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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* SCTP kernel reference Implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999-2000 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 * Copyright (c) 2001-2002 Intel Corp.
6 * Copyright (c) 2002 Nokia Corp.
7 *
8 * This file is part of the SCTP kernel reference Implementation
9 *
10 * This is part of the SCTP Linux Kernel Reference Implementation.
11 *
12 * These are the state functions for the state machine.
13 *
14 * The SCTP reference implementation is free software;
15 * you can redistribute it and/or modify it under the terms of
16 * the GNU General Public License as published by
17 * the Free Software Foundation; either version 2, or (at your option)
18 * any later version.
19 *
20 * The SCTP reference implementation is distributed in the hope that it
21 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
22 * ************************
23 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
24 * See the GNU General Public License for more details.
25 *
26 * You should have received a copy of the GNU General Public License
27 * along with GNU CC; see the file COPYING. If not, write to
28 * the Free Software Foundation, 59 Temple Place - Suite 330,
29 * Boston, MA 02111-1307, USA.
30 *
31 * Please send any bug reports or fixes you make to the
32 * email address(es):
33 * lksctp developers <lksctp-developers@lists.sourceforge.net>
34 *
35 * Or submit a bug report through the following website:
36 * http://www.sf.net/projects/lksctp
37 *
38 * Written or modified by:
39 * La Monte H.P. Yarroll <piggy@acm.org>
40 * Karl Knutson <karl@athena.chicago.il.us>
41 * Mathew Kotowsky <kotowsky@sctp.org>
42 * Sridhar Samudrala <samudrala@us.ibm.com>
43 * Jon Grimm <jgrimm@us.ibm.com>
44 * Hui Huang <hui.huang@nokia.com>
45 * Dajiang Zhang <dajiang.zhang@nokia.com>
46 * Daisy Chang <daisyc@us.ibm.com>
47 * Ardelle Fan <ardelle.fan@intel.com>
48 * Ryan Layer <rmlayer@us.ibm.com>
49 * Kevin Gao <kevin.gao@intel.com>
50 *
51 * Any bugs reported given to us we will try to fix... any fixes shared will
52 * be incorporated into the next SCTP release.
53 */
54
55#include <linux/types.h>
56#include <linux/kernel.h>
57#include <linux/ip.h>
58#include <linux/ipv6.h>
59#include <linux/net.h>
60#include <linux/inet.h>
61#include <net/sock.h>
62#include <net/inet_ecn.h>
63#include <linux/skbuff.h>
64#include <net/sctp/sctp.h>
65#include <net/sctp/sm.h>
66#include <net/sctp/structs.h>
67
68static struct sctp_packet *sctp_abort_pkt_new(const struct sctp_endpoint *ep,
69 const struct sctp_association *asoc,
70 struct sctp_chunk *chunk,
71 const void *payload,
72 size_t paylen);
73static int sctp_eat_data(const struct sctp_association *asoc,
74 struct sctp_chunk *chunk,
75 sctp_cmd_seq_t *commands);
76static struct sctp_packet *sctp_ootb_pkt_new(const struct sctp_association *asoc,
77 const struct sctp_chunk *chunk);
78static void sctp_send_stale_cookie_err(const struct sctp_endpoint *ep,
79 const struct sctp_association *asoc,
80 const struct sctp_chunk *chunk,
81 sctp_cmd_seq_t *commands,
82 struct sctp_chunk *err_chunk);
83static sctp_disposition_t sctp_sf_do_5_2_6_stale(const struct sctp_endpoint *ep,
84 const struct sctp_association *asoc,
85 const sctp_subtype_t type,
86 void *arg,
87 sctp_cmd_seq_t *commands);
88static sctp_disposition_t sctp_sf_shut_8_4_5(const struct sctp_endpoint *ep,
89 const struct sctp_association *asoc,
90 const sctp_subtype_t type,
91 void *arg,
92 sctp_cmd_seq_t *commands);
93static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk);
94
Adrian Bunk52c1da32005-06-23 22:05:33 -070095static sctp_disposition_t sctp_stop_t1_and_abort(sctp_cmd_seq_t *commands,
Al Virof94c0192006-11-20 17:00:25 -080096 __be16 error, int sk_err,
Adrian Bunk52c1da32005-06-23 22:05:33 -070097 const struct sctp_association *asoc,
98 struct sctp_transport *transport);
99
100static sctp_disposition_t sctp_sf_violation_chunklen(
101 const struct sctp_endpoint *ep,
102 const struct sctp_association *asoc,
103 const sctp_subtype_t type,
104 void *arg,
105 sctp_cmd_seq_t *commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106
107/* Small helper function that checks if the chunk length
108 * is of the appropriate length. The 'required_length' argument
109 * is set to be the size of a specific chunk we are testing.
110 * Return Values: 1 = Valid length
111 * 0 = Invalid length
112 *
113 */
114static inline int
115sctp_chunk_length_valid(struct sctp_chunk *chunk,
116 __u16 required_length)
117{
118 __u16 chunk_length = ntohs(chunk->chunk_hdr->length);
119
120 if (unlikely(chunk_length < required_length))
121 return 0;
122
123 return 1;
124}
125
126/**********************************************************
127 * These are the state functions for handling chunk events.
128 **********************************************************/
129
130/*
131 * Process the final SHUTDOWN COMPLETE.
132 *
133 * Section: 4 (C) (diagram), 9.2
134 * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify
135 * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be
136 * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint
137 * should stop the T2-shutdown timer and remove all knowledge of the
138 * association (and thus the association enters the CLOSED state).
139 *
Jerome Forissier047a2422005-04-28 11:58:43 -0700140 * Verification Tag: 8.5.1(C), sctpimpguide 2.41.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141 * C) Rules for packet carrying SHUTDOWN COMPLETE:
142 * ...
Jerome Forissier047a2422005-04-28 11:58:43 -0700143 * - The receiver of a SHUTDOWN COMPLETE shall accept the packet
144 * if the Verification Tag field of the packet matches its own tag and
145 * the T bit is not set
146 * OR
147 * it is set to its peer's tag and the T bit is set in the Chunk
148 * Flags.
149 * Otherwise, the receiver MUST silently discard the packet
150 * and take no further action. An endpoint MUST ignore the
151 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152 *
153 * Inputs
154 * (endpoint, asoc, chunk)
155 *
156 * Outputs
157 * (asoc, reply_msg, msg_up, timers, counters)
158 *
159 * The return value is the disposition of the chunk.
160 */
161sctp_disposition_t sctp_sf_do_4_C(const struct sctp_endpoint *ep,
162 const struct sctp_association *asoc,
163 const sctp_subtype_t type,
164 void *arg,
165 sctp_cmd_seq_t *commands)
166{
167 struct sctp_chunk *chunk = arg;
168 struct sctp_ulpevent *ev;
169
170 /* RFC 2960 6.10 Bundling
171 *
172 * An endpoint MUST NOT bundle INIT, INIT ACK or
173 * SHUTDOWN COMPLETE with any other chunks.
174 */
175 if (!chunk->singleton)
176 return SCTP_DISPOSITION_VIOLATION;
177
178 if (!sctp_vtag_verify_either(chunk, asoc))
179 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
180
181 /* RFC 2960 10.2 SCTP-to-ULP
182 *
183 * H) SHUTDOWN COMPLETE notification
184 *
185 * When SCTP completes the shutdown procedures (section 9.2) this
186 * notification is passed to the upper layer.
187 */
188 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
189 0, 0, 0, GFP_ATOMIC);
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700190 if (ev)
191 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
192 SCTP_ULPEVENT(ev));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193
194 /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint
195 * will verify that it is in SHUTDOWN-ACK-SENT state, if it is
196 * not the chunk should be discarded. If the endpoint is in
197 * the SHUTDOWN-ACK-SENT state the endpoint should stop the
198 * T2-shutdown timer and remove all knowledge of the
199 * association (and thus the association enters the CLOSED
200 * state).
201 */
202 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
203 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
204
205 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
206 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
207
208 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
209 SCTP_STATE(SCTP_STATE_CLOSED));
210
211 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
212 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
213
214 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
215
216 return SCTP_DISPOSITION_DELETE_TCB;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217}
218
219/*
220 * Respond to a normal INIT chunk.
221 * We are the side that is being asked for an association.
222 *
223 * Section: 5.1 Normal Establishment of an Association, B
224 * B) "Z" shall respond immediately with an INIT ACK chunk. The
225 * destination IP address of the INIT ACK MUST be set to the source
226 * IP address of the INIT to which this INIT ACK is responding. In
227 * the response, besides filling in other parameters, "Z" must set the
228 * Verification Tag field to Tag_A, and also provide its own
229 * Verification Tag (Tag_Z) in the Initiate Tag field.
230 *
231 * Verification Tag: Must be 0.
232 *
233 * Inputs
234 * (endpoint, asoc, chunk)
235 *
236 * Outputs
237 * (asoc, reply_msg, msg_up, timers, counters)
238 *
239 * The return value is the disposition of the chunk.
240 */
241sctp_disposition_t sctp_sf_do_5_1B_init(const struct sctp_endpoint *ep,
242 const struct sctp_association *asoc,
243 const sctp_subtype_t type,
244 void *arg,
245 sctp_cmd_seq_t *commands)
246{
247 struct sctp_chunk *chunk = arg;
248 struct sctp_chunk *repl;
249 struct sctp_association *new_asoc;
250 struct sctp_chunk *err_chunk;
251 struct sctp_packet *packet;
252 sctp_unrecognized_param_t *unk_param;
253 struct sock *sk;
254 int len;
255
256 /* 6.10 Bundling
257 * An endpoint MUST NOT bundle INIT, INIT ACK or
258 * SHUTDOWN COMPLETE with any other chunks.
259 *
260 * IG Section 2.11.2
261 * Furthermore, we require that the receiver of an INIT chunk MUST
262 * enforce these rules by silently discarding an arriving packet
263 * with an INIT chunk that is bundled with other chunks.
264 */
265 if (!chunk->singleton)
266 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
267
268 /* If the packet is an OOTB packet which is temporarily on the
269 * control endpoint, respond with an ABORT.
270 */
271 if (ep == sctp_sk((sctp_get_ctl_sock()))->ep)
272 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
273
274 sk = ep->base.sk;
275 /* If the endpoint is not listening or if the number of associations
276 * on the TCP-style socket exceed the max backlog, respond with an
277 * ABORT.
278 */
279 if (!sctp_sstate(sk, LISTENING) ||
280 (sctp_style(sk, TCP) &&
281 sk_acceptq_is_full(sk)))
282 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
283
284 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
285 * Tag.
286 */
287 if (chunk->sctp_hdr->vtag != 0)
288 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
289
290 /* Make sure that the INIT chunk has a valid length.
291 * Normally, this would cause an ABORT with a Protocol Violation
292 * error, but since we don't have an association, we'll
293 * just discard the packet.
294 */
295 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
296 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
297
298 /* Verify the INIT chunk before processing it. */
299 err_chunk = NULL;
300 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
301 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
302 &err_chunk)) {
303 /* This chunk contains fatal error. It is to be discarded.
304 * Send an ABORT, with causes if there is any.
305 */
306 if (err_chunk) {
307 packet = sctp_abort_pkt_new(ep, asoc, arg,
308 (__u8 *)(err_chunk->chunk_hdr) +
309 sizeof(sctp_chunkhdr_t),
310 ntohs(err_chunk->chunk_hdr->length) -
311 sizeof(sctp_chunkhdr_t));
312
313 sctp_chunk_free(err_chunk);
314
315 if (packet) {
316 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
317 SCTP_PACKET(packet));
318 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
319 return SCTP_DISPOSITION_CONSUME;
320 } else {
321 return SCTP_DISPOSITION_NOMEM;
322 }
323 } else {
324 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg,
325 commands);
326 }
327 }
328
329 /* Grab the INIT header. */
330 chunk->subh.init_hdr = (sctp_inithdr_t *)chunk->skb->data;
331
332 /* Tag the variable length parameters. */
333 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
334
335 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
336 if (!new_asoc)
337 goto nomem;
338
339 /* The call, sctp_process_init(), can fail on memory allocation. */
340 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
341 sctp_source(chunk),
342 (sctp_init_chunk_t *)chunk->chunk_hdr,
343 GFP_ATOMIC))
344 goto nomem_init;
345
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
347
348 /* If there are errors need to be reported for unknown parameters,
349 * make sure to reserve enough room in the INIT ACK for them.
350 */
351 len = 0;
352 if (err_chunk)
353 len = ntohs(err_chunk->chunk_hdr->length) -
354 sizeof(sctp_chunkhdr_t);
355
356 if (sctp_assoc_set_bind_addr_from_ep(new_asoc, GFP_ATOMIC) < 0)
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700357 goto nomem_init;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700358
359 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
360 if (!repl)
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700361 goto nomem_init;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362
363 /* If there are errors need to be reported for unknown parameters,
364 * include them in the outgoing INIT ACK as "Unrecognized parameter"
365 * parameter.
366 */
367 if (err_chunk) {
368 /* Get the "Unrecognized parameter" parameter(s) out of the
369 * ERROR chunk generated by sctp_verify_init(). Since the
370 * error cause code for "unknown parameter" and the
371 * "Unrecognized parameter" type is the same, we can
372 * construct the parameters in INIT ACK by copying the
373 * ERROR causes over.
374 */
375 unk_param = (sctp_unrecognized_param_t *)
376 ((__u8 *)(err_chunk->chunk_hdr) +
377 sizeof(sctp_chunkhdr_t));
378 /* Replace the cause code with the "Unrecognized parameter"
379 * parameter type.
380 */
381 sctp_addto_chunk(repl, len, unk_param);
382 sctp_chunk_free(err_chunk);
383 }
384
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700385 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
386
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
388
389 /*
390 * Note: After sending out INIT ACK with the State Cookie parameter,
391 * "Z" MUST NOT allocate any resources, nor keep any states for the
392 * new association. Otherwise, "Z" will be vulnerable to resource
393 * attacks.
394 */
395 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
396
397 return SCTP_DISPOSITION_DELETE_TCB;
398
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399nomem_init:
400 sctp_association_free(new_asoc);
401nomem:
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700402 if (err_chunk)
403 sctp_chunk_free(err_chunk);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404 return SCTP_DISPOSITION_NOMEM;
405}
406
407/*
408 * Respond to a normal INIT ACK chunk.
409 * We are the side that is initiating the association.
410 *
411 * Section: 5.1 Normal Establishment of an Association, C
412 * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init
413 * timer and leave COOKIE-WAIT state. "A" shall then send the State
414 * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start
415 * the T1-cookie timer, and enter the COOKIE-ECHOED state.
416 *
417 * Note: The COOKIE ECHO chunk can be bundled with any pending outbound
418 * DATA chunks, but it MUST be the first chunk in the packet and
419 * until the COOKIE ACK is returned the sender MUST NOT send any
420 * other packets to the peer.
421 *
422 * Verification Tag: 3.3.3
423 * If the value of the Initiate Tag in a received INIT ACK chunk is
424 * found to be 0, the receiver MUST treat it as an error and close the
425 * association by transmitting an ABORT.
426 *
427 * Inputs
428 * (endpoint, asoc, chunk)
429 *
430 * Outputs
431 * (asoc, reply_msg, msg_up, timers, counters)
432 *
433 * The return value is the disposition of the chunk.
434 */
435sctp_disposition_t sctp_sf_do_5_1C_ack(const struct sctp_endpoint *ep,
436 const struct sctp_association *asoc,
437 const sctp_subtype_t type,
438 void *arg,
439 sctp_cmd_seq_t *commands)
440{
441 struct sctp_chunk *chunk = arg;
442 sctp_init_chunk_t *initchunk;
443 __u32 init_tag;
444 struct sctp_chunk *err_chunk;
445 struct sctp_packet *packet;
Al Virof94c0192006-11-20 17:00:25 -0800446 sctp_error_t error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447
448 if (!sctp_vtag_verify(chunk, asoc))
449 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
450
451 /* Make sure that the INIT-ACK chunk has a valid length */
452 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_initack_chunk_t)))
453 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
454 commands);
455 /* 6.10 Bundling
456 * An endpoint MUST NOT bundle INIT, INIT ACK or
457 * SHUTDOWN COMPLETE with any other chunks.
458 */
459 if (!chunk->singleton)
460 return SCTP_DISPOSITION_VIOLATION;
461
462 /* Grab the INIT header. */
463 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
464
465 init_tag = ntohl(chunk->subh.init_hdr->init_tag);
466
467 /* Verification Tag: 3.3.3
468 * If the value of the Initiate Tag in a received INIT ACK
469 * chunk is found to be 0, the receiver MUST treat it as an
470 * error and close the association by transmitting an ABORT.
471 */
472 if (!init_tag) {
473 struct sctp_chunk *reply = sctp_make_abort(asoc, chunk, 0);
474 if (!reply)
475 goto nomem;
476
477 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700478 return sctp_stop_t1_and_abort(commands, SCTP_ERROR_INV_PARAM,
479 ECONNREFUSED, asoc,
480 chunk->transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481 }
482
483 /* Verify the INIT chunk before processing it. */
484 err_chunk = NULL;
485 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
486 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
487 &err_chunk)) {
488
489 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
490
491 /* This chunk contains fatal error. It is to be discarded.
492 * Send an ABORT, with causes if there is any.
493 */
494 if (err_chunk) {
495 packet = sctp_abort_pkt_new(ep, asoc, arg,
496 (__u8 *)(err_chunk->chunk_hdr) +
497 sizeof(sctp_chunkhdr_t),
498 ntohs(err_chunk->chunk_hdr->length) -
499 sizeof(sctp_chunkhdr_t));
500
501 sctp_chunk_free(err_chunk);
502
503 if (packet) {
504 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
505 SCTP_PACKET(packet));
506 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700507 error = SCTP_ERROR_INV_PARAM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508 } else {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700509 error = SCTP_ERROR_NO_RESOURCE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510 }
511 } else {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700512 sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
513 error = SCTP_ERROR_INV_PARAM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514 }
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700515 return sctp_stop_t1_and_abort(commands, error, ECONNREFUSED,
516 asoc, chunk->transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517 }
518
519 /* Tag the variable length parameters. Note that we never
520 * convert the parameters in an INIT chunk.
521 */
522 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
523
524 initchunk = (sctp_init_chunk_t *) chunk->chunk_hdr;
525
526 sctp_add_cmd_sf(commands, SCTP_CMD_PEER_INIT,
527 SCTP_PEER_INIT(initchunk));
528
Frank Filz3f7a87d2005-06-20 13:14:57 -0700529 /* Reset init error count upon receipt of INIT-ACK. */
530 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
531
Linus Torvalds1da177e2005-04-16 15:20:36 -0700532 /* 5.1 C) "A" shall stop the T1-init timer and leave
533 * COOKIE-WAIT state. "A" shall then ... start the T1-cookie
534 * timer, and enter the COOKIE-ECHOED state.
535 */
536 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
537 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
538 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
539 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
540 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
541 SCTP_STATE(SCTP_STATE_COOKIE_ECHOED));
542
543 /* 5.1 C) "A" shall then send the State Cookie received in the
544 * INIT ACK chunk in a COOKIE ECHO chunk, ...
545 */
546 /* If there is any errors to report, send the ERROR chunk generated
547 * for unknown parameters as well.
548 */
549 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_COOKIE_ECHO,
550 SCTP_CHUNK(err_chunk));
551
552 return SCTP_DISPOSITION_CONSUME;
553
554nomem:
555 return SCTP_DISPOSITION_NOMEM;
556}
557
558/*
559 * Respond to a normal COOKIE ECHO chunk.
560 * We are the side that is being asked for an association.
561 *
562 * Section: 5.1 Normal Establishment of an Association, D
563 * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply
564 * with a COOKIE ACK chunk after building a TCB and moving to
565 * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with
566 * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK
567 * chunk MUST be the first chunk in the packet.
568 *
569 * IMPLEMENTATION NOTE: An implementation may choose to send the
570 * Communication Up notification to the SCTP user upon reception
571 * of a valid COOKIE ECHO chunk.
572 *
573 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
574 * D) Rules for packet carrying a COOKIE ECHO
575 *
576 * - When sending a COOKIE ECHO, the endpoint MUST use the value of the
577 * Initial Tag received in the INIT ACK.
578 *
579 * - The receiver of a COOKIE ECHO follows the procedures in Section 5.
580 *
581 * Inputs
582 * (endpoint, asoc, chunk)
583 *
584 * Outputs
585 * (asoc, reply_msg, msg_up, timers, counters)
586 *
587 * The return value is the disposition of the chunk.
588 */
589sctp_disposition_t sctp_sf_do_5_1D_ce(const struct sctp_endpoint *ep,
590 const struct sctp_association *asoc,
591 const sctp_subtype_t type, void *arg,
592 sctp_cmd_seq_t *commands)
593{
594 struct sctp_chunk *chunk = arg;
595 struct sctp_association *new_asoc;
596 sctp_init_chunk_t *peer_init;
597 struct sctp_chunk *repl;
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700598 struct sctp_ulpevent *ev, *ai_ev = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599 int error = 0;
600 struct sctp_chunk *err_chk_p;
601
602 /* If the packet is an OOTB packet which is temporarily on the
603 * control endpoint, respond with an ABORT.
604 */
605 if (ep == sctp_sk((sctp_get_ctl_sock()))->ep)
606 return sctp_sf_ootb(ep, asoc, type, arg, commands);
607
608 /* Make sure that the COOKIE_ECHO chunk has a valid length.
609 * In this case, we check that we have enough for at least a
610 * chunk header. More detailed verification is done
611 * in sctp_unpack_cookie().
612 */
613 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
614 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
615
616 /* "Decode" the chunk. We have no optional parameters so we
617 * are in good shape.
618 */
619 chunk->subh.cookie_hdr =
620 (struct sctp_signed_cookie *)chunk->skb->data;
Sridhar Samudrala62b08082006-05-05 17:04:43 -0700621 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
622 sizeof(sctp_chunkhdr_t)))
623 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700624
625 /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
626 * "Z" will reply with a COOKIE ACK chunk after building a TCB
627 * and moving to the ESTABLISHED state.
628 */
629 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
630 &err_chk_p);
631
632 /* FIXME:
633 * If the re-build failed, what is the proper error path
634 * from here?
635 *
636 * [We should abort the association. --piggy]
637 */
638 if (!new_asoc) {
639 /* FIXME: Several errors are possible. A bad cookie should
640 * be silently discarded, but think about logging it too.
641 */
642 switch (error) {
643 case -SCTP_IERROR_NOMEM:
644 goto nomem;
645
646 case -SCTP_IERROR_STALE_COOKIE:
647 sctp_send_stale_cookie_err(ep, asoc, chunk, commands,
648 err_chk_p);
649 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
650
651 case -SCTP_IERROR_BAD_SIG:
652 default:
653 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
654 };
655 }
656
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700658 /* Delay state machine commands until later.
659 *
660 * Re-build the bind address for the association is done in
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661 * the sctp_unpack_cookie() already.
662 */
663 /* This is a brand-new association, so these are not yet side
664 * effects--it is safe to run them here.
665 */
666 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
667
668 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
Al Viro6a1e5f32006-11-20 17:12:25 -0800669 &chunk->subh.cookie_hdr->c.peer_addr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670 peer_init, GFP_ATOMIC))
671 goto nomem_init;
672
673 repl = sctp_make_cookie_ack(new_asoc, chunk);
674 if (!repl)
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700675 goto nomem_init;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676
677 /* RFC 2960 5.1 Normal Establishment of an Association
678 *
679 * D) IMPLEMENTATION NOTE: An implementation may choose to
680 * send the Communication Up notification to the SCTP user
681 * upon reception of a valid COOKIE ECHO chunk.
682 */
683 ev = sctp_ulpevent_make_assoc_change(new_asoc, 0, SCTP_COMM_UP, 0,
684 new_asoc->c.sinit_num_ostreams,
685 new_asoc->c.sinit_max_instreams,
686 GFP_ATOMIC);
687 if (!ev)
688 goto nomem_ev;
689
Linus Torvalds1da177e2005-04-16 15:20:36 -0700690 /* Sockets API Draft Section 5.3.1.6
691 * When a peer sends a Adaption Layer Indication parameter , SCTP
692 * delivers this notification to inform the application that of the
693 * peers requested adaption layer.
694 */
695 if (new_asoc->peer.adaption_ind) {
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700696 ai_ev = sctp_ulpevent_make_adaption_indication(new_asoc,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700697 GFP_ATOMIC);
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700698 if (!ai_ev)
699 goto nomem_aiev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700700 }
701
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700702 /* Add all the state machine commands now since we've created
703 * everything. This way we don't introduce memory corruptions
704 * during side-effect processing and correclty count established
705 * associations.
706 */
707 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
708 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
709 SCTP_STATE(SCTP_STATE_ESTABLISHED));
710 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
711 SCTP_INC_STATS(SCTP_MIB_PASSIVEESTABS);
712 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
713
714 if (new_asoc->autoclose)
715 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
716 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
717
718 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
719
720 /* This will send the COOKIE ACK */
721 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
722
723 /* Queue the ASSOC_CHANGE event */
724 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
725
726 /* Send up the Adaptation Layer Indication event */
727 if (ai_ev)
728 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
729 SCTP_ULPEVENT(ai_ev));
730
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731 return SCTP_DISPOSITION_CONSUME;
732
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -0700733nomem_aiev:
734 sctp_ulpevent_free(ev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700735nomem_ev:
736 sctp_chunk_free(repl);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700737nomem_init:
738 sctp_association_free(new_asoc);
739nomem:
740 return SCTP_DISPOSITION_NOMEM;
741}
742
743/*
744 * Respond to a normal COOKIE ACK chunk.
745 * We are the side that is being asked for an association.
746 *
747 * RFC 2960 5.1 Normal Establishment of an Association
748 *
749 * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the
750 * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie
751 * timer. It may also notify its ULP about the successful
752 * establishment of the association with a Communication Up
753 * notification (see Section 10).
754 *
755 * Verification Tag:
756 * Inputs
757 * (endpoint, asoc, chunk)
758 *
759 * Outputs
760 * (asoc, reply_msg, msg_up, timers, counters)
761 *
762 * The return value is the disposition of the chunk.
763 */
764sctp_disposition_t sctp_sf_do_5_1E_ca(const struct sctp_endpoint *ep,
765 const struct sctp_association *asoc,
766 const sctp_subtype_t type, void *arg,
767 sctp_cmd_seq_t *commands)
768{
769 struct sctp_chunk *chunk = arg;
770 struct sctp_ulpevent *ev;
771
772 if (!sctp_vtag_verify(chunk, asoc))
773 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
774
775 /* Verify that the chunk length for the COOKIE-ACK is OK.
776 * If we don't do this, any bundled chunks may be junked.
777 */
778 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
779 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
780 commands);
781
782 /* Reset init error count upon receipt of COOKIE-ACK,
783 * to avoid problems with the managemement of this
784 * counter in stale cookie situations when a transition back
785 * from the COOKIE-ECHOED state to the COOKIE-WAIT
786 * state is performed.
787 */
Frank Filz3f7a87d2005-06-20 13:14:57 -0700788 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
Linus Torvalds1da177e2005-04-16 15:20:36 -0700789
790 /* RFC 2960 5.1 Normal Establishment of an Association
791 *
792 * E) Upon reception of the COOKIE ACK, endpoint "A" will move
793 * from the COOKIE-ECHOED state to the ESTABLISHED state,
794 * stopping the T1-cookie timer.
795 */
796 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
797 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
798 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
799 SCTP_STATE(SCTP_STATE_ESTABLISHED));
800 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
801 SCTP_INC_STATS(SCTP_MIB_ACTIVEESTABS);
802 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
803 if (asoc->autoclose)
804 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
805 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
806 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
807
808 /* It may also notify its ULP about the successful
809 * establishment of the association with a Communication Up
810 * notification (see Section 10).
811 */
812 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP,
813 0, asoc->c.sinit_num_ostreams,
814 asoc->c.sinit_max_instreams,
815 GFP_ATOMIC);
816
817 if (!ev)
818 goto nomem;
819
820 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
821
822 /* Sockets API Draft Section 5.3.1.6
823 * When a peer sends a Adaption Layer Indication parameter , SCTP
824 * delivers this notification to inform the application that of the
825 * peers requested adaption layer.
826 */
827 if (asoc->peer.adaption_ind) {
828 ev = sctp_ulpevent_make_adaption_indication(asoc, GFP_ATOMIC);
829 if (!ev)
830 goto nomem;
831
832 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
833 SCTP_ULPEVENT(ev));
834 }
835
836 return SCTP_DISPOSITION_CONSUME;
837nomem:
838 return SCTP_DISPOSITION_NOMEM;
839}
840
841/* Generate and sendout a heartbeat packet. */
842static sctp_disposition_t sctp_sf_heartbeat(const struct sctp_endpoint *ep,
843 const struct sctp_association *asoc,
844 const sctp_subtype_t type,
845 void *arg,
846 sctp_cmd_seq_t *commands)
847{
848 struct sctp_transport *transport = (struct sctp_transport *) arg;
849 struct sctp_chunk *reply;
850 sctp_sender_hb_info_t hbinfo;
851 size_t paylen = 0;
852
853 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO;
854 hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t));
Al Viro63de08f2006-11-20 17:07:25 -0800855 hbinfo.daddr = transport->ipaddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700856 hbinfo.sent_at = jiffies;
Sridhar Samudralaad8fec12006-07-21 14:48:50 -0700857 hbinfo.hb_nonce = transport->hb_nonce;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700858
859 /* Send a heartbeat to our peer. */
860 paylen = sizeof(sctp_sender_hb_info_t);
861 reply = sctp_make_heartbeat(asoc, transport, &hbinfo, paylen);
862 if (!reply)
863 return SCTP_DISPOSITION_NOMEM;
864
865 /* Set rto_pending indicating that an RTT measurement
866 * is started with this heartbeat chunk.
867 */
868 sctp_add_cmd_sf(commands, SCTP_CMD_RTO_PENDING,
869 SCTP_TRANSPORT(transport));
870
871 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
872 return SCTP_DISPOSITION_CONSUME;
873}
874
875/* Generate a HEARTBEAT packet on the given transport. */
876sctp_disposition_t sctp_sf_sendbeat_8_3(const struct sctp_endpoint *ep,
877 const struct sctp_association *asoc,
878 const sctp_subtype_t type,
879 void *arg,
880 sctp_cmd_seq_t *commands)
881{
882 struct sctp_transport *transport = (struct sctp_transport *) arg;
883
Vlad Yaseviche2c2fc22006-01-30 16:00:40 -0800884 if (asoc->overall_error_count >= asoc->max_retrans) {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700885 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
886 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700887 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
888 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -0800889 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700890 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
891 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
892 return SCTP_DISPOSITION_DELETE_TCB;
893 }
894
895 /* Section 3.3.5.
896 * The Sender-specific Heartbeat Info field should normally include
897 * information about the sender's current time when this HEARTBEAT
898 * chunk is sent and the destination transport address to which this
899 * HEARTBEAT is sent (see Section 8.3).
900 */
901
Frank Filz52ccb8e2005-12-22 11:36:46 -0800902 if (transport->param_flags & SPP_HB_ENABLE) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700903 if (SCTP_DISPOSITION_NOMEM ==
904 sctp_sf_heartbeat(ep, asoc, type, arg,
905 commands))
906 return SCTP_DISPOSITION_NOMEM;
907 /* Set transport error counter and association error counter
908 * when sending heartbeat.
909 */
910 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_RESET,
911 SCTP_TRANSPORT(transport));
912 }
913 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMER_UPDATE,
914 SCTP_TRANSPORT(transport));
915
916 return SCTP_DISPOSITION_CONSUME;
917}
918
919/*
920 * Process an heartbeat request.
921 *
922 * Section: 8.3 Path Heartbeat
923 * The receiver of the HEARTBEAT should immediately respond with a
924 * HEARTBEAT ACK that contains the Heartbeat Information field copied
925 * from the received HEARTBEAT chunk.
926 *
927 * Verification Tag: 8.5 Verification Tag [Normal verification]
928 * When receiving an SCTP packet, the endpoint MUST ensure that the
929 * value in the Verification Tag field of the received SCTP packet
930 * matches its own Tag. If the received Verification Tag value does not
931 * match the receiver's own tag value, the receiver shall silently
932 * discard the packet and shall not process it any further except for
933 * those cases listed in Section 8.5.1 below.
934 *
935 * Inputs
936 * (endpoint, asoc, chunk)
937 *
938 * Outputs
939 * (asoc, reply_msg, msg_up, timers, counters)
940 *
941 * The return value is the disposition of the chunk.
942 */
943sctp_disposition_t sctp_sf_beat_8_3(const struct sctp_endpoint *ep,
944 const struct sctp_association *asoc,
945 const sctp_subtype_t type,
946 void *arg,
947 sctp_cmd_seq_t *commands)
948{
949 struct sctp_chunk *chunk = arg;
950 struct sctp_chunk *reply;
951 size_t paylen = 0;
952
953 if (!sctp_vtag_verify(chunk, asoc))
954 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
955
956 /* Make sure that the HEARTBEAT chunk has a valid length. */
957 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t)))
958 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
959 commands);
960
961 /* 8.3 The receiver of the HEARTBEAT should immediately
962 * respond with a HEARTBEAT ACK that contains the Heartbeat
963 * Information field copied from the received HEARTBEAT chunk.
964 */
965 chunk->subh.hb_hdr = (sctp_heartbeathdr_t *) chunk->skb->data;
966 paylen = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
Sridhar Samudrala62b08082006-05-05 17:04:43 -0700967 if (!pskb_pull(chunk->skb, paylen))
968 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700969
970 reply = sctp_make_heartbeat_ack(asoc, chunk,
971 chunk->subh.hb_hdr, paylen);
972 if (!reply)
973 goto nomem;
974
975 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
976 return SCTP_DISPOSITION_CONSUME;
977
978nomem:
979 return SCTP_DISPOSITION_NOMEM;
980}
981
982/*
983 * Process the returning HEARTBEAT ACK.
984 *
985 * Section: 8.3 Path Heartbeat
986 * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT
987 * should clear the error counter of the destination transport
988 * address to which the HEARTBEAT was sent, and mark the destination
989 * transport address as active if it is not so marked. The endpoint may
990 * optionally report to the upper layer when an inactive destination
991 * address is marked as active due to the reception of the latest
992 * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also
993 * clear the association overall error count as well (as defined
994 * in section 8.1).
995 *
996 * The receiver of the HEARTBEAT ACK should also perform an RTT
997 * measurement for that destination transport address using the time
998 * value carried in the HEARTBEAT ACK chunk.
999 *
1000 * Verification Tag: 8.5 Verification Tag [Normal verification]
1001 *
1002 * Inputs
1003 * (endpoint, asoc, chunk)
1004 *
1005 * Outputs
1006 * (asoc, reply_msg, msg_up, timers, counters)
1007 *
1008 * The return value is the disposition of the chunk.
1009 */
1010sctp_disposition_t sctp_sf_backbeat_8_3(const struct sctp_endpoint *ep,
1011 const struct sctp_association *asoc,
1012 const sctp_subtype_t type,
1013 void *arg,
1014 sctp_cmd_seq_t *commands)
1015{
1016 struct sctp_chunk *chunk = arg;
1017 union sctp_addr from_addr;
1018 struct sctp_transport *link;
1019 sctp_sender_hb_info_t *hbinfo;
1020 unsigned long max_interval;
1021
1022 if (!sctp_vtag_verify(chunk, asoc))
1023 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1024
1025 /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */
1026 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t)))
1027 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1028 commands);
1029
1030 hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
Vladislav Yasevicha6012662006-05-19 14:25:53 -07001031 /* Make sure that the length of the parameter is what we expect */
1032 if (ntohs(hbinfo->param_hdr.length) !=
1033 sizeof(sctp_sender_hb_info_t)) {
1034 return SCTP_DISPOSITION_DISCARD;
1035 }
1036
Linus Torvalds1da177e2005-04-16 15:20:36 -07001037 from_addr = hbinfo->daddr;
Al Viro63de08f2006-11-20 17:07:25 -08001038 link = sctp_assoc_lookup_paddr(asoc, &from_addr);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001039
1040 /* This should never happen, but lets log it if so. */
Frank Filz3f7a87d2005-06-20 13:14:57 -07001041 if (unlikely(!link)) {
1042 if (from_addr.sa.sa_family == AF_INET6) {
1043 printk(KERN_WARNING
1044 "%s association %p could not find address "
Joe Perches46b86a22006-01-13 14:29:07 -08001045 NIP6_FMT "\n",
Frank Filz3f7a87d2005-06-20 13:14:57 -07001046 __FUNCTION__,
1047 asoc,
1048 NIP6(from_addr.v6.sin6_addr));
1049 } else {
1050 printk(KERN_WARNING
1051 "%s association %p could not find address "
Joe Perches46b86a22006-01-13 14:29:07 -08001052 NIPQUAD_FMT "\n",
Frank Filz3f7a87d2005-06-20 13:14:57 -07001053 __FUNCTION__,
1054 asoc,
1055 NIPQUAD(from_addr.v4.sin_addr.s_addr));
1056 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001057 return SCTP_DISPOSITION_DISCARD;
1058 }
1059
Sridhar Samudralaad8fec12006-07-21 14:48:50 -07001060 /* Validate the 64-bit random nonce. */
1061 if (hbinfo->hb_nonce != link->hb_nonce)
1062 return SCTP_DISPOSITION_DISCARD;
1063
Frank Filz52ccb8e2005-12-22 11:36:46 -08001064 max_interval = link->hbinterval + link->rto;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001065
1066 /* Check if the timestamp looks valid. */
1067 if (time_after(hbinfo->sent_at, jiffies) ||
1068 time_after(jiffies, hbinfo->sent_at + max_interval)) {
1069 SCTP_DEBUG_PRINTK("%s: HEARTBEAT ACK with invalid timestamp"
1070 "received for transport: %p\n",
1071 __FUNCTION__, link);
1072 return SCTP_DISPOSITION_DISCARD;
1073 }
1074
1075 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of
1076 * the HEARTBEAT should clear the error counter of the
1077 * destination transport address to which the HEARTBEAT was
1078 * sent and mark the destination transport address as active if
1079 * it is not so marked.
1080 */
1081 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_ON, SCTP_TRANSPORT(link));
1082
1083 return SCTP_DISPOSITION_CONSUME;
1084}
1085
1086/* Helper function to send out an abort for the restart
1087 * condition.
1088 */
1089static int sctp_sf_send_restart_abort(union sctp_addr *ssa,
1090 struct sctp_chunk *init,
1091 sctp_cmd_seq_t *commands)
1092{
1093 int len;
1094 struct sctp_packet *pkt;
1095 union sctp_addr_param *addrparm;
1096 struct sctp_errhdr *errhdr;
1097 struct sctp_endpoint *ep;
1098 char buffer[sizeof(struct sctp_errhdr)+sizeof(union sctp_addr_param)];
1099 struct sctp_af *af = sctp_get_af_specific(ssa->v4.sin_family);
1100
1101 /* Build the error on the stack. We are way to malloc crazy
1102 * throughout the code today.
1103 */
1104 errhdr = (struct sctp_errhdr *)buffer;
1105 addrparm = (union sctp_addr_param *)errhdr->variable;
1106
1107 /* Copy into a parm format. */
1108 len = af->to_addr_param(ssa, addrparm);
1109 len += sizeof(sctp_errhdr_t);
1110
1111 errhdr->cause = SCTP_ERROR_RESTART;
1112 errhdr->length = htons(len);
1113
1114 /* Assign to the control socket. */
1115 ep = sctp_sk((sctp_get_ctl_sock()))->ep;
1116
1117 /* Association is NULL since this may be a restart attack and we
1118 * want to send back the attacker's vtag.
1119 */
1120 pkt = sctp_abort_pkt_new(ep, NULL, init, errhdr, len);
1121
1122 if (!pkt)
1123 goto out;
1124 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, SCTP_PACKET(pkt));
1125
1126 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
1127
1128 /* Discard the rest of the inbound packet. */
1129 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
1130
1131out:
1132 /* Even if there is no memory, treat as a failure so
1133 * the packet will get dropped.
1134 */
1135 return 0;
1136}
1137
1138/* A restart is occurring, check to make sure no new addresses
1139 * are being added as we may be under a takeover attack.
1140 */
1141static int sctp_sf_check_restart_addrs(const struct sctp_association *new_asoc,
1142 const struct sctp_association *asoc,
1143 struct sctp_chunk *init,
1144 sctp_cmd_seq_t *commands)
1145{
1146 struct sctp_transport *new_addr, *addr;
1147 struct list_head *pos, *pos2;
1148 int found;
1149
1150 /* Implementor's Guide - Sectin 5.2.2
1151 * ...
1152 * Before responding the endpoint MUST check to see if the
1153 * unexpected INIT adds new addresses to the association. If new
1154 * addresses are added to the association, the endpoint MUST respond
1155 * with an ABORT..
1156 */
1157
1158 /* Search through all current addresses and make sure
1159 * we aren't adding any new ones.
1160 */
1161 new_addr = NULL;
1162 found = 0;
1163
1164 list_for_each(pos, &new_asoc->peer.transport_addr_list) {
1165 new_addr = list_entry(pos, struct sctp_transport, transports);
1166 found = 0;
1167 list_for_each(pos2, &asoc->peer.transport_addr_list) {
1168 addr = list_entry(pos2, struct sctp_transport,
1169 transports);
Al Viro5f242a12006-11-20 17:05:23 -08001170 if (sctp_cmp_addr_exact(&new_addr->ipaddr,
1171 &addr->ipaddr)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001172 found = 1;
1173 break;
1174 }
1175 }
1176 if (!found)
1177 break;
1178 }
1179
1180 /* If a new address was added, ABORT the sender. */
1181 if (!found && new_addr) {
Al Viro7dd8a582006-11-20 17:23:25 -08001182 sctp_sf_send_restart_abort(&new_addr->ipaddr, init, commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001183 }
1184
1185 /* Return success if all addresses were found. */
1186 return found;
1187}
1188
1189/* Populate the verification/tie tags based on overlapping INIT
1190 * scenario.
1191 *
1192 * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state.
1193 */
1194static void sctp_tietags_populate(struct sctp_association *new_asoc,
1195 const struct sctp_association *asoc)
1196{
1197 switch (asoc->state) {
1198
1199 /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */
1200
1201 case SCTP_STATE_COOKIE_WAIT:
1202 new_asoc->c.my_vtag = asoc->c.my_vtag;
1203 new_asoc->c.my_ttag = asoc->c.my_vtag;
1204 new_asoc->c.peer_ttag = 0;
1205 break;
1206
1207 case SCTP_STATE_COOKIE_ECHOED:
1208 new_asoc->c.my_vtag = asoc->c.my_vtag;
1209 new_asoc->c.my_ttag = asoc->c.my_vtag;
1210 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1211 break;
1212
1213 /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED,
1214 * COOKIE-WAIT and SHUTDOWN-ACK-SENT
1215 */
1216 default:
1217 new_asoc->c.my_ttag = asoc->c.my_vtag;
1218 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1219 break;
1220 };
1221
1222 /* Other parameters for the endpoint SHOULD be copied from the
1223 * existing parameters of the association (e.g. number of
1224 * outbound streams) into the INIT ACK and cookie.
1225 */
1226 new_asoc->rwnd = asoc->rwnd;
1227 new_asoc->c.sinit_num_ostreams = asoc->c.sinit_num_ostreams;
1228 new_asoc->c.sinit_max_instreams = asoc->c.sinit_max_instreams;
1229 new_asoc->c.initial_tsn = asoc->c.initial_tsn;
1230}
1231
1232/*
1233 * Compare vtag/tietag values to determine unexpected COOKIE-ECHO
1234 * handling action.
1235 *
1236 * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists.
1237 *
1238 * Returns value representing action to be taken. These action values
1239 * correspond to Action/Description values in RFC 2960, Table 2.
1240 */
1241static char sctp_tietags_compare(struct sctp_association *new_asoc,
1242 const struct sctp_association *asoc)
1243{
1244 /* In this case, the peer may have restarted. */
1245 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1246 (asoc->c.peer_vtag != new_asoc->c.peer_vtag) &&
1247 (asoc->c.my_vtag == new_asoc->c.my_ttag) &&
1248 (asoc->c.peer_vtag == new_asoc->c.peer_ttag))
1249 return 'A';
1250
1251 /* Collision case B. */
1252 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1253 ((asoc->c.peer_vtag != new_asoc->c.peer_vtag) ||
1254 (0 == asoc->c.peer_vtag))) {
1255 return 'B';
1256 }
1257
1258 /* Collision case D. */
1259 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1260 (asoc->c.peer_vtag == new_asoc->c.peer_vtag))
1261 return 'D';
1262
1263 /* Collision case C. */
1264 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1265 (asoc->c.peer_vtag == new_asoc->c.peer_vtag) &&
1266 (0 == new_asoc->c.my_ttag) &&
1267 (0 == new_asoc->c.peer_ttag))
1268 return 'C';
1269
1270 /* No match to any of the special cases; discard this packet. */
1271 return 'E';
1272}
1273
1274/* Common helper routine for both duplicate and simulataneous INIT
1275 * chunk handling.
1276 */
1277static sctp_disposition_t sctp_sf_do_unexpected_init(
1278 const struct sctp_endpoint *ep,
1279 const struct sctp_association *asoc,
1280 const sctp_subtype_t type,
1281 void *arg, sctp_cmd_seq_t *commands)
1282{
1283 sctp_disposition_t retval;
1284 struct sctp_chunk *chunk = arg;
1285 struct sctp_chunk *repl;
1286 struct sctp_association *new_asoc;
1287 struct sctp_chunk *err_chunk;
1288 struct sctp_packet *packet;
1289 sctp_unrecognized_param_t *unk_param;
1290 int len;
1291
1292 /* 6.10 Bundling
1293 * An endpoint MUST NOT bundle INIT, INIT ACK or
1294 * SHUTDOWN COMPLETE with any other chunks.
1295 *
1296 * IG Section 2.11.2
1297 * Furthermore, we require that the receiver of an INIT chunk MUST
1298 * enforce these rules by silently discarding an arriving packet
1299 * with an INIT chunk that is bundled with other chunks.
1300 */
1301 if (!chunk->singleton)
1302 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1303
1304 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
1305 * Tag.
1306 */
1307 if (chunk->sctp_hdr->vtag != 0)
1308 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
1309
1310 /* Make sure that the INIT chunk has a valid length.
1311 * In this case, we generate a protocol violation since we have
1312 * an association established.
1313 */
1314 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
1315 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1316 commands);
1317 /* Grab the INIT header. */
1318 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
1319
1320 /* Tag the variable length parameters. */
1321 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
1322
1323 /* Verify the INIT chunk before processing it. */
1324 err_chunk = NULL;
1325 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
1326 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
1327 &err_chunk)) {
1328 /* This chunk contains fatal error. It is to be discarded.
1329 * Send an ABORT, with causes if there is any.
1330 */
1331 if (err_chunk) {
1332 packet = sctp_abort_pkt_new(ep, asoc, arg,
1333 (__u8 *)(err_chunk->chunk_hdr) +
1334 sizeof(sctp_chunkhdr_t),
1335 ntohs(err_chunk->chunk_hdr->length) -
1336 sizeof(sctp_chunkhdr_t));
1337
1338 if (packet) {
1339 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
1340 SCTP_PACKET(packet));
1341 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
1342 retval = SCTP_DISPOSITION_CONSUME;
1343 } else {
1344 retval = SCTP_DISPOSITION_NOMEM;
1345 }
1346 goto cleanup;
1347 } else {
1348 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg,
1349 commands);
1350 }
1351 }
1352
1353 /*
1354 * Other parameters for the endpoint SHOULD be copied from the
1355 * existing parameters of the association (e.g. number of
1356 * outbound streams) into the INIT ACK and cookie.
1357 * FIXME: We are copying parameters from the endpoint not the
1358 * association.
1359 */
1360 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
1361 if (!new_asoc)
1362 goto nomem;
1363
1364 /* In the outbound INIT ACK the endpoint MUST copy its current
1365 * Verification Tag and Peers Verification tag into a reserved
1366 * place (local tie-tag and per tie-tag) within the state cookie.
1367 */
1368 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
1369 sctp_source(chunk),
1370 (sctp_init_chunk_t *)chunk->chunk_hdr,
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001371 GFP_ATOMIC))
1372 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001373
1374 /* Make sure no new addresses are being added during the
1375 * restart. Do not do this check for COOKIE-WAIT state,
1376 * since there are no peer addresses to check against.
1377 * Upon return an ABORT will have been sent if needed.
1378 */
1379 if (!sctp_state(asoc, COOKIE_WAIT)) {
1380 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk,
1381 commands)) {
1382 retval = SCTP_DISPOSITION_CONSUME;
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001383 goto nomem_retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001384 }
1385 }
1386
1387 sctp_tietags_populate(new_asoc, asoc);
1388
1389 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
1390
1391 /* If there are errors need to be reported for unknown parameters,
1392 * make sure to reserve enough room in the INIT ACK for them.
1393 */
1394 len = 0;
1395 if (err_chunk) {
1396 len = ntohs(err_chunk->chunk_hdr->length) -
1397 sizeof(sctp_chunkhdr_t);
1398 }
1399
1400 if (sctp_assoc_set_bind_addr_from_ep(new_asoc, GFP_ATOMIC) < 0)
1401 goto nomem;
1402
1403 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
1404 if (!repl)
1405 goto nomem;
1406
1407 /* If there are errors need to be reported for unknown parameters,
1408 * include them in the outgoing INIT ACK as "Unrecognized parameter"
1409 * parameter.
1410 */
1411 if (err_chunk) {
1412 /* Get the "Unrecognized parameter" parameter(s) out of the
1413 * ERROR chunk generated by sctp_verify_init(). Since the
1414 * error cause code for "unknown parameter" and the
1415 * "Unrecognized parameter" type is the same, we can
1416 * construct the parameters in INIT ACK by copying the
1417 * ERROR causes over.
1418 */
1419 unk_param = (sctp_unrecognized_param_t *)
1420 ((__u8 *)(err_chunk->chunk_hdr) +
1421 sizeof(sctp_chunkhdr_t));
1422 /* Replace the cause code with the "Unrecognized parameter"
1423 * parameter type.
1424 */
1425 sctp_addto_chunk(repl, len, unk_param);
1426 }
1427
1428 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
1429 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1430
1431 /*
1432 * Note: After sending out INIT ACK with the State Cookie parameter,
1433 * "Z" MUST NOT allocate any resources for this new association.
1434 * Otherwise, "Z" will be vulnerable to resource attacks.
1435 */
1436 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
1437 retval = SCTP_DISPOSITION_CONSUME;
1438
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001439 return retval;
1440
1441nomem:
1442 retval = SCTP_DISPOSITION_NOMEM;
1443nomem_retval:
1444 if (new_asoc)
1445 sctp_association_free(new_asoc);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001446cleanup:
1447 if (err_chunk)
1448 sctp_chunk_free(err_chunk);
1449 return retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001450}
1451
1452/*
1453 * Handle simultanous INIT.
1454 * This means we started an INIT and then we got an INIT request from
1455 * our peer.
1456 *
1457 * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B)
1458 * This usually indicates an initialization collision, i.e., each
1459 * endpoint is attempting, at about the same time, to establish an
1460 * association with the other endpoint.
1461 *
1462 * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an
1463 * endpoint MUST respond with an INIT ACK using the same parameters it
1464 * sent in its original INIT chunk (including its Verification Tag,
1465 * unchanged). These original parameters are combined with those from the
1466 * newly received INIT chunk. The endpoint shall also generate a State
1467 * Cookie with the INIT ACK. The endpoint uses the parameters sent in its
1468 * INIT to calculate the State Cookie.
1469 *
1470 * After that, the endpoint MUST NOT change its state, the T1-init
1471 * timer shall be left running and the corresponding TCB MUST NOT be
1472 * destroyed. The normal procedures for handling State Cookies when
1473 * a TCB exists will resolve the duplicate INITs to a single association.
1474 *
1475 * For an endpoint that is in the COOKIE-ECHOED state it MUST populate
1476 * its Tie-Tags with the Tag information of itself and its peer (see
1477 * section 5.2.2 for a description of the Tie-Tags).
1478 *
1479 * Verification Tag: Not explicit, but an INIT can not have a valid
1480 * verification tag, so we skip the check.
1481 *
1482 * Inputs
1483 * (endpoint, asoc, chunk)
1484 *
1485 * Outputs
1486 * (asoc, reply_msg, msg_up, timers, counters)
1487 *
1488 * The return value is the disposition of the chunk.
1489 */
1490sctp_disposition_t sctp_sf_do_5_2_1_siminit(const struct sctp_endpoint *ep,
1491 const struct sctp_association *asoc,
1492 const sctp_subtype_t type,
1493 void *arg,
1494 sctp_cmd_seq_t *commands)
1495{
1496 /* Call helper to do the real work for both simulataneous and
1497 * duplicate INIT chunk handling.
1498 */
1499 return sctp_sf_do_unexpected_init(ep, asoc, type, arg, commands);
1500}
1501
1502/*
1503 * Handle duplicated INIT messages. These are usually delayed
1504 * restransmissions.
1505 *
1506 * Section: 5.2.2 Unexpected INIT in States Other than CLOSED,
1507 * COOKIE-ECHOED and COOKIE-WAIT
1508 *
1509 * Unless otherwise stated, upon reception of an unexpected INIT for
1510 * this association, the endpoint shall generate an INIT ACK with a
1511 * State Cookie. In the outbound INIT ACK the endpoint MUST copy its
1512 * current Verification Tag and peer's Verification Tag into a reserved
1513 * place within the state cookie. We shall refer to these locations as
1514 * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet
1515 * containing this INIT ACK MUST carry a Verification Tag value equal to
1516 * the Initiation Tag found in the unexpected INIT. And the INIT ACK
1517 * MUST contain a new Initiation Tag (randomly generated see Section
1518 * 5.3.1). Other parameters for the endpoint SHOULD be copied from the
1519 * existing parameters of the association (e.g. number of outbound
1520 * streams) into the INIT ACK and cookie.
1521 *
1522 * After sending out the INIT ACK, the endpoint shall take no further
1523 * actions, i.e., the existing association, including its current state,
1524 * and the corresponding TCB MUST NOT be changed.
1525 *
1526 * Note: Only when a TCB exists and the association is not in a COOKIE-
1527 * WAIT state are the Tie-Tags populated. For a normal association INIT
1528 * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be
1529 * set to 0 (indicating that no previous TCB existed). The INIT ACK and
1530 * State Cookie are populated as specified in section 5.2.1.
1531 *
1532 * Verification Tag: Not specified, but an INIT has no way of knowing
1533 * what the verification tag could be, so we ignore it.
1534 *
1535 * Inputs
1536 * (endpoint, asoc, chunk)
1537 *
1538 * Outputs
1539 * (asoc, reply_msg, msg_up, timers, counters)
1540 *
1541 * The return value is the disposition of the chunk.
1542 */
1543sctp_disposition_t sctp_sf_do_5_2_2_dupinit(const struct sctp_endpoint *ep,
1544 const struct sctp_association *asoc,
1545 const sctp_subtype_t type,
1546 void *arg,
1547 sctp_cmd_seq_t *commands)
1548{
1549 /* Call helper to do the real work for both simulataneous and
1550 * duplicate INIT chunk handling.
1551 */
1552 return sctp_sf_do_unexpected_init(ep, asoc, type, arg, commands);
1553}
1554
1555
1556
1557/* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A')
1558 *
1559 * Section 5.2.4
1560 * A) In this case, the peer may have restarted.
1561 */
1562static sctp_disposition_t sctp_sf_do_dupcook_a(const struct sctp_endpoint *ep,
1563 const struct sctp_association *asoc,
1564 struct sctp_chunk *chunk,
1565 sctp_cmd_seq_t *commands,
1566 struct sctp_association *new_asoc)
1567{
1568 sctp_init_chunk_t *peer_init;
1569 struct sctp_ulpevent *ev;
1570 struct sctp_chunk *repl;
1571 struct sctp_chunk *err;
1572 sctp_disposition_t disposition;
1573
1574 /* new_asoc is a brand-new association, so these are not yet
1575 * side effects--it is safe to run them here.
1576 */
1577 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1578
1579 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
1580 sctp_source(chunk), peer_init,
1581 GFP_ATOMIC))
1582 goto nomem;
1583
1584 /* Make sure no new addresses are being added during the
1585 * restart. Though this is a pretty complicated attack
1586 * since you'd have to get inside the cookie.
1587 */
1588 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk, commands)) {
1589 return SCTP_DISPOSITION_CONSUME;
1590 }
1591
1592 /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes
1593 * the peer has restarted (Action A), it MUST NOT setup a new
1594 * association but instead resend the SHUTDOWN ACK and send an ERROR
1595 * chunk with a "Cookie Received while Shutting Down" error cause to
1596 * its peer.
1597 */
1598 if (sctp_state(asoc, SHUTDOWN_ACK_SENT)) {
1599 disposition = sctp_sf_do_9_2_reshutack(ep, asoc,
1600 SCTP_ST_CHUNK(chunk->chunk_hdr->type),
1601 chunk, commands);
1602 if (SCTP_DISPOSITION_NOMEM == disposition)
1603 goto nomem;
1604
1605 err = sctp_make_op_error(asoc, chunk,
1606 SCTP_ERROR_COOKIE_IN_SHUTDOWN,
1607 NULL, 0);
1608 if (err)
1609 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1610 SCTP_CHUNK(err));
1611
1612 return SCTP_DISPOSITION_CONSUME;
1613 }
1614
1615 /* For now, fail any unsent/unacked data. Consider the optional
1616 * choice of resending of this data.
1617 */
1618 sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_OUTQUEUE, SCTP_NULL());
1619
Linus Torvalds1da177e2005-04-16 15:20:36 -07001620 repl = sctp_make_cookie_ack(new_asoc, chunk);
1621 if (!repl)
1622 goto nomem;
1623
Linus Torvalds1da177e2005-04-16 15:20:36 -07001624 /* Report association restart to upper layer. */
1625 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_RESTART, 0,
1626 new_asoc->c.sinit_num_ostreams,
1627 new_asoc->c.sinit_max_instreams,
1628 GFP_ATOMIC);
1629 if (!ev)
1630 goto nomem_ev;
1631
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001632 /* Update the content of current association. */
1633 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1634 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001635 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
1636 return SCTP_DISPOSITION_CONSUME;
1637
1638nomem_ev:
1639 sctp_chunk_free(repl);
1640nomem:
1641 return SCTP_DISPOSITION_NOMEM;
1642}
1643
1644/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B')
1645 *
1646 * Section 5.2.4
1647 * B) In this case, both sides may be attempting to start an association
1648 * at about the same time but the peer endpoint started its INIT
1649 * after responding to the local endpoint's INIT
1650 */
1651/* This case represents an initialization collision. */
1652static sctp_disposition_t sctp_sf_do_dupcook_b(const struct sctp_endpoint *ep,
1653 const struct sctp_association *asoc,
1654 struct sctp_chunk *chunk,
1655 sctp_cmd_seq_t *commands,
1656 struct sctp_association *new_asoc)
1657{
1658 sctp_init_chunk_t *peer_init;
1659 struct sctp_ulpevent *ev;
1660 struct sctp_chunk *repl;
1661
1662 /* new_asoc is a brand-new association, so these are not yet
1663 * side effects--it is safe to run them here.
1664 */
1665 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1666 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
1667 sctp_source(chunk), peer_init,
1668 GFP_ATOMIC))
1669 goto nomem;
1670
1671 /* Update the content of current association. */
1672 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1673 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1674 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1675 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
1676 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
1677
1678 repl = sctp_make_cookie_ack(new_asoc, chunk);
1679 if (!repl)
1680 goto nomem;
1681
1682 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1683 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
1684
1685 /* RFC 2960 5.1 Normal Establishment of an Association
1686 *
1687 * D) IMPLEMENTATION NOTE: An implementation may choose to
1688 * send the Communication Up notification to the SCTP user
1689 * upon reception of a valid COOKIE ECHO chunk.
1690 */
1691 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP, 0,
1692 new_asoc->c.sinit_num_ostreams,
1693 new_asoc->c.sinit_max_instreams,
1694 GFP_ATOMIC);
1695 if (!ev)
1696 goto nomem_ev;
1697
1698 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
1699
1700 /* Sockets API Draft Section 5.3.1.6
1701 * When a peer sends a Adaption Layer Indication parameter , SCTP
1702 * delivers this notification to inform the application that of the
1703 * peers requested adaption layer.
1704 */
1705 if (asoc->peer.adaption_ind) {
1706 ev = sctp_ulpevent_make_adaption_indication(asoc, GFP_ATOMIC);
1707 if (!ev)
1708 goto nomem_ev;
1709
1710 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1711 SCTP_ULPEVENT(ev));
1712 }
1713
1714 return SCTP_DISPOSITION_CONSUME;
1715
1716nomem_ev:
1717 sctp_chunk_free(repl);
1718nomem:
1719 return SCTP_DISPOSITION_NOMEM;
1720}
1721
1722/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C')
1723 *
1724 * Section 5.2.4
1725 * C) In this case, the local endpoint's cookie has arrived late.
1726 * Before it arrived, the local endpoint sent an INIT and received an
1727 * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag
1728 * but a new tag of its own.
1729 */
1730/* This case represents an initialization collision. */
1731static sctp_disposition_t sctp_sf_do_dupcook_c(const struct sctp_endpoint *ep,
1732 const struct sctp_association *asoc,
1733 struct sctp_chunk *chunk,
1734 sctp_cmd_seq_t *commands,
1735 struct sctp_association *new_asoc)
1736{
1737 /* The cookie should be silently discarded.
1738 * The endpoint SHOULD NOT change states and should leave
1739 * any timers running.
1740 */
1741 return SCTP_DISPOSITION_DISCARD;
1742}
1743
1744/* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D')
1745 *
1746 * Section 5.2.4
1747 *
1748 * D) When both local and remote tags match the endpoint should always
1749 * enter the ESTABLISHED state, if it has not already done so.
1750 */
1751/* This case represents an initialization collision. */
1752static sctp_disposition_t sctp_sf_do_dupcook_d(const struct sctp_endpoint *ep,
1753 const struct sctp_association *asoc,
1754 struct sctp_chunk *chunk,
1755 sctp_cmd_seq_t *commands,
1756 struct sctp_association *new_asoc)
1757{
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001758 struct sctp_ulpevent *ev = NULL, *ai_ev = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001759 struct sctp_chunk *repl;
1760
1761 /* Clarification from Implementor's Guide:
1762 * D) When both local and remote tags match the endpoint should
1763 * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state.
1764 * It should stop any cookie timer that may be running and send
1765 * a COOKIE ACK.
1766 */
1767
1768 /* Don't accidentally move back into established state. */
1769 if (asoc->state < SCTP_STATE_ESTABLISHED) {
1770 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1771 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1772 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1773 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1774 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
1775 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START,
1776 SCTP_NULL());
1777
1778 /* RFC 2960 5.1 Normal Establishment of an Association
1779 *
1780 * D) IMPLEMENTATION NOTE: An implementation may choose
1781 * to send the Communication Up notification to the
1782 * SCTP user upon reception of a valid COOKIE
1783 * ECHO chunk.
1784 */
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001785 ev = sctp_ulpevent_make_assoc_change(asoc, 0,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001786 SCTP_COMM_UP, 0,
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001787 asoc->c.sinit_num_ostreams,
1788 asoc->c.sinit_max_instreams,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001789 GFP_ATOMIC);
1790 if (!ev)
1791 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001792
1793 /* Sockets API Draft Section 5.3.1.6
1794 * When a peer sends a Adaption Layer Indication parameter,
1795 * SCTP delivers this notification to inform the application
1796 * that of the peers requested adaption layer.
1797 */
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001798 if (asoc->peer.adaption_ind) {
1799 ai_ev = sctp_ulpevent_make_adaption_indication(asoc,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001800 GFP_ATOMIC);
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001801 if (!ai_ev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001802 goto nomem;
1803
Linus Torvalds1da177e2005-04-16 15:20:36 -07001804 }
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
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001812 if (ev)
1813 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1814 SCTP_ULPEVENT(ev));
1815 if (ai_ev)
1816 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1817 SCTP_ULPEVENT(ai_ev));
1818
Linus Torvalds1da177e2005-04-16 15:20:36 -07001819 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1820 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
1821
1822 return SCTP_DISPOSITION_CONSUME;
1823
1824nomem:
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07001825 if (ai_ev)
1826 sctp_ulpevent_free(ai_ev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001827 if (ev)
1828 sctp_ulpevent_free(ev);
1829 return SCTP_DISPOSITION_NOMEM;
1830}
1831
1832/*
1833 * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying
1834 * chunk was retransmitted and then delayed in the network.
1835 *
1836 * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists
1837 *
1838 * Verification Tag: None. Do cookie validation.
1839 *
1840 * Inputs
1841 * (endpoint, asoc, chunk)
1842 *
1843 * Outputs
1844 * (asoc, reply_msg, msg_up, timers, counters)
1845 *
1846 * The return value is the disposition of the chunk.
1847 */
1848sctp_disposition_t sctp_sf_do_5_2_4_dupcook(const struct sctp_endpoint *ep,
1849 const struct sctp_association *asoc,
1850 const sctp_subtype_t type,
1851 void *arg,
1852 sctp_cmd_seq_t *commands)
1853{
1854 sctp_disposition_t retval;
1855 struct sctp_chunk *chunk = arg;
1856 struct sctp_association *new_asoc;
1857 int error = 0;
1858 char action;
1859 struct sctp_chunk *err_chk_p;
1860
1861 /* Make sure that the chunk has a valid length from the protocol
1862 * perspective. In this case check to make sure we have at least
1863 * enough for the chunk header. Cookie length verification is
1864 * done later.
1865 */
1866 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
1867 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1868 commands);
1869
1870 /* "Decode" the chunk. We have no optional parameters so we
1871 * are in good shape.
1872 */
1873 chunk->subh.cookie_hdr = (struct sctp_signed_cookie *)chunk->skb->data;
Sridhar Samudrala62b08082006-05-05 17:04:43 -07001874 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
1875 sizeof(sctp_chunkhdr_t)))
1876 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001877
1878 /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
1879 * of a duplicate COOKIE ECHO match the Verification Tags of the
1880 * current association, consider the State Cookie valid even if
1881 * the lifespan is exceeded.
1882 */
1883 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
1884 &err_chk_p);
1885
1886 /* FIXME:
1887 * If the re-build failed, what is the proper error path
1888 * from here?
1889 *
1890 * [We should abort the association. --piggy]
1891 */
1892 if (!new_asoc) {
1893 /* FIXME: Several errors are possible. A bad cookie should
1894 * be silently discarded, but think about logging it too.
1895 */
1896 switch (error) {
1897 case -SCTP_IERROR_NOMEM:
1898 goto nomem;
1899
1900 case -SCTP_IERROR_STALE_COOKIE:
1901 sctp_send_stale_cookie_err(ep, asoc, chunk, commands,
1902 err_chk_p);
1903 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1904 case -SCTP_IERROR_BAD_SIG:
1905 default:
1906 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1907 };
1908 }
1909
1910 /* Compare the tie_tag in cookie with the verification tag of
1911 * current association.
1912 */
1913 action = sctp_tietags_compare(new_asoc, asoc);
1914
1915 switch (action) {
1916 case 'A': /* Association restart. */
1917 retval = sctp_sf_do_dupcook_a(ep, asoc, chunk, commands,
1918 new_asoc);
1919 break;
1920
1921 case 'B': /* Collision case B. */
1922 retval = sctp_sf_do_dupcook_b(ep, asoc, chunk, commands,
1923 new_asoc);
1924 break;
1925
1926 case 'C': /* Collision case C. */
1927 retval = sctp_sf_do_dupcook_c(ep, asoc, chunk, commands,
1928 new_asoc);
1929 break;
1930
1931 case 'D': /* Collision case D. */
1932 retval = sctp_sf_do_dupcook_d(ep, asoc, chunk, commands,
1933 new_asoc);
1934 break;
1935
1936 default: /* Discard packet for all others. */
1937 retval = sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1938 break;
1939 };
1940
1941 /* Delete the tempory new association. */
1942 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
1943 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
1944
1945 return retval;
1946
1947nomem:
1948 return SCTP_DISPOSITION_NOMEM;
1949}
1950
1951/*
1952 * Process an ABORT. (SHUTDOWN-PENDING state)
1953 *
1954 * See sctp_sf_do_9_1_abort().
1955 */
1956sctp_disposition_t sctp_sf_shutdown_pending_abort(
1957 const struct sctp_endpoint *ep,
1958 const struct sctp_association *asoc,
1959 const sctp_subtype_t type,
1960 void *arg,
1961 sctp_cmd_seq_t *commands)
1962{
1963 struct sctp_chunk *chunk = arg;
1964
1965 if (!sctp_vtag_verify_either(chunk, asoc))
1966 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1967
1968 /* Make sure that the ABORT chunk has a valid length.
1969 * Since this is an ABORT chunk, we have to discard it
1970 * because of the following text:
1971 * RFC 2960, Section 3.3.7
1972 * If an endpoint receives an ABORT with a format error or for an
1973 * association that doesn't exist, it MUST silently discard it.
1974 * Becasue the length is "invalid", we can't really discard just
1975 * as we do not know its true length. So, to be safe, discard the
1976 * packet.
1977 */
1978 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
1979 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1980
1981 /* Stop the T5-shutdown guard timer. */
1982 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1983 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
1984
1985 return sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
1986}
1987
1988/*
1989 * Process an ABORT. (SHUTDOWN-SENT state)
1990 *
1991 * See sctp_sf_do_9_1_abort().
1992 */
1993sctp_disposition_t sctp_sf_shutdown_sent_abort(const struct sctp_endpoint *ep,
1994 const struct sctp_association *asoc,
1995 const sctp_subtype_t type,
1996 void *arg,
1997 sctp_cmd_seq_t *commands)
1998{
1999 struct sctp_chunk *chunk = arg;
2000
2001 if (!sctp_vtag_verify_either(chunk, asoc))
2002 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2003
2004 /* Make sure that the ABORT chunk has a valid length.
2005 * Since this is an ABORT chunk, we have to discard it
2006 * because of the following text:
2007 * RFC 2960, Section 3.3.7
2008 * If an endpoint receives an ABORT with a format error or for an
2009 * association that doesn't exist, it MUST silently discard it.
2010 * Becasue the length is "invalid", we can't really discard just
2011 * as we do not know its true length. So, to be safe, discard the
2012 * packet.
2013 */
2014 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2015 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2016
2017 /* Stop the T2-shutdown timer. */
2018 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2019 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2020
2021 /* Stop the T5-shutdown guard timer. */
2022 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2023 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
2024
2025 return sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
2026}
2027
2028/*
2029 * Process an ABORT. (SHUTDOWN-ACK-SENT state)
2030 *
2031 * See sctp_sf_do_9_1_abort().
2032 */
2033sctp_disposition_t sctp_sf_shutdown_ack_sent_abort(
2034 const struct sctp_endpoint *ep,
2035 const struct sctp_association *asoc,
2036 const sctp_subtype_t type,
2037 void *arg,
2038 sctp_cmd_seq_t *commands)
2039{
2040 /* The same T2 timer, so we should be able to use
2041 * common function with the SHUTDOWN-SENT state.
2042 */
2043 return sctp_sf_shutdown_sent_abort(ep, asoc, type, arg, commands);
2044}
2045
2046/*
2047 * Handle an Error received in COOKIE_ECHOED state.
2048 *
2049 * Only handle the error type of stale COOKIE Error, the other errors will
2050 * be ignored.
2051 *
2052 * Inputs
2053 * (endpoint, asoc, chunk)
2054 *
2055 * Outputs
2056 * (asoc, reply_msg, msg_up, timers, counters)
2057 *
2058 * The return value is the disposition of the chunk.
2059 */
2060sctp_disposition_t sctp_sf_cookie_echoed_err(const struct sctp_endpoint *ep,
2061 const struct sctp_association *asoc,
2062 const sctp_subtype_t type,
2063 void *arg,
2064 sctp_cmd_seq_t *commands)
2065{
2066 struct sctp_chunk *chunk = arg;
2067 sctp_errhdr_t *err;
2068
2069 if (!sctp_vtag_verify(chunk, asoc))
2070 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2071
2072 /* Make sure that the ERROR chunk has a valid length.
2073 * The parameter walking depends on this as well.
2074 */
2075 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
2076 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2077 commands);
2078
2079 /* Process the error here */
2080 /* FUTURE FIXME: When PR-SCTP related and other optional
2081 * parms are emitted, this will have to change to handle multiple
2082 * errors.
2083 */
2084 sctp_walk_errors(err, chunk->chunk_hdr) {
2085 if (SCTP_ERROR_STALE_COOKIE == err->cause)
2086 return sctp_sf_do_5_2_6_stale(ep, asoc, type,
2087 arg, commands);
2088 }
2089
2090 /* It is possible to have malformed error causes, and that
2091 * will cause us to end the walk early. However, since
2092 * we are discarding the packet, there should be no adverse
2093 * affects.
2094 */
2095 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2096}
2097
2098/*
2099 * Handle a Stale COOKIE Error
2100 *
2101 * Section: 5.2.6 Handle Stale COOKIE Error
2102 * If the association is in the COOKIE-ECHOED state, the endpoint may elect
2103 * one of the following three alternatives.
2104 * ...
2105 * 3) Send a new INIT chunk to the endpoint, adding a Cookie
2106 * Preservative parameter requesting an extension to the lifetime of
2107 * the State Cookie. When calculating the time extension, an
2108 * implementation SHOULD use the RTT information measured based on the
2109 * previous COOKIE ECHO / ERROR exchange, and should add no more
2110 * than 1 second beyond the measured RTT, due to long State Cookie
2111 * lifetimes making the endpoint more subject to a replay attack.
2112 *
2113 * Verification Tag: Not explicit, but safe to ignore.
2114 *
2115 * Inputs
2116 * (endpoint, asoc, chunk)
2117 *
2118 * Outputs
2119 * (asoc, reply_msg, msg_up, timers, counters)
2120 *
2121 * The return value is the disposition of the chunk.
2122 */
2123static sctp_disposition_t sctp_sf_do_5_2_6_stale(const struct sctp_endpoint *ep,
2124 const struct sctp_association *asoc,
2125 const sctp_subtype_t type,
2126 void *arg,
2127 sctp_cmd_seq_t *commands)
2128{
2129 struct sctp_chunk *chunk = arg;
2130 time_t stale;
2131 sctp_cookie_preserve_param_t bht;
2132 sctp_errhdr_t *err;
2133 struct sctp_chunk *reply;
2134 struct sctp_bind_addr *bp;
Frank Filz3f7a87d2005-06-20 13:14:57 -07002135 int attempts = asoc->init_err_counter + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002136
Vlad Yasevich81845c22006-01-30 15:59:54 -08002137 if (attempts > asoc->max_init_attempts) {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002138 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
2139 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002140 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08002141 SCTP_PERR(SCTP_ERROR_STALE_COOKIE));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002142 return SCTP_DISPOSITION_DELETE_TCB;
2143 }
2144
2145 err = (sctp_errhdr_t *)(chunk->skb->data);
2146
2147 /* When calculating the time extension, an implementation
2148 * SHOULD use the RTT information measured based on the
2149 * previous COOKIE ECHO / ERROR exchange, and should add no
2150 * more than 1 second beyond the measured RTT, due to long
2151 * State Cookie lifetimes making the endpoint more subject to
2152 * a replay attack.
2153 * Measure of Staleness's unit is usec. (1/1000000 sec)
2154 * Suggested Cookie Life-span Increment's unit is msec.
2155 * (1/1000 sec)
2156 * In general, if you use the suggested cookie life, the value
2157 * found in the field of measure of staleness should be doubled
2158 * to give ample time to retransmit the new cookie and thus
2159 * yield a higher probability of success on the reattempt.
2160 */
Al Viro34bcca22006-11-20 17:27:15 -08002161 stale = ntohl(*(__be32 *)((u8 *)err + sizeof(sctp_errhdr_t)));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002162 stale = (stale * 2) / 1000;
2163
2164 bht.param_hdr.type = SCTP_PARAM_COOKIE_PRESERVATIVE;
2165 bht.param_hdr.length = htons(sizeof(bht));
2166 bht.lifespan_increment = htonl(stale);
2167
2168 /* Build that new INIT chunk. */
2169 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
2170 reply = sctp_make_init(asoc, bp, GFP_ATOMIC, sizeof(bht));
2171 if (!reply)
2172 goto nomem;
2173
2174 sctp_addto_chunk(reply, sizeof(bht), &bht);
2175
2176 /* Clear peer's init_tag cached in assoc as we are sending a new INIT */
2177 sctp_add_cmd_sf(commands, SCTP_CMD_CLEAR_INIT_TAG, SCTP_NULL());
2178
2179 /* Stop pending T3-rtx and heartbeat timers */
2180 sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
2181 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
2182
2183 /* Delete non-primary peer ip addresses since we are transitioning
2184 * back to the COOKIE-WAIT state
2185 */
2186 sctp_add_cmd_sf(commands, SCTP_CMD_DEL_NON_PRIMARY, SCTP_NULL());
2187
2188 /* If we've sent any data bundled with COOKIE-ECHO we will need to
2189 * resend
2190 */
2191 sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN,
2192 SCTP_TRANSPORT(asoc->peer.primary_path));
2193
2194 /* Cast away the const modifier, as we want to just
2195 * rerun it through as a sideffect.
2196 */
Frank Filz3f7a87d2005-06-20 13:14:57 -07002197 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_INC, SCTP_NULL());
Linus Torvalds1da177e2005-04-16 15:20:36 -07002198
2199 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2200 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
2201 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2202 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
2203 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
2204 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
2205
2206 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2207
2208 return SCTP_DISPOSITION_CONSUME;
2209
2210nomem:
2211 return SCTP_DISPOSITION_NOMEM;
2212}
2213
2214/*
2215 * Process an ABORT.
2216 *
2217 * Section: 9.1
2218 * After checking the Verification Tag, the receiving endpoint shall
2219 * remove the association from its record, and shall report the
2220 * termination to its upper layer.
2221 *
2222 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
2223 * B) Rules for packet carrying ABORT:
2224 *
2225 * - The endpoint shall always fill in the Verification Tag field of the
2226 * outbound packet with the destination endpoint's tag value if it
2227 * is known.
2228 *
2229 * - If the ABORT is sent in response to an OOTB packet, the endpoint
2230 * MUST follow the procedure described in Section 8.4.
2231 *
2232 * - The receiver MUST accept the packet if the Verification Tag
2233 * matches either its own tag, OR the tag of its peer. Otherwise, the
2234 * receiver MUST silently discard the packet and take no further
2235 * action.
2236 *
2237 * Inputs
2238 * (endpoint, asoc, chunk)
2239 *
2240 * Outputs
2241 * (asoc, reply_msg, msg_up, timers, counters)
2242 *
2243 * The return value is the disposition of the chunk.
2244 */
2245sctp_disposition_t sctp_sf_do_9_1_abort(const struct sctp_endpoint *ep,
2246 const struct sctp_association *asoc,
2247 const sctp_subtype_t type,
2248 void *arg,
2249 sctp_cmd_seq_t *commands)
2250{
2251 struct sctp_chunk *chunk = arg;
2252 unsigned len;
Al Viro5be291f2006-11-20 17:01:06 -08002253 __be16 error = SCTP_ERROR_NO_ERROR;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002254
2255 if (!sctp_vtag_verify_either(chunk, asoc))
2256 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2257
2258 /* Make sure that the ABORT chunk has a valid length.
2259 * Since this is an ABORT chunk, we have to discard it
2260 * because of the following text:
2261 * RFC 2960, Section 3.3.7
2262 * If an endpoint receives an ABORT with a format error or for an
2263 * association that doesn't exist, it MUST silently discard it.
2264 * Becasue the length is "invalid", we can't really discard just
2265 * as we do not know its true length. So, to be safe, discard the
2266 * packet.
2267 */
2268 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2269 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2270
2271 /* See if we have an error cause code in the chunk. */
2272 len = ntohs(chunk->chunk_hdr->length);
2273 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
2274 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2275
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002276 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNRESET));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002277 /* ASSOC_FAILED will DELETE_TCB. */
Al Viro5be291f2006-11-20 17:01:06 -08002278 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, SCTP_PERR(error));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002279 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
2280 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
2281
2282 return SCTP_DISPOSITION_ABORT;
2283}
2284
2285/*
2286 * Process an ABORT. (COOKIE-WAIT state)
2287 *
2288 * See sctp_sf_do_9_1_abort() above.
2289 */
2290sctp_disposition_t sctp_sf_cookie_wait_abort(const struct sctp_endpoint *ep,
2291 const struct sctp_association *asoc,
2292 const sctp_subtype_t type,
2293 void *arg,
2294 sctp_cmd_seq_t *commands)
2295{
2296 struct sctp_chunk *chunk = arg;
2297 unsigned len;
Al Virof94c0192006-11-20 17:00:25 -08002298 __be16 error = SCTP_ERROR_NO_ERROR;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002299
2300 if (!sctp_vtag_verify_either(chunk, asoc))
2301 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2302
2303 /* Make sure that the ABORT chunk has a valid length.
2304 * Since this is an ABORT chunk, we have to discard it
2305 * because of the following text:
2306 * RFC 2960, Section 3.3.7
2307 * If an endpoint receives an ABORT with a format error or for an
2308 * association that doesn't exist, it MUST silently discard it.
2309 * Becasue the length is "invalid", we can't really discard just
2310 * as we do not know its true length. So, to be safe, discard the
2311 * packet.
2312 */
2313 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2314 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2315
2316 /* See if we have an error cause code in the chunk. */
2317 len = ntohs(chunk->chunk_hdr->length);
2318 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
2319 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2320
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002321 return sctp_stop_t1_and_abort(commands, error, ECONNREFUSED, asoc,
2322 chunk->transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002323}
2324
2325/*
2326 * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state)
2327 */
2328sctp_disposition_t sctp_sf_cookie_wait_icmp_abort(const struct sctp_endpoint *ep,
2329 const struct sctp_association *asoc,
2330 const sctp_subtype_t type,
2331 void *arg,
2332 sctp_cmd_seq_t *commands)
2333{
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002334 return sctp_stop_t1_and_abort(commands, SCTP_ERROR_NO_ERROR,
2335 ENOPROTOOPT, asoc,
Frank Filz3f7a87d2005-06-20 13:14:57 -07002336 (struct sctp_transport *)arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002337}
2338
2339/*
2340 * Process an ABORT. (COOKIE-ECHOED state)
2341 */
2342sctp_disposition_t sctp_sf_cookie_echoed_abort(const struct sctp_endpoint *ep,
2343 const struct sctp_association *asoc,
2344 const sctp_subtype_t type,
2345 void *arg,
2346 sctp_cmd_seq_t *commands)
2347{
2348 /* There is a single T1 timer, so we should be able to use
2349 * common function with the COOKIE-WAIT state.
2350 */
2351 return sctp_sf_cookie_wait_abort(ep, asoc, type, arg, commands);
2352}
2353
2354/*
2355 * Stop T1 timer and abort association with "INIT failed".
2356 *
2357 * This is common code called by several sctp_sf_*_abort() functions above.
2358 */
Adrian Bunk52c1da32005-06-23 22:05:33 -07002359static sctp_disposition_t sctp_stop_t1_and_abort(sctp_cmd_seq_t *commands,
Al Virof94c0192006-11-20 17:00:25 -08002360 __be16 error, int sk_err,
Frank Filz3f7a87d2005-06-20 13:14:57 -07002361 const struct sctp_association *asoc,
2362 struct sctp_transport *transport)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002363{
Frank Filz3f7a87d2005-06-20 13:14:57 -07002364 SCTP_DEBUG_PRINTK("ABORT received (INIT).\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07002365 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2366 SCTP_STATE(SCTP_STATE_CLOSED));
2367 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
2368 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2369 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002370 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(sk_err));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002371 /* CMD_INIT_FAILED will DELETE_TCB. */
2372 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08002373 SCTP_PERR(error));
Frank Filz3f7a87d2005-06-20 13:14:57 -07002374 return SCTP_DISPOSITION_ABORT;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002375}
2376
2377/*
2378 * sctp_sf_do_9_2_shut
2379 *
2380 * Section: 9.2
2381 * Upon the reception of the SHUTDOWN, the peer endpoint shall
2382 * - enter the SHUTDOWN-RECEIVED state,
2383 *
2384 * - stop accepting new data from its SCTP user
2385 *
2386 * - verify, by checking the Cumulative TSN Ack field of the chunk,
2387 * that all its outstanding DATA chunks have been received by the
2388 * SHUTDOWN sender.
2389 *
2390 * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT
2391 * send a SHUTDOWN in response to a ULP request. And should discard
2392 * subsequent SHUTDOWN chunks.
2393 *
2394 * If there are still outstanding DATA chunks left, the SHUTDOWN
2395 * receiver shall continue to follow normal data transmission
2396 * procedures defined in Section 6 until all outstanding DATA chunks
2397 * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept
2398 * new data from its SCTP user.
2399 *
2400 * Verification Tag: 8.5 Verification Tag [Normal verification]
2401 *
2402 * Inputs
2403 * (endpoint, asoc, chunk)
2404 *
2405 * Outputs
2406 * (asoc, reply_msg, msg_up, timers, counters)
2407 *
2408 * The return value is the disposition of the chunk.
2409 */
2410sctp_disposition_t sctp_sf_do_9_2_shutdown(const struct sctp_endpoint *ep,
2411 const struct sctp_association *asoc,
2412 const sctp_subtype_t type,
2413 void *arg,
2414 sctp_cmd_seq_t *commands)
2415{
2416 struct sctp_chunk *chunk = arg;
2417 sctp_shutdownhdr_t *sdh;
2418 sctp_disposition_t disposition;
2419 struct sctp_ulpevent *ev;
2420
2421 if (!sctp_vtag_verify(chunk, asoc))
2422 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2423
2424 /* Make sure that the SHUTDOWN chunk has a valid length. */
2425 if (!sctp_chunk_length_valid(chunk,
2426 sizeof(struct sctp_shutdown_chunk_t)))
2427 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2428 commands);
2429
2430 /* Convert the elaborate header. */
2431 sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
2432 skb_pull(chunk->skb, sizeof(sctp_shutdownhdr_t));
2433 chunk->subh.shutdown_hdr = sdh;
2434
Sridhar Samudralaeb0e0072005-09-22 23:48:38 -07002435 /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT
2436 * When a peer sends a SHUTDOWN, SCTP delivers this notification to
2437 * inform the application that it should cease sending data.
2438 */
2439 ev = sctp_ulpevent_make_shutdown_event(asoc, 0, GFP_ATOMIC);
2440 if (!ev) {
2441 disposition = SCTP_DISPOSITION_NOMEM;
2442 goto out;
2443 }
2444 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
2445
Linus Torvalds1da177e2005-04-16 15:20:36 -07002446 /* Upon the reception of the SHUTDOWN, the peer endpoint shall
2447 * - enter the SHUTDOWN-RECEIVED state,
2448 * - stop accepting new data from its SCTP user
2449 *
2450 * [This is implicit in the new state.]
2451 */
2452 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2453 SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED));
2454 disposition = SCTP_DISPOSITION_CONSUME;
2455
2456 if (sctp_outq_is_empty(&asoc->outqueue)) {
2457 disposition = sctp_sf_do_9_2_shutdown_ack(ep, asoc, type,
2458 arg, commands);
2459 }
2460
2461 if (SCTP_DISPOSITION_NOMEM == disposition)
2462 goto out;
2463
2464 /* - verify, by checking the Cumulative TSN Ack field of the
2465 * chunk, that all its outstanding DATA chunks have been
2466 * received by the SHUTDOWN sender.
2467 */
2468 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
Al Viro2178eda2006-11-20 17:26:53 -08002469 SCTP_BE32(chunk->subh.shutdown_hdr->cum_tsn_ack));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002470
Linus Torvalds1da177e2005-04-16 15:20:36 -07002471out:
2472 return disposition;
2473}
2474
2475/* RFC 2960 9.2
2476 * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk
2477 * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination
2478 * transport addresses (either in the IP addresses or in the INIT chunk)
2479 * that belong to this association, it should discard the INIT chunk and
2480 * retransmit the SHUTDOWN ACK chunk.
2481 */
2482sctp_disposition_t sctp_sf_do_9_2_reshutack(const struct sctp_endpoint *ep,
2483 const struct sctp_association *asoc,
2484 const sctp_subtype_t type,
2485 void *arg,
2486 sctp_cmd_seq_t *commands)
2487{
2488 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
2489 struct sctp_chunk *reply;
2490
2491 /* Since we are not going to really process this INIT, there
2492 * is no point in verifying chunk boundries. Just generate
2493 * the SHUTDOWN ACK.
2494 */
2495 reply = sctp_make_shutdown_ack(asoc, chunk);
2496 if (NULL == reply)
2497 goto nomem;
2498
2499 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
2500 * the T2-SHUTDOWN timer.
2501 */
2502 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
2503
2504 /* and restart the T2-shutdown timer. */
2505 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2506 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2507
2508 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2509
2510 return SCTP_DISPOSITION_CONSUME;
2511nomem:
2512 return SCTP_DISPOSITION_NOMEM;
2513}
2514
2515/*
2516 * sctp_sf_do_ecn_cwr
2517 *
2518 * Section: Appendix A: Explicit Congestion Notification
2519 *
2520 * CWR:
2521 *
2522 * RFC 2481 details a specific bit for a sender to send in the header of
2523 * its next outbound TCP segment to indicate to its peer that it has
2524 * reduced its congestion window. This is termed the CWR bit. For
2525 * SCTP the same indication is made by including the CWR chunk.
2526 * This chunk contains one data element, i.e. the TSN number that
2527 * was sent in the ECNE chunk. This element represents the lowest
2528 * TSN number in the datagram that was originally marked with the
2529 * CE bit.
2530 *
2531 * Verification Tag: 8.5 Verification Tag [Normal verification]
2532 * Inputs
2533 * (endpoint, asoc, chunk)
2534 *
2535 * Outputs
2536 * (asoc, reply_msg, msg_up, timers, counters)
2537 *
2538 * The return value is the disposition of the chunk.
2539 */
2540sctp_disposition_t sctp_sf_do_ecn_cwr(const struct sctp_endpoint *ep,
2541 const struct sctp_association *asoc,
2542 const sctp_subtype_t type,
2543 void *arg,
2544 sctp_cmd_seq_t *commands)
2545{
2546 sctp_cwrhdr_t *cwr;
2547 struct sctp_chunk *chunk = arg;
Al Viro34bcca22006-11-20 17:27:15 -08002548 u32 lowest_tsn;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002549
2550 if (!sctp_vtag_verify(chunk, asoc))
2551 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2552
2553 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2554 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2555 commands);
2556
2557 cwr = (sctp_cwrhdr_t *) chunk->skb->data;
2558 skb_pull(chunk->skb, sizeof(sctp_cwrhdr_t));
2559
Al Viro34bcca22006-11-20 17:27:15 -08002560 lowest_tsn = ntohl(cwr->lowest_tsn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002561
2562 /* Does this CWR ack the last sent congestion notification? */
Al Viro34bcca22006-11-20 17:27:15 -08002563 if (TSN_lte(asoc->last_ecne_tsn, lowest_tsn)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002564 /* Stop sending ECNE. */
2565 sctp_add_cmd_sf(commands,
2566 SCTP_CMD_ECN_CWR,
Al Viro34bcca22006-11-20 17:27:15 -08002567 SCTP_U32(lowest_tsn));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002568 }
2569 return SCTP_DISPOSITION_CONSUME;
2570}
2571
2572/*
2573 * sctp_sf_do_ecne
2574 *
2575 * Section: Appendix A: Explicit Congestion Notification
2576 *
2577 * ECN-Echo
2578 *
2579 * RFC 2481 details a specific bit for a receiver to send back in its
2580 * TCP acknowledgements to notify the sender of the Congestion
2581 * Experienced (CE) bit having arrived from the network. For SCTP this
2582 * same indication is made by including the ECNE chunk. This chunk
2583 * contains one data element, i.e. the lowest TSN associated with the IP
2584 * datagram marked with the CE bit.....
2585 *
2586 * Verification Tag: 8.5 Verification Tag [Normal verification]
2587 * Inputs
2588 * (endpoint, asoc, chunk)
2589 *
2590 * Outputs
2591 * (asoc, reply_msg, msg_up, timers, counters)
2592 *
2593 * The return value is the disposition of the chunk.
2594 */
2595sctp_disposition_t sctp_sf_do_ecne(const struct sctp_endpoint *ep,
2596 const struct sctp_association *asoc,
2597 const sctp_subtype_t type,
2598 void *arg,
2599 sctp_cmd_seq_t *commands)
2600{
2601 sctp_ecnehdr_t *ecne;
2602 struct sctp_chunk *chunk = arg;
2603
2604 if (!sctp_vtag_verify(chunk, asoc))
2605 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2606
2607 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2608 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2609 commands);
2610
2611 ecne = (sctp_ecnehdr_t *) chunk->skb->data;
2612 skb_pull(chunk->skb, sizeof(sctp_ecnehdr_t));
2613
2614 /* If this is a newer ECNE than the last CWR packet we sent out */
2615 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_ECNE,
2616 SCTP_U32(ntohl(ecne->lowest_tsn)));
2617
2618 return SCTP_DISPOSITION_CONSUME;
2619}
2620
2621/*
2622 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
2623 *
2624 * The SCTP endpoint MUST always acknowledge the reception of each valid
2625 * DATA chunk.
2626 *
2627 * The guidelines on delayed acknowledgement algorithm specified in
2628 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
2629 * acknowledgement SHOULD be generated for at least every second packet
2630 * (not every second DATA chunk) received, and SHOULD be generated within
2631 * 200 ms of the arrival of any unacknowledged DATA chunk. In some
2632 * situations it may be beneficial for an SCTP transmitter to be more
2633 * conservative than the algorithms detailed in this document allow.
2634 * However, an SCTP transmitter MUST NOT be more aggressive than the
2635 * following algorithms allow.
2636 *
2637 * A SCTP receiver MUST NOT generate more than one SACK for every
2638 * incoming packet, other than to update the offered window as the
2639 * receiving application consumes new data.
2640 *
2641 * Verification Tag: 8.5 Verification Tag [Normal verification]
2642 *
2643 * Inputs
2644 * (endpoint, asoc, chunk)
2645 *
2646 * Outputs
2647 * (asoc, reply_msg, msg_up, timers, counters)
2648 *
2649 * The return value is the disposition of the chunk.
2650 */
2651sctp_disposition_t sctp_sf_eat_data_6_2(const struct sctp_endpoint *ep,
2652 const struct sctp_association *asoc,
2653 const sctp_subtype_t type,
2654 void *arg,
2655 sctp_cmd_seq_t *commands)
2656{
2657 struct sctp_chunk *chunk = arg;
2658 int error;
2659
2660 if (!sctp_vtag_verify(chunk, asoc)) {
2661 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
2662 SCTP_NULL());
2663 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2664 }
2665
2666 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
2667 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2668 commands);
2669
2670 error = sctp_eat_data(asoc, chunk, commands );
2671 switch (error) {
2672 case SCTP_IERROR_NO_ERROR:
2673 break;
2674 case SCTP_IERROR_HIGH_TSN:
2675 case SCTP_IERROR_BAD_STREAM:
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07002676 SCTP_INC_STATS(SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002677 goto discard_noforce;
2678 case SCTP_IERROR_DUP_TSN:
2679 case SCTP_IERROR_IGNORE_TSN:
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07002680 SCTP_INC_STATS(SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002681 goto discard_force;
2682 case SCTP_IERROR_NO_DATA:
2683 goto consume;
2684 default:
2685 BUG();
2686 }
2687
2688 if (asoc->autoclose) {
2689 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2690 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
2691 }
2692
2693 /* If this is the last chunk in a packet, we need to count it
2694 * toward sack generation. Note that we need to SACK every
2695 * OTHER packet containing data chunks, EVEN IF WE DISCARD
2696 * THEM. We elect to NOT generate SACK's if the chunk fails
2697 * the verification tag test.
2698 *
2699 * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2700 *
2701 * The SCTP endpoint MUST always acknowledge the reception of
2702 * each valid DATA chunk.
2703 *
2704 * The guidelines on delayed acknowledgement algorithm
2705 * specified in Section 4.2 of [RFC2581] SHOULD be followed.
2706 * Specifically, an acknowledgement SHOULD be generated for at
2707 * least every second packet (not every second DATA chunk)
2708 * received, and SHOULD be generated within 200 ms of the
2709 * arrival of any unacknowledged DATA chunk. In some
2710 * situations it may be beneficial for an SCTP transmitter to
2711 * be more conservative than the algorithms detailed in this
2712 * document allow. However, an SCTP transmitter MUST NOT be
2713 * more aggressive than the following algorithms allow.
2714 */
Frank Filz52ccb8e2005-12-22 11:36:46 -08002715 if (chunk->end_of_packet)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002716 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
2717
Linus Torvalds1da177e2005-04-16 15:20:36 -07002718 return SCTP_DISPOSITION_CONSUME;
2719
2720discard_force:
2721 /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2722 *
2723 * When a packet arrives with duplicate DATA chunk(s) and with
2724 * no new DATA chunk(s), the endpoint MUST immediately send a
2725 * SACK with no delay. If a packet arrives with duplicate
2726 * DATA chunk(s) bundled with new DATA chunks, the endpoint
2727 * MAY immediately send a SACK. Normally receipt of duplicate
2728 * DATA chunks will occur when the original SACK chunk was lost
2729 * and the peer's RTO has expired. The duplicate TSN number(s)
2730 * SHOULD be reported in the SACK as duplicate.
2731 */
2732 /* In our case, we split the MAY SACK advice up whether or not
2733 * the last chunk is a duplicate.'
2734 */
2735 if (chunk->end_of_packet)
2736 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
2737 return SCTP_DISPOSITION_DISCARD;
2738
2739discard_noforce:
Frank Filz52ccb8e2005-12-22 11:36:46 -08002740 if (chunk->end_of_packet)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002741 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
2742
Linus Torvalds1da177e2005-04-16 15:20:36 -07002743 return SCTP_DISPOSITION_DISCARD;
2744consume:
2745 return SCTP_DISPOSITION_CONSUME;
2746
2747}
2748
2749/*
2750 * sctp_sf_eat_data_fast_4_4
2751 *
2752 * Section: 4 (4)
2753 * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received
2754 * DATA chunks without delay.
2755 *
2756 * Verification Tag: 8.5 Verification Tag [Normal verification]
2757 * Inputs
2758 * (endpoint, asoc, chunk)
2759 *
2760 * Outputs
2761 * (asoc, reply_msg, msg_up, timers, counters)
2762 *
2763 * The return value is the disposition of the chunk.
2764 */
2765sctp_disposition_t sctp_sf_eat_data_fast_4_4(const struct sctp_endpoint *ep,
2766 const struct sctp_association *asoc,
2767 const sctp_subtype_t type,
2768 void *arg,
2769 sctp_cmd_seq_t *commands)
2770{
2771 struct sctp_chunk *chunk = arg;
2772 int error;
2773
2774 if (!sctp_vtag_verify(chunk, asoc)) {
2775 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
2776 SCTP_NULL());
2777 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2778 }
2779
2780 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
2781 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2782 commands);
2783
2784 error = sctp_eat_data(asoc, chunk, commands );
2785 switch (error) {
2786 case SCTP_IERROR_NO_ERROR:
2787 case SCTP_IERROR_HIGH_TSN:
2788 case SCTP_IERROR_DUP_TSN:
2789 case SCTP_IERROR_IGNORE_TSN:
2790 case SCTP_IERROR_BAD_STREAM:
2791 break;
2792 case SCTP_IERROR_NO_DATA:
2793 goto consume;
2794 default:
2795 BUG();
2796 }
2797
2798 /* Go a head and force a SACK, since we are shutting down. */
2799
2800 /* Implementor's Guide.
2801 *
2802 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
2803 * respond to each received packet containing one or more DATA chunk(s)
2804 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
2805 */
2806 if (chunk->end_of_packet) {
2807 /* We must delay the chunk creation since the cumulative
2808 * TSN has not been updated yet.
2809 */
2810 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
2811 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
2812 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2813 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2814 }
2815
2816consume:
2817 return SCTP_DISPOSITION_CONSUME;
2818}
2819
2820/*
2821 * Section: 6.2 Processing a Received SACK
2822 * D) Any time a SACK arrives, the endpoint performs the following:
2823 *
2824 * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point,
2825 * then drop the SACK. Since Cumulative TSN Ack is monotonically
2826 * increasing, a SACK whose Cumulative TSN Ack is less than the
2827 * Cumulative TSN Ack Point indicates an out-of-order SACK.
2828 *
2829 * ii) Set rwnd equal to the newly received a_rwnd minus the number
2830 * of bytes still outstanding after processing the Cumulative TSN Ack
2831 * and the Gap Ack Blocks.
2832 *
2833 * iii) If the SACK is missing a TSN that was previously
2834 * acknowledged via a Gap Ack Block (e.g., the data receiver
2835 * reneged on the data), then mark the corresponding DATA chunk
2836 * as available for retransmit: Mark it as missing for fast
2837 * retransmit as described in Section 7.2.4 and if no retransmit
2838 * timer is running for the destination address to which the DATA
2839 * chunk was originally transmitted, then T3-rtx is started for
2840 * that destination address.
2841 *
2842 * Verification Tag: 8.5 Verification Tag [Normal verification]
2843 *
2844 * Inputs
2845 * (endpoint, asoc, chunk)
2846 *
2847 * Outputs
2848 * (asoc, reply_msg, msg_up, timers, counters)
2849 *
2850 * The return value is the disposition of the chunk.
2851 */
2852sctp_disposition_t sctp_sf_eat_sack_6_2(const struct sctp_endpoint *ep,
2853 const struct sctp_association *asoc,
2854 const sctp_subtype_t type,
2855 void *arg,
2856 sctp_cmd_seq_t *commands)
2857{
2858 struct sctp_chunk *chunk = arg;
2859 sctp_sackhdr_t *sackh;
2860 __u32 ctsn;
2861
2862 if (!sctp_vtag_verify(chunk, asoc))
2863 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2864
2865 /* Make sure that the SACK chunk has a valid length. */
2866 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_sack_chunk_t)))
2867 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2868 commands);
2869
2870 /* Pull the SACK chunk from the data buffer */
2871 sackh = sctp_sm_pull_sack(chunk);
2872 /* Was this a bogus SACK? */
2873 if (!sackh)
2874 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2875 chunk->subh.sack_hdr = sackh;
2876 ctsn = ntohl(sackh->cum_tsn_ack);
2877
2878 /* i) If Cumulative TSN Ack is less than the Cumulative TSN
2879 * Ack Point, then drop the SACK. Since Cumulative TSN
2880 * Ack is monotonically increasing, a SACK whose
2881 * Cumulative TSN Ack is less than the Cumulative TSN Ack
2882 * Point indicates an out-of-order SACK.
2883 */
2884 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
2885 SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn);
2886 SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc->ctsn_ack_point);
2887 return SCTP_DISPOSITION_DISCARD;
2888 }
2889
2890 /* Return this SACK for further processing. */
2891 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_SACKH(sackh));
2892
2893 /* Note: We do the rest of the work on the PROCESS_SACK
2894 * sideeffect.
2895 */
2896 return SCTP_DISPOSITION_CONSUME;
2897}
2898
2899/*
2900 * Generate an ABORT in response to a packet.
2901 *
Jerome Forissier047a2422005-04-28 11:58:43 -07002902 * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41
Linus Torvalds1da177e2005-04-16 15:20:36 -07002903 *
Jerome Forissier047a2422005-04-28 11:58:43 -07002904 * 8) The receiver should respond to the sender of the OOTB packet with
2905 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
2906 * MUST fill in the Verification Tag field of the outbound packet
2907 * with the value found in the Verification Tag field of the OOTB
2908 * packet and set the T-bit in the Chunk Flags to indicate that the
2909 * Verification Tag is reflected. After sending this ABORT, the
2910 * receiver of the OOTB packet shall discard the OOTB packet and take
2911 * no further action.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002912 *
2913 * Verification Tag:
2914 *
2915 * The return value is the disposition of the chunk.
2916*/
2917sctp_disposition_t sctp_sf_tabort_8_4_8(const struct sctp_endpoint *ep,
2918 const struct sctp_association *asoc,
2919 const sctp_subtype_t type,
2920 void *arg,
2921 sctp_cmd_seq_t *commands)
2922{
2923 struct sctp_packet *packet = NULL;
2924 struct sctp_chunk *chunk = arg;
2925 struct sctp_chunk *abort;
2926
2927 packet = sctp_ootb_pkt_new(asoc, chunk);
2928
2929 if (packet) {
2930 /* Make an ABORT. The T bit will be set if the asoc
2931 * is NULL.
2932 */
2933 abort = sctp_make_abort(asoc, chunk, 0);
2934 if (!abort) {
2935 sctp_ootb_pkt_free(packet);
2936 return SCTP_DISPOSITION_NOMEM;
2937 }
2938
Jerome Forissier047a2422005-04-28 11:58:43 -07002939 /* Reflect vtag if T-Bit is set */
2940 if (sctp_test_T_bit(abort))
2941 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
2942
Linus Torvalds1da177e2005-04-16 15:20:36 -07002943 /* Set the skb to the belonging sock for accounting. */
2944 abort->skb->sk = ep->base.sk;
2945
2946 sctp_packet_append_chunk(packet, abort);
2947
2948 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
2949 SCTP_PACKET(packet));
2950
2951 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
2952
2953 return SCTP_DISPOSITION_CONSUME;
2954 }
2955
2956 return SCTP_DISPOSITION_NOMEM;
2957}
2958
2959/*
2960 * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR
2961 * event as ULP notification for each cause included in the chunk.
2962 *
2963 * API 5.3.1.3 - SCTP_REMOTE_ERROR
2964 *
2965 * The return value is the disposition of the chunk.
2966*/
2967sctp_disposition_t sctp_sf_operr_notify(const struct sctp_endpoint *ep,
2968 const struct sctp_association *asoc,
2969 const sctp_subtype_t type,
2970 void *arg,
2971 sctp_cmd_seq_t *commands)
2972{
2973 struct sctp_chunk *chunk = arg;
2974 struct sctp_ulpevent *ev;
2975
2976 if (!sctp_vtag_verify(chunk, asoc))
2977 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2978
2979 /* Make sure that the ERROR chunk has a valid length. */
2980 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
2981 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2982 commands);
2983
2984 while (chunk->chunk_end > chunk->skb->data) {
2985 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
2986 GFP_ATOMIC);
2987 if (!ev)
2988 goto nomem;
2989
2990 if (!sctp_add_cmd(commands, SCTP_CMD_EVENT_ULP,
2991 SCTP_ULPEVENT(ev))) {
2992 sctp_ulpevent_free(ev);
2993 goto nomem;
2994 }
2995
2996 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_OPERR,
2997 SCTP_CHUNK(chunk));
2998 }
2999 return SCTP_DISPOSITION_CONSUME;
3000
3001nomem:
3002 return SCTP_DISPOSITION_NOMEM;
3003}
3004
3005/*
3006 * Process an inbound SHUTDOWN ACK.
3007 *
3008 * From Section 9.2:
3009 * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3010 * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its
3011 * peer, and remove all record of the association.
3012 *
3013 * The return value is the disposition.
3014 */
3015sctp_disposition_t sctp_sf_do_9_2_final(const struct sctp_endpoint *ep,
3016 const struct sctp_association *asoc,
3017 const sctp_subtype_t type,
3018 void *arg,
3019 sctp_cmd_seq_t *commands)
3020{
3021 struct sctp_chunk *chunk = arg;
3022 struct sctp_chunk *reply;
3023 struct sctp_ulpevent *ev;
3024
3025 if (!sctp_vtag_verify(chunk, asoc))
3026 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3027
3028 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3029 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3030 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3031 commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003032 /* 10.2 H) SHUTDOWN COMPLETE notification
3033 *
3034 * When SCTP completes the shutdown procedures (section 9.2) this
3035 * notification is passed to the upper layer.
3036 */
3037 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
3038 0, 0, 0, GFP_ATOMIC);
3039 if (!ev)
3040 goto nomem;
3041
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07003042 /* ...send a SHUTDOWN COMPLETE chunk to its peer, */
3043 reply = sctp_make_shutdown_complete(asoc, chunk);
3044 if (!reply)
3045 goto nomem_chunk;
3046
3047 /* Do all the commands now (after allocation), so that we
3048 * have consistent state if memory allocation failes
3049 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003050 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
3051
3052 /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3053 * stop the T2-shutdown timer,
3054 */
3055 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3056 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3057
3058 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3059 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
3060
Linus Torvalds1da177e2005-04-16 15:20:36 -07003061 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3062 SCTP_STATE(SCTP_STATE_CLOSED));
3063 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
3064 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3065 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
3066
3067 /* ...and remove all record of the association. */
3068 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
3069 return SCTP_DISPOSITION_DELETE_TCB;
3070
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07003071nomem_chunk:
3072 sctp_ulpevent_free(ev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003073nomem:
3074 return SCTP_DISPOSITION_NOMEM;
3075}
3076
3077/*
Jerome Forissier047a2422005-04-28 11:58:43 -07003078 * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41.
3079 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003080 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3081 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3082 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3083 * packet must fill in the Verification Tag field of the outbound
3084 * packet with the Verification Tag received in the SHUTDOWN ACK and
Jerome Forissier047a2422005-04-28 11:58:43 -07003085 * set the T-bit in the Chunk Flags to indicate that the Verification
3086 * Tag is reflected.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003087 *
3088 * 8) The receiver should respond to the sender of the OOTB packet with
3089 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3090 * MUST fill in the Verification Tag field of the outbound packet
3091 * with the value found in the Verification Tag field of the OOTB
Jerome Forissier047a2422005-04-28 11:58:43 -07003092 * packet and set the T-bit in the Chunk Flags to indicate that the
3093 * Verification Tag is reflected. After sending this ABORT, the
3094 * receiver of the OOTB packet shall discard the OOTB packet and take
3095 * no further action.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003096 */
3097sctp_disposition_t sctp_sf_ootb(const struct sctp_endpoint *ep,
3098 const struct sctp_association *asoc,
3099 const sctp_subtype_t type,
3100 void *arg,
3101 sctp_cmd_seq_t *commands)
3102{
3103 struct sctp_chunk *chunk = arg;
3104 struct sk_buff *skb = chunk->skb;
3105 sctp_chunkhdr_t *ch;
3106 __u8 *ch_end;
3107 int ootb_shut_ack = 0;
3108
3109 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES);
3110
3111 ch = (sctp_chunkhdr_t *) chunk->chunk_hdr;
3112 do {
3113 /* Break out if chunk length is less then minimal. */
3114 if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t))
3115 break;
3116
3117 ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
Tsutomu Fujiia7d1f1b2006-01-17 11:57:09 -08003118 if (ch_end > skb->tail)
3119 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003120
3121 if (SCTP_CID_SHUTDOWN_ACK == ch->type)
3122 ootb_shut_ack = 1;
3123
3124 /* RFC 2960, Section 3.3.7
3125 * Moreover, under any circumstances, an endpoint that
3126 * receives an ABORT MUST NOT respond to that ABORT by
3127 * sending an ABORT of its own.
3128 */
3129 if (SCTP_CID_ABORT == ch->type)
3130 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3131
3132 ch = (sctp_chunkhdr_t *) ch_end;
3133 } while (ch_end < skb->tail);
3134
3135 if (ootb_shut_ack)
3136 sctp_sf_shut_8_4_5(ep, asoc, type, arg, commands);
3137 else
3138 sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
3139
3140 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3141}
3142
3143/*
3144 * Handle an "Out of the blue" SHUTDOWN ACK.
3145 *
Jerome Forissier047a2422005-04-28 11:58:43 -07003146 * Section: 8.4 5, sctpimpguide 2.41.
3147 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003148 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
Jerome Forissier047a2422005-04-28 11:58:43 -07003149 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3150 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3151 * packet must fill in the Verification Tag field of the outbound
3152 * packet with the Verification Tag received in the SHUTDOWN ACK and
3153 * set the T-bit in the Chunk Flags to indicate that the Verification
3154 * Tag is reflected.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003155 *
3156 * Inputs
3157 * (endpoint, asoc, type, arg, commands)
3158 *
3159 * Outputs
3160 * (sctp_disposition_t)
3161 *
3162 * The return value is the disposition of the chunk.
3163 */
3164static sctp_disposition_t sctp_sf_shut_8_4_5(const struct sctp_endpoint *ep,
3165 const struct sctp_association *asoc,
3166 const sctp_subtype_t type,
3167 void *arg,
3168 sctp_cmd_seq_t *commands)
3169{
3170 struct sctp_packet *packet = NULL;
3171 struct sctp_chunk *chunk = arg;
3172 struct sctp_chunk *shut;
3173
3174 packet = sctp_ootb_pkt_new(asoc, chunk);
3175
3176 if (packet) {
3177 /* Make an SHUTDOWN_COMPLETE.
3178 * The T bit will be set if the asoc is NULL.
3179 */
3180 shut = sctp_make_shutdown_complete(asoc, chunk);
3181 if (!shut) {
3182 sctp_ootb_pkt_free(packet);
3183 return SCTP_DISPOSITION_NOMEM;
3184 }
3185
Jerome Forissier047a2422005-04-28 11:58:43 -07003186 /* Reflect vtag if T-Bit is set */
3187 if (sctp_test_T_bit(shut))
3188 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3189
Linus Torvalds1da177e2005-04-16 15:20:36 -07003190 /* Set the skb to the belonging sock for accounting. */
3191 shut->skb->sk = ep->base.sk;
3192
3193 sctp_packet_append_chunk(packet, shut);
3194
3195 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3196 SCTP_PACKET(packet));
3197
3198 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
3199
3200 /* If the chunk length is invalid, we don't want to process
3201 * the reset of the packet.
3202 */
3203 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3204 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3205
3206 return SCTP_DISPOSITION_CONSUME;
3207 }
3208
3209 return SCTP_DISPOSITION_NOMEM;
3210}
3211
3212/*
3213 * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state.
3214 *
3215 * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK
3216 * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the
3217 * procedures in section 8.4 SHOULD be followed, in other words it
3218 * should be treated as an Out Of The Blue packet.
3219 * [This means that we do NOT check the Verification Tag on these
3220 * chunks. --piggy ]
3221 *
3222 */
3223sctp_disposition_t sctp_sf_do_8_5_1_E_sa(const struct sctp_endpoint *ep,
3224 const struct sctp_association *asoc,
3225 const sctp_subtype_t type,
3226 void *arg,
3227 sctp_cmd_seq_t *commands)
3228{
3229 /* Although we do have an association in this case, it corresponds
3230 * to a restarted association. So the packet is treated as an OOTB
3231 * packet and the state function that handles OOTB SHUTDOWN_ACK is
3232 * called with a NULL association.
3233 */
3234 return sctp_sf_shut_8_4_5(ep, NULL, type, arg, commands);
3235}
3236
3237/* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */
3238sctp_disposition_t sctp_sf_do_asconf(const struct sctp_endpoint *ep,
3239 const struct sctp_association *asoc,
3240 const sctp_subtype_t type, void *arg,
3241 sctp_cmd_seq_t *commands)
3242{
3243 struct sctp_chunk *chunk = arg;
3244 struct sctp_chunk *asconf_ack = NULL;
3245 sctp_addiphdr_t *hdr;
3246 __u32 serial;
3247
3248 if (!sctp_vtag_verify(chunk, asoc)) {
3249 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3250 SCTP_NULL());
3251 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3252 }
3253
3254 /* Make sure that the ASCONF ADDIP chunk has a valid length. */
3255 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_addip_chunk_t)))
3256 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3257 commands);
3258
3259 hdr = (sctp_addiphdr_t *)chunk->skb->data;
3260 serial = ntohl(hdr->serial);
3261
3262 /* ADDIP 4.2 C1) Compare the value of the serial number to the value
3263 * the endpoint stored in a new association variable
3264 * 'Peer-Serial-Number'.
3265 */
3266 if (serial == asoc->peer.addip_serial + 1) {
3267 /* ADDIP 4.2 C2) If the value found in the serial number is
3268 * equal to the ('Peer-Serial-Number' + 1), the endpoint MUST
3269 * do V1-V5.
3270 */
3271 asconf_ack = sctp_process_asconf((struct sctp_association *)
3272 asoc, chunk);
3273 if (!asconf_ack)
3274 return SCTP_DISPOSITION_NOMEM;
3275 } else if (serial == asoc->peer.addip_serial) {
3276 /* ADDIP 4.2 C3) If the value found in the serial number is
3277 * equal to the value stored in the 'Peer-Serial-Number'
3278 * IMPLEMENTATION NOTE: As an optimization a receiver may wish
3279 * to save the last ASCONF-ACK for some predetermined period of
3280 * time and instead of re-processing the ASCONF (with the same
3281 * serial number) it may just re-transmit the ASCONF-ACK.
3282 */
3283 if (asoc->addip_last_asconf_ack)
3284 asconf_ack = asoc->addip_last_asconf_ack;
3285 else
3286 return SCTP_DISPOSITION_DISCARD;
3287 } else {
3288 /* ADDIP 4.2 C4) Otherwise, the ASCONF Chunk is discarded since
3289 * it must be either a stale packet or from an attacker.
3290 */
3291 return SCTP_DISPOSITION_DISCARD;
3292 }
3293
3294 /* ADDIP 4.2 C5) In both cases C2 and C3 the ASCONF-ACK MUST be sent
3295 * back to the source address contained in the IP header of the ASCONF
3296 * being responded to.
3297 */
3298 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(asconf_ack));
3299
3300 return SCTP_DISPOSITION_CONSUME;
3301}
3302
3303/*
3304 * ADDIP Section 4.3 General rules for address manipulation
3305 * When building TLV parameters for the ASCONF Chunk that will add or
3306 * delete IP addresses the D0 to D13 rules should be applied:
3307 */
3308sctp_disposition_t sctp_sf_do_asconf_ack(const struct sctp_endpoint *ep,
3309 const struct sctp_association *asoc,
3310 const sctp_subtype_t type, void *arg,
3311 sctp_cmd_seq_t *commands)
3312{
3313 struct sctp_chunk *asconf_ack = arg;
3314 struct sctp_chunk *last_asconf = asoc->addip_last_asconf;
3315 struct sctp_chunk *abort;
3316 sctp_addiphdr_t *addip_hdr;
3317 __u32 sent_serial, rcvd_serial;
3318
3319 if (!sctp_vtag_verify(asconf_ack, asoc)) {
3320 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3321 SCTP_NULL());
3322 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3323 }
3324
3325 /* Make sure that the ADDIP chunk has a valid length. */
3326 if (!sctp_chunk_length_valid(asconf_ack, sizeof(sctp_addip_chunk_t)))
3327 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3328 commands);
3329
3330 addip_hdr = (sctp_addiphdr_t *)asconf_ack->skb->data;
3331 rcvd_serial = ntohl(addip_hdr->serial);
3332
3333 if (last_asconf) {
3334 addip_hdr = (sctp_addiphdr_t *)last_asconf->subh.addip_hdr;
3335 sent_serial = ntohl(addip_hdr->serial);
3336 } else {
3337 sent_serial = asoc->addip_serial - 1;
3338 }
3339
3340 /* D0) If an endpoint receives an ASCONF-ACK that is greater than or
3341 * equal to the next serial number to be used but no ASCONF chunk is
3342 * outstanding the endpoint MUST ABORT the association. Note that a
3343 * sequence number is greater than if it is no more than 2^^31-1
3344 * larger than the current sequence number (using serial arithmetic).
3345 */
3346 if (ADDIP_SERIAL_gte(rcvd_serial, sent_serial + 1) &&
3347 !(asoc->addip_last_asconf)) {
3348 abort = sctp_make_abort(asoc, asconf_ack,
3349 sizeof(sctp_errhdr_t));
3350 if (abort) {
3351 sctp_init_cause(abort, SCTP_ERROR_ASCONF_ACK, NULL, 0);
3352 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3353 SCTP_CHUNK(abort));
3354 }
3355 /* We are going to ABORT, so we might as well stop
3356 * processing the rest of the chunks in the packet.
3357 */
3358 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3359 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3360 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07003361 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
3362 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003363 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08003364 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003365 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
3366 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3367 return SCTP_DISPOSITION_ABORT;
3368 }
3369
3370 if ((rcvd_serial == sent_serial) && asoc->addip_last_asconf) {
3371 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3372 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3373
3374 if (!sctp_process_asconf_ack((struct sctp_association *)asoc,
3375 asconf_ack))
3376 return SCTP_DISPOSITION_CONSUME;
3377
3378 abort = sctp_make_abort(asoc, asconf_ack,
3379 sizeof(sctp_errhdr_t));
3380 if (abort) {
3381 sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, NULL, 0);
3382 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3383 SCTP_CHUNK(abort));
3384 }
3385 /* We are going to ABORT, so we might as well stop
3386 * processing the rest of the chunks in the packet.
3387 */
3388 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07003389 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
3390 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003391 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08003392 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003393 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
3394 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3395 return SCTP_DISPOSITION_ABORT;
3396 }
3397
3398 return SCTP_DISPOSITION_DISCARD;
3399}
3400
3401/*
3402 * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP
3403 *
3404 * When a FORWARD TSN chunk arrives, the data receiver MUST first update
3405 * its cumulative TSN point to the value carried in the FORWARD TSN
3406 * chunk, and then MUST further advance its cumulative TSN point locally
3407 * if possible.
3408 * After the above processing, the data receiver MUST stop reporting any
3409 * missing TSNs earlier than or equal to the new cumulative TSN point.
3410 *
3411 * Verification Tag: 8.5 Verification Tag [Normal verification]
3412 *
3413 * The return value is the disposition of the chunk.
3414 */
3415sctp_disposition_t sctp_sf_eat_fwd_tsn(const struct sctp_endpoint *ep,
3416 const struct sctp_association *asoc,
3417 const sctp_subtype_t type,
3418 void *arg,
3419 sctp_cmd_seq_t *commands)
3420{
3421 struct sctp_chunk *chunk = arg;
3422 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
3423 __u16 len;
3424 __u32 tsn;
3425
3426 if (!sctp_vtag_verify(chunk, asoc)) {
3427 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3428 SCTP_NULL());
3429 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3430 }
3431
3432 /* Make sure that the FORWARD_TSN chunk has valid length. */
3433 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
3434 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3435 commands);
3436
3437 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3438 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3439 len = ntohs(chunk->chunk_hdr->length);
3440 len -= sizeof(struct sctp_chunkhdr);
3441 skb_pull(chunk->skb, len);
3442
3443 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
3444 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __FUNCTION__, tsn);
3445
3446 /* The TSN is too high--silently discard the chunk and count on it
3447 * getting retransmitted later.
3448 */
3449 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3450 goto discard_noforce;
3451
3452 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3453 if (len > sizeof(struct sctp_fwdtsn_hdr))
3454 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
3455 SCTP_CHUNK(chunk));
3456
3457 /* Count this as receiving DATA. */
3458 if (asoc->autoclose) {
3459 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3460 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
3461 }
3462
3463 /* FIXME: For now send a SACK, but DATA processing may
3464 * send another.
3465 */
3466 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
Linus Torvalds1da177e2005-04-16 15:20:36 -07003467
3468 return SCTP_DISPOSITION_CONSUME;
3469
3470discard_noforce:
3471 return SCTP_DISPOSITION_DISCARD;
3472}
3473
3474sctp_disposition_t sctp_sf_eat_fwd_tsn_fast(
3475 const struct sctp_endpoint *ep,
3476 const struct sctp_association *asoc,
3477 const sctp_subtype_t type,
3478 void *arg,
3479 sctp_cmd_seq_t *commands)
3480{
3481 struct sctp_chunk *chunk = arg;
3482 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
3483 __u16 len;
3484 __u32 tsn;
3485
3486 if (!sctp_vtag_verify(chunk, asoc)) {
3487 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3488 SCTP_NULL());
3489 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3490 }
3491
3492 /* Make sure that the FORWARD_TSN chunk has a valid length. */
3493 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
3494 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3495 commands);
3496
3497 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3498 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3499 len = ntohs(chunk->chunk_hdr->length);
3500 len -= sizeof(struct sctp_chunkhdr);
3501 skb_pull(chunk->skb, len);
3502
3503 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
3504 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __FUNCTION__, tsn);
3505
3506 /* The TSN is too high--silently discard the chunk and count on it
3507 * getting retransmitted later.
3508 */
3509 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3510 goto gen_shutdown;
3511
3512 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3513 if (len > sizeof(struct sctp_fwdtsn_hdr))
3514 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
3515 SCTP_CHUNK(chunk));
3516
3517 /* Go a head and force a SACK, since we are shutting down. */
3518gen_shutdown:
3519 /* Implementor's Guide.
3520 *
3521 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3522 * respond to each received packet containing one or more DATA chunk(s)
3523 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3524 */
3525 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
3526 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3527 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3528 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3529
3530 return SCTP_DISPOSITION_CONSUME;
3531}
3532
3533/*
3534 * Process an unknown chunk.
3535 *
3536 * Section: 3.2. Also, 2.1 in the implementor's guide.
3537 *
3538 * Chunk Types are encoded such that the highest-order two bits specify
3539 * the action that must be taken if the processing endpoint does not
3540 * recognize the Chunk Type.
3541 *
3542 * 00 - Stop processing this SCTP packet and discard it, do not process
3543 * any further chunks within it.
3544 *
3545 * 01 - Stop processing this SCTP packet and discard it, do not process
3546 * any further chunks within it, and report the unrecognized
3547 * chunk in an 'Unrecognized Chunk Type'.
3548 *
3549 * 10 - Skip this chunk and continue processing.
3550 *
3551 * 11 - Skip this chunk and continue processing, but report in an ERROR
3552 * Chunk using the 'Unrecognized Chunk Type' cause of error.
3553 *
3554 * The return value is the disposition of the chunk.
3555 */
3556sctp_disposition_t sctp_sf_unk_chunk(const struct sctp_endpoint *ep,
3557 const struct sctp_association *asoc,
3558 const sctp_subtype_t type,
3559 void *arg,
3560 sctp_cmd_seq_t *commands)
3561{
3562 struct sctp_chunk *unk_chunk = arg;
3563 struct sctp_chunk *err_chunk;
3564 sctp_chunkhdr_t *hdr;
3565
3566 SCTP_DEBUG_PRINTK("Processing the unknown chunk id %d.\n", type.chunk);
3567
3568 if (!sctp_vtag_verify(unk_chunk, asoc))
3569 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3570
3571 /* Make sure that the chunk has a valid length.
3572 * Since we don't know the chunk type, we use a general
3573 * chunkhdr structure to make a comparison.
3574 */
3575 if (!sctp_chunk_length_valid(unk_chunk, sizeof(sctp_chunkhdr_t)))
3576 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3577 commands);
3578
3579 switch (type.chunk & SCTP_CID_ACTION_MASK) {
3580 case SCTP_CID_ACTION_DISCARD:
3581 /* Discard the packet. */
3582 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3583 break;
3584 case SCTP_CID_ACTION_DISCARD_ERR:
3585 /* Discard the packet. */
3586 sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3587
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 return SCTP_DISPOSITION_CONSUME;
3598 break;
3599 case SCTP_CID_ACTION_SKIP:
3600 /* Skip the chunk. */
3601 return SCTP_DISPOSITION_DISCARD;
3602 break;
3603 case SCTP_CID_ACTION_SKIP_ERR:
3604 /* Generate an ERROR chunk as response. */
3605 hdr = unk_chunk->chunk_hdr;
3606 err_chunk = sctp_make_op_error(asoc, unk_chunk,
3607 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
3608 WORD_ROUND(ntohs(hdr->length)));
3609 if (err_chunk) {
3610 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3611 SCTP_CHUNK(err_chunk));
3612 }
3613 /* Skip the chunk. */
3614 return SCTP_DISPOSITION_CONSUME;
3615 break;
3616 default:
3617 break;
3618 }
3619
3620 return SCTP_DISPOSITION_DISCARD;
3621}
3622
3623/*
3624 * Discard the chunk.
3625 *
3626 * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2
3627 * [Too numerous to mention...]
3628 * Verification Tag: No verification needed.
3629 * Inputs
3630 * (endpoint, asoc, chunk)
3631 *
3632 * Outputs
3633 * (asoc, reply_msg, msg_up, timers, counters)
3634 *
3635 * The return value is the disposition of the chunk.
3636 */
3637sctp_disposition_t sctp_sf_discard_chunk(const struct sctp_endpoint *ep,
3638 const struct sctp_association *asoc,
3639 const sctp_subtype_t type,
3640 void *arg,
3641 sctp_cmd_seq_t *commands)
3642{
3643 SCTP_DEBUG_PRINTK("Chunk %d is discarded\n", type.chunk);
3644 return SCTP_DISPOSITION_DISCARD;
3645}
3646
3647/*
3648 * Discard the whole packet.
3649 *
3650 * Section: 8.4 2)
3651 *
3652 * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST
3653 * silently discard the OOTB packet and take no further action.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003654 *
3655 * Verification Tag: No verification necessary
3656 *
3657 * Inputs
3658 * (endpoint, asoc, chunk)
3659 *
3660 * Outputs
3661 * (asoc, reply_msg, msg_up, timers, counters)
3662 *
3663 * The return value is the disposition of the chunk.
3664 */
3665sctp_disposition_t sctp_sf_pdiscard(const struct sctp_endpoint *ep,
3666 const struct sctp_association *asoc,
3667 const sctp_subtype_t type,
3668 void *arg,
3669 sctp_cmd_seq_t *commands)
3670{
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07003671 SCTP_INC_STATS(SCTP_MIB_IN_PKT_DISCARDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003672 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
3673
3674 return SCTP_DISPOSITION_CONSUME;
3675}
3676
3677
3678/*
3679 * The other end is violating protocol.
3680 *
3681 * Section: Not specified
3682 * Verification Tag: Not specified
3683 * Inputs
3684 * (endpoint, asoc, chunk)
3685 *
3686 * Outputs
3687 * (asoc, reply_msg, msg_up, timers, counters)
3688 *
3689 * We simply tag the chunk as a violation. The state machine will log
3690 * the violation and continue.
3691 */
3692sctp_disposition_t sctp_sf_violation(const struct sctp_endpoint *ep,
3693 const struct sctp_association *asoc,
3694 const sctp_subtype_t type,
3695 void *arg,
3696 sctp_cmd_seq_t *commands)
3697{
3698 return SCTP_DISPOSITION_VIOLATION;
3699}
3700
3701
3702/*
3703 * Handle a protocol violation when the chunk length is invalid.
3704 * "Invalid" length is identified as smaller then the minimal length a
3705 * given chunk can be. For example, a SACK chunk has invalid length
3706 * if it's length is set to be smaller then the size of sctp_sack_chunk_t.
3707 *
3708 * We inform the other end by sending an ABORT with a Protocol Violation
3709 * error code.
3710 *
3711 * Section: Not specified
3712 * Verification Tag: Nothing to do
3713 * Inputs
3714 * (endpoint, asoc, chunk)
3715 *
3716 * Outputs
3717 * (reply_msg, msg_up, counters)
3718 *
3719 * Generate an ABORT chunk and terminate the association.
3720 */
Adrian Bunk52c1da32005-06-23 22:05:33 -07003721static sctp_disposition_t sctp_sf_violation_chunklen(
3722 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003723 const struct sctp_association *asoc,
3724 const sctp_subtype_t type,
3725 void *arg,
3726 sctp_cmd_seq_t *commands)
3727{
3728 struct sctp_chunk *chunk = arg;
3729 struct sctp_chunk *abort = NULL;
3730 char err_str[]="The following chunk had invalid length:";
3731
3732 /* Make the abort chunk. */
3733 abort = sctp_make_abort_violation(asoc, chunk, err_str,
3734 sizeof(err_str));
3735 if (!abort)
3736 goto nomem;
3737
3738 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
3739 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
3740
3741 if (asoc->state <= SCTP_STATE_COOKIE_ECHOED) {
3742 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3743 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07003744 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
3745 SCTP_ERROR(ECONNREFUSED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003746 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08003747 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003748 } else {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07003749 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
3750 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003751 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08003752 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003753 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3754 }
3755
3756 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
3757
3758 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
3759
3760 return SCTP_DISPOSITION_ABORT;
3761
3762nomem:
3763 return SCTP_DISPOSITION_NOMEM;
3764}
3765
3766/***************************************************************************
3767 * These are the state functions for handling primitive (Section 10) events.
3768 ***************************************************************************/
3769/*
3770 * sctp_sf_do_prm_asoc
3771 *
3772 * Section: 10.1 ULP-to-SCTP
3773 * B) Associate
3774 *
3775 * Format: ASSOCIATE(local SCTP instance name, destination transport addr,
3776 * outbound stream count)
3777 * -> association id [,destination transport addr list] [,outbound stream
3778 * count]
3779 *
3780 * This primitive allows the upper layer to initiate an association to a
3781 * specific peer endpoint.
3782 *
3783 * The peer endpoint shall be specified by one of the transport addresses
3784 * which defines the endpoint (see Section 1.4). If the local SCTP
3785 * instance has not been initialized, the ASSOCIATE is considered an
3786 * error.
3787 * [This is not relevant for the kernel implementation since we do all
3788 * initialization at boot time. It we hadn't initialized we wouldn't
3789 * get anywhere near this code.]
3790 *
3791 * An association id, which is a local handle to the SCTP association,
3792 * will be returned on successful establishment of the association. If
3793 * SCTP is not able to open an SCTP association with the peer endpoint,
3794 * an error is returned.
3795 * [In the kernel implementation, the struct sctp_association needs to
3796 * be created BEFORE causing this primitive to run.]
3797 *
3798 * Other association parameters may be returned, including the
3799 * complete destination transport addresses of the peer as well as the
3800 * outbound stream count of the local endpoint. One of the transport
3801 * address from the returned destination addresses will be selected by
3802 * the local endpoint as default primary path for sending SCTP packets
3803 * to this peer. The returned "destination transport addr list" can
3804 * be used by the ULP to change the default primary path or to force
3805 * sending a packet to a specific transport address. [All of this
3806 * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING
3807 * function.]
3808 *
3809 * Mandatory attributes:
3810 *
3811 * o local SCTP instance name - obtained from the INITIALIZE operation.
3812 * [This is the argument asoc.]
3813 * o destination transport addr - specified as one of the transport
3814 * addresses of the peer endpoint with which the association is to be
3815 * established.
3816 * [This is asoc->peer.active_path.]
3817 * o outbound stream count - the number of outbound streams the ULP
3818 * would like to open towards this peer endpoint.
3819 * [BUG: This is not currently implemented.]
3820 * Optional attributes:
3821 *
3822 * None.
3823 *
3824 * The return value is a disposition.
3825 */
3826sctp_disposition_t sctp_sf_do_prm_asoc(const struct sctp_endpoint *ep,
3827 const struct sctp_association *asoc,
3828 const sctp_subtype_t type,
3829 void *arg,
3830 sctp_cmd_seq_t *commands)
3831{
3832 struct sctp_chunk *repl;
3833
3834 /* The comment below says that we enter COOKIE-WAIT AFTER
3835 * sending the INIT, but that doesn't actually work in our
3836 * implementation...
3837 */
3838 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3839 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
3840
3841 /* RFC 2960 5.1 Normal Establishment of an Association
3842 *
3843 * A) "A" first sends an INIT chunk to "Z". In the INIT, "A"
3844 * must provide its Verification Tag (Tag_A) in the Initiate
3845 * Tag field. Tag_A SHOULD be a random number in the range of
3846 * 1 to 4294967295 (see 5.3.1 for Tag value selection). ...
3847 */
3848
3849 repl = sctp_make_init(asoc, &asoc->base.bind_addr, GFP_ATOMIC, 0);
3850 if (!repl)
3851 goto nomem;
3852
3853 /* Cast away the const modifier, as we want to just
3854 * rerun it through as a sideffect.
3855 */
3856 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC,
3857 SCTP_ASOC((struct sctp_association *) asoc));
3858
Frank Filz3f7a87d2005-06-20 13:14:57 -07003859 /* Choose transport for INIT. */
3860 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
3861 SCTP_CHUNK(repl));
3862
Linus Torvalds1da177e2005-04-16 15:20:36 -07003863 /* After sending the INIT, "A" starts the T1-init timer and
3864 * enters the COOKIE-WAIT state.
3865 */
3866 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
3867 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
3868 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
3869 return SCTP_DISPOSITION_CONSUME;
3870
3871nomem:
3872 return SCTP_DISPOSITION_NOMEM;
3873}
3874
3875/*
3876 * Process the SEND primitive.
3877 *
3878 * Section: 10.1 ULP-to-SCTP
3879 * E) Send
3880 *
3881 * Format: SEND(association id, buffer address, byte count [,context]
3882 * [,stream id] [,life time] [,destination transport address]
3883 * [,unorder flag] [,no-bundle flag] [,payload protocol-id] )
3884 * -> result
3885 *
3886 * This is the main method to send user data via SCTP.
3887 *
3888 * Mandatory attributes:
3889 *
3890 * o association id - local handle to the SCTP association
3891 *
3892 * o buffer address - the location where the user message to be
3893 * transmitted is stored;
3894 *
3895 * o byte count - The size of the user data in number of bytes;
3896 *
3897 * Optional attributes:
3898 *
3899 * o context - an optional 32 bit integer that will be carried in the
3900 * sending failure notification to the ULP if the transportation of
3901 * this User Message fails.
3902 *
3903 * o stream id - to indicate which stream to send the data on. If not
3904 * specified, stream 0 will be used.
3905 *
3906 * o life time - specifies the life time of the user data. The user data
3907 * will not be sent by SCTP after the life time expires. This
3908 * parameter can be used to avoid efforts to transmit stale
3909 * user messages. SCTP notifies the ULP if the data cannot be
3910 * initiated to transport (i.e. sent to the destination via SCTP's
3911 * send primitive) within the life time variable. However, the
3912 * user data will be transmitted if SCTP has attempted to transmit a
3913 * chunk before the life time expired.
3914 *
3915 * o destination transport address - specified as one of the destination
3916 * transport addresses of the peer endpoint to which this packet
3917 * should be sent. Whenever possible, SCTP should use this destination
3918 * transport address for sending the packets, instead of the current
3919 * primary path.
3920 *
3921 * o unorder flag - this flag, if present, indicates that the user
3922 * would like the data delivered in an unordered fashion to the peer
3923 * (i.e., the U flag is set to 1 on all DATA chunks carrying this
3924 * message).
3925 *
3926 * o no-bundle flag - instructs SCTP not to bundle this user data with
3927 * other outbound DATA chunks. SCTP MAY still bundle even when
3928 * this flag is present, when faced with network congestion.
3929 *
3930 * o payload protocol-id - A 32 bit unsigned integer that is to be
3931 * passed to the peer indicating the type of payload protocol data
3932 * being transmitted. This value is passed as opaque data by SCTP.
3933 *
3934 * The return value is the disposition.
3935 */
3936sctp_disposition_t sctp_sf_do_prm_send(const struct sctp_endpoint *ep,
3937 const struct sctp_association *asoc,
3938 const sctp_subtype_t type,
3939 void *arg,
3940 sctp_cmd_seq_t *commands)
3941{
3942 struct sctp_chunk *chunk = arg;
3943
3944 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
3945 return SCTP_DISPOSITION_CONSUME;
3946}
3947
3948/*
3949 * Process the SHUTDOWN primitive.
3950 *
3951 * Section: 10.1:
3952 * C) Shutdown
3953 *
3954 * Format: SHUTDOWN(association id)
3955 * -> result
3956 *
3957 * Gracefully closes an association. Any locally queued user data
3958 * will be delivered to the peer. The association will be terminated only
3959 * after the peer acknowledges all the SCTP packets sent. A success code
3960 * will be returned on successful termination of the association. If
3961 * attempting to terminate the association results in a failure, an error
3962 * code shall be returned.
3963 *
3964 * Mandatory attributes:
3965 *
3966 * o association id - local handle to the SCTP association
3967 *
3968 * Optional attributes:
3969 *
3970 * None.
3971 *
3972 * The return value is the disposition.
3973 */
3974sctp_disposition_t sctp_sf_do_9_2_prm_shutdown(
3975 const struct sctp_endpoint *ep,
3976 const struct sctp_association *asoc,
3977 const sctp_subtype_t type,
3978 void *arg,
3979 sctp_cmd_seq_t *commands)
3980{
3981 int disposition;
3982
3983 /* From 9.2 Shutdown of an Association
3984 * Upon receipt of the SHUTDOWN primitive from its upper
3985 * layer, the endpoint enters SHUTDOWN-PENDING state and
3986 * remains there until all outstanding data has been
3987 * acknowledged by its peer. The endpoint accepts no new data
3988 * from its upper layer, but retransmits data to the far end
3989 * if necessary to fill gaps.
3990 */
3991 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3992 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
3993
3994 /* sctpimpguide-05 Section 2.12.2
3995 * The sender of the SHUTDOWN MAY also start an overall guard timer
3996 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
3997 */
3998 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
3999 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4000
4001 disposition = SCTP_DISPOSITION_CONSUME;
4002 if (sctp_outq_is_empty(&asoc->outqueue)) {
4003 disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type,
4004 arg, commands);
4005 }
4006 return disposition;
4007}
4008
4009/*
4010 * Process the ABORT primitive.
4011 *
4012 * Section: 10.1:
4013 * C) Abort
4014 *
4015 * Format: Abort(association id [, cause code])
4016 * -> result
4017 *
4018 * Ungracefully closes an association. Any locally queued user data
4019 * will be discarded and an ABORT chunk is sent to the peer. A success code
4020 * will be returned on successful abortion of the association. If
4021 * attempting to abort the association results in a failure, an error
4022 * code shall be returned.
4023 *
4024 * Mandatory attributes:
4025 *
4026 * o association id - local handle to the SCTP association
4027 *
4028 * Optional attributes:
4029 *
4030 * o cause code - reason of the abort to be passed to the peer
4031 *
4032 * None.
4033 *
4034 * The return value is the disposition.
4035 */
4036sctp_disposition_t sctp_sf_do_9_1_prm_abort(
4037 const struct sctp_endpoint *ep,
4038 const struct sctp_association *asoc,
4039 const sctp_subtype_t type,
4040 void *arg,
4041 sctp_cmd_seq_t *commands)
4042{
4043 /* From 9.1 Abort of an Association
4044 * Upon receipt of the ABORT primitive from its upper
4045 * layer, the endpoint enters CLOSED state and
4046 * discard all outstanding data has been
4047 * acknowledged by its peer. The endpoint accepts no new data
4048 * from its upper layer, but retransmits data to the far end
4049 * if necessary to fill gaps.
4050 */
Sridhar Samudralac164a9b2006-08-22 11:50:39 -07004051 struct sctp_chunk *abort = arg;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004052 sctp_disposition_t retval;
4053
4054 retval = SCTP_DISPOSITION_CONSUME;
4055
Sridhar Samudralac164a9b2006-08-22 11:50:39 -07004056 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004057
4058 /* Even if we can't send the ABORT due to low memory delete the
4059 * TCB. This is a departure from our typical NOMEM handling.
4060 */
4061
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004062 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4063 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004064 /* Delete the established association. */
4065 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08004066 SCTP_PERR(SCTP_ERROR_USER_ABORT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004067
4068 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4069 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
4070
4071 return retval;
4072}
4073
4074/* We tried an illegal operation on an association which is closed. */
4075sctp_disposition_t sctp_sf_error_closed(const struct sctp_endpoint *ep,
4076 const struct sctp_association *asoc,
4077 const sctp_subtype_t type,
4078 void *arg,
4079 sctp_cmd_seq_t *commands)
4080{
4081 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, SCTP_ERROR(-EINVAL));
4082 return SCTP_DISPOSITION_CONSUME;
4083}
4084
4085/* We tried an illegal operation on an association which is shutting
4086 * down.
4087 */
4088sctp_disposition_t sctp_sf_error_shutdown(const struct sctp_endpoint *ep,
4089 const struct sctp_association *asoc,
4090 const sctp_subtype_t type,
4091 void *arg,
4092 sctp_cmd_seq_t *commands)
4093{
4094 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR,
4095 SCTP_ERROR(-ESHUTDOWN));
4096 return SCTP_DISPOSITION_CONSUME;
4097}
4098
4099/*
4100 * sctp_cookie_wait_prm_shutdown
4101 *
4102 * Section: 4 Note: 2
4103 * Verification Tag:
4104 * Inputs
4105 * (endpoint, asoc)
4106 *
4107 * The RFC does not explicitly address this issue, but is the route through the
4108 * state table when someone issues a shutdown while in COOKIE_WAIT state.
4109 *
4110 * Outputs
4111 * (timers)
4112 */
4113sctp_disposition_t sctp_sf_cookie_wait_prm_shutdown(
4114 const struct sctp_endpoint *ep,
4115 const struct sctp_association *asoc,
4116 const sctp_subtype_t type,
4117 void *arg,
4118 sctp_cmd_seq_t *commands)
4119{
4120 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4121 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4122
4123 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4124 SCTP_STATE(SCTP_STATE_CLOSED));
4125
4126 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
4127
4128 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
4129
4130 return SCTP_DISPOSITION_DELETE_TCB;
4131}
4132
4133/*
4134 * sctp_cookie_echoed_prm_shutdown
4135 *
4136 * Section: 4 Note: 2
4137 * Verification Tag:
4138 * Inputs
4139 * (endpoint, asoc)
4140 *
4141 * The RFC does not explcitly address this issue, but is the route through the
4142 * state table when someone issues a shutdown while in COOKIE_ECHOED state.
4143 *
4144 * Outputs
4145 * (timers)
4146 */
4147sctp_disposition_t sctp_sf_cookie_echoed_prm_shutdown(
4148 const struct sctp_endpoint *ep,
4149 const struct sctp_association *asoc,
4150 const sctp_subtype_t type,
4151 void *arg, sctp_cmd_seq_t *commands)
4152{
4153 /* There is a single T1 timer, so we should be able to use
4154 * common function with the COOKIE-WAIT state.
4155 */
4156 return sctp_sf_cookie_wait_prm_shutdown(ep, asoc, type, arg, commands);
4157}
4158
4159/*
4160 * sctp_sf_cookie_wait_prm_abort
4161 *
4162 * Section: 4 Note: 2
4163 * Verification Tag:
4164 * Inputs
4165 * (endpoint, asoc)
4166 *
4167 * The RFC does not explicitly address this issue, but is the route through the
4168 * state table when someone issues an abort while in COOKIE_WAIT state.
4169 *
4170 * Outputs
4171 * (timers)
4172 */
4173sctp_disposition_t sctp_sf_cookie_wait_prm_abort(
4174 const struct sctp_endpoint *ep,
4175 const struct sctp_association *asoc,
4176 const sctp_subtype_t type,
4177 void *arg,
4178 sctp_cmd_seq_t *commands)
4179{
Sridhar Samudralac164a9b2006-08-22 11:50:39 -07004180 struct sctp_chunk *abort = arg;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004181 sctp_disposition_t retval;
4182
4183 /* Stop T1-init timer */
4184 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4185 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4186 retval = SCTP_DISPOSITION_CONSUME;
4187
Sridhar Samudralac164a9b2006-08-22 11:50:39 -07004188 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004189
4190 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4191 SCTP_STATE(SCTP_STATE_CLOSED));
4192
4193 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4194
4195 /* Even if we can't send the ABORT due to low memory delete the
4196 * TCB. This is a departure from our typical NOMEM handling.
4197 */
4198
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004199 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4200 SCTP_ERROR(ECONNREFUSED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004201 /* Delete the established association. */
4202 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08004203 SCTP_PERR(SCTP_ERROR_USER_ABORT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004204
4205 return retval;
4206}
4207
4208/*
4209 * sctp_sf_cookie_echoed_prm_abort
4210 *
4211 * Section: 4 Note: 3
4212 * Verification Tag:
4213 * Inputs
4214 * (endpoint, asoc)
4215 *
4216 * The RFC does not explcitly address this issue, but is the route through the
4217 * state table when someone issues an abort while in COOKIE_ECHOED state.
4218 *
4219 * Outputs
4220 * (timers)
4221 */
4222sctp_disposition_t sctp_sf_cookie_echoed_prm_abort(
4223 const struct sctp_endpoint *ep,
4224 const struct sctp_association *asoc,
4225 const sctp_subtype_t type,
4226 void *arg,
4227 sctp_cmd_seq_t *commands)
4228{
4229 /* There is a single T1 timer, so we should be able to use
4230 * common function with the COOKIE-WAIT state.
4231 */
4232 return sctp_sf_cookie_wait_prm_abort(ep, asoc, type, arg, commands);
4233}
4234
4235/*
4236 * sctp_sf_shutdown_pending_prm_abort
4237 *
4238 * Inputs
4239 * (endpoint, asoc)
4240 *
4241 * The RFC does not explicitly address this issue, but is the route through the
4242 * state table when someone issues an abort while in SHUTDOWN-PENDING state.
4243 *
4244 * Outputs
4245 * (timers)
4246 */
4247sctp_disposition_t sctp_sf_shutdown_pending_prm_abort(
4248 const struct sctp_endpoint *ep,
4249 const struct sctp_association *asoc,
4250 const sctp_subtype_t type,
4251 void *arg,
4252 sctp_cmd_seq_t *commands)
4253{
4254 /* Stop the T5-shutdown guard timer. */
4255 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4256 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4257
4258 return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands);
4259}
4260
4261/*
4262 * sctp_sf_shutdown_sent_prm_abort
4263 *
4264 * Inputs
4265 * (endpoint, asoc)
4266 *
4267 * The RFC does not explicitly address this issue, but is the route through the
4268 * state table when someone issues an abort while in SHUTDOWN-SENT state.
4269 *
4270 * Outputs
4271 * (timers)
4272 */
4273sctp_disposition_t sctp_sf_shutdown_sent_prm_abort(
4274 const struct sctp_endpoint *ep,
4275 const struct sctp_association *asoc,
4276 const sctp_subtype_t type,
4277 void *arg,
4278 sctp_cmd_seq_t *commands)
4279{
4280 /* Stop the T2-shutdown timer. */
4281 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4282 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4283
4284 /* Stop the T5-shutdown guard timer. */
4285 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4286 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4287
4288 return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands);
4289}
4290
4291/*
4292 * sctp_sf_cookie_echoed_prm_abort
4293 *
4294 * Inputs
4295 * (endpoint, asoc)
4296 *
4297 * The RFC does not explcitly address this issue, but is the route through the
4298 * state table when someone issues an abort while in COOKIE_ECHOED state.
4299 *
4300 * Outputs
4301 * (timers)
4302 */
4303sctp_disposition_t sctp_sf_shutdown_ack_sent_prm_abort(
4304 const struct sctp_endpoint *ep,
4305 const struct sctp_association *asoc,
4306 const sctp_subtype_t type,
4307 void *arg,
4308 sctp_cmd_seq_t *commands)
4309{
4310 /* The same T2 timer, so we should be able to use
4311 * common function with the SHUTDOWN-SENT state.
4312 */
4313 return sctp_sf_shutdown_sent_prm_abort(ep, asoc, type, arg, commands);
4314}
4315
4316/*
4317 * Process the REQUESTHEARTBEAT primitive
4318 *
4319 * 10.1 ULP-to-SCTP
4320 * J) Request Heartbeat
4321 *
4322 * Format: REQUESTHEARTBEAT(association id, destination transport address)
4323 *
4324 * -> result
4325 *
4326 * Instructs the local endpoint to perform a HeartBeat on the specified
4327 * destination transport address of the given association. The returned
4328 * result should indicate whether the transmission of the HEARTBEAT
4329 * chunk to the destination address is successful.
4330 *
4331 * Mandatory attributes:
4332 *
4333 * o association id - local handle to the SCTP association
4334 *
4335 * o destination transport address - the transport address of the
4336 * association on which a heartbeat should be issued.
4337 */
4338sctp_disposition_t sctp_sf_do_prm_requestheartbeat(
4339 const struct sctp_endpoint *ep,
4340 const struct sctp_association *asoc,
4341 const sctp_subtype_t type,
4342 void *arg,
4343 sctp_cmd_seq_t *commands)
4344{
4345 return sctp_sf_heartbeat(ep, asoc, type, (struct sctp_transport *)arg,
4346 commands);
4347}
4348
4349/*
4350 * ADDIP Section 4.1 ASCONF Chunk Procedures
4351 * When an endpoint has an ASCONF signaled change to be sent to the
4352 * remote endpoint it should do A1 to A9
4353 */
4354sctp_disposition_t sctp_sf_do_prm_asconf(const struct sctp_endpoint *ep,
4355 const struct sctp_association *asoc,
4356 const sctp_subtype_t type,
4357 void *arg,
4358 sctp_cmd_seq_t *commands)
4359{
4360 struct sctp_chunk *chunk = arg;
4361
4362 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
4363 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4364 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
4365 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
4366 return SCTP_DISPOSITION_CONSUME;
4367}
4368
4369/*
4370 * Ignore the primitive event
4371 *
4372 * The return value is the disposition of the primitive.
4373 */
4374sctp_disposition_t sctp_sf_ignore_primitive(
4375 const struct sctp_endpoint *ep,
4376 const struct sctp_association *asoc,
4377 const sctp_subtype_t type,
4378 void *arg,
4379 sctp_cmd_seq_t *commands)
4380{
4381 SCTP_DEBUG_PRINTK("Primitive type %d is ignored.\n", type.primitive);
4382 return SCTP_DISPOSITION_DISCARD;
4383}
4384
4385/***************************************************************************
4386 * These are the state functions for the OTHER events.
4387 ***************************************************************************/
4388
4389/*
4390 * Start the shutdown negotiation.
4391 *
4392 * From Section 9.2:
4393 * Once all its outstanding data has been acknowledged, the endpoint
4394 * shall send a SHUTDOWN chunk to its peer including in the Cumulative
4395 * TSN Ack field the last sequential TSN it has received from the peer.
4396 * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT
4397 * state. If the timer expires, the endpoint must re-send the SHUTDOWN
4398 * with the updated last sequential TSN received from its peer.
4399 *
4400 * The return value is the disposition.
4401 */
4402sctp_disposition_t sctp_sf_do_9_2_start_shutdown(
4403 const struct sctp_endpoint *ep,
4404 const struct sctp_association *asoc,
4405 const sctp_subtype_t type,
4406 void *arg,
4407 sctp_cmd_seq_t *commands)
4408{
4409 struct sctp_chunk *reply;
4410
4411 /* Once all its outstanding data has been acknowledged, the
4412 * endpoint shall send a SHUTDOWN chunk to its peer including
4413 * in the Cumulative TSN Ack field the last sequential TSN it
4414 * has received from the peer.
4415 */
4416 reply = sctp_make_shutdown(asoc, NULL);
4417 if (!reply)
4418 goto nomem;
4419
4420 /* Set the transport for the SHUTDOWN chunk and the timeout for the
4421 * T2-shutdown timer.
4422 */
4423 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
4424
4425 /* It shall then start the T2-shutdown timer */
4426 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4427 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4428
4429 if (asoc->autoclose)
4430 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4431 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
4432
4433 /* and enter the SHUTDOWN-SENT state. */
4434 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4435 SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT));
4436
4437 /* sctp-implguide 2.10 Issues with Heartbeating and failover
4438 *
4439 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
4440 * or SHUTDOWN-ACK.
4441 */
4442 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
4443
4444 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
4445
4446 return SCTP_DISPOSITION_CONSUME;
4447
4448nomem:
4449 return SCTP_DISPOSITION_NOMEM;
4450}
4451
4452/*
4453 * Generate a SHUTDOWN ACK now that everything is SACK'd.
4454 *
4455 * From Section 9.2:
4456 *
4457 * If it has no more outstanding DATA chunks, the SHUTDOWN receiver
4458 * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own,
4459 * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the
4460 * endpoint must re-send the SHUTDOWN ACK.
4461 *
4462 * The return value is the disposition.
4463 */
4464sctp_disposition_t sctp_sf_do_9_2_shutdown_ack(
4465 const struct sctp_endpoint *ep,
4466 const struct sctp_association *asoc,
4467 const sctp_subtype_t type,
4468 void *arg,
4469 sctp_cmd_seq_t *commands)
4470{
4471 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
4472 struct sctp_chunk *reply;
4473
4474 /* There are 2 ways of getting here:
4475 * 1) called in response to a SHUTDOWN chunk
4476 * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued.
4477 *
4478 * For the case (2), the arg parameter is set to NULL. We need
4479 * to check that we have a chunk before accessing it's fields.
4480 */
4481 if (chunk) {
4482 if (!sctp_vtag_verify(chunk, asoc))
4483 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
4484
4485 /* Make sure that the SHUTDOWN chunk has a valid length. */
4486 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_shutdown_chunk_t)))
4487 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
4488 commands);
4489 }
4490
4491 /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
4492 * shall send a SHUTDOWN ACK ...
4493 */
4494 reply = sctp_make_shutdown_ack(asoc, chunk);
4495 if (!reply)
4496 goto nomem;
4497
4498 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
4499 * the T2-shutdown timer.
4500 */
4501 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
4502
4503 /* and start/restart a T2-shutdown timer of its own, */
4504 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
4505 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4506
4507 if (asoc->autoclose)
4508 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4509 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
4510
4511 /* Enter the SHUTDOWN-ACK-SENT state. */
4512 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4513 SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT));
4514
4515 /* sctp-implguide 2.10 Issues with Heartbeating and failover
4516 *
4517 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
4518 * or SHUTDOWN-ACK.
4519 */
4520 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
4521
4522 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
4523
4524 return SCTP_DISPOSITION_CONSUME;
4525
4526nomem:
4527 return SCTP_DISPOSITION_NOMEM;
4528}
4529
4530/*
4531 * Ignore the event defined as other
4532 *
4533 * The return value is the disposition of the event.
4534 */
4535sctp_disposition_t sctp_sf_ignore_other(const struct sctp_endpoint *ep,
4536 const struct sctp_association *asoc,
4537 const sctp_subtype_t type,
4538 void *arg,
4539 sctp_cmd_seq_t *commands)
4540{
4541 SCTP_DEBUG_PRINTK("The event other type %d is ignored\n", type.other);
4542 return SCTP_DISPOSITION_DISCARD;
4543}
4544
4545/************************************************************
4546 * These are the state functions for handling timeout events.
4547 ************************************************************/
4548
4549/*
4550 * RTX Timeout
4551 *
4552 * Section: 6.3.3 Handle T3-rtx Expiration
4553 *
4554 * Whenever the retransmission timer T3-rtx expires for a destination
4555 * address, do the following:
4556 * [See below]
4557 *
4558 * The return value is the disposition of the chunk.
4559 */
4560sctp_disposition_t sctp_sf_do_6_3_3_rtx(const struct sctp_endpoint *ep,
4561 const struct sctp_association *asoc,
4562 const sctp_subtype_t type,
4563 void *arg,
4564 sctp_cmd_seq_t *commands)
4565{
4566 struct sctp_transport *transport = arg;
4567
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07004568 SCTP_INC_STATS(SCTP_MIB_T3_RTX_EXPIREDS);
4569
Linus Torvalds1da177e2005-04-16 15:20:36 -07004570 if (asoc->overall_error_count >= asoc->max_retrans) {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004571 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4572 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004573 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
4574 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08004575 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004576 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4577 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
4578 return SCTP_DISPOSITION_DELETE_TCB;
4579 }
4580
4581 /* E1) For the destination address for which the timer
4582 * expires, adjust its ssthresh with rules defined in Section
4583 * 7.2.3 and set the cwnd <- MTU.
4584 */
4585
4586 /* E2) For the destination address for which the timer
4587 * expires, set RTO <- RTO * 2 ("back off the timer"). The
4588 * maximum value discussed in rule C7 above (RTO.max) may be
4589 * used to provide an upper bound to this doubling operation.
4590 */
4591
4592 /* E3) Determine how many of the earliest (i.e., lowest TSN)
4593 * outstanding DATA chunks for the address for which the
4594 * T3-rtx has expired will fit into a single packet, subject
4595 * to the MTU constraint for the path corresponding to the
4596 * destination transport address to which the retransmission
4597 * is being sent (this may be different from the address for
4598 * which the timer expires [see Section 6.4]). Call this
4599 * value K. Bundle and retransmit those K DATA chunks in a
4600 * single packet to the destination endpoint.
4601 *
4602 * Note: Any DATA chunks that were sent to the address for
4603 * which the T3-rtx timer expired but did not fit in one MTU
4604 * (rule E3 above), should be marked for retransmission and
4605 * sent as soon as cwnd allows (normally when a SACK arrives).
4606 */
4607
4608 /* NB: Rules E4 and F1 are implicit in R1. */
4609 sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN, SCTP_TRANSPORT(transport));
4610
4611 /* Do some failure management (Section 8.2). */
4612 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
4613
4614 return SCTP_DISPOSITION_CONSUME;
4615}
4616
4617/*
4618 * Generate delayed SACK on timeout
4619 *
4620 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
4621 *
4622 * The guidelines on delayed acknowledgement algorithm specified in
4623 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
4624 * acknowledgement SHOULD be generated for at least every second packet
4625 * (not every second DATA chunk) received, and SHOULD be generated
4626 * within 200 ms of the arrival of any unacknowledged DATA chunk. In
4627 * some situations it may be beneficial for an SCTP transmitter to be
4628 * more conservative than the algorithms detailed in this document
4629 * allow. However, an SCTP transmitter MUST NOT be more aggressive than
4630 * the following algorithms allow.
4631 */
4632sctp_disposition_t sctp_sf_do_6_2_sack(const struct sctp_endpoint *ep,
4633 const struct sctp_association *asoc,
4634 const sctp_subtype_t type,
4635 void *arg,
4636 sctp_cmd_seq_t *commands)
4637{
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07004638 SCTP_INC_STATS(SCTP_MIB_DELAY_SACK_EXPIREDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004639 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
4640 return SCTP_DISPOSITION_CONSUME;
4641}
4642
4643/*
Frank Filz3f7a87d2005-06-20 13:14:57 -07004644 * sctp_sf_t1_init_timer_expire
Linus Torvalds1da177e2005-04-16 15:20:36 -07004645 *
4646 * Section: 4 Note: 2
4647 * Verification Tag:
4648 * Inputs
4649 * (endpoint, asoc)
4650 *
4651 * RFC 2960 Section 4 Notes
4652 * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT
4653 * and re-start the T1-init timer without changing state. This MUST
4654 * be repeated up to 'Max.Init.Retransmits' times. After that, the
4655 * endpoint MUST abort the initialization process and report the
4656 * error to SCTP user.
4657 *
Frank Filz3f7a87d2005-06-20 13:14:57 -07004658 * Outputs
4659 * (timers, events)
4660 *
4661 */
4662sctp_disposition_t sctp_sf_t1_init_timer_expire(const struct sctp_endpoint *ep,
4663 const struct sctp_association *asoc,
4664 const sctp_subtype_t type,
4665 void *arg,
4666 sctp_cmd_seq_t *commands)
4667{
4668 struct sctp_chunk *repl = NULL;
4669 struct sctp_bind_addr *bp;
4670 int attempts = asoc->init_err_counter + 1;
4671
4672 SCTP_DEBUG_PRINTK("Timer T1 expired (INIT).\n");
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07004673 SCTP_INC_STATS(SCTP_MIB_T1_INIT_EXPIREDS);
Frank Filz3f7a87d2005-06-20 13:14:57 -07004674
Vlad Yasevich81845c22006-01-30 15:59:54 -08004675 if (attempts <= asoc->max_init_attempts) {
Frank Filz3f7a87d2005-06-20 13:14:57 -07004676 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
4677 repl = sctp_make_init(asoc, bp, GFP_ATOMIC, 0);
4678 if (!repl)
4679 return SCTP_DISPOSITION_NOMEM;
4680
4681 /* Choose transport for INIT. */
4682 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
4683 SCTP_CHUNK(repl));
4684
4685 /* Issue a sideeffect to do the needed accounting. */
4686 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_RESTART,
4687 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4688
4689 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
4690 } else {
4691 SCTP_DEBUG_PRINTK("Giving up on INIT, attempts: %d"
4692 " max_init_attempts: %d\n",
4693 attempts, asoc->max_init_attempts);
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004694 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4695 SCTP_ERROR(ETIMEDOUT));
Frank Filz3f7a87d2005-06-20 13:14:57 -07004696 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08004697 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Frank Filz3f7a87d2005-06-20 13:14:57 -07004698 return SCTP_DISPOSITION_DELETE_TCB;
4699 }
4700
4701 return SCTP_DISPOSITION_CONSUME;
4702}
4703
4704/*
4705 * sctp_sf_t1_cookie_timer_expire
4706 *
4707 * Section: 4 Note: 2
4708 * Verification Tag:
4709 * Inputs
4710 * (endpoint, asoc)
4711 *
4712 * RFC 2960 Section 4 Notes
4713 * 3) If the T1-cookie timer expires, the endpoint MUST retransmit
Linus Torvalds1da177e2005-04-16 15:20:36 -07004714 * COOKIE ECHO and re-start the T1-cookie timer without changing
4715 * state. This MUST be repeated up to 'Max.Init.Retransmits' times.
4716 * After that, the endpoint MUST abort the initialization process and
4717 * report the error to SCTP user.
4718 *
4719 * Outputs
4720 * (timers, events)
4721 *
4722 */
Frank Filz3f7a87d2005-06-20 13:14:57 -07004723sctp_disposition_t sctp_sf_t1_cookie_timer_expire(const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07004724 const struct sctp_association *asoc,
4725 const sctp_subtype_t type,
4726 void *arg,
4727 sctp_cmd_seq_t *commands)
4728{
Frank Filz3f7a87d2005-06-20 13:14:57 -07004729 struct sctp_chunk *repl = NULL;
4730 int attempts = asoc->init_err_counter + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004731
Frank Filz3f7a87d2005-06-20 13:14:57 -07004732 SCTP_DEBUG_PRINTK("Timer T1 expired (COOKIE-ECHO).\n");
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07004733 SCTP_INC_STATS(SCTP_MIB_T1_COOKIE_EXPIREDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004734
Vlad Yasevich81845c22006-01-30 15:59:54 -08004735 if (attempts <= asoc->max_init_attempts) {
Frank Filz3f7a87d2005-06-20 13:14:57 -07004736 repl = sctp_make_cookie_echo(asoc, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004737 if (!repl)
Frank Filz3f7a87d2005-06-20 13:14:57 -07004738 return SCTP_DISPOSITION_NOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004739
4740 /* Issue a sideeffect to do the needed accounting. */
Frank Filz3f7a87d2005-06-20 13:14:57 -07004741 sctp_add_cmd_sf(commands, SCTP_CMD_COOKIEECHO_RESTART,
4742 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
4743
Linus Torvalds1da177e2005-04-16 15:20:36 -07004744 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
4745 } else {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004746 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4747 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004748 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08004749 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004750 return SCTP_DISPOSITION_DELETE_TCB;
4751 }
4752
4753 return SCTP_DISPOSITION_CONSUME;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004754}
4755
4756/* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN
4757 * with the updated last sequential TSN received from its peer.
4758 *
4759 * An endpoint should limit the number of retransmissions of the
4760 * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'.
4761 * If this threshold is exceeded the endpoint should destroy the TCB and
4762 * MUST report the peer endpoint unreachable to the upper layer (and
4763 * thus the association enters the CLOSED state). The reception of any
4764 * packet from its peer (i.e. as the peer sends all of its queued DATA
4765 * chunks) should clear the endpoint's retransmission count and restart
4766 * the T2-Shutdown timer, giving its peer ample opportunity to transmit
4767 * all of its queued DATA chunks that have not yet been sent.
4768 */
4769sctp_disposition_t sctp_sf_t2_timer_expire(const struct sctp_endpoint *ep,
4770 const struct sctp_association *asoc,
4771 const sctp_subtype_t type,
4772 void *arg,
4773 sctp_cmd_seq_t *commands)
4774{
4775 struct sctp_chunk *reply = NULL;
4776
4777 SCTP_DEBUG_PRINTK("Timer T2 expired.\n");
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07004778 SCTP_INC_STATS(SCTP_MIB_T2_SHUTDOWN_EXPIREDS);
4779
Linus Torvalds1da177e2005-04-16 15:20:36 -07004780 if (asoc->overall_error_count >= asoc->max_retrans) {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004781 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4782 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004783 /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
4784 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08004785 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004786 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4787 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
4788 return SCTP_DISPOSITION_DELETE_TCB;
4789 }
4790
4791 switch (asoc->state) {
4792 case SCTP_STATE_SHUTDOWN_SENT:
4793 reply = sctp_make_shutdown(asoc, NULL);
4794 break;
4795
4796 case SCTP_STATE_SHUTDOWN_ACK_SENT:
4797 reply = sctp_make_shutdown_ack(asoc, NULL);
4798 break;
4799
4800 default:
4801 BUG();
4802 break;
4803 };
4804
4805 if (!reply)
4806 goto nomem;
4807
4808 /* Do some failure management (Section 8.2). */
4809 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
4810 SCTP_TRANSPORT(asoc->shutdown_last_sent_to));
4811
4812 /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for
4813 * the T2-shutdown timer.
4814 */
4815 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
4816
4817 /* Restart the T2-shutdown timer. */
4818 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
4819 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4820 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
4821 return SCTP_DISPOSITION_CONSUME;
4822
4823nomem:
4824 return SCTP_DISPOSITION_NOMEM;
4825}
4826
4827/*
4828 * ADDIP Section 4.1 ASCONF CHunk Procedures
4829 * If the T4 RTO timer expires the endpoint should do B1 to B5
4830 */
4831sctp_disposition_t sctp_sf_t4_timer_expire(
4832 const struct sctp_endpoint *ep,
4833 const struct sctp_association *asoc,
4834 const sctp_subtype_t type,
4835 void *arg,
4836 sctp_cmd_seq_t *commands)
4837{
4838 struct sctp_chunk *chunk = asoc->addip_last_asconf;
4839 struct sctp_transport *transport = chunk->transport;
4840
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07004841 SCTP_INC_STATS(SCTP_MIB_T4_RTO_EXPIREDS);
4842
Linus Torvalds1da177e2005-04-16 15:20:36 -07004843 /* ADDIP 4.1 B1) Increment the error counters and perform path failure
4844 * detection on the appropriate destination address as defined in
4845 * RFC2960 [5] section 8.1 and 8.2.
4846 */
4847 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
4848
4849 /* Reconfig T4 timer and transport. */
4850 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
4851
4852 /* ADDIP 4.1 B2) Increment the association error counters and perform
4853 * endpoint failure detection on the association as defined in
4854 * RFC2960 [5] section 8.1 and 8.2.
4855 * association error counter is incremented in SCTP_CMD_STRIKE.
4856 */
4857 if (asoc->overall_error_count >= asoc->max_retrans) {
4858 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4859 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004860 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4861 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004862 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08004863 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004864 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4865 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
4866 return SCTP_DISPOSITION_ABORT;
4867 }
4868
4869 /* ADDIP 4.1 B3) Back-off the destination address RTO value to which
4870 * the ASCONF chunk was sent by doubling the RTO timer value.
4871 * This is done in SCTP_CMD_STRIKE.
4872 */
4873
4874 /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible
4875 * choose an alternate destination address (please refer to RFC2960
4876 * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this
4877 * chunk, it MUST be the same (including its serial number) as the last
4878 * ASCONF sent.
4879 */
4880 sctp_chunk_hold(asoc->addip_last_asconf);
4881 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4882 SCTP_CHUNK(asoc->addip_last_asconf));
4883
4884 /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different
4885 * destination is selected, then the RTO used will be that of the new
4886 * destination address.
4887 */
4888 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
4889 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
4890
4891 return SCTP_DISPOSITION_CONSUME;
4892}
4893
4894/* sctpimpguide-05 Section 2.12.2
4895 * The sender of the SHUTDOWN MAY also start an overall guard timer
4896 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
4897 * At the expiration of this timer the sender SHOULD abort the association
4898 * by sending an ABORT chunk.
4899 */
4900sctp_disposition_t sctp_sf_t5_timer_expire(const struct sctp_endpoint *ep,
4901 const struct sctp_association *asoc,
4902 const sctp_subtype_t type,
4903 void *arg,
4904 sctp_cmd_seq_t *commands)
4905{
4906 struct sctp_chunk *reply = NULL;
4907
4908 SCTP_DEBUG_PRINTK("Timer T5 expired.\n");
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07004909 SCTP_INC_STATS(SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004910
4911 reply = sctp_make_abort(asoc, NULL, 0);
4912 if (!reply)
4913 goto nomem;
4914
4915 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004916 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4917 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004918 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08004919 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004920
4921 return SCTP_DISPOSITION_DELETE_TCB;
4922nomem:
4923 return SCTP_DISPOSITION_NOMEM;
4924}
4925
4926/* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires,
4927 * the association is automatically closed by starting the shutdown process.
4928 * The work that needs to be done is same as when SHUTDOWN is initiated by
4929 * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown().
4930 */
4931sctp_disposition_t sctp_sf_autoclose_timer_expire(
4932 const struct sctp_endpoint *ep,
4933 const struct sctp_association *asoc,
4934 const sctp_subtype_t type,
4935 void *arg,
4936 sctp_cmd_seq_t *commands)
4937{
4938 int disposition;
4939
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07004940 SCTP_INC_STATS(SCTP_MIB_AUTOCLOSE_EXPIREDS);
4941
Linus Torvalds1da177e2005-04-16 15:20:36 -07004942 /* From 9.2 Shutdown of an Association
4943 * Upon receipt of the SHUTDOWN primitive from its upper
4944 * layer, the endpoint enters SHUTDOWN-PENDING state and
4945 * remains there until all outstanding data has been
4946 * acknowledged by its peer. The endpoint accepts no new data
4947 * from its upper layer, but retransmits data to the far end
4948 * if necessary to fill gaps.
4949 */
4950 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4951 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
4952
4953 /* sctpimpguide-05 Section 2.12.2
4954 * The sender of the SHUTDOWN MAY also start an overall guard timer
4955 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
4956 */
4957 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4958 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4959 disposition = SCTP_DISPOSITION_CONSUME;
4960 if (sctp_outq_is_empty(&asoc->outqueue)) {
4961 disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type,
4962 arg, commands);
4963 }
4964 return disposition;
4965}
4966
4967/*****************************************************************************
4968 * These are sa state functions which could apply to all types of events.
4969 ****************************************************************************/
4970
4971/*
4972 * This table entry is not implemented.
4973 *
4974 * Inputs
4975 * (endpoint, asoc, chunk)
4976 *
4977 * The return value is the disposition of the chunk.
4978 */
4979sctp_disposition_t sctp_sf_not_impl(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_NOT_IMPL;
4986}
4987
4988/*
4989 * This table entry represents a bug.
4990 *
4991 * Inputs
4992 * (endpoint, asoc, chunk)
4993 *
4994 * The return value is the disposition of the chunk.
4995 */
4996sctp_disposition_t sctp_sf_bug(const struct sctp_endpoint *ep,
4997 const struct sctp_association *asoc,
4998 const sctp_subtype_t type,
4999 void *arg,
5000 sctp_cmd_seq_t *commands)
5001{
5002 return SCTP_DISPOSITION_BUG;
5003}
5004
5005/*
5006 * This table entry represents the firing of a timer in the wrong state.
5007 * Since timer deletion cannot be guaranteed a timer 'may' end up firing
5008 * when the association is in the wrong state. This event should
5009 * be ignored, so as to prevent any rearming of the timer.
5010 *
5011 * Inputs
5012 * (endpoint, asoc, chunk)
5013 *
5014 * The return value is the disposition of the chunk.
5015 */
5016sctp_disposition_t sctp_sf_timer_ignore(const struct sctp_endpoint *ep,
5017 const struct sctp_association *asoc,
5018 const sctp_subtype_t type,
5019 void *arg,
5020 sctp_cmd_seq_t *commands)
5021{
5022 SCTP_DEBUG_PRINTK("Timer %d ignored.\n", type.chunk);
5023 return SCTP_DISPOSITION_CONSUME;
5024}
5025
5026/********************************************************************
5027 * 2nd Level Abstractions
5028 ********************************************************************/
5029
5030/* Pull the SACK chunk based on the SACK header. */
5031static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk)
5032{
5033 struct sctp_sackhdr *sack;
5034 unsigned int len;
5035 __u16 num_blocks;
5036 __u16 num_dup_tsns;
5037
5038 /* Protect ourselves from reading too far into
5039 * the skb from a bogus sender.
5040 */
5041 sack = (struct sctp_sackhdr *) chunk->skb->data;
5042
5043 num_blocks = ntohs(sack->num_gap_ack_blocks);
5044 num_dup_tsns = ntohs(sack->num_dup_tsns);
5045 len = sizeof(struct sctp_sackhdr);
5046 len += (num_blocks + num_dup_tsns) * sizeof(__u32);
5047 if (len > chunk->skb->len)
5048 return NULL;
5049
5050 skb_pull(chunk->skb, len);
5051
5052 return sack;
5053}
5054
5055/* Create an ABORT packet to be sent as a response, with the specified
5056 * error causes.
5057 */
5058static struct sctp_packet *sctp_abort_pkt_new(const struct sctp_endpoint *ep,
5059 const struct sctp_association *asoc,
5060 struct sctp_chunk *chunk,
5061 const void *payload,
5062 size_t paylen)
5063{
5064 struct sctp_packet *packet;
5065 struct sctp_chunk *abort;
5066
5067 packet = sctp_ootb_pkt_new(asoc, chunk);
5068
5069 if (packet) {
5070 /* Make an ABORT.
5071 * The T bit will be set if the asoc is NULL.
5072 */
5073 abort = sctp_make_abort(asoc, chunk, paylen);
5074 if (!abort) {
5075 sctp_ootb_pkt_free(packet);
5076 return NULL;
5077 }
Jerome Forissier047a2422005-04-28 11:58:43 -07005078
5079 /* Reflect vtag if T-Bit is set */
5080 if (sctp_test_T_bit(abort))
5081 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
5082
Linus Torvalds1da177e2005-04-16 15:20:36 -07005083 /* Add specified error causes, i.e., payload, to the
5084 * end of the chunk.
5085 */
5086 sctp_addto_chunk(abort, paylen, payload);
5087
5088 /* Set the skb to the belonging sock for accounting. */
5089 abort->skb->sk = ep->base.sk;
5090
5091 sctp_packet_append_chunk(packet, abort);
5092
5093 }
5094
5095 return packet;
5096}
5097
5098/* Allocate a packet for responding in the OOTB conditions. */
5099static struct sctp_packet *sctp_ootb_pkt_new(const struct sctp_association *asoc,
5100 const struct sctp_chunk *chunk)
5101{
5102 struct sctp_packet *packet;
5103 struct sctp_transport *transport;
5104 __u16 sport;
5105 __u16 dport;
5106 __u32 vtag;
5107
5108 /* Get the source and destination port from the inbound packet. */
5109 sport = ntohs(chunk->sctp_hdr->dest);
5110 dport = ntohs(chunk->sctp_hdr->source);
5111
5112 /* The V-tag is going to be the same as the inbound packet if no
5113 * association exists, otherwise, use the peer's vtag.
5114 */
5115 if (asoc) {
5116 vtag = asoc->peer.i.init_tag;
5117 } else {
5118 /* Special case the INIT and stale COOKIE_ECHO as there is no
5119 * vtag yet.
5120 */
5121 switch(chunk->chunk_hdr->type) {
5122 case SCTP_CID_INIT:
5123 {
5124 sctp_init_chunk_t *init;
5125
5126 init = (sctp_init_chunk_t *)chunk->chunk_hdr;
5127 vtag = ntohl(init->init_hdr.init_tag);
5128 break;
5129 }
5130 default:
5131 vtag = ntohl(chunk->sctp_hdr->vtag);
5132 break;
5133 }
5134 }
5135
5136 /* Make a transport for the bucket, Eliza... */
Al Viro6a1e5f32006-11-20 17:12:25 -08005137 transport = sctp_transport_new(sctp_source(chunk), GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005138 if (!transport)
5139 goto nomem;
5140
5141 /* Cache a route for the transport with the chunk's destination as
5142 * the source address.
5143 */
Al Viro16b0a032006-11-20 17:13:38 -08005144 sctp_transport_route(transport, (union sctp_addr *)&chunk->dest,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005145 sctp_sk(sctp_get_ctl_sock()));
5146
5147 packet = sctp_packet_init(&transport->packet, transport, sport, dport);
5148 packet = sctp_packet_config(packet, vtag, 0);
5149
5150 return packet;
5151
5152nomem:
5153 return NULL;
5154}
5155
5156/* Free the packet allocated earlier for responding in the OOTB condition. */
5157void sctp_ootb_pkt_free(struct sctp_packet *packet)
5158{
5159 sctp_transport_free(packet->transport);
5160}
5161
5162/* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */
5163static void sctp_send_stale_cookie_err(const struct sctp_endpoint *ep,
5164 const struct sctp_association *asoc,
5165 const struct sctp_chunk *chunk,
5166 sctp_cmd_seq_t *commands,
5167 struct sctp_chunk *err_chunk)
5168{
5169 struct sctp_packet *packet;
5170
5171 if (err_chunk) {
5172 packet = sctp_ootb_pkt_new(asoc, chunk);
5173 if (packet) {
5174 struct sctp_signed_cookie *cookie;
5175
5176 /* Override the OOTB vtag from the cookie. */
5177 cookie = chunk->subh.cookie_hdr;
5178 packet->vtag = cookie->c.peer_vtag;
5179
5180 /* Set the skb to the belonging sock for accounting. */
5181 err_chunk->skb->sk = ep->base.sk;
5182 sctp_packet_append_chunk(packet, err_chunk);
5183 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
5184 SCTP_PACKET(packet));
5185 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
5186 } else
5187 sctp_chunk_free (err_chunk);
5188 }
5189}
5190
5191
5192/* Process a data chunk */
5193static int sctp_eat_data(const struct sctp_association *asoc,
5194 struct sctp_chunk *chunk,
5195 sctp_cmd_seq_t *commands)
5196{
5197 sctp_datahdr_t *data_hdr;
5198 struct sctp_chunk *err;
5199 size_t datalen;
5200 sctp_verb_t deliver;
5201 int tmp;
5202 __u32 tsn;
Neil Horman049b3ff2005-11-11 16:08:24 -08005203 int account_value;
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005204 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
Neil Horman049b3ff2005-11-11 16:08:24 -08005205 struct sock *sk = asoc->base.sk;
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005206 int rcvbuf_over = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005207
5208 data_hdr = chunk->subh.data_hdr = (sctp_datahdr_t *)chunk->skb->data;
5209 skb_pull(chunk->skb, sizeof(sctp_datahdr_t));
5210
5211 tsn = ntohl(data_hdr->tsn);
5212 SCTP_DEBUG_PRINTK("eat_data: TSN 0x%x.\n", tsn);
5213
5214 /* ASSERT: Now skb->data is really the user data. */
5215
Neil Horman049b3ff2005-11-11 16:08:24 -08005216 /*
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005217 * If we are established, and we have used up our receive buffer
5218 * memory, think about droping the frame.
5219 * Note that we have an opportunity to improve performance here.
5220 * If we accept one chunk from an skbuff, we have to keep all the
5221 * memory of that skbuff around until the chunk is read into user
5222 * space. Therefore, once we accept 1 chunk we may as well accept all
5223 * remaining chunks in the skbuff. The data_accepted flag helps us do
5224 * that.
Neil Horman049b3ff2005-11-11 16:08:24 -08005225 */
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005226 if ((asoc->state == SCTP_STATE_ESTABLISHED) && (!chunk->data_accepted)) {
Neil Horman049b3ff2005-11-11 16:08:24 -08005227 /*
5228 * If the receive buffer policy is 1, then each
5229 * association can allocate up to sk_rcvbuf bytes
5230 * otherwise, all the associations in aggregate
5231 * may allocate up to sk_rcvbuf bytes
5232 */
5233 if (asoc->ep->rcvbuf_policy)
5234 account_value = atomic_read(&asoc->rmem_alloc);
5235 else
5236 account_value = atomic_read(&sk->sk_rmem_alloc);
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005237 if (account_value > sk->sk_rcvbuf) {
5238 /*
5239 * We need to make forward progress, even when we are
5240 * under memory pressure, so we always allow the
5241 * next tsn after the ctsn ack point to be accepted.
5242 * This lets us avoid deadlocks in which we have to
5243 * drop frames that would otherwise let us drain the
5244 * receive queue.
5245 */
5246 if ((sctp_tsnmap_get_ctsn(map) + 1) != tsn)
5247 return SCTP_IERROR_IGNORE_TSN;
Neil Horman049b3ff2005-11-11 16:08:24 -08005248
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005249 /*
5250 * We're going to accept the frame but we should renege
5251 * to make space for it. This will send us down that
5252 * path later in this function.
5253 */
5254 rcvbuf_over = 1;
5255 }
Neil Horman049b3ff2005-11-11 16:08:24 -08005256 }
5257
Linus Torvalds1da177e2005-04-16 15:20:36 -07005258 /* Process ECN based congestion.
5259 *
5260 * Since the chunk structure is reused for all chunks within
5261 * a packet, we use ecn_ce_done to track if we've already
5262 * done CE processing for this packet.
5263 *
5264 * We need to do ECN processing even if we plan to discard the
5265 * chunk later.
5266 */
5267
5268 if (!chunk->ecn_ce_done) {
5269 struct sctp_af *af;
5270 chunk->ecn_ce_done = 1;
5271
5272 af = sctp_get_af_specific(
5273 ipver2af(chunk->skb->nh.iph->version));
5274
5275 if (af && af->is_ce(chunk->skb) && asoc->peer.ecn_capable) {
5276 /* Do real work as sideffect. */
5277 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_CE,
5278 SCTP_U32(tsn));
5279 }
5280 }
5281
5282 tmp = sctp_tsnmap_check(&asoc->peer.tsn_map, tsn);
5283 if (tmp < 0) {
5284 /* The TSN is too high--silently discard the chunk and
5285 * count on it getting retransmitted later.
5286 */
5287 return SCTP_IERROR_HIGH_TSN;
5288 } else if (tmp > 0) {
5289 /* This is a duplicate. Record it. */
5290 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_DUP, SCTP_U32(tsn));
5291 return SCTP_IERROR_DUP_TSN;
5292 }
5293
5294 /* This is a new TSN. */
5295
5296 /* Discard if there is no room in the receive window.
5297 * Actually, allow a little bit of overflow (up to a MTU).
5298 */
5299 datalen = ntohs(chunk->chunk_hdr->length);
5300 datalen -= sizeof(sctp_data_chunk_t);
5301
5302 deliver = SCTP_CMD_CHUNK_ULP;
5303
5304 /* Think about partial delivery. */
5305 if ((datalen >= asoc->rwnd) && (!asoc->ulpq.pd_mode)) {
5306
5307 /* Even if we don't accept this chunk there is
5308 * memory pressure.
5309 */
5310 sctp_add_cmd_sf(commands, SCTP_CMD_PART_DELIVER, SCTP_NULL());
5311 }
5312
5313 /* Spill over rwnd a little bit. Note: While allowed, this spill over
5314 * seems a bit troublesome in that frag_point varies based on
5315 * PMTU. In cases, such as loopback, this might be a rather
5316 * large spill over.
Neil Hormand5b9f4c2006-06-17 22:59:03 -07005317 * NOTE: If we have a full receive buffer here, we only renege if
5318 * our receiver can still make progress without the tsn being
5319 * received. We do this because in the event that the associations
5320 * receive queue is empty we are filling a leading gap, and since
5321 * reneging moves the gap to the end of the tsn stream, we are likely
5322 * to stall again very shortly. Avoiding the renege when we fill a
5323 * leading gap is a good heuristic for avoiding such steady state
5324 * stalls.
Linus Torvalds1da177e2005-04-16 15:20:36 -07005325 */
5326 if (!asoc->rwnd || asoc->rwnd_over ||
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005327 (datalen > asoc->rwnd + asoc->frag_point) ||
Neil Hormand5b9f4c2006-06-17 22:59:03 -07005328 (rcvbuf_over && (!skb_queue_len(&sk->sk_receive_queue)))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07005329
5330 /* If this is the next TSN, consider reneging to make
5331 * room. Note: Playing nice with a confused sender. A
5332 * malicious sender can still eat up all our buffer
5333 * space and in the future we may want to detect and
5334 * do more drastic reneging.
5335 */
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005336 if (sctp_tsnmap_has_gap(map) &&
5337 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07005338 SCTP_DEBUG_PRINTK("Reneging for tsn:%u\n", tsn);
5339 deliver = SCTP_CMD_RENEGE;
5340 } else {
5341 SCTP_DEBUG_PRINTK("Discard tsn: %u len: %Zd, "
5342 "rwnd: %d\n", tsn, datalen,
5343 asoc->rwnd);
5344 return SCTP_IERROR_IGNORE_TSN;
5345 }
5346 }
5347
5348 /*
5349 * Section 3.3.10.9 No User Data (9)
5350 *
5351 * Cause of error
5352 * ---------------
5353 * No User Data: This error cause is returned to the originator of a
5354 * DATA chunk if a received DATA chunk has no user data.
5355 */
5356 if (unlikely(0 == datalen)) {
5357 err = sctp_make_abort_no_data(asoc, chunk, tsn);
5358 if (err) {
5359 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
5360 SCTP_CHUNK(err));
5361 }
5362 /* We are going to ABORT, so we might as well stop
5363 * processing the rest of the chunks in the packet.
5364 */
5365 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07005366 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5367 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005368 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08005369 SCTP_PERR(SCTP_ERROR_NO_DATA));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005370 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
5371 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
5372 return SCTP_IERROR_NO_DATA;
5373 }
5374
5375 /* If definately accepting the DATA chunk, record its TSN, otherwise
5376 * wait for renege processing.
5377 */
5378 if (SCTP_CMD_CHUNK_ULP == deliver)
5379 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_TSN, SCTP_U32(tsn));
5380
Sridhar Samudrala9faa7302006-07-21 14:49:07 -07005381 chunk->data_accepted = 1;
5382
Linus Torvalds1da177e2005-04-16 15:20:36 -07005383 /* Note: Some chunks may get overcounted (if we drop) or overcounted
5384 * if we renege and the chunk arrives again.
5385 */
5386 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
5387 SCTP_INC_STATS(SCTP_MIB_INUNORDERCHUNKS);
5388 else
5389 SCTP_INC_STATS(SCTP_MIB_INORDERCHUNKS);
5390
5391 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
5392 *
5393 * If an endpoint receive a DATA chunk with an invalid stream
5394 * identifier, it shall acknowledge the reception of the DATA chunk
5395 * following the normal procedure, immediately send an ERROR chunk
5396 * with cause set to "Invalid Stream Identifier" (See Section 3.3.10)
5397 * and discard the DATA chunk.
5398 */
5399 if (ntohs(data_hdr->stream) >= asoc->c.sinit_max_instreams) {
5400 err = sctp_make_op_error(asoc, chunk, SCTP_ERROR_INV_STRM,
5401 &data_hdr->stream,
5402 sizeof(data_hdr->stream));
5403 if (err)
5404 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
5405 SCTP_CHUNK(err));
5406 return SCTP_IERROR_BAD_STREAM;
5407 }
5408
5409 /* Send the data up to the user. Note: Schedule the
5410 * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK
5411 * chunk needs the updated rwnd.
5412 */
5413 sctp_add_cmd_sf(commands, deliver, SCTP_CHUNK(chunk));
5414
5415 return SCTP_IERROR_NO_ERROR;
5416}