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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* SCTP kernel reference Implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999-2000 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 * Copyright (c) 2001-2002 Intel Corp.
6 * Copyright (c) 2002 Nokia Corp.
7 *
8 * This file is part of the SCTP kernel reference Implementation
9 *
10 * This is part of the SCTP Linux Kernel Reference Implementation.
11 *
12 * These are the state functions for the state machine.
13 *
14 * The SCTP reference implementation is free software;
15 * you can redistribute it and/or modify it under the terms of
16 * the GNU General Public License as published by
17 * the Free Software Foundation; either version 2, or (at your option)
18 * any later version.
19 *
20 * The SCTP reference implementation is distributed in the hope that it
21 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
22 * ************************
23 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
24 * See the GNU General Public License for more details.
25 *
26 * You should have received a copy of the GNU General Public License
27 * along with GNU CC; see the file COPYING. If not, write to
28 * the Free Software Foundation, 59 Temple Place - Suite 330,
29 * Boston, MA 02111-1307, USA.
30 *
31 * Please send any bug reports or fixes you make to the
32 * email address(es):
33 * lksctp developers <lksctp-developers@lists.sourceforge.net>
34 *
35 * Or submit a bug report through the following website:
36 * http://www.sf.net/projects/lksctp
37 *
38 * Written or modified by:
39 * La Monte H.P. Yarroll <piggy@acm.org>
40 * Karl Knutson <karl@athena.chicago.il.us>
41 * Mathew Kotowsky <kotowsky@sctp.org>
42 * Sridhar Samudrala <samudrala@us.ibm.com>
43 * Jon Grimm <jgrimm@us.ibm.com>
44 * Hui Huang <hui.huang@nokia.com>
45 * Dajiang Zhang <dajiang.zhang@nokia.com>
46 * Daisy Chang <daisyc@us.ibm.com>
47 * Ardelle Fan <ardelle.fan@intel.com>
48 * Ryan Layer <rmlayer@us.ibm.com>
49 * Kevin Gao <kevin.gao@intel.com>
50 *
51 * Any bugs reported given to us we will try to fix... any fixes shared will
52 * be incorporated into the next SCTP release.
53 */
54
55#include <linux/types.h>
56#include <linux/kernel.h>
57#include <linux/ip.h>
58#include <linux/ipv6.h>
59#include <linux/net.h>
60#include <linux/inet.h>
61#include <net/sock.h>
62#include <net/inet_ecn.h>
63#include <linux/skbuff.h>
64#include <net/sctp/sctp.h>
65#include <net/sctp/sm.h>
66#include <net/sctp/structs.h>
67
68static struct sctp_packet *sctp_abort_pkt_new(const struct sctp_endpoint *ep,
69 const struct sctp_association *asoc,
70 struct sctp_chunk *chunk,
71 const void *payload,
72 size_t paylen);
73static int sctp_eat_data(const struct sctp_association *asoc,
74 struct sctp_chunk *chunk,
75 sctp_cmd_seq_t *commands);
76static struct sctp_packet *sctp_ootb_pkt_new(const struct sctp_association *asoc,
77 const struct sctp_chunk *chunk);
78static void sctp_send_stale_cookie_err(const struct sctp_endpoint *ep,
79 const struct sctp_association *asoc,
80 const struct sctp_chunk *chunk,
81 sctp_cmd_seq_t *commands,
82 struct sctp_chunk *err_chunk);
83static sctp_disposition_t sctp_sf_do_5_2_6_stale(const struct sctp_endpoint *ep,
84 const struct sctp_association *asoc,
85 const sctp_subtype_t type,
86 void *arg,
87 sctp_cmd_seq_t *commands);
88static sctp_disposition_t sctp_sf_shut_8_4_5(const struct sctp_endpoint *ep,
89 const struct sctp_association *asoc,
90 const sctp_subtype_t type,
91 void *arg,
92 sctp_cmd_seq_t *commands);
93static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk);
94
Adrian Bunk52c1da32005-06-23 22:05:33 -070095static sctp_disposition_t sctp_stop_t1_and_abort(sctp_cmd_seq_t *commands,
Sridhar Samudrala8de8c872006-05-19 10:58:12 -070096 __u16 error, int sk_err,
Adrian Bunk52c1da32005-06-23 22:05:33 -070097 const struct sctp_association *asoc,
98 struct sctp_transport *transport);
99
100static sctp_disposition_t sctp_sf_violation_chunklen(
101 const struct sctp_endpoint *ep,
102 const struct sctp_association *asoc,
103 const sctp_subtype_t type,
104 void *arg,
105 sctp_cmd_seq_t *commands);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106
107/* Small helper function that checks if the chunk length
108 * is of the appropriate length. The 'required_length' argument
109 * is set to be the size of a specific chunk we are testing.
110 * Return Values: 1 = Valid length
111 * 0 = Invalid length
112 *
113 */
114static inline int
115sctp_chunk_length_valid(struct sctp_chunk *chunk,
116 __u16 required_length)
117{
118 __u16 chunk_length = ntohs(chunk->chunk_hdr->length);
119
120 if (unlikely(chunk_length < required_length))
121 return 0;
122
123 return 1;
124}
125
126/**********************************************************
127 * These are the state functions for handling chunk events.
128 **********************************************************/
129
130/*
131 * Process the final SHUTDOWN COMPLETE.
132 *
133 * Section: 4 (C) (diagram), 9.2
134 * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify
135 * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be
136 * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint
137 * should stop the T2-shutdown timer and remove all knowledge of the
138 * association (and thus the association enters the CLOSED state).
139 *
Jerome Forissier047a2422005-04-28 11:58:43 -0700140 * Verification Tag: 8.5.1(C), sctpimpguide 2.41.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141 * C) Rules for packet carrying SHUTDOWN COMPLETE:
142 * ...
Jerome Forissier047a2422005-04-28 11:58:43 -0700143 * - The receiver of a SHUTDOWN COMPLETE shall accept the packet
144 * if the Verification Tag field of the packet matches its own tag and
145 * the T bit is not set
146 * OR
147 * it is set to its peer's tag and the T bit is set in the Chunk
148 * Flags.
149 * Otherwise, the receiver MUST silently discard the packet
150 * and take no further action. An endpoint MUST ignore the
151 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152 *
153 * Inputs
154 * (endpoint, asoc, chunk)
155 *
156 * Outputs
157 * (asoc, reply_msg, msg_up, timers, counters)
158 *
159 * The return value is the disposition of the chunk.
160 */
161sctp_disposition_t sctp_sf_do_4_C(const struct sctp_endpoint *ep,
162 const struct sctp_association *asoc,
163 const sctp_subtype_t type,
164 void *arg,
165 sctp_cmd_seq_t *commands)
166{
167 struct sctp_chunk *chunk = arg;
168 struct sctp_ulpevent *ev;
169
170 /* RFC 2960 6.10 Bundling
171 *
172 * An endpoint MUST NOT bundle INIT, INIT ACK or
173 * SHUTDOWN COMPLETE with any other chunks.
174 */
175 if (!chunk->singleton)
176 return SCTP_DISPOSITION_VIOLATION;
177
178 if (!sctp_vtag_verify_either(chunk, asoc))
179 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
180
181 /* RFC 2960 10.2 SCTP-to-ULP
182 *
183 * H) SHUTDOWN COMPLETE notification
184 *
185 * When SCTP completes the shutdown procedures (section 9.2) this
186 * notification is passed to the upper layer.
187 */
188 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
189 0, 0, 0, GFP_ATOMIC);
190 if (!ev)
191 goto nomem;
192
193 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
194
195 /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint
196 * will verify that it is in SHUTDOWN-ACK-SENT state, if it is
197 * not the chunk should be discarded. If the endpoint is in
198 * the SHUTDOWN-ACK-SENT state the endpoint should stop the
199 * T2-shutdown timer and remove all knowledge of the
200 * association (and thus the association enters the CLOSED
201 * state).
202 */
203 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
204 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
205
206 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
207 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
208
209 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
210 SCTP_STATE(SCTP_STATE_CLOSED));
211
212 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
213 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
214
215 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
216
217 return SCTP_DISPOSITION_DELETE_TCB;
218
219nomem:
220 return SCTP_DISPOSITION_NOMEM;
221}
222
223/*
224 * Respond to a normal INIT chunk.
225 * We are the side that is being asked for an association.
226 *
227 * Section: 5.1 Normal Establishment of an Association, B
228 * B) "Z" shall respond immediately with an INIT ACK chunk. The
229 * destination IP address of the INIT ACK MUST be set to the source
230 * IP address of the INIT to which this INIT ACK is responding. In
231 * the response, besides filling in other parameters, "Z" must set the
232 * Verification Tag field to Tag_A, and also provide its own
233 * Verification Tag (Tag_Z) in the Initiate Tag field.
234 *
235 * Verification Tag: Must be 0.
236 *
237 * Inputs
238 * (endpoint, asoc, chunk)
239 *
240 * Outputs
241 * (asoc, reply_msg, msg_up, timers, counters)
242 *
243 * The return value is the disposition of the chunk.
244 */
245sctp_disposition_t sctp_sf_do_5_1B_init(const struct sctp_endpoint *ep,
246 const struct sctp_association *asoc,
247 const sctp_subtype_t type,
248 void *arg,
249 sctp_cmd_seq_t *commands)
250{
251 struct sctp_chunk *chunk = arg;
252 struct sctp_chunk *repl;
253 struct sctp_association *new_asoc;
254 struct sctp_chunk *err_chunk;
255 struct sctp_packet *packet;
256 sctp_unrecognized_param_t *unk_param;
257 struct sock *sk;
258 int len;
259
260 /* 6.10 Bundling
261 * An endpoint MUST NOT bundle INIT, INIT ACK or
262 * SHUTDOWN COMPLETE with any other chunks.
263 *
264 * IG Section 2.11.2
265 * Furthermore, we require that the receiver of an INIT chunk MUST
266 * enforce these rules by silently discarding an arriving packet
267 * with an INIT chunk that is bundled with other chunks.
268 */
269 if (!chunk->singleton)
270 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
271
272 /* If the packet is an OOTB packet which is temporarily on the
273 * control endpoint, respond with an ABORT.
274 */
275 if (ep == sctp_sk((sctp_get_ctl_sock()))->ep)
276 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
277
278 sk = ep->base.sk;
279 /* If the endpoint is not listening or if the number of associations
280 * on the TCP-style socket exceed the max backlog, respond with an
281 * ABORT.
282 */
283 if (!sctp_sstate(sk, LISTENING) ||
284 (sctp_style(sk, TCP) &&
285 sk_acceptq_is_full(sk)))
286 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
287
288 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
289 * Tag.
290 */
291 if (chunk->sctp_hdr->vtag != 0)
292 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
293
294 /* Make sure that the INIT chunk has a valid length.
295 * Normally, this would cause an ABORT with a Protocol Violation
296 * error, but since we don't have an association, we'll
297 * just discard the packet.
298 */
299 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
300 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
301
302 /* Verify the INIT chunk before processing it. */
303 err_chunk = NULL;
304 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
305 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
306 &err_chunk)) {
307 /* This chunk contains fatal error. It is to be discarded.
308 * Send an ABORT, with causes if there is any.
309 */
310 if (err_chunk) {
311 packet = sctp_abort_pkt_new(ep, asoc, arg,
312 (__u8 *)(err_chunk->chunk_hdr) +
313 sizeof(sctp_chunkhdr_t),
314 ntohs(err_chunk->chunk_hdr->length) -
315 sizeof(sctp_chunkhdr_t));
316
317 sctp_chunk_free(err_chunk);
318
319 if (packet) {
320 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
321 SCTP_PACKET(packet));
322 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
323 return SCTP_DISPOSITION_CONSUME;
324 } else {
325 return SCTP_DISPOSITION_NOMEM;
326 }
327 } else {
328 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg,
329 commands);
330 }
331 }
332
333 /* Grab the INIT header. */
334 chunk->subh.init_hdr = (sctp_inithdr_t *)chunk->skb->data;
335
336 /* Tag the variable length parameters. */
337 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
338
339 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
340 if (!new_asoc)
341 goto nomem;
342
343 /* The call, sctp_process_init(), can fail on memory allocation. */
344 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
345 sctp_source(chunk),
346 (sctp_init_chunk_t *)chunk->chunk_hdr,
347 GFP_ATOMIC))
348 goto nomem_init;
349
350 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
351
352 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
353
354 /* If there are errors need to be reported for unknown parameters,
355 * make sure to reserve enough room in the INIT ACK for them.
356 */
357 len = 0;
358 if (err_chunk)
359 len = ntohs(err_chunk->chunk_hdr->length) -
360 sizeof(sctp_chunkhdr_t);
361
362 if (sctp_assoc_set_bind_addr_from_ep(new_asoc, GFP_ATOMIC) < 0)
363 goto nomem_ack;
364
365 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
366 if (!repl)
367 goto nomem_ack;
368
369 /* If there are errors need to be reported for unknown parameters,
370 * include them in the outgoing INIT ACK as "Unrecognized parameter"
371 * parameter.
372 */
373 if (err_chunk) {
374 /* Get the "Unrecognized parameter" parameter(s) out of the
375 * ERROR chunk generated by sctp_verify_init(). Since the
376 * error cause code for "unknown parameter" and the
377 * "Unrecognized parameter" type is the same, we can
378 * construct the parameters in INIT ACK by copying the
379 * ERROR causes over.
380 */
381 unk_param = (sctp_unrecognized_param_t *)
382 ((__u8 *)(err_chunk->chunk_hdr) +
383 sizeof(sctp_chunkhdr_t));
384 /* Replace the cause code with the "Unrecognized parameter"
385 * parameter type.
386 */
387 sctp_addto_chunk(repl, len, unk_param);
388 sctp_chunk_free(err_chunk);
389 }
390
391 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
392
393 /*
394 * Note: After sending out INIT ACK with the State Cookie parameter,
395 * "Z" MUST NOT allocate any resources, nor keep any states for the
396 * new association. Otherwise, "Z" will be vulnerable to resource
397 * attacks.
398 */
399 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
400
401 return SCTP_DISPOSITION_DELETE_TCB;
402
403nomem_ack:
404 if (err_chunk)
405 sctp_chunk_free(err_chunk);
406nomem_init:
407 sctp_association_free(new_asoc);
408nomem:
409 return SCTP_DISPOSITION_NOMEM;
410}
411
412/*
413 * Respond to a normal INIT ACK chunk.
414 * We are the side that is initiating the association.
415 *
416 * Section: 5.1 Normal Establishment of an Association, C
417 * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init
418 * timer and leave COOKIE-WAIT state. "A" shall then send the State
419 * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start
420 * the T1-cookie timer, and enter the COOKIE-ECHOED state.
421 *
422 * Note: The COOKIE ECHO chunk can be bundled with any pending outbound
423 * DATA chunks, but it MUST be the first chunk in the packet and
424 * until the COOKIE ACK is returned the sender MUST NOT send any
425 * other packets to the peer.
426 *
427 * Verification Tag: 3.3.3
428 * If the value of the Initiate Tag in a received INIT ACK chunk is
429 * found to be 0, the receiver MUST treat it as an error and close the
430 * association by transmitting an ABORT.
431 *
432 * Inputs
433 * (endpoint, asoc, chunk)
434 *
435 * Outputs
436 * (asoc, reply_msg, msg_up, timers, counters)
437 *
438 * The return value is the disposition of the chunk.
439 */
440sctp_disposition_t sctp_sf_do_5_1C_ack(const struct sctp_endpoint *ep,
441 const struct sctp_association *asoc,
442 const sctp_subtype_t type,
443 void *arg,
444 sctp_cmd_seq_t *commands)
445{
446 struct sctp_chunk *chunk = arg;
447 sctp_init_chunk_t *initchunk;
448 __u32 init_tag;
449 struct sctp_chunk *err_chunk;
450 struct sctp_packet *packet;
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700451 __u16 error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452
453 if (!sctp_vtag_verify(chunk, asoc))
454 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
455
456 /* Make sure that the INIT-ACK chunk has a valid length */
457 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_initack_chunk_t)))
458 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
459 commands);
460 /* 6.10 Bundling
461 * An endpoint MUST NOT bundle INIT, INIT ACK or
462 * SHUTDOWN COMPLETE with any other chunks.
463 */
464 if (!chunk->singleton)
465 return SCTP_DISPOSITION_VIOLATION;
466
467 /* Grab the INIT header. */
468 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
469
470 init_tag = ntohl(chunk->subh.init_hdr->init_tag);
471
472 /* Verification Tag: 3.3.3
473 * If the value of the Initiate Tag in a received INIT ACK
474 * chunk is found to be 0, the receiver MUST treat it as an
475 * error and close the association by transmitting an ABORT.
476 */
477 if (!init_tag) {
478 struct sctp_chunk *reply = sctp_make_abort(asoc, chunk, 0);
479 if (!reply)
480 goto nomem;
481
482 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700483 return sctp_stop_t1_and_abort(commands, SCTP_ERROR_INV_PARAM,
484 ECONNREFUSED, asoc,
485 chunk->transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700486 }
487
488 /* Verify the INIT chunk before processing it. */
489 err_chunk = NULL;
490 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
491 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
492 &err_chunk)) {
493
494 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
495
496 /* This chunk contains fatal error. It is to be discarded.
497 * Send an ABORT, with causes if there is any.
498 */
499 if (err_chunk) {
500 packet = sctp_abort_pkt_new(ep, asoc, arg,
501 (__u8 *)(err_chunk->chunk_hdr) +
502 sizeof(sctp_chunkhdr_t),
503 ntohs(err_chunk->chunk_hdr->length) -
504 sizeof(sctp_chunkhdr_t));
505
506 sctp_chunk_free(err_chunk);
507
508 if (packet) {
509 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
510 SCTP_PACKET(packet));
511 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700512 error = SCTP_ERROR_INV_PARAM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513 } else {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700514 error = SCTP_ERROR_NO_RESOURCE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700515 }
516 } else {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700517 sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
518 error = SCTP_ERROR_INV_PARAM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700519 }
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700520 return sctp_stop_t1_and_abort(commands, error, ECONNREFUSED,
521 asoc, chunk->transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522 }
523
524 /* Tag the variable length parameters. Note that we never
525 * convert the parameters in an INIT chunk.
526 */
527 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
528
529 initchunk = (sctp_init_chunk_t *) chunk->chunk_hdr;
530
531 sctp_add_cmd_sf(commands, SCTP_CMD_PEER_INIT,
532 SCTP_PEER_INIT(initchunk));
533
Frank Filz3f7a87d2005-06-20 13:14:57 -0700534 /* Reset init error count upon receipt of INIT-ACK. */
535 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
536
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537 /* 5.1 C) "A" shall stop the T1-init timer and leave
538 * COOKIE-WAIT state. "A" shall then ... start the T1-cookie
539 * timer, and enter the COOKIE-ECHOED state.
540 */
541 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
542 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
543 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
544 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
545 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
546 SCTP_STATE(SCTP_STATE_COOKIE_ECHOED));
547
548 /* 5.1 C) "A" shall then send the State Cookie received in the
549 * INIT ACK chunk in a COOKIE ECHO chunk, ...
550 */
551 /* If there is any errors to report, send the ERROR chunk generated
552 * for unknown parameters as well.
553 */
554 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_COOKIE_ECHO,
555 SCTP_CHUNK(err_chunk));
556
557 return SCTP_DISPOSITION_CONSUME;
558
559nomem:
560 return SCTP_DISPOSITION_NOMEM;
561}
562
563/*
564 * Respond to a normal COOKIE ECHO chunk.
565 * We are the side that is being asked for an association.
566 *
567 * Section: 5.1 Normal Establishment of an Association, D
568 * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply
569 * with a COOKIE ACK chunk after building a TCB and moving to
570 * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with
571 * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK
572 * chunk MUST be the first chunk in the packet.
573 *
574 * IMPLEMENTATION NOTE: An implementation may choose to send the
575 * Communication Up notification to the SCTP user upon reception
576 * of a valid COOKIE ECHO chunk.
577 *
578 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
579 * D) Rules for packet carrying a COOKIE ECHO
580 *
581 * - When sending a COOKIE ECHO, the endpoint MUST use the value of the
582 * Initial Tag received in the INIT ACK.
583 *
584 * - The receiver of a COOKIE ECHO follows the procedures in Section 5.
585 *
586 * Inputs
587 * (endpoint, asoc, chunk)
588 *
589 * Outputs
590 * (asoc, reply_msg, msg_up, timers, counters)
591 *
592 * The return value is the disposition of the chunk.
593 */
594sctp_disposition_t sctp_sf_do_5_1D_ce(const struct sctp_endpoint *ep,
595 const struct sctp_association *asoc,
596 const sctp_subtype_t type, void *arg,
597 sctp_cmd_seq_t *commands)
598{
599 struct sctp_chunk *chunk = arg;
600 struct sctp_association *new_asoc;
601 sctp_init_chunk_t *peer_init;
602 struct sctp_chunk *repl;
603 struct sctp_ulpevent *ev;
604 int error = 0;
605 struct sctp_chunk *err_chk_p;
606
607 /* If the packet is an OOTB packet which is temporarily on the
608 * control endpoint, respond with an ABORT.
609 */
610 if (ep == sctp_sk((sctp_get_ctl_sock()))->ep)
611 return sctp_sf_ootb(ep, asoc, type, arg, commands);
612
613 /* Make sure that the COOKIE_ECHO chunk has a valid length.
614 * In this case, we check that we have enough for at least a
615 * chunk header. More detailed verification is done
616 * in sctp_unpack_cookie().
617 */
618 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
619 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
620
621 /* "Decode" the chunk. We have no optional parameters so we
622 * are in good shape.
623 */
624 chunk->subh.cookie_hdr =
625 (struct sctp_signed_cookie *)chunk->skb->data;
Sridhar Samudrala62b08082006-05-05 17:04:43 -0700626 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
627 sizeof(sctp_chunkhdr_t)))
628 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629
630 /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
631 * "Z" will reply with a COOKIE ACK chunk after building a TCB
632 * and moving to the ESTABLISHED state.
633 */
634 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
635 &err_chk_p);
636
637 /* FIXME:
638 * If the re-build failed, what is the proper error path
639 * from here?
640 *
641 * [We should abort the association. --piggy]
642 */
643 if (!new_asoc) {
644 /* FIXME: Several errors are possible. A bad cookie should
645 * be silently discarded, but think about logging it too.
646 */
647 switch (error) {
648 case -SCTP_IERROR_NOMEM:
649 goto nomem;
650
651 case -SCTP_IERROR_STALE_COOKIE:
652 sctp_send_stale_cookie_err(ep, asoc, chunk, commands,
653 err_chk_p);
654 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
655
656 case -SCTP_IERROR_BAD_SIG:
657 default:
658 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
659 };
660 }
661
662 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
663 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
664 SCTP_STATE(SCTP_STATE_ESTABLISHED));
665 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
666 SCTP_INC_STATS(SCTP_MIB_PASSIVEESTABS);
667 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
668
669 if (new_asoc->autoclose)
670 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
671 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
672
673 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
674
675 /* Re-build the bind address for the association is done in
676 * the sctp_unpack_cookie() already.
677 */
678 /* This is a brand-new association, so these are not yet side
679 * effects--it is safe to run them here.
680 */
681 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
682
683 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
684 &chunk->subh.cookie_hdr->c.peer_addr,
685 peer_init, GFP_ATOMIC))
686 goto nomem_init;
687
688 repl = sctp_make_cookie_ack(new_asoc, chunk);
689 if (!repl)
690 goto nomem_repl;
691
692 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
693
694 /* RFC 2960 5.1 Normal Establishment of an Association
695 *
696 * D) IMPLEMENTATION NOTE: An implementation may choose to
697 * send the Communication Up notification to the SCTP user
698 * upon reception of a valid COOKIE ECHO chunk.
699 */
700 ev = sctp_ulpevent_make_assoc_change(new_asoc, 0, SCTP_COMM_UP, 0,
701 new_asoc->c.sinit_num_ostreams,
702 new_asoc->c.sinit_max_instreams,
703 GFP_ATOMIC);
704 if (!ev)
705 goto nomem_ev;
706
707 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
708
709 /* Sockets API Draft Section 5.3.1.6
710 * When a peer sends a Adaption Layer Indication parameter , SCTP
711 * delivers this notification to inform the application that of the
712 * peers requested adaption layer.
713 */
714 if (new_asoc->peer.adaption_ind) {
715 ev = sctp_ulpevent_make_adaption_indication(new_asoc,
716 GFP_ATOMIC);
717 if (!ev)
718 goto nomem_ev;
719
720 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
721 SCTP_ULPEVENT(ev));
722 }
723
724 return SCTP_DISPOSITION_CONSUME;
725
726nomem_ev:
727 sctp_chunk_free(repl);
728nomem_repl:
729nomem_init:
730 sctp_association_free(new_asoc);
731nomem:
732 return SCTP_DISPOSITION_NOMEM;
733}
734
735/*
736 * Respond to a normal COOKIE ACK chunk.
737 * We are the side that is being asked for an association.
738 *
739 * RFC 2960 5.1 Normal Establishment of an Association
740 *
741 * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the
742 * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie
743 * timer. It may also notify its ULP about the successful
744 * establishment of the association with a Communication Up
745 * notification (see Section 10).
746 *
747 * Verification Tag:
748 * Inputs
749 * (endpoint, asoc, chunk)
750 *
751 * Outputs
752 * (asoc, reply_msg, msg_up, timers, counters)
753 *
754 * The return value is the disposition of the chunk.
755 */
756sctp_disposition_t sctp_sf_do_5_1E_ca(const struct sctp_endpoint *ep,
757 const struct sctp_association *asoc,
758 const sctp_subtype_t type, void *arg,
759 sctp_cmd_seq_t *commands)
760{
761 struct sctp_chunk *chunk = arg;
762 struct sctp_ulpevent *ev;
763
764 if (!sctp_vtag_verify(chunk, asoc))
765 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
766
767 /* Verify that the chunk length for the COOKIE-ACK is OK.
768 * If we don't do this, any bundled chunks may be junked.
769 */
770 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
771 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
772 commands);
773
774 /* Reset init error count upon receipt of COOKIE-ACK,
775 * to avoid problems with the managemement of this
776 * counter in stale cookie situations when a transition back
777 * from the COOKIE-ECHOED state to the COOKIE-WAIT
778 * state is performed.
779 */
Frank Filz3f7a87d2005-06-20 13:14:57 -0700780 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
Linus Torvalds1da177e2005-04-16 15:20:36 -0700781
782 /* RFC 2960 5.1 Normal Establishment of an Association
783 *
784 * E) Upon reception of the COOKIE ACK, endpoint "A" will move
785 * from the COOKIE-ECHOED state to the ESTABLISHED state,
786 * stopping the T1-cookie timer.
787 */
788 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
789 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
790 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
791 SCTP_STATE(SCTP_STATE_ESTABLISHED));
792 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
793 SCTP_INC_STATS(SCTP_MIB_ACTIVEESTABS);
794 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
795 if (asoc->autoclose)
796 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
797 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
798 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
799
800 /* It may also notify its ULP about the successful
801 * establishment of the association with a Communication Up
802 * notification (see Section 10).
803 */
804 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP,
805 0, asoc->c.sinit_num_ostreams,
806 asoc->c.sinit_max_instreams,
807 GFP_ATOMIC);
808
809 if (!ev)
810 goto nomem;
811
812 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
813
814 /* Sockets API Draft Section 5.3.1.6
815 * When a peer sends a Adaption Layer Indication parameter , SCTP
816 * delivers this notification to inform the application that of the
817 * peers requested adaption layer.
818 */
819 if (asoc->peer.adaption_ind) {
820 ev = sctp_ulpevent_make_adaption_indication(asoc, GFP_ATOMIC);
821 if (!ev)
822 goto nomem;
823
824 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
825 SCTP_ULPEVENT(ev));
826 }
827
828 return SCTP_DISPOSITION_CONSUME;
829nomem:
830 return SCTP_DISPOSITION_NOMEM;
831}
832
833/* Generate and sendout a heartbeat packet. */
834static sctp_disposition_t sctp_sf_heartbeat(const struct sctp_endpoint *ep,
835 const struct sctp_association *asoc,
836 const sctp_subtype_t type,
837 void *arg,
838 sctp_cmd_seq_t *commands)
839{
840 struct sctp_transport *transport = (struct sctp_transport *) arg;
841 struct sctp_chunk *reply;
842 sctp_sender_hb_info_t hbinfo;
843 size_t paylen = 0;
844
845 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO;
846 hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t));
847 hbinfo.daddr = transport->ipaddr;
848 hbinfo.sent_at = jiffies;
849
850 /* Send a heartbeat to our peer. */
851 paylen = sizeof(sctp_sender_hb_info_t);
852 reply = sctp_make_heartbeat(asoc, transport, &hbinfo, paylen);
853 if (!reply)
854 return SCTP_DISPOSITION_NOMEM;
855
856 /* Set rto_pending indicating that an RTT measurement
857 * is started with this heartbeat chunk.
858 */
859 sctp_add_cmd_sf(commands, SCTP_CMD_RTO_PENDING,
860 SCTP_TRANSPORT(transport));
861
862 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
863 return SCTP_DISPOSITION_CONSUME;
864}
865
866/* Generate a HEARTBEAT packet on the given transport. */
867sctp_disposition_t sctp_sf_sendbeat_8_3(const struct sctp_endpoint *ep,
868 const struct sctp_association *asoc,
869 const sctp_subtype_t type,
870 void *arg,
871 sctp_cmd_seq_t *commands)
872{
873 struct sctp_transport *transport = (struct sctp_transport *) arg;
874
Vlad Yaseviche2c2fc22006-01-30 16:00:40 -0800875 if (asoc->overall_error_count >= asoc->max_retrans) {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -0700876 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
877 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700878 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
879 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
880 SCTP_U32(SCTP_ERROR_NO_ERROR));
881 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
882 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
883 return SCTP_DISPOSITION_DELETE_TCB;
884 }
885
886 /* Section 3.3.5.
887 * The Sender-specific Heartbeat Info field should normally include
888 * information about the sender's current time when this HEARTBEAT
889 * chunk is sent and the destination transport address to which this
890 * HEARTBEAT is sent (see Section 8.3).
891 */
892
Frank Filz52ccb8e2005-12-22 11:36:46 -0800893 if (transport->param_flags & SPP_HB_ENABLE) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700894 if (SCTP_DISPOSITION_NOMEM ==
895 sctp_sf_heartbeat(ep, asoc, type, arg,
896 commands))
897 return SCTP_DISPOSITION_NOMEM;
898 /* Set transport error counter and association error counter
899 * when sending heartbeat.
900 */
901 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_RESET,
902 SCTP_TRANSPORT(transport));
903 }
904 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMER_UPDATE,
905 SCTP_TRANSPORT(transport));
906
907 return SCTP_DISPOSITION_CONSUME;
908}
909
910/*
911 * Process an heartbeat request.
912 *
913 * Section: 8.3 Path Heartbeat
914 * The receiver of the HEARTBEAT should immediately respond with a
915 * HEARTBEAT ACK that contains the Heartbeat Information field copied
916 * from the received HEARTBEAT chunk.
917 *
918 * Verification Tag: 8.5 Verification Tag [Normal verification]
919 * When receiving an SCTP packet, the endpoint MUST ensure that the
920 * value in the Verification Tag field of the received SCTP packet
921 * matches its own Tag. If the received Verification Tag value does not
922 * match the receiver's own tag value, the receiver shall silently
923 * discard the packet and shall not process it any further except for
924 * those cases listed in Section 8.5.1 below.
925 *
926 * Inputs
927 * (endpoint, asoc, chunk)
928 *
929 * Outputs
930 * (asoc, reply_msg, msg_up, timers, counters)
931 *
932 * The return value is the disposition of the chunk.
933 */
934sctp_disposition_t sctp_sf_beat_8_3(const struct sctp_endpoint *ep,
935 const struct sctp_association *asoc,
936 const sctp_subtype_t type,
937 void *arg,
938 sctp_cmd_seq_t *commands)
939{
940 struct sctp_chunk *chunk = arg;
941 struct sctp_chunk *reply;
942 size_t paylen = 0;
943
944 if (!sctp_vtag_verify(chunk, asoc))
945 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
946
947 /* Make sure that the HEARTBEAT chunk has a valid length. */
948 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t)))
949 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
950 commands);
951
952 /* 8.3 The receiver of the HEARTBEAT should immediately
953 * respond with a HEARTBEAT ACK that contains the Heartbeat
954 * Information field copied from the received HEARTBEAT chunk.
955 */
956 chunk->subh.hb_hdr = (sctp_heartbeathdr_t *) chunk->skb->data;
957 paylen = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
Sridhar Samudrala62b08082006-05-05 17:04:43 -0700958 if (!pskb_pull(chunk->skb, paylen))
959 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700960
961 reply = sctp_make_heartbeat_ack(asoc, chunk,
962 chunk->subh.hb_hdr, paylen);
963 if (!reply)
964 goto nomem;
965
966 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
967 return SCTP_DISPOSITION_CONSUME;
968
969nomem:
970 return SCTP_DISPOSITION_NOMEM;
971}
972
973/*
974 * Process the returning HEARTBEAT ACK.
975 *
976 * Section: 8.3 Path Heartbeat
977 * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT
978 * should clear the error counter of the destination transport
979 * address to which the HEARTBEAT was sent, and mark the destination
980 * transport address as active if it is not so marked. The endpoint may
981 * optionally report to the upper layer when an inactive destination
982 * address is marked as active due to the reception of the latest
983 * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also
984 * clear the association overall error count as well (as defined
985 * in section 8.1).
986 *
987 * The receiver of the HEARTBEAT ACK should also perform an RTT
988 * measurement for that destination transport address using the time
989 * value carried in the HEARTBEAT ACK chunk.
990 *
991 * Verification Tag: 8.5 Verification Tag [Normal verification]
992 *
993 * Inputs
994 * (endpoint, asoc, chunk)
995 *
996 * Outputs
997 * (asoc, reply_msg, msg_up, timers, counters)
998 *
999 * The return value is the disposition of the chunk.
1000 */
1001sctp_disposition_t sctp_sf_backbeat_8_3(const struct sctp_endpoint *ep,
1002 const struct sctp_association *asoc,
1003 const sctp_subtype_t type,
1004 void *arg,
1005 sctp_cmd_seq_t *commands)
1006{
1007 struct sctp_chunk *chunk = arg;
1008 union sctp_addr from_addr;
1009 struct sctp_transport *link;
1010 sctp_sender_hb_info_t *hbinfo;
1011 unsigned long max_interval;
1012
1013 if (!sctp_vtag_verify(chunk, asoc))
1014 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1015
1016 /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */
1017 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t)))
1018 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1019 commands);
1020
1021 hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
Vladislav Yasevicha6012662006-05-19 14:25:53 -07001022 /* Make sure that the length of the parameter is what we expect */
1023 if (ntohs(hbinfo->param_hdr.length) !=
1024 sizeof(sctp_sender_hb_info_t)) {
1025 return SCTP_DISPOSITION_DISCARD;
1026 }
1027
Linus Torvalds1da177e2005-04-16 15:20:36 -07001028 from_addr = hbinfo->daddr;
1029 link = sctp_assoc_lookup_paddr(asoc, &from_addr);
1030
1031 /* This should never happen, but lets log it if so. */
Frank Filz3f7a87d2005-06-20 13:14:57 -07001032 if (unlikely(!link)) {
1033 if (from_addr.sa.sa_family == AF_INET6) {
1034 printk(KERN_WARNING
1035 "%s association %p could not find address "
Joe Perches46b86a22006-01-13 14:29:07 -08001036 NIP6_FMT "\n",
Frank Filz3f7a87d2005-06-20 13:14:57 -07001037 __FUNCTION__,
1038 asoc,
1039 NIP6(from_addr.v6.sin6_addr));
1040 } else {
1041 printk(KERN_WARNING
1042 "%s association %p could not find address "
Joe Perches46b86a22006-01-13 14:29:07 -08001043 NIPQUAD_FMT "\n",
Frank Filz3f7a87d2005-06-20 13:14:57 -07001044 __FUNCTION__,
1045 asoc,
1046 NIPQUAD(from_addr.v4.sin_addr.s_addr));
1047 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001048 return SCTP_DISPOSITION_DISCARD;
1049 }
1050
Frank Filz52ccb8e2005-12-22 11:36:46 -08001051 max_interval = link->hbinterval + link->rto;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001052
1053 /* Check if the timestamp looks valid. */
1054 if (time_after(hbinfo->sent_at, jiffies) ||
1055 time_after(jiffies, hbinfo->sent_at + max_interval)) {
1056 SCTP_DEBUG_PRINTK("%s: HEARTBEAT ACK with invalid timestamp"
1057 "received for transport: %p\n",
1058 __FUNCTION__, link);
1059 return SCTP_DISPOSITION_DISCARD;
1060 }
1061
1062 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of
1063 * the HEARTBEAT should clear the error counter of the
1064 * destination transport address to which the HEARTBEAT was
1065 * sent and mark the destination transport address as active if
1066 * it is not so marked.
1067 */
1068 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_ON, SCTP_TRANSPORT(link));
1069
1070 return SCTP_DISPOSITION_CONSUME;
1071}
1072
1073/* Helper function to send out an abort for the restart
1074 * condition.
1075 */
1076static int sctp_sf_send_restart_abort(union sctp_addr *ssa,
1077 struct sctp_chunk *init,
1078 sctp_cmd_seq_t *commands)
1079{
1080 int len;
1081 struct sctp_packet *pkt;
1082 union sctp_addr_param *addrparm;
1083 struct sctp_errhdr *errhdr;
1084 struct sctp_endpoint *ep;
1085 char buffer[sizeof(struct sctp_errhdr)+sizeof(union sctp_addr_param)];
1086 struct sctp_af *af = sctp_get_af_specific(ssa->v4.sin_family);
1087
1088 /* Build the error on the stack. We are way to malloc crazy
1089 * throughout the code today.
1090 */
1091 errhdr = (struct sctp_errhdr *)buffer;
1092 addrparm = (union sctp_addr_param *)errhdr->variable;
1093
1094 /* Copy into a parm format. */
1095 len = af->to_addr_param(ssa, addrparm);
1096 len += sizeof(sctp_errhdr_t);
1097
1098 errhdr->cause = SCTP_ERROR_RESTART;
1099 errhdr->length = htons(len);
1100
1101 /* Assign to the control socket. */
1102 ep = sctp_sk((sctp_get_ctl_sock()))->ep;
1103
1104 /* Association is NULL since this may be a restart attack and we
1105 * want to send back the attacker's vtag.
1106 */
1107 pkt = sctp_abort_pkt_new(ep, NULL, init, errhdr, len);
1108
1109 if (!pkt)
1110 goto out;
1111 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, SCTP_PACKET(pkt));
1112
1113 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
1114
1115 /* Discard the rest of the inbound packet. */
1116 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
1117
1118out:
1119 /* Even if there is no memory, treat as a failure so
1120 * the packet will get dropped.
1121 */
1122 return 0;
1123}
1124
1125/* A restart is occurring, check to make sure no new addresses
1126 * are being added as we may be under a takeover attack.
1127 */
1128static int sctp_sf_check_restart_addrs(const struct sctp_association *new_asoc,
1129 const struct sctp_association *asoc,
1130 struct sctp_chunk *init,
1131 sctp_cmd_seq_t *commands)
1132{
1133 struct sctp_transport *new_addr, *addr;
1134 struct list_head *pos, *pos2;
1135 int found;
1136
1137 /* Implementor's Guide - Sectin 5.2.2
1138 * ...
1139 * Before responding the endpoint MUST check to see if the
1140 * unexpected INIT adds new addresses to the association. If new
1141 * addresses are added to the association, the endpoint MUST respond
1142 * with an ABORT..
1143 */
1144
1145 /* Search through all current addresses and make sure
1146 * we aren't adding any new ones.
1147 */
1148 new_addr = NULL;
1149 found = 0;
1150
1151 list_for_each(pos, &new_asoc->peer.transport_addr_list) {
1152 new_addr = list_entry(pos, struct sctp_transport, transports);
1153 found = 0;
1154 list_for_each(pos2, &asoc->peer.transport_addr_list) {
1155 addr = list_entry(pos2, struct sctp_transport,
1156 transports);
1157 if (sctp_cmp_addr_exact(&new_addr->ipaddr,
1158 &addr->ipaddr)) {
1159 found = 1;
1160 break;
1161 }
1162 }
1163 if (!found)
1164 break;
1165 }
1166
1167 /* If a new address was added, ABORT the sender. */
1168 if (!found && new_addr) {
1169 sctp_sf_send_restart_abort(&new_addr->ipaddr, init, commands);
1170 }
1171
1172 /* Return success if all addresses were found. */
1173 return found;
1174}
1175
1176/* Populate the verification/tie tags based on overlapping INIT
1177 * scenario.
1178 *
1179 * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state.
1180 */
1181static void sctp_tietags_populate(struct sctp_association *new_asoc,
1182 const struct sctp_association *asoc)
1183{
1184 switch (asoc->state) {
1185
1186 /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */
1187
1188 case SCTP_STATE_COOKIE_WAIT:
1189 new_asoc->c.my_vtag = asoc->c.my_vtag;
1190 new_asoc->c.my_ttag = asoc->c.my_vtag;
1191 new_asoc->c.peer_ttag = 0;
1192 break;
1193
1194 case SCTP_STATE_COOKIE_ECHOED:
1195 new_asoc->c.my_vtag = asoc->c.my_vtag;
1196 new_asoc->c.my_ttag = asoc->c.my_vtag;
1197 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1198 break;
1199
1200 /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED,
1201 * COOKIE-WAIT and SHUTDOWN-ACK-SENT
1202 */
1203 default:
1204 new_asoc->c.my_ttag = asoc->c.my_vtag;
1205 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1206 break;
1207 };
1208
1209 /* Other parameters for the endpoint SHOULD be copied from the
1210 * existing parameters of the association (e.g. number of
1211 * outbound streams) into the INIT ACK and cookie.
1212 */
1213 new_asoc->rwnd = asoc->rwnd;
1214 new_asoc->c.sinit_num_ostreams = asoc->c.sinit_num_ostreams;
1215 new_asoc->c.sinit_max_instreams = asoc->c.sinit_max_instreams;
1216 new_asoc->c.initial_tsn = asoc->c.initial_tsn;
1217}
1218
1219/*
1220 * Compare vtag/tietag values to determine unexpected COOKIE-ECHO
1221 * handling action.
1222 *
1223 * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists.
1224 *
1225 * Returns value representing action to be taken. These action values
1226 * correspond to Action/Description values in RFC 2960, Table 2.
1227 */
1228static char sctp_tietags_compare(struct sctp_association *new_asoc,
1229 const struct sctp_association *asoc)
1230{
1231 /* In this case, the peer may have restarted. */
1232 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1233 (asoc->c.peer_vtag != new_asoc->c.peer_vtag) &&
1234 (asoc->c.my_vtag == new_asoc->c.my_ttag) &&
1235 (asoc->c.peer_vtag == new_asoc->c.peer_ttag))
1236 return 'A';
1237
1238 /* Collision case B. */
1239 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1240 ((asoc->c.peer_vtag != new_asoc->c.peer_vtag) ||
1241 (0 == asoc->c.peer_vtag))) {
1242 return 'B';
1243 }
1244
1245 /* Collision case D. */
1246 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1247 (asoc->c.peer_vtag == new_asoc->c.peer_vtag))
1248 return 'D';
1249
1250 /* Collision case C. */
1251 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1252 (asoc->c.peer_vtag == new_asoc->c.peer_vtag) &&
1253 (0 == new_asoc->c.my_ttag) &&
1254 (0 == new_asoc->c.peer_ttag))
1255 return 'C';
1256
1257 /* No match to any of the special cases; discard this packet. */
1258 return 'E';
1259}
1260
1261/* Common helper routine for both duplicate and simulataneous INIT
1262 * chunk handling.
1263 */
1264static sctp_disposition_t sctp_sf_do_unexpected_init(
1265 const struct sctp_endpoint *ep,
1266 const struct sctp_association *asoc,
1267 const sctp_subtype_t type,
1268 void *arg, sctp_cmd_seq_t *commands)
1269{
1270 sctp_disposition_t retval;
1271 struct sctp_chunk *chunk = arg;
1272 struct sctp_chunk *repl;
1273 struct sctp_association *new_asoc;
1274 struct sctp_chunk *err_chunk;
1275 struct sctp_packet *packet;
1276 sctp_unrecognized_param_t *unk_param;
1277 int len;
1278
1279 /* 6.10 Bundling
1280 * An endpoint MUST NOT bundle INIT, INIT ACK or
1281 * SHUTDOWN COMPLETE with any other chunks.
1282 *
1283 * IG Section 2.11.2
1284 * Furthermore, we require that the receiver of an INIT chunk MUST
1285 * enforce these rules by silently discarding an arriving packet
1286 * with an INIT chunk that is bundled with other chunks.
1287 */
1288 if (!chunk->singleton)
1289 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1290
1291 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
1292 * Tag.
1293 */
1294 if (chunk->sctp_hdr->vtag != 0)
1295 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
1296
1297 /* Make sure that the INIT chunk has a valid length.
1298 * In this case, we generate a protocol violation since we have
1299 * an association established.
1300 */
1301 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
1302 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1303 commands);
1304 /* Grab the INIT header. */
1305 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
1306
1307 /* Tag the variable length parameters. */
1308 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
1309
1310 /* Verify the INIT chunk before processing it. */
1311 err_chunk = NULL;
1312 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
1313 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
1314 &err_chunk)) {
1315 /* This chunk contains fatal error. It is to be discarded.
1316 * Send an ABORT, with causes if there is any.
1317 */
1318 if (err_chunk) {
1319 packet = sctp_abort_pkt_new(ep, asoc, arg,
1320 (__u8 *)(err_chunk->chunk_hdr) +
1321 sizeof(sctp_chunkhdr_t),
1322 ntohs(err_chunk->chunk_hdr->length) -
1323 sizeof(sctp_chunkhdr_t));
1324
1325 if (packet) {
1326 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
1327 SCTP_PACKET(packet));
1328 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
1329 retval = SCTP_DISPOSITION_CONSUME;
1330 } else {
1331 retval = SCTP_DISPOSITION_NOMEM;
1332 }
1333 goto cleanup;
1334 } else {
1335 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg,
1336 commands);
1337 }
1338 }
1339
1340 /*
1341 * Other parameters for the endpoint SHOULD be copied from the
1342 * existing parameters of the association (e.g. number of
1343 * outbound streams) into the INIT ACK and cookie.
1344 * FIXME: We are copying parameters from the endpoint not the
1345 * association.
1346 */
1347 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
1348 if (!new_asoc)
1349 goto nomem;
1350
1351 /* In the outbound INIT ACK the endpoint MUST copy its current
1352 * Verification Tag and Peers Verification tag into a reserved
1353 * place (local tie-tag and per tie-tag) within the state cookie.
1354 */
1355 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
1356 sctp_source(chunk),
1357 (sctp_init_chunk_t *)chunk->chunk_hdr,
1358 GFP_ATOMIC)) {
1359 retval = SCTP_DISPOSITION_NOMEM;
1360 goto nomem_init;
1361 }
1362
1363 /* Make sure no new addresses are being added during the
1364 * restart. Do not do this check for COOKIE-WAIT state,
1365 * since there are no peer addresses to check against.
1366 * Upon return an ABORT will have been sent if needed.
1367 */
1368 if (!sctp_state(asoc, COOKIE_WAIT)) {
1369 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk,
1370 commands)) {
1371 retval = SCTP_DISPOSITION_CONSUME;
1372 goto cleanup_asoc;
1373 }
1374 }
1375
1376 sctp_tietags_populate(new_asoc, asoc);
1377
1378 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
1379
1380 /* If there are errors need to be reported for unknown parameters,
1381 * make sure to reserve enough room in the INIT ACK for them.
1382 */
1383 len = 0;
1384 if (err_chunk) {
1385 len = ntohs(err_chunk->chunk_hdr->length) -
1386 sizeof(sctp_chunkhdr_t);
1387 }
1388
1389 if (sctp_assoc_set_bind_addr_from_ep(new_asoc, GFP_ATOMIC) < 0)
1390 goto nomem;
1391
1392 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
1393 if (!repl)
1394 goto nomem;
1395
1396 /* If there are errors need to be reported for unknown parameters,
1397 * include them in the outgoing INIT ACK as "Unrecognized parameter"
1398 * parameter.
1399 */
1400 if (err_chunk) {
1401 /* Get the "Unrecognized parameter" parameter(s) out of the
1402 * ERROR chunk generated by sctp_verify_init(). Since the
1403 * error cause code for "unknown parameter" and the
1404 * "Unrecognized parameter" type is the same, we can
1405 * construct the parameters in INIT ACK by copying the
1406 * ERROR causes over.
1407 */
1408 unk_param = (sctp_unrecognized_param_t *)
1409 ((__u8 *)(err_chunk->chunk_hdr) +
1410 sizeof(sctp_chunkhdr_t));
1411 /* Replace the cause code with the "Unrecognized parameter"
1412 * parameter type.
1413 */
1414 sctp_addto_chunk(repl, len, unk_param);
1415 }
1416
1417 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
1418 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1419
1420 /*
1421 * Note: After sending out INIT ACK with the State Cookie parameter,
1422 * "Z" MUST NOT allocate any resources for this new association.
1423 * Otherwise, "Z" will be vulnerable to resource attacks.
1424 */
1425 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
1426 retval = SCTP_DISPOSITION_CONSUME;
1427
1428cleanup:
1429 if (err_chunk)
1430 sctp_chunk_free(err_chunk);
1431 return retval;
1432nomem:
1433 retval = SCTP_DISPOSITION_NOMEM;
1434 goto cleanup;
1435nomem_init:
1436cleanup_asoc:
1437 sctp_association_free(new_asoc);
1438 goto cleanup;
1439}
1440
1441/*
1442 * Handle simultanous INIT.
1443 * This means we started an INIT and then we got an INIT request from
1444 * our peer.
1445 *
1446 * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B)
1447 * This usually indicates an initialization collision, i.e., each
1448 * endpoint is attempting, at about the same time, to establish an
1449 * association with the other endpoint.
1450 *
1451 * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an
1452 * endpoint MUST respond with an INIT ACK using the same parameters it
1453 * sent in its original INIT chunk (including its Verification Tag,
1454 * unchanged). These original parameters are combined with those from the
1455 * newly received INIT chunk. The endpoint shall also generate a State
1456 * Cookie with the INIT ACK. The endpoint uses the parameters sent in its
1457 * INIT to calculate the State Cookie.
1458 *
1459 * After that, the endpoint MUST NOT change its state, the T1-init
1460 * timer shall be left running and the corresponding TCB MUST NOT be
1461 * destroyed. The normal procedures for handling State Cookies when
1462 * a TCB exists will resolve the duplicate INITs to a single association.
1463 *
1464 * For an endpoint that is in the COOKIE-ECHOED state it MUST populate
1465 * its Tie-Tags with the Tag information of itself and its peer (see
1466 * section 5.2.2 for a description of the Tie-Tags).
1467 *
1468 * Verification Tag: Not explicit, but an INIT can not have a valid
1469 * verification tag, so we skip the check.
1470 *
1471 * Inputs
1472 * (endpoint, asoc, chunk)
1473 *
1474 * Outputs
1475 * (asoc, reply_msg, msg_up, timers, counters)
1476 *
1477 * The return value is the disposition of the chunk.
1478 */
1479sctp_disposition_t sctp_sf_do_5_2_1_siminit(const struct sctp_endpoint *ep,
1480 const struct sctp_association *asoc,
1481 const sctp_subtype_t type,
1482 void *arg,
1483 sctp_cmd_seq_t *commands)
1484{
1485 /* Call helper to do the real work for both simulataneous and
1486 * duplicate INIT chunk handling.
1487 */
1488 return sctp_sf_do_unexpected_init(ep, asoc, type, arg, commands);
1489}
1490
1491/*
1492 * Handle duplicated INIT messages. These are usually delayed
1493 * restransmissions.
1494 *
1495 * Section: 5.2.2 Unexpected INIT in States Other than CLOSED,
1496 * COOKIE-ECHOED and COOKIE-WAIT
1497 *
1498 * Unless otherwise stated, upon reception of an unexpected INIT for
1499 * this association, the endpoint shall generate an INIT ACK with a
1500 * State Cookie. In the outbound INIT ACK the endpoint MUST copy its
1501 * current Verification Tag and peer's Verification Tag into a reserved
1502 * place within the state cookie. We shall refer to these locations as
1503 * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet
1504 * containing this INIT ACK MUST carry a Verification Tag value equal to
1505 * the Initiation Tag found in the unexpected INIT. And the INIT ACK
1506 * MUST contain a new Initiation Tag (randomly generated see Section
1507 * 5.3.1). Other parameters for the endpoint SHOULD be copied from the
1508 * existing parameters of the association (e.g. number of outbound
1509 * streams) into the INIT ACK and cookie.
1510 *
1511 * After sending out the INIT ACK, the endpoint shall take no further
1512 * actions, i.e., the existing association, including its current state,
1513 * and the corresponding TCB MUST NOT be changed.
1514 *
1515 * Note: Only when a TCB exists and the association is not in a COOKIE-
1516 * WAIT state are the Tie-Tags populated. For a normal association INIT
1517 * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be
1518 * set to 0 (indicating that no previous TCB existed). The INIT ACK and
1519 * State Cookie are populated as specified in section 5.2.1.
1520 *
1521 * Verification Tag: Not specified, but an INIT has no way of knowing
1522 * what the verification tag could be, so we ignore it.
1523 *
1524 * Inputs
1525 * (endpoint, asoc, chunk)
1526 *
1527 * Outputs
1528 * (asoc, reply_msg, msg_up, timers, counters)
1529 *
1530 * The return value is the disposition of the chunk.
1531 */
1532sctp_disposition_t sctp_sf_do_5_2_2_dupinit(const struct sctp_endpoint *ep,
1533 const struct sctp_association *asoc,
1534 const sctp_subtype_t type,
1535 void *arg,
1536 sctp_cmd_seq_t *commands)
1537{
1538 /* Call helper to do the real work for both simulataneous and
1539 * duplicate INIT chunk handling.
1540 */
1541 return sctp_sf_do_unexpected_init(ep, asoc, type, arg, commands);
1542}
1543
1544
1545
1546/* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A')
1547 *
1548 * Section 5.2.4
1549 * A) In this case, the peer may have restarted.
1550 */
1551static sctp_disposition_t sctp_sf_do_dupcook_a(const struct sctp_endpoint *ep,
1552 const struct sctp_association *asoc,
1553 struct sctp_chunk *chunk,
1554 sctp_cmd_seq_t *commands,
1555 struct sctp_association *new_asoc)
1556{
1557 sctp_init_chunk_t *peer_init;
1558 struct sctp_ulpevent *ev;
1559 struct sctp_chunk *repl;
1560 struct sctp_chunk *err;
1561 sctp_disposition_t disposition;
1562
1563 /* new_asoc is a brand-new association, so these are not yet
1564 * side effects--it is safe to run them here.
1565 */
1566 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1567
1568 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
1569 sctp_source(chunk), peer_init,
1570 GFP_ATOMIC))
1571 goto nomem;
1572
1573 /* Make sure no new addresses are being added during the
1574 * restart. Though this is a pretty complicated attack
1575 * since you'd have to get inside the cookie.
1576 */
1577 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk, commands)) {
1578 return SCTP_DISPOSITION_CONSUME;
1579 }
1580
1581 /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes
1582 * the peer has restarted (Action A), it MUST NOT setup a new
1583 * association but instead resend the SHUTDOWN ACK and send an ERROR
1584 * chunk with a "Cookie Received while Shutting Down" error cause to
1585 * its peer.
1586 */
1587 if (sctp_state(asoc, SHUTDOWN_ACK_SENT)) {
1588 disposition = sctp_sf_do_9_2_reshutack(ep, asoc,
1589 SCTP_ST_CHUNK(chunk->chunk_hdr->type),
1590 chunk, commands);
1591 if (SCTP_DISPOSITION_NOMEM == disposition)
1592 goto nomem;
1593
1594 err = sctp_make_op_error(asoc, chunk,
1595 SCTP_ERROR_COOKIE_IN_SHUTDOWN,
1596 NULL, 0);
1597 if (err)
1598 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1599 SCTP_CHUNK(err));
1600
1601 return SCTP_DISPOSITION_CONSUME;
1602 }
1603
1604 /* For now, fail any unsent/unacked data. Consider the optional
1605 * choice of resending of this data.
1606 */
1607 sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_OUTQUEUE, SCTP_NULL());
1608
1609 /* Update the content of current association. */
1610 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1611
1612 repl = sctp_make_cookie_ack(new_asoc, chunk);
1613 if (!repl)
1614 goto nomem;
1615
1616 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1617
1618 /* Report association restart to upper layer. */
1619 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_RESTART, 0,
1620 new_asoc->c.sinit_num_ostreams,
1621 new_asoc->c.sinit_max_instreams,
1622 GFP_ATOMIC);
1623 if (!ev)
1624 goto nomem_ev;
1625
1626 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
1627 return SCTP_DISPOSITION_CONSUME;
1628
1629nomem_ev:
1630 sctp_chunk_free(repl);
1631nomem:
1632 return SCTP_DISPOSITION_NOMEM;
1633}
1634
1635/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B')
1636 *
1637 * Section 5.2.4
1638 * B) In this case, both sides may be attempting to start an association
1639 * at about the same time but the peer endpoint started its INIT
1640 * after responding to the local endpoint's INIT
1641 */
1642/* This case represents an initialization collision. */
1643static sctp_disposition_t sctp_sf_do_dupcook_b(const struct sctp_endpoint *ep,
1644 const struct sctp_association *asoc,
1645 struct sctp_chunk *chunk,
1646 sctp_cmd_seq_t *commands,
1647 struct sctp_association *new_asoc)
1648{
1649 sctp_init_chunk_t *peer_init;
1650 struct sctp_ulpevent *ev;
1651 struct sctp_chunk *repl;
1652
1653 /* new_asoc is a brand-new association, so these are not yet
1654 * side effects--it is safe to run them here.
1655 */
1656 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1657 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
1658 sctp_source(chunk), peer_init,
1659 GFP_ATOMIC))
1660 goto nomem;
1661
1662 /* Update the content of current association. */
1663 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1664 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1665 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1666 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
1667 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
1668
1669 repl = sctp_make_cookie_ack(new_asoc, chunk);
1670 if (!repl)
1671 goto nomem;
1672
1673 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1674 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
1675
1676 /* RFC 2960 5.1 Normal Establishment of an Association
1677 *
1678 * D) IMPLEMENTATION NOTE: An implementation may choose to
1679 * send the Communication Up notification to the SCTP user
1680 * upon reception of a valid COOKIE ECHO chunk.
1681 */
1682 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP, 0,
1683 new_asoc->c.sinit_num_ostreams,
1684 new_asoc->c.sinit_max_instreams,
1685 GFP_ATOMIC);
1686 if (!ev)
1687 goto nomem_ev;
1688
1689 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
1690
1691 /* Sockets API Draft Section 5.3.1.6
1692 * When a peer sends a Adaption Layer Indication parameter , SCTP
1693 * delivers this notification to inform the application that of the
1694 * peers requested adaption layer.
1695 */
1696 if (asoc->peer.adaption_ind) {
1697 ev = sctp_ulpevent_make_adaption_indication(asoc, GFP_ATOMIC);
1698 if (!ev)
1699 goto nomem_ev;
1700
1701 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1702 SCTP_ULPEVENT(ev));
1703 }
1704
1705 return SCTP_DISPOSITION_CONSUME;
1706
1707nomem_ev:
1708 sctp_chunk_free(repl);
1709nomem:
1710 return SCTP_DISPOSITION_NOMEM;
1711}
1712
1713/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C')
1714 *
1715 * Section 5.2.4
1716 * C) In this case, the local endpoint's cookie has arrived late.
1717 * Before it arrived, the local endpoint sent an INIT and received an
1718 * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag
1719 * but a new tag of its own.
1720 */
1721/* This case represents an initialization collision. */
1722static sctp_disposition_t sctp_sf_do_dupcook_c(const struct sctp_endpoint *ep,
1723 const struct sctp_association *asoc,
1724 struct sctp_chunk *chunk,
1725 sctp_cmd_seq_t *commands,
1726 struct sctp_association *new_asoc)
1727{
1728 /* The cookie should be silently discarded.
1729 * The endpoint SHOULD NOT change states and should leave
1730 * any timers running.
1731 */
1732 return SCTP_DISPOSITION_DISCARD;
1733}
1734
1735/* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D')
1736 *
1737 * Section 5.2.4
1738 *
1739 * D) When both local and remote tags match the endpoint should always
1740 * enter the ESTABLISHED state, if it has not already done so.
1741 */
1742/* This case represents an initialization collision. */
1743static sctp_disposition_t sctp_sf_do_dupcook_d(const struct sctp_endpoint *ep,
1744 const struct sctp_association *asoc,
1745 struct sctp_chunk *chunk,
1746 sctp_cmd_seq_t *commands,
1747 struct sctp_association *new_asoc)
1748{
1749 struct sctp_ulpevent *ev = NULL;
1750 struct sctp_chunk *repl;
1751
1752 /* Clarification from Implementor's Guide:
1753 * D) When both local and remote tags match the endpoint should
1754 * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state.
1755 * It should stop any cookie timer that may be running and send
1756 * a COOKIE ACK.
1757 */
1758
1759 /* Don't accidentally move back into established state. */
1760 if (asoc->state < SCTP_STATE_ESTABLISHED) {
1761 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1762 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1763 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1764 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1765 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
1766 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START,
1767 SCTP_NULL());
1768
1769 /* RFC 2960 5.1 Normal Establishment of an Association
1770 *
1771 * D) IMPLEMENTATION NOTE: An implementation may choose
1772 * to send the Communication Up notification to the
1773 * SCTP user upon reception of a valid COOKIE
1774 * ECHO chunk.
1775 */
1776 ev = sctp_ulpevent_make_assoc_change(new_asoc, 0,
1777 SCTP_COMM_UP, 0,
1778 new_asoc->c.sinit_num_ostreams,
1779 new_asoc->c.sinit_max_instreams,
1780 GFP_ATOMIC);
1781 if (!ev)
1782 goto nomem;
1783 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1784 SCTP_ULPEVENT(ev));
1785
1786 /* Sockets API Draft Section 5.3.1.6
1787 * When a peer sends a Adaption Layer Indication parameter,
1788 * SCTP delivers this notification to inform the application
1789 * that of the peers requested adaption layer.
1790 */
1791 if (new_asoc->peer.adaption_ind) {
1792 ev = sctp_ulpevent_make_adaption_indication(new_asoc,
1793 GFP_ATOMIC);
1794 if (!ev)
1795 goto nomem;
1796
1797 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1798 SCTP_ULPEVENT(ev));
1799 }
1800 }
1801 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
1802
1803 repl = sctp_make_cookie_ack(new_asoc, chunk);
1804 if (!repl)
1805 goto nomem;
1806
1807 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1808 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
1809
1810 return SCTP_DISPOSITION_CONSUME;
1811
1812nomem:
1813 if (ev)
1814 sctp_ulpevent_free(ev);
1815 return SCTP_DISPOSITION_NOMEM;
1816}
1817
1818/*
1819 * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying
1820 * chunk was retransmitted and then delayed in the network.
1821 *
1822 * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists
1823 *
1824 * Verification Tag: None. Do cookie validation.
1825 *
1826 * Inputs
1827 * (endpoint, asoc, chunk)
1828 *
1829 * Outputs
1830 * (asoc, reply_msg, msg_up, timers, counters)
1831 *
1832 * The return value is the disposition of the chunk.
1833 */
1834sctp_disposition_t sctp_sf_do_5_2_4_dupcook(const struct sctp_endpoint *ep,
1835 const struct sctp_association *asoc,
1836 const sctp_subtype_t type,
1837 void *arg,
1838 sctp_cmd_seq_t *commands)
1839{
1840 sctp_disposition_t retval;
1841 struct sctp_chunk *chunk = arg;
1842 struct sctp_association *new_asoc;
1843 int error = 0;
1844 char action;
1845 struct sctp_chunk *err_chk_p;
1846
1847 /* Make sure that the chunk has a valid length from the protocol
1848 * perspective. In this case check to make sure we have at least
1849 * enough for the chunk header. Cookie length verification is
1850 * done later.
1851 */
1852 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
1853 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1854 commands);
1855
1856 /* "Decode" the chunk. We have no optional parameters so we
1857 * are in good shape.
1858 */
1859 chunk->subh.cookie_hdr = (struct sctp_signed_cookie *)chunk->skb->data;
Sridhar Samudrala62b08082006-05-05 17:04:43 -07001860 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
1861 sizeof(sctp_chunkhdr_t)))
1862 goto nomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001863
1864 /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
1865 * of a duplicate COOKIE ECHO match the Verification Tags of the
1866 * current association, consider the State Cookie valid even if
1867 * the lifespan is exceeded.
1868 */
1869 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
1870 &err_chk_p);
1871
1872 /* FIXME:
1873 * If the re-build failed, what is the proper error path
1874 * from here?
1875 *
1876 * [We should abort the association. --piggy]
1877 */
1878 if (!new_asoc) {
1879 /* FIXME: Several errors are possible. A bad cookie should
1880 * be silently discarded, but think about logging it too.
1881 */
1882 switch (error) {
1883 case -SCTP_IERROR_NOMEM:
1884 goto nomem;
1885
1886 case -SCTP_IERROR_STALE_COOKIE:
1887 sctp_send_stale_cookie_err(ep, asoc, chunk, commands,
1888 err_chk_p);
1889 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1890 case -SCTP_IERROR_BAD_SIG:
1891 default:
1892 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1893 };
1894 }
1895
1896 /* Compare the tie_tag in cookie with the verification tag of
1897 * current association.
1898 */
1899 action = sctp_tietags_compare(new_asoc, asoc);
1900
1901 switch (action) {
1902 case 'A': /* Association restart. */
1903 retval = sctp_sf_do_dupcook_a(ep, asoc, chunk, commands,
1904 new_asoc);
1905 break;
1906
1907 case 'B': /* Collision case B. */
1908 retval = sctp_sf_do_dupcook_b(ep, asoc, chunk, commands,
1909 new_asoc);
1910 break;
1911
1912 case 'C': /* Collision case C. */
1913 retval = sctp_sf_do_dupcook_c(ep, asoc, chunk, commands,
1914 new_asoc);
1915 break;
1916
1917 case 'D': /* Collision case D. */
1918 retval = sctp_sf_do_dupcook_d(ep, asoc, chunk, commands,
1919 new_asoc);
1920 break;
1921
1922 default: /* Discard packet for all others. */
1923 retval = sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1924 break;
1925 };
1926
1927 /* Delete the tempory new association. */
1928 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
1929 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
1930
1931 return retval;
1932
1933nomem:
1934 return SCTP_DISPOSITION_NOMEM;
1935}
1936
1937/*
1938 * Process an ABORT. (SHUTDOWN-PENDING state)
1939 *
1940 * See sctp_sf_do_9_1_abort().
1941 */
1942sctp_disposition_t sctp_sf_shutdown_pending_abort(
1943 const struct sctp_endpoint *ep,
1944 const struct sctp_association *asoc,
1945 const sctp_subtype_t type,
1946 void *arg,
1947 sctp_cmd_seq_t *commands)
1948{
1949 struct sctp_chunk *chunk = arg;
1950
1951 if (!sctp_vtag_verify_either(chunk, asoc))
1952 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1953
1954 /* Make sure that the ABORT chunk has a valid length.
1955 * Since this is an ABORT chunk, we have to discard it
1956 * because of the following text:
1957 * RFC 2960, Section 3.3.7
1958 * If an endpoint receives an ABORT with a format error or for an
1959 * association that doesn't exist, it MUST silently discard it.
1960 * Becasue the length is "invalid", we can't really discard just
1961 * as we do not know its true length. So, to be safe, discard the
1962 * packet.
1963 */
1964 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
1965 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1966
1967 /* Stop the T5-shutdown guard timer. */
1968 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1969 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
1970
1971 return sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
1972}
1973
1974/*
1975 * Process an ABORT. (SHUTDOWN-SENT state)
1976 *
1977 * See sctp_sf_do_9_1_abort().
1978 */
1979sctp_disposition_t sctp_sf_shutdown_sent_abort(const struct sctp_endpoint *ep,
1980 const struct sctp_association *asoc,
1981 const sctp_subtype_t type,
1982 void *arg,
1983 sctp_cmd_seq_t *commands)
1984{
1985 struct sctp_chunk *chunk = arg;
1986
1987 if (!sctp_vtag_verify_either(chunk, asoc))
1988 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1989
1990 /* Make sure that the ABORT chunk has a valid length.
1991 * Since this is an ABORT chunk, we have to discard it
1992 * because of the following text:
1993 * RFC 2960, Section 3.3.7
1994 * If an endpoint receives an ABORT with a format error or for an
1995 * association that doesn't exist, it MUST silently discard it.
1996 * Becasue the length is "invalid", we can't really discard just
1997 * as we do not know its true length. So, to be safe, discard the
1998 * packet.
1999 */
2000 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2001 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2002
2003 /* Stop the T2-shutdown timer. */
2004 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2005 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2006
2007 /* Stop the T5-shutdown guard timer. */
2008 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2009 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
2010
2011 return sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
2012}
2013
2014/*
2015 * Process an ABORT. (SHUTDOWN-ACK-SENT state)
2016 *
2017 * See sctp_sf_do_9_1_abort().
2018 */
2019sctp_disposition_t sctp_sf_shutdown_ack_sent_abort(
2020 const struct sctp_endpoint *ep,
2021 const struct sctp_association *asoc,
2022 const sctp_subtype_t type,
2023 void *arg,
2024 sctp_cmd_seq_t *commands)
2025{
2026 /* The same T2 timer, so we should be able to use
2027 * common function with the SHUTDOWN-SENT state.
2028 */
2029 return sctp_sf_shutdown_sent_abort(ep, asoc, type, arg, commands);
2030}
2031
2032/*
2033 * Handle an Error received in COOKIE_ECHOED state.
2034 *
2035 * Only handle the error type of stale COOKIE Error, the other errors will
2036 * be ignored.
2037 *
2038 * Inputs
2039 * (endpoint, asoc, chunk)
2040 *
2041 * Outputs
2042 * (asoc, reply_msg, msg_up, timers, counters)
2043 *
2044 * The return value is the disposition of the chunk.
2045 */
2046sctp_disposition_t sctp_sf_cookie_echoed_err(const struct sctp_endpoint *ep,
2047 const struct sctp_association *asoc,
2048 const sctp_subtype_t type,
2049 void *arg,
2050 sctp_cmd_seq_t *commands)
2051{
2052 struct sctp_chunk *chunk = arg;
2053 sctp_errhdr_t *err;
2054
2055 if (!sctp_vtag_verify(chunk, asoc))
2056 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2057
2058 /* Make sure that the ERROR chunk has a valid length.
2059 * The parameter walking depends on this as well.
2060 */
2061 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
2062 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2063 commands);
2064
2065 /* Process the error here */
2066 /* FUTURE FIXME: When PR-SCTP related and other optional
2067 * parms are emitted, this will have to change to handle multiple
2068 * errors.
2069 */
2070 sctp_walk_errors(err, chunk->chunk_hdr) {
2071 if (SCTP_ERROR_STALE_COOKIE == err->cause)
2072 return sctp_sf_do_5_2_6_stale(ep, asoc, type,
2073 arg, commands);
2074 }
2075
2076 /* It is possible to have malformed error causes, and that
2077 * will cause us to end the walk early. However, since
2078 * we are discarding the packet, there should be no adverse
2079 * affects.
2080 */
2081 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2082}
2083
2084/*
2085 * Handle a Stale COOKIE Error
2086 *
2087 * Section: 5.2.6 Handle Stale COOKIE Error
2088 * If the association is in the COOKIE-ECHOED state, the endpoint may elect
2089 * one of the following three alternatives.
2090 * ...
2091 * 3) Send a new INIT chunk to the endpoint, adding a Cookie
2092 * Preservative parameter requesting an extension to the lifetime of
2093 * the State Cookie. When calculating the time extension, an
2094 * implementation SHOULD use the RTT information measured based on the
2095 * previous COOKIE ECHO / ERROR exchange, and should add no more
2096 * than 1 second beyond the measured RTT, due to long State Cookie
2097 * lifetimes making the endpoint more subject to a replay attack.
2098 *
2099 * Verification Tag: Not explicit, but safe to ignore.
2100 *
2101 * Inputs
2102 * (endpoint, asoc, chunk)
2103 *
2104 * Outputs
2105 * (asoc, reply_msg, msg_up, timers, counters)
2106 *
2107 * The return value is the disposition of the chunk.
2108 */
2109static sctp_disposition_t sctp_sf_do_5_2_6_stale(const struct sctp_endpoint *ep,
2110 const struct sctp_association *asoc,
2111 const sctp_subtype_t type,
2112 void *arg,
2113 sctp_cmd_seq_t *commands)
2114{
2115 struct sctp_chunk *chunk = arg;
2116 time_t stale;
2117 sctp_cookie_preserve_param_t bht;
2118 sctp_errhdr_t *err;
2119 struct sctp_chunk *reply;
2120 struct sctp_bind_addr *bp;
Frank Filz3f7a87d2005-06-20 13:14:57 -07002121 int attempts = asoc->init_err_counter + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002122
Vlad Yasevich81845c22006-01-30 15:59:54 -08002123 if (attempts > asoc->max_init_attempts) {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002124 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
2125 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002126 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
2127 SCTP_U32(SCTP_ERROR_STALE_COOKIE));
2128 return SCTP_DISPOSITION_DELETE_TCB;
2129 }
2130
2131 err = (sctp_errhdr_t *)(chunk->skb->data);
2132
2133 /* When calculating the time extension, an implementation
2134 * SHOULD use the RTT information measured based on the
2135 * previous COOKIE ECHO / ERROR exchange, and should add no
2136 * more than 1 second beyond the measured RTT, due to long
2137 * State Cookie lifetimes making the endpoint more subject to
2138 * a replay attack.
2139 * Measure of Staleness's unit is usec. (1/1000000 sec)
2140 * Suggested Cookie Life-span Increment's unit is msec.
2141 * (1/1000 sec)
2142 * In general, if you use the suggested cookie life, the value
2143 * found in the field of measure of staleness should be doubled
2144 * to give ample time to retransmit the new cookie and thus
2145 * yield a higher probability of success on the reattempt.
2146 */
2147 stale = ntohl(*(suseconds_t *)((u8 *)err + sizeof(sctp_errhdr_t)));
2148 stale = (stale * 2) / 1000;
2149
2150 bht.param_hdr.type = SCTP_PARAM_COOKIE_PRESERVATIVE;
2151 bht.param_hdr.length = htons(sizeof(bht));
2152 bht.lifespan_increment = htonl(stale);
2153
2154 /* Build that new INIT chunk. */
2155 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
2156 reply = sctp_make_init(asoc, bp, GFP_ATOMIC, sizeof(bht));
2157 if (!reply)
2158 goto nomem;
2159
2160 sctp_addto_chunk(reply, sizeof(bht), &bht);
2161
2162 /* Clear peer's init_tag cached in assoc as we are sending a new INIT */
2163 sctp_add_cmd_sf(commands, SCTP_CMD_CLEAR_INIT_TAG, SCTP_NULL());
2164
2165 /* Stop pending T3-rtx and heartbeat timers */
2166 sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
2167 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
2168
2169 /* Delete non-primary peer ip addresses since we are transitioning
2170 * back to the COOKIE-WAIT state
2171 */
2172 sctp_add_cmd_sf(commands, SCTP_CMD_DEL_NON_PRIMARY, SCTP_NULL());
2173
2174 /* If we've sent any data bundled with COOKIE-ECHO we will need to
2175 * resend
2176 */
2177 sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN,
2178 SCTP_TRANSPORT(asoc->peer.primary_path));
2179
2180 /* Cast away the const modifier, as we want to just
2181 * rerun it through as a sideffect.
2182 */
Frank Filz3f7a87d2005-06-20 13:14:57 -07002183 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_INC, SCTP_NULL());
Linus Torvalds1da177e2005-04-16 15:20:36 -07002184
2185 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2186 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
2187 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2188 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
2189 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
2190 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
2191
2192 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2193
2194 return SCTP_DISPOSITION_CONSUME;
2195
2196nomem:
2197 return SCTP_DISPOSITION_NOMEM;
2198}
2199
2200/*
2201 * Process an ABORT.
2202 *
2203 * Section: 9.1
2204 * After checking the Verification Tag, the receiving endpoint shall
2205 * remove the association from its record, and shall report the
2206 * termination to its upper layer.
2207 *
2208 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
2209 * B) Rules for packet carrying ABORT:
2210 *
2211 * - The endpoint shall always fill in the Verification Tag field of the
2212 * outbound packet with the destination endpoint's tag value if it
2213 * is known.
2214 *
2215 * - If the ABORT is sent in response to an OOTB packet, the endpoint
2216 * MUST follow the procedure described in Section 8.4.
2217 *
2218 * - The receiver MUST accept the packet if the Verification Tag
2219 * matches either its own tag, OR the tag of its peer. Otherwise, the
2220 * receiver MUST silently discard the packet and take no further
2221 * action.
2222 *
2223 * Inputs
2224 * (endpoint, asoc, chunk)
2225 *
2226 * Outputs
2227 * (asoc, reply_msg, msg_up, timers, counters)
2228 *
2229 * The return value is the disposition of the chunk.
2230 */
2231sctp_disposition_t sctp_sf_do_9_1_abort(const struct sctp_endpoint *ep,
2232 const struct sctp_association *asoc,
2233 const sctp_subtype_t type,
2234 void *arg,
2235 sctp_cmd_seq_t *commands)
2236{
2237 struct sctp_chunk *chunk = arg;
2238 unsigned len;
2239 __u16 error = SCTP_ERROR_NO_ERROR;
2240
2241 if (!sctp_vtag_verify_either(chunk, asoc))
2242 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2243
2244 /* Make sure that the ABORT chunk has a valid length.
2245 * Since this is an ABORT chunk, we have to discard it
2246 * because of the following text:
2247 * RFC 2960, Section 3.3.7
2248 * If an endpoint receives an ABORT with a format error or for an
2249 * association that doesn't exist, it MUST silently discard it.
2250 * Becasue the length is "invalid", we can't really discard just
2251 * as we do not know its true length. So, to be safe, discard the
2252 * packet.
2253 */
2254 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2255 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2256
2257 /* See if we have an error cause code in the chunk. */
2258 len = ntohs(chunk->chunk_hdr->length);
2259 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
2260 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2261
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002262 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNRESET));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002263 /* ASSOC_FAILED will DELETE_TCB. */
2264 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, SCTP_U32(error));
2265 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
2266 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
2267
2268 return SCTP_DISPOSITION_ABORT;
2269}
2270
2271/*
2272 * Process an ABORT. (COOKIE-WAIT state)
2273 *
2274 * See sctp_sf_do_9_1_abort() above.
2275 */
2276sctp_disposition_t sctp_sf_cookie_wait_abort(const struct sctp_endpoint *ep,
2277 const struct sctp_association *asoc,
2278 const sctp_subtype_t type,
2279 void *arg,
2280 sctp_cmd_seq_t *commands)
2281{
2282 struct sctp_chunk *chunk = arg;
2283 unsigned len;
2284 __u16 error = SCTP_ERROR_NO_ERROR;
2285
2286 if (!sctp_vtag_verify_either(chunk, asoc))
2287 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2288
2289 /* Make sure that the ABORT chunk has a valid length.
2290 * Since this is an ABORT chunk, we have to discard it
2291 * because of the following text:
2292 * RFC 2960, Section 3.3.7
2293 * If an endpoint receives an ABORT with a format error or for an
2294 * association that doesn't exist, it MUST silently discard it.
2295 * Becasue the length is "invalid", we can't really discard just
2296 * as we do not know its true length. So, to be safe, discard the
2297 * packet.
2298 */
2299 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2300 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2301
2302 /* See if we have an error cause code in the chunk. */
2303 len = ntohs(chunk->chunk_hdr->length);
2304 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
2305 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2306
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002307 return sctp_stop_t1_and_abort(commands, error, ECONNREFUSED, asoc,
2308 chunk->transport);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002309}
2310
2311/*
2312 * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state)
2313 */
2314sctp_disposition_t sctp_sf_cookie_wait_icmp_abort(const struct sctp_endpoint *ep,
2315 const struct sctp_association *asoc,
2316 const sctp_subtype_t type,
2317 void *arg,
2318 sctp_cmd_seq_t *commands)
2319{
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002320 return sctp_stop_t1_and_abort(commands, SCTP_ERROR_NO_ERROR,
2321 ENOPROTOOPT, asoc,
Frank Filz3f7a87d2005-06-20 13:14:57 -07002322 (struct sctp_transport *)arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002323}
2324
2325/*
2326 * Process an ABORT. (COOKIE-ECHOED state)
2327 */
2328sctp_disposition_t sctp_sf_cookie_echoed_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{
2334 /* There is a single T1 timer, so we should be able to use
2335 * common function with the COOKIE-WAIT state.
2336 */
2337 return sctp_sf_cookie_wait_abort(ep, asoc, type, arg, commands);
2338}
2339
2340/*
2341 * Stop T1 timer and abort association with "INIT failed".
2342 *
2343 * This is common code called by several sctp_sf_*_abort() functions above.
2344 */
Adrian Bunk52c1da32005-06-23 22:05:33 -07002345static sctp_disposition_t sctp_stop_t1_and_abort(sctp_cmd_seq_t *commands,
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002346 __u16 error, int sk_err,
Frank Filz3f7a87d2005-06-20 13:14:57 -07002347 const struct sctp_association *asoc,
2348 struct sctp_transport *transport)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002349{
Frank Filz3f7a87d2005-06-20 13:14:57 -07002350 SCTP_DEBUG_PRINTK("ABORT received (INIT).\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07002351 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2352 SCTP_STATE(SCTP_STATE_CLOSED));
2353 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
2354 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2355 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07002356 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(sk_err));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002357 /* CMD_INIT_FAILED will DELETE_TCB. */
2358 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
2359 SCTP_U32(error));
Frank Filz3f7a87d2005-06-20 13:14:57 -07002360 return SCTP_DISPOSITION_ABORT;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002361}
2362
2363/*
2364 * sctp_sf_do_9_2_shut
2365 *
2366 * Section: 9.2
2367 * Upon the reception of the SHUTDOWN, the peer endpoint shall
2368 * - enter the SHUTDOWN-RECEIVED state,
2369 *
2370 * - stop accepting new data from its SCTP user
2371 *
2372 * - verify, by checking the Cumulative TSN Ack field of the chunk,
2373 * that all its outstanding DATA chunks have been received by the
2374 * SHUTDOWN sender.
2375 *
2376 * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT
2377 * send a SHUTDOWN in response to a ULP request. And should discard
2378 * subsequent SHUTDOWN chunks.
2379 *
2380 * If there are still outstanding DATA chunks left, the SHUTDOWN
2381 * receiver shall continue to follow normal data transmission
2382 * procedures defined in Section 6 until all outstanding DATA chunks
2383 * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept
2384 * new data from its SCTP user.
2385 *
2386 * Verification Tag: 8.5 Verification Tag [Normal verification]
2387 *
2388 * Inputs
2389 * (endpoint, asoc, chunk)
2390 *
2391 * Outputs
2392 * (asoc, reply_msg, msg_up, timers, counters)
2393 *
2394 * The return value is the disposition of the chunk.
2395 */
2396sctp_disposition_t sctp_sf_do_9_2_shutdown(const struct sctp_endpoint *ep,
2397 const struct sctp_association *asoc,
2398 const sctp_subtype_t type,
2399 void *arg,
2400 sctp_cmd_seq_t *commands)
2401{
2402 struct sctp_chunk *chunk = arg;
2403 sctp_shutdownhdr_t *sdh;
2404 sctp_disposition_t disposition;
2405 struct sctp_ulpevent *ev;
2406
2407 if (!sctp_vtag_verify(chunk, asoc))
2408 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2409
2410 /* Make sure that the SHUTDOWN chunk has a valid length. */
2411 if (!sctp_chunk_length_valid(chunk,
2412 sizeof(struct sctp_shutdown_chunk_t)))
2413 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2414 commands);
2415
2416 /* Convert the elaborate header. */
2417 sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
2418 skb_pull(chunk->skb, sizeof(sctp_shutdownhdr_t));
2419 chunk->subh.shutdown_hdr = sdh;
2420
Sridhar Samudralaeb0e0072005-09-22 23:48:38 -07002421 /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT
2422 * When a peer sends a SHUTDOWN, SCTP delivers this notification to
2423 * inform the application that it should cease sending data.
2424 */
2425 ev = sctp_ulpevent_make_shutdown_event(asoc, 0, GFP_ATOMIC);
2426 if (!ev) {
2427 disposition = SCTP_DISPOSITION_NOMEM;
2428 goto out;
2429 }
2430 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
2431
Linus Torvalds1da177e2005-04-16 15:20:36 -07002432 /* Upon the reception of the SHUTDOWN, the peer endpoint shall
2433 * - enter the SHUTDOWN-RECEIVED state,
2434 * - stop accepting new data from its SCTP user
2435 *
2436 * [This is implicit in the new state.]
2437 */
2438 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2439 SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED));
2440 disposition = SCTP_DISPOSITION_CONSUME;
2441
2442 if (sctp_outq_is_empty(&asoc->outqueue)) {
2443 disposition = sctp_sf_do_9_2_shutdown_ack(ep, asoc, type,
2444 arg, commands);
2445 }
2446
2447 if (SCTP_DISPOSITION_NOMEM == disposition)
2448 goto out;
2449
2450 /* - verify, by checking the Cumulative TSN Ack field of the
2451 * chunk, that all its outstanding DATA chunks have been
2452 * received by the SHUTDOWN sender.
2453 */
2454 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
2455 SCTP_U32(chunk->subh.shutdown_hdr->cum_tsn_ack));
2456
Linus Torvalds1da177e2005-04-16 15:20:36 -07002457out:
2458 return disposition;
2459}
2460
2461/* RFC 2960 9.2
2462 * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk
2463 * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination
2464 * transport addresses (either in the IP addresses or in the INIT chunk)
2465 * that belong to this association, it should discard the INIT chunk and
2466 * retransmit the SHUTDOWN ACK chunk.
2467 */
2468sctp_disposition_t sctp_sf_do_9_2_reshutack(const struct sctp_endpoint *ep,
2469 const struct sctp_association *asoc,
2470 const sctp_subtype_t type,
2471 void *arg,
2472 sctp_cmd_seq_t *commands)
2473{
2474 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
2475 struct sctp_chunk *reply;
2476
2477 /* Since we are not going to really process this INIT, there
2478 * is no point in verifying chunk boundries. Just generate
2479 * the SHUTDOWN ACK.
2480 */
2481 reply = sctp_make_shutdown_ack(asoc, chunk);
2482 if (NULL == reply)
2483 goto nomem;
2484
2485 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
2486 * the T2-SHUTDOWN timer.
2487 */
2488 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
2489
2490 /* and restart the T2-shutdown timer. */
2491 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2492 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2493
2494 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2495
2496 return SCTP_DISPOSITION_CONSUME;
2497nomem:
2498 return SCTP_DISPOSITION_NOMEM;
2499}
2500
2501/*
2502 * sctp_sf_do_ecn_cwr
2503 *
2504 * Section: Appendix A: Explicit Congestion Notification
2505 *
2506 * CWR:
2507 *
2508 * RFC 2481 details a specific bit for a sender to send in the header of
2509 * its next outbound TCP segment to indicate to its peer that it has
2510 * reduced its congestion window. This is termed the CWR bit. For
2511 * SCTP the same indication is made by including the CWR chunk.
2512 * This chunk contains one data element, i.e. the TSN number that
2513 * was sent in the ECNE chunk. This element represents the lowest
2514 * TSN number in the datagram that was originally marked with the
2515 * CE bit.
2516 *
2517 * Verification Tag: 8.5 Verification Tag [Normal verification]
2518 * Inputs
2519 * (endpoint, asoc, chunk)
2520 *
2521 * Outputs
2522 * (asoc, reply_msg, msg_up, timers, counters)
2523 *
2524 * The return value is the disposition of the chunk.
2525 */
2526sctp_disposition_t sctp_sf_do_ecn_cwr(const struct sctp_endpoint *ep,
2527 const struct sctp_association *asoc,
2528 const sctp_subtype_t type,
2529 void *arg,
2530 sctp_cmd_seq_t *commands)
2531{
2532 sctp_cwrhdr_t *cwr;
2533 struct sctp_chunk *chunk = arg;
2534
2535 if (!sctp_vtag_verify(chunk, asoc))
2536 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2537
2538 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2539 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2540 commands);
2541
2542 cwr = (sctp_cwrhdr_t *) chunk->skb->data;
2543 skb_pull(chunk->skb, sizeof(sctp_cwrhdr_t));
2544
2545 cwr->lowest_tsn = ntohl(cwr->lowest_tsn);
2546
2547 /* Does this CWR ack the last sent congestion notification? */
2548 if (TSN_lte(asoc->last_ecne_tsn, cwr->lowest_tsn)) {
2549 /* Stop sending ECNE. */
2550 sctp_add_cmd_sf(commands,
2551 SCTP_CMD_ECN_CWR,
2552 SCTP_U32(cwr->lowest_tsn));
2553 }
2554 return SCTP_DISPOSITION_CONSUME;
2555}
2556
2557/*
2558 * sctp_sf_do_ecne
2559 *
2560 * Section: Appendix A: Explicit Congestion Notification
2561 *
2562 * ECN-Echo
2563 *
2564 * RFC 2481 details a specific bit for a receiver to send back in its
2565 * TCP acknowledgements to notify the sender of the Congestion
2566 * Experienced (CE) bit having arrived from the network. For SCTP this
2567 * same indication is made by including the ECNE chunk. This chunk
2568 * contains one data element, i.e. the lowest TSN associated with the IP
2569 * datagram marked with the CE bit.....
2570 *
2571 * Verification Tag: 8.5 Verification Tag [Normal verification]
2572 * Inputs
2573 * (endpoint, asoc, chunk)
2574 *
2575 * Outputs
2576 * (asoc, reply_msg, msg_up, timers, counters)
2577 *
2578 * The return value is the disposition of the chunk.
2579 */
2580sctp_disposition_t sctp_sf_do_ecne(const struct sctp_endpoint *ep,
2581 const struct sctp_association *asoc,
2582 const sctp_subtype_t type,
2583 void *arg,
2584 sctp_cmd_seq_t *commands)
2585{
2586 sctp_ecnehdr_t *ecne;
2587 struct sctp_chunk *chunk = arg;
2588
2589 if (!sctp_vtag_verify(chunk, asoc))
2590 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2591
2592 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2593 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2594 commands);
2595
2596 ecne = (sctp_ecnehdr_t *) chunk->skb->data;
2597 skb_pull(chunk->skb, sizeof(sctp_ecnehdr_t));
2598
2599 /* If this is a newer ECNE than the last CWR packet we sent out */
2600 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_ECNE,
2601 SCTP_U32(ntohl(ecne->lowest_tsn)));
2602
2603 return SCTP_DISPOSITION_CONSUME;
2604}
2605
2606/*
2607 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
2608 *
2609 * The SCTP endpoint MUST always acknowledge the reception of each valid
2610 * DATA chunk.
2611 *
2612 * The guidelines on delayed acknowledgement algorithm specified in
2613 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
2614 * acknowledgement SHOULD be generated for at least every second packet
2615 * (not every second DATA chunk) received, and SHOULD be generated within
2616 * 200 ms of the arrival of any unacknowledged DATA chunk. In some
2617 * situations it may be beneficial for an SCTP transmitter to be more
2618 * conservative than the algorithms detailed in this document allow.
2619 * However, an SCTP transmitter MUST NOT be more aggressive than the
2620 * following algorithms allow.
2621 *
2622 * A SCTP receiver MUST NOT generate more than one SACK for every
2623 * incoming packet, other than to update the offered window as the
2624 * receiving application consumes new data.
2625 *
2626 * Verification Tag: 8.5 Verification Tag [Normal verification]
2627 *
2628 * Inputs
2629 * (endpoint, asoc, chunk)
2630 *
2631 * Outputs
2632 * (asoc, reply_msg, msg_up, timers, counters)
2633 *
2634 * The return value is the disposition of the chunk.
2635 */
2636sctp_disposition_t sctp_sf_eat_data_6_2(const struct sctp_endpoint *ep,
2637 const struct sctp_association *asoc,
2638 const sctp_subtype_t type,
2639 void *arg,
2640 sctp_cmd_seq_t *commands)
2641{
2642 struct sctp_chunk *chunk = arg;
2643 int error;
2644
2645 if (!sctp_vtag_verify(chunk, asoc)) {
2646 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
2647 SCTP_NULL());
2648 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2649 }
2650
2651 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
2652 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2653 commands);
2654
2655 error = sctp_eat_data(asoc, chunk, commands );
2656 switch (error) {
2657 case SCTP_IERROR_NO_ERROR:
2658 break;
2659 case SCTP_IERROR_HIGH_TSN:
2660 case SCTP_IERROR_BAD_STREAM:
2661 goto discard_noforce;
2662 case SCTP_IERROR_DUP_TSN:
2663 case SCTP_IERROR_IGNORE_TSN:
2664 goto discard_force;
2665 case SCTP_IERROR_NO_DATA:
2666 goto consume;
2667 default:
2668 BUG();
2669 }
2670
2671 if (asoc->autoclose) {
2672 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2673 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
2674 }
2675
2676 /* If this is the last chunk in a packet, we need to count it
2677 * toward sack generation. Note that we need to SACK every
2678 * OTHER packet containing data chunks, EVEN IF WE DISCARD
2679 * THEM. We elect to NOT generate SACK's if the chunk fails
2680 * the verification tag test.
2681 *
2682 * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2683 *
2684 * The SCTP endpoint MUST always acknowledge the reception of
2685 * each valid DATA chunk.
2686 *
2687 * The guidelines on delayed acknowledgement algorithm
2688 * specified in Section 4.2 of [RFC2581] SHOULD be followed.
2689 * Specifically, an acknowledgement SHOULD be generated for at
2690 * least every second packet (not every second DATA chunk)
2691 * received, and SHOULD be generated within 200 ms of the
2692 * arrival of any unacknowledged DATA chunk. In some
2693 * situations it may be beneficial for an SCTP transmitter to
2694 * be more conservative than the algorithms detailed in this
2695 * document allow. However, an SCTP transmitter MUST NOT be
2696 * more aggressive than the following algorithms allow.
2697 */
Frank Filz52ccb8e2005-12-22 11:36:46 -08002698 if (chunk->end_of_packet)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002699 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
2700
Linus Torvalds1da177e2005-04-16 15:20:36 -07002701 return SCTP_DISPOSITION_CONSUME;
2702
2703discard_force:
2704 /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2705 *
2706 * When a packet arrives with duplicate DATA chunk(s) and with
2707 * no new DATA chunk(s), the endpoint MUST immediately send a
2708 * SACK with no delay. If a packet arrives with duplicate
2709 * DATA chunk(s) bundled with new DATA chunks, the endpoint
2710 * MAY immediately send a SACK. Normally receipt of duplicate
2711 * DATA chunks will occur when the original SACK chunk was lost
2712 * and the peer's RTO has expired. The duplicate TSN number(s)
2713 * SHOULD be reported in the SACK as duplicate.
2714 */
2715 /* In our case, we split the MAY SACK advice up whether or not
2716 * the last chunk is a duplicate.'
2717 */
2718 if (chunk->end_of_packet)
2719 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
2720 return SCTP_DISPOSITION_DISCARD;
2721
2722discard_noforce:
Frank Filz52ccb8e2005-12-22 11:36:46 -08002723 if (chunk->end_of_packet)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002724 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
2725
Linus Torvalds1da177e2005-04-16 15:20:36 -07002726 return SCTP_DISPOSITION_DISCARD;
2727consume:
2728 return SCTP_DISPOSITION_CONSUME;
2729
2730}
2731
2732/*
2733 * sctp_sf_eat_data_fast_4_4
2734 *
2735 * Section: 4 (4)
2736 * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received
2737 * DATA chunks without delay.
2738 *
2739 * Verification Tag: 8.5 Verification Tag [Normal verification]
2740 * Inputs
2741 * (endpoint, asoc, chunk)
2742 *
2743 * Outputs
2744 * (asoc, reply_msg, msg_up, timers, counters)
2745 *
2746 * The return value is the disposition of the chunk.
2747 */
2748sctp_disposition_t sctp_sf_eat_data_fast_4_4(const struct sctp_endpoint *ep,
2749 const struct sctp_association *asoc,
2750 const sctp_subtype_t type,
2751 void *arg,
2752 sctp_cmd_seq_t *commands)
2753{
2754 struct sctp_chunk *chunk = arg;
2755 int error;
2756
2757 if (!sctp_vtag_verify(chunk, asoc)) {
2758 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
2759 SCTP_NULL());
2760 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2761 }
2762
2763 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
2764 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2765 commands);
2766
2767 error = sctp_eat_data(asoc, chunk, commands );
2768 switch (error) {
2769 case SCTP_IERROR_NO_ERROR:
2770 case SCTP_IERROR_HIGH_TSN:
2771 case SCTP_IERROR_DUP_TSN:
2772 case SCTP_IERROR_IGNORE_TSN:
2773 case SCTP_IERROR_BAD_STREAM:
2774 break;
2775 case SCTP_IERROR_NO_DATA:
2776 goto consume;
2777 default:
2778 BUG();
2779 }
2780
2781 /* Go a head and force a SACK, since we are shutting down. */
2782
2783 /* Implementor's Guide.
2784 *
2785 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
2786 * respond to each received packet containing one or more DATA chunk(s)
2787 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
2788 */
2789 if (chunk->end_of_packet) {
2790 /* We must delay the chunk creation since the cumulative
2791 * TSN has not been updated yet.
2792 */
2793 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
2794 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
2795 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2796 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2797 }
2798
2799consume:
2800 return SCTP_DISPOSITION_CONSUME;
2801}
2802
2803/*
2804 * Section: 6.2 Processing a Received SACK
2805 * D) Any time a SACK arrives, the endpoint performs the following:
2806 *
2807 * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point,
2808 * then drop the SACK. Since Cumulative TSN Ack is monotonically
2809 * increasing, a SACK whose Cumulative TSN Ack is less than the
2810 * Cumulative TSN Ack Point indicates an out-of-order SACK.
2811 *
2812 * ii) Set rwnd equal to the newly received a_rwnd minus the number
2813 * of bytes still outstanding after processing the Cumulative TSN Ack
2814 * and the Gap Ack Blocks.
2815 *
2816 * iii) If the SACK is missing a TSN that was previously
2817 * acknowledged via a Gap Ack Block (e.g., the data receiver
2818 * reneged on the data), then mark the corresponding DATA chunk
2819 * as available for retransmit: Mark it as missing for fast
2820 * retransmit as described in Section 7.2.4 and if no retransmit
2821 * timer is running for the destination address to which the DATA
2822 * chunk was originally transmitted, then T3-rtx is started for
2823 * that destination address.
2824 *
2825 * Verification Tag: 8.5 Verification Tag [Normal verification]
2826 *
2827 * Inputs
2828 * (endpoint, asoc, chunk)
2829 *
2830 * Outputs
2831 * (asoc, reply_msg, msg_up, timers, counters)
2832 *
2833 * The return value is the disposition of the chunk.
2834 */
2835sctp_disposition_t sctp_sf_eat_sack_6_2(const struct sctp_endpoint *ep,
2836 const struct sctp_association *asoc,
2837 const sctp_subtype_t type,
2838 void *arg,
2839 sctp_cmd_seq_t *commands)
2840{
2841 struct sctp_chunk *chunk = arg;
2842 sctp_sackhdr_t *sackh;
2843 __u32 ctsn;
2844
2845 if (!sctp_vtag_verify(chunk, asoc))
2846 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2847
2848 /* Make sure that the SACK chunk has a valid length. */
2849 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_sack_chunk_t)))
2850 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2851 commands);
2852
2853 /* Pull the SACK chunk from the data buffer */
2854 sackh = sctp_sm_pull_sack(chunk);
2855 /* Was this a bogus SACK? */
2856 if (!sackh)
2857 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2858 chunk->subh.sack_hdr = sackh;
2859 ctsn = ntohl(sackh->cum_tsn_ack);
2860
2861 /* i) If Cumulative TSN Ack is less than the Cumulative TSN
2862 * Ack Point, then drop the SACK. Since Cumulative TSN
2863 * Ack is monotonically increasing, a SACK whose
2864 * Cumulative TSN Ack is less than the Cumulative TSN Ack
2865 * Point indicates an out-of-order SACK.
2866 */
2867 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
2868 SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn);
2869 SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc->ctsn_ack_point);
2870 return SCTP_DISPOSITION_DISCARD;
2871 }
2872
2873 /* Return this SACK for further processing. */
2874 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_SACKH(sackh));
2875
2876 /* Note: We do the rest of the work on the PROCESS_SACK
2877 * sideeffect.
2878 */
2879 return SCTP_DISPOSITION_CONSUME;
2880}
2881
2882/*
2883 * Generate an ABORT in response to a packet.
2884 *
Jerome Forissier047a2422005-04-28 11:58:43 -07002885 * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41
Linus Torvalds1da177e2005-04-16 15:20:36 -07002886 *
Jerome Forissier047a2422005-04-28 11:58:43 -07002887 * 8) The receiver should respond to the sender of the OOTB packet with
2888 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
2889 * MUST fill in the Verification Tag field of the outbound packet
2890 * with the value found in the Verification Tag field of the OOTB
2891 * packet and set the T-bit in the Chunk Flags to indicate that the
2892 * Verification Tag is reflected. After sending this ABORT, the
2893 * receiver of the OOTB packet shall discard the OOTB packet and take
2894 * no further action.
Linus Torvalds1da177e2005-04-16 15:20:36 -07002895 *
2896 * Verification Tag:
2897 *
2898 * The return value is the disposition of the chunk.
2899*/
2900sctp_disposition_t sctp_sf_tabort_8_4_8(const struct sctp_endpoint *ep,
2901 const struct sctp_association *asoc,
2902 const sctp_subtype_t type,
2903 void *arg,
2904 sctp_cmd_seq_t *commands)
2905{
2906 struct sctp_packet *packet = NULL;
2907 struct sctp_chunk *chunk = arg;
2908 struct sctp_chunk *abort;
2909
2910 packet = sctp_ootb_pkt_new(asoc, chunk);
2911
2912 if (packet) {
2913 /* Make an ABORT. The T bit will be set if the asoc
2914 * is NULL.
2915 */
2916 abort = sctp_make_abort(asoc, chunk, 0);
2917 if (!abort) {
2918 sctp_ootb_pkt_free(packet);
2919 return SCTP_DISPOSITION_NOMEM;
2920 }
2921
Jerome Forissier047a2422005-04-28 11:58:43 -07002922 /* Reflect vtag if T-Bit is set */
2923 if (sctp_test_T_bit(abort))
2924 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
2925
Linus Torvalds1da177e2005-04-16 15:20:36 -07002926 /* Set the skb to the belonging sock for accounting. */
2927 abort->skb->sk = ep->base.sk;
2928
2929 sctp_packet_append_chunk(packet, abort);
2930
2931 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
2932 SCTP_PACKET(packet));
2933
2934 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
2935
2936 return SCTP_DISPOSITION_CONSUME;
2937 }
2938
2939 return SCTP_DISPOSITION_NOMEM;
2940}
2941
2942/*
2943 * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR
2944 * event as ULP notification for each cause included in the chunk.
2945 *
2946 * API 5.3.1.3 - SCTP_REMOTE_ERROR
2947 *
2948 * The return value is the disposition of the chunk.
2949*/
2950sctp_disposition_t sctp_sf_operr_notify(const struct sctp_endpoint *ep,
2951 const struct sctp_association *asoc,
2952 const sctp_subtype_t type,
2953 void *arg,
2954 sctp_cmd_seq_t *commands)
2955{
2956 struct sctp_chunk *chunk = arg;
2957 struct sctp_ulpevent *ev;
2958
2959 if (!sctp_vtag_verify(chunk, asoc))
2960 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2961
2962 /* Make sure that the ERROR chunk has a valid length. */
2963 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
2964 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2965 commands);
2966
2967 while (chunk->chunk_end > chunk->skb->data) {
2968 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
2969 GFP_ATOMIC);
2970 if (!ev)
2971 goto nomem;
2972
2973 if (!sctp_add_cmd(commands, SCTP_CMD_EVENT_ULP,
2974 SCTP_ULPEVENT(ev))) {
2975 sctp_ulpevent_free(ev);
2976 goto nomem;
2977 }
2978
2979 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_OPERR,
2980 SCTP_CHUNK(chunk));
2981 }
2982 return SCTP_DISPOSITION_CONSUME;
2983
2984nomem:
2985 return SCTP_DISPOSITION_NOMEM;
2986}
2987
2988/*
2989 * Process an inbound SHUTDOWN ACK.
2990 *
2991 * From Section 9.2:
2992 * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
2993 * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its
2994 * peer, and remove all record of the association.
2995 *
2996 * The return value is the disposition.
2997 */
2998sctp_disposition_t sctp_sf_do_9_2_final(const struct sctp_endpoint *ep,
2999 const struct sctp_association *asoc,
3000 const sctp_subtype_t type,
3001 void *arg,
3002 sctp_cmd_seq_t *commands)
3003{
3004 struct sctp_chunk *chunk = arg;
3005 struct sctp_chunk *reply;
3006 struct sctp_ulpevent *ev;
3007
3008 if (!sctp_vtag_verify(chunk, asoc))
3009 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3010
3011 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3012 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3013 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3014 commands);
3015
3016 /* 10.2 H) SHUTDOWN COMPLETE notification
3017 *
3018 * When SCTP completes the shutdown procedures (section 9.2) this
3019 * notification is passed to the upper layer.
3020 */
3021 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
3022 0, 0, 0, GFP_ATOMIC);
3023 if (!ev)
3024 goto nomem;
3025
3026 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
3027
3028 /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3029 * stop the T2-shutdown timer,
3030 */
3031 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3032 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3033
3034 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3035 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
3036
3037 /* ...send a SHUTDOWN COMPLETE chunk to its peer, */
3038 reply = sctp_make_shutdown_complete(asoc, chunk);
3039 if (!reply)
3040 goto nomem;
3041
3042 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3043 SCTP_STATE(SCTP_STATE_CLOSED));
3044 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
3045 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3046 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
3047
3048 /* ...and remove all record of the association. */
3049 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
3050 return SCTP_DISPOSITION_DELETE_TCB;
3051
3052nomem:
3053 return SCTP_DISPOSITION_NOMEM;
3054}
3055
3056/*
Jerome Forissier047a2422005-04-28 11:58:43 -07003057 * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41.
3058 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003059 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3060 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3061 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3062 * packet must fill in the Verification Tag field of the outbound
3063 * packet with the Verification Tag received in the SHUTDOWN ACK and
Jerome Forissier047a2422005-04-28 11:58:43 -07003064 * set the T-bit in the Chunk Flags to indicate that the Verification
3065 * Tag is reflected.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003066 *
3067 * 8) The receiver should respond to the sender of the OOTB packet with
3068 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3069 * MUST fill in the Verification Tag field of the outbound packet
3070 * with the value found in the Verification Tag field of the OOTB
Jerome Forissier047a2422005-04-28 11:58:43 -07003071 * packet and set the T-bit in the Chunk Flags to indicate that the
3072 * Verification Tag is reflected. After sending this ABORT, the
3073 * receiver of the OOTB packet shall discard the OOTB packet and take
3074 * no further action.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003075 */
3076sctp_disposition_t sctp_sf_ootb(const struct sctp_endpoint *ep,
3077 const struct sctp_association *asoc,
3078 const sctp_subtype_t type,
3079 void *arg,
3080 sctp_cmd_seq_t *commands)
3081{
3082 struct sctp_chunk *chunk = arg;
3083 struct sk_buff *skb = chunk->skb;
3084 sctp_chunkhdr_t *ch;
3085 __u8 *ch_end;
3086 int ootb_shut_ack = 0;
3087
3088 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES);
3089
3090 ch = (sctp_chunkhdr_t *) chunk->chunk_hdr;
3091 do {
3092 /* Break out if chunk length is less then minimal. */
3093 if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t))
3094 break;
3095
3096 ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
Tsutomu Fujiia7d1f1b2006-01-17 11:57:09 -08003097 if (ch_end > skb->tail)
3098 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003099
3100 if (SCTP_CID_SHUTDOWN_ACK == ch->type)
3101 ootb_shut_ack = 1;
3102
3103 /* RFC 2960, Section 3.3.7
3104 * Moreover, under any circumstances, an endpoint that
3105 * receives an ABORT MUST NOT respond to that ABORT by
3106 * sending an ABORT of its own.
3107 */
3108 if (SCTP_CID_ABORT == ch->type)
3109 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3110
3111 ch = (sctp_chunkhdr_t *) ch_end;
3112 } while (ch_end < skb->tail);
3113
3114 if (ootb_shut_ack)
3115 sctp_sf_shut_8_4_5(ep, asoc, type, arg, commands);
3116 else
3117 sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
3118
3119 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3120}
3121
3122/*
3123 * Handle an "Out of the blue" SHUTDOWN ACK.
3124 *
Jerome Forissier047a2422005-04-28 11:58:43 -07003125 * Section: 8.4 5, sctpimpguide 2.41.
3126 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07003127 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
Jerome Forissier047a2422005-04-28 11:58:43 -07003128 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3129 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3130 * packet must fill in the Verification Tag field of the outbound
3131 * packet with the Verification Tag received in the SHUTDOWN ACK and
3132 * set the T-bit in the Chunk Flags to indicate that the Verification
3133 * Tag is reflected.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003134 *
3135 * Inputs
3136 * (endpoint, asoc, type, arg, commands)
3137 *
3138 * Outputs
3139 * (sctp_disposition_t)
3140 *
3141 * The return value is the disposition of the chunk.
3142 */
3143static sctp_disposition_t sctp_sf_shut_8_4_5(const struct sctp_endpoint *ep,
3144 const struct sctp_association *asoc,
3145 const sctp_subtype_t type,
3146 void *arg,
3147 sctp_cmd_seq_t *commands)
3148{
3149 struct sctp_packet *packet = NULL;
3150 struct sctp_chunk *chunk = arg;
3151 struct sctp_chunk *shut;
3152
3153 packet = sctp_ootb_pkt_new(asoc, chunk);
3154
3155 if (packet) {
3156 /* Make an SHUTDOWN_COMPLETE.
3157 * The T bit will be set if the asoc is NULL.
3158 */
3159 shut = sctp_make_shutdown_complete(asoc, chunk);
3160 if (!shut) {
3161 sctp_ootb_pkt_free(packet);
3162 return SCTP_DISPOSITION_NOMEM;
3163 }
3164
Jerome Forissier047a2422005-04-28 11:58:43 -07003165 /* Reflect vtag if T-Bit is set */
3166 if (sctp_test_T_bit(shut))
3167 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3168
Linus Torvalds1da177e2005-04-16 15:20:36 -07003169 /* Set the skb to the belonging sock for accounting. */
3170 shut->skb->sk = ep->base.sk;
3171
3172 sctp_packet_append_chunk(packet, shut);
3173
3174 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3175 SCTP_PACKET(packet));
3176
3177 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
3178
3179 /* If the chunk length is invalid, we don't want to process
3180 * the reset of the packet.
3181 */
3182 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3183 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3184
3185 return SCTP_DISPOSITION_CONSUME;
3186 }
3187
3188 return SCTP_DISPOSITION_NOMEM;
3189}
3190
3191/*
3192 * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state.
3193 *
3194 * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK
3195 * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the
3196 * procedures in section 8.4 SHOULD be followed, in other words it
3197 * should be treated as an Out Of The Blue packet.
3198 * [This means that we do NOT check the Verification Tag on these
3199 * chunks. --piggy ]
3200 *
3201 */
3202sctp_disposition_t sctp_sf_do_8_5_1_E_sa(const struct sctp_endpoint *ep,
3203 const struct sctp_association *asoc,
3204 const sctp_subtype_t type,
3205 void *arg,
3206 sctp_cmd_seq_t *commands)
3207{
3208 /* Although we do have an association in this case, it corresponds
3209 * to a restarted association. So the packet is treated as an OOTB
3210 * packet and the state function that handles OOTB SHUTDOWN_ACK is
3211 * called with a NULL association.
3212 */
3213 return sctp_sf_shut_8_4_5(ep, NULL, type, arg, commands);
3214}
3215
3216/* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */
3217sctp_disposition_t sctp_sf_do_asconf(const struct sctp_endpoint *ep,
3218 const struct sctp_association *asoc,
3219 const sctp_subtype_t type, void *arg,
3220 sctp_cmd_seq_t *commands)
3221{
3222 struct sctp_chunk *chunk = arg;
3223 struct sctp_chunk *asconf_ack = NULL;
3224 sctp_addiphdr_t *hdr;
3225 __u32 serial;
3226
3227 if (!sctp_vtag_verify(chunk, asoc)) {
3228 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3229 SCTP_NULL());
3230 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3231 }
3232
3233 /* Make sure that the ASCONF ADDIP chunk has a valid length. */
3234 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_addip_chunk_t)))
3235 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3236 commands);
3237
3238 hdr = (sctp_addiphdr_t *)chunk->skb->data;
3239 serial = ntohl(hdr->serial);
3240
3241 /* ADDIP 4.2 C1) Compare the value of the serial number to the value
3242 * the endpoint stored in a new association variable
3243 * 'Peer-Serial-Number'.
3244 */
3245 if (serial == asoc->peer.addip_serial + 1) {
3246 /* ADDIP 4.2 C2) If the value found in the serial number is
3247 * equal to the ('Peer-Serial-Number' + 1), the endpoint MUST
3248 * do V1-V5.
3249 */
3250 asconf_ack = sctp_process_asconf((struct sctp_association *)
3251 asoc, chunk);
3252 if (!asconf_ack)
3253 return SCTP_DISPOSITION_NOMEM;
3254 } else if (serial == asoc->peer.addip_serial) {
3255 /* ADDIP 4.2 C3) If the value found in the serial number is
3256 * equal to the value stored in the 'Peer-Serial-Number'
3257 * IMPLEMENTATION NOTE: As an optimization a receiver may wish
3258 * to save the last ASCONF-ACK for some predetermined period of
3259 * time and instead of re-processing the ASCONF (with the same
3260 * serial number) it may just re-transmit the ASCONF-ACK.
3261 */
3262 if (asoc->addip_last_asconf_ack)
3263 asconf_ack = asoc->addip_last_asconf_ack;
3264 else
3265 return SCTP_DISPOSITION_DISCARD;
3266 } else {
3267 /* ADDIP 4.2 C4) Otherwise, the ASCONF Chunk is discarded since
3268 * it must be either a stale packet or from an attacker.
3269 */
3270 return SCTP_DISPOSITION_DISCARD;
3271 }
3272
3273 /* ADDIP 4.2 C5) In both cases C2 and C3 the ASCONF-ACK MUST be sent
3274 * back to the source address contained in the IP header of the ASCONF
3275 * being responded to.
3276 */
3277 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(asconf_ack));
3278
3279 return SCTP_DISPOSITION_CONSUME;
3280}
3281
3282/*
3283 * ADDIP Section 4.3 General rules for address manipulation
3284 * When building TLV parameters for the ASCONF Chunk that will add or
3285 * delete IP addresses the D0 to D13 rules should be applied:
3286 */
3287sctp_disposition_t sctp_sf_do_asconf_ack(const struct sctp_endpoint *ep,
3288 const struct sctp_association *asoc,
3289 const sctp_subtype_t type, void *arg,
3290 sctp_cmd_seq_t *commands)
3291{
3292 struct sctp_chunk *asconf_ack = arg;
3293 struct sctp_chunk *last_asconf = asoc->addip_last_asconf;
3294 struct sctp_chunk *abort;
3295 sctp_addiphdr_t *addip_hdr;
3296 __u32 sent_serial, rcvd_serial;
3297
3298 if (!sctp_vtag_verify(asconf_ack, asoc)) {
3299 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3300 SCTP_NULL());
3301 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3302 }
3303
3304 /* Make sure that the ADDIP chunk has a valid length. */
3305 if (!sctp_chunk_length_valid(asconf_ack, sizeof(sctp_addip_chunk_t)))
3306 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3307 commands);
3308
3309 addip_hdr = (sctp_addiphdr_t *)asconf_ack->skb->data;
3310 rcvd_serial = ntohl(addip_hdr->serial);
3311
3312 if (last_asconf) {
3313 addip_hdr = (sctp_addiphdr_t *)last_asconf->subh.addip_hdr;
3314 sent_serial = ntohl(addip_hdr->serial);
3315 } else {
3316 sent_serial = asoc->addip_serial - 1;
3317 }
3318
3319 /* D0) If an endpoint receives an ASCONF-ACK that is greater than or
3320 * equal to the next serial number to be used but no ASCONF chunk is
3321 * outstanding the endpoint MUST ABORT the association. Note that a
3322 * sequence number is greater than if it is no more than 2^^31-1
3323 * larger than the current sequence number (using serial arithmetic).
3324 */
3325 if (ADDIP_SERIAL_gte(rcvd_serial, sent_serial + 1) &&
3326 !(asoc->addip_last_asconf)) {
3327 abort = sctp_make_abort(asoc, asconf_ack,
3328 sizeof(sctp_errhdr_t));
3329 if (abort) {
3330 sctp_init_cause(abort, SCTP_ERROR_ASCONF_ACK, NULL, 0);
3331 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3332 SCTP_CHUNK(abort));
3333 }
3334 /* We are going to ABORT, so we might as well stop
3335 * processing the rest of the chunks in the packet.
3336 */
3337 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3338 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3339 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07003340 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
3341 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003342 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
3343 SCTP_U32(SCTP_ERROR_ASCONF_ACK));
3344 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
3345 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3346 return SCTP_DISPOSITION_ABORT;
3347 }
3348
3349 if ((rcvd_serial == sent_serial) && asoc->addip_last_asconf) {
3350 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3351 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3352
3353 if (!sctp_process_asconf_ack((struct sctp_association *)asoc,
3354 asconf_ack))
3355 return SCTP_DISPOSITION_CONSUME;
3356
3357 abort = sctp_make_abort(asoc, asconf_ack,
3358 sizeof(sctp_errhdr_t));
3359 if (abort) {
3360 sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, NULL, 0);
3361 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3362 SCTP_CHUNK(abort));
3363 }
3364 /* We are going to ABORT, so we might as well stop
3365 * processing the rest of the chunks in the packet.
3366 */
3367 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07003368 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
3369 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003370 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
3371 SCTP_U32(SCTP_ERROR_ASCONF_ACK));
3372 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
3373 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3374 return SCTP_DISPOSITION_ABORT;
3375 }
3376
3377 return SCTP_DISPOSITION_DISCARD;
3378}
3379
3380/*
3381 * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP
3382 *
3383 * When a FORWARD TSN chunk arrives, the data receiver MUST first update
3384 * its cumulative TSN point to the value carried in the FORWARD TSN
3385 * chunk, and then MUST further advance its cumulative TSN point locally
3386 * if possible.
3387 * After the above processing, the data receiver MUST stop reporting any
3388 * missing TSNs earlier than or equal to the new cumulative TSN point.
3389 *
3390 * Verification Tag: 8.5 Verification Tag [Normal verification]
3391 *
3392 * The return value is the disposition of the chunk.
3393 */
3394sctp_disposition_t sctp_sf_eat_fwd_tsn(const struct sctp_endpoint *ep,
3395 const struct sctp_association *asoc,
3396 const sctp_subtype_t type,
3397 void *arg,
3398 sctp_cmd_seq_t *commands)
3399{
3400 struct sctp_chunk *chunk = arg;
3401 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
3402 __u16 len;
3403 __u32 tsn;
3404
3405 if (!sctp_vtag_verify(chunk, asoc)) {
3406 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3407 SCTP_NULL());
3408 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3409 }
3410
3411 /* Make sure that the FORWARD_TSN chunk has valid length. */
3412 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
3413 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3414 commands);
3415
3416 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3417 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3418 len = ntohs(chunk->chunk_hdr->length);
3419 len -= sizeof(struct sctp_chunkhdr);
3420 skb_pull(chunk->skb, len);
3421
3422 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
3423 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __FUNCTION__, tsn);
3424
3425 /* The TSN is too high--silently discard the chunk and count on it
3426 * getting retransmitted later.
3427 */
3428 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3429 goto discard_noforce;
3430
3431 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3432 if (len > sizeof(struct sctp_fwdtsn_hdr))
3433 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
3434 SCTP_CHUNK(chunk));
3435
3436 /* Count this as receiving DATA. */
3437 if (asoc->autoclose) {
3438 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3439 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
3440 }
3441
3442 /* FIXME: For now send a SACK, but DATA processing may
3443 * send another.
3444 */
3445 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
Linus Torvalds1da177e2005-04-16 15:20:36 -07003446
3447 return SCTP_DISPOSITION_CONSUME;
3448
3449discard_noforce:
3450 return SCTP_DISPOSITION_DISCARD;
3451}
3452
3453sctp_disposition_t sctp_sf_eat_fwd_tsn_fast(
3454 const struct sctp_endpoint *ep,
3455 const struct sctp_association *asoc,
3456 const sctp_subtype_t type,
3457 void *arg,
3458 sctp_cmd_seq_t *commands)
3459{
3460 struct sctp_chunk *chunk = arg;
3461 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
3462 __u16 len;
3463 __u32 tsn;
3464
3465 if (!sctp_vtag_verify(chunk, asoc)) {
3466 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3467 SCTP_NULL());
3468 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3469 }
3470
3471 /* Make sure that the FORWARD_TSN chunk has a valid length. */
3472 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
3473 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3474 commands);
3475
3476 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3477 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3478 len = ntohs(chunk->chunk_hdr->length);
3479 len -= sizeof(struct sctp_chunkhdr);
3480 skb_pull(chunk->skb, len);
3481
3482 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
3483 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __FUNCTION__, tsn);
3484
3485 /* The TSN is too high--silently discard the chunk and count on it
3486 * getting retransmitted later.
3487 */
3488 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3489 goto gen_shutdown;
3490
3491 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3492 if (len > sizeof(struct sctp_fwdtsn_hdr))
3493 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
3494 SCTP_CHUNK(chunk));
3495
3496 /* Go a head and force a SACK, since we are shutting down. */
3497gen_shutdown:
3498 /* Implementor's Guide.
3499 *
3500 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3501 * respond to each received packet containing one or more DATA chunk(s)
3502 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3503 */
3504 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
3505 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3506 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3507 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3508
3509 return SCTP_DISPOSITION_CONSUME;
3510}
3511
3512/*
3513 * Process an unknown chunk.
3514 *
3515 * Section: 3.2. Also, 2.1 in the implementor's guide.
3516 *
3517 * Chunk Types are encoded such that the highest-order two bits specify
3518 * the action that must be taken if the processing endpoint does not
3519 * recognize the Chunk Type.
3520 *
3521 * 00 - Stop processing this SCTP packet and discard it, do not process
3522 * any further chunks within it.
3523 *
3524 * 01 - Stop processing this SCTP packet and discard it, do not process
3525 * any further chunks within it, and report the unrecognized
3526 * chunk in an 'Unrecognized Chunk Type'.
3527 *
3528 * 10 - Skip this chunk and continue processing.
3529 *
3530 * 11 - Skip this chunk and continue processing, but report in an ERROR
3531 * Chunk using the 'Unrecognized Chunk Type' cause of error.
3532 *
3533 * The return value is the disposition of the chunk.
3534 */
3535sctp_disposition_t sctp_sf_unk_chunk(const struct sctp_endpoint *ep,
3536 const struct sctp_association *asoc,
3537 const sctp_subtype_t type,
3538 void *arg,
3539 sctp_cmd_seq_t *commands)
3540{
3541 struct sctp_chunk *unk_chunk = arg;
3542 struct sctp_chunk *err_chunk;
3543 sctp_chunkhdr_t *hdr;
3544
3545 SCTP_DEBUG_PRINTK("Processing the unknown chunk id %d.\n", type.chunk);
3546
3547 if (!sctp_vtag_verify(unk_chunk, asoc))
3548 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3549
3550 /* Make sure that the chunk has a valid length.
3551 * Since we don't know the chunk type, we use a general
3552 * chunkhdr structure to make a comparison.
3553 */
3554 if (!sctp_chunk_length_valid(unk_chunk, sizeof(sctp_chunkhdr_t)))
3555 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3556 commands);
3557
3558 switch (type.chunk & SCTP_CID_ACTION_MASK) {
3559 case SCTP_CID_ACTION_DISCARD:
3560 /* Discard the packet. */
3561 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3562 break;
3563 case SCTP_CID_ACTION_DISCARD_ERR:
3564 /* Discard the packet. */
3565 sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3566
3567 /* Generate an ERROR chunk as response. */
3568 hdr = unk_chunk->chunk_hdr;
3569 err_chunk = sctp_make_op_error(asoc, unk_chunk,
3570 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
3571 WORD_ROUND(ntohs(hdr->length)));
3572 if (err_chunk) {
3573 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3574 SCTP_CHUNK(err_chunk));
3575 }
3576 return SCTP_DISPOSITION_CONSUME;
3577 break;
3578 case SCTP_CID_ACTION_SKIP:
3579 /* Skip the chunk. */
3580 return SCTP_DISPOSITION_DISCARD;
3581 break;
3582 case SCTP_CID_ACTION_SKIP_ERR:
3583 /* Generate an ERROR chunk as response. */
3584 hdr = unk_chunk->chunk_hdr;
3585 err_chunk = sctp_make_op_error(asoc, unk_chunk,
3586 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
3587 WORD_ROUND(ntohs(hdr->length)));
3588 if (err_chunk) {
3589 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3590 SCTP_CHUNK(err_chunk));
3591 }
3592 /* Skip the chunk. */
3593 return SCTP_DISPOSITION_CONSUME;
3594 break;
3595 default:
3596 break;
3597 }
3598
3599 return SCTP_DISPOSITION_DISCARD;
3600}
3601
3602/*
3603 * Discard the chunk.
3604 *
3605 * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2
3606 * [Too numerous to mention...]
3607 * Verification Tag: No verification needed.
3608 * Inputs
3609 * (endpoint, asoc, chunk)
3610 *
3611 * Outputs
3612 * (asoc, reply_msg, msg_up, timers, counters)
3613 *
3614 * The return value is the disposition of the chunk.
3615 */
3616sctp_disposition_t sctp_sf_discard_chunk(const struct sctp_endpoint *ep,
3617 const struct sctp_association *asoc,
3618 const sctp_subtype_t type,
3619 void *arg,
3620 sctp_cmd_seq_t *commands)
3621{
3622 SCTP_DEBUG_PRINTK("Chunk %d is discarded\n", type.chunk);
3623 return SCTP_DISPOSITION_DISCARD;
3624}
3625
3626/*
3627 * Discard the whole packet.
3628 *
3629 * Section: 8.4 2)
3630 *
3631 * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST
3632 * silently discard the OOTB packet and take no further action.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003633 *
3634 * Verification Tag: No verification necessary
3635 *
3636 * Inputs
3637 * (endpoint, asoc, chunk)
3638 *
3639 * Outputs
3640 * (asoc, reply_msg, msg_up, timers, counters)
3641 *
3642 * The return value is the disposition of the chunk.
3643 */
3644sctp_disposition_t sctp_sf_pdiscard(const struct sctp_endpoint *ep,
3645 const struct sctp_association *asoc,
3646 const sctp_subtype_t type,
3647 void *arg,
3648 sctp_cmd_seq_t *commands)
3649{
3650 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
3651
3652 return SCTP_DISPOSITION_CONSUME;
3653}
3654
3655
3656/*
3657 * The other end is violating protocol.
3658 *
3659 * Section: Not specified
3660 * Verification Tag: Not specified
3661 * Inputs
3662 * (endpoint, asoc, chunk)
3663 *
3664 * Outputs
3665 * (asoc, reply_msg, msg_up, timers, counters)
3666 *
3667 * We simply tag the chunk as a violation. The state machine will log
3668 * the violation and continue.
3669 */
3670sctp_disposition_t sctp_sf_violation(const struct sctp_endpoint *ep,
3671 const struct sctp_association *asoc,
3672 const sctp_subtype_t type,
3673 void *arg,
3674 sctp_cmd_seq_t *commands)
3675{
3676 return SCTP_DISPOSITION_VIOLATION;
3677}
3678
3679
3680/*
3681 * Handle a protocol violation when the chunk length is invalid.
3682 * "Invalid" length is identified as smaller then the minimal length a
3683 * given chunk can be. For example, a SACK chunk has invalid length
3684 * if it's length is set to be smaller then the size of sctp_sack_chunk_t.
3685 *
3686 * We inform the other end by sending an ABORT with a Protocol Violation
3687 * error code.
3688 *
3689 * Section: Not specified
3690 * Verification Tag: Nothing to do
3691 * Inputs
3692 * (endpoint, asoc, chunk)
3693 *
3694 * Outputs
3695 * (reply_msg, msg_up, counters)
3696 *
3697 * Generate an ABORT chunk and terminate the association.
3698 */
Adrian Bunk52c1da32005-06-23 22:05:33 -07003699static sctp_disposition_t sctp_sf_violation_chunklen(
3700 const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003701 const struct sctp_association *asoc,
3702 const sctp_subtype_t type,
3703 void *arg,
3704 sctp_cmd_seq_t *commands)
3705{
3706 struct sctp_chunk *chunk = arg;
3707 struct sctp_chunk *abort = NULL;
3708 char err_str[]="The following chunk had invalid length:";
3709
3710 /* Make the abort chunk. */
3711 abort = sctp_make_abort_violation(asoc, chunk, err_str,
3712 sizeof(err_str));
3713 if (!abort)
3714 goto nomem;
3715
3716 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
3717 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
3718
3719 if (asoc->state <= SCTP_STATE_COOKIE_ECHOED) {
3720 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3721 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07003722 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
3723 SCTP_ERROR(ECONNREFUSED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003724 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
3725 SCTP_U32(SCTP_ERROR_PROTO_VIOLATION));
3726 } else {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07003727 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
3728 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07003729 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
3730 SCTP_U32(SCTP_ERROR_PROTO_VIOLATION));
3731 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3732 }
3733
3734 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
3735
3736 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
3737
3738 return SCTP_DISPOSITION_ABORT;
3739
3740nomem:
3741 return SCTP_DISPOSITION_NOMEM;
3742}
3743
3744/***************************************************************************
3745 * These are the state functions for handling primitive (Section 10) events.
3746 ***************************************************************************/
3747/*
3748 * sctp_sf_do_prm_asoc
3749 *
3750 * Section: 10.1 ULP-to-SCTP
3751 * B) Associate
3752 *
3753 * Format: ASSOCIATE(local SCTP instance name, destination transport addr,
3754 * outbound stream count)
3755 * -> association id [,destination transport addr list] [,outbound stream
3756 * count]
3757 *
3758 * This primitive allows the upper layer to initiate an association to a
3759 * specific peer endpoint.
3760 *
3761 * The peer endpoint shall be specified by one of the transport addresses
3762 * which defines the endpoint (see Section 1.4). If the local SCTP
3763 * instance has not been initialized, the ASSOCIATE is considered an
3764 * error.
3765 * [This is not relevant for the kernel implementation since we do all
3766 * initialization at boot time. It we hadn't initialized we wouldn't
3767 * get anywhere near this code.]
3768 *
3769 * An association id, which is a local handle to the SCTP association,
3770 * will be returned on successful establishment of the association. If
3771 * SCTP is not able to open an SCTP association with the peer endpoint,
3772 * an error is returned.
3773 * [In the kernel implementation, the struct sctp_association needs to
3774 * be created BEFORE causing this primitive to run.]
3775 *
3776 * Other association parameters may be returned, including the
3777 * complete destination transport addresses of the peer as well as the
3778 * outbound stream count of the local endpoint. One of the transport
3779 * address from the returned destination addresses will be selected by
3780 * the local endpoint as default primary path for sending SCTP packets
3781 * to this peer. The returned "destination transport addr list" can
3782 * be used by the ULP to change the default primary path or to force
3783 * sending a packet to a specific transport address. [All of this
3784 * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING
3785 * function.]
3786 *
3787 * Mandatory attributes:
3788 *
3789 * o local SCTP instance name - obtained from the INITIALIZE operation.
3790 * [This is the argument asoc.]
3791 * o destination transport addr - specified as one of the transport
3792 * addresses of the peer endpoint with which the association is to be
3793 * established.
3794 * [This is asoc->peer.active_path.]
3795 * o outbound stream count - the number of outbound streams the ULP
3796 * would like to open towards this peer endpoint.
3797 * [BUG: This is not currently implemented.]
3798 * Optional attributes:
3799 *
3800 * None.
3801 *
3802 * The return value is a disposition.
3803 */
3804sctp_disposition_t sctp_sf_do_prm_asoc(const struct sctp_endpoint *ep,
3805 const struct sctp_association *asoc,
3806 const sctp_subtype_t type,
3807 void *arg,
3808 sctp_cmd_seq_t *commands)
3809{
3810 struct sctp_chunk *repl;
3811
3812 /* The comment below says that we enter COOKIE-WAIT AFTER
3813 * sending the INIT, but that doesn't actually work in our
3814 * implementation...
3815 */
3816 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3817 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
3818
3819 /* RFC 2960 5.1 Normal Establishment of an Association
3820 *
3821 * A) "A" first sends an INIT chunk to "Z". In the INIT, "A"
3822 * must provide its Verification Tag (Tag_A) in the Initiate
3823 * Tag field. Tag_A SHOULD be a random number in the range of
3824 * 1 to 4294967295 (see 5.3.1 for Tag value selection). ...
3825 */
3826
3827 repl = sctp_make_init(asoc, &asoc->base.bind_addr, GFP_ATOMIC, 0);
3828 if (!repl)
3829 goto nomem;
3830
3831 /* Cast away the const modifier, as we want to just
3832 * rerun it through as a sideffect.
3833 */
3834 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC,
3835 SCTP_ASOC((struct sctp_association *) asoc));
3836
Frank Filz3f7a87d2005-06-20 13:14:57 -07003837 /* Choose transport for INIT. */
3838 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
3839 SCTP_CHUNK(repl));
3840
Linus Torvalds1da177e2005-04-16 15:20:36 -07003841 /* After sending the INIT, "A" starts the T1-init timer and
3842 * enters the COOKIE-WAIT state.
3843 */
3844 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
3845 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
3846 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
3847 return SCTP_DISPOSITION_CONSUME;
3848
3849nomem:
3850 return SCTP_DISPOSITION_NOMEM;
3851}
3852
3853/*
3854 * Process the SEND primitive.
3855 *
3856 * Section: 10.1 ULP-to-SCTP
3857 * E) Send
3858 *
3859 * Format: SEND(association id, buffer address, byte count [,context]
3860 * [,stream id] [,life time] [,destination transport address]
3861 * [,unorder flag] [,no-bundle flag] [,payload protocol-id] )
3862 * -> result
3863 *
3864 * This is the main method to send user data via SCTP.
3865 *
3866 * Mandatory attributes:
3867 *
3868 * o association id - local handle to the SCTP association
3869 *
3870 * o buffer address - the location where the user message to be
3871 * transmitted is stored;
3872 *
3873 * o byte count - The size of the user data in number of bytes;
3874 *
3875 * Optional attributes:
3876 *
3877 * o context - an optional 32 bit integer that will be carried in the
3878 * sending failure notification to the ULP if the transportation of
3879 * this User Message fails.
3880 *
3881 * o stream id - to indicate which stream to send the data on. If not
3882 * specified, stream 0 will be used.
3883 *
3884 * o life time - specifies the life time of the user data. The user data
3885 * will not be sent by SCTP after the life time expires. This
3886 * parameter can be used to avoid efforts to transmit stale
3887 * user messages. SCTP notifies the ULP if the data cannot be
3888 * initiated to transport (i.e. sent to the destination via SCTP's
3889 * send primitive) within the life time variable. However, the
3890 * user data will be transmitted if SCTP has attempted to transmit a
3891 * chunk before the life time expired.
3892 *
3893 * o destination transport address - specified as one of the destination
3894 * transport addresses of the peer endpoint to which this packet
3895 * should be sent. Whenever possible, SCTP should use this destination
3896 * transport address for sending the packets, instead of the current
3897 * primary path.
3898 *
3899 * o unorder flag - this flag, if present, indicates that the user
3900 * would like the data delivered in an unordered fashion to the peer
3901 * (i.e., the U flag is set to 1 on all DATA chunks carrying this
3902 * message).
3903 *
3904 * o no-bundle flag - instructs SCTP not to bundle this user data with
3905 * other outbound DATA chunks. SCTP MAY still bundle even when
3906 * this flag is present, when faced with network congestion.
3907 *
3908 * o payload protocol-id - A 32 bit unsigned integer that is to be
3909 * passed to the peer indicating the type of payload protocol data
3910 * being transmitted. This value is passed as opaque data by SCTP.
3911 *
3912 * The return value is the disposition.
3913 */
3914sctp_disposition_t sctp_sf_do_prm_send(const struct sctp_endpoint *ep,
3915 const struct sctp_association *asoc,
3916 const sctp_subtype_t type,
3917 void *arg,
3918 sctp_cmd_seq_t *commands)
3919{
3920 struct sctp_chunk *chunk = arg;
3921
3922 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
3923 return SCTP_DISPOSITION_CONSUME;
3924}
3925
3926/*
3927 * Process the SHUTDOWN primitive.
3928 *
3929 * Section: 10.1:
3930 * C) Shutdown
3931 *
3932 * Format: SHUTDOWN(association id)
3933 * -> result
3934 *
3935 * Gracefully closes an association. Any locally queued user data
3936 * will be delivered to the peer. The association will be terminated only
3937 * after the peer acknowledges all the SCTP packets sent. A success code
3938 * will be returned on successful termination of the association. If
3939 * attempting to terminate the association results in a failure, an error
3940 * code shall be returned.
3941 *
3942 * Mandatory attributes:
3943 *
3944 * o association id - local handle to the SCTP association
3945 *
3946 * Optional attributes:
3947 *
3948 * None.
3949 *
3950 * The return value is the disposition.
3951 */
3952sctp_disposition_t sctp_sf_do_9_2_prm_shutdown(
3953 const struct sctp_endpoint *ep,
3954 const struct sctp_association *asoc,
3955 const sctp_subtype_t type,
3956 void *arg,
3957 sctp_cmd_seq_t *commands)
3958{
3959 int disposition;
3960
3961 /* From 9.2 Shutdown of an Association
3962 * Upon receipt of the SHUTDOWN primitive from its upper
3963 * layer, the endpoint enters SHUTDOWN-PENDING state and
3964 * remains there until all outstanding data has been
3965 * acknowledged by its peer. The endpoint accepts no new data
3966 * from its upper layer, but retransmits data to the far end
3967 * if necessary to fill gaps.
3968 */
3969 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3970 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
3971
3972 /* sctpimpguide-05 Section 2.12.2
3973 * The sender of the SHUTDOWN MAY also start an overall guard timer
3974 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
3975 */
3976 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
3977 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
3978
3979 disposition = SCTP_DISPOSITION_CONSUME;
3980 if (sctp_outq_is_empty(&asoc->outqueue)) {
3981 disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type,
3982 arg, commands);
3983 }
3984 return disposition;
3985}
3986
3987/*
3988 * Process the ABORT primitive.
3989 *
3990 * Section: 10.1:
3991 * C) Abort
3992 *
3993 * Format: Abort(association id [, cause code])
3994 * -> result
3995 *
3996 * Ungracefully closes an association. Any locally queued user data
3997 * will be discarded and an ABORT chunk is sent to the peer. A success code
3998 * will be returned on successful abortion of the association. If
3999 * attempting to abort the association results in a failure, an error
4000 * code shall be returned.
4001 *
4002 * Mandatory attributes:
4003 *
4004 * o association id - local handle to the SCTP association
4005 *
4006 * Optional attributes:
4007 *
4008 * o cause code - reason of the abort to be passed to the peer
4009 *
4010 * None.
4011 *
4012 * The return value is the disposition.
4013 */
4014sctp_disposition_t sctp_sf_do_9_1_prm_abort(
4015 const struct sctp_endpoint *ep,
4016 const struct sctp_association *asoc,
4017 const sctp_subtype_t type,
4018 void *arg,
4019 sctp_cmd_seq_t *commands)
4020{
4021 /* From 9.1 Abort of an Association
4022 * Upon receipt of the ABORT primitive from its upper
4023 * layer, the endpoint enters CLOSED state and
4024 * discard all outstanding data has been
4025 * acknowledged by its peer. The endpoint accepts no new data
4026 * from its upper layer, but retransmits data to the far end
4027 * if necessary to fill gaps.
4028 */
4029 struct msghdr *msg = arg;
4030 struct sctp_chunk *abort;
4031 sctp_disposition_t retval;
4032
4033 retval = SCTP_DISPOSITION_CONSUME;
4034
4035 /* Generate ABORT chunk to send the peer. */
4036 abort = sctp_make_abort_user(asoc, NULL, msg);
4037 if (!abort)
4038 retval = SCTP_DISPOSITION_NOMEM;
4039 else
4040 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4041
4042 /* Even if we can't send the ABORT due to low memory delete the
4043 * TCB. This is a departure from our typical NOMEM handling.
4044 */
4045
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004046 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4047 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004048 /* Delete the established association. */
4049 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4050 SCTP_U32(SCTP_ERROR_USER_ABORT));
4051
4052 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4053 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
4054
4055 return retval;
4056}
4057
4058/* We tried an illegal operation on an association which is closed. */
4059sctp_disposition_t sctp_sf_error_closed(const struct sctp_endpoint *ep,
4060 const struct sctp_association *asoc,
4061 const sctp_subtype_t type,
4062 void *arg,
4063 sctp_cmd_seq_t *commands)
4064{
4065 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, SCTP_ERROR(-EINVAL));
4066 return SCTP_DISPOSITION_CONSUME;
4067}
4068
4069/* We tried an illegal operation on an association which is shutting
4070 * down.
4071 */
4072sctp_disposition_t sctp_sf_error_shutdown(const struct sctp_endpoint *ep,
4073 const struct sctp_association *asoc,
4074 const sctp_subtype_t type,
4075 void *arg,
4076 sctp_cmd_seq_t *commands)
4077{
4078 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR,
4079 SCTP_ERROR(-ESHUTDOWN));
4080 return SCTP_DISPOSITION_CONSUME;
4081}
4082
4083/*
4084 * sctp_cookie_wait_prm_shutdown
4085 *
4086 * Section: 4 Note: 2
4087 * Verification Tag:
4088 * Inputs
4089 * (endpoint, asoc)
4090 *
4091 * The RFC does not explicitly address this issue, but is the route through the
4092 * state table when someone issues a shutdown while in COOKIE_WAIT state.
4093 *
4094 * Outputs
4095 * (timers)
4096 */
4097sctp_disposition_t sctp_sf_cookie_wait_prm_shutdown(
4098 const struct sctp_endpoint *ep,
4099 const struct sctp_association *asoc,
4100 const sctp_subtype_t type,
4101 void *arg,
4102 sctp_cmd_seq_t *commands)
4103{
4104 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4105 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4106
4107 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4108 SCTP_STATE(SCTP_STATE_CLOSED));
4109
4110 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
4111
4112 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
4113
4114 return SCTP_DISPOSITION_DELETE_TCB;
4115}
4116
4117/*
4118 * sctp_cookie_echoed_prm_shutdown
4119 *
4120 * Section: 4 Note: 2
4121 * Verification Tag:
4122 * Inputs
4123 * (endpoint, asoc)
4124 *
4125 * The RFC does not explcitly address this issue, but is the route through the
4126 * state table when someone issues a shutdown while in COOKIE_ECHOED state.
4127 *
4128 * Outputs
4129 * (timers)
4130 */
4131sctp_disposition_t sctp_sf_cookie_echoed_prm_shutdown(
4132 const struct sctp_endpoint *ep,
4133 const struct sctp_association *asoc,
4134 const sctp_subtype_t type,
4135 void *arg, sctp_cmd_seq_t *commands)
4136{
4137 /* There is a single T1 timer, so we should be able to use
4138 * common function with the COOKIE-WAIT state.
4139 */
4140 return sctp_sf_cookie_wait_prm_shutdown(ep, asoc, type, arg, commands);
4141}
4142
4143/*
4144 * sctp_sf_cookie_wait_prm_abort
4145 *
4146 * Section: 4 Note: 2
4147 * Verification Tag:
4148 * Inputs
4149 * (endpoint, asoc)
4150 *
4151 * The RFC does not explicitly address this issue, but is the route through the
4152 * state table when someone issues an abort while in COOKIE_WAIT state.
4153 *
4154 * Outputs
4155 * (timers)
4156 */
4157sctp_disposition_t sctp_sf_cookie_wait_prm_abort(
4158 const struct sctp_endpoint *ep,
4159 const struct sctp_association *asoc,
4160 const sctp_subtype_t type,
4161 void *arg,
4162 sctp_cmd_seq_t *commands)
4163{
4164 struct msghdr *msg = arg;
4165 struct sctp_chunk *abort;
4166 sctp_disposition_t retval;
4167
4168 /* Stop T1-init timer */
4169 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4170 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4171 retval = SCTP_DISPOSITION_CONSUME;
4172
4173 /* Generate ABORT chunk to send the peer */
4174 abort = sctp_make_abort_user(asoc, NULL, msg);
4175 if (!abort)
4176 retval = SCTP_DISPOSITION_NOMEM;
4177 else
4178 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4179
4180 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4181 SCTP_STATE(SCTP_STATE_CLOSED));
4182
4183 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4184
4185 /* Even if we can't send the ABORT due to low memory delete the
4186 * TCB. This is a departure from our typical NOMEM handling.
4187 */
4188
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004189 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4190 SCTP_ERROR(ECONNREFUSED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004191 /* Delete the established association. */
4192 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
4193 SCTP_U32(SCTP_ERROR_USER_ABORT));
4194
4195 return retval;
4196}
4197
4198/*
4199 * sctp_sf_cookie_echoed_prm_abort
4200 *
4201 * Section: 4 Note: 3
4202 * Verification Tag:
4203 * Inputs
4204 * (endpoint, asoc)
4205 *
4206 * The RFC does not explcitly address this issue, but is the route through the
4207 * state table when someone issues an abort while in COOKIE_ECHOED state.
4208 *
4209 * Outputs
4210 * (timers)
4211 */
4212sctp_disposition_t sctp_sf_cookie_echoed_prm_abort(
4213 const struct sctp_endpoint *ep,
4214 const struct sctp_association *asoc,
4215 const sctp_subtype_t type,
4216 void *arg,
4217 sctp_cmd_seq_t *commands)
4218{
4219 /* There is a single T1 timer, so we should be able to use
4220 * common function with the COOKIE-WAIT state.
4221 */
4222 return sctp_sf_cookie_wait_prm_abort(ep, asoc, type, arg, commands);
4223}
4224
4225/*
4226 * sctp_sf_shutdown_pending_prm_abort
4227 *
4228 * Inputs
4229 * (endpoint, asoc)
4230 *
4231 * The RFC does not explicitly address this issue, but is the route through the
4232 * state table when someone issues an abort while in SHUTDOWN-PENDING state.
4233 *
4234 * Outputs
4235 * (timers)
4236 */
4237sctp_disposition_t sctp_sf_shutdown_pending_prm_abort(
4238 const struct sctp_endpoint *ep,
4239 const struct sctp_association *asoc,
4240 const sctp_subtype_t type,
4241 void *arg,
4242 sctp_cmd_seq_t *commands)
4243{
4244 /* Stop the T5-shutdown guard timer. */
4245 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4246 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4247
4248 return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands);
4249}
4250
4251/*
4252 * sctp_sf_shutdown_sent_prm_abort
4253 *
4254 * Inputs
4255 * (endpoint, asoc)
4256 *
4257 * The RFC does not explicitly address this issue, but is the route through the
4258 * state table when someone issues an abort while in SHUTDOWN-SENT state.
4259 *
4260 * Outputs
4261 * (timers)
4262 */
4263sctp_disposition_t sctp_sf_shutdown_sent_prm_abort(
4264 const struct sctp_endpoint *ep,
4265 const struct sctp_association *asoc,
4266 const sctp_subtype_t type,
4267 void *arg,
4268 sctp_cmd_seq_t *commands)
4269{
4270 /* Stop the T2-shutdown timer. */
4271 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4272 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4273
4274 /* Stop the T5-shutdown guard timer. */
4275 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4276 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4277
4278 return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands);
4279}
4280
4281/*
4282 * sctp_sf_cookie_echoed_prm_abort
4283 *
4284 * Inputs
4285 * (endpoint, asoc)
4286 *
4287 * The RFC does not explcitly address this issue, but is the route through the
4288 * state table when someone issues an abort while in COOKIE_ECHOED state.
4289 *
4290 * Outputs
4291 * (timers)
4292 */
4293sctp_disposition_t sctp_sf_shutdown_ack_sent_prm_abort(
4294 const struct sctp_endpoint *ep,
4295 const struct sctp_association *asoc,
4296 const sctp_subtype_t type,
4297 void *arg,
4298 sctp_cmd_seq_t *commands)
4299{
4300 /* The same T2 timer, so we should be able to use
4301 * common function with the SHUTDOWN-SENT state.
4302 */
4303 return sctp_sf_shutdown_sent_prm_abort(ep, asoc, type, arg, commands);
4304}
4305
4306/*
4307 * Process the REQUESTHEARTBEAT primitive
4308 *
4309 * 10.1 ULP-to-SCTP
4310 * J) Request Heartbeat
4311 *
4312 * Format: REQUESTHEARTBEAT(association id, destination transport address)
4313 *
4314 * -> result
4315 *
4316 * Instructs the local endpoint to perform a HeartBeat on the specified
4317 * destination transport address of the given association. The returned
4318 * result should indicate whether the transmission of the HEARTBEAT
4319 * chunk to the destination address is successful.
4320 *
4321 * Mandatory attributes:
4322 *
4323 * o association id - local handle to the SCTP association
4324 *
4325 * o destination transport address - the transport address of the
4326 * association on which a heartbeat should be issued.
4327 */
4328sctp_disposition_t sctp_sf_do_prm_requestheartbeat(
4329 const struct sctp_endpoint *ep,
4330 const struct sctp_association *asoc,
4331 const sctp_subtype_t type,
4332 void *arg,
4333 sctp_cmd_seq_t *commands)
4334{
4335 return sctp_sf_heartbeat(ep, asoc, type, (struct sctp_transport *)arg,
4336 commands);
4337}
4338
4339/*
4340 * ADDIP Section 4.1 ASCONF Chunk Procedures
4341 * When an endpoint has an ASCONF signaled change to be sent to the
4342 * remote endpoint it should do A1 to A9
4343 */
4344sctp_disposition_t sctp_sf_do_prm_asconf(const struct sctp_endpoint *ep,
4345 const struct sctp_association *asoc,
4346 const sctp_subtype_t type,
4347 void *arg,
4348 sctp_cmd_seq_t *commands)
4349{
4350 struct sctp_chunk *chunk = arg;
4351
4352 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
4353 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4354 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
4355 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
4356 return SCTP_DISPOSITION_CONSUME;
4357}
4358
4359/*
4360 * Ignore the primitive event
4361 *
4362 * The return value is the disposition of the primitive.
4363 */
4364sctp_disposition_t sctp_sf_ignore_primitive(
4365 const struct sctp_endpoint *ep,
4366 const struct sctp_association *asoc,
4367 const sctp_subtype_t type,
4368 void *arg,
4369 sctp_cmd_seq_t *commands)
4370{
4371 SCTP_DEBUG_PRINTK("Primitive type %d is ignored.\n", type.primitive);
4372 return SCTP_DISPOSITION_DISCARD;
4373}
4374
4375/***************************************************************************
4376 * These are the state functions for the OTHER events.
4377 ***************************************************************************/
4378
4379/*
4380 * Start the shutdown negotiation.
4381 *
4382 * From Section 9.2:
4383 * Once all its outstanding data has been acknowledged, the endpoint
4384 * shall send a SHUTDOWN chunk to its peer including in the Cumulative
4385 * TSN Ack field the last sequential TSN it has received from the peer.
4386 * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT
4387 * state. If the timer expires, the endpoint must re-send the SHUTDOWN
4388 * with the updated last sequential TSN received from its peer.
4389 *
4390 * The return value is the disposition.
4391 */
4392sctp_disposition_t sctp_sf_do_9_2_start_shutdown(
4393 const struct sctp_endpoint *ep,
4394 const struct sctp_association *asoc,
4395 const sctp_subtype_t type,
4396 void *arg,
4397 sctp_cmd_seq_t *commands)
4398{
4399 struct sctp_chunk *reply;
4400
4401 /* Once all its outstanding data has been acknowledged, the
4402 * endpoint shall send a SHUTDOWN chunk to its peer including
4403 * in the Cumulative TSN Ack field the last sequential TSN it
4404 * has received from the peer.
4405 */
4406 reply = sctp_make_shutdown(asoc, NULL);
4407 if (!reply)
4408 goto nomem;
4409
4410 /* Set the transport for the SHUTDOWN chunk and the timeout for the
4411 * T2-shutdown timer.
4412 */
4413 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
4414
4415 /* It shall then start the T2-shutdown timer */
4416 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4417 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4418
4419 if (asoc->autoclose)
4420 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4421 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
4422
4423 /* and enter the SHUTDOWN-SENT state. */
4424 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4425 SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT));
4426
4427 /* sctp-implguide 2.10 Issues with Heartbeating and failover
4428 *
4429 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
4430 * or SHUTDOWN-ACK.
4431 */
4432 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
4433
4434 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
4435
4436 return SCTP_DISPOSITION_CONSUME;
4437
4438nomem:
4439 return SCTP_DISPOSITION_NOMEM;
4440}
4441
4442/*
4443 * Generate a SHUTDOWN ACK now that everything is SACK'd.
4444 *
4445 * From Section 9.2:
4446 *
4447 * If it has no more outstanding DATA chunks, the SHUTDOWN receiver
4448 * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own,
4449 * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the
4450 * endpoint must re-send the SHUTDOWN ACK.
4451 *
4452 * The return value is the disposition.
4453 */
4454sctp_disposition_t sctp_sf_do_9_2_shutdown_ack(
4455 const struct sctp_endpoint *ep,
4456 const struct sctp_association *asoc,
4457 const sctp_subtype_t type,
4458 void *arg,
4459 sctp_cmd_seq_t *commands)
4460{
4461 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
4462 struct sctp_chunk *reply;
4463
4464 /* There are 2 ways of getting here:
4465 * 1) called in response to a SHUTDOWN chunk
4466 * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued.
4467 *
4468 * For the case (2), the arg parameter is set to NULL. We need
4469 * to check that we have a chunk before accessing it's fields.
4470 */
4471 if (chunk) {
4472 if (!sctp_vtag_verify(chunk, asoc))
4473 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
4474
4475 /* Make sure that the SHUTDOWN chunk has a valid length. */
4476 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_shutdown_chunk_t)))
4477 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
4478 commands);
4479 }
4480
4481 /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
4482 * shall send a SHUTDOWN ACK ...
4483 */
4484 reply = sctp_make_shutdown_ack(asoc, chunk);
4485 if (!reply)
4486 goto nomem;
4487
4488 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
4489 * the T2-shutdown timer.
4490 */
4491 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
4492
4493 /* and start/restart a T2-shutdown timer of its own, */
4494 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
4495 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4496
4497 if (asoc->autoclose)
4498 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4499 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
4500
4501 /* Enter the SHUTDOWN-ACK-SENT state. */
4502 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4503 SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT));
4504
4505 /* sctp-implguide 2.10 Issues with Heartbeating and failover
4506 *
4507 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
4508 * or SHUTDOWN-ACK.
4509 */
4510 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
4511
4512 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
4513
4514 return SCTP_DISPOSITION_CONSUME;
4515
4516nomem:
4517 return SCTP_DISPOSITION_NOMEM;
4518}
4519
4520/*
4521 * Ignore the event defined as other
4522 *
4523 * The return value is the disposition of the event.
4524 */
4525sctp_disposition_t sctp_sf_ignore_other(const struct sctp_endpoint *ep,
4526 const struct sctp_association *asoc,
4527 const sctp_subtype_t type,
4528 void *arg,
4529 sctp_cmd_seq_t *commands)
4530{
4531 SCTP_DEBUG_PRINTK("The event other type %d is ignored\n", type.other);
4532 return SCTP_DISPOSITION_DISCARD;
4533}
4534
4535/************************************************************
4536 * These are the state functions for handling timeout events.
4537 ************************************************************/
4538
4539/*
4540 * RTX Timeout
4541 *
4542 * Section: 6.3.3 Handle T3-rtx Expiration
4543 *
4544 * Whenever the retransmission timer T3-rtx expires for a destination
4545 * address, do the following:
4546 * [See below]
4547 *
4548 * The return value is the disposition of the chunk.
4549 */
4550sctp_disposition_t sctp_sf_do_6_3_3_rtx(const struct sctp_endpoint *ep,
4551 const struct sctp_association *asoc,
4552 const sctp_subtype_t type,
4553 void *arg,
4554 sctp_cmd_seq_t *commands)
4555{
4556 struct sctp_transport *transport = arg;
4557
4558 if (asoc->overall_error_count >= asoc->max_retrans) {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004559 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4560 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004561 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
4562 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4563 SCTP_U32(SCTP_ERROR_NO_ERROR));
4564 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4565 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
4566 return SCTP_DISPOSITION_DELETE_TCB;
4567 }
4568
4569 /* E1) For the destination address for which the timer
4570 * expires, adjust its ssthresh with rules defined in Section
4571 * 7.2.3 and set the cwnd <- MTU.
4572 */
4573
4574 /* E2) For the destination address for which the timer
4575 * expires, set RTO <- RTO * 2 ("back off the timer"). The
4576 * maximum value discussed in rule C7 above (RTO.max) may be
4577 * used to provide an upper bound to this doubling operation.
4578 */
4579
4580 /* E3) Determine how many of the earliest (i.e., lowest TSN)
4581 * outstanding DATA chunks for the address for which the
4582 * T3-rtx has expired will fit into a single packet, subject
4583 * to the MTU constraint for the path corresponding to the
4584 * destination transport address to which the retransmission
4585 * is being sent (this may be different from the address for
4586 * which the timer expires [see Section 6.4]). Call this
4587 * value K. Bundle and retransmit those K DATA chunks in a
4588 * single packet to the destination endpoint.
4589 *
4590 * Note: Any DATA chunks that were sent to the address for
4591 * which the T3-rtx timer expired but did not fit in one MTU
4592 * (rule E3 above), should be marked for retransmission and
4593 * sent as soon as cwnd allows (normally when a SACK arrives).
4594 */
4595
4596 /* NB: Rules E4 and F1 are implicit in R1. */
4597 sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN, SCTP_TRANSPORT(transport));
4598
4599 /* Do some failure management (Section 8.2). */
4600 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
4601
4602 return SCTP_DISPOSITION_CONSUME;
4603}
4604
4605/*
4606 * Generate delayed SACK on timeout
4607 *
4608 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
4609 *
4610 * The guidelines on delayed acknowledgement algorithm specified in
4611 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
4612 * acknowledgement SHOULD be generated for at least every second packet
4613 * (not every second DATA chunk) received, and SHOULD be generated
4614 * within 200 ms of the arrival of any unacknowledged DATA chunk. In
4615 * some situations it may be beneficial for an SCTP transmitter to be
4616 * more conservative than the algorithms detailed in this document
4617 * allow. However, an SCTP transmitter MUST NOT be more aggressive than
4618 * the following algorithms allow.
4619 */
4620sctp_disposition_t sctp_sf_do_6_2_sack(const struct sctp_endpoint *ep,
4621 const struct sctp_association *asoc,
4622 const sctp_subtype_t type,
4623 void *arg,
4624 sctp_cmd_seq_t *commands)
4625{
4626 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
4627 return SCTP_DISPOSITION_CONSUME;
4628}
4629
4630/*
Frank Filz3f7a87d2005-06-20 13:14:57 -07004631 * sctp_sf_t1_init_timer_expire
Linus Torvalds1da177e2005-04-16 15:20:36 -07004632 *
4633 * Section: 4 Note: 2
4634 * Verification Tag:
4635 * Inputs
4636 * (endpoint, asoc)
4637 *
4638 * RFC 2960 Section 4 Notes
4639 * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT
4640 * and re-start the T1-init timer without changing state. This MUST
4641 * be repeated up to 'Max.Init.Retransmits' times. After that, the
4642 * endpoint MUST abort the initialization process and report the
4643 * error to SCTP user.
4644 *
Frank Filz3f7a87d2005-06-20 13:14:57 -07004645 * Outputs
4646 * (timers, events)
4647 *
4648 */
4649sctp_disposition_t sctp_sf_t1_init_timer_expire(const struct sctp_endpoint *ep,
4650 const struct sctp_association *asoc,
4651 const sctp_subtype_t type,
4652 void *arg,
4653 sctp_cmd_seq_t *commands)
4654{
4655 struct sctp_chunk *repl = NULL;
4656 struct sctp_bind_addr *bp;
4657 int attempts = asoc->init_err_counter + 1;
4658
4659 SCTP_DEBUG_PRINTK("Timer T1 expired (INIT).\n");
4660
Vlad Yasevich81845c22006-01-30 15:59:54 -08004661 if (attempts <= asoc->max_init_attempts) {
Frank Filz3f7a87d2005-06-20 13:14:57 -07004662 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
4663 repl = sctp_make_init(asoc, bp, GFP_ATOMIC, 0);
4664 if (!repl)
4665 return SCTP_DISPOSITION_NOMEM;
4666
4667 /* Choose transport for INIT. */
4668 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
4669 SCTP_CHUNK(repl));
4670
4671 /* Issue a sideeffect to do the needed accounting. */
4672 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_RESTART,
4673 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4674
4675 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
4676 } else {
4677 SCTP_DEBUG_PRINTK("Giving up on INIT, attempts: %d"
4678 " max_init_attempts: %d\n",
4679 attempts, asoc->max_init_attempts);
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004680 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4681 SCTP_ERROR(ETIMEDOUT));
Frank Filz3f7a87d2005-06-20 13:14:57 -07004682 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
4683 SCTP_U32(SCTP_ERROR_NO_ERROR));
4684 return SCTP_DISPOSITION_DELETE_TCB;
4685 }
4686
4687 return SCTP_DISPOSITION_CONSUME;
4688}
4689
4690/*
4691 * sctp_sf_t1_cookie_timer_expire
4692 *
4693 * Section: 4 Note: 2
4694 * Verification Tag:
4695 * Inputs
4696 * (endpoint, asoc)
4697 *
4698 * RFC 2960 Section 4 Notes
4699 * 3) If the T1-cookie timer expires, the endpoint MUST retransmit
Linus Torvalds1da177e2005-04-16 15:20:36 -07004700 * COOKIE ECHO and re-start the T1-cookie timer without changing
4701 * state. This MUST be repeated up to 'Max.Init.Retransmits' times.
4702 * After that, the endpoint MUST abort the initialization process and
4703 * report the error to SCTP user.
4704 *
4705 * Outputs
4706 * (timers, events)
4707 *
4708 */
Frank Filz3f7a87d2005-06-20 13:14:57 -07004709sctp_disposition_t sctp_sf_t1_cookie_timer_expire(const struct sctp_endpoint *ep,
Linus Torvalds1da177e2005-04-16 15:20:36 -07004710 const struct sctp_association *asoc,
4711 const sctp_subtype_t type,
4712 void *arg,
4713 sctp_cmd_seq_t *commands)
4714{
Frank Filz3f7a87d2005-06-20 13:14:57 -07004715 struct sctp_chunk *repl = NULL;
4716 int attempts = asoc->init_err_counter + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004717
Frank Filz3f7a87d2005-06-20 13:14:57 -07004718 SCTP_DEBUG_PRINTK("Timer T1 expired (COOKIE-ECHO).\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07004719
Vlad Yasevich81845c22006-01-30 15:59:54 -08004720 if (attempts <= asoc->max_init_attempts) {
Frank Filz3f7a87d2005-06-20 13:14:57 -07004721 repl = sctp_make_cookie_echo(asoc, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07004722 if (!repl)
Frank Filz3f7a87d2005-06-20 13:14:57 -07004723 return SCTP_DISPOSITION_NOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004724
4725 /* Issue a sideeffect to do the needed accounting. */
Frank Filz3f7a87d2005-06-20 13:14:57 -07004726 sctp_add_cmd_sf(commands, SCTP_CMD_COOKIEECHO_RESTART,
4727 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
4728
Linus Torvalds1da177e2005-04-16 15:20:36 -07004729 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
4730 } else {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004731 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4732 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004733 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
4734 SCTP_U32(SCTP_ERROR_NO_ERROR));
4735 return SCTP_DISPOSITION_DELETE_TCB;
4736 }
4737
4738 return SCTP_DISPOSITION_CONSUME;
Linus Torvalds1da177e2005-04-16 15:20:36 -07004739}
4740
4741/* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN
4742 * with the updated last sequential TSN received from its peer.
4743 *
4744 * An endpoint should limit the number of retransmissions of the
4745 * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'.
4746 * If this threshold is exceeded the endpoint should destroy the TCB and
4747 * MUST report the peer endpoint unreachable to the upper layer (and
4748 * thus the association enters the CLOSED state). The reception of any
4749 * packet from its peer (i.e. as the peer sends all of its queued DATA
4750 * chunks) should clear the endpoint's retransmission count and restart
4751 * the T2-Shutdown timer, giving its peer ample opportunity to transmit
4752 * all of its queued DATA chunks that have not yet been sent.
4753 */
4754sctp_disposition_t sctp_sf_t2_timer_expire(const struct sctp_endpoint *ep,
4755 const struct sctp_association *asoc,
4756 const sctp_subtype_t type,
4757 void *arg,
4758 sctp_cmd_seq_t *commands)
4759{
4760 struct sctp_chunk *reply = NULL;
4761
4762 SCTP_DEBUG_PRINTK("Timer T2 expired.\n");
4763 if (asoc->overall_error_count >= asoc->max_retrans) {
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004764 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4765 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004766 /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
4767 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4768 SCTP_U32(SCTP_ERROR_NO_ERROR));
4769 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4770 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
4771 return SCTP_DISPOSITION_DELETE_TCB;
4772 }
4773
4774 switch (asoc->state) {
4775 case SCTP_STATE_SHUTDOWN_SENT:
4776 reply = sctp_make_shutdown(asoc, NULL);
4777 break;
4778
4779 case SCTP_STATE_SHUTDOWN_ACK_SENT:
4780 reply = sctp_make_shutdown_ack(asoc, NULL);
4781 break;
4782
4783 default:
4784 BUG();
4785 break;
4786 };
4787
4788 if (!reply)
4789 goto nomem;
4790
4791 /* Do some failure management (Section 8.2). */
4792 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
4793 SCTP_TRANSPORT(asoc->shutdown_last_sent_to));
4794
4795 /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for
4796 * the T2-shutdown timer.
4797 */
4798 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
4799
4800 /* Restart the T2-shutdown timer. */
4801 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
4802 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4803 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
4804 return SCTP_DISPOSITION_CONSUME;
4805
4806nomem:
4807 return SCTP_DISPOSITION_NOMEM;
4808}
4809
4810/*
4811 * ADDIP Section 4.1 ASCONF CHunk Procedures
4812 * If the T4 RTO timer expires the endpoint should do B1 to B5
4813 */
4814sctp_disposition_t sctp_sf_t4_timer_expire(
4815 const struct sctp_endpoint *ep,
4816 const struct sctp_association *asoc,
4817 const sctp_subtype_t type,
4818 void *arg,
4819 sctp_cmd_seq_t *commands)
4820{
4821 struct sctp_chunk *chunk = asoc->addip_last_asconf;
4822 struct sctp_transport *transport = chunk->transport;
4823
4824 /* ADDIP 4.1 B1) Increment the error counters and perform path failure
4825 * detection on the appropriate destination address as defined in
4826 * RFC2960 [5] section 8.1 and 8.2.
4827 */
4828 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
4829
4830 /* Reconfig T4 timer and transport. */
4831 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
4832
4833 /* ADDIP 4.1 B2) Increment the association error counters and perform
4834 * endpoint failure detection on the association as defined in
4835 * RFC2960 [5] section 8.1 and 8.2.
4836 * association error counter is incremented in SCTP_CMD_STRIKE.
4837 */
4838 if (asoc->overall_error_count >= asoc->max_retrans) {
4839 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4840 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004841 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4842 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004843 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4844 SCTP_U32(SCTP_ERROR_NO_ERROR));
4845 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4846 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
4847 return SCTP_DISPOSITION_ABORT;
4848 }
4849
4850 /* ADDIP 4.1 B3) Back-off the destination address RTO value to which
4851 * the ASCONF chunk was sent by doubling the RTO timer value.
4852 * This is done in SCTP_CMD_STRIKE.
4853 */
4854
4855 /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible
4856 * choose an alternate destination address (please refer to RFC2960
4857 * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this
4858 * chunk, it MUST be the same (including its serial number) as the last
4859 * ASCONF sent.
4860 */
4861 sctp_chunk_hold(asoc->addip_last_asconf);
4862 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4863 SCTP_CHUNK(asoc->addip_last_asconf));
4864
4865 /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different
4866 * destination is selected, then the RTO used will be that of the new
4867 * destination address.
4868 */
4869 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
4870 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
4871
4872 return SCTP_DISPOSITION_CONSUME;
4873}
4874
4875/* sctpimpguide-05 Section 2.12.2
4876 * The sender of the SHUTDOWN MAY also start an overall guard timer
4877 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
4878 * At the expiration of this timer the sender SHOULD abort the association
4879 * by sending an ABORT chunk.
4880 */
4881sctp_disposition_t sctp_sf_t5_timer_expire(const struct sctp_endpoint *ep,
4882 const struct sctp_association *asoc,
4883 const sctp_subtype_t type,
4884 void *arg,
4885 sctp_cmd_seq_t *commands)
4886{
4887 struct sctp_chunk *reply = NULL;
4888
4889 SCTP_DEBUG_PRINTK("Timer T5 expired.\n");
4890
4891 reply = sctp_make_abort(asoc, NULL, 0);
4892 if (!reply)
4893 goto nomem;
4894
4895 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07004896 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4897 SCTP_ERROR(ETIMEDOUT));
Linus Torvalds1da177e2005-04-16 15:20:36 -07004898 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4899 SCTP_U32(SCTP_ERROR_NO_ERROR));
4900
4901 return SCTP_DISPOSITION_DELETE_TCB;
4902nomem:
4903 return SCTP_DISPOSITION_NOMEM;
4904}
4905
4906/* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires,
4907 * the association is automatically closed by starting the shutdown process.
4908 * The work that needs to be done is same as when SHUTDOWN is initiated by
4909 * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown().
4910 */
4911sctp_disposition_t sctp_sf_autoclose_timer_expire(
4912 const struct sctp_endpoint *ep,
4913 const struct sctp_association *asoc,
4914 const sctp_subtype_t type,
4915 void *arg,
4916 sctp_cmd_seq_t *commands)
4917{
4918 int disposition;
4919
4920 /* From 9.2 Shutdown of an Association
4921 * Upon receipt of the SHUTDOWN primitive from its upper
4922 * layer, the endpoint enters SHUTDOWN-PENDING state and
4923 * remains there until all outstanding data has been
4924 * acknowledged by its peer. The endpoint accepts no new data
4925 * from its upper layer, but retransmits data to the far end
4926 * if necessary to fill gaps.
4927 */
4928 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4929 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
4930
4931 /* sctpimpguide-05 Section 2.12.2
4932 * The sender of the SHUTDOWN MAY also start an overall guard timer
4933 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
4934 */
4935 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4936 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4937 disposition = SCTP_DISPOSITION_CONSUME;
4938 if (sctp_outq_is_empty(&asoc->outqueue)) {
4939 disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type,
4940 arg, commands);
4941 }
4942 return disposition;
4943}
4944
4945/*****************************************************************************
4946 * These are sa state functions which could apply to all types of events.
4947 ****************************************************************************/
4948
4949/*
4950 * This table entry is not implemented.
4951 *
4952 * Inputs
4953 * (endpoint, asoc, chunk)
4954 *
4955 * The return value is the disposition of the chunk.
4956 */
4957sctp_disposition_t sctp_sf_not_impl(const struct sctp_endpoint *ep,
4958 const struct sctp_association *asoc,
4959 const sctp_subtype_t type,
4960 void *arg,
4961 sctp_cmd_seq_t *commands)
4962{
4963 return SCTP_DISPOSITION_NOT_IMPL;
4964}
4965
4966/*
4967 * This table entry represents a bug.
4968 *
4969 * Inputs
4970 * (endpoint, asoc, chunk)
4971 *
4972 * The return value is the disposition of the chunk.
4973 */
4974sctp_disposition_t sctp_sf_bug(const struct sctp_endpoint *ep,
4975 const struct sctp_association *asoc,
4976 const sctp_subtype_t type,
4977 void *arg,
4978 sctp_cmd_seq_t *commands)
4979{
4980 return SCTP_DISPOSITION_BUG;
4981}
4982
4983/*
4984 * This table entry represents the firing of a timer in the wrong state.
4985 * Since timer deletion cannot be guaranteed a timer 'may' end up firing
4986 * when the association is in the wrong state. This event should
4987 * be ignored, so as to prevent any rearming of the timer.
4988 *
4989 * Inputs
4990 * (endpoint, asoc, chunk)
4991 *
4992 * The return value is the disposition of the chunk.
4993 */
4994sctp_disposition_t sctp_sf_timer_ignore(const struct sctp_endpoint *ep,
4995 const struct sctp_association *asoc,
4996 const sctp_subtype_t type,
4997 void *arg,
4998 sctp_cmd_seq_t *commands)
4999{
5000 SCTP_DEBUG_PRINTK("Timer %d ignored.\n", type.chunk);
5001 return SCTP_DISPOSITION_CONSUME;
5002}
5003
5004/********************************************************************
5005 * 2nd Level Abstractions
5006 ********************************************************************/
5007
5008/* Pull the SACK chunk based on the SACK header. */
5009static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk)
5010{
5011 struct sctp_sackhdr *sack;
5012 unsigned int len;
5013 __u16 num_blocks;
5014 __u16 num_dup_tsns;
5015
5016 /* Protect ourselves from reading too far into
5017 * the skb from a bogus sender.
5018 */
5019 sack = (struct sctp_sackhdr *) chunk->skb->data;
5020
5021 num_blocks = ntohs(sack->num_gap_ack_blocks);
5022 num_dup_tsns = ntohs(sack->num_dup_tsns);
5023 len = sizeof(struct sctp_sackhdr);
5024 len += (num_blocks + num_dup_tsns) * sizeof(__u32);
5025 if (len > chunk->skb->len)
5026 return NULL;
5027
5028 skb_pull(chunk->skb, len);
5029
5030 return sack;
5031}
5032
5033/* Create an ABORT packet to be sent as a response, with the specified
5034 * error causes.
5035 */
5036static struct sctp_packet *sctp_abort_pkt_new(const struct sctp_endpoint *ep,
5037 const struct sctp_association *asoc,
5038 struct sctp_chunk *chunk,
5039 const void *payload,
5040 size_t paylen)
5041{
5042 struct sctp_packet *packet;
5043 struct sctp_chunk *abort;
5044
5045 packet = sctp_ootb_pkt_new(asoc, chunk);
5046
5047 if (packet) {
5048 /* Make an ABORT.
5049 * The T bit will be set if the asoc is NULL.
5050 */
5051 abort = sctp_make_abort(asoc, chunk, paylen);
5052 if (!abort) {
5053 sctp_ootb_pkt_free(packet);
5054 return NULL;
5055 }
Jerome Forissier047a2422005-04-28 11:58:43 -07005056
5057 /* Reflect vtag if T-Bit is set */
5058 if (sctp_test_T_bit(abort))
5059 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
5060
Linus Torvalds1da177e2005-04-16 15:20:36 -07005061 /* Add specified error causes, i.e., payload, to the
5062 * end of the chunk.
5063 */
5064 sctp_addto_chunk(abort, paylen, payload);
5065
5066 /* Set the skb to the belonging sock for accounting. */
5067 abort->skb->sk = ep->base.sk;
5068
5069 sctp_packet_append_chunk(packet, abort);
5070
5071 }
5072
5073 return packet;
5074}
5075
5076/* Allocate a packet for responding in the OOTB conditions. */
5077static struct sctp_packet *sctp_ootb_pkt_new(const struct sctp_association *asoc,
5078 const struct sctp_chunk *chunk)
5079{
5080 struct sctp_packet *packet;
5081 struct sctp_transport *transport;
5082 __u16 sport;
5083 __u16 dport;
5084 __u32 vtag;
5085
5086 /* Get the source and destination port from the inbound packet. */
5087 sport = ntohs(chunk->sctp_hdr->dest);
5088 dport = ntohs(chunk->sctp_hdr->source);
5089
5090 /* The V-tag is going to be the same as the inbound packet if no
5091 * association exists, otherwise, use the peer's vtag.
5092 */
5093 if (asoc) {
5094 vtag = asoc->peer.i.init_tag;
5095 } else {
5096 /* Special case the INIT and stale COOKIE_ECHO as there is no
5097 * vtag yet.
5098 */
5099 switch(chunk->chunk_hdr->type) {
5100 case SCTP_CID_INIT:
5101 {
5102 sctp_init_chunk_t *init;
5103
5104 init = (sctp_init_chunk_t *)chunk->chunk_hdr;
5105 vtag = ntohl(init->init_hdr.init_tag);
5106 break;
5107 }
5108 default:
5109 vtag = ntohl(chunk->sctp_hdr->vtag);
5110 break;
5111 }
5112 }
5113
5114 /* Make a transport for the bucket, Eliza... */
5115 transport = sctp_transport_new(sctp_source(chunk), GFP_ATOMIC);
5116 if (!transport)
5117 goto nomem;
5118
5119 /* Cache a route for the transport with the chunk's destination as
5120 * the source address.
5121 */
5122 sctp_transport_route(transport, (union sctp_addr *)&chunk->dest,
5123 sctp_sk(sctp_get_ctl_sock()));
5124
5125 packet = sctp_packet_init(&transport->packet, transport, sport, dport);
5126 packet = sctp_packet_config(packet, vtag, 0);
5127
5128 return packet;
5129
5130nomem:
5131 return NULL;
5132}
5133
5134/* Free the packet allocated earlier for responding in the OOTB condition. */
5135void sctp_ootb_pkt_free(struct sctp_packet *packet)
5136{
5137 sctp_transport_free(packet->transport);
5138}
5139
5140/* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */
5141static void sctp_send_stale_cookie_err(const struct sctp_endpoint *ep,
5142 const struct sctp_association *asoc,
5143 const struct sctp_chunk *chunk,
5144 sctp_cmd_seq_t *commands,
5145 struct sctp_chunk *err_chunk)
5146{
5147 struct sctp_packet *packet;
5148
5149 if (err_chunk) {
5150 packet = sctp_ootb_pkt_new(asoc, chunk);
5151 if (packet) {
5152 struct sctp_signed_cookie *cookie;
5153
5154 /* Override the OOTB vtag from the cookie. */
5155 cookie = chunk->subh.cookie_hdr;
5156 packet->vtag = cookie->c.peer_vtag;
5157
5158 /* Set the skb to the belonging sock for accounting. */
5159 err_chunk->skb->sk = ep->base.sk;
5160 sctp_packet_append_chunk(packet, err_chunk);
5161 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
5162 SCTP_PACKET(packet));
5163 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
5164 } else
5165 sctp_chunk_free (err_chunk);
5166 }
5167}
5168
5169
5170/* Process a data chunk */
5171static int sctp_eat_data(const struct sctp_association *asoc,
5172 struct sctp_chunk *chunk,
5173 sctp_cmd_seq_t *commands)
5174{
5175 sctp_datahdr_t *data_hdr;
5176 struct sctp_chunk *err;
5177 size_t datalen;
5178 sctp_verb_t deliver;
5179 int tmp;
5180 __u32 tsn;
Neil Horman049b3ff2005-11-11 16:08:24 -08005181 int account_value;
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005182 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
Neil Horman049b3ff2005-11-11 16:08:24 -08005183 struct sock *sk = asoc->base.sk;
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005184 int rcvbuf_over = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005185
5186 data_hdr = chunk->subh.data_hdr = (sctp_datahdr_t *)chunk->skb->data;
5187 skb_pull(chunk->skb, sizeof(sctp_datahdr_t));
5188
5189 tsn = ntohl(data_hdr->tsn);
5190 SCTP_DEBUG_PRINTK("eat_data: TSN 0x%x.\n", tsn);
5191
5192 /* ASSERT: Now skb->data is really the user data. */
5193
Neil Horman049b3ff2005-11-11 16:08:24 -08005194 /*
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005195 * If we are established, and we have used up our receive buffer
5196 * memory, think about droping the frame.
5197 * Note that we have an opportunity to improve performance here.
5198 * If we accept one chunk from an skbuff, we have to keep all the
5199 * memory of that skbuff around until the chunk is read into user
5200 * space. Therefore, once we accept 1 chunk we may as well accept all
5201 * remaining chunks in the skbuff. The data_accepted flag helps us do
5202 * that.
Neil Horman049b3ff2005-11-11 16:08:24 -08005203 */
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005204 if ((asoc->state == SCTP_STATE_ESTABLISHED) && (!chunk->data_accepted)) {
Neil Horman049b3ff2005-11-11 16:08:24 -08005205 /*
5206 * If the receive buffer policy is 1, then each
5207 * association can allocate up to sk_rcvbuf bytes
5208 * otherwise, all the associations in aggregate
5209 * may allocate up to sk_rcvbuf bytes
5210 */
5211 if (asoc->ep->rcvbuf_policy)
5212 account_value = atomic_read(&asoc->rmem_alloc);
5213 else
5214 account_value = atomic_read(&sk->sk_rmem_alloc);
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005215 if (account_value > sk->sk_rcvbuf) {
5216 /*
5217 * We need to make forward progress, even when we are
5218 * under memory pressure, so we always allow the
5219 * next tsn after the ctsn ack point to be accepted.
5220 * This lets us avoid deadlocks in which we have to
5221 * drop frames that would otherwise let us drain the
5222 * receive queue.
5223 */
5224 if ((sctp_tsnmap_get_ctsn(map) + 1) != tsn)
5225 return SCTP_IERROR_IGNORE_TSN;
Neil Horman049b3ff2005-11-11 16:08:24 -08005226
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005227 /*
5228 * We're going to accept the frame but we should renege
5229 * to make space for it. This will send us down that
5230 * path later in this function.
5231 */
5232 rcvbuf_over = 1;
5233 }
Neil Horman049b3ff2005-11-11 16:08:24 -08005234 }
5235
Linus Torvalds1da177e2005-04-16 15:20:36 -07005236 /* Process ECN based congestion.
5237 *
5238 * Since the chunk structure is reused for all chunks within
5239 * a packet, we use ecn_ce_done to track if we've already
5240 * done CE processing for this packet.
5241 *
5242 * We need to do ECN processing even if we plan to discard the
5243 * chunk later.
5244 */
5245
5246 if (!chunk->ecn_ce_done) {
5247 struct sctp_af *af;
5248 chunk->ecn_ce_done = 1;
5249
5250 af = sctp_get_af_specific(
5251 ipver2af(chunk->skb->nh.iph->version));
5252
5253 if (af && af->is_ce(chunk->skb) && asoc->peer.ecn_capable) {
5254 /* Do real work as sideffect. */
5255 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_CE,
5256 SCTP_U32(tsn));
5257 }
5258 }
5259
5260 tmp = sctp_tsnmap_check(&asoc->peer.tsn_map, tsn);
5261 if (tmp < 0) {
5262 /* The TSN is too high--silently discard the chunk and
5263 * count on it getting retransmitted later.
5264 */
5265 return SCTP_IERROR_HIGH_TSN;
5266 } else if (tmp > 0) {
5267 /* This is a duplicate. Record it. */
5268 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_DUP, SCTP_U32(tsn));
5269 return SCTP_IERROR_DUP_TSN;
5270 }
5271
5272 /* This is a new TSN. */
5273
5274 /* Discard if there is no room in the receive window.
5275 * Actually, allow a little bit of overflow (up to a MTU).
5276 */
5277 datalen = ntohs(chunk->chunk_hdr->length);
5278 datalen -= sizeof(sctp_data_chunk_t);
5279
5280 deliver = SCTP_CMD_CHUNK_ULP;
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005281 chunk->data_accepted = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -07005282
5283 /* Think about partial delivery. */
5284 if ((datalen >= asoc->rwnd) && (!asoc->ulpq.pd_mode)) {
5285
5286 /* Even if we don't accept this chunk there is
5287 * memory pressure.
5288 */
5289 sctp_add_cmd_sf(commands, SCTP_CMD_PART_DELIVER, SCTP_NULL());
5290 }
5291
5292 /* Spill over rwnd a little bit. Note: While allowed, this spill over
5293 * seems a bit troublesome in that frag_point varies based on
5294 * PMTU. In cases, such as loopback, this might be a rather
5295 * large spill over.
Neil Hormand5b9f4c2006-06-17 22:59:03 -07005296 * NOTE: If we have a full receive buffer here, we only renege if
5297 * our receiver can still make progress without the tsn being
5298 * received. We do this because in the event that the associations
5299 * receive queue is empty we are filling a leading gap, and since
5300 * reneging moves the gap to the end of the tsn stream, we are likely
5301 * to stall again very shortly. Avoiding the renege when we fill a
5302 * leading gap is a good heuristic for avoiding such steady state
5303 * stalls.
Linus Torvalds1da177e2005-04-16 15:20:36 -07005304 */
5305 if (!asoc->rwnd || asoc->rwnd_over ||
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005306 (datalen > asoc->rwnd + asoc->frag_point) ||
Neil Hormand5b9f4c2006-06-17 22:59:03 -07005307 (rcvbuf_over && (!skb_queue_len(&sk->sk_receive_queue)))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07005308
5309 /* If this is the next TSN, consider reneging to make
5310 * room. Note: Playing nice with a confused sender. A
5311 * malicious sender can still eat up all our buffer
5312 * space and in the future we may want to detect and
5313 * do more drastic reneging.
5314 */
Neil Horman7c3ceb4f2006-05-05 17:02:09 -07005315 if (sctp_tsnmap_has_gap(map) &&
5316 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07005317 SCTP_DEBUG_PRINTK("Reneging for tsn:%u\n", tsn);
5318 deliver = SCTP_CMD_RENEGE;
5319 } else {
5320 SCTP_DEBUG_PRINTK("Discard tsn: %u len: %Zd, "
5321 "rwnd: %d\n", tsn, datalen,
5322 asoc->rwnd);
5323 return SCTP_IERROR_IGNORE_TSN;
5324 }
5325 }
5326
5327 /*
5328 * Section 3.3.10.9 No User Data (9)
5329 *
5330 * Cause of error
5331 * ---------------
5332 * No User Data: This error cause is returned to the originator of a
5333 * DATA chunk if a received DATA chunk has no user data.
5334 */
5335 if (unlikely(0 == datalen)) {
5336 err = sctp_make_abort_no_data(asoc, chunk, tsn);
5337 if (err) {
5338 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
5339 SCTP_CHUNK(err));
5340 }
5341 /* We are going to ABORT, so we might as well stop
5342 * processing the rest of the chunks in the packet.
5343 */
5344 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
Sridhar Samudrala8de8c872006-05-19 10:58:12 -07005345 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5346 SCTP_ERROR(ECONNABORTED));
Linus Torvalds1da177e2005-04-16 15:20:36 -07005347 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5348 SCTP_U32(SCTP_ERROR_NO_DATA));
5349 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
5350 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
5351 return SCTP_IERROR_NO_DATA;
5352 }
5353
5354 /* If definately accepting the DATA chunk, record its TSN, otherwise
5355 * wait for renege processing.
5356 */
5357 if (SCTP_CMD_CHUNK_ULP == deliver)
5358 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_TSN, SCTP_U32(tsn));
5359
5360 /* Note: Some chunks may get overcounted (if we drop) or overcounted
5361 * if we renege and the chunk arrives again.
5362 */
5363 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
5364 SCTP_INC_STATS(SCTP_MIB_INUNORDERCHUNKS);
5365 else
5366 SCTP_INC_STATS(SCTP_MIB_INORDERCHUNKS);
5367
5368 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
5369 *
5370 * If an endpoint receive a DATA chunk with an invalid stream
5371 * identifier, it shall acknowledge the reception of the DATA chunk
5372 * following the normal procedure, immediately send an ERROR chunk
5373 * with cause set to "Invalid Stream Identifier" (See Section 3.3.10)
5374 * and discard the DATA chunk.
5375 */
5376 if (ntohs(data_hdr->stream) >= asoc->c.sinit_max_instreams) {
5377 err = sctp_make_op_error(asoc, chunk, SCTP_ERROR_INV_STRM,
5378 &data_hdr->stream,
5379 sizeof(data_hdr->stream));
5380 if (err)
5381 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
5382 SCTP_CHUNK(err));
5383 return SCTP_IERROR_BAD_STREAM;
5384 }
5385
5386 /* Send the data up to the user. Note: Schedule the
5387 * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK
5388 * chunk needs the updated rwnd.
5389 */
5390 sctp_add_cmd_sf(commands, deliver, SCTP_CHUNK(chunk));
5391
5392 return SCTP_IERROR_NO_ERROR;
5393}