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60c778b2 1/* SCTP kernel implementation
1da177e4
LT
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 *
60c778b2 8 * This is part of the SCTP Linux Kernel Implementation.
1da177e4
LT
9 *
10 * These are the state functions for the state machine.
11 *
60c778b2 12 * This SCTP implementation is free software;
1da177e4
LT
13 * you can redistribute it and/or modify it under the terms of
14 * the GNU General Public License as published by
15 * the Free Software Foundation; either version 2, or (at your option)
16 * any later version.
17 *
60c778b2 18 * This SCTP implementation is distributed in the hope that it
1da177e4
LT
19 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
20 * ************************
21 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
22 * See the GNU General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License
25 * along with GNU CC; see the file COPYING. If not, write to
26 * the Free Software Foundation, 59 Temple Place - Suite 330,
27 * Boston, MA 02111-1307, USA.
28 *
29 * Please send any bug reports or fixes you make to the
30 * email address(es):
31 * lksctp developers <lksctp-developers@lists.sourceforge.net>
32 *
33 * Or submit a bug report through the following website:
34 * http://www.sf.net/projects/lksctp
35 *
36 * Written or modified by:
37 * La Monte H.P. Yarroll <piggy@acm.org>
38 * Karl Knutson <karl@athena.chicago.il.us>
39 * Mathew Kotowsky <kotowsky@sctp.org>
40 * Sridhar Samudrala <samudrala@us.ibm.com>
41 * Jon Grimm <jgrimm@us.ibm.com>
42 * Hui Huang <hui.huang@nokia.com>
43 * Dajiang Zhang <dajiang.zhang@nokia.com>
44 * Daisy Chang <daisyc@us.ibm.com>
45 * Ardelle Fan <ardelle.fan@intel.com>
46 * Ryan Layer <rmlayer@us.ibm.com>
47 * Kevin Gao <kevin.gao@intel.com>
48 *
49 * Any bugs reported given to us we will try to fix... any fixes shared will
50 * be incorporated into the next SCTP release.
51 */
52
145ce502
JP
53#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
54
1da177e4
LT
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>
5a0e3ad6 61#include <linux/slab.h>
1da177e4
LT
62#include <net/sock.h>
63#include <net/inet_ecn.h>
64#include <linux/skbuff.h>
65#include <net/sctp/sctp.h>
66#include <net/sctp/sm.h>
67#include <net/sctp/structs.h>
68
69static struct sctp_packet *sctp_abort_pkt_new(const struct sctp_endpoint *ep,
70 const struct sctp_association *asoc,
71 struct sctp_chunk *chunk,
72 const void *payload,
73 size_t paylen);
74static int sctp_eat_data(const struct sctp_association *asoc,
75 struct sctp_chunk *chunk,
76 sctp_cmd_seq_t *commands);
2ce95503
EB
77static struct sctp_packet *sctp_ootb_pkt_new(struct net *net,
78 const struct sctp_association *asoc,
1da177e4
LT
79 const struct sctp_chunk *chunk);
80static void sctp_send_stale_cookie_err(const struct sctp_endpoint *ep,
81 const struct sctp_association *asoc,
82 const struct sctp_chunk *chunk,
83 sctp_cmd_seq_t *commands,
84 struct sctp_chunk *err_chunk);
85static sctp_disposition_t sctp_sf_do_5_2_6_stale(const struct sctp_endpoint *ep,
86 const struct sctp_association *asoc,
87 const sctp_subtype_t type,
88 void *arg,
89 sctp_cmd_seq_t *commands);
90static sctp_disposition_t sctp_sf_shut_8_4_5(const struct sctp_endpoint *ep,
91 const struct sctp_association *asoc,
92 const sctp_subtype_t type,
93 void *arg,
94 sctp_cmd_seq_t *commands);
ece25dfa
VY
95static sctp_disposition_t sctp_sf_tabort_8_4_8(const struct sctp_endpoint *ep,
96 const struct sctp_association *asoc,
97 const sctp_subtype_t type,
98 void *arg,
99 sctp_cmd_seq_t *commands);
1da177e4
LT
100static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk);
101
52c1da39 102static sctp_disposition_t sctp_stop_t1_and_abort(sctp_cmd_seq_t *commands,
f94c0198 103 __be16 error, int sk_err,
52c1da39
AB
104 const struct sctp_association *asoc,
105 struct sctp_transport *transport);
106
aecedeab 107static sctp_disposition_t sctp_sf_abort_violation(
ece25dfa 108 const struct sctp_endpoint *ep,
aecedeab
WY
109 const struct sctp_association *asoc,
110 void *arg,
111 sctp_cmd_seq_t *commands,
112 const __u8 *payload,
113 const size_t paylen);
114
52c1da39
AB
115static sctp_disposition_t sctp_sf_violation_chunklen(
116 const struct sctp_endpoint *ep,
117 const struct sctp_association *asoc,
118 const sctp_subtype_t type,
119 void *arg,
120 sctp_cmd_seq_t *commands);
1da177e4 121
6f4c618d
WY
122static sctp_disposition_t sctp_sf_violation_paramlen(
123 const struct sctp_endpoint *ep,
124 const struct sctp_association *asoc,
125 const sctp_subtype_t type,
ba016670 126 void *arg, void *ext,
6f4c618d
WY
127 sctp_cmd_seq_t *commands);
128
aecedeab
WY
129static sctp_disposition_t sctp_sf_violation_ctsn(
130 const struct sctp_endpoint *ep,
131 const struct sctp_association *asoc,
132 const sctp_subtype_t type,
133 void *arg,
134 sctp_cmd_seq_t *commands);
135
ece25dfa
VY
136static sctp_disposition_t sctp_sf_violation_chunk(
137 const struct sctp_endpoint *ep,
138 const struct sctp_association *asoc,
139 const sctp_subtype_t type,
140 void *arg,
141 sctp_cmd_seq_t *commands);
142
bbd0d598
VY
143static sctp_ierror_t sctp_sf_authenticate(const struct sctp_endpoint *ep,
144 const struct sctp_association *asoc,
145 const sctp_subtype_t type,
146 struct sctp_chunk *chunk);
147
75205f47
VY
148static sctp_disposition_t __sctp_sf_do_9_1_abort(const struct sctp_endpoint *ep,
149 const struct sctp_association *asoc,
150 const sctp_subtype_t type,
151 void *arg,
152 sctp_cmd_seq_t *commands);
153
1da177e4
LT
154/* Small helper function that checks if the chunk length
155 * is of the appropriate length. The 'required_length' argument
156 * is set to be the size of a specific chunk we are testing.
157 * Return Values: 1 = Valid length
158 * 0 = Invalid length
159 *
160 */
161static inline int
162sctp_chunk_length_valid(struct sctp_chunk *chunk,
163 __u16 required_length)
164{
165 __u16 chunk_length = ntohs(chunk->chunk_hdr->length);
166
167 if (unlikely(chunk_length < required_length))
168 return 0;
169
170 return 1;
171}
172
173/**********************************************************
174 * These are the state functions for handling chunk events.
175 **********************************************************/
176
177/*
178 * Process the final SHUTDOWN COMPLETE.
179 *
180 * Section: 4 (C) (diagram), 9.2
181 * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify
182 * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be
183 * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint
184 * should stop the T2-shutdown timer and remove all knowledge of the
185 * association (and thus the association enters the CLOSED state).
186 *
047a2428 187 * Verification Tag: 8.5.1(C), sctpimpguide 2.41.
1da177e4
LT
188 * C) Rules for packet carrying SHUTDOWN COMPLETE:
189 * ...
047a2428
JF
190 * - The receiver of a SHUTDOWN COMPLETE shall accept the packet
191 * if the Verification Tag field of the packet matches its own tag and
192 * the T bit is not set
193 * OR
194 * it is set to its peer's tag and the T bit is set in the Chunk
195 * Flags.
196 * Otherwise, the receiver MUST silently discard the packet
197 * and take no further action. An endpoint MUST ignore the
198 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
1da177e4
LT
199 *
200 * Inputs
201 * (endpoint, asoc, chunk)
202 *
203 * Outputs
204 * (asoc, reply_msg, msg_up, timers, counters)
205 *
206 * The return value is the disposition of the chunk.
207 */
208sctp_disposition_t sctp_sf_do_4_C(const struct sctp_endpoint *ep,
209 const struct sctp_association *asoc,
210 const sctp_subtype_t type,
211 void *arg,
212 sctp_cmd_seq_t *commands)
213{
214 struct sctp_chunk *chunk = arg;
215 struct sctp_ulpevent *ev;
b01a2407 216 struct net *net;
1da177e4 217
ece25dfa
VY
218 if (!sctp_vtag_verify_either(chunk, asoc))
219 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
220
1da177e4
LT
221 /* RFC 2960 6.10 Bundling
222 *
223 * An endpoint MUST NOT bundle INIT, INIT ACK or
224 * SHUTDOWN COMPLETE with any other chunks.
225 */
226 if (!chunk->singleton)
ece25dfa 227 return sctp_sf_violation_chunk(ep, asoc, type, arg, commands);
1da177e4 228
ece25dfa
VY
229 /* Make sure that the SHUTDOWN_COMPLETE chunk has a valid length. */
230 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
231 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
232 commands);
1da177e4
LT
233
234 /* RFC 2960 10.2 SCTP-to-ULP
235 *
236 * H) SHUTDOWN COMPLETE notification
237 *
238 * When SCTP completes the shutdown procedures (section 9.2) this
239 * notification is passed to the upper layer.
240 */
241 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
a5a35e76 242 0, 0, 0, NULL, GFP_ATOMIC);
df7deeb5
VY
243 if (ev)
244 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
d808ad9a 245 SCTP_ULPEVENT(ev));
1da177e4
LT
246
247 /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint
248 * will verify that it is in SHUTDOWN-ACK-SENT state, if it is
249 * not the chunk should be discarded. If the endpoint is in
250 * the SHUTDOWN-ACK-SENT state the endpoint should stop the
251 * T2-shutdown timer and remove all knowledge of the
252 * association (and thus the association enters the CLOSED
253 * state).
254 */
255 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
256 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
257
258 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
259 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
260
261 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
262 SCTP_STATE(SCTP_STATE_CLOSED));
263
b01a2407
EB
264 net = sock_net(asoc->base.sk);
265 SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS);
266 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
1da177e4
LT
267
268 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
269
270 return SCTP_DISPOSITION_DELETE_TCB;
1da177e4
LT
271}
272
273/*
274 * Respond to a normal INIT chunk.
275 * We are the side that is being asked for an association.
276 *
277 * Section: 5.1 Normal Establishment of an Association, B
278 * B) "Z" shall respond immediately with an INIT ACK chunk. The
279 * destination IP address of the INIT ACK MUST be set to the source
280 * IP address of the INIT to which this INIT ACK is responding. In
281 * the response, besides filling in other parameters, "Z" must set the
282 * Verification Tag field to Tag_A, and also provide its own
283 * Verification Tag (Tag_Z) in the Initiate Tag field.
284 *
d808ad9a 285 * Verification Tag: Must be 0.
1da177e4
LT
286 *
287 * Inputs
288 * (endpoint, asoc, chunk)
289 *
290 * Outputs
291 * (asoc, reply_msg, msg_up, timers, counters)
292 *
293 * The return value is the disposition of the chunk.
294 */
295sctp_disposition_t sctp_sf_do_5_1B_init(const struct sctp_endpoint *ep,
296 const struct sctp_association *asoc,
297 const sctp_subtype_t type,
298 void *arg,
299 sctp_cmd_seq_t *commands)
300{
301 struct sctp_chunk *chunk = arg;
302 struct sctp_chunk *repl;
303 struct sctp_association *new_asoc;
304 struct sctp_chunk *err_chunk;
305 struct sctp_packet *packet;
306 sctp_unrecognized_param_t *unk_param;
2ce95503 307 struct net *net;
1da177e4
LT
308 int len;
309
310 /* 6.10 Bundling
311 * An endpoint MUST NOT bundle INIT, INIT ACK or
312 * SHUTDOWN COMPLETE with any other chunks.
d808ad9a 313 *
1da177e4
LT
314 * IG Section 2.11.2
315 * Furthermore, we require that the receiver of an INIT chunk MUST
316 * enforce these rules by silently discarding an arriving packet
317 * with an INIT chunk that is bundled with other chunks.
318 */
319 if (!chunk->singleton)
320 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
321
322 /* If the packet is an OOTB packet which is temporarily on the
323 * control endpoint, respond with an ABORT.
324 */
2ce95503
EB
325 net = sock_net(ep->base.sk);
326 if (ep == sctp_sk(net->sctp.ctl_sock)->ep) {
b01a2407 327 SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
1da177e4 328 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
8190f89d 329 }
1da177e4 330
1da177e4 331 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
d808ad9a 332 * Tag.
1da177e4
LT
333 */
334 if (chunk->sctp_hdr->vtag != 0)
335 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
336
337 /* Make sure that the INIT chunk has a valid length.
338 * Normally, this would cause an ABORT with a Protocol Violation
339 * error, but since we don't have an association, we'll
340 * just discard the packet.
341 */
342 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
343 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
344
bec9640b
VY
345 /* If the INIT is coming toward a closing socket, we'll send back
346 * and ABORT. Essentially, this catches the race of INIT being
347 * backloged to the socket at the same time as the user isses close().
348 * Since the socket and all its associations are going away, we
349 * can treat this OOTB
350 */
351 if (sctp_sstate(ep->base.sk, CLOSING))
352 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
353
1da177e4
LT
354 /* Verify the INIT chunk before processing it. */
355 err_chunk = NULL;
356 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
357 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
358 &err_chunk)) {
359 /* This chunk contains fatal error. It is to be discarded.
360 * Send an ABORT, with causes if there is any.
361 */
362 if (err_chunk) {
363 packet = sctp_abort_pkt_new(ep, asoc, arg,
364 (__u8 *)(err_chunk->chunk_hdr) +
365 sizeof(sctp_chunkhdr_t),
366 ntohs(err_chunk->chunk_hdr->length) -
367 sizeof(sctp_chunkhdr_t));
368
369 sctp_chunk_free(err_chunk);
370
371 if (packet) {
372 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
373 SCTP_PACKET(packet));
b01a2407 374 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
1da177e4
LT
375 return SCTP_DISPOSITION_CONSUME;
376 } else {
377 return SCTP_DISPOSITION_NOMEM;
378 }
379 } else {
380 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg,
381 commands);
382 }
383 }
384
d808ad9a 385 /* Grab the INIT header. */
1da177e4
LT
386 chunk->subh.init_hdr = (sctp_inithdr_t *)chunk->skb->data;
387
388 /* Tag the variable length parameters. */
389 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
390
391 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
392 if (!new_asoc)
393 goto nomem;
394
409b95af
VY
395 if (sctp_assoc_set_bind_addr_from_ep(new_asoc,
396 sctp_scope(sctp_source(chunk)),
397 GFP_ATOMIC) < 0)
398 goto nomem_init;
399
1da177e4 400 /* The call, sctp_process_init(), can fail on memory allocation. */
de6becdc 401 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk),
1da177e4
LT
402 (sctp_init_chunk_t *)chunk->chunk_hdr,
403 GFP_ATOMIC))
404 goto nomem_init;
405
1da177e4
LT
406 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
407
408 /* If there are errors need to be reported for unknown parameters,
409 * make sure to reserve enough room in the INIT ACK for them.
410 */
411 len = 0;
412 if (err_chunk)
413 len = ntohs(err_chunk->chunk_hdr->length) -
414 sizeof(sctp_chunkhdr_t);
415
1da177e4
LT
416 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
417 if (!repl)
df7deeb5 418 goto nomem_init;
1da177e4
LT
419
420 /* If there are errors need to be reported for unknown parameters,
421 * include them in the outgoing INIT ACK as "Unrecognized parameter"
422 * parameter.
423 */
424 if (err_chunk) {
425 /* Get the "Unrecognized parameter" parameter(s) out of the
426 * ERROR chunk generated by sctp_verify_init(). Since the
427 * error cause code for "unknown parameter" and the
428 * "Unrecognized parameter" type is the same, we can
429 * construct the parameters in INIT ACK by copying the
430 * ERROR causes over.
431 */
432 unk_param = (sctp_unrecognized_param_t *)
433 ((__u8 *)(err_chunk->chunk_hdr) +
434 sizeof(sctp_chunkhdr_t));
435 /* Replace the cause code with the "Unrecognized parameter"
436 * parameter type.
437 */
438 sctp_addto_chunk(repl, len, unk_param);
439 sctp_chunk_free(err_chunk);
440 }
441
df7deeb5
VY
442 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
443
1da177e4
LT
444 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
445
446 /*
447 * Note: After sending out INIT ACK with the State Cookie parameter,
448 * "Z" MUST NOT allocate any resources, nor keep any states for the
449 * new association. Otherwise, "Z" will be vulnerable to resource
450 * attacks.
451 */
452 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
453
454 return SCTP_DISPOSITION_DELETE_TCB;
455
1da177e4
LT
456nomem_init:
457 sctp_association_free(new_asoc);
458nomem:
df7deeb5
VY
459 if (err_chunk)
460 sctp_chunk_free(err_chunk);
1da177e4
LT
461 return SCTP_DISPOSITION_NOMEM;
462}
463
464/*
465 * Respond to a normal INIT ACK chunk.
466 * We are the side that is initiating the association.
467 *
468 * Section: 5.1 Normal Establishment of an Association, C
469 * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init
470 * timer and leave COOKIE-WAIT state. "A" shall then send the State
471 * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start
472 * the T1-cookie timer, and enter the COOKIE-ECHOED state.
473 *
474 * Note: The COOKIE ECHO chunk can be bundled with any pending outbound
475 * DATA chunks, but it MUST be the first chunk in the packet and
476 * until the COOKIE ACK is returned the sender MUST NOT send any
477 * other packets to the peer.
478 *
479 * Verification Tag: 3.3.3
480 * If the value of the Initiate Tag in a received INIT ACK chunk is
481 * found to be 0, the receiver MUST treat it as an error and close the
482 * association by transmitting an ABORT.
483 *
484 * Inputs
485 * (endpoint, asoc, chunk)
486 *
487 * Outputs
488 * (asoc, reply_msg, msg_up, timers, counters)
489 *
490 * The return value is the disposition of the chunk.
491 */
492sctp_disposition_t sctp_sf_do_5_1C_ack(const struct sctp_endpoint *ep,
493 const struct sctp_association *asoc,
494 const sctp_subtype_t type,
495 void *arg,
496 sctp_cmd_seq_t *commands)
497{
498 struct sctp_chunk *chunk = arg;
499 sctp_init_chunk_t *initchunk;
1da177e4
LT
500 struct sctp_chunk *err_chunk;
501 struct sctp_packet *packet;
1da177e4
LT
502
503 if (!sctp_vtag_verify(chunk, asoc))
504 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
505
1da177e4
LT
506 /* 6.10 Bundling
507 * An endpoint MUST NOT bundle INIT, INIT ACK or
508 * SHUTDOWN COMPLETE with any other chunks.
509 */
510 if (!chunk->singleton)
ece25dfa 511 return sctp_sf_violation_chunk(ep, asoc, type, arg, commands);
1da177e4 512
ece25dfa
VY
513 /* Make sure that the INIT-ACK chunk has a valid length */
514 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_initack_chunk_t)))
515 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
516 commands);
1da177e4
LT
517 /* Grab the INIT header. */
518 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
519
1da177e4
LT
520 /* Verify the INIT chunk before processing it. */
521 err_chunk = NULL;
522 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
523 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
524 &err_chunk)) {
525
853f4b50
VY
526 sctp_error_t error = SCTP_ERROR_NO_RESOURCE;
527
1da177e4 528 /* This chunk contains fatal error. It is to be discarded.
d6701191
VY
529 * Send an ABORT, with causes. If there are no causes,
530 * then there wasn't enough memory. Just terminate
531 * the association.
1da177e4
LT
532 */
533 if (err_chunk) {
534 packet = sctp_abort_pkt_new(ep, asoc, arg,
535 (__u8 *)(err_chunk->chunk_hdr) +
536 sizeof(sctp_chunkhdr_t),
537 ntohs(err_chunk->chunk_hdr->length) -
538 sizeof(sctp_chunkhdr_t));
539
540 sctp_chunk_free(err_chunk);
541
542 if (packet) {
543 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
544 SCTP_PACKET(packet));
b01a2407 545 SCTP_INC_STATS(sock_net(ep->base.sk), SCTP_MIB_OUTCTRLCHUNKS);
8de8c873 546 error = SCTP_ERROR_INV_PARAM;
1da177e4 547 }
1da177e4 548 }
bbd0d598
VY
549
550 /* SCTP-AUTH, Section 6.3:
551 * It should be noted that if the receiver wants to tear
552 * down an association in an authenticated way only, the
553 * handling of malformed packets should not result in
554 * tearing down the association.
555 *
556 * This means that if we only want to abort associations
557 * in an authenticated way (i.e AUTH+ABORT), then we
25985edc 558 * can't destroy this association just because the packet
bbd0d598
VY
559 * was malformed.
560 */
561 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
562 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
563
b01a2407 564 SCTP_INC_STATS(sock_net(ep->base.sk), SCTP_MIB_ABORTEDS);
8de8c873
SS
565 return sctp_stop_t1_and_abort(commands, error, ECONNREFUSED,
566 asoc, chunk->transport);
1da177e4
LT
567 }
568
569 /* Tag the variable length parameters. Note that we never
570 * convert the parameters in an INIT chunk.
571 */
572 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
573
574 initchunk = (sctp_init_chunk_t *) chunk->chunk_hdr;
575
576 sctp_add_cmd_sf(commands, SCTP_CMD_PEER_INIT,
577 SCTP_PEER_INIT(initchunk));
578
3f7a87d2
FF
579 /* Reset init error count upon receipt of INIT-ACK. */
580 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
581
1da177e4
LT
582 /* 5.1 C) "A" shall stop the T1-init timer and leave
583 * COOKIE-WAIT state. "A" shall then ... start the T1-cookie
584 * timer, and enter the COOKIE-ECHOED state.
585 */
586 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
587 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
588 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
589 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
590 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
591 SCTP_STATE(SCTP_STATE_COOKIE_ECHOED));
592
730fc3d0
VY
593 /* SCTP-AUTH: genereate the assocition shared keys so that
594 * we can potentially signe the COOKIE-ECHO.
595 */
596 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_SHKEY, SCTP_NULL());
597
1da177e4
LT
598 /* 5.1 C) "A" shall then send the State Cookie received in the
599 * INIT ACK chunk in a COOKIE ECHO chunk, ...
600 */
601 /* If there is any errors to report, send the ERROR chunk generated
602 * for unknown parameters as well.
603 */
604 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_COOKIE_ECHO,
605 SCTP_CHUNK(err_chunk));
606
607 return SCTP_DISPOSITION_CONSUME;
1da177e4
LT
608}
609
610/*
611 * Respond to a normal COOKIE ECHO chunk.
612 * We are the side that is being asked for an association.
613 *
614 * Section: 5.1 Normal Establishment of an Association, D
615 * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply
616 * with a COOKIE ACK chunk after building a TCB and moving to
617 * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with
618 * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK
619 * chunk MUST be the first chunk in the packet.
620 *
621 * IMPLEMENTATION NOTE: An implementation may choose to send the
622 * Communication Up notification to the SCTP user upon reception
623 * of a valid COOKIE ECHO chunk.
624 *
625 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
626 * D) Rules for packet carrying a COOKIE ECHO
627 *
628 * - When sending a COOKIE ECHO, the endpoint MUST use the value of the
629 * Initial Tag received in the INIT ACK.
630 *
631 * - The receiver of a COOKIE ECHO follows the procedures in Section 5.
632 *
633 * Inputs
634 * (endpoint, asoc, chunk)
635 *
636 * Outputs
637 * (asoc, reply_msg, msg_up, timers, counters)
638 *
639 * The return value is the disposition of the chunk.
640 */
641sctp_disposition_t sctp_sf_do_5_1D_ce(const struct sctp_endpoint *ep,
642 const struct sctp_association *asoc,
643 const sctp_subtype_t type, void *arg,
644 sctp_cmd_seq_t *commands)
645{
646 struct sctp_chunk *chunk = arg;
647 struct sctp_association *new_asoc;
648 sctp_init_chunk_t *peer_init;
649 struct sctp_chunk *repl;
df7deeb5 650 struct sctp_ulpevent *ev, *ai_ev = NULL;
1da177e4
LT
651 int error = 0;
652 struct sctp_chunk *err_chk_p;
609ee467 653 struct sock *sk;
2ce95503 654 struct net *net;
1da177e4
LT
655
656 /* If the packet is an OOTB packet which is temporarily on the
657 * control endpoint, respond with an ABORT.
658 */
2ce95503
EB
659 net = sock_net(ep->base.sk);
660 if (ep == sctp_sk(net->sctp.ctl_sock)->ep) {
b01a2407 661 SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
ece25dfa 662 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
8190f89d 663 }
1da177e4
LT
664
665 /* Make sure that the COOKIE_ECHO chunk has a valid length.
666 * In this case, we check that we have enough for at least a
667 * chunk header. More detailed verification is done
668 * in sctp_unpack_cookie().
669 */
670 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
671 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
672
609ee467
VY
673 /* If the endpoint is not listening or if the number of associations
674 * on the TCP-style socket exceed the max backlog, respond with an
675 * ABORT.
676 */
677 sk = ep->base.sk;
678 if (!sctp_sstate(sk, LISTENING) ||
679 (sctp_style(sk, TCP) && sk_acceptq_is_full(sk)))
680 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
681
1da177e4
LT
682 /* "Decode" the chunk. We have no optional parameters so we
683 * are in good shape.
684 */
d808ad9a 685 chunk->subh.cookie_hdr =
1da177e4 686 (struct sctp_signed_cookie *)chunk->skb->data;
62b08083
SS
687 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
688 sizeof(sctp_chunkhdr_t)))
689 goto nomem;
1da177e4
LT
690
691 /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
692 * "Z" will reply with a COOKIE ACK chunk after building a TCB
693 * and moving to the ESTABLISHED state.
694 */
695 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
696 &err_chk_p);
697
698 /* FIXME:
699 * If the re-build failed, what is the proper error path
700 * from here?
701 *
702 * [We should abort the association. --piggy]
703 */
704 if (!new_asoc) {
705 /* FIXME: Several errors are possible. A bad cookie should
706 * be silently discarded, but think about logging it too.
707 */
708 switch (error) {
709 case -SCTP_IERROR_NOMEM:
710 goto nomem;
711
712 case -SCTP_IERROR_STALE_COOKIE:
713 sctp_send_stale_cookie_err(ep, asoc, chunk, commands,
714 err_chk_p);
715 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
716
717 case -SCTP_IERROR_BAD_SIG:
718 default:
719 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3ff50b79 720 }
1da177e4
LT
721 }
722
1da177e4 723
df7deeb5
VY
724 /* Delay state machine commands until later.
725 *
726 * Re-build the bind address for the association is done in
1da177e4
LT
727 * the sctp_unpack_cookie() already.
728 */
729 /* This is a brand-new association, so these are not yet side
730 * effects--it is safe to run them here.
731 */
732 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
733
de6becdc 734 if (!sctp_process_init(new_asoc, chunk,
6a1e5f33 735 &chunk->subh.cookie_hdr->c.peer_addr,
1da177e4
LT
736 peer_init, GFP_ATOMIC))
737 goto nomem_init;
738
730fc3d0
VY
739 /* SCTP-AUTH: Now that we've populate required fields in
740 * sctp_process_init, set up the assocaition shared keys as
741 * necessary so that we can potentially authenticate the ACK
742 */
743 error = sctp_auth_asoc_init_active_key(new_asoc, GFP_ATOMIC);
744 if (error)
745 goto nomem_init;
746
bbd0d598
VY
747 /* SCTP-AUTH: auth_chunk pointer is only set when the cookie-echo
748 * is supposed to be authenticated and we have to do delayed
749 * authentication. We've just recreated the association using
750 * the information in the cookie and now it's much easier to
751 * do the authentication.
752 */
753 if (chunk->auth_chunk) {
754 struct sctp_chunk auth;
755 sctp_ierror_t ret;
756
757 /* set-up our fake chunk so that we can process it */
758 auth.skb = chunk->auth_chunk;
759 auth.asoc = chunk->asoc;
760 auth.sctp_hdr = chunk->sctp_hdr;
761 auth.chunk_hdr = (sctp_chunkhdr_t *)skb_push(chunk->auth_chunk,
762 sizeof(sctp_chunkhdr_t));
763 skb_pull(chunk->auth_chunk, sizeof(sctp_chunkhdr_t));
764 auth.transport = chunk->transport;
765
766 ret = sctp_sf_authenticate(ep, new_asoc, type, &auth);
767
768 /* We can now safely free the auth_chunk clone */
769 kfree_skb(chunk->auth_chunk);
770
771 if (ret != SCTP_IERROR_NO_ERROR) {
772 sctp_association_free(new_asoc);
773 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
774 }
775 }
776
1da177e4
LT
777 repl = sctp_make_cookie_ack(new_asoc, chunk);
778 if (!repl)
df7deeb5 779 goto nomem_init;
1da177e4
LT
780
781 /* RFC 2960 5.1 Normal Establishment of an Association
782 *
783 * D) IMPLEMENTATION NOTE: An implementation may choose to
784 * send the Communication Up notification to the SCTP user
785 * upon reception of a valid COOKIE ECHO chunk.
786 */
787 ev = sctp_ulpevent_make_assoc_change(new_asoc, 0, SCTP_COMM_UP, 0,
788 new_asoc->c.sinit_num_ostreams,
789 new_asoc->c.sinit_max_instreams,
a5a35e76 790 NULL, GFP_ATOMIC);
1da177e4
LT
791 if (!ev)
792 goto nomem_ev;
793
d808ad9a 794 /* Sockets API Draft Section 5.3.1.6
0f3fffd8 795 * When a peer sends a Adaptation Layer Indication parameter , SCTP
1da177e4 796 * delivers this notification to inform the application that of the
0f3fffd8 797 * peers requested adaptation layer.
1da177e4 798 */
0f3fffd8
ISJ
799 if (new_asoc->peer.adaptation_ind) {
800 ai_ev = sctp_ulpevent_make_adaptation_indication(new_asoc,
1da177e4 801 GFP_ATOMIC);
df7deeb5
VY
802 if (!ai_ev)
803 goto nomem_aiev;
804 }
805
806 /* Add all the state machine commands now since we've created
807 * everything. This way we don't introduce memory corruptions
808 * during side-effect processing and correclty count established
809 * associations.
810 */
811 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
812 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
813 SCTP_STATE(SCTP_STATE_ESTABLISHED));
b01a2407
EB
814 SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
815 SCTP_INC_STATS(net, SCTP_MIB_PASSIVEESTABS);
df7deeb5
VY
816 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
817
818 if (new_asoc->autoclose)
819 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
820 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
821
df7deeb5
VY
822 /* This will send the COOKIE ACK */
823 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
824
825 /* Queue the ASSOC_CHANGE event */
826 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
827
828 /* Send up the Adaptation Layer Indication event */
829 if (ai_ev)
1da177e4 830 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
df7deeb5 831 SCTP_ULPEVENT(ai_ev));
1da177e4
LT
832
833 return SCTP_DISPOSITION_CONSUME;
834
df7deeb5
VY
835nomem_aiev:
836 sctp_ulpevent_free(ev);
1da177e4
LT
837nomem_ev:
838 sctp_chunk_free(repl);
1da177e4
LT
839nomem_init:
840 sctp_association_free(new_asoc);
841nomem:
842 return SCTP_DISPOSITION_NOMEM;
843}
844
845/*
846 * Respond to a normal COOKIE ACK chunk.
847 * We are the side that is being asked for an association.
848 *
849 * RFC 2960 5.1 Normal Establishment of an Association
850 *
851 * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the
852 * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie
853 * timer. It may also notify its ULP about the successful
854 * establishment of the association with a Communication Up
855 * notification (see Section 10).
856 *
857 * Verification Tag:
858 * Inputs
859 * (endpoint, asoc, chunk)
860 *
861 * Outputs
862 * (asoc, reply_msg, msg_up, timers, counters)
863 *
864 * The return value is the disposition of the chunk.
865 */
866sctp_disposition_t sctp_sf_do_5_1E_ca(const struct sctp_endpoint *ep,
867 const struct sctp_association *asoc,
868 const sctp_subtype_t type, void *arg,
869 sctp_cmd_seq_t *commands)
870{
871 struct sctp_chunk *chunk = arg;
872 struct sctp_ulpevent *ev;
b01a2407 873 struct net *net;
1da177e4
LT
874
875 if (!sctp_vtag_verify(chunk, asoc))
876 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
877
878 /* Verify that the chunk length for the COOKIE-ACK is OK.
879 * If we don't do this, any bundled chunks may be junked.
880 */
881 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
882 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
883 commands);
884
885 /* Reset init error count upon receipt of COOKIE-ACK,
886 * to avoid problems with the managemement of this
887 * counter in stale cookie situations when a transition back
888 * from the COOKIE-ECHOED state to the COOKIE-WAIT
889 * state is performed.
890 */
3f7a87d2 891 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
1da177e4
LT
892
893 /* RFC 2960 5.1 Normal Establishment of an Association
894 *
895 * E) Upon reception of the COOKIE ACK, endpoint "A" will move
896 * from the COOKIE-ECHOED state to the ESTABLISHED state,
897 * stopping the T1-cookie timer.
898 */
899 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
900 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
901 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
902 SCTP_STATE(SCTP_STATE_ESTABLISHED));
b01a2407
EB
903 net = sock_net(ep->base.sk);
904 SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
905 SCTP_INC_STATS(net, SCTP_MIB_ACTIVEESTABS);
1da177e4
LT
906 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
907 if (asoc->autoclose)
908 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
909 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
1da177e4
LT
910
911 /* It may also notify its ULP about the successful
912 * establishment of the association with a Communication Up
913 * notification (see Section 10).
914 */
915 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP,
916 0, asoc->c.sinit_num_ostreams,
917 asoc->c.sinit_max_instreams,
a5a35e76 918 NULL, GFP_ATOMIC);
1da177e4
LT
919
920 if (!ev)
921 goto nomem;
922
923 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
924
925 /* Sockets API Draft Section 5.3.1.6
0f3fffd8 926 * When a peer sends a Adaptation Layer Indication parameter , SCTP
1da177e4 927 * delivers this notification to inform the application that of the
0f3fffd8 928 * peers requested adaptation layer.
1da177e4 929 */
0f3fffd8
ISJ
930 if (asoc->peer.adaptation_ind) {
931 ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
1da177e4
LT
932 if (!ev)
933 goto nomem;
934
935 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
936 SCTP_ULPEVENT(ev));
937 }
938
939 return SCTP_DISPOSITION_CONSUME;
940nomem:
941 return SCTP_DISPOSITION_NOMEM;
942}
943
944/* Generate and sendout a heartbeat packet. */
945static sctp_disposition_t sctp_sf_heartbeat(const struct sctp_endpoint *ep,
946 const struct sctp_association *asoc,
947 const sctp_subtype_t type,
948 void *arg,
949 sctp_cmd_seq_t *commands)
950{
951 struct sctp_transport *transport = (struct sctp_transport *) arg;
952 struct sctp_chunk *reply;
1da177e4
LT
953
954 /* Send a heartbeat to our peer. */
92c73af5 955 reply = sctp_make_heartbeat(asoc, transport);
1da177e4
LT
956 if (!reply)
957 return SCTP_DISPOSITION_NOMEM;
958
959 /* Set rto_pending indicating that an RTT measurement
960 * is started with this heartbeat chunk.
961 */
962 sctp_add_cmd_sf(commands, SCTP_CMD_RTO_PENDING,
963 SCTP_TRANSPORT(transport));
964
965 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
966 return SCTP_DISPOSITION_CONSUME;
967}
968
969/* Generate a HEARTBEAT packet on the given transport. */
970sctp_disposition_t sctp_sf_sendbeat_8_3(const struct sctp_endpoint *ep,
971 const struct sctp_association *asoc,
972 const sctp_subtype_t type,
973 void *arg,
974 sctp_cmd_seq_t *commands)
975{
976 struct sctp_transport *transport = (struct sctp_transport *) arg;
977
b9f84786 978 if (asoc->overall_error_count >= asoc->max_retrans) {
b01a2407 979 struct net *net;
8de8c873
SS
980 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
981 SCTP_ERROR(ETIMEDOUT));
1da177e4
LT
982 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
983 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5be291fe 984 SCTP_PERR(SCTP_ERROR_NO_ERROR));
b01a2407
EB
985 net = sock_net(ep->base.sk);
986 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
987 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
1da177e4
LT
988 return SCTP_DISPOSITION_DELETE_TCB;
989 }
990
991 /* Section 3.3.5.
992 * The Sender-specific Heartbeat Info field should normally include
993 * information about the sender's current time when this HEARTBEAT
994 * chunk is sent and the destination transport address to which this
995 * HEARTBEAT is sent (see Section 8.3).
996 */
997
52ccb8e9 998 if (transport->param_flags & SPP_HB_ENABLE) {
1da177e4
LT
999 if (SCTP_DISPOSITION_NOMEM ==
1000 sctp_sf_heartbeat(ep, asoc, type, arg,
1001 commands))
1002 return SCTP_DISPOSITION_NOMEM;
245cba7e 1003
1da177e4
LT
1004 /* Set transport error counter and association error counter
1005 * when sending heartbeat.
1006 */
7e99013a 1007 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_HB_SENT,
1da177e4
LT
1008 SCTP_TRANSPORT(transport));
1009 }
245cba7e
VY
1010 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_IDLE,
1011 SCTP_TRANSPORT(transport));
1da177e4
LT
1012 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMER_UPDATE,
1013 SCTP_TRANSPORT(transport));
1014
d808ad9a 1015 return SCTP_DISPOSITION_CONSUME;
1da177e4
LT
1016}
1017
1018/*
1019 * Process an heartbeat request.
1020 *
1021 * Section: 8.3 Path Heartbeat
1022 * The receiver of the HEARTBEAT should immediately respond with a
1023 * HEARTBEAT ACK that contains the Heartbeat Information field copied
1024 * from the received HEARTBEAT chunk.
1025 *
1026 * Verification Tag: 8.5 Verification Tag [Normal verification]
1027 * When receiving an SCTP packet, the endpoint MUST ensure that the
1028 * value in the Verification Tag field of the received SCTP packet
1029 * matches its own Tag. If the received Verification Tag value does not
1030 * match the receiver's own tag value, the receiver shall silently
1031 * discard the packet and shall not process it any further except for
1032 * those cases listed in Section 8.5.1 below.
1033 *
1034 * Inputs
1035 * (endpoint, asoc, chunk)
1036 *
1037 * Outputs
1038 * (asoc, reply_msg, msg_up, timers, counters)
1039 *
1040 * The return value is the disposition of the chunk.
1041 */
1042sctp_disposition_t sctp_sf_beat_8_3(const struct sctp_endpoint *ep,
1043 const struct sctp_association *asoc,
1044 const sctp_subtype_t type,
1045 void *arg,
1046 sctp_cmd_seq_t *commands)
1047{
1048 struct sctp_chunk *chunk = arg;
1049 struct sctp_chunk *reply;
1050 size_t paylen = 0;
1051
1052 if (!sctp_vtag_verify(chunk, asoc))
1053 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1054
1055 /* Make sure that the HEARTBEAT chunk has a valid length. */
1056 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t)))
1057 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1058 commands);
1059
1060 /* 8.3 The receiver of the HEARTBEAT should immediately
1061 * respond with a HEARTBEAT ACK that contains the Heartbeat
1062 * Information field copied from the received HEARTBEAT chunk.
1063 */
1064 chunk->subh.hb_hdr = (sctp_heartbeathdr_t *) chunk->skb->data;
1065 paylen = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
62b08083
SS
1066 if (!pskb_pull(chunk->skb, paylen))
1067 goto nomem;
1da177e4
LT
1068
1069 reply = sctp_make_heartbeat_ack(asoc, chunk,
1070 chunk->subh.hb_hdr, paylen);
1071 if (!reply)
1072 goto nomem;
1073
1074 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
1075 return SCTP_DISPOSITION_CONSUME;
1076
1077nomem:
1078 return SCTP_DISPOSITION_NOMEM;
1079}
1080
1081/*
1082 * Process the returning HEARTBEAT ACK.
1083 *
1084 * Section: 8.3 Path Heartbeat
1085 * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT
1086 * should clear the error counter of the destination transport
1087 * address to which the HEARTBEAT was sent, and mark the destination
1088 * transport address as active if it is not so marked. The endpoint may
1089 * optionally report to the upper layer when an inactive destination
1090 * address is marked as active due to the reception of the latest
1091 * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also
1092 * clear the association overall error count as well (as defined
1093 * in section 8.1).
1094 *
1095 * The receiver of the HEARTBEAT ACK should also perform an RTT
1096 * measurement for that destination transport address using the time
1097 * value carried in the HEARTBEAT ACK chunk.
1098 *
1099 * Verification Tag: 8.5 Verification Tag [Normal verification]
1100 *
1101 * Inputs
1102 * (endpoint, asoc, chunk)
1103 *
1104 * Outputs
1105 * (asoc, reply_msg, msg_up, timers, counters)
1106 *
1107 * The return value is the disposition of the chunk.
1108 */
1109sctp_disposition_t sctp_sf_backbeat_8_3(const struct sctp_endpoint *ep,
1110 const struct sctp_association *asoc,
1111 const sctp_subtype_t type,
1112 void *arg,
1113 sctp_cmd_seq_t *commands)
1114{
1115 struct sctp_chunk *chunk = arg;
1116 union sctp_addr from_addr;
1117 struct sctp_transport *link;
1118 sctp_sender_hb_info_t *hbinfo;
1119 unsigned long max_interval;
1120
1121 if (!sctp_vtag_verify(chunk, asoc))
1122 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1123
1124 /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */
dadb50cc
WY
1125 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t) +
1126 sizeof(sctp_sender_hb_info_t)))
1da177e4
LT
1127 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1128 commands);
1129
1130 hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
a601266e
VY
1131 /* Make sure that the length of the parameter is what we expect */
1132 if (ntohs(hbinfo->param_hdr.length) !=
1133 sizeof(sctp_sender_hb_info_t)) {
1134 return SCTP_DISPOSITION_DISCARD;
1135 }
1136
1da177e4 1137 from_addr = hbinfo->daddr;
63de08f4 1138 link = sctp_assoc_lookup_paddr(asoc, &from_addr);
1da177e4
LT
1139
1140 /* This should never happen, but lets log it if so. */
3f7a87d2
FF
1141 if (unlikely(!link)) {
1142 if (from_addr.sa.sa_family == AF_INET6) {
e87cc472
JP
1143 net_warn_ratelimited("%s association %p could not find address %pI6\n",
1144 __func__,
1145 asoc,
1146 &from_addr.v6.sin6_addr);
3f7a87d2 1147 } else {
e87cc472
JP
1148 net_warn_ratelimited("%s association %p could not find address %pI4\n",
1149 __func__,
1150 asoc,
1151 &from_addr.v4.sin_addr.s_addr);
3f7a87d2 1152 }
1da177e4
LT
1153 return SCTP_DISPOSITION_DISCARD;
1154 }
1155
ad8fec17
SS
1156 /* Validate the 64-bit random nonce. */
1157 if (hbinfo->hb_nonce != link->hb_nonce)
1158 return SCTP_DISPOSITION_DISCARD;
1159
52ccb8e9 1160 max_interval = link->hbinterval + link->rto;
1da177e4
LT
1161
1162 /* Check if the timestamp looks valid. */
1163 if (time_after(hbinfo->sent_at, jiffies) ||
1164 time_after(jiffies, hbinfo->sent_at + max_interval)) {
9ee46f1d 1165 SCTP_DEBUG_PRINTK("%s: HEARTBEAT ACK with invalid timestamp "
1da177e4 1166 "received for transport: %p\n",
0dc47877 1167 __func__, link);
1da177e4
LT
1168 return SCTP_DISPOSITION_DISCARD;
1169 }
1170
1171 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of
1172 * the HEARTBEAT should clear the error counter of the
1173 * destination transport address to which the HEARTBEAT was
1174 * sent and mark the destination transport address as active if
1175 * it is not so marked.
1176 */
1177 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_ON, SCTP_TRANSPORT(link));
1178
1179 return SCTP_DISPOSITION_CONSUME;
1180}
1181
1182/* Helper function to send out an abort for the restart
1183 * condition.
1184 */
2ce95503 1185static int sctp_sf_send_restart_abort(struct net *net, union sctp_addr *ssa,
1da177e4
LT
1186 struct sctp_chunk *init,
1187 sctp_cmd_seq_t *commands)
1188{
1189 int len;
1190 struct sctp_packet *pkt;
1191 union sctp_addr_param *addrparm;
1192 struct sctp_errhdr *errhdr;
1193 struct sctp_endpoint *ep;
1194 char buffer[sizeof(struct sctp_errhdr)+sizeof(union sctp_addr_param)];
1195 struct sctp_af *af = sctp_get_af_specific(ssa->v4.sin_family);
1196
1197 /* Build the error on the stack. We are way to malloc crazy
1198 * throughout the code today.
1199 */
1200 errhdr = (struct sctp_errhdr *)buffer;
1201 addrparm = (union sctp_addr_param *)errhdr->variable;
1202
1203 /* Copy into a parm format. */
1204 len = af->to_addr_param(ssa, addrparm);
1205 len += sizeof(sctp_errhdr_t);
1206
1207 errhdr->cause = SCTP_ERROR_RESTART;
1208 errhdr->length = htons(len);
1209
1210 /* Assign to the control socket. */
2ce95503 1211 ep = sctp_sk(net->sctp.ctl_sock)->ep;
1da177e4
LT
1212
1213 /* Association is NULL since this may be a restart attack and we
1214 * want to send back the attacker's vtag.
1215 */
1216 pkt = sctp_abort_pkt_new(ep, NULL, init, errhdr, len);
1217
1218 if (!pkt)
1219 goto out;
1220 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, SCTP_PACKET(pkt));
1221
b01a2407 1222 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
1da177e4
LT
1223
1224 /* Discard the rest of the inbound packet. */
1225 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
1226
1227out:
1228 /* Even if there is no memory, treat as a failure so
1229 * the packet will get dropped.
1230 */
1231 return 0;
1232}
1233
123031c0
JP
1234static bool list_has_sctp_addr(const struct list_head *list,
1235 union sctp_addr *ipaddr)
1236{
1237 struct sctp_transport *addr;
1238
1239 list_for_each_entry(addr, list, transports) {
1240 if (sctp_cmp_addr_exact(ipaddr, &addr->ipaddr))
1241 return true;
1242 }
1243
1244 return false;
1245}
1da177e4
LT
1246/* A restart is occurring, check to make sure no new addresses
1247 * are being added as we may be under a takeover attack.
1248 */
1249static int sctp_sf_check_restart_addrs(const struct sctp_association *new_asoc,
1250 const struct sctp_association *asoc,
1251 struct sctp_chunk *init,
1252 sctp_cmd_seq_t *commands)
1253{
2ce95503 1254 struct net *net = sock_net(new_asoc->base.sk);
123031c0
JP
1255 struct sctp_transport *new_addr;
1256 int ret = 1;
1da177e4 1257
123031c0 1258 /* Implementor's Guide - Section 5.2.2
1da177e4
LT
1259 * ...
1260 * Before responding the endpoint MUST check to see if the
1261 * unexpected INIT adds new addresses to the association. If new
1262 * addresses are added to the association, the endpoint MUST respond
1263 * with an ABORT..
1264 */
1265
1266 /* Search through all current addresses and make sure
1267 * we aren't adding any new ones.
1268 */
9dbc15f0 1269 list_for_each_entry(new_addr, &new_asoc->peer.transport_addr_list,
123031c0
JP
1270 transports) {
1271 if (!list_has_sctp_addr(&asoc->peer.transport_addr_list,
1272 &new_addr->ipaddr)) {
2ce95503 1273 sctp_sf_send_restart_abort(net, &new_addr->ipaddr, init,
123031c0
JP
1274 commands);
1275 ret = 0;
1da177e4 1276 break;
123031c0 1277 }
1da177e4
LT
1278 }
1279
1280 /* Return success if all addresses were found. */
123031c0 1281 return ret;
1da177e4
LT
1282}
1283
1284/* Populate the verification/tie tags based on overlapping INIT
1285 * scenario.
1286 *
1287 * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state.
1288 */
1289static void sctp_tietags_populate(struct sctp_association *new_asoc,
1290 const struct sctp_association *asoc)
1291{
1292 switch (asoc->state) {
1293
1294 /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */
1295
1296 case SCTP_STATE_COOKIE_WAIT:
1297 new_asoc->c.my_vtag = asoc->c.my_vtag;
1298 new_asoc->c.my_ttag = asoc->c.my_vtag;
1299 new_asoc->c.peer_ttag = 0;
1300 break;
1301
1302 case SCTP_STATE_COOKIE_ECHOED:
1303 new_asoc->c.my_vtag = asoc->c.my_vtag;
1304 new_asoc->c.my_ttag = asoc->c.my_vtag;
1305 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1306 break;
1307
1308 /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED,
1309 * COOKIE-WAIT and SHUTDOWN-ACK-SENT
1310 */
1311 default:
1312 new_asoc->c.my_ttag = asoc->c.my_vtag;
1313 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1314 break;
3ff50b79 1315 }
1da177e4
LT
1316
1317 /* Other parameters for the endpoint SHOULD be copied from the
1318 * existing parameters of the association (e.g. number of
1319 * outbound streams) into the INIT ACK and cookie.
1320 */
1321 new_asoc->rwnd = asoc->rwnd;
1322 new_asoc->c.sinit_num_ostreams = asoc->c.sinit_num_ostreams;
1323 new_asoc->c.sinit_max_instreams = asoc->c.sinit_max_instreams;
1324 new_asoc->c.initial_tsn = asoc->c.initial_tsn;
1325}
1326
1327/*
1328 * Compare vtag/tietag values to determine unexpected COOKIE-ECHO
1329 * handling action.
1330 *
1331 * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists.
1332 *
1333 * Returns value representing action to be taken. These action values
1334 * correspond to Action/Description values in RFC 2960, Table 2.
1335 */
1336static char sctp_tietags_compare(struct sctp_association *new_asoc,
1337 const struct sctp_association *asoc)
1338{
1339 /* In this case, the peer may have restarted. */
1340 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1341 (asoc->c.peer_vtag != new_asoc->c.peer_vtag) &&
1342 (asoc->c.my_vtag == new_asoc->c.my_ttag) &&
1343 (asoc->c.peer_vtag == new_asoc->c.peer_ttag))
1344 return 'A';
1345
1346 /* Collision case B. */
1347 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1348 ((asoc->c.peer_vtag != new_asoc->c.peer_vtag) ||
1349 (0 == asoc->c.peer_vtag))) {
1350 return 'B';
1351 }
1352
1353 /* Collision case D. */
1354 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1355 (asoc->c.peer_vtag == new_asoc->c.peer_vtag))
1356 return 'D';
1357
1358 /* Collision case C. */
1359 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1360 (asoc->c.peer_vtag == new_asoc->c.peer_vtag) &&
1361 (0 == new_asoc->c.my_ttag) &&
1362 (0 == new_asoc->c.peer_ttag))
1363 return 'C';
1364
1365 /* No match to any of the special cases; discard this packet. */
1366 return 'E';
1367}
1368
1369/* Common helper routine for both duplicate and simulataneous INIT
1370 * chunk handling.
1371 */
1372static sctp_disposition_t sctp_sf_do_unexpected_init(
1373 const struct sctp_endpoint *ep,
1374 const struct sctp_association *asoc,
1375 const sctp_subtype_t type,
1376 void *arg, sctp_cmd_seq_t *commands)
1377{
1378 sctp_disposition_t retval;
1379 struct sctp_chunk *chunk = arg;
1380 struct sctp_chunk *repl;
1381 struct sctp_association *new_asoc;
1382 struct sctp_chunk *err_chunk;
1383 struct sctp_packet *packet;
1384 sctp_unrecognized_param_t *unk_param;
1385 int len;
1386
1387 /* 6.10 Bundling
1388 * An endpoint MUST NOT bundle INIT, INIT ACK or
1389 * SHUTDOWN COMPLETE with any other chunks.
1390 *
1391 * IG Section 2.11.2
1392 * Furthermore, we require that the receiver of an INIT chunk MUST
1393 * enforce these rules by silently discarding an arriving packet
1394 * with an INIT chunk that is bundled with other chunks.
1395 */
1396 if (!chunk->singleton)
1397 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1398
1399 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
d808ad9a 1400 * Tag.
1da177e4
LT
1401 */
1402 if (chunk->sctp_hdr->vtag != 0)
1403 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
1404
1405 /* Make sure that the INIT chunk has a valid length.
1406 * In this case, we generate a protocol violation since we have
1407 * an association established.
1408 */
1409 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
1410 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1411 commands);
1412 /* Grab the INIT header. */
1413 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
1414
1415 /* Tag the variable length parameters. */
1416 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
1417
1418 /* Verify the INIT chunk before processing it. */
1419 err_chunk = NULL;
1420 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
1421 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
1422 &err_chunk)) {
1423 /* This chunk contains fatal error. It is to be discarded.
1424 * Send an ABORT, with causes if there is any.
1425 */
1426 if (err_chunk) {
1427 packet = sctp_abort_pkt_new(ep, asoc, arg,
1428 (__u8 *)(err_chunk->chunk_hdr) +
1429 sizeof(sctp_chunkhdr_t),
1430 ntohs(err_chunk->chunk_hdr->length) -
1431 sizeof(sctp_chunkhdr_t));
1432
1433 if (packet) {
1434 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
1435 SCTP_PACKET(packet));
b01a2407 1436 SCTP_INC_STATS(sock_net(ep->base.sk), SCTP_MIB_OUTCTRLCHUNKS);
1da177e4
LT
1437 retval = SCTP_DISPOSITION_CONSUME;
1438 } else {
1439 retval = SCTP_DISPOSITION_NOMEM;
1440 }
1441 goto cleanup;
1442 } else {
1443 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg,
1444 commands);
1445 }
1446 }
1447
1448 /*
1449 * Other parameters for the endpoint SHOULD be copied from the
1450 * existing parameters of the association (e.g. number of
1451 * outbound streams) into the INIT ACK and cookie.
1452 * FIXME: We are copying parameters from the endpoint not the
1453 * association.
1454 */
1455 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
1456 if (!new_asoc)
1457 goto nomem;
1458
409b95af
VY
1459 if (sctp_assoc_set_bind_addr_from_ep(new_asoc,
1460 sctp_scope(sctp_source(chunk)), GFP_ATOMIC) < 0)
1461 goto nomem;
1462
1da177e4
LT
1463 /* In the outbound INIT ACK the endpoint MUST copy its current
1464 * Verification Tag and Peers Verification tag into a reserved
1465 * place (local tie-tag and per tie-tag) within the state cookie.
1466 */
de6becdc 1467 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk),
1da177e4 1468 (sctp_init_chunk_t *)chunk->chunk_hdr,
df7deeb5
VY
1469 GFP_ATOMIC))
1470 goto nomem;
1da177e4
LT
1471
1472 /* Make sure no new addresses are being added during the
1473 * restart. Do not do this check for COOKIE-WAIT state,
1474 * since there are no peer addresses to check against.
1475 * Upon return an ABORT will have been sent if needed.
1476 */
1477 if (!sctp_state(asoc, COOKIE_WAIT)) {
1478 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk,
1479 commands)) {
1480 retval = SCTP_DISPOSITION_CONSUME;
df7deeb5 1481 goto nomem_retval;
1da177e4
LT
1482 }
1483 }
1484
1485 sctp_tietags_populate(new_asoc, asoc);
1486
1487 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
1488
1489 /* If there are errors need to be reported for unknown parameters,
1490 * make sure to reserve enough room in the INIT ACK for them.
1491 */
1492 len = 0;
1493 if (err_chunk) {
1494 len = ntohs(err_chunk->chunk_hdr->length) -
1495 sizeof(sctp_chunkhdr_t);
1496 }
1497
1da177e4
LT
1498 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
1499 if (!repl)
1500 goto nomem;
1501
1502 /* If there are errors need to be reported for unknown parameters,
1503 * include them in the outgoing INIT ACK as "Unrecognized parameter"
1504 * parameter.
1505 */
1506 if (err_chunk) {
1507 /* Get the "Unrecognized parameter" parameter(s) out of the
1508 * ERROR chunk generated by sctp_verify_init(). Since the
1509 * error cause code for "unknown parameter" and the
1510 * "Unrecognized parameter" type is the same, we can
1511 * construct the parameters in INIT ACK by copying the
1512 * ERROR causes over.
1513 */
1514 unk_param = (sctp_unrecognized_param_t *)
1515 ((__u8 *)(err_chunk->chunk_hdr) +
1516 sizeof(sctp_chunkhdr_t));
1517 /* Replace the cause code with the "Unrecognized parameter"
1518 * parameter type.
1519 */
1520 sctp_addto_chunk(repl, len, unk_param);
1521 }
1522
1523 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
1524 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1525
1526 /*
1527 * Note: After sending out INIT ACK with the State Cookie parameter,
1528 * "Z" MUST NOT allocate any resources for this new association.
1529 * Otherwise, "Z" will be vulnerable to resource attacks.
1530 */
1531 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
1532 retval = SCTP_DISPOSITION_CONSUME;
1533
df7deeb5
VY
1534 return retval;
1535
1536nomem:
1537 retval = SCTP_DISPOSITION_NOMEM;
1538nomem_retval:
1539 if (new_asoc)
1540 sctp_association_free(new_asoc);
1da177e4
LT
1541cleanup:
1542 if (err_chunk)
1543 sctp_chunk_free(err_chunk);
1544 return retval;
1da177e4
LT
1545}
1546
1547/*
25985edc 1548 * Handle simultaneous INIT.
1da177e4
LT
1549 * This means we started an INIT and then we got an INIT request from
1550 * our peer.
1551 *
1552 * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B)
1553 * This usually indicates an initialization collision, i.e., each
1554 * endpoint is attempting, at about the same time, to establish an
1555 * association with the other endpoint.
1556 *
1557 * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an
1558 * endpoint MUST respond with an INIT ACK using the same parameters it
1559 * sent in its original INIT chunk (including its Verification Tag,
1560 * unchanged). These original parameters are combined with those from the
1561 * newly received INIT chunk. The endpoint shall also generate a State
1562 * Cookie with the INIT ACK. The endpoint uses the parameters sent in its
1563 * INIT to calculate the State Cookie.
1564 *
1565 * After that, the endpoint MUST NOT change its state, the T1-init
1566 * timer shall be left running and the corresponding TCB MUST NOT be
1567 * destroyed. The normal procedures for handling State Cookies when
1568 * a TCB exists will resolve the duplicate INITs to a single association.
1569 *
1570 * For an endpoint that is in the COOKIE-ECHOED state it MUST populate
1571 * its Tie-Tags with the Tag information of itself and its peer (see
1572 * section 5.2.2 for a description of the Tie-Tags).
1573 *
1574 * Verification Tag: Not explicit, but an INIT can not have a valid
1575 * verification tag, so we skip the check.
1576 *
1577 * Inputs
1578 * (endpoint, asoc, chunk)
1579 *
1580 * Outputs
1581 * (asoc, reply_msg, msg_up, timers, counters)
1582 *
1583 * The return value is the disposition of the chunk.
1584 */
1585sctp_disposition_t sctp_sf_do_5_2_1_siminit(const struct sctp_endpoint *ep,
1586 const struct sctp_association *asoc,
1587 const sctp_subtype_t type,
1588 void *arg,
1589 sctp_cmd_seq_t *commands)
1590{
1591 /* Call helper to do the real work for both simulataneous and
1592 * duplicate INIT chunk handling.
1593 */
1594 return sctp_sf_do_unexpected_init(ep, asoc, type, arg, commands);
1595}
1596
1597/*
1598 * Handle duplicated INIT messages. These are usually delayed
1599 * restransmissions.
1600 *
1601 * Section: 5.2.2 Unexpected INIT in States Other than CLOSED,
1602 * COOKIE-ECHOED and COOKIE-WAIT
1603 *
1604 * Unless otherwise stated, upon reception of an unexpected INIT for
1605 * this association, the endpoint shall generate an INIT ACK with a
1606 * State Cookie. In the outbound INIT ACK the endpoint MUST copy its
1607 * current Verification Tag and peer's Verification Tag into a reserved
1608 * place within the state cookie. We shall refer to these locations as
1609 * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet
1610 * containing this INIT ACK MUST carry a Verification Tag value equal to
1611 * the Initiation Tag found in the unexpected INIT. And the INIT ACK
1612 * MUST contain a new Initiation Tag (randomly generated see Section
1613 * 5.3.1). Other parameters for the endpoint SHOULD be copied from the
1614 * existing parameters of the association (e.g. number of outbound
1615 * streams) into the INIT ACK and cookie.
1616 *
1617 * After sending out the INIT ACK, the endpoint shall take no further
1618 * actions, i.e., the existing association, including its current state,
1619 * and the corresponding TCB MUST NOT be changed.
1620 *
1621 * Note: Only when a TCB exists and the association is not in a COOKIE-
1622 * WAIT state are the Tie-Tags populated. For a normal association INIT
1623 * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be
1624 * set to 0 (indicating that no previous TCB existed). The INIT ACK and
1625 * State Cookie are populated as specified in section 5.2.1.
1626 *
1627 * Verification Tag: Not specified, but an INIT has no way of knowing
1628 * what the verification tag could be, so we ignore it.
1629 *
1630 * Inputs
1631 * (endpoint, asoc, chunk)
1632 *
1633 * Outputs
1634 * (asoc, reply_msg, msg_up, timers, counters)
1635 *
1636 * The return value is the disposition of the chunk.
1637 */
1638sctp_disposition_t sctp_sf_do_5_2_2_dupinit(const struct sctp_endpoint *ep,
1639 const struct sctp_association *asoc,
1640 const sctp_subtype_t type,
1641 void *arg,
1642 sctp_cmd_seq_t *commands)
1643{
1644 /* Call helper to do the real work for both simulataneous and
1645 * duplicate INIT chunk handling.
1646 */
1647 return sctp_sf_do_unexpected_init(ep, asoc, type, arg, commands);
1648}
1649
1650
610ab73a
VY
1651/*
1652 * Unexpected INIT-ACK handler.
1653 *
1654 * Section 5.2.3
1655 * If an INIT ACK received by an endpoint in any state other than the
1656 * COOKIE-WAIT state, the endpoint should discard the INIT ACK chunk.
1657 * An unexpected INIT ACK usually indicates the processing of an old or
1658 * duplicated INIT chunk.
1659*/
1660sctp_disposition_t sctp_sf_do_5_2_3_initack(const struct sctp_endpoint *ep,
1661 const struct sctp_association *asoc,
1662 const sctp_subtype_t type,
1663 void *arg, sctp_cmd_seq_t *commands)
1664{
2ce95503 1665 struct net *net = sock_net(ep->base.sk);
610ab73a
VY
1666 /* Per the above section, we'll discard the chunk if we have an
1667 * endpoint. If this is an OOTB INIT-ACK, treat it as such.
1668 */
2ce95503 1669 if (ep == sctp_sk(net->sctp.ctl_sock)->ep)
610ab73a
VY
1670 return sctp_sf_ootb(ep, asoc, type, arg, commands);
1671 else
1672 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
1673}
1da177e4
LT
1674
1675/* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A')
1676 *
1677 * Section 5.2.4
1678 * A) In this case, the peer may have restarted.
1679 */
1680static sctp_disposition_t sctp_sf_do_dupcook_a(const struct sctp_endpoint *ep,
1681 const struct sctp_association *asoc,
1682 struct sctp_chunk *chunk,
1683 sctp_cmd_seq_t *commands,
1684 struct sctp_association *new_asoc)
1685{
1686 sctp_init_chunk_t *peer_init;
1687 struct sctp_ulpevent *ev;
1688 struct sctp_chunk *repl;
1689 struct sctp_chunk *err;
1690 sctp_disposition_t disposition;
1691
1692 /* new_asoc is a brand-new association, so these are not yet
1693 * side effects--it is safe to run them here.
1694 */
1695 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1696
de6becdc 1697 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), peer_init,
1da177e4
LT
1698 GFP_ATOMIC))
1699 goto nomem;
1700
1701 /* Make sure no new addresses are being added during the
1702 * restart. Though this is a pretty complicated attack
1703 * since you'd have to get inside the cookie.
1704 */
1705 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk, commands)) {
1706 return SCTP_DISPOSITION_CONSUME;
1707 }
1708
1709 /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes
1710 * the peer has restarted (Action A), it MUST NOT setup a new
1711 * association but instead resend the SHUTDOWN ACK and send an ERROR
1712 * chunk with a "Cookie Received while Shutting Down" error cause to
1713 * its peer.
1714 */
1715 if (sctp_state(asoc, SHUTDOWN_ACK_SENT)) {
1716 disposition = sctp_sf_do_9_2_reshutack(ep, asoc,
1717 SCTP_ST_CHUNK(chunk->chunk_hdr->type),
1718 chunk, commands);
1719 if (SCTP_DISPOSITION_NOMEM == disposition)
1720 goto nomem;
1721
1722 err = sctp_make_op_error(asoc, chunk,
1723 SCTP_ERROR_COOKIE_IN_SHUTDOWN,
6383cfb3 1724 NULL, 0, 0);
1da177e4
LT
1725 if (err)
1726 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1727 SCTP_CHUNK(err));
1728
1729 return SCTP_DISPOSITION_CONSUME;
1730 }
1731
a000c01e
WY
1732 /* For now, stop pending T3-rtx and SACK timers, fail any unsent/unacked
1733 * data. Consider the optional choice of resending of this data.
1da177e4 1734 */
a000c01e
WY
1735 sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
1736 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1737 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
1da177e4
LT
1738 sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_OUTQUEUE, SCTP_NULL());
1739
a000c01e
WY
1740 /* Stop pending T4-rto timer, teardown ASCONF queue, ASCONF-ACK queue
1741 * and ASCONF-ACK cache.
1742 */
1743 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1744 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
1745 sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_ASCONF_QUEUE, SCTP_NULL());
1746
1da177e4
LT
1747 repl = sctp_make_cookie_ack(new_asoc, chunk);
1748 if (!repl)
1749 goto nomem;
1750
1da177e4
LT
1751 /* Report association restart to upper layer. */
1752 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_RESTART, 0,
1753 new_asoc->c.sinit_num_ostreams,
1754 new_asoc->c.sinit_max_instreams,
a5a35e76 1755 NULL, GFP_ATOMIC);
1da177e4
LT
1756 if (!ev)
1757 goto nomem_ev;
1758
df7deeb5
VY
1759 /* Update the content of current association. */
1760 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1761 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1da177e4
LT
1762 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
1763 return SCTP_DISPOSITION_CONSUME;
1764
1765nomem_ev:
1766 sctp_chunk_free(repl);
1767nomem:
1768 return SCTP_DISPOSITION_NOMEM;
1769}
1770
1771/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B')
1772 *
1773 * Section 5.2.4
1774 * B) In this case, both sides may be attempting to start an association
1775 * at about the same time but the peer endpoint started its INIT
1776 * after responding to the local endpoint's INIT
1777 */
1778/* This case represents an initialization collision. */
1779static sctp_disposition_t sctp_sf_do_dupcook_b(const struct sctp_endpoint *ep,
1780 const struct sctp_association *asoc,
1781 struct sctp_chunk *chunk,
1782 sctp_cmd_seq_t *commands,
1783 struct sctp_association *new_asoc)
1784{
1785 sctp_init_chunk_t *peer_init;
1da177e4
LT
1786 struct sctp_chunk *repl;
1787
1788 /* new_asoc is a brand-new association, so these are not yet
1789 * side effects--it is safe to run them here.
1790 */
1791 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
de6becdc 1792 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), peer_init,
1da177e4
LT
1793 GFP_ATOMIC))
1794 goto nomem;
1795
1796 /* Update the content of current association. */
1797 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1798 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1799 SCTP_STATE(SCTP_STATE_ESTABLISHED));
b01a2407 1800 SCTP_INC_STATS(sock_net(new_asoc->base.sk), SCTP_MIB_CURRESTAB);
1da177e4
LT
1801 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
1802
1803 repl = sctp_make_cookie_ack(new_asoc, chunk);
1804 if (!repl)
1805 goto nomem;
1806
1807 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1da177e4
LT
1808
1809 /* RFC 2960 5.1 Normal Establishment of an Association
1810 *
1811 * D) IMPLEMENTATION NOTE: An implementation may choose to
1812 * send the Communication Up notification to the SCTP user
1813 * upon reception of a valid COOKIE ECHO chunk.
07d93967
VY
1814 *
1815 * Sadly, this needs to be implemented as a side-effect, because
1816 * we are not guaranteed to have set the association id of the real
1817 * association and so these notifications need to be delayed until
1818 * the association id is allocated.
1da177e4 1819 */
1da177e4 1820
07d93967 1821 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_CHANGE, SCTP_U8(SCTP_COMM_UP));
1da177e4
LT
1822
1823 /* Sockets API Draft Section 5.3.1.6
0f3fffd8 1824 * When a peer sends a Adaptation Layer Indication parameter , SCTP
1da177e4 1825 * delivers this notification to inform the application that of the
0f3fffd8 1826 * peers requested adaptation layer.
07d93967
VY
1827 *
1828 * This also needs to be done as a side effect for the same reason as
1829 * above.
1da177e4 1830 */
07d93967
VY
1831 if (asoc->peer.adaptation_ind)
1832 sctp_add_cmd_sf(commands, SCTP_CMD_ADAPTATION_IND, SCTP_NULL());
1da177e4
LT
1833
1834 return SCTP_DISPOSITION_CONSUME;
1835
1da177e4
LT
1836nomem:
1837 return SCTP_DISPOSITION_NOMEM;
1838}
1839
1840/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C')
1841 *
1842 * Section 5.2.4
1843 * C) In this case, the local endpoint's cookie has arrived late.
1844 * Before it arrived, the local endpoint sent an INIT and received an
1845 * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag
1846 * but a new tag of its own.
1847 */
1848/* This case represents an initialization collision. */
1849static sctp_disposition_t sctp_sf_do_dupcook_c(const struct sctp_endpoint *ep,
1850 const struct sctp_association *asoc,
1851 struct sctp_chunk *chunk,
1852 sctp_cmd_seq_t *commands,
1853 struct sctp_association *new_asoc)
1854{
1855 /* The cookie should be silently discarded.
1856 * The endpoint SHOULD NOT change states and should leave
1857 * any timers running.
1858 */
1859 return SCTP_DISPOSITION_DISCARD;
1860}
1861
1862/* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D')
1863 *
1864 * Section 5.2.4
1865 *
1866 * D) When both local and remote tags match the endpoint should always
1867 * enter the ESTABLISHED state, if it has not already done so.
1868 */
1869/* This case represents an initialization collision. */
1870static sctp_disposition_t sctp_sf_do_dupcook_d(const struct sctp_endpoint *ep,
1871 const struct sctp_association *asoc,
1872 struct sctp_chunk *chunk,
1873 sctp_cmd_seq_t *commands,
1874 struct sctp_association *new_asoc)
1875{
df7deeb5 1876 struct sctp_ulpevent *ev = NULL, *ai_ev = NULL;
1da177e4
LT
1877 struct sctp_chunk *repl;
1878
1879 /* Clarification from Implementor's Guide:
1880 * D) When both local and remote tags match the endpoint should
d808ad9a
YH
1881 * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state.
1882 * It should stop any cookie timer that may be running and send
1883 * a COOKIE ACK.
1da177e4
LT
1884 */
1885
1886 /* Don't accidentally move back into established state. */
1887 if (asoc->state < SCTP_STATE_ESTABLISHED) {
1888 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1889 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1890 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1891 SCTP_STATE(SCTP_STATE_ESTABLISHED));
b01a2407 1892 SCTP_INC_STATS(sock_net(asoc->base.sk), SCTP_MIB_CURRESTAB);
1da177e4
LT
1893 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START,
1894 SCTP_NULL());
1895
1896 /* RFC 2960 5.1 Normal Establishment of an Association
1897 *
1898 * D) IMPLEMENTATION NOTE: An implementation may choose
1899 * to send the Communication Up notification to the
1900 * SCTP user upon reception of a valid COOKIE
1901 * ECHO chunk.
1902 */
df7deeb5 1903 ev = sctp_ulpevent_make_assoc_change(asoc, 0,
1da177e4 1904 SCTP_COMM_UP, 0,
df7deeb5
VY
1905 asoc->c.sinit_num_ostreams,
1906 asoc->c.sinit_max_instreams,
9cbcbf4e 1907 NULL, GFP_ATOMIC);
1da177e4
LT
1908 if (!ev)
1909 goto nomem;
1da177e4
LT
1910
1911 /* Sockets API Draft Section 5.3.1.6
0f3fffd8 1912 * When a peer sends a Adaptation Layer Indication parameter,
1da177e4 1913 * SCTP delivers this notification to inform the application
0f3fffd8 1914 * that of the peers requested adaptation layer.
1da177e4 1915 */
0f3fffd8
ISJ
1916 if (asoc->peer.adaptation_ind) {
1917 ai_ev = sctp_ulpevent_make_adaptation_indication(asoc,
1da177e4 1918 GFP_ATOMIC);
df7deeb5 1919 if (!ai_ev)
1da177e4
LT
1920 goto nomem;
1921
1da177e4
LT
1922 }
1923 }
1da177e4
LT
1924
1925 repl = sctp_make_cookie_ack(new_asoc, chunk);
1926 if (!repl)
1927 goto nomem;
1928
2e3216cd
VY
1929 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1930
df7deeb5
VY
1931 if (ev)
1932 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1933 SCTP_ULPEVENT(ev));
1934 if (ai_ev)
1935 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1936 SCTP_ULPEVENT(ai_ev));
1937
1da177e4
LT
1938 return SCTP_DISPOSITION_CONSUME;
1939
1940nomem:
df7deeb5
VY
1941 if (ai_ev)
1942 sctp_ulpevent_free(ai_ev);
1da177e4
LT
1943 if (ev)
1944 sctp_ulpevent_free(ev);
1945 return SCTP_DISPOSITION_NOMEM;
1946}
1947
1948/*
1949 * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying
1950 * chunk was retransmitted and then delayed in the network.
1951 *
1952 * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists
1953 *
1954 * Verification Tag: None. Do cookie validation.
1955 *
1956 * Inputs
1957 * (endpoint, asoc, chunk)
1958 *
1959 * Outputs
1960 * (asoc, reply_msg, msg_up, timers, counters)
1961 *
1962 * The return value is the disposition of the chunk.
1963 */
1964sctp_disposition_t sctp_sf_do_5_2_4_dupcook(const struct sctp_endpoint *ep,
1965 const struct sctp_association *asoc,
1966 const sctp_subtype_t type,
1967 void *arg,
1968 sctp_cmd_seq_t *commands)
1969{
1970 sctp_disposition_t retval;
1971 struct sctp_chunk *chunk = arg;
1972 struct sctp_association *new_asoc;
1973 int error = 0;
1974 char action;
1975 struct sctp_chunk *err_chk_p;
1976
1977 /* Make sure that the chunk has a valid length from the protocol
1978 * perspective. In this case check to make sure we have at least
1979 * enough for the chunk header. Cookie length verification is
1980 * done later.
1981 */
1982 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
1983 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1984 commands);
1985
1986 /* "Decode" the chunk. We have no optional parameters so we
1987 * are in good shape.
1988 */
d808ad9a 1989 chunk->subh.cookie_hdr = (struct sctp_signed_cookie *)chunk->skb->data;
62b08083
SS
1990 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
1991 sizeof(sctp_chunkhdr_t)))
1992 goto nomem;
1da177e4
LT
1993
1994 /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
1995 * of a duplicate COOKIE ECHO match the Verification Tags of the
1996 * current association, consider the State Cookie valid even if
1997 * the lifespan is exceeded.
1998 */
1999 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
2000 &err_chk_p);
2001
2002 /* FIXME:
2003 * If the re-build failed, what is the proper error path
2004 * from here?
2005 *
2006 * [We should abort the association. --piggy]
2007 */
2008 if (!new_asoc) {
2009 /* FIXME: Several errors are possible. A bad cookie should
2010 * be silently discarded, but think about logging it too.
2011 */
2012 switch (error) {
2013 case -SCTP_IERROR_NOMEM:
2014 goto nomem;
2015
2016 case -SCTP_IERROR_STALE_COOKIE:
2017 sctp_send_stale_cookie_err(ep, asoc, chunk, commands,
2018 err_chk_p);
2019 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2020 case -SCTP_IERROR_BAD_SIG:
2021 default:
2022 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3ff50b79 2023 }
1da177e4
LT
2024 }
2025
2026 /* Compare the tie_tag in cookie with the verification tag of
2027 * current association.
2028 */
2029 action = sctp_tietags_compare(new_asoc, asoc);
2030
2031 switch (action) {
2032 case 'A': /* Association restart. */
2033 retval = sctp_sf_do_dupcook_a(ep, asoc, chunk, commands,
2034 new_asoc);
2035 break;
2036
2037 case 'B': /* Collision case B. */
2038 retval = sctp_sf_do_dupcook_b(ep, asoc, chunk, commands,
2039 new_asoc);
2040 break;
2041
2042 case 'C': /* Collision case C. */
2043 retval = sctp_sf_do_dupcook_c(ep, asoc, chunk, commands,
2044 new_asoc);
2045 break;
2046
2047 case 'D': /* Collision case D. */
2048 retval = sctp_sf_do_dupcook_d(ep, asoc, chunk, commands,
2049 new_asoc);
2050 break;
2051
2052 default: /* Discard packet for all others. */
2053 retval = sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2054 break;
3ff50b79 2055 }
1da177e4
LT
2056
2057 /* Delete the tempory new association. */
2058 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
2059 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
2060
d5ccd496
MM
2061 /* Restore association pointer to provide SCTP command interpeter
2062 * with a valid context in case it needs to manipulate
2063 * the queues */
2064 sctp_add_cmd_sf(commands, SCTP_CMD_SET_ASOC,
2065 SCTP_ASOC((struct sctp_association *)asoc));
2066
1da177e4
LT
2067 return retval;
2068
2069nomem:
2070 return SCTP_DISPOSITION_NOMEM;
2071}
2072
2073/*
2074 * Process an ABORT. (SHUTDOWN-PENDING state)
2075 *
2076 * See sctp_sf_do_9_1_abort().
2077 */
2078sctp_disposition_t sctp_sf_shutdown_pending_abort(
2079 const struct sctp_endpoint *ep,
2080 const struct sctp_association *asoc,
2081 const sctp_subtype_t type,
2082 void *arg,
2083 sctp_cmd_seq_t *commands)
2084{
2085 struct sctp_chunk *chunk = arg;
2086
2087 if (!sctp_vtag_verify_either(chunk, asoc))
2088 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2089
2090 /* Make sure that the ABORT chunk has a valid length.
2091 * Since this is an ABORT chunk, we have to discard it
2092 * because of the following text:
2093 * RFC 2960, Section 3.3.7
2094 * If an endpoint receives an ABORT with a format error or for an
2095 * association that doesn't exist, it MUST silently discard it.
25985edc 2096 * Because the length is "invalid", we can't really discard just
1da177e4
LT
2097 * as we do not know its true length. So, to be safe, discard the
2098 * packet.
2099 */
2100 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2101 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2102
75205f47
VY
2103 /* ADD-IP: Special case for ABORT chunks
2104 * F4) One special consideration is that ABORT Chunks arriving
2105 * destined to the IP address being deleted MUST be
2106 * ignored (see Section 5.3.1 for further details).
2107 */
2108 if (SCTP_ADDR_DEL ==
2109 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2110 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
2111
75205f47 2112 return __sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
1da177e4
LT
2113}
2114
2115/*
2116 * Process an ABORT. (SHUTDOWN-SENT state)
2117 *
2118 * See sctp_sf_do_9_1_abort().
2119 */
2120sctp_disposition_t sctp_sf_shutdown_sent_abort(const struct sctp_endpoint *ep,
2121 const struct sctp_association *asoc,
2122 const sctp_subtype_t type,
2123 void *arg,
2124 sctp_cmd_seq_t *commands)
2125{
2126 struct sctp_chunk *chunk = arg;
2127
2128 if (!sctp_vtag_verify_either(chunk, asoc))
2129 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2130
2131 /* Make sure that the ABORT chunk has a valid length.
2132 * Since this is an ABORT chunk, we have to discard it
2133 * because of the following text:
2134 * RFC 2960, Section 3.3.7
2135 * If an endpoint receives an ABORT with a format error or for an
2136 * association that doesn't exist, it MUST silently discard it.
25985edc 2137 * Because the length is "invalid", we can't really discard just
1da177e4
LT
2138 * as we do not know its true length. So, to be safe, discard the
2139 * packet.
2140 */
2141 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2142 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2143
75205f47
VY
2144 /* ADD-IP: Special case for ABORT chunks
2145 * F4) One special consideration is that ABORT Chunks arriving
2146 * destined to the IP address being deleted MUST be
2147 * ignored (see Section 5.3.1 for further details).
2148 */
2149 if (SCTP_ADDR_DEL ==
2150 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2151 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
2152
1da177e4
LT
2153 /* Stop the T2-shutdown timer. */
2154 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2155 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2156
2157 /* Stop the T5-shutdown guard timer. */
2158 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2159 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
2160
75205f47 2161 return __sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
1da177e4
LT
2162}
2163
2164/*
2165 * Process an ABORT. (SHUTDOWN-ACK-SENT state)
2166 *
2167 * See sctp_sf_do_9_1_abort().
2168 */
2169sctp_disposition_t sctp_sf_shutdown_ack_sent_abort(
2170 const struct sctp_endpoint *ep,
2171 const struct sctp_association *asoc,
2172 const sctp_subtype_t type,
2173 void *arg,
2174 sctp_cmd_seq_t *commands)
2175{
2176 /* The same T2 timer, so we should be able to use
2177 * common function with the SHUTDOWN-SENT state.
2178 */
2179 return sctp_sf_shutdown_sent_abort(ep, asoc, type, arg, commands);
2180}
2181
2182/*
2183 * Handle an Error received in COOKIE_ECHOED state.
2184 *
2185 * Only handle the error type of stale COOKIE Error, the other errors will
2186 * be ignored.
2187 *
2188 * Inputs
2189 * (endpoint, asoc, chunk)
2190 *
2191 * Outputs
2192 * (asoc, reply_msg, msg_up, timers, counters)
2193 *
2194 * The return value is the disposition of the chunk.
2195 */
2196sctp_disposition_t sctp_sf_cookie_echoed_err(const struct sctp_endpoint *ep,
2197 const struct sctp_association *asoc,
2198 const sctp_subtype_t type,
2199 void *arg,
2200 sctp_cmd_seq_t *commands)
2201{
2202 struct sctp_chunk *chunk = arg;
2203 sctp_errhdr_t *err;
2204
2205 if (!sctp_vtag_verify(chunk, asoc))
2206 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2207
2208 /* Make sure that the ERROR chunk has a valid length.
2209 * The parameter walking depends on this as well.
2210 */
2211 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
2212 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2213 commands);
2214
2215 /* Process the error here */
2216 /* FUTURE FIXME: When PR-SCTP related and other optional
2217 * parms are emitted, this will have to change to handle multiple
2218 * errors.
2219 */
2220 sctp_walk_errors(err, chunk->chunk_hdr) {
2221 if (SCTP_ERROR_STALE_COOKIE == err->cause)
d808ad9a 2222 return sctp_sf_do_5_2_6_stale(ep, asoc, type,
1da177e4
LT
2223 arg, commands);
2224 }
2225
2226 /* It is possible to have malformed error causes, and that
2227 * will cause us to end the walk early. However, since
2228 * we are discarding the packet, there should be no adverse
2229 * affects.
2230 */
2231 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2232}
2233
2234/*
2235 * Handle a Stale COOKIE Error
2236 *
2237 * Section: 5.2.6 Handle Stale COOKIE Error
2238 * If the association is in the COOKIE-ECHOED state, the endpoint may elect
2239 * one of the following three alternatives.
2240 * ...
2241 * 3) Send a new INIT chunk to the endpoint, adding a Cookie
2242 * Preservative parameter requesting an extension to the lifetime of
2243 * the State Cookie. When calculating the time extension, an
2244 * implementation SHOULD use the RTT information measured based on the
2245 * previous COOKIE ECHO / ERROR exchange, and should add no more
2246 * than 1 second beyond the measured RTT, due to long State Cookie
2247 * lifetimes making the endpoint more subject to a replay attack.
2248 *
2249 * Verification Tag: Not explicit, but safe to ignore.
2250 *
2251 * Inputs
2252 * (endpoint, asoc, chunk)
2253 *
2254 * Outputs
2255 * (asoc, reply_msg, msg_up, timers, counters)
2256 *
2257 * The return value is the disposition of the chunk.
2258 */
2259static sctp_disposition_t sctp_sf_do_5_2_6_stale(const struct sctp_endpoint *ep,
2260 const struct sctp_association *asoc,
2261 const sctp_subtype_t type,
2262 void *arg,
2263 sctp_cmd_seq_t *commands)
2264{
2265 struct sctp_chunk *chunk = arg;
2266 time_t stale;
2267 sctp_cookie_preserve_param_t bht;
2268 sctp_errhdr_t *err;
2269 struct sctp_chunk *reply;
2270 struct sctp_bind_addr *bp;
3f7a87d2 2271 int attempts = asoc->init_err_counter + 1;
1da177e4 2272
81845c21 2273 if (attempts > asoc->max_init_attempts) {
8de8c873
SS
2274 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
2275 SCTP_ERROR(ETIMEDOUT));
1da177e4 2276 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
dc251b2b 2277 SCTP_PERR(SCTP_ERROR_STALE_COOKIE));
1da177e4
LT
2278 return SCTP_DISPOSITION_DELETE_TCB;
2279 }
2280
2281 err = (sctp_errhdr_t *)(chunk->skb->data);
2282
2283 /* When calculating the time extension, an implementation
2284 * SHOULD use the RTT information measured based on the
2285 * previous COOKIE ECHO / ERROR exchange, and should add no
2286 * more than 1 second beyond the measured RTT, due to long
2287 * State Cookie lifetimes making the endpoint more subject to
2288 * a replay attack.
2289 * Measure of Staleness's unit is usec. (1/1000000 sec)
2290 * Suggested Cookie Life-span Increment's unit is msec.
2291 * (1/1000 sec)
2292 * In general, if you use the suggested cookie life, the value
2293 * found in the field of measure of staleness should be doubled
2294 * to give ample time to retransmit the new cookie and thus
2295 * yield a higher probability of success on the reattempt.
2296 */
34bcca28 2297 stale = ntohl(*(__be32 *)((u8 *)err + sizeof(sctp_errhdr_t)));
1da177e4
LT
2298 stale = (stale * 2) / 1000;
2299
2300 bht.param_hdr.type = SCTP_PARAM_COOKIE_PRESERVATIVE;
2301 bht.param_hdr.length = htons(sizeof(bht));
2302 bht.lifespan_increment = htonl(stale);
2303
2304 /* Build that new INIT chunk. */
2305 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
2306 reply = sctp_make_init(asoc, bp, GFP_ATOMIC, sizeof(bht));
2307 if (!reply)
2308 goto nomem;
2309
2310 sctp_addto_chunk(reply, sizeof(bht), &bht);
2311
2312 /* Clear peer's init_tag cached in assoc as we are sending a new INIT */
2313 sctp_add_cmd_sf(commands, SCTP_CMD_CLEAR_INIT_TAG, SCTP_NULL());
2314
2315 /* Stop pending T3-rtx and heartbeat timers */
2316 sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
2317 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
2318
2319 /* Delete non-primary peer ip addresses since we are transitioning
2320 * back to the COOKIE-WAIT state
2321 */
2322 sctp_add_cmd_sf(commands, SCTP_CMD_DEL_NON_PRIMARY, SCTP_NULL());
2323
d808ad9a
YH
2324 /* If we've sent any data bundled with COOKIE-ECHO we will need to
2325 * resend
1da177e4 2326 */
b6157d8e 2327 sctp_add_cmd_sf(commands, SCTP_CMD_T1_RETRAN,
1da177e4
LT
2328 SCTP_TRANSPORT(asoc->peer.primary_path));
2329
2330 /* Cast away the const modifier, as we want to just
2331 * rerun it through as a sideffect.
2332 */
3f7a87d2 2333 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_INC, SCTP_NULL());
1da177e4
LT
2334
2335 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2336 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
2337 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2338 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
2339 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
2340 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
2341
2342 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2343
2344 return SCTP_DISPOSITION_CONSUME;
2345
2346nomem:
2347 return SCTP_DISPOSITION_NOMEM;
2348}
2349
2350/*
2351 * Process an ABORT.
2352 *
2353 * Section: 9.1
2354 * After checking the Verification Tag, the receiving endpoint shall
2355 * remove the association from its record, and shall report the
2356 * termination to its upper layer.
2357 *
2358 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
2359 * B) Rules for packet carrying ABORT:
2360 *
2361 * - The endpoint shall always fill in the Verification Tag field of the
2362 * outbound packet with the destination endpoint's tag value if it
2363 * is known.
2364 *
2365 * - If the ABORT is sent in response to an OOTB packet, the endpoint
2366 * MUST follow the procedure described in Section 8.4.
2367 *
2368 * - The receiver MUST accept the packet if the Verification Tag
2369 * matches either its own tag, OR the tag of its peer. Otherwise, the
2370 * receiver MUST silently discard the packet and take no further
2371 * action.
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_1_abort(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;
1da177e4
LT
2388
2389 if (!sctp_vtag_verify_either(chunk, asoc))
2390 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2391
2392 /* Make sure that the ABORT chunk has a valid length.
2393 * Since this is an ABORT chunk, we have to discard it
2394 * because of the following text:
2395 * RFC 2960, Section 3.3.7
2396 * If an endpoint receives an ABORT with a format error or for an
2397 * association that doesn't exist, it MUST silently discard it.
25985edc 2398 * Because the length is "invalid", we can't really discard just
1da177e4
LT
2399 * as we do not know its true length. So, to be safe, discard the
2400 * packet.
2401 */
2402 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2403 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2404
75205f47
VY
2405 /* ADD-IP: Special case for ABORT chunks
2406 * F4) One special consideration is that ABORT Chunks arriving
2407 * destined to the IP address being deleted MUST be
2408 * ignored (see Section 5.3.1 for further details).
2409 */
2410 if (SCTP_ADDR_DEL ==
2411 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
2412 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
2413
2414 return __sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
2415}
2416
2417static sctp_disposition_t __sctp_sf_do_9_1_abort(const struct sctp_endpoint *ep,
2418 const struct sctp_association *asoc,
2419 const sctp_subtype_t type,
2420 void *arg,
2421 sctp_cmd_seq_t *commands)
2422{
2423 struct sctp_chunk *chunk = arg;
95c96174 2424 unsigned int len;
75205f47 2425 __be16 error = SCTP_ERROR_NO_ERROR;
b01a2407 2426 struct net *net;
75205f47 2427
1da177e4
LT
2428 /* See if we have an error cause code in the chunk. */
2429 len = ntohs(chunk->chunk_hdr->length);
96ca468b
SW
2430 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr)) {
2431
2432 sctp_errhdr_t *err;
2433 sctp_walk_errors(err, chunk->chunk_hdr);
2434 if ((void *)err != (void *)chunk->chunk_end)
2435 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2436
1da177e4 2437 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
96ca468b 2438 }
1da177e4 2439
8de8c873 2440 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNRESET));
d808ad9a 2441 /* ASSOC_FAILED will DELETE_TCB. */
5be291fe 2442 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, SCTP_PERR(error));
b01a2407
EB
2443 net = sock_net(ep->base.sk);
2444 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
2445 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
1da177e4
LT
2446
2447 return SCTP_DISPOSITION_ABORT;
2448}
2449
2450/*
2451 * Process an ABORT. (COOKIE-WAIT state)
2452 *
2453 * See sctp_sf_do_9_1_abort() above.
2454 */
2455sctp_disposition_t sctp_sf_cookie_wait_abort(const struct sctp_endpoint *ep,
2456 const struct sctp_association *asoc,
2457 const sctp_subtype_t type,
2458 void *arg,
2459 sctp_cmd_seq_t *commands)
2460{
2461 struct sctp_chunk *chunk = arg;
95c96174 2462 unsigned int len;
f94c0198 2463 __be16 error = SCTP_ERROR_NO_ERROR;
1da177e4
LT
2464
2465 if (!sctp_vtag_verify_either(chunk, asoc))
2466 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2467
2468 /* Make sure that the ABORT chunk has a valid length.
2469 * Since this is an ABORT chunk, we have to discard it
2470 * because of the following text:
2471 * RFC 2960, Section 3.3.7
2472 * If an endpoint receives an ABORT with a format error or for an
2473 * association that doesn't exist, it MUST silently discard it.
25985edc 2474 * Because the length is "invalid", we can't really discard just
1da177e4
LT
2475 * as we do not know its true length. So, to be safe, discard the
2476 * packet.
2477 */
2478 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2479 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2480
2481 /* See if we have an error cause code in the chunk. */
2482 len = ntohs(chunk->chunk_hdr->length);
2483 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
2484 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2485
8de8c873
SS
2486 return sctp_stop_t1_and_abort(commands, error, ECONNREFUSED, asoc,
2487 chunk->transport);
1da177e4
LT
2488}
2489
2490/*
2491 * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state)
2492 */
2493sctp_disposition_t sctp_sf_cookie_wait_icmp_abort(const struct sctp_endpoint *ep,
2494 const struct sctp_association *asoc,
2495 const sctp_subtype_t type,
2496 void *arg,
2497 sctp_cmd_seq_t *commands)
2498{
8de8c873
SS
2499 return sctp_stop_t1_and_abort(commands, SCTP_ERROR_NO_ERROR,
2500 ENOPROTOOPT, asoc,
3f7a87d2 2501 (struct sctp_transport *)arg);
1da177e4
LT
2502}
2503
2504/*
2505 * Process an ABORT. (COOKIE-ECHOED state)
2506 */
2507sctp_disposition_t sctp_sf_cookie_echoed_abort(const struct sctp_endpoint *ep,
2508 const struct sctp_association *asoc,
2509 const sctp_subtype_t type,
2510 void *arg,
2511 sctp_cmd_seq_t *commands)
2512{
2513 /* There is a single T1 timer, so we should be able to use
2514 * common function with the COOKIE-WAIT state.
2515 */
2516 return sctp_sf_cookie_wait_abort(ep, asoc, type, arg, commands);
2517}
2518
2519/*
2520 * Stop T1 timer and abort association with "INIT failed".
2521 *
2522 * This is common code called by several sctp_sf_*_abort() functions above.
2523 */
52c1da39 2524static sctp_disposition_t sctp_stop_t1_and_abort(sctp_cmd_seq_t *commands,
f94c0198 2525 __be16 error, int sk_err,
3f7a87d2
FF
2526 const struct sctp_association *asoc,
2527 struct sctp_transport *transport)
1da177e4 2528{
3f7a87d2 2529 SCTP_DEBUG_PRINTK("ABORT received (INIT).\n");
1da177e4
LT
2530 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2531 SCTP_STATE(SCTP_STATE_CLOSED));
b01a2407 2532 SCTP_INC_STATS(sock_net(asoc->base.sk), SCTP_MIB_ABORTEDS);
1da177e4
LT
2533 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2534 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
8de8c873 2535 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(sk_err));
1da177e4
LT
2536 /* CMD_INIT_FAILED will DELETE_TCB. */
2537 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
dc251b2b 2538 SCTP_PERR(error));
3f7a87d2 2539 return SCTP_DISPOSITION_ABORT;
1da177e4
LT
2540}
2541
2542/*
2543 * sctp_sf_do_9_2_shut
2544 *
2545 * Section: 9.2
2546 * Upon the reception of the SHUTDOWN, the peer endpoint shall
2547 * - enter the SHUTDOWN-RECEIVED state,
2548 *
2549 * - stop accepting new data from its SCTP user
2550 *
2551 * - verify, by checking the Cumulative TSN Ack field of the chunk,
2552 * that all its outstanding DATA chunks have been received by the
2553 * SHUTDOWN sender.
2554 *
2555 * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT
2556 * send a SHUTDOWN in response to a ULP request. And should discard
2557 * subsequent SHUTDOWN chunks.
2558 *
2559 * If there are still outstanding DATA chunks left, the SHUTDOWN
2560 * receiver shall continue to follow normal data transmission
2561 * procedures defined in Section 6 until all outstanding DATA chunks
2562 * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept
2563 * new data from its SCTP user.
2564 *
2565 * Verification Tag: 8.5 Verification Tag [Normal verification]
2566 *
2567 * Inputs
2568 * (endpoint, asoc, chunk)
2569 *
2570 * Outputs
2571 * (asoc, reply_msg, msg_up, timers, counters)
2572 *
2573 * The return value is the disposition of the chunk.
2574 */
2575sctp_disposition_t sctp_sf_do_9_2_shutdown(const struct sctp_endpoint *ep,
2576 const struct sctp_association *asoc,
2577 const sctp_subtype_t type,
2578 void *arg,
2579 sctp_cmd_seq_t *commands)
2580{
2581 struct sctp_chunk *chunk = arg;
2582 sctp_shutdownhdr_t *sdh;
2583 sctp_disposition_t disposition;
2584 struct sctp_ulpevent *ev;
df10eec4 2585 __u32 ctsn;
1da177e4
LT
2586
2587 if (!sctp_vtag_verify(chunk, asoc))
2588 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2589
2590 /* Make sure that the SHUTDOWN chunk has a valid length. */
2591 if (!sctp_chunk_length_valid(chunk,
2592 sizeof(struct sctp_shutdown_chunk_t)))
2593 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2594 commands);
2595
2596 /* Convert the elaborate header. */
2597 sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
2598 skb_pull(chunk->skb, sizeof(sctp_shutdownhdr_t));
2599 chunk->subh.shutdown_hdr = sdh;
df10eec4
WY
2600 ctsn = ntohl(sdh->cum_tsn_ack);
2601
a2f36eec
WY
2602 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
2603 SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn);
2604 SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc->ctsn_ack_point);
2605 return SCTP_DISPOSITION_DISCARD;
2606 }
2607
df10eec4
WY
2608 /* If Cumulative TSN Ack beyond the max tsn currently
2609 * send, terminating the association and respond to the
2610 * sender with an ABORT.
2611 */
2612 if (!TSN_lt(ctsn, asoc->next_tsn))
2613 return sctp_sf_violation_ctsn(ep, asoc, type, arg, commands);
1da177e4 2614
eb0e0076
SS
2615 /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT
2616 * When a peer sends a SHUTDOWN, SCTP delivers this notification to
2617 * inform the application that it should cease sending data.
2618 */
2619 ev = sctp_ulpevent_make_shutdown_event(asoc, 0, GFP_ATOMIC);
2620 if (!ev) {
2621 disposition = SCTP_DISPOSITION_NOMEM;
d808ad9a 2622 goto out;
eb0e0076
SS
2623 }
2624 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
2625
1da177e4
LT
2626 /* Upon the reception of the SHUTDOWN, the peer endpoint shall
2627 * - enter the SHUTDOWN-RECEIVED state,
2628 * - stop accepting new data from its SCTP user
2629 *
2630 * [This is implicit in the new state.]
2631 */
2632 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2633 SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED));
2634 disposition = SCTP_DISPOSITION_CONSUME;
2635
2636 if (sctp_outq_is_empty(&asoc->outqueue)) {
2637 disposition = sctp_sf_do_9_2_shutdown_ack(ep, asoc, type,
2638 arg, commands);
2639 }
2640
2641 if (SCTP_DISPOSITION_NOMEM == disposition)
2642 goto out;
2643
2644 /* - verify, by checking the Cumulative TSN Ack field of the
2645 * chunk, that all its outstanding DATA chunks have been
2646 * received by the SHUTDOWN sender.
2647 */
2648 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
2178eda8 2649 SCTP_BE32(chunk->subh.shutdown_hdr->cum_tsn_ack));
1da177e4 2650
1da177e4
LT
2651out:
2652 return disposition;
2653}
2654
2e3f92da
WY
2655/*
2656 * sctp_sf_do_9_2_shut_ctsn
2657 *
2658 * Once an endpoint has reached the SHUTDOWN-RECEIVED state,
2659 * it MUST NOT send a SHUTDOWN in response to a ULP request.
2660 * The Cumulative TSN Ack of the received SHUTDOWN chunk
2661 * MUST be processed.
2662 */
2663sctp_disposition_t sctp_sf_do_9_2_shut_ctsn(const struct sctp_endpoint *ep,
2664 const struct sctp_association *asoc,
2665 const sctp_subtype_t type,
2666 void *arg,
2667 sctp_cmd_seq_t *commands)
2668{
2669 struct sctp_chunk *chunk = arg;
2670 sctp_shutdownhdr_t *sdh;
a2f36eec 2671 __u32 ctsn;
2e3f92da
WY
2672
2673 if (!sctp_vtag_verify(chunk, asoc))
2674 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2675
2676 /* Make sure that the SHUTDOWN chunk has a valid length. */
2677 if (!sctp_chunk_length_valid(chunk,
2678 sizeof(struct sctp_shutdown_chunk_t)))
2679 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2680 commands);
2681
2682 sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
a2f36eec
WY
2683 ctsn = ntohl(sdh->cum_tsn_ack);
2684
2685 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
2686 SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn);
2687 SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc->ctsn_ack_point);
2688 return SCTP_DISPOSITION_DISCARD;
2689 }
2e3f92da
WY
2690
2691 /* If Cumulative TSN Ack beyond the max tsn currently
2692 * send, terminating the association and respond to the
2693 * sender with an ABORT.
2694 */
a2f36eec 2695 if (!TSN_lt(ctsn, asoc->next_tsn))
2e3f92da
WY
2696 return sctp_sf_violation_ctsn(ep, asoc, type, arg, commands);
2697
2698 /* verify, by checking the Cumulative TSN Ack field of the
2699 * chunk, that all its outstanding DATA chunks have been
2700 * received by the SHUTDOWN sender.
2701 */
2702 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
2703 SCTP_BE32(sdh->cum_tsn_ack));
2704
2705 return SCTP_DISPOSITION_CONSUME;
2706}
2707
1da177e4
LT
2708/* RFC 2960 9.2
2709 * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk
2710 * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination
2711 * transport addresses (either in the IP addresses or in the INIT chunk)
2712 * that belong to this association, it should discard the INIT chunk and
2713 * retransmit the SHUTDOWN ACK chunk.
2714 */
2715sctp_disposition_t sctp_sf_do_9_2_reshutack(const struct sctp_endpoint *ep,
2716 const struct sctp_association *asoc,
2717 const sctp_subtype_t type,
2718 void *arg,
2719 sctp_cmd_seq_t *commands)
2720{
2721 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
2722 struct sctp_chunk *reply;
2723
ece25dfa
VY
2724 /* Make sure that the chunk has a valid length */
2725 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
2726 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2727 commands);
2728
1da177e4
LT
2729 /* Since we are not going to really process this INIT, there
2730 * is no point in verifying chunk boundries. Just generate
2731 * the SHUTDOWN ACK.
2732 */
2733 reply = sctp_make_shutdown_ack(asoc, chunk);
2734 if (NULL == reply)
2735 goto nomem;
2736
2737 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
2738 * the T2-SHUTDOWN timer.
2739 */
2740 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
2741
2742 /* and restart the T2-shutdown timer. */
2743 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2744 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2745
2746 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2747
2748 return SCTP_DISPOSITION_CONSUME;
2749nomem:
2750 return SCTP_DISPOSITION_NOMEM;
2751}
2752
2753/*
2754 * sctp_sf_do_ecn_cwr
2755 *
2756 * Section: Appendix A: Explicit Congestion Notification
2757 *
2758 * CWR:
2759 *
2760 * RFC 2481 details a specific bit for a sender to send in the header of
2761 * its next outbound TCP segment to indicate to its peer that it has
2762 * reduced its congestion window. This is termed the CWR bit. For
2763 * SCTP the same indication is made by including the CWR chunk.
2764 * This chunk contains one data element, i.e. the TSN number that
2765 * was sent in the ECNE chunk. This element represents the lowest
2766 * TSN number in the datagram that was originally marked with the
2767 * CE bit.
2768 *
2769 * Verification Tag: 8.5 Verification Tag [Normal verification]
2770 * Inputs
2771 * (endpoint, asoc, chunk)
2772 *
2773 * Outputs
2774 * (asoc, reply_msg, msg_up, timers, counters)
2775 *
2776 * The return value is the disposition of the chunk.
2777 */
2778sctp_disposition_t sctp_sf_do_ecn_cwr(const struct sctp_endpoint *ep,
2779 const struct sctp_association *asoc,
2780 const sctp_subtype_t type,
2781 void *arg,
2782 sctp_cmd_seq_t *commands)
2783{
2784 sctp_cwrhdr_t *cwr;
2785 struct sctp_chunk *chunk = arg;
34bcca28 2786 u32 lowest_tsn;
1da177e4
LT
2787
2788 if (!sctp_vtag_verify(chunk, asoc))
2789 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2790
2791 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2792 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2793 commands);
d808ad9a 2794
1da177e4
LT
2795 cwr = (sctp_cwrhdr_t *) chunk->skb->data;
2796 skb_pull(chunk->skb, sizeof(sctp_cwrhdr_t));
2797
34bcca28 2798 lowest_tsn = ntohl(cwr->lowest_tsn);
1da177e4
LT
2799
2800 /* Does this CWR ack the last sent congestion notification? */
34bcca28 2801 if (TSN_lte(asoc->last_ecne_tsn, lowest_tsn)) {
1da177e4
LT
2802 /* Stop sending ECNE. */
2803 sctp_add_cmd_sf(commands,
2804 SCTP_CMD_ECN_CWR,
34bcca28 2805 SCTP_U32(lowest_tsn));
1da177e4
LT
2806 }
2807 return SCTP_DISPOSITION_CONSUME;
2808}
2809
2810/*
2811 * sctp_sf_do_ecne
2812 *
2813 * Section: Appendix A: Explicit Congestion Notification
2814 *
2815 * ECN-Echo
2816 *
2817 * RFC 2481 details a specific bit for a receiver to send back in its
2818 * TCP acknowledgements to notify the sender of the Congestion
2819 * Experienced (CE) bit having arrived from the network. For SCTP this
2820 * same indication is made by including the ECNE chunk. This chunk
2821 * contains one data element, i.e. the lowest TSN associated with the IP
2822 * datagram marked with the CE bit.....
2823 *
2824 * Verification Tag: 8.5 Verification Tag [Normal verification]
2825 * Inputs
2826 * (endpoint, asoc, chunk)
2827 *
2828 * Outputs
2829 * (asoc, reply_msg, msg_up, timers, counters)
2830 *
2831 * The return value is the disposition of the chunk.
2832 */
2833sctp_disposition_t sctp_sf_do_ecne(const struct sctp_endpoint *ep,
2834 const struct sctp_association *asoc,
2835 const sctp_subtype_t type,
2836 void *arg,
2837 sctp_cmd_seq_t *commands)
2838{
2839 sctp_ecnehdr_t *ecne;
2840 struct sctp_chunk *chunk = arg;
2841
2842 if (!sctp_vtag_verify(chunk, asoc))
2843 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2844
2845 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2846 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2847 commands);
2848
2849 ecne = (sctp_ecnehdr_t *) chunk->skb->data;
2850 skb_pull(chunk->skb, sizeof(sctp_ecnehdr_t));
2851
2852 /* If this is a newer ECNE than the last CWR packet we sent out */
2853 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_ECNE,
2854 SCTP_U32(ntohl(ecne->lowest_tsn)));
2855
2856 return SCTP_DISPOSITION_CONSUME;
2857}
2858
2859/*
2860 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
2861 *
2862 * The SCTP endpoint MUST always acknowledge the reception of each valid
2863 * DATA chunk.
2864 *
2865 * The guidelines on delayed acknowledgement algorithm specified in
2866 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
2867 * acknowledgement SHOULD be generated for at least every second packet
2868 * (not every second DATA chunk) received, and SHOULD be generated within
2869 * 200 ms of the arrival of any unacknowledged DATA chunk. In some
2870 * situations it may be beneficial for an SCTP transmitter to be more
2871 * conservative than the algorithms detailed in this document allow.
2872 * However, an SCTP transmitter MUST NOT be more aggressive than the
2873 * following algorithms allow.
2874 *
2875 * A SCTP receiver MUST NOT generate more than one SACK for every
2876 * incoming packet, other than to update the offered window as the
2877 * receiving application consumes new data.
2878 *
2879 * Verification Tag: 8.5 Verification Tag [Normal verification]
2880 *
2881 * Inputs
2882 * (endpoint, asoc, chunk)
2883 *
2884 * Outputs
2885 * (asoc, reply_msg, msg_up, timers, counters)
2886 *
2887 * The return value is the disposition of the chunk.
2888 */
2889sctp_disposition_t sctp_sf_eat_data_6_2(const struct sctp_endpoint *ep,
2890 const struct sctp_association *asoc,
2891 const sctp_subtype_t type,
2892 void *arg,
2893 sctp_cmd_seq_t *commands)
2894{
2895 struct sctp_chunk *chunk = arg;
6dc7694f 2896 sctp_arg_t force = SCTP_NOFORCE();
1da177e4
LT
2897 int error;
2898
2899 if (!sctp_vtag_verify(chunk, asoc)) {
2900 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
2901 SCTP_NULL());
2902 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
d808ad9a 2903 }
1da177e4
LT
2904
2905 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
2906 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2907 commands);
2908
2909 error = sctp_eat_data(asoc, chunk, commands );
2910 switch (error) {
2911 case SCTP_IERROR_NO_ERROR:
2912 break;
2913 case SCTP_IERROR_HIGH_TSN:
2914 case SCTP_IERROR_BAD_STREAM:
b01a2407 2915 SCTP_INC_STATS(sock_net(asoc->base.sk), SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
1da177e4
LT
2916 goto discard_noforce;
2917 case SCTP_IERROR_DUP_TSN:
2918 case SCTP_IERROR_IGNORE_TSN:
b01a2407 2919 SCTP_INC_STATS(sock_net(asoc->base.sk), SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
1da177e4
LT
2920 goto discard_force;
2921 case SCTP_IERROR_NO_DATA:
2922 goto consume;
f1751c57
VY
2923 case SCTP_IERROR_PROTO_VIOLATION:
2924 return sctp_sf_abort_violation(ep, asoc, chunk, commands,
2925 (u8 *)chunk->subh.data_hdr, sizeof(sctp_datahdr_t));
1da177e4
LT
2926 default:
2927 BUG();
2928 }
2929
6dc7694f
WY
2930 if (chunk->chunk_hdr->flags & SCTP_DATA_SACK_IMM)
2931 force = SCTP_FORCE();
2932
1da177e4
LT
2933 if (asoc->autoclose) {
2934 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2935 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
2936 }
2937
2938 /* If this is the last chunk in a packet, we need to count it
2939 * toward sack generation. Note that we need to SACK every
2940 * OTHER packet containing data chunks, EVEN IF WE DISCARD
2941 * THEM. We elect to NOT generate SACK's if the chunk fails
2942 * the verification tag test.
2943 *
2944 * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2945 *
2946 * The SCTP endpoint MUST always acknowledge the reception of
2947 * each valid DATA chunk.
2948 *
2949 * The guidelines on delayed acknowledgement algorithm
2950 * specified in Section 4.2 of [RFC2581] SHOULD be followed.
2951 * Specifically, an acknowledgement SHOULD be generated for at
2952 * least every second packet (not every second DATA chunk)
2953 * received, and SHOULD be generated within 200 ms of the
2954 * arrival of any unacknowledged DATA chunk. In some
2955 * situations it may be beneficial for an SCTP transmitter to
2956 * be more conservative than the algorithms detailed in this
2957 * document allow. However, an SCTP transmitter MUST NOT be
2958 * more aggressive than the following algorithms allow.
2959 */
52ccb8e9 2960 if (chunk->end_of_packet)
6dc7694f 2961 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force);
1da177e4 2962
1da177e4
LT
2963 return SCTP_DISPOSITION_CONSUME;
2964
2965discard_force:
2966 /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2967 *
2968 * When a packet arrives with duplicate DATA chunk(s) and with
2969 * no new DATA chunk(s), the endpoint MUST immediately send a
2970 * SACK with no delay. If a packet arrives with duplicate
2971 * DATA chunk(s) bundled with new DATA chunks, the endpoint
2972 * MAY immediately send a SACK. Normally receipt of duplicate
2973 * DATA chunks will occur when the original SACK chunk was lost
2974 * and the peer's RTO has expired. The duplicate TSN number(s)
2975 * SHOULD be reported in the SACK as duplicate.
2976 */
2977 /* In our case, we split the MAY SACK advice up whether or not
2978 * the last chunk is a duplicate.'
2979 */
2980 if (chunk->end_of_packet)
2981 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
2982 return SCTP_DISPOSITION_DISCARD;
2983
2984discard_noforce:
52ccb8e9 2985 if (chunk->end_of_packet)
6dc7694f 2986 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force);
1da177e4 2987
1da177e4
LT
2988 return SCTP_DISPOSITION_DISCARD;
2989consume:
2990 return SCTP_DISPOSITION_CONSUME;
d808ad9a 2991
1da177e4
LT
2992}
2993
2994/*
2995 * sctp_sf_eat_data_fast_4_4
2996 *
2997 * Section: 4 (4)
2998 * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received
2999 * DATA chunks without delay.
3000 *
3001 * Verification Tag: 8.5 Verification Tag [Normal verification]
3002 * Inputs
3003 * (endpoint, asoc, chunk)
3004 *
3005 * Outputs
3006 * (asoc, reply_msg, msg_up, timers, counters)
3007 *
3008 * The return value is the disposition of the chunk.
3009 */
3010sctp_disposition_t sctp_sf_eat_data_fast_4_4(const struct sctp_endpoint *ep,
3011 const struct sctp_association *asoc,
3012 const sctp_subtype_t type,
3013 void *arg,
3014 sctp_cmd_seq_t *commands)
3015{
3016 struct sctp_chunk *chunk = arg;
3017 int error;
3018
3019 if (!sctp_vtag_verify(chunk, asoc)) {
3020 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3021 SCTP_NULL());
3022 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3023 }
3024
3025 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
3026 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3027 commands);
3028
3029 error = sctp_eat_data(asoc, chunk, commands );
3030 switch (error) {
3031 case SCTP_IERROR_NO_ERROR:
3032 case SCTP_IERROR_HIGH_TSN:
3033 case SCTP_IERROR_DUP_TSN:
3034 case SCTP_IERROR_IGNORE_TSN:
3035 case SCTP_IERROR_BAD_STREAM:
3036 break;
3037 case SCTP_IERROR_NO_DATA:
3038 goto consume;
f1751c57
VY
3039 case SCTP_IERROR_PROTO_VIOLATION:
3040 return sctp_sf_abort_violation(ep, asoc, chunk, commands,
3041 (u8 *)chunk->subh.data_hdr, sizeof(sctp_datahdr_t));
1da177e4
LT
3042 default:
3043 BUG();
3044 }
3045
3046 /* Go a head and force a SACK, since we are shutting down. */
3047
3048 /* Implementor's Guide.
3049 *
3050 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3051 * respond to each received packet containing one or more DATA chunk(s)
3052 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3053 */
3054 if (chunk->end_of_packet) {
3055 /* We must delay the chunk creation since the cumulative
3056 * TSN has not been updated yet.
3057 */
3058 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
3059 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3060 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3061 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3062 }
3063
3064consume:
3065 return SCTP_DISPOSITION_CONSUME;
3066}
3067
3068/*
3069 * Section: 6.2 Processing a Received SACK
3070 * D) Any time a SACK arrives, the endpoint performs the following:
3071 *
3072 * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point,
3073 * then drop the SACK. Since Cumulative TSN Ack is monotonically
3074 * increasing, a SACK whose Cumulative TSN Ack is less than the
3075 * Cumulative TSN Ack Point indicates an out-of-order SACK.
3076 *
3077 * ii) Set rwnd equal to the newly received a_rwnd minus the number
3078 * of bytes still outstanding after processing the Cumulative TSN Ack
3079 * and the Gap Ack Blocks.
3080 *
3081 * iii) If the SACK is missing a TSN that was previously
3082 * acknowledged via a Gap Ack Block (e.g., the data receiver
3083 * reneged on the data), then mark the corresponding DATA chunk
3084 * as available for retransmit: Mark it as missing for fast
3085 * retransmit as described in Section 7.2.4 and if no retransmit
3086 * timer is running for the destination address to which the DATA
3087 * chunk was originally transmitted, then T3-rtx is started for
3088 * that destination address.
3089 *
3090 * Verification Tag: 8.5 Verification Tag [Normal verification]
3091 *
3092 * Inputs
3093 * (endpoint, asoc, chunk)
3094 *
3095 * Outputs
3096 * (asoc, reply_msg, msg_up, timers, counters)
3097 *
3098 * The return value is the disposition of the chunk.
3099 */
3100sctp_disposition_t sctp_sf_eat_sack_6_2(const struct sctp_endpoint *ep,
3101 const struct sctp_association *asoc,
3102 const sctp_subtype_t type,
3103 void *arg,
3104 sctp_cmd_seq_t *commands)
3105{
3106 struct sctp_chunk *chunk = arg;
3107 sctp_sackhdr_t *sackh;
3108 __u32 ctsn;
3109
3110 if (!sctp_vtag_verify(chunk, asoc))
3111 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3112
3113 /* Make sure that the SACK chunk has a valid length. */
3114 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_sack_chunk_t)))
3115 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3116 commands);
3117
3118 /* Pull the SACK chunk from the data buffer */
3119 sackh = sctp_sm_pull_sack(chunk);
3120 /* Was this a bogus SACK? */
3121 if (!sackh)
3122 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3123 chunk->subh.sack_hdr = sackh;
3124 ctsn = ntohl(sackh->cum_tsn_ack);
3125
3126 /* i) If Cumulative TSN Ack is less than the Cumulative TSN
3127 * Ack Point, then drop the SACK. Since Cumulative TSN
3128 * Ack is monotonically increasing, a SACK whose
3129 * Cumulative TSN Ack is less than the Cumulative TSN Ack
3130 * Point indicates an out-of-order SACK.
3131 */
3132 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
3133 SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn);
3134 SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc->ctsn_ack_point);
3135 return SCTP_DISPOSITION_DISCARD;
3136 }
3137
aecedeab
WY
3138 /* If Cumulative TSN Ack beyond the max tsn currently
3139 * send, terminating the association and respond to the
3140 * sender with an ABORT.
3141 */
3142 if (!TSN_lt(ctsn, asoc->next_tsn))
3143 return sctp_sf_violation_ctsn(ep, asoc, type, arg, commands);
3144
1da177e4
LT
3145 /* Return this SACK for further processing. */
3146 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_SACKH(sackh));
3147
3148 /* Note: We do the rest of the work on the PROCESS_SACK
3149 * sideeffect.
3150 */
3151 return SCTP_DISPOSITION_CONSUME;
3152}
3153
3154/*
3155 * Generate an ABORT in response to a packet.
3156 *
047a2428 3157 * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41
1da177e4 3158 *
047a2428
JF
3159 * 8) The receiver should respond to the sender of the OOTB packet with
3160 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3161 * MUST fill in the Verification Tag field of the outbound packet
3162 * with the value found in the Verification Tag field of the OOTB
3163 * packet and set the T-bit in the Chunk Flags to indicate that the
3164 * Verification Tag is reflected. After sending this ABORT, the
3165 * receiver of the OOTB packet shall discard the OOTB packet and take
3166 * no further action.
1da177e4
LT
3167 *
3168 * Verification Tag:
3169 *
3170 * The return value is the disposition of the chunk.
3171*/
ece25dfa 3172static sctp_disposition_t sctp_sf_tabort_8_4_8(const struct sctp_endpoint *ep,
1da177e4
LT
3173 const struct sctp_association *asoc,
3174 const sctp_subtype_t type,
3175 void *arg,
3176 sctp_cmd_seq_t *commands)
3177{
3178 struct sctp_packet *packet = NULL;
3179 struct sctp_chunk *chunk = arg;
3180 struct sctp_chunk *abort;
2ce95503 3181 struct net *net;
1da177e4 3182
2ce95503
EB
3183 net = sock_net(ep->base.sk);
3184 packet = sctp_ootb_pkt_new(net, asoc, chunk);
1da177e4
LT
3185
3186 if (packet) {
3187 /* Make an ABORT. The T bit will be set if the asoc
3188 * is NULL.
3189 */
d808ad9a 3190 abort = sctp_make_abort(asoc, chunk, 0);
1da177e4
LT
3191 if (!abort) {
3192 sctp_ootb_pkt_free(packet);
3193 return SCTP_DISPOSITION_NOMEM;
3194 }
3195
047a2428
JF
3196 /* Reflect vtag if T-Bit is set */
3197 if (sctp_test_T_bit(abort))
3198 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3199
1da177e4
LT
3200 /* Set the skb to the belonging sock for accounting. */
3201 abort->skb->sk = ep->base.sk;
3202
3203 sctp_packet_append_chunk(packet, abort);
3204
3205 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3206 SCTP_PACKET(packet));
3207
b01a2407 3208 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
1da177e4 3209
d3f25968 3210 sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1da177e4
LT
3211 return SCTP_DISPOSITION_CONSUME;
3212 }
3213
3214 return SCTP_DISPOSITION_NOMEM;
3215}
3216
3217/*
3218 * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR
3219 * event as ULP notification for each cause included in the chunk.
3220 *
3221 * API 5.3.1.3 - SCTP_REMOTE_ERROR
3222 *
3223 * The return value is the disposition of the chunk.
3224*/
3225sctp_disposition_t sctp_sf_operr_notify(const struct sctp_endpoint *ep,
3226 const struct sctp_association *asoc,
3227 const sctp_subtype_t type,
3228 void *arg,
3229 sctp_cmd_seq_t *commands)
3230{
3231 struct sctp_chunk *chunk = arg;
8a00be1c 3232 sctp_errhdr_t *err;
1da177e4
LT
3233
3234 if (!sctp_vtag_verify(chunk, asoc))
3235 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3236
3237 /* Make sure that the ERROR chunk has a valid length. */
3238 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
3239 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3240 commands);
8a00be1c
SW
3241 sctp_walk_errors(err, chunk->chunk_hdr);
3242 if ((void *)err != (void *)chunk->chunk_end)
3243 return sctp_sf_violation_paramlen(ep, asoc, type, arg,
3244 (void *)err, commands);
1da177e4 3245
3df26787
WY
3246 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_OPERR,
3247 SCTP_CHUNK(chunk));
1da177e4 3248
1da177e4 3249 return SCTP_DISPOSITION_CONSUME;
1da177e4
LT
3250}
3251
3252/*
3253 * Process an inbound SHUTDOWN ACK.
3254 *
3255 * From Section 9.2:
3256 * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3257 * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its
3258 * peer, and remove all record of the association.
3259 *
3260 * The return value is the disposition.
3261 */
3262sctp_disposition_t sctp_sf_do_9_2_final(const struct sctp_endpoint *ep,
3263 const struct sctp_association *asoc,
3264 const sctp_subtype_t type,
3265 void *arg,
3266 sctp_cmd_seq_t *commands)
3267{
3268 struct sctp_chunk *chunk = arg;
3269 struct sctp_chunk *reply;
3270 struct sctp_ulpevent *ev;
b01a2407 3271 struct net *net;
1da177e4
LT
3272
3273 if (!sctp_vtag_verify(chunk, asoc))
3274 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3275
3276 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3277 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3278 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3279 commands);
1da177e4
LT
3280 /* 10.2 H) SHUTDOWN COMPLETE notification
3281 *
3282 * When SCTP completes the shutdown procedures (section 9.2) this
3283 * notification is passed to the upper layer.
3284 */
3285 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
a5a35e76 3286 0, 0, 0, NULL, GFP_ATOMIC);
1da177e4
LT
3287 if (!ev)
3288 goto nomem;
3289
df7deeb5
VY
3290 /* ...send a SHUTDOWN COMPLETE chunk to its peer, */
3291 reply = sctp_make_shutdown_complete(asoc, chunk);
3292 if (!reply)
3293 goto nomem_chunk;
3294
3295 /* Do all the commands now (after allocation), so that we
3296 * have consistent state if memory allocation failes
3297 */
1da177e4
LT
3298 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
3299
3300 /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3301 * stop the T2-shutdown timer,
3302 */
3303 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3304 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3305
3306 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3307 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
3308
1da177e4
LT
3309 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3310 SCTP_STATE(SCTP_STATE_CLOSED));
b01a2407
EB
3311 net = sock_net(asoc->base.sk);
3312 SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS);
3313 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
1da177e4
LT
3314 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
3315
3316 /* ...and remove all record of the association. */
3317 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
3318 return SCTP_DISPOSITION_DELETE_TCB;
3319
df7deeb5
VY
3320nomem_chunk:
3321 sctp_ulpevent_free(ev);
1da177e4
LT
3322nomem:
3323 return SCTP_DISPOSITION_NOMEM;
3324}
3325
3326/*
047a2428
JF
3327 * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41.
3328 *
1da177e4
LT
3329 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3330 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3331 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3332 * packet must fill in the Verification Tag field of the outbound
3333 * packet with the Verification Tag received in the SHUTDOWN ACK and
047a2428
JF
3334 * set the T-bit in the Chunk Flags to indicate that the Verification
3335 * Tag is reflected.
1da177e4
LT
3336 *
3337 * 8) The receiver should respond to the sender of the OOTB packet with
3338 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3339 * MUST fill in the Verification Tag field of the outbound packet
3340 * with the value found in the Verification Tag field of the OOTB
047a2428
JF
3341 * packet and set the T-bit in the Chunk Flags to indicate that the
3342 * Verification Tag is reflected. After sending this ABORT, the
3343 * receiver of the OOTB packet shall discard the OOTB packet and take
3344 * no further action.
1da177e4
LT
3345 */
3346sctp_disposition_t sctp_sf_ootb(const struct sctp_endpoint *ep,
3347 const struct sctp_association *asoc,
3348 const sctp_subtype_t type,
3349 void *arg,
3350 sctp_cmd_seq_t *commands)
3351{
3352 struct sctp_chunk *chunk = arg;
3353 struct sk_buff *skb = chunk->skb;
3354 sctp_chunkhdr_t *ch;
85c5ed4e 3355 sctp_errhdr_t *err;
1da177e4
LT
3356 __u8 *ch_end;
3357 int ootb_shut_ack = 0;
85c5ed4e 3358 int ootb_cookie_ack = 0;
b01a2407 3359 struct net *net;
1da177e4 3360
b01a2407
EB
3361 net = sock_net(asoc->base.sk);
3362 SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
1da177e4
LT
3363
3364 ch = (sctp_chunkhdr_t *) chunk->chunk_hdr;
3365 do {
ece25dfa 3366 /* Report violation if the chunk is less then minimal */
1da177e4 3367 if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t))
ece25dfa
VY
3368 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3369 commands);
1da177e4 3370
ece25dfa
VY
3371 /* Now that we know we at least have a chunk header,
3372 * do things that are type appropriate.
3373 */
1da177e4
LT
3374 if (SCTP_CID_SHUTDOWN_ACK == ch->type)
3375 ootb_shut_ack = 1;
3376
3377 /* RFC 2960, Section 3.3.7
3378 * Moreover, under any circumstances, an endpoint that
3379 * receives an ABORT MUST NOT respond to that ABORT by
3380 * sending an ABORT of its own.
3381 */
3382 if (SCTP_CID_ABORT == ch->type)
3383 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
d808ad9a 3384
85c5ed4e
SW
3385 /* RFC 8.4, 7) If the packet contains a "Stale cookie" ERROR
3386 * or a COOKIE ACK the SCTP Packet should be silently
3387 * discarded.
3388 */
3389
3390 if (SCTP_CID_COOKIE_ACK == ch->type)
3391 ootb_cookie_ack = 1;
3392
3393 if (SCTP_CID_ERROR == ch->type) {
3394 sctp_walk_errors(err, ch) {
3395 if (SCTP_ERROR_STALE_COOKIE == err->cause) {
3396 ootb_cookie_ack = 1;
3397 break;
3398 }
3399 }
3400 }
3401
ece25dfa
VY
3402 /* Report violation if chunk len overflows */
3403 ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
3404 if (ch_end > skb_tail_pointer(skb))
3405 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3406 commands);
3407
1da177e4 3408 ch = (sctp_chunkhdr_t *) ch_end;
27a884dc 3409 } while (ch_end < skb_tail_pointer(skb));
1da177e4
LT
3410
3411 if (ootb_shut_ack)
d3f25968 3412 return sctp_sf_shut_8_4_5(ep, asoc, type, arg, commands);
85c5ed4e
SW
3413 else if (ootb_cookie_ack)
3414 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1da177e4 3415 else
d3f25968 3416 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
1da177e4
LT
3417}
3418
3419/*
3420 * Handle an "Out of the blue" SHUTDOWN ACK.
3421 *
047a2428
JF
3422 * Section: 8.4 5, sctpimpguide 2.41.
3423 *
1da177e4 3424 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
047a2428
JF
3425 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3426 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3427 * packet must fill in the Verification Tag field of the outbound
3428 * packet with the Verification Tag received in the SHUTDOWN ACK and
3429 * set the T-bit in the Chunk Flags to indicate that the Verification
3430 * Tag is reflected.
1da177e4
LT
3431 *
3432 * Inputs
3433 * (endpoint, asoc, type, arg, commands)
3434 *
3435 * Outputs
3436 * (sctp_disposition_t)
3437 *
3438 * The return value is the disposition of the chunk.
3439 */
3440static sctp_disposition_t sctp_sf_shut_8_4_5(const struct sctp_endpoint *ep,
3441 const struct sctp_association *asoc,
3442 const sctp_subtype_t type,
3443 void *arg,
3444 sctp_cmd_seq_t *commands)
3445{
3446 struct sctp_packet *packet = NULL;
3447 struct sctp_chunk *chunk = arg;
3448 struct sctp_chunk *shut;
2ce95503 3449 struct net *net;
1da177e4 3450
2ce95503
EB
3451 net = sock_net(ep->base.sk);
3452 packet = sctp_ootb_pkt_new(net, asoc, chunk);
1da177e4
LT
3453
3454 if (packet) {
3455 /* Make an SHUTDOWN_COMPLETE.
d808ad9a
YH
3456 * The T bit will be set if the asoc is NULL.
3457 */
1da177e4
LT
3458 shut = sctp_make_shutdown_complete(asoc, chunk);
3459 if (!shut) {
3460 sctp_ootb_pkt_free(packet);
3461 return SCTP_DISPOSITION_NOMEM;
3462 }
3463
047a2428
JF
3464 /* Reflect vtag if T-Bit is set */
3465 if (sctp_test_T_bit(shut))
3466 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3467
1da177e4
LT
3468 /* Set the skb to the belonging sock for accounting. */
3469 shut->skb->sk = ep->base.sk;
3470
3471 sctp_packet_append_chunk(packet, shut);
3472
3473 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3474 SCTP_PACKET(packet));
3475
b01a2407 3476 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
1da177e4
LT
3477
3478 /* If the chunk length is invalid, we don't want to process
3479 * the reset of the packet.
3480 */
3481 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3482 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3483
d3f25968
VY
3484 /* We need to discard the rest of the packet to prevent
3485 * potential bomming attacks from additional bundled chunks.
3486 * This is documented in SCTP Threats ID.
3487 */
3488 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1da177e4
LT
3489 }
3490
3491 return SCTP_DISPOSITION_NOMEM;
3492}
3493
3494/*
3495 * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state.
3496 *
3497 * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK
3498 * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the
3499 * procedures in section 8.4 SHOULD be followed, in other words it
3500 * should be treated as an Out Of The Blue packet.
3501 * [This means that we do NOT check the Verification Tag on these
3502 * chunks. --piggy ]
3503 *
3504 */
3505sctp_disposition_t sctp_sf_do_8_5_1_E_sa(const struct sctp_endpoint *ep,
3506 const struct sctp_association *asoc,
3507 const sctp_subtype_t type,
3508 void *arg,
3509 sctp_cmd_seq_t *commands)
3510{
ece25dfa
VY
3511 struct sctp_chunk *chunk = arg;
3512
3513 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3514 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3515 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3516 commands);
3517
1da177e4
LT
3518 /* Although we do have an association in this case, it corresponds
3519 * to a restarted association. So the packet is treated as an OOTB
3520 * packet and the state function that handles OOTB SHUTDOWN_ACK is
3521 * called with a NULL association.
3522 */
b01a2407 3523 SCTP_INC_STATS(sock_net(ep->base.sk), SCTP_MIB_OUTOFBLUES);
8190f89d 3524
1da177e4
LT
3525 return sctp_sf_shut_8_4_5(ep, NULL, type, arg, commands);
3526}
3527
3528/* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */
3529sctp_disposition_t sctp_sf_do_asconf(const struct sctp_endpoint *ep,
3530 const struct sctp_association *asoc,
3531 const sctp_subtype_t type, void *arg,
3532 sctp_cmd_seq_t *commands)
3533{
3534 struct sctp_chunk *chunk = arg;
3535 struct sctp_chunk *asconf_ack = NULL;
6f4c618d 3536 struct sctp_paramhdr *err_param = NULL;
1da177e4 3537 sctp_addiphdr_t *hdr;
6f4c618d 3538 union sctp_addr_param *addr_param;
1da177e4 3539 __u32 serial;
6f4c618d 3540 int length;
1da177e4
LT
3541
3542 if (!sctp_vtag_verify(chunk, asoc)) {
3543 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3544 SCTP_NULL());
3545 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3546 }
3547
6afd2e83
VY
3548 /* ADD-IP: Section 4.1.1
3549 * This chunk MUST be sent in an authenticated way by using
3550 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3551 * is received unauthenticated it MUST be silently discarded as
3552 * described in [I-D.ietf-tsvwg-sctp-auth].
3553 */
3554 if (!sctp_addip_noauth && !chunk->auth)
3555 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
3556
1da177e4
LT
3557 /* Make sure that the ASCONF ADDIP chunk has a valid length. */
3558 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_addip_chunk_t)))
3559 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3560 commands);
3561
3562 hdr = (sctp_addiphdr_t *)chunk->skb->data;
3563 serial = ntohl(hdr->serial);
3564
6f4c618d
WY
3565 addr_param = (union sctp_addr_param *)hdr->params;
3566 length = ntohs(addr_param->p.length);
3567 if (length < sizeof(sctp_paramhdr_t))
ba016670 3568 return sctp_sf_violation_paramlen(ep, asoc, type, arg,
6f4c618d
WY
3569 (void *)addr_param, commands);
3570
3571 /* Verify the ASCONF chunk before processing it. */
3572 if (!sctp_verify_asconf(asoc,
a08de64d
VY
3573 (sctp_paramhdr_t *)((void *)addr_param + length),
3574 (void *)chunk->chunk_end,
3575 &err_param))
ba016670
WY
3576 return sctp_sf_violation_paramlen(ep, asoc, type, arg,
3577 (void *)err_param, commands);
6f4c618d 3578
a08de64d 3579 /* ADDIP 5.2 E1) Compare the value of the serial number to the value
1da177e4 3580 * the endpoint stored in a new association variable
d808ad9a 3581 * 'Peer-Serial-Number'.
1da177e4
LT
3582 */
3583 if (serial == asoc->peer.addip_serial + 1) {
a08de64d
VY
3584 /* If this is the first instance of ASCONF in the packet,
3585 * we can clean our old ASCONF-ACKs.
3586 */
3587 if (!chunk->has_asconf)
3588 sctp_assoc_clean_asconf_ack_cache(asoc);
3589
3590 /* ADDIP 5.2 E4) When the Sequence Number matches the next one
3591 * expected, process the ASCONF as described below and after
3592 * processing the ASCONF Chunk, append an ASCONF-ACK Chunk to
3593 * the response packet and cache a copy of it (in the event it
3594 * later needs to be retransmitted).
3595 *
3596 * Essentially, do V1-V5.
1da177e4
LT
3597 */
3598 asconf_ack = sctp_process_asconf((struct sctp_association *)
3599 asoc, chunk);
3600 if (!asconf_ack)
3601 return SCTP_DISPOSITION_NOMEM;
a08de64d
VY
3602 } else if (serial < asoc->peer.addip_serial + 1) {
3603 /* ADDIP 5.2 E2)
3604 * If the value found in the Sequence Number is less than the
3605 * ('Peer- Sequence-Number' + 1), simply skip to the next
3606 * ASCONF, and include in the outbound response packet
3607 * any previously cached ASCONF-ACK response that was
3608 * sent and saved that matches the Sequence Number of the
3609 * ASCONF. Note: It is possible that no cached ASCONF-ACK
3610 * Chunk exists. This will occur when an older ASCONF
3611 * arrives out of order. In such a case, the receiver
3612 * should skip the ASCONF Chunk and not include ASCONF-ACK
3613 * Chunk for that chunk.
1da177e4 3614 */
a08de64d
VY
3615 asconf_ack = sctp_assoc_lookup_asconf_ack(asoc, hdr->serial);
3616 if (!asconf_ack)
1da177e4 3617 return SCTP_DISPOSITION_DISCARD;
31b02e15
VY
3618
3619 /* Reset the transport so that we select the correct one
3620 * this time around. This is to make sure that we don't
3621 * accidentally use a stale transport that's been removed.
3622 */
3623 asconf_ack->transport = NULL;
1da177e4 3624 } else {
a08de64d 3625 /* ADDIP 5.2 E5) Otherwise, the ASCONF Chunk is discarded since
1da177e4 3626 * it must be either a stale packet or from an attacker.
d808ad9a 3627 */
1da177e4
LT
3628 return SCTP_DISPOSITION_DISCARD;
3629 }
3630
a08de64d
VY
3631 /* ADDIP 5.2 E6) The destination address of the SCTP packet
3632 * containing the ASCONF-ACK Chunks MUST be the source address of
3633 * the SCTP packet that held the ASCONF Chunks.
3634 *
3635 * To do this properly, we'll set the destination address of the chunk
3636 * and at the transmit time, will try look up the transport to use.
3637 * Since ASCONFs may be bundled, the correct transport may not be
94e2bd68 3638 * created until we process the entire packet, thus this workaround.
1da177e4 3639 */
a08de64d 3640 asconf_ack->dest = chunk->source;
1da177e4 3641 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(asconf_ack));
6af29ccc
MH
3642 if (asoc->new_transport) {
3643 sctp_sf_heartbeat(ep, asoc, type, asoc->new_transport,
3644 commands);
3645 ((struct sctp_association *)asoc)->new_transport = NULL;
3646 }
d808ad9a 3647
1da177e4
LT
3648 return SCTP_DISPOSITION_CONSUME;
3649}
3650
3651/*
3652 * ADDIP Section 4.3 General rules for address manipulation
3653 * When building TLV parameters for the ASCONF Chunk that will add or
3654 * delete IP addresses the D0 to D13 rules should be applied:
3655 */
3656sctp_disposition_t sctp_sf_do_asconf_ack(const struct sctp_endpoint *ep,
3657 const struct sctp_association *asoc,
d808ad9a 3658 const sctp_subtype_t type, void *arg,
1da177e4
LT
3659 sctp_cmd_seq_t *commands)
3660{
3661 struct sctp_chunk *asconf_ack = arg;
3662 struct sctp_chunk *last_asconf = asoc->addip_last_asconf;
3663 struct sctp_chunk *abort;
6f4c618d 3664 struct sctp_paramhdr *err_param = NULL;
1da177e4
LT
3665 sctp_addiphdr_t *addip_hdr;
3666 __u32 sent_serial, rcvd_serial;
3667
3668 if (!sctp_vtag_verify(asconf_ack, asoc)) {
3669 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3670 SCTP_NULL());
3671 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3672 }
3673
6afd2e83
VY
3674 /* ADD-IP, Section 4.1.2:
3675 * This chunk MUST be sent in an authenticated way by using
3676 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3677 * is received unauthenticated it MUST be silently discarded as
3678 * described in [I-D.ietf-tsvwg-sctp-auth].
3679 */
3680 if (!sctp_addip_noauth && !asconf_ack->auth)
3681 return sctp_sf_discard_chunk(ep, asoc, type, arg, commands);
3682
1da177e4
LT
3683 /* Make sure that the ADDIP chunk has a valid length. */
3684 if (!sctp_chunk_length_valid(asconf_ack, sizeof(sctp_addip_chunk_t)))
3685 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3686 commands);
3687
3688 addip_hdr = (sctp_addiphdr_t *)asconf_ack->skb->data;
3689 rcvd_serial = ntohl(addip_hdr->serial);
3690
6f4c618d
WY
3691 /* Verify the ASCONF-ACK chunk before processing it. */
3692 if (!sctp_verify_asconf(asoc,
3693 (sctp_paramhdr_t *)addip_hdr->params,
3694 (void *)asconf_ack->chunk_end,
3695 &err_param))
ba016670
WY
3696 return sctp_sf_violation_paramlen(ep, asoc, type, arg,
3697 (void *)err_param, commands);
6f4c618d 3698
1da177e4
LT
3699 if (last_asconf) {
3700 addip_hdr = (sctp_addiphdr_t *)last_asconf->subh.addip_hdr;
3701 sent_serial = ntohl(addip_hdr->serial);
3702 } else {
3703 sent_serial = asoc->addip_serial - 1;
3704 }
3705
3706 /* D0) If an endpoint receives an ASCONF-ACK that is greater than or
3707 * equal to the next serial number to be used but no ASCONF chunk is
3708 * outstanding the endpoint MUST ABORT the association. Note that a
3709 * sequence number is greater than if it is no more than 2^^31-1
3710 * larger than the current sequence number (using serial arithmetic).
3711 */
3712 if (ADDIP_SERIAL_gte(rcvd_serial, sent_serial + 1) &&
3713 !(asoc->addip_last_asconf)) {
b01a2407 3714 struct net *net;
1da177e4
LT
3715 abort = sctp_make_abort(asoc, asconf_ack,
3716 sizeof(sctp_errhdr_t));
3717 if (abort) {
00f1c2df 3718 sctp_init_cause(abort, SCTP_ERROR_ASCONF_ACK, 0);
1da177e4
LT
3719 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3720 SCTP_CHUNK(abort));
3721 }
3722 /* We are going to ABORT, so we might as well stop
3723 * processing the rest of the chunks in the packet.
3724 */
3725 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3726 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3727 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
8de8c873 3728 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
d808ad9a 3729 SCTP_ERROR(ECONNABORTED));
1da177e4 3730 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5be291fe 3731 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
b01a2407
EB
3732 net = sock_net(asoc->base.sk);
3733 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
3734 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
1da177e4
LT
3735 return SCTP_DISPOSITION_ABORT;
3736 }
3737
3738 if ((rcvd_serial == sent_serial) && asoc->addip_last_asconf) {
b01a2407 3739 struct net *net;
1da177e4
LT
3740 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3741 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3742
3743 if (!sctp_process_asconf_ack((struct sctp_association *)asoc,
c0786693
VY
3744 asconf_ack)) {
3745 /* Successfully processed ASCONF_ACK. We can
3746 * release the next asconf if we have one.
3747 */
3748 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_NEXT_ASCONF,
3749 SCTP_NULL());
1da177e4 3750 return SCTP_DISPOSITION_CONSUME;
c0786693 3751 }
1da177e4
LT
3752
3753 abort = sctp_make_abort(asoc, asconf_ack,
3754 sizeof(sctp_errhdr_t));
3755 if (abort) {
00f1c2df 3756 sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0);
1da177e4
LT
3757 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3758 SCTP_CHUNK(abort));
3759 }
3760 /* We are going to ABORT, so we might as well stop
3761 * processing the rest of the chunks in the packet.
3762 */
3763 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
8de8c873 3764 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
d808ad9a 3765 SCTP_ERROR(ECONNABORTED));
1da177e4 3766 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5be291fe 3767 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
b01a2407
EB
3768 net = sock_net(asoc->base.sk);
3769 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
3770 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
1da177e4
LT
3771 return SCTP_DISPOSITION_ABORT;
3772 }
3773
3774 return SCTP_DISPOSITION_DISCARD;
3775}
3776
3777/*
3778 * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP
3779 *
3780 * When a FORWARD TSN chunk arrives, the data receiver MUST first update
3781 * its cumulative TSN point to the value carried in the FORWARD TSN
3782 * chunk, and then MUST further advance its cumulative TSN point locally
3783 * if possible.
3784 * After the above processing, the data receiver MUST stop reporting any
3785 * missing TSNs earlier than or equal to the new cumulative TSN point.
3786 *
3787 * Verification Tag: 8.5 Verification Tag [Normal verification]
3788 *
3789 * The return value is the disposition of the chunk.
3790 */
3791sctp_disposition_t sctp_sf_eat_fwd_tsn(const struct sctp_endpoint *ep,
3792 const struct sctp_association *asoc,
3793 const sctp_subtype_t type,
3794 void *arg,
3795 sctp_cmd_seq_t *commands)
3796{
3797 struct sctp_chunk *chunk = arg;
3798 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
9fcb95a1 3799 struct sctp_fwdtsn_skip *skip;
1da177e4
LT
3800 __u16 len;
3801 __u32 tsn;
3802
3803 if (!sctp_vtag_verify(chunk, asoc)) {
3804 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3805 SCTP_NULL());
3806 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3807 }
3808
3809 /* Make sure that the FORWARD_TSN chunk has valid length. */
3810 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
3811 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3812 commands);
3813
3814 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3815 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3816 len = ntohs(chunk->chunk_hdr->length);
3817 len -= sizeof(struct sctp_chunkhdr);
3818 skb_pull(chunk->skb, len);
3819
3820 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
0dc47877 3821 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __func__, tsn);
1da177e4
LT
3822
3823 /* The TSN is too high--silently discard the chunk and count on it
3824 * getting retransmitted later.
3825 */
3826 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3827 goto discard_noforce;
3828
9fcb95a1
WY
3829 /* Silently discard the chunk if stream-id is not valid */
3830 sctp_walk_fwdtsn(skip, chunk) {
3831 if (ntohs(skip->stream) >= asoc->c.sinit_max_instreams)
3832 goto discard_noforce;
3833 }
3834
1da177e4
LT
3835 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3836 if (len > sizeof(struct sctp_fwdtsn_hdr))
d808ad9a 3837 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
1da177e4 3838 SCTP_CHUNK(chunk));
d808ad9a 3839
1da177e4
LT
3840 /* Count this as receiving DATA. */
3841 if (asoc->autoclose) {
3842 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3843 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
3844 }
d808ad9a 3845
1da177e4 3846 /* FIXME: For now send a SACK, but DATA processing may
d808ad9a 3847 * send another.
1da177e4
LT
3848 */
3849 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
1da177e4
LT
3850
3851 return SCTP_DISPOSITION_CONSUME;
3852
3853discard_noforce:
3854 return SCTP_DISPOSITION_DISCARD;
3855}
3856
3857sctp_disposition_t sctp_sf_eat_fwd_tsn_fast(
3858 const struct sctp_endpoint *ep,
3859 const struct sctp_association *asoc,
3860 const sctp_subtype_t type,
3861 void *arg,
3862 sctp_cmd_seq_t *commands)
3863{
3864 struct sctp_chunk *chunk = arg;
3865 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
9fcb95a1 3866 struct sctp_fwdtsn_skip *skip;
1da177e4
LT
3867 __u16 len;
3868 __u32 tsn;
3869
3870 if (!sctp_vtag_verify(chunk, asoc)) {
3871 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3872 SCTP_NULL());
3873 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3874 }
3875
3876 /* Make sure that the FORWARD_TSN chunk has a valid length. */
3877 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
3878 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3879 commands);
3880
3881 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3882 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3883 len = ntohs(chunk->chunk_hdr->length);
3884 len -= sizeof(struct sctp_chunkhdr);
3885 skb_pull(chunk->skb, len);
3886
3887 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
0dc47877 3888 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __func__, tsn);
1da177e4
LT
3889
3890 /* The TSN is too high--silently discard the chunk and count on it
3891 * getting retransmitted later.
3892 */
3893 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3894 goto gen_shutdown;
3895
9fcb95a1
WY
3896 /* Silently discard the chunk if stream-id is not valid */
3897 sctp_walk_fwdtsn(skip, chunk) {
3898 if (ntohs(skip->stream) >= asoc->c.sinit_max_instreams)
3899 goto gen_shutdown;
3900 }
3901
1da177e4
LT
3902 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3903 if (len > sizeof(struct sctp_fwdtsn_hdr))
d808ad9a 3904 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
1da177e4 3905 SCTP_CHUNK(chunk));
d808ad9a 3906
1da177e4
LT
3907 /* Go a head and force a SACK, since we are shutting down. */
3908gen_shutdown:
3909 /* Implementor's Guide.
3910 *
3911 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3912 * respond to each received packet containing one or more DATA chunk(s)
3913 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3914 */
3915 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
3916 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3917 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3918 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3919
d808ad9a 3920 return SCTP_DISPOSITION_CONSUME;
1da177e4
LT
3921}
3922
bbd0d598 3923/*
25985edc 3924 * SCTP-AUTH Section 6.3 Receiving authenticated chukns
bbd0d598
VY
3925 *
3926 * The receiver MUST use the HMAC algorithm indicated in the HMAC
3927 * Identifier field. If this algorithm was not specified by the
3928 * receiver in the HMAC-ALGO parameter in the INIT or INIT-ACK chunk
3929 * during association setup, the AUTH chunk and all chunks after it MUST
3930 * be discarded and an ERROR chunk SHOULD be sent with the error cause
3931 * defined in Section 4.1.
3932 *
3933 * If an endpoint with no shared key receives a Shared Key Identifier
3934 * other than 0, it MUST silently discard all authenticated chunks. If
3935 * the endpoint has at least one endpoint pair shared key for the peer,
3936 * it MUST use the key specified by the Shared Key Identifier if a
3937 * key has been configured for that Shared Key Identifier. If no
3938 * endpoint pair shared key has been configured for that Shared Key
3939 * Identifier, all authenticated chunks MUST be silently discarded.
3940 *
3941 * Verification Tag: 8.5 Verification Tag [Normal verification]
3942 *
3943 * The return value is the disposition of the chunk.
3944 */
3945static sctp_ierror_t sctp_sf_authenticate(const struct sctp_endpoint *ep,
3946 const struct sctp_association *asoc,
3947 const sctp_subtype_t type,
3948 struct sctp_chunk *chunk)
3949{
3950 struct sctp_authhdr *auth_hdr;
3951 struct sctp_hmac *hmac;
3952 unsigned int sig_len;
3953 __u16 key_id;
3954 __u8 *save_digest;
3955 __u8 *digest;
3956
3957 /* Pull in the auth header, so we can do some more verification */
3958 auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
3959 chunk->subh.auth_hdr = auth_hdr;
3960 skb_pull(chunk->skb, sizeof(struct sctp_authhdr));
3961
3962 /* Make sure that we suport the HMAC algorithm from the auth
3963 * chunk.
3964 */
3965 if (!sctp_auth_asoc_verify_hmac_id(asoc, auth_hdr->hmac_id))
3966 return SCTP_IERROR_AUTH_BAD_HMAC;
3967
3968 /* Make sure that the provided shared key identifier has been
3969 * configured
3970 */
3971 key_id = ntohs(auth_hdr->shkey_id);
3972 if (key_id != asoc->active_key_id && !sctp_auth_get_shkey(asoc, key_id))
3973 return SCTP_IERROR_AUTH_BAD_KEYID;
3974
3975
3976 /* Make sure that the length of the signature matches what
3977 * we expect.
3978 */
3979 sig_len = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_auth_chunk_t);
3980 hmac = sctp_auth_get_hmac(ntohs(auth_hdr->hmac_id));
3981 if (sig_len != hmac->hmac_len)
3982 return SCTP_IERROR_PROTO_VIOLATION;
3983
3984 /* Now that we've done validation checks, we can compute and
3985 * verify the hmac. The steps involved are:
3986 * 1. Save the digest from the chunk.
3987 * 2. Zero out the digest in the chunk.
3988 * 3. Compute the new digest
3989 * 4. Compare saved and new digests.
3990 */
3991 digest = auth_hdr->hmac;
3992 skb_pull(chunk->skb, sig_len);
3993
3994 save_digest = kmemdup(digest, sig_len, GFP_ATOMIC);
3995 if (!save_digest)
3996 goto nomem;
3997
3998 memset(digest, 0, sig_len);
3999
4000 sctp_auth_calculate_hmac(asoc, chunk->skb,
4001 (struct sctp_auth_chunk *)chunk->chunk_hdr,
4002 GFP_ATOMIC);
4003
4004 /* Discard the packet if the digests do not match */
4005 if (memcmp(save_digest, digest, sig_len)) {
4006 kfree(save_digest);
4007 return SCTP_IERROR_BAD_SIG;
4008 }
4009
4010 kfree(save_digest);
4011 chunk->auth = 1;
4012
4013 return SCTP_IERROR_NO_ERROR;
4014nomem:
4015 return SCTP_IERROR_NOMEM;
4016}
4017
4018sctp_disposition_t sctp_sf_eat_auth(const struct sctp_endpoint *ep,
4019 const struct sctp_association *asoc,
4020 const sctp_subtype_t type,
4021 void *arg,
4022 sctp_cmd_seq_t *commands)
4023{
4024 struct sctp_authhdr *auth_hdr;
4025 struct sctp_chunk *chunk = arg;
4026 struct sctp_chunk *err_chunk;
4027 sctp_ierror_t error;
4028
d2f19fa1
WY
4029 /* Make sure that the peer has AUTH capable */
4030 if (!asoc->peer.auth_capable)
4031 return sctp_sf_unk_chunk(ep, asoc, type, arg, commands);
4032
bbd0d598
VY
4033 if (!sctp_vtag_verify(chunk, asoc)) {
4034 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
4035 SCTP_NULL());
4036 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
4037 }
4038
4039 /* Make sure that the AUTH chunk has valid length. */
4040 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_auth_chunk)))
4041 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
4042 commands);
4043
4044 auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
4045 error = sctp_sf_authenticate(ep, asoc, type, chunk);
4046 switch (error) {
7fd71b1e
JP
4047 case SCTP_IERROR_AUTH_BAD_HMAC:
4048 /* Generate the ERROR chunk and discard the rest
4049 * of the packet
4050 */
4051 err_chunk = sctp_make_op_error(asoc, chunk,
4052 SCTP_ERROR_UNSUP_HMAC,
4053 &auth_hdr->hmac_id,
4054 sizeof(__u16), 0);
4055 if (err_chunk) {
4056 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4057 SCTP_CHUNK(err_chunk));
4058 }
4059 /* Fall Through */
4060 case SCTP_IERROR_AUTH_BAD_KEYID:
4061 case SCTP_IERROR_BAD_SIG:
4062 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
4063
4064 case SCTP_IERROR_PROTO_VIOLATION:
4065 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
4066 commands);
4067
4068 case SCTP_IERROR_NOMEM:
4069 return SCTP_DISPOSITION_NOMEM;
4070
4071 default: /* Prevent gcc warnings */
4072 break;
bbd0d598
VY
4073 }
4074
65b07e5d
VY
4075 if (asoc->active_key_id != ntohs(auth_hdr->shkey_id)) {
4076 struct sctp_ulpevent *ev;
4077
4078 ev = sctp_ulpevent_make_authkey(asoc, ntohs(auth_hdr->shkey_id),
4079 SCTP_AUTH_NEWKEY, GFP_ATOMIC);
4080
4081 if (!ev)
4082 return -ENOMEM;
4083
4084 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
4085 SCTP_ULPEVENT(ev));
4086 }
4087
bbd0d598
VY
4088 return SCTP_DISPOSITION_CONSUME;
4089}
4090
1da177e4
LT
4091/*
4092 * Process an unknown chunk.
4093 *
4094 * Section: 3.2. Also, 2.1 in the implementor's guide.
4095 *
4096 * Chunk Types are encoded such that the highest-order two bits specify
4097 * the action that must be taken if the processing endpoint does not
4098 * recognize the Chunk Type.
4099 *
4100 * 00 - Stop processing this SCTP packet and discard it, do not process
4101 * any further chunks within it.
4102 *
4103 * 01 - Stop processing this SCTP packet and discard it, do not process
4104 * any further chunks within it, and report the unrecognized
4105 * chunk in an 'Unrecognized Chunk Type'.
4106 *
4107 * 10 - Skip this chunk and continue processing.
4108 *
4109 * 11 - Skip this chunk and continue processing, but report in an ERROR
4110 * Chunk using the 'Unrecognized Chunk Type' cause of error.
4111 *
4112 * The return value is the disposition of the chunk.
4113 */
4114sctp_disposition_t sctp_sf_unk_chunk(const struct sctp_endpoint *ep,
4115 const struct sctp_association *asoc,
4116 const sctp_subtype_t type,
4117 void *arg,
4118 sctp_cmd_seq_t *commands)
4119{
4120 struct sctp_chunk *unk_chunk = arg;
4121 struct sctp_chunk *err_chunk;
4122 sctp_chunkhdr_t *hdr;
4123
4124 SCTP_DEBUG_PRINTK("Processing the unknown chunk id %d.\n", type.chunk);
4125
4126 if (!sctp_vtag_verify(unk_chunk, asoc))
4127 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
4128
4129 /* Make sure that the chunk has a valid length.
4130 * Since we don't know the chunk type, we use a general
4131 * chunkhdr structure to make a comparison.
4132 */
4133 if (!sctp_chunk_length_valid(unk_chunk, sizeof(sctp_chunkhdr_t)))
4134 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
4135 commands);
4136
4137 switch (type.chunk & SCTP_CID_ACTION_MASK) {
4138 case SCTP_CID_ACTION_DISCARD:
4139 /* Discard the packet. */
4140 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
4141 break;
4142 case SCTP_CID_ACTION_DISCARD_ERR:
1da177e4
LT
4143 /* Generate an ERROR chunk as response. */
4144 hdr = unk_chunk->chunk_hdr;
4145 err_chunk = sctp_make_op_error(asoc, unk_chunk,
4146 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
6383cfb3
VY
4147 WORD_ROUND(ntohs(hdr->length)),
4148 0);
1da177e4
LT
4149 if (err_chunk) {
4150 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4151 SCTP_CHUNK(err_chunk));
4152 }
2e3216cd
VY
4153
4154 /* Discard the packet. */
4155 sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1da177e4
LT
4156 return SCTP_DISPOSITION_CONSUME;
4157 break;
4158 case SCTP_CID_ACTION_SKIP:
4159 /* Skip the chunk. */
4160 return SCTP_DISPOSITION_DISCARD;
4161 break;
4162 case SCTP_CID_ACTION_SKIP_ERR:
4163 /* Generate an ERROR chunk as response. */
4164 hdr = unk_chunk->chunk_hdr;
4165 err_chunk = sctp_make_op_error(asoc, unk_chunk,
4166 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
6383cfb3
VY
4167 WORD_ROUND(ntohs(hdr->length)),
4168 0);
1da177e4
LT
4169 if (err_chunk) {
4170 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4171 SCTP_CHUNK(err_chunk));
4172 }
4173 /* Skip the chunk. */
4174 return SCTP_DISPOSITION_CONSUME;
4175 break;
4176 default:
4177 break;
4178 }
4179
4180 return SCTP_DISPOSITION_DISCARD;
4181}
4182
4183/*
4184 * Discard the chunk.
4185 *
4186 * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2
4187 * [Too numerous to mention...]
4188 * Verification Tag: No verification needed.
4189 * Inputs
4190 * (endpoint, asoc, chunk)
4191 *
4192 * Outputs
4193 * (asoc, reply_msg, msg_up, timers, counters)
4194 *
4195 * The return value is the disposition of the chunk.
4196 */
4197sctp_disposition_t sctp_sf_discard_chunk(const struct sctp_endpoint *ep,
4198 const struct sctp_association *asoc,
4199 const sctp_subtype_t type,
4200 void *arg,
4201 sctp_cmd_seq_t *commands)
4202{
ece25dfa
VY
4203 struct sctp_chunk *chunk = arg;
4204
4205 /* Make sure that the chunk has a valid length.
4206 * Since we don't know the chunk type, we use a general
4207 * chunkhdr structure to make a comparison.
4208 */
4209 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
4210 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
4211 commands);
4212
1da177e4
LT
4213 SCTP_DEBUG_PRINTK("Chunk %d is discarded\n", type.chunk);
4214 return SCTP_DISPOSITION_DISCARD;
4215}
4216
4217/*
4218 * Discard the whole packet.
4219 *
4220 * Section: 8.4 2)
4221 *
4222 * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST
4223 * silently discard the OOTB packet and take no further action.
1da177e4
LT
4224 *
4225 * Verification Tag: No verification necessary
4226 *
4227 * Inputs
4228 * (endpoint, asoc, chunk)
4229 *
4230 * Outputs
4231 * (asoc, reply_msg, msg_up, timers, counters)
4232 *
4233 * The return value is the disposition of the chunk.
4234 */
4235sctp_disposition_t sctp_sf_pdiscard(const struct sctp_endpoint *ep,
4236 const struct sctp_association *asoc,
4237 const sctp_subtype_t type,
4238 void *arg,
4239 sctp_cmd_seq_t *commands)
4240{
b01a2407 4241 SCTP_INC_STATS(sock_net(asoc->base.sk), SCTP_MIB_IN_PKT_DISCARDS);
1da177e4
LT
4242 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
4243
4244 return SCTP_DISPOSITION_CONSUME;
4245}
4246
4247
4248/*
4249 * The other end is violating protocol.
4250 *
4251 * Section: Not specified
4252 * Verification Tag: Not specified
4253 * Inputs
4254 * (endpoint, asoc, chunk)
4255 *
4256 * Outputs
4257 * (asoc, reply_msg, msg_up, timers, counters)
4258 *
4259 * We simply tag the chunk as a violation. The state machine will log
4260 * the violation and continue.
4261 */
4262sctp_disposition_t sctp_sf_violation(const struct sctp_endpoint *ep,
4263 const struct sctp_association *asoc,
4264 const sctp_subtype_t type,
4265 void *arg,
4266 sctp_cmd_seq_t *commands)
4267{
ece25dfa
VY
4268 struct sctp_chunk *chunk = arg;
4269
4270 /* Make sure that the chunk has a valid length. */
4271 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
4272 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
4273 commands);
4274
1da177e4
LT
4275 return SCTP_DISPOSITION_VIOLATION;
4276}
4277
1da177e4 4278/*
aecedeab 4279 * Common function to handle a protocol violation.
1da177e4 4280 */
aecedeab 4281static sctp_disposition_t sctp_sf_abort_violation(
ece25dfa 4282 const struct sctp_endpoint *ep,
1da177e4 4283 const struct sctp_association *asoc,
1da177e4 4284 void *arg,
aecedeab
WY
4285 sctp_cmd_seq_t *commands,
4286 const __u8 *payload,
4287 const size_t paylen)
1da177e4 4288{
ece25dfa 4289 struct sctp_packet *packet = NULL;
1da177e4
LT
4290 struct sctp_chunk *chunk = arg;
4291 struct sctp_chunk *abort = NULL;
2ce95503 4292 struct net *net;
1da177e4 4293
bbd0d598
VY
4294 /* SCTP-AUTH, Section 6.3:
4295 * It should be noted that if the receiver wants to tear
4296 * down an association in an authenticated way only, the
4297 * handling of malformed packets should not result in
4298 * tearing down the association.
4299 *
4300 * This means that if we only want to abort associations
4301 * in an authenticated way (i.e AUTH+ABORT), then we
25985edc 4302 * can't destroy this association just because the packet
bbd0d598
VY
4303 * was malformed.
4304 */
4305 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
4306 goto discard;
4307
9abed245
JJ
4308 /* Make the abort chunk. */
4309 abort = sctp_make_abort_violation(asoc, chunk, payload, paylen);
4310 if (!abort)
4311 goto nomem;
4312
2ce95503 4313 net = sock_net(ep->base.sk);
ece25dfa 4314 if (asoc) {
f4ad85ca
GJ
4315 /* Treat INIT-ACK as a special case during COOKIE-WAIT. */
4316 if (chunk->chunk_hdr->type == SCTP_CID_INIT_ACK &&
4317 !asoc->peer.i.init_tag) {
4318 sctp_initack_chunk_t *initack;
4319
4320 initack = (sctp_initack_chunk_t *)chunk->chunk_hdr;
4321 if (!sctp_chunk_length_valid(chunk,
4322 sizeof(sctp_initack_chunk_t)))
4323 abort->chunk_hdr->flags |= SCTP_CHUNK_FLAG_T;
4324 else {
4325 unsigned int inittag;
4326
4327 inittag = ntohl(initack->init_hdr.init_tag);
4328 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_INITTAG,
4329 SCTP_U32(inittag));
4330 }
4331 }
4332
ece25dfa 4333 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
b01a2407 4334 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
1da177e4 4335
ece25dfa
VY
4336 if (asoc->state <= SCTP_STATE_COOKIE_ECHOED) {
4337 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4338 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4339 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4340 SCTP_ERROR(ECONNREFUSED));
4341 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
4342 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4343 } else {
4344 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4345 SCTP_ERROR(ECONNABORTED));
4346 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4347 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
b01a2407 4348 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
ece25dfa 4349 }
1da177e4 4350 } else {
2ce95503 4351 packet = sctp_ootb_pkt_new(net, asoc, chunk);
ece25dfa
VY
4352
4353 if (!packet)
4354 goto nomem_pkt;
4355
4356 if (sctp_test_T_bit(abort))
4357 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
4358
4359 abort->skb->sk = ep->base.sk;
4360
4361 sctp_packet_append_chunk(packet, abort);
4362
4363 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
4364 SCTP_PACKET(packet));
4365
b01a2407 4366 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
1da177e4
LT
4367 }
4368
b01a2407 4369 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
d808ad9a 4370
56eb82bb
VY
4371discard:
4372 sctp_sf_pdiscard(ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
1da177e4
LT
4373 return SCTP_DISPOSITION_ABORT;
4374
ece25dfa
VY
4375nomem_pkt:
4376 sctp_chunk_free(abort);
1da177e4
LT
4377nomem:
4378 return SCTP_DISPOSITION_NOMEM;
4379}
4380
aecedeab
WY
4381/*
4382 * Handle a protocol violation when the chunk length is invalid.
025dfdaf 4383 * "Invalid" length is identified as smaller than the minimal length a
aecedeab 4384 * given chunk can be. For example, a SACK chunk has invalid length
025dfdaf 4385 * if its length is set to be smaller than the size of sctp_sack_chunk_t.
aecedeab
WY
4386 *
4387 * We inform the other end by sending an ABORT with a Protocol Violation
4388 * error code.
4389 *
4390 * Section: Not specified
4391 * Verification Tag: Nothing to do
4392 * Inputs
4393 * (endpoint, asoc, chunk)
4394 *
4395 * Outputs
4396 * (reply_msg, msg_up, counters)
4397 *
4398 * Generate an ABORT chunk and terminate the association.
4399 */
4400static sctp_disposition_t sctp_sf_violation_chunklen(
4401 const struct sctp_endpoint *ep,
4402 const struct sctp_association *asoc,
4403 const sctp_subtype_t type,
4404 void *arg,
4405 sctp_cmd_seq_t *commands)
4406{
2444844c 4407 static const char err_str[]="The following chunk had invalid length:";
aecedeab 4408
ece25dfa 4409 return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
aecedeab
WY
4410 sizeof(err_str));
4411}
4412
6f4c618d
WY
4413/*
4414 * Handle a protocol violation when the parameter length is invalid.
33c7cfdb
SW
4415 * If the length is smaller than the minimum length of a given parameter,
4416 * or accumulated length in multi parameters exceeds the end of the chunk,
4417 * the length is considered as invalid.
6f4c618d
WY
4418 */
4419static sctp_disposition_t sctp_sf_violation_paramlen(
4420 const struct sctp_endpoint *ep,
4421 const struct sctp_association *asoc,
4422 const sctp_subtype_t type,
ba016670
WY
4423 void *arg, void *ext,
4424 sctp_cmd_seq_t *commands)
4425{
4426 struct sctp_chunk *chunk = arg;
4427 struct sctp_paramhdr *param = ext;
4428 struct sctp_chunk *abort = NULL;
b01a2407 4429 struct net *net;
6f4c618d 4430
ba016670
WY
4431 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
4432 goto discard;
4433
4434 /* Make the abort chunk. */
4435 abort = sctp_make_violation_paramlen(asoc, chunk, param);
4436 if (!abort)
4437 goto nomem;
4438
b01a2407 4439 net = sock_net(asoc->base.sk);
ba016670 4440 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
b01a2407 4441 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
ba016670
WY
4442
4443 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4444 SCTP_ERROR(ECONNABORTED));
4445 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4446 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
b01a2407
EB
4447 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
4448 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
ba016670
WY
4449
4450discard:
4451 sctp_sf_pdiscard(ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
ba016670
WY
4452 return SCTP_DISPOSITION_ABORT;
4453nomem:
4454 return SCTP_DISPOSITION_NOMEM;
6f4c618d
WY
4455}
4456
aecedeab
WY
4457/* Handle a protocol violation when the peer trying to advance the
4458 * cumulative tsn ack to a point beyond the max tsn currently sent.
4459 *
4460 * We inform the other end by sending an ABORT with a Protocol Violation
4461 * error code.
4462 */
4463static sctp_disposition_t sctp_sf_violation_ctsn(
4464 const struct sctp_endpoint *ep,
4465 const struct sctp_association *asoc,
4466 const sctp_subtype_t type,
4467 void *arg,
4468 sctp_cmd_seq_t *commands)
4469{
2444844c 4470 static const char err_str[]="The cumulative tsn ack beyond the max tsn currently sent:";
aecedeab 4471
ece25dfa 4472 return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
aecedeab
WY
4473 sizeof(err_str));
4474}
4475
ece25dfa 4476/* Handle protocol violation of an invalid chunk bundling. For example,
25985edc 4477 * when we have an association and we receive bundled INIT-ACK, or
ece25dfa 4478 * SHUDOWN-COMPLETE, our peer is clearly violationg the "MUST NOT bundle"
25985edc 4479 * statement from the specs. Additionally, there might be an attacker
ece25dfa
VY
4480 * on the path and we may not want to continue this communication.
4481 */
4482static sctp_disposition_t sctp_sf_violation_chunk(
4483 const struct sctp_endpoint *ep,
4484 const struct sctp_association *asoc,
4485 const sctp_subtype_t type,
4486 void *arg,
4487 sctp_cmd_seq_t *commands)
4488{
2444844c 4489 static const char err_str[]="The following chunk violates protocol:";
ece25dfa
VY
4490
4491 if (!asoc)
4492 return sctp_sf_violation(ep, asoc, type, arg, commands);
4493
4494 return sctp_sf_abort_violation(ep, asoc, arg, commands, err_str,
4495 sizeof(err_str));
4496}
1da177e4
LT
4497/***************************************************************************
4498 * These are the state functions for handling primitive (Section 10) events.
4499 ***************************************************************************/
4500/*
4501 * sctp_sf_do_prm_asoc
4502 *
4503 * Section: 10.1 ULP-to-SCTP
4504 * B) Associate
4505 *
4506 * Format: ASSOCIATE(local SCTP instance name, destination transport addr,
4507 * outbound stream count)
4508 * -> association id [,destination transport addr list] [,outbound stream
4509 * count]
4510 *
4511 * This primitive allows the upper layer to initiate an association to a
4512 * specific peer endpoint.
4513 *
4514 * The peer endpoint shall be specified by one of the transport addresses
4515 * which defines the endpoint (see Section 1.4). If the local SCTP
4516 * instance has not been initialized, the ASSOCIATE is considered an
4517 * error.
4518 * [This is not relevant for the kernel implementation since we do all
4519 * initialization at boot time. It we hadn't initialized we wouldn't
4520 * get anywhere near this code.]
4521 *
4522 * An association id, which is a local handle to the SCTP association,
4523 * will be returned on successful establishment of the association. If
4524 * SCTP is not able to open an SCTP association with the peer endpoint,
4525 * an error is returned.
4526 * [In the kernel implementation, the struct sctp_association needs to
4527 * be created BEFORE causing this primitive to run.]
4528 *
4529 * Other association parameters may be returned, including the
4530 * complete destination transport addresses of the peer as well as the
4531 * outbound stream count of the local endpoint. One of the transport
4532 * address from the returned destination addresses will be selected by
4533 * the local endpoint as default primary path for sending SCTP packets
4534 * to this peer. The returned "destination transport addr list" can
4535 * be used by the ULP to change the default primary path or to force
4536 * sending a packet to a specific transport address. [All of this
4537 * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING
4538 * function.]
4539 *
4540 * Mandatory attributes:
4541 *
4542 * o local SCTP instance name - obtained from the INITIALIZE operation.
4543 * [This is the argument asoc.]
4544 * o destination transport addr - specified as one of the transport
4545 * addresses of the peer endpoint with which the association is to be
4546 * established.
4547 * [This is asoc->peer.active_path.]
4548 * o outbound stream count - the number of outbound streams the ULP
4549 * would like to open towards this peer endpoint.
4550 * [BUG: This is not currently implemented.]
4551 * Optional attributes:
4552 *
4553 * None.
4554 *
4555 * The return value is a disposition.
4556 */
4557sctp_disposition_t sctp_sf_do_prm_asoc(const struct sctp_endpoint *ep,
4558 const struct sctp_association *asoc,
4559 const sctp_subtype_t type,
4560 void *arg,
4561 sctp_cmd_seq_t *commands)
4562{
4563 struct sctp_chunk *repl;
ab38fb04 4564 struct sctp_association* my_asoc;
1da177e4
LT
4565
4566 /* The comment below says that we enter COOKIE-WAIT AFTER
4567 * sending the INIT, but that doesn't actually work in our
4568 * implementation...
4569 */
4570 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4571 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
4572
4573 /* RFC 2960 5.1 Normal Establishment of an Association
4574 *
4575 * A) "A" first sends an INIT chunk to "Z". In the INIT, "A"
4576 * must provide its Verification Tag (Tag_A) in the Initiate
4577 * Tag field. Tag_A SHOULD be a random number in the range of
4578 * 1 to 4294967295 (see 5.3.1 for Tag value selection). ...
4579 */
4580
4581 repl = sctp_make_init(asoc, &asoc->base.bind_addr, GFP_ATOMIC, 0);
4582 if (!repl)
4583 goto nomem;
4584
4585 /* Cast away the const modifier, as we want to just
4586 * rerun it through as a sideffect.
4587 */
ab38fb04
VY
4588 my_asoc = (struct sctp_association *)asoc;
4589 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(my_asoc));
1da177e4 4590
3f7a87d2
FF
4591 /* Choose transport for INIT. */
4592 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
4593 SCTP_CHUNK(repl));
4594
1da177e4
LT
4595 /* After sending the INIT, "A" starts the T1-init timer and
4596 * enters the COOKIE-WAIT state.
4597 */
4598 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4599 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4600 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
4601 return SCTP_DISPOSITION_CONSUME;
4602
4603nomem:
4604 return SCTP_DISPOSITION_NOMEM;
4605}
4606
4607/*
4608 * Process the SEND primitive.
4609 *
4610 * Section: 10.1 ULP-to-SCTP
4611 * E) Send
4612 *
4613 * Format: SEND(association id, buffer address, byte count [,context]
4614 * [,stream id] [,life time] [,destination transport address]
4615 * [,unorder flag] [,no-bundle flag] [,payload protocol-id] )
4616 * -> result
4617 *
4618 * This is the main method to send user data via SCTP.
4619 *
4620 * Mandatory attributes:
4621 *
4622 * o association id - local handle to the SCTP association
4623 *
4624 * o buffer address - the location where the user message to be
4625 * transmitted is stored;
4626 *
4627 * o byte count - The size of the user data in number of bytes;
4628 *
4629 * Optional attributes:
4630 *
4631 * o context - an optional 32 bit integer that will be carried in the
4632 * sending failure notification to the ULP if the transportation of
4633 * this User Message fails.
4634 *
4635 * o stream id - to indicate which stream to send the data on. If not
4636 * specified, stream 0 will be used.
4637 *
4638 * o life time - specifies the life time of the user data. The user data
4639 * will not be sent by SCTP after the life time expires. This
4640 * parameter can be used to avoid efforts to transmit stale
4641 * user messages. SCTP notifies the ULP if the data cannot be
4642 * initiated to transport (i.e. sent to the destination via SCTP's
4643 * send primitive) within the life time variable. However, the
4644 * user data will be transmitted if SCTP has attempted to transmit a
4645 * chunk before the life time expired.
4646 *
4647 * o destination transport address - specified as one of the destination
4648 * transport addresses of the peer endpoint to which this packet
4649 * should be sent. Whenever possible, SCTP should use this destination
4650 * transport address for sending the packets, instead of the current
4651 * primary path.
4652 *
4653 * o unorder flag - this flag, if present, indicates that the user
4654 * would like the data delivered in an unordered fashion to the peer
4655 * (i.e., the U flag is set to 1 on all DATA chunks carrying this
4656 * message).
4657 *
4658 * o no-bundle flag - instructs SCTP not to bundle this user data with
4659 * other outbound DATA chunks. SCTP MAY still bundle even when
4660 * this flag is present, when faced with network congestion.
4661 *
4662 * o payload protocol-id - A 32 bit unsigned integer that is to be
4663 * passed to the peer indicating the type of payload protocol data
4664 * being transmitted. This value is passed as opaque data by SCTP.
4665 *
4666 * The return value is the disposition.
4667 */
4668sctp_disposition_t sctp_sf_do_prm_send(const struct sctp_endpoint *ep,
4669 const struct sctp_association *asoc,
4670 const sctp_subtype_t type,
4671 void *arg,
4672 sctp_cmd_seq_t *commands)
4673{
9c5c62be 4674 struct sctp_datamsg *msg = arg;
1da177e4 4675
9c5c62be 4676 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_MSG, SCTP_DATAMSG(msg));
1da177e4
LT
4677 return SCTP_DISPOSITION_CONSUME;
4678}
4679
4680/*
4681 * Process the SHUTDOWN primitive.
4682 *
4683 * Section: 10.1:
4684 * C) Shutdown
4685 *
4686 * Format: SHUTDOWN(association id)
4687 * -> result
4688 *
4689 * Gracefully closes an association. Any locally queued user data
4690 * will be delivered to the peer. The association will be terminated only
4691 * after the peer acknowledges all the SCTP packets sent. A success code
4692 * will be returned on successful termination of the association. If
4693 * attempting to terminate the association results in a failure, an error
4694 * code shall be returned.
4695 *
4696 * Mandatory attributes:
4697 *
4698 * o association id - local handle to the SCTP association
4699 *
4700 * Optional attributes:
4701 *
4702 * None.
4703 *
4704 * The return value is the disposition.
4705 */
4706sctp_disposition_t sctp_sf_do_9_2_prm_shutdown(
4707 const struct sctp_endpoint *ep,
4708 const struct sctp_association *asoc,
4709 const sctp_subtype_t type,
4710 void *arg,
4711 sctp_cmd_seq_t *commands)
4712{
4713 int disposition;
4714
4715 /* From 9.2 Shutdown of an Association
4716 * Upon receipt of the SHUTDOWN primitive from its upper
4717 * layer, the endpoint enters SHUTDOWN-PENDING state and
4718 * remains there until all outstanding data has been
4719 * acknowledged by its peer. The endpoint accepts no new data
4720 * from its upper layer, but retransmits data to the far end
4721 * if necessary to fill gaps.
4722 */
4723 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4724 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
4725
1da177e4
LT
4726 disposition = SCTP_DISPOSITION_CONSUME;
4727 if (sctp_outq_is_empty(&asoc->outqueue)) {
4728 disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type,
4729 arg, commands);
4730 }
4731 return disposition;
4732}
4733
4734/*
4735 * Process the ABORT primitive.
4736 *
4737 * Section: 10.1:
4738 * C) Abort
4739 *
4740 * Format: Abort(association id [, cause code])
4741 * -> result
4742 *
4743 * Ungracefully closes an association. Any locally queued user data
4744 * will be discarded and an ABORT chunk is sent to the peer. A success code
4745 * will be returned on successful abortion of the association. If
4746 * attempting to abort the association results in a failure, an error
4747 * code shall be returned.
4748 *
4749 * Mandatory attributes:
4750 *
4751 * o association id - local handle to the SCTP association
4752 *
4753 * Optional attributes:
4754 *
4755 * o cause code - reason of the abort to be passed to the peer
4756 *
4757 * None.
4758 *
4759 * The return value is the disposition.
4760 */
4761sctp_disposition_t sctp_sf_do_9_1_prm_abort(
4762 const struct sctp_endpoint *ep,
4763 const struct sctp_association *asoc,
4764 const sctp_subtype_t type,
4765 void *arg,
4766 sctp_cmd_seq_t *commands)
4767{
4768 /* From 9.1 Abort of an Association
4769 * Upon receipt of the ABORT primitive from its upper
4770 * layer, the endpoint enters CLOSED state and
4771 * discard all outstanding data has been
4772 * acknowledged by its peer. The endpoint accepts no new data
4773 * from its upper layer, but retransmits data to the far end
4774 * if necessary to fill gaps.
4775 */
c164a9ba 4776 struct sctp_chunk *abort = arg;
1da177e4 4777 sctp_disposition_t retval;
b01a2407 4778 struct net *net;
1da177e4
LT
4779
4780 retval = SCTP_DISPOSITION_CONSUME;
4781
c164a9ba 4782 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
1da177e4
LT
4783
4784 /* Even if we can't send the ABORT due to low memory delete the
4785 * TCB. This is a departure from our typical NOMEM handling.
4786 */
4787
8de8c873
SS
4788 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4789 SCTP_ERROR(ECONNABORTED));
1da177e4
LT
4790 /* Delete the established association. */
4791 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5be291fe 4792 SCTP_PERR(SCTP_ERROR_USER_ABORT));
1da177e4 4793
b01a2407
EB
4794 net = sock_net(asoc->base.sk);
4795 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
4796 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
1da177e4
LT
4797
4798 return retval;
4799}
4800
4801/* We tried an illegal operation on an association which is closed. */
4802sctp_disposition_t sctp_sf_error_closed(const struct sctp_endpoint *ep,
4803 const struct sctp_association *asoc,
4804 const sctp_subtype_t type,
4805 void *arg,
4806 sctp_cmd_seq_t *commands)
4807{
4808 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, SCTP_ERROR(-EINVAL));
4809 return SCTP_DISPOSITION_CONSUME;
4810}
4811
4812/* We tried an illegal operation on an association which is shutting
4813 * down.
4814 */
4815sctp_disposition_t sctp_sf_error_shutdown(const struct sctp_endpoint *ep,
4816 const struct sctp_association *asoc,
4817 const sctp_subtype_t type,
4818 void *arg,
4819 sctp_cmd_seq_t *commands)
4820{
4821 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR,
4822 SCTP_ERROR(-ESHUTDOWN));
4823 return SCTP_DISPOSITION_CONSUME;
4824}
4825
4826/*
4827 * sctp_cookie_wait_prm_shutdown
4828 *
4829 * Section: 4 Note: 2
4830 * Verification Tag:
4831 * Inputs
4832 * (endpoint, asoc)
4833 *
4834 * The RFC does not explicitly address this issue, but is the route through the
4835 * state table when someone issues a shutdown while in COOKIE_WAIT state.
4836 *
4837 * Outputs
4838 * (timers)
4839 */
4840sctp_disposition_t sctp_sf_cookie_wait_prm_shutdown(
4841 const struct sctp_endpoint *ep,
4842 const struct sctp_association *asoc,
4843 const sctp_subtype_t type,
4844 void *arg,
4845 sctp_cmd_seq_t *commands)
4846{
b01a2407
EB
4847 struct net *net = sock_net(asoc->base.sk);
4848
1da177e4
LT
4849 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4850 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4851
4852 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4853 SCTP_STATE(SCTP_STATE_CLOSED));
4854
b01a2407 4855 SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS);
1da177e4
LT
4856
4857 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
4858
4859 return SCTP_DISPOSITION_DELETE_TCB;
4860}
4861
4862/*
4863 * sctp_cookie_echoed_prm_shutdown
4864 *
4865 * Section: 4 Note: 2
4866 * Verification Tag:
4867 * Inputs
4868 * (endpoint, asoc)
4869 *
4870 * The RFC does not explcitly address this issue, but is the route through the
4871 * state table when someone issues a shutdown while in COOKIE_ECHOED state.
4872 *
4873 * Outputs
4874 * (timers)
4875 */
4876sctp_disposition_t sctp_sf_cookie_echoed_prm_shutdown(
4877 const struct sctp_endpoint *ep,
4878 const struct sctp_association *asoc,
4879 const sctp_subtype_t type,
4880 void *arg, sctp_cmd_seq_t *commands)
4881{
4882 /* There is a single T1 timer, so we should be able to use
4883 * common function with the COOKIE-WAIT state.
4884 */
4885 return sctp_sf_cookie_wait_prm_shutdown(ep, asoc, type, arg, commands);
4886}
4887
4888/*
4889 * sctp_sf_cookie_wait_prm_abort
4890 *
4891 * Section: 4 Note: 2
4892 * Verification Tag:
4893 * Inputs
4894 * (endpoint, asoc)
4895 *
4896 * The RFC does not explicitly address this issue, but is the route through the
4897 * state table when someone issues an abort while in COOKIE_WAIT state.
4898 *
4899 * Outputs
4900 * (timers)
4901 */
4902sctp_disposition_t sctp_sf_cookie_wait_prm_abort(
4903 const struct sctp_endpoint *ep,
4904 const struct sctp_association *asoc,
4905 const sctp_subtype_t type,
4906 void *arg,
4907 sctp_cmd_seq_t *commands)
4908{
c164a9ba 4909 struct sctp_chunk *abort = arg;
1da177e4 4910 sctp_disposition_t retval;
b01a2407 4911 struct net *net = sock_net(asoc->base.sk);
1da177e4
LT
4912
4913 /* Stop T1-init timer */
4914 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4915 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4916 retval = SCTP_DISPOSITION_CONSUME;
4917
c164a9ba 4918 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
1da177e4
LT
4919
4920 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4921 SCTP_STATE(SCTP_STATE_CLOSED));
4922
b01a2407 4923 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
1da177e4
LT
4924
4925 /* Even if we can't send the ABORT due to low memory delete the
4926 * TCB. This is a departure from our typical NOMEM handling.
4927 */
4928
8de8c873
SS
4929 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4930 SCTP_ERROR(ECONNREFUSED));
1da177e4
LT
4931 /* Delete the established association. */
4932 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
dc251b2b 4933 SCTP_PERR(SCTP_ERROR_USER_ABORT));
1da177e4
LT
4934
4935 return retval;
4936}
4937
4938/*
4939 * sctp_sf_cookie_echoed_prm_abort
4940 *
4941 * Section: 4 Note: 3
4942 * Verification Tag:
4943 * Inputs
4944 * (endpoint, asoc)
4945 *
4946 * The RFC does not explcitly address this issue, but is the route through the
4947 * state table when someone issues an abort while in COOKIE_ECHOED state.
4948 *
4949 * Outputs
4950 * (timers)
4951 */
4952sctp_disposition_t sctp_sf_cookie_echoed_prm_abort(
4953 const struct sctp_endpoint *ep,
4954 const struct sctp_association *asoc,
4955 const sctp_subtype_t type,
4956 void *arg,
4957 sctp_cmd_seq_t *commands)
4958{
4959 /* There is a single T1 timer, so we should be able to use
4960 * common function with the COOKIE-WAIT state.
4961 */
4962 return sctp_sf_cookie_wait_prm_abort(ep, asoc, type, arg, commands);
4963}
4964
4965/*
4966 * sctp_sf_shutdown_pending_prm_abort
4967 *
4968 * Inputs
4969 * (endpoint, asoc)
4970 *
4971 * The RFC does not explicitly address this issue, but is the route through the
4972 * state table when someone issues an abort while in SHUTDOWN-PENDING state.
4973 *
4974 * Outputs
4975 * (timers)
4976 */
4977sctp_disposition_t sctp_sf_shutdown_pending_prm_abort(
4978 const struct sctp_endpoint *ep,
4979 const struct sctp_association *asoc,
4980 const sctp_subtype_t type,
4981 void *arg,
4982 sctp_cmd_seq_t *commands)
4983{
4984 /* Stop the T5-shutdown guard timer. */
4985 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4986 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4987
4988 return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands);
4989}
4990
4991/*
4992 * sctp_sf_shutdown_sent_prm_abort
4993 *
4994 * Inputs
4995 * (endpoint, asoc)
4996 *
4997 * The RFC does not explicitly address this issue, but is the route through the
4998 * state table when someone issues an abort while in SHUTDOWN-SENT state.
4999 *
5000 * Outputs
5001 * (timers)
5002 */
5003sctp_disposition_t sctp_sf_shutdown_sent_prm_abort(
5004 const struct sctp_endpoint *ep,
5005 const struct sctp_association *asoc,
5006 const sctp_subtype_t type,
5007 void *arg,
5008 sctp_cmd_seq_t *commands)
5009{
5010 /* Stop the T2-shutdown timer. */
5011 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5012 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5013
5014 /* Stop the T5-shutdown guard timer. */
5015 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5016 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5017
5018 return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands);
5019}
5020
5021/*
5022 * sctp_sf_cookie_echoed_prm_abort
5023 *
5024 * Inputs
5025 * (endpoint, asoc)
5026 *
5027 * The RFC does not explcitly address this issue, but is the route through the
5028 * state table when someone issues an abort while in COOKIE_ECHOED state.
5029 *
5030 * Outputs
5031 * (timers)
5032 */
5033sctp_disposition_t sctp_sf_shutdown_ack_sent_prm_abort(
5034 const struct sctp_endpoint *ep,
5035 const struct sctp_association *asoc,
5036 const sctp_subtype_t type,
5037 void *arg,
5038 sctp_cmd_seq_t *commands)
5039{
5040 /* The same T2 timer, so we should be able to use
5041 * common function with the SHUTDOWN-SENT state.
5042 */
5043 return sctp_sf_shutdown_sent_prm_abort(ep, asoc, type, arg, commands);
5044}
5045
5046/*
5047 * Process the REQUESTHEARTBEAT primitive
5048 *
5049 * 10.1 ULP-to-SCTP
5050 * J) Request Heartbeat
5051 *
5052 * Format: REQUESTHEARTBEAT(association id, destination transport address)
5053 *
5054 * -> result
5055 *
5056 * Instructs the local endpoint to perform a HeartBeat on the specified
5057 * destination transport address of the given association. The returned
5058 * result should indicate whether the transmission of the HEARTBEAT
5059 * chunk to the destination address is successful.
5060 *
5061 * Mandatory attributes:
5062 *
5063 * o association id - local handle to the SCTP association
5064 *
5065 * o destination transport address - the transport address of the
5066 * association on which a heartbeat should be issued.
5067 */
5068sctp_disposition_t sctp_sf_do_prm_requestheartbeat(
5069 const struct sctp_endpoint *ep,
5070 const struct sctp_association *asoc,
5071 const sctp_subtype_t type,
5072 void *arg,
5073 sctp_cmd_seq_t *commands)
5074{
fb78525a
VY
5075 if (SCTP_DISPOSITION_NOMEM == sctp_sf_heartbeat(ep, asoc, type,
5076 (struct sctp_transport *)arg, commands))
5077 return SCTP_DISPOSITION_NOMEM;
5078
5079 /*
5080 * RFC 2960 (bis), section 8.3
5081 *
5082 * D) Request an on-demand HEARTBEAT on a specific destination
5083 * transport address of a given association.
5084 *
5085 * The endpoint should increment the respective error counter of
5086 * the destination transport address each time a HEARTBEAT is sent
5087 * to that address and not acknowledged within one RTO.
5088 *
5089 */
7e99013a 5090 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_HB_SENT,
fb78525a
VY
5091 SCTP_TRANSPORT(arg));
5092 return SCTP_DISPOSITION_CONSUME;
1da177e4
LT
5093}
5094
5095/*
5096 * ADDIP Section 4.1 ASCONF Chunk Procedures
5097 * When an endpoint has an ASCONF signaled change to be sent to the
5098 * remote endpoint it should do A1 to A9
5099 */
5100sctp_disposition_t sctp_sf_do_prm_asconf(const struct sctp_endpoint *ep,
5101 const struct sctp_association *asoc,
5102 const sctp_subtype_t type,
5103 void *arg,
5104 sctp_cmd_seq_t *commands)
5105{
5106 struct sctp_chunk *chunk = arg;
5107
5108 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
5109 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
5110 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
5111 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
5112 return SCTP_DISPOSITION_CONSUME;
5113}
5114
5115/*
5116 * Ignore the primitive event
5117 *
5118 * The return value is the disposition of the primitive.
5119 */
5120sctp_disposition_t sctp_sf_ignore_primitive(
5121 const struct sctp_endpoint *ep,
5122 const struct sctp_association *asoc,
5123 const sctp_subtype_t type,
5124 void *arg,
5125 sctp_cmd_seq_t *commands)
5126{
5127 SCTP_DEBUG_PRINTK("Primitive type %d is ignored.\n", type.primitive);
5128 return SCTP_DISPOSITION_DISCARD;
5129}
5130
5131/***************************************************************************
5132 * These are the state functions for the OTHER events.
5133 ***************************************************************************/
5134
e1cdd553
WY
5135/*
5136 * When the SCTP stack has no more user data to send or retransmit, this
5137 * notification is given to the user. Also, at the time when a user app
5138 * subscribes to this event, if there is no data to be sent or
5139 * retransmit, the stack will immediately send up this notification.
5140 */
5141sctp_disposition_t sctp_sf_do_no_pending_tsn(
5142 const struct sctp_endpoint *ep,
5143 const struct sctp_association *asoc,
5144 const sctp_subtype_t type,
5145 void *arg,
5146 sctp_cmd_seq_t *commands)
5147{
5148 struct sctp_ulpevent *event;
5149
5150 event = sctp_ulpevent_make_sender_dry_event(asoc, GFP_ATOMIC);
5151 if (!event)
5152 return SCTP_DISPOSITION_NOMEM;
5153
5154 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(event));
5155
5156 return SCTP_DISPOSITION_CONSUME;
5157}
5158
1da177e4
LT
5159/*
5160 * Start the shutdown negotiation.
5161 *
5162 * From Section 9.2:
5163 * Once all its outstanding data has been acknowledged, the endpoint
5164 * shall send a SHUTDOWN chunk to its peer including in the Cumulative
5165 * TSN Ack field the last sequential TSN it has received from the peer.
5166 * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT
5167 * state. If the timer expires, the endpoint must re-send the SHUTDOWN
5168 * with the updated last sequential TSN received from its peer.
5169 *
5170 * The return value is the disposition.
5171 */
5172sctp_disposition_t sctp_sf_do_9_2_start_shutdown(
5173 const struct sctp_endpoint *ep,
5174 const struct sctp_association *asoc,
5175 const sctp_subtype_t type,
5176 void *arg,
5177 sctp_cmd_seq_t *commands)
5178{
5179 struct sctp_chunk *reply;
5180
5181 /* Once all its outstanding data has been acknowledged, the
5182 * endpoint shall send a SHUTDOWN chunk to its peer including
5183 * in the Cumulative TSN Ack field the last sequential TSN it
5184 * has received from the peer.
5185 */
5186 reply = sctp_make_shutdown(asoc, NULL);
5187 if (!reply)
5188 goto nomem;
5189
5190 /* Set the transport for the SHUTDOWN chunk and the timeout for the
5191 * T2-shutdown timer.
5192 */
5193 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5194
5195 /* It shall then start the T2-shutdown timer */
5196 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
5197 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5198
536428a9
WY
5199 /* RFC 4960 Section 9.2
5200 * The sender of the SHUTDOWN MAY also start an overall guard timer
5201 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5202 */
f8d96052 5203 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
536428a9
WY
5204 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5205
1da177e4
LT
5206 if (asoc->autoclose)
5207 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5208 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
5209
5210 /* and enter the SHUTDOWN-SENT state. */
5211 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5212 SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT));
5213
5214 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5215 *
5216 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
d808ad9a 5217 * or SHUTDOWN-ACK.
1da177e4
LT
5218 */
5219 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
5220
5221 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5222
5223 return SCTP_DISPOSITION_CONSUME;
5224
5225nomem:
5226 return SCTP_DISPOSITION_NOMEM;
5227}
5228
5229/*
5230 * Generate a SHUTDOWN ACK now that everything is SACK'd.
5231 *
5232 * From Section 9.2:
5233 *
5234 * If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5235 * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own,
5236 * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the
5237 * endpoint must re-send the SHUTDOWN ACK.
5238 *
5239 * The return value is the disposition.
5240 */
5241sctp_disposition_t sctp_sf_do_9_2_shutdown_ack(
5242 const struct sctp_endpoint *ep,
5243 const struct sctp_association *asoc,
5244 const sctp_subtype_t type,
5245 void *arg,
5246 sctp_cmd_seq_t *commands)
5247{
5248 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
5249 struct sctp_chunk *reply;
5250
5251 /* There are 2 ways of getting here:
5252 * 1) called in response to a SHUTDOWN chunk
5253 * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued.
5254 *
5255 * For the case (2), the arg parameter is set to NULL. We need
5256 * to check that we have a chunk before accessing it's fields.
5257 */
5258 if (chunk) {
5259 if (!sctp_vtag_verify(chunk, asoc))
5260 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
5261
5262 /* Make sure that the SHUTDOWN chunk has a valid length. */
5263 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_shutdown_chunk_t)))
5264 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
5265 commands);
5266 }
5267
5268 /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5269 * shall send a SHUTDOWN ACK ...
5270 */
5271 reply = sctp_make_shutdown_ack(asoc, chunk);
5272 if (!reply)
5273 goto nomem;
5274
5275 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
5276 * the T2-shutdown timer.
5277 */
5278 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5279
5280 /* and start/restart a T2-shutdown timer of its own, */
5281 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5282 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5283
5284 if (asoc->autoclose)
5285 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5286 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
5287
5288 /* Enter the SHUTDOWN-ACK-SENT state. */
5289 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5290 SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT));
5291
5292 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5293 *
5294 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
d808ad9a 5295 * or SHUTDOWN-ACK.
1da177e4
LT
5296 */
5297 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
5298
5299 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5300
5301 return SCTP_DISPOSITION_CONSUME;
5302
5303nomem:
5304 return SCTP_DISPOSITION_NOMEM;
5305}
5306
5307/*
5308 * Ignore the event defined as other
5309 *
5310 * The return value is the disposition of the event.
5311 */
5312sctp_disposition_t sctp_sf_ignore_other(const struct sctp_endpoint *ep,
5313 const struct sctp_association *asoc,
5314 const sctp_subtype_t type,
5315 void *arg,
5316 sctp_cmd_seq_t *commands)
5317{
5318 SCTP_DEBUG_PRINTK("The event other type %d is ignored\n", type.other);
5319 return SCTP_DISPOSITION_DISCARD;
5320}
5321
5322/************************************************************
5323 * These are the state functions for handling timeout events.
5324 ************************************************************/
5325
5326/*
5327 * RTX Timeout
5328 *
5329 * Section: 6.3.3 Handle T3-rtx Expiration
5330 *
5331 * Whenever the retransmission timer T3-rtx expires for a destination
5332 * address, do the following:
5333 * [See below]
5334 *
5335 * The return value is the disposition of the chunk.
5336 */
5337sctp_disposition_t sctp_sf_do_6_3_3_rtx(const struct sctp_endpoint *ep,
5338 const struct sctp_association *asoc,
5339 const sctp_subtype_t type,
5340 void *arg,
5341 sctp_cmd_seq_t *commands)
5342{
5343 struct sctp_transport *transport = arg;
b01a2407 5344 struct net *net = sock_net(asoc->base.sk);
1da177e4 5345
b01a2407 5346 SCTP_INC_STATS(net, SCTP_MIB_T3_RTX_EXPIREDS);
ac0b0462 5347
1da177e4 5348 if (asoc->overall_error_count >= asoc->max_retrans) {
f8d96052
TG
5349 if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING) {
5350 /*
5351 * We are here likely because the receiver had its rwnd
5352 * closed for a while and we have not been able to
5353 * transmit the locally queued data within the maximum
5354 * retransmission attempts limit. Start the T5
5355 * shutdown guard timer to give the receiver one last
5356 * chance and some additional time to recover before
5357 * aborting.
5358 */
5359 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START_ONCE,
5360 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5361 } else {
5362 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5363 SCTP_ERROR(ETIMEDOUT));
5364 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5365 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5366 SCTP_PERR(SCTP_ERROR_NO_ERROR));
b01a2407
EB
5367 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5368 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
f8d96052
TG
5369 return SCTP_DISPOSITION_DELETE_TCB;
5370 }
1da177e4
LT
5371 }
5372
5373 /* E1) For the destination address for which the timer
5374 * expires, adjust its ssthresh with rules defined in Section
5375 * 7.2.3 and set the cwnd <- MTU.
5376 */
5377
5378 /* E2) For the destination address for which the timer
5379 * expires, set RTO <- RTO * 2 ("back off the timer"). The
5380 * maximum value discussed in rule C7 above (RTO.max) may be
5381 * used to provide an upper bound to this doubling operation.
5382 */
5383
5384 /* E3) Determine how many of the earliest (i.e., lowest TSN)
5385 * outstanding DATA chunks for the address for which the
5386 * T3-rtx has expired will fit into a single packet, subject
5387 * to the MTU constraint for the path corresponding to the
5388 * destination transport address to which the retransmission
5389 * is being sent (this may be different from the address for
5390 * which the timer expires [see Section 6.4]). Call this
5391 * value K. Bundle and retransmit those K DATA chunks in a
5392 * single packet to the destination endpoint.
5393 *
5394 * Note: Any DATA chunks that were sent to the address for
5395 * which the T3-rtx timer expired but did not fit in one MTU
5396 * (rule E3 above), should be marked for retransmission and
5397 * sent as soon as cwnd allows (normally when a SACK arrives).
5398 */
5399
1da177e4
LT
5400 /* Do some failure management (Section 8.2). */
5401 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
5402
1845a579
VY
5403 /* NB: Rules E4 and F1 are implicit in R1. */
5404 sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN, SCTP_TRANSPORT(transport));
5405
1da177e4
LT
5406 return SCTP_DISPOSITION_CONSUME;
5407}
5408
5409/*
5410 * Generate delayed SACK on timeout
5411 *
5412 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
5413 *
5414 * The guidelines on delayed acknowledgement algorithm specified in
5415 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
5416 * acknowledgement SHOULD be generated for at least every second packet
5417 * (not every second DATA chunk) received, and SHOULD be generated
5418 * within 200 ms of the arrival of any unacknowledged DATA chunk. In
5419 * some situations it may be beneficial for an SCTP transmitter to be
5420 * more conservative than the algorithms detailed in this document
5421 * allow. However, an SCTP transmitter MUST NOT be more aggressive than
5422 * the following algorithms allow.
5423 */
5424sctp_disposition_t sctp_sf_do_6_2_sack(const struct sctp_endpoint *ep,
5425 const struct sctp_association *asoc,
5426 const sctp_subtype_t type,
5427 void *arg,
5428 sctp_cmd_seq_t *commands)
5429{
b01a2407
EB
5430 struct net *net = sock_net(asoc->base.sk);
5431 SCTP_INC_STATS(net, SCTP_MIB_DELAY_SACK_EXPIREDS);
1da177e4
LT
5432 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
5433 return SCTP_DISPOSITION_CONSUME;
5434}
5435
5436/*
3f7a87d2 5437 * sctp_sf_t1_init_timer_expire
1da177e4
LT
5438 *
5439 * Section: 4 Note: 2
5440 * Verification Tag:
5441 * Inputs
5442 * (endpoint, asoc)
5443 *
5444 * RFC 2960 Section 4 Notes
5445 * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT
5446 * and re-start the T1-init timer without changing state. This MUST
5447 * be repeated up to 'Max.Init.Retransmits' times. After that, the
5448 * endpoint MUST abort the initialization process and report the
5449 * error to SCTP user.
5450 *
3f7a87d2
FF
5451 * Outputs
5452 * (timers, events)
5453 *
5454 */
5455sctp_disposition_t sctp_sf_t1_init_timer_expire(const struct sctp_endpoint *ep,
5456 const struct sctp_association *asoc,
5457 const sctp_subtype_t type,
5458 void *arg,
5459 sctp_cmd_seq_t *commands)
5460{
5461 struct sctp_chunk *repl = NULL;
5462 struct sctp_bind_addr *bp;
5463 int attempts = asoc->init_err_counter + 1;
b01a2407 5464 struct net *net = sock_net(asoc->base.sk);
3f7a87d2
FF
5465
5466 SCTP_DEBUG_PRINTK("Timer T1 expired (INIT).\n");
b01a2407 5467 SCTP_INC_STATS(net, SCTP_MIB_T1_INIT_EXPIREDS);
3f7a87d2 5468
81845c21 5469 if (attempts <= asoc->max_init_attempts) {
3f7a87d2
FF
5470 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
5471 repl = sctp_make_init(asoc, bp, GFP_ATOMIC, 0);
5472 if (!repl)
5473 return SCTP_DISPOSITION_NOMEM;
5474
5475 /* Choose transport for INIT. */
5476 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
5477 SCTP_CHUNK(repl));
5478
5479 /* Issue a sideeffect to do the needed accounting. */
5480 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_RESTART,
5481 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
5482
5483 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
5484 } else {
5485 SCTP_DEBUG_PRINTK("Giving up on INIT, attempts: %d"
5486 " max_init_attempts: %d\n",
5487 attempts, asoc->max_init_attempts);
8de8c873
SS
5488 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5489 SCTP_ERROR(ETIMEDOUT));
3f7a87d2 5490 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
dc251b2b 5491 SCTP_PERR(SCTP_ERROR_NO_ERROR));
3f7a87d2
FF
5492 return SCTP_DISPOSITION_DELETE_TCB;
5493 }
5494
5495 return SCTP_DISPOSITION_CONSUME;
5496}
5497
5498/*
5499 * sctp_sf_t1_cookie_timer_expire
5500 *
5501 * Section: 4 Note: 2
5502 * Verification Tag:
5503 * Inputs
5504 * (endpoint, asoc)
5505 *
5506 * RFC 2960 Section 4 Notes
5507 * 3) If the T1-cookie timer expires, the endpoint MUST retransmit
1da177e4
LT
5508 * COOKIE ECHO and re-start the T1-cookie timer without changing
5509 * state. This MUST be repeated up to 'Max.Init.Retransmits' times.
5510 * After that, the endpoint MUST abort the initialization process and
5511 * report the error to SCTP user.
5512 *
5513 * Outputs
5514 * (timers, events)
5515 *
5516 */
3f7a87d2 5517sctp_disposition_t sctp_sf_t1_cookie_timer_expire(const struct sctp_endpoint *ep,
1da177e4
LT
5518 const struct sctp_association *asoc,
5519 const sctp_subtype_t type,
5520 void *arg,
5521 sctp_cmd_seq_t *commands)
5522{
3f7a87d2
FF
5523 struct sctp_chunk *repl = NULL;
5524 int attempts = asoc->init_err_counter + 1;
b01a2407 5525 struct net *net = sock_net(asoc->base.sk);
1da177e4 5526
3f7a87d2 5527 SCTP_DEBUG_PRINTK("Timer T1 expired (COOKIE-ECHO).\n");
b01a2407 5528 SCTP_INC_STATS(net, SCTP_MIB_T1_COOKIE_EXPIREDS);
1da177e4 5529
81845c21 5530 if (attempts <= asoc->max_init_attempts) {
3f7a87d2 5531 repl = sctp_make_cookie_echo(asoc, NULL);
1da177e4 5532 if (!repl)
3f7a87d2 5533 return SCTP_DISPOSITION_NOMEM;
1da177e4 5534
96cd0d3d
VY
5535 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
5536 SCTP_CHUNK(repl));
1da177e4 5537 /* Issue a sideeffect to do the needed accounting. */
3f7a87d2
FF
5538 sctp_add_cmd_sf(commands, SCTP_CMD_COOKIEECHO_RESTART,
5539 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
5540
1da177e4
LT
5541 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
5542 } else {
8de8c873
SS
5543 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5544 SCTP_ERROR(ETIMEDOUT));
1da177e4 5545 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
dc251b2b 5546 SCTP_PERR(SCTP_ERROR_NO_ERROR));
1da177e4
LT
5547 return SCTP_DISPOSITION_DELETE_TCB;
5548 }
5549
5550 return SCTP_DISPOSITION_CONSUME;
1da177e4
LT
5551}
5552
5553/* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN
5554 * with the updated last sequential TSN received from its peer.
5555 *
5556 * An endpoint should limit the number of retransmissions of the
5557 * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'.
5558 * If this threshold is exceeded the endpoint should destroy the TCB and
5559 * MUST report the peer endpoint unreachable to the upper layer (and
5560 * thus the association enters the CLOSED state). The reception of any
5561 * packet from its peer (i.e. as the peer sends all of its queued DATA
5562 * chunks) should clear the endpoint's retransmission count and restart
5563 * the T2-Shutdown timer, giving its peer ample opportunity to transmit
5564 * all of its queued DATA chunks that have not yet been sent.
5565 */
5566sctp_disposition_t sctp_sf_t2_timer_expire(const struct sctp_endpoint *ep,
5567 const struct sctp_association *asoc,
5568 const sctp_subtype_t type,
5569 void *arg,
5570 sctp_cmd_seq_t *commands)
5571{
5572 struct sctp_chunk *reply = NULL;
b01a2407 5573 struct net *net = sock_net(asoc->base.sk);
1da177e4
LT
5574
5575 SCTP_DEBUG_PRINTK("Timer T2 expired.\n");
b01a2407 5576 SCTP_INC_STATS(net, SCTP_MIB_T2_SHUTDOWN_EXPIREDS);
ac0b0462 5577
58fbbed4
NH
5578 ((struct sctp_association *)asoc)->shutdown_retries++;
5579
1da177e4 5580 if (asoc->overall_error_count >= asoc->max_retrans) {
8de8c873
SS
5581 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5582 SCTP_ERROR(ETIMEDOUT));
1da177e4
LT
5583 /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5584 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5be291fe 5585 SCTP_PERR(SCTP_ERROR_NO_ERROR));
b01a2407
EB
5586 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5587 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
1da177e4
LT
5588 return SCTP_DISPOSITION_DELETE_TCB;
5589 }
5590
5591 switch (asoc->state) {
5592 case SCTP_STATE_SHUTDOWN_SENT:
5593 reply = sctp_make_shutdown(asoc, NULL);
5594 break;
5595
5596 case SCTP_STATE_SHUTDOWN_ACK_SENT:
5597 reply = sctp_make_shutdown_ack(asoc, NULL);
5598 break;
5599
5600 default:
5601 BUG();
5602 break;
3ff50b79 5603 }
1da177e4
LT
5604
5605 if (!reply)
5606 goto nomem;
5607
6345b199
WY
5608 /* Do some failure management (Section 8.2).
5609 * If we remove the transport an SHUTDOWN was last sent to, don't
5610 * do failure management.
5611 */
5612 if (asoc->shutdown_last_sent_to)
5613 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
5614 SCTP_TRANSPORT(asoc->shutdown_last_sent_to));
1da177e4
LT
5615
5616 /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for
5617 * the T2-shutdown timer.
5618 */
5619 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5620
5621 /* Restart the T2-shutdown timer. */
5622 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5623 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5624 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5625 return SCTP_DISPOSITION_CONSUME;
5626
5627nomem:
5628 return SCTP_DISPOSITION_NOMEM;
5629}
5630
5631/*
5632 * ADDIP Section 4.1 ASCONF CHunk Procedures
5633 * If the T4 RTO timer expires the endpoint should do B1 to B5
5634 */
5635sctp_disposition_t sctp_sf_t4_timer_expire(
5636 const struct sctp_endpoint *ep,
5637 const struct sctp_association *asoc,
5638 const sctp_subtype_t type,
5639 void *arg,
5640 sctp_cmd_seq_t *commands)
5641{
5642 struct sctp_chunk *chunk = asoc->addip_last_asconf;
5643 struct sctp_transport *transport = chunk->transport;
b01a2407 5644 struct net *net = sock_net(asoc->base.sk);
1da177e4 5645
b01a2407 5646 SCTP_INC_STATS(net, SCTP_MIB_T4_RTO_EXPIREDS);
ac0b0462 5647
1da177e4
LT
5648 /* ADDIP 4.1 B1) Increment the error counters and perform path failure
5649 * detection on the appropriate destination address as defined in
5650 * RFC2960 [5] section 8.1 and 8.2.
5651 */
10a43cea
WY
5652 if (transport)
5653 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
5654 SCTP_TRANSPORT(transport));
1da177e4
LT
5655
5656 /* Reconfig T4 timer and transport. */
5657 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
5658
5659 /* ADDIP 4.1 B2) Increment the association error counters and perform
5660 * endpoint failure detection on the association as defined in
5661 * RFC2960 [5] section 8.1 and 8.2.
5662 * association error counter is incremented in SCTP_CMD_STRIKE.
5663 */
5664 if (asoc->overall_error_count >= asoc->max_retrans) {
5665 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5666 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
8de8c873
SS
5667 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5668 SCTP_ERROR(ETIMEDOUT));
1da177e4 5669 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5be291fe 5670 SCTP_PERR(SCTP_ERROR_NO_ERROR));
b01a2407
EB
5671 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5672 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
1da177e4
LT
5673 return SCTP_DISPOSITION_ABORT;
5674 }
5675
5676 /* ADDIP 4.1 B3) Back-off the destination address RTO value to which
5677 * the ASCONF chunk was sent by doubling the RTO timer value.
5678 * This is done in SCTP_CMD_STRIKE.
5679 */
5680
5681 /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible
5682 * choose an alternate destination address (please refer to RFC2960
5683 * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this
d808ad9a 5684 * chunk, it MUST be the same (including its serial number) as the last
1da177e4
LT
5685 * ASCONF sent.
5686 */
5687 sctp_chunk_hold(asoc->addip_last_asconf);
5688 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
5689 SCTP_CHUNK(asoc->addip_last_asconf));
5690
5691 /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different
5692 * destination is selected, then the RTO used will be that of the new
5693 * destination address.
5694 */
5695 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5696 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
5697
5698 return SCTP_DISPOSITION_CONSUME;
5699}
5700
5701/* sctpimpguide-05 Section 2.12.2
5702 * The sender of the SHUTDOWN MAY also start an overall guard timer
5703 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5704 * At the expiration of this timer the sender SHOULD abort the association
5705 * by sending an ABORT chunk.
5706 */
5707sctp_disposition_t sctp_sf_t5_timer_expire(const struct sctp_endpoint *ep,
5708 const struct sctp_association *asoc,
5709 const sctp_subtype_t type,
5710 void *arg,
5711 sctp_cmd_seq_t *commands)
5712{
5713 struct sctp_chunk *reply = NULL;
b01a2407 5714 struct net *net = sock_net(asoc->base.sk);
1da177e4
LT
5715
5716 SCTP_DEBUG_PRINTK("Timer T5 expired.\n");
b01a2407 5717 SCTP_INC_STATS(net, SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS);
1da177e4
LT
5718
5719 reply = sctp_make_abort(asoc, NULL, 0);
5720 if (!reply)
5721 goto nomem;
5722
5723 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
8de8c873
SS
5724 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5725 SCTP_ERROR(ETIMEDOUT));
1da177e4 5726 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5be291fe 5727 SCTP_PERR(SCTP_ERROR_NO_ERROR));
1da177e4 5728
b01a2407
EB
5729 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5730 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
a1080a8b 5731
1da177e4
LT
5732 return SCTP_DISPOSITION_DELETE_TCB;
5733nomem:
5734 return SCTP_DISPOSITION_NOMEM;
5735}
5736
5737/* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires,
5738 * the association is automatically closed by starting the shutdown process.
5739 * The work that needs to be done is same as when SHUTDOWN is initiated by
5740 * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown().
5741 */
5742sctp_disposition_t sctp_sf_autoclose_timer_expire(
5743 const struct sctp_endpoint *ep,
5744 const struct sctp_association *asoc,
5745 const sctp_subtype_t type,
5746 void *arg,
5747 sctp_cmd_seq_t *commands)
5748{
b01a2407 5749 struct net *net = sock_net(asoc->base.sk);
1da177e4
LT
5750 int disposition;
5751
b01a2407 5752 SCTP_INC_STATS(net, SCTP_MIB_AUTOCLOSE_EXPIREDS);
ac0b0462 5753
1da177e4
LT
5754 /* From 9.2 Shutdown of an Association
5755 * Upon receipt of the SHUTDOWN primitive from its upper
5756 * layer, the endpoint enters SHUTDOWN-PENDING state and
5757 * remains there until all outstanding data has been
5758 * acknowledged by its peer. The endpoint accepts no new data
5759 * from its upper layer, but retransmits data to the far end
5760 * if necessary to fill gaps.
5761 */
5762 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5763 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
5764
1da177e4
LT
5765 disposition = SCTP_DISPOSITION_CONSUME;
5766 if (sctp_outq_is_empty(&asoc->outqueue)) {
5767 disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type,
5768 arg, commands);
5769 }
5770 return disposition;
5771}
5772
5773/*****************************************************************************
5774 * These are sa state functions which could apply to all types of events.
5775 ****************************************************************************/
5776
5777/*
5778 * This table entry is not implemented.
5779 *
5780 * Inputs
5781 * (endpoint, asoc, chunk)
5782 *
5783 * The return value is the disposition of the chunk.
5784 */
5785sctp_disposition_t sctp_sf_not_impl(const struct sctp_endpoint *ep,
5786 const struct sctp_association *asoc,
5787 const sctp_subtype_t type,
5788 void *arg,
5789 sctp_cmd_seq_t *commands)
5790{
5791 return SCTP_DISPOSITION_NOT_IMPL;
5792}
5793
5794/*
5795 * This table entry represents a bug.
5796 *
5797 * Inputs
5798 * (endpoint, asoc, chunk)
5799 *
5800 * The return value is the disposition of the chunk.
5801 */
5802sctp_disposition_t sctp_sf_bug(const struct sctp_endpoint *ep,
5803 const struct sctp_association *asoc,
5804 const sctp_subtype_t type,
5805 void *arg,
5806 sctp_cmd_seq_t *commands)
5807{
5808 return SCTP_DISPOSITION_BUG;
5809}
5810
5811/*
5812 * This table entry represents the firing of a timer in the wrong state.
5813 * Since timer deletion cannot be guaranteed a timer 'may' end up firing
5814 * when the association is in the wrong state. This event should
5815 * be ignored, so as to prevent any rearming of the timer.
5816 *
5817 * Inputs
5818 * (endpoint, asoc, chunk)
5819 *
5820 * The return value is the disposition of the chunk.
5821 */
5822sctp_disposition_t sctp_sf_timer_ignore(const struct sctp_endpoint *ep,
5823 const struct sctp_association *asoc,
5824 const sctp_subtype_t type,
5825 void *arg,
5826 sctp_cmd_seq_t *commands)
5827{
5828 SCTP_DEBUG_PRINTK("Timer %d ignored.\n", type.chunk);
5829 return SCTP_DISPOSITION_CONSUME;
5830}
5831
5832/********************************************************************
5833 * 2nd Level Abstractions
5834 ********************************************************************/
5835
5836/* Pull the SACK chunk based on the SACK header. */
5837static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk)
5838{
5839 struct sctp_sackhdr *sack;
5840 unsigned int len;
5841 __u16 num_blocks;
5842 __u16 num_dup_tsns;
5843
5844 /* Protect ourselves from reading too far into
5845 * the skb from a bogus sender.
5846 */
5847 sack = (struct sctp_sackhdr *) chunk->skb->data;
5848
5849 num_blocks = ntohs(sack->num_gap_ack_blocks);
5850 num_dup_tsns = ntohs(sack->num_dup_tsns);
5851 len = sizeof(struct sctp_sackhdr);
5852 len += (num_blocks + num_dup_tsns) * sizeof(__u32);
5853 if (len > chunk->skb->len)
5854 return NULL;
5855
5856 skb_pull(chunk->skb, len);
5857
5858 return sack;
5859}
5860
5861/* Create an ABORT packet to be sent as a response, with the specified
5862 * error causes.
5863 */
5864static struct sctp_packet *sctp_abort_pkt_new(const struct sctp_endpoint *ep,
5865 const struct sctp_association *asoc,
5866 struct sctp_chunk *chunk,
5867 const void *payload,
5868 size_t paylen)
5869{
5870 struct sctp_packet *packet;
5871 struct sctp_chunk *abort;
2ce95503 5872 struct net *net;
1da177e4 5873
2ce95503
EB
5874 net = sock_net(ep->base.sk);
5875 packet = sctp_ootb_pkt_new(net, asoc, chunk);
1da177e4
LT
5876
5877 if (packet) {
5878 /* Make an ABORT.
5879 * The T bit will be set if the asoc is NULL.
5880 */
5881 abort = sctp_make_abort(asoc, chunk, paylen);
5882 if (!abort) {
5883 sctp_ootb_pkt_free(packet);
5884 return NULL;
5885 }
047a2428
JF
5886
5887 /* Reflect vtag if T-Bit is set */
5888 if (sctp_test_T_bit(abort))
5889 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
5890
1da177e4
LT
5891 /* Add specified error causes, i.e., payload, to the
5892 * end of the chunk.
5893 */
5894 sctp_addto_chunk(abort, paylen, payload);
5895
5896 /* Set the skb to the belonging sock for accounting. */
5897 abort->skb->sk = ep->base.sk;
5898
5899 sctp_packet_append_chunk(packet, abort);
5900
5901 }
5902
5903 return packet;
5904}
5905
5906/* Allocate a packet for responding in the OOTB conditions. */
2ce95503
EB
5907static struct sctp_packet *sctp_ootb_pkt_new(struct net *net,
5908 const struct sctp_association *asoc,
1da177e4
LT
5909 const struct sctp_chunk *chunk)
5910{
5911 struct sctp_packet *packet;
5912 struct sctp_transport *transport;
5913 __u16 sport;
5914 __u16 dport;
5915 __u32 vtag;
5916
5917 /* Get the source and destination port from the inbound packet. */
5918 sport = ntohs(chunk->sctp_hdr->dest);
5919 dport = ntohs(chunk->sctp_hdr->source);
5920
5921 /* The V-tag is going to be the same as the inbound packet if no
5922 * association exists, otherwise, use the peer's vtag.
5923 */
5924 if (asoc) {
02c4e12c
WY
5925 /* Special case the INIT-ACK as there is no peer's vtag
5926 * yet.
5927 */
5928 switch(chunk->chunk_hdr->type) {
5929 case SCTP_CID_INIT_ACK:
5930 {
5931 sctp_initack_chunk_t *initack;
5932
5933 initack = (sctp_initack_chunk_t *)chunk->chunk_hdr;
5934 vtag = ntohl(initack->init_hdr.init_tag);
5935 break;
5936 }
5937 default:
5938 vtag = asoc->peer.i.init_tag;
5939 break;
5940 }
1da177e4
LT
5941 } else {
5942 /* Special case the INIT and stale COOKIE_ECHO as there is no
5943 * vtag yet.
5944 */
5945 switch(chunk->chunk_hdr->type) {
5946 case SCTP_CID_INIT:
5947 {
5948 sctp_init_chunk_t *init;
5949
5950 init = (sctp_init_chunk_t *)chunk->chunk_hdr;
5951 vtag = ntohl(init->init_hdr.init_tag);
5952 break;
5953 }
d808ad9a 5954 default:
1da177e4
LT
5955 vtag = ntohl(chunk->sctp_hdr->vtag);
5956 break;
5957 }
5958 }
5959
5960 /* Make a transport for the bucket, Eliza... */
89bf3450 5961 transport = sctp_transport_new(net, sctp_source(chunk), GFP_ATOMIC);
1da177e4
LT
5962 if (!transport)
5963 goto nomem;
5964
5965 /* Cache a route for the transport with the chunk's destination as
5966 * the source address.
5967 */
16b0a030 5968 sctp_transport_route(transport, (union sctp_addr *)&chunk->dest,
2ce95503 5969 sctp_sk(net->sctp.ctl_sock));
1da177e4
LT
5970
5971 packet = sctp_packet_init(&transport->packet, transport, sport, dport);
5972 packet = sctp_packet_config(packet, vtag, 0);
5973
5974 return packet;
5975
5976nomem:
5977 return NULL;
5978}
5979
5980/* Free the packet allocated earlier for responding in the OOTB condition. */
5981void sctp_ootb_pkt_free(struct sctp_packet *packet)
5982{
5983 sctp_transport_free(packet->transport);
5984}
5985
5986/* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */
5987static void sctp_send_stale_cookie_err(const struct sctp_endpoint *ep,
5988 const struct sctp_association *asoc,
5989 const struct sctp_chunk *chunk,
5990 sctp_cmd_seq_t *commands,
5991 struct sctp_chunk *err_chunk)
5992{
5993 struct sctp_packet *packet;
5994
5995 if (err_chunk) {
2ce95503
EB
5996 struct net *net = sock_net(ep->base.sk);
5997 packet = sctp_ootb_pkt_new(net, asoc, chunk);
1da177e4
LT
5998 if (packet) {
5999 struct sctp_signed_cookie *cookie;
6000
6001 /* Override the OOTB vtag from the cookie. */
6002 cookie = chunk->subh.cookie_hdr;
6003 packet->vtag = cookie->c.peer_vtag;
d808ad9a 6004
1da177e4
LT
6005 /* Set the skb to the belonging sock for accounting. */
6006 err_chunk->skb->sk = ep->base.sk;
6007 sctp_packet_append_chunk(packet, err_chunk);
6008 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
6009 SCTP_PACKET(packet));
b01a2407 6010 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
1da177e4
LT
6011 } else
6012 sctp_chunk_free (err_chunk);
6013 }
6014}
6015
6016
6017/* Process a data chunk */
6018static int sctp_eat_data(const struct sctp_association *asoc,
6019 struct sctp_chunk *chunk,
6020 sctp_cmd_seq_t *commands)
6021{
6022 sctp_datahdr_t *data_hdr;
6023 struct sctp_chunk *err;
6024 size_t datalen;
6025 sctp_verb_t deliver;
6026 int tmp;
6027 __u32 tsn;
7c3ceb4f 6028 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
049b3ff5 6029 struct sock *sk = asoc->base.sk;
b01a2407 6030 struct net *net;
f1751c57
VY
6031 u16 ssn;
6032 u16 sid;
6033 u8 ordered = 0;
1da177e4
LT
6034
6035 data_hdr = chunk->subh.data_hdr = (sctp_datahdr_t *)chunk->skb->data;
6036 skb_pull(chunk->skb, sizeof(sctp_datahdr_t));
6037
6038 tsn = ntohl(data_hdr->tsn);
6039 SCTP_DEBUG_PRINTK("eat_data: TSN 0x%x.\n", tsn);
6040
6041 /* ASSERT: Now skb->data is really the user data. */
6042
6043 /* Process ECN based congestion.
6044 *
6045 * Since the chunk structure is reused for all chunks within
6046 * a packet, we use ecn_ce_done to track if we've already
6047 * done CE processing for this packet.
6048 *
6049 * We need to do ECN processing even if we plan to discard the
6050 * chunk later.
6051 */
6052
6053 if (!chunk->ecn_ce_done) {
6054 struct sctp_af *af;
6055 chunk->ecn_ce_done = 1;
6056
6057 af = sctp_get_af_specific(
eddc9ec5 6058 ipver2af(ip_hdr(chunk->skb)->version));
1da177e4
LT
6059
6060 if (af && af->is_ce(chunk->skb) && asoc->peer.ecn_capable) {
6061 /* Do real work as sideffect. */
6062 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_CE,
6063 SCTP_U32(tsn));
6064 }
6065 }
6066
6067 tmp = sctp_tsnmap_check(&asoc->peer.tsn_map, tsn);
6068 if (tmp < 0) {
6069 /* The TSN is too high--silently discard the chunk and
6070 * count on it getting retransmitted later.
6071 */
6072 return SCTP_IERROR_HIGH_TSN;
6073 } else if (tmp > 0) {
6074 /* This is a duplicate. Record it. */
6075 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_DUP, SCTP_U32(tsn));
6076 return SCTP_IERROR_DUP_TSN;
6077 }
6078
6079 /* This is a new TSN. */
6080
6081 /* Discard if there is no room in the receive window.
6082 * Actually, allow a little bit of overflow (up to a MTU).
6083 */
6084 datalen = ntohs(chunk->chunk_hdr->length);
6085 datalen -= sizeof(sctp_data_chunk_t);
6086
6087 deliver = SCTP_CMD_CHUNK_ULP;
6088
6089 /* Think about partial delivery. */
6090 if ((datalen >= asoc->rwnd) && (!asoc->ulpq.pd_mode)) {
6091
6092 /* Even if we don't accept this chunk there is
6093 * memory pressure.
6094 */
6095 sctp_add_cmd_sf(commands, SCTP_CMD_PART_DELIVER, SCTP_NULL());
6096 }
6097
d808ad9a 6098 /* Spill over rwnd a little bit. Note: While allowed, this spill over
1da177e4
LT
6099 * seems a bit troublesome in that frag_point varies based on
6100 * PMTU. In cases, such as loopback, this might be a rather
6101 * large spill over.
4d93df0a
NH
6102 */
6103 if ((!chunk->data_accepted) && (!asoc->rwnd || asoc->rwnd_over ||
6104 (datalen > asoc->rwnd + asoc->frag_point))) {
1da177e4
LT
6105
6106 /* If this is the next TSN, consider reneging to make
6107 * room. Note: Playing nice with a confused sender. A
6108 * malicious sender can still eat up all our buffer
6109 * space and in the future we may want to detect and
6110 * do more drastic reneging.
6111 */
7c3ceb4f
NH
6112 if (sctp_tsnmap_has_gap(map) &&
6113 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
1da177e4
LT
6114 SCTP_DEBUG_PRINTK("Reneging for tsn:%u\n", tsn);
6115 deliver = SCTP_CMD_RENEGE;
6116 } else {
6117 SCTP_DEBUG_PRINTK("Discard tsn: %u len: %Zd, "
6118 "rwnd: %d\n", tsn, datalen,
6119 asoc->rwnd);
6120 return SCTP_IERROR_IGNORE_TSN;
6121 }
6122 }
6123
4d93df0a
NH
6124 /*
6125 * Also try to renege to limit our memory usage in the event that
6126 * we are under memory pressure
3ab224be 6127 * If we can't renege, don't worry about it, the sk_rmem_schedule
4d93df0a
NH
6128 * in sctp_ulpevent_make_rcvmsg will drop the frame if we grow our
6129 * memory usage too much
6130 */
6131 if (*sk->sk_prot_creator->memory_pressure) {
6132 if (sctp_tsnmap_has_gap(map) &&
6133 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
6134 SCTP_DEBUG_PRINTK("Under Pressure! Reneging for tsn:%u\n", tsn);
6135 deliver = SCTP_CMD_RENEGE;
6136 }
6137 }
6138
1da177e4
LT
6139 /*
6140 * Section 3.3.10.9 No User Data (9)
6141 *
6142 * Cause of error
6143 * ---------------
6144 * No User Data: This error cause is returned to the originator of a
6145 * DATA chunk if a received DATA chunk has no user data.
6146 */
b01a2407 6147 net = sock_net(sk);
1da177e4
LT
6148 if (unlikely(0 == datalen)) {
6149 err = sctp_make_abort_no_data(asoc, chunk, tsn);
6150 if (err) {
6151 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
6152 SCTP_CHUNK(err));
6153 }
6154 /* We are going to ABORT, so we might as well stop
6155 * processing the rest of the chunks in the packet.
6156 */
6157 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
8de8c873
SS
6158 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
6159 SCTP_ERROR(ECONNABORTED));
1da177e4 6160 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5be291fe 6161 SCTP_PERR(SCTP_ERROR_NO_DATA));
b01a2407
EB
6162 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
6163 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
1da177e4
LT
6164 return SCTP_IERROR_NO_DATA;
6165 }
6166
9faa730f
SS
6167 chunk->data_accepted = 1;
6168
1da177e4
LT
6169 /* Note: Some chunks may get overcounted (if we drop) or overcounted
6170 * if we renege and the chunk arrives again.
6171 */
6172 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
b01a2407 6173 SCTP_INC_STATS(net, SCTP_MIB_INUNORDERCHUNKS);
f1751c57 6174 else {
b01a2407 6175 SCTP_INC_STATS(net, SCTP_MIB_INORDERCHUNKS);
f1751c57
VY
6176 ordered = 1;
6177 }
1da177e4
LT
6178
6179 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
6180 *
6181 * If an endpoint receive a DATA chunk with an invalid stream
6182 * identifier, it shall acknowledge the reception of the DATA chunk
6183 * following the normal procedure, immediately send an ERROR chunk
6184 * with cause set to "Invalid Stream Identifier" (See Section 3.3.10)
6185 * and discard the DATA chunk.
6186 */
f1751c57
VY
6187 sid = ntohs(data_hdr->stream);
6188 if (sid >= asoc->c.sinit_max_instreams) {
3888e9ef
VY
6189 /* Mark tsn as received even though we drop it */
6190 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_TSN, SCTP_U32(tsn));
6191
1da177e4
LT
6192 err = sctp_make_op_error(asoc, chunk, SCTP_ERROR_INV_STRM,
6193 &data_hdr->stream,
6383cfb3
VY
6194 sizeof(data_hdr->stream),
6195 sizeof(u16));
1da177e4
LT
6196 if (err)
6197 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
6198 SCTP_CHUNK(err));
6199 return SCTP_IERROR_BAD_STREAM;
6200 }
6201
f1751c57
VY
6202 /* Check to see if the SSN is possible for this TSN.
6203 * The biggest gap we can record is 4K wide. Since SSNs wrap
6204 * at an unsigned short, there is no way that an SSN can
6205 * wrap and for a valid TSN. We can simply check if the current
6206 * SSN is smaller then the next expected one. If it is, it wrapped
6207 * and is invalid.
6208 */
6209 ssn = ntohs(data_hdr->ssn);
6210 if (ordered && SSN_lt(ssn, sctp_ssn_peek(&asoc->ssnmap->in, sid))) {
6211 return SCTP_IERROR_PROTO_VIOLATION;
6212 }
6213
1da177e4
LT
6214 /* Send the data up to the user. Note: Schedule the
6215 * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK
6216 * chunk needs the updated rwnd.
6217 */
6218 sctp_add_cmd_sf(commands, deliver, SCTP_CHUNK(chunk));
6219
6220 return SCTP_IERROR_NO_ERROR;
6221}