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
->chunk_hdr
->type
,
398 (sctp_init_chunk_t
*)chunk
->chunk_hdr
,
402 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
404 /* If there are errors need to be reported for unknown parameters,
405 * make sure to reserve enough room in the INIT ACK for them.
409 len
= ntohs(err_chunk
->chunk_hdr
->length
) -
410 sizeof(sctp_chunkhdr_t
);
412 repl
= sctp_make_init_ack(new_asoc
, chunk
, GFP_ATOMIC
, len
);
416 /* If there are errors need to be reported for unknown parameters,
417 * include them in the outgoing INIT ACK as "Unrecognized parameter"
421 /* Get the "Unrecognized parameter" parameter(s) out of the
422 * ERROR chunk generated by sctp_verify_init(). Since the
423 * error cause code for "unknown parameter" and the
424 * "Unrecognized parameter" type is the same, we can
425 * construct the parameters in INIT ACK by copying the
428 unk_param
= (sctp_unrecognized_param_t
*)
429 ((__u8
*)(err_chunk
->chunk_hdr
) +
430 sizeof(sctp_chunkhdr_t
));
431 /* Replace the cause code with the "Unrecognized parameter"
434 sctp_addto_chunk(repl
, len
, unk_param
);
435 sctp_chunk_free(err_chunk
);
438 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(new_asoc
));
440 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
443 * Note: After sending out INIT ACK with the State Cookie parameter,
444 * "Z" MUST NOT allocate any resources, nor keep any states for the
445 * new association. Otherwise, "Z" will be vulnerable to resource
448 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
450 return SCTP_DISPOSITION_DELETE_TCB
;
453 sctp_association_free(new_asoc
);
456 sctp_chunk_free(err_chunk
);
457 return SCTP_DISPOSITION_NOMEM
;
461 * Respond to a normal INIT ACK chunk.
462 * We are the side that is initiating the association.
464 * Section: 5.1 Normal Establishment of an Association, C
465 * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init
466 * timer and leave COOKIE-WAIT state. "A" shall then send the State
467 * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start
468 * the T1-cookie timer, and enter the COOKIE-ECHOED state.
470 * Note: The COOKIE ECHO chunk can be bundled with any pending outbound
471 * DATA chunks, but it MUST be the first chunk in the packet and
472 * until the COOKIE ACK is returned the sender MUST NOT send any
473 * other packets to the peer.
475 * Verification Tag: 3.3.3
476 * If the value of the Initiate Tag in a received INIT ACK chunk is
477 * found to be 0, the receiver MUST treat it as an error and close the
478 * association by transmitting an ABORT.
481 * (endpoint, asoc, chunk)
484 * (asoc, reply_msg, msg_up, timers, counters)
486 * The return value is the disposition of the chunk.
488 sctp_disposition_t
sctp_sf_do_5_1C_ack(const struct sctp_endpoint
*ep
,
489 const struct sctp_association
*asoc
,
490 const sctp_subtype_t type
,
492 sctp_cmd_seq_t
*commands
)
494 struct sctp_chunk
*chunk
= arg
;
495 sctp_init_chunk_t
*initchunk
;
496 struct sctp_chunk
*err_chunk
;
497 struct sctp_packet
*packet
;
499 if (!sctp_vtag_verify(chunk
, asoc
))
500 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
503 * An endpoint MUST NOT bundle INIT, INIT ACK or
504 * SHUTDOWN COMPLETE with any other chunks.
506 if (!chunk
->singleton
)
507 return sctp_sf_violation_chunk(ep
, asoc
, type
, arg
, commands
);
509 /* Make sure that the INIT-ACK chunk has a valid length */
510 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_initack_chunk_t
)))
511 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
513 /* Grab the INIT header. */
514 chunk
->subh
.init_hdr
= (sctp_inithdr_t
*) chunk
->skb
->data
;
516 /* Verify the INIT chunk before processing it. */
518 if (!sctp_verify_init(asoc
, chunk
->chunk_hdr
->type
,
519 (sctp_init_chunk_t
*)chunk
->chunk_hdr
, chunk
,
522 sctp_error_t error
= SCTP_ERROR_NO_RESOURCE
;
524 /* This chunk contains fatal error. It is to be discarded.
525 * Send an ABORT, with causes. If there are no causes,
526 * then there wasn't enough memory. Just terminate
530 packet
= sctp_abort_pkt_new(ep
, asoc
, arg
,
531 (__u8
*)(err_chunk
->chunk_hdr
) +
532 sizeof(sctp_chunkhdr_t
),
533 ntohs(err_chunk
->chunk_hdr
->length
) -
534 sizeof(sctp_chunkhdr_t
));
536 sctp_chunk_free(err_chunk
);
539 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
540 SCTP_PACKET(packet
));
541 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
542 error
= SCTP_ERROR_INV_PARAM
;
546 /* SCTP-AUTH, Section 6.3:
547 * It should be noted that if the receiver wants to tear
548 * down an association in an authenticated way only, the
549 * handling of malformed packets should not result in
550 * tearing down the association.
552 * This means that if we only want to abort associations
553 * in an authenticated way (i.e AUTH+ABORT), then we
554 * can't destroy this association just because the packet
557 if (sctp_auth_recv_cid(SCTP_CID_ABORT
, asoc
))
558 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
560 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
561 return sctp_stop_t1_and_abort(commands
, error
, ECONNREFUSED
,
562 asoc
, chunk
->transport
);
565 /* Tag the variable length parameters. Note that we never
566 * convert the parameters in an INIT chunk.
568 chunk
->param_hdr
.v
= skb_pull(chunk
->skb
, sizeof(sctp_inithdr_t
));
570 initchunk
= (sctp_init_chunk_t
*) chunk
->chunk_hdr
;
572 sctp_add_cmd_sf(commands
, SCTP_CMD_PEER_INIT
,
573 SCTP_PEER_INIT(initchunk
));
575 /* Reset init error count upon receipt of INIT-ACK. */
576 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_COUNTER_RESET
, SCTP_NULL());
578 /* 5.1 C) "A" shall stop the T1-init timer and leave
579 * COOKIE-WAIT state. "A" shall then ... start the T1-cookie
580 * timer, and enter the COOKIE-ECHOED state.
582 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
583 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
584 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
585 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
586 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
587 SCTP_STATE(SCTP_STATE_COOKIE_ECHOED
));
589 /* SCTP-AUTH: genereate the assocition shared keys so that
590 * we can potentially signe the COOKIE-ECHO.
592 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_SHKEY
, SCTP_NULL());
594 /* 5.1 C) "A" shall then send the State Cookie received in the
595 * INIT ACK chunk in a COOKIE ECHO chunk, ...
597 /* If there is any errors to report, send the ERROR chunk generated
598 * for unknown parameters as well.
600 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_COOKIE_ECHO
,
601 SCTP_CHUNK(err_chunk
));
603 return SCTP_DISPOSITION_CONSUME
;
607 * Respond to a normal COOKIE ECHO chunk.
608 * We are the side that is being asked for an association.
610 * Section: 5.1 Normal Establishment of an Association, D
611 * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply
612 * with a COOKIE ACK chunk after building a TCB and moving to
613 * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with
614 * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK
615 * chunk MUST be the first chunk in the packet.
617 * IMPLEMENTATION NOTE: An implementation may choose to send the
618 * Communication Up notification to the SCTP user upon reception
619 * of a valid COOKIE ECHO chunk.
621 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
622 * D) Rules for packet carrying a COOKIE ECHO
624 * - When sending a COOKIE ECHO, the endpoint MUST use the value of the
625 * Initial Tag received in the INIT ACK.
627 * - The receiver of a COOKIE ECHO follows the procedures in Section 5.
630 * (endpoint, asoc, chunk)
633 * (asoc, reply_msg, msg_up, timers, counters)
635 * The return value is the disposition of the chunk.
637 sctp_disposition_t
sctp_sf_do_5_1D_ce(const struct sctp_endpoint
*ep
,
638 const struct sctp_association
*asoc
,
639 const sctp_subtype_t type
, void *arg
,
640 sctp_cmd_seq_t
*commands
)
642 struct sctp_chunk
*chunk
= arg
;
643 struct sctp_association
*new_asoc
;
644 sctp_init_chunk_t
*peer_init
;
645 struct sctp_chunk
*repl
;
646 struct sctp_ulpevent
*ev
, *ai_ev
= NULL
;
648 struct sctp_chunk
*err_chk_p
;
651 /* If the packet is an OOTB packet which is temporarily on the
652 * control endpoint, respond with an ABORT.
654 if (ep
== sctp_sk((sctp_get_ctl_sock()))->ep
) {
655 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES
);
656 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
, commands
);
659 /* Make sure that the COOKIE_ECHO chunk has a valid length.
660 * In this case, we check that we have enough for at least a
661 * chunk header. More detailed verification is done
662 * in sctp_unpack_cookie().
664 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
665 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
667 /* If the endpoint is not listening or if the number of associations
668 * on the TCP-style socket exceed the max backlog, respond with an
672 if (!sctp_sstate(sk
, LISTENING
) ||
673 (sctp_style(sk
, TCP
) && sk_acceptq_is_full(sk
)))
674 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
, commands
);
676 /* "Decode" the chunk. We have no optional parameters so we
679 chunk
->subh
.cookie_hdr
=
680 (struct sctp_signed_cookie
*)chunk
->skb
->data
;
681 if (!pskb_pull(chunk
->skb
, ntohs(chunk
->chunk_hdr
->length
) -
682 sizeof(sctp_chunkhdr_t
)))
685 /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
686 * "Z" will reply with a COOKIE ACK chunk after building a TCB
687 * and moving to the ESTABLISHED state.
689 new_asoc
= sctp_unpack_cookie(ep
, asoc
, chunk
, GFP_ATOMIC
, &error
,
693 * If the re-build failed, what is the proper error path
696 * [We should abort the association. --piggy]
699 /* FIXME: Several errors are possible. A bad cookie should
700 * be silently discarded, but think about logging it too.
703 case -SCTP_IERROR_NOMEM
:
706 case -SCTP_IERROR_STALE_COOKIE
:
707 sctp_send_stale_cookie_err(ep
, asoc
, chunk
, commands
,
709 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
711 case -SCTP_IERROR_BAD_SIG
:
713 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
718 /* Delay state machine commands until later.
720 * Re-build the bind address for the association is done in
721 * the sctp_unpack_cookie() already.
723 /* This is a brand-new association, so these are not yet side
724 * effects--it is safe to run them here.
726 peer_init
= &chunk
->subh
.cookie_hdr
->c
.peer_init
[0];
728 if (!sctp_process_init(new_asoc
, chunk
->chunk_hdr
->type
,
729 &chunk
->subh
.cookie_hdr
->c
.peer_addr
,
730 peer_init
, GFP_ATOMIC
))
733 /* SCTP-AUTH: Now that we've populate required fields in
734 * sctp_process_init, set up the assocaition shared keys as
735 * necessary so that we can potentially authenticate the ACK
737 error
= sctp_auth_asoc_init_active_key(new_asoc
, GFP_ATOMIC
);
741 /* SCTP-AUTH: auth_chunk pointer is only set when the cookie-echo
742 * is supposed to be authenticated and we have to do delayed
743 * authentication. We've just recreated the association using
744 * the information in the cookie and now it's much easier to
745 * do the authentication.
747 if (chunk
->auth_chunk
) {
748 struct sctp_chunk auth
;
751 /* set-up our fake chunk so that we can process it */
752 auth
.skb
= chunk
->auth_chunk
;
753 auth
.asoc
= chunk
->asoc
;
754 auth
.sctp_hdr
= chunk
->sctp_hdr
;
755 auth
.chunk_hdr
= (sctp_chunkhdr_t
*)skb_push(chunk
->auth_chunk
,
756 sizeof(sctp_chunkhdr_t
));
757 skb_pull(chunk
->auth_chunk
, sizeof(sctp_chunkhdr_t
));
758 auth
.transport
= chunk
->transport
;
760 ret
= sctp_sf_authenticate(ep
, new_asoc
, type
, &auth
);
762 /* We can now safely free the auth_chunk clone */
763 kfree_skb(chunk
->auth_chunk
);
765 if (ret
!= SCTP_IERROR_NO_ERROR
) {
766 sctp_association_free(new_asoc
);
767 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
771 repl
= sctp_make_cookie_ack(new_asoc
, chunk
);
775 /* RFC 2960 5.1 Normal Establishment of an Association
777 * D) IMPLEMENTATION NOTE: An implementation may choose to
778 * send the Communication Up notification to the SCTP user
779 * upon reception of a valid COOKIE ECHO chunk.
781 ev
= sctp_ulpevent_make_assoc_change(new_asoc
, 0, SCTP_COMM_UP
, 0,
782 new_asoc
->c
.sinit_num_ostreams
,
783 new_asoc
->c
.sinit_max_instreams
,
788 /* Sockets API Draft Section 5.3.1.6
789 * When a peer sends a Adaptation Layer Indication parameter , SCTP
790 * delivers this notification to inform the application that of the
791 * peers requested adaptation layer.
793 if (new_asoc
->peer
.adaptation_ind
) {
794 ai_ev
= sctp_ulpevent_make_adaptation_indication(new_asoc
,
800 /* Add all the state machine commands now since we've created
801 * everything. This way we don't introduce memory corruptions
802 * during side-effect processing and correclty count established
805 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(new_asoc
));
806 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
807 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
808 SCTP_INC_STATS(SCTP_MIB_CURRESTAB
);
809 SCTP_INC_STATS(SCTP_MIB_PASSIVEESTABS
);
810 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_START
, SCTP_NULL());
812 if (new_asoc
->autoclose
)
813 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
814 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
816 /* This will send the COOKIE ACK */
817 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
819 /* Queue the ASSOC_CHANGE event */
820 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
822 /* Send up the Adaptation Layer Indication event */
824 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
825 SCTP_ULPEVENT(ai_ev
));
827 return SCTP_DISPOSITION_CONSUME
;
830 sctp_ulpevent_free(ev
);
832 sctp_chunk_free(repl
);
834 sctp_association_free(new_asoc
);
836 return SCTP_DISPOSITION_NOMEM
;
840 * Respond to a normal COOKIE ACK chunk.
841 * We are the side that is being asked for an association.
843 * RFC 2960 5.1 Normal Establishment of an Association
845 * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the
846 * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie
847 * timer. It may also notify its ULP about the successful
848 * establishment of the association with a Communication Up
849 * notification (see Section 10).
853 * (endpoint, asoc, chunk)
856 * (asoc, reply_msg, msg_up, timers, counters)
858 * The return value is the disposition of the chunk.
860 sctp_disposition_t
sctp_sf_do_5_1E_ca(const struct sctp_endpoint
*ep
,
861 const struct sctp_association
*asoc
,
862 const sctp_subtype_t type
, void *arg
,
863 sctp_cmd_seq_t
*commands
)
865 struct sctp_chunk
*chunk
= arg
;
866 struct sctp_ulpevent
*ev
;
868 if (!sctp_vtag_verify(chunk
, asoc
))
869 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
871 /* Verify that the chunk length for the COOKIE-ACK is OK.
872 * If we don't do this, any bundled chunks may be junked.
874 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
875 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
878 /* Reset init error count upon receipt of COOKIE-ACK,
879 * to avoid problems with the managemement of this
880 * counter in stale cookie situations when a transition back
881 * from the COOKIE-ECHOED state to the COOKIE-WAIT
882 * state is performed.
884 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_COUNTER_RESET
, SCTP_NULL());
886 /* RFC 2960 5.1 Normal Establishment of an Association
888 * E) Upon reception of the COOKIE ACK, endpoint "A" will move
889 * from the COOKIE-ECHOED state to the ESTABLISHED state,
890 * stopping the T1-cookie timer.
892 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
893 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
894 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
895 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
896 SCTP_INC_STATS(SCTP_MIB_CURRESTAB
);
897 SCTP_INC_STATS(SCTP_MIB_ACTIVEESTABS
);
898 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_START
, SCTP_NULL());
900 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
901 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
903 /* It may also notify its ULP about the successful
904 * establishment of the association with a Communication Up
905 * notification (see Section 10).
907 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_COMM_UP
,
908 0, asoc
->c
.sinit_num_ostreams
,
909 asoc
->c
.sinit_max_instreams
,
915 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
917 /* Sockets API Draft Section 5.3.1.6
918 * When a peer sends a Adaptation Layer Indication parameter , SCTP
919 * delivers this notification to inform the application that of the
920 * peers requested adaptation layer.
922 if (asoc
->peer
.adaptation_ind
) {
923 ev
= sctp_ulpevent_make_adaptation_indication(asoc
, GFP_ATOMIC
);
927 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
931 return SCTP_DISPOSITION_CONSUME
;
933 return SCTP_DISPOSITION_NOMEM
;
936 /* Generate and sendout a heartbeat packet. */
937 static sctp_disposition_t
sctp_sf_heartbeat(const struct sctp_endpoint
*ep
,
938 const struct sctp_association
*asoc
,
939 const sctp_subtype_t type
,
941 sctp_cmd_seq_t
*commands
)
943 struct sctp_transport
*transport
= (struct sctp_transport
*) arg
;
944 struct sctp_chunk
*reply
;
945 sctp_sender_hb_info_t hbinfo
;
948 hbinfo
.param_hdr
.type
= SCTP_PARAM_HEARTBEAT_INFO
;
949 hbinfo
.param_hdr
.length
= htons(sizeof(sctp_sender_hb_info_t
));
950 hbinfo
.daddr
= transport
->ipaddr
;
951 hbinfo
.sent_at
= jiffies
;
952 hbinfo
.hb_nonce
= transport
->hb_nonce
;
954 /* Send a heartbeat to our peer. */
955 paylen
= sizeof(sctp_sender_hb_info_t
);
956 reply
= sctp_make_heartbeat(asoc
, transport
, &hbinfo
, paylen
);
958 return SCTP_DISPOSITION_NOMEM
;
960 /* Set rto_pending indicating that an RTT measurement
961 * is started with this heartbeat chunk.
963 sctp_add_cmd_sf(commands
, SCTP_CMD_RTO_PENDING
,
964 SCTP_TRANSPORT(transport
));
966 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
967 return SCTP_DISPOSITION_CONSUME
;
970 /* Generate a HEARTBEAT packet on the given transport. */
971 sctp_disposition_t
sctp_sf_sendbeat_8_3(const struct sctp_endpoint
*ep
,
972 const struct sctp_association
*asoc
,
973 const sctp_subtype_t type
,
975 sctp_cmd_seq_t
*commands
)
977 struct sctp_transport
*transport
= (struct sctp_transport
*) arg
;
979 if (asoc
->overall_error_count
>= asoc
->max_retrans
) {
980 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
981 SCTP_ERROR(ETIMEDOUT
));
982 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
983 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
984 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
985 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
986 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
987 return SCTP_DISPOSITION_DELETE_TCB
;
991 * The Sender-specific Heartbeat Info field should normally include
992 * information about the sender's current time when this HEARTBEAT
993 * chunk is sent and the destination transport address to which this
994 * HEARTBEAT is sent (see Section 8.3).
997 if (transport
->param_flags
& SPP_HB_ENABLE
) {
998 if (SCTP_DISPOSITION_NOMEM
==
999 sctp_sf_heartbeat(ep
, asoc
, type
, arg
,
1001 return SCTP_DISPOSITION_NOMEM
;
1003 /* Set transport error counter and association error counter
1004 * when sending heartbeat.
1006 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSPORT_HB_SENT
,
1007 SCTP_TRANSPORT(transport
));
1009 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSPORT_IDLE
,
1010 SCTP_TRANSPORT(transport
));
1011 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMER_UPDATE
,
1012 SCTP_TRANSPORT(transport
));
1014 return SCTP_DISPOSITION_CONSUME
;
1018 * Process an heartbeat request.
1020 * Section: 8.3 Path Heartbeat
1021 * The receiver of the HEARTBEAT should immediately respond with a
1022 * HEARTBEAT ACK that contains the Heartbeat Information field copied
1023 * from the received HEARTBEAT chunk.
1025 * Verification Tag: 8.5 Verification Tag [Normal verification]
1026 * When receiving an SCTP packet, the endpoint MUST ensure that the
1027 * value in the Verification Tag field of the received SCTP packet
1028 * matches its own Tag. If the received Verification Tag value does not
1029 * match the receiver's own tag value, the receiver shall silently
1030 * discard the packet and shall not process it any further except for
1031 * those cases listed in Section 8.5.1 below.
1034 * (endpoint, asoc, chunk)
1037 * (asoc, reply_msg, msg_up, timers, counters)
1039 * The return value is the disposition of the chunk.
1041 sctp_disposition_t
sctp_sf_beat_8_3(const struct sctp_endpoint
*ep
,
1042 const struct sctp_association
*asoc
,
1043 const sctp_subtype_t type
,
1045 sctp_cmd_seq_t
*commands
)
1047 struct sctp_chunk
*chunk
= arg
;
1048 struct sctp_chunk
*reply
;
1051 if (!sctp_vtag_verify(chunk
, asoc
))
1052 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
1054 /* Make sure that the HEARTBEAT chunk has a valid length. */
1055 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_heartbeat_chunk_t
)))
1056 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
1059 /* 8.3 The receiver of the HEARTBEAT should immediately
1060 * respond with a HEARTBEAT ACK that contains the Heartbeat
1061 * Information field copied from the received HEARTBEAT chunk.
1063 chunk
->subh
.hb_hdr
= (sctp_heartbeathdr_t
*) chunk
->skb
->data
;
1064 paylen
= ntohs(chunk
->chunk_hdr
->length
) - sizeof(sctp_chunkhdr_t
);
1065 if (!pskb_pull(chunk
->skb
, paylen
))
1068 reply
= sctp_make_heartbeat_ack(asoc
, chunk
,
1069 chunk
->subh
.hb_hdr
, paylen
);
1073 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
1074 return SCTP_DISPOSITION_CONSUME
;
1077 return SCTP_DISPOSITION_NOMEM
;
1081 * Process the returning HEARTBEAT ACK.
1083 * Section: 8.3 Path Heartbeat
1084 * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT
1085 * should clear the error counter of the destination transport
1086 * address to which the HEARTBEAT was sent, and mark the destination
1087 * transport address as active if it is not so marked. The endpoint may
1088 * optionally report to the upper layer when an inactive destination
1089 * address is marked as active due to the reception of the latest
1090 * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also
1091 * clear the association overall error count as well (as defined
1094 * The receiver of the HEARTBEAT ACK should also perform an RTT
1095 * measurement for that destination transport address using the time
1096 * value carried in the HEARTBEAT ACK chunk.
1098 * Verification Tag: 8.5 Verification Tag [Normal verification]
1101 * (endpoint, asoc, chunk)
1104 * (asoc, reply_msg, msg_up, timers, counters)
1106 * The return value is the disposition of the chunk.
1108 sctp_disposition_t
sctp_sf_backbeat_8_3(const struct sctp_endpoint
*ep
,
1109 const struct sctp_association
*asoc
,
1110 const sctp_subtype_t type
,
1112 sctp_cmd_seq_t
*commands
)
1114 struct sctp_chunk
*chunk
= arg
;
1115 union sctp_addr from_addr
;
1116 struct sctp_transport
*link
;
1117 sctp_sender_hb_info_t
*hbinfo
;
1118 unsigned long max_interval
;
1120 if (!sctp_vtag_verify(chunk
, asoc
))
1121 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
1123 /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */
1124 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
) +
1125 sizeof(sctp_sender_hb_info_t
)))
1126 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
1129 hbinfo
= (sctp_sender_hb_info_t
*) chunk
->skb
->data
;
1130 /* Make sure that the length of the parameter is what we expect */
1131 if (ntohs(hbinfo
->param_hdr
.length
) !=
1132 sizeof(sctp_sender_hb_info_t
)) {
1133 return SCTP_DISPOSITION_DISCARD
;
1136 from_addr
= hbinfo
->daddr
;
1137 link
= sctp_assoc_lookup_paddr(asoc
, &from_addr
);
1139 /* This should never happen, but lets log it if so. */
1140 if (unlikely(!link
)) {
1141 if (from_addr
.sa
.sa_family
== AF_INET6
) {
1142 if (net_ratelimit())
1143 pr_warn("%s association %p could not find address %pI6\n",
1146 &from_addr
.v6
.sin6_addr
);
1148 if (net_ratelimit())
1149 pr_warn("%s association %p could not find address %pI4\n",
1152 &from_addr
.v4
.sin_addr
.s_addr
);
1154 return SCTP_DISPOSITION_DISCARD
;
1157 /* Validate the 64-bit random nonce. */
1158 if (hbinfo
->hb_nonce
!= link
->hb_nonce
)
1159 return SCTP_DISPOSITION_DISCARD
;
1161 max_interval
= link
->hbinterval
+ link
->rto
;
1163 /* Check if the timestamp looks valid. */
1164 if (time_after(hbinfo
->sent_at
, jiffies
) ||
1165 time_after(jiffies
, hbinfo
->sent_at
+ max_interval
)) {
1166 SCTP_DEBUG_PRINTK("%s: HEARTBEAT ACK with invalid timestamp "
1167 "received for transport: %p\n",
1169 return SCTP_DISPOSITION_DISCARD
;
1172 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of
1173 * the HEARTBEAT should clear the error counter of the
1174 * destination transport address to which the HEARTBEAT was
1175 * sent and mark the destination transport address as active if
1176 * it is not so marked.
1178 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSPORT_ON
, SCTP_TRANSPORT(link
));
1180 return SCTP_DISPOSITION_CONSUME
;
1183 /* Helper function to send out an abort for the restart
1186 static int sctp_sf_send_restart_abort(union sctp_addr
*ssa
,
1187 struct sctp_chunk
*init
,
1188 sctp_cmd_seq_t
*commands
)
1191 struct sctp_packet
*pkt
;
1192 union sctp_addr_param
*addrparm
;
1193 struct sctp_errhdr
*errhdr
;
1194 struct sctp_endpoint
*ep
;
1195 char buffer
[sizeof(struct sctp_errhdr
)+sizeof(union sctp_addr_param
)];
1196 struct sctp_af
*af
= sctp_get_af_specific(ssa
->v4
.sin_family
);
1198 /* Build the error on the stack. We are way to malloc crazy
1199 * throughout the code today.
1201 errhdr
= (struct sctp_errhdr
*)buffer
;
1202 addrparm
= (union sctp_addr_param
*)errhdr
->variable
;
1204 /* Copy into a parm format. */
1205 len
= af
->to_addr_param(ssa
, addrparm
);
1206 len
+= sizeof(sctp_errhdr_t
);
1208 errhdr
->cause
= SCTP_ERROR_RESTART
;
1209 errhdr
->length
= htons(len
);
1211 /* Assign to the control socket. */
1212 ep
= sctp_sk((sctp_get_ctl_sock()))->ep
;
1214 /* Association is NULL since this may be a restart attack and we
1215 * want to send back the attacker's vtag.
1217 pkt
= sctp_abort_pkt_new(ep
, NULL
, init
, errhdr
, len
);
1221 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
, SCTP_PACKET(pkt
));
1223 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
1225 /* Discard the rest of the inbound packet. */
1226 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
, SCTP_NULL());
1229 /* Even if there is no memory, treat as a failure so
1230 * the packet will get dropped.
1235 static bool list_has_sctp_addr(const struct list_head
*list
,
1236 union sctp_addr
*ipaddr
)
1238 struct sctp_transport
*addr
;
1240 list_for_each_entry(addr
, list
, transports
) {
1241 if (sctp_cmp_addr_exact(ipaddr
, &addr
->ipaddr
))
1247 /* A restart is occurring, check to make sure no new addresses
1248 * are being added as we may be under a takeover attack.
1250 static int sctp_sf_check_restart_addrs(const struct sctp_association
*new_asoc
,
1251 const struct sctp_association
*asoc
,
1252 struct sctp_chunk
*init
,
1253 sctp_cmd_seq_t
*commands
)
1255 struct sctp_transport
*new_addr
;
1258 /* Implementor's Guide - Section 5.2.2
1260 * Before responding the endpoint MUST check to see if the
1261 * unexpected INIT adds new addresses to the association. If new
1262 * addresses are added to the association, the endpoint MUST respond
1266 /* Search through all current addresses and make sure
1267 * we aren't adding any new ones.
1269 list_for_each_entry(new_addr
, &new_asoc
->peer
.transport_addr_list
,
1271 if (!list_has_sctp_addr(&asoc
->peer
.transport_addr_list
,
1272 &new_addr
->ipaddr
)) {
1273 sctp_sf_send_restart_abort(&new_addr
->ipaddr
, init
,
1280 /* Return success if all addresses were found. */
1284 /* Populate the verification/tie tags based on overlapping INIT
1287 * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state.
1289 static void sctp_tietags_populate(struct sctp_association
*new_asoc
,
1290 const struct sctp_association
*asoc
)
1292 switch (asoc
->state
) {
1294 /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */
1296 case SCTP_STATE_COOKIE_WAIT
:
1297 new_asoc
->c
.my_vtag
= asoc
->c
.my_vtag
;
1298 new_asoc
->c
.my_ttag
= asoc
->c
.my_vtag
;
1299 new_asoc
->c
.peer_ttag
= 0;
1302 case SCTP_STATE_COOKIE_ECHOED
:
1303 new_asoc
->c
.my_vtag
= asoc
->c
.my_vtag
;
1304 new_asoc
->c
.my_ttag
= asoc
->c
.my_vtag
;
1305 new_asoc
->c
.peer_ttag
= asoc
->c
.peer_vtag
;
1308 /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED,
1309 * COOKIE-WAIT and SHUTDOWN-ACK-SENT
1312 new_asoc
->c
.my_ttag
= asoc
->c
.my_vtag
;
1313 new_asoc
->c
.peer_ttag
= asoc
->c
.peer_vtag
;
1317 /* Other parameters for the endpoint SHOULD be copied from the
1318 * existing parameters of the association (e.g. number of
1319 * outbound streams) into the INIT ACK and cookie.
1321 new_asoc
->rwnd
= asoc
->rwnd
;
1322 new_asoc
->c
.sinit_num_ostreams
= asoc
->c
.sinit_num_ostreams
;
1323 new_asoc
->c
.sinit_max_instreams
= asoc
->c
.sinit_max_instreams
;
1324 new_asoc
->c
.initial_tsn
= asoc
->c
.initial_tsn
;
1328 * Compare vtag/tietag values to determine unexpected COOKIE-ECHO
1331 * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists.
1333 * Returns value representing action to be taken. These action values
1334 * correspond to Action/Description values in RFC 2960, Table 2.
1336 static char sctp_tietags_compare(struct sctp_association
*new_asoc
,
1337 const struct sctp_association
*asoc
)
1339 /* In this case, the peer may have restarted. */
1340 if ((asoc
->c
.my_vtag
!= new_asoc
->c
.my_vtag
) &&
1341 (asoc
->c
.peer_vtag
!= new_asoc
->c
.peer_vtag
) &&
1342 (asoc
->c
.my_vtag
== new_asoc
->c
.my_ttag
) &&
1343 (asoc
->c
.peer_vtag
== new_asoc
->c
.peer_ttag
))
1346 /* Collision case B. */
1347 if ((asoc
->c
.my_vtag
== new_asoc
->c
.my_vtag
) &&
1348 ((asoc
->c
.peer_vtag
!= new_asoc
->c
.peer_vtag
) ||
1349 (0 == asoc
->c
.peer_vtag
))) {
1353 /* Collision case D. */
1354 if ((asoc
->c
.my_vtag
== new_asoc
->c
.my_vtag
) &&
1355 (asoc
->c
.peer_vtag
== new_asoc
->c
.peer_vtag
))
1358 /* Collision case C. */
1359 if ((asoc
->c
.my_vtag
!= new_asoc
->c
.my_vtag
) &&
1360 (asoc
->c
.peer_vtag
== new_asoc
->c
.peer_vtag
) &&
1361 (0 == new_asoc
->c
.my_ttag
) &&
1362 (0 == new_asoc
->c
.peer_ttag
))
1365 /* No match to any of the special cases; discard this packet. */
1369 /* Common helper routine for both duplicate and simulataneous INIT
1372 static sctp_disposition_t
sctp_sf_do_unexpected_init(
1373 const struct sctp_endpoint
*ep
,
1374 const struct sctp_association
*asoc
,
1375 const sctp_subtype_t type
,
1376 void *arg
, sctp_cmd_seq_t
*commands
)
1378 sctp_disposition_t retval
;
1379 struct sctp_chunk
*chunk
= arg
;
1380 struct sctp_chunk
*repl
;
1381 struct sctp_association
*new_asoc
;
1382 struct sctp_chunk
*err_chunk
;
1383 struct sctp_packet
*packet
;
1384 sctp_unrecognized_param_t
*unk_param
;
1388 * An endpoint MUST NOT bundle INIT, INIT ACK or
1389 * SHUTDOWN COMPLETE with any other chunks.
1392 * Furthermore, we require that the receiver of an INIT chunk MUST
1393 * enforce these rules by silently discarding an arriving packet
1394 * with an INIT chunk that is bundled with other chunks.
1396 if (!chunk
->singleton
)
1397 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
1399 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
1402 if (chunk
->sctp_hdr
->vtag
!= 0)
1403 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
, commands
);
1405 /* Make sure that the INIT chunk has a valid length.
1406 * In this case, we generate a protocol violation since we have
1407 * an association established.
1409 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_init_chunk_t
)))
1410 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
1412 /* Grab the INIT header. */
1413 chunk
->subh
.init_hdr
= (sctp_inithdr_t
*) chunk
->skb
->data
;
1415 /* Tag the variable length parameters. */
1416 chunk
->param_hdr
.v
= skb_pull(chunk
->skb
, sizeof(sctp_inithdr_t
));
1418 /* Verify the INIT chunk before processing it. */
1420 if (!sctp_verify_init(asoc
, chunk
->chunk_hdr
->type
,
1421 (sctp_init_chunk_t
*)chunk
->chunk_hdr
, chunk
,
1423 /* This chunk contains fatal error. It is to be discarded.
1424 * Send an ABORT, with causes if there is any.
1427 packet
= sctp_abort_pkt_new(ep
, asoc
, arg
,
1428 (__u8
*)(err_chunk
->chunk_hdr
) +
1429 sizeof(sctp_chunkhdr_t
),
1430 ntohs(err_chunk
->chunk_hdr
->length
) -
1431 sizeof(sctp_chunkhdr_t
));
1434 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
1435 SCTP_PACKET(packet
));
1436 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
1437 retval
= SCTP_DISPOSITION_CONSUME
;
1439 retval
= SCTP_DISPOSITION_NOMEM
;
1443 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
,
1449 * Other parameters for the endpoint SHOULD be copied from the
1450 * existing parameters of the association (e.g. number of
1451 * outbound streams) into the INIT ACK and cookie.
1452 * FIXME: We are copying parameters from the endpoint not the
1455 new_asoc
= sctp_make_temp_asoc(ep
, chunk
, GFP_ATOMIC
);
1459 if (sctp_assoc_set_bind_addr_from_ep(new_asoc
,
1460 sctp_scope(sctp_source(chunk
)), GFP_ATOMIC
) < 0)
1463 /* In the outbound INIT ACK the endpoint MUST copy its current
1464 * Verification Tag and Peers Verification tag into a reserved
1465 * place (local tie-tag and per tie-tag) within the state cookie.
1467 if (!sctp_process_init(new_asoc
, chunk
->chunk_hdr
->type
,
1469 (sctp_init_chunk_t
*)chunk
->chunk_hdr
,
1473 /* Make sure no new addresses are being added during the
1474 * restart. Do not do this check for COOKIE-WAIT state,
1475 * since there are no peer addresses to check against.
1476 * Upon return an ABORT will have been sent if needed.
1478 if (!sctp_state(asoc
, COOKIE_WAIT
)) {
1479 if (!sctp_sf_check_restart_addrs(new_asoc
, asoc
, chunk
,
1481 retval
= SCTP_DISPOSITION_CONSUME
;
1486 sctp_tietags_populate(new_asoc
, asoc
);
1488 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
1490 /* If there are errors need to be reported for unknown parameters,
1491 * make sure to reserve enough room in the INIT ACK for them.
1495 len
= ntohs(err_chunk
->chunk_hdr
->length
) -
1496 sizeof(sctp_chunkhdr_t
);
1499 repl
= sctp_make_init_ack(new_asoc
, chunk
, GFP_ATOMIC
, len
);
1503 /* If there are errors need to be reported for unknown parameters,
1504 * include them in the outgoing INIT ACK as "Unrecognized parameter"
1508 /* Get the "Unrecognized parameter" parameter(s) out of the
1509 * ERROR chunk generated by sctp_verify_init(). Since the
1510 * error cause code for "unknown parameter" and the
1511 * "Unrecognized parameter" type is the same, we can
1512 * construct the parameters in INIT ACK by copying the
1513 * ERROR causes over.
1515 unk_param
= (sctp_unrecognized_param_t
*)
1516 ((__u8
*)(err_chunk
->chunk_hdr
) +
1517 sizeof(sctp_chunkhdr_t
));
1518 /* Replace the cause code with the "Unrecognized parameter"
1521 sctp_addto_chunk(repl
, len
, unk_param
);
1524 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(new_asoc
));
1525 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1528 * Note: After sending out INIT ACK with the State Cookie parameter,
1529 * "Z" MUST NOT allocate any resources for this new association.
1530 * Otherwise, "Z" will be vulnerable to resource attacks.
1532 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
1533 retval
= SCTP_DISPOSITION_CONSUME
;
1538 retval
= SCTP_DISPOSITION_NOMEM
;
1541 sctp_association_free(new_asoc
);
1544 sctp_chunk_free(err_chunk
);
1549 * Handle simultaneous INIT.
1550 * This means we started an INIT and then we got an INIT request from
1553 * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B)
1554 * This usually indicates an initialization collision, i.e., each
1555 * endpoint is attempting, at about the same time, to establish an
1556 * association with the other endpoint.
1558 * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an
1559 * endpoint MUST respond with an INIT ACK using the same parameters it
1560 * sent in its original INIT chunk (including its Verification Tag,
1561 * unchanged). These original parameters are combined with those from the
1562 * newly received INIT chunk. The endpoint shall also generate a State
1563 * Cookie with the INIT ACK. The endpoint uses the parameters sent in its
1564 * INIT to calculate the State Cookie.
1566 * After that, the endpoint MUST NOT change its state, the T1-init
1567 * timer shall be left running and the corresponding TCB MUST NOT be
1568 * destroyed. The normal procedures for handling State Cookies when
1569 * a TCB exists will resolve the duplicate INITs to a single association.
1571 * For an endpoint that is in the COOKIE-ECHOED state it MUST populate
1572 * its Tie-Tags with the Tag information of itself and its peer (see
1573 * section 5.2.2 for a description of the Tie-Tags).
1575 * Verification Tag: Not explicit, but an INIT can not have a valid
1576 * verification tag, so we skip the check.
1579 * (endpoint, asoc, chunk)
1582 * (asoc, reply_msg, msg_up, timers, counters)
1584 * The return value is the disposition of the chunk.
1586 sctp_disposition_t
sctp_sf_do_5_2_1_siminit(const struct sctp_endpoint
*ep
,
1587 const struct sctp_association
*asoc
,
1588 const sctp_subtype_t type
,
1590 sctp_cmd_seq_t
*commands
)
1592 /* Call helper to do the real work for both simulataneous and
1593 * duplicate INIT chunk handling.
1595 return sctp_sf_do_unexpected_init(ep
, asoc
, type
, arg
, commands
);
1599 * Handle duplicated INIT messages. These are usually delayed
1602 * Section: 5.2.2 Unexpected INIT in States Other than CLOSED,
1603 * COOKIE-ECHOED and COOKIE-WAIT
1605 * Unless otherwise stated, upon reception of an unexpected INIT for
1606 * this association, the endpoint shall generate an INIT ACK with a
1607 * State Cookie. In the outbound INIT ACK the endpoint MUST copy its
1608 * current Verification Tag and peer's Verification Tag into a reserved
1609 * place within the state cookie. We shall refer to these locations as
1610 * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet
1611 * containing this INIT ACK MUST carry a Verification Tag value equal to
1612 * the Initiation Tag found in the unexpected INIT. And the INIT ACK
1613 * MUST contain a new Initiation Tag (randomly generated see Section
1614 * 5.3.1). Other parameters for the endpoint SHOULD be copied from the
1615 * existing parameters of the association (e.g. number of outbound
1616 * streams) into the INIT ACK and cookie.
1618 * After sending out the INIT ACK, the endpoint shall take no further
1619 * actions, i.e., the existing association, including its current state,
1620 * and the corresponding TCB MUST NOT be changed.
1622 * Note: Only when a TCB exists and the association is not in a COOKIE-
1623 * WAIT state are the Tie-Tags populated. For a normal association INIT
1624 * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be
1625 * set to 0 (indicating that no previous TCB existed). The INIT ACK and
1626 * State Cookie are populated as specified in section 5.2.1.
1628 * Verification Tag: Not specified, but an INIT has no way of knowing
1629 * what the verification tag could be, so we ignore it.
1632 * (endpoint, asoc, chunk)
1635 * (asoc, reply_msg, msg_up, timers, counters)
1637 * The return value is the disposition of the chunk.
1639 sctp_disposition_t
sctp_sf_do_5_2_2_dupinit(const struct sctp_endpoint
*ep
,
1640 const struct sctp_association
*asoc
,
1641 const sctp_subtype_t type
,
1643 sctp_cmd_seq_t
*commands
)
1645 /* Call helper to do the real work for both simulataneous and
1646 * duplicate INIT chunk handling.
1648 return sctp_sf_do_unexpected_init(ep
, asoc
, type
, arg
, commands
);
1653 * Unexpected INIT-ACK handler.
1656 * If an INIT ACK received by an endpoint in any state other than the
1657 * COOKIE-WAIT state, the endpoint should discard the INIT ACK chunk.
1658 * An unexpected INIT ACK usually indicates the processing of an old or
1659 * duplicated INIT chunk.
1661 sctp_disposition_t
sctp_sf_do_5_2_3_initack(const struct sctp_endpoint
*ep
,
1662 const struct sctp_association
*asoc
,
1663 const sctp_subtype_t type
,
1664 void *arg
, sctp_cmd_seq_t
*commands
)
1666 /* Per the above section, we'll discard the chunk if we have an
1667 * endpoint. If this is an OOTB INIT-ACK, treat it as such.
1669 if (ep
== sctp_sk((sctp_get_ctl_sock()))->ep
)
1670 return sctp_sf_ootb(ep
, asoc
, type
, arg
, commands
);
1672 return sctp_sf_discard_chunk(ep
, asoc
, type
, arg
, commands
);
1675 /* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A')
1678 * A) In this case, the peer may have restarted.
1680 static sctp_disposition_t
sctp_sf_do_dupcook_a(const struct sctp_endpoint
*ep
,
1681 const struct sctp_association
*asoc
,
1682 struct sctp_chunk
*chunk
,
1683 sctp_cmd_seq_t
*commands
,
1684 struct sctp_association
*new_asoc
)
1686 sctp_init_chunk_t
*peer_init
;
1687 struct sctp_ulpevent
*ev
;
1688 struct sctp_chunk
*repl
;
1689 struct sctp_chunk
*err
;
1690 sctp_disposition_t disposition
;
1692 /* new_asoc is a brand-new association, so these are not yet
1693 * side effects--it is safe to run them here.
1695 peer_init
= &chunk
->subh
.cookie_hdr
->c
.peer_init
[0];
1697 if (!sctp_process_init(new_asoc
, chunk
->chunk_hdr
->type
,
1698 sctp_source(chunk
), peer_init
,
1702 /* Make sure no new addresses are being added during the
1703 * restart. Though this is a pretty complicated attack
1704 * since you'd have to get inside the cookie.
1706 if (!sctp_sf_check_restart_addrs(new_asoc
, asoc
, chunk
, commands
)) {
1707 return SCTP_DISPOSITION_CONSUME
;
1710 /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes
1711 * the peer has restarted (Action A), it MUST NOT setup a new
1712 * association but instead resend the SHUTDOWN ACK and send an ERROR
1713 * chunk with a "Cookie Received while Shutting Down" error cause to
1716 if (sctp_state(asoc
, SHUTDOWN_ACK_SENT
)) {
1717 disposition
= sctp_sf_do_9_2_reshutack(ep
, asoc
,
1718 SCTP_ST_CHUNK(chunk
->chunk_hdr
->type
),
1720 if (SCTP_DISPOSITION_NOMEM
== disposition
)
1723 err
= sctp_make_op_error(asoc
, chunk
,
1724 SCTP_ERROR_COOKIE_IN_SHUTDOWN
,
1727 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
1730 return SCTP_DISPOSITION_CONSUME
;
1733 /* For now, fail any unsent/unacked data. Consider the optional
1734 * choice of resending of this data.
1736 sctp_add_cmd_sf(commands
, SCTP_CMD_PURGE_OUTQUEUE
, SCTP_NULL());
1738 repl
= sctp_make_cookie_ack(new_asoc
, chunk
);
1742 /* Report association restart to upper layer. */
1743 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_RESTART
, 0,
1744 new_asoc
->c
.sinit_num_ostreams
,
1745 new_asoc
->c
.sinit_max_instreams
,
1750 /* Update the content of current association. */
1751 sctp_add_cmd_sf(commands
, SCTP_CMD_UPDATE_ASSOC
, SCTP_ASOC(new_asoc
));
1752 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1753 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
1754 return SCTP_DISPOSITION_CONSUME
;
1757 sctp_chunk_free(repl
);
1759 return SCTP_DISPOSITION_NOMEM
;
1762 /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B')
1765 * B) In this case, both sides may be attempting to start an association
1766 * at about the same time but the peer endpoint started its INIT
1767 * after responding to the local endpoint's INIT
1769 /* This case represents an initialization collision. */
1770 static sctp_disposition_t
sctp_sf_do_dupcook_b(const struct sctp_endpoint
*ep
,
1771 const struct sctp_association
*asoc
,
1772 struct sctp_chunk
*chunk
,
1773 sctp_cmd_seq_t
*commands
,
1774 struct sctp_association
*new_asoc
)
1776 sctp_init_chunk_t
*peer_init
;
1777 struct sctp_chunk
*repl
;
1779 /* new_asoc is a brand-new association, so these are not yet
1780 * side effects--it is safe to run them here.
1782 peer_init
= &chunk
->subh
.cookie_hdr
->c
.peer_init
[0];
1783 if (!sctp_process_init(new_asoc
, chunk
->chunk_hdr
->type
,
1784 sctp_source(chunk
), peer_init
,
1788 /* Update the content of current association. */
1789 sctp_add_cmd_sf(commands
, SCTP_CMD_UPDATE_ASSOC
, SCTP_ASOC(new_asoc
));
1790 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
1791 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
1792 SCTP_INC_STATS(SCTP_MIB_CURRESTAB
);
1793 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_START
, SCTP_NULL());
1795 repl
= sctp_make_cookie_ack(new_asoc
, chunk
);
1799 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1801 /* RFC 2960 5.1 Normal Establishment of an Association
1803 * D) IMPLEMENTATION NOTE: An implementation may choose to
1804 * send the Communication Up notification to the SCTP user
1805 * upon reception of a valid COOKIE ECHO chunk.
1807 * Sadly, this needs to be implemented as a side-effect, because
1808 * we are not guaranteed to have set the association id of the real
1809 * association and so these notifications need to be delayed until
1810 * the association id is allocated.
1813 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_CHANGE
, SCTP_U8(SCTP_COMM_UP
));
1815 /* Sockets API Draft Section 5.3.1.6
1816 * When a peer sends a Adaptation Layer Indication parameter , SCTP
1817 * delivers this notification to inform the application that of the
1818 * peers requested adaptation layer.
1820 * This also needs to be done as a side effect for the same reason as
1823 if (asoc
->peer
.adaptation_ind
)
1824 sctp_add_cmd_sf(commands
, SCTP_CMD_ADAPTATION_IND
, SCTP_NULL());
1826 return SCTP_DISPOSITION_CONSUME
;
1829 return SCTP_DISPOSITION_NOMEM
;
1832 /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C')
1835 * C) In this case, the local endpoint's cookie has arrived late.
1836 * Before it arrived, the local endpoint sent an INIT and received an
1837 * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag
1838 * but a new tag of its own.
1840 /* This case represents an initialization collision. */
1841 static sctp_disposition_t
sctp_sf_do_dupcook_c(const struct sctp_endpoint
*ep
,
1842 const struct sctp_association
*asoc
,
1843 struct sctp_chunk
*chunk
,
1844 sctp_cmd_seq_t
*commands
,
1845 struct sctp_association
*new_asoc
)
1847 /* The cookie should be silently discarded.
1848 * The endpoint SHOULD NOT change states and should leave
1849 * any timers running.
1851 return SCTP_DISPOSITION_DISCARD
;
1854 /* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D')
1858 * D) When both local and remote tags match the endpoint should always
1859 * enter the ESTABLISHED state, if it has not already done so.
1861 /* This case represents an initialization collision. */
1862 static sctp_disposition_t
sctp_sf_do_dupcook_d(const struct sctp_endpoint
*ep
,
1863 const struct sctp_association
*asoc
,
1864 struct sctp_chunk
*chunk
,
1865 sctp_cmd_seq_t
*commands
,
1866 struct sctp_association
*new_asoc
)
1868 struct sctp_ulpevent
*ev
= NULL
, *ai_ev
= NULL
;
1869 struct sctp_chunk
*repl
;
1871 /* Clarification from Implementor's Guide:
1872 * D) When both local and remote tags match the endpoint should
1873 * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state.
1874 * It should stop any cookie timer that may be running and send
1878 /* Don't accidentally move back into established state. */
1879 if (asoc
->state
< SCTP_STATE_ESTABLISHED
) {
1880 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
1881 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
1882 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
1883 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
1884 SCTP_INC_STATS(SCTP_MIB_CURRESTAB
);
1885 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_START
,
1888 /* RFC 2960 5.1 Normal Establishment of an Association
1890 * D) IMPLEMENTATION NOTE: An implementation may choose
1891 * to send the Communication Up notification to the
1892 * SCTP user upon reception of a valid COOKIE
1895 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0,
1897 asoc
->c
.sinit_num_ostreams
,
1898 asoc
->c
.sinit_max_instreams
,
1903 /* Sockets API Draft Section 5.3.1.6
1904 * When a peer sends a Adaptation Layer Indication parameter,
1905 * SCTP delivers this notification to inform the application
1906 * that of the peers requested adaptation layer.
1908 if (asoc
->peer
.adaptation_ind
) {
1909 ai_ev
= sctp_ulpevent_make_adaptation_indication(asoc
,
1917 repl
= sctp_make_cookie_ack(new_asoc
, chunk
);
1921 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1924 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
1927 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
1928 SCTP_ULPEVENT(ai_ev
));
1930 return SCTP_DISPOSITION_CONSUME
;
1934 sctp_ulpevent_free(ai_ev
);
1936 sctp_ulpevent_free(ev
);
1937 return SCTP_DISPOSITION_NOMEM
;
1941 * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying
1942 * chunk was retransmitted and then delayed in the network.
1944 * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists
1946 * Verification Tag: None. Do cookie validation.
1949 * (endpoint, asoc, chunk)
1952 * (asoc, reply_msg, msg_up, timers, counters)
1954 * The return value is the disposition of the chunk.
1956 sctp_disposition_t
sctp_sf_do_5_2_4_dupcook(const struct sctp_endpoint
*ep
,
1957 const struct sctp_association
*asoc
,
1958 const sctp_subtype_t type
,
1960 sctp_cmd_seq_t
*commands
)
1962 sctp_disposition_t retval
;
1963 struct sctp_chunk
*chunk
= arg
;
1964 struct sctp_association
*new_asoc
;
1967 struct sctp_chunk
*err_chk_p
;
1969 /* Make sure that the chunk has a valid length from the protocol
1970 * perspective. In this case check to make sure we have at least
1971 * enough for the chunk header. Cookie length verification is
1974 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
1975 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
1978 /* "Decode" the chunk. We have no optional parameters so we
1979 * are in good shape.
1981 chunk
->subh
.cookie_hdr
= (struct sctp_signed_cookie
*)chunk
->skb
->data
;
1982 if (!pskb_pull(chunk
->skb
, ntohs(chunk
->chunk_hdr
->length
) -
1983 sizeof(sctp_chunkhdr_t
)))
1986 /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
1987 * of a duplicate COOKIE ECHO match the Verification Tags of the
1988 * current association, consider the State Cookie valid even if
1989 * the lifespan is exceeded.
1991 new_asoc
= sctp_unpack_cookie(ep
, asoc
, chunk
, GFP_ATOMIC
, &error
,
1995 * If the re-build failed, what is the proper error path
1998 * [We should abort the association. --piggy]
2001 /* FIXME: Several errors are possible. A bad cookie should
2002 * be silently discarded, but think about logging it too.
2005 case -SCTP_IERROR_NOMEM
:
2008 case -SCTP_IERROR_STALE_COOKIE
:
2009 sctp_send_stale_cookie_err(ep
, asoc
, chunk
, commands
,
2011 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2012 case -SCTP_IERROR_BAD_SIG
:
2014 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2018 /* Compare the tie_tag in cookie with the verification tag of
2019 * current association.
2021 action
= sctp_tietags_compare(new_asoc
, asoc
);
2024 case 'A': /* Association restart. */
2025 retval
= sctp_sf_do_dupcook_a(ep
, asoc
, chunk
, commands
,
2029 case 'B': /* Collision case B. */
2030 retval
= sctp_sf_do_dupcook_b(ep
, asoc
, chunk
, commands
,
2034 case 'C': /* Collision case C. */
2035 retval
= sctp_sf_do_dupcook_c(ep
, asoc
, chunk
, commands
,
2039 case 'D': /* Collision case D. */
2040 retval
= sctp_sf_do_dupcook_d(ep
, asoc
, chunk
, commands
,
2044 default: /* Discard packet for all others. */
2045 retval
= sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2049 /* Delete the tempory new association. */
2050 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(new_asoc
));
2051 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
2056 return SCTP_DISPOSITION_NOMEM
;
2060 * Process an ABORT. (SHUTDOWN-PENDING state)
2062 * See sctp_sf_do_9_1_abort().
2064 sctp_disposition_t
sctp_sf_shutdown_pending_abort(
2065 const struct sctp_endpoint
*ep
,
2066 const struct sctp_association
*asoc
,
2067 const sctp_subtype_t type
,
2069 sctp_cmd_seq_t
*commands
)
2071 struct sctp_chunk
*chunk
= arg
;
2073 if (!sctp_vtag_verify_either(chunk
, asoc
))
2074 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2076 /* Make sure that the ABORT chunk has a valid length.
2077 * Since this is an ABORT chunk, we have to discard it
2078 * because of the following text:
2079 * RFC 2960, Section 3.3.7
2080 * If an endpoint receives an ABORT with a format error or for an
2081 * association that doesn't exist, it MUST silently discard it.
2082 * Because the length is "invalid", we can't really discard just
2083 * as we do not know its true length. So, to be safe, discard the
2086 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_abort_chunk_t
)))
2087 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2089 /* ADD-IP: Special case for ABORT chunks
2090 * F4) One special consideration is that ABORT Chunks arriving
2091 * destined to the IP address being deleted MUST be
2092 * ignored (see Section 5.3.1 for further details).
2094 if (SCTP_ADDR_DEL
==
2095 sctp_bind_addr_state(&asoc
->base
.bind_addr
, &chunk
->dest
))
2096 return sctp_sf_discard_chunk(ep
, asoc
, type
, arg
, commands
);
2098 return __sctp_sf_do_9_1_abort(ep
, asoc
, type
, arg
, commands
);
2102 * Process an ABORT. (SHUTDOWN-SENT state)
2104 * See sctp_sf_do_9_1_abort().
2106 sctp_disposition_t
sctp_sf_shutdown_sent_abort(const struct sctp_endpoint
*ep
,
2107 const struct sctp_association
*asoc
,
2108 const sctp_subtype_t type
,
2110 sctp_cmd_seq_t
*commands
)
2112 struct sctp_chunk
*chunk
= arg
;
2114 if (!sctp_vtag_verify_either(chunk
, asoc
))
2115 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2117 /* Make sure that the ABORT chunk has a valid length.
2118 * Since this is an ABORT chunk, we have to discard it
2119 * because of the following text:
2120 * RFC 2960, Section 3.3.7
2121 * If an endpoint receives an ABORT with a format error or for an
2122 * association that doesn't exist, it MUST silently discard it.
2123 * Because the length is "invalid", we can't really discard just
2124 * as we do not know its true length. So, to be safe, discard the
2127 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_abort_chunk_t
)))
2128 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2130 /* ADD-IP: Special case for ABORT chunks
2131 * F4) One special consideration is that ABORT Chunks arriving
2132 * destined to the IP address being deleted MUST be
2133 * ignored (see Section 5.3.1 for further details).
2135 if (SCTP_ADDR_DEL
==
2136 sctp_bind_addr_state(&asoc
->base
.bind_addr
, &chunk
->dest
))
2137 return sctp_sf_discard_chunk(ep
, asoc
, type
, arg
, commands
);
2139 /* Stop the T2-shutdown timer. */
2140 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
2141 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
2143 /* Stop the T5-shutdown guard timer. */
2144 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
2145 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
2147 return __sctp_sf_do_9_1_abort(ep
, asoc
, type
, arg
, commands
);
2151 * Process an ABORT. (SHUTDOWN-ACK-SENT state)
2153 * See sctp_sf_do_9_1_abort().
2155 sctp_disposition_t
sctp_sf_shutdown_ack_sent_abort(
2156 const struct sctp_endpoint
*ep
,
2157 const struct sctp_association
*asoc
,
2158 const sctp_subtype_t type
,
2160 sctp_cmd_seq_t
*commands
)
2162 /* The same T2 timer, so we should be able to use
2163 * common function with the SHUTDOWN-SENT state.
2165 return sctp_sf_shutdown_sent_abort(ep
, asoc
, type
, arg
, commands
);
2169 * Handle an Error received in COOKIE_ECHOED state.
2171 * Only handle the error type of stale COOKIE Error, the other errors will
2175 * (endpoint, asoc, chunk)
2178 * (asoc, reply_msg, msg_up, timers, counters)
2180 * The return value is the disposition of the chunk.
2182 sctp_disposition_t
sctp_sf_cookie_echoed_err(const struct sctp_endpoint
*ep
,
2183 const struct sctp_association
*asoc
,
2184 const sctp_subtype_t type
,
2186 sctp_cmd_seq_t
*commands
)
2188 struct sctp_chunk
*chunk
= arg
;
2191 if (!sctp_vtag_verify(chunk
, asoc
))
2192 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2194 /* Make sure that the ERROR chunk has a valid length.
2195 * The parameter walking depends on this as well.
2197 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_operr_chunk_t
)))
2198 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2201 /* Process the error here */
2202 /* FUTURE FIXME: When PR-SCTP related and other optional
2203 * parms are emitted, this will have to change to handle multiple
2206 sctp_walk_errors(err
, chunk
->chunk_hdr
) {
2207 if (SCTP_ERROR_STALE_COOKIE
== err
->cause
)
2208 return sctp_sf_do_5_2_6_stale(ep
, asoc
, type
,
2212 /* It is possible to have malformed error causes, and that
2213 * will cause us to end the walk early. However, since
2214 * we are discarding the packet, there should be no adverse
2217 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2221 * Handle a Stale COOKIE Error
2223 * Section: 5.2.6 Handle Stale COOKIE Error
2224 * If the association is in the COOKIE-ECHOED state, the endpoint may elect
2225 * one of the following three alternatives.
2227 * 3) Send a new INIT chunk to the endpoint, adding a Cookie
2228 * Preservative parameter requesting an extension to the lifetime of
2229 * the State Cookie. When calculating the time extension, an
2230 * implementation SHOULD use the RTT information measured based on the
2231 * previous COOKIE ECHO / ERROR exchange, and should add no more
2232 * than 1 second beyond the measured RTT, due to long State Cookie
2233 * lifetimes making the endpoint more subject to a replay attack.
2235 * Verification Tag: Not explicit, but safe to ignore.
2238 * (endpoint, asoc, chunk)
2241 * (asoc, reply_msg, msg_up, timers, counters)
2243 * The return value is the disposition of the chunk.
2245 static sctp_disposition_t
sctp_sf_do_5_2_6_stale(const struct sctp_endpoint
*ep
,
2246 const struct sctp_association
*asoc
,
2247 const sctp_subtype_t type
,
2249 sctp_cmd_seq_t
*commands
)
2251 struct sctp_chunk
*chunk
= arg
;
2253 sctp_cookie_preserve_param_t bht
;
2255 struct sctp_chunk
*reply
;
2256 struct sctp_bind_addr
*bp
;
2257 int attempts
= asoc
->init_err_counter
+ 1;
2259 if (attempts
> asoc
->max_init_attempts
) {
2260 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
2261 SCTP_ERROR(ETIMEDOUT
));
2262 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
2263 SCTP_PERR(SCTP_ERROR_STALE_COOKIE
));
2264 return SCTP_DISPOSITION_DELETE_TCB
;
2267 err
= (sctp_errhdr_t
*)(chunk
->skb
->data
);
2269 /* When calculating the time extension, an implementation
2270 * SHOULD use the RTT information measured based on the
2271 * previous COOKIE ECHO / ERROR exchange, and should add no
2272 * more than 1 second beyond the measured RTT, due to long
2273 * State Cookie lifetimes making the endpoint more subject to
2275 * Measure of Staleness's unit is usec. (1/1000000 sec)
2276 * Suggested Cookie Life-span Increment's unit is msec.
2278 * In general, if you use the suggested cookie life, the value
2279 * found in the field of measure of staleness should be doubled
2280 * to give ample time to retransmit the new cookie and thus
2281 * yield a higher probability of success on the reattempt.
2283 stale
= ntohl(*(__be32
*)((u8
*)err
+ sizeof(sctp_errhdr_t
)));
2284 stale
= (stale
* 2) / 1000;
2286 bht
.param_hdr
.type
= SCTP_PARAM_COOKIE_PRESERVATIVE
;
2287 bht
.param_hdr
.length
= htons(sizeof(bht
));
2288 bht
.lifespan_increment
= htonl(stale
);
2290 /* Build that new INIT chunk. */
2291 bp
= (struct sctp_bind_addr
*) &asoc
->base
.bind_addr
;
2292 reply
= sctp_make_init(asoc
, bp
, GFP_ATOMIC
, sizeof(bht
));
2296 sctp_addto_chunk(reply
, sizeof(bht
), &bht
);
2298 /* Clear peer's init_tag cached in assoc as we are sending a new INIT */
2299 sctp_add_cmd_sf(commands
, SCTP_CMD_CLEAR_INIT_TAG
, SCTP_NULL());
2301 /* Stop pending T3-rtx and heartbeat timers */
2302 sctp_add_cmd_sf(commands
, SCTP_CMD_T3_RTX_TIMERS_STOP
, SCTP_NULL());
2303 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_STOP
, SCTP_NULL());
2305 /* Delete non-primary peer ip addresses since we are transitioning
2306 * back to the COOKIE-WAIT state
2308 sctp_add_cmd_sf(commands
, SCTP_CMD_DEL_NON_PRIMARY
, SCTP_NULL());
2310 /* If we've sent any data bundled with COOKIE-ECHO we will need to
2313 sctp_add_cmd_sf(commands
, SCTP_CMD_T1_RETRAN
,
2314 SCTP_TRANSPORT(asoc
->peer
.primary_path
));
2316 /* Cast away the const modifier, as we want to just
2317 * rerun it through as a sideffect.
2319 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_COUNTER_INC
, SCTP_NULL());
2321 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
2322 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
2323 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
2324 SCTP_STATE(SCTP_STATE_COOKIE_WAIT
));
2325 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
2326 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
2328 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
2330 return SCTP_DISPOSITION_CONSUME
;
2333 return SCTP_DISPOSITION_NOMEM
;
2340 * After checking the Verification Tag, the receiving endpoint shall
2341 * remove the association from its record, and shall report the
2342 * termination to its upper layer.
2344 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
2345 * B) Rules for packet carrying ABORT:
2347 * - The endpoint shall always fill in the Verification Tag field of the
2348 * outbound packet with the destination endpoint's tag value if it
2351 * - If the ABORT is sent in response to an OOTB packet, the endpoint
2352 * MUST follow the procedure described in Section 8.4.
2354 * - The receiver MUST accept the packet if the Verification Tag
2355 * matches either its own tag, OR the tag of its peer. Otherwise, the
2356 * receiver MUST silently discard the packet and take no further
2360 * (endpoint, asoc, chunk)
2363 * (asoc, reply_msg, msg_up, timers, counters)
2365 * The return value is the disposition of the chunk.
2367 sctp_disposition_t
sctp_sf_do_9_1_abort(const struct sctp_endpoint
*ep
,
2368 const struct sctp_association
*asoc
,
2369 const sctp_subtype_t type
,
2371 sctp_cmd_seq_t
*commands
)
2373 struct sctp_chunk
*chunk
= arg
;
2375 if (!sctp_vtag_verify_either(chunk
, asoc
))
2376 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2378 /* Make sure that the ABORT chunk has a valid length.
2379 * Since this is an ABORT chunk, we have to discard it
2380 * because of the following text:
2381 * RFC 2960, Section 3.3.7
2382 * If an endpoint receives an ABORT with a format error or for an
2383 * association that doesn't exist, it MUST silently discard it.
2384 * Because the length is "invalid", we can't really discard just
2385 * as we do not know its true length. So, to be safe, discard the
2388 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_abort_chunk_t
)))
2389 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2391 /* ADD-IP: Special case for ABORT chunks
2392 * F4) One special consideration is that ABORT Chunks arriving
2393 * destined to the IP address being deleted MUST be
2394 * ignored (see Section 5.3.1 for further details).
2396 if (SCTP_ADDR_DEL
==
2397 sctp_bind_addr_state(&asoc
->base
.bind_addr
, &chunk
->dest
))
2398 return sctp_sf_discard_chunk(ep
, asoc
, type
, arg
, commands
);
2400 return __sctp_sf_do_9_1_abort(ep
, asoc
, type
, arg
, commands
);
2403 static sctp_disposition_t
__sctp_sf_do_9_1_abort(const struct sctp_endpoint
*ep
,
2404 const struct sctp_association
*asoc
,
2405 const sctp_subtype_t type
,
2407 sctp_cmd_seq_t
*commands
)
2409 struct sctp_chunk
*chunk
= arg
;
2411 __be16 error
= SCTP_ERROR_NO_ERROR
;
2413 /* See if we have an error cause code in the chunk. */
2414 len
= ntohs(chunk
->chunk_hdr
->length
);
2415 if (len
>= sizeof(struct sctp_chunkhdr
) + sizeof(struct sctp_errhdr
)) {
2418 sctp_walk_errors(err
, chunk
->chunk_hdr
);
2419 if ((void *)err
!= (void *)chunk
->chunk_end
)
2420 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2422 error
= ((sctp_errhdr_t
*)chunk
->skb
->data
)->cause
;
2425 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
, SCTP_ERROR(ECONNRESET
));
2426 /* ASSOC_FAILED will DELETE_TCB. */
2427 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
, SCTP_PERR(error
));
2428 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
2429 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
2431 return SCTP_DISPOSITION_ABORT
;
2435 * Process an ABORT. (COOKIE-WAIT state)
2437 * See sctp_sf_do_9_1_abort() above.
2439 sctp_disposition_t
sctp_sf_cookie_wait_abort(const struct sctp_endpoint
*ep
,
2440 const struct sctp_association
*asoc
,
2441 const sctp_subtype_t type
,
2443 sctp_cmd_seq_t
*commands
)
2445 struct sctp_chunk
*chunk
= arg
;
2447 __be16 error
= SCTP_ERROR_NO_ERROR
;
2449 if (!sctp_vtag_verify_either(chunk
, asoc
))
2450 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2452 /* Make sure that the ABORT chunk has a valid length.
2453 * Since this is an ABORT chunk, we have to discard it
2454 * because of the following text:
2455 * RFC 2960, Section 3.3.7
2456 * If an endpoint receives an ABORT with a format error or for an
2457 * association that doesn't exist, it MUST silently discard it.
2458 * Because the length is "invalid", we can't really discard just
2459 * as we do not know its true length. So, to be safe, discard the
2462 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_abort_chunk_t
)))
2463 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2465 /* See if we have an error cause code in the chunk. */
2466 len
= ntohs(chunk
->chunk_hdr
->length
);
2467 if (len
>= sizeof(struct sctp_chunkhdr
) + sizeof(struct sctp_errhdr
))
2468 error
= ((sctp_errhdr_t
*)chunk
->skb
->data
)->cause
;
2470 return sctp_stop_t1_and_abort(commands
, error
, ECONNREFUSED
, asoc
,
2475 * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state)
2477 sctp_disposition_t
sctp_sf_cookie_wait_icmp_abort(const struct sctp_endpoint
*ep
,
2478 const struct sctp_association
*asoc
,
2479 const sctp_subtype_t type
,
2481 sctp_cmd_seq_t
*commands
)
2483 return sctp_stop_t1_and_abort(commands
, SCTP_ERROR_NO_ERROR
,
2485 (struct sctp_transport
*)arg
);
2489 * Process an ABORT. (COOKIE-ECHOED state)
2491 sctp_disposition_t
sctp_sf_cookie_echoed_abort(const struct sctp_endpoint
*ep
,
2492 const struct sctp_association
*asoc
,
2493 const sctp_subtype_t type
,
2495 sctp_cmd_seq_t
*commands
)
2497 /* There is a single T1 timer, so we should be able to use
2498 * common function with the COOKIE-WAIT state.
2500 return sctp_sf_cookie_wait_abort(ep
, asoc
, type
, arg
, commands
);
2504 * Stop T1 timer and abort association with "INIT failed".
2506 * This is common code called by several sctp_sf_*_abort() functions above.
2508 static sctp_disposition_t
sctp_stop_t1_and_abort(sctp_cmd_seq_t
*commands
,
2509 __be16 error
, int sk_err
,
2510 const struct sctp_association
*asoc
,
2511 struct sctp_transport
*transport
)
2513 SCTP_DEBUG_PRINTK("ABORT received (INIT).\n");
2514 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
2515 SCTP_STATE(SCTP_STATE_CLOSED
));
2516 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
2517 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
2518 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
2519 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
, SCTP_ERROR(sk_err
));
2520 /* CMD_INIT_FAILED will DELETE_TCB. */
2521 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
2523 return SCTP_DISPOSITION_ABORT
;
2527 * sctp_sf_do_9_2_shut
2530 * Upon the reception of the SHUTDOWN, the peer endpoint shall
2531 * - enter the SHUTDOWN-RECEIVED state,
2533 * - stop accepting new data from its SCTP user
2535 * - verify, by checking the Cumulative TSN Ack field of the chunk,
2536 * that all its outstanding DATA chunks have been received by the
2539 * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT
2540 * send a SHUTDOWN in response to a ULP request. And should discard
2541 * subsequent SHUTDOWN chunks.
2543 * If there are still outstanding DATA chunks left, the SHUTDOWN
2544 * receiver shall continue to follow normal data transmission
2545 * procedures defined in Section 6 until all outstanding DATA chunks
2546 * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept
2547 * new data from its SCTP user.
2549 * Verification Tag: 8.5 Verification Tag [Normal verification]
2552 * (endpoint, asoc, chunk)
2555 * (asoc, reply_msg, msg_up, timers, counters)
2557 * The return value is the disposition of the chunk.
2559 sctp_disposition_t
sctp_sf_do_9_2_shutdown(const struct sctp_endpoint
*ep
,
2560 const struct sctp_association
*asoc
,
2561 const sctp_subtype_t type
,
2563 sctp_cmd_seq_t
*commands
)
2565 struct sctp_chunk
*chunk
= arg
;
2566 sctp_shutdownhdr_t
*sdh
;
2567 sctp_disposition_t disposition
;
2568 struct sctp_ulpevent
*ev
;
2571 if (!sctp_vtag_verify(chunk
, asoc
))
2572 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2574 /* Make sure that the SHUTDOWN chunk has a valid length. */
2575 if (!sctp_chunk_length_valid(chunk
,
2576 sizeof(struct sctp_shutdown_chunk_t
)))
2577 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2580 /* Convert the elaborate header. */
2581 sdh
= (sctp_shutdownhdr_t
*)chunk
->skb
->data
;
2582 skb_pull(chunk
->skb
, sizeof(sctp_shutdownhdr_t
));
2583 chunk
->subh
.shutdown_hdr
= sdh
;
2584 ctsn
= ntohl(sdh
->cum_tsn_ack
);
2586 if (TSN_lt(ctsn
, asoc
->ctsn_ack_point
)) {
2587 SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn
);
2588 SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc
->ctsn_ack_point
);
2589 return SCTP_DISPOSITION_DISCARD
;
2592 /* If Cumulative TSN Ack beyond the max tsn currently
2593 * send, terminating the association and respond to the
2594 * sender with an ABORT.
2596 if (!TSN_lt(ctsn
, asoc
->next_tsn
))
2597 return sctp_sf_violation_ctsn(ep
, asoc
, type
, arg
, commands
);
2599 /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT
2600 * When a peer sends a SHUTDOWN, SCTP delivers this notification to
2601 * inform the application that it should cease sending data.
2603 ev
= sctp_ulpevent_make_shutdown_event(asoc
, 0, GFP_ATOMIC
);
2605 disposition
= SCTP_DISPOSITION_NOMEM
;
2608 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
2610 /* Upon the reception of the SHUTDOWN, the peer endpoint shall
2611 * - enter the SHUTDOWN-RECEIVED state,
2612 * - stop accepting new data from its SCTP user
2614 * [This is implicit in the new state.]
2616 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
2617 SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED
));
2618 disposition
= SCTP_DISPOSITION_CONSUME
;
2620 if (sctp_outq_is_empty(&asoc
->outqueue
)) {
2621 disposition
= sctp_sf_do_9_2_shutdown_ack(ep
, asoc
, type
,
2625 if (SCTP_DISPOSITION_NOMEM
== disposition
)
2628 /* - verify, by checking the Cumulative TSN Ack field of the
2629 * chunk, that all its outstanding DATA chunks have been
2630 * received by the SHUTDOWN sender.
2632 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_CTSN
,
2633 SCTP_BE32(chunk
->subh
.shutdown_hdr
->cum_tsn_ack
));
2640 * sctp_sf_do_9_2_shut_ctsn
2642 * Once an endpoint has reached the SHUTDOWN-RECEIVED state,
2643 * it MUST NOT send a SHUTDOWN in response to a ULP request.
2644 * The Cumulative TSN Ack of the received SHUTDOWN chunk
2645 * MUST be processed.
2647 sctp_disposition_t
sctp_sf_do_9_2_shut_ctsn(const struct sctp_endpoint
*ep
,
2648 const struct sctp_association
*asoc
,
2649 const sctp_subtype_t type
,
2651 sctp_cmd_seq_t
*commands
)
2653 struct sctp_chunk
*chunk
= arg
;
2654 sctp_shutdownhdr_t
*sdh
;
2657 if (!sctp_vtag_verify(chunk
, asoc
))
2658 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2660 /* Make sure that the SHUTDOWN chunk has a valid length. */
2661 if (!sctp_chunk_length_valid(chunk
,
2662 sizeof(struct sctp_shutdown_chunk_t
)))
2663 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2666 sdh
= (sctp_shutdownhdr_t
*)chunk
->skb
->data
;
2667 ctsn
= ntohl(sdh
->cum_tsn_ack
);
2669 if (TSN_lt(ctsn
, asoc
->ctsn_ack_point
)) {
2670 SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn
);
2671 SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc
->ctsn_ack_point
);
2672 return SCTP_DISPOSITION_DISCARD
;
2675 /* If Cumulative TSN Ack beyond the max tsn currently
2676 * send, terminating the association and respond to the
2677 * sender with an ABORT.
2679 if (!TSN_lt(ctsn
, asoc
->next_tsn
))
2680 return sctp_sf_violation_ctsn(ep
, asoc
, type
, arg
, commands
);
2682 /* verify, by checking the Cumulative TSN Ack field of the
2683 * chunk, that all its outstanding DATA chunks have been
2684 * received by the SHUTDOWN sender.
2686 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_CTSN
,
2687 SCTP_BE32(sdh
->cum_tsn_ack
));
2689 return SCTP_DISPOSITION_CONSUME
;
2693 * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk
2694 * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination
2695 * transport addresses (either in the IP addresses or in the INIT chunk)
2696 * that belong to this association, it should discard the INIT chunk and
2697 * retransmit the SHUTDOWN ACK chunk.
2699 sctp_disposition_t
sctp_sf_do_9_2_reshutack(const struct sctp_endpoint
*ep
,
2700 const struct sctp_association
*asoc
,
2701 const sctp_subtype_t type
,
2703 sctp_cmd_seq_t
*commands
)
2705 struct sctp_chunk
*chunk
= (struct sctp_chunk
*) arg
;
2706 struct sctp_chunk
*reply
;
2708 /* Make sure that the chunk has a valid length */
2709 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
2710 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2713 /* Since we are not going to really process this INIT, there
2714 * is no point in verifying chunk boundries. Just generate
2717 reply
= sctp_make_shutdown_ack(asoc
, chunk
);
2721 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
2722 * the T2-SHUTDOWN timer.
2724 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T2
, SCTP_CHUNK(reply
));
2726 /* and restart the T2-shutdown timer. */
2727 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
2728 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
2730 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
2732 return SCTP_DISPOSITION_CONSUME
;
2734 return SCTP_DISPOSITION_NOMEM
;
2738 * sctp_sf_do_ecn_cwr
2740 * Section: Appendix A: Explicit Congestion Notification
2744 * RFC 2481 details a specific bit for a sender to send in the header of
2745 * its next outbound TCP segment to indicate to its peer that it has
2746 * reduced its congestion window. This is termed the CWR bit. For
2747 * SCTP the same indication is made by including the CWR chunk.
2748 * This chunk contains one data element, i.e. the TSN number that
2749 * was sent in the ECNE chunk. This element represents the lowest
2750 * TSN number in the datagram that was originally marked with the
2753 * Verification Tag: 8.5 Verification Tag [Normal verification]
2755 * (endpoint, asoc, chunk)
2758 * (asoc, reply_msg, msg_up, timers, counters)
2760 * The return value is the disposition of the chunk.
2762 sctp_disposition_t
sctp_sf_do_ecn_cwr(const struct sctp_endpoint
*ep
,
2763 const struct sctp_association
*asoc
,
2764 const sctp_subtype_t type
,
2766 sctp_cmd_seq_t
*commands
)
2769 struct sctp_chunk
*chunk
= arg
;
2772 if (!sctp_vtag_verify(chunk
, asoc
))
2773 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2775 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_ecne_chunk_t
)))
2776 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2779 cwr
= (sctp_cwrhdr_t
*) chunk
->skb
->data
;
2780 skb_pull(chunk
->skb
, sizeof(sctp_cwrhdr_t
));
2782 lowest_tsn
= ntohl(cwr
->lowest_tsn
);
2784 /* Does this CWR ack the last sent congestion notification? */
2785 if (TSN_lte(asoc
->last_ecne_tsn
, lowest_tsn
)) {
2786 /* Stop sending ECNE. */
2787 sctp_add_cmd_sf(commands
,
2789 SCTP_U32(lowest_tsn
));
2791 return SCTP_DISPOSITION_CONSUME
;
2797 * Section: Appendix A: Explicit Congestion Notification
2801 * RFC 2481 details a specific bit for a receiver to send back in its
2802 * TCP acknowledgements to notify the sender of the Congestion
2803 * Experienced (CE) bit having arrived from the network. For SCTP this
2804 * same indication is made by including the ECNE chunk. This chunk
2805 * contains one data element, i.e. the lowest TSN associated with the IP
2806 * datagram marked with the CE bit.....
2808 * Verification Tag: 8.5 Verification Tag [Normal verification]
2810 * (endpoint, asoc, chunk)
2813 * (asoc, reply_msg, msg_up, timers, counters)
2815 * The return value is the disposition of the chunk.
2817 sctp_disposition_t
sctp_sf_do_ecne(const struct sctp_endpoint
*ep
,
2818 const struct sctp_association
*asoc
,
2819 const sctp_subtype_t type
,
2821 sctp_cmd_seq_t
*commands
)
2823 sctp_ecnehdr_t
*ecne
;
2824 struct sctp_chunk
*chunk
= arg
;
2826 if (!sctp_vtag_verify(chunk
, asoc
))
2827 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2829 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_ecne_chunk_t
)))
2830 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2833 ecne
= (sctp_ecnehdr_t
*) chunk
->skb
->data
;
2834 skb_pull(chunk
->skb
, sizeof(sctp_ecnehdr_t
));
2836 /* If this is a newer ECNE than the last CWR packet we sent out */
2837 sctp_add_cmd_sf(commands
, SCTP_CMD_ECN_ECNE
,
2838 SCTP_U32(ntohl(ecne
->lowest_tsn
)));
2840 return SCTP_DISPOSITION_CONSUME
;
2844 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
2846 * The SCTP endpoint MUST always acknowledge the reception of each valid
2849 * The guidelines on delayed acknowledgement algorithm specified in
2850 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
2851 * acknowledgement SHOULD be generated for at least every second packet
2852 * (not every second DATA chunk) received, and SHOULD be generated within
2853 * 200 ms of the arrival of any unacknowledged DATA chunk. In some
2854 * situations it may be beneficial for an SCTP transmitter to be more
2855 * conservative than the algorithms detailed in this document allow.
2856 * However, an SCTP transmitter MUST NOT be more aggressive than the
2857 * following algorithms allow.
2859 * A SCTP receiver MUST NOT generate more than one SACK for every
2860 * incoming packet, other than to update the offered window as the
2861 * receiving application consumes new data.
2863 * Verification Tag: 8.5 Verification Tag [Normal verification]
2866 * (endpoint, asoc, chunk)
2869 * (asoc, reply_msg, msg_up, timers, counters)
2871 * The return value is the disposition of the chunk.
2873 sctp_disposition_t
sctp_sf_eat_data_6_2(const struct sctp_endpoint
*ep
,
2874 const struct sctp_association
*asoc
,
2875 const sctp_subtype_t type
,
2877 sctp_cmd_seq_t
*commands
)
2879 struct sctp_chunk
*chunk
= arg
;
2880 sctp_arg_t force
= SCTP_NOFORCE();
2883 if (!sctp_vtag_verify(chunk
, asoc
)) {
2884 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
2886 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2889 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_data_chunk_t
)))
2890 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2893 error
= sctp_eat_data(asoc
, chunk
, commands
);
2895 case SCTP_IERROR_NO_ERROR
:
2897 case SCTP_IERROR_HIGH_TSN
:
2898 case SCTP_IERROR_BAD_STREAM
:
2899 SCTP_INC_STATS(SCTP_MIB_IN_DATA_CHUNK_DISCARDS
);
2900 goto discard_noforce
;
2901 case SCTP_IERROR_DUP_TSN
:
2902 case SCTP_IERROR_IGNORE_TSN
:
2903 SCTP_INC_STATS(SCTP_MIB_IN_DATA_CHUNK_DISCARDS
);
2905 case SCTP_IERROR_NO_DATA
:
2907 case SCTP_IERROR_PROTO_VIOLATION
:
2908 return sctp_sf_abort_violation(ep
, asoc
, chunk
, commands
,
2909 (u8
*)chunk
->subh
.data_hdr
, sizeof(sctp_datahdr_t
));
2914 if (chunk
->chunk_hdr
->flags
& SCTP_DATA_SACK_IMM
)
2915 force
= SCTP_FORCE();
2917 if (asoc
->autoclose
) {
2918 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
2919 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
2922 /* If this is the last chunk in a packet, we need to count it
2923 * toward sack generation. Note that we need to SACK every
2924 * OTHER packet containing data chunks, EVEN IF WE DISCARD
2925 * THEM. We elect to NOT generate SACK's if the chunk fails
2926 * the verification tag test.
2928 * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2930 * The SCTP endpoint MUST always acknowledge the reception of
2931 * each valid DATA chunk.
2933 * The guidelines on delayed acknowledgement algorithm
2934 * specified in Section 4.2 of [RFC2581] SHOULD be followed.
2935 * Specifically, an acknowledgement SHOULD be generated for at
2936 * least every second packet (not every second DATA chunk)
2937 * received, and SHOULD be generated within 200 ms of the
2938 * arrival of any unacknowledged DATA chunk. In some
2939 * situations it may be beneficial for an SCTP transmitter to
2940 * be more conservative than the algorithms detailed in this
2941 * document allow. However, an SCTP transmitter MUST NOT be
2942 * more aggressive than the following algorithms allow.
2944 if (chunk
->end_of_packet
)
2945 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, force
);
2947 return SCTP_DISPOSITION_CONSUME
;
2950 /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2952 * When a packet arrives with duplicate DATA chunk(s) and with
2953 * no new DATA chunk(s), the endpoint MUST immediately send a
2954 * SACK with no delay. If a packet arrives with duplicate
2955 * DATA chunk(s) bundled with new DATA chunks, the endpoint
2956 * MAY immediately send a SACK. Normally receipt of duplicate
2957 * DATA chunks will occur when the original SACK chunk was lost
2958 * and the peer's RTO has expired. The duplicate TSN number(s)
2959 * SHOULD be reported in the SACK as duplicate.
2961 /* In our case, we split the MAY SACK advice up whether or not
2962 * the last chunk is a duplicate.'
2964 if (chunk
->end_of_packet
)
2965 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_FORCE());
2966 return SCTP_DISPOSITION_DISCARD
;
2969 if (chunk
->end_of_packet
)
2970 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, force
);
2972 return SCTP_DISPOSITION_DISCARD
;
2974 return SCTP_DISPOSITION_CONSUME
;
2979 * sctp_sf_eat_data_fast_4_4
2982 * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received
2983 * DATA chunks without delay.
2985 * Verification Tag: 8.5 Verification Tag [Normal verification]
2987 * (endpoint, asoc, chunk)
2990 * (asoc, reply_msg, msg_up, timers, counters)
2992 * The return value is the disposition of the chunk.
2994 sctp_disposition_t
sctp_sf_eat_data_fast_4_4(const struct sctp_endpoint
*ep
,
2995 const struct sctp_association
*asoc
,
2996 const sctp_subtype_t type
,
2998 sctp_cmd_seq_t
*commands
)
3000 struct sctp_chunk
*chunk
= arg
;
3003 if (!sctp_vtag_verify(chunk
, asoc
)) {
3004 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3006 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3009 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_data_chunk_t
)))
3010 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3013 error
= sctp_eat_data(asoc
, chunk
, commands
);
3015 case SCTP_IERROR_NO_ERROR
:
3016 case SCTP_IERROR_HIGH_TSN
:
3017 case SCTP_IERROR_DUP_TSN
:
3018 case SCTP_IERROR_IGNORE_TSN
:
3019 case SCTP_IERROR_BAD_STREAM
:
3021 case SCTP_IERROR_NO_DATA
:
3023 case SCTP_IERROR_PROTO_VIOLATION
:
3024 return sctp_sf_abort_violation(ep
, asoc
, chunk
, commands
,
3025 (u8
*)chunk
->subh
.data_hdr
, sizeof(sctp_datahdr_t
));
3030 /* Go a head and force a SACK, since we are shutting down. */
3032 /* Implementor's Guide.
3034 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3035 * respond to each received packet containing one or more DATA chunk(s)
3036 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3038 if (chunk
->end_of_packet
) {
3039 /* We must delay the chunk creation since the cumulative
3040 * TSN has not been updated yet.
3042 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SHUTDOWN
, SCTP_NULL());
3043 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_FORCE());
3044 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
3045 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
3049 return SCTP_DISPOSITION_CONSUME
;
3053 * Section: 6.2 Processing a Received SACK
3054 * D) Any time a SACK arrives, the endpoint performs the following:
3056 * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point,
3057 * then drop the SACK. Since Cumulative TSN Ack is monotonically
3058 * increasing, a SACK whose Cumulative TSN Ack is less than the
3059 * Cumulative TSN Ack Point indicates an out-of-order SACK.
3061 * ii) Set rwnd equal to the newly received a_rwnd minus the number
3062 * of bytes still outstanding after processing the Cumulative TSN Ack
3063 * and the Gap Ack Blocks.
3065 * iii) If the SACK is missing a TSN that was previously
3066 * acknowledged via a Gap Ack Block (e.g., the data receiver
3067 * reneged on the data), then mark the corresponding DATA chunk
3068 * as available for retransmit: Mark it as missing for fast
3069 * retransmit as described in Section 7.2.4 and if no retransmit
3070 * timer is running for the destination address to which the DATA
3071 * chunk was originally transmitted, then T3-rtx is started for
3072 * that destination address.
3074 * Verification Tag: 8.5 Verification Tag [Normal verification]
3077 * (endpoint, asoc, chunk)
3080 * (asoc, reply_msg, msg_up, timers, counters)
3082 * The return value is the disposition of the chunk.
3084 sctp_disposition_t
sctp_sf_eat_sack_6_2(const struct sctp_endpoint
*ep
,
3085 const struct sctp_association
*asoc
,
3086 const sctp_subtype_t type
,
3088 sctp_cmd_seq_t
*commands
)
3090 struct sctp_chunk
*chunk
= arg
;
3091 sctp_sackhdr_t
*sackh
;
3094 if (!sctp_vtag_verify(chunk
, asoc
))
3095 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3097 /* Make sure that the SACK chunk has a valid length. */
3098 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_sack_chunk_t
)))
3099 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3102 /* Pull the SACK chunk from the data buffer */
3103 sackh
= sctp_sm_pull_sack(chunk
);
3104 /* Was this a bogus SACK? */
3106 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3107 chunk
->subh
.sack_hdr
= sackh
;
3108 ctsn
= ntohl(sackh
->cum_tsn_ack
);
3110 /* i) If Cumulative TSN Ack is less than the Cumulative TSN
3111 * Ack Point, then drop the SACK. Since Cumulative TSN
3112 * Ack is monotonically increasing, a SACK whose
3113 * Cumulative TSN Ack is less than the Cumulative TSN Ack
3114 * Point indicates an out-of-order SACK.
3116 if (TSN_lt(ctsn
, asoc
->ctsn_ack_point
)) {
3117 SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn
);
3118 SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc
->ctsn_ack_point
);
3119 return SCTP_DISPOSITION_DISCARD
;
3122 /* If Cumulative TSN Ack beyond the max tsn currently
3123 * send, terminating the association and respond to the
3124 * sender with an ABORT.
3126 if (!TSN_lt(ctsn
, asoc
->next_tsn
))
3127 return sctp_sf_violation_ctsn(ep
, asoc
, type
, arg
, commands
);
3129 /* Return this SACK for further processing. */
3130 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_SACK
, SCTP_SACKH(sackh
));
3132 /* Note: We do the rest of the work on the PROCESS_SACK
3135 return SCTP_DISPOSITION_CONSUME
;
3139 * Generate an ABORT in response to a packet.
3141 * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41
3143 * 8) The receiver should respond to the sender of the OOTB packet with
3144 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3145 * MUST fill in the Verification Tag field of the outbound packet
3146 * with the value found in the Verification Tag field of the OOTB
3147 * packet and set the T-bit in the Chunk Flags to indicate that the
3148 * Verification Tag is reflected. After sending this ABORT, the
3149 * receiver of the OOTB packet shall discard the OOTB packet and take
3150 * no further action.
3154 * The return value is the disposition of the chunk.
3156 static sctp_disposition_t
sctp_sf_tabort_8_4_8(const struct sctp_endpoint
*ep
,
3157 const struct sctp_association
*asoc
,
3158 const sctp_subtype_t type
,
3160 sctp_cmd_seq_t
*commands
)
3162 struct sctp_packet
*packet
= NULL
;
3163 struct sctp_chunk
*chunk
= arg
;
3164 struct sctp_chunk
*abort
;
3166 packet
= sctp_ootb_pkt_new(asoc
, chunk
);
3169 /* Make an ABORT. The T bit will be set if the asoc
3172 abort
= sctp_make_abort(asoc
, chunk
, 0);
3174 sctp_ootb_pkt_free(packet
);
3175 return SCTP_DISPOSITION_NOMEM
;
3178 /* Reflect vtag if T-Bit is set */
3179 if (sctp_test_T_bit(abort
))
3180 packet
->vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
3182 /* Set the skb to the belonging sock for accounting. */
3183 abort
->skb
->sk
= ep
->base
.sk
;
3185 sctp_packet_append_chunk(packet
, abort
);
3187 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
3188 SCTP_PACKET(packet
));
3190 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
3192 sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3193 return SCTP_DISPOSITION_CONSUME
;
3196 return SCTP_DISPOSITION_NOMEM
;
3200 * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR
3201 * event as ULP notification for each cause included in the chunk.
3203 * API 5.3.1.3 - SCTP_REMOTE_ERROR
3205 * The return value is the disposition of the chunk.
3207 sctp_disposition_t
sctp_sf_operr_notify(const struct sctp_endpoint
*ep
,
3208 const struct sctp_association
*asoc
,
3209 const sctp_subtype_t type
,
3211 sctp_cmd_seq_t
*commands
)
3213 struct sctp_chunk
*chunk
= arg
;
3216 if (!sctp_vtag_verify(chunk
, asoc
))
3217 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3219 /* Make sure that the ERROR chunk has a valid length. */
3220 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_operr_chunk_t
)))
3221 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3223 sctp_walk_errors(err
, chunk
->chunk_hdr
);
3224 if ((void *)err
!= (void *)chunk
->chunk_end
)
3225 return sctp_sf_violation_paramlen(ep
, asoc
, type
, arg
,
3226 (void *)err
, commands
);
3228 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_OPERR
,
3231 return SCTP_DISPOSITION_CONSUME
;
3235 * Process an inbound SHUTDOWN ACK.
3238 * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3239 * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its
3240 * peer, and remove all record of the association.
3242 * The return value is the disposition.
3244 sctp_disposition_t
sctp_sf_do_9_2_final(const struct sctp_endpoint
*ep
,
3245 const struct sctp_association
*asoc
,
3246 const sctp_subtype_t type
,
3248 sctp_cmd_seq_t
*commands
)
3250 struct sctp_chunk
*chunk
= arg
;
3251 struct sctp_chunk
*reply
;
3252 struct sctp_ulpevent
*ev
;
3254 if (!sctp_vtag_verify(chunk
, asoc
))
3255 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3257 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3258 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
3259 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3261 /* 10.2 H) SHUTDOWN COMPLETE notification
3263 * When SCTP completes the shutdown procedures (section 9.2) this
3264 * notification is passed to the upper layer.
3266 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_SHUTDOWN_COMP
,
3267 0, 0, 0, NULL
, GFP_ATOMIC
);
3271 /* ...send a SHUTDOWN COMPLETE chunk to its peer, */
3272 reply
= sctp_make_shutdown_complete(asoc
, chunk
);
3276 /* Do all the commands now (after allocation), so that we
3277 * have consistent state if memory allocation failes
3279 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
3281 /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3282 * stop the T2-shutdown timer,
3284 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3285 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
3287 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3288 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
3290 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
3291 SCTP_STATE(SCTP_STATE_CLOSED
));
3292 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS
);
3293 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
3294 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
3296 /* ...and remove all record of the association. */
3297 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
3298 return SCTP_DISPOSITION_DELETE_TCB
;
3301 sctp_ulpevent_free(ev
);
3303 return SCTP_DISPOSITION_NOMEM
;
3307 * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41.
3309 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3310 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3311 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3312 * packet must fill in the Verification Tag field of the outbound
3313 * packet with the Verification Tag received in the SHUTDOWN ACK and
3314 * set the T-bit in the Chunk Flags to indicate that the Verification
3317 * 8) The receiver should respond to the sender of the OOTB packet with
3318 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3319 * MUST fill in the Verification Tag field of the outbound packet
3320 * with the value found in the Verification Tag field of the OOTB
3321 * packet and set the T-bit in the Chunk Flags to indicate that the
3322 * Verification Tag is reflected. After sending this ABORT, the
3323 * receiver of the OOTB packet shall discard the OOTB packet and take
3324 * no further action.
3326 sctp_disposition_t
sctp_sf_ootb(const struct sctp_endpoint
*ep
,
3327 const struct sctp_association
*asoc
,
3328 const sctp_subtype_t type
,
3330 sctp_cmd_seq_t
*commands
)
3332 struct sctp_chunk
*chunk
= arg
;
3333 struct sk_buff
*skb
= chunk
->skb
;
3334 sctp_chunkhdr_t
*ch
;
3336 int ootb_shut_ack
= 0;
3338 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES
);
3340 ch
= (sctp_chunkhdr_t
*) chunk
->chunk_hdr
;
3342 /* Report violation if the chunk is less then minimal */
3343 if (ntohs(ch
->length
) < sizeof(sctp_chunkhdr_t
))
3344 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3347 /* Now that we know we at least have a chunk header,
3348 * do things that are type appropriate.
3350 if (SCTP_CID_SHUTDOWN_ACK
== ch
->type
)
3353 /* RFC 2960, Section 3.3.7
3354 * Moreover, under any circumstances, an endpoint that
3355 * receives an ABORT MUST NOT respond to that ABORT by
3356 * sending an ABORT of its own.
3358 if (SCTP_CID_ABORT
== ch
->type
)
3359 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3361 /* Report violation if chunk len overflows */
3362 ch_end
= ((__u8
*)ch
) + WORD_ROUND(ntohs(ch
->length
));
3363 if (ch_end
> skb_tail_pointer(skb
))
3364 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3367 ch
= (sctp_chunkhdr_t
*) ch_end
;
3368 } while (ch_end
< skb_tail_pointer(skb
));
3371 return sctp_sf_shut_8_4_5(ep
, asoc
, type
, arg
, commands
);
3373 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
, commands
);
3377 * Handle an "Out of the blue" SHUTDOWN ACK.
3379 * Section: 8.4 5, sctpimpguide 2.41.
3381 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3382 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3383 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3384 * packet must fill in the Verification Tag field of the outbound
3385 * packet with the Verification Tag received in the SHUTDOWN ACK and
3386 * set the T-bit in the Chunk Flags to indicate that the Verification
3390 * (endpoint, asoc, type, arg, commands)
3393 * (sctp_disposition_t)
3395 * The return value is the disposition of the chunk.
3397 static sctp_disposition_t
sctp_sf_shut_8_4_5(const struct sctp_endpoint
*ep
,
3398 const struct sctp_association
*asoc
,
3399 const sctp_subtype_t type
,
3401 sctp_cmd_seq_t
*commands
)
3403 struct sctp_packet
*packet
= NULL
;
3404 struct sctp_chunk
*chunk
= arg
;
3405 struct sctp_chunk
*shut
;
3407 packet
= sctp_ootb_pkt_new(asoc
, chunk
);
3410 /* Make an SHUTDOWN_COMPLETE.
3411 * The T bit will be set if the asoc is NULL.
3413 shut
= sctp_make_shutdown_complete(asoc
, chunk
);
3415 sctp_ootb_pkt_free(packet
);
3416 return SCTP_DISPOSITION_NOMEM
;
3419 /* Reflect vtag if T-Bit is set */
3420 if (sctp_test_T_bit(shut
))
3421 packet
->vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
3423 /* Set the skb to the belonging sock for accounting. */
3424 shut
->skb
->sk
= ep
->base
.sk
;
3426 sctp_packet_append_chunk(packet
, shut
);
3428 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
3429 SCTP_PACKET(packet
));
3431 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
3433 /* If the chunk length is invalid, we don't want to process
3434 * the reset of the packet.
3436 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
3437 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3439 /* We need to discard the rest of the packet to prevent
3440 * potential bomming attacks from additional bundled chunks.
3441 * This is documented in SCTP Threats ID.
3443 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3446 return SCTP_DISPOSITION_NOMEM
;
3450 * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state.
3452 * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK
3453 * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the
3454 * procedures in section 8.4 SHOULD be followed, in other words it
3455 * should be treated as an Out Of The Blue packet.
3456 * [This means that we do NOT check the Verification Tag on these
3460 sctp_disposition_t
sctp_sf_do_8_5_1_E_sa(const struct sctp_endpoint
*ep
,
3461 const struct sctp_association
*asoc
,
3462 const sctp_subtype_t type
,
3464 sctp_cmd_seq_t
*commands
)
3466 struct sctp_chunk
*chunk
= arg
;
3468 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3469 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
3470 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3473 /* Although we do have an association in this case, it corresponds
3474 * to a restarted association. So the packet is treated as an OOTB
3475 * packet and the state function that handles OOTB SHUTDOWN_ACK is
3476 * called with a NULL association.
3478 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES
);
3480 return sctp_sf_shut_8_4_5(ep
, NULL
, type
, arg
, commands
);
3483 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */
3484 sctp_disposition_t
sctp_sf_do_asconf(const struct sctp_endpoint
*ep
,
3485 const struct sctp_association
*asoc
,
3486 const sctp_subtype_t type
, void *arg
,
3487 sctp_cmd_seq_t
*commands
)
3489 struct sctp_chunk
*chunk
= arg
;
3490 struct sctp_chunk
*asconf_ack
= NULL
;
3491 struct sctp_paramhdr
*err_param
= NULL
;
3492 sctp_addiphdr_t
*hdr
;
3493 union sctp_addr_param
*addr_param
;
3497 if (!sctp_vtag_verify(chunk
, asoc
)) {
3498 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3500 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3503 /* ADD-IP: Section 4.1.1
3504 * This chunk MUST be sent in an authenticated way by using
3505 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3506 * is received unauthenticated it MUST be silently discarded as
3507 * described in [I-D.ietf-tsvwg-sctp-auth].
3509 if (!sctp_addip_noauth
&& !chunk
->auth
)
3510 return sctp_sf_discard_chunk(ep
, asoc
, type
, arg
, commands
);
3512 /* Make sure that the ASCONF ADDIP chunk has a valid length. */
3513 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_addip_chunk_t
)))
3514 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3517 hdr
= (sctp_addiphdr_t
*)chunk
->skb
->data
;
3518 serial
= ntohl(hdr
->serial
);
3520 addr_param
= (union sctp_addr_param
*)hdr
->params
;
3521 length
= ntohs(addr_param
->p
.length
);
3522 if (length
< sizeof(sctp_paramhdr_t
))
3523 return sctp_sf_violation_paramlen(ep
, asoc
, type
, arg
,
3524 (void *)addr_param
, commands
);
3526 /* Verify the ASCONF chunk before processing it. */
3527 if (!sctp_verify_asconf(asoc
,
3528 (sctp_paramhdr_t
*)((void *)addr_param
+ length
),
3529 (void *)chunk
->chunk_end
,
3531 return sctp_sf_violation_paramlen(ep
, asoc
, type
, arg
,
3532 (void *)err_param
, commands
);
3534 /* ADDIP 5.2 E1) Compare the value of the serial number to the value
3535 * the endpoint stored in a new association variable
3536 * 'Peer-Serial-Number'.
3538 if (serial
== asoc
->peer
.addip_serial
+ 1) {
3539 /* If this is the first instance of ASCONF in the packet,
3540 * we can clean our old ASCONF-ACKs.
3542 if (!chunk
->has_asconf
)
3543 sctp_assoc_clean_asconf_ack_cache(asoc
);
3545 /* ADDIP 5.2 E4) When the Sequence Number matches the next one
3546 * expected, process the ASCONF as described below and after
3547 * processing the ASCONF Chunk, append an ASCONF-ACK Chunk to
3548 * the response packet and cache a copy of it (in the event it
3549 * later needs to be retransmitted).
3551 * Essentially, do V1-V5.
3553 asconf_ack
= sctp_process_asconf((struct sctp_association
*)
3556 return SCTP_DISPOSITION_NOMEM
;
3557 } else if (serial
< asoc
->peer
.addip_serial
+ 1) {
3559 * If the value found in the Sequence Number is less than the
3560 * ('Peer- Sequence-Number' + 1), simply skip to the next
3561 * ASCONF, and include in the outbound response packet
3562 * any previously cached ASCONF-ACK response that was
3563 * sent and saved that matches the Sequence Number of the
3564 * ASCONF. Note: It is possible that no cached ASCONF-ACK
3565 * Chunk exists. This will occur when an older ASCONF
3566 * arrives out of order. In such a case, the receiver
3567 * should skip the ASCONF Chunk and not include ASCONF-ACK
3568 * Chunk for that chunk.
3570 asconf_ack
= sctp_assoc_lookup_asconf_ack(asoc
, hdr
->serial
);
3572 return SCTP_DISPOSITION_DISCARD
;
3574 /* Reset the transport so that we select the correct one
3575 * this time around. This is to make sure that we don't
3576 * accidentally use a stale transport that's been removed.
3578 asconf_ack
->transport
= NULL
;
3580 /* ADDIP 5.2 E5) Otherwise, the ASCONF Chunk is discarded since
3581 * it must be either a stale packet or from an attacker.
3583 return SCTP_DISPOSITION_DISCARD
;
3586 /* ADDIP 5.2 E6) The destination address of the SCTP packet
3587 * containing the ASCONF-ACK Chunks MUST be the source address of
3588 * the SCTP packet that held the ASCONF Chunks.
3590 * To do this properly, we'll set the destination address of the chunk
3591 * and at the transmit time, will try look up the transport to use.
3592 * Since ASCONFs may be bundled, the correct transport may not be
3593 * created until we process the entire packet, thus this workaround.
3595 asconf_ack
->dest
= chunk
->source
;
3596 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(asconf_ack
));
3598 return SCTP_DISPOSITION_CONSUME
;
3602 * ADDIP Section 4.3 General rules for address manipulation
3603 * When building TLV parameters for the ASCONF Chunk that will add or
3604 * delete IP addresses the D0 to D13 rules should be applied:
3606 sctp_disposition_t
sctp_sf_do_asconf_ack(const struct sctp_endpoint
*ep
,
3607 const struct sctp_association
*asoc
,
3608 const sctp_subtype_t type
, void *arg
,
3609 sctp_cmd_seq_t
*commands
)
3611 struct sctp_chunk
*asconf_ack
= arg
;
3612 struct sctp_chunk
*last_asconf
= asoc
->addip_last_asconf
;
3613 struct sctp_chunk
*abort
;
3614 struct sctp_paramhdr
*err_param
= NULL
;
3615 sctp_addiphdr_t
*addip_hdr
;
3616 __u32 sent_serial
, rcvd_serial
;
3618 if (!sctp_vtag_verify(asconf_ack
, asoc
)) {
3619 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3621 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3624 /* ADD-IP, Section 4.1.2:
3625 * This chunk MUST be sent in an authenticated way by using
3626 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3627 * is received unauthenticated it MUST be silently discarded as
3628 * described in [I-D.ietf-tsvwg-sctp-auth].
3630 if (!sctp_addip_noauth
&& !asconf_ack
->auth
)
3631 return sctp_sf_discard_chunk(ep
, asoc
, type
, arg
, commands
);
3633 /* Make sure that the ADDIP chunk has a valid length. */
3634 if (!sctp_chunk_length_valid(asconf_ack
, sizeof(sctp_addip_chunk_t
)))
3635 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3638 addip_hdr
= (sctp_addiphdr_t
*)asconf_ack
->skb
->data
;
3639 rcvd_serial
= ntohl(addip_hdr
->serial
);
3641 /* Verify the ASCONF-ACK chunk before processing it. */
3642 if (!sctp_verify_asconf(asoc
,
3643 (sctp_paramhdr_t
*)addip_hdr
->params
,
3644 (void *)asconf_ack
->chunk_end
,
3646 return sctp_sf_violation_paramlen(ep
, asoc
, type
, arg
,
3647 (void *)err_param
, commands
);
3650 addip_hdr
= (sctp_addiphdr_t
*)last_asconf
->subh
.addip_hdr
;
3651 sent_serial
= ntohl(addip_hdr
->serial
);
3653 sent_serial
= asoc
->addip_serial
- 1;
3656 /* D0) If an endpoint receives an ASCONF-ACK that is greater than or
3657 * equal to the next serial number to be used but no ASCONF chunk is
3658 * outstanding the endpoint MUST ABORT the association. Note that a
3659 * sequence number is greater than if it is no more than 2^^31-1
3660 * larger than the current sequence number (using serial arithmetic).
3662 if (ADDIP_SERIAL_gte(rcvd_serial
, sent_serial
+ 1) &&
3663 !(asoc
->addip_last_asconf
)) {
3664 abort
= sctp_make_abort(asoc
, asconf_ack
,
3665 sizeof(sctp_errhdr_t
));
3667 sctp_init_cause(abort
, SCTP_ERROR_ASCONF_ACK
, 0);
3668 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
3671 /* We are going to ABORT, so we might as well stop
3672 * processing the rest of the chunks in the packet.
3674 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3675 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
3676 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
,SCTP_NULL());
3677 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
3678 SCTP_ERROR(ECONNABORTED
));
3679 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
3680 SCTP_PERR(SCTP_ERROR_ASCONF_ACK
));
3681 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
3682 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
3683 return SCTP_DISPOSITION_ABORT
;
3686 if ((rcvd_serial
== sent_serial
) && asoc
->addip_last_asconf
) {
3687 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3688 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
3690 if (!sctp_process_asconf_ack((struct sctp_association
*)asoc
,
3692 /* Successfully processed ASCONF_ACK. We can
3693 * release the next asconf if we have one.
3695 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_NEXT_ASCONF
,
3697 return SCTP_DISPOSITION_CONSUME
;
3700 abort
= sctp_make_abort(asoc
, asconf_ack
,
3701 sizeof(sctp_errhdr_t
));
3703 sctp_init_cause(abort
, SCTP_ERROR_RSRC_LOW
, 0);
3704 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
3707 /* We are going to ABORT, so we might as well stop
3708 * processing the rest of the chunks in the packet.
3710 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
,SCTP_NULL());
3711 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
3712 SCTP_ERROR(ECONNABORTED
));
3713 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
3714 SCTP_PERR(SCTP_ERROR_ASCONF_ACK
));
3715 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
3716 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
3717 return SCTP_DISPOSITION_ABORT
;
3720 return SCTP_DISPOSITION_DISCARD
;
3724 * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP
3726 * When a FORWARD TSN chunk arrives, the data receiver MUST first update
3727 * its cumulative TSN point to the value carried in the FORWARD TSN
3728 * chunk, and then MUST further advance its cumulative TSN point locally
3730 * After the above processing, the data receiver MUST stop reporting any
3731 * missing TSNs earlier than or equal to the new cumulative TSN point.
3733 * Verification Tag: 8.5 Verification Tag [Normal verification]
3735 * The return value is the disposition of the chunk.
3737 sctp_disposition_t
sctp_sf_eat_fwd_tsn(const struct sctp_endpoint
*ep
,
3738 const struct sctp_association
*asoc
,
3739 const sctp_subtype_t type
,
3741 sctp_cmd_seq_t
*commands
)
3743 struct sctp_chunk
*chunk
= arg
;
3744 struct sctp_fwdtsn_hdr
*fwdtsn_hdr
;
3745 struct sctp_fwdtsn_skip
*skip
;
3749 if (!sctp_vtag_verify(chunk
, asoc
)) {
3750 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3752 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3755 /* Make sure that the FORWARD_TSN chunk has valid length. */
3756 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_fwdtsn_chunk
)))
3757 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3760 fwdtsn_hdr
= (struct sctp_fwdtsn_hdr
*)chunk
->skb
->data
;
3761 chunk
->subh
.fwdtsn_hdr
= fwdtsn_hdr
;
3762 len
= ntohs(chunk
->chunk_hdr
->length
);
3763 len
-= sizeof(struct sctp_chunkhdr
);
3764 skb_pull(chunk
->skb
, len
);
3766 tsn
= ntohl(fwdtsn_hdr
->new_cum_tsn
);
3767 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __func__
, tsn
);
3769 /* The TSN is too high--silently discard the chunk and count on it
3770 * getting retransmitted later.
3772 if (sctp_tsnmap_check(&asoc
->peer
.tsn_map
, tsn
) < 0)
3773 goto discard_noforce
;
3775 /* Silently discard the chunk if stream-id is not valid */
3776 sctp_walk_fwdtsn(skip
, chunk
) {
3777 if (ntohs(skip
->stream
) >= asoc
->c
.sinit_max_instreams
)
3778 goto discard_noforce
;
3781 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_FWDTSN
, SCTP_U32(tsn
));
3782 if (len
> sizeof(struct sctp_fwdtsn_hdr
))
3783 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_FWDTSN
,
3786 /* Count this as receiving DATA. */
3787 if (asoc
->autoclose
) {
3788 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
3789 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
3792 /* FIXME: For now send a SACK, but DATA processing may
3795 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_NOFORCE());
3797 return SCTP_DISPOSITION_CONSUME
;
3800 return SCTP_DISPOSITION_DISCARD
;
3803 sctp_disposition_t
sctp_sf_eat_fwd_tsn_fast(
3804 const struct sctp_endpoint
*ep
,
3805 const struct sctp_association
*asoc
,
3806 const sctp_subtype_t type
,
3808 sctp_cmd_seq_t
*commands
)
3810 struct sctp_chunk
*chunk
= arg
;
3811 struct sctp_fwdtsn_hdr
*fwdtsn_hdr
;
3812 struct sctp_fwdtsn_skip
*skip
;
3816 if (!sctp_vtag_verify(chunk
, asoc
)) {
3817 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3819 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3822 /* Make sure that the FORWARD_TSN chunk has a valid length. */
3823 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_fwdtsn_chunk
)))
3824 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3827 fwdtsn_hdr
= (struct sctp_fwdtsn_hdr
*)chunk
->skb
->data
;
3828 chunk
->subh
.fwdtsn_hdr
= fwdtsn_hdr
;
3829 len
= ntohs(chunk
->chunk_hdr
->length
);
3830 len
-= sizeof(struct sctp_chunkhdr
);
3831 skb_pull(chunk
->skb
, len
);
3833 tsn
= ntohl(fwdtsn_hdr
->new_cum_tsn
);
3834 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __func__
, tsn
);
3836 /* The TSN is too high--silently discard the chunk and count on it
3837 * getting retransmitted later.
3839 if (sctp_tsnmap_check(&asoc
->peer
.tsn_map
, tsn
) < 0)
3842 /* Silently discard the chunk if stream-id is not valid */
3843 sctp_walk_fwdtsn(skip
, chunk
) {
3844 if (ntohs(skip
->stream
) >= asoc
->c
.sinit_max_instreams
)
3848 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_FWDTSN
, SCTP_U32(tsn
));
3849 if (len
> sizeof(struct sctp_fwdtsn_hdr
))
3850 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_FWDTSN
,
3853 /* Go a head and force a SACK, since we are shutting down. */
3855 /* Implementor's Guide.
3857 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3858 * respond to each received packet containing one or more DATA chunk(s)
3859 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3861 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SHUTDOWN
, SCTP_NULL());
3862 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_FORCE());
3863 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
3864 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
3866 return SCTP_DISPOSITION_CONSUME
;
3870 * SCTP-AUTH Section 6.3 Receiving authenticated chukns
3872 * The receiver MUST use the HMAC algorithm indicated in the HMAC
3873 * Identifier field. If this algorithm was not specified by the
3874 * receiver in the HMAC-ALGO parameter in the INIT or INIT-ACK chunk
3875 * during association setup, the AUTH chunk and all chunks after it MUST
3876 * be discarded and an ERROR chunk SHOULD be sent with the error cause
3877 * defined in Section 4.1.
3879 * If an endpoint with no shared key receives a Shared Key Identifier
3880 * other than 0, it MUST silently discard all authenticated chunks. If
3881 * the endpoint has at least one endpoint pair shared key for the peer,
3882 * it MUST use the key specified by the Shared Key Identifier if a
3883 * key has been configured for that Shared Key Identifier. If no
3884 * endpoint pair shared key has been configured for that Shared Key
3885 * Identifier, all authenticated chunks MUST be silently discarded.
3887 * Verification Tag: 8.5 Verification Tag [Normal verification]
3889 * The return value is the disposition of the chunk.
3891 static sctp_ierror_t
sctp_sf_authenticate(const struct sctp_endpoint
*ep
,
3892 const struct sctp_association
*asoc
,
3893 const sctp_subtype_t type
,
3894 struct sctp_chunk
*chunk
)
3896 struct sctp_authhdr
*auth_hdr
;
3897 struct sctp_hmac
*hmac
;
3898 unsigned int sig_len
;
3903 /* Pull in the auth header, so we can do some more verification */
3904 auth_hdr
= (struct sctp_authhdr
*)chunk
->skb
->data
;
3905 chunk
->subh
.auth_hdr
= auth_hdr
;
3906 skb_pull(chunk
->skb
, sizeof(struct sctp_authhdr
));
3908 /* Make sure that we suport the HMAC algorithm from the auth
3911 if (!sctp_auth_asoc_verify_hmac_id(asoc
, auth_hdr
->hmac_id
))
3912 return SCTP_IERROR_AUTH_BAD_HMAC
;
3914 /* Make sure that the provided shared key identifier has been
3917 key_id
= ntohs(auth_hdr
->shkey_id
);
3918 if (key_id
!= asoc
->active_key_id
&& !sctp_auth_get_shkey(asoc
, key_id
))
3919 return SCTP_IERROR_AUTH_BAD_KEYID
;
3922 /* Make sure that the length of the signature matches what
3925 sig_len
= ntohs(chunk
->chunk_hdr
->length
) - sizeof(sctp_auth_chunk_t
);
3926 hmac
= sctp_auth_get_hmac(ntohs(auth_hdr
->hmac_id
));
3927 if (sig_len
!= hmac
->hmac_len
)
3928 return SCTP_IERROR_PROTO_VIOLATION
;
3930 /* Now that we've done validation checks, we can compute and
3931 * verify the hmac. The steps involved are:
3932 * 1. Save the digest from the chunk.
3933 * 2. Zero out the digest in the chunk.
3934 * 3. Compute the new digest
3935 * 4. Compare saved and new digests.
3937 digest
= auth_hdr
->hmac
;
3938 skb_pull(chunk
->skb
, sig_len
);
3940 save_digest
= kmemdup(digest
, sig_len
, GFP_ATOMIC
);
3944 memset(digest
, 0, sig_len
);
3946 sctp_auth_calculate_hmac(asoc
, chunk
->skb
,
3947 (struct sctp_auth_chunk
*)chunk
->chunk_hdr
,
3950 /* Discard the packet if the digests do not match */
3951 if (memcmp(save_digest
, digest
, sig_len
)) {
3953 return SCTP_IERROR_BAD_SIG
;
3959 return SCTP_IERROR_NO_ERROR
;
3961 return SCTP_IERROR_NOMEM
;
3964 sctp_disposition_t
sctp_sf_eat_auth(const struct sctp_endpoint
*ep
,
3965 const struct sctp_association
*asoc
,
3966 const sctp_subtype_t type
,
3968 sctp_cmd_seq_t
*commands
)
3970 struct sctp_authhdr
*auth_hdr
;
3971 struct sctp_chunk
*chunk
= arg
;
3972 struct sctp_chunk
*err_chunk
;
3973 sctp_ierror_t error
;
3975 /* Make sure that the peer has AUTH capable */
3976 if (!asoc
->peer
.auth_capable
)
3977 return sctp_sf_unk_chunk(ep
, asoc
, type
, arg
, commands
);
3979 if (!sctp_vtag_verify(chunk
, asoc
)) {
3980 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3982 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3985 /* Make sure that the AUTH chunk has valid length. */
3986 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_auth_chunk
)))
3987 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3990 auth_hdr
= (struct sctp_authhdr
*)chunk
->skb
->data
;
3991 error
= sctp_sf_authenticate(ep
, asoc
, type
, chunk
);
3993 case SCTP_IERROR_AUTH_BAD_HMAC
:
3994 /* Generate the ERROR chunk and discard the rest
3997 err_chunk
= sctp_make_op_error(asoc
, chunk
,
3998 SCTP_ERROR_UNSUP_HMAC
,
4002 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
4003 SCTP_CHUNK(err_chunk
));
4006 case SCTP_IERROR_AUTH_BAD_KEYID
:
4007 case SCTP_IERROR_BAD_SIG
:
4008 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
4010 case SCTP_IERROR_PROTO_VIOLATION
:
4011 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
4014 case SCTP_IERROR_NOMEM
:
4015 return SCTP_DISPOSITION_NOMEM
;
4020 if (asoc
->active_key_id
!= ntohs(auth_hdr
->shkey_id
)) {
4021 struct sctp_ulpevent
*ev
;
4023 ev
= sctp_ulpevent_make_authkey(asoc
, ntohs(auth_hdr
->shkey_id
),
4024 SCTP_AUTH_NEWKEY
, GFP_ATOMIC
);
4029 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
4033 return SCTP_DISPOSITION_CONSUME
;
4037 * Process an unknown chunk.
4039 * Section: 3.2. Also, 2.1 in the implementor's guide.
4041 * Chunk Types are encoded such that the highest-order two bits specify
4042 * the action that must be taken if the processing endpoint does not
4043 * recognize the Chunk Type.
4045 * 00 - Stop processing this SCTP packet and discard it, do not process
4046 * any further chunks within it.
4048 * 01 - Stop processing this SCTP packet and discard it, do not process
4049 * any further chunks within it, and report the unrecognized
4050 * chunk in an 'Unrecognized Chunk Type'.
4052 * 10 - Skip this chunk and continue processing.
4054 * 11 - Skip this chunk and continue processing, but report in an ERROR
4055 * Chunk using the 'Unrecognized Chunk Type' cause of error.
4057 * The return value is the disposition of the chunk.
4059 sctp_disposition_t
sctp_sf_unk_chunk(const struct sctp_endpoint
*ep
,
4060 const struct sctp_association
*asoc
,
4061 const sctp_subtype_t type
,
4063 sctp_cmd_seq_t
*commands
)
4065 struct sctp_chunk
*unk_chunk
= arg
;
4066 struct sctp_chunk
*err_chunk
;
4067 sctp_chunkhdr_t
*hdr
;
4069 SCTP_DEBUG_PRINTK("Processing the unknown chunk id %d.\n", type
.chunk
);
4071 if (!sctp_vtag_verify(unk_chunk
, asoc
))
4072 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
4074 /* Make sure that the chunk has a valid length.
4075 * Since we don't know the chunk type, we use a general
4076 * chunkhdr structure to make a comparison.
4078 if (!sctp_chunk_length_valid(unk_chunk
, sizeof(sctp_chunkhdr_t
)))
4079 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
4082 switch (type
.chunk
& SCTP_CID_ACTION_MASK
) {
4083 case SCTP_CID_ACTION_DISCARD
:
4084 /* Discard the packet. */
4085 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
4087 case SCTP_CID_ACTION_DISCARD_ERR
:
4088 /* Generate an ERROR chunk as response. */
4089 hdr
= unk_chunk
->chunk_hdr
;
4090 err_chunk
= sctp_make_op_error(asoc
, unk_chunk
,
4091 SCTP_ERROR_UNKNOWN_CHUNK
, hdr
,
4092 WORD_ROUND(ntohs(hdr
->length
)),
4095 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
4096 SCTP_CHUNK(err_chunk
));
4099 /* Discard the packet. */
4100 sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
4101 return SCTP_DISPOSITION_CONSUME
;
4103 case SCTP_CID_ACTION_SKIP
:
4104 /* Skip the chunk. */
4105 return SCTP_DISPOSITION_DISCARD
;
4107 case SCTP_CID_ACTION_SKIP_ERR
:
4108 /* Generate an ERROR chunk as response. */
4109 hdr
= unk_chunk
->chunk_hdr
;
4110 err_chunk
= sctp_make_op_error(asoc
, unk_chunk
,
4111 SCTP_ERROR_UNKNOWN_CHUNK
, hdr
,
4112 WORD_ROUND(ntohs(hdr
->length
)),
4115 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
4116 SCTP_CHUNK(err_chunk
));
4118 /* Skip the chunk. */
4119 return SCTP_DISPOSITION_CONSUME
;
4125 return SCTP_DISPOSITION_DISCARD
;
4129 * Discard the chunk.
4131 * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2
4132 * [Too numerous to mention...]
4133 * Verification Tag: No verification needed.
4135 * (endpoint, asoc, chunk)
4138 * (asoc, reply_msg, msg_up, timers, counters)
4140 * The return value is the disposition of the chunk.
4142 sctp_disposition_t
sctp_sf_discard_chunk(const struct sctp_endpoint
*ep
,
4143 const struct sctp_association
*asoc
,
4144 const sctp_subtype_t type
,
4146 sctp_cmd_seq_t
*commands
)
4148 struct sctp_chunk
*chunk
= arg
;
4150 /* Make sure that the chunk has a valid length.
4151 * Since we don't know the chunk type, we use a general
4152 * chunkhdr structure to make a comparison.
4154 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
4155 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
4158 SCTP_DEBUG_PRINTK("Chunk %d is discarded\n", type
.chunk
);
4159 return SCTP_DISPOSITION_DISCARD
;
4163 * Discard the whole packet.
4167 * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST
4168 * silently discard the OOTB packet and take no further action.
4170 * Verification Tag: No verification necessary
4173 * (endpoint, asoc, chunk)
4176 * (asoc, reply_msg, msg_up, timers, counters)
4178 * The return value is the disposition of the chunk.
4180 sctp_disposition_t
sctp_sf_pdiscard(const struct sctp_endpoint
*ep
,
4181 const struct sctp_association
*asoc
,
4182 const sctp_subtype_t type
,
4184 sctp_cmd_seq_t
*commands
)
4186 SCTP_INC_STATS(SCTP_MIB_IN_PKT_DISCARDS
);
4187 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
, SCTP_NULL());
4189 return SCTP_DISPOSITION_CONSUME
;
4194 * The other end is violating protocol.
4196 * Section: Not specified
4197 * Verification Tag: Not specified
4199 * (endpoint, asoc, chunk)
4202 * (asoc, reply_msg, msg_up, timers, counters)
4204 * We simply tag the chunk as a violation. The state machine will log
4205 * the violation and continue.
4207 sctp_disposition_t
sctp_sf_violation(const struct sctp_endpoint
*ep
,
4208 const struct sctp_association
*asoc
,
4209 const sctp_subtype_t type
,
4211 sctp_cmd_seq_t
*commands
)
4213 struct sctp_chunk
*chunk
= arg
;
4215 /* Make sure that the chunk has a valid length. */
4216 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
4217 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
4220 return SCTP_DISPOSITION_VIOLATION
;
4224 * Common function to handle a protocol violation.
4226 static sctp_disposition_t
sctp_sf_abort_violation(
4227 const struct sctp_endpoint
*ep
,
4228 const struct sctp_association
*asoc
,
4230 sctp_cmd_seq_t
*commands
,
4231 const __u8
*payload
,
4232 const size_t paylen
)
4234 struct sctp_packet
*packet
= NULL
;
4235 struct sctp_chunk
*chunk
= arg
;
4236 struct sctp_chunk
*abort
= NULL
;
4238 /* SCTP-AUTH, Section 6.3:
4239 * It should be noted that if the receiver wants to tear
4240 * down an association in an authenticated way only, the
4241 * handling of malformed packets should not result in
4242 * tearing down the association.
4244 * This means that if we only want to abort associations
4245 * in an authenticated way (i.e AUTH+ABORT), then we
4246 * can't destroy this association just because the packet
4249 if (sctp_auth_recv_cid(SCTP_CID_ABORT
, asoc
))
4252 /* Make the abort chunk. */
4253 abort
= sctp_make_abort_violation(asoc
, chunk
, payload
, paylen
);
4258 /* Treat INIT-ACK as a special case during COOKIE-WAIT. */
4259 if (chunk
->chunk_hdr
->type
== SCTP_CID_INIT_ACK
&&
4260 !asoc
->peer
.i
.init_tag
) {
4261 sctp_initack_chunk_t
*initack
;
4263 initack
= (sctp_initack_chunk_t
*)chunk
->chunk_hdr
;
4264 if (!sctp_chunk_length_valid(chunk
,
4265 sizeof(sctp_initack_chunk_t
)))
4266 abort
->chunk_hdr
->flags
|= SCTP_CHUNK_FLAG_T
;
4268 unsigned int inittag
;
4270 inittag
= ntohl(initack
->init_hdr
.init_tag
);
4271 sctp_add_cmd_sf(commands
, SCTP_CMD_UPDATE_INITTAG
,
4276 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(abort
));
4277 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
4279 if (asoc
->state
<= SCTP_STATE_COOKIE_ECHOED
) {
4280 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4281 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
4282 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
4283 SCTP_ERROR(ECONNREFUSED
));
4284 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
4285 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION
));
4287 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
4288 SCTP_ERROR(ECONNABORTED
));
4289 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
4290 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION
));
4291 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
4294 packet
= sctp_ootb_pkt_new(asoc
, chunk
);
4299 if (sctp_test_T_bit(abort
))
4300 packet
->vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
4302 abort
->skb
->sk
= ep
->base
.sk
;
4304 sctp_packet_append_chunk(packet
, abort
);
4306 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
4307 SCTP_PACKET(packet
));
4309 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
4312 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
4315 sctp_sf_pdiscard(ep
, asoc
, SCTP_ST_CHUNK(0), arg
, commands
);
4316 return SCTP_DISPOSITION_ABORT
;
4319 sctp_chunk_free(abort
);
4321 return SCTP_DISPOSITION_NOMEM
;
4325 * Handle a protocol violation when the chunk length is invalid.
4326 * "Invalid" length is identified as smaller than the minimal length a
4327 * given chunk can be. For example, a SACK chunk has invalid length
4328 * if its length is set to be smaller than the size of sctp_sack_chunk_t.
4330 * We inform the other end by sending an ABORT with a Protocol Violation
4333 * Section: Not specified
4334 * Verification Tag: Nothing to do
4336 * (endpoint, asoc, chunk)
4339 * (reply_msg, msg_up, counters)
4341 * Generate an ABORT chunk and terminate the association.
4343 static sctp_disposition_t
sctp_sf_violation_chunklen(
4344 const struct sctp_endpoint
*ep
,
4345 const struct sctp_association
*asoc
,
4346 const sctp_subtype_t type
,
4348 sctp_cmd_seq_t
*commands
)
4350 static const char err_str
[]="The following chunk had invalid length:";
4352 return sctp_sf_abort_violation(ep
, asoc
, arg
, commands
, err_str
,
4357 * Handle a protocol violation when the parameter length is invalid.
4358 * If the length is smaller than the minimum length of a given parameter,
4359 * or accumulated length in multi parameters exceeds the end of the chunk,
4360 * the length is considered as invalid.
4362 static sctp_disposition_t
sctp_sf_violation_paramlen(
4363 const struct sctp_endpoint
*ep
,
4364 const struct sctp_association
*asoc
,
4365 const sctp_subtype_t type
,
4366 void *arg
, void *ext
,
4367 sctp_cmd_seq_t
*commands
)
4369 struct sctp_chunk
*chunk
= arg
;
4370 struct sctp_paramhdr
*param
= ext
;
4371 struct sctp_chunk
*abort
= NULL
;
4373 if (sctp_auth_recv_cid(SCTP_CID_ABORT
, asoc
))
4376 /* Make the abort chunk. */
4377 abort
= sctp_make_violation_paramlen(asoc
, chunk
, param
);
4381 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(abort
));
4382 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
4384 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
4385 SCTP_ERROR(ECONNABORTED
));
4386 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
4387 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION
));
4388 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
4389 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
4392 sctp_sf_pdiscard(ep
, asoc
, SCTP_ST_CHUNK(0), arg
, commands
);
4393 return SCTP_DISPOSITION_ABORT
;
4395 return SCTP_DISPOSITION_NOMEM
;
4398 /* Handle a protocol violation when the peer trying to advance the
4399 * cumulative tsn ack to a point beyond the max tsn currently sent.
4401 * We inform the other end by sending an ABORT with a Protocol Violation
4404 static sctp_disposition_t
sctp_sf_violation_ctsn(
4405 const struct sctp_endpoint
*ep
,
4406 const struct sctp_association
*asoc
,
4407 const sctp_subtype_t type
,
4409 sctp_cmd_seq_t
*commands
)
4411 static const char err_str
[]="The cumulative tsn ack beyond the max tsn currently sent:";
4413 return sctp_sf_abort_violation(ep
, asoc
, arg
, commands
, err_str
,
4417 /* Handle protocol violation of an invalid chunk bundling. For example,
4418 * when we have an association and we receive bundled INIT-ACK, or
4419 * SHUDOWN-COMPLETE, our peer is clearly violationg the "MUST NOT bundle"
4420 * statement from the specs. Additionally, there might be an attacker
4421 * on the path and we may not want to continue this communication.
4423 static sctp_disposition_t
sctp_sf_violation_chunk(
4424 const struct sctp_endpoint
*ep
,
4425 const struct sctp_association
*asoc
,
4426 const sctp_subtype_t type
,
4428 sctp_cmd_seq_t
*commands
)
4430 static const char err_str
[]="The following chunk violates protocol:";
4433 return sctp_sf_violation(ep
, asoc
, type
, arg
, commands
);
4435 return sctp_sf_abort_violation(ep
, asoc
, arg
, commands
, err_str
,
4438 /***************************************************************************
4439 * These are the state functions for handling primitive (Section 10) events.
4440 ***************************************************************************/
4442 * sctp_sf_do_prm_asoc
4444 * Section: 10.1 ULP-to-SCTP
4447 * Format: ASSOCIATE(local SCTP instance name, destination transport addr,
4448 * outbound stream count)
4449 * -> association id [,destination transport addr list] [,outbound stream
4452 * This primitive allows the upper layer to initiate an association to a
4453 * specific peer endpoint.
4455 * The peer endpoint shall be specified by one of the transport addresses
4456 * which defines the endpoint (see Section 1.4). If the local SCTP
4457 * instance has not been initialized, the ASSOCIATE is considered an
4459 * [This is not relevant for the kernel implementation since we do all
4460 * initialization at boot time. It we hadn't initialized we wouldn't
4461 * get anywhere near this code.]
4463 * An association id, which is a local handle to the SCTP association,
4464 * will be returned on successful establishment of the association. If
4465 * SCTP is not able to open an SCTP association with the peer endpoint,
4466 * an error is returned.
4467 * [In the kernel implementation, the struct sctp_association needs to
4468 * be created BEFORE causing this primitive to run.]
4470 * Other association parameters may be returned, including the
4471 * complete destination transport addresses of the peer as well as the
4472 * outbound stream count of the local endpoint. One of the transport
4473 * address from the returned destination addresses will be selected by
4474 * the local endpoint as default primary path for sending SCTP packets
4475 * to this peer. The returned "destination transport addr list" can
4476 * be used by the ULP to change the default primary path or to force
4477 * sending a packet to a specific transport address. [All of this
4478 * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING
4481 * Mandatory attributes:
4483 * o local SCTP instance name - obtained from the INITIALIZE operation.
4484 * [This is the argument asoc.]
4485 * o destination transport addr - specified as one of the transport
4486 * addresses of the peer endpoint with which the association is to be
4488 * [This is asoc->peer.active_path.]
4489 * o outbound stream count - the number of outbound streams the ULP
4490 * would like to open towards this peer endpoint.
4491 * [BUG: This is not currently implemented.]
4492 * Optional attributes:
4496 * The return value is a disposition.
4498 sctp_disposition_t
sctp_sf_do_prm_asoc(const struct sctp_endpoint
*ep
,
4499 const struct sctp_association
*asoc
,
4500 const sctp_subtype_t type
,
4502 sctp_cmd_seq_t
*commands
)
4504 struct sctp_chunk
*repl
;
4505 struct sctp_association
* my_asoc
;
4507 /* The comment below says that we enter COOKIE-WAIT AFTER
4508 * sending the INIT, but that doesn't actually work in our
4511 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
4512 SCTP_STATE(SCTP_STATE_COOKIE_WAIT
));
4514 /* RFC 2960 5.1 Normal Establishment of an Association
4516 * A) "A" first sends an INIT chunk to "Z". In the INIT, "A"
4517 * must provide its Verification Tag (Tag_A) in the Initiate
4518 * Tag field. Tag_A SHOULD be a random number in the range of
4519 * 1 to 4294967295 (see 5.3.1 for Tag value selection). ...
4522 repl
= sctp_make_init(asoc
, &asoc
->base
.bind_addr
, GFP_ATOMIC
, 0);
4526 /* Cast away the const modifier, as we want to just
4527 * rerun it through as a sideffect.
4529 my_asoc
= (struct sctp_association
*)asoc
;
4530 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(my_asoc
));
4532 /* Choose transport for INIT. */
4533 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_CHOOSE_TRANSPORT
,
4536 /* After sending the INIT, "A" starts the T1-init timer and
4537 * enters the COOKIE-WAIT state.
4539 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
4540 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
4541 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
4542 return SCTP_DISPOSITION_CONSUME
;
4545 return SCTP_DISPOSITION_NOMEM
;
4549 * Process the SEND primitive.
4551 * Section: 10.1 ULP-to-SCTP
4554 * Format: SEND(association id, buffer address, byte count [,context]
4555 * [,stream id] [,life time] [,destination transport address]
4556 * [,unorder flag] [,no-bundle flag] [,payload protocol-id] )
4559 * This is the main method to send user data via SCTP.
4561 * Mandatory attributes:
4563 * o association id - local handle to the SCTP association
4565 * o buffer address - the location where the user message to be
4566 * transmitted is stored;
4568 * o byte count - The size of the user data in number of bytes;
4570 * Optional attributes:
4572 * o context - an optional 32 bit integer that will be carried in the
4573 * sending failure notification to the ULP if the transportation of
4574 * this User Message fails.
4576 * o stream id - to indicate which stream to send the data on. If not
4577 * specified, stream 0 will be used.
4579 * o life time - specifies the life time of the user data. The user data
4580 * will not be sent by SCTP after the life time expires. This
4581 * parameter can be used to avoid efforts to transmit stale
4582 * user messages. SCTP notifies the ULP if the data cannot be
4583 * initiated to transport (i.e. sent to the destination via SCTP's
4584 * send primitive) within the life time variable. However, the
4585 * user data will be transmitted if SCTP has attempted to transmit a
4586 * chunk before the life time expired.
4588 * o destination transport address - specified as one of the destination
4589 * transport addresses of the peer endpoint to which this packet
4590 * should be sent. Whenever possible, SCTP should use this destination
4591 * transport address for sending the packets, instead of the current
4594 * o unorder flag - this flag, if present, indicates that the user
4595 * would like the data delivered in an unordered fashion to the peer
4596 * (i.e., the U flag is set to 1 on all DATA chunks carrying this
4599 * o no-bundle flag - instructs SCTP not to bundle this user data with
4600 * other outbound DATA chunks. SCTP MAY still bundle even when
4601 * this flag is present, when faced with network congestion.
4603 * o payload protocol-id - A 32 bit unsigned integer that is to be
4604 * passed to the peer indicating the type of payload protocol data
4605 * being transmitted. This value is passed as opaque data by SCTP.
4607 * The return value is the disposition.
4609 sctp_disposition_t
sctp_sf_do_prm_send(const struct sctp_endpoint
*ep
,
4610 const struct sctp_association
*asoc
,
4611 const sctp_subtype_t type
,
4613 sctp_cmd_seq_t
*commands
)
4615 struct sctp_datamsg
*msg
= arg
;
4617 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_MSG
, SCTP_DATAMSG(msg
));
4618 return SCTP_DISPOSITION_CONSUME
;
4622 * Process the SHUTDOWN primitive.
4627 * Format: SHUTDOWN(association id)
4630 * Gracefully closes an association. Any locally queued user data
4631 * will be delivered to the peer. The association will be terminated only
4632 * after the peer acknowledges all the SCTP packets sent. A success code
4633 * will be returned on successful termination of the association. If
4634 * attempting to terminate the association results in a failure, an error
4635 * code shall be returned.
4637 * Mandatory attributes:
4639 * o association id - local handle to the SCTP association
4641 * Optional attributes:
4645 * The return value is the disposition.
4647 sctp_disposition_t
sctp_sf_do_9_2_prm_shutdown(
4648 const struct sctp_endpoint
*ep
,
4649 const struct sctp_association
*asoc
,
4650 const sctp_subtype_t type
,
4652 sctp_cmd_seq_t
*commands
)
4656 /* From 9.2 Shutdown of an Association
4657 * Upon receipt of the SHUTDOWN primitive from its upper
4658 * layer, the endpoint enters SHUTDOWN-PENDING state and
4659 * remains there until all outstanding data has been
4660 * acknowledged by its peer. The endpoint accepts no new data
4661 * from its upper layer, but retransmits data to the far end
4662 * if necessary to fill gaps.
4664 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
4665 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING
));
4667 disposition
= SCTP_DISPOSITION_CONSUME
;
4668 if (sctp_outq_is_empty(&asoc
->outqueue
)) {
4669 disposition
= sctp_sf_do_9_2_start_shutdown(ep
, asoc
, type
,
4676 * Process the ABORT primitive.
4681 * Format: Abort(association id [, cause code])
4684 * Ungracefully closes an association. Any locally queued user data
4685 * will be discarded and an ABORT chunk is sent to the peer. A success code
4686 * will be returned on successful abortion of the association. If
4687 * attempting to abort the association results in a failure, an error
4688 * code shall be returned.
4690 * Mandatory attributes:
4692 * o association id - local handle to the SCTP association
4694 * Optional attributes:
4696 * o cause code - reason of the abort to be passed to the peer
4700 * The return value is the disposition.
4702 sctp_disposition_t
sctp_sf_do_9_1_prm_abort(
4703 const struct sctp_endpoint
*ep
,
4704 const struct sctp_association
*asoc
,
4705 const sctp_subtype_t type
,
4707 sctp_cmd_seq_t
*commands
)
4709 /* From 9.1 Abort of an Association
4710 * Upon receipt of the ABORT primitive from its upper
4711 * layer, the endpoint enters CLOSED state and
4712 * discard all outstanding data has been
4713 * acknowledged by its peer. The endpoint accepts no new data
4714 * from its upper layer, but retransmits data to the far end
4715 * if necessary to fill gaps.
4717 struct sctp_chunk
*abort
= arg
;
4718 sctp_disposition_t retval
;
4720 retval
= SCTP_DISPOSITION_CONSUME
;
4722 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(abort
));
4724 /* Even if we can't send the ABORT due to low memory delete the
4725 * TCB. This is a departure from our typical NOMEM handling.
4728 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
4729 SCTP_ERROR(ECONNABORTED
));
4730 /* Delete the established association. */
4731 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
4732 SCTP_PERR(SCTP_ERROR_USER_ABORT
));
4734 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
4735 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
4740 /* We tried an illegal operation on an association which is closed. */
4741 sctp_disposition_t
sctp_sf_error_closed(const struct sctp_endpoint
*ep
,
4742 const struct sctp_association
*asoc
,
4743 const sctp_subtype_t type
,
4745 sctp_cmd_seq_t
*commands
)
4747 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_ERROR
, SCTP_ERROR(-EINVAL
));
4748 return SCTP_DISPOSITION_CONSUME
;
4751 /* We tried an illegal operation on an association which is shutting
4754 sctp_disposition_t
sctp_sf_error_shutdown(const struct sctp_endpoint
*ep
,
4755 const struct sctp_association
*asoc
,
4756 const sctp_subtype_t type
,
4758 sctp_cmd_seq_t
*commands
)
4760 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_ERROR
,
4761 SCTP_ERROR(-ESHUTDOWN
));
4762 return SCTP_DISPOSITION_CONSUME
;
4766 * sctp_cookie_wait_prm_shutdown
4768 * Section: 4 Note: 2
4773 * The RFC does not explicitly address this issue, but is the route through the
4774 * state table when someone issues a shutdown while in COOKIE_WAIT state.
4779 sctp_disposition_t
sctp_sf_cookie_wait_prm_shutdown(
4780 const struct sctp_endpoint
*ep
,
4781 const struct sctp_association
*asoc
,
4782 const sctp_subtype_t type
,
4784 sctp_cmd_seq_t
*commands
)
4786 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4787 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
4789 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
4790 SCTP_STATE(SCTP_STATE_CLOSED
));
4792 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS
);
4794 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
4796 return SCTP_DISPOSITION_DELETE_TCB
;
4800 * sctp_cookie_echoed_prm_shutdown
4802 * Section: 4 Note: 2
4807 * The RFC does not explcitly address this issue, but is the route through the
4808 * state table when someone issues a shutdown while in COOKIE_ECHOED state.
4813 sctp_disposition_t
sctp_sf_cookie_echoed_prm_shutdown(
4814 const struct sctp_endpoint
*ep
,
4815 const struct sctp_association
*asoc
,
4816 const sctp_subtype_t type
,
4817 void *arg
, sctp_cmd_seq_t
*commands
)
4819 /* There is a single T1 timer, so we should be able to use
4820 * common function with the COOKIE-WAIT state.
4822 return sctp_sf_cookie_wait_prm_shutdown(ep
, asoc
, type
, arg
, commands
);
4826 * sctp_sf_cookie_wait_prm_abort
4828 * Section: 4 Note: 2
4833 * The RFC does not explicitly address this issue, but is the route through the
4834 * state table when someone issues an abort while in COOKIE_WAIT state.
4839 sctp_disposition_t
sctp_sf_cookie_wait_prm_abort(
4840 const struct sctp_endpoint
*ep
,
4841 const struct sctp_association
*asoc
,
4842 const sctp_subtype_t type
,
4844 sctp_cmd_seq_t
*commands
)
4846 struct sctp_chunk
*abort
= arg
;
4847 sctp_disposition_t retval
;
4849 /* Stop T1-init timer */
4850 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4851 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
4852 retval
= SCTP_DISPOSITION_CONSUME
;
4854 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(abort
));
4856 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
4857 SCTP_STATE(SCTP_STATE_CLOSED
));
4859 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
4861 /* Even if we can't send the ABORT due to low memory delete the
4862 * TCB. This is a departure from our typical NOMEM handling.
4865 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
4866 SCTP_ERROR(ECONNREFUSED
));
4867 /* Delete the established association. */
4868 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
4869 SCTP_PERR(SCTP_ERROR_USER_ABORT
));
4875 * sctp_sf_cookie_echoed_prm_abort
4877 * Section: 4 Note: 3
4882 * The RFC does not explcitly address this issue, but is the route through the
4883 * state table when someone issues an abort while in COOKIE_ECHOED state.
4888 sctp_disposition_t
sctp_sf_cookie_echoed_prm_abort(
4889 const struct sctp_endpoint
*ep
,
4890 const struct sctp_association
*asoc
,
4891 const sctp_subtype_t type
,
4893 sctp_cmd_seq_t
*commands
)
4895 /* There is a single T1 timer, so we should be able to use
4896 * common function with the COOKIE-WAIT state.
4898 return sctp_sf_cookie_wait_prm_abort(ep
, asoc
, type
, arg
, commands
);
4902 * sctp_sf_shutdown_pending_prm_abort
4907 * The RFC does not explicitly address this issue, but is the route through the
4908 * state table when someone issues an abort while in SHUTDOWN-PENDING state.
4913 sctp_disposition_t
sctp_sf_shutdown_pending_prm_abort(
4914 const struct sctp_endpoint
*ep
,
4915 const struct sctp_association
*asoc
,
4916 const sctp_subtype_t type
,
4918 sctp_cmd_seq_t
*commands
)
4920 /* Stop the T5-shutdown guard timer. */
4921 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4922 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
4924 return sctp_sf_do_9_1_prm_abort(ep
, asoc
, type
, arg
, commands
);
4928 * sctp_sf_shutdown_sent_prm_abort
4933 * The RFC does not explicitly address this issue, but is the route through the
4934 * state table when someone issues an abort while in SHUTDOWN-SENT state.
4939 sctp_disposition_t
sctp_sf_shutdown_sent_prm_abort(
4940 const struct sctp_endpoint
*ep
,
4941 const struct sctp_association
*asoc
,
4942 const sctp_subtype_t type
,
4944 sctp_cmd_seq_t
*commands
)
4946 /* Stop the T2-shutdown timer. */
4947 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4948 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
4950 /* Stop the T5-shutdown guard timer. */
4951 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4952 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
4954 return sctp_sf_do_9_1_prm_abort(ep
, asoc
, type
, arg
, commands
);
4958 * sctp_sf_cookie_echoed_prm_abort
4963 * The RFC does not explcitly address this issue, but is the route through the
4964 * state table when someone issues an abort while in COOKIE_ECHOED state.
4969 sctp_disposition_t
sctp_sf_shutdown_ack_sent_prm_abort(
4970 const struct sctp_endpoint
*ep
,
4971 const struct sctp_association
*asoc
,
4972 const sctp_subtype_t type
,
4974 sctp_cmd_seq_t
*commands
)
4976 /* The same T2 timer, so we should be able to use
4977 * common function with the SHUTDOWN-SENT state.
4979 return sctp_sf_shutdown_sent_prm_abort(ep
, asoc
, type
, arg
, commands
);
4983 * Process the REQUESTHEARTBEAT primitive
4986 * J) Request Heartbeat
4988 * Format: REQUESTHEARTBEAT(association id, destination transport address)
4992 * Instructs the local endpoint to perform a HeartBeat on the specified
4993 * destination transport address of the given association. The returned
4994 * result should indicate whether the transmission of the HEARTBEAT
4995 * chunk to the destination address is successful.
4997 * Mandatory attributes:
4999 * o association id - local handle to the SCTP association
5001 * o destination transport address - the transport address of the
5002 * association on which a heartbeat should be issued.
5004 sctp_disposition_t
sctp_sf_do_prm_requestheartbeat(
5005 const struct sctp_endpoint
*ep
,
5006 const struct sctp_association
*asoc
,
5007 const sctp_subtype_t type
,
5009 sctp_cmd_seq_t
*commands
)
5011 if (SCTP_DISPOSITION_NOMEM
== sctp_sf_heartbeat(ep
, asoc
, type
,
5012 (struct sctp_transport
*)arg
, commands
))
5013 return SCTP_DISPOSITION_NOMEM
;
5016 * RFC 2960 (bis), section 8.3
5018 * D) Request an on-demand HEARTBEAT on a specific destination
5019 * transport address of a given association.
5021 * The endpoint should increment the respective error counter of
5022 * the destination transport address each time a HEARTBEAT is sent
5023 * to that address and not acknowledged within one RTO.
5026 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSPORT_HB_SENT
,
5027 SCTP_TRANSPORT(arg
));
5028 return SCTP_DISPOSITION_CONSUME
;
5032 * ADDIP Section 4.1 ASCONF Chunk Procedures
5033 * When an endpoint has an ASCONF signaled change to be sent to the
5034 * remote endpoint it should do A1 to A9
5036 sctp_disposition_t
sctp_sf_do_prm_asconf(const struct sctp_endpoint
*ep
,
5037 const struct sctp_association
*asoc
,
5038 const sctp_subtype_t type
,
5040 sctp_cmd_seq_t
*commands
)
5042 struct sctp_chunk
*chunk
= arg
;
5044 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T4
, SCTP_CHUNK(chunk
));
5045 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
5046 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
5047 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(chunk
));
5048 return SCTP_DISPOSITION_CONSUME
;
5052 * Ignore the primitive event
5054 * The return value is the disposition of the primitive.
5056 sctp_disposition_t
sctp_sf_ignore_primitive(
5057 const struct sctp_endpoint
*ep
,
5058 const struct sctp_association
*asoc
,
5059 const sctp_subtype_t type
,
5061 sctp_cmd_seq_t
*commands
)
5063 SCTP_DEBUG_PRINTK("Primitive type %d is ignored.\n", type
.primitive
);
5064 return SCTP_DISPOSITION_DISCARD
;
5067 /***************************************************************************
5068 * These are the state functions for the OTHER events.
5069 ***************************************************************************/
5072 * Start the shutdown negotiation.
5075 * Once all its outstanding data has been acknowledged, the endpoint
5076 * shall send a SHUTDOWN chunk to its peer including in the Cumulative
5077 * TSN Ack field the last sequential TSN it has received from the peer.
5078 * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT
5079 * state. If the timer expires, the endpoint must re-send the SHUTDOWN
5080 * with the updated last sequential TSN received from its peer.
5082 * The return value is the disposition.
5084 sctp_disposition_t
sctp_sf_do_9_2_start_shutdown(
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 struct sctp_chunk
*reply
;
5093 /* Once all its outstanding data has been acknowledged, the
5094 * endpoint shall send a SHUTDOWN chunk to its peer including
5095 * in the Cumulative TSN Ack field the last sequential TSN it
5096 * has received from the peer.
5098 reply
= sctp_make_shutdown(asoc
, NULL
);
5102 /* Set the transport for the SHUTDOWN chunk and the timeout for the
5103 * T2-shutdown timer.
5105 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T2
, SCTP_CHUNK(reply
));
5107 /* It shall then start the T2-shutdown timer */
5108 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
5109 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
5111 /* RFC 4960 Section 9.2
5112 * The sender of the SHUTDOWN MAY also start an overall guard timer
5113 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5115 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
5116 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
5118 if (asoc
->autoclose
)
5119 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
5120 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
5122 /* and enter the SHUTDOWN-SENT state. */
5123 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
5124 SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT
));
5126 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5128 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
5131 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_STOP
, SCTP_NULL());
5133 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
5135 return SCTP_DISPOSITION_CONSUME
;
5138 return SCTP_DISPOSITION_NOMEM
;
5142 * Generate a SHUTDOWN ACK now that everything is SACK'd.
5146 * If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5147 * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own,
5148 * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the
5149 * endpoint must re-send the SHUTDOWN ACK.
5151 * The return value is the disposition.
5153 sctp_disposition_t
sctp_sf_do_9_2_shutdown_ack(
5154 const struct sctp_endpoint
*ep
,
5155 const struct sctp_association
*asoc
,
5156 const sctp_subtype_t type
,
5158 sctp_cmd_seq_t
*commands
)
5160 struct sctp_chunk
*chunk
= (struct sctp_chunk
*) arg
;
5161 struct sctp_chunk
*reply
;
5163 /* There are 2 ways of getting here:
5164 * 1) called in response to a SHUTDOWN chunk
5165 * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued.
5167 * For the case (2), the arg parameter is set to NULL. We need
5168 * to check that we have a chunk before accessing it's fields.
5171 if (!sctp_vtag_verify(chunk
, asoc
))
5172 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
5174 /* Make sure that the SHUTDOWN chunk has a valid length. */
5175 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_shutdown_chunk_t
)))
5176 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
5180 /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5181 * shall send a SHUTDOWN ACK ...
5183 reply
= sctp_make_shutdown_ack(asoc
, chunk
);
5187 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
5188 * the T2-shutdown timer.
5190 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T2
, SCTP_CHUNK(reply
));
5192 /* and start/restart a T2-shutdown timer of its own, */
5193 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
5194 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
5196 if (asoc
->autoclose
)
5197 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
5198 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
5200 /* Enter the SHUTDOWN-ACK-SENT state. */
5201 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
5202 SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT
));
5204 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5206 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
5209 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_STOP
, SCTP_NULL());
5211 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
5213 return SCTP_DISPOSITION_CONSUME
;
5216 return SCTP_DISPOSITION_NOMEM
;
5220 * Ignore the event defined as other
5222 * The return value is the disposition of the event.
5224 sctp_disposition_t
sctp_sf_ignore_other(const struct sctp_endpoint
*ep
,
5225 const struct sctp_association
*asoc
,
5226 const sctp_subtype_t type
,
5228 sctp_cmd_seq_t
*commands
)
5230 SCTP_DEBUG_PRINTK("The event other type %d is ignored\n", type
.other
);
5231 return SCTP_DISPOSITION_DISCARD
;
5234 /************************************************************
5235 * These are the state functions for handling timeout events.
5236 ************************************************************/
5241 * Section: 6.3.3 Handle T3-rtx Expiration
5243 * Whenever the retransmission timer T3-rtx expires for a destination
5244 * address, do the following:
5247 * The return value is the disposition of the chunk.
5249 sctp_disposition_t
sctp_sf_do_6_3_3_rtx(const struct sctp_endpoint
*ep
,
5250 const struct sctp_association
*asoc
,
5251 const sctp_subtype_t type
,
5253 sctp_cmd_seq_t
*commands
)
5255 struct sctp_transport
*transport
= arg
;
5257 SCTP_INC_STATS(SCTP_MIB_T3_RTX_EXPIREDS
);
5259 if (asoc
->overall_error_count
>= asoc
->max_retrans
) {
5260 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5261 SCTP_ERROR(ETIMEDOUT
));
5262 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5263 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
5264 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5265 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
5266 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
5267 return SCTP_DISPOSITION_DELETE_TCB
;
5270 /* E1) For the destination address for which the timer
5271 * expires, adjust its ssthresh with rules defined in Section
5272 * 7.2.3 and set the cwnd <- MTU.
5275 /* E2) For the destination address for which the timer
5276 * expires, set RTO <- RTO * 2 ("back off the timer"). The
5277 * maximum value discussed in rule C7 above (RTO.max) may be
5278 * used to provide an upper bound to this doubling operation.
5281 /* E3) Determine how many of the earliest (i.e., lowest TSN)
5282 * outstanding DATA chunks for the address for which the
5283 * T3-rtx has expired will fit into a single packet, subject
5284 * to the MTU constraint for the path corresponding to the
5285 * destination transport address to which the retransmission
5286 * is being sent (this may be different from the address for
5287 * which the timer expires [see Section 6.4]). Call this
5288 * value K. Bundle and retransmit those K DATA chunks in a
5289 * single packet to the destination endpoint.
5291 * Note: Any DATA chunks that were sent to the address for
5292 * which the T3-rtx timer expired but did not fit in one MTU
5293 * (rule E3 above), should be marked for retransmission and
5294 * sent as soon as cwnd allows (normally when a SACK arrives).
5297 /* Do some failure management (Section 8.2). */
5298 sctp_add_cmd_sf(commands
, SCTP_CMD_STRIKE
, SCTP_TRANSPORT(transport
));
5300 /* NB: Rules E4 and F1 are implicit in R1. */
5301 sctp_add_cmd_sf(commands
, SCTP_CMD_RETRAN
, SCTP_TRANSPORT(transport
));
5303 return SCTP_DISPOSITION_CONSUME
;
5307 * Generate delayed SACK on timeout
5309 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
5311 * The guidelines on delayed acknowledgement algorithm specified in
5312 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
5313 * acknowledgement SHOULD be generated for at least every second packet
5314 * (not every second DATA chunk) received, and SHOULD be generated
5315 * within 200 ms of the arrival of any unacknowledged DATA chunk. In
5316 * some situations it may be beneficial for an SCTP transmitter to be
5317 * more conservative than the algorithms detailed in this document
5318 * allow. However, an SCTP transmitter MUST NOT be more aggressive than
5319 * the following algorithms allow.
5321 sctp_disposition_t
sctp_sf_do_6_2_sack(const struct sctp_endpoint
*ep
,
5322 const struct sctp_association
*asoc
,
5323 const sctp_subtype_t type
,
5325 sctp_cmd_seq_t
*commands
)
5327 SCTP_INC_STATS(SCTP_MIB_DELAY_SACK_EXPIREDS
);
5328 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_FORCE());
5329 return SCTP_DISPOSITION_CONSUME
;
5333 * sctp_sf_t1_init_timer_expire
5335 * Section: 4 Note: 2
5340 * RFC 2960 Section 4 Notes
5341 * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT
5342 * and re-start the T1-init timer without changing state. This MUST
5343 * be repeated up to 'Max.Init.Retransmits' times. After that, the
5344 * endpoint MUST abort the initialization process and report the
5345 * error to SCTP user.
5351 sctp_disposition_t
sctp_sf_t1_init_timer_expire(const struct sctp_endpoint
*ep
,
5352 const struct sctp_association
*asoc
,
5353 const sctp_subtype_t type
,
5355 sctp_cmd_seq_t
*commands
)
5357 struct sctp_chunk
*repl
= NULL
;
5358 struct sctp_bind_addr
*bp
;
5359 int attempts
= asoc
->init_err_counter
+ 1;
5361 SCTP_DEBUG_PRINTK("Timer T1 expired (INIT).\n");
5362 SCTP_INC_STATS(SCTP_MIB_T1_INIT_EXPIREDS
);
5364 if (attempts
<= asoc
->max_init_attempts
) {
5365 bp
= (struct sctp_bind_addr
*) &asoc
->base
.bind_addr
;
5366 repl
= sctp_make_init(asoc
, bp
, GFP_ATOMIC
, 0);
5368 return SCTP_DISPOSITION_NOMEM
;
5370 /* Choose transport for INIT. */
5371 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_CHOOSE_TRANSPORT
,
5374 /* Issue a sideeffect to do the needed accounting. */
5375 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_RESTART
,
5376 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
5378 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
5380 SCTP_DEBUG_PRINTK("Giving up on INIT, attempts: %d"
5381 " max_init_attempts: %d\n",
5382 attempts
, asoc
->max_init_attempts
);
5383 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5384 SCTP_ERROR(ETIMEDOUT
));
5385 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
5386 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5387 return SCTP_DISPOSITION_DELETE_TCB
;
5390 return SCTP_DISPOSITION_CONSUME
;
5394 * sctp_sf_t1_cookie_timer_expire
5396 * Section: 4 Note: 2
5401 * RFC 2960 Section 4 Notes
5402 * 3) If the T1-cookie timer expires, the endpoint MUST retransmit
5403 * COOKIE ECHO and re-start the T1-cookie timer without changing
5404 * state. This MUST be repeated up to 'Max.Init.Retransmits' times.
5405 * After that, the endpoint MUST abort the initialization process and
5406 * report the error to SCTP user.
5412 sctp_disposition_t
sctp_sf_t1_cookie_timer_expire(const struct sctp_endpoint
*ep
,
5413 const struct sctp_association
*asoc
,
5414 const sctp_subtype_t type
,
5416 sctp_cmd_seq_t
*commands
)
5418 struct sctp_chunk
*repl
= NULL
;
5419 int attempts
= asoc
->init_err_counter
+ 1;
5421 SCTP_DEBUG_PRINTK("Timer T1 expired (COOKIE-ECHO).\n");
5422 SCTP_INC_STATS(SCTP_MIB_T1_COOKIE_EXPIREDS
);
5424 if (attempts
<= asoc
->max_init_attempts
) {
5425 repl
= sctp_make_cookie_echo(asoc
, NULL
);
5427 return SCTP_DISPOSITION_NOMEM
;
5429 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_CHOOSE_TRANSPORT
,
5431 /* Issue a sideeffect to do the needed accounting. */
5432 sctp_add_cmd_sf(commands
, SCTP_CMD_COOKIEECHO_RESTART
,
5433 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
5435 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
5437 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5438 SCTP_ERROR(ETIMEDOUT
));
5439 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
5440 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5441 return SCTP_DISPOSITION_DELETE_TCB
;
5444 return SCTP_DISPOSITION_CONSUME
;
5447 /* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN
5448 * with the updated last sequential TSN received from its peer.
5450 * An endpoint should limit the number of retransmissions of the
5451 * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'.
5452 * If this threshold is exceeded the endpoint should destroy the TCB and
5453 * MUST report the peer endpoint unreachable to the upper layer (and
5454 * thus the association enters the CLOSED state). The reception of any
5455 * packet from its peer (i.e. as the peer sends all of its queued DATA
5456 * chunks) should clear the endpoint's retransmission count and restart
5457 * the T2-Shutdown timer, giving its peer ample opportunity to transmit
5458 * all of its queued DATA chunks that have not yet been sent.
5460 sctp_disposition_t
sctp_sf_t2_timer_expire(const struct sctp_endpoint
*ep
,
5461 const struct sctp_association
*asoc
,
5462 const sctp_subtype_t type
,
5464 sctp_cmd_seq_t
*commands
)
5466 struct sctp_chunk
*reply
= NULL
;
5468 SCTP_DEBUG_PRINTK("Timer T2 expired.\n");
5469 SCTP_INC_STATS(SCTP_MIB_T2_SHUTDOWN_EXPIREDS
);
5471 ((struct sctp_association
*)asoc
)->shutdown_retries
++;
5473 if (asoc
->overall_error_count
>= asoc
->max_retrans
) {
5474 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5475 SCTP_ERROR(ETIMEDOUT
));
5476 /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5477 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
5478 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5479 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
5480 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
5481 return SCTP_DISPOSITION_DELETE_TCB
;
5484 switch (asoc
->state
) {
5485 case SCTP_STATE_SHUTDOWN_SENT
:
5486 reply
= sctp_make_shutdown(asoc
, NULL
);
5489 case SCTP_STATE_SHUTDOWN_ACK_SENT
:
5490 reply
= sctp_make_shutdown_ack(asoc
, NULL
);
5501 /* Do some failure management (Section 8.2).
5502 * If we remove the transport an SHUTDOWN was last sent to, don't
5503 * do failure management.
5505 if (asoc
->shutdown_last_sent_to
)
5506 sctp_add_cmd_sf(commands
, SCTP_CMD_STRIKE
,
5507 SCTP_TRANSPORT(asoc
->shutdown_last_sent_to
));
5509 /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for
5510 * the T2-shutdown timer.
5512 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T2
, SCTP_CHUNK(reply
));
5514 /* Restart the T2-shutdown timer. */
5515 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
5516 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
5517 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
5518 return SCTP_DISPOSITION_CONSUME
;
5521 return SCTP_DISPOSITION_NOMEM
;
5525 * ADDIP Section 4.1 ASCONF CHunk Procedures
5526 * If the T4 RTO timer expires the endpoint should do B1 to B5
5528 sctp_disposition_t
sctp_sf_t4_timer_expire(
5529 const struct sctp_endpoint
*ep
,
5530 const struct sctp_association
*asoc
,
5531 const sctp_subtype_t type
,
5533 sctp_cmd_seq_t
*commands
)
5535 struct sctp_chunk
*chunk
= asoc
->addip_last_asconf
;
5536 struct sctp_transport
*transport
= chunk
->transport
;
5538 SCTP_INC_STATS(SCTP_MIB_T4_RTO_EXPIREDS
);
5540 /* ADDIP 4.1 B1) Increment the error counters and perform path failure
5541 * detection on the appropriate destination address as defined in
5542 * RFC2960 [5] section 8.1 and 8.2.
5545 sctp_add_cmd_sf(commands
, SCTP_CMD_STRIKE
,
5546 SCTP_TRANSPORT(transport
));
5548 /* Reconfig T4 timer and transport. */
5549 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T4
, SCTP_CHUNK(chunk
));
5551 /* ADDIP 4.1 B2) Increment the association error counters and perform
5552 * endpoint failure detection on the association as defined in
5553 * RFC2960 [5] section 8.1 and 8.2.
5554 * association error counter is incremented in SCTP_CMD_STRIKE.
5556 if (asoc
->overall_error_count
>= asoc
->max_retrans
) {
5557 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
5558 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
5559 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5560 SCTP_ERROR(ETIMEDOUT
));
5561 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
5562 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5563 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
5564 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
5565 return SCTP_DISPOSITION_ABORT
;
5568 /* ADDIP 4.1 B3) Back-off the destination address RTO value to which
5569 * the ASCONF chunk was sent by doubling the RTO timer value.
5570 * This is done in SCTP_CMD_STRIKE.
5573 /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible
5574 * choose an alternate destination address (please refer to RFC2960
5575 * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this
5576 * chunk, it MUST be the same (including its serial number) as the last
5579 sctp_chunk_hold(asoc
->addip_last_asconf
);
5580 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
5581 SCTP_CHUNK(asoc
->addip_last_asconf
));
5583 /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different
5584 * destination is selected, then the RTO used will be that of the new
5585 * destination address.
5587 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
5588 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
5590 return SCTP_DISPOSITION_CONSUME
;
5593 /* sctpimpguide-05 Section 2.12.2
5594 * The sender of the SHUTDOWN MAY also start an overall guard timer
5595 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5596 * At the expiration of this timer the sender SHOULD abort the association
5597 * by sending an ABORT chunk.
5599 sctp_disposition_t
sctp_sf_t5_timer_expire(const struct sctp_endpoint
*ep
,
5600 const struct sctp_association
*asoc
,
5601 const sctp_subtype_t type
,
5603 sctp_cmd_seq_t
*commands
)
5605 struct sctp_chunk
*reply
= NULL
;
5607 SCTP_DEBUG_PRINTK("Timer T5 expired.\n");
5608 SCTP_INC_STATS(SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS
);
5610 reply
= sctp_make_abort(asoc
, NULL
, 0);
5614 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
5615 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5616 SCTP_ERROR(ETIMEDOUT
));
5617 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
5618 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5620 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
5621 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
5623 return SCTP_DISPOSITION_DELETE_TCB
;
5625 return SCTP_DISPOSITION_NOMEM
;
5628 /* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires,
5629 * the association is automatically closed by starting the shutdown process.
5630 * The work that needs to be done is same as when SHUTDOWN is initiated by
5631 * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown().
5633 sctp_disposition_t
sctp_sf_autoclose_timer_expire(
5634 const struct sctp_endpoint
*ep
,
5635 const struct sctp_association
*asoc
,
5636 const sctp_subtype_t type
,
5638 sctp_cmd_seq_t
*commands
)
5642 SCTP_INC_STATS(SCTP_MIB_AUTOCLOSE_EXPIREDS
);
5644 /* From 9.2 Shutdown of an Association
5645 * Upon receipt of the SHUTDOWN primitive from its upper
5646 * layer, the endpoint enters SHUTDOWN-PENDING state and
5647 * remains there until all outstanding data has been
5648 * acknowledged by its peer. The endpoint accepts no new data
5649 * from its upper layer, but retransmits data to the far end
5650 * if necessary to fill gaps.
5652 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
5653 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING
));
5655 disposition
= SCTP_DISPOSITION_CONSUME
;
5656 if (sctp_outq_is_empty(&asoc
->outqueue
)) {
5657 disposition
= sctp_sf_do_9_2_start_shutdown(ep
, asoc
, type
,
5663 /*****************************************************************************
5664 * These are sa state functions which could apply to all types of events.
5665 ****************************************************************************/
5668 * This table entry is not implemented.
5671 * (endpoint, asoc, chunk)
5673 * The return value is the disposition of the chunk.
5675 sctp_disposition_t
sctp_sf_not_impl(const struct sctp_endpoint
*ep
,
5676 const struct sctp_association
*asoc
,
5677 const sctp_subtype_t type
,
5679 sctp_cmd_seq_t
*commands
)
5681 return SCTP_DISPOSITION_NOT_IMPL
;
5685 * This table entry represents a bug.
5688 * (endpoint, asoc, chunk)
5690 * The return value is the disposition of the chunk.
5692 sctp_disposition_t
sctp_sf_bug(const struct sctp_endpoint
*ep
,
5693 const struct sctp_association
*asoc
,
5694 const sctp_subtype_t type
,
5696 sctp_cmd_seq_t
*commands
)
5698 return SCTP_DISPOSITION_BUG
;
5702 * This table entry represents the firing of a timer in the wrong state.
5703 * Since timer deletion cannot be guaranteed a timer 'may' end up firing
5704 * when the association is in the wrong state. This event should
5705 * be ignored, so as to prevent any rearming of the timer.
5708 * (endpoint, asoc, chunk)
5710 * The return value is the disposition of the chunk.
5712 sctp_disposition_t
sctp_sf_timer_ignore(const struct sctp_endpoint
*ep
,
5713 const struct sctp_association
*asoc
,
5714 const sctp_subtype_t type
,
5716 sctp_cmd_seq_t
*commands
)
5718 SCTP_DEBUG_PRINTK("Timer %d ignored.\n", type
.chunk
);
5719 return SCTP_DISPOSITION_CONSUME
;
5722 /********************************************************************
5723 * 2nd Level Abstractions
5724 ********************************************************************/
5726 /* Pull the SACK chunk based on the SACK header. */
5727 static struct sctp_sackhdr
*sctp_sm_pull_sack(struct sctp_chunk
*chunk
)
5729 struct sctp_sackhdr
*sack
;
5734 /* Protect ourselves from reading too far into
5735 * the skb from a bogus sender.
5737 sack
= (struct sctp_sackhdr
*) chunk
->skb
->data
;
5739 num_blocks
= ntohs(sack
->num_gap_ack_blocks
);
5740 num_dup_tsns
= ntohs(sack
->num_dup_tsns
);
5741 len
= sizeof(struct sctp_sackhdr
);
5742 len
+= (num_blocks
+ num_dup_tsns
) * sizeof(__u32
);
5743 if (len
> chunk
->skb
->len
)
5746 skb_pull(chunk
->skb
, len
);
5751 /* Create an ABORT packet to be sent as a response, with the specified
5754 static struct sctp_packet
*sctp_abort_pkt_new(const struct sctp_endpoint
*ep
,
5755 const struct sctp_association
*asoc
,
5756 struct sctp_chunk
*chunk
,
5757 const void *payload
,
5760 struct sctp_packet
*packet
;
5761 struct sctp_chunk
*abort
;
5763 packet
= sctp_ootb_pkt_new(asoc
, chunk
);
5767 * The T bit will be set if the asoc is NULL.
5769 abort
= sctp_make_abort(asoc
, chunk
, paylen
);
5771 sctp_ootb_pkt_free(packet
);
5775 /* Reflect vtag if T-Bit is set */
5776 if (sctp_test_T_bit(abort
))
5777 packet
->vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
5779 /* Add specified error causes, i.e., payload, to the
5782 sctp_addto_chunk(abort
, paylen
, payload
);
5784 /* Set the skb to the belonging sock for accounting. */
5785 abort
->skb
->sk
= ep
->base
.sk
;
5787 sctp_packet_append_chunk(packet
, abort
);
5794 /* Allocate a packet for responding in the OOTB conditions. */
5795 static struct sctp_packet
*sctp_ootb_pkt_new(const struct sctp_association
*asoc
,
5796 const struct sctp_chunk
*chunk
)
5798 struct sctp_packet
*packet
;
5799 struct sctp_transport
*transport
;
5804 /* Get the source and destination port from the inbound packet. */
5805 sport
= ntohs(chunk
->sctp_hdr
->dest
);
5806 dport
= ntohs(chunk
->sctp_hdr
->source
);
5808 /* The V-tag is going to be the same as the inbound packet if no
5809 * association exists, otherwise, use the peer's vtag.
5812 /* Special case the INIT-ACK as there is no peer's vtag
5815 switch(chunk
->chunk_hdr
->type
) {
5816 case SCTP_CID_INIT_ACK
:
5818 sctp_initack_chunk_t
*initack
;
5820 initack
= (sctp_initack_chunk_t
*)chunk
->chunk_hdr
;
5821 vtag
= ntohl(initack
->init_hdr
.init_tag
);
5825 vtag
= asoc
->peer
.i
.init_tag
;
5829 /* Special case the INIT and stale COOKIE_ECHO as there is no
5832 switch(chunk
->chunk_hdr
->type
) {
5835 sctp_init_chunk_t
*init
;
5837 init
= (sctp_init_chunk_t
*)chunk
->chunk_hdr
;
5838 vtag
= ntohl(init
->init_hdr
.init_tag
);
5842 vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
5847 /* Make a transport for the bucket, Eliza... */
5848 transport
= sctp_transport_new(sctp_source(chunk
), GFP_ATOMIC
);
5852 /* Cache a route for the transport with the chunk's destination as
5853 * the source address.
5855 sctp_transport_route(transport
, (union sctp_addr
*)&chunk
->dest
,
5856 sctp_sk(sctp_get_ctl_sock()));
5858 packet
= sctp_packet_init(&transport
->packet
, transport
, sport
, dport
);
5859 packet
= sctp_packet_config(packet
, vtag
, 0);
5867 /* Free the packet allocated earlier for responding in the OOTB condition. */
5868 void sctp_ootb_pkt_free(struct sctp_packet
*packet
)
5870 sctp_transport_free(packet
->transport
);
5873 /* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */
5874 static void sctp_send_stale_cookie_err(const struct sctp_endpoint
*ep
,
5875 const struct sctp_association
*asoc
,
5876 const struct sctp_chunk
*chunk
,
5877 sctp_cmd_seq_t
*commands
,
5878 struct sctp_chunk
*err_chunk
)
5880 struct sctp_packet
*packet
;
5883 packet
= sctp_ootb_pkt_new(asoc
, chunk
);
5885 struct sctp_signed_cookie
*cookie
;
5887 /* Override the OOTB vtag from the cookie. */
5888 cookie
= chunk
->subh
.cookie_hdr
;
5889 packet
->vtag
= cookie
->c
.peer_vtag
;
5891 /* Set the skb to the belonging sock for accounting. */
5892 err_chunk
->skb
->sk
= ep
->base
.sk
;
5893 sctp_packet_append_chunk(packet
, err_chunk
);
5894 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
5895 SCTP_PACKET(packet
));
5896 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
5898 sctp_chunk_free (err_chunk
);
5903 /* Process a data chunk */
5904 static int sctp_eat_data(const struct sctp_association
*asoc
,
5905 struct sctp_chunk
*chunk
,
5906 sctp_cmd_seq_t
*commands
)
5908 sctp_datahdr_t
*data_hdr
;
5909 struct sctp_chunk
*err
;
5911 sctp_verb_t deliver
;
5914 struct sctp_tsnmap
*map
= (struct sctp_tsnmap
*)&asoc
->peer
.tsn_map
;
5915 struct sock
*sk
= asoc
->base
.sk
;
5920 data_hdr
= chunk
->subh
.data_hdr
= (sctp_datahdr_t
*)chunk
->skb
->data
;
5921 skb_pull(chunk
->skb
, sizeof(sctp_datahdr_t
));
5923 tsn
= ntohl(data_hdr
->tsn
);
5924 SCTP_DEBUG_PRINTK("eat_data: TSN 0x%x.\n", tsn
);
5926 /* ASSERT: Now skb->data is really the user data. */
5928 /* Process ECN based congestion.
5930 * Since the chunk structure is reused for all chunks within
5931 * a packet, we use ecn_ce_done to track if we've already
5932 * done CE processing for this packet.
5934 * We need to do ECN processing even if we plan to discard the
5938 if (!chunk
->ecn_ce_done
) {
5940 chunk
->ecn_ce_done
= 1;
5942 af
= sctp_get_af_specific(
5943 ipver2af(ip_hdr(chunk
->skb
)->version
));
5945 if (af
&& af
->is_ce(chunk
->skb
) && asoc
->peer
.ecn_capable
) {
5946 /* Do real work as sideffect. */
5947 sctp_add_cmd_sf(commands
, SCTP_CMD_ECN_CE
,
5952 tmp
= sctp_tsnmap_check(&asoc
->peer
.tsn_map
, tsn
);
5954 /* The TSN is too high--silently discard the chunk and
5955 * count on it getting retransmitted later.
5957 return SCTP_IERROR_HIGH_TSN
;
5958 } else if (tmp
> 0) {
5959 /* This is a duplicate. Record it. */
5960 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_DUP
, SCTP_U32(tsn
));
5961 return SCTP_IERROR_DUP_TSN
;
5964 /* This is a new TSN. */
5966 /* Discard if there is no room in the receive window.
5967 * Actually, allow a little bit of overflow (up to a MTU).
5969 datalen
= ntohs(chunk
->chunk_hdr
->length
);
5970 datalen
-= sizeof(sctp_data_chunk_t
);
5972 deliver
= SCTP_CMD_CHUNK_ULP
;
5974 /* Think about partial delivery. */
5975 if ((datalen
>= asoc
->rwnd
) && (!asoc
->ulpq
.pd_mode
)) {
5977 /* Even if we don't accept this chunk there is
5980 sctp_add_cmd_sf(commands
, SCTP_CMD_PART_DELIVER
, SCTP_NULL());
5983 /* Spill over rwnd a little bit. Note: While allowed, this spill over
5984 * seems a bit troublesome in that frag_point varies based on
5985 * PMTU. In cases, such as loopback, this might be a rather
5988 if ((!chunk
->data_accepted
) && (!asoc
->rwnd
|| asoc
->rwnd_over
||
5989 (datalen
> asoc
->rwnd
+ asoc
->frag_point
))) {
5991 /* If this is the next TSN, consider reneging to make
5992 * room. Note: Playing nice with a confused sender. A
5993 * malicious sender can still eat up all our buffer
5994 * space and in the future we may want to detect and
5995 * do more drastic reneging.
5997 if (sctp_tsnmap_has_gap(map
) &&
5998 (sctp_tsnmap_get_ctsn(map
) + 1) == tsn
) {
5999 SCTP_DEBUG_PRINTK("Reneging for tsn:%u\n", tsn
);
6000 deliver
= SCTP_CMD_RENEGE
;
6002 SCTP_DEBUG_PRINTK("Discard tsn: %u len: %Zd, "
6003 "rwnd: %d\n", tsn
, datalen
,
6005 return SCTP_IERROR_IGNORE_TSN
;
6010 * Also try to renege to limit our memory usage in the event that
6011 * we are under memory pressure
6012 * If we can't renege, don't worry about it, the sk_rmem_schedule
6013 * in sctp_ulpevent_make_rcvmsg will drop the frame if we grow our
6014 * memory usage too much
6016 if (*sk
->sk_prot_creator
->memory_pressure
) {
6017 if (sctp_tsnmap_has_gap(map
) &&
6018 (sctp_tsnmap_get_ctsn(map
) + 1) == tsn
) {
6019 SCTP_DEBUG_PRINTK("Under Pressure! Reneging for tsn:%u\n", tsn
);
6020 deliver
= SCTP_CMD_RENEGE
;
6025 * Section 3.3.10.9 No User Data (9)
6029 * No User Data: This error cause is returned to the originator of a
6030 * DATA chunk if a received DATA chunk has no user data.
6032 if (unlikely(0 == datalen
)) {
6033 err
= sctp_make_abort_no_data(asoc
, chunk
, tsn
);
6035 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
6038 /* We are going to ABORT, so we might as well stop
6039 * processing the rest of the chunks in the packet.
6041 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
,SCTP_NULL());
6042 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
6043 SCTP_ERROR(ECONNABORTED
));
6044 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
6045 SCTP_PERR(SCTP_ERROR_NO_DATA
));
6046 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
6047 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
6048 return SCTP_IERROR_NO_DATA
;
6051 chunk
->data_accepted
= 1;
6053 /* Note: Some chunks may get overcounted (if we drop) or overcounted
6054 * if we renege and the chunk arrives again.
6056 if (chunk
->chunk_hdr
->flags
& SCTP_DATA_UNORDERED
)
6057 SCTP_INC_STATS(SCTP_MIB_INUNORDERCHUNKS
);
6059 SCTP_INC_STATS(SCTP_MIB_INORDERCHUNKS
);
6063 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
6065 * If an endpoint receive a DATA chunk with an invalid stream
6066 * identifier, it shall acknowledge the reception of the DATA chunk
6067 * following the normal procedure, immediately send an ERROR chunk
6068 * with cause set to "Invalid Stream Identifier" (See Section 3.3.10)
6069 * and discard the DATA chunk.
6071 sid
= ntohs(data_hdr
->stream
);
6072 if (sid
>= asoc
->c
.sinit_max_instreams
) {
6073 /* Mark tsn as received even though we drop it */
6074 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_TSN
, SCTP_U32(tsn
));
6076 err
= sctp_make_op_error(asoc
, chunk
, SCTP_ERROR_INV_STRM
,
6078 sizeof(data_hdr
->stream
),
6081 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
6083 return SCTP_IERROR_BAD_STREAM
;
6086 /* Check to see if the SSN is possible for this TSN.
6087 * The biggest gap we can record is 4K wide. Since SSNs wrap
6088 * at an unsigned short, there is no way that an SSN can
6089 * wrap and for a valid TSN. We can simply check if the current
6090 * SSN is smaller then the next expected one. If it is, it wrapped
6093 ssn
= ntohs(data_hdr
->ssn
);
6094 if (ordered
&& SSN_lt(ssn
, sctp_ssn_peek(&asoc
->ssnmap
->in
, sid
))) {
6095 return SCTP_IERROR_PROTO_VIOLATION
;
6098 /* Send the data up to the user. Note: Schedule the
6099 * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK
6100 * chunk needs the updated rwnd.
6102 sctp_add_cmd_sf(commands
, deliver
, SCTP_CHUNK(chunk
));
6104 return SCTP_IERROR_NO_ERROR
;