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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 Viro09ef7fe2006-11-20 17:04:10 -08001182 sctp_sf_send_restart_abort(&new_addr->ipaddr_h, 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 */
2161 stale = ntohl(*(suseconds_t *)((u8 *)err + sizeof(sctp_errhdr_t)));
2162 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,
2469 SCTP_U32(chunk->subh.shutdown_hdr->cum_tsn_ack));
2470
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;
2548
2549 if (!sctp_vtag_verify(chunk, asoc))
2550 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2551
2552 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2553 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2554 commands);
2555
2556 cwr = (sctp_cwrhdr_t *) chunk->skb->data;
2557 skb_pull(chunk->skb, sizeof(sctp_cwrhdr_t));
2558
2559 cwr->lowest_tsn = ntohl(cwr->lowest_tsn);
2560
2561 /* Does this CWR ack the last sent congestion notification? */
2562 if (TSN_lte(asoc->last_ecne_tsn, cwr->lowest_tsn)) {
2563 /* Stop sending ECNE. */
2564 sctp_add_cmd_sf(commands,
2565 SCTP_CMD_ECN_CWR,
2566 SCTP_U32(cwr->lowest_tsn));
2567 }
2568 return SCTP_DISPOSITION_CONSUME;
2569}
2570
2571/*
2572 * sctp_sf_do_ecne
2573 *
2574 * Section: Appendix A: Explicit Congestion Notification
2575 *
2576 * ECN-Echo
2577 *
2578 * RFC 2481 details a specific bit for a receiver to send back in its
2579 * TCP acknowledgements to notify the sender of the Congestion
2580 * Experienced (CE) bit having arrived from the network. For SCTP this
2581 * same indication is made by including the ECNE chunk. This chunk
2582 * contains one data element, i.e. the lowest TSN associated with the IP
2583 * datagram marked with the CE bit.....
2584 *
2585 * Verification Tag: 8.5 Verification Tag [Normal verification]
2586 * Inputs
2587 * (endpoint, asoc, chunk)
2588 *
2589 * Outputs
2590 * (asoc, reply_msg, msg_up, timers, counters)
2591 *
2592 * The return value is the disposition of the chunk.
2593 */
2594sctp_disposition_t sctp_sf_do_ecne(const struct sctp_endpoint *ep,
2595 const struct sctp_association *asoc,
2596 const sctp_subtype_t type,
2597 void *arg,
2598 sctp_cmd_seq_t *commands)
2599{
2600 sctp_ecnehdr_t *ecne;
2601 struct sctp_chunk *chunk = arg;
2602
2603 if (!sctp_vtag_verify(chunk, asoc))
2604 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2605
2606 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2607 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2608 commands);
2609
2610 ecne = (sctp_ecnehdr_t *) chunk->skb->data;
2611 skb_pull(chunk->skb, sizeof(sctp_ecnehdr_t));
2612
2613 /* If this is a newer ECNE than the last CWR packet we sent out */
2614 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_ECNE,
2615 SCTP_U32(ntohl(ecne->lowest_tsn)));
2616
2617 return SCTP_DISPOSITION_CONSUME;
2618}
2619
2620/*
2621 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
2622 *
2623 * The SCTP endpoint MUST always acknowledge the reception of each valid
2624 * DATA chunk.
2625 *
2626 * The guidelines on delayed acknowledgement algorithm specified in
2627 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
2628 * acknowledgement SHOULD be generated for at least every second packet
2629 * (not every second DATA chunk) received, and SHOULD be generated within
2630 * 200 ms of the arrival of any unacknowledged DATA chunk. In some
2631 * situations it may be beneficial for an SCTP transmitter to be more
2632 * conservative than the algorithms detailed in this document allow.
2633 * However, an SCTP transmitter MUST NOT be more aggressive than the
2634 * following algorithms allow.
2635 *
2636 * A SCTP receiver MUST NOT generate more than one SACK for every
2637 * incoming packet, other than to update the offered window as the
2638 * receiving application consumes new data.
2639 *
2640 * Verification Tag: 8.5 Verification Tag [Normal verification]
2641 *
2642 * Inputs
2643 * (endpoint, asoc, chunk)
2644 *
2645 * Outputs
2646 * (asoc, reply_msg, msg_up, timers, counters)
2647 *
2648 * The return value is the disposition of the chunk.
2649 */
2650sctp_disposition_t sctp_sf_eat_data_6_2(const struct sctp_endpoint *ep,
2651 const struct sctp_association *asoc,
2652 const sctp_subtype_t type,
2653 void *arg,
2654 sctp_cmd_seq_t *commands)
2655{
2656 struct sctp_chunk *chunk = arg;
2657 int error;
2658
2659 if (!sctp_vtag_verify(chunk, asoc)) {
2660 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
2661 SCTP_NULL());
2662 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2663 }
2664
2665 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
2666 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2667 commands);
2668
2669 error = sctp_eat_data(asoc, chunk, commands );
2670 switch (error) {
2671 case SCTP_IERROR_NO_ERROR:
2672 break;
2673 case SCTP_IERROR_HIGH_TSN:
2674 case SCTP_IERROR_BAD_STREAM:
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07002675 SCTP_INC_STATS(SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002676 goto discard_noforce;
2677 case SCTP_IERROR_DUP_TSN:
2678 case SCTP_IERROR_IGNORE_TSN:
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07002679 SCTP_INC_STATS(SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002680 goto discard_force;
2681 case SCTP_IERROR_NO_DATA:
2682 goto consume;
2683 default:
2684 BUG();
2685 }
2686
2687 if (asoc->autoclose) {
2688 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2689 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
2690 }
2691
2692 /* If this is the last chunk in a packet, we need to count it
2693 * toward sack generation. Note that we need to SACK every
2694 * OTHER packet containing data chunks, EVEN IF WE DISCARD
2695 * THEM. We elect to NOT generate SACK's if the chunk fails
2696 * the verification tag test.
2697 *
2698 * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2699 *
2700 * The SCTP endpoint MUST always acknowledge the reception of
2701 * each valid DATA chunk.
2702 *
2703 * The guidelines on delayed acknowledgement algorithm
2704 * specified in Section 4.2 of [RFC2581] SHOULD be followed.
2705 * Specifically, an acknowledgement SHOULD be generated for at
2706 * least every second packet (not every second DATA chunk)
2707 * received, and SHOULD be generated within 200 ms of the
2708 * arrival of any unacknowledged DATA chunk. In some
2709 * situations it may be beneficial for an SCTP transmitter to
2710 * be more conservative than the algorithms detailed in this
2711 * document allow. However, an SCTP transmitter MUST NOT be
2712 * more aggressive than the following algorithms allow.
2713 */
Frank Filz52ccb8e2005-12-22 11:36:46 -08002714 if (chunk->end_of_packet)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002715 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
2716
Linus Torvalds1da177e2005-04-16 15:20:36 -07002717 return SCTP_DISPOSITION_CONSUME;
2718
2719discard_force:
2720 /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2721 *
2722 * When a packet arrives with duplicate DATA chunk(s) and with
2723 * no new DATA chunk(s), the endpoint MUST immediately send a
2724 * SACK with no delay. If a packet arrives with duplicate
2725 * DATA chunk(s) bundled with new DATA chunks, the endpoint
2726 * MAY immediately send a SACK. Normally receipt of duplicate
2727 * DATA chunks will occur when the original SACK chunk was lost
2728 * and the peer's RTO has expired. The duplicate TSN number(s)
2729 * SHOULD be reported in the SACK as duplicate.
2730 */
2731 /* In our case, we split the MAY SACK advice up whether or not
2732 * the last chunk is a duplicate.'
2733 */
2734 if (chunk->end_of_packet)
2735 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
2736 return SCTP_DISPOSITION_DISCARD;
2737
2738discard_noforce:
Frank Filz52ccb8e2005-12-22 11:36:46 -08002739 if (chunk->end_of_packet)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002740 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
2741
Linus Torvalds1da177e2005-04-16 15:20:36 -07002742 return SCTP_DISPOSITION_DISCARD;
2743consume:
2744 return SCTP_DISPOSITION_CONSUME;
2745
2746}
2747
2748/*
2749 * sctp_sf_eat_data_fast_4_4
2750 *
2751 * Section: 4 (4)
2752 * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received
2753 * DATA chunks without delay.
2754 *
2755 * Verification Tag: 8.5 Verification Tag [Normal verification]
2756 * Inputs
2757 * (endpoint, asoc, chunk)
2758 *
2759 * Outputs
2760 * (asoc, reply_msg, msg_up, timers, counters)
2761 *
2762 * The return value is the disposition of the chunk.
2763 */
2764sctp_disposition_t sctp_sf_eat_data_fast_4_4(const struct sctp_endpoint *ep,
2765 const struct sctp_association *asoc,
2766 const sctp_subtype_t type,
2767 void *arg,
2768 sctp_cmd_seq_t *commands)
2769{
2770 struct sctp_chunk *chunk = arg;
2771 int error;
2772
2773 if (!sctp_vtag_verify(chunk, asoc)) {
2774 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
2775 SCTP_NULL());
2776 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2777 }
2778
2779 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
2780 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2781 commands);
2782
2783 error = sctp_eat_data(asoc, chunk, commands );
2784 switch (error) {
2785 case SCTP_IERROR_NO_ERROR:
2786 case SCTP_IERROR_HIGH_TSN:
2787 case SCTP_IERROR_DUP_TSN:
2788 case SCTP_IERROR_IGNORE_TSN:
2789 case SCTP_IERROR_BAD_STREAM:
2790 break;
2791 case SCTP_IERROR_NO_DATA:
2792 goto consume;
2793 default:
2794 BUG();
2795 }
2796
2797 /* Go a head and force a SACK, since we are shutting down. */
2798
2799 /* Implementor's Guide.
2800 *
2801 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
2802 * respond to each received packet containing one or more DATA chunk(s)
2803 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
2804 */
2805 if (chunk->end_of_packet) {
2806 /* We must delay the chunk creation since the cumulative
2807 * TSN has not been updated yet.
2808 */
2809 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
2810 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
2811 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2812 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2813 }
2814
2815consume:
2816 return SCTP_DISPOSITION_CONSUME;
2817}
2818
2819/*
2820 * Section: 6.2 Processing a Received SACK
2821 * D) Any time a SACK arrives, the endpoint performs the following:
2822 *
2823 * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point,
2824 * then drop the SACK. Since Cumulative TSN Ack is monotonically
2825 * increasing, a SACK whose Cumulative TSN Ack is less than the
2826 * Cumulative TSN Ack Point indicates an out-of-order SACK.
2827 *
2828 * ii) Set rwnd equal to the newly received a_rwnd minus the number
2829 * of bytes still outstanding after processing the Cumulative TSN Ack
2830 * and the Gap Ack Blocks.
2831 *
2832 * iii) If the SACK is missing a TSN that was previously
2833 * acknowledged via a Gap Ack Block (e.g., the data receiver
2834 * reneged on the data), then mark the corresponding DATA chunk
2835 * as available for retransmit: Mark it as missing for fast
2836 * retransmit as described in Section 7.2.4 and if no retransmit
2837 * timer is running for the destination address to which the DATA
2838 * chunk was originally transmitted, then T3-rtx is started for
2839 * that destination address.
2840 *
2841 * Verification Tag: 8.5 Verification Tag [Normal verification]
2842 *
2843 * Inputs
2844 * (endpoint, asoc, chunk)
2845 *
2846 * Outputs
2847 * (asoc, reply_msg, msg_up, timers, counters)
2848 *
2849 * The return value is the disposition of the chunk.
2850 */
2851sctp_disposition_t sctp_sf_eat_sack_6_2(const struct sctp_endpoint *ep,
2852 const struct sctp_association *asoc,
2853 const sctp_subtype_t type,
2854 void *arg,
2855 sctp_cmd_seq_t *commands)
2856{
2857 struct sctp_chunk *chunk = arg;
2858 sctp_sackhdr_t *sackh;
2859 __u32 ctsn;
2860
2861 if (!sctp_vtag_verify(chunk, asoc))
2862 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2863
2864 /* Make sure that the SACK chunk has a valid length. */
2865 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_sack_chunk_t)))
2866 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2867 commands);
2868
2869 /* Pull the SACK chunk from the data buffer */
2870 sackh = sctp_sm_pull_sack(chunk);
2871 /* Was this a bogus SACK? */
2872 if (!sackh)
2873 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2874 chunk->subh.sack_hdr = sackh;
2875 ctsn = ntohl(sackh->cum_tsn_ack);
2876
2877 /* i) If Cumulative TSN Ack is less than the Cumulative TSN
2878 * Ack Point, then drop the SACK. Since Cumulative TSN
2879 * Ack is monotonically increasing, a SACK whose
2880 * Cumulative TSN Ack is less than the Cumulative TSN Ack
2881 * Point indicates an out-of-order SACK.
2882 */
2883 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
2884 SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn);
2885 SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc->ctsn_ack_point);
2886 return SCTP_DISPOSITION_DISCARD;
2887 }
2888
2889 /* Return this SACK for further processing. */
2890 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_SACKH(sackh));
2891
2892 /* Note: We do the rest of the work on the PROCESS_SACK
2893 * sideeffect.
2894 */
2895 return SCTP_DISPOSITION_CONSUME;
2896}
2897
2898/*
2899 * Generate an ABORT in response to a packet.
2900 *
Jerome Forissier047a2422005-04-28 11:58:43 -07002901 * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41
Linus Torvalds1da177e2005-04-16 15:20:36 -07002902 *
Jerome Forissier047a2422005-04-28 11:58:43 -07002903 * 8) The receiver should respond to the sender of the OOTB packet with
2904 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
2905 * MUST fill in the Verification Tag field of the outbound packet
2906 * with the value found in the Verification Tag field of the OOTB
2907 * packet and set the T-bit in the Chunk Flags to indicate that the
2908 * Verification Tag is reflected. After sending this ABORT, the
2909 * receiver of the OOTB packet shall discard the OOTB packet and take
2910 * no further action.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002911 *
2912 * Verification Tag:
2913 *
2914 * The return value is the disposition of the chunk.
2915*/
2916sctp_disposition_t sctp_sf_tabort_8_4_8(const struct sctp_endpoint *ep,
2917 const struct sctp_association *asoc,
2918 const sctp_subtype_t type,
2919 void *arg,
2920 sctp_cmd_seq_t *commands)
2921{
2922 struct sctp_packet *packet = NULL;
2923 struct sctp_chunk *chunk = arg;
2924 struct sctp_chunk *abort;
2925
2926 packet = sctp_ootb_pkt_new(asoc, chunk);
2927
2928 if (packet) {
2929 /* Make an ABORT. The T bit will be set if the asoc
2930 * is NULL.
2931 */
2932 abort = sctp_make_abort(asoc, chunk, 0);
2933 if (!abort) {
2934 sctp_ootb_pkt_free(packet);
2935 return SCTP_DISPOSITION_NOMEM;
2936 }
2937
Jerome Forissier047a2422005-04-28 11:58:43 -07002938 /* Reflect vtag if T-Bit is set */
2939 if (sctp_test_T_bit(abort))
2940 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
2941
Linus Torvalds1da177e2005-04-16 15:20:36 -07002942 /* Set the skb to the belonging sock for accounting. */
2943 abort->skb->sk = ep->base.sk;
2944
2945 sctp_packet_append_chunk(packet, abort);
2946
2947 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
2948 SCTP_PACKET(packet));
2949
2950 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
2951
2952 return SCTP_DISPOSITION_CONSUME;
2953 }
2954
2955 return SCTP_DISPOSITION_NOMEM;
2956}
2957
2958/*
2959 * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR
2960 * event as ULP notification for each cause included in the chunk.
2961 *
2962 * API 5.3.1.3 - SCTP_REMOTE_ERROR
2963 *
2964 * The return value is the disposition of the chunk.
2965*/
2966sctp_disposition_t sctp_sf_operr_notify(const struct sctp_endpoint *ep,
2967 const struct sctp_association *asoc,
2968 const sctp_subtype_t type,
2969 void *arg,
2970 sctp_cmd_seq_t *commands)
2971{
2972 struct sctp_chunk *chunk = arg;
2973 struct sctp_ulpevent *ev;
2974
2975 if (!sctp_vtag_verify(chunk, asoc))
2976 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2977
2978 /* Make sure that the ERROR chunk has a valid length. */
2979 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
2980 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2981 commands);
2982
2983 while (chunk->chunk_end > chunk->skb->data) {
2984 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
2985 GFP_ATOMIC);
2986 if (!ev)
2987 goto nomem;
2988
2989 if (!sctp_add_cmd(commands, SCTP_CMD_EVENT_ULP,
2990 SCTP_ULPEVENT(ev))) {
2991 sctp_ulpevent_free(ev);
2992 goto nomem;
2993 }
2994
2995 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_OPERR,
2996 SCTP_CHUNK(chunk));
2997 }
2998 return SCTP_DISPOSITION_CONSUME;
2999
3000nomem:
3001 return SCTP_DISPOSITION_NOMEM;
3002}
3003
3004/*
3005 * Process an inbound SHUTDOWN ACK.
3006 *
3007 * From Section 9.2:
3008 * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3009 * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its
3010 * peer, and remove all record of the association.
3011 *
3012 * The return value is the disposition.
3013 */
3014sctp_disposition_t sctp_sf_do_9_2_final(const struct sctp_endpoint *ep,
3015 const struct sctp_association *asoc,
3016 const sctp_subtype_t type,
3017 void *arg,
3018 sctp_cmd_seq_t *commands)
3019{
3020 struct sctp_chunk *chunk = arg;
3021 struct sctp_chunk *reply;
3022 struct sctp_ulpevent *ev;
3023
3024 if (!sctp_vtag_verify(chunk, asoc))
3025 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3026
3027 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3028 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3029 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3030 commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003031 /* 10.2 H) SHUTDOWN COMPLETE notification
3032 *
3033 * When SCTP completes the shutdown procedures (section 9.2) this
3034 * notification is passed to the upper layer.
3035 */
3036 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
3037 0, 0, 0, GFP_ATOMIC);
3038 if (!ev)
3039 goto nomem;
3040
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07003041 /* ...send a SHUTDOWN COMPLETE chunk to its peer, */
3042 reply = sctp_make_shutdown_complete(asoc, chunk);
3043 if (!reply)
3044 goto nomem_chunk;
3045
3046 /* Do all the commands now (after allocation), so that we
3047 * have consistent state if memory allocation failes
3048 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07003049 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
3050
3051 /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3052 * stop the T2-shutdown timer,
3053 */
3054 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3055 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3056
3057 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3058 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
3059
Linus Torvalds1da177e2005-04-16 15:20:36 -07003060 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3061 SCTP_STATE(SCTP_STATE_CLOSED));
3062 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
3063 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3064 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
3065
3066 /* ...and remove all record of the association. */
3067 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
3068 return SCTP_DISPOSITION_DELETE_TCB;
3069
Vladislav Yasevichdf7deeb2006-08-22 00:19:51 -07003070nomem_chunk:
3071 sctp_ulpevent_free(ev);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003072nomem:
3073 return SCTP_DISPOSITION_NOMEM;
3074}
3075
3076/*
Jerome Forissier047a2422005-04-28 11:58:43 -07003077 * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41.
3078 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003079 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3080 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3081 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3082 * packet must fill in the Verification Tag field of the outbound
3083 * packet with the Verification Tag received in the SHUTDOWN ACK and
Jerome Forissier047a2422005-04-28 11:58:43 -07003084 * set the T-bit in the Chunk Flags to indicate that the Verification
3085 * Tag is reflected.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003086 *
3087 * 8) The receiver should respond to the sender of the OOTB packet with
3088 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3089 * MUST fill in the Verification Tag field of the outbound packet
3090 * with the value found in the Verification Tag field of the OOTB
Jerome Forissier047a2422005-04-28 11:58:43 -07003091 * packet and set the T-bit in the Chunk Flags to indicate that the
3092 * Verification Tag is reflected. After sending this ABORT, the
3093 * receiver of the OOTB packet shall discard the OOTB packet and take
3094 * no further action.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003095 */
3096sctp_disposition_t sctp_sf_ootb(const struct sctp_endpoint *ep,
3097 const struct sctp_association *asoc,
3098 const sctp_subtype_t type,
3099 void *arg,
3100 sctp_cmd_seq_t *commands)
3101{
3102 struct sctp_chunk *chunk = arg;
3103 struct sk_buff *skb = chunk->skb;
3104 sctp_chunkhdr_t *ch;
3105 __u8 *ch_end;
3106 int ootb_shut_ack = 0;
3107
3108 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES);
3109
3110 ch = (sctp_chunkhdr_t *) chunk->chunk_hdr;
3111 do {
3112 /* Break out if chunk length is less then minimal. */
3113 if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t))
3114 break;
3115
3116 ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
Tsutomu Fujiia7d1f1b2006-01-17 11:57:09 -08003117 if (ch_end > skb->tail)
3118 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003119
3120 if (SCTP_CID_SHUTDOWN_ACK == ch->type)
3121 ootb_shut_ack = 1;
3122
3123 /* RFC 2960, Section 3.3.7
3124 * Moreover, under any circumstances, an endpoint that
3125 * receives an ABORT MUST NOT respond to that ABORT by
3126 * sending an ABORT of its own.
3127 */
3128 if (SCTP_CID_ABORT == ch->type)
3129 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3130
3131 ch = (sctp_chunkhdr_t *) ch_end;
3132 } while (ch_end < skb->tail);
3133
3134 if (ootb_shut_ack)
3135 sctp_sf_shut_8_4_5(ep, asoc, type, arg, commands);
3136 else
3137 sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
3138
3139 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3140}
3141
3142/*
3143 * Handle an "Out of the blue" SHUTDOWN ACK.
3144 *
Jerome Forissier047a2422005-04-28 11:58:43 -07003145 * Section: 8.4 5, sctpimpguide 2.41.
3146 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003147 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
Jerome Forissier047a2422005-04-28 11:58:43 -07003148 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3149 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3150 * packet must fill in the Verification Tag field of the outbound
3151 * packet with the Verification Tag received in the SHUTDOWN ACK and
3152 * set the T-bit in the Chunk Flags to indicate that the Verification
3153 * Tag is reflected.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003154 *
3155 * Inputs
3156 * (endpoint, asoc, type, arg, commands)
3157 *
3158 * Outputs
3159 * (sctp_disposition_t)
3160 *
3161 * The return value is the disposition of the chunk.
3162 */
3163static sctp_disposition_t sctp_sf_shut_8_4_5(const struct sctp_endpoint *ep,
3164 const struct sctp_association *asoc,
3165 const sctp_subtype_t type,
3166 void *arg,
3167 sctp_cmd_seq_t *commands)
3168{
3169 struct sctp_packet *packet = NULL;
3170 struct sctp_chunk *chunk = arg;
3171 struct sctp_chunk *shut;
3172
3173 packet = sctp_ootb_pkt_new(asoc, chunk);
3174
3175 if (packet) {
3176 /* Make an SHUTDOWN_COMPLETE.
3177 * The T bit will be set if the asoc is NULL.
3178 */
3179 shut = sctp_make_shutdown_complete(asoc, chunk);
3180 if (!shut) {
3181 sctp_ootb_pkt_free(packet);
3182 return SCTP_DISPOSITION_NOMEM;
3183 }
3184
Jerome Forissier047a2422005-04-28 11:58:43 -07003185 /* Reflect vtag if T-Bit is set */
3186 if (sctp_test_T_bit(shut))
3187 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3188
Linus Torvalds1da177e2005-04-16 15:20:36 -07003189 /* Set the skb to the belonging sock for accounting. */
3190 shut->skb->sk = ep->base.sk;
3191
3192 sctp_packet_append_chunk(packet, shut);
3193
3194 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3195 SCTP_PACKET(packet));
3196
3197 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
3198
3199 /* If the chunk length is invalid, we don't want to process
3200 * the reset of the packet.
3201 */
3202 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3203 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3204
3205 return SCTP_DISPOSITION_CONSUME;
3206 }
3207
3208 return SCTP_DISPOSITION_NOMEM;
3209}
3210
3211/*
3212 * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state.
3213 *
3214 * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK
3215 * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the
3216 * procedures in section 8.4 SHOULD be followed, in other words it
3217 * should be treated as an Out Of The Blue packet.
3218 * [This means that we do NOT check the Verification Tag on these
3219 * chunks. --piggy ]
3220 *
3221 */
3222sctp_disposition_t sctp_sf_do_8_5_1_E_sa(const struct sctp_endpoint *ep,
3223 const struct sctp_association *asoc,
3224 const sctp_subtype_t type,
3225 void *arg,
3226 sctp_cmd_seq_t *commands)
3227{
3228 /* Although we do have an association in this case, it corresponds
3229 * to a restarted association. So the packet is treated as an OOTB
3230 * packet and the state function that handles OOTB SHUTDOWN_ACK is
3231 * called with a NULL association.
3232 */
3233 return sctp_sf_shut_8_4_5(ep, NULL, type, arg, commands);
3234}
3235
3236/* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */
3237sctp_disposition_t sctp_sf_do_asconf(const struct sctp_endpoint *ep,
3238 const struct sctp_association *asoc,
3239 const sctp_subtype_t type, void *arg,
3240 sctp_cmd_seq_t *commands)
3241{
3242 struct sctp_chunk *chunk = arg;
3243 struct sctp_chunk *asconf_ack = NULL;
3244 sctp_addiphdr_t *hdr;
3245 __u32 serial;
3246
3247 if (!sctp_vtag_verify(chunk, asoc)) {
3248 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3249 SCTP_NULL());
3250 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3251 }
3252
3253 /* Make sure that the ASCONF ADDIP chunk has a valid length. */
3254 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_addip_chunk_t)))
3255 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3256 commands);
3257
3258 hdr = (sctp_addiphdr_t *)chunk->skb->data;
3259 serial = ntohl(hdr->serial);
3260
3261 /* ADDIP 4.2 C1) Compare the value of the serial number to the value
3262 * the endpoint stored in a new association variable
3263 * 'Peer-Serial-Number'.
3264 */
3265 if (serial == asoc->peer.addip_serial + 1) {
3266 /* ADDIP 4.2 C2) If the value found in the serial number is
3267 * equal to the ('Peer-Serial-Number' + 1), the endpoint MUST
3268 * do V1-V5.
3269 */
3270 asconf_ack = sctp_process_asconf((struct sctp_association *)
3271 asoc, chunk);
3272 if (!asconf_ack)
3273 return SCTP_DISPOSITION_NOMEM;
3274 } else if (serial == asoc->peer.addip_serial) {
3275 /* ADDIP 4.2 C3) If the value found in the serial number is
3276 * equal to the value stored in the 'Peer-Serial-Number'
3277 * IMPLEMENTATION NOTE: As an optimization a receiver may wish
3278 * to save the last ASCONF-ACK for some predetermined period of
3279 * time and instead of re-processing the ASCONF (with the same
3280 * serial number) it may just re-transmit the ASCONF-ACK.
3281 */
3282 if (asoc->addip_last_asconf_ack)
3283 asconf_ack = asoc->addip_last_asconf_ack;
3284 else
3285 return SCTP_DISPOSITION_DISCARD;
3286 } else {
3287 /* ADDIP 4.2 C4) Otherwise, the ASCONF Chunk is discarded since
3288 * it must be either a stale packet or from an attacker.
3289 */
3290 return SCTP_DISPOSITION_DISCARD;
3291 }
3292
3293 /* ADDIP 4.2 C5) In both cases C2 and C3 the ASCONF-ACK MUST be sent
3294 * back to the source address contained in the IP header of the ASCONF
3295 * being responded to.
3296 */
3297 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(asconf_ack));
3298
3299 return SCTP_DISPOSITION_CONSUME;
3300}
3301
3302/*
3303 * ADDIP Section 4.3 General rules for address manipulation
3304 * When building TLV parameters for the ASCONF Chunk that will add or
3305 * delete IP addresses the D0 to D13 rules should be applied:
3306 */
3307sctp_disposition_t sctp_sf_do_asconf_ack(const struct sctp_endpoint *ep,
3308 const struct sctp_association *asoc,
3309 const sctp_subtype_t type, void *arg,
3310 sctp_cmd_seq_t *commands)
3311{
3312 struct sctp_chunk *asconf_ack = arg;
3313 struct sctp_chunk *last_asconf = asoc->addip_last_asconf;
3314 struct sctp_chunk *abort;
3315 sctp_addiphdr_t *addip_hdr;
3316 __u32 sent_serial, rcvd_serial;
3317
3318 if (!sctp_vtag_verify(asconf_ack, asoc)) {
3319 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3320 SCTP_NULL());
3321 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3322 }
3323
3324 /* Make sure that the ADDIP chunk has a valid length. */
3325 if (!sctp_chunk_length_valid(asconf_ack, sizeof(sctp_addip_chunk_t)))
3326 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3327 commands);
3328
3329 addip_hdr = (sctp_addiphdr_t *)asconf_ack->skb->data;
3330 rcvd_serial = ntohl(addip_hdr->serial);
3331
3332 if (last_asconf) {
3333 addip_hdr = (sctp_addiphdr_t *)last_asconf->subh.addip_hdr;
3334 sent_serial = ntohl(addip_hdr->serial);
3335 } else {
3336 sent_serial = asoc->addip_serial - 1;
3337 }
3338
3339 /* D0) If an endpoint receives an ASCONF-ACK that is greater than or
3340 * equal to the next serial number to be used but no ASCONF chunk is
3341 * outstanding the endpoint MUST ABORT the association. Note that a
3342 * sequence number is greater than if it is no more than 2^^31-1
3343 * larger than the current sequence number (using serial arithmetic).
3344 */
3345 if (ADDIP_SERIAL_gte(rcvd_serial, sent_serial + 1) &&
3346 !(asoc->addip_last_asconf)) {
3347 abort = sctp_make_abort(asoc, asconf_ack,
3348 sizeof(sctp_errhdr_t));
3349 if (abort) {
3350 sctp_init_cause(abort, SCTP_ERROR_ASCONF_ACK, NULL, 0);
3351 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3352 SCTP_CHUNK(abort));
3353 }
3354 /* We are going to ABORT, so we might as well stop
3355 * processing the rest of the chunks in the packet.
3356 */
3357 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3358 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3359 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07003360 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
3361 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003362 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08003363 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003364 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
3365 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3366 return SCTP_DISPOSITION_ABORT;
3367 }
3368
3369 if ((rcvd_serial == sent_serial) && asoc->addip_last_asconf) {
3370 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3371 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3372
3373 if (!sctp_process_asconf_ack((struct sctp_association *)asoc,
3374 asconf_ack))
3375 return SCTP_DISPOSITION_CONSUME;
3376
3377 abort = sctp_make_abort(asoc, asconf_ack,
3378 sizeof(sctp_errhdr_t));
3379 if (abort) {
3380 sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, NULL, 0);
3381 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3382 SCTP_CHUNK(abort));
3383 }
3384 /* We are going to ABORT, so we might as well stop
3385 * processing the rest of the chunks in the packet.
3386 */
3387 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07003388 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
3389 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003390 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08003391 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003392 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
3393 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3394 return SCTP_DISPOSITION_ABORT;
3395 }
3396
3397 return SCTP_DISPOSITION_DISCARD;
3398}
3399
3400/*
3401 * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP
3402 *
3403 * When a FORWARD TSN chunk arrives, the data receiver MUST first update
3404 * its cumulative TSN point to the value carried in the FORWARD TSN
3405 * chunk, and then MUST further advance its cumulative TSN point locally
3406 * if possible.
3407 * After the above processing, the data receiver MUST stop reporting any
3408 * missing TSNs earlier than or equal to the new cumulative TSN point.
3409 *
3410 * Verification Tag: 8.5 Verification Tag [Normal verification]
3411 *
3412 * The return value is the disposition of the chunk.
3413 */
3414sctp_disposition_t sctp_sf_eat_fwd_tsn(const struct sctp_endpoint *ep,
3415 const struct sctp_association *asoc,
3416 const sctp_subtype_t type,
3417 void *arg,
3418 sctp_cmd_seq_t *commands)
3419{
3420 struct sctp_chunk *chunk = arg;
3421 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
3422 __u16 len;
3423 __u32 tsn;
3424
3425 if (!sctp_vtag_verify(chunk, asoc)) {
3426 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3427 SCTP_NULL());
3428 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3429 }
3430
3431 /* Make sure that the FORWARD_TSN chunk has valid length. */
3432 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
3433 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3434 commands);
3435
3436 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3437 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3438 len = ntohs(chunk->chunk_hdr->length);
3439 len -= sizeof(struct sctp_chunkhdr);
3440 skb_pull(chunk->skb, len);
3441
3442 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
3443 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __FUNCTION__, tsn);
3444
3445 /* The TSN is too high--silently discard the chunk and count on it
3446 * getting retransmitted later.
3447 */
3448 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3449 goto discard_noforce;
3450
3451 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3452 if (len > sizeof(struct sctp_fwdtsn_hdr))
3453 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
3454 SCTP_CHUNK(chunk));
3455
3456 /* Count this as receiving DATA. */
3457 if (asoc->autoclose) {
3458 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3459 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
3460 }
3461
3462 /* FIXME: For now send a SACK, but DATA processing may
3463 * send another.
3464 */
3465 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
Linus Torvalds1da177e2005-04-16 15:20:36 -07003466
3467 return SCTP_DISPOSITION_CONSUME;
3468
3469discard_noforce:
3470 return SCTP_DISPOSITION_DISCARD;
3471}
3472
3473sctp_disposition_t sctp_sf_eat_fwd_tsn_fast(
3474 const struct sctp_endpoint *ep,
3475 const struct sctp_association *asoc,
3476 const sctp_subtype_t type,
3477 void *arg,
3478 sctp_cmd_seq_t *commands)
3479{
3480 struct sctp_chunk *chunk = arg;
3481 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
3482 __u16 len;
3483 __u32 tsn;
3484
3485 if (!sctp_vtag_verify(chunk, asoc)) {
3486 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3487 SCTP_NULL());
3488 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3489 }
3490
3491 /* Make sure that the FORWARD_TSN chunk has a valid length. */
3492 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
3493 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3494 commands);
3495
3496 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3497 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3498 len = ntohs(chunk->chunk_hdr->length);
3499 len -= sizeof(struct sctp_chunkhdr);
3500 skb_pull(chunk->skb, len);
3501
3502 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
3503 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __FUNCTION__, tsn);
3504
3505 /* The TSN is too high--silently discard the chunk and count on it
3506 * getting retransmitted later.
3507 */
3508 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3509 goto gen_shutdown;
3510
3511 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3512 if (len > sizeof(struct sctp_fwdtsn_hdr))
3513 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
3514 SCTP_CHUNK(chunk));
3515
3516 /* Go a head and force a SACK, since we are shutting down. */
3517gen_shutdown:
3518 /* Implementor's Guide.
3519 *
3520 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3521 * respond to each received packet containing one or more DATA chunk(s)
3522 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3523 */
3524 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
3525 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3526 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3527 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3528
3529 return SCTP_DISPOSITION_CONSUME;
3530}
3531
3532/*
3533 * Process an unknown chunk.
3534 *
3535 * Section: 3.2. Also, 2.1 in the implementor's guide.
3536 *
3537 * Chunk Types are encoded such that the highest-order two bits specify
3538 * the action that must be taken if the processing endpoint does not
3539 * recognize the Chunk Type.
3540 *
3541 * 00 - Stop processing this SCTP packet and discard it, do not process
3542 * any further chunks within it.
3543 *
3544 * 01 - Stop processing this SCTP packet and discard it, do not process
3545 * any further chunks within it, and report the unrecognized
3546 * chunk in an 'Unrecognized Chunk Type'.
3547 *
3548 * 10 - Skip this chunk and continue processing.
3549 *
3550 * 11 - Skip this chunk and continue processing, but report in an ERROR
3551 * Chunk using the 'Unrecognized Chunk Type' cause of error.
3552 *
3553 * The return value is the disposition of the chunk.
3554 */
3555sctp_disposition_t sctp_sf_unk_chunk(const struct sctp_endpoint *ep,
3556 const struct sctp_association *asoc,
3557 const sctp_subtype_t type,
3558 void *arg,
3559 sctp_cmd_seq_t *commands)
3560{
3561 struct sctp_chunk *unk_chunk = arg;
3562 struct sctp_chunk *err_chunk;
3563 sctp_chunkhdr_t *hdr;
3564
3565 SCTP_DEBUG_PRINTK("Processing the unknown chunk id %d.\n", type.chunk);
3566
3567 if (!sctp_vtag_verify(unk_chunk, asoc))
3568 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3569
3570 /* Make sure that the chunk has a valid length.
3571 * Since we don't know the chunk type, we use a general
3572 * chunkhdr structure to make a comparison.
3573 */
3574 if (!sctp_chunk_length_valid(unk_chunk, sizeof(sctp_chunkhdr_t)))
3575 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3576 commands);
3577
3578 switch (type.chunk & SCTP_CID_ACTION_MASK) {
3579 case SCTP_CID_ACTION_DISCARD:
3580 /* Discard the packet. */
3581 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3582 break;
3583 case SCTP_CID_ACTION_DISCARD_ERR:
3584 /* Discard the packet. */
3585 sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3586
3587 /* Generate an ERROR chunk as response. */
3588 hdr = unk_chunk->chunk_hdr;
3589 err_chunk = sctp_make_op_error(asoc, unk_chunk,
3590 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
3591 WORD_ROUND(ntohs(hdr->length)));
3592 if (err_chunk) {
3593 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3594 SCTP_CHUNK(err_chunk));
3595 }
3596 return SCTP_DISPOSITION_CONSUME;
3597 break;
3598 case SCTP_CID_ACTION_SKIP:
3599 /* Skip the chunk. */
3600 return SCTP_DISPOSITION_DISCARD;
3601 break;
3602 case SCTP_CID_ACTION_SKIP_ERR:
3603 /* Generate an ERROR chunk as response. */
3604 hdr = unk_chunk->chunk_hdr;
3605 err_chunk = sctp_make_op_error(asoc, unk_chunk,
3606 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
3607 WORD_ROUND(ntohs(hdr->length)));
3608 if (err_chunk) {
3609 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3610 SCTP_CHUNK(err_chunk));
3611 }
3612 /* Skip the chunk. */
3613 return SCTP_DISPOSITION_CONSUME;
3614 break;
3615 default:
3616 break;
3617 }
3618
3619 return SCTP_DISPOSITION_DISCARD;
3620}
3621
3622/*
3623 * Discard the chunk.
3624 *
3625 * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2
3626 * [Too numerous to mention...]
3627 * Verification Tag: No verification needed.
3628 * Inputs
3629 * (endpoint, asoc, chunk)
3630 *
3631 * Outputs
3632 * (asoc, reply_msg, msg_up, timers, counters)
3633 *
3634 * The return value is the disposition of the chunk.
3635 */
3636sctp_disposition_t sctp_sf_discard_chunk(const struct sctp_endpoint *ep,
3637 const struct sctp_association *asoc,
3638 const sctp_subtype_t type,
3639 void *arg,
3640 sctp_cmd_seq_t *commands)
3641{
3642 SCTP_DEBUG_PRINTK("Chunk %d is discarded\n", type.chunk);
3643 return SCTP_DISPOSITION_DISCARD;
3644}
3645
3646/*
3647 * Discard the whole packet.
3648 *
3649 * Section: 8.4 2)
3650 *
3651 * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST
3652 * silently discard the OOTB packet and take no further action.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003653 *
3654 * Verification Tag: No verification necessary
3655 *
3656 * Inputs
3657 * (endpoint, asoc, chunk)
3658 *
3659 * Outputs
3660 * (asoc, reply_msg, msg_up, timers, counters)
3661 *
3662 * The return value is the disposition of the chunk.
3663 */
3664sctp_disposition_t sctp_sf_pdiscard(const struct sctp_endpoint *ep,
3665 const struct sctp_association *asoc,
3666 const sctp_subtype_t type,
3667 void *arg,
3668 sctp_cmd_seq_t *commands)
3669{
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07003670 SCTP_INC_STATS(SCTP_MIB_IN_PKT_DISCARDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003671 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
3672
3673 return SCTP_DISPOSITION_CONSUME;
3674}
3675
3676
3677/*
3678 * The other end is violating protocol.
3679 *
3680 * Section: Not specified
3681 * Verification Tag: Not specified
3682 * Inputs
3683 * (endpoint, asoc, chunk)
3684 *
3685 * Outputs
3686 * (asoc, reply_msg, msg_up, timers, counters)
3687 *
3688 * We simply tag the chunk as a violation. The state machine will log
3689 * the violation and continue.
3690 */
3691sctp_disposition_t sctp_sf_violation(const struct sctp_endpoint *ep,
3692 const struct sctp_association *asoc,
3693 const sctp_subtype_t type,
3694 void *arg,
3695 sctp_cmd_seq_t *commands)
3696{
3697 return SCTP_DISPOSITION_VIOLATION;
3698}
3699
3700
3701/*
3702 * Handle a protocol violation when the chunk length is invalid.
3703 * "Invalid" length is identified as smaller then the minimal length a
3704 * given chunk can be. For example, a SACK chunk has invalid length
3705 * if it's length is set to be smaller then the size of sctp_sack_chunk_t.
3706 *
3707 * We inform the other end by sending an ABORT with a Protocol Violation
3708 * error code.
3709 *
3710 * Section: Not specified
3711 * Verification Tag: Nothing to do
3712 * Inputs
3713 * (endpoint, asoc, chunk)
3714 *
3715 * Outputs
3716 * (reply_msg, msg_up, counters)
3717 *
3718 * Generate an ABORT chunk and terminate the association.
3719 */
Adrian Bunk52c1da32005-06-23 22:05:33 -07003720static sctp_disposition_t sctp_sf_violation_chunklen(
3721 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003722 const struct sctp_association *asoc,
3723 const sctp_subtype_t type,
3724 void *arg,
3725 sctp_cmd_seq_t *commands)
3726{
3727 struct sctp_chunk *chunk = arg;
3728 struct sctp_chunk *abort = NULL;
3729 char err_str[]="The following chunk had invalid length:";
3730
3731 /* Make the abort chunk. */
3732 abort = sctp_make_abort_violation(asoc, chunk, err_str,
3733 sizeof(err_str));
3734 if (!abort)
3735 goto nomem;
3736
3737 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
3738 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
3739
3740 if (asoc->state <= SCTP_STATE_COOKIE_ECHOED) {
3741 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3742 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07003743 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
3744 SCTP_ERROR(ECONNREFUSED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003745 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08003746 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003747 } else {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07003748 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
3749 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003750 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08003751 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003752 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3753 }
3754
3755 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
3756
3757 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
3758
3759 return SCTP_DISPOSITION_ABORT;
3760
3761nomem:
3762 return SCTP_DISPOSITION_NOMEM;
3763}
3764
3765/***************************************************************************
3766 * These are the state functions for handling primitive (Section 10) events.
3767 ***************************************************************************/
3768/*
3769 * sctp_sf_do_prm_asoc
3770 *
3771 * Section: 10.1 ULP-to-SCTP
3772 * B) Associate
3773 *
3774 * Format: ASSOCIATE(local SCTP instance name, destination transport addr,
3775 * outbound stream count)
3776 * -> association id [,destination transport addr list] [,outbound stream
3777 * count]
3778 *
3779 * This primitive allows the upper layer to initiate an association to a
3780 * specific peer endpoint.
3781 *
3782 * The peer endpoint shall be specified by one of the transport addresses
3783 * which defines the endpoint (see Section 1.4). If the local SCTP
3784 * instance has not been initialized, the ASSOCIATE is considered an
3785 * error.
3786 * [This is not relevant for the kernel implementation since we do all
3787 * initialization at boot time. It we hadn't initialized we wouldn't
3788 * get anywhere near this code.]
3789 *
3790 * An association id, which is a local handle to the SCTP association,
3791 * will be returned on successful establishment of the association. If
3792 * SCTP is not able to open an SCTP association with the peer endpoint,
3793 * an error is returned.
3794 * [In the kernel implementation, the struct sctp_association needs to
3795 * be created BEFORE causing this primitive to run.]
3796 *
3797 * Other association parameters may be returned, including the
3798 * complete destination transport addresses of the peer as well as the
3799 * outbound stream count of the local endpoint. One of the transport
3800 * address from the returned destination addresses will be selected by
3801 * the local endpoint as default primary path for sending SCTP packets
3802 * to this peer. The returned "destination transport addr list" can
3803 * be used by the ULP to change the default primary path or to force
3804 * sending a packet to a specific transport address. [All of this
3805 * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING
3806 * function.]
3807 *
3808 * Mandatory attributes:
3809 *
3810 * o local SCTP instance name - obtained from the INITIALIZE operation.
3811 * [This is the argument asoc.]
3812 * o destination transport addr - specified as one of the transport
3813 * addresses of the peer endpoint with which the association is to be
3814 * established.
3815 * [This is asoc->peer.active_path.]
3816 * o outbound stream count - the number of outbound streams the ULP
3817 * would like to open towards this peer endpoint.
3818 * [BUG: This is not currently implemented.]
3819 * Optional attributes:
3820 *
3821 * None.
3822 *
3823 * The return value is a disposition.
3824 */
3825sctp_disposition_t sctp_sf_do_prm_asoc(const struct sctp_endpoint *ep,
3826 const struct sctp_association *asoc,
3827 const sctp_subtype_t type,
3828 void *arg,
3829 sctp_cmd_seq_t *commands)
3830{
3831 struct sctp_chunk *repl;
3832
3833 /* The comment below says that we enter COOKIE-WAIT AFTER
3834 * sending the INIT, but that doesn't actually work in our
3835 * implementation...
3836 */
3837 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3838 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
3839
3840 /* RFC 2960 5.1 Normal Establishment of an Association
3841 *
3842 * A) "A" first sends an INIT chunk to "Z". In the INIT, "A"
3843 * must provide its Verification Tag (Tag_A) in the Initiate
3844 * Tag field. Tag_A SHOULD be a random number in the range of
3845 * 1 to 4294967295 (see 5.3.1 for Tag value selection). ...
3846 */
3847
3848 repl = sctp_make_init(asoc, &asoc->base.bind_addr, GFP_ATOMIC, 0);
3849 if (!repl)
3850 goto nomem;
3851
3852 /* Cast away the const modifier, as we want to just
3853 * rerun it through as a sideffect.
3854 */
3855 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC,
3856 SCTP_ASOC((struct sctp_association *) asoc));
3857
Frank Filz3f7a87d2005-06-20 13:14:57 -07003858 /* Choose transport for INIT. */
3859 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
3860 SCTP_CHUNK(repl));
3861
Linus Torvalds1da177e2005-04-16 15:20:36 -07003862 /* After sending the INIT, "A" starts the T1-init timer and
3863 * enters the COOKIE-WAIT state.
3864 */
3865 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
3866 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
3867 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
3868 return SCTP_DISPOSITION_CONSUME;
3869
3870nomem:
3871 return SCTP_DISPOSITION_NOMEM;
3872}
3873
3874/*
3875 * Process the SEND primitive.
3876 *
3877 * Section: 10.1 ULP-to-SCTP
3878 * E) Send
3879 *
3880 * Format: SEND(association id, buffer address, byte count [,context]
3881 * [,stream id] [,life time] [,destination transport address]
3882 * [,unorder flag] [,no-bundle flag] [,payload protocol-id] )
3883 * -> result
3884 *
3885 * This is the main method to send user data via SCTP.
3886 *
3887 * Mandatory attributes:
3888 *
3889 * o association id - local handle to the SCTP association
3890 *
3891 * o buffer address - the location where the user message to be
3892 * transmitted is stored;
3893 *
3894 * o byte count - The size of the user data in number of bytes;
3895 *
3896 * Optional attributes:
3897 *
3898 * o context - an optional 32 bit integer that will be carried in the
3899 * sending failure notification to the ULP if the transportation of
3900 * this User Message fails.
3901 *
3902 * o stream id - to indicate which stream to send the data on. If not
3903 * specified, stream 0 will be used.
3904 *
3905 * o life time - specifies the life time of the user data. The user data
3906 * will not be sent by SCTP after the life time expires. This
3907 * parameter can be used to avoid efforts to transmit stale
3908 * user messages. SCTP notifies the ULP if the data cannot be
3909 * initiated to transport (i.e. sent to the destination via SCTP's
3910 * send primitive) within the life time variable. However, the
3911 * user data will be transmitted if SCTP has attempted to transmit a
3912 * chunk before the life time expired.
3913 *
3914 * o destination transport address - specified as one of the destination
3915 * transport addresses of the peer endpoint to which this packet
3916 * should be sent. Whenever possible, SCTP should use this destination
3917 * transport address for sending the packets, instead of the current
3918 * primary path.
3919 *
3920 * o unorder flag - this flag, if present, indicates that the user
3921 * would like the data delivered in an unordered fashion to the peer
3922 * (i.e., the U flag is set to 1 on all DATA chunks carrying this
3923 * message).
3924 *
3925 * o no-bundle flag - instructs SCTP not to bundle this user data with
3926 * other outbound DATA chunks. SCTP MAY still bundle even when
3927 * this flag is present, when faced with network congestion.
3928 *
3929 * o payload protocol-id - A 32 bit unsigned integer that is to be
3930 * passed to the peer indicating the type of payload protocol data
3931 * being transmitted. This value is passed as opaque data by SCTP.
3932 *
3933 * The return value is the disposition.
3934 */
3935sctp_disposition_t sctp_sf_do_prm_send(const struct sctp_endpoint *ep,
3936 const struct sctp_association *asoc,
3937 const sctp_subtype_t type,
3938 void *arg,
3939 sctp_cmd_seq_t *commands)
3940{
3941 struct sctp_chunk *chunk = arg;
3942
3943 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
3944 return SCTP_DISPOSITION_CONSUME;
3945}
3946
3947/*
3948 * Process the SHUTDOWN primitive.
3949 *
3950 * Section: 10.1:
3951 * C) Shutdown
3952 *
3953 * Format: SHUTDOWN(association id)
3954 * -> result
3955 *
3956 * Gracefully closes an association. Any locally queued user data
3957 * will be delivered to the peer. The association will be terminated only
3958 * after the peer acknowledges all the SCTP packets sent. A success code
3959 * will be returned on successful termination of the association. If
3960 * attempting to terminate the association results in a failure, an error
3961 * code shall be returned.
3962 *
3963 * Mandatory attributes:
3964 *
3965 * o association id - local handle to the SCTP association
3966 *
3967 * Optional attributes:
3968 *
3969 * None.
3970 *
3971 * The return value is the disposition.
3972 */
3973sctp_disposition_t sctp_sf_do_9_2_prm_shutdown(
3974 const struct sctp_endpoint *ep,
3975 const struct sctp_association *asoc,
3976 const sctp_subtype_t type,
3977 void *arg,
3978 sctp_cmd_seq_t *commands)
3979{
3980 int disposition;
3981
3982 /* From 9.2 Shutdown of an Association
3983 * Upon receipt of the SHUTDOWN primitive from its upper
3984 * layer, the endpoint enters SHUTDOWN-PENDING state and
3985 * remains there until all outstanding data has been
3986 * acknowledged by its peer. The endpoint accepts no new data
3987 * from its upper layer, but retransmits data to the far end
3988 * if necessary to fill gaps.
3989 */
3990 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3991 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
3992
3993 /* sctpimpguide-05 Section 2.12.2
3994 * The sender of the SHUTDOWN MAY also start an overall guard timer
3995 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
3996 */
3997 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
3998 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
3999
4000 disposition = SCTP_DISPOSITION_CONSUME;
4001 if (sctp_outq_is_empty(&asoc->outqueue)) {
4002 disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type,
4003 arg, commands);
4004 }
4005 return disposition;
4006}
4007
4008/*
4009 * Process the ABORT primitive.
4010 *
4011 * Section: 10.1:
4012 * C) Abort
4013 *
4014 * Format: Abort(association id [, cause code])
4015 * -> result
4016 *
4017 * Ungracefully closes an association. Any locally queued user data
4018 * will be discarded and an ABORT chunk is sent to the peer. A success code
4019 * will be returned on successful abortion of the association. If
4020 * attempting to abort the association results in a failure, an error
4021 * code shall be returned.
4022 *
4023 * Mandatory attributes:
4024 *
4025 * o association id - local handle to the SCTP association
4026 *
4027 * Optional attributes:
4028 *
4029 * o cause code - reason of the abort to be passed to the peer
4030 *
4031 * None.
4032 *
4033 * The return value is the disposition.
4034 */
4035sctp_disposition_t sctp_sf_do_9_1_prm_abort(
4036 const struct sctp_endpoint *ep,
4037 const struct sctp_association *asoc,
4038 const sctp_subtype_t type,
4039 void *arg,
4040 sctp_cmd_seq_t *commands)
4041{
4042 /* From 9.1 Abort of an Association
4043 * Upon receipt of the ABORT primitive from its upper
4044 * layer, the endpoint enters CLOSED state and
4045 * discard all outstanding data has been
4046 * acknowledged by its peer. The endpoint accepts no new data
4047 * from its upper layer, but retransmits data to the far end
4048 * if necessary to fill gaps.
4049 */
Sridhar Samudralac164a9b2006-08-22 11:50:39 -07004050 struct sctp_chunk *abort = arg;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004051 sctp_disposition_t retval;
4052
4053 retval = SCTP_DISPOSITION_CONSUME;
4054
Sridhar Samudralac164a9b2006-08-22 11:50:39 -07004055 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004056
4057 /* Even if we can't send the ABORT due to low memory delete the
4058 * TCB. This is a departure from our typical NOMEM handling.
4059 */
4060
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004061 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4062 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004063 /* Delete the established association. */
4064 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08004065 SCTP_PERR(SCTP_ERROR_USER_ABORT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004066
4067 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4068 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
4069
4070 return retval;
4071}
4072
4073/* We tried an illegal operation on an association which is closed. */
4074sctp_disposition_t sctp_sf_error_closed(const struct sctp_endpoint *ep,
4075 const struct sctp_association *asoc,
4076 const sctp_subtype_t type,
4077 void *arg,
4078 sctp_cmd_seq_t *commands)
4079{
4080 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, SCTP_ERROR(-EINVAL));
4081 return SCTP_DISPOSITION_CONSUME;
4082}
4083
4084/* We tried an illegal operation on an association which is shutting
4085 * down.
4086 */
4087sctp_disposition_t sctp_sf_error_shutdown(const struct sctp_endpoint *ep,
4088 const struct sctp_association *asoc,
4089 const sctp_subtype_t type,
4090 void *arg,
4091 sctp_cmd_seq_t *commands)
4092{
4093 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR,
4094 SCTP_ERROR(-ESHUTDOWN));
4095 return SCTP_DISPOSITION_CONSUME;
4096}
4097
4098/*
4099 * sctp_cookie_wait_prm_shutdown
4100 *
4101 * Section: 4 Note: 2
4102 * Verification Tag:
4103 * Inputs
4104 * (endpoint, asoc)
4105 *
4106 * The RFC does not explicitly address this issue, but is the route through the
4107 * state table when someone issues a shutdown while in COOKIE_WAIT state.
4108 *
4109 * Outputs
4110 * (timers)
4111 */
4112sctp_disposition_t sctp_sf_cookie_wait_prm_shutdown(
4113 const struct sctp_endpoint *ep,
4114 const struct sctp_association *asoc,
4115 const sctp_subtype_t type,
4116 void *arg,
4117 sctp_cmd_seq_t *commands)
4118{
4119 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4120 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4121
4122 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4123 SCTP_STATE(SCTP_STATE_CLOSED));
4124
4125 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
4126
4127 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
4128
4129 return SCTP_DISPOSITION_DELETE_TCB;
4130}
4131
4132/*
4133 * sctp_cookie_echoed_prm_shutdown
4134 *
4135 * Section: 4 Note: 2
4136 * Verification Tag:
4137 * Inputs
4138 * (endpoint, asoc)
4139 *
4140 * The RFC does not explcitly address this issue, but is the route through the
4141 * state table when someone issues a shutdown while in COOKIE_ECHOED state.
4142 *
4143 * Outputs
4144 * (timers)
4145 */
4146sctp_disposition_t sctp_sf_cookie_echoed_prm_shutdown(
4147 const struct sctp_endpoint *ep,
4148 const struct sctp_association *asoc,
4149 const sctp_subtype_t type,
4150 void *arg, sctp_cmd_seq_t *commands)
4151{
4152 /* There is a single T1 timer, so we should be able to use
4153 * common function with the COOKIE-WAIT state.
4154 */
4155 return sctp_sf_cookie_wait_prm_shutdown(ep, asoc, type, arg, commands);
4156}
4157
4158/*
4159 * sctp_sf_cookie_wait_prm_abort
4160 *
4161 * Section: 4 Note: 2
4162 * Verification Tag:
4163 * Inputs
4164 * (endpoint, asoc)
4165 *
4166 * The RFC does not explicitly address this issue, but is the route through the
4167 * state table when someone issues an abort while in COOKIE_WAIT state.
4168 *
4169 * Outputs
4170 * (timers)
4171 */
4172sctp_disposition_t sctp_sf_cookie_wait_prm_abort(
4173 const struct sctp_endpoint *ep,
4174 const struct sctp_association *asoc,
4175 const sctp_subtype_t type,
4176 void *arg,
4177 sctp_cmd_seq_t *commands)
4178{
Sridhar Samudralac164a9b2006-08-22 11:50:39 -07004179 struct sctp_chunk *abort = arg;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004180 sctp_disposition_t retval;
4181
4182 /* Stop T1-init timer */
4183 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4184 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4185 retval = SCTP_DISPOSITION_CONSUME;
4186
Sridhar Samudralac164a9b2006-08-22 11:50:39 -07004187 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004188
4189 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4190 SCTP_STATE(SCTP_STATE_CLOSED));
4191
4192 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4193
4194 /* Even if we can't send the ABORT due to low memory delete the
4195 * TCB. This is a departure from our typical NOMEM handling.
4196 */
4197
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004198 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4199 SCTP_ERROR(ECONNREFUSED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004200 /* Delete the established association. */
4201 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08004202 SCTP_PERR(SCTP_ERROR_USER_ABORT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004203
4204 return retval;
4205}
4206
4207/*
4208 * sctp_sf_cookie_echoed_prm_abort
4209 *
4210 * Section: 4 Note: 3
4211 * Verification Tag:
4212 * Inputs
4213 * (endpoint, asoc)
4214 *
4215 * The RFC does not explcitly address this issue, but is the route through the
4216 * state table when someone issues an abort while in COOKIE_ECHOED state.
4217 *
4218 * Outputs
4219 * (timers)
4220 */
4221sctp_disposition_t sctp_sf_cookie_echoed_prm_abort(
4222 const struct sctp_endpoint *ep,
4223 const struct sctp_association *asoc,
4224 const sctp_subtype_t type,
4225 void *arg,
4226 sctp_cmd_seq_t *commands)
4227{
4228 /* There is a single T1 timer, so we should be able to use
4229 * common function with the COOKIE-WAIT state.
4230 */
4231 return sctp_sf_cookie_wait_prm_abort(ep, asoc, type, arg, commands);
4232}
4233
4234/*
4235 * sctp_sf_shutdown_pending_prm_abort
4236 *
4237 * Inputs
4238 * (endpoint, asoc)
4239 *
4240 * The RFC does not explicitly address this issue, but is the route through the
4241 * state table when someone issues an abort while in SHUTDOWN-PENDING state.
4242 *
4243 * Outputs
4244 * (timers)
4245 */
4246sctp_disposition_t sctp_sf_shutdown_pending_prm_abort(
4247 const struct sctp_endpoint *ep,
4248 const struct sctp_association *asoc,
4249 const sctp_subtype_t type,
4250 void *arg,
4251 sctp_cmd_seq_t *commands)
4252{
4253 /* Stop the T5-shutdown guard timer. */
4254 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4255 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4256
4257 return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands);
4258}
4259
4260/*
4261 * sctp_sf_shutdown_sent_prm_abort
4262 *
4263 * Inputs
4264 * (endpoint, asoc)
4265 *
4266 * The RFC does not explicitly address this issue, but is the route through the
4267 * state table when someone issues an abort while in SHUTDOWN-SENT state.
4268 *
4269 * Outputs
4270 * (timers)
4271 */
4272sctp_disposition_t sctp_sf_shutdown_sent_prm_abort(
4273 const struct sctp_endpoint *ep,
4274 const struct sctp_association *asoc,
4275 const sctp_subtype_t type,
4276 void *arg,
4277 sctp_cmd_seq_t *commands)
4278{
4279 /* Stop the T2-shutdown timer. */
4280 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4281 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4282
4283 /* Stop the T5-shutdown guard timer. */
4284 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4285 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4286
4287 return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands);
4288}
4289
4290/*
4291 * sctp_sf_cookie_echoed_prm_abort
4292 *
4293 * Inputs
4294 * (endpoint, asoc)
4295 *
4296 * The RFC does not explcitly address this issue, but is the route through the
4297 * state table when someone issues an abort while in COOKIE_ECHOED state.
4298 *
4299 * Outputs
4300 * (timers)
4301 */
4302sctp_disposition_t sctp_sf_shutdown_ack_sent_prm_abort(
4303 const struct sctp_endpoint *ep,
4304 const struct sctp_association *asoc,
4305 const sctp_subtype_t type,
4306 void *arg,
4307 sctp_cmd_seq_t *commands)
4308{
4309 /* The same T2 timer, so we should be able to use
4310 * common function with the SHUTDOWN-SENT state.
4311 */
4312 return sctp_sf_shutdown_sent_prm_abort(ep, asoc, type, arg, commands);
4313}
4314
4315/*
4316 * Process the REQUESTHEARTBEAT primitive
4317 *
4318 * 10.1 ULP-to-SCTP
4319 * J) Request Heartbeat
4320 *
4321 * Format: REQUESTHEARTBEAT(association id, destination transport address)
4322 *
4323 * -> result
4324 *
4325 * Instructs the local endpoint to perform a HeartBeat on the specified
4326 * destination transport address of the given association. The returned
4327 * result should indicate whether the transmission of the HEARTBEAT
4328 * chunk to the destination address is successful.
4329 *
4330 * Mandatory attributes:
4331 *
4332 * o association id - local handle to the SCTP association
4333 *
4334 * o destination transport address - the transport address of the
4335 * association on which a heartbeat should be issued.
4336 */
4337sctp_disposition_t sctp_sf_do_prm_requestheartbeat(
4338 const struct sctp_endpoint *ep,
4339 const struct sctp_association *asoc,
4340 const sctp_subtype_t type,
4341 void *arg,
4342 sctp_cmd_seq_t *commands)
4343{
4344 return sctp_sf_heartbeat(ep, asoc, type, (struct sctp_transport *)arg,
4345 commands);
4346}
4347
4348/*
4349 * ADDIP Section 4.1 ASCONF Chunk Procedures
4350 * When an endpoint has an ASCONF signaled change to be sent to the
4351 * remote endpoint it should do A1 to A9
4352 */
4353sctp_disposition_t sctp_sf_do_prm_asconf(const struct sctp_endpoint *ep,
4354 const struct sctp_association *asoc,
4355 const sctp_subtype_t type,
4356 void *arg,
4357 sctp_cmd_seq_t *commands)
4358{
4359 struct sctp_chunk *chunk = arg;
4360
4361 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
4362 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4363 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
4364 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
4365 return SCTP_DISPOSITION_CONSUME;
4366}
4367
4368/*
4369 * Ignore the primitive event
4370 *
4371 * The return value is the disposition of the primitive.
4372 */
4373sctp_disposition_t sctp_sf_ignore_primitive(
4374 const struct sctp_endpoint *ep,
4375 const struct sctp_association *asoc,
4376 const sctp_subtype_t type,
4377 void *arg,
4378 sctp_cmd_seq_t *commands)
4379{
4380 SCTP_DEBUG_PRINTK("Primitive type %d is ignored.\n", type.primitive);
4381 return SCTP_DISPOSITION_DISCARD;
4382}
4383
4384/***************************************************************************
4385 * These are the state functions for the OTHER events.
4386 ***************************************************************************/
4387
4388/*
4389 * Start the shutdown negotiation.
4390 *
4391 * From Section 9.2:
4392 * Once all its outstanding data has been acknowledged, the endpoint
4393 * shall send a SHUTDOWN chunk to its peer including in the Cumulative
4394 * TSN Ack field the last sequential TSN it has received from the peer.
4395 * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT
4396 * state. If the timer expires, the endpoint must re-send the SHUTDOWN
4397 * with the updated last sequential TSN received from its peer.
4398 *
4399 * The return value is the disposition.
4400 */
4401sctp_disposition_t sctp_sf_do_9_2_start_shutdown(
4402 const struct sctp_endpoint *ep,
4403 const struct sctp_association *asoc,
4404 const sctp_subtype_t type,
4405 void *arg,
4406 sctp_cmd_seq_t *commands)
4407{
4408 struct sctp_chunk *reply;
4409
4410 /* Once all its outstanding data has been acknowledged, the
4411 * endpoint shall send a SHUTDOWN chunk to its peer including
4412 * in the Cumulative TSN Ack field the last sequential TSN it
4413 * has received from the peer.
4414 */
4415 reply = sctp_make_shutdown(asoc, NULL);
4416 if (!reply)
4417 goto nomem;
4418
4419 /* Set the transport for the SHUTDOWN chunk and the timeout for the
4420 * T2-shutdown timer.
4421 */
4422 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
4423
4424 /* It shall then start the T2-shutdown timer */
4425 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4426 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4427
4428 if (asoc->autoclose)
4429 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4430 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
4431
4432 /* and enter the SHUTDOWN-SENT state. */
4433 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4434 SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT));
4435
4436 /* sctp-implguide 2.10 Issues with Heartbeating and failover
4437 *
4438 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
4439 * or SHUTDOWN-ACK.
4440 */
4441 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
4442
4443 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
4444
4445 return SCTP_DISPOSITION_CONSUME;
4446
4447nomem:
4448 return SCTP_DISPOSITION_NOMEM;
4449}
4450
4451/*
4452 * Generate a SHUTDOWN ACK now that everything is SACK'd.
4453 *
4454 * From Section 9.2:
4455 *
4456 * If it has no more outstanding DATA chunks, the SHUTDOWN receiver
4457 * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own,
4458 * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the
4459 * endpoint must re-send the SHUTDOWN ACK.
4460 *
4461 * The return value is the disposition.
4462 */
4463sctp_disposition_t sctp_sf_do_9_2_shutdown_ack(
4464 const struct sctp_endpoint *ep,
4465 const struct sctp_association *asoc,
4466 const sctp_subtype_t type,
4467 void *arg,
4468 sctp_cmd_seq_t *commands)
4469{
4470 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
4471 struct sctp_chunk *reply;
4472
4473 /* There are 2 ways of getting here:
4474 * 1) called in response to a SHUTDOWN chunk
4475 * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued.
4476 *
4477 * For the case (2), the arg parameter is set to NULL. We need
4478 * to check that we have a chunk before accessing it's fields.
4479 */
4480 if (chunk) {
4481 if (!sctp_vtag_verify(chunk, asoc))
4482 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
4483
4484 /* Make sure that the SHUTDOWN chunk has a valid length. */
4485 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_shutdown_chunk_t)))
4486 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
4487 commands);
4488 }
4489
4490 /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
4491 * shall send a SHUTDOWN ACK ...
4492 */
4493 reply = sctp_make_shutdown_ack(asoc, chunk);
4494 if (!reply)
4495 goto nomem;
4496
4497 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
4498 * the T2-shutdown timer.
4499 */
4500 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
4501
4502 /* and start/restart a T2-shutdown timer of its own, */
4503 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
4504 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4505
4506 if (asoc->autoclose)
4507 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4508 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
4509
4510 /* Enter the SHUTDOWN-ACK-SENT state. */
4511 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4512 SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT));
4513
4514 /* sctp-implguide 2.10 Issues with Heartbeating and failover
4515 *
4516 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
4517 * or SHUTDOWN-ACK.
4518 */
4519 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
4520
4521 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
4522
4523 return SCTP_DISPOSITION_CONSUME;
4524
4525nomem:
4526 return SCTP_DISPOSITION_NOMEM;
4527}
4528
4529/*
4530 * Ignore the event defined as other
4531 *
4532 * The return value is the disposition of the event.
4533 */
4534sctp_disposition_t sctp_sf_ignore_other(const struct sctp_endpoint *ep,
4535 const struct sctp_association *asoc,
4536 const sctp_subtype_t type,
4537 void *arg,
4538 sctp_cmd_seq_t *commands)
4539{
4540 SCTP_DEBUG_PRINTK("The event other type %d is ignored\n", type.other);
4541 return SCTP_DISPOSITION_DISCARD;
4542}
4543
4544/************************************************************
4545 * These are the state functions for handling timeout events.
4546 ************************************************************/
4547
4548/*
4549 * RTX Timeout
4550 *
4551 * Section: 6.3.3 Handle T3-rtx Expiration
4552 *
4553 * Whenever the retransmission timer T3-rtx expires for a destination
4554 * address, do the following:
4555 * [See below]
4556 *
4557 * The return value is the disposition of the chunk.
4558 */
4559sctp_disposition_t sctp_sf_do_6_3_3_rtx(const struct sctp_endpoint *ep,
4560 const struct sctp_association *asoc,
4561 const sctp_subtype_t type,
4562 void *arg,
4563 sctp_cmd_seq_t *commands)
4564{
4565 struct sctp_transport *transport = arg;
4566
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07004567 SCTP_INC_STATS(SCTP_MIB_T3_RTX_EXPIREDS);
4568
Linus Torvalds1da177e2005-04-16 15:20:36 -07004569 if (asoc->overall_error_count >= asoc->max_retrans) {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004570 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4571 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004572 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
4573 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08004574 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004575 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4576 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
4577 return SCTP_DISPOSITION_DELETE_TCB;
4578 }
4579
4580 /* E1) For the destination address for which the timer
4581 * expires, adjust its ssthresh with rules defined in Section
4582 * 7.2.3 and set the cwnd <- MTU.
4583 */
4584
4585 /* E2) For the destination address for which the timer
4586 * expires, set RTO <- RTO * 2 ("back off the timer"). The
4587 * maximum value discussed in rule C7 above (RTO.max) may be
4588 * used to provide an upper bound to this doubling operation.
4589 */
4590
4591 /* E3) Determine how many of the earliest (i.e., lowest TSN)
4592 * outstanding DATA chunks for the address for which the
4593 * T3-rtx has expired will fit into a single packet, subject
4594 * to the MTU constraint for the path corresponding to the
4595 * destination transport address to which the retransmission
4596 * is being sent (this may be different from the address for
4597 * which the timer expires [see Section 6.4]). Call this
4598 * value K. Bundle and retransmit those K DATA chunks in a
4599 * single packet to the destination endpoint.
4600 *
4601 * Note: Any DATA chunks that were sent to the address for
4602 * which the T3-rtx timer expired but did not fit in one MTU
4603 * (rule E3 above), should be marked for retransmission and
4604 * sent as soon as cwnd allows (normally when a SACK arrives).
4605 */
4606
4607 /* NB: Rules E4 and F1 are implicit in R1. */
4608 sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN, SCTP_TRANSPORT(transport));
4609
4610 /* Do some failure management (Section 8.2). */
4611 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
4612
4613 return SCTP_DISPOSITION_CONSUME;
4614}
4615
4616/*
4617 * Generate delayed SACK on timeout
4618 *
4619 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
4620 *
4621 * The guidelines on delayed acknowledgement algorithm specified in
4622 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
4623 * acknowledgement SHOULD be generated for at least every second packet
4624 * (not every second DATA chunk) received, and SHOULD be generated
4625 * within 200 ms of the arrival of any unacknowledged DATA chunk. In
4626 * some situations it may be beneficial for an SCTP transmitter to be
4627 * more conservative than the algorithms detailed in this document
4628 * allow. However, an SCTP transmitter MUST NOT be more aggressive than
4629 * the following algorithms allow.
4630 */
4631sctp_disposition_t sctp_sf_do_6_2_sack(const struct sctp_endpoint *ep,
4632 const struct sctp_association *asoc,
4633 const sctp_subtype_t type,
4634 void *arg,
4635 sctp_cmd_seq_t *commands)
4636{
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07004637 SCTP_INC_STATS(SCTP_MIB_DELAY_SACK_EXPIREDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004638 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
4639 return SCTP_DISPOSITION_CONSUME;
4640}
4641
4642/*
Frank Filz3f7a87d2005-06-20 13:14:57 -07004643 * sctp_sf_t1_init_timer_expire
Linus Torvalds1da177e2005-04-16 15:20:36 -07004644 *
4645 * Section: 4 Note: 2
4646 * Verification Tag:
4647 * Inputs
4648 * (endpoint, asoc)
4649 *
4650 * RFC 2960 Section 4 Notes
4651 * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT
4652 * and re-start the T1-init timer without changing state. This MUST
4653 * be repeated up to 'Max.Init.Retransmits' times. After that, the
4654 * endpoint MUST abort the initialization process and report the
4655 * error to SCTP user.
4656 *
Frank Filz3f7a87d2005-06-20 13:14:57 -07004657 * Outputs
4658 * (timers, events)
4659 *
4660 */
4661sctp_disposition_t sctp_sf_t1_init_timer_expire(const struct sctp_endpoint *ep,
4662 const struct sctp_association *asoc,
4663 const sctp_subtype_t type,
4664 void *arg,
4665 sctp_cmd_seq_t *commands)
4666{
4667 struct sctp_chunk *repl = NULL;
4668 struct sctp_bind_addr *bp;
4669 int attempts = asoc->init_err_counter + 1;
4670
4671 SCTP_DEBUG_PRINTK("Timer T1 expired (INIT).\n");
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07004672 SCTP_INC_STATS(SCTP_MIB_T1_INIT_EXPIREDS);
Frank Filz3f7a87d2005-06-20 13:14:57 -07004673
Vlad Yasevich81845c22006-01-30 15:59:54 -08004674 if (attempts <= asoc->max_init_attempts) {
Frank Filz3f7a87d2005-06-20 13:14:57 -07004675 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
4676 repl = sctp_make_init(asoc, bp, GFP_ATOMIC, 0);
4677 if (!repl)
4678 return SCTP_DISPOSITION_NOMEM;
4679
4680 /* Choose transport for INIT. */
4681 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
4682 SCTP_CHUNK(repl));
4683
4684 /* Issue a sideeffect to do the needed accounting. */
4685 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_RESTART,
4686 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4687
4688 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
4689 } else {
4690 SCTP_DEBUG_PRINTK("Giving up on INIT, attempts: %d"
4691 " max_init_attempts: %d\n",
4692 attempts, asoc->max_init_attempts);
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004693 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4694 SCTP_ERROR(ETIMEDOUT));
Frank Filz3f7a87d2005-06-20 13:14:57 -07004695 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08004696 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Frank Filz3f7a87d2005-06-20 13:14:57 -07004697 return SCTP_DISPOSITION_DELETE_TCB;
4698 }
4699
4700 return SCTP_DISPOSITION_CONSUME;
4701}
4702
4703/*
4704 * sctp_sf_t1_cookie_timer_expire
4705 *
4706 * Section: 4 Note: 2
4707 * Verification Tag:
4708 * Inputs
4709 * (endpoint, asoc)
4710 *
4711 * RFC 2960 Section 4 Notes
4712 * 3) If the T1-cookie timer expires, the endpoint MUST retransmit
Linus Torvalds1da177e2005-04-16 15:20:36 -07004713 * COOKIE ECHO and re-start the T1-cookie timer without changing
4714 * state. This MUST be repeated up to 'Max.Init.Retransmits' times.
4715 * After that, the endpoint MUST abort the initialization process and
4716 * report the error to SCTP user.
4717 *
4718 * Outputs
4719 * (timers, events)
4720 *
4721 */
Frank Filz3f7a87d2005-06-20 13:14:57 -07004722sctp_disposition_t sctp_sf_t1_cookie_timer_expire(const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07004723 const struct sctp_association *asoc,
4724 const sctp_subtype_t type,
4725 void *arg,
4726 sctp_cmd_seq_t *commands)
4727{
Frank Filz3f7a87d2005-06-20 13:14:57 -07004728 struct sctp_chunk *repl = NULL;
4729 int attempts = asoc->init_err_counter + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004730
Frank Filz3f7a87d2005-06-20 13:14:57 -07004731 SCTP_DEBUG_PRINTK("Timer T1 expired (COOKIE-ECHO).\n");
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07004732 SCTP_INC_STATS(SCTP_MIB_T1_COOKIE_EXPIREDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004733
Vlad Yasevich81845c22006-01-30 15:59:54 -08004734 if (attempts <= asoc->max_init_attempts) {
Frank Filz3f7a87d2005-06-20 13:14:57 -07004735 repl = sctp_make_cookie_echo(asoc, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004736 if (!repl)
Frank Filz3f7a87d2005-06-20 13:14:57 -07004737 return SCTP_DISPOSITION_NOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004738
4739 /* Issue a sideeffect to do the needed accounting. */
Frank Filz3f7a87d2005-06-20 13:14:57 -07004740 sctp_add_cmd_sf(commands, SCTP_CMD_COOKIEECHO_RESTART,
4741 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
4742
Linus Torvalds1da177e2005-04-16 15:20:36 -07004743 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
4744 } else {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004745 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4746 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004747 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
Al Virodc251b22006-11-20 17:00:44 -08004748 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004749 return SCTP_DISPOSITION_DELETE_TCB;
4750 }
4751
4752 return SCTP_DISPOSITION_CONSUME;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004753}
4754
4755/* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN
4756 * with the updated last sequential TSN received from its peer.
4757 *
4758 * An endpoint should limit the number of retransmissions of the
4759 * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'.
4760 * If this threshold is exceeded the endpoint should destroy the TCB and
4761 * MUST report the peer endpoint unreachable to the upper layer (and
4762 * thus the association enters the CLOSED state). The reception of any
4763 * packet from its peer (i.e. as the peer sends all of its queued DATA
4764 * chunks) should clear the endpoint's retransmission count and restart
4765 * the T2-Shutdown timer, giving its peer ample opportunity to transmit
4766 * all of its queued DATA chunks that have not yet been sent.
4767 */
4768sctp_disposition_t sctp_sf_t2_timer_expire(const struct sctp_endpoint *ep,
4769 const struct sctp_association *asoc,
4770 const sctp_subtype_t type,
4771 void *arg,
4772 sctp_cmd_seq_t *commands)
4773{
4774 struct sctp_chunk *reply = NULL;
4775
4776 SCTP_DEBUG_PRINTK("Timer T2 expired.\n");
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07004777 SCTP_INC_STATS(SCTP_MIB_T2_SHUTDOWN_EXPIREDS);
4778
Linus Torvalds1da177e2005-04-16 15:20:36 -07004779 if (asoc->overall_error_count >= asoc->max_retrans) {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004780 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4781 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004782 /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
4783 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08004784 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004785 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4786 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
4787 return SCTP_DISPOSITION_DELETE_TCB;
4788 }
4789
4790 switch (asoc->state) {
4791 case SCTP_STATE_SHUTDOWN_SENT:
4792 reply = sctp_make_shutdown(asoc, NULL);
4793 break;
4794
4795 case SCTP_STATE_SHUTDOWN_ACK_SENT:
4796 reply = sctp_make_shutdown_ack(asoc, NULL);
4797 break;
4798
4799 default:
4800 BUG();
4801 break;
4802 };
4803
4804 if (!reply)
4805 goto nomem;
4806
4807 /* Do some failure management (Section 8.2). */
4808 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
4809 SCTP_TRANSPORT(asoc->shutdown_last_sent_to));
4810
4811 /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for
4812 * the T2-shutdown timer.
4813 */
4814 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
4815
4816 /* Restart the T2-shutdown timer. */
4817 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
4818 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4819 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
4820 return SCTP_DISPOSITION_CONSUME;
4821
4822nomem:
4823 return SCTP_DISPOSITION_NOMEM;
4824}
4825
4826/*
4827 * ADDIP Section 4.1 ASCONF CHunk Procedures
4828 * If the T4 RTO timer expires the endpoint should do B1 to B5
4829 */
4830sctp_disposition_t sctp_sf_t4_timer_expire(
4831 const struct sctp_endpoint *ep,
4832 const struct sctp_association *asoc,
4833 const sctp_subtype_t type,
4834 void *arg,
4835 sctp_cmd_seq_t *commands)
4836{
4837 struct sctp_chunk *chunk = asoc->addip_last_asconf;
4838 struct sctp_transport *transport = chunk->transport;
4839
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07004840 SCTP_INC_STATS(SCTP_MIB_T4_RTO_EXPIREDS);
4841
Linus Torvalds1da177e2005-04-16 15:20:36 -07004842 /* ADDIP 4.1 B1) Increment the error counters and perform path failure
4843 * detection on the appropriate destination address as defined in
4844 * RFC2960 [5] section 8.1 and 8.2.
4845 */
4846 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
4847
4848 /* Reconfig T4 timer and transport. */
4849 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
4850
4851 /* ADDIP 4.1 B2) Increment the association error counters and perform
4852 * endpoint failure detection on the association as defined in
4853 * RFC2960 [5] section 8.1 and 8.2.
4854 * association error counter is incremented in SCTP_CMD_STRIKE.
4855 */
4856 if (asoc->overall_error_count >= asoc->max_retrans) {
4857 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4858 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004859 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4860 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004861 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08004862 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004863 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4864 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
4865 return SCTP_DISPOSITION_ABORT;
4866 }
4867
4868 /* ADDIP 4.1 B3) Back-off the destination address RTO value to which
4869 * the ASCONF chunk was sent by doubling the RTO timer value.
4870 * This is done in SCTP_CMD_STRIKE.
4871 */
4872
4873 /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible
4874 * choose an alternate destination address (please refer to RFC2960
4875 * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this
4876 * chunk, it MUST be the same (including its serial number) as the last
4877 * ASCONF sent.
4878 */
4879 sctp_chunk_hold(asoc->addip_last_asconf);
4880 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4881 SCTP_CHUNK(asoc->addip_last_asconf));
4882
4883 /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different
4884 * destination is selected, then the RTO used will be that of the new
4885 * destination address.
4886 */
4887 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
4888 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
4889
4890 return SCTP_DISPOSITION_CONSUME;
4891}
4892
4893/* sctpimpguide-05 Section 2.12.2
4894 * The sender of the SHUTDOWN MAY also start an overall guard timer
4895 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
4896 * At the expiration of this timer the sender SHOULD abort the association
4897 * by sending an ABORT chunk.
4898 */
4899sctp_disposition_t sctp_sf_t5_timer_expire(const struct sctp_endpoint *ep,
4900 const struct sctp_association *asoc,
4901 const sctp_subtype_t type,
4902 void *arg,
4903 sctp_cmd_seq_t *commands)
4904{
4905 struct sctp_chunk *reply = NULL;
4906
4907 SCTP_DEBUG_PRINTK("Timer T5 expired.\n");
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07004908 SCTP_INC_STATS(SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004909
4910 reply = sctp_make_abort(asoc, NULL, 0);
4911 if (!reply)
4912 goto nomem;
4913
4914 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004915 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4916 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004917 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08004918 SCTP_PERR(SCTP_ERROR_NO_ERROR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004919
4920 return SCTP_DISPOSITION_DELETE_TCB;
4921nomem:
4922 return SCTP_DISPOSITION_NOMEM;
4923}
4924
4925/* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires,
4926 * the association is automatically closed by starting the shutdown process.
4927 * The work that needs to be done is same as when SHUTDOWN is initiated by
4928 * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown().
4929 */
4930sctp_disposition_t sctp_sf_autoclose_timer_expire(
4931 const struct sctp_endpoint *ep,
4932 const struct sctp_association *asoc,
4933 const sctp_subtype_t type,
4934 void *arg,
4935 sctp_cmd_seq_t *commands)
4936{
4937 int disposition;
4938
Sridhar Samudralaac0b0462006-08-22 00:15:33 -07004939 SCTP_INC_STATS(SCTP_MIB_AUTOCLOSE_EXPIREDS);
4940
Linus Torvalds1da177e2005-04-16 15:20:36 -07004941 /* From 9.2 Shutdown of an Association
4942 * Upon receipt of the SHUTDOWN primitive from its upper
4943 * layer, the endpoint enters SHUTDOWN-PENDING state and
4944 * remains there until all outstanding data has been
4945 * acknowledged by its peer. The endpoint accepts no new data
4946 * from its upper layer, but retransmits data to the far end
4947 * if necessary to fill gaps.
4948 */
4949 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4950 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
4951
4952 /* sctpimpguide-05 Section 2.12.2
4953 * The sender of the SHUTDOWN MAY also start an overall guard timer
4954 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
4955 */
4956 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4957 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4958 disposition = SCTP_DISPOSITION_CONSUME;
4959 if (sctp_outq_is_empty(&asoc->outqueue)) {
4960 disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type,
4961 arg, commands);
4962 }
4963 return disposition;
4964}
4965
4966/*****************************************************************************
4967 * These are sa state functions which could apply to all types of events.
4968 ****************************************************************************/
4969
4970/*
4971 * This table entry is not implemented.
4972 *
4973 * Inputs
4974 * (endpoint, asoc, chunk)
4975 *
4976 * The return value is the disposition of the chunk.
4977 */
4978sctp_disposition_t sctp_sf_not_impl(const struct sctp_endpoint *ep,
4979 const struct sctp_association *asoc,
4980 const sctp_subtype_t type,
4981 void *arg,
4982 sctp_cmd_seq_t *commands)
4983{
4984 return SCTP_DISPOSITION_NOT_IMPL;
4985}
4986
4987/*
4988 * This table entry represents a bug.
4989 *
4990 * Inputs
4991 * (endpoint, asoc, chunk)
4992 *
4993 * The return value is the disposition of the chunk.
4994 */
4995sctp_disposition_t sctp_sf_bug(const struct sctp_endpoint *ep,
4996 const struct sctp_association *asoc,
4997 const sctp_subtype_t type,
4998 void *arg,
4999 sctp_cmd_seq_t *commands)
5000{
5001 return SCTP_DISPOSITION_BUG;
5002}
5003
5004/*
5005 * This table entry represents the firing of a timer in the wrong state.
5006 * Since timer deletion cannot be guaranteed a timer 'may' end up firing
5007 * when the association is in the wrong state. This event should
5008 * be ignored, so as to prevent any rearming of the timer.
5009 *
5010 * Inputs
5011 * (endpoint, asoc, chunk)
5012 *
5013 * The return value is the disposition of the chunk.
5014 */
5015sctp_disposition_t sctp_sf_timer_ignore(const struct sctp_endpoint *ep,
5016 const struct sctp_association *asoc,
5017 const sctp_subtype_t type,
5018 void *arg,
5019 sctp_cmd_seq_t *commands)
5020{
5021 SCTP_DEBUG_PRINTK("Timer %d ignored.\n", type.chunk);
5022 return SCTP_DISPOSITION_CONSUME;
5023}
5024
5025/********************************************************************
5026 * 2nd Level Abstractions
5027 ********************************************************************/
5028
5029/* Pull the SACK chunk based on the SACK header. */
5030static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk)
5031{
5032 struct sctp_sackhdr *sack;
5033 unsigned int len;
5034 __u16 num_blocks;
5035 __u16 num_dup_tsns;
5036
5037 /* Protect ourselves from reading too far into
5038 * the skb from a bogus sender.
5039 */
5040 sack = (struct sctp_sackhdr *) chunk->skb->data;
5041
5042 num_blocks = ntohs(sack->num_gap_ack_blocks);
5043 num_dup_tsns = ntohs(sack->num_dup_tsns);
5044 len = sizeof(struct sctp_sackhdr);
5045 len += (num_blocks + num_dup_tsns) * sizeof(__u32);
5046 if (len > chunk->skb->len)
5047 return NULL;
5048
5049 skb_pull(chunk->skb, len);
5050
5051 return sack;
5052}
5053
5054/* Create an ABORT packet to be sent as a response, with the specified
5055 * error causes.
5056 */
5057static struct sctp_packet *sctp_abort_pkt_new(const struct sctp_endpoint *ep,
5058 const struct sctp_association *asoc,
5059 struct sctp_chunk *chunk,
5060 const void *payload,
5061 size_t paylen)
5062{
5063 struct sctp_packet *packet;
5064 struct sctp_chunk *abort;
5065
5066 packet = sctp_ootb_pkt_new(asoc, chunk);
5067
5068 if (packet) {
5069 /* Make an ABORT.
5070 * The T bit will be set if the asoc is NULL.
5071 */
5072 abort = sctp_make_abort(asoc, chunk, paylen);
5073 if (!abort) {
5074 sctp_ootb_pkt_free(packet);
5075 return NULL;
5076 }
Jerome Forissier047a2422005-04-28 11:58:43 -07005077
5078 /* Reflect vtag if T-Bit is set */
5079 if (sctp_test_T_bit(abort))
5080 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
5081
Linus Torvalds1da177e2005-04-16 15:20:36 -07005082 /* Add specified error causes, i.e., payload, to the
5083 * end of the chunk.
5084 */
5085 sctp_addto_chunk(abort, paylen, payload);
5086
5087 /* Set the skb to the belonging sock for accounting. */
5088 abort->skb->sk = ep->base.sk;
5089
5090 sctp_packet_append_chunk(packet, abort);
5091
5092 }
5093
5094 return packet;
5095}
5096
5097/* Allocate a packet for responding in the OOTB conditions. */
5098static struct sctp_packet *sctp_ootb_pkt_new(const struct sctp_association *asoc,
5099 const struct sctp_chunk *chunk)
5100{
5101 struct sctp_packet *packet;
5102 struct sctp_transport *transport;
5103 __u16 sport;
5104 __u16 dport;
5105 __u32 vtag;
5106
5107 /* Get the source and destination port from the inbound packet. */
5108 sport = ntohs(chunk->sctp_hdr->dest);
5109 dport = ntohs(chunk->sctp_hdr->source);
5110
5111 /* The V-tag is going to be the same as the inbound packet if no
5112 * association exists, otherwise, use the peer's vtag.
5113 */
5114 if (asoc) {
5115 vtag = asoc->peer.i.init_tag;
5116 } else {
5117 /* Special case the INIT and stale COOKIE_ECHO as there is no
5118 * vtag yet.
5119 */
5120 switch(chunk->chunk_hdr->type) {
5121 case SCTP_CID_INIT:
5122 {
5123 sctp_init_chunk_t *init;
5124
5125 init = (sctp_init_chunk_t *)chunk->chunk_hdr;
5126 vtag = ntohl(init->init_hdr.init_tag);
5127 break;
5128 }
5129 default:
5130 vtag = ntohl(chunk->sctp_hdr->vtag);
5131 break;
5132 }
5133 }
5134
5135 /* Make a transport for the bucket, Eliza... */
Al Viro6a1e5f32006-11-20 17:12:25 -08005136 transport = sctp_transport_new(sctp_source(chunk), GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07005137 if (!transport)
5138 goto nomem;
5139
5140 /* Cache a route for the transport with the chunk's destination as
5141 * the source address.
5142 */
Al Viro16b0a032006-11-20 17:13:38 -08005143 sctp_transport_route(transport, (union sctp_addr *)&chunk->dest,
Linus Torvalds1da177e2005-04-16 15:20:36 -07005144 sctp_sk(sctp_get_ctl_sock()));
5145
5146 packet = sctp_packet_init(&transport->packet, transport, sport, dport);
5147 packet = sctp_packet_config(packet, vtag, 0);
5148
5149 return packet;
5150
5151nomem:
5152 return NULL;
5153}
5154
5155/* Free the packet allocated earlier for responding in the OOTB condition. */
5156void sctp_ootb_pkt_free(struct sctp_packet *packet)
5157{
5158 sctp_transport_free(packet->transport);
5159}
5160
5161/* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */
5162static void sctp_send_stale_cookie_err(const struct sctp_endpoint *ep,
5163 const struct sctp_association *asoc,
5164 const struct sctp_chunk *chunk,
5165 sctp_cmd_seq_t *commands,
5166 struct sctp_chunk *err_chunk)
5167{
5168 struct sctp_packet *packet;
5169
5170 if (err_chunk) {
5171 packet = sctp_ootb_pkt_new(asoc, chunk);
5172 if (packet) {
5173 struct sctp_signed_cookie *cookie;
5174
5175 /* Override the OOTB vtag from the cookie. */
5176 cookie = chunk->subh.cookie_hdr;
5177 packet->vtag = cookie->c.peer_vtag;
5178
5179 /* Set the skb to the belonging sock for accounting. */
5180 err_chunk->skb->sk = ep->base.sk;
5181 sctp_packet_append_chunk(packet, err_chunk);
5182 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
5183 SCTP_PACKET(packet));
5184 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
5185 } else
5186 sctp_chunk_free (err_chunk);
5187 }
5188}
5189
5190
5191/* Process a data chunk */
5192static int sctp_eat_data(const struct sctp_association *asoc,
5193 struct sctp_chunk *chunk,
5194 sctp_cmd_seq_t *commands)
5195{
5196 sctp_datahdr_t *data_hdr;
5197 struct sctp_chunk *err;
5198 size_t datalen;
5199 sctp_verb_t deliver;
5200 int tmp;
5201 __u32 tsn;
Neil Horman049b3ff2005-11-11 16:08:24 -08005202 int account_value;
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005203 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
Neil Horman049b3ff2005-11-11 16:08:24 -08005204 struct sock *sk = asoc->base.sk;
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005205 int rcvbuf_over = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005206
5207 data_hdr = chunk->subh.data_hdr = (sctp_datahdr_t *)chunk->skb->data;
5208 skb_pull(chunk->skb, sizeof(sctp_datahdr_t));
5209
5210 tsn = ntohl(data_hdr->tsn);
5211 SCTP_DEBUG_PRINTK("eat_data: TSN 0x%x.\n", tsn);
5212
5213 /* ASSERT: Now skb->data is really the user data. */
5214
Neil Horman049b3ff2005-11-11 16:08:24 -08005215 /*
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005216 * If we are established, and we have used up our receive buffer
5217 * memory, think about droping the frame.
5218 * Note that we have an opportunity to improve performance here.
5219 * If we accept one chunk from an skbuff, we have to keep all the
5220 * memory of that skbuff around until the chunk is read into user
5221 * space. Therefore, once we accept 1 chunk we may as well accept all
5222 * remaining chunks in the skbuff. The data_accepted flag helps us do
5223 * that.
Neil Horman049b3ff2005-11-11 16:08:24 -08005224 */
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005225 if ((asoc->state == SCTP_STATE_ESTABLISHED) && (!chunk->data_accepted)) {
Neil Horman049b3ff2005-11-11 16:08:24 -08005226 /*
5227 * If the receive buffer policy is 1, then each
5228 * association can allocate up to sk_rcvbuf bytes
5229 * otherwise, all the associations in aggregate
5230 * may allocate up to sk_rcvbuf bytes
5231 */
5232 if (asoc->ep->rcvbuf_policy)
5233 account_value = atomic_read(&asoc->rmem_alloc);
5234 else
5235 account_value = atomic_read(&sk->sk_rmem_alloc);
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005236 if (account_value > sk->sk_rcvbuf) {
5237 /*
5238 * We need to make forward progress, even when we are
5239 * under memory pressure, so we always allow the
5240 * next tsn after the ctsn ack point to be accepted.
5241 * This lets us avoid deadlocks in which we have to
5242 * drop frames that would otherwise let us drain the
5243 * receive queue.
5244 */
5245 if ((sctp_tsnmap_get_ctsn(map) + 1) != tsn)
5246 return SCTP_IERROR_IGNORE_TSN;
Neil Horman049b3ff2005-11-11 16:08:24 -08005247
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005248 /*
5249 * We're going to accept the frame but we should renege
5250 * to make space for it. This will send us down that
5251 * path later in this function.
5252 */
5253 rcvbuf_over = 1;
5254 }
Neil Horman049b3ff2005-11-11 16:08:24 -08005255 }
5256
Linus Torvalds1da177e2005-04-16 15:20:36 -07005257 /* Process ECN based congestion.
5258 *
5259 * Since the chunk structure is reused for all chunks within
5260 * a packet, we use ecn_ce_done to track if we've already
5261 * done CE processing for this packet.
5262 *
5263 * We need to do ECN processing even if we plan to discard the
5264 * chunk later.
5265 */
5266
5267 if (!chunk->ecn_ce_done) {
5268 struct sctp_af *af;
5269 chunk->ecn_ce_done = 1;
5270
5271 af = sctp_get_af_specific(
5272 ipver2af(chunk->skb->nh.iph->version));
5273
5274 if (af && af->is_ce(chunk->skb) && asoc->peer.ecn_capable) {
5275 /* Do real work as sideffect. */
5276 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_CE,
5277 SCTP_U32(tsn));
5278 }
5279 }
5280
5281 tmp = sctp_tsnmap_check(&asoc->peer.tsn_map, tsn);
5282 if (tmp < 0) {
5283 /* The TSN is too high--silently discard the chunk and
5284 * count on it getting retransmitted later.
5285 */
5286 return SCTP_IERROR_HIGH_TSN;
5287 } else if (tmp > 0) {
5288 /* This is a duplicate. Record it. */
5289 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_DUP, SCTP_U32(tsn));
5290 return SCTP_IERROR_DUP_TSN;
5291 }
5292
5293 /* This is a new TSN. */
5294
5295 /* Discard if there is no room in the receive window.
5296 * Actually, allow a little bit of overflow (up to a MTU).
5297 */
5298 datalen = ntohs(chunk->chunk_hdr->length);
5299 datalen -= sizeof(sctp_data_chunk_t);
5300
5301 deliver = SCTP_CMD_CHUNK_ULP;
5302
5303 /* Think about partial delivery. */
5304 if ((datalen >= asoc->rwnd) && (!asoc->ulpq.pd_mode)) {
5305
5306 /* Even if we don't accept this chunk there is
5307 * memory pressure.
5308 */
5309 sctp_add_cmd_sf(commands, SCTP_CMD_PART_DELIVER, SCTP_NULL());
5310 }
5311
5312 /* Spill over rwnd a little bit. Note: While allowed, this spill over
5313 * seems a bit troublesome in that frag_point varies based on
5314 * PMTU. In cases, such as loopback, this might be a rather
5315 * large spill over.
Neil Hormand5b9f4c2006-06-17 22:59:03 -07005316 * NOTE: If we have a full receive buffer here, we only renege if
5317 * our receiver can still make progress without the tsn being
5318 * received. We do this because in the event that the associations
5319 * receive queue is empty we are filling a leading gap, and since
5320 * reneging moves the gap to the end of the tsn stream, we are likely
5321 * to stall again very shortly. Avoiding the renege when we fill a
5322 * leading gap is a good heuristic for avoiding such steady state
5323 * stalls.
Linus Torvalds1da177e2005-04-16 15:20:36 -07005324 */
5325 if (!asoc->rwnd || asoc->rwnd_over ||
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005326 (datalen > asoc->rwnd + asoc->frag_point) ||
Neil Hormand5b9f4c2006-06-17 22:59:03 -07005327 (rcvbuf_over && (!skb_queue_len(&sk->sk_receive_queue)))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07005328
5329 /* If this is the next TSN, consider reneging to make
5330 * room. Note: Playing nice with a confused sender. A
5331 * malicious sender can still eat up all our buffer
5332 * space and in the future we may want to detect and
5333 * do more drastic reneging.
5334 */
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005335 if (sctp_tsnmap_has_gap(map) &&
5336 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07005337 SCTP_DEBUG_PRINTK("Reneging for tsn:%u\n", tsn);
5338 deliver = SCTP_CMD_RENEGE;
5339 } else {
5340 SCTP_DEBUG_PRINTK("Discard tsn: %u len: %Zd, "
5341 "rwnd: %d\n", tsn, datalen,
5342 asoc->rwnd);
5343 return SCTP_IERROR_IGNORE_TSN;
5344 }
5345 }
5346
5347 /*
5348 * Section 3.3.10.9 No User Data (9)
5349 *
5350 * Cause of error
5351 * ---------------
5352 * No User Data: This error cause is returned to the originator of a
5353 * DATA chunk if a received DATA chunk has no user data.
5354 */
5355 if (unlikely(0 == datalen)) {
5356 err = sctp_make_abort_no_data(asoc, chunk, tsn);
5357 if (err) {
5358 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
5359 SCTP_CHUNK(err));
5360 }
5361 /* We are going to ABORT, so we might as well stop
5362 * processing the rest of the chunks in the packet.
5363 */
5364 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07005365 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5366 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005367 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
Al Viro5be291f2006-11-20 17:01:06 -08005368 SCTP_PERR(SCTP_ERROR_NO_DATA));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005369 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
5370 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
5371 return SCTP_IERROR_NO_DATA;
5372 }
5373
5374 /* If definately accepting the DATA chunk, record its TSN, otherwise
5375 * wait for renege processing.
5376 */
5377 if (SCTP_CMD_CHUNK_ULP == deliver)
5378 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_TSN, SCTP_U32(tsn));
5379
Sridhar Samudrala9faa7302006-07-21 14:49:07 -07005380 chunk->data_accepted = 1;
5381
Linus Torvalds1da177e2005-04-16 15:20:36 -07005382 /* Note: Some chunks may get overcounted (if we drop) or overcounted
5383 * if we renege and the chunk arrives again.
5384 */
5385 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
5386 SCTP_INC_STATS(SCTP_MIB_INUNORDERCHUNKS);
5387 else
5388 SCTP_INC_STATS(SCTP_MIB_INORDERCHUNKS);
5389
5390 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
5391 *
5392 * If an endpoint receive a DATA chunk with an invalid stream
5393 * identifier, it shall acknowledge the reception of the DATA chunk
5394 * following the normal procedure, immediately send an ERROR chunk
5395 * with cause set to "Invalid Stream Identifier" (See Section 3.3.10)
5396 * and discard the DATA chunk.
5397 */
5398 if (ntohs(data_hdr->stream) >= asoc->c.sinit_max_instreams) {
5399 err = sctp_make_op_error(asoc, chunk, SCTP_ERROR_INV_STRM,
5400 &data_hdr->stream,
5401 sizeof(data_hdr->stream));
5402 if (err)
5403 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
5404 SCTP_CHUNK(err));
5405 return SCTP_IERROR_BAD_STREAM;
5406 }
5407
5408 /* Send the data up to the user. Note: Schedule the
5409 * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK
5410 * chunk needs the updated rwnd.
5411 */
5412 sctp_add_cmd_sf(commands, deliver, SCTP_CHUNK(chunk));
5413
5414 return SCTP_IERROR_NO_ERROR;
5415}