1 /* SCTP kernel 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.
8 * This is part of the SCTP Linux Kernel Implementation.
10 * These are the state functions for the state machine.
12 * This SCTP implementation is free software;
13 * you can redistribute it and/or modify it under the terms of
14 * the GNU General Public License as published by
15 * the Free Software Foundation; either version 2, or (at your option)
18 * This SCTP implementation is distributed in the hope that it
19 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
20 * ************************
21 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
22 * See the GNU General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with GNU CC; see the file COPYING. If not, write to
26 * the Free Software Foundation, 59 Temple Place - Suite 330,
27 * Boston, MA 02111-1307, USA.
29 * Please send any bug reports or fixes you make to the
31 * lksctp developers <lksctp-developers@lists.sourceforge.net>
33 * Or submit a bug report through the following website:
34 * http://www.sf.net/projects/lksctp
36 * Written or modified by:
37 * La Monte H.P. Yarroll <piggy@acm.org>
38 * Karl Knutson <karl@athena.chicago.il.us>
39 * Mathew Kotowsky <kotowsky@sctp.org>
40 * Sridhar Samudrala <samudrala@us.ibm.com>
41 * Jon Grimm <jgrimm@us.ibm.com>
42 * Hui Huang <hui.huang@nokia.com>
43 * Dajiang Zhang <dajiang.zhang@nokia.com>
44 * Daisy Chang <daisyc@us.ibm.com>
45 * Ardelle Fan <ardelle.fan@intel.com>
46 * Ryan Layer <rmlayer@us.ibm.com>
47 * Kevin Gao <kevin.gao@intel.com>
49 * Any bugs reported given to us we will try to fix... any fixes shared will
50 * be incorporated into the next SCTP release.
53 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
55 #include <linux/types.h>
56 #include <linux/kernel.h>
58 #include <linux/ipv6.h>
59 #include <linux/net.h>
60 #include <linux/inet.h>
61 #include <linux/slab.h>
63 #include <net/inet_ecn.h>
64 #include <linux/skbuff.h>
65 #include <net/sctp/sctp.h>
66 #include <net/sctp/sm.h>
67 #include <net/sctp/structs.h>
69 static struct sctp_packet
*sctp_abort_pkt_new(const struct sctp_endpoint
*ep
,
70 const struct sctp_association
*asoc
,
71 struct sctp_chunk
*chunk
,
74 static int sctp_eat_data(const struct sctp_association
*asoc
,
75 struct sctp_chunk
*chunk
,
76 sctp_cmd_seq_t
*commands
);
77 static struct sctp_packet
*sctp_ootb_pkt_new(const struct sctp_association
*asoc
,
78 const struct sctp_chunk
*chunk
);
79 static void sctp_send_stale_cookie_err(const struct sctp_endpoint
*ep
,
80 const struct sctp_association
*asoc
,
81 const struct sctp_chunk
*chunk
,
82 sctp_cmd_seq_t
*commands
,
83 struct sctp_chunk
*err_chunk
);
84 static sctp_disposition_t
sctp_sf_do_5_2_6_stale(const struct sctp_endpoint
*ep
,
85 const struct sctp_association
*asoc
,
86 const sctp_subtype_t type
,
88 sctp_cmd_seq_t
*commands
);
89 static sctp_disposition_t
sctp_sf_shut_8_4_5(const struct sctp_endpoint
*ep
,
90 const struct sctp_association
*asoc
,
91 const sctp_subtype_t type
,
93 sctp_cmd_seq_t
*commands
);
94 static sctp_disposition_t
sctp_sf_tabort_8_4_8(const struct sctp_endpoint
*ep
,
95 const struct sctp_association
*asoc
,
96 const sctp_subtype_t type
,
98 sctp_cmd_seq_t
*commands
);
99 static struct sctp_sackhdr
*sctp_sm_pull_sack(struct sctp_chunk
*chunk
);
101 static sctp_disposition_t
sctp_stop_t1_and_abort(sctp_cmd_seq_t
*commands
,
102 __be16 error
, int sk_err
,
103 const struct sctp_association
*asoc
,
104 struct sctp_transport
*transport
);
106 static sctp_disposition_t
sctp_sf_abort_violation(
107 const struct sctp_endpoint
*ep
,
108 const struct sctp_association
*asoc
,
110 sctp_cmd_seq_t
*commands
,
112 const size_t paylen
);
114 static sctp_disposition_t
sctp_sf_violation_chunklen(
115 const struct sctp_endpoint
*ep
,
116 const struct sctp_association
*asoc
,
117 const sctp_subtype_t type
,
119 sctp_cmd_seq_t
*commands
);
121 static sctp_disposition_t
sctp_sf_violation_paramlen(
122 const struct sctp_endpoint
*ep
,
123 const struct sctp_association
*asoc
,
124 const sctp_subtype_t type
,
125 void *arg
, void *ext
,
126 sctp_cmd_seq_t
*commands
);
128 static sctp_disposition_t
sctp_sf_violation_ctsn(
129 const struct sctp_endpoint
*ep
,
130 const struct sctp_association
*asoc
,
131 const sctp_subtype_t type
,
133 sctp_cmd_seq_t
*commands
);
135 static sctp_disposition_t
sctp_sf_violation_chunk(
136 const struct sctp_endpoint
*ep
,
137 const struct sctp_association
*asoc
,
138 const sctp_subtype_t type
,
140 sctp_cmd_seq_t
*commands
);
142 static sctp_ierror_t
sctp_sf_authenticate(const struct sctp_endpoint
*ep
,
143 const struct sctp_association
*asoc
,
144 const sctp_subtype_t type
,
145 struct sctp_chunk
*chunk
);
147 static sctp_disposition_t
__sctp_sf_do_9_1_abort(const struct sctp_endpoint
*ep
,
148 const struct sctp_association
*asoc
,
149 const sctp_subtype_t type
,
151 sctp_cmd_seq_t
*commands
);
153 /* Small helper function that checks if the chunk length
154 * is of the appropriate length. The 'required_length' argument
155 * is set to be the size of a specific chunk we are testing.
156 * Return Values: 1 = Valid length
161 sctp_chunk_length_valid(struct sctp_chunk
*chunk
,
162 __u16 required_length
)
164 __u16 chunk_length
= ntohs(chunk
->chunk_hdr
->length
);
166 if (unlikely(chunk_length
< required_length
))
172 /**********************************************************
173 * These are the state functions for handling chunk events.
174 **********************************************************/
177 * Process the final SHUTDOWN COMPLETE.
179 * Section: 4 (C) (diagram), 9.2
180 * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify
181 * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be
182 * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint
183 * should stop the T2-shutdown timer and remove all knowledge of the
184 * association (and thus the association enters the CLOSED state).
186 * Verification Tag: 8.5.1(C), sctpimpguide 2.41.
187 * C) Rules for packet carrying SHUTDOWN COMPLETE:
189 * - The receiver of a SHUTDOWN COMPLETE shall accept the packet
190 * if the Verification Tag field of the packet matches its own tag and
191 * the T bit is not set
193 * it is set to its peer's tag and the T bit is set in the Chunk
195 * Otherwise, the receiver MUST silently discard the packet
196 * and take no further action. An endpoint MUST ignore the
197 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
200 * (endpoint, asoc, chunk)
203 * (asoc, reply_msg, msg_up, timers, counters)
205 * The return value is the disposition of the chunk.
207 sctp_disposition_t
sctp_sf_do_4_C(const struct sctp_endpoint
*ep
,
208 const struct sctp_association
*asoc
,
209 const sctp_subtype_t type
,
211 sctp_cmd_seq_t
*commands
)
213 struct sctp_chunk
*chunk
= arg
;
214 struct sctp_ulpevent
*ev
;
216 if (!sctp_vtag_verify_either(chunk
, asoc
))
217 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
219 /* RFC 2960 6.10 Bundling
221 * An endpoint MUST NOT bundle INIT, INIT ACK or
222 * SHUTDOWN COMPLETE with any other chunks.
224 if (!chunk
->singleton
)
225 return sctp_sf_violation_chunk(ep
, asoc
, type
, arg
, commands
);
227 /* Make sure that the SHUTDOWN_COMPLETE chunk has a valid length. */
228 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
229 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
232 /* RFC 2960 10.2 SCTP-to-ULP
234 * H) SHUTDOWN COMPLETE notification
236 * When SCTP completes the shutdown procedures (section 9.2) this
237 * notification is passed to the upper layer.
239 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_SHUTDOWN_COMP
,
240 0, 0, 0, NULL
, GFP_ATOMIC
);
242 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
245 /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint
246 * will verify that it is in SHUTDOWN-ACK-SENT state, if it is
247 * not the chunk should be discarded. If the endpoint is in
248 * the SHUTDOWN-ACK-SENT state the endpoint should stop the
249 * T2-shutdown timer and remove all knowledge of the
250 * association (and thus the association enters the CLOSED
253 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
254 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
256 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
257 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
259 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
260 SCTP_STATE(SCTP_STATE_CLOSED
));
262 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS
);
263 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
265 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
267 return SCTP_DISPOSITION_DELETE_TCB
;
271 * Respond to a normal INIT chunk.
272 * We are the side that is being asked for an association.
274 * Section: 5.1 Normal Establishment of an Association, B
275 * B) "Z" shall respond immediately with an INIT ACK chunk. The
276 * destination IP address of the INIT ACK MUST be set to the source
277 * IP address of the INIT to which this INIT ACK is responding. In
278 * the response, besides filling in other parameters, "Z" must set the
279 * Verification Tag field to Tag_A, and also provide its own
280 * Verification Tag (Tag_Z) in the Initiate Tag field.
282 * Verification Tag: Must be 0.
285 * (endpoint, asoc, chunk)
288 * (asoc, reply_msg, msg_up, timers, counters)
290 * The return value is the disposition of the chunk.
292 sctp_disposition_t
sctp_sf_do_5_1B_init(const struct sctp_endpoint
*ep
,
293 const struct sctp_association
*asoc
,
294 const sctp_subtype_t type
,
296 sctp_cmd_seq_t
*commands
)
298 struct sctp_chunk
*chunk
= arg
;
299 struct sctp_chunk
*repl
;
300 struct sctp_association
*new_asoc
;
301 struct sctp_chunk
*err_chunk
;
302 struct sctp_packet
*packet
;
303 sctp_unrecognized_param_t
*unk_param
;
307 * An endpoint MUST NOT bundle INIT, INIT ACK or
308 * SHUTDOWN COMPLETE with any other chunks.
311 * Furthermore, we require that the receiver of an INIT chunk MUST
312 * enforce these rules by silently discarding an arriving packet
313 * with an INIT chunk that is bundled with other chunks.
315 if (!chunk
->singleton
)
316 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
318 /* If the packet is an OOTB packet which is temporarily on the
319 * control endpoint, respond with an ABORT.
321 if (ep
== sctp_sk((sctp_get_ctl_sock()))->ep
) {
322 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES
);
323 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
, commands
);
326 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
329 if (chunk
->sctp_hdr
->vtag
!= 0)
330 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
, commands
);
332 /* Make sure that the INIT chunk has a valid length.
333 * Normally, this would cause an ABORT with a Protocol Violation
334 * error, but since we don't have an association, we'll
335 * just discard the packet.
337 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_init_chunk_t
)))
338 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
340 /* If the INIT is coming toward a closing socket, we'll send back
341 * and ABORT. Essentially, this catches the race of INIT being
342 * backloged to the socket at the same time as the user isses close().
343 * Since the socket and all its associations are going away, we
344 * can treat this OOTB
346 if (sctp_sstate(ep
->base
.sk
, CLOSING
))
347 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
, commands
);
349 /* Verify the INIT chunk before processing it. */
351 if (!sctp_verify_init(asoc
, chunk
->chunk_hdr
->type
,
352 (sctp_init_chunk_t
*)chunk
->chunk_hdr
, chunk
,
354 /* This chunk contains fatal error. It is to be discarded.
355 * Send an ABORT, with causes if there is any.
358 packet
= sctp_abort_pkt_new(ep
, asoc
, arg
,
359 (__u8
*)(err_chunk
->chunk_hdr
) +
360 sizeof(sctp_chunkhdr_t
),
361 ntohs(err_chunk
->chunk_hdr
->length
) -
362 sizeof(sctp_chunkhdr_t
));
364 sctp_chunk_free(err_chunk
);
367 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
368 SCTP_PACKET(packet
));
369 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
370 return SCTP_DISPOSITION_CONSUME
;
372 return SCTP_DISPOSITION_NOMEM
;
375 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
,
380 /* Grab the INIT header. */
381 chunk
->subh
.init_hdr
= (sctp_inithdr_t
*)chunk
->skb
->data
;
383 /* Tag the variable length parameters. */
384 chunk
->param_hdr
.v
= skb_pull(chunk
->skb
, sizeof(sctp_inithdr_t
));
386 new_asoc
= sctp_make_temp_asoc(ep
, chunk
, GFP_ATOMIC
);
390 if (sctp_assoc_set_bind_addr_from_ep(new_asoc
,
391 sctp_scope(sctp_source(chunk
)),
395 /* The call, sctp_process_init(), can fail on memory allocation. */
396 if (!sctp_process_init(new_asoc
, chunk
, sctp_source(chunk
),
397 (sctp_init_chunk_t
*)chunk
->chunk_hdr
,
401 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
403 /* If there are errors need to be reported for unknown parameters,
404 * make sure to reserve enough room in the INIT ACK for them.
408 len
= ntohs(err_chunk
->chunk_hdr
->length
) -
409 sizeof(sctp_chunkhdr_t
);
411 repl
= sctp_make_init_ack(new_asoc
, chunk
, GFP_ATOMIC
, len
);
415 /* If there are errors need to be reported for unknown parameters,
416 * include them in the outgoing INIT ACK as "Unrecognized parameter"
420 /* Get the "Unrecognized parameter" parameter(s) out of the
421 * ERROR chunk generated by sctp_verify_init(). Since the
422 * error cause code for "unknown parameter" and the
423 * "Unrecognized parameter" type is the same, we can
424 * construct the parameters in INIT ACK by copying the
427 unk_param
= (sctp_unrecognized_param_t
*)
428 ((__u8
*)(err_chunk
->chunk_hdr
) +
429 sizeof(sctp_chunkhdr_t
));
430 /* Replace the cause code with the "Unrecognized parameter"
433 sctp_addto_chunk(repl
, len
, unk_param
);
434 sctp_chunk_free(err_chunk
);
437 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(new_asoc
));
439 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
442 * Note: After sending out INIT ACK with the State Cookie parameter,
443 * "Z" MUST NOT allocate any resources, nor keep any states for the
444 * new association. Otherwise, "Z" will be vulnerable to resource
447 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
449 return SCTP_DISPOSITION_DELETE_TCB
;
452 sctp_association_free(new_asoc
);
455 sctp_chunk_free(err_chunk
);
456 return SCTP_DISPOSITION_NOMEM
;
460 * Respond to a normal INIT ACK chunk.
461 * We are the side that is initiating the association.
463 * Section: 5.1 Normal Establishment of an Association, C
464 * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init
465 * timer and leave COOKIE-WAIT state. "A" shall then send the State
466 * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start
467 * the T1-cookie timer, and enter the COOKIE-ECHOED state.
469 * Note: The COOKIE ECHO chunk can be bundled with any pending outbound
470 * DATA chunks, but it MUST be the first chunk in the packet and
471 * until the COOKIE ACK is returned the sender MUST NOT send any
472 * other packets to the peer.
474 * Verification Tag: 3.3.3
475 * If the value of the Initiate Tag in a received INIT ACK chunk is
476 * found to be 0, the receiver MUST treat it as an error and close the
477 * association by transmitting an ABORT.
480 * (endpoint, asoc, chunk)
483 * (asoc, reply_msg, msg_up, timers, counters)
485 * The return value is the disposition of the chunk.
487 sctp_disposition_t
sctp_sf_do_5_1C_ack(const struct sctp_endpoint
*ep
,
488 const struct sctp_association
*asoc
,
489 const sctp_subtype_t type
,
491 sctp_cmd_seq_t
*commands
)
493 struct sctp_chunk
*chunk
= arg
;
494 sctp_init_chunk_t
*initchunk
;
495 struct sctp_chunk
*err_chunk
;
496 struct sctp_packet
*packet
;
498 if (!sctp_vtag_verify(chunk
, asoc
))
499 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
502 * An endpoint MUST NOT bundle INIT, INIT ACK or
503 * SHUTDOWN COMPLETE with any other chunks.
505 if (!chunk
->singleton
)
506 return sctp_sf_violation_chunk(ep
, asoc
, type
, arg
, commands
);
508 /* Make sure that the INIT-ACK chunk has a valid length */
509 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_initack_chunk_t
)))
510 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
512 /* Grab the INIT header. */
513 chunk
->subh
.init_hdr
= (sctp_inithdr_t
*) chunk
->skb
->data
;
515 /* Verify the INIT chunk before processing it. */
517 if (!sctp_verify_init(asoc
, chunk
->chunk_hdr
->type
,
518 (sctp_init_chunk_t
*)chunk
->chunk_hdr
, chunk
,
521 sctp_error_t error
= SCTP_ERROR_NO_RESOURCE
;
523 /* This chunk contains fatal error. It is to be discarded.
524 * Send an ABORT, with causes. If there are no causes,
525 * then there wasn't enough memory. Just terminate
529 packet
= sctp_abort_pkt_new(ep
, asoc
, arg
,
530 (__u8
*)(err_chunk
->chunk_hdr
) +
531 sizeof(sctp_chunkhdr_t
),
532 ntohs(err_chunk
->chunk_hdr
->length
) -
533 sizeof(sctp_chunkhdr_t
));
535 sctp_chunk_free(err_chunk
);
538 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
539 SCTP_PACKET(packet
));
540 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
541 error
= SCTP_ERROR_INV_PARAM
;
545 /* SCTP-AUTH, Section 6.3:
546 * It should be noted that if the receiver wants to tear
547 * down an association in an authenticated way only, the
548 * handling of malformed packets should not result in
549 * tearing down the association.
551 * This means that if we only want to abort associations
552 * in an authenticated way (i.e AUTH+ABORT), then we
553 * can't destroy this association just because the packet
556 if (sctp_auth_recv_cid(SCTP_CID_ABORT
, asoc
))
557 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
559 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
560 return sctp_stop_t1_and_abort(commands
, error
, ECONNREFUSED
,
561 asoc
, chunk
->transport
);
564 /* Tag the variable length parameters. Note that we never
565 * convert the parameters in an INIT chunk.
567 chunk
->param_hdr
.v
= skb_pull(chunk
->skb
, sizeof(sctp_inithdr_t
));
569 initchunk
= (sctp_init_chunk_t
*) chunk
->chunk_hdr
;
571 sctp_add_cmd_sf(commands
, SCTP_CMD_PEER_INIT
,
572 SCTP_PEER_INIT(initchunk
));
574 /* Reset init error count upon receipt of INIT-ACK. */
575 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_COUNTER_RESET
, SCTP_NULL());
577 /* 5.1 C) "A" shall stop the T1-init timer and leave
578 * COOKIE-WAIT state. "A" shall then ... start the T1-cookie
579 * timer, and enter the COOKIE-ECHOED state.
581 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
582 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
583 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
584 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
585 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
586 SCTP_STATE(SCTP_STATE_COOKIE_ECHOED
));
588 /* SCTP-AUTH: genereate the assocition shared keys so that
589 * we can potentially signe the COOKIE-ECHO.
591 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_SHKEY
, SCTP_NULL());
593 /* 5.1 C) "A" shall then send the State Cookie received in the
594 * INIT ACK chunk in a COOKIE ECHO chunk, ...
596 /* If there is any errors to report, send the ERROR chunk generated
597 * for unknown parameters as well.
599 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_COOKIE_ECHO
,
600 SCTP_CHUNK(err_chunk
));
602 return SCTP_DISPOSITION_CONSUME
;
606 * Respond to a normal COOKIE ECHO chunk.
607 * We are the side that is being asked for an association.
609 * Section: 5.1 Normal Establishment of an Association, D
610 * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply
611 * with a COOKIE ACK chunk after building a TCB and moving to
612 * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with
613 * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK
614 * chunk MUST be the first chunk in the packet.
616 * IMPLEMENTATION NOTE: An implementation may choose to send the
617 * Communication Up notification to the SCTP user upon reception
618 * of a valid COOKIE ECHO chunk.
620 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
621 * D) Rules for packet carrying a COOKIE ECHO
623 * - When sending a COOKIE ECHO, the endpoint MUST use the value of the
624 * Initial Tag received in the INIT ACK.
626 * - The receiver of a COOKIE ECHO follows the procedures in Section 5.
629 * (endpoint, asoc, chunk)
632 * (asoc, reply_msg, msg_up, timers, counters)
634 * The return value is the disposition of the chunk.
636 sctp_disposition_t
sctp_sf_do_5_1D_ce(const struct sctp_endpoint
*ep
,
637 const struct sctp_association
*asoc
,
638 const sctp_subtype_t type
, void *arg
,
639 sctp_cmd_seq_t
*commands
)
641 struct sctp_chunk
*chunk
= arg
;
642 struct sctp_association
*new_asoc
;
643 sctp_init_chunk_t
*peer_init
;
644 struct sctp_chunk
*repl
;
645 struct sctp_ulpevent
*ev
, *ai_ev
= NULL
;
647 struct sctp_chunk
*err_chk_p
;
650 /* If the packet is an OOTB packet which is temporarily on the
651 * control endpoint, respond with an ABORT.
653 if (ep
== sctp_sk((sctp_get_ctl_sock()))->ep
) {
654 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES
);
655 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
, commands
);
658 /* Make sure that the COOKIE_ECHO chunk has a valid length.
659 * In this case, we check that we have enough for at least a
660 * chunk header. More detailed verification is done
661 * in sctp_unpack_cookie().
663 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
664 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
666 /* If the endpoint is not listening or if the number of associations
667 * on the TCP-style socket exceed the max backlog, respond with an
671 if (!sctp_sstate(sk
, LISTENING
) ||
672 (sctp_style(sk
, TCP
) && sk_acceptq_is_full(sk
)))
673 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
, commands
);
675 /* "Decode" the chunk. We have no optional parameters so we
678 chunk
->subh
.cookie_hdr
=
679 (struct sctp_signed_cookie
*)chunk
->skb
->data
;
680 if (!pskb_pull(chunk
->skb
, ntohs(chunk
->chunk_hdr
->length
) -
681 sizeof(sctp_chunkhdr_t
)))
684 /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
685 * "Z" will reply with a COOKIE ACK chunk after building a TCB
686 * and moving to the ESTABLISHED state.
688 new_asoc
= sctp_unpack_cookie(ep
, asoc
, chunk
, GFP_ATOMIC
, &error
,
692 * If the re-build failed, what is the proper error path
695 * [We should abort the association. --piggy]
698 /* FIXME: Several errors are possible. A bad cookie should
699 * be silently discarded, but think about logging it too.
702 case -SCTP_IERROR_NOMEM
:
705 case -SCTP_IERROR_STALE_COOKIE
:
706 sctp_send_stale_cookie_err(ep
, asoc
, chunk
, commands
,
708 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
710 case -SCTP_IERROR_BAD_SIG
:
712 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
717 /* Delay state machine commands until later.
719 * Re-build the bind address for the association is done in
720 * the sctp_unpack_cookie() already.
722 /* This is a brand-new association, so these are not yet side
723 * effects--it is safe to run them here.
725 peer_init
= &chunk
->subh
.cookie_hdr
->c
.peer_init
[0];
727 if (!sctp_process_init(new_asoc
, chunk
,
728 &chunk
->subh
.cookie_hdr
->c
.peer_addr
,
729 peer_init
, GFP_ATOMIC
))
732 /* SCTP-AUTH: Now that we've populate required fields in
733 * sctp_process_init, set up the assocaition shared keys as
734 * necessary so that we can potentially authenticate the ACK
736 error
= sctp_auth_asoc_init_active_key(new_asoc
, GFP_ATOMIC
);
740 /* SCTP-AUTH: auth_chunk pointer is only set when the cookie-echo
741 * is supposed to be authenticated and we have to do delayed
742 * authentication. We've just recreated the association using
743 * the information in the cookie and now it's much easier to
744 * do the authentication.
746 if (chunk
->auth_chunk
) {
747 struct sctp_chunk auth
;
750 /* set-up our fake chunk so that we can process it */
751 auth
.skb
= chunk
->auth_chunk
;
752 auth
.asoc
= chunk
->asoc
;
753 auth
.sctp_hdr
= chunk
->sctp_hdr
;
754 auth
.chunk_hdr
= (sctp_chunkhdr_t
*)skb_push(chunk
->auth_chunk
,
755 sizeof(sctp_chunkhdr_t
));
756 skb_pull(chunk
->auth_chunk
, sizeof(sctp_chunkhdr_t
));
757 auth
.transport
= chunk
->transport
;
759 ret
= sctp_sf_authenticate(ep
, new_asoc
, type
, &auth
);
761 /* We can now safely free the auth_chunk clone */
762 kfree_skb(chunk
->auth_chunk
);
764 if (ret
!= SCTP_IERROR_NO_ERROR
) {
765 sctp_association_free(new_asoc
);
766 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
770 repl
= sctp_make_cookie_ack(new_asoc
, chunk
);
774 /* RFC 2960 5.1 Normal Establishment of an Association
776 * D) IMPLEMENTATION NOTE: An implementation may choose to
777 * send the Communication Up notification to the SCTP user
778 * upon reception of a valid COOKIE ECHO chunk.
780 ev
= sctp_ulpevent_make_assoc_change(new_asoc
, 0, SCTP_COMM_UP
, 0,
781 new_asoc
->c
.sinit_num_ostreams
,
782 new_asoc
->c
.sinit_max_instreams
,
787 /* Sockets API Draft Section 5.3.1.6
788 * When a peer sends a Adaptation Layer Indication parameter , SCTP
789 * delivers this notification to inform the application that of the
790 * peers requested adaptation layer.
792 if (new_asoc
->peer
.adaptation_ind
) {
793 ai_ev
= sctp_ulpevent_make_adaptation_indication(new_asoc
,
799 /* Add all the state machine commands now since we've created
800 * everything. This way we don't introduce memory corruptions
801 * during side-effect processing and correclty count established
804 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(new_asoc
));
805 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
806 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
807 SCTP_INC_STATS(SCTP_MIB_CURRESTAB
);
808 SCTP_INC_STATS(SCTP_MIB_PASSIVEESTABS
);
809 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_START
, SCTP_NULL());
811 if (new_asoc
->autoclose
)
812 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
813 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
815 /* This will send the COOKIE ACK */
816 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
818 /* Queue the ASSOC_CHANGE event */
819 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
821 /* Send up the Adaptation Layer Indication event */
823 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
824 SCTP_ULPEVENT(ai_ev
));
826 return SCTP_DISPOSITION_CONSUME
;
829 sctp_ulpevent_free(ev
);
831 sctp_chunk_free(repl
);
833 sctp_association_free(new_asoc
);
835 return SCTP_DISPOSITION_NOMEM
;
839 * Respond to a normal COOKIE ACK chunk.
840 * We are the side that is being asked for an association.
842 * RFC 2960 5.1 Normal Establishment of an Association
844 * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the
845 * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie
846 * timer. It may also notify its ULP about the successful
847 * establishment of the association with a Communication Up
848 * notification (see Section 10).
852 * (endpoint, asoc, chunk)
855 * (asoc, reply_msg, msg_up, timers, counters)
857 * The return value is the disposition of the chunk.
859 sctp_disposition_t
sctp_sf_do_5_1E_ca(const struct sctp_endpoint
*ep
,
860 const struct sctp_association
*asoc
,
861 const sctp_subtype_t type
, void *arg
,
862 sctp_cmd_seq_t
*commands
)
864 struct sctp_chunk
*chunk
= arg
;
865 struct sctp_ulpevent
*ev
;
867 if (!sctp_vtag_verify(chunk
, asoc
))
868 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
870 /* Verify that the chunk length for the COOKIE-ACK is OK.
871 * If we don't do this, any bundled chunks may be junked.
873 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
874 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
877 /* Reset init error count upon receipt of COOKIE-ACK,
878 * to avoid problems with the managemement of this
879 * counter in stale cookie situations when a transition back
880 * from the COOKIE-ECHOED state to the COOKIE-WAIT
881 * state is performed.
883 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_COUNTER_RESET
, SCTP_NULL());
885 /* RFC 2960 5.1 Normal Establishment of an Association
887 * E) Upon reception of the COOKIE ACK, endpoint "A" will move
888 * from the COOKIE-ECHOED state to the ESTABLISHED state,
889 * stopping the T1-cookie timer.
891 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
892 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
893 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
894 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
895 SCTP_INC_STATS(SCTP_MIB_CURRESTAB
);
896 SCTP_INC_STATS(SCTP_MIB_ACTIVEESTABS
);
897 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_START
, SCTP_NULL());
899 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
900 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
902 /* It may also notify its ULP about the successful
903 * establishment of the association with a Communication Up
904 * notification (see Section 10).
906 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_COMM_UP
,
907 0, asoc
->c
.sinit_num_ostreams
,
908 asoc
->c
.sinit_max_instreams
,
914 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
916 /* Sockets API Draft Section 5.3.1.6
917 * When a peer sends a Adaptation Layer Indication parameter , SCTP
918 * delivers this notification to inform the application that of the
919 * peers requested adaptation layer.
921 if (asoc
->peer
.adaptation_ind
) {
922 ev
= sctp_ulpevent_make_adaptation_indication(asoc
, GFP_ATOMIC
);
926 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
930 return SCTP_DISPOSITION_CONSUME
;
932 return SCTP_DISPOSITION_NOMEM
;
935 /* Generate and sendout a heartbeat packet. */
936 static sctp_disposition_t
sctp_sf_heartbeat(const struct sctp_endpoint
*ep
,
937 const struct sctp_association
*asoc
,
938 const sctp_subtype_t type
,
940 sctp_cmd_seq_t
*commands
)
942 struct sctp_transport
*transport
= (struct sctp_transport
*) arg
;
943 struct sctp_chunk
*reply
;
945 /* Send a heartbeat to our peer. */
946 reply
= sctp_make_heartbeat(asoc
, transport
);
948 return SCTP_DISPOSITION_NOMEM
;
950 /* Set rto_pending indicating that an RTT measurement
951 * is started with this heartbeat chunk.
953 sctp_add_cmd_sf(commands
, SCTP_CMD_RTO_PENDING
,
954 SCTP_TRANSPORT(transport
));
956 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
957 return SCTP_DISPOSITION_CONSUME
;
960 /* Generate a HEARTBEAT packet on the given transport. */
961 sctp_disposition_t
sctp_sf_sendbeat_8_3(const struct sctp_endpoint
*ep
,
962 const struct sctp_association
*asoc
,
963 const sctp_subtype_t type
,
965 sctp_cmd_seq_t
*commands
)
967 struct sctp_transport
*transport
= (struct sctp_transport
*) arg
;
969 if (asoc
->overall_error_count
>= asoc
->max_retrans
) {
970 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
971 SCTP_ERROR(ETIMEDOUT
));
972 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
973 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
974 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
975 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
976 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
977 return SCTP_DISPOSITION_DELETE_TCB
;
981 * The Sender-specific Heartbeat Info field should normally include
982 * information about the sender's current time when this HEARTBEAT
983 * chunk is sent and the destination transport address to which this
984 * HEARTBEAT is sent (see Section 8.3).
987 if (transport
->param_flags
& SPP_HB_ENABLE
) {
988 if (SCTP_DISPOSITION_NOMEM
==
989 sctp_sf_heartbeat(ep
, asoc
, type
, arg
,
991 return SCTP_DISPOSITION_NOMEM
;
993 /* Set transport error counter and association error counter
994 * when sending heartbeat.
996 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSPORT_HB_SENT
,
997 SCTP_TRANSPORT(transport
));
999 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSPORT_IDLE
,
1000 SCTP_TRANSPORT(transport
));
1001 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMER_UPDATE
,
1002 SCTP_TRANSPORT(transport
));
1004 return SCTP_DISPOSITION_CONSUME
;
1008 * Process an heartbeat request.
1010 * Section: 8.3 Path Heartbeat
1011 * The receiver of the HEARTBEAT should immediately respond with a
1012 * HEARTBEAT ACK that contains the Heartbeat Information field copied
1013 * from the received HEARTBEAT chunk.
1015 * Verification Tag: 8.5 Verification Tag [Normal verification]
1016 * When receiving an SCTP packet, the endpoint MUST ensure that the
1017 * value in the Verification Tag field of the received SCTP packet
1018 * matches its own Tag. If the received Verification Tag value does not
1019 * match the receiver's own tag value, the receiver shall silently
1020 * discard the packet and shall not process it any further except for
1021 * those cases listed in Section 8.5.1 below.
1024 * (endpoint, asoc, chunk)
1027 * (asoc, reply_msg, msg_up, timers, counters)
1029 * The return value is the disposition of the chunk.
1031 sctp_disposition_t
sctp_sf_beat_8_3(const struct sctp_endpoint
*ep
,
1032 const struct sctp_association
*asoc
,
1033 const sctp_subtype_t type
,
1035 sctp_cmd_seq_t
*commands
)
1037 struct sctp_chunk
*chunk
= arg
;
1038 struct sctp_chunk
*reply
;
1041 if (!sctp_vtag_verify(chunk
, asoc
))
1042 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
1044 /* Make sure that the HEARTBEAT chunk has a valid length. */
1045 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_heartbeat_chunk_t
)))
1046 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
1049 /* 8.3 The receiver of the HEARTBEAT should immediately
1050 * respond with a HEARTBEAT ACK that contains the Heartbeat
1051 * Information field copied from the received HEARTBEAT chunk.
1053 chunk
->subh
.hb_hdr
= (sctp_heartbeathdr_t
*) chunk
->skb
->data
;
1054 paylen
= ntohs(chunk
->chunk_hdr
->length
) - sizeof(sctp_chunkhdr_t
);
1055 if (!pskb_pull(chunk
->skb
, paylen
))
1058 reply
= sctp_make_heartbeat_ack(asoc
, chunk
,
1059 chunk
->subh
.hb_hdr
, paylen
);
1063 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
1064 return SCTP_DISPOSITION_CONSUME
;
1067 return SCTP_DISPOSITION_NOMEM
;
1071 * Process the returning HEARTBEAT ACK.
1073 * Section: 8.3 Path Heartbeat
1074 * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT
1075 * should clear the error counter of the destination transport
1076 * address to which the HEARTBEAT was sent, and mark the destination
1077 * transport address as active if it is not so marked. The endpoint may
1078 * optionally report to the upper layer when an inactive destination
1079 * address is marked as active due to the reception of the latest
1080 * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also
1081 * clear the association overall error count as well (as defined
1084 * The receiver of the HEARTBEAT ACK should also perform an RTT
1085 * measurement for that destination transport address using the time
1086 * value carried in the HEARTBEAT ACK chunk.
1088 * Verification Tag: 8.5 Verification Tag [Normal verification]
1091 * (endpoint, asoc, chunk)
1094 * (asoc, reply_msg, msg_up, timers, counters)
1096 * The return value is the disposition of the chunk.
1098 sctp_disposition_t
sctp_sf_backbeat_8_3(const struct sctp_endpoint
*ep
,
1099 const struct sctp_association
*asoc
,
1100 const sctp_subtype_t type
,
1102 sctp_cmd_seq_t
*commands
)
1104 struct sctp_chunk
*chunk
= arg
;
1105 union sctp_addr from_addr
;
1106 struct sctp_transport
*link
;
1107 sctp_sender_hb_info_t
*hbinfo
;
1108 unsigned long max_interval
;
1110 if (!sctp_vtag_verify(chunk
, asoc
))
1111 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
1113 /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */
1114 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
) +
1115 sizeof(sctp_sender_hb_info_t
)))
1116 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
1119 hbinfo
= (sctp_sender_hb_info_t
*) chunk
->skb
->data
;
1120 /* Make sure that the length of the parameter is what we expect */
1121 if (ntohs(hbinfo
->param_hdr
.length
) !=
1122 sizeof(sctp_sender_hb_info_t
)) {
1123 return SCTP_DISPOSITION_DISCARD
;
1126 from_addr
= hbinfo
->daddr
;
1127 link
= sctp_assoc_lookup_paddr(asoc
, &from_addr
);
1129 /* This should never happen, but lets log it if so. */
1130 if (unlikely(!link
)) {
1131 if (from_addr
.sa
.sa_family
== AF_INET6
) {
1132 net_warn_ratelimited("%s association %p could not find address %pI6\n",
1135 &from_addr
.v6
.sin6_addr
);
1137 net_warn_ratelimited("%s association %p could not find address %pI4\n",
1140 &from_addr
.v4
.sin_addr
.s_addr
);
1142 return SCTP_DISPOSITION_DISCARD
;
1145 /* Validate the 64-bit random nonce. */
1146 if (hbinfo
->hb_nonce
!= link
->hb_nonce
)
1147 return SCTP_DISPOSITION_DISCARD
;
1149 max_interval
= link
->hbinterval
+ link
->rto
;
1151 /* Check if the timestamp looks valid. */
1152 if (time_after(hbinfo
->sent_at
, jiffies
) ||
1153 time_after(jiffies
, hbinfo
->sent_at
+ max_interval
)) {
1154 SCTP_DEBUG_PRINTK("%s: HEARTBEAT ACK with invalid timestamp "
1155 "received for transport: %p\n",
1157 return SCTP_DISPOSITION_DISCARD
;
1160 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of
1161 * the HEARTBEAT should clear the error counter of the
1162 * destination transport address to which the HEARTBEAT was
1163 * sent and mark the destination transport address as active if
1164 * it is not so marked.
1166 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSPORT_ON
, SCTP_TRANSPORT(link
));
1168 return SCTP_DISPOSITION_CONSUME
;
1171 /* Helper function to send out an abort for the restart
1174 static int sctp_sf_send_restart_abort(union sctp_addr
*ssa
,
1175 struct sctp_chunk
*init
,
1176 sctp_cmd_seq_t
*commands
)
1179 struct sctp_packet
*pkt
;
1180 union sctp_addr_param
*addrparm
;
1181 struct sctp_errhdr
*errhdr
;
1182 struct sctp_endpoint
*ep
;
1183 char buffer
[sizeof(struct sctp_errhdr
)+sizeof(union sctp_addr_param
)];
1184 struct sctp_af
*af
= sctp_get_af_specific(ssa
->v4
.sin_family
);
1186 /* Build the error on the stack. We are way to malloc crazy
1187 * throughout the code today.
1189 errhdr
= (struct sctp_errhdr
*)buffer
;
1190 addrparm
= (union sctp_addr_param
*)errhdr
->variable
;
1192 /* Copy into a parm format. */
1193 len
= af
->to_addr_param(ssa
, addrparm
);
1194 len
+= sizeof(sctp_errhdr_t
);
1196 errhdr
->cause
= SCTP_ERROR_RESTART
;
1197 errhdr
->length
= htons(len
);
1199 /* Assign to the control socket. */
1200 ep
= sctp_sk((sctp_get_ctl_sock()))->ep
;
1202 /* Association is NULL since this may be a restart attack and we
1203 * want to send back the attacker's vtag.
1205 pkt
= sctp_abort_pkt_new(ep
, NULL
, init
, errhdr
, len
);
1209 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
, SCTP_PACKET(pkt
));
1211 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
1213 /* Discard the rest of the inbound packet. */
1214 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
, SCTP_NULL());
1217 /* Even if there is no memory, treat as a failure so
1218 * the packet will get dropped.
1223 static bool list_has_sctp_addr(const struct list_head
*list
,
1224 union sctp_addr
*ipaddr
)
1226 struct sctp_transport
*addr
;
1228 list_for_each_entry(addr
, list
, transports
) {
1229 if (sctp_cmp_addr_exact(ipaddr
, &addr
->ipaddr
))
1235 /* A restart is occurring, check to make sure no new addresses
1236 * are being added as we may be under a takeover attack.
1238 static int sctp_sf_check_restart_addrs(const struct sctp_association
*new_asoc
,
1239 const struct sctp_association
*asoc
,
1240 struct sctp_chunk
*init
,
1241 sctp_cmd_seq_t
*commands
)
1243 struct sctp_transport
*new_addr
;
1246 /* Implementor's Guide - Section 5.2.2
1248 * Before responding the endpoint MUST check to see if the
1249 * unexpected INIT adds new addresses to the association. If new
1250 * addresses are added to the association, the endpoint MUST respond
1254 /* Search through all current addresses and make sure
1255 * we aren't adding any new ones.
1257 list_for_each_entry(new_addr
, &new_asoc
->peer
.transport_addr_list
,
1259 if (!list_has_sctp_addr(&asoc
->peer
.transport_addr_list
,
1260 &new_addr
->ipaddr
)) {
1261 sctp_sf_send_restart_abort(&new_addr
->ipaddr
, init
,
1268 /* Return success if all addresses were found. */
1272 /* Populate the verification/tie tags based on overlapping INIT
1275 * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state.
1277 static void sctp_tietags_populate(struct sctp_association
*new_asoc
,
1278 const struct sctp_association
*asoc
)
1280 switch (asoc
->state
) {
1282 /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */
1284 case SCTP_STATE_COOKIE_WAIT
:
1285 new_asoc
->c
.my_vtag
= asoc
->c
.my_vtag
;
1286 new_asoc
->c
.my_ttag
= asoc
->c
.my_vtag
;
1287 new_asoc
->c
.peer_ttag
= 0;
1290 case SCTP_STATE_COOKIE_ECHOED
:
1291 new_asoc
->c
.my_vtag
= asoc
->c
.my_vtag
;
1292 new_asoc
->c
.my_ttag
= asoc
->c
.my_vtag
;
1293 new_asoc
->c
.peer_ttag
= asoc
->c
.peer_vtag
;
1296 /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED,
1297 * COOKIE-WAIT and SHUTDOWN-ACK-SENT
1300 new_asoc
->c
.my_ttag
= asoc
->c
.my_vtag
;
1301 new_asoc
->c
.peer_ttag
= asoc
->c
.peer_vtag
;
1305 /* Other parameters for the endpoint SHOULD be copied from the
1306 * existing parameters of the association (e.g. number of
1307 * outbound streams) into the INIT ACK and cookie.
1309 new_asoc
->rwnd
= asoc
->rwnd
;
1310 new_asoc
->c
.sinit_num_ostreams
= asoc
->c
.sinit_num_ostreams
;
1311 new_asoc
->c
.sinit_max_instreams
= asoc
->c
.sinit_max_instreams
;
1312 new_asoc
->c
.initial_tsn
= asoc
->c
.initial_tsn
;
1316 * Compare vtag/tietag values to determine unexpected COOKIE-ECHO
1319 * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists.
1321 * Returns value representing action to be taken. These action values
1322 * correspond to Action/Description values in RFC 2960, Table 2.
1324 static char sctp_tietags_compare(struct sctp_association
*new_asoc
,
1325 const struct sctp_association
*asoc
)
1327 /* In this case, the peer may have restarted. */
1328 if ((asoc
->c
.my_vtag
!= new_asoc
->c
.my_vtag
) &&
1329 (asoc
->c
.peer_vtag
!= new_asoc
->c
.peer_vtag
) &&
1330 (asoc
->c
.my_vtag
== new_asoc
->c
.my_ttag
) &&
1331 (asoc
->c
.peer_vtag
== new_asoc
->c
.peer_ttag
))
1334 /* Collision case B. */
1335 if ((asoc
->c
.my_vtag
== new_asoc
->c
.my_vtag
) &&
1336 ((asoc
->c
.peer_vtag
!= new_asoc
->c
.peer_vtag
) ||
1337 (0 == asoc
->c
.peer_vtag
))) {
1341 /* Collision case D. */
1342 if ((asoc
->c
.my_vtag
== new_asoc
->c
.my_vtag
) &&
1343 (asoc
->c
.peer_vtag
== new_asoc
->c
.peer_vtag
))
1346 /* Collision case C. */
1347 if ((asoc
->c
.my_vtag
!= new_asoc
->c
.my_vtag
) &&
1348 (asoc
->c
.peer_vtag
== new_asoc
->c
.peer_vtag
) &&
1349 (0 == new_asoc
->c
.my_ttag
) &&
1350 (0 == new_asoc
->c
.peer_ttag
))
1353 /* No match to any of the special cases; discard this packet. */
1357 /* Common helper routine for both duplicate and simulataneous INIT
1360 static sctp_disposition_t
sctp_sf_do_unexpected_init(
1361 const struct sctp_endpoint
*ep
,
1362 const struct sctp_association
*asoc
,
1363 const sctp_subtype_t type
,
1364 void *arg
, sctp_cmd_seq_t
*commands
)
1366 sctp_disposition_t retval
;
1367 struct sctp_chunk
*chunk
= arg
;
1368 struct sctp_chunk
*repl
;
1369 struct sctp_association
*new_asoc
;
1370 struct sctp_chunk
*err_chunk
;
1371 struct sctp_packet
*packet
;
1372 sctp_unrecognized_param_t
*unk_param
;
1376 * An endpoint MUST NOT bundle INIT, INIT ACK or
1377 * SHUTDOWN COMPLETE with any other chunks.
1380 * Furthermore, we require that the receiver of an INIT chunk MUST
1381 * enforce these rules by silently discarding an arriving packet
1382 * with an INIT chunk that is bundled with other chunks.
1384 if (!chunk
->singleton
)
1385 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
1387 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
1390 if (chunk
->sctp_hdr
->vtag
!= 0)
1391 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
, commands
);
1393 /* Make sure that the INIT chunk has a valid length.
1394 * In this case, we generate a protocol violation since we have
1395 * an association established.
1397 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_init_chunk_t
)))
1398 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
1400 /* Grab the INIT header. */
1401 chunk
->subh
.init_hdr
= (sctp_inithdr_t
*) chunk
->skb
->data
;
1403 /* Tag the variable length parameters. */
1404 chunk
->param_hdr
.v
= skb_pull(chunk
->skb
, sizeof(sctp_inithdr_t
));
1406 /* Verify the INIT chunk before processing it. */
1408 if (!sctp_verify_init(asoc
, chunk
->chunk_hdr
->type
,
1409 (sctp_init_chunk_t
*)chunk
->chunk_hdr
, chunk
,
1411 /* This chunk contains fatal error. It is to be discarded.
1412 * Send an ABORT, with causes if there is any.
1415 packet
= sctp_abort_pkt_new(ep
, asoc
, arg
,
1416 (__u8
*)(err_chunk
->chunk_hdr
) +
1417 sizeof(sctp_chunkhdr_t
),
1418 ntohs(err_chunk
->chunk_hdr
->length
) -
1419 sizeof(sctp_chunkhdr_t
));
1422 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
1423 SCTP_PACKET(packet
));
1424 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
1425 retval
= SCTP_DISPOSITION_CONSUME
;
1427 retval
= SCTP_DISPOSITION_NOMEM
;
1431 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
,
1437 * Other parameters for the endpoint SHOULD be copied from the
1438 * existing parameters of the association (e.g. number of
1439 * outbound streams) into the INIT ACK and cookie.
1440 * FIXME: We are copying parameters from the endpoint not the
1443 new_asoc
= sctp_make_temp_asoc(ep
, chunk
, GFP_ATOMIC
);
1447 if (sctp_assoc_set_bind_addr_from_ep(new_asoc
,
1448 sctp_scope(sctp_source(chunk
)), GFP_ATOMIC
) < 0)
1451 /* In the outbound INIT ACK the endpoint MUST copy its current
1452 * Verification Tag and Peers Verification tag into a reserved
1453 * place (local tie-tag and per tie-tag) within the state cookie.
1455 if (!sctp_process_init(new_asoc
, chunk
, sctp_source(chunk
),
1456 (sctp_init_chunk_t
*)chunk
->chunk_hdr
,
1460 /* Make sure no new addresses are being added during the
1461 * restart. Do not do this check for COOKIE-WAIT state,
1462 * since there are no peer addresses to check against.
1463 * Upon return an ABORT will have been sent if needed.
1465 if (!sctp_state(asoc
, COOKIE_WAIT
)) {
1466 if (!sctp_sf_check_restart_addrs(new_asoc
, asoc
, chunk
,
1468 retval
= SCTP_DISPOSITION_CONSUME
;
1473 sctp_tietags_populate(new_asoc
, asoc
);
1475 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
1477 /* If there are errors need to be reported for unknown parameters,
1478 * make sure to reserve enough room in the INIT ACK for them.
1482 len
= ntohs(err_chunk
->chunk_hdr
->length
) -
1483 sizeof(sctp_chunkhdr_t
);
1486 repl
= sctp_make_init_ack(new_asoc
, chunk
, GFP_ATOMIC
, len
);
1490 /* If there are errors need to be reported for unknown parameters,
1491 * include them in the outgoing INIT ACK as "Unrecognized parameter"
1495 /* Get the "Unrecognized parameter" parameter(s) out of the
1496 * ERROR chunk generated by sctp_verify_init(). Since the
1497 * error cause code for "unknown parameter" and the
1498 * "Unrecognized parameter" type is the same, we can
1499 * construct the parameters in INIT ACK by copying the
1500 * ERROR causes over.
1502 unk_param
= (sctp_unrecognized_param_t
*)
1503 ((__u8
*)(err_chunk
->chunk_hdr
) +
1504 sizeof(sctp_chunkhdr_t
));
1505 /* Replace the cause code with the "Unrecognized parameter"
1508 sctp_addto_chunk(repl
, len
, unk_param
);
1511 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(new_asoc
));
1512 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1515 * Note: After sending out INIT ACK with the State Cookie parameter,
1516 * "Z" MUST NOT allocate any resources for this new association.
1517 * Otherwise, "Z" will be vulnerable to resource attacks.
1519 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
1520 retval
= SCTP_DISPOSITION_CONSUME
;
1525 retval
= SCTP_DISPOSITION_NOMEM
;
1528 sctp_association_free(new_asoc
);
1531 sctp_chunk_free(err_chunk
);
1536 * Handle simultaneous INIT.
1537 * This means we started an INIT and then we got an INIT request from
1540 * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B)
1541 * This usually indicates an initialization collision, i.e., each
1542 * endpoint is attempting, at about the same time, to establish an
1543 * association with the other endpoint.
1545 * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an
1546 * endpoint MUST respond with an INIT ACK using the same parameters it
1547 * sent in its original INIT chunk (including its Verification Tag,
1548 * unchanged). These original parameters are combined with those from the
1549 * newly received INIT chunk. The endpoint shall also generate a State
1550 * Cookie with the INIT ACK. The endpoint uses the parameters sent in its
1551 * INIT to calculate the State Cookie.
1553 * After that, the endpoint MUST NOT change its state, the T1-init
1554 * timer shall be left running and the corresponding TCB MUST NOT be
1555 * destroyed. The normal procedures for handling State Cookies when
1556 * a TCB exists will resolve the duplicate INITs to a single association.
1558 * For an endpoint that is in the COOKIE-ECHOED state it MUST populate
1559 * its Tie-Tags with the Tag information of itself and its peer (see
1560 * section 5.2.2 for a description of the Tie-Tags).
1562 * Verification Tag: Not explicit, but an INIT can not have a valid
1563 * verification tag, so we skip the check.
1566 * (endpoint, asoc, chunk)
1569 * (asoc, reply_msg, msg_up, timers, counters)
1571 * The return value is the disposition of the chunk.
1573 sctp_disposition_t
sctp_sf_do_5_2_1_siminit(const struct sctp_endpoint
*ep
,
1574 const struct sctp_association
*asoc
,
1575 const sctp_subtype_t type
,
1577 sctp_cmd_seq_t
*commands
)
1579 /* Call helper to do the real work for both simulataneous and
1580 * duplicate INIT chunk handling.
1582 return sctp_sf_do_unexpected_init(ep
, asoc
, type
, arg
, commands
);
1586 * Handle duplicated INIT messages. These are usually delayed
1589 * Section: 5.2.2 Unexpected INIT in States Other than CLOSED,
1590 * COOKIE-ECHOED and COOKIE-WAIT
1592 * Unless otherwise stated, upon reception of an unexpected INIT for
1593 * this association, the endpoint shall generate an INIT ACK with a
1594 * State Cookie. In the outbound INIT ACK the endpoint MUST copy its
1595 * current Verification Tag and peer's Verification Tag into a reserved
1596 * place within the state cookie. We shall refer to these locations as
1597 * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet
1598 * containing this INIT ACK MUST carry a Verification Tag value equal to
1599 * the Initiation Tag found in the unexpected INIT. And the INIT ACK
1600 * MUST contain a new Initiation Tag (randomly generated see Section
1601 * 5.3.1). Other parameters for the endpoint SHOULD be copied from the
1602 * existing parameters of the association (e.g. number of outbound
1603 * streams) into the INIT ACK and cookie.
1605 * After sending out the INIT ACK, the endpoint shall take no further
1606 * actions, i.e., the existing association, including its current state,
1607 * and the corresponding TCB MUST NOT be changed.
1609 * Note: Only when a TCB exists and the association is not in a COOKIE-
1610 * WAIT state are the Tie-Tags populated. For a normal association INIT
1611 * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be
1612 * set to 0 (indicating that no previous TCB existed). The INIT ACK and
1613 * State Cookie are populated as specified in section 5.2.1.
1615 * Verification Tag: Not specified, but an INIT has no way of knowing
1616 * what the verification tag could be, so we ignore it.
1619 * (endpoint, asoc, chunk)
1622 * (asoc, reply_msg, msg_up, timers, counters)
1624 * The return value is the disposition of the chunk.
1626 sctp_disposition_t
sctp_sf_do_5_2_2_dupinit(const struct sctp_endpoint
*ep
,
1627 const struct sctp_association
*asoc
,
1628 const sctp_subtype_t type
,
1630 sctp_cmd_seq_t
*commands
)
1632 /* Call helper to do the real work for both simulataneous and
1633 * duplicate INIT chunk handling.
1635 return sctp_sf_do_unexpected_init(ep
, asoc
, type
, arg
, commands
);
1640 * Unexpected INIT-ACK handler.
1643 * If an INIT ACK received by an endpoint in any state other than the
1644 * COOKIE-WAIT state, the endpoint should discard the INIT ACK chunk.
1645 * An unexpected INIT ACK usually indicates the processing of an old or
1646 * duplicated INIT chunk.
1648 sctp_disposition_t
sctp_sf_do_5_2_3_initack(const struct sctp_endpoint
*ep
,
1649 const struct sctp_association
*asoc
,
1650 const sctp_subtype_t type
,
1651 void *arg
, sctp_cmd_seq_t
*commands
)
1653 /* Per the above section, we'll discard the chunk if we have an
1654 * endpoint. If this is an OOTB INIT-ACK, treat it as such.
1656 if (ep
== sctp_sk((sctp_get_ctl_sock()))->ep
)
1657 return sctp_sf_ootb(ep
, asoc
, type
, arg
, commands
);
1659 return sctp_sf_discard_chunk(ep
, asoc
, type
, arg
, commands
);
1662 /* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A')
1665 * A) In this case, the peer may have restarted.
1667 static sctp_disposition_t
sctp_sf_do_dupcook_a(const struct sctp_endpoint
*ep
,
1668 const struct sctp_association
*asoc
,
1669 struct sctp_chunk
*chunk
,
1670 sctp_cmd_seq_t
*commands
,
1671 struct sctp_association
*new_asoc
)
1673 sctp_init_chunk_t
*peer_init
;
1674 struct sctp_ulpevent
*ev
;
1675 struct sctp_chunk
*repl
;
1676 struct sctp_chunk
*err
;
1677 sctp_disposition_t disposition
;
1679 /* new_asoc is a brand-new association, so these are not yet
1680 * side effects--it is safe to run them here.
1682 peer_init
= &chunk
->subh
.cookie_hdr
->c
.peer_init
[0];
1684 if (!sctp_process_init(new_asoc
, chunk
, sctp_source(chunk
), peer_init
,
1688 /* Make sure no new addresses are being added during the
1689 * restart. Though this is a pretty complicated attack
1690 * since you'd have to get inside the cookie.
1692 if (!sctp_sf_check_restart_addrs(new_asoc
, asoc
, chunk
, commands
)) {
1693 return SCTP_DISPOSITION_CONSUME
;
1696 /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes
1697 * the peer has restarted (Action A), it MUST NOT setup a new
1698 * association but instead resend the SHUTDOWN ACK and send an ERROR
1699 * chunk with a "Cookie Received while Shutting Down" error cause to
1702 if (sctp_state(asoc
, SHUTDOWN_ACK_SENT
)) {
1703 disposition
= sctp_sf_do_9_2_reshutack(ep
, asoc
,
1704 SCTP_ST_CHUNK(chunk
->chunk_hdr
->type
),
1706 if (SCTP_DISPOSITION_NOMEM
== disposition
)
1709 err
= sctp_make_op_error(asoc
, chunk
,
1710 SCTP_ERROR_COOKIE_IN_SHUTDOWN
,
1713 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
1716 return SCTP_DISPOSITION_CONSUME
;
1719 /* For now, stop pending T3-rtx and SACK timers, fail any unsent/unacked
1720 * data. Consider the optional choice of resending of this data.
1722 sctp_add_cmd_sf(commands
, SCTP_CMD_T3_RTX_TIMERS_STOP
, SCTP_NULL());
1723 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
1724 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK
));
1725 sctp_add_cmd_sf(commands
, SCTP_CMD_PURGE_OUTQUEUE
, SCTP_NULL());
1727 /* Stop pending T4-rto timer, teardown ASCONF queue, ASCONF-ACK queue
1728 * and ASCONF-ACK cache.
1730 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
1731 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
1732 sctp_add_cmd_sf(commands
, SCTP_CMD_PURGE_ASCONF_QUEUE
, SCTP_NULL());
1734 repl
= sctp_make_cookie_ack(new_asoc
, chunk
);
1738 /* Report association restart to upper layer. */
1739 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_RESTART
, 0,
1740 new_asoc
->c
.sinit_num_ostreams
,
1741 new_asoc
->c
.sinit_max_instreams
,
1746 /* Update the content of current association. */
1747 sctp_add_cmd_sf(commands
, SCTP_CMD_UPDATE_ASSOC
, SCTP_ASOC(new_asoc
));
1748 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1749 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
1750 return SCTP_DISPOSITION_CONSUME
;
1753 sctp_chunk_free(repl
);
1755 return SCTP_DISPOSITION_NOMEM
;
1758 /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B')
1761 * B) In this case, both sides may be attempting to start an association
1762 * at about the same time but the peer endpoint started its INIT
1763 * after responding to the local endpoint's INIT
1765 /* This case represents an initialization collision. */
1766 static sctp_disposition_t
sctp_sf_do_dupcook_b(const struct sctp_endpoint
*ep
,
1767 const struct sctp_association
*asoc
,
1768 struct sctp_chunk
*chunk
,
1769 sctp_cmd_seq_t
*commands
,
1770 struct sctp_association
*new_asoc
)
1772 sctp_init_chunk_t
*peer_init
;
1773 struct sctp_chunk
*repl
;
1775 /* new_asoc is a brand-new association, so these are not yet
1776 * side effects--it is safe to run them here.
1778 peer_init
= &chunk
->subh
.cookie_hdr
->c
.peer_init
[0];
1779 if (!sctp_process_init(new_asoc
, chunk
, sctp_source(chunk
), peer_init
,
1783 /* Update the content of current association. */
1784 sctp_add_cmd_sf(commands
, SCTP_CMD_UPDATE_ASSOC
, SCTP_ASOC(new_asoc
));
1785 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
1786 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
1787 SCTP_INC_STATS(SCTP_MIB_CURRESTAB
);
1788 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_START
, SCTP_NULL());
1790 repl
= sctp_make_cookie_ack(new_asoc
, chunk
);
1794 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1796 /* RFC 2960 5.1 Normal Establishment of an Association
1798 * D) IMPLEMENTATION NOTE: An implementation may choose to
1799 * send the Communication Up notification to the SCTP user
1800 * upon reception of a valid COOKIE ECHO chunk.
1802 * Sadly, this needs to be implemented as a side-effect, because
1803 * we are not guaranteed to have set the association id of the real
1804 * association and so these notifications need to be delayed until
1805 * the association id is allocated.
1808 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_CHANGE
, SCTP_U8(SCTP_COMM_UP
));
1810 /* Sockets API Draft Section 5.3.1.6
1811 * When a peer sends a Adaptation Layer Indication parameter , SCTP
1812 * delivers this notification to inform the application that of the
1813 * peers requested adaptation layer.
1815 * This also needs to be done as a side effect for the same reason as
1818 if (asoc
->peer
.adaptation_ind
)
1819 sctp_add_cmd_sf(commands
, SCTP_CMD_ADAPTATION_IND
, SCTP_NULL());
1821 return SCTP_DISPOSITION_CONSUME
;
1824 return SCTP_DISPOSITION_NOMEM
;
1827 /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C')
1830 * C) In this case, the local endpoint's cookie has arrived late.
1831 * Before it arrived, the local endpoint sent an INIT and received an
1832 * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag
1833 * but a new tag of its own.
1835 /* This case represents an initialization collision. */
1836 static sctp_disposition_t
sctp_sf_do_dupcook_c(const struct sctp_endpoint
*ep
,
1837 const struct sctp_association
*asoc
,
1838 struct sctp_chunk
*chunk
,
1839 sctp_cmd_seq_t
*commands
,
1840 struct sctp_association
*new_asoc
)
1842 /* The cookie should be silently discarded.
1843 * The endpoint SHOULD NOT change states and should leave
1844 * any timers running.
1846 return SCTP_DISPOSITION_DISCARD
;
1849 /* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D')
1853 * D) When both local and remote tags match the endpoint should always
1854 * enter the ESTABLISHED state, if it has not already done so.
1856 /* This case represents an initialization collision. */
1857 static sctp_disposition_t
sctp_sf_do_dupcook_d(const struct sctp_endpoint
*ep
,
1858 const struct sctp_association
*asoc
,
1859 struct sctp_chunk
*chunk
,
1860 sctp_cmd_seq_t
*commands
,
1861 struct sctp_association
*new_asoc
)
1863 struct sctp_ulpevent
*ev
= NULL
, *ai_ev
= NULL
;
1864 struct sctp_chunk
*repl
;
1866 /* Clarification from Implementor's Guide:
1867 * D) When both local and remote tags match the endpoint should
1868 * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state.
1869 * It should stop any cookie timer that may be running and send
1873 /* Don't accidentally move back into established state. */
1874 if (asoc
->state
< SCTP_STATE_ESTABLISHED
) {
1875 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
1876 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
1877 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
1878 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
1879 SCTP_INC_STATS(SCTP_MIB_CURRESTAB
);
1880 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_START
,
1883 /* RFC 2960 5.1 Normal Establishment of an Association
1885 * D) IMPLEMENTATION NOTE: An implementation may choose
1886 * to send the Communication Up notification to the
1887 * SCTP user upon reception of a valid COOKIE
1890 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0,
1892 asoc
->c
.sinit_num_ostreams
,
1893 asoc
->c
.sinit_max_instreams
,
1898 /* Sockets API Draft Section 5.3.1.6
1899 * When a peer sends a Adaptation Layer Indication parameter,
1900 * SCTP delivers this notification to inform the application
1901 * that of the peers requested adaptation layer.
1903 if (asoc
->peer
.adaptation_ind
) {
1904 ai_ev
= sctp_ulpevent_make_adaptation_indication(asoc
,
1912 repl
= sctp_make_cookie_ack(new_asoc
, chunk
);
1916 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1919 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
1922 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
1923 SCTP_ULPEVENT(ai_ev
));
1925 return SCTP_DISPOSITION_CONSUME
;
1929 sctp_ulpevent_free(ai_ev
);
1931 sctp_ulpevent_free(ev
);
1932 return SCTP_DISPOSITION_NOMEM
;
1936 * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying
1937 * chunk was retransmitted and then delayed in the network.
1939 * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists
1941 * Verification Tag: None. Do cookie validation.
1944 * (endpoint, asoc, chunk)
1947 * (asoc, reply_msg, msg_up, timers, counters)
1949 * The return value is the disposition of the chunk.
1951 sctp_disposition_t
sctp_sf_do_5_2_4_dupcook(const struct sctp_endpoint
*ep
,
1952 const struct sctp_association
*asoc
,
1953 const sctp_subtype_t type
,
1955 sctp_cmd_seq_t
*commands
)
1957 sctp_disposition_t retval
;
1958 struct sctp_chunk
*chunk
= arg
;
1959 struct sctp_association
*new_asoc
;
1962 struct sctp_chunk
*err_chk_p
;
1964 /* Make sure that the chunk has a valid length from the protocol
1965 * perspective. In this case check to make sure we have at least
1966 * enough for the chunk header. Cookie length verification is
1969 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
1970 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
1973 /* "Decode" the chunk. We have no optional parameters so we
1974 * are in good shape.
1976 chunk
->subh
.cookie_hdr
= (struct sctp_signed_cookie
*)chunk
->skb
->data
;
1977 if (!pskb_pull(chunk
->skb
, ntohs(chunk
->chunk_hdr
->length
) -
1978 sizeof(sctp_chunkhdr_t
)))
1981 /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
1982 * of a duplicate COOKIE ECHO match the Verification Tags of the
1983 * current association, consider the State Cookie valid even if
1984 * the lifespan is exceeded.
1986 new_asoc
= sctp_unpack_cookie(ep
, asoc
, chunk
, GFP_ATOMIC
, &error
,
1990 * If the re-build failed, what is the proper error path
1993 * [We should abort the association. --piggy]
1996 /* FIXME: Several errors are possible. A bad cookie should
1997 * be silently discarded, but think about logging it too.
2000 case -SCTP_IERROR_NOMEM
:
2003 case -SCTP_IERROR_STALE_COOKIE
:
2004 sctp_send_stale_cookie_err(ep
, asoc
, chunk
, commands
,
2006 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2007 case -SCTP_IERROR_BAD_SIG
:
2009 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2013 /* Compare the tie_tag in cookie with the verification tag of
2014 * current association.
2016 action
= sctp_tietags_compare(new_asoc
, asoc
);
2019 case 'A': /* Association restart. */
2020 retval
= sctp_sf_do_dupcook_a(ep
, asoc
, chunk
, commands
,
2024 case 'B': /* Collision case B. */
2025 retval
= sctp_sf_do_dupcook_b(ep
, asoc
, chunk
, commands
,
2029 case 'C': /* Collision case C. */
2030 retval
= sctp_sf_do_dupcook_c(ep
, asoc
, chunk
, commands
,
2034 case 'D': /* Collision case D. */
2035 retval
= sctp_sf_do_dupcook_d(ep
, asoc
, chunk
, commands
,
2039 default: /* Discard packet for all others. */
2040 retval
= sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2044 /* Delete the tempory new association. */
2045 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(new_asoc
));
2046 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
2048 /* Restore association pointer to provide SCTP command interpeter
2049 * with a valid context in case it needs to manipulate
2051 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_ASOC
,
2052 SCTP_ASOC((struct sctp_association
*)asoc
));
2057 return SCTP_DISPOSITION_NOMEM
;
2061 * Process an ABORT. (SHUTDOWN-PENDING state)
2063 * See sctp_sf_do_9_1_abort().
2065 sctp_disposition_t
sctp_sf_shutdown_pending_abort(
2066 const struct sctp_endpoint
*ep
,
2067 const struct sctp_association
*asoc
,
2068 const sctp_subtype_t type
,
2070 sctp_cmd_seq_t
*commands
)
2072 struct sctp_chunk
*chunk
= arg
;
2074 if (!sctp_vtag_verify_either(chunk
, asoc
))
2075 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2077 /* Make sure that the ABORT chunk has a valid length.
2078 * Since this is an ABORT chunk, we have to discard it
2079 * because of the following text:
2080 * RFC 2960, Section 3.3.7
2081 * If an endpoint receives an ABORT with a format error or for an
2082 * association that doesn't exist, it MUST silently discard it.
2083 * Because the length is "invalid", we can't really discard just
2084 * as we do not know its true length. So, to be safe, discard the
2087 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_abort_chunk_t
)))
2088 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2090 /* ADD-IP: Special case for ABORT chunks
2091 * F4) One special consideration is that ABORT Chunks arriving
2092 * destined to the IP address being deleted MUST be
2093 * ignored (see Section 5.3.1 for further details).
2095 if (SCTP_ADDR_DEL
==
2096 sctp_bind_addr_state(&asoc
->base
.bind_addr
, &chunk
->dest
))
2097 return sctp_sf_discard_chunk(ep
, asoc
, type
, arg
, commands
);
2099 return __sctp_sf_do_9_1_abort(ep
, asoc
, type
, arg
, commands
);
2103 * Process an ABORT. (SHUTDOWN-SENT state)
2105 * See sctp_sf_do_9_1_abort().
2107 sctp_disposition_t
sctp_sf_shutdown_sent_abort(const struct sctp_endpoint
*ep
,
2108 const struct sctp_association
*asoc
,
2109 const sctp_subtype_t type
,
2111 sctp_cmd_seq_t
*commands
)
2113 struct sctp_chunk
*chunk
= arg
;
2115 if (!sctp_vtag_verify_either(chunk
, asoc
))
2116 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2118 /* Make sure that the ABORT chunk has a valid length.
2119 * Since this is an ABORT chunk, we have to discard it
2120 * because of the following text:
2121 * RFC 2960, Section 3.3.7
2122 * If an endpoint receives an ABORT with a format error or for an
2123 * association that doesn't exist, it MUST silently discard it.
2124 * Because the length is "invalid", we can't really discard just
2125 * as we do not know its true length. So, to be safe, discard the
2128 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_abort_chunk_t
)))
2129 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2131 /* ADD-IP: Special case for ABORT chunks
2132 * F4) One special consideration is that ABORT Chunks arriving
2133 * destined to the IP address being deleted MUST be
2134 * ignored (see Section 5.3.1 for further details).
2136 if (SCTP_ADDR_DEL
==
2137 sctp_bind_addr_state(&asoc
->base
.bind_addr
, &chunk
->dest
))
2138 return sctp_sf_discard_chunk(ep
, asoc
, type
, arg
, commands
);
2140 /* Stop the T2-shutdown timer. */
2141 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
2142 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
2144 /* Stop the T5-shutdown guard timer. */
2145 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
2146 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
2148 return __sctp_sf_do_9_1_abort(ep
, asoc
, type
, arg
, commands
);
2152 * Process an ABORT. (SHUTDOWN-ACK-SENT state)
2154 * See sctp_sf_do_9_1_abort().
2156 sctp_disposition_t
sctp_sf_shutdown_ack_sent_abort(
2157 const struct sctp_endpoint
*ep
,
2158 const struct sctp_association
*asoc
,
2159 const sctp_subtype_t type
,
2161 sctp_cmd_seq_t
*commands
)
2163 /* The same T2 timer, so we should be able to use
2164 * common function with the SHUTDOWN-SENT state.
2166 return sctp_sf_shutdown_sent_abort(ep
, asoc
, type
, arg
, commands
);
2170 * Handle an Error received in COOKIE_ECHOED state.
2172 * Only handle the error type of stale COOKIE Error, the other errors will
2176 * (endpoint, asoc, chunk)
2179 * (asoc, reply_msg, msg_up, timers, counters)
2181 * The return value is the disposition of the chunk.
2183 sctp_disposition_t
sctp_sf_cookie_echoed_err(const struct sctp_endpoint
*ep
,
2184 const struct sctp_association
*asoc
,
2185 const sctp_subtype_t type
,
2187 sctp_cmd_seq_t
*commands
)
2189 struct sctp_chunk
*chunk
= arg
;
2192 if (!sctp_vtag_verify(chunk
, asoc
))
2193 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2195 /* Make sure that the ERROR chunk has a valid length.
2196 * The parameter walking depends on this as well.
2198 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_operr_chunk_t
)))
2199 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2202 /* Process the error here */
2203 /* FUTURE FIXME: When PR-SCTP related and other optional
2204 * parms are emitted, this will have to change to handle multiple
2207 sctp_walk_errors(err
, chunk
->chunk_hdr
) {
2208 if (SCTP_ERROR_STALE_COOKIE
== err
->cause
)
2209 return sctp_sf_do_5_2_6_stale(ep
, asoc
, type
,
2213 /* It is possible to have malformed error causes, and that
2214 * will cause us to end the walk early. However, since
2215 * we are discarding the packet, there should be no adverse
2218 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2222 * Handle a Stale COOKIE Error
2224 * Section: 5.2.6 Handle Stale COOKIE Error
2225 * If the association is in the COOKIE-ECHOED state, the endpoint may elect
2226 * one of the following three alternatives.
2228 * 3) Send a new INIT chunk to the endpoint, adding a Cookie
2229 * Preservative parameter requesting an extension to the lifetime of
2230 * the State Cookie. When calculating the time extension, an
2231 * implementation SHOULD use the RTT information measured based on the
2232 * previous COOKIE ECHO / ERROR exchange, and should add no more
2233 * than 1 second beyond the measured RTT, due to long State Cookie
2234 * lifetimes making the endpoint more subject to a replay attack.
2236 * Verification Tag: Not explicit, but safe to ignore.
2239 * (endpoint, asoc, chunk)
2242 * (asoc, reply_msg, msg_up, timers, counters)
2244 * The return value is the disposition of the chunk.
2246 static sctp_disposition_t
sctp_sf_do_5_2_6_stale(const struct sctp_endpoint
*ep
,
2247 const struct sctp_association
*asoc
,
2248 const sctp_subtype_t type
,
2250 sctp_cmd_seq_t
*commands
)
2252 struct sctp_chunk
*chunk
= arg
;
2254 sctp_cookie_preserve_param_t bht
;
2256 struct sctp_chunk
*reply
;
2257 struct sctp_bind_addr
*bp
;
2258 int attempts
= asoc
->init_err_counter
+ 1;
2260 if (attempts
> asoc
->max_init_attempts
) {
2261 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
2262 SCTP_ERROR(ETIMEDOUT
));
2263 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
2264 SCTP_PERR(SCTP_ERROR_STALE_COOKIE
));
2265 return SCTP_DISPOSITION_DELETE_TCB
;
2268 err
= (sctp_errhdr_t
*)(chunk
->skb
->data
);
2270 /* When calculating the time extension, an implementation
2271 * SHOULD use the RTT information measured based on the
2272 * previous COOKIE ECHO / ERROR exchange, and should add no
2273 * more than 1 second beyond the measured RTT, due to long
2274 * State Cookie lifetimes making the endpoint more subject to
2276 * Measure of Staleness's unit is usec. (1/1000000 sec)
2277 * Suggested Cookie Life-span Increment's unit is msec.
2279 * In general, if you use the suggested cookie life, the value
2280 * found in the field of measure of staleness should be doubled
2281 * to give ample time to retransmit the new cookie and thus
2282 * yield a higher probability of success on the reattempt.
2284 stale
= ntohl(*(__be32
*)((u8
*)err
+ sizeof(sctp_errhdr_t
)));
2285 stale
= (stale
* 2) / 1000;
2287 bht
.param_hdr
.type
= SCTP_PARAM_COOKIE_PRESERVATIVE
;
2288 bht
.param_hdr
.length
= htons(sizeof(bht
));
2289 bht
.lifespan_increment
= htonl(stale
);
2291 /* Build that new INIT chunk. */
2292 bp
= (struct sctp_bind_addr
*) &asoc
->base
.bind_addr
;
2293 reply
= sctp_make_init(asoc
, bp
, GFP_ATOMIC
, sizeof(bht
));
2297 sctp_addto_chunk(reply
, sizeof(bht
), &bht
);
2299 /* Clear peer's init_tag cached in assoc as we are sending a new INIT */
2300 sctp_add_cmd_sf(commands
, SCTP_CMD_CLEAR_INIT_TAG
, SCTP_NULL());
2302 /* Stop pending T3-rtx and heartbeat timers */
2303 sctp_add_cmd_sf(commands
, SCTP_CMD_T3_RTX_TIMERS_STOP
, SCTP_NULL());
2304 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_STOP
, SCTP_NULL());
2306 /* Delete non-primary peer ip addresses since we are transitioning
2307 * back to the COOKIE-WAIT state
2309 sctp_add_cmd_sf(commands
, SCTP_CMD_DEL_NON_PRIMARY
, SCTP_NULL());
2311 /* If we've sent any data bundled with COOKIE-ECHO we will need to
2314 sctp_add_cmd_sf(commands
, SCTP_CMD_T1_RETRAN
,
2315 SCTP_TRANSPORT(asoc
->peer
.primary_path
));
2317 /* Cast away the const modifier, as we want to just
2318 * rerun it through as a sideffect.
2320 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_COUNTER_INC
, SCTP_NULL());
2322 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
2323 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
2324 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
2325 SCTP_STATE(SCTP_STATE_COOKIE_WAIT
));
2326 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
2327 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
2329 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
2331 return SCTP_DISPOSITION_CONSUME
;
2334 return SCTP_DISPOSITION_NOMEM
;
2341 * After checking the Verification Tag, the receiving endpoint shall
2342 * remove the association from its record, and shall report the
2343 * termination to its upper layer.
2345 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
2346 * B) Rules for packet carrying ABORT:
2348 * - The endpoint shall always fill in the Verification Tag field of the
2349 * outbound packet with the destination endpoint's tag value if it
2352 * - If the ABORT is sent in response to an OOTB packet, the endpoint
2353 * MUST follow the procedure described in Section 8.4.
2355 * - The receiver MUST accept the packet if the Verification Tag
2356 * matches either its own tag, OR the tag of its peer. Otherwise, the
2357 * receiver MUST silently discard the packet and take no further
2361 * (endpoint, asoc, chunk)
2364 * (asoc, reply_msg, msg_up, timers, counters)
2366 * The return value is the disposition of the chunk.
2368 sctp_disposition_t
sctp_sf_do_9_1_abort(const struct sctp_endpoint
*ep
,
2369 const struct sctp_association
*asoc
,
2370 const sctp_subtype_t type
,
2372 sctp_cmd_seq_t
*commands
)
2374 struct sctp_chunk
*chunk
= arg
;
2376 if (!sctp_vtag_verify_either(chunk
, asoc
))
2377 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2379 /* Make sure that the ABORT chunk has a valid length.
2380 * Since this is an ABORT chunk, we have to discard it
2381 * because of the following text:
2382 * RFC 2960, Section 3.3.7
2383 * If an endpoint receives an ABORT with a format error or for an
2384 * association that doesn't exist, it MUST silently discard it.
2385 * Because the length is "invalid", we can't really discard just
2386 * as we do not know its true length. So, to be safe, discard the
2389 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_abort_chunk_t
)))
2390 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2392 /* ADD-IP: Special case for ABORT chunks
2393 * F4) One special consideration is that ABORT Chunks arriving
2394 * destined to the IP address being deleted MUST be
2395 * ignored (see Section 5.3.1 for further details).
2397 if (SCTP_ADDR_DEL
==
2398 sctp_bind_addr_state(&asoc
->base
.bind_addr
, &chunk
->dest
))
2399 return sctp_sf_discard_chunk(ep
, asoc
, type
, arg
, commands
);
2401 return __sctp_sf_do_9_1_abort(ep
, asoc
, type
, arg
, commands
);
2404 static sctp_disposition_t
__sctp_sf_do_9_1_abort(const struct sctp_endpoint
*ep
,
2405 const struct sctp_association
*asoc
,
2406 const sctp_subtype_t type
,
2408 sctp_cmd_seq_t
*commands
)
2410 struct sctp_chunk
*chunk
= arg
;
2412 __be16 error
= SCTP_ERROR_NO_ERROR
;
2414 /* See if we have an error cause code in the chunk. */
2415 len
= ntohs(chunk
->chunk_hdr
->length
);
2416 if (len
>= sizeof(struct sctp_chunkhdr
) + sizeof(struct sctp_errhdr
)) {
2419 sctp_walk_errors(err
, chunk
->chunk_hdr
);
2420 if ((void *)err
!= (void *)chunk
->chunk_end
)
2421 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2423 error
= ((sctp_errhdr_t
*)chunk
->skb
->data
)->cause
;
2426 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
, SCTP_ERROR(ECONNRESET
));
2427 /* ASSOC_FAILED will DELETE_TCB. */
2428 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
, SCTP_PERR(error
));
2429 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
2430 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
2432 return SCTP_DISPOSITION_ABORT
;
2436 * Process an ABORT. (COOKIE-WAIT state)
2438 * See sctp_sf_do_9_1_abort() above.
2440 sctp_disposition_t
sctp_sf_cookie_wait_abort(const struct sctp_endpoint
*ep
,
2441 const struct sctp_association
*asoc
,
2442 const sctp_subtype_t type
,
2444 sctp_cmd_seq_t
*commands
)
2446 struct sctp_chunk
*chunk
= arg
;
2448 __be16 error
= SCTP_ERROR_NO_ERROR
;
2450 if (!sctp_vtag_verify_either(chunk
, asoc
))
2451 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2453 /* Make sure that the ABORT chunk has a valid length.
2454 * Since this is an ABORT chunk, we have to discard it
2455 * because of the following text:
2456 * RFC 2960, Section 3.3.7
2457 * If an endpoint receives an ABORT with a format error or for an
2458 * association that doesn't exist, it MUST silently discard it.
2459 * Because the length is "invalid", we can't really discard just
2460 * as we do not know its true length. So, to be safe, discard the
2463 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_abort_chunk_t
)))
2464 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2466 /* See if we have an error cause code in the chunk. */
2467 len
= ntohs(chunk
->chunk_hdr
->length
);
2468 if (len
>= sizeof(struct sctp_chunkhdr
) + sizeof(struct sctp_errhdr
))
2469 error
= ((sctp_errhdr_t
*)chunk
->skb
->data
)->cause
;
2471 return sctp_stop_t1_and_abort(commands
, error
, ECONNREFUSED
, asoc
,
2476 * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state)
2478 sctp_disposition_t
sctp_sf_cookie_wait_icmp_abort(const struct sctp_endpoint
*ep
,
2479 const struct sctp_association
*asoc
,
2480 const sctp_subtype_t type
,
2482 sctp_cmd_seq_t
*commands
)
2484 return sctp_stop_t1_and_abort(commands
, SCTP_ERROR_NO_ERROR
,
2486 (struct sctp_transport
*)arg
);
2490 * Process an ABORT. (COOKIE-ECHOED state)
2492 sctp_disposition_t
sctp_sf_cookie_echoed_abort(const struct sctp_endpoint
*ep
,
2493 const struct sctp_association
*asoc
,
2494 const sctp_subtype_t type
,
2496 sctp_cmd_seq_t
*commands
)
2498 /* There is a single T1 timer, so we should be able to use
2499 * common function with the COOKIE-WAIT state.
2501 return sctp_sf_cookie_wait_abort(ep
, asoc
, type
, arg
, commands
);
2505 * Stop T1 timer and abort association with "INIT failed".
2507 * This is common code called by several sctp_sf_*_abort() functions above.
2509 static sctp_disposition_t
sctp_stop_t1_and_abort(sctp_cmd_seq_t
*commands
,
2510 __be16 error
, int sk_err
,
2511 const struct sctp_association
*asoc
,
2512 struct sctp_transport
*transport
)
2514 SCTP_DEBUG_PRINTK("ABORT received (INIT).\n");
2515 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
2516 SCTP_STATE(SCTP_STATE_CLOSED
));
2517 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
2518 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
2519 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
2520 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
, SCTP_ERROR(sk_err
));
2521 /* CMD_INIT_FAILED will DELETE_TCB. */
2522 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
2524 return SCTP_DISPOSITION_ABORT
;
2528 * sctp_sf_do_9_2_shut
2531 * Upon the reception of the SHUTDOWN, the peer endpoint shall
2532 * - enter the SHUTDOWN-RECEIVED state,
2534 * - stop accepting new data from its SCTP user
2536 * - verify, by checking the Cumulative TSN Ack field of the chunk,
2537 * that all its outstanding DATA chunks have been received by the
2540 * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT
2541 * send a SHUTDOWN in response to a ULP request. And should discard
2542 * subsequent SHUTDOWN chunks.
2544 * If there are still outstanding DATA chunks left, the SHUTDOWN
2545 * receiver shall continue to follow normal data transmission
2546 * procedures defined in Section 6 until all outstanding DATA chunks
2547 * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept
2548 * new data from its SCTP user.
2550 * Verification Tag: 8.5 Verification Tag [Normal verification]
2553 * (endpoint, asoc, chunk)
2556 * (asoc, reply_msg, msg_up, timers, counters)
2558 * The return value is the disposition of the chunk.
2560 sctp_disposition_t
sctp_sf_do_9_2_shutdown(const struct sctp_endpoint
*ep
,
2561 const struct sctp_association
*asoc
,
2562 const sctp_subtype_t type
,
2564 sctp_cmd_seq_t
*commands
)
2566 struct sctp_chunk
*chunk
= arg
;
2567 sctp_shutdownhdr_t
*sdh
;
2568 sctp_disposition_t disposition
;
2569 struct sctp_ulpevent
*ev
;
2572 if (!sctp_vtag_verify(chunk
, asoc
))
2573 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2575 /* Make sure that the SHUTDOWN chunk has a valid length. */
2576 if (!sctp_chunk_length_valid(chunk
,
2577 sizeof(struct sctp_shutdown_chunk_t
)))
2578 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2581 /* Convert the elaborate header. */
2582 sdh
= (sctp_shutdownhdr_t
*)chunk
->skb
->data
;
2583 skb_pull(chunk
->skb
, sizeof(sctp_shutdownhdr_t
));
2584 chunk
->subh
.shutdown_hdr
= sdh
;
2585 ctsn
= ntohl(sdh
->cum_tsn_ack
);
2587 if (TSN_lt(ctsn
, asoc
->ctsn_ack_point
)) {
2588 SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn
);
2589 SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc
->ctsn_ack_point
);
2590 return SCTP_DISPOSITION_DISCARD
;
2593 /* If Cumulative TSN Ack beyond the max tsn currently
2594 * send, terminating the association and respond to the
2595 * sender with an ABORT.
2597 if (!TSN_lt(ctsn
, asoc
->next_tsn
))
2598 return sctp_sf_violation_ctsn(ep
, asoc
, type
, arg
, commands
);
2600 /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT
2601 * When a peer sends a SHUTDOWN, SCTP delivers this notification to
2602 * inform the application that it should cease sending data.
2604 ev
= sctp_ulpevent_make_shutdown_event(asoc
, 0, GFP_ATOMIC
);
2606 disposition
= SCTP_DISPOSITION_NOMEM
;
2609 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
2611 /* Upon the reception of the SHUTDOWN, the peer endpoint shall
2612 * - enter the SHUTDOWN-RECEIVED state,
2613 * - stop accepting new data from its SCTP user
2615 * [This is implicit in the new state.]
2617 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
2618 SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED
));
2619 disposition
= SCTP_DISPOSITION_CONSUME
;
2621 if (sctp_outq_is_empty(&asoc
->outqueue
)) {
2622 disposition
= sctp_sf_do_9_2_shutdown_ack(ep
, asoc
, type
,
2626 if (SCTP_DISPOSITION_NOMEM
== disposition
)
2629 /* - verify, by checking the Cumulative TSN Ack field of the
2630 * chunk, that all its outstanding DATA chunks have been
2631 * received by the SHUTDOWN sender.
2633 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_CTSN
,
2634 SCTP_BE32(chunk
->subh
.shutdown_hdr
->cum_tsn_ack
));
2641 * sctp_sf_do_9_2_shut_ctsn
2643 * Once an endpoint has reached the SHUTDOWN-RECEIVED state,
2644 * it MUST NOT send a SHUTDOWN in response to a ULP request.
2645 * The Cumulative TSN Ack of the received SHUTDOWN chunk
2646 * MUST be processed.
2648 sctp_disposition_t
sctp_sf_do_9_2_shut_ctsn(const struct sctp_endpoint
*ep
,
2649 const struct sctp_association
*asoc
,
2650 const sctp_subtype_t type
,
2652 sctp_cmd_seq_t
*commands
)
2654 struct sctp_chunk
*chunk
= arg
;
2655 sctp_shutdownhdr_t
*sdh
;
2658 if (!sctp_vtag_verify(chunk
, asoc
))
2659 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2661 /* Make sure that the SHUTDOWN chunk has a valid length. */
2662 if (!sctp_chunk_length_valid(chunk
,
2663 sizeof(struct sctp_shutdown_chunk_t
)))
2664 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2667 sdh
= (sctp_shutdownhdr_t
*)chunk
->skb
->data
;
2668 ctsn
= ntohl(sdh
->cum_tsn_ack
);
2670 if (TSN_lt(ctsn
, asoc
->ctsn_ack_point
)) {
2671 SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn
);
2672 SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc
->ctsn_ack_point
);
2673 return SCTP_DISPOSITION_DISCARD
;
2676 /* If Cumulative TSN Ack beyond the max tsn currently
2677 * send, terminating the association and respond to the
2678 * sender with an ABORT.
2680 if (!TSN_lt(ctsn
, asoc
->next_tsn
))
2681 return sctp_sf_violation_ctsn(ep
, asoc
, type
, arg
, commands
);
2683 /* verify, by checking the Cumulative TSN Ack field of the
2684 * chunk, that all its outstanding DATA chunks have been
2685 * received by the SHUTDOWN sender.
2687 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_CTSN
,
2688 SCTP_BE32(sdh
->cum_tsn_ack
));
2690 return SCTP_DISPOSITION_CONSUME
;
2694 * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk
2695 * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination
2696 * transport addresses (either in the IP addresses or in the INIT chunk)
2697 * that belong to this association, it should discard the INIT chunk and
2698 * retransmit the SHUTDOWN ACK chunk.
2700 sctp_disposition_t
sctp_sf_do_9_2_reshutack(const struct sctp_endpoint
*ep
,
2701 const struct sctp_association
*asoc
,
2702 const sctp_subtype_t type
,
2704 sctp_cmd_seq_t
*commands
)
2706 struct sctp_chunk
*chunk
= (struct sctp_chunk
*) arg
;
2707 struct sctp_chunk
*reply
;
2709 /* Make sure that the chunk has a valid length */
2710 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
2711 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2714 /* Since we are not going to really process this INIT, there
2715 * is no point in verifying chunk boundries. Just generate
2718 reply
= sctp_make_shutdown_ack(asoc
, chunk
);
2722 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
2723 * the T2-SHUTDOWN timer.
2725 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T2
, SCTP_CHUNK(reply
));
2727 /* and restart the T2-shutdown timer. */
2728 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
2729 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
2731 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
2733 return SCTP_DISPOSITION_CONSUME
;
2735 return SCTP_DISPOSITION_NOMEM
;
2739 * sctp_sf_do_ecn_cwr
2741 * Section: Appendix A: Explicit Congestion Notification
2745 * RFC 2481 details a specific bit for a sender to send in the header of
2746 * its next outbound TCP segment to indicate to its peer that it has
2747 * reduced its congestion window. This is termed the CWR bit. For
2748 * SCTP the same indication is made by including the CWR chunk.
2749 * This chunk contains one data element, i.e. the TSN number that
2750 * was sent in the ECNE chunk. This element represents the lowest
2751 * TSN number in the datagram that was originally marked with the
2754 * Verification Tag: 8.5 Verification Tag [Normal verification]
2756 * (endpoint, asoc, chunk)
2759 * (asoc, reply_msg, msg_up, timers, counters)
2761 * The return value is the disposition of the chunk.
2763 sctp_disposition_t
sctp_sf_do_ecn_cwr(const struct sctp_endpoint
*ep
,
2764 const struct sctp_association
*asoc
,
2765 const sctp_subtype_t type
,
2767 sctp_cmd_seq_t
*commands
)
2770 struct sctp_chunk
*chunk
= arg
;
2773 if (!sctp_vtag_verify(chunk
, asoc
))
2774 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2776 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_ecne_chunk_t
)))
2777 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2780 cwr
= (sctp_cwrhdr_t
*) chunk
->skb
->data
;
2781 skb_pull(chunk
->skb
, sizeof(sctp_cwrhdr_t
));
2783 lowest_tsn
= ntohl(cwr
->lowest_tsn
);
2785 /* Does this CWR ack the last sent congestion notification? */
2786 if (TSN_lte(asoc
->last_ecne_tsn
, lowest_tsn
)) {
2787 /* Stop sending ECNE. */
2788 sctp_add_cmd_sf(commands
,
2790 SCTP_U32(lowest_tsn
));
2792 return SCTP_DISPOSITION_CONSUME
;
2798 * Section: Appendix A: Explicit Congestion Notification
2802 * RFC 2481 details a specific bit for a receiver to send back in its
2803 * TCP acknowledgements to notify the sender of the Congestion
2804 * Experienced (CE) bit having arrived from the network. For SCTP this
2805 * same indication is made by including the ECNE chunk. This chunk
2806 * contains one data element, i.e. the lowest TSN associated with the IP
2807 * datagram marked with the CE bit.....
2809 * Verification Tag: 8.5 Verification Tag [Normal verification]
2811 * (endpoint, asoc, chunk)
2814 * (asoc, reply_msg, msg_up, timers, counters)
2816 * The return value is the disposition of the chunk.
2818 sctp_disposition_t
sctp_sf_do_ecne(const struct sctp_endpoint
*ep
,
2819 const struct sctp_association
*asoc
,
2820 const sctp_subtype_t type
,
2822 sctp_cmd_seq_t
*commands
)
2824 sctp_ecnehdr_t
*ecne
;
2825 struct sctp_chunk
*chunk
= arg
;
2827 if (!sctp_vtag_verify(chunk
, asoc
))
2828 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2830 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_ecne_chunk_t
)))
2831 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2834 ecne
= (sctp_ecnehdr_t
*) chunk
->skb
->data
;
2835 skb_pull(chunk
->skb
, sizeof(sctp_ecnehdr_t
));
2837 /* If this is a newer ECNE than the last CWR packet we sent out */
2838 sctp_add_cmd_sf(commands
, SCTP_CMD_ECN_ECNE
,
2839 SCTP_U32(ntohl(ecne
->lowest_tsn
)));
2841 return SCTP_DISPOSITION_CONSUME
;
2845 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
2847 * The SCTP endpoint MUST always acknowledge the reception of each valid
2850 * The guidelines on delayed acknowledgement algorithm specified in
2851 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
2852 * acknowledgement SHOULD be generated for at least every second packet
2853 * (not every second DATA chunk) received, and SHOULD be generated within
2854 * 200 ms of the arrival of any unacknowledged DATA chunk. In some
2855 * situations it may be beneficial for an SCTP transmitter to be more
2856 * conservative than the algorithms detailed in this document allow.
2857 * However, an SCTP transmitter MUST NOT be more aggressive than the
2858 * following algorithms allow.
2860 * A SCTP receiver MUST NOT generate more than one SACK for every
2861 * incoming packet, other than to update the offered window as the
2862 * receiving application consumes new data.
2864 * Verification Tag: 8.5 Verification Tag [Normal verification]
2867 * (endpoint, asoc, chunk)
2870 * (asoc, reply_msg, msg_up, timers, counters)
2872 * The return value is the disposition of the chunk.
2874 sctp_disposition_t
sctp_sf_eat_data_6_2(const struct sctp_endpoint
*ep
,
2875 const struct sctp_association
*asoc
,
2876 const sctp_subtype_t type
,
2878 sctp_cmd_seq_t
*commands
)
2880 struct sctp_chunk
*chunk
= arg
;
2881 sctp_arg_t force
= SCTP_NOFORCE();
2884 if (!sctp_vtag_verify(chunk
, asoc
)) {
2885 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
2887 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2890 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_data_chunk_t
)))
2891 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2894 error
= sctp_eat_data(asoc
, chunk
, commands
);
2896 case SCTP_IERROR_NO_ERROR
:
2898 case SCTP_IERROR_HIGH_TSN
:
2899 case SCTP_IERROR_BAD_STREAM
:
2900 SCTP_INC_STATS(SCTP_MIB_IN_DATA_CHUNK_DISCARDS
);
2901 goto discard_noforce
;
2902 case SCTP_IERROR_DUP_TSN
:
2903 case SCTP_IERROR_IGNORE_TSN
:
2904 SCTP_INC_STATS(SCTP_MIB_IN_DATA_CHUNK_DISCARDS
);
2906 case SCTP_IERROR_NO_DATA
:
2908 case SCTP_IERROR_PROTO_VIOLATION
:
2909 return sctp_sf_abort_violation(ep
, asoc
, chunk
, commands
,
2910 (u8
*)chunk
->subh
.data_hdr
, sizeof(sctp_datahdr_t
));
2915 if (chunk
->chunk_hdr
->flags
& SCTP_DATA_SACK_IMM
)
2916 force
= SCTP_FORCE();
2918 if (asoc
->autoclose
) {
2919 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
2920 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
2923 /* If this is the last chunk in a packet, we need to count it
2924 * toward sack generation. Note that we need to SACK every
2925 * OTHER packet containing data chunks, EVEN IF WE DISCARD
2926 * THEM. We elect to NOT generate SACK's if the chunk fails
2927 * the verification tag test.
2929 * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2931 * The SCTP endpoint MUST always acknowledge the reception of
2932 * each valid DATA chunk.
2934 * The guidelines on delayed acknowledgement algorithm
2935 * specified in Section 4.2 of [RFC2581] SHOULD be followed.
2936 * Specifically, an acknowledgement SHOULD be generated for at
2937 * least every second packet (not every second DATA chunk)
2938 * received, and SHOULD be generated within 200 ms of the
2939 * arrival of any unacknowledged DATA chunk. In some
2940 * situations it may be beneficial for an SCTP transmitter to
2941 * be more conservative than the algorithms detailed in this
2942 * document allow. However, an SCTP transmitter MUST NOT be
2943 * more aggressive than the following algorithms allow.
2945 if (chunk
->end_of_packet
)
2946 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, force
);
2948 return SCTP_DISPOSITION_CONSUME
;
2951 /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2953 * When a packet arrives with duplicate DATA chunk(s) and with
2954 * no new DATA chunk(s), the endpoint MUST immediately send a
2955 * SACK with no delay. If a packet arrives with duplicate
2956 * DATA chunk(s) bundled with new DATA chunks, the endpoint
2957 * MAY immediately send a SACK. Normally receipt of duplicate
2958 * DATA chunks will occur when the original SACK chunk was lost
2959 * and the peer's RTO has expired. The duplicate TSN number(s)
2960 * SHOULD be reported in the SACK as duplicate.
2962 /* In our case, we split the MAY SACK advice up whether or not
2963 * the last chunk is a duplicate.'
2965 if (chunk
->end_of_packet
)
2966 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_FORCE());
2967 return SCTP_DISPOSITION_DISCARD
;
2970 if (chunk
->end_of_packet
)
2971 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, force
);
2973 return SCTP_DISPOSITION_DISCARD
;
2975 return SCTP_DISPOSITION_CONSUME
;
2980 * sctp_sf_eat_data_fast_4_4
2983 * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received
2984 * DATA chunks without delay.
2986 * Verification Tag: 8.5 Verification Tag [Normal verification]
2988 * (endpoint, asoc, chunk)
2991 * (asoc, reply_msg, msg_up, timers, counters)
2993 * The return value is the disposition of the chunk.
2995 sctp_disposition_t
sctp_sf_eat_data_fast_4_4(const struct sctp_endpoint
*ep
,
2996 const struct sctp_association
*asoc
,
2997 const sctp_subtype_t type
,
2999 sctp_cmd_seq_t
*commands
)
3001 struct sctp_chunk
*chunk
= arg
;
3004 if (!sctp_vtag_verify(chunk
, asoc
)) {
3005 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3007 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3010 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_data_chunk_t
)))
3011 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3014 error
= sctp_eat_data(asoc
, chunk
, commands
);
3016 case SCTP_IERROR_NO_ERROR
:
3017 case SCTP_IERROR_HIGH_TSN
:
3018 case SCTP_IERROR_DUP_TSN
:
3019 case SCTP_IERROR_IGNORE_TSN
:
3020 case SCTP_IERROR_BAD_STREAM
:
3022 case SCTP_IERROR_NO_DATA
:
3024 case SCTP_IERROR_PROTO_VIOLATION
:
3025 return sctp_sf_abort_violation(ep
, asoc
, chunk
, commands
,
3026 (u8
*)chunk
->subh
.data_hdr
, sizeof(sctp_datahdr_t
));
3031 /* Go a head and force a SACK, since we are shutting down. */
3033 /* Implementor's Guide.
3035 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3036 * respond to each received packet containing one or more DATA chunk(s)
3037 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3039 if (chunk
->end_of_packet
) {
3040 /* We must delay the chunk creation since the cumulative
3041 * TSN has not been updated yet.
3043 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SHUTDOWN
, SCTP_NULL());
3044 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_FORCE());
3045 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
3046 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
3050 return SCTP_DISPOSITION_CONSUME
;
3054 * Section: 6.2 Processing a Received SACK
3055 * D) Any time a SACK arrives, the endpoint performs the following:
3057 * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point,
3058 * then drop the SACK. Since Cumulative TSN Ack is monotonically
3059 * increasing, a SACK whose Cumulative TSN Ack is less than the
3060 * Cumulative TSN Ack Point indicates an out-of-order SACK.
3062 * ii) Set rwnd equal to the newly received a_rwnd minus the number
3063 * of bytes still outstanding after processing the Cumulative TSN Ack
3064 * and the Gap Ack Blocks.
3066 * iii) If the SACK is missing a TSN that was previously
3067 * acknowledged via a Gap Ack Block (e.g., the data receiver
3068 * reneged on the data), then mark the corresponding DATA chunk
3069 * as available for retransmit: Mark it as missing for fast
3070 * retransmit as described in Section 7.2.4 and if no retransmit
3071 * timer is running for the destination address to which the DATA
3072 * chunk was originally transmitted, then T3-rtx is started for
3073 * that destination address.
3075 * Verification Tag: 8.5 Verification Tag [Normal verification]
3078 * (endpoint, asoc, chunk)
3081 * (asoc, reply_msg, msg_up, timers, counters)
3083 * The return value is the disposition of the chunk.
3085 sctp_disposition_t
sctp_sf_eat_sack_6_2(const struct sctp_endpoint
*ep
,
3086 const struct sctp_association
*asoc
,
3087 const sctp_subtype_t type
,
3089 sctp_cmd_seq_t
*commands
)
3091 struct sctp_chunk
*chunk
= arg
;
3092 sctp_sackhdr_t
*sackh
;
3095 if (!sctp_vtag_verify(chunk
, asoc
))
3096 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3098 /* Make sure that the SACK chunk has a valid length. */
3099 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_sack_chunk_t
)))
3100 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3103 /* Pull the SACK chunk from the data buffer */
3104 sackh
= sctp_sm_pull_sack(chunk
);
3105 /* Was this a bogus SACK? */
3107 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3108 chunk
->subh
.sack_hdr
= sackh
;
3109 ctsn
= ntohl(sackh
->cum_tsn_ack
);
3111 /* i) If Cumulative TSN Ack is less than the Cumulative TSN
3112 * Ack Point, then drop the SACK. Since Cumulative TSN
3113 * Ack is monotonically increasing, a SACK whose
3114 * Cumulative TSN Ack is less than the Cumulative TSN Ack
3115 * Point indicates an out-of-order SACK.
3117 if (TSN_lt(ctsn
, asoc
->ctsn_ack_point
)) {
3118 SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn
);
3119 SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc
->ctsn_ack_point
);
3120 return SCTP_DISPOSITION_DISCARD
;
3123 /* If Cumulative TSN Ack beyond the max tsn currently
3124 * send, terminating the association and respond to the
3125 * sender with an ABORT.
3127 if (!TSN_lt(ctsn
, asoc
->next_tsn
))
3128 return sctp_sf_violation_ctsn(ep
, asoc
, type
, arg
, commands
);
3130 /* Return this SACK for further processing. */
3131 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_SACK
, SCTP_SACKH(sackh
));
3133 /* Note: We do the rest of the work on the PROCESS_SACK
3136 return SCTP_DISPOSITION_CONSUME
;
3140 * Generate an ABORT in response to a packet.
3142 * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41
3144 * 8) The receiver should respond to the sender of the OOTB packet with
3145 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3146 * MUST fill in the Verification Tag field of the outbound packet
3147 * with the value found in the Verification Tag field of the OOTB
3148 * packet and set the T-bit in the Chunk Flags to indicate that the
3149 * Verification Tag is reflected. After sending this ABORT, the
3150 * receiver of the OOTB packet shall discard the OOTB packet and take
3151 * no further action.
3155 * The return value is the disposition of the chunk.
3157 static sctp_disposition_t
sctp_sf_tabort_8_4_8(const struct sctp_endpoint
*ep
,
3158 const struct sctp_association
*asoc
,
3159 const sctp_subtype_t type
,
3161 sctp_cmd_seq_t
*commands
)
3163 struct sctp_packet
*packet
= NULL
;
3164 struct sctp_chunk
*chunk
= arg
;
3165 struct sctp_chunk
*abort
;
3167 packet
= sctp_ootb_pkt_new(asoc
, chunk
);
3170 /* Make an ABORT. The T bit will be set if the asoc
3173 abort
= sctp_make_abort(asoc
, chunk
, 0);
3175 sctp_ootb_pkt_free(packet
);
3176 return SCTP_DISPOSITION_NOMEM
;
3179 /* Reflect vtag if T-Bit is set */
3180 if (sctp_test_T_bit(abort
))
3181 packet
->vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
3183 /* Set the skb to the belonging sock for accounting. */
3184 abort
->skb
->sk
= ep
->base
.sk
;
3186 sctp_packet_append_chunk(packet
, abort
);
3188 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
3189 SCTP_PACKET(packet
));
3191 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
3193 sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3194 return SCTP_DISPOSITION_CONSUME
;
3197 return SCTP_DISPOSITION_NOMEM
;
3201 * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR
3202 * event as ULP notification for each cause included in the chunk.
3204 * API 5.3.1.3 - SCTP_REMOTE_ERROR
3206 * The return value is the disposition of the chunk.
3208 sctp_disposition_t
sctp_sf_operr_notify(const struct sctp_endpoint
*ep
,
3209 const struct sctp_association
*asoc
,
3210 const sctp_subtype_t type
,
3212 sctp_cmd_seq_t
*commands
)
3214 struct sctp_chunk
*chunk
= arg
;
3217 if (!sctp_vtag_verify(chunk
, asoc
))
3218 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3220 /* Make sure that the ERROR chunk has a valid length. */
3221 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_operr_chunk_t
)))
3222 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3224 sctp_walk_errors(err
, chunk
->chunk_hdr
);
3225 if ((void *)err
!= (void *)chunk
->chunk_end
)
3226 return sctp_sf_violation_paramlen(ep
, asoc
, type
, arg
,
3227 (void *)err
, commands
);
3229 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_OPERR
,
3232 return SCTP_DISPOSITION_CONSUME
;
3236 * Process an inbound SHUTDOWN ACK.
3239 * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3240 * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its
3241 * peer, and remove all record of the association.
3243 * The return value is the disposition.
3245 sctp_disposition_t
sctp_sf_do_9_2_final(const struct sctp_endpoint
*ep
,
3246 const struct sctp_association
*asoc
,
3247 const sctp_subtype_t type
,
3249 sctp_cmd_seq_t
*commands
)
3251 struct sctp_chunk
*chunk
= arg
;
3252 struct sctp_chunk
*reply
;
3253 struct sctp_ulpevent
*ev
;
3255 if (!sctp_vtag_verify(chunk
, asoc
))
3256 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3258 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3259 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
3260 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3262 /* 10.2 H) SHUTDOWN COMPLETE notification
3264 * When SCTP completes the shutdown procedures (section 9.2) this
3265 * notification is passed to the upper layer.
3267 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_SHUTDOWN_COMP
,
3268 0, 0, 0, NULL
, GFP_ATOMIC
);
3272 /* ...send a SHUTDOWN COMPLETE chunk to its peer, */
3273 reply
= sctp_make_shutdown_complete(asoc
, chunk
);
3277 /* Do all the commands now (after allocation), so that we
3278 * have consistent state if memory allocation failes
3280 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
3282 /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3283 * stop the T2-shutdown timer,
3285 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3286 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
3288 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3289 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
3291 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
3292 SCTP_STATE(SCTP_STATE_CLOSED
));
3293 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS
);
3294 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
3295 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
3297 /* ...and remove all record of the association. */
3298 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
3299 return SCTP_DISPOSITION_DELETE_TCB
;
3302 sctp_ulpevent_free(ev
);
3304 return SCTP_DISPOSITION_NOMEM
;
3308 * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41.
3310 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3311 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3312 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3313 * packet must fill in the Verification Tag field of the outbound
3314 * packet with the Verification Tag received in the SHUTDOWN ACK and
3315 * set the T-bit in the Chunk Flags to indicate that the Verification
3318 * 8) The receiver should respond to the sender of the OOTB packet with
3319 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3320 * MUST fill in the Verification Tag field of the outbound packet
3321 * with the value found in the Verification Tag field of the OOTB
3322 * packet and set the T-bit in the Chunk Flags to indicate that the
3323 * Verification Tag is reflected. After sending this ABORT, the
3324 * receiver of the OOTB packet shall discard the OOTB packet and take
3325 * no further action.
3327 sctp_disposition_t
sctp_sf_ootb(const struct sctp_endpoint
*ep
,
3328 const struct sctp_association
*asoc
,
3329 const sctp_subtype_t type
,
3331 sctp_cmd_seq_t
*commands
)
3333 struct sctp_chunk
*chunk
= arg
;
3334 struct sk_buff
*skb
= chunk
->skb
;
3335 sctp_chunkhdr_t
*ch
;
3338 int ootb_shut_ack
= 0;
3339 int ootb_cookie_ack
= 0;
3341 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES
);
3343 ch
= (sctp_chunkhdr_t
*) chunk
->chunk_hdr
;
3345 /* Report violation if the chunk is less then minimal */
3346 if (ntohs(ch
->length
) < sizeof(sctp_chunkhdr_t
))
3347 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3350 /* Now that we know we at least have a chunk header,
3351 * do things that are type appropriate.
3353 if (SCTP_CID_SHUTDOWN_ACK
== ch
->type
)
3356 /* RFC 2960, Section 3.3.7
3357 * Moreover, under any circumstances, an endpoint that
3358 * receives an ABORT MUST NOT respond to that ABORT by
3359 * sending an ABORT of its own.
3361 if (SCTP_CID_ABORT
== ch
->type
)
3362 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3364 /* RFC 8.4, 7) If the packet contains a "Stale cookie" ERROR
3365 * or a COOKIE ACK the SCTP Packet should be silently
3369 if (SCTP_CID_COOKIE_ACK
== ch
->type
)
3370 ootb_cookie_ack
= 1;
3372 if (SCTP_CID_ERROR
== ch
->type
) {
3373 sctp_walk_errors(err
, ch
) {
3374 if (SCTP_ERROR_STALE_COOKIE
== err
->cause
) {
3375 ootb_cookie_ack
= 1;
3381 /* Report violation if chunk len overflows */
3382 ch_end
= ((__u8
*)ch
) + WORD_ROUND(ntohs(ch
->length
));
3383 if (ch_end
> skb_tail_pointer(skb
))
3384 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3387 ch
= (sctp_chunkhdr_t
*) ch_end
;
3388 } while (ch_end
< skb_tail_pointer(skb
));
3391 return sctp_sf_shut_8_4_5(ep
, asoc
, type
, arg
, commands
);
3392 else if (ootb_cookie_ack
)
3393 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3395 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
, commands
);
3399 * Handle an "Out of the blue" SHUTDOWN ACK.
3401 * Section: 8.4 5, sctpimpguide 2.41.
3403 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3404 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3405 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3406 * packet must fill in the Verification Tag field of the outbound
3407 * packet with the Verification Tag received in the SHUTDOWN ACK and
3408 * set the T-bit in the Chunk Flags to indicate that the Verification
3412 * (endpoint, asoc, type, arg, commands)
3415 * (sctp_disposition_t)
3417 * The return value is the disposition of the chunk.
3419 static sctp_disposition_t
sctp_sf_shut_8_4_5(const struct sctp_endpoint
*ep
,
3420 const struct sctp_association
*asoc
,
3421 const sctp_subtype_t type
,
3423 sctp_cmd_seq_t
*commands
)
3425 struct sctp_packet
*packet
= NULL
;
3426 struct sctp_chunk
*chunk
= arg
;
3427 struct sctp_chunk
*shut
;
3429 packet
= sctp_ootb_pkt_new(asoc
, chunk
);
3432 /* Make an SHUTDOWN_COMPLETE.
3433 * The T bit will be set if the asoc is NULL.
3435 shut
= sctp_make_shutdown_complete(asoc
, chunk
);
3437 sctp_ootb_pkt_free(packet
);
3438 return SCTP_DISPOSITION_NOMEM
;
3441 /* Reflect vtag if T-Bit is set */
3442 if (sctp_test_T_bit(shut
))
3443 packet
->vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
3445 /* Set the skb to the belonging sock for accounting. */
3446 shut
->skb
->sk
= ep
->base
.sk
;
3448 sctp_packet_append_chunk(packet
, shut
);
3450 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
3451 SCTP_PACKET(packet
));
3453 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
3455 /* If the chunk length is invalid, we don't want to process
3456 * the reset of the packet.
3458 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
3459 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3461 /* We need to discard the rest of the packet to prevent
3462 * potential bomming attacks from additional bundled chunks.
3463 * This is documented in SCTP Threats ID.
3465 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3468 return SCTP_DISPOSITION_NOMEM
;
3472 * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state.
3474 * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK
3475 * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the
3476 * procedures in section 8.4 SHOULD be followed, in other words it
3477 * should be treated as an Out Of The Blue packet.
3478 * [This means that we do NOT check the Verification Tag on these
3482 sctp_disposition_t
sctp_sf_do_8_5_1_E_sa(const struct sctp_endpoint
*ep
,
3483 const struct sctp_association
*asoc
,
3484 const sctp_subtype_t type
,
3486 sctp_cmd_seq_t
*commands
)
3488 struct sctp_chunk
*chunk
= arg
;
3490 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3491 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
3492 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3495 /* Although we do have an association in this case, it corresponds
3496 * to a restarted association. So the packet is treated as an OOTB
3497 * packet and the state function that handles OOTB SHUTDOWN_ACK is
3498 * called with a NULL association.
3500 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES
);
3502 return sctp_sf_shut_8_4_5(ep
, NULL
, type
, arg
, commands
);
3505 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */
3506 sctp_disposition_t
sctp_sf_do_asconf(const struct sctp_endpoint
*ep
,
3507 const struct sctp_association
*asoc
,
3508 const sctp_subtype_t type
, void *arg
,
3509 sctp_cmd_seq_t
*commands
)
3511 struct sctp_chunk
*chunk
= arg
;
3512 struct sctp_chunk
*asconf_ack
= NULL
;
3513 struct sctp_paramhdr
*err_param
= NULL
;
3514 sctp_addiphdr_t
*hdr
;
3515 union sctp_addr_param
*addr_param
;
3519 if (!sctp_vtag_verify(chunk
, asoc
)) {
3520 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3522 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3525 /* ADD-IP: Section 4.1.1
3526 * This chunk MUST be sent in an authenticated way by using
3527 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3528 * is received unauthenticated it MUST be silently discarded as
3529 * described in [I-D.ietf-tsvwg-sctp-auth].
3531 if (!sctp_addip_noauth
&& !chunk
->auth
)
3532 return sctp_sf_discard_chunk(ep
, asoc
, type
, arg
, commands
);
3534 /* Make sure that the ASCONF ADDIP chunk has a valid length. */
3535 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_addip_chunk_t
)))
3536 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3539 hdr
= (sctp_addiphdr_t
*)chunk
->skb
->data
;
3540 serial
= ntohl(hdr
->serial
);
3542 addr_param
= (union sctp_addr_param
*)hdr
->params
;
3543 length
= ntohs(addr_param
->p
.length
);
3544 if (length
< sizeof(sctp_paramhdr_t
))
3545 return sctp_sf_violation_paramlen(ep
, asoc
, type
, arg
,
3546 (void *)addr_param
, commands
);
3548 /* Verify the ASCONF chunk before processing it. */
3549 if (!sctp_verify_asconf(asoc
,
3550 (sctp_paramhdr_t
*)((void *)addr_param
+ length
),
3551 (void *)chunk
->chunk_end
,
3553 return sctp_sf_violation_paramlen(ep
, asoc
, type
, arg
,
3554 (void *)err_param
, commands
);
3556 /* ADDIP 5.2 E1) Compare the value of the serial number to the value
3557 * the endpoint stored in a new association variable
3558 * 'Peer-Serial-Number'.
3560 if (serial
== asoc
->peer
.addip_serial
+ 1) {
3561 /* If this is the first instance of ASCONF in the packet,
3562 * we can clean our old ASCONF-ACKs.
3564 if (!chunk
->has_asconf
)
3565 sctp_assoc_clean_asconf_ack_cache(asoc
);
3567 /* ADDIP 5.2 E4) When the Sequence Number matches the next one
3568 * expected, process the ASCONF as described below and after
3569 * processing the ASCONF Chunk, append an ASCONF-ACK Chunk to
3570 * the response packet and cache a copy of it (in the event it
3571 * later needs to be retransmitted).
3573 * Essentially, do V1-V5.
3575 asconf_ack
= sctp_process_asconf((struct sctp_association
*)
3578 return SCTP_DISPOSITION_NOMEM
;
3579 } else if (serial
< asoc
->peer
.addip_serial
+ 1) {
3581 * If the value found in the Sequence Number is less than the
3582 * ('Peer- Sequence-Number' + 1), simply skip to the next
3583 * ASCONF, and include in the outbound response packet
3584 * any previously cached ASCONF-ACK response that was
3585 * sent and saved that matches the Sequence Number of the
3586 * ASCONF. Note: It is possible that no cached ASCONF-ACK
3587 * Chunk exists. This will occur when an older ASCONF
3588 * arrives out of order. In such a case, the receiver
3589 * should skip the ASCONF Chunk and not include ASCONF-ACK
3590 * Chunk for that chunk.
3592 asconf_ack
= sctp_assoc_lookup_asconf_ack(asoc
, hdr
->serial
);
3594 return SCTP_DISPOSITION_DISCARD
;
3596 /* Reset the transport so that we select the correct one
3597 * this time around. This is to make sure that we don't
3598 * accidentally use a stale transport that's been removed.
3600 asconf_ack
->transport
= NULL
;
3602 /* ADDIP 5.2 E5) Otherwise, the ASCONF Chunk is discarded since
3603 * it must be either a stale packet or from an attacker.
3605 return SCTP_DISPOSITION_DISCARD
;
3608 /* ADDIP 5.2 E6) The destination address of the SCTP packet
3609 * containing the ASCONF-ACK Chunks MUST be the source address of
3610 * the SCTP packet that held the ASCONF Chunks.
3612 * To do this properly, we'll set the destination address of the chunk
3613 * and at the transmit time, will try look up the transport to use.
3614 * Since ASCONFs may be bundled, the correct transport may not be
3615 * created until we process the entire packet, thus this workaround.
3617 asconf_ack
->dest
= chunk
->source
;
3618 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(asconf_ack
));
3619 if (asoc
->new_transport
) {
3620 sctp_sf_heartbeat(ep
, asoc
, type
, asoc
->new_transport
,
3622 ((struct sctp_association
*)asoc
)->new_transport
= NULL
;
3625 return SCTP_DISPOSITION_CONSUME
;
3629 * ADDIP Section 4.3 General rules for address manipulation
3630 * When building TLV parameters for the ASCONF Chunk that will add or
3631 * delete IP addresses the D0 to D13 rules should be applied:
3633 sctp_disposition_t
sctp_sf_do_asconf_ack(const struct sctp_endpoint
*ep
,
3634 const struct sctp_association
*asoc
,
3635 const sctp_subtype_t type
, void *arg
,
3636 sctp_cmd_seq_t
*commands
)
3638 struct sctp_chunk
*asconf_ack
= arg
;
3639 struct sctp_chunk
*last_asconf
= asoc
->addip_last_asconf
;
3640 struct sctp_chunk
*abort
;
3641 struct sctp_paramhdr
*err_param
= NULL
;
3642 sctp_addiphdr_t
*addip_hdr
;
3643 __u32 sent_serial
, rcvd_serial
;
3645 if (!sctp_vtag_verify(asconf_ack
, asoc
)) {
3646 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3648 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3651 /* ADD-IP, Section 4.1.2:
3652 * This chunk MUST be sent in an authenticated way by using
3653 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3654 * is received unauthenticated it MUST be silently discarded as
3655 * described in [I-D.ietf-tsvwg-sctp-auth].
3657 if (!sctp_addip_noauth
&& !asconf_ack
->auth
)
3658 return sctp_sf_discard_chunk(ep
, asoc
, type
, arg
, commands
);
3660 /* Make sure that the ADDIP chunk has a valid length. */
3661 if (!sctp_chunk_length_valid(asconf_ack
, sizeof(sctp_addip_chunk_t
)))
3662 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3665 addip_hdr
= (sctp_addiphdr_t
*)asconf_ack
->skb
->data
;
3666 rcvd_serial
= ntohl(addip_hdr
->serial
);
3668 /* Verify the ASCONF-ACK chunk before processing it. */
3669 if (!sctp_verify_asconf(asoc
,
3670 (sctp_paramhdr_t
*)addip_hdr
->params
,
3671 (void *)asconf_ack
->chunk_end
,
3673 return sctp_sf_violation_paramlen(ep
, asoc
, type
, arg
,
3674 (void *)err_param
, commands
);
3677 addip_hdr
= (sctp_addiphdr_t
*)last_asconf
->subh
.addip_hdr
;
3678 sent_serial
= ntohl(addip_hdr
->serial
);
3680 sent_serial
= asoc
->addip_serial
- 1;
3683 /* D0) If an endpoint receives an ASCONF-ACK that is greater than or
3684 * equal to the next serial number to be used but no ASCONF chunk is
3685 * outstanding the endpoint MUST ABORT the association. Note that a
3686 * sequence number is greater than if it is no more than 2^^31-1
3687 * larger than the current sequence number (using serial arithmetic).
3689 if (ADDIP_SERIAL_gte(rcvd_serial
, sent_serial
+ 1) &&
3690 !(asoc
->addip_last_asconf
)) {
3691 abort
= sctp_make_abort(asoc
, asconf_ack
,
3692 sizeof(sctp_errhdr_t
));
3694 sctp_init_cause(abort
, SCTP_ERROR_ASCONF_ACK
, 0);
3695 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
3698 /* We are going to ABORT, so we might as well stop
3699 * processing the rest of the chunks in the packet.
3701 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3702 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
3703 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
,SCTP_NULL());
3704 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
3705 SCTP_ERROR(ECONNABORTED
));
3706 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
3707 SCTP_PERR(SCTP_ERROR_ASCONF_ACK
));
3708 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
3709 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
3710 return SCTP_DISPOSITION_ABORT
;
3713 if ((rcvd_serial
== sent_serial
) && asoc
->addip_last_asconf
) {
3714 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3715 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
3717 if (!sctp_process_asconf_ack((struct sctp_association
*)asoc
,
3719 /* Successfully processed ASCONF_ACK. We can
3720 * release the next asconf if we have one.
3722 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_NEXT_ASCONF
,
3724 return SCTP_DISPOSITION_CONSUME
;
3727 abort
= sctp_make_abort(asoc
, asconf_ack
,
3728 sizeof(sctp_errhdr_t
));
3730 sctp_init_cause(abort
, SCTP_ERROR_RSRC_LOW
, 0);
3731 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
3734 /* We are going to ABORT, so we might as well stop
3735 * processing the rest of the chunks in the packet.
3737 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
,SCTP_NULL());
3738 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
3739 SCTP_ERROR(ECONNABORTED
));
3740 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
3741 SCTP_PERR(SCTP_ERROR_ASCONF_ACK
));
3742 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
3743 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
3744 return SCTP_DISPOSITION_ABORT
;
3747 return SCTP_DISPOSITION_DISCARD
;
3751 * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP
3753 * When a FORWARD TSN chunk arrives, the data receiver MUST first update
3754 * its cumulative TSN point to the value carried in the FORWARD TSN
3755 * chunk, and then MUST further advance its cumulative TSN point locally
3757 * After the above processing, the data receiver MUST stop reporting any
3758 * missing TSNs earlier than or equal to the new cumulative TSN point.
3760 * Verification Tag: 8.5 Verification Tag [Normal verification]
3762 * The return value is the disposition of the chunk.
3764 sctp_disposition_t
sctp_sf_eat_fwd_tsn(const struct sctp_endpoint
*ep
,
3765 const struct sctp_association
*asoc
,
3766 const sctp_subtype_t type
,
3768 sctp_cmd_seq_t
*commands
)
3770 struct sctp_chunk
*chunk
= arg
;
3771 struct sctp_fwdtsn_hdr
*fwdtsn_hdr
;
3772 struct sctp_fwdtsn_skip
*skip
;
3776 if (!sctp_vtag_verify(chunk
, asoc
)) {
3777 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3779 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3782 /* Make sure that the FORWARD_TSN chunk has valid length. */
3783 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_fwdtsn_chunk
)))
3784 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3787 fwdtsn_hdr
= (struct sctp_fwdtsn_hdr
*)chunk
->skb
->data
;
3788 chunk
->subh
.fwdtsn_hdr
= fwdtsn_hdr
;
3789 len
= ntohs(chunk
->chunk_hdr
->length
);
3790 len
-= sizeof(struct sctp_chunkhdr
);
3791 skb_pull(chunk
->skb
, len
);
3793 tsn
= ntohl(fwdtsn_hdr
->new_cum_tsn
);
3794 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __func__
, tsn
);
3796 /* The TSN is too high--silently discard the chunk and count on it
3797 * getting retransmitted later.
3799 if (sctp_tsnmap_check(&asoc
->peer
.tsn_map
, tsn
) < 0)
3800 goto discard_noforce
;
3802 /* Silently discard the chunk if stream-id is not valid */
3803 sctp_walk_fwdtsn(skip
, chunk
) {
3804 if (ntohs(skip
->stream
) >= asoc
->c
.sinit_max_instreams
)
3805 goto discard_noforce
;
3808 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_FWDTSN
, SCTP_U32(tsn
));
3809 if (len
> sizeof(struct sctp_fwdtsn_hdr
))
3810 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_FWDTSN
,
3813 /* Count this as receiving DATA. */
3814 if (asoc
->autoclose
) {
3815 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
3816 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
3819 /* FIXME: For now send a SACK, but DATA processing may
3822 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_NOFORCE());
3824 return SCTP_DISPOSITION_CONSUME
;
3827 return SCTP_DISPOSITION_DISCARD
;
3830 sctp_disposition_t
sctp_sf_eat_fwd_tsn_fast(
3831 const struct sctp_endpoint
*ep
,
3832 const struct sctp_association
*asoc
,
3833 const sctp_subtype_t type
,
3835 sctp_cmd_seq_t
*commands
)
3837 struct sctp_chunk
*chunk
= arg
;
3838 struct sctp_fwdtsn_hdr
*fwdtsn_hdr
;
3839 struct sctp_fwdtsn_skip
*skip
;
3843 if (!sctp_vtag_verify(chunk
, asoc
)) {
3844 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3846 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3849 /* Make sure that the FORWARD_TSN chunk has a valid length. */
3850 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_fwdtsn_chunk
)))
3851 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3854 fwdtsn_hdr
= (struct sctp_fwdtsn_hdr
*)chunk
->skb
->data
;
3855 chunk
->subh
.fwdtsn_hdr
= fwdtsn_hdr
;
3856 len
= ntohs(chunk
->chunk_hdr
->length
);
3857 len
-= sizeof(struct sctp_chunkhdr
);
3858 skb_pull(chunk
->skb
, len
);
3860 tsn
= ntohl(fwdtsn_hdr
->new_cum_tsn
);
3861 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __func__
, tsn
);
3863 /* The TSN is too high--silently discard the chunk and count on it
3864 * getting retransmitted later.
3866 if (sctp_tsnmap_check(&asoc
->peer
.tsn_map
, tsn
) < 0)
3869 /* Silently discard the chunk if stream-id is not valid */
3870 sctp_walk_fwdtsn(skip
, chunk
) {
3871 if (ntohs(skip
->stream
) >= asoc
->c
.sinit_max_instreams
)
3875 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_FWDTSN
, SCTP_U32(tsn
));
3876 if (len
> sizeof(struct sctp_fwdtsn_hdr
))
3877 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_FWDTSN
,
3880 /* Go a head and force a SACK, since we are shutting down. */
3882 /* Implementor's Guide.
3884 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3885 * respond to each received packet containing one or more DATA chunk(s)
3886 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3888 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SHUTDOWN
, SCTP_NULL());
3889 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_FORCE());
3890 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
3891 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
3893 return SCTP_DISPOSITION_CONSUME
;
3897 * SCTP-AUTH Section 6.3 Receiving authenticated chukns
3899 * The receiver MUST use the HMAC algorithm indicated in the HMAC
3900 * Identifier field. If this algorithm was not specified by the
3901 * receiver in the HMAC-ALGO parameter in the INIT or INIT-ACK chunk
3902 * during association setup, the AUTH chunk and all chunks after it MUST
3903 * be discarded and an ERROR chunk SHOULD be sent with the error cause
3904 * defined in Section 4.1.
3906 * If an endpoint with no shared key receives a Shared Key Identifier
3907 * other than 0, it MUST silently discard all authenticated chunks. If
3908 * the endpoint has at least one endpoint pair shared key for the peer,
3909 * it MUST use the key specified by the Shared Key Identifier if a
3910 * key has been configured for that Shared Key Identifier. If no
3911 * endpoint pair shared key has been configured for that Shared Key
3912 * Identifier, all authenticated chunks MUST be silently discarded.
3914 * Verification Tag: 8.5 Verification Tag [Normal verification]
3916 * The return value is the disposition of the chunk.
3918 static sctp_ierror_t
sctp_sf_authenticate(const struct sctp_endpoint
*ep
,
3919 const struct sctp_association
*asoc
,
3920 const sctp_subtype_t type
,
3921 struct sctp_chunk
*chunk
)
3923 struct sctp_authhdr
*auth_hdr
;
3924 struct sctp_hmac
*hmac
;
3925 unsigned int sig_len
;
3930 /* Pull in the auth header, so we can do some more verification */
3931 auth_hdr
= (struct sctp_authhdr
*)chunk
->skb
->data
;
3932 chunk
->subh
.auth_hdr
= auth_hdr
;
3933 skb_pull(chunk
->skb
, sizeof(struct sctp_authhdr
));
3935 /* Make sure that we suport the HMAC algorithm from the auth
3938 if (!sctp_auth_asoc_verify_hmac_id(asoc
, auth_hdr
->hmac_id
))
3939 return SCTP_IERROR_AUTH_BAD_HMAC
;
3941 /* Make sure that the provided shared key identifier has been
3944 key_id
= ntohs(auth_hdr
->shkey_id
);
3945 if (key_id
!= asoc
->active_key_id
&& !sctp_auth_get_shkey(asoc
, key_id
))
3946 return SCTP_IERROR_AUTH_BAD_KEYID
;
3949 /* Make sure that the length of the signature matches what
3952 sig_len
= ntohs(chunk
->chunk_hdr
->length
) - sizeof(sctp_auth_chunk_t
);
3953 hmac
= sctp_auth_get_hmac(ntohs(auth_hdr
->hmac_id
));
3954 if (sig_len
!= hmac
->hmac_len
)
3955 return SCTP_IERROR_PROTO_VIOLATION
;
3957 /* Now that we've done validation checks, we can compute and
3958 * verify the hmac. The steps involved are:
3959 * 1. Save the digest from the chunk.
3960 * 2. Zero out the digest in the chunk.
3961 * 3. Compute the new digest
3962 * 4. Compare saved and new digests.
3964 digest
= auth_hdr
->hmac
;
3965 skb_pull(chunk
->skb
, sig_len
);
3967 save_digest
= kmemdup(digest
, sig_len
, GFP_ATOMIC
);
3971 memset(digest
, 0, sig_len
);
3973 sctp_auth_calculate_hmac(asoc
, chunk
->skb
,
3974 (struct sctp_auth_chunk
*)chunk
->chunk_hdr
,
3977 /* Discard the packet if the digests do not match */
3978 if (memcmp(save_digest
, digest
, sig_len
)) {
3980 return SCTP_IERROR_BAD_SIG
;
3986 return SCTP_IERROR_NO_ERROR
;
3988 return SCTP_IERROR_NOMEM
;
3991 sctp_disposition_t
sctp_sf_eat_auth(const struct sctp_endpoint
*ep
,
3992 const struct sctp_association
*asoc
,
3993 const sctp_subtype_t type
,
3995 sctp_cmd_seq_t
*commands
)
3997 struct sctp_authhdr
*auth_hdr
;
3998 struct sctp_chunk
*chunk
= arg
;
3999 struct sctp_chunk
*err_chunk
;
4000 sctp_ierror_t error
;
4002 /* Make sure that the peer has AUTH capable */
4003 if (!asoc
->peer
.auth_capable
)
4004 return sctp_sf_unk_chunk(ep
, asoc
, type
, arg
, commands
);
4006 if (!sctp_vtag_verify(chunk
, asoc
)) {
4007 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
4009 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
4012 /* Make sure that the AUTH chunk has valid length. */
4013 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_auth_chunk
)))
4014 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
4017 auth_hdr
= (struct sctp_authhdr
*)chunk
->skb
->data
;
4018 error
= sctp_sf_authenticate(ep
, asoc
, type
, chunk
);
4020 case SCTP_IERROR_AUTH_BAD_HMAC
:
4021 /* Generate the ERROR chunk and discard the rest
4024 err_chunk
= sctp_make_op_error(asoc
, chunk
,
4025 SCTP_ERROR_UNSUP_HMAC
,
4029 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
4030 SCTP_CHUNK(err_chunk
));
4033 case SCTP_IERROR_AUTH_BAD_KEYID
:
4034 case SCTP_IERROR_BAD_SIG
:
4035 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
4037 case SCTP_IERROR_PROTO_VIOLATION
:
4038 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
4041 case SCTP_IERROR_NOMEM
:
4042 return SCTP_DISPOSITION_NOMEM
;
4044 default: /* Prevent gcc warnings */
4048 if (asoc
->active_key_id
!= ntohs(auth_hdr
->shkey_id
)) {
4049 struct sctp_ulpevent
*ev
;
4051 ev
= sctp_ulpevent_make_authkey(asoc
, ntohs(auth_hdr
->shkey_id
),
4052 SCTP_AUTH_NEWKEY
, GFP_ATOMIC
);
4057 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
4061 return SCTP_DISPOSITION_CONSUME
;
4065 * Process an unknown chunk.
4067 * Section: 3.2. Also, 2.1 in the implementor's guide.
4069 * Chunk Types are encoded such that the highest-order two bits specify
4070 * the action that must be taken if the processing endpoint does not
4071 * recognize the Chunk Type.
4073 * 00 - Stop processing this SCTP packet and discard it, do not process
4074 * any further chunks within it.
4076 * 01 - Stop processing this SCTP packet and discard it, do not process
4077 * any further chunks within it, and report the unrecognized
4078 * chunk in an 'Unrecognized Chunk Type'.
4080 * 10 - Skip this chunk and continue processing.
4082 * 11 - Skip this chunk and continue processing, but report in an ERROR
4083 * Chunk using the 'Unrecognized Chunk Type' cause of error.
4085 * The return value is the disposition of the chunk.
4087 sctp_disposition_t
sctp_sf_unk_chunk(const struct sctp_endpoint
*ep
,
4088 const struct sctp_association
*asoc
,
4089 const sctp_subtype_t type
,
4091 sctp_cmd_seq_t
*commands
)
4093 struct sctp_chunk
*unk_chunk
= arg
;
4094 struct sctp_chunk
*err_chunk
;
4095 sctp_chunkhdr_t
*hdr
;
4097 SCTP_DEBUG_PRINTK("Processing the unknown chunk id %d.\n", type
.chunk
);
4099 if (!sctp_vtag_verify(unk_chunk
, asoc
))
4100 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
4102 /* Make sure that the chunk has a valid length.
4103 * Since we don't know the chunk type, we use a general
4104 * chunkhdr structure to make a comparison.
4106 if (!sctp_chunk_length_valid(unk_chunk
, sizeof(sctp_chunkhdr_t
)))
4107 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
4110 switch (type
.chunk
& SCTP_CID_ACTION_MASK
) {
4111 case SCTP_CID_ACTION_DISCARD
:
4112 /* Discard the packet. */
4113 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
4115 case SCTP_CID_ACTION_DISCARD_ERR
:
4116 /* Generate an ERROR chunk as response. */
4117 hdr
= unk_chunk
->chunk_hdr
;
4118 err_chunk
= sctp_make_op_error(asoc
, unk_chunk
,
4119 SCTP_ERROR_UNKNOWN_CHUNK
, hdr
,
4120 WORD_ROUND(ntohs(hdr
->length
)),
4123 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
4124 SCTP_CHUNK(err_chunk
));
4127 /* Discard the packet. */
4128 sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
4129 return SCTP_DISPOSITION_CONSUME
;
4131 case SCTP_CID_ACTION_SKIP
:
4132 /* Skip the chunk. */
4133 return SCTP_DISPOSITION_DISCARD
;
4135 case SCTP_CID_ACTION_SKIP_ERR
:
4136 /* Generate an ERROR chunk as response. */
4137 hdr
= unk_chunk
->chunk_hdr
;
4138 err_chunk
= sctp_make_op_error(asoc
, unk_chunk
,
4139 SCTP_ERROR_UNKNOWN_CHUNK
, hdr
,
4140 WORD_ROUND(ntohs(hdr
->length
)),
4143 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
4144 SCTP_CHUNK(err_chunk
));
4146 /* Skip the chunk. */
4147 return SCTP_DISPOSITION_CONSUME
;
4153 return SCTP_DISPOSITION_DISCARD
;
4157 * Discard the chunk.
4159 * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2
4160 * [Too numerous to mention...]
4161 * Verification Tag: No verification needed.
4163 * (endpoint, asoc, chunk)
4166 * (asoc, reply_msg, msg_up, timers, counters)
4168 * The return value is the disposition of the chunk.
4170 sctp_disposition_t
sctp_sf_discard_chunk(const struct sctp_endpoint
*ep
,
4171 const struct sctp_association
*asoc
,
4172 const sctp_subtype_t type
,
4174 sctp_cmd_seq_t
*commands
)
4176 struct sctp_chunk
*chunk
= arg
;
4178 /* Make sure that the chunk has a valid length.
4179 * Since we don't know the chunk type, we use a general
4180 * chunkhdr structure to make a comparison.
4182 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
4183 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
4186 SCTP_DEBUG_PRINTK("Chunk %d is discarded\n", type
.chunk
);
4187 return SCTP_DISPOSITION_DISCARD
;
4191 * Discard the whole packet.
4195 * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST
4196 * silently discard the OOTB packet and take no further action.
4198 * Verification Tag: No verification necessary
4201 * (endpoint, asoc, chunk)
4204 * (asoc, reply_msg, msg_up, timers, counters)
4206 * The return value is the disposition of the chunk.
4208 sctp_disposition_t
sctp_sf_pdiscard(const struct sctp_endpoint
*ep
,
4209 const struct sctp_association
*asoc
,
4210 const sctp_subtype_t type
,
4212 sctp_cmd_seq_t
*commands
)
4214 SCTP_INC_STATS(SCTP_MIB_IN_PKT_DISCARDS
);
4215 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
, SCTP_NULL());
4217 return SCTP_DISPOSITION_CONSUME
;
4222 * The other end is violating protocol.
4224 * Section: Not specified
4225 * Verification Tag: Not specified
4227 * (endpoint, asoc, chunk)
4230 * (asoc, reply_msg, msg_up, timers, counters)
4232 * We simply tag the chunk as a violation. The state machine will log
4233 * the violation and continue.
4235 sctp_disposition_t
sctp_sf_violation(const struct sctp_endpoint
*ep
,
4236 const struct sctp_association
*asoc
,
4237 const sctp_subtype_t type
,
4239 sctp_cmd_seq_t
*commands
)
4241 struct sctp_chunk
*chunk
= arg
;
4243 /* Make sure that the chunk has a valid length. */
4244 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
4245 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
4248 return SCTP_DISPOSITION_VIOLATION
;
4252 * Common function to handle a protocol violation.
4254 static sctp_disposition_t
sctp_sf_abort_violation(
4255 const struct sctp_endpoint
*ep
,
4256 const struct sctp_association
*asoc
,
4258 sctp_cmd_seq_t
*commands
,
4259 const __u8
*payload
,
4260 const size_t paylen
)
4262 struct sctp_packet
*packet
= NULL
;
4263 struct sctp_chunk
*chunk
= arg
;
4264 struct sctp_chunk
*abort
= NULL
;
4266 /* SCTP-AUTH, Section 6.3:
4267 * It should be noted that if the receiver wants to tear
4268 * down an association in an authenticated way only, the
4269 * handling of malformed packets should not result in
4270 * tearing down the association.
4272 * This means that if we only want to abort associations
4273 * in an authenticated way (i.e AUTH+ABORT), then we
4274 * can't destroy this association just because the packet
4277 if (sctp_auth_recv_cid(SCTP_CID_ABORT
, asoc
))
4280 /* Make the abort chunk. */
4281 abort
= sctp_make_abort_violation(asoc
, chunk
, payload
, paylen
);
4286 /* Treat INIT-ACK as a special case during COOKIE-WAIT. */
4287 if (chunk
->chunk_hdr
->type
== SCTP_CID_INIT_ACK
&&
4288 !asoc
->peer
.i
.init_tag
) {
4289 sctp_initack_chunk_t
*initack
;
4291 initack
= (sctp_initack_chunk_t
*)chunk
->chunk_hdr
;
4292 if (!sctp_chunk_length_valid(chunk
,
4293 sizeof(sctp_initack_chunk_t
)))
4294 abort
->chunk_hdr
->flags
|= SCTP_CHUNK_FLAG_T
;
4296 unsigned int inittag
;
4298 inittag
= ntohl(initack
->init_hdr
.init_tag
);
4299 sctp_add_cmd_sf(commands
, SCTP_CMD_UPDATE_INITTAG
,
4304 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(abort
));
4305 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
4307 if (asoc
->state
<= SCTP_STATE_COOKIE_ECHOED
) {
4308 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4309 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
4310 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
4311 SCTP_ERROR(ECONNREFUSED
));
4312 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
4313 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION
));
4315 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
4316 SCTP_ERROR(ECONNABORTED
));
4317 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
4318 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION
));
4319 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
4322 packet
= sctp_ootb_pkt_new(asoc
, chunk
);
4327 if (sctp_test_T_bit(abort
))
4328 packet
->vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
4330 abort
->skb
->sk
= ep
->base
.sk
;
4332 sctp_packet_append_chunk(packet
, abort
);
4334 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
4335 SCTP_PACKET(packet
));
4337 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
4340 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
4343 sctp_sf_pdiscard(ep
, asoc
, SCTP_ST_CHUNK(0), arg
, commands
);
4344 return SCTP_DISPOSITION_ABORT
;
4347 sctp_chunk_free(abort
);
4349 return SCTP_DISPOSITION_NOMEM
;
4353 * Handle a protocol violation when the chunk length is invalid.
4354 * "Invalid" length is identified as smaller than the minimal length a
4355 * given chunk can be. For example, a SACK chunk has invalid length
4356 * if its length is set to be smaller than the size of sctp_sack_chunk_t.
4358 * We inform the other end by sending an ABORT with a Protocol Violation
4361 * Section: Not specified
4362 * Verification Tag: Nothing to do
4364 * (endpoint, asoc, chunk)
4367 * (reply_msg, msg_up, counters)
4369 * Generate an ABORT chunk and terminate the association.
4371 static sctp_disposition_t
sctp_sf_violation_chunklen(
4372 const struct sctp_endpoint
*ep
,
4373 const struct sctp_association
*asoc
,
4374 const sctp_subtype_t type
,
4376 sctp_cmd_seq_t
*commands
)
4378 static const char err_str
[]="The following chunk had invalid length:";
4380 return sctp_sf_abort_violation(ep
, asoc
, arg
, commands
, err_str
,
4385 * Handle a protocol violation when the parameter length is invalid.
4386 * If the length is smaller than the minimum length of a given parameter,
4387 * or accumulated length in multi parameters exceeds the end of the chunk,
4388 * the length is considered as invalid.
4390 static sctp_disposition_t
sctp_sf_violation_paramlen(
4391 const struct sctp_endpoint
*ep
,
4392 const struct sctp_association
*asoc
,
4393 const sctp_subtype_t type
,
4394 void *arg
, void *ext
,
4395 sctp_cmd_seq_t
*commands
)
4397 struct sctp_chunk
*chunk
= arg
;
4398 struct sctp_paramhdr
*param
= ext
;
4399 struct sctp_chunk
*abort
= NULL
;
4401 if (sctp_auth_recv_cid(SCTP_CID_ABORT
, asoc
))
4404 /* Make the abort chunk. */
4405 abort
= sctp_make_violation_paramlen(asoc
, chunk
, param
);
4409 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(abort
));
4410 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
4412 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
4413 SCTP_ERROR(ECONNABORTED
));
4414 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
4415 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION
));
4416 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
4417 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
4420 sctp_sf_pdiscard(ep
, asoc
, SCTP_ST_CHUNK(0), arg
, commands
);
4421 return SCTP_DISPOSITION_ABORT
;
4423 return SCTP_DISPOSITION_NOMEM
;
4426 /* Handle a protocol violation when the peer trying to advance the
4427 * cumulative tsn ack to a point beyond the max tsn currently sent.
4429 * We inform the other end by sending an ABORT with a Protocol Violation
4432 static sctp_disposition_t
sctp_sf_violation_ctsn(
4433 const struct sctp_endpoint
*ep
,
4434 const struct sctp_association
*asoc
,
4435 const sctp_subtype_t type
,
4437 sctp_cmd_seq_t
*commands
)
4439 static const char err_str
[]="The cumulative tsn ack beyond the max tsn currently sent:";
4441 return sctp_sf_abort_violation(ep
, asoc
, arg
, commands
, err_str
,
4445 /* Handle protocol violation of an invalid chunk bundling. For example,
4446 * when we have an association and we receive bundled INIT-ACK, or
4447 * SHUDOWN-COMPLETE, our peer is clearly violationg the "MUST NOT bundle"
4448 * statement from the specs. Additionally, there might be an attacker
4449 * on the path and we may not want to continue this communication.
4451 static sctp_disposition_t
sctp_sf_violation_chunk(
4452 const struct sctp_endpoint
*ep
,
4453 const struct sctp_association
*asoc
,
4454 const sctp_subtype_t type
,
4456 sctp_cmd_seq_t
*commands
)
4458 static const char err_str
[]="The following chunk violates protocol:";
4461 return sctp_sf_violation(ep
, asoc
, type
, arg
, commands
);
4463 return sctp_sf_abort_violation(ep
, asoc
, arg
, commands
, err_str
,
4466 /***************************************************************************
4467 * These are the state functions for handling primitive (Section 10) events.
4468 ***************************************************************************/
4470 * sctp_sf_do_prm_asoc
4472 * Section: 10.1 ULP-to-SCTP
4475 * Format: ASSOCIATE(local SCTP instance name, destination transport addr,
4476 * outbound stream count)
4477 * -> association id [,destination transport addr list] [,outbound stream
4480 * This primitive allows the upper layer to initiate an association to a
4481 * specific peer endpoint.
4483 * The peer endpoint shall be specified by one of the transport addresses
4484 * which defines the endpoint (see Section 1.4). If the local SCTP
4485 * instance has not been initialized, the ASSOCIATE is considered an
4487 * [This is not relevant for the kernel implementation since we do all
4488 * initialization at boot time. It we hadn't initialized we wouldn't
4489 * get anywhere near this code.]
4491 * An association id, which is a local handle to the SCTP association,
4492 * will be returned on successful establishment of the association. If
4493 * SCTP is not able to open an SCTP association with the peer endpoint,
4494 * an error is returned.
4495 * [In the kernel implementation, the struct sctp_association needs to
4496 * be created BEFORE causing this primitive to run.]
4498 * Other association parameters may be returned, including the
4499 * complete destination transport addresses of the peer as well as the
4500 * outbound stream count of the local endpoint. One of the transport
4501 * address from the returned destination addresses will be selected by
4502 * the local endpoint as default primary path for sending SCTP packets
4503 * to this peer. The returned "destination transport addr list" can
4504 * be used by the ULP to change the default primary path or to force
4505 * sending a packet to a specific transport address. [All of this
4506 * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING
4509 * Mandatory attributes:
4511 * o local SCTP instance name - obtained from the INITIALIZE operation.
4512 * [This is the argument asoc.]
4513 * o destination transport addr - specified as one of the transport
4514 * addresses of the peer endpoint with which the association is to be
4516 * [This is asoc->peer.active_path.]
4517 * o outbound stream count - the number of outbound streams the ULP
4518 * would like to open towards this peer endpoint.
4519 * [BUG: This is not currently implemented.]
4520 * Optional attributes:
4524 * The return value is a disposition.
4526 sctp_disposition_t
sctp_sf_do_prm_asoc(const struct sctp_endpoint
*ep
,
4527 const struct sctp_association
*asoc
,
4528 const sctp_subtype_t type
,
4530 sctp_cmd_seq_t
*commands
)
4532 struct sctp_chunk
*repl
;
4533 struct sctp_association
* my_asoc
;
4535 /* The comment below says that we enter COOKIE-WAIT AFTER
4536 * sending the INIT, but that doesn't actually work in our
4539 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
4540 SCTP_STATE(SCTP_STATE_COOKIE_WAIT
));
4542 /* RFC 2960 5.1 Normal Establishment of an Association
4544 * A) "A" first sends an INIT chunk to "Z". In the INIT, "A"
4545 * must provide its Verification Tag (Tag_A) in the Initiate
4546 * Tag field. Tag_A SHOULD be a random number in the range of
4547 * 1 to 4294967295 (see 5.3.1 for Tag value selection). ...
4550 repl
= sctp_make_init(asoc
, &asoc
->base
.bind_addr
, GFP_ATOMIC
, 0);
4554 /* Cast away the const modifier, as we want to just
4555 * rerun it through as a sideffect.
4557 my_asoc
= (struct sctp_association
*)asoc
;
4558 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(my_asoc
));
4560 /* Choose transport for INIT. */
4561 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_CHOOSE_TRANSPORT
,
4564 /* After sending the INIT, "A" starts the T1-init timer and
4565 * enters the COOKIE-WAIT state.
4567 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
4568 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
4569 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
4570 return SCTP_DISPOSITION_CONSUME
;
4573 return SCTP_DISPOSITION_NOMEM
;
4577 * Process the SEND primitive.
4579 * Section: 10.1 ULP-to-SCTP
4582 * Format: SEND(association id, buffer address, byte count [,context]
4583 * [,stream id] [,life time] [,destination transport address]
4584 * [,unorder flag] [,no-bundle flag] [,payload protocol-id] )
4587 * This is the main method to send user data via SCTP.
4589 * Mandatory attributes:
4591 * o association id - local handle to the SCTP association
4593 * o buffer address - the location where the user message to be
4594 * transmitted is stored;
4596 * o byte count - The size of the user data in number of bytes;
4598 * Optional attributes:
4600 * o context - an optional 32 bit integer that will be carried in the
4601 * sending failure notification to the ULP if the transportation of
4602 * this User Message fails.
4604 * o stream id - to indicate which stream to send the data on. If not
4605 * specified, stream 0 will be used.
4607 * o life time - specifies the life time of the user data. The user data
4608 * will not be sent by SCTP after the life time expires. This
4609 * parameter can be used to avoid efforts to transmit stale
4610 * user messages. SCTP notifies the ULP if the data cannot be
4611 * initiated to transport (i.e. sent to the destination via SCTP's
4612 * send primitive) within the life time variable. However, the
4613 * user data will be transmitted if SCTP has attempted to transmit a
4614 * chunk before the life time expired.
4616 * o destination transport address - specified as one of the destination
4617 * transport addresses of the peer endpoint to which this packet
4618 * should be sent. Whenever possible, SCTP should use this destination
4619 * transport address for sending the packets, instead of the current
4622 * o unorder flag - this flag, if present, indicates that the user
4623 * would like the data delivered in an unordered fashion to the peer
4624 * (i.e., the U flag is set to 1 on all DATA chunks carrying this
4627 * o no-bundle flag - instructs SCTP not to bundle this user data with
4628 * other outbound DATA chunks. SCTP MAY still bundle even when
4629 * this flag is present, when faced with network congestion.
4631 * o payload protocol-id - A 32 bit unsigned integer that is to be
4632 * passed to the peer indicating the type of payload protocol data
4633 * being transmitted. This value is passed as opaque data by SCTP.
4635 * The return value is the disposition.
4637 sctp_disposition_t
sctp_sf_do_prm_send(const struct sctp_endpoint
*ep
,
4638 const struct sctp_association
*asoc
,
4639 const sctp_subtype_t type
,
4641 sctp_cmd_seq_t
*commands
)
4643 struct sctp_datamsg
*msg
= arg
;
4645 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_MSG
, SCTP_DATAMSG(msg
));
4646 return SCTP_DISPOSITION_CONSUME
;
4650 * Process the SHUTDOWN primitive.
4655 * Format: SHUTDOWN(association id)
4658 * Gracefully closes an association. Any locally queued user data
4659 * will be delivered to the peer. The association will be terminated only
4660 * after the peer acknowledges all the SCTP packets sent. A success code
4661 * will be returned on successful termination of the association. If
4662 * attempting to terminate the association results in a failure, an error
4663 * code shall be returned.
4665 * Mandatory attributes:
4667 * o association id - local handle to the SCTP association
4669 * Optional attributes:
4673 * The return value is the disposition.
4675 sctp_disposition_t
sctp_sf_do_9_2_prm_shutdown(
4676 const struct sctp_endpoint
*ep
,
4677 const struct sctp_association
*asoc
,
4678 const sctp_subtype_t type
,
4680 sctp_cmd_seq_t
*commands
)
4684 /* From 9.2 Shutdown of an Association
4685 * Upon receipt of the SHUTDOWN primitive from its upper
4686 * layer, the endpoint enters SHUTDOWN-PENDING state and
4687 * remains there until all outstanding data has been
4688 * acknowledged by its peer. The endpoint accepts no new data
4689 * from its upper layer, but retransmits data to the far end
4690 * if necessary to fill gaps.
4692 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
4693 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING
));
4695 disposition
= SCTP_DISPOSITION_CONSUME
;
4696 if (sctp_outq_is_empty(&asoc
->outqueue
)) {
4697 disposition
= sctp_sf_do_9_2_start_shutdown(ep
, asoc
, type
,
4704 * Process the ABORT primitive.
4709 * Format: Abort(association id [, cause code])
4712 * Ungracefully closes an association. Any locally queued user data
4713 * will be discarded and an ABORT chunk is sent to the peer. A success code
4714 * will be returned on successful abortion of the association. If
4715 * attempting to abort the association results in a failure, an error
4716 * code shall be returned.
4718 * Mandatory attributes:
4720 * o association id - local handle to the SCTP association
4722 * Optional attributes:
4724 * o cause code - reason of the abort to be passed to the peer
4728 * The return value is the disposition.
4730 sctp_disposition_t
sctp_sf_do_9_1_prm_abort(
4731 const struct sctp_endpoint
*ep
,
4732 const struct sctp_association
*asoc
,
4733 const sctp_subtype_t type
,
4735 sctp_cmd_seq_t
*commands
)
4737 /* From 9.1 Abort of an Association
4738 * Upon receipt of the ABORT primitive from its upper
4739 * layer, the endpoint enters CLOSED state and
4740 * discard all outstanding data has been
4741 * acknowledged by its peer. The endpoint accepts no new data
4742 * from its upper layer, but retransmits data to the far end
4743 * if necessary to fill gaps.
4745 struct sctp_chunk
*abort
= arg
;
4746 sctp_disposition_t retval
;
4748 retval
= SCTP_DISPOSITION_CONSUME
;
4750 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(abort
));
4752 /* Even if we can't send the ABORT due to low memory delete the
4753 * TCB. This is a departure from our typical NOMEM handling.
4756 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
4757 SCTP_ERROR(ECONNABORTED
));
4758 /* Delete the established association. */
4759 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
4760 SCTP_PERR(SCTP_ERROR_USER_ABORT
));
4762 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
4763 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
4768 /* We tried an illegal operation on an association which is closed. */
4769 sctp_disposition_t
sctp_sf_error_closed(const struct sctp_endpoint
*ep
,
4770 const struct sctp_association
*asoc
,
4771 const sctp_subtype_t type
,
4773 sctp_cmd_seq_t
*commands
)
4775 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_ERROR
, SCTP_ERROR(-EINVAL
));
4776 return SCTP_DISPOSITION_CONSUME
;
4779 /* We tried an illegal operation on an association which is shutting
4782 sctp_disposition_t
sctp_sf_error_shutdown(const struct sctp_endpoint
*ep
,
4783 const struct sctp_association
*asoc
,
4784 const sctp_subtype_t type
,
4786 sctp_cmd_seq_t
*commands
)
4788 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_ERROR
,
4789 SCTP_ERROR(-ESHUTDOWN
));
4790 return SCTP_DISPOSITION_CONSUME
;
4794 * sctp_cookie_wait_prm_shutdown
4796 * Section: 4 Note: 2
4801 * The RFC does not explicitly address this issue, but is the route through the
4802 * state table when someone issues a shutdown while in COOKIE_WAIT state.
4807 sctp_disposition_t
sctp_sf_cookie_wait_prm_shutdown(
4808 const struct sctp_endpoint
*ep
,
4809 const struct sctp_association
*asoc
,
4810 const sctp_subtype_t type
,
4812 sctp_cmd_seq_t
*commands
)
4814 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4815 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
4817 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
4818 SCTP_STATE(SCTP_STATE_CLOSED
));
4820 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS
);
4822 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
4824 return SCTP_DISPOSITION_DELETE_TCB
;
4828 * sctp_cookie_echoed_prm_shutdown
4830 * Section: 4 Note: 2
4835 * The RFC does not explcitly address this issue, but is the route through the
4836 * state table when someone issues a shutdown while in COOKIE_ECHOED state.
4841 sctp_disposition_t
sctp_sf_cookie_echoed_prm_shutdown(
4842 const struct sctp_endpoint
*ep
,
4843 const struct sctp_association
*asoc
,
4844 const sctp_subtype_t type
,
4845 void *arg
, sctp_cmd_seq_t
*commands
)
4847 /* There is a single T1 timer, so we should be able to use
4848 * common function with the COOKIE-WAIT state.
4850 return sctp_sf_cookie_wait_prm_shutdown(ep
, asoc
, type
, arg
, commands
);
4854 * sctp_sf_cookie_wait_prm_abort
4856 * Section: 4 Note: 2
4861 * The RFC does not explicitly address this issue, but is the route through the
4862 * state table when someone issues an abort while in COOKIE_WAIT state.
4867 sctp_disposition_t
sctp_sf_cookie_wait_prm_abort(
4868 const struct sctp_endpoint
*ep
,
4869 const struct sctp_association
*asoc
,
4870 const sctp_subtype_t type
,
4872 sctp_cmd_seq_t
*commands
)
4874 struct sctp_chunk
*abort
= arg
;
4875 sctp_disposition_t retval
;
4877 /* Stop T1-init timer */
4878 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4879 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
4880 retval
= SCTP_DISPOSITION_CONSUME
;
4882 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(abort
));
4884 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
4885 SCTP_STATE(SCTP_STATE_CLOSED
));
4887 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
4889 /* Even if we can't send the ABORT due to low memory delete the
4890 * TCB. This is a departure from our typical NOMEM handling.
4893 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
4894 SCTP_ERROR(ECONNREFUSED
));
4895 /* Delete the established association. */
4896 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
4897 SCTP_PERR(SCTP_ERROR_USER_ABORT
));
4903 * sctp_sf_cookie_echoed_prm_abort
4905 * Section: 4 Note: 3
4910 * The RFC does not explcitly address this issue, but is the route through the
4911 * state table when someone issues an abort while in COOKIE_ECHOED state.
4916 sctp_disposition_t
sctp_sf_cookie_echoed_prm_abort(
4917 const struct sctp_endpoint
*ep
,
4918 const struct sctp_association
*asoc
,
4919 const sctp_subtype_t type
,
4921 sctp_cmd_seq_t
*commands
)
4923 /* There is a single T1 timer, so we should be able to use
4924 * common function with the COOKIE-WAIT state.
4926 return sctp_sf_cookie_wait_prm_abort(ep
, asoc
, type
, arg
, commands
);
4930 * sctp_sf_shutdown_pending_prm_abort
4935 * The RFC does not explicitly address this issue, but is the route through the
4936 * state table when someone issues an abort while in SHUTDOWN-PENDING state.
4941 sctp_disposition_t
sctp_sf_shutdown_pending_prm_abort(
4942 const struct sctp_endpoint
*ep
,
4943 const struct sctp_association
*asoc
,
4944 const sctp_subtype_t type
,
4946 sctp_cmd_seq_t
*commands
)
4948 /* Stop the T5-shutdown guard timer. */
4949 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4950 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
4952 return sctp_sf_do_9_1_prm_abort(ep
, asoc
, type
, arg
, commands
);
4956 * sctp_sf_shutdown_sent_prm_abort
4961 * The RFC does not explicitly address this issue, but is the route through the
4962 * state table when someone issues an abort while in SHUTDOWN-SENT state.
4967 sctp_disposition_t
sctp_sf_shutdown_sent_prm_abort(
4968 const struct sctp_endpoint
*ep
,
4969 const struct sctp_association
*asoc
,
4970 const sctp_subtype_t type
,
4972 sctp_cmd_seq_t
*commands
)
4974 /* Stop the T2-shutdown timer. */
4975 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4976 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
4978 /* Stop the T5-shutdown guard timer. */
4979 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4980 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
4982 return sctp_sf_do_9_1_prm_abort(ep
, asoc
, type
, arg
, commands
);
4986 * sctp_sf_cookie_echoed_prm_abort
4991 * The RFC does not explcitly address this issue, but is the route through the
4992 * state table when someone issues an abort while in COOKIE_ECHOED state.
4997 sctp_disposition_t
sctp_sf_shutdown_ack_sent_prm_abort(
4998 const struct sctp_endpoint
*ep
,
4999 const struct sctp_association
*asoc
,
5000 const sctp_subtype_t type
,
5002 sctp_cmd_seq_t
*commands
)
5004 /* The same T2 timer, so we should be able to use
5005 * common function with the SHUTDOWN-SENT state.
5007 return sctp_sf_shutdown_sent_prm_abort(ep
, asoc
, type
, arg
, commands
);
5011 * Process the REQUESTHEARTBEAT primitive
5014 * J) Request Heartbeat
5016 * Format: REQUESTHEARTBEAT(association id, destination transport address)
5020 * Instructs the local endpoint to perform a HeartBeat on the specified
5021 * destination transport address of the given association. The returned
5022 * result should indicate whether the transmission of the HEARTBEAT
5023 * chunk to the destination address is successful.
5025 * Mandatory attributes:
5027 * o association id - local handle to the SCTP association
5029 * o destination transport address - the transport address of the
5030 * association on which a heartbeat should be issued.
5032 sctp_disposition_t
sctp_sf_do_prm_requestheartbeat(
5033 const struct sctp_endpoint
*ep
,
5034 const struct sctp_association
*asoc
,
5035 const sctp_subtype_t type
,
5037 sctp_cmd_seq_t
*commands
)
5039 if (SCTP_DISPOSITION_NOMEM
== sctp_sf_heartbeat(ep
, asoc
, type
,
5040 (struct sctp_transport
*)arg
, commands
))
5041 return SCTP_DISPOSITION_NOMEM
;
5044 * RFC 2960 (bis), section 8.3
5046 * D) Request an on-demand HEARTBEAT on a specific destination
5047 * transport address of a given association.
5049 * The endpoint should increment the respective error counter of
5050 * the destination transport address each time a HEARTBEAT is sent
5051 * to that address and not acknowledged within one RTO.
5054 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSPORT_HB_SENT
,
5055 SCTP_TRANSPORT(arg
));
5056 return SCTP_DISPOSITION_CONSUME
;
5060 * ADDIP Section 4.1 ASCONF Chunk Procedures
5061 * When an endpoint has an ASCONF signaled change to be sent to the
5062 * remote endpoint it should do A1 to A9
5064 sctp_disposition_t
sctp_sf_do_prm_asconf(const struct sctp_endpoint
*ep
,
5065 const struct sctp_association
*asoc
,
5066 const sctp_subtype_t type
,
5068 sctp_cmd_seq_t
*commands
)
5070 struct sctp_chunk
*chunk
= arg
;
5072 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T4
, SCTP_CHUNK(chunk
));
5073 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
5074 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
5075 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(chunk
));
5076 return SCTP_DISPOSITION_CONSUME
;
5080 * Ignore the primitive event
5082 * The return value is the disposition of the primitive.
5084 sctp_disposition_t
sctp_sf_ignore_primitive(
5085 const struct sctp_endpoint
*ep
,
5086 const struct sctp_association
*asoc
,
5087 const sctp_subtype_t type
,
5089 sctp_cmd_seq_t
*commands
)
5091 SCTP_DEBUG_PRINTK("Primitive type %d is ignored.\n", type
.primitive
);
5092 return SCTP_DISPOSITION_DISCARD
;
5095 /***************************************************************************
5096 * These are the state functions for the OTHER events.
5097 ***************************************************************************/
5100 * When the SCTP stack has no more user data to send or retransmit, this
5101 * notification is given to the user. Also, at the time when a user app
5102 * subscribes to this event, if there is no data to be sent or
5103 * retransmit, the stack will immediately send up this notification.
5105 sctp_disposition_t
sctp_sf_do_no_pending_tsn(
5106 const struct sctp_endpoint
*ep
,
5107 const struct sctp_association
*asoc
,
5108 const sctp_subtype_t type
,
5110 sctp_cmd_seq_t
*commands
)
5112 struct sctp_ulpevent
*event
;
5114 event
= sctp_ulpevent_make_sender_dry_event(asoc
, GFP_ATOMIC
);
5116 return SCTP_DISPOSITION_NOMEM
;
5118 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(event
));
5120 return SCTP_DISPOSITION_CONSUME
;
5124 * Start the shutdown negotiation.
5127 * Once all its outstanding data has been acknowledged, the endpoint
5128 * shall send a SHUTDOWN chunk to its peer including in the Cumulative
5129 * TSN Ack field the last sequential TSN it has received from the peer.
5130 * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT
5131 * state. If the timer expires, the endpoint must re-send the SHUTDOWN
5132 * with the updated last sequential TSN received from its peer.
5134 * The return value is the disposition.
5136 sctp_disposition_t
sctp_sf_do_9_2_start_shutdown(
5137 const struct sctp_endpoint
*ep
,
5138 const struct sctp_association
*asoc
,
5139 const sctp_subtype_t type
,
5141 sctp_cmd_seq_t
*commands
)
5143 struct sctp_chunk
*reply
;
5145 /* Once all its outstanding data has been acknowledged, the
5146 * endpoint shall send a SHUTDOWN chunk to its peer including
5147 * in the Cumulative TSN Ack field the last sequential TSN it
5148 * has received from the peer.
5150 reply
= sctp_make_shutdown(asoc
, NULL
);
5154 /* Set the transport for the SHUTDOWN chunk and the timeout for the
5155 * T2-shutdown timer.
5157 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T2
, SCTP_CHUNK(reply
));
5159 /* It shall then start the T2-shutdown timer */
5160 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
5161 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
5163 /* RFC 4960 Section 9.2
5164 * The sender of the SHUTDOWN MAY also start an overall guard timer
5165 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5167 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
5168 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
5170 if (asoc
->autoclose
)
5171 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
5172 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
5174 /* and enter the SHUTDOWN-SENT state. */
5175 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
5176 SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT
));
5178 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5180 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
5183 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_STOP
, SCTP_NULL());
5185 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
5187 return SCTP_DISPOSITION_CONSUME
;
5190 return SCTP_DISPOSITION_NOMEM
;
5194 * Generate a SHUTDOWN ACK now that everything is SACK'd.
5198 * If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5199 * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own,
5200 * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the
5201 * endpoint must re-send the SHUTDOWN ACK.
5203 * The return value is the disposition.
5205 sctp_disposition_t
sctp_sf_do_9_2_shutdown_ack(
5206 const struct sctp_endpoint
*ep
,
5207 const struct sctp_association
*asoc
,
5208 const sctp_subtype_t type
,
5210 sctp_cmd_seq_t
*commands
)
5212 struct sctp_chunk
*chunk
= (struct sctp_chunk
*) arg
;
5213 struct sctp_chunk
*reply
;
5215 /* There are 2 ways of getting here:
5216 * 1) called in response to a SHUTDOWN chunk
5217 * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued.
5219 * For the case (2), the arg parameter is set to NULL. We need
5220 * to check that we have a chunk before accessing it's fields.
5223 if (!sctp_vtag_verify(chunk
, asoc
))
5224 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
5226 /* Make sure that the SHUTDOWN chunk has a valid length. */
5227 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_shutdown_chunk_t
)))
5228 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
5232 /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5233 * shall send a SHUTDOWN ACK ...
5235 reply
= sctp_make_shutdown_ack(asoc
, chunk
);
5239 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
5240 * the T2-shutdown timer.
5242 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T2
, SCTP_CHUNK(reply
));
5244 /* and start/restart a T2-shutdown timer of its own, */
5245 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
5246 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
5248 if (asoc
->autoclose
)
5249 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
5250 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
5252 /* Enter the SHUTDOWN-ACK-SENT state. */
5253 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
5254 SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT
));
5256 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5258 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
5261 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_STOP
, SCTP_NULL());
5263 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
5265 return SCTP_DISPOSITION_CONSUME
;
5268 return SCTP_DISPOSITION_NOMEM
;
5272 * Ignore the event defined as other
5274 * The return value is the disposition of the event.
5276 sctp_disposition_t
sctp_sf_ignore_other(const struct sctp_endpoint
*ep
,
5277 const struct sctp_association
*asoc
,
5278 const sctp_subtype_t type
,
5280 sctp_cmd_seq_t
*commands
)
5282 SCTP_DEBUG_PRINTK("The event other type %d is ignored\n", type
.other
);
5283 return SCTP_DISPOSITION_DISCARD
;
5286 /************************************************************
5287 * These are the state functions for handling timeout events.
5288 ************************************************************/
5293 * Section: 6.3.3 Handle T3-rtx Expiration
5295 * Whenever the retransmission timer T3-rtx expires for a destination
5296 * address, do the following:
5299 * The return value is the disposition of the chunk.
5301 sctp_disposition_t
sctp_sf_do_6_3_3_rtx(const struct sctp_endpoint
*ep
,
5302 const struct sctp_association
*asoc
,
5303 const sctp_subtype_t type
,
5305 sctp_cmd_seq_t
*commands
)
5307 struct sctp_transport
*transport
= arg
;
5309 SCTP_INC_STATS(SCTP_MIB_T3_RTX_EXPIREDS
);
5311 if (asoc
->overall_error_count
>= asoc
->max_retrans
) {
5312 if (asoc
->state
== SCTP_STATE_SHUTDOWN_PENDING
) {
5314 * We are here likely because the receiver had its rwnd
5315 * closed for a while and we have not been able to
5316 * transmit the locally queued data within the maximum
5317 * retransmission attempts limit. Start the T5
5318 * shutdown guard timer to give the receiver one last
5319 * chance and some additional time to recover before
5322 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START_ONCE
,
5323 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
5325 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5326 SCTP_ERROR(ETIMEDOUT
));
5327 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5328 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
5329 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5330 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
5331 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
5332 return SCTP_DISPOSITION_DELETE_TCB
;
5336 /* E1) For the destination address for which the timer
5337 * expires, adjust its ssthresh with rules defined in Section
5338 * 7.2.3 and set the cwnd <- MTU.
5341 /* E2) For the destination address for which the timer
5342 * expires, set RTO <- RTO * 2 ("back off the timer"). The
5343 * maximum value discussed in rule C7 above (RTO.max) may be
5344 * used to provide an upper bound to this doubling operation.
5347 /* E3) Determine how many of the earliest (i.e., lowest TSN)
5348 * outstanding DATA chunks for the address for which the
5349 * T3-rtx has expired will fit into a single packet, subject
5350 * to the MTU constraint for the path corresponding to the
5351 * destination transport address to which the retransmission
5352 * is being sent (this may be different from the address for
5353 * which the timer expires [see Section 6.4]). Call this
5354 * value K. Bundle and retransmit those K DATA chunks in a
5355 * single packet to the destination endpoint.
5357 * Note: Any DATA chunks that were sent to the address for
5358 * which the T3-rtx timer expired but did not fit in one MTU
5359 * (rule E3 above), should be marked for retransmission and
5360 * sent as soon as cwnd allows (normally when a SACK arrives).
5363 /* Do some failure management (Section 8.2). */
5364 sctp_add_cmd_sf(commands
, SCTP_CMD_STRIKE
, SCTP_TRANSPORT(transport
));
5366 /* NB: Rules E4 and F1 are implicit in R1. */
5367 sctp_add_cmd_sf(commands
, SCTP_CMD_RETRAN
, SCTP_TRANSPORT(transport
));
5369 return SCTP_DISPOSITION_CONSUME
;
5373 * Generate delayed SACK on timeout
5375 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
5377 * The guidelines on delayed acknowledgement algorithm specified in
5378 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
5379 * acknowledgement SHOULD be generated for at least every second packet
5380 * (not every second DATA chunk) received, and SHOULD be generated
5381 * within 200 ms of the arrival of any unacknowledged DATA chunk. In
5382 * some situations it may be beneficial for an SCTP transmitter to be
5383 * more conservative than the algorithms detailed in this document
5384 * allow. However, an SCTP transmitter MUST NOT be more aggressive than
5385 * the following algorithms allow.
5387 sctp_disposition_t
sctp_sf_do_6_2_sack(const struct sctp_endpoint
*ep
,
5388 const struct sctp_association
*asoc
,
5389 const sctp_subtype_t type
,
5391 sctp_cmd_seq_t
*commands
)
5393 SCTP_INC_STATS(SCTP_MIB_DELAY_SACK_EXPIREDS
);
5394 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_FORCE());
5395 return SCTP_DISPOSITION_CONSUME
;
5399 * sctp_sf_t1_init_timer_expire
5401 * Section: 4 Note: 2
5406 * RFC 2960 Section 4 Notes
5407 * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT
5408 * and re-start the T1-init timer without changing state. This MUST
5409 * be repeated up to 'Max.Init.Retransmits' times. After that, the
5410 * endpoint MUST abort the initialization process and report the
5411 * error to SCTP user.
5417 sctp_disposition_t
sctp_sf_t1_init_timer_expire(const struct sctp_endpoint
*ep
,
5418 const struct sctp_association
*asoc
,
5419 const sctp_subtype_t type
,
5421 sctp_cmd_seq_t
*commands
)
5423 struct sctp_chunk
*repl
= NULL
;
5424 struct sctp_bind_addr
*bp
;
5425 int attempts
= asoc
->init_err_counter
+ 1;
5427 SCTP_DEBUG_PRINTK("Timer T1 expired (INIT).\n");
5428 SCTP_INC_STATS(SCTP_MIB_T1_INIT_EXPIREDS
);
5430 if (attempts
<= asoc
->max_init_attempts
) {
5431 bp
= (struct sctp_bind_addr
*) &asoc
->base
.bind_addr
;
5432 repl
= sctp_make_init(asoc
, bp
, GFP_ATOMIC
, 0);
5434 return SCTP_DISPOSITION_NOMEM
;
5436 /* Choose transport for INIT. */
5437 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_CHOOSE_TRANSPORT
,
5440 /* Issue a sideeffect to do the needed accounting. */
5441 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_RESTART
,
5442 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
5444 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
5446 SCTP_DEBUG_PRINTK("Giving up on INIT, attempts: %d"
5447 " max_init_attempts: %d\n",
5448 attempts
, asoc
->max_init_attempts
);
5449 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5450 SCTP_ERROR(ETIMEDOUT
));
5451 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
5452 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5453 return SCTP_DISPOSITION_DELETE_TCB
;
5456 return SCTP_DISPOSITION_CONSUME
;
5460 * sctp_sf_t1_cookie_timer_expire
5462 * Section: 4 Note: 2
5467 * RFC 2960 Section 4 Notes
5468 * 3) If the T1-cookie timer expires, the endpoint MUST retransmit
5469 * COOKIE ECHO and re-start the T1-cookie timer without changing
5470 * state. This MUST be repeated up to 'Max.Init.Retransmits' times.
5471 * After that, the endpoint MUST abort the initialization process and
5472 * report the error to SCTP user.
5478 sctp_disposition_t
sctp_sf_t1_cookie_timer_expire(const struct sctp_endpoint
*ep
,
5479 const struct sctp_association
*asoc
,
5480 const sctp_subtype_t type
,
5482 sctp_cmd_seq_t
*commands
)
5484 struct sctp_chunk
*repl
= NULL
;
5485 int attempts
= asoc
->init_err_counter
+ 1;
5487 SCTP_DEBUG_PRINTK("Timer T1 expired (COOKIE-ECHO).\n");
5488 SCTP_INC_STATS(SCTP_MIB_T1_COOKIE_EXPIREDS
);
5490 if (attempts
<= asoc
->max_init_attempts
) {
5491 repl
= sctp_make_cookie_echo(asoc
, NULL
);
5493 return SCTP_DISPOSITION_NOMEM
;
5495 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_CHOOSE_TRANSPORT
,
5497 /* Issue a sideeffect to do the needed accounting. */
5498 sctp_add_cmd_sf(commands
, SCTP_CMD_COOKIEECHO_RESTART
,
5499 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
5501 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
5503 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5504 SCTP_ERROR(ETIMEDOUT
));
5505 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
5506 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5507 return SCTP_DISPOSITION_DELETE_TCB
;
5510 return SCTP_DISPOSITION_CONSUME
;
5513 /* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN
5514 * with the updated last sequential TSN received from its peer.
5516 * An endpoint should limit the number of retransmissions of the
5517 * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'.
5518 * If this threshold is exceeded the endpoint should destroy the TCB and
5519 * MUST report the peer endpoint unreachable to the upper layer (and
5520 * thus the association enters the CLOSED state). The reception of any
5521 * packet from its peer (i.e. as the peer sends all of its queued DATA
5522 * chunks) should clear the endpoint's retransmission count and restart
5523 * the T2-Shutdown timer, giving its peer ample opportunity to transmit
5524 * all of its queued DATA chunks that have not yet been sent.
5526 sctp_disposition_t
sctp_sf_t2_timer_expire(const struct sctp_endpoint
*ep
,
5527 const struct sctp_association
*asoc
,
5528 const sctp_subtype_t type
,
5530 sctp_cmd_seq_t
*commands
)
5532 struct sctp_chunk
*reply
= NULL
;
5534 SCTP_DEBUG_PRINTK("Timer T2 expired.\n");
5535 SCTP_INC_STATS(SCTP_MIB_T2_SHUTDOWN_EXPIREDS
);
5537 ((struct sctp_association
*)asoc
)->shutdown_retries
++;
5539 if (asoc
->overall_error_count
>= asoc
->max_retrans
) {
5540 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5541 SCTP_ERROR(ETIMEDOUT
));
5542 /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5543 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
5544 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5545 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
5546 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
5547 return SCTP_DISPOSITION_DELETE_TCB
;
5550 switch (asoc
->state
) {
5551 case SCTP_STATE_SHUTDOWN_SENT
:
5552 reply
= sctp_make_shutdown(asoc
, NULL
);
5555 case SCTP_STATE_SHUTDOWN_ACK_SENT
:
5556 reply
= sctp_make_shutdown_ack(asoc
, NULL
);
5567 /* Do some failure management (Section 8.2).
5568 * If we remove the transport an SHUTDOWN was last sent to, don't
5569 * do failure management.
5571 if (asoc
->shutdown_last_sent_to
)
5572 sctp_add_cmd_sf(commands
, SCTP_CMD_STRIKE
,
5573 SCTP_TRANSPORT(asoc
->shutdown_last_sent_to
));
5575 /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for
5576 * the T2-shutdown timer.
5578 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T2
, SCTP_CHUNK(reply
));
5580 /* Restart the T2-shutdown timer. */
5581 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
5582 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
5583 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
5584 return SCTP_DISPOSITION_CONSUME
;
5587 return SCTP_DISPOSITION_NOMEM
;
5591 * ADDIP Section 4.1 ASCONF CHunk Procedures
5592 * If the T4 RTO timer expires the endpoint should do B1 to B5
5594 sctp_disposition_t
sctp_sf_t4_timer_expire(
5595 const struct sctp_endpoint
*ep
,
5596 const struct sctp_association
*asoc
,
5597 const sctp_subtype_t type
,
5599 sctp_cmd_seq_t
*commands
)
5601 struct sctp_chunk
*chunk
= asoc
->addip_last_asconf
;
5602 struct sctp_transport
*transport
= chunk
->transport
;
5604 SCTP_INC_STATS(SCTP_MIB_T4_RTO_EXPIREDS
);
5606 /* ADDIP 4.1 B1) Increment the error counters and perform path failure
5607 * detection on the appropriate destination address as defined in
5608 * RFC2960 [5] section 8.1 and 8.2.
5611 sctp_add_cmd_sf(commands
, SCTP_CMD_STRIKE
,
5612 SCTP_TRANSPORT(transport
));
5614 /* Reconfig T4 timer and transport. */
5615 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T4
, SCTP_CHUNK(chunk
));
5617 /* ADDIP 4.1 B2) Increment the association error counters and perform
5618 * endpoint failure detection on the association as defined in
5619 * RFC2960 [5] section 8.1 and 8.2.
5620 * association error counter is incremented in SCTP_CMD_STRIKE.
5622 if (asoc
->overall_error_count
>= asoc
->max_retrans
) {
5623 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
5624 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
5625 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5626 SCTP_ERROR(ETIMEDOUT
));
5627 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
5628 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5629 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
5630 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
5631 return SCTP_DISPOSITION_ABORT
;
5634 /* ADDIP 4.1 B3) Back-off the destination address RTO value to which
5635 * the ASCONF chunk was sent by doubling the RTO timer value.
5636 * This is done in SCTP_CMD_STRIKE.
5639 /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible
5640 * choose an alternate destination address (please refer to RFC2960
5641 * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this
5642 * chunk, it MUST be the same (including its serial number) as the last
5645 sctp_chunk_hold(asoc
->addip_last_asconf
);
5646 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
5647 SCTP_CHUNK(asoc
->addip_last_asconf
));
5649 /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different
5650 * destination is selected, then the RTO used will be that of the new
5651 * destination address.
5653 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
5654 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
5656 return SCTP_DISPOSITION_CONSUME
;
5659 /* sctpimpguide-05 Section 2.12.2
5660 * The sender of the SHUTDOWN MAY also start an overall guard timer
5661 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5662 * At the expiration of this timer the sender SHOULD abort the association
5663 * by sending an ABORT chunk.
5665 sctp_disposition_t
sctp_sf_t5_timer_expire(const struct sctp_endpoint
*ep
,
5666 const struct sctp_association
*asoc
,
5667 const sctp_subtype_t type
,
5669 sctp_cmd_seq_t
*commands
)
5671 struct sctp_chunk
*reply
= NULL
;
5673 SCTP_DEBUG_PRINTK("Timer T5 expired.\n");
5674 SCTP_INC_STATS(SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS
);
5676 reply
= sctp_make_abort(asoc
, NULL
, 0);
5680 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
5681 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5682 SCTP_ERROR(ETIMEDOUT
));
5683 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
5684 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5686 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
5687 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
5689 return SCTP_DISPOSITION_DELETE_TCB
;
5691 return SCTP_DISPOSITION_NOMEM
;
5694 /* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires,
5695 * the association is automatically closed by starting the shutdown process.
5696 * The work that needs to be done is same as when SHUTDOWN is initiated by
5697 * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown().
5699 sctp_disposition_t
sctp_sf_autoclose_timer_expire(
5700 const struct sctp_endpoint
*ep
,
5701 const struct sctp_association
*asoc
,
5702 const sctp_subtype_t type
,
5704 sctp_cmd_seq_t
*commands
)
5708 SCTP_INC_STATS(SCTP_MIB_AUTOCLOSE_EXPIREDS
);
5710 /* From 9.2 Shutdown of an Association
5711 * Upon receipt of the SHUTDOWN primitive from its upper
5712 * layer, the endpoint enters SHUTDOWN-PENDING state and
5713 * remains there until all outstanding data has been
5714 * acknowledged by its peer. The endpoint accepts no new data
5715 * from its upper layer, but retransmits data to the far end
5716 * if necessary to fill gaps.
5718 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
5719 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING
));
5721 disposition
= SCTP_DISPOSITION_CONSUME
;
5722 if (sctp_outq_is_empty(&asoc
->outqueue
)) {
5723 disposition
= sctp_sf_do_9_2_start_shutdown(ep
, asoc
, type
,
5729 /*****************************************************************************
5730 * These are sa state functions which could apply to all types of events.
5731 ****************************************************************************/
5734 * This table entry is not implemented.
5737 * (endpoint, asoc, chunk)
5739 * The return value is the disposition of the chunk.
5741 sctp_disposition_t
sctp_sf_not_impl(const struct sctp_endpoint
*ep
,
5742 const struct sctp_association
*asoc
,
5743 const sctp_subtype_t type
,
5745 sctp_cmd_seq_t
*commands
)
5747 return SCTP_DISPOSITION_NOT_IMPL
;
5751 * This table entry represents a bug.
5754 * (endpoint, asoc, chunk)
5756 * The return value is the disposition of the chunk.
5758 sctp_disposition_t
sctp_sf_bug(const struct sctp_endpoint
*ep
,
5759 const struct sctp_association
*asoc
,
5760 const sctp_subtype_t type
,
5762 sctp_cmd_seq_t
*commands
)
5764 return SCTP_DISPOSITION_BUG
;
5768 * This table entry represents the firing of a timer in the wrong state.
5769 * Since timer deletion cannot be guaranteed a timer 'may' end up firing
5770 * when the association is in the wrong state. This event should
5771 * be ignored, so as to prevent any rearming of the timer.
5774 * (endpoint, asoc, chunk)
5776 * The return value is the disposition of the chunk.
5778 sctp_disposition_t
sctp_sf_timer_ignore(const struct sctp_endpoint
*ep
,
5779 const struct sctp_association
*asoc
,
5780 const sctp_subtype_t type
,
5782 sctp_cmd_seq_t
*commands
)
5784 SCTP_DEBUG_PRINTK("Timer %d ignored.\n", type
.chunk
);
5785 return SCTP_DISPOSITION_CONSUME
;
5788 /********************************************************************
5789 * 2nd Level Abstractions
5790 ********************************************************************/
5792 /* Pull the SACK chunk based on the SACK header. */
5793 static struct sctp_sackhdr
*sctp_sm_pull_sack(struct sctp_chunk
*chunk
)
5795 struct sctp_sackhdr
*sack
;
5800 /* Protect ourselves from reading too far into
5801 * the skb from a bogus sender.
5803 sack
= (struct sctp_sackhdr
*) chunk
->skb
->data
;
5805 num_blocks
= ntohs(sack
->num_gap_ack_blocks
);
5806 num_dup_tsns
= ntohs(sack
->num_dup_tsns
);
5807 len
= sizeof(struct sctp_sackhdr
);
5808 len
+= (num_blocks
+ num_dup_tsns
) * sizeof(__u32
);
5809 if (len
> chunk
->skb
->len
)
5812 skb_pull(chunk
->skb
, len
);
5817 /* Create an ABORT packet to be sent as a response, with the specified
5820 static struct sctp_packet
*sctp_abort_pkt_new(const struct sctp_endpoint
*ep
,
5821 const struct sctp_association
*asoc
,
5822 struct sctp_chunk
*chunk
,
5823 const void *payload
,
5826 struct sctp_packet
*packet
;
5827 struct sctp_chunk
*abort
;
5829 packet
= sctp_ootb_pkt_new(asoc
, chunk
);
5833 * The T bit will be set if the asoc is NULL.
5835 abort
= sctp_make_abort(asoc
, chunk
, paylen
);
5837 sctp_ootb_pkt_free(packet
);
5841 /* Reflect vtag if T-Bit is set */
5842 if (sctp_test_T_bit(abort
))
5843 packet
->vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
5845 /* Add specified error causes, i.e., payload, to the
5848 sctp_addto_chunk(abort
, paylen
, payload
);
5850 /* Set the skb to the belonging sock for accounting. */
5851 abort
->skb
->sk
= ep
->base
.sk
;
5853 sctp_packet_append_chunk(packet
, abort
);
5860 /* Allocate a packet for responding in the OOTB conditions. */
5861 static struct sctp_packet
*sctp_ootb_pkt_new(const struct sctp_association
*asoc
,
5862 const struct sctp_chunk
*chunk
)
5864 struct sctp_packet
*packet
;
5865 struct sctp_transport
*transport
;
5870 /* Get the source and destination port from the inbound packet. */
5871 sport
= ntohs(chunk
->sctp_hdr
->dest
);
5872 dport
= ntohs(chunk
->sctp_hdr
->source
);
5874 /* The V-tag is going to be the same as the inbound packet if no
5875 * association exists, otherwise, use the peer's vtag.
5878 /* Special case the INIT-ACK as there is no peer's vtag
5881 switch(chunk
->chunk_hdr
->type
) {
5882 case SCTP_CID_INIT_ACK
:
5884 sctp_initack_chunk_t
*initack
;
5886 initack
= (sctp_initack_chunk_t
*)chunk
->chunk_hdr
;
5887 vtag
= ntohl(initack
->init_hdr
.init_tag
);
5891 vtag
= asoc
->peer
.i
.init_tag
;
5895 /* Special case the INIT and stale COOKIE_ECHO as there is no
5898 switch(chunk
->chunk_hdr
->type
) {
5901 sctp_init_chunk_t
*init
;
5903 init
= (sctp_init_chunk_t
*)chunk
->chunk_hdr
;
5904 vtag
= ntohl(init
->init_hdr
.init_tag
);
5908 vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
5913 /* Make a transport for the bucket, Eliza... */
5914 transport
= sctp_transport_new(sctp_source(chunk
), GFP_ATOMIC
);
5918 /* Cache a route for the transport with the chunk's destination as
5919 * the source address.
5921 sctp_transport_route(transport
, (union sctp_addr
*)&chunk
->dest
,
5922 sctp_sk(sctp_get_ctl_sock()));
5924 packet
= sctp_packet_init(&transport
->packet
, transport
, sport
, dport
);
5925 packet
= sctp_packet_config(packet
, vtag
, 0);
5933 /* Free the packet allocated earlier for responding in the OOTB condition. */
5934 void sctp_ootb_pkt_free(struct sctp_packet
*packet
)
5936 sctp_transport_free(packet
->transport
);
5939 /* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */
5940 static void sctp_send_stale_cookie_err(const struct sctp_endpoint
*ep
,
5941 const struct sctp_association
*asoc
,
5942 const struct sctp_chunk
*chunk
,
5943 sctp_cmd_seq_t
*commands
,
5944 struct sctp_chunk
*err_chunk
)
5946 struct sctp_packet
*packet
;
5949 packet
= sctp_ootb_pkt_new(asoc
, chunk
);
5951 struct sctp_signed_cookie
*cookie
;
5953 /* Override the OOTB vtag from the cookie. */
5954 cookie
= chunk
->subh
.cookie_hdr
;
5955 packet
->vtag
= cookie
->c
.peer_vtag
;
5957 /* Set the skb to the belonging sock for accounting. */
5958 err_chunk
->skb
->sk
= ep
->base
.sk
;
5959 sctp_packet_append_chunk(packet
, err_chunk
);
5960 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
5961 SCTP_PACKET(packet
));
5962 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
5964 sctp_chunk_free (err_chunk
);
5969 /* Process a data chunk */
5970 static int sctp_eat_data(const struct sctp_association
*asoc
,
5971 struct sctp_chunk
*chunk
,
5972 sctp_cmd_seq_t
*commands
)
5974 sctp_datahdr_t
*data_hdr
;
5975 struct sctp_chunk
*err
;
5977 sctp_verb_t deliver
;
5980 struct sctp_tsnmap
*map
= (struct sctp_tsnmap
*)&asoc
->peer
.tsn_map
;
5981 struct sock
*sk
= asoc
->base
.sk
;
5986 data_hdr
= chunk
->subh
.data_hdr
= (sctp_datahdr_t
*)chunk
->skb
->data
;
5987 skb_pull(chunk
->skb
, sizeof(sctp_datahdr_t
));
5989 tsn
= ntohl(data_hdr
->tsn
);
5990 SCTP_DEBUG_PRINTK("eat_data: TSN 0x%x.\n", tsn
);
5992 /* ASSERT: Now skb->data is really the user data. */
5994 /* Process ECN based congestion.
5996 * Since the chunk structure is reused for all chunks within
5997 * a packet, we use ecn_ce_done to track if we've already
5998 * done CE processing for this packet.
6000 * We need to do ECN processing even if we plan to discard the
6004 if (!chunk
->ecn_ce_done
) {
6006 chunk
->ecn_ce_done
= 1;
6008 af
= sctp_get_af_specific(
6009 ipver2af(ip_hdr(chunk
->skb
)->version
));
6011 if (af
&& af
->is_ce(chunk
->skb
) && asoc
->peer
.ecn_capable
) {
6012 /* Do real work as sideffect. */
6013 sctp_add_cmd_sf(commands
, SCTP_CMD_ECN_CE
,
6018 tmp
= sctp_tsnmap_check(&asoc
->peer
.tsn_map
, tsn
);
6020 /* The TSN is too high--silently discard the chunk and
6021 * count on it getting retransmitted later.
6023 return SCTP_IERROR_HIGH_TSN
;
6024 } else if (tmp
> 0) {
6025 /* This is a duplicate. Record it. */
6026 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_DUP
, SCTP_U32(tsn
));
6027 return SCTP_IERROR_DUP_TSN
;
6030 /* This is a new TSN. */
6032 /* Discard if there is no room in the receive window.
6033 * Actually, allow a little bit of overflow (up to a MTU).
6035 datalen
= ntohs(chunk
->chunk_hdr
->length
);
6036 datalen
-= sizeof(sctp_data_chunk_t
);
6038 deliver
= SCTP_CMD_CHUNK_ULP
;
6040 /* Think about partial delivery. */
6041 if ((datalen
>= asoc
->rwnd
) && (!asoc
->ulpq
.pd_mode
)) {
6043 /* Even if we don't accept this chunk there is
6046 sctp_add_cmd_sf(commands
, SCTP_CMD_PART_DELIVER
, SCTP_NULL());
6049 /* Spill over rwnd a little bit. Note: While allowed, this spill over
6050 * seems a bit troublesome in that frag_point varies based on
6051 * PMTU. In cases, such as loopback, this might be a rather
6054 if ((!chunk
->data_accepted
) && (!asoc
->rwnd
|| asoc
->rwnd_over
||
6055 (datalen
> asoc
->rwnd
+ asoc
->frag_point
))) {
6057 /* If this is the next TSN, consider reneging to make
6058 * room. Note: Playing nice with a confused sender. A
6059 * malicious sender can still eat up all our buffer
6060 * space and in the future we may want to detect and
6061 * do more drastic reneging.
6063 if (sctp_tsnmap_has_gap(map
) &&
6064 (sctp_tsnmap_get_ctsn(map
) + 1) == tsn
) {
6065 SCTP_DEBUG_PRINTK("Reneging for tsn:%u\n", tsn
);
6066 deliver
= SCTP_CMD_RENEGE
;
6068 SCTP_DEBUG_PRINTK("Discard tsn: %u len: %Zd, "
6069 "rwnd: %d\n", tsn
, datalen
,
6071 return SCTP_IERROR_IGNORE_TSN
;
6076 * Also try to renege to limit our memory usage in the event that
6077 * we are under memory pressure
6078 * If we can't renege, don't worry about it, the sk_rmem_schedule
6079 * in sctp_ulpevent_make_rcvmsg will drop the frame if we grow our
6080 * memory usage too much
6082 if (*sk
->sk_prot_creator
->memory_pressure
) {
6083 if (sctp_tsnmap_has_gap(map
) &&
6084 (sctp_tsnmap_get_ctsn(map
) + 1) == tsn
) {
6085 SCTP_DEBUG_PRINTK("Under Pressure! Reneging for tsn:%u\n", tsn
);
6086 deliver
= SCTP_CMD_RENEGE
;
6091 * Section 3.3.10.9 No User Data (9)
6095 * No User Data: This error cause is returned to the originator of a
6096 * DATA chunk if a received DATA chunk has no user data.
6098 if (unlikely(0 == datalen
)) {
6099 err
= sctp_make_abort_no_data(asoc
, chunk
, tsn
);
6101 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
6104 /* We are going to ABORT, so we might as well stop
6105 * processing the rest of the chunks in the packet.
6107 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
,SCTP_NULL());
6108 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
6109 SCTP_ERROR(ECONNABORTED
));
6110 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
6111 SCTP_PERR(SCTP_ERROR_NO_DATA
));
6112 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
6113 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
6114 return SCTP_IERROR_NO_DATA
;
6117 chunk
->data_accepted
= 1;
6119 /* Note: Some chunks may get overcounted (if we drop) or overcounted
6120 * if we renege and the chunk arrives again.
6122 if (chunk
->chunk_hdr
->flags
& SCTP_DATA_UNORDERED
)
6123 SCTP_INC_STATS(SCTP_MIB_INUNORDERCHUNKS
);
6125 SCTP_INC_STATS(SCTP_MIB_INORDERCHUNKS
);
6129 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
6131 * If an endpoint receive a DATA chunk with an invalid stream
6132 * identifier, it shall acknowledge the reception of the DATA chunk
6133 * following the normal procedure, immediately send an ERROR chunk
6134 * with cause set to "Invalid Stream Identifier" (See Section 3.3.10)
6135 * and discard the DATA chunk.
6137 sid
= ntohs(data_hdr
->stream
);
6138 if (sid
>= asoc
->c
.sinit_max_instreams
) {
6139 /* Mark tsn as received even though we drop it */
6140 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_TSN
, SCTP_U32(tsn
));
6142 err
= sctp_make_op_error(asoc
, chunk
, SCTP_ERROR_INV_STRM
,
6144 sizeof(data_hdr
->stream
),
6147 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
6149 return SCTP_IERROR_BAD_STREAM
;
6152 /* Check to see if the SSN is possible for this TSN.
6153 * The biggest gap we can record is 4K wide. Since SSNs wrap
6154 * at an unsigned short, there is no way that an SSN can
6155 * wrap and for a valid TSN. We can simply check if the current
6156 * SSN is smaller then the next expected one. If it is, it wrapped
6159 ssn
= ntohs(data_hdr
->ssn
);
6160 if (ordered
&& SSN_lt(ssn
, sctp_ssn_peek(&asoc
->ssnmap
->in
, sid
))) {
6161 return SCTP_IERROR_PROTO_VIOLATION
;
6164 /* Send the data up to the user. Note: Schedule the
6165 * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK
6166 * chunk needs the updated rwnd.
6168 sctp_add_cmd_sf(commands
, deliver
, SCTP_CHUNK(chunk
));
6170 return SCTP_IERROR_NO_ERROR
;