1 /* SCTP kernel implementation
2 * (C) Copyright IBM Corp. 2001, 2004
3 * Copyright (c) 1999-2000 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 * Copyright (c) 2001-2002 Intel Corp.
6 * Copyright (c) 2002 Nokia Corp.
8 * This is part of the SCTP Linux Kernel Implementation.
10 * These are the state functions for the state machine.
12 * This SCTP implementation is free software;
13 * you can redistribute it and/or modify it under the terms of
14 * the GNU General Public License as published by
15 * the Free Software Foundation; either version 2, or (at your option)
18 * This SCTP implementation is distributed in the hope that it
19 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
20 * ************************
21 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
22 * See the GNU General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with GNU CC; see the file COPYING. If not, write to
26 * the Free Software Foundation, 59 Temple Place - Suite 330,
27 * Boston, MA 02111-1307, USA.
29 * Please send any bug reports or fixes you make to the
31 * lksctp developers <lksctp-developers@lists.sourceforge.net>
33 * Or submit a bug report through the following website:
34 * http://www.sf.net/projects/lksctp
36 * Written or modified by:
37 * La Monte H.P. Yarroll <piggy@acm.org>
38 * Karl Knutson <karl@athena.chicago.il.us>
39 * Mathew Kotowsky <kotowsky@sctp.org>
40 * Sridhar Samudrala <samudrala@us.ibm.com>
41 * Jon Grimm <jgrimm@us.ibm.com>
42 * Hui Huang <hui.huang@nokia.com>
43 * Dajiang Zhang <dajiang.zhang@nokia.com>
44 * Daisy Chang <daisyc@us.ibm.com>
45 * Ardelle Fan <ardelle.fan@intel.com>
46 * Ryan Layer <rmlayer@us.ibm.com>
47 * Kevin Gao <kevin.gao@intel.com>
49 * Any bugs reported given to us we will try to fix... any fixes shared will
50 * be incorporated into the next SCTP release.
53 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
55 #include <linux/types.h>
56 #include <linux/kernel.h>
58 #include <linux/ipv6.h>
59 #include <linux/net.h>
60 #include <linux/inet.h>
61 #include <linux/slab.h>
63 #include <net/inet_ecn.h>
64 #include <linux/skbuff.h>
65 #include <net/sctp/sctp.h>
66 #include <net/sctp/sm.h>
67 #include <net/sctp/structs.h>
69 static struct sctp_packet
*sctp_abort_pkt_new(const struct sctp_endpoint
*ep
,
70 const struct sctp_association
*asoc
,
71 struct sctp_chunk
*chunk
,
74 static int sctp_eat_data(const struct sctp_association
*asoc
,
75 struct sctp_chunk
*chunk
,
76 sctp_cmd_seq_t
*commands
);
77 static struct sctp_packet
*sctp_ootb_pkt_new(const struct sctp_association
*asoc
,
78 const struct sctp_chunk
*chunk
);
79 static void sctp_send_stale_cookie_err(const struct sctp_endpoint
*ep
,
80 const struct sctp_association
*asoc
,
81 const struct sctp_chunk
*chunk
,
82 sctp_cmd_seq_t
*commands
,
83 struct sctp_chunk
*err_chunk
);
84 static sctp_disposition_t
sctp_sf_do_5_2_6_stale(const struct sctp_endpoint
*ep
,
85 const struct sctp_association
*asoc
,
86 const sctp_subtype_t type
,
88 sctp_cmd_seq_t
*commands
);
89 static sctp_disposition_t
sctp_sf_shut_8_4_5(const struct sctp_endpoint
*ep
,
90 const struct sctp_association
*asoc
,
91 const sctp_subtype_t type
,
93 sctp_cmd_seq_t
*commands
);
94 static sctp_disposition_t
sctp_sf_tabort_8_4_8(const struct sctp_endpoint
*ep
,
95 const struct sctp_association
*asoc
,
96 const sctp_subtype_t type
,
98 sctp_cmd_seq_t
*commands
);
99 static struct sctp_sackhdr
*sctp_sm_pull_sack(struct sctp_chunk
*chunk
);
101 static sctp_disposition_t
sctp_stop_t1_and_abort(sctp_cmd_seq_t
*commands
,
102 __be16 error
, int sk_err
,
103 const struct sctp_association
*asoc
,
104 struct sctp_transport
*transport
);
106 static sctp_disposition_t
sctp_sf_abort_violation(
107 const struct sctp_endpoint
*ep
,
108 const struct sctp_association
*asoc
,
110 sctp_cmd_seq_t
*commands
,
112 const size_t paylen
);
114 static sctp_disposition_t
sctp_sf_violation_chunklen(
115 const struct sctp_endpoint
*ep
,
116 const struct sctp_association
*asoc
,
117 const sctp_subtype_t type
,
119 sctp_cmd_seq_t
*commands
);
121 static sctp_disposition_t
sctp_sf_violation_paramlen(
122 const struct sctp_endpoint
*ep
,
123 const struct sctp_association
*asoc
,
124 const sctp_subtype_t type
,
125 void *arg
, void *ext
,
126 sctp_cmd_seq_t
*commands
);
128 static sctp_disposition_t
sctp_sf_violation_ctsn(
129 const struct sctp_endpoint
*ep
,
130 const struct sctp_association
*asoc
,
131 const sctp_subtype_t type
,
133 sctp_cmd_seq_t
*commands
);
135 static sctp_disposition_t
sctp_sf_violation_chunk(
136 const struct sctp_endpoint
*ep
,
137 const struct sctp_association
*asoc
,
138 const sctp_subtype_t type
,
140 sctp_cmd_seq_t
*commands
);
142 static sctp_ierror_t
sctp_sf_authenticate(const struct sctp_endpoint
*ep
,
143 const struct sctp_association
*asoc
,
144 const sctp_subtype_t type
,
145 struct sctp_chunk
*chunk
);
147 static sctp_disposition_t
__sctp_sf_do_9_1_abort(const struct sctp_endpoint
*ep
,
148 const struct sctp_association
*asoc
,
149 const sctp_subtype_t type
,
151 sctp_cmd_seq_t
*commands
);
153 /* Small helper function that checks if the chunk length
154 * is of the appropriate length. The 'required_length' argument
155 * is set to be the size of a specific chunk we are testing.
156 * Return Values: 1 = Valid length
161 sctp_chunk_length_valid(struct sctp_chunk
*chunk
,
162 __u16 required_length
)
164 __u16 chunk_length
= ntohs(chunk
->chunk_hdr
->length
);
166 if (unlikely(chunk_length
< required_length
))
172 /**********************************************************
173 * These are the state functions for handling chunk events.
174 **********************************************************/
177 * Process the final SHUTDOWN COMPLETE.
179 * Section: 4 (C) (diagram), 9.2
180 * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify
181 * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be
182 * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint
183 * should stop the T2-shutdown timer and remove all knowledge of the
184 * association (and thus the association enters the CLOSED state).
186 * Verification Tag: 8.5.1(C), sctpimpguide 2.41.
187 * C) Rules for packet carrying SHUTDOWN COMPLETE:
189 * - The receiver of a SHUTDOWN COMPLETE shall accept the packet
190 * if the Verification Tag field of the packet matches its own tag and
191 * the T bit is not set
193 * it is set to its peer's tag and the T bit is set in the Chunk
195 * Otherwise, the receiver MUST silently discard the packet
196 * and take no further action. An endpoint MUST ignore the
197 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
200 * (endpoint, asoc, chunk)
203 * (asoc, reply_msg, msg_up, timers, counters)
205 * The return value is the disposition of the chunk.
207 sctp_disposition_t
sctp_sf_do_4_C(const struct sctp_endpoint
*ep
,
208 const struct sctp_association
*asoc
,
209 const sctp_subtype_t type
,
211 sctp_cmd_seq_t
*commands
)
213 struct sctp_chunk
*chunk
= arg
;
214 struct sctp_ulpevent
*ev
;
216 if (!sctp_vtag_verify_either(chunk
, asoc
))
217 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
219 /* RFC 2960 6.10 Bundling
221 * An endpoint MUST NOT bundle INIT, INIT ACK or
222 * SHUTDOWN COMPLETE with any other chunks.
224 if (!chunk
->singleton
)
225 return sctp_sf_violation_chunk(ep
, asoc
, type
, arg
, commands
);
227 /* Make sure that the SHUTDOWN_COMPLETE chunk has a valid length. */
228 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
229 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
232 /* RFC 2960 10.2 SCTP-to-ULP
234 * H) SHUTDOWN COMPLETE notification
236 * When SCTP completes the shutdown procedures (section 9.2) this
237 * notification is passed to the upper layer.
239 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_SHUTDOWN_COMP
,
240 0, 0, 0, NULL
, GFP_ATOMIC
);
242 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
245 /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint
246 * will verify that it is in SHUTDOWN-ACK-SENT state, if it is
247 * not the chunk should be discarded. If the endpoint is in
248 * the SHUTDOWN-ACK-SENT state the endpoint should stop the
249 * T2-shutdown timer and remove all knowledge of the
250 * association (and thus the association enters the CLOSED
253 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
254 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
256 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
257 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
259 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
260 SCTP_STATE(SCTP_STATE_CLOSED
));
262 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS
);
263 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
265 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
267 return SCTP_DISPOSITION_DELETE_TCB
;
271 * Respond to a normal INIT chunk.
272 * We are the side that is being asked for an association.
274 * Section: 5.1 Normal Establishment of an Association, B
275 * B) "Z" shall respond immediately with an INIT ACK chunk. The
276 * destination IP address of the INIT ACK MUST be set to the source
277 * IP address of the INIT to which this INIT ACK is responding. In
278 * the response, besides filling in other parameters, "Z" must set the
279 * Verification Tag field to Tag_A, and also provide its own
280 * Verification Tag (Tag_Z) in the Initiate Tag field.
282 * Verification Tag: Must be 0.
285 * (endpoint, asoc, chunk)
288 * (asoc, reply_msg, msg_up, timers, counters)
290 * The return value is the disposition of the chunk.
292 sctp_disposition_t
sctp_sf_do_5_1B_init(const struct sctp_endpoint
*ep
,
293 const struct sctp_association
*asoc
,
294 const sctp_subtype_t type
,
296 sctp_cmd_seq_t
*commands
)
298 struct sctp_chunk
*chunk
= arg
;
299 struct sctp_chunk
*repl
;
300 struct sctp_association
*new_asoc
;
301 struct sctp_chunk
*err_chunk
;
302 struct sctp_packet
*packet
;
303 sctp_unrecognized_param_t
*unk_param
;
307 * An endpoint MUST NOT bundle INIT, INIT ACK or
308 * SHUTDOWN COMPLETE with any other chunks.
311 * Furthermore, we require that the receiver of an INIT chunk MUST
312 * enforce these rules by silently discarding an arriving packet
313 * with an INIT chunk that is bundled with other chunks.
315 if (!chunk
->singleton
)
316 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
318 /* If the packet is an OOTB packet which is temporarily on the
319 * control endpoint, respond with an ABORT.
321 if (ep
== sctp_sk((sctp_get_ctl_sock()))->ep
) {
322 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES
);
323 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
, commands
);
326 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
329 if (chunk
->sctp_hdr
->vtag
!= 0)
330 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
, commands
);
332 /* Make sure that the INIT chunk has a valid length.
333 * Normally, this would cause an ABORT with a Protocol Violation
334 * error, but since we don't have an association, we'll
335 * just discard the packet.
337 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_init_chunk_t
)))
338 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
340 /* If the INIT is coming toward a closing socket, we'll send back
341 * and ABORT. Essentially, this catches the race of INIT being
342 * backloged to the socket at the same time as the user isses close().
343 * Since the socket and all its associations are going away, we
344 * can treat this OOTB
346 if (sctp_sstate(ep
->base
.sk
, CLOSING
))
347 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
, commands
);
349 /* Verify the INIT chunk before processing it. */
351 if (!sctp_verify_init(asoc
, chunk
->chunk_hdr
->type
,
352 (sctp_init_chunk_t
*)chunk
->chunk_hdr
, chunk
,
354 /* This chunk contains fatal error. It is to be discarded.
355 * Send an ABORT, with causes if there is any.
358 packet
= sctp_abort_pkt_new(ep
, asoc
, arg
,
359 (__u8
*)(err_chunk
->chunk_hdr
) +
360 sizeof(sctp_chunkhdr_t
),
361 ntohs(err_chunk
->chunk_hdr
->length
) -
362 sizeof(sctp_chunkhdr_t
));
364 sctp_chunk_free(err_chunk
);
367 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
368 SCTP_PACKET(packet
));
369 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
370 return SCTP_DISPOSITION_CONSUME
;
372 return SCTP_DISPOSITION_NOMEM
;
375 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
,
380 /* Grab the INIT header. */
381 chunk
->subh
.init_hdr
= (sctp_inithdr_t
*)chunk
->skb
->data
;
383 /* Tag the variable length parameters. */
384 chunk
->param_hdr
.v
= skb_pull(chunk
->skb
, sizeof(sctp_inithdr_t
));
386 new_asoc
= sctp_make_temp_asoc(ep
, chunk
, GFP_ATOMIC
);
390 if (sctp_assoc_set_bind_addr_from_ep(new_asoc
,
391 sctp_scope(sctp_source(chunk
)),
395 /* The call, sctp_process_init(), can fail on memory allocation. */
396 if (!sctp_process_init(new_asoc
, chunk
, sctp_source(chunk
),
397 (sctp_init_chunk_t
*)chunk
->chunk_hdr
,
401 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
403 /* If there are errors need to be reported for unknown parameters,
404 * make sure to reserve enough room in the INIT ACK for them.
408 len
= ntohs(err_chunk
->chunk_hdr
->length
) -
409 sizeof(sctp_chunkhdr_t
);
411 repl
= sctp_make_init_ack(new_asoc
, chunk
, GFP_ATOMIC
, len
);
415 /* If there are errors need to be reported for unknown parameters,
416 * include them in the outgoing INIT ACK as "Unrecognized parameter"
420 /* Get the "Unrecognized parameter" parameter(s) out of the
421 * ERROR chunk generated by sctp_verify_init(). Since the
422 * error cause code for "unknown parameter" and the
423 * "Unrecognized parameter" type is the same, we can
424 * construct the parameters in INIT ACK by copying the
427 unk_param
= (sctp_unrecognized_param_t
*)
428 ((__u8
*)(err_chunk
->chunk_hdr
) +
429 sizeof(sctp_chunkhdr_t
));
430 /* Replace the cause code with the "Unrecognized parameter"
433 sctp_addto_chunk(repl
, len
, unk_param
);
434 sctp_chunk_free(err_chunk
);
437 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(new_asoc
));
439 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
442 * Note: After sending out INIT ACK with the State Cookie parameter,
443 * "Z" MUST NOT allocate any resources, nor keep any states for the
444 * new association. Otherwise, "Z" will be vulnerable to resource
447 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
449 return SCTP_DISPOSITION_DELETE_TCB
;
452 sctp_association_free(new_asoc
);
455 sctp_chunk_free(err_chunk
);
456 return SCTP_DISPOSITION_NOMEM
;
460 * Respond to a normal INIT ACK chunk.
461 * We are the side that is initiating the association.
463 * Section: 5.1 Normal Establishment of an Association, C
464 * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init
465 * timer and leave COOKIE-WAIT state. "A" shall then send the State
466 * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start
467 * the T1-cookie timer, and enter the COOKIE-ECHOED state.
469 * Note: The COOKIE ECHO chunk can be bundled with any pending outbound
470 * DATA chunks, but it MUST be the first chunk in the packet and
471 * until the COOKIE ACK is returned the sender MUST NOT send any
472 * other packets to the peer.
474 * Verification Tag: 3.3.3
475 * If the value of the Initiate Tag in a received INIT ACK chunk is
476 * found to be 0, the receiver MUST treat it as an error and close the
477 * association by transmitting an ABORT.
480 * (endpoint, asoc, chunk)
483 * (asoc, reply_msg, msg_up, timers, counters)
485 * The return value is the disposition of the chunk.
487 sctp_disposition_t
sctp_sf_do_5_1C_ack(const struct sctp_endpoint
*ep
,
488 const struct sctp_association
*asoc
,
489 const sctp_subtype_t type
,
491 sctp_cmd_seq_t
*commands
)
493 struct sctp_chunk
*chunk
= arg
;
494 sctp_init_chunk_t
*initchunk
;
495 struct sctp_chunk
*err_chunk
;
496 struct sctp_packet
*packet
;
498 if (!sctp_vtag_verify(chunk
, asoc
))
499 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
502 * An endpoint MUST NOT bundle INIT, INIT ACK or
503 * SHUTDOWN COMPLETE with any other chunks.
505 if (!chunk
->singleton
)
506 return sctp_sf_violation_chunk(ep
, asoc
, type
, arg
, commands
);
508 /* Make sure that the INIT-ACK chunk has a valid length */
509 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_initack_chunk_t
)))
510 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
512 /* Grab the INIT header. */
513 chunk
->subh
.init_hdr
= (sctp_inithdr_t
*) chunk
->skb
->data
;
515 /* Verify the INIT chunk before processing it. */
517 if (!sctp_verify_init(asoc
, chunk
->chunk_hdr
->type
,
518 (sctp_init_chunk_t
*)chunk
->chunk_hdr
, chunk
,
521 sctp_error_t error
= SCTP_ERROR_NO_RESOURCE
;
523 /* This chunk contains fatal error. It is to be discarded.
524 * Send an ABORT, with causes. If there are no causes,
525 * then there wasn't enough memory. Just terminate
529 packet
= sctp_abort_pkt_new(ep
, asoc
, arg
,
530 (__u8
*)(err_chunk
->chunk_hdr
) +
531 sizeof(sctp_chunkhdr_t
),
532 ntohs(err_chunk
->chunk_hdr
->length
) -
533 sizeof(sctp_chunkhdr_t
));
535 sctp_chunk_free(err_chunk
);
538 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
539 SCTP_PACKET(packet
));
540 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
541 error
= SCTP_ERROR_INV_PARAM
;
545 /* SCTP-AUTH, Section 6.3:
546 * It should be noted that if the receiver wants to tear
547 * down an association in an authenticated way only, the
548 * handling of malformed packets should not result in
549 * tearing down the association.
551 * This means that if we only want to abort associations
552 * in an authenticated way (i.e AUTH+ABORT), then we
553 * can't destroy this association just because the packet
556 if (sctp_auth_recv_cid(SCTP_CID_ABORT
, asoc
))
557 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
559 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
560 return sctp_stop_t1_and_abort(commands
, error
, ECONNREFUSED
,
561 asoc
, chunk
->transport
);
564 /* Tag the variable length parameters. Note that we never
565 * convert the parameters in an INIT chunk.
567 chunk
->param_hdr
.v
= skb_pull(chunk
->skb
, sizeof(sctp_inithdr_t
));
569 initchunk
= (sctp_init_chunk_t
*) chunk
->chunk_hdr
;
571 sctp_add_cmd_sf(commands
, SCTP_CMD_PEER_INIT
,
572 SCTP_PEER_INIT(initchunk
));
574 /* Reset init error count upon receipt of INIT-ACK. */
575 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_COUNTER_RESET
, SCTP_NULL());
577 /* 5.1 C) "A" shall stop the T1-init timer and leave
578 * COOKIE-WAIT state. "A" shall then ... start the T1-cookie
579 * timer, and enter the COOKIE-ECHOED state.
581 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
582 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
583 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
584 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
585 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
586 SCTP_STATE(SCTP_STATE_COOKIE_ECHOED
));
588 /* SCTP-AUTH: genereate the assocition shared keys so that
589 * we can potentially signe the COOKIE-ECHO.
591 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_SHKEY
, SCTP_NULL());
593 /* 5.1 C) "A" shall then send the State Cookie received in the
594 * INIT ACK chunk in a COOKIE ECHO chunk, ...
596 /* If there is any errors to report, send the ERROR chunk generated
597 * for unknown parameters as well.
599 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_COOKIE_ECHO
,
600 SCTP_CHUNK(err_chunk
));
602 return SCTP_DISPOSITION_CONSUME
;
606 * Respond to a normal COOKIE ECHO chunk.
607 * We are the side that is being asked for an association.
609 * Section: 5.1 Normal Establishment of an Association, D
610 * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply
611 * with a COOKIE ACK chunk after building a TCB and moving to
612 * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with
613 * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK
614 * chunk MUST be the first chunk in the packet.
616 * IMPLEMENTATION NOTE: An implementation may choose to send the
617 * Communication Up notification to the SCTP user upon reception
618 * of a valid COOKIE ECHO chunk.
620 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
621 * D) Rules for packet carrying a COOKIE ECHO
623 * - When sending a COOKIE ECHO, the endpoint MUST use the value of the
624 * Initial Tag received in the INIT ACK.
626 * - The receiver of a COOKIE ECHO follows the procedures in Section 5.
629 * (endpoint, asoc, chunk)
632 * (asoc, reply_msg, msg_up, timers, counters)
634 * The return value is the disposition of the chunk.
636 sctp_disposition_t
sctp_sf_do_5_1D_ce(const struct sctp_endpoint
*ep
,
637 const struct sctp_association
*asoc
,
638 const sctp_subtype_t type
, void *arg
,
639 sctp_cmd_seq_t
*commands
)
641 struct sctp_chunk
*chunk
= arg
;
642 struct sctp_association
*new_asoc
;
643 sctp_init_chunk_t
*peer_init
;
644 struct sctp_chunk
*repl
;
645 struct sctp_ulpevent
*ev
, *ai_ev
= NULL
;
647 struct sctp_chunk
*err_chk_p
;
650 /* If the packet is an OOTB packet which is temporarily on the
651 * control endpoint, respond with an ABORT.
653 if (ep
== sctp_sk((sctp_get_ctl_sock()))->ep
) {
654 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES
);
655 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
, commands
);
658 /* Make sure that the COOKIE_ECHO chunk has a valid length.
659 * In this case, we check that we have enough for at least a
660 * chunk header. More detailed verification is done
661 * in sctp_unpack_cookie().
663 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
664 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
666 /* If the endpoint is not listening or if the number of associations
667 * on the TCP-style socket exceed the max backlog, respond with an
671 if (!sctp_sstate(sk
, LISTENING
) ||
672 (sctp_style(sk
, TCP
) && sk_acceptq_is_full(sk
)))
673 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
, commands
);
675 /* "Decode" the chunk. We have no optional parameters so we
678 chunk
->subh
.cookie_hdr
=
679 (struct sctp_signed_cookie
*)chunk
->skb
->data
;
680 if (!pskb_pull(chunk
->skb
, ntohs(chunk
->chunk_hdr
->length
) -
681 sizeof(sctp_chunkhdr_t
)))
684 /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
685 * "Z" will reply with a COOKIE ACK chunk after building a TCB
686 * and moving to the ESTABLISHED state.
688 new_asoc
= sctp_unpack_cookie(ep
, asoc
, chunk
, GFP_ATOMIC
, &error
,
692 * If the re-build failed, what is the proper error path
695 * [We should abort the association. --piggy]
698 /* FIXME: Several errors are possible. A bad cookie should
699 * be silently discarded, but think about logging it too.
702 case -SCTP_IERROR_NOMEM
:
705 case -SCTP_IERROR_STALE_COOKIE
:
706 sctp_send_stale_cookie_err(ep
, asoc
, chunk
, commands
,
708 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
710 case -SCTP_IERROR_BAD_SIG
:
712 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
717 /* Delay state machine commands until later.
719 * Re-build the bind address for the association is done in
720 * the sctp_unpack_cookie() already.
722 /* This is a brand-new association, so these are not yet side
723 * effects--it is safe to run them here.
725 peer_init
= &chunk
->subh
.cookie_hdr
->c
.peer_init
[0];
727 if (!sctp_process_init(new_asoc
, chunk
,
728 &chunk
->subh
.cookie_hdr
->c
.peer_addr
,
729 peer_init
, GFP_ATOMIC
))
732 /* SCTP-AUTH: Now that we've populate required fields in
733 * sctp_process_init, set up the assocaition shared keys as
734 * necessary so that we can potentially authenticate the ACK
736 error
= sctp_auth_asoc_init_active_key(new_asoc
, GFP_ATOMIC
);
740 /* SCTP-AUTH: auth_chunk pointer is only set when the cookie-echo
741 * is supposed to be authenticated and we have to do delayed
742 * authentication. We've just recreated the association using
743 * the information in the cookie and now it's much easier to
744 * do the authentication.
746 if (chunk
->auth_chunk
) {
747 struct sctp_chunk auth
;
750 /* set-up our fake chunk so that we can process it */
751 auth
.skb
= chunk
->auth_chunk
;
752 auth
.asoc
= chunk
->asoc
;
753 auth
.sctp_hdr
= chunk
->sctp_hdr
;
754 auth
.chunk_hdr
= (sctp_chunkhdr_t
*)skb_push(chunk
->auth_chunk
,
755 sizeof(sctp_chunkhdr_t
));
756 skb_pull(chunk
->auth_chunk
, sizeof(sctp_chunkhdr_t
));
757 auth
.transport
= chunk
->transport
;
759 ret
= sctp_sf_authenticate(ep
, new_asoc
, type
, &auth
);
761 /* We can now safely free the auth_chunk clone */
762 kfree_skb(chunk
->auth_chunk
);
764 if (ret
!= SCTP_IERROR_NO_ERROR
) {
765 sctp_association_free(new_asoc
);
766 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
770 repl
= sctp_make_cookie_ack(new_asoc
, chunk
);
774 /* RFC 2960 5.1 Normal Establishment of an Association
776 * D) IMPLEMENTATION NOTE: An implementation may choose to
777 * send the Communication Up notification to the SCTP user
778 * upon reception of a valid COOKIE ECHO chunk.
780 ev
= sctp_ulpevent_make_assoc_change(new_asoc
, 0, SCTP_COMM_UP
, 0,
781 new_asoc
->c
.sinit_num_ostreams
,
782 new_asoc
->c
.sinit_max_instreams
,
787 /* Sockets API Draft Section 5.3.1.6
788 * When a peer sends a Adaptation Layer Indication parameter , SCTP
789 * delivers this notification to inform the application that of the
790 * peers requested adaptation layer.
792 if (new_asoc
->peer
.adaptation_ind
) {
793 ai_ev
= sctp_ulpevent_make_adaptation_indication(new_asoc
,
799 /* Add all the state machine commands now since we've created
800 * everything. This way we don't introduce memory corruptions
801 * during side-effect processing and correclty count established
804 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(new_asoc
));
805 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
806 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
807 SCTP_INC_STATS(SCTP_MIB_CURRESTAB
);
808 SCTP_INC_STATS(SCTP_MIB_PASSIVEESTABS
);
809 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_START
, SCTP_NULL());
811 if (new_asoc
->autoclose
)
812 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
813 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
815 /* This will send the COOKIE ACK */
816 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
818 /* Queue the ASSOC_CHANGE event */
819 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
821 /* Send up the Adaptation Layer Indication event */
823 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
824 SCTP_ULPEVENT(ai_ev
));
826 return SCTP_DISPOSITION_CONSUME
;
829 sctp_ulpevent_free(ev
);
831 sctp_chunk_free(repl
);
833 sctp_association_free(new_asoc
);
835 return SCTP_DISPOSITION_NOMEM
;
839 * Respond to a normal COOKIE ACK chunk.
840 * We are the side that is being asked for an association.
842 * RFC 2960 5.1 Normal Establishment of an Association
844 * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the
845 * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie
846 * timer. It may also notify its ULP about the successful
847 * establishment of the association with a Communication Up
848 * notification (see Section 10).
852 * (endpoint, asoc, chunk)
855 * (asoc, reply_msg, msg_up, timers, counters)
857 * The return value is the disposition of the chunk.
859 sctp_disposition_t
sctp_sf_do_5_1E_ca(const struct sctp_endpoint
*ep
,
860 const struct sctp_association
*asoc
,
861 const sctp_subtype_t type
, void *arg
,
862 sctp_cmd_seq_t
*commands
)
864 struct sctp_chunk
*chunk
= arg
;
865 struct sctp_ulpevent
*ev
;
867 if (!sctp_vtag_verify(chunk
, asoc
))
868 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
870 /* Verify that the chunk length for the COOKIE-ACK is OK.
871 * If we don't do this, any bundled chunks may be junked.
873 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
874 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
877 /* Reset init error count upon receipt of COOKIE-ACK,
878 * to avoid problems with the managemement of this
879 * counter in stale cookie situations when a transition back
880 * from the COOKIE-ECHOED state to the COOKIE-WAIT
881 * state is performed.
883 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_COUNTER_RESET
, SCTP_NULL());
885 /* RFC 2960 5.1 Normal Establishment of an Association
887 * E) Upon reception of the COOKIE ACK, endpoint "A" will move
888 * from the COOKIE-ECHOED state to the ESTABLISHED state,
889 * stopping the T1-cookie timer.
891 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
892 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
893 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
894 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
895 SCTP_INC_STATS(SCTP_MIB_CURRESTAB
);
896 SCTP_INC_STATS(SCTP_MIB_ACTIVEESTABS
);
897 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_START
, SCTP_NULL());
899 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
900 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
902 /* It may also notify its ULP about the successful
903 * establishment of the association with a Communication Up
904 * notification (see Section 10).
906 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_COMM_UP
,
907 0, asoc
->c
.sinit_num_ostreams
,
908 asoc
->c
.sinit_max_instreams
,
914 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
916 /* Sockets API Draft Section 5.3.1.6
917 * When a peer sends a Adaptation Layer Indication parameter , SCTP
918 * delivers this notification to inform the application that of the
919 * peers requested adaptation layer.
921 if (asoc
->peer
.adaptation_ind
) {
922 ev
= sctp_ulpevent_make_adaptation_indication(asoc
, GFP_ATOMIC
);
926 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
930 return SCTP_DISPOSITION_CONSUME
;
932 return SCTP_DISPOSITION_NOMEM
;
935 /* Generate and sendout a heartbeat packet. */
936 static sctp_disposition_t
sctp_sf_heartbeat(const struct sctp_endpoint
*ep
,
937 const struct sctp_association
*asoc
,
938 const sctp_subtype_t type
,
940 sctp_cmd_seq_t
*commands
)
942 struct sctp_transport
*transport
= (struct sctp_transport
*) arg
;
943 struct sctp_chunk
*reply
;
945 /* Send a heartbeat to our peer. */
946 reply
= sctp_make_heartbeat(asoc
, transport
);
948 return SCTP_DISPOSITION_NOMEM
;
950 /* Set rto_pending indicating that an RTT measurement
951 * is started with this heartbeat chunk.
953 sctp_add_cmd_sf(commands
, SCTP_CMD_RTO_PENDING
,
954 SCTP_TRANSPORT(transport
));
956 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
957 return SCTP_DISPOSITION_CONSUME
;
960 /* Generate a HEARTBEAT packet on the given transport. */
961 sctp_disposition_t
sctp_sf_sendbeat_8_3(const struct sctp_endpoint
*ep
,
962 const struct sctp_association
*asoc
,
963 const sctp_subtype_t type
,
965 sctp_cmd_seq_t
*commands
)
967 struct sctp_transport
*transport
= (struct sctp_transport
*) arg
;
969 if (asoc
->overall_error_count
>= asoc
->max_retrans
) {
970 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
971 SCTP_ERROR(ETIMEDOUT
));
972 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
973 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
974 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
975 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
976 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
977 return SCTP_DISPOSITION_DELETE_TCB
;
981 * The Sender-specific Heartbeat Info field should normally include
982 * information about the sender's current time when this HEARTBEAT
983 * chunk is sent and the destination transport address to which this
984 * HEARTBEAT is sent (see Section 8.3).
987 if (transport
->param_flags
& SPP_HB_ENABLE
) {
988 if (SCTP_DISPOSITION_NOMEM
==
989 sctp_sf_heartbeat(ep
, asoc
, type
, arg
,
991 return SCTP_DISPOSITION_NOMEM
;
993 /* Set transport error counter and association error counter
994 * when sending heartbeat.
996 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSPORT_HB_SENT
,
997 SCTP_TRANSPORT(transport
));
999 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSPORT_IDLE
,
1000 SCTP_TRANSPORT(transport
));
1001 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMER_UPDATE
,
1002 SCTP_TRANSPORT(transport
));
1004 return SCTP_DISPOSITION_CONSUME
;
1008 * Process an heartbeat request.
1010 * Section: 8.3 Path Heartbeat
1011 * The receiver of the HEARTBEAT should immediately respond with a
1012 * HEARTBEAT ACK that contains the Heartbeat Information field copied
1013 * from the received HEARTBEAT chunk.
1015 * Verification Tag: 8.5 Verification Tag [Normal verification]
1016 * When receiving an SCTP packet, the endpoint MUST ensure that the
1017 * value in the Verification Tag field of the received SCTP packet
1018 * matches its own Tag. If the received Verification Tag value does not
1019 * match the receiver's own tag value, the receiver shall silently
1020 * discard the packet and shall not process it any further except for
1021 * those cases listed in Section 8.5.1 below.
1024 * (endpoint, asoc, chunk)
1027 * (asoc, reply_msg, msg_up, timers, counters)
1029 * The return value is the disposition of the chunk.
1031 sctp_disposition_t
sctp_sf_beat_8_3(const struct sctp_endpoint
*ep
,
1032 const struct sctp_association
*asoc
,
1033 const sctp_subtype_t type
,
1035 sctp_cmd_seq_t
*commands
)
1037 struct sctp_chunk
*chunk
= arg
;
1038 struct sctp_chunk
*reply
;
1041 if (!sctp_vtag_verify(chunk
, asoc
))
1042 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
1044 /* Make sure that the HEARTBEAT chunk has a valid length. */
1045 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_heartbeat_chunk_t
)))
1046 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
1049 /* 8.3 The receiver of the HEARTBEAT should immediately
1050 * respond with a HEARTBEAT ACK that contains the Heartbeat
1051 * Information field copied from the received HEARTBEAT chunk.
1053 chunk
->subh
.hb_hdr
= (sctp_heartbeathdr_t
*) chunk
->skb
->data
;
1054 paylen
= ntohs(chunk
->chunk_hdr
->length
) - sizeof(sctp_chunkhdr_t
);
1055 if (!pskb_pull(chunk
->skb
, paylen
))
1058 reply
= sctp_make_heartbeat_ack(asoc
, chunk
,
1059 chunk
->subh
.hb_hdr
, paylen
);
1063 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
1064 return SCTP_DISPOSITION_CONSUME
;
1067 return SCTP_DISPOSITION_NOMEM
;
1071 * Process the returning HEARTBEAT ACK.
1073 * Section: 8.3 Path Heartbeat
1074 * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT
1075 * should clear the error counter of the destination transport
1076 * address to which the HEARTBEAT was sent, and mark the destination
1077 * transport address as active if it is not so marked. The endpoint may
1078 * optionally report to the upper layer when an inactive destination
1079 * address is marked as active due to the reception of the latest
1080 * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also
1081 * clear the association overall error count as well (as defined
1084 * The receiver of the HEARTBEAT ACK should also perform an RTT
1085 * measurement for that destination transport address using the time
1086 * value carried in the HEARTBEAT ACK chunk.
1088 * Verification Tag: 8.5 Verification Tag [Normal verification]
1091 * (endpoint, asoc, chunk)
1094 * (asoc, reply_msg, msg_up, timers, counters)
1096 * The return value is the disposition of the chunk.
1098 sctp_disposition_t
sctp_sf_backbeat_8_3(const struct sctp_endpoint
*ep
,
1099 const struct sctp_association
*asoc
,
1100 const sctp_subtype_t type
,
1102 sctp_cmd_seq_t
*commands
)
1104 struct sctp_chunk
*chunk
= arg
;
1105 union sctp_addr from_addr
;
1106 struct sctp_transport
*link
;
1107 sctp_sender_hb_info_t
*hbinfo
;
1108 unsigned long max_interval
;
1110 if (!sctp_vtag_verify(chunk
, asoc
))
1111 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
1113 /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */
1114 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
) +
1115 sizeof(sctp_sender_hb_info_t
)))
1116 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
1119 hbinfo
= (sctp_sender_hb_info_t
*) chunk
->skb
->data
;
1120 /* Make sure that the length of the parameter is what we expect */
1121 if (ntohs(hbinfo
->param_hdr
.length
) !=
1122 sizeof(sctp_sender_hb_info_t
)) {
1123 return SCTP_DISPOSITION_DISCARD
;
1126 from_addr
= hbinfo
->daddr
;
1127 link
= sctp_assoc_lookup_paddr(asoc
, &from_addr
);
1129 /* This should never happen, but lets log it if so. */
1130 if (unlikely(!link
)) {
1131 if (from_addr
.sa
.sa_family
== AF_INET6
) {
1132 if (net_ratelimit())
1133 pr_warn("%s association %p could not find address %pI6\n",
1136 &from_addr
.v6
.sin6_addr
);
1138 if (net_ratelimit())
1139 pr_warn("%s association %p could not find address %pI4\n",
1142 &from_addr
.v4
.sin_addr
.s_addr
);
1144 return SCTP_DISPOSITION_DISCARD
;
1147 /* Validate the 64-bit random nonce. */
1148 if (hbinfo
->hb_nonce
!= link
->hb_nonce
)
1149 return SCTP_DISPOSITION_DISCARD
;
1151 max_interval
= link
->hbinterval
+ link
->rto
;
1153 /* Check if the timestamp looks valid. */
1154 if (time_after(hbinfo
->sent_at
, jiffies
) ||
1155 time_after(jiffies
, hbinfo
->sent_at
+ max_interval
)) {
1156 SCTP_DEBUG_PRINTK("%s: HEARTBEAT ACK with invalid timestamp "
1157 "received for transport: %p\n",
1159 return SCTP_DISPOSITION_DISCARD
;
1162 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of
1163 * the HEARTBEAT should clear the error counter of the
1164 * destination transport address to which the HEARTBEAT was
1165 * sent and mark the destination transport address as active if
1166 * it is not so marked.
1168 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSPORT_ON
, SCTP_TRANSPORT(link
));
1170 return SCTP_DISPOSITION_CONSUME
;
1173 /* Helper function to send out an abort for the restart
1176 static int sctp_sf_send_restart_abort(union sctp_addr
*ssa
,
1177 struct sctp_chunk
*init
,
1178 sctp_cmd_seq_t
*commands
)
1181 struct sctp_packet
*pkt
;
1182 union sctp_addr_param
*addrparm
;
1183 struct sctp_errhdr
*errhdr
;
1184 struct sctp_endpoint
*ep
;
1185 char buffer
[sizeof(struct sctp_errhdr
)+sizeof(union sctp_addr_param
)];
1186 struct sctp_af
*af
= sctp_get_af_specific(ssa
->v4
.sin_family
);
1188 /* Build the error on the stack. We are way to malloc crazy
1189 * throughout the code today.
1191 errhdr
= (struct sctp_errhdr
*)buffer
;
1192 addrparm
= (union sctp_addr_param
*)errhdr
->variable
;
1194 /* Copy into a parm format. */
1195 len
= af
->to_addr_param(ssa
, addrparm
);
1196 len
+= sizeof(sctp_errhdr_t
);
1198 errhdr
->cause
= SCTP_ERROR_RESTART
;
1199 errhdr
->length
= htons(len
);
1201 /* Assign to the control socket. */
1202 ep
= sctp_sk((sctp_get_ctl_sock()))->ep
;
1204 /* Association is NULL since this may be a restart attack and we
1205 * want to send back the attacker's vtag.
1207 pkt
= sctp_abort_pkt_new(ep
, NULL
, init
, errhdr
, len
);
1211 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
, SCTP_PACKET(pkt
));
1213 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
1215 /* Discard the rest of the inbound packet. */
1216 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
, SCTP_NULL());
1219 /* Even if there is no memory, treat as a failure so
1220 * the packet will get dropped.
1225 static bool list_has_sctp_addr(const struct list_head
*list
,
1226 union sctp_addr
*ipaddr
)
1228 struct sctp_transport
*addr
;
1230 list_for_each_entry(addr
, list
, transports
) {
1231 if (sctp_cmp_addr_exact(ipaddr
, &addr
->ipaddr
))
1237 /* A restart is occurring, check to make sure no new addresses
1238 * are being added as we may be under a takeover attack.
1240 static int sctp_sf_check_restart_addrs(const struct sctp_association
*new_asoc
,
1241 const struct sctp_association
*asoc
,
1242 struct sctp_chunk
*init
,
1243 sctp_cmd_seq_t
*commands
)
1245 struct sctp_transport
*new_addr
;
1248 /* Implementor's Guide - Section 5.2.2
1250 * Before responding the endpoint MUST check to see if the
1251 * unexpected INIT adds new addresses to the association. If new
1252 * addresses are added to the association, the endpoint MUST respond
1256 /* Search through all current addresses and make sure
1257 * we aren't adding any new ones.
1259 list_for_each_entry(new_addr
, &new_asoc
->peer
.transport_addr_list
,
1261 if (!list_has_sctp_addr(&asoc
->peer
.transport_addr_list
,
1262 &new_addr
->ipaddr
)) {
1263 sctp_sf_send_restart_abort(&new_addr
->ipaddr
, init
,
1270 /* Return success if all addresses were found. */
1274 /* Populate the verification/tie tags based on overlapping INIT
1277 * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state.
1279 static void sctp_tietags_populate(struct sctp_association
*new_asoc
,
1280 const struct sctp_association
*asoc
)
1282 switch (asoc
->state
) {
1284 /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */
1286 case SCTP_STATE_COOKIE_WAIT
:
1287 new_asoc
->c
.my_vtag
= asoc
->c
.my_vtag
;
1288 new_asoc
->c
.my_ttag
= asoc
->c
.my_vtag
;
1289 new_asoc
->c
.peer_ttag
= 0;
1292 case SCTP_STATE_COOKIE_ECHOED
:
1293 new_asoc
->c
.my_vtag
= asoc
->c
.my_vtag
;
1294 new_asoc
->c
.my_ttag
= asoc
->c
.my_vtag
;
1295 new_asoc
->c
.peer_ttag
= asoc
->c
.peer_vtag
;
1298 /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED,
1299 * COOKIE-WAIT and SHUTDOWN-ACK-SENT
1302 new_asoc
->c
.my_ttag
= asoc
->c
.my_vtag
;
1303 new_asoc
->c
.peer_ttag
= asoc
->c
.peer_vtag
;
1307 /* Other parameters for the endpoint SHOULD be copied from the
1308 * existing parameters of the association (e.g. number of
1309 * outbound streams) into the INIT ACK and cookie.
1311 new_asoc
->rwnd
= asoc
->rwnd
;
1312 new_asoc
->c
.sinit_num_ostreams
= asoc
->c
.sinit_num_ostreams
;
1313 new_asoc
->c
.sinit_max_instreams
= asoc
->c
.sinit_max_instreams
;
1314 new_asoc
->c
.initial_tsn
= asoc
->c
.initial_tsn
;
1318 * Compare vtag/tietag values to determine unexpected COOKIE-ECHO
1321 * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists.
1323 * Returns value representing action to be taken. These action values
1324 * correspond to Action/Description values in RFC 2960, Table 2.
1326 static char sctp_tietags_compare(struct sctp_association
*new_asoc
,
1327 const struct sctp_association
*asoc
)
1329 /* In this case, the peer may have restarted. */
1330 if ((asoc
->c
.my_vtag
!= new_asoc
->c
.my_vtag
) &&
1331 (asoc
->c
.peer_vtag
!= new_asoc
->c
.peer_vtag
) &&
1332 (asoc
->c
.my_vtag
== new_asoc
->c
.my_ttag
) &&
1333 (asoc
->c
.peer_vtag
== new_asoc
->c
.peer_ttag
))
1336 /* Collision case B. */
1337 if ((asoc
->c
.my_vtag
== new_asoc
->c
.my_vtag
) &&
1338 ((asoc
->c
.peer_vtag
!= new_asoc
->c
.peer_vtag
) ||
1339 (0 == asoc
->c
.peer_vtag
))) {
1343 /* Collision case D. */
1344 if ((asoc
->c
.my_vtag
== new_asoc
->c
.my_vtag
) &&
1345 (asoc
->c
.peer_vtag
== new_asoc
->c
.peer_vtag
))
1348 /* Collision case C. */
1349 if ((asoc
->c
.my_vtag
!= new_asoc
->c
.my_vtag
) &&
1350 (asoc
->c
.peer_vtag
== new_asoc
->c
.peer_vtag
) &&
1351 (0 == new_asoc
->c
.my_ttag
) &&
1352 (0 == new_asoc
->c
.peer_ttag
))
1355 /* No match to any of the special cases; discard this packet. */
1359 /* Common helper routine for both duplicate and simulataneous INIT
1362 static sctp_disposition_t
sctp_sf_do_unexpected_init(
1363 const struct sctp_endpoint
*ep
,
1364 const struct sctp_association
*asoc
,
1365 const sctp_subtype_t type
,
1366 void *arg
, sctp_cmd_seq_t
*commands
)
1368 sctp_disposition_t retval
;
1369 struct sctp_chunk
*chunk
= arg
;
1370 struct sctp_chunk
*repl
;
1371 struct sctp_association
*new_asoc
;
1372 struct sctp_chunk
*err_chunk
;
1373 struct sctp_packet
*packet
;
1374 sctp_unrecognized_param_t
*unk_param
;
1378 * An endpoint MUST NOT bundle INIT, INIT ACK or
1379 * SHUTDOWN COMPLETE with any other chunks.
1382 * Furthermore, we require that the receiver of an INIT chunk MUST
1383 * enforce these rules by silently discarding an arriving packet
1384 * with an INIT chunk that is bundled with other chunks.
1386 if (!chunk
->singleton
)
1387 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
1389 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
1392 if (chunk
->sctp_hdr
->vtag
!= 0)
1393 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
, commands
);
1395 /* Make sure that the INIT chunk has a valid length.
1396 * In this case, we generate a protocol violation since we have
1397 * an association established.
1399 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_init_chunk_t
)))
1400 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
1402 /* Grab the INIT header. */
1403 chunk
->subh
.init_hdr
= (sctp_inithdr_t
*) chunk
->skb
->data
;
1405 /* Tag the variable length parameters. */
1406 chunk
->param_hdr
.v
= skb_pull(chunk
->skb
, sizeof(sctp_inithdr_t
));
1408 /* Verify the INIT chunk before processing it. */
1410 if (!sctp_verify_init(asoc
, chunk
->chunk_hdr
->type
,
1411 (sctp_init_chunk_t
*)chunk
->chunk_hdr
, chunk
,
1413 /* This chunk contains fatal error. It is to be discarded.
1414 * Send an ABORT, with causes if there is any.
1417 packet
= sctp_abort_pkt_new(ep
, asoc
, arg
,
1418 (__u8
*)(err_chunk
->chunk_hdr
) +
1419 sizeof(sctp_chunkhdr_t
),
1420 ntohs(err_chunk
->chunk_hdr
->length
) -
1421 sizeof(sctp_chunkhdr_t
));
1424 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
1425 SCTP_PACKET(packet
));
1426 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
1427 retval
= SCTP_DISPOSITION_CONSUME
;
1429 retval
= SCTP_DISPOSITION_NOMEM
;
1433 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
,
1439 * Other parameters for the endpoint SHOULD be copied from the
1440 * existing parameters of the association (e.g. number of
1441 * outbound streams) into the INIT ACK and cookie.
1442 * FIXME: We are copying parameters from the endpoint not the
1445 new_asoc
= sctp_make_temp_asoc(ep
, chunk
, GFP_ATOMIC
);
1449 if (sctp_assoc_set_bind_addr_from_ep(new_asoc
,
1450 sctp_scope(sctp_source(chunk
)), GFP_ATOMIC
) < 0)
1453 /* In the outbound INIT ACK the endpoint MUST copy its current
1454 * Verification Tag and Peers Verification tag into a reserved
1455 * place (local tie-tag and per tie-tag) within the state cookie.
1457 if (!sctp_process_init(new_asoc
, chunk
, sctp_source(chunk
),
1458 (sctp_init_chunk_t
*)chunk
->chunk_hdr
,
1462 /* Make sure no new addresses are being added during the
1463 * restart. Do not do this check for COOKIE-WAIT state,
1464 * since there are no peer addresses to check against.
1465 * Upon return an ABORT will have been sent if needed.
1467 if (!sctp_state(asoc
, COOKIE_WAIT
)) {
1468 if (!sctp_sf_check_restart_addrs(new_asoc
, asoc
, chunk
,
1470 retval
= SCTP_DISPOSITION_CONSUME
;
1475 sctp_tietags_populate(new_asoc
, asoc
);
1477 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
1479 /* If there are errors need to be reported for unknown parameters,
1480 * make sure to reserve enough room in the INIT ACK for them.
1484 len
= ntohs(err_chunk
->chunk_hdr
->length
) -
1485 sizeof(sctp_chunkhdr_t
);
1488 repl
= sctp_make_init_ack(new_asoc
, chunk
, GFP_ATOMIC
, len
);
1492 /* If there are errors need to be reported for unknown parameters,
1493 * include them in the outgoing INIT ACK as "Unrecognized parameter"
1497 /* Get the "Unrecognized parameter" parameter(s) out of the
1498 * ERROR chunk generated by sctp_verify_init(). Since the
1499 * error cause code for "unknown parameter" and the
1500 * "Unrecognized parameter" type is the same, we can
1501 * construct the parameters in INIT ACK by copying the
1502 * ERROR causes over.
1504 unk_param
= (sctp_unrecognized_param_t
*)
1505 ((__u8
*)(err_chunk
->chunk_hdr
) +
1506 sizeof(sctp_chunkhdr_t
));
1507 /* Replace the cause code with the "Unrecognized parameter"
1510 sctp_addto_chunk(repl
, len
, unk_param
);
1513 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(new_asoc
));
1514 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1517 * Note: After sending out INIT ACK with the State Cookie parameter,
1518 * "Z" MUST NOT allocate any resources for this new association.
1519 * Otherwise, "Z" will be vulnerable to resource attacks.
1521 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
1522 retval
= SCTP_DISPOSITION_CONSUME
;
1527 retval
= SCTP_DISPOSITION_NOMEM
;
1530 sctp_association_free(new_asoc
);
1533 sctp_chunk_free(err_chunk
);
1538 * Handle simultaneous INIT.
1539 * This means we started an INIT and then we got an INIT request from
1542 * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B)
1543 * This usually indicates an initialization collision, i.e., each
1544 * endpoint is attempting, at about the same time, to establish an
1545 * association with the other endpoint.
1547 * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an
1548 * endpoint MUST respond with an INIT ACK using the same parameters it
1549 * sent in its original INIT chunk (including its Verification Tag,
1550 * unchanged). These original parameters are combined with those from the
1551 * newly received INIT chunk. The endpoint shall also generate a State
1552 * Cookie with the INIT ACK. The endpoint uses the parameters sent in its
1553 * INIT to calculate the State Cookie.
1555 * After that, the endpoint MUST NOT change its state, the T1-init
1556 * timer shall be left running and the corresponding TCB MUST NOT be
1557 * destroyed. The normal procedures for handling State Cookies when
1558 * a TCB exists will resolve the duplicate INITs to a single association.
1560 * For an endpoint that is in the COOKIE-ECHOED state it MUST populate
1561 * its Tie-Tags with the Tag information of itself and its peer (see
1562 * section 5.2.2 for a description of the Tie-Tags).
1564 * Verification Tag: Not explicit, but an INIT can not have a valid
1565 * verification tag, so we skip the check.
1568 * (endpoint, asoc, chunk)
1571 * (asoc, reply_msg, msg_up, timers, counters)
1573 * The return value is the disposition of the chunk.
1575 sctp_disposition_t
sctp_sf_do_5_2_1_siminit(const struct sctp_endpoint
*ep
,
1576 const struct sctp_association
*asoc
,
1577 const sctp_subtype_t type
,
1579 sctp_cmd_seq_t
*commands
)
1581 /* Call helper to do the real work for both simulataneous and
1582 * duplicate INIT chunk handling.
1584 return sctp_sf_do_unexpected_init(ep
, asoc
, type
, arg
, commands
);
1588 * Handle duplicated INIT messages. These are usually delayed
1591 * Section: 5.2.2 Unexpected INIT in States Other than CLOSED,
1592 * COOKIE-ECHOED and COOKIE-WAIT
1594 * Unless otherwise stated, upon reception of an unexpected INIT for
1595 * this association, the endpoint shall generate an INIT ACK with a
1596 * State Cookie. In the outbound INIT ACK the endpoint MUST copy its
1597 * current Verification Tag and peer's Verification Tag into a reserved
1598 * place within the state cookie. We shall refer to these locations as
1599 * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet
1600 * containing this INIT ACK MUST carry a Verification Tag value equal to
1601 * the Initiation Tag found in the unexpected INIT. And the INIT ACK
1602 * MUST contain a new Initiation Tag (randomly generated see Section
1603 * 5.3.1). Other parameters for the endpoint SHOULD be copied from the
1604 * existing parameters of the association (e.g. number of outbound
1605 * streams) into the INIT ACK and cookie.
1607 * After sending out the INIT ACK, the endpoint shall take no further
1608 * actions, i.e., the existing association, including its current state,
1609 * and the corresponding TCB MUST NOT be changed.
1611 * Note: Only when a TCB exists and the association is not in a COOKIE-
1612 * WAIT state are the Tie-Tags populated. For a normal association INIT
1613 * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be
1614 * set to 0 (indicating that no previous TCB existed). The INIT ACK and
1615 * State Cookie are populated as specified in section 5.2.1.
1617 * Verification Tag: Not specified, but an INIT has no way of knowing
1618 * what the verification tag could be, so we ignore it.
1621 * (endpoint, asoc, chunk)
1624 * (asoc, reply_msg, msg_up, timers, counters)
1626 * The return value is the disposition of the chunk.
1628 sctp_disposition_t
sctp_sf_do_5_2_2_dupinit(const struct sctp_endpoint
*ep
,
1629 const struct sctp_association
*asoc
,
1630 const sctp_subtype_t type
,
1632 sctp_cmd_seq_t
*commands
)
1634 /* Call helper to do the real work for both simulataneous and
1635 * duplicate INIT chunk handling.
1637 return sctp_sf_do_unexpected_init(ep
, asoc
, type
, arg
, commands
);
1642 * Unexpected INIT-ACK handler.
1645 * If an INIT ACK received by an endpoint in any state other than the
1646 * COOKIE-WAIT state, the endpoint should discard the INIT ACK chunk.
1647 * An unexpected INIT ACK usually indicates the processing of an old or
1648 * duplicated INIT chunk.
1650 sctp_disposition_t
sctp_sf_do_5_2_3_initack(const struct sctp_endpoint
*ep
,
1651 const struct sctp_association
*asoc
,
1652 const sctp_subtype_t type
,
1653 void *arg
, sctp_cmd_seq_t
*commands
)
1655 /* Per the above section, we'll discard the chunk if we have an
1656 * endpoint. If this is an OOTB INIT-ACK, treat it as such.
1658 if (ep
== sctp_sk((sctp_get_ctl_sock()))->ep
)
1659 return sctp_sf_ootb(ep
, asoc
, type
, arg
, commands
);
1661 return sctp_sf_discard_chunk(ep
, asoc
, type
, arg
, commands
);
1664 /* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A')
1667 * A) In this case, the peer may have restarted.
1669 static sctp_disposition_t
sctp_sf_do_dupcook_a(const struct sctp_endpoint
*ep
,
1670 const struct sctp_association
*asoc
,
1671 struct sctp_chunk
*chunk
,
1672 sctp_cmd_seq_t
*commands
,
1673 struct sctp_association
*new_asoc
)
1675 sctp_init_chunk_t
*peer_init
;
1676 struct sctp_ulpevent
*ev
;
1677 struct sctp_chunk
*repl
;
1678 struct sctp_chunk
*err
;
1679 sctp_disposition_t disposition
;
1681 /* new_asoc is a brand-new association, so these are not yet
1682 * side effects--it is safe to run them here.
1684 peer_init
= &chunk
->subh
.cookie_hdr
->c
.peer_init
[0];
1686 if (!sctp_process_init(new_asoc
, chunk
, sctp_source(chunk
), peer_init
,
1690 /* Make sure no new addresses are being added during the
1691 * restart. Though this is a pretty complicated attack
1692 * since you'd have to get inside the cookie.
1694 if (!sctp_sf_check_restart_addrs(new_asoc
, asoc
, chunk
, commands
)) {
1695 return SCTP_DISPOSITION_CONSUME
;
1698 /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes
1699 * the peer has restarted (Action A), it MUST NOT setup a new
1700 * association but instead resend the SHUTDOWN ACK and send an ERROR
1701 * chunk with a "Cookie Received while Shutting Down" error cause to
1704 if (sctp_state(asoc
, SHUTDOWN_ACK_SENT
)) {
1705 disposition
= sctp_sf_do_9_2_reshutack(ep
, asoc
,
1706 SCTP_ST_CHUNK(chunk
->chunk_hdr
->type
),
1708 if (SCTP_DISPOSITION_NOMEM
== disposition
)
1711 err
= sctp_make_op_error(asoc
, chunk
,
1712 SCTP_ERROR_COOKIE_IN_SHUTDOWN
,
1715 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
1718 return SCTP_DISPOSITION_CONSUME
;
1721 /* For now, fail any unsent/unacked data. Consider the optional
1722 * choice of resending of this data.
1724 sctp_add_cmd_sf(commands
, SCTP_CMD_PURGE_OUTQUEUE
, SCTP_NULL());
1726 repl
= sctp_make_cookie_ack(new_asoc
, chunk
);
1730 /* Report association restart to upper layer. */
1731 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_RESTART
, 0,
1732 new_asoc
->c
.sinit_num_ostreams
,
1733 new_asoc
->c
.sinit_max_instreams
,
1738 /* Update the content of current association. */
1739 sctp_add_cmd_sf(commands
, SCTP_CMD_UPDATE_ASSOC
, SCTP_ASOC(new_asoc
));
1740 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1741 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
1742 return SCTP_DISPOSITION_CONSUME
;
1745 sctp_chunk_free(repl
);
1747 return SCTP_DISPOSITION_NOMEM
;
1750 /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B')
1753 * B) In this case, both sides may be attempting to start an association
1754 * at about the same time but the peer endpoint started its INIT
1755 * after responding to the local endpoint's INIT
1757 /* This case represents an initialization collision. */
1758 static sctp_disposition_t
sctp_sf_do_dupcook_b(const struct sctp_endpoint
*ep
,
1759 const struct sctp_association
*asoc
,
1760 struct sctp_chunk
*chunk
,
1761 sctp_cmd_seq_t
*commands
,
1762 struct sctp_association
*new_asoc
)
1764 sctp_init_chunk_t
*peer_init
;
1765 struct sctp_chunk
*repl
;
1767 /* new_asoc is a brand-new association, so these are not yet
1768 * side effects--it is safe to run them here.
1770 peer_init
= &chunk
->subh
.cookie_hdr
->c
.peer_init
[0];
1771 if (!sctp_process_init(new_asoc
, chunk
, sctp_source(chunk
), peer_init
,
1775 /* Update the content of current association. */
1776 sctp_add_cmd_sf(commands
, SCTP_CMD_UPDATE_ASSOC
, SCTP_ASOC(new_asoc
));
1777 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
1778 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
1779 SCTP_INC_STATS(SCTP_MIB_CURRESTAB
);
1780 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_START
, SCTP_NULL());
1782 repl
= sctp_make_cookie_ack(new_asoc
, chunk
);
1786 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1788 /* RFC 2960 5.1 Normal Establishment of an Association
1790 * D) IMPLEMENTATION NOTE: An implementation may choose to
1791 * send the Communication Up notification to the SCTP user
1792 * upon reception of a valid COOKIE ECHO chunk.
1794 * Sadly, this needs to be implemented as a side-effect, because
1795 * we are not guaranteed to have set the association id of the real
1796 * association and so these notifications need to be delayed until
1797 * the association id is allocated.
1800 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_CHANGE
, SCTP_U8(SCTP_COMM_UP
));
1802 /* Sockets API Draft Section 5.3.1.6
1803 * When a peer sends a Adaptation Layer Indication parameter , SCTP
1804 * delivers this notification to inform the application that of the
1805 * peers requested adaptation layer.
1807 * This also needs to be done as a side effect for the same reason as
1810 if (asoc
->peer
.adaptation_ind
)
1811 sctp_add_cmd_sf(commands
, SCTP_CMD_ADAPTATION_IND
, SCTP_NULL());
1813 return SCTP_DISPOSITION_CONSUME
;
1816 return SCTP_DISPOSITION_NOMEM
;
1819 /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C')
1822 * C) In this case, the local endpoint's cookie has arrived late.
1823 * Before it arrived, the local endpoint sent an INIT and received an
1824 * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag
1825 * but a new tag of its own.
1827 /* This case represents an initialization collision. */
1828 static sctp_disposition_t
sctp_sf_do_dupcook_c(const struct sctp_endpoint
*ep
,
1829 const struct sctp_association
*asoc
,
1830 struct sctp_chunk
*chunk
,
1831 sctp_cmd_seq_t
*commands
,
1832 struct sctp_association
*new_asoc
)
1834 /* The cookie should be silently discarded.
1835 * The endpoint SHOULD NOT change states and should leave
1836 * any timers running.
1838 return SCTP_DISPOSITION_DISCARD
;
1841 /* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D')
1845 * D) When both local and remote tags match the endpoint should always
1846 * enter the ESTABLISHED state, if it has not already done so.
1848 /* This case represents an initialization collision. */
1849 static sctp_disposition_t
sctp_sf_do_dupcook_d(const struct sctp_endpoint
*ep
,
1850 const struct sctp_association
*asoc
,
1851 struct sctp_chunk
*chunk
,
1852 sctp_cmd_seq_t
*commands
,
1853 struct sctp_association
*new_asoc
)
1855 struct sctp_ulpevent
*ev
= NULL
, *ai_ev
= NULL
;
1856 struct sctp_chunk
*repl
;
1858 /* Clarification from Implementor's Guide:
1859 * D) When both local and remote tags match the endpoint should
1860 * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state.
1861 * It should stop any cookie timer that may be running and send
1865 /* Don't accidentally move back into established state. */
1866 if (asoc
->state
< SCTP_STATE_ESTABLISHED
) {
1867 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
1868 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
1869 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
1870 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
1871 SCTP_INC_STATS(SCTP_MIB_CURRESTAB
);
1872 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_START
,
1875 /* RFC 2960 5.1 Normal Establishment of an Association
1877 * D) IMPLEMENTATION NOTE: An implementation may choose
1878 * to send the Communication Up notification to the
1879 * SCTP user upon reception of a valid COOKIE
1882 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0,
1884 asoc
->c
.sinit_num_ostreams
,
1885 asoc
->c
.sinit_max_instreams
,
1890 /* Sockets API Draft Section 5.3.1.6
1891 * When a peer sends a Adaptation Layer Indication parameter,
1892 * SCTP delivers this notification to inform the application
1893 * that of the peers requested adaptation layer.
1895 if (asoc
->peer
.adaptation_ind
) {
1896 ai_ev
= sctp_ulpevent_make_adaptation_indication(asoc
,
1904 repl
= sctp_make_cookie_ack(new_asoc
, chunk
);
1908 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1911 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
1914 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
1915 SCTP_ULPEVENT(ai_ev
));
1917 return SCTP_DISPOSITION_CONSUME
;
1921 sctp_ulpevent_free(ai_ev
);
1923 sctp_ulpevent_free(ev
);
1924 return SCTP_DISPOSITION_NOMEM
;
1928 * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying
1929 * chunk was retransmitted and then delayed in the network.
1931 * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists
1933 * Verification Tag: None. Do cookie validation.
1936 * (endpoint, asoc, chunk)
1939 * (asoc, reply_msg, msg_up, timers, counters)
1941 * The return value is the disposition of the chunk.
1943 sctp_disposition_t
sctp_sf_do_5_2_4_dupcook(const struct sctp_endpoint
*ep
,
1944 const struct sctp_association
*asoc
,
1945 const sctp_subtype_t type
,
1947 sctp_cmd_seq_t
*commands
)
1949 sctp_disposition_t retval
;
1950 struct sctp_chunk
*chunk
= arg
;
1951 struct sctp_association
*new_asoc
;
1954 struct sctp_chunk
*err_chk_p
;
1956 /* Make sure that the chunk has a valid length from the protocol
1957 * perspective. In this case check to make sure we have at least
1958 * enough for the chunk header. Cookie length verification is
1961 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
1962 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
1965 /* "Decode" the chunk. We have no optional parameters so we
1966 * are in good shape.
1968 chunk
->subh
.cookie_hdr
= (struct sctp_signed_cookie
*)chunk
->skb
->data
;
1969 if (!pskb_pull(chunk
->skb
, ntohs(chunk
->chunk_hdr
->length
) -
1970 sizeof(sctp_chunkhdr_t
)))
1973 /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
1974 * of a duplicate COOKIE ECHO match the Verification Tags of the
1975 * current association, consider the State Cookie valid even if
1976 * the lifespan is exceeded.
1978 new_asoc
= sctp_unpack_cookie(ep
, asoc
, chunk
, GFP_ATOMIC
, &error
,
1982 * If the re-build failed, what is the proper error path
1985 * [We should abort the association. --piggy]
1988 /* FIXME: Several errors are possible. A bad cookie should
1989 * be silently discarded, but think about logging it too.
1992 case -SCTP_IERROR_NOMEM
:
1995 case -SCTP_IERROR_STALE_COOKIE
:
1996 sctp_send_stale_cookie_err(ep
, asoc
, chunk
, commands
,
1998 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
1999 case -SCTP_IERROR_BAD_SIG
:
2001 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2005 /* Compare the tie_tag in cookie with the verification tag of
2006 * current association.
2008 action
= sctp_tietags_compare(new_asoc
, asoc
);
2011 case 'A': /* Association restart. */
2012 retval
= sctp_sf_do_dupcook_a(ep
, asoc
, chunk
, commands
,
2016 case 'B': /* Collision case B. */
2017 retval
= sctp_sf_do_dupcook_b(ep
, asoc
, chunk
, commands
,
2021 case 'C': /* Collision case C. */
2022 retval
= sctp_sf_do_dupcook_c(ep
, asoc
, chunk
, commands
,
2026 case 'D': /* Collision case D. */
2027 retval
= sctp_sf_do_dupcook_d(ep
, asoc
, chunk
, commands
,
2031 default: /* Discard packet for all others. */
2032 retval
= sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2036 /* Delete the tempory new association. */
2037 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(new_asoc
));
2038 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
2043 return SCTP_DISPOSITION_NOMEM
;
2047 * Process an ABORT. (SHUTDOWN-PENDING state)
2049 * See sctp_sf_do_9_1_abort().
2051 sctp_disposition_t
sctp_sf_shutdown_pending_abort(
2052 const struct sctp_endpoint
*ep
,
2053 const struct sctp_association
*asoc
,
2054 const sctp_subtype_t type
,
2056 sctp_cmd_seq_t
*commands
)
2058 struct sctp_chunk
*chunk
= arg
;
2060 if (!sctp_vtag_verify_either(chunk
, asoc
))
2061 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2063 /* Make sure that the ABORT chunk has a valid length.
2064 * Since this is an ABORT chunk, we have to discard it
2065 * because of the following text:
2066 * RFC 2960, Section 3.3.7
2067 * If an endpoint receives an ABORT with a format error or for an
2068 * association that doesn't exist, it MUST silently discard it.
2069 * Because the length is "invalid", we can't really discard just
2070 * as we do not know its true length. So, to be safe, discard the
2073 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_abort_chunk_t
)))
2074 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2076 /* ADD-IP: Special case for ABORT chunks
2077 * F4) One special consideration is that ABORT Chunks arriving
2078 * destined to the IP address being deleted MUST be
2079 * ignored (see Section 5.3.1 for further details).
2081 if (SCTP_ADDR_DEL
==
2082 sctp_bind_addr_state(&asoc
->base
.bind_addr
, &chunk
->dest
))
2083 return sctp_sf_discard_chunk(ep
, asoc
, type
, arg
, commands
);
2085 return __sctp_sf_do_9_1_abort(ep
, asoc
, type
, arg
, commands
);
2089 * Process an ABORT. (SHUTDOWN-SENT state)
2091 * See sctp_sf_do_9_1_abort().
2093 sctp_disposition_t
sctp_sf_shutdown_sent_abort(const struct sctp_endpoint
*ep
,
2094 const struct sctp_association
*asoc
,
2095 const sctp_subtype_t type
,
2097 sctp_cmd_seq_t
*commands
)
2099 struct sctp_chunk
*chunk
= arg
;
2101 if (!sctp_vtag_verify_either(chunk
, asoc
))
2102 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2104 /* Make sure that the ABORT chunk has a valid length.
2105 * Since this is an ABORT chunk, we have to discard it
2106 * because of the following text:
2107 * RFC 2960, Section 3.3.7
2108 * If an endpoint receives an ABORT with a format error or for an
2109 * association that doesn't exist, it MUST silently discard it.
2110 * Because the length is "invalid", we can't really discard just
2111 * as we do not know its true length. So, to be safe, discard the
2114 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_abort_chunk_t
)))
2115 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2117 /* ADD-IP: Special case for ABORT chunks
2118 * F4) One special consideration is that ABORT Chunks arriving
2119 * destined to the IP address being deleted MUST be
2120 * ignored (see Section 5.3.1 for further details).
2122 if (SCTP_ADDR_DEL
==
2123 sctp_bind_addr_state(&asoc
->base
.bind_addr
, &chunk
->dest
))
2124 return sctp_sf_discard_chunk(ep
, asoc
, type
, arg
, commands
);
2126 /* Stop the T2-shutdown timer. */
2127 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
2128 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
2130 /* Stop the T5-shutdown guard timer. */
2131 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
2132 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
2134 return __sctp_sf_do_9_1_abort(ep
, asoc
, type
, arg
, commands
);
2138 * Process an ABORT. (SHUTDOWN-ACK-SENT state)
2140 * See sctp_sf_do_9_1_abort().
2142 sctp_disposition_t
sctp_sf_shutdown_ack_sent_abort(
2143 const struct sctp_endpoint
*ep
,
2144 const struct sctp_association
*asoc
,
2145 const sctp_subtype_t type
,
2147 sctp_cmd_seq_t
*commands
)
2149 /* The same T2 timer, so we should be able to use
2150 * common function with the SHUTDOWN-SENT state.
2152 return sctp_sf_shutdown_sent_abort(ep
, asoc
, type
, arg
, commands
);
2156 * Handle an Error received in COOKIE_ECHOED state.
2158 * Only handle the error type of stale COOKIE Error, the other errors will
2162 * (endpoint, asoc, chunk)
2165 * (asoc, reply_msg, msg_up, timers, counters)
2167 * The return value is the disposition of the chunk.
2169 sctp_disposition_t
sctp_sf_cookie_echoed_err(const struct sctp_endpoint
*ep
,
2170 const struct sctp_association
*asoc
,
2171 const sctp_subtype_t type
,
2173 sctp_cmd_seq_t
*commands
)
2175 struct sctp_chunk
*chunk
= arg
;
2178 if (!sctp_vtag_verify(chunk
, asoc
))
2179 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2181 /* Make sure that the ERROR chunk has a valid length.
2182 * The parameter walking depends on this as well.
2184 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_operr_chunk_t
)))
2185 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2188 /* Process the error here */
2189 /* FUTURE FIXME: When PR-SCTP related and other optional
2190 * parms are emitted, this will have to change to handle multiple
2193 sctp_walk_errors(err
, chunk
->chunk_hdr
) {
2194 if (SCTP_ERROR_STALE_COOKIE
== err
->cause
)
2195 return sctp_sf_do_5_2_6_stale(ep
, asoc
, type
,
2199 /* It is possible to have malformed error causes, and that
2200 * will cause us to end the walk early. However, since
2201 * we are discarding the packet, there should be no adverse
2204 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2208 * Handle a Stale COOKIE Error
2210 * Section: 5.2.6 Handle Stale COOKIE Error
2211 * If the association is in the COOKIE-ECHOED state, the endpoint may elect
2212 * one of the following three alternatives.
2214 * 3) Send a new INIT chunk to the endpoint, adding a Cookie
2215 * Preservative parameter requesting an extension to the lifetime of
2216 * the State Cookie. When calculating the time extension, an
2217 * implementation SHOULD use the RTT information measured based on the
2218 * previous COOKIE ECHO / ERROR exchange, and should add no more
2219 * than 1 second beyond the measured RTT, due to long State Cookie
2220 * lifetimes making the endpoint more subject to a replay attack.
2222 * Verification Tag: Not explicit, but safe to ignore.
2225 * (endpoint, asoc, chunk)
2228 * (asoc, reply_msg, msg_up, timers, counters)
2230 * The return value is the disposition of the chunk.
2232 static sctp_disposition_t
sctp_sf_do_5_2_6_stale(const struct sctp_endpoint
*ep
,
2233 const struct sctp_association
*asoc
,
2234 const sctp_subtype_t type
,
2236 sctp_cmd_seq_t
*commands
)
2238 struct sctp_chunk
*chunk
= arg
;
2240 sctp_cookie_preserve_param_t bht
;
2242 struct sctp_chunk
*reply
;
2243 struct sctp_bind_addr
*bp
;
2244 int attempts
= asoc
->init_err_counter
+ 1;
2246 if (attempts
> asoc
->max_init_attempts
) {
2247 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
2248 SCTP_ERROR(ETIMEDOUT
));
2249 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
2250 SCTP_PERR(SCTP_ERROR_STALE_COOKIE
));
2251 return SCTP_DISPOSITION_DELETE_TCB
;
2254 err
= (sctp_errhdr_t
*)(chunk
->skb
->data
);
2256 /* When calculating the time extension, an implementation
2257 * SHOULD use the RTT information measured based on the
2258 * previous COOKIE ECHO / ERROR exchange, and should add no
2259 * more than 1 second beyond the measured RTT, due to long
2260 * State Cookie lifetimes making the endpoint more subject to
2262 * Measure of Staleness's unit is usec. (1/1000000 sec)
2263 * Suggested Cookie Life-span Increment's unit is msec.
2265 * In general, if you use the suggested cookie life, the value
2266 * found in the field of measure of staleness should be doubled
2267 * to give ample time to retransmit the new cookie and thus
2268 * yield a higher probability of success on the reattempt.
2270 stale
= ntohl(*(__be32
*)((u8
*)err
+ sizeof(sctp_errhdr_t
)));
2271 stale
= (stale
* 2) / 1000;
2273 bht
.param_hdr
.type
= SCTP_PARAM_COOKIE_PRESERVATIVE
;
2274 bht
.param_hdr
.length
= htons(sizeof(bht
));
2275 bht
.lifespan_increment
= htonl(stale
);
2277 /* Build that new INIT chunk. */
2278 bp
= (struct sctp_bind_addr
*) &asoc
->base
.bind_addr
;
2279 reply
= sctp_make_init(asoc
, bp
, GFP_ATOMIC
, sizeof(bht
));
2283 sctp_addto_chunk(reply
, sizeof(bht
), &bht
);
2285 /* Clear peer's init_tag cached in assoc as we are sending a new INIT */
2286 sctp_add_cmd_sf(commands
, SCTP_CMD_CLEAR_INIT_TAG
, SCTP_NULL());
2288 /* Stop pending T3-rtx and heartbeat timers */
2289 sctp_add_cmd_sf(commands
, SCTP_CMD_T3_RTX_TIMERS_STOP
, SCTP_NULL());
2290 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_STOP
, SCTP_NULL());
2292 /* Delete non-primary peer ip addresses since we are transitioning
2293 * back to the COOKIE-WAIT state
2295 sctp_add_cmd_sf(commands
, SCTP_CMD_DEL_NON_PRIMARY
, SCTP_NULL());
2297 /* If we've sent any data bundled with COOKIE-ECHO we will need to
2300 sctp_add_cmd_sf(commands
, SCTP_CMD_T1_RETRAN
,
2301 SCTP_TRANSPORT(asoc
->peer
.primary_path
));
2303 /* Cast away the const modifier, as we want to just
2304 * rerun it through as a sideffect.
2306 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_COUNTER_INC
, SCTP_NULL());
2308 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
2309 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
2310 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
2311 SCTP_STATE(SCTP_STATE_COOKIE_WAIT
));
2312 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
2313 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
2315 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
2317 return SCTP_DISPOSITION_CONSUME
;
2320 return SCTP_DISPOSITION_NOMEM
;
2327 * After checking the Verification Tag, the receiving endpoint shall
2328 * remove the association from its record, and shall report the
2329 * termination to its upper layer.
2331 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
2332 * B) Rules for packet carrying ABORT:
2334 * - The endpoint shall always fill in the Verification Tag field of the
2335 * outbound packet with the destination endpoint's tag value if it
2338 * - If the ABORT is sent in response to an OOTB packet, the endpoint
2339 * MUST follow the procedure described in Section 8.4.
2341 * - The receiver MUST accept the packet if the Verification Tag
2342 * matches either its own tag, OR the tag of its peer. Otherwise, the
2343 * receiver MUST silently discard the packet and take no further
2347 * (endpoint, asoc, chunk)
2350 * (asoc, reply_msg, msg_up, timers, counters)
2352 * The return value is the disposition of the chunk.
2354 sctp_disposition_t
sctp_sf_do_9_1_abort(const struct sctp_endpoint
*ep
,
2355 const struct sctp_association
*asoc
,
2356 const sctp_subtype_t type
,
2358 sctp_cmd_seq_t
*commands
)
2360 struct sctp_chunk
*chunk
= arg
;
2362 if (!sctp_vtag_verify_either(chunk
, asoc
))
2363 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2365 /* Make sure that the ABORT chunk has a valid length.
2366 * Since this is an ABORT chunk, we have to discard it
2367 * because of the following text:
2368 * RFC 2960, Section 3.3.7
2369 * If an endpoint receives an ABORT with a format error or for an
2370 * association that doesn't exist, it MUST silently discard it.
2371 * Because the length is "invalid", we can't really discard just
2372 * as we do not know its true length. So, to be safe, discard the
2375 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_abort_chunk_t
)))
2376 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2378 /* ADD-IP: Special case for ABORT chunks
2379 * F4) One special consideration is that ABORT Chunks arriving
2380 * destined to the IP address being deleted MUST be
2381 * ignored (see Section 5.3.1 for further details).
2383 if (SCTP_ADDR_DEL
==
2384 sctp_bind_addr_state(&asoc
->base
.bind_addr
, &chunk
->dest
))
2385 return sctp_sf_discard_chunk(ep
, asoc
, type
, arg
, commands
);
2387 return __sctp_sf_do_9_1_abort(ep
, asoc
, type
, arg
, commands
);
2390 static sctp_disposition_t
__sctp_sf_do_9_1_abort(const struct sctp_endpoint
*ep
,
2391 const struct sctp_association
*asoc
,
2392 const sctp_subtype_t type
,
2394 sctp_cmd_seq_t
*commands
)
2396 struct sctp_chunk
*chunk
= arg
;
2398 __be16 error
= SCTP_ERROR_NO_ERROR
;
2400 /* See if we have an error cause code in the chunk. */
2401 len
= ntohs(chunk
->chunk_hdr
->length
);
2402 if (len
>= sizeof(struct sctp_chunkhdr
) + sizeof(struct sctp_errhdr
)) {
2405 sctp_walk_errors(err
, chunk
->chunk_hdr
);
2406 if ((void *)err
!= (void *)chunk
->chunk_end
)
2407 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2409 error
= ((sctp_errhdr_t
*)chunk
->skb
->data
)->cause
;
2412 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
, SCTP_ERROR(ECONNRESET
));
2413 /* ASSOC_FAILED will DELETE_TCB. */
2414 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
, SCTP_PERR(error
));
2415 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
2416 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
2418 return SCTP_DISPOSITION_ABORT
;
2422 * Process an ABORT. (COOKIE-WAIT state)
2424 * See sctp_sf_do_9_1_abort() above.
2426 sctp_disposition_t
sctp_sf_cookie_wait_abort(const struct sctp_endpoint
*ep
,
2427 const struct sctp_association
*asoc
,
2428 const sctp_subtype_t type
,
2430 sctp_cmd_seq_t
*commands
)
2432 struct sctp_chunk
*chunk
= arg
;
2434 __be16 error
= SCTP_ERROR_NO_ERROR
;
2436 if (!sctp_vtag_verify_either(chunk
, asoc
))
2437 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2439 /* Make sure that the ABORT chunk has a valid length.
2440 * Since this is an ABORT chunk, we have to discard it
2441 * because of the following text:
2442 * RFC 2960, Section 3.3.7
2443 * If an endpoint receives an ABORT with a format error or for an
2444 * association that doesn't exist, it MUST silently discard it.
2445 * Because the length is "invalid", we can't really discard just
2446 * as we do not know its true length. So, to be safe, discard the
2449 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_abort_chunk_t
)))
2450 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2452 /* See if we have an error cause code in the chunk. */
2453 len
= ntohs(chunk
->chunk_hdr
->length
);
2454 if (len
>= sizeof(struct sctp_chunkhdr
) + sizeof(struct sctp_errhdr
))
2455 error
= ((sctp_errhdr_t
*)chunk
->skb
->data
)->cause
;
2457 return sctp_stop_t1_and_abort(commands
, error
, ECONNREFUSED
, asoc
,
2462 * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state)
2464 sctp_disposition_t
sctp_sf_cookie_wait_icmp_abort(const struct sctp_endpoint
*ep
,
2465 const struct sctp_association
*asoc
,
2466 const sctp_subtype_t type
,
2468 sctp_cmd_seq_t
*commands
)
2470 return sctp_stop_t1_and_abort(commands
, SCTP_ERROR_NO_ERROR
,
2472 (struct sctp_transport
*)arg
);
2476 * Process an ABORT. (COOKIE-ECHOED state)
2478 sctp_disposition_t
sctp_sf_cookie_echoed_abort(const struct sctp_endpoint
*ep
,
2479 const struct sctp_association
*asoc
,
2480 const sctp_subtype_t type
,
2482 sctp_cmd_seq_t
*commands
)
2484 /* There is a single T1 timer, so we should be able to use
2485 * common function with the COOKIE-WAIT state.
2487 return sctp_sf_cookie_wait_abort(ep
, asoc
, type
, arg
, commands
);
2491 * Stop T1 timer and abort association with "INIT failed".
2493 * This is common code called by several sctp_sf_*_abort() functions above.
2495 static sctp_disposition_t
sctp_stop_t1_and_abort(sctp_cmd_seq_t
*commands
,
2496 __be16 error
, int sk_err
,
2497 const struct sctp_association
*asoc
,
2498 struct sctp_transport
*transport
)
2500 SCTP_DEBUG_PRINTK("ABORT received (INIT).\n");
2501 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
2502 SCTP_STATE(SCTP_STATE_CLOSED
));
2503 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
2504 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
2505 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
2506 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
, SCTP_ERROR(sk_err
));
2507 /* CMD_INIT_FAILED will DELETE_TCB. */
2508 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
2510 return SCTP_DISPOSITION_ABORT
;
2514 * sctp_sf_do_9_2_shut
2517 * Upon the reception of the SHUTDOWN, the peer endpoint shall
2518 * - enter the SHUTDOWN-RECEIVED state,
2520 * - stop accepting new data from its SCTP user
2522 * - verify, by checking the Cumulative TSN Ack field of the chunk,
2523 * that all its outstanding DATA chunks have been received by the
2526 * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT
2527 * send a SHUTDOWN in response to a ULP request. And should discard
2528 * subsequent SHUTDOWN chunks.
2530 * If there are still outstanding DATA chunks left, the SHUTDOWN
2531 * receiver shall continue to follow normal data transmission
2532 * procedures defined in Section 6 until all outstanding DATA chunks
2533 * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept
2534 * new data from its SCTP user.
2536 * Verification Tag: 8.5 Verification Tag [Normal verification]
2539 * (endpoint, asoc, chunk)
2542 * (asoc, reply_msg, msg_up, timers, counters)
2544 * The return value is the disposition of the chunk.
2546 sctp_disposition_t
sctp_sf_do_9_2_shutdown(const struct sctp_endpoint
*ep
,
2547 const struct sctp_association
*asoc
,
2548 const sctp_subtype_t type
,
2550 sctp_cmd_seq_t
*commands
)
2552 struct sctp_chunk
*chunk
= arg
;
2553 sctp_shutdownhdr_t
*sdh
;
2554 sctp_disposition_t disposition
;
2555 struct sctp_ulpevent
*ev
;
2558 if (!sctp_vtag_verify(chunk
, asoc
))
2559 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2561 /* Make sure that the SHUTDOWN chunk has a valid length. */
2562 if (!sctp_chunk_length_valid(chunk
,
2563 sizeof(struct sctp_shutdown_chunk_t
)))
2564 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2567 /* Convert the elaborate header. */
2568 sdh
= (sctp_shutdownhdr_t
*)chunk
->skb
->data
;
2569 skb_pull(chunk
->skb
, sizeof(sctp_shutdownhdr_t
));
2570 chunk
->subh
.shutdown_hdr
= sdh
;
2571 ctsn
= ntohl(sdh
->cum_tsn_ack
);
2573 if (TSN_lt(ctsn
, asoc
->ctsn_ack_point
)) {
2574 SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn
);
2575 SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc
->ctsn_ack_point
);
2576 return SCTP_DISPOSITION_DISCARD
;
2579 /* If Cumulative TSN Ack beyond the max tsn currently
2580 * send, terminating the association and respond to the
2581 * sender with an ABORT.
2583 if (!TSN_lt(ctsn
, asoc
->next_tsn
))
2584 return sctp_sf_violation_ctsn(ep
, asoc
, type
, arg
, commands
);
2586 /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT
2587 * When a peer sends a SHUTDOWN, SCTP delivers this notification to
2588 * inform the application that it should cease sending data.
2590 ev
= sctp_ulpevent_make_shutdown_event(asoc
, 0, GFP_ATOMIC
);
2592 disposition
= SCTP_DISPOSITION_NOMEM
;
2595 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
2597 /* Upon the reception of the SHUTDOWN, the peer endpoint shall
2598 * - enter the SHUTDOWN-RECEIVED state,
2599 * - stop accepting new data from its SCTP user
2601 * [This is implicit in the new state.]
2603 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
2604 SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED
));
2605 disposition
= SCTP_DISPOSITION_CONSUME
;
2607 if (sctp_outq_is_empty(&asoc
->outqueue
)) {
2608 disposition
= sctp_sf_do_9_2_shutdown_ack(ep
, asoc
, type
,
2612 if (SCTP_DISPOSITION_NOMEM
== disposition
)
2615 /* - verify, by checking the Cumulative TSN Ack field of the
2616 * chunk, that all its outstanding DATA chunks have been
2617 * received by the SHUTDOWN sender.
2619 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_CTSN
,
2620 SCTP_BE32(chunk
->subh
.shutdown_hdr
->cum_tsn_ack
));
2627 * sctp_sf_do_9_2_shut_ctsn
2629 * Once an endpoint has reached the SHUTDOWN-RECEIVED state,
2630 * it MUST NOT send a SHUTDOWN in response to a ULP request.
2631 * The Cumulative TSN Ack of the received SHUTDOWN chunk
2632 * MUST be processed.
2634 sctp_disposition_t
sctp_sf_do_9_2_shut_ctsn(const struct sctp_endpoint
*ep
,
2635 const struct sctp_association
*asoc
,
2636 const sctp_subtype_t type
,
2638 sctp_cmd_seq_t
*commands
)
2640 struct sctp_chunk
*chunk
= arg
;
2641 sctp_shutdownhdr_t
*sdh
;
2644 if (!sctp_vtag_verify(chunk
, asoc
))
2645 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2647 /* Make sure that the SHUTDOWN chunk has a valid length. */
2648 if (!sctp_chunk_length_valid(chunk
,
2649 sizeof(struct sctp_shutdown_chunk_t
)))
2650 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2653 sdh
= (sctp_shutdownhdr_t
*)chunk
->skb
->data
;
2654 ctsn
= ntohl(sdh
->cum_tsn_ack
);
2656 if (TSN_lt(ctsn
, asoc
->ctsn_ack_point
)) {
2657 SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn
);
2658 SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc
->ctsn_ack_point
);
2659 return SCTP_DISPOSITION_DISCARD
;
2662 /* If Cumulative TSN Ack beyond the max tsn currently
2663 * send, terminating the association and respond to the
2664 * sender with an ABORT.
2666 if (!TSN_lt(ctsn
, asoc
->next_tsn
))
2667 return sctp_sf_violation_ctsn(ep
, asoc
, type
, arg
, commands
);
2669 /* verify, by checking the Cumulative TSN Ack field of the
2670 * chunk, that all its outstanding DATA chunks have been
2671 * received by the SHUTDOWN sender.
2673 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_CTSN
,
2674 SCTP_BE32(sdh
->cum_tsn_ack
));
2676 return SCTP_DISPOSITION_CONSUME
;
2680 * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk
2681 * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination
2682 * transport addresses (either in the IP addresses or in the INIT chunk)
2683 * that belong to this association, it should discard the INIT chunk and
2684 * retransmit the SHUTDOWN ACK chunk.
2686 sctp_disposition_t
sctp_sf_do_9_2_reshutack(const struct sctp_endpoint
*ep
,
2687 const struct sctp_association
*asoc
,
2688 const sctp_subtype_t type
,
2690 sctp_cmd_seq_t
*commands
)
2692 struct sctp_chunk
*chunk
= (struct sctp_chunk
*) arg
;
2693 struct sctp_chunk
*reply
;
2695 /* Make sure that the chunk has a valid length */
2696 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
2697 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2700 /* Since we are not going to really process this INIT, there
2701 * is no point in verifying chunk boundries. Just generate
2704 reply
= sctp_make_shutdown_ack(asoc
, chunk
);
2708 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
2709 * the T2-SHUTDOWN timer.
2711 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T2
, SCTP_CHUNK(reply
));
2713 /* and restart the T2-shutdown timer. */
2714 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
2715 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
2717 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
2719 return SCTP_DISPOSITION_CONSUME
;
2721 return SCTP_DISPOSITION_NOMEM
;
2725 * sctp_sf_do_ecn_cwr
2727 * Section: Appendix A: Explicit Congestion Notification
2731 * RFC 2481 details a specific bit for a sender to send in the header of
2732 * its next outbound TCP segment to indicate to its peer that it has
2733 * reduced its congestion window. This is termed the CWR bit. For
2734 * SCTP the same indication is made by including the CWR chunk.
2735 * This chunk contains one data element, i.e. the TSN number that
2736 * was sent in the ECNE chunk. This element represents the lowest
2737 * TSN number in the datagram that was originally marked with the
2740 * Verification Tag: 8.5 Verification Tag [Normal verification]
2742 * (endpoint, asoc, chunk)
2745 * (asoc, reply_msg, msg_up, timers, counters)
2747 * The return value is the disposition of the chunk.
2749 sctp_disposition_t
sctp_sf_do_ecn_cwr(const struct sctp_endpoint
*ep
,
2750 const struct sctp_association
*asoc
,
2751 const sctp_subtype_t type
,
2753 sctp_cmd_seq_t
*commands
)
2756 struct sctp_chunk
*chunk
= arg
;
2759 if (!sctp_vtag_verify(chunk
, asoc
))
2760 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2762 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_ecne_chunk_t
)))
2763 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2766 cwr
= (sctp_cwrhdr_t
*) chunk
->skb
->data
;
2767 skb_pull(chunk
->skb
, sizeof(sctp_cwrhdr_t
));
2769 lowest_tsn
= ntohl(cwr
->lowest_tsn
);
2771 /* Does this CWR ack the last sent congestion notification? */
2772 if (TSN_lte(asoc
->last_ecne_tsn
, lowest_tsn
)) {
2773 /* Stop sending ECNE. */
2774 sctp_add_cmd_sf(commands
,
2776 SCTP_U32(lowest_tsn
));
2778 return SCTP_DISPOSITION_CONSUME
;
2784 * Section: Appendix A: Explicit Congestion Notification
2788 * RFC 2481 details a specific bit for a receiver to send back in its
2789 * TCP acknowledgements to notify the sender of the Congestion
2790 * Experienced (CE) bit having arrived from the network. For SCTP this
2791 * same indication is made by including the ECNE chunk. This chunk
2792 * contains one data element, i.e. the lowest TSN associated with the IP
2793 * datagram marked with the CE bit.....
2795 * Verification Tag: 8.5 Verification Tag [Normal verification]
2797 * (endpoint, asoc, chunk)
2800 * (asoc, reply_msg, msg_up, timers, counters)
2802 * The return value is the disposition of the chunk.
2804 sctp_disposition_t
sctp_sf_do_ecne(const struct sctp_endpoint
*ep
,
2805 const struct sctp_association
*asoc
,
2806 const sctp_subtype_t type
,
2808 sctp_cmd_seq_t
*commands
)
2810 sctp_ecnehdr_t
*ecne
;
2811 struct sctp_chunk
*chunk
= arg
;
2813 if (!sctp_vtag_verify(chunk
, asoc
))
2814 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2816 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_ecne_chunk_t
)))
2817 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2820 ecne
= (sctp_ecnehdr_t
*) chunk
->skb
->data
;
2821 skb_pull(chunk
->skb
, sizeof(sctp_ecnehdr_t
));
2823 /* If this is a newer ECNE than the last CWR packet we sent out */
2824 sctp_add_cmd_sf(commands
, SCTP_CMD_ECN_ECNE
,
2825 SCTP_U32(ntohl(ecne
->lowest_tsn
)));
2827 return SCTP_DISPOSITION_CONSUME
;
2831 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
2833 * The SCTP endpoint MUST always acknowledge the reception of each valid
2836 * The guidelines on delayed acknowledgement algorithm specified in
2837 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
2838 * acknowledgement SHOULD be generated for at least every second packet
2839 * (not every second DATA chunk) received, and SHOULD be generated within
2840 * 200 ms of the arrival of any unacknowledged DATA chunk. In some
2841 * situations it may be beneficial for an SCTP transmitter to be more
2842 * conservative than the algorithms detailed in this document allow.
2843 * However, an SCTP transmitter MUST NOT be more aggressive than the
2844 * following algorithms allow.
2846 * A SCTP receiver MUST NOT generate more than one SACK for every
2847 * incoming packet, other than to update the offered window as the
2848 * receiving application consumes new data.
2850 * Verification Tag: 8.5 Verification Tag [Normal verification]
2853 * (endpoint, asoc, chunk)
2856 * (asoc, reply_msg, msg_up, timers, counters)
2858 * The return value is the disposition of the chunk.
2860 sctp_disposition_t
sctp_sf_eat_data_6_2(const struct sctp_endpoint
*ep
,
2861 const struct sctp_association
*asoc
,
2862 const sctp_subtype_t type
,
2864 sctp_cmd_seq_t
*commands
)
2866 struct sctp_chunk
*chunk
= arg
;
2867 sctp_arg_t force
= SCTP_NOFORCE();
2870 if (!sctp_vtag_verify(chunk
, asoc
)) {
2871 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
2873 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2876 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_data_chunk_t
)))
2877 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2880 error
= sctp_eat_data(asoc
, chunk
, commands
);
2882 case SCTP_IERROR_NO_ERROR
:
2884 case SCTP_IERROR_HIGH_TSN
:
2885 case SCTP_IERROR_BAD_STREAM
:
2886 SCTP_INC_STATS(SCTP_MIB_IN_DATA_CHUNK_DISCARDS
);
2887 goto discard_noforce
;
2888 case SCTP_IERROR_DUP_TSN
:
2889 case SCTP_IERROR_IGNORE_TSN
:
2890 SCTP_INC_STATS(SCTP_MIB_IN_DATA_CHUNK_DISCARDS
);
2892 case SCTP_IERROR_NO_DATA
:
2894 case SCTP_IERROR_PROTO_VIOLATION
:
2895 return sctp_sf_abort_violation(ep
, asoc
, chunk
, commands
,
2896 (u8
*)chunk
->subh
.data_hdr
, sizeof(sctp_datahdr_t
));
2901 if (chunk
->chunk_hdr
->flags
& SCTP_DATA_SACK_IMM
)
2902 force
= SCTP_FORCE();
2904 if (asoc
->autoclose
) {
2905 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
2906 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
2909 /* If this is the last chunk in a packet, we need to count it
2910 * toward sack generation. Note that we need to SACK every
2911 * OTHER packet containing data chunks, EVEN IF WE DISCARD
2912 * THEM. We elect to NOT generate SACK's if the chunk fails
2913 * the verification tag test.
2915 * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2917 * The SCTP endpoint MUST always acknowledge the reception of
2918 * each valid DATA chunk.
2920 * The guidelines on delayed acknowledgement algorithm
2921 * specified in Section 4.2 of [RFC2581] SHOULD be followed.
2922 * Specifically, an acknowledgement SHOULD be generated for at
2923 * least every second packet (not every second DATA chunk)
2924 * received, and SHOULD be generated within 200 ms of the
2925 * arrival of any unacknowledged DATA chunk. In some
2926 * situations it may be beneficial for an SCTP transmitter to
2927 * be more conservative than the algorithms detailed in this
2928 * document allow. However, an SCTP transmitter MUST NOT be
2929 * more aggressive than the following algorithms allow.
2931 if (chunk
->end_of_packet
)
2932 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, force
);
2934 return SCTP_DISPOSITION_CONSUME
;
2937 /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2939 * When a packet arrives with duplicate DATA chunk(s) and with
2940 * no new DATA chunk(s), the endpoint MUST immediately send a
2941 * SACK with no delay. If a packet arrives with duplicate
2942 * DATA chunk(s) bundled with new DATA chunks, the endpoint
2943 * MAY immediately send a SACK. Normally receipt of duplicate
2944 * DATA chunks will occur when the original SACK chunk was lost
2945 * and the peer's RTO has expired. The duplicate TSN number(s)
2946 * SHOULD be reported in the SACK as duplicate.
2948 /* In our case, we split the MAY SACK advice up whether or not
2949 * the last chunk is a duplicate.'
2951 if (chunk
->end_of_packet
)
2952 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_FORCE());
2953 return SCTP_DISPOSITION_DISCARD
;
2956 if (chunk
->end_of_packet
)
2957 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, force
);
2959 return SCTP_DISPOSITION_DISCARD
;
2961 return SCTP_DISPOSITION_CONSUME
;
2966 * sctp_sf_eat_data_fast_4_4
2969 * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received
2970 * DATA chunks without delay.
2972 * Verification Tag: 8.5 Verification Tag [Normal verification]
2974 * (endpoint, asoc, chunk)
2977 * (asoc, reply_msg, msg_up, timers, counters)
2979 * The return value is the disposition of the chunk.
2981 sctp_disposition_t
sctp_sf_eat_data_fast_4_4(const struct sctp_endpoint
*ep
,
2982 const struct sctp_association
*asoc
,
2983 const sctp_subtype_t type
,
2985 sctp_cmd_seq_t
*commands
)
2987 struct sctp_chunk
*chunk
= arg
;
2990 if (!sctp_vtag_verify(chunk
, asoc
)) {
2991 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
2993 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2996 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_data_chunk_t
)))
2997 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3000 error
= sctp_eat_data(asoc
, chunk
, commands
);
3002 case SCTP_IERROR_NO_ERROR
:
3003 case SCTP_IERROR_HIGH_TSN
:
3004 case SCTP_IERROR_DUP_TSN
:
3005 case SCTP_IERROR_IGNORE_TSN
:
3006 case SCTP_IERROR_BAD_STREAM
:
3008 case SCTP_IERROR_NO_DATA
:
3010 case SCTP_IERROR_PROTO_VIOLATION
:
3011 return sctp_sf_abort_violation(ep
, asoc
, chunk
, commands
,
3012 (u8
*)chunk
->subh
.data_hdr
, sizeof(sctp_datahdr_t
));
3017 /* Go a head and force a SACK, since we are shutting down. */
3019 /* Implementor's Guide.
3021 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3022 * respond to each received packet containing one or more DATA chunk(s)
3023 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3025 if (chunk
->end_of_packet
) {
3026 /* We must delay the chunk creation since the cumulative
3027 * TSN has not been updated yet.
3029 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SHUTDOWN
, SCTP_NULL());
3030 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_FORCE());
3031 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
3032 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
3036 return SCTP_DISPOSITION_CONSUME
;
3040 * Section: 6.2 Processing a Received SACK
3041 * D) Any time a SACK arrives, the endpoint performs the following:
3043 * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point,
3044 * then drop the SACK. Since Cumulative TSN Ack is monotonically
3045 * increasing, a SACK whose Cumulative TSN Ack is less than the
3046 * Cumulative TSN Ack Point indicates an out-of-order SACK.
3048 * ii) Set rwnd equal to the newly received a_rwnd minus the number
3049 * of bytes still outstanding after processing the Cumulative TSN Ack
3050 * and the Gap Ack Blocks.
3052 * iii) If the SACK is missing a TSN that was previously
3053 * acknowledged via a Gap Ack Block (e.g., the data receiver
3054 * reneged on the data), then mark the corresponding DATA chunk
3055 * as available for retransmit: Mark it as missing for fast
3056 * retransmit as described in Section 7.2.4 and if no retransmit
3057 * timer is running for the destination address to which the DATA
3058 * chunk was originally transmitted, then T3-rtx is started for
3059 * that destination address.
3061 * Verification Tag: 8.5 Verification Tag [Normal verification]
3064 * (endpoint, asoc, chunk)
3067 * (asoc, reply_msg, msg_up, timers, counters)
3069 * The return value is the disposition of the chunk.
3071 sctp_disposition_t
sctp_sf_eat_sack_6_2(const struct sctp_endpoint
*ep
,
3072 const struct sctp_association
*asoc
,
3073 const sctp_subtype_t type
,
3075 sctp_cmd_seq_t
*commands
)
3077 struct sctp_chunk
*chunk
= arg
;
3078 sctp_sackhdr_t
*sackh
;
3081 if (!sctp_vtag_verify(chunk
, asoc
))
3082 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3084 /* Make sure that the SACK chunk has a valid length. */
3085 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_sack_chunk_t
)))
3086 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3089 /* Pull the SACK chunk from the data buffer */
3090 sackh
= sctp_sm_pull_sack(chunk
);
3091 /* Was this a bogus SACK? */
3093 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3094 chunk
->subh
.sack_hdr
= sackh
;
3095 ctsn
= ntohl(sackh
->cum_tsn_ack
);
3097 /* i) If Cumulative TSN Ack is less than the Cumulative TSN
3098 * Ack Point, then drop the SACK. Since Cumulative TSN
3099 * Ack is monotonically increasing, a SACK whose
3100 * Cumulative TSN Ack is less than the Cumulative TSN Ack
3101 * Point indicates an out-of-order SACK.
3103 if (TSN_lt(ctsn
, asoc
->ctsn_ack_point
)) {
3104 SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn
);
3105 SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc
->ctsn_ack_point
);
3106 return SCTP_DISPOSITION_DISCARD
;
3109 /* If Cumulative TSN Ack beyond the max tsn currently
3110 * send, terminating the association and respond to the
3111 * sender with an ABORT.
3113 if (!TSN_lt(ctsn
, asoc
->next_tsn
))
3114 return sctp_sf_violation_ctsn(ep
, asoc
, type
, arg
, commands
);
3116 /* Return this SACK for further processing. */
3117 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_SACK
, SCTP_SACKH(sackh
));
3119 /* Note: We do the rest of the work on the PROCESS_SACK
3122 return SCTP_DISPOSITION_CONSUME
;
3126 * Generate an ABORT in response to a packet.
3128 * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41
3130 * 8) The receiver should respond to the sender of the OOTB packet with
3131 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3132 * MUST fill in the Verification Tag field of the outbound packet
3133 * with the value found in the Verification Tag field of the OOTB
3134 * packet and set the T-bit in the Chunk Flags to indicate that the
3135 * Verification Tag is reflected. After sending this ABORT, the
3136 * receiver of the OOTB packet shall discard the OOTB packet and take
3137 * no further action.
3141 * The return value is the disposition of the chunk.
3143 static sctp_disposition_t
sctp_sf_tabort_8_4_8(const struct sctp_endpoint
*ep
,
3144 const struct sctp_association
*asoc
,
3145 const sctp_subtype_t type
,
3147 sctp_cmd_seq_t
*commands
)
3149 struct sctp_packet
*packet
= NULL
;
3150 struct sctp_chunk
*chunk
= arg
;
3151 struct sctp_chunk
*abort
;
3153 packet
= sctp_ootb_pkt_new(asoc
, chunk
);
3156 /* Make an ABORT. The T bit will be set if the asoc
3159 abort
= sctp_make_abort(asoc
, chunk
, 0);
3161 sctp_ootb_pkt_free(packet
);
3162 return SCTP_DISPOSITION_NOMEM
;
3165 /* Reflect vtag if T-Bit is set */
3166 if (sctp_test_T_bit(abort
))
3167 packet
->vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
3169 /* Set the skb to the belonging sock for accounting. */
3170 abort
->skb
->sk
= ep
->base
.sk
;
3172 sctp_packet_append_chunk(packet
, abort
);
3174 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
3175 SCTP_PACKET(packet
));
3177 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
3179 sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3180 return SCTP_DISPOSITION_CONSUME
;
3183 return SCTP_DISPOSITION_NOMEM
;
3187 * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR
3188 * event as ULP notification for each cause included in the chunk.
3190 * API 5.3.1.3 - SCTP_REMOTE_ERROR
3192 * The return value is the disposition of the chunk.
3194 sctp_disposition_t
sctp_sf_operr_notify(const struct sctp_endpoint
*ep
,
3195 const struct sctp_association
*asoc
,
3196 const sctp_subtype_t type
,
3198 sctp_cmd_seq_t
*commands
)
3200 struct sctp_chunk
*chunk
= arg
;
3203 if (!sctp_vtag_verify(chunk
, asoc
))
3204 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3206 /* Make sure that the ERROR chunk has a valid length. */
3207 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_operr_chunk_t
)))
3208 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3210 sctp_walk_errors(err
, chunk
->chunk_hdr
);
3211 if ((void *)err
!= (void *)chunk
->chunk_end
)
3212 return sctp_sf_violation_paramlen(ep
, asoc
, type
, arg
,
3213 (void *)err
, commands
);
3215 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_OPERR
,
3218 return SCTP_DISPOSITION_CONSUME
;
3222 * Process an inbound SHUTDOWN ACK.
3225 * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3226 * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its
3227 * peer, and remove all record of the association.
3229 * The return value is the disposition.
3231 sctp_disposition_t
sctp_sf_do_9_2_final(const struct sctp_endpoint
*ep
,
3232 const struct sctp_association
*asoc
,
3233 const sctp_subtype_t type
,
3235 sctp_cmd_seq_t
*commands
)
3237 struct sctp_chunk
*chunk
= arg
;
3238 struct sctp_chunk
*reply
;
3239 struct sctp_ulpevent
*ev
;
3241 if (!sctp_vtag_verify(chunk
, asoc
))
3242 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3244 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3245 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
3246 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3248 /* 10.2 H) SHUTDOWN COMPLETE notification
3250 * When SCTP completes the shutdown procedures (section 9.2) this
3251 * notification is passed to the upper layer.
3253 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_SHUTDOWN_COMP
,
3254 0, 0, 0, NULL
, GFP_ATOMIC
);
3258 /* ...send a SHUTDOWN COMPLETE chunk to its peer, */
3259 reply
= sctp_make_shutdown_complete(asoc
, chunk
);
3263 /* Do all the commands now (after allocation), so that we
3264 * have consistent state if memory allocation failes
3266 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
3268 /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3269 * stop the T2-shutdown timer,
3271 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3272 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
3274 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3275 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
3277 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
3278 SCTP_STATE(SCTP_STATE_CLOSED
));
3279 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS
);
3280 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
3281 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
3283 /* ...and remove all record of the association. */
3284 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
3285 return SCTP_DISPOSITION_DELETE_TCB
;
3288 sctp_ulpevent_free(ev
);
3290 return SCTP_DISPOSITION_NOMEM
;
3294 * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41.
3296 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3297 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3298 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3299 * packet must fill in the Verification Tag field of the outbound
3300 * packet with the Verification Tag received in the SHUTDOWN ACK and
3301 * set the T-bit in the Chunk Flags to indicate that the Verification
3304 * 8) The receiver should respond to the sender of the OOTB packet with
3305 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3306 * MUST fill in the Verification Tag field of the outbound packet
3307 * with the value found in the Verification Tag field of the OOTB
3308 * packet and set the T-bit in the Chunk Flags to indicate that the
3309 * Verification Tag is reflected. After sending this ABORT, the
3310 * receiver of the OOTB packet shall discard the OOTB packet and take
3311 * no further action.
3313 sctp_disposition_t
sctp_sf_ootb(const struct sctp_endpoint
*ep
,
3314 const struct sctp_association
*asoc
,
3315 const sctp_subtype_t type
,
3317 sctp_cmd_seq_t
*commands
)
3319 struct sctp_chunk
*chunk
= arg
;
3320 struct sk_buff
*skb
= chunk
->skb
;
3321 sctp_chunkhdr_t
*ch
;
3324 int ootb_shut_ack
= 0;
3325 int ootb_cookie_ack
= 0;
3327 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES
);
3329 ch
= (sctp_chunkhdr_t
*) chunk
->chunk_hdr
;
3331 /* Report violation if the chunk is less then minimal */
3332 if (ntohs(ch
->length
) < sizeof(sctp_chunkhdr_t
))
3333 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3336 /* Now that we know we at least have a chunk header,
3337 * do things that are type appropriate.
3339 if (SCTP_CID_SHUTDOWN_ACK
== ch
->type
)
3342 /* RFC 2960, Section 3.3.7
3343 * Moreover, under any circumstances, an endpoint that
3344 * receives an ABORT MUST NOT respond to that ABORT by
3345 * sending an ABORT of its own.
3347 if (SCTP_CID_ABORT
== ch
->type
)
3348 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3350 /* RFC 8.4, 7) If the packet contains a "Stale cookie" ERROR
3351 * or a COOKIE ACK the SCTP Packet should be silently
3355 if (SCTP_CID_COOKIE_ACK
== ch
->type
)
3356 ootb_cookie_ack
= 1;
3358 if (SCTP_CID_ERROR
== ch
->type
) {
3359 sctp_walk_errors(err
, ch
) {
3360 if (SCTP_ERROR_STALE_COOKIE
== err
->cause
) {
3361 ootb_cookie_ack
= 1;
3367 /* Report violation if chunk len overflows */
3368 ch_end
= ((__u8
*)ch
) + WORD_ROUND(ntohs(ch
->length
));
3369 if (ch_end
> skb_tail_pointer(skb
))
3370 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3373 ch
= (sctp_chunkhdr_t
*) ch_end
;
3374 } while (ch_end
< skb_tail_pointer(skb
));
3377 return sctp_sf_shut_8_4_5(ep
, asoc
, type
, arg
, commands
);
3378 else if (ootb_cookie_ack
)
3379 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3381 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
, commands
);
3385 * Handle an "Out of the blue" SHUTDOWN ACK.
3387 * Section: 8.4 5, sctpimpguide 2.41.
3389 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3390 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3391 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3392 * packet must fill in the Verification Tag field of the outbound
3393 * packet with the Verification Tag received in the SHUTDOWN ACK and
3394 * set the T-bit in the Chunk Flags to indicate that the Verification
3398 * (endpoint, asoc, type, arg, commands)
3401 * (sctp_disposition_t)
3403 * The return value is the disposition of the chunk.
3405 static sctp_disposition_t
sctp_sf_shut_8_4_5(const struct sctp_endpoint
*ep
,
3406 const struct sctp_association
*asoc
,
3407 const sctp_subtype_t type
,
3409 sctp_cmd_seq_t
*commands
)
3411 struct sctp_packet
*packet
= NULL
;
3412 struct sctp_chunk
*chunk
= arg
;
3413 struct sctp_chunk
*shut
;
3415 packet
= sctp_ootb_pkt_new(asoc
, chunk
);
3418 /* Make an SHUTDOWN_COMPLETE.
3419 * The T bit will be set if the asoc is NULL.
3421 shut
= sctp_make_shutdown_complete(asoc
, chunk
);
3423 sctp_ootb_pkt_free(packet
);
3424 return SCTP_DISPOSITION_NOMEM
;
3427 /* Reflect vtag if T-Bit is set */
3428 if (sctp_test_T_bit(shut
))
3429 packet
->vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
3431 /* Set the skb to the belonging sock for accounting. */
3432 shut
->skb
->sk
= ep
->base
.sk
;
3434 sctp_packet_append_chunk(packet
, shut
);
3436 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
3437 SCTP_PACKET(packet
));
3439 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
3441 /* If the chunk length is invalid, we don't want to process
3442 * the reset of the packet.
3444 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
3445 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3447 /* We need to discard the rest of the packet to prevent
3448 * potential bomming attacks from additional bundled chunks.
3449 * This is documented in SCTP Threats ID.
3451 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3454 return SCTP_DISPOSITION_NOMEM
;
3458 * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state.
3460 * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK
3461 * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the
3462 * procedures in section 8.4 SHOULD be followed, in other words it
3463 * should be treated as an Out Of The Blue packet.
3464 * [This means that we do NOT check the Verification Tag on these
3468 sctp_disposition_t
sctp_sf_do_8_5_1_E_sa(const struct sctp_endpoint
*ep
,
3469 const struct sctp_association
*asoc
,
3470 const sctp_subtype_t type
,
3472 sctp_cmd_seq_t
*commands
)
3474 struct sctp_chunk
*chunk
= arg
;
3476 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3477 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
3478 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3481 /* Although we do have an association in this case, it corresponds
3482 * to a restarted association. So the packet is treated as an OOTB
3483 * packet and the state function that handles OOTB SHUTDOWN_ACK is
3484 * called with a NULL association.
3486 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES
);
3488 return sctp_sf_shut_8_4_5(ep
, NULL
, type
, arg
, commands
);
3491 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */
3492 sctp_disposition_t
sctp_sf_do_asconf(const struct sctp_endpoint
*ep
,
3493 const struct sctp_association
*asoc
,
3494 const sctp_subtype_t type
, void *arg
,
3495 sctp_cmd_seq_t
*commands
)
3497 struct sctp_chunk
*chunk
= arg
;
3498 struct sctp_chunk
*asconf_ack
= NULL
;
3499 struct sctp_paramhdr
*err_param
= NULL
;
3500 sctp_addiphdr_t
*hdr
;
3501 union sctp_addr_param
*addr_param
;
3505 if (!sctp_vtag_verify(chunk
, asoc
)) {
3506 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3508 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3511 /* ADD-IP: Section 4.1.1
3512 * This chunk MUST be sent in an authenticated way by using
3513 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3514 * is received unauthenticated it MUST be silently discarded as
3515 * described in [I-D.ietf-tsvwg-sctp-auth].
3517 if (!sctp_addip_noauth
&& !chunk
->auth
)
3518 return sctp_sf_discard_chunk(ep
, asoc
, type
, arg
, commands
);
3520 /* Make sure that the ASCONF ADDIP chunk has a valid length. */
3521 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_addip_chunk_t
)))
3522 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3525 hdr
= (sctp_addiphdr_t
*)chunk
->skb
->data
;
3526 serial
= ntohl(hdr
->serial
);
3528 addr_param
= (union sctp_addr_param
*)hdr
->params
;
3529 length
= ntohs(addr_param
->p
.length
);
3530 if (length
< sizeof(sctp_paramhdr_t
))
3531 return sctp_sf_violation_paramlen(ep
, asoc
, type
, arg
,
3532 (void *)addr_param
, commands
);
3534 /* Verify the ASCONF chunk before processing it. */
3535 if (!sctp_verify_asconf(asoc
,
3536 (sctp_paramhdr_t
*)((void *)addr_param
+ length
),
3537 (void *)chunk
->chunk_end
,
3539 return sctp_sf_violation_paramlen(ep
, asoc
, type
, arg
,
3540 (void *)err_param
, commands
);
3542 /* ADDIP 5.2 E1) Compare the value of the serial number to the value
3543 * the endpoint stored in a new association variable
3544 * 'Peer-Serial-Number'.
3546 if (serial
== asoc
->peer
.addip_serial
+ 1) {
3547 /* If this is the first instance of ASCONF in the packet,
3548 * we can clean our old ASCONF-ACKs.
3550 if (!chunk
->has_asconf
)
3551 sctp_assoc_clean_asconf_ack_cache(asoc
);
3553 /* ADDIP 5.2 E4) When the Sequence Number matches the next one
3554 * expected, process the ASCONF as described below and after
3555 * processing the ASCONF Chunk, append an ASCONF-ACK Chunk to
3556 * the response packet and cache a copy of it (in the event it
3557 * later needs to be retransmitted).
3559 * Essentially, do V1-V5.
3561 asconf_ack
= sctp_process_asconf((struct sctp_association
*)
3564 return SCTP_DISPOSITION_NOMEM
;
3565 } else if (serial
< asoc
->peer
.addip_serial
+ 1) {
3567 * If the value found in the Sequence Number is less than the
3568 * ('Peer- Sequence-Number' + 1), simply skip to the next
3569 * ASCONF, and include in the outbound response packet
3570 * any previously cached ASCONF-ACK response that was
3571 * sent and saved that matches the Sequence Number of the
3572 * ASCONF. Note: It is possible that no cached ASCONF-ACK
3573 * Chunk exists. This will occur when an older ASCONF
3574 * arrives out of order. In such a case, the receiver
3575 * should skip the ASCONF Chunk and not include ASCONF-ACK
3576 * Chunk for that chunk.
3578 asconf_ack
= sctp_assoc_lookup_asconf_ack(asoc
, hdr
->serial
);
3580 return SCTP_DISPOSITION_DISCARD
;
3582 /* Reset the transport so that we select the correct one
3583 * this time around. This is to make sure that we don't
3584 * accidentally use a stale transport that's been removed.
3586 asconf_ack
->transport
= NULL
;
3588 /* ADDIP 5.2 E5) Otherwise, the ASCONF Chunk is discarded since
3589 * it must be either a stale packet or from an attacker.
3591 return SCTP_DISPOSITION_DISCARD
;
3594 /* ADDIP 5.2 E6) The destination address of the SCTP packet
3595 * containing the ASCONF-ACK Chunks MUST be the source address of
3596 * the SCTP packet that held the ASCONF Chunks.
3598 * To do this properly, we'll set the destination address of the chunk
3599 * and at the transmit time, will try look up the transport to use.
3600 * Since ASCONFs may be bundled, the correct transport may not be
3601 * created until we process the entire packet, thus this workaround.
3603 asconf_ack
->dest
= chunk
->source
;
3604 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(asconf_ack
));
3606 return SCTP_DISPOSITION_CONSUME
;
3610 * ADDIP Section 4.3 General rules for address manipulation
3611 * When building TLV parameters for the ASCONF Chunk that will add or
3612 * delete IP addresses the D0 to D13 rules should be applied:
3614 sctp_disposition_t
sctp_sf_do_asconf_ack(const struct sctp_endpoint
*ep
,
3615 const struct sctp_association
*asoc
,
3616 const sctp_subtype_t type
, void *arg
,
3617 sctp_cmd_seq_t
*commands
)
3619 struct sctp_chunk
*asconf_ack
= arg
;
3620 struct sctp_chunk
*last_asconf
= asoc
->addip_last_asconf
;
3621 struct sctp_chunk
*abort
;
3622 struct sctp_paramhdr
*err_param
= NULL
;
3623 sctp_addiphdr_t
*addip_hdr
;
3624 __u32 sent_serial
, rcvd_serial
;
3626 if (!sctp_vtag_verify(asconf_ack
, asoc
)) {
3627 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3629 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3632 /* ADD-IP, Section 4.1.2:
3633 * This chunk MUST be sent in an authenticated way by using
3634 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3635 * is received unauthenticated it MUST be silently discarded as
3636 * described in [I-D.ietf-tsvwg-sctp-auth].
3638 if (!sctp_addip_noauth
&& !asconf_ack
->auth
)
3639 return sctp_sf_discard_chunk(ep
, asoc
, type
, arg
, commands
);
3641 /* Make sure that the ADDIP chunk has a valid length. */
3642 if (!sctp_chunk_length_valid(asconf_ack
, sizeof(sctp_addip_chunk_t
)))
3643 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3646 addip_hdr
= (sctp_addiphdr_t
*)asconf_ack
->skb
->data
;
3647 rcvd_serial
= ntohl(addip_hdr
->serial
);
3649 /* Verify the ASCONF-ACK chunk before processing it. */
3650 if (!sctp_verify_asconf(asoc
,
3651 (sctp_paramhdr_t
*)addip_hdr
->params
,
3652 (void *)asconf_ack
->chunk_end
,
3654 return sctp_sf_violation_paramlen(ep
, asoc
, type
, arg
,
3655 (void *)err_param
, commands
);
3658 addip_hdr
= (sctp_addiphdr_t
*)last_asconf
->subh
.addip_hdr
;
3659 sent_serial
= ntohl(addip_hdr
->serial
);
3661 sent_serial
= asoc
->addip_serial
- 1;
3664 /* D0) If an endpoint receives an ASCONF-ACK that is greater than or
3665 * equal to the next serial number to be used but no ASCONF chunk is
3666 * outstanding the endpoint MUST ABORT the association. Note that a
3667 * sequence number is greater than if it is no more than 2^^31-1
3668 * larger than the current sequence number (using serial arithmetic).
3670 if (ADDIP_SERIAL_gte(rcvd_serial
, sent_serial
+ 1) &&
3671 !(asoc
->addip_last_asconf
)) {
3672 abort
= sctp_make_abort(asoc
, asconf_ack
,
3673 sizeof(sctp_errhdr_t
));
3675 sctp_init_cause(abort
, SCTP_ERROR_ASCONF_ACK
, 0);
3676 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
3679 /* We are going to ABORT, so we might as well stop
3680 * processing the rest of the chunks in the packet.
3682 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3683 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
3684 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
,SCTP_NULL());
3685 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
3686 SCTP_ERROR(ECONNABORTED
));
3687 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
3688 SCTP_PERR(SCTP_ERROR_ASCONF_ACK
));
3689 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
3690 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
3691 return SCTP_DISPOSITION_ABORT
;
3694 if ((rcvd_serial
== sent_serial
) && asoc
->addip_last_asconf
) {
3695 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3696 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
3698 if (!sctp_process_asconf_ack((struct sctp_association
*)asoc
,
3700 /* Successfully processed ASCONF_ACK. We can
3701 * release the next asconf if we have one.
3703 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_NEXT_ASCONF
,
3705 return SCTP_DISPOSITION_CONSUME
;
3708 abort
= sctp_make_abort(asoc
, asconf_ack
,
3709 sizeof(sctp_errhdr_t
));
3711 sctp_init_cause(abort
, SCTP_ERROR_RSRC_LOW
, 0);
3712 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
3715 /* We are going to ABORT, so we might as well stop
3716 * processing the rest of the chunks in the packet.
3718 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
,SCTP_NULL());
3719 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
3720 SCTP_ERROR(ECONNABORTED
));
3721 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
3722 SCTP_PERR(SCTP_ERROR_ASCONF_ACK
));
3723 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
3724 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
3725 return SCTP_DISPOSITION_ABORT
;
3728 return SCTP_DISPOSITION_DISCARD
;
3732 * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP
3734 * When a FORWARD TSN chunk arrives, the data receiver MUST first update
3735 * its cumulative TSN point to the value carried in the FORWARD TSN
3736 * chunk, and then MUST further advance its cumulative TSN point locally
3738 * After the above processing, the data receiver MUST stop reporting any
3739 * missing TSNs earlier than or equal to the new cumulative TSN point.
3741 * Verification Tag: 8.5 Verification Tag [Normal verification]
3743 * The return value is the disposition of the chunk.
3745 sctp_disposition_t
sctp_sf_eat_fwd_tsn(const struct sctp_endpoint
*ep
,
3746 const struct sctp_association
*asoc
,
3747 const sctp_subtype_t type
,
3749 sctp_cmd_seq_t
*commands
)
3751 struct sctp_chunk
*chunk
= arg
;
3752 struct sctp_fwdtsn_hdr
*fwdtsn_hdr
;
3753 struct sctp_fwdtsn_skip
*skip
;
3757 if (!sctp_vtag_verify(chunk
, asoc
)) {
3758 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3760 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3763 /* Make sure that the FORWARD_TSN chunk has valid length. */
3764 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_fwdtsn_chunk
)))
3765 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3768 fwdtsn_hdr
= (struct sctp_fwdtsn_hdr
*)chunk
->skb
->data
;
3769 chunk
->subh
.fwdtsn_hdr
= fwdtsn_hdr
;
3770 len
= ntohs(chunk
->chunk_hdr
->length
);
3771 len
-= sizeof(struct sctp_chunkhdr
);
3772 skb_pull(chunk
->skb
, len
);
3774 tsn
= ntohl(fwdtsn_hdr
->new_cum_tsn
);
3775 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __func__
, tsn
);
3777 /* The TSN is too high--silently discard the chunk and count on it
3778 * getting retransmitted later.
3780 if (sctp_tsnmap_check(&asoc
->peer
.tsn_map
, tsn
) < 0)
3781 goto discard_noforce
;
3783 /* Silently discard the chunk if stream-id is not valid */
3784 sctp_walk_fwdtsn(skip
, chunk
) {
3785 if (ntohs(skip
->stream
) >= asoc
->c
.sinit_max_instreams
)
3786 goto discard_noforce
;
3789 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_FWDTSN
, SCTP_U32(tsn
));
3790 if (len
> sizeof(struct sctp_fwdtsn_hdr
))
3791 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_FWDTSN
,
3794 /* Count this as receiving DATA. */
3795 if (asoc
->autoclose
) {
3796 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
3797 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
3800 /* FIXME: For now send a SACK, but DATA processing may
3803 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_NOFORCE());
3805 return SCTP_DISPOSITION_CONSUME
;
3808 return SCTP_DISPOSITION_DISCARD
;
3811 sctp_disposition_t
sctp_sf_eat_fwd_tsn_fast(
3812 const struct sctp_endpoint
*ep
,
3813 const struct sctp_association
*asoc
,
3814 const sctp_subtype_t type
,
3816 sctp_cmd_seq_t
*commands
)
3818 struct sctp_chunk
*chunk
= arg
;
3819 struct sctp_fwdtsn_hdr
*fwdtsn_hdr
;
3820 struct sctp_fwdtsn_skip
*skip
;
3824 if (!sctp_vtag_verify(chunk
, asoc
)) {
3825 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3827 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3830 /* Make sure that the FORWARD_TSN chunk has a valid length. */
3831 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_fwdtsn_chunk
)))
3832 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3835 fwdtsn_hdr
= (struct sctp_fwdtsn_hdr
*)chunk
->skb
->data
;
3836 chunk
->subh
.fwdtsn_hdr
= fwdtsn_hdr
;
3837 len
= ntohs(chunk
->chunk_hdr
->length
);
3838 len
-= sizeof(struct sctp_chunkhdr
);
3839 skb_pull(chunk
->skb
, len
);
3841 tsn
= ntohl(fwdtsn_hdr
->new_cum_tsn
);
3842 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __func__
, tsn
);
3844 /* The TSN is too high--silently discard the chunk and count on it
3845 * getting retransmitted later.
3847 if (sctp_tsnmap_check(&asoc
->peer
.tsn_map
, tsn
) < 0)
3850 /* Silently discard the chunk if stream-id is not valid */
3851 sctp_walk_fwdtsn(skip
, chunk
) {
3852 if (ntohs(skip
->stream
) >= asoc
->c
.sinit_max_instreams
)
3856 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_FWDTSN
, SCTP_U32(tsn
));
3857 if (len
> sizeof(struct sctp_fwdtsn_hdr
))
3858 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_FWDTSN
,
3861 /* Go a head and force a SACK, since we are shutting down. */
3863 /* Implementor's Guide.
3865 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3866 * respond to each received packet containing one or more DATA chunk(s)
3867 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3869 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SHUTDOWN
, SCTP_NULL());
3870 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_FORCE());
3871 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
3872 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
3874 return SCTP_DISPOSITION_CONSUME
;
3878 * SCTP-AUTH Section 6.3 Receiving authenticated chukns
3880 * The receiver MUST use the HMAC algorithm indicated in the HMAC
3881 * Identifier field. If this algorithm was not specified by the
3882 * receiver in the HMAC-ALGO parameter in the INIT or INIT-ACK chunk
3883 * during association setup, the AUTH chunk and all chunks after it MUST
3884 * be discarded and an ERROR chunk SHOULD be sent with the error cause
3885 * defined in Section 4.1.
3887 * If an endpoint with no shared key receives a Shared Key Identifier
3888 * other than 0, it MUST silently discard all authenticated chunks. If
3889 * the endpoint has at least one endpoint pair shared key for the peer,
3890 * it MUST use the key specified by the Shared Key Identifier if a
3891 * key has been configured for that Shared Key Identifier. If no
3892 * endpoint pair shared key has been configured for that Shared Key
3893 * Identifier, all authenticated chunks MUST be silently discarded.
3895 * Verification Tag: 8.5 Verification Tag [Normal verification]
3897 * The return value is the disposition of the chunk.
3899 static sctp_ierror_t
sctp_sf_authenticate(const struct sctp_endpoint
*ep
,
3900 const struct sctp_association
*asoc
,
3901 const sctp_subtype_t type
,
3902 struct sctp_chunk
*chunk
)
3904 struct sctp_authhdr
*auth_hdr
;
3905 struct sctp_hmac
*hmac
;
3906 unsigned int sig_len
;
3911 /* Pull in the auth header, so we can do some more verification */
3912 auth_hdr
= (struct sctp_authhdr
*)chunk
->skb
->data
;
3913 chunk
->subh
.auth_hdr
= auth_hdr
;
3914 skb_pull(chunk
->skb
, sizeof(struct sctp_authhdr
));
3916 /* Make sure that we suport the HMAC algorithm from the auth
3919 if (!sctp_auth_asoc_verify_hmac_id(asoc
, auth_hdr
->hmac_id
))
3920 return SCTP_IERROR_AUTH_BAD_HMAC
;
3922 /* Make sure that the provided shared key identifier has been
3925 key_id
= ntohs(auth_hdr
->shkey_id
);
3926 if (key_id
!= asoc
->active_key_id
&& !sctp_auth_get_shkey(asoc
, key_id
))
3927 return SCTP_IERROR_AUTH_BAD_KEYID
;
3930 /* Make sure that the length of the signature matches what
3933 sig_len
= ntohs(chunk
->chunk_hdr
->length
) - sizeof(sctp_auth_chunk_t
);
3934 hmac
= sctp_auth_get_hmac(ntohs(auth_hdr
->hmac_id
));
3935 if (sig_len
!= hmac
->hmac_len
)
3936 return SCTP_IERROR_PROTO_VIOLATION
;
3938 /* Now that we've done validation checks, we can compute and
3939 * verify the hmac. The steps involved are:
3940 * 1. Save the digest from the chunk.
3941 * 2. Zero out the digest in the chunk.
3942 * 3. Compute the new digest
3943 * 4. Compare saved and new digests.
3945 digest
= auth_hdr
->hmac
;
3946 skb_pull(chunk
->skb
, sig_len
);
3948 save_digest
= kmemdup(digest
, sig_len
, GFP_ATOMIC
);
3952 memset(digest
, 0, sig_len
);
3954 sctp_auth_calculate_hmac(asoc
, chunk
->skb
,
3955 (struct sctp_auth_chunk
*)chunk
->chunk_hdr
,
3958 /* Discard the packet if the digests do not match */
3959 if (memcmp(save_digest
, digest
, sig_len
)) {
3961 return SCTP_IERROR_BAD_SIG
;
3967 return SCTP_IERROR_NO_ERROR
;
3969 return SCTP_IERROR_NOMEM
;
3972 sctp_disposition_t
sctp_sf_eat_auth(const struct sctp_endpoint
*ep
,
3973 const struct sctp_association
*asoc
,
3974 const sctp_subtype_t type
,
3976 sctp_cmd_seq_t
*commands
)
3978 struct sctp_authhdr
*auth_hdr
;
3979 struct sctp_chunk
*chunk
= arg
;
3980 struct sctp_chunk
*err_chunk
;
3981 sctp_ierror_t error
;
3983 /* Make sure that the peer has AUTH capable */
3984 if (!asoc
->peer
.auth_capable
)
3985 return sctp_sf_unk_chunk(ep
, asoc
, type
, arg
, commands
);
3987 if (!sctp_vtag_verify(chunk
, asoc
)) {
3988 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3990 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3993 /* Make sure that the AUTH chunk has valid length. */
3994 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_auth_chunk
)))
3995 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3998 auth_hdr
= (struct sctp_authhdr
*)chunk
->skb
->data
;
3999 error
= sctp_sf_authenticate(ep
, asoc
, type
, chunk
);
4001 case SCTP_IERROR_AUTH_BAD_HMAC
:
4002 /* Generate the ERROR chunk and discard the rest
4005 err_chunk
= sctp_make_op_error(asoc
, chunk
,
4006 SCTP_ERROR_UNSUP_HMAC
,
4010 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
4011 SCTP_CHUNK(err_chunk
));
4014 case SCTP_IERROR_AUTH_BAD_KEYID
:
4015 case SCTP_IERROR_BAD_SIG
:
4016 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
4018 case SCTP_IERROR_PROTO_VIOLATION
:
4019 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
4022 case SCTP_IERROR_NOMEM
:
4023 return SCTP_DISPOSITION_NOMEM
;
4028 if (asoc
->active_key_id
!= ntohs(auth_hdr
->shkey_id
)) {
4029 struct sctp_ulpevent
*ev
;
4031 ev
= sctp_ulpevent_make_authkey(asoc
, ntohs(auth_hdr
->shkey_id
),
4032 SCTP_AUTH_NEWKEY
, GFP_ATOMIC
);
4037 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
4041 return SCTP_DISPOSITION_CONSUME
;
4045 * Process an unknown chunk.
4047 * Section: 3.2. Also, 2.1 in the implementor's guide.
4049 * Chunk Types are encoded such that the highest-order two bits specify
4050 * the action that must be taken if the processing endpoint does not
4051 * recognize the Chunk Type.
4053 * 00 - Stop processing this SCTP packet and discard it, do not process
4054 * any further chunks within it.
4056 * 01 - Stop processing this SCTP packet and discard it, do not process
4057 * any further chunks within it, and report the unrecognized
4058 * chunk in an 'Unrecognized Chunk Type'.
4060 * 10 - Skip this chunk and continue processing.
4062 * 11 - Skip this chunk and continue processing, but report in an ERROR
4063 * Chunk using the 'Unrecognized Chunk Type' cause of error.
4065 * The return value is the disposition of the chunk.
4067 sctp_disposition_t
sctp_sf_unk_chunk(const struct sctp_endpoint
*ep
,
4068 const struct sctp_association
*asoc
,
4069 const sctp_subtype_t type
,
4071 sctp_cmd_seq_t
*commands
)
4073 struct sctp_chunk
*unk_chunk
= arg
;
4074 struct sctp_chunk
*err_chunk
;
4075 sctp_chunkhdr_t
*hdr
;
4077 SCTP_DEBUG_PRINTK("Processing the unknown chunk id %d.\n", type
.chunk
);
4079 if (!sctp_vtag_verify(unk_chunk
, asoc
))
4080 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
4082 /* Make sure that the chunk has a valid length.
4083 * Since we don't know the chunk type, we use a general
4084 * chunkhdr structure to make a comparison.
4086 if (!sctp_chunk_length_valid(unk_chunk
, sizeof(sctp_chunkhdr_t
)))
4087 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
4090 switch (type
.chunk
& SCTP_CID_ACTION_MASK
) {
4091 case SCTP_CID_ACTION_DISCARD
:
4092 /* Discard the packet. */
4093 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
4095 case SCTP_CID_ACTION_DISCARD_ERR
:
4096 /* Generate an ERROR chunk as response. */
4097 hdr
= unk_chunk
->chunk_hdr
;
4098 err_chunk
= sctp_make_op_error(asoc
, unk_chunk
,
4099 SCTP_ERROR_UNKNOWN_CHUNK
, hdr
,
4100 WORD_ROUND(ntohs(hdr
->length
)),
4103 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
4104 SCTP_CHUNK(err_chunk
));
4107 /* Discard the packet. */
4108 sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
4109 return SCTP_DISPOSITION_CONSUME
;
4111 case SCTP_CID_ACTION_SKIP
:
4112 /* Skip the chunk. */
4113 return SCTP_DISPOSITION_DISCARD
;
4115 case SCTP_CID_ACTION_SKIP_ERR
:
4116 /* Generate an ERROR chunk as response. */
4117 hdr
= unk_chunk
->chunk_hdr
;
4118 err_chunk
= sctp_make_op_error(asoc
, unk_chunk
,
4119 SCTP_ERROR_UNKNOWN_CHUNK
, hdr
,
4120 WORD_ROUND(ntohs(hdr
->length
)),
4123 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
4124 SCTP_CHUNK(err_chunk
));
4126 /* Skip the chunk. */
4127 return SCTP_DISPOSITION_CONSUME
;
4133 return SCTP_DISPOSITION_DISCARD
;
4137 * Discard the chunk.
4139 * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2
4140 * [Too numerous to mention...]
4141 * Verification Tag: No verification needed.
4143 * (endpoint, asoc, chunk)
4146 * (asoc, reply_msg, msg_up, timers, counters)
4148 * The return value is the disposition of the chunk.
4150 sctp_disposition_t
sctp_sf_discard_chunk(const struct sctp_endpoint
*ep
,
4151 const struct sctp_association
*asoc
,
4152 const sctp_subtype_t type
,
4154 sctp_cmd_seq_t
*commands
)
4156 struct sctp_chunk
*chunk
= arg
;
4158 /* Make sure that the chunk has a valid length.
4159 * Since we don't know the chunk type, we use a general
4160 * chunkhdr structure to make a comparison.
4162 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
4163 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
4166 SCTP_DEBUG_PRINTK("Chunk %d is discarded\n", type
.chunk
);
4167 return SCTP_DISPOSITION_DISCARD
;
4171 * Discard the whole packet.
4175 * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST
4176 * silently discard the OOTB packet and take no further action.
4178 * Verification Tag: No verification necessary
4181 * (endpoint, asoc, chunk)
4184 * (asoc, reply_msg, msg_up, timers, counters)
4186 * The return value is the disposition of the chunk.
4188 sctp_disposition_t
sctp_sf_pdiscard(const struct sctp_endpoint
*ep
,
4189 const struct sctp_association
*asoc
,
4190 const sctp_subtype_t type
,
4192 sctp_cmd_seq_t
*commands
)
4194 SCTP_INC_STATS(SCTP_MIB_IN_PKT_DISCARDS
);
4195 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
, SCTP_NULL());
4197 return SCTP_DISPOSITION_CONSUME
;
4202 * The other end is violating protocol.
4204 * Section: Not specified
4205 * Verification Tag: Not specified
4207 * (endpoint, asoc, chunk)
4210 * (asoc, reply_msg, msg_up, timers, counters)
4212 * We simply tag the chunk as a violation. The state machine will log
4213 * the violation and continue.
4215 sctp_disposition_t
sctp_sf_violation(const struct sctp_endpoint
*ep
,
4216 const struct sctp_association
*asoc
,
4217 const sctp_subtype_t type
,
4219 sctp_cmd_seq_t
*commands
)
4221 struct sctp_chunk
*chunk
= arg
;
4223 /* Make sure that the chunk has a valid length. */
4224 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
4225 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
4228 return SCTP_DISPOSITION_VIOLATION
;
4232 * Common function to handle a protocol violation.
4234 static sctp_disposition_t
sctp_sf_abort_violation(
4235 const struct sctp_endpoint
*ep
,
4236 const struct sctp_association
*asoc
,
4238 sctp_cmd_seq_t
*commands
,
4239 const __u8
*payload
,
4240 const size_t paylen
)
4242 struct sctp_packet
*packet
= NULL
;
4243 struct sctp_chunk
*chunk
= arg
;
4244 struct sctp_chunk
*abort
= NULL
;
4246 /* SCTP-AUTH, Section 6.3:
4247 * It should be noted that if the receiver wants to tear
4248 * down an association in an authenticated way only, the
4249 * handling of malformed packets should not result in
4250 * tearing down the association.
4252 * This means that if we only want to abort associations
4253 * in an authenticated way (i.e AUTH+ABORT), then we
4254 * can't destroy this association just because the packet
4257 if (sctp_auth_recv_cid(SCTP_CID_ABORT
, asoc
))
4260 /* Make the abort chunk. */
4261 abort
= sctp_make_abort_violation(asoc
, chunk
, payload
, paylen
);
4266 /* Treat INIT-ACK as a special case during COOKIE-WAIT. */
4267 if (chunk
->chunk_hdr
->type
== SCTP_CID_INIT_ACK
&&
4268 !asoc
->peer
.i
.init_tag
) {
4269 sctp_initack_chunk_t
*initack
;
4271 initack
= (sctp_initack_chunk_t
*)chunk
->chunk_hdr
;
4272 if (!sctp_chunk_length_valid(chunk
,
4273 sizeof(sctp_initack_chunk_t
)))
4274 abort
->chunk_hdr
->flags
|= SCTP_CHUNK_FLAG_T
;
4276 unsigned int inittag
;
4278 inittag
= ntohl(initack
->init_hdr
.init_tag
);
4279 sctp_add_cmd_sf(commands
, SCTP_CMD_UPDATE_INITTAG
,
4284 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(abort
));
4285 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
4287 if (asoc
->state
<= SCTP_STATE_COOKIE_ECHOED
) {
4288 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4289 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
4290 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
4291 SCTP_ERROR(ECONNREFUSED
));
4292 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
4293 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION
));
4295 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
4296 SCTP_ERROR(ECONNABORTED
));
4297 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
4298 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION
));
4299 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
4302 packet
= sctp_ootb_pkt_new(asoc
, chunk
);
4307 if (sctp_test_T_bit(abort
))
4308 packet
->vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
4310 abort
->skb
->sk
= ep
->base
.sk
;
4312 sctp_packet_append_chunk(packet
, abort
);
4314 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
4315 SCTP_PACKET(packet
));
4317 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
4320 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
4323 sctp_sf_pdiscard(ep
, asoc
, SCTP_ST_CHUNK(0), arg
, commands
);
4324 return SCTP_DISPOSITION_ABORT
;
4327 sctp_chunk_free(abort
);
4329 return SCTP_DISPOSITION_NOMEM
;
4333 * Handle a protocol violation when the chunk length is invalid.
4334 * "Invalid" length is identified as smaller than the minimal length a
4335 * given chunk can be. For example, a SACK chunk has invalid length
4336 * if its length is set to be smaller than the size of sctp_sack_chunk_t.
4338 * We inform the other end by sending an ABORT with a Protocol Violation
4341 * Section: Not specified
4342 * Verification Tag: Nothing to do
4344 * (endpoint, asoc, chunk)
4347 * (reply_msg, msg_up, counters)
4349 * Generate an ABORT chunk and terminate the association.
4351 static sctp_disposition_t
sctp_sf_violation_chunklen(
4352 const struct sctp_endpoint
*ep
,
4353 const struct sctp_association
*asoc
,
4354 const sctp_subtype_t type
,
4356 sctp_cmd_seq_t
*commands
)
4358 static const char err_str
[]="The following chunk had invalid length:";
4360 return sctp_sf_abort_violation(ep
, asoc
, arg
, commands
, err_str
,
4365 * Handle a protocol violation when the parameter length is invalid.
4366 * If the length is smaller than the minimum length of a given parameter,
4367 * or accumulated length in multi parameters exceeds the end of the chunk,
4368 * the length is considered as invalid.
4370 static sctp_disposition_t
sctp_sf_violation_paramlen(
4371 const struct sctp_endpoint
*ep
,
4372 const struct sctp_association
*asoc
,
4373 const sctp_subtype_t type
,
4374 void *arg
, void *ext
,
4375 sctp_cmd_seq_t
*commands
)
4377 struct sctp_chunk
*chunk
= arg
;
4378 struct sctp_paramhdr
*param
= ext
;
4379 struct sctp_chunk
*abort
= NULL
;
4381 if (sctp_auth_recv_cid(SCTP_CID_ABORT
, asoc
))
4384 /* Make the abort chunk. */
4385 abort
= sctp_make_violation_paramlen(asoc
, chunk
, param
);
4389 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(abort
));
4390 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
4392 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
4393 SCTP_ERROR(ECONNABORTED
));
4394 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
4395 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION
));
4396 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
4397 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
4400 sctp_sf_pdiscard(ep
, asoc
, SCTP_ST_CHUNK(0), arg
, commands
);
4401 return SCTP_DISPOSITION_ABORT
;
4403 return SCTP_DISPOSITION_NOMEM
;
4406 /* Handle a protocol violation when the peer trying to advance the
4407 * cumulative tsn ack to a point beyond the max tsn currently sent.
4409 * We inform the other end by sending an ABORT with a Protocol Violation
4412 static sctp_disposition_t
sctp_sf_violation_ctsn(
4413 const struct sctp_endpoint
*ep
,
4414 const struct sctp_association
*asoc
,
4415 const sctp_subtype_t type
,
4417 sctp_cmd_seq_t
*commands
)
4419 static const char err_str
[]="The cumulative tsn ack beyond the max tsn currently sent:";
4421 return sctp_sf_abort_violation(ep
, asoc
, arg
, commands
, err_str
,
4425 /* Handle protocol violation of an invalid chunk bundling. For example,
4426 * when we have an association and we receive bundled INIT-ACK, or
4427 * SHUDOWN-COMPLETE, our peer is clearly violationg the "MUST NOT bundle"
4428 * statement from the specs. Additionally, there might be an attacker
4429 * on the path and we may not want to continue this communication.
4431 static sctp_disposition_t
sctp_sf_violation_chunk(
4432 const struct sctp_endpoint
*ep
,
4433 const struct sctp_association
*asoc
,
4434 const sctp_subtype_t type
,
4436 sctp_cmd_seq_t
*commands
)
4438 static const char err_str
[]="The following chunk violates protocol:";
4441 return sctp_sf_violation(ep
, asoc
, type
, arg
, commands
);
4443 return sctp_sf_abort_violation(ep
, asoc
, arg
, commands
, err_str
,
4446 /***************************************************************************
4447 * These are the state functions for handling primitive (Section 10) events.
4448 ***************************************************************************/
4450 * sctp_sf_do_prm_asoc
4452 * Section: 10.1 ULP-to-SCTP
4455 * Format: ASSOCIATE(local SCTP instance name, destination transport addr,
4456 * outbound stream count)
4457 * -> association id [,destination transport addr list] [,outbound stream
4460 * This primitive allows the upper layer to initiate an association to a
4461 * specific peer endpoint.
4463 * The peer endpoint shall be specified by one of the transport addresses
4464 * which defines the endpoint (see Section 1.4). If the local SCTP
4465 * instance has not been initialized, the ASSOCIATE is considered an
4467 * [This is not relevant for the kernel implementation since we do all
4468 * initialization at boot time. It we hadn't initialized we wouldn't
4469 * get anywhere near this code.]
4471 * An association id, which is a local handle to the SCTP association,
4472 * will be returned on successful establishment of the association. If
4473 * SCTP is not able to open an SCTP association with the peer endpoint,
4474 * an error is returned.
4475 * [In the kernel implementation, the struct sctp_association needs to
4476 * be created BEFORE causing this primitive to run.]
4478 * Other association parameters may be returned, including the
4479 * complete destination transport addresses of the peer as well as the
4480 * outbound stream count of the local endpoint. One of the transport
4481 * address from the returned destination addresses will be selected by
4482 * the local endpoint as default primary path for sending SCTP packets
4483 * to this peer. The returned "destination transport addr list" can
4484 * be used by the ULP to change the default primary path or to force
4485 * sending a packet to a specific transport address. [All of this
4486 * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING
4489 * Mandatory attributes:
4491 * o local SCTP instance name - obtained from the INITIALIZE operation.
4492 * [This is the argument asoc.]
4493 * o destination transport addr - specified as one of the transport
4494 * addresses of the peer endpoint with which the association is to be
4496 * [This is asoc->peer.active_path.]
4497 * o outbound stream count - the number of outbound streams the ULP
4498 * would like to open towards this peer endpoint.
4499 * [BUG: This is not currently implemented.]
4500 * Optional attributes:
4504 * The return value is a disposition.
4506 sctp_disposition_t
sctp_sf_do_prm_asoc(const struct sctp_endpoint
*ep
,
4507 const struct sctp_association
*asoc
,
4508 const sctp_subtype_t type
,
4510 sctp_cmd_seq_t
*commands
)
4512 struct sctp_chunk
*repl
;
4513 struct sctp_association
* my_asoc
;
4515 /* The comment below says that we enter COOKIE-WAIT AFTER
4516 * sending the INIT, but that doesn't actually work in our
4519 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
4520 SCTP_STATE(SCTP_STATE_COOKIE_WAIT
));
4522 /* RFC 2960 5.1 Normal Establishment of an Association
4524 * A) "A" first sends an INIT chunk to "Z". In the INIT, "A"
4525 * must provide its Verification Tag (Tag_A) in the Initiate
4526 * Tag field. Tag_A SHOULD be a random number in the range of
4527 * 1 to 4294967295 (see 5.3.1 for Tag value selection). ...
4530 repl
= sctp_make_init(asoc
, &asoc
->base
.bind_addr
, GFP_ATOMIC
, 0);
4534 /* Cast away the const modifier, as we want to just
4535 * rerun it through as a sideffect.
4537 my_asoc
= (struct sctp_association
*)asoc
;
4538 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(my_asoc
));
4540 /* Choose transport for INIT. */
4541 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_CHOOSE_TRANSPORT
,
4544 /* After sending the INIT, "A" starts the T1-init timer and
4545 * enters the COOKIE-WAIT state.
4547 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
4548 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
4549 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
4550 return SCTP_DISPOSITION_CONSUME
;
4553 return SCTP_DISPOSITION_NOMEM
;
4557 * Process the SEND primitive.
4559 * Section: 10.1 ULP-to-SCTP
4562 * Format: SEND(association id, buffer address, byte count [,context]
4563 * [,stream id] [,life time] [,destination transport address]
4564 * [,unorder flag] [,no-bundle flag] [,payload protocol-id] )
4567 * This is the main method to send user data via SCTP.
4569 * Mandatory attributes:
4571 * o association id - local handle to the SCTP association
4573 * o buffer address - the location where the user message to be
4574 * transmitted is stored;
4576 * o byte count - The size of the user data in number of bytes;
4578 * Optional attributes:
4580 * o context - an optional 32 bit integer that will be carried in the
4581 * sending failure notification to the ULP if the transportation of
4582 * this User Message fails.
4584 * o stream id - to indicate which stream to send the data on. If not
4585 * specified, stream 0 will be used.
4587 * o life time - specifies the life time of the user data. The user data
4588 * will not be sent by SCTP after the life time expires. This
4589 * parameter can be used to avoid efforts to transmit stale
4590 * user messages. SCTP notifies the ULP if the data cannot be
4591 * initiated to transport (i.e. sent to the destination via SCTP's
4592 * send primitive) within the life time variable. However, the
4593 * user data will be transmitted if SCTP has attempted to transmit a
4594 * chunk before the life time expired.
4596 * o destination transport address - specified as one of the destination
4597 * transport addresses of the peer endpoint to which this packet
4598 * should be sent. Whenever possible, SCTP should use this destination
4599 * transport address for sending the packets, instead of the current
4602 * o unorder flag - this flag, if present, indicates that the user
4603 * would like the data delivered in an unordered fashion to the peer
4604 * (i.e., the U flag is set to 1 on all DATA chunks carrying this
4607 * o no-bundle flag - instructs SCTP not to bundle this user data with
4608 * other outbound DATA chunks. SCTP MAY still bundle even when
4609 * this flag is present, when faced with network congestion.
4611 * o payload protocol-id - A 32 bit unsigned integer that is to be
4612 * passed to the peer indicating the type of payload protocol data
4613 * being transmitted. This value is passed as opaque data by SCTP.
4615 * The return value is the disposition.
4617 sctp_disposition_t
sctp_sf_do_prm_send(const struct sctp_endpoint
*ep
,
4618 const struct sctp_association
*asoc
,
4619 const sctp_subtype_t type
,
4621 sctp_cmd_seq_t
*commands
)
4623 struct sctp_datamsg
*msg
= arg
;
4625 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_MSG
, SCTP_DATAMSG(msg
));
4626 return SCTP_DISPOSITION_CONSUME
;
4630 * Process the SHUTDOWN primitive.
4635 * Format: SHUTDOWN(association id)
4638 * Gracefully closes an association. Any locally queued user data
4639 * will be delivered to the peer. The association will be terminated only
4640 * after the peer acknowledges all the SCTP packets sent. A success code
4641 * will be returned on successful termination of the association. If
4642 * attempting to terminate the association results in a failure, an error
4643 * code shall be returned.
4645 * Mandatory attributes:
4647 * o association id - local handle to the SCTP association
4649 * Optional attributes:
4653 * The return value is the disposition.
4655 sctp_disposition_t
sctp_sf_do_9_2_prm_shutdown(
4656 const struct sctp_endpoint
*ep
,
4657 const struct sctp_association
*asoc
,
4658 const sctp_subtype_t type
,
4660 sctp_cmd_seq_t
*commands
)
4664 /* From 9.2 Shutdown of an Association
4665 * Upon receipt of the SHUTDOWN primitive from its upper
4666 * layer, the endpoint enters SHUTDOWN-PENDING state and
4667 * remains there until all outstanding data has been
4668 * acknowledged by its peer. The endpoint accepts no new data
4669 * from its upper layer, but retransmits data to the far end
4670 * if necessary to fill gaps.
4672 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
4673 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING
));
4675 disposition
= SCTP_DISPOSITION_CONSUME
;
4676 if (sctp_outq_is_empty(&asoc
->outqueue
)) {
4677 disposition
= sctp_sf_do_9_2_start_shutdown(ep
, asoc
, type
,
4684 * Process the ABORT primitive.
4689 * Format: Abort(association id [, cause code])
4692 * Ungracefully closes an association. Any locally queued user data
4693 * will be discarded and an ABORT chunk is sent to the peer. A success code
4694 * will be returned on successful abortion of the association. If
4695 * attempting to abort the association results in a failure, an error
4696 * code shall be returned.
4698 * Mandatory attributes:
4700 * o association id - local handle to the SCTP association
4702 * Optional attributes:
4704 * o cause code - reason of the abort to be passed to the peer
4708 * The return value is the disposition.
4710 sctp_disposition_t
sctp_sf_do_9_1_prm_abort(
4711 const struct sctp_endpoint
*ep
,
4712 const struct sctp_association
*asoc
,
4713 const sctp_subtype_t type
,
4715 sctp_cmd_seq_t
*commands
)
4717 /* From 9.1 Abort of an Association
4718 * Upon receipt of the ABORT primitive from its upper
4719 * layer, the endpoint enters CLOSED state and
4720 * discard all outstanding data has been
4721 * acknowledged by its peer. The endpoint accepts no new data
4722 * from its upper layer, but retransmits data to the far end
4723 * if necessary to fill gaps.
4725 struct sctp_chunk
*abort
= arg
;
4726 sctp_disposition_t retval
;
4728 retval
= SCTP_DISPOSITION_CONSUME
;
4730 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(abort
));
4732 /* Even if we can't send the ABORT due to low memory delete the
4733 * TCB. This is a departure from our typical NOMEM handling.
4736 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
4737 SCTP_ERROR(ECONNABORTED
));
4738 /* Delete the established association. */
4739 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
4740 SCTP_PERR(SCTP_ERROR_USER_ABORT
));
4742 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
4743 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
4748 /* We tried an illegal operation on an association which is closed. */
4749 sctp_disposition_t
sctp_sf_error_closed(const struct sctp_endpoint
*ep
,
4750 const struct sctp_association
*asoc
,
4751 const sctp_subtype_t type
,
4753 sctp_cmd_seq_t
*commands
)
4755 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_ERROR
, SCTP_ERROR(-EINVAL
));
4756 return SCTP_DISPOSITION_CONSUME
;
4759 /* We tried an illegal operation on an association which is shutting
4762 sctp_disposition_t
sctp_sf_error_shutdown(const struct sctp_endpoint
*ep
,
4763 const struct sctp_association
*asoc
,
4764 const sctp_subtype_t type
,
4766 sctp_cmd_seq_t
*commands
)
4768 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_ERROR
,
4769 SCTP_ERROR(-ESHUTDOWN
));
4770 return SCTP_DISPOSITION_CONSUME
;
4774 * sctp_cookie_wait_prm_shutdown
4776 * Section: 4 Note: 2
4781 * The RFC does not explicitly address this issue, but is the route through the
4782 * state table when someone issues a shutdown while in COOKIE_WAIT state.
4787 sctp_disposition_t
sctp_sf_cookie_wait_prm_shutdown(
4788 const struct sctp_endpoint
*ep
,
4789 const struct sctp_association
*asoc
,
4790 const sctp_subtype_t type
,
4792 sctp_cmd_seq_t
*commands
)
4794 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4795 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
4797 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
4798 SCTP_STATE(SCTP_STATE_CLOSED
));
4800 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS
);
4802 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
4804 return SCTP_DISPOSITION_DELETE_TCB
;
4808 * sctp_cookie_echoed_prm_shutdown
4810 * Section: 4 Note: 2
4815 * The RFC does not explcitly address this issue, but is the route through the
4816 * state table when someone issues a shutdown while in COOKIE_ECHOED state.
4821 sctp_disposition_t
sctp_sf_cookie_echoed_prm_shutdown(
4822 const struct sctp_endpoint
*ep
,
4823 const struct sctp_association
*asoc
,
4824 const sctp_subtype_t type
,
4825 void *arg
, sctp_cmd_seq_t
*commands
)
4827 /* There is a single T1 timer, so we should be able to use
4828 * common function with the COOKIE-WAIT state.
4830 return sctp_sf_cookie_wait_prm_shutdown(ep
, asoc
, type
, arg
, commands
);
4834 * sctp_sf_cookie_wait_prm_abort
4836 * Section: 4 Note: 2
4841 * The RFC does not explicitly address this issue, but is the route through the
4842 * state table when someone issues an abort while in COOKIE_WAIT state.
4847 sctp_disposition_t
sctp_sf_cookie_wait_prm_abort(
4848 const struct sctp_endpoint
*ep
,
4849 const struct sctp_association
*asoc
,
4850 const sctp_subtype_t type
,
4852 sctp_cmd_seq_t
*commands
)
4854 struct sctp_chunk
*abort
= arg
;
4855 sctp_disposition_t retval
;
4857 /* Stop T1-init timer */
4858 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4859 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
4860 retval
= SCTP_DISPOSITION_CONSUME
;
4862 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(abort
));
4864 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
4865 SCTP_STATE(SCTP_STATE_CLOSED
));
4867 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
4869 /* Even if we can't send the ABORT due to low memory delete the
4870 * TCB. This is a departure from our typical NOMEM handling.
4873 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
4874 SCTP_ERROR(ECONNREFUSED
));
4875 /* Delete the established association. */
4876 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
4877 SCTP_PERR(SCTP_ERROR_USER_ABORT
));
4883 * sctp_sf_cookie_echoed_prm_abort
4885 * Section: 4 Note: 3
4890 * The RFC does not explcitly address this issue, but is the route through the
4891 * state table when someone issues an abort while in COOKIE_ECHOED state.
4896 sctp_disposition_t
sctp_sf_cookie_echoed_prm_abort(
4897 const struct sctp_endpoint
*ep
,
4898 const struct sctp_association
*asoc
,
4899 const sctp_subtype_t type
,
4901 sctp_cmd_seq_t
*commands
)
4903 /* There is a single T1 timer, so we should be able to use
4904 * common function with the COOKIE-WAIT state.
4906 return sctp_sf_cookie_wait_prm_abort(ep
, asoc
, type
, arg
, commands
);
4910 * sctp_sf_shutdown_pending_prm_abort
4915 * The RFC does not explicitly address this issue, but is the route through the
4916 * state table when someone issues an abort while in SHUTDOWN-PENDING state.
4921 sctp_disposition_t
sctp_sf_shutdown_pending_prm_abort(
4922 const struct sctp_endpoint
*ep
,
4923 const struct sctp_association
*asoc
,
4924 const sctp_subtype_t type
,
4926 sctp_cmd_seq_t
*commands
)
4928 /* Stop the T5-shutdown guard timer. */
4929 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4930 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
4932 return sctp_sf_do_9_1_prm_abort(ep
, asoc
, type
, arg
, commands
);
4936 * sctp_sf_shutdown_sent_prm_abort
4941 * The RFC does not explicitly address this issue, but is the route through the
4942 * state table when someone issues an abort while in SHUTDOWN-SENT state.
4947 sctp_disposition_t
sctp_sf_shutdown_sent_prm_abort(
4948 const struct sctp_endpoint
*ep
,
4949 const struct sctp_association
*asoc
,
4950 const sctp_subtype_t type
,
4952 sctp_cmd_seq_t
*commands
)
4954 /* Stop the T2-shutdown timer. */
4955 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4956 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
4958 /* Stop the T5-shutdown guard timer. */
4959 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4960 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
4962 return sctp_sf_do_9_1_prm_abort(ep
, asoc
, type
, arg
, commands
);
4966 * sctp_sf_cookie_echoed_prm_abort
4971 * The RFC does not explcitly address this issue, but is the route through the
4972 * state table when someone issues an abort while in COOKIE_ECHOED state.
4977 sctp_disposition_t
sctp_sf_shutdown_ack_sent_prm_abort(
4978 const struct sctp_endpoint
*ep
,
4979 const struct sctp_association
*asoc
,
4980 const sctp_subtype_t type
,
4982 sctp_cmd_seq_t
*commands
)
4984 /* The same T2 timer, so we should be able to use
4985 * common function with the SHUTDOWN-SENT state.
4987 return sctp_sf_shutdown_sent_prm_abort(ep
, asoc
, type
, arg
, commands
);
4991 * Process the REQUESTHEARTBEAT primitive
4994 * J) Request Heartbeat
4996 * Format: REQUESTHEARTBEAT(association id, destination transport address)
5000 * Instructs the local endpoint to perform a HeartBeat on the specified
5001 * destination transport address of the given association. The returned
5002 * result should indicate whether the transmission of the HEARTBEAT
5003 * chunk to the destination address is successful.
5005 * Mandatory attributes:
5007 * o association id - local handle to the SCTP association
5009 * o destination transport address - the transport address of the
5010 * association on which a heartbeat should be issued.
5012 sctp_disposition_t
sctp_sf_do_prm_requestheartbeat(
5013 const struct sctp_endpoint
*ep
,
5014 const struct sctp_association
*asoc
,
5015 const sctp_subtype_t type
,
5017 sctp_cmd_seq_t
*commands
)
5019 if (SCTP_DISPOSITION_NOMEM
== sctp_sf_heartbeat(ep
, asoc
, type
,
5020 (struct sctp_transport
*)arg
, commands
))
5021 return SCTP_DISPOSITION_NOMEM
;
5024 * RFC 2960 (bis), section 8.3
5026 * D) Request an on-demand HEARTBEAT on a specific destination
5027 * transport address of a given association.
5029 * The endpoint should increment the respective error counter of
5030 * the destination transport address each time a HEARTBEAT is sent
5031 * to that address and not acknowledged within one RTO.
5034 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSPORT_HB_SENT
,
5035 SCTP_TRANSPORT(arg
));
5036 return SCTP_DISPOSITION_CONSUME
;
5040 * ADDIP Section 4.1 ASCONF Chunk Procedures
5041 * When an endpoint has an ASCONF signaled change to be sent to the
5042 * remote endpoint it should do A1 to A9
5044 sctp_disposition_t
sctp_sf_do_prm_asconf(const struct sctp_endpoint
*ep
,
5045 const struct sctp_association
*asoc
,
5046 const sctp_subtype_t type
,
5048 sctp_cmd_seq_t
*commands
)
5050 struct sctp_chunk
*chunk
= arg
;
5052 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T4
, SCTP_CHUNK(chunk
));
5053 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
5054 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
5055 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(chunk
));
5056 return SCTP_DISPOSITION_CONSUME
;
5060 * Ignore the primitive event
5062 * The return value is the disposition of the primitive.
5064 sctp_disposition_t
sctp_sf_ignore_primitive(
5065 const struct sctp_endpoint
*ep
,
5066 const struct sctp_association
*asoc
,
5067 const sctp_subtype_t type
,
5069 sctp_cmd_seq_t
*commands
)
5071 SCTP_DEBUG_PRINTK("Primitive type %d is ignored.\n", type
.primitive
);
5072 return SCTP_DISPOSITION_DISCARD
;
5075 /***************************************************************************
5076 * These are the state functions for the OTHER events.
5077 ***************************************************************************/
5080 * When the SCTP stack has no more user data to send or retransmit, this
5081 * notification is given to the user. Also, at the time when a user app
5082 * subscribes to this event, if there is no data to be sent or
5083 * retransmit, the stack will immediately send up this notification.
5085 sctp_disposition_t
sctp_sf_do_no_pending_tsn(
5086 const struct sctp_endpoint
*ep
,
5087 const struct sctp_association
*asoc
,
5088 const sctp_subtype_t type
,
5090 sctp_cmd_seq_t
*commands
)
5092 struct sctp_ulpevent
*event
;
5094 event
= sctp_ulpevent_make_sender_dry_event(asoc
, GFP_ATOMIC
);
5096 return SCTP_DISPOSITION_NOMEM
;
5098 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(event
));
5100 return SCTP_DISPOSITION_CONSUME
;
5104 * Start the shutdown negotiation.
5107 * Once all its outstanding data has been acknowledged, the endpoint
5108 * shall send a SHUTDOWN chunk to its peer including in the Cumulative
5109 * TSN Ack field the last sequential TSN it has received from the peer.
5110 * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT
5111 * state. If the timer expires, the endpoint must re-send the SHUTDOWN
5112 * with the updated last sequential TSN received from its peer.
5114 * The return value is the disposition.
5116 sctp_disposition_t
sctp_sf_do_9_2_start_shutdown(
5117 const struct sctp_endpoint
*ep
,
5118 const struct sctp_association
*asoc
,
5119 const sctp_subtype_t type
,
5121 sctp_cmd_seq_t
*commands
)
5123 struct sctp_chunk
*reply
;
5125 /* Once all its outstanding data has been acknowledged, the
5126 * endpoint shall send a SHUTDOWN chunk to its peer including
5127 * in the Cumulative TSN Ack field the last sequential TSN it
5128 * has received from the peer.
5130 reply
= sctp_make_shutdown(asoc
, NULL
);
5134 /* Set the transport for the SHUTDOWN chunk and the timeout for the
5135 * T2-shutdown timer.
5137 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T2
, SCTP_CHUNK(reply
));
5139 /* It shall then start the T2-shutdown timer */
5140 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
5141 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
5143 /* RFC 4960 Section 9.2
5144 * The sender of the SHUTDOWN MAY also start an overall guard timer
5145 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5147 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
5148 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
5150 if (asoc
->autoclose
)
5151 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
5152 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
5154 /* and enter the SHUTDOWN-SENT state. */
5155 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
5156 SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT
));
5158 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5160 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
5163 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_STOP
, SCTP_NULL());
5165 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
5167 return SCTP_DISPOSITION_CONSUME
;
5170 return SCTP_DISPOSITION_NOMEM
;
5174 * Generate a SHUTDOWN ACK now that everything is SACK'd.
5178 * If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5179 * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own,
5180 * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the
5181 * endpoint must re-send the SHUTDOWN ACK.
5183 * The return value is the disposition.
5185 sctp_disposition_t
sctp_sf_do_9_2_shutdown_ack(
5186 const struct sctp_endpoint
*ep
,
5187 const struct sctp_association
*asoc
,
5188 const sctp_subtype_t type
,
5190 sctp_cmd_seq_t
*commands
)
5192 struct sctp_chunk
*chunk
= (struct sctp_chunk
*) arg
;
5193 struct sctp_chunk
*reply
;
5195 /* There are 2 ways of getting here:
5196 * 1) called in response to a SHUTDOWN chunk
5197 * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued.
5199 * For the case (2), the arg parameter is set to NULL. We need
5200 * to check that we have a chunk before accessing it's fields.
5203 if (!sctp_vtag_verify(chunk
, asoc
))
5204 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
5206 /* Make sure that the SHUTDOWN chunk has a valid length. */
5207 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_shutdown_chunk_t
)))
5208 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
5212 /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5213 * shall send a SHUTDOWN ACK ...
5215 reply
= sctp_make_shutdown_ack(asoc
, chunk
);
5219 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
5220 * the T2-shutdown timer.
5222 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T2
, SCTP_CHUNK(reply
));
5224 /* and start/restart a T2-shutdown timer of its own, */
5225 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
5226 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
5228 if (asoc
->autoclose
)
5229 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
5230 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
5232 /* Enter the SHUTDOWN-ACK-SENT state. */
5233 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
5234 SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT
));
5236 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5238 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
5241 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_STOP
, SCTP_NULL());
5243 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
5245 return SCTP_DISPOSITION_CONSUME
;
5248 return SCTP_DISPOSITION_NOMEM
;
5252 * Ignore the event defined as other
5254 * The return value is the disposition of the event.
5256 sctp_disposition_t
sctp_sf_ignore_other(const struct sctp_endpoint
*ep
,
5257 const struct sctp_association
*asoc
,
5258 const sctp_subtype_t type
,
5260 sctp_cmd_seq_t
*commands
)
5262 SCTP_DEBUG_PRINTK("The event other type %d is ignored\n", type
.other
);
5263 return SCTP_DISPOSITION_DISCARD
;
5266 /************************************************************
5267 * These are the state functions for handling timeout events.
5268 ************************************************************/
5273 * Section: 6.3.3 Handle T3-rtx Expiration
5275 * Whenever the retransmission timer T3-rtx expires for a destination
5276 * address, do the following:
5279 * The return value is the disposition of the chunk.
5281 sctp_disposition_t
sctp_sf_do_6_3_3_rtx(const struct sctp_endpoint
*ep
,
5282 const struct sctp_association
*asoc
,
5283 const sctp_subtype_t type
,
5285 sctp_cmd_seq_t
*commands
)
5287 struct sctp_transport
*transport
= arg
;
5289 SCTP_INC_STATS(SCTP_MIB_T3_RTX_EXPIREDS
);
5291 if (asoc
->overall_error_count
>= asoc
->max_retrans
) {
5292 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5293 SCTP_ERROR(ETIMEDOUT
));
5294 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5295 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
5296 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5297 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
5298 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
5299 return SCTP_DISPOSITION_DELETE_TCB
;
5302 /* E1) For the destination address for which the timer
5303 * expires, adjust its ssthresh with rules defined in Section
5304 * 7.2.3 and set the cwnd <- MTU.
5307 /* E2) For the destination address for which the timer
5308 * expires, set RTO <- RTO * 2 ("back off the timer"). The
5309 * maximum value discussed in rule C7 above (RTO.max) may be
5310 * used to provide an upper bound to this doubling operation.
5313 /* E3) Determine how many of the earliest (i.e., lowest TSN)
5314 * outstanding DATA chunks for the address for which the
5315 * T3-rtx has expired will fit into a single packet, subject
5316 * to the MTU constraint for the path corresponding to the
5317 * destination transport address to which the retransmission
5318 * is being sent (this may be different from the address for
5319 * which the timer expires [see Section 6.4]). Call this
5320 * value K. Bundle and retransmit those K DATA chunks in a
5321 * single packet to the destination endpoint.
5323 * Note: Any DATA chunks that were sent to the address for
5324 * which the T3-rtx timer expired but did not fit in one MTU
5325 * (rule E3 above), should be marked for retransmission and
5326 * sent as soon as cwnd allows (normally when a SACK arrives).
5329 /* Do some failure management (Section 8.2). */
5330 sctp_add_cmd_sf(commands
, SCTP_CMD_STRIKE
, SCTP_TRANSPORT(transport
));
5332 /* NB: Rules E4 and F1 are implicit in R1. */
5333 sctp_add_cmd_sf(commands
, SCTP_CMD_RETRAN
, SCTP_TRANSPORT(transport
));
5335 return SCTP_DISPOSITION_CONSUME
;
5339 * Generate delayed SACK on timeout
5341 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
5343 * The guidelines on delayed acknowledgement algorithm specified in
5344 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
5345 * acknowledgement SHOULD be generated for at least every second packet
5346 * (not every second DATA chunk) received, and SHOULD be generated
5347 * within 200 ms of the arrival of any unacknowledged DATA chunk. In
5348 * some situations it may be beneficial for an SCTP transmitter to be
5349 * more conservative than the algorithms detailed in this document
5350 * allow. However, an SCTP transmitter MUST NOT be more aggressive than
5351 * the following algorithms allow.
5353 sctp_disposition_t
sctp_sf_do_6_2_sack(const struct sctp_endpoint
*ep
,
5354 const struct sctp_association
*asoc
,
5355 const sctp_subtype_t type
,
5357 sctp_cmd_seq_t
*commands
)
5359 SCTP_INC_STATS(SCTP_MIB_DELAY_SACK_EXPIREDS
);
5360 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_FORCE());
5361 return SCTP_DISPOSITION_CONSUME
;
5365 * sctp_sf_t1_init_timer_expire
5367 * Section: 4 Note: 2
5372 * RFC 2960 Section 4 Notes
5373 * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT
5374 * and re-start the T1-init timer without changing state. This MUST
5375 * be repeated up to 'Max.Init.Retransmits' times. After that, the
5376 * endpoint MUST abort the initialization process and report the
5377 * error to SCTP user.
5383 sctp_disposition_t
sctp_sf_t1_init_timer_expire(const struct sctp_endpoint
*ep
,
5384 const struct sctp_association
*asoc
,
5385 const sctp_subtype_t type
,
5387 sctp_cmd_seq_t
*commands
)
5389 struct sctp_chunk
*repl
= NULL
;
5390 struct sctp_bind_addr
*bp
;
5391 int attempts
= asoc
->init_err_counter
+ 1;
5393 SCTP_DEBUG_PRINTK("Timer T1 expired (INIT).\n");
5394 SCTP_INC_STATS(SCTP_MIB_T1_INIT_EXPIREDS
);
5396 if (attempts
<= asoc
->max_init_attempts
) {
5397 bp
= (struct sctp_bind_addr
*) &asoc
->base
.bind_addr
;
5398 repl
= sctp_make_init(asoc
, bp
, GFP_ATOMIC
, 0);
5400 return SCTP_DISPOSITION_NOMEM
;
5402 /* Choose transport for INIT. */
5403 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_CHOOSE_TRANSPORT
,
5406 /* Issue a sideeffect to do the needed accounting. */
5407 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_RESTART
,
5408 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
5410 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
5412 SCTP_DEBUG_PRINTK("Giving up on INIT, attempts: %d"
5413 " max_init_attempts: %d\n",
5414 attempts
, asoc
->max_init_attempts
);
5415 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5416 SCTP_ERROR(ETIMEDOUT
));
5417 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
5418 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5419 return SCTP_DISPOSITION_DELETE_TCB
;
5422 return SCTP_DISPOSITION_CONSUME
;
5426 * sctp_sf_t1_cookie_timer_expire
5428 * Section: 4 Note: 2
5433 * RFC 2960 Section 4 Notes
5434 * 3) If the T1-cookie timer expires, the endpoint MUST retransmit
5435 * COOKIE ECHO and re-start the T1-cookie timer without changing
5436 * state. This MUST be repeated up to 'Max.Init.Retransmits' times.
5437 * After that, the endpoint MUST abort the initialization process and
5438 * report the error to SCTP user.
5444 sctp_disposition_t
sctp_sf_t1_cookie_timer_expire(const struct sctp_endpoint
*ep
,
5445 const struct sctp_association
*asoc
,
5446 const sctp_subtype_t type
,
5448 sctp_cmd_seq_t
*commands
)
5450 struct sctp_chunk
*repl
= NULL
;
5451 int attempts
= asoc
->init_err_counter
+ 1;
5453 SCTP_DEBUG_PRINTK("Timer T1 expired (COOKIE-ECHO).\n");
5454 SCTP_INC_STATS(SCTP_MIB_T1_COOKIE_EXPIREDS
);
5456 if (attempts
<= asoc
->max_init_attempts
) {
5457 repl
= sctp_make_cookie_echo(asoc
, NULL
);
5459 return SCTP_DISPOSITION_NOMEM
;
5461 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_CHOOSE_TRANSPORT
,
5463 /* Issue a sideeffect to do the needed accounting. */
5464 sctp_add_cmd_sf(commands
, SCTP_CMD_COOKIEECHO_RESTART
,
5465 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
5467 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
5469 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5470 SCTP_ERROR(ETIMEDOUT
));
5471 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
5472 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5473 return SCTP_DISPOSITION_DELETE_TCB
;
5476 return SCTP_DISPOSITION_CONSUME
;
5479 /* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN
5480 * with the updated last sequential TSN received from its peer.
5482 * An endpoint should limit the number of retransmissions of the
5483 * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'.
5484 * If this threshold is exceeded the endpoint should destroy the TCB and
5485 * MUST report the peer endpoint unreachable to the upper layer (and
5486 * thus the association enters the CLOSED state). The reception of any
5487 * packet from its peer (i.e. as the peer sends all of its queued DATA
5488 * chunks) should clear the endpoint's retransmission count and restart
5489 * the T2-Shutdown timer, giving its peer ample opportunity to transmit
5490 * all of its queued DATA chunks that have not yet been sent.
5492 sctp_disposition_t
sctp_sf_t2_timer_expire(const struct sctp_endpoint
*ep
,
5493 const struct sctp_association
*asoc
,
5494 const sctp_subtype_t type
,
5496 sctp_cmd_seq_t
*commands
)
5498 struct sctp_chunk
*reply
= NULL
;
5500 SCTP_DEBUG_PRINTK("Timer T2 expired.\n");
5501 SCTP_INC_STATS(SCTP_MIB_T2_SHUTDOWN_EXPIREDS
);
5503 ((struct sctp_association
*)asoc
)->shutdown_retries
++;
5505 if (asoc
->overall_error_count
>= asoc
->max_retrans
) {
5506 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5507 SCTP_ERROR(ETIMEDOUT
));
5508 /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5509 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
5510 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5511 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
5512 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
5513 return SCTP_DISPOSITION_DELETE_TCB
;
5516 switch (asoc
->state
) {
5517 case SCTP_STATE_SHUTDOWN_SENT
:
5518 reply
= sctp_make_shutdown(asoc
, NULL
);
5521 case SCTP_STATE_SHUTDOWN_ACK_SENT
:
5522 reply
= sctp_make_shutdown_ack(asoc
, NULL
);
5533 /* Do some failure management (Section 8.2).
5534 * If we remove the transport an SHUTDOWN was last sent to, don't
5535 * do failure management.
5537 if (asoc
->shutdown_last_sent_to
)
5538 sctp_add_cmd_sf(commands
, SCTP_CMD_STRIKE
,
5539 SCTP_TRANSPORT(asoc
->shutdown_last_sent_to
));
5541 /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for
5542 * the T2-shutdown timer.
5544 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T2
, SCTP_CHUNK(reply
));
5546 /* Restart the T2-shutdown timer. */
5547 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
5548 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
5549 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
5550 return SCTP_DISPOSITION_CONSUME
;
5553 return SCTP_DISPOSITION_NOMEM
;
5557 * ADDIP Section 4.1 ASCONF CHunk Procedures
5558 * If the T4 RTO timer expires the endpoint should do B1 to B5
5560 sctp_disposition_t
sctp_sf_t4_timer_expire(
5561 const struct sctp_endpoint
*ep
,
5562 const struct sctp_association
*asoc
,
5563 const sctp_subtype_t type
,
5565 sctp_cmd_seq_t
*commands
)
5567 struct sctp_chunk
*chunk
= asoc
->addip_last_asconf
;
5568 struct sctp_transport
*transport
= chunk
->transport
;
5570 SCTP_INC_STATS(SCTP_MIB_T4_RTO_EXPIREDS
);
5572 /* ADDIP 4.1 B1) Increment the error counters and perform path failure
5573 * detection on the appropriate destination address as defined in
5574 * RFC2960 [5] section 8.1 and 8.2.
5577 sctp_add_cmd_sf(commands
, SCTP_CMD_STRIKE
,
5578 SCTP_TRANSPORT(transport
));
5580 /* Reconfig T4 timer and transport. */
5581 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T4
, SCTP_CHUNK(chunk
));
5583 /* ADDIP 4.1 B2) Increment the association error counters and perform
5584 * endpoint failure detection on the association as defined in
5585 * RFC2960 [5] section 8.1 and 8.2.
5586 * association error counter is incremented in SCTP_CMD_STRIKE.
5588 if (asoc
->overall_error_count
>= asoc
->max_retrans
) {
5589 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
5590 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
5591 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5592 SCTP_ERROR(ETIMEDOUT
));
5593 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
5594 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5595 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
5596 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
5597 return SCTP_DISPOSITION_ABORT
;
5600 /* ADDIP 4.1 B3) Back-off the destination address RTO value to which
5601 * the ASCONF chunk was sent by doubling the RTO timer value.
5602 * This is done in SCTP_CMD_STRIKE.
5605 /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible
5606 * choose an alternate destination address (please refer to RFC2960
5607 * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this
5608 * chunk, it MUST be the same (including its serial number) as the last
5611 sctp_chunk_hold(asoc
->addip_last_asconf
);
5612 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
5613 SCTP_CHUNK(asoc
->addip_last_asconf
));
5615 /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different
5616 * destination is selected, then the RTO used will be that of the new
5617 * destination address.
5619 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
5620 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
5622 return SCTP_DISPOSITION_CONSUME
;
5625 /* sctpimpguide-05 Section 2.12.2
5626 * The sender of the SHUTDOWN MAY also start an overall guard timer
5627 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5628 * At the expiration of this timer the sender SHOULD abort the association
5629 * by sending an ABORT chunk.
5631 sctp_disposition_t
sctp_sf_t5_timer_expire(const struct sctp_endpoint
*ep
,
5632 const struct sctp_association
*asoc
,
5633 const sctp_subtype_t type
,
5635 sctp_cmd_seq_t
*commands
)
5637 struct sctp_chunk
*reply
= NULL
;
5639 SCTP_DEBUG_PRINTK("Timer T5 expired.\n");
5640 SCTP_INC_STATS(SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS
);
5642 reply
= sctp_make_abort(asoc
, NULL
, 0);
5646 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
5647 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5648 SCTP_ERROR(ETIMEDOUT
));
5649 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
5650 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5652 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
5653 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
5655 return SCTP_DISPOSITION_DELETE_TCB
;
5657 return SCTP_DISPOSITION_NOMEM
;
5660 /* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires,
5661 * the association is automatically closed by starting the shutdown process.
5662 * The work that needs to be done is same as when SHUTDOWN is initiated by
5663 * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown().
5665 sctp_disposition_t
sctp_sf_autoclose_timer_expire(
5666 const struct sctp_endpoint
*ep
,
5667 const struct sctp_association
*asoc
,
5668 const sctp_subtype_t type
,
5670 sctp_cmd_seq_t
*commands
)
5674 SCTP_INC_STATS(SCTP_MIB_AUTOCLOSE_EXPIREDS
);
5676 /* From 9.2 Shutdown of an Association
5677 * Upon receipt of the SHUTDOWN primitive from its upper
5678 * layer, the endpoint enters SHUTDOWN-PENDING state and
5679 * remains there until all outstanding data has been
5680 * acknowledged by its peer. The endpoint accepts no new data
5681 * from its upper layer, but retransmits data to the far end
5682 * if necessary to fill gaps.
5684 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
5685 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING
));
5687 disposition
= SCTP_DISPOSITION_CONSUME
;
5688 if (sctp_outq_is_empty(&asoc
->outqueue
)) {
5689 disposition
= sctp_sf_do_9_2_start_shutdown(ep
, asoc
, type
,
5695 /*****************************************************************************
5696 * These are sa state functions which could apply to all types of events.
5697 ****************************************************************************/
5700 * This table entry is not implemented.
5703 * (endpoint, asoc, chunk)
5705 * The return value is the disposition of the chunk.
5707 sctp_disposition_t
sctp_sf_not_impl(const struct sctp_endpoint
*ep
,
5708 const struct sctp_association
*asoc
,
5709 const sctp_subtype_t type
,
5711 sctp_cmd_seq_t
*commands
)
5713 return SCTP_DISPOSITION_NOT_IMPL
;
5717 * This table entry represents a bug.
5720 * (endpoint, asoc, chunk)
5722 * The return value is the disposition of the chunk.
5724 sctp_disposition_t
sctp_sf_bug(const struct sctp_endpoint
*ep
,
5725 const struct sctp_association
*asoc
,
5726 const sctp_subtype_t type
,
5728 sctp_cmd_seq_t
*commands
)
5730 return SCTP_DISPOSITION_BUG
;
5734 * This table entry represents the firing of a timer in the wrong state.
5735 * Since timer deletion cannot be guaranteed a timer 'may' end up firing
5736 * when the association is in the wrong state. This event should
5737 * be ignored, so as to prevent any rearming of the timer.
5740 * (endpoint, asoc, chunk)
5742 * The return value is the disposition of the chunk.
5744 sctp_disposition_t
sctp_sf_timer_ignore(const struct sctp_endpoint
*ep
,
5745 const struct sctp_association
*asoc
,
5746 const sctp_subtype_t type
,
5748 sctp_cmd_seq_t
*commands
)
5750 SCTP_DEBUG_PRINTK("Timer %d ignored.\n", type
.chunk
);
5751 return SCTP_DISPOSITION_CONSUME
;
5754 /********************************************************************
5755 * 2nd Level Abstractions
5756 ********************************************************************/
5758 /* Pull the SACK chunk based on the SACK header. */
5759 static struct sctp_sackhdr
*sctp_sm_pull_sack(struct sctp_chunk
*chunk
)
5761 struct sctp_sackhdr
*sack
;
5766 /* Protect ourselves from reading too far into
5767 * the skb from a bogus sender.
5769 sack
= (struct sctp_sackhdr
*) chunk
->skb
->data
;
5771 num_blocks
= ntohs(sack
->num_gap_ack_blocks
);
5772 num_dup_tsns
= ntohs(sack
->num_dup_tsns
);
5773 len
= sizeof(struct sctp_sackhdr
);
5774 len
+= (num_blocks
+ num_dup_tsns
) * sizeof(__u32
);
5775 if (len
> chunk
->skb
->len
)
5778 skb_pull(chunk
->skb
, len
);
5783 /* Create an ABORT packet to be sent as a response, with the specified
5786 static struct sctp_packet
*sctp_abort_pkt_new(const struct sctp_endpoint
*ep
,
5787 const struct sctp_association
*asoc
,
5788 struct sctp_chunk
*chunk
,
5789 const void *payload
,
5792 struct sctp_packet
*packet
;
5793 struct sctp_chunk
*abort
;
5795 packet
= sctp_ootb_pkt_new(asoc
, chunk
);
5799 * The T bit will be set if the asoc is NULL.
5801 abort
= sctp_make_abort(asoc
, chunk
, paylen
);
5803 sctp_ootb_pkt_free(packet
);
5807 /* Reflect vtag if T-Bit is set */
5808 if (sctp_test_T_bit(abort
))
5809 packet
->vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
5811 /* Add specified error causes, i.e., payload, to the
5814 sctp_addto_chunk(abort
, paylen
, payload
);
5816 /* Set the skb to the belonging sock for accounting. */
5817 abort
->skb
->sk
= ep
->base
.sk
;
5819 sctp_packet_append_chunk(packet
, abort
);
5826 /* Allocate a packet for responding in the OOTB conditions. */
5827 static struct sctp_packet
*sctp_ootb_pkt_new(const struct sctp_association
*asoc
,
5828 const struct sctp_chunk
*chunk
)
5830 struct sctp_packet
*packet
;
5831 struct sctp_transport
*transport
;
5836 /* Get the source and destination port from the inbound packet. */
5837 sport
= ntohs(chunk
->sctp_hdr
->dest
);
5838 dport
= ntohs(chunk
->sctp_hdr
->source
);
5840 /* The V-tag is going to be the same as the inbound packet if no
5841 * association exists, otherwise, use the peer's vtag.
5844 /* Special case the INIT-ACK as there is no peer's vtag
5847 switch(chunk
->chunk_hdr
->type
) {
5848 case SCTP_CID_INIT_ACK
:
5850 sctp_initack_chunk_t
*initack
;
5852 initack
= (sctp_initack_chunk_t
*)chunk
->chunk_hdr
;
5853 vtag
= ntohl(initack
->init_hdr
.init_tag
);
5857 vtag
= asoc
->peer
.i
.init_tag
;
5861 /* Special case the INIT and stale COOKIE_ECHO as there is no
5864 switch(chunk
->chunk_hdr
->type
) {
5867 sctp_init_chunk_t
*init
;
5869 init
= (sctp_init_chunk_t
*)chunk
->chunk_hdr
;
5870 vtag
= ntohl(init
->init_hdr
.init_tag
);
5874 vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
5879 /* Make a transport for the bucket, Eliza... */
5880 transport
= sctp_transport_new(sctp_source(chunk
), GFP_ATOMIC
);
5884 /* Cache a route for the transport with the chunk's destination as
5885 * the source address.
5887 sctp_transport_route(transport
, (union sctp_addr
*)&chunk
->dest
,
5888 sctp_sk(sctp_get_ctl_sock()));
5890 packet
= sctp_packet_init(&transport
->packet
, transport
, sport
, dport
);
5891 packet
= sctp_packet_config(packet
, vtag
, 0);
5899 /* Free the packet allocated earlier for responding in the OOTB condition. */
5900 void sctp_ootb_pkt_free(struct sctp_packet
*packet
)
5902 sctp_transport_free(packet
->transport
);
5905 /* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */
5906 static void sctp_send_stale_cookie_err(const struct sctp_endpoint
*ep
,
5907 const struct sctp_association
*asoc
,
5908 const struct sctp_chunk
*chunk
,
5909 sctp_cmd_seq_t
*commands
,
5910 struct sctp_chunk
*err_chunk
)
5912 struct sctp_packet
*packet
;
5915 packet
= sctp_ootb_pkt_new(asoc
, chunk
);
5917 struct sctp_signed_cookie
*cookie
;
5919 /* Override the OOTB vtag from the cookie. */
5920 cookie
= chunk
->subh
.cookie_hdr
;
5921 packet
->vtag
= cookie
->c
.peer_vtag
;
5923 /* Set the skb to the belonging sock for accounting. */
5924 err_chunk
->skb
->sk
= ep
->base
.sk
;
5925 sctp_packet_append_chunk(packet
, err_chunk
);
5926 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
5927 SCTP_PACKET(packet
));
5928 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
5930 sctp_chunk_free (err_chunk
);
5935 /* Process a data chunk */
5936 static int sctp_eat_data(const struct sctp_association
*asoc
,
5937 struct sctp_chunk
*chunk
,
5938 sctp_cmd_seq_t
*commands
)
5940 sctp_datahdr_t
*data_hdr
;
5941 struct sctp_chunk
*err
;
5943 sctp_verb_t deliver
;
5946 struct sctp_tsnmap
*map
= (struct sctp_tsnmap
*)&asoc
->peer
.tsn_map
;
5947 struct sock
*sk
= asoc
->base
.sk
;
5952 data_hdr
= chunk
->subh
.data_hdr
= (sctp_datahdr_t
*)chunk
->skb
->data
;
5953 skb_pull(chunk
->skb
, sizeof(sctp_datahdr_t
));
5955 tsn
= ntohl(data_hdr
->tsn
);
5956 SCTP_DEBUG_PRINTK("eat_data: TSN 0x%x.\n", tsn
);
5958 /* ASSERT: Now skb->data is really the user data. */
5960 /* Process ECN based congestion.
5962 * Since the chunk structure is reused for all chunks within
5963 * a packet, we use ecn_ce_done to track if we've already
5964 * done CE processing for this packet.
5966 * We need to do ECN processing even if we plan to discard the
5970 if (!chunk
->ecn_ce_done
) {
5972 chunk
->ecn_ce_done
= 1;
5974 af
= sctp_get_af_specific(
5975 ipver2af(ip_hdr(chunk
->skb
)->version
));
5977 if (af
&& af
->is_ce(chunk
->skb
) && asoc
->peer
.ecn_capable
) {
5978 /* Do real work as sideffect. */
5979 sctp_add_cmd_sf(commands
, SCTP_CMD_ECN_CE
,
5984 tmp
= sctp_tsnmap_check(&asoc
->peer
.tsn_map
, tsn
);
5986 /* The TSN is too high--silently discard the chunk and
5987 * count on it getting retransmitted later.
5989 return SCTP_IERROR_HIGH_TSN
;
5990 } else if (tmp
> 0) {
5991 /* This is a duplicate. Record it. */
5992 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_DUP
, SCTP_U32(tsn
));
5993 return SCTP_IERROR_DUP_TSN
;
5996 /* This is a new TSN. */
5998 /* Discard if there is no room in the receive window.
5999 * Actually, allow a little bit of overflow (up to a MTU).
6001 datalen
= ntohs(chunk
->chunk_hdr
->length
);
6002 datalen
-= sizeof(sctp_data_chunk_t
);
6004 deliver
= SCTP_CMD_CHUNK_ULP
;
6006 /* Think about partial delivery. */
6007 if ((datalen
>= asoc
->rwnd
) && (!asoc
->ulpq
.pd_mode
)) {
6009 /* Even if we don't accept this chunk there is
6012 sctp_add_cmd_sf(commands
, SCTP_CMD_PART_DELIVER
, SCTP_NULL());
6015 /* Spill over rwnd a little bit. Note: While allowed, this spill over
6016 * seems a bit troublesome in that frag_point varies based on
6017 * PMTU. In cases, such as loopback, this might be a rather
6020 if ((!chunk
->data_accepted
) && (!asoc
->rwnd
|| asoc
->rwnd_over
||
6021 (datalen
> asoc
->rwnd
+ asoc
->frag_point
))) {
6023 /* If this is the next TSN, consider reneging to make
6024 * room. Note: Playing nice with a confused sender. A
6025 * malicious sender can still eat up all our buffer
6026 * space and in the future we may want to detect and
6027 * do more drastic reneging.
6029 if (sctp_tsnmap_has_gap(map
) &&
6030 (sctp_tsnmap_get_ctsn(map
) + 1) == tsn
) {
6031 SCTP_DEBUG_PRINTK("Reneging for tsn:%u\n", tsn
);
6032 deliver
= SCTP_CMD_RENEGE
;
6034 SCTP_DEBUG_PRINTK("Discard tsn: %u len: %Zd, "
6035 "rwnd: %d\n", tsn
, datalen
,
6037 return SCTP_IERROR_IGNORE_TSN
;
6042 * Also try to renege to limit our memory usage in the event that
6043 * we are under memory pressure
6044 * If we can't renege, don't worry about it, the sk_rmem_schedule
6045 * in sctp_ulpevent_make_rcvmsg will drop the frame if we grow our
6046 * memory usage too much
6048 if (*sk
->sk_prot_creator
->memory_pressure
) {
6049 if (sctp_tsnmap_has_gap(map
) &&
6050 (sctp_tsnmap_get_ctsn(map
) + 1) == tsn
) {
6051 SCTP_DEBUG_PRINTK("Under Pressure! Reneging for tsn:%u\n", tsn
);
6052 deliver
= SCTP_CMD_RENEGE
;
6057 * Section 3.3.10.9 No User Data (9)
6061 * No User Data: This error cause is returned to the originator of a
6062 * DATA chunk if a received DATA chunk has no user data.
6064 if (unlikely(0 == datalen
)) {
6065 err
= sctp_make_abort_no_data(asoc
, chunk
, tsn
);
6067 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
6070 /* We are going to ABORT, so we might as well stop
6071 * processing the rest of the chunks in the packet.
6073 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
,SCTP_NULL());
6074 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
6075 SCTP_ERROR(ECONNABORTED
));
6076 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
6077 SCTP_PERR(SCTP_ERROR_NO_DATA
));
6078 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
6079 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
6080 return SCTP_IERROR_NO_DATA
;
6083 chunk
->data_accepted
= 1;
6085 /* Note: Some chunks may get overcounted (if we drop) or overcounted
6086 * if we renege and the chunk arrives again.
6088 if (chunk
->chunk_hdr
->flags
& SCTP_DATA_UNORDERED
)
6089 SCTP_INC_STATS(SCTP_MIB_INUNORDERCHUNKS
);
6091 SCTP_INC_STATS(SCTP_MIB_INORDERCHUNKS
);
6095 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
6097 * If an endpoint receive a DATA chunk with an invalid stream
6098 * identifier, it shall acknowledge the reception of the DATA chunk
6099 * following the normal procedure, immediately send an ERROR chunk
6100 * with cause set to "Invalid Stream Identifier" (See Section 3.3.10)
6101 * and discard the DATA chunk.
6103 sid
= ntohs(data_hdr
->stream
);
6104 if (sid
>= asoc
->c
.sinit_max_instreams
) {
6105 /* Mark tsn as received even though we drop it */
6106 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_TSN
, SCTP_U32(tsn
));
6108 err
= sctp_make_op_error(asoc
, chunk
, SCTP_ERROR_INV_STRM
,
6110 sizeof(data_hdr
->stream
),
6113 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
6115 return SCTP_IERROR_BAD_STREAM
;
6118 /* Check to see if the SSN is possible for this TSN.
6119 * The biggest gap we can record is 4K wide. Since SSNs wrap
6120 * at an unsigned short, there is no way that an SSN can
6121 * wrap and for a valid TSN. We can simply check if the current
6122 * SSN is smaller then the next expected one. If it is, it wrapped
6125 ssn
= ntohs(data_hdr
->ssn
);
6126 if (ordered
&& SSN_lt(ssn
, sctp_ssn_peek(&asoc
->ssnmap
->in
, sid
))) {
6127 return SCTP_IERROR_PROTO_VIOLATION
;
6130 /* Send the data up to the user. Note: Schedule the
6131 * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK
6132 * chunk needs the updated rwnd.
6134 sctp_add_cmd_sf(commands
, deliver
, SCTP_CHUNK(chunk
));
6136 return SCTP_IERROR_NO_ERROR
;