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sctp: implement receiver-side procedures for the Add Incoming Streams Request Parameter
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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
4b2f13a2
JK
25 * along with GNU CC; see the file COPYING. If not, see
26 * <http://www.gnu.org/licenses/>.
1da177e4
LT
27 *
28 * Please send any bug reports or fixes you make to the
29 * email address(es):
91705c61 30 * lksctp developers <linux-sctp@vger.kernel.org>
1da177e4 31 *
1da177e4
LT
32 * Written or modified by:
33 * La Monte H.P. Yarroll <piggy@acm.org>
34 * Karl Knutson <karl@athena.chicago.il.us>
35 * Mathew Kotowsky <kotowsky@sctp.org>
36 * Sridhar Samudrala <samudrala@us.ibm.com>
37 * Jon Grimm <jgrimm@us.ibm.com>
38 * Hui Huang <hui.huang@nokia.com>
39 * Dajiang Zhang <dajiang.zhang@nokia.com>
40 * Daisy Chang <daisyc@us.ibm.com>
41 * Ardelle Fan <ardelle.fan@intel.com>
42 * Ryan Layer <rmlayer@us.ibm.com>
43 * Kevin Gao <kevin.gao@intel.com>
1da177e4
LT
44 */
45
145ce502
JP
46#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
47
1da177e4
LT
48#include <linux/types.h>
49#include <linux/kernel.h>
50#include <linux/ip.h>
51#include <linux/ipv6.h>
52#include <linux/net.h>
53#include <linux/inet.h>
5a0e3ad6 54#include <linux/slab.h>
1da177e4
LT
55#include <net/sock.h>
56#include <net/inet_ecn.h>
57#include <linux/skbuff.h>
58#include <net/sctp/sctp.h>
59#include <net/sctp/sm.h>
60#include <net/sctp/structs.h>
61
24cb81a6
EB
62static struct sctp_packet *sctp_abort_pkt_new(struct net *net,
63 const struct sctp_endpoint *ep,
1da177e4
LT
64 const struct sctp_association *asoc,
65 struct sctp_chunk *chunk,
66 const void *payload,
67 size_t paylen);
68static int sctp_eat_data(const struct sctp_association *asoc,
69 struct sctp_chunk *chunk,
70 sctp_cmd_seq_t *commands);
2ce95503
EB
71static struct sctp_packet *sctp_ootb_pkt_new(struct net *net,
72 const struct sctp_association *asoc,
1da177e4 73 const struct sctp_chunk *chunk);
24cb81a6
EB
74static void sctp_send_stale_cookie_err(struct net *net,
75 const struct sctp_endpoint *ep,
1da177e4
LT
76 const struct sctp_association *asoc,
77 const struct sctp_chunk *chunk,
78 sctp_cmd_seq_t *commands,
79 struct sctp_chunk *err_chunk);
24cb81a6
EB
80static sctp_disposition_t sctp_sf_do_5_2_6_stale(struct net *net,
81 const struct sctp_endpoint *ep,
1da177e4
LT
82 const struct sctp_association *asoc,
83 const sctp_subtype_t type,
84 void *arg,
85 sctp_cmd_seq_t *commands);
24cb81a6
EB
86static sctp_disposition_t sctp_sf_shut_8_4_5(struct net *net,
87 const struct sctp_endpoint *ep,
1da177e4
LT
88 const struct sctp_association *asoc,
89 const sctp_subtype_t type,
90 void *arg,
91 sctp_cmd_seq_t *commands);
24cb81a6
EB
92static sctp_disposition_t sctp_sf_tabort_8_4_8(struct net *net,
93 const struct sctp_endpoint *ep,
ece25dfa
VY
94 const struct sctp_association *asoc,
95 const sctp_subtype_t type,
96 void *arg,
97 sctp_cmd_seq_t *commands);
1da177e4
LT
98static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk);
99
24cb81a6
EB
100static sctp_disposition_t sctp_stop_t1_and_abort(struct net *net,
101 sctp_cmd_seq_t *commands,
f94c0198 102 __be16 error, int sk_err,
52c1da39
AB
103 const struct sctp_association *asoc,
104 struct sctp_transport *transport);
105
aecedeab 106static sctp_disposition_t sctp_sf_abort_violation(
24cb81a6 107 struct net *net,
ece25dfa 108 const struct sctp_endpoint *ep,
aecedeab
WY
109 const struct sctp_association *asoc,
110 void *arg,
111 sctp_cmd_seq_t *commands,
112 const __u8 *payload,
113 const size_t paylen);
114
52c1da39 115static sctp_disposition_t sctp_sf_violation_chunklen(
24cb81a6 116 struct net *net,
52c1da39
AB
117 const struct sctp_endpoint *ep,
118 const struct sctp_association *asoc,
119 const sctp_subtype_t type,
120 void *arg,
121 sctp_cmd_seq_t *commands);
1da177e4 122
6f4c618d 123static sctp_disposition_t sctp_sf_violation_paramlen(
24cb81a6 124 struct net *net,
6f4c618d
WY
125 const struct sctp_endpoint *ep,
126 const struct sctp_association *asoc,
127 const sctp_subtype_t type,
ba016670 128 void *arg, void *ext,
6f4c618d
WY
129 sctp_cmd_seq_t *commands);
130
aecedeab 131static sctp_disposition_t sctp_sf_violation_ctsn(
24cb81a6 132 struct net *net,
aecedeab
WY
133 const struct sctp_endpoint *ep,
134 const struct sctp_association *asoc,
135 const sctp_subtype_t type,
136 void *arg,
137 sctp_cmd_seq_t *commands);
138
ece25dfa 139static sctp_disposition_t sctp_sf_violation_chunk(
24cb81a6 140 struct net *net,
ece25dfa
VY
141 const struct sctp_endpoint *ep,
142 const struct sctp_association *asoc,
143 const sctp_subtype_t type,
144 void *arg,
145 sctp_cmd_seq_t *commands);
146
24cb81a6
EB
147static sctp_ierror_t sctp_sf_authenticate(struct net *net,
148 const struct sctp_endpoint *ep,
bbd0d598
VY
149 const struct sctp_association *asoc,
150 const sctp_subtype_t type,
151 struct sctp_chunk *chunk);
152
24cb81a6
EB
153static sctp_disposition_t __sctp_sf_do_9_1_abort(struct net *net,
154 const struct sctp_endpoint *ep,
75205f47
VY
155 const struct sctp_association *asoc,
156 const sctp_subtype_t type,
157 void *arg,
158 sctp_cmd_seq_t *commands);
159
1da177e4
LT
160/* Small helper function that checks if the chunk length
161 * is of the appropriate length. The 'required_length' argument
162 * is set to be the size of a specific chunk we are testing.
509e7a31
MRL
163 * Return Values: true = Valid length
164 * false = Invalid length
1da177e4
LT
165 *
166 */
509e7a31
MRL
167static inline bool
168sctp_chunk_length_valid(struct sctp_chunk *chunk, __u16 required_length)
1da177e4
LT
169{
170 __u16 chunk_length = ntohs(chunk->chunk_hdr->length);
171
26b87c78
DB
172 /* Previously already marked? */
173 if (unlikely(chunk->pdiscard))
509e7a31 174 return false;
1da177e4 175 if (unlikely(chunk_length < required_length))
509e7a31 176 return false;
1da177e4 177
509e7a31 178 return true;
1da177e4
LT
179}
180
181/**********************************************************
182 * These are the state functions for handling chunk events.
183 **********************************************************/
184
185/*
186 * Process the final SHUTDOWN COMPLETE.
187 *
188 * Section: 4 (C) (diagram), 9.2
189 * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify
190 * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be
191 * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint
192 * should stop the T2-shutdown timer and remove all knowledge of the
193 * association (and thus the association enters the CLOSED state).
194 *
047a2428 195 * Verification Tag: 8.5.1(C), sctpimpguide 2.41.
1da177e4
LT
196 * C) Rules for packet carrying SHUTDOWN COMPLETE:
197 * ...
047a2428
JF
198 * - The receiver of a SHUTDOWN COMPLETE shall accept the packet
199 * if the Verification Tag field of the packet matches its own tag and
200 * the T bit is not set
201 * OR
202 * it is set to its peer's tag and the T bit is set in the Chunk
203 * Flags.
204 * Otherwise, the receiver MUST silently discard the packet
205 * and take no further action. An endpoint MUST ignore the
206 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
1da177e4
LT
207 *
208 * Inputs
209 * (endpoint, asoc, chunk)
210 *
211 * Outputs
212 * (asoc, reply_msg, msg_up, timers, counters)
213 *
214 * The return value is the disposition of the chunk.
215 */
24cb81a6
EB
216sctp_disposition_t sctp_sf_do_4_C(struct net *net,
217 const struct sctp_endpoint *ep,
1da177e4
LT
218 const struct sctp_association *asoc,
219 const sctp_subtype_t type,
220 void *arg,
221 sctp_cmd_seq_t *commands)
222{
223 struct sctp_chunk *chunk = arg;
224 struct sctp_ulpevent *ev;
225
ece25dfa 226 if (!sctp_vtag_verify_either(chunk, asoc))
24cb81a6 227 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
ece25dfa 228
1da177e4
LT
229 /* RFC 2960 6.10 Bundling
230 *
231 * An endpoint MUST NOT bundle INIT, INIT ACK or
232 * SHUTDOWN COMPLETE with any other chunks.
233 */
234 if (!chunk->singleton)
24cb81a6 235 return sctp_sf_violation_chunk(net, ep, asoc, type, arg, commands);
1da177e4 236
ece25dfa
VY
237 /* Make sure that the SHUTDOWN_COMPLETE chunk has a valid length. */
238 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
24cb81a6 239 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
ece25dfa 240 commands);
1da177e4
LT
241
242 /* RFC 2960 10.2 SCTP-to-ULP
243 *
244 * H) SHUTDOWN COMPLETE notification
245 *
246 * When SCTP completes the shutdown procedures (section 9.2) this
247 * notification is passed to the upper layer.
248 */
249 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
a5a35e76 250 0, 0, 0, NULL, GFP_ATOMIC);
df7deeb5
VY
251 if (ev)
252 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
d808ad9a 253 SCTP_ULPEVENT(ev));
1da177e4
LT
254
255 /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint
256 * will verify that it is in SHUTDOWN-ACK-SENT state, if it is
257 * not the chunk should be discarded. If the endpoint is in
258 * the SHUTDOWN-ACK-SENT state the endpoint should stop the
259 * T2-shutdown timer and remove all knowledge of the
260 * association (and thus the association enters the CLOSED
261 * state).
262 */
263 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
264 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
265
266 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
267 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
268
269 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
270 SCTP_STATE(SCTP_STATE_CLOSED));
271
b01a2407
EB
272 SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS);
273 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
1da177e4
LT
274
275 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
276
277 return SCTP_DISPOSITION_DELETE_TCB;
1da177e4
LT
278}
279
280/*
281 * Respond to a normal INIT chunk.
282 * We are the side that is being asked for an association.
283 *
284 * Section: 5.1 Normal Establishment of an Association, B
285 * B) "Z" shall respond immediately with an INIT ACK chunk. The
286 * destination IP address of the INIT ACK MUST be set to the source
287 * IP address of the INIT to which this INIT ACK is responding. In
288 * the response, besides filling in other parameters, "Z" must set the
289 * Verification Tag field to Tag_A, and also provide its own
290 * Verification Tag (Tag_Z) in the Initiate Tag field.
291 *
d808ad9a 292 * Verification Tag: Must be 0.
1da177e4
LT
293 *
294 * Inputs
295 * (endpoint, asoc, chunk)
296 *
297 * Outputs
298 * (asoc, reply_msg, msg_up, timers, counters)
299 *
300 * The return value is the disposition of the chunk.
301 */
24cb81a6
EB
302sctp_disposition_t sctp_sf_do_5_1B_init(struct net *net,
303 const struct sctp_endpoint *ep,
1da177e4
LT
304 const struct sctp_association *asoc,
305 const sctp_subtype_t type,
306 void *arg,
307 sctp_cmd_seq_t *commands)
308{
309 struct sctp_chunk *chunk = arg;
310 struct sctp_chunk *repl;
311 struct sctp_association *new_asoc;
312 struct sctp_chunk *err_chunk;
313 struct sctp_packet *packet;
314 sctp_unrecognized_param_t *unk_param;
1da177e4
LT
315 int len;
316
317 /* 6.10 Bundling
318 * An endpoint MUST NOT bundle INIT, INIT ACK or
319 * SHUTDOWN COMPLETE with any other chunks.
d808ad9a 320 *
1da177e4
LT
321 * IG Section 2.11.2
322 * Furthermore, we require that the receiver of an INIT chunk MUST
323 * enforce these rules by silently discarding an arriving packet
324 * with an INIT chunk that is bundled with other chunks.
325 */
326 if (!chunk->singleton)
24cb81a6 327 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
328
329 /* If the packet is an OOTB packet which is temporarily on the
330 * control endpoint, respond with an ABORT.
331 */
2ce95503 332 if (ep == sctp_sk(net->sctp.ctl_sock)->ep) {
b01a2407 333 SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
24cb81a6 334 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
8190f89d 335 }
1da177e4 336
1da177e4 337 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
d808ad9a 338 * Tag.
1da177e4
LT
339 */
340 if (chunk->sctp_hdr->vtag != 0)
24cb81a6 341 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
1da177e4
LT
342
343 /* Make sure that the INIT chunk has a valid length.
344 * Normally, this would cause an ABORT with a Protocol Violation
345 * error, but since we don't have an association, we'll
346 * just discard the packet.
347 */
348 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
24cb81a6 349 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4 350
bec9640b
VY
351 /* If the INIT is coming toward a closing socket, we'll send back
352 * and ABORT. Essentially, this catches the race of INIT being
353 * backloged to the socket at the same time as the user isses close().
354 * Since the socket and all its associations are going away, we
355 * can treat this OOTB
356 */
357 if (sctp_sstate(ep->base.sk, CLOSING))
24cb81a6 358 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
bec9640b 359
1da177e4
LT
360 /* Verify the INIT chunk before processing it. */
361 err_chunk = NULL;
b14878cc 362 if (!sctp_verify_init(net, ep, asoc, chunk->chunk_hdr->type,
1da177e4
LT
363 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
364 &err_chunk)) {
365 /* This chunk contains fatal error. It is to be discarded.
366 * Send an ABORT, with causes if there is any.
367 */
368 if (err_chunk) {
24cb81a6 369 packet = sctp_abort_pkt_new(net, ep, asoc, arg,
1da177e4
LT
370 (__u8 *)(err_chunk->chunk_hdr) +
371 sizeof(sctp_chunkhdr_t),
372 ntohs(err_chunk->chunk_hdr->length) -
373 sizeof(sctp_chunkhdr_t));
374
375 sctp_chunk_free(err_chunk);
376
377 if (packet) {
378 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
379 SCTP_PACKET(packet));
b01a2407 380 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
1da177e4
LT
381 return SCTP_DISPOSITION_CONSUME;
382 } else {
383 return SCTP_DISPOSITION_NOMEM;
384 }
385 } else {
24cb81a6 386 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg,
1da177e4
LT
387 commands);
388 }
389 }
390
d808ad9a 391 /* Grab the INIT header. */
1da177e4
LT
392 chunk->subh.init_hdr = (sctp_inithdr_t *)chunk->skb->data;
393
394 /* Tag the variable length parameters. */
395 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
396
397 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
398 if (!new_asoc)
399 goto nomem;
400
409b95af
VY
401 if (sctp_assoc_set_bind_addr_from_ep(new_asoc,
402 sctp_scope(sctp_source(chunk)),
403 GFP_ATOMIC) < 0)
404 goto nomem_init;
405
1da177e4 406 /* The call, sctp_process_init(), can fail on memory allocation. */
de6becdc 407 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk),
1da177e4
LT
408 (sctp_init_chunk_t *)chunk->chunk_hdr,
409 GFP_ATOMIC))
410 goto nomem_init;
411
1da177e4
LT
412 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
413
414 /* If there are errors need to be reported for unknown parameters,
415 * make sure to reserve enough room in the INIT ACK for them.
416 */
417 len = 0;
418 if (err_chunk)
419 len = ntohs(err_chunk->chunk_hdr->length) -
420 sizeof(sctp_chunkhdr_t);
421
1da177e4
LT
422 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
423 if (!repl)
df7deeb5 424 goto nomem_init;
1da177e4
LT
425
426 /* If there are errors need to be reported for unknown parameters,
427 * include them in the outgoing INIT ACK as "Unrecognized parameter"
428 * parameter.
429 */
430 if (err_chunk) {
431 /* Get the "Unrecognized parameter" parameter(s) out of the
432 * ERROR chunk generated by sctp_verify_init(). Since the
433 * error cause code for "unknown parameter" and the
434 * "Unrecognized parameter" type is the same, we can
435 * construct the parameters in INIT ACK by copying the
436 * ERROR causes over.
437 */
438 unk_param = (sctp_unrecognized_param_t *)
439 ((__u8 *)(err_chunk->chunk_hdr) +
440 sizeof(sctp_chunkhdr_t));
441 /* Replace the cause code with the "Unrecognized parameter"
442 * parameter type.
443 */
444 sctp_addto_chunk(repl, len, unk_param);
445 sctp_chunk_free(err_chunk);
446 }
447
df7deeb5
VY
448 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
449
1da177e4
LT
450 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
451
452 /*
453 * Note: After sending out INIT ACK with the State Cookie parameter,
454 * "Z" MUST NOT allocate any resources, nor keep any states for the
455 * new association. Otherwise, "Z" will be vulnerable to resource
456 * attacks.
457 */
458 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
459
460 return SCTP_DISPOSITION_DELETE_TCB;
461
1da177e4
LT
462nomem_init:
463 sctp_association_free(new_asoc);
464nomem:
df7deeb5
VY
465 if (err_chunk)
466 sctp_chunk_free(err_chunk);
1da177e4
LT
467 return SCTP_DISPOSITION_NOMEM;
468}
469
470/*
471 * Respond to a normal INIT ACK chunk.
472 * We are the side that is initiating the association.
473 *
474 * Section: 5.1 Normal Establishment of an Association, C
475 * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init
476 * timer and leave COOKIE-WAIT state. "A" shall then send the State
477 * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start
478 * the T1-cookie timer, and enter the COOKIE-ECHOED state.
479 *
480 * Note: The COOKIE ECHO chunk can be bundled with any pending outbound
481 * DATA chunks, but it MUST be the first chunk in the packet and
482 * until the COOKIE ACK is returned the sender MUST NOT send any
483 * other packets to the peer.
484 *
485 * Verification Tag: 3.3.3
486 * If the value of the Initiate Tag in a received INIT ACK chunk is
487 * found to be 0, the receiver MUST treat it as an error and close the
488 * association by transmitting an ABORT.
489 *
490 * Inputs
491 * (endpoint, asoc, chunk)
492 *
493 * Outputs
494 * (asoc, reply_msg, msg_up, timers, counters)
495 *
496 * The return value is the disposition of the chunk.
497 */
24cb81a6
EB
498sctp_disposition_t sctp_sf_do_5_1C_ack(struct net *net,
499 const struct sctp_endpoint *ep,
1da177e4
LT
500 const struct sctp_association *asoc,
501 const sctp_subtype_t type,
502 void *arg,
503 sctp_cmd_seq_t *commands)
504{
505 struct sctp_chunk *chunk = arg;
506 sctp_init_chunk_t *initchunk;
1da177e4
LT
507 struct sctp_chunk *err_chunk;
508 struct sctp_packet *packet;
1da177e4
LT
509
510 if (!sctp_vtag_verify(chunk, asoc))
24cb81a6 511 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4 512
1da177e4
LT
513 /* 6.10 Bundling
514 * An endpoint MUST NOT bundle INIT, INIT ACK or
515 * SHUTDOWN COMPLETE with any other chunks.
516 */
517 if (!chunk->singleton)
24cb81a6 518 return sctp_sf_violation_chunk(net, ep, asoc, type, arg, commands);
1da177e4 519
ece25dfa
VY
520 /* Make sure that the INIT-ACK chunk has a valid length */
521 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_initack_chunk_t)))
24cb81a6 522 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
ece25dfa 523 commands);
1da177e4
LT
524 /* Grab the INIT header. */
525 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
526
1da177e4
LT
527 /* Verify the INIT chunk before processing it. */
528 err_chunk = NULL;
b14878cc 529 if (!sctp_verify_init(net, ep, asoc, chunk->chunk_hdr->type,
1da177e4
LT
530 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
531 &err_chunk)) {
532
853f4b50
VY
533 sctp_error_t error = SCTP_ERROR_NO_RESOURCE;
534
1da177e4 535 /* This chunk contains fatal error. It is to be discarded.
d6701191
VY
536 * Send an ABORT, with causes. If there are no causes,
537 * then there wasn't enough memory. Just terminate
538 * the association.
1da177e4
LT
539 */
540 if (err_chunk) {
24cb81a6 541 packet = sctp_abort_pkt_new(net, ep, asoc, arg,
1da177e4
LT
542 (__u8 *)(err_chunk->chunk_hdr) +
543 sizeof(sctp_chunkhdr_t),
544 ntohs(err_chunk->chunk_hdr->length) -
545 sizeof(sctp_chunkhdr_t));
546
547 sctp_chunk_free(err_chunk);
548
549 if (packet) {
550 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
551 SCTP_PACKET(packet));
24cb81a6 552 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
8de8c873 553 error = SCTP_ERROR_INV_PARAM;
1da177e4 554 }
1da177e4 555 }
bbd0d598
VY
556
557 /* SCTP-AUTH, Section 6.3:
558 * It should be noted that if the receiver wants to tear
559 * down an association in an authenticated way only, the
560 * handling of malformed packets should not result in
561 * tearing down the association.
562 *
563 * This means that if we only want to abort associations
564 * in an authenticated way (i.e AUTH+ABORT), then we
25985edc 565 * can't destroy this association just because the packet
bbd0d598
VY
566 * was malformed.
567 */
568 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
24cb81a6 569 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
bbd0d598 570
24cb81a6
EB
571 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
572 return sctp_stop_t1_and_abort(net, commands, error, ECONNREFUSED,
8de8c873 573 asoc, chunk->transport);
1da177e4
LT
574 }
575
576 /* Tag the variable length parameters. Note that we never
577 * convert the parameters in an INIT chunk.
578 */
579 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
580
581 initchunk = (sctp_init_chunk_t *) chunk->chunk_hdr;
582
583 sctp_add_cmd_sf(commands, SCTP_CMD_PEER_INIT,
584 SCTP_PEER_INIT(initchunk));
585
3f7a87d2
FF
586 /* Reset init error count upon receipt of INIT-ACK. */
587 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
588
1da177e4
LT
589 /* 5.1 C) "A" shall stop the T1-init timer and leave
590 * COOKIE-WAIT state. "A" shall then ... start the T1-cookie
591 * timer, and enter the COOKIE-ECHOED state.
592 */
593 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
594 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
595 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
596 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
597 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
598 SCTP_STATE(SCTP_STATE_COOKIE_ECHOED));
599
730fc3d0
VY
600 /* SCTP-AUTH: genereate the assocition shared keys so that
601 * we can potentially signe the COOKIE-ECHO.
602 */
603 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_SHKEY, SCTP_NULL());
604
1da177e4
LT
605 /* 5.1 C) "A" shall then send the State Cookie received in the
606 * INIT ACK chunk in a COOKIE ECHO chunk, ...
607 */
608 /* If there is any errors to report, send the ERROR chunk generated
609 * for unknown parameters as well.
610 */
611 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_COOKIE_ECHO,
612 SCTP_CHUNK(err_chunk));
613
614 return SCTP_DISPOSITION_CONSUME;
1da177e4
LT
615}
616
617/*
618 * Respond to a normal COOKIE ECHO chunk.
619 * We are the side that is being asked for an association.
620 *
621 * Section: 5.1 Normal Establishment of an Association, D
622 * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply
623 * with a COOKIE ACK chunk after building a TCB and moving to
624 * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with
625 * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK
626 * chunk MUST be the first chunk in the packet.
627 *
628 * IMPLEMENTATION NOTE: An implementation may choose to send the
629 * Communication Up notification to the SCTP user upon reception
630 * of a valid COOKIE ECHO chunk.
631 *
632 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
633 * D) Rules for packet carrying a COOKIE ECHO
634 *
635 * - When sending a COOKIE ECHO, the endpoint MUST use the value of the
636 * Initial Tag received in the INIT ACK.
637 *
638 * - The receiver of a COOKIE ECHO follows the procedures in Section 5.
639 *
640 * Inputs
641 * (endpoint, asoc, chunk)
642 *
643 * Outputs
644 * (asoc, reply_msg, msg_up, timers, counters)
645 *
646 * The return value is the disposition of the chunk.
647 */
24cb81a6
EB
648sctp_disposition_t sctp_sf_do_5_1D_ce(struct net *net,
649 const struct sctp_endpoint *ep,
1da177e4
LT
650 const struct sctp_association *asoc,
651 const sctp_subtype_t type, void *arg,
652 sctp_cmd_seq_t *commands)
653{
654 struct sctp_chunk *chunk = arg;
655 struct sctp_association *new_asoc;
656 sctp_init_chunk_t *peer_init;
657 struct sctp_chunk *repl;
df7deeb5 658 struct sctp_ulpevent *ev, *ai_ev = NULL;
1da177e4
LT
659 int error = 0;
660 struct sctp_chunk *err_chk_p;
609ee467 661 struct sock *sk;
1da177e4
LT
662
663 /* If the packet is an OOTB packet which is temporarily on the
664 * control endpoint, respond with an ABORT.
665 */
2ce95503 666 if (ep == sctp_sk(net->sctp.ctl_sock)->ep) {
b01a2407 667 SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
24cb81a6 668 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
8190f89d 669 }
1da177e4
LT
670
671 /* Make sure that the COOKIE_ECHO chunk has a valid length.
672 * In this case, we check that we have enough for at least a
673 * chunk header. More detailed verification is done
674 * in sctp_unpack_cookie().
675 */
676 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
24cb81a6 677 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4 678
609ee467
VY
679 /* If the endpoint is not listening or if the number of associations
680 * on the TCP-style socket exceed the max backlog, respond with an
681 * ABORT.
682 */
683 sk = ep->base.sk;
684 if (!sctp_sstate(sk, LISTENING) ||
685 (sctp_style(sk, TCP) && sk_acceptq_is_full(sk)))
24cb81a6 686 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
609ee467 687
1da177e4
LT
688 /* "Decode" the chunk. We have no optional parameters so we
689 * are in good shape.
690 */
d808ad9a 691 chunk->subh.cookie_hdr =
1da177e4 692 (struct sctp_signed_cookie *)chunk->skb->data;
62b08083
SS
693 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
694 sizeof(sctp_chunkhdr_t)))
695 goto nomem;
1da177e4
LT
696
697 /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
698 * "Z" will reply with a COOKIE ACK chunk after building a TCB
699 * and moving to the ESTABLISHED state.
700 */
701 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
702 &err_chk_p);
703
704 /* FIXME:
705 * If the re-build failed, what is the proper error path
706 * from here?
707 *
708 * [We should abort the association. --piggy]
709 */
710 if (!new_asoc) {
711 /* FIXME: Several errors are possible. A bad cookie should
712 * be silently discarded, but think about logging it too.
713 */
714 switch (error) {
715 case -SCTP_IERROR_NOMEM:
716 goto nomem;
717
718 case -SCTP_IERROR_STALE_COOKIE:
24cb81a6 719 sctp_send_stale_cookie_err(net, ep, asoc, chunk, commands,
1da177e4 720 err_chk_p);
24cb81a6 721 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
722
723 case -SCTP_IERROR_BAD_SIG:
724 default:
24cb81a6 725 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3ff50b79 726 }
1da177e4
LT
727 }
728
1da177e4 729
df7deeb5
VY
730 /* Delay state machine commands until later.
731 *
732 * Re-build the bind address for the association is done in
1da177e4
LT
733 * the sctp_unpack_cookie() already.
734 */
735 /* This is a brand-new association, so these are not yet side
736 * effects--it is safe to run them here.
737 */
738 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
739
de6becdc 740 if (!sctp_process_init(new_asoc, chunk,
6a1e5f33 741 &chunk->subh.cookie_hdr->c.peer_addr,
1da177e4
LT
742 peer_init, GFP_ATOMIC))
743 goto nomem_init;
744
730fc3d0
VY
745 /* SCTP-AUTH: Now that we've populate required fields in
746 * sctp_process_init, set up the assocaition shared keys as
747 * necessary so that we can potentially authenticate the ACK
748 */
749 error = sctp_auth_asoc_init_active_key(new_asoc, GFP_ATOMIC);
750 if (error)
751 goto nomem_init;
752
bbd0d598
VY
753 /* SCTP-AUTH: auth_chunk pointer is only set when the cookie-echo
754 * is supposed to be authenticated and we have to do delayed
755 * authentication. We've just recreated the association using
756 * the information in the cookie and now it's much easier to
757 * do the authentication.
758 */
759 if (chunk->auth_chunk) {
760 struct sctp_chunk auth;
761 sctp_ierror_t ret;
762
ec0223ec
DB
763 /* Make sure that we and the peer are AUTH capable */
764 if (!net->sctp.auth_enable || !new_asoc->peer.auth_capable) {
ec0223ec
DB
765 sctp_association_free(new_asoc);
766 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
767 }
768
bbd0d598
VY
769 /* set-up our fake chunk so that we can process it */
770 auth.skb = chunk->auth_chunk;
771 auth.asoc = chunk->asoc;
772 auth.sctp_hdr = chunk->sctp_hdr;
773 auth.chunk_hdr = (sctp_chunkhdr_t *)skb_push(chunk->auth_chunk,
774 sizeof(sctp_chunkhdr_t));
775 skb_pull(chunk->auth_chunk, sizeof(sctp_chunkhdr_t));
776 auth.transport = chunk->transport;
777
24cb81a6 778 ret = sctp_sf_authenticate(net, ep, new_asoc, type, &auth);
bbd0d598
VY
779 if (ret != SCTP_IERROR_NO_ERROR) {
780 sctp_association_free(new_asoc);
24cb81a6 781 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
bbd0d598
VY
782 }
783 }
784
1da177e4
LT
785 repl = sctp_make_cookie_ack(new_asoc, chunk);
786 if (!repl)
df7deeb5 787 goto nomem_init;
1da177e4
LT
788
789 /* RFC 2960 5.1 Normal Establishment of an Association
790 *
791 * D) IMPLEMENTATION NOTE: An implementation may choose to
792 * send the Communication Up notification to the SCTP user
793 * upon reception of a valid COOKIE ECHO chunk.
794 */
795 ev = sctp_ulpevent_make_assoc_change(new_asoc, 0, SCTP_COMM_UP, 0,
796 new_asoc->c.sinit_num_ostreams,
797 new_asoc->c.sinit_max_instreams,
a5a35e76 798 NULL, GFP_ATOMIC);
1da177e4
LT
799 if (!ev)
800 goto nomem_ev;
801
d808ad9a 802 /* Sockets API Draft Section 5.3.1.6
0f3fffd8 803 * When a peer sends a Adaptation Layer Indication parameter , SCTP
1da177e4 804 * delivers this notification to inform the application that of the
0f3fffd8 805 * peers requested adaptation layer.
1da177e4 806 */
0f3fffd8
ISJ
807 if (new_asoc->peer.adaptation_ind) {
808 ai_ev = sctp_ulpevent_make_adaptation_indication(new_asoc,
1da177e4 809 GFP_ATOMIC);
df7deeb5
VY
810 if (!ai_ev)
811 goto nomem_aiev;
812 }
813
814 /* Add all the state machine commands now since we've created
815 * everything. This way we don't introduce memory corruptions
816 * during side-effect processing and correclty count established
817 * associations.
818 */
819 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
820 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
821 SCTP_STATE(SCTP_STATE_ESTABLISHED));
b01a2407
EB
822 SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
823 SCTP_INC_STATS(net, SCTP_MIB_PASSIVEESTABS);
df7deeb5
VY
824 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
825
9f70f46b 826 if (new_asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
df7deeb5
VY
827 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
828 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
829
df7deeb5
VY
830 /* This will send the COOKIE ACK */
831 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
832
833 /* Queue the ASSOC_CHANGE event */
834 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
835
836 /* Send up the Adaptation Layer Indication event */
837 if (ai_ev)
1da177e4 838 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
df7deeb5 839 SCTP_ULPEVENT(ai_ev));
1da177e4
LT
840
841 return SCTP_DISPOSITION_CONSUME;
842
df7deeb5
VY
843nomem_aiev:
844 sctp_ulpevent_free(ev);
1da177e4
LT
845nomem_ev:
846 sctp_chunk_free(repl);
1da177e4
LT
847nomem_init:
848 sctp_association_free(new_asoc);
849nomem:
850 return SCTP_DISPOSITION_NOMEM;
851}
852
853/*
854 * Respond to a normal COOKIE ACK chunk.
b52effd2 855 * We are the side that is asking for an association.
1da177e4
LT
856 *
857 * RFC 2960 5.1 Normal Establishment of an Association
858 *
859 * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the
860 * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie
861 * timer. It may also notify its ULP about the successful
862 * establishment of the association with a Communication Up
863 * notification (see Section 10).
864 *
865 * Verification Tag:
866 * Inputs
867 * (endpoint, asoc, chunk)
868 *
869 * Outputs
870 * (asoc, reply_msg, msg_up, timers, counters)
871 *
872 * The return value is the disposition of the chunk.
873 */
24cb81a6
EB
874sctp_disposition_t sctp_sf_do_5_1E_ca(struct net *net,
875 const struct sctp_endpoint *ep,
1da177e4
LT
876 const struct sctp_association *asoc,
877 const sctp_subtype_t type, void *arg,
878 sctp_cmd_seq_t *commands)
879{
880 struct sctp_chunk *chunk = arg;
881 struct sctp_ulpevent *ev;
882
883 if (!sctp_vtag_verify(chunk, asoc))
24cb81a6 884 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
885
886 /* Verify that the chunk length for the COOKIE-ACK is OK.
887 * If we don't do this, any bundled chunks may be junked.
888 */
889 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
24cb81a6 890 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4
LT
891 commands);
892
893 /* Reset init error count upon receipt of COOKIE-ACK,
894 * to avoid problems with the managemement of this
895 * counter in stale cookie situations when a transition back
896 * from the COOKIE-ECHOED state to the COOKIE-WAIT
897 * state is performed.
898 */
3f7a87d2 899 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
1da177e4
LT
900
901 /* RFC 2960 5.1 Normal Establishment of an Association
902 *
903 * E) Upon reception of the COOKIE ACK, endpoint "A" will move
904 * from the COOKIE-ECHOED state to the ESTABLISHED state,
905 * stopping the T1-cookie timer.
906 */
907 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
908 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
909 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
910 SCTP_STATE(SCTP_STATE_ESTABLISHED));
b01a2407
EB
911 SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
912 SCTP_INC_STATS(net, SCTP_MIB_ACTIVEESTABS);
1da177e4 913 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
9f70f46b 914 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
1da177e4
LT
915 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
916 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
1da177e4
LT
917
918 /* It may also notify its ULP about the successful
919 * establishment of the association with a Communication Up
920 * notification (see Section 10).
921 */
922 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP,
923 0, asoc->c.sinit_num_ostreams,
924 asoc->c.sinit_max_instreams,
a5a35e76 925 NULL, GFP_ATOMIC);
1da177e4
LT
926
927 if (!ev)
928 goto nomem;
929
930 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
931
932 /* Sockets API Draft Section 5.3.1.6
0f3fffd8 933 * When a peer sends a Adaptation Layer Indication parameter , SCTP
1da177e4 934 * delivers this notification to inform the application that of the
0f3fffd8 935 * peers requested adaptation layer.
1da177e4 936 */
0f3fffd8
ISJ
937 if (asoc->peer.adaptation_ind) {
938 ev = sctp_ulpevent_make_adaptation_indication(asoc, GFP_ATOMIC);
1da177e4
LT
939 if (!ev)
940 goto nomem;
941
942 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
943 SCTP_ULPEVENT(ev));
944 }
945
946 return SCTP_DISPOSITION_CONSUME;
947nomem:
948 return SCTP_DISPOSITION_NOMEM;
949}
950
951/* Generate and sendout a heartbeat packet. */
952static sctp_disposition_t sctp_sf_heartbeat(const struct sctp_endpoint *ep,
953 const struct sctp_association *asoc,
954 const sctp_subtype_t type,
955 void *arg,
956 sctp_cmd_seq_t *commands)
957{
958 struct sctp_transport *transport = (struct sctp_transport *) arg;
959 struct sctp_chunk *reply;
1da177e4
LT
960
961 /* Send a heartbeat to our peer. */
92c73af5 962 reply = sctp_make_heartbeat(asoc, transport);
1da177e4
LT
963 if (!reply)
964 return SCTP_DISPOSITION_NOMEM;
965
966 /* Set rto_pending indicating that an RTT measurement
967 * is started with this heartbeat chunk.
968 */
969 sctp_add_cmd_sf(commands, SCTP_CMD_RTO_PENDING,
970 SCTP_TRANSPORT(transport));
971
972 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
973 return SCTP_DISPOSITION_CONSUME;
974}
975
976/* Generate a HEARTBEAT packet on the given transport. */
24cb81a6
EB
977sctp_disposition_t sctp_sf_sendbeat_8_3(struct net *net,
978 const struct sctp_endpoint *ep,
1da177e4
LT
979 const struct sctp_association *asoc,
980 const sctp_subtype_t type,
981 void *arg,
982 sctp_cmd_seq_t *commands)
983{
984 struct sctp_transport *transport = (struct sctp_transport *) arg;
985
b9f84786 986 if (asoc->overall_error_count >= asoc->max_retrans) {
8de8c873
SS
987 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
988 SCTP_ERROR(ETIMEDOUT));
1da177e4
LT
989 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
990 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5be291fe 991 SCTP_PERR(SCTP_ERROR_NO_ERROR));
b01a2407
EB
992 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
993 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
1da177e4
LT
994 return SCTP_DISPOSITION_DELETE_TCB;
995 }
996
997 /* Section 3.3.5.
998 * The Sender-specific Heartbeat Info field should normally include
999 * information about the sender's current time when this HEARTBEAT
1000 * chunk is sent and the destination transport address to which this
1001 * HEARTBEAT is sent (see Section 8.3).
1002 */
1003
52ccb8e9 1004 if (transport->param_flags & SPP_HB_ENABLE) {
1da177e4
LT
1005 if (SCTP_DISPOSITION_NOMEM ==
1006 sctp_sf_heartbeat(ep, asoc, type, arg,
1007 commands))
1008 return SCTP_DISPOSITION_NOMEM;
245cba7e 1009
1da177e4
LT
1010 /* Set transport error counter and association error counter
1011 * when sending heartbeat.
1012 */
7e99013a 1013 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_HB_SENT,
1da177e4
LT
1014 SCTP_TRANSPORT(transport));
1015 }
245cba7e
VY
1016 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_IDLE,
1017 SCTP_TRANSPORT(transport));
1da177e4
LT
1018 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMER_UPDATE,
1019 SCTP_TRANSPORT(transport));
1020
d808ad9a 1021 return SCTP_DISPOSITION_CONSUME;
1da177e4
LT
1022}
1023
7b9438de
XL
1024/* resend asoc strreset_chunk. */
1025sctp_disposition_t sctp_sf_send_reconf(struct net *net,
1026 const struct sctp_endpoint *ep,
1027 const struct sctp_association *asoc,
1028 const sctp_subtype_t type, void *arg,
1029 sctp_cmd_seq_t *commands)
1030{
1031 struct sctp_transport *transport = arg;
1032
1033 if (asoc->overall_error_count >= asoc->max_retrans) {
1034 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
1035 SCTP_ERROR(ETIMEDOUT));
1036 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
1037 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
1038 SCTP_PERR(SCTP_ERROR_NO_ERROR));
1039 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
1040 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
1041 return SCTP_DISPOSITION_DELETE_TCB;
1042 }
1043
1044 sctp_chunk_hold(asoc->strreset_chunk);
1045 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1046 SCTP_CHUNK(asoc->strreset_chunk));
1047 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
1048
1049 return SCTP_DISPOSITION_CONSUME;
1050}
1051
1da177e4
LT
1052/*
1053 * Process an heartbeat request.
1054 *
1055 * Section: 8.3 Path Heartbeat
1056 * The receiver of the HEARTBEAT should immediately respond with a
1057 * HEARTBEAT ACK that contains the Heartbeat Information field copied
1058 * from the received HEARTBEAT chunk.
1059 *
1060 * Verification Tag: 8.5 Verification Tag [Normal verification]
1061 * When receiving an SCTP packet, the endpoint MUST ensure that the
1062 * value in the Verification Tag field of the received SCTP packet
1063 * matches its own Tag. If the received Verification Tag value does not
1064 * match the receiver's own tag value, the receiver shall silently
1065 * discard the packet and shall not process it any further except for
1066 * those cases listed in Section 8.5.1 below.
1067 *
1068 * Inputs
1069 * (endpoint, asoc, chunk)
1070 *
1071 * Outputs
1072 * (asoc, reply_msg, msg_up, timers, counters)
1073 *
1074 * The return value is the disposition of the chunk.
1075 */
24cb81a6
EB
1076sctp_disposition_t sctp_sf_beat_8_3(struct net *net,
1077 const struct sctp_endpoint *ep,
1da177e4
LT
1078 const struct sctp_association *asoc,
1079 const sctp_subtype_t type,
1080 void *arg,
1081 sctp_cmd_seq_t *commands)
1082{
06a31e2b 1083 sctp_paramhdr_t *param_hdr;
1da177e4
LT
1084 struct sctp_chunk *chunk = arg;
1085 struct sctp_chunk *reply;
1086 size_t paylen = 0;
1087
1088 if (!sctp_vtag_verify(chunk, asoc))
24cb81a6 1089 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
1090
1091 /* Make sure that the HEARTBEAT chunk has a valid length. */
1092 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t)))
24cb81a6 1093 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4
LT
1094 commands);
1095
1096 /* 8.3 The receiver of the HEARTBEAT should immediately
1097 * respond with a HEARTBEAT ACK that contains the Heartbeat
1098 * Information field copied from the received HEARTBEAT chunk.
1099 */
1100 chunk->subh.hb_hdr = (sctp_heartbeathdr_t *) chunk->skb->data;
06a31e2b 1101 param_hdr = (sctp_paramhdr_t *) chunk->subh.hb_hdr;
1da177e4 1102 paylen = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
06a31e2b
TG
1103
1104 if (ntohs(param_hdr->length) > paylen)
1105 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
1106 param_hdr, commands);
1107
62b08083
SS
1108 if (!pskb_pull(chunk->skb, paylen))
1109 goto nomem;
1da177e4 1110
06a31e2b 1111 reply = sctp_make_heartbeat_ack(asoc, chunk, param_hdr, paylen);
1da177e4
LT
1112 if (!reply)
1113 goto nomem;
1114
1115 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
1116 return SCTP_DISPOSITION_CONSUME;
1117
1118nomem:
1119 return SCTP_DISPOSITION_NOMEM;
1120}
1121
1122/*
1123 * Process the returning HEARTBEAT ACK.
1124 *
1125 * Section: 8.3 Path Heartbeat
1126 * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT
1127 * should clear the error counter of the destination transport
1128 * address to which the HEARTBEAT was sent, and mark the destination
1129 * transport address as active if it is not so marked. The endpoint may
1130 * optionally report to the upper layer when an inactive destination
1131 * address is marked as active due to the reception of the latest
1132 * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also
1133 * clear the association overall error count as well (as defined
1134 * in section 8.1).
1135 *
1136 * The receiver of the HEARTBEAT ACK should also perform an RTT
1137 * measurement for that destination transport address using the time
1138 * value carried in the HEARTBEAT ACK chunk.
1139 *
1140 * Verification Tag: 8.5 Verification Tag [Normal verification]
1141 *
1142 * Inputs
1143 * (endpoint, asoc, chunk)
1144 *
1145 * Outputs
1146 * (asoc, reply_msg, msg_up, timers, counters)
1147 *
1148 * The return value is the disposition of the chunk.
1149 */
24cb81a6
EB
1150sctp_disposition_t sctp_sf_backbeat_8_3(struct net *net,
1151 const struct sctp_endpoint *ep,
1da177e4
LT
1152 const struct sctp_association *asoc,
1153 const sctp_subtype_t type,
1154 void *arg,
1155 sctp_cmd_seq_t *commands)
1156{
1157 struct sctp_chunk *chunk = arg;
1158 union sctp_addr from_addr;
1159 struct sctp_transport *link;
1160 sctp_sender_hb_info_t *hbinfo;
1161 unsigned long max_interval;
1162
1163 if (!sctp_vtag_verify(chunk, asoc))
24cb81a6 1164 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
1165
1166 /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */
dadb50cc
WY
1167 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t) +
1168 sizeof(sctp_sender_hb_info_t)))
24cb81a6 1169 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4
LT
1170 commands);
1171
1172 hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
a601266e
VY
1173 /* Make sure that the length of the parameter is what we expect */
1174 if (ntohs(hbinfo->param_hdr.length) !=
1175 sizeof(sctp_sender_hb_info_t)) {
1176 return SCTP_DISPOSITION_DISCARD;
1177 }
1178
1da177e4 1179 from_addr = hbinfo->daddr;
63de08f4 1180 link = sctp_assoc_lookup_paddr(asoc, &from_addr);
1da177e4
LT
1181
1182 /* This should never happen, but lets log it if so. */
3f7a87d2
FF
1183 if (unlikely(!link)) {
1184 if (from_addr.sa.sa_family == AF_INET6) {
e87cc472
JP
1185 net_warn_ratelimited("%s association %p could not find address %pI6\n",
1186 __func__,
1187 asoc,
1188 &from_addr.v6.sin6_addr);
3f7a87d2 1189 } else {
e87cc472
JP
1190 net_warn_ratelimited("%s association %p could not find address %pI4\n",
1191 __func__,
1192 asoc,
1193 &from_addr.v4.sin_addr.s_addr);
3f7a87d2 1194 }
1da177e4
LT
1195 return SCTP_DISPOSITION_DISCARD;
1196 }
1197
ad8fec17
SS
1198 /* Validate the 64-bit random nonce. */
1199 if (hbinfo->hb_nonce != link->hb_nonce)
1200 return SCTP_DISPOSITION_DISCARD;
1201
52ccb8e9 1202 max_interval = link->hbinterval + link->rto;
1da177e4
LT
1203
1204 /* Check if the timestamp looks valid. */
1205 if (time_after(hbinfo->sent_at, jiffies) ||
1206 time_after(jiffies, hbinfo->sent_at + max_interval)) {
bb33381d
DB
1207 pr_debug("%s: HEARTBEAT ACK with invalid timestamp received "
1208 "for transport:%p\n", __func__, link);
1209
1da177e4
LT
1210 return SCTP_DISPOSITION_DISCARD;
1211 }
1212
1213 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of
1214 * the HEARTBEAT should clear the error counter of the
1215 * destination transport address to which the HEARTBEAT was
1216 * sent and mark the destination transport address as active if
1217 * it is not so marked.
1218 */
1219 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_ON, SCTP_TRANSPORT(link));
1220
1221 return SCTP_DISPOSITION_CONSUME;
1222}
1223
1224/* Helper function to send out an abort for the restart
1225 * condition.
1226 */
2ce95503 1227static int sctp_sf_send_restart_abort(struct net *net, union sctp_addr *ssa,
1da177e4
LT
1228 struct sctp_chunk *init,
1229 sctp_cmd_seq_t *commands)
1230{
1231 int len;
1232 struct sctp_packet *pkt;
1233 union sctp_addr_param *addrparm;
1234 struct sctp_errhdr *errhdr;
1235 struct sctp_endpoint *ep;
1236 char buffer[sizeof(struct sctp_errhdr)+sizeof(union sctp_addr_param)];
1237 struct sctp_af *af = sctp_get_af_specific(ssa->v4.sin_family);
1238
1239 /* Build the error on the stack. We are way to malloc crazy
1240 * throughout the code today.
1241 */
1242 errhdr = (struct sctp_errhdr *)buffer;
1243 addrparm = (union sctp_addr_param *)errhdr->variable;
1244
1245 /* Copy into a parm format. */
1246 len = af->to_addr_param(ssa, addrparm);
1247 len += sizeof(sctp_errhdr_t);
1248
1249 errhdr->cause = SCTP_ERROR_RESTART;
1250 errhdr->length = htons(len);
1251
1252 /* Assign to the control socket. */
2ce95503 1253 ep = sctp_sk(net->sctp.ctl_sock)->ep;
1da177e4
LT
1254
1255 /* Association is NULL since this may be a restart attack and we
1256 * want to send back the attacker's vtag.
1257 */
24cb81a6 1258 pkt = sctp_abort_pkt_new(net, ep, NULL, init, errhdr, len);
1da177e4
LT
1259
1260 if (!pkt)
1261 goto out;
1262 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, SCTP_PACKET(pkt));
1263
b01a2407 1264 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
1da177e4
LT
1265
1266 /* Discard the rest of the inbound packet. */
1267 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
1268
1269out:
1270 /* Even if there is no memory, treat as a failure so
1271 * the packet will get dropped.
1272 */
1273 return 0;
1274}
1275
123031c0
JP
1276static bool list_has_sctp_addr(const struct list_head *list,
1277 union sctp_addr *ipaddr)
1278{
1279 struct sctp_transport *addr;
1280
1281 list_for_each_entry(addr, list, transports) {
1282 if (sctp_cmp_addr_exact(ipaddr, &addr->ipaddr))
1283 return true;
1284 }
1285
1286 return false;
1287}
1da177e4
LT
1288/* A restart is occurring, check to make sure no new addresses
1289 * are being added as we may be under a takeover attack.
1290 */
1291static int sctp_sf_check_restart_addrs(const struct sctp_association *new_asoc,
1292 const struct sctp_association *asoc,
1293 struct sctp_chunk *init,
1294 sctp_cmd_seq_t *commands)
1295{
2ce95503 1296 struct net *net = sock_net(new_asoc->base.sk);
123031c0
JP
1297 struct sctp_transport *new_addr;
1298 int ret = 1;
1da177e4 1299
123031c0 1300 /* Implementor's Guide - Section 5.2.2
1da177e4
LT
1301 * ...
1302 * Before responding the endpoint MUST check to see if the
1303 * unexpected INIT adds new addresses to the association. If new
1304 * addresses are added to the association, the endpoint MUST respond
1305 * with an ABORT..
1306 */
1307
1308 /* Search through all current addresses and make sure
1309 * we aren't adding any new ones.
1310 */
9dbc15f0 1311 list_for_each_entry(new_addr, &new_asoc->peer.transport_addr_list,
123031c0
JP
1312 transports) {
1313 if (!list_has_sctp_addr(&asoc->peer.transport_addr_list,
1314 &new_addr->ipaddr)) {
2ce95503 1315 sctp_sf_send_restart_abort(net, &new_addr->ipaddr, init,
123031c0
JP
1316 commands);
1317 ret = 0;
1da177e4 1318 break;
123031c0 1319 }
1da177e4
LT
1320 }
1321
1322 /* Return success if all addresses were found. */
123031c0 1323 return ret;
1da177e4
LT
1324}
1325
1326/* Populate the verification/tie tags based on overlapping INIT
1327 * scenario.
1328 *
1329 * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state.
1330 */
1331static void sctp_tietags_populate(struct sctp_association *new_asoc,
1332 const struct sctp_association *asoc)
1333{
1334 switch (asoc->state) {
1335
1336 /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */
1337
1338 case SCTP_STATE_COOKIE_WAIT:
1339 new_asoc->c.my_vtag = asoc->c.my_vtag;
1340 new_asoc->c.my_ttag = asoc->c.my_vtag;
1341 new_asoc->c.peer_ttag = 0;
1342 break;
1343
1344 case SCTP_STATE_COOKIE_ECHOED:
1345 new_asoc->c.my_vtag = asoc->c.my_vtag;
1346 new_asoc->c.my_ttag = asoc->c.my_vtag;
1347 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1348 break;
1349
1350 /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED,
1351 * COOKIE-WAIT and SHUTDOWN-ACK-SENT
1352 */
1353 default:
1354 new_asoc->c.my_ttag = asoc->c.my_vtag;
1355 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1356 break;
3ff50b79 1357 }
1da177e4
LT
1358
1359 /* Other parameters for the endpoint SHOULD be copied from the
1360 * existing parameters of the association (e.g. number of
1361 * outbound streams) into the INIT ACK and cookie.
1362 */
1363 new_asoc->rwnd = asoc->rwnd;
1364 new_asoc->c.sinit_num_ostreams = asoc->c.sinit_num_ostreams;
1365 new_asoc->c.sinit_max_instreams = asoc->c.sinit_max_instreams;
1366 new_asoc->c.initial_tsn = asoc->c.initial_tsn;
1367}
1368
1369/*
1370 * Compare vtag/tietag values to determine unexpected COOKIE-ECHO
1371 * handling action.
1372 *
1373 * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists.
1374 *
1375 * Returns value representing action to be taken. These action values
1376 * correspond to Action/Description values in RFC 2960, Table 2.
1377 */
1378static char sctp_tietags_compare(struct sctp_association *new_asoc,
1379 const struct sctp_association *asoc)
1380{
1381 /* In this case, the peer may have restarted. */
1382 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1383 (asoc->c.peer_vtag != new_asoc->c.peer_vtag) &&
1384 (asoc->c.my_vtag == new_asoc->c.my_ttag) &&
1385 (asoc->c.peer_vtag == new_asoc->c.peer_ttag))
1386 return 'A';
1387
1388 /* Collision case B. */
1389 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1390 ((asoc->c.peer_vtag != new_asoc->c.peer_vtag) ||
1391 (0 == asoc->c.peer_vtag))) {
1392 return 'B';
1393 }
1394
1395 /* Collision case D. */
1396 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1397 (asoc->c.peer_vtag == new_asoc->c.peer_vtag))
1398 return 'D';
1399
1400 /* Collision case C. */
1401 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1402 (asoc->c.peer_vtag == new_asoc->c.peer_vtag) &&
1403 (0 == new_asoc->c.my_ttag) &&
1404 (0 == new_asoc->c.peer_ttag))
1405 return 'C';
1406
1407 /* No match to any of the special cases; discard this packet. */
1408 return 'E';
1409}
1410
1411/* Common helper routine for both duplicate and simulataneous INIT
1412 * chunk handling.
1413 */
1414static sctp_disposition_t sctp_sf_do_unexpected_init(
24cb81a6 1415 struct net *net,
1da177e4
LT
1416 const struct sctp_endpoint *ep,
1417 const struct sctp_association *asoc,
1418 const sctp_subtype_t type,
1419 void *arg, sctp_cmd_seq_t *commands)
1420{
1421 sctp_disposition_t retval;
1422 struct sctp_chunk *chunk = arg;
1423 struct sctp_chunk *repl;
1424 struct sctp_association *new_asoc;
1425 struct sctp_chunk *err_chunk;
1426 struct sctp_packet *packet;
1427 sctp_unrecognized_param_t *unk_param;
1428 int len;
1429
1430 /* 6.10 Bundling
1431 * An endpoint MUST NOT bundle INIT, INIT ACK or
1432 * SHUTDOWN COMPLETE with any other chunks.
1433 *
1434 * IG Section 2.11.2
1435 * Furthermore, we require that the receiver of an INIT chunk MUST
1436 * enforce these rules by silently discarding an arriving packet
1437 * with an INIT chunk that is bundled with other chunks.
1438 */
1439 if (!chunk->singleton)
24cb81a6 1440 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
1441
1442 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
d808ad9a 1443 * Tag.
1da177e4
LT
1444 */
1445 if (chunk->sctp_hdr->vtag != 0)
24cb81a6 1446 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
1da177e4
LT
1447
1448 /* Make sure that the INIT chunk has a valid length.
1449 * In this case, we generate a protocol violation since we have
1450 * an association established.
1451 */
1452 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
24cb81a6 1453 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4
LT
1454 commands);
1455 /* Grab the INIT header. */
1456 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
1457
1458 /* Tag the variable length parameters. */
1459 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
1460
1461 /* Verify the INIT chunk before processing it. */
1462 err_chunk = NULL;
b14878cc 1463 if (!sctp_verify_init(net, ep, asoc, chunk->chunk_hdr->type,
1da177e4
LT
1464 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
1465 &err_chunk)) {
1466 /* This chunk contains fatal error. It is to be discarded.
1467 * Send an ABORT, with causes if there is any.
1468 */
1469 if (err_chunk) {
24cb81a6 1470 packet = sctp_abort_pkt_new(net, ep, asoc, arg,
1da177e4
LT
1471 (__u8 *)(err_chunk->chunk_hdr) +
1472 sizeof(sctp_chunkhdr_t),
1473 ntohs(err_chunk->chunk_hdr->length) -
1474 sizeof(sctp_chunkhdr_t));
1475
1476 if (packet) {
1477 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
1478 SCTP_PACKET(packet));
24cb81a6 1479 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
1da177e4
LT
1480 retval = SCTP_DISPOSITION_CONSUME;
1481 } else {
1482 retval = SCTP_DISPOSITION_NOMEM;
1483 }
1484 goto cleanup;
1485 } else {
24cb81a6 1486 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg,
1da177e4
LT
1487 commands);
1488 }
1489 }
1490
1491 /*
1492 * Other parameters for the endpoint SHOULD be copied from the
1493 * existing parameters of the association (e.g. number of
1494 * outbound streams) into the INIT ACK and cookie.
1495 * FIXME: We are copying parameters from the endpoint not the
1496 * association.
1497 */
1498 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
1499 if (!new_asoc)
1500 goto nomem;
1501
409b95af
VY
1502 if (sctp_assoc_set_bind_addr_from_ep(new_asoc,
1503 sctp_scope(sctp_source(chunk)), GFP_ATOMIC) < 0)
1504 goto nomem;
1505
1da177e4
LT
1506 /* In the outbound INIT ACK the endpoint MUST copy its current
1507 * Verification Tag and Peers Verification tag into a reserved
1508 * place (local tie-tag and per tie-tag) within the state cookie.
1509 */
de6becdc 1510 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk),
1da177e4 1511 (sctp_init_chunk_t *)chunk->chunk_hdr,
df7deeb5
VY
1512 GFP_ATOMIC))
1513 goto nomem;
1da177e4
LT
1514
1515 /* Make sure no new addresses are being added during the
1516 * restart. Do not do this check for COOKIE-WAIT state,
1517 * since there are no peer addresses to check against.
1518 * Upon return an ABORT will have been sent if needed.
1519 */
1520 if (!sctp_state(asoc, COOKIE_WAIT)) {
1521 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk,
1522 commands)) {
1523 retval = SCTP_DISPOSITION_CONSUME;
df7deeb5 1524 goto nomem_retval;
1da177e4
LT
1525 }
1526 }
1527
1528 sctp_tietags_populate(new_asoc, asoc);
1529
1530 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
1531
1532 /* If there are errors need to be reported for unknown parameters,
1533 * make sure to reserve enough room in the INIT ACK for them.
1534 */
1535 len = 0;
1536 if (err_chunk) {
1537 len = ntohs(err_chunk->chunk_hdr->length) -
1538 sizeof(sctp_chunkhdr_t);
1539 }
1540
1da177e4
LT
1541 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
1542 if (!repl)
1543 goto nomem;
1544
1545 /* If there are errors need to be reported for unknown parameters,
1546 * include them in the outgoing INIT ACK as "Unrecognized parameter"
1547 * parameter.
1548 */
1549 if (err_chunk) {
1550 /* Get the "Unrecognized parameter" parameter(s) out of the
1551 * ERROR chunk generated by sctp_verify_init(). Since the
1552 * error cause code for "unknown parameter" and the
1553 * "Unrecognized parameter" type is the same, we can
1554 * construct the parameters in INIT ACK by copying the
1555 * ERROR causes over.
1556 */
1557 unk_param = (sctp_unrecognized_param_t *)
1558 ((__u8 *)(err_chunk->chunk_hdr) +
1559 sizeof(sctp_chunkhdr_t));
1560 /* Replace the cause code with the "Unrecognized parameter"
1561 * parameter type.
1562 */
1563 sctp_addto_chunk(repl, len, unk_param);
1564 }
1565
1566 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
1567 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1568
1569 /*
1570 * Note: After sending out INIT ACK with the State Cookie parameter,
1571 * "Z" MUST NOT allocate any resources for this new association.
1572 * Otherwise, "Z" will be vulnerable to resource attacks.
1573 */
1574 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
1575 retval = SCTP_DISPOSITION_CONSUME;
1576
df7deeb5
VY
1577 return retval;
1578
1579nomem:
1580 retval = SCTP_DISPOSITION_NOMEM;
1581nomem_retval:
1582 if (new_asoc)
1583 sctp_association_free(new_asoc);
1da177e4
LT
1584cleanup:
1585 if (err_chunk)
1586 sctp_chunk_free(err_chunk);
1587 return retval;
1da177e4
LT
1588}
1589
1590/*
25985edc 1591 * Handle simultaneous INIT.
1da177e4
LT
1592 * This means we started an INIT and then we got an INIT request from
1593 * our peer.
1594 *
1595 * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B)
1596 * This usually indicates an initialization collision, i.e., each
1597 * endpoint is attempting, at about the same time, to establish an
1598 * association with the other endpoint.
1599 *
1600 * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an
1601 * endpoint MUST respond with an INIT ACK using the same parameters it
1602 * sent in its original INIT chunk (including its Verification Tag,
1603 * unchanged). These original parameters are combined with those from the
1604 * newly received INIT chunk. The endpoint shall also generate a State
1605 * Cookie with the INIT ACK. The endpoint uses the parameters sent in its
1606 * INIT to calculate the State Cookie.
1607 *
1608 * After that, the endpoint MUST NOT change its state, the T1-init
1609 * timer shall be left running and the corresponding TCB MUST NOT be
1610 * destroyed. The normal procedures for handling State Cookies when
1611 * a TCB exists will resolve the duplicate INITs to a single association.
1612 *
1613 * For an endpoint that is in the COOKIE-ECHOED state it MUST populate
1614 * its Tie-Tags with the Tag information of itself and its peer (see
1615 * section 5.2.2 for a description of the Tie-Tags).
1616 *
1617 * Verification Tag: Not explicit, but an INIT can not have a valid
1618 * verification tag, so we skip the check.
1619 *
1620 * Inputs
1621 * (endpoint, asoc, chunk)
1622 *
1623 * Outputs
1624 * (asoc, reply_msg, msg_up, timers, counters)
1625 *
1626 * The return value is the disposition of the chunk.
1627 */
24cb81a6
EB
1628sctp_disposition_t sctp_sf_do_5_2_1_siminit(struct net *net,
1629 const struct sctp_endpoint *ep,
1da177e4
LT
1630 const struct sctp_association *asoc,
1631 const sctp_subtype_t type,
1632 void *arg,
1633 sctp_cmd_seq_t *commands)
1634{
1635 /* Call helper to do the real work for both simulataneous and
1636 * duplicate INIT chunk handling.
1637 */
24cb81a6 1638 return sctp_sf_do_unexpected_init(net, ep, asoc, type, arg, commands);
1da177e4
LT
1639}
1640
1641/*
1642 * Handle duplicated INIT messages. These are usually delayed
1643 * restransmissions.
1644 *
1645 * Section: 5.2.2 Unexpected INIT in States Other than CLOSED,
1646 * COOKIE-ECHOED and COOKIE-WAIT
1647 *
1648 * Unless otherwise stated, upon reception of an unexpected INIT for
1649 * this association, the endpoint shall generate an INIT ACK with a
1650 * State Cookie. In the outbound INIT ACK the endpoint MUST copy its
1651 * current Verification Tag and peer's Verification Tag into a reserved
1652 * place within the state cookie. We shall refer to these locations as
1653 * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet
1654 * containing this INIT ACK MUST carry a Verification Tag value equal to
1655 * the Initiation Tag found in the unexpected INIT. And the INIT ACK
1656 * MUST contain a new Initiation Tag (randomly generated see Section
1657 * 5.3.1). Other parameters for the endpoint SHOULD be copied from the
1658 * existing parameters of the association (e.g. number of outbound
1659 * streams) into the INIT ACK and cookie.
1660 *
1661 * After sending out the INIT ACK, the endpoint shall take no further
1662 * actions, i.e., the existing association, including its current state,
1663 * and the corresponding TCB MUST NOT be changed.
1664 *
1665 * Note: Only when a TCB exists and the association is not in a COOKIE-
1666 * WAIT state are the Tie-Tags populated. For a normal association INIT
1667 * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be
1668 * set to 0 (indicating that no previous TCB existed). The INIT ACK and
1669 * State Cookie are populated as specified in section 5.2.1.
1670 *
1671 * Verification Tag: Not specified, but an INIT has no way of knowing
1672 * what the verification tag could be, so we ignore it.
1673 *
1674 * Inputs
1675 * (endpoint, asoc, chunk)
1676 *
1677 * Outputs
1678 * (asoc, reply_msg, msg_up, timers, counters)
1679 *
1680 * The return value is the disposition of the chunk.
1681 */
24cb81a6
EB
1682sctp_disposition_t sctp_sf_do_5_2_2_dupinit(struct net *net,
1683 const struct sctp_endpoint *ep,
1da177e4
LT
1684 const struct sctp_association *asoc,
1685 const sctp_subtype_t type,
1686 void *arg,
1687 sctp_cmd_seq_t *commands)
1688{
1689 /* Call helper to do the real work for both simulataneous and
1690 * duplicate INIT chunk handling.
1691 */
24cb81a6 1692 return sctp_sf_do_unexpected_init(net, ep, asoc, type, arg, commands);
1da177e4
LT
1693}
1694
1695
610ab73a
VY
1696/*
1697 * Unexpected INIT-ACK handler.
1698 *
1699 * Section 5.2.3
1700 * If an INIT ACK received by an endpoint in any state other than the
1701 * COOKIE-WAIT state, the endpoint should discard the INIT ACK chunk.
1702 * An unexpected INIT ACK usually indicates the processing of an old or
1703 * duplicated INIT chunk.
1704*/
24cb81a6
EB
1705sctp_disposition_t sctp_sf_do_5_2_3_initack(struct net *net,
1706 const struct sctp_endpoint *ep,
610ab73a
VY
1707 const struct sctp_association *asoc,
1708 const sctp_subtype_t type,
1709 void *arg, sctp_cmd_seq_t *commands)
1710{
1711 /* Per the above section, we'll discard the chunk if we have an
1712 * endpoint. If this is an OOTB INIT-ACK, treat it as such.
1713 */
2ce95503 1714 if (ep == sctp_sk(net->sctp.ctl_sock)->ep)
24cb81a6 1715 return sctp_sf_ootb(net, ep, asoc, type, arg, commands);
610ab73a 1716 else
24cb81a6 1717 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
610ab73a 1718}
1da177e4
LT
1719
1720/* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A')
1721 *
1722 * Section 5.2.4
1723 * A) In this case, the peer may have restarted.
1724 */
24cb81a6
EB
1725static sctp_disposition_t sctp_sf_do_dupcook_a(struct net *net,
1726 const struct sctp_endpoint *ep,
1da177e4
LT
1727 const struct sctp_association *asoc,
1728 struct sctp_chunk *chunk,
1729 sctp_cmd_seq_t *commands,
1730 struct sctp_association *new_asoc)
1731{
1732 sctp_init_chunk_t *peer_init;
1733 struct sctp_ulpevent *ev;
1734 struct sctp_chunk *repl;
1735 struct sctp_chunk *err;
1736 sctp_disposition_t disposition;
1737
1738 /* new_asoc is a brand-new association, so these are not yet
1739 * side effects--it is safe to run them here.
1740 */
1741 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1742
de6becdc 1743 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), peer_init,
1da177e4
LT
1744 GFP_ATOMIC))
1745 goto nomem;
1746
1747 /* Make sure no new addresses are being added during the
1748 * restart. Though this is a pretty complicated attack
1749 * since you'd have to get inside the cookie.
1750 */
1751 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk, commands)) {
1752 return SCTP_DISPOSITION_CONSUME;
1753 }
1754
1755 /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes
1756 * the peer has restarted (Action A), it MUST NOT setup a new
1757 * association but instead resend the SHUTDOWN ACK and send an ERROR
1758 * chunk with a "Cookie Received while Shutting Down" error cause to
1759 * its peer.
1760 */
1761 if (sctp_state(asoc, SHUTDOWN_ACK_SENT)) {
24cb81a6 1762 disposition = sctp_sf_do_9_2_reshutack(net, ep, asoc,
1da177e4
LT
1763 SCTP_ST_CHUNK(chunk->chunk_hdr->type),
1764 chunk, commands);
1765 if (SCTP_DISPOSITION_NOMEM == disposition)
1766 goto nomem;
1767
1768 err = sctp_make_op_error(asoc, chunk,
1769 SCTP_ERROR_COOKIE_IN_SHUTDOWN,
6383cfb3 1770 NULL, 0, 0);
1da177e4
LT
1771 if (err)
1772 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1773 SCTP_CHUNK(err));
1774
1775 return SCTP_DISPOSITION_CONSUME;
1776 }
1777
a000c01e
WY
1778 /* For now, stop pending T3-rtx and SACK timers, fail any unsent/unacked
1779 * data. Consider the optional choice of resending of this data.
1da177e4 1780 */
a000c01e
WY
1781 sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
1782 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1783 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK));
1da177e4
LT
1784 sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_OUTQUEUE, SCTP_NULL());
1785
a000c01e
WY
1786 /* Stop pending T4-rto timer, teardown ASCONF queue, ASCONF-ACK queue
1787 * and ASCONF-ACK cache.
1788 */
1789 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1790 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
1791 sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_ASCONF_QUEUE, SCTP_NULL());
1792
1da177e4
LT
1793 repl = sctp_make_cookie_ack(new_asoc, chunk);
1794 if (!repl)
1795 goto nomem;
1796
1da177e4
LT
1797 /* Report association restart to upper layer. */
1798 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_RESTART, 0,
1799 new_asoc->c.sinit_num_ostreams,
1800 new_asoc->c.sinit_max_instreams,
a5a35e76 1801 NULL, GFP_ATOMIC);
1da177e4
LT
1802 if (!ev)
1803 goto nomem_ev;
1804
df7deeb5
VY
1805 /* Update the content of current association. */
1806 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1da177e4 1807 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
bdf6fa52
VY
1808 if (sctp_state(asoc, SHUTDOWN_PENDING) &&
1809 (sctp_sstate(asoc->base.sk, CLOSING) ||
1810 sock_flag(asoc->base.sk, SOCK_DEAD))) {
1811 /* if were currently in SHUTDOWN_PENDING, but the socket
1812 * has been closed by user, don't transition to ESTABLISHED.
1813 * Instead trigger SHUTDOWN bundled with COOKIE_ACK.
1814 */
1815 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1816 return sctp_sf_do_9_2_start_shutdown(net, ep, asoc,
1817 SCTP_ST_CHUNK(0), NULL,
1818 commands);
1819 } else {
1820 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1821 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1822 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1823 }
1da177e4
LT
1824 return SCTP_DISPOSITION_CONSUME;
1825
1826nomem_ev:
1827 sctp_chunk_free(repl);
1828nomem:
1829 return SCTP_DISPOSITION_NOMEM;
1830}
1831
1832/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B')
1833 *
1834 * Section 5.2.4
1835 * B) In this case, both sides may be attempting to start an association
1836 * at about the same time but the peer endpoint started its INIT
1837 * after responding to the local endpoint's INIT
1838 */
1839/* This case represents an initialization collision. */
24cb81a6
EB
1840static sctp_disposition_t sctp_sf_do_dupcook_b(struct net *net,
1841 const struct sctp_endpoint *ep,
1da177e4
LT
1842 const struct sctp_association *asoc,
1843 struct sctp_chunk *chunk,
1844 sctp_cmd_seq_t *commands,
1845 struct sctp_association *new_asoc)
1846{
1847 sctp_init_chunk_t *peer_init;
1da177e4
LT
1848 struct sctp_chunk *repl;
1849
1850 /* new_asoc is a brand-new association, so these are not yet
1851 * side effects--it is safe to run them here.
1852 */
1853 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
de6becdc 1854 if (!sctp_process_init(new_asoc, chunk, sctp_source(chunk), peer_init,
1da177e4
LT
1855 GFP_ATOMIC))
1856 goto nomem;
1857
1858 /* Update the content of current association. */
1859 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1860 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1861 SCTP_STATE(SCTP_STATE_ESTABLISHED));
24cb81a6 1862 SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
1da177e4
LT
1863 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
1864
1865 repl = sctp_make_cookie_ack(new_asoc, chunk);
1866 if (!repl)
1867 goto nomem;
1868
1869 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1da177e4
LT
1870
1871 /* RFC 2960 5.1 Normal Establishment of an Association
1872 *
1873 * D) IMPLEMENTATION NOTE: An implementation may choose to
1874 * send the Communication Up notification to the SCTP user
1875 * upon reception of a valid COOKIE ECHO chunk.
07d93967
VY
1876 *
1877 * Sadly, this needs to be implemented as a side-effect, because
1878 * we are not guaranteed to have set the association id of the real
1879 * association and so these notifications need to be delayed until
1880 * the association id is allocated.
1da177e4 1881 */
1da177e4 1882
07d93967 1883 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_CHANGE, SCTP_U8(SCTP_COMM_UP));
1da177e4
LT
1884
1885 /* Sockets API Draft Section 5.3.1.6
0f3fffd8 1886 * When a peer sends a Adaptation Layer Indication parameter , SCTP
1da177e4 1887 * delivers this notification to inform the application that of the
0f3fffd8 1888 * peers requested adaptation layer.
07d93967
VY
1889 *
1890 * This also needs to be done as a side effect for the same reason as
1891 * above.
1da177e4 1892 */
07d93967
VY
1893 if (asoc->peer.adaptation_ind)
1894 sctp_add_cmd_sf(commands, SCTP_CMD_ADAPTATION_IND, SCTP_NULL());
1da177e4
LT
1895
1896 return SCTP_DISPOSITION_CONSUME;
1897
1da177e4
LT
1898nomem:
1899 return SCTP_DISPOSITION_NOMEM;
1900}
1901
1902/* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C')
1903 *
1904 * Section 5.2.4
1905 * C) In this case, the local endpoint's cookie has arrived late.
1906 * Before it arrived, the local endpoint sent an INIT and received an
1907 * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag
1908 * but a new tag of its own.
1909 */
1910/* This case represents an initialization collision. */
24cb81a6
EB
1911static sctp_disposition_t sctp_sf_do_dupcook_c(struct net *net,
1912 const struct sctp_endpoint *ep,
1da177e4
LT
1913 const struct sctp_association *asoc,
1914 struct sctp_chunk *chunk,
1915 sctp_cmd_seq_t *commands,
1916 struct sctp_association *new_asoc)
1917{
1918 /* The cookie should be silently discarded.
1919 * The endpoint SHOULD NOT change states and should leave
1920 * any timers running.
1921 */
1922 return SCTP_DISPOSITION_DISCARD;
1923}
1924
1925/* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D')
1926 *
1927 * Section 5.2.4
1928 *
1929 * D) When both local and remote tags match the endpoint should always
1930 * enter the ESTABLISHED state, if it has not already done so.
1931 */
1932/* This case represents an initialization collision. */
24cb81a6
EB
1933static sctp_disposition_t sctp_sf_do_dupcook_d(struct net *net,
1934 const struct sctp_endpoint *ep,
1da177e4
LT
1935 const struct sctp_association *asoc,
1936 struct sctp_chunk *chunk,
1937 sctp_cmd_seq_t *commands,
1938 struct sctp_association *new_asoc)
1939{
df7deeb5 1940 struct sctp_ulpevent *ev = NULL, *ai_ev = NULL;
1da177e4
LT
1941 struct sctp_chunk *repl;
1942
1943 /* Clarification from Implementor's Guide:
1944 * D) When both local and remote tags match the endpoint should
d808ad9a
YH
1945 * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state.
1946 * It should stop any cookie timer that may be running and send
1947 * a COOKIE ACK.
1da177e4
LT
1948 */
1949
1950 /* Don't accidentally move back into established state. */
1951 if (asoc->state < SCTP_STATE_ESTABLISHED) {
1952 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1953 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1954 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1955 SCTP_STATE(SCTP_STATE_ESTABLISHED));
24cb81a6 1956 SCTP_INC_STATS(net, SCTP_MIB_CURRESTAB);
1da177e4
LT
1957 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START,
1958 SCTP_NULL());
1959
1960 /* RFC 2960 5.1 Normal Establishment of an Association
1961 *
1962 * D) IMPLEMENTATION NOTE: An implementation may choose
1963 * to send the Communication Up notification to the
1964 * SCTP user upon reception of a valid COOKIE
1965 * ECHO chunk.
1966 */
df7deeb5 1967 ev = sctp_ulpevent_make_assoc_change(asoc, 0,
1da177e4 1968 SCTP_COMM_UP, 0,
df7deeb5
VY
1969 asoc->c.sinit_num_ostreams,
1970 asoc->c.sinit_max_instreams,
9cbcbf4e 1971 NULL, GFP_ATOMIC);
1da177e4
LT
1972 if (!ev)
1973 goto nomem;
1da177e4
LT
1974
1975 /* Sockets API Draft Section 5.3.1.6
0f3fffd8 1976 * When a peer sends a Adaptation Layer Indication parameter,
1da177e4 1977 * SCTP delivers this notification to inform the application
0f3fffd8 1978 * that of the peers requested adaptation layer.
1da177e4 1979 */
0f3fffd8
ISJ
1980 if (asoc->peer.adaptation_ind) {
1981 ai_ev = sctp_ulpevent_make_adaptation_indication(asoc,
1da177e4 1982 GFP_ATOMIC);
df7deeb5 1983 if (!ai_ev)
1da177e4
LT
1984 goto nomem;
1985
1da177e4
LT
1986 }
1987 }
1da177e4
LT
1988
1989 repl = sctp_make_cookie_ack(new_asoc, chunk);
1990 if (!repl)
1991 goto nomem;
1992
2e3216cd
VY
1993 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1994
df7deeb5
VY
1995 if (ev)
1996 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1997 SCTP_ULPEVENT(ev));
1998 if (ai_ev)
1999 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
2000 SCTP_ULPEVENT(ai_ev));
2001
1da177e4
LT
2002 return SCTP_DISPOSITION_CONSUME;
2003
2004nomem:
df7deeb5
VY
2005 if (ai_ev)
2006 sctp_ulpevent_free(ai_ev);
1da177e4
LT
2007 if (ev)
2008 sctp_ulpevent_free(ev);
2009 return SCTP_DISPOSITION_NOMEM;
2010}
2011
2012/*
2013 * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying
2014 * chunk was retransmitted and then delayed in the network.
2015 *
2016 * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists
2017 *
2018 * Verification Tag: None. Do cookie validation.
2019 *
2020 * Inputs
2021 * (endpoint, asoc, chunk)
2022 *
2023 * Outputs
2024 * (asoc, reply_msg, msg_up, timers, counters)
2025 *
2026 * The return value is the disposition of the chunk.
2027 */
24cb81a6
EB
2028sctp_disposition_t sctp_sf_do_5_2_4_dupcook(struct net *net,
2029 const struct sctp_endpoint *ep,
1da177e4
LT
2030 const struct sctp_association *asoc,
2031 const sctp_subtype_t type,
2032 void *arg,
2033 sctp_cmd_seq_t *commands)
2034{
2035 sctp_disposition_t retval;
2036 struct sctp_chunk *chunk = arg;
2037 struct sctp_association *new_asoc;
2038 int error = 0;
2039 char action;
2040 struct sctp_chunk *err_chk_p;
2041
2042 /* Make sure that the chunk has a valid length from the protocol
2043 * perspective. In this case check to make sure we have at least
2044 * enough for the chunk header. Cookie length verification is
2045 * done later.
2046 */
2047 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
24cb81a6 2048 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4
LT
2049 commands);
2050
2051 /* "Decode" the chunk. We have no optional parameters so we
2052 * are in good shape.
2053 */
d808ad9a 2054 chunk->subh.cookie_hdr = (struct sctp_signed_cookie *)chunk->skb->data;
62b08083
SS
2055 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
2056 sizeof(sctp_chunkhdr_t)))
2057 goto nomem;
1da177e4
LT
2058
2059 /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
2060 * of a duplicate COOKIE ECHO match the Verification Tags of the
2061 * current association, consider the State Cookie valid even if
2062 * the lifespan is exceeded.
2063 */
2064 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
2065 &err_chk_p);
2066
2067 /* FIXME:
2068 * If the re-build failed, what is the proper error path
2069 * from here?
2070 *
2071 * [We should abort the association. --piggy]
2072 */
2073 if (!new_asoc) {
2074 /* FIXME: Several errors are possible. A bad cookie should
2075 * be silently discarded, but think about logging it too.
2076 */
2077 switch (error) {
2078 case -SCTP_IERROR_NOMEM:
2079 goto nomem;
2080
2081 case -SCTP_IERROR_STALE_COOKIE:
24cb81a6 2082 sctp_send_stale_cookie_err(net, ep, asoc, chunk, commands,
1da177e4 2083 err_chk_p);
24cb81a6 2084 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
2085 case -SCTP_IERROR_BAD_SIG:
2086 default:
24cb81a6 2087 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3ff50b79 2088 }
1da177e4
LT
2089 }
2090
2091 /* Compare the tie_tag in cookie with the verification tag of
2092 * current association.
2093 */
2094 action = sctp_tietags_compare(new_asoc, asoc);
2095
2096 switch (action) {
2097 case 'A': /* Association restart. */
24cb81a6 2098 retval = sctp_sf_do_dupcook_a(net, ep, asoc, chunk, commands,
1da177e4
LT
2099 new_asoc);
2100 break;
2101
2102 case 'B': /* Collision case B. */
24cb81a6 2103 retval = sctp_sf_do_dupcook_b(net, ep, asoc, chunk, commands,
1da177e4
LT
2104 new_asoc);
2105 break;
2106
2107 case 'C': /* Collision case C. */
24cb81a6 2108 retval = sctp_sf_do_dupcook_c(net, ep, asoc, chunk, commands,
1da177e4
LT
2109 new_asoc);
2110 break;
2111
2112 case 'D': /* Collision case D. */
24cb81a6 2113 retval = sctp_sf_do_dupcook_d(net, ep, asoc, chunk, commands,
1da177e4
LT
2114 new_asoc);
2115 break;
2116
2117 default: /* Discard packet for all others. */
24cb81a6 2118 retval = sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4 2119 break;
3ff50b79 2120 }
1da177e4
LT
2121
2122 /* Delete the tempory new association. */
f2815633 2123 sctp_add_cmd_sf(commands, SCTP_CMD_SET_ASOC, SCTP_ASOC(new_asoc));
1da177e4
LT
2124 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
2125
d5ccd496
MM
2126 /* Restore association pointer to provide SCTP command interpeter
2127 * with a valid context in case it needs to manipulate
2128 * the queues */
2129 sctp_add_cmd_sf(commands, SCTP_CMD_SET_ASOC,
2130 SCTP_ASOC((struct sctp_association *)asoc));
2131
1da177e4
LT
2132 return retval;
2133
2134nomem:
2135 return SCTP_DISPOSITION_NOMEM;
2136}
2137
2138/*
2139 * Process an ABORT. (SHUTDOWN-PENDING state)
2140 *
2141 * See sctp_sf_do_9_1_abort().
2142 */
2143sctp_disposition_t sctp_sf_shutdown_pending_abort(
24cb81a6 2144 struct net *net,
1da177e4
LT
2145 const struct sctp_endpoint *ep,
2146 const struct sctp_association *asoc,
2147 const sctp_subtype_t type,
2148 void *arg,
2149 sctp_cmd_seq_t *commands)
2150{
2151 struct sctp_chunk *chunk = arg;
2152
2153 if (!sctp_vtag_verify_either(chunk, asoc))
24cb81a6 2154 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
2155
2156 /* Make sure that the ABORT chunk has a valid length.
2157 * Since this is an ABORT chunk, we have to discard it
2158 * because of the following text:
2159 * RFC 2960, Section 3.3.7
2160 * If an endpoint receives an ABORT with a format error or for an
2161 * association that doesn't exist, it MUST silently discard it.
25985edc 2162 * Because the length is "invalid", we can't really discard just
1da177e4
LT
2163 * as we do not know its true length. So, to be safe, discard the
2164 * packet.
2165 */
2166 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
24cb81a6 2167 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4 2168
75205f47
VY
2169 /* ADD-IP: Special case for ABORT chunks
2170 * F4) One special consideration is that ABORT Chunks arriving
2171 * destined to the IP address being deleted MUST be
2172 * ignored (see Section 5.3.1 for further details).
2173 */
2174 if (SCTP_ADDR_DEL ==
2175 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
24cb81a6 2176 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
75205f47 2177
24cb81a6 2178 return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands);
1da177e4
LT
2179}
2180
2181/*
2182 * Process an ABORT. (SHUTDOWN-SENT state)
2183 *
2184 * See sctp_sf_do_9_1_abort().
2185 */
24cb81a6
EB
2186sctp_disposition_t sctp_sf_shutdown_sent_abort(struct net *net,
2187 const struct sctp_endpoint *ep,
1da177e4
LT
2188 const struct sctp_association *asoc,
2189 const sctp_subtype_t type,
2190 void *arg,
2191 sctp_cmd_seq_t *commands)
2192{
2193 struct sctp_chunk *chunk = arg;
2194
2195 if (!sctp_vtag_verify_either(chunk, asoc))
24cb81a6 2196 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
2197
2198 /* Make sure that the ABORT chunk has a valid length.
2199 * Since this is an ABORT chunk, we have to discard it
2200 * because of the following text:
2201 * RFC 2960, Section 3.3.7
2202 * If an endpoint receives an ABORT with a format error or for an
2203 * association that doesn't exist, it MUST silently discard it.
25985edc 2204 * Because the length is "invalid", we can't really discard just
1da177e4
LT
2205 * as we do not know its true length. So, to be safe, discard the
2206 * packet.
2207 */
2208 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
24cb81a6 2209 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4 2210
75205f47
VY
2211 /* ADD-IP: Special case for ABORT chunks
2212 * F4) One special consideration is that ABORT Chunks arriving
2213 * destined to the IP address being deleted MUST be
2214 * ignored (see Section 5.3.1 for further details).
2215 */
2216 if (SCTP_ADDR_DEL ==
2217 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
24cb81a6 2218 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
75205f47 2219
1da177e4
LT
2220 /* Stop the T2-shutdown timer. */
2221 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2222 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2223
2224 /* Stop the T5-shutdown guard timer. */
2225 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2226 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
2227
24cb81a6 2228 return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands);
1da177e4
LT
2229}
2230
2231/*
2232 * Process an ABORT. (SHUTDOWN-ACK-SENT state)
2233 *
2234 * See sctp_sf_do_9_1_abort().
2235 */
2236sctp_disposition_t sctp_sf_shutdown_ack_sent_abort(
24cb81a6 2237 struct net *net,
1da177e4
LT
2238 const struct sctp_endpoint *ep,
2239 const struct sctp_association *asoc,
2240 const sctp_subtype_t type,
2241 void *arg,
2242 sctp_cmd_seq_t *commands)
2243{
2244 /* The same T2 timer, so we should be able to use
2245 * common function with the SHUTDOWN-SENT state.
2246 */
24cb81a6 2247 return sctp_sf_shutdown_sent_abort(net, ep, asoc, type, arg, commands);
1da177e4
LT
2248}
2249
2250/*
2251 * Handle an Error received in COOKIE_ECHOED state.
2252 *
2253 * Only handle the error type of stale COOKIE Error, the other errors will
2254 * be ignored.
2255 *
2256 * Inputs
2257 * (endpoint, asoc, chunk)
2258 *
2259 * Outputs
2260 * (asoc, reply_msg, msg_up, timers, counters)
2261 *
2262 * The return value is the disposition of the chunk.
2263 */
24cb81a6
EB
2264sctp_disposition_t sctp_sf_cookie_echoed_err(struct net *net,
2265 const struct sctp_endpoint *ep,
1da177e4
LT
2266 const struct sctp_association *asoc,
2267 const sctp_subtype_t type,
2268 void *arg,
2269 sctp_cmd_seq_t *commands)
2270{
2271 struct sctp_chunk *chunk = arg;
2272 sctp_errhdr_t *err;
2273
2274 if (!sctp_vtag_verify(chunk, asoc))
24cb81a6 2275 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
2276
2277 /* Make sure that the ERROR chunk has a valid length.
2278 * The parameter walking depends on this as well.
2279 */
2280 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
24cb81a6 2281 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4
LT
2282 commands);
2283
2284 /* Process the error here */
2285 /* FUTURE FIXME: When PR-SCTP related and other optional
2286 * parms are emitted, this will have to change to handle multiple
2287 * errors.
2288 */
2289 sctp_walk_errors(err, chunk->chunk_hdr) {
2290 if (SCTP_ERROR_STALE_COOKIE == err->cause)
24cb81a6 2291 return sctp_sf_do_5_2_6_stale(net, ep, asoc, type,
1da177e4
LT
2292 arg, commands);
2293 }
2294
2295 /* It is possible to have malformed error causes, and that
2296 * will cause us to end the walk early. However, since
2297 * we are discarding the packet, there should be no adverse
2298 * affects.
2299 */
24cb81a6 2300 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
2301}
2302
2303/*
2304 * Handle a Stale COOKIE Error
2305 *
2306 * Section: 5.2.6 Handle Stale COOKIE Error
2307 * If the association is in the COOKIE-ECHOED state, the endpoint may elect
2308 * one of the following three alternatives.
2309 * ...
2310 * 3) Send a new INIT chunk to the endpoint, adding a Cookie
2311 * Preservative parameter requesting an extension to the lifetime of
2312 * the State Cookie. When calculating the time extension, an
2313 * implementation SHOULD use the RTT information measured based on the
2314 * previous COOKIE ECHO / ERROR exchange, and should add no more
2315 * than 1 second beyond the measured RTT, due to long State Cookie
2316 * lifetimes making the endpoint more subject to a replay attack.
2317 *
2318 * Verification Tag: Not explicit, but safe to ignore.
2319 *
2320 * Inputs
2321 * (endpoint, asoc, chunk)
2322 *
2323 * Outputs
2324 * (asoc, reply_msg, msg_up, timers, counters)
2325 *
2326 * The return value is the disposition of the chunk.
2327 */
24cb81a6
EB
2328static sctp_disposition_t sctp_sf_do_5_2_6_stale(struct net *net,
2329 const struct sctp_endpoint *ep,
1da177e4
LT
2330 const struct sctp_association *asoc,
2331 const sctp_subtype_t type,
2332 void *arg,
2333 sctp_cmd_seq_t *commands)
2334{
2335 struct sctp_chunk *chunk = arg;
3ef0a25b 2336 u32 stale;
1da177e4
LT
2337 sctp_cookie_preserve_param_t bht;
2338 sctp_errhdr_t *err;
2339 struct sctp_chunk *reply;
2340 struct sctp_bind_addr *bp;
3f7a87d2 2341 int attempts = asoc->init_err_counter + 1;
1da177e4 2342
81845c21 2343 if (attempts > asoc->max_init_attempts) {
8de8c873
SS
2344 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
2345 SCTP_ERROR(ETIMEDOUT));
1da177e4 2346 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
dc251b2b 2347 SCTP_PERR(SCTP_ERROR_STALE_COOKIE));
1da177e4
LT
2348 return SCTP_DISPOSITION_DELETE_TCB;
2349 }
2350
2351 err = (sctp_errhdr_t *)(chunk->skb->data);
2352
2353 /* When calculating the time extension, an implementation
2354 * SHOULD use the RTT information measured based on the
2355 * previous COOKIE ECHO / ERROR exchange, and should add no
2356 * more than 1 second beyond the measured RTT, due to long
2357 * State Cookie lifetimes making the endpoint more subject to
2358 * a replay attack.
2359 * Measure of Staleness's unit is usec. (1/1000000 sec)
2360 * Suggested Cookie Life-span Increment's unit is msec.
2361 * (1/1000 sec)
2362 * In general, if you use the suggested cookie life, the value
2363 * found in the field of measure of staleness should be doubled
2364 * to give ample time to retransmit the new cookie and thus
2365 * yield a higher probability of success on the reattempt.
2366 */
34bcca28 2367 stale = ntohl(*(__be32 *)((u8 *)err + sizeof(sctp_errhdr_t)));
1da177e4
LT
2368 stale = (stale * 2) / 1000;
2369
2370 bht.param_hdr.type = SCTP_PARAM_COOKIE_PRESERVATIVE;
2371 bht.param_hdr.length = htons(sizeof(bht));
2372 bht.lifespan_increment = htonl(stale);
2373
2374 /* Build that new INIT chunk. */
2375 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
2376 reply = sctp_make_init(asoc, bp, GFP_ATOMIC, sizeof(bht));
2377 if (!reply)
2378 goto nomem;
2379
2380 sctp_addto_chunk(reply, sizeof(bht), &bht);
2381
2382 /* Clear peer's init_tag cached in assoc as we are sending a new INIT */
2383 sctp_add_cmd_sf(commands, SCTP_CMD_CLEAR_INIT_TAG, SCTP_NULL());
2384
2385 /* Stop pending T3-rtx and heartbeat timers */
2386 sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
2387 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
2388
2389 /* Delete non-primary peer ip addresses since we are transitioning
2390 * back to the COOKIE-WAIT state
2391 */
2392 sctp_add_cmd_sf(commands, SCTP_CMD_DEL_NON_PRIMARY, SCTP_NULL());
2393
d808ad9a
YH
2394 /* If we've sent any data bundled with COOKIE-ECHO we will need to
2395 * resend
1da177e4 2396 */
b6157d8e 2397 sctp_add_cmd_sf(commands, SCTP_CMD_T1_RETRAN,
1da177e4
LT
2398 SCTP_TRANSPORT(asoc->peer.primary_path));
2399
2400 /* Cast away the const modifier, as we want to just
2401 * rerun it through as a sideffect.
2402 */
3f7a87d2 2403 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_INC, SCTP_NULL());
1da177e4
LT
2404
2405 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2406 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
2407 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2408 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
2409 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
2410 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
2411
2412 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2413
2414 return SCTP_DISPOSITION_CONSUME;
2415
2416nomem:
2417 return SCTP_DISPOSITION_NOMEM;
2418}
2419
2420/*
2421 * Process an ABORT.
2422 *
2423 * Section: 9.1
2424 * After checking the Verification Tag, the receiving endpoint shall
2425 * remove the association from its record, and shall report the
2426 * termination to its upper layer.
2427 *
2428 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
2429 * B) Rules for packet carrying ABORT:
2430 *
2431 * - The endpoint shall always fill in the Verification Tag field of the
2432 * outbound packet with the destination endpoint's tag value if it
2433 * is known.
2434 *
2435 * - If the ABORT is sent in response to an OOTB packet, the endpoint
2436 * MUST follow the procedure described in Section 8.4.
2437 *
2438 * - The receiver MUST accept the packet if the Verification Tag
2439 * matches either its own tag, OR the tag of its peer. Otherwise, the
2440 * receiver MUST silently discard the packet and take no further
2441 * action.
2442 *
2443 * Inputs
2444 * (endpoint, asoc, chunk)
2445 *
2446 * Outputs
2447 * (asoc, reply_msg, msg_up, timers, counters)
2448 *
2449 * The return value is the disposition of the chunk.
2450 */
24cb81a6
EB
2451sctp_disposition_t sctp_sf_do_9_1_abort(struct net *net,
2452 const struct sctp_endpoint *ep,
1da177e4
LT
2453 const struct sctp_association *asoc,
2454 const sctp_subtype_t type,
2455 void *arg,
2456 sctp_cmd_seq_t *commands)
2457{
2458 struct sctp_chunk *chunk = arg;
1da177e4
LT
2459
2460 if (!sctp_vtag_verify_either(chunk, asoc))
24cb81a6 2461 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
2462
2463 /* Make sure that the ABORT chunk has a valid length.
2464 * Since this is an ABORT chunk, we have to discard it
2465 * because of the following text:
2466 * RFC 2960, Section 3.3.7
2467 * If an endpoint receives an ABORT with a format error or for an
2468 * association that doesn't exist, it MUST silently discard it.
25985edc 2469 * Because the length is "invalid", we can't really discard just
1da177e4
LT
2470 * as we do not know its true length. So, to be safe, discard the
2471 * packet.
2472 */
2473 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
24cb81a6 2474 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4 2475
75205f47
VY
2476 /* ADD-IP: Special case for ABORT chunks
2477 * F4) One special consideration is that ABORT Chunks arriving
2478 * destined to the IP address being deleted MUST be
2479 * ignored (see Section 5.3.1 for further details).
2480 */
2481 if (SCTP_ADDR_DEL ==
2482 sctp_bind_addr_state(&asoc->base.bind_addr, &chunk->dest))
24cb81a6 2483 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
75205f47 2484
24cb81a6 2485 return __sctp_sf_do_9_1_abort(net, ep, asoc, type, arg, commands);
75205f47
VY
2486}
2487
24cb81a6
EB
2488static sctp_disposition_t __sctp_sf_do_9_1_abort(struct net *net,
2489 const struct sctp_endpoint *ep,
75205f47
VY
2490 const struct sctp_association *asoc,
2491 const sctp_subtype_t type,
2492 void *arg,
2493 sctp_cmd_seq_t *commands)
2494{
2495 struct sctp_chunk *chunk = arg;
95c96174 2496 unsigned int len;
75205f47
VY
2497 __be16 error = SCTP_ERROR_NO_ERROR;
2498
1da177e4
LT
2499 /* See if we have an error cause code in the chunk. */
2500 len = ntohs(chunk->chunk_hdr->length);
96ca468b
SW
2501 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr)) {
2502
2503 sctp_errhdr_t *err;
2504 sctp_walk_errors(err, chunk->chunk_hdr);
2505 if ((void *)err != (void *)chunk->chunk_end)
24cb81a6 2506 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
96ca468b 2507
1da177e4 2508 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
96ca468b 2509 }
1da177e4 2510
8de8c873 2511 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNRESET));
d808ad9a 2512 /* ASSOC_FAILED will DELETE_TCB. */
5be291fe 2513 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, SCTP_PERR(error));
b01a2407
EB
2514 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
2515 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
1da177e4
LT
2516
2517 return SCTP_DISPOSITION_ABORT;
2518}
2519
2520/*
2521 * Process an ABORT. (COOKIE-WAIT state)
2522 *
2523 * See sctp_sf_do_9_1_abort() above.
2524 */
24cb81a6
EB
2525sctp_disposition_t sctp_sf_cookie_wait_abort(struct net *net,
2526 const struct sctp_endpoint *ep,
1da177e4
LT
2527 const struct sctp_association *asoc,
2528 const sctp_subtype_t type,
2529 void *arg,
2530 sctp_cmd_seq_t *commands)
2531{
2532 struct sctp_chunk *chunk = arg;
95c96174 2533 unsigned int len;
f94c0198 2534 __be16 error = SCTP_ERROR_NO_ERROR;
1da177e4
LT
2535
2536 if (!sctp_vtag_verify_either(chunk, asoc))
24cb81a6 2537 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
2538
2539 /* Make sure that the ABORT chunk has a valid length.
2540 * Since this is an ABORT chunk, we have to discard it
2541 * because of the following text:
2542 * RFC 2960, Section 3.3.7
2543 * If an endpoint receives an ABORT with a format error or for an
2544 * association that doesn't exist, it MUST silently discard it.
25985edc 2545 * Because the length is "invalid", we can't really discard just
1da177e4
LT
2546 * as we do not know its true length. So, to be safe, discard the
2547 * packet.
2548 */
2549 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
24cb81a6 2550 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
2551
2552 /* See if we have an error cause code in the chunk. */
2553 len = ntohs(chunk->chunk_hdr->length);
2554 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
2555 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2556
24cb81a6 2557 return sctp_stop_t1_and_abort(net, commands, error, ECONNREFUSED, asoc,
8de8c873 2558 chunk->transport);
1da177e4
LT
2559}
2560
2561/*
2562 * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state)
2563 */
24cb81a6
EB
2564sctp_disposition_t sctp_sf_cookie_wait_icmp_abort(struct net *net,
2565 const struct sctp_endpoint *ep,
1da177e4
LT
2566 const struct sctp_association *asoc,
2567 const sctp_subtype_t type,
2568 void *arg,
2569 sctp_cmd_seq_t *commands)
2570{
24cb81a6 2571 return sctp_stop_t1_and_abort(net, commands, SCTP_ERROR_NO_ERROR,
8de8c873 2572 ENOPROTOOPT, asoc,
3f7a87d2 2573 (struct sctp_transport *)arg);
1da177e4
LT
2574}
2575
2576/*
2577 * Process an ABORT. (COOKIE-ECHOED state)
2578 */
24cb81a6
EB
2579sctp_disposition_t sctp_sf_cookie_echoed_abort(struct net *net,
2580 const struct sctp_endpoint *ep,
1da177e4
LT
2581 const struct sctp_association *asoc,
2582 const sctp_subtype_t type,
2583 void *arg,
2584 sctp_cmd_seq_t *commands)
2585{
2586 /* There is a single T1 timer, so we should be able to use
2587 * common function with the COOKIE-WAIT state.
2588 */
24cb81a6 2589 return sctp_sf_cookie_wait_abort(net, ep, asoc, type, arg, commands);
1da177e4
LT
2590}
2591
2592/*
2593 * Stop T1 timer and abort association with "INIT failed".
2594 *
2595 * This is common code called by several sctp_sf_*_abort() functions above.
2596 */
24cb81a6
EB
2597static sctp_disposition_t sctp_stop_t1_and_abort(struct net *net,
2598 sctp_cmd_seq_t *commands,
f94c0198 2599 __be16 error, int sk_err,
3f7a87d2
FF
2600 const struct sctp_association *asoc,
2601 struct sctp_transport *transport)
1da177e4 2602{
bb33381d
DB
2603 pr_debug("%s: ABORT received (INIT)\n", __func__);
2604
1da177e4
LT
2605 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2606 SCTP_STATE(SCTP_STATE_CLOSED));
24cb81a6 2607 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
1da177e4
LT
2608 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2609 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
8de8c873 2610 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(sk_err));
1da177e4
LT
2611 /* CMD_INIT_FAILED will DELETE_TCB. */
2612 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
dc251b2b 2613 SCTP_PERR(error));
bb33381d 2614
3f7a87d2 2615 return SCTP_DISPOSITION_ABORT;
1da177e4
LT
2616}
2617
2618/*
2619 * sctp_sf_do_9_2_shut
2620 *
2621 * Section: 9.2
2622 * Upon the reception of the SHUTDOWN, the peer endpoint shall
2623 * - enter the SHUTDOWN-RECEIVED state,
2624 *
2625 * - stop accepting new data from its SCTP user
2626 *
2627 * - verify, by checking the Cumulative TSN Ack field of the chunk,
2628 * that all its outstanding DATA chunks have been received by the
2629 * SHUTDOWN sender.
2630 *
2631 * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT
2632 * send a SHUTDOWN in response to a ULP request. And should discard
2633 * subsequent SHUTDOWN chunks.
2634 *
2635 * If there are still outstanding DATA chunks left, the SHUTDOWN
2636 * receiver shall continue to follow normal data transmission
2637 * procedures defined in Section 6 until all outstanding DATA chunks
2638 * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept
2639 * new data from its SCTP user.
2640 *
2641 * Verification Tag: 8.5 Verification Tag [Normal verification]
2642 *
2643 * Inputs
2644 * (endpoint, asoc, chunk)
2645 *
2646 * Outputs
2647 * (asoc, reply_msg, msg_up, timers, counters)
2648 *
2649 * The return value is the disposition of the chunk.
2650 */
24cb81a6
EB
2651sctp_disposition_t sctp_sf_do_9_2_shutdown(struct net *net,
2652 const struct sctp_endpoint *ep,
1da177e4
LT
2653 const struct sctp_association *asoc,
2654 const sctp_subtype_t type,
2655 void *arg,
2656 sctp_cmd_seq_t *commands)
2657{
2658 struct sctp_chunk *chunk = arg;
2659 sctp_shutdownhdr_t *sdh;
2660 sctp_disposition_t disposition;
2661 struct sctp_ulpevent *ev;
df10eec4 2662 __u32 ctsn;
1da177e4
LT
2663
2664 if (!sctp_vtag_verify(chunk, asoc))
24cb81a6 2665 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
2666
2667 /* Make sure that the SHUTDOWN chunk has a valid length. */
2668 if (!sctp_chunk_length_valid(chunk,
2669 sizeof(struct sctp_shutdown_chunk_t)))
24cb81a6 2670 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4
LT
2671 commands);
2672
2673 /* Convert the elaborate header. */
2674 sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
2675 skb_pull(chunk->skb, sizeof(sctp_shutdownhdr_t));
2676 chunk->subh.shutdown_hdr = sdh;
df10eec4
WY
2677 ctsn = ntohl(sdh->cum_tsn_ack);
2678
a2f36eec 2679 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
bb33381d
DB
2680 pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn,
2681 asoc->ctsn_ack_point);
2682
a2f36eec
WY
2683 return SCTP_DISPOSITION_DISCARD;
2684 }
2685
df10eec4
WY
2686 /* If Cumulative TSN Ack beyond the max tsn currently
2687 * send, terminating the association and respond to the
2688 * sender with an ABORT.
2689 */
2690 if (!TSN_lt(ctsn, asoc->next_tsn))
24cb81a6 2691 return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands);
1da177e4 2692
eb0e0076
SS
2693 /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT
2694 * When a peer sends a SHUTDOWN, SCTP delivers this notification to
2695 * inform the application that it should cease sending data.
2696 */
2697 ev = sctp_ulpevent_make_shutdown_event(asoc, 0, GFP_ATOMIC);
2698 if (!ev) {
2699 disposition = SCTP_DISPOSITION_NOMEM;
d808ad9a 2700 goto out;
eb0e0076
SS
2701 }
2702 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
2703
1da177e4
LT
2704 /* Upon the reception of the SHUTDOWN, the peer endpoint shall
2705 * - enter the SHUTDOWN-RECEIVED state,
2706 * - stop accepting new data from its SCTP user
2707 *
2708 * [This is implicit in the new state.]
2709 */
2710 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2711 SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED));
2712 disposition = SCTP_DISPOSITION_CONSUME;
2713
2714 if (sctp_outq_is_empty(&asoc->outqueue)) {
24cb81a6 2715 disposition = sctp_sf_do_9_2_shutdown_ack(net, ep, asoc, type,
1da177e4
LT
2716 arg, commands);
2717 }
2718
2719 if (SCTP_DISPOSITION_NOMEM == disposition)
2720 goto out;
2721
2722 /* - verify, by checking the Cumulative TSN Ack field of the
2723 * chunk, that all its outstanding DATA chunks have been
2724 * received by the SHUTDOWN sender.
2725 */
2726 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
2178eda8 2727 SCTP_BE32(chunk->subh.shutdown_hdr->cum_tsn_ack));
1da177e4 2728
1da177e4
LT
2729out:
2730 return disposition;
2731}
2732
2e3f92da
WY
2733/*
2734 * sctp_sf_do_9_2_shut_ctsn
2735 *
2736 * Once an endpoint has reached the SHUTDOWN-RECEIVED state,
2737 * it MUST NOT send a SHUTDOWN in response to a ULP request.
2738 * The Cumulative TSN Ack of the received SHUTDOWN chunk
2739 * MUST be processed.
2740 */
24cb81a6
EB
2741sctp_disposition_t sctp_sf_do_9_2_shut_ctsn(struct net *net,
2742 const struct sctp_endpoint *ep,
2e3f92da
WY
2743 const struct sctp_association *asoc,
2744 const sctp_subtype_t type,
2745 void *arg,
2746 sctp_cmd_seq_t *commands)
2747{
2748 struct sctp_chunk *chunk = arg;
2749 sctp_shutdownhdr_t *sdh;
a2f36eec 2750 __u32 ctsn;
2e3f92da
WY
2751
2752 if (!sctp_vtag_verify(chunk, asoc))
24cb81a6 2753 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
2e3f92da
WY
2754
2755 /* Make sure that the SHUTDOWN chunk has a valid length. */
2756 if (!sctp_chunk_length_valid(chunk,
2757 sizeof(struct sctp_shutdown_chunk_t)))
24cb81a6 2758 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
2e3f92da
WY
2759 commands);
2760
2761 sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
a2f36eec
WY
2762 ctsn = ntohl(sdh->cum_tsn_ack);
2763
2764 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
bb33381d
DB
2765 pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn,
2766 asoc->ctsn_ack_point);
2767
a2f36eec
WY
2768 return SCTP_DISPOSITION_DISCARD;
2769 }
2e3f92da
WY
2770
2771 /* If Cumulative TSN Ack beyond the max tsn currently
2772 * send, terminating the association and respond to the
2773 * sender with an ABORT.
2774 */
a2f36eec 2775 if (!TSN_lt(ctsn, asoc->next_tsn))
24cb81a6 2776 return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands);
2e3f92da
WY
2777
2778 /* verify, by checking the Cumulative TSN Ack field of the
2779 * chunk, that all its outstanding DATA chunks have been
2780 * received by the SHUTDOWN sender.
2781 */
2782 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
2783 SCTP_BE32(sdh->cum_tsn_ack));
2784
2785 return SCTP_DISPOSITION_CONSUME;
2786}
2787
1da177e4
LT
2788/* RFC 2960 9.2
2789 * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk
2790 * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination
2791 * transport addresses (either in the IP addresses or in the INIT chunk)
2792 * that belong to this association, it should discard the INIT chunk and
2793 * retransmit the SHUTDOWN ACK chunk.
2794 */
24cb81a6
EB
2795sctp_disposition_t sctp_sf_do_9_2_reshutack(struct net *net,
2796 const struct sctp_endpoint *ep,
1da177e4
LT
2797 const struct sctp_association *asoc,
2798 const sctp_subtype_t type,
2799 void *arg,
2800 sctp_cmd_seq_t *commands)
2801{
2802 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
2803 struct sctp_chunk *reply;
2804
ece25dfa
VY
2805 /* Make sure that the chunk has a valid length */
2806 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
24cb81a6 2807 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
ece25dfa
VY
2808 commands);
2809
1da177e4
LT
2810 /* Since we are not going to really process this INIT, there
2811 * is no point in verifying chunk boundries. Just generate
2812 * the SHUTDOWN ACK.
2813 */
2814 reply = sctp_make_shutdown_ack(asoc, chunk);
2815 if (NULL == reply)
2816 goto nomem;
2817
2818 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
2819 * the T2-SHUTDOWN timer.
2820 */
2821 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
2822
2823 /* and restart the T2-shutdown timer. */
2824 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2825 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2826
2827 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2828
2829 return SCTP_DISPOSITION_CONSUME;
2830nomem:
2831 return SCTP_DISPOSITION_NOMEM;
2832}
2833
2834/*
2835 * sctp_sf_do_ecn_cwr
2836 *
2837 * Section: Appendix A: Explicit Congestion Notification
2838 *
2839 * CWR:
2840 *
2841 * RFC 2481 details a specific bit for a sender to send in the header of
2842 * its next outbound TCP segment to indicate to its peer that it has
2843 * reduced its congestion window. This is termed the CWR bit. For
2844 * SCTP the same indication is made by including the CWR chunk.
2845 * This chunk contains one data element, i.e. the TSN number that
2846 * was sent in the ECNE chunk. This element represents the lowest
2847 * TSN number in the datagram that was originally marked with the
2848 * CE bit.
2849 *
2850 * Verification Tag: 8.5 Verification Tag [Normal verification]
2851 * Inputs
2852 * (endpoint, asoc, chunk)
2853 *
2854 * Outputs
2855 * (asoc, reply_msg, msg_up, timers, counters)
2856 *
2857 * The return value is the disposition of the chunk.
2858 */
24cb81a6
EB
2859sctp_disposition_t sctp_sf_do_ecn_cwr(struct net *net,
2860 const struct sctp_endpoint *ep,
1da177e4
LT
2861 const struct sctp_association *asoc,
2862 const sctp_subtype_t type,
2863 void *arg,
2864 sctp_cmd_seq_t *commands)
2865{
2866 sctp_cwrhdr_t *cwr;
2867 struct sctp_chunk *chunk = arg;
34bcca28 2868 u32 lowest_tsn;
1da177e4
LT
2869
2870 if (!sctp_vtag_verify(chunk, asoc))
24cb81a6 2871 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
2872
2873 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
24cb81a6 2874 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4 2875 commands);
d808ad9a 2876
1da177e4
LT
2877 cwr = (sctp_cwrhdr_t *) chunk->skb->data;
2878 skb_pull(chunk->skb, sizeof(sctp_cwrhdr_t));
2879
34bcca28 2880 lowest_tsn = ntohl(cwr->lowest_tsn);
1da177e4
LT
2881
2882 /* Does this CWR ack the last sent congestion notification? */
34bcca28 2883 if (TSN_lte(asoc->last_ecne_tsn, lowest_tsn)) {
1da177e4
LT
2884 /* Stop sending ECNE. */
2885 sctp_add_cmd_sf(commands,
2886 SCTP_CMD_ECN_CWR,
34bcca28 2887 SCTP_U32(lowest_tsn));
1da177e4
LT
2888 }
2889 return SCTP_DISPOSITION_CONSUME;
2890}
2891
2892/*
2893 * sctp_sf_do_ecne
2894 *
2895 * Section: Appendix A: Explicit Congestion Notification
2896 *
2897 * ECN-Echo
2898 *
2899 * RFC 2481 details a specific bit for a receiver to send back in its
2900 * TCP acknowledgements to notify the sender of the Congestion
2901 * Experienced (CE) bit having arrived from the network. For SCTP this
2902 * same indication is made by including the ECNE chunk. This chunk
2903 * contains one data element, i.e. the lowest TSN associated with the IP
2904 * datagram marked with the CE bit.....
2905 *
2906 * Verification Tag: 8.5 Verification Tag [Normal verification]
2907 * Inputs
2908 * (endpoint, asoc, chunk)
2909 *
2910 * Outputs
2911 * (asoc, reply_msg, msg_up, timers, counters)
2912 *
2913 * The return value is the disposition of the chunk.
2914 */
24cb81a6
EB
2915sctp_disposition_t sctp_sf_do_ecne(struct net *net,
2916 const struct sctp_endpoint *ep,
1da177e4
LT
2917 const struct sctp_association *asoc,
2918 const sctp_subtype_t type,
2919 void *arg,
2920 sctp_cmd_seq_t *commands)
2921{
2922 sctp_ecnehdr_t *ecne;
2923 struct sctp_chunk *chunk = arg;
2924
2925 if (!sctp_vtag_verify(chunk, asoc))
24cb81a6 2926 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
2927
2928 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
24cb81a6 2929 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4
LT
2930 commands);
2931
2932 ecne = (sctp_ecnehdr_t *) chunk->skb->data;
2933 skb_pull(chunk->skb, sizeof(sctp_ecnehdr_t));
2934
2935 /* If this is a newer ECNE than the last CWR packet we sent out */
2936 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_ECNE,
2937 SCTP_U32(ntohl(ecne->lowest_tsn)));
2938
2939 return SCTP_DISPOSITION_CONSUME;
2940}
2941
2942/*
2943 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
2944 *
2945 * The SCTP endpoint MUST always acknowledge the reception of each valid
2946 * DATA chunk.
2947 *
2948 * The guidelines on delayed acknowledgement algorithm specified in
2949 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
2950 * acknowledgement SHOULD be generated for at least every second packet
2951 * (not every second DATA chunk) received, and SHOULD be generated within
2952 * 200 ms of the arrival of any unacknowledged DATA chunk. In some
2953 * situations it may be beneficial for an SCTP transmitter to be more
2954 * conservative than the algorithms detailed in this document allow.
2955 * However, an SCTP transmitter MUST NOT be more aggressive than the
2956 * following algorithms allow.
2957 *
2958 * A SCTP receiver MUST NOT generate more than one SACK for every
2959 * incoming packet, other than to update the offered window as the
2960 * receiving application consumes new data.
2961 *
2962 * Verification Tag: 8.5 Verification Tag [Normal verification]
2963 *
2964 * Inputs
2965 * (endpoint, asoc, chunk)
2966 *
2967 * Outputs
2968 * (asoc, reply_msg, msg_up, timers, counters)
2969 *
2970 * The return value is the disposition of the chunk.
2971 */
24cb81a6
EB
2972sctp_disposition_t sctp_sf_eat_data_6_2(struct net *net,
2973 const struct sctp_endpoint *ep,
1da177e4
LT
2974 const struct sctp_association *asoc,
2975 const sctp_subtype_t type,
2976 void *arg,
2977 sctp_cmd_seq_t *commands)
2978{
2979 struct sctp_chunk *chunk = arg;
6dc7694f 2980 sctp_arg_t force = SCTP_NOFORCE();
1da177e4
LT
2981 int error;
2982
2983 if (!sctp_vtag_verify(chunk, asoc)) {
2984 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
2985 SCTP_NULL());
24cb81a6 2986 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
d808ad9a 2987 }
1da177e4
LT
2988
2989 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
24cb81a6 2990 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4
LT
2991 commands);
2992
cb3f837b 2993 error = sctp_eat_data(asoc, chunk, commands);
1da177e4
LT
2994 switch (error) {
2995 case SCTP_IERROR_NO_ERROR:
2996 break;
2997 case SCTP_IERROR_HIGH_TSN:
2998 case SCTP_IERROR_BAD_STREAM:
24cb81a6 2999 SCTP_INC_STATS(net, SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
1da177e4
LT
3000 goto discard_noforce;
3001 case SCTP_IERROR_DUP_TSN:
3002 case SCTP_IERROR_IGNORE_TSN:
24cb81a6 3003 SCTP_INC_STATS(net, SCTP_MIB_IN_DATA_CHUNK_DISCARDS);
1da177e4
LT
3004 goto discard_force;
3005 case SCTP_IERROR_NO_DATA:
649621e3 3006 return SCTP_DISPOSITION_ABORT;
f1751c57 3007 case SCTP_IERROR_PROTO_VIOLATION:
24cb81a6 3008 return sctp_sf_abort_violation(net, ep, asoc, chunk, commands,
f1751c57 3009 (u8 *)chunk->subh.data_hdr, sizeof(sctp_datahdr_t));
1da177e4
LT
3010 default:
3011 BUG();
3012 }
3013
6dc7694f
WY
3014 if (chunk->chunk_hdr->flags & SCTP_DATA_SACK_IMM)
3015 force = SCTP_FORCE();
3016
9f70f46b 3017 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) {
1da177e4
LT
3018 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3019 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
3020 }
3021
3022 /* If this is the last chunk in a packet, we need to count it
3023 * toward sack generation. Note that we need to SACK every
3024 * OTHER packet containing data chunks, EVEN IF WE DISCARD
3025 * THEM. We elect to NOT generate SACK's if the chunk fails
3026 * the verification tag test.
3027 *
3028 * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
3029 *
3030 * The SCTP endpoint MUST always acknowledge the reception of
3031 * each valid DATA chunk.
3032 *
3033 * The guidelines on delayed acknowledgement algorithm
3034 * specified in Section 4.2 of [RFC2581] SHOULD be followed.
3035 * Specifically, an acknowledgement SHOULD be generated for at
3036 * least every second packet (not every second DATA chunk)
3037 * received, and SHOULD be generated within 200 ms of the
3038 * arrival of any unacknowledged DATA chunk. In some
3039 * situations it may be beneficial for an SCTP transmitter to
3040 * be more conservative than the algorithms detailed in this
3041 * document allow. However, an SCTP transmitter MUST NOT be
3042 * more aggressive than the following algorithms allow.
3043 */
52ccb8e9 3044 if (chunk->end_of_packet)
6dc7694f 3045 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force);
1da177e4 3046
1da177e4
LT
3047 return SCTP_DISPOSITION_CONSUME;
3048
3049discard_force:
3050 /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
3051 *
3052 * When a packet arrives with duplicate DATA chunk(s) and with
3053 * no new DATA chunk(s), the endpoint MUST immediately send a
3054 * SACK with no delay. If a packet arrives with duplicate
3055 * DATA chunk(s) bundled with new DATA chunks, the endpoint
3056 * MAY immediately send a SACK. Normally receipt of duplicate
3057 * DATA chunks will occur when the original SACK chunk was lost
3058 * and the peer's RTO has expired. The duplicate TSN number(s)
3059 * SHOULD be reported in the SACK as duplicate.
3060 */
3061 /* In our case, we split the MAY SACK advice up whether or not
3062 * the last chunk is a duplicate.'
3063 */
3064 if (chunk->end_of_packet)
3065 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3066 return SCTP_DISPOSITION_DISCARD;
3067
3068discard_noforce:
52ccb8e9 3069 if (chunk->end_of_packet)
6dc7694f 3070 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, force);
1da177e4 3071
1da177e4 3072 return SCTP_DISPOSITION_DISCARD;
1da177e4
LT
3073}
3074
3075/*
3076 * sctp_sf_eat_data_fast_4_4
3077 *
3078 * Section: 4 (4)
3079 * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received
3080 * DATA chunks without delay.
3081 *
3082 * Verification Tag: 8.5 Verification Tag [Normal verification]
3083 * Inputs
3084 * (endpoint, asoc, chunk)
3085 *
3086 * Outputs
3087 * (asoc, reply_msg, msg_up, timers, counters)
3088 *
3089 * The return value is the disposition of the chunk.
3090 */
24cb81a6
EB
3091sctp_disposition_t sctp_sf_eat_data_fast_4_4(struct net *net,
3092 const struct sctp_endpoint *ep,
1da177e4
LT
3093 const struct sctp_association *asoc,
3094 const sctp_subtype_t type,
3095 void *arg,
3096 sctp_cmd_seq_t *commands)
3097{
3098 struct sctp_chunk *chunk = arg;
3099 int error;
3100
3101 if (!sctp_vtag_verify(chunk, asoc)) {
3102 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3103 SCTP_NULL());
24cb81a6 3104 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
3105 }
3106
3107 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
24cb81a6 3108 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4
LT
3109 commands);
3110
cb3f837b 3111 error = sctp_eat_data(asoc, chunk, commands);
1da177e4
LT
3112 switch (error) {
3113 case SCTP_IERROR_NO_ERROR:
3114 case SCTP_IERROR_HIGH_TSN:
3115 case SCTP_IERROR_DUP_TSN:
3116 case SCTP_IERROR_IGNORE_TSN:
3117 case SCTP_IERROR_BAD_STREAM:
3118 break;
3119 case SCTP_IERROR_NO_DATA:
649621e3 3120 return SCTP_DISPOSITION_ABORT;
f1751c57 3121 case SCTP_IERROR_PROTO_VIOLATION:
24cb81a6 3122 return sctp_sf_abort_violation(net, ep, asoc, chunk, commands,
f1751c57 3123 (u8 *)chunk->subh.data_hdr, sizeof(sctp_datahdr_t));
1da177e4
LT
3124 default:
3125 BUG();
3126 }
3127
3128 /* Go a head and force a SACK, since we are shutting down. */
3129
3130 /* Implementor's Guide.
3131 *
3132 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3133 * respond to each received packet containing one or more DATA chunk(s)
3134 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3135 */
3136 if (chunk->end_of_packet) {
3137 /* We must delay the chunk creation since the cumulative
3138 * TSN has not been updated yet.
3139 */
3140 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
3141 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3142 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3143 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3144 }
3145
1da177e4
LT
3146 return SCTP_DISPOSITION_CONSUME;
3147}
3148
3149/*
3150 * Section: 6.2 Processing a Received SACK
3151 * D) Any time a SACK arrives, the endpoint performs the following:
3152 *
3153 * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point,
3154 * then drop the SACK. Since Cumulative TSN Ack is monotonically
3155 * increasing, a SACK whose Cumulative TSN Ack is less than the
3156 * Cumulative TSN Ack Point indicates an out-of-order SACK.
3157 *
3158 * ii) Set rwnd equal to the newly received a_rwnd minus the number
3159 * of bytes still outstanding after processing the Cumulative TSN Ack
3160 * and the Gap Ack Blocks.
3161 *
3162 * iii) If the SACK is missing a TSN that was previously
3163 * acknowledged via a Gap Ack Block (e.g., the data receiver
3164 * reneged on the data), then mark the corresponding DATA chunk
3165 * as available for retransmit: Mark it as missing for fast
3166 * retransmit as described in Section 7.2.4 and if no retransmit
3167 * timer is running for the destination address to which the DATA
3168 * chunk was originally transmitted, then T3-rtx is started for
3169 * that destination address.
3170 *
3171 * Verification Tag: 8.5 Verification Tag [Normal verification]
3172 *
3173 * Inputs
3174 * (endpoint, asoc, chunk)
3175 *
3176 * Outputs
3177 * (asoc, reply_msg, msg_up, timers, counters)
3178 *
3179 * The return value is the disposition of the chunk.
3180 */
24cb81a6
EB
3181sctp_disposition_t sctp_sf_eat_sack_6_2(struct net *net,
3182 const struct sctp_endpoint *ep,
1da177e4
LT
3183 const struct sctp_association *asoc,
3184 const sctp_subtype_t type,
3185 void *arg,
3186 sctp_cmd_seq_t *commands)
3187{
3188 struct sctp_chunk *chunk = arg;
3189 sctp_sackhdr_t *sackh;
3190 __u32 ctsn;
3191
3192 if (!sctp_vtag_verify(chunk, asoc))
24cb81a6 3193 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
3194
3195 /* Make sure that the SACK chunk has a valid length. */
3196 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_sack_chunk_t)))
24cb81a6 3197 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4
LT
3198 commands);
3199
3200 /* Pull the SACK chunk from the data buffer */
3201 sackh = sctp_sm_pull_sack(chunk);
3202 /* Was this a bogus SACK? */
3203 if (!sackh)
24cb81a6 3204 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
3205 chunk->subh.sack_hdr = sackh;
3206 ctsn = ntohl(sackh->cum_tsn_ack);
3207
3208 /* i) If Cumulative TSN Ack is less than the Cumulative TSN
3209 * Ack Point, then drop the SACK. Since Cumulative TSN
3210 * Ack is monotonically increasing, a SACK whose
3211 * Cumulative TSN Ack is less than the Cumulative TSN Ack
3212 * Point indicates an out-of-order SACK.
3213 */
3214 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
bb33381d
DB
3215 pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__, ctsn,
3216 asoc->ctsn_ack_point);
3217
1da177e4
LT
3218 return SCTP_DISPOSITION_DISCARD;
3219 }
3220
aecedeab
WY
3221 /* If Cumulative TSN Ack beyond the max tsn currently
3222 * send, terminating the association and respond to the
3223 * sender with an ABORT.
3224 */
3225 if (!TSN_lt(ctsn, asoc->next_tsn))
24cb81a6 3226 return sctp_sf_violation_ctsn(net, ep, asoc, type, arg, commands);
aecedeab 3227
1da177e4 3228 /* Return this SACK for further processing. */
edfee033 3229 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_CHUNK(chunk));
1da177e4
LT
3230
3231 /* Note: We do the rest of the work on the PROCESS_SACK
3232 * sideeffect.
3233 */
3234 return SCTP_DISPOSITION_CONSUME;
3235}
3236
3237/*
3238 * Generate an ABORT in response to a packet.
3239 *
047a2428 3240 * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41
1da177e4 3241 *
047a2428
JF
3242 * 8) The receiver should respond to the sender of the OOTB packet with
3243 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3244 * MUST fill in the Verification Tag field of the outbound packet
3245 * with the value found in the Verification Tag field of the OOTB
3246 * packet and set the T-bit in the Chunk Flags to indicate that the
3247 * Verification Tag is reflected. After sending this ABORT, the
3248 * receiver of the OOTB packet shall discard the OOTB packet and take
3249 * no further action.
1da177e4
LT
3250 *
3251 * Verification Tag:
3252 *
3253 * The return value is the disposition of the chunk.
3254*/
24cb81a6
EB
3255static sctp_disposition_t sctp_sf_tabort_8_4_8(struct net *net,
3256 const struct sctp_endpoint *ep,
1da177e4
LT
3257 const struct sctp_association *asoc,
3258 const sctp_subtype_t type,
3259 void *arg,
3260 sctp_cmd_seq_t *commands)
3261{
3262 struct sctp_packet *packet = NULL;
3263 struct sctp_chunk *chunk = arg;
3264 struct sctp_chunk *abort;
3265
2ce95503 3266 packet = sctp_ootb_pkt_new(net, asoc, chunk);
eab59075
MRL
3267 if (!packet)
3268 return SCTP_DISPOSITION_NOMEM;
1da177e4 3269
eab59075
MRL
3270 /* Make an ABORT. The T bit will be set if the asoc
3271 * is NULL.
3272 */
3273 abort = sctp_make_abort(asoc, chunk, 0);
3274 if (!abort) {
3275 sctp_ootb_pkt_free(packet);
3276 return SCTP_DISPOSITION_NOMEM;
3277 }
047a2428 3278
eab59075
MRL
3279 /* Reflect vtag if T-Bit is set */
3280 if (sctp_test_T_bit(abort))
3281 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
1da177e4 3282
eab59075
MRL
3283 /* Set the skb to the belonging sock for accounting. */
3284 abort->skb->sk = ep->base.sk;
1da177e4 3285
eab59075 3286 sctp_packet_append_chunk(packet, abort);
1da177e4 3287
eab59075
MRL
3288 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3289 SCTP_PACKET(packet));
1da177e4 3290
eab59075 3291 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
1da177e4 3292
eab59075
MRL
3293 sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3294 return SCTP_DISPOSITION_CONSUME;
1da177e4
LT
3295}
3296
3297/*
3298 * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR
3299 * event as ULP notification for each cause included in the chunk.
3300 *
3301 * API 5.3.1.3 - SCTP_REMOTE_ERROR
3302 *
3303 * The return value is the disposition of the chunk.
3304*/
24cb81a6
EB
3305sctp_disposition_t sctp_sf_operr_notify(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;
8a00be1c 3313 sctp_errhdr_t *err;
1da177e4
LT
3314
3315 if (!sctp_vtag_verify(chunk, asoc))
24cb81a6 3316 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
3317
3318 /* Make sure that the ERROR chunk has a valid length. */
3319 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
24cb81a6 3320 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4 3321 commands);
8a00be1c
SW
3322 sctp_walk_errors(err, chunk->chunk_hdr);
3323 if ((void *)err != (void *)chunk->chunk_end)
24cb81a6 3324 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
8a00be1c 3325 (void *)err, commands);
1da177e4 3326
3df26787
WY
3327 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_OPERR,
3328 SCTP_CHUNK(chunk));
1da177e4 3329
1da177e4 3330 return SCTP_DISPOSITION_CONSUME;
1da177e4
LT
3331}
3332
3333/*
3334 * Process an inbound SHUTDOWN ACK.
3335 *
3336 * From Section 9.2:
3337 * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3338 * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its
3339 * peer, and remove all record of the association.
3340 *
3341 * The return value is the disposition.
3342 */
24cb81a6
EB
3343sctp_disposition_t sctp_sf_do_9_2_final(struct net *net,
3344 const struct sctp_endpoint *ep,
1da177e4
LT
3345 const struct sctp_association *asoc,
3346 const sctp_subtype_t type,
3347 void *arg,
3348 sctp_cmd_seq_t *commands)
3349{
3350 struct sctp_chunk *chunk = arg;
3351 struct sctp_chunk *reply;
3352 struct sctp_ulpevent *ev;
3353
3354 if (!sctp_vtag_verify(chunk, asoc))
24cb81a6 3355 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
3356
3357 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3358 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
24cb81a6 3359 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4 3360 commands);
1da177e4
LT
3361 /* 10.2 H) SHUTDOWN COMPLETE notification
3362 *
3363 * When SCTP completes the shutdown procedures (section 9.2) this
3364 * notification is passed to the upper layer.
3365 */
3366 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
a5a35e76 3367 0, 0, 0, NULL, GFP_ATOMIC);
1da177e4
LT
3368 if (!ev)
3369 goto nomem;
3370
df7deeb5
VY
3371 /* ...send a SHUTDOWN COMPLETE chunk to its peer, */
3372 reply = sctp_make_shutdown_complete(asoc, chunk);
3373 if (!reply)
3374 goto nomem_chunk;
3375
3376 /* Do all the commands now (after allocation), so that we
3377 * have consistent state if memory allocation failes
3378 */
1da177e4
LT
3379 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
3380
3381 /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3382 * stop the T2-shutdown timer,
3383 */
3384 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3385 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3386
3387 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3388 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
3389
1da177e4
LT
3390 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3391 SCTP_STATE(SCTP_STATE_CLOSED));
b01a2407
EB
3392 SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS);
3393 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
1da177e4
LT
3394 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
3395
3396 /* ...and remove all record of the association. */
3397 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
3398 return SCTP_DISPOSITION_DELETE_TCB;
3399
df7deeb5
VY
3400nomem_chunk:
3401 sctp_ulpevent_free(ev);
1da177e4
LT
3402nomem:
3403 return SCTP_DISPOSITION_NOMEM;
3404}
3405
3406/*
047a2428
JF
3407 * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41.
3408 *
1da177e4
LT
3409 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3410 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3411 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3412 * packet must fill in the Verification Tag field of the outbound
3413 * packet with the Verification Tag received in the SHUTDOWN ACK and
047a2428
JF
3414 * set the T-bit in the Chunk Flags to indicate that the Verification
3415 * Tag is reflected.
1da177e4
LT
3416 *
3417 * 8) The receiver should respond to the sender of the OOTB packet with
3418 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3419 * MUST fill in the Verification Tag field of the outbound packet
3420 * with the value found in the Verification Tag field of the OOTB
047a2428
JF
3421 * packet and set the T-bit in the Chunk Flags to indicate that the
3422 * Verification Tag is reflected. After sending this ABORT, the
3423 * receiver of the OOTB packet shall discard the OOTB packet and take
3424 * no further action.
1da177e4 3425 */
24cb81a6
EB
3426sctp_disposition_t sctp_sf_ootb(struct net *net,
3427 const struct sctp_endpoint *ep,
1da177e4
LT
3428 const struct sctp_association *asoc,
3429 const sctp_subtype_t type,
3430 void *arg,
3431 sctp_cmd_seq_t *commands)
3432{
3433 struct sctp_chunk *chunk = arg;
3434 struct sk_buff *skb = chunk->skb;
3435 sctp_chunkhdr_t *ch;
85c5ed4e 3436 sctp_errhdr_t *err;
1da177e4
LT
3437 __u8 *ch_end;
3438 int ootb_shut_ack = 0;
85c5ed4e 3439 int ootb_cookie_ack = 0;
1da177e4 3440
b01a2407 3441 SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
1da177e4
LT
3442
3443 ch = (sctp_chunkhdr_t *) chunk->chunk_hdr;
3444 do {
ece25dfa 3445 /* Report violation if the chunk is less then minimal */
1da177e4 3446 if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t))
24cb81a6 3447 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
ece25dfa 3448 commands);
1da177e4 3449
bf911e98
MRL
3450 /* Report violation if chunk len overflows */
3451 ch_end = ((__u8 *)ch) + SCTP_PAD4(ntohs(ch->length));
3452 if (ch_end > skb_tail_pointer(skb))
3453 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3454 commands);
3455
ece25dfa
VY
3456 /* Now that we know we at least have a chunk header,
3457 * do things that are type appropriate.
3458 */
1da177e4
LT
3459 if (SCTP_CID_SHUTDOWN_ACK == ch->type)
3460 ootb_shut_ack = 1;
3461
3462 /* RFC 2960, Section 3.3.7
3463 * Moreover, under any circumstances, an endpoint that
3464 * receives an ABORT MUST NOT respond to that ABORT by
3465 * sending an ABORT of its own.
3466 */
3467 if (SCTP_CID_ABORT == ch->type)
24cb81a6 3468 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
d808ad9a 3469
85c5ed4e
SW
3470 /* RFC 8.4, 7) If the packet contains a "Stale cookie" ERROR
3471 * or a COOKIE ACK the SCTP Packet should be silently
3472 * discarded.
3473 */
3474
3475 if (SCTP_CID_COOKIE_ACK == ch->type)
3476 ootb_cookie_ack = 1;
3477
3478 if (SCTP_CID_ERROR == ch->type) {
3479 sctp_walk_errors(err, ch) {
3480 if (SCTP_ERROR_STALE_COOKIE == err->cause) {
3481 ootb_cookie_ack = 1;
3482 break;
3483 }
3484 }
3485 }
3486
1da177e4 3487 ch = (sctp_chunkhdr_t *) ch_end;
27a884dc 3488 } while (ch_end < skb_tail_pointer(skb));
1da177e4
LT
3489
3490 if (ootb_shut_ack)
24cb81a6 3491 return sctp_sf_shut_8_4_5(net, ep, asoc, type, arg, commands);
85c5ed4e 3492 else if (ootb_cookie_ack)
24cb81a6 3493 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4 3494 else
24cb81a6 3495 return sctp_sf_tabort_8_4_8(net, ep, asoc, type, arg, commands);
1da177e4
LT
3496}
3497
3498/*
3499 * Handle an "Out of the blue" SHUTDOWN ACK.
3500 *
047a2428
JF
3501 * Section: 8.4 5, sctpimpguide 2.41.
3502 *
1da177e4 3503 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
047a2428
JF
3504 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3505 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3506 * packet must fill in the Verification Tag field of the outbound
3507 * packet with the Verification Tag received in the SHUTDOWN ACK and
3508 * set the T-bit in the Chunk Flags to indicate that the Verification
3509 * Tag is reflected.
1da177e4
LT
3510 *
3511 * Inputs
3512 * (endpoint, asoc, type, arg, commands)
3513 *
3514 * Outputs
3515 * (sctp_disposition_t)
3516 *
3517 * The return value is the disposition of the chunk.
3518 */
24cb81a6
EB
3519static sctp_disposition_t sctp_sf_shut_8_4_5(struct net *net,
3520 const struct sctp_endpoint *ep,
1da177e4
LT
3521 const struct sctp_association *asoc,
3522 const sctp_subtype_t type,
3523 void *arg,
3524 sctp_cmd_seq_t *commands)
3525{
3526 struct sctp_packet *packet = NULL;
3527 struct sctp_chunk *chunk = arg;
3528 struct sctp_chunk *shut;
3529
2ce95503 3530 packet = sctp_ootb_pkt_new(net, asoc, chunk);
1ff01561
MRL
3531 if (!packet)
3532 return SCTP_DISPOSITION_NOMEM;
1da177e4 3533
1ff01561
MRL
3534 /* Make an SHUTDOWN_COMPLETE.
3535 * The T bit will be set if the asoc is NULL.
3536 */
3537 shut = sctp_make_shutdown_complete(asoc, chunk);
3538 if (!shut) {
3539 sctp_ootb_pkt_free(packet);
3540 return SCTP_DISPOSITION_NOMEM;
3541 }
047a2428 3542
1ff01561
MRL
3543 /* Reflect vtag if T-Bit is set */
3544 if (sctp_test_T_bit(shut))
3545 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
1da177e4 3546
1ff01561
MRL
3547 /* Set the skb to the belonging sock for accounting. */
3548 shut->skb->sk = ep->base.sk;
1da177e4 3549
1ff01561 3550 sctp_packet_append_chunk(packet, shut);
1da177e4 3551
1ff01561
MRL
3552 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3553 SCTP_PACKET(packet));
1da177e4 3554
1ff01561 3555 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
1da177e4 3556
1ff01561
MRL
3557 /* If the chunk length is invalid, we don't want to process
3558 * the reset of the packet.
3559 */
3560 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
24cb81a6 3561 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4 3562
1ff01561
MRL
3563 /* We need to discard the rest of the packet to prevent
3564 * potential bomming attacks from additional bundled chunks.
3565 * This is documented in SCTP Threats ID.
3566 */
3567 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
3568}
3569
3570/*
3571 * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state.
3572 *
3573 * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK
3574 * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the
3575 * procedures in section 8.4 SHOULD be followed, in other words it
3576 * should be treated as an Out Of The Blue packet.
3577 * [This means that we do NOT check the Verification Tag on these
3578 * chunks. --piggy ]
3579 *
3580 */
24cb81a6
EB
3581sctp_disposition_t sctp_sf_do_8_5_1_E_sa(struct net *net,
3582 const struct sctp_endpoint *ep,
1da177e4
LT
3583 const struct sctp_association *asoc,
3584 const sctp_subtype_t type,
3585 void *arg,
3586 sctp_cmd_seq_t *commands)
3587{
ece25dfa
VY
3588 struct sctp_chunk *chunk = arg;
3589
3590 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3591 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
24cb81a6 3592 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
ece25dfa
VY
3593 commands);
3594
1da177e4
LT
3595 /* Although we do have an association in this case, it corresponds
3596 * to a restarted association. So the packet is treated as an OOTB
3597 * packet and the state function that handles OOTB SHUTDOWN_ACK is
3598 * called with a NULL association.
3599 */
24cb81a6 3600 SCTP_INC_STATS(net, SCTP_MIB_OUTOFBLUES);
8190f89d 3601
24cb81a6 3602 return sctp_sf_shut_8_4_5(net, ep, NULL, type, arg, commands);
1da177e4
LT
3603}
3604
3605/* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */
24cb81a6
EB
3606sctp_disposition_t sctp_sf_do_asconf(struct net *net,
3607 const struct sctp_endpoint *ep,
1da177e4
LT
3608 const struct sctp_association *asoc,
3609 const sctp_subtype_t type, void *arg,
3610 sctp_cmd_seq_t *commands)
3611{
3612 struct sctp_chunk *chunk = arg;
3613 struct sctp_chunk *asconf_ack = NULL;
6f4c618d 3614 struct sctp_paramhdr *err_param = NULL;
1da177e4
LT
3615 sctp_addiphdr_t *hdr;
3616 __u32 serial;
3617
3618 if (!sctp_vtag_verify(chunk, asoc)) {
3619 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3620 SCTP_NULL());
24cb81a6 3621 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
3622 }
3623
6afd2e83
VY
3624 /* ADD-IP: Section 4.1.1
3625 * This chunk MUST be sent in an authenticated way by using
3626 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3627 * is received unauthenticated it MUST be silently discarded as
3628 * described in [I-D.ietf-tsvwg-sctp-auth].
3629 */
e1fc3b14 3630 if (!net->sctp.addip_noauth && !chunk->auth)
24cb81a6 3631 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
6afd2e83 3632
1da177e4
LT
3633 /* Make sure that the ASCONF ADDIP chunk has a valid length. */
3634 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_addip_chunk_t)))
24cb81a6 3635 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4
LT
3636 commands);
3637
3638 hdr = (sctp_addiphdr_t *)chunk->skb->data;
3639 serial = ntohl(hdr->serial);
3640
6f4c618d 3641 /* Verify the ASCONF chunk before processing it. */
9de7922b 3642 if (!sctp_verify_asconf(asoc, chunk, true, &err_param))
24cb81a6 3643 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
ba016670 3644 (void *)err_param, commands);
6f4c618d 3645
a08de64d 3646 /* ADDIP 5.2 E1) Compare the value of the serial number to the value
1da177e4 3647 * the endpoint stored in a new association variable
d808ad9a 3648 * 'Peer-Serial-Number'.
1da177e4
LT
3649 */
3650 if (serial == asoc->peer.addip_serial + 1) {
a08de64d
VY
3651 /* If this is the first instance of ASCONF in the packet,
3652 * we can clean our old ASCONF-ACKs.
3653 */
3654 if (!chunk->has_asconf)
3655 sctp_assoc_clean_asconf_ack_cache(asoc);
3656
3657 /* ADDIP 5.2 E4) When the Sequence Number matches the next one
3658 * expected, process the ASCONF as described below and after
3659 * processing the ASCONF Chunk, append an ASCONF-ACK Chunk to
3660 * the response packet and cache a copy of it (in the event it
3661 * later needs to be retransmitted).
3662 *
3663 * Essentially, do V1-V5.
1da177e4
LT
3664 */
3665 asconf_ack = sctp_process_asconf((struct sctp_association *)
3666 asoc, chunk);
3667 if (!asconf_ack)
3668 return SCTP_DISPOSITION_NOMEM;
a08de64d
VY
3669 } else if (serial < asoc->peer.addip_serial + 1) {
3670 /* ADDIP 5.2 E2)
3671 * If the value found in the Sequence Number is less than the
3672 * ('Peer- Sequence-Number' + 1), simply skip to the next
3673 * ASCONF, and include in the outbound response packet
3674 * any previously cached ASCONF-ACK response that was
3675 * sent and saved that matches the Sequence Number of the
3676 * ASCONF. Note: It is possible that no cached ASCONF-ACK
3677 * Chunk exists. This will occur when an older ASCONF
3678 * arrives out of order. In such a case, the receiver
3679 * should skip the ASCONF Chunk and not include ASCONF-ACK
3680 * Chunk for that chunk.
1da177e4 3681 */
a08de64d
VY
3682 asconf_ack = sctp_assoc_lookup_asconf_ack(asoc, hdr->serial);
3683 if (!asconf_ack)
1da177e4 3684 return SCTP_DISPOSITION_DISCARD;
31b02e15
VY
3685
3686 /* Reset the transport so that we select the correct one
3687 * this time around. This is to make sure that we don't
3688 * accidentally use a stale transport that's been removed.
3689 */
3690 asconf_ack->transport = NULL;
1da177e4 3691 } else {
a08de64d 3692 /* ADDIP 5.2 E5) Otherwise, the ASCONF Chunk is discarded since
1da177e4 3693 * it must be either a stale packet or from an attacker.
d808ad9a 3694 */
1da177e4
LT
3695 return SCTP_DISPOSITION_DISCARD;
3696 }
3697
a08de64d
VY
3698 /* ADDIP 5.2 E6) The destination address of the SCTP packet
3699 * containing the ASCONF-ACK Chunks MUST be the source address of
3700 * the SCTP packet that held the ASCONF Chunks.
3701 *
3702 * To do this properly, we'll set the destination address of the chunk
3703 * and at the transmit time, will try look up the transport to use.
3704 * Since ASCONFs may be bundled, the correct transport may not be
94e2bd68 3705 * created until we process the entire packet, thus this workaround.
1da177e4 3706 */
a08de64d 3707 asconf_ack->dest = chunk->source;
1da177e4 3708 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(asconf_ack));
6af29ccc 3709 if (asoc->new_transport) {
f7010e61 3710 sctp_sf_heartbeat(ep, asoc, type, asoc->new_transport, commands);
6af29ccc
MH
3711 ((struct sctp_association *)asoc)->new_transport = NULL;
3712 }
d808ad9a 3713
1da177e4
LT
3714 return SCTP_DISPOSITION_CONSUME;
3715}
3716
3717/*
3718 * ADDIP Section 4.3 General rules for address manipulation
3719 * When building TLV parameters for the ASCONF Chunk that will add or
3720 * delete IP addresses the D0 to D13 rules should be applied:
3721 */
24cb81a6
EB
3722sctp_disposition_t sctp_sf_do_asconf_ack(struct net *net,
3723 const struct sctp_endpoint *ep,
1da177e4 3724 const struct sctp_association *asoc,
d808ad9a 3725 const sctp_subtype_t type, void *arg,
1da177e4
LT
3726 sctp_cmd_seq_t *commands)
3727{
3728 struct sctp_chunk *asconf_ack = arg;
3729 struct sctp_chunk *last_asconf = asoc->addip_last_asconf;
3730 struct sctp_chunk *abort;
6f4c618d 3731 struct sctp_paramhdr *err_param = NULL;
1da177e4
LT
3732 sctp_addiphdr_t *addip_hdr;
3733 __u32 sent_serial, rcvd_serial;
3734
3735 if (!sctp_vtag_verify(asconf_ack, asoc)) {
3736 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3737 SCTP_NULL());
24cb81a6 3738 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
3739 }
3740
6afd2e83
VY
3741 /* ADD-IP, Section 4.1.2:
3742 * This chunk MUST be sent in an authenticated way by using
3743 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3744 * is received unauthenticated it MUST be silently discarded as
3745 * described in [I-D.ietf-tsvwg-sctp-auth].
3746 */
e1fc3b14 3747 if (!net->sctp.addip_noauth && !asconf_ack->auth)
24cb81a6 3748 return sctp_sf_discard_chunk(net, ep, asoc, type, arg, commands);
6afd2e83 3749
1da177e4
LT
3750 /* Make sure that the ADDIP chunk has a valid length. */
3751 if (!sctp_chunk_length_valid(asconf_ack, sizeof(sctp_addip_chunk_t)))
24cb81a6 3752 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4
LT
3753 commands);
3754
3755 addip_hdr = (sctp_addiphdr_t *)asconf_ack->skb->data;
3756 rcvd_serial = ntohl(addip_hdr->serial);
3757
6f4c618d 3758 /* Verify the ASCONF-ACK chunk before processing it. */
9de7922b 3759 if (!sctp_verify_asconf(asoc, asconf_ack, false, &err_param))
24cb81a6 3760 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
ba016670 3761 (void *)err_param, commands);
6f4c618d 3762
1da177e4
LT
3763 if (last_asconf) {
3764 addip_hdr = (sctp_addiphdr_t *)last_asconf->subh.addip_hdr;
3765 sent_serial = ntohl(addip_hdr->serial);
3766 } else {
3767 sent_serial = asoc->addip_serial - 1;
3768 }
3769
3770 /* D0) If an endpoint receives an ASCONF-ACK that is greater than or
3771 * equal to the next serial number to be used but no ASCONF chunk is
3772 * outstanding the endpoint MUST ABORT the association. Note that a
3773 * sequence number is greater than if it is no more than 2^^31-1
3774 * larger than the current sequence number (using serial arithmetic).
3775 */
3776 if (ADDIP_SERIAL_gte(rcvd_serial, sent_serial + 1) &&
3777 !(asoc->addip_last_asconf)) {
3778 abort = sctp_make_abort(asoc, asconf_ack,
3779 sizeof(sctp_errhdr_t));
3780 if (abort) {
00f1c2df 3781 sctp_init_cause(abort, SCTP_ERROR_ASCONF_ACK, 0);
1da177e4
LT
3782 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3783 SCTP_CHUNK(abort));
3784 }
3785 /* We are going to ABORT, so we might as well stop
3786 * processing the rest of the chunks in the packet.
3787 */
3788 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3789 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
cb3f837b 3790 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
8de8c873 3791 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
d808ad9a 3792 SCTP_ERROR(ECONNABORTED));
1da177e4 3793 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5be291fe 3794 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
b01a2407
EB
3795 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
3796 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
1da177e4
LT
3797 return SCTP_DISPOSITION_ABORT;
3798 }
3799
3800 if ((rcvd_serial == sent_serial) && asoc->addip_last_asconf) {
3801 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3802 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3803
3804 if (!sctp_process_asconf_ack((struct sctp_association *)asoc,
c0786693
VY
3805 asconf_ack)) {
3806 /* Successfully processed ASCONF_ACK. We can
3807 * release the next asconf if we have one.
3808 */
3809 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_NEXT_ASCONF,
3810 SCTP_NULL());
1da177e4 3811 return SCTP_DISPOSITION_CONSUME;
c0786693 3812 }
1da177e4
LT
3813
3814 abort = sctp_make_abort(asoc, asconf_ack,
3815 sizeof(sctp_errhdr_t));
3816 if (abort) {
00f1c2df 3817 sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, 0);
1da177e4
LT
3818 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3819 SCTP_CHUNK(abort));
3820 }
3821 /* We are going to ABORT, so we might as well stop
3822 * processing the rest of the chunks in the packet.
3823 */
cb3f837b 3824 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
8de8c873 3825 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
d808ad9a 3826 SCTP_ERROR(ECONNABORTED));
1da177e4 3827 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5be291fe 3828 SCTP_PERR(SCTP_ERROR_ASCONF_ACK));
b01a2407
EB
3829 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
3830 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
1da177e4
LT
3831 return SCTP_DISPOSITION_ABORT;
3832 }
3833
3834 return SCTP_DISPOSITION_DISCARD;
3835}
3836
2040d3d7
XL
3837/* RE-CONFIG Section 5.2 Upon reception of an RECONF Chunk. */
3838sctp_disposition_t sctp_sf_do_reconf(struct net *net,
3839 const struct sctp_endpoint *ep,
3840 const struct sctp_association *asoc,
3841 const sctp_subtype_t type, void *arg,
3842 sctp_cmd_seq_t *commands)
3843{
3844 struct sctp_paramhdr *err_param = NULL;
3845 struct sctp_chunk *chunk = arg;
3846 struct sctp_reconf_chunk *hdr;
3847 union sctp_params param;
3848
3849 if (!sctp_vtag_verify(chunk, asoc)) {
3850 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3851 SCTP_NULL());
3852 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
3853 }
3854
3855 /* Make sure that the RECONF chunk has a valid length. */
3856 if (!sctp_chunk_length_valid(chunk, sizeof(*hdr)))
3857 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
3858 commands);
3859
3860 if (!sctp_verify_reconf(asoc, chunk, &err_param))
3861 return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
3862 (void *)err_param, commands);
3863
3864 hdr = (struct sctp_reconf_chunk *)chunk->chunk_hdr;
3865 sctp_walk_params(param, hdr, params) {
3866 struct sctp_chunk *reply = NULL;
3867 struct sctp_ulpevent *ev = NULL;
3868
3869 if (param.p->type == SCTP_PARAM_RESET_OUT_REQUEST)
3870 reply = sctp_process_strreset_outreq(
3871 (struct sctp_association *)asoc, param, &ev);
3872 else if (param.p->type == SCTP_PARAM_RESET_IN_REQUEST)
3873 reply = sctp_process_strreset_inreq(
3874 (struct sctp_association *)asoc, param, &ev);
692787ce
XL
3875 else if (param.p->type == SCTP_PARAM_RESET_TSN_REQUEST)
3876 reply = sctp_process_strreset_tsnreq(
3877 (struct sctp_association *)asoc, param, &ev);
50a41591
XL
3878 else if (param.p->type == SCTP_PARAM_RESET_ADD_OUT_STREAMS)
3879 reply = sctp_process_strreset_addstrm_out(
3880 (struct sctp_association *)asoc, param, &ev);
c5c4ebb3
XL
3881 else if (param.p->type == SCTP_PARAM_RESET_ADD_IN_STREAMS)
3882 reply = sctp_process_strreset_addstrm_in(
3883 (struct sctp_association *)asoc, param, &ev);
2040d3d7
XL
3884 /* More handles for other types will be added here, by now it
3885 * just ignores other types.
3886 */
3887
3888 if (ev)
3889 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
3890 SCTP_ULPEVENT(ev));
3891
3892 if (reply)
3893 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3894 SCTP_CHUNK(reply));
3895 }
3896
3897 return SCTP_DISPOSITION_CONSUME;
3898}
3899
1da177e4
LT
3900/*
3901 * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP
3902 *
3903 * When a FORWARD TSN chunk arrives, the data receiver MUST first update
3904 * its cumulative TSN point to the value carried in the FORWARD TSN
3905 * chunk, and then MUST further advance its cumulative TSN point locally
3906 * if possible.
3907 * After the above processing, the data receiver MUST stop reporting any
3908 * missing TSNs earlier than or equal to the new cumulative TSN point.
3909 *
3910 * Verification Tag: 8.5 Verification Tag [Normal verification]
3911 *
3912 * The return value is the disposition of the chunk.
3913 */
24cb81a6
EB
3914sctp_disposition_t sctp_sf_eat_fwd_tsn(struct net *net,
3915 const struct sctp_endpoint *ep,
1da177e4
LT
3916 const struct sctp_association *asoc,
3917 const sctp_subtype_t type,
3918 void *arg,
3919 sctp_cmd_seq_t *commands)
3920{
3921 struct sctp_chunk *chunk = arg;
3922 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
9fcb95a1 3923 struct sctp_fwdtsn_skip *skip;
1da177e4
LT
3924 __u16 len;
3925 __u32 tsn;
3926
3927 if (!sctp_vtag_verify(chunk, asoc)) {
3928 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3929 SCTP_NULL());
24cb81a6 3930 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
3931 }
3932
d15c9ede
XL
3933 if (!asoc->peer.prsctp_capable)
3934 return sctp_sf_unk_chunk(net, ep, asoc, type, arg, commands);
3935
1da177e4
LT
3936 /* Make sure that the FORWARD_TSN chunk has valid length. */
3937 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
24cb81a6 3938 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4
LT
3939 commands);
3940
3941 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3942 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3943 len = ntohs(chunk->chunk_hdr->length);
3944 len -= sizeof(struct sctp_chunkhdr);
3945 skb_pull(chunk->skb, len);
3946
3947 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
bb33381d 3948 pr_debug("%s: TSN 0x%x\n", __func__, tsn);
1da177e4
LT
3949
3950 /* The TSN is too high--silently discard the chunk and count on it
3951 * getting retransmitted later.
3952 */
3953 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3954 goto discard_noforce;
3955
9fcb95a1
WY
3956 /* Silently discard the chunk if stream-id is not valid */
3957 sctp_walk_fwdtsn(skip, chunk) {
3958 if (ntohs(skip->stream) >= asoc->c.sinit_max_instreams)
3959 goto discard_noforce;
3960 }
3961
1da177e4
LT
3962 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3963 if (len > sizeof(struct sctp_fwdtsn_hdr))
d808ad9a 3964 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
1da177e4 3965 SCTP_CHUNK(chunk));
d808ad9a 3966
1da177e4 3967 /* Count this as receiving DATA. */
9f70f46b 3968 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE]) {
1da177e4
LT
3969 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3970 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
3971 }
d808ad9a 3972
1da177e4 3973 /* FIXME: For now send a SACK, but DATA processing may
d808ad9a 3974 * send another.
1da177e4
LT
3975 */
3976 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
1da177e4
LT
3977
3978 return SCTP_DISPOSITION_CONSUME;
3979
3980discard_noforce:
3981 return SCTP_DISPOSITION_DISCARD;
3982}
3983
3984sctp_disposition_t sctp_sf_eat_fwd_tsn_fast(
24cb81a6 3985 struct net *net,
1da177e4
LT
3986 const struct sctp_endpoint *ep,
3987 const struct sctp_association *asoc,
3988 const sctp_subtype_t type,
3989 void *arg,
3990 sctp_cmd_seq_t *commands)
3991{
3992 struct sctp_chunk *chunk = arg;
3993 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
9fcb95a1 3994 struct sctp_fwdtsn_skip *skip;
1da177e4
LT
3995 __u16 len;
3996 __u32 tsn;
3997
3998 if (!sctp_vtag_verify(chunk, asoc)) {
3999 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
4000 SCTP_NULL());
24cb81a6 4001 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
4002 }
4003
d15c9ede
XL
4004 if (!asoc->peer.prsctp_capable)
4005 return sctp_sf_unk_chunk(net, ep, asoc, type, arg, commands);
4006
1da177e4
LT
4007 /* Make sure that the FORWARD_TSN chunk has a valid length. */
4008 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
24cb81a6 4009 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4
LT
4010 commands);
4011
4012 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
4013 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
4014 len = ntohs(chunk->chunk_hdr->length);
4015 len -= sizeof(struct sctp_chunkhdr);
4016 skb_pull(chunk->skb, len);
4017
4018 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
bb33381d 4019 pr_debug("%s: TSN 0x%x\n", __func__, tsn);
1da177e4
LT
4020
4021 /* The TSN is too high--silently discard the chunk and count on it
4022 * getting retransmitted later.
4023 */
4024 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
4025 goto gen_shutdown;
4026
9fcb95a1
WY
4027 /* Silently discard the chunk if stream-id is not valid */
4028 sctp_walk_fwdtsn(skip, chunk) {
4029 if (ntohs(skip->stream) >= asoc->c.sinit_max_instreams)
4030 goto gen_shutdown;
4031 }
4032
1da177e4
LT
4033 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
4034 if (len > sizeof(struct sctp_fwdtsn_hdr))
d808ad9a 4035 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
1da177e4 4036 SCTP_CHUNK(chunk));
d808ad9a 4037
1da177e4
LT
4038 /* Go a head and force a SACK, since we are shutting down. */
4039gen_shutdown:
4040 /* Implementor's Guide.
4041 *
4042 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
4043 * respond to each received packet containing one or more DATA chunk(s)
4044 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
4045 */
4046 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
4047 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
4048 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
4049 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4050
d808ad9a 4051 return SCTP_DISPOSITION_CONSUME;
1da177e4
LT
4052}
4053
bbd0d598 4054/*
25985edc 4055 * SCTP-AUTH Section 6.3 Receiving authenticated chukns
bbd0d598
VY
4056 *
4057 * The receiver MUST use the HMAC algorithm indicated in the HMAC
4058 * Identifier field. If this algorithm was not specified by the
4059 * receiver in the HMAC-ALGO parameter in the INIT or INIT-ACK chunk
4060 * during association setup, the AUTH chunk and all chunks after it MUST
4061 * be discarded and an ERROR chunk SHOULD be sent with the error cause
4062 * defined in Section 4.1.
4063 *
4064 * If an endpoint with no shared key receives a Shared Key Identifier
4065 * other than 0, it MUST silently discard all authenticated chunks. If
4066 * the endpoint has at least one endpoint pair shared key for the peer,
4067 * it MUST use the key specified by the Shared Key Identifier if a
4068 * key has been configured for that Shared Key Identifier. If no
4069 * endpoint pair shared key has been configured for that Shared Key
4070 * Identifier, all authenticated chunks MUST be silently discarded.
4071 *
4072 * Verification Tag: 8.5 Verification Tag [Normal verification]
4073 *
4074 * The return value is the disposition of the chunk.
4075 */
24cb81a6
EB
4076static sctp_ierror_t sctp_sf_authenticate(struct net *net,
4077 const struct sctp_endpoint *ep,
bbd0d598
VY
4078 const struct sctp_association *asoc,
4079 const sctp_subtype_t type,
4080 struct sctp_chunk *chunk)
4081{
4082 struct sctp_authhdr *auth_hdr;
4083 struct sctp_hmac *hmac;
4084 unsigned int sig_len;
4085 __u16 key_id;
4086 __u8 *save_digest;
4087 __u8 *digest;
4088
4089 /* Pull in the auth header, so we can do some more verification */
4090 auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
4091 chunk->subh.auth_hdr = auth_hdr;
4092 skb_pull(chunk->skb, sizeof(struct sctp_authhdr));
4093
02582e9b 4094 /* Make sure that we support the HMAC algorithm from the auth
bbd0d598
VY
4095 * chunk.
4096 */
4097 if (!sctp_auth_asoc_verify_hmac_id(asoc, auth_hdr->hmac_id))
4098 return SCTP_IERROR_AUTH_BAD_HMAC;
4099
4100 /* Make sure that the provided shared key identifier has been
4101 * configured
4102 */
4103 key_id = ntohs(auth_hdr->shkey_id);
4104 if (key_id != asoc->active_key_id && !sctp_auth_get_shkey(asoc, key_id))
4105 return SCTP_IERROR_AUTH_BAD_KEYID;
4106
4107
4108 /* Make sure that the length of the signature matches what
4109 * we expect.
4110 */
4111 sig_len = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_auth_chunk_t);
4112 hmac = sctp_auth_get_hmac(ntohs(auth_hdr->hmac_id));
4113 if (sig_len != hmac->hmac_len)
4114 return SCTP_IERROR_PROTO_VIOLATION;
4115
4116 /* Now that we've done validation checks, we can compute and
4117 * verify the hmac. The steps involved are:
4118 * 1. Save the digest from the chunk.
4119 * 2. Zero out the digest in the chunk.
4120 * 3. Compute the new digest
4121 * 4. Compare saved and new digests.
4122 */
4123 digest = auth_hdr->hmac;
4124 skb_pull(chunk->skb, sig_len);
4125
4126 save_digest = kmemdup(digest, sig_len, GFP_ATOMIC);
4127 if (!save_digest)
4128 goto nomem;
4129
4130 memset(digest, 0, sig_len);
4131
4132 sctp_auth_calculate_hmac(asoc, chunk->skb,
4133 (struct sctp_auth_chunk *)chunk->chunk_hdr,
4134 GFP_ATOMIC);
4135
4136 /* Discard the packet if the digests do not match */
4137 if (memcmp(save_digest, digest, sig_len)) {
4138 kfree(save_digest);
4139 return SCTP_IERROR_BAD_SIG;
4140 }
4141
4142 kfree(save_digest);
4143 chunk->auth = 1;
4144
4145 return SCTP_IERROR_NO_ERROR;
4146nomem:
4147 return SCTP_IERROR_NOMEM;
4148}
4149
24cb81a6
EB
4150sctp_disposition_t sctp_sf_eat_auth(struct net *net,
4151 const struct sctp_endpoint *ep,
bbd0d598
VY
4152 const struct sctp_association *asoc,
4153 const sctp_subtype_t type,
4154 void *arg,
4155 sctp_cmd_seq_t *commands)
4156{
4157 struct sctp_authhdr *auth_hdr;
4158 struct sctp_chunk *chunk = arg;
4159 struct sctp_chunk *err_chunk;
4160 sctp_ierror_t error;
4161
d2f19fa1
WY
4162 /* Make sure that the peer has AUTH capable */
4163 if (!asoc->peer.auth_capable)
24cb81a6 4164 return sctp_sf_unk_chunk(net, ep, asoc, type, arg, commands);
d2f19fa1 4165
bbd0d598
VY
4166 if (!sctp_vtag_verify(chunk, asoc)) {
4167 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
4168 SCTP_NULL());
24cb81a6 4169 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
bbd0d598
VY
4170 }
4171
4172 /* Make sure that the AUTH chunk has valid length. */
4173 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_auth_chunk)))
24cb81a6 4174 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
bbd0d598
VY
4175 commands);
4176
4177 auth_hdr = (struct sctp_authhdr *)chunk->skb->data;
24cb81a6 4178 error = sctp_sf_authenticate(net, ep, asoc, type, chunk);
bbd0d598 4179 switch (error) {
7fd71b1e
JP
4180 case SCTP_IERROR_AUTH_BAD_HMAC:
4181 /* Generate the ERROR chunk and discard the rest
4182 * of the packet
4183 */
4184 err_chunk = sctp_make_op_error(asoc, chunk,
4185 SCTP_ERROR_UNSUP_HMAC,
4186 &auth_hdr->hmac_id,
4187 sizeof(__u16), 0);
4188 if (err_chunk) {
4189 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4190 SCTP_CHUNK(err_chunk));
4191 }
4192 /* Fall Through */
4193 case SCTP_IERROR_AUTH_BAD_KEYID:
4194 case SCTP_IERROR_BAD_SIG:
24cb81a6 4195 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
7fd71b1e
JP
4196
4197 case SCTP_IERROR_PROTO_VIOLATION:
24cb81a6 4198 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
7fd71b1e
JP
4199 commands);
4200
4201 case SCTP_IERROR_NOMEM:
4202 return SCTP_DISPOSITION_NOMEM;
4203
4204 default: /* Prevent gcc warnings */
4205 break;
bbd0d598
VY
4206 }
4207
65b07e5d
VY
4208 if (asoc->active_key_id != ntohs(auth_hdr->shkey_id)) {
4209 struct sctp_ulpevent *ev;
4210
4211 ev = sctp_ulpevent_make_authkey(asoc, ntohs(auth_hdr->shkey_id),
4212 SCTP_AUTH_NEWKEY, GFP_ATOMIC);
4213
4214 if (!ev)
4215 return -ENOMEM;
4216
4217 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
4218 SCTP_ULPEVENT(ev));
4219 }
4220
bbd0d598
VY
4221 return SCTP_DISPOSITION_CONSUME;
4222}
4223
1da177e4
LT
4224/*
4225 * Process an unknown chunk.
4226 *
4227 * Section: 3.2. Also, 2.1 in the implementor's guide.
4228 *
4229 * Chunk Types are encoded such that the highest-order two bits specify
4230 * the action that must be taken if the processing endpoint does not
4231 * recognize the Chunk Type.
4232 *
4233 * 00 - Stop processing this SCTP packet and discard it, do not process
4234 * any further chunks within it.
4235 *
4236 * 01 - Stop processing this SCTP packet and discard it, do not process
4237 * any further chunks within it, and report the unrecognized
4238 * chunk in an 'Unrecognized Chunk Type'.
4239 *
4240 * 10 - Skip this chunk and continue processing.
4241 *
4242 * 11 - Skip this chunk and continue processing, but report in an ERROR
4243 * Chunk using the 'Unrecognized Chunk Type' cause of error.
4244 *
4245 * The return value is the disposition of the chunk.
4246 */
24cb81a6
EB
4247sctp_disposition_t sctp_sf_unk_chunk(struct net *net,
4248 const struct sctp_endpoint *ep,
1da177e4
LT
4249 const struct sctp_association *asoc,
4250 const sctp_subtype_t type,
4251 void *arg,
4252 sctp_cmd_seq_t *commands)
4253{
4254 struct sctp_chunk *unk_chunk = arg;
4255 struct sctp_chunk *err_chunk;
4256 sctp_chunkhdr_t *hdr;
4257
bb33381d 4258 pr_debug("%s: processing unknown chunk id:%d\n", __func__, type.chunk);
1da177e4
LT
4259
4260 if (!sctp_vtag_verify(unk_chunk, asoc))
24cb81a6 4261 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
4262
4263 /* Make sure that the chunk has a valid length.
4264 * Since we don't know the chunk type, we use a general
4265 * chunkhdr structure to make a comparison.
4266 */
4267 if (!sctp_chunk_length_valid(unk_chunk, sizeof(sctp_chunkhdr_t)))
24cb81a6 4268 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4
LT
4269 commands);
4270
4271 switch (type.chunk & SCTP_CID_ACTION_MASK) {
4272 case SCTP_CID_ACTION_DISCARD:
4273 /* Discard the packet. */
24cb81a6 4274 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4 4275 case SCTP_CID_ACTION_DISCARD_ERR:
1da177e4
LT
4276 /* Generate an ERROR chunk as response. */
4277 hdr = unk_chunk->chunk_hdr;
4278 err_chunk = sctp_make_op_error(asoc, unk_chunk,
4279 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
e2f036a9 4280 SCTP_PAD4(ntohs(hdr->length)),
6383cfb3 4281 0);
1da177e4
LT
4282 if (err_chunk) {
4283 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4284 SCTP_CHUNK(err_chunk));
4285 }
2e3216cd
VY
4286
4287 /* Discard the packet. */
24cb81a6 4288 sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4 4289 return SCTP_DISPOSITION_CONSUME;
1da177e4
LT
4290 case SCTP_CID_ACTION_SKIP:
4291 /* Skip the chunk. */
4292 return SCTP_DISPOSITION_DISCARD;
1da177e4
LT
4293 case SCTP_CID_ACTION_SKIP_ERR:
4294 /* Generate an ERROR chunk as response. */
4295 hdr = unk_chunk->chunk_hdr;
4296 err_chunk = sctp_make_op_error(asoc, unk_chunk,
4297 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
e2f036a9 4298 SCTP_PAD4(ntohs(hdr->length)),
6383cfb3 4299 0);
1da177e4
LT
4300 if (err_chunk) {
4301 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4302 SCTP_CHUNK(err_chunk));
4303 }
4304 /* Skip the chunk. */
4305 return SCTP_DISPOSITION_CONSUME;
1da177e4
LT
4306 default:
4307 break;
4308 }
4309
4310 return SCTP_DISPOSITION_DISCARD;
4311}
4312
4313/*
4314 * Discard the chunk.
4315 *
4316 * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2
4317 * [Too numerous to mention...]
4318 * Verification Tag: No verification needed.
4319 * Inputs
4320 * (endpoint, asoc, chunk)
4321 *
4322 * Outputs
4323 * (asoc, reply_msg, msg_up, timers, counters)
4324 *
4325 * The return value is the disposition of the chunk.
4326 */
24cb81a6
EB
4327sctp_disposition_t sctp_sf_discard_chunk(struct net *net,
4328 const struct sctp_endpoint *ep,
1da177e4
LT
4329 const struct sctp_association *asoc,
4330 const sctp_subtype_t type,
4331 void *arg,
4332 sctp_cmd_seq_t *commands)
4333{
ece25dfa
VY
4334 struct sctp_chunk *chunk = arg;
4335
4336 /* Make sure that the chunk has a valid length.
4337 * Since we don't know the chunk type, we use a general
4338 * chunkhdr structure to make a comparison.
4339 */
4340 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
24cb81a6 4341 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
ece25dfa
VY
4342 commands);
4343
bb33381d
DB
4344 pr_debug("%s: chunk:%d is discarded\n", __func__, type.chunk);
4345
1da177e4
LT
4346 return SCTP_DISPOSITION_DISCARD;
4347}
4348
4349/*
4350 * Discard the whole packet.
4351 *
4352 * Section: 8.4 2)
4353 *
4354 * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST
4355 * silently discard the OOTB packet and take no further action.
1da177e4
LT
4356 *
4357 * Verification Tag: No verification necessary
4358 *
4359 * Inputs
4360 * (endpoint, asoc, chunk)
4361 *
4362 * Outputs
4363 * (asoc, reply_msg, msg_up, timers, counters)
4364 *
4365 * The return value is the disposition of the chunk.
4366 */
24cb81a6
EB
4367sctp_disposition_t sctp_sf_pdiscard(struct net *net,
4368 const struct sctp_endpoint *ep,
1da177e4
LT
4369 const struct sctp_association *asoc,
4370 const sctp_subtype_t type,
4371 void *arg,
4372 sctp_cmd_seq_t *commands)
4373{
24cb81a6 4374 SCTP_INC_STATS(net, SCTP_MIB_IN_PKT_DISCARDS);
1da177e4
LT
4375 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
4376
4377 return SCTP_DISPOSITION_CONSUME;
4378}
4379
4380
4381/*
4382 * The other end is violating protocol.
4383 *
4384 * Section: Not specified
4385 * Verification Tag: Not specified
4386 * Inputs
4387 * (endpoint, asoc, chunk)
4388 *
4389 * Outputs
4390 * (asoc, reply_msg, msg_up, timers, counters)
4391 *
4392 * We simply tag the chunk as a violation. The state machine will log
4393 * the violation and continue.
4394 */
24cb81a6
EB
4395sctp_disposition_t sctp_sf_violation(struct net *net,
4396 const struct sctp_endpoint *ep,
1da177e4
LT
4397 const struct sctp_association *asoc,
4398 const sctp_subtype_t type,
4399 void *arg,
4400 sctp_cmd_seq_t *commands)
4401{
ece25dfa
VY
4402 struct sctp_chunk *chunk = arg;
4403
4404 /* Make sure that the chunk has a valid length. */
4405 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
24cb81a6 4406 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
ece25dfa
VY
4407 commands);
4408
1da177e4
LT
4409 return SCTP_DISPOSITION_VIOLATION;
4410}
4411
1da177e4 4412/*
aecedeab 4413 * Common function to handle a protocol violation.
1da177e4 4414 */
aecedeab 4415static sctp_disposition_t sctp_sf_abort_violation(
24cb81a6 4416 struct net *net,
ece25dfa 4417 const struct sctp_endpoint *ep,
1da177e4 4418 const struct sctp_association *asoc,
1da177e4 4419 void *arg,
aecedeab
WY
4420 sctp_cmd_seq_t *commands,
4421 const __u8 *payload,
4422 const size_t paylen)
1da177e4 4423{
ece25dfa 4424 struct sctp_packet *packet = NULL;
1da177e4
LT
4425 struct sctp_chunk *chunk = arg;
4426 struct sctp_chunk *abort = NULL;
1da177e4 4427
bbd0d598
VY
4428 /* SCTP-AUTH, Section 6.3:
4429 * It should be noted that if the receiver wants to tear
4430 * down an association in an authenticated way only, the
4431 * handling of malformed packets should not result in
4432 * tearing down the association.
4433 *
4434 * This means that if we only want to abort associations
4435 * in an authenticated way (i.e AUTH+ABORT), then we
25985edc 4436 * can't destroy this association just because the packet
bbd0d598
VY
4437 * was malformed.
4438 */
4439 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
4440 goto discard;
4441
9abed245
JJ
4442 /* Make the abort chunk. */
4443 abort = sctp_make_abort_violation(asoc, chunk, payload, paylen);
4444 if (!abort)
4445 goto nomem;
4446
ece25dfa 4447 if (asoc) {
f4ad85ca
GJ
4448 /* Treat INIT-ACK as a special case during COOKIE-WAIT. */
4449 if (chunk->chunk_hdr->type == SCTP_CID_INIT_ACK &&
4450 !asoc->peer.i.init_tag) {
4451 sctp_initack_chunk_t *initack;
4452
4453 initack = (sctp_initack_chunk_t *)chunk->chunk_hdr;
4454 if (!sctp_chunk_length_valid(chunk,
4455 sizeof(sctp_initack_chunk_t)))
4456 abort->chunk_hdr->flags |= SCTP_CHUNK_FLAG_T;
4457 else {
4458 unsigned int inittag;
4459
4460 inittag = ntohl(initack->init_hdr.init_tag);
4461 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_INITTAG,
4462 SCTP_U32(inittag));
4463 }
4464 }
4465
ece25dfa 4466 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
b01a2407 4467 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
1da177e4 4468
ece25dfa
VY
4469 if (asoc->state <= SCTP_STATE_COOKIE_ECHOED) {
4470 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4471 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4472 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4473 SCTP_ERROR(ECONNREFUSED));
4474 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
4475 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
4476 } else {
4477 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4478 SCTP_ERROR(ECONNABORTED));
4479 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4480 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
b01a2407 4481 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
ece25dfa 4482 }
1da177e4 4483 } else {
2ce95503 4484 packet = sctp_ootb_pkt_new(net, asoc, chunk);
ece25dfa
VY
4485
4486 if (!packet)
4487 goto nomem_pkt;
4488
4489 if (sctp_test_T_bit(abort))
4490 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
4491
4492 abort->skb->sk = ep->base.sk;
4493
4494 sctp_packet_append_chunk(packet, abort);
4495
4496 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
4497 SCTP_PACKET(packet));
4498
b01a2407 4499 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
1da177e4
LT
4500 }
4501
b01a2407 4502 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
d808ad9a 4503
56eb82bb 4504discard:
24cb81a6 4505 sctp_sf_pdiscard(net, ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
1da177e4
LT
4506 return SCTP_DISPOSITION_ABORT;
4507
ece25dfa
VY
4508nomem_pkt:
4509 sctp_chunk_free(abort);
1da177e4
LT
4510nomem:
4511 return SCTP_DISPOSITION_NOMEM;
4512}
4513
aecedeab
WY
4514/*
4515 * Handle a protocol violation when the chunk length is invalid.
025dfdaf 4516 * "Invalid" length is identified as smaller than the minimal length a
aecedeab 4517 * given chunk can be. For example, a SACK chunk has invalid length
025dfdaf 4518 * if its length is set to be smaller than the size of sctp_sack_chunk_t.
aecedeab
WY
4519 *
4520 * We inform the other end by sending an ABORT with a Protocol Violation
4521 * error code.
4522 *
4523 * Section: Not specified
4524 * Verification Tag: Nothing to do
4525 * Inputs
4526 * (endpoint, asoc, chunk)
4527 *
4528 * Outputs
4529 * (reply_msg, msg_up, counters)
4530 *
4531 * Generate an ABORT chunk and terminate the association.
4532 */
4533static sctp_disposition_t sctp_sf_violation_chunklen(
24cb81a6 4534 struct net *net,
aecedeab
WY
4535 const struct sctp_endpoint *ep,
4536 const struct sctp_association *asoc,
4537 const sctp_subtype_t type,
4538 void *arg,
4539 sctp_cmd_seq_t *commands)
4540{
cb3f837b 4541 static const char err_str[] = "The following chunk had invalid length:";
aecedeab 4542
24cb81a6 4543 return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str,
aecedeab
WY
4544 sizeof(err_str));
4545}
4546
6f4c618d
WY
4547/*
4548 * Handle a protocol violation when the parameter length is invalid.
33c7cfdb
SW
4549 * If the length is smaller than the minimum length of a given parameter,
4550 * or accumulated length in multi parameters exceeds the end of the chunk,
4551 * the length is considered as invalid.
6f4c618d
WY
4552 */
4553static sctp_disposition_t sctp_sf_violation_paramlen(
24cb81a6 4554 struct net *net,
6f4c618d
WY
4555 const struct sctp_endpoint *ep,
4556 const struct sctp_association *asoc,
4557 const sctp_subtype_t type,
ba016670
WY
4558 void *arg, void *ext,
4559 sctp_cmd_seq_t *commands)
4560{
4561 struct sctp_chunk *chunk = arg;
4562 struct sctp_paramhdr *param = ext;
4563 struct sctp_chunk *abort = NULL;
6f4c618d 4564
ba016670
WY
4565 if (sctp_auth_recv_cid(SCTP_CID_ABORT, asoc))
4566 goto discard;
4567
4568 /* Make the abort chunk. */
4569 abort = sctp_make_violation_paramlen(asoc, chunk, param);
4570 if (!abort)
4571 goto nomem;
4572
4573 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
b01a2407 4574 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
ba016670
WY
4575
4576 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4577 SCTP_ERROR(ECONNABORTED));
4578 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4579 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION));
b01a2407
EB
4580 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
4581 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
ba016670
WY
4582
4583discard:
24cb81a6 4584 sctp_sf_pdiscard(net, ep, asoc, SCTP_ST_CHUNK(0), arg, commands);
ba016670
WY
4585 return SCTP_DISPOSITION_ABORT;
4586nomem:
4587 return SCTP_DISPOSITION_NOMEM;
6f4c618d
WY
4588}
4589
aecedeab
WY
4590/* Handle a protocol violation when the peer trying to advance the
4591 * cumulative tsn ack to a point beyond the max tsn currently sent.
4592 *
4593 * We inform the other end by sending an ABORT with a Protocol Violation
4594 * error code.
4595 */
4596static sctp_disposition_t sctp_sf_violation_ctsn(
24cb81a6 4597 struct net *net,
aecedeab
WY
4598 const struct sctp_endpoint *ep,
4599 const struct sctp_association *asoc,
4600 const sctp_subtype_t type,
4601 void *arg,
4602 sctp_cmd_seq_t *commands)
4603{
cb3f837b 4604 static const char err_str[] = "The cumulative tsn ack beyond the max tsn currently sent:";
aecedeab 4605
24cb81a6 4606 return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str,
aecedeab
WY
4607 sizeof(err_str));
4608}
4609
ece25dfa 4610/* Handle protocol violation of an invalid chunk bundling. For example,
25985edc 4611 * when we have an association and we receive bundled INIT-ACK, or
ece25dfa 4612 * SHUDOWN-COMPLETE, our peer is clearly violationg the "MUST NOT bundle"
25985edc 4613 * statement from the specs. Additionally, there might be an attacker
ece25dfa
VY
4614 * on the path and we may not want to continue this communication.
4615 */
4616static sctp_disposition_t sctp_sf_violation_chunk(
24cb81a6 4617 struct net *net,
ece25dfa
VY
4618 const struct sctp_endpoint *ep,
4619 const struct sctp_association *asoc,
4620 const sctp_subtype_t type,
4621 void *arg,
4622 sctp_cmd_seq_t *commands)
4623{
cb3f837b 4624 static const char err_str[] = "The following chunk violates protocol:";
ece25dfa
VY
4625
4626 if (!asoc)
24cb81a6 4627 return sctp_sf_violation(net, ep, asoc, type, arg, commands);
ece25dfa 4628
24cb81a6 4629 return sctp_sf_abort_violation(net, ep, asoc, arg, commands, err_str,
ece25dfa
VY
4630 sizeof(err_str));
4631}
1da177e4
LT
4632/***************************************************************************
4633 * These are the state functions for handling primitive (Section 10) events.
4634 ***************************************************************************/
4635/*
4636 * sctp_sf_do_prm_asoc
4637 *
4638 * Section: 10.1 ULP-to-SCTP
4639 * B) Associate
4640 *
4641 * Format: ASSOCIATE(local SCTP instance name, destination transport addr,
4642 * outbound stream count)
4643 * -> association id [,destination transport addr list] [,outbound stream
4644 * count]
4645 *
4646 * This primitive allows the upper layer to initiate an association to a
4647 * specific peer endpoint.
4648 *
4649 * The peer endpoint shall be specified by one of the transport addresses
4650 * which defines the endpoint (see Section 1.4). If the local SCTP
4651 * instance has not been initialized, the ASSOCIATE is considered an
4652 * error.
4653 * [This is not relevant for the kernel implementation since we do all
4654 * initialization at boot time. It we hadn't initialized we wouldn't
4655 * get anywhere near this code.]
4656 *
4657 * An association id, which is a local handle to the SCTP association,
4658 * will be returned on successful establishment of the association. If
4659 * SCTP is not able to open an SCTP association with the peer endpoint,
4660 * an error is returned.
4661 * [In the kernel implementation, the struct sctp_association needs to
4662 * be created BEFORE causing this primitive to run.]
4663 *
4664 * Other association parameters may be returned, including the
4665 * complete destination transport addresses of the peer as well as the
4666 * outbound stream count of the local endpoint. One of the transport
4667 * address from the returned destination addresses will be selected by
4668 * the local endpoint as default primary path for sending SCTP packets
4669 * to this peer. The returned "destination transport addr list" can
4670 * be used by the ULP to change the default primary path or to force
4671 * sending a packet to a specific transport address. [All of this
4672 * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING
4673 * function.]
4674 *
4675 * Mandatory attributes:
4676 *
4677 * o local SCTP instance name - obtained from the INITIALIZE operation.
4678 * [This is the argument asoc.]
4679 * o destination transport addr - specified as one of the transport
4680 * addresses of the peer endpoint with which the association is to be
4681 * established.
4682 * [This is asoc->peer.active_path.]
4683 * o outbound stream count - the number of outbound streams the ULP
4684 * would like to open towards this peer endpoint.
4685 * [BUG: This is not currently implemented.]
4686 * Optional attributes:
4687 *
4688 * None.
4689 *
4690 * The return value is a disposition.
4691 */
24cb81a6
EB
4692sctp_disposition_t sctp_sf_do_prm_asoc(struct net *net,
4693 const struct sctp_endpoint *ep,
1da177e4
LT
4694 const struct sctp_association *asoc,
4695 const sctp_subtype_t type,
4696 void *arg,
4697 sctp_cmd_seq_t *commands)
4698{
4699 struct sctp_chunk *repl;
26ac8e5f 4700 struct sctp_association *my_asoc;
1da177e4
LT
4701
4702 /* The comment below says that we enter COOKIE-WAIT AFTER
4703 * sending the INIT, but that doesn't actually work in our
4704 * implementation...
4705 */
4706 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4707 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
4708
4709 /* RFC 2960 5.1 Normal Establishment of an Association
4710 *
4711 * A) "A" first sends an INIT chunk to "Z". In the INIT, "A"
4712 * must provide its Verification Tag (Tag_A) in the Initiate
4713 * Tag field. Tag_A SHOULD be a random number in the range of
4714 * 1 to 4294967295 (see 5.3.1 for Tag value selection). ...
4715 */
4716
4717 repl = sctp_make_init(asoc, &asoc->base.bind_addr, GFP_ATOMIC, 0);
4718 if (!repl)
4719 goto nomem;
4720
405426f6
DB
4721 /* Choose transport for INIT. */
4722 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
4723 SCTP_CHUNK(repl));
4724
1da177e4
LT
4725 /* Cast away the const modifier, as we want to just
4726 * rerun it through as a sideffect.
4727 */
ab38fb04
VY
4728 my_asoc = (struct sctp_association *)asoc;
4729 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(my_asoc));
1da177e4
LT
4730
4731 /* After sending the INIT, "A" starts the T1-init timer and
4732 * enters the COOKIE-WAIT state.
4733 */
4734 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4735 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4736 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
4737 return SCTP_DISPOSITION_CONSUME;
4738
4739nomem:
4740 return SCTP_DISPOSITION_NOMEM;
4741}
4742
4743/*
4744 * Process the SEND primitive.
4745 *
4746 * Section: 10.1 ULP-to-SCTP
4747 * E) Send
4748 *
4749 * Format: SEND(association id, buffer address, byte count [,context]
4750 * [,stream id] [,life time] [,destination transport address]
4751 * [,unorder flag] [,no-bundle flag] [,payload protocol-id] )
4752 * -> result
4753 *
4754 * This is the main method to send user data via SCTP.
4755 *
4756 * Mandatory attributes:
4757 *
4758 * o association id - local handle to the SCTP association
4759 *
4760 * o buffer address - the location where the user message to be
4761 * transmitted is stored;
4762 *
4763 * o byte count - The size of the user data in number of bytes;
4764 *
4765 * Optional attributes:
4766 *
4767 * o context - an optional 32 bit integer that will be carried in the
4768 * sending failure notification to the ULP if the transportation of
4769 * this User Message fails.
4770 *
4771 * o stream id - to indicate which stream to send the data on. If not
4772 * specified, stream 0 will be used.
4773 *
4774 * o life time - specifies the life time of the user data. The user data
4775 * will not be sent by SCTP after the life time expires. This
4776 * parameter can be used to avoid efforts to transmit stale
4777 * user messages. SCTP notifies the ULP if the data cannot be
4778 * initiated to transport (i.e. sent to the destination via SCTP's
4779 * send primitive) within the life time variable. However, the
4780 * user data will be transmitted if SCTP has attempted to transmit a
4781 * chunk before the life time expired.
4782 *
4783 * o destination transport address - specified as one of the destination
4784 * transport addresses of the peer endpoint to which this packet
4785 * should be sent. Whenever possible, SCTP should use this destination
4786 * transport address for sending the packets, instead of the current
4787 * primary path.
4788 *
4789 * o unorder flag - this flag, if present, indicates that the user
4790 * would like the data delivered in an unordered fashion to the peer
4791 * (i.e., the U flag is set to 1 on all DATA chunks carrying this
4792 * message).
4793 *
4794 * o no-bundle flag - instructs SCTP not to bundle this user data with
4795 * other outbound DATA chunks. SCTP MAY still bundle even when
4796 * this flag is present, when faced with network congestion.
4797 *
4798 * o payload protocol-id - A 32 bit unsigned integer that is to be
4799 * passed to the peer indicating the type of payload protocol data
4800 * being transmitted. This value is passed as opaque data by SCTP.
4801 *
4802 * The return value is the disposition.
4803 */
24cb81a6
EB
4804sctp_disposition_t sctp_sf_do_prm_send(struct net *net,
4805 const struct sctp_endpoint *ep,
1da177e4
LT
4806 const struct sctp_association *asoc,
4807 const sctp_subtype_t type,
4808 void *arg,
4809 sctp_cmd_seq_t *commands)
4810{
9c5c62be 4811 struct sctp_datamsg *msg = arg;
1da177e4 4812
9c5c62be 4813 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_MSG, SCTP_DATAMSG(msg));
1da177e4
LT
4814 return SCTP_DISPOSITION_CONSUME;
4815}
4816
4817/*
4818 * Process the SHUTDOWN primitive.
4819 *
4820 * Section: 10.1:
4821 * C) Shutdown
4822 *
4823 * Format: SHUTDOWN(association id)
4824 * -> result
4825 *
4826 * Gracefully closes an association. Any locally queued user data
4827 * will be delivered to the peer. The association will be terminated only
4828 * after the peer acknowledges all the SCTP packets sent. A success code
4829 * will be returned on successful termination of the association. If
4830 * attempting to terminate the association results in a failure, an error
4831 * code shall be returned.
4832 *
4833 * Mandatory attributes:
4834 *
4835 * o association id - local handle to the SCTP association
4836 *
4837 * Optional attributes:
4838 *
4839 * None.
4840 *
4841 * The return value is the disposition.
4842 */
4843sctp_disposition_t sctp_sf_do_9_2_prm_shutdown(
24cb81a6 4844 struct net *net,
1da177e4
LT
4845 const struct sctp_endpoint *ep,
4846 const struct sctp_association *asoc,
4847 const sctp_subtype_t type,
4848 void *arg,
4849 sctp_cmd_seq_t *commands)
4850{
4851 int disposition;
4852
4853 /* From 9.2 Shutdown of an Association
4854 * Upon receipt of the SHUTDOWN primitive from its upper
4855 * layer, the endpoint enters SHUTDOWN-PENDING state and
4856 * remains there until all outstanding data has been
4857 * acknowledged by its peer. The endpoint accepts no new data
4858 * from its upper layer, but retransmits data to the far end
4859 * if necessary to fill gaps.
4860 */
4861 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4862 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
4863
1da177e4
LT
4864 disposition = SCTP_DISPOSITION_CONSUME;
4865 if (sctp_outq_is_empty(&asoc->outqueue)) {
24cb81a6 4866 disposition = sctp_sf_do_9_2_start_shutdown(net, ep, asoc, type,
1da177e4
LT
4867 arg, commands);
4868 }
4869 return disposition;
4870}
4871
4872/*
4873 * Process the ABORT primitive.
4874 *
4875 * Section: 10.1:
4876 * C) Abort
4877 *
4878 * Format: Abort(association id [, cause code])
4879 * -> result
4880 *
4881 * Ungracefully closes an association. Any locally queued user data
4882 * will be discarded and an ABORT chunk is sent to the peer. A success code
4883 * will be returned on successful abortion of the association. If
4884 * attempting to abort the association results in a failure, an error
4885 * code shall be returned.
4886 *
4887 * Mandatory attributes:
4888 *
4889 * o association id - local handle to the SCTP association
4890 *
4891 * Optional attributes:
4892 *
4893 * o cause code - reason of the abort to be passed to the peer
4894 *
4895 * None.
4896 *
4897 * The return value is the disposition.
4898 */
4899sctp_disposition_t sctp_sf_do_9_1_prm_abort(
24cb81a6 4900 struct net *net,
1da177e4
LT
4901 const struct sctp_endpoint *ep,
4902 const struct sctp_association *asoc,
4903 const sctp_subtype_t type,
4904 void *arg,
4905 sctp_cmd_seq_t *commands)
4906{
4907 /* From 9.1 Abort of an Association
4908 * Upon receipt of the ABORT primitive from its upper
4909 * layer, the endpoint enters CLOSED state and
4910 * discard all outstanding data has been
4911 * acknowledged by its peer. The endpoint accepts no new data
4912 * from its upper layer, but retransmits data to the far end
4913 * if necessary to fill gaps.
4914 */
c164a9ba 4915 struct sctp_chunk *abort = arg;
1da177e4 4916
068d8bd3
XL
4917 if (abort)
4918 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
1da177e4
LT
4919
4920 /* Even if we can't send the ABORT due to low memory delete the
4921 * TCB. This is a departure from our typical NOMEM handling.
4922 */
4923
8de8c873
SS
4924 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4925 SCTP_ERROR(ECONNABORTED));
1da177e4
LT
4926 /* Delete the established association. */
4927 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5be291fe 4928 SCTP_PERR(SCTP_ERROR_USER_ABORT));
1da177e4 4929
b01a2407
EB
4930 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
4931 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
1da177e4 4932
649621e3 4933 return SCTP_DISPOSITION_ABORT;
1da177e4
LT
4934}
4935
4936/* We tried an illegal operation on an association which is closed. */
24cb81a6
EB
4937sctp_disposition_t sctp_sf_error_closed(struct net *net,
4938 const struct sctp_endpoint *ep,
1da177e4
LT
4939 const struct sctp_association *asoc,
4940 const sctp_subtype_t type,
4941 void *arg,
4942 sctp_cmd_seq_t *commands)
4943{
4944 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, SCTP_ERROR(-EINVAL));
4945 return SCTP_DISPOSITION_CONSUME;
4946}
4947
4948/* We tried an illegal operation on an association which is shutting
4949 * down.
4950 */
24cb81a6
EB
4951sctp_disposition_t sctp_sf_error_shutdown(struct net *net,
4952 const struct sctp_endpoint *ep,
1da177e4
LT
4953 const struct sctp_association *asoc,
4954 const sctp_subtype_t type,
4955 void *arg,
4956 sctp_cmd_seq_t *commands)
4957{
4958 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR,
4959 SCTP_ERROR(-ESHUTDOWN));
4960 return SCTP_DISPOSITION_CONSUME;
4961}
4962
4963/*
4964 * sctp_cookie_wait_prm_shutdown
4965 *
4966 * Section: 4 Note: 2
4967 * Verification Tag:
4968 * Inputs
4969 * (endpoint, asoc)
4970 *
4971 * The RFC does not explicitly address this issue, but is the route through the
4972 * state table when someone issues a shutdown while in COOKIE_WAIT state.
4973 *
4974 * Outputs
4975 * (timers)
4976 */
4977sctp_disposition_t sctp_sf_cookie_wait_prm_shutdown(
24cb81a6 4978 struct net *net,
1da177e4
LT
4979 const struct sctp_endpoint *ep,
4980 const struct sctp_association *asoc,
4981 const sctp_subtype_t type,
4982 void *arg,
4983 sctp_cmd_seq_t *commands)
4984{
4985 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4986 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4987
4988 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4989 SCTP_STATE(SCTP_STATE_CLOSED));
4990
b01a2407 4991 SCTP_INC_STATS(net, SCTP_MIB_SHUTDOWNS);
1da177e4
LT
4992
4993 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
4994
4995 return SCTP_DISPOSITION_DELETE_TCB;
4996}
4997
4998/*
4999 * sctp_cookie_echoed_prm_shutdown
5000 *
5001 * Section: 4 Note: 2
5002 * Verification Tag:
5003 * Inputs
5004 * (endpoint, asoc)
5005 *
5006 * The RFC does not explcitly address this issue, but is the route through the
5007 * state table when someone issues a shutdown while in COOKIE_ECHOED state.
5008 *
5009 * Outputs
5010 * (timers)
5011 */
5012sctp_disposition_t sctp_sf_cookie_echoed_prm_shutdown(
24cb81a6 5013 struct net *net,
1da177e4
LT
5014 const struct sctp_endpoint *ep,
5015 const struct sctp_association *asoc,
5016 const sctp_subtype_t type,
5017 void *arg, sctp_cmd_seq_t *commands)
5018{
5019 /* There is a single T1 timer, so we should be able to use
5020 * common function with the COOKIE-WAIT state.
5021 */
24cb81a6 5022 return sctp_sf_cookie_wait_prm_shutdown(net, ep, asoc, type, arg, commands);
1da177e4
LT
5023}
5024
5025/*
5026 * sctp_sf_cookie_wait_prm_abort
5027 *
5028 * Section: 4 Note: 2
5029 * Verification Tag:
5030 * Inputs
5031 * (endpoint, asoc)
5032 *
5033 * The RFC does not explicitly address this issue, but is the route through the
5034 * state table when someone issues an abort while in COOKIE_WAIT state.
5035 *
5036 * Outputs
5037 * (timers)
5038 */
5039sctp_disposition_t sctp_sf_cookie_wait_prm_abort(
24cb81a6 5040 struct net *net,
1da177e4
LT
5041 const struct sctp_endpoint *ep,
5042 const struct sctp_association *asoc,
5043 const sctp_subtype_t type,
5044 void *arg,
5045 sctp_cmd_seq_t *commands)
5046{
c164a9ba 5047 struct sctp_chunk *abort = arg;
1da177e4
LT
5048
5049 /* Stop T1-init timer */
5050 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5051 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
1da177e4 5052
068d8bd3
XL
5053 if (abort)
5054 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
1da177e4
LT
5055
5056 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5057 SCTP_STATE(SCTP_STATE_CLOSED));
5058
b01a2407 5059 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
1da177e4
LT
5060
5061 /* Even if we can't send the ABORT due to low memory delete the
5062 * TCB. This is a departure from our typical NOMEM handling.
5063 */
5064
8de8c873
SS
5065 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5066 SCTP_ERROR(ECONNREFUSED));
1da177e4
LT
5067 /* Delete the established association. */
5068 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
dc251b2b 5069 SCTP_PERR(SCTP_ERROR_USER_ABORT));
1da177e4 5070
649621e3 5071 return SCTP_DISPOSITION_ABORT;
1da177e4
LT
5072}
5073
5074/*
5075 * sctp_sf_cookie_echoed_prm_abort
5076 *
5077 * Section: 4 Note: 3
5078 * Verification Tag:
5079 * Inputs
5080 * (endpoint, asoc)
5081 *
5082 * The RFC does not explcitly address this issue, but is the route through the
5083 * state table when someone issues an abort while in COOKIE_ECHOED state.
5084 *
5085 * Outputs
5086 * (timers)
5087 */
5088sctp_disposition_t sctp_sf_cookie_echoed_prm_abort(
24cb81a6 5089 struct net *net,
1da177e4
LT
5090 const struct sctp_endpoint *ep,
5091 const struct sctp_association *asoc,
5092 const sctp_subtype_t type,
5093 void *arg,
5094 sctp_cmd_seq_t *commands)
5095{
5096 /* There is a single T1 timer, so we should be able to use
5097 * common function with the COOKIE-WAIT state.
5098 */
24cb81a6 5099 return sctp_sf_cookie_wait_prm_abort(net, ep, asoc, type, arg, commands);
1da177e4
LT
5100}
5101
5102/*
5103 * sctp_sf_shutdown_pending_prm_abort
5104 *
5105 * Inputs
5106 * (endpoint, asoc)
5107 *
5108 * The RFC does not explicitly address this issue, but is the route through the
5109 * state table when someone issues an abort while in SHUTDOWN-PENDING state.
5110 *
5111 * Outputs
5112 * (timers)
5113 */
5114sctp_disposition_t sctp_sf_shutdown_pending_prm_abort(
24cb81a6 5115 struct net *net,
1da177e4
LT
5116 const struct sctp_endpoint *ep,
5117 const struct sctp_association *asoc,
5118 const sctp_subtype_t type,
5119 void *arg,
5120 sctp_cmd_seq_t *commands)
5121{
5122 /* Stop the T5-shutdown guard timer. */
5123 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5124 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5125
24cb81a6 5126 return sctp_sf_do_9_1_prm_abort(net, ep, asoc, type, arg, commands);
1da177e4
LT
5127}
5128
5129/*
5130 * sctp_sf_shutdown_sent_prm_abort
5131 *
5132 * Inputs
5133 * (endpoint, asoc)
5134 *
5135 * The RFC does not explicitly address this issue, but is the route through the
5136 * state table when someone issues an abort while in SHUTDOWN-SENT state.
5137 *
5138 * Outputs
5139 * (timers)
5140 */
5141sctp_disposition_t sctp_sf_shutdown_sent_prm_abort(
24cb81a6 5142 struct net *net,
1da177e4
LT
5143 const struct sctp_endpoint *ep,
5144 const struct sctp_association *asoc,
5145 const sctp_subtype_t type,
5146 void *arg,
5147 sctp_cmd_seq_t *commands)
5148{
5149 /* Stop the T2-shutdown timer. */
5150 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5151 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5152
5153 /* Stop the T5-shutdown guard timer. */
5154 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5155 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5156
24cb81a6 5157 return sctp_sf_do_9_1_prm_abort(net, ep, asoc, type, arg, commands);
1da177e4
LT
5158}
5159
5160/*
5161 * sctp_sf_cookie_echoed_prm_abort
5162 *
5163 * Inputs
5164 * (endpoint, asoc)
5165 *
5166 * The RFC does not explcitly address this issue, but is the route through the
5167 * state table when someone issues an abort while in COOKIE_ECHOED state.
5168 *
5169 * Outputs
5170 * (timers)
5171 */
5172sctp_disposition_t sctp_sf_shutdown_ack_sent_prm_abort(
24cb81a6 5173 struct net *net,
1da177e4
LT
5174 const struct sctp_endpoint *ep,
5175 const struct sctp_association *asoc,
5176 const sctp_subtype_t type,
5177 void *arg,
5178 sctp_cmd_seq_t *commands)
5179{
5180 /* The same T2 timer, so we should be able to use
5181 * common function with the SHUTDOWN-SENT state.
5182 */
24cb81a6 5183 return sctp_sf_shutdown_sent_prm_abort(net, ep, asoc, type, arg, commands);
1da177e4
LT
5184}
5185
5186/*
5187 * Process the REQUESTHEARTBEAT primitive
5188 *
5189 * 10.1 ULP-to-SCTP
5190 * J) Request Heartbeat
5191 *
5192 * Format: REQUESTHEARTBEAT(association id, destination transport address)
5193 *
5194 * -> result
5195 *
5196 * Instructs the local endpoint to perform a HeartBeat on the specified
5197 * destination transport address of the given association. The returned
5198 * result should indicate whether the transmission of the HEARTBEAT
5199 * chunk to the destination address is successful.
5200 *
5201 * Mandatory attributes:
5202 *
5203 * o association id - local handle to the SCTP association
5204 *
5205 * o destination transport address - the transport address of the
5206 * association on which a heartbeat should be issued.
5207 */
5208sctp_disposition_t sctp_sf_do_prm_requestheartbeat(
24cb81a6 5209 struct net *net,
1da177e4
LT
5210 const struct sctp_endpoint *ep,
5211 const struct sctp_association *asoc,
5212 const sctp_subtype_t type,
5213 void *arg,
5214 sctp_cmd_seq_t *commands)
5215{
fb78525a
VY
5216 if (SCTP_DISPOSITION_NOMEM == sctp_sf_heartbeat(ep, asoc, type,
5217 (struct sctp_transport *)arg, commands))
5218 return SCTP_DISPOSITION_NOMEM;
5219
5220 /*
5221 * RFC 2960 (bis), section 8.3
5222 *
5223 * D) Request an on-demand HEARTBEAT on a specific destination
5224 * transport address of a given association.
5225 *
5226 * The endpoint should increment the respective error counter of
5227 * the destination transport address each time a HEARTBEAT is sent
5228 * to that address and not acknowledged within one RTO.
5229 *
5230 */
7e99013a 5231 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_HB_SENT,
fb78525a
VY
5232 SCTP_TRANSPORT(arg));
5233 return SCTP_DISPOSITION_CONSUME;
1da177e4
LT
5234}
5235
5236/*
5237 * ADDIP Section 4.1 ASCONF Chunk Procedures
5238 * When an endpoint has an ASCONF signaled change to be sent to the
5239 * remote endpoint it should do A1 to A9
5240 */
24cb81a6
EB
5241sctp_disposition_t sctp_sf_do_prm_asconf(struct net *net,
5242 const struct sctp_endpoint *ep,
1da177e4
LT
5243 const struct sctp_association *asoc,
5244 const sctp_subtype_t type,
5245 void *arg,
5246 sctp_cmd_seq_t *commands)
5247{
5248 struct sctp_chunk *chunk = arg;
5249
5250 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
5251 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
5252 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
5253 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
5254 return SCTP_DISPOSITION_CONSUME;
5255}
5256
7a090b04
XL
5257/* RE-CONFIG Section 5.1 RECONF Chunk Procedures */
5258sctp_disposition_t sctp_sf_do_prm_reconf(struct net *net,
5259 const struct sctp_endpoint *ep,
5260 const struct sctp_association *asoc,
5261 const sctp_subtype_t type,
5262 void *arg, sctp_cmd_seq_t *commands)
5263{
5264 struct sctp_chunk *chunk = arg;
5265
5266 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
5267 return SCTP_DISPOSITION_CONSUME;
5268}
5269
1da177e4
LT
5270/*
5271 * Ignore the primitive event
5272 *
5273 * The return value is the disposition of the primitive.
5274 */
5275sctp_disposition_t sctp_sf_ignore_primitive(
24cb81a6 5276 struct net *net,
1da177e4
LT
5277 const struct sctp_endpoint *ep,
5278 const struct sctp_association *asoc,
5279 const sctp_subtype_t type,
5280 void *arg,
5281 sctp_cmd_seq_t *commands)
5282{
bb33381d
DB
5283 pr_debug("%s: primitive type:%d is ignored\n", __func__,
5284 type.primitive);
5285
1da177e4
LT
5286 return SCTP_DISPOSITION_DISCARD;
5287}
5288
5289/***************************************************************************
5290 * These are the state functions for the OTHER events.
5291 ***************************************************************************/
5292
e1cdd553
WY
5293/*
5294 * When the SCTP stack has no more user data to send or retransmit, this
5295 * notification is given to the user. Also, at the time when a user app
5296 * subscribes to this event, if there is no data to be sent or
5297 * retransmit, the stack will immediately send up this notification.
5298 */
5299sctp_disposition_t sctp_sf_do_no_pending_tsn(
24cb81a6 5300 struct net *net,
e1cdd553
WY
5301 const struct sctp_endpoint *ep,
5302 const struct sctp_association *asoc,
5303 const sctp_subtype_t type,
5304 void *arg,
5305 sctp_cmd_seq_t *commands)
5306{
5307 struct sctp_ulpevent *event;
5308
5309 event = sctp_ulpevent_make_sender_dry_event(asoc, GFP_ATOMIC);
5310 if (!event)
5311 return SCTP_DISPOSITION_NOMEM;
5312
5313 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(event));
5314
5315 return SCTP_DISPOSITION_CONSUME;
5316}
5317
1da177e4
LT
5318/*
5319 * Start the shutdown negotiation.
5320 *
5321 * From Section 9.2:
5322 * Once all its outstanding data has been acknowledged, the endpoint
5323 * shall send a SHUTDOWN chunk to its peer including in the Cumulative
5324 * TSN Ack field the last sequential TSN it has received from the peer.
5325 * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT
5326 * state. If the timer expires, the endpoint must re-send the SHUTDOWN
5327 * with the updated last sequential TSN received from its peer.
5328 *
5329 * The return value is the disposition.
5330 */
5331sctp_disposition_t sctp_sf_do_9_2_start_shutdown(
24cb81a6 5332 struct net *net,
1da177e4
LT
5333 const struct sctp_endpoint *ep,
5334 const struct sctp_association *asoc,
5335 const sctp_subtype_t type,
5336 void *arg,
5337 sctp_cmd_seq_t *commands)
5338{
5339 struct sctp_chunk *reply;
5340
5341 /* Once all its outstanding data has been acknowledged, the
5342 * endpoint shall send a SHUTDOWN chunk to its peer including
5343 * in the Cumulative TSN Ack field the last sequential TSN it
5344 * has received from the peer.
5345 */
5346 reply = sctp_make_shutdown(asoc, NULL);
5347 if (!reply)
5348 goto nomem;
5349
5350 /* Set the transport for the SHUTDOWN chunk and the timeout for the
5351 * T2-shutdown timer.
5352 */
5353 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5354
5355 /* It shall then start the T2-shutdown timer */
5356 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
5357 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5358
536428a9
WY
5359 /* RFC 4960 Section 9.2
5360 * The sender of the SHUTDOWN MAY also start an overall guard timer
5361 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5362 */
f8d96052 5363 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
536428a9
WY
5364 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5365
9f70f46b 5366 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
1da177e4
LT
5367 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5368 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
5369
5370 /* and enter the SHUTDOWN-SENT state. */
5371 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5372 SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT));
5373
5374 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5375 *
5376 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
d808ad9a 5377 * or SHUTDOWN-ACK.
1da177e4
LT
5378 */
5379 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
5380
5381 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5382
5383 return SCTP_DISPOSITION_CONSUME;
5384
5385nomem:
5386 return SCTP_DISPOSITION_NOMEM;
5387}
5388
5389/*
5390 * Generate a SHUTDOWN ACK now that everything is SACK'd.
5391 *
5392 * From Section 9.2:
5393 *
5394 * If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5395 * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own,
5396 * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the
5397 * endpoint must re-send the SHUTDOWN ACK.
5398 *
5399 * The return value is the disposition.
5400 */
5401sctp_disposition_t sctp_sf_do_9_2_shutdown_ack(
24cb81a6 5402 struct net *net,
1da177e4
LT
5403 const struct sctp_endpoint *ep,
5404 const struct sctp_association *asoc,
5405 const sctp_subtype_t type,
5406 void *arg,
5407 sctp_cmd_seq_t *commands)
5408{
5409 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
5410 struct sctp_chunk *reply;
5411
5412 /* There are 2 ways of getting here:
5413 * 1) called in response to a SHUTDOWN chunk
5414 * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued.
5415 *
5416 * For the case (2), the arg parameter is set to NULL. We need
5417 * to check that we have a chunk before accessing it's fields.
5418 */
5419 if (chunk) {
5420 if (!sctp_vtag_verify(chunk, asoc))
24cb81a6 5421 return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands);
1da177e4
LT
5422
5423 /* Make sure that the SHUTDOWN chunk has a valid length. */
5424 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_shutdown_chunk_t)))
24cb81a6 5425 return sctp_sf_violation_chunklen(net, ep, asoc, type, arg,
1da177e4
LT
5426 commands);
5427 }
5428
5429 /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5430 * shall send a SHUTDOWN ACK ...
5431 */
5432 reply = sctp_make_shutdown_ack(asoc, chunk);
5433 if (!reply)
5434 goto nomem;
5435
5436 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
5437 * the T2-shutdown timer.
5438 */
5439 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5440
5441 /* and start/restart a T2-shutdown timer of its own, */
5442 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5443 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5444
9f70f46b 5445 if (asoc->timeouts[SCTP_EVENT_TIMEOUT_AUTOCLOSE])
1da177e4
LT
5446 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5447 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
5448
5449 /* Enter the SHUTDOWN-ACK-SENT state. */
5450 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5451 SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT));
5452
5453 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5454 *
5455 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
d808ad9a 5456 * or SHUTDOWN-ACK.
1da177e4
LT
5457 */
5458 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
5459
5460 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5461
5462 return SCTP_DISPOSITION_CONSUME;
5463
5464nomem:
5465 return SCTP_DISPOSITION_NOMEM;
5466}
5467
5468/*
5469 * Ignore the event defined as other
5470 *
5471 * The return value is the disposition of the event.
5472 */
24cb81a6
EB
5473sctp_disposition_t sctp_sf_ignore_other(struct net *net,
5474 const struct sctp_endpoint *ep,
1da177e4
LT
5475 const struct sctp_association *asoc,
5476 const sctp_subtype_t type,
5477 void *arg,
5478 sctp_cmd_seq_t *commands)
5479{
bb33381d
DB
5480 pr_debug("%s: the event other type:%d is ignored\n",
5481 __func__, type.other);
5482
1da177e4
LT
5483 return SCTP_DISPOSITION_DISCARD;
5484}
5485
5486/************************************************************
5487 * These are the state functions for handling timeout events.
5488 ************************************************************/
5489
5490/*
5491 * RTX Timeout
5492 *
5493 * Section: 6.3.3 Handle T3-rtx Expiration
5494 *
5495 * Whenever the retransmission timer T3-rtx expires for a destination
5496 * address, do the following:
5497 * [See below]
5498 *
5499 * The return value is the disposition of the chunk.
5500 */
24cb81a6
EB
5501sctp_disposition_t sctp_sf_do_6_3_3_rtx(struct net *net,
5502 const struct sctp_endpoint *ep,
1da177e4
LT
5503 const struct sctp_association *asoc,
5504 const sctp_subtype_t type,
5505 void *arg,
5506 sctp_cmd_seq_t *commands)
5507{
5508 struct sctp_transport *transport = arg;
5509
b01a2407 5510 SCTP_INC_STATS(net, SCTP_MIB_T3_RTX_EXPIREDS);
ac0b0462 5511
1da177e4 5512 if (asoc->overall_error_count >= asoc->max_retrans) {
8a0d19c5 5513 if (asoc->peer.zero_window_announced &&
5514 asoc->state == SCTP_STATE_SHUTDOWN_PENDING) {
f8d96052
TG
5515 /*
5516 * We are here likely because the receiver had its rwnd
5517 * closed for a while and we have not been able to
5518 * transmit the locally queued data within the maximum
5519 * retransmission attempts limit. Start the T5
5520 * shutdown guard timer to give the receiver one last
5521 * chance and some additional time to recover before
5522 * aborting.
5523 */
5524 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START_ONCE,
5525 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
5526 } else {
5527 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5528 SCTP_ERROR(ETIMEDOUT));
5529 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5530 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5531 SCTP_PERR(SCTP_ERROR_NO_ERROR));
b01a2407
EB
5532 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5533 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
f8d96052
TG
5534 return SCTP_DISPOSITION_DELETE_TCB;
5535 }
1da177e4
LT
5536 }
5537
5538 /* E1) For the destination address for which the timer
5539 * expires, adjust its ssthresh with rules defined in Section
5540 * 7.2.3 and set the cwnd <- MTU.
5541 */
5542
5543 /* E2) For the destination address for which the timer
5544 * expires, set RTO <- RTO * 2 ("back off the timer"). The
5545 * maximum value discussed in rule C7 above (RTO.max) may be
5546 * used to provide an upper bound to this doubling operation.
5547 */
5548
5549 /* E3) Determine how many of the earliest (i.e., lowest TSN)
5550 * outstanding DATA chunks for the address for which the
5551 * T3-rtx has expired will fit into a single packet, subject
5552 * to the MTU constraint for the path corresponding to the
5553 * destination transport address to which the retransmission
5554 * is being sent (this may be different from the address for
5555 * which the timer expires [see Section 6.4]). Call this
5556 * value K. Bundle and retransmit those K DATA chunks in a
5557 * single packet to the destination endpoint.
5558 *
5559 * Note: Any DATA chunks that were sent to the address for
5560 * which the T3-rtx timer expired but did not fit in one MTU
5561 * (rule E3 above), should be marked for retransmission and
5562 * sent as soon as cwnd allows (normally when a SACK arrives).
5563 */
5564
1da177e4
LT
5565 /* Do some failure management (Section 8.2). */
5566 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
5567
1845a579
VY
5568 /* NB: Rules E4 and F1 are implicit in R1. */
5569 sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN, SCTP_TRANSPORT(transport));
5570
1da177e4
LT
5571 return SCTP_DISPOSITION_CONSUME;
5572}
5573
5574/*
5575 * Generate delayed SACK on timeout
5576 *
5577 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
5578 *
5579 * The guidelines on delayed acknowledgement algorithm specified in
5580 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
5581 * acknowledgement SHOULD be generated for at least every second packet
5582 * (not every second DATA chunk) received, and SHOULD be generated
5583 * within 200 ms of the arrival of any unacknowledged DATA chunk. In
5584 * some situations it may be beneficial for an SCTP transmitter to be
5585 * more conservative than the algorithms detailed in this document
5586 * allow. However, an SCTP transmitter MUST NOT be more aggressive than
5587 * the following algorithms allow.
5588 */
24cb81a6
EB
5589sctp_disposition_t sctp_sf_do_6_2_sack(struct net *net,
5590 const struct sctp_endpoint *ep,
1da177e4
LT
5591 const struct sctp_association *asoc,
5592 const sctp_subtype_t type,
5593 void *arg,
5594 sctp_cmd_seq_t *commands)
5595{
b01a2407 5596 SCTP_INC_STATS(net, SCTP_MIB_DELAY_SACK_EXPIREDS);
1da177e4
LT
5597 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
5598 return SCTP_DISPOSITION_CONSUME;
5599}
5600
5601/*
3f7a87d2 5602 * sctp_sf_t1_init_timer_expire
1da177e4
LT
5603 *
5604 * Section: 4 Note: 2
5605 * Verification Tag:
5606 * Inputs
5607 * (endpoint, asoc)
5608 *
5609 * RFC 2960 Section 4 Notes
5610 * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT
5611 * and re-start the T1-init timer without changing state. This MUST
5612 * be repeated up to 'Max.Init.Retransmits' times. After that, the
5613 * endpoint MUST abort the initialization process and report the
5614 * error to SCTP user.
5615 *
3f7a87d2
FF
5616 * Outputs
5617 * (timers, events)
5618 *
5619 */
24cb81a6
EB
5620sctp_disposition_t sctp_sf_t1_init_timer_expire(struct net *net,
5621 const struct sctp_endpoint *ep,
3f7a87d2
FF
5622 const struct sctp_association *asoc,
5623 const sctp_subtype_t type,
5624 void *arg,
5625 sctp_cmd_seq_t *commands)
5626{
5627 struct sctp_chunk *repl = NULL;
5628 struct sctp_bind_addr *bp;
5629 int attempts = asoc->init_err_counter + 1;
5630
bb33381d
DB
5631 pr_debug("%s: timer T1 expired (INIT)\n", __func__);
5632
b01a2407 5633 SCTP_INC_STATS(net, SCTP_MIB_T1_INIT_EXPIREDS);
3f7a87d2 5634
81845c21 5635 if (attempts <= asoc->max_init_attempts) {
3f7a87d2
FF
5636 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
5637 repl = sctp_make_init(asoc, bp, GFP_ATOMIC, 0);
5638 if (!repl)
5639 return SCTP_DISPOSITION_NOMEM;
5640
5641 /* Choose transport for INIT. */
5642 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
5643 SCTP_CHUNK(repl));
5644
5645 /* Issue a sideeffect to do the needed accounting. */
5646 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_RESTART,
5647 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
5648
5649 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
5650 } else {
bb33381d
DB
5651 pr_debug("%s: giving up on INIT, attempts:%d "
5652 "max_init_attempts:%d\n", __func__, attempts,
5653 asoc->max_init_attempts);
5654
8de8c873
SS
5655 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5656 SCTP_ERROR(ETIMEDOUT));
3f7a87d2 5657 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
dc251b2b 5658 SCTP_PERR(SCTP_ERROR_NO_ERROR));
3f7a87d2
FF
5659 return SCTP_DISPOSITION_DELETE_TCB;
5660 }
5661
5662 return SCTP_DISPOSITION_CONSUME;
5663}
5664
5665/*
5666 * sctp_sf_t1_cookie_timer_expire
5667 *
5668 * Section: 4 Note: 2
5669 * Verification Tag:
5670 * Inputs
5671 * (endpoint, asoc)
5672 *
5673 * RFC 2960 Section 4 Notes
5674 * 3) If the T1-cookie timer expires, the endpoint MUST retransmit
1da177e4
LT
5675 * COOKIE ECHO and re-start the T1-cookie timer without changing
5676 * state. This MUST be repeated up to 'Max.Init.Retransmits' times.
5677 * After that, the endpoint MUST abort the initialization process and
5678 * report the error to SCTP user.
5679 *
5680 * Outputs
5681 * (timers, events)
5682 *
5683 */
24cb81a6
EB
5684sctp_disposition_t sctp_sf_t1_cookie_timer_expire(struct net *net,
5685 const struct sctp_endpoint *ep,
1da177e4
LT
5686 const struct sctp_association *asoc,
5687 const sctp_subtype_t type,
5688 void *arg,
5689 sctp_cmd_seq_t *commands)
5690{
3f7a87d2
FF
5691 struct sctp_chunk *repl = NULL;
5692 int attempts = asoc->init_err_counter + 1;
1da177e4 5693
bb33381d
DB
5694 pr_debug("%s: timer T1 expired (COOKIE-ECHO)\n", __func__);
5695
b01a2407 5696 SCTP_INC_STATS(net, SCTP_MIB_T1_COOKIE_EXPIREDS);
1da177e4 5697
81845c21 5698 if (attempts <= asoc->max_init_attempts) {
3f7a87d2 5699 repl = sctp_make_cookie_echo(asoc, NULL);
1da177e4 5700 if (!repl)
3f7a87d2 5701 return SCTP_DISPOSITION_NOMEM;
1da177e4 5702
96cd0d3d
VY
5703 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
5704 SCTP_CHUNK(repl));
1da177e4 5705 /* Issue a sideeffect to do the needed accounting. */
3f7a87d2
FF
5706 sctp_add_cmd_sf(commands, SCTP_CMD_COOKIEECHO_RESTART,
5707 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
5708
1da177e4
LT
5709 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
5710 } else {
8de8c873
SS
5711 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5712 SCTP_ERROR(ETIMEDOUT));
1da177e4 5713 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
dc251b2b 5714 SCTP_PERR(SCTP_ERROR_NO_ERROR));
1da177e4
LT
5715 return SCTP_DISPOSITION_DELETE_TCB;
5716 }
5717
5718 return SCTP_DISPOSITION_CONSUME;
1da177e4
LT
5719}
5720
5721/* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN
5722 * with the updated last sequential TSN received from its peer.
5723 *
5724 * An endpoint should limit the number of retransmissions of the
5725 * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'.
5726 * If this threshold is exceeded the endpoint should destroy the TCB and
5727 * MUST report the peer endpoint unreachable to the upper layer (and
5728 * thus the association enters the CLOSED state). The reception of any
5729 * packet from its peer (i.e. as the peer sends all of its queued DATA
5730 * chunks) should clear the endpoint's retransmission count and restart
5731 * the T2-Shutdown timer, giving its peer ample opportunity to transmit
5732 * all of its queued DATA chunks that have not yet been sent.
5733 */
24cb81a6
EB
5734sctp_disposition_t sctp_sf_t2_timer_expire(struct net *net,
5735 const struct sctp_endpoint *ep,
1da177e4
LT
5736 const struct sctp_association *asoc,
5737 const sctp_subtype_t type,
5738 void *arg,
5739 sctp_cmd_seq_t *commands)
5740{
5741 struct sctp_chunk *reply = NULL;
5742
bb33381d
DB
5743 pr_debug("%s: timer T2 expired\n", __func__);
5744
b01a2407 5745 SCTP_INC_STATS(net, SCTP_MIB_T2_SHUTDOWN_EXPIREDS);
ac0b0462 5746
58fbbed4
NH
5747 ((struct sctp_association *)asoc)->shutdown_retries++;
5748
1da177e4 5749 if (asoc->overall_error_count >= asoc->max_retrans) {
8de8c873
SS
5750 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5751 SCTP_ERROR(ETIMEDOUT));
1da177e4
LT
5752 /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5753 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5be291fe 5754 SCTP_PERR(SCTP_ERROR_NO_ERROR));
b01a2407
EB
5755 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5756 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
1da177e4
LT
5757 return SCTP_DISPOSITION_DELETE_TCB;
5758 }
5759
5760 switch (asoc->state) {
5761 case SCTP_STATE_SHUTDOWN_SENT:
5762 reply = sctp_make_shutdown(asoc, NULL);
5763 break;
5764
5765 case SCTP_STATE_SHUTDOWN_ACK_SENT:
5766 reply = sctp_make_shutdown_ack(asoc, NULL);
5767 break;
5768
5769 default:
5770 BUG();
5771 break;
3ff50b79 5772 }
1da177e4
LT
5773
5774 if (!reply)
5775 goto nomem;
5776
6345b199
WY
5777 /* Do some failure management (Section 8.2).
5778 * If we remove the transport an SHUTDOWN was last sent to, don't
5779 * do failure management.
5780 */
5781 if (asoc->shutdown_last_sent_to)
5782 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
5783 SCTP_TRANSPORT(asoc->shutdown_last_sent_to));
1da177e4
LT
5784
5785 /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for
5786 * the T2-shutdown timer.
5787 */
5788 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
5789
5790 /* Restart the T2-shutdown timer. */
5791 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5792 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
5793 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
5794 return SCTP_DISPOSITION_CONSUME;
5795
5796nomem:
5797 return SCTP_DISPOSITION_NOMEM;
5798}
5799
5800/*
5801 * ADDIP Section 4.1 ASCONF CHunk Procedures
5802 * If the T4 RTO timer expires the endpoint should do B1 to B5
5803 */
5804sctp_disposition_t sctp_sf_t4_timer_expire(
24cb81a6 5805 struct net *net,
1da177e4
LT
5806 const struct sctp_endpoint *ep,
5807 const struct sctp_association *asoc,
5808 const sctp_subtype_t type,
5809 void *arg,
5810 sctp_cmd_seq_t *commands)
5811{
5812 struct sctp_chunk *chunk = asoc->addip_last_asconf;
5813 struct sctp_transport *transport = chunk->transport;
5814
b01a2407 5815 SCTP_INC_STATS(net, SCTP_MIB_T4_RTO_EXPIREDS);
ac0b0462 5816
1da177e4
LT
5817 /* ADDIP 4.1 B1) Increment the error counters and perform path failure
5818 * detection on the appropriate destination address as defined in
5819 * RFC2960 [5] section 8.1 and 8.2.
5820 */
10a43cea
WY
5821 if (transport)
5822 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
5823 SCTP_TRANSPORT(transport));
1da177e4
LT
5824
5825 /* Reconfig T4 timer and transport. */
5826 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
5827
5828 /* ADDIP 4.1 B2) Increment the association error counters and perform
5829 * endpoint failure detection on the association as defined in
5830 * RFC2960 [5] section 8.1 and 8.2.
5831 * association error counter is incremented in SCTP_CMD_STRIKE.
5832 */
5833 if (asoc->overall_error_count >= asoc->max_retrans) {
5834 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
5835 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
8de8c873
SS
5836 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5837 SCTP_ERROR(ETIMEDOUT));
1da177e4 5838 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5be291fe 5839 SCTP_PERR(SCTP_ERROR_NO_ERROR));
b01a2407
EB
5840 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5841 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
1da177e4
LT
5842 return SCTP_DISPOSITION_ABORT;
5843 }
5844
5845 /* ADDIP 4.1 B3) Back-off the destination address RTO value to which
5846 * the ASCONF chunk was sent by doubling the RTO timer value.
5847 * This is done in SCTP_CMD_STRIKE.
5848 */
5849
5850 /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible
5851 * choose an alternate destination address (please refer to RFC2960
5852 * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this
d808ad9a 5853 * chunk, it MUST be the same (including its serial number) as the last
1da177e4
LT
5854 * ASCONF sent.
5855 */
5856 sctp_chunk_hold(asoc->addip_last_asconf);
5857 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
5858 SCTP_CHUNK(asoc->addip_last_asconf));
5859
5860 /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different
5861 * destination is selected, then the RTO used will be that of the new
5862 * destination address.
5863 */
5864 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
5865 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
5866
5867 return SCTP_DISPOSITION_CONSUME;
5868}
5869
5870/* sctpimpguide-05 Section 2.12.2
5871 * The sender of the SHUTDOWN MAY also start an overall guard timer
5872 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5873 * At the expiration of this timer the sender SHOULD abort the association
5874 * by sending an ABORT chunk.
5875 */
24cb81a6
EB
5876sctp_disposition_t sctp_sf_t5_timer_expire(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 struct sctp_chunk *reply = NULL;
5884
bb33381d
DB
5885 pr_debug("%s: timer T5 expired\n", __func__);
5886
b01a2407 5887 SCTP_INC_STATS(net, SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS);
1da177e4
LT
5888
5889 reply = sctp_make_abort(asoc, NULL, 0);
5890 if (!reply)
5891 goto nomem;
5892
5893 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
8de8c873
SS
5894 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5895 SCTP_ERROR(ETIMEDOUT));
1da177e4 5896 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5be291fe 5897 SCTP_PERR(SCTP_ERROR_NO_ERROR));
1da177e4 5898
b01a2407
EB
5899 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
5900 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
a1080a8b 5901
1da177e4
LT
5902 return SCTP_DISPOSITION_DELETE_TCB;
5903nomem:
5904 return SCTP_DISPOSITION_NOMEM;
5905}
5906
5907/* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires,
5908 * the association is automatically closed by starting the shutdown process.
5909 * The work that needs to be done is same as when SHUTDOWN is initiated by
5910 * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown().
5911 */
5912sctp_disposition_t sctp_sf_autoclose_timer_expire(
24cb81a6 5913 struct net *net,
1da177e4
LT
5914 const struct sctp_endpoint *ep,
5915 const struct sctp_association *asoc,
5916 const sctp_subtype_t type,
5917 void *arg,
5918 sctp_cmd_seq_t *commands)
5919{
5920 int disposition;
5921
b01a2407 5922 SCTP_INC_STATS(net, SCTP_MIB_AUTOCLOSE_EXPIREDS);
ac0b0462 5923
1da177e4
LT
5924 /* From 9.2 Shutdown of an Association
5925 * Upon receipt of the SHUTDOWN primitive from its upper
5926 * layer, the endpoint enters SHUTDOWN-PENDING state and
5927 * remains there until all outstanding data has been
5928 * acknowledged by its peer. The endpoint accepts no new data
5929 * from its upper layer, but retransmits data to the far end
5930 * if necessary to fill gaps.
5931 */
5932 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
5933 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
5934
1da177e4
LT
5935 disposition = SCTP_DISPOSITION_CONSUME;
5936 if (sctp_outq_is_empty(&asoc->outqueue)) {
24cb81a6 5937 disposition = sctp_sf_do_9_2_start_shutdown(net, ep, asoc, type,
1da177e4
LT
5938 arg, commands);
5939 }
5940 return disposition;
5941}
5942
5943/*****************************************************************************
5944 * These are sa state functions which could apply to all types of events.
5945 ****************************************************************************/
5946
5947/*
5948 * This table entry is not implemented.
5949 *
5950 * Inputs
5951 * (endpoint, asoc, chunk)
5952 *
5953 * The return value is the disposition of the chunk.
5954 */
24cb81a6
EB
5955sctp_disposition_t sctp_sf_not_impl(struct net *net,
5956 const struct sctp_endpoint *ep,
1da177e4
LT
5957 const struct sctp_association *asoc,
5958 const sctp_subtype_t type,
5959 void *arg,
5960 sctp_cmd_seq_t *commands)
5961{
5962 return SCTP_DISPOSITION_NOT_IMPL;
5963}
5964
5965/*
5966 * This table entry represents a bug.
5967 *
5968 * Inputs
5969 * (endpoint, asoc, chunk)
5970 *
5971 * The return value is the disposition of the chunk.
5972 */
24cb81a6
EB
5973sctp_disposition_t sctp_sf_bug(struct net *net,
5974 const struct sctp_endpoint *ep,
1da177e4
LT
5975 const struct sctp_association *asoc,
5976 const sctp_subtype_t type,
5977 void *arg,
5978 sctp_cmd_seq_t *commands)
5979{
5980 return SCTP_DISPOSITION_BUG;
5981}
5982
5983/*
5984 * This table entry represents the firing of a timer in the wrong state.
5985 * Since timer deletion cannot be guaranteed a timer 'may' end up firing
5986 * when the association is in the wrong state. This event should
5987 * be ignored, so as to prevent any rearming of the timer.
5988 *
5989 * Inputs
5990 * (endpoint, asoc, chunk)
5991 *
5992 * The return value is the disposition of the chunk.
5993 */
24cb81a6
EB
5994sctp_disposition_t sctp_sf_timer_ignore(struct net *net,
5995 const struct sctp_endpoint *ep,
1da177e4
LT
5996 const struct sctp_association *asoc,
5997 const sctp_subtype_t type,
5998 void *arg,
5999 sctp_cmd_seq_t *commands)
6000{
bb33381d
DB
6001 pr_debug("%s: timer %d ignored\n", __func__, type.chunk);
6002
1da177e4
LT
6003 return SCTP_DISPOSITION_CONSUME;
6004}
6005
6006/********************************************************************
6007 * 2nd Level Abstractions
6008 ********************************************************************/
6009
6010/* Pull the SACK chunk based on the SACK header. */
6011static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk)
6012{
6013 struct sctp_sackhdr *sack;
6014 unsigned int len;
6015 __u16 num_blocks;
6016 __u16 num_dup_tsns;
6017
6018 /* Protect ourselves from reading too far into
6019 * the skb from a bogus sender.
6020 */
6021 sack = (struct sctp_sackhdr *) chunk->skb->data;
6022
6023 num_blocks = ntohs(sack->num_gap_ack_blocks);
6024 num_dup_tsns = ntohs(sack->num_dup_tsns);
6025 len = sizeof(struct sctp_sackhdr);
6026 len += (num_blocks + num_dup_tsns) * sizeof(__u32);
6027 if (len > chunk->skb->len)
6028 return NULL;
6029
6030 skb_pull(chunk->skb, len);
6031
6032 return sack;
6033}
6034
6035/* Create an ABORT packet to be sent as a response, with the specified
6036 * error causes.
6037 */
24cb81a6
EB
6038static struct sctp_packet *sctp_abort_pkt_new(struct net *net,
6039 const struct sctp_endpoint *ep,
1da177e4
LT
6040 const struct sctp_association *asoc,
6041 struct sctp_chunk *chunk,
6042 const void *payload,
6043 size_t paylen)
6044{
6045 struct sctp_packet *packet;
6046 struct sctp_chunk *abort;
6047
2ce95503 6048 packet = sctp_ootb_pkt_new(net, asoc, chunk);
1da177e4
LT
6049
6050 if (packet) {
6051 /* Make an ABORT.
6052 * The T bit will be set if the asoc is NULL.
6053 */
6054 abort = sctp_make_abort(asoc, chunk, paylen);
6055 if (!abort) {
6056 sctp_ootb_pkt_free(packet);
6057 return NULL;
6058 }
047a2428
JF
6059
6060 /* Reflect vtag if T-Bit is set */
6061 if (sctp_test_T_bit(abort))
6062 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
6063
1da177e4
LT
6064 /* Add specified error causes, i.e., payload, to the
6065 * end of the chunk.
6066 */
6067 sctp_addto_chunk(abort, paylen, payload);
6068
6069 /* Set the skb to the belonging sock for accounting. */
6070 abort->skb->sk = ep->base.sk;
6071
6072 sctp_packet_append_chunk(packet, abort);
6073
6074 }
6075
6076 return packet;
6077}
6078
6079/* Allocate a packet for responding in the OOTB conditions. */
2ce95503
EB
6080static struct sctp_packet *sctp_ootb_pkt_new(struct net *net,
6081 const struct sctp_association *asoc,
1da177e4
LT
6082 const struct sctp_chunk *chunk)
6083{
6084 struct sctp_packet *packet;
6085 struct sctp_transport *transport;
6086 __u16 sport;
6087 __u16 dport;
6088 __u32 vtag;
6089
6090 /* Get the source and destination port from the inbound packet. */
6091 sport = ntohs(chunk->sctp_hdr->dest);
6092 dport = ntohs(chunk->sctp_hdr->source);
6093
6094 /* The V-tag is going to be the same as the inbound packet if no
6095 * association exists, otherwise, use the peer's vtag.
6096 */
6097 if (asoc) {
02c4e12c
WY
6098 /* Special case the INIT-ACK as there is no peer's vtag
6099 * yet.
6100 */
cb3f837b 6101 switch (chunk->chunk_hdr->type) {
02c4e12c
WY
6102 case SCTP_CID_INIT_ACK:
6103 {
6104 sctp_initack_chunk_t *initack;
6105
6106 initack = (sctp_initack_chunk_t *)chunk->chunk_hdr;
6107 vtag = ntohl(initack->init_hdr.init_tag);
6108 break;
6109 }
6110 default:
6111 vtag = asoc->peer.i.init_tag;
6112 break;
6113 }
1da177e4
LT
6114 } else {
6115 /* Special case the INIT and stale COOKIE_ECHO as there is no
6116 * vtag yet.
6117 */
cb3f837b 6118 switch (chunk->chunk_hdr->type) {
1da177e4
LT
6119 case SCTP_CID_INIT:
6120 {
6121 sctp_init_chunk_t *init;
6122
6123 init = (sctp_init_chunk_t *)chunk->chunk_hdr;
6124 vtag = ntohl(init->init_hdr.init_tag);
6125 break;
6126 }
d808ad9a 6127 default:
1da177e4
LT
6128 vtag = ntohl(chunk->sctp_hdr->vtag);
6129 break;
6130 }
6131 }
6132
6133 /* Make a transport for the bucket, Eliza... */
89bf3450 6134 transport = sctp_transport_new(net, sctp_source(chunk), GFP_ATOMIC);
1da177e4
LT
6135 if (!transport)
6136 goto nomem;
6137
6138 /* Cache a route for the transport with the chunk's destination as
6139 * the source address.
6140 */
16b0a030 6141 sctp_transport_route(transport, (union sctp_addr *)&chunk->dest,
2ce95503 6142 sctp_sk(net->sctp.ctl_sock));
1da177e4 6143
66b91d2c
MRL
6144 packet = &transport->packet;
6145 sctp_packet_init(packet, transport, sport, dport);
6146 sctp_packet_config(packet, vtag, 0);
1da177e4
LT
6147
6148 return packet;
6149
6150nomem:
6151 return NULL;
6152}
6153
6154/* Free the packet allocated earlier for responding in the OOTB condition. */
6155void sctp_ootb_pkt_free(struct sctp_packet *packet)
6156{
6157 sctp_transport_free(packet->transport);
6158}
6159
6160/* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */
24cb81a6
EB
6161static void sctp_send_stale_cookie_err(struct net *net,
6162 const struct sctp_endpoint *ep,
1da177e4
LT
6163 const struct sctp_association *asoc,
6164 const struct sctp_chunk *chunk,
6165 sctp_cmd_seq_t *commands,
6166 struct sctp_chunk *err_chunk)
6167{
6168 struct sctp_packet *packet;
6169
6170 if (err_chunk) {
2ce95503 6171 packet = sctp_ootb_pkt_new(net, asoc, chunk);
1da177e4
LT
6172 if (packet) {
6173 struct sctp_signed_cookie *cookie;
6174
6175 /* Override the OOTB vtag from the cookie. */
6176 cookie = chunk->subh.cookie_hdr;
6177 packet->vtag = cookie->c.peer_vtag;
d808ad9a 6178
1da177e4
LT
6179 /* Set the skb to the belonging sock for accounting. */
6180 err_chunk->skb->sk = ep->base.sk;
6181 sctp_packet_append_chunk(packet, err_chunk);
6182 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
6183 SCTP_PACKET(packet));
b01a2407 6184 SCTP_INC_STATS(net, SCTP_MIB_OUTCTRLCHUNKS);
1da177e4
LT
6185 } else
6186 sctp_chunk_free (err_chunk);
6187 }
6188}
6189
6190
6191/* Process a data chunk */
6192static int sctp_eat_data(const struct sctp_association *asoc,
6193 struct sctp_chunk *chunk,
6194 sctp_cmd_seq_t *commands)
6195{
6196 sctp_datahdr_t *data_hdr;
6197 struct sctp_chunk *err;
6198 size_t datalen;
6199 sctp_verb_t deliver;
6200 int tmp;
6201 __u32 tsn;
7c3ceb4f 6202 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
049b3ff5 6203 struct sock *sk = asoc->base.sk;
24cb81a6 6204 struct net *net = sock_net(sk);
f1751c57
VY
6205 u16 ssn;
6206 u16 sid;
6207 u8 ordered = 0;
1da177e4
LT
6208
6209 data_hdr = chunk->subh.data_hdr = (sctp_datahdr_t *)chunk->skb->data;
6210 skb_pull(chunk->skb, sizeof(sctp_datahdr_t));
6211
6212 tsn = ntohl(data_hdr->tsn);
bb33381d 6213 pr_debug("%s: TSN 0x%x\n", __func__, tsn);
1da177e4
LT
6214
6215 /* ASSERT: Now skb->data is really the user data. */
6216
6217 /* Process ECN based congestion.
6218 *
6219 * Since the chunk structure is reused for all chunks within
6220 * a packet, we use ecn_ce_done to track if we've already
6221 * done CE processing for this packet.
6222 *
6223 * We need to do ECN processing even if we plan to discard the
6224 * chunk later.
6225 */
6226
2d47fd12 6227 if (asoc->peer.ecn_capable && !chunk->ecn_ce_done) {
e7487c86 6228 struct sctp_af *af = SCTP_INPUT_CB(chunk->skb)->af;
1da177e4
LT
6229 chunk->ecn_ce_done = 1;
6230
2d47fd12 6231 if (af->is_ce(sctp_gso_headskb(chunk->skb))) {
1da177e4
LT
6232 /* Do real work as sideffect. */
6233 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_CE,
6234 SCTP_U32(tsn));
6235 }
6236 }
6237
6238 tmp = sctp_tsnmap_check(&asoc->peer.tsn_map, tsn);
6239 if (tmp < 0) {
6240 /* The TSN is too high--silently discard the chunk and
6241 * count on it getting retransmitted later.
6242 */
196d6759
MB
6243 if (chunk->asoc)
6244 chunk->asoc->stats.outofseqtsns++;
1da177e4
LT
6245 return SCTP_IERROR_HIGH_TSN;
6246 } else if (tmp > 0) {
6247 /* This is a duplicate. Record it. */
6248 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_DUP, SCTP_U32(tsn));
6249 return SCTP_IERROR_DUP_TSN;
6250 }
6251
6252 /* This is a new TSN. */
6253
6254 /* Discard if there is no room in the receive window.
6255 * Actually, allow a little bit of overflow (up to a MTU).
6256 */
6257 datalen = ntohs(chunk->chunk_hdr->length);
6258 datalen -= sizeof(sctp_data_chunk_t);
6259
6260 deliver = SCTP_CMD_CHUNK_ULP;
6261
6262 /* Think about partial delivery. */
6263 if ((datalen >= asoc->rwnd) && (!asoc->ulpq.pd_mode)) {
6264
6265 /* Even if we don't accept this chunk there is
6266 * memory pressure.
6267 */
6268 sctp_add_cmd_sf(commands, SCTP_CMD_PART_DELIVER, SCTP_NULL());
6269 }
6270
d808ad9a 6271 /* Spill over rwnd a little bit. Note: While allowed, this spill over
1da177e4
LT
6272 * seems a bit troublesome in that frag_point varies based on
6273 * PMTU. In cases, such as loopback, this might be a rather
6274 * large spill over.
4d93df0a 6275 */
362d5204 6276 if ((!chunk->data_accepted) && (!asoc->rwnd || asoc->rwnd_over ||
4d93df0a 6277 (datalen > asoc->rwnd + asoc->frag_point))) {
1da177e4
LT
6278
6279 /* If this is the next TSN, consider reneging to make
6280 * room. Note: Playing nice with a confused sender. A
6281 * malicious sender can still eat up all our buffer
6282 * space and in the future we may want to detect and
6283 * do more drastic reneging.
6284 */
7c3ceb4f
NH
6285 if (sctp_tsnmap_has_gap(map) &&
6286 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
bb33381d 6287 pr_debug("%s: reneging for tsn:%u\n", __func__, tsn);
1da177e4
LT
6288 deliver = SCTP_CMD_RENEGE;
6289 } else {
bb33381d
DB
6290 pr_debug("%s: discard tsn:%u len:%zu, rwnd:%d\n",
6291 __func__, tsn, datalen, asoc->rwnd);
6292
1da177e4
LT
6293 return SCTP_IERROR_IGNORE_TSN;
6294 }
6295 }
6296
4d93df0a
NH
6297 /*
6298 * Also try to renege to limit our memory usage in the event that
6299 * we are under memory pressure
3ab224be 6300 * If we can't renege, don't worry about it, the sk_rmem_schedule
4d93df0a
NH
6301 * in sctp_ulpevent_make_rcvmsg will drop the frame if we grow our
6302 * memory usage too much
6303 */
6304 if (*sk->sk_prot_creator->memory_pressure) {
6305 if (sctp_tsnmap_has_gap(map) &&
f7010e61 6306 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
bb33381d
DB
6307 pr_debug("%s: under pressure, reneging for tsn:%u\n",
6308 __func__, tsn);
4d93df0a
NH
6309 deliver = SCTP_CMD_RENEGE;
6310 }
6311 }
6312
1da177e4
LT
6313 /*
6314 * Section 3.3.10.9 No User Data (9)
6315 *
6316 * Cause of error
6317 * ---------------
6318 * No User Data: This error cause is returned to the originator of a
6319 * DATA chunk if a received DATA chunk has no user data.
6320 */
6321 if (unlikely(0 == datalen)) {
6322 err = sctp_make_abort_no_data(asoc, chunk, tsn);
6323 if (err) {
6324 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
6325 SCTP_CHUNK(err));
6326 }
6327 /* We are going to ABORT, so we might as well stop
6328 * processing the rest of the chunks in the packet.
6329 */
cb3f837b 6330 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
8de8c873
SS
6331 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
6332 SCTP_ERROR(ECONNABORTED));
1da177e4 6333 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5be291fe 6334 SCTP_PERR(SCTP_ERROR_NO_DATA));
b01a2407
EB
6335 SCTP_INC_STATS(net, SCTP_MIB_ABORTEDS);
6336 SCTP_DEC_STATS(net, SCTP_MIB_CURRESTAB);
1da177e4
LT
6337 return SCTP_IERROR_NO_DATA;
6338 }
6339
9faa730f
SS
6340 chunk->data_accepted = 1;
6341
1da177e4
LT
6342 /* Note: Some chunks may get overcounted (if we drop) or overcounted
6343 * if we renege and the chunk arrives again.
6344 */
196d6759 6345 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED) {
b01a2407 6346 SCTP_INC_STATS(net, SCTP_MIB_INUNORDERCHUNKS);
196d6759
MB
6347 if (chunk->asoc)
6348 chunk->asoc->stats.iuodchunks++;
6349 } else {
b01a2407 6350 SCTP_INC_STATS(net, SCTP_MIB_INORDERCHUNKS);
196d6759
MB
6351 if (chunk->asoc)
6352 chunk->asoc->stats.iodchunks++;
f1751c57
VY
6353 ordered = 1;
6354 }
1da177e4
LT
6355
6356 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
6357 *
6358 * If an endpoint receive a DATA chunk with an invalid stream
6359 * identifier, it shall acknowledge the reception of the DATA chunk
6360 * following the normal procedure, immediately send an ERROR chunk
6361 * with cause set to "Invalid Stream Identifier" (See Section 3.3.10)
6362 * and discard the DATA chunk.
6363 */
f1751c57
VY
6364 sid = ntohs(data_hdr->stream);
6365 if (sid >= asoc->c.sinit_max_instreams) {
3888e9ef
VY
6366 /* Mark tsn as received even though we drop it */
6367 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_TSN, SCTP_U32(tsn));
6368
1da177e4
LT
6369 err = sctp_make_op_error(asoc, chunk, SCTP_ERROR_INV_STRM,
6370 &data_hdr->stream,
6383cfb3
VY
6371 sizeof(data_hdr->stream),
6372 sizeof(u16));
1da177e4
LT
6373 if (err)
6374 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
6375 SCTP_CHUNK(err));
6376 return SCTP_IERROR_BAD_STREAM;
6377 }
6378
f1751c57
VY
6379 /* Check to see if the SSN is possible for this TSN.
6380 * The biggest gap we can record is 4K wide. Since SSNs wrap
6381 * at an unsigned short, there is no way that an SSN can
6382 * wrap and for a valid TSN. We can simply check if the current
6383 * SSN is smaller then the next expected one. If it is, it wrapped
6384 * and is invalid.
6385 */
6386 ssn = ntohs(data_hdr->ssn);
a8386317 6387 if (ordered && SSN_lt(ssn, sctp_ssn_peek(asoc->stream, in, sid)))
f1751c57 6388 return SCTP_IERROR_PROTO_VIOLATION;
f1751c57 6389
1da177e4
LT
6390 /* Send the data up to the user. Note: Schedule the
6391 * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK
6392 * chunk needs the updated rwnd.
6393 */
6394 sctp_add_cmd_sf(commands, deliver, SCTP_CHUNK(chunk));
6395
6396 return SCTP_IERROR_NO_ERROR;
6397}