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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):
91705c61 31 * lksctp developers <linux-sctp@vger.kernel.org>
1da177e4 32 *
1da177e4
LT
33 * Written or modified by:
34 * La Monte H.P. Yarroll <piggy@acm.org>
35 * Karl Knutson <karl@athena.chicago.il.us>
36 * Mathew Kotowsky <kotowsky@sctp.org>
37 * Sridhar Samudrala <samudrala@us.ibm.com>
38 * Jon Grimm <jgrimm@us.ibm.com>
39 * Hui Huang <hui.huang@nokia.com>
40 * Dajiang Zhang <dajiang.zhang@nokia.com>
41 * Daisy Chang <daisyc@us.ibm.com>
42 * Ardelle Fan <ardelle.fan@intel.com>
43 * Ryan Layer <rmlayer@us.ibm.com>
44 * Kevin Gao <kevin.gao@intel.com>
1da177e4
LT
45 */
46
145ce502
JP
47#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
48
1da177e4
LT
49#include <linux/types.h>
50#include <linux/kernel.h>
51#include <linux/ip.h>
52#include <linux/ipv6.h>
53#include <linux/net.h>
54#include <linux/inet.h>
5a0e3ad6 55#include <linux/slab.h>
1da177e4
LT
56#include <net/sock.h>
57#include <net/inet_ecn.h>
58#include <linux/skbuff.h>
59#include <net/sctp/sctp.h>
60#include <net/sctp/sm.h>
61#include <net/sctp/structs.h>
62
24cb81a6
EB
63static struct sctp_packet *sctp_abort_pkt_new(struct net *net,
64 const struct sctp_endpoint *ep,
1da177e4
LT
65 const struct sctp_association *asoc,
66 struct sctp_chunk *chunk,
67 const void *payload,
68 size_t paylen);
69static int sctp_eat_data(const struct sctp_association *asoc,
70 struct sctp_chunk *chunk,
71 sctp_cmd_seq_t *commands);
2ce95503
EB
72static struct sctp_packet *sctp_ootb_pkt_new(struct net *net,
73 const struct sctp_association *asoc,
1da177e4 74 const struct sctp_chunk *chunk);
24cb81a6
EB
75static void sctp_send_stale_cookie_err(struct net *net,
76 const struct sctp_endpoint *ep,
1da177e4
LT
77 const struct sctp_association *asoc,
78 const struct sctp_chunk *chunk,
79 sctp_cmd_seq_t *commands,
80 struct sctp_chunk *err_chunk);
24cb81a6
EB
81static sctp_disposition_t sctp_sf_do_5_2_6_stale(struct net *net,
82 const struct sctp_endpoint *ep,
1da177e4
LT
83 const struct sctp_association *asoc,
84 const sctp_subtype_t type,
85 void *arg,
86 sctp_cmd_seq_t *commands);
24cb81a6
EB
87static sctp_disposition_t sctp_sf_shut_8_4_5(struct net *net,
88 const struct sctp_endpoint *ep,
1da177e4
LT
89 const struct sctp_association *asoc,
90 const sctp_subtype_t type,
91 void *arg,
92 sctp_cmd_seq_t *commands);
24cb81a6
EB
93static sctp_disposition_t sctp_sf_tabort_8_4_8(struct net *net,
94 const struct sctp_endpoint *ep,
ece25dfa
VY
95 const struct sctp_association *asoc,
96 const sctp_subtype_t type,
97 void *arg,
98 sctp_cmd_seq_t *commands);
1da177e4
LT
99static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk);
100
24cb81a6
EB
101static sctp_disposition_t sctp_stop_t1_and_abort(struct net *net,
102 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(
24cb81a6 108 struct net *net,
ece25dfa 109 const struct sctp_endpoint *ep,
aecedeab
WY
110 const struct sctp_association *asoc,
111 void *arg,
112 sctp_cmd_seq_t *commands,
113 const __u8 *payload,
114 const size_t paylen);
115
52c1da39 116static sctp_disposition_t sctp_sf_violation_chunklen(
24cb81a6 117 struct net *net,
52c1da39
AB
118 const struct sctp_endpoint *ep,
119 const struct sctp_association *asoc,
120 const sctp_subtype_t type,
121 void *arg,
122 sctp_cmd_seq_t *commands);
1da177e4 123
6f4c618d 124static sctp_disposition_t sctp_sf_violation_paramlen(
24cb81a6 125 struct net *net,
6f4c618d
WY
126 const struct sctp_endpoint *ep,
127 const struct sctp_association *asoc,
128 const sctp_subtype_t type,
ba016670 129 void *arg, void *ext,
6f4c618d
WY
130 sctp_cmd_seq_t *commands);
131
aecedeab 132static sctp_disposition_t sctp_sf_violation_ctsn(
24cb81a6 133 struct net *net,
aecedeab
WY
134 const struct sctp_endpoint *ep,
135 const struct sctp_association *asoc,
136 const sctp_subtype_t type,
137 void *arg,
138 sctp_cmd_seq_t *commands);
139
ece25dfa 140static sctp_disposition_t sctp_sf_violation_chunk(
24cb81a6 141 struct net *net,
ece25dfa
VY
142 const struct sctp_endpoint *ep,
143 const struct sctp_association *asoc,
144 const sctp_subtype_t type,
145 void *arg,
146 sctp_cmd_seq_t *commands);
147
24cb81a6
EB
148static sctp_ierror_t sctp_sf_authenticate(struct net *net,
149 const struct sctp_endpoint *ep,
bbd0d598
VY
150 const struct sctp_association *asoc,
151 const sctp_subtype_t type,
152 struct sctp_chunk *chunk);
153
24cb81a6
EB
154static sctp_disposition_t __sctp_sf_do_9_1_abort(struct net *net,
155 const struct sctp_endpoint *ep,
75205f47
VY
156 const struct sctp_association *asoc,
157 const sctp_subtype_t type,
158 void *arg,
159 sctp_cmd_seq_t *commands);
160
1da177e4
LT
161/* Small helper function that checks if the chunk length
162 * is of the appropriate length. The 'required_length' argument
163 * is set to be the size of a specific chunk we are testing.
164 * Return Values: 1 = Valid length
165 * 0 = Invalid length
166 *
167 */
168static inline int
169sctp_chunk_length_valid(struct sctp_chunk *chunk,
170 __u16 required_length)
171{
172 __u16 chunk_length = ntohs(chunk->chunk_hdr->length);
173
174 if (unlikely(chunk_length < required_length))
175 return 0;
176
177 return 1;
178}
179
180/**********************************************************
181 * These are the state functions for handling chunk events.
182 **********************************************************/
183
184/*
185 * Process the final SHUTDOWN COMPLETE.
186 *
187 * Section: 4 (C) (diagram), 9.2
188 * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify
189 * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be
190 * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint
191 * should stop the T2-shutdown timer and remove all knowledge of the
192 * association (and thus the association enters the CLOSED state).
193 *
047a2428 194 * Verification Tag: 8.5.1(C), sctpimpguide 2.41.
1da177e4
LT
195 * C) Rules for packet carrying SHUTDOWN COMPLETE:
196 * ...
047a2428
JF
197 * - The receiver of a SHUTDOWN COMPLETE shall accept the packet
198 * if the Verification Tag field of the packet matches its own tag and
199 * the T bit is not set
200 * OR
201 * it is set to its peer's tag and the T bit is set in the Chunk
202 * Flags.
203 * Otherwise, the receiver MUST silently discard the packet
204 * and take no further action. An endpoint MUST ignore the
205 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
1da177e4
LT
206 *
207 * Inputs
208 * (endpoint, asoc, chunk)
209 *
210 * Outputs
211 * (asoc, reply_msg, msg_up, timers, counters)
212 *
213 * The return value is the disposition of the chunk.
214 */
24cb81a6
EB
215sctp_disposition_t sctp_sf_do_4_C(struct net *net,
216 const struct sctp_endpoint *ep,
1da177e4
LT
217 const struct sctp_association *asoc,
218 const sctp_subtype_t type,
219 void *arg,
220 sctp_cmd_seq_t *commands)
221{
222 struct sctp_chunk *chunk = arg;
223 struct sctp_ulpevent *ev;
224
ece25dfa 225 if (!sctp_vtag_verify_either(chunk, asoc))
24cb81a6 226 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
ece25dfa 227
1da177e4
LT
228 /* RFC 2960 6.10 Bundling
229 *
230 * An endpoint MUST NOT bundle INIT, INIT ACK or
231 * SHUTDOWN COMPLETE with any other chunks.
232 */
233 if (!chunk->singleton)
24cb81a6 234 return sctp_sf_violation_chunk(net, ep, asoc, type, arg, commands);
1da177e4 235
ece25dfa
VY
236 /* Make sure that the SHUTDOWN_COMPLETE chunk has a valid length. */
237 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
24cb81a6 238 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
ece25dfa 239 commands);
1da177e4
LT
240
241 /* RFC 2960 10.2 SCTP-to-ULP
242 *
243 * H) SHUTDOWN COMPLETE notification
244 *
245 * When SCTP completes the shutdown procedures (section 9.2) this
246 * notification is passed to the upper layer.
247 */
248 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
a5a35e76 249 0, 0, 0, NULL, GFP_ATOMIC);
df7deeb5
VY
250 if (ev)
251 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
d808ad9a 252 SCTP_ULPEVENT(ev));
1da177e4
LT
253
254 /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint
255 * will verify that it is in SHUTDOWN-ACK-SENT state, if it is
256 * not the chunk should be discarded. If the endpoint is in
257 * the SHUTDOWN-ACK-SENT state the endpoint should stop the
258 * T2-shutdown timer and remove all knowledge of the
259 * association (and thus the association enters the CLOSED
260 * state).
261 */
262 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
263 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
264
265 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
266 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
267
268 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
269 SCTP_STATE(SCTP_STATE_CLOSED));
270
b01a2407
EB
271 SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS);
272 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
1da177e4
LT
273
274 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
275
276 return SCTP_DISPOSITION_DELETE_TCB;
1da177e4
LT
277}
278
279/*
280 * Respond to a normal INIT chunk.
281 * We are the side that is being asked for an association.
282 *
283 * Section: 5.1 Normal Establishment of an Association, B
284 * B) "Z" shall respond immediately with an INIT ACK chunk. The
285 * destination IP address of the INIT ACK MUST be set to the source
286 * IP address of the INIT to which this INIT ACK is responding. In
287 * the response, besides filling in other parameters, "Z" must set the
288 * Verification Tag field to Tag_A, and also provide its own
289 * Verification Tag (Tag_Z) in the Initiate Tag field.
290 *
d808ad9a 291 * Verification Tag: Must be 0.
1da177e4
LT
292 *
293 * Inputs
294 * (endpoint, asoc, chunk)
295 *
296 * Outputs
297 * (asoc, reply_msg, msg_up, timers, counters)
298 *
299 * The return value is the disposition of the chunk.
300 */
24cb81a6
EB
301sctp_disposition_t sctp_sf_do_5_1B_init(struct net *net,
302 const struct sctp_endpoint *ep,
1da177e4
LT
303 const struct sctp_association *asoc,
304 const sctp_subtype_t type,
305 void *arg,
306 sctp_cmd_seq_t *commands)
307{
308 struct sctp_chunk *chunk = arg;
309 struct sctp_chunk *repl;
310 struct sctp_association *new_asoc;
311 struct sctp_chunk *err_chunk;
312 struct sctp_packet *packet;
313 sctp_unrecognized_param_t *unk_param;
1da177e4
LT
314 int len;
315
316 /* 6.10 Bundling
317 * An endpoint MUST NOT bundle INIT, INIT ACK or
318 * SHUTDOWN COMPLETE with any other chunks.
d808ad9a 319 *
1da177e4
LT
320 * IG Section 2.11.2
321 * Furthermore, we require that the receiver of an INIT chunk MUST
322 * enforce these rules by silently discarding an arriving packet
323 * with an INIT chunk that is bundled with other chunks.
324 */
325 if (!chunk->singleton)
24cb81a6 326 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
327
328 /* If the packet is an OOTB packet which is temporarily on the
329 * control endpoint, respond with an ABORT.
330 */
2ce95503 331 if (ep == sctp_sk(net->sctp.ctl_sock)->ep) {
b01a2407 332 SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
24cb81a6 333 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
8190f89d 334 }
1da177e4 335
1da177e4 336 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
d808ad9a 337 * Tag.
1da177e4
LT
338 */
339 if (chunk->sctp_hdr->vtag != 0)
24cb81a6 340 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
1da177e4
LT
341
342 /* Make sure that the INIT chunk has a valid length.
343 * Normally, this would cause an ABORT with a Protocol Violation
344 * error, but since we don't have an association, we'll
345 * just discard the packet.
346 */
347 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
24cb81a6 348 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4 349
bec9640b
VY
350 /* If the INIT is coming toward a closing socket, we'll send back
351 * and ABORT. Essentially, this catches the race of INIT being
352 * backloged to the socket at the same time as the user isses close().
353 * Since the socket and all its associations are going away, we
354 * can treat this OOTB
355 */
356 if (sctp_sstate(ep->base.sk, CLOSING))
24cb81a6 357 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
bec9640b 358
1da177e4
LT
359 /* Verify the INIT chunk before processing it. */
360 err_chunk = NULL;
f53b5b09 361 if (!sctp_verify_init(net, asoc, chunk->chunk_hdr->type,
1da177e4
LT
362 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
363 &err_chunk)) {
364 /* This chunk contains fatal error. It is to be discarded.
365 * Send an ABORT, with causes if there is any.
366 */
367 if (err_chunk) {
24cb81a6 368 packet = sctp_abort_pkt_new(net, ep, asoc, arg,
1da177e4
LT
369 (__u8 *)(err_chunk->chunk_hdr) +
370 sizeof(sctp_chunkhdr_t),
371 ntohs(err_chunk->chunk_hdr->length) -
372 sizeof(sctp_chunkhdr_t));
373
374 sctp_chunk_free(err_chunk);
375
376 if (packet) {
377 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
378 SCTP_PACKET(packet));
b01a2407 379 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
1da177e4
LT
380 return SCTP_DISPOSITION_CONSUME;
381 } else {
382 return SCTP_DISPOSITION_NOMEM;
383 }
384 } else {
24cb81a6 385 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg,
1da177e4
LT
386 commands);
387 }
388 }
389
d808ad9a 390 /* Grab the INIT header. */
1da177e4
LT
391 chunk->subh.init_hdr = (sctp_inithdr_t *)chunk->skb->data;
392
393 /* Tag the variable length parameters. */
394 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
395
396 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
397 if (!new_asoc)
398 goto nomem;
399
409b95af
VY
400 if (sctp_assoc_set_bind_addr_from_ep(new_asoc,
401 sctp_scope(sctp_source(chunk)),
402 GFP_ATOMIC) < 0)
403 goto nomem_init;
404
1da177e4 405 /* The call, sctp_process_init(), can fail on memory allocation. */
de6becdc 406 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk),
1da177e4
LT
407 (sctp_init_chunk_t *)chunk->chunk_hdr,
408 GFP_ATOMIC))
409 goto nomem_init;
410
1da177e4
LT
411 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
412
413 /* If there are errors need to be reported for unknown parameters,
414 * make sure to reserve enough room in the INIT ACK for them.
415 */
416 len = 0;
417 if (err_chunk)
418 len = ntohs(err_chunk->chunk_hdr->length) -
419 sizeof(sctp_chunkhdr_t);
420
1da177e4
LT
421 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
422 if (!repl)
df7deeb5 423 goto nomem_init;
1da177e4
LT
424
425 /* If there are errors need to be reported for unknown parameters,
426 * include them in the outgoing INIT ACK as "Unrecognized parameter"
427 * parameter.
428 */
429 if (err_chunk) {
430 /* Get the "Unrecognized parameter" parameter(s) out of the
431 * ERROR chunk generated by sctp_verify_init(). Since the
432 * error cause code for "unknown parameter" and the
433 * "Unrecognized parameter" type is the same, we can
434 * construct the parameters in INIT ACK by copying the
435 * ERROR causes over.
436 */
437 unk_param = (sctp_unrecognized_param_t *)
438 ((__u8 *)(err_chunk->chunk_hdr) +
439 sizeof(sctp_chunkhdr_t));
440 /* Replace the cause code with the "Unrecognized parameter"
441 * parameter type.
442 */
443 sctp_addto_chunk(repl, len, unk_param);
444 sctp_chunk_free(err_chunk);
445 }
446
df7deeb5
VY
447 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
448
1da177e4
LT
449 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
450
451 /*
452 * Note: After sending out INIT ACK with the State Cookie parameter,
453 * "Z" MUST NOT allocate any resources, nor keep any states for the
454 * new association. Otherwise, "Z" will be vulnerable to resource
455 * attacks.
456 */
457 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
458
459 return SCTP_DISPOSITION_DELETE_TCB;
460
1da177e4
LT
461nomem_init:
462 sctp_association_free(new_asoc);
463nomem:
df7deeb5
VY
464 if (err_chunk)
465 sctp_chunk_free(err_chunk);
1da177e4
LT
466 return SCTP_DISPOSITION_NOMEM;
467}
468
469/*
470 * Respond to a normal INIT ACK chunk.
471 * We are the side that is initiating the association.
472 *
473 * Section: 5.1 Normal Establishment of an Association, C
474 * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init
475 * timer and leave COOKIE-WAIT state. "A" shall then send the State
476 * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start
477 * the T1-cookie timer, and enter the COOKIE-ECHOED state.
478 *
479 * Note: The COOKIE ECHO chunk can be bundled with any pending outbound
480 * DATA chunks, but it MUST be the first chunk in the packet and
481 * until the COOKIE ACK is returned the sender MUST NOT send any
482 * other packets to the peer.
483 *
484 * Verification Tag: 3.3.3
485 * If the value of the Initiate Tag in a received INIT ACK chunk is
486 * found to be 0, the receiver MUST treat it as an error and close the
487 * association by transmitting an ABORT.
488 *
489 * Inputs
490 * (endpoint, asoc, chunk)
491 *
492 * Outputs
493 * (asoc, reply_msg, msg_up, timers, counters)
494 *
495 * The return value is the disposition of the chunk.
496 */
24cb81a6
EB
497sctp_disposition_t sctp_sf_do_5_1C_ack(struct net *net,
498 const struct sctp_endpoint *ep,
1da177e4
LT
499 const struct sctp_association *asoc,
500 const sctp_subtype_t type,
501 void *arg,
502 sctp_cmd_seq_t *commands)
503{
504 struct sctp_chunk *chunk = arg;
505 sctp_init_chunk_t *initchunk;
1da177e4
LT
506 struct sctp_chunk *err_chunk;
507 struct sctp_packet *packet;
1da177e4
LT
508
509 if (!sctp_vtag_verify(chunk, asoc))
24cb81a6 510 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4 511
1da177e4
LT
512 /* 6.10 Bundling
513 * An endpoint MUST NOT bundle INIT, INIT ACK or
514 * SHUTDOWN COMPLETE with any other chunks.
515 */
516 if (!chunk->singleton)
24cb81a6 517 return sctp_sf_violation_chunk(net, ep, asoc, type, arg, commands);
1da177e4 518
ece25dfa
VY
519 /* Make sure that the INIT-ACK chunk has a valid length */
520 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_initack_chunk_t)))
24cb81a6 521 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
ece25dfa 522 commands);
1da177e4
LT
523 /* Grab the INIT header. */
524 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
525
1da177e4
LT
526 /* Verify the INIT chunk before processing it. */
527 err_chunk = NULL;
f53b5b09 528 if (!sctp_verify_init(net, asoc, chunk->chunk_hdr->type,
1da177e4
LT
529 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
530 &err_chunk)) {
531
853f4b50
VY
532 sctp_error_t error = SCTP_ERROR_NO_RESOURCE;
533
1da177e4 534 /* This chunk contains fatal error. It is to be discarded.
d6701191
VY
535 * Send an ABORT, with causes. If there are no causes,
536 * then there wasn't enough memory. Just terminate
537 * the association.
1da177e4
LT
538 */
539 if (err_chunk) {
24cb81a6 540 packet = sctp_abort_pkt_new(net, ep, asoc, arg,
1da177e4
LT
541 (__u8 *)(err_chunk->chunk_hdr) +
542 sizeof(sctp_chunkhdr_t),
543 ntohs(err_chunk->chunk_hdr->length) -
544 sizeof(sctp_chunkhdr_t));
545
546 sctp_chunk_free(err_chunk);
547
548 if (packet) {
549 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
550 SCTP_PACKET(packet));
24cb81a6 551 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
8de8c873 552 error = SCTP_ERROR_INV_PARAM;
1da177e4 553 }
1da177e4 554 }
bbd0d598
VY
555
556 /* SCTP-AUTH, Section 6.3:
557 * It should be noted that if the receiver wants to tear
558 * down an association in an authenticated way only, the
559 * handling of malformed packets should not result in
560 * tearing down the association.
561 *
562 * This means that if we only want to abort associations
563 * in an authenticated way (i.e AUTH+ABORT), then we
25985edc 564 * can't destroy this association just because the packet
bbd0d598
VY
565 * was malformed.
566 */
567 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
24cb81a6 568 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
bbd0d598 569
24cb81a6
EB
570 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
571 return sctp_stop_t1_and_abort(net, commands, error, ECONNREFUSED,
8de8c873 572 asoc, chunk->transport);
1da177e4
LT
573 }
574
575 /* Tag the variable length parameters. Note that we never
576 * convert the parameters in an INIT chunk.
577 */
578 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
579
580 initchunk = (sctp_init_chunk_t *) chunk->chunk_hdr;
581
582 sctp_add_cmd_sf(commands, SCTP_CMD_PEER_INIT,
583 SCTP_PEER_INIT(initchunk));
584
3f7a87d2
FF
585 /* Reset init error count upon receipt of INIT-ACK. */
586 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
587
1da177e4
LT
588 /* 5.1 C) "A" shall stop the T1-init timer and leave
589 * COOKIE-WAIT state. "A" shall then ... start the T1-cookie
590 * timer, and enter the COOKIE-ECHOED state.
591 */
592 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
593 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
594 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
595 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
596 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
597 SCTP_STATE(SCTP_STATE_COOKIE_ECHOED));
598
730fc3d0
VY
599 /* SCTP-AUTH: genereate the assocition shared keys so that
600 * we can potentially signe the COOKIE-ECHO.
601 */
602 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_SHKEY, SCTP_NULL());
603
1da177e4
LT
604 /* 5.1 C) "A" shall then send the State Cookie received in the
605 * INIT ACK chunk in a COOKIE ECHO chunk, ...
606 */
607 /* If there is any errors to report, send the ERROR chunk generated
608 * for unknown parameters as well.
609 */
610 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_COOKIE_ECHO,
611 SCTP_CHUNK(err_chunk));
612
613 return SCTP_DISPOSITION_CONSUME;
1da177e4
LT
614}
615
616/*
617 * Respond to a normal COOKIE ECHO chunk.
618 * We are the side that is being asked for an association.
619 *
620 * Section: 5.1 Normal Establishment of an Association, D
621 * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply
622 * with a COOKIE ACK chunk after building a TCB and moving to
623 * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with
624 * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK
625 * chunk MUST be the first chunk in the packet.
626 *
627 * IMPLEMENTATION NOTE: An implementation may choose to send the
628 * Communication Up notification to the SCTP user upon reception
629 * of a valid COOKIE ECHO chunk.
630 *
631 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
632 * D) Rules for packet carrying a COOKIE ECHO
633 *
634 * - When sending a COOKIE ECHO, the endpoint MUST use the value of the
635 * Initial Tag received in the INIT ACK.
636 *
637 * - The receiver of a COOKIE ECHO follows the procedures in Section 5.
638 *
639 * Inputs
640 * (endpoint, asoc, chunk)
641 *
642 * Outputs
643 * (asoc, reply_msg, msg_up, timers, counters)
644 *
645 * The return value is the disposition of the chunk.
646 */
24cb81a6
EB
647sctp_disposition_t sctp_sf_do_5_1D_ce(struct net *net,
648 const struct sctp_endpoint *ep,
1da177e4
LT
649 const struct sctp_association *asoc,
650 const sctp_subtype_t type, void *arg,
651 sctp_cmd_seq_t *commands)
652{
653 struct sctp_chunk *chunk = arg;
654 struct sctp_association *new_asoc;
655 sctp_init_chunk_t *peer_init;
656 struct sctp_chunk *repl;
df7deeb5 657 struct sctp_ulpevent *ev, *ai_ev = NULL;
1da177e4
LT
658 int error = 0;
659 struct sctp_chunk *err_chk_p;
609ee467 660 struct sock *sk;
1da177e4
LT
661
662 /* If the packet is an OOTB packet which is temporarily on the
663 * control endpoint, respond with an ABORT.
664 */
2ce95503 665 if (ep == sctp_sk(net->sctp.ctl_sock)->ep) {
b01a2407 666 SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
24cb81a6 667 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
8190f89d 668 }
1da177e4
LT
669
670 /* Make sure that the COOKIE_ECHO chunk has a valid length.
671 * In this case, we check that we have enough for at least a
672 * chunk header. More detailed verification is done
673 * in sctp_unpack_cookie().
674 */
675 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
24cb81a6 676 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4 677
609ee467
VY
678 /* If the endpoint is not listening or if the number of associations
679 * on the TCP-style socket exceed the max backlog, respond with an
680 * ABORT.
681 */
682 sk = ep->base.sk;
683 if (!sctp_sstate(sk, LISTENING) ||
684 (sctp_style(sk, TCP) && sk_acceptq_is_full(sk)))
24cb81a6 685 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
609ee467 686
1da177e4
LT
687 /* "Decode" the chunk. We have no optional parameters so we
688 * are in good shape.
689 */
d808ad9a 690 chunk->subh.cookie_hdr =
1da177e4 691 (struct sctp_signed_cookie *)chunk->skb->data;
62b08083
SS
692 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
693 sizeof(sctp_chunkhdr_t)))
694 goto nomem;
1da177e4
LT
695
696 /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
697 * "Z" will reply with a COOKIE ACK chunk after building a TCB
698 * and moving to the ESTABLISHED state.
699 */
700 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
701 &err_chk_p);
702
703 /* FIXME:
704 * If the re-build failed, what is the proper error path
705 * from here?
706 *
707 * [We should abort the association. --piggy]
708 */
709 if (!new_asoc) {
710 /* FIXME: Several errors are possible. A bad cookie should
711 * be silently discarded, but think about logging it too.
712 */
713 switch (error) {
714 case -SCTP_IERROR_NOMEM:
715 goto nomem;
716
717 case -SCTP_IERROR_STALE_COOKIE:
24cb81a6 718 sctp_send_stale_cookie_err(net, ep, asoc, chunk, commands,
1da177e4 719 err_chk_p);
24cb81a6 720 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
721
722 case -SCTP_IERROR_BAD_SIG:
723 default:
24cb81a6 724 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3ff50b79 725 }
1da177e4
LT
726 }
727
1da177e4 728
df7deeb5
VY
729 /* Delay state machine commands until later.
730 *
731 * Re-build the bind address for the association is done in
1da177e4
LT
732 * the sctp_unpack_cookie() already.
733 */
734 /* This is a brand-new association, so these are not yet side
735 * effects--it is safe to run them here.
736 */
737 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
738
de6becdc 739 if (!sctp_process_init(new_asoc, chunk,
6a1e5f33 740 &chunk->subh.cookie_hdr->c.peer_addr,
1da177e4
LT
741 peer_init, GFP_ATOMIC))
742 goto nomem_init;
743
730fc3d0
VY
744 /* SCTP-AUTH: Now that we've populate required fields in
745 * sctp_process_init, set up the assocaition shared keys as
746 * necessary so that we can potentially authenticate the ACK
747 */
748 error = sctp_auth_asoc_init_active_key(new_asoc, GFP_ATOMIC);
749 if (error)
750 goto nomem_init;
751
bbd0d598
VY
752 /* SCTP-AUTH: auth_chunk pointer is only set when the cookie-echo
753 * is supposed to be authenticated and we have to do delayed
754 * authentication. We've just recreated the association using
755 * the information in the cookie and now it's much easier to
756 * do the authentication.
757 */
758 if (chunk->auth_chunk) {
759 struct sctp_chunk auth;
760 sctp_ierror_t ret;
761
762 /* set-up our fake chunk so that we can process it */
763 auth.skb = chunk->auth_chunk;
764 auth.asoc = chunk->asoc;
765 auth.sctp_hdr = chunk->sctp_hdr;
766 auth.chunk_hdr = (sctp_chunkhdr_t *)skb_push(chunk->auth_chunk,
767 sizeof(sctp_chunkhdr_t));
768 skb_pull(chunk->auth_chunk, sizeof(sctp_chunkhdr_t));
769 auth.transport = chunk->transport;
770
24cb81a6 771 ret = sctp_sf_authenticate(net, ep, new_asoc, type, &auth);
bbd0d598
VY
772
773 /* We can now safely free the auth_chunk clone */
774 kfree_skb(chunk->auth_chunk);
775
776 if (ret != SCTP_IERROR_NO_ERROR) {
777 sctp_association_free(new_asoc);
24cb81a6 778 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
bbd0d598
VY
779 }
780 }
781
1da177e4
LT
782 repl = sctp_make_cookie_ack(new_asoc, chunk);
783 if (!repl)
df7deeb5 784 goto nomem_init;
1da177e4
LT
785
786 /* RFC 2960 5.1 Normal Establishment of an Association
787 *
788 * D) IMPLEMENTATION NOTE: An implementation may choose to
789 * send the Communication Up notification to the SCTP user
790 * upon reception of a valid COOKIE ECHO chunk.
791 */
792 ev = sctp_ulpevent_make_assoc_change(new_asoc, 0, SCTP_COMM_UP, 0,
793 new_asoc->c.sinit_num_ostreams,
794 new_asoc->c.sinit_max_instreams,
a5a35e76 795 NULL, GFP_ATOMIC);
1da177e4
LT
796 if (!ev)
797 goto nomem_ev;
798
d808ad9a 799 /* Sockets API Draft Section 5.3.1.6
0f3fffd8 800 * When a peer sends a Adaptation Layer Indication parameter , SCTP
1da177e4 801 * delivers this notification to inform the application that of the
0f3fffd8 802 * peers requested adaptation layer.
1da177e4 803 */
0f3fffd8
ISJ
804 if (new_asoc->peer.adaptation_ind) {
805 ai_ev = sctp_ulpevent_make_adaptation_indication(new_asoc,
1da177e4 806 GFP_ATOMIC);
df7deeb5
VY
807 if (!ai_ev)
808 goto nomem_aiev;
809 }
810
811 /* Add all the state machine commands now since we've created
812 * everything. This way we don't introduce memory corruptions
813 * during side-effect processing and correclty count established
814 * associations.
815 */
816 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
817 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
818 SCTP_STATE(SCTP_STATE_ESTABLISHED));
b01a2407
EB
819 SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
820 SCTP_INC_STATS(net, SCTP_MIB_PASSIVEESTABS);
df7deeb5
VY
821 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
822
823 if (new_asoc->autoclose)
824 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
825 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
826
df7deeb5
VY
827 /* This will send the COOKIE ACK */
828 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
829
830 /* Queue the ASSOC_CHANGE event */
831 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
832
833 /* Send up the Adaptation Layer Indication event */
834 if (ai_ev)
1da177e4 835 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
df7deeb5 836 SCTP_ULPEVENT(ai_ev));
1da177e4
LT
837
838 return SCTP_DISPOSITION_CONSUME;
839
df7deeb5
VY
840nomem_aiev:
841 sctp_ulpevent_free(ev);
1da177e4
LT
842nomem_ev:
843 sctp_chunk_free(repl);
1da177e4
LT
844nomem_init:
845 sctp_association_free(new_asoc);
846nomem:
847 return SCTP_DISPOSITION_NOMEM;
848}
849
850/*
851 * Respond to a normal COOKIE ACK chunk.
852 * We are the side that is being asked for an association.
853 *
854 * RFC 2960 5.1 Normal Establishment of an Association
855 *
856 * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the
857 * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie
858 * timer. It may also notify its ULP about the successful
859 * establishment of the association with a Communication Up
860 * notification (see Section 10).
861 *
862 * Verification Tag:
863 * Inputs
864 * (endpoint, asoc, chunk)
865 *
866 * Outputs
867 * (asoc, reply_msg, msg_up, timers, counters)
868 *
869 * The return value is the disposition of the chunk.
870 */
24cb81a6
EB
871sctp_disposition_t sctp_sf_do_5_1E_ca(struct net *net,
872 const struct sctp_endpoint *ep,
1da177e4
LT
873 const struct sctp_association *asoc,
874 const sctp_subtype_t type, void *arg,
875 sctp_cmd_seq_t *commands)
876{
877 struct sctp_chunk *chunk = arg;
878 struct sctp_ulpevent *ev;
879
880 if (!sctp_vtag_verify(chunk, asoc))
24cb81a6 881 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
882
883 /* Verify that the chunk length for the COOKIE-ACK is OK.
884 * If we don't do this, any bundled chunks may be junked.
885 */
886 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
24cb81a6 887 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4
LT
888 commands);
889
890 /* Reset init error count upon receipt of COOKIE-ACK,
891 * to avoid problems with the managemement of this
892 * counter in stale cookie situations when a transition back
893 * from the COOKIE-ECHOED state to the COOKIE-WAIT
894 * state is performed.
895 */
3f7a87d2 896 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
1da177e4
LT
897
898 /* RFC 2960 5.1 Normal Establishment of an Association
899 *
900 * E) Upon reception of the COOKIE ACK, endpoint "A" will move
901 * from the COOKIE-ECHOED state to the ESTABLISHED state,
902 * stopping the T1-cookie timer.
903 */
904 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
905 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
906 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
907 SCTP_STATE(SCTP_STATE_ESTABLISHED));
b01a2407
EB
908 SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
909 SCTP_INC_STATS(net, SCTP_MIB_ACTIVEESTABS);
1da177e4
LT
910 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
911 if (asoc->autoclose)
912 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
913 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
1da177e4
LT
914
915 /* It may also notify its ULP about the successful
916 * establishment of the association with a Communication Up
917 * notification (see Section 10).
918 */
919 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP,
920 0, asoc->c.sinit_num_ostreams,
921 asoc->c.sinit_max_instreams,
a5a35e76 922 NULL, GFP_ATOMIC);
1da177e4
LT
923
924 if (!ev)
925 goto nomem;
926
927 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
928
929 /* Sockets API Draft Section 5.3.1.6
0f3fffd8 930 * When a peer sends a Adaptation Layer Indication parameter , SCTP
1da177e4 931 * delivers this notification to inform the application that of the
0f3fffd8 932 * peers requested adaptation layer.
1da177e4 933 */
0f3fffd8
ISJ
934 if (asoc->peer.adaptation_ind) {
935 ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
1da177e4
LT
936 if (!ev)
937 goto nomem;
938
939 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
940 SCTP_ULPEVENT(ev));
941 }
942
943 return SCTP_DISPOSITION_CONSUME;
944nomem:
945 return SCTP_DISPOSITION_NOMEM;
946}
947
948/* Generate and sendout a heartbeat packet. */
949static sctp_disposition_t sctp_sf_heartbeat(const struct sctp_endpoint *ep,
950 const struct sctp_association *asoc,
951 const sctp_subtype_t type,
952 void *arg,
953 sctp_cmd_seq_t *commands)
954{
955 struct sctp_transport *transport = (struct sctp_transport *) arg;
956 struct sctp_chunk *reply;
1da177e4
LT
957
958 /* Send a heartbeat to our peer. */
92c73af5 959 reply = sctp_make_heartbeat(asoc, transport);
1da177e4
LT
960 if (!reply)
961 return SCTP_DISPOSITION_NOMEM;
962
963 /* Set rto_pending indicating that an RTT measurement
964 * is started with this heartbeat chunk.
965 */
966 sctp_add_cmd_sf(commands, SCTP_CMD_RTO_PENDING,
967 SCTP_TRANSPORT(transport));
968
969 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
970 return SCTP_DISPOSITION_CONSUME;
971}
972
973/* Generate a HEARTBEAT packet on the given transport. */
24cb81a6
EB
974sctp_disposition_t sctp_sf_sendbeat_8_3(struct net *net,
975 const struct sctp_endpoint *ep,
1da177e4
LT
976 const struct sctp_association *asoc,
977 const sctp_subtype_t type,
978 void *arg,
979 sctp_cmd_seq_t *commands)
980{
981 struct sctp_transport *transport = (struct sctp_transport *) arg;
982
b9f84786 983 if (asoc->overall_error_count >= asoc->max_retrans) {
8de8c873
SS
984 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
985 SCTP_ERROR(ETIMEDOUT));
1da177e4
LT
986 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
987 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5be291fe 988 SCTP_PERR(SCTP_ERROR_NO_ERROR));
b01a2407
EB
989 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
990 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
1da177e4
LT
991 return SCTP_DISPOSITION_DELETE_TCB;
992 }
993
994 /* Section 3.3.5.
995 * The Sender-specific Heartbeat Info field should normally include
996 * information about the sender's current time when this HEARTBEAT
997 * chunk is sent and the destination transport address to which this
998 * HEARTBEAT is sent (see Section 8.3).
999 */
1000
52ccb8e9 1001 if (transport->param_flags & SPP_HB_ENABLE) {
1da177e4
LT
1002 if (SCTP_DISPOSITION_NOMEM ==
1003 sctp_sf_heartbeat(ep, asoc, type, arg,
1004 commands))
1005 return SCTP_DISPOSITION_NOMEM;
245cba7e 1006
1da177e4
LT
1007 /* Set transport error counter and association error counter
1008 * when sending heartbeat.
1009 */
7e99013a 1010 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_HB_SENT,
1da177e4
LT
1011 SCTP_TRANSPORT(transport));
1012 }
245cba7e
VY
1013 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_IDLE,
1014 SCTP_TRANSPORT(transport));
1da177e4
LT
1015 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMER_UPDATE,
1016 SCTP_TRANSPORT(transport));
1017
d808ad9a 1018 return SCTP_DISPOSITION_CONSUME;
1da177e4
LT
1019}
1020
1021/*
1022 * Process an heartbeat request.
1023 *
1024 * Section: 8.3 Path Heartbeat
1025 * The receiver of the HEARTBEAT should immediately respond with a
1026 * HEARTBEAT ACK that contains the Heartbeat Information field copied
1027 * from the received HEARTBEAT chunk.
1028 *
1029 * Verification Tag: 8.5 Verification Tag [Normal verification]
1030 * When receiving an SCTP packet, the endpoint MUST ensure that the
1031 * value in the Verification Tag field of the received SCTP packet
1032 * matches its own Tag. If the received Verification Tag value does not
1033 * match the receiver's own tag value, the receiver shall silently
1034 * discard the packet and shall not process it any further except for
1035 * those cases listed in Section 8.5.1 below.
1036 *
1037 * Inputs
1038 * (endpoint, asoc, chunk)
1039 *
1040 * Outputs
1041 * (asoc, reply_msg, msg_up, timers, counters)
1042 *
1043 * The return value is the disposition of the chunk.
1044 */
24cb81a6
EB
1045sctp_disposition_t sctp_sf_beat_8_3(struct net *net,
1046 const struct sctp_endpoint *ep,
1da177e4
LT
1047 const struct sctp_association *asoc,
1048 const sctp_subtype_t type,
1049 void *arg,
1050 sctp_cmd_seq_t *commands)
1051{
06a31e2b 1052 sctp_paramhdr_t *param_hdr;
1da177e4
LT
1053 struct sctp_chunk *chunk = arg;
1054 struct sctp_chunk *reply;
1055 size_t paylen = 0;
1056
1057 if (!sctp_vtag_verify(chunk, asoc))
24cb81a6 1058 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
1059
1060 /* Make sure that the HEARTBEAT chunk has a valid length. */
1061 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t)))
24cb81a6 1062 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4
LT
1063 commands);
1064
1065 /* 8.3 The receiver of the HEARTBEAT should immediately
1066 * respond with a HEARTBEAT ACK that contains the Heartbeat
1067 * Information field copied from the received HEARTBEAT chunk.
1068 */
1069 chunk->subh.hb_hdr = (sctp_heartbeathdr_t *) chunk->skb->data;
06a31e2b 1070 param_hdr = (sctp_paramhdr_t *) chunk->subh.hb_hdr;
1da177e4 1071 paylen = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
06a31e2b
TG
1072
1073 if (ntohs(param_hdr->length) > paylen)
1074 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
1075 param_hdr, commands);
1076
62b08083
SS
1077 if (!pskb_pull(chunk->skb, paylen))
1078 goto nomem;
1da177e4 1079
06a31e2b 1080 reply = sctp_make_heartbeat_ack(asoc, chunk, param_hdr, paylen);
1da177e4
LT
1081 if (!reply)
1082 goto nomem;
1083
1084 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
1085 return SCTP_DISPOSITION_CONSUME;
1086
1087nomem:
1088 return SCTP_DISPOSITION_NOMEM;
1089}
1090
1091/*
1092 * Process the returning HEARTBEAT ACK.
1093 *
1094 * Section: 8.3 Path Heartbeat
1095 * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT
1096 * should clear the error counter of the destination transport
1097 * address to which the HEARTBEAT was sent, and mark the destination
1098 * transport address as active if it is not so marked. The endpoint may
1099 * optionally report to the upper layer when an inactive destination
1100 * address is marked as active due to the reception of the latest
1101 * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also
1102 * clear the association overall error count as well (as defined
1103 * in section 8.1).
1104 *
1105 * The receiver of the HEARTBEAT ACK should also perform an RTT
1106 * measurement for that destination transport address using the time
1107 * value carried in the HEARTBEAT ACK chunk.
1108 *
1109 * Verification Tag: 8.5 Verification Tag [Normal verification]
1110 *
1111 * Inputs
1112 * (endpoint, asoc, chunk)
1113 *
1114 * Outputs
1115 * (asoc, reply_msg, msg_up, timers, counters)
1116 *
1117 * The return value is the disposition of the chunk.
1118 */
24cb81a6
EB
1119sctp_disposition_t sctp_sf_backbeat_8_3(struct net *net,
1120 const struct sctp_endpoint *ep,
1da177e4
LT
1121 const struct sctp_association *asoc,
1122 const sctp_subtype_t type,
1123 void *arg,
1124 sctp_cmd_seq_t *commands)
1125{
1126 struct sctp_chunk *chunk = arg;
1127 union sctp_addr from_addr;
1128 struct sctp_transport *link;
1129 sctp_sender_hb_info_t *hbinfo;
1130 unsigned long max_interval;
1131
1132 if (!sctp_vtag_verify(chunk, asoc))
24cb81a6 1133 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
1134
1135 /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */
dadb50cc
WY
1136 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t) +
1137 sizeof(sctp_sender_hb_info_t)))
24cb81a6 1138 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4
LT
1139 commands);
1140
1141 hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
a601266e
VY
1142 /* Make sure that the length of the parameter is what we expect */
1143 if (ntohs(hbinfo->param_hdr.length) !=
1144 sizeof(sctp_sender_hb_info_t)) {
1145 return SCTP_DISPOSITION_DISCARD;
1146 }
1147
1da177e4 1148 from_addr = hbinfo->daddr;
63de08f4 1149 link = sctp_assoc_lookup_paddr(asoc, &from_addr);
1da177e4
LT
1150
1151 /* This should never happen, but lets log it if so. */
3f7a87d2
FF
1152 if (unlikely(!link)) {
1153 if (from_addr.sa.sa_family == AF_INET6) {
e87cc472
JP
1154 net_warn_ratelimited("%s association %p could not find address %pI6\n",
1155 __func__,
1156 asoc,
1157 &from_addr.v6.sin6_addr);
3f7a87d2 1158 } else {
e87cc472
JP
1159 net_warn_ratelimited("%s association %p could not find address %pI4\n",
1160 __func__,
1161 asoc,
1162 &from_addr.v4.sin_addr.s_addr);
3f7a87d2 1163 }
1da177e4
LT
1164 return SCTP_DISPOSITION_DISCARD;
1165 }
1166
ad8fec17
SS
1167 /* Validate the 64-bit random nonce. */
1168 if (hbinfo->hb_nonce != link->hb_nonce)
1169 return SCTP_DISPOSITION_DISCARD;
1170
52ccb8e9 1171 max_interval = link->hbinterval + link->rto;
1da177e4
LT
1172
1173 /* Check if the timestamp looks valid. */
1174 if (time_after(hbinfo->sent_at, jiffies) ||
1175 time_after(jiffies, hbinfo->sent_at + max_interval)) {
bb33381d
DB
1176 pr_debug("%s: HEARTBEAT ACK with invalid timestamp received "
1177 "for transport:%p\n", __func__, link);
1178
1da177e4
LT
1179 return SCTP_DISPOSITION_DISCARD;
1180 }
1181
1182 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of
1183 * the HEARTBEAT should clear the error counter of the
1184 * destination transport address to which the HEARTBEAT was
1185 * sent and mark the destination transport address as active if
1186 * it is not so marked.
1187 */
1188 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_ON, SCTP_TRANSPORT(link));
1189
1190 return SCTP_DISPOSITION_CONSUME;
1191}
1192
1193/* Helper function to send out an abort for the restart
1194 * condition.
1195 */
2ce95503 1196static int sctp_sf_send_restart_abort(struct net *net, union sctp_addr *ssa,
1da177e4
LT
1197 struct sctp_chunk *init,
1198 sctp_cmd_seq_t *commands)
1199{
1200 int len;
1201 struct sctp_packet *pkt;
1202 union sctp_addr_param *addrparm;
1203 struct sctp_errhdr *errhdr;
1204 struct sctp_endpoint *ep;
1205 char buffer[sizeof(struct sctp_errhdr)+sizeof(union sctp_addr_param)];
1206 struct sctp_af *af = sctp_get_af_specific(ssa->v4.sin_family);
1207
1208 /* Build the error on the stack. We are way to malloc crazy
1209 * throughout the code today.
1210 */
1211 errhdr = (struct sctp_errhdr *)buffer;
1212 addrparm = (union sctp_addr_param *)errhdr->variable;
1213
1214 /* Copy into a parm format. */
1215 len = af->to_addr_param(ssa, addrparm);
1216 len += sizeof(sctp_errhdr_t);
1217
1218 errhdr->cause = SCTP_ERROR_RESTART;
1219 errhdr->length = htons(len);
1220
1221 /* Assign to the control socket. */
2ce95503 1222 ep = sctp_sk(net->sctp.ctl_sock)->ep;
1da177e4
LT
1223
1224 /* Association is NULL since this may be a restart attack and we
1225 * want to send back the attacker's vtag.
1226 */
24cb81a6 1227 pkt = sctp_abort_pkt_new(net, ep, NULL, init, errhdr, len);
1da177e4
LT
1228
1229 if (!pkt)
1230 goto out;
1231 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, SCTP_PACKET(pkt));
1232
b01a2407 1233 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
1da177e4
LT
1234
1235 /* Discard the rest of the inbound packet. */
1236 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
1237
1238out:
1239 /* Even if there is no memory, treat as a failure so
1240 * the packet will get dropped.
1241 */
1242 return 0;
1243}
1244
123031c0
JP
1245static bool list_has_sctp_addr(const struct list_head *list,
1246 union sctp_addr *ipaddr)
1247{
1248 struct sctp_transport *addr;
1249
1250 list_for_each_entry(addr, list, transports) {
1251 if (sctp_cmp_addr_exact(ipaddr, &addr->ipaddr))
1252 return true;
1253 }
1254
1255 return false;
1256}
1da177e4
LT
1257/* A restart is occurring, check to make sure no new addresses
1258 * are being added as we may be under a takeover attack.
1259 */
1260static int sctp_sf_check_restart_addrs(const struct sctp_association *new_asoc,
1261 const struct sctp_association *asoc,
1262 struct sctp_chunk *init,
1263 sctp_cmd_seq_t *commands)
1264{
2ce95503 1265 struct net *net = sock_net(new_asoc->base.sk);
123031c0
JP
1266 struct sctp_transport *new_addr;
1267 int ret = 1;
1da177e4 1268
123031c0 1269 /* Implementor's Guide - Section 5.2.2
1da177e4
LT
1270 * ...
1271 * Before responding the endpoint MUST check to see if the
1272 * unexpected INIT adds new addresses to the association. If new
1273 * addresses are added to the association, the endpoint MUST respond
1274 * with an ABORT..
1275 */
1276
1277 /* Search through all current addresses and make sure
1278 * we aren't adding any new ones.
1279 */
9dbc15f0 1280 list_for_each_entry(new_addr, &new_asoc->peer.transport_addr_list,
123031c0
JP
1281 transports) {
1282 if (!list_has_sctp_addr(&asoc->peer.transport_addr_list,
1283 &new_addr->ipaddr)) {
2ce95503 1284 sctp_sf_send_restart_abort(net, &new_addr->ipaddr, init,
123031c0
JP
1285 commands);
1286 ret = 0;
1da177e4 1287 break;
123031c0 1288 }
1da177e4
LT
1289 }
1290
1291 /* Return success if all addresses were found. */
123031c0 1292 return ret;
1da177e4
LT
1293}
1294
1295/* Populate the verification/tie tags based on overlapping INIT
1296 * scenario.
1297 *
1298 * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state.
1299 */
1300static void sctp_tietags_populate(struct sctp_association *new_asoc,
1301 const struct sctp_association *asoc)
1302{
1303 switch (asoc->state) {
1304
1305 /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */
1306
1307 case SCTP_STATE_COOKIE_WAIT:
1308 new_asoc->c.my_vtag = asoc->c.my_vtag;
1309 new_asoc->c.my_ttag = asoc->c.my_vtag;
1310 new_asoc->c.peer_ttag = 0;
1311 break;
1312
1313 case SCTP_STATE_COOKIE_ECHOED:
1314 new_asoc->c.my_vtag = asoc->c.my_vtag;
1315 new_asoc->c.my_ttag = asoc->c.my_vtag;
1316 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1317 break;
1318
1319 /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED,
1320 * COOKIE-WAIT and SHUTDOWN-ACK-SENT
1321 */
1322 default:
1323 new_asoc->c.my_ttag = asoc->c.my_vtag;
1324 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1325 break;
3ff50b79 1326 }
1da177e4
LT
1327
1328 /* Other parameters for the endpoint SHOULD be copied from the
1329 * existing parameters of the association (e.g. number of
1330 * outbound streams) into the INIT ACK and cookie.
1331 */
1332 new_asoc->rwnd = asoc->rwnd;
1333 new_asoc->c.sinit_num_ostreams = asoc->c.sinit_num_ostreams;
1334 new_asoc->c.sinit_max_instreams = asoc->c.sinit_max_instreams;
1335 new_asoc->c.initial_tsn = asoc->c.initial_tsn;
1336}
1337
1338/*
1339 * Compare vtag/tietag values to determine unexpected COOKIE-ECHO
1340 * handling action.
1341 *
1342 * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists.
1343 *
1344 * Returns value representing action to be taken. These action values
1345 * correspond to Action/Description values in RFC 2960, Table 2.
1346 */
1347static char sctp_tietags_compare(struct sctp_association *new_asoc,
1348 const struct sctp_association *asoc)
1349{
1350 /* In this case, the peer may have restarted. */
1351 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1352 (asoc->c.peer_vtag != new_asoc->c.peer_vtag) &&
1353 (asoc->c.my_vtag == new_asoc->c.my_ttag) &&
1354 (asoc->c.peer_vtag == new_asoc->c.peer_ttag))
1355 return 'A';
1356
1357 /* Collision case B. */
1358 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1359 ((asoc->c.peer_vtag != new_asoc->c.peer_vtag) ||
1360 (0 == asoc->c.peer_vtag))) {
1361 return 'B';
1362 }
1363
1364 /* Collision case D. */
1365 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1366 (asoc->c.peer_vtag == new_asoc->c.peer_vtag))
1367 return 'D';
1368
1369 /* Collision case C. */
1370 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1371 (asoc->c.peer_vtag == new_asoc->c.peer_vtag) &&
1372 (0 == new_asoc->c.my_ttag) &&
1373 (0 == new_asoc->c.peer_ttag))
1374 return 'C';
1375
1376 /* No match to any of the special cases; discard this packet. */
1377 return 'E';
1378}
1379
1380/* Common helper routine for both duplicate and simulataneous INIT
1381 * chunk handling.
1382 */
1383static sctp_disposition_t sctp_sf_do_unexpected_init(
24cb81a6 1384 struct net *net,
1da177e4
LT
1385 const struct sctp_endpoint *ep,
1386 const struct sctp_association *asoc,
1387 const sctp_subtype_t type,
1388 void *arg, sctp_cmd_seq_t *commands)
1389{
1390 sctp_disposition_t retval;
1391 struct sctp_chunk *chunk = arg;
1392 struct sctp_chunk *repl;
1393 struct sctp_association *new_asoc;
1394 struct sctp_chunk *err_chunk;
1395 struct sctp_packet *packet;
1396 sctp_unrecognized_param_t *unk_param;
1397 int len;
1398
1399 /* 6.10 Bundling
1400 * An endpoint MUST NOT bundle INIT, INIT ACK or
1401 * SHUTDOWN COMPLETE with any other chunks.
1402 *
1403 * IG Section 2.11.2
1404 * Furthermore, we require that the receiver of an INIT chunk MUST
1405 * enforce these rules by silently discarding an arriving packet
1406 * with an INIT chunk that is bundled with other chunks.
1407 */
1408 if (!chunk->singleton)
24cb81a6 1409 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
1410
1411 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
d808ad9a 1412 * Tag.
1da177e4
LT
1413 */
1414 if (chunk->sctp_hdr->vtag != 0)
24cb81a6 1415 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
1da177e4
LT
1416
1417 /* Make sure that the INIT chunk has a valid length.
1418 * In this case, we generate a protocol violation since we have
1419 * an association established.
1420 */
1421 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
24cb81a6 1422 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4
LT
1423 commands);
1424 /* Grab the INIT header. */
1425 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
1426
1427 /* Tag the variable length parameters. */
1428 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
1429
1430 /* Verify the INIT chunk before processing it. */
1431 err_chunk = NULL;
f53b5b09 1432 if (!sctp_verify_init(net, asoc, chunk->chunk_hdr->type,
1da177e4
LT
1433 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
1434 &err_chunk)) {
1435 /* This chunk contains fatal error. It is to be discarded.
1436 * Send an ABORT, with causes if there is any.
1437 */
1438 if (err_chunk) {
24cb81a6 1439 packet = sctp_abort_pkt_new(net, ep, asoc, arg,
1da177e4
LT
1440 (__u8 *)(err_chunk->chunk_hdr) +
1441 sizeof(sctp_chunkhdr_t),
1442 ntohs(err_chunk->chunk_hdr->length) -
1443 sizeof(sctp_chunkhdr_t));
1444
1445 if (packet) {
1446 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
1447 SCTP_PACKET(packet));
24cb81a6 1448 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
1da177e4
LT
1449 retval = SCTP_DISPOSITION_CONSUME;
1450 } else {
1451 retval = SCTP_DISPOSITION_NOMEM;
1452 }
1453 goto cleanup;
1454 } else {
24cb81a6 1455 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg,
1da177e4
LT
1456 commands);
1457 }
1458 }
1459
1460 /*
1461 * Other parameters for the endpoint SHOULD be copied from the
1462 * existing parameters of the association (e.g. number of
1463 * outbound streams) into the INIT ACK and cookie.
1464 * FIXME: We are copying parameters from the endpoint not the
1465 * association.
1466 */
1467 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
1468 if (!new_asoc)
1469 goto nomem;
1470
409b95af
VY
1471 if (sctp_assoc_set_bind_addr_from_ep(new_asoc,
1472 sctp_scope(sctp_source(chunk)), GFP_ATOMIC) < 0)
1473 goto nomem;
1474
1da177e4
LT
1475 /* In the outbound INIT ACK the endpoint MUST copy its current
1476 * Verification Tag and Peers Verification tag into a reserved
1477 * place (local tie-tag and per tie-tag) within the state cookie.
1478 */
de6becdc 1479 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk),
1da177e4 1480 (sctp_init_chunk_t *)chunk->chunk_hdr,
df7deeb5
VY
1481 GFP_ATOMIC))
1482 goto nomem;
1da177e4
LT
1483
1484 /* Make sure no new addresses are being added during the
1485 * restart. Do not do this check for COOKIE-WAIT state,
1486 * since there are no peer addresses to check against.
1487 * Upon return an ABORT will have been sent if needed.
1488 */
1489 if (!sctp_state(asoc, COOKIE_WAIT)) {
1490 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk,
1491 commands)) {
1492 retval = SCTP_DISPOSITION_CONSUME;
df7deeb5 1493 goto nomem_retval;
1da177e4
LT
1494 }
1495 }
1496
1497 sctp_tietags_populate(new_asoc, asoc);
1498
1499 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
1500
1501 /* If there are errors need to be reported for unknown parameters,
1502 * make sure to reserve enough room in the INIT ACK for them.
1503 */
1504 len = 0;
1505 if (err_chunk) {
1506 len = ntohs(err_chunk->chunk_hdr->length) -
1507 sizeof(sctp_chunkhdr_t);
1508 }
1509
1da177e4
LT
1510 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
1511 if (!repl)
1512 goto nomem;
1513
1514 /* If there are errors need to be reported for unknown parameters,
1515 * include them in the outgoing INIT ACK as "Unrecognized parameter"
1516 * parameter.
1517 */
1518 if (err_chunk) {
1519 /* Get the "Unrecognized parameter" parameter(s) out of the
1520 * ERROR chunk generated by sctp_verify_init(). Since the
1521 * error cause code for "unknown parameter" and the
1522 * "Unrecognized parameter" type is the same, we can
1523 * construct the parameters in INIT ACK by copying the
1524 * ERROR causes over.
1525 */
1526 unk_param = (sctp_unrecognized_param_t *)
1527 ((__u8 *)(err_chunk->chunk_hdr) +
1528 sizeof(sctp_chunkhdr_t));
1529 /* Replace the cause code with the "Unrecognized parameter"
1530 * parameter type.
1531 */
1532 sctp_addto_chunk(repl, len, unk_param);
1533 }
1534
1535 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
1536 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1537
1538 /*
1539 * Note: After sending out INIT ACK with the State Cookie parameter,
1540 * "Z" MUST NOT allocate any resources for this new association.
1541 * Otherwise, "Z" will be vulnerable to resource attacks.
1542 */
1543 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
1544 retval = SCTP_DISPOSITION_CONSUME;
1545
df7deeb5
VY
1546 return retval;
1547
1548nomem:
1549 retval = SCTP_DISPOSITION_NOMEM;
1550nomem_retval:
1551 if (new_asoc)
1552 sctp_association_free(new_asoc);
1da177e4
LT
1553cleanup:
1554 if (err_chunk)
1555 sctp_chunk_free(err_chunk);
1556 return retval;
1da177e4
LT
1557}
1558
1559/*
25985edc 1560 * Handle simultaneous INIT.
1da177e4
LT
1561 * This means we started an INIT and then we got an INIT request from
1562 * our peer.
1563 *
1564 * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B)
1565 * This usually indicates an initialization collision, i.e., each
1566 * endpoint is attempting, at about the same time, to establish an
1567 * association with the other endpoint.
1568 *
1569 * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an
1570 * endpoint MUST respond with an INIT ACK using the same parameters it
1571 * sent in its original INIT chunk (including its Verification Tag,
1572 * unchanged). These original parameters are combined with those from the
1573 * newly received INIT chunk. The endpoint shall also generate a State
1574 * Cookie with the INIT ACK. The endpoint uses the parameters sent in its
1575 * INIT to calculate the State Cookie.
1576 *
1577 * After that, the endpoint MUST NOT change its state, the T1-init
1578 * timer shall be left running and the corresponding TCB MUST NOT be
1579 * destroyed. The normal procedures for handling State Cookies when
1580 * a TCB exists will resolve the duplicate INITs to a single association.
1581 *
1582 * For an endpoint that is in the COOKIE-ECHOED state it MUST populate
1583 * its Tie-Tags with the Tag information of itself and its peer (see
1584 * section 5.2.2 for a description of the Tie-Tags).
1585 *
1586 * Verification Tag: Not explicit, but an INIT can not have a valid
1587 * verification tag, so we skip the check.
1588 *
1589 * Inputs
1590 * (endpoint, asoc, chunk)
1591 *
1592 * Outputs
1593 * (asoc, reply_msg, msg_up, timers, counters)
1594 *
1595 * The return value is the disposition of the chunk.
1596 */
24cb81a6
EB
1597sctp_disposition_t sctp_sf_do_5_2_1_siminit(struct net *net,
1598 const struct sctp_endpoint *ep,
1da177e4
LT
1599 const struct sctp_association *asoc,
1600 const sctp_subtype_t type,
1601 void *arg,
1602 sctp_cmd_seq_t *commands)
1603{
1604 /* Call helper to do the real work for both simulataneous and
1605 * duplicate INIT chunk handling.
1606 */
24cb81a6 1607 return sctp_sf_do_unexpected_init(net, ep, asoc, type, arg, commands);
1da177e4
LT
1608}
1609
1610/*
1611 * Handle duplicated INIT messages. These are usually delayed
1612 * restransmissions.
1613 *
1614 * Section: 5.2.2 Unexpected INIT in States Other than CLOSED,
1615 * COOKIE-ECHOED and COOKIE-WAIT
1616 *
1617 * Unless otherwise stated, upon reception of an unexpected INIT for
1618 * this association, the endpoint shall generate an INIT ACK with a
1619 * State Cookie. In the outbound INIT ACK the endpoint MUST copy its
1620 * current Verification Tag and peer's Verification Tag into a reserved
1621 * place within the state cookie. We shall refer to these locations as
1622 * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet
1623 * containing this INIT ACK MUST carry a Verification Tag value equal to
1624 * the Initiation Tag found in the unexpected INIT. And the INIT ACK
1625 * MUST contain a new Initiation Tag (randomly generated see Section
1626 * 5.3.1). Other parameters for the endpoint SHOULD be copied from the
1627 * existing parameters of the association (e.g. number of outbound
1628 * streams) into the INIT ACK and cookie.
1629 *
1630 * After sending out the INIT ACK, the endpoint shall take no further
1631 * actions, i.e., the existing association, including its current state,
1632 * and the corresponding TCB MUST NOT be changed.
1633 *
1634 * Note: Only when a TCB exists and the association is not in a COOKIE-
1635 * WAIT state are the Tie-Tags populated. For a normal association INIT
1636 * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be
1637 * set to 0 (indicating that no previous TCB existed). The INIT ACK and
1638 * State Cookie are populated as specified in section 5.2.1.
1639 *
1640 * Verification Tag: Not specified, but an INIT has no way of knowing
1641 * what the verification tag could be, so we ignore it.
1642 *
1643 * Inputs
1644 * (endpoint, asoc, chunk)
1645 *
1646 * Outputs
1647 * (asoc, reply_msg, msg_up, timers, counters)
1648 *
1649 * The return value is the disposition of the chunk.
1650 */
24cb81a6
EB
1651sctp_disposition_t sctp_sf_do_5_2_2_dupinit(struct net *net,
1652 const struct sctp_endpoint *ep,
1da177e4
LT
1653 const struct sctp_association *asoc,
1654 const sctp_subtype_t type,
1655 void *arg,
1656 sctp_cmd_seq_t *commands)
1657{
1658 /* Call helper to do the real work for both simulataneous and
1659 * duplicate INIT chunk handling.
1660 */
24cb81a6 1661 return sctp_sf_do_unexpected_init(net, ep, asoc, type, arg, commands);
1da177e4
LT
1662}
1663
1664
610ab73a
VY
1665/*
1666 * Unexpected INIT-ACK handler.
1667 *
1668 * Section 5.2.3
1669 * If an INIT ACK received by an endpoint in any state other than the
1670 * COOKIE-WAIT state, the endpoint should discard the INIT ACK chunk.
1671 * An unexpected INIT ACK usually indicates the processing of an old or
1672 * duplicated INIT chunk.
1673*/
24cb81a6
EB
1674sctp_disposition_t sctp_sf_do_5_2_3_initack(struct net *net,
1675 const struct sctp_endpoint *ep,
610ab73a
VY
1676 const struct sctp_association *asoc,
1677 const sctp_subtype_t type,
1678 void *arg, sctp_cmd_seq_t *commands)
1679{
1680 /* Per the above section, we'll discard the chunk if we have an
1681 * endpoint. If this is an OOTB INIT-ACK, treat it as such.
1682 */
2ce95503 1683 if (ep == sctp_sk(net->sctp.ctl_sock)->ep)
24cb81a6 1684 return sctp_sf_ootb(net, ep, asoc, type, arg, commands);
610ab73a 1685 else
24cb81a6 1686 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
610ab73a 1687}
1da177e4
LT
1688
1689/* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A')
1690 *
1691 * Section 5.2.4
1692 * A) In this case, the peer may have restarted.
1693 */
24cb81a6
EB
1694static sctp_disposition_t sctp_sf_do_dupcook_a(struct net *net,
1695 const struct sctp_endpoint *ep,
1da177e4
LT
1696 const struct sctp_association *asoc,
1697 struct sctp_chunk *chunk,
1698 sctp_cmd_seq_t *commands,
1699 struct sctp_association *new_asoc)
1700{
1701 sctp_init_chunk_t *peer_init;
1702 struct sctp_ulpevent *ev;
1703 struct sctp_chunk *repl;
1704 struct sctp_chunk *err;
1705 sctp_disposition_t disposition;
1706
1707 /* new_asoc is a brand-new association, so these are not yet
1708 * side effects--it is safe to run them here.
1709 */
1710 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1711
de6becdc 1712 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), peer_init,
1da177e4
LT
1713 GFP_ATOMIC))
1714 goto nomem;
1715
1716 /* Make sure no new addresses are being added during the
1717 * restart. Though this is a pretty complicated attack
1718 * since you'd have to get inside the cookie.
1719 */
1720 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk, commands)) {
1721 return SCTP_DISPOSITION_CONSUME;
1722 }
1723
1724 /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes
1725 * the peer has restarted (Action A), it MUST NOT setup a new
1726 * association but instead resend the SHUTDOWN ACK and send an ERROR
1727 * chunk with a "Cookie Received while Shutting Down" error cause to
1728 * its peer.
1729 */
1730 if (sctp_state(asoc, SHUTDOWN_ACK_SENT)) {
24cb81a6 1731 disposition = sctp_sf_do_9_2_reshutack(net, ep, asoc,
1da177e4
LT
1732 SCTP_ST_CHUNK(chunk->chunk_hdr->type),
1733 chunk, commands);
1734 if (SCTP_DISPOSITION_NOMEM == disposition)
1735 goto nomem;
1736
1737 err = sctp_make_op_error(asoc, chunk,
1738 SCTP_ERROR_COOKIE_IN_SHUTDOWN,
6383cfb3 1739 NULL, 0, 0);
1da177e4
LT
1740 if (err)
1741 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1742 SCTP_CHUNK(err));
1743
1744 return SCTP_DISPOSITION_CONSUME;
1745 }
1746
a000c01e
WY
1747 /* For now, stop pending T3-rtx and SACK timers, fail any unsent/unacked
1748 * data. Consider the optional choice of resending of this data.
1da177e4 1749 */
a000c01e
WY
1750 sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
1751 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1752 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
1da177e4
LT
1753 sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_OUTQUEUE, SCTP_NULL());
1754
a000c01e
WY
1755 /* Stop pending T4-rto timer, teardown ASCONF queue, ASCONF-ACK queue
1756 * and ASCONF-ACK cache.
1757 */
1758 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1759 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
1760 sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_ASCONF_QUEUE, SCTP_NULL());
1761
1da177e4
LT
1762 repl = sctp_make_cookie_ack(new_asoc, chunk);
1763 if (!repl)
1764 goto nomem;
1765
1da177e4
LT
1766 /* Report association restart to upper layer. */
1767 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_RESTART, 0,
1768 new_asoc->c.sinit_num_ostreams,
1769 new_asoc->c.sinit_max_instreams,
a5a35e76 1770 NULL, GFP_ATOMIC);
1da177e4
LT
1771 if (!ev)
1772 goto nomem_ev;
1773
df7deeb5
VY
1774 /* Update the content of current association. */
1775 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1da177e4 1776 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
9839ff0d
XZ
1777 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1778 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1779 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1da177e4
LT
1780 return SCTP_DISPOSITION_CONSUME;
1781
1782nomem_ev:
1783 sctp_chunk_free(repl);
1784nomem:
1785 return SCTP_DISPOSITION_NOMEM;
1786}
1787
1788/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B')
1789 *
1790 * Section 5.2.4
1791 * B) In this case, both sides may be attempting to start an association
1792 * at about the same time but the peer endpoint started its INIT
1793 * after responding to the local endpoint's INIT
1794 */
1795/* This case represents an initialization collision. */
24cb81a6
EB
1796static sctp_disposition_t sctp_sf_do_dupcook_b(struct net *net,
1797 const struct sctp_endpoint *ep,
1da177e4
LT
1798 const struct sctp_association *asoc,
1799 struct sctp_chunk *chunk,
1800 sctp_cmd_seq_t *commands,
1801 struct sctp_association *new_asoc)
1802{
1803 sctp_init_chunk_t *peer_init;
1da177e4
LT
1804 struct sctp_chunk *repl;
1805
1806 /* new_asoc is a brand-new association, so these are not yet
1807 * side effects--it is safe to run them here.
1808 */
1809 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
de6becdc 1810 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), peer_init,
1da177e4
LT
1811 GFP_ATOMIC))
1812 goto nomem;
1813
1814 /* Update the content of current association. */
1815 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1816 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1817 SCTP_STATE(SCTP_STATE_ESTABLISHED));
24cb81a6 1818 SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
1da177e4
LT
1819 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
1820
1821 repl = sctp_make_cookie_ack(new_asoc, chunk);
1822 if (!repl)
1823 goto nomem;
1824
1825 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1da177e4
LT
1826
1827 /* RFC 2960 5.1 Normal Establishment of an Association
1828 *
1829 * D) IMPLEMENTATION NOTE: An implementation may choose to
1830 * send the Communication Up notification to the SCTP user
1831 * upon reception of a valid COOKIE ECHO chunk.
07d93967
VY
1832 *
1833 * Sadly, this needs to be implemented as a side-effect, because
1834 * we are not guaranteed to have set the association id of the real
1835 * association and so these notifications need to be delayed until
1836 * the association id is allocated.
1da177e4 1837 */
1da177e4 1838
07d93967 1839 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_CHANGE, SCTP_U8(SCTP_COMM_UP));
1da177e4
LT
1840
1841 /* Sockets API Draft Section 5.3.1.6
0f3fffd8 1842 * When a peer sends a Adaptation Layer Indication parameter , SCTP
1da177e4 1843 * delivers this notification to inform the application that of the
0f3fffd8 1844 * peers requested adaptation layer.
07d93967
VY
1845 *
1846 * This also needs to be done as a side effect for the same reason as
1847 * above.
1da177e4 1848 */
07d93967
VY
1849 if (asoc->peer.adaptation_ind)
1850 sctp_add_cmd_sf(commands, SCTP_CMD_ADAPTATION_IND, SCTP_NULL());
1da177e4
LT
1851
1852 return SCTP_DISPOSITION_CONSUME;
1853
1da177e4
LT
1854nomem:
1855 return SCTP_DISPOSITION_NOMEM;
1856}
1857
1858/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C')
1859 *
1860 * Section 5.2.4
1861 * C) In this case, the local endpoint's cookie has arrived late.
1862 * Before it arrived, the local endpoint sent an INIT and received an
1863 * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag
1864 * but a new tag of its own.
1865 */
1866/* This case represents an initialization collision. */
24cb81a6
EB
1867static sctp_disposition_t sctp_sf_do_dupcook_c(struct net *net,
1868 const struct sctp_endpoint *ep,
1da177e4
LT
1869 const struct sctp_association *asoc,
1870 struct sctp_chunk *chunk,
1871 sctp_cmd_seq_t *commands,
1872 struct sctp_association *new_asoc)
1873{
1874 /* The cookie should be silently discarded.
1875 * The endpoint SHOULD NOT change states and should leave
1876 * any timers running.
1877 */
1878 return SCTP_DISPOSITION_DISCARD;
1879}
1880
1881/* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D')
1882 *
1883 * Section 5.2.4
1884 *
1885 * D) When both local and remote tags match the endpoint should always
1886 * enter the ESTABLISHED state, if it has not already done so.
1887 */
1888/* This case represents an initialization collision. */
24cb81a6
EB
1889static sctp_disposition_t sctp_sf_do_dupcook_d(struct net *net,
1890 const struct sctp_endpoint *ep,
1da177e4
LT
1891 const struct sctp_association *asoc,
1892 struct sctp_chunk *chunk,
1893 sctp_cmd_seq_t *commands,
1894 struct sctp_association *new_asoc)
1895{
df7deeb5 1896 struct sctp_ulpevent *ev = NULL, *ai_ev = NULL;
1da177e4
LT
1897 struct sctp_chunk *repl;
1898
1899 /* Clarification from Implementor's Guide:
1900 * D) When both local and remote tags match the endpoint should
d808ad9a
YH
1901 * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state.
1902 * It should stop any cookie timer that may be running and send
1903 * a COOKIE ACK.
1da177e4
LT
1904 */
1905
1906 /* Don't accidentally move back into established state. */
1907 if (asoc->state < SCTP_STATE_ESTABLISHED) {
1908 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1909 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1910 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1911 SCTP_STATE(SCTP_STATE_ESTABLISHED));
24cb81a6 1912 SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
1da177e4
LT
1913 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START,
1914 SCTP_NULL());
1915
1916 /* RFC 2960 5.1 Normal Establishment of an Association
1917 *
1918 * D) IMPLEMENTATION NOTE: An implementation may choose
1919 * to send the Communication Up notification to the
1920 * SCTP user upon reception of a valid COOKIE
1921 * ECHO chunk.
1922 */
df7deeb5 1923 ev = sctp_ulpevent_make_assoc_change(asoc, 0,
1da177e4 1924 SCTP_COMM_UP, 0,
df7deeb5
VY
1925 asoc->c.sinit_num_ostreams,
1926 asoc->c.sinit_max_instreams,
9cbcbf4e 1927 NULL, GFP_ATOMIC);
1da177e4
LT
1928 if (!ev)
1929 goto nomem;
1da177e4
LT
1930
1931 /* Sockets API Draft Section 5.3.1.6
0f3fffd8 1932 * When a peer sends a Adaptation Layer Indication parameter,
1da177e4 1933 * SCTP delivers this notification to inform the application
0f3fffd8 1934 * that of the peers requested adaptation layer.
1da177e4 1935 */
0f3fffd8
ISJ
1936 if (asoc->peer.adaptation_ind) {
1937 ai_ev = sctp_ulpevent_make_adaptation_indication(asoc,
1da177e4 1938 GFP_ATOMIC);
df7deeb5 1939 if (!ai_ev)
1da177e4
LT
1940 goto nomem;
1941
1da177e4
LT
1942 }
1943 }
1da177e4
LT
1944
1945 repl = sctp_make_cookie_ack(new_asoc, chunk);
1946 if (!repl)
1947 goto nomem;
1948
2e3216cd
VY
1949 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1950
df7deeb5
VY
1951 if (ev)
1952 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1953 SCTP_ULPEVENT(ev));
1954 if (ai_ev)
1955 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1956 SCTP_ULPEVENT(ai_ev));
1957
1da177e4
LT
1958 return SCTP_DISPOSITION_CONSUME;
1959
1960nomem:
df7deeb5
VY
1961 if (ai_ev)
1962 sctp_ulpevent_free(ai_ev);
1da177e4
LT
1963 if (ev)
1964 sctp_ulpevent_free(ev);
1965 return SCTP_DISPOSITION_NOMEM;
1966}
1967
1968/*
1969 * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying
1970 * chunk was retransmitted and then delayed in the network.
1971 *
1972 * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists
1973 *
1974 * Verification Tag: None. Do cookie validation.
1975 *
1976 * Inputs
1977 * (endpoint, asoc, chunk)
1978 *
1979 * Outputs
1980 * (asoc, reply_msg, msg_up, timers, counters)
1981 *
1982 * The return value is the disposition of the chunk.
1983 */
24cb81a6
EB
1984sctp_disposition_t sctp_sf_do_5_2_4_dupcook(struct net *net,
1985 const struct sctp_endpoint *ep,
1da177e4
LT
1986 const struct sctp_association *asoc,
1987 const sctp_subtype_t type,
1988 void *arg,
1989 sctp_cmd_seq_t *commands)
1990{
1991 sctp_disposition_t retval;
1992 struct sctp_chunk *chunk = arg;
1993 struct sctp_association *new_asoc;
1994 int error = 0;
1995 char action;
1996 struct sctp_chunk *err_chk_p;
1997
1998 /* Make sure that the chunk has a valid length from the protocol
1999 * perspective. In this case check to make sure we have at least
2000 * enough for the chunk header. Cookie length verification is
2001 * done later.
2002 */
2003 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
24cb81a6 2004 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4
LT
2005 commands);
2006
2007 /* "Decode" the chunk. We have no optional parameters so we
2008 * are in good shape.
2009 */
d808ad9a 2010 chunk->subh.cookie_hdr = (struct sctp_signed_cookie *)chunk->skb->data;
62b08083
SS
2011 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
2012 sizeof(sctp_chunkhdr_t)))
2013 goto nomem;
1da177e4
LT
2014
2015 /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
2016 * of a duplicate COOKIE ECHO match the Verification Tags of the
2017 * current association, consider the State Cookie valid even if
2018 * the lifespan is exceeded.
2019 */
2020 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
2021 &err_chk_p);
2022
2023 /* FIXME:
2024 * If the re-build failed, what is the proper error path
2025 * from here?
2026 *
2027 * [We should abort the association. --piggy]
2028 */
2029 if (!new_asoc) {
2030 /* FIXME: Several errors are possible. A bad cookie should
2031 * be silently discarded, but think about logging it too.
2032 */
2033 switch (error) {
2034 case -SCTP_IERROR_NOMEM:
2035 goto nomem;
2036
2037 case -SCTP_IERROR_STALE_COOKIE:
24cb81a6 2038 sctp_send_stale_cookie_err(net, ep, asoc, chunk, commands,
1da177e4 2039 err_chk_p);
24cb81a6 2040 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
2041 case -SCTP_IERROR_BAD_SIG:
2042 default:
24cb81a6 2043 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3ff50b79 2044 }
1da177e4
LT
2045 }
2046
2047 /* Compare the tie_tag in cookie with the verification tag of
2048 * current association.
2049 */
2050 action = sctp_tietags_compare(new_asoc, asoc);
2051
2052 switch (action) {
2053 case 'A': /* Association restart. */
24cb81a6 2054 retval = sctp_sf_do_dupcook_a(net, ep, asoc, chunk, commands,
1da177e4
LT
2055 new_asoc);
2056 break;
2057
2058 case 'B': /* Collision case B. */
24cb81a6 2059 retval = sctp_sf_do_dupcook_b(net, ep, asoc, chunk, commands,
1da177e4
LT
2060 new_asoc);
2061 break;
2062
2063 case 'C': /* Collision case C. */
24cb81a6 2064 retval = sctp_sf_do_dupcook_c(net, ep, asoc, chunk, commands,
1da177e4
LT
2065 new_asoc);
2066 break;
2067
2068 case 'D': /* Collision case D. */
24cb81a6 2069 retval = sctp_sf_do_dupcook_d(net, ep, asoc, chunk, commands,
1da177e4
LT
2070 new_asoc);
2071 break;
2072
2073 default: /* Discard packet for all others. */
24cb81a6 2074 retval = sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4 2075 break;
3ff50b79 2076 }
1da177e4
LT
2077
2078 /* Delete the tempory new association. */
f2815633 2079 sctp_add_cmd_sf(commands, SCTP_CMD_SET_ASOC, SCTP_ASOC(new_asoc));
1da177e4
LT
2080 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
2081
d5ccd496
MM
2082 /* Restore association pointer to provide SCTP command interpeter
2083 * with a valid context in case it needs to manipulate
2084 * the queues */
2085 sctp_add_cmd_sf(commands, SCTP_CMD_SET_ASOC,
2086 SCTP_ASOC((struct sctp_association *)asoc));
2087
1da177e4
LT
2088 return retval;
2089
2090nomem:
2091 return SCTP_DISPOSITION_NOMEM;
2092}
2093
2094/*
2095 * Process an ABORT. (SHUTDOWN-PENDING state)
2096 *
2097 * See sctp_sf_do_9_1_abort().
2098 */
2099sctp_disposition_t sctp_sf_shutdown_pending_abort(
24cb81a6 2100 struct net *net,
1da177e4
LT
2101 const struct sctp_endpoint *ep,
2102 const struct sctp_association *asoc,
2103 const sctp_subtype_t type,
2104 void *arg,
2105 sctp_cmd_seq_t *commands)
2106{
2107 struct sctp_chunk *chunk = arg;
2108
2109 if (!sctp_vtag_verify_either(chunk, asoc))
24cb81a6 2110 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
2111
2112 /* Make sure that the ABORT chunk has a valid length.
2113 * Since this is an ABORT chunk, we have to discard it
2114 * because of the following text:
2115 * RFC 2960, Section 3.3.7
2116 * If an endpoint receives an ABORT with a format error or for an
2117 * association that doesn't exist, it MUST silently discard it.
25985edc 2118 * Because the length is "invalid", we can't really discard just
1da177e4
LT
2119 * as we do not know its true length. So, to be safe, discard the
2120 * packet.
2121 */
2122 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
24cb81a6 2123 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4 2124
75205f47
VY
2125 /* ADD-IP: Special case for ABORT chunks
2126 * F4) One special consideration is that ABORT Chunks arriving
2127 * destined to the IP address being deleted MUST be
2128 * ignored (see Section 5.3.1 for further details).
2129 */
2130 if (SCTP_ADDR_DEL ==
2131 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
24cb81a6 2132 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
75205f47 2133
24cb81a6 2134 return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands);
1da177e4
LT
2135}
2136
2137/*
2138 * Process an ABORT. (SHUTDOWN-SENT state)
2139 *
2140 * See sctp_sf_do_9_1_abort().
2141 */
24cb81a6
EB
2142sctp_disposition_t sctp_sf_shutdown_sent_abort(struct net *net,
2143 const struct sctp_endpoint *ep,
1da177e4
LT
2144 const struct sctp_association *asoc,
2145 const sctp_subtype_t type,
2146 void *arg,
2147 sctp_cmd_seq_t *commands)
2148{
2149 struct sctp_chunk *chunk = arg;
2150
2151 if (!sctp_vtag_verify_either(chunk, asoc))
24cb81a6 2152 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
2153
2154 /* Make sure that the ABORT chunk has a valid length.
2155 * Since this is an ABORT chunk, we have to discard it
2156 * because of the following text:
2157 * RFC 2960, Section 3.3.7
2158 * If an endpoint receives an ABORT with a format error or for an
2159 * association that doesn't exist, it MUST silently discard it.
25985edc 2160 * Because the length is "invalid", we can't really discard just
1da177e4
LT
2161 * as we do not know its true length. So, to be safe, discard the
2162 * packet.
2163 */
2164 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
24cb81a6 2165 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4 2166
75205f47
VY
2167 /* ADD-IP: Special case for ABORT chunks
2168 * F4) One special consideration is that ABORT Chunks arriving
2169 * destined to the IP address being deleted MUST be
2170 * ignored (see Section 5.3.1 for further details).
2171 */
2172 if (SCTP_ADDR_DEL ==
2173 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
24cb81a6 2174 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
75205f47 2175
1da177e4
LT
2176 /* Stop the T2-shutdown timer. */
2177 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2178 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2179
2180 /* Stop the T5-shutdown guard timer. */
2181 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2182 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
2183
24cb81a6 2184 return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands);
1da177e4
LT
2185}
2186
2187/*
2188 * Process an ABORT. (SHUTDOWN-ACK-SENT state)
2189 *
2190 * See sctp_sf_do_9_1_abort().
2191 */
2192sctp_disposition_t sctp_sf_shutdown_ack_sent_abort(
24cb81a6 2193 struct net *net,
1da177e4
LT
2194 const struct sctp_endpoint *ep,
2195 const struct sctp_association *asoc,
2196 const sctp_subtype_t type,
2197 void *arg,
2198 sctp_cmd_seq_t *commands)
2199{
2200 /* The same T2 timer, so we should be able to use
2201 * common function with the SHUTDOWN-SENT state.
2202 */
24cb81a6 2203 return sctp_sf_shutdown_sent_abort(net, ep, asoc, type, arg, commands);
1da177e4
LT
2204}
2205
2206/*
2207 * Handle an Error received in COOKIE_ECHOED state.
2208 *
2209 * Only handle the error type of stale COOKIE Error, the other errors will
2210 * be ignored.
2211 *
2212 * Inputs
2213 * (endpoint, asoc, chunk)
2214 *
2215 * Outputs
2216 * (asoc, reply_msg, msg_up, timers, counters)
2217 *
2218 * The return value is the disposition of the chunk.
2219 */
24cb81a6
EB
2220sctp_disposition_t sctp_sf_cookie_echoed_err(struct net *net,
2221 const struct sctp_endpoint *ep,
1da177e4
LT
2222 const struct sctp_association *asoc,
2223 const sctp_subtype_t type,
2224 void *arg,
2225 sctp_cmd_seq_t *commands)
2226{
2227 struct sctp_chunk *chunk = arg;
2228 sctp_errhdr_t *err;
2229
2230 if (!sctp_vtag_verify(chunk, asoc))
24cb81a6 2231 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
2232
2233 /* Make sure that the ERROR chunk has a valid length.
2234 * The parameter walking depends on this as well.
2235 */
2236 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
24cb81a6 2237 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4
LT
2238 commands);
2239
2240 /* Process the error here */
2241 /* FUTURE FIXME: When PR-SCTP related and other optional
2242 * parms are emitted, this will have to change to handle multiple
2243 * errors.
2244 */
2245 sctp_walk_errors(err, chunk->chunk_hdr) {
2246 if (SCTP_ERROR_STALE_COOKIE == err->cause)
24cb81a6 2247 return sctp_sf_do_5_2_6_stale(net, ep, asoc, type,
1da177e4
LT
2248 arg, commands);
2249 }
2250
2251 /* It is possible to have malformed error causes, and that
2252 * will cause us to end the walk early. However, since
2253 * we are discarding the packet, there should be no adverse
2254 * affects.
2255 */
24cb81a6 2256 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
2257}
2258
2259/*
2260 * Handle a Stale COOKIE Error
2261 *
2262 * Section: 5.2.6 Handle Stale COOKIE Error
2263 * If the association is in the COOKIE-ECHOED state, the endpoint may elect
2264 * one of the following three alternatives.
2265 * ...
2266 * 3) Send a new INIT chunk to the endpoint, adding a Cookie
2267 * Preservative parameter requesting an extension to the lifetime of
2268 * the State Cookie. When calculating the time extension, an
2269 * implementation SHOULD use the RTT information measured based on the
2270 * previous COOKIE ECHO / ERROR exchange, and should add no more
2271 * than 1 second beyond the measured RTT, due to long State Cookie
2272 * lifetimes making the endpoint more subject to a replay attack.
2273 *
2274 * Verification Tag: Not explicit, but safe to ignore.
2275 *
2276 * Inputs
2277 * (endpoint, asoc, chunk)
2278 *
2279 * Outputs
2280 * (asoc, reply_msg, msg_up, timers, counters)
2281 *
2282 * The return value is the disposition of the chunk.
2283 */
24cb81a6
EB
2284static sctp_disposition_t sctp_sf_do_5_2_6_stale(struct net *net,
2285 const struct sctp_endpoint *ep,
1da177e4
LT
2286 const struct sctp_association *asoc,
2287 const sctp_subtype_t type,
2288 void *arg,
2289 sctp_cmd_seq_t *commands)
2290{
2291 struct sctp_chunk *chunk = arg;
2292 time_t stale;
2293 sctp_cookie_preserve_param_t bht;
2294 sctp_errhdr_t *err;
2295 struct sctp_chunk *reply;
2296 struct sctp_bind_addr *bp;
3f7a87d2 2297 int attempts = asoc->init_err_counter + 1;
1da177e4 2298
81845c21 2299 if (attempts > asoc->max_init_attempts) {
8de8c873
SS
2300 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
2301 SCTP_ERROR(ETIMEDOUT));
1da177e4 2302 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
dc251b2b 2303 SCTP_PERR(SCTP_ERROR_STALE_COOKIE));
1da177e4
LT
2304 return SCTP_DISPOSITION_DELETE_TCB;
2305 }
2306
2307 err = (sctp_errhdr_t *)(chunk->skb->data);
2308
2309 /* When calculating the time extension, an implementation
2310 * SHOULD use the RTT information measured based on the
2311 * previous COOKIE ECHO / ERROR exchange, and should add no
2312 * more than 1 second beyond the measured RTT, due to long
2313 * State Cookie lifetimes making the endpoint more subject to
2314 * a replay attack.
2315 * Measure of Staleness's unit is usec. (1/1000000 sec)
2316 * Suggested Cookie Life-span Increment's unit is msec.
2317 * (1/1000 sec)
2318 * In general, if you use the suggested cookie life, the value
2319 * found in the field of measure of staleness should be doubled
2320 * to give ample time to retransmit the new cookie and thus
2321 * yield a higher probability of success on the reattempt.
2322 */
34bcca28 2323 stale = ntohl(*(__be32 *)((u8 *)err + sizeof(sctp_errhdr_t)));
1da177e4
LT
2324 stale = (stale * 2) / 1000;
2325
2326 bht.param_hdr.type = SCTP_PARAM_COOKIE_PRESERVATIVE;
2327 bht.param_hdr.length = htons(sizeof(bht));
2328 bht.lifespan_increment = htonl(stale);
2329
2330 /* Build that new INIT chunk. */
2331 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
2332 reply = sctp_make_init(asoc, bp, GFP_ATOMIC, sizeof(bht));
2333 if (!reply)
2334 goto nomem;
2335
2336 sctp_addto_chunk(reply, sizeof(bht), &bht);
2337
2338 /* Clear peer's init_tag cached in assoc as we are sending a new INIT */
2339 sctp_add_cmd_sf(commands, SCTP_CMD_CLEAR_INIT_TAG, SCTP_NULL());
2340
2341 /* Stop pending T3-rtx and heartbeat timers */
2342 sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
2343 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
2344
2345 /* Delete non-primary peer ip addresses since we are transitioning
2346 * back to the COOKIE-WAIT state
2347 */
2348 sctp_add_cmd_sf(commands, SCTP_CMD_DEL_NON_PRIMARY, SCTP_NULL());
2349
d808ad9a
YH
2350 /* If we've sent any data bundled with COOKIE-ECHO we will need to
2351 * resend
1da177e4 2352 */
b6157d8e 2353 sctp_add_cmd_sf(commands, SCTP_CMD_T1_RETRAN,
1da177e4
LT
2354 SCTP_TRANSPORT(asoc->peer.primary_path));
2355
2356 /* Cast away the const modifier, as we want to just
2357 * rerun it through as a sideffect.
2358 */
3f7a87d2 2359 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_INC, SCTP_NULL());
1da177e4
LT
2360
2361 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2362 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
2363 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2364 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
2365 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
2366 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
2367
2368 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2369
2370 return SCTP_DISPOSITION_CONSUME;
2371
2372nomem:
2373 return SCTP_DISPOSITION_NOMEM;
2374}
2375
2376/*
2377 * Process an ABORT.
2378 *
2379 * Section: 9.1
2380 * After checking the Verification Tag, the receiving endpoint shall
2381 * remove the association from its record, and shall report the
2382 * termination to its upper layer.
2383 *
2384 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
2385 * B) Rules for packet carrying ABORT:
2386 *
2387 * - The endpoint shall always fill in the Verification Tag field of the
2388 * outbound packet with the destination endpoint's tag value if it
2389 * is known.
2390 *
2391 * - If the ABORT is sent in response to an OOTB packet, the endpoint
2392 * MUST follow the procedure described in Section 8.4.
2393 *
2394 * - The receiver MUST accept the packet if the Verification Tag
2395 * matches either its own tag, OR the tag of its peer. Otherwise, the
2396 * receiver MUST silently discard the packet and take no further
2397 * action.
2398 *
2399 * Inputs
2400 * (endpoint, asoc, chunk)
2401 *
2402 * Outputs
2403 * (asoc, reply_msg, msg_up, timers, counters)
2404 *
2405 * The return value is the disposition of the chunk.
2406 */
24cb81a6
EB
2407sctp_disposition_t sctp_sf_do_9_1_abort(struct net *net,
2408 const struct sctp_endpoint *ep,
1da177e4
LT
2409 const struct sctp_association *asoc,
2410 const sctp_subtype_t type,
2411 void *arg,
2412 sctp_cmd_seq_t *commands)
2413{
2414 struct sctp_chunk *chunk = arg;
1da177e4
LT
2415
2416 if (!sctp_vtag_verify_either(chunk, asoc))
24cb81a6 2417 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
2418
2419 /* Make sure that the ABORT chunk has a valid length.
2420 * Since this is an ABORT chunk, we have to discard it
2421 * because of the following text:
2422 * RFC 2960, Section 3.3.7
2423 * If an endpoint receives an ABORT with a format error or for an
2424 * association that doesn't exist, it MUST silently discard it.
25985edc 2425 * Because the length is "invalid", we can't really discard just
1da177e4
LT
2426 * as we do not know its true length. So, to be safe, discard the
2427 * packet.
2428 */
2429 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
24cb81a6 2430 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4 2431
75205f47
VY
2432 /* ADD-IP: Special case for ABORT chunks
2433 * F4) One special consideration is that ABORT Chunks arriving
2434 * destined to the IP address being deleted MUST be
2435 * ignored (see Section 5.3.1 for further details).
2436 */
2437 if (SCTP_ADDR_DEL ==
2438 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
24cb81a6 2439 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
75205f47 2440
24cb81a6 2441 return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands);
75205f47
VY
2442}
2443
24cb81a6
EB
2444static sctp_disposition_t __sctp_sf_do_9_1_abort(struct net *net,
2445 const struct sctp_endpoint *ep,
75205f47
VY
2446 const struct sctp_association *asoc,
2447 const sctp_subtype_t type,
2448 void *arg,
2449 sctp_cmd_seq_t *commands)
2450{
2451 struct sctp_chunk *chunk = arg;
95c96174 2452 unsigned int len;
75205f47
VY
2453 __be16 error = SCTP_ERROR_NO_ERROR;
2454
1da177e4
LT
2455 /* See if we have an error cause code in the chunk. */
2456 len = ntohs(chunk->chunk_hdr->length);
96ca468b
SW
2457 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr)) {
2458
2459 sctp_errhdr_t *err;
2460 sctp_walk_errors(err, chunk->chunk_hdr);
2461 if ((void *)err != (void *)chunk->chunk_end)
24cb81a6 2462 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
96ca468b 2463
1da177e4 2464 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
96ca468b 2465 }
1da177e4 2466
8de8c873 2467 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNRESET));
d808ad9a 2468 /* ASSOC_FAILED will DELETE_TCB. */
5be291fe 2469 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, SCTP_PERR(error));
b01a2407
EB
2470 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
2471 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
1da177e4
LT
2472
2473 return SCTP_DISPOSITION_ABORT;
2474}
2475
2476/*
2477 * Process an ABORT. (COOKIE-WAIT state)
2478 *
2479 * See sctp_sf_do_9_1_abort() above.
2480 */
24cb81a6
EB
2481sctp_disposition_t sctp_sf_cookie_wait_abort(struct net *net,
2482 const struct sctp_endpoint *ep,
1da177e4
LT
2483 const struct sctp_association *asoc,
2484 const sctp_subtype_t type,
2485 void *arg,
2486 sctp_cmd_seq_t *commands)
2487{
2488 struct sctp_chunk *chunk = arg;
95c96174 2489 unsigned int len;
f94c0198 2490 __be16 error = SCTP_ERROR_NO_ERROR;
1da177e4
LT
2491
2492 if (!sctp_vtag_verify_either(chunk, asoc))
24cb81a6 2493 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
2494
2495 /* Make sure that the ABORT chunk has a valid length.
2496 * Since this is an ABORT chunk, we have to discard it
2497 * because of the following text:
2498 * RFC 2960, Section 3.3.7
2499 * If an endpoint receives an ABORT with a format error or for an
2500 * association that doesn't exist, it MUST silently discard it.
25985edc 2501 * Because the length is "invalid", we can't really discard just
1da177e4
LT
2502 * as we do not know its true length. So, to be safe, discard the
2503 * packet.
2504 */
2505 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
24cb81a6 2506 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
2507
2508 /* See if we have an error cause code in the chunk. */
2509 len = ntohs(chunk->chunk_hdr->length);
2510 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
2511 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2512
24cb81a6 2513 return sctp_stop_t1_and_abort(net, commands, error, ECONNREFUSED, asoc,
8de8c873 2514 chunk->transport);
1da177e4
LT
2515}
2516
2517/*
2518 * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state)
2519 */
24cb81a6
EB
2520sctp_disposition_t sctp_sf_cookie_wait_icmp_abort(struct net *net,
2521 const struct sctp_endpoint *ep,
1da177e4
LT
2522 const struct sctp_association *asoc,
2523 const sctp_subtype_t type,
2524 void *arg,
2525 sctp_cmd_seq_t *commands)
2526{
24cb81a6 2527 return sctp_stop_t1_and_abort(net, commands, SCTP_ERROR_NO_ERROR,
8de8c873 2528 ENOPROTOOPT, asoc,
3f7a87d2 2529 (struct sctp_transport *)arg);
1da177e4
LT
2530}
2531
2532/*
2533 * Process an ABORT. (COOKIE-ECHOED state)
2534 */
24cb81a6
EB
2535sctp_disposition_t sctp_sf_cookie_echoed_abort(struct net *net,
2536 const struct sctp_endpoint *ep,
1da177e4
LT
2537 const struct sctp_association *asoc,
2538 const sctp_subtype_t type,
2539 void *arg,
2540 sctp_cmd_seq_t *commands)
2541{
2542 /* There is a single T1 timer, so we should be able to use
2543 * common function with the COOKIE-WAIT state.
2544 */
24cb81a6 2545 return sctp_sf_cookie_wait_abort(net, ep, asoc, type, arg, commands);
1da177e4
LT
2546}
2547
2548/*
2549 * Stop T1 timer and abort association with "INIT failed".
2550 *
2551 * This is common code called by several sctp_sf_*_abort() functions above.
2552 */
24cb81a6
EB
2553static sctp_disposition_t sctp_stop_t1_and_abort(struct net *net,
2554 sctp_cmd_seq_t *commands,
f94c0198 2555 __be16 error, int sk_err,
3f7a87d2
FF
2556 const struct sctp_association *asoc,
2557 struct sctp_transport *transport)
1da177e4 2558{
bb33381d
DB
2559 pr_debug("%s: ABORT received (INIT)\n", __func__);
2560
1da177e4
LT
2561 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2562 SCTP_STATE(SCTP_STATE_CLOSED));
24cb81a6 2563 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
1da177e4
LT
2564 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2565 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
8de8c873 2566 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(sk_err));
1da177e4
LT
2567 /* CMD_INIT_FAILED will DELETE_TCB. */
2568 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
dc251b2b 2569 SCTP_PERR(error));
bb33381d 2570
3f7a87d2 2571 return SCTP_DISPOSITION_ABORT;
1da177e4
LT
2572}
2573
2574/*
2575 * sctp_sf_do_9_2_shut
2576 *
2577 * Section: 9.2
2578 * Upon the reception of the SHUTDOWN, the peer endpoint shall
2579 * - enter the SHUTDOWN-RECEIVED state,
2580 *
2581 * - stop accepting new data from its SCTP user
2582 *
2583 * - verify, by checking the Cumulative TSN Ack field of the chunk,
2584 * that all its outstanding DATA chunks have been received by the
2585 * SHUTDOWN sender.
2586 *
2587 * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT
2588 * send a SHUTDOWN in response to a ULP request. And should discard
2589 * subsequent SHUTDOWN chunks.
2590 *
2591 * If there are still outstanding DATA chunks left, the SHUTDOWN
2592 * receiver shall continue to follow normal data transmission
2593 * procedures defined in Section 6 until all outstanding DATA chunks
2594 * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept
2595 * new data from its SCTP user.
2596 *
2597 * Verification Tag: 8.5 Verification Tag [Normal verification]
2598 *
2599 * Inputs
2600 * (endpoint, asoc, chunk)
2601 *
2602 * Outputs
2603 * (asoc, reply_msg, msg_up, timers, counters)
2604 *
2605 * The return value is the disposition of the chunk.
2606 */
24cb81a6
EB
2607sctp_disposition_t sctp_sf_do_9_2_shutdown(struct net *net,
2608 const struct sctp_endpoint *ep,
1da177e4
LT
2609 const struct sctp_association *asoc,
2610 const sctp_subtype_t type,
2611 void *arg,
2612 sctp_cmd_seq_t *commands)
2613{
2614 struct sctp_chunk *chunk = arg;
2615 sctp_shutdownhdr_t *sdh;
2616 sctp_disposition_t disposition;
2617 struct sctp_ulpevent *ev;
df10eec4 2618 __u32 ctsn;
1da177e4
LT
2619
2620 if (!sctp_vtag_verify(chunk, asoc))
24cb81a6 2621 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
2622
2623 /* Make sure that the SHUTDOWN chunk has a valid length. */
2624 if (!sctp_chunk_length_valid(chunk,
2625 sizeof(struct sctp_shutdown_chunk_t)))
24cb81a6 2626 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4
LT
2627 commands);
2628
2629 /* Convert the elaborate header. */
2630 sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
2631 skb_pull(chunk->skb, sizeof(sctp_shutdownhdr_t));
2632 chunk->subh.shutdown_hdr = sdh;
df10eec4
WY
2633 ctsn = ntohl(sdh->cum_tsn_ack);
2634
a2f36eec 2635 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
bb33381d
DB
2636 pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn,
2637 asoc->ctsn_ack_point);
2638
a2f36eec
WY
2639 return SCTP_DISPOSITION_DISCARD;
2640 }
2641
df10eec4
WY
2642 /* If Cumulative TSN Ack beyond the max tsn currently
2643 * send, terminating the association and respond to the
2644 * sender with an ABORT.
2645 */
2646 if (!TSN_lt(ctsn, asoc->next_tsn))
24cb81a6 2647 return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands);
1da177e4 2648
eb0e0076
SS
2649 /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT
2650 * When a peer sends a SHUTDOWN, SCTP delivers this notification to
2651 * inform the application that it should cease sending data.
2652 */
2653 ev = sctp_ulpevent_make_shutdown_event(asoc, 0, GFP_ATOMIC);
2654 if (!ev) {
2655 disposition = SCTP_DISPOSITION_NOMEM;
d808ad9a 2656 goto out;
eb0e0076
SS
2657 }
2658 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
2659
1da177e4
LT
2660 /* Upon the reception of the SHUTDOWN, the peer endpoint shall
2661 * - enter the SHUTDOWN-RECEIVED state,
2662 * - stop accepting new data from its SCTP user
2663 *
2664 * [This is implicit in the new state.]
2665 */
2666 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2667 SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED));
2668 disposition = SCTP_DISPOSITION_CONSUME;
2669
2670 if (sctp_outq_is_empty(&asoc->outqueue)) {
24cb81a6 2671 disposition = sctp_sf_do_9_2_shutdown_ack(net, ep, asoc, type,
1da177e4
LT
2672 arg, commands);
2673 }
2674
2675 if (SCTP_DISPOSITION_NOMEM == disposition)
2676 goto out;
2677
2678 /* - verify, by checking the Cumulative TSN Ack field of the
2679 * chunk, that all its outstanding DATA chunks have been
2680 * received by the SHUTDOWN sender.
2681 */
2682 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
2178eda8 2683 SCTP_BE32(chunk->subh.shutdown_hdr->cum_tsn_ack));
1da177e4 2684
1da177e4
LT
2685out:
2686 return disposition;
2687}
2688
2e3f92da
WY
2689/*
2690 * sctp_sf_do_9_2_shut_ctsn
2691 *
2692 * Once an endpoint has reached the SHUTDOWN-RECEIVED state,
2693 * it MUST NOT send a SHUTDOWN in response to a ULP request.
2694 * The Cumulative TSN Ack of the received SHUTDOWN chunk
2695 * MUST be processed.
2696 */
24cb81a6
EB
2697sctp_disposition_t sctp_sf_do_9_2_shut_ctsn(struct net *net,
2698 const struct sctp_endpoint *ep,
2e3f92da
WY
2699 const struct sctp_association *asoc,
2700 const sctp_subtype_t type,
2701 void *arg,
2702 sctp_cmd_seq_t *commands)
2703{
2704 struct sctp_chunk *chunk = arg;
2705 sctp_shutdownhdr_t *sdh;
a2f36eec 2706 __u32 ctsn;
2e3f92da
WY
2707
2708 if (!sctp_vtag_verify(chunk, asoc))
24cb81a6 2709 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2e3f92da
WY
2710
2711 /* Make sure that the SHUTDOWN chunk has a valid length. */
2712 if (!sctp_chunk_length_valid(chunk,
2713 sizeof(struct sctp_shutdown_chunk_t)))
24cb81a6 2714 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2e3f92da
WY
2715 commands);
2716
2717 sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
a2f36eec
WY
2718 ctsn = ntohl(sdh->cum_tsn_ack);
2719
2720 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
bb33381d
DB
2721 pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn,
2722 asoc->ctsn_ack_point);
2723
a2f36eec
WY
2724 return SCTP_DISPOSITION_DISCARD;
2725 }
2e3f92da
WY
2726
2727 /* If Cumulative TSN Ack beyond the max tsn currently
2728 * send, terminating the association and respond to the
2729 * sender with an ABORT.
2730 */
a2f36eec 2731 if (!TSN_lt(ctsn, asoc->next_tsn))
24cb81a6 2732 return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands);
2e3f92da
WY
2733
2734 /* verify, by checking the Cumulative TSN Ack field of the
2735 * chunk, that all its outstanding DATA chunks have been
2736 * received by the SHUTDOWN sender.
2737 */
2738 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
2739 SCTP_BE32(sdh->cum_tsn_ack));
2740
2741 return SCTP_DISPOSITION_CONSUME;
2742}
2743
1da177e4
LT
2744/* RFC 2960 9.2
2745 * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk
2746 * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination
2747 * transport addresses (either in the IP addresses or in the INIT chunk)
2748 * that belong to this association, it should discard the INIT chunk and
2749 * retransmit the SHUTDOWN ACK chunk.
2750 */
24cb81a6
EB
2751sctp_disposition_t sctp_sf_do_9_2_reshutack(struct net *net,
2752 const struct sctp_endpoint *ep,
1da177e4
LT
2753 const struct sctp_association *asoc,
2754 const sctp_subtype_t type,
2755 void *arg,
2756 sctp_cmd_seq_t *commands)
2757{
2758 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
2759 struct sctp_chunk *reply;
2760
ece25dfa
VY
2761 /* Make sure that the chunk has a valid length */
2762 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
24cb81a6 2763 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
ece25dfa
VY
2764 commands);
2765
1da177e4
LT
2766 /* Since we are not going to really process this INIT, there
2767 * is no point in verifying chunk boundries. Just generate
2768 * the SHUTDOWN ACK.
2769 */
2770 reply = sctp_make_shutdown_ack(asoc, chunk);
2771 if (NULL == reply)
2772 goto nomem;
2773
2774 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
2775 * the T2-SHUTDOWN timer.
2776 */
2777 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
2778
2779 /* and restart the T2-shutdown timer. */
2780 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2781 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2782
2783 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2784
2785 return SCTP_DISPOSITION_CONSUME;
2786nomem:
2787 return SCTP_DISPOSITION_NOMEM;
2788}
2789
2790/*
2791 * sctp_sf_do_ecn_cwr
2792 *
2793 * Section: Appendix A: Explicit Congestion Notification
2794 *
2795 * CWR:
2796 *
2797 * RFC 2481 details a specific bit for a sender to send in the header of
2798 * its next outbound TCP segment to indicate to its peer that it has
2799 * reduced its congestion window. This is termed the CWR bit. For
2800 * SCTP the same indication is made by including the CWR chunk.
2801 * This chunk contains one data element, i.e. the TSN number that
2802 * was sent in the ECNE chunk. This element represents the lowest
2803 * TSN number in the datagram that was originally marked with the
2804 * CE bit.
2805 *
2806 * Verification Tag: 8.5 Verification Tag [Normal verification]
2807 * Inputs
2808 * (endpoint, asoc, chunk)
2809 *
2810 * Outputs
2811 * (asoc, reply_msg, msg_up, timers, counters)
2812 *
2813 * The return value is the disposition of the chunk.
2814 */
24cb81a6
EB
2815sctp_disposition_t sctp_sf_do_ecn_cwr(struct net *net,
2816 const struct sctp_endpoint *ep,
1da177e4
LT
2817 const struct sctp_association *asoc,
2818 const sctp_subtype_t type,
2819 void *arg,
2820 sctp_cmd_seq_t *commands)
2821{
2822 sctp_cwrhdr_t *cwr;
2823 struct sctp_chunk *chunk = arg;
34bcca28 2824 u32 lowest_tsn;
1da177e4
LT
2825
2826 if (!sctp_vtag_verify(chunk, asoc))
24cb81a6 2827 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
2828
2829 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
24cb81a6 2830 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4 2831 commands);
d808ad9a 2832
1da177e4
LT
2833 cwr = (sctp_cwrhdr_t *) chunk->skb->data;
2834 skb_pull(chunk->skb, sizeof(sctp_cwrhdr_t));
2835
34bcca28 2836 lowest_tsn = ntohl(cwr->lowest_tsn);
1da177e4
LT
2837
2838 /* Does this CWR ack the last sent congestion notification? */
34bcca28 2839 if (TSN_lte(asoc->last_ecne_tsn, lowest_tsn)) {
1da177e4
LT
2840 /* Stop sending ECNE. */
2841 sctp_add_cmd_sf(commands,
2842 SCTP_CMD_ECN_CWR,
34bcca28 2843 SCTP_U32(lowest_tsn));
1da177e4
LT
2844 }
2845 return SCTP_DISPOSITION_CONSUME;
2846}
2847
2848/*
2849 * sctp_sf_do_ecne
2850 *
2851 * Section: Appendix A: Explicit Congestion Notification
2852 *
2853 * ECN-Echo
2854 *
2855 * RFC 2481 details a specific bit for a receiver to send back in its
2856 * TCP acknowledgements to notify the sender of the Congestion
2857 * Experienced (CE) bit having arrived from the network. For SCTP this
2858 * same indication is made by including the ECNE chunk. This chunk
2859 * contains one data element, i.e. the lowest TSN associated with the IP
2860 * datagram marked with the CE bit.....
2861 *
2862 * Verification Tag: 8.5 Verification Tag [Normal verification]
2863 * Inputs
2864 * (endpoint, asoc, chunk)
2865 *
2866 * Outputs
2867 * (asoc, reply_msg, msg_up, timers, counters)
2868 *
2869 * The return value is the disposition of the chunk.
2870 */
24cb81a6
EB
2871sctp_disposition_t sctp_sf_do_ecne(struct net *net,
2872 const struct sctp_endpoint *ep,
1da177e4
LT
2873 const struct sctp_association *asoc,
2874 const sctp_subtype_t type,
2875 void *arg,
2876 sctp_cmd_seq_t *commands)
2877{
2878 sctp_ecnehdr_t *ecne;
2879 struct sctp_chunk *chunk = arg;
2880
2881 if (!sctp_vtag_verify(chunk, asoc))
24cb81a6 2882 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
2883
2884 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
24cb81a6 2885 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4
LT
2886 commands);
2887
2888 ecne = (sctp_ecnehdr_t *) chunk->skb->data;
2889 skb_pull(chunk->skb, sizeof(sctp_ecnehdr_t));
2890
2891 /* If this is a newer ECNE than the last CWR packet we sent out */
2892 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_ECNE,
2893 SCTP_U32(ntohl(ecne->lowest_tsn)));
2894
2895 return SCTP_DISPOSITION_CONSUME;
2896}
2897
2898/*
2899 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
2900 *
2901 * The SCTP endpoint MUST always acknowledge the reception of each valid
2902 * DATA chunk.
2903 *
2904 * The guidelines on delayed acknowledgement algorithm specified in
2905 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
2906 * acknowledgement SHOULD be generated for at least every second packet
2907 * (not every second DATA chunk) received, and SHOULD be generated within
2908 * 200 ms of the arrival of any unacknowledged DATA chunk. In some
2909 * situations it may be beneficial for an SCTP transmitter to be more
2910 * conservative than the algorithms detailed in this document allow.
2911 * However, an SCTP transmitter MUST NOT be more aggressive than the
2912 * following algorithms allow.
2913 *
2914 * A SCTP receiver MUST NOT generate more than one SACK for every
2915 * incoming packet, other than to update the offered window as the
2916 * receiving application consumes new data.
2917 *
2918 * Verification Tag: 8.5 Verification Tag [Normal verification]
2919 *
2920 * Inputs
2921 * (endpoint, asoc, chunk)
2922 *
2923 * Outputs
2924 * (asoc, reply_msg, msg_up, timers, counters)
2925 *
2926 * The return value is the disposition of the chunk.
2927 */
24cb81a6
EB
2928sctp_disposition_t sctp_sf_eat_data_6_2(struct net *net,
2929 const struct sctp_endpoint *ep,
1da177e4
LT
2930 const struct sctp_association *asoc,
2931 const sctp_subtype_t type,
2932 void *arg,
2933 sctp_cmd_seq_t *commands)
2934{
2935 struct sctp_chunk *chunk = arg;
6dc7694f 2936 sctp_arg_t force = SCTP_NOFORCE();
1da177e4
LT
2937 int error;
2938
2939 if (!sctp_vtag_verify(chunk, asoc)) {
2940 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
2941 SCTP_NULL());
24cb81a6 2942 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
d808ad9a 2943 }
1da177e4
LT
2944
2945 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
24cb81a6 2946 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4
LT
2947 commands);
2948
2949 error = sctp_eat_data(asoc, chunk, commands );
2950 switch (error) {
2951 case SCTP_IERROR_NO_ERROR:
2952 break;
2953 case SCTP_IERROR_HIGH_TSN:
2954 case SCTP_IERROR_BAD_STREAM:
24cb81a6 2955 SCTP_INC_STATS(net, SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
1da177e4
LT
2956 goto discard_noforce;
2957 case SCTP_IERROR_DUP_TSN:
2958 case SCTP_IERROR_IGNORE_TSN:
24cb81a6 2959 SCTP_INC_STATS(net, SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
1da177e4
LT
2960 goto discard_force;
2961 case SCTP_IERROR_NO_DATA:
2962 goto consume;
f1751c57 2963 case SCTP_IERROR_PROTO_VIOLATION:
24cb81a6 2964 return sctp_sf_abort_violation(net, ep, asoc, chunk, commands,
f1751c57 2965 (u8 *)chunk->subh.data_hdr, sizeof(sctp_datahdr_t));
1da177e4
LT
2966 default:
2967 BUG();
2968 }
2969
6dc7694f
WY
2970 if (chunk->chunk_hdr->flags & SCTP_DATA_SACK_IMM)
2971 force = SCTP_FORCE();
2972
1da177e4
LT
2973 if (asoc->autoclose) {
2974 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2975 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
2976 }
2977
2978 /* If this is the last chunk in a packet, we need to count it
2979 * toward sack generation. Note that we need to SACK every
2980 * OTHER packet containing data chunks, EVEN IF WE DISCARD
2981 * THEM. We elect to NOT generate SACK's if the chunk fails
2982 * the verification tag test.
2983 *
2984 * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2985 *
2986 * The SCTP endpoint MUST always acknowledge the reception of
2987 * each valid DATA chunk.
2988 *
2989 * The guidelines on delayed acknowledgement algorithm
2990 * specified in Section 4.2 of [RFC2581] SHOULD be followed.
2991 * Specifically, an acknowledgement SHOULD be generated for at
2992 * least every second packet (not every second DATA chunk)
2993 * received, and SHOULD be generated within 200 ms of the
2994 * arrival of any unacknowledged DATA chunk. In some
2995 * situations it may be beneficial for an SCTP transmitter to
2996 * be more conservative than the algorithms detailed in this
2997 * document allow. However, an SCTP transmitter MUST NOT be
2998 * more aggressive than the following algorithms allow.
2999 */
52ccb8e9 3000 if (chunk->end_of_packet)
6dc7694f 3001 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force);
1da177e4 3002
1da177e4
LT
3003 return SCTP_DISPOSITION_CONSUME;
3004
3005discard_force:
3006 /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
3007 *
3008 * When a packet arrives with duplicate DATA chunk(s) and with
3009 * no new DATA chunk(s), the endpoint MUST immediately send a
3010 * SACK with no delay. If a packet arrives with duplicate
3011 * DATA chunk(s) bundled with new DATA chunks, the endpoint
3012 * MAY immediately send a SACK. Normally receipt of duplicate
3013 * DATA chunks will occur when the original SACK chunk was lost
3014 * and the peer's RTO has expired. The duplicate TSN number(s)
3015 * SHOULD be reported in the SACK as duplicate.
3016 */
3017 /* In our case, we split the MAY SACK advice up whether or not
3018 * the last chunk is a duplicate.'
3019 */
3020 if (chunk->end_of_packet)
3021 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3022 return SCTP_DISPOSITION_DISCARD;
3023
3024discard_noforce:
52ccb8e9 3025 if (chunk->end_of_packet)
6dc7694f 3026 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force);
1da177e4 3027
1da177e4
LT
3028 return SCTP_DISPOSITION_DISCARD;
3029consume:
3030 return SCTP_DISPOSITION_CONSUME;
d808ad9a 3031
1da177e4
LT
3032}
3033
3034/*
3035 * sctp_sf_eat_data_fast_4_4
3036 *
3037 * Section: 4 (4)
3038 * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received
3039 * DATA chunks without delay.
3040 *
3041 * Verification Tag: 8.5 Verification Tag [Normal verification]
3042 * Inputs
3043 * (endpoint, asoc, chunk)
3044 *
3045 * Outputs
3046 * (asoc, reply_msg, msg_up, timers, counters)
3047 *
3048 * The return value is the disposition of the chunk.
3049 */
24cb81a6
EB
3050sctp_disposition_t sctp_sf_eat_data_fast_4_4(struct net *net,
3051 const struct sctp_endpoint *ep,
1da177e4
LT
3052 const struct sctp_association *asoc,
3053 const sctp_subtype_t type,
3054 void *arg,
3055 sctp_cmd_seq_t *commands)
3056{
3057 struct sctp_chunk *chunk = arg;
3058 int error;
3059
3060 if (!sctp_vtag_verify(chunk, asoc)) {
3061 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3062 SCTP_NULL());
24cb81a6 3063 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
3064 }
3065
3066 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
24cb81a6 3067 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4
LT
3068 commands);
3069
3070 error = sctp_eat_data(asoc, chunk, commands );
3071 switch (error) {
3072 case SCTP_IERROR_NO_ERROR:
3073 case SCTP_IERROR_HIGH_TSN:
3074 case SCTP_IERROR_DUP_TSN:
3075 case SCTP_IERROR_IGNORE_TSN:
3076 case SCTP_IERROR_BAD_STREAM:
3077 break;
3078 case SCTP_IERROR_NO_DATA:
3079 goto consume;
f1751c57 3080 case SCTP_IERROR_PROTO_VIOLATION:
24cb81a6 3081 return sctp_sf_abort_violation(net, ep, asoc, chunk, commands,
f1751c57 3082 (u8 *)chunk->subh.data_hdr, sizeof(sctp_datahdr_t));
1da177e4
LT
3083 default:
3084 BUG();
3085 }
3086
3087 /* Go a head and force a SACK, since we are shutting down. */
3088
3089 /* Implementor's Guide.
3090 *
3091 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3092 * respond to each received packet containing one or more DATA chunk(s)
3093 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3094 */
3095 if (chunk->end_of_packet) {
3096 /* We must delay the chunk creation since the cumulative
3097 * TSN has not been updated yet.
3098 */
3099 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
3100 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3101 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3102 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3103 }
3104
3105consume:
3106 return SCTP_DISPOSITION_CONSUME;
3107}
3108
3109/*
3110 * Section: 6.2 Processing a Received SACK
3111 * D) Any time a SACK arrives, the endpoint performs the following:
3112 *
3113 * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point,
3114 * then drop the SACK. Since Cumulative TSN Ack is monotonically
3115 * increasing, a SACK whose Cumulative TSN Ack is less than the
3116 * Cumulative TSN Ack Point indicates an out-of-order SACK.
3117 *
3118 * ii) Set rwnd equal to the newly received a_rwnd minus the number
3119 * of bytes still outstanding after processing the Cumulative TSN Ack
3120 * and the Gap Ack Blocks.
3121 *
3122 * iii) If the SACK is missing a TSN that was previously
3123 * acknowledged via a Gap Ack Block (e.g., the data receiver
3124 * reneged on the data), then mark the corresponding DATA chunk
3125 * as available for retransmit: Mark it as missing for fast
3126 * retransmit as described in Section 7.2.4 and if no retransmit
3127 * timer is running for the destination address to which the DATA
3128 * chunk was originally transmitted, then T3-rtx is started for
3129 * that destination address.
3130 *
3131 * Verification Tag: 8.5 Verification Tag [Normal verification]
3132 *
3133 * Inputs
3134 * (endpoint, asoc, chunk)
3135 *
3136 * Outputs
3137 * (asoc, reply_msg, msg_up, timers, counters)
3138 *
3139 * The return value is the disposition of the chunk.
3140 */
24cb81a6
EB
3141sctp_disposition_t sctp_sf_eat_sack_6_2(struct net *net,
3142 const struct sctp_endpoint *ep,
1da177e4
LT
3143 const struct sctp_association *asoc,
3144 const sctp_subtype_t type,
3145 void *arg,
3146 sctp_cmd_seq_t *commands)
3147{
3148 struct sctp_chunk *chunk = arg;
3149 sctp_sackhdr_t *sackh;
3150 __u32 ctsn;
3151
3152 if (!sctp_vtag_verify(chunk, asoc))
24cb81a6 3153 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
3154
3155 /* Make sure that the SACK chunk has a valid length. */
3156 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_sack_chunk_t)))
24cb81a6 3157 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4
LT
3158 commands);
3159
3160 /* Pull the SACK chunk from the data buffer */
3161 sackh = sctp_sm_pull_sack(chunk);
3162 /* Was this a bogus SACK? */
3163 if (!sackh)
24cb81a6 3164 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
3165 chunk->subh.sack_hdr = sackh;
3166 ctsn = ntohl(sackh->cum_tsn_ack);
3167
3168 /* i) If Cumulative TSN Ack is less than the Cumulative TSN
3169 * Ack Point, then drop the SACK. Since Cumulative TSN
3170 * Ack is monotonically increasing, a SACK whose
3171 * Cumulative TSN Ack is less than the Cumulative TSN Ack
3172 * Point indicates an out-of-order SACK.
3173 */
3174 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
bb33381d
DB
3175 pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn,
3176 asoc->ctsn_ack_point);
3177
1da177e4
LT
3178 return SCTP_DISPOSITION_DISCARD;
3179 }
3180
aecedeab
WY
3181 /* If Cumulative TSN Ack beyond the max tsn currently
3182 * send, terminating the association and respond to the
3183 * sender with an ABORT.
3184 */
3185 if (!TSN_lt(ctsn, asoc->next_tsn))
24cb81a6 3186 return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands);
aecedeab 3187
1da177e4 3188 /* Return this SACK for further processing. */
edfee033 3189 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_CHUNK(chunk));
1da177e4
LT
3190
3191 /* Note: We do the rest of the work on the PROCESS_SACK
3192 * sideeffect.
3193 */
3194 return SCTP_DISPOSITION_CONSUME;
3195}
3196
3197/*
3198 * Generate an ABORT in response to a packet.
3199 *
047a2428 3200 * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41
1da177e4 3201 *
047a2428
JF
3202 * 8) The receiver should respond to the sender of the OOTB packet with
3203 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3204 * MUST fill in the Verification Tag field of the outbound packet
3205 * with the value found in the Verification Tag field of the OOTB
3206 * packet and set the T-bit in the Chunk Flags to indicate that the
3207 * Verification Tag is reflected. After sending this ABORT, the
3208 * receiver of the OOTB packet shall discard the OOTB packet and take
3209 * no further action.
1da177e4
LT
3210 *
3211 * Verification Tag:
3212 *
3213 * The return value is the disposition of the chunk.
3214*/
24cb81a6
EB
3215static sctp_disposition_t sctp_sf_tabort_8_4_8(struct net *net,
3216 const struct sctp_endpoint *ep,
1da177e4
LT
3217 const struct sctp_association *asoc,
3218 const sctp_subtype_t type,
3219 void *arg,
3220 sctp_cmd_seq_t *commands)
3221{
3222 struct sctp_packet *packet = NULL;
3223 struct sctp_chunk *chunk = arg;
3224 struct sctp_chunk *abort;
3225
2ce95503 3226 packet = sctp_ootb_pkt_new(net, asoc, chunk);
1da177e4
LT
3227
3228 if (packet) {
3229 /* Make an ABORT. The T bit will be set if the asoc
3230 * is NULL.
3231 */
d808ad9a 3232 abort = sctp_make_abort(asoc, chunk, 0);
1da177e4
LT
3233 if (!abort) {
3234 sctp_ootb_pkt_free(packet);
3235 return SCTP_DISPOSITION_NOMEM;
3236 }
3237
047a2428
JF
3238 /* Reflect vtag if T-Bit is set */
3239 if (sctp_test_T_bit(abort))
3240 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3241
1da177e4
LT
3242 /* Set the skb to the belonging sock for accounting. */
3243 abort->skb->sk = ep->base.sk;
3244
3245 sctp_packet_append_chunk(packet, abort);
3246
3247 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3248 SCTP_PACKET(packet));
3249
b01a2407 3250 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
1da177e4 3251
24cb81a6 3252 sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
3253 return SCTP_DISPOSITION_CONSUME;
3254 }
3255
3256 return SCTP_DISPOSITION_NOMEM;
3257}
3258
3259/*
3260 * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR
3261 * event as ULP notification for each cause included in the chunk.
3262 *
3263 * API 5.3.1.3 - SCTP_REMOTE_ERROR
3264 *
3265 * The return value is the disposition of the chunk.
3266*/
24cb81a6
EB
3267sctp_disposition_t sctp_sf_operr_notify(struct net *net,
3268 const struct sctp_endpoint *ep,
1da177e4
LT
3269 const struct sctp_association *asoc,
3270 const sctp_subtype_t type,
3271 void *arg,
3272 sctp_cmd_seq_t *commands)
3273{
3274 struct sctp_chunk *chunk = arg;
8a00be1c 3275 sctp_errhdr_t *err;
1da177e4
LT
3276
3277 if (!sctp_vtag_verify(chunk, asoc))
24cb81a6 3278 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
3279
3280 /* Make sure that the ERROR chunk has a valid length. */
3281 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
24cb81a6 3282 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4 3283 commands);
8a00be1c
SW
3284 sctp_walk_errors(err, chunk->chunk_hdr);
3285 if ((void *)err != (void *)chunk->chunk_end)
24cb81a6 3286 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
8a00be1c 3287 (void *)err, commands);
1da177e4 3288
3df26787
WY
3289 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_OPERR,
3290 SCTP_CHUNK(chunk));
1da177e4 3291
1da177e4 3292 return SCTP_DISPOSITION_CONSUME;
1da177e4
LT
3293}
3294
3295/*
3296 * Process an inbound SHUTDOWN ACK.
3297 *
3298 * From Section 9.2:
3299 * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3300 * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its
3301 * peer, and remove all record of the association.
3302 *
3303 * The return value is the disposition.
3304 */
24cb81a6
EB
3305sctp_disposition_t sctp_sf_do_9_2_final(struct net *net,
3306 const struct sctp_endpoint *ep,
1da177e4
LT
3307 const struct sctp_association *asoc,
3308 const sctp_subtype_t type,
3309 void *arg,
3310 sctp_cmd_seq_t *commands)
3311{
3312 struct sctp_chunk *chunk = arg;
3313 struct sctp_chunk *reply;
3314 struct sctp_ulpevent *ev;
3315
3316 if (!sctp_vtag_verify(chunk, asoc))
24cb81a6 3317 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
3318
3319 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3320 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
24cb81a6 3321 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4 3322 commands);
1da177e4
LT
3323 /* 10.2 H) SHUTDOWN COMPLETE notification
3324 *
3325 * When SCTP completes the shutdown procedures (section 9.2) this
3326 * notification is passed to the upper layer.
3327 */
3328 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
a5a35e76 3329 0, 0, 0, NULL, GFP_ATOMIC);
1da177e4
LT
3330 if (!ev)
3331 goto nomem;
3332
df7deeb5
VY
3333 /* ...send a SHUTDOWN COMPLETE chunk to its peer, */
3334 reply = sctp_make_shutdown_complete(asoc, chunk);
3335 if (!reply)
3336 goto nomem_chunk;
3337
3338 /* Do all the commands now (after allocation), so that we
3339 * have consistent state if memory allocation failes
3340 */
1da177e4
LT
3341 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
3342
3343 /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3344 * stop the T2-shutdown timer,
3345 */
3346 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3347 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3348
3349 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3350 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
3351
1da177e4
LT
3352 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3353 SCTP_STATE(SCTP_STATE_CLOSED));
b01a2407
EB
3354 SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS);
3355 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
1da177e4
LT
3356 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
3357
3358 /* ...and remove all record of the association. */
3359 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
3360 return SCTP_DISPOSITION_DELETE_TCB;
3361
df7deeb5
VY
3362nomem_chunk:
3363 sctp_ulpevent_free(ev);
1da177e4
LT
3364nomem:
3365 return SCTP_DISPOSITION_NOMEM;
3366}
3367
3368/*
047a2428
JF
3369 * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41.
3370 *
1da177e4
LT
3371 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3372 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3373 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3374 * packet must fill in the Verification Tag field of the outbound
3375 * packet with the Verification Tag received in the SHUTDOWN ACK and
047a2428
JF
3376 * set the T-bit in the Chunk Flags to indicate that the Verification
3377 * Tag is reflected.
1da177e4
LT
3378 *
3379 * 8) The receiver should respond to the sender of the OOTB packet with
3380 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3381 * MUST fill in the Verification Tag field of the outbound packet
3382 * with the value found in the Verification Tag field of the OOTB
047a2428
JF
3383 * packet and set the T-bit in the Chunk Flags to indicate that the
3384 * Verification Tag is reflected. After sending this ABORT, the
3385 * receiver of the OOTB packet shall discard the OOTB packet and take
3386 * no further action.
1da177e4 3387 */
24cb81a6
EB
3388sctp_disposition_t sctp_sf_ootb(struct net *net,
3389 const struct sctp_endpoint *ep,
1da177e4
LT
3390 const struct sctp_association *asoc,
3391 const sctp_subtype_t type,
3392 void *arg,
3393 sctp_cmd_seq_t *commands)
3394{
3395 struct sctp_chunk *chunk = arg;
3396 struct sk_buff *skb = chunk->skb;
3397 sctp_chunkhdr_t *ch;
85c5ed4e 3398 sctp_errhdr_t *err;
1da177e4
LT
3399 __u8 *ch_end;
3400 int ootb_shut_ack = 0;
85c5ed4e 3401 int ootb_cookie_ack = 0;
1da177e4 3402
b01a2407 3403 SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
1da177e4
LT
3404
3405 ch = (sctp_chunkhdr_t *) chunk->chunk_hdr;
3406 do {
ece25dfa 3407 /* Report violation if the chunk is less then minimal */
1da177e4 3408 if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t))
24cb81a6 3409 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
ece25dfa 3410 commands);
1da177e4 3411
ece25dfa
VY
3412 /* Now that we know we at least have a chunk header,
3413 * do things that are type appropriate.
3414 */
1da177e4
LT
3415 if (SCTP_CID_SHUTDOWN_ACK == ch->type)
3416 ootb_shut_ack = 1;
3417
3418 /* RFC 2960, Section 3.3.7
3419 * Moreover, under any circumstances, an endpoint that
3420 * receives an ABORT MUST NOT respond to that ABORT by
3421 * sending an ABORT of its own.
3422 */
3423 if (SCTP_CID_ABORT == ch->type)
24cb81a6 3424 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
d808ad9a 3425
85c5ed4e
SW
3426 /* RFC 8.4, 7) If the packet contains a "Stale cookie" ERROR
3427 * or a COOKIE ACK the SCTP Packet should be silently
3428 * discarded.
3429 */
3430
3431 if (SCTP_CID_COOKIE_ACK == ch->type)
3432 ootb_cookie_ack = 1;
3433
3434 if (SCTP_CID_ERROR == ch->type) {
3435 sctp_walk_errors(err, ch) {
3436 if (SCTP_ERROR_STALE_COOKIE == err->cause) {
3437 ootb_cookie_ack = 1;
3438 break;
3439 }
3440 }
3441 }
3442
ece25dfa
VY
3443 /* Report violation if chunk len overflows */
3444 ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
3445 if (ch_end > skb_tail_pointer(skb))
24cb81a6 3446 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
ece25dfa
VY
3447 commands);
3448
1da177e4 3449 ch = (sctp_chunkhdr_t *) ch_end;
27a884dc 3450 } while (ch_end < skb_tail_pointer(skb));
1da177e4
LT
3451
3452 if (ootb_shut_ack)
24cb81a6 3453 return sctp_sf_shut_8_4_5(net, ep, asoc, type, arg, commands);
85c5ed4e 3454 else if (ootb_cookie_ack)
24cb81a6 3455 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4 3456 else
24cb81a6 3457 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
1da177e4
LT
3458}
3459
3460/*
3461 * Handle an "Out of the blue" SHUTDOWN ACK.
3462 *
047a2428
JF
3463 * Section: 8.4 5, sctpimpguide 2.41.
3464 *
1da177e4 3465 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
047a2428
JF
3466 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3467 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3468 * packet must fill in the Verification Tag field of the outbound
3469 * packet with the Verification Tag received in the SHUTDOWN ACK and
3470 * set the T-bit in the Chunk Flags to indicate that the Verification
3471 * Tag is reflected.
1da177e4
LT
3472 *
3473 * Inputs
3474 * (endpoint, asoc, type, arg, commands)
3475 *
3476 * Outputs
3477 * (sctp_disposition_t)
3478 *
3479 * The return value is the disposition of the chunk.
3480 */
24cb81a6
EB
3481static sctp_disposition_t sctp_sf_shut_8_4_5(struct net *net,
3482 const struct sctp_endpoint *ep,
1da177e4
LT
3483 const struct sctp_association *asoc,
3484 const sctp_subtype_t type,
3485 void *arg,
3486 sctp_cmd_seq_t *commands)
3487{
3488 struct sctp_packet *packet = NULL;
3489 struct sctp_chunk *chunk = arg;
3490 struct sctp_chunk *shut;
3491
2ce95503 3492 packet = sctp_ootb_pkt_new(net, asoc, chunk);
1da177e4
LT
3493
3494 if (packet) {
3495 /* Make an SHUTDOWN_COMPLETE.
d808ad9a
YH
3496 * The T bit will be set if the asoc is NULL.
3497 */
1da177e4
LT
3498 shut = sctp_make_shutdown_complete(asoc, chunk);
3499 if (!shut) {
3500 sctp_ootb_pkt_free(packet);
3501 return SCTP_DISPOSITION_NOMEM;
3502 }
3503
047a2428
JF
3504 /* Reflect vtag if T-Bit is set */
3505 if (sctp_test_T_bit(shut))
3506 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3507
1da177e4
LT
3508 /* Set the skb to the belonging sock for accounting. */
3509 shut->skb->sk = ep->base.sk;
3510
3511 sctp_packet_append_chunk(packet, shut);
3512
3513 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3514 SCTP_PACKET(packet));
3515
b01a2407 3516 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
1da177e4
LT
3517
3518 /* If the chunk length is invalid, we don't want to process
3519 * the reset of the packet.
3520 */
3521 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
24cb81a6 3522 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4 3523
d3f25968
VY
3524 /* We need to discard the rest of the packet to prevent
3525 * potential bomming attacks from additional bundled chunks.
3526 * This is documented in SCTP Threats ID.
3527 */
24cb81a6 3528 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
3529 }
3530
3531 return SCTP_DISPOSITION_NOMEM;
3532}
3533
3534/*
3535 * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state.
3536 *
3537 * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK
3538 * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the
3539 * procedures in section 8.4 SHOULD be followed, in other words it
3540 * should be treated as an Out Of The Blue packet.
3541 * [This means that we do NOT check the Verification Tag on these
3542 * chunks. --piggy ]
3543 *
3544 */
24cb81a6
EB
3545sctp_disposition_t sctp_sf_do_8_5_1_E_sa(struct net *net,
3546 const struct sctp_endpoint *ep,
1da177e4
LT
3547 const struct sctp_association *asoc,
3548 const sctp_subtype_t type,
3549 void *arg,
3550 sctp_cmd_seq_t *commands)
3551{
ece25dfa
VY
3552 struct sctp_chunk *chunk = arg;
3553
3554 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3555 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
24cb81a6 3556 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
ece25dfa
VY
3557 commands);
3558
1da177e4
LT
3559 /* Although we do have an association in this case, it corresponds
3560 * to a restarted association. So the packet is treated as an OOTB
3561 * packet and the state function that handles OOTB SHUTDOWN_ACK is
3562 * called with a NULL association.
3563 */
24cb81a6 3564 SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
8190f89d 3565
24cb81a6 3566 return sctp_sf_shut_8_4_5(net, ep, NULL, type, arg, commands);
1da177e4
LT
3567}
3568
3569/* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */
24cb81a6
EB
3570sctp_disposition_t sctp_sf_do_asconf(struct net *net,
3571 const struct sctp_endpoint *ep,
1da177e4
LT
3572 const struct sctp_association *asoc,
3573 const sctp_subtype_t type, void *arg,
3574 sctp_cmd_seq_t *commands)
3575{
3576 struct sctp_chunk *chunk = arg;
3577 struct sctp_chunk *asconf_ack = NULL;
6f4c618d 3578 struct sctp_paramhdr *err_param = NULL;
1da177e4 3579 sctp_addiphdr_t *hdr;
6f4c618d 3580 union sctp_addr_param *addr_param;
1da177e4 3581 __u32 serial;
6f4c618d 3582 int length;
1da177e4
LT
3583
3584 if (!sctp_vtag_verify(chunk, asoc)) {
3585 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3586 SCTP_NULL());
24cb81a6 3587 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
3588 }
3589
6afd2e83
VY
3590 /* ADD-IP: Section 4.1.1
3591 * This chunk MUST be sent in an authenticated way by using
3592 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3593 * is received unauthenticated it MUST be silently discarded as
3594 * described in [I-D.ietf-tsvwg-sctp-auth].
3595 */
e1fc3b14 3596 if (!net->sctp.addip_noauth && !chunk->auth)
24cb81a6 3597 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
6afd2e83 3598
1da177e4
LT
3599 /* Make sure that the ASCONF ADDIP chunk has a valid length. */
3600 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_addip_chunk_t)))
24cb81a6 3601 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4
LT
3602 commands);
3603
3604 hdr = (sctp_addiphdr_t *)chunk->skb->data;
3605 serial = ntohl(hdr->serial);
3606
6f4c618d
WY
3607 addr_param = (union sctp_addr_param *)hdr->params;
3608 length = ntohs(addr_param->p.length);
3609 if (length < sizeof(sctp_paramhdr_t))
24cb81a6 3610 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
6f4c618d
WY
3611 (void *)addr_param, commands);
3612
3613 /* Verify the ASCONF chunk before processing it. */
3614 if (!sctp_verify_asconf(asoc,
a08de64d
VY
3615 (sctp_paramhdr_t *)((void *)addr_param + length),
3616 (void *)chunk->chunk_end,
3617 &err_param))
24cb81a6 3618 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
ba016670 3619 (void *)err_param, commands);
6f4c618d 3620
a08de64d 3621 /* ADDIP 5.2 E1) Compare the value of the serial number to the value
1da177e4 3622 * the endpoint stored in a new association variable
d808ad9a 3623 * 'Peer-Serial-Number'.
1da177e4
LT
3624 */
3625 if (serial == asoc->peer.addip_serial + 1) {
a08de64d
VY
3626 /* If this is the first instance of ASCONF in the packet,
3627 * we can clean our old ASCONF-ACKs.
3628 */
3629 if (!chunk->has_asconf)
3630 sctp_assoc_clean_asconf_ack_cache(asoc);
3631
3632 /* ADDIP 5.2 E4) When the Sequence Number matches the next one
3633 * expected, process the ASCONF as described below and after
3634 * processing the ASCONF Chunk, append an ASCONF-ACK Chunk to
3635 * the response packet and cache a copy of it (in the event it
3636 * later needs to be retransmitted).
3637 *
3638 * Essentially, do V1-V5.
1da177e4
LT
3639 */
3640 asconf_ack = sctp_process_asconf((struct sctp_association *)
3641 asoc, chunk);
3642 if (!asconf_ack)
3643 return SCTP_DISPOSITION_NOMEM;
a08de64d
VY
3644 } else if (serial < asoc->peer.addip_serial + 1) {
3645 /* ADDIP 5.2 E2)
3646 * If the value found in the Sequence Number is less than the
3647 * ('Peer- Sequence-Number' + 1), simply skip to the next
3648 * ASCONF, and include in the outbound response packet
3649 * any previously cached ASCONF-ACK response that was
3650 * sent and saved that matches the Sequence Number of the
3651 * ASCONF. Note: It is possible that no cached ASCONF-ACK
3652 * Chunk exists. This will occur when an older ASCONF
3653 * arrives out of order. In such a case, the receiver
3654 * should skip the ASCONF Chunk and not include ASCONF-ACK
3655 * Chunk for that chunk.
1da177e4 3656 */
a08de64d
VY
3657 asconf_ack = sctp_assoc_lookup_asconf_ack(asoc, hdr->serial);
3658 if (!asconf_ack)
1da177e4 3659 return SCTP_DISPOSITION_DISCARD;
31b02e15
VY
3660
3661 /* Reset the transport so that we select the correct one
3662 * this time around. This is to make sure that we don't
3663 * accidentally use a stale transport that's been removed.
3664 */
3665 asconf_ack->transport = NULL;
1da177e4 3666 } else {
a08de64d 3667 /* ADDIP 5.2 E5) Otherwise, the ASCONF Chunk is discarded since
1da177e4 3668 * it must be either a stale packet or from an attacker.
d808ad9a 3669 */
1da177e4
LT
3670 return SCTP_DISPOSITION_DISCARD;
3671 }
3672
a08de64d
VY
3673 /* ADDIP 5.2 E6) The destination address of the SCTP packet
3674 * containing the ASCONF-ACK Chunks MUST be the source address of
3675 * the SCTP packet that held the ASCONF Chunks.
3676 *
3677 * To do this properly, we'll set the destination address of the chunk
3678 * and at the transmit time, will try look up the transport to use.
3679 * Since ASCONFs may be bundled, the correct transport may not be
94e2bd68 3680 * created until we process the entire packet, thus this workaround.
1da177e4 3681 */
a08de64d 3682 asconf_ack->dest = chunk->source;
1da177e4 3683 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(asconf_ack));
6af29ccc
MH
3684 if (asoc->new_transport) {
3685 sctp_sf_heartbeat(ep, asoc, type, asoc->new_transport,
3686 commands);
3687 ((struct sctp_association *)asoc)->new_transport = NULL;
3688 }
d808ad9a 3689
1da177e4
LT
3690 return SCTP_DISPOSITION_CONSUME;
3691}
3692
3693/*
3694 * ADDIP Section 4.3 General rules for address manipulation
3695 * When building TLV parameters for the ASCONF Chunk that will add or
3696 * delete IP addresses the D0 to D13 rules should be applied:
3697 */
24cb81a6
EB
3698sctp_disposition_t sctp_sf_do_asconf_ack(struct net *net,
3699 const struct sctp_endpoint *ep,
1da177e4 3700 const struct sctp_association *asoc,
d808ad9a 3701 const sctp_subtype_t type, void *arg,
1da177e4
LT
3702 sctp_cmd_seq_t *commands)
3703{
3704 struct sctp_chunk *asconf_ack = arg;
3705 struct sctp_chunk *last_asconf = asoc->addip_last_asconf;
3706 struct sctp_chunk *abort;
6f4c618d 3707 struct sctp_paramhdr *err_param = NULL;
1da177e4
LT
3708 sctp_addiphdr_t *addip_hdr;
3709 __u32 sent_serial, rcvd_serial;
3710
3711 if (!sctp_vtag_verify(asconf_ack, asoc)) {
3712 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3713 SCTP_NULL());
24cb81a6 3714 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
3715 }
3716
6afd2e83
VY
3717 /* ADD-IP, Section 4.1.2:
3718 * This chunk MUST be sent in an authenticated way by using
3719 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3720 * is received unauthenticated it MUST be silently discarded as
3721 * described in [I-D.ietf-tsvwg-sctp-auth].
3722 */
e1fc3b14 3723 if (!net->sctp.addip_noauth && !asconf_ack->auth)
24cb81a6 3724 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
6afd2e83 3725
1da177e4
LT
3726 /* Make sure that the ADDIP chunk has a valid length. */
3727 if (!sctp_chunk_length_valid(asconf_ack, sizeof(sctp_addip_chunk_t)))
24cb81a6 3728 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4
LT
3729 commands);
3730
3731 addip_hdr = (sctp_addiphdr_t *)asconf_ack->skb->data;
3732 rcvd_serial = ntohl(addip_hdr->serial);
3733
6f4c618d
WY
3734 /* Verify the ASCONF-ACK chunk before processing it. */
3735 if (!sctp_verify_asconf(asoc,
3736 (sctp_paramhdr_t *)addip_hdr->params,
3737 (void *)asconf_ack->chunk_end,
3738 &err_param))
24cb81a6 3739 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
ba016670 3740 (void *)err_param, commands);
6f4c618d 3741
1da177e4
LT
3742 if (last_asconf) {
3743 addip_hdr = (sctp_addiphdr_t *)last_asconf->subh.addip_hdr;
3744 sent_serial = ntohl(addip_hdr->serial);
3745 } else {
3746 sent_serial = asoc->addip_serial - 1;
3747 }
3748
3749 /* D0) If an endpoint receives an ASCONF-ACK that is greater than or
3750 * equal to the next serial number to be used but no ASCONF chunk is
3751 * outstanding the endpoint MUST ABORT the association. Note that a
3752 * sequence number is greater than if it is no more than 2^^31-1
3753 * larger than the current sequence number (using serial arithmetic).
3754 */
3755 if (ADDIP_SERIAL_gte(rcvd_serial, sent_serial + 1) &&
3756 !(asoc->addip_last_asconf)) {
3757 abort = sctp_make_abort(asoc, asconf_ack,
3758 sizeof(sctp_errhdr_t));
3759 if (abort) {
00f1c2df 3760 sctp_init_cause(abort, SCTP_ERROR_ASCONF_ACK, 0);
1da177e4
LT
3761 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3762 SCTP_CHUNK(abort));
3763 }
3764 /* We are going to ABORT, so we might as well stop
3765 * processing the rest of the chunks in the packet.
3766 */
3767 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3768 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3769 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
8de8c873 3770 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
d808ad9a 3771 SCTP_ERROR(ECONNABORTED));
1da177e4 3772 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5be291fe 3773 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
b01a2407
EB
3774 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
3775 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
1da177e4
LT
3776 return SCTP_DISPOSITION_ABORT;
3777 }
3778
3779 if ((rcvd_serial == sent_serial) && asoc->addip_last_asconf) {
3780 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3781 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3782
3783 if (!sctp_process_asconf_ack((struct sctp_association *)asoc,
c0786693
VY
3784 asconf_ack)) {
3785 /* Successfully processed ASCONF_ACK. We can
3786 * release the next asconf if we have one.
3787 */
3788 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_NEXT_ASCONF,
3789 SCTP_NULL());
1da177e4 3790 return SCTP_DISPOSITION_CONSUME;
c0786693 3791 }
1da177e4
LT
3792
3793 abort = sctp_make_abort(asoc, asconf_ack,
3794 sizeof(sctp_errhdr_t));
3795 if (abort) {
00f1c2df 3796 sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0);
1da177e4
LT
3797 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3798 SCTP_CHUNK(abort));
3799 }
3800 /* We are going to ABORT, so we might as well stop
3801 * processing the rest of the chunks in the packet.
3802 */
3803 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
8de8c873 3804 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
d808ad9a 3805 SCTP_ERROR(ECONNABORTED));
1da177e4 3806 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5be291fe 3807 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
b01a2407
EB
3808 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
3809 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
1da177e4
LT
3810 return SCTP_DISPOSITION_ABORT;
3811 }
3812
3813 return SCTP_DISPOSITION_DISCARD;
3814}
3815
3816/*
3817 * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP
3818 *
3819 * When a FORWARD TSN chunk arrives, the data receiver MUST first update
3820 * its cumulative TSN point to the value carried in the FORWARD TSN
3821 * chunk, and then MUST further advance its cumulative TSN point locally
3822 * if possible.
3823 * After the above processing, the data receiver MUST stop reporting any
3824 * missing TSNs earlier than or equal to the new cumulative TSN point.
3825 *
3826 * Verification Tag: 8.5 Verification Tag [Normal verification]
3827 *
3828 * The return value is the disposition of the chunk.
3829 */
24cb81a6
EB
3830sctp_disposition_t sctp_sf_eat_fwd_tsn(struct net *net,
3831 const struct sctp_endpoint *ep,
1da177e4
LT
3832 const struct sctp_association *asoc,
3833 const sctp_subtype_t type,
3834 void *arg,
3835 sctp_cmd_seq_t *commands)
3836{
3837 struct sctp_chunk *chunk = arg;
3838 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
9fcb95a1 3839 struct sctp_fwdtsn_skip *skip;
1da177e4
LT
3840 __u16 len;
3841 __u32 tsn;
3842
3843 if (!sctp_vtag_verify(chunk, asoc)) {
3844 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3845 SCTP_NULL());
24cb81a6 3846 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
3847 }
3848
3849 /* Make sure that the FORWARD_TSN chunk has valid length. */
3850 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
24cb81a6 3851 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4
LT
3852 commands);
3853
3854 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3855 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3856 len = ntohs(chunk->chunk_hdr->length);
3857 len -= sizeof(struct sctp_chunkhdr);
3858 skb_pull(chunk->skb, len);
3859
3860 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
bb33381d 3861 pr_debug("%s: TSN 0x%x\n", __func__, tsn);
1da177e4
LT
3862
3863 /* The TSN is too high--silently discard the chunk and count on it
3864 * getting retransmitted later.
3865 */
3866 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3867 goto discard_noforce;
3868
9fcb95a1
WY
3869 /* Silently discard the chunk if stream-id is not valid */
3870 sctp_walk_fwdtsn(skip, chunk) {
3871 if (ntohs(skip->stream) >= asoc->c.sinit_max_instreams)
3872 goto discard_noforce;
3873 }
3874
1da177e4
LT
3875 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3876 if (len > sizeof(struct sctp_fwdtsn_hdr))
d808ad9a 3877 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
1da177e4 3878 SCTP_CHUNK(chunk));
d808ad9a 3879
1da177e4
LT
3880 /* Count this as receiving DATA. */
3881 if (asoc->autoclose) {
3882 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3883 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
3884 }
d808ad9a 3885
1da177e4 3886 /* FIXME: For now send a SACK, but DATA processing may
d808ad9a 3887 * send another.
1da177e4
LT
3888 */
3889 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
1da177e4
LT
3890
3891 return SCTP_DISPOSITION_CONSUME;
3892
3893discard_noforce:
3894 return SCTP_DISPOSITION_DISCARD;
3895}
3896
3897sctp_disposition_t sctp_sf_eat_fwd_tsn_fast(
24cb81a6 3898 struct net *net,
1da177e4
LT
3899 const struct sctp_endpoint *ep,
3900 const struct sctp_association *asoc,
3901 const sctp_subtype_t type,
3902 void *arg,
3903 sctp_cmd_seq_t *commands)
3904{
3905 struct sctp_chunk *chunk = arg;
3906 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
9fcb95a1 3907 struct sctp_fwdtsn_skip *skip;
1da177e4
LT
3908 __u16 len;
3909 __u32 tsn;
3910
3911 if (!sctp_vtag_verify(chunk, asoc)) {
3912 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3913 SCTP_NULL());
24cb81a6 3914 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
3915 }
3916
3917 /* Make sure that the FORWARD_TSN chunk has a valid length. */
3918 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
24cb81a6 3919 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4
LT
3920 commands);
3921
3922 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3923 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3924 len = ntohs(chunk->chunk_hdr->length);
3925 len -= sizeof(struct sctp_chunkhdr);
3926 skb_pull(chunk->skb, len);
3927
3928 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
bb33381d 3929 pr_debug("%s: TSN 0x%x\n", __func__, tsn);
1da177e4
LT
3930
3931 /* The TSN is too high--silently discard the chunk and count on it
3932 * getting retransmitted later.
3933 */
3934 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3935 goto gen_shutdown;
3936
9fcb95a1
WY
3937 /* Silently discard the chunk if stream-id is not valid */
3938 sctp_walk_fwdtsn(skip, chunk) {
3939 if (ntohs(skip->stream) >= asoc->c.sinit_max_instreams)
3940 goto gen_shutdown;
3941 }
3942
1da177e4
LT
3943 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3944 if (len > sizeof(struct sctp_fwdtsn_hdr))
d808ad9a 3945 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
1da177e4 3946 SCTP_CHUNK(chunk));
d808ad9a 3947
1da177e4
LT
3948 /* Go a head and force a SACK, since we are shutting down. */
3949gen_shutdown:
3950 /* Implementor's Guide.
3951 *
3952 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3953 * respond to each received packet containing one or more DATA chunk(s)
3954 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3955 */
3956 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
3957 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3958 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3959 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3960
d808ad9a 3961 return SCTP_DISPOSITION_CONSUME;
1da177e4
LT
3962}
3963
bbd0d598 3964/*
25985edc 3965 * SCTP-AUTH Section 6.3 Receiving authenticated chukns
bbd0d598
VY
3966 *
3967 * The receiver MUST use the HMAC algorithm indicated in the HMAC
3968 * Identifier field. If this algorithm was not specified by the
3969 * receiver in the HMAC-ALGO parameter in the INIT or INIT-ACK chunk
3970 * during association setup, the AUTH chunk and all chunks after it MUST
3971 * be discarded and an ERROR chunk SHOULD be sent with the error cause
3972 * defined in Section 4.1.
3973 *
3974 * If an endpoint with no shared key receives a Shared Key Identifier
3975 * other than 0, it MUST silently discard all authenticated chunks. If
3976 * the endpoint has at least one endpoint pair shared key for the peer,
3977 * it MUST use the key specified by the Shared Key Identifier if a
3978 * key has been configured for that Shared Key Identifier. If no
3979 * endpoint pair shared key has been configured for that Shared Key
3980 * Identifier, all authenticated chunks MUST be silently discarded.
3981 *
3982 * Verification Tag: 8.5 Verification Tag [Normal verification]
3983 *
3984 * The return value is the disposition of the chunk.
3985 */
24cb81a6
EB
3986static sctp_ierror_t sctp_sf_authenticate(struct net *net,
3987 const struct sctp_endpoint *ep,
bbd0d598
VY
3988 const struct sctp_association *asoc,
3989 const sctp_subtype_t type,
3990 struct sctp_chunk *chunk)
3991{
3992 struct sctp_authhdr *auth_hdr;
3993 struct sctp_hmac *hmac;
3994 unsigned int sig_len;
3995 __u16 key_id;
3996 __u8 *save_digest;
3997 __u8 *digest;
3998
3999 /* Pull in the auth header, so we can do some more verification */
4000 auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
4001 chunk->subh.auth_hdr = auth_hdr;
4002 skb_pull(chunk->skb, sizeof(struct sctp_authhdr));
4003
02582e9b 4004 /* Make sure that we support the HMAC algorithm from the auth
bbd0d598
VY
4005 * chunk.
4006 */
4007 if (!sctp_auth_asoc_verify_hmac_id(asoc, auth_hdr->hmac_id))
4008 return SCTP_IERROR_AUTH_BAD_HMAC;
4009
4010 /* Make sure that the provided shared key identifier has been
4011 * configured
4012 */
4013 key_id = ntohs(auth_hdr->shkey_id);
4014 if (key_id != asoc->active_key_id && !sctp_auth_get_shkey(asoc, key_id))
4015 return SCTP_IERROR_AUTH_BAD_KEYID;
4016
4017
4018 /* Make sure that the length of the signature matches what
4019 * we expect.
4020 */
4021 sig_len = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_auth_chunk_t);
4022 hmac = sctp_auth_get_hmac(ntohs(auth_hdr->hmac_id));
4023 if (sig_len != hmac->hmac_len)
4024 return SCTP_IERROR_PROTO_VIOLATION;
4025
4026 /* Now that we've done validation checks, we can compute and
4027 * verify the hmac. The steps involved are:
4028 * 1. Save the digest from the chunk.
4029 * 2. Zero out the digest in the chunk.
4030 * 3. Compute the new digest
4031 * 4. Compare saved and new digests.
4032 */
4033 digest = auth_hdr->hmac;
4034 skb_pull(chunk->skb, sig_len);
4035
4036 save_digest = kmemdup(digest, sig_len, GFP_ATOMIC);
4037 if (!save_digest)
4038 goto nomem;
4039
4040 memset(digest, 0, sig_len);
4041
4042 sctp_auth_calculate_hmac(asoc, chunk->skb,
4043 (struct sctp_auth_chunk *)chunk->chunk_hdr,
4044 GFP_ATOMIC);
4045
4046 /* Discard the packet if the digests do not match */
4047 if (memcmp(save_digest, digest, sig_len)) {
4048 kfree(save_digest);
4049 return SCTP_IERROR_BAD_SIG;
4050 }
4051
4052 kfree(save_digest);
4053 chunk->auth = 1;
4054
4055 return SCTP_IERROR_NO_ERROR;
4056nomem:
4057 return SCTP_IERROR_NOMEM;
4058}
4059
24cb81a6
EB
4060sctp_disposition_t sctp_sf_eat_auth(struct net *net,
4061 const struct sctp_endpoint *ep,
bbd0d598
VY
4062 const struct sctp_association *asoc,
4063 const sctp_subtype_t type,
4064 void *arg,
4065 sctp_cmd_seq_t *commands)
4066{
4067 struct sctp_authhdr *auth_hdr;
4068 struct sctp_chunk *chunk = arg;
4069 struct sctp_chunk *err_chunk;
4070 sctp_ierror_t error;
4071
d2f19fa1
WY
4072 /* Make sure that the peer has AUTH capable */
4073 if (!asoc->peer.auth_capable)
24cb81a6 4074 return sctp_sf_unk_chunk(net, ep, asoc, type, arg, commands);
d2f19fa1 4075
bbd0d598
VY
4076 if (!sctp_vtag_verify(chunk, asoc)) {
4077 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
4078 SCTP_NULL());
24cb81a6 4079 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
bbd0d598
VY
4080 }
4081
4082 /* Make sure that the AUTH chunk has valid length. */
4083 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_auth_chunk)))
24cb81a6 4084 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
bbd0d598
VY
4085 commands);
4086
4087 auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
24cb81a6 4088 error = sctp_sf_authenticate(net, ep, asoc, type, chunk);
bbd0d598 4089 switch (error) {
7fd71b1e
JP
4090 case SCTP_IERROR_AUTH_BAD_HMAC:
4091 /* Generate the ERROR chunk and discard the rest
4092 * of the packet
4093 */
4094 err_chunk = sctp_make_op_error(asoc, chunk,
4095 SCTP_ERROR_UNSUP_HMAC,
4096 &auth_hdr->hmac_id,
4097 sizeof(__u16), 0);
4098 if (err_chunk) {
4099 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4100 SCTP_CHUNK(err_chunk));
4101 }
4102 /* Fall Through */
4103 case SCTP_IERROR_AUTH_BAD_KEYID:
4104 case SCTP_IERROR_BAD_SIG:
24cb81a6 4105 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
7fd71b1e
JP
4106
4107 case SCTP_IERROR_PROTO_VIOLATION:
24cb81a6 4108 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
7fd71b1e
JP
4109 commands);
4110
4111 case SCTP_IERROR_NOMEM:
4112 return SCTP_DISPOSITION_NOMEM;
4113
4114 default: /* Prevent gcc warnings */
4115 break;
bbd0d598
VY
4116 }
4117
65b07e5d
VY
4118 if (asoc->active_key_id != ntohs(auth_hdr->shkey_id)) {
4119 struct sctp_ulpevent *ev;
4120
4121 ev = sctp_ulpevent_make_authkey(asoc, ntohs(auth_hdr->shkey_id),
4122 SCTP_AUTH_NEWKEY, GFP_ATOMIC);
4123
4124 if (!ev)
4125 return -ENOMEM;
4126
4127 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
4128 SCTP_ULPEVENT(ev));
4129 }
4130
bbd0d598
VY
4131 return SCTP_DISPOSITION_CONSUME;
4132}
4133
1da177e4
LT
4134/*
4135 * Process an unknown chunk.
4136 *
4137 * Section: 3.2. Also, 2.1 in the implementor's guide.
4138 *
4139 * Chunk Types are encoded such that the highest-order two bits specify
4140 * the action that must be taken if the processing endpoint does not
4141 * recognize the Chunk Type.
4142 *
4143 * 00 - Stop processing this SCTP packet and discard it, do not process
4144 * any further chunks within it.
4145 *
4146 * 01 - Stop processing this SCTP packet and discard it, do not process
4147 * any further chunks within it, and report the unrecognized
4148 * chunk in an 'Unrecognized Chunk Type'.
4149 *
4150 * 10 - Skip this chunk and continue processing.
4151 *
4152 * 11 - Skip this chunk and continue processing, but report in an ERROR
4153 * Chunk using the 'Unrecognized Chunk Type' cause of error.
4154 *
4155 * The return value is the disposition of the chunk.
4156 */
24cb81a6
EB
4157sctp_disposition_t sctp_sf_unk_chunk(struct net *net,
4158 const struct sctp_endpoint *ep,
1da177e4
LT
4159 const struct sctp_association *asoc,
4160 const sctp_subtype_t type,
4161 void *arg,
4162 sctp_cmd_seq_t *commands)
4163{
4164 struct sctp_chunk *unk_chunk = arg;
4165 struct sctp_chunk *err_chunk;
4166 sctp_chunkhdr_t *hdr;
4167
bb33381d 4168 pr_debug("%s: processing unknown chunk id:%d\n", __func__, type.chunk);
1da177e4
LT
4169
4170 if (!sctp_vtag_verify(unk_chunk, asoc))
24cb81a6 4171 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
4172
4173 /* Make sure that the chunk has a valid length.
4174 * Since we don't know the chunk type, we use a general
4175 * chunkhdr structure to make a comparison.
4176 */
4177 if (!sctp_chunk_length_valid(unk_chunk, sizeof(sctp_chunkhdr_t)))
24cb81a6 4178 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4
LT
4179 commands);
4180
4181 switch (type.chunk & SCTP_CID_ACTION_MASK) {
4182 case SCTP_CID_ACTION_DISCARD:
4183 /* Discard the packet. */
24cb81a6 4184 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
4185 break;
4186 case SCTP_CID_ACTION_DISCARD_ERR:
1da177e4
LT
4187 /* Generate an ERROR chunk as response. */
4188 hdr = unk_chunk->chunk_hdr;
4189 err_chunk = sctp_make_op_error(asoc, unk_chunk,
4190 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
6383cfb3
VY
4191 WORD_ROUND(ntohs(hdr->length)),
4192 0);
1da177e4
LT
4193 if (err_chunk) {
4194 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4195 SCTP_CHUNK(err_chunk));
4196 }
2e3216cd
VY
4197
4198 /* Discard the packet. */
24cb81a6 4199 sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
4200 return SCTP_DISPOSITION_CONSUME;
4201 break;
4202 case SCTP_CID_ACTION_SKIP:
4203 /* Skip the chunk. */
4204 return SCTP_DISPOSITION_DISCARD;
4205 break;
4206 case SCTP_CID_ACTION_SKIP_ERR:
4207 /* Generate an ERROR chunk as response. */
4208 hdr = unk_chunk->chunk_hdr;
4209 err_chunk = sctp_make_op_error(asoc, unk_chunk,
4210 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
6383cfb3
VY
4211 WORD_ROUND(ntohs(hdr->length)),
4212 0);
1da177e4
LT
4213 if (err_chunk) {
4214 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4215 SCTP_CHUNK(err_chunk));
4216 }
4217 /* Skip the chunk. */
4218 return SCTP_DISPOSITION_CONSUME;
4219 break;
4220 default:
4221 break;
4222 }
4223
4224 return SCTP_DISPOSITION_DISCARD;
4225}
4226
4227/*
4228 * Discard the chunk.
4229 *
4230 * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2
4231 * [Too numerous to mention...]
4232 * Verification Tag: No verification needed.
4233 * Inputs
4234 * (endpoint, asoc, chunk)
4235 *
4236 * Outputs
4237 * (asoc, reply_msg, msg_up, timers, counters)
4238 *
4239 * The return value is the disposition of the chunk.
4240 */
24cb81a6
EB
4241sctp_disposition_t sctp_sf_discard_chunk(struct net *net,
4242 const struct sctp_endpoint *ep,
1da177e4
LT
4243 const struct sctp_association *asoc,
4244 const sctp_subtype_t type,
4245 void *arg,
4246 sctp_cmd_seq_t *commands)
4247{
ece25dfa
VY
4248 struct sctp_chunk *chunk = arg;
4249
4250 /* Make sure that the chunk has a valid length.
4251 * Since we don't know the chunk type, we use a general
4252 * chunkhdr structure to make a comparison.
4253 */
4254 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
24cb81a6 4255 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
ece25dfa
VY
4256 commands);
4257
bb33381d
DB
4258 pr_debug("%s: chunk:%d is discarded\n", __func__, type.chunk);
4259
1da177e4
LT
4260 return SCTP_DISPOSITION_DISCARD;
4261}
4262
4263/*
4264 * Discard the whole packet.
4265 *
4266 * Section: 8.4 2)
4267 *
4268 * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST
4269 * silently discard the OOTB packet and take no further action.
1da177e4
LT
4270 *
4271 * Verification Tag: No verification necessary
4272 *
4273 * Inputs
4274 * (endpoint, asoc, chunk)
4275 *
4276 * Outputs
4277 * (asoc, reply_msg, msg_up, timers, counters)
4278 *
4279 * The return value is the disposition of the chunk.
4280 */
24cb81a6
EB
4281sctp_disposition_t sctp_sf_pdiscard(struct net *net,
4282 const struct sctp_endpoint *ep,
1da177e4
LT
4283 const struct sctp_association *asoc,
4284 const sctp_subtype_t type,
4285 void *arg,
4286 sctp_cmd_seq_t *commands)
4287{
24cb81a6 4288 SCTP_INC_STATS(net, SCTP_MIB_IN_PKT_DISCARDS);
1da177e4
LT
4289 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
4290
4291 return SCTP_DISPOSITION_CONSUME;
4292}
4293
4294
4295/*
4296 * The other end is violating protocol.
4297 *
4298 * Section: Not specified
4299 * Verification Tag: Not specified
4300 * Inputs
4301 * (endpoint, asoc, chunk)
4302 *
4303 * Outputs
4304 * (asoc, reply_msg, msg_up, timers, counters)
4305 *
4306 * We simply tag the chunk as a violation. The state machine will log
4307 * the violation and continue.
4308 */
24cb81a6
EB
4309sctp_disposition_t sctp_sf_violation(struct net *net,
4310 const struct sctp_endpoint *ep,
1da177e4
LT
4311 const struct sctp_association *asoc,
4312 const sctp_subtype_t type,
4313 void *arg,
4314 sctp_cmd_seq_t *commands)
4315{
ece25dfa
VY
4316 struct sctp_chunk *chunk = arg;
4317
4318 /* Make sure that the chunk has a valid length. */
4319 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
24cb81a6 4320 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
ece25dfa
VY
4321 commands);
4322
1da177e4
LT
4323 return SCTP_DISPOSITION_VIOLATION;
4324}
4325
1da177e4 4326/*
aecedeab 4327 * Common function to handle a protocol violation.
1da177e4 4328 */
aecedeab 4329static sctp_disposition_t sctp_sf_abort_violation(
24cb81a6 4330 struct net *net,
ece25dfa 4331 const struct sctp_endpoint *ep,
1da177e4 4332 const struct sctp_association *asoc,
1da177e4 4333 void *arg,
aecedeab
WY
4334 sctp_cmd_seq_t *commands,
4335 const __u8 *payload,
4336 const size_t paylen)
1da177e4 4337{
ece25dfa 4338 struct sctp_packet *packet = NULL;
1da177e4
LT
4339 struct sctp_chunk *chunk = arg;
4340 struct sctp_chunk *abort = NULL;
1da177e4 4341
bbd0d598
VY
4342 /* SCTP-AUTH, Section 6.3:
4343 * It should be noted that if the receiver wants to tear
4344 * down an association in an authenticated way only, the
4345 * handling of malformed packets should not result in
4346 * tearing down the association.
4347 *
4348 * This means that if we only want to abort associations
4349 * in an authenticated way (i.e AUTH+ABORT), then we
25985edc 4350 * can't destroy this association just because the packet
bbd0d598
VY
4351 * was malformed.
4352 */
4353 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
4354 goto discard;
4355
9abed245
JJ
4356 /* Make the abort chunk. */
4357 abort = sctp_make_abort_violation(asoc, chunk, payload, paylen);
4358 if (!abort)
4359 goto nomem;
4360
ece25dfa 4361 if (asoc) {
f4ad85ca
GJ
4362 /* Treat INIT-ACK as a special case during COOKIE-WAIT. */
4363 if (chunk->chunk_hdr->type == SCTP_CID_INIT_ACK &&
4364 !asoc->peer.i.init_tag) {
4365 sctp_initack_chunk_t *initack;
4366
4367 initack = (sctp_initack_chunk_t *)chunk->chunk_hdr;
4368 if (!sctp_chunk_length_valid(chunk,
4369 sizeof(sctp_initack_chunk_t)))
4370 abort->chunk_hdr->flags |= SCTP_CHUNK_FLAG_T;
4371 else {
4372 unsigned int inittag;
4373
4374 inittag = ntohl(initack->init_hdr.init_tag);
4375 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_INITTAG,
4376 SCTP_U32(inittag));
4377 }
4378 }
4379
ece25dfa 4380 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
b01a2407 4381 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
1da177e4 4382
ece25dfa
VY
4383 if (asoc->state <= SCTP_STATE_COOKIE_ECHOED) {
4384 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4385 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4386 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4387 SCTP_ERROR(ECONNREFUSED));
4388 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
4389 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4390 } else {
4391 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4392 SCTP_ERROR(ECONNABORTED));
4393 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4394 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
b01a2407 4395 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
ece25dfa 4396 }
1da177e4 4397 } else {
2ce95503 4398 packet = sctp_ootb_pkt_new(net, asoc, chunk);
ece25dfa
VY
4399
4400 if (!packet)
4401 goto nomem_pkt;
4402
4403 if (sctp_test_T_bit(abort))
4404 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
4405
4406 abort->skb->sk = ep->base.sk;
4407
4408 sctp_packet_append_chunk(packet, abort);
4409
4410 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
4411 SCTP_PACKET(packet));
4412
b01a2407 4413 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
1da177e4
LT
4414 }
4415
b01a2407 4416 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
d808ad9a 4417
56eb82bb 4418discard:
24cb81a6 4419 sctp_sf_pdiscard(net, ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
1da177e4
LT
4420 return SCTP_DISPOSITION_ABORT;
4421
ece25dfa
VY
4422nomem_pkt:
4423 sctp_chunk_free(abort);
1da177e4
LT
4424nomem:
4425 return SCTP_DISPOSITION_NOMEM;
4426}
4427
aecedeab
WY
4428/*
4429 * Handle a protocol violation when the chunk length is invalid.
025dfdaf 4430 * "Invalid" length is identified as smaller than the minimal length a
aecedeab 4431 * given chunk can be. For example, a SACK chunk has invalid length
025dfdaf 4432 * if its length is set to be smaller than the size of sctp_sack_chunk_t.
aecedeab
WY
4433 *
4434 * We inform the other end by sending an ABORT with a Protocol Violation
4435 * error code.
4436 *
4437 * Section: Not specified
4438 * Verification Tag: Nothing to do
4439 * Inputs
4440 * (endpoint, asoc, chunk)
4441 *
4442 * Outputs
4443 * (reply_msg, msg_up, counters)
4444 *
4445 * Generate an ABORT chunk and terminate the association.
4446 */
4447static sctp_disposition_t sctp_sf_violation_chunklen(
24cb81a6 4448 struct net *net,
aecedeab
WY
4449 const struct sctp_endpoint *ep,
4450 const struct sctp_association *asoc,
4451 const sctp_subtype_t type,
4452 void *arg,
4453 sctp_cmd_seq_t *commands)
4454{
2444844c 4455 static const char err_str[]="The following chunk had invalid length:";
aecedeab 4456
24cb81a6 4457 return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str,
aecedeab
WY
4458 sizeof(err_str));
4459}
4460
6f4c618d
WY
4461/*
4462 * Handle a protocol violation when the parameter length is invalid.
33c7cfdb
SW
4463 * If the length is smaller than the minimum length of a given parameter,
4464 * or accumulated length in multi parameters exceeds the end of the chunk,
4465 * the length is considered as invalid.
6f4c618d
WY
4466 */
4467static sctp_disposition_t sctp_sf_violation_paramlen(
24cb81a6 4468 struct net *net,
6f4c618d
WY
4469 const struct sctp_endpoint *ep,
4470 const struct sctp_association *asoc,
4471 const sctp_subtype_t type,
ba016670
WY
4472 void *arg, void *ext,
4473 sctp_cmd_seq_t *commands)
4474{
4475 struct sctp_chunk *chunk = arg;
4476 struct sctp_paramhdr *param = ext;
4477 struct sctp_chunk *abort = NULL;
6f4c618d 4478
ba016670
WY
4479 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
4480 goto discard;
4481
4482 /* Make the abort chunk. */
4483 abort = sctp_make_violation_paramlen(asoc, chunk, param);
4484 if (!abort)
4485 goto nomem;
4486
4487 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
b01a2407 4488 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
ba016670
WY
4489
4490 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4491 SCTP_ERROR(ECONNABORTED));
4492 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4493 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
b01a2407
EB
4494 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
4495 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
ba016670
WY
4496
4497discard:
24cb81a6 4498 sctp_sf_pdiscard(net, ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
ba016670
WY
4499 return SCTP_DISPOSITION_ABORT;
4500nomem:
4501 return SCTP_DISPOSITION_NOMEM;
6f4c618d
WY
4502}
4503
aecedeab
WY
4504/* Handle a protocol violation when the peer trying to advance the
4505 * cumulative tsn ack to a point beyond the max tsn currently sent.
4506 *
4507 * We inform the other end by sending an ABORT with a Protocol Violation
4508 * error code.
4509 */
4510static sctp_disposition_t sctp_sf_violation_ctsn(
24cb81a6 4511 struct net *net,
aecedeab
WY
4512 const struct sctp_endpoint *ep,
4513 const struct sctp_association *asoc,
4514 const sctp_subtype_t type,
4515 void *arg,
4516 sctp_cmd_seq_t *commands)
4517{
2444844c 4518 static const char err_str[]="The cumulative tsn ack beyond the max tsn currently sent:";
aecedeab 4519
24cb81a6 4520 return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str,
aecedeab
WY
4521 sizeof(err_str));
4522}
4523
ece25dfa 4524/* Handle protocol violation of an invalid chunk bundling. For example,
25985edc 4525 * when we have an association and we receive bundled INIT-ACK, or
ece25dfa 4526 * SHUDOWN-COMPLETE, our peer is clearly violationg the "MUST NOT bundle"
25985edc 4527 * statement from the specs. Additionally, there might be an attacker
ece25dfa
VY
4528 * on the path and we may not want to continue this communication.
4529 */
4530static sctp_disposition_t sctp_sf_violation_chunk(
24cb81a6 4531 struct net *net,
ece25dfa
VY
4532 const struct sctp_endpoint *ep,
4533 const struct sctp_association *asoc,
4534 const sctp_subtype_t type,
4535 void *arg,
4536 sctp_cmd_seq_t *commands)
4537{
2444844c 4538 static const char err_str[]="The following chunk violates protocol:";
ece25dfa
VY
4539
4540 if (!asoc)
24cb81a6 4541 return sctp_sf_violation(net, ep, asoc, type, arg, commands);
ece25dfa 4542
24cb81a6 4543 return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str,
ece25dfa
VY
4544 sizeof(err_str));
4545}
1da177e4
LT
4546/***************************************************************************
4547 * These are the state functions for handling primitive (Section 10) events.
4548 ***************************************************************************/
4549/*
4550 * sctp_sf_do_prm_asoc
4551 *
4552 * Section: 10.1 ULP-to-SCTP
4553 * B) Associate
4554 *
4555 * Format: ASSOCIATE(local SCTP instance name, destination transport addr,
4556 * outbound stream count)
4557 * -> association id [,destination transport addr list] [,outbound stream
4558 * count]
4559 *
4560 * This primitive allows the upper layer to initiate an association to a
4561 * specific peer endpoint.
4562 *
4563 * The peer endpoint shall be specified by one of the transport addresses
4564 * which defines the endpoint (see Section 1.4). If the local SCTP
4565 * instance has not been initialized, the ASSOCIATE is considered an
4566 * error.
4567 * [This is not relevant for the kernel implementation since we do all
4568 * initialization at boot time. It we hadn't initialized we wouldn't
4569 * get anywhere near this code.]
4570 *
4571 * An association id, which is a local handle to the SCTP association,
4572 * will be returned on successful establishment of the association. If
4573 * SCTP is not able to open an SCTP association with the peer endpoint,
4574 * an error is returned.
4575 * [In the kernel implementation, the struct sctp_association needs to
4576 * be created BEFORE causing this primitive to run.]
4577 *
4578 * Other association parameters may be returned, including the
4579 * complete destination transport addresses of the peer as well as the
4580 * outbound stream count of the local endpoint. One of the transport
4581 * address from the returned destination addresses will be selected by
4582 * the local endpoint as default primary path for sending SCTP packets
4583 * to this peer. The returned "destination transport addr list" can
4584 * be used by the ULP to change the default primary path or to force
4585 * sending a packet to a specific transport address. [All of this
4586 * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING
4587 * function.]
4588 *
4589 * Mandatory attributes:
4590 *
4591 * o local SCTP instance name - obtained from the INITIALIZE operation.
4592 * [This is the argument asoc.]
4593 * o destination transport addr - specified as one of the transport
4594 * addresses of the peer endpoint with which the association is to be
4595 * established.
4596 * [This is asoc->peer.active_path.]
4597 * o outbound stream count - the number of outbound streams the ULP
4598 * would like to open towards this peer endpoint.
4599 * [BUG: This is not currently implemented.]
4600 * Optional attributes:
4601 *
4602 * None.
4603 *
4604 * The return value is a disposition.
4605 */
24cb81a6
EB
4606sctp_disposition_t sctp_sf_do_prm_asoc(struct net *net,
4607 const struct sctp_endpoint *ep,
1da177e4
LT
4608 const struct sctp_association *asoc,
4609 const sctp_subtype_t type,
4610 void *arg,
4611 sctp_cmd_seq_t *commands)
4612{
4613 struct sctp_chunk *repl;
ab38fb04 4614 struct sctp_association* my_asoc;
1da177e4
LT
4615
4616 /* The comment below says that we enter COOKIE-WAIT AFTER
4617 * sending the INIT, but that doesn't actually work in our
4618 * implementation...
4619 */
4620 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4621 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
4622
4623 /* RFC 2960 5.1 Normal Establishment of an Association
4624 *
4625 * A) "A" first sends an INIT chunk to "Z". In the INIT, "A"
4626 * must provide its Verification Tag (Tag_A) in the Initiate
4627 * Tag field. Tag_A SHOULD be a random number in the range of
4628 * 1 to 4294967295 (see 5.3.1 for Tag value selection). ...
4629 */
4630
4631 repl = sctp_make_init(asoc, &asoc->base.bind_addr, GFP_ATOMIC, 0);
4632 if (!repl)
4633 goto nomem;
4634
405426f6
DB
4635 /* Choose transport for INIT. */
4636 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
4637 SCTP_CHUNK(repl));
4638
1da177e4
LT
4639 /* Cast away the const modifier, as we want to just
4640 * rerun it through as a sideffect.
4641 */
ab38fb04
VY
4642 my_asoc = (struct sctp_association *)asoc;
4643 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(my_asoc));
1da177e4
LT
4644
4645 /* After sending the INIT, "A" starts the T1-init timer and
4646 * enters the COOKIE-WAIT state.
4647 */
4648 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4649 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4650 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
4651 return SCTP_DISPOSITION_CONSUME;
4652
4653nomem:
4654 return SCTP_DISPOSITION_NOMEM;
4655}
4656
4657/*
4658 * Process the SEND primitive.
4659 *
4660 * Section: 10.1 ULP-to-SCTP
4661 * E) Send
4662 *
4663 * Format: SEND(association id, buffer address, byte count [,context]
4664 * [,stream id] [,life time] [,destination transport address]
4665 * [,unorder flag] [,no-bundle flag] [,payload protocol-id] )
4666 * -> result
4667 *
4668 * This is the main method to send user data via SCTP.
4669 *
4670 * Mandatory attributes:
4671 *
4672 * o association id - local handle to the SCTP association
4673 *
4674 * o buffer address - the location where the user message to be
4675 * transmitted is stored;
4676 *
4677 * o byte count - The size of the user data in number of bytes;
4678 *
4679 * Optional attributes:
4680 *
4681 * o context - an optional 32 bit integer that will be carried in the
4682 * sending failure notification to the ULP if the transportation of
4683 * this User Message fails.
4684 *
4685 * o stream id - to indicate which stream to send the data on. If not
4686 * specified, stream 0 will be used.
4687 *
4688 * o life time - specifies the life time of the user data. The user data
4689 * will not be sent by SCTP after the life time expires. This
4690 * parameter can be used to avoid efforts to transmit stale
4691 * user messages. SCTP notifies the ULP if the data cannot be
4692 * initiated to transport (i.e. sent to the destination via SCTP's
4693 * send primitive) within the life time variable. However, the
4694 * user data will be transmitted if SCTP has attempted to transmit a
4695 * chunk before the life time expired.
4696 *
4697 * o destination transport address - specified as one of the destination
4698 * transport addresses of the peer endpoint to which this packet
4699 * should be sent. Whenever possible, SCTP should use this destination
4700 * transport address for sending the packets, instead of the current
4701 * primary path.
4702 *
4703 * o unorder flag - this flag, if present, indicates that the user
4704 * would like the data delivered in an unordered fashion to the peer
4705 * (i.e., the U flag is set to 1 on all DATA chunks carrying this
4706 * message).
4707 *
4708 * o no-bundle flag - instructs SCTP not to bundle this user data with
4709 * other outbound DATA chunks. SCTP MAY still bundle even when
4710 * this flag is present, when faced with network congestion.
4711 *
4712 * o payload protocol-id - A 32 bit unsigned integer that is to be
4713 * passed to the peer indicating the type of payload protocol data
4714 * being transmitted. This value is passed as opaque data by SCTP.
4715 *
4716 * The return value is the disposition.
4717 */
24cb81a6
EB
4718sctp_disposition_t sctp_sf_do_prm_send(struct net *net,
4719 const struct sctp_endpoint *ep,
1da177e4
LT
4720 const struct sctp_association *asoc,
4721 const sctp_subtype_t type,
4722 void *arg,
4723 sctp_cmd_seq_t *commands)
4724{
9c5c62be 4725 struct sctp_datamsg *msg = arg;
1da177e4 4726
9c5c62be 4727 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_MSG, SCTP_DATAMSG(msg));
1da177e4
LT
4728 return SCTP_DISPOSITION_CONSUME;
4729}
4730
4731/*
4732 * Process the SHUTDOWN primitive.
4733 *
4734 * Section: 10.1:
4735 * C) Shutdown
4736 *
4737 * Format: SHUTDOWN(association id)
4738 * -> result
4739 *
4740 * Gracefully closes an association. Any locally queued user data
4741 * will be delivered to the peer. The association will be terminated only
4742 * after the peer acknowledges all the SCTP packets sent. A success code
4743 * will be returned on successful termination of the association. If
4744 * attempting to terminate the association results in a failure, an error
4745 * code shall be returned.
4746 *
4747 * Mandatory attributes:
4748 *
4749 * o association id - local handle to the SCTP association
4750 *
4751 * Optional attributes:
4752 *
4753 * None.
4754 *
4755 * The return value is the disposition.
4756 */
4757sctp_disposition_t sctp_sf_do_9_2_prm_shutdown(
24cb81a6 4758 struct net *net,
1da177e4
LT
4759 const struct sctp_endpoint *ep,
4760 const struct sctp_association *asoc,
4761 const sctp_subtype_t type,
4762 void *arg,
4763 sctp_cmd_seq_t *commands)
4764{
4765 int disposition;
4766
4767 /* From 9.2 Shutdown of an Association
4768 * Upon receipt of the SHUTDOWN primitive from its upper
4769 * layer, the endpoint enters SHUTDOWN-PENDING state and
4770 * remains there until all outstanding data has been
4771 * acknowledged by its peer. The endpoint accepts no new data
4772 * from its upper layer, but retransmits data to the far end
4773 * if necessary to fill gaps.
4774 */
4775 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4776 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
4777
1da177e4
LT
4778 disposition = SCTP_DISPOSITION_CONSUME;
4779 if (sctp_outq_is_empty(&asoc->outqueue)) {
24cb81a6 4780 disposition = sctp_sf_do_9_2_start_shutdown(net, ep, asoc, type,
1da177e4
LT
4781 arg, commands);
4782 }
4783 return disposition;
4784}
4785
4786/*
4787 * Process the ABORT primitive.
4788 *
4789 * Section: 10.1:
4790 * C) Abort
4791 *
4792 * Format: Abort(association id [, cause code])
4793 * -> result
4794 *
4795 * Ungracefully closes an association. Any locally queued user data
4796 * will be discarded and an ABORT chunk is sent to the peer. A success code
4797 * will be returned on successful abortion of the association. If
4798 * attempting to abort the association results in a failure, an error
4799 * code shall be returned.
4800 *
4801 * Mandatory attributes:
4802 *
4803 * o association id - local handle to the SCTP association
4804 *
4805 * Optional attributes:
4806 *
4807 * o cause code - reason of the abort to be passed to the peer
4808 *
4809 * None.
4810 *
4811 * The return value is the disposition.
4812 */
4813sctp_disposition_t sctp_sf_do_9_1_prm_abort(
24cb81a6 4814 struct net *net,
1da177e4
LT
4815 const struct sctp_endpoint *ep,
4816 const struct sctp_association *asoc,
4817 const sctp_subtype_t type,
4818 void *arg,
4819 sctp_cmd_seq_t *commands)
4820{
4821 /* From 9.1 Abort of an Association
4822 * Upon receipt of the ABORT primitive from its upper
4823 * layer, the endpoint enters CLOSED state and
4824 * discard all outstanding data has been
4825 * acknowledged by its peer. The endpoint accepts no new data
4826 * from its upper layer, but retransmits data to the far end
4827 * if necessary to fill gaps.
4828 */
c164a9ba 4829 struct sctp_chunk *abort = arg;
1da177e4
LT
4830 sctp_disposition_t retval;
4831
4832 retval = SCTP_DISPOSITION_CONSUME;
4833
c164a9ba 4834 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
1da177e4
LT
4835
4836 /* Even if we can't send the ABORT due to low memory delete the
4837 * TCB. This is a departure from our typical NOMEM handling.
4838 */
4839
8de8c873
SS
4840 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4841 SCTP_ERROR(ECONNABORTED));
1da177e4
LT
4842 /* Delete the established association. */
4843 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5be291fe 4844 SCTP_PERR(SCTP_ERROR_USER_ABORT));
1da177e4 4845
b01a2407
EB
4846 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
4847 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
1da177e4
LT
4848
4849 return retval;
4850}
4851
4852/* We tried an illegal operation on an association which is closed. */
24cb81a6
EB
4853sctp_disposition_t sctp_sf_error_closed(struct net *net,
4854 const struct sctp_endpoint *ep,
1da177e4
LT
4855 const struct sctp_association *asoc,
4856 const sctp_subtype_t type,
4857 void *arg,
4858 sctp_cmd_seq_t *commands)
4859{
4860 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, SCTP_ERROR(-EINVAL));
4861 return SCTP_DISPOSITION_CONSUME;
4862}
4863
4864/* We tried an illegal operation on an association which is shutting
4865 * down.
4866 */
24cb81a6
EB
4867sctp_disposition_t sctp_sf_error_shutdown(struct net *net,
4868 const struct sctp_endpoint *ep,
1da177e4
LT
4869 const struct sctp_association *asoc,
4870 const sctp_subtype_t type,
4871 void *arg,
4872 sctp_cmd_seq_t *commands)
4873{
4874 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR,
4875 SCTP_ERROR(-ESHUTDOWN));
4876 return SCTP_DISPOSITION_CONSUME;
4877}
4878
4879/*
4880 * sctp_cookie_wait_prm_shutdown
4881 *
4882 * Section: 4 Note: 2
4883 * Verification Tag:
4884 * Inputs
4885 * (endpoint, asoc)
4886 *
4887 * The RFC does not explicitly address this issue, but is the route through the
4888 * state table when someone issues a shutdown while in COOKIE_WAIT state.
4889 *
4890 * Outputs
4891 * (timers)
4892 */
4893sctp_disposition_t sctp_sf_cookie_wait_prm_shutdown(
24cb81a6 4894 struct net *net,
1da177e4
LT
4895 const struct sctp_endpoint *ep,
4896 const struct sctp_association *asoc,
4897 const sctp_subtype_t type,
4898 void *arg,
4899 sctp_cmd_seq_t *commands)
4900{
4901 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4902 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4903
4904 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4905 SCTP_STATE(SCTP_STATE_CLOSED));
4906
b01a2407 4907 SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS);
1da177e4
LT
4908
4909 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
4910
4911 return SCTP_DISPOSITION_DELETE_TCB;
4912}
4913
4914/*
4915 * sctp_cookie_echoed_prm_shutdown
4916 *
4917 * Section: 4 Note: 2
4918 * Verification Tag:
4919 * Inputs
4920 * (endpoint, asoc)
4921 *
4922 * The RFC does not explcitly address this issue, but is the route through the
4923 * state table when someone issues a shutdown while in COOKIE_ECHOED state.
4924 *
4925 * Outputs
4926 * (timers)
4927 */
4928sctp_disposition_t sctp_sf_cookie_echoed_prm_shutdown(
24cb81a6 4929 struct net *net,
1da177e4
LT
4930 const struct sctp_endpoint *ep,
4931 const struct sctp_association *asoc,
4932 const sctp_subtype_t type,
4933 void *arg, sctp_cmd_seq_t *commands)
4934{
4935 /* There is a single T1 timer, so we should be able to use
4936 * common function with the COOKIE-WAIT state.
4937 */
24cb81a6 4938 return sctp_sf_cookie_wait_prm_shutdown(net, ep, asoc, type, arg, commands);
1da177e4
LT
4939}
4940
4941/*
4942 * sctp_sf_cookie_wait_prm_abort
4943 *
4944 * Section: 4 Note: 2
4945 * Verification Tag:
4946 * Inputs
4947 * (endpoint, asoc)
4948 *
4949 * The RFC does not explicitly address this issue, but is the route through the
4950 * state table when someone issues an abort while in COOKIE_WAIT state.
4951 *
4952 * Outputs
4953 * (timers)
4954 */
4955sctp_disposition_t sctp_sf_cookie_wait_prm_abort(
24cb81a6 4956 struct net *net,
1da177e4
LT
4957 const struct sctp_endpoint *ep,
4958 const struct sctp_association *asoc,
4959 const sctp_subtype_t type,
4960 void *arg,
4961 sctp_cmd_seq_t *commands)
4962{
c164a9ba 4963 struct sctp_chunk *abort = arg;
1da177e4
LT
4964 sctp_disposition_t retval;
4965
4966 /* Stop T1-init timer */
4967 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4968 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4969 retval = SCTP_DISPOSITION_CONSUME;
4970
c164a9ba 4971 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
1da177e4
LT
4972
4973 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4974 SCTP_STATE(SCTP_STATE_CLOSED));
4975
b01a2407 4976 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
1da177e4
LT
4977
4978 /* Even if we can't send the ABORT due to low memory delete the
4979 * TCB. This is a departure from our typical NOMEM handling.
4980 */
4981
8de8c873
SS
4982 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4983 SCTP_ERROR(ECONNREFUSED));
1da177e4
LT
4984 /* Delete the established association. */
4985 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
dc251b2b 4986 SCTP_PERR(SCTP_ERROR_USER_ABORT));
1da177e4
LT
4987
4988 return retval;
4989}
4990
4991/*
4992 * sctp_sf_cookie_echoed_prm_abort
4993 *
4994 * Section: 4 Note: 3
4995 * Verification Tag:
4996 * Inputs
4997 * (endpoint, asoc)
4998 *
4999 * The RFC does not explcitly address this issue, but is the route through the
5000 * state table when someone issues an abort while in COOKIE_ECHOED state.
5001 *
5002 * Outputs
5003 * (timers)
5004 */
5005sctp_disposition_t sctp_sf_cookie_echoed_prm_abort(
24cb81a6 5006 struct net *net,
1da177e4
LT
5007 const struct sctp_endpoint *ep,
5008 const struct sctp_association *asoc,
5009 const sctp_subtype_t type,
5010 void *arg,
5011 sctp_cmd_seq_t *commands)
5012{
5013 /* There is a single T1 timer, so we should be able to use
5014 * common function with the COOKIE-WAIT state.
5015 */
24cb81a6 5016 return sctp_sf_cookie_wait_prm_abort(net, ep, asoc, type, arg, commands);
1da177e4
LT
5017}
5018
5019/*
5020 * sctp_sf_shutdown_pending_prm_abort
5021 *
5022 * Inputs
5023 * (endpoint, asoc)
5024 *
5025 * The RFC does not explicitly address this issue, but is the route through the
5026 * state table when someone issues an abort while in SHUTDOWN-PENDING state.
5027 *
5028 * Outputs
5029 * (timers)
5030 */
5031sctp_disposition_t sctp_sf_shutdown_pending_prm_abort(
24cb81a6 5032 struct net *net,
1da177e4
LT
5033 const struct sctp_endpoint *ep,
5034 const struct sctp_association *asoc,
5035 const sctp_subtype_t type,
5036 void *arg,
5037 sctp_cmd_seq_t *commands)
5038{
5039 /* Stop the T5-shutdown guard timer. */
5040 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5041 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5042
24cb81a6 5043 return sctp_sf_do_9_1_prm_abort(net, ep, asoc, type, arg, commands);
1da177e4
LT
5044}
5045
5046/*
5047 * sctp_sf_shutdown_sent_prm_abort
5048 *
5049 * Inputs
5050 * (endpoint, asoc)
5051 *
5052 * The RFC does not explicitly address this issue, but is the route through the
5053 * state table when someone issues an abort while in SHUTDOWN-SENT state.
5054 *
5055 * Outputs
5056 * (timers)
5057 */
5058sctp_disposition_t sctp_sf_shutdown_sent_prm_abort(
24cb81a6 5059 struct net *net,
1da177e4
LT
5060 const struct sctp_endpoint *ep,
5061 const struct sctp_association *asoc,
5062 const sctp_subtype_t type,
5063 void *arg,
5064 sctp_cmd_seq_t *commands)
5065{
5066 /* Stop the T2-shutdown timer. */
5067 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5068 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5069
5070 /* Stop the T5-shutdown guard timer. */
5071 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5072 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5073
24cb81a6 5074 return sctp_sf_do_9_1_prm_abort(net, ep, asoc, type, arg, commands);
1da177e4
LT
5075}
5076
5077/*
5078 * sctp_sf_cookie_echoed_prm_abort
5079 *
5080 * Inputs
5081 * (endpoint, asoc)
5082 *
5083 * The RFC does not explcitly address this issue, but is the route through the
5084 * state table when someone issues an abort while in COOKIE_ECHOED state.
5085 *
5086 * Outputs
5087 * (timers)
5088 */
5089sctp_disposition_t sctp_sf_shutdown_ack_sent_prm_abort(
24cb81a6 5090 struct net *net,
1da177e4
LT
5091 const struct sctp_endpoint *ep,
5092 const struct sctp_association *asoc,
5093 const sctp_subtype_t type,
5094 void *arg,
5095 sctp_cmd_seq_t *commands)
5096{
5097 /* The same T2 timer, so we should be able to use
5098 * common function with the SHUTDOWN-SENT state.
5099 */
24cb81a6 5100 return sctp_sf_shutdown_sent_prm_abort(net, ep, asoc, type, arg, commands);
1da177e4
LT
5101}
5102
5103/*
5104 * Process the REQUESTHEARTBEAT primitive
5105 *
5106 * 10.1 ULP-to-SCTP
5107 * J) Request Heartbeat
5108 *
5109 * Format: REQUESTHEARTBEAT(association id, destination transport address)
5110 *
5111 * -> result
5112 *
5113 * Instructs the local endpoint to perform a HeartBeat on the specified
5114 * destination transport address of the given association. The returned
5115 * result should indicate whether the transmission of the HEARTBEAT
5116 * chunk to the destination address is successful.
5117 *
5118 * Mandatory attributes:
5119 *
5120 * o association id - local handle to the SCTP association
5121 *
5122 * o destination transport address - the transport address of the
5123 * association on which a heartbeat should be issued.
5124 */
5125sctp_disposition_t sctp_sf_do_prm_requestheartbeat(
24cb81a6 5126 struct net *net,
1da177e4
LT
5127 const struct sctp_endpoint *ep,
5128 const struct sctp_association *asoc,
5129 const sctp_subtype_t type,
5130 void *arg,
5131 sctp_cmd_seq_t *commands)
5132{
fb78525a
VY
5133 if (SCTP_DISPOSITION_NOMEM == sctp_sf_heartbeat(ep, asoc, type,
5134 (struct sctp_transport *)arg, commands))
5135 return SCTP_DISPOSITION_NOMEM;
5136
5137 /*
5138 * RFC 2960 (bis), section 8.3
5139 *
5140 * D) Request an on-demand HEARTBEAT on a specific destination
5141 * transport address of a given association.
5142 *
5143 * The endpoint should increment the respective error counter of
5144 * the destination transport address each time a HEARTBEAT is sent
5145 * to that address and not acknowledged within one RTO.
5146 *
5147 */
7e99013a 5148 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_HB_SENT,
fb78525a
VY
5149 SCTP_TRANSPORT(arg));
5150 return SCTP_DISPOSITION_CONSUME;
1da177e4
LT
5151}
5152
5153/*
5154 * ADDIP Section 4.1 ASCONF Chunk Procedures
5155 * When an endpoint has an ASCONF signaled change to be sent to the
5156 * remote endpoint it should do A1 to A9
5157 */
24cb81a6
EB
5158sctp_disposition_t sctp_sf_do_prm_asconf(struct net *net,
5159 const struct sctp_endpoint *ep,
1da177e4
LT
5160 const struct sctp_association *asoc,
5161 const sctp_subtype_t type,
5162 void *arg,
5163 sctp_cmd_seq_t *commands)
5164{
5165 struct sctp_chunk *chunk = arg;
5166
5167 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
5168 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
5169 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
5170 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
5171 return SCTP_DISPOSITION_CONSUME;
5172}
5173
5174/*
5175 * Ignore the primitive event
5176 *
5177 * The return value is the disposition of the primitive.
5178 */
5179sctp_disposition_t sctp_sf_ignore_primitive(
24cb81a6 5180 struct net *net,
1da177e4
LT
5181 const struct sctp_endpoint *ep,
5182 const struct sctp_association *asoc,
5183 const sctp_subtype_t type,
5184 void *arg,
5185 sctp_cmd_seq_t *commands)
5186{
bb33381d
DB
5187 pr_debug("%s: primitive type:%d is ignored\n", __func__,
5188 type.primitive);
5189
1da177e4
LT
5190 return SCTP_DISPOSITION_DISCARD;
5191}
5192
5193/***************************************************************************
5194 * These are the state functions for the OTHER events.
5195 ***************************************************************************/
5196
e1cdd553
WY
5197/*
5198 * When the SCTP stack has no more user data to send or retransmit, this
5199 * notification is given to the user. Also, at the time when a user app
5200 * subscribes to this event, if there is no data to be sent or
5201 * retransmit, the stack will immediately send up this notification.
5202 */
5203sctp_disposition_t sctp_sf_do_no_pending_tsn(
24cb81a6 5204 struct net *net,
e1cdd553
WY
5205 const struct sctp_endpoint *ep,
5206 const struct sctp_association *asoc,
5207 const sctp_subtype_t type,
5208 void *arg,
5209 sctp_cmd_seq_t *commands)
5210{
5211 struct sctp_ulpevent *event;
5212
5213 event = sctp_ulpevent_make_sender_dry_event(asoc, GFP_ATOMIC);
5214 if (!event)
5215 return SCTP_DISPOSITION_NOMEM;
5216
5217 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(event));
5218
5219 return SCTP_DISPOSITION_CONSUME;
5220}
5221
1da177e4
LT
5222/*
5223 * Start the shutdown negotiation.
5224 *
5225 * From Section 9.2:
5226 * Once all its outstanding data has been acknowledged, the endpoint
5227 * shall send a SHUTDOWN chunk to its peer including in the Cumulative
5228 * TSN Ack field the last sequential TSN it has received from the peer.
5229 * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT
5230 * state. If the timer expires, the endpoint must re-send the SHUTDOWN
5231 * with the updated last sequential TSN received from its peer.
5232 *
5233 * The return value is the disposition.
5234 */
5235sctp_disposition_t sctp_sf_do_9_2_start_shutdown(
24cb81a6 5236 struct net *net,
1da177e4
LT
5237 const struct sctp_endpoint *ep,
5238 const struct sctp_association *asoc,
5239 const sctp_subtype_t type,
5240 void *arg,
5241 sctp_cmd_seq_t *commands)
5242{
5243 struct sctp_chunk *reply;
5244
5245 /* Once all its outstanding data has been acknowledged, the
5246 * endpoint shall send a SHUTDOWN chunk to its peer including
5247 * in the Cumulative TSN Ack field the last sequential TSN it
5248 * has received from the peer.
5249 */
5250 reply = sctp_make_shutdown(asoc, NULL);
5251 if (!reply)
5252 goto nomem;
5253
5254 /* Set the transport for the SHUTDOWN chunk and the timeout for the
5255 * T2-shutdown timer.
5256 */
5257 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5258
5259 /* It shall then start the T2-shutdown timer */
5260 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
5261 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5262
536428a9
WY
5263 /* RFC 4960 Section 9.2
5264 * The sender of the SHUTDOWN MAY also start an overall guard timer
5265 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5266 */
f8d96052 5267 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
536428a9
WY
5268 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5269
1da177e4
LT
5270 if (asoc->autoclose)
5271 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5272 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
5273
5274 /* and enter the SHUTDOWN-SENT state. */
5275 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5276 SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT));
5277
5278 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5279 *
5280 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
d808ad9a 5281 * or SHUTDOWN-ACK.
1da177e4
LT
5282 */
5283 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
5284
5285 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5286
5287 return SCTP_DISPOSITION_CONSUME;
5288
5289nomem:
5290 return SCTP_DISPOSITION_NOMEM;
5291}
5292
5293/*
5294 * Generate a SHUTDOWN ACK now that everything is SACK'd.
5295 *
5296 * From Section 9.2:
5297 *
5298 * If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5299 * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own,
5300 * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the
5301 * endpoint must re-send the SHUTDOWN ACK.
5302 *
5303 * The return value is the disposition.
5304 */
5305sctp_disposition_t sctp_sf_do_9_2_shutdown_ack(
24cb81a6 5306 struct net *net,
1da177e4
LT
5307 const struct sctp_endpoint *ep,
5308 const struct sctp_association *asoc,
5309 const sctp_subtype_t type,
5310 void *arg,
5311 sctp_cmd_seq_t *commands)
5312{
5313 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
5314 struct sctp_chunk *reply;
5315
5316 /* There are 2 ways of getting here:
5317 * 1) called in response to a SHUTDOWN chunk
5318 * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued.
5319 *
5320 * For the case (2), the arg parameter is set to NULL. We need
5321 * to check that we have a chunk before accessing it's fields.
5322 */
5323 if (chunk) {
5324 if (!sctp_vtag_verify(chunk, asoc))
24cb81a6 5325 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
5326
5327 /* Make sure that the SHUTDOWN chunk has a valid length. */
5328 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_shutdown_chunk_t)))
24cb81a6 5329 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4
LT
5330 commands);
5331 }
5332
5333 /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5334 * shall send a SHUTDOWN ACK ...
5335 */
5336 reply = sctp_make_shutdown_ack(asoc, chunk);
5337 if (!reply)
5338 goto nomem;
5339
5340 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
5341 * the T2-shutdown timer.
5342 */
5343 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5344
5345 /* and start/restart a T2-shutdown timer of its own, */
5346 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5347 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5348
5349 if (asoc->autoclose)
5350 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5351 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
5352
5353 /* Enter the SHUTDOWN-ACK-SENT state. */
5354 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5355 SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT));
5356
5357 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5358 *
5359 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
d808ad9a 5360 * or SHUTDOWN-ACK.
1da177e4
LT
5361 */
5362 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
5363
5364 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5365
5366 return SCTP_DISPOSITION_CONSUME;
5367
5368nomem:
5369 return SCTP_DISPOSITION_NOMEM;
5370}
5371
5372/*
5373 * Ignore the event defined as other
5374 *
5375 * The return value is the disposition of the event.
5376 */
24cb81a6
EB
5377sctp_disposition_t sctp_sf_ignore_other(struct net *net,
5378 const struct sctp_endpoint *ep,
1da177e4
LT
5379 const struct sctp_association *asoc,
5380 const sctp_subtype_t type,
5381 void *arg,
5382 sctp_cmd_seq_t *commands)
5383{
bb33381d
DB
5384 pr_debug("%s: the event other type:%d is ignored\n",
5385 __func__, type.other);
5386
1da177e4
LT
5387 return SCTP_DISPOSITION_DISCARD;
5388}
5389
5390/************************************************************
5391 * These are the state functions for handling timeout events.
5392 ************************************************************/
5393
5394/*
5395 * RTX Timeout
5396 *
5397 * Section: 6.3.3 Handle T3-rtx Expiration
5398 *
5399 * Whenever the retransmission timer T3-rtx expires for a destination
5400 * address, do the following:
5401 * [See below]
5402 *
5403 * The return value is the disposition of the chunk.
5404 */
24cb81a6
EB
5405sctp_disposition_t sctp_sf_do_6_3_3_rtx(struct net *net,
5406 const struct sctp_endpoint *ep,
1da177e4
LT
5407 const struct sctp_association *asoc,
5408 const sctp_subtype_t type,
5409 void *arg,
5410 sctp_cmd_seq_t *commands)
5411{
5412 struct sctp_transport *transport = arg;
5413
b01a2407 5414 SCTP_INC_STATS(net, SCTP_MIB_T3_RTX_EXPIREDS);
ac0b0462 5415
1da177e4 5416 if (asoc->overall_error_count >= asoc->max_retrans) {
f8d96052
TG
5417 if (asoc->state == SCTP_STATE_SHUTDOWN_PENDING) {
5418 /*
5419 * We are here likely because the receiver had its rwnd
5420 * closed for a while and we have not been able to
5421 * transmit the locally queued data within the maximum
5422 * retransmission attempts limit. Start the T5
5423 * shutdown guard timer to give the receiver one last
5424 * chance and some additional time to recover before
5425 * aborting.
5426 */
5427 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START_ONCE,
5428 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5429 } else {
5430 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5431 SCTP_ERROR(ETIMEDOUT));
5432 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5433 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5434 SCTP_PERR(SCTP_ERROR_NO_ERROR));
b01a2407
EB
5435 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5436 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
f8d96052
TG
5437 return SCTP_DISPOSITION_DELETE_TCB;
5438 }
1da177e4
LT
5439 }
5440
5441 /* E1) For the destination address for which the timer
5442 * expires, adjust its ssthresh with rules defined in Section
5443 * 7.2.3 and set the cwnd <- MTU.
5444 */
5445
5446 /* E2) For the destination address for which the timer
5447 * expires, set RTO <- RTO * 2 ("back off the timer"). The
5448 * maximum value discussed in rule C7 above (RTO.max) may be
5449 * used to provide an upper bound to this doubling operation.
5450 */
5451
5452 /* E3) Determine how many of the earliest (i.e., lowest TSN)
5453 * outstanding DATA chunks for the address for which the
5454 * T3-rtx has expired will fit into a single packet, subject
5455 * to the MTU constraint for the path corresponding to the
5456 * destination transport address to which the retransmission
5457 * is being sent (this may be different from the address for
5458 * which the timer expires [see Section 6.4]). Call this
5459 * value K. Bundle and retransmit those K DATA chunks in a
5460 * single packet to the destination endpoint.
5461 *
5462 * Note: Any DATA chunks that were sent to the address for
5463 * which the T3-rtx timer expired but did not fit in one MTU
5464 * (rule E3 above), should be marked for retransmission and
5465 * sent as soon as cwnd allows (normally when a SACK arrives).
5466 */
5467
1da177e4
LT
5468 /* Do some failure management (Section 8.2). */
5469 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
5470
1845a579
VY
5471 /* NB: Rules E4 and F1 are implicit in R1. */
5472 sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN, SCTP_TRANSPORT(transport));
5473
1da177e4
LT
5474 return SCTP_DISPOSITION_CONSUME;
5475}
5476
5477/*
5478 * Generate delayed SACK on timeout
5479 *
5480 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
5481 *
5482 * The guidelines on delayed acknowledgement algorithm specified in
5483 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
5484 * acknowledgement SHOULD be generated for at least every second packet
5485 * (not every second DATA chunk) received, and SHOULD be generated
5486 * within 200 ms of the arrival of any unacknowledged DATA chunk. In
5487 * some situations it may be beneficial for an SCTP transmitter to be
5488 * more conservative than the algorithms detailed in this document
5489 * allow. However, an SCTP transmitter MUST NOT be more aggressive than
5490 * the following algorithms allow.
5491 */
24cb81a6
EB
5492sctp_disposition_t sctp_sf_do_6_2_sack(struct net *net,
5493 const struct sctp_endpoint *ep,
1da177e4
LT
5494 const struct sctp_association *asoc,
5495 const sctp_subtype_t type,
5496 void *arg,
5497 sctp_cmd_seq_t *commands)
5498{
b01a2407 5499 SCTP_INC_STATS(net, SCTP_MIB_DELAY_SACK_EXPIREDS);
1da177e4
LT
5500 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
5501 return SCTP_DISPOSITION_CONSUME;
5502}
5503
5504/*
3f7a87d2 5505 * sctp_sf_t1_init_timer_expire
1da177e4
LT
5506 *
5507 * Section: 4 Note: 2
5508 * Verification Tag:
5509 * Inputs
5510 * (endpoint, asoc)
5511 *
5512 * RFC 2960 Section 4 Notes
5513 * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT
5514 * and re-start the T1-init timer without changing state. This MUST
5515 * be repeated up to 'Max.Init.Retransmits' times. After that, the
5516 * endpoint MUST abort the initialization process and report the
5517 * error to SCTP user.
5518 *
3f7a87d2
FF
5519 * Outputs
5520 * (timers, events)
5521 *
5522 */
24cb81a6
EB
5523sctp_disposition_t sctp_sf_t1_init_timer_expire(struct net *net,
5524 const struct sctp_endpoint *ep,
3f7a87d2
FF
5525 const struct sctp_association *asoc,
5526 const sctp_subtype_t type,
5527 void *arg,
5528 sctp_cmd_seq_t *commands)
5529{
5530 struct sctp_chunk *repl = NULL;
5531 struct sctp_bind_addr *bp;
5532 int attempts = asoc->init_err_counter + 1;
5533
bb33381d
DB
5534 pr_debug("%s: timer T1 expired (INIT)\n", __func__);
5535
b01a2407 5536 SCTP_INC_STATS(net, SCTP_MIB_T1_INIT_EXPIREDS);
3f7a87d2 5537
81845c21 5538 if (attempts <= asoc->max_init_attempts) {
3f7a87d2
FF
5539 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
5540 repl = sctp_make_init(asoc, bp, GFP_ATOMIC, 0);
5541 if (!repl)
5542 return SCTP_DISPOSITION_NOMEM;
5543
5544 /* Choose transport for INIT. */
5545 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
5546 SCTP_CHUNK(repl));
5547
5548 /* Issue a sideeffect to do the needed accounting. */
5549 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_RESTART,
5550 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
5551
5552 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
5553 } else {
bb33381d
DB
5554 pr_debug("%s: giving up on INIT, attempts:%d "
5555 "max_init_attempts:%d\n", __func__, attempts,
5556 asoc->max_init_attempts);
5557
8de8c873
SS
5558 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5559 SCTP_ERROR(ETIMEDOUT));
3f7a87d2 5560 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
dc251b2b 5561 SCTP_PERR(SCTP_ERROR_NO_ERROR));
3f7a87d2
FF
5562 return SCTP_DISPOSITION_DELETE_TCB;
5563 }
5564
5565 return SCTP_DISPOSITION_CONSUME;
5566}
5567
5568/*
5569 * sctp_sf_t1_cookie_timer_expire
5570 *
5571 * Section: 4 Note: 2
5572 * Verification Tag:
5573 * Inputs
5574 * (endpoint, asoc)
5575 *
5576 * RFC 2960 Section 4 Notes
5577 * 3) If the T1-cookie timer expires, the endpoint MUST retransmit
1da177e4
LT
5578 * COOKIE ECHO and re-start the T1-cookie timer without changing
5579 * state. This MUST be repeated up to 'Max.Init.Retransmits' times.
5580 * After that, the endpoint MUST abort the initialization process and
5581 * report the error to SCTP user.
5582 *
5583 * Outputs
5584 * (timers, events)
5585 *
5586 */
24cb81a6
EB
5587sctp_disposition_t sctp_sf_t1_cookie_timer_expire(struct net *net,
5588 const struct sctp_endpoint *ep,
1da177e4
LT
5589 const struct sctp_association *asoc,
5590 const sctp_subtype_t type,
5591 void *arg,
5592 sctp_cmd_seq_t *commands)
5593{
3f7a87d2
FF
5594 struct sctp_chunk *repl = NULL;
5595 int attempts = asoc->init_err_counter + 1;
1da177e4 5596
bb33381d
DB
5597 pr_debug("%s: timer T1 expired (COOKIE-ECHO)\n", __func__);
5598
b01a2407 5599 SCTP_INC_STATS(net, SCTP_MIB_T1_COOKIE_EXPIREDS);
1da177e4 5600
81845c21 5601 if (attempts <= asoc->max_init_attempts) {
3f7a87d2 5602 repl = sctp_make_cookie_echo(asoc, NULL);
1da177e4 5603 if (!repl)
3f7a87d2 5604 return SCTP_DISPOSITION_NOMEM;
1da177e4 5605
96cd0d3d
VY
5606 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
5607 SCTP_CHUNK(repl));
1da177e4 5608 /* Issue a sideeffect to do the needed accounting. */
3f7a87d2
FF
5609 sctp_add_cmd_sf(commands, SCTP_CMD_COOKIEECHO_RESTART,
5610 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
5611
1da177e4
LT
5612 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
5613 } else {
8de8c873
SS
5614 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5615 SCTP_ERROR(ETIMEDOUT));
1da177e4 5616 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
dc251b2b 5617 SCTP_PERR(SCTP_ERROR_NO_ERROR));
1da177e4
LT
5618 return SCTP_DISPOSITION_DELETE_TCB;
5619 }
5620
5621 return SCTP_DISPOSITION_CONSUME;
1da177e4
LT
5622}
5623
5624/* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN
5625 * with the updated last sequential TSN received from its peer.
5626 *
5627 * An endpoint should limit the number of retransmissions of the
5628 * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'.
5629 * If this threshold is exceeded the endpoint should destroy the TCB and
5630 * MUST report the peer endpoint unreachable to the upper layer (and
5631 * thus the association enters the CLOSED state). The reception of any
5632 * packet from its peer (i.e. as the peer sends all of its queued DATA
5633 * chunks) should clear the endpoint's retransmission count and restart
5634 * the T2-Shutdown timer, giving its peer ample opportunity to transmit
5635 * all of its queued DATA chunks that have not yet been sent.
5636 */
24cb81a6
EB
5637sctp_disposition_t sctp_sf_t2_timer_expire(struct net *net,
5638 const struct sctp_endpoint *ep,
1da177e4
LT
5639 const struct sctp_association *asoc,
5640 const sctp_subtype_t type,
5641 void *arg,
5642 sctp_cmd_seq_t *commands)
5643{
5644 struct sctp_chunk *reply = NULL;
5645
bb33381d
DB
5646 pr_debug("%s: timer T2 expired\n", __func__);
5647
b01a2407 5648 SCTP_INC_STATS(net, SCTP_MIB_T2_SHUTDOWN_EXPIREDS);
ac0b0462 5649
58fbbed4
NH
5650 ((struct sctp_association *)asoc)->shutdown_retries++;
5651
1da177e4 5652 if (asoc->overall_error_count >= asoc->max_retrans) {
8de8c873
SS
5653 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5654 SCTP_ERROR(ETIMEDOUT));
1da177e4
LT
5655 /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5656 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5be291fe 5657 SCTP_PERR(SCTP_ERROR_NO_ERROR));
b01a2407
EB
5658 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5659 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
1da177e4
LT
5660 return SCTP_DISPOSITION_DELETE_TCB;
5661 }
5662
5663 switch (asoc->state) {
5664 case SCTP_STATE_SHUTDOWN_SENT:
5665 reply = sctp_make_shutdown(asoc, NULL);
5666 break;
5667
5668 case SCTP_STATE_SHUTDOWN_ACK_SENT:
5669 reply = sctp_make_shutdown_ack(asoc, NULL);
5670 break;
5671
5672 default:
5673 BUG();
5674 break;
3ff50b79 5675 }
1da177e4
LT
5676
5677 if (!reply)
5678 goto nomem;
5679
6345b199
WY
5680 /* Do some failure management (Section 8.2).
5681 * If we remove the transport an SHUTDOWN was last sent to, don't
5682 * do failure management.
5683 */
5684 if (asoc->shutdown_last_sent_to)
5685 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
5686 SCTP_TRANSPORT(asoc->shutdown_last_sent_to));
1da177e4
LT
5687
5688 /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for
5689 * the T2-shutdown timer.
5690 */
5691 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5692
5693 /* Restart the T2-shutdown timer. */
5694 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5695 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5696 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5697 return SCTP_DISPOSITION_CONSUME;
5698
5699nomem:
5700 return SCTP_DISPOSITION_NOMEM;
5701}
5702
5703/*
5704 * ADDIP Section 4.1 ASCONF CHunk Procedures
5705 * If the T4 RTO timer expires the endpoint should do B1 to B5
5706 */
5707sctp_disposition_t sctp_sf_t4_timer_expire(
24cb81a6 5708 struct net *net,
1da177e4
LT
5709 const struct sctp_endpoint *ep,
5710 const struct sctp_association *asoc,
5711 const sctp_subtype_t type,
5712 void *arg,
5713 sctp_cmd_seq_t *commands)
5714{
5715 struct sctp_chunk *chunk = asoc->addip_last_asconf;
5716 struct sctp_transport *transport = chunk->transport;
5717
b01a2407 5718 SCTP_INC_STATS(net, SCTP_MIB_T4_RTO_EXPIREDS);
ac0b0462 5719
1da177e4
LT
5720 /* ADDIP 4.1 B1) Increment the error counters and perform path failure
5721 * detection on the appropriate destination address as defined in
5722 * RFC2960 [5] section 8.1 and 8.2.
5723 */
10a43cea
WY
5724 if (transport)
5725 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
5726 SCTP_TRANSPORT(transport));
1da177e4
LT
5727
5728 /* Reconfig T4 timer and transport. */
5729 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
5730
5731 /* ADDIP 4.1 B2) Increment the association error counters and perform
5732 * endpoint failure detection on the association as defined in
5733 * RFC2960 [5] section 8.1 and 8.2.
5734 * association error counter is incremented in SCTP_CMD_STRIKE.
5735 */
5736 if (asoc->overall_error_count >= asoc->max_retrans) {
5737 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5738 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
8de8c873
SS
5739 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5740 SCTP_ERROR(ETIMEDOUT));
1da177e4 5741 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5be291fe 5742 SCTP_PERR(SCTP_ERROR_NO_ERROR));
b01a2407
EB
5743 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5744 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
1da177e4
LT
5745 return SCTP_DISPOSITION_ABORT;
5746 }
5747
5748 /* ADDIP 4.1 B3) Back-off the destination address RTO value to which
5749 * the ASCONF chunk was sent by doubling the RTO timer value.
5750 * This is done in SCTP_CMD_STRIKE.
5751 */
5752
5753 /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible
5754 * choose an alternate destination address (please refer to RFC2960
5755 * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this
d808ad9a 5756 * chunk, it MUST be the same (including its serial number) as the last
1da177e4
LT
5757 * ASCONF sent.
5758 */
5759 sctp_chunk_hold(asoc->addip_last_asconf);
5760 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
5761 SCTP_CHUNK(asoc->addip_last_asconf));
5762
5763 /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different
5764 * destination is selected, then the RTO used will be that of the new
5765 * destination address.
5766 */
5767 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5768 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
5769
5770 return SCTP_DISPOSITION_CONSUME;
5771}
5772
5773/* sctpimpguide-05 Section 2.12.2
5774 * The sender of the SHUTDOWN MAY also start an overall guard timer
5775 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5776 * At the expiration of this timer the sender SHOULD abort the association
5777 * by sending an ABORT chunk.
5778 */
24cb81a6
EB
5779sctp_disposition_t sctp_sf_t5_timer_expire(struct net *net,
5780 const struct sctp_endpoint *ep,
1da177e4
LT
5781 const struct sctp_association *asoc,
5782 const sctp_subtype_t type,
5783 void *arg,
5784 sctp_cmd_seq_t *commands)
5785{
5786 struct sctp_chunk *reply = NULL;
5787
bb33381d
DB
5788 pr_debug("%s: timer T5 expired\n", __func__);
5789
b01a2407 5790 SCTP_INC_STATS(net, SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS);
1da177e4
LT
5791
5792 reply = sctp_make_abort(asoc, NULL, 0);
5793 if (!reply)
5794 goto nomem;
5795
5796 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
8de8c873
SS
5797 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5798 SCTP_ERROR(ETIMEDOUT));
1da177e4 5799 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5be291fe 5800 SCTP_PERR(SCTP_ERROR_NO_ERROR));
1da177e4 5801
b01a2407
EB
5802 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5803 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
a1080a8b 5804
1da177e4
LT
5805 return SCTP_DISPOSITION_DELETE_TCB;
5806nomem:
5807 return SCTP_DISPOSITION_NOMEM;
5808}
5809
5810/* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires,
5811 * the association is automatically closed by starting the shutdown process.
5812 * The work that needs to be done is same as when SHUTDOWN is initiated by
5813 * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown().
5814 */
5815sctp_disposition_t sctp_sf_autoclose_timer_expire(
24cb81a6 5816 struct net *net,
1da177e4
LT
5817 const struct sctp_endpoint *ep,
5818 const struct sctp_association *asoc,
5819 const sctp_subtype_t type,
5820 void *arg,
5821 sctp_cmd_seq_t *commands)
5822{
5823 int disposition;
5824
b01a2407 5825 SCTP_INC_STATS(net, SCTP_MIB_AUTOCLOSE_EXPIREDS);
ac0b0462 5826
1da177e4
LT
5827 /* From 9.2 Shutdown of an Association
5828 * Upon receipt of the SHUTDOWN primitive from its upper
5829 * layer, the endpoint enters SHUTDOWN-PENDING state and
5830 * remains there until all outstanding data has been
5831 * acknowledged by its peer. The endpoint accepts no new data
5832 * from its upper layer, but retransmits data to the far end
5833 * if necessary to fill gaps.
5834 */
5835 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5836 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
5837
1da177e4
LT
5838 disposition = SCTP_DISPOSITION_CONSUME;
5839 if (sctp_outq_is_empty(&asoc->outqueue)) {
24cb81a6 5840 disposition = sctp_sf_do_9_2_start_shutdown(net, ep, asoc, type,
1da177e4
LT
5841 arg, commands);
5842 }
5843 return disposition;
5844}
5845
5846/*****************************************************************************
5847 * These are sa state functions which could apply to all types of events.
5848 ****************************************************************************/
5849
5850/*
5851 * This table entry is not implemented.
5852 *
5853 * Inputs
5854 * (endpoint, asoc, chunk)
5855 *
5856 * The return value is the disposition of the chunk.
5857 */
24cb81a6
EB
5858sctp_disposition_t sctp_sf_not_impl(struct net *net,
5859 const struct sctp_endpoint *ep,
1da177e4
LT
5860 const struct sctp_association *asoc,
5861 const sctp_subtype_t type,
5862 void *arg,
5863 sctp_cmd_seq_t *commands)
5864{
5865 return SCTP_DISPOSITION_NOT_IMPL;
5866}
5867
5868/*
5869 * This table entry represents a bug.
5870 *
5871 * Inputs
5872 * (endpoint, asoc, chunk)
5873 *
5874 * The return value is the disposition of the chunk.
5875 */
24cb81a6
EB
5876sctp_disposition_t sctp_sf_bug(struct net *net,
5877 const struct sctp_endpoint *ep,
1da177e4
LT
5878 const struct sctp_association *asoc,
5879 const sctp_subtype_t type,
5880 void *arg,
5881 sctp_cmd_seq_t *commands)
5882{
5883 return SCTP_DISPOSITION_BUG;
5884}
5885
5886/*
5887 * This table entry represents the firing of a timer in the wrong state.
5888 * Since timer deletion cannot be guaranteed a timer 'may' end up firing
5889 * when the association is in the wrong state. This event should
5890 * be ignored, so as to prevent any rearming of the timer.
5891 *
5892 * Inputs
5893 * (endpoint, asoc, chunk)
5894 *
5895 * The return value is the disposition of the chunk.
5896 */
24cb81a6
EB
5897sctp_disposition_t sctp_sf_timer_ignore(struct net *net,
5898 const struct sctp_endpoint *ep,
1da177e4
LT
5899 const struct sctp_association *asoc,
5900 const sctp_subtype_t type,
5901 void *arg,
5902 sctp_cmd_seq_t *commands)
5903{
bb33381d
DB
5904 pr_debug("%s: timer %d ignored\n", __func__, type.chunk);
5905
1da177e4
LT
5906 return SCTP_DISPOSITION_CONSUME;
5907}
5908
5909/********************************************************************
5910 * 2nd Level Abstractions
5911 ********************************************************************/
5912
5913/* Pull the SACK chunk based on the SACK header. */
5914static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk)
5915{
5916 struct sctp_sackhdr *sack;
5917 unsigned int len;
5918 __u16 num_blocks;
5919 __u16 num_dup_tsns;
5920
5921 /* Protect ourselves from reading too far into
5922 * the skb from a bogus sender.
5923 */
5924 sack = (struct sctp_sackhdr *) chunk->skb->data;
5925
5926 num_blocks = ntohs(sack->num_gap_ack_blocks);
5927 num_dup_tsns = ntohs(sack->num_dup_tsns);
5928 len = sizeof(struct sctp_sackhdr);
5929 len += (num_blocks + num_dup_tsns) * sizeof(__u32);
5930 if (len > chunk->skb->len)
5931 return NULL;
5932
5933 skb_pull(chunk->skb, len);
5934
5935 return sack;
5936}
5937
5938/* Create an ABORT packet to be sent as a response, with the specified
5939 * error causes.
5940 */
24cb81a6
EB
5941static struct sctp_packet *sctp_abort_pkt_new(struct net *net,
5942 const struct sctp_endpoint *ep,
1da177e4
LT
5943 const struct sctp_association *asoc,
5944 struct sctp_chunk *chunk,
5945 const void *payload,
5946 size_t paylen)
5947{
5948 struct sctp_packet *packet;
5949 struct sctp_chunk *abort;
5950
2ce95503 5951 packet = sctp_ootb_pkt_new(net, asoc, chunk);
1da177e4
LT
5952
5953 if (packet) {
5954 /* Make an ABORT.
5955 * The T bit will be set if the asoc is NULL.
5956 */
5957 abort = sctp_make_abort(asoc, chunk, paylen);
5958 if (!abort) {
5959 sctp_ootb_pkt_free(packet);
5960 return NULL;
5961 }
047a2428
JF
5962
5963 /* Reflect vtag if T-Bit is set */
5964 if (sctp_test_T_bit(abort))
5965 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
5966
1da177e4
LT
5967 /* Add specified error causes, i.e., payload, to the
5968 * end of the chunk.
5969 */
5970 sctp_addto_chunk(abort, paylen, payload);
5971
5972 /* Set the skb to the belonging sock for accounting. */
5973 abort->skb->sk = ep->base.sk;
5974
5975 sctp_packet_append_chunk(packet, abort);
5976
5977 }
5978
5979 return packet;
5980}
5981
5982/* Allocate a packet for responding in the OOTB conditions. */
2ce95503
EB
5983static struct sctp_packet *sctp_ootb_pkt_new(struct net *net,
5984 const struct sctp_association *asoc,
1da177e4
LT
5985 const struct sctp_chunk *chunk)
5986{
5987 struct sctp_packet *packet;
5988 struct sctp_transport *transport;
5989 __u16 sport;
5990 __u16 dport;
5991 __u32 vtag;
5992
5993 /* Get the source and destination port from the inbound packet. */
5994 sport = ntohs(chunk->sctp_hdr->dest);
5995 dport = ntohs(chunk->sctp_hdr->source);
5996
5997 /* The V-tag is going to be the same as the inbound packet if no
5998 * association exists, otherwise, use the peer's vtag.
5999 */
6000 if (asoc) {
02c4e12c
WY
6001 /* Special case the INIT-ACK as there is no peer's vtag
6002 * yet.
6003 */
6004 switch(chunk->chunk_hdr->type) {
6005 case SCTP_CID_INIT_ACK:
6006 {
6007 sctp_initack_chunk_t *initack;
6008
6009 initack = (sctp_initack_chunk_t *)chunk->chunk_hdr;
6010 vtag = ntohl(initack->init_hdr.init_tag);
6011 break;
6012 }
6013 default:
6014 vtag = asoc->peer.i.init_tag;
6015 break;
6016 }
1da177e4
LT
6017 } else {
6018 /* Special case the INIT and stale COOKIE_ECHO as there is no
6019 * vtag yet.
6020 */
6021 switch(chunk->chunk_hdr->type) {
6022 case SCTP_CID_INIT:
6023 {
6024 sctp_init_chunk_t *init;
6025
6026 init = (sctp_init_chunk_t *)chunk->chunk_hdr;
6027 vtag = ntohl(init->init_hdr.init_tag);
6028 break;
6029 }
d808ad9a 6030 default:
1da177e4
LT
6031 vtag = ntohl(chunk->sctp_hdr->vtag);
6032 break;
6033 }
6034 }
6035
6036 /* Make a transport for the bucket, Eliza... */
89bf3450 6037 transport = sctp_transport_new(net, sctp_source(chunk), GFP_ATOMIC);
1da177e4
LT
6038 if (!transport)
6039 goto nomem;
6040
6041 /* Cache a route for the transport with the chunk's destination as
6042 * the source address.
6043 */
16b0a030 6044 sctp_transport_route(transport, (union sctp_addr *)&chunk->dest,
2ce95503 6045 sctp_sk(net->sctp.ctl_sock));
1da177e4
LT
6046
6047 packet = sctp_packet_init(&transport->packet, transport, sport, dport);
6048 packet = sctp_packet_config(packet, vtag, 0);
6049
6050 return packet;
6051
6052nomem:
6053 return NULL;
6054}
6055
6056/* Free the packet allocated earlier for responding in the OOTB condition. */
6057void sctp_ootb_pkt_free(struct sctp_packet *packet)
6058{
6059 sctp_transport_free(packet->transport);
6060}
6061
6062/* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */
24cb81a6
EB
6063static void sctp_send_stale_cookie_err(struct net *net,
6064 const struct sctp_endpoint *ep,
1da177e4
LT
6065 const struct sctp_association *asoc,
6066 const struct sctp_chunk *chunk,
6067 sctp_cmd_seq_t *commands,
6068 struct sctp_chunk *err_chunk)
6069{
6070 struct sctp_packet *packet;
6071
6072 if (err_chunk) {
2ce95503 6073 packet = sctp_ootb_pkt_new(net, asoc, chunk);
1da177e4
LT
6074 if (packet) {
6075 struct sctp_signed_cookie *cookie;
6076
6077 /* Override the OOTB vtag from the cookie. */
6078 cookie = chunk->subh.cookie_hdr;
6079 packet->vtag = cookie->c.peer_vtag;
d808ad9a 6080
1da177e4
LT
6081 /* Set the skb to the belonging sock for accounting. */
6082 err_chunk->skb->sk = ep->base.sk;
6083 sctp_packet_append_chunk(packet, err_chunk);
6084 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
6085 SCTP_PACKET(packet));
b01a2407 6086 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
1da177e4
LT
6087 } else
6088 sctp_chunk_free (err_chunk);
6089 }
6090}
6091
6092
6093/* Process a data chunk */
6094static int sctp_eat_data(const struct sctp_association *asoc,
6095 struct sctp_chunk *chunk,
6096 sctp_cmd_seq_t *commands)
6097{
6098 sctp_datahdr_t *data_hdr;
6099 struct sctp_chunk *err;
6100 size_t datalen;
6101 sctp_verb_t deliver;
6102 int tmp;
6103 __u32 tsn;
7c3ceb4f 6104 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
049b3ff5 6105 struct sock *sk = asoc->base.sk;
24cb81a6 6106 struct net *net = sock_net(sk);
f1751c57
VY
6107 u16 ssn;
6108 u16 sid;
6109 u8 ordered = 0;
1da177e4
LT
6110
6111 data_hdr = chunk->subh.data_hdr = (sctp_datahdr_t *)chunk->skb->data;
6112 skb_pull(chunk->skb, sizeof(sctp_datahdr_t));
6113
6114 tsn = ntohl(data_hdr->tsn);
bb33381d 6115 pr_debug("%s: TSN 0x%x\n", __func__, tsn);
1da177e4
LT
6116
6117 /* ASSERT: Now skb->data is really the user data. */
6118
6119 /* Process ECN based congestion.
6120 *
6121 * Since the chunk structure is reused for all chunks within
6122 * a packet, we use ecn_ce_done to track if we've already
6123 * done CE processing for this packet.
6124 *
6125 * We need to do ECN processing even if we plan to discard the
6126 * chunk later.
6127 */
6128
6129 if (!chunk->ecn_ce_done) {
6130 struct sctp_af *af;
6131 chunk->ecn_ce_done = 1;
6132
6133 af = sctp_get_af_specific(
eddc9ec5 6134 ipver2af(ip_hdr(chunk->skb)->version));
1da177e4
LT
6135
6136 if (af && af->is_ce(chunk->skb) && asoc->peer.ecn_capable) {
6137 /* Do real work as sideffect. */
6138 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_CE,
6139 SCTP_U32(tsn));
6140 }
6141 }
6142
6143 tmp = sctp_tsnmap_check(&asoc->peer.tsn_map, tsn);
6144 if (tmp < 0) {
6145 /* The TSN is too high--silently discard the chunk and
6146 * count on it getting retransmitted later.
6147 */
196d6759
MB
6148 if (chunk->asoc)
6149 chunk->asoc->stats.outofseqtsns++;
1da177e4
LT
6150 return SCTP_IERROR_HIGH_TSN;
6151 } else if (tmp > 0) {
6152 /* This is a duplicate. Record it. */
6153 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_DUP, SCTP_U32(tsn));
6154 return SCTP_IERROR_DUP_TSN;
6155 }
6156
6157 /* This is a new TSN. */
6158
6159 /* Discard if there is no room in the receive window.
6160 * Actually, allow a little bit of overflow (up to a MTU).
6161 */
6162 datalen = ntohs(chunk->chunk_hdr->length);
6163 datalen -= sizeof(sctp_data_chunk_t);
6164
6165 deliver = SCTP_CMD_CHUNK_ULP;
6166
6167 /* Think about partial delivery. */
6168 if ((datalen >= asoc->rwnd) && (!asoc->ulpq.pd_mode)) {
6169
6170 /* Even if we don't accept this chunk there is
6171 * memory pressure.
6172 */
6173 sctp_add_cmd_sf(commands, SCTP_CMD_PART_DELIVER, SCTP_NULL());
6174 }
6175
d808ad9a 6176 /* Spill over rwnd a little bit. Note: While allowed, this spill over
1da177e4
LT
6177 * seems a bit troublesome in that frag_point varies based on
6178 * PMTU. In cases, such as loopback, this might be a rather
6179 * large spill over.
4d93df0a
NH
6180 */
6181 if ((!chunk->data_accepted) && (!asoc->rwnd || asoc->rwnd_over ||
6182 (datalen > asoc->rwnd + asoc->frag_point))) {
1da177e4
LT
6183
6184 /* If this is the next TSN, consider reneging to make
6185 * room. Note: Playing nice with a confused sender. A
6186 * malicious sender can still eat up all our buffer
6187 * space and in the future we may want to detect and
6188 * do more drastic reneging.
6189 */
7c3ceb4f
NH
6190 if (sctp_tsnmap_has_gap(map) &&
6191 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
bb33381d 6192 pr_debug("%s: reneging for tsn:%u\n", __func__, tsn);
1da177e4
LT
6193 deliver = SCTP_CMD_RENEGE;
6194 } else {
bb33381d
DB
6195 pr_debug("%s: discard tsn:%u len:%zu, rwnd:%d\n",
6196 __func__, tsn, datalen, asoc->rwnd);
6197
1da177e4
LT
6198 return SCTP_IERROR_IGNORE_TSN;
6199 }
6200 }
6201
4d93df0a
NH
6202 /*
6203 * Also try to renege to limit our memory usage in the event that
6204 * we are under memory pressure
3ab224be 6205 * If we can't renege, don't worry about it, the sk_rmem_schedule
4d93df0a
NH
6206 * in sctp_ulpevent_make_rcvmsg will drop the frame if we grow our
6207 * memory usage too much
6208 */
6209 if (*sk->sk_prot_creator->memory_pressure) {
6210 if (sctp_tsnmap_has_gap(map) &&
6211 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
bb33381d
DB
6212 pr_debug("%s: under pressure, reneging for tsn:%u\n",
6213 __func__, tsn);
4d93df0a
NH
6214 deliver = SCTP_CMD_RENEGE;
6215 }
6216 }
6217
1da177e4
LT
6218 /*
6219 * Section 3.3.10.9 No User Data (9)
6220 *
6221 * Cause of error
6222 * ---------------
6223 * No User Data: This error cause is returned to the originator of a
6224 * DATA chunk if a received DATA chunk has no user data.
6225 */
6226 if (unlikely(0 == datalen)) {
6227 err = sctp_make_abort_no_data(asoc, chunk, tsn);
6228 if (err) {
6229 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
6230 SCTP_CHUNK(err));
6231 }
6232 /* We are going to ABORT, so we might as well stop
6233 * processing the rest of the chunks in the packet.
6234 */
6235 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
8de8c873
SS
6236 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
6237 SCTP_ERROR(ECONNABORTED));
1da177e4 6238 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5be291fe 6239 SCTP_PERR(SCTP_ERROR_NO_DATA));
b01a2407
EB
6240 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
6241 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
1da177e4
LT
6242 return SCTP_IERROR_NO_DATA;
6243 }
6244
9faa730f
SS
6245 chunk->data_accepted = 1;
6246
1da177e4
LT
6247 /* Note: Some chunks may get overcounted (if we drop) or overcounted
6248 * if we renege and the chunk arrives again.
6249 */
196d6759 6250 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
b01a2407 6251 SCTP_INC_STATS(net, SCTP_MIB_INUNORDERCHUNKS);
196d6759
MB
6252 if (chunk->asoc)
6253 chunk->asoc->stats.iuodchunks++;
6254 } else {
b01a2407 6255 SCTP_INC_STATS(net, SCTP_MIB_INORDERCHUNKS);
196d6759
MB
6256 if (chunk->asoc)
6257 chunk->asoc->stats.iodchunks++;
f1751c57
VY
6258 ordered = 1;
6259 }
1da177e4
LT
6260
6261 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
6262 *
6263 * If an endpoint receive a DATA chunk with an invalid stream
6264 * identifier, it shall acknowledge the reception of the DATA chunk
6265 * following the normal procedure, immediately send an ERROR chunk
6266 * with cause set to "Invalid Stream Identifier" (See Section 3.3.10)
6267 * and discard the DATA chunk.
6268 */
f1751c57
VY
6269 sid = ntohs(data_hdr->stream);
6270 if (sid >= asoc->c.sinit_max_instreams) {
3888e9ef
VY
6271 /* Mark tsn as received even though we drop it */
6272 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_TSN, SCTP_U32(tsn));
6273
1da177e4
LT
6274 err = sctp_make_op_error(asoc, chunk, SCTP_ERROR_INV_STRM,
6275 &data_hdr->stream,
6383cfb3
VY
6276 sizeof(data_hdr->stream),
6277 sizeof(u16));
1da177e4
LT
6278 if (err)
6279 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
6280 SCTP_CHUNK(err));
6281 return SCTP_IERROR_BAD_STREAM;
6282 }
6283
f1751c57
VY
6284 /* Check to see if the SSN is possible for this TSN.
6285 * The biggest gap we can record is 4K wide. Since SSNs wrap
6286 * at an unsigned short, there is no way that an SSN can
6287 * wrap and for a valid TSN. We can simply check if the current
6288 * SSN is smaller then the next expected one. If it is, it wrapped
6289 * and is invalid.
6290 */
6291 ssn = ntohs(data_hdr->ssn);
6292 if (ordered && SSN_lt(ssn, sctp_ssn_peek(&asoc->ssnmap->in, sid))) {
6293 return SCTP_IERROR_PROTO_VIOLATION;
6294 }
6295
1da177e4
LT
6296 /* Send the data up to the user. Note: Schedule the
6297 * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK
6298 * chunk needs the updated rwnd.
6299 */
6300 sctp_add_cmd_sf(commands, deliver, SCTP_CHUNK(chunk));
6301
6302 return SCTP_IERROR_NO_ERROR;
6303}