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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,
Sridhar Samudrala8de8c872006-05-19 10:58:12 -070096 __u16 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,
189 0, 0, 0, GFP_ATOMIC);
190 if (!ev)
191 goto nomem;
192
193 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
194
195 /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint
196 * will verify that it is in SHUTDOWN-ACK-SENT state, if it is
197 * not the chunk should be discarded. If the endpoint is in
198 * the SHUTDOWN-ACK-SENT state the endpoint should stop the
199 * T2-shutdown timer and remove all knowledge of the
200 * association (and thus the association enters the CLOSED
201 * state).
202 */
203 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
204 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
205
206 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
207 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
208
209 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
210 SCTP_STATE(SCTP_STATE_CLOSED));
211
212 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
213 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
214
215 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
216
217 return SCTP_DISPOSITION_DELETE_TCB;
218
219nomem:
220 return SCTP_DISPOSITION_NOMEM;
221}
222
223/*
224 * Respond to a normal INIT chunk.
225 * We are the side that is being asked for an association.
226 *
227 * Section: 5.1 Normal Establishment of an Association, B
228 * B) "Z" shall respond immediately with an INIT ACK chunk. The
229 * destination IP address of the INIT ACK MUST be set to the source
230 * IP address of the INIT to which this INIT ACK is responding. In
231 * the response, besides filling in other parameters, "Z" must set the
232 * Verification Tag field to Tag_A, and also provide its own
233 * Verification Tag (Tag_Z) in the Initiate Tag field.
234 *
235 * Verification Tag: Must be 0.
236 *
237 * Inputs
238 * (endpoint, asoc, chunk)
239 *
240 * Outputs
241 * (asoc, reply_msg, msg_up, timers, counters)
242 *
243 * The return value is the disposition of the chunk.
244 */
245sctp_disposition_t sctp_sf_do_5_1B_init(const struct sctp_endpoint *ep,
246 const struct sctp_association *asoc,
247 const sctp_subtype_t type,
248 void *arg,
249 sctp_cmd_seq_t *commands)
250{
251 struct sctp_chunk *chunk = arg;
252 struct sctp_chunk *repl;
253 struct sctp_association *new_asoc;
254 struct sctp_chunk *err_chunk;
255 struct sctp_packet *packet;
256 sctp_unrecognized_param_t *unk_param;
257 struct sock *sk;
258 int len;
259
260 /* 6.10 Bundling
261 * An endpoint MUST NOT bundle INIT, INIT ACK or
262 * SHUTDOWN COMPLETE with any other chunks.
263 *
264 * IG Section 2.11.2
265 * Furthermore, we require that the receiver of an INIT chunk MUST
266 * enforce these rules by silently discarding an arriving packet
267 * with an INIT chunk that is bundled with other chunks.
268 */
269 if (!chunk->singleton)
270 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
271
272 /* If the packet is an OOTB packet which is temporarily on the
273 * control endpoint, respond with an ABORT.
274 */
275 if (ep == sctp_sk((sctp_get_ctl_sock()))->ep)
276 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
277
278 sk = ep->base.sk;
279 /* If the endpoint is not listening or if the number of associations
280 * on the TCP-style socket exceed the max backlog, respond with an
281 * ABORT.
282 */
283 if (!sctp_sstate(sk, LISTENING) ||
284 (sctp_style(sk, TCP) &&
285 sk_acceptq_is_full(sk)))
286 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
287
288 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
289 * Tag.
290 */
291 if (chunk->sctp_hdr->vtag != 0)
292 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
293
294 /* Make sure that the INIT chunk has a valid length.
295 * Normally, this would cause an ABORT with a Protocol Violation
296 * error, but since we don't have an association, we'll
297 * just discard the packet.
298 */
299 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
300 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
301
302 /* Verify the INIT chunk before processing it. */
303 err_chunk = NULL;
304 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
305 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
306 &err_chunk)) {
307 /* This chunk contains fatal error. It is to be discarded.
308 * Send an ABORT, with causes if there is any.
309 */
310 if (err_chunk) {
311 packet = sctp_abort_pkt_new(ep, asoc, arg,
312 (__u8 *)(err_chunk->chunk_hdr) +
313 sizeof(sctp_chunkhdr_t),
314 ntohs(err_chunk->chunk_hdr->length) -
315 sizeof(sctp_chunkhdr_t));
316
317 sctp_chunk_free(err_chunk);
318
319 if (packet) {
320 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
321 SCTP_PACKET(packet));
322 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
323 return SCTP_DISPOSITION_CONSUME;
324 } else {
325 return SCTP_DISPOSITION_NOMEM;
326 }
327 } else {
328 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg,
329 commands);
330 }
331 }
332
333 /* Grab the INIT header. */
334 chunk->subh.init_hdr = (sctp_inithdr_t *)chunk->skb->data;
335
336 /* Tag the variable length parameters. */
337 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
338
339 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
340 if (!new_asoc)
341 goto nomem;
342
343 /* The call, sctp_process_init(), can fail on memory allocation. */
344 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
345 sctp_source(chunk),
346 (sctp_init_chunk_t *)chunk->chunk_hdr,
347 GFP_ATOMIC))
348 goto nomem_init;
349
350 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
351
352 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
353
354 /* If there are errors need to be reported for unknown parameters,
355 * make sure to reserve enough room in the INIT ACK for them.
356 */
357 len = 0;
358 if (err_chunk)
359 len = ntohs(err_chunk->chunk_hdr->length) -
360 sizeof(sctp_chunkhdr_t);
361
362 if (sctp_assoc_set_bind_addr_from_ep(new_asoc, GFP_ATOMIC) < 0)
363 goto nomem_ack;
364
365 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
366 if (!repl)
367 goto nomem_ack;
368
369 /* If there are errors need to be reported for unknown parameters,
370 * include them in the outgoing INIT ACK as "Unrecognized parameter"
371 * parameter.
372 */
373 if (err_chunk) {
374 /* Get the "Unrecognized parameter" parameter(s) out of the
375 * ERROR chunk generated by sctp_verify_init(). Since the
376 * error cause code for "unknown parameter" and the
377 * "Unrecognized parameter" type is the same, we can
378 * construct the parameters in INIT ACK by copying the
379 * ERROR causes over.
380 */
381 unk_param = (sctp_unrecognized_param_t *)
382 ((__u8 *)(err_chunk->chunk_hdr) +
383 sizeof(sctp_chunkhdr_t));
384 /* Replace the cause code with the "Unrecognized parameter"
385 * parameter type.
386 */
387 sctp_addto_chunk(repl, len, unk_param);
388 sctp_chunk_free(err_chunk);
389 }
390
391 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
392
393 /*
394 * Note: After sending out INIT ACK with the State Cookie parameter,
395 * "Z" MUST NOT allocate any resources, nor keep any states for the
396 * new association. Otherwise, "Z" will be vulnerable to resource
397 * attacks.
398 */
399 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
400
401 return SCTP_DISPOSITION_DELETE_TCB;
402
403nomem_ack:
404 if (err_chunk)
405 sctp_chunk_free(err_chunk);
406nomem_init:
407 sctp_association_free(new_asoc);
408nomem:
409 return SCTP_DISPOSITION_NOMEM;
410}
411
412/*
413 * Respond to a normal INIT ACK chunk.
414 * We are the side that is initiating the association.
415 *
416 * Section: 5.1 Normal Establishment of an Association, C
417 * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init
418 * timer and leave COOKIE-WAIT state. "A" shall then send the State
419 * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start
420 * the T1-cookie timer, and enter the COOKIE-ECHOED state.
421 *
422 * Note: The COOKIE ECHO chunk can be bundled with any pending outbound
423 * DATA chunks, but it MUST be the first chunk in the packet and
424 * until the COOKIE ACK is returned the sender MUST NOT send any
425 * other packets to the peer.
426 *
427 * Verification Tag: 3.3.3
428 * If the value of the Initiate Tag in a received INIT ACK chunk is
429 * found to be 0, the receiver MUST treat it as an error and close the
430 * association by transmitting an ABORT.
431 *
432 * Inputs
433 * (endpoint, asoc, chunk)
434 *
435 * Outputs
436 * (asoc, reply_msg, msg_up, timers, counters)
437 *
438 * The return value is the disposition of the chunk.
439 */
440sctp_disposition_t sctp_sf_do_5_1C_ack(const struct sctp_endpoint *ep,
441 const struct sctp_association *asoc,
442 const sctp_subtype_t type,
443 void *arg,
444 sctp_cmd_seq_t *commands)
445{
446 struct sctp_chunk *chunk = arg;
447 sctp_init_chunk_t *initchunk;
448 __u32 init_tag;
449 struct sctp_chunk *err_chunk;
450 struct sctp_packet *packet;
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700451 __u16 error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452
453 if (!sctp_vtag_verify(chunk, asoc))
454 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
455
456 /* Make sure that the INIT-ACK chunk has a valid length */
457 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_initack_chunk_t)))
458 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
459 commands);
460 /* 6.10 Bundling
461 * An endpoint MUST NOT bundle INIT, INIT ACK or
462 * SHUTDOWN COMPLETE with any other chunks.
463 */
464 if (!chunk->singleton)
465 return SCTP_DISPOSITION_VIOLATION;
466
467 /* Grab the INIT header. */
468 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
469
470 init_tag = ntohl(chunk->subh.init_hdr->init_tag);
471
472 /* Verification Tag: 3.3.3
473 * If the value of the Initiate Tag in a received INIT ACK
474 * chunk is found to be 0, the receiver MUST treat it as an
475 * error and close the association by transmitting an ABORT.
476 */
477 if (!init_tag) {
478 struct sctp_chunk *reply = sctp_make_abort(asoc, chunk, 0);
479 if (!reply)
480 goto nomem;
481
482 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700483 return sctp_stop_t1_and_abort(commands, SCTP_ERROR_INV_PARAM,
484 ECONNREFUSED, asoc,
485 chunk->transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700486 }
487
488 /* Verify the INIT chunk before processing it. */
489 err_chunk = NULL;
490 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
491 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
492 &err_chunk)) {
493
494 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
495
496 /* This chunk contains fatal error. It is to be discarded.
497 * Send an ABORT, with causes if there is any.
498 */
499 if (err_chunk) {
500 packet = sctp_abort_pkt_new(ep, asoc, arg,
501 (__u8 *)(err_chunk->chunk_hdr) +
502 sizeof(sctp_chunkhdr_t),
503 ntohs(err_chunk->chunk_hdr->length) -
504 sizeof(sctp_chunkhdr_t));
505
506 sctp_chunk_free(err_chunk);
507
508 if (packet) {
509 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
510 SCTP_PACKET(packet));
511 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700512 error = SCTP_ERROR_INV_PARAM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513 } else {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700514 error = SCTP_ERROR_NO_RESOURCE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700515 }
516 } else {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700517 sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
518 error = SCTP_ERROR_INV_PARAM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700519 }
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700520 return sctp_stop_t1_and_abort(commands, error, ECONNREFUSED,
521 asoc, chunk->transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522 }
523
524 /* Tag the variable length parameters. Note that we never
525 * convert the parameters in an INIT chunk.
526 */
527 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
528
529 initchunk = (sctp_init_chunk_t *) chunk->chunk_hdr;
530
531 sctp_add_cmd_sf(commands, SCTP_CMD_PEER_INIT,
532 SCTP_PEER_INIT(initchunk));
533
Frank Filz3f7a87d2005-06-20 13:14:57 -0700534 /* Reset init error count upon receipt of INIT-ACK. */
535 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
536
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537 /* 5.1 C) "A" shall stop the T1-init timer and leave
538 * COOKIE-WAIT state. "A" shall then ... start the T1-cookie
539 * timer, and enter the COOKIE-ECHOED state.
540 */
541 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
542 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
543 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
544 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
545 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
546 SCTP_STATE(SCTP_STATE_COOKIE_ECHOED));
547
548 /* 5.1 C) "A" shall then send the State Cookie received in the
549 * INIT ACK chunk in a COOKIE ECHO chunk, ...
550 */
551 /* If there is any errors to report, send the ERROR chunk generated
552 * for unknown parameters as well.
553 */
554 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_COOKIE_ECHO,
555 SCTP_CHUNK(err_chunk));
556
557 return SCTP_DISPOSITION_CONSUME;
558
559nomem:
560 return SCTP_DISPOSITION_NOMEM;
561}
562
563/*
564 * Respond to a normal COOKIE ECHO chunk.
565 * We are the side that is being asked for an association.
566 *
567 * Section: 5.1 Normal Establishment of an Association, D
568 * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply
569 * with a COOKIE ACK chunk after building a TCB and moving to
570 * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with
571 * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK
572 * chunk MUST be the first chunk in the packet.
573 *
574 * IMPLEMENTATION NOTE: An implementation may choose to send the
575 * Communication Up notification to the SCTP user upon reception
576 * of a valid COOKIE ECHO chunk.
577 *
578 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
579 * D) Rules for packet carrying a COOKIE ECHO
580 *
581 * - When sending a COOKIE ECHO, the endpoint MUST use the value of the
582 * Initial Tag received in the INIT ACK.
583 *
584 * - The receiver of a COOKIE ECHO follows the procedures in Section 5.
585 *
586 * Inputs
587 * (endpoint, asoc, chunk)
588 *
589 * Outputs
590 * (asoc, reply_msg, msg_up, timers, counters)
591 *
592 * The return value is the disposition of the chunk.
593 */
594sctp_disposition_t sctp_sf_do_5_1D_ce(const struct sctp_endpoint *ep,
595 const struct sctp_association *asoc,
596 const sctp_subtype_t type, void *arg,
597 sctp_cmd_seq_t *commands)
598{
599 struct sctp_chunk *chunk = arg;
600 struct sctp_association *new_asoc;
601 sctp_init_chunk_t *peer_init;
602 struct sctp_chunk *repl;
603 struct sctp_ulpevent *ev;
604 int error = 0;
605 struct sctp_chunk *err_chk_p;
606
607 /* If the packet is an OOTB packet which is temporarily on the
608 * control endpoint, respond with an ABORT.
609 */
610 if (ep == sctp_sk((sctp_get_ctl_sock()))->ep)
611 return sctp_sf_ootb(ep, asoc, type, arg, commands);
612
613 /* Make sure that the COOKIE_ECHO chunk has a valid length.
614 * In this case, we check that we have enough for at least a
615 * chunk header. More detailed verification is done
616 * in sctp_unpack_cookie().
617 */
618 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
619 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
620
621 /* "Decode" the chunk. We have no optional parameters so we
622 * are in good shape.
623 */
624 chunk->subh.cookie_hdr =
625 (struct sctp_signed_cookie *)chunk->skb->data;
Sridhar Samudrala62b08082006-05-05 17:04:43 -0700626 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
627 sizeof(sctp_chunkhdr_t)))
628 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629
630 /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
631 * "Z" will reply with a COOKIE ACK chunk after building a TCB
632 * and moving to the ESTABLISHED state.
633 */
634 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
635 &err_chk_p);
636
637 /* FIXME:
638 * If the re-build failed, what is the proper error path
639 * from here?
640 *
641 * [We should abort the association. --piggy]
642 */
643 if (!new_asoc) {
644 /* FIXME: Several errors are possible. A bad cookie should
645 * be silently discarded, but think about logging it too.
646 */
647 switch (error) {
648 case -SCTP_IERROR_NOMEM:
649 goto nomem;
650
651 case -SCTP_IERROR_STALE_COOKIE:
652 sctp_send_stale_cookie_err(ep, asoc, chunk, commands,
653 err_chk_p);
654 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
655
656 case -SCTP_IERROR_BAD_SIG:
657 default:
658 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
659 };
660 }
661
662 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
663 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
664 SCTP_STATE(SCTP_STATE_ESTABLISHED));
665 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
666 SCTP_INC_STATS(SCTP_MIB_PASSIVEESTABS);
667 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
668
669 if (new_asoc->autoclose)
670 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
671 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
672
673 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
674
675 /* Re-build the bind address for the association is done in
676 * the sctp_unpack_cookie() already.
677 */
678 /* This is a brand-new association, so these are not yet side
679 * effects--it is safe to run them here.
680 */
681 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
682
683 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
684 &chunk->subh.cookie_hdr->c.peer_addr,
685 peer_init, GFP_ATOMIC))
686 goto nomem_init;
687
688 repl = sctp_make_cookie_ack(new_asoc, chunk);
689 if (!repl)
690 goto nomem_repl;
691
692 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
693
694 /* RFC 2960 5.1 Normal Establishment of an Association
695 *
696 * D) IMPLEMENTATION NOTE: An implementation may choose to
697 * send the Communication Up notification to the SCTP user
698 * upon reception of a valid COOKIE ECHO chunk.
699 */
700 ev = sctp_ulpevent_make_assoc_change(new_asoc, 0, SCTP_COMM_UP, 0,
701 new_asoc->c.sinit_num_ostreams,
702 new_asoc->c.sinit_max_instreams,
703 GFP_ATOMIC);
704 if (!ev)
705 goto nomem_ev;
706
707 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
708
709 /* Sockets API Draft Section 5.3.1.6
710 * When a peer sends a Adaption Layer Indication parameter , SCTP
711 * delivers this notification to inform the application that of the
712 * peers requested adaption layer.
713 */
714 if (new_asoc->peer.adaption_ind) {
715 ev = sctp_ulpevent_make_adaption_indication(new_asoc,
716 GFP_ATOMIC);
717 if (!ev)
718 goto nomem_ev;
719
720 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
721 SCTP_ULPEVENT(ev));
722 }
723
724 return SCTP_DISPOSITION_CONSUME;
725
726nomem_ev:
727 sctp_chunk_free(repl);
728nomem_repl:
729nomem_init:
730 sctp_association_free(new_asoc);
731nomem:
732 return SCTP_DISPOSITION_NOMEM;
733}
734
735/*
736 * Respond to a normal COOKIE ACK chunk.
737 * We are the side that is being asked for an association.
738 *
739 * RFC 2960 5.1 Normal Establishment of an Association
740 *
741 * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the
742 * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie
743 * timer. It may also notify its ULP about the successful
744 * establishment of the association with a Communication Up
745 * notification (see Section 10).
746 *
747 * Verification Tag:
748 * Inputs
749 * (endpoint, asoc, chunk)
750 *
751 * Outputs
752 * (asoc, reply_msg, msg_up, timers, counters)
753 *
754 * The return value is the disposition of the chunk.
755 */
756sctp_disposition_t sctp_sf_do_5_1E_ca(const struct sctp_endpoint *ep,
757 const struct sctp_association *asoc,
758 const sctp_subtype_t type, void *arg,
759 sctp_cmd_seq_t *commands)
760{
761 struct sctp_chunk *chunk = arg;
762 struct sctp_ulpevent *ev;
763
764 if (!sctp_vtag_verify(chunk, asoc))
765 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
766
767 /* Verify that the chunk length for the COOKIE-ACK is OK.
768 * If we don't do this, any bundled chunks may be junked.
769 */
770 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
771 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
772 commands);
773
774 /* Reset init error count upon receipt of COOKIE-ACK,
775 * to avoid problems with the managemement of this
776 * counter in stale cookie situations when a transition back
777 * from the COOKIE-ECHOED state to the COOKIE-WAIT
778 * state is performed.
779 */
Frank Filz3f7a87d2005-06-20 13:14:57 -0700780 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
Linus Torvalds1da177e2005-04-16 15:20:36 -0700781
782 /* RFC 2960 5.1 Normal Establishment of an Association
783 *
784 * E) Upon reception of the COOKIE ACK, endpoint "A" will move
785 * from the COOKIE-ECHOED state to the ESTABLISHED state,
786 * stopping the T1-cookie timer.
787 */
788 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
789 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
790 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
791 SCTP_STATE(SCTP_STATE_ESTABLISHED));
792 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
793 SCTP_INC_STATS(SCTP_MIB_ACTIVEESTABS);
794 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
795 if (asoc->autoclose)
796 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
797 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
798 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
799
800 /* It may also notify its ULP about the successful
801 * establishment of the association with a Communication Up
802 * notification (see Section 10).
803 */
804 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP,
805 0, asoc->c.sinit_num_ostreams,
806 asoc->c.sinit_max_instreams,
807 GFP_ATOMIC);
808
809 if (!ev)
810 goto nomem;
811
812 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
813
814 /* Sockets API Draft Section 5.3.1.6
815 * When a peer sends a Adaption Layer Indication parameter , SCTP
816 * delivers this notification to inform the application that of the
817 * peers requested adaption layer.
818 */
819 if (asoc->peer.adaption_ind) {
820 ev = sctp_ulpevent_make_adaption_indication(asoc, GFP_ATOMIC);
821 if (!ev)
822 goto nomem;
823
824 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
825 SCTP_ULPEVENT(ev));
826 }
827
828 return SCTP_DISPOSITION_CONSUME;
829nomem:
830 return SCTP_DISPOSITION_NOMEM;
831}
832
833/* Generate and sendout a heartbeat packet. */
834static sctp_disposition_t sctp_sf_heartbeat(const struct sctp_endpoint *ep,
835 const struct sctp_association *asoc,
836 const sctp_subtype_t type,
837 void *arg,
838 sctp_cmd_seq_t *commands)
839{
840 struct sctp_transport *transport = (struct sctp_transport *) arg;
841 struct sctp_chunk *reply;
842 sctp_sender_hb_info_t hbinfo;
843 size_t paylen = 0;
844
845 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO;
846 hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t));
847 hbinfo.daddr = transport->ipaddr;
848 hbinfo.sent_at = jiffies;
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700849 hbinfo.hb_nonce = transport->hb_nonce;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700850
851 /* Send a heartbeat to our peer. */
852 paylen = sizeof(sctp_sender_hb_info_t);
853 reply = sctp_make_heartbeat(asoc, transport, &hbinfo, paylen);
854 if (!reply)
855 return SCTP_DISPOSITION_NOMEM;
856
857 /* Set rto_pending indicating that an RTT measurement
858 * is started with this heartbeat chunk.
859 */
860 sctp_add_cmd_sf(commands, SCTP_CMD_RTO_PENDING,
861 SCTP_TRANSPORT(transport));
862
863 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
864 return SCTP_DISPOSITION_CONSUME;
865}
866
867/* Generate a HEARTBEAT packet on the given transport. */
868sctp_disposition_t sctp_sf_sendbeat_8_3(const struct sctp_endpoint *ep,
869 const struct sctp_association *asoc,
870 const sctp_subtype_t type,
871 void *arg,
872 sctp_cmd_seq_t *commands)
873{
874 struct sctp_transport *transport = (struct sctp_transport *) arg;
875
Vlad Yaseviche2c2fc22006-01-30 16:00:40 -0800876 if (asoc->overall_error_count >= asoc->max_retrans) {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700877 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
878 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700879 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
880 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
881 SCTP_U32(SCTP_ERROR_NO_ERROR));
882 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
883 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
884 return SCTP_DISPOSITION_DELETE_TCB;
885 }
886
887 /* Section 3.3.5.
888 * The Sender-specific Heartbeat Info field should normally include
889 * information about the sender's current time when this HEARTBEAT
890 * chunk is sent and the destination transport address to which this
891 * HEARTBEAT is sent (see Section 8.3).
892 */
893
Frank Filz52ccb8e2005-12-22 11:36:46 -0800894 if (transport->param_flags & SPP_HB_ENABLE) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700895 if (SCTP_DISPOSITION_NOMEM ==
896 sctp_sf_heartbeat(ep, asoc, type, arg,
897 commands))
898 return SCTP_DISPOSITION_NOMEM;
899 /* Set transport error counter and association error counter
900 * when sending heartbeat.
901 */
902 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_RESET,
903 SCTP_TRANSPORT(transport));
904 }
905 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMER_UPDATE,
906 SCTP_TRANSPORT(transport));
907
908 return SCTP_DISPOSITION_CONSUME;
909}
910
911/*
912 * Process an heartbeat request.
913 *
914 * Section: 8.3 Path Heartbeat
915 * The receiver of the HEARTBEAT should immediately respond with a
916 * HEARTBEAT ACK that contains the Heartbeat Information field copied
917 * from the received HEARTBEAT chunk.
918 *
919 * Verification Tag: 8.5 Verification Tag [Normal verification]
920 * When receiving an SCTP packet, the endpoint MUST ensure that the
921 * value in the Verification Tag field of the received SCTP packet
922 * matches its own Tag. If the received Verification Tag value does not
923 * match the receiver's own tag value, the receiver shall silently
924 * discard the packet and shall not process it any further except for
925 * those cases listed in Section 8.5.1 below.
926 *
927 * Inputs
928 * (endpoint, asoc, chunk)
929 *
930 * Outputs
931 * (asoc, reply_msg, msg_up, timers, counters)
932 *
933 * The return value is the disposition of the chunk.
934 */
935sctp_disposition_t sctp_sf_beat_8_3(const struct sctp_endpoint *ep,
936 const struct sctp_association *asoc,
937 const sctp_subtype_t type,
938 void *arg,
939 sctp_cmd_seq_t *commands)
940{
941 struct sctp_chunk *chunk = arg;
942 struct sctp_chunk *reply;
943 size_t paylen = 0;
944
945 if (!sctp_vtag_verify(chunk, asoc))
946 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
947
948 /* Make sure that the HEARTBEAT chunk has a valid length. */
949 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t)))
950 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
951 commands);
952
953 /* 8.3 The receiver of the HEARTBEAT should immediately
954 * respond with a HEARTBEAT ACK that contains the Heartbeat
955 * Information field copied from the received HEARTBEAT chunk.
956 */
957 chunk->subh.hb_hdr = (sctp_heartbeathdr_t *) chunk->skb->data;
958 paylen = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
Sridhar Samudrala62b08082006-05-05 17:04:43 -0700959 if (!pskb_pull(chunk->skb, paylen))
960 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700961
962 reply = sctp_make_heartbeat_ack(asoc, chunk,
963 chunk->subh.hb_hdr, paylen);
964 if (!reply)
965 goto nomem;
966
967 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
968 return SCTP_DISPOSITION_CONSUME;
969
970nomem:
971 return SCTP_DISPOSITION_NOMEM;
972}
973
974/*
975 * Process the returning HEARTBEAT ACK.
976 *
977 * Section: 8.3 Path Heartbeat
978 * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT
979 * should clear the error counter of the destination transport
980 * address to which the HEARTBEAT was sent, and mark the destination
981 * transport address as active if it is not so marked. The endpoint may
982 * optionally report to the upper layer when an inactive destination
983 * address is marked as active due to the reception of the latest
984 * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also
985 * clear the association overall error count as well (as defined
986 * in section 8.1).
987 *
988 * The receiver of the HEARTBEAT ACK should also perform an RTT
989 * measurement for that destination transport address using the time
990 * value carried in the HEARTBEAT ACK chunk.
991 *
992 * Verification Tag: 8.5 Verification Tag [Normal verification]
993 *
994 * Inputs
995 * (endpoint, asoc, chunk)
996 *
997 * Outputs
998 * (asoc, reply_msg, msg_up, timers, counters)
999 *
1000 * The return value is the disposition of the chunk.
1001 */
1002sctp_disposition_t sctp_sf_backbeat_8_3(const struct sctp_endpoint *ep,
1003 const struct sctp_association *asoc,
1004 const sctp_subtype_t type,
1005 void *arg,
1006 sctp_cmd_seq_t *commands)
1007{
1008 struct sctp_chunk *chunk = arg;
1009 union sctp_addr from_addr;
1010 struct sctp_transport *link;
1011 sctp_sender_hb_info_t *hbinfo;
1012 unsigned long max_interval;
1013
1014 if (!sctp_vtag_verify(chunk, asoc))
1015 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1016
1017 /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */
1018 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t)))
1019 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1020 commands);
1021
1022 hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
Vladislav Yasevicha6012662006-05-19 14:25:53 -07001023 /* Make sure that the length of the parameter is what we expect */
1024 if (ntohs(hbinfo->param_hdr.length) !=
1025 sizeof(sctp_sender_hb_info_t)) {
1026 return SCTP_DISPOSITION_DISCARD;
1027 }
1028
Linus Torvalds1da177e2005-04-16 15:20:36 -07001029 from_addr = hbinfo->daddr;
1030 link = sctp_assoc_lookup_paddr(asoc, &from_addr);
1031
1032 /* This should never happen, but lets log it if so. */
Frank Filz3f7a87d2005-06-20 13:14:57 -07001033 if (unlikely(!link)) {
1034 if (from_addr.sa.sa_family == AF_INET6) {
1035 printk(KERN_WARNING
1036 "%s association %p could not find address "
Joe Perches46b86a22006-01-13 14:29:07 -08001037 NIP6_FMT "\n",
Frank Filz3f7a87d2005-06-20 13:14:57 -07001038 __FUNCTION__,
1039 asoc,
1040 NIP6(from_addr.v6.sin6_addr));
1041 } else {
1042 printk(KERN_WARNING
1043 "%s association %p could not find address "
Joe Perches46b86a22006-01-13 14:29:07 -08001044 NIPQUAD_FMT "\n",
Frank Filz3f7a87d2005-06-20 13:14:57 -07001045 __FUNCTION__,
1046 asoc,
1047 NIPQUAD(from_addr.v4.sin_addr.s_addr));
1048 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001049 return SCTP_DISPOSITION_DISCARD;
1050 }
1051
Sridhar Samudralaad8fec12006-07-21 14:48:50 -07001052 /* Validate the 64-bit random nonce. */
1053 if (hbinfo->hb_nonce != link->hb_nonce)
1054 return SCTP_DISPOSITION_DISCARD;
1055
Frank Filz52ccb8e2005-12-22 11:36:46 -08001056 max_interval = link->hbinterval + link->rto;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001057
1058 /* Check if the timestamp looks valid. */
1059 if (time_after(hbinfo->sent_at, jiffies) ||
1060 time_after(jiffies, hbinfo->sent_at + max_interval)) {
1061 SCTP_DEBUG_PRINTK("%s: HEARTBEAT ACK with invalid timestamp"
1062 "received for transport: %p\n",
1063 __FUNCTION__, link);
1064 return SCTP_DISPOSITION_DISCARD;
1065 }
1066
1067 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of
1068 * the HEARTBEAT should clear the error counter of the
1069 * destination transport address to which the HEARTBEAT was
1070 * sent and mark the destination transport address as active if
1071 * it is not so marked.
1072 */
1073 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_ON, SCTP_TRANSPORT(link));
1074
1075 return SCTP_DISPOSITION_CONSUME;
1076}
1077
1078/* Helper function to send out an abort for the restart
1079 * condition.
1080 */
1081static int sctp_sf_send_restart_abort(union sctp_addr *ssa,
1082 struct sctp_chunk *init,
1083 sctp_cmd_seq_t *commands)
1084{
1085 int len;
1086 struct sctp_packet *pkt;
1087 union sctp_addr_param *addrparm;
1088 struct sctp_errhdr *errhdr;
1089 struct sctp_endpoint *ep;
1090 char buffer[sizeof(struct sctp_errhdr)+sizeof(union sctp_addr_param)];
1091 struct sctp_af *af = sctp_get_af_specific(ssa->v4.sin_family);
1092
1093 /* Build the error on the stack. We are way to malloc crazy
1094 * throughout the code today.
1095 */
1096 errhdr = (struct sctp_errhdr *)buffer;
1097 addrparm = (union sctp_addr_param *)errhdr->variable;
1098
1099 /* Copy into a parm format. */
1100 len = af->to_addr_param(ssa, addrparm);
1101 len += sizeof(sctp_errhdr_t);
1102
1103 errhdr->cause = SCTP_ERROR_RESTART;
1104 errhdr->length = htons(len);
1105
1106 /* Assign to the control socket. */
1107 ep = sctp_sk((sctp_get_ctl_sock()))->ep;
1108
1109 /* Association is NULL since this may be a restart attack and we
1110 * want to send back the attacker's vtag.
1111 */
1112 pkt = sctp_abort_pkt_new(ep, NULL, init, errhdr, len);
1113
1114 if (!pkt)
1115 goto out;
1116 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, SCTP_PACKET(pkt));
1117
1118 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
1119
1120 /* Discard the rest of the inbound packet. */
1121 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
1122
1123out:
1124 /* Even if there is no memory, treat as a failure so
1125 * the packet will get dropped.
1126 */
1127 return 0;
1128}
1129
1130/* A restart is occurring, check to make sure no new addresses
1131 * are being added as we may be under a takeover attack.
1132 */
1133static int sctp_sf_check_restart_addrs(const struct sctp_association *new_asoc,
1134 const struct sctp_association *asoc,
1135 struct sctp_chunk *init,
1136 sctp_cmd_seq_t *commands)
1137{
1138 struct sctp_transport *new_addr, *addr;
1139 struct list_head *pos, *pos2;
1140 int found;
1141
1142 /* Implementor's Guide - Sectin 5.2.2
1143 * ...
1144 * Before responding the endpoint MUST check to see if the
1145 * unexpected INIT adds new addresses to the association. If new
1146 * addresses are added to the association, the endpoint MUST respond
1147 * with an ABORT..
1148 */
1149
1150 /* Search through all current addresses and make sure
1151 * we aren't adding any new ones.
1152 */
1153 new_addr = NULL;
1154 found = 0;
1155
1156 list_for_each(pos, &new_asoc->peer.transport_addr_list) {
1157 new_addr = list_entry(pos, struct sctp_transport, transports);
1158 found = 0;
1159 list_for_each(pos2, &asoc->peer.transport_addr_list) {
1160 addr = list_entry(pos2, struct sctp_transport,
1161 transports);
1162 if (sctp_cmp_addr_exact(&new_addr->ipaddr,
1163 &addr->ipaddr)) {
1164 found = 1;
1165 break;
1166 }
1167 }
1168 if (!found)
1169 break;
1170 }
1171
1172 /* If a new address was added, ABORT the sender. */
1173 if (!found && new_addr) {
1174 sctp_sf_send_restart_abort(&new_addr->ipaddr, init, commands);
1175 }
1176
1177 /* Return success if all addresses were found. */
1178 return found;
1179}
1180
1181/* Populate the verification/tie tags based on overlapping INIT
1182 * scenario.
1183 *
1184 * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state.
1185 */
1186static void sctp_tietags_populate(struct sctp_association *new_asoc,
1187 const struct sctp_association *asoc)
1188{
1189 switch (asoc->state) {
1190
1191 /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */
1192
1193 case SCTP_STATE_COOKIE_WAIT:
1194 new_asoc->c.my_vtag = asoc->c.my_vtag;
1195 new_asoc->c.my_ttag = asoc->c.my_vtag;
1196 new_asoc->c.peer_ttag = 0;
1197 break;
1198
1199 case SCTP_STATE_COOKIE_ECHOED:
1200 new_asoc->c.my_vtag = asoc->c.my_vtag;
1201 new_asoc->c.my_ttag = asoc->c.my_vtag;
1202 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1203 break;
1204
1205 /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED,
1206 * COOKIE-WAIT and SHUTDOWN-ACK-SENT
1207 */
1208 default:
1209 new_asoc->c.my_ttag = asoc->c.my_vtag;
1210 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1211 break;
1212 };
1213
1214 /* Other parameters for the endpoint SHOULD be copied from the
1215 * existing parameters of the association (e.g. number of
1216 * outbound streams) into the INIT ACK and cookie.
1217 */
1218 new_asoc->rwnd = asoc->rwnd;
1219 new_asoc->c.sinit_num_ostreams = asoc->c.sinit_num_ostreams;
1220 new_asoc->c.sinit_max_instreams = asoc->c.sinit_max_instreams;
1221 new_asoc->c.initial_tsn = asoc->c.initial_tsn;
1222}
1223
1224/*
1225 * Compare vtag/tietag values to determine unexpected COOKIE-ECHO
1226 * handling action.
1227 *
1228 * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists.
1229 *
1230 * Returns value representing action to be taken. These action values
1231 * correspond to Action/Description values in RFC 2960, Table 2.
1232 */
1233static char sctp_tietags_compare(struct sctp_association *new_asoc,
1234 const struct sctp_association *asoc)
1235{
1236 /* In this case, the peer may have restarted. */
1237 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1238 (asoc->c.peer_vtag != new_asoc->c.peer_vtag) &&
1239 (asoc->c.my_vtag == new_asoc->c.my_ttag) &&
1240 (asoc->c.peer_vtag == new_asoc->c.peer_ttag))
1241 return 'A';
1242
1243 /* Collision case B. */
1244 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1245 ((asoc->c.peer_vtag != new_asoc->c.peer_vtag) ||
1246 (0 == asoc->c.peer_vtag))) {
1247 return 'B';
1248 }
1249
1250 /* Collision case D. */
1251 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1252 (asoc->c.peer_vtag == new_asoc->c.peer_vtag))
1253 return 'D';
1254
1255 /* Collision case C. */
1256 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1257 (asoc->c.peer_vtag == new_asoc->c.peer_vtag) &&
1258 (0 == new_asoc->c.my_ttag) &&
1259 (0 == new_asoc->c.peer_ttag))
1260 return 'C';
1261
1262 /* No match to any of the special cases; discard this packet. */
1263 return 'E';
1264}
1265
1266/* Common helper routine for both duplicate and simulataneous INIT
1267 * chunk handling.
1268 */
1269static sctp_disposition_t sctp_sf_do_unexpected_init(
1270 const struct sctp_endpoint *ep,
1271 const struct sctp_association *asoc,
1272 const sctp_subtype_t type,
1273 void *arg, sctp_cmd_seq_t *commands)
1274{
1275 sctp_disposition_t retval;
1276 struct sctp_chunk *chunk = arg;
1277 struct sctp_chunk *repl;
1278 struct sctp_association *new_asoc;
1279 struct sctp_chunk *err_chunk;
1280 struct sctp_packet *packet;
1281 sctp_unrecognized_param_t *unk_param;
1282 int len;
1283
1284 /* 6.10 Bundling
1285 * An endpoint MUST NOT bundle INIT, INIT ACK or
1286 * SHUTDOWN COMPLETE with any other chunks.
1287 *
1288 * IG Section 2.11.2
1289 * Furthermore, we require that the receiver of an INIT chunk MUST
1290 * enforce these rules by silently discarding an arriving packet
1291 * with an INIT chunk that is bundled with other chunks.
1292 */
1293 if (!chunk->singleton)
1294 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1295
1296 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
1297 * Tag.
1298 */
1299 if (chunk->sctp_hdr->vtag != 0)
1300 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
1301
1302 /* Make sure that the INIT chunk has a valid length.
1303 * In this case, we generate a protocol violation since we have
1304 * an association established.
1305 */
1306 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
1307 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1308 commands);
1309 /* Grab the INIT header. */
1310 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
1311
1312 /* Tag the variable length parameters. */
1313 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
1314
1315 /* Verify the INIT chunk before processing it. */
1316 err_chunk = NULL;
1317 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
1318 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
1319 &err_chunk)) {
1320 /* This chunk contains fatal error. It is to be discarded.
1321 * Send an ABORT, with causes if there is any.
1322 */
1323 if (err_chunk) {
1324 packet = sctp_abort_pkt_new(ep, asoc, arg,
1325 (__u8 *)(err_chunk->chunk_hdr) +
1326 sizeof(sctp_chunkhdr_t),
1327 ntohs(err_chunk->chunk_hdr->length) -
1328 sizeof(sctp_chunkhdr_t));
1329
1330 if (packet) {
1331 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
1332 SCTP_PACKET(packet));
1333 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
1334 retval = SCTP_DISPOSITION_CONSUME;
1335 } else {
1336 retval = SCTP_DISPOSITION_NOMEM;
1337 }
1338 goto cleanup;
1339 } else {
1340 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg,
1341 commands);
1342 }
1343 }
1344
1345 /*
1346 * Other parameters for the endpoint SHOULD be copied from the
1347 * existing parameters of the association (e.g. number of
1348 * outbound streams) into the INIT ACK and cookie.
1349 * FIXME: We are copying parameters from the endpoint not the
1350 * association.
1351 */
1352 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
1353 if (!new_asoc)
1354 goto nomem;
1355
1356 /* In the outbound INIT ACK the endpoint MUST copy its current
1357 * Verification Tag and Peers Verification tag into a reserved
1358 * place (local tie-tag and per tie-tag) within the state cookie.
1359 */
1360 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
1361 sctp_source(chunk),
1362 (sctp_init_chunk_t *)chunk->chunk_hdr,
1363 GFP_ATOMIC)) {
1364 retval = SCTP_DISPOSITION_NOMEM;
1365 goto nomem_init;
1366 }
1367
1368 /* Make sure no new addresses are being added during the
1369 * restart. Do not do this check for COOKIE-WAIT state,
1370 * since there are no peer addresses to check against.
1371 * Upon return an ABORT will have been sent if needed.
1372 */
1373 if (!sctp_state(asoc, COOKIE_WAIT)) {
1374 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk,
1375 commands)) {
1376 retval = SCTP_DISPOSITION_CONSUME;
1377 goto cleanup_asoc;
1378 }
1379 }
1380
1381 sctp_tietags_populate(new_asoc, asoc);
1382
1383 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
1384
1385 /* If there are errors need to be reported for unknown parameters,
1386 * make sure to reserve enough room in the INIT ACK for them.
1387 */
1388 len = 0;
1389 if (err_chunk) {
1390 len = ntohs(err_chunk->chunk_hdr->length) -
1391 sizeof(sctp_chunkhdr_t);
1392 }
1393
1394 if (sctp_assoc_set_bind_addr_from_ep(new_asoc, GFP_ATOMIC) < 0)
1395 goto nomem;
1396
1397 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
1398 if (!repl)
1399 goto nomem;
1400
1401 /* If there are errors need to be reported for unknown parameters,
1402 * include them in the outgoing INIT ACK as "Unrecognized parameter"
1403 * parameter.
1404 */
1405 if (err_chunk) {
1406 /* Get the "Unrecognized parameter" parameter(s) out of the
1407 * ERROR chunk generated by sctp_verify_init(). Since the
1408 * error cause code for "unknown parameter" and the
1409 * "Unrecognized parameter" type is the same, we can
1410 * construct the parameters in INIT ACK by copying the
1411 * ERROR causes over.
1412 */
1413 unk_param = (sctp_unrecognized_param_t *)
1414 ((__u8 *)(err_chunk->chunk_hdr) +
1415 sizeof(sctp_chunkhdr_t));
1416 /* Replace the cause code with the "Unrecognized parameter"
1417 * parameter type.
1418 */
1419 sctp_addto_chunk(repl, len, unk_param);
1420 }
1421
1422 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
1423 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1424
1425 /*
1426 * Note: After sending out INIT ACK with the State Cookie parameter,
1427 * "Z" MUST NOT allocate any resources for this new association.
1428 * Otherwise, "Z" will be vulnerable to resource attacks.
1429 */
1430 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
1431 retval = SCTP_DISPOSITION_CONSUME;
1432
1433cleanup:
1434 if (err_chunk)
1435 sctp_chunk_free(err_chunk);
1436 return retval;
1437nomem:
1438 retval = SCTP_DISPOSITION_NOMEM;
1439 goto cleanup;
1440nomem_init:
1441cleanup_asoc:
1442 sctp_association_free(new_asoc);
1443 goto cleanup;
1444}
1445
1446/*
1447 * Handle simultanous INIT.
1448 * This means we started an INIT and then we got an INIT request from
1449 * our peer.
1450 *
1451 * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B)
1452 * This usually indicates an initialization collision, i.e., each
1453 * endpoint is attempting, at about the same time, to establish an
1454 * association with the other endpoint.
1455 *
1456 * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an
1457 * endpoint MUST respond with an INIT ACK using the same parameters it
1458 * sent in its original INIT chunk (including its Verification Tag,
1459 * unchanged). These original parameters are combined with those from the
1460 * newly received INIT chunk. The endpoint shall also generate a State
1461 * Cookie with the INIT ACK. The endpoint uses the parameters sent in its
1462 * INIT to calculate the State Cookie.
1463 *
1464 * After that, the endpoint MUST NOT change its state, the T1-init
1465 * timer shall be left running and the corresponding TCB MUST NOT be
1466 * destroyed. The normal procedures for handling State Cookies when
1467 * a TCB exists will resolve the duplicate INITs to a single association.
1468 *
1469 * For an endpoint that is in the COOKIE-ECHOED state it MUST populate
1470 * its Tie-Tags with the Tag information of itself and its peer (see
1471 * section 5.2.2 for a description of the Tie-Tags).
1472 *
1473 * Verification Tag: Not explicit, but an INIT can not have a valid
1474 * verification tag, so we skip the check.
1475 *
1476 * Inputs
1477 * (endpoint, asoc, chunk)
1478 *
1479 * Outputs
1480 * (asoc, reply_msg, msg_up, timers, counters)
1481 *
1482 * The return value is the disposition of the chunk.
1483 */
1484sctp_disposition_t sctp_sf_do_5_2_1_siminit(const struct sctp_endpoint *ep,
1485 const struct sctp_association *asoc,
1486 const sctp_subtype_t type,
1487 void *arg,
1488 sctp_cmd_seq_t *commands)
1489{
1490 /* Call helper to do the real work for both simulataneous and
1491 * duplicate INIT chunk handling.
1492 */
1493 return sctp_sf_do_unexpected_init(ep, asoc, type, arg, commands);
1494}
1495
1496/*
1497 * Handle duplicated INIT messages. These are usually delayed
1498 * restransmissions.
1499 *
1500 * Section: 5.2.2 Unexpected INIT in States Other than CLOSED,
1501 * COOKIE-ECHOED and COOKIE-WAIT
1502 *
1503 * Unless otherwise stated, upon reception of an unexpected INIT for
1504 * this association, the endpoint shall generate an INIT ACK with a
1505 * State Cookie. In the outbound INIT ACK the endpoint MUST copy its
1506 * current Verification Tag and peer's Verification Tag into a reserved
1507 * place within the state cookie. We shall refer to these locations as
1508 * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet
1509 * containing this INIT ACK MUST carry a Verification Tag value equal to
1510 * the Initiation Tag found in the unexpected INIT. And the INIT ACK
1511 * MUST contain a new Initiation Tag (randomly generated see Section
1512 * 5.3.1). Other parameters for the endpoint SHOULD be copied from the
1513 * existing parameters of the association (e.g. number of outbound
1514 * streams) into the INIT ACK and cookie.
1515 *
1516 * After sending out the INIT ACK, the endpoint shall take no further
1517 * actions, i.e., the existing association, including its current state,
1518 * and the corresponding TCB MUST NOT be changed.
1519 *
1520 * Note: Only when a TCB exists and the association is not in a COOKIE-
1521 * WAIT state are the Tie-Tags populated. For a normal association INIT
1522 * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be
1523 * set to 0 (indicating that no previous TCB existed). The INIT ACK and
1524 * State Cookie are populated as specified in section 5.2.1.
1525 *
1526 * Verification Tag: Not specified, but an INIT has no way of knowing
1527 * what the verification tag could be, so we ignore it.
1528 *
1529 * Inputs
1530 * (endpoint, asoc, chunk)
1531 *
1532 * Outputs
1533 * (asoc, reply_msg, msg_up, timers, counters)
1534 *
1535 * The return value is the disposition of the chunk.
1536 */
1537sctp_disposition_t sctp_sf_do_5_2_2_dupinit(const struct sctp_endpoint *ep,
1538 const struct sctp_association *asoc,
1539 const sctp_subtype_t type,
1540 void *arg,
1541 sctp_cmd_seq_t *commands)
1542{
1543 /* Call helper to do the real work for both simulataneous and
1544 * duplicate INIT chunk handling.
1545 */
1546 return sctp_sf_do_unexpected_init(ep, asoc, type, arg, commands);
1547}
1548
1549
1550
1551/* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A')
1552 *
1553 * Section 5.2.4
1554 * A) In this case, the peer may have restarted.
1555 */
1556static sctp_disposition_t sctp_sf_do_dupcook_a(const struct sctp_endpoint *ep,
1557 const struct sctp_association *asoc,
1558 struct sctp_chunk *chunk,
1559 sctp_cmd_seq_t *commands,
1560 struct sctp_association *new_asoc)
1561{
1562 sctp_init_chunk_t *peer_init;
1563 struct sctp_ulpevent *ev;
1564 struct sctp_chunk *repl;
1565 struct sctp_chunk *err;
1566 sctp_disposition_t disposition;
1567
1568 /* new_asoc is a brand-new association, so these are not yet
1569 * side effects--it is safe to run them here.
1570 */
1571 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1572
1573 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
1574 sctp_source(chunk), peer_init,
1575 GFP_ATOMIC))
1576 goto nomem;
1577
1578 /* Make sure no new addresses are being added during the
1579 * restart. Though this is a pretty complicated attack
1580 * since you'd have to get inside the cookie.
1581 */
1582 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk, commands)) {
1583 return SCTP_DISPOSITION_CONSUME;
1584 }
1585
1586 /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes
1587 * the peer has restarted (Action A), it MUST NOT setup a new
1588 * association but instead resend the SHUTDOWN ACK and send an ERROR
1589 * chunk with a "Cookie Received while Shutting Down" error cause to
1590 * its peer.
1591 */
1592 if (sctp_state(asoc, SHUTDOWN_ACK_SENT)) {
1593 disposition = sctp_sf_do_9_2_reshutack(ep, asoc,
1594 SCTP_ST_CHUNK(chunk->chunk_hdr->type),
1595 chunk, commands);
1596 if (SCTP_DISPOSITION_NOMEM == disposition)
1597 goto nomem;
1598
1599 err = sctp_make_op_error(asoc, chunk,
1600 SCTP_ERROR_COOKIE_IN_SHUTDOWN,
1601 NULL, 0);
1602 if (err)
1603 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1604 SCTP_CHUNK(err));
1605
1606 return SCTP_DISPOSITION_CONSUME;
1607 }
1608
1609 /* For now, fail any unsent/unacked data. Consider the optional
1610 * choice of resending of this data.
1611 */
1612 sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_OUTQUEUE, SCTP_NULL());
1613
1614 /* Update the content of current association. */
1615 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1616
1617 repl = sctp_make_cookie_ack(new_asoc, chunk);
1618 if (!repl)
1619 goto nomem;
1620
1621 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1622
1623 /* Report association restart to upper layer. */
1624 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_RESTART, 0,
1625 new_asoc->c.sinit_num_ostreams,
1626 new_asoc->c.sinit_max_instreams,
1627 GFP_ATOMIC);
1628 if (!ev)
1629 goto nomem_ev;
1630
1631 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
1632 return SCTP_DISPOSITION_CONSUME;
1633
1634nomem_ev:
1635 sctp_chunk_free(repl);
1636nomem:
1637 return SCTP_DISPOSITION_NOMEM;
1638}
1639
1640/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B')
1641 *
1642 * Section 5.2.4
1643 * B) In this case, both sides may be attempting to start an association
1644 * at about the same time but the peer endpoint started its INIT
1645 * after responding to the local endpoint's INIT
1646 */
1647/* This case represents an initialization collision. */
1648static sctp_disposition_t sctp_sf_do_dupcook_b(const struct sctp_endpoint *ep,
1649 const struct sctp_association *asoc,
1650 struct sctp_chunk *chunk,
1651 sctp_cmd_seq_t *commands,
1652 struct sctp_association *new_asoc)
1653{
1654 sctp_init_chunk_t *peer_init;
1655 struct sctp_ulpevent *ev;
1656 struct sctp_chunk *repl;
1657
1658 /* new_asoc is a brand-new association, so these are not yet
1659 * side effects--it is safe to run them here.
1660 */
1661 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1662 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
1663 sctp_source(chunk), peer_init,
1664 GFP_ATOMIC))
1665 goto nomem;
1666
1667 /* Update the content of current association. */
1668 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1669 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1670 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1671 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
1672 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
1673
1674 repl = sctp_make_cookie_ack(new_asoc, chunk);
1675 if (!repl)
1676 goto nomem;
1677
1678 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1679 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
1680
1681 /* RFC 2960 5.1 Normal Establishment of an Association
1682 *
1683 * D) IMPLEMENTATION NOTE: An implementation may choose to
1684 * send the Communication Up notification to the SCTP user
1685 * upon reception of a valid COOKIE ECHO chunk.
1686 */
1687 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP, 0,
1688 new_asoc->c.sinit_num_ostreams,
1689 new_asoc->c.sinit_max_instreams,
1690 GFP_ATOMIC);
1691 if (!ev)
1692 goto nomem_ev;
1693
1694 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
1695
1696 /* Sockets API Draft Section 5.3.1.6
1697 * When a peer sends a Adaption Layer Indication parameter , SCTP
1698 * delivers this notification to inform the application that of the
1699 * peers requested adaption layer.
1700 */
1701 if (asoc->peer.adaption_ind) {
1702 ev = sctp_ulpevent_make_adaption_indication(asoc, GFP_ATOMIC);
1703 if (!ev)
1704 goto nomem_ev;
1705
1706 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1707 SCTP_ULPEVENT(ev));
1708 }
1709
1710 return SCTP_DISPOSITION_CONSUME;
1711
1712nomem_ev:
1713 sctp_chunk_free(repl);
1714nomem:
1715 return SCTP_DISPOSITION_NOMEM;
1716}
1717
1718/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C')
1719 *
1720 * Section 5.2.4
1721 * C) In this case, the local endpoint's cookie has arrived late.
1722 * Before it arrived, the local endpoint sent an INIT and received an
1723 * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag
1724 * but a new tag of its own.
1725 */
1726/* This case represents an initialization collision. */
1727static sctp_disposition_t sctp_sf_do_dupcook_c(const struct sctp_endpoint *ep,
1728 const struct sctp_association *asoc,
1729 struct sctp_chunk *chunk,
1730 sctp_cmd_seq_t *commands,
1731 struct sctp_association *new_asoc)
1732{
1733 /* The cookie should be silently discarded.
1734 * The endpoint SHOULD NOT change states and should leave
1735 * any timers running.
1736 */
1737 return SCTP_DISPOSITION_DISCARD;
1738}
1739
1740/* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D')
1741 *
1742 * Section 5.2.4
1743 *
1744 * D) When both local and remote tags match the endpoint should always
1745 * enter the ESTABLISHED state, if it has not already done so.
1746 */
1747/* This case represents an initialization collision. */
1748static sctp_disposition_t sctp_sf_do_dupcook_d(const struct sctp_endpoint *ep,
1749 const struct sctp_association *asoc,
1750 struct sctp_chunk *chunk,
1751 sctp_cmd_seq_t *commands,
1752 struct sctp_association *new_asoc)
1753{
1754 struct sctp_ulpevent *ev = NULL;
1755 struct sctp_chunk *repl;
1756
1757 /* Clarification from Implementor's Guide:
1758 * D) When both local and remote tags match the endpoint should
1759 * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state.
1760 * It should stop any cookie timer that may be running and send
1761 * a COOKIE ACK.
1762 */
1763
1764 /* Don't accidentally move back into established state. */
1765 if (asoc->state < SCTP_STATE_ESTABLISHED) {
1766 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1767 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1768 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1769 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1770 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
1771 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START,
1772 SCTP_NULL());
1773
1774 /* RFC 2960 5.1 Normal Establishment of an Association
1775 *
1776 * D) IMPLEMENTATION NOTE: An implementation may choose
1777 * to send the Communication Up notification to the
1778 * SCTP user upon reception of a valid COOKIE
1779 * ECHO chunk.
1780 */
1781 ev = sctp_ulpevent_make_assoc_change(new_asoc, 0,
1782 SCTP_COMM_UP, 0,
1783 new_asoc->c.sinit_num_ostreams,
1784 new_asoc->c.sinit_max_instreams,
1785 GFP_ATOMIC);
1786 if (!ev)
1787 goto nomem;
1788 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1789 SCTP_ULPEVENT(ev));
1790
1791 /* Sockets API Draft Section 5.3.1.6
1792 * When a peer sends a Adaption Layer Indication parameter,
1793 * SCTP delivers this notification to inform the application
1794 * that of the peers requested adaption layer.
1795 */
1796 if (new_asoc->peer.adaption_ind) {
1797 ev = sctp_ulpevent_make_adaption_indication(new_asoc,
1798 GFP_ATOMIC);
1799 if (!ev)
1800 goto nomem;
1801
1802 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1803 SCTP_ULPEVENT(ev));
1804 }
1805 }
1806 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
1807
1808 repl = sctp_make_cookie_ack(new_asoc, chunk);
1809 if (!repl)
1810 goto nomem;
1811
1812 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:
1818 if (ev)
1819 sctp_ulpevent_free(ev);
1820 return SCTP_DISPOSITION_NOMEM;
1821}
1822
1823/*
1824 * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying
1825 * chunk was retransmitted and then delayed in the network.
1826 *
1827 * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists
1828 *
1829 * Verification Tag: None. Do cookie validation.
1830 *
1831 * Inputs
1832 * (endpoint, asoc, chunk)
1833 *
1834 * Outputs
1835 * (asoc, reply_msg, msg_up, timers, counters)
1836 *
1837 * The return value is the disposition of the chunk.
1838 */
1839sctp_disposition_t sctp_sf_do_5_2_4_dupcook(const struct sctp_endpoint *ep,
1840 const struct sctp_association *asoc,
1841 const sctp_subtype_t type,
1842 void *arg,
1843 sctp_cmd_seq_t *commands)
1844{
1845 sctp_disposition_t retval;
1846 struct sctp_chunk *chunk = arg;
1847 struct sctp_association *new_asoc;
1848 int error = 0;
1849 char action;
1850 struct sctp_chunk *err_chk_p;
1851
1852 /* Make sure that the chunk has a valid length from the protocol
1853 * perspective. In this case check to make sure we have at least
1854 * enough for the chunk header. Cookie length verification is
1855 * done later.
1856 */
1857 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
1858 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1859 commands);
1860
1861 /* "Decode" the chunk. We have no optional parameters so we
1862 * are in good shape.
1863 */
1864 chunk->subh.cookie_hdr = (struct sctp_signed_cookie *)chunk->skb->data;
Sridhar Samudrala62b08082006-05-05 17:04:43 -07001865 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
1866 sizeof(sctp_chunkhdr_t)))
1867 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001868
1869 /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
1870 * of a duplicate COOKIE ECHO match the Verification Tags of the
1871 * current association, consider the State Cookie valid even if
1872 * the lifespan is exceeded.
1873 */
1874 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
1875 &err_chk_p);
1876
1877 /* FIXME:
1878 * If the re-build failed, what is the proper error path
1879 * from here?
1880 *
1881 * [We should abort the association. --piggy]
1882 */
1883 if (!new_asoc) {
1884 /* FIXME: Several errors are possible. A bad cookie should
1885 * be silently discarded, but think about logging it too.
1886 */
1887 switch (error) {
1888 case -SCTP_IERROR_NOMEM:
1889 goto nomem;
1890
1891 case -SCTP_IERROR_STALE_COOKIE:
1892 sctp_send_stale_cookie_err(ep, asoc, chunk, commands,
1893 err_chk_p);
1894 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1895 case -SCTP_IERROR_BAD_SIG:
1896 default:
1897 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1898 };
1899 }
1900
1901 /* Compare the tie_tag in cookie with the verification tag of
1902 * current association.
1903 */
1904 action = sctp_tietags_compare(new_asoc, asoc);
1905
1906 switch (action) {
1907 case 'A': /* Association restart. */
1908 retval = sctp_sf_do_dupcook_a(ep, asoc, chunk, commands,
1909 new_asoc);
1910 break;
1911
1912 case 'B': /* Collision case B. */
1913 retval = sctp_sf_do_dupcook_b(ep, asoc, chunk, commands,
1914 new_asoc);
1915 break;
1916
1917 case 'C': /* Collision case C. */
1918 retval = sctp_sf_do_dupcook_c(ep, asoc, chunk, commands,
1919 new_asoc);
1920 break;
1921
1922 case 'D': /* Collision case D. */
1923 retval = sctp_sf_do_dupcook_d(ep, asoc, chunk, commands,
1924 new_asoc);
1925 break;
1926
1927 default: /* Discard packet for all others. */
1928 retval = sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1929 break;
1930 };
1931
1932 /* Delete the tempory new association. */
1933 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
1934 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
1935
1936 return retval;
1937
1938nomem:
1939 return SCTP_DISPOSITION_NOMEM;
1940}
1941
1942/*
1943 * Process an ABORT. (SHUTDOWN-PENDING state)
1944 *
1945 * See sctp_sf_do_9_1_abort().
1946 */
1947sctp_disposition_t sctp_sf_shutdown_pending_abort(
1948 const struct sctp_endpoint *ep,
1949 const struct sctp_association *asoc,
1950 const sctp_subtype_t type,
1951 void *arg,
1952 sctp_cmd_seq_t *commands)
1953{
1954 struct sctp_chunk *chunk = arg;
1955
1956 if (!sctp_vtag_verify_either(chunk, asoc))
1957 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1958
1959 /* Make sure that the ABORT chunk has a valid length.
1960 * Since this is an ABORT chunk, we have to discard it
1961 * because of the following text:
1962 * RFC 2960, Section 3.3.7
1963 * If an endpoint receives an ABORT with a format error or for an
1964 * association that doesn't exist, it MUST silently discard it.
1965 * Becasue the length is "invalid", we can't really discard just
1966 * as we do not know its true length. So, to be safe, discard the
1967 * packet.
1968 */
1969 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
1970 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1971
1972 /* Stop the T5-shutdown guard timer. */
1973 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1974 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
1975
1976 return sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
1977}
1978
1979/*
1980 * Process an ABORT. (SHUTDOWN-SENT state)
1981 *
1982 * See sctp_sf_do_9_1_abort().
1983 */
1984sctp_disposition_t sctp_sf_shutdown_sent_abort(const struct sctp_endpoint *ep,
1985 const struct sctp_association *asoc,
1986 const sctp_subtype_t type,
1987 void *arg,
1988 sctp_cmd_seq_t *commands)
1989{
1990 struct sctp_chunk *chunk = arg;
1991
1992 if (!sctp_vtag_verify_either(chunk, asoc))
1993 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1994
1995 /* Make sure that the ABORT chunk has a valid length.
1996 * Since this is an ABORT chunk, we have to discard it
1997 * because of the following text:
1998 * RFC 2960, Section 3.3.7
1999 * If an endpoint receives an ABORT with a format error or for an
2000 * association that doesn't exist, it MUST silently discard it.
2001 * Becasue the length is "invalid", we can't really discard just
2002 * as we do not know its true length. So, to be safe, discard the
2003 * packet.
2004 */
2005 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2006 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2007
2008 /* Stop the T2-shutdown timer. */
2009 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2010 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2011
2012 /* Stop the T5-shutdown guard timer. */
2013 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2014 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
2015
2016 return sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
2017}
2018
2019/*
2020 * Process an ABORT. (SHUTDOWN-ACK-SENT state)
2021 *
2022 * See sctp_sf_do_9_1_abort().
2023 */
2024sctp_disposition_t sctp_sf_shutdown_ack_sent_abort(
2025 const struct sctp_endpoint *ep,
2026 const struct sctp_association *asoc,
2027 const sctp_subtype_t type,
2028 void *arg,
2029 sctp_cmd_seq_t *commands)
2030{
2031 /* The same T2 timer, so we should be able to use
2032 * common function with the SHUTDOWN-SENT state.
2033 */
2034 return sctp_sf_shutdown_sent_abort(ep, asoc, type, arg, commands);
2035}
2036
2037/*
2038 * Handle an Error received in COOKIE_ECHOED state.
2039 *
2040 * Only handle the error type of stale COOKIE Error, the other errors will
2041 * be ignored.
2042 *
2043 * Inputs
2044 * (endpoint, asoc, chunk)
2045 *
2046 * Outputs
2047 * (asoc, reply_msg, msg_up, timers, counters)
2048 *
2049 * The return value is the disposition of the chunk.
2050 */
2051sctp_disposition_t sctp_sf_cookie_echoed_err(const struct sctp_endpoint *ep,
2052 const struct sctp_association *asoc,
2053 const sctp_subtype_t type,
2054 void *arg,
2055 sctp_cmd_seq_t *commands)
2056{
2057 struct sctp_chunk *chunk = arg;
2058 sctp_errhdr_t *err;
2059
2060 if (!sctp_vtag_verify(chunk, asoc))
2061 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2062
2063 /* Make sure that the ERROR chunk has a valid length.
2064 * The parameter walking depends on this as well.
2065 */
2066 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
2067 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2068 commands);
2069
2070 /* Process the error here */
2071 /* FUTURE FIXME: When PR-SCTP related and other optional
2072 * parms are emitted, this will have to change to handle multiple
2073 * errors.
2074 */
2075 sctp_walk_errors(err, chunk->chunk_hdr) {
2076 if (SCTP_ERROR_STALE_COOKIE == err->cause)
2077 return sctp_sf_do_5_2_6_stale(ep, asoc, type,
2078 arg, commands);
2079 }
2080
2081 /* It is possible to have malformed error causes, and that
2082 * will cause us to end the walk early. However, since
2083 * we are discarding the packet, there should be no adverse
2084 * affects.
2085 */
2086 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2087}
2088
2089/*
2090 * Handle a Stale COOKIE Error
2091 *
2092 * Section: 5.2.6 Handle Stale COOKIE Error
2093 * If the association is in the COOKIE-ECHOED state, the endpoint may elect
2094 * one of the following three alternatives.
2095 * ...
2096 * 3) Send a new INIT chunk to the endpoint, adding a Cookie
2097 * Preservative parameter requesting an extension to the lifetime of
2098 * the State Cookie. When calculating the time extension, an
2099 * implementation SHOULD use the RTT information measured based on the
2100 * previous COOKIE ECHO / ERROR exchange, and should add no more
2101 * than 1 second beyond the measured RTT, due to long State Cookie
2102 * lifetimes making the endpoint more subject to a replay attack.
2103 *
2104 * Verification Tag: Not explicit, but safe to ignore.
2105 *
2106 * Inputs
2107 * (endpoint, asoc, chunk)
2108 *
2109 * Outputs
2110 * (asoc, reply_msg, msg_up, timers, counters)
2111 *
2112 * The return value is the disposition of the chunk.
2113 */
2114static sctp_disposition_t sctp_sf_do_5_2_6_stale(const struct sctp_endpoint *ep,
2115 const struct sctp_association *asoc,
2116 const sctp_subtype_t type,
2117 void *arg,
2118 sctp_cmd_seq_t *commands)
2119{
2120 struct sctp_chunk *chunk = arg;
2121 time_t stale;
2122 sctp_cookie_preserve_param_t bht;
2123 sctp_errhdr_t *err;
2124 struct sctp_chunk *reply;
2125 struct sctp_bind_addr *bp;
Frank Filz3f7a87d2005-06-20 13:14:57 -07002126 int attempts = asoc->init_err_counter + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002127
Vlad Yasevich81845c22006-01-30 15:59:54 -08002128 if (attempts > asoc->max_init_attempts) {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002129 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
2130 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002131 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
2132 SCTP_U32(SCTP_ERROR_STALE_COOKIE));
2133 return SCTP_DISPOSITION_DELETE_TCB;
2134 }
2135
2136 err = (sctp_errhdr_t *)(chunk->skb->data);
2137
2138 /* When calculating the time extension, an implementation
2139 * SHOULD use the RTT information measured based on the
2140 * previous COOKIE ECHO / ERROR exchange, and should add no
2141 * more than 1 second beyond the measured RTT, due to long
2142 * State Cookie lifetimes making the endpoint more subject to
2143 * a replay attack.
2144 * Measure of Staleness's unit is usec. (1/1000000 sec)
2145 * Suggested Cookie Life-span Increment's unit is msec.
2146 * (1/1000 sec)
2147 * In general, if you use the suggested cookie life, the value
2148 * found in the field of measure of staleness should be doubled
2149 * to give ample time to retransmit the new cookie and thus
2150 * yield a higher probability of success on the reattempt.
2151 */
2152 stale = ntohl(*(suseconds_t *)((u8 *)err + sizeof(sctp_errhdr_t)));
2153 stale = (stale * 2) / 1000;
2154
2155 bht.param_hdr.type = SCTP_PARAM_COOKIE_PRESERVATIVE;
2156 bht.param_hdr.length = htons(sizeof(bht));
2157 bht.lifespan_increment = htonl(stale);
2158
2159 /* Build that new INIT chunk. */
2160 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
2161 reply = sctp_make_init(asoc, bp, GFP_ATOMIC, sizeof(bht));
2162 if (!reply)
2163 goto nomem;
2164
2165 sctp_addto_chunk(reply, sizeof(bht), &bht);
2166
2167 /* Clear peer's init_tag cached in assoc as we are sending a new INIT */
2168 sctp_add_cmd_sf(commands, SCTP_CMD_CLEAR_INIT_TAG, SCTP_NULL());
2169
2170 /* Stop pending T3-rtx and heartbeat timers */
2171 sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
2172 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
2173
2174 /* Delete non-primary peer ip addresses since we are transitioning
2175 * back to the COOKIE-WAIT state
2176 */
2177 sctp_add_cmd_sf(commands, SCTP_CMD_DEL_NON_PRIMARY, SCTP_NULL());
2178
2179 /* If we've sent any data bundled with COOKIE-ECHO we will need to
2180 * resend
2181 */
2182 sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN,
2183 SCTP_TRANSPORT(asoc->peer.primary_path));
2184
2185 /* Cast away the const modifier, as we want to just
2186 * rerun it through as a sideffect.
2187 */
Frank Filz3f7a87d2005-06-20 13:14:57 -07002188 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_INC, SCTP_NULL());
Linus Torvalds1da177e2005-04-16 15:20:36 -07002189
2190 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2191 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
2192 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2193 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
2194 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
2195 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
2196
2197 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2198
2199 return SCTP_DISPOSITION_CONSUME;
2200
2201nomem:
2202 return SCTP_DISPOSITION_NOMEM;
2203}
2204
2205/*
2206 * Process an ABORT.
2207 *
2208 * Section: 9.1
2209 * After checking the Verification Tag, the receiving endpoint shall
2210 * remove the association from its record, and shall report the
2211 * termination to its upper layer.
2212 *
2213 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
2214 * B) Rules for packet carrying ABORT:
2215 *
2216 * - The endpoint shall always fill in the Verification Tag field of the
2217 * outbound packet with the destination endpoint's tag value if it
2218 * is known.
2219 *
2220 * - If the ABORT is sent in response to an OOTB packet, the endpoint
2221 * MUST follow the procedure described in Section 8.4.
2222 *
2223 * - The receiver MUST accept the packet if the Verification Tag
2224 * matches either its own tag, OR the tag of its peer. Otherwise, the
2225 * receiver MUST silently discard the packet and take no further
2226 * action.
2227 *
2228 * Inputs
2229 * (endpoint, asoc, chunk)
2230 *
2231 * Outputs
2232 * (asoc, reply_msg, msg_up, timers, counters)
2233 *
2234 * The return value is the disposition of the chunk.
2235 */
2236sctp_disposition_t sctp_sf_do_9_1_abort(const struct sctp_endpoint *ep,
2237 const struct sctp_association *asoc,
2238 const sctp_subtype_t type,
2239 void *arg,
2240 sctp_cmd_seq_t *commands)
2241{
2242 struct sctp_chunk *chunk = arg;
2243 unsigned len;
2244 __u16 error = SCTP_ERROR_NO_ERROR;
2245
2246 if (!sctp_vtag_verify_either(chunk, asoc))
2247 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2248
2249 /* Make sure that the ABORT chunk has a valid length.
2250 * Since this is an ABORT chunk, we have to discard it
2251 * because of the following text:
2252 * RFC 2960, Section 3.3.7
2253 * If an endpoint receives an ABORT with a format error or for an
2254 * association that doesn't exist, it MUST silently discard it.
2255 * Becasue the length is "invalid", we can't really discard just
2256 * as we do not know its true length. So, to be safe, discard the
2257 * packet.
2258 */
2259 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2260 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2261
2262 /* See if we have an error cause code in the chunk. */
2263 len = ntohs(chunk->chunk_hdr->length);
2264 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
2265 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2266
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002267 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNRESET));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002268 /* ASSOC_FAILED will DELETE_TCB. */
2269 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, SCTP_U32(error));
2270 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
2271 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
2272
2273 return SCTP_DISPOSITION_ABORT;
2274}
2275
2276/*
2277 * Process an ABORT. (COOKIE-WAIT state)
2278 *
2279 * See sctp_sf_do_9_1_abort() above.
2280 */
2281sctp_disposition_t sctp_sf_cookie_wait_abort(const struct sctp_endpoint *ep,
2282 const struct sctp_association *asoc,
2283 const sctp_subtype_t type,
2284 void *arg,
2285 sctp_cmd_seq_t *commands)
2286{
2287 struct sctp_chunk *chunk = arg;
2288 unsigned len;
2289 __u16 error = SCTP_ERROR_NO_ERROR;
2290
2291 if (!sctp_vtag_verify_either(chunk, asoc))
2292 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2293
2294 /* Make sure that the ABORT chunk has a valid length.
2295 * Since this is an ABORT chunk, we have to discard it
2296 * because of the following text:
2297 * RFC 2960, Section 3.3.7
2298 * If an endpoint receives an ABORT with a format error or for an
2299 * association that doesn't exist, it MUST silently discard it.
2300 * Becasue the length is "invalid", we can't really discard just
2301 * as we do not know its true length. So, to be safe, discard the
2302 * packet.
2303 */
2304 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2305 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2306
2307 /* See if we have an error cause code in the chunk. */
2308 len = ntohs(chunk->chunk_hdr->length);
2309 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
2310 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2311
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002312 return sctp_stop_t1_and_abort(commands, error, ECONNREFUSED, asoc,
2313 chunk->transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002314}
2315
2316/*
2317 * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state)
2318 */
2319sctp_disposition_t sctp_sf_cookie_wait_icmp_abort(const struct sctp_endpoint *ep,
2320 const struct sctp_association *asoc,
2321 const sctp_subtype_t type,
2322 void *arg,
2323 sctp_cmd_seq_t *commands)
2324{
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002325 return sctp_stop_t1_and_abort(commands, SCTP_ERROR_NO_ERROR,
2326 ENOPROTOOPT, asoc,
Frank Filz3f7a87d2005-06-20 13:14:57 -07002327 (struct sctp_transport *)arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002328}
2329
2330/*
2331 * Process an ABORT. (COOKIE-ECHOED state)
2332 */
2333sctp_disposition_t sctp_sf_cookie_echoed_abort(const struct sctp_endpoint *ep,
2334 const struct sctp_association *asoc,
2335 const sctp_subtype_t type,
2336 void *arg,
2337 sctp_cmd_seq_t *commands)
2338{
2339 /* There is a single T1 timer, so we should be able to use
2340 * common function with the COOKIE-WAIT state.
2341 */
2342 return sctp_sf_cookie_wait_abort(ep, asoc, type, arg, commands);
2343}
2344
2345/*
2346 * Stop T1 timer and abort association with "INIT failed".
2347 *
2348 * This is common code called by several sctp_sf_*_abort() functions above.
2349 */
Adrian Bunk52c1da32005-06-23 22:05:33 -07002350static sctp_disposition_t sctp_stop_t1_and_abort(sctp_cmd_seq_t *commands,
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002351 __u16 error, int sk_err,
Frank Filz3f7a87d2005-06-20 13:14:57 -07002352 const struct sctp_association *asoc,
2353 struct sctp_transport *transport)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002354{
Frank Filz3f7a87d2005-06-20 13:14:57 -07002355 SCTP_DEBUG_PRINTK("ABORT received (INIT).\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07002356 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2357 SCTP_STATE(SCTP_STATE_CLOSED));
2358 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
2359 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2360 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002361 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(sk_err));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002362 /* CMD_INIT_FAILED will DELETE_TCB. */
2363 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
2364 SCTP_U32(error));
Frank Filz3f7a87d2005-06-20 13:14:57 -07002365 return SCTP_DISPOSITION_ABORT;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002366}
2367
2368/*
2369 * sctp_sf_do_9_2_shut
2370 *
2371 * Section: 9.2
2372 * Upon the reception of the SHUTDOWN, the peer endpoint shall
2373 * - enter the SHUTDOWN-RECEIVED state,
2374 *
2375 * - stop accepting new data from its SCTP user
2376 *
2377 * - verify, by checking the Cumulative TSN Ack field of the chunk,
2378 * that all its outstanding DATA chunks have been received by the
2379 * SHUTDOWN sender.
2380 *
2381 * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT
2382 * send a SHUTDOWN in response to a ULP request. And should discard
2383 * subsequent SHUTDOWN chunks.
2384 *
2385 * If there are still outstanding DATA chunks left, the SHUTDOWN
2386 * receiver shall continue to follow normal data transmission
2387 * procedures defined in Section 6 until all outstanding DATA chunks
2388 * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept
2389 * new data from its SCTP user.
2390 *
2391 * Verification Tag: 8.5 Verification Tag [Normal verification]
2392 *
2393 * Inputs
2394 * (endpoint, asoc, chunk)
2395 *
2396 * Outputs
2397 * (asoc, reply_msg, msg_up, timers, counters)
2398 *
2399 * The return value is the disposition of the chunk.
2400 */
2401sctp_disposition_t sctp_sf_do_9_2_shutdown(const struct sctp_endpoint *ep,
2402 const struct sctp_association *asoc,
2403 const sctp_subtype_t type,
2404 void *arg,
2405 sctp_cmd_seq_t *commands)
2406{
2407 struct sctp_chunk *chunk = arg;
2408 sctp_shutdownhdr_t *sdh;
2409 sctp_disposition_t disposition;
2410 struct sctp_ulpevent *ev;
2411
2412 if (!sctp_vtag_verify(chunk, asoc))
2413 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2414
2415 /* Make sure that the SHUTDOWN chunk has a valid length. */
2416 if (!sctp_chunk_length_valid(chunk,
2417 sizeof(struct sctp_shutdown_chunk_t)))
2418 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2419 commands);
2420
2421 /* Convert the elaborate header. */
2422 sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
2423 skb_pull(chunk->skb, sizeof(sctp_shutdownhdr_t));
2424 chunk->subh.shutdown_hdr = sdh;
2425
Sridhar Samudralaeb0e0072005-09-22 23:48:38 -07002426 /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT
2427 * When a peer sends a SHUTDOWN, SCTP delivers this notification to
2428 * inform the application that it should cease sending data.
2429 */
2430 ev = sctp_ulpevent_make_shutdown_event(asoc, 0, GFP_ATOMIC);
2431 if (!ev) {
2432 disposition = SCTP_DISPOSITION_NOMEM;
2433 goto out;
2434 }
2435 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
2436
Linus Torvalds1da177e2005-04-16 15:20:36 -07002437 /* Upon the reception of the SHUTDOWN, the peer endpoint shall
2438 * - enter the SHUTDOWN-RECEIVED state,
2439 * - stop accepting new data from its SCTP user
2440 *
2441 * [This is implicit in the new state.]
2442 */
2443 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2444 SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED));
2445 disposition = SCTP_DISPOSITION_CONSUME;
2446
2447 if (sctp_outq_is_empty(&asoc->outqueue)) {
2448 disposition = sctp_sf_do_9_2_shutdown_ack(ep, asoc, type,
2449 arg, commands);
2450 }
2451
2452 if (SCTP_DISPOSITION_NOMEM == disposition)
2453 goto out;
2454
2455 /* - verify, by checking the Cumulative TSN Ack field of the
2456 * chunk, that all its outstanding DATA chunks have been
2457 * received by the SHUTDOWN sender.
2458 */
2459 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
2460 SCTP_U32(chunk->subh.shutdown_hdr->cum_tsn_ack));
2461
Linus Torvalds1da177e2005-04-16 15:20:36 -07002462out:
2463 return disposition;
2464}
2465
2466/* RFC 2960 9.2
2467 * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk
2468 * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination
2469 * transport addresses (either in the IP addresses or in the INIT chunk)
2470 * that belong to this association, it should discard the INIT chunk and
2471 * retransmit the SHUTDOWN ACK chunk.
2472 */
2473sctp_disposition_t sctp_sf_do_9_2_reshutack(const struct sctp_endpoint *ep,
2474 const struct sctp_association *asoc,
2475 const sctp_subtype_t type,
2476 void *arg,
2477 sctp_cmd_seq_t *commands)
2478{
2479 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
2480 struct sctp_chunk *reply;
2481
2482 /* Since we are not going to really process this INIT, there
2483 * is no point in verifying chunk boundries. Just generate
2484 * the SHUTDOWN ACK.
2485 */
2486 reply = sctp_make_shutdown_ack(asoc, chunk);
2487 if (NULL == reply)
2488 goto nomem;
2489
2490 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
2491 * the T2-SHUTDOWN timer.
2492 */
2493 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
2494
2495 /* and restart the T2-shutdown timer. */
2496 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2497 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2498
2499 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2500
2501 return SCTP_DISPOSITION_CONSUME;
2502nomem:
2503 return SCTP_DISPOSITION_NOMEM;
2504}
2505
2506/*
2507 * sctp_sf_do_ecn_cwr
2508 *
2509 * Section: Appendix A: Explicit Congestion Notification
2510 *
2511 * CWR:
2512 *
2513 * RFC 2481 details a specific bit for a sender to send in the header of
2514 * its next outbound TCP segment to indicate to its peer that it has
2515 * reduced its congestion window. This is termed the CWR bit. For
2516 * SCTP the same indication is made by including the CWR chunk.
2517 * This chunk contains one data element, i.e. the TSN number that
2518 * was sent in the ECNE chunk. This element represents the lowest
2519 * TSN number in the datagram that was originally marked with the
2520 * CE bit.
2521 *
2522 * Verification Tag: 8.5 Verification Tag [Normal verification]
2523 * Inputs
2524 * (endpoint, asoc, chunk)
2525 *
2526 * Outputs
2527 * (asoc, reply_msg, msg_up, timers, counters)
2528 *
2529 * The return value is the disposition of the chunk.
2530 */
2531sctp_disposition_t sctp_sf_do_ecn_cwr(const struct sctp_endpoint *ep,
2532 const struct sctp_association *asoc,
2533 const sctp_subtype_t type,
2534 void *arg,
2535 sctp_cmd_seq_t *commands)
2536{
2537 sctp_cwrhdr_t *cwr;
2538 struct sctp_chunk *chunk = arg;
2539
2540 if (!sctp_vtag_verify(chunk, asoc))
2541 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2542
2543 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2544 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2545 commands);
2546
2547 cwr = (sctp_cwrhdr_t *) chunk->skb->data;
2548 skb_pull(chunk->skb, sizeof(sctp_cwrhdr_t));
2549
2550 cwr->lowest_tsn = ntohl(cwr->lowest_tsn);
2551
2552 /* Does this CWR ack the last sent congestion notification? */
2553 if (TSN_lte(asoc->last_ecne_tsn, cwr->lowest_tsn)) {
2554 /* Stop sending ECNE. */
2555 sctp_add_cmd_sf(commands,
2556 SCTP_CMD_ECN_CWR,
2557 SCTP_U32(cwr->lowest_tsn));
2558 }
2559 return SCTP_DISPOSITION_CONSUME;
2560}
2561
2562/*
2563 * sctp_sf_do_ecne
2564 *
2565 * Section: Appendix A: Explicit Congestion Notification
2566 *
2567 * ECN-Echo
2568 *
2569 * RFC 2481 details a specific bit for a receiver to send back in its
2570 * TCP acknowledgements to notify the sender of the Congestion
2571 * Experienced (CE) bit having arrived from the network. For SCTP this
2572 * same indication is made by including the ECNE chunk. This chunk
2573 * contains one data element, i.e. the lowest TSN associated with the IP
2574 * datagram marked with the CE bit.....
2575 *
2576 * Verification Tag: 8.5 Verification Tag [Normal verification]
2577 * Inputs
2578 * (endpoint, asoc, chunk)
2579 *
2580 * Outputs
2581 * (asoc, reply_msg, msg_up, timers, counters)
2582 *
2583 * The return value is the disposition of the chunk.
2584 */
2585sctp_disposition_t sctp_sf_do_ecne(const struct sctp_endpoint *ep,
2586 const struct sctp_association *asoc,
2587 const sctp_subtype_t type,
2588 void *arg,
2589 sctp_cmd_seq_t *commands)
2590{
2591 sctp_ecnehdr_t *ecne;
2592 struct sctp_chunk *chunk = arg;
2593
2594 if (!sctp_vtag_verify(chunk, asoc))
2595 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2596
2597 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2598 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2599 commands);
2600
2601 ecne = (sctp_ecnehdr_t *) chunk->skb->data;
2602 skb_pull(chunk->skb, sizeof(sctp_ecnehdr_t));
2603
2604 /* If this is a newer ECNE than the last CWR packet we sent out */
2605 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_ECNE,
2606 SCTP_U32(ntohl(ecne->lowest_tsn)));
2607
2608 return SCTP_DISPOSITION_CONSUME;
2609}
2610
2611/*
2612 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
2613 *
2614 * The SCTP endpoint MUST always acknowledge the reception of each valid
2615 * DATA chunk.
2616 *
2617 * The guidelines on delayed acknowledgement algorithm specified in
2618 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
2619 * acknowledgement SHOULD be generated for at least every second packet
2620 * (not every second DATA chunk) received, and SHOULD be generated within
2621 * 200 ms of the arrival of any unacknowledged DATA chunk. In some
2622 * situations it may be beneficial for an SCTP transmitter to be more
2623 * conservative than the algorithms detailed in this document allow.
2624 * However, an SCTP transmitter MUST NOT be more aggressive than the
2625 * following algorithms allow.
2626 *
2627 * A SCTP receiver MUST NOT generate more than one SACK for every
2628 * incoming packet, other than to update the offered window as the
2629 * receiving application consumes new data.
2630 *
2631 * Verification Tag: 8.5 Verification Tag [Normal verification]
2632 *
2633 * Inputs
2634 * (endpoint, asoc, chunk)
2635 *
2636 * Outputs
2637 * (asoc, reply_msg, msg_up, timers, counters)
2638 *
2639 * The return value is the disposition of the chunk.
2640 */
2641sctp_disposition_t sctp_sf_eat_data_6_2(const struct sctp_endpoint *ep,
2642 const struct sctp_association *asoc,
2643 const sctp_subtype_t type,
2644 void *arg,
2645 sctp_cmd_seq_t *commands)
2646{
2647 struct sctp_chunk *chunk = arg;
2648 int error;
2649
2650 if (!sctp_vtag_verify(chunk, asoc)) {
2651 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
2652 SCTP_NULL());
2653 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2654 }
2655
2656 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
2657 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2658 commands);
2659
2660 error = sctp_eat_data(asoc, chunk, commands );
2661 switch (error) {
2662 case SCTP_IERROR_NO_ERROR:
2663 break;
2664 case SCTP_IERROR_HIGH_TSN:
2665 case SCTP_IERROR_BAD_STREAM:
2666 goto discard_noforce;
2667 case SCTP_IERROR_DUP_TSN:
2668 case SCTP_IERROR_IGNORE_TSN:
2669 goto discard_force;
2670 case SCTP_IERROR_NO_DATA:
2671 goto consume;
2672 default:
2673 BUG();
2674 }
2675
2676 if (asoc->autoclose) {
2677 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2678 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
2679 }
2680
2681 /* If this is the last chunk in a packet, we need to count it
2682 * toward sack generation. Note that we need to SACK every
2683 * OTHER packet containing data chunks, EVEN IF WE DISCARD
2684 * THEM. We elect to NOT generate SACK's if the chunk fails
2685 * the verification tag test.
2686 *
2687 * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2688 *
2689 * The SCTP endpoint MUST always acknowledge the reception of
2690 * each valid DATA chunk.
2691 *
2692 * The guidelines on delayed acknowledgement algorithm
2693 * specified in Section 4.2 of [RFC2581] SHOULD be followed.
2694 * Specifically, an acknowledgement SHOULD be generated for at
2695 * least every second packet (not every second DATA chunk)
2696 * received, and SHOULD be generated within 200 ms of the
2697 * arrival of any unacknowledged DATA chunk. In some
2698 * situations it may be beneficial for an SCTP transmitter to
2699 * be more conservative than the algorithms detailed in this
2700 * document allow. However, an SCTP transmitter MUST NOT be
2701 * more aggressive than the following algorithms allow.
2702 */
Frank Filz52ccb8e2005-12-22 11:36:46 -08002703 if (chunk->end_of_packet)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002704 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
2705
Linus Torvalds1da177e2005-04-16 15:20:36 -07002706 return SCTP_DISPOSITION_CONSUME;
2707
2708discard_force:
2709 /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2710 *
2711 * When a packet arrives with duplicate DATA chunk(s) and with
2712 * no new DATA chunk(s), the endpoint MUST immediately send a
2713 * SACK with no delay. If a packet arrives with duplicate
2714 * DATA chunk(s) bundled with new DATA chunks, the endpoint
2715 * MAY immediately send a SACK. Normally receipt of duplicate
2716 * DATA chunks will occur when the original SACK chunk was lost
2717 * and the peer's RTO has expired. The duplicate TSN number(s)
2718 * SHOULD be reported in the SACK as duplicate.
2719 */
2720 /* In our case, we split the MAY SACK advice up whether or not
2721 * the last chunk is a duplicate.'
2722 */
2723 if (chunk->end_of_packet)
2724 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
2725 return SCTP_DISPOSITION_DISCARD;
2726
2727discard_noforce:
Frank Filz52ccb8e2005-12-22 11:36:46 -08002728 if (chunk->end_of_packet)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002729 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
2730
Linus Torvalds1da177e2005-04-16 15:20:36 -07002731 return SCTP_DISPOSITION_DISCARD;
2732consume:
2733 return SCTP_DISPOSITION_CONSUME;
2734
2735}
2736
2737/*
2738 * sctp_sf_eat_data_fast_4_4
2739 *
2740 * Section: 4 (4)
2741 * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received
2742 * DATA chunks without delay.
2743 *
2744 * Verification Tag: 8.5 Verification Tag [Normal verification]
2745 * Inputs
2746 * (endpoint, asoc, chunk)
2747 *
2748 * Outputs
2749 * (asoc, reply_msg, msg_up, timers, counters)
2750 *
2751 * The return value is the disposition of the chunk.
2752 */
2753sctp_disposition_t sctp_sf_eat_data_fast_4_4(const struct sctp_endpoint *ep,
2754 const struct sctp_association *asoc,
2755 const sctp_subtype_t type,
2756 void *arg,
2757 sctp_cmd_seq_t *commands)
2758{
2759 struct sctp_chunk *chunk = arg;
2760 int error;
2761
2762 if (!sctp_vtag_verify(chunk, asoc)) {
2763 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
2764 SCTP_NULL());
2765 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2766 }
2767
2768 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
2769 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2770 commands);
2771
2772 error = sctp_eat_data(asoc, chunk, commands );
2773 switch (error) {
2774 case SCTP_IERROR_NO_ERROR:
2775 case SCTP_IERROR_HIGH_TSN:
2776 case SCTP_IERROR_DUP_TSN:
2777 case SCTP_IERROR_IGNORE_TSN:
2778 case SCTP_IERROR_BAD_STREAM:
2779 break;
2780 case SCTP_IERROR_NO_DATA:
2781 goto consume;
2782 default:
2783 BUG();
2784 }
2785
2786 /* Go a head and force a SACK, since we are shutting down. */
2787
2788 /* Implementor's Guide.
2789 *
2790 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
2791 * respond to each received packet containing one or more DATA chunk(s)
2792 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
2793 */
2794 if (chunk->end_of_packet) {
2795 /* We must delay the chunk creation since the cumulative
2796 * TSN has not been updated yet.
2797 */
2798 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
2799 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
2800 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2801 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2802 }
2803
2804consume:
2805 return SCTP_DISPOSITION_CONSUME;
2806}
2807
2808/*
2809 * Section: 6.2 Processing a Received SACK
2810 * D) Any time a SACK arrives, the endpoint performs the following:
2811 *
2812 * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point,
2813 * then drop the SACK. Since Cumulative TSN Ack is monotonically
2814 * increasing, a SACK whose Cumulative TSN Ack is less than the
2815 * Cumulative TSN Ack Point indicates an out-of-order SACK.
2816 *
2817 * ii) Set rwnd equal to the newly received a_rwnd minus the number
2818 * of bytes still outstanding after processing the Cumulative TSN Ack
2819 * and the Gap Ack Blocks.
2820 *
2821 * iii) If the SACK is missing a TSN that was previously
2822 * acknowledged via a Gap Ack Block (e.g., the data receiver
2823 * reneged on the data), then mark the corresponding DATA chunk
2824 * as available for retransmit: Mark it as missing for fast
2825 * retransmit as described in Section 7.2.4 and if no retransmit
2826 * timer is running for the destination address to which the DATA
2827 * chunk was originally transmitted, then T3-rtx is started for
2828 * that destination address.
2829 *
2830 * Verification Tag: 8.5 Verification Tag [Normal verification]
2831 *
2832 * Inputs
2833 * (endpoint, asoc, chunk)
2834 *
2835 * Outputs
2836 * (asoc, reply_msg, msg_up, timers, counters)
2837 *
2838 * The return value is the disposition of the chunk.
2839 */
2840sctp_disposition_t sctp_sf_eat_sack_6_2(const struct sctp_endpoint *ep,
2841 const struct sctp_association *asoc,
2842 const sctp_subtype_t type,
2843 void *arg,
2844 sctp_cmd_seq_t *commands)
2845{
2846 struct sctp_chunk *chunk = arg;
2847 sctp_sackhdr_t *sackh;
2848 __u32 ctsn;
2849
2850 if (!sctp_vtag_verify(chunk, asoc))
2851 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2852
2853 /* Make sure that the SACK chunk has a valid length. */
2854 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_sack_chunk_t)))
2855 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2856 commands);
2857
2858 /* Pull the SACK chunk from the data buffer */
2859 sackh = sctp_sm_pull_sack(chunk);
2860 /* Was this a bogus SACK? */
2861 if (!sackh)
2862 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2863 chunk->subh.sack_hdr = sackh;
2864 ctsn = ntohl(sackh->cum_tsn_ack);
2865
2866 /* i) If Cumulative TSN Ack is less than the Cumulative TSN
2867 * Ack Point, then drop the SACK. Since Cumulative TSN
2868 * Ack is monotonically increasing, a SACK whose
2869 * Cumulative TSN Ack is less than the Cumulative TSN Ack
2870 * Point indicates an out-of-order SACK.
2871 */
2872 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
2873 SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn);
2874 SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc->ctsn_ack_point);
2875 return SCTP_DISPOSITION_DISCARD;
2876 }
2877
2878 /* Return this SACK for further processing. */
2879 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_SACKH(sackh));
2880
2881 /* Note: We do the rest of the work on the PROCESS_SACK
2882 * sideeffect.
2883 */
2884 return SCTP_DISPOSITION_CONSUME;
2885}
2886
2887/*
2888 * Generate an ABORT in response to a packet.
2889 *
Jerome Forissier047a2422005-04-28 11:58:43 -07002890 * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41
Linus Torvalds1da177e2005-04-16 15:20:36 -07002891 *
Jerome Forissier047a2422005-04-28 11:58:43 -07002892 * 8) The receiver should respond to the sender of the OOTB packet with
2893 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
2894 * MUST fill in the Verification Tag field of the outbound packet
2895 * with the value found in the Verification Tag field of the OOTB
2896 * packet and set the T-bit in the Chunk Flags to indicate that the
2897 * Verification Tag is reflected. After sending this ABORT, the
2898 * receiver of the OOTB packet shall discard the OOTB packet and take
2899 * no further action.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002900 *
2901 * Verification Tag:
2902 *
2903 * The return value is the disposition of the chunk.
2904*/
2905sctp_disposition_t sctp_sf_tabort_8_4_8(const struct sctp_endpoint *ep,
2906 const struct sctp_association *asoc,
2907 const sctp_subtype_t type,
2908 void *arg,
2909 sctp_cmd_seq_t *commands)
2910{
2911 struct sctp_packet *packet = NULL;
2912 struct sctp_chunk *chunk = arg;
2913 struct sctp_chunk *abort;
2914
2915 packet = sctp_ootb_pkt_new(asoc, chunk);
2916
2917 if (packet) {
2918 /* Make an ABORT. The T bit will be set if the asoc
2919 * is NULL.
2920 */
2921 abort = sctp_make_abort(asoc, chunk, 0);
2922 if (!abort) {
2923 sctp_ootb_pkt_free(packet);
2924 return SCTP_DISPOSITION_NOMEM;
2925 }
2926
Jerome Forissier047a2422005-04-28 11:58:43 -07002927 /* Reflect vtag if T-Bit is set */
2928 if (sctp_test_T_bit(abort))
2929 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
2930
Linus Torvalds1da177e2005-04-16 15:20:36 -07002931 /* Set the skb to the belonging sock for accounting. */
2932 abort->skb->sk = ep->base.sk;
2933
2934 sctp_packet_append_chunk(packet, abort);
2935
2936 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
2937 SCTP_PACKET(packet));
2938
2939 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
2940
2941 return SCTP_DISPOSITION_CONSUME;
2942 }
2943
2944 return SCTP_DISPOSITION_NOMEM;
2945}
2946
2947/*
2948 * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR
2949 * event as ULP notification for each cause included in the chunk.
2950 *
2951 * API 5.3.1.3 - SCTP_REMOTE_ERROR
2952 *
2953 * The return value is the disposition of the chunk.
2954*/
2955sctp_disposition_t sctp_sf_operr_notify(const struct sctp_endpoint *ep,
2956 const struct sctp_association *asoc,
2957 const sctp_subtype_t type,
2958 void *arg,
2959 sctp_cmd_seq_t *commands)
2960{
2961 struct sctp_chunk *chunk = arg;
2962 struct sctp_ulpevent *ev;
2963
2964 if (!sctp_vtag_verify(chunk, asoc))
2965 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2966
2967 /* Make sure that the ERROR chunk has a valid length. */
2968 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
2969 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2970 commands);
2971
2972 while (chunk->chunk_end > chunk->skb->data) {
2973 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
2974 GFP_ATOMIC);
2975 if (!ev)
2976 goto nomem;
2977
2978 if (!sctp_add_cmd(commands, SCTP_CMD_EVENT_ULP,
2979 SCTP_ULPEVENT(ev))) {
2980 sctp_ulpevent_free(ev);
2981 goto nomem;
2982 }
2983
2984 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_OPERR,
2985 SCTP_CHUNK(chunk));
2986 }
2987 return SCTP_DISPOSITION_CONSUME;
2988
2989nomem:
2990 return SCTP_DISPOSITION_NOMEM;
2991}
2992
2993/*
2994 * Process an inbound SHUTDOWN ACK.
2995 *
2996 * From Section 9.2:
2997 * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
2998 * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its
2999 * peer, and remove all record of the association.
3000 *
3001 * The return value is the disposition.
3002 */
3003sctp_disposition_t sctp_sf_do_9_2_final(const struct sctp_endpoint *ep,
3004 const struct sctp_association *asoc,
3005 const sctp_subtype_t type,
3006 void *arg,
3007 sctp_cmd_seq_t *commands)
3008{
3009 struct sctp_chunk *chunk = arg;
3010 struct sctp_chunk *reply;
3011 struct sctp_ulpevent *ev;
3012
3013 if (!sctp_vtag_verify(chunk, asoc))
3014 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3015
3016 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3017 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3018 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3019 commands);
3020
3021 /* 10.2 H) SHUTDOWN COMPLETE notification
3022 *
3023 * When SCTP completes the shutdown procedures (section 9.2) this
3024 * notification is passed to the upper layer.
3025 */
3026 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
3027 0, 0, 0, GFP_ATOMIC);
3028 if (!ev)
3029 goto nomem;
3030
3031 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
3032
3033 /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3034 * stop the T2-shutdown timer,
3035 */
3036 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3037 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3038
3039 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3040 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
3041
3042 /* ...send a SHUTDOWN COMPLETE chunk to its peer, */
3043 reply = sctp_make_shutdown_complete(asoc, chunk);
3044 if (!reply)
3045 goto nomem;
3046
3047 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3048 SCTP_STATE(SCTP_STATE_CLOSED));
3049 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
3050 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3051 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
3052
3053 /* ...and remove all record of the association. */
3054 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
3055 return SCTP_DISPOSITION_DELETE_TCB;
3056
3057nomem:
3058 return SCTP_DISPOSITION_NOMEM;
3059}
3060
3061/*
Jerome Forissier047a2422005-04-28 11:58:43 -07003062 * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41.
3063 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003064 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3065 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3066 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3067 * packet must fill in the Verification Tag field of the outbound
3068 * packet with the Verification Tag received in the SHUTDOWN ACK and
Jerome Forissier047a2422005-04-28 11:58:43 -07003069 * set the T-bit in the Chunk Flags to indicate that the Verification
3070 * Tag is reflected.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003071 *
3072 * 8) The receiver should respond to the sender of the OOTB packet with
3073 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3074 * MUST fill in the Verification Tag field of the outbound packet
3075 * with the value found in the Verification Tag field of the OOTB
Jerome Forissier047a2422005-04-28 11:58:43 -07003076 * packet and set the T-bit in the Chunk Flags to indicate that the
3077 * Verification Tag is reflected. After sending this ABORT, the
3078 * receiver of the OOTB packet shall discard the OOTB packet and take
3079 * no further action.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003080 */
3081sctp_disposition_t sctp_sf_ootb(const struct sctp_endpoint *ep,
3082 const struct sctp_association *asoc,
3083 const sctp_subtype_t type,
3084 void *arg,
3085 sctp_cmd_seq_t *commands)
3086{
3087 struct sctp_chunk *chunk = arg;
3088 struct sk_buff *skb = chunk->skb;
3089 sctp_chunkhdr_t *ch;
3090 __u8 *ch_end;
3091 int ootb_shut_ack = 0;
3092
3093 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES);
3094
3095 ch = (sctp_chunkhdr_t *) chunk->chunk_hdr;
3096 do {
3097 /* Break out if chunk length is less then minimal. */
3098 if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t))
3099 break;
3100
3101 ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
Tsutomu Fujiia7d1f1b2006-01-17 11:57:09 -08003102 if (ch_end > skb->tail)
3103 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003104
3105 if (SCTP_CID_SHUTDOWN_ACK == ch->type)
3106 ootb_shut_ack = 1;
3107
3108 /* RFC 2960, Section 3.3.7
3109 * Moreover, under any circumstances, an endpoint that
3110 * receives an ABORT MUST NOT respond to that ABORT by
3111 * sending an ABORT of its own.
3112 */
3113 if (SCTP_CID_ABORT == ch->type)
3114 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3115
3116 ch = (sctp_chunkhdr_t *) ch_end;
3117 } while (ch_end < skb->tail);
3118
3119 if (ootb_shut_ack)
3120 sctp_sf_shut_8_4_5(ep, asoc, type, arg, commands);
3121 else
3122 sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
3123
3124 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3125}
3126
3127/*
3128 * Handle an "Out of the blue" SHUTDOWN ACK.
3129 *
Jerome Forissier047a2422005-04-28 11:58:43 -07003130 * Section: 8.4 5, sctpimpguide 2.41.
3131 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003132 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
Jerome Forissier047a2422005-04-28 11:58:43 -07003133 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3134 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3135 * packet must fill in the Verification Tag field of the outbound
3136 * packet with the Verification Tag received in the SHUTDOWN ACK and
3137 * set the T-bit in the Chunk Flags to indicate that the Verification
3138 * Tag is reflected.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003139 *
3140 * Inputs
3141 * (endpoint, asoc, type, arg, commands)
3142 *
3143 * Outputs
3144 * (sctp_disposition_t)
3145 *
3146 * The return value is the disposition of the chunk.
3147 */
3148static sctp_disposition_t sctp_sf_shut_8_4_5(const struct sctp_endpoint *ep,
3149 const struct sctp_association *asoc,
3150 const sctp_subtype_t type,
3151 void *arg,
3152 sctp_cmd_seq_t *commands)
3153{
3154 struct sctp_packet *packet = NULL;
3155 struct sctp_chunk *chunk = arg;
3156 struct sctp_chunk *shut;
3157
3158 packet = sctp_ootb_pkt_new(asoc, chunk);
3159
3160 if (packet) {
3161 /* Make an SHUTDOWN_COMPLETE.
3162 * The T bit will be set if the asoc is NULL.
3163 */
3164 shut = sctp_make_shutdown_complete(asoc, chunk);
3165 if (!shut) {
3166 sctp_ootb_pkt_free(packet);
3167 return SCTP_DISPOSITION_NOMEM;
3168 }
3169
Jerome Forissier047a2422005-04-28 11:58:43 -07003170 /* Reflect vtag if T-Bit is set */
3171 if (sctp_test_T_bit(shut))
3172 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3173
Linus Torvalds1da177e2005-04-16 15:20:36 -07003174 /* Set the skb to the belonging sock for accounting. */
3175 shut->skb->sk = ep->base.sk;
3176
3177 sctp_packet_append_chunk(packet, shut);
3178
3179 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3180 SCTP_PACKET(packet));
3181
3182 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
3183
3184 /* If the chunk length is invalid, we don't want to process
3185 * the reset of the packet.
3186 */
3187 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3188 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3189
3190 return SCTP_DISPOSITION_CONSUME;
3191 }
3192
3193 return SCTP_DISPOSITION_NOMEM;
3194}
3195
3196/*
3197 * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state.
3198 *
3199 * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK
3200 * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the
3201 * procedures in section 8.4 SHOULD be followed, in other words it
3202 * should be treated as an Out Of The Blue packet.
3203 * [This means that we do NOT check the Verification Tag on these
3204 * chunks. --piggy ]
3205 *
3206 */
3207sctp_disposition_t sctp_sf_do_8_5_1_E_sa(const struct sctp_endpoint *ep,
3208 const struct sctp_association *asoc,
3209 const sctp_subtype_t type,
3210 void *arg,
3211 sctp_cmd_seq_t *commands)
3212{
3213 /* Although we do have an association in this case, it corresponds
3214 * to a restarted association. So the packet is treated as an OOTB
3215 * packet and the state function that handles OOTB SHUTDOWN_ACK is
3216 * called with a NULL association.
3217 */
3218 return sctp_sf_shut_8_4_5(ep, NULL, type, arg, commands);
3219}
3220
3221/* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */
3222sctp_disposition_t sctp_sf_do_asconf(const struct sctp_endpoint *ep,
3223 const struct sctp_association *asoc,
3224 const sctp_subtype_t type, void *arg,
3225 sctp_cmd_seq_t *commands)
3226{
3227 struct sctp_chunk *chunk = arg;
3228 struct sctp_chunk *asconf_ack = NULL;
3229 sctp_addiphdr_t *hdr;
3230 __u32 serial;
3231
3232 if (!sctp_vtag_verify(chunk, asoc)) {
3233 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3234 SCTP_NULL());
3235 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3236 }
3237
3238 /* Make sure that the ASCONF ADDIP chunk has a valid length. */
3239 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_addip_chunk_t)))
3240 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3241 commands);
3242
3243 hdr = (sctp_addiphdr_t *)chunk->skb->data;
3244 serial = ntohl(hdr->serial);
3245
3246 /* ADDIP 4.2 C1) Compare the value of the serial number to the value
3247 * the endpoint stored in a new association variable
3248 * 'Peer-Serial-Number'.
3249 */
3250 if (serial == asoc->peer.addip_serial + 1) {
3251 /* ADDIP 4.2 C2) If the value found in the serial number is
3252 * equal to the ('Peer-Serial-Number' + 1), the endpoint MUST
3253 * do V1-V5.
3254 */
3255 asconf_ack = sctp_process_asconf((struct sctp_association *)
3256 asoc, chunk);
3257 if (!asconf_ack)
3258 return SCTP_DISPOSITION_NOMEM;
3259 } else if (serial == asoc->peer.addip_serial) {
3260 /* ADDIP 4.2 C3) If the value found in the serial number is
3261 * equal to the value stored in the 'Peer-Serial-Number'
3262 * IMPLEMENTATION NOTE: As an optimization a receiver may wish
3263 * to save the last ASCONF-ACK for some predetermined period of
3264 * time and instead of re-processing the ASCONF (with the same
3265 * serial number) it may just re-transmit the ASCONF-ACK.
3266 */
3267 if (asoc->addip_last_asconf_ack)
3268 asconf_ack = asoc->addip_last_asconf_ack;
3269 else
3270 return SCTP_DISPOSITION_DISCARD;
3271 } else {
3272 /* ADDIP 4.2 C4) Otherwise, the ASCONF Chunk is discarded since
3273 * it must be either a stale packet or from an attacker.
3274 */
3275 return SCTP_DISPOSITION_DISCARD;
3276 }
3277
3278 /* ADDIP 4.2 C5) In both cases C2 and C3 the ASCONF-ACK MUST be sent
3279 * back to the source address contained in the IP header of the ASCONF
3280 * being responded to.
3281 */
3282 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(asconf_ack));
3283
3284 return SCTP_DISPOSITION_CONSUME;
3285}
3286
3287/*
3288 * ADDIP Section 4.3 General rules for address manipulation
3289 * When building TLV parameters for the ASCONF Chunk that will add or
3290 * delete IP addresses the D0 to D13 rules should be applied:
3291 */
3292sctp_disposition_t sctp_sf_do_asconf_ack(const struct sctp_endpoint *ep,
3293 const struct sctp_association *asoc,
3294 const sctp_subtype_t type, void *arg,
3295 sctp_cmd_seq_t *commands)
3296{
3297 struct sctp_chunk *asconf_ack = arg;
3298 struct sctp_chunk *last_asconf = asoc->addip_last_asconf;
3299 struct sctp_chunk *abort;
3300 sctp_addiphdr_t *addip_hdr;
3301 __u32 sent_serial, rcvd_serial;
3302
3303 if (!sctp_vtag_verify(asconf_ack, asoc)) {
3304 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3305 SCTP_NULL());
3306 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3307 }
3308
3309 /* Make sure that the ADDIP chunk has a valid length. */
3310 if (!sctp_chunk_length_valid(asconf_ack, sizeof(sctp_addip_chunk_t)))
3311 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3312 commands);
3313
3314 addip_hdr = (sctp_addiphdr_t *)asconf_ack->skb->data;
3315 rcvd_serial = ntohl(addip_hdr->serial);
3316
3317 if (last_asconf) {
3318 addip_hdr = (sctp_addiphdr_t *)last_asconf->subh.addip_hdr;
3319 sent_serial = ntohl(addip_hdr->serial);
3320 } else {
3321 sent_serial = asoc->addip_serial - 1;
3322 }
3323
3324 /* D0) If an endpoint receives an ASCONF-ACK that is greater than or
3325 * equal to the next serial number to be used but no ASCONF chunk is
3326 * outstanding the endpoint MUST ABORT the association. Note that a
3327 * sequence number is greater than if it is no more than 2^^31-1
3328 * larger than the current sequence number (using serial arithmetic).
3329 */
3330 if (ADDIP_SERIAL_gte(rcvd_serial, sent_serial + 1) &&
3331 !(asoc->addip_last_asconf)) {
3332 abort = sctp_make_abort(asoc, asconf_ack,
3333 sizeof(sctp_errhdr_t));
3334 if (abort) {
3335 sctp_init_cause(abort, SCTP_ERROR_ASCONF_ACK, NULL, 0);
3336 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3337 SCTP_CHUNK(abort));
3338 }
3339 /* We are going to ABORT, so we might as well stop
3340 * processing the rest of the chunks in the packet.
3341 */
3342 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3343 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3344 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07003345 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
3346 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003347 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
3348 SCTP_U32(SCTP_ERROR_ASCONF_ACK));
3349 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
3350 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3351 return SCTP_DISPOSITION_ABORT;
3352 }
3353
3354 if ((rcvd_serial == sent_serial) && asoc->addip_last_asconf) {
3355 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3356 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3357
3358 if (!sctp_process_asconf_ack((struct sctp_association *)asoc,
3359 asconf_ack))
3360 return SCTP_DISPOSITION_CONSUME;
3361
3362 abort = sctp_make_abort(asoc, asconf_ack,
3363 sizeof(sctp_errhdr_t));
3364 if (abort) {
3365 sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, NULL, 0);
3366 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3367 SCTP_CHUNK(abort));
3368 }
3369 /* We are going to ABORT, so we might as well stop
3370 * processing the rest of the chunks in the packet.
3371 */
3372 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07003373 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
3374 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003375 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
3376 SCTP_U32(SCTP_ERROR_ASCONF_ACK));
3377 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
3378 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3379 return SCTP_DISPOSITION_ABORT;
3380 }
3381
3382 return SCTP_DISPOSITION_DISCARD;
3383}
3384
3385/*
3386 * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP
3387 *
3388 * When a FORWARD TSN chunk arrives, the data receiver MUST first update
3389 * its cumulative TSN point to the value carried in the FORWARD TSN
3390 * chunk, and then MUST further advance its cumulative TSN point locally
3391 * if possible.
3392 * After the above processing, the data receiver MUST stop reporting any
3393 * missing TSNs earlier than or equal to the new cumulative TSN point.
3394 *
3395 * Verification Tag: 8.5 Verification Tag [Normal verification]
3396 *
3397 * The return value is the disposition of the chunk.
3398 */
3399sctp_disposition_t sctp_sf_eat_fwd_tsn(const struct sctp_endpoint *ep,
3400 const struct sctp_association *asoc,
3401 const sctp_subtype_t type,
3402 void *arg,
3403 sctp_cmd_seq_t *commands)
3404{
3405 struct sctp_chunk *chunk = arg;
3406 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
3407 __u16 len;
3408 __u32 tsn;
3409
3410 if (!sctp_vtag_verify(chunk, asoc)) {
3411 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3412 SCTP_NULL());
3413 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3414 }
3415
3416 /* Make sure that the FORWARD_TSN chunk has valid length. */
3417 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
3418 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3419 commands);
3420
3421 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3422 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3423 len = ntohs(chunk->chunk_hdr->length);
3424 len -= sizeof(struct sctp_chunkhdr);
3425 skb_pull(chunk->skb, len);
3426
3427 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
3428 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __FUNCTION__, tsn);
3429
3430 /* The TSN is too high--silently discard the chunk and count on it
3431 * getting retransmitted later.
3432 */
3433 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3434 goto discard_noforce;
3435
3436 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3437 if (len > sizeof(struct sctp_fwdtsn_hdr))
3438 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
3439 SCTP_CHUNK(chunk));
3440
3441 /* Count this as receiving DATA. */
3442 if (asoc->autoclose) {
3443 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3444 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
3445 }
3446
3447 /* FIXME: For now send a SACK, but DATA processing may
3448 * send another.
3449 */
3450 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
Linus Torvalds1da177e2005-04-16 15:20:36 -07003451
3452 return SCTP_DISPOSITION_CONSUME;
3453
3454discard_noforce:
3455 return SCTP_DISPOSITION_DISCARD;
3456}
3457
3458sctp_disposition_t sctp_sf_eat_fwd_tsn_fast(
3459 const struct sctp_endpoint *ep,
3460 const struct sctp_association *asoc,
3461 const sctp_subtype_t type,
3462 void *arg,
3463 sctp_cmd_seq_t *commands)
3464{
3465 struct sctp_chunk *chunk = arg;
3466 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
3467 __u16 len;
3468 __u32 tsn;
3469
3470 if (!sctp_vtag_verify(chunk, asoc)) {
3471 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3472 SCTP_NULL());
3473 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3474 }
3475
3476 /* Make sure that the FORWARD_TSN chunk has a valid length. */
3477 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
3478 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3479 commands);
3480
3481 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3482 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3483 len = ntohs(chunk->chunk_hdr->length);
3484 len -= sizeof(struct sctp_chunkhdr);
3485 skb_pull(chunk->skb, len);
3486
3487 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
3488 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __FUNCTION__, tsn);
3489
3490 /* The TSN is too high--silently discard the chunk and count on it
3491 * getting retransmitted later.
3492 */
3493 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3494 goto gen_shutdown;
3495
3496 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3497 if (len > sizeof(struct sctp_fwdtsn_hdr))
3498 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
3499 SCTP_CHUNK(chunk));
3500
3501 /* Go a head and force a SACK, since we are shutting down. */
3502gen_shutdown:
3503 /* Implementor's Guide.
3504 *
3505 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3506 * respond to each received packet containing one or more DATA chunk(s)
3507 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3508 */
3509 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
3510 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3511 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3512 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3513
3514 return SCTP_DISPOSITION_CONSUME;
3515}
3516
3517/*
3518 * Process an unknown chunk.
3519 *
3520 * Section: 3.2. Also, 2.1 in the implementor's guide.
3521 *
3522 * Chunk Types are encoded such that the highest-order two bits specify
3523 * the action that must be taken if the processing endpoint does not
3524 * recognize the Chunk Type.
3525 *
3526 * 00 - Stop processing this SCTP packet and discard it, do not process
3527 * any further chunks within it.
3528 *
3529 * 01 - Stop processing this SCTP packet and discard it, do not process
3530 * any further chunks within it, and report the unrecognized
3531 * chunk in an 'Unrecognized Chunk Type'.
3532 *
3533 * 10 - Skip this chunk and continue processing.
3534 *
3535 * 11 - Skip this chunk and continue processing, but report in an ERROR
3536 * Chunk using the 'Unrecognized Chunk Type' cause of error.
3537 *
3538 * The return value is the disposition of the chunk.
3539 */
3540sctp_disposition_t sctp_sf_unk_chunk(const struct sctp_endpoint *ep,
3541 const struct sctp_association *asoc,
3542 const sctp_subtype_t type,
3543 void *arg,
3544 sctp_cmd_seq_t *commands)
3545{
3546 struct sctp_chunk *unk_chunk = arg;
3547 struct sctp_chunk *err_chunk;
3548 sctp_chunkhdr_t *hdr;
3549
3550 SCTP_DEBUG_PRINTK("Processing the unknown chunk id %d.\n", type.chunk);
3551
3552 if (!sctp_vtag_verify(unk_chunk, asoc))
3553 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3554
3555 /* Make sure that the chunk has a valid length.
3556 * Since we don't know the chunk type, we use a general
3557 * chunkhdr structure to make a comparison.
3558 */
3559 if (!sctp_chunk_length_valid(unk_chunk, sizeof(sctp_chunkhdr_t)))
3560 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3561 commands);
3562
3563 switch (type.chunk & SCTP_CID_ACTION_MASK) {
3564 case SCTP_CID_ACTION_DISCARD:
3565 /* Discard the packet. */
3566 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3567 break;
3568 case SCTP_CID_ACTION_DISCARD_ERR:
3569 /* Discard the packet. */
3570 sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3571
3572 /* Generate an ERROR chunk as response. */
3573 hdr = unk_chunk->chunk_hdr;
3574 err_chunk = sctp_make_op_error(asoc, unk_chunk,
3575 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
3576 WORD_ROUND(ntohs(hdr->length)));
3577 if (err_chunk) {
3578 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3579 SCTP_CHUNK(err_chunk));
3580 }
3581 return SCTP_DISPOSITION_CONSUME;
3582 break;
3583 case SCTP_CID_ACTION_SKIP:
3584 /* Skip the chunk. */
3585 return SCTP_DISPOSITION_DISCARD;
3586 break;
3587 case SCTP_CID_ACTION_SKIP_ERR:
3588 /* Generate an ERROR chunk as response. */
3589 hdr = unk_chunk->chunk_hdr;
3590 err_chunk = sctp_make_op_error(asoc, unk_chunk,
3591 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
3592 WORD_ROUND(ntohs(hdr->length)));
3593 if (err_chunk) {
3594 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3595 SCTP_CHUNK(err_chunk));
3596 }
3597 /* Skip the chunk. */
3598 return SCTP_DISPOSITION_CONSUME;
3599 break;
3600 default:
3601 break;
3602 }
3603
3604 return SCTP_DISPOSITION_DISCARD;
3605}
3606
3607/*
3608 * Discard the chunk.
3609 *
3610 * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2
3611 * [Too numerous to mention...]
3612 * Verification Tag: No verification needed.
3613 * Inputs
3614 * (endpoint, asoc, chunk)
3615 *
3616 * Outputs
3617 * (asoc, reply_msg, msg_up, timers, counters)
3618 *
3619 * The return value is the disposition of the chunk.
3620 */
3621sctp_disposition_t sctp_sf_discard_chunk(const struct sctp_endpoint *ep,
3622 const struct sctp_association *asoc,
3623 const sctp_subtype_t type,
3624 void *arg,
3625 sctp_cmd_seq_t *commands)
3626{
3627 SCTP_DEBUG_PRINTK("Chunk %d is discarded\n", type.chunk);
3628 return SCTP_DISPOSITION_DISCARD;
3629}
3630
3631/*
3632 * Discard the whole packet.
3633 *
3634 * Section: 8.4 2)
3635 *
3636 * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST
3637 * silently discard the OOTB packet and take no further action.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003638 *
3639 * Verification Tag: No verification necessary
3640 *
3641 * Inputs
3642 * (endpoint, asoc, chunk)
3643 *
3644 * Outputs
3645 * (asoc, reply_msg, msg_up, timers, counters)
3646 *
3647 * The return value is the disposition of the chunk.
3648 */
3649sctp_disposition_t sctp_sf_pdiscard(const struct sctp_endpoint *ep,
3650 const struct sctp_association *asoc,
3651 const sctp_subtype_t type,
3652 void *arg,
3653 sctp_cmd_seq_t *commands)
3654{
3655 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
3656
3657 return SCTP_DISPOSITION_CONSUME;
3658}
3659
3660
3661/*
3662 * The other end is violating protocol.
3663 *
3664 * Section: Not specified
3665 * Verification Tag: Not specified
3666 * Inputs
3667 * (endpoint, asoc, chunk)
3668 *
3669 * Outputs
3670 * (asoc, reply_msg, msg_up, timers, counters)
3671 *
3672 * We simply tag the chunk as a violation. The state machine will log
3673 * the violation and continue.
3674 */
3675sctp_disposition_t sctp_sf_violation(const struct sctp_endpoint *ep,
3676 const struct sctp_association *asoc,
3677 const sctp_subtype_t type,
3678 void *arg,
3679 sctp_cmd_seq_t *commands)
3680{
3681 return SCTP_DISPOSITION_VIOLATION;
3682}
3683
3684
3685/*
3686 * Handle a protocol violation when the chunk length is invalid.
3687 * "Invalid" length is identified as smaller then the minimal length a
3688 * given chunk can be. For example, a SACK chunk has invalid length
3689 * if it's length is set to be smaller then the size of sctp_sack_chunk_t.
3690 *
3691 * We inform the other end by sending an ABORT with a Protocol Violation
3692 * error code.
3693 *
3694 * Section: Not specified
3695 * Verification Tag: Nothing to do
3696 * Inputs
3697 * (endpoint, asoc, chunk)
3698 *
3699 * Outputs
3700 * (reply_msg, msg_up, counters)
3701 *
3702 * Generate an ABORT chunk and terminate the association.
3703 */
Adrian Bunk52c1da32005-06-23 22:05:33 -07003704static sctp_disposition_t sctp_sf_violation_chunklen(
3705 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003706 const struct sctp_association *asoc,
3707 const sctp_subtype_t type,
3708 void *arg,
3709 sctp_cmd_seq_t *commands)
3710{
3711 struct sctp_chunk *chunk = arg;
3712 struct sctp_chunk *abort = NULL;
3713 char err_str[]="The following chunk had invalid length:";
3714
3715 /* Make the abort chunk. */
3716 abort = sctp_make_abort_violation(asoc, chunk, err_str,
3717 sizeof(err_str));
3718 if (!abort)
3719 goto nomem;
3720
3721 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
3722 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
3723
3724 if (asoc->state <= SCTP_STATE_COOKIE_ECHOED) {
3725 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3726 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07003727 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
3728 SCTP_ERROR(ECONNREFUSED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003729 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
3730 SCTP_U32(SCTP_ERROR_PROTO_VIOLATION));
3731 } else {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07003732 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
3733 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003734 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
3735 SCTP_U32(SCTP_ERROR_PROTO_VIOLATION));
3736 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3737 }
3738
3739 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
3740
3741 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
3742
3743 return SCTP_DISPOSITION_ABORT;
3744
3745nomem:
3746 return SCTP_DISPOSITION_NOMEM;
3747}
3748
3749/***************************************************************************
3750 * These are the state functions for handling primitive (Section 10) events.
3751 ***************************************************************************/
3752/*
3753 * sctp_sf_do_prm_asoc
3754 *
3755 * Section: 10.1 ULP-to-SCTP
3756 * B) Associate
3757 *
3758 * Format: ASSOCIATE(local SCTP instance name, destination transport addr,
3759 * outbound stream count)
3760 * -> association id [,destination transport addr list] [,outbound stream
3761 * count]
3762 *
3763 * This primitive allows the upper layer to initiate an association to a
3764 * specific peer endpoint.
3765 *
3766 * The peer endpoint shall be specified by one of the transport addresses
3767 * which defines the endpoint (see Section 1.4). If the local SCTP
3768 * instance has not been initialized, the ASSOCIATE is considered an
3769 * error.
3770 * [This is not relevant for the kernel implementation since we do all
3771 * initialization at boot time. It we hadn't initialized we wouldn't
3772 * get anywhere near this code.]
3773 *
3774 * An association id, which is a local handle to the SCTP association,
3775 * will be returned on successful establishment of the association. If
3776 * SCTP is not able to open an SCTP association with the peer endpoint,
3777 * an error is returned.
3778 * [In the kernel implementation, the struct sctp_association needs to
3779 * be created BEFORE causing this primitive to run.]
3780 *
3781 * Other association parameters may be returned, including the
3782 * complete destination transport addresses of the peer as well as the
3783 * outbound stream count of the local endpoint. One of the transport
3784 * address from the returned destination addresses will be selected by
3785 * the local endpoint as default primary path for sending SCTP packets
3786 * to this peer. The returned "destination transport addr list" can
3787 * be used by the ULP to change the default primary path or to force
3788 * sending a packet to a specific transport address. [All of this
3789 * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING
3790 * function.]
3791 *
3792 * Mandatory attributes:
3793 *
3794 * o local SCTP instance name - obtained from the INITIALIZE operation.
3795 * [This is the argument asoc.]
3796 * o destination transport addr - specified as one of the transport
3797 * addresses of the peer endpoint with which the association is to be
3798 * established.
3799 * [This is asoc->peer.active_path.]
3800 * o outbound stream count - the number of outbound streams the ULP
3801 * would like to open towards this peer endpoint.
3802 * [BUG: This is not currently implemented.]
3803 * Optional attributes:
3804 *
3805 * None.
3806 *
3807 * The return value is a disposition.
3808 */
3809sctp_disposition_t sctp_sf_do_prm_asoc(const struct sctp_endpoint *ep,
3810 const struct sctp_association *asoc,
3811 const sctp_subtype_t type,
3812 void *arg,
3813 sctp_cmd_seq_t *commands)
3814{
3815 struct sctp_chunk *repl;
3816
3817 /* The comment below says that we enter COOKIE-WAIT AFTER
3818 * sending the INIT, but that doesn't actually work in our
3819 * implementation...
3820 */
3821 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3822 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
3823
3824 /* RFC 2960 5.1 Normal Establishment of an Association
3825 *
3826 * A) "A" first sends an INIT chunk to "Z". In the INIT, "A"
3827 * must provide its Verification Tag (Tag_A) in the Initiate
3828 * Tag field. Tag_A SHOULD be a random number in the range of
3829 * 1 to 4294967295 (see 5.3.1 for Tag value selection). ...
3830 */
3831
3832 repl = sctp_make_init(asoc, &asoc->base.bind_addr, GFP_ATOMIC, 0);
3833 if (!repl)
3834 goto nomem;
3835
3836 /* Cast away the const modifier, as we want to just
3837 * rerun it through as a sideffect.
3838 */
3839 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC,
3840 SCTP_ASOC((struct sctp_association *) asoc));
3841
Frank Filz3f7a87d2005-06-20 13:14:57 -07003842 /* Choose transport for INIT. */
3843 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
3844 SCTP_CHUNK(repl));
3845
Linus Torvalds1da177e2005-04-16 15:20:36 -07003846 /* After sending the INIT, "A" starts the T1-init timer and
3847 * enters the COOKIE-WAIT state.
3848 */
3849 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
3850 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
3851 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
3852 return SCTP_DISPOSITION_CONSUME;
3853
3854nomem:
3855 return SCTP_DISPOSITION_NOMEM;
3856}
3857
3858/*
3859 * Process the SEND primitive.
3860 *
3861 * Section: 10.1 ULP-to-SCTP
3862 * E) Send
3863 *
3864 * Format: SEND(association id, buffer address, byte count [,context]
3865 * [,stream id] [,life time] [,destination transport address]
3866 * [,unorder flag] [,no-bundle flag] [,payload protocol-id] )
3867 * -> result
3868 *
3869 * This is the main method to send user data via SCTP.
3870 *
3871 * Mandatory attributes:
3872 *
3873 * o association id - local handle to the SCTP association
3874 *
3875 * o buffer address - the location where the user message to be
3876 * transmitted is stored;
3877 *
3878 * o byte count - The size of the user data in number of bytes;
3879 *
3880 * Optional attributes:
3881 *
3882 * o context - an optional 32 bit integer that will be carried in the
3883 * sending failure notification to the ULP if the transportation of
3884 * this User Message fails.
3885 *
3886 * o stream id - to indicate which stream to send the data on. If not
3887 * specified, stream 0 will be used.
3888 *
3889 * o life time - specifies the life time of the user data. The user data
3890 * will not be sent by SCTP after the life time expires. This
3891 * parameter can be used to avoid efforts to transmit stale
3892 * user messages. SCTP notifies the ULP if the data cannot be
3893 * initiated to transport (i.e. sent to the destination via SCTP's
3894 * send primitive) within the life time variable. However, the
3895 * user data will be transmitted if SCTP has attempted to transmit a
3896 * chunk before the life time expired.
3897 *
3898 * o destination transport address - specified as one of the destination
3899 * transport addresses of the peer endpoint to which this packet
3900 * should be sent. Whenever possible, SCTP should use this destination
3901 * transport address for sending the packets, instead of the current
3902 * primary path.
3903 *
3904 * o unorder flag - this flag, if present, indicates that the user
3905 * would like the data delivered in an unordered fashion to the peer
3906 * (i.e., the U flag is set to 1 on all DATA chunks carrying this
3907 * message).
3908 *
3909 * o no-bundle flag - instructs SCTP not to bundle this user data with
3910 * other outbound DATA chunks. SCTP MAY still bundle even when
3911 * this flag is present, when faced with network congestion.
3912 *
3913 * o payload protocol-id - A 32 bit unsigned integer that is to be
3914 * passed to the peer indicating the type of payload protocol data
3915 * being transmitted. This value is passed as opaque data by SCTP.
3916 *
3917 * The return value is the disposition.
3918 */
3919sctp_disposition_t sctp_sf_do_prm_send(const struct sctp_endpoint *ep,
3920 const struct sctp_association *asoc,
3921 const sctp_subtype_t type,
3922 void *arg,
3923 sctp_cmd_seq_t *commands)
3924{
3925 struct sctp_chunk *chunk = arg;
3926
3927 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
3928 return SCTP_DISPOSITION_CONSUME;
3929}
3930
3931/*
3932 * Process the SHUTDOWN primitive.
3933 *
3934 * Section: 10.1:
3935 * C) Shutdown
3936 *
3937 * Format: SHUTDOWN(association id)
3938 * -> result
3939 *
3940 * Gracefully closes an association. Any locally queued user data
3941 * will be delivered to the peer. The association will be terminated only
3942 * after the peer acknowledges all the SCTP packets sent. A success code
3943 * will be returned on successful termination of the association. If
3944 * attempting to terminate the association results in a failure, an error
3945 * code shall be returned.
3946 *
3947 * Mandatory attributes:
3948 *
3949 * o association id - local handle to the SCTP association
3950 *
3951 * Optional attributes:
3952 *
3953 * None.
3954 *
3955 * The return value is the disposition.
3956 */
3957sctp_disposition_t sctp_sf_do_9_2_prm_shutdown(
3958 const struct sctp_endpoint *ep,
3959 const struct sctp_association *asoc,
3960 const sctp_subtype_t type,
3961 void *arg,
3962 sctp_cmd_seq_t *commands)
3963{
3964 int disposition;
3965
3966 /* From 9.2 Shutdown of an Association
3967 * Upon receipt of the SHUTDOWN primitive from its upper
3968 * layer, the endpoint enters SHUTDOWN-PENDING state and
3969 * remains there until all outstanding data has been
3970 * acknowledged by its peer. The endpoint accepts no new data
3971 * from its upper layer, but retransmits data to the far end
3972 * if necessary to fill gaps.
3973 */
3974 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3975 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
3976
3977 /* sctpimpguide-05 Section 2.12.2
3978 * The sender of the SHUTDOWN MAY also start an overall guard timer
3979 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
3980 */
3981 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
3982 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
3983
3984 disposition = SCTP_DISPOSITION_CONSUME;
3985 if (sctp_outq_is_empty(&asoc->outqueue)) {
3986 disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type,
3987 arg, commands);
3988 }
3989 return disposition;
3990}
3991
3992/*
3993 * Process the ABORT primitive.
3994 *
3995 * Section: 10.1:
3996 * C) Abort
3997 *
3998 * Format: Abort(association id [, cause code])
3999 * -> result
4000 *
4001 * Ungracefully closes an association. Any locally queued user data
4002 * will be discarded and an ABORT chunk is sent to the peer. A success code
4003 * will be returned on successful abortion of the association. If
4004 * attempting to abort the association results in a failure, an error
4005 * code shall be returned.
4006 *
4007 * Mandatory attributes:
4008 *
4009 * o association id - local handle to the SCTP association
4010 *
4011 * Optional attributes:
4012 *
4013 * o cause code - reason of the abort to be passed to the peer
4014 *
4015 * None.
4016 *
4017 * The return value is the disposition.
4018 */
4019sctp_disposition_t sctp_sf_do_9_1_prm_abort(
4020 const struct sctp_endpoint *ep,
4021 const struct sctp_association *asoc,
4022 const sctp_subtype_t type,
4023 void *arg,
4024 sctp_cmd_seq_t *commands)
4025{
4026 /* From 9.1 Abort of an Association
4027 * Upon receipt of the ABORT primitive from its upper
4028 * layer, the endpoint enters CLOSED state and
4029 * discard all outstanding data has been
4030 * acknowledged by its peer. The endpoint accepts no new data
4031 * from its upper layer, but retransmits data to the far end
4032 * if necessary to fill gaps.
4033 */
4034 struct msghdr *msg = arg;
4035 struct sctp_chunk *abort;
4036 sctp_disposition_t retval;
4037
4038 retval = SCTP_DISPOSITION_CONSUME;
4039
4040 /* Generate ABORT chunk to send the peer. */
4041 abort = sctp_make_abort_user(asoc, NULL, msg);
4042 if (!abort)
4043 retval = SCTP_DISPOSITION_NOMEM;
4044 else
4045 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4046
4047 /* Even if we can't send the ABORT due to low memory delete the
4048 * TCB. This is a departure from our typical NOMEM handling.
4049 */
4050
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004051 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4052 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004053 /* Delete the established association. */
4054 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4055 SCTP_U32(SCTP_ERROR_USER_ABORT));
4056
4057 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4058 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
4059
4060 return retval;
4061}
4062
4063/* We tried an illegal operation on an association which is closed. */
4064sctp_disposition_t sctp_sf_error_closed(const struct sctp_endpoint *ep,
4065 const struct sctp_association *asoc,
4066 const sctp_subtype_t type,
4067 void *arg,
4068 sctp_cmd_seq_t *commands)
4069{
4070 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, SCTP_ERROR(-EINVAL));
4071 return SCTP_DISPOSITION_CONSUME;
4072}
4073
4074/* We tried an illegal operation on an association which is shutting
4075 * down.
4076 */
4077sctp_disposition_t sctp_sf_error_shutdown(const struct sctp_endpoint *ep,
4078 const struct sctp_association *asoc,
4079 const sctp_subtype_t type,
4080 void *arg,
4081 sctp_cmd_seq_t *commands)
4082{
4083 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR,
4084 SCTP_ERROR(-ESHUTDOWN));
4085 return SCTP_DISPOSITION_CONSUME;
4086}
4087
4088/*
4089 * sctp_cookie_wait_prm_shutdown
4090 *
4091 * Section: 4 Note: 2
4092 * Verification Tag:
4093 * Inputs
4094 * (endpoint, asoc)
4095 *
4096 * The RFC does not explicitly address this issue, but is the route through the
4097 * state table when someone issues a shutdown while in COOKIE_WAIT state.
4098 *
4099 * Outputs
4100 * (timers)
4101 */
4102sctp_disposition_t sctp_sf_cookie_wait_prm_shutdown(
4103 const struct sctp_endpoint *ep,
4104 const struct sctp_association *asoc,
4105 const sctp_subtype_t type,
4106 void *arg,
4107 sctp_cmd_seq_t *commands)
4108{
4109 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4110 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4111
4112 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4113 SCTP_STATE(SCTP_STATE_CLOSED));
4114
4115 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
4116
4117 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
4118
4119 return SCTP_DISPOSITION_DELETE_TCB;
4120}
4121
4122/*
4123 * sctp_cookie_echoed_prm_shutdown
4124 *
4125 * Section: 4 Note: 2
4126 * Verification Tag:
4127 * Inputs
4128 * (endpoint, asoc)
4129 *
4130 * The RFC does not explcitly address this issue, but is the route through the
4131 * state table when someone issues a shutdown while in COOKIE_ECHOED state.
4132 *
4133 * Outputs
4134 * (timers)
4135 */
4136sctp_disposition_t sctp_sf_cookie_echoed_prm_shutdown(
4137 const struct sctp_endpoint *ep,
4138 const struct sctp_association *asoc,
4139 const sctp_subtype_t type,
4140 void *arg, sctp_cmd_seq_t *commands)
4141{
4142 /* There is a single T1 timer, so we should be able to use
4143 * common function with the COOKIE-WAIT state.
4144 */
4145 return sctp_sf_cookie_wait_prm_shutdown(ep, asoc, type, arg, commands);
4146}
4147
4148/*
4149 * sctp_sf_cookie_wait_prm_abort
4150 *
4151 * Section: 4 Note: 2
4152 * Verification Tag:
4153 * Inputs
4154 * (endpoint, asoc)
4155 *
4156 * The RFC does not explicitly address this issue, but is the route through the
4157 * state table when someone issues an abort while in COOKIE_WAIT state.
4158 *
4159 * Outputs
4160 * (timers)
4161 */
4162sctp_disposition_t sctp_sf_cookie_wait_prm_abort(
4163 const struct sctp_endpoint *ep,
4164 const struct sctp_association *asoc,
4165 const sctp_subtype_t type,
4166 void *arg,
4167 sctp_cmd_seq_t *commands)
4168{
4169 struct msghdr *msg = arg;
4170 struct sctp_chunk *abort;
4171 sctp_disposition_t retval;
4172
4173 /* Stop T1-init timer */
4174 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4175 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4176 retval = SCTP_DISPOSITION_CONSUME;
4177
4178 /* Generate ABORT chunk to send the peer */
4179 abort = sctp_make_abort_user(asoc, NULL, msg);
4180 if (!abort)
4181 retval = SCTP_DISPOSITION_NOMEM;
4182 else
4183 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4184
4185 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4186 SCTP_STATE(SCTP_STATE_CLOSED));
4187
4188 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4189
4190 /* Even if we can't send the ABORT due to low memory delete the
4191 * TCB. This is a departure from our typical NOMEM handling.
4192 */
4193
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004194 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4195 SCTP_ERROR(ECONNREFUSED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004196 /* Delete the established association. */
4197 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
4198 SCTP_U32(SCTP_ERROR_USER_ABORT));
4199
4200 return retval;
4201}
4202
4203/*
4204 * sctp_sf_cookie_echoed_prm_abort
4205 *
4206 * Section: 4 Note: 3
4207 * Verification Tag:
4208 * Inputs
4209 * (endpoint, asoc)
4210 *
4211 * The RFC does not explcitly address this issue, but is the route through the
4212 * state table when someone issues an abort while in COOKIE_ECHOED state.
4213 *
4214 * Outputs
4215 * (timers)
4216 */
4217sctp_disposition_t sctp_sf_cookie_echoed_prm_abort(
4218 const struct sctp_endpoint *ep,
4219 const struct sctp_association *asoc,
4220 const sctp_subtype_t type,
4221 void *arg,
4222 sctp_cmd_seq_t *commands)
4223{
4224 /* There is a single T1 timer, so we should be able to use
4225 * common function with the COOKIE-WAIT state.
4226 */
4227 return sctp_sf_cookie_wait_prm_abort(ep, asoc, type, arg, commands);
4228}
4229
4230/*
4231 * sctp_sf_shutdown_pending_prm_abort
4232 *
4233 * Inputs
4234 * (endpoint, asoc)
4235 *
4236 * The RFC does not explicitly address this issue, but is the route through the
4237 * state table when someone issues an abort while in SHUTDOWN-PENDING state.
4238 *
4239 * Outputs
4240 * (timers)
4241 */
4242sctp_disposition_t sctp_sf_shutdown_pending_prm_abort(
4243 const struct sctp_endpoint *ep,
4244 const struct sctp_association *asoc,
4245 const sctp_subtype_t type,
4246 void *arg,
4247 sctp_cmd_seq_t *commands)
4248{
4249 /* Stop the T5-shutdown guard timer. */
4250 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4251 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4252
4253 return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands);
4254}
4255
4256/*
4257 * sctp_sf_shutdown_sent_prm_abort
4258 *
4259 * Inputs
4260 * (endpoint, asoc)
4261 *
4262 * The RFC does not explicitly address this issue, but is the route through the
4263 * state table when someone issues an abort while in SHUTDOWN-SENT state.
4264 *
4265 * Outputs
4266 * (timers)
4267 */
4268sctp_disposition_t sctp_sf_shutdown_sent_prm_abort(
4269 const struct sctp_endpoint *ep,
4270 const struct sctp_association *asoc,
4271 const sctp_subtype_t type,
4272 void *arg,
4273 sctp_cmd_seq_t *commands)
4274{
4275 /* Stop the T2-shutdown timer. */
4276 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4277 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4278
4279 /* Stop the T5-shutdown guard timer. */
4280 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4281 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4282
4283 return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands);
4284}
4285
4286/*
4287 * sctp_sf_cookie_echoed_prm_abort
4288 *
4289 * Inputs
4290 * (endpoint, asoc)
4291 *
4292 * The RFC does not explcitly address this issue, but is the route through the
4293 * state table when someone issues an abort while in COOKIE_ECHOED state.
4294 *
4295 * Outputs
4296 * (timers)
4297 */
4298sctp_disposition_t sctp_sf_shutdown_ack_sent_prm_abort(
4299 const struct sctp_endpoint *ep,
4300 const struct sctp_association *asoc,
4301 const sctp_subtype_t type,
4302 void *arg,
4303 sctp_cmd_seq_t *commands)
4304{
4305 /* The same T2 timer, so we should be able to use
4306 * common function with the SHUTDOWN-SENT state.
4307 */
4308 return sctp_sf_shutdown_sent_prm_abort(ep, asoc, type, arg, commands);
4309}
4310
4311/*
4312 * Process the REQUESTHEARTBEAT primitive
4313 *
4314 * 10.1 ULP-to-SCTP
4315 * J) Request Heartbeat
4316 *
4317 * Format: REQUESTHEARTBEAT(association id, destination transport address)
4318 *
4319 * -> result
4320 *
4321 * Instructs the local endpoint to perform a HeartBeat on the specified
4322 * destination transport address of the given association. The returned
4323 * result should indicate whether the transmission of the HEARTBEAT
4324 * chunk to the destination address is successful.
4325 *
4326 * Mandatory attributes:
4327 *
4328 * o association id - local handle to the SCTP association
4329 *
4330 * o destination transport address - the transport address of the
4331 * association on which a heartbeat should be issued.
4332 */
4333sctp_disposition_t sctp_sf_do_prm_requestheartbeat(
4334 const struct sctp_endpoint *ep,
4335 const struct sctp_association *asoc,
4336 const sctp_subtype_t type,
4337 void *arg,
4338 sctp_cmd_seq_t *commands)
4339{
4340 return sctp_sf_heartbeat(ep, asoc, type, (struct sctp_transport *)arg,
4341 commands);
4342}
4343
4344/*
4345 * ADDIP Section 4.1 ASCONF Chunk Procedures
4346 * When an endpoint has an ASCONF signaled change to be sent to the
4347 * remote endpoint it should do A1 to A9
4348 */
4349sctp_disposition_t sctp_sf_do_prm_asconf(const struct sctp_endpoint *ep,
4350 const struct sctp_association *asoc,
4351 const sctp_subtype_t type,
4352 void *arg,
4353 sctp_cmd_seq_t *commands)
4354{
4355 struct sctp_chunk *chunk = arg;
4356
4357 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
4358 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4359 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
4360 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
4361 return SCTP_DISPOSITION_CONSUME;
4362}
4363
4364/*
4365 * Ignore the primitive event
4366 *
4367 * The return value is the disposition of the primitive.
4368 */
4369sctp_disposition_t sctp_sf_ignore_primitive(
4370 const struct sctp_endpoint *ep,
4371 const struct sctp_association *asoc,
4372 const sctp_subtype_t type,
4373 void *arg,
4374 sctp_cmd_seq_t *commands)
4375{
4376 SCTP_DEBUG_PRINTK("Primitive type %d is ignored.\n", type.primitive);
4377 return SCTP_DISPOSITION_DISCARD;
4378}
4379
4380/***************************************************************************
4381 * These are the state functions for the OTHER events.
4382 ***************************************************************************/
4383
4384/*
4385 * Start the shutdown negotiation.
4386 *
4387 * From Section 9.2:
4388 * Once all its outstanding data has been acknowledged, the endpoint
4389 * shall send a SHUTDOWN chunk to its peer including in the Cumulative
4390 * TSN Ack field the last sequential TSN it has received from the peer.
4391 * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT
4392 * state. If the timer expires, the endpoint must re-send the SHUTDOWN
4393 * with the updated last sequential TSN received from its peer.
4394 *
4395 * The return value is the disposition.
4396 */
4397sctp_disposition_t sctp_sf_do_9_2_start_shutdown(
4398 const struct sctp_endpoint *ep,
4399 const struct sctp_association *asoc,
4400 const sctp_subtype_t type,
4401 void *arg,
4402 sctp_cmd_seq_t *commands)
4403{
4404 struct sctp_chunk *reply;
4405
4406 /* Once all its outstanding data has been acknowledged, the
4407 * endpoint shall send a SHUTDOWN chunk to its peer including
4408 * in the Cumulative TSN Ack field the last sequential TSN it
4409 * has received from the peer.
4410 */
4411 reply = sctp_make_shutdown(asoc, NULL);
4412 if (!reply)
4413 goto nomem;
4414
4415 /* Set the transport for the SHUTDOWN chunk and the timeout for the
4416 * T2-shutdown timer.
4417 */
4418 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
4419
4420 /* It shall then start the T2-shutdown timer */
4421 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4422 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4423
4424 if (asoc->autoclose)
4425 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4426 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
4427
4428 /* and enter the SHUTDOWN-SENT state. */
4429 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4430 SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT));
4431
4432 /* sctp-implguide 2.10 Issues with Heartbeating and failover
4433 *
4434 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
4435 * or SHUTDOWN-ACK.
4436 */
4437 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
4438
4439 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
4440
4441 return SCTP_DISPOSITION_CONSUME;
4442
4443nomem:
4444 return SCTP_DISPOSITION_NOMEM;
4445}
4446
4447/*
4448 * Generate a SHUTDOWN ACK now that everything is SACK'd.
4449 *
4450 * From Section 9.2:
4451 *
4452 * If it has no more outstanding DATA chunks, the SHUTDOWN receiver
4453 * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own,
4454 * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the
4455 * endpoint must re-send the SHUTDOWN ACK.
4456 *
4457 * The return value is the disposition.
4458 */
4459sctp_disposition_t sctp_sf_do_9_2_shutdown_ack(
4460 const struct sctp_endpoint *ep,
4461 const struct sctp_association *asoc,
4462 const sctp_subtype_t type,
4463 void *arg,
4464 sctp_cmd_seq_t *commands)
4465{
4466 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
4467 struct sctp_chunk *reply;
4468
4469 /* There are 2 ways of getting here:
4470 * 1) called in response to a SHUTDOWN chunk
4471 * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued.
4472 *
4473 * For the case (2), the arg parameter is set to NULL. We need
4474 * to check that we have a chunk before accessing it's fields.
4475 */
4476 if (chunk) {
4477 if (!sctp_vtag_verify(chunk, asoc))
4478 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
4479
4480 /* Make sure that the SHUTDOWN chunk has a valid length. */
4481 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_shutdown_chunk_t)))
4482 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
4483 commands);
4484 }
4485
4486 /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
4487 * shall send a SHUTDOWN ACK ...
4488 */
4489 reply = sctp_make_shutdown_ack(asoc, chunk);
4490 if (!reply)
4491 goto nomem;
4492
4493 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
4494 * the T2-shutdown timer.
4495 */
4496 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
4497
4498 /* and start/restart a T2-shutdown timer of its own, */
4499 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
4500 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4501
4502 if (asoc->autoclose)
4503 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4504 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
4505
4506 /* Enter the SHUTDOWN-ACK-SENT state. */
4507 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4508 SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT));
4509
4510 /* sctp-implguide 2.10 Issues with Heartbeating and failover
4511 *
4512 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
4513 * or SHUTDOWN-ACK.
4514 */
4515 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
4516
4517 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
4518
4519 return SCTP_DISPOSITION_CONSUME;
4520
4521nomem:
4522 return SCTP_DISPOSITION_NOMEM;
4523}
4524
4525/*
4526 * Ignore the event defined as other
4527 *
4528 * The return value is the disposition of the event.
4529 */
4530sctp_disposition_t sctp_sf_ignore_other(const struct sctp_endpoint *ep,
4531 const struct sctp_association *asoc,
4532 const sctp_subtype_t type,
4533 void *arg,
4534 sctp_cmd_seq_t *commands)
4535{
4536 SCTP_DEBUG_PRINTK("The event other type %d is ignored\n", type.other);
4537 return SCTP_DISPOSITION_DISCARD;
4538}
4539
4540/************************************************************
4541 * These are the state functions for handling timeout events.
4542 ************************************************************/
4543
4544/*
4545 * RTX Timeout
4546 *
4547 * Section: 6.3.3 Handle T3-rtx Expiration
4548 *
4549 * Whenever the retransmission timer T3-rtx expires for a destination
4550 * address, do the following:
4551 * [See below]
4552 *
4553 * The return value is the disposition of the chunk.
4554 */
4555sctp_disposition_t sctp_sf_do_6_3_3_rtx(const struct sctp_endpoint *ep,
4556 const struct sctp_association *asoc,
4557 const sctp_subtype_t type,
4558 void *arg,
4559 sctp_cmd_seq_t *commands)
4560{
4561 struct sctp_transport *transport = arg;
4562
4563 if (asoc->overall_error_count >= asoc->max_retrans) {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004564 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4565 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004566 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
4567 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4568 SCTP_U32(SCTP_ERROR_NO_ERROR));
4569 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4570 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
4571 return SCTP_DISPOSITION_DELETE_TCB;
4572 }
4573
4574 /* E1) For the destination address for which the timer
4575 * expires, adjust its ssthresh with rules defined in Section
4576 * 7.2.3 and set the cwnd <- MTU.
4577 */
4578
4579 /* E2) For the destination address for which the timer
4580 * expires, set RTO <- RTO * 2 ("back off the timer"). The
4581 * maximum value discussed in rule C7 above (RTO.max) may be
4582 * used to provide an upper bound to this doubling operation.
4583 */
4584
4585 /* E3) Determine how many of the earliest (i.e., lowest TSN)
4586 * outstanding DATA chunks for the address for which the
4587 * T3-rtx has expired will fit into a single packet, subject
4588 * to the MTU constraint for the path corresponding to the
4589 * destination transport address to which the retransmission
4590 * is being sent (this may be different from the address for
4591 * which the timer expires [see Section 6.4]). Call this
4592 * value K. Bundle and retransmit those K DATA chunks in a
4593 * single packet to the destination endpoint.
4594 *
4595 * Note: Any DATA chunks that were sent to the address for
4596 * which the T3-rtx timer expired but did not fit in one MTU
4597 * (rule E3 above), should be marked for retransmission and
4598 * sent as soon as cwnd allows (normally when a SACK arrives).
4599 */
4600
4601 /* NB: Rules E4 and F1 are implicit in R1. */
4602 sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN, SCTP_TRANSPORT(transport));
4603
4604 /* Do some failure management (Section 8.2). */
4605 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
4606
4607 return SCTP_DISPOSITION_CONSUME;
4608}
4609
4610/*
4611 * Generate delayed SACK on timeout
4612 *
4613 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
4614 *
4615 * The guidelines on delayed acknowledgement algorithm specified in
4616 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
4617 * acknowledgement SHOULD be generated for at least every second packet
4618 * (not every second DATA chunk) received, and SHOULD be generated
4619 * within 200 ms of the arrival of any unacknowledged DATA chunk. In
4620 * some situations it may be beneficial for an SCTP transmitter to be
4621 * more conservative than the algorithms detailed in this document
4622 * allow. However, an SCTP transmitter MUST NOT be more aggressive than
4623 * the following algorithms allow.
4624 */
4625sctp_disposition_t sctp_sf_do_6_2_sack(const struct sctp_endpoint *ep,
4626 const struct sctp_association *asoc,
4627 const sctp_subtype_t type,
4628 void *arg,
4629 sctp_cmd_seq_t *commands)
4630{
4631 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
4632 return SCTP_DISPOSITION_CONSUME;
4633}
4634
4635/*
Frank Filz3f7a87d2005-06-20 13:14:57 -07004636 * sctp_sf_t1_init_timer_expire
Linus Torvalds1da177e2005-04-16 15:20:36 -07004637 *
4638 * Section: 4 Note: 2
4639 * Verification Tag:
4640 * Inputs
4641 * (endpoint, asoc)
4642 *
4643 * RFC 2960 Section 4 Notes
4644 * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT
4645 * and re-start the T1-init timer without changing state. This MUST
4646 * be repeated up to 'Max.Init.Retransmits' times. After that, the
4647 * endpoint MUST abort the initialization process and report the
4648 * error to SCTP user.
4649 *
Frank Filz3f7a87d2005-06-20 13:14:57 -07004650 * Outputs
4651 * (timers, events)
4652 *
4653 */
4654sctp_disposition_t sctp_sf_t1_init_timer_expire(const struct sctp_endpoint *ep,
4655 const struct sctp_association *asoc,
4656 const sctp_subtype_t type,
4657 void *arg,
4658 sctp_cmd_seq_t *commands)
4659{
4660 struct sctp_chunk *repl = NULL;
4661 struct sctp_bind_addr *bp;
4662 int attempts = asoc->init_err_counter + 1;
4663
4664 SCTP_DEBUG_PRINTK("Timer T1 expired (INIT).\n");
4665
Vlad Yasevich81845c22006-01-30 15:59:54 -08004666 if (attempts <= asoc->max_init_attempts) {
Frank Filz3f7a87d2005-06-20 13:14:57 -07004667 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
4668 repl = sctp_make_init(asoc, bp, GFP_ATOMIC, 0);
4669 if (!repl)
4670 return SCTP_DISPOSITION_NOMEM;
4671
4672 /* Choose transport for INIT. */
4673 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
4674 SCTP_CHUNK(repl));
4675
4676 /* Issue a sideeffect to do the needed accounting. */
4677 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_RESTART,
4678 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4679
4680 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
4681 } else {
4682 SCTP_DEBUG_PRINTK("Giving up on INIT, attempts: %d"
4683 " max_init_attempts: %d\n",
4684 attempts, asoc->max_init_attempts);
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004685 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4686 SCTP_ERROR(ETIMEDOUT));
Frank Filz3f7a87d2005-06-20 13:14:57 -07004687 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
4688 SCTP_U32(SCTP_ERROR_NO_ERROR));
4689 return SCTP_DISPOSITION_DELETE_TCB;
4690 }
4691
4692 return SCTP_DISPOSITION_CONSUME;
4693}
4694
4695/*
4696 * sctp_sf_t1_cookie_timer_expire
4697 *
4698 * Section: 4 Note: 2
4699 * Verification Tag:
4700 * Inputs
4701 * (endpoint, asoc)
4702 *
4703 * RFC 2960 Section 4 Notes
4704 * 3) If the T1-cookie timer expires, the endpoint MUST retransmit
Linus Torvalds1da177e2005-04-16 15:20:36 -07004705 * COOKIE ECHO and re-start the T1-cookie timer without changing
4706 * state. This MUST be repeated up to 'Max.Init.Retransmits' times.
4707 * After that, the endpoint MUST abort the initialization process and
4708 * report the error to SCTP user.
4709 *
4710 * Outputs
4711 * (timers, events)
4712 *
4713 */
Frank Filz3f7a87d2005-06-20 13:14:57 -07004714sctp_disposition_t sctp_sf_t1_cookie_timer_expire(const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07004715 const struct sctp_association *asoc,
4716 const sctp_subtype_t type,
4717 void *arg,
4718 sctp_cmd_seq_t *commands)
4719{
Frank Filz3f7a87d2005-06-20 13:14:57 -07004720 struct sctp_chunk *repl = NULL;
4721 int attempts = asoc->init_err_counter + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004722
Frank Filz3f7a87d2005-06-20 13:14:57 -07004723 SCTP_DEBUG_PRINTK("Timer T1 expired (COOKIE-ECHO).\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07004724
Vlad Yasevich81845c22006-01-30 15:59:54 -08004725 if (attempts <= asoc->max_init_attempts) {
Frank Filz3f7a87d2005-06-20 13:14:57 -07004726 repl = sctp_make_cookie_echo(asoc, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004727 if (!repl)
Frank Filz3f7a87d2005-06-20 13:14:57 -07004728 return SCTP_DISPOSITION_NOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004729
4730 /* Issue a sideeffect to do the needed accounting. */
Frank Filz3f7a87d2005-06-20 13:14:57 -07004731 sctp_add_cmd_sf(commands, SCTP_CMD_COOKIEECHO_RESTART,
4732 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
4733
Linus Torvalds1da177e2005-04-16 15:20:36 -07004734 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
4735 } else {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004736 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4737 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004738 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
4739 SCTP_U32(SCTP_ERROR_NO_ERROR));
4740 return SCTP_DISPOSITION_DELETE_TCB;
4741 }
4742
4743 return SCTP_DISPOSITION_CONSUME;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004744}
4745
4746/* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN
4747 * with the updated last sequential TSN received from its peer.
4748 *
4749 * An endpoint should limit the number of retransmissions of the
4750 * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'.
4751 * If this threshold is exceeded the endpoint should destroy the TCB and
4752 * MUST report the peer endpoint unreachable to the upper layer (and
4753 * thus the association enters the CLOSED state). The reception of any
4754 * packet from its peer (i.e. as the peer sends all of its queued DATA
4755 * chunks) should clear the endpoint's retransmission count and restart
4756 * the T2-Shutdown timer, giving its peer ample opportunity to transmit
4757 * all of its queued DATA chunks that have not yet been sent.
4758 */
4759sctp_disposition_t sctp_sf_t2_timer_expire(const struct sctp_endpoint *ep,
4760 const struct sctp_association *asoc,
4761 const sctp_subtype_t type,
4762 void *arg,
4763 sctp_cmd_seq_t *commands)
4764{
4765 struct sctp_chunk *reply = NULL;
4766
4767 SCTP_DEBUG_PRINTK("Timer T2 expired.\n");
4768 if (asoc->overall_error_count >= asoc->max_retrans) {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004769 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4770 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004771 /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
4772 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4773 SCTP_U32(SCTP_ERROR_NO_ERROR));
4774 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4775 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
4776 return SCTP_DISPOSITION_DELETE_TCB;
4777 }
4778
4779 switch (asoc->state) {
4780 case SCTP_STATE_SHUTDOWN_SENT:
4781 reply = sctp_make_shutdown(asoc, NULL);
4782 break;
4783
4784 case SCTP_STATE_SHUTDOWN_ACK_SENT:
4785 reply = sctp_make_shutdown_ack(asoc, NULL);
4786 break;
4787
4788 default:
4789 BUG();
4790 break;
4791 };
4792
4793 if (!reply)
4794 goto nomem;
4795
4796 /* Do some failure management (Section 8.2). */
4797 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
4798 SCTP_TRANSPORT(asoc->shutdown_last_sent_to));
4799
4800 /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for
4801 * the T2-shutdown timer.
4802 */
4803 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
4804
4805 /* Restart the T2-shutdown timer. */
4806 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
4807 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4808 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
4809 return SCTP_DISPOSITION_CONSUME;
4810
4811nomem:
4812 return SCTP_DISPOSITION_NOMEM;
4813}
4814
4815/*
4816 * ADDIP Section 4.1 ASCONF CHunk Procedures
4817 * If the T4 RTO timer expires the endpoint should do B1 to B5
4818 */
4819sctp_disposition_t sctp_sf_t4_timer_expire(
4820 const struct sctp_endpoint *ep,
4821 const struct sctp_association *asoc,
4822 const sctp_subtype_t type,
4823 void *arg,
4824 sctp_cmd_seq_t *commands)
4825{
4826 struct sctp_chunk *chunk = asoc->addip_last_asconf;
4827 struct sctp_transport *transport = chunk->transport;
4828
4829 /* ADDIP 4.1 B1) Increment the error counters and perform path failure
4830 * detection on the appropriate destination address as defined in
4831 * RFC2960 [5] section 8.1 and 8.2.
4832 */
4833 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
4834
4835 /* Reconfig T4 timer and transport. */
4836 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
4837
4838 /* ADDIP 4.1 B2) Increment the association error counters and perform
4839 * endpoint failure detection on the association as defined in
4840 * RFC2960 [5] section 8.1 and 8.2.
4841 * association error counter is incremented in SCTP_CMD_STRIKE.
4842 */
4843 if (asoc->overall_error_count >= asoc->max_retrans) {
4844 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4845 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004846 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4847 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004848 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4849 SCTP_U32(SCTP_ERROR_NO_ERROR));
4850 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4851 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
4852 return SCTP_DISPOSITION_ABORT;
4853 }
4854
4855 /* ADDIP 4.1 B3) Back-off the destination address RTO value to which
4856 * the ASCONF chunk was sent by doubling the RTO timer value.
4857 * This is done in SCTP_CMD_STRIKE.
4858 */
4859
4860 /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible
4861 * choose an alternate destination address (please refer to RFC2960
4862 * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this
4863 * chunk, it MUST be the same (including its serial number) as the last
4864 * ASCONF sent.
4865 */
4866 sctp_chunk_hold(asoc->addip_last_asconf);
4867 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4868 SCTP_CHUNK(asoc->addip_last_asconf));
4869
4870 /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different
4871 * destination is selected, then the RTO used will be that of the new
4872 * destination address.
4873 */
4874 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
4875 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
4876
4877 return SCTP_DISPOSITION_CONSUME;
4878}
4879
4880/* sctpimpguide-05 Section 2.12.2
4881 * The sender of the SHUTDOWN MAY also start an overall guard timer
4882 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
4883 * At the expiration of this timer the sender SHOULD abort the association
4884 * by sending an ABORT chunk.
4885 */
4886sctp_disposition_t sctp_sf_t5_timer_expire(const struct sctp_endpoint *ep,
4887 const struct sctp_association *asoc,
4888 const sctp_subtype_t type,
4889 void *arg,
4890 sctp_cmd_seq_t *commands)
4891{
4892 struct sctp_chunk *reply = NULL;
4893
4894 SCTP_DEBUG_PRINTK("Timer T5 expired.\n");
4895
4896 reply = sctp_make_abort(asoc, NULL, 0);
4897 if (!reply)
4898 goto nomem;
4899
4900 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004901 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4902 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004903 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4904 SCTP_U32(SCTP_ERROR_NO_ERROR));
4905
4906 return SCTP_DISPOSITION_DELETE_TCB;
4907nomem:
4908 return SCTP_DISPOSITION_NOMEM;
4909}
4910
4911/* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires,
4912 * the association is automatically closed by starting the shutdown process.
4913 * The work that needs to be done is same as when SHUTDOWN is initiated by
4914 * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown().
4915 */
4916sctp_disposition_t sctp_sf_autoclose_timer_expire(
4917 const struct sctp_endpoint *ep,
4918 const struct sctp_association *asoc,
4919 const sctp_subtype_t type,
4920 void *arg,
4921 sctp_cmd_seq_t *commands)
4922{
4923 int disposition;
4924
4925 /* From 9.2 Shutdown of an Association
4926 * Upon receipt of the SHUTDOWN primitive from its upper
4927 * layer, the endpoint enters SHUTDOWN-PENDING state and
4928 * remains there until all outstanding data has been
4929 * acknowledged by its peer. The endpoint accepts no new data
4930 * from its upper layer, but retransmits data to the far end
4931 * if necessary to fill gaps.
4932 */
4933 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4934 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
4935
4936 /* sctpimpguide-05 Section 2.12.2
4937 * The sender of the SHUTDOWN MAY also start an overall guard timer
4938 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
4939 */
4940 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4941 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4942 disposition = SCTP_DISPOSITION_CONSUME;
4943 if (sctp_outq_is_empty(&asoc->outqueue)) {
4944 disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type,
4945 arg, commands);
4946 }
4947 return disposition;
4948}
4949
4950/*****************************************************************************
4951 * These are sa state functions which could apply to all types of events.
4952 ****************************************************************************/
4953
4954/*
4955 * This table entry is not implemented.
4956 *
4957 * Inputs
4958 * (endpoint, asoc, chunk)
4959 *
4960 * The return value is the disposition of the chunk.
4961 */
4962sctp_disposition_t sctp_sf_not_impl(const struct sctp_endpoint *ep,
4963 const struct sctp_association *asoc,
4964 const sctp_subtype_t type,
4965 void *arg,
4966 sctp_cmd_seq_t *commands)
4967{
4968 return SCTP_DISPOSITION_NOT_IMPL;
4969}
4970
4971/*
4972 * This table entry represents a bug.
4973 *
4974 * Inputs
4975 * (endpoint, asoc, chunk)
4976 *
4977 * The return value is the disposition of the chunk.
4978 */
4979sctp_disposition_t sctp_sf_bug(const struct sctp_endpoint *ep,
4980 const struct sctp_association *asoc,
4981 const sctp_subtype_t type,
4982 void *arg,
4983 sctp_cmd_seq_t *commands)
4984{
4985 return SCTP_DISPOSITION_BUG;
4986}
4987
4988/*
4989 * This table entry represents the firing of a timer in the wrong state.
4990 * Since timer deletion cannot be guaranteed a timer 'may' end up firing
4991 * when the association is in the wrong state. This event should
4992 * be ignored, so as to prevent any rearming of the timer.
4993 *
4994 * Inputs
4995 * (endpoint, asoc, chunk)
4996 *
4997 * The return value is the disposition of the chunk.
4998 */
4999sctp_disposition_t sctp_sf_timer_ignore(const struct sctp_endpoint *ep,
5000 const struct sctp_association *asoc,
5001 const sctp_subtype_t type,
5002 void *arg,
5003 sctp_cmd_seq_t *commands)
5004{
5005 SCTP_DEBUG_PRINTK("Timer %d ignored.\n", type.chunk);
5006 return SCTP_DISPOSITION_CONSUME;
5007}
5008
5009/********************************************************************
5010 * 2nd Level Abstractions
5011 ********************************************************************/
5012
5013/* Pull the SACK chunk based on the SACK header. */
5014static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk)
5015{
5016 struct sctp_sackhdr *sack;
5017 unsigned int len;
5018 __u16 num_blocks;
5019 __u16 num_dup_tsns;
5020
5021 /* Protect ourselves from reading too far into
5022 * the skb from a bogus sender.
5023 */
5024 sack = (struct sctp_sackhdr *) chunk->skb->data;
5025
5026 num_blocks = ntohs(sack->num_gap_ack_blocks);
5027 num_dup_tsns = ntohs(sack->num_dup_tsns);
5028 len = sizeof(struct sctp_sackhdr);
5029 len += (num_blocks + num_dup_tsns) * sizeof(__u32);
5030 if (len > chunk->skb->len)
5031 return NULL;
5032
5033 skb_pull(chunk->skb, len);
5034
5035 return sack;
5036}
5037
5038/* Create an ABORT packet to be sent as a response, with the specified
5039 * error causes.
5040 */
5041static struct sctp_packet *sctp_abort_pkt_new(const struct sctp_endpoint *ep,
5042 const struct sctp_association *asoc,
5043 struct sctp_chunk *chunk,
5044 const void *payload,
5045 size_t paylen)
5046{
5047 struct sctp_packet *packet;
5048 struct sctp_chunk *abort;
5049
5050 packet = sctp_ootb_pkt_new(asoc, chunk);
5051
5052 if (packet) {
5053 /* Make an ABORT.
5054 * The T bit will be set if the asoc is NULL.
5055 */
5056 abort = sctp_make_abort(asoc, chunk, paylen);
5057 if (!abort) {
5058 sctp_ootb_pkt_free(packet);
5059 return NULL;
5060 }
Jerome Forissier047a2422005-04-28 11:58:43 -07005061
5062 /* Reflect vtag if T-Bit is set */
5063 if (sctp_test_T_bit(abort))
5064 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
5065
Linus Torvalds1da177e2005-04-16 15:20:36 -07005066 /* Add specified error causes, i.e., payload, to the
5067 * end of the chunk.
5068 */
5069 sctp_addto_chunk(abort, paylen, payload);
5070
5071 /* Set the skb to the belonging sock for accounting. */
5072 abort->skb->sk = ep->base.sk;
5073
5074 sctp_packet_append_chunk(packet, abort);
5075
5076 }
5077
5078 return packet;
5079}
5080
5081/* Allocate a packet for responding in the OOTB conditions. */
5082static struct sctp_packet *sctp_ootb_pkt_new(const struct sctp_association *asoc,
5083 const struct sctp_chunk *chunk)
5084{
5085 struct sctp_packet *packet;
5086 struct sctp_transport *transport;
5087 __u16 sport;
5088 __u16 dport;
5089 __u32 vtag;
5090
5091 /* Get the source and destination port from the inbound packet. */
5092 sport = ntohs(chunk->sctp_hdr->dest);
5093 dport = ntohs(chunk->sctp_hdr->source);
5094
5095 /* The V-tag is going to be the same as the inbound packet if no
5096 * association exists, otherwise, use the peer's vtag.
5097 */
5098 if (asoc) {
5099 vtag = asoc->peer.i.init_tag;
5100 } else {
5101 /* Special case the INIT and stale COOKIE_ECHO as there is no
5102 * vtag yet.
5103 */
5104 switch(chunk->chunk_hdr->type) {
5105 case SCTP_CID_INIT:
5106 {
5107 sctp_init_chunk_t *init;
5108
5109 init = (sctp_init_chunk_t *)chunk->chunk_hdr;
5110 vtag = ntohl(init->init_hdr.init_tag);
5111 break;
5112 }
5113 default:
5114 vtag = ntohl(chunk->sctp_hdr->vtag);
5115 break;
5116 }
5117 }
5118
5119 /* Make a transport for the bucket, Eliza... */
5120 transport = sctp_transport_new(sctp_source(chunk), GFP_ATOMIC);
5121 if (!transport)
5122 goto nomem;
5123
5124 /* Cache a route for the transport with the chunk's destination as
5125 * the source address.
5126 */
5127 sctp_transport_route(transport, (union sctp_addr *)&chunk->dest,
5128 sctp_sk(sctp_get_ctl_sock()));
5129
5130 packet = sctp_packet_init(&transport->packet, transport, sport, dport);
5131 packet = sctp_packet_config(packet, vtag, 0);
5132
5133 return packet;
5134
5135nomem:
5136 return NULL;
5137}
5138
5139/* Free the packet allocated earlier for responding in the OOTB condition. */
5140void sctp_ootb_pkt_free(struct sctp_packet *packet)
5141{
5142 sctp_transport_free(packet->transport);
5143}
5144
5145/* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */
5146static void sctp_send_stale_cookie_err(const struct sctp_endpoint *ep,
5147 const struct sctp_association *asoc,
5148 const struct sctp_chunk *chunk,
5149 sctp_cmd_seq_t *commands,
5150 struct sctp_chunk *err_chunk)
5151{
5152 struct sctp_packet *packet;
5153
5154 if (err_chunk) {
5155 packet = sctp_ootb_pkt_new(asoc, chunk);
5156 if (packet) {
5157 struct sctp_signed_cookie *cookie;
5158
5159 /* Override the OOTB vtag from the cookie. */
5160 cookie = chunk->subh.cookie_hdr;
5161 packet->vtag = cookie->c.peer_vtag;
5162
5163 /* Set the skb to the belonging sock for accounting. */
5164 err_chunk->skb->sk = ep->base.sk;
5165 sctp_packet_append_chunk(packet, err_chunk);
5166 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
5167 SCTP_PACKET(packet));
5168 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
5169 } else
5170 sctp_chunk_free (err_chunk);
5171 }
5172}
5173
5174
5175/* Process a data chunk */
5176static int sctp_eat_data(const struct sctp_association *asoc,
5177 struct sctp_chunk *chunk,
5178 sctp_cmd_seq_t *commands)
5179{
5180 sctp_datahdr_t *data_hdr;
5181 struct sctp_chunk *err;
5182 size_t datalen;
5183 sctp_verb_t deliver;
5184 int tmp;
5185 __u32 tsn;
Neil Horman049b3ff2005-11-11 16:08:24 -08005186 int account_value;
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005187 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
Neil Horman049b3ff2005-11-11 16:08:24 -08005188 struct sock *sk = asoc->base.sk;
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005189 int rcvbuf_over = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005190
5191 data_hdr = chunk->subh.data_hdr = (sctp_datahdr_t *)chunk->skb->data;
5192 skb_pull(chunk->skb, sizeof(sctp_datahdr_t));
5193
5194 tsn = ntohl(data_hdr->tsn);
5195 SCTP_DEBUG_PRINTK("eat_data: TSN 0x%x.\n", tsn);
5196
5197 /* ASSERT: Now skb->data is really the user data. */
5198
Neil Horman049b3ff2005-11-11 16:08:24 -08005199 /*
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005200 * If we are established, and we have used up our receive buffer
5201 * memory, think about droping the frame.
5202 * Note that we have an opportunity to improve performance here.
5203 * If we accept one chunk from an skbuff, we have to keep all the
5204 * memory of that skbuff around until the chunk is read into user
5205 * space. Therefore, once we accept 1 chunk we may as well accept all
5206 * remaining chunks in the skbuff. The data_accepted flag helps us do
5207 * that.
Neil Horman049b3ff2005-11-11 16:08:24 -08005208 */
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005209 if ((asoc->state == SCTP_STATE_ESTABLISHED) && (!chunk->data_accepted)) {
Neil Horman049b3ff2005-11-11 16:08:24 -08005210 /*
5211 * If the receive buffer policy is 1, then each
5212 * association can allocate up to sk_rcvbuf bytes
5213 * otherwise, all the associations in aggregate
5214 * may allocate up to sk_rcvbuf bytes
5215 */
5216 if (asoc->ep->rcvbuf_policy)
5217 account_value = atomic_read(&asoc->rmem_alloc);
5218 else
5219 account_value = atomic_read(&sk->sk_rmem_alloc);
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005220 if (account_value > sk->sk_rcvbuf) {
5221 /*
5222 * We need to make forward progress, even when we are
5223 * under memory pressure, so we always allow the
5224 * next tsn after the ctsn ack point to be accepted.
5225 * This lets us avoid deadlocks in which we have to
5226 * drop frames that would otherwise let us drain the
5227 * receive queue.
5228 */
5229 if ((sctp_tsnmap_get_ctsn(map) + 1) != tsn)
5230 return SCTP_IERROR_IGNORE_TSN;
Neil Horman049b3ff2005-11-11 16:08:24 -08005231
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005232 /*
5233 * We're going to accept the frame but we should renege
5234 * to make space for it. This will send us down that
5235 * path later in this function.
5236 */
5237 rcvbuf_over = 1;
5238 }
Neil Horman049b3ff2005-11-11 16:08:24 -08005239 }
5240
Linus Torvalds1da177e2005-04-16 15:20:36 -07005241 /* Process ECN based congestion.
5242 *
5243 * Since the chunk structure is reused for all chunks within
5244 * a packet, we use ecn_ce_done to track if we've already
5245 * done CE processing for this packet.
5246 *
5247 * We need to do ECN processing even if we plan to discard the
5248 * chunk later.
5249 */
5250
5251 if (!chunk->ecn_ce_done) {
5252 struct sctp_af *af;
5253 chunk->ecn_ce_done = 1;
5254
5255 af = sctp_get_af_specific(
5256 ipver2af(chunk->skb->nh.iph->version));
5257
5258 if (af && af->is_ce(chunk->skb) && asoc->peer.ecn_capable) {
5259 /* Do real work as sideffect. */
5260 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_CE,
5261 SCTP_U32(tsn));
5262 }
5263 }
5264
5265 tmp = sctp_tsnmap_check(&asoc->peer.tsn_map, tsn);
5266 if (tmp < 0) {
5267 /* The TSN is too high--silently discard the chunk and
5268 * count on it getting retransmitted later.
5269 */
5270 return SCTP_IERROR_HIGH_TSN;
5271 } else if (tmp > 0) {
5272 /* This is a duplicate. Record it. */
5273 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_DUP, SCTP_U32(tsn));
5274 return SCTP_IERROR_DUP_TSN;
5275 }
5276
5277 /* This is a new TSN. */
5278
5279 /* Discard if there is no room in the receive window.
5280 * Actually, allow a little bit of overflow (up to a MTU).
5281 */
5282 datalen = ntohs(chunk->chunk_hdr->length);
5283 datalen -= sizeof(sctp_data_chunk_t);
5284
5285 deliver = SCTP_CMD_CHUNK_ULP;
5286
5287 /* Think about partial delivery. */
5288 if ((datalen >= asoc->rwnd) && (!asoc->ulpq.pd_mode)) {
5289
5290 /* Even if we don't accept this chunk there is
5291 * memory pressure.
5292 */
5293 sctp_add_cmd_sf(commands, SCTP_CMD_PART_DELIVER, SCTP_NULL());
5294 }
5295
5296 /* Spill over rwnd a little bit. Note: While allowed, this spill over
5297 * seems a bit troublesome in that frag_point varies based on
5298 * PMTU. In cases, such as loopback, this might be a rather
5299 * large spill over.
Neil Hormand5b9f4c2006-06-17 22:59:03 -07005300 * NOTE: If we have a full receive buffer here, we only renege if
5301 * our receiver can still make progress without the tsn being
5302 * received. We do this because in the event that the associations
5303 * receive queue is empty we are filling a leading gap, and since
5304 * reneging moves the gap to the end of the tsn stream, we are likely
5305 * to stall again very shortly. Avoiding the renege when we fill a
5306 * leading gap is a good heuristic for avoiding such steady state
5307 * stalls.
Linus Torvalds1da177e2005-04-16 15:20:36 -07005308 */
5309 if (!asoc->rwnd || asoc->rwnd_over ||
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005310 (datalen > asoc->rwnd + asoc->frag_point) ||
Neil Hormand5b9f4c2006-06-17 22:59:03 -07005311 (rcvbuf_over && (!skb_queue_len(&sk->sk_receive_queue)))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07005312
5313 /* If this is the next TSN, consider reneging to make
5314 * room. Note: Playing nice with a confused sender. A
5315 * malicious sender can still eat up all our buffer
5316 * space and in the future we may want to detect and
5317 * do more drastic reneging.
5318 */
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005319 if (sctp_tsnmap_has_gap(map) &&
5320 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07005321 SCTP_DEBUG_PRINTK("Reneging for tsn:%u\n", tsn);
5322 deliver = SCTP_CMD_RENEGE;
5323 } else {
5324 SCTP_DEBUG_PRINTK("Discard tsn: %u len: %Zd, "
5325 "rwnd: %d\n", tsn, datalen,
5326 asoc->rwnd);
5327 return SCTP_IERROR_IGNORE_TSN;
5328 }
5329 }
5330
5331 /*
5332 * Section 3.3.10.9 No User Data (9)
5333 *
5334 * Cause of error
5335 * ---------------
5336 * No User Data: This error cause is returned to the originator of a
5337 * DATA chunk if a received DATA chunk has no user data.
5338 */
5339 if (unlikely(0 == datalen)) {
5340 err = sctp_make_abort_no_data(asoc, chunk, tsn);
5341 if (err) {
5342 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
5343 SCTP_CHUNK(err));
5344 }
5345 /* We are going to ABORT, so we might as well stop
5346 * processing the rest of the chunks in the packet.
5347 */
5348 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07005349 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5350 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005351 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5352 SCTP_U32(SCTP_ERROR_NO_DATA));
5353 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
5354 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
5355 return SCTP_IERROR_NO_DATA;
5356 }
5357
5358 /* If definately accepting the DATA chunk, record its TSN, otherwise
5359 * wait for renege processing.
5360 */
5361 if (SCTP_CMD_CHUNK_ULP == deliver)
5362 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_TSN, SCTP_U32(tsn));
5363
Sridhar Samudrala9faa7302006-07-21 14:49:07 -07005364 chunk->data_accepted = 1;
5365
Linus Torvalds1da177e2005-04-16 15:20:36 -07005366 /* Note: Some chunks may get overcounted (if we drop) or overcounted
5367 * if we renege and the chunk arrives again.
5368 */
5369 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
5370 SCTP_INC_STATS(SCTP_MIB_INUNORDERCHUNKS);
5371 else
5372 SCTP_INC_STATS(SCTP_MIB_INORDERCHUNKS);
5373
5374 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
5375 *
5376 * If an endpoint receive a DATA chunk with an invalid stream
5377 * identifier, it shall acknowledge the reception of the DATA chunk
5378 * following the normal procedure, immediately send an ERROR chunk
5379 * with cause set to "Invalid Stream Identifier" (See Section 3.3.10)
5380 * and discard the DATA chunk.
5381 */
5382 if (ntohs(data_hdr->stream) >= asoc->c.sinit_max_instreams) {
5383 err = sctp_make_op_error(asoc, chunk, SCTP_ERROR_INV_STRM,
5384 &data_hdr->stream,
5385 sizeof(data_hdr->stream));
5386 if (err)
5387 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
5388 SCTP_CHUNK(err));
5389 return SCTP_IERROR_BAD_STREAM;
5390 }
5391
5392 /* Send the data up to the user. Note: Schedule the
5393 * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK
5394 * chunk needs the updated rwnd.
5395 */
5396 sctp_add_cmd_sf(commands, deliver, SCTP_CHUNK(chunk));
5397
5398 return SCTP_IERROR_NO_ERROR;
5399}