ia64/linux-2.6.18-xen.hg

view net/sctp/sm_statefuns.c @ 871:9cbcc9008446

xen/x86: don't initialize cpu_data[]'s apicid field on generic code

Afaict, this is not only redundant with the intialization done in
drivers/xen/core/smpboot.c, but actually results - at least for
secondary CPUs - in the Xen-specific value written to be later
overwritten with whatever the generic code determines (with no
guarantee that the two values are identical).

Signed-off-by: Jan Beulich <jbeulich@novell.com>
author Keir Fraser <keir.fraser@citrix.com>
date Thu May 14 10:09:15 2009 +0100 (2009-05-14)
parents 831230e53067
children
line source
1 /* SCTP kernel reference Implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999-2000 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 * Copyright (c) 2001-2002 Intel Corp.
6 * Copyright (c) 2002 Nokia Corp.
7 *
8 * This file is part of the SCTP kernel reference Implementation
9 *
10 * This is part of the SCTP Linux Kernel Reference Implementation.
11 *
12 * These are the state functions for the state machine.
13 *
14 * The SCTP reference implementation is free software;
15 * you can redistribute it and/or modify it under the terms of
16 * the GNU General Public License as published by
17 * the Free Software Foundation; either version 2, or (at your option)
18 * any later version.
19 *
20 * The SCTP reference implementation is distributed in the hope that it
21 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
22 * ************************
23 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
24 * See the GNU General Public License for more details.
25 *
26 * You should have received a copy of the GNU General Public License
27 * along with GNU CC; see the file COPYING. If not, write to
28 * the Free Software Foundation, 59 Temple Place - Suite 330,
29 * Boston, MA 02111-1307, USA.
30 *
31 * Please send any bug reports or fixes you make to the
32 * email address(es):
33 * lksctp developers <lksctp-developers@lists.sourceforge.net>
34 *
35 * Or submit a bug report through the following website:
36 * http://www.sf.net/projects/lksctp
37 *
38 * Written or modified by:
39 * La Monte H.P. Yarroll <piggy@acm.org>
40 * Karl Knutson <karl@athena.chicago.il.us>
41 * Mathew Kotowsky <kotowsky@sctp.org>
42 * Sridhar Samudrala <samudrala@us.ibm.com>
43 * Jon Grimm <jgrimm@us.ibm.com>
44 * Hui Huang <hui.huang@nokia.com>
45 * Dajiang Zhang <dajiang.zhang@nokia.com>
46 * Daisy Chang <daisyc@us.ibm.com>
47 * Ardelle Fan <ardelle.fan@intel.com>
48 * Ryan Layer <rmlayer@us.ibm.com>
49 * Kevin Gao <kevin.gao@intel.com>
50 *
51 * Any bugs reported given to us we will try to fix... any fixes shared will
52 * be incorporated into the next SCTP release.
53 */
55 #include <linux/types.h>
56 #include <linux/kernel.h>
57 #include <linux/ip.h>
58 #include <linux/ipv6.h>
59 #include <linux/net.h>
60 #include <linux/inet.h>
61 #include <net/sock.h>
62 #include <net/inet_ecn.h>
63 #include <linux/skbuff.h>
64 #include <net/sctp/sctp.h>
65 #include <net/sctp/sm.h>
66 #include <net/sctp/structs.h>
68 static struct sctp_packet *sctp_abort_pkt_new(const struct sctp_endpoint *ep,
69 const struct sctp_association *asoc,
70 struct sctp_chunk *chunk,
71 const void *payload,
72 size_t paylen);
73 static int sctp_eat_data(const struct sctp_association *asoc,
74 struct sctp_chunk *chunk,
75 sctp_cmd_seq_t *commands);
76 static struct sctp_packet *sctp_ootb_pkt_new(const struct sctp_association *asoc,
77 const struct sctp_chunk *chunk);
78 static void sctp_send_stale_cookie_err(const struct sctp_endpoint *ep,
79 const struct sctp_association *asoc,
80 const struct sctp_chunk *chunk,
81 sctp_cmd_seq_t *commands,
82 struct sctp_chunk *err_chunk);
83 static sctp_disposition_t sctp_sf_do_5_2_6_stale(const struct sctp_endpoint *ep,
84 const struct sctp_association *asoc,
85 const sctp_subtype_t type,
86 void *arg,
87 sctp_cmd_seq_t *commands);
88 static sctp_disposition_t sctp_sf_shut_8_4_5(const struct sctp_endpoint *ep,
89 const struct sctp_association *asoc,
90 const sctp_subtype_t type,
91 void *arg,
92 sctp_cmd_seq_t *commands);
93 static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk);
95 static sctp_disposition_t sctp_stop_t1_and_abort(sctp_cmd_seq_t *commands,
96 __u16 error, int sk_err,
97 const struct sctp_association *asoc,
98 struct sctp_transport *transport);
100 static sctp_disposition_t sctp_sf_violation_chunklen(
101 const struct sctp_endpoint *ep,
102 const struct sctp_association *asoc,
103 const sctp_subtype_t type,
104 void *arg,
105 sctp_cmd_seq_t *commands);
107 /* Small helper function that checks if the chunk length
108 * is of the appropriate length. The 'required_length' argument
109 * is set to be the size of a specific chunk we are testing.
110 * Return Values: 1 = Valid length
111 * 0 = Invalid length
112 *
113 */
114 static inline int
115 sctp_chunk_length_valid(struct sctp_chunk *chunk,
116 __u16 required_length)
117 {
118 __u16 chunk_length = ntohs(chunk->chunk_hdr->length);
120 if (unlikely(chunk_length < required_length))
121 return 0;
123 return 1;
124 }
126 /**********************************************************
127 * These are the state functions for handling chunk events.
128 **********************************************************/
130 /*
131 * Process the final SHUTDOWN COMPLETE.
132 *
133 * Section: 4 (C) (diagram), 9.2
134 * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify
135 * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be
136 * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint
137 * should stop the T2-shutdown timer and remove all knowledge of the
138 * association (and thus the association enters the CLOSED state).
139 *
140 * Verification Tag: 8.5.1(C), sctpimpguide 2.41.
141 * C) Rules for packet carrying SHUTDOWN COMPLETE:
142 * ...
143 * - The receiver of a SHUTDOWN COMPLETE shall accept the packet
144 * if the Verification Tag field of the packet matches its own tag and
145 * the T bit is not set
146 * OR
147 * it is set to its peer's tag and the T bit is set in the Chunk
148 * Flags.
149 * Otherwise, the receiver MUST silently discard the packet
150 * and take no further action. An endpoint MUST ignore the
151 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
152 *
153 * Inputs
154 * (endpoint, asoc, chunk)
155 *
156 * Outputs
157 * (asoc, reply_msg, msg_up, timers, counters)
158 *
159 * The return value is the disposition of the chunk.
160 */
161 sctp_disposition_t sctp_sf_do_4_C(const struct sctp_endpoint *ep,
162 const struct sctp_association *asoc,
163 const sctp_subtype_t type,
164 void *arg,
165 sctp_cmd_seq_t *commands)
166 {
167 struct sctp_chunk *chunk = arg;
168 struct sctp_ulpevent *ev;
170 /* RFC 2960 6.10 Bundling
171 *
172 * An endpoint MUST NOT bundle INIT, INIT ACK or
173 * SHUTDOWN COMPLETE with any other chunks.
174 */
175 if (!chunk->singleton)
176 return SCTP_DISPOSITION_VIOLATION;
178 if (!sctp_vtag_verify_either(chunk, asoc))
179 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
181 /* RFC 2960 10.2 SCTP-to-ULP
182 *
183 * H) SHUTDOWN COMPLETE notification
184 *
185 * When SCTP completes the shutdown procedures (section 9.2) this
186 * notification is passed to the upper layer.
187 */
188 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
189 0, 0, 0, GFP_ATOMIC);
190 if (!ev)
191 goto nomem;
193 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
195 /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint
196 * will verify that it is in SHUTDOWN-ACK-SENT state, if it is
197 * not the chunk should be discarded. If the endpoint is in
198 * the SHUTDOWN-ACK-SENT state the endpoint should stop the
199 * T2-shutdown timer and remove all knowledge of the
200 * association (and thus the association enters the CLOSED
201 * state).
202 */
203 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
204 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
206 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
207 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
209 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
210 SCTP_STATE(SCTP_STATE_CLOSED));
212 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
213 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
215 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
217 return SCTP_DISPOSITION_DELETE_TCB;
219 nomem:
220 return SCTP_DISPOSITION_NOMEM;
221 }
223 /*
224 * Respond to a normal INIT chunk.
225 * We are the side that is being asked for an association.
226 *
227 * Section: 5.1 Normal Establishment of an Association, B
228 * B) "Z" shall respond immediately with an INIT ACK chunk. The
229 * destination IP address of the INIT ACK MUST be set to the source
230 * IP address of the INIT to which this INIT ACK is responding. In
231 * the response, besides filling in other parameters, "Z" must set the
232 * Verification Tag field to Tag_A, and also provide its own
233 * Verification Tag (Tag_Z) in the Initiate Tag field.
234 *
235 * Verification Tag: Must be 0.
236 *
237 * Inputs
238 * (endpoint, asoc, chunk)
239 *
240 * Outputs
241 * (asoc, reply_msg, msg_up, timers, counters)
242 *
243 * The return value is the disposition of the chunk.
244 */
245 sctp_disposition_t sctp_sf_do_5_1B_init(const struct sctp_endpoint *ep,
246 const struct sctp_association *asoc,
247 const sctp_subtype_t type,
248 void *arg,
249 sctp_cmd_seq_t *commands)
250 {
251 struct sctp_chunk *chunk = arg;
252 struct sctp_chunk *repl;
253 struct sctp_association *new_asoc;
254 struct sctp_chunk *err_chunk;
255 struct sctp_packet *packet;
256 sctp_unrecognized_param_t *unk_param;
257 struct sock *sk;
258 int len;
260 /* 6.10 Bundling
261 * An endpoint MUST NOT bundle INIT, INIT ACK or
262 * SHUTDOWN COMPLETE with any other chunks.
263 *
264 * IG Section 2.11.2
265 * Furthermore, we require that the receiver of an INIT chunk MUST
266 * enforce these rules by silently discarding an arriving packet
267 * with an INIT chunk that is bundled with other chunks.
268 */
269 if (!chunk->singleton)
270 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
272 /* If the packet is an OOTB packet which is temporarily on the
273 * control endpoint, respond with an ABORT.
274 */
275 if (ep == sctp_sk((sctp_get_ctl_sock()))->ep)
276 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
278 sk = ep->base.sk;
279 /* If the endpoint is not listening or if the number of associations
280 * on the TCP-style socket exceed the max backlog, respond with an
281 * ABORT.
282 */
283 if (!sctp_sstate(sk, LISTENING) ||
284 (sctp_style(sk, TCP) &&
285 sk_acceptq_is_full(sk)))
286 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
288 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
289 * Tag.
290 */
291 if (chunk->sctp_hdr->vtag != 0)
292 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
294 /* Make sure that the INIT chunk has a valid length.
295 * Normally, this would cause an ABORT with a Protocol Violation
296 * error, but since we don't have an association, we'll
297 * just discard the packet.
298 */
299 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
300 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
302 /* Verify the INIT chunk before processing it. */
303 err_chunk = NULL;
304 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
305 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
306 &err_chunk)) {
307 /* This chunk contains fatal error. It is to be discarded.
308 * Send an ABORT, with causes if there is any.
309 */
310 if (err_chunk) {
311 packet = sctp_abort_pkt_new(ep, asoc, arg,
312 (__u8 *)(err_chunk->chunk_hdr) +
313 sizeof(sctp_chunkhdr_t),
314 ntohs(err_chunk->chunk_hdr->length) -
315 sizeof(sctp_chunkhdr_t));
317 sctp_chunk_free(err_chunk);
319 if (packet) {
320 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
321 SCTP_PACKET(packet));
322 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
323 return SCTP_DISPOSITION_CONSUME;
324 } else {
325 return SCTP_DISPOSITION_NOMEM;
326 }
327 } else {
328 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg,
329 commands);
330 }
331 }
333 /* Grab the INIT header. */
334 chunk->subh.init_hdr = (sctp_inithdr_t *)chunk->skb->data;
336 /* Tag the variable length parameters. */
337 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
339 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
340 if (!new_asoc)
341 goto nomem;
343 /* The call, sctp_process_init(), can fail on memory allocation. */
344 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
345 sctp_source(chunk),
346 (sctp_init_chunk_t *)chunk->chunk_hdr,
347 GFP_ATOMIC))
348 goto nomem_init;
350 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
352 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
354 /* If there are errors need to be reported for unknown parameters,
355 * make sure to reserve enough room in the INIT ACK for them.
356 */
357 len = 0;
358 if (err_chunk)
359 len = ntohs(err_chunk->chunk_hdr->length) -
360 sizeof(sctp_chunkhdr_t);
362 if (sctp_assoc_set_bind_addr_from_ep(new_asoc, GFP_ATOMIC) < 0)
363 goto nomem_ack;
365 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
366 if (!repl)
367 goto nomem_ack;
369 /* If there are errors need to be reported for unknown parameters,
370 * include them in the outgoing INIT ACK as "Unrecognized parameter"
371 * parameter.
372 */
373 if (err_chunk) {
374 /* Get the "Unrecognized parameter" parameter(s) out of the
375 * ERROR chunk generated by sctp_verify_init(). Since the
376 * error cause code for "unknown parameter" and the
377 * "Unrecognized parameter" type is the same, we can
378 * construct the parameters in INIT ACK by copying the
379 * ERROR causes over.
380 */
381 unk_param = (sctp_unrecognized_param_t *)
382 ((__u8 *)(err_chunk->chunk_hdr) +
383 sizeof(sctp_chunkhdr_t));
384 /* Replace the cause code with the "Unrecognized parameter"
385 * parameter type.
386 */
387 sctp_addto_chunk(repl, len, unk_param);
388 sctp_chunk_free(err_chunk);
389 }
391 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
393 /*
394 * Note: After sending out INIT ACK with the State Cookie parameter,
395 * "Z" MUST NOT allocate any resources, nor keep any states for the
396 * new association. Otherwise, "Z" will be vulnerable to resource
397 * attacks.
398 */
399 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
401 return SCTP_DISPOSITION_DELETE_TCB;
403 nomem_ack:
404 if (err_chunk)
405 sctp_chunk_free(err_chunk);
406 nomem_init:
407 sctp_association_free(new_asoc);
408 nomem:
409 return SCTP_DISPOSITION_NOMEM;
410 }
412 /*
413 * Respond to a normal INIT ACK chunk.
414 * We are the side that is initiating the association.
415 *
416 * Section: 5.1 Normal Establishment of an Association, C
417 * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init
418 * timer and leave COOKIE-WAIT state. "A" shall then send the State
419 * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start
420 * the T1-cookie timer, and enter the COOKIE-ECHOED state.
421 *
422 * Note: The COOKIE ECHO chunk can be bundled with any pending outbound
423 * DATA chunks, but it MUST be the first chunk in the packet and
424 * until the COOKIE ACK is returned the sender MUST NOT send any
425 * other packets to the peer.
426 *
427 * Verification Tag: 3.3.3
428 * If the value of the Initiate Tag in a received INIT ACK chunk is
429 * found to be 0, the receiver MUST treat it as an error and close the
430 * association by transmitting an ABORT.
431 *
432 * Inputs
433 * (endpoint, asoc, chunk)
434 *
435 * Outputs
436 * (asoc, reply_msg, msg_up, timers, counters)
437 *
438 * The return value is the disposition of the chunk.
439 */
440 sctp_disposition_t sctp_sf_do_5_1C_ack(const struct sctp_endpoint *ep,
441 const struct sctp_association *asoc,
442 const sctp_subtype_t type,
443 void *arg,
444 sctp_cmd_seq_t *commands)
445 {
446 struct sctp_chunk *chunk = arg;
447 sctp_init_chunk_t *initchunk;
448 __u32 init_tag;
449 struct sctp_chunk *err_chunk;
450 struct sctp_packet *packet;
451 __u16 error;
453 if (!sctp_vtag_verify(chunk, asoc))
454 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
456 /* Make sure that the INIT-ACK chunk has a valid length */
457 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_initack_chunk_t)))
458 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
459 commands);
460 /* 6.10 Bundling
461 * An endpoint MUST NOT bundle INIT, INIT ACK or
462 * SHUTDOWN COMPLETE with any other chunks.
463 */
464 if (!chunk->singleton)
465 return SCTP_DISPOSITION_VIOLATION;
467 /* Grab the INIT header. */
468 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
470 init_tag = ntohl(chunk->subh.init_hdr->init_tag);
472 /* Verification Tag: 3.3.3
473 * If the value of the Initiate Tag in a received INIT ACK
474 * chunk is found to be 0, the receiver MUST treat it as an
475 * error and close the association by transmitting an ABORT.
476 */
477 if (!init_tag) {
478 struct sctp_chunk *reply = sctp_make_abort(asoc, chunk, 0);
479 if (!reply)
480 goto nomem;
482 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
483 return sctp_stop_t1_and_abort(commands, SCTP_ERROR_INV_PARAM,
484 ECONNREFUSED, asoc,
485 chunk->transport);
486 }
488 /* Verify the INIT chunk before processing it. */
489 err_chunk = NULL;
490 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
491 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
492 &err_chunk)) {
494 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
496 /* This chunk contains fatal error. It is to be discarded.
497 * Send an ABORT, with causes if there is any.
498 */
499 if (err_chunk) {
500 packet = sctp_abort_pkt_new(ep, asoc, arg,
501 (__u8 *)(err_chunk->chunk_hdr) +
502 sizeof(sctp_chunkhdr_t),
503 ntohs(err_chunk->chunk_hdr->length) -
504 sizeof(sctp_chunkhdr_t));
506 sctp_chunk_free(err_chunk);
508 if (packet) {
509 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
510 SCTP_PACKET(packet));
511 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
512 error = SCTP_ERROR_INV_PARAM;
513 } else {
514 error = SCTP_ERROR_NO_RESOURCE;
515 }
516 } else {
517 sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
518 error = SCTP_ERROR_INV_PARAM;
519 }
520 return sctp_stop_t1_and_abort(commands, error, ECONNREFUSED,
521 asoc, chunk->transport);
522 }
524 /* Tag the variable length parameters. Note that we never
525 * convert the parameters in an INIT chunk.
526 */
527 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
529 initchunk = (sctp_init_chunk_t *) chunk->chunk_hdr;
531 sctp_add_cmd_sf(commands, SCTP_CMD_PEER_INIT,
532 SCTP_PEER_INIT(initchunk));
534 /* Reset init error count upon receipt of INIT-ACK. */
535 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
537 /* 5.1 C) "A" shall stop the T1-init timer and leave
538 * COOKIE-WAIT state. "A" shall then ... start the T1-cookie
539 * timer, and enter the COOKIE-ECHOED state.
540 */
541 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
542 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
543 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
544 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
545 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
546 SCTP_STATE(SCTP_STATE_COOKIE_ECHOED));
548 /* 5.1 C) "A" shall then send the State Cookie received in the
549 * INIT ACK chunk in a COOKIE ECHO chunk, ...
550 */
551 /* If there is any errors to report, send the ERROR chunk generated
552 * for unknown parameters as well.
553 */
554 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_COOKIE_ECHO,
555 SCTP_CHUNK(err_chunk));
557 return SCTP_DISPOSITION_CONSUME;
559 nomem:
560 return SCTP_DISPOSITION_NOMEM;
561 }
563 /*
564 * Respond to a normal COOKIE ECHO chunk.
565 * We are the side that is being asked for an association.
566 *
567 * Section: 5.1 Normal Establishment of an Association, D
568 * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply
569 * with a COOKIE ACK chunk after building a TCB and moving to
570 * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with
571 * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK
572 * chunk MUST be the first chunk in the packet.
573 *
574 * IMPLEMENTATION NOTE: An implementation may choose to send the
575 * Communication Up notification to the SCTP user upon reception
576 * of a valid COOKIE ECHO chunk.
577 *
578 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
579 * D) Rules for packet carrying a COOKIE ECHO
580 *
581 * - When sending a COOKIE ECHO, the endpoint MUST use the value of the
582 * Initial Tag received in the INIT ACK.
583 *
584 * - The receiver of a COOKIE ECHO follows the procedures in Section 5.
585 *
586 * Inputs
587 * (endpoint, asoc, chunk)
588 *
589 * Outputs
590 * (asoc, reply_msg, msg_up, timers, counters)
591 *
592 * The return value is the disposition of the chunk.
593 */
594 sctp_disposition_t sctp_sf_do_5_1D_ce(const struct sctp_endpoint *ep,
595 const struct sctp_association *asoc,
596 const sctp_subtype_t type, void *arg,
597 sctp_cmd_seq_t *commands)
598 {
599 struct sctp_chunk *chunk = arg;
600 struct sctp_association *new_asoc;
601 sctp_init_chunk_t *peer_init;
602 struct sctp_chunk *repl;
603 struct sctp_ulpevent *ev;
604 int error = 0;
605 struct sctp_chunk *err_chk_p;
607 /* If the packet is an OOTB packet which is temporarily on the
608 * control endpoint, respond with an ABORT.
609 */
610 if (ep == sctp_sk((sctp_get_ctl_sock()))->ep)
611 return sctp_sf_ootb(ep, asoc, type, arg, commands);
613 /* Make sure that the COOKIE_ECHO chunk has a valid length.
614 * In this case, we check that we have enough for at least a
615 * chunk header. More detailed verification is done
616 * in sctp_unpack_cookie().
617 */
618 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
619 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
621 /* "Decode" the chunk. We have no optional parameters so we
622 * are in good shape.
623 */
624 chunk->subh.cookie_hdr =
625 (struct sctp_signed_cookie *)chunk->skb->data;
626 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
627 sizeof(sctp_chunkhdr_t)))
628 goto nomem;
630 /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
631 * "Z" will reply with a COOKIE ACK chunk after building a TCB
632 * and moving to the ESTABLISHED state.
633 */
634 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
635 &err_chk_p);
637 /* FIXME:
638 * If the re-build failed, what is the proper error path
639 * from here?
640 *
641 * [We should abort the association. --piggy]
642 */
643 if (!new_asoc) {
644 /* FIXME: Several errors are possible. A bad cookie should
645 * be silently discarded, but think about logging it too.
646 */
647 switch (error) {
648 case -SCTP_IERROR_NOMEM:
649 goto nomem;
651 case -SCTP_IERROR_STALE_COOKIE:
652 sctp_send_stale_cookie_err(ep, asoc, chunk, commands,
653 err_chk_p);
654 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
656 case -SCTP_IERROR_BAD_SIG:
657 default:
658 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
659 };
660 }
662 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
663 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
664 SCTP_STATE(SCTP_STATE_ESTABLISHED));
665 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
666 SCTP_INC_STATS(SCTP_MIB_PASSIVEESTABS);
667 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
669 if (new_asoc->autoclose)
670 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
671 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
673 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
675 /* Re-build the bind address for the association is done in
676 * the sctp_unpack_cookie() already.
677 */
678 /* This is a brand-new association, so these are not yet side
679 * effects--it is safe to run them here.
680 */
681 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
683 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
684 &chunk->subh.cookie_hdr->c.peer_addr,
685 peer_init, GFP_ATOMIC))
686 goto nomem_init;
688 repl = sctp_make_cookie_ack(new_asoc, chunk);
689 if (!repl)
690 goto nomem_repl;
692 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
694 /* RFC 2960 5.1 Normal Establishment of an Association
695 *
696 * D) IMPLEMENTATION NOTE: An implementation may choose to
697 * send the Communication Up notification to the SCTP user
698 * upon reception of a valid COOKIE ECHO chunk.
699 */
700 ev = sctp_ulpevent_make_assoc_change(new_asoc, 0, SCTP_COMM_UP, 0,
701 new_asoc->c.sinit_num_ostreams,
702 new_asoc->c.sinit_max_instreams,
703 GFP_ATOMIC);
704 if (!ev)
705 goto nomem_ev;
707 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
709 /* Sockets API Draft Section 5.3.1.6
710 * When a peer sends a Adaption Layer Indication parameter , SCTP
711 * delivers this notification to inform the application that of the
712 * peers requested adaption layer.
713 */
714 if (new_asoc->peer.adaption_ind) {
715 ev = sctp_ulpevent_make_adaption_indication(new_asoc,
716 GFP_ATOMIC);
717 if (!ev)
718 goto nomem_ev;
720 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
721 SCTP_ULPEVENT(ev));
722 }
724 return SCTP_DISPOSITION_CONSUME;
726 nomem_ev:
727 sctp_chunk_free(repl);
728 nomem_repl:
729 nomem_init:
730 sctp_association_free(new_asoc);
731 nomem:
732 return SCTP_DISPOSITION_NOMEM;
733 }
735 /*
736 * Respond to a normal COOKIE ACK chunk.
737 * We are the side that is being asked for an association.
738 *
739 * RFC 2960 5.1 Normal Establishment of an Association
740 *
741 * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the
742 * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie
743 * timer. It may also notify its ULP about the successful
744 * establishment of the association with a Communication Up
745 * notification (see Section 10).
746 *
747 * Verification Tag:
748 * Inputs
749 * (endpoint, asoc, chunk)
750 *
751 * Outputs
752 * (asoc, reply_msg, msg_up, timers, counters)
753 *
754 * The return value is the disposition of the chunk.
755 */
756 sctp_disposition_t sctp_sf_do_5_1E_ca(const struct sctp_endpoint *ep,
757 const struct sctp_association *asoc,
758 const sctp_subtype_t type, void *arg,
759 sctp_cmd_seq_t *commands)
760 {
761 struct sctp_chunk *chunk = arg;
762 struct sctp_ulpevent *ev;
764 if (!sctp_vtag_verify(chunk, asoc))
765 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
767 /* Verify that the chunk length for the COOKIE-ACK is OK.
768 * If we don't do this, any bundled chunks may be junked.
769 */
770 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
771 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
772 commands);
774 /* Reset init error count upon receipt of COOKIE-ACK,
775 * to avoid problems with the managemement of this
776 * counter in stale cookie situations when a transition back
777 * from the COOKIE-ECHOED state to the COOKIE-WAIT
778 * state is performed.
779 */
780 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_RESET, SCTP_NULL());
782 /* RFC 2960 5.1 Normal Establishment of an Association
783 *
784 * E) Upon reception of the COOKIE ACK, endpoint "A" will move
785 * from the COOKIE-ECHOED state to the ESTABLISHED state,
786 * stopping the T1-cookie timer.
787 */
788 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
789 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
790 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
791 SCTP_STATE(SCTP_STATE_ESTABLISHED));
792 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
793 SCTP_INC_STATS(SCTP_MIB_ACTIVEESTABS);
794 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
795 if (asoc->autoclose)
796 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
797 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
798 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
800 /* It may also notify its ULP about the successful
801 * establishment of the association with a Communication Up
802 * notification (see Section 10).
803 */
804 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP,
805 0, asoc->c.sinit_num_ostreams,
806 asoc->c.sinit_max_instreams,
807 GFP_ATOMIC);
809 if (!ev)
810 goto nomem;
812 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
814 /* Sockets API Draft Section 5.3.1.6
815 * When a peer sends a Adaption Layer Indication parameter , SCTP
816 * delivers this notification to inform the application that of the
817 * peers requested adaption layer.
818 */
819 if (asoc->peer.adaption_ind) {
820 ev = sctp_ulpevent_make_adaption_indication(asoc, GFP_ATOMIC);
821 if (!ev)
822 goto nomem;
824 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
825 SCTP_ULPEVENT(ev));
826 }
828 return SCTP_DISPOSITION_CONSUME;
829 nomem:
830 return SCTP_DISPOSITION_NOMEM;
831 }
833 /* Generate and sendout a heartbeat packet. */
834 static sctp_disposition_t sctp_sf_heartbeat(const struct sctp_endpoint *ep,
835 const struct sctp_association *asoc,
836 const sctp_subtype_t type,
837 void *arg,
838 sctp_cmd_seq_t *commands)
839 {
840 struct sctp_transport *transport = (struct sctp_transport *) arg;
841 struct sctp_chunk *reply;
842 sctp_sender_hb_info_t hbinfo;
843 size_t paylen = 0;
845 hbinfo.param_hdr.type = SCTP_PARAM_HEARTBEAT_INFO;
846 hbinfo.param_hdr.length = htons(sizeof(sctp_sender_hb_info_t));
847 hbinfo.daddr = transport->ipaddr;
848 hbinfo.sent_at = jiffies;
849 hbinfo.hb_nonce = transport->hb_nonce;
851 /* Send a heartbeat to our peer. */
852 paylen = sizeof(sctp_sender_hb_info_t);
853 reply = sctp_make_heartbeat(asoc, transport, &hbinfo, paylen);
854 if (!reply)
855 return SCTP_DISPOSITION_NOMEM;
857 /* Set rto_pending indicating that an RTT measurement
858 * is started with this heartbeat chunk.
859 */
860 sctp_add_cmd_sf(commands, SCTP_CMD_RTO_PENDING,
861 SCTP_TRANSPORT(transport));
863 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
864 return SCTP_DISPOSITION_CONSUME;
865 }
867 /* Generate a HEARTBEAT packet on the given transport. */
868 sctp_disposition_t sctp_sf_sendbeat_8_3(const struct sctp_endpoint *ep,
869 const struct sctp_association *asoc,
870 const sctp_subtype_t type,
871 void *arg,
872 sctp_cmd_seq_t *commands)
873 {
874 struct sctp_transport *transport = (struct sctp_transport *) arg;
876 if (asoc->overall_error_count >= asoc->max_retrans) {
877 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
878 SCTP_ERROR(ETIMEDOUT));
879 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
880 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
881 SCTP_U32(SCTP_ERROR_NO_ERROR));
882 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
883 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
884 return SCTP_DISPOSITION_DELETE_TCB;
885 }
887 /* Section 3.3.5.
888 * The Sender-specific Heartbeat Info field should normally include
889 * information about the sender's current time when this HEARTBEAT
890 * chunk is sent and the destination transport address to which this
891 * HEARTBEAT is sent (see Section 8.3).
892 */
894 if (transport->param_flags & SPP_HB_ENABLE) {
895 if (SCTP_DISPOSITION_NOMEM ==
896 sctp_sf_heartbeat(ep, asoc, type, arg,
897 commands))
898 return SCTP_DISPOSITION_NOMEM;
899 /* Set transport error counter and association error counter
900 * when sending heartbeat.
901 */
902 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_RESET,
903 SCTP_TRANSPORT(transport));
904 }
905 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMER_UPDATE,
906 SCTP_TRANSPORT(transport));
908 return SCTP_DISPOSITION_CONSUME;
909 }
911 /*
912 * Process an heartbeat request.
913 *
914 * Section: 8.3 Path Heartbeat
915 * The receiver of the HEARTBEAT should immediately respond with a
916 * HEARTBEAT ACK that contains the Heartbeat Information field copied
917 * from the received HEARTBEAT chunk.
918 *
919 * Verification Tag: 8.5 Verification Tag [Normal verification]
920 * When receiving an SCTP packet, the endpoint MUST ensure that the
921 * value in the Verification Tag field of the received SCTP packet
922 * matches its own Tag. If the received Verification Tag value does not
923 * match the receiver's own tag value, the receiver shall silently
924 * discard the packet and shall not process it any further except for
925 * those cases listed in Section 8.5.1 below.
926 *
927 * Inputs
928 * (endpoint, asoc, chunk)
929 *
930 * Outputs
931 * (asoc, reply_msg, msg_up, timers, counters)
932 *
933 * The return value is the disposition of the chunk.
934 */
935 sctp_disposition_t sctp_sf_beat_8_3(const struct sctp_endpoint *ep,
936 const struct sctp_association *asoc,
937 const sctp_subtype_t type,
938 void *arg,
939 sctp_cmd_seq_t *commands)
940 {
941 struct sctp_chunk *chunk = arg;
942 struct sctp_chunk *reply;
943 size_t paylen = 0;
945 if (!sctp_vtag_verify(chunk, asoc))
946 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
948 /* Make sure that the HEARTBEAT chunk has a valid length. */
949 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t)))
950 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
951 commands);
953 /* 8.3 The receiver of the HEARTBEAT should immediately
954 * respond with a HEARTBEAT ACK that contains the Heartbeat
955 * Information field copied from the received HEARTBEAT chunk.
956 */
957 chunk->subh.hb_hdr = (sctp_heartbeathdr_t *) chunk->skb->data;
958 paylen = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
959 if (!pskb_pull(chunk->skb, paylen))
960 goto nomem;
962 reply = sctp_make_heartbeat_ack(asoc, chunk,
963 chunk->subh.hb_hdr, paylen);
964 if (!reply)
965 goto nomem;
967 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
968 return SCTP_DISPOSITION_CONSUME;
970 nomem:
971 return SCTP_DISPOSITION_NOMEM;
972 }
974 /*
975 * Process the returning HEARTBEAT ACK.
976 *
977 * Section: 8.3 Path Heartbeat
978 * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT
979 * should clear the error counter of the destination transport
980 * address to which the HEARTBEAT was sent, and mark the destination
981 * transport address as active if it is not so marked. The endpoint may
982 * optionally report to the upper layer when an inactive destination
983 * address is marked as active due to the reception of the latest
984 * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also
985 * clear the association overall error count as well (as defined
986 * in section 8.1).
987 *
988 * The receiver of the HEARTBEAT ACK should also perform an RTT
989 * measurement for that destination transport address using the time
990 * value carried in the HEARTBEAT ACK chunk.
991 *
992 * Verification Tag: 8.5 Verification Tag [Normal verification]
993 *
994 * Inputs
995 * (endpoint, asoc, chunk)
996 *
997 * Outputs
998 * (asoc, reply_msg, msg_up, timers, counters)
999 *
1000 * The return value is the disposition of the chunk.
1001 */
1002 sctp_disposition_t sctp_sf_backbeat_8_3(const struct sctp_endpoint *ep,
1003 const struct sctp_association *asoc,
1004 const sctp_subtype_t type,
1005 void *arg,
1006 sctp_cmd_seq_t *commands)
1008 struct sctp_chunk *chunk = arg;
1009 union sctp_addr from_addr;
1010 struct sctp_transport *link;
1011 sctp_sender_hb_info_t *hbinfo;
1012 unsigned long max_interval;
1014 if (!sctp_vtag_verify(chunk, asoc))
1015 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1017 /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */
1018 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_heartbeat_chunk_t)))
1019 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1020 commands);
1022 hbinfo = (sctp_sender_hb_info_t *) chunk->skb->data;
1023 /* Make sure that the length of the parameter is what we expect */
1024 if (ntohs(hbinfo->param_hdr.length) !=
1025 sizeof(sctp_sender_hb_info_t)) {
1026 return SCTP_DISPOSITION_DISCARD;
1029 from_addr = hbinfo->daddr;
1030 link = sctp_assoc_lookup_paddr(asoc, &from_addr);
1032 /* This should never happen, but lets log it if so. */
1033 if (unlikely(!link)) {
1034 if (from_addr.sa.sa_family == AF_INET6) {
1035 printk(KERN_WARNING
1036 "%s association %p could not find address "
1037 NIP6_FMT "\n",
1038 __FUNCTION__,
1039 asoc,
1040 NIP6(from_addr.v6.sin6_addr));
1041 } else {
1042 printk(KERN_WARNING
1043 "%s association %p could not find address "
1044 NIPQUAD_FMT "\n",
1045 __FUNCTION__,
1046 asoc,
1047 NIPQUAD(from_addr.v4.sin_addr.s_addr));
1049 return SCTP_DISPOSITION_DISCARD;
1052 /* Validate the 64-bit random nonce. */
1053 if (hbinfo->hb_nonce != link->hb_nonce)
1054 return SCTP_DISPOSITION_DISCARD;
1056 max_interval = link->hbinterval + link->rto;
1058 /* Check if the timestamp looks valid. */
1059 if (time_after(hbinfo->sent_at, jiffies) ||
1060 time_after(jiffies, hbinfo->sent_at + max_interval)) {
1061 SCTP_DEBUG_PRINTK("%s: HEARTBEAT ACK with invalid timestamp"
1062 "received for transport: %p\n",
1063 __FUNCTION__, link);
1064 return SCTP_DISPOSITION_DISCARD;
1067 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of
1068 * the HEARTBEAT should clear the error counter of the
1069 * destination transport address to which the HEARTBEAT was
1070 * sent and mark the destination transport address as active if
1071 * it is not so marked.
1072 */
1073 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSPORT_ON, SCTP_TRANSPORT(link));
1075 return SCTP_DISPOSITION_CONSUME;
1078 /* Helper function to send out an abort for the restart
1079 * condition.
1080 */
1081 static int sctp_sf_send_restart_abort(union sctp_addr *ssa,
1082 struct sctp_chunk *init,
1083 sctp_cmd_seq_t *commands)
1085 int len;
1086 struct sctp_packet *pkt;
1087 union sctp_addr_param *addrparm;
1088 struct sctp_errhdr *errhdr;
1089 struct sctp_endpoint *ep;
1090 char buffer[sizeof(struct sctp_errhdr)+sizeof(union sctp_addr_param)];
1091 struct sctp_af *af = sctp_get_af_specific(ssa->v4.sin_family);
1093 /* Build the error on the stack. We are way to malloc crazy
1094 * throughout the code today.
1095 */
1096 errhdr = (struct sctp_errhdr *)buffer;
1097 addrparm = (union sctp_addr_param *)errhdr->variable;
1099 /* Copy into a parm format. */
1100 len = af->to_addr_param(ssa, addrparm);
1101 len += sizeof(sctp_errhdr_t);
1103 errhdr->cause = SCTP_ERROR_RESTART;
1104 errhdr->length = htons(len);
1106 /* Assign to the control socket. */
1107 ep = sctp_sk((sctp_get_ctl_sock()))->ep;
1109 /* Association is NULL since this may be a restart attack and we
1110 * want to send back the attacker's vtag.
1111 */
1112 pkt = sctp_abort_pkt_new(ep, NULL, init, errhdr, len);
1114 if (!pkt)
1115 goto out;
1116 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT, SCTP_PACKET(pkt));
1118 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
1120 /* Discard the rest of the inbound packet. */
1121 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
1123 out:
1124 /* Even if there is no memory, treat as a failure so
1125 * the packet will get dropped.
1126 */
1127 return 0;
1130 /* A restart is occurring, check to make sure no new addresses
1131 * are being added as we may be under a takeover attack.
1132 */
1133 static int sctp_sf_check_restart_addrs(const struct sctp_association *new_asoc,
1134 const struct sctp_association *asoc,
1135 struct sctp_chunk *init,
1136 sctp_cmd_seq_t *commands)
1138 struct sctp_transport *new_addr, *addr;
1139 struct list_head *pos, *pos2;
1140 int found;
1142 /* Implementor's Guide - Sectin 5.2.2
1143 * ...
1144 * Before responding the endpoint MUST check to see if the
1145 * unexpected INIT adds new addresses to the association. If new
1146 * addresses are added to the association, the endpoint MUST respond
1147 * with an ABORT..
1148 */
1150 /* Search through all current addresses and make sure
1151 * we aren't adding any new ones.
1152 */
1153 new_addr = NULL;
1154 found = 0;
1156 list_for_each(pos, &new_asoc->peer.transport_addr_list) {
1157 new_addr = list_entry(pos, struct sctp_transport, transports);
1158 found = 0;
1159 list_for_each(pos2, &asoc->peer.transport_addr_list) {
1160 addr = list_entry(pos2, struct sctp_transport,
1161 transports);
1162 if (sctp_cmp_addr_exact(&new_addr->ipaddr,
1163 &addr->ipaddr)) {
1164 found = 1;
1165 break;
1168 if (!found)
1169 break;
1172 /* If a new address was added, ABORT the sender. */
1173 if (!found && new_addr) {
1174 sctp_sf_send_restart_abort(&new_addr->ipaddr, init, commands);
1177 /* Return success if all addresses were found. */
1178 return found;
1181 /* Populate the verification/tie tags based on overlapping INIT
1182 * scenario.
1184 * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state.
1185 */
1186 static void sctp_tietags_populate(struct sctp_association *new_asoc,
1187 const struct sctp_association *asoc)
1189 switch (asoc->state) {
1191 /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */
1193 case SCTP_STATE_COOKIE_WAIT:
1194 new_asoc->c.my_vtag = asoc->c.my_vtag;
1195 new_asoc->c.my_ttag = asoc->c.my_vtag;
1196 new_asoc->c.peer_ttag = 0;
1197 break;
1199 case SCTP_STATE_COOKIE_ECHOED:
1200 new_asoc->c.my_vtag = asoc->c.my_vtag;
1201 new_asoc->c.my_ttag = asoc->c.my_vtag;
1202 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1203 break;
1205 /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED,
1206 * COOKIE-WAIT and SHUTDOWN-ACK-SENT
1207 */
1208 default:
1209 new_asoc->c.my_ttag = asoc->c.my_vtag;
1210 new_asoc->c.peer_ttag = asoc->c.peer_vtag;
1211 break;
1212 };
1214 /* Other parameters for the endpoint SHOULD be copied from the
1215 * existing parameters of the association (e.g. number of
1216 * outbound streams) into the INIT ACK and cookie.
1217 */
1218 new_asoc->rwnd = asoc->rwnd;
1219 new_asoc->c.sinit_num_ostreams = asoc->c.sinit_num_ostreams;
1220 new_asoc->c.sinit_max_instreams = asoc->c.sinit_max_instreams;
1221 new_asoc->c.initial_tsn = asoc->c.initial_tsn;
1224 /*
1225 * Compare vtag/tietag values to determine unexpected COOKIE-ECHO
1226 * handling action.
1228 * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists.
1230 * Returns value representing action to be taken. These action values
1231 * correspond to Action/Description values in RFC 2960, Table 2.
1232 */
1233 static char sctp_tietags_compare(struct sctp_association *new_asoc,
1234 const struct sctp_association *asoc)
1236 /* In this case, the peer may have restarted. */
1237 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1238 (asoc->c.peer_vtag != new_asoc->c.peer_vtag) &&
1239 (asoc->c.my_vtag == new_asoc->c.my_ttag) &&
1240 (asoc->c.peer_vtag == new_asoc->c.peer_ttag))
1241 return 'A';
1243 /* Collision case B. */
1244 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1245 ((asoc->c.peer_vtag != new_asoc->c.peer_vtag) ||
1246 (0 == asoc->c.peer_vtag))) {
1247 return 'B';
1250 /* Collision case D. */
1251 if ((asoc->c.my_vtag == new_asoc->c.my_vtag) &&
1252 (asoc->c.peer_vtag == new_asoc->c.peer_vtag))
1253 return 'D';
1255 /* Collision case C. */
1256 if ((asoc->c.my_vtag != new_asoc->c.my_vtag) &&
1257 (asoc->c.peer_vtag == new_asoc->c.peer_vtag) &&
1258 (0 == new_asoc->c.my_ttag) &&
1259 (0 == new_asoc->c.peer_ttag))
1260 return 'C';
1262 /* No match to any of the special cases; discard this packet. */
1263 return 'E';
1266 /* Common helper routine for both duplicate and simulataneous INIT
1267 * chunk handling.
1268 */
1269 static sctp_disposition_t sctp_sf_do_unexpected_init(
1270 const struct sctp_endpoint *ep,
1271 const struct sctp_association *asoc,
1272 const sctp_subtype_t type,
1273 void *arg, sctp_cmd_seq_t *commands)
1275 sctp_disposition_t retval;
1276 struct sctp_chunk *chunk = arg;
1277 struct sctp_chunk *repl;
1278 struct sctp_association *new_asoc;
1279 struct sctp_chunk *err_chunk;
1280 struct sctp_packet *packet;
1281 sctp_unrecognized_param_t *unk_param;
1282 int len;
1284 /* 6.10 Bundling
1285 * An endpoint MUST NOT bundle INIT, INIT ACK or
1286 * SHUTDOWN COMPLETE with any other chunks.
1288 * IG Section 2.11.2
1289 * Furthermore, we require that the receiver of an INIT chunk MUST
1290 * enforce these rules by silently discarding an arriving packet
1291 * with an INIT chunk that is bundled with other chunks.
1292 */
1293 if (!chunk->singleton)
1294 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1296 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
1297 * Tag.
1298 */
1299 if (chunk->sctp_hdr->vtag != 0)
1300 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
1302 /* Make sure that the INIT chunk has a valid length.
1303 * In this case, we generate a protocol violation since we have
1304 * an association established.
1305 */
1306 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_init_chunk_t)))
1307 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1308 commands);
1309 /* Grab the INIT header. */
1310 chunk->subh.init_hdr = (sctp_inithdr_t *) chunk->skb->data;
1312 /* Tag the variable length parameters. */
1313 chunk->param_hdr.v = skb_pull(chunk->skb, sizeof(sctp_inithdr_t));
1315 /* Verify the INIT chunk before processing it. */
1316 err_chunk = NULL;
1317 if (!sctp_verify_init(asoc, chunk->chunk_hdr->type,
1318 (sctp_init_chunk_t *)chunk->chunk_hdr, chunk,
1319 &err_chunk)) {
1320 /* This chunk contains fatal error. It is to be discarded.
1321 * Send an ABORT, with causes if there is any.
1322 */
1323 if (err_chunk) {
1324 packet = sctp_abort_pkt_new(ep, asoc, arg,
1325 (__u8 *)(err_chunk->chunk_hdr) +
1326 sizeof(sctp_chunkhdr_t),
1327 ntohs(err_chunk->chunk_hdr->length) -
1328 sizeof(sctp_chunkhdr_t));
1330 if (packet) {
1331 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
1332 SCTP_PACKET(packet));
1333 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
1334 retval = SCTP_DISPOSITION_CONSUME;
1335 } else {
1336 retval = SCTP_DISPOSITION_NOMEM;
1338 goto cleanup;
1339 } else {
1340 return sctp_sf_tabort_8_4_8(ep, asoc, type, arg,
1341 commands);
1345 /*
1346 * Other parameters for the endpoint SHOULD be copied from the
1347 * existing parameters of the association (e.g. number of
1348 * outbound streams) into the INIT ACK and cookie.
1349 * FIXME: We are copying parameters from the endpoint not the
1350 * association.
1351 */
1352 new_asoc = sctp_make_temp_asoc(ep, chunk, GFP_ATOMIC);
1353 if (!new_asoc)
1354 goto nomem;
1356 /* In the outbound INIT ACK the endpoint MUST copy its current
1357 * Verification Tag and Peers Verification tag into a reserved
1358 * place (local tie-tag and per tie-tag) within the state cookie.
1359 */
1360 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
1361 sctp_source(chunk),
1362 (sctp_init_chunk_t *)chunk->chunk_hdr,
1363 GFP_ATOMIC)) {
1364 retval = SCTP_DISPOSITION_NOMEM;
1365 goto nomem_init;
1368 /* Make sure no new addresses are being added during the
1369 * restart. Do not do this check for COOKIE-WAIT state,
1370 * since there are no peer addresses to check against.
1371 * Upon return an ABORT will have been sent if needed.
1372 */
1373 if (!sctp_state(asoc, COOKIE_WAIT)) {
1374 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk,
1375 commands)) {
1376 retval = SCTP_DISPOSITION_CONSUME;
1377 goto cleanup_asoc;
1381 sctp_tietags_populate(new_asoc, asoc);
1383 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
1385 /* If there are errors need to be reported for unknown parameters,
1386 * make sure to reserve enough room in the INIT ACK for them.
1387 */
1388 len = 0;
1389 if (err_chunk) {
1390 len = ntohs(err_chunk->chunk_hdr->length) -
1391 sizeof(sctp_chunkhdr_t);
1394 if (sctp_assoc_set_bind_addr_from_ep(new_asoc, GFP_ATOMIC) < 0)
1395 goto nomem;
1397 repl = sctp_make_init_ack(new_asoc, chunk, GFP_ATOMIC, len);
1398 if (!repl)
1399 goto nomem;
1401 /* If there are errors need to be reported for unknown parameters,
1402 * include them in the outgoing INIT ACK as "Unrecognized parameter"
1403 * parameter.
1404 */
1405 if (err_chunk) {
1406 /* Get the "Unrecognized parameter" parameter(s) out of the
1407 * ERROR chunk generated by sctp_verify_init(). Since the
1408 * error cause code for "unknown parameter" and the
1409 * "Unrecognized parameter" type is the same, we can
1410 * construct the parameters in INIT ACK by copying the
1411 * ERROR causes over.
1412 */
1413 unk_param = (sctp_unrecognized_param_t *)
1414 ((__u8 *)(err_chunk->chunk_hdr) +
1415 sizeof(sctp_chunkhdr_t));
1416 /* Replace the cause code with the "Unrecognized parameter"
1417 * parameter type.
1418 */
1419 sctp_addto_chunk(repl, len, unk_param);
1422 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
1423 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1425 /*
1426 * Note: After sending out INIT ACK with the State Cookie parameter,
1427 * "Z" MUST NOT allocate any resources for this new association.
1428 * Otherwise, "Z" will be vulnerable to resource attacks.
1429 */
1430 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
1431 retval = SCTP_DISPOSITION_CONSUME;
1433 cleanup:
1434 if (err_chunk)
1435 sctp_chunk_free(err_chunk);
1436 return retval;
1437 nomem:
1438 retval = SCTP_DISPOSITION_NOMEM;
1439 goto cleanup;
1440 nomem_init:
1441 cleanup_asoc:
1442 sctp_association_free(new_asoc);
1443 goto cleanup;
1446 /*
1447 * Handle simultanous INIT.
1448 * This means we started an INIT and then we got an INIT request from
1449 * our peer.
1451 * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B)
1452 * This usually indicates an initialization collision, i.e., each
1453 * endpoint is attempting, at about the same time, to establish an
1454 * association with the other endpoint.
1456 * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an
1457 * endpoint MUST respond with an INIT ACK using the same parameters it
1458 * sent in its original INIT chunk (including its Verification Tag,
1459 * unchanged). These original parameters are combined with those from the
1460 * newly received INIT chunk. The endpoint shall also generate a State
1461 * Cookie with the INIT ACK. The endpoint uses the parameters sent in its
1462 * INIT to calculate the State Cookie.
1464 * After that, the endpoint MUST NOT change its state, the T1-init
1465 * timer shall be left running and the corresponding TCB MUST NOT be
1466 * destroyed. The normal procedures for handling State Cookies when
1467 * a TCB exists will resolve the duplicate INITs to a single association.
1469 * For an endpoint that is in the COOKIE-ECHOED state it MUST populate
1470 * its Tie-Tags with the Tag information of itself and its peer (see
1471 * section 5.2.2 for a description of the Tie-Tags).
1473 * Verification Tag: Not explicit, but an INIT can not have a valid
1474 * verification tag, so we skip the check.
1476 * Inputs
1477 * (endpoint, asoc, chunk)
1479 * Outputs
1480 * (asoc, reply_msg, msg_up, timers, counters)
1482 * The return value is the disposition of the chunk.
1483 */
1484 sctp_disposition_t sctp_sf_do_5_2_1_siminit(const struct sctp_endpoint *ep,
1485 const struct sctp_association *asoc,
1486 const sctp_subtype_t type,
1487 void *arg,
1488 sctp_cmd_seq_t *commands)
1490 /* Call helper to do the real work for both simulataneous and
1491 * duplicate INIT chunk handling.
1492 */
1493 return sctp_sf_do_unexpected_init(ep, asoc, type, arg, commands);
1496 /*
1497 * Handle duplicated INIT messages. These are usually delayed
1498 * restransmissions.
1500 * Section: 5.2.2 Unexpected INIT in States Other than CLOSED,
1501 * COOKIE-ECHOED and COOKIE-WAIT
1503 * Unless otherwise stated, upon reception of an unexpected INIT for
1504 * this association, the endpoint shall generate an INIT ACK with a
1505 * State Cookie. In the outbound INIT ACK the endpoint MUST copy its
1506 * current Verification Tag and peer's Verification Tag into a reserved
1507 * place within the state cookie. We shall refer to these locations as
1508 * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet
1509 * containing this INIT ACK MUST carry a Verification Tag value equal to
1510 * the Initiation Tag found in the unexpected INIT. And the INIT ACK
1511 * MUST contain a new Initiation Tag (randomly generated see Section
1512 * 5.3.1). Other parameters for the endpoint SHOULD be copied from the
1513 * existing parameters of the association (e.g. number of outbound
1514 * streams) into the INIT ACK and cookie.
1516 * After sending out the INIT ACK, the endpoint shall take no further
1517 * actions, i.e., the existing association, including its current state,
1518 * and the corresponding TCB MUST NOT be changed.
1520 * Note: Only when a TCB exists and the association is not in a COOKIE-
1521 * WAIT state are the Tie-Tags populated. For a normal association INIT
1522 * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be
1523 * set to 0 (indicating that no previous TCB existed). The INIT ACK and
1524 * State Cookie are populated as specified in section 5.2.1.
1526 * Verification Tag: Not specified, but an INIT has no way of knowing
1527 * what the verification tag could be, so we ignore it.
1529 * Inputs
1530 * (endpoint, asoc, chunk)
1532 * Outputs
1533 * (asoc, reply_msg, msg_up, timers, counters)
1535 * The return value is the disposition of the chunk.
1536 */
1537 sctp_disposition_t sctp_sf_do_5_2_2_dupinit(const struct sctp_endpoint *ep,
1538 const struct sctp_association *asoc,
1539 const sctp_subtype_t type,
1540 void *arg,
1541 sctp_cmd_seq_t *commands)
1543 /* Call helper to do the real work for both simulataneous and
1544 * duplicate INIT chunk handling.
1545 */
1546 return sctp_sf_do_unexpected_init(ep, asoc, type, arg, commands);
1551 /* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A')
1553 * Section 5.2.4
1554 * A) In this case, the peer may have restarted.
1555 */
1556 static sctp_disposition_t sctp_sf_do_dupcook_a(const struct sctp_endpoint *ep,
1557 const struct sctp_association *asoc,
1558 struct sctp_chunk *chunk,
1559 sctp_cmd_seq_t *commands,
1560 struct sctp_association *new_asoc)
1562 sctp_init_chunk_t *peer_init;
1563 struct sctp_ulpevent *ev;
1564 struct sctp_chunk *repl;
1565 struct sctp_chunk *err;
1566 sctp_disposition_t disposition;
1568 /* new_asoc is a brand-new association, so these are not yet
1569 * side effects--it is safe to run them here.
1570 */
1571 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1573 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
1574 sctp_source(chunk), peer_init,
1575 GFP_ATOMIC))
1576 goto nomem;
1578 /* Make sure no new addresses are being added during the
1579 * restart. Though this is a pretty complicated attack
1580 * since you'd have to get inside the cookie.
1581 */
1582 if (!sctp_sf_check_restart_addrs(new_asoc, asoc, chunk, commands)) {
1583 return SCTP_DISPOSITION_CONSUME;
1586 /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes
1587 * the peer has restarted (Action A), it MUST NOT setup a new
1588 * association but instead resend the SHUTDOWN ACK and send an ERROR
1589 * chunk with a "Cookie Received while Shutting Down" error cause to
1590 * its peer.
1591 */
1592 if (sctp_state(asoc, SHUTDOWN_ACK_SENT)) {
1593 disposition = sctp_sf_do_9_2_reshutack(ep, asoc,
1594 SCTP_ST_CHUNK(chunk->chunk_hdr->type),
1595 chunk, commands);
1596 if (SCTP_DISPOSITION_NOMEM == disposition)
1597 goto nomem;
1599 err = sctp_make_op_error(asoc, chunk,
1600 SCTP_ERROR_COOKIE_IN_SHUTDOWN,
1601 NULL, 0);
1602 if (err)
1603 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
1604 SCTP_CHUNK(err));
1606 return SCTP_DISPOSITION_CONSUME;
1609 /* For now, fail any unsent/unacked data. Consider the optional
1610 * choice of resending of this data.
1611 */
1612 sctp_add_cmd_sf(commands, SCTP_CMD_PURGE_OUTQUEUE, SCTP_NULL());
1614 /* Update the content of current association. */
1615 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1617 repl = sctp_make_cookie_ack(new_asoc, chunk);
1618 if (!repl)
1619 goto nomem;
1621 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1623 /* Report association restart to upper layer. */
1624 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_RESTART, 0,
1625 new_asoc->c.sinit_num_ostreams,
1626 new_asoc->c.sinit_max_instreams,
1627 GFP_ATOMIC);
1628 if (!ev)
1629 goto nomem_ev;
1631 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
1632 return SCTP_DISPOSITION_CONSUME;
1634 nomem_ev:
1635 sctp_chunk_free(repl);
1636 nomem:
1637 return SCTP_DISPOSITION_NOMEM;
1640 /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B')
1642 * Section 5.2.4
1643 * B) In this case, both sides may be attempting to start an association
1644 * at about the same time but the peer endpoint started its INIT
1645 * after responding to the local endpoint's INIT
1646 */
1647 /* This case represents an initialization collision. */
1648 static sctp_disposition_t sctp_sf_do_dupcook_b(const struct sctp_endpoint *ep,
1649 const struct sctp_association *asoc,
1650 struct sctp_chunk *chunk,
1651 sctp_cmd_seq_t *commands,
1652 struct sctp_association *new_asoc)
1654 sctp_init_chunk_t *peer_init;
1655 struct sctp_ulpevent *ev;
1656 struct sctp_chunk *repl;
1658 /* new_asoc is a brand-new association, so these are not yet
1659 * side effects--it is safe to run them here.
1660 */
1661 peer_init = &chunk->subh.cookie_hdr->c.peer_init[0];
1662 if (!sctp_process_init(new_asoc, chunk->chunk_hdr->type,
1663 sctp_source(chunk), peer_init,
1664 GFP_ATOMIC))
1665 goto nomem;
1667 /* Update the content of current association. */
1668 sctp_add_cmd_sf(commands, SCTP_CMD_UPDATE_ASSOC, SCTP_ASOC(new_asoc));
1669 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1670 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1671 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
1672 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START, SCTP_NULL());
1674 repl = sctp_make_cookie_ack(new_asoc, chunk);
1675 if (!repl)
1676 goto nomem;
1678 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1679 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
1681 /* RFC 2960 5.1 Normal Establishment of an Association
1683 * D) IMPLEMENTATION NOTE: An implementation may choose to
1684 * send the Communication Up notification to the SCTP user
1685 * upon reception of a valid COOKIE ECHO chunk.
1686 */
1687 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_COMM_UP, 0,
1688 new_asoc->c.sinit_num_ostreams,
1689 new_asoc->c.sinit_max_instreams,
1690 GFP_ATOMIC);
1691 if (!ev)
1692 goto nomem_ev;
1694 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
1696 /* Sockets API Draft Section 5.3.1.6
1697 * When a peer sends a Adaption Layer Indication parameter , SCTP
1698 * delivers this notification to inform the application that of the
1699 * peers requested adaption layer.
1700 */
1701 if (asoc->peer.adaption_ind) {
1702 ev = sctp_ulpevent_make_adaption_indication(asoc, GFP_ATOMIC);
1703 if (!ev)
1704 goto nomem_ev;
1706 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1707 SCTP_ULPEVENT(ev));
1710 return SCTP_DISPOSITION_CONSUME;
1712 nomem_ev:
1713 sctp_chunk_free(repl);
1714 nomem:
1715 return SCTP_DISPOSITION_NOMEM;
1718 /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C')
1720 * Section 5.2.4
1721 * C) In this case, the local endpoint's cookie has arrived late.
1722 * Before it arrived, the local endpoint sent an INIT and received an
1723 * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag
1724 * but a new tag of its own.
1725 */
1726 /* This case represents an initialization collision. */
1727 static sctp_disposition_t sctp_sf_do_dupcook_c(const struct sctp_endpoint *ep,
1728 const struct sctp_association *asoc,
1729 struct sctp_chunk *chunk,
1730 sctp_cmd_seq_t *commands,
1731 struct sctp_association *new_asoc)
1733 /* The cookie should be silently discarded.
1734 * The endpoint SHOULD NOT change states and should leave
1735 * any timers running.
1736 */
1737 return SCTP_DISPOSITION_DISCARD;
1740 /* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D')
1742 * Section 5.2.4
1744 * D) When both local and remote tags match the endpoint should always
1745 * enter the ESTABLISHED state, if it has not already done so.
1746 */
1747 /* This case represents an initialization collision. */
1748 static sctp_disposition_t sctp_sf_do_dupcook_d(const struct sctp_endpoint *ep,
1749 const struct sctp_association *asoc,
1750 struct sctp_chunk *chunk,
1751 sctp_cmd_seq_t *commands,
1752 struct sctp_association *new_asoc)
1754 struct sctp_ulpevent *ev = NULL;
1755 struct sctp_chunk *repl;
1757 /* Clarification from Implementor's Guide:
1758 * D) When both local and remote tags match the endpoint should
1759 * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state.
1760 * It should stop any cookie timer that may be running and send
1761 * a COOKIE ACK.
1762 */
1764 /* Don't accidentally move back into established state. */
1765 if (asoc->state < SCTP_STATE_ESTABLISHED) {
1766 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1767 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
1768 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
1769 SCTP_STATE(SCTP_STATE_ESTABLISHED));
1770 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
1771 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_START,
1772 SCTP_NULL());
1774 /* RFC 2960 5.1 Normal Establishment of an Association
1776 * D) IMPLEMENTATION NOTE: An implementation may choose
1777 * to send the Communication Up notification to the
1778 * SCTP user upon reception of a valid COOKIE
1779 * ECHO chunk.
1780 */
1781 ev = sctp_ulpevent_make_assoc_change(new_asoc, 0,
1782 SCTP_COMM_UP, 0,
1783 new_asoc->c.sinit_num_ostreams,
1784 new_asoc->c.sinit_max_instreams,
1785 GFP_ATOMIC);
1786 if (!ev)
1787 goto nomem;
1788 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1789 SCTP_ULPEVENT(ev));
1791 /* Sockets API Draft Section 5.3.1.6
1792 * When a peer sends a Adaption Layer Indication parameter,
1793 * SCTP delivers this notification to inform the application
1794 * that of the peers requested adaption layer.
1795 */
1796 if (new_asoc->peer.adaption_ind) {
1797 ev = sctp_ulpevent_make_adaption_indication(new_asoc,
1798 GFP_ATOMIC);
1799 if (!ev)
1800 goto nomem;
1802 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
1803 SCTP_ULPEVENT(ev));
1806 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
1808 repl = sctp_make_cookie_ack(new_asoc, chunk);
1809 if (!repl)
1810 goto nomem;
1812 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
1813 sctp_add_cmd_sf(commands, SCTP_CMD_TRANSMIT, SCTP_NULL());
1815 return SCTP_DISPOSITION_CONSUME;
1817 nomem:
1818 if (ev)
1819 sctp_ulpevent_free(ev);
1820 return SCTP_DISPOSITION_NOMEM;
1823 /*
1824 * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying
1825 * chunk was retransmitted and then delayed in the network.
1827 * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists
1829 * Verification Tag: None. Do cookie validation.
1831 * Inputs
1832 * (endpoint, asoc, chunk)
1834 * Outputs
1835 * (asoc, reply_msg, msg_up, timers, counters)
1837 * The return value is the disposition of the chunk.
1838 */
1839 sctp_disposition_t sctp_sf_do_5_2_4_dupcook(const struct sctp_endpoint *ep,
1840 const struct sctp_association *asoc,
1841 const sctp_subtype_t type,
1842 void *arg,
1843 sctp_cmd_seq_t *commands)
1845 sctp_disposition_t retval;
1846 struct sctp_chunk *chunk = arg;
1847 struct sctp_association *new_asoc;
1848 int error = 0;
1849 char action;
1850 struct sctp_chunk *err_chk_p;
1852 /* Make sure that the chunk has a valid length from the protocol
1853 * perspective. In this case check to make sure we have at least
1854 * enough for the chunk header. Cookie length verification is
1855 * done later.
1856 */
1857 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
1858 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
1859 commands);
1861 /* "Decode" the chunk. We have no optional parameters so we
1862 * are in good shape.
1863 */
1864 chunk->subh.cookie_hdr = (struct sctp_signed_cookie *)chunk->skb->data;
1865 if (!pskb_pull(chunk->skb, ntohs(chunk->chunk_hdr->length) -
1866 sizeof(sctp_chunkhdr_t)))
1867 goto nomem;
1869 /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
1870 * of a duplicate COOKIE ECHO match the Verification Tags of the
1871 * current association, consider the State Cookie valid even if
1872 * the lifespan is exceeded.
1873 */
1874 new_asoc = sctp_unpack_cookie(ep, asoc, chunk, GFP_ATOMIC, &error,
1875 &err_chk_p);
1877 /* FIXME:
1878 * If the re-build failed, what is the proper error path
1879 * from here?
1881 * [We should abort the association. --piggy]
1882 */
1883 if (!new_asoc) {
1884 /* FIXME: Several errors are possible. A bad cookie should
1885 * be silently discarded, but think about logging it too.
1886 */
1887 switch (error) {
1888 case -SCTP_IERROR_NOMEM:
1889 goto nomem;
1891 case -SCTP_IERROR_STALE_COOKIE:
1892 sctp_send_stale_cookie_err(ep, asoc, chunk, commands,
1893 err_chk_p);
1894 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1895 case -SCTP_IERROR_BAD_SIG:
1896 default:
1897 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1898 };
1901 /* Compare the tie_tag in cookie with the verification tag of
1902 * current association.
1903 */
1904 action = sctp_tietags_compare(new_asoc, asoc);
1906 switch (action) {
1907 case 'A': /* Association restart. */
1908 retval = sctp_sf_do_dupcook_a(ep, asoc, chunk, commands,
1909 new_asoc);
1910 break;
1912 case 'B': /* Collision case B. */
1913 retval = sctp_sf_do_dupcook_b(ep, asoc, chunk, commands,
1914 new_asoc);
1915 break;
1917 case 'C': /* Collision case C. */
1918 retval = sctp_sf_do_dupcook_c(ep, asoc, chunk, commands,
1919 new_asoc);
1920 break;
1922 case 'D': /* Collision case D. */
1923 retval = sctp_sf_do_dupcook_d(ep, asoc, chunk, commands,
1924 new_asoc);
1925 break;
1927 default: /* Discard packet for all others. */
1928 retval = sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1929 break;
1930 };
1932 /* Delete the tempory new association. */
1933 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC, SCTP_ASOC(new_asoc));
1934 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
1936 return retval;
1938 nomem:
1939 return SCTP_DISPOSITION_NOMEM;
1942 /*
1943 * Process an ABORT. (SHUTDOWN-PENDING state)
1945 * See sctp_sf_do_9_1_abort().
1946 */
1947 sctp_disposition_t sctp_sf_shutdown_pending_abort(
1948 const struct sctp_endpoint *ep,
1949 const struct sctp_association *asoc,
1950 const sctp_subtype_t type,
1951 void *arg,
1952 sctp_cmd_seq_t *commands)
1954 struct sctp_chunk *chunk = arg;
1956 if (!sctp_vtag_verify_either(chunk, asoc))
1957 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1959 /* Make sure that the ABORT chunk has a valid length.
1960 * Since this is an ABORT chunk, we have to discard it
1961 * because of the following text:
1962 * RFC 2960, Section 3.3.7
1963 * If an endpoint receives an ABORT with a format error or for an
1964 * association that doesn't exist, it MUST silently discard it.
1965 * Becasue the length is "invalid", we can't really discard just
1966 * as we do not know its true length. So, to be safe, discard the
1967 * packet.
1968 */
1969 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
1970 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1972 /* Stop the T5-shutdown guard timer. */
1973 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
1974 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
1976 return sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
1979 /*
1980 * Process an ABORT. (SHUTDOWN-SENT state)
1982 * See sctp_sf_do_9_1_abort().
1983 */
1984 sctp_disposition_t sctp_sf_shutdown_sent_abort(const struct sctp_endpoint *ep,
1985 const struct sctp_association *asoc,
1986 const sctp_subtype_t type,
1987 void *arg,
1988 sctp_cmd_seq_t *commands)
1990 struct sctp_chunk *chunk = arg;
1992 if (!sctp_vtag_verify_either(chunk, asoc))
1993 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
1995 /* Make sure that the ABORT chunk has a valid length.
1996 * Since this is an ABORT chunk, we have to discard it
1997 * because of the following text:
1998 * RFC 2960, Section 3.3.7
1999 * If an endpoint receives an ABORT with a format error or for an
2000 * association that doesn't exist, it MUST silently discard it.
2001 * Becasue the length is "invalid", we can't really discard just
2002 * as we do not know its true length. So, to be safe, discard the
2003 * packet.
2004 */
2005 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2006 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2008 /* Stop the T2-shutdown timer. */
2009 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2010 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2012 /* Stop the T5-shutdown guard timer. */
2013 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2014 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
2016 return sctp_sf_do_9_1_abort(ep, asoc, type, arg, commands);
2019 /*
2020 * Process an ABORT. (SHUTDOWN-ACK-SENT state)
2022 * See sctp_sf_do_9_1_abort().
2023 */
2024 sctp_disposition_t sctp_sf_shutdown_ack_sent_abort(
2025 const struct sctp_endpoint *ep,
2026 const struct sctp_association *asoc,
2027 const sctp_subtype_t type,
2028 void *arg,
2029 sctp_cmd_seq_t *commands)
2031 /* The same T2 timer, so we should be able to use
2032 * common function with the SHUTDOWN-SENT state.
2033 */
2034 return sctp_sf_shutdown_sent_abort(ep, asoc, type, arg, commands);
2037 /*
2038 * Handle an Error received in COOKIE_ECHOED state.
2040 * Only handle the error type of stale COOKIE Error, the other errors will
2041 * be ignored.
2043 * Inputs
2044 * (endpoint, asoc, chunk)
2046 * Outputs
2047 * (asoc, reply_msg, msg_up, timers, counters)
2049 * The return value is the disposition of the chunk.
2050 */
2051 sctp_disposition_t sctp_sf_cookie_echoed_err(const struct sctp_endpoint *ep,
2052 const struct sctp_association *asoc,
2053 const sctp_subtype_t type,
2054 void *arg,
2055 sctp_cmd_seq_t *commands)
2057 struct sctp_chunk *chunk = arg;
2058 sctp_errhdr_t *err;
2060 if (!sctp_vtag_verify(chunk, asoc))
2061 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2063 /* Make sure that the ERROR chunk has a valid length.
2064 * The parameter walking depends on this as well.
2065 */
2066 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
2067 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2068 commands);
2070 /* Process the error here */
2071 /* FUTURE FIXME: When PR-SCTP related and other optional
2072 * parms are emitted, this will have to change to handle multiple
2073 * errors.
2074 */
2075 sctp_walk_errors(err, chunk->chunk_hdr) {
2076 if (SCTP_ERROR_STALE_COOKIE == err->cause)
2077 return sctp_sf_do_5_2_6_stale(ep, asoc, type,
2078 arg, commands);
2081 /* It is possible to have malformed error causes, and that
2082 * will cause us to end the walk early. However, since
2083 * we are discarding the packet, there should be no adverse
2084 * affects.
2085 */
2086 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2089 /*
2090 * Handle a Stale COOKIE Error
2092 * Section: 5.2.6 Handle Stale COOKIE Error
2093 * If the association is in the COOKIE-ECHOED state, the endpoint may elect
2094 * one of the following three alternatives.
2095 * ...
2096 * 3) Send a new INIT chunk to the endpoint, adding a Cookie
2097 * Preservative parameter requesting an extension to the lifetime of
2098 * the State Cookie. When calculating the time extension, an
2099 * implementation SHOULD use the RTT information measured based on the
2100 * previous COOKIE ECHO / ERROR exchange, and should add no more
2101 * than 1 second beyond the measured RTT, due to long State Cookie
2102 * lifetimes making the endpoint more subject to a replay attack.
2104 * Verification Tag: Not explicit, but safe to ignore.
2106 * Inputs
2107 * (endpoint, asoc, chunk)
2109 * Outputs
2110 * (asoc, reply_msg, msg_up, timers, counters)
2112 * The return value is the disposition of the chunk.
2113 */
2114 static sctp_disposition_t sctp_sf_do_5_2_6_stale(const struct sctp_endpoint *ep,
2115 const struct sctp_association *asoc,
2116 const sctp_subtype_t type,
2117 void *arg,
2118 sctp_cmd_seq_t *commands)
2120 struct sctp_chunk *chunk = arg;
2121 time_t stale;
2122 sctp_cookie_preserve_param_t bht;
2123 sctp_errhdr_t *err;
2124 struct sctp_chunk *reply;
2125 struct sctp_bind_addr *bp;
2126 int attempts = asoc->init_err_counter + 1;
2128 if (attempts > asoc->max_init_attempts) {
2129 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
2130 SCTP_ERROR(ETIMEDOUT));
2131 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
2132 SCTP_U32(SCTP_ERROR_STALE_COOKIE));
2133 return SCTP_DISPOSITION_DELETE_TCB;
2136 err = (sctp_errhdr_t *)(chunk->skb->data);
2138 /* When calculating the time extension, an implementation
2139 * SHOULD use the RTT information measured based on the
2140 * previous COOKIE ECHO / ERROR exchange, and should add no
2141 * more than 1 second beyond the measured RTT, due to long
2142 * State Cookie lifetimes making the endpoint more subject to
2143 * a replay attack.
2144 * Measure of Staleness's unit is usec. (1/1000000 sec)
2145 * Suggested Cookie Life-span Increment's unit is msec.
2146 * (1/1000 sec)
2147 * In general, if you use the suggested cookie life, the value
2148 * found in the field of measure of staleness should be doubled
2149 * to give ample time to retransmit the new cookie and thus
2150 * yield a higher probability of success on the reattempt.
2151 */
2152 stale = ntohl(*(suseconds_t *)((u8 *)err + sizeof(sctp_errhdr_t)));
2153 stale = (stale * 2) / 1000;
2155 bht.param_hdr.type = SCTP_PARAM_COOKIE_PRESERVATIVE;
2156 bht.param_hdr.length = htons(sizeof(bht));
2157 bht.lifespan_increment = htonl(stale);
2159 /* Build that new INIT chunk. */
2160 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
2161 reply = sctp_make_init(asoc, bp, GFP_ATOMIC, sizeof(bht));
2162 if (!reply)
2163 goto nomem;
2165 sctp_addto_chunk(reply, sizeof(bht), &bht);
2167 /* Clear peer's init_tag cached in assoc as we are sending a new INIT */
2168 sctp_add_cmd_sf(commands, SCTP_CMD_CLEAR_INIT_TAG, SCTP_NULL());
2170 /* Stop pending T3-rtx and heartbeat timers */
2171 sctp_add_cmd_sf(commands, SCTP_CMD_T3_RTX_TIMERS_STOP, SCTP_NULL());
2172 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
2174 /* Delete non-primary peer ip addresses since we are transitioning
2175 * back to the COOKIE-WAIT state
2176 */
2177 sctp_add_cmd_sf(commands, SCTP_CMD_DEL_NON_PRIMARY, SCTP_NULL());
2179 /* If we've sent any data bundled with COOKIE-ECHO we will need to
2180 * resend
2181 */
2182 sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN,
2183 SCTP_TRANSPORT(asoc->peer.primary_path));
2185 /* Cast away the const modifier, as we want to just
2186 * rerun it through as a sideffect.
2187 */
2188 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_COUNTER_INC, SCTP_NULL());
2190 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2191 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
2192 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2193 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
2194 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
2195 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
2197 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2199 return SCTP_DISPOSITION_CONSUME;
2201 nomem:
2202 return SCTP_DISPOSITION_NOMEM;
2205 /*
2206 * Process an ABORT.
2208 * Section: 9.1
2209 * After checking the Verification Tag, the receiving endpoint shall
2210 * remove the association from its record, and shall report the
2211 * termination to its upper layer.
2213 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
2214 * B) Rules for packet carrying ABORT:
2216 * - The endpoint shall always fill in the Verification Tag field of the
2217 * outbound packet with the destination endpoint's tag value if it
2218 * is known.
2220 * - If the ABORT is sent in response to an OOTB packet, the endpoint
2221 * MUST follow the procedure described in Section 8.4.
2223 * - The receiver MUST accept the packet if the Verification Tag
2224 * matches either its own tag, OR the tag of its peer. Otherwise, the
2225 * receiver MUST silently discard the packet and take no further
2226 * action.
2228 * Inputs
2229 * (endpoint, asoc, chunk)
2231 * Outputs
2232 * (asoc, reply_msg, msg_up, timers, counters)
2234 * The return value is the disposition of the chunk.
2235 */
2236 sctp_disposition_t sctp_sf_do_9_1_abort(const struct sctp_endpoint *ep,
2237 const struct sctp_association *asoc,
2238 const sctp_subtype_t type,
2239 void *arg,
2240 sctp_cmd_seq_t *commands)
2242 struct sctp_chunk *chunk = arg;
2243 unsigned len;
2244 __u16 error = SCTP_ERROR_NO_ERROR;
2246 if (!sctp_vtag_verify_either(chunk, asoc))
2247 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2249 /* Make sure that the ABORT chunk has a valid length.
2250 * Since this is an ABORT chunk, we have to discard it
2251 * because of the following text:
2252 * RFC 2960, Section 3.3.7
2253 * If an endpoint receives an ABORT with a format error or for an
2254 * association that doesn't exist, it MUST silently discard it.
2255 * Becasue the length is "invalid", we can't really discard just
2256 * as we do not know its true length. So, to be safe, discard the
2257 * packet.
2258 */
2259 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2260 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2262 /* See if we have an error cause code in the chunk. */
2263 len = ntohs(chunk->chunk_hdr->length);
2264 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
2265 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2267 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(ECONNRESET));
2268 /* ASSOC_FAILED will DELETE_TCB. */
2269 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED, SCTP_U32(error));
2270 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
2271 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
2273 return SCTP_DISPOSITION_ABORT;
2276 /*
2277 * Process an ABORT. (COOKIE-WAIT state)
2279 * See sctp_sf_do_9_1_abort() above.
2280 */
2281 sctp_disposition_t sctp_sf_cookie_wait_abort(const struct sctp_endpoint *ep,
2282 const struct sctp_association *asoc,
2283 const sctp_subtype_t type,
2284 void *arg,
2285 sctp_cmd_seq_t *commands)
2287 struct sctp_chunk *chunk = arg;
2288 unsigned len;
2289 __u16 error = SCTP_ERROR_NO_ERROR;
2291 if (!sctp_vtag_verify_either(chunk, asoc))
2292 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2294 /* Make sure that the ABORT chunk has a valid length.
2295 * Since this is an ABORT chunk, we have to discard it
2296 * because of the following text:
2297 * RFC 2960, Section 3.3.7
2298 * If an endpoint receives an ABORT with a format error or for an
2299 * association that doesn't exist, it MUST silently discard it.
2300 * Becasue the length is "invalid", we can't really discard just
2301 * as we do not know its true length. So, to be safe, discard the
2302 * packet.
2303 */
2304 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_abort_chunk_t)))
2305 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2307 /* See if we have an error cause code in the chunk. */
2308 len = ntohs(chunk->chunk_hdr->length);
2309 if (len >= sizeof(struct sctp_chunkhdr) + sizeof(struct sctp_errhdr))
2310 error = ((sctp_errhdr_t *)chunk->skb->data)->cause;
2312 return sctp_stop_t1_and_abort(commands, error, ECONNREFUSED, asoc,
2313 chunk->transport);
2316 /*
2317 * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state)
2318 */
2319 sctp_disposition_t sctp_sf_cookie_wait_icmp_abort(const struct sctp_endpoint *ep,
2320 const struct sctp_association *asoc,
2321 const sctp_subtype_t type,
2322 void *arg,
2323 sctp_cmd_seq_t *commands)
2325 return sctp_stop_t1_and_abort(commands, SCTP_ERROR_NO_ERROR,
2326 ENOPROTOOPT, asoc,
2327 (struct sctp_transport *)arg);
2330 /*
2331 * Process an ABORT. (COOKIE-ECHOED state)
2332 */
2333 sctp_disposition_t sctp_sf_cookie_echoed_abort(const struct sctp_endpoint *ep,
2334 const struct sctp_association *asoc,
2335 const sctp_subtype_t type,
2336 void *arg,
2337 sctp_cmd_seq_t *commands)
2339 /* There is a single T1 timer, so we should be able to use
2340 * common function with the COOKIE-WAIT state.
2341 */
2342 return sctp_sf_cookie_wait_abort(ep, asoc, type, arg, commands);
2345 /*
2346 * Stop T1 timer and abort association with "INIT failed".
2348 * This is common code called by several sctp_sf_*_abort() functions above.
2349 */
2350 static sctp_disposition_t sctp_stop_t1_and_abort(sctp_cmd_seq_t *commands,
2351 __u16 error, int sk_err,
2352 const struct sctp_association *asoc,
2353 struct sctp_transport *transport)
2355 SCTP_DEBUG_PRINTK("ABORT received (INIT).\n");
2356 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2357 SCTP_STATE(SCTP_STATE_CLOSED));
2358 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
2359 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
2360 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
2361 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR, SCTP_ERROR(sk_err));
2362 /* CMD_INIT_FAILED will DELETE_TCB. */
2363 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
2364 SCTP_U32(error));
2365 return SCTP_DISPOSITION_ABORT;
2368 /*
2369 * sctp_sf_do_9_2_shut
2371 * Section: 9.2
2372 * Upon the reception of the SHUTDOWN, the peer endpoint shall
2373 * - enter the SHUTDOWN-RECEIVED state,
2375 * - stop accepting new data from its SCTP user
2377 * - verify, by checking the Cumulative TSN Ack field of the chunk,
2378 * that all its outstanding DATA chunks have been received by the
2379 * SHUTDOWN sender.
2381 * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT
2382 * send a SHUTDOWN in response to a ULP request. And should discard
2383 * subsequent SHUTDOWN chunks.
2385 * If there are still outstanding DATA chunks left, the SHUTDOWN
2386 * receiver shall continue to follow normal data transmission
2387 * procedures defined in Section 6 until all outstanding DATA chunks
2388 * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept
2389 * new data from its SCTP user.
2391 * Verification Tag: 8.5 Verification Tag [Normal verification]
2393 * Inputs
2394 * (endpoint, asoc, chunk)
2396 * Outputs
2397 * (asoc, reply_msg, msg_up, timers, counters)
2399 * The return value is the disposition of the chunk.
2400 */
2401 sctp_disposition_t sctp_sf_do_9_2_shutdown(const struct sctp_endpoint *ep,
2402 const struct sctp_association *asoc,
2403 const sctp_subtype_t type,
2404 void *arg,
2405 sctp_cmd_seq_t *commands)
2407 struct sctp_chunk *chunk = arg;
2408 sctp_shutdownhdr_t *sdh;
2409 sctp_disposition_t disposition;
2410 struct sctp_ulpevent *ev;
2412 if (!sctp_vtag_verify(chunk, asoc))
2413 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2415 /* Make sure that the SHUTDOWN chunk has a valid length. */
2416 if (!sctp_chunk_length_valid(chunk,
2417 sizeof(struct sctp_shutdown_chunk_t)))
2418 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2419 commands);
2421 /* Convert the elaborate header. */
2422 sdh = (sctp_shutdownhdr_t *)chunk->skb->data;
2423 skb_pull(chunk->skb, sizeof(sctp_shutdownhdr_t));
2424 chunk->subh.shutdown_hdr = sdh;
2426 /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT
2427 * When a peer sends a SHUTDOWN, SCTP delivers this notification to
2428 * inform the application that it should cease sending data.
2429 */
2430 ev = sctp_ulpevent_make_shutdown_event(asoc, 0, GFP_ATOMIC);
2431 if (!ev) {
2432 disposition = SCTP_DISPOSITION_NOMEM;
2433 goto out;
2435 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
2437 /* Upon the reception of the SHUTDOWN, the peer endpoint shall
2438 * - enter the SHUTDOWN-RECEIVED state,
2439 * - stop accepting new data from its SCTP user
2441 * [This is implicit in the new state.]
2442 */
2443 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
2444 SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED));
2445 disposition = SCTP_DISPOSITION_CONSUME;
2447 if (sctp_outq_is_empty(&asoc->outqueue)) {
2448 disposition = sctp_sf_do_9_2_shutdown_ack(ep, asoc, type,
2449 arg, commands);
2452 if (SCTP_DISPOSITION_NOMEM == disposition)
2453 goto out;
2455 /* - verify, by checking the Cumulative TSN Ack field of the
2456 * chunk, that all its outstanding DATA chunks have been
2457 * received by the SHUTDOWN sender.
2458 */
2459 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_CTSN,
2460 SCTP_U32(chunk->subh.shutdown_hdr->cum_tsn_ack));
2462 out:
2463 return disposition;
2466 /* RFC 2960 9.2
2467 * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk
2468 * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination
2469 * transport addresses (either in the IP addresses or in the INIT chunk)
2470 * that belong to this association, it should discard the INIT chunk and
2471 * retransmit the SHUTDOWN ACK chunk.
2472 */
2473 sctp_disposition_t sctp_sf_do_9_2_reshutack(const struct sctp_endpoint *ep,
2474 const struct sctp_association *asoc,
2475 const sctp_subtype_t type,
2476 void *arg,
2477 sctp_cmd_seq_t *commands)
2479 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
2480 struct sctp_chunk *reply;
2482 /* Since we are not going to really process this INIT, there
2483 * is no point in verifying chunk boundries. Just generate
2484 * the SHUTDOWN ACK.
2485 */
2486 reply = sctp_make_shutdown_ack(asoc, chunk);
2487 if (NULL == reply)
2488 goto nomem;
2490 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
2491 * the T2-SHUTDOWN timer.
2492 */
2493 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
2495 /* and restart the T2-shutdown timer. */
2496 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2497 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2499 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
2501 return SCTP_DISPOSITION_CONSUME;
2502 nomem:
2503 return SCTP_DISPOSITION_NOMEM;
2506 /*
2507 * sctp_sf_do_ecn_cwr
2509 * Section: Appendix A: Explicit Congestion Notification
2511 * CWR:
2513 * RFC 2481 details a specific bit for a sender to send in the header of
2514 * its next outbound TCP segment to indicate to its peer that it has
2515 * reduced its congestion window. This is termed the CWR bit. For
2516 * SCTP the same indication is made by including the CWR chunk.
2517 * This chunk contains one data element, i.e. the TSN number that
2518 * was sent in the ECNE chunk. This element represents the lowest
2519 * TSN number in the datagram that was originally marked with the
2520 * CE bit.
2522 * Verification Tag: 8.5 Verification Tag [Normal verification]
2523 * Inputs
2524 * (endpoint, asoc, chunk)
2526 * Outputs
2527 * (asoc, reply_msg, msg_up, timers, counters)
2529 * The return value is the disposition of the chunk.
2530 */
2531 sctp_disposition_t sctp_sf_do_ecn_cwr(const struct sctp_endpoint *ep,
2532 const struct sctp_association *asoc,
2533 const sctp_subtype_t type,
2534 void *arg,
2535 sctp_cmd_seq_t *commands)
2537 sctp_cwrhdr_t *cwr;
2538 struct sctp_chunk *chunk = arg;
2540 if (!sctp_vtag_verify(chunk, asoc))
2541 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2543 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2544 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2545 commands);
2547 cwr = (sctp_cwrhdr_t *) chunk->skb->data;
2548 skb_pull(chunk->skb, sizeof(sctp_cwrhdr_t));
2550 cwr->lowest_tsn = ntohl(cwr->lowest_tsn);
2552 /* Does this CWR ack the last sent congestion notification? */
2553 if (TSN_lte(asoc->last_ecne_tsn, cwr->lowest_tsn)) {
2554 /* Stop sending ECNE. */
2555 sctp_add_cmd_sf(commands,
2556 SCTP_CMD_ECN_CWR,
2557 SCTP_U32(cwr->lowest_tsn));
2559 return SCTP_DISPOSITION_CONSUME;
2562 /*
2563 * sctp_sf_do_ecne
2565 * Section: Appendix A: Explicit Congestion Notification
2567 * ECN-Echo
2569 * RFC 2481 details a specific bit for a receiver to send back in its
2570 * TCP acknowledgements to notify the sender of the Congestion
2571 * Experienced (CE) bit having arrived from the network. For SCTP this
2572 * same indication is made by including the ECNE chunk. This chunk
2573 * contains one data element, i.e. the lowest TSN associated with the IP
2574 * datagram marked with the CE bit.....
2576 * Verification Tag: 8.5 Verification Tag [Normal verification]
2577 * Inputs
2578 * (endpoint, asoc, chunk)
2580 * Outputs
2581 * (asoc, reply_msg, msg_up, timers, counters)
2583 * The return value is the disposition of the chunk.
2584 */
2585 sctp_disposition_t sctp_sf_do_ecne(const struct sctp_endpoint *ep,
2586 const struct sctp_association *asoc,
2587 const sctp_subtype_t type,
2588 void *arg,
2589 sctp_cmd_seq_t *commands)
2591 sctp_ecnehdr_t *ecne;
2592 struct sctp_chunk *chunk = arg;
2594 if (!sctp_vtag_verify(chunk, asoc))
2595 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2597 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_ecne_chunk_t)))
2598 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2599 commands);
2601 ecne = (sctp_ecnehdr_t *) chunk->skb->data;
2602 skb_pull(chunk->skb, sizeof(sctp_ecnehdr_t));
2604 /* If this is a newer ECNE than the last CWR packet we sent out */
2605 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_ECNE,
2606 SCTP_U32(ntohl(ecne->lowest_tsn)));
2608 return SCTP_DISPOSITION_CONSUME;
2611 /*
2612 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
2614 * The SCTP endpoint MUST always acknowledge the reception of each valid
2615 * DATA chunk.
2617 * The guidelines on delayed acknowledgement algorithm specified in
2618 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
2619 * acknowledgement SHOULD be generated for at least every second packet
2620 * (not every second DATA chunk) received, and SHOULD be generated within
2621 * 200 ms of the arrival of any unacknowledged DATA chunk. In some
2622 * situations it may be beneficial for an SCTP transmitter to be more
2623 * conservative than the algorithms detailed in this document allow.
2624 * However, an SCTP transmitter MUST NOT be more aggressive than the
2625 * following algorithms allow.
2627 * A SCTP receiver MUST NOT generate more than one SACK for every
2628 * incoming packet, other than to update the offered window as the
2629 * receiving application consumes new data.
2631 * Verification Tag: 8.5 Verification Tag [Normal verification]
2633 * Inputs
2634 * (endpoint, asoc, chunk)
2636 * Outputs
2637 * (asoc, reply_msg, msg_up, timers, counters)
2639 * The return value is the disposition of the chunk.
2640 */
2641 sctp_disposition_t sctp_sf_eat_data_6_2(const struct sctp_endpoint *ep,
2642 const struct sctp_association *asoc,
2643 const sctp_subtype_t type,
2644 void *arg,
2645 sctp_cmd_seq_t *commands)
2647 struct sctp_chunk *chunk = arg;
2648 int error;
2650 if (!sctp_vtag_verify(chunk, asoc)) {
2651 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
2652 SCTP_NULL());
2653 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2656 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
2657 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2658 commands);
2660 error = sctp_eat_data(asoc, chunk, commands );
2661 switch (error) {
2662 case SCTP_IERROR_NO_ERROR:
2663 break;
2664 case SCTP_IERROR_HIGH_TSN:
2665 case SCTP_IERROR_BAD_STREAM:
2666 goto discard_noforce;
2667 case SCTP_IERROR_DUP_TSN:
2668 case SCTP_IERROR_IGNORE_TSN:
2669 goto discard_force;
2670 case SCTP_IERROR_NO_DATA:
2671 goto consume;
2672 default:
2673 BUG();
2676 if (asoc->autoclose) {
2677 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2678 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
2681 /* If this is the last chunk in a packet, we need to count it
2682 * toward sack generation. Note that we need to SACK every
2683 * OTHER packet containing data chunks, EVEN IF WE DISCARD
2684 * THEM. We elect to NOT generate SACK's if the chunk fails
2685 * the verification tag test.
2687 * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2689 * The SCTP endpoint MUST always acknowledge the reception of
2690 * each valid DATA chunk.
2692 * The guidelines on delayed acknowledgement algorithm
2693 * specified in Section 4.2 of [RFC2581] SHOULD be followed.
2694 * Specifically, an acknowledgement SHOULD be generated for at
2695 * least every second packet (not every second DATA chunk)
2696 * received, and SHOULD be generated within 200 ms of the
2697 * arrival of any unacknowledged DATA chunk. In some
2698 * situations it may be beneficial for an SCTP transmitter to
2699 * be more conservative than the algorithms detailed in this
2700 * document allow. However, an SCTP transmitter MUST NOT be
2701 * more aggressive than the following algorithms allow.
2702 */
2703 if (chunk->end_of_packet)
2704 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
2706 return SCTP_DISPOSITION_CONSUME;
2708 discard_force:
2709 /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2711 * When a packet arrives with duplicate DATA chunk(s) and with
2712 * no new DATA chunk(s), the endpoint MUST immediately send a
2713 * SACK with no delay. If a packet arrives with duplicate
2714 * DATA chunk(s) bundled with new DATA chunks, the endpoint
2715 * MAY immediately send a SACK. Normally receipt of duplicate
2716 * DATA chunks will occur when the original SACK chunk was lost
2717 * and the peer's RTO has expired. The duplicate TSN number(s)
2718 * SHOULD be reported in the SACK as duplicate.
2719 */
2720 /* In our case, we split the MAY SACK advice up whether or not
2721 * the last chunk is a duplicate.'
2722 */
2723 if (chunk->end_of_packet)
2724 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
2725 return SCTP_DISPOSITION_DISCARD;
2727 discard_noforce:
2728 if (chunk->end_of_packet)
2729 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
2731 return SCTP_DISPOSITION_DISCARD;
2732 consume:
2733 return SCTP_DISPOSITION_CONSUME;
2737 /*
2738 * sctp_sf_eat_data_fast_4_4
2740 * Section: 4 (4)
2741 * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received
2742 * DATA chunks without delay.
2744 * Verification Tag: 8.5 Verification Tag [Normal verification]
2745 * Inputs
2746 * (endpoint, asoc, chunk)
2748 * Outputs
2749 * (asoc, reply_msg, msg_up, timers, counters)
2751 * The return value is the disposition of the chunk.
2752 */
2753 sctp_disposition_t sctp_sf_eat_data_fast_4_4(const struct sctp_endpoint *ep,
2754 const struct sctp_association *asoc,
2755 const sctp_subtype_t type,
2756 void *arg,
2757 sctp_cmd_seq_t *commands)
2759 struct sctp_chunk *chunk = arg;
2760 int error;
2762 if (!sctp_vtag_verify(chunk, asoc)) {
2763 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
2764 SCTP_NULL());
2765 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2768 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_data_chunk_t)))
2769 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2770 commands);
2772 error = sctp_eat_data(asoc, chunk, commands );
2773 switch (error) {
2774 case SCTP_IERROR_NO_ERROR:
2775 case SCTP_IERROR_HIGH_TSN:
2776 case SCTP_IERROR_DUP_TSN:
2777 case SCTP_IERROR_IGNORE_TSN:
2778 case SCTP_IERROR_BAD_STREAM:
2779 break;
2780 case SCTP_IERROR_NO_DATA:
2781 goto consume;
2782 default:
2783 BUG();
2786 /* Go a head and force a SACK, since we are shutting down. */
2788 /* Implementor's Guide.
2790 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
2791 * respond to each received packet containing one or more DATA chunk(s)
2792 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
2793 */
2794 if (chunk->end_of_packet) {
2795 /* We must delay the chunk creation since the cumulative
2796 * TSN has not been updated yet.
2797 */
2798 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
2799 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
2800 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
2801 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
2804 consume:
2805 return SCTP_DISPOSITION_CONSUME;
2808 /*
2809 * Section: 6.2 Processing a Received SACK
2810 * D) Any time a SACK arrives, the endpoint performs the following:
2812 * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point,
2813 * then drop the SACK. Since Cumulative TSN Ack is monotonically
2814 * increasing, a SACK whose Cumulative TSN Ack is less than the
2815 * Cumulative TSN Ack Point indicates an out-of-order SACK.
2817 * ii) Set rwnd equal to the newly received a_rwnd minus the number
2818 * of bytes still outstanding after processing the Cumulative TSN Ack
2819 * and the Gap Ack Blocks.
2821 * iii) If the SACK is missing a TSN that was previously
2822 * acknowledged via a Gap Ack Block (e.g., the data receiver
2823 * reneged on the data), then mark the corresponding DATA chunk
2824 * as available for retransmit: Mark it as missing for fast
2825 * retransmit as described in Section 7.2.4 and if no retransmit
2826 * timer is running for the destination address to which the DATA
2827 * chunk was originally transmitted, then T3-rtx is started for
2828 * that destination address.
2830 * Verification Tag: 8.5 Verification Tag [Normal verification]
2832 * Inputs
2833 * (endpoint, asoc, chunk)
2835 * Outputs
2836 * (asoc, reply_msg, msg_up, timers, counters)
2838 * The return value is the disposition of the chunk.
2839 */
2840 sctp_disposition_t sctp_sf_eat_sack_6_2(const struct sctp_endpoint *ep,
2841 const struct sctp_association *asoc,
2842 const sctp_subtype_t type,
2843 void *arg,
2844 sctp_cmd_seq_t *commands)
2846 struct sctp_chunk *chunk = arg;
2847 sctp_sackhdr_t *sackh;
2848 __u32 ctsn;
2850 if (!sctp_vtag_verify(chunk, asoc))
2851 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2853 /* Make sure that the SACK chunk has a valid length. */
2854 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_sack_chunk_t)))
2855 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2856 commands);
2858 /* Pull the SACK chunk from the data buffer */
2859 sackh = sctp_sm_pull_sack(chunk);
2860 /* Was this a bogus SACK? */
2861 if (!sackh)
2862 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2863 chunk->subh.sack_hdr = sackh;
2864 ctsn = ntohl(sackh->cum_tsn_ack);
2866 /* i) If Cumulative TSN Ack is less than the Cumulative TSN
2867 * Ack Point, then drop the SACK. Since Cumulative TSN
2868 * Ack is monotonically increasing, a SACK whose
2869 * Cumulative TSN Ack is less than the Cumulative TSN Ack
2870 * Point indicates an out-of-order SACK.
2871 */
2872 if (TSN_lt(ctsn, asoc->ctsn_ack_point)) {
2873 SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn);
2874 SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc->ctsn_ack_point);
2875 return SCTP_DISPOSITION_DISCARD;
2878 /* Return this SACK for further processing. */
2879 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_SACK, SCTP_SACKH(sackh));
2881 /* Note: We do the rest of the work on the PROCESS_SACK
2882 * sideeffect.
2883 */
2884 return SCTP_DISPOSITION_CONSUME;
2887 /*
2888 * Generate an ABORT in response to a packet.
2890 * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41
2892 * 8) The receiver should respond to the sender of the OOTB packet with
2893 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
2894 * MUST fill in the Verification Tag field of the outbound packet
2895 * with the value found in the Verification Tag field of the OOTB
2896 * packet and set the T-bit in the Chunk Flags to indicate that the
2897 * Verification Tag is reflected. After sending this ABORT, the
2898 * receiver of the OOTB packet shall discard the OOTB packet and take
2899 * no further action.
2901 * Verification Tag:
2903 * The return value is the disposition of the chunk.
2904 */
2905 sctp_disposition_t sctp_sf_tabort_8_4_8(const struct sctp_endpoint *ep,
2906 const struct sctp_association *asoc,
2907 const sctp_subtype_t type,
2908 void *arg,
2909 sctp_cmd_seq_t *commands)
2911 struct sctp_packet *packet = NULL;
2912 struct sctp_chunk *chunk = arg;
2913 struct sctp_chunk *abort;
2915 packet = sctp_ootb_pkt_new(asoc, chunk);
2917 if (packet) {
2918 /* Make an ABORT. The T bit will be set if the asoc
2919 * is NULL.
2920 */
2921 abort = sctp_make_abort(asoc, chunk, 0);
2922 if (!abort) {
2923 sctp_ootb_pkt_free(packet);
2924 return SCTP_DISPOSITION_NOMEM;
2927 /* Reflect vtag if T-Bit is set */
2928 if (sctp_test_T_bit(abort))
2929 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
2931 /* Set the skb to the belonging sock for accounting. */
2932 abort->skb->sk = ep->base.sk;
2934 sctp_packet_append_chunk(packet, abort);
2936 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
2937 SCTP_PACKET(packet));
2939 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
2941 return SCTP_DISPOSITION_CONSUME;
2944 return SCTP_DISPOSITION_NOMEM;
2947 /*
2948 * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR
2949 * event as ULP notification for each cause included in the chunk.
2951 * API 5.3.1.3 - SCTP_REMOTE_ERROR
2953 * The return value is the disposition of the chunk.
2954 */
2955 sctp_disposition_t sctp_sf_operr_notify(const struct sctp_endpoint *ep,
2956 const struct sctp_association *asoc,
2957 const sctp_subtype_t type,
2958 void *arg,
2959 sctp_cmd_seq_t *commands)
2961 struct sctp_chunk *chunk = arg;
2962 struct sctp_ulpevent *ev;
2964 if (!sctp_vtag_verify(chunk, asoc))
2965 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
2967 /* Make sure that the ERROR chunk has a valid length. */
2968 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_operr_chunk_t)))
2969 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
2970 commands);
2972 while (chunk->chunk_end > chunk->skb->data) {
2973 ev = sctp_ulpevent_make_remote_error(asoc, chunk, 0,
2974 GFP_ATOMIC);
2975 if (!ev)
2976 goto nomem;
2978 if (!sctp_add_cmd(commands, SCTP_CMD_EVENT_ULP,
2979 SCTP_ULPEVENT(ev))) {
2980 sctp_ulpevent_free(ev);
2981 goto nomem;
2984 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_OPERR,
2985 SCTP_CHUNK(chunk));
2987 return SCTP_DISPOSITION_CONSUME;
2989 nomem:
2990 return SCTP_DISPOSITION_NOMEM;
2993 /*
2994 * Process an inbound SHUTDOWN ACK.
2996 * From Section 9.2:
2997 * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
2998 * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its
2999 * peer, and remove all record of the association.
3001 * The return value is the disposition.
3002 */
3003 sctp_disposition_t sctp_sf_do_9_2_final(const struct sctp_endpoint *ep,
3004 const struct sctp_association *asoc,
3005 const sctp_subtype_t type,
3006 void *arg,
3007 sctp_cmd_seq_t *commands)
3009 struct sctp_chunk *chunk = arg;
3010 struct sctp_chunk *reply;
3011 struct sctp_ulpevent *ev;
3013 if (!sctp_vtag_verify(chunk, asoc))
3014 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3016 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3017 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3018 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3019 commands);
3021 /* 10.2 H) SHUTDOWN COMPLETE notification
3023 * When SCTP completes the shutdown procedures (section 9.2) this
3024 * notification is passed to the upper layer.
3025 */
3026 ev = sctp_ulpevent_make_assoc_change(asoc, 0, SCTP_SHUTDOWN_COMP,
3027 0, 0, 0, GFP_ATOMIC);
3028 if (!ev)
3029 goto nomem;
3031 sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP, SCTP_ULPEVENT(ev));
3033 /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3034 * stop the T2-shutdown timer,
3035 */
3036 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3037 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3039 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3040 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
3042 /* ...send a SHUTDOWN COMPLETE chunk to its peer, */
3043 reply = sctp_make_shutdown_complete(asoc, chunk);
3044 if (!reply)
3045 goto nomem;
3047 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3048 SCTP_STATE(SCTP_STATE_CLOSED));
3049 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
3050 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3051 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
3053 /* ...and remove all record of the association. */
3054 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
3055 return SCTP_DISPOSITION_DELETE_TCB;
3057 nomem:
3058 return SCTP_DISPOSITION_NOMEM;
3061 /*
3062 * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41.
3064 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3065 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3066 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3067 * packet must fill in the Verification Tag field of the outbound
3068 * packet with the Verification Tag received in the SHUTDOWN ACK and
3069 * set the T-bit in the Chunk Flags to indicate that the Verification
3070 * Tag is reflected.
3072 * 8) The receiver should respond to the sender of the OOTB packet with
3073 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3074 * MUST fill in the Verification Tag field of the outbound packet
3075 * with the value found in the Verification Tag field of the OOTB
3076 * packet and set the T-bit in the Chunk Flags to indicate that the
3077 * Verification Tag is reflected. After sending this ABORT, the
3078 * receiver of the OOTB packet shall discard the OOTB packet and take
3079 * no further action.
3080 */
3081 sctp_disposition_t sctp_sf_ootb(const struct sctp_endpoint *ep,
3082 const struct sctp_association *asoc,
3083 const sctp_subtype_t type,
3084 void *arg,
3085 sctp_cmd_seq_t *commands)
3087 struct sctp_chunk *chunk = arg;
3088 struct sk_buff *skb = chunk->skb;
3089 sctp_chunkhdr_t *ch;
3090 __u8 *ch_end;
3091 int ootb_shut_ack = 0;
3093 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES);
3095 ch = (sctp_chunkhdr_t *) chunk->chunk_hdr;
3096 do {
3097 /* Break out if chunk length is less then minimal. */
3098 if (ntohs(ch->length) < sizeof(sctp_chunkhdr_t))
3099 break;
3101 ch_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
3102 if (ch_end > skb->tail)
3103 break;
3105 if (SCTP_CID_SHUTDOWN_ACK == ch->type)
3106 ootb_shut_ack = 1;
3108 /* RFC 2960, Section 3.3.7
3109 * Moreover, under any circumstances, an endpoint that
3110 * receives an ABORT MUST NOT respond to that ABORT by
3111 * sending an ABORT of its own.
3112 */
3113 if (SCTP_CID_ABORT == ch->type)
3114 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3116 ch = (sctp_chunkhdr_t *) ch_end;
3117 } while (ch_end < skb->tail);
3119 if (ootb_shut_ack)
3120 sctp_sf_shut_8_4_5(ep, asoc, type, arg, commands);
3121 else
3122 sctp_sf_tabort_8_4_8(ep, asoc, type, arg, commands);
3124 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3127 /*
3128 * Handle an "Out of the blue" SHUTDOWN ACK.
3130 * Section: 8.4 5, sctpimpguide 2.41.
3132 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3133 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3134 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3135 * packet must fill in the Verification Tag field of the outbound
3136 * packet with the Verification Tag received in the SHUTDOWN ACK and
3137 * set the T-bit in the Chunk Flags to indicate that the Verification
3138 * Tag is reflected.
3140 * Inputs
3141 * (endpoint, asoc, type, arg, commands)
3143 * Outputs
3144 * (sctp_disposition_t)
3146 * The return value is the disposition of the chunk.
3147 */
3148 static sctp_disposition_t sctp_sf_shut_8_4_5(const struct sctp_endpoint *ep,
3149 const struct sctp_association *asoc,
3150 const sctp_subtype_t type,
3151 void *arg,
3152 sctp_cmd_seq_t *commands)
3154 struct sctp_packet *packet = NULL;
3155 struct sctp_chunk *chunk = arg;
3156 struct sctp_chunk *shut;
3158 packet = sctp_ootb_pkt_new(asoc, chunk);
3160 if (packet) {
3161 /* Make an SHUTDOWN_COMPLETE.
3162 * The T bit will be set if the asoc is NULL.
3163 */
3164 shut = sctp_make_shutdown_complete(asoc, chunk);
3165 if (!shut) {
3166 sctp_ootb_pkt_free(packet);
3167 return SCTP_DISPOSITION_NOMEM;
3170 /* Reflect vtag if T-Bit is set */
3171 if (sctp_test_T_bit(shut))
3172 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
3174 /* Set the skb to the belonging sock for accounting. */
3175 shut->skb->sk = ep->base.sk;
3177 sctp_packet_append_chunk(packet, shut);
3179 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
3180 SCTP_PACKET(packet));
3182 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
3184 /* If the chunk length is invalid, we don't want to process
3185 * the reset of the packet.
3186 */
3187 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_chunkhdr_t)))
3188 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3190 return SCTP_DISPOSITION_CONSUME;
3193 return SCTP_DISPOSITION_NOMEM;
3196 /*
3197 * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state.
3199 * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK
3200 * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the
3201 * procedures in section 8.4 SHOULD be followed, in other words it
3202 * should be treated as an Out Of The Blue packet.
3203 * [This means that we do NOT check the Verification Tag on these
3204 * chunks. --piggy ]
3206 */
3207 sctp_disposition_t sctp_sf_do_8_5_1_E_sa(const struct sctp_endpoint *ep,
3208 const struct sctp_association *asoc,
3209 const sctp_subtype_t type,
3210 void *arg,
3211 sctp_cmd_seq_t *commands)
3213 /* Although we do have an association in this case, it corresponds
3214 * to a restarted association. So the packet is treated as an OOTB
3215 * packet and the state function that handles OOTB SHUTDOWN_ACK is
3216 * called with a NULL association.
3217 */
3218 return sctp_sf_shut_8_4_5(ep, NULL, type, arg, commands);
3221 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */
3222 sctp_disposition_t sctp_sf_do_asconf(const struct sctp_endpoint *ep,
3223 const struct sctp_association *asoc,
3224 const sctp_subtype_t type, void *arg,
3225 sctp_cmd_seq_t *commands)
3227 struct sctp_chunk *chunk = arg;
3228 struct sctp_chunk *asconf_ack = NULL;
3229 sctp_addiphdr_t *hdr;
3230 __u32 serial;
3232 if (!sctp_vtag_verify(chunk, asoc)) {
3233 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3234 SCTP_NULL());
3235 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3238 /* Make sure that the ASCONF ADDIP chunk has a valid length. */
3239 if (!sctp_chunk_length_valid(chunk, sizeof(sctp_addip_chunk_t)))
3240 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3241 commands);
3243 hdr = (sctp_addiphdr_t *)chunk->skb->data;
3244 serial = ntohl(hdr->serial);
3246 /* ADDIP 4.2 C1) Compare the value of the serial number to the value
3247 * the endpoint stored in a new association variable
3248 * 'Peer-Serial-Number'.
3249 */
3250 if (serial == asoc->peer.addip_serial + 1) {
3251 /* ADDIP 4.2 C2) If the value found in the serial number is
3252 * equal to the ('Peer-Serial-Number' + 1), the endpoint MUST
3253 * do V1-V5.
3254 */
3255 asconf_ack = sctp_process_asconf((struct sctp_association *)
3256 asoc, chunk);
3257 if (!asconf_ack)
3258 return SCTP_DISPOSITION_NOMEM;
3259 } else if (serial == asoc->peer.addip_serial) {
3260 /* ADDIP 4.2 C3) If the value found in the serial number is
3261 * equal to the value stored in the 'Peer-Serial-Number'
3262 * IMPLEMENTATION NOTE: As an optimization a receiver may wish
3263 * to save the last ASCONF-ACK for some predetermined period of
3264 * time and instead of re-processing the ASCONF (with the same
3265 * serial number) it may just re-transmit the ASCONF-ACK.
3266 */
3267 if (asoc->addip_last_asconf_ack)
3268 asconf_ack = asoc->addip_last_asconf_ack;
3269 else
3270 return SCTP_DISPOSITION_DISCARD;
3271 } else {
3272 /* ADDIP 4.2 C4) Otherwise, the ASCONF Chunk is discarded since
3273 * it must be either a stale packet or from an attacker.
3274 */
3275 return SCTP_DISPOSITION_DISCARD;
3278 /* ADDIP 4.2 C5) In both cases C2 and C3 the ASCONF-ACK MUST be sent
3279 * back to the source address contained in the IP header of the ASCONF
3280 * being responded to.
3281 */
3282 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(asconf_ack));
3284 return SCTP_DISPOSITION_CONSUME;
3287 /*
3288 * ADDIP Section 4.3 General rules for address manipulation
3289 * When building TLV parameters for the ASCONF Chunk that will add or
3290 * delete IP addresses the D0 to D13 rules should be applied:
3291 */
3292 sctp_disposition_t sctp_sf_do_asconf_ack(const struct sctp_endpoint *ep,
3293 const struct sctp_association *asoc,
3294 const sctp_subtype_t type, void *arg,
3295 sctp_cmd_seq_t *commands)
3297 struct sctp_chunk *asconf_ack = arg;
3298 struct sctp_chunk *last_asconf = asoc->addip_last_asconf;
3299 struct sctp_chunk *abort;
3300 sctp_addiphdr_t *addip_hdr;
3301 __u32 sent_serial, rcvd_serial;
3303 if (!sctp_vtag_verify(asconf_ack, asoc)) {
3304 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3305 SCTP_NULL());
3306 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3309 /* Make sure that the ADDIP chunk has a valid length. */
3310 if (!sctp_chunk_length_valid(asconf_ack, sizeof(sctp_addip_chunk_t)))
3311 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3312 commands);
3314 addip_hdr = (sctp_addiphdr_t *)asconf_ack->skb->data;
3315 rcvd_serial = ntohl(addip_hdr->serial);
3317 if (last_asconf) {
3318 addip_hdr = (sctp_addiphdr_t *)last_asconf->subh.addip_hdr;
3319 sent_serial = ntohl(addip_hdr->serial);
3320 } else {
3321 sent_serial = asoc->addip_serial - 1;
3324 /* D0) If an endpoint receives an ASCONF-ACK that is greater than or
3325 * equal to the next serial number to be used but no ASCONF chunk is
3326 * outstanding the endpoint MUST ABORT the association. Note that a
3327 * sequence number is greater than if it is no more than 2^^31-1
3328 * larger than the current sequence number (using serial arithmetic).
3329 */
3330 if (ADDIP_SERIAL_gte(rcvd_serial, sent_serial + 1) &&
3331 !(asoc->addip_last_asconf)) {
3332 abort = sctp_make_abort(asoc, asconf_ack,
3333 sizeof(sctp_errhdr_t));
3334 if (abort) {
3335 sctp_init_cause(abort, SCTP_ERROR_ASCONF_ACK, NULL, 0);
3336 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3337 SCTP_CHUNK(abort));
3339 /* We are going to ABORT, so we might as well stop
3340 * processing the rest of the chunks in the packet.
3341 */
3342 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3343 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3344 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
3345 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
3346 SCTP_ERROR(ECONNABORTED));
3347 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
3348 SCTP_U32(SCTP_ERROR_ASCONF_ACK));
3349 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
3350 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3351 return SCTP_DISPOSITION_ABORT;
3354 if ((rcvd_serial == sent_serial) && asoc->addip_last_asconf) {
3355 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3356 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
3358 if (!sctp_process_asconf_ack((struct sctp_association *)asoc,
3359 asconf_ack))
3360 return SCTP_DISPOSITION_CONSUME;
3362 abort = sctp_make_abort(asoc, asconf_ack,
3363 sizeof(sctp_errhdr_t));
3364 if (abort) {
3365 sctp_init_cause(abort, SCTP_ERROR_RSRC_LOW, NULL, 0);
3366 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3367 SCTP_CHUNK(abort));
3369 /* We are going to ABORT, so we might as well stop
3370 * processing the rest of the chunks in the packet.
3371 */
3372 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
3373 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
3374 SCTP_ERROR(ECONNABORTED));
3375 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
3376 SCTP_U32(SCTP_ERROR_ASCONF_ACK));
3377 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
3378 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3379 return SCTP_DISPOSITION_ABORT;
3382 return SCTP_DISPOSITION_DISCARD;
3385 /*
3386 * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP
3388 * When a FORWARD TSN chunk arrives, the data receiver MUST first update
3389 * its cumulative TSN point to the value carried in the FORWARD TSN
3390 * chunk, and then MUST further advance its cumulative TSN point locally
3391 * if possible.
3392 * After the above processing, the data receiver MUST stop reporting any
3393 * missing TSNs earlier than or equal to the new cumulative TSN point.
3395 * Verification Tag: 8.5 Verification Tag [Normal verification]
3397 * The return value is the disposition of the chunk.
3398 */
3399 sctp_disposition_t sctp_sf_eat_fwd_tsn(const struct sctp_endpoint *ep,
3400 const struct sctp_association *asoc,
3401 const sctp_subtype_t type,
3402 void *arg,
3403 sctp_cmd_seq_t *commands)
3405 struct sctp_chunk *chunk = arg;
3406 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
3407 __u16 len;
3408 __u32 tsn;
3410 if (!sctp_vtag_verify(chunk, asoc)) {
3411 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3412 SCTP_NULL());
3413 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3416 /* Make sure that the FORWARD_TSN chunk has valid length. */
3417 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
3418 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3419 commands);
3421 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3422 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3423 len = ntohs(chunk->chunk_hdr->length);
3424 len -= sizeof(struct sctp_chunkhdr);
3425 skb_pull(chunk->skb, len);
3427 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
3428 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __FUNCTION__, tsn);
3430 /* The TSN is too high--silently discard the chunk and count on it
3431 * getting retransmitted later.
3432 */
3433 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3434 goto discard_noforce;
3436 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3437 if (len > sizeof(struct sctp_fwdtsn_hdr))
3438 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
3439 SCTP_CHUNK(chunk));
3441 /* Count this as receiving DATA. */
3442 if (asoc->autoclose) {
3443 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3444 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
3447 /* FIXME: For now send a SACK, but DATA processing may
3448 * send another.
3449 */
3450 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_NOFORCE());
3452 return SCTP_DISPOSITION_CONSUME;
3454 discard_noforce:
3455 return SCTP_DISPOSITION_DISCARD;
3458 sctp_disposition_t sctp_sf_eat_fwd_tsn_fast(
3459 const struct sctp_endpoint *ep,
3460 const struct sctp_association *asoc,
3461 const sctp_subtype_t type,
3462 void *arg,
3463 sctp_cmd_seq_t *commands)
3465 struct sctp_chunk *chunk = arg;
3466 struct sctp_fwdtsn_hdr *fwdtsn_hdr;
3467 __u16 len;
3468 __u32 tsn;
3470 if (!sctp_vtag_verify(chunk, asoc)) {
3471 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_BAD_TAG,
3472 SCTP_NULL());
3473 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3476 /* Make sure that the FORWARD_TSN chunk has a valid length. */
3477 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_fwdtsn_chunk)))
3478 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3479 commands);
3481 fwdtsn_hdr = (struct sctp_fwdtsn_hdr *)chunk->skb->data;
3482 chunk->subh.fwdtsn_hdr = fwdtsn_hdr;
3483 len = ntohs(chunk->chunk_hdr->length);
3484 len -= sizeof(struct sctp_chunkhdr);
3485 skb_pull(chunk->skb, len);
3487 tsn = ntohl(fwdtsn_hdr->new_cum_tsn);
3488 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __FUNCTION__, tsn);
3490 /* The TSN is too high--silently discard the chunk and count on it
3491 * getting retransmitted later.
3492 */
3493 if (sctp_tsnmap_check(&asoc->peer.tsn_map, tsn) < 0)
3494 goto gen_shutdown;
3496 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_FWDTSN, SCTP_U32(tsn));
3497 if (len > sizeof(struct sctp_fwdtsn_hdr))
3498 sctp_add_cmd_sf(commands, SCTP_CMD_PROCESS_FWDTSN,
3499 SCTP_CHUNK(chunk));
3501 /* Go a head and force a SACK, since we are shutting down. */
3502 gen_shutdown:
3503 /* Implementor's Guide.
3505 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3506 * respond to each received packet containing one or more DATA chunk(s)
3507 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3508 */
3509 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SHUTDOWN, SCTP_NULL());
3510 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
3511 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
3512 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
3514 return SCTP_DISPOSITION_CONSUME;
3517 /*
3518 * Process an unknown chunk.
3520 * Section: 3.2. Also, 2.1 in the implementor's guide.
3522 * Chunk Types are encoded such that the highest-order two bits specify
3523 * the action that must be taken if the processing endpoint does not
3524 * recognize the Chunk Type.
3526 * 00 - Stop processing this SCTP packet and discard it, do not process
3527 * any further chunks within it.
3529 * 01 - Stop processing this SCTP packet and discard it, do not process
3530 * any further chunks within it, and report the unrecognized
3531 * chunk in an 'Unrecognized Chunk Type'.
3533 * 10 - Skip this chunk and continue processing.
3535 * 11 - Skip this chunk and continue processing, but report in an ERROR
3536 * Chunk using the 'Unrecognized Chunk Type' cause of error.
3538 * The return value is the disposition of the chunk.
3539 */
3540 sctp_disposition_t sctp_sf_unk_chunk(const struct sctp_endpoint *ep,
3541 const struct sctp_association *asoc,
3542 const sctp_subtype_t type,
3543 void *arg,
3544 sctp_cmd_seq_t *commands)
3546 struct sctp_chunk *unk_chunk = arg;
3547 struct sctp_chunk *err_chunk;
3548 sctp_chunkhdr_t *hdr;
3550 SCTP_DEBUG_PRINTK("Processing the unknown chunk id %d.\n", type.chunk);
3552 if (!sctp_vtag_verify(unk_chunk, asoc))
3553 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3555 /* Make sure that the chunk has a valid length.
3556 * Since we don't know the chunk type, we use a general
3557 * chunkhdr structure to make a comparison.
3558 */
3559 if (!sctp_chunk_length_valid(unk_chunk, sizeof(sctp_chunkhdr_t)))
3560 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
3561 commands);
3563 switch (type.chunk & SCTP_CID_ACTION_MASK) {
3564 case SCTP_CID_ACTION_DISCARD:
3565 /* Discard the packet. */
3566 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3567 break;
3568 case SCTP_CID_ACTION_DISCARD_ERR:
3569 /* Discard the packet. */
3570 sctp_sf_pdiscard(ep, asoc, type, arg, commands);
3572 /* Generate an ERROR chunk as response. */
3573 hdr = unk_chunk->chunk_hdr;
3574 err_chunk = sctp_make_op_error(asoc, unk_chunk,
3575 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
3576 WORD_ROUND(ntohs(hdr->length)));
3577 if (err_chunk) {
3578 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3579 SCTP_CHUNK(err_chunk));
3581 return SCTP_DISPOSITION_CONSUME;
3582 break;
3583 case SCTP_CID_ACTION_SKIP:
3584 /* Skip the chunk. */
3585 return SCTP_DISPOSITION_DISCARD;
3586 break;
3587 case SCTP_CID_ACTION_SKIP_ERR:
3588 /* Generate an ERROR chunk as response. */
3589 hdr = unk_chunk->chunk_hdr;
3590 err_chunk = sctp_make_op_error(asoc, unk_chunk,
3591 SCTP_ERROR_UNKNOWN_CHUNK, hdr,
3592 WORD_ROUND(ntohs(hdr->length)));
3593 if (err_chunk) {
3594 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
3595 SCTP_CHUNK(err_chunk));
3597 /* Skip the chunk. */
3598 return SCTP_DISPOSITION_CONSUME;
3599 break;
3600 default:
3601 break;
3604 return SCTP_DISPOSITION_DISCARD;
3607 /*
3608 * Discard the chunk.
3610 * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2
3611 * [Too numerous to mention...]
3612 * Verification Tag: No verification needed.
3613 * Inputs
3614 * (endpoint, asoc, chunk)
3616 * Outputs
3617 * (asoc, reply_msg, msg_up, timers, counters)
3619 * The return value is the disposition of the chunk.
3620 */
3621 sctp_disposition_t sctp_sf_discard_chunk(const struct sctp_endpoint *ep,
3622 const struct sctp_association *asoc,
3623 const sctp_subtype_t type,
3624 void *arg,
3625 sctp_cmd_seq_t *commands)
3627 SCTP_DEBUG_PRINTK("Chunk %d is discarded\n", type.chunk);
3628 return SCTP_DISPOSITION_DISCARD;
3631 /*
3632 * Discard the whole packet.
3634 * Section: 8.4 2)
3636 * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST
3637 * silently discard the OOTB packet and take no further action.
3639 * Verification Tag: No verification necessary
3641 * Inputs
3642 * (endpoint, asoc, chunk)
3644 * Outputs
3645 * (asoc, reply_msg, msg_up, timers, counters)
3647 * The return value is the disposition of the chunk.
3648 */
3649 sctp_disposition_t sctp_sf_pdiscard(const struct sctp_endpoint *ep,
3650 const struct sctp_association *asoc,
3651 const sctp_subtype_t type,
3652 void *arg,
3653 sctp_cmd_seq_t *commands)
3655 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
3657 return SCTP_DISPOSITION_CONSUME;
3661 /*
3662 * The other end is violating protocol.
3664 * Section: Not specified
3665 * Verification Tag: Not specified
3666 * Inputs
3667 * (endpoint, asoc, chunk)
3669 * Outputs
3670 * (asoc, reply_msg, msg_up, timers, counters)
3672 * We simply tag the chunk as a violation. The state machine will log
3673 * the violation and continue.
3674 */
3675 sctp_disposition_t sctp_sf_violation(const struct sctp_endpoint *ep,
3676 const struct sctp_association *asoc,
3677 const sctp_subtype_t type,
3678 void *arg,
3679 sctp_cmd_seq_t *commands)
3681 return SCTP_DISPOSITION_VIOLATION;
3685 /*
3686 * Handle a protocol violation when the chunk length is invalid.
3687 * "Invalid" length is identified as smaller then the minimal length a
3688 * given chunk can be. For example, a SACK chunk has invalid length
3689 * if it's length is set to be smaller then the size of sctp_sack_chunk_t.
3691 * We inform the other end by sending an ABORT with a Protocol Violation
3692 * error code.
3694 * Section: Not specified
3695 * Verification Tag: Nothing to do
3696 * Inputs
3697 * (endpoint, asoc, chunk)
3699 * Outputs
3700 * (reply_msg, msg_up, counters)
3702 * Generate an ABORT chunk and terminate the association.
3703 */
3704 static sctp_disposition_t sctp_sf_violation_chunklen(
3705 const struct sctp_endpoint *ep,
3706 const struct sctp_association *asoc,
3707 const sctp_subtype_t type,
3708 void *arg,
3709 sctp_cmd_seq_t *commands)
3711 struct sctp_chunk *chunk = arg;
3712 struct sctp_chunk *abort = NULL;
3713 char err_str[]="The following chunk had invalid length:";
3715 /* Make the abort chunk. */
3716 abort = sctp_make_abort_violation(asoc, chunk, err_str,
3717 sizeof(err_str));
3718 if (!abort)
3719 goto nomem;
3721 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
3722 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
3724 if (asoc->state <= SCTP_STATE_COOKIE_ECHOED) {
3725 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
3726 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
3727 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
3728 SCTP_ERROR(ECONNREFUSED));
3729 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
3730 SCTP_U32(SCTP_ERROR_PROTO_VIOLATION));
3731 } else {
3732 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
3733 SCTP_ERROR(ECONNABORTED));
3734 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
3735 SCTP_U32(SCTP_ERROR_PROTO_VIOLATION));
3736 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
3739 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET, SCTP_NULL());
3741 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
3743 return SCTP_DISPOSITION_ABORT;
3745 nomem:
3746 return SCTP_DISPOSITION_NOMEM;
3749 /***************************************************************************
3750 * These are the state functions for handling primitive (Section 10) events.
3751 ***************************************************************************/
3752 /*
3753 * sctp_sf_do_prm_asoc
3755 * Section: 10.1 ULP-to-SCTP
3756 * B) Associate
3758 * Format: ASSOCIATE(local SCTP instance name, destination transport addr,
3759 * outbound stream count)
3760 * -> association id [,destination transport addr list] [,outbound stream
3761 * count]
3763 * This primitive allows the upper layer to initiate an association to a
3764 * specific peer endpoint.
3766 * The peer endpoint shall be specified by one of the transport addresses
3767 * which defines the endpoint (see Section 1.4). If the local SCTP
3768 * instance has not been initialized, the ASSOCIATE is considered an
3769 * error.
3770 * [This is not relevant for the kernel implementation since we do all
3771 * initialization at boot time. It we hadn't initialized we wouldn't
3772 * get anywhere near this code.]
3774 * An association id, which is a local handle to the SCTP association,
3775 * will be returned on successful establishment of the association. If
3776 * SCTP is not able to open an SCTP association with the peer endpoint,
3777 * an error is returned.
3778 * [In the kernel implementation, the struct sctp_association needs to
3779 * be created BEFORE causing this primitive to run.]
3781 * Other association parameters may be returned, including the
3782 * complete destination transport addresses of the peer as well as the
3783 * outbound stream count of the local endpoint. One of the transport
3784 * address from the returned destination addresses will be selected by
3785 * the local endpoint as default primary path for sending SCTP packets
3786 * to this peer. The returned "destination transport addr list" can
3787 * be used by the ULP to change the default primary path or to force
3788 * sending a packet to a specific transport address. [All of this
3789 * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING
3790 * function.]
3792 * Mandatory attributes:
3794 * o local SCTP instance name - obtained from the INITIALIZE operation.
3795 * [This is the argument asoc.]
3796 * o destination transport addr - specified as one of the transport
3797 * addresses of the peer endpoint with which the association is to be
3798 * established.
3799 * [This is asoc->peer.active_path.]
3800 * o outbound stream count - the number of outbound streams the ULP
3801 * would like to open towards this peer endpoint.
3802 * [BUG: This is not currently implemented.]
3803 * Optional attributes:
3805 * None.
3807 * The return value is a disposition.
3808 */
3809 sctp_disposition_t sctp_sf_do_prm_asoc(const struct sctp_endpoint *ep,
3810 const struct sctp_association *asoc,
3811 const sctp_subtype_t type,
3812 void *arg,
3813 sctp_cmd_seq_t *commands)
3815 struct sctp_chunk *repl;
3817 /* The comment below says that we enter COOKIE-WAIT AFTER
3818 * sending the INIT, but that doesn't actually work in our
3819 * implementation...
3820 */
3821 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3822 SCTP_STATE(SCTP_STATE_COOKIE_WAIT));
3824 /* RFC 2960 5.1 Normal Establishment of an Association
3826 * A) "A" first sends an INIT chunk to "Z". In the INIT, "A"
3827 * must provide its Verification Tag (Tag_A) in the Initiate
3828 * Tag field. Tag_A SHOULD be a random number in the range of
3829 * 1 to 4294967295 (see 5.3.1 for Tag value selection). ...
3830 */
3832 repl = sctp_make_init(asoc, &asoc->base.bind_addr, GFP_ATOMIC, 0);
3833 if (!repl)
3834 goto nomem;
3836 /* Cast away the const modifier, as we want to just
3837 * rerun it through as a sideffect.
3838 */
3839 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_ASOC,
3840 SCTP_ASOC((struct sctp_association *) asoc));
3842 /* Choose transport for INIT. */
3843 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
3844 SCTP_CHUNK(repl));
3846 /* After sending the INIT, "A" starts the T1-init timer and
3847 * enters the COOKIE-WAIT state.
3848 */
3849 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
3850 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
3851 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
3852 return SCTP_DISPOSITION_CONSUME;
3854 nomem:
3855 return SCTP_DISPOSITION_NOMEM;
3858 /*
3859 * Process the SEND primitive.
3861 * Section: 10.1 ULP-to-SCTP
3862 * E) Send
3864 * Format: SEND(association id, buffer address, byte count [,context]
3865 * [,stream id] [,life time] [,destination transport address]
3866 * [,unorder flag] [,no-bundle flag] [,payload protocol-id] )
3867 * -> result
3869 * This is the main method to send user data via SCTP.
3871 * Mandatory attributes:
3873 * o association id - local handle to the SCTP association
3875 * o buffer address - the location where the user message to be
3876 * transmitted is stored;
3878 * o byte count - The size of the user data in number of bytes;
3880 * Optional attributes:
3882 * o context - an optional 32 bit integer that will be carried in the
3883 * sending failure notification to the ULP if the transportation of
3884 * this User Message fails.
3886 * o stream id - to indicate which stream to send the data on. If not
3887 * specified, stream 0 will be used.
3889 * o life time - specifies the life time of the user data. The user data
3890 * will not be sent by SCTP after the life time expires. This
3891 * parameter can be used to avoid efforts to transmit stale
3892 * user messages. SCTP notifies the ULP if the data cannot be
3893 * initiated to transport (i.e. sent to the destination via SCTP's
3894 * send primitive) within the life time variable. However, the
3895 * user data will be transmitted if SCTP has attempted to transmit a
3896 * chunk before the life time expired.
3898 * o destination transport address - specified as one of the destination
3899 * transport addresses of the peer endpoint to which this packet
3900 * should be sent. Whenever possible, SCTP should use this destination
3901 * transport address for sending the packets, instead of the current
3902 * primary path.
3904 * o unorder flag - this flag, if present, indicates that the user
3905 * would like the data delivered in an unordered fashion to the peer
3906 * (i.e., the U flag is set to 1 on all DATA chunks carrying this
3907 * message).
3909 * o no-bundle flag - instructs SCTP not to bundle this user data with
3910 * other outbound DATA chunks. SCTP MAY still bundle even when
3911 * this flag is present, when faced with network congestion.
3913 * o payload protocol-id - A 32 bit unsigned integer that is to be
3914 * passed to the peer indicating the type of payload protocol data
3915 * being transmitted. This value is passed as opaque data by SCTP.
3917 * The return value is the disposition.
3918 */
3919 sctp_disposition_t sctp_sf_do_prm_send(const struct sctp_endpoint *ep,
3920 const struct sctp_association *asoc,
3921 const sctp_subtype_t type,
3922 void *arg,
3923 sctp_cmd_seq_t *commands)
3925 struct sctp_chunk *chunk = arg;
3927 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
3928 return SCTP_DISPOSITION_CONSUME;
3931 /*
3932 * Process the SHUTDOWN primitive.
3934 * Section: 10.1:
3935 * C) Shutdown
3937 * Format: SHUTDOWN(association id)
3938 * -> result
3940 * Gracefully closes an association. Any locally queued user data
3941 * will be delivered to the peer. The association will be terminated only
3942 * after the peer acknowledges all the SCTP packets sent. A success code
3943 * will be returned on successful termination of the association. If
3944 * attempting to terminate the association results in a failure, an error
3945 * code shall be returned.
3947 * Mandatory attributes:
3949 * o association id - local handle to the SCTP association
3951 * Optional attributes:
3953 * None.
3955 * The return value is the disposition.
3956 */
3957 sctp_disposition_t sctp_sf_do_9_2_prm_shutdown(
3958 const struct sctp_endpoint *ep,
3959 const struct sctp_association *asoc,
3960 const sctp_subtype_t type,
3961 void *arg,
3962 sctp_cmd_seq_t *commands)
3964 int disposition;
3966 /* From 9.2 Shutdown of an Association
3967 * Upon receipt of the SHUTDOWN primitive from its upper
3968 * layer, the endpoint enters SHUTDOWN-PENDING state and
3969 * remains there until all outstanding data has been
3970 * acknowledged by its peer. The endpoint accepts no new data
3971 * from its upper layer, but retransmits data to the far end
3972 * if necessary to fill gaps.
3973 */
3974 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
3975 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
3977 /* sctpimpguide-05 Section 2.12.2
3978 * The sender of the SHUTDOWN MAY also start an overall guard timer
3979 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
3980 */
3981 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
3982 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
3984 disposition = SCTP_DISPOSITION_CONSUME;
3985 if (sctp_outq_is_empty(&asoc->outqueue)) {
3986 disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type,
3987 arg, commands);
3989 return disposition;
3992 /*
3993 * Process the ABORT primitive.
3995 * Section: 10.1:
3996 * C) Abort
3998 * Format: Abort(association id [, cause code])
3999 * -> result
4001 * Ungracefully closes an association. Any locally queued user data
4002 * will be discarded and an ABORT chunk is sent to the peer. A success code
4003 * will be returned on successful abortion of the association. If
4004 * attempting to abort the association results in a failure, an error
4005 * code shall be returned.
4007 * Mandatory attributes:
4009 * o association id - local handle to the SCTP association
4011 * Optional attributes:
4013 * o cause code - reason of the abort to be passed to the peer
4015 * None.
4017 * The return value is the disposition.
4018 */
4019 sctp_disposition_t sctp_sf_do_9_1_prm_abort(
4020 const struct sctp_endpoint *ep,
4021 const struct sctp_association *asoc,
4022 const sctp_subtype_t type,
4023 void *arg,
4024 sctp_cmd_seq_t *commands)
4026 /* From 9.1 Abort of an Association
4027 * Upon receipt of the ABORT primitive from its upper
4028 * layer, the endpoint enters CLOSED state and
4029 * discard all outstanding data has been
4030 * acknowledged by its peer. The endpoint accepts no new data
4031 * from its upper layer, but retransmits data to the far end
4032 * if necessary to fill gaps.
4033 */
4034 struct sctp_chunk *abort = arg;
4035 sctp_disposition_t retval;
4037 retval = SCTP_DISPOSITION_CONSUME;
4039 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4041 /* Even if we can't send the ABORT due to low memory delete the
4042 * TCB. This is a departure from our typical NOMEM handling.
4043 */
4045 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4046 SCTP_ERROR(ECONNABORTED));
4047 /* Delete the established association. */
4048 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4049 SCTP_U32(SCTP_ERROR_USER_ABORT));
4051 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4052 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
4054 return retval;
4057 /* We tried an illegal operation on an association which is closed. */
4058 sctp_disposition_t sctp_sf_error_closed(const struct sctp_endpoint *ep,
4059 const struct sctp_association *asoc,
4060 const sctp_subtype_t type,
4061 void *arg,
4062 sctp_cmd_seq_t *commands)
4064 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR, SCTP_ERROR(-EINVAL));
4065 return SCTP_DISPOSITION_CONSUME;
4068 /* We tried an illegal operation on an association which is shutting
4069 * down.
4070 */
4071 sctp_disposition_t sctp_sf_error_shutdown(const struct sctp_endpoint *ep,
4072 const struct sctp_association *asoc,
4073 const sctp_subtype_t type,
4074 void *arg,
4075 sctp_cmd_seq_t *commands)
4077 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_ERROR,
4078 SCTP_ERROR(-ESHUTDOWN));
4079 return SCTP_DISPOSITION_CONSUME;
4082 /*
4083 * sctp_cookie_wait_prm_shutdown
4085 * Section: 4 Note: 2
4086 * Verification Tag:
4087 * Inputs
4088 * (endpoint, asoc)
4090 * The RFC does not explicitly address this issue, but is the route through the
4091 * state table when someone issues a shutdown while in COOKIE_WAIT state.
4093 * Outputs
4094 * (timers)
4095 */
4096 sctp_disposition_t sctp_sf_cookie_wait_prm_shutdown(
4097 const struct sctp_endpoint *ep,
4098 const struct sctp_association *asoc,
4099 const sctp_subtype_t type,
4100 void *arg,
4101 sctp_cmd_seq_t *commands)
4103 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4104 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4106 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4107 SCTP_STATE(SCTP_STATE_CLOSED));
4109 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS);
4111 sctp_add_cmd_sf(commands, SCTP_CMD_DELETE_TCB, SCTP_NULL());
4113 return SCTP_DISPOSITION_DELETE_TCB;
4116 /*
4117 * sctp_cookie_echoed_prm_shutdown
4119 * Section: 4 Note: 2
4120 * Verification Tag:
4121 * Inputs
4122 * (endpoint, asoc)
4124 * The RFC does not explcitly address this issue, but is the route through the
4125 * state table when someone issues a shutdown while in COOKIE_ECHOED state.
4127 * Outputs
4128 * (timers)
4129 */
4130 sctp_disposition_t sctp_sf_cookie_echoed_prm_shutdown(
4131 const struct sctp_endpoint *ep,
4132 const struct sctp_association *asoc,
4133 const sctp_subtype_t type,
4134 void *arg, sctp_cmd_seq_t *commands)
4136 /* There is a single T1 timer, so we should be able to use
4137 * common function with the COOKIE-WAIT state.
4138 */
4139 return sctp_sf_cookie_wait_prm_shutdown(ep, asoc, type, arg, commands);
4142 /*
4143 * sctp_sf_cookie_wait_prm_abort
4145 * Section: 4 Note: 2
4146 * Verification Tag:
4147 * Inputs
4148 * (endpoint, asoc)
4150 * The RFC does not explicitly address this issue, but is the route through the
4151 * state table when someone issues an abort while in COOKIE_WAIT state.
4153 * Outputs
4154 * (timers)
4155 */
4156 sctp_disposition_t sctp_sf_cookie_wait_prm_abort(
4157 const struct sctp_endpoint *ep,
4158 const struct sctp_association *asoc,
4159 const sctp_subtype_t type,
4160 void *arg,
4161 sctp_cmd_seq_t *commands)
4163 struct sctp_chunk *abort = arg;
4164 sctp_disposition_t retval;
4166 /* Stop T1-init timer */
4167 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4168 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4169 retval = SCTP_DISPOSITION_CONSUME;
4171 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(abort));
4173 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4174 SCTP_STATE(SCTP_STATE_CLOSED));
4176 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4178 /* Even if we can't send the ABORT due to low memory delete the
4179 * TCB. This is a departure from our typical NOMEM handling.
4180 */
4182 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4183 SCTP_ERROR(ECONNREFUSED));
4184 /* Delete the established association. */
4185 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
4186 SCTP_U32(SCTP_ERROR_USER_ABORT));
4188 return retval;
4191 /*
4192 * sctp_sf_cookie_echoed_prm_abort
4194 * Section: 4 Note: 3
4195 * Verification Tag:
4196 * Inputs
4197 * (endpoint, asoc)
4199 * The RFC does not explcitly address this issue, but is the route through the
4200 * state table when someone issues an abort while in COOKIE_ECHOED state.
4202 * Outputs
4203 * (timers)
4204 */
4205 sctp_disposition_t sctp_sf_cookie_echoed_prm_abort(
4206 const struct sctp_endpoint *ep,
4207 const struct sctp_association *asoc,
4208 const sctp_subtype_t type,
4209 void *arg,
4210 sctp_cmd_seq_t *commands)
4212 /* There is a single T1 timer, so we should be able to use
4213 * common function with the COOKIE-WAIT state.
4214 */
4215 return sctp_sf_cookie_wait_prm_abort(ep, asoc, type, arg, commands);
4218 /*
4219 * sctp_sf_shutdown_pending_prm_abort
4221 * Inputs
4222 * (endpoint, asoc)
4224 * The RFC does not explicitly address this issue, but is the route through the
4225 * state table when someone issues an abort while in SHUTDOWN-PENDING state.
4227 * Outputs
4228 * (timers)
4229 */
4230 sctp_disposition_t sctp_sf_shutdown_pending_prm_abort(
4231 const struct sctp_endpoint *ep,
4232 const struct sctp_association *asoc,
4233 const sctp_subtype_t type,
4234 void *arg,
4235 sctp_cmd_seq_t *commands)
4237 /* Stop the T5-shutdown guard timer. */
4238 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4239 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4241 return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands);
4244 /*
4245 * sctp_sf_shutdown_sent_prm_abort
4247 * Inputs
4248 * (endpoint, asoc)
4250 * The RFC does not explicitly address this issue, but is the route through the
4251 * state table when someone issues an abort while in SHUTDOWN-SENT state.
4253 * Outputs
4254 * (timers)
4255 */
4256 sctp_disposition_t sctp_sf_shutdown_sent_prm_abort(
4257 const struct sctp_endpoint *ep,
4258 const struct sctp_association *asoc,
4259 const sctp_subtype_t type,
4260 void *arg,
4261 sctp_cmd_seq_t *commands)
4263 /* Stop the T2-shutdown timer. */
4264 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4265 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4267 /* Stop the T5-shutdown guard timer. */
4268 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4269 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4271 return sctp_sf_do_9_1_prm_abort(ep, asoc, type, arg, commands);
4274 /*
4275 * sctp_sf_cookie_echoed_prm_abort
4277 * Inputs
4278 * (endpoint, asoc)
4280 * The RFC does not explcitly address this issue, but is the route through the
4281 * state table when someone issues an abort while in COOKIE_ECHOED state.
4283 * Outputs
4284 * (timers)
4285 */
4286 sctp_disposition_t sctp_sf_shutdown_ack_sent_prm_abort(
4287 const struct sctp_endpoint *ep,
4288 const struct sctp_association *asoc,
4289 const sctp_subtype_t type,
4290 void *arg,
4291 sctp_cmd_seq_t *commands)
4293 /* The same T2 timer, so we should be able to use
4294 * common function with the SHUTDOWN-SENT state.
4295 */
4296 return sctp_sf_shutdown_sent_prm_abort(ep, asoc, type, arg, commands);
4299 /*
4300 * Process the REQUESTHEARTBEAT primitive
4302 * 10.1 ULP-to-SCTP
4303 * J) Request Heartbeat
4305 * Format: REQUESTHEARTBEAT(association id, destination transport address)
4307 * -> result
4309 * Instructs the local endpoint to perform a HeartBeat on the specified
4310 * destination transport address of the given association. The returned
4311 * result should indicate whether the transmission of the HEARTBEAT
4312 * chunk to the destination address is successful.
4314 * Mandatory attributes:
4316 * o association id - local handle to the SCTP association
4318 * o destination transport address - the transport address of the
4319 * association on which a heartbeat should be issued.
4320 */
4321 sctp_disposition_t sctp_sf_do_prm_requestheartbeat(
4322 const struct sctp_endpoint *ep,
4323 const struct sctp_association *asoc,
4324 const sctp_subtype_t type,
4325 void *arg,
4326 sctp_cmd_seq_t *commands)
4328 return sctp_sf_heartbeat(ep, asoc, type, (struct sctp_transport *)arg,
4329 commands);
4332 /*
4333 * ADDIP Section 4.1 ASCONF Chunk Procedures
4334 * When an endpoint has an ASCONF signaled change to be sent to the
4335 * remote endpoint it should do A1 to A9
4336 */
4337 sctp_disposition_t sctp_sf_do_prm_asconf(const struct sctp_endpoint *ep,
4338 const struct sctp_association *asoc,
4339 const sctp_subtype_t type,
4340 void *arg,
4341 sctp_cmd_seq_t *commands)
4343 struct sctp_chunk *chunk = arg;
4345 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
4346 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4347 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
4348 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(chunk));
4349 return SCTP_DISPOSITION_CONSUME;
4352 /*
4353 * Ignore the primitive event
4355 * The return value is the disposition of the primitive.
4356 */
4357 sctp_disposition_t sctp_sf_ignore_primitive(
4358 const struct sctp_endpoint *ep,
4359 const struct sctp_association *asoc,
4360 const sctp_subtype_t type,
4361 void *arg,
4362 sctp_cmd_seq_t *commands)
4364 SCTP_DEBUG_PRINTK("Primitive type %d is ignored.\n", type.primitive);
4365 return SCTP_DISPOSITION_DISCARD;
4368 /***************************************************************************
4369 * These are the state functions for the OTHER events.
4370 ***************************************************************************/
4372 /*
4373 * Start the shutdown negotiation.
4375 * From Section 9.2:
4376 * Once all its outstanding data has been acknowledged, the endpoint
4377 * shall send a SHUTDOWN chunk to its peer including in the Cumulative
4378 * TSN Ack field the last sequential TSN it has received from the peer.
4379 * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT
4380 * state. If the timer expires, the endpoint must re-send the SHUTDOWN
4381 * with the updated last sequential TSN received from its peer.
4383 * The return value is the disposition.
4384 */
4385 sctp_disposition_t sctp_sf_do_9_2_start_shutdown(
4386 const struct sctp_endpoint *ep,
4387 const struct sctp_association *asoc,
4388 const sctp_subtype_t type,
4389 void *arg,
4390 sctp_cmd_seq_t *commands)
4392 struct sctp_chunk *reply;
4394 /* Once all its outstanding data has been acknowledged, the
4395 * endpoint shall send a SHUTDOWN chunk to its peer including
4396 * in the Cumulative TSN Ack field the last sequential TSN it
4397 * has received from the peer.
4398 */
4399 reply = sctp_make_shutdown(asoc, NULL);
4400 if (!reply)
4401 goto nomem;
4403 /* Set the transport for the SHUTDOWN chunk and the timeout for the
4404 * T2-shutdown timer.
4405 */
4406 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
4408 /* It shall then start the T2-shutdown timer */
4409 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4410 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4412 if (asoc->autoclose)
4413 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4414 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
4416 /* and enter the SHUTDOWN-SENT state. */
4417 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4418 SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT));
4420 /* sctp-implguide 2.10 Issues with Heartbeating and failover
4422 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
4423 * or SHUTDOWN-ACK.
4424 */
4425 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
4427 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
4429 return SCTP_DISPOSITION_CONSUME;
4431 nomem:
4432 return SCTP_DISPOSITION_NOMEM;
4435 /*
4436 * Generate a SHUTDOWN ACK now that everything is SACK'd.
4438 * From Section 9.2:
4440 * If it has no more outstanding DATA chunks, the SHUTDOWN receiver
4441 * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own,
4442 * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the
4443 * endpoint must re-send the SHUTDOWN ACK.
4445 * The return value is the disposition.
4446 */
4447 sctp_disposition_t sctp_sf_do_9_2_shutdown_ack(
4448 const struct sctp_endpoint *ep,
4449 const struct sctp_association *asoc,
4450 const sctp_subtype_t type,
4451 void *arg,
4452 sctp_cmd_seq_t *commands)
4454 struct sctp_chunk *chunk = (struct sctp_chunk *) arg;
4455 struct sctp_chunk *reply;
4457 /* There are 2 ways of getting here:
4458 * 1) called in response to a SHUTDOWN chunk
4459 * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued.
4461 * For the case (2), the arg parameter is set to NULL. We need
4462 * to check that we have a chunk before accessing it's fields.
4463 */
4464 if (chunk) {
4465 if (!sctp_vtag_verify(chunk, asoc))
4466 return sctp_sf_pdiscard(ep, asoc, type, arg, commands);
4468 /* Make sure that the SHUTDOWN chunk has a valid length. */
4469 if (!sctp_chunk_length_valid(chunk, sizeof(struct sctp_shutdown_chunk_t)))
4470 return sctp_sf_violation_chunklen(ep, asoc, type, arg,
4471 commands);
4474 /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
4475 * shall send a SHUTDOWN ACK ...
4476 */
4477 reply = sctp_make_shutdown_ack(asoc, chunk);
4478 if (!reply)
4479 goto nomem;
4481 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
4482 * the T2-shutdown timer.
4483 */
4484 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
4486 /* and start/restart a T2-shutdown timer of its own, */
4487 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
4488 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4490 if (asoc->autoclose)
4491 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4492 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE));
4494 /* Enter the SHUTDOWN-ACK-SENT state. */
4495 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4496 SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT));
4498 /* sctp-implguide 2.10 Issues with Heartbeating and failover
4500 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
4501 * or SHUTDOWN-ACK.
4502 */
4503 sctp_add_cmd_sf(commands, SCTP_CMD_HB_TIMERS_STOP, SCTP_NULL());
4505 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
4507 return SCTP_DISPOSITION_CONSUME;
4509 nomem:
4510 return SCTP_DISPOSITION_NOMEM;
4513 /*
4514 * Ignore the event defined as other
4516 * The return value is the disposition of the event.
4517 */
4518 sctp_disposition_t sctp_sf_ignore_other(const struct sctp_endpoint *ep,
4519 const struct sctp_association *asoc,
4520 const sctp_subtype_t type,
4521 void *arg,
4522 sctp_cmd_seq_t *commands)
4524 SCTP_DEBUG_PRINTK("The event other type %d is ignored\n", type.other);
4525 return SCTP_DISPOSITION_DISCARD;
4528 /************************************************************
4529 * These are the state functions for handling timeout events.
4530 ************************************************************/
4532 /*
4533 * RTX Timeout
4535 * Section: 6.3.3 Handle T3-rtx Expiration
4537 * Whenever the retransmission timer T3-rtx expires for a destination
4538 * address, do the following:
4539 * [See below]
4541 * The return value is the disposition of the chunk.
4542 */
4543 sctp_disposition_t sctp_sf_do_6_3_3_rtx(const struct sctp_endpoint *ep,
4544 const struct sctp_association *asoc,
4545 const sctp_subtype_t type,
4546 void *arg,
4547 sctp_cmd_seq_t *commands)
4549 struct sctp_transport *transport = arg;
4551 if (asoc->overall_error_count >= asoc->max_retrans) {
4552 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4553 SCTP_ERROR(ETIMEDOUT));
4554 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
4555 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4556 SCTP_U32(SCTP_ERROR_NO_ERROR));
4557 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4558 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
4559 return SCTP_DISPOSITION_DELETE_TCB;
4562 /* E1) For the destination address for which the timer
4563 * expires, adjust its ssthresh with rules defined in Section
4564 * 7.2.3 and set the cwnd <- MTU.
4565 */
4567 /* E2) For the destination address for which the timer
4568 * expires, set RTO <- RTO * 2 ("back off the timer"). The
4569 * maximum value discussed in rule C7 above (RTO.max) may be
4570 * used to provide an upper bound to this doubling operation.
4571 */
4573 /* E3) Determine how many of the earliest (i.e., lowest TSN)
4574 * outstanding DATA chunks for the address for which the
4575 * T3-rtx has expired will fit into a single packet, subject
4576 * to the MTU constraint for the path corresponding to the
4577 * destination transport address to which the retransmission
4578 * is being sent (this may be different from the address for
4579 * which the timer expires [see Section 6.4]). Call this
4580 * value K. Bundle and retransmit those K DATA chunks in a
4581 * single packet to the destination endpoint.
4583 * Note: Any DATA chunks that were sent to the address for
4584 * which the T3-rtx timer expired but did not fit in one MTU
4585 * (rule E3 above), should be marked for retransmission and
4586 * sent as soon as cwnd allows (normally when a SACK arrives).
4587 */
4589 /* NB: Rules E4 and F1 are implicit in R1. */
4590 sctp_add_cmd_sf(commands, SCTP_CMD_RETRAN, SCTP_TRANSPORT(transport));
4592 /* Do some failure management (Section 8.2). */
4593 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
4595 return SCTP_DISPOSITION_CONSUME;
4598 /*
4599 * Generate delayed SACK on timeout
4601 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
4603 * The guidelines on delayed acknowledgement algorithm specified in
4604 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
4605 * acknowledgement SHOULD be generated for at least every second packet
4606 * (not every second DATA chunk) received, and SHOULD be generated
4607 * within 200 ms of the arrival of any unacknowledged DATA chunk. In
4608 * some situations it may be beneficial for an SCTP transmitter to be
4609 * more conservative than the algorithms detailed in this document
4610 * allow. However, an SCTP transmitter MUST NOT be more aggressive than
4611 * the following algorithms allow.
4612 */
4613 sctp_disposition_t sctp_sf_do_6_2_sack(const struct sctp_endpoint *ep,
4614 const struct sctp_association *asoc,
4615 const sctp_subtype_t type,
4616 void *arg,
4617 sctp_cmd_seq_t *commands)
4619 sctp_add_cmd_sf(commands, SCTP_CMD_GEN_SACK, SCTP_FORCE());
4620 return SCTP_DISPOSITION_CONSUME;
4623 /*
4624 * sctp_sf_t1_init_timer_expire
4626 * Section: 4 Note: 2
4627 * Verification Tag:
4628 * Inputs
4629 * (endpoint, asoc)
4631 * RFC 2960 Section 4 Notes
4632 * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT
4633 * and re-start the T1-init timer without changing state. This MUST
4634 * be repeated up to 'Max.Init.Retransmits' times. After that, the
4635 * endpoint MUST abort the initialization process and report the
4636 * error to SCTP user.
4638 * Outputs
4639 * (timers, events)
4641 */
4642 sctp_disposition_t sctp_sf_t1_init_timer_expire(const struct sctp_endpoint *ep,
4643 const struct sctp_association *asoc,
4644 const sctp_subtype_t type,
4645 void *arg,
4646 sctp_cmd_seq_t *commands)
4648 struct sctp_chunk *repl = NULL;
4649 struct sctp_bind_addr *bp;
4650 int attempts = asoc->init_err_counter + 1;
4652 SCTP_DEBUG_PRINTK("Timer T1 expired (INIT).\n");
4654 if (attempts <= asoc->max_init_attempts) {
4655 bp = (struct sctp_bind_addr *) &asoc->base.bind_addr;
4656 repl = sctp_make_init(asoc, bp, GFP_ATOMIC, 0);
4657 if (!repl)
4658 return SCTP_DISPOSITION_NOMEM;
4660 /* Choose transport for INIT. */
4661 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_CHOOSE_TRANSPORT,
4662 SCTP_CHUNK(repl));
4664 /* Issue a sideeffect to do the needed accounting. */
4665 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_RESTART,
4666 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT));
4668 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
4669 } else {
4670 SCTP_DEBUG_PRINTK("Giving up on INIT, attempts: %d"
4671 " max_init_attempts: %d\n",
4672 attempts, asoc->max_init_attempts);
4673 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4674 SCTP_ERROR(ETIMEDOUT));
4675 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
4676 SCTP_U32(SCTP_ERROR_NO_ERROR));
4677 return SCTP_DISPOSITION_DELETE_TCB;
4680 return SCTP_DISPOSITION_CONSUME;
4683 /*
4684 * sctp_sf_t1_cookie_timer_expire
4686 * Section: 4 Note: 2
4687 * Verification Tag:
4688 * Inputs
4689 * (endpoint, asoc)
4691 * RFC 2960 Section 4 Notes
4692 * 3) If the T1-cookie timer expires, the endpoint MUST retransmit
4693 * COOKIE ECHO and re-start the T1-cookie timer without changing
4694 * state. This MUST be repeated up to 'Max.Init.Retransmits' times.
4695 * After that, the endpoint MUST abort the initialization process and
4696 * report the error to SCTP user.
4698 * Outputs
4699 * (timers, events)
4701 */
4702 sctp_disposition_t sctp_sf_t1_cookie_timer_expire(const struct sctp_endpoint *ep,
4703 const struct sctp_association *asoc,
4704 const sctp_subtype_t type,
4705 void *arg,
4706 sctp_cmd_seq_t *commands)
4708 struct sctp_chunk *repl = NULL;
4709 int attempts = asoc->init_err_counter + 1;
4711 SCTP_DEBUG_PRINTK("Timer T1 expired (COOKIE-ECHO).\n");
4713 if (attempts <= asoc->max_init_attempts) {
4714 repl = sctp_make_cookie_echo(asoc, NULL);
4715 if (!repl)
4716 return SCTP_DISPOSITION_NOMEM;
4718 /* Issue a sideeffect to do the needed accounting. */
4719 sctp_add_cmd_sf(commands, SCTP_CMD_COOKIEECHO_RESTART,
4720 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE));
4722 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(repl));
4723 } else {
4724 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4725 SCTP_ERROR(ETIMEDOUT));
4726 sctp_add_cmd_sf(commands, SCTP_CMD_INIT_FAILED,
4727 SCTP_U32(SCTP_ERROR_NO_ERROR));
4728 return SCTP_DISPOSITION_DELETE_TCB;
4731 return SCTP_DISPOSITION_CONSUME;
4734 /* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN
4735 * with the updated last sequential TSN received from its peer.
4737 * An endpoint should limit the number of retransmissions of the
4738 * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'.
4739 * If this threshold is exceeded the endpoint should destroy the TCB and
4740 * MUST report the peer endpoint unreachable to the upper layer (and
4741 * thus the association enters the CLOSED state). The reception of any
4742 * packet from its peer (i.e. as the peer sends all of its queued DATA
4743 * chunks) should clear the endpoint's retransmission count and restart
4744 * the T2-Shutdown timer, giving its peer ample opportunity to transmit
4745 * all of its queued DATA chunks that have not yet been sent.
4746 */
4747 sctp_disposition_t sctp_sf_t2_timer_expire(const struct sctp_endpoint *ep,
4748 const struct sctp_association *asoc,
4749 const sctp_subtype_t type,
4750 void *arg,
4751 sctp_cmd_seq_t *commands)
4753 struct sctp_chunk *reply = NULL;
4755 SCTP_DEBUG_PRINTK("Timer T2 expired.\n");
4756 if (asoc->overall_error_count >= asoc->max_retrans) {
4757 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4758 SCTP_ERROR(ETIMEDOUT));
4759 /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
4760 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4761 SCTP_U32(SCTP_ERROR_NO_ERROR));
4762 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4763 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
4764 return SCTP_DISPOSITION_DELETE_TCB;
4767 switch (asoc->state) {
4768 case SCTP_STATE_SHUTDOWN_SENT:
4769 reply = sctp_make_shutdown(asoc, NULL);
4770 break;
4772 case SCTP_STATE_SHUTDOWN_ACK_SENT:
4773 reply = sctp_make_shutdown_ack(asoc, NULL);
4774 break;
4776 default:
4777 BUG();
4778 break;
4779 };
4781 if (!reply)
4782 goto nomem;
4784 /* Do some failure management (Section 8.2). */
4785 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE,
4786 SCTP_TRANSPORT(asoc->shutdown_last_sent_to));
4788 /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for
4789 * the T2-shutdown timer.
4790 */
4791 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T2, SCTP_CHUNK(reply));
4793 /* Restart the T2-shutdown timer. */
4794 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
4795 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN));
4796 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
4797 return SCTP_DISPOSITION_CONSUME;
4799 nomem:
4800 return SCTP_DISPOSITION_NOMEM;
4803 /*
4804 * ADDIP Section 4.1 ASCONF CHunk Procedures
4805 * If the T4 RTO timer expires the endpoint should do B1 to B5
4806 */
4807 sctp_disposition_t sctp_sf_t4_timer_expire(
4808 const struct sctp_endpoint *ep,
4809 const struct sctp_association *asoc,
4810 const sctp_subtype_t type,
4811 void *arg,
4812 sctp_cmd_seq_t *commands)
4814 struct sctp_chunk *chunk = asoc->addip_last_asconf;
4815 struct sctp_transport *transport = chunk->transport;
4817 /* ADDIP 4.1 B1) Increment the error counters and perform path failure
4818 * detection on the appropriate destination address as defined in
4819 * RFC2960 [5] section 8.1 and 8.2.
4820 */
4821 sctp_add_cmd_sf(commands, SCTP_CMD_STRIKE, SCTP_TRANSPORT(transport));
4823 /* Reconfig T4 timer and transport. */
4824 sctp_add_cmd_sf(commands, SCTP_CMD_SETUP_T4, SCTP_CHUNK(chunk));
4826 /* ADDIP 4.1 B2) Increment the association error counters and perform
4827 * endpoint failure detection on the association as defined in
4828 * RFC2960 [5] section 8.1 and 8.2.
4829 * association error counter is incremented in SCTP_CMD_STRIKE.
4830 */
4831 if (asoc->overall_error_count >= asoc->max_retrans) {
4832 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_STOP,
4833 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
4834 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4835 SCTP_ERROR(ETIMEDOUT));
4836 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4837 SCTP_U32(SCTP_ERROR_NO_ERROR));
4838 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
4839 SCTP_INC_STATS(SCTP_MIB_CURRESTAB);
4840 return SCTP_DISPOSITION_ABORT;
4843 /* ADDIP 4.1 B3) Back-off the destination address RTO value to which
4844 * the ASCONF chunk was sent by doubling the RTO timer value.
4845 * This is done in SCTP_CMD_STRIKE.
4846 */
4848 /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible
4849 * choose an alternate destination address (please refer to RFC2960
4850 * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this
4851 * chunk, it MUST be the same (including its serial number) as the last
4852 * ASCONF sent.
4853 */
4854 sctp_chunk_hold(asoc->addip_last_asconf);
4855 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
4856 SCTP_CHUNK(asoc->addip_last_asconf));
4858 /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different
4859 * destination is selected, then the RTO used will be that of the new
4860 * destination address.
4861 */
4862 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_RESTART,
4863 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO));
4865 return SCTP_DISPOSITION_CONSUME;
4868 /* sctpimpguide-05 Section 2.12.2
4869 * The sender of the SHUTDOWN MAY also start an overall guard timer
4870 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
4871 * At the expiration of this timer the sender SHOULD abort the association
4872 * by sending an ABORT chunk.
4873 */
4874 sctp_disposition_t sctp_sf_t5_timer_expire(const struct sctp_endpoint *ep,
4875 const struct sctp_association *asoc,
4876 const sctp_subtype_t type,
4877 void *arg,
4878 sctp_cmd_seq_t *commands)
4880 struct sctp_chunk *reply = NULL;
4882 SCTP_DEBUG_PRINTK("Timer T5 expired.\n");
4884 reply = sctp_make_abort(asoc, NULL, 0);
4885 if (!reply)
4886 goto nomem;
4888 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY, SCTP_CHUNK(reply));
4889 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
4890 SCTP_ERROR(ETIMEDOUT));
4891 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
4892 SCTP_U32(SCTP_ERROR_NO_ERROR));
4894 return SCTP_DISPOSITION_DELETE_TCB;
4895 nomem:
4896 return SCTP_DISPOSITION_NOMEM;
4899 /* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires,
4900 * the association is automatically closed by starting the shutdown process.
4901 * The work that needs to be done is same as when SHUTDOWN is initiated by
4902 * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown().
4903 */
4904 sctp_disposition_t sctp_sf_autoclose_timer_expire(
4905 const struct sctp_endpoint *ep,
4906 const struct sctp_association *asoc,
4907 const sctp_subtype_t type,
4908 void *arg,
4909 sctp_cmd_seq_t *commands)
4911 int disposition;
4913 /* From 9.2 Shutdown of an Association
4914 * Upon receipt of the SHUTDOWN primitive from its upper
4915 * layer, the endpoint enters SHUTDOWN-PENDING state and
4916 * remains there until all outstanding data has been
4917 * acknowledged by its peer. The endpoint accepts no new data
4918 * from its upper layer, but retransmits data to the far end
4919 * if necessary to fill gaps.
4920 */
4921 sctp_add_cmd_sf(commands, SCTP_CMD_NEW_STATE,
4922 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING));
4924 /* sctpimpguide-05 Section 2.12.2
4925 * The sender of the SHUTDOWN MAY also start an overall guard timer
4926 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
4927 */
4928 sctp_add_cmd_sf(commands, SCTP_CMD_TIMER_START,
4929 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD));
4930 disposition = SCTP_DISPOSITION_CONSUME;
4931 if (sctp_outq_is_empty(&asoc->outqueue)) {
4932 disposition = sctp_sf_do_9_2_start_shutdown(ep, asoc, type,
4933 arg, commands);
4935 return disposition;
4938 /*****************************************************************************
4939 * These are sa state functions which could apply to all types of events.
4940 ****************************************************************************/
4942 /*
4943 * This table entry is not implemented.
4945 * Inputs
4946 * (endpoint, asoc, chunk)
4948 * The return value is the disposition of the chunk.
4949 */
4950 sctp_disposition_t sctp_sf_not_impl(const struct sctp_endpoint *ep,
4951 const struct sctp_association *asoc,
4952 const sctp_subtype_t type,
4953 void *arg,
4954 sctp_cmd_seq_t *commands)
4956 return SCTP_DISPOSITION_NOT_IMPL;
4959 /*
4960 * This table entry represents a bug.
4962 * Inputs
4963 * (endpoint, asoc, chunk)
4965 * The return value is the disposition of the chunk.
4966 */
4967 sctp_disposition_t sctp_sf_bug(const struct sctp_endpoint *ep,
4968 const struct sctp_association *asoc,
4969 const sctp_subtype_t type,
4970 void *arg,
4971 sctp_cmd_seq_t *commands)
4973 return SCTP_DISPOSITION_BUG;
4976 /*
4977 * This table entry represents the firing of a timer in the wrong state.
4978 * Since timer deletion cannot be guaranteed a timer 'may' end up firing
4979 * when the association is in the wrong state. This event should
4980 * be ignored, so as to prevent any rearming of the timer.
4982 * Inputs
4983 * (endpoint, asoc, chunk)
4985 * The return value is the disposition of the chunk.
4986 */
4987 sctp_disposition_t sctp_sf_timer_ignore(const struct sctp_endpoint *ep,
4988 const struct sctp_association *asoc,
4989 const sctp_subtype_t type,
4990 void *arg,
4991 sctp_cmd_seq_t *commands)
4993 SCTP_DEBUG_PRINTK("Timer %d ignored.\n", type.chunk);
4994 return SCTP_DISPOSITION_CONSUME;
4997 /********************************************************************
4998 * 2nd Level Abstractions
4999 ********************************************************************/
5001 /* Pull the SACK chunk based on the SACK header. */
5002 static struct sctp_sackhdr *sctp_sm_pull_sack(struct sctp_chunk *chunk)
5004 struct sctp_sackhdr *sack;
5005 unsigned int len;
5006 __u16 num_blocks;
5007 __u16 num_dup_tsns;
5009 /* Protect ourselves from reading too far into
5010 * the skb from a bogus sender.
5011 */
5012 sack = (struct sctp_sackhdr *) chunk->skb->data;
5014 num_blocks = ntohs(sack->num_gap_ack_blocks);
5015 num_dup_tsns = ntohs(sack->num_dup_tsns);
5016 len = sizeof(struct sctp_sackhdr);
5017 len += (num_blocks + num_dup_tsns) * sizeof(__u32);
5018 if (len > chunk->skb->len)
5019 return NULL;
5021 skb_pull(chunk->skb, len);
5023 return sack;
5026 /* Create an ABORT packet to be sent as a response, with the specified
5027 * error causes.
5028 */
5029 static struct sctp_packet *sctp_abort_pkt_new(const struct sctp_endpoint *ep,
5030 const struct sctp_association *asoc,
5031 struct sctp_chunk *chunk,
5032 const void *payload,
5033 size_t paylen)
5035 struct sctp_packet *packet;
5036 struct sctp_chunk *abort;
5038 packet = sctp_ootb_pkt_new(asoc, chunk);
5040 if (packet) {
5041 /* Make an ABORT.
5042 * The T bit will be set if the asoc is NULL.
5043 */
5044 abort = sctp_make_abort(asoc, chunk, paylen);
5045 if (!abort) {
5046 sctp_ootb_pkt_free(packet);
5047 return NULL;
5050 /* Reflect vtag if T-Bit is set */
5051 if (sctp_test_T_bit(abort))
5052 packet->vtag = ntohl(chunk->sctp_hdr->vtag);
5054 /* Add specified error causes, i.e., payload, to the
5055 * end of the chunk.
5056 */
5057 sctp_addto_chunk(abort, paylen, payload);
5059 /* Set the skb to the belonging sock for accounting. */
5060 abort->skb->sk = ep->base.sk;
5062 sctp_packet_append_chunk(packet, abort);
5066 return packet;
5069 /* Allocate a packet for responding in the OOTB conditions. */
5070 static struct sctp_packet *sctp_ootb_pkt_new(const struct sctp_association *asoc,
5071 const struct sctp_chunk *chunk)
5073 struct sctp_packet *packet;
5074 struct sctp_transport *transport;
5075 __u16 sport;
5076 __u16 dport;
5077 __u32 vtag;
5079 /* Get the source and destination port from the inbound packet. */
5080 sport = ntohs(chunk->sctp_hdr->dest);
5081 dport = ntohs(chunk->sctp_hdr->source);
5083 /* The V-tag is going to be the same as the inbound packet if no
5084 * association exists, otherwise, use the peer's vtag.
5085 */
5086 if (asoc) {
5087 vtag = asoc->peer.i.init_tag;
5088 } else {
5089 /* Special case the INIT and stale COOKIE_ECHO as there is no
5090 * vtag yet.
5091 */
5092 switch(chunk->chunk_hdr->type) {
5093 case SCTP_CID_INIT:
5095 sctp_init_chunk_t *init;
5097 init = (sctp_init_chunk_t *)chunk->chunk_hdr;
5098 vtag = ntohl(init->init_hdr.init_tag);
5099 break;
5101 default:
5102 vtag = ntohl(chunk->sctp_hdr->vtag);
5103 break;
5107 /* Make a transport for the bucket, Eliza... */
5108 transport = sctp_transport_new(sctp_source(chunk), GFP_ATOMIC);
5109 if (!transport)
5110 goto nomem;
5112 /* Cache a route for the transport with the chunk's destination as
5113 * the source address.
5114 */
5115 sctp_transport_route(transport, (union sctp_addr *)&chunk->dest,
5116 sctp_sk(sctp_get_ctl_sock()));
5118 packet = sctp_packet_init(&transport->packet, transport, sport, dport);
5119 packet = sctp_packet_config(packet, vtag, 0);
5121 return packet;
5123 nomem:
5124 return NULL;
5127 /* Free the packet allocated earlier for responding in the OOTB condition. */
5128 void sctp_ootb_pkt_free(struct sctp_packet *packet)
5130 sctp_transport_free(packet->transport);
5133 /* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */
5134 static void sctp_send_stale_cookie_err(const struct sctp_endpoint *ep,
5135 const struct sctp_association *asoc,
5136 const struct sctp_chunk *chunk,
5137 sctp_cmd_seq_t *commands,
5138 struct sctp_chunk *err_chunk)
5140 struct sctp_packet *packet;
5142 if (err_chunk) {
5143 packet = sctp_ootb_pkt_new(asoc, chunk);
5144 if (packet) {
5145 struct sctp_signed_cookie *cookie;
5147 /* Override the OOTB vtag from the cookie. */
5148 cookie = chunk->subh.cookie_hdr;
5149 packet->vtag = cookie->c.peer_vtag;
5151 /* Set the skb to the belonging sock for accounting. */
5152 err_chunk->skb->sk = ep->base.sk;
5153 sctp_packet_append_chunk(packet, err_chunk);
5154 sctp_add_cmd_sf(commands, SCTP_CMD_SEND_PKT,
5155 SCTP_PACKET(packet));
5156 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS);
5157 } else
5158 sctp_chunk_free (err_chunk);
5163 /* Process a data chunk */
5164 static int sctp_eat_data(const struct sctp_association *asoc,
5165 struct sctp_chunk *chunk,
5166 sctp_cmd_seq_t *commands)
5168 sctp_datahdr_t *data_hdr;
5169 struct sctp_chunk *err;
5170 size_t datalen;
5171 sctp_verb_t deliver;
5172 int tmp;
5173 __u32 tsn;
5174 int account_value;
5175 struct sctp_tsnmap *map = (struct sctp_tsnmap *)&asoc->peer.tsn_map;
5176 struct sock *sk = asoc->base.sk;
5177 int rcvbuf_over = 0;
5179 data_hdr = chunk->subh.data_hdr = (sctp_datahdr_t *)chunk->skb->data;
5180 skb_pull(chunk->skb, sizeof(sctp_datahdr_t));
5182 tsn = ntohl(data_hdr->tsn);
5183 SCTP_DEBUG_PRINTK("eat_data: TSN 0x%x.\n", tsn);
5185 /* ASSERT: Now skb->data is really the user data. */
5187 /*
5188 * If we are established, and we have used up our receive buffer
5189 * memory, think about droping the frame.
5190 * Note that we have an opportunity to improve performance here.
5191 * If we accept one chunk from an skbuff, we have to keep all the
5192 * memory of that skbuff around until the chunk is read into user
5193 * space. Therefore, once we accept 1 chunk we may as well accept all
5194 * remaining chunks in the skbuff. The data_accepted flag helps us do
5195 * that.
5196 */
5197 if ((asoc->state == SCTP_STATE_ESTABLISHED) && (!chunk->data_accepted)) {
5198 /*
5199 * If the receive buffer policy is 1, then each
5200 * association can allocate up to sk_rcvbuf bytes
5201 * otherwise, all the associations in aggregate
5202 * may allocate up to sk_rcvbuf bytes
5203 */
5204 if (asoc->ep->rcvbuf_policy)
5205 account_value = atomic_read(&asoc->rmem_alloc);
5206 else
5207 account_value = atomic_read(&sk->sk_rmem_alloc);
5208 if (account_value > sk->sk_rcvbuf) {
5209 /*
5210 * We need to make forward progress, even when we are
5211 * under memory pressure, so we always allow the
5212 * next tsn after the ctsn ack point to be accepted.
5213 * This lets us avoid deadlocks in which we have to
5214 * drop frames that would otherwise let us drain the
5215 * receive queue.
5216 */
5217 if ((sctp_tsnmap_get_ctsn(map) + 1) != tsn)
5218 return SCTP_IERROR_IGNORE_TSN;
5220 /*
5221 * We're going to accept the frame but we should renege
5222 * to make space for it. This will send us down that
5223 * path later in this function.
5224 */
5225 rcvbuf_over = 1;
5229 /* Process ECN based congestion.
5231 * Since the chunk structure is reused for all chunks within
5232 * a packet, we use ecn_ce_done to track if we've already
5233 * done CE processing for this packet.
5235 * We need to do ECN processing even if we plan to discard the
5236 * chunk later.
5237 */
5239 if (!chunk->ecn_ce_done) {
5240 struct sctp_af *af;
5241 chunk->ecn_ce_done = 1;
5243 af = sctp_get_af_specific(
5244 ipver2af(chunk->skb->nh.iph->version));
5246 if (af && af->is_ce(chunk->skb) && asoc->peer.ecn_capable) {
5247 /* Do real work as sideffect. */
5248 sctp_add_cmd_sf(commands, SCTP_CMD_ECN_CE,
5249 SCTP_U32(tsn));
5253 tmp = sctp_tsnmap_check(&asoc->peer.tsn_map, tsn);
5254 if (tmp < 0) {
5255 /* The TSN is too high--silently discard the chunk and
5256 * count on it getting retransmitted later.
5257 */
5258 return SCTP_IERROR_HIGH_TSN;
5259 } else if (tmp > 0) {
5260 /* This is a duplicate. Record it. */
5261 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_DUP, SCTP_U32(tsn));
5262 return SCTP_IERROR_DUP_TSN;
5265 /* This is a new TSN. */
5267 /* Discard if there is no room in the receive window.
5268 * Actually, allow a little bit of overflow (up to a MTU).
5269 */
5270 datalen = ntohs(chunk->chunk_hdr->length);
5271 datalen -= sizeof(sctp_data_chunk_t);
5273 deliver = SCTP_CMD_CHUNK_ULP;
5275 /* Think about partial delivery. */
5276 if ((datalen >= asoc->rwnd) && (!asoc->ulpq.pd_mode)) {
5278 /* Even if we don't accept this chunk there is
5279 * memory pressure.
5280 */
5281 sctp_add_cmd_sf(commands, SCTP_CMD_PART_DELIVER, SCTP_NULL());
5284 /* Spill over rwnd a little bit. Note: While allowed, this spill over
5285 * seems a bit troublesome in that frag_point varies based on
5286 * PMTU. In cases, such as loopback, this might be a rather
5287 * large spill over.
5288 * NOTE: If we have a full receive buffer here, we only renege if
5289 * our receiver can still make progress without the tsn being
5290 * received. We do this because in the event that the associations
5291 * receive queue is empty we are filling a leading gap, and since
5292 * reneging moves the gap to the end of the tsn stream, we are likely
5293 * to stall again very shortly. Avoiding the renege when we fill a
5294 * leading gap is a good heuristic for avoiding such steady state
5295 * stalls.
5296 */
5297 if (!asoc->rwnd || asoc->rwnd_over ||
5298 (datalen > asoc->rwnd + asoc->frag_point) ||
5299 (rcvbuf_over && (!skb_queue_len(&sk->sk_receive_queue)))) {
5301 /* If this is the next TSN, consider reneging to make
5302 * room. Note: Playing nice with a confused sender. A
5303 * malicious sender can still eat up all our buffer
5304 * space and in the future we may want to detect and
5305 * do more drastic reneging.
5306 */
5307 if (sctp_tsnmap_has_gap(map) &&
5308 (sctp_tsnmap_get_ctsn(map) + 1) == tsn) {
5309 SCTP_DEBUG_PRINTK("Reneging for tsn:%u\n", tsn);
5310 deliver = SCTP_CMD_RENEGE;
5311 } else {
5312 SCTP_DEBUG_PRINTK("Discard tsn: %u len: %Zd, "
5313 "rwnd: %d\n", tsn, datalen,
5314 asoc->rwnd);
5315 return SCTP_IERROR_IGNORE_TSN;
5319 /*
5320 * Section 3.3.10.9 No User Data (9)
5322 * Cause of error
5323 * ---------------
5324 * No User Data: This error cause is returned to the originator of a
5325 * DATA chunk if a received DATA chunk has no user data.
5326 */
5327 if (unlikely(0 == datalen)) {
5328 err = sctp_make_abort_no_data(asoc, chunk, tsn);
5329 if (err) {
5330 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
5331 SCTP_CHUNK(err));
5333 /* We are going to ABORT, so we might as well stop
5334 * processing the rest of the chunks in the packet.
5335 */
5336 sctp_add_cmd_sf(commands, SCTP_CMD_DISCARD_PACKET,SCTP_NULL());
5337 sctp_add_cmd_sf(commands, SCTP_CMD_SET_SK_ERR,
5338 SCTP_ERROR(ECONNABORTED));
5339 sctp_add_cmd_sf(commands, SCTP_CMD_ASSOC_FAILED,
5340 SCTP_U32(SCTP_ERROR_NO_DATA));
5341 SCTP_INC_STATS(SCTP_MIB_ABORTEDS);
5342 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB);
5343 return SCTP_IERROR_NO_DATA;
5346 /* If definately accepting the DATA chunk, record its TSN, otherwise
5347 * wait for renege processing.
5348 */
5349 if (SCTP_CMD_CHUNK_ULP == deliver)
5350 sctp_add_cmd_sf(commands, SCTP_CMD_REPORT_TSN, SCTP_U32(tsn));
5352 chunk->data_accepted = 1;
5354 /* Note: Some chunks may get overcounted (if we drop) or overcounted
5355 * if we renege and the chunk arrives again.
5356 */
5357 if (chunk->chunk_hdr->flags & SCTP_DATA_UNORDERED)
5358 SCTP_INC_STATS(SCTP_MIB_INUNORDERCHUNKS);
5359 else
5360 SCTP_INC_STATS(SCTP_MIB_INORDERCHUNKS);
5362 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
5364 * If an endpoint receive a DATA chunk with an invalid stream
5365 * identifier, it shall acknowledge the reception of the DATA chunk
5366 * following the normal procedure, immediately send an ERROR chunk
5367 * with cause set to "Invalid Stream Identifier" (See Section 3.3.10)
5368 * and discard the DATA chunk.
5369 */
5370 if (ntohs(data_hdr->stream) >= asoc->c.sinit_max_instreams) {
5371 err = sctp_make_op_error(asoc, chunk, SCTP_ERROR_INV_STRM,
5372 &data_hdr->stream,
5373 sizeof(data_hdr->stream));
5374 if (err)
5375 sctp_add_cmd_sf(commands, SCTP_CMD_REPLY,
5376 SCTP_CHUNK(err));
5377 return SCTP_IERROR_BAD_STREAM;
5380 /* Send the data up to the user. Note: Schedule the
5381 * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK
5382 * chunk needs the updated rwnd.
5383 */
5384 sctp_add_cmd_sf(commands, deliver, SCTP_CHUNK(chunk));
5386 return SCTP_IERROR_NO_ERROR;