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[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / sctp / sm_statefuns.c
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1da177e4
LT		 1/* 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
95
96/* Small helper function that checks if the chunk length
97 * is of the appropriate length. The 'required_length' argument
98 * is set to be the size of a specific chunk we are testing.
99 * Return Values: 1 = Valid length
100 * 0 = Invalid length
101 *
102 */
103static inline int
104sctp_chunk_length_valid(struct sctp_chunk *chunk,
105 __u16 required_length)
106{
107 __u16 chunk_length = ntohs(chunk->chunk_hdr->length);
108
109 if (unlikely(chunk_length < required_length))
110 return 0;
111
112 return 1;
113}
114
115/**********************************************************
116 * These are the state functions for handling chunk events.
117 **********************************************************/
118
119/*
120 * Process the final SHUTDOWN COMPLETE.
121 *
122 * Section: 4 (C) (diagram), 9.2
123 * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify
124 * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be
125 * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint
126 * should stop the T2-shutdown timer and remove all knowledge of the
127 * association (and thus the association enters the CLOSED state).
128 *
047a2428 129 * Verification Tag: 8.5.1(C), sctpimpguide 2.41.
1da177e4
LT		 130 * C) Rules for packet carrying SHUTDOWN COMPLETE:
131 * ...
047a2428
JF		 132 * - The receiver of a SHUTDOWN COMPLETE shall accept the packet
133 * if the Verification Tag field of the packet matches its own tag and
134 * the T bit is not set
135 * OR
136 * it is set to its peer's tag and the T bit is set in the Chunk
137 * Flags.
138 * Otherwise, the receiver MUST silently discard the packet
139 * and take no further action. An endpoint MUST ignore the
140 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
1da177e4
LT		 141 *
142 * Inputs
143 * (endpoint, asoc, chunk)
144 *
145 * Outputs
146 * (asoc, reply_msg, msg_up, timers, counters)
147 *
148 * The return value is the disposition of the chunk.
149 */
150sctp_disposition_t sctp_sf_do_4_C(const struct sctp_endpoint *ep,
151 const struct sctp_association *asoc,
152 const sctp_subtype_t type,
153 void *arg,
154 sctp_cmd_seq_t *commands)
155{
156 struct sctp_chunk *chunk = arg;
157 struct sctp_ulpevent *ev;
158
159 /* RFC 2960 6.10 Bundling
160 *
161 * An endpoint MUST NOT bundle INIT, INIT ACK or
162 * SHUTDOWN COMPLETE with any other chunks.
163 */
164 if (!chunk->singleton)
165 return SCTP_DISPOSITION_VIOLATION;
166
167 if (!sctp_vtag_verify_either(chunk, asoc))
168 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
169
170 /* RFC 2960 10.2 SCTP-to-ULP
171 *
172 * H) SHUTDOWN COMPLETE notification
173 *
174 * When SCTP completes the shutdown procedures (section 9.2) this
175 * notification is passed to the upper layer.
176 */
177 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
178 0, 0, 0, GFP_ATOMIC);
179 if (!ev)
180 goto nomem;
181
182 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
183
184 /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint
185 * will verify that it is in SHUTDOWN-ACK-SENT state, if it is
186 * not the chunk should be discarded. If the endpoint is in
187 * the SHUTDOWN-ACK-SENT state the endpoint should stop the
188 * T2-shutdown timer and remove all knowledge of the
189 * association (and thus the association enters the CLOSED
190 * state).
191 */
192 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
193 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
194
195 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
196 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
197
198 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
199 SCTP_STATE(SCTP_STATE_CLOSED));
200
201 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
202 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
203
204 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
205
206 return SCTP_DISPOSITION_DELETE_TCB;
207
208nomem:
209 return SCTP_DISPOSITION_NOMEM;
210}
211
212/*
213 * Respond to a normal INIT chunk.
214 * We are the side that is being asked for an association.
215 *
216 * Section: 5.1 Normal Establishment of an Association, B
217 * B) "Z" shall respond immediately with an INIT ACK chunk. The
218 * destination IP address of the INIT ACK MUST be set to the source
219 * IP address of the INIT to which this INIT ACK is responding. In
220 * the response, besides filling in other parameters, "Z" must set the
221 * Verification Tag field to Tag_A, and also provide its own
222 * Verification Tag (Tag_Z) in the Initiate Tag field.
223 *
224 * Verification Tag: Must be 0.
225 *
226 * Inputs
227 * (endpoint, asoc, chunk)
228 *
229 * Outputs
230 * (asoc, reply_msg, msg_up, timers, counters)
231 *
232 * The return value is the disposition of the chunk.
233 */
234sctp_disposition_t sctp_sf_do_5_1B_init(const struct sctp_endpoint *ep,
235 const struct sctp_association *asoc,
236 const sctp_subtype_t type,
237 void *arg,
238 sctp_cmd_seq_t *commands)
239{
240 struct sctp_chunk *chunk = arg;
241 struct sctp_chunk *repl;
242 struct sctp_association *new_asoc;
243 struct sctp_chunk *err_chunk;
244 struct sctp_packet *packet;
245 sctp_unrecognized_param_t *unk_param;
246 struct sock *sk;
247 int len;
248
249 /* 6.10 Bundling
250 * An endpoint MUST NOT bundle INIT, INIT ACK or
251 * SHUTDOWN COMPLETE with any other chunks.
252 *
253 * IG Section 2.11.2
254 * Furthermore, we require that the receiver of an INIT chunk MUST
255 * enforce these rules by silently discarding an arriving packet
256 * with an INIT chunk that is bundled with other chunks.
257 */
258 if (!chunk->singleton)
259 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
260
261 /* If the packet is an OOTB packet which is temporarily on the
262 * control endpoint, respond with an ABORT.
263 */
264 if (ep == sctp_sk((sctp_get_ctl_sock()))->ep)
265 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
266
267 sk = ep->base.sk;
268 /* If the endpoint is not listening or if the number of associations
269 * on the TCP-style socket exceed the max backlog, respond with an
270 * ABORT.
271 */
272 if (!sctp_sstate(sk, LISTENING) ||
273 (sctp_style(sk, TCP) &&
274 sk_acceptq_is_full(sk)))
275 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
276
277 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
278 * Tag.
279 */
280 if (chunk->sctp_hdr->vtag != 0)
281 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
282
283 /* Make sure that the INIT chunk has a valid length.
284 * Normally, this would cause an ABORT with a Protocol Violation
285 * error, but since we don't have an association, we'll
286 * just discard the packet.
287 */
288 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
289 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
290
291 /* Verify the INIT chunk before processing it. */
292 err_chunk = NULL;
293 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
294 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
295 &err_chunk)) {
296 /* This chunk contains fatal error. It is to be discarded.
297 * Send an ABORT, with causes if there is any.
298 */
299 if (err_chunk) {
300 packet = sctp_abort_pkt_new(ep, asoc, arg,
301 (__u8 *)(err_chunk->chunk_hdr) +
302 sizeof(sctp_chunkhdr_t),
303 ntohs(err_chunk->chunk_hdr->length) -
304 sizeof(sctp_chunkhdr_t));
305
306 sctp_chunk_free(err_chunk);
307
308 if (packet) {
309 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
310 SCTP_PACKET(packet));
311 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
312 return SCTP_DISPOSITION_CONSUME;
313 } else {
314 return SCTP_DISPOSITION_NOMEM;
315 }
316 } else {
317 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg,
318 commands);
319 }
320 }
321
322 /* Grab the INIT header. */
323 chunk->subh.init_hdr = (sctp_inithdr_t *)chunk->skb->data;
324
325 /* Tag the variable length parameters. */
326 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
327
328 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
329 if (!new_asoc)
330 goto nomem;
331
332 /* The call, sctp_process_init(), can fail on memory allocation. */
333 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
334 sctp_source(chunk),
335 (sctp_init_chunk_t *)chunk->chunk_hdr,
336 GFP_ATOMIC))
337 goto nomem_init;
338
339 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
340
341 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
342
343 /* If there are errors need to be reported for unknown parameters,
344 * make sure to reserve enough room in the INIT ACK for them.
345 */
346 len = 0;
347 if (err_chunk)
348 len = ntohs(err_chunk->chunk_hdr->length) -
349 sizeof(sctp_chunkhdr_t);
350
351 if (sctp_assoc_set_bind_addr_from_ep(new_asoc, GFP_ATOMIC) < 0)
352 goto nomem_ack;
353
354 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
355 if (!repl)
356 goto nomem_ack;
357
358 /* If there are errors need to be reported for unknown parameters,
359 * include them in the outgoing INIT ACK as "Unrecognized parameter"
360 * parameter.
361 */
362 if (err_chunk) {
363 /* Get the "Unrecognized parameter" parameter(s) out of the
364 * ERROR chunk generated by sctp_verify_init(). Since the
365 * error cause code for "unknown parameter" and the
366 * "Unrecognized parameter" type is the same, we can
367 * construct the parameters in INIT ACK by copying the
368 * ERROR causes over.
369 */
370 unk_param = (sctp_unrecognized_param_t *)
371 ((__u8 *)(err_chunk->chunk_hdr) +
372 sizeof(sctp_chunkhdr_t));
373 /* Replace the cause code with the "Unrecognized parameter"
374 * parameter type.
375 */
376 sctp_addto_chunk(repl, len, unk_param);
377 sctp_chunk_free(err_chunk);
378 }
379
380 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
381
382 /*
383 * Note: After sending out INIT ACK with the State Cookie parameter,
384 * "Z" MUST NOT allocate any resources, nor keep any states for the
385 * new association. Otherwise, "Z" will be vulnerable to resource
386 * attacks.
387 */
388 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
389
390 return SCTP_DISPOSITION_DELETE_TCB;
391
392nomem_ack:
393 if (err_chunk)
394 sctp_chunk_free(err_chunk);
395nomem_init:
396 sctp_association_free(new_asoc);
397nomem:
398 return SCTP_DISPOSITION_NOMEM;
399}
400
401/*
402 * Respond to a normal INIT ACK chunk.
403 * We are the side that is initiating the association.
404 *
405 * Section: 5.1 Normal Establishment of an Association, C
406 * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init
407 * timer and leave COOKIE-WAIT state. "A" shall then send the State
408 * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start
409 * the T1-cookie timer, and enter the COOKIE-ECHOED state.
410 *
411 * Note: The COOKIE ECHO chunk can be bundled with any pending outbound
412 * DATA chunks, but it MUST be the first chunk in the packet and
413 * until the COOKIE ACK is returned the sender MUST NOT send any
414 * other packets to the peer.
415 *
416 * Verification Tag: 3.3.3
417 * If the value of the Initiate Tag in a received INIT ACK chunk is
418 * found to be 0, the receiver MUST treat it as an error and close the
419 * association by transmitting an ABORT.
420 *
421 * Inputs
422 * (endpoint, asoc, chunk)
423 *
424 * Outputs
425 * (asoc, reply_msg, msg_up, timers, counters)
426 *
427 * The return value is the disposition of the chunk.
428 */
429sctp_disposition_t sctp_sf_do_5_1C_ack(const struct sctp_endpoint *ep,
430 const struct sctp_association *asoc,
431 const sctp_subtype_t type,
432 void *arg,
433 sctp_cmd_seq_t *commands)
434{
435 struct sctp_chunk *chunk = arg;
436 sctp_init_chunk_t *initchunk;
437 __u32 init_tag;
438 struct sctp_chunk *err_chunk;
439 struct sctp_packet *packet;
440 sctp_disposition_t ret;
441
442 if (!sctp_vtag_verify(chunk, asoc))
443 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
444
445 /* Make sure that the INIT-ACK chunk has a valid length */
446 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_initack_chunk_t)))
447 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
448 commands);
449 /* 6.10 Bundling
450 * An endpoint MUST NOT bundle INIT, INIT ACK or
451 * SHUTDOWN COMPLETE with any other chunks.
452 */
453 if (!chunk->singleton)
454 return SCTP_DISPOSITION_VIOLATION;
455
456 /* Grab the INIT header. */
457 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
458
459 init_tag = ntohl(chunk->subh.init_hdr->init_tag);
460
461 /* Verification Tag: 3.3.3
462 * If the value of the Initiate Tag in a received INIT ACK
463 * chunk is found to be 0, the receiver MUST treat it as an
464 * error and close the association by transmitting an ABORT.
465 */
466 if (!init_tag) {
467 struct sctp_chunk *reply = sctp_make_abort(asoc, chunk, 0);
468 if (!reply)
469 goto nomem;
470
471 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
472 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
473 SCTP_STATE(SCTP_STATE_CLOSED));
474 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
475 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
476 return SCTP_DISPOSITION_DELETE_TCB;
477 }
478
479 /* Verify the INIT chunk before processing it. */
480 err_chunk = NULL;
481 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
482 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
483 &err_chunk)) {
484
485 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
486
487 /* This chunk contains fatal error. It is to be discarded.
488 * Send an ABORT, with causes if there is any.
489 */
490 if (err_chunk) {
491 packet = sctp_abort_pkt_new(ep, asoc, arg,
492 (__u8 *)(err_chunk->chunk_hdr) +
493 sizeof(sctp_chunkhdr_t),
494 ntohs(err_chunk->chunk_hdr->length) -
495 sizeof(sctp_chunkhdr_t));
496
497 sctp_chunk_free(err_chunk);
498
499 if (packet) {
500 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
501 SCTP_PACKET(packet));
502 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
503 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
504 SCTP_STATE(SCTP_STATE_CLOSED));
505 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB,
506 SCTP_NULL());
507 return SCTP_DISPOSITION_CONSUME;
508 } else {
509 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
510 SCTP_STATE(SCTP_STATE_CLOSED));
511 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB,
512 SCTP_NULL());
513 return SCTP_DISPOSITION_NOMEM;
514 }
515 } else {
516 ret = sctp_sf_tabort_8_4_8(ep, asoc, type, arg,
517 commands);
518 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
519 SCTP_STATE(SCTP_STATE_CLOSED));
520 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB,
521 SCTP_NULL());
522 return ret;
523 }
524 }
525
526 /* Tag the variable length parameters. Note that we never
527 * convert the parameters in an INIT chunk.
528 */
529 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
530
531 initchunk = (sctp_init_chunk_t *) chunk->chunk_hdr;
532
533 sctp_add_cmd_sf(commands, SCTP_CMD_PEER_INIT,
534 SCTP_PEER_INIT(initchunk));
535
3f7a87d2
FF		 536 /* Reset init error count upon receipt of INIT-ACK. */
537 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
538
1da177e4
LT		 539 /* 5.1 C) "A" shall stop the T1-init timer and leave
540 * COOKIE-WAIT state. "A" shall then ... start the T1-cookie
541 * timer, and enter the COOKIE-ECHOED state.
542 */
543 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
544 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
545 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
546 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
547 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
548 SCTP_STATE(SCTP_STATE_COOKIE_ECHOED));
549
550 /* 5.1 C) "A" shall then send the State Cookie received in the
551 * INIT ACK chunk in a COOKIE ECHO chunk, ...
552 */
553 /* If there is any errors to report, send the ERROR chunk generated
554 * for unknown parameters as well.
555 */
556 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_COOKIE_ECHO,
557 SCTP_CHUNK(err_chunk));
558
559 return SCTP_DISPOSITION_CONSUME;
560
561nomem:
562 return SCTP_DISPOSITION_NOMEM;
563}
564
565/*
566 * Respond to a normal COOKIE ECHO chunk.
567 * We are the side that is being asked for an association.
568 *
569 * Section: 5.1 Normal Establishment of an Association, D
570 * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply
571 * with a COOKIE ACK chunk after building a TCB and moving to
572 * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with
573 * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK
574 * chunk MUST be the first chunk in the packet.
575 *
576 * IMPLEMENTATION NOTE: An implementation may choose to send the
577 * Communication Up notification to the SCTP user upon reception
578 * of a valid COOKIE ECHO chunk.
579 *
580 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
581 * D) Rules for packet carrying a COOKIE ECHO
582 *
583 * - When sending a COOKIE ECHO, the endpoint MUST use the value of the
584 * Initial Tag received in the INIT ACK.
585 *
586 * - The receiver of a COOKIE ECHO follows the procedures in Section 5.
587 *
588 * Inputs
589 * (endpoint, asoc, chunk)
590 *
591 * Outputs
592 * (asoc, reply_msg, msg_up, timers, counters)
593 *
594 * The return value is the disposition of the chunk.
595 */
596sctp_disposition_t sctp_sf_do_5_1D_ce(const struct sctp_endpoint *ep,
597 const struct sctp_association *asoc,
598 const sctp_subtype_t type, void *arg,
599 sctp_cmd_seq_t *commands)
600{
601 struct sctp_chunk *chunk = arg;
602 struct sctp_association *new_asoc;
603 sctp_init_chunk_t *peer_init;
604 struct sctp_chunk *repl;
605 struct sctp_ulpevent *ev;
606 int error = 0;
607 struct sctp_chunk *err_chk_p;
608
609 /* If the packet is an OOTB packet which is temporarily on the
610 * control endpoint, respond with an ABORT.
611 */
612 if (ep == sctp_sk((sctp_get_ctl_sock()))->ep)
613 return sctp_sf_ootb(ep, asoc, type, arg, commands);
614
615 /* Make sure that the COOKIE_ECHO chunk has a valid length.
616 * In this case, we check that we have enough for at least a
617 * chunk header. More detailed verification is done
618 * in sctp_unpack_cookie().
619 */
620 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
621 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
622
623 /* "Decode" the chunk. We have no optional parameters so we
624 * are in good shape.
625 */
626 chunk->subh.cookie_hdr =
627 (struct sctp_signed_cookie *)chunk->skb->data;
628 skb_pull(chunk->skb,
629 ntohs(chunk->chunk_hdr->length) - sizeof(sctp_chunkhdr_t));
630
631 /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
632 * "Z" will reply with a COOKIE ACK chunk after building a TCB
633 * and moving to the ESTABLISHED state.
634 */
635 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
636 &err_chk_p);
637
638 /* FIXME:
639 * If the re-build failed, what is the proper error path
640 * from here?
641 *
642 * [We should abort the association. --piggy]
643 */
644 if (!new_asoc) {
645 /* FIXME: Several errors are possible. A bad cookie should
646 * be silently discarded, but think about logging it too.
647 */
648 switch (error) {
649 case -SCTP_IERROR_NOMEM:
650 goto nomem;
651
652 case -SCTP_IERROR_STALE_COOKIE:
653 sctp_send_stale_cookie_err(ep, asoc, chunk, commands,
654 err_chk_p);
655 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
656
657 case -SCTP_IERROR_BAD_SIG:
658 default:
659 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
660 };
661 }
662
663 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
664 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
665 SCTP_STATE(SCTP_STATE_ESTABLISHED));
666 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
667 SCTP_INC_STATS(SCTP_MIB_PASSIVEESTABS);
668 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
669
670 if (new_asoc->autoclose)
671 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
672 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
673
674 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
675
676 /* Re-build the bind address for the association is done in
677 * the sctp_unpack_cookie() already.
678 */
679 /* This is a brand-new association, so these are not yet side
680 * effects--it is safe to run them here.
681 */
682 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
683
684 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
685 &chunk->subh.cookie_hdr->c.peer_addr,
686 peer_init, GFP_ATOMIC))
687 goto nomem_init;
688
689 repl = sctp_make_cookie_ack(new_asoc, chunk);
690 if (!repl)
691 goto nomem_repl;
692
693 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
694
695 /* RFC 2960 5.1 Normal Establishment of an Association
696 *
697 * D) IMPLEMENTATION NOTE: An implementation may choose to
698 * send the Communication Up notification to the SCTP user
699 * upon reception of a valid COOKIE ECHO chunk.
700 */
701 ev = sctp_ulpevent_make_assoc_change(new_asoc, 0, SCTP_COMM_UP, 0,
702 new_asoc->c.sinit_num_ostreams,
703 new_asoc->c.sinit_max_instreams,
704 GFP_ATOMIC);
705 if (!ev)
706 goto nomem_ev;
707
708 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
709
710 /* Sockets API Draft Section 5.3.1.6
711 * When a peer sends a Adaption Layer Indication parameter , SCTP
712 * delivers this notification to inform the application that of the
713 * peers requested adaption layer.
714 */
715 if (new_asoc->peer.adaption_ind) {
716 ev = sctp_ulpevent_make_adaption_indication(new_asoc,
717 GFP_ATOMIC);
718 if (!ev)
719 goto nomem_ev;
720
721 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
722 SCTP_ULPEVENT(ev));
723 }
724
725 return SCTP_DISPOSITION_CONSUME;
726
727nomem_ev:
728 sctp_chunk_free(repl);
729nomem_repl:
730nomem_init:
731 sctp_association_free(new_asoc);
732nomem:
733 return SCTP_DISPOSITION_NOMEM;
734}
735
736/*
737 * Respond to a normal COOKIE ACK chunk.
738 * We are the side that is being asked for an association.
739 *
740 * RFC 2960 5.1 Normal Establishment of an Association
741 *
742 * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the
743 * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie
744 * timer. It may also notify its ULP about the successful
745 * establishment of the association with a Communication Up
746 * notification (see Section 10).
747 *
748 * Verification Tag:
749 * Inputs
750 * (endpoint, asoc, chunk)
751 *
752 * Outputs
753 * (asoc, reply_msg, msg_up, timers, counters)
754 *
755 * The return value is the disposition of the chunk.
756 */
757sctp_disposition_t sctp_sf_do_5_1E_ca(const struct sctp_endpoint *ep,
758 const struct sctp_association *asoc,
759 const sctp_subtype_t type, void *arg,
760 sctp_cmd_seq_t *commands)
761{
762 struct sctp_chunk *chunk = arg;
763 struct sctp_ulpevent *ev;
764
765 if (!sctp_vtag_verify(chunk, asoc))
766 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
767
768 /* Verify that the chunk length for the COOKIE-ACK is OK.
769 * If we don't do this, any bundled chunks may be junked.
770 */
771 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
772 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
773 commands);
774
775 /* Reset init error count upon receipt of COOKIE-ACK,
776 * to avoid problems with the managemement of this
777 * counter in stale cookie situations when a transition back
778 * from the COOKIE-ECHOED state to the COOKIE-WAIT
779 * state is performed.
780 */
3f7a87d2 781 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
1da177e4
LT		 782
783 /* RFC 2960 5.1 Normal Establishment of an Association
784 *
785 * E) Upon reception of the COOKIE ACK, endpoint "A" will move
786 * from the COOKIE-ECHOED state to the ESTABLISHED state,
787 * stopping the T1-cookie timer.
788 */
789 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
790 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
791 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
792 SCTP_STATE(SCTP_STATE_ESTABLISHED));
793 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
794 SCTP_INC_STATS(SCTP_MIB_ACTIVEESTABS);
795 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
796 if (asoc->autoclose)
797 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
798 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
799 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
800
801 /* It may also notify its ULP about the successful
802 * establishment of the association with a Communication Up
803 * notification (see Section 10).
804 */
805 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP,
806 0, asoc->c.sinit_num_ostreams,
807 asoc->c.sinit_max_instreams,
808 GFP_ATOMIC);
809
810 if (!ev)
811 goto nomem;
812
813 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
814
815 /* Sockets API Draft Section 5.3.1.6
816 * When a peer sends a Adaption Layer Indication parameter , SCTP
817 * delivers this notification to inform the application that of the
818 * peers requested adaption layer.
819 */
820 if (asoc->peer.adaption_ind) {
821 ev = sctp_ulpevent_make_adaption_indication(asoc, GFP_ATOMIC);
822 if (!ev)
823 goto nomem;
824
825 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
826 SCTP_ULPEVENT(ev));
827 }
828
829 return SCTP_DISPOSITION_CONSUME;
830nomem:
831 return SCTP_DISPOSITION_NOMEM;
832}
833
834/* Generate and sendout a heartbeat packet. */
835static sctp_disposition_t sctp_sf_heartbeat(const struct sctp_endpoint *ep,
836 const struct sctp_association *asoc,
837 const sctp_subtype_t type,
838 void *arg,
839 sctp_cmd_seq_t *commands)
840{
841 struct sctp_transport *transport = (struct sctp_transport *) arg;
842 struct sctp_chunk *reply;
843 sctp_sender_hb_info_t hbinfo;
844 size_t paylen = 0;
845
846 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO;
847 hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t));
848 hbinfo.daddr = transport->ipaddr;
849 hbinfo.sent_at = jiffies;
850
851 /* Send a heartbeat to our peer. */
852 paylen = sizeof(sctp_sender_hb_info_t);
853 reply = sctp_make_heartbeat(asoc, transport, &hbinfo, paylen);
854 if (!reply)
855 return SCTP_DISPOSITION_NOMEM;
856
857 /* Set rto_pending indicating that an RTT measurement
858 * is started with this heartbeat chunk.
859 */
860 sctp_add_cmd_sf(commands, SCTP_CMD_RTO_PENDING,
861 SCTP_TRANSPORT(transport));
862
863 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
864 return SCTP_DISPOSITION_CONSUME;
865}
866
867/* Generate a HEARTBEAT packet on the given transport. */
868sctp_disposition_t sctp_sf_sendbeat_8_3(const struct sctp_endpoint *ep,
869 const struct sctp_association *asoc,
870 const sctp_subtype_t type,
871 void *arg,
872 sctp_cmd_seq_t *commands)
873{
874 struct sctp_transport *transport = (struct sctp_transport *) arg;
875
876 if (asoc->overall_error_count > asoc->max_retrans) {
877 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
878 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
879 SCTP_U32(SCTP_ERROR_NO_ERROR));
880 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
881 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
882 return SCTP_DISPOSITION_DELETE_TCB;
883 }
884
885 /* Section 3.3.5.
886 * The Sender-specific Heartbeat Info field should normally include
887 * information about the sender's current time when this HEARTBEAT
888 * chunk is sent and the destination transport address to which this
889 * HEARTBEAT is sent (see Section 8.3).
890 */
891
892 if (transport->hb_allowed) {
893 if (SCTP_DISPOSITION_NOMEM ==
894 sctp_sf_heartbeat(ep, asoc, type, arg,
895 commands))
896 return SCTP_DISPOSITION_NOMEM;
897 /* Set transport error counter and association error counter
898 * when sending heartbeat.
899 */
900 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_RESET,
901 SCTP_TRANSPORT(transport));
902 }
903 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMER_UPDATE,
904 SCTP_TRANSPORT(transport));
905
906 return SCTP_DISPOSITION_CONSUME;
907}
908
909/*
910 * Process an heartbeat request.
911 *
912 * Section: 8.3 Path Heartbeat
913 * The receiver of the HEARTBEAT should immediately respond with a
914 * HEARTBEAT ACK that contains the Heartbeat Information field copied
915 * from the received HEARTBEAT chunk.
916 *
917 * Verification Tag: 8.5 Verification Tag [Normal verification]
918 * When receiving an SCTP packet, the endpoint MUST ensure that the
919 * value in the Verification Tag field of the received SCTP packet
920 * matches its own Tag. If the received Verification Tag value does not
921 * match the receiver's own tag value, the receiver shall silently
922 * discard the packet and shall not process it any further except for
923 * those cases listed in Section 8.5.1 below.
924 *
925 * Inputs
926 * (endpoint, asoc, chunk)
927 *
928 * Outputs
929 * (asoc, reply_msg, msg_up, timers, counters)
930 *
931 * The return value is the disposition of the chunk.
932 */
933sctp_disposition_t sctp_sf_beat_8_3(const struct sctp_endpoint *ep,
934 const struct sctp_association *asoc,
935 const sctp_subtype_t type,
936 void *arg,
937 sctp_cmd_seq_t *commands)
938{
939 struct sctp_chunk *chunk = arg;
940 struct sctp_chunk *reply;
941 size_t paylen = 0;
942
943 if (!sctp_vtag_verify(chunk, asoc))
944 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
945
946 /* Make sure that the HEARTBEAT chunk has a valid length. */
947 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t)))
948 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
949 commands);
950
951 /* 8.3 The receiver of the HEARTBEAT should immediately
952 * respond with a HEARTBEAT ACK that contains the Heartbeat
953 * Information field copied from the received HEARTBEAT chunk.
954 */
955 chunk->subh.hb_hdr = (sctp_heartbeathdr_t *) chunk->skb->data;
956 paylen = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
957 skb_pull(chunk->skb, paylen);
958
959 reply = sctp_make_heartbeat_ack(asoc, chunk,
960 chunk->subh.hb_hdr, paylen);
961 if (!reply)
962 goto nomem;
963
964 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
965 return SCTP_DISPOSITION_CONSUME;
966
967nomem:
968 return SCTP_DISPOSITION_NOMEM;
969}
970
971/*
972 * Process the returning HEARTBEAT ACK.
973 *
974 * Section: 8.3 Path Heartbeat
975 * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT
976 * should clear the error counter of the destination transport
977 * address to which the HEARTBEAT was sent, and mark the destination
978 * transport address as active if it is not so marked. The endpoint may
979 * optionally report to the upper layer when an inactive destination
980 * address is marked as active due to the reception of the latest
981 * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also
982 * clear the association overall error count as well (as defined
983 * in section 8.1).
984 *
985 * The receiver of the HEARTBEAT ACK should also perform an RTT
986 * measurement for that destination transport address using the time
987 * value carried in the HEARTBEAT ACK chunk.
988 *
989 * Verification Tag: 8.5 Verification Tag [Normal verification]
990 *
991 * Inputs
992 * (endpoint, asoc, chunk)
993 *
994 * Outputs
995 * (asoc, reply_msg, msg_up, timers, counters)
996 *
997 * The return value is the disposition of the chunk.
998 */
999sctp_disposition_t sctp_sf_backbeat_8_3(const struct sctp_endpoint *ep,
1000 const struct sctp_association *asoc,
1001 const sctp_subtype_t type,
1002 void *arg,
1003 sctp_cmd_seq_t *commands)
1004{
1005 struct sctp_chunk *chunk = arg;
1006 union sctp_addr from_addr;
1007 struct sctp_transport *link;
1008 sctp_sender_hb_info_t *hbinfo;
1009 unsigned long max_interval;
1010
1011 if (!sctp_vtag_verify(chunk, asoc))
1012 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1013
1014 /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */
1015 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t)))
1016 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1017 commands);
1018
1019 hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
1020 from_addr = hbinfo->daddr;
1021 link = sctp_assoc_lookup_paddr(asoc, &from_addr);
1022
1023 /* This should never happen, but lets log it if so. */
3f7a87d2
FF		 1024 if (unlikely(!link)) {
1025 if (from_addr.sa.sa_family == AF_INET6) {
1026 printk(KERN_WARNING
1027 "%s association %p could not find address "
1028 "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
1029 __FUNCTION__,
1030 asoc,
1031 NIP6(from_addr.v6.sin6_addr));
1032 } else {
1033 printk(KERN_WARNING
1034 "%s association %p could not find address "
1035 "%u.%u.%u.%u\n",
1036 __FUNCTION__,
1037 asoc,
1038 NIPQUAD(from_addr.v4.sin_addr.s_addr));
1039 }
1da177e4
LT		 1040 return SCTP_DISPOSITION_DISCARD;
1041 }
1042
1043 max_interval = link->hb_interval + link->rto;
1044
1045 /* Check if the timestamp looks valid. */
1046 if (time_after(hbinfo->sent_at, jiffies) ||
1047 time_after(jiffies, hbinfo->sent_at + max_interval)) {
1048 SCTP_DEBUG_PRINTK("%s: HEARTBEAT ACK with invalid timestamp"
1049 "received for transport: %p\n",
1050 __FUNCTION__, link);
1051 return SCTP_DISPOSITION_DISCARD;
1052 }
1053
1054 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of
1055 * the HEARTBEAT should clear the error counter of the
1056 * destination transport address to which the HEARTBEAT was
1057 * sent and mark the destination transport address as active if
1058 * it is not so marked.
1059 */
1060 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_ON, SCTP_TRANSPORT(link));
1061
1062 return SCTP_DISPOSITION_CONSUME;
1063}
1064
1065/* Helper function to send out an abort for the restart
1066 * condition.
1067 */
1068static int sctp_sf_send_restart_abort(union sctp_addr *ssa,
1069 struct sctp_chunk *init,
1070 sctp_cmd_seq_t *commands)
1071{
1072 int len;
1073 struct sctp_packet *pkt;
1074 union sctp_addr_param *addrparm;
1075 struct sctp_errhdr *errhdr;
1076 struct sctp_endpoint *ep;
1077 char buffer[sizeof(struct sctp_errhdr)+sizeof(union sctp_addr_param)];
1078 struct sctp_af *af = sctp_get_af_specific(ssa->v4.sin_family);
1079
1080 /* Build the error on the stack. We are way to malloc crazy
1081 * throughout the code today.
1082 */
1083 errhdr = (struct sctp_errhdr *)buffer;
1084 addrparm = (union sctp_addr_param *)errhdr->variable;
1085
1086 /* Copy into a parm format. */
1087 len = af->to_addr_param(ssa, addrparm);
1088 len += sizeof(sctp_errhdr_t);
1089
1090 errhdr->cause = SCTP_ERROR_RESTART;
1091 errhdr->length = htons(len);
1092
1093 /* Assign to the control socket. */
1094 ep = sctp_sk((sctp_get_ctl_sock()))->ep;
1095
1096 /* Association is NULL since this may be a restart attack and we
1097 * want to send back the attacker's vtag.
1098 */
1099 pkt = sctp_abort_pkt_new(ep, NULL, init, errhdr, len);
1100
1101 if (!pkt)
1102 goto out;
1103 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, SCTP_PACKET(pkt));
1104
1105 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
1106
1107 /* Discard the rest of the inbound packet. */
1108 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
1109
1110out:
1111 /* Even if there is no memory, treat as a failure so
1112 * the packet will get dropped.
1113 */
1114 return 0;
1115}
1116
1117/* A restart is occurring, check to make sure no new addresses
1118 * are being added as we may be under a takeover attack.
1119 */
1120static int sctp_sf_check_restart_addrs(const struct sctp_association *new_asoc,
1121 const struct sctp_association *asoc,
1122 struct sctp_chunk *init,
1123 sctp_cmd_seq_t *commands)
1124{
1125 struct sctp_transport *new_addr, *addr;
1126 struct list_head *pos, *pos2;
1127 int found;
1128
1129 /* Implementor's Guide - Sectin 5.2.2
1130 * ...
1131 * Before responding the endpoint MUST check to see if the
1132 * unexpected INIT adds new addresses to the association. If new
1133 * addresses are added to the association, the endpoint MUST respond
1134 * with an ABORT..
1135 */
1136
1137 /* Search through all current addresses and make sure
1138 * we aren't adding any new ones.
1139 */
1140 new_addr = NULL;
1141 found = 0;
1142
1143 list_for_each(pos, &new_asoc->peer.transport_addr_list) {
1144 new_addr = list_entry(pos, struct sctp_transport, transports);
1145 found = 0;
1146 list_for_each(pos2, &asoc->peer.transport_addr_list) {
1147 addr = list_entry(pos2, struct sctp_transport,
1148 transports);
1149 if (sctp_cmp_addr_exact(&new_addr->ipaddr,
1150 &addr->ipaddr)) {
1151 found = 1;
1152 break;
1153 }
1154 }
1155 if (!found)
1156 break;
1157 }
1158
1159 /* If a new address was added, ABORT the sender. */
1160 if (!found && new_addr) {
1161 sctp_sf_send_restart_abort(&new_addr->ipaddr, init, commands);
1162 }
1163
1164 /* Return success if all addresses were found. */
1165 return found;
1166}
1167
1168/* Populate the verification/tie tags based on overlapping INIT
1169 * scenario.
1170 *
1171 * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state.
1172 */
1173static void sctp_tietags_populate(struct sctp_association *new_asoc,
1174 const struct sctp_association *asoc)
1175{
1176 switch (asoc->state) {
1177
1178 /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */
1179
1180 case SCTP_STATE_COOKIE_WAIT:
1181 new_asoc->c.my_vtag = asoc->c.my_vtag;
1182 new_asoc->c.my_ttag = asoc->c.my_vtag;
1183 new_asoc->c.peer_ttag = 0;
1184 break;
1185
1186 case SCTP_STATE_COOKIE_ECHOED:
1187 new_asoc->c.my_vtag = asoc->c.my_vtag;
1188 new_asoc->c.my_ttag = asoc->c.my_vtag;
1189 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1190 break;
1191
1192 /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED,
1193 * COOKIE-WAIT and SHUTDOWN-ACK-SENT
1194 */
1195 default:
1196 new_asoc->c.my_ttag = asoc->c.my_vtag;
1197 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1198 break;
1199 };
1200
1201 /* Other parameters for the endpoint SHOULD be copied from the
1202 * existing parameters of the association (e.g. number of
1203 * outbound streams) into the INIT ACK and cookie.
1204 */
1205 new_asoc->rwnd = asoc->rwnd;
1206 new_asoc->c.sinit_num_ostreams = asoc->c.sinit_num_ostreams;
1207 new_asoc->c.sinit_max_instreams = asoc->c.sinit_max_instreams;
1208 new_asoc->c.initial_tsn = asoc->c.initial_tsn;
1209}
1210
1211/*
1212 * Compare vtag/tietag values to determine unexpected COOKIE-ECHO
1213 * handling action.
1214 *
1215 * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists.
1216 *
1217 * Returns value representing action to be taken. These action values
1218 * correspond to Action/Description values in RFC 2960, Table 2.
1219 */
1220static char sctp_tietags_compare(struct sctp_association *new_asoc,
1221 const struct sctp_association *asoc)
1222{
1223 /* In this case, the peer may have restarted. */
1224 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1225 (asoc->c.peer_vtag != new_asoc->c.peer_vtag) &&
1226 (asoc->c.my_vtag == new_asoc->c.my_ttag) &&
1227 (asoc->c.peer_vtag == new_asoc->c.peer_ttag))
1228 return 'A';
1229
1230 /* Collision case B. */
1231 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1232 ((asoc->c.peer_vtag != new_asoc->c.peer_vtag) ||
1233 (0 == asoc->c.peer_vtag))) {
1234 return 'B';
1235 }
1236
1237 /* Collision case D. */
1238 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1239 (asoc->c.peer_vtag == new_asoc->c.peer_vtag))
1240 return 'D';
1241
1242 /* Collision case C. */
1243 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1244 (asoc->c.peer_vtag == new_asoc->c.peer_vtag) &&
1245 (0 == new_asoc->c.my_ttag) &&
1246 (0 == new_asoc->c.peer_ttag))
1247 return 'C';
1248
1249 /* No match to any of the special cases; discard this packet. */
1250 return 'E';
1251}
1252
1253/* Common helper routine for both duplicate and simulataneous INIT
1254 * chunk handling.
1255 */
1256static sctp_disposition_t sctp_sf_do_unexpected_init(
1257 const struct sctp_endpoint *ep,
1258 const struct sctp_association *asoc,
1259 const sctp_subtype_t type,
1260 void *arg, sctp_cmd_seq_t *commands)
1261{
1262 sctp_disposition_t retval;
1263 struct sctp_chunk *chunk = arg;
1264 struct sctp_chunk *repl;
1265 struct sctp_association *new_asoc;
1266 struct sctp_chunk *err_chunk;
1267 struct sctp_packet *packet;
1268 sctp_unrecognized_param_t *unk_param;
1269 int len;
1270
1271 /* 6.10 Bundling
1272 * An endpoint MUST NOT bundle INIT, INIT ACK or
1273 * SHUTDOWN COMPLETE with any other chunks.
1274 *
1275 * IG Section 2.11.2
1276 * Furthermore, we require that the receiver of an INIT chunk MUST
1277 * enforce these rules by silently discarding an arriving packet
1278 * with an INIT chunk that is bundled with other chunks.
1279 */
1280 if (!chunk->singleton)
1281 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1282
1283 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
1284 * Tag.
1285 */
1286 if (chunk->sctp_hdr->vtag != 0)
1287 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
1288
1289 /* Make sure that the INIT chunk has a valid length.
1290 * In this case, we generate a protocol violation since we have
1291 * an association established.
1292 */
1293 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
1294 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1295 commands);
1296 /* Grab the INIT header. */
1297 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
1298
1299 /* Tag the variable length parameters. */
1300 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
1301
1302 /* Verify the INIT chunk before processing it. */
1303 err_chunk = NULL;
1304 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
1305 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
1306 &err_chunk)) {
1307 /* This chunk contains fatal error. It is to be discarded.
1308 * Send an ABORT, with causes if there is any.
1309 */
1310 if (err_chunk) {
1311 packet = sctp_abort_pkt_new(ep, asoc, arg,
1312 (__u8 *)(err_chunk->chunk_hdr) +
1313 sizeof(sctp_chunkhdr_t),
1314 ntohs(err_chunk->chunk_hdr->length) -
1315 sizeof(sctp_chunkhdr_t));
1316
1317 if (packet) {
1318 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
1319 SCTP_PACKET(packet));
1320 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
1321 retval = SCTP_DISPOSITION_CONSUME;
1322 } else {
1323 retval = SCTP_DISPOSITION_NOMEM;
1324 }
1325 goto cleanup;
1326 } else {
1327 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg,
1328 commands);
1329 }
1330 }
1331
1332 /*
1333 * Other parameters for the endpoint SHOULD be copied from the
1334 * existing parameters of the association (e.g. number of
1335 * outbound streams) into the INIT ACK and cookie.
1336 * FIXME: We are copying parameters from the endpoint not the
1337 * association.
1338 */
1339 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
1340 if (!new_asoc)
1341 goto nomem;
1342
1343 /* In the outbound INIT ACK the endpoint MUST copy its current
1344 * Verification Tag and Peers Verification tag into a reserved
1345 * place (local tie-tag and per tie-tag) within the state cookie.
1346 */
1347 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
1348 sctp_source(chunk),
1349 (sctp_init_chunk_t *)chunk->chunk_hdr,
1350 GFP_ATOMIC)) {
1351 retval = SCTP_DISPOSITION_NOMEM;
1352 goto nomem_init;
1353 }
1354
1355 /* Make sure no new addresses are being added during the
1356 * restart. Do not do this check for COOKIE-WAIT state,
1357 * since there are no peer addresses to check against.
1358 * Upon return an ABORT will have been sent if needed.
1359 */
1360 if (!sctp_state(asoc, COOKIE_WAIT)) {
1361 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk,
1362 commands)) {
1363 retval = SCTP_DISPOSITION_CONSUME;
1364 goto cleanup_asoc;
1365 }
1366 }
1367
1368 sctp_tietags_populate(new_asoc, asoc);
1369
1370 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
1371
1372 /* If there are errors need to be reported for unknown parameters,
1373 * make sure to reserve enough room in the INIT ACK for them.
1374 */
1375 len = 0;
1376 if (err_chunk) {
1377 len = ntohs(err_chunk->chunk_hdr->length) -
1378 sizeof(sctp_chunkhdr_t);
1379 }
1380
1381 if (sctp_assoc_set_bind_addr_from_ep(new_asoc, GFP_ATOMIC) < 0)
1382 goto nomem;
1383
1384 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
1385 if (!repl)
1386 goto nomem;
1387
1388 /* If there are errors need to be reported for unknown parameters,
1389 * include them in the outgoing INIT ACK as "Unrecognized parameter"
1390 * parameter.
1391 */
1392 if (err_chunk) {
1393 /* Get the "Unrecognized parameter" parameter(s) out of the
1394 * ERROR chunk generated by sctp_verify_init(). Since the
1395 * error cause code for "unknown parameter" and the
1396 * "Unrecognized parameter" type is the same, we can
1397 * construct the parameters in INIT ACK by copying the
1398 * ERROR causes over.
1399 */
1400 unk_param = (sctp_unrecognized_param_t *)
1401 ((__u8 *)(err_chunk->chunk_hdr) +
1402 sizeof(sctp_chunkhdr_t));
1403 /* Replace the cause code with the "Unrecognized parameter"
1404 * parameter type.
1405 */
1406 sctp_addto_chunk(repl, len, unk_param);
1407 }
1408
1409 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
1410 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1411
1412 /*
1413 * Note: After sending out INIT ACK with the State Cookie parameter,
1414 * "Z" MUST NOT allocate any resources for this new association.
1415 * Otherwise, "Z" will be vulnerable to resource attacks.
1416 */
1417 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
1418 retval = SCTP_DISPOSITION_CONSUME;
1419
1420cleanup:
1421 if (err_chunk)
1422 sctp_chunk_free(err_chunk);
1423 return retval;
1424nomem:
1425 retval = SCTP_DISPOSITION_NOMEM;
1426 goto cleanup;
1427nomem_init:
1428cleanup_asoc:
1429 sctp_association_free(new_asoc);
1430 goto cleanup;
1431}
1432
1433/*
1434 * Handle simultanous INIT.
1435 * This means we started an INIT and then we got an INIT request from
1436 * our peer.
1437 *
1438 * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B)
1439 * This usually indicates an initialization collision, i.e., each
1440 * endpoint is attempting, at about the same time, to establish an
1441 * association with the other endpoint.
1442 *
1443 * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an
1444 * endpoint MUST respond with an INIT ACK using the same parameters it
1445 * sent in its original INIT chunk (including its Verification Tag,
1446 * unchanged). These original parameters are combined with those from the
1447 * newly received INIT chunk. The endpoint shall also generate a State
1448 * Cookie with the INIT ACK. The endpoint uses the parameters sent in its
1449 * INIT to calculate the State Cookie.
1450 *
1451 * After that, the endpoint MUST NOT change its state, the T1-init
1452 * timer shall be left running and the corresponding TCB MUST NOT be
1453 * destroyed. The normal procedures for handling State Cookies when
1454 * a TCB exists will resolve the duplicate INITs to a single association.
1455 *
1456 * For an endpoint that is in the COOKIE-ECHOED state it MUST populate
1457 * its Tie-Tags with the Tag information of itself and its peer (see
1458 * section 5.2.2 for a description of the Tie-Tags).
1459 *
1460 * Verification Tag: Not explicit, but an INIT can not have a valid
1461 * verification tag, so we skip the check.
1462 *
1463 * Inputs
1464 * (endpoint, asoc, chunk)
1465 *
1466 * Outputs
1467 * (asoc, reply_msg, msg_up, timers, counters)
1468 *
1469 * The return value is the disposition of the chunk.
1470 */
1471sctp_disposition_t sctp_sf_do_5_2_1_siminit(const struct sctp_endpoint *ep,
1472 const struct sctp_association *asoc,
1473 const sctp_subtype_t type,
1474 void *arg,
1475 sctp_cmd_seq_t *commands)
1476{
1477 /* Call helper to do the real work for both simulataneous and
1478 * duplicate INIT chunk handling.
1479 */
1480 return sctp_sf_do_unexpected_init(ep, asoc, type, arg, commands);
1481}
1482
1483/*
1484 * Handle duplicated INIT messages. These are usually delayed
1485 * restransmissions.
1486 *
1487 * Section: 5.2.2 Unexpected INIT in States Other than CLOSED,
1488 * COOKIE-ECHOED and COOKIE-WAIT
1489 *
1490 * Unless otherwise stated, upon reception of an unexpected INIT for
1491 * this association, the endpoint shall generate an INIT ACK with a
1492 * State Cookie. In the outbound INIT ACK the endpoint MUST copy its
1493 * current Verification Tag and peer's Verification Tag into a reserved
1494 * place within the state cookie. We shall refer to these locations as
1495 * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet
1496 * containing this INIT ACK MUST carry a Verification Tag value equal to
1497 * the Initiation Tag found in the unexpected INIT. And the INIT ACK
1498 * MUST contain a new Initiation Tag (randomly generated see Section
1499 * 5.3.1). Other parameters for the endpoint SHOULD be copied from the
1500 * existing parameters of the association (e.g. number of outbound
1501 * streams) into the INIT ACK and cookie.
1502 *
1503 * After sending out the INIT ACK, the endpoint shall take no further
1504 * actions, i.e., the existing association, including its current state,
1505 * and the corresponding TCB MUST NOT be changed.
1506 *
1507 * Note: Only when a TCB exists and the association is not in a COOKIE-
1508 * WAIT state are the Tie-Tags populated. For a normal association INIT
1509 * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be
1510 * set to 0 (indicating that no previous TCB existed). The INIT ACK and
1511 * State Cookie are populated as specified in section 5.2.1.
1512 *
1513 * Verification Tag: Not specified, but an INIT has no way of knowing
1514 * what the verification tag could be, so we ignore it.
1515 *
1516 * Inputs
1517 * (endpoint, asoc, chunk)
1518 *
1519 * Outputs
1520 * (asoc, reply_msg, msg_up, timers, counters)
1521 *
1522 * The return value is the disposition of the chunk.
1523 */
1524sctp_disposition_t sctp_sf_do_5_2_2_dupinit(const struct sctp_endpoint *ep,
1525 const struct sctp_association *asoc,
1526 const sctp_subtype_t type,
1527 void *arg,
1528 sctp_cmd_seq_t *commands)
1529{
1530 /* Call helper to do the real work for both simulataneous and
1531 * duplicate INIT chunk handling.
1532 */
1533 return sctp_sf_do_unexpected_init(ep, asoc, type, arg, commands);
1534}
1535
1536
1537
1538/* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A')
1539 *
1540 * Section 5.2.4
1541 * A) In this case, the peer may have restarted.
1542 */
1543static sctp_disposition_t sctp_sf_do_dupcook_a(const struct sctp_endpoint *ep,
1544 const struct sctp_association *asoc,
1545 struct sctp_chunk *chunk,
1546 sctp_cmd_seq_t *commands,
1547 struct sctp_association *new_asoc)
1548{
1549 sctp_init_chunk_t *peer_init;
1550 struct sctp_ulpevent *ev;
1551 struct sctp_chunk *repl;
1552 struct sctp_chunk *err;
1553 sctp_disposition_t disposition;
1554
1555 /* new_asoc is a brand-new association, so these are not yet
1556 * side effects--it is safe to run them here.
1557 */
1558 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1559
1560 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
1561 sctp_source(chunk), peer_init,
1562 GFP_ATOMIC))
1563 goto nomem;
1564
1565 /* Make sure no new addresses are being added during the
1566 * restart. Though this is a pretty complicated attack
1567 * since you'd have to get inside the cookie.
1568 */
1569 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk, commands)) {
1570 return SCTP_DISPOSITION_CONSUME;
1571 }
1572
1573 /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes
1574 * the peer has restarted (Action A), it MUST NOT setup a new
1575 * association but instead resend the SHUTDOWN ACK and send an ERROR
1576 * chunk with a "Cookie Received while Shutting Down" error cause to
1577 * its peer.
1578 */
1579 if (sctp_state(asoc, SHUTDOWN_ACK_SENT)) {
1580 disposition = sctp_sf_do_9_2_reshutack(ep, asoc,
1581 SCTP_ST_CHUNK(chunk->chunk_hdr->type),
1582 chunk, commands);
1583 if (SCTP_DISPOSITION_NOMEM == disposition)
1584 goto nomem;
1585
1586 err = sctp_make_op_error(asoc, chunk,
1587 SCTP_ERROR_COOKIE_IN_SHUTDOWN,
1588 NULL, 0);
1589 if (err)
1590 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1591 SCTP_CHUNK(err));
1592
1593 return SCTP_DISPOSITION_CONSUME;
1594 }
1595
1596 /* For now, fail any unsent/unacked data. Consider the optional
1597 * choice of resending of this data.
1598 */
1599 sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_OUTQUEUE, SCTP_NULL());
1600
1601 /* Update the content of current association. */
1602 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1603
1604 repl = sctp_make_cookie_ack(new_asoc, chunk);
1605 if (!repl)
1606 goto nomem;
1607
1608 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1609
1610 /* Report association restart to upper layer. */
1611 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_RESTART, 0,
1612 new_asoc->c.sinit_num_ostreams,
1613 new_asoc->c.sinit_max_instreams,
1614 GFP_ATOMIC);
1615 if (!ev)
1616 goto nomem_ev;
1617
1618 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
1619 return SCTP_DISPOSITION_CONSUME;
1620
1621nomem_ev:
1622 sctp_chunk_free(repl);
1623nomem:
1624 return SCTP_DISPOSITION_NOMEM;
1625}
1626
1627/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B')
1628 *
1629 * Section 5.2.4
1630 * B) In this case, both sides may be attempting to start an association
1631 * at about the same time but the peer endpoint started its INIT
1632 * after responding to the local endpoint's INIT
1633 */
1634/* This case represents an initialization collision. */
1635static sctp_disposition_t sctp_sf_do_dupcook_b(const struct sctp_endpoint *ep,
1636 const struct sctp_association *asoc,
1637 struct sctp_chunk *chunk,
1638 sctp_cmd_seq_t *commands,
1639 struct sctp_association *new_asoc)
1640{
1641 sctp_init_chunk_t *peer_init;
1642 struct sctp_ulpevent *ev;
1643 struct sctp_chunk *repl;
1644
1645 /* new_asoc is a brand-new association, so these are not yet
1646 * side effects--it is safe to run them here.
1647 */
1648 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1649 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
1650 sctp_source(chunk), peer_init,
1651 GFP_ATOMIC))
1652 goto nomem;
1653
1654 /* Update the content of current association. */
1655 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1656 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1657 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1658 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
1659 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
1660
1661 repl = sctp_make_cookie_ack(new_asoc, chunk);
1662 if (!repl)
1663 goto nomem;
1664
1665 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1666 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
1667
1668 /* RFC 2960 5.1 Normal Establishment of an Association
1669 *
1670 * D) IMPLEMENTATION NOTE: An implementation may choose to
1671 * send the Communication Up notification to the SCTP user
1672 * upon reception of a valid COOKIE ECHO chunk.
1673 */
1674 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP, 0,
1675 new_asoc->c.sinit_num_ostreams,
1676 new_asoc->c.sinit_max_instreams,
1677 GFP_ATOMIC);
1678 if (!ev)
1679 goto nomem_ev;
1680
1681 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
1682
1683 /* Sockets API Draft Section 5.3.1.6
1684 * When a peer sends a Adaption Layer Indication parameter , SCTP
1685 * delivers this notification to inform the application that of the
1686 * peers requested adaption layer.
1687 */
1688 if (asoc->peer.adaption_ind) {
1689 ev = sctp_ulpevent_make_adaption_indication(asoc, GFP_ATOMIC);
1690 if (!ev)
1691 goto nomem_ev;
1692
1693 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1694 SCTP_ULPEVENT(ev));
1695 }
1696
1697 return SCTP_DISPOSITION_CONSUME;
1698
1699nomem_ev:
1700 sctp_chunk_free(repl);
1701nomem:
1702 return SCTP_DISPOSITION_NOMEM;
1703}
1704
1705/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C')
1706 *
1707 * Section 5.2.4
1708 * C) In this case, the local endpoint's cookie has arrived late.
1709 * Before it arrived, the local endpoint sent an INIT and received an
1710 * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag
1711 * but a new tag of its own.
1712 */
1713/* This case represents an initialization collision. */
1714static sctp_disposition_t sctp_sf_do_dupcook_c(const struct sctp_endpoint *ep,
1715 const struct sctp_association *asoc,
1716 struct sctp_chunk *chunk,
1717 sctp_cmd_seq_t *commands,
1718 struct sctp_association *new_asoc)
1719{
1720 /* The cookie should be silently discarded.
1721 * The endpoint SHOULD NOT change states and should leave
1722 * any timers running.
1723 */
1724 return SCTP_DISPOSITION_DISCARD;
1725}
1726
1727/* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D')
1728 *
1729 * Section 5.2.4
1730 *
1731 * D) When both local and remote tags match the endpoint should always
1732 * enter the ESTABLISHED state, if it has not already done so.
1733 */
1734/* This case represents an initialization collision. */
1735static sctp_disposition_t sctp_sf_do_dupcook_d(const struct sctp_endpoint *ep,
1736 const struct sctp_association *asoc,
1737 struct sctp_chunk *chunk,
1738 sctp_cmd_seq_t *commands,
1739 struct sctp_association *new_asoc)
1740{
1741 struct sctp_ulpevent *ev = NULL;
1742 struct sctp_chunk *repl;
1743
1744 /* Clarification from Implementor's Guide:
1745 * D) When both local and remote tags match the endpoint should
1746 * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state.
1747 * It should stop any cookie timer that may be running and send
1748 * a COOKIE ACK.
1749 */
1750
1751 /* Don't accidentally move back into established state. */
1752 if (asoc->state < SCTP_STATE_ESTABLISHED) {
1753 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1754 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1755 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1756 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1757 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
1758 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START,
1759 SCTP_NULL());
1760
1761 /* RFC 2960 5.1 Normal Establishment of an Association
1762 *
1763 * D) IMPLEMENTATION NOTE: An implementation may choose
1764 * to send the Communication Up notification to the
1765 * SCTP user upon reception of a valid COOKIE
1766 * ECHO chunk.
1767 */
1768 ev = sctp_ulpevent_make_assoc_change(new_asoc, 0,
1769 SCTP_COMM_UP, 0,
1770 new_asoc->c.sinit_num_ostreams,
1771 new_asoc->c.sinit_max_instreams,
1772 GFP_ATOMIC);
1773 if (!ev)
1774 goto nomem;
1775 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1776 SCTP_ULPEVENT(ev));
1777
1778 /* Sockets API Draft Section 5.3.1.6
1779 * When a peer sends a Adaption Layer Indication parameter,
1780 * SCTP delivers this notification to inform the application
1781 * that of the peers requested adaption layer.
1782 */
1783 if (new_asoc->peer.adaption_ind) {
1784 ev = sctp_ulpevent_make_adaption_indication(new_asoc,
1785 GFP_ATOMIC);
1786 if (!ev)
1787 goto nomem;
1788
1789 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1790 SCTP_ULPEVENT(ev));
1791 }
1792 }
1793 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
1794
1795 repl = sctp_make_cookie_ack(new_asoc, chunk);
1796 if (!repl)
1797 goto nomem;
1798
1799 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1800 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
1801
1802 return SCTP_DISPOSITION_CONSUME;
1803
1804nomem:
1805 if (ev)
1806 sctp_ulpevent_free(ev);
1807 return SCTP_DISPOSITION_NOMEM;
1808}
1809
1810/*
1811 * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying
1812 * chunk was retransmitted and then delayed in the network.
1813 *
1814 * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists
1815 *
1816 * Verification Tag: None. Do cookie validation.
1817 *
1818 * Inputs
1819 * (endpoint, asoc, chunk)
1820 *
1821 * Outputs
1822 * (asoc, reply_msg, msg_up, timers, counters)
1823 *
1824 * The return value is the disposition of the chunk.
1825 */
1826sctp_disposition_t sctp_sf_do_5_2_4_dupcook(const struct sctp_endpoint *ep,
1827 const struct sctp_association *asoc,
1828 const sctp_subtype_t type,
1829 void *arg,
1830 sctp_cmd_seq_t *commands)
1831{
1832 sctp_disposition_t retval;
1833 struct sctp_chunk *chunk = arg;
1834 struct sctp_association *new_asoc;
1835 int error = 0;
1836 char action;
1837 struct sctp_chunk *err_chk_p;
1838
1839 /* Make sure that the chunk has a valid length from the protocol
1840 * perspective. In this case check to make sure we have at least
1841 * enough for the chunk header. Cookie length verification is
1842 * done later.
1843 */
1844 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
1845 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1846 commands);
1847
1848 /* "Decode" the chunk. We have no optional parameters so we
1849 * are in good shape.
1850 */
1851 chunk->subh.cookie_hdr = (struct sctp_signed_cookie *)chunk->skb->data;
1852 skb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
1853 sizeof(sctp_chunkhdr_t));
1854
1855 /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
1856 * of a duplicate COOKIE ECHO match the Verification Tags of the
1857 * current association, consider the State Cookie valid even if
1858 * the lifespan is exceeded.
1859 */
1860 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
1861 &err_chk_p);
1862
1863 /* FIXME:
1864 * If the re-build failed, what is the proper error path
1865 * from here?
1866 *
1867 * [We should abort the association. --piggy]
1868 */
1869 if (!new_asoc) {
1870 /* FIXME: Several errors are possible. A bad cookie should
1871 * be silently discarded, but think about logging it too.
1872 */
1873 switch (error) {
1874 case -SCTP_IERROR_NOMEM:
1875 goto nomem;
1876
1877 case -SCTP_IERROR_STALE_COOKIE:
1878 sctp_send_stale_cookie_err(ep, asoc, chunk, commands,
1879 err_chk_p);
1880 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1881 case -SCTP_IERROR_BAD_SIG:
1882 default:
1883 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1884 };
1885 }
1886
1887 /* Compare the tie_tag in cookie with the verification tag of
1888 * current association.
1889 */
1890 action = sctp_tietags_compare(new_asoc, asoc);
1891
1892 switch (action) {
1893 case 'A': /* Association restart. */
1894 retval = sctp_sf_do_dupcook_a(ep, asoc, chunk, commands,
1895 new_asoc);
1896 break;
1897
1898 case 'B': /* Collision case B. */
1899 retval = sctp_sf_do_dupcook_b(ep, asoc, chunk, commands,
1900 new_asoc);
1901 break;
1902
1903 case 'C': /* Collision case C. */
1904 retval = sctp_sf_do_dupcook_c(ep, asoc, chunk, commands,
1905 new_asoc);
1906 break;
1907
1908 case 'D': /* Collision case D. */
1909 retval = sctp_sf_do_dupcook_d(ep, asoc, chunk, commands,
1910 new_asoc);
1911 break;
1912
1913 default: /* Discard packet for all others. */
1914 retval = sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1915 break;
1916 };
1917
1918 /* Delete the tempory new association. */
1919 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
1920 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
1921
1922 return retval;
1923
1924nomem:
1925 return SCTP_DISPOSITION_NOMEM;
1926}
1927
1928/*
1929 * Process an ABORT. (SHUTDOWN-PENDING state)
1930 *
1931 * See sctp_sf_do_9_1_abort().
1932 */
1933sctp_disposition_t sctp_sf_shutdown_pending_abort(
1934 const struct sctp_endpoint *ep,
1935 const struct sctp_association *asoc,
1936 const sctp_subtype_t type,
1937 void *arg,
1938 sctp_cmd_seq_t *commands)
1939{
1940 struct sctp_chunk *chunk = arg;
1941
1942 if (!sctp_vtag_verify_either(chunk, asoc))
1943 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1944
1945 /* Make sure that the ABORT chunk has a valid length.
1946 * Since this is an ABORT chunk, we have to discard it
1947 * because of the following text:
1948 * RFC 2960, Section 3.3.7
1949 * If an endpoint receives an ABORT with a format error or for an
1950 * association that doesn't exist, it MUST silently discard it.
1951 * Becasue the length is "invalid", we can't really discard just
1952 * as we do not know its true length. So, to be safe, discard the
1953 * packet.
1954 */
1955 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
1956 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1957
1958 /* Stop the T5-shutdown guard timer. */
1959 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1960 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
1961
1962 return sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
1963}
1964
1965/*
1966 * Process an ABORT. (SHUTDOWN-SENT state)
1967 *
1968 * See sctp_sf_do_9_1_abort().
1969 */
1970sctp_disposition_t sctp_sf_shutdown_sent_abort(const struct sctp_endpoint *ep,
1971 const struct sctp_association *asoc,
1972 const sctp_subtype_t type,
1973 void *arg,
1974 sctp_cmd_seq_t *commands)
1975{
1976 struct sctp_chunk *chunk = arg;
1977
1978 if (!sctp_vtag_verify_either(chunk, asoc))
1979 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1980
1981 /* Make sure that the ABORT chunk has a valid length.
1982 * Since this is an ABORT chunk, we have to discard it
1983 * because of the following text:
1984 * RFC 2960, Section 3.3.7
1985 * If an endpoint receives an ABORT with a format error or for an
1986 * association that doesn't exist, it MUST silently discard it.
1987 * Becasue the length is "invalid", we can't really discard just
1988 * as we do not know its true length. So, to be safe, discard the
1989 * packet.
1990 */
1991 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
1992 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1993
1994 /* Stop the T2-shutdown timer. */
1995 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1996 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
1997
1998 /* Stop the T5-shutdown guard timer. */
1999 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2000 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
2001
2002 return sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
2003}
2004
2005/*
2006 * Process an ABORT. (SHUTDOWN-ACK-SENT state)
2007 *
2008 * See sctp_sf_do_9_1_abort().
2009 */
2010sctp_disposition_t sctp_sf_shutdown_ack_sent_abort(
2011 const struct sctp_endpoint *ep,
2012 const struct sctp_association *asoc,
2013 const sctp_subtype_t type,
2014 void *arg,
2015 sctp_cmd_seq_t *commands)
2016{
2017 /* The same T2 timer, so we should be able to use
2018 * common function with the SHUTDOWN-SENT state.
2019 */
2020 return sctp_sf_shutdown_sent_abort(ep, asoc, type, arg, commands);
2021}
2022
2023/*
2024 * Handle an Error received in COOKIE_ECHOED state.
2025 *
2026 * Only handle the error type of stale COOKIE Error, the other errors will
2027 * be ignored.
2028 *
2029 * Inputs
2030 * (endpoint, asoc, chunk)
2031 *
2032 * Outputs
2033 * (asoc, reply_msg, msg_up, timers, counters)
2034 *
2035 * The return value is the disposition of the chunk.
2036 */
2037sctp_disposition_t sctp_sf_cookie_echoed_err(const struct sctp_endpoint *ep,
2038 const struct sctp_association *asoc,
2039 const sctp_subtype_t type,
2040 void *arg,
2041 sctp_cmd_seq_t *commands)
2042{
2043 struct sctp_chunk *chunk = arg;
2044 sctp_errhdr_t *err;
2045
2046 if (!sctp_vtag_verify(chunk, asoc))
2047 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2048
2049 /* Make sure that the ERROR chunk has a valid length.
2050 * The parameter walking depends on this as well.
2051 */
2052 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
2053 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2054 commands);
2055
2056 /* Process the error here */
2057 /* FUTURE FIXME: When PR-SCTP related and other optional
2058 * parms are emitted, this will have to change to handle multiple
2059 * errors.
2060 */
2061 sctp_walk_errors(err, chunk->chunk_hdr) {
2062 if (SCTP_ERROR_STALE_COOKIE == err->cause)
2063 return sctp_sf_do_5_2_6_stale(ep, asoc, type,
2064 arg, commands);
2065 }
2066
2067 /* It is possible to have malformed error causes, and that
2068 * will cause us to end the walk early. However, since
2069 * we are discarding the packet, there should be no adverse
2070 * affects.
2071 */
2072 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2073}
2074
2075/*
2076 * Handle a Stale COOKIE Error
2077 *
2078 * Section: 5.2.6 Handle Stale COOKIE Error
2079 * If the association is in the COOKIE-ECHOED state, the endpoint may elect
2080 * one of the following three alternatives.
2081 * ...
2082 * 3) Send a new INIT chunk to the endpoint, adding a Cookie
2083 * Preservative parameter requesting an extension to the lifetime of
2084 * the State Cookie. When calculating the time extension, an
2085 * implementation SHOULD use the RTT information measured based on the
2086 * previous COOKIE ECHO / ERROR exchange, and should add no more
2087 * than 1 second beyond the measured RTT, due to long State Cookie
2088 * lifetimes making the endpoint more subject to a replay attack.
2089 *
2090 * Verification Tag: Not explicit, but safe to ignore.
2091 *
2092 * Inputs
2093 * (endpoint, asoc, chunk)
2094 *
2095 * Outputs
2096 * (asoc, reply_msg, msg_up, timers, counters)
2097 *
2098 * The return value is the disposition of the chunk.
2099 */
2100static sctp_disposition_t sctp_sf_do_5_2_6_stale(const struct sctp_endpoint *ep,
2101 const struct sctp_association *asoc,
2102 const sctp_subtype_t type,
2103 void *arg,
2104 sctp_cmd_seq_t *commands)
2105{
2106 struct sctp_chunk *chunk = arg;
2107 time_t stale;
2108 sctp_cookie_preserve_param_t bht;
2109 sctp_errhdr_t *err;
2110 struct sctp_chunk *reply;
2111 struct sctp_bind_addr *bp;
3f7a87d2 2112 int attempts = asoc->init_err_counter + 1;
1da177e4
LT		 2113
2114 if (attempts >= asoc->max_init_attempts) {
2115 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
2116 SCTP_U32(SCTP_ERROR_STALE_COOKIE));
2117 return SCTP_DISPOSITION_DELETE_TCB;
2118 }
2119
2120 err = (sctp_errhdr_t *)(chunk->skb->data);
2121
2122 /* When calculating the time extension, an implementation
2123 * SHOULD use the RTT information measured based on the
2124 * previous COOKIE ECHO / ERROR exchange, and should add no
2125 * more than 1 second beyond the measured RTT, due to long
2126 * State Cookie lifetimes making the endpoint more subject to
2127 * a replay attack.
2128 * Measure of Staleness's unit is usec. (1/1000000 sec)
2129 * Suggested Cookie Life-span Increment's unit is msec.
2130 * (1/1000 sec)
2131 * In general, if you use the suggested cookie life, the value
2132 * found in the field of measure of staleness should be doubled
2133 * to give ample time to retransmit the new cookie and thus
2134 * yield a higher probability of success on the reattempt.
2135 */
2136 stale = ntohl(*(suseconds_t *)((u8 *)err + sizeof(sctp_errhdr_t)));
2137 stale = (stale * 2) / 1000;
2138
2139 bht.param_hdr.type = SCTP_PARAM_COOKIE_PRESERVATIVE;
2140 bht.param_hdr.length = htons(sizeof(bht));
2141 bht.lifespan_increment = htonl(stale);
2142
2143 /* Build that new INIT chunk. */
2144 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
2145 reply = sctp_make_init(asoc, bp, GFP_ATOMIC, sizeof(bht));
2146 if (!reply)
2147 goto nomem;
2148
2149 sctp_addto_chunk(reply, sizeof(bht), &bht);
2150
2151 /* Clear peer's init_tag cached in assoc as we are sending a new INIT */
2152 sctp_add_cmd_sf(commands, SCTP_CMD_CLEAR_INIT_TAG, SCTP_NULL());
2153
2154 /* Stop pending T3-rtx and heartbeat timers */
2155 sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
2156 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
2157
2158 /* Delete non-primary peer ip addresses since we are transitioning
2159 * back to the COOKIE-WAIT state
2160 */
2161 sctp_add_cmd_sf(commands, SCTP_CMD_DEL_NON_PRIMARY, SCTP_NULL());
2162
2163 /* If we've sent any data bundled with COOKIE-ECHO we will need to
2164 * resend
2165 */
2166 sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN,
2167 SCTP_TRANSPORT(asoc->peer.primary_path));
2168
2169 /* Cast away the const modifier, as we want to just
2170 * rerun it through as a sideffect.
2171 */
3f7a87d2 2172 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_INC, SCTP_NULL());
1da177e4
LT		 2173
2174 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2175 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
2176 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2177 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
2178 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
2179 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
2180
2181 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2182
2183 return SCTP_DISPOSITION_CONSUME;
2184
2185nomem:
2186 return SCTP_DISPOSITION_NOMEM;
2187}
2188
2189/*
2190 * Process an ABORT.
2191 *
2192 * Section: 9.1
2193 * After checking the Verification Tag, the receiving endpoint shall
2194 * remove the association from its record, and shall report the
2195 * termination to its upper layer.
2196 *
2197 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
2198 * B) Rules for packet carrying ABORT:
2199 *
2200 * - The endpoint shall always fill in the Verification Tag field of the
2201 * outbound packet with the destination endpoint's tag value if it
2202 * is known.
2203 *
2204 * - If the ABORT is sent in response to an OOTB packet, the endpoint
2205 * MUST follow the procedure described in Section 8.4.
2206 *
2207 * - The receiver MUST accept the packet if the Verification Tag
2208 * matches either its own tag, OR the tag of its peer. Otherwise, the
2209 * receiver MUST silently discard the packet and take no further
2210 * action.
2211 *
2212 * Inputs
2213 * (endpoint, asoc, chunk)
2214 *
2215 * Outputs
2216 * (asoc, reply_msg, msg_up, timers, counters)
2217 *
2218 * The return value is the disposition of the chunk.
2219 */
2220sctp_disposition_t sctp_sf_do_9_1_abort(const struct sctp_endpoint *ep,
2221 const struct sctp_association *asoc,
2222 const sctp_subtype_t type,
2223 void *arg,
2224 sctp_cmd_seq_t *commands)
2225{
2226 struct sctp_chunk *chunk = arg;
2227 unsigned len;
2228 __u16 error = SCTP_ERROR_NO_ERROR;
2229
2230 if (!sctp_vtag_verify_either(chunk, asoc))
2231 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2232
2233 /* Make sure that the ABORT chunk has a valid length.
2234 * Since this is an ABORT chunk, we have to discard it
2235 * because of the following text:
2236 * RFC 2960, Section 3.3.7
2237 * If an endpoint receives an ABORT with a format error or for an
2238 * association that doesn't exist, it MUST silently discard it.
2239 * Becasue the length is "invalid", we can't really discard just
2240 * as we do not know its true length. So, to be safe, discard the
2241 * packet.
2242 */
2243 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2244 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2245
2246 /* See if we have an error cause code in the chunk. */
2247 len = ntohs(chunk->chunk_hdr->length);
2248 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
2249 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2250
2251 /* ASSOC_FAILED will DELETE_TCB. */
2252 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, SCTP_U32(error));
2253 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
2254 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
2255
2256 return SCTP_DISPOSITION_ABORT;
2257}
2258
2259/*
2260 * Process an ABORT. (COOKIE-WAIT state)
2261 *
2262 * See sctp_sf_do_9_1_abort() above.
2263 */
2264sctp_disposition_t sctp_sf_cookie_wait_abort(const struct sctp_endpoint *ep,
2265 const struct sctp_association *asoc,
2266 const sctp_subtype_t type,
2267 void *arg,
2268 sctp_cmd_seq_t *commands)
2269{
2270 struct sctp_chunk *chunk = arg;
2271 unsigned len;
2272 __u16 error = SCTP_ERROR_NO_ERROR;
2273
2274 if (!sctp_vtag_verify_either(chunk, asoc))
2275 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2276
2277 /* Make sure that the ABORT chunk has a valid length.
2278 * Since this is an ABORT chunk, we have to discard it
2279 * because of the following text:
2280 * RFC 2960, Section 3.3.7
2281 * If an endpoint receives an ABORT with a format error or for an
2282 * association that doesn't exist, it MUST silently discard it.
2283 * Becasue the length is "invalid", we can't really discard just
2284 * as we do not know its true length. So, to be safe, discard the
2285 * packet.
2286 */
2287 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2288 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2289
2290 /* See if we have an error cause code in the chunk. */
2291 len = ntohs(chunk->chunk_hdr->length);
2292 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
2293 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2294
3f7a87d2 2295 return sctp_stop_t1_and_abort(commands, error, asoc, chunk->transport);
1da177e4
LT		 2296}
2297
2298/*
2299 * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state)
2300 */
2301sctp_disposition_t sctp_sf_cookie_wait_icmp_abort(const struct sctp_endpoint *ep,
2302 const struct sctp_association *asoc,
2303 const sctp_subtype_t type,
2304 void *arg,
2305 sctp_cmd_seq_t *commands)
2306{
3f7a87d2
FF		 2307 return sctp_stop_t1_and_abort(commands, SCTP_ERROR_NO_ERROR, asoc,
2308 (struct sctp_transport *)arg);
1da177e4
LT		 2309}
2310
2311/*
2312 * Process an ABORT. (COOKIE-ECHOED state)
2313 */
2314sctp_disposition_t sctp_sf_cookie_echoed_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{
2320 /* There is a single T1 timer, so we should be able to use
2321 * common function with the COOKIE-WAIT state.
2322 */
2323 return sctp_sf_cookie_wait_abort(ep, asoc, type, arg, commands);
2324}
2325
2326/*
2327 * Stop T1 timer and abort association with "INIT failed".
2328 *
2329 * This is common code called by several sctp_sf_*_abort() functions above.
2330 */
3f7a87d2
FF		 2331sctp_disposition_t sctp_stop_t1_and_abort(sctp_cmd_seq_t *commands,
2332 __u16 error,
2333 const struct sctp_association *asoc,
2334 struct sctp_transport *transport)
1da177e4 2335{
3f7a87d2 2336 SCTP_DEBUG_PRINTK("ABORT received (INIT).\n");
1da177e4
LT		 2337 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2338 SCTP_STATE(SCTP_STATE_CLOSED));
2339 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
2340 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2341 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
2342 /* CMD_INIT_FAILED will DELETE_TCB. */
2343 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
2344 SCTP_U32(error));
3f7a87d2 2345 return SCTP_DISPOSITION_ABORT;
1da177e4
LT		 2346}
2347
2348/*
2349 * sctp_sf_do_9_2_shut
2350 *
2351 * Section: 9.2
2352 * Upon the reception of the SHUTDOWN, the peer endpoint shall
2353 * - enter the SHUTDOWN-RECEIVED state,
2354 *
2355 * - stop accepting new data from its SCTP user
2356 *
2357 * - verify, by checking the Cumulative TSN Ack field of the chunk,
2358 * that all its outstanding DATA chunks have been received by the
2359 * SHUTDOWN sender.
2360 *
2361 * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT
2362 * send a SHUTDOWN in response to a ULP request. And should discard
2363 * subsequent SHUTDOWN chunks.
2364 *
2365 * If there are still outstanding DATA chunks left, the SHUTDOWN
2366 * receiver shall continue to follow normal data transmission
2367 * procedures defined in Section 6 until all outstanding DATA chunks
2368 * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept
2369 * new data from its SCTP user.
2370 *
2371 * Verification Tag: 8.5 Verification Tag [Normal verification]
2372 *
2373 * Inputs
2374 * (endpoint, asoc, chunk)
2375 *
2376 * Outputs
2377 * (asoc, reply_msg, msg_up, timers, counters)
2378 *
2379 * The return value is the disposition of the chunk.
2380 */
2381sctp_disposition_t sctp_sf_do_9_2_shutdown(const struct sctp_endpoint *ep,
2382 const struct sctp_association *asoc,
2383 const sctp_subtype_t type,
2384 void *arg,
2385 sctp_cmd_seq_t *commands)
2386{
2387 struct sctp_chunk *chunk = arg;
2388 sctp_shutdownhdr_t *sdh;
2389 sctp_disposition_t disposition;
2390 struct sctp_ulpevent *ev;
2391
2392 if (!sctp_vtag_verify(chunk, asoc))
2393 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2394
2395 /* Make sure that the SHUTDOWN chunk has a valid length. */
2396 if (!sctp_chunk_length_valid(chunk,
2397 sizeof(struct sctp_shutdown_chunk_t)))
2398 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2399 commands);
2400
2401 /* Convert the elaborate header. */
2402 sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
2403 skb_pull(chunk->skb, sizeof(sctp_shutdownhdr_t));
2404 chunk->subh.shutdown_hdr = sdh;
2405
2406 /* Upon the reception of the SHUTDOWN, the peer endpoint shall
2407 * - enter the SHUTDOWN-RECEIVED state,
2408 * - stop accepting new data from its SCTP user
2409 *
2410 * [This is implicit in the new state.]
2411 */
2412 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2413 SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED));
2414 disposition = SCTP_DISPOSITION_CONSUME;
2415
2416 if (sctp_outq_is_empty(&asoc->outqueue)) {
2417 disposition = sctp_sf_do_9_2_shutdown_ack(ep, asoc, type,
2418 arg, commands);
2419 }
2420
2421 if (SCTP_DISPOSITION_NOMEM == disposition)
2422 goto out;
2423
2424 /* - verify, by checking the Cumulative TSN Ack field of the
2425 * chunk, that all its outstanding DATA chunks have been
2426 * received by the SHUTDOWN sender.
2427 */
2428 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
2429 SCTP_U32(chunk->subh.shutdown_hdr->cum_tsn_ack));
2430
2431 /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT
2432 * When a peer sends a SHUTDOWN, SCTP delivers this notification to
2433 * inform the application that it should cease sending data.
2434 */
2435 ev = sctp_ulpevent_make_shutdown_event(asoc, 0, GFP_ATOMIC);
2436 if (!ev) {
2437 disposition = SCTP_DISPOSITION_NOMEM;
2438 goto out;
2439 }
2440 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
2441
2442out:
2443 return disposition;
2444}
2445
2446/* RFC 2960 9.2
2447 * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk
2448 * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination
2449 * transport addresses (either in the IP addresses or in the INIT chunk)
2450 * that belong to this association, it should discard the INIT chunk and
2451 * retransmit the SHUTDOWN ACK chunk.
2452 */
2453sctp_disposition_t sctp_sf_do_9_2_reshutack(const struct sctp_endpoint *ep,
2454 const struct sctp_association *asoc,
2455 const sctp_subtype_t type,
2456 void *arg,
2457 sctp_cmd_seq_t *commands)
2458{
2459 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
2460 struct sctp_chunk *reply;
2461
2462 /* Since we are not going to really process this INIT, there
2463 * is no point in verifying chunk boundries. Just generate
2464 * the SHUTDOWN ACK.
2465 */
2466 reply = sctp_make_shutdown_ack(asoc, chunk);
2467 if (NULL == reply)
2468 goto nomem;
2469
2470 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
2471 * the T2-SHUTDOWN timer.
2472 */
2473 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
2474
2475 /* and restart the T2-shutdown timer. */
2476 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2477 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2478
2479 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2480
2481 return SCTP_DISPOSITION_CONSUME;
2482nomem:
2483 return SCTP_DISPOSITION_NOMEM;
2484}
2485
2486/*
2487 * sctp_sf_do_ecn_cwr
2488 *
2489 * Section: Appendix A: Explicit Congestion Notification
2490 *
2491 * CWR:
2492 *
2493 * RFC 2481 details a specific bit for a sender to send in the header of
2494 * its next outbound TCP segment to indicate to its peer that it has
2495 * reduced its congestion window. This is termed the CWR bit. For
2496 * SCTP the same indication is made by including the CWR chunk.
2497 * This chunk contains one data element, i.e. the TSN number that
2498 * was sent in the ECNE chunk. This element represents the lowest
2499 * TSN number in the datagram that was originally marked with the
2500 * CE bit.
2501 *
2502 * Verification Tag: 8.5 Verification Tag [Normal verification]
2503 * Inputs
2504 * (endpoint, asoc, chunk)
2505 *
2506 * Outputs
2507 * (asoc, reply_msg, msg_up, timers, counters)
2508 *
2509 * The return value is the disposition of the chunk.
2510 */
2511sctp_disposition_t sctp_sf_do_ecn_cwr(const struct sctp_endpoint *ep,
2512 const struct sctp_association *asoc,
2513 const sctp_subtype_t type,
2514 void *arg,
2515 sctp_cmd_seq_t *commands)
2516{
2517 sctp_cwrhdr_t *cwr;
2518 struct sctp_chunk *chunk = arg;
2519
2520 if (!sctp_vtag_verify(chunk, asoc))
2521 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2522
2523 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2524 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2525 commands);
2526
2527 cwr = (sctp_cwrhdr_t *) chunk->skb->data;
2528 skb_pull(chunk->skb, sizeof(sctp_cwrhdr_t));
2529
2530 cwr->lowest_tsn = ntohl(cwr->lowest_tsn);
2531
2532 /* Does this CWR ack the last sent congestion notification? */
2533 if (TSN_lte(asoc->last_ecne_tsn, cwr->lowest_tsn)) {
2534 /* Stop sending ECNE. */
2535 sctp_add_cmd_sf(commands,
2536 SCTP_CMD_ECN_CWR,
2537 SCTP_U32(cwr->lowest_tsn));
2538 }
2539 return SCTP_DISPOSITION_CONSUME;
2540}
2541
2542/*
2543 * sctp_sf_do_ecne
2544 *
2545 * Section: Appendix A: Explicit Congestion Notification
2546 *
2547 * ECN-Echo
2548 *
2549 * RFC 2481 details a specific bit for a receiver to send back in its
2550 * TCP acknowledgements to notify the sender of the Congestion
2551 * Experienced (CE) bit having arrived from the network. For SCTP this
2552 * same indication is made by including the ECNE chunk. This chunk
2553 * contains one data element, i.e. the lowest TSN associated with the IP
2554 * datagram marked with the CE bit.....
2555 *
2556 * Verification Tag: 8.5 Verification Tag [Normal verification]
2557 * Inputs
2558 * (endpoint, asoc, chunk)
2559 *
2560 * Outputs
2561 * (asoc, reply_msg, msg_up, timers, counters)
2562 *
2563 * The return value is the disposition of the chunk.
2564 */
2565sctp_disposition_t sctp_sf_do_ecne(const struct sctp_endpoint *ep,
2566 const struct sctp_association *asoc,
2567 const sctp_subtype_t type,
2568 void *arg,
2569 sctp_cmd_seq_t *commands)
2570{
2571 sctp_ecnehdr_t *ecne;
2572 struct sctp_chunk *chunk = arg;
2573
2574 if (!sctp_vtag_verify(chunk, asoc))
2575 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2576
2577 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2578 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2579 commands);
2580
2581 ecne = (sctp_ecnehdr_t *) chunk->skb->data;
2582 skb_pull(chunk->skb, sizeof(sctp_ecnehdr_t));
2583
2584 /* If this is a newer ECNE than the last CWR packet we sent out */
2585 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_ECNE,
2586 SCTP_U32(ntohl(ecne->lowest_tsn)));
2587
2588 return SCTP_DISPOSITION_CONSUME;
2589}
2590
2591/*
2592 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
2593 *
2594 * The SCTP endpoint MUST always acknowledge the reception of each valid
2595 * DATA chunk.
2596 *
2597 * The guidelines on delayed acknowledgement algorithm specified in
2598 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
2599 * acknowledgement SHOULD be generated for at least every second packet
2600 * (not every second DATA chunk) received, and SHOULD be generated within
2601 * 200 ms of the arrival of any unacknowledged DATA chunk. In some
2602 * situations it may be beneficial for an SCTP transmitter to be more
2603 * conservative than the algorithms detailed in this document allow.
2604 * However, an SCTP transmitter MUST NOT be more aggressive than the
2605 * following algorithms allow.
2606 *
2607 * A SCTP receiver MUST NOT generate more than one SACK for every
2608 * incoming packet, other than to update the offered window as the
2609 * receiving application consumes new data.
2610 *
2611 * Verification Tag: 8.5 Verification Tag [Normal verification]
2612 *
2613 * Inputs
2614 * (endpoint, asoc, chunk)
2615 *
2616 * Outputs
2617 * (asoc, reply_msg, msg_up, timers, counters)
2618 *
2619 * The return value is the disposition of the chunk.
2620 */
2621sctp_disposition_t sctp_sf_eat_data_6_2(const struct sctp_endpoint *ep,
2622 const struct sctp_association *asoc,
2623 const sctp_subtype_t type,
2624 void *arg,
2625 sctp_cmd_seq_t *commands)
2626{
2627 struct sctp_chunk *chunk = arg;
2628 int error;
2629
2630 if (!sctp_vtag_verify(chunk, asoc)) {
2631 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
2632 SCTP_NULL());
2633 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2634 }
2635
2636 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
2637 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2638 commands);
2639
2640 error = sctp_eat_data(asoc, chunk, commands );
2641 switch (error) {
2642 case SCTP_IERROR_NO_ERROR:
2643 break;
2644 case SCTP_IERROR_HIGH_TSN:
2645 case SCTP_IERROR_BAD_STREAM:
2646 goto discard_noforce;
2647 case SCTP_IERROR_DUP_TSN:
2648 case SCTP_IERROR_IGNORE_TSN:
2649 goto discard_force;
2650 case SCTP_IERROR_NO_DATA:
2651 goto consume;
2652 default:
2653 BUG();
2654 }
2655
2656 if (asoc->autoclose) {
2657 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2658 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
2659 }
2660
2661 /* If this is the last chunk in a packet, we need to count it
2662 * toward sack generation. Note that we need to SACK every
2663 * OTHER packet containing data chunks, EVEN IF WE DISCARD
2664 * THEM. We elect to NOT generate SACK's if the chunk fails
2665 * the verification tag test.
2666 *
2667 * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2668 *
2669 * The SCTP endpoint MUST always acknowledge the reception of
2670 * each valid DATA chunk.
2671 *
2672 * The guidelines on delayed acknowledgement algorithm
2673 * specified in Section 4.2 of [RFC2581] SHOULD be followed.
2674 * Specifically, an acknowledgement SHOULD be generated for at
2675 * least every second packet (not every second DATA chunk)
2676 * received, and SHOULD be generated within 200 ms of the
2677 * arrival of any unacknowledged DATA chunk. In some
2678 * situations it may be beneficial for an SCTP transmitter to
2679 * be more conservative than the algorithms detailed in this
2680 * document allow. However, an SCTP transmitter MUST NOT be
2681 * more aggressive than the following algorithms allow.
2682 */
2683 if (chunk->end_of_packet) {
2684 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
2685
2686 /* Start the SACK timer. */
2687 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2688 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
2689 }
2690
2691 return SCTP_DISPOSITION_CONSUME;
2692
2693discard_force:
2694 /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2695 *
2696 * When a packet arrives with duplicate DATA chunk(s) and with
2697 * no new DATA chunk(s), the endpoint MUST immediately send a
2698 * SACK with no delay. If a packet arrives with duplicate
2699 * DATA chunk(s) bundled with new DATA chunks, the endpoint
2700 * MAY immediately send a SACK. Normally receipt of duplicate
2701 * DATA chunks will occur when the original SACK chunk was lost
2702 * and the peer's RTO has expired. The duplicate TSN number(s)
2703 * SHOULD be reported in the SACK as duplicate.
2704 */
2705 /* In our case, we split the MAY SACK advice up whether or not
2706 * the last chunk is a duplicate.'
2707 */
2708 if (chunk->end_of_packet)
2709 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
2710 return SCTP_DISPOSITION_DISCARD;
2711
2712discard_noforce:
2713 if (chunk->end_of_packet) {
2714 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
2715
2716 /* Start the SACK timer. */
2717 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2718 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
2719 }
2720 return SCTP_DISPOSITION_DISCARD;
2721consume:
2722 return SCTP_DISPOSITION_CONSUME;
2723
2724}
2725
2726/*
2727 * sctp_sf_eat_data_fast_4_4
2728 *
2729 * Section: 4 (4)
2730 * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received
2731 * DATA chunks without delay.
2732 *
2733 * Verification Tag: 8.5 Verification Tag [Normal verification]
2734 * Inputs
2735 * (endpoint, asoc, chunk)
2736 *
2737 * Outputs
2738 * (asoc, reply_msg, msg_up, timers, counters)
2739 *
2740 * The return value is the disposition of the chunk.
2741 */
2742sctp_disposition_t sctp_sf_eat_data_fast_4_4(const struct sctp_endpoint *ep,
2743 const struct sctp_association *asoc,
2744 const sctp_subtype_t type,
2745 void *arg,
2746 sctp_cmd_seq_t *commands)
2747{
2748 struct sctp_chunk *chunk = arg;
2749 int error;
2750
2751 if (!sctp_vtag_verify(chunk, asoc)) {
2752 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
2753 SCTP_NULL());
2754 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2755 }
2756
2757 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
2758 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2759 commands);
2760
2761 error = sctp_eat_data(asoc, chunk, commands );
2762 switch (error) {
2763 case SCTP_IERROR_NO_ERROR:
2764 case SCTP_IERROR_HIGH_TSN:
2765 case SCTP_IERROR_DUP_TSN:
2766 case SCTP_IERROR_IGNORE_TSN:
2767 case SCTP_IERROR_BAD_STREAM:
2768 break;
2769 case SCTP_IERROR_NO_DATA:
2770 goto consume;
2771 default:
2772 BUG();
2773 }
2774
2775 /* Go a head and force a SACK, since we are shutting down. */
2776
2777 /* Implementor's Guide.
2778 *
2779 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
2780 * respond to each received packet containing one or more DATA chunk(s)
2781 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
2782 */
2783 if (chunk->end_of_packet) {
2784 /* We must delay the chunk creation since the cumulative
2785 * TSN has not been updated yet.
2786 */
2787 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
2788 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
2789 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2790 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2791 }
2792
2793consume:
2794 return SCTP_DISPOSITION_CONSUME;
2795}
2796
2797/*
2798 * Section: 6.2 Processing a Received SACK
2799 * D) Any time a SACK arrives, the endpoint performs the following:
2800 *
2801 * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point,
2802 * then drop the SACK. Since Cumulative TSN Ack is monotonically
2803 * increasing, a SACK whose Cumulative TSN Ack is less than the
2804 * Cumulative TSN Ack Point indicates an out-of-order SACK.
2805 *
2806 * ii) Set rwnd equal to the newly received a_rwnd minus the number
2807 * of bytes still outstanding after processing the Cumulative TSN Ack
2808 * and the Gap Ack Blocks.
2809 *
2810 * iii) If the SACK is missing a TSN that was previously
2811 * acknowledged via a Gap Ack Block (e.g., the data receiver
2812 * reneged on the data), then mark the corresponding DATA chunk
2813 * as available for retransmit: Mark it as missing for fast
2814 * retransmit as described in Section 7.2.4 and if no retransmit
2815 * timer is running for the destination address to which the DATA
2816 * chunk was originally transmitted, then T3-rtx is started for
2817 * that destination address.
2818 *
2819 * Verification Tag: 8.5 Verification Tag [Normal verification]
2820 *
2821 * Inputs
2822 * (endpoint, asoc, chunk)
2823 *
2824 * Outputs
2825 * (asoc, reply_msg, msg_up, timers, counters)
2826 *
2827 * The return value is the disposition of the chunk.
2828 */
2829sctp_disposition_t sctp_sf_eat_sack_6_2(const struct sctp_endpoint *ep,
2830 const struct sctp_association *asoc,
2831 const sctp_subtype_t type,
2832 void *arg,
2833 sctp_cmd_seq_t *commands)
2834{
2835 struct sctp_chunk *chunk = arg;
2836 sctp_sackhdr_t *sackh;
2837 __u32 ctsn;
2838
2839 if (!sctp_vtag_verify(chunk, asoc))
2840 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2841
2842 /* Make sure that the SACK chunk has a valid length. */
2843 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_sack_chunk_t)))
2844 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2845 commands);
2846
2847 /* Pull the SACK chunk from the data buffer */
2848 sackh = sctp_sm_pull_sack(chunk);
2849 /* Was this a bogus SACK? */
2850 if (!sackh)
2851 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2852 chunk->subh.sack_hdr = sackh;
2853 ctsn = ntohl(sackh->cum_tsn_ack);
2854
2855 /* i) If Cumulative TSN Ack is less than the Cumulative TSN
2856 * Ack Point, then drop the SACK. Since Cumulative TSN
2857 * Ack is monotonically increasing, a SACK whose
2858 * Cumulative TSN Ack is less than the Cumulative TSN Ack
2859 * Point indicates an out-of-order SACK.
2860 */
2861 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
2862 SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn);
2863 SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc->ctsn_ack_point);
2864 return SCTP_DISPOSITION_DISCARD;
2865 }
2866
2867 /* Return this SACK for further processing. */
2868 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_SACKH(sackh));
2869
2870 /* Note: We do the rest of the work on the PROCESS_SACK
2871 * sideeffect.
2872 */
2873 return SCTP_DISPOSITION_CONSUME;
2874}
2875
2876/*
2877 * Generate an ABORT in response to a packet.
2878 *
047a2428 2879 * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41
1da177e4 2880 *
047a2428
JF		 2881 * 8) The receiver should respond to the sender of the OOTB packet with
2882 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
2883 * MUST fill in the Verification Tag field of the outbound packet
2884 * with the value found in the Verification Tag field of the OOTB
2885 * packet and set the T-bit in the Chunk Flags to indicate that the
2886 * Verification Tag is reflected. After sending this ABORT, the
2887 * receiver of the OOTB packet shall discard the OOTB packet and take
2888 * no further action.
1da177e4
LT		 2889 *
2890 * Verification Tag:
2891 *
2892 * The return value is the disposition of the chunk.
2893*/
2894sctp_disposition_t sctp_sf_tabort_8_4_8(const struct sctp_endpoint *ep,
2895 const struct sctp_association *asoc,
2896 const sctp_subtype_t type,
2897 void *arg,
2898 sctp_cmd_seq_t *commands)
2899{
2900 struct sctp_packet *packet = NULL;
2901 struct sctp_chunk *chunk = arg;
2902 struct sctp_chunk *abort;
2903
2904 packet = sctp_ootb_pkt_new(asoc, chunk);
2905
2906 if (packet) {
2907 /* Make an ABORT. The T bit will be set if the asoc
2908 * is NULL.
2909 */
2910 abort = sctp_make_abort(asoc, chunk, 0);
2911 if (!abort) {
2912 sctp_ootb_pkt_free(packet);
2913 return SCTP_DISPOSITION_NOMEM;
2914 }
2915
047a2428
JF		 2916 /* Reflect vtag if T-Bit is set */
2917 if (sctp_test_T_bit(abort))
2918 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
2919
1da177e4
LT		 2920 /* Set the skb to the belonging sock for accounting. */
2921 abort->skb->sk = ep->base.sk;
2922
2923 sctp_packet_append_chunk(packet, abort);
2924
2925 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
2926 SCTP_PACKET(packet));
2927
2928 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
2929
2930 return SCTP_DISPOSITION_CONSUME;
2931 }
2932
2933 return SCTP_DISPOSITION_NOMEM;
2934}
2935
2936/*
2937 * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR
2938 * event as ULP notification for each cause included in the chunk.
2939 *
2940 * API 5.3.1.3 - SCTP_REMOTE_ERROR
2941 *
2942 * The return value is the disposition of the chunk.
2943*/
2944sctp_disposition_t sctp_sf_operr_notify(const struct sctp_endpoint *ep,
2945 const struct sctp_association *asoc,
2946 const sctp_subtype_t type,
2947 void *arg,
2948 sctp_cmd_seq_t *commands)
2949{
2950 struct sctp_chunk *chunk = arg;
2951 struct sctp_ulpevent *ev;
2952
2953 if (!sctp_vtag_verify(chunk, asoc))
2954 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2955
2956 /* Make sure that the ERROR chunk has a valid length. */
2957 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
2958 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2959 commands);
2960
2961 while (chunk->chunk_end > chunk->skb->data) {
2962 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
2963 GFP_ATOMIC);
2964 if (!ev)
2965 goto nomem;
2966
2967 if (!sctp_add_cmd(commands, SCTP_CMD_EVENT_ULP,
2968 SCTP_ULPEVENT(ev))) {
2969 sctp_ulpevent_free(ev);
2970 goto nomem;
2971 }
2972
2973 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_OPERR,
2974 SCTP_CHUNK(chunk));
2975 }
2976 return SCTP_DISPOSITION_CONSUME;
2977
2978nomem:
2979 return SCTP_DISPOSITION_NOMEM;
2980}
2981
2982/*
2983 * Process an inbound SHUTDOWN ACK.
2984 *
2985 * From Section 9.2:
2986 * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
2987 * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its
2988 * peer, and remove all record of the association.
2989 *
2990 * The return value is the disposition.
2991 */
2992sctp_disposition_t sctp_sf_do_9_2_final(const struct sctp_endpoint *ep,
2993 const struct sctp_association *asoc,
2994 const sctp_subtype_t type,
2995 void *arg,
2996 sctp_cmd_seq_t *commands)
2997{
2998 struct sctp_chunk *chunk = arg;
2999 struct sctp_chunk *reply;
3000 struct sctp_ulpevent *ev;
3001
3002 if (!sctp_vtag_verify(chunk, asoc))
3003 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3004
3005 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3006 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3007 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3008 commands);
3009
3010 /* 10.2 H) SHUTDOWN COMPLETE notification
3011 *
3012 * When SCTP completes the shutdown procedures (section 9.2) this
3013 * notification is passed to the upper layer.
3014 */
3015 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
3016 0, 0, 0, GFP_ATOMIC);
3017 if (!ev)
3018 goto nomem;
3019
3020 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
3021
3022 /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3023 * stop the T2-shutdown timer,
3024 */
3025 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3026 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3027
3028 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3029 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
3030
3031 /* ...send a SHUTDOWN COMPLETE chunk to its peer, */
3032 reply = sctp_make_shutdown_complete(asoc, chunk);
3033 if (!reply)
3034 goto nomem;
3035
3036 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3037 SCTP_STATE(SCTP_STATE_CLOSED));
3038 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
3039 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3040 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
3041
3042 /* ...and remove all record of the association. */
3043 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
3044 return SCTP_DISPOSITION_DELETE_TCB;
3045
3046nomem:
3047 return SCTP_DISPOSITION_NOMEM;
3048}
3049
3050/*
047a2428
JF		 3051 * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41.
3052 *
1da177e4
LT		 3053 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3054 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3055 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3056 * packet must fill in the Verification Tag field of the outbound
3057 * packet with the Verification Tag received in the SHUTDOWN ACK and
047a2428
JF		 3058 * set the T-bit in the Chunk Flags to indicate that the Verification
3059 * Tag is reflected.
1da177e4
LT		 3060 *
3061 * 8) The receiver should respond to the sender of the OOTB packet with
3062 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3063 * MUST fill in the Verification Tag field of the outbound packet
3064 * with the value found in the Verification Tag field of the OOTB
047a2428
JF		 3065 * packet and set the T-bit in the Chunk Flags to indicate that the
3066 * Verification Tag is reflected. After sending this ABORT, the
3067 * receiver of the OOTB packet shall discard the OOTB packet and take
3068 * no further action.
1da177e4
LT		 3069 */
3070sctp_disposition_t sctp_sf_ootb(const struct sctp_endpoint *ep,
3071 const struct sctp_association *asoc,
3072 const sctp_subtype_t type,
3073 void *arg,
3074 sctp_cmd_seq_t *commands)
3075{
3076 struct sctp_chunk *chunk = arg;
3077 struct sk_buff *skb = chunk->skb;
3078 sctp_chunkhdr_t *ch;
3079 __u8 *ch_end;
3080 int ootb_shut_ack = 0;
3081
3082 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES);
3083
3084 ch = (sctp_chunkhdr_t *) chunk->chunk_hdr;
3085 do {
3086 /* Break out if chunk length is less then minimal. */
3087 if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t))
3088 break;
3089
3090 ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
3091
3092 if (SCTP_CID_SHUTDOWN_ACK == ch->type)
3093 ootb_shut_ack = 1;
3094
3095 /* RFC 2960, Section 3.3.7
3096 * Moreover, under any circumstances, an endpoint that
3097 * receives an ABORT MUST NOT respond to that ABORT by
3098 * sending an ABORT of its own.
3099 */
3100 if (SCTP_CID_ABORT == ch->type)
3101 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3102
3103 ch = (sctp_chunkhdr_t *) ch_end;
3104 } while (ch_end < skb->tail);
3105
3106 if (ootb_shut_ack)
3107 sctp_sf_shut_8_4_5(ep, asoc, type, arg, commands);
3108 else
3109 sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
3110
3111 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3112}
3113
3114/*
3115 * Handle an "Out of the blue" SHUTDOWN ACK.
3116 *
047a2428
JF		 3117 * Section: 8.4 5, sctpimpguide 2.41.
3118 *
1da177e4 3119 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
047a2428
JF		 3120 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3121 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3122 * packet must fill in the Verification Tag field of the outbound
3123 * packet with the Verification Tag received in the SHUTDOWN ACK and
3124 * set the T-bit in the Chunk Flags to indicate that the Verification
3125 * Tag is reflected.
1da177e4
LT		 3126 *
3127 * Inputs
3128 * (endpoint, asoc, type, arg, commands)
3129 *
3130 * Outputs
3131 * (sctp_disposition_t)
3132 *
3133 * The return value is the disposition of the chunk.
3134 */
3135static sctp_disposition_t sctp_sf_shut_8_4_5(const struct sctp_endpoint *ep,
3136 const struct sctp_association *asoc,
3137 const sctp_subtype_t type,
3138 void *arg,
3139 sctp_cmd_seq_t *commands)
3140{
3141 struct sctp_packet *packet = NULL;
3142 struct sctp_chunk *chunk = arg;
3143 struct sctp_chunk *shut;
3144
3145 packet = sctp_ootb_pkt_new(asoc, chunk);
3146
3147 if (packet) {
3148 /* Make an SHUTDOWN_COMPLETE.
3149 * The T bit will be set if the asoc is NULL.
3150 */
3151 shut = sctp_make_shutdown_complete(asoc, chunk);
3152 if (!shut) {
3153 sctp_ootb_pkt_free(packet);
3154 return SCTP_DISPOSITION_NOMEM;
3155 }
3156
047a2428
JF		 3157 /* Reflect vtag if T-Bit is set */
3158 if (sctp_test_T_bit(shut))
3159 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3160
1da177e4
LT		 3161 /* Set the skb to the belonging sock for accounting. */
3162 shut->skb->sk = ep->base.sk;
3163
3164 sctp_packet_append_chunk(packet, shut);
3165
3166 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3167 SCTP_PACKET(packet));
3168
3169 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
3170
3171 /* If the chunk length is invalid, we don't want to process
3172 * the reset of the packet.
3173 */
3174 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3175 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3176
3177 return SCTP_DISPOSITION_CONSUME;
3178 }
3179
3180 return SCTP_DISPOSITION_NOMEM;
3181}
3182
3183/*
3184 * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state.
3185 *
3186 * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK
3187 * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the
3188 * procedures in section 8.4 SHOULD be followed, in other words it
3189 * should be treated as an Out Of The Blue packet.
3190 * [This means that we do NOT check the Verification Tag on these
3191 * chunks. --piggy ]
3192 *
3193 */
3194sctp_disposition_t sctp_sf_do_8_5_1_E_sa(const struct sctp_endpoint *ep,
3195 const struct sctp_association *asoc,
3196 const sctp_subtype_t type,
3197 void *arg,
3198 sctp_cmd_seq_t *commands)
3199{
3200 /* Although we do have an association in this case, it corresponds
3201 * to a restarted association. So the packet is treated as an OOTB
3202 * packet and the state function that handles OOTB SHUTDOWN_ACK is
3203 * called with a NULL association.
3204 */
3205 return sctp_sf_shut_8_4_5(ep, NULL, type, arg, commands);
3206}
3207
3208/* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */
3209sctp_disposition_t sctp_sf_do_asconf(const struct sctp_endpoint *ep,
3210 const struct sctp_association *asoc,
3211 const sctp_subtype_t type, void *arg,
3212 sctp_cmd_seq_t *commands)
3213{
3214 struct sctp_chunk *chunk = arg;
3215 struct sctp_chunk *asconf_ack = NULL;
3216 sctp_addiphdr_t *hdr;
3217 __u32 serial;
3218
3219 if (!sctp_vtag_verify(chunk, asoc)) {
3220 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3221 SCTP_NULL());
3222 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3223 }
3224
3225 /* Make sure that the ASCONF ADDIP chunk has a valid length. */
3226 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_addip_chunk_t)))
3227 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3228 commands);
3229
3230 hdr = (sctp_addiphdr_t *)chunk->skb->data;
3231 serial = ntohl(hdr->serial);
3232
3233 /* ADDIP 4.2 C1) Compare the value of the serial number to the value
3234 * the endpoint stored in a new association variable
3235 * 'Peer-Serial-Number'.
3236 */
3237 if (serial == asoc->peer.addip_serial + 1) {
3238 /* ADDIP 4.2 C2) If the value found in the serial number is
3239 * equal to the ('Peer-Serial-Number' + 1), the endpoint MUST
3240 * do V1-V5.
3241 */
3242 asconf_ack = sctp_process_asconf((struct sctp_association *)
3243 asoc, chunk);
3244 if (!asconf_ack)
3245 return SCTP_DISPOSITION_NOMEM;
3246 } else if (serial == asoc->peer.addip_serial) {
3247 /* ADDIP 4.2 C3) If the value found in the serial number is
3248 * equal to the value stored in the 'Peer-Serial-Number'
3249 * IMPLEMENTATION NOTE: As an optimization a receiver may wish
3250 * to save the last ASCONF-ACK for some predetermined period of
3251 * time and instead of re-processing the ASCONF (with the same
3252 * serial number) it may just re-transmit the ASCONF-ACK.
3253 */
3254 if (asoc->addip_last_asconf_ack)
3255 asconf_ack = asoc->addip_last_asconf_ack;
3256 else
3257 return SCTP_DISPOSITION_DISCARD;
3258 } else {
3259 /* ADDIP 4.2 C4) Otherwise, the ASCONF Chunk is discarded since
3260 * it must be either a stale packet or from an attacker.
3261 */
3262 return SCTP_DISPOSITION_DISCARD;
3263 }
3264
3265 /* ADDIP 4.2 C5) In both cases C2 and C3 the ASCONF-ACK MUST be sent
3266 * back to the source address contained in the IP header of the ASCONF
3267 * being responded to.
3268 */
3269 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(asconf_ack));
3270
3271 return SCTP_DISPOSITION_CONSUME;
3272}
3273
3274/*
3275 * ADDIP Section 4.3 General rules for address manipulation
3276 * When building TLV parameters for the ASCONF Chunk that will add or
3277 * delete IP addresses the D0 to D13 rules should be applied:
3278 */
3279sctp_disposition_t sctp_sf_do_asconf_ack(const struct sctp_endpoint *ep,
3280 const struct sctp_association *asoc,
3281 const sctp_subtype_t type, void *arg,
3282 sctp_cmd_seq_t *commands)
3283{
3284 struct sctp_chunk *asconf_ack = arg;
3285 struct sctp_chunk *last_asconf = asoc->addip_last_asconf;
3286 struct sctp_chunk *abort;
3287 sctp_addiphdr_t *addip_hdr;
3288 __u32 sent_serial, rcvd_serial;
3289
3290 if (!sctp_vtag_verify(asconf_ack, asoc)) {
3291 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3292 SCTP_NULL());
3293 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3294 }
3295
3296 /* Make sure that the ADDIP chunk has a valid length. */
3297 if (!sctp_chunk_length_valid(asconf_ack, sizeof(sctp_addip_chunk_t)))
3298 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3299 commands);
3300
3301 addip_hdr = (sctp_addiphdr_t *)asconf_ack->skb->data;
3302 rcvd_serial = ntohl(addip_hdr->serial);
3303
3304 if (last_asconf) {
3305 addip_hdr = (sctp_addiphdr_t *)last_asconf->subh.addip_hdr;
3306 sent_serial = ntohl(addip_hdr->serial);
3307 } else {
3308 sent_serial = asoc->addip_serial - 1;
3309 }
3310
3311 /* D0) If an endpoint receives an ASCONF-ACK that is greater than or
3312 * equal to the next serial number to be used but no ASCONF chunk is
3313 * outstanding the endpoint MUST ABORT the association. Note that a
3314 * sequence number is greater than if it is no more than 2^^31-1
3315 * larger than the current sequence number (using serial arithmetic).
3316 */
3317 if (ADDIP_SERIAL_gte(rcvd_serial, sent_serial + 1) &&
3318 !(asoc->addip_last_asconf)) {
3319 abort = sctp_make_abort(asoc, asconf_ack,
3320 sizeof(sctp_errhdr_t));
3321 if (abort) {
3322 sctp_init_cause(abort, SCTP_ERROR_ASCONF_ACK, NULL, 0);
3323 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3324 SCTP_CHUNK(abort));
3325 }
3326 /* We are going to ABORT, so we might as well stop
3327 * processing the rest of the chunks in the packet.
3328 */
3329 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3330 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3331 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
3332 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
3333 SCTP_U32(SCTP_ERROR_ASCONF_ACK));
3334 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
3335 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3336 return SCTP_DISPOSITION_ABORT;
3337 }
3338
3339 if ((rcvd_serial == sent_serial) && asoc->addip_last_asconf) {
3340 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3341 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3342
3343 if (!sctp_process_asconf_ack((struct sctp_association *)asoc,
3344 asconf_ack))
3345 return SCTP_DISPOSITION_CONSUME;
3346
3347 abort = sctp_make_abort(asoc, asconf_ack,
3348 sizeof(sctp_errhdr_t));
3349 if (abort) {
3350 sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, NULL, 0);
3351 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3352 SCTP_CHUNK(abort));
3353 }
3354 /* We are going to ABORT, so we might as well stop
3355 * processing the rest of the chunks in the packet.
3356 */
3357 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
3358 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
3359 SCTP_U32(SCTP_ERROR_ASCONF_ACK));
3360 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
3361 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3362 return SCTP_DISPOSITION_ABORT;
3363 }
3364
3365 return SCTP_DISPOSITION_DISCARD;
3366}
3367
3368/*
3369 * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP
3370 *
3371 * When a FORWARD TSN chunk arrives, the data receiver MUST first update
3372 * its cumulative TSN point to the value carried in the FORWARD TSN
3373 * chunk, and then MUST further advance its cumulative TSN point locally
3374 * if possible.
3375 * After the above processing, the data receiver MUST stop reporting any
3376 * missing TSNs earlier than or equal to the new cumulative TSN point.
3377 *
3378 * Verification Tag: 8.5 Verification Tag [Normal verification]
3379 *
3380 * The return value is the disposition of the chunk.
3381 */
3382sctp_disposition_t sctp_sf_eat_fwd_tsn(const struct sctp_endpoint *ep,
3383 const struct sctp_association *asoc,
3384 const sctp_subtype_t type,
3385 void *arg,
3386 sctp_cmd_seq_t *commands)
3387{
3388 struct sctp_chunk *chunk = arg;
3389 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
3390 __u16 len;
3391 __u32 tsn;
3392
3393 if (!sctp_vtag_verify(chunk, asoc)) {
3394 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3395 SCTP_NULL());
3396 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3397 }
3398
3399 /* Make sure that the FORWARD_TSN chunk has valid length. */
3400 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
3401 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3402 commands);
3403
3404 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3405 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3406 len = ntohs(chunk->chunk_hdr->length);
3407 len -= sizeof(struct sctp_chunkhdr);
3408 skb_pull(chunk->skb, len);
3409
3410 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
3411 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __FUNCTION__, tsn);
3412
3413 /* The TSN is too high--silently discard the chunk and count on it
3414 * getting retransmitted later.
3415 */
3416 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3417 goto discard_noforce;
3418
3419 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3420 if (len > sizeof(struct sctp_fwdtsn_hdr))
3421 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
3422 SCTP_CHUNK(chunk));
3423
3424 /* Count this as receiving DATA. */
3425 if (asoc->autoclose) {
3426 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3427 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
3428 }
3429
3430 /* FIXME: For now send a SACK, but DATA processing may
3431 * send another.
3432 */
3433 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
3434 /* Start the SACK timer. */
3435 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3436 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
3437
3438 return SCTP_DISPOSITION_CONSUME;
3439
3440discard_noforce:
3441 return SCTP_DISPOSITION_DISCARD;
3442}
3443
3444sctp_disposition_t sctp_sf_eat_fwd_tsn_fast(
3445 const struct sctp_endpoint *ep,
3446 const struct sctp_association *asoc,
3447 const sctp_subtype_t type,
3448 void *arg,
3449 sctp_cmd_seq_t *commands)
3450{
3451 struct sctp_chunk *chunk = arg;
3452 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
3453 __u16 len;
3454 __u32 tsn;
3455
3456 if (!sctp_vtag_verify(chunk, asoc)) {
3457 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3458 SCTP_NULL());
3459 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3460 }
3461
3462 /* Make sure that the FORWARD_TSN chunk has a valid length. */
3463 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
3464 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3465 commands);
3466
3467 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3468 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3469 len = ntohs(chunk->chunk_hdr->length);
3470 len -= sizeof(struct sctp_chunkhdr);
3471 skb_pull(chunk->skb, len);
3472
3473 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
3474 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __FUNCTION__, tsn);
3475
3476 /* The TSN is too high--silently discard the chunk and count on it
3477 * getting retransmitted later.
3478 */
3479 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3480 goto gen_shutdown;
3481
3482 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3483 if (len > sizeof(struct sctp_fwdtsn_hdr))
3484 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
3485 SCTP_CHUNK(chunk));
3486
3487 /* Go a head and force a SACK, since we are shutting down. */
3488gen_shutdown:
3489 /* Implementor's Guide.
3490 *
3491 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3492 * respond to each received packet containing one or more DATA chunk(s)
3493 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3494 */
3495 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
3496 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3497 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3498 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3499
3500 return SCTP_DISPOSITION_CONSUME;
3501}
3502
3503/*
3504 * Process an unknown chunk.
3505 *
3506 * Section: 3.2. Also, 2.1 in the implementor's guide.
3507 *
3508 * Chunk Types are encoded such that the highest-order two bits specify
3509 * the action that must be taken if the processing endpoint does not
3510 * recognize the Chunk Type.
3511 *
3512 * 00 - Stop processing this SCTP packet and discard it, do not process
3513 * any further chunks within it.
3514 *
3515 * 01 - Stop processing this SCTP packet and discard it, do not process
3516 * any further chunks within it, and report the unrecognized
3517 * chunk in an 'Unrecognized Chunk Type'.
3518 *
3519 * 10 - Skip this chunk and continue processing.
3520 *
3521 * 11 - Skip this chunk and continue processing, but report in an ERROR
3522 * Chunk using the 'Unrecognized Chunk Type' cause of error.
3523 *
3524 * The return value is the disposition of the chunk.
3525 */
3526sctp_disposition_t sctp_sf_unk_chunk(const struct sctp_endpoint *ep,
3527 const struct sctp_association *asoc,
3528 const sctp_subtype_t type,
3529 void *arg,
3530 sctp_cmd_seq_t *commands)
3531{
3532 struct sctp_chunk *unk_chunk = arg;
3533 struct sctp_chunk *err_chunk;
3534 sctp_chunkhdr_t *hdr;
3535
3536 SCTP_DEBUG_PRINTK("Processing the unknown chunk id %d.\n", type.chunk);
3537
3538 if (!sctp_vtag_verify(unk_chunk, asoc))
3539 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3540
3541 /* Make sure that the chunk has a valid length.
3542 * Since we don't know the chunk type, we use a general
3543 * chunkhdr structure to make a comparison.
3544 */
3545 if (!sctp_chunk_length_valid(unk_chunk, sizeof(sctp_chunkhdr_t)))
3546 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3547 commands);
3548
3549 switch (type.chunk & SCTP_CID_ACTION_MASK) {
3550 case SCTP_CID_ACTION_DISCARD:
3551 /* Discard the packet. */
3552 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3553 break;
3554 case SCTP_CID_ACTION_DISCARD_ERR:
3555 /* Discard the packet. */
3556 sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3557
3558 /* Generate an ERROR chunk as response. */
3559 hdr = unk_chunk->chunk_hdr;
3560 err_chunk = sctp_make_op_error(asoc, unk_chunk,
3561 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
3562 WORD_ROUND(ntohs(hdr->length)));
3563 if (err_chunk) {
3564 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3565 SCTP_CHUNK(err_chunk));
3566 }
3567 return SCTP_DISPOSITION_CONSUME;
3568 break;
3569 case SCTP_CID_ACTION_SKIP:
3570 /* Skip the chunk. */
3571 return SCTP_DISPOSITION_DISCARD;
3572 break;
3573 case SCTP_CID_ACTION_SKIP_ERR:
3574 /* Generate an ERROR chunk as response. */
3575 hdr = unk_chunk->chunk_hdr;
3576 err_chunk = sctp_make_op_error(asoc, unk_chunk,
3577 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
3578 WORD_ROUND(ntohs(hdr->length)));
3579 if (err_chunk) {
3580 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3581 SCTP_CHUNK(err_chunk));
3582 }
3583 /* Skip the chunk. */
3584 return SCTP_DISPOSITION_CONSUME;
3585 break;
3586 default:
3587 break;
3588 }
3589
3590 return SCTP_DISPOSITION_DISCARD;
3591}
3592
3593/*
3594 * Discard the chunk.
3595 *
3596 * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2
3597 * [Too numerous to mention...]
3598 * Verification Tag: No verification needed.
3599 * Inputs
3600 * (endpoint, asoc, chunk)
3601 *
3602 * Outputs
3603 * (asoc, reply_msg, msg_up, timers, counters)
3604 *
3605 * The return value is the disposition of the chunk.
3606 */
3607sctp_disposition_t sctp_sf_discard_chunk(const struct sctp_endpoint *ep,
3608 const struct sctp_association *asoc,
3609 const sctp_subtype_t type,
3610 void *arg,
3611 sctp_cmd_seq_t *commands)
3612{
3613 SCTP_DEBUG_PRINTK("Chunk %d is discarded\n", type.chunk);
3614 return SCTP_DISPOSITION_DISCARD;
3615}
3616
3617/*
3618 * Discard the whole packet.
3619 *
3620 * Section: 8.4 2)
3621 *
3622 * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST
3623 * silently discard the OOTB packet and take no further action.
1da177e4
LT		 3624 *
3625 * Verification Tag: No verification necessary
3626 *
3627 * Inputs
3628 * (endpoint, asoc, chunk)
3629 *
3630 * Outputs
3631 * (asoc, reply_msg, msg_up, timers, counters)
3632 *
3633 * The return value is the disposition of the chunk.
3634 */
3635sctp_disposition_t sctp_sf_pdiscard(const struct sctp_endpoint *ep,
3636 const struct sctp_association *asoc,
3637 const sctp_subtype_t type,
3638 void *arg,
3639 sctp_cmd_seq_t *commands)
3640{
3641 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
3642
3643 return SCTP_DISPOSITION_CONSUME;
3644}
3645
3646
3647/*
3648 * The other end is violating protocol.
3649 *
3650 * Section: Not specified
3651 * Verification Tag: Not specified
3652 * Inputs
3653 * (endpoint, asoc, chunk)
3654 *
3655 * Outputs
3656 * (asoc, reply_msg, msg_up, timers, counters)
3657 *
3658 * We simply tag the chunk as a violation. The state machine will log
3659 * the violation and continue.
3660 */
3661sctp_disposition_t sctp_sf_violation(const struct sctp_endpoint *ep,
3662 const struct sctp_association *asoc,
3663 const sctp_subtype_t type,
3664 void *arg,
3665 sctp_cmd_seq_t *commands)
3666{
3667 return SCTP_DISPOSITION_VIOLATION;
3668}
3669
3670
3671/*
3672 * Handle a protocol violation when the chunk length is invalid.
3673 * "Invalid" length is identified as smaller then the minimal length a
3674 * given chunk can be. For example, a SACK chunk has invalid length
3675 * if it's length is set to be smaller then the size of sctp_sack_chunk_t.
3676 *
3677 * We inform the other end by sending an ABORT with a Protocol Violation
3678 * error code.
3679 *
3680 * Section: Not specified
3681 * Verification Tag: Nothing to do
3682 * Inputs
3683 * (endpoint, asoc, chunk)
3684 *
3685 * Outputs
3686 * (reply_msg, msg_up, counters)
3687 *
3688 * Generate an ABORT chunk and terminate the association.
3689 */
3690sctp_disposition_t sctp_sf_violation_chunklen(const struct sctp_endpoint *ep,
3691 const struct sctp_association *asoc,
3692 const sctp_subtype_t type,
3693 void *arg,
3694 sctp_cmd_seq_t *commands)
3695{
3696 struct sctp_chunk *chunk = arg;
3697 struct sctp_chunk *abort = NULL;
3698 char err_str[]="The following chunk had invalid length:";
3699
3700 /* Make the abort chunk. */
3701 abort = sctp_make_abort_violation(asoc, chunk, err_str,
3702 sizeof(err_str));
3703 if (!abort)
3704 goto nomem;
3705
3706 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
3707 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
3708
3709 if (asoc->state <= SCTP_STATE_COOKIE_ECHOED) {
3710 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3711 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
3712 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
3713 SCTP_U32(SCTP_ERROR_PROTO_VIOLATION));
3714 } else {
3715 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
3716 SCTP_U32(SCTP_ERROR_PROTO_VIOLATION));
3717 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3718 }
3719
3720 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
3721
3722 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
3723
3724 return SCTP_DISPOSITION_ABORT;
3725
3726nomem:
3727 return SCTP_DISPOSITION_NOMEM;
3728}
3729
3730/***************************************************************************
3731 * These are the state functions for handling primitive (Section 10) events.
3732 ***************************************************************************/
3733/*
3734 * sctp_sf_do_prm_asoc
3735 *
3736 * Section: 10.1 ULP-to-SCTP
3737 * B) Associate
3738 *
3739 * Format: ASSOCIATE(local SCTP instance name, destination transport addr,
3740 * outbound stream count)
3741 * -> association id [,destination transport addr list] [,outbound stream
3742 * count]
3743 *
3744 * This primitive allows the upper layer to initiate an association to a
3745 * specific peer endpoint.
3746 *
3747 * The peer endpoint shall be specified by one of the transport addresses
3748 * which defines the endpoint (see Section 1.4). If the local SCTP
3749 * instance has not been initialized, the ASSOCIATE is considered an
3750 * error.
3751 * [This is not relevant for the kernel implementation since we do all
3752 * initialization at boot time. It we hadn't initialized we wouldn't
3753 * get anywhere near this code.]
3754 *
3755 * An association id, which is a local handle to the SCTP association,
3756 * will be returned on successful establishment of the association. If
3757 * SCTP is not able to open an SCTP association with the peer endpoint,
3758 * an error is returned.
3759 * [In the kernel implementation, the struct sctp_association needs to
3760 * be created BEFORE causing this primitive to run.]
3761 *
3762 * Other association parameters may be returned, including the
3763 * complete destination transport addresses of the peer as well as the
3764 * outbound stream count of the local endpoint. One of the transport
3765 * address from the returned destination addresses will be selected by
3766 * the local endpoint as default primary path for sending SCTP packets
3767 * to this peer. The returned "destination transport addr list" can
3768 * be used by the ULP to change the default primary path or to force
3769 * sending a packet to a specific transport address. [All of this
3770 * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING
3771 * function.]
3772 *
3773 * Mandatory attributes:
3774 *
3775 * o local SCTP instance name - obtained from the INITIALIZE operation.
3776 * [This is the argument asoc.]
3777 * o destination transport addr - specified as one of the transport
3778 * addresses of the peer endpoint with which the association is to be
3779 * established.
3780 * [This is asoc->peer.active_path.]
3781 * o outbound stream count - the number of outbound streams the ULP
3782 * would like to open towards this peer endpoint.
3783 * [BUG: This is not currently implemented.]
3784 * Optional attributes:
3785 *
3786 * None.
3787 *
3788 * The return value is a disposition.
3789 */
3790sctp_disposition_t sctp_sf_do_prm_asoc(const struct sctp_endpoint *ep,
3791 const struct sctp_association *asoc,
3792 const sctp_subtype_t type,
3793 void *arg,
3794 sctp_cmd_seq_t *commands)
3795{
3796 struct sctp_chunk *repl;
3797
3798 /* The comment below says that we enter COOKIE-WAIT AFTER
3799 * sending the INIT, but that doesn't actually work in our
3800 * implementation...
3801 */
3802 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3803 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
3804
3805 /* RFC 2960 5.1 Normal Establishment of an Association
3806 *
3807 * A) "A" first sends an INIT chunk to "Z". In the INIT, "A"
3808 * must provide its Verification Tag (Tag_A) in the Initiate
3809 * Tag field. Tag_A SHOULD be a random number in the range of
3810 * 1 to 4294967295 (see 5.3.1 for Tag value selection). ...
3811 */
3812
3813 repl = sctp_make_init(asoc, &asoc->base.bind_addr, GFP_ATOMIC, 0);
3814 if (!repl)
3815 goto nomem;
3816
3817 /* Cast away the const modifier, as we want to just
3818 * rerun it through as a sideffect.
3819 */
3820 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC,
3821 SCTP_ASOC((struct sctp_association *) asoc));
3822
3f7a87d2
FF		 3823 /* Choose transport for INIT. */
3824 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
3825 SCTP_CHUNK(repl));
3826
1da177e4
LT		 3827 /* After sending the INIT, "A" starts the T1-init timer and
3828 * enters the COOKIE-WAIT state.
3829 */
3830 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
3831 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
3832 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
3833 return SCTP_DISPOSITION_CONSUME;
3834
3835nomem:
3836 return SCTP_DISPOSITION_NOMEM;
3837}
3838
3839/*
3840 * Process the SEND primitive.
3841 *
3842 * Section: 10.1 ULP-to-SCTP
3843 * E) Send
3844 *
3845 * Format: SEND(association id, buffer address, byte count [,context]
3846 * [,stream id] [,life time] [,destination transport address]
3847 * [,unorder flag] [,no-bundle flag] [,payload protocol-id] )
3848 * -> result
3849 *
3850 * This is the main method to send user data via SCTP.
3851 *
3852 * Mandatory attributes:
3853 *
3854 * o association id - local handle to the SCTP association
3855 *
3856 * o buffer address - the location where the user message to be
3857 * transmitted is stored;
3858 *
3859 * o byte count - The size of the user data in number of bytes;
3860 *
3861 * Optional attributes:
3862 *
3863 * o context - an optional 32 bit integer that will be carried in the
3864 * sending failure notification to the ULP if the transportation of
3865 * this User Message fails.
3866 *
3867 * o stream id - to indicate which stream to send the data on. If not
3868 * specified, stream 0 will be used.
3869 *
3870 * o life time - specifies the life time of the user data. The user data
3871 * will not be sent by SCTP after the life time expires. This
3872 * parameter can be used to avoid efforts to transmit stale
3873 * user messages. SCTP notifies the ULP if the data cannot be
3874 * initiated to transport (i.e. sent to the destination via SCTP's
3875 * send primitive) within the life time variable. However, the
3876 * user data will be transmitted if SCTP has attempted to transmit a
3877 * chunk before the life time expired.
3878 *
3879 * o destination transport address - specified as one of the destination
3880 * transport addresses of the peer endpoint to which this packet
3881 * should be sent. Whenever possible, SCTP should use this destination
3882 * transport address for sending the packets, instead of the current
3883 * primary path.
3884 *
3885 * o unorder flag - this flag, if present, indicates that the user
3886 * would like the data delivered in an unordered fashion to the peer
3887 * (i.e., the U flag is set to 1 on all DATA chunks carrying this
3888 * message).
3889 *
3890 * o no-bundle flag - instructs SCTP not to bundle this user data with
3891 * other outbound DATA chunks. SCTP MAY still bundle even when
3892 * this flag is present, when faced with network congestion.
3893 *
3894 * o payload protocol-id - A 32 bit unsigned integer that is to be
3895 * passed to the peer indicating the type of payload protocol data
3896 * being transmitted. This value is passed as opaque data by SCTP.
3897 *
3898 * The return value is the disposition.
3899 */
3900sctp_disposition_t sctp_sf_do_prm_send(const struct sctp_endpoint *ep,
3901 const struct sctp_association *asoc,
3902 const sctp_subtype_t type,
3903 void *arg,
3904 sctp_cmd_seq_t *commands)
3905{
3906 struct sctp_chunk *chunk = arg;
3907
3908 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
3909 return SCTP_DISPOSITION_CONSUME;
3910}
3911
3912/*
3913 * Process the SHUTDOWN primitive.
3914 *
3915 * Section: 10.1:
3916 * C) Shutdown
3917 *
3918 * Format: SHUTDOWN(association id)
3919 * -> result
3920 *
3921 * Gracefully closes an association. Any locally queued user data
3922 * will be delivered to the peer. The association will be terminated only
3923 * after the peer acknowledges all the SCTP packets sent. A success code
3924 * will be returned on successful termination of the association. If
3925 * attempting to terminate the association results in a failure, an error
3926 * code shall be returned.
3927 *
3928 * Mandatory attributes:
3929 *
3930 * o association id - local handle to the SCTP association
3931 *
3932 * Optional attributes:
3933 *
3934 * None.
3935 *
3936 * The return value is the disposition.
3937 */
3938sctp_disposition_t sctp_sf_do_9_2_prm_shutdown(
3939 const struct sctp_endpoint *ep,
3940 const struct sctp_association *asoc,
3941 const sctp_subtype_t type,
3942 void *arg,
3943 sctp_cmd_seq_t *commands)
3944{
3945 int disposition;
3946
3947 /* From 9.2 Shutdown of an Association
3948 * Upon receipt of the SHUTDOWN primitive from its upper
3949 * layer, the endpoint enters SHUTDOWN-PENDING state and
3950 * remains there until all outstanding data has been
3951 * acknowledged by its peer. The endpoint accepts no new data
3952 * from its upper layer, but retransmits data to the far end
3953 * if necessary to fill gaps.
3954 */
3955 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3956 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
3957
3958 /* sctpimpguide-05 Section 2.12.2
3959 * The sender of the SHUTDOWN MAY also start an overall guard timer
3960 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
3961 */
3962 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
3963 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
3964
3965 disposition = SCTP_DISPOSITION_CONSUME;
3966 if (sctp_outq_is_empty(&asoc->outqueue)) {
3967 disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type,
3968 arg, commands);
3969 }
3970 return disposition;
3971}
3972
3973/*
3974 * Process the ABORT primitive.
3975 *
3976 * Section: 10.1:
3977 * C) Abort
3978 *
3979 * Format: Abort(association id [, cause code])
3980 * -> result
3981 *
3982 * Ungracefully closes an association. Any locally queued user data
3983 * will be discarded and an ABORT chunk is sent to the peer. A success code
3984 * will be returned on successful abortion of the association. If
3985 * attempting to abort the association results in a failure, an error
3986 * code shall be returned.
3987 *
3988 * Mandatory attributes:
3989 *
3990 * o association id - local handle to the SCTP association
3991 *
3992 * Optional attributes:
3993 *
3994 * o cause code - reason of the abort to be passed to the peer
3995 *
3996 * None.
3997 *
3998 * The return value is the disposition.
3999 */
4000sctp_disposition_t sctp_sf_do_9_1_prm_abort(
4001 const struct sctp_endpoint *ep,
4002 const struct sctp_association *asoc,
4003 const sctp_subtype_t type,
4004 void *arg,
4005 sctp_cmd_seq_t *commands)
4006{
4007 /* From 9.1 Abort of an Association
4008 * Upon receipt of the ABORT primitive from its upper
4009 * layer, the endpoint enters CLOSED state and
4010 * discard all outstanding data has been
4011 * acknowledged by its peer. The endpoint accepts no new data
4012 * from its upper layer, but retransmits data to the far end
4013 * if necessary to fill gaps.
4014 */
4015 struct msghdr *msg = arg;
4016 struct sctp_chunk *abort;
4017 sctp_disposition_t retval;
4018
4019 retval = SCTP_DISPOSITION_CONSUME;
4020
4021 /* Generate ABORT chunk to send the peer. */
4022 abort = sctp_make_abort_user(asoc, NULL, msg);
4023 if (!abort)
4024 retval = SCTP_DISPOSITION_NOMEM;
4025 else
4026 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4027
4028 /* Even if we can't send the ABORT due to low memory delete the
4029 * TCB. This is a departure from our typical NOMEM handling.
4030 */
4031
4032 /* Delete the established association. */
4033 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4034 SCTP_U32(SCTP_ERROR_USER_ABORT));
4035
4036 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4037 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
4038
4039 return retval;
4040}
4041
4042/* We tried an illegal operation on an association which is closed. */
4043sctp_disposition_t sctp_sf_error_closed(const struct sctp_endpoint *ep,
4044 const struct sctp_association *asoc,
4045 const sctp_subtype_t type,
4046 void *arg,
4047 sctp_cmd_seq_t *commands)
4048{
4049 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, SCTP_ERROR(-EINVAL));
4050 return SCTP_DISPOSITION_CONSUME;
4051}
4052
4053/* We tried an illegal operation on an association which is shutting
4054 * down.
4055 */
4056sctp_disposition_t sctp_sf_error_shutdown(const struct sctp_endpoint *ep,
4057 const struct sctp_association *asoc,
4058 const sctp_subtype_t type,
4059 void *arg,
4060 sctp_cmd_seq_t *commands)
4061{
4062 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR,
4063 SCTP_ERROR(-ESHUTDOWN));
4064 return SCTP_DISPOSITION_CONSUME;
4065}
4066
4067/*
4068 * sctp_cookie_wait_prm_shutdown
4069 *
4070 * Section: 4 Note: 2
4071 * Verification Tag:
4072 * Inputs
4073 * (endpoint, asoc)
4074 *
4075 * The RFC does not explicitly address this issue, but is the route through the
4076 * state table when someone issues a shutdown while in COOKIE_WAIT state.
4077 *
4078 * Outputs
4079 * (timers)
4080 */
4081sctp_disposition_t sctp_sf_cookie_wait_prm_shutdown(
4082 const struct sctp_endpoint *ep,
4083 const struct sctp_association *asoc,
4084 const sctp_subtype_t type,
4085 void *arg,
4086 sctp_cmd_seq_t *commands)
4087{
4088 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4089 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4090
4091 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4092 SCTP_STATE(SCTP_STATE_CLOSED));
4093
4094 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
4095
4096 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
4097
4098 return SCTP_DISPOSITION_DELETE_TCB;
4099}
4100
4101/*
4102 * sctp_cookie_echoed_prm_shutdown
4103 *
4104 * Section: 4 Note: 2
4105 * Verification Tag:
4106 * Inputs
4107 * (endpoint, asoc)
4108 *
4109 * The RFC does not explcitly address this issue, but is the route through the
4110 * state table when someone issues a shutdown while in COOKIE_ECHOED state.
4111 *
4112 * Outputs
4113 * (timers)
4114 */
4115sctp_disposition_t sctp_sf_cookie_echoed_prm_shutdown(
4116 const struct sctp_endpoint *ep,
4117 const struct sctp_association *asoc,
4118 const sctp_subtype_t type,
4119 void *arg, sctp_cmd_seq_t *commands)
4120{
4121 /* There is a single T1 timer, so we should be able to use
4122 * common function with the COOKIE-WAIT state.
4123 */
4124 return sctp_sf_cookie_wait_prm_shutdown(ep, asoc, type, arg, commands);
4125}
4126
4127/*
4128 * sctp_sf_cookie_wait_prm_abort
4129 *
4130 * Section: 4 Note: 2
4131 * Verification Tag:
4132 * Inputs
4133 * (endpoint, asoc)
4134 *
4135 * The RFC does not explicitly address this issue, but is the route through the
4136 * state table when someone issues an abort while in COOKIE_WAIT state.
4137 *
4138 * Outputs
4139 * (timers)
4140 */
4141sctp_disposition_t sctp_sf_cookie_wait_prm_abort(
4142 const struct sctp_endpoint *ep,
4143 const struct sctp_association *asoc,
4144 const sctp_subtype_t type,
4145 void *arg,
4146 sctp_cmd_seq_t *commands)
4147{
4148 struct msghdr *msg = arg;
4149 struct sctp_chunk *abort;
4150 sctp_disposition_t retval;
4151
4152 /* Stop T1-init timer */
4153 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4154 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4155 retval = SCTP_DISPOSITION_CONSUME;
4156
4157 /* Generate ABORT chunk to send the peer */
4158 abort = sctp_make_abort_user(asoc, NULL, msg);
4159 if (!abort)
4160 retval = SCTP_DISPOSITION_NOMEM;
4161 else
4162 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4163
4164 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4165 SCTP_STATE(SCTP_STATE_CLOSED));
4166
4167 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4168
4169 /* Even if we can't send the ABORT due to low memory delete the
4170 * TCB. This is a departure from our typical NOMEM handling.
4171 */
4172
4173 /* Delete the established association. */
4174 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
4175 SCTP_U32(SCTP_ERROR_USER_ABORT));
4176
4177 return retval;
4178}
4179
4180/*
4181 * sctp_sf_cookie_echoed_prm_abort
4182 *
4183 * Section: 4 Note: 3
4184 * Verification Tag:
4185 * Inputs
4186 * (endpoint, asoc)
4187 *
4188 * The RFC does not explcitly address this issue, but is the route through the
4189 * state table when someone issues an abort while in COOKIE_ECHOED state.
4190 *
4191 * Outputs
4192 * (timers)
4193 */
4194sctp_disposition_t sctp_sf_cookie_echoed_prm_abort(
4195 const struct sctp_endpoint *ep,
4196 const struct sctp_association *asoc,
4197 const sctp_subtype_t type,
4198 void *arg,
4199 sctp_cmd_seq_t *commands)
4200{
4201 /* There is a single T1 timer, so we should be able to use
4202 * common function with the COOKIE-WAIT state.
4203 */
4204 return sctp_sf_cookie_wait_prm_abort(ep, asoc, type, arg, commands);
4205}
4206
4207/*
4208 * sctp_sf_shutdown_pending_prm_abort
4209 *
4210 * Inputs
4211 * (endpoint, asoc)
4212 *
4213 * The RFC does not explicitly address this issue, but is the route through the
4214 * state table when someone issues an abort while in SHUTDOWN-PENDING state.
4215 *
4216 * Outputs
4217 * (timers)
4218 */
4219sctp_disposition_t sctp_sf_shutdown_pending_prm_abort(
4220 const struct sctp_endpoint *ep,
4221 const struct sctp_association *asoc,
4222 const sctp_subtype_t type,
4223 void *arg,
4224 sctp_cmd_seq_t *commands)
4225{
4226 /* Stop the T5-shutdown guard timer. */
4227 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4228 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4229
4230 return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands);
4231}
4232
4233/*
4234 * sctp_sf_shutdown_sent_prm_abort
4235 *
4236 * Inputs
4237 * (endpoint, asoc)
4238 *
4239 * The RFC does not explicitly address this issue, but is the route through the
4240 * state table when someone issues an abort while in SHUTDOWN-SENT state.
4241 *
4242 * Outputs
4243 * (timers)
4244 */
4245sctp_disposition_t sctp_sf_shutdown_sent_prm_abort(
4246 const struct sctp_endpoint *ep,
4247 const struct sctp_association *asoc,
4248 const sctp_subtype_t type,
4249 void *arg,
4250 sctp_cmd_seq_t *commands)
4251{
4252 /* Stop the T2-shutdown timer. */
4253 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4254 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4255
4256 /* Stop the T5-shutdown guard timer. */
4257 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4258 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4259
4260 return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands);
4261}
4262
4263/*
4264 * sctp_sf_cookie_echoed_prm_abort
4265 *
4266 * Inputs
4267 * (endpoint, asoc)
4268 *
4269 * The RFC does not explcitly address this issue, but is the route through the
4270 * state table when someone issues an abort while in COOKIE_ECHOED state.
4271 *
4272 * Outputs
4273 * (timers)
4274 */
4275sctp_disposition_t sctp_sf_shutdown_ack_sent_prm_abort(
4276 const struct sctp_endpoint *ep,
4277 const struct sctp_association *asoc,
4278 const sctp_subtype_t type,
4279 void *arg,
4280 sctp_cmd_seq_t *commands)
4281{
4282 /* The same T2 timer, so we should be able to use
4283 * common function with the SHUTDOWN-SENT state.
4284 */
4285 return sctp_sf_shutdown_sent_prm_abort(ep, asoc, type, arg, commands);
4286}
4287
4288/*
4289 * Process the REQUESTHEARTBEAT primitive
4290 *
4291 * 10.1 ULP-to-SCTP
4292 * J) Request Heartbeat
4293 *
4294 * Format: REQUESTHEARTBEAT(association id, destination transport address)
4295 *
4296 * -> result
4297 *
4298 * Instructs the local endpoint to perform a HeartBeat on the specified
4299 * destination transport address of the given association. The returned
4300 * result should indicate whether the transmission of the HEARTBEAT
4301 * chunk to the destination address is successful.
4302 *
4303 * Mandatory attributes:
4304 *
4305 * o association id - local handle to the SCTP association
4306 *
4307 * o destination transport address - the transport address of the
4308 * association on which a heartbeat should be issued.
4309 */
4310sctp_disposition_t sctp_sf_do_prm_requestheartbeat(
4311 const struct sctp_endpoint *ep,
4312 const struct sctp_association *asoc,
4313 const sctp_subtype_t type,
4314 void *arg,
4315 sctp_cmd_seq_t *commands)
4316{
4317 return sctp_sf_heartbeat(ep, asoc, type, (struct sctp_transport *)arg,
4318 commands);
4319}
4320
4321/*
4322 * ADDIP Section 4.1 ASCONF Chunk Procedures
4323 * When an endpoint has an ASCONF signaled change to be sent to the
4324 * remote endpoint it should do A1 to A9
4325 */
4326sctp_disposition_t sctp_sf_do_prm_asconf(const struct sctp_endpoint *ep,
4327 const struct sctp_association *asoc,
4328 const sctp_subtype_t type,
4329 void *arg,
4330 sctp_cmd_seq_t *commands)
4331{
4332 struct sctp_chunk *chunk = arg;
4333
4334 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
4335 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4336 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
4337 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
4338 return SCTP_DISPOSITION_CONSUME;
4339}
4340
4341/*
4342 * Ignore the primitive event
4343 *
4344 * The return value is the disposition of the primitive.
4345 */
4346sctp_disposition_t sctp_sf_ignore_primitive(
4347 const struct sctp_endpoint *ep,
4348 const struct sctp_association *asoc,
4349 const sctp_subtype_t type,
4350 void *arg,
4351 sctp_cmd_seq_t *commands)
4352{
4353 SCTP_DEBUG_PRINTK("Primitive type %d is ignored.\n", type.primitive);
4354 return SCTP_DISPOSITION_DISCARD;
4355}
4356
4357/***************************************************************************
4358 * These are the state functions for the OTHER events.
4359 ***************************************************************************/
4360
4361/*
4362 * Start the shutdown negotiation.
4363 *
4364 * From Section 9.2:
4365 * Once all its outstanding data has been acknowledged, the endpoint
4366 * shall send a SHUTDOWN chunk to its peer including in the Cumulative
4367 * TSN Ack field the last sequential TSN it has received from the peer.
4368 * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT
4369 * state. If the timer expires, the endpoint must re-send the SHUTDOWN
4370 * with the updated last sequential TSN received from its peer.
4371 *
4372 * The return value is the disposition.
4373 */
4374sctp_disposition_t sctp_sf_do_9_2_start_shutdown(
4375 const struct sctp_endpoint *ep,
4376 const struct sctp_association *asoc,
4377 const sctp_subtype_t type,
4378 void *arg,
4379 sctp_cmd_seq_t *commands)
4380{
4381 struct sctp_chunk *reply;
4382
4383 /* Once all its outstanding data has been acknowledged, the
4384 * endpoint shall send a SHUTDOWN chunk to its peer including
4385 * in the Cumulative TSN Ack field the last sequential TSN it
4386 * has received from the peer.
4387 */
4388 reply = sctp_make_shutdown(asoc, NULL);
4389 if (!reply)
4390 goto nomem;
4391
4392 /* Set the transport for the SHUTDOWN chunk and the timeout for the
4393 * T2-shutdown timer.
4394 */
4395 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
4396
4397 /* It shall then start the T2-shutdown timer */
4398 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4399 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4400
4401 if (asoc->autoclose)
4402 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4403 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
4404
4405 /* and enter the SHUTDOWN-SENT state. */
4406 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4407 SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT));
4408
4409 /* sctp-implguide 2.10 Issues with Heartbeating and failover
4410 *
4411 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
4412 * or SHUTDOWN-ACK.
4413 */
4414 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
4415
4416 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
4417
4418 return SCTP_DISPOSITION_CONSUME;
4419
4420nomem:
4421 return SCTP_DISPOSITION_NOMEM;
4422}
4423
4424/*
4425 * Generate a SHUTDOWN ACK now that everything is SACK'd.
4426 *
4427 * From Section 9.2:
4428 *
4429 * If it has no more outstanding DATA chunks, the SHUTDOWN receiver
4430 * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own,
4431 * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the
4432 * endpoint must re-send the SHUTDOWN ACK.
4433 *
4434 * The return value is the disposition.
4435 */
4436sctp_disposition_t sctp_sf_do_9_2_shutdown_ack(
4437 const struct sctp_endpoint *ep,
4438 const struct sctp_association *asoc,
4439 const sctp_subtype_t type,
4440 void *arg,
4441 sctp_cmd_seq_t *commands)
4442{
4443 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
4444 struct sctp_chunk *reply;
4445
4446 /* There are 2 ways of getting here:
4447 * 1) called in response to a SHUTDOWN chunk
4448 * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued.
4449 *
4450 * For the case (2), the arg parameter is set to NULL. We need
4451 * to check that we have a chunk before accessing it's fields.
4452 */
4453 if (chunk) {
4454 if (!sctp_vtag_verify(chunk, asoc))
4455 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
4456
4457 /* Make sure that the SHUTDOWN chunk has a valid length. */
4458 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_shutdown_chunk_t)))
4459 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
4460 commands);
4461 }
4462
4463 /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
4464 * shall send a SHUTDOWN ACK ...
4465 */
4466 reply = sctp_make_shutdown_ack(asoc, chunk);
4467 if (!reply)
4468 goto nomem;
4469
4470 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
4471 * the T2-shutdown timer.
4472 */
4473 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
4474
4475 /* and start/restart a T2-shutdown timer of its own, */
4476 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
4477 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4478
4479 if (asoc->autoclose)
4480 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4481 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
4482
4483 /* Enter the SHUTDOWN-ACK-SENT state. */
4484 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4485 SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT));
4486
4487 /* sctp-implguide 2.10 Issues with Heartbeating and failover
4488 *
4489 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
4490 * or SHUTDOWN-ACK.
4491 */
4492 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
4493
4494 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
4495
4496 return SCTP_DISPOSITION_CONSUME;
4497
4498nomem:
4499 return SCTP_DISPOSITION_NOMEM;
4500}
4501
4502/*
4503 * Ignore the event defined as other
4504 *
4505 * The return value is the disposition of the event.
4506 */
4507sctp_disposition_t sctp_sf_ignore_other(const struct sctp_endpoint *ep,
4508 const struct sctp_association *asoc,
4509 const sctp_subtype_t type,
4510 void *arg,
4511 sctp_cmd_seq_t *commands)
4512{
4513 SCTP_DEBUG_PRINTK("The event other type %d is ignored\n", type.other);
4514 return SCTP_DISPOSITION_DISCARD;
4515}
4516
4517/************************************************************
4518 * These are the state functions for handling timeout events.
4519 ************************************************************/
4520
4521/*
4522 * RTX Timeout
4523 *
4524 * Section: 6.3.3 Handle T3-rtx Expiration
4525 *
4526 * Whenever the retransmission timer T3-rtx expires for a destination
4527 * address, do the following:
4528 * [See below]
4529 *
4530 * The return value is the disposition of the chunk.
4531 */
4532sctp_disposition_t sctp_sf_do_6_3_3_rtx(const struct sctp_endpoint *ep,
4533 const struct sctp_association *asoc,
4534 const sctp_subtype_t type,
4535 void *arg,
4536 sctp_cmd_seq_t *commands)
4537{
4538 struct sctp_transport *transport = arg;
4539
4540 if (asoc->overall_error_count >= asoc->max_retrans) {
4541 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
4542 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4543 SCTP_U32(SCTP_ERROR_NO_ERROR));
4544 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4545 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
4546 return SCTP_DISPOSITION_DELETE_TCB;
4547 }
4548
4549 /* E1) For the destination address for which the timer
4550 * expires, adjust its ssthresh with rules defined in Section
4551 * 7.2.3 and set the cwnd <- MTU.
4552 */
4553
4554 /* E2) For the destination address for which the timer
4555 * expires, set RTO <- RTO * 2 ("back off the timer"). The
4556 * maximum value discussed in rule C7 above (RTO.max) may be
4557 * used to provide an upper bound to this doubling operation.
4558 */
4559
4560 /* E3) Determine how many of the earliest (i.e., lowest TSN)
4561 * outstanding DATA chunks for the address for which the
4562 * T3-rtx has expired will fit into a single packet, subject
4563 * to the MTU constraint for the path corresponding to the
4564 * destination transport address to which the retransmission
4565 * is being sent (this may be different from the address for
4566 * which the timer expires [see Section 6.4]). Call this
4567 * value K. Bundle and retransmit those K DATA chunks in a
4568 * single packet to the destination endpoint.
4569 *
4570 * Note: Any DATA chunks that were sent to the address for
4571 * which the T3-rtx timer expired but did not fit in one MTU
4572 * (rule E3 above), should be marked for retransmission and
4573 * sent as soon as cwnd allows (normally when a SACK arrives).
4574 */
4575
4576 /* NB: Rules E4 and F1 are implicit in R1. */
4577 sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN, SCTP_TRANSPORT(transport));
4578
4579 /* Do some failure management (Section 8.2). */
4580 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
4581
4582 return SCTP_DISPOSITION_CONSUME;
4583}
4584
4585/*
4586 * Generate delayed SACK on timeout
4587 *
4588 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
4589 *
4590 * The guidelines on delayed acknowledgement algorithm specified in
4591 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
4592 * acknowledgement SHOULD be generated for at least every second packet
4593 * (not every second DATA chunk) received, and SHOULD be generated
4594 * within 200 ms of the arrival of any unacknowledged DATA chunk. In
4595 * some situations it may be beneficial for an SCTP transmitter to be
4596 * more conservative than the algorithms detailed in this document
4597 * allow. However, an SCTP transmitter MUST NOT be more aggressive than
4598 * the following algorithms allow.
4599 */
4600sctp_disposition_t sctp_sf_do_6_2_sack(const struct sctp_endpoint *ep,
4601 const struct sctp_association *asoc,
4602 const sctp_subtype_t type,
4603 void *arg,
4604 sctp_cmd_seq_t *commands)
4605{
4606 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
4607 return SCTP_DISPOSITION_CONSUME;
4608}
4609
4610/*
3f7a87d2 4611 * sctp_sf_t1_init_timer_expire
1da177e4
LT		 4612 *
4613 * Section: 4 Note: 2
4614 * Verification Tag:
4615 * Inputs
4616 * (endpoint, asoc)
4617 *
4618 * RFC 2960 Section 4 Notes
4619 * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT
4620 * and re-start the T1-init timer without changing state. This MUST
4621 * be repeated up to 'Max.Init.Retransmits' times. After that, the
4622 * endpoint MUST abort the initialization process and report the
4623 * error to SCTP user.
4624 *
3f7a87d2
FF		 4625 * Outputs
4626 * (timers, events)
4627 *
4628 */
4629sctp_disposition_t sctp_sf_t1_init_timer_expire(const struct sctp_endpoint *ep,
4630 const struct sctp_association *asoc,
4631 const sctp_subtype_t type,
4632 void *arg,
4633 sctp_cmd_seq_t *commands)
4634{
4635 struct sctp_chunk *repl = NULL;
4636 struct sctp_bind_addr *bp;
4637 int attempts = asoc->init_err_counter + 1;
4638
4639 SCTP_DEBUG_PRINTK("Timer T1 expired (INIT).\n");
4640
4641 if (attempts < asoc->max_init_attempts) {
4642 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
4643 repl = sctp_make_init(asoc, bp, GFP_ATOMIC, 0);
4644 if (!repl)
4645 return SCTP_DISPOSITION_NOMEM;
4646
4647 /* Choose transport for INIT. */
4648 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
4649 SCTP_CHUNK(repl));
4650
4651 /* Issue a sideeffect to do the needed accounting. */
4652 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_RESTART,
4653 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4654
4655 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
4656 } else {
4657 SCTP_DEBUG_PRINTK("Giving up on INIT, attempts: %d"
4658 " max_init_attempts: %d\n",
4659 attempts, asoc->max_init_attempts);
4660 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
4661 SCTP_U32(SCTP_ERROR_NO_ERROR));
4662 return SCTP_DISPOSITION_DELETE_TCB;
4663 }
4664
4665 return SCTP_DISPOSITION_CONSUME;
4666}
4667
4668/*
4669 * sctp_sf_t1_cookie_timer_expire
4670 *
4671 * Section: 4 Note: 2
4672 * Verification Tag:
4673 * Inputs
4674 * (endpoint, asoc)
4675 *
4676 * RFC 2960 Section 4 Notes
4677 * 3) If the T1-cookie timer expires, the endpoint MUST retransmit
1da177e4
LT		 4678 * COOKIE ECHO and re-start the T1-cookie timer without changing
4679 * state. This MUST be repeated up to 'Max.Init.Retransmits' times.
4680 * After that, the endpoint MUST abort the initialization process and
4681 * report the error to SCTP user.
4682 *
4683 * Outputs
4684 * (timers, events)
4685 *
4686 */
3f7a87d2 4687sctp_disposition_t sctp_sf_t1_cookie_timer_expire(const struct sctp_endpoint *ep,
1da177e4
LT		 4688 const struct sctp_association *asoc,
4689 const sctp_subtype_t type,
4690 void *arg,
4691 sctp_cmd_seq_t *commands)
4692{
3f7a87d2
FF		 4693 struct sctp_chunk *repl = NULL;
4694 int attempts = asoc->init_err_counter + 1;
1da177e4 4695
3f7a87d2 4696 SCTP_DEBUG_PRINTK("Timer T1 expired (COOKIE-ECHO).\n");
1da177e4
LT		 4697
4698 if (attempts < asoc->max_init_attempts) {
3f7a87d2 4699 repl = sctp_make_cookie_echo(asoc, NULL);
1da177e4 4700 if (!repl)
3f7a87d2 4701 return SCTP_DISPOSITION_NOMEM;
1da177e4
LT		 4702
4703 /* Issue a sideeffect to do the needed accounting. */
3f7a87d2
FF		 4704 sctp_add_cmd_sf(commands, SCTP_CMD_COOKIEECHO_RESTART,
4705 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
4706
1da177e4
LT		 4707 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
4708 } else {
4709 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
4710 SCTP_U32(SCTP_ERROR_NO_ERROR));
4711 return SCTP_DISPOSITION_DELETE_TCB;
4712 }
4713
4714 return SCTP_DISPOSITION_CONSUME;
1da177e4
LT		 4715}
4716
4717/* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN
4718 * with the updated last sequential TSN received from its peer.
4719 *
4720 * An endpoint should limit the number of retransmissions of the
4721 * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'.
4722 * If this threshold is exceeded the endpoint should destroy the TCB and
4723 * MUST report the peer endpoint unreachable to the upper layer (and
4724 * thus the association enters the CLOSED state). The reception of any
4725 * packet from its peer (i.e. as the peer sends all of its queued DATA
4726 * chunks) should clear the endpoint's retransmission count and restart
4727 * the T2-Shutdown timer, giving its peer ample opportunity to transmit
4728 * all of its queued DATA chunks that have not yet been sent.
4729 */
4730sctp_disposition_t sctp_sf_t2_timer_expire(const struct sctp_endpoint *ep,
4731 const struct sctp_association *asoc,
4732 const sctp_subtype_t type,
4733 void *arg,
4734 sctp_cmd_seq_t *commands)
4735{
4736 struct sctp_chunk *reply = NULL;
4737
4738 SCTP_DEBUG_PRINTK("Timer T2 expired.\n");
4739 if (asoc->overall_error_count >= asoc->max_retrans) {
4740 /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
4741 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4742 SCTP_U32(SCTP_ERROR_NO_ERROR));
4743 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4744 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
4745 return SCTP_DISPOSITION_DELETE_TCB;
4746 }
4747
4748 switch (asoc->state) {
4749 case SCTP_STATE_SHUTDOWN_SENT:
4750 reply = sctp_make_shutdown(asoc, NULL);
4751 break;
4752
4753 case SCTP_STATE_SHUTDOWN_ACK_SENT:
4754 reply = sctp_make_shutdown_ack(asoc, NULL);
4755 break;
4756
4757 default:
4758 BUG();
4759 break;
4760 };
4761
4762 if (!reply)
4763 goto nomem;
4764
4765 /* Do some failure management (Section 8.2). */
4766 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
4767 SCTP_TRANSPORT(asoc->shutdown_last_sent_to));
4768
4769 /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for
4770 * the T2-shutdown timer.
4771 */
4772 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
4773
4774 /* Restart the T2-shutdown timer. */
4775 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
4776 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4777 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
4778 return SCTP_DISPOSITION_CONSUME;
4779
4780nomem:
4781 return SCTP_DISPOSITION_NOMEM;
4782}
4783
4784/*
4785 * ADDIP Section 4.1 ASCONF CHunk Procedures
4786 * If the T4 RTO timer expires the endpoint should do B1 to B5
4787 */
4788sctp_disposition_t sctp_sf_t4_timer_expire(
4789 const struct sctp_endpoint *ep,
4790 const struct sctp_association *asoc,
4791 const sctp_subtype_t type,
4792 void *arg,
4793 sctp_cmd_seq_t *commands)
4794{
4795 struct sctp_chunk *chunk = asoc->addip_last_asconf;
4796 struct sctp_transport *transport = chunk->transport;
4797
4798 /* ADDIP 4.1 B1) Increment the error counters and perform path failure
4799 * detection on the appropriate destination address as defined in
4800 * RFC2960 [5] section 8.1 and 8.2.
4801 */
4802 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
4803
4804 /* Reconfig T4 timer and transport. */
4805 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
4806
4807 /* ADDIP 4.1 B2) Increment the association error counters and perform
4808 * endpoint failure detection on the association as defined in
4809 * RFC2960 [5] section 8.1 and 8.2.
4810 * association error counter is incremented in SCTP_CMD_STRIKE.
4811 */
4812 if (asoc->overall_error_count >= asoc->max_retrans) {
4813 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4814 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
4815 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4816 SCTP_U32(SCTP_ERROR_NO_ERROR));
4817 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4818 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
4819 return SCTP_DISPOSITION_ABORT;
4820 }
4821
4822 /* ADDIP 4.1 B3) Back-off the destination address RTO value to which
4823 * the ASCONF chunk was sent by doubling the RTO timer value.
4824 * This is done in SCTP_CMD_STRIKE.
4825 */
4826
4827 /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible
4828 * choose an alternate destination address (please refer to RFC2960
4829 * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this
4830 * chunk, it MUST be the same (including its serial number) as the last
4831 * ASCONF sent.
4832 */
4833 sctp_chunk_hold(asoc->addip_last_asconf);
4834 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4835 SCTP_CHUNK(asoc->addip_last_asconf));
4836
4837 /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different
4838 * destination is selected, then the RTO used will be that of the new
4839 * destination address.
4840 */
4841 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
4842 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
4843
4844 return SCTP_DISPOSITION_CONSUME;
4845}
4846
4847/* sctpimpguide-05 Section 2.12.2
4848 * The sender of the SHUTDOWN MAY also start an overall guard timer
4849 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
4850 * At the expiration of this timer the sender SHOULD abort the association
4851 * by sending an ABORT chunk.
4852 */
4853sctp_disposition_t sctp_sf_t5_timer_expire(const struct sctp_endpoint *ep,
4854 const struct sctp_association *asoc,
4855 const sctp_subtype_t type,
4856 void *arg,
4857 sctp_cmd_seq_t *commands)
4858{
4859 struct sctp_chunk *reply = NULL;
4860
4861 SCTP_DEBUG_PRINTK("Timer T5 expired.\n");
4862
4863 reply = sctp_make_abort(asoc, NULL, 0);
4864 if (!reply)
4865 goto nomem;
4866
4867 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
4868 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4869 SCTP_U32(SCTP_ERROR_NO_ERROR));
4870
4871 return SCTP_DISPOSITION_DELETE_TCB;
4872nomem:
4873 return SCTP_DISPOSITION_NOMEM;
4874}
4875
4876/* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires,
4877 * the association is automatically closed by starting the shutdown process.
4878 * The work that needs to be done is same as when SHUTDOWN is initiated by
4879 * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown().
4880 */
4881sctp_disposition_t sctp_sf_autoclose_timer_expire(
4882 const struct sctp_endpoint *ep,
4883 const struct sctp_association *asoc,
4884 const sctp_subtype_t type,
4885 void *arg,
4886 sctp_cmd_seq_t *commands)
4887{
4888 int disposition;
4889
4890 /* From 9.2 Shutdown of an Association
4891 * Upon receipt of the SHUTDOWN primitive from its upper
4892 * layer, the endpoint enters SHUTDOWN-PENDING state and
4893 * remains there until all outstanding data has been
4894 * acknowledged by its peer. The endpoint accepts no new data
4895 * from its upper layer, but retransmits data to the far end
4896 * if necessary to fill gaps.
4897 */
4898 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4899 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
4900
4901 /* sctpimpguide-05 Section 2.12.2
4902 * The sender of the SHUTDOWN MAY also start an overall guard timer
4903 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
4904 */
4905 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4906 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4907 disposition = SCTP_DISPOSITION_CONSUME;
4908 if (sctp_outq_is_empty(&asoc->outqueue)) {
4909 disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type,
4910 arg, commands);
4911 }
4912 return disposition;
4913}
4914
4915/*****************************************************************************
4916 * These are sa state functions which could apply to all types of events.
4917 ****************************************************************************/
4918
4919/*
4920 * This table entry is not implemented.
4921 *
4922 * Inputs
4923 * (endpoint, asoc, chunk)
4924 *
4925 * The return value is the disposition of the chunk.
4926 */
4927sctp_disposition_t sctp_sf_not_impl(const struct sctp_endpoint *ep,
4928 const struct sctp_association *asoc,
4929 const sctp_subtype_t type,
4930 void *arg,
4931 sctp_cmd_seq_t *commands)
4932{
4933 return SCTP_DISPOSITION_NOT_IMPL;
4934}
4935
4936/*
4937 * This table entry represents a bug.
4938 *
4939 * Inputs
4940 * (endpoint, asoc, chunk)
4941 *
4942 * The return value is the disposition of the chunk.
4943 */
4944sctp_disposition_t sctp_sf_bug(const struct sctp_endpoint *ep,
4945 const struct sctp_association *asoc,
4946 const sctp_subtype_t type,
4947 void *arg,
4948 sctp_cmd_seq_t *commands)
4949{
4950 return SCTP_DISPOSITION_BUG;
4951}
4952
4953/*
4954 * This table entry represents the firing of a timer in the wrong state.
4955 * Since timer deletion cannot be guaranteed a timer 'may' end up firing
4956 * when the association is in the wrong state. This event should
4957 * be ignored, so as to prevent any rearming of the timer.
4958 *
4959 * Inputs
4960 * (endpoint, asoc, chunk)
4961 *
4962 * The return value is the disposition of the chunk.
4963 */
4964sctp_disposition_t sctp_sf_timer_ignore(const struct sctp_endpoint *ep,
4965 const struct sctp_association *asoc,
4966 const sctp_subtype_t type,
4967 void *arg,
4968 sctp_cmd_seq_t *commands)
4969{
4970 SCTP_DEBUG_PRINTK("Timer %d ignored.\n", type.chunk);
4971 return SCTP_DISPOSITION_CONSUME;
4972}
4973
4974/********************************************************************
4975 * 2nd Level Abstractions
4976 ********************************************************************/
4977
4978/* Pull the SACK chunk based on the SACK header. */
4979static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk)
4980{
4981 struct sctp_sackhdr *sack;
4982 unsigned int len;
4983 __u16 num_blocks;
4984 __u16 num_dup_tsns;
4985
4986 /* Protect ourselves from reading too far into
4987 * the skb from a bogus sender.
4988 */
4989 sack = (struct sctp_sackhdr *) chunk->skb->data;
4990
4991 num_blocks = ntohs(sack->num_gap_ack_blocks);
4992 num_dup_tsns = ntohs(sack->num_dup_tsns);
4993 len = sizeof(struct sctp_sackhdr);
4994 len += (num_blocks + num_dup_tsns) * sizeof(__u32);
4995 if (len > chunk->skb->len)
4996 return NULL;
4997
4998 skb_pull(chunk->skb, len);
4999
5000 return sack;
5001}
5002
5003/* Create an ABORT packet to be sent as a response, with the specified
5004 * error causes.
5005 */
5006static struct sctp_packet *sctp_abort_pkt_new(const struct sctp_endpoint *ep,
5007 const struct sctp_association *asoc,
5008 struct sctp_chunk *chunk,
5009 const void *payload,
5010 size_t paylen)
5011{
5012 struct sctp_packet *packet;
5013 struct sctp_chunk *abort;
5014
5015 packet = sctp_ootb_pkt_new(asoc, chunk);
5016
5017 if (packet) {
5018 /* Make an ABORT.
5019 * The T bit will be set if the asoc is NULL.
5020 */
5021 abort = sctp_make_abort(asoc, chunk, paylen);
5022 if (!abort) {
5023 sctp_ootb_pkt_free(packet);
5024 return NULL;
5025 }
047a2428
JF		 5026
5027 /* Reflect vtag if T-Bit is set */
5028 if (sctp_test_T_bit(abort))
5029 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
5030
1da177e4
LT		 5031 /* Add specified error causes, i.e., payload, to the
5032 * end of the chunk.
5033 */
5034 sctp_addto_chunk(abort, paylen, payload);
5035
5036 /* Set the skb to the belonging sock for accounting. */
5037 abort->skb->sk = ep->base.sk;
5038
5039 sctp_packet_append_chunk(packet, abort);
5040
5041 }
5042
5043 return packet;
5044}
5045
5046/* Allocate a packet for responding in the OOTB conditions. */
5047static struct sctp_packet *sctp_ootb_pkt_new(const struct sctp_association *asoc,
5048 const struct sctp_chunk *chunk)
5049{
5050 struct sctp_packet *packet;
5051 struct sctp_transport *transport;
5052 __u16 sport;
5053 __u16 dport;
5054 __u32 vtag;
5055
5056 /* Get the source and destination port from the inbound packet. */
5057 sport = ntohs(chunk->sctp_hdr->dest);
5058 dport = ntohs(chunk->sctp_hdr->source);
5059
5060 /* The V-tag is going to be the same as the inbound packet if no
5061 * association exists, otherwise, use the peer's vtag.
5062 */
5063 if (asoc) {
5064 vtag = asoc->peer.i.init_tag;
5065 } else {
5066 /* Special case the INIT and stale COOKIE_ECHO as there is no
5067 * vtag yet.
5068 */
5069 switch(chunk->chunk_hdr->type) {
5070 case SCTP_CID_INIT:
5071 {
5072 sctp_init_chunk_t *init;
5073
5074 init = (sctp_init_chunk_t *)chunk->chunk_hdr;
5075 vtag = ntohl(init->init_hdr.init_tag);
5076 break;
5077 }
5078 default:
5079 vtag = ntohl(chunk->sctp_hdr->vtag);
5080 break;
5081 }
5082 }
5083
5084 /* Make a transport for the bucket, Eliza... */
5085 transport = sctp_transport_new(sctp_source(chunk), GFP_ATOMIC);
5086 if (!transport)
5087 goto nomem;
5088
5089 /* Cache a route for the transport with the chunk's destination as
5090 * the source address.
5091 */
5092 sctp_transport_route(transport, (union sctp_addr *)&chunk->dest,
5093 sctp_sk(sctp_get_ctl_sock()));
5094
5095 packet = sctp_packet_init(&transport->packet, transport, sport, dport);
5096 packet = sctp_packet_config(packet, vtag, 0);
5097
5098 return packet;
5099
5100nomem:
5101 return NULL;
5102}
5103
5104/* Free the packet allocated earlier for responding in the OOTB condition. */
5105void sctp_ootb_pkt_free(struct sctp_packet *packet)
5106{
5107 sctp_transport_free(packet->transport);
5108}
5109
5110/* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */
5111static void sctp_send_stale_cookie_err(const struct sctp_endpoint *ep,
5112 const struct sctp_association *asoc,
5113 const struct sctp_chunk *chunk,
5114 sctp_cmd_seq_t *commands,
5115 struct sctp_chunk *err_chunk)
5116{
5117 struct sctp_packet *packet;
5118
5119 if (err_chunk) {
5120 packet = sctp_ootb_pkt_new(asoc, chunk);
5121 if (packet) {
5122 struct sctp_signed_cookie *cookie;
5123
5124 /* Override the OOTB vtag from the cookie. */
5125 cookie = chunk->subh.cookie_hdr;
5126 packet->vtag = cookie->c.peer_vtag;
5127
5128 /* Set the skb to the belonging sock for accounting. */
5129 err_chunk->skb->sk = ep->base.sk;
5130 sctp_packet_append_chunk(packet, err_chunk);
5131 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
5132 SCTP_PACKET(packet));
5133 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
5134 } else
5135 sctp_chunk_free (err_chunk);
5136 }
5137}
5138
5139
5140/* Process a data chunk */
5141static int sctp_eat_data(const struct sctp_association *asoc,
5142 struct sctp_chunk *chunk,
5143 sctp_cmd_seq_t *commands)
5144{
5145 sctp_datahdr_t *data_hdr;
5146 struct sctp_chunk *err;
5147 size_t datalen;
5148 sctp_verb_t deliver;
5149 int tmp;
5150 __u32 tsn;
5151
5152 data_hdr = chunk->subh.data_hdr = (sctp_datahdr_t *)chunk->skb->data;
5153 skb_pull(chunk->skb, sizeof(sctp_datahdr_t));
5154
5155 tsn = ntohl(data_hdr->tsn);
5156 SCTP_DEBUG_PRINTK("eat_data: TSN 0x%x.\n", tsn);
5157
5158 /* ASSERT: Now skb->data is really the user data. */
5159
5160 /* Process ECN based congestion.
5161 *
5162 * Since the chunk structure is reused for all chunks within
5163 * a packet, we use ecn_ce_done to track if we've already
5164 * done CE processing for this packet.
5165 *
5166 * We need to do ECN processing even if we plan to discard the
5167 * chunk later.
5168 */
5169
5170 if (!chunk->ecn_ce_done) {
5171 struct sctp_af *af;
5172 chunk->ecn_ce_done = 1;
5173
5174 af = sctp_get_af_specific(
5175 ipver2af(chunk->skb->nh.iph->version));
5176
5177 if (af && af->is_ce(chunk->skb) && asoc->peer.ecn_capable) {
5178 /* Do real work as sideffect. */
5179 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_CE,
5180 SCTP_U32(tsn));
5181 }
5182 }
5183
5184 tmp = sctp_tsnmap_check(&asoc->peer.tsn_map, tsn);
5185 if (tmp < 0) {
5186 /* The TSN is too high--silently discard the chunk and
5187 * count on it getting retransmitted later.
5188 */
5189 return SCTP_IERROR_HIGH_TSN;
5190 } else if (tmp > 0) {
5191 /* This is a duplicate. Record it. */
5192 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_DUP, SCTP_U32(tsn));
5193 return SCTP_IERROR_DUP_TSN;
5194 }
5195
5196 /* This is a new TSN. */
5197
5198 /* Discard if there is no room in the receive window.
5199 * Actually, allow a little bit of overflow (up to a MTU).
5200 */
5201 datalen = ntohs(chunk->chunk_hdr->length);
5202 datalen -= sizeof(sctp_data_chunk_t);
5203
5204 deliver = SCTP_CMD_CHUNK_ULP;
5205
5206 /* Think about partial delivery. */
5207 if ((datalen >= asoc->rwnd) && (!asoc->ulpq.pd_mode)) {
5208
5209 /* Even if we don't accept this chunk there is
5210 * memory pressure.
5211 */
5212 sctp_add_cmd_sf(commands, SCTP_CMD_PART_DELIVER, SCTP_NULL());
5213 }
5214
5215 /* Spill over rwnd a little bit. Note: While allowed, this spill over
5216 * seems a bit troublesome in that frag_point varies based on
5217 * PMTU. In cases, such as loopback, this might be a rather
5218 * large spill over.
5219 */
5220 if (!asoc->rwnd || asoc->rwnd_over ||
5221 (datalen > asoc->rwnd + asoc->frag_point)) {
5222
5223 /* If this is the next TSN, consider reneging to make
5224 * room. Note: Playing nice with a confused sender. A
5225 * malicious sender can still eat up all our buffer
5226 * space and in the future we may want to detect and
5227 * do more drastic reneging.
5228 */
5229 if (sctp_tsnmap_has_gap(&asoc->peer.tsn_map) &&
5230 (sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map) + 1) == tsn) {
5231 SCTP_DEBUG_PRINTK("Reneging for tsn:%u\n", tsn);
5232 deliver = SCTP_CMD_RENEGE;
5233 } else {
5234 SCTP_DEBUG_PRINTK("Discard tsn: %u len: %Zd, "
5235 "rwnd: %d\n", tsn, datalen,
5236 asoc->rwnd);
5237 return SCTP_IERROR_IGNORE_TSN;
5238 }
5239 }
5240
5241 /*
5242 * Section 3.3.10.9 No User Data (9)
5243 *
5244 * Cause of error
5245 * ---------------
5246 * No User Data: This error cause is returned to the originator of a
5247 * DATA chunk if a received DATA chunk has no user data.
5248 */
5249 if (unlikely(0 == datalen)) {
5250 err = sctp_make_abort_no_data(asoc, chunk, tsn);
5251 if (err) {
5252 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
5253 SCTP_CHUNK(err));
5254 }
5255 /* We are going to ABORT, so we might as well stop
5256 * processing the rest of the chunks in the packet.
5257 */
5258 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
5259 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5260 SCTP_U32(SCTP_ERROR_NO_DATA));
5261 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
5262 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
5263 return SCTP_IERROR_NO_DATA;
5264 }
5265
5266 /* If definately accepting the DATA chunk, record its TSN, otherwise
5267 * wait for renege processing.
5268 */
5269 if (SCTP_CMD_CHUNK_ULP == deliver)
5270 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_TSN, SCTP_U32(tsn));
5271
5272 /* Note: Some chunks may get overcounted (if we drop) or overcounted
5273 * if we renege and the chunk arrives again.
5274 */
5275 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
5276 SCTP_INC_STATS(SCTP_MIB_INUNORDERCHUNKS);
5277 else
5278 SCTP_INC_STATS(SCTP_MIB_INORDERCHUNKS);
5279
5280 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
5281 *
5282 * If an endpoint receive a DATA chunk with an invalid stream
5283 * identifier, it shall acknowledge the reception of the DATA chunk
5284 * following the normal procedure, immediately send an ERROR chunk
5285 * with cause set to "Invalid Stream Identifier" (See Section 3.3.10)
5286 * and discard the DATA chunk.
5287 */
5288 if (ntohs(data_hdr->stream) >= asoc->c.sinit_max_instreams) {
5289 err = sctp_make_op_error(asoc, chunk, SCTP_ERROR_INV_STRM,
5290 &data_hdr->stream,
5291 sizeof(data_hdr->stream));
5292 if (err)
5293 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
5294 SCTP_CHUNK(err));
5295 return SCTP_IERROR_BAD_STREAM;
5296 }
5297
5298 /* Send the data up to the user. Note: Schedule the
5299 * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK
5300 * chunk needs the updated rwnd.
5301 */
5302 sctp_add_cmd_sf(commands, deliver, SCTP_CHUNK(chunk));
5303
5304 return SCTP_IERROR_NO_ERROR;
5305}
kernel source for telekom puls (alcatel/mediatek)