parameter" parameter(s) out of the
369 * ERROR chunk generated by sctp_verify_init(). Since the
370 * error cause code for "unknown parameter" and the
371 * "Unrecognized parameter" type is the same, we can
372 * construct the parameters in INIT ACK by copying the
373 * ERROR causes over.
374 */
375 unk_param = (sctp_unrecognized_param_t *)
376 ((__u8 *)(err_chunk->chunk_hdr) +
377 sizeof(sctp_chunkhdr_t));
378 /* Replace the cause code with the "Unrecognized parameter"
379 * parameter type.
380 */
381 sctp_addto_chunk(repl, len, unk_param);
382 sctp_chunk_free(err_chunk);
383 }
384
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700385 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
386
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
388
389 /*
390 * Note: After sending out INIT ACK with the State Cookie parameter,
391 * "Z" MUST NOT allocate any resources, nor keep any states for the
392 * new association. Otherwise, "Z" will be vulnerable to resource
393 * attacks.
394 */
395 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
396
397 return SCTP_DISPOSITION_DELETE_TCB;
398
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399nomem_init:
400 sctp_association_free(new_asoc);
401nomem:
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700402 if (err_chunk)
403 sctp_chunk_free(err_chunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404 return SCTP_DISPOSITION_NOMEM;
405}
406
407/*
408 * Respond to a normal INIT ACK chunk.
409 * We are the side that is initiating the association.
410 *
411 * Section: 5.1 Normal Establishment of an Association, C
412 * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init
413 * timer and leave COOKIE-WAIT state. "A" shall then send the State
414 * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start
415 * the T1-cookie timer, and enter the COOKIE-ECHOED state.
416 *
417 * Note: The COOKIE ECHO chunk can be bundled with any pending outbound
418 * DATA chunks, but it MUST be the first chunk in the packet and
419 * until the COOKIE ACK is returned the sender MUST NOT send any
420 * other packets to the peer.
421 *
422 * Verification Tag: 3.3.3
423 * If the value of the Initiate Tag in a received INIT ACK chunk is
424 * found to be 0, the receiver MUST treat it as an error and close the
425 * association by transmitting an ABORT.
426 *
427 * Inputs
428 * (endpoint, asoc, chunk)
429 *
430 * Outputs
431 * (asoc, reply_msg, msg_up, timers, counters)
432 *
433 * The return value is the disposition of the chunk.
434 */
435sctp_disposition_t sctp_sf_do_5_1C_ack(const struct sctp_endpoint *ep,
436 const struct sctp_association *asoc,
437 const sctp_subtype_t type,
438 void *arg,
439 sctp_cmd_seq_t *commands)
440{
441 struct sctp_chunk *chunk = arg;
442 sctp_init_chunk_t *initchunk;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443 struct sctp_chunk *err_chunk;
444 struct sctp_packet *packet;
Al Virof94c0192006-11-20 17:00:25 -0800445 sctp_error_t error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446
447 if (!sctp_vtag_verify(chunk, asoc))
448 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
449
450 /* Make sure that the INIT-ACK chunk has a valid length */
451 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_initack_chunk_t)))
452 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
453 commands);
454 /* 6.10 Bundling
455 * An endpoint MUST NOT bundle INIT, INIT ACK or
456 * SHUTDOWN COMPLETE with any other chunks.
457 */
458 if (!chunk->singleton)
459 return SCTP_DISPOSITION_VIOLATION;
460
461 /* Grab the INIT header. */
462 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
463
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464 /* Verify the INIT chunk before processing it. */
465 err_chunk = NULL;
466 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
467 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
468 &err_chunk)) {
469
470 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
471
472 /* This chunk contains fatal error. It is to be discarded.
473 * Send an ABORT, with causes if there is any.
474 */
475 if (err_chunk) {
476 packet = sctp_abort_pkt_new(ep, asoc, arg,
477 (__u8 *)(err_chunk->chunk_hdr) +
478 sizeof(sctp_chunkhdr_t),
479 ntohs(err_chunk->chunk_hdr->length) -
480 sizeof(sctp_chunkhdr_t));
481
482 sctp_chunk_free(err_chunk);
483
484 if (packet) {
485 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
486 SCTP_PACKET(packet));
487 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700488 error = SCTP_ERROR_INV_PARAM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489 } else {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700490 error = SCTP_ERROR_NO_RESOURCE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491 }
492 } else {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700493 sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
494 error = SCTP_ERROR_INV_PARAM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700495 }
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700496 return sctp_stop_t1_and_abort(commands, error, ECONNREFUSED,
497 asoc, chunk->transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498 }
499
500 /* Tag the variable length parameters. Note that we never
501 * convert the parameters in an INIT chunk.
502 */
503 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
504
505 initchunk = (sctp_init_chunk_t *) chunk->chunk_hdr;
506
507 sctp_add_cmd_sf(commands, SCTP_CMD_PEER_INIT,
508 SCTP_PEER_INIT(initchunk));
509
Frank Filz3f7a87d2005-06-20 13:14:57 -0700510 /* Reset init error count upon receipt of INIT-ACK. */
511 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
512
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513 /* 5.1 C) "A" shall stop the T1-init timer and leave
514 * COOKIE-WAIT state. "A" shall then ... start the T1-cookie
515 * timer, and enter the COOKIE-ECHOED state.
516 */
517 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
518 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
519 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
520 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
521 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
522 SCTP_STATE(SCTP_STATE_COOKIE_ECHOED));
523
524 /* 5.1 C) "A" shall then send the State Cookie received in the
525 * INIT ACK chunk in a COOKIE ECHO chunk, ...
526 */
527 /* If there is any errors to report, send the ERROR chunk generated
528 * for unknown parameters as well.
529 */
530 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_COOKIE_ECHO,
531 SCTP_CHUNK(err_chunk));
532
533 return SCTP_DISPOSITION_CONSUME;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700534}
535
536/*
537 * Respond to a normal COOKIE ECHO chunk.
538 * We are the side that is being asked for an association.
539 *
540 * Section: 5.1 Normal Establishment of an Association, D
541 * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply
542 * with a COOKIE ACK chunk after building a TCB and moving to
543 * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with
544 * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK
545 * chunk MUST be the first chunk in the packet.
546 *
547 * IMPLEMENTATION NOTE: An implementation may choose to send the
548 * Communication Up notification to the SCTP user upon reception
549 * of a valid COOKIE ECHO chunk.
550 *
551 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
552 * D) Rules for packet carrying a COOKIE ECHO
553 *
554 * - When sending a COOKIE ECHO, the endpoint MUST use the value of the
555 * Initial Tag received in the INIT ACK.
556 *
557 * - The receiver of a COOKIE ECHO follows the procedures in Section 5.
558 *
559 * Inputs
560 * (endpoint, asoc, chunk)
561 *
562 * Outputs
563 * (asoc, reply_msg, msg_up, timers, counters)
564 *
565 * The return value is the disposition of the chunk.
566 */
567sctp_disposition_t sctp_sf_do_5_1D_ce(const struct sctp_endpoint *ep,
568 const struct sctp_association *asoc,
569 const sctp_subtype_t type, void *arg,
570 sctp_cmd_seq_t *commands)
571{
572 struct sctp_chunk *chunk = arg;
573 struct sctp_association *new_asoc;
574 sctp_init_chunk_t *peer_init;
575 struct sctp_chunk *repl;
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700576 struct sctp_ulpevent *ev, *ai_ev = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577 int error = 0;
578 struct sctp_chunk *err_chk_p;
579
580 /* If the packet is an OOTB packet which is temporarily on the
581 * control endpoint, respond with an ABORT.
582 */
583 if (ep == sctp_sk((sctp_get_ctl_sock()))->ep)
584 return sctp_sf_ootb(ep, asoc, type, arg, commands);
585
586 /* Make sure that the COOKIE_ECHO chunk has a valid length.
587 * In this case, we check that we have enough for at least a
588 * chunk header. More detailed verification is done
589 * in sctp_unpack_cookie().
590 */
591 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
592 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
593
594 /* "Decode" the chunk. We have no optional parameters so we
595 * are in good shape.
596 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900597 chunk->subh.cookie_hdr =
Linus Torvalds1da177e2005-04-16 15:20:36 -0700598 (struct sctp_signed_cookie *)chunk->skb->data;
Sridhar Samudrala62b08082006-05-05 17:04:43 -0700599 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
600 sizeof(sctp_chunkhdr_t)))
601 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602
603 /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
604 * "Z" will reply with a COOKIE ACK chunk after building a TCB
605 * and moving to the ESTABLISHED state.
606 */
607 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
608 &err_chk_p);
609
610 /* FIXME:
611 * If the re-build failed, what is the proper error path
612 * from here?
613 *
614 * [We should abort the association. --piggy]
615 */
616 if (!new_asoc) {
617 /* FIXME: Several errors are possible. A bad cookie should
618 * be silently discarded, but think about logging it too.
619 */
620 switch (error) {
621 case -SCTP_IERROR_NOMEM:
622 goto nomem;
623
624 case -SCTP_IERROR_STALE_COOKIE:
625 sctp_send_stale_cookie_err(ep, asoc, chunk, commands,
626 err_chk_p);
627 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
628
629 case -SCTP_IERROR_BAD_SIG:
630 default:
631 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700632 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633 }
634
Linus Torvalds1da177e2005-04-16 15:20:36 -0700635
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700636 /* Delay state machine commands until later.
637 *
638 * Re-build the bind address for the association is done in
Linus Torvalds1da177e2005-04-16 15:20:36 -0700639 * the sctp_unpack_cookie() already.
640 */
641 /* This is a brand-new association, so these are not yet side
642 * effects--it is safe to run them here.
643 */
644 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
645
646 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
Al Viro6a1e5f32006-11-20 17:12:25 -0800647 &chunk->subh.cookie_hdr->c.peer_addr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648 peer_init, GFP_ATOMIC))
649 goto nomem_init;
650
651 repl = sctp_make_cookie_ack(new_asoc, chunk);
652 if (!repl)
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700653 goto nomem_init;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654
655 /* RFC 2960 5.1 Normal Establishment of an Association
656 *
657 * D) IMPLEMENTATION NOTE: An implementation may choose to
658 * send the Communication Up notification to the SCTP user
659 * upon reception of a valid COOKIE ECHO chunk.
660 */
661 ev = sctp_ulpevent_make_assoc_change(new_asoc, 0, SCTP_COMM_UP, 0,
662 new_asoc->c.sinit_num_ostreams,
663 new_asoc->c.sinit_max_instreams,
Vlad Yasevicha5a35e72007-03-23 11:34:08 -0700664 NULL, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665 if (!ev)
666 goto nomem_ev;
667
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900668 /* Sockets API Draft Section 5.3.1.6
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -0800669 * When a peer sends a Adaptation Layer Indication parameter , SCTP
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670 * delivers this notification to inform the application that of the
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -0800671 * peers requested adaptation layer.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672 */
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -0800673 if (new_asoc->peer.adaptation_ind) {
674 ai_ev = sctp_ulpevent_make_adaptation_indication(new_asoc,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675 GFP_ATOMIC);
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700676 if (!ai_ev)
677 goto nomem_aiev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678 }
679
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700680 /* Add all the state machine commands now since we've created
681 * everything. This way we don't introduce memory corruptions
682 * during side-effect processing and correclty count established
683 * associations.
684 */
685 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
686 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
687 SCTP_STATE(SCTP_STATE_ESTABLISHED));
688 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
689 SCTP_INC_STATS(SCTP_MIB_PASSIVEESTABS);
690 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
691
692 if (new_asoc->autoclose)
693 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
694 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
695
696 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
697
698 /* This will send the COOKIE ACK */
699 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
700
701 /* Queue the ASSOC_CHANGE event */
702 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
703
704 /* Send up the Adaptation Layer Indication event */
705 if (ai_ev)
706 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
707 SCTP_ULPEVENT(ai_ev));
708
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709 return SCTP_DISPOSITION_CONSUME;
710
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700711nomem_aiev:
712 sctp_ulpevent_free(ev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713nomem_ev:
714 sctp_chunk_free(repl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715nomem_init:
716 sctp_association_free(new_asoc);
717nomem:
718 return SCTP_DISPOSITION_NOMEM;
719}
720
721/*
722 * Respond to a normal COOKIE ACK chunk.
723 * We are the side that is being asked for an association.
724 *
725 * RFC 2960 5.1 Normal Establishment of an Association
726 *
727 * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the
728 * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie
729 * timer. It may also notify its ULP about the successful
730 * establishment of the association with a Communication Up
731 * notification (see Section 10).
732 *
733 * Verification Tag:
734 * Inputs
735 * (endpoint, asoc, chunk)
736 *
737 * Outputs
738 * (asoc, reply_msg, msg_up, timers, counters)
739 *
740 * The return value is the disposition of the chunk.
741 */
742sctp_disposition_t sctp_sf_do_5_1E_ca(const struct sctp_endpoint *ep,
743 const struct sctp_association *asoc,
744 const sctp_subtype_t type, void *arg,
745 sctp_cmd_seq_t *commands)
746{
747 struct sctp_chunk *chunk = arg;
748 struct sctp_ulpevent *ev;
749
750 if (!sctp_vtag_verify(chunk, asoc))
751 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
752
753 /* Verify that the chunk length for the COOKIE-ACK is OK.
754 * If we don't do this, any bundled chunks may be junked.
755 */
756 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
757 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
758 commands);
759
760 /* Reset init error count upon receipt of COOKIE-ACK,
761 * to avoid problems with the managemement of this
762 * counter in stale cookie situations when a transition back
763 * from the COOKIE-ECHOED state to the COOKIE-WAIT
764 * state is performed.
765 */
Frank Filz3f7a87d2005-06-20 13:14:57 -0700766 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
Linus Torvalds1da177e2005-04-16 15:20:36 -0700767
768 /* RFC 2960 5.1 Normal Establishment of an Association
769 *
770 * E) Upon reception of the COOKIE ACK, endpoint "A" will move
771 * from the COOKIE-ECHOED state to the ESTABLISHED state,
772 * stopping the T1-cookie timer.
773 */
774 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
775 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
776 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
777 SCTP_STATE(SCTP_STATE_ESTABLISHED));
778 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
779 SCTP_INC_STATS(SCTP_MIB_ACTIVEESTABS);
780 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
781 if (asoc->autoclose)
782 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
783 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
784 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
785
786 /* It may also notify its ULP about the successful
787 * establishment of the association with a Communication Up
788 * notification (see Section 10).
789 */
790 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP,
791 0, asoc->c.sinit_num_ostreams,
792 asoc->c.sinit_max_instreams,
Vlad Yasevicha5a35e72007-03-23 11:34:08 -0700793 NULL, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700794
795 if (!ev)
796 goto nomem;
797
798 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
799
800 /* Sockets API Draft Section 5.3.1.6
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -0800801 * When a peer sends a Adaptation Layer Indication parameter , SCTP
Linus Torvalds1da177e2005-04-16 15:20:36 -0700802 * delivers this notification to inform the application that of the
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -0800803 * peers requested adaptation layer.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700804 */
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -0800805 if (asoc->peer.adaptation_ind) {
806 ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700807 if (!ev)
808 goto nomem;
809
810 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
811 SCTP_ULPEVENT(ev));
812 }
813
814 return SCTP_DISPOSITION_CONSUME;
815nomem:
816 return SCTP_DISPOSITION_NOMEM;
817}
818
819/* Generate and sendout a heartbeat packet. */
820static sctp_disposition_t sctp_sf_heartbeat(const struct sctp_endpoint *ep,
821 const struct sctp_association *asoc,
822 const sctp_subtype_t type,
823 void *arg,
824 sctp_cmd_seq_t *commands)
825{
826 struct sctp_transport *transport = (struct sctp_transport *) arg;
827 struct sctp_chunk *reply;
828 sctp_sender_hb_info_t hbinfo;
829 size_t paylen = 0;
830
831 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO;
832 hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t));
Al Viro63de08f2006-11-20 17:07:25 -0800833 hbinfo.daddr = transport->ipaddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700834 hbinfo.sent_at = jiffies;
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700835 hbinfo.hb_nonce = transport->hb_nonce;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700836
837 /* Send a heartbeat to our peer. */
838 paylen = sizeof(sctp_sender_hb_info_t);
839 reply = sctp_make_heartbeat(asoc, transport, &hbinfo, paylen);
840 if (!reply)
841 return SCTP_DISPOSITION_NOMEM;
842
843 /* Set rto_pending indicating that an RTT measurement
844 * is started with this heartbeat chunk.
845 */
846 sctp_add_cmd_sf(commands, SCTP_CMD_RTO_PENDING,
847 SCTP_TRANSPORT(transport));
848
849 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
850 return SCTP_DISPOSITION_CONSUME;
851}
852
853/* Generate a HEARTBEAT packet on the given transport. */
854sctp_disposition_t sctp_sf_sendbeat_8_3(const struct sctp_endpoint *ep,
855 const struct sctp_association *asoc,
856 const sctp_subtype_t type,
857 void *arg,
858 sctp_cmd_seq_t *commands)
859{
860 struct sctp_transport *transport = (struct sctp_transport *) arg;
861
Vlad Yaseviche2c2fc22006-01-30 16:00:40 -0800862 if (asoc->overall_error_count >= asoc->max_retrans) {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700863 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
864 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700865 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
866 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -0800867 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700868 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
869 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
870 return SCTP_DISPOSITION_DELETE_TCB;
871 }
872
873 /* Section 3.3.5.
874 * The Sender-specific Heartbeat Info field should normally include
875 * information about the sender's current time when this HEARTBEAT
876 * chunk is sent and the destination transport address to which this
877 * HEARTBEAT is sent (see Section 8.3).
878 */
879
Frank Filz52ccb8e2005-12-22 11:36:46 -0800880 if (transport->param_flags & SPP_HB_ENABLE) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700881 if (SCTP_DISPOSITION_NOMEM ==
882 sctp_sf_heartbeat(ep, asoc, type, arg,
883 commands))
884 return SCTP_DISPOSITION_NOMEM;
885 /* Set transport error counter and association error counter
886 * when sending heartbeat.
887 */
888 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_RESET,
889 SCTP_TRANSPORT(transport));
890 }
891 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMER_UPDATE,
892 SCTP_TRANSPORT(transport));
893
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900894 return SCTP_DISPOSITION_CONSUME;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700895}
896
897/*
898 * Process an heartbeat request.
899 *
900 * Section: 8.3 Path Heartbeat
901 * The receiver of the HEARTBEAT should immediately respond with a
902 * HEARTBEAT ACK that contains the Heartbeat Information field copied
903 * from the received HEARTBEAT chunk.
904 *
905 * Verification Tag: 8.5 Verification Tag [Normal verification]
906 * When receiving an SCTP packet, the endpoint MUST ensure that the
907 * value in the Verification Tag field of the received SCTP packet
908 * matches its own Tag. If the received Verification Tag value does not
909 * match the receiver's own tag value, the receiver shall silently
910 * discard the packet and shall not process it any further except for
911 * those cases listed in Section 8.5.1 below.
912 *
913 * Inputs
914 * (endpoint, asoc, chunk)
915 *
916 * Outputs
917 * (asoc, reply_msg, msg_up, timers, counters)
918 *
919 * The return value is the disposition of the chunk.
920 */
921sctp_disposition_t sctp_sf_beat_8_3(const struct sctp_endpoint *ep,
922 const struct sctp_association *asoc,
923 const sctp_subtype_t type,
924 void *arg,
925 sctp_cmd_seq_t *commands)
926{
927 struct sctp_chunk *chunk = arg;
928 struct sctp_chunk *reply;
929 size_t paylen = 0;
930
931 if (!sctp_vtag_verify(chunk, asoc))
932 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
933
934 /* Make sure that the HEARTBEAT chunk has a valid length. */
935 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t)))
936 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
937 commands);
938
939 /* 8.3 The receiver of the HEARTBEAT should immediately
940 * respond with a HEARTBEAT ACK that contains the Heartbeat
941 * Information field copied from the received HEARTBEAT chunk.
942 */
943 chunk->subh.hb_hdr = (sctp_heartbeathdr_t *) chunk->skb->data;
944 paylen = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
Sridhar Samudrala62b08082006-05-05 17:04:43 -0700945 if (!pskb_pull(chunk->skb, paylen))
946 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700947
948 reply = sctp_make_heartbeat_ack(asoc, chunk,
949 chunk->subh.hb_hdr, paylen);
950 if (!reply)
951 goto nomem;
952
953 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
954 return SCTP_DISPOSITION_CONSUME;
955
956nomem:
957 return SCTP_DISPOSITION_NOMEM;
958}
959
960/*
961 * Process the returning HEARTBEAT ACK.
962 *
963 * Section: 8.3 Path Heartbeat
964 * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT
965 * should clear the error counter of the destination transport
966 * address to which the HEARTBEAT was sent, and mark the destination
967 * transport address as active if it is not so marked. The endpoint may
968 * optionally report to the upper layer when an inactive destination
969 * address is marked as active due to the reception of the latest
970 * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also
971 * clear the association overall error count as well (as defined
972 * in section 8.1).
973 *
974 * The receiver of the HEARTBEAT ACK should also perform an RTT
975 * measurement for that destination transport address using the time
976 * value carried in the HEARTBEAT ACK chunk.
977 *
978 * Verification Tag: 8.5 Verification Tag [Normal verification]
979 *
980 * Inputs
981 * (endpoint, asoc, chunk)
982 *
983 * Outputs
984 * (asoc, reply_msg, msg_up, timers, counters)
985 *
986 * The return value is the disposition of the chunk.
987 */
988sctp_disposition_t sctp_sf_backbeat_8_3(const struct sctp_endpoint *ep,
989 const struct sctp_association *asoc,
990 const sctp_subtype_t type,
991 void *arg,
992 sctp_cmd_seq_t *commands)
993{
994 struct sctp_chunk *chunk = arg;
995 union sctp_addr from_addr;
996 struct sctp_transport *link;
997 sctp_sender_hb_info_t *hbinfo;
998 unsigned long max_interval;
999
1000 if (!sctp_vtag_verify(chunk, asoc))
1001 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1002
1003 /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */
1004 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t)))
1005 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1006 commands);
1007
1008 hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
Vladislav Yasevicha6012662006-05-19 14:25:53 -07001009 /* Make sure that the length of the parameter is what we expect */
1010 if (ntohs(hbinfo->param_hdr.length) !=
1011 sizeof(sctp_sender_hb_info_t)) {
1012 return SCTP_DISPOSITION_DISCARD;
1013 }
1014
Linus Torvalds1da177e2005-04-16 15:20:36 -07001015 from_addr = hbinfo->daddr;
Al Viro63de08f2006-11-20 17:07:25 -08001016 link = sctp_assoc_lookup_paddr(asoc, &from_addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001017
1018 /* This should never happen, but lets log it if so. */
Frank Filz3f7a87d2005-06-20 13:14:57 -07001019 if (unlikely(!link)) {
1020 if (from_addr.sa.sa_family == AF_INET6) {
1021 printk(KERN_WARNING
1022 "%s association %p could not find address "
Joe Perches46b86a22006-01-13 14:29:07 -08001023 NIP6_FMT "\n",
Frank Filz3f7a87d2005-06-20 13:14:57 -07001024 __FUNCTION__,
1025 asoc,
1026 NIP6(from_addr.v6.sin6_addr));
1027 } else {
1028 printk(KERN_WARNING
1029 "%s association %p could not find address "
Joe Perches46b86a22006-01-13 14:29:07 -08001030 NIPQUAD_FMT "\n",
Frank Filz3f7a87d2005-06-20 13:14:57 -07001031 __FUNCTION__,
1032 asoc,
1033 NIPQUAD(from_addr.v4.sin_addr.s_addr));
1034 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001035 return SCTP_DISPOSITION_DISCARD;
1036 }
1037
Sridhar Samudralaad8fec12006-07-21 14:48:50 -07001038 /* Validate the 64-bit random nonce. */
1039 if (hbinfo->hb_nonce != link->hb_nonce)
1040 return SCTP_DISPOSITION_DISCARD;
1041
Frank Filz52ccb8e2005-12-22 11:36:46 -08001042 max_interval = link->hbinterval + link->rto;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001043
1044 /* Check if the timestamp looks valid. */
1045 if (time_after(hbinfo->sent_at, jiffies) ||
1046 time_after(jiffies, hbinfo->sent_at + max_interval)) {
1047 SCTP_DEBUG_PRINTK("%s: HEARTBEAT ACK with invalid timestamp"
1048 "received for transport: %p\n",
1049 __FUNCTION__, link);
1050 return SCTP_DISPOSITION_DISCARD;
1051 }
1052
1053 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of
1054 * the HEARTBEAT should clear the error counter of the
1055 * destination transport address to which the HEARTBEAT was
1056 * sent and mark the destination transport address as active if
1057 * it is not so marked.
1058 */
1059 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_ON, SCTP_TRANSPORT(link));
1060
1061 return SCTP_DISPOSITION_CONSUME;
1062}
1063
1064/* Helper function to send out an abort for the restart
1065 * condition.
1066 */
1067static int sctp_sf_send_restart_abort(union sctp_addr *ssa,
1068 struct sctp_chunk *init,
1069 sctp_cmd_seq_t *commands)
1070{
1071 int len;
1072 struct sctp_packet *pkt;
1073 union sctp_addr_param *addrparm;
1074 struct sctp_errhdr *errhdr;
1075 struct sctp_endpoint *ep;
1076 char buffer[sizeof(struct sctp_errhdr)+sizeof(union sctp_addr_param)];
1077 struct sctp_af *af = sctp_get_af_specific(ssa->v4.sin_family);
1078
1079 /* Build the error on the stack. We are way to malloc crazy
1080 * throughout the code today.
1081 */
1082 errhdr = (struct sctp_errhdr *)buffer;
1083 addrparm = (union sctp_addr_param *)errhdr->variable;
1084
1085 /* Copy into a parm format. */
1086 len = af->to_addr_param(ssa, addrparm);
1087 len += sizeof(sctp_errhdr_t);
1088
1089 errhdr->cause = SCTP_ERROR_RESTART;
1090 errhdr->length = htons(len);
1091
1092 /* Assign to the control socket. */
1093 ep = sctp_sk((sctp_get_ctl_sock()))->ep;
1094
1095 /* Association is NULL since this may be a restart attack and we
1096 * want to send back the attacker's vtag.
1097 */
1098 pkt = sctp_abort_pkt_new(ep, NULL, init, errhdr, len);
1099
1100 if (!pkt)
1101 goto out;
1102 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, SCTP_PACKET(pkt));
1103
1104 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
1105
1106 /* Discard the rest of the inbound packet. */
1107 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
1108
1109out:
1110 /* Even if there is no memory, treat as a failure so
1111 * the packet will get dropped.
1112 */
1113 return 0;
1114}
1115
1116/* A restart is occurring, check to make sure no new addresses
1117 * are being added as we may be under a takeover attack.
1118 */
1119static int sctp_sf_check_restart_addrs(const struct sctp_association *new_asoc,
1120 const struct sctp_association *asoc,
1121 struct sctp_chunk *init,
1122 sctp_cmd_seq_t *commands)
1123{
1124 struct sctp_transport *new_addr, *addr;
1125 struct list_head *pos, *pos2;
1126 int found;
1127
1128 /* Implementor's Guide - Sectin 5.2.2
1129 * ...
1130 * Before responding the endpoint MUST check to see if the
1131 * unexpected INIT adds new addresses to the association. If new
1132 * addresses are added to the association, the endpoint MUST respond
1133 * with an ABORT..
1134 */
1135
1136 /* Search through all current addresses and make sure
1137 * we aren't adding any new ones.
1138 */
1139 new_addr = NULL;
1140 found = 0;
1141
1142 list_for_each(pos, &new_asoc->peer.transport_addr_list) {
1143 new_addr = list_entry(pos, struct sctp_transport, transports);
1144 found = 0;
1145 list_for_each(pos2, &asoc->peer.transport_addr_list) {
1146 addr = list_entry(pos2, struct sctp_transport,
1147 transports);
Al Viro5f242a12006-11-20 17:05:23 -08001148 if (sctp_cmp_addr_exact(&new_addr->ipaddr,
1149 &addr->ipaddr)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001150 found = 1;
1151 break;
1152 }
1153 }
1154 if (!found)
1155 break;
1156 }
1157
1158 /* If a new address was added, ABORT the sender. */
1159 if (!found && new_addr) {
Al Viro7dd8a582006-11-20 17:23:25 -08001160 sctp_sf_send_restart_abort(&new_addr->ipaddr, init, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001161 }
1162
1163 /* Return success if all addresses were found. */
1164 return found;
1165}
1166
1167/* Populate the verification/tie tags based on overlapping INIT
1168 * scenario.
1169 *
1170 * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state.
1171 */
1172static void sctp_tietags_populate(struct sctp_association *new_asoc,
1173 const struct sctp_association *asoc)
1174{
1175 switch (asoc->state) {
1176
1177 /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */
1178
1179 case SCTP_STATE_COOKIE_WAIT:
1180 new_asoc->c.my_vtag = asoc->c.my_vtag;
1181 new_asoc->c.my_ttag = asoc->c.my_vtag;
1182 new_asoc->c.peer_ttag = 0;
1183 break;
1184
1185 case SCTP_STATE_COOKIE_ECHOED:
1186 new_asoc->c.my_vtag = asoc->c.my_vtag;
1187 new_asoc->c.my_ttag = asoc->c.my_vtag;
1188 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1189 break;
1190
1191 /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED,
1192 * COOKIE-WAIT and SHUTDOWN-ACK-SENT
1193 */
1194 default:
1195 new_asoc->c.my_ttag = asoc->c.my_vtag;
1196 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1197 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07001198 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001199
1200 /* Other parameters for the endpoint SHOULD be copied from the
1201 * existing parameters of the association (e.g. number of
1202 * outbound streams) into the INIT ACK and cookie.
1203 */
1204 new_asoc->rwnd = asoc->rwnd;
1205 new_asoc->c.sinit_num_ostreams = asoc->c.sinit_num_ostreams;
1206 new_asoc->c.sinit_max_instreams = asoc->c.sinit_max_instreams;
1207 new_asoc->c.initial_tsn = asoc->c.initial_tsn;
1208}
1209
1210/*
1211 * Compare vtag/tietag values to determine unexpected COOKIE-ECHO
1212 * handling action.
1213 *
1214 * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists.
1215 *
1216 * Returns value representing action to be taken. These action values
1217 * correspond to Action/Description values in RFC 2960, Table 2.
1218 */
1219static char sctp_tietags_compare(struct sctp_association *new_asoc,
1220 const struct sctp_association *asoc)
1221{
1222 /* In this case, the peer may have restarted. */
1223 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1224 (asoc->c.peer_vtag != new_asoc->c.peer_vtag) &&
1225 (asoc->c.my_vtag == new_asoc->c.my_ttag) &&
1226 (asoc->c.peer_vtag == new_asoc->c.peer_ttag))
1227 return 'A';
1228
1229 /* Collision case B. */
1230 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1231 ((asoc->c.peer_vtag != new_asoc->c.peer_vtag) ||
1232 (0 == asoc->c.peer_vtag))) {
1233 return 'B';
1234 }
1235
1236 /* Collision case D. */
1237 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1238 (asoc->c.peer_vtag == new_asoc->c.peer_vtag))
1239 return 'D';
1240
1241 /* Collision case C. */
1242 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1243 (asoc->c.peer_vtag == new_asoc->c.peer_vtag) &&
1244 (0 == new_asoc->c.my_ttag) &&
1245 (0 == new_asoc->c.peer_ttag))
1246 return 'C';
1247
1248 /* No match to any of the special cases; discard this packet. */
1249 return 'E';
1250}
1251
1252/* Common helper routine for both duplicate and simulataneous INIT
1253 * chunk handling.
1254 */
1255static sctp_disposition_t sctp_sf_do_unexpected_init(
1256 const struct sctp_endpoint *ep,
1257 const struct sctp_association *asoc,
1258 const sctp_subtype_t type,
1259 void *arg, sctp_cmd_seq_t *commands)
1260{
1261 sctp_disposition_t retval;
1262 struct sctp_chunk *chunk = arg;
1263 struct sctp_chunk *repl;
1264 struct sctp_association *new_asoc;
1265 struct sctp_chunk *err_chunk;
1266 struct sctp_packet *packet;
1267 sctp_unrecognized_param_t *unk_param;
1268 int len;
1269
1270 /* 6.10 Bundling
1271 * An endpoint MUST NOT bundle INIT, INIT ACK or
1272 * SHUTDOWN COMPLETE with any other chunks.
1273 *
1274 * IG Section 2.11.2
1275 * Furthermore, we require that the receiver of an INIT chunk MUST
1276 * enforce these rules by silently discarding an arriving packet
1277 * with an INIT chunk that is bundled with other chunks.
1278 */
1279 if (!chunk->singleton)
1280 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1281
1282 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001283 * Tag.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001284 */
1285 if (chunk->sctp_hdr->vtag != 0)
1286 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
1287
1288 /* Make sure that the INIT chunk has a valid length.
1289 * In this case, we generate a protocol violation since we have
1290 * an association established.
1291 */
1292 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
1293 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1294 commands);
1295 /* Grab the INIT header. */
1296 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
1297
1298 /* Tag the variable length parameters. */
1299 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
1300
1301 /* Verify the INIT chunk before processing it. */
1302 err_chunk = NULL;
1303 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
1304 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
1305 &err_chunk)) {
1306 /* This chunk contains fatal error. It is to be discarded.
1307 * Send an ABORT, with causes if there is any.
1308 */
1309 if (err_chunk) {
1310 packet = sctp_abort_pkt_new(ep, asoc, arg,
1311 (__u8 *)(err_chunk->chunk_hdr) +
1312 sizeof(sctp_chunkhdr_t),
1313 ntohs(err_chunk->chunk_hdr->length) -
1314 sizeof(sctp_chunkhdr_t));
1315
1316 if (packet) {
1317 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
1318 SCTP_PACKET(packet));
1319 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
1320 retval = SCTP_DISPOSITION_CONSUME;
1321 } else {
1322 retval = SCTP_DISPOSITION_NOMEM;
1323 }
1324 goto cleanup;
1325 } else {
1326 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg,
1327 commands);
1328 }
1329 }
1330
1331 /*
1332 * Other parameters for the endpoint SHOULD be copied from the
1333 * existing parameters of the association (e.g. number of
1334 * outbound streams) into the INIT ACK and cookie.
1335 * FIXME: We are copying parameters from the endpoint not the
1336 * association.
1337 */
1338 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
1339 if (!new_asoc)
1340 goto nomem;
1341
1342 /* In the outbound INIT ACK the endpoint MUST copy its current
1343 * Verification Tag and Peers Verification tag into a reserved
1344 * place (local tie-tag and per tie-tag) within the state cookie.
1345 */
1346 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
1347 sctp_source(chunk),
1348 (sctp_init_chunk_t *)chunk->chunk_hdr,
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001349 GFP_ATOMIC))
1350 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001351
1352 /* Make sure no new addresses are being added during the
1353 * restart. Do not do this check for COOKIE-WAIT state,
1354 * since there are no peer addresses to check against.
1355 * Upon return an ABORT will have been sent if needed.
1356 */
1357 if (!sctp_state(asoc, COOKIE_WAIT)) {
1358 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk,
1359 commands)) {
1360 retval = SCTP_DISPOSITION_CONSUME;
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001361 goto nomem_retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001362 }
1363 }
1364
1365 sctp_tietags_populate(new_asoc, asoc);
1366
1367 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
1368
1369 /* If there are errors need to be reported for unknown parameters,
1370 * make sure to reserve enough room in the INIT ACK for them.
1371 */
1372 len = 0;
1373 if (err_chunk) {
1374 len = ntohs(err_chunk->chunk_hdr->length) -
1375 sizeof(sctp_chunkhdr_t);
1376 }
1377
1378 if (sctp_assoc_set_bind_addr_from_ep(new_asoc, GFP_ATOMIC) < 0)
1379 goto nomem;
1380
1381 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
1382 if (!repl)
1383 goto nomem;
1384
1385 /* If there are errors need to be reported for unknown parameters,
1386 * include them in the outgoing INIT ACK as "Unrecognized parameter"
1387 * parameter.
1388 */
1389 if (err_chunk) {
1390 /* Get the "Unrecognized parameter" parameter(s) out of the
1391 * ERROR chunk generated by sctp_verify_init(). Since the
1392 * error cause code for "unknown parameter" and the
1393 * "Unrecognized parameter" type is the same, we can
1394 * construct the parameters in INIT ACK by copying the
1395 * ERROR causes over.
1396 */
1397 unk_param = (sctp_unrecognized_param_t *)
1398 ((__u8 *)(err_chunk->chunk_hdr) +
1399 sizeof(sctp_chunkhdr_t));
1400 /* Replace the cause code with the "Unrecognized parameter"
1401 * parameter type.
1402 */
1403 sctp_addto_chunk(repl, len, unk_param);
1404 }
1405
1406 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
1407 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1408
1409 /*
1410 * Note: After sending out INIT ACK with the State Cookie parameter,
1411 * "Z" MUST NOT allocate any resources for this new association.
1412 * Otherwise, "Z" will be vulnerable to resource attacks.
1413 */
1414 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
1415 retval = SCTP_DISPOSITION_CONSUME;
1416
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001417 return retval;
1418
1419nomem:
1420 retval = SCTP_DISPOSITION_NOMEM;
1421nomem_retval:
1422 if (new_asoc)
1423 sctp_association_free(new_asoc);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001424cleanup:
1425 if (err_chunk)
1426 sctp_chunk_free(err_chunk);
1427 return retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001428}
1429
1430/*
1431 * Handle simultanous INIT.
1432 * This means we started an INIT and then we got an INIT request from
1433 * our peer.
1434 *
1435 * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B)
1436 * This usually indicates an initialization collision, i.e., each
1437 * endpoint is attempting, at about the same time, to establish an
1438 * association with the other endpoint.
1439 *
1440 * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an
1441 * endpoint MUST respond with an INIT ACK using the same parameters it
1442 * sent in its original INIT chunk (including its Verification Tag,
1443 * unchanged). These original parameters are combined with those from the
1444 * newly received INIT chunk. The endpoint shall also generate a State
1445 * Cookie with the INIT ACK. The endpoint uses the parameters sent in its
1446 * INIT to calculate the State Cookie.
1447 *
1448 * After that, the endpoint MUST NOT change its state, the T1-init
1449 * timer shall be left running and the corresponding TCB MUST NOT be
1450 * destroyed. The normal procedures for handling State Cookies when
1451 * a TCB exists will resolve the duplicate INITs to a single association.
1452 *
1453 * For an endpoint that is in the COOKIE-ECHOED state it MUST populate
1454 * its Tie-Tags with the Tag information of itself and its peer (see
1455 * section 5.2.2 for a description of the Tie-Tags).
1456 *
1457 * Verification Tag: Not explicit, but an INIT can not have a valid
1458 * verification tag, so we skip the check.
1459 *
1460 * Inputs
1461 * (endpoint, asoc, chunk)
1462 *
1463 * Outputs
1464 * (asoc, reply_msg, msg_up, timers, counters)
1465 *
1466 * The return value is the disposition of the chunk.
1467 */
1468sctp_disposition_t sctp_sf_do_5_2_1_siminit(const struct sctp_endpoint *ep,
1469 const struct sctp_association *asoc,
1470 const sctp_subtype_t type,
1471 void *arg,
1472 sctp_cmd_seq_t *commands)
1473{
1474 /* Call helper to do the real work for both simulataneous and
1475 * duplicate INIT chunk handling.
1476 */
1477 return sctp_sf_do_unexpected_init(ep, asoc, type, arg, commands);
1478}
1479
1480/*
1481 * Handle duplicated INIT messages. These are usually delayed
1482 * restransmissions.
1483 *
1484 * Section: 5.2.2 Unexpected INIT in States Other than CLOSED,
1485 * COOKIE-ECHOED and COOKIE-WAIT
1486 *
1487 * Unless otherwise stated, upon reception of an unexpected INIT for
1488 * this association, the endpoint shall generate an INIT ACK with a
1489 * State Cookie. In the outbound INIT ACK the endpoint MUST copy its
1490 * current Verification Tag and peer's Verification Tag into a reserved
1491 * place within the state cookie. We shall refer to these locations as
1492 * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet
1493 * containing this INIT ACK MUST carry a Verification Tag value equal to
1494 * the Initiation Tag found in the unexpected INIT. And the INIT ACK
1495 * MUST contain a new Initiation Tag (randomly generated see Section
1496 * 5.3.1). Other parameters for the endpoint SHOULD be copied from the
1497 * existing parameters of the association (e.g. number of outbound
1498 * streams) into the INIT ACK and cookie.
1499 *
1500 * After sending out the INIT ACK, the endpoint shall take no further
1501 * actions, i.e., the existing association, including its current state,
1502 * and the corresponding TCB MUST NOT be changed.
1503 *
1504 * Note: Only when a TCB exists and the association is not in a COOKIE-
1505 * WAIT state are the Tie-Tags populated. For a normal association INIT
1506 * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be
1507 * set to 0 (indicating that no previous TCB existed). The INIT ACK and
1508 * State Cookie are populated as specified in section 5.2.1.
1509 *
1510 * Verification Tag: Not specified, but an INIT has no way of knowing
1511 * what the verification tag could be, so we ignore it.
1512 *
1513 * Inputs
1514 * (endpoint, asoc, chunk)
1515 *
1516 * Outputs
1517 * (asoc, reply_msg, msg_up, timers, counters)
1518 *
1519 * The return value is the disposition of the chunk.
1520 */
1521sctp_disposition_t sctp_sf_do_5_2_2_dupinit(const struct sctp_endpoint *ep,
1522 const struct sctp_association *asoc,
1523 const sctp_subtype_t type,
1524 void *arg,
1525 sctp_cmd_seq_t *commands)
1526{
1527 /* Call helper to do the real work for both simulataneous and
1528 * duplicate INIT chunk handling.
1529 */
1530 return sctp_sf_do_unexpected_init(ep, asoc, type, arg, commands);
1531}
1532
1533
Vlad Yasevich610ab732007-01-15 19:18:30 -08001534/*
1535 * Unexpected INIT-ACK handler.
1536 *
1537 * Section 5.2.3
1538 * If an INIT ACK received by an endpoint in any state other than the
1539 * COOKIE-WAIT state, the endpoint should discard the INIT ACK chunk.
1540 * An unexpected INIT ACK usually indicates the processing of an old or
1541 * duplicated INIT chunk.
1542*/
1543sctp_disposition_t sctp_sf_do_5_2_3_initack(const struct sctp_endpoint *ep,
1544 const struct sctp_association *asoc,
1545 const sctp_subtype_t type,
1546 void *arg, sctp_cmd_seq_t *commands)
1547{
1548 /* Per the above section, we'll discard the chunk if we have an
1549 * endpoint. If this is an OOTB INIT-ACK, treat it as such.
1550 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001551 if (ep == sctp_sk((sctp_get_ctl_sock()))->ep)
Vlad Yasevich610ab732007-01-15 19:18:30 -08001552 return sctp_sf_ootb(ep, asoc, type, arg, commands);
1553 else
1554 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
1555}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001556
1557/* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A')
1558 *
1559 * Section 5.2.4
1560 * A) In this case, the peer may have restarted.
1561 */
1562static sctp_disposition_t sctp_sf_do_dupcook_a(const struct sctp_endpoint *ep,
1563 const struct sctp_association *asoc,
1564 struct sctp_chunk *chunk,
1565 sctp_cmd_seq_t *commands,
1566 struct sctp_association *new_asoc)
1567{
1568 sctp_init_chunk_t *peer_init;
1569 struct sctp_ulpevent *ev;
1570 struct sctp_chunk *repl;
1571 struct sctp_chunk *err;
1572 sctp_disposition_t disposition;
1573
1574 /* new_asoc is a brand-new association, so these are not yet
1575 * side effects--it is safe to run them here.
1576 */
1577 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1578
1579 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
1580 sctp_source(chunk), peer_init,
1581 GFP_ATOMIC))
1582 goto nomem;
1583
1584 /* Make sure no new addresses are being added during the
1585 * restart. Though this is a pretty complicated attack
1586 * since you'd have to get inside the cookie.
1587 */
1588 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk, commands)) {
1589 return SCTP_DISPOSITION_CONSUME;
1590 }
1591
1592 /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes
1593 * the peer has restarted (Action A), it MUST NOT setup a new
1594 * association but instead resend the SHUTDOWN ACK and send an ERROR
1595 * chunk with a "Cookie Received while Shutting Down" error cause to
1596 * its peer.
1597 */
1598 if (sctp_state(asoc, SHUTDOWN_ACK_SENT)) {
1599 disposition = sctp_sf_do_9_2_reshutack(ep, asoc,
1600 SCTP_ST_CHUNK(chunk->chunk_hdr->type),
1601 chunk, commands);
1602 if (SCTP_DISPOSITION_NOMEM == disposition)
1603 goto nomem;
1604
1605 err = sctp_make_op_error(asoc, chunk,
1606 SCTP_ERROR_COOKIE_IN_SHUTDOWN,
1607 NULL, 0);
1608 if (err)
1609 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1610 SCTP_CHUNK(err));
1611
1612 return SCTP_DISPOSITION_CONSUME;
1613 }
1614
1615 /* For now, fail any unsent/unacked data. Consider the optional
1616 * choice of resending of this data.
1617 */
1618 sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_OUTQUEUE, SCTP_NULL());
1619
Linus Torvalds1da177e2005-04-16 15:20:36 -07001620 repl = sctp_make_cookie_ack(new_asoc, chunk);
1621 if (!repl)
1622 goto nomem;
1623
Linus Torvalds1da177e2005-04-16 15:20:36 -07001624 /* Report association restart to upper layer. */
1625 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_RESTART, 0,
1626 new_asoc->c.sinit_num_ostreams,
1627 new_asoc->c.sinit_max_instreams,
Vlad Yasevicha5a35e72007-03-23 11:34:08 -07001628 NULL, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001629 if (!ev)
1630 goto nomem_ev;
1631
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001632 /* Update the content of current association. */
1633 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1634 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001635 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
1636 return SCTP_DISPOSITION_CONSUME;
1637
1638nomem_ev:
1639 sctp_chunk_free(repl);
1640nomem:
1641 return SCTP_DISPOSITION_NOMEM;
1642}
1643
1644/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B')
1645 *
1646 * Section 5.2.4
1647 * B) In this case, both sides may be attempting to start an association
1648 * at about the same time but the peer endpoint started its INIT
1649 * after responding to the local endpoint's INIT
1650 */
1651/* This case represents an initialization collision. */
1652static sctp_disposition_t sctp_sf_do_dupcook_b(const struct sctp_endpoint *ep,
1653 const struct sctp_association *asoc,
1654 struct sctp_chunk *chunk,
1655 sctp_cmd_seq_t *commands,
1656 struct sctp_association *new_asoc)
1657{
1658 sctp_init_chunk_t *peer_init;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001659 struct sctp_chunk *repl;
1660
1661 /* new_asoc is a brand-new association, so these are not yet
1662 * side effects--it is safe to run them here.
1663 */
1664 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1665 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
1666 sctp_source(chunk), peer_init,
1667 GFP_ATOMIC))
1668 goto nomem;
1669
1670 /* Update the content of current association. */
1671 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1672 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1673 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1674 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
1675 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
1676
1677 repl = sctp_make_cookie_ack(new_asoc, chunk);
1678 if (!repl)
1679 goto nomem;
1680
1681 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1682 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
1683
1684 /* RFC 2960 5.1 Normal Establishment of an Association
1685 *
1686 * D) IMPLEMENTATION NOTE: An implementation may choose to
1687 * send the Communication Up notification to the SCTP user
1688 * upon reception of a valid COOKIE ECHO chunk.
Vlad Yasevich07d93962007-05-04 13:55:27 -07001689 *
1690 * Sadly, this needs to be implemented as a side-effect, because
1691 * we are not guaranteed to have set the association id of the real
1692 * association and so these notifications need to be delayed until
1693 * the association id is allocated.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001694 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001695
Vlad Yasevich07d93962007-05-04 13:55:27 -07001696 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_CHANGE, SCTP_U8(SCTP_COMM_UP));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001697
1698 /* Sockets API Draft Section 5.3.1.6
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -08001699 * When a peer sends a Adaptation Layer Indication parameter , SCTP
Linus Torvalds1da177e2005-04-16 15:20:36 -07001700 * delivers this notification to inform the application that of the
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -08001701 * peers requested adaptation layer.
Vlad Yasevich07d93962007-05-04 13:55:27 -07001702 *
1703 * This also needs to be done as a side effect for the same reason as
1704 * above.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001705 */
Vlad Yasevich07d93962007-05-04 13:55:27 -07001706 if (asoc->peer.adaptation_ind)
1707 sctp_add_cmd_sf(commands, SCTP_CMD_ADAPTATION_IND, SCTP_NULL());
Linus Torvalds1da177e2005-04-16 15:20:36 -07001708
1709 return SCTP_DISPOSITION_CONSUME;
1710
Linus Torvalds1da177e2005-04-16 15:20:36 -07001711nomem:
1712 return SCTP_DISPOSITION_NOMEM;
1713}
1714
1715/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C')
1716 *
1717 * Section 5.2.4
1718 * C) In this case, the local endpoint's cookie has arrived late.
1719 * Before it arrived, the local endpoint sent an INIT and received an
1720 * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag
1721 * but a new tag of its own.
1722 */
1723/* This case represents an initialization collision. */
1724static sctp_disposition_t sctp_sf_do_dupcook_c(const struct sctp_endpoint *ep,
1725 const struct sctp_association *asoc,
1726 struct sctp_chunk *chunk,
1727 sctp_cmd_seq_t *commands,
1728 struct sctp_association *new_asoc)
1729{
1730 /* The cookie should be silently discarded.
1731 * The endpoint SHOULD NOT change states and should leave
1732 * any timers running.
1733 */
1734 return SCTP_DISPOSITION_DISCARD;
1735}
1736
1737/* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D')
1738 *
1739 * Section 5.2.4
1740 *
1741 * D) When both local and remote tags match the endpoint should always
1742 * enter the ESTABLISHED state, if it has not already done so.
1743 */
1744/* This case represents an initialization collision. */
1745static sctp_disposition_t sctp_sf_do_dupcook_d(const struct sctp_endpoint *ep,
1746 const struct sctp_association *asoc,
1747 struct sctp_chunk *chunk,
1748 sctp_cmd_seq_t *commands,
1749 struct sctp_association *new_asoc)
1750{
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001751 struct sctp_ulpevent *ev = NULL, *ai_ev = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001752 struct sctp_chunk *repl;
1753
1754 /* Clarification from Implementor's Guide:
1755 * D) When both local and remote tags match the endpoint should
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001756 * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state.
1757 * It should stop any cookie timer that may be running and send
1758 * a COOKIE ACK.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001759 */
1760
1761 /* Don't accidentally move back into established state. */
1762 if (asoc->state < SCTP_STATE_ESTABLISHED) {
1763 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1764 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1765 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1766 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1767 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
1768 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START,
1769 SCTP_NULL());
1770
1771 /* RFC 2960 5.1 Normal Establishment of an Association
1772 *
1773 * D) IMPLEMENTATION NOTE: An implementation may choose
1774 * to send the Communication Up notification to the
1775 * SCTP user upon reception of a valid COOKIE
1776 * ECHO chunk.
1777 */
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001778 ev = sctp_ulpevent_make_assoc_change(asoc, 0,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001779 SCTP_COMM_UP, 0,
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001780 asoc->c.sinit_num_ostreams,
1781 asoc->c.sinit_max_instreams,
Vlad Yasevicha5a35e72007-03-23 11:34:08 -07001782 NULL, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001783 if (!ev)
1784 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001785
1786 /* Sockets API Draft Section 5.3.1.6
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -08001787 * When a peer sends a Adaptation Layer Indication parameter,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001788 * SCTP delivers this notification to inform the application
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -08001789 * that of the peers requested adaptation layer.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001790 */
Ivan Skytte Jorgensen0f3fffd2006-12-20 16:07:04 -08001791 if (asoc->peer.adaptation_ind) {
1792 ai_ev = sctp_ulpevent_make_adaptation_indication(asoc,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001793 GFP_ATOMIC);
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001794 if (!ai_ev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001795 goto nomem;
1796
Linus Torvalds1da177e2005-04-16 15:20:36 -07001797 }
1798 }
1799 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
1800
1801 repl = sctp_make_cookie_ack(new_asoc, chunk);
1802 if (!repl)
1803 goto nomem;
1804
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001805 if (ev)
1806 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1807 SCTP_ULPEVENT(ev));
1808 if (ai_ev)
1809 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1810 SCTP_ULPEVENT(ai_ev));
1811
Linus Torvalds1da177e2005-04-16 15:20:36 -07001812 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1813 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
1814
1815 return SCTP_DISPOSITION_CONSUME;
1816
1817nomem:
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001818 if (ai_ev)
1819 sctp_ulpevent_free(ai_ev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001820 if (ev)
1821 sctp_ulpevent_free(ev);
1822 return SCTP_DISPOSITION_NOMEM;
1823}
1824
1825/*
1826 * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying
1827 * chunk was retransmitted and then delayed in the network.
1828 *
1829 * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists
1830 *
1831 * Verification Tag: None. Do cookie validation.
1832 *
1833 * Inputs
1834 * (endpoint, asoc, chunk)
1835 *
1836 * Outputs
1837 * (asoc, reply_msg, msg_up, timers, counters)
1838 *
1839 * The return value is the disposition of the chunk.
1840 */
1841sctp_disposition_t sctp_sf_do_5_2_4_dupcook(const struct sctp_endpoint *ep,
1842 const struct sctp_association *asoc,
1843 const sctp_subtype_t type,
1844 void *arg,
1845 sctp_cmd_seq_t *commands)
1846{
1847 sctp_disposition_t retval;
1848 struct sctp_chunk *chunk = arg;
1849 struct sctp_association *new_asoc;
1850 int error = 0;
1851 char action;
1852 struct sctp_chunk *err_chk_p;
1853
1854 /* Make sure that the chunk has a valid length from the protocol
1855 * perspective. In this case check to make sure we have at least
1856 * enough for the chunk header. Cookie length verification is
1857 * done later.
1858 */
1859 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
1860 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1861 commands);
1862
1863 /* "Decode" the chunk. We have no optional parameters so we
1864 * are in good shape.
1865 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09001866 chunk->subh.cookie_hdr = (struct sctp_signed_cookie *)chunk->skb->data;
Sridhar Samudrala62b08082006-05-05 17:04:43 -07001867 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
1868 sizeof(sctp_chunkhdr_t)))
1869 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001870
1871 /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
1872 * of a duplicate COOKIE ECHO match the Verification Tags of the
1873 * current association, consider the State Cookie valid even if
1874 * the lifespan is exceeded.
1875 */
1876 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
1877 &err_chk_p);
1878
1879 /* FIXME:
1880 * If the re-build failed, what is the proper error path
1881 * from here?
1882 *
1883 * [We should abort the association. --piggy]
1884 */
1885 if (!new_asoc) {
1886 /* FIXME: Several errors are possible. A bad cookie should
1887 * be silently discarded, but think about logging it too.
1888 */
1889 switch (error) {
1890 case -SCTP_IERROR_NOMEM:
1891 goto nomem;
1892
1893 case -SCTP_IERROR_STALE_COOKIE:
1894 sctp_send_stale_cookie_err(ep, asoc, chunk, commands,
1895 err_chk_p);
1896 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1897 case -SCTP_IERROR_BAD_SIG:
1898 default:
1899 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07001900 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001901 }
1902
1903 /* Compare the tie_tag in cookie with the verification tag of
1904 * current association.
1905 */
1906 action = sctp_tietags_compare(new_asoc, asoc);
1907
1908 switch (action) {
1909 case 'A': /* Association restart. */
1910 retval = sctp_sf_do_dupcook_a(ep, asoc, chunk, commands,
1911 new_asoc);
1912 break;
1913
1914 case 'B': /* Collision case B. */
1915 retval = sctp_sf_do_dupcook_b(ep, asoc, chunk, commands,
1916 new_asoc);
1917 break;
1918
1919 case 'C': /* Collision case C. */
1920 retval = sctp_sf_do_dupcook_c(ep, asoc, chunk, commands,
1921 new_asoc);
1922 break;
1923
1924 case 'D': /* Collision case D. */
1925 retval = sctp_sf_do_dupcook_d(ep, asoc, chunk, commands,
1926 new_asoc);
1927 break;
1928
1929 default: /* Discard packet for all others. */
1930 retval = sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1931 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07001932 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001933
1934 /* Delete the tempory new association. */
1935 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
1936 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
1937
1938 return retval;
1939
1940nomem:
1941 return SCTP_DISPOSITION_NOMEM;
1942}
1943
1944/*
1945 * Process an ABORT. (SHUTDOWN-PENDING state)
1946 *
1947 * See sctp_sf_do_9_1_abort().
1948 */
1949sctp_disposition_t sctp_sf_shutdown_pending_abort(
1950 const struct sctp_endpoint *ep,
1951 const struct sctp_association *asoc,
1952 const sctp_subtype_t type,
1953 void *arg,
1954 sctp_cmd_seq_t *commands)
1955{
1956 struct sctp_chunk *chunk = arg;
1957
1958 if (!sctp_vtag_verify_either(chunk, asoc))
1959 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1960
1961 /* Make sure that the ABORT chunk has a valid length.
1962 * Since this is an ABORT chunk, we have to discard it
1963 * because of the following text:
1964 * RFC 2960, Section 3.3.7
1965 * If an endpoint receives an ABORT with a format error or for an
1966 * association that doesn't exist, it MUST silently discard it.
1967 * Becasue the length is "invalid", we can't really discard just
1968 * as we do not know its true length. So, to be safe, discard the
1969 * packet.
1970 */
1971 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
1972 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1973
1974 /* Stop the T5-shutdown guard timer. */
1975 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1976 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
1977
1978 return sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
1979}
1980
1981/*
1982 * Process an ABORT. (SHUTDOWN-SENT state)
1983 *
1984 * See sctp_sf_do_9_1_abort().
1985 */
1986sctp_disposition_t sctp_sf_shutdown_sent_abort(const struct sctp_endpoint *ep,
1987 const struct sctp_association *asoc,
1988 const sctp_subtype_t type,
1989 void *arg,
1990 sctp_cmd_seq_t *commands)
1991{
1992 struct sctp_chunk *chunk = arg;
1993
1994 if (!sctp_vtag_verify_either(chunk, asoc))
1995 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1996
1997 /* Make sure that the ABORT chunk has a valid length.
1998 * Since this is an ABORT chunk, we have to discard it
1999 * because of the following text:
2000 * RFC 2960, Section 3.3.7
2001 * If an endpoint receives an ABORT with a format error or for an
2002 * association that doesn't exist, it MUST silently discard it.
2003 * Becasue the length is "invalid", we can't really discard just
2004 * as we do not know its true length. So, to be safe, discard the
2005 * packet.
2006 */
2007 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2008 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2009
2010 /* Stop the T2-shutdown timer. */
2011 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2012 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2013
2014 /* Stop the T5-shutdown guard timer. */
2015 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2016 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
2017
2018 return sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
2019}
2020
2021/*
2022 * Process an ABORT. (SHUTDOWN-ACK-SENT state)
2023 *
2024 * See sctp_sf_do_9_1_abort().
2025 */
2026sctp_disposition_t sctp_sf_shutdown_ack_sent_abort(
2027 const struct sctp_endpoint *ep,
2028 const struct sctp_association *asoc,
2029 const sctp_subtype_t type,
2030 void *arg,
2031 sctp_cmd_seq_t *commands)
2032{
2033 /* The same T2 timer, so we should be able to use
2034 * common function with the SHUTDOWN-SENT state.
2035 */
2036 return sctp_sf_shutdown_sent_abort(ep, asoc, type, arg, commands);
2037}
2038
2039/*
2040 * Handle an Error received in COOKIE_ECHOED state.
2041 *
2042 * Only handle the error type of stale COOKIE Error, the other errors will
2043 * be ignored.
2044 *
2045 * Inputs
2046 * (endpoint, asoc, chunk)
2047 *
2048 * Outputs
2049 * (asoc, reply_msg, msg_up, timers, counters)
2050 *
2051 * The return value is the disposition of the chunk.
2052 */
2053sctp_disposition_t sctp_sf_cookie_echoed_err(const struct sctp_endpoint *ep,
2054 const struct sctp_association *asoc,
2055 const sctp_subtype_t type,
2056 void *arg,
2057 sctp_cmd_seq_t *commands)
2058{
2059 struct sctp_chunk *chunk = arg;
2060 sctp_errhdr_t *err;
2061
2062 if (!sctp_vtag_verify(chunk, asoc))
2063 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2064
2065 /* Make sure that the ERROR chunk has a valid length.
2066 * The parameter walking depends on this as well.
2067 */
2068 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
2069 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2070 commands);
2071
2072 /* Process the error here */
2073 /* FUTURE FIXME: When PR-SCTP related and other optional
2074 * parms are emitted, this will have to change to handle multiple
2075 * errors.
2076 */
2077 sctp_walk_errors(err, chunk->chunk_hdr) {
2078 if (SCTP_ERROR_STALE_COOKIE == err->cause)
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002079 return sctp_sf_do_5_2_6_stale(ep, asoc, type,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002080 arg, commands);
2081 }
2082
2083 /* It is possible to have malformed error causes, and that
2084 * will cause us to end the walk early. However, since
2085 * we are discarding the packet, there should be no adverse
2086 * affects.
2087 */
2088 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2089}
2090
2091/*
2092 * Handle a Stale COOKIE Error
2093 *
2094 * Section: 5.2.6 Handle Stale COOKIE Error
2095 * If the association is in the COOKIE-ECHOED state, the endpoint may elect
2096 * one of the following three alternatives.
2097 * ...
2098 * 3) Send a new INIT chunk to the endpoint, adding a Cookie
2099 * Preservative parameter requesting an extension to the lifetime of
2100 * the State Cookie. When calculating the time extension, an
2101 * implementation SHOULD use the RTT information measured based on the
2102 * previous COOKIE ECHO / ERROR exchange, and should add no more
2103 * than 1 second beyond the measured RTT, due to long State Cookie
2104 * lifetimes making the endpoint more subject to a replay attack.
2105 *
2106 * Verification Tag: Not explicit, but safe to ignore.
2107 *
2108 * Inputs
2109 * (endpoint, asoc, chunk)
2110 *
2111 * Outputs
2112 * (asoc, reply_msg, msg_up, timers, counters)
2113 *
2114 * The return value is the disposition of the chunk.
2115 */
2116static sctp_disposition_t sctp_sf_do_5_2_6_stale(const struct sctp_endpoint *ep,
2117 const struct sctp_association *asoc,
2118 const sctp_subtype_t type,
2119 void *arg,
2120 sctp_cmd_seq_t *commands)
2121{
2122 struct sctp_chunk *chunk = arg;
2123 time_t stale;
2124 sctp_cookie_preserve_param_t bht;
2125 sctp_errhdr_t *err;
2126 struct sctp_chunk *reply;
2127 struct sctp_bind_addr *bp;
Frank Filz3f7a87d2005-06-20 13:14:57 -07002128 int attempts = asoc->init_err_counter + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002129
Vlad Yasevich81845c22006-01-30 15:59:54 -08002130 if (attempts > asoc->max_init_attempts) {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002131 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
2132 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002133 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08002134 SCTP_PERR(SCTP_ERROR_STALE_COOKIE));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002135 return SCTP_DISPOSITION_DELETE_TCB;
2136 }
2137
2138 err = (sctp_errhdr_t *)(chunk->skb->data);
2139
2140 /* When calculating the time extension, an implementation
2141 * SHOULD use the RTT information measured based on the
2142 * previous COOKIE ECHO / ERROR exchange, and should add no
2143 * more than 1 second beyond the measured RTT, due to long
2144 * State Cookie lifetimes making the endpoint more subject to
2145 * a replay attack.
2146 * Measure of Staleness's unit is usec. (1/1000000 sec)
2147 * Suggested Cookie Life-span Increment's unit is msec.
2148 * (1/1000 sec)
2149 * In general, if you use the suggested cookie life, the value
2150 * found in the field of measure of staleness should be doubled
2151 * to give ample time to retransmit the new cookie and thus
2152 * yield a higher probability of success on the reattempt.
2153 */
Al Viro34bcca22006-11-20 17:27:15 -08002154 stale = ntohl(*(__be32 *)((u8 *)err + sizeof(sctp_errhdr_t)));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002155 stale = (stale * 2) / 1000;
2156
2157 bht.param_hdr.type = SCTP_PARAM_COOKIE_PRESERVATIVE;
2158 bht.param_hdr.length = htons(sizeof(bht));
2159 bht.lifespan_increment = htonl(stale);
2160
2161 /* Build that new INIT chunk. */
2162 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
2163 reply = sctp_make_init(asoc, bp, GFP_ATOMIC, sizeof(bht));
2164 if (!reply)
2165 goto nomem;
2166
2167 sctp_addto_chunk(reply, sizeof(bht), &bht);
2168
2169 /* Clear peer's init_tag cached in assoc as we are sending a new INIT */
2170 sctp_add_cmd_sf(commands, SCTP_CMD_CLEAR_INIT_TAG, SCTP_NULL());
2171
2172 /* Stop pending T3-rtx and heartbeat timers */
2173 sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
2174 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
2175
2176 /* Delete non-primary peer ip addresses since we are transitioning
2177 * back to the COOKIE-WAIT state
2178 */
2179 sctp_add_cmd_sf(commands, SCTP_CMD_DEL_NON_PRIMARY, SCTP_NULL());
2180
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002181 /* If we've sent any data bundled with COOKIE-ECHO we will need to
2182 * resend
Linus Torvalds1da177e2005-04-16 15:20:36 -07002183 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002184 sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002185 SCTP_TRANSPORT(asoc->peer.primary_path));
2186
2187 /* Cast away the const modifier, as we want to just
2188 * rerun it through as a sideffect.
2189 */
Frank Filz3f7a87d2005-06-20 13:14:57 -07002190 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_INC, SCTP_NULL());
Linus Torvalds1da177e2005-04-16 15:20:36 -07002191
2192 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2193 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
2194 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2195 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
2196 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
2197 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
2198
2199 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2200
2201 return SCTP_DISPOSITION_CONSUME;
2202
2203nomem:
2204 return SCTP_DISPOSITION_NOMEM;
2205}
2206
2207/*
2208 * Process an ABORT.
2209 *
2210 * Section: 9.1
2211 * After checking the Verification Tag, the receiving endpoint shall
2212 * remove the association from its record, and shall report the
2213 * termination to its upper layer.
2214 *
2215 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
2216 * B) Rules for packet carrying ABORT:
2217 *
2218 * - The endpoint shall always fill in the Verification Tag field of the
2219 * outbound packet with the destination endpoint's tag value if it
2220 * is known.
2221 *
2222 * - If the ABORT is sent in response to an OOTB packet, the endpoint
2223 * MUST follow the procedure described in Section 8.4.
2224 *
2225 * - The receiver MUST accept the packet if the Verification Tag
2226 * matches either its own tag, OR the tag of its peer. Otherwise, the
2227 * receiver MUST silently discard the packet and take no further
2228 * action.
2229 *
2230 * Inputs
2231 * (endpoint, asoc, chunk)
2232 *
2233 * Outputs
2234 * (asoc, reply_msg, msg_up, timers, counters)
2235 *
2236 * The return value is the disposition of the chunk.
2237 */
2238sctp_disposition_t sctp_sf_do_9_1_abort(const struct sctp_endpoint *ep,
2239 const struct sctp_association *asoc,
2240 const sctp_subtype_t type,
2241 void *arg,
2242 sctp_cmd_seq_t *commands)
2243{
2244 struct sctp_chunk *chunk = arg;
2245 unsigned len;
Al Viro5be291f2006-11-20 17:01:06 -08002246 __be16 error = SCTP_ERROR_NO_ERROR;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002247
2248 if (!sctp_vtag_verify_either(chunk, asoc))
2249 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2250
2251 /* Make sure that the ABORT chunk has a valid length.
2252 * Since this is an ABORT chunk, we have to discard it
2253 * because of the following text:
2254 * RFC 2960, Section 3.3.7
2255 * If an endpoint receives an ABORT with a format error or for an
2256 * association that doesn't exist, it MUST silently discard it.
2257 * Becasue the length is "invalid", we can't really discard just
2258 * as we do not know its true length. So, to be safe, discard the
2259 * packet.
2260 */
2261 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2262 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2263
2264 /* See if we have an error cause code in the chunk. */
2265 len = ntohs(chunk->chunk_hdr->length);
2266 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
2267 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2268
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002269 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNRESET));
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002270 /* ASSOC_FAILED will DELETE_TCB. */
Al Viro5be291f2006-11-20 17:01:06 -08002271 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, SCTP_PERR(error));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002272 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
2273 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
2274
2275 return SCTP_DISPOSITION_ABORT;
2276}
2277
2278/*
2279 * Process an ABORT. (COOKIE-WAIT state)
2280 *
2281 * See sctp_sf_do_9_1_abort() above.
2282 */
2283sctp_disposition_t sctp_sf_cookie_wait_abort(const struct sctp_endpoint *ep,
2284 const struct sctp_association *asoc,
2285 const sctp_subtype_t type,
2286 void *arg,
2287 sctp_cmd_seq_t *commands)
2288{
2289 struct sctp_chunk *chunk = arg;
2290 unsigned len;
Al Virof94c0192006-11-20 17:00:25 -08002291 __be16 error = SCTP_ERROR_NO_ERROR;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002292
2293 if (!sctp_vtag_verify_either(chunk, asoc))
2294 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2295
2296 /* Make sure that the ABORT chunk has a valid length.
2297 * Since this is an ABORT chunk, we have to discard it
2298 * because of the following text:
2299 * RFC 2960, Section 3.3.7
2300 * If an endpoint receives an ABORT with a format error or for an
2301 * association that doesn't exist, it MUST silently discard it.
2302 * Becasue the length is "invalid", we can't really discard just
2303 * as we do not know its true length. So, to be safe, discard the
2304 * packet.
2305 */
2306 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2307 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2308
2309 /* See if we have an error cause code in the chunk. */
2310 len = ntohs(chunk->chunk_hdr->length);
2311 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
2312 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2313
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002314 return sctp_stop_t1_and_abort(commands, error, ECONNREFUSED, asoc,
2315 chunk->transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002316}
2317
2318/*
2319 * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state)
2320 */
2321sctp_disposition_t sctp_sf_cookie_wait_icmp_abort(const struct sctp_endpoint *ep,
2322 const struct sctp_association *asoc,
2323 const sctp_subtype_t type,
2324 void *arg,
2325 sctp_cmd_seq_t *commands)
2326{
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002327 return sctp_stop_t1_and_abort(commands, SCTP_ERROR_NO_ERROR,
2328 ENOPROTOOPT, asoc,
Frank Filz3f7a87d2005-06-20 13:14:57 -07002329 (struct sctp_transport *)arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002330}
2331
2332/*
2333 * Process an ABORT. (COOKIE-ECHOED state)
2334 */
2335sctp_disposition_t sctp_sf_cookie_echoed_abort(const struct sctp_endpoint *ep,
2336 const struct sctp_association *asoc,
2337 const sctp_subtype_t type,
2338 void *arg,
2339 sctp_cmd_seq_t *commands)
2340{
2341 /* There is a single T1 timer, so we should be able to use
2342 * common function with the COOKIE-WAIT state.
2343 */
2344 return sctp_sf_cookie_wait_abort(ep, asoc, type, arg, commands);
2345}
2346
2347/*
2348 * Stop T1 timer and abort association with "INIT failed".
2349 *
2350 * This is common code called by several sctp_sf_*_abort() functions above.
2351 */
Adrian Bunk52c1da32005-06-23 22:05:33 -07002352static sctp_disposition_t sctp_stop_t1_and_abort(sctp_cmd_seq_t *commands,
Al Virof94c0192006-11-20 17:00:25 -08002353 __be16 error, int sk_err,
Frank Filz3f7a87d2005-06-20 13:14:57 -07002354 const struct sctp_association *asoc,
2355 struct sctp_transport *transport)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002356{
Frank Filz3f7a87d2005-06-20 13:14:57 -07002357 SCTP_DEBUG_PRINTK("ABORT received (INIT).\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07002358 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2359 SCTP_STATE(SCTP_STATE_CLOSED));
2360 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
2361 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2362 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002363 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(sk_err));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002364 /* CMD_INIT_FAILED will DELETE_TCB. */
2365 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08002366 SCTP_PERR(error));
Frank Filz3f7a87d2005-06-20 13:14:57 -07002367 return SCTP_DISPOSITION_ABORT;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002368}
2369
2370/*
2371 * sctp_sf_do_9_2_shut
2372 *
2373 * Section: 9.2
2374 * Upon the reception of the SHUTDOWN, the peer endpoint shall
2375 * - enter the SHUTDOWN-RECEIVED state,
2376 *
2377 * - stop accepting new data from its SCTP user
2378 *
2379 * - verify, by checking the Cumulative TSN Ack field of the chunk,
2380 * that all its outstanding DATA chunks have been received by the
2381 * SHUTDOWN sender.
2382 *
2383 * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT
2384 * send a SHUTDOWN in response to a ULP request. And should discard
2385 * subsequent SHUTDOWN chunks.
2386 *
2387 * If there are still outstanding DATA chunks left, the SHUTDOWN
2388 * receiver shall continue to follow normal data transmission
2389 * procedures defined in Section 6 until all outstanding DATA chunks
2390 * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept
2391 * new data from its SCTP user.
2392 *
2393 * Verification Tag: 8.5 Verification Tag [Normal verification]
2394 *
2395 * Inputs
2396 * (endpoint, asoc, chunk)
2397 *
2398 * Outputs
2399 * (asoc, reply_msg, msg_up, timers, counters)
2400 *
2401 * The return value is the disposition of the chunk.
2402 */
2403sctp_disposition_t sctp_sf_do_9_2_shutdown(const struct sctp_endpoint *ep,
2404 const struct sctp_association *asoc,
2405 const sctp_subtype_t type,
2406 void *arg,
2407 sctp_cmd_seq_t *commands)
2408{
2409 struct sctp_chunk *chunk = arg;
2410 sctp_shutdownhdr_t *sdh;
2411 sctp_disposition_t disposition;
2412 struct sctp_ulpevent *ev;
2413
2414 if (!sctp_vtag_verify(chunk, asoc))
2415 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2416
2417 /* Make sure that the SHUTDOWN chunk has a valid length. */
2418 if (!sctp_chunk_length_valid(chunk,
2419 sizeof(struct sctp_shutdown_chunk_t)))
2420 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2421 commands);
2422
2423 /* Convert the elaborate header. */
2424 sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
2425 skb_pull(chunk->skb, sizeof(sctp_shutdownhdr_t));
2426 chunk->subh.shutdown_hdr = sdh;
2427
Sridhar Samudralaeb0e0072005-09-22 23:48:38 -07002428 /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT
2429 * When a peer sends a SHUTDOWN, SCTP delivers this notification to
2430 * inform the application that it should cease sending data.
2431 */
2432 ev = sctp_ulpevent_make_shutdown_event(asoc, 0, GFP_ATOMIC);
2433 if (!ev) {
2434 disposition = SCTP_DISPOSITION_NOMEM;
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002435 goto out;
Sridhar Samudralaeb0e0072005-09-22 23:48:38 -07002436 }
2437 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
2438
Linus Torvalds1da177e2005-04-16 15:20:36 -07002439 /* Upon the reception of the SHUTDOWN, the peer endpoint shall
2440 * - enter the SHUTDOWN-RECEIVED state,
2441 * - stop accepting new data from its SCTP user
2442 *
2443 * [This is implicit in the new state.]
2444 */
2445 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2446 SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED));
2447 disposition = SCTP_DISPOSITION_CONSUME;
2448
2449 if (sctp_outq_is_empty(&asoc->outqueue)) {
2450 disposition = sctp_sf_do_9_2_shutdown_ack(ep, asoc, type,
2451 arg, commands);
2452 }
2453
2454 if (SCTP_DISPOSITION_NOMEM == disposition)
2455 goto out;
2456
2457 /* - verify, by checking the Cumulative TSN Ack field of the
2458 * chunk, that all its outstanding DATA chunks have been
2459 * received by the SHUTDOWN sender.
2460 */
2461 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
Al Viro2178eda2006-11-20 17:26:53 -08002462 SCTP_BE32(chunk->subh.shutdown_hdr->cum_tsn_ack));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002463
Linus Torvalds1da177e2005-04-16 15:20:36 -07002464out:
2465 return disposition;
2466}
2467
2468/* RFC 2960 9.2
2469 * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk
2470 * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination
2471 * transport addresses (either in the IP addresses or in the INIT chunk)
2472 * that belong to this association, it should discard the INIT chunk and
2473 * retransmit the SHUTDOWN ACK chunk.
2474 */
2475sctp_disposition_t sctp_sf_do_9_2_reshutack(const struct sctp_endpoint *ep,
2476 const struct sctp_association *asoc,
2477 const sctp_subtype_t type,
2478 void *arg,
2479 sctp_cmd_seq_t *commands)
2480{
2481 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
2482 struct sctp_chunk *reply;
2483
2484 /* Since we are not going to really process this INIT, there
2485 * is no point in verifying chunk boundries. Just generate
2486 * the SHUTDOWN ACK.
2487 */
2488 reply = sctp_make_shutdown_ack(asoc, chunk);
2489 if (NULL == reply)
2490 goto nomem;
2491
2492 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
2493 * the T2-SHUTDOWN timer.
2494 */
2495 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
2496
2497 /* and restart the T2-shutdown timer. */
2498 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2499 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2500
2501 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2502
2503 return SCTP_DISPOSITION_CONSUME;
2504nomem:
2505 return SCTP_DISPOSITION_NOMEM;
2506}
2507
2508/*
2509 * sctp_sf_do_ecn_cwr
2510 *
2511 * Section: Appendix A: Explicit Congestion Notification
2512 *
2513 * CWR:
2514 *
2515 * RFC 2481 details a specific bit for a sender to send in the header of
2516 * its next outbound TCP segment to indicate to its peer that it has
2517 * reduced its congestion window. This is termed the CWR bit. For
2518 * SCTP the same indication is made by including the CWR chunk.
2519 * This chunk contains one data element, i.e. the TSN number that
2520 * was sent in the ECNE chunk. This element represents the lowest
2521 * TSN number in the datagram that was originally marked with the
2522 * CE bit.
2523 *
2524 * Verification Tag: 8.5 Verification Tag [Normal verification]
2525 * Inputs
2526 * (endpoint, asoc, chunk)
2527 *
2528 * Outputs
2529 * (asoc, reply_msg, msg_up, timers, counters)
2530 *
2531 * The return value is the disposition of the chunk.
2532 */
2533sctp_disposition_t sctp_sf_do_ecn_cwr(const struct sctp_endpoint *ep,
2534 const struct sctp_association *asoc,
2535 const sctp_subtype_t type,
2536 void *arg,
2537 sctp_cmd_seq_t *commands)
2538{
2539 sctp_cwrhdr_t *cwr;
2540 struct sctp_chunk *chunk = arg;
Al Viro34bcca22006-11-20 17:27:15 -08002541 u32 lowest_tsn;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002542
2543 if (!sctp_vtag_verify(chunk, asoc))
2544 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2545
2546 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2547 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2548 commands);
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002549
Linus Torvalds1da177e2005-04-16 15:20:36 -07002550 cwr = (sctp_cwrhdr_t *) chunk->skb->data;
2551 skb_pull(chunk->skb, sizeof(sctp_cwrhdr_t));
2552
Al Viro34bcca22006-11-20 17:27:15 -08002553 lowest_tsn = ntohl(cwr->lowest_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002554
2555 /* Does this CWR ack the last sent congestion notification? */
Al Viro34bcca22006-11-20 17:27:15 -08002556 if (TSN_lte(asoc->last_ecne_tsn, lowest_tsn)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002557 /* Stop sending ECNE. */
2558 sctp_add_cmd_sf(commands,
2559 SCTP_CMD_ECN_CWR,
Al Viro34bcca22006-11-20 17:27:15 -08002560 SCTP_U32(lowest_tsn));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002561 }
2562 return SCTP_DISPOSITION_CONSUME;
2563}
2564
2565/*
2566 * sctp_sf_do_ecne
2567 *
2568 * Section: Appendix A: Explicit Congestion Notification
2569 *
2570 * ECN-Echo
2571 *
2572 * RFC 2481 details a specific bit for a receiver to send back in its
2573 * TCP acknowledgements to notify the sender of the Congestion
2574 * Experienced (CE) bit having arrived from the network. For SCTP this
2575 * same indication is made by including the ECNE chunk. This chunk
2576 * contains one data element, i.e. the lowest TSN associated with the IP
2577 * datagram marked with the CE bit.....
2578 *
2579 * Verification Tag: 8.5 Verification Tag [Normal verification]
2580 * Inputs
2581 * (endpoint, asoc, chunk)
2582 *
2583 * Outputs
2584 * (asoc, reply_msg, msg_up, timers, counters)
2585 *
2586 * The return value is the disposition of the chunk.
2587 */
2588sctp_disposition_t sctp_sf_do_ecne(const struct sctp_endpoint *ep,
2589 const struct sctp_association *asoc,
2590 const sctp_subtype_t type,
2591 void *arg,
2592 sctp_cmd_seq_t *commands)
2593{
2594 sctp_ecnehdr_t *ecne;
2595 struct sctp_chunk *chunk = arg;
2596
2597 if (!sctp_vtag_verify(chunk, asoc))
2598 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2599
2600 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2601 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2602 commands);
2603
2604 ecne = (sctp_ecnehdr_t *) chunk->skb->data;
2605 skb_pull(chunk->skb, sizeof(sctp_ecnehdr_t));
2606
2607 /* If this is a newer ECNE than the last CWR packet we sent out */
2608 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_ECNE,
2609 SCTP_U32(ntohl(ecne->lowest_tsn)));
2610
2611 return SCTP_DISPOSITION_CONSUME;
2612}
2613
2614/*
2615 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
2616 *
2617 * The SCTP endpoint MUST always acknowledge the reception of each valid
2618 * DATA chunk.
2619 *
2620 * The guidelines on delayed acknowledgement algorithm specified in
2621 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
2622 * acknowledgement SHOULD be generated for at least every second packet
2623 * (not every second DATA chunk) received, and SHOULD be generated within
2624 * 200 ms of the arrival of any unacknowledged DATA chunk. In some
2625 * situations it may be beneficial for an SCTP transmitter to be more
2626 * conservative than the algorithms detailed in this document allow.
2627 * However, an SCTP transmitter MUST NOT be more aggressive than the
2628 * following algorithms allow.
2629 *
2630 * A SCTP receiver MUST NOT generate more than one SACK for every
2631 * incoming packet, other than to update the offered window as the
2632 * receiving application consumes new data.
2633 *
2634 * Verification Tag: 8.5 Verification Tag [Normal verification]
2635 *
2636 * Inputs
2637 * (endpoint, asoc, chunk)
2638 *
2639 * Outputs
2640 * (asoc, reply_msg, msg_up, timers, counters)
2641 *
2642 * The return value is the disposition of the chunk.
2643 */
2644sctp_disposition_t sctp_sf_eat_data_6_2(const struct sctp_endpoint *ep,
2645 const struct sctp_association *asoc,
2646 const sctp_subtype_t type,
2647 void *arg,
2648 sctp_cmd_seq_t *commands)
2649{
2650 struct sctp_chunk *chunk = arg;
2651 int error;
2652
2653 if (!sctp_vtag_verify(chunk, asoc)) {
2654 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
2655 SCTP_NULL());
2656 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002657 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002658
2659 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
2660 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2661 commands);
2662
2663 error = sctp_eat_data(asoc, chunk, commands );
2664 switch (error) {
2665 case SCTP_IERROR_NO_ERROR:
2666 break;
2667 case SCTP_IERROR_HIGH_TSN:
2668 case SCTP_IERROR_BAD_STREAM:
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07002669 SCTP_INC_STATS(SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002670 goto discard_noforce;
2671 case SCTP_IERROR_DUP_TSN:
2672 case SCTP_IERROR_IGNORE_TSN:
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07002673 SCTP_INC_STATS(SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002674 goto discard_force;
2675 case SCTP_IERROR_NO_DATA:
2676 goto consume;
2677 default:
2678 BUG();
2679 }
2680
2681 if (asoc->autoclose) {
2682 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2683 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
2684 }
2685
2686 /* If this is the last chunk in a packet, we need to count it
2687 * toward sack generation. Note that we need to SACK every
2688 * OTHER packet containing data chunks, EVEN IF WE DISCARD
2689 * THEM. We elect to NOT generate SACK's if the chunk fails
2690 * the verification tag test.
2691 *
2692 * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2693 *
2694 * The SCTP endpoint MUST always acknowledge the reception of
2695 * each valid DATA chunk.
2696 *
2697 * The guidelines on delayed acknowledgement algorithm
2698 * specified in Section 4.2 of [RFC2581] SHOULD be followed.
2699 * Specifically, an acknowledgement SHOULD be generated for at
2700 * least every second packet (not every second DATA chunk)
2701 * received, and SHOULD be generated within 200 ms of the
2702 * arrival of any unacknowledged DATA chunk. In some
2703 * situations it may be beneficial for an SCTP transmitter to
2704 * be more conservative than the algorithms detailed in this
2705 * document allow. However, an SCTP transmitter MUST NOT be
2706 * more aggressive than the following algorithms allow.
2707 */
Frank Filz52ccb8e2005-12-22 11:36:46 -08002708 if (chunk->end_of_packet)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002709 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
2710
Linus Torvalds1da177e2005-04-16 15:20:36 -07002711 return SCTP_DISPOSITION_CONSUME;
2712
2713discard_force:
2714 /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2715 *
2716 * When a packet arrives with duplicate DATA chunk(s) and with
2717 * no new DATA chunk(s), the endpoint MUST immediately send a
2718 * SACK with no delay. If a packet arrives with duplicate
2719 * DATA chunk(s) bundled with new DATA chunks, the endpoint
2720 * MAY immediately send a SACK. Normally receipt of duplicate
2721 * DATA chunks will occur when the original SACK chunk was lost
2722 * and the peer's RTO has expired. The duplicate TSN number(s)
2723 * SHOULD be reported in the SACK as duplicate.
2724 */
2725 /* In our case, we split the MAY SACK advice up whether or not
2726 * the last chunk is a duplicate.'
2727 */
2728 if (chunk->end_of_packet)
2729 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
2730 return SCTP_DISPOSITION_DISCARD;
2731
2732discard_noforce:
Frank Filz52ccb8e2005-12-22 11:36:46 -08002733 if (chunk->end_of_packet)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002734 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
2735
Linus Torvalds1da177e2005-04-16 15:20:36 -07002736 return SCTP_DISPOSITION_DISCARD;
2737consume:
2738 return SCTP_DISPOSITION_CONSUME;
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002739
Linus Torvalds1da177e2005-04-16 15:20:36 -07002740}
2741
2742/*
2743 * sctp_sf_eat_data_fast_4_4
2744 *
2745 * Section: 4 (4)
2746 * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received
2747 * DATA chunks without delay.
2748 *
2749 * Verification Tag: 8.5 Verification Tag [Normal verification]
2750 * Inputs
2751 * (endpoint, asoc, chunk)
2752 *
2753 * Outputs
2754 * (asoc, reply_msg, msg_up, timers, counters)
2755 *
2756 * The return value is the disposition of the chunk.
2757 */
2758sctp_disposition_t sctp_sf_eat_data_fast_4_4(const struct sctp_endpoint *ep,
2759 const struct sctp_association *asoc,
2760 const sctp_subtype_t type,
2761 void *arg,
2762 sctp_cmd_seq_t *commands)
2763{
2764 struct sctp_chunk *chunk = arg;
2765 int error;
2766
2767 if (!sctp_vtag_verify(chunk, asoc)) {
2768 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
2769 SCTP_NULL());
2770 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2771 }
2772
2773 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
2774 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2775 commands);
2776
2777 error = sctp_eat_data(asoc, chunk, commands );
2778 switch (error) {
2779 case SCTP_IERROR_NO_ERROR:
2780 case SCTP_IERROR_HIGH_TSN:
2781 case SCTP_IERROR_DUP_TSN:
2782 case SCTP_IERROR_IGNORE_TSN:
2783 case SCTP_IERROR_BAD_STREAM:
2784 break;
2785 case SCTP_IERROR_NO_DATA:
2786 goto consume;
2787 default:
2788 BUG();
2789 }
2790
2791 /* Go a head and force a SACK, since we are shutting down. */
2792
2793 /* Implementor's Guide.
2794 *
2795 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
2796 * respond to each received packet containing one or more DATA chunk(s)
2797 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
2798 */
2799 if (chunk->end_of_packet) {
2800 /* We must delay the chunk creation since the cumulative
2801 * TSN has not been updated yet.
2802 */
2803 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
2804 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
2805 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2806 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2807 }
2808
2809consume:
2810 return SCTP_DISPOSITION_CONSUME;
2811}
2812
2813/*
2814 * Section: 6.2 Processing a Received SACK
2815 * D) Any time a SACK arrives, the endpoint performs the following:
2816 *
2817 * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point,
2818 * then drop the SACK. Since Cumulative TSN Ack is monotonically
2819 * increasing, a SACK whose Cumulative TSN Ack is less than the
2820 * Cumulative TSN Ack Point indicates an out-of-order SACK.
2821 *
2822 * ii) Set rwnd equal to the newly received a_rwnd minus the number
2823 * of bytes still outstanding after processing the Cumulative TSN Ack
2824 * and the Gap Ack Blocks.
2825 *
2826 * iii) If the SACK is missing a TSN that was previously
2827 * acknowledged via a Gap Ack Block (e.g., the data receiver
2828 * reneged on the data), then mark the corresponding DATA chunk
2829 * as available for retransmit: Mark it as missing for fast
2830 * retransmit as described in Section 7.2.4 and if no retransmit
2831 * timer is running for the destination address to which the DATA
2832 * chunk was originally transmitted, then T3-rtx is started for
2833 * that destination address.
2834 *
2835 * Verification Tag: 8.5 Verification Tag [Normal verification]
2836 *
2837 * Inputs
2838 * (endpoint, asoc, chunk)
2839 *
2840 * Outputs
2841 * (asoc, reply_msg, msg_up, timers, counters)
2842 *
2843 * The return value is the disposition of the chunk.
2844 */
2845sctp_disposition_t sctp_sf_eat_sack_6_2(const struct sctp_endpoint *ep,
2846 const struct sctp_association *asoc,
2847 const sctp_subtype_t type,
2848 void *arg,
2849 sctp_cmd_seq_t *commands)
2850{
2851 struct sctp_chunk *chunk = arg;
2852 sctp_sackhdr_t *sackh;
2853 __u32 ctsn;
2854
2855 if (!sctp_vtag_verify(chunk, asoc))
2856 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2857
2858 /* Make sure that the SACK chunk has a valid length. */
2859 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_sack_chunk_t)))
2860 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2861 commands);
2862
2863 /* Pull the SACK chunk from the data buffer */
2864 sackh = sctp_sm_pull_sack(chunk);
2865 /* Was this a bogus SACK? */
2866 if (!sackh)
2867 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2868 chunk->subh.sack_hdr = sackh;
2869 ctsn = ntohl(sackh->cum_tsn_ack);
2870
2871 /* i) If Cumulative TSN Ack is less than the Cumulative TSN
2872 * Ack Point, then drop the SACK. Since Cumulative TSN
2873 * Ack is monotonically increasing, a SACK whose
2874 * Cumulative TSN Ack is less than the Cumulative TSN Ack
2875 * Point indicates an out-of-order SACK.
2876 */
2877 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
2878 SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn);
2879 SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc->ctsn_ack_point);
2880 return SCTP_DISPOSITION_DISCARD;
2881 }
2882
2883 /* Return this SACK for further processing. */
2884 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_SACKH(sackh));
2885
2886 /* Note: We do the rest of the work on the PROCESS_SACK
2887 * sideeffect.
2888 */
2889 return SCTP_DISPOSITION_CONSUME;
2890}
2891
2892/*
2893 * Generate an ABORT in response to a packet.
2894 *
Jerome Forissier047a2422005-04-28 11:58:43 -07002895 * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41
Linus Torvalds1da177e2005-04-16 15:20:36 -07002896 *
Jerome Forissier047a2422005-04-28 11:58:43 -07002897 * 8) The receiver should respond to the sender of the OOTB packet with
2898 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
2899 * MUST fill in the Verification Tag field of the outbound packet
2900 * with the value found in the Verification Tag field of the OOTB
2901 * packet and set the T-bit in the Chunk Flags to indicate that the
2902 * Verification Tag is reflected. After sending this ABORT, the
2903 * receiver of the OOTB packet shall discard the OOTB packet and take
2904 * no further action.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002905 *
2906 * Verification Tag:
2907 *
2908 * The return value is the disposition of the chunk.
2909*/
2910sctp_disposition_t sctp_sf_tabort_8_4_8(const struct sctp_endpoint *ep,
2911 const struct sctp_association *asoc,
2912 const sctp_subtype_t type,
2913 void *arg,
2914 sctp_cmd_seq_t *commands)
2915{
2916 struct sctp_packet *packet = NULL;
2917 struct sctp_chunk *chunk = arg;
2918 struct sctp_chunk *abort;
2919
2920 packet = sctp_ootb_pkt_new(asoc, chunk);
2921
2922 if (packet) {
2923 /* Make an ABORT. The T bit will be set if the asoc
2924 * is NULL.
2925 */
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002926 abort = sctp_make_abort(asoc, chunk, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002927 if (!abort) {
2928 sctp_ootb_pkt_free(packet);
2929 return SCTP_DISPOSITION_NOMEM;
2930 }
2931
Jerome Forissier047a2422005-04-28 11:58:43 -07002932 /* Reflect vtag if T-Bit is set */
2933 if (sctp_test_T_bit(abort))
2934 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
2935
Linus Torvalds1da177e2005-04-16 15:20:36 -07002936 /* Set the skb to the belonging sock for accounting. */
2937 abort->skb->sk = ep->base.sk;
2938
2939 sctp_packet_append_chunk(packet, abort);
2940
2941 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
2942 SCTP_PACKET(packet));
2943
2944 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
2945
2946 return SCTP_DISPOSITION_CONSUME;
2947 }
2948
2949 return SCTP_DISPOSITION_NOMEM;
2950}
2951
2952/*
2953 * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR
2954 * event as ULP notification for each cause included in the chunk.
2955 *
2956 * API 5.3.1.3 - SCTP_REMOTE_ERROR
2957 *
2958 * The return value is the disposition of the chunk.
2959*/
2960sctp_disposition_t sctp_sf_operr_notify(const struct sctp_endpoint *ep,
2961 const struct sctp_association *asoc,
2962 const sctp_subtype_t type,
2963 void *arg,
2964 sctp_cmd_seq_t *commands)
2965{
2966 struct sctp_chunk *chunk = arg;
2967 struct sctp_ulpevent *ev;
2968
2969 if (!sctp_vtag_verify(chunk, asoc))
2970 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2971
2972 /* Make sure that the ERROR chunk has a valid length. */
2973 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
2974 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2975 commands);
2976
2977 while (chunk->chunk_end > chunk->skb->data) {
2978 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
2979 GFP_ATOMIC);
2980 if (!ev)
2981 goto nomem;
2982
2983 if (!sctp_add_cmd(commands, SCTP_CMD_EVENT_ULP,
2984 SCTP_ULPEVENT(ev))) {
2985 sctp_ulpevent_free(ev);
2986 goto nomem;
2987 }
2988
2989 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_OPERR,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09002990 SCTP_CHUNK(chunk));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002991 }
2992 return SCTP_DISPOSITION_CONSUME;
2993
2994nomem:
2995 return SCTP_DISPOSITION_NOMEM;
2996}
2997
2998/*
2999 * Process an inbound SHUTDOWN ACK.
3000 *
3001 * From Section 9.2:
3002 * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3003 * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its
3004 * peer, and remove all record of the association.
3005 *
3006 * The return value is the disposition.
3007 */
3008sctp_disposition_t sctp_sf_do_9_2_final(const struct sctp_endpoint *ep,
3009 const struct sctp_association *asoc,
3010 const sctp_subtype_t type,
3011 void *arg,
3012 sctp_cmd_seq_t *commands)
3013{
3014 struct sctp_chunk *chunk = arg;
3015 struct sctp_chunk *reply;
3016 struct sctp_ulpevent *ev;
3017
3018 if (!sctp_vtag_verify(chunk, asoc))
3019 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3020
3021 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3022 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3023 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3024 commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003025 /* 10.2 H) SHUTDOWN COMPLETE notification
3026 *
3027 * When SCTP completes the shutdown procedures (section 9.2) this
3028 * notification is passed to the upper layer.
3029 */
3030 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
Vlad Yasevicha5a35e72007-03-23 11:34:08 -07003031 0, 0, 0, NULL, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003032 if (!ev)
3033 goto nomem;
3034
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07003035 /* ...send a SHUTDOWN COMPLETE chunk to its peer, */
3036 reply = sctp_make_shutdown_complete(asoc, chunk);
3037 if (!reply)
3038 goto nomem_chunk;
3039
3040 /* Do all the commands now (after allocation), so that we
3041 * have consistent state if memory allocation failes
3042 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003043 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
3044
3045 /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3046 * stop the T2-shutdown timer,
3047 */
3048 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3049 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3050
3051 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3052 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
3053
Linus Torvalds1da177e2005-04-16 15:20:36 -07003054 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3055 SCTP_STATE(SCTP_STATE_CLOSED));
3056 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
3057 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3058 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
3059
3060 /* ...and remove all record of the association. */
3061 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
3062 return SCTP_DISPOSITION_DELETE_TCB;
3063
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07003064nomem_chunk:
3065 sctp_ulpevent_free(ev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003066nomem:
3067 return SCTP_DISPOSITION_NOMEM;
3068}
3069
3070/*
Jerome Forissier047a2422005-04-28 11:58:43 -07003071 * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41.
3072 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003073 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3074 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3075 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3076 * packet must fill in the Verification Tag field of the outbound
3077 * packet with the Verification Tag received in the SHUTDOWN ACK and
Jerome Forissier047a2422005-04-28 11:58:43 -07003078 * set the T-bit in the Chunk Flags to indicate that the Verification
3079 * Tag is reflected.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003080 *
3081 * 8) The receiver should respond to the sender of the OOTB packet with
3082 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3083 * MUST fill in the Verification Tag field of the outbound packet
3084 * with the value found in the Verification Tag field of the OOTB
Jerome Forissier047a2422005-04-28 11:58:43 -07003085 * packet and set the T-bit in the Chunk Flags to indicate that the
3086 * Verification Tag is reflected. After sending this ABORT, the
3087 * receiver of the OOTB packet shall discard the OOTB packet and take
3088 * no further action.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003089 */
3090sctp_disposition_t sctp_sf_ootb(const struct sctp_endpoint *ep,
3091 const struct sctp_association *asoc,
3092 const sctp_subtype_t type,
3093 void *arg,
3094 sctp_cmd_seq_t *commands)
3095{
3096 struct sctp_chunk *chunk = arg;
3097 struct sk_buff *skb = chunk->skb;
3098 sctp_chunkhdr_t *ch;
3099 __u8 *ch_end;
3100 int ootb_shut_ack = 0;
3101
3102 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES);
3103
3104 ch = (sctp_chunkhdr_t *) chunk->chunk_hdr;
3105 do {
3106 /* Break out if chunk length is less then minimal. */
3107 if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t))
3108 break;
3109
3110 ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07003111 if (ch_end > skb_tail_pointer(skb))
Tsutomu Fujiia7d1f1b2006-01-17 11:57:09 -08003112 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003113
3114 if (SCTP_CID_SHUTDOWN_ACK == ch->type)
3115 ootb_shut_ack = 1;
3116
3117 /* RFC 2960, Section 3.3.7
3118 * Moreover, under any circumstances, an endpoint that
3119 * receives an ABORT MUST NOT respond to that ABORT by
3120 * sending an ABORT of its own.
3121 */
3122 if (SCTP_CID_ABORT == ch->type)
3123 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003124
Linus Torvalds1da177e2005-04-16 15:20:36 -07003125 ch = (sctp_chunkhdr_t *) ch_end;
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -07003126 } while (ch_end < skb_tail_pointer(skb));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003127
3128 if (ootb_shut_ack)
3129 sctp_sf_shut_8_4_5(ep, asoc, type, arg, commands);
3130 else
3131 sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
3132
3133 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3134}
3135
3136/*
3137 * Handle an "Out of the blue" SHUTDOWN ACK.
3138 *
Jerome Forissier047a2422005-04-28 11:58:43 -07003139 * Section: 8.4 5, sctpimpguide 2.41.
3140 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003141 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
Jerome Forissier047a2422005-04-28 11:58:43 -07003142 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3143 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3144 * packet must fill in the Verification Tag field of the outbound
3145 * packet with the Verification Tag received in the SHUTDOWN ACK and
3146 * set the T-bit in the Chunk Flags to indicate that the Verification
3147 * Tag is reflected.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003148 *
3149 * Inputs
3150 * (endpoint, asoc, type, arg, commands)
3151 *
3152 * Outputs
3153 * (sctp_disposition_t)
3154 *
3155 * The return value is the disposition of the chunk.
3156 */
3157static sctp_disposition_t sctp_sf_shut_8_4_5(const struct sctp_endpoint *ep,
3158 const struct sctp_association *asoc,
3159 const sctp_subtype_t type,
3160 void *arg,
3161 sctp_cmd_seq_t *commands)
3162{
3163 struct sctp_packet *packet = NULL;
3164 struct sctp_chunk *chunk = arg;
3165 struct sctp_chunk *shut;
3166
3167 packet = sctp_ootb_pkt_new(asoc, chunk);
3168
3169 if (packet) {
3170 /* Make an SHUTDOWN_COMPLETE.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003171 * The T bit will be set if the asoc is NULL.
3172 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003173 shut = sctp_make_shutdown_complete(asoc, chunk);
3174 if (!shut) {
3175 sctp_ootb_pkt_free(packet);
3176 return SCTP_DISPOSITION_NOMEM;
3177 }
3178
Jerome Forissier047a2422005-04-28 11:58:43 -07003179 /* Reflect vtag if T-Bit is set */
3180 if (sctp_test_T_bit(shut))
3181 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3182
Linus Torvalds1da177e2005-04-16 15:20:36 -07003183 /* Set the skb to the belonging sock for accounting. */
3184 shut->skb->sk = ep->base.sk;
3185
3186 sctp_packet_append_chunk(packet, shut);
3187
3188 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3189 SCTP_PACKET(packet));
3190
3191 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
3192
3193 /* If the chunk length is invalid, we don't want to process
3194 * the reset of the packet.
3195 */
3196 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3197 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3198
3199 return SCTP_DISPOSITION_CONSUME;
3200 }
3201
3202 return SCTP_DISPOSITION_NOMEM;
3203}
3204
3205/*
3206 * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state.
3207 *
3208 * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK
3209 * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the
3210 * procedures in section 8.4 SHOULD be followed, in other words it
3211 * should be treated as an Out Of The Blue packet.
3212 * [This means that we do NOT check the Verification Tag on these
3213 * chunks. --piggy ]
3214 *
3215 */
3216sctp_disposition_t sctp_sf_do_8_5_1_E_sa(const struct sctp_endpoint *ep,
3217 const struct sctp_association *asoc,
3218 const sctp_subtype_t type,
3219 void *arg,
3220 sctp_cmd_seq_t *commands)
3221{
3222 /* Although we do have an association in this case, it corresponds
3223 * to a restarted association. So the packet is treated as an OOTB
3224 * packet and the state function that handles OOTB SHUTDOWN_ACK is
3225 * called with a NULL association.
3226 */
3227 return sctp_sf_shut_8_4_5(ep, NULL, type, arg, commands);
3228}
3229
3230/* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */
3231sctp_disposition_t sctp_sf_do_asconf(const struct sctp_endpoint *ep,
3232 const struct sctp_association *asoc,
3233 const sctp_subtype_t type, void *arg,
3234 sctp_cmd_seq_t *commands)
3235{
3236 struct sctp_chunk *chunk = arg;
3237 struct sctp_chunk *asconf_ack = NULL;
3238 sctp_addiphdr_t *hdr;
3239 __u32 serial;
3240
3241 if (!sctp_vtag_verify(chunk, asoc)) {
3242 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3243 SCTP_NULL());
3244 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3245 }
3246
3247 /* Make sure that the ASCONF ADDIP chunk has a valid length. */
3248 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_addip_chunk_t)))
3249 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3250 commands);
3251
3252 hdr = (sctp_addiphdr_t *)chunk->skb->data;
3253 serial = ntohl(hdr->serial);
3254
3255 /* ADDIP 4.2 C1) Compare the value of the serial number to the value
3256 * the endpoint stored in a new association variable
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003257 * 'Peer-Serial-Number'.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003258 */
3259 if (serial == asoc->peer.addip_serial + 1) {
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003260 /* ADDIP 4.2 C2) If the value found in the serial number is
Linus Torvalds1da177e2005-04-16 15:20:36 -07003261 * equal to the ('Peer-Serial-Number' + 1), the endpoint MUST
3262 * do V1-V5.
3263 */
3264 asconf_ack = sctp_process_asconf((struct sctp_association *)
3265 asoc, chunk);
3266 if (!asconf_ack)
3267 return SCTP_DISPOSITION_NOMEM;
3268 } else if (serial == asoc->peer.addip_serial) {
3269 /* ADDIP 4.2 C3) If the value found in the serial number is
3270 * equal to the value stored in the 'Peer-Serial-Number'
3271 * IMPLEMENTATION NOTE: As an optimization a receiver may wish
3272 * to save the last ASCONF-ACK for some predetermined period of
3273 * time and instead of re-processing the ASCONF (with the same
3274 * serial number) it may just re-transmit the ASCONF-ACK.
3275 */
3276 if (asoc->addip_last_asconf_ack)
3277 asconf_ack = asoc->addip_last_asconf_ack;
3278 else
3279 return SCTP_DISPOSITION_DISCARD;
3280 } else {
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003281 /* ADDIP 4.2 C4) Otherwise, the ASCONF Chunk is discarded since
Linus Torvalds1da177e2005-04-16 15:20:36 -07003282 * it must be either a stale packet or from an attacker.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003283 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003284 return SCTP_DISPOSITION_DISCARD;
3285 }
3286
3287 /* ADDIP 4.2 C5) In both cases C2 and C3 the ASCONF-ACK MUST be sent
3288 * back to the source address contained in the IP header of the ASCONF
3289 * being responded to.
3290 */
3291 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(asconf_ack));
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003292
Linus Torvalds1da177e2005-04-16 15:20:36 -07003293 return SCTP_DISPOSITION_CONSUME;
3294}
3295
3296/*
3297 * ADDIP Section 4.3 General rules for address manipulation
3298 * When building TLV parameters for the ASCONF Chunk that will add or
3299 * delete IP addresses the D0 to D13 rules should be applied:
3300 */
3301sctp_disposition_t sctp_sf_do_asconf_ack(const struct sctp_endpoint *ep,
3302 const struct sctp_association *asoc,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003303 const sctp_subtype_t type, void *arg,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003304 sctp_cmd_seq_t *commands)
3305{
3306 struct sctp_chunk *asconf_ack = arg;
3307 struct sctp_chunk *last_asconf = asoc->addip_last_asconf;
3308 struct sctp_chunk *abort;
3309 sctp_addiphdr_t *addip_hdr;
3310 __u32 sent_serial, rcvd_serial;
3311
3312 if (!sctp_vtag_verify(asconf_ack, asoc)) {
3313 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3314 SCTP_NULL());
3315 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3316 }
3317
3318 /* Make sure that the ADDIP chunk has a valid length. */
3319 if (!sctp_chunk_length_valid(asconf_ack, sizeof(sctp_addip_chunk_t)))
3320 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3321 commands);
3322
3323 addip_hdr = (sctp_addiphdr_t *)asconf_ack->skb->data;
3324 rcvd_serial = ntohl(addip_hdr->serial);
3325
3326 if (last_asconf) {
3327 addip_hdr = (sctp_addiphdr_t *)last_asconf->subh.addip_hdr;
3328 sent_serial = ntohl(addip_hdr->serial);
3329 } else {
3330 sent_serial = asoc->addip_serial - 1;
3331 }
3332
3333 /* D0) If an endpoint receives an ASCONF-ACK that is greater than or
3334 * equal to the next serial number to be used but no ASCONF chunk is
3335 * outstanding the endpoint MUST ABORT the association. Note that a
3336 * sequence number is greater than if it is no more than 2^^31-1
3337 * larger than the current sequence number (using serial arithmetic).
3338 */
3339 if (ADDIP_SERIAL_gte(rcvd_serial, sent_serial + 1) &&
3340 !(asoc->addip_last_asconf)) {
3341 abort = sctp_make_abort(asoc, asconf_ack,
3342 sizeof(sctp_errhdr_t));
3343 if (abort) {
3344 sctp_init_cause(abort, SCTP_ERROR_ASCONF_ACK, NULL, 0);
3345 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3346 SCTP_CHUNK(abort));
3347 }
3348 /* We are going to ABORT, so we might as well stop
3349 * processing the rest of the chunks in the packet.
3350 */
3351 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3352 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3353 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07003354 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003355 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003356 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08003357 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003358 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
3359 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3360 return SCTP_DISPOSITION_ABORT;
3361 }
3362
3363 if ((rcvd_serial == sent_serial) && asoc->addip_last_asconf) {
3364 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3365 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3366
3367 if (!sctp_process_asconf_ack((struct sctp_association *)asoc,
3368 asconf_ack))
3369 return SCTP_DISPOSITION_CONSUME;
3370
3371 abort = sctp_make_abort(asoc, asconf_ack,
3372 sizeof(sctp_errhdr_t));
3373 if (abort) {
3374 sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, NULL, 0);
3375 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3376 SCTP_CHUNK(abort));
3377 }
3378 /* We are going to ABORT, so we might as well stop
3379 * processing the rest of the chunks in the packet.
3380 */
3381 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07003382 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003383 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003384 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08003385 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003386 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
3387 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3388 return SCTP_DISPOSITION_ABORT;
3389 }
3390
3391 return SCTP_DISPOSITION_DISCARD;
3392}
3393
3394/*
3395 * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP
3396 *
3397 * When a FORWARD TSN chunk arrives, the data receiver MUST first update
3398 * its cumulative TSN point to the value carried in the FORWARD TSN
3399 * chunk, and then MUST further advance its cumulative TSN point locally
3400 * if possible.
3401 * After the above processing, the data receiver MUST stop reporting any
3402 * missing TSNs earlier than or equal to the new cumulative TSN point.
3403 *
3404 * Verification Tag: 8.5 Verification Tag [Normal verification]
3405 *
3406 * The return value is the disposition of the chunk.
3407 */
3408sctp_disposition_t sctp_sf_eat_fwd_tsn(const struct sctp_endpoint *ep,
3409 const struct sctp_association *asoc,
3410 const sctp_subtype_t type,
3411 void *arg,
3412 sctp_cmd_seq_t *commands)
3413{
3414 struct sctp_chunk *chunk = arg;
3415 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
3416 __u16 len;
3417 __u32 tsn;
3418
3419 if (!sctp_vtag_verify(chunk, asoc)) {
3420 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3421 SCTP_NULL());
3422 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3423 }
3424
3425 /* Make sure that the FORWARD_TSN chunk has valid length. */
3426 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
3427 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3428 commands);
3429
3430 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3431 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3432 len = ntohs(chunk->chunk_hdr->length);
3433 len -= sizeof(struct sctp_chunkhdr);
3434 skb_pull(chunk->skb, len);
3435
3436 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
3437 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __FUNCTION__, tsn);
3438
3439 /* The TSN is too high--silently discard the chunk and count on it
3440 * getting retransmitted later.
3441 */
3442 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3443 goto discard_noforce;
3444
3445 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3446 if (len > sizeof(struct sctp_fwdtsn_hdr))
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003447 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003448 SCTP_CHUNK(chunk));
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003449
Linus Torvalds1da177e2005-04-16 15:20:36 -07003450 /* Count this as receiving DATA. */
3451 if (asoc->autoclose) {
3452 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3453 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
3454 }
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003455
Linus Torvalds1da177e2005-04-16 15:20:36 -07003456 /* FIXME: For now send a SACK, but DATA processing may
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003457 * send another.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003458 */
3459 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
Linus Torvalds1da177e2005-04-16 15:20:36 -07003460
3461 return SCTP_DISPOSITION_CONSUME;
3462
3463discard_noforce:
3464 return SCTP_DISPOSITION_DISCARD;
3465}
3466
3467sctp_disposition_t sctp_sf_eat_fwd_tsn_fast(
3468 const struct sctp_endpoint *ep,
3469 const struct sctp_association *asoc,
3470 const sctp_subtype_t type,
3471 void *arg,
3472 sctp_cmd_seq_t *commands)
3473{
3474 struct sctp_chunk *chunk = arg;
3475 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
3476 __u16 len;
3477 __u32 tsn;
3478
3479 if (!sctp_vtag_verify(chunk, asoc)) {
3480 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3481 SCTP_NULL());
3482 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3483 }
3484
3485 /* Make sure that the FORWARD_TSN chunk has a valid length. */
3486 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
3487 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3488 commands);
3489
3490 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3491 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3492 len = ntohs(chunk->chunk_hdr->length);
3493 len -= sizeof(struct sctp_chunkhdr);
3494 skb_pull(chunk->skb, len);
3495
3496 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
3497 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __FUNCTION__, tsn);
3498
3499 /* The TSN is too high--silently discard the chunk and count on it
3500 * getting retransmitted later.
3501 */
3502 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3503 goto gen_shutdown;
3504
3505 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3506 if (len > sizeof(struct sctp_fwdtsn_hdr))
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003507 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003508 SCTP_CHUNK(chunk));
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003509
Linus Torvalds1da177e2005-04-16 15:20:36 -07003510 /* Go a head and force a SACK, since we are shutting down. */
3511gen_shutdown:
3512 /* Implementor's Guide.
3513 *
3514 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3515 * respond to each received packet containing one or more DATA chunk(s)
3516 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3517 */
3518 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
3519 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3520 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3521 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3522
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003523 return SCTP_DISPOSITION_CONSUME;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003524}
3525
3526/*
3527 * Process an unknown chunk.
3528 *
3529 * Section: 3.2. Also, 2.1 in the implementor's guide.
3530 *
3531 * Chunk Types are encoded such that the highest-order two bits specify
3532 * the action that must be taken if the processing endpoint does not
3533 * recognize the Chunk Type.
3534 *
3535 * 00 - Stop processing this SCTP packet and discard it, do not process
3536 * any further chunks within it.
3537 *
3538 * 01 - Stop processing this SCTP packet and discard it, do not process
3539 * any further chunks within it, and report the unrecognized
3540 * chunk in an 'Unrecognized Chunk Type'.
3541 *
3542 * 10 - Skip this chunk and continue processing.
3543 *
3544 * 11 - Skip this chunk and continue processing, but report in an ERROR
3545 * Chunk using the 'Unrecognized Chunk Type' cause of error.
3546 *
3547 * The return value is the disposition of the chunk.
3548 */
3549sctp_disposition_t sctp_sf_unk_chunk(const struct sctp_endpoint *ep,
3550 const struct sctp_association *asoc,
3551 const sctp_subtype_t type,
3552 void *arg,
3553 sctp_cmd_seq_t *commands)
3554{
3555 struct sctp_chunk *unk_chunk = arg;
3556 struct sctp_chunk *err_chunk;
3557 sctp_chunkhdr_t *hdr;
3558
3559 SCTP_DEBUG_PRINTK("Processing the unknown chunk id %d.\n", type.chunk);
3560
3561 if (!sctp_vtag_verify(unk_chunk, asoc))
3562 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3563
3564 /* Make sure that the chunk has a valid length.
3565 * Since we don't know the chunk type, we use a general
3566 * chunkhdr structure to make a comparison.
3567 */
3568 if (!sctp_chunk_length_valid(unk_chunk, sizeof(sctp_chunkhdr_t)))
3569 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3570 commands);
3571
3572 switch (type.chunk & SCTP_CID_ACTION_MASK) {
3573 case SCTP_CID_ACTION_DISCARD:
3574 /* Discard the packet. */
3575 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3576 break;
3577 case SCTP_CID_ACTION_DISCARD_ERR:
3578 /* Discard the packet. */
3579 sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3580
3581 /* Generate an ERROR chunk as response. */
3582 hdr = unk_chunk->chunk_hdr;
3583 err_chunk = sctp_make_op_error(asoc, unk_chunk,
3584 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
3585 WORD_ROUND(ntohs(hdr->length)));
3586 if (err_chunk) {
3587 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3588 SCTP_CHUNK(err_chunk));
3589 }
3590 return SCTP_DISPOSITION_CONSUME;
3591 break;
3592 case SCTP_CID_ACTION_SKIP:
3593 /* Skip the chunk. */
3594 return SCTP_DISPOSITION_DISCARD;
3595 break;
3596 case SCTP_CID_ACTION_SKIP_ERR:
3597 /* Generate an ERROR chunk as response. */
3598 hdr = unk_chunk->chunk_hdr;
3599 err_chunk = sctp_make_op_error(asoc, unk_chunk,
3600 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
3601 WORD_ROUND(ntohs(hdr->length)));
3602 if (err_chunk) {
3603 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3604 SCTP_CHUNK(err_chunk));
3605 }
3606 /* Skip the chunk. */
3607 return SCTP_DISPOSITION_CONSUME;
3608 break;
3609 default:
3610 break;
3611 }
3612
3613 return SCTP_DISPOSITION_DISCARD;
3614}
3615
3616/*
3617 * Discard the chunk.
3618 *
3619 * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2
3620 * [Too numerous to mention...]
3621 * Verification Tag: No verification needed.
3622 * Inputs
3623 * (endpoint, asoc, chunk)
3624 *
3625 * Outputs
3626 * (asoc, reply_msg, msg_up, timers, counters)
3627 *
3628 * The return value is the disposition of the chunk.
3629 */
3630sctp_disposition_t sctp_sf_discard_chunk(const struct sctp_endpoint *ep,
3631 const struct sctp_association *asoc,
3632 const sctp_subtype_t type,
3633 void *arg,
3634 sctp_cmd_seq_t *commands)
3635{
3636 SCTP_DEBUG_PRINTK("Chunk %d is discarded\n", type.chunk);
3637 return SCTP_DISPOSITION_DISCARD;
3638}
3639
3640/*
3641 * Discard the whole packet.
3642 *
3643 * Section: 8.4 2)
3644 *
3645 * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST
3646 * silently discard the OOTB packet and take no further action.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003647 *
3648 * Verification Tag: No verification necessary
3649 *
3650 * Inputs
3651 * (endpoint, asoc, chunk)
3652 *
3653 * Outputs
3654 * (asoc, reply_msg, msg_up, timers, counters)
3655 *
3656 * The return value is the disposition of the chunk.
3657 */
3658sctp_disposition_t sctp_sf_pdiscard(const struct sctp_endpoint *ep,
3659 const struct sctp_association *asoc,
3660 const sctp_subtype_t type,
3661 void *arg,
3662 sctp_cmd_seq_t *commands)
3663{
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07003664 SCTP_INC_STATS(SCTP_MIB_IN_PKT_DISCARDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003665 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
3666
3667 return SCTP_DISPOSITION_CONSUME;
3668}
3669
3670
3671/*
3672 * The other end is violating protocol.
3673 *
3674 * Section: Not specified
3675 * Verification Tag: Not specified
3676 * Inputs
3677 * (endpoint, asoc, chunk)
3678 *
3679 * Outputs
3680 * (asoc, reply_msg, msg_up, timers, counters)
3681 *
3682 * We simply tag the chunk as a violation. The state machine will log
3683 * the violation and continue.
3684 */
3685sctp_disposition_t sctp_sf_violation(const struct sctp_endpoint *ep,
3686 const struct sctp_association *asoc,
3687 const sctp_subtype_t type,
3688 void *arg,
3689 sctp_cmd_seq_t *commands)
3690{
3691 return SCTP_DISPOSITION_VIOLATION;
3692}
3693
3694
3695/*
3696 * Handle a protocol violation when the chunk length is invalid.
3697 * "Invalid" length is identified as smaller then the minimal length a
3698 * given chunk can be. For example, a SACK chunk has invalid length
3699 * if it's length is set to be smaller then the size of sctp_sack_chunk_t.
3700 *
3701 * We inform the other end by sending an ABORT with a Protocol Violation
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003702 * error code.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003703 *
3704 * Section: Not specified
3705 * Verification Tag: Nothing to do
3706 * Inputs
3707 * (endpoint, asoc, chunk)
3708 *
3709 * Outputs
3710 * (reply_msg, msg_up, counters)
3711 *
3712 * Generate an ABORT chunk and terminate the association.
3713 */
Adrian Bunk52c1da32005-06-23 22:05:33 -07003714static sctp_disposition_t sctp_sf_violation_chunklen(
3715 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003716 const struct sctp_association *asoc,
3717 const sctp_subtype_t type,
3718 void *arg,
3719 sctp_cmd_seq_t *commands)
3720{
3721 struct sctp_chunk *chunk = arg;
3722 struct sctp_chunk *abort = NULL;
3723 char err_str[]="The following chunk had invalid length:";
3724
3725 /* Make the abort chunk. */
3726 abort = sctp_make_abort_violation(asoc, chunk, err_str,
3727 sizeof(err_str));
3728 if (!abort)
3729 goto nomem;
3730
3731 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
3732 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
3733
3734 if (asoc->state <= SCTP_STATE_COOKIE_ECHOED) {
3735 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3736 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07003737 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
3738 SCTP_ERROR(ECONNREFUSED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003739 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08003740 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003741 } else {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07003742 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003743 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003744 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08003745 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003746 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3747 }
3748
3749 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
3750
3751 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09003752
Linus Torvalds1da177e2005-04-16 15:20:36 -07003753 return SCTP_DISPOSITION_ABORT;
3754
3755nomem:
3756 return SCTP_DISPOSITION_NOMEM;
3757}
3758
3759/***************************************************************************
3760 * These are the state functions for handling primitive (Section 10) events.
3761 ***************************************************************************/
3762/*
3763 * sctp_sf_do_prm_asoc
3764 *
3765 * Section: 10.1 ULP-to-SCTP
3766 * B) Associate
3767 *
3768 * Format: ASSOCIATE(local SCTP instance name, destination transport addr,
3769 * outbound stream count)
3770 * -> association id [,destination transport addr list] [,outbound stream
3771 * count]
3772 *
3773 * This primitive allows the upper layer to initiate an association to a
3774 * specific peer endpoint.
3775 *
3776 * The peer endpoint shall be specified by one of the transport addresses
3777 * which defines the endpoint (see Section 1.4). If the local SCTP
3778 * instance has not been initialized, the ASSOCIATE is considered an
3779 * error.
3780 * [This is not relevant for the kernel implementation since we do all
3781 * initialization at boot time. It we hadn't initialized we wouldn't
3782 * get anywhere near this code.]
3783 *
3784 * An association id, which is a local handle to the SCTP association,
3785 * will be returned on successful establishment of the association. If
3786 * SCTP is not able to open an SCTP association with the peer endpoint,
3787 * an error is returned.
3788 * [In the kernel implementation, the struct sctp_association needs to
3789 * be created BEFORE causing this primitive to run.]
3790 *
3791 * Other association parameters may be returned, including the
3792 * complete destination transport addresses of the peer as well as the
3793 * outbound stream count of the local endpoint. One of the transport
3794 * address from the returned destination addresses will be selected by
3795 * the local endpoint as default primary path for sending SCTP packets
3796 * to this peer. The returned "destination transport addr list" can
3797 * be used by the ULP to change the default primary path or to force
3798 * sending a packet to a specific transport address. [All of this
3799 * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING
3800 * function.]
3801 *
3802 * Mandatory attributes:
3803 *
3804 * o local SCTP instance name - obtained from the INITIALIZE operation.
3805 * [This is the argument asoc.]
3806 * o destination transport addr - specified as one of the transport
3807 * addresses of the peer endpoint with which the association is to be
3808 * established.
3809 * [This is asoc->peer.active_path.]
3810 * o outbound stream count - the number of outbound streams the ULP
3811 * would like to open towards this peer endpoint.
3812 * [BUG: This is not currently implemented.]
3813 * Optional attributes:
3814 *
3815 * None.
3816 *
3817 * The return value is a disposition.
3818 */
3819sctp_disposition_t sctp_sf_do_prm_asoc(const struct sctp_endpoint *ep,
3820 const struct sctp_association *asoc,
3821 const sctp_subtype_t type,
3822 void *arg,
3823 sctp_cmd_seq_t *commands)
3824{
3825 struct sctp_chunk *repl;
3826
3827 /* The comment below says that we enter COOKIE-WAIT AFTER
3828 * sending the INIT, but that doesn't actually work in our
3829 * implementation...
3830 */
3831 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3832 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
3833
3834 /* RFC 2960 5.1 Normal Establishment of an Association
3835 *
3836 * A) "A" first sends an INIT chunk to "Z". In the INIT, "A"
3837 * must provide its Verification Tag (Tag_A) in the Initiate
3838 * Tag field. Tag_A SHOULD be a random number in the range of
3839 * 1 to 4294967295 (see 5.3.1 for Tag value selection). ...
3840 */
3841
3842 repl = sctp_make_init(asoc, &asoc->base.bind_addr, GFP_ATOMIC, 0);
3843 if (!repl)
3844 goto nomem;
3845
3846 /* Cast away the const modifier, as we want to just
3847 * rerun it through as a sideffect.
3848 */
3849 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC,
3850 SCTP_ASOC((struct sctp_association *) asoc));
3851
Frank Filz3f7a87d2005-06-20 13:14:57 -07003852 /* Choose transport for INIT. */
3853 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
3854 SCTP_CHUNK(repl));
3855
Linus Torvalds1da177e2005-04-16 15:20:36 -07003856 /* After sending the INIT, "A" starts the T1-init timer and
3857 * enters the COOKIE-WAIT state.
3858 */
3859 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
3860 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
3861 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
3862 return SCTP_DISPOSITION_CONSUME;
3863
3864nomem:
3865 return SCTP_DISPOSITION_NOMEM;
3866}
3867
3868/*
3869 * Process the SEND primitive.
3870 *
3871 * Section: 10.1 ULP-to-SCTP
3872 * E) Send
3873 *
3874 * Format: SEND(association id, buffer address, byte count [,context]
3875 * [,stream id] [,life time] [,destination transport address]
3876 * [,unorder flag] [,no-bundle flag] [,payload protocol-id] )
3877 * -> result
3878 *
3879 * This is the main method to send user data via SCTP.
3880 *
3881 * Mandatory attributes:
3882 *
3883 * o association id - local handle to the SCTP association
3884 *
3885 * o buffer address - the location where the user message to be
3886 * transmitted is stored;
3887 *
3888 * o byte count - The size of the user data in number of bytes;
3889 *
3890 * Optional attributes:
3891 *
3892 * o context - an optional 32 bit integer that will be carried in the
3893 * sending failure notification to the ULP if the transportation of
3894 * this User Message fails.
3895 *
3896 * o stream id - to indicate which stream to send the data on. If not
3897 * specified, stream 0 will be used.
3898 *
3899 * o life time - specifies the life time of the user data. The user data
3900 * will not be sent by SCTP after the life time expires. This
3901 * parameter can be used to avoid efforts to transmit stale
3902 * user messages. SCTP notifies the ULP if the data cannot be
3903 * initiated to transport (i.e. sent to the destination via SCTP's
3904 * send primitive) within the life time variable. However, the
3905 * user data will be transmitted if SCTP has attempted to transmit a
3906 * chunk before the life time expired.
3907 *
3908 * o destination transport address - specified as one of the destination
3909 * transport addresses of the peer endpoint to which this packet
3910 * should be sent. Whenever possible, SCTP should use this destination
3911 * transport address for sending the packets, instead of the current
3912 * primary path.
3913 *
3914 * o unorder flag - this flag, if present, indicates that the user
3915 * would like the data delivered in an unordered fashion to the peer
3916 * (i.e., the U flag is set to 1 on all DATA chunks carrying this
3917 * message).
3918 *
3919 * o no-bundle flag - instructs SCTP not to bundle this user data with
3920 * other outbound DATA chunks. SCTP MAY still bundle even when
3921 * this flag is present, when faced with network congestion.
3922 *
3923 * o payload protocol-id - A 32 bit unsigned integer that is to be
3924 * passed to the peer indicating the type of payload protocol data
3925 * being transmitted. This value is passed as opaque data by SCTP.
3926 *
3927 * The return value is the disposition.
3928 */
3929sctp_disposition_t sctp_sf_do_prm_send(const struct sctp_endpoint *ep,
3930 const struct sctp_association *asoc,
3931 const sctp_subtype_t type,
3932 void *arg,
3933 sctp_cmd_seq_t *commands)
3934{
3935 struct sctp_chunk *chunk = arg;
3936
3937 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
3938 return SCTP_DISPOSITION_CONSUME;
3939}
3940
3941/*
3942 * Process the SHUTDOWN primitive.
3943 *
3944 * Section: 10.1:
3945 * C) Shutdown
3946 *
3947 * Format: SHUTDOWN(association id)
3948 * -> result
3949 *
3950 * Gracefully closes an association. Any locally queued user data
3951 * will be delivered to the peer. The association will be terminated only
3952 * after the peer acknowledges all the SCTP packets sent. A success code
3953 * will be returned on successful termination of the association. If
3954 * attempting to terminate the association results in a failure, an error
3955 * code shall be returned.
3956 *
3957 * Mandatory attributes:
3958 *
3959 * o association id - local handle to the SCTP association
3960 *
3961 * Optional attributes:
3962 *
3963 * None.
3964 *
3965 * The return value is the disposition.
3966 */
3967sctp_disposition_t sctp_sf_do_9_2_prm_shutdown(
3968 const struct sctp_endpoint *ep,
3969 const struct sctp_association *asoc,
3970 const sctp_subtype_t type,
3971 void *arg,
3972 sctp_cmd_seq_t *commands)
3973{
3974 int disposition;
3975
3976 /* From 9.2 Shutdown of an Association
3977 * Upon receipt of the SHUTDOWN primitive from its upper
3978 * layer, the endpoint enters SHUTDOWN-PENDING state and
3979 * remains there until all outstanding data has been
3980 * acknowledged by its peer. The endpoint accepts no new data
3981 * from its upper layer, but retransmits data to the far end
3982 * if necessary to fill gaps.
3983 */
3984 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3985 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
3986
3987 /* sctpimpguide-05 Section 2.12.2
3988 * The sender of the SHUTDOWN MAY also start an overall guard timer
3989 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
3990 */
3991 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
3992 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
3993
3994 disposition = SCTP_DISPOSITION_CONSUME;
3995 if (sctp_outq_is_empty(&asoc->outqueue)) {
3996 disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type,
3997 arg, commands);
3998 }
3999 return disposition;
4000}
4001
4002/*
4003 * Process the ABORT primitive.
4004 *
4005 * Section: 10.1:
4006 * C) Abort
4007 *
4008 * Format: Abort(association id [, cause code])
4009 * -> result
4010 *
4011 * Ungracefully closes an association. Any locally queued user data
4012 * will be discarded and an ABORT chunk is sent to the peer. A success code
4013 * will be returned on successful abortion of the association. If
4014 * attempting to abort the association results in a failure, an error
4015 * code shall be returned.
4016 *
4017 * Mandatory attributes:
4018 *
4019 * o association id - local handle to the SCTP association
4020 *
4021 * Optional attributes:
4022 *
4023 * o cause code - reason of the abort to be passed to the peer
4024 *
4025 * None.
4026 *
4027 * The return value is the disposition.
4028 */
4029sctp_disposition_t sctp_sf_do_9_1_prm_abort(
4030 const struct sctp_endpoint *ep,
4031 const struct sctp_association *asoc,
4032 const sctp_subtype_t type,
4033 void *arg,
4034 sctp_cmd_seq_t *commands)
4035{
4036 /* From 9.1 Abort of an Association
4037 * Upon receipt of the ABORT primitive from its upper
4038 * layer, the endpoint enters CLOSED state and
4039 * discard all outstanding data has been
4040 * acknowledged by its peer. The endpoint accepts no new data
4041 * from its upper layer, but retransmits data to the far end
4042 * if necessary to fill gaps.
4043 */
Sridhar Samudralac164a9b2006-08-22 11:50:39 -07004044 struct sctp_chunk *abort = arg;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004045 sctp_disposition_t retval;
4046
4047 retval = SCTP_DISPOSITION_CONSUME;
4048
Sridhar Samudralac164a9b2006-08-22 11:50:39 -07004049 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004050
4051 /* Even if we can't send the ABORT due to low memory delete the
4052 * TCB. This is a departure from our typical NOMEM handling.
4053 */
4054
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004055 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4056 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004057 /* Delete the established association. */
4058 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08004059 SCTP_PERR(SCTP_ERROR_USER_ABORT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004060
4061 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4062 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
4063
4064 return retval;
4065}
4066
4067/* We tried an illegal operation on an association which is closed. */
4068sctp_disposition_t sctp_sf_error_closed(const struct sctp_endpoint *ep,
4069 const struct sctp_association *asoc,
4070 const sctp_subtype_t type,
4071 void *arg,
4072 sctp_cmd_seq_t *commands)
4073{
4074 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, SCTP_ERROR(-EINVAL));
4075 return SCTP_DISPOSITION_CONSUME;
4076}
4077
4078/* We tried an illegal operation on an association which is shutting
4079 * down.
4080 */
4081sctp_disposition_t sctp_sf_error_shutdown(const struct sctp_endpoint *ep,
4082 const struct sctp_association *asoc,
4083 const sctp_subtype_t type,
4084 void *arg,
4085 sctp_cmd_seq_t *commands)
4086{
4087 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR,
4088 SCTP_ERROR(-ESHUTDOWN));
4089 return SCTP_DISPOSITION_CONSUME;
4090}
4091
4092/*
4093 * sctp_cookie_wait_prm_shutdown
4094 *
4095 * Section: 4 Note: 2
4096 * Verification Tag:
4097 * Inputs
4098 * (endpoint, asoc)
4099 *
4100 * The RFC does not explicitly address this issue, but is the route through the
4101 * state table when someone issues a shutdown while in COOKIE_WAIT state.
4102 *
4103 * Outputs
4104 * (timers)
4105 */
4106sctp_disposition_t sctp_sf_cookie_wait_prm_shutdown(
4107 const struct sctp_endpoint *ep,
4108 const struct sctp_association *asoc,
4109 const sctp_subtype_t type,
4110 void *arg,
4111 sctp_cmd_seq_t *commands)
4112{
4113 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4114 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4115
4116 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4117 SCTP_STATE(SCTP_STATE_CLOSED));
4118
4119 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
4120
4121 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
4122
4123 return SCTP_DISPOSITION_DELETE_TCB;
4124}
4125
4126/*
4127 * sctp_cookie_echoed_prm_shutdown
4128 *
4129 * Section: 4 Note: 2
4130 * Verification Tag:
4131 * Inputs
4132 * (endpoint, asoc)
4133 *
4134 * The RFC does not explcitly address this issue, but is the route through the
4135 * state table when someone issues a shutdown while in COOKIE_ECHOED state.
4136 *
4137 * Outputs
4138 * (timers)
4139 */
4140sctp_disposition_t sctp_sf_cookie_echoed_prm_shutdown(
4141 const struct sctp_endpoint *ep,
4142 const struct sctp_association *asoc,
4143 const sctp_subtype_t type,
4144 void *arg, sctp_cmd_seq_t *commands)
4145{
4146 /* There is a single T1 timer, so we should be able to use
4147 * common function with the COOKIE-WAIT state.
4148 */
4149 return sctp_sf_cookie_wait_prm_shutdown(ep, asoc, type, arg, commands);
4150}
4151
4152/*
4153 * sctp_sf_cookie_wait_prm_abort
4154 *
4155 * Section: 4 Note: 2
4156 * Verification Tag:
4157 * Inputs
4158 * (endpoint, asoc)
4159 *
4160 * The RFC does not explicitly address this issue, but is the route through the
4161 * state table when someone issues an abort while in COOKIE_WAIT state.
4162 *
4163 * Outputs
4164 * (timers)
4165 */
4166sctp_disposition_t sctp_sf_cookie_wait_prm_abort(
4167 const struct sctp_endpoint *ep,
4168 const struct sctp_association *asoc,
4169 const sctp_subtype_t type,
4170 void *arg,
4171 sctp_cmd_seq_t *commands)
4172{
Sridhar Samudralac164a9b2006-08-22 11:50:39 -07004173 struct sctp_chunk *abort = arg;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004174 sctp_disposition_t retval;
4175
4176 /* Stop T1-init timer */
4177 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4178 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4179 retval = SCTP_DISPOSITION_CONSUME;
4180
Sridhar Samudralac164a9b2006-08-22 11:50:39 -07004181 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004182
4183 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4184 SCTP_STATE(SCTP_STATE_CLOSED));
4185
4186 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4187
4188 /* Even if we can't send the ABORT due to low memory delete the
4189 * TCB. This is a departure from our typical NOMEM handling.
4190 */
4191
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004192 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4193 SCTP_ERROR(ECONNREFUSED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004194 /* Delete the established association. */
4195 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08004196 SCTP_PERR(SCTP_ERROR_USER_ABORT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004197
4198 return retval;
4199}
4200
4201/*
4202 * sctp_sf_cookie_echoed_prm_abort
4203 *
4204 * Section: 4 Note: 3
4205 * Verification Tag:
4206 * Inputs
4207 * (endpoint, asoc)
4208 *
4209 * The RFC does not explcitly address this issue, but is the route through the
4210 * state table when someone issues an abort while in COOKIE_ECHOED state.
4211 *
4212 * Outputs
4213 * (timers)
4214 */
4215sctp_disposition_t sctp_sf_cookie_echoed_prm_abort(
4216 const struct sctp_endpoint *ep,
4217 const struct sctp_association *asoc,
4218 const sctp_subtype_t type,
4219 void *arg,
4220 sctp_cmd_seq_t *commands)
4221{
4222 /* There is a single T1 timer, so we should be able to use
4223 * common function with the COOKIE-WAIT state.
4224 */
4225 return sctp_sf_cookie_wait_prm_abort(ep, asoc, type, arg, commands);
4226}
4227
4228/*
4229 * sctp_sf_shutdown_pending_prm_abort
4230 *
4231 * Inputs
4232 * (endpoint, asoc)
4233 *
4234 * The RFC does not explicitly address this issue, but is the route through the
4235 * state table when someone issues an abort while in SHUTDOWN-PENDING state.
4236 *
4237 * Outputs
4238 * (timers)
4239 */
4240sctp_disposition_t sctp_sf_shutdown_pending_prm_abort(
4241 const struct sctp_endpoint *ep,
4242 const struct sctp_association *asoc,
4243 const sctp_subtype_t type,
4244 void *arg,
4245 sctp_cmd_seq_t *commands)
4246{
4247 /* Stop the T5-shutdown guard timer. */
4248 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4249 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4250
4251 return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands);
4252}
4253
4254/*
4255 * sctp_sf_shutdown_sent_prm_abort
4256 *
4257 * Inputs
4258 * (endpoint, asoc)
4259 *
4260 * The RFC does not explicitly address this issue, but is the route through the
4261 * state table when someone issues an abort while in SHUTDOWN-SENT state.
4262 *
4263 * Outputs
4264 * (timers)
4265 */
4266sctp_disposition_t sctp_sf_shutdown_sent_prm_abort(
4267 const struct sctp_endpoint *ep,
4268 const struct sctp_association *asoc,
4269 const sctp_subtype_t type,
4270 void *arg,
4271 sctp_cmd_seq_t *commands)
4272{
4273 /* Stop the T2-shutdown timer. */
4274 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4275 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4276
4277 /* Stop the T5-shutdown guard timer. */
4278 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4279 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4280
4281 return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands);
4282}
4283
4284/*
4285 * sctp_sf_cookie_echoed_prm_abort
4286 *
4287 * Inputs
4288 * (endpoint, asoc)
4289 *
4290 * The RFC does not explcitly address this issue, but is the route through the
4291 * state table when someone issues an abort while in COOKIE_ECHOED state.
4292 *
4293 * Outputs
4294 * (timers)
4295 */
4296sctp_disposition_t sctp_sf_shutdown_ack_sent_prm_abort(
4297 const struct sctp_endpoint *ep,
4298 const struct sctp_association *asoc,
4299 const sctp_subtype_t type,
4300 void *arg,
4301 sctp_cmd_seq_t *commands)
4302{
4303 /* The same T2 timer, so we should be able to use
4304 * common function with the SHUTDOWN-SENT state.
4305 */
4306 return sctp_sf_shutdown_sent_prm_abort(ep, asoc, type, arg, commands);
4307}
4308
4309/*
4310 * Process the REQUESTHEARTBEAT primitive
4311 *
4312 * 10.1 ULP-to-SCTP
4313 * J) Request Heartbeat
4314 *
4315 * Format: REQUESTHEARTBEAT(association id, destination transport address)
4316 *
4317 * -> result
4318 *
4319 * Instructs the local endpoint to perform a HeartBeat on the specified
4320 * destination transport address of the given association. The returned
4321 * result should indicate whether the transmission of the HEARTBEAT
4322 * chunk to the destination address is successful.
4323 *
4324 * Mandatory attributes:
4325 *
4326 * o association id - local handle to the SCTP association
4327 *
4328 * o destination transport address - the transport address of the
4329 * association on which a heartbeat should be issued.
4330 */
4331sctp_disposition_t sctp_sf_do_prm_requestheartbeat(
4332 const struct sctp_endpoint *ep,
4333 const struct sctp_association *asoc,
4334 const sctp_subtype_t type,
4335 void *arg,
4336 sctp_cmd_seq_t *commands)
4337{
Vlad Yasevichfb785252007-03-19 17:02:03 -07004338 if (SCTP_DISPOSITION_NOMEM == sctp_sf_heartbeat(ep, asoc, type,
4339 (struct sctp_transport *)arg, commands))
4340 return SCTP_DISPOSITION_NOMEM;
4341
4342 /*
4343 * RFC 2960 (bis), section 8.3
4344 *
4345 * D) Request an on-demand HEARTBEAT on a specific destination
4346 * transport address of a given association.
4347 *
4348 * The endpoint should increment the respective error counter of
4349 * the destination transport address each time a HEARTBEAT is sent
4350 * to that address and not acknowledged within one RTO.
4351 *
4352 */
4353 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_RESET,
4354 SCTP_TRANSPORT(arg));
4355 return SCTP_DISPOSITION_CONSUME;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004356}
4357
4358/*
4359 * ADDIP Section 4.1 ASCONF Chunk Procedures
4360 * When an endpoint has an ASCONF signaled change to be sent to the
4361 * remote endpoint it should do A1 to A9
4362 */
4363sctp_disposition_t sctp_sf_do_prm_asconf(const struct sctp_endpoint *ep,
4364 const struct sctp_association *asoc,
4365 const sctp_subtype_t type,
4366 void *arg,
4367 sctp_cmd_seq_t *commands)
4368{
4369 struct sctp_chunk *chunk = arg;
4370
4371 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
4372 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4373 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
4374 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
4375 return SCTP_DISPOSITION_CONSUME;
4376}
4377
4378/*
4379 * Ignore the primitive event
4380 *
4381 * The return value is the disposition of the primitive.
4382 */
4383sctp_disposition_t sctp_sf_ignore_primitive(
4384 const struct sctp_endpoint *ep,
4385 const struct sctp_association *asoc,
4386 const sctp_subtype_t type,
4387 void *arg,
4388 sctp_cmd_seq_t *commands)
4389{
4390 SCTP_DEBUG_PRINTK("Primitive type %d is ignored.\n", type.primitive);
4391 return SCTP_DISPOSITION_DISCARD;
4392}
4393
4394/***************************************************************************
4395 * These are the state functions for the OTHER events.
4396 ***************************************************************************/
4397
4398/*
4399 * Start the shutdown negotiation.
4400 *
4401 * From Section 9.2:
4402 * Once all its outstanding data has been acknowledged, the endpoint
4403 * shall send a SHUTDOWN chunk to its peer including in the Cumulative
4404 * TSN Ack field the last sequential TSN it has received from the peer.
4405 * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT
4406 * state. If the timer expires, the endpoint must re-send the SHUTDOWN
4407 * with the updated last sequential TSN received from its peer.
4408 *
4409 * The return value is the disposition.
4410 */
4411sctp_disposition_t sctp_sf_do_9_2_start_shutdown(
4412 const struct sctp_endpoint *ep,
4413 const struct sctp_association *asoc,
4414 const sctp_subtype_t type,
4415 void *arg,
4416 sctp_cmd_seq_t *commands)
4417{
4418 struct sctp_chunk *reply;
4419
4420 /* Once all its outstanding data has been acknowledged, the
4421 * endpoint shall send a SHUTDOWN chunk to its peer including
4422 * in the Cumulative TSN Ack field the last sequential TSN it
4423 * has received from the peer.
4424 */
4425 reply = sctp_make_shutdown(asoc, NULL);
4426 if (!reply)
4427 goto nomem;
4428
4429 /* Set the transport for the SHUTDOWN chunk and the timeout for the
4430 * T2-shutdown timer.
4431 */
4432 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
4433
4434 /* It shall then start the T2-shutdown timer */
4435 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4436 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4437
4438 if (asoc->autoclose)
4439 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4440 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
4441
4442 /* and enter the SHUTDOWN-SENT state. */
4443 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4444 SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT));
4445
4446 /* sctp-implguide 2.10 Issues with Heartbeating and failover
4447 *
4448 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09004449 * or SHUTDOWN-ACK.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004450 */
4451 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
4452
4453 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
4454
4455 return SCTP_DISPOSITION_CONSUME;
4456
4457nomem:
4458 return SCTP_DISPOSITION_NOMEM;
4459}
4460
4461/*
4462 * Generate a SHUTDOWN ACK now that everything is SACK'd.
4463 *
4464 * From Section 9.2:
4465 *
4466 * If it has no more outstanding DATA chunks, the SHUTDOWN receiver
4467 * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own,
4468 * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the
4469 * endpoint must re-send the SHUTDOWN ACK.
4470 *
4471 * The return value is the disposition.
4472 */
4473sctp_disposition_t sctp_sf_do_9_2_shutdown_ack(
4474 const struct sctp_endpoint *ep,
4475 const struct sctp_association *asoc,
4476 const sctp_subtype_t type,
4477 void *arg,
4478 sctp_cmd_seq_t *commands)
4479{
4480 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
4481 struct sctp_chunk *reply;
4482
4483 /* There are 2 ways of getting here:
4484 * 1) called in response to a SHUTDOWN chunk
4485 * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued.
4486 *
4487 * For the case (2), the arg parameter is set to NULL. We need
4488 * to check that we have a chunk before accessing it's fields.
4489 */
4490 if (chunk) {
4491 if (!sctp_vtag_verify(chunk, asoc))
4492 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
4493
4494 /* Make sure that the SHUTDOWN chunk has a valid length. */
4495 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_shutdown_chunk_t)))
4496 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
4497 commands);
4498 }
4499
4500 /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
4501 * shall send a SHUTDOWN ACK ...
4502 */
4503 reply = sctp_make_shutdown_ack(asoc, chunk);
4504 if (!reply)
4505 goto nomem;
4506
4507 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
4508 * the T2-shutdown timer.
4509 */
4510 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
4511
4512 /* and start/restart a T2-shutdown timer of its own, */
4513 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
4514 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4515
4516 if (asoc->autoclose)
4517 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4518 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
4519
4520 /* Enter the SHUTDOWN-ACK-SENT state. */
4521 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4522 SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT));
4523
4524 /* sctp-implguide 2.10 Issues with Heartbeating and failover
4525 *
4526 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09004527 * or SHUTDOWN-ACK.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004528 */
4529 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
4530
4531 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
4532
4533 return SCTP_DISPOSITION_CONSUME;
4534
4535nomem:
4536 return SCTP_DISPOSITION_NOMEM;
4537}
4538
4539/*
4540 * Ignore the event defined as other
4541 *
4542 * The return value is the disposition of the event.
4543 */
4544sctp_disposition_t sctp_sf_ignore_other(const struct sctp_endpoint *ep,
4545 const struct sctp_association *asoc,
4546 const sctp_subtype_t type,
4547 void *arg,
4548 sctp_cmd_seq_t *commands)
4549{
4550 SCTP_DEBUG_PRINTK("The event other type %d is ignored\n", type.other);
4551 return SCTP_DISPOSITION_DISCARD;
4552}
4553
4554/************************************************************
4555 * These are the state functions for handling timeout events.
4556 ************************************************************/
4557
4558/*
4559 * RTX Timeout
4560 *
4561 * Section: 6.3.3 Handle T3-rtx Expiration
4562 *
4563 * Whenever the retransmission timer T3-rtx expires for a destination
4564 * address, do the following:
4565 * [See below]
4566 *
4567 * The return value is the disposition of the chunk.
4568 */
4569sctp_disposition_t sctp_sf_do_6_3_3_rtx(const struct sctp_endpoint *ep,
4570 const struct sctp_association *asoc,
4571 const sctp_subtype_t type,
4572 void *arg,
4573 sctp_cmd_seq_t *commands)
4574{
4575 struct sctp_transport *transport = arg;
4576
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07004577 SCTP_INC_STATS(SCTP_MIB_T3_RTX_EXPIREDS);
4578
Linus Torvalds1da177e2005-04-16 15:20:36 -07004579 if (asoc->overall_error_count >= asoc->max_retrans) {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004580 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4581 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004582 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
4583 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08004584 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004585 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4586 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
4587 return SCTP_DISPOSITION_DELETE_TCB;
4588 }
4589
4590 /* E1) For the destination address for which the timer
4591 * expires, adjust its ssthresh with rules defined in Section
4592 * 7.2.3 and set the cwnd <- MTU.
4593 */
4594
4595 /* E2) For the destination address for which the timer
4596 * expires, set RTO <- RTO * 2 ("back off the timer"). The
4597 * maximum value discussed in rule C7 above (RTO.max) may be
4598 * used to provide an upper bound to this doubling operation.
4599 */
4600
4601 /* E3) Determine how many of the earliest (i.e., lowest TSN)
4602 * outstanding DATA chunks for the address for which the
4603 * T3-rtx has expired will fit into a single packet, subject
4604 * to the MTU constraint for the path corresponding to the
4605 * destination transport address to which the retransmission
4606 * is being sent (this may be different from the address for
4607 * which the timer expires [see Section 6.4]). Call this
4608 * value K. Bundle and retransmit those K DATA chunks in a
4609 * single packet to the destination endpoint.
4610 *
4611 * Note: Any DATA chunks that were sent to the address for
4612 * which the T3-rtx timer expired but did not fit in one MTU
4613 * (rule E3 above), should be marked for retransmission and
4614 * sent as soon as cwnd allows (normally when a SACK arrives).
4615 */
4616
Linus Torvalds1da177e2005-04-16 15:20:36 -07004617 /* Do some failure management (Section 8.2). */
4618 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
4619
Vlad Yasevich1845a572007-02-21 02:06:19 -08004620 /* NB: Rules E4 and F1 are implicit in R1. */
4621 sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN, SCTP_TRANSPORT(transport));
4622
Linus Torvalds1da177e2005-04-16 15:20:36 -07004623 return SCTP_DISPOSITION_CONSUME;
4624}
4625
4626/*
4627 * Generate delayed SACK on timeout
4628 *
4629 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
4630 *
4631 * The guidelines on delayed acknowledgement algorithm specified in
4632 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
4633 * acknowledgement SHOULD be generated for at least every second packet
4634 * (not every second DATA chunk) received, and SHOULD be generated
4635 * within 200 ms of the arrival of any unacknowledged DATA chunk. In
4636 * some situations it may be beneficial for an SCTP transmitter to be
4637 * more conservative than the algorithms detailed in this document
4638 * allow. However, an SCTP transmitter MUST NOT be more aggressive than
4639 * the following algorithms allow.
4640 */
4641sctp_disposition_t sctp_sf_do_6_2_sack(const struct sctp_endpoint *ep,
4642 const struct sctp_association *asoc,
4643 const sctp_subtype_t type,
4644 void *arg,
4645 sctp_cmd_seq_t *commands)
4646{
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07004647 SCTP_INC_STATS(SCTP_MIB_DELAY_SACK_EXPIREDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004648 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
4649 return SCTP_DISPOSITION_CONSUME;
4650}
4651
4652/*
Frank Filz3f7a87d2005-06-20 13:14:57 -07004653 * sctp_sf_t1_init_timer_expire
Linus Torvalds1da177e2005-04-16 15:20:36 -07004654 *
4655 * Section: 4 Note: 2
4656 * Verification Tag:
4657 * Inputs
4658 * (endpoint, asoc)
4659 *
4660 * RFC 2960 Section 4 Notes
4661 * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT
4662 * and re-start the T1-init timer without changing state. This MUST
4663 * be repeated up to 'Max.Init.Retransmits' times. After that, the
4664 * endpoint MUST abort the initialization process and report the
4665 * error to SCTP user.
4666 *
Frank Filz3f7a87d2005-06-20 13:14:57 -07004667 * Outputs
4668 * (timers, events)
4669 *
4670 */
4671sctp_disposition_t sctp_sf_t1_init_timer_expire(const struct sctp_endpoint *ep,
4672 const struct sctp_association *asoc,
4673 const sctp_subtype_t type,
4674 void *arg,
4675 sctp_cmd_seq_t *commands)
4676{
4677 struct sctp_chunk *repl = NULL;
4678 struct sctp_bind_addr *bp;
4679 int attempts = asoc->init_err_counter + 1;
4680
4681 SCTP_DEBUG_PRINTK("Timer T1 expired (INIT).\n");
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07004682 SCTP_INC_STATS(SCTP_MIB_T1_INIT_EXPIREDS);
Frank Filz3f7a87d2005-06-20 13:14:57 -07004683
Vlad Yasevich81845c22006-01-30 15:59:54 -08004684 if (attempts <= asoc->max_init_attempts) {
Frank Filz3f7a87d2005-06-20 13:14:57 -07004685 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
4686 repl = sctp_make_init(asoc, bp, GFP_ATOMIC, 0);
4687 if (!repl)
4688 return SCTP_DISPOSITION_NOMEM;
4689
4690 /* Choose transport for INIT. */
4691 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
4692 SCTP_CHUNK(repl));
4693
4694 /* Issue a sideeffect to do the needed accounting. */
4695 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_RESTART,
4696 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4697
4698 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
4699 } else {
4700 SCTP_DEBUG_PRINTK("Giving up on INIT, attempts: %d"
4701 " max_init_attempts: %d\n",
4702 attempts, asoc->max_init_attempts);
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004703 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4704 SCTP_ERROR(ETIMEDOUT));
Frank Filz3f7a87d2005-06-20 13:14:57 -07004705 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08004706 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Frank Filz3f7a87d2005-06-20 13:14:57 -07004707 return SCTP_DISPOSITION_DELETE_TCB;
4708 }
4709
4710 return SCTP_DISPOSITION_CONSUME;
4711}
4712
4713/*
4714 * sctp_sf_t1_cookie_timer_expire
4715 *
4716 * Section: 4 Note: 2
4717 * Verification Tag:
4718 * Inputs
4719 * (endpoint, asoc)
4720 *
4721 * RFC 2960 Section 4 Notes
4722 * 3) If the T1-cookie timer expires, the endpoint MUST retransmit
Linus Torvalds1da177e2005-04-16 15:20:36 -07004723 * COOKIE ECHO and re-start the T1-cookie timer without changing
4724 * state. This MUST be repeated up to 'Max.Init.Retransmits' times.
4725 * After that, the endpoint MUST abort the initialization process and
4726 * report the error to SCTP user.
4727 *
4728 * Outputs
4729 * (timers, events)
4730 *
4731 */
Frank Filz3f7a87d2005-06-20 13:14:57 -07004732sctp_disposition_t sctp_sf_t1_cookie_timer_expire(const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07004733 const struct sctp_association *asoc,
4734 const sctp_subtype_t type,
4735 void *arg,
4736 sctp_cmd_seq_t *commands)
4737{
Frank Filz3f7a87d2005-06-20 13:14:57 -07004738 struct sctp_chunk *repl = NULL;
4739 int attempts = asoc->init_err_counter + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004740
Frank Filz3f7a87d2005-06-20 13:14:57 -07004741 SCTP_DEBUG_PRINTK("Timer T1 expired (COOKIE-ECHO).\n");
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07004742 SCTP_INC_STATS(SCTP_MIB_T1_COOKIE_EXPIREDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004743
Vlad Yasevich81845c22006-01-30 15:59:54 -08004744 if (attempts <= asoc->max_init_attempts) {
Frank Filz3f7a87d2005-06-20 13:14:57 -07004745 repl = sctp_make_cookie_echo(asoc, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004746 if (!repl)
Frank Filz3f7a87d2005-06-20 13:14:57 -07004747 return SCTP_DISPOSITION_NOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004748
4749 /* Issue a sideeffect to do the needed accounting. */
Frank Filz3f7a87d2005-06-20 13:14:57 -07004750 sctp_add_cmd_sf(commands, SCTP_CMD_COOKIEECHO_RESTART,
4751 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
4752
Linus Torvalds1da177e2005-04-16 15:20:36 -07004753 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
4754 } else {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004755 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4756 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004757 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08004758 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004759 return SCTP_DISPOSITION_DELETE_TCB;
4760 }
4761
4762 return SCTP_DISPOSITION_CONSUME;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004763}
4764
4765/* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN
4766 * with the updated last sequential TSN received from its peer.
4767 *
4768 * An endpoint should limit the number of retransmissions of the
4769 * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'.
4770 * If this threshold is exceeded the endpoint should destroy the TCB and
4771 * MUST report the peer endpoint unreachable to the upper layer (and
4772 * thus the association enters the CLOSED state). The reception of any
4773 * packet from its peer (i.e. as the peer sends all of its queued DATA
4774 * chunks) should clear the endpoint's retransmission count and restart
4775 * the T2-Shutdown timer, giving its peer ample opportunity to transmit
4776 * all of its queued DATA chunks that have not yet been sent.
4777 */
4778sctp_disposition_t sctp_sf_t2_timer_expire(const struct sctp_endpoint *ep,
4779 const struct sctp_association *asoc,
4780 const sctp_subtype_t type,
4781 void *arg,
4782 sctp_cmd_seq_t *commands)
4783{
4784 struct sctp_chunk *reply = NULL;
4785
4786 SCTP_DEBUG_PRINTK("Timer T2 expired.\n");
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07004787 SCTP_INC_STATS(SCTP_MIB_T2_SHUTDOWN_EXPIREDS);
4788
Linus Torvalds1da177e2005-04-16 15:20:36 -07004789 if (asoc->overall_error_count >= asoc->max_retrans) {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004790 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4791 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004792 /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
4793 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08004794 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004795 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4796 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
4797 return SCTP_DISPOSITION_DELETE_TCB;
4798 }
4799
4800 switch (asoc->state) {
4801 case SCTP_STATE_SHUTDOWN_SENT:
4802 reply = sctp_make_shutdown(asoc, NULL);
4803 break;
4804
4805 case SCTP_STATE_SHUTDOWN_ACK_SENT:
4806 reply = sctp_make_shutdown_ack(asoc, NULL);
4807 break;
4808
4809 default:
4810 BUG();
4811 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -07004812 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07004813
4814 if (!reply)
4815 goto nomem;
4816
4817 /* Do some failure management (Section 8.2). */
4818 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
4819 SCTP_TRANSPORT(asoc->shutdown_last_sent_to));
4820
4821 /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for
4822 * the T2-shutdown timer.
4823 */
4824 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
4825
4826 /* Restart the T2-shutdown timer. */
4827 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
4828 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4829 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
4830 return SCTP_DISPOSITION_CONSUME;
4831
4832nomem:
4833 return SCTP_DISPOSITION_NOMEM;
4834}
4835
4836/*
4837 * ADDIP Section 4.1 ASCONF CHunk Procedures
4838 * If the T4 RTO timer expires the endpoint should do B1 to B5
4839 */
4840sctp_disposition_t sctp_sf_t4_timer_expire(
4841 const struct sctp_endpoint *ep,
4842 const struct sctp_association *asoc,
4843 const sctp_subtype_t type,
4844 void *arg,
4845 sctp_cmd_seq_t *commands)
4846{
4847 struct sctp_chunk *chunk = asoc->addip_last_asconf;
4848 struct sctp_transport *transport = chunk->transport;
4849
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07004850 SCTP_INC_STATS(SCTP_MIB_T4_RTO_EXPIREDS);
4851
Linus Torvalds1da177e2005-04-16 15:20:36 -07004852 /* ADDIP 4.1 B1) Increment the error counters and perform path failure
4853 * detection on the appropriate destination address as defined in
4854 * RFC2960 [5] section 8.1 and 8.2.
4855 */
4856 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
4857
4858 /* Reconfig T4 timer and transport. */
4859 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
4860
4861 /* ADDIP 4.1 B2) Increment the association error counters and perform
4862 * endpoint failure detection on the association as defined in
4863 * RFC2960 [5] section 8.1 and 8.2.
4864 * association error counter is incremented in SCTP_CMD_STRIKE.
4865 */
4866 if (asoc->overall_error_count >= asoc->max_retrans) {
4867 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4868 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004869 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4870 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004871 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08004872 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004873 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4874 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
4875 return SCTP_DISPOSITION_ABORT;
4876 }
4877
4878 /* ADDIP 4.1 B3) Back-off the destination address RTO value to which
4879 * the ASCONF chunk was sent by doubling the RTO timer value.
4880 * This is done in SCTP_CMD_STRIKE.
4881 */
4882
4883 /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible
4884 * choose an alternate destination address (please refer to RFC2960
4885 * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09004886 * chunk, it MUST be the same (including its serial number) as the last
Linus Torvalds1da177e2005-04-16 15:20:36 -07004887 * ASCONF sent.
4888 */
4889 sctp_chunk_hold(asoc->addip_last_asconf);
4890 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4891 SCTP_CHUNK(asoc->addip_last_asconf));
4892
4893 /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different
4894 * destination is selected, then the RTO used will be that of the new
4895 * destination address.
4896 */
4897 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
4898 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
4899
4900 return SCTP_DISPOSITION_CONSUME;
4901}
4902
4903/* sctpimpguide-05 Section 2.12.2
4904 * The sender of the SHUTDOWN MAY also start an overall guard timer
4905 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
4906 * At the expiration of this timer the sender SHOULD abort the association
4907 * by sending an ABORT chunk.
4908 */
4909sctp_disposition_t sctp_sf_t5_timer_expire(const struct sctp_endpoint *ep,
4910 const struct sctp_association *asoc,
4911 const sctp_subtype_t type,
4912 void *arg,
4913 sctp_cmd_seq_t *commands)
4914{
4915 struct sctp_chunk *reply = NULL;
4916
4917 SCTP_DEBUG_PRINTK("Timer T5 expired.\n");
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07004918 SCTP_INC_STATS(SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004919
4920 reply = sctp_make_abort(asoc, NULL, 0);
4921 if (!reply)
4922 goto nomem;
4923
4924 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004925 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4926 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004927 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08004928 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004929
4930 return SCTP_DISPOSITION_DELETE_TCB;
4931nomem:
4932 return SCTP_DISPOSITION_NOMEM;
4933}
4934
4935/* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires,
4936 * the association is automatically closed by starting the shutdown process.
4937 * The work that needs to be done is same as when SHUTDOWN is initiated by
4938 * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown().
4939 */
4940sctp_disposition_t sctp_sf_autoclose_timer_expire(
4941 const struct sctp_endpoint *ep,
4942 const struct sctp_association *asoc,
4943 const sctp_subtype_t type,
4944 void *arg,
4945 sctp_cmd_seq_t *commands)
4946{
4947 int disposition;
4948
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07004949 SCTP_INC_STATS(SCTP_MIB_AUTOCLOSE_EXPIREDS);
4950
Linus Torvalds1da177e2005-04-16 15:20:36 -07004951 /* From 9.2 Shutdown of an Association
4952 * Upon receipt of the SHUTDOWN primitive from its upper
4953 * layer, the endpoint enters SHUTDOWN-PENDING state and
4954 * remains there until all outstanding data has been
4955 * acknowledged by its peer. The endpoint accepts no new data
4956 * from its upper layer, but retransmits data to the far end
4957 * if necessary to fill gaps.
4958 */
4959 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4960 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
4961
4962 /* sctpimpguide-05 Section 2.12.2
4963 * The sender of the SHUTDOWN MAY also start an overall guard timer
4964 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09004965 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07004966 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4967 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4968 disposition = SCTP_DISPOSITION_CONSUME;
4969 if (sctp_outq_is_empty(&asoc->outqueue)) {
4970 disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type,
4971 arg, commands);
4972 }
4973 return disposition;
4974}
4975
4976/*****************************************************************************
4977 * These are sa state functions which could apply to all types of events.
4978 ****************************************************************************/
4979
4980/*
4981 * This table entry is not implemented.
4982 *
4983 * Inputs
4984 * (endpoint, asoc, chunk)
4985 *
4986 * The return value is the disposition of the chunk.
4987 */
4988sctp_disposition_t sctp_sf_not_impl(const struct sctp_endpoint *ep,
4989 const struct sctp_association *asoc,
4990 const sctp_subtype_t type,
4991 void *arg,
4992 sctp_cmd_seq_t *commands)
4993{
4994 return SCTP_DISPOSITION_NOT_IMPL;
4995}
4996
4997/*
4998 * This table entry represents a bug.
4999 *
5000 * Inputs
5001 * (endpoint, asoc, chunk)
5002 *
5003 * The return value is the disposition of the chunk.
5004 */
5005sctp_disposition_t sctp_sf_bug(const struct sctp_endpoint *ep,
5006 const struct sctp_association *asoc,
5007 const sctp_subtype_t type,
5008 void *arg,
5009 sctp_cmd_seq_t *commands)
5010{
5011 return SCTP_DISPOSITION_BUG;
5012}
5013
5014/*
5015 * This table entry represents the firing of a timer in the wrong state.
5016 * Since timer deletion cannot be guaranteed a timer 'may' end up firing
5017 * when the association is in the wrong state. This event should
5018 * be ignored, so as to prevent any rearming of the timer.
5019 *
5020 * Inputs
5021 * (endpoint, asoc, chunk)
5022 *
5023 * The return value is the disposition of the chunk.
5024 */
5025sctp_disposition_t sctp_sf_timer_ignore(const struct sctp_endpoint *ep,
5026 const struct sctp_association *asoc,
5027 const sctp_subtype_t type,
5028 void *arg,
5029 sctp_cmd_seq_t *commands)
5030{
5031 SCTP_DEBUG_PRINTK("Timer %d ignored.\n", type.chunk);
5032 return SCTP_DISPOSITION_CONSUME;
5033}
5034
5035/********************************************************************
5036 * 2nd Level Abstractions
5037 ********************************************************************/
5038
5039/* Pull the SACK chunk based on the SACK header. */
5040static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk)
5041{
5042 struct sctp_sackhdr *sack;
5043 unsigned int len;
5044 __u16 num_blocks;
5045 __u16 num_dup_tsns;
5046
5047 /* Protect ourselves from reading too far into
5048 * the skb from a bogus sender.
5049 */
5050 sack = (struct sctp_sackhdr *) chunk->skb->data;
5051
5052 num_blocks = ntohs(sack->num_gap_ack_blocks);
5053 num_dup_tsns = ntohs(sack->num_dup_tsns);
5054 len = sizeof(struct sctp_sackhdr);
5055 len += (num_blocks + num_dup_tsns) * sizeof(__u32);
5056 if (len > chunk->skb->len)
5057 return NULL;
5058
5059 skb_pull(chunk->skb, len);
5060
5061 return sack;
5062}
5063
5064/* Create an ABORT packet to be sent as a response, with the specified
5065 * error causes.
5066 */
5067static struct sctp_packet *sctp_abort_pkt_new(const struct sctp_endpoint *ep,
5068 const struct sctp_association *asoc,
5069 struct sctp_chunk *chunk,
5070 const void *payload,
5071 size_t paylen)
5072{
5073 struct sctp_packet *packet;
5074 struct sctp_chunk *abort;
5075
5076 packet = sctp_ootb_pkt_new(asoc, chunk);
5077
5078 if (packet) {
5079 /* Make an ABORT.
5080 * The T bit will be set if the asoc is NULL.
5081 */
5082 abort = sctp_make_abort(asoc, chunk, paylen);
5083 if (!abort) {
5084 sctp_ootb_pkt_free(packet);
5085 return NULL;
5086 }
Jerome Forissier047a2422005-04-28 11:58:43 -07005087
5088 /* Reflect vtag if T-Bit is set */
5089 if (sctp_test_T_bit(abort))
5090 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
5091
Linus Torvalds1da177e2005-04-16 15:20:36 -07005092 /* Add specified error causes, i.e., payload, to the
5093 * end of the chunk.
5094 */
5095 sctp_addto_chunk(abort, paylen, payload);
5096
5097 /* Set the skb to the belonging sock for accounting. */
5098 abort->skb->sk = ep->base.sk;
5099
5100 sctp_packet_append_chunk(packet, abort);
5101
5102 }
5103
5104 return packet;
5105}
5106
5107/* Allocate a packet for responding in the OOTB conditions. */
5108static struct sctp_packet *sctp_ootb_pkt_new(const struct sctp_association *asoc,
5109 const struct sctp_chunk *chunk)
5110{
5111 struct sctp_packet *packet;
5112 struct sctp_transport *transport;
5113 __u16 sport;
5114 __u16 dport;
5115 __u32 vtag;
5116
5117 /* Get the source and destination port from the inbound packet. */
5118 sport = ntohs(chunk->sctp_hdr->dest);
5119 dport = ntohs(chunk->sctp_hdr->source);
5120
5121 /* The V-tag is going to be the same as the inbound packet if no
5122 * association exists, otherwise, use the peer's vtag.
5123 */
5124 if (asoc) {
5125 vtag = asoc->peer.i.init_tag;
5126 } else {
5127 /* Special case the INIT and stale COOKIE_ECHO as there is no
5128 * vtag yet.
5129 */
5130 switch(chunk->chunk_hdr->type) {
5131 case SCTP_CID_INIT:
5132 {
5133 sctp_init_chunk_t *init;
5134
5135 init = (sctp_init_chunk_t *)chunk->chunk_hdr;
5136 vtag = ntohl(init->init_hdr.init_tag);
5137 break;
5138 }
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09005139 default:
Linus Torvalds1da177e2005-04-16 15:20:36 -07005140 vtag = ntohl(chunk->sctp_hdr->vtag);
5141 break;
5142 }
5143 }
5144
5145 /* Make a transport for the bucket, Eliza... */
Al Viro6a1e5f32006-11-20 17:12:25 -08005146 transport = sctp_transport_new(sctp_source(chunk), GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005147 if (!transport)
5148 goto nomem;
5149
5150 /* Cache a route for the transport with the chunk's destination as
5151 * the source address.
5152 */
Al Viro16b0a032006-11-20 17:13:38 -08005153 sctp_transport_route(transport, (union sctp_addr *)&chunk->dest,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005154 sctp_sk(sctp_get_ctl_sock()));
5155
5156 packet = sctp_packet_init(&transport->packet, transport, sport, dport);
5157 packet = sctp_packet_config(packet, vtag, 0);
5158
5159 return packet;
5160
5161nomem:
5162 return NULL;
5163}
5164
5165/* Free the packet allocated earlier for responding in the OOTB condition. */
5166void sctp_ootb_pkt_free(struct sctp_packet *packet)
5167{
5168 sctp_transport_free(packet->transport);
5169}
5170
5171/* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */
5172static void sctp_send_stale_cookie_err(const struct sctp_endpoint *ep,
5173 const struct sctp_association *asoc,
5174 const struct sctp_chunk *chunk,
5175 sctp_cmd_seq_t *commands,
5176 struct sctp_chunk *err_chunk)
5177{
5178 struct sctp_packet *packet;
5179
5180 if (err_chunk) {
5181 packet = sctp_ootb_pkt_new(asoc, chunk);
5182 if (packet) {
5183 struct sctp_signed_cookie *cookie;
5184
5185 /* Override the OOTB vtag from the cookie. */
5186 cookie = chunk->subh.cookie_hdr;
5187 packet->vtag = cookie->c.peer_vtag;
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09005188
Linus Torvalds1da177e2005-04-16 15:20:36 -07005189 /* Set the skb to the belonging sock for accounting. */
5190 err_chunk->skb->sk = ep->base.sk;
5191 sctp_packet_append_chunk(packet, err_chunk);
5192 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
5193 SCTP_PACKET(packet));
5194 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
5195 } else
5196 sctp_chunk_free (err_chunk);
5197 }
5198}
5199
5200
5201/* Process a data chunk */
5202static int sctp_eat_data(const struct sctp_association *asoc,
5203 struct sctp_chunk *chunk,
5204 sctp_cmd_seq_t *commands)
5205{
5206 sctp_datahdr_t *data_hdr;
5207 struct sctp_chunk *err;
5208 size_t datalen;
5209 sctp_verb_t deliver;
5210 int tmp;
5211 __u32 tsn;
Neil Horman049b3ff2005-11-11 16:08:24 -08005212 int account_value;
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005213 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
Neil Horman049b3ff2005-11-11 16:08:24 -08005214 struct sock *sk = asoc->base.sk;
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005215 int rcvbuf_over = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005216
5217 data_hdr = chunk->subh.data_hdr = (sctp_datahdr_t *)chunk->skb->data;
5218 skb_pull(chunk->skb, sizeof(sctp_datahdr_t));
5219
5220 tsn = ntohl(data_hdr->tsn);
5221 SCTP_DEBUG_PRINTK("eat_data: TSN 0x%x.\n", tsn);
5222
5223 /* ASSERT: Now skb->data is really the user data. */
5224
Neil Horman049b3ff2005-11-11 16:08:24 -08005225 /*
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005226 * If we are established, and we have used up our receive buffer
5227 * memory, think about droping the frame.
5228 * Note that we have an opportunity to improve performance here.
5229 * If we accept one chunk from an skbuff, we have to keep all the
5230 * memory of that skbuff around until the chunk is read into user
5231 * space. Therefore, once we accept 1 chunk we may as well accept all
5232 * remaining chunks in the skbuff. The data_accepted flag helps us do
5233 * that.
Neil Horman049b3ff2005-11-11 16:08:24 -08005234 */
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005235 if ((asoc->state == SCTP_STATE_ESTABLISHED) && (!chunk->data_accepted)) {
Neil Horman049b3ff2005-11-11 16:08:24 -08005236 /*
5237 * If the receive buffer policy is 1, then each
5238 * association can allocate up to sk_rcvbuf bytes
5239 * otherwise, all the associations in aggregate
5240 * may allocate up to sk_rcvbuf bytes
5241 */
5242 if (asoc->ep->rcvbuf_policy)
5243 account_value = atomic_read(&asoc->rmem_alloc);
5244 else
5245 account_value = atomic_read(&sk->sk_rmem_alloc);
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005246 if (account_value > sk->sk_rcvbuf) {
5247 /*
5248 * We need to make forward progress, even when we are
5249 * under memory pressure, so we always allow the
5250 * next tsn after the ctsn ack point to be accepted.
5251 * This lets us avoid deadlocks in which we have to
5252 * drop frames that would otherwise let us drain the
5253 * receive queue.
5254 */
5255 if ((sctp_tsnmap_get_ctsn(map) + 1) != tsn)
5256 return SCTP_IERROR_IGNORE_TSN;
Neil Horman049b3ff2005-11-11 16:08:24 -08005257
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005258 /*
5259 * We're going to accept the frame but we should renege
5260 * to make space for it. This will send us down that
5261 * path later in this function.
5262 */
5263 rcvbuf_over = 1;
5264 }
Neil Horman049b3ff2005-11-11 16:08:24 -08005265 }
5266
Linus Torvalds1da177e2005-04-16 15:20:36 -07005267 /* Process ECN based congestion.
5268 *
5269 * Since the chunk structure is reused for all chunks within
5270 * a packet, we use ecn_ce_done to track if we've already
5271 * done CE processing for this packet.
5272 *
5273 * We need to do ECN processing even if we plan to discard the
5274 * chunk later.
5275 */
5276
5277 if (!chunk->ecn_ce_done) {
5278 struct sctp_af *af;
5279 chunk->ecn_ce_done = 1;
5280
5281 af = sctp_get_af_specific(
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -07005282 ipver2af(ip_hdr(chunk->skb)->version));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005283
5284 if (af && af->is_ce(chunk->skb) && asoc->peer.ecn_capable) {
5285 /* Do real work as sideffect. */
5286 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_CE,
5287 SCTP_U32(tsn));
5288 }
5289 }
5290
5291 tmp = sctp_tsnmap_check(&asoc->peer.tsn_map, tsn);
5292 if (tmp < 0) {
5293 /* The TSN is too high--silently discard the chunk and
5294 * count on it getting retransmitted later.
5295 */
5296 return SCTP_IERROR_HIGH_TSN;
5297 } else if (tmp > 0) {
5298 /* This is a duplicate. Record it. */
5299 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_DUP, SCTP_U32(tsn));
5300 return SCTP_IERROR_DUP_TSN;
5301 }
5302
5303 /* This is a new TSN. */
5304
5305 /* Discard if there is no room in the receive window.
5306 * Actually, allow a little bit of overflow (up to a MTU).
5307 */
5308 datalen = ntohs(chunk->chunk_hdr->length);
5309 datalen -= sizeof(sctp_data_chunk_t);
5310
5311 deliver = SCTP_CMD_CHUNK_ULP;
5312
5313 /* Think about partial delivery. */
5314 if ((datalen >= asoc->rwnd) && (!asoc->ulpq.pd_mode)) {
5315
5316 /* Even if we don't accept this chunk there is
5317 * memory pressure.
5318 */
5319 sctp_add_cmd_sf(commands, SCTP_CMD_PART_DELIVER, SCTP_NULL());
5320 }
5321
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09005322 /* Spill over rwnd a little bit. Note: While allowed, this spill over
Linus Torvalds1da177e2005-04-16 15:20:36 -07005323 * seems a bit troublesome in that frag_point varies based on
5324 * PMTU. In cases, such as loopback, this might be a rather
5325 * large spill over.
Neil Hormand5b9f4c2006-06-17 22:59:03 -07005326 * NOTE: If we have a full receive buffer here, we only renege if
5327 * our receiver can still make progress without the tsn being
5328 * received. We do this because in the event that the associations
5329 * receive queue is empty we are filling a leading gap, and since
5330 * reneging moves the gap to the end of the tsn stream, we are likely
5331 * to stall again very shortly. Avoiding the renege when we fill a
5332 * leading gap is a good heuristic for avoiding such steady state
5333 * stalls.
Linus Torvalds1da177e2005-04-16 15:20:36 -07005334 */
5335 if (!asoc->rwnd || asoc->rwnd_over ||
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005336 (datalen > asoc->rwnd + asoc->frag_point) ||
Neil Hormand5b9f4c2006-06-17 22:59:03 -07005337 (rcvbuf_over && (!skb_queue_len(&sk->sk_receive_queue)))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07005338
5339 /* If this is the next TSN, consider reneging to make
5340 * room. Note: Playing nice with a confused sender. A
5341 * malicious sender can still eat up all our buffer
5342 * space and in the future we may want to detect and
5343 * do more drastic reneging.
5344 */
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005345 if (sctp_tsnmap_has_gap(map) &&
5346 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07005347 SCTP_DEBUG_PRINTK("Reneging for tsn:%u\n", tsn);
5348 deliver = SCTP_CMD_RENEGE;
5349 } else {
5350 SCTP_DEBUG_PRINTK("Discard tsn: %u len: %Zd, "
5351 "rwnd: %d\n", tsn, datalen,
5352 asoc->rwnd);
5353 return SCTP_IERROR_IGNORE_TSN;
5354 }
5355 }
5356
5357 /*
5358 * Section 3.3.10.9 No User Data (9)
5359 *
5360 * Cause of error
5361 * ---------------
5362 * No User Data: This error cause is returned to the originator of a
5363 * DATA chunk if a received DATA chunk has no user data.
5364 */
5365 if (unlikely(0 == datalen)) {
5366 err = sctp_make_abort_no_data(asoc, chunk, tsn);
5367 if (err) {
5368 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
5369 SCTP_CHUNK(err));
5370 }
5371 /* We are going to ABORT, so we might as well stop
5372 * processing the rest of the chunks in the packet.
5373 */
5374 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07005375 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5376 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005377 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08005378 SCTP_PERR(SCTP_ERROR_NO_DATA));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005379 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
5380 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
5381 return SCTP_IERROR_NO_DATA;
5382 }
5383
5384 /* If definately accepting the DATA chunk, record its TSN, otherwise
5385 * wait for renege processing.
5386 */
5387 if (SCTP_CMD_CHUNK_ULP == deliver)
5388 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_TSN, SCTP_U32(tsn));
5389
Sridhar Samudrala9faa7302006-07-21 14:49:07 -07005390 chunk->data_accepted = 1;
5391
Linus Torvalds1da177e2005-04-16 15:20:36 -07005392 /* Note: Some chunks may get overcounted (if we drop) or overcounted
5393 * if we renege and the chunk arrives again.
5394 */
5395 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
5396 SCTP_INC_STATS(SCTP_MIB_INUNORDERCHUNKS);
5397 else
5398 SCTP_INC_STATS(SCTP_MIB_INORDERCHUNKS);
5399
5400 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
5401 *
5402 * If an endpoint receive a DATA chunk with an invalid stream
5403 * identifier, it shall acknowledge the reception of the DATA chunk
5404 * following the normal procedure, immediately send an ERROR chunk
5405 * with cause set to "Invalid Stream Identifier" (See Section 3.3.10)
5406 * and discard the DATA chunk.
5407 */
5408 if (ntohs(data_hdr->stream) >= asoc->c.sinit_max_instreams) {
5409 err = sctp_make_op_error(asoc, chunk, SCTP_ERROR_INV_STRM,
5410 &data_hdr->stream,
5411 sizeof(data_hdr->stream));
5412 if (err)
5413 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
5414 SCTP_CHUNK(err));
5415 return SCTP_IERROR_BAD_STREAM;
5416 }
5417
5418 /* Send the data up to the user. Note: Schedule the
5419 * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK
5420 * chunk needs the updated rwnd.
5421 */
5422 sctp_add_cmd_sf(commands, deliver, SCTP_CHUNK(chunk));
5423
5424 return SCTP_IERROR_NO_ERROR;
5425}