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 #include <linux/types.h>
54 #include <linux/kernel.h>
56 #include <linux/ipv6.h>
57 #include <linux/net.h>
58 #include <linux/inet.h>
60 #include <net/inet_ecn.h>
61 #include <linux/skbuff.h>
62 #include <net/sctp/sctp.h>
63 #include <net/sctp/sm.h>
64 #include <net/sctp/structs.h>
66 static struct sctp_packet
*sctp_abort_pkt_new(const struct sctp_endpoint
*ep
,
67 const struct sctp_association
*asoc
,
68 struct sctp_chunk
*chunk
,
71 static int sctp_eat_data(const struct sctp_association
*asoc
,
72 struct sctp_chunk
*chunk
,
73 sctp_cmd_seq_t
*commands
);
74 static struct sctp_packet
*sctp_ootb_pkt_new(const struct sctp_association
*asoc
,
75 const struct sctp_chunk
*chunk
);
76 static void sctp_send_stale_cookie_err(const struct sctp_endpoint
*ep
,
77 const struct sctp_association
*asoc
,
78 const struct sctp_chunk
*chunk
,
79 sctp_cmd_seq_t
*commands
,
80 struct sctp_chunk
*err_chunk
);
81 static sctp_disposition_t
sctp_sf_do_5_2_6_stale(const struct sctp_endpoint
*ep
,
82 const struct sctp_association
*asoc
,
83 const sctp_subtype_t type
,
85 sctp_cmd_seq_t
*commands
);
86 static sctp_disposition_t
sctp_sf_shut_8_4_5(const struct sctp_endpoint
*ep
,
87 const struct sctp_association
*asoc
,
88 const sctp_subtype_t type
,
90 sctp_cmd_seq_t
*commands
);
91 static sctp_disposition_t
sctp_sf_tabort_8_4_8(const struct sctp_endpoint
*ep
,
92 const struct sctp_association
*asoc
,
93 const sctp_subtype_t type
,
95 sctp_cmd_seq_t
*commands
);
96 static struct sctp_sackhdr
*sctp_sm_pull_sack(struct sctp_chunk
*chunk
);
98 static sctp_disposition_t
sctp_stop_t1_and_abort(sctp_cmd_seq_t
*commands
,
99 __be16 error
, int sk_err
,
100 const struct sctp_association
*asoc
,
101 struct sctp_transport
*transport
);
103 static sctp_disposition_t
sctp_sf_abort_violation(
104 const struct sctp_endpoint
*ep
,
105 const struct sctp_association
*asoc
,
107 sctp_cmd_seq_t
*commands
,
109 const size_t paylen
);
111 static sctp_disposition_t
sctp_sf_violation_chunklen(
112 const struct sctp_endpoint
*ep
,
113 const struct sctp_association
*asoc
,
114 const sctp_subtype_t type
,
116 sctp_cmd_seq_t
*commands
);
118 static sctp_disposition_t
sctp_sf_violation_paramlen(
119 const struct sctp_endpoint
*ep
,
120 const struct sctp_association
*asoc
,
121 const sctp_subtype_t type
,
122 void *arg
, void *ext
,
123 sctp_cmd_seq_t
*commands
);
125 static sctp_disposition_t
sctp_sf_violation_ctsn(
126 const struct sctp_endpoint
*ep
,
127 const struct sctp_association
*asoc
,
128 const sctp_subtype_t type
,
130 sctp_cmd_seq_t
*commands
);
132 static sctp_disposition_t
sctp_sf_violation_chunk(
133 const struct sctp_endpoint
*ep
,
134 const struct sctp_association
*asoc
,
135 const sctp_subtype_t type
,
137 sctp_cmd_seq_t
*commands
);
139 static sctp_ierror_t
sctp_sf_authenticate(const struct sctp_endpoint
*ep
,
140 const struct sctp_association
*asoc
,
141 const sctp_subtype_t type
,
142 struct sctp_chunk
*chunk
);
144 static sctp_disposition_t
__sctp_sf_do_9_1_abort(const struct sctp_endpoint
*ep
,
145 const struct sctp_association
*asoc
,
146 const sctp_subtype_t type
,
148 sctp_cmd_seq_t
*commands
);
150 /* Small helper function that checks if the chunk length
151 * is of the appropriate length. The 'required_length' argument
152 * is set to be the size of a specific chunk we are testing.
153 * Return Values: 1 = Valid length
158 sctp_chunk_length_valid(struct sctp_chunk
*chunk
,
159 __u16 required_length
)
161 __u16 chunk_length
= ntohs(chunk
->chunk_hdr
->length
);
163 if (unlikely(chunk_length
< required_length
))
169 /**********************************************************
170 * These are the state functions for handling chunk events.
171 **********************************************************/
174 * Process the final SHUTDOWN COMPLETE.
176 * Section: 4 (C) (diagram), 9.2
177 * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify
178 * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be
179 * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint
180 * should stop the T2-shutdown timer and remove all knowledge of the
181 * association (and thus the association enters the CLOSED state).
183 * Verification Tag: 8.5.1(C), sctpimpguide 2.41.
184 * C) Rules for packet carrying SHUTDOWN COMPLETE:
186 * - The receiver of a SHUTDOWN COMPLETE shall accept the packet
187 * if the Verification Tag field of the packet matches its own tag and
188 * the T bit is not set
190 * it is set to its peer's tag and the T bit is set in the Chunk
192 * Otherwise, the receiver MUST silently discard the packet
193 * and take no further action. An endpoint MUST ignore the
194 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
197 * (endpoint, asoc, chunk)
200 * (asoc, reply_msg, msg_up, timers, counters)
202 * The return value is the disposition of the chunk.
204 sctp_disposition_t
sctp_sf_do_4_C(const struct sctp_endpoint
*ep
,
205 const struct sctp_association
*asoc
,
206 const sctp_subtype_t type
,
208 sctp_cmd_seq_t
*commands
)
210 struct sctp_chunk
*chunk
= arg
;
211 struct sctp_ulpevent
*ev
;
213 if (!sctp_vtag_verify_either(chunk
, asoc
))
214 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
216 /* RFC 2960 6.10 Bundling
218 * An endpoint MUST NOT bundle INIT, INIT ACK or
219 * SHUTDOWN COMPLETE with any other chunks.
221 if (!chunk
->singleton
)
222 return sctp_sf_violation_chunk(ep
, asoc
, type
, arg
, commands
);
224 /* Make sure that the SHUTDOWN_COMPLETE chunk has a valid length. */
225 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
226 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
229 /* RFC 2960 10.2 SCTP-to-ULP
231 * H) SHUTDOWN COMPLETE notification
233 * When SCTP completes the shutdown procedures (section 9.2) this
234 * notification is passed to the upper layer.
236 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_SHUTDOWN_COMP
,
237 0, 0, 0, NULL
, GFP_ATOMIC
);
239 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
242 /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint
243 * will verify that it is in SHUTDOWN-ACK-SENT state, if it is
244 * not the chunk should be discarded. If the endpoint is in
245 * the SHUTDOWN-ACK-SENT state the endpoint should stop the
246 * T2-shutdown timer and remove all knowledge of the
247 * association (and thus the association enters the CLOSED
250 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
251 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
253 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
254 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
256 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
257 SCTP_STATE(SCTP_STATE_CLOSED
));
259 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS
);
260 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
262 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
264 return SCTP_DISPOSITION_DELETE_TCB
;
268 * Respond to a normal INIT chunk.
269 * We are the side that is being asked for an association.
271 * Section: 5.1 Normal Establishment of an Association, B
272 * B) "Z" shall respond immediately with an INIT ACK chunk. The
273 * destination IP address of the INIT ACK MUST be set to the source
274 * IP address of the INIT to which this INIT ACK is responding. In
275 * the response, besides filling in other parameters, "Z" must set the
276 * Verification Tag field to Tag_A, and also provide its own
277 * Verification Tag (Tag_Z) in the Initiate Tag field.
279 * Verification Tag: Must be 0.
282 * (endpoint, asoc, chunk)
285 * (asoc, reply_msg, msg_up, timers, counters)
287 * The return value is the disposition of the chunk.
289 sctp_disposition_t
sctp_sf_do_5_1B_init(const struct sctp_endpoint
*ep
,
290 const struct sctp_association
*asoc
,
291 const sctp_subtype_t type
,
293 sctp_cmd_seq_t
*commands
)
295 struct sctp_chunk
*chunk
= arg
;
296 struct sctp_chunk
*repl
;
297 struct sctp_association
*new_asoc
;
298 struct sctp_chunk
*err_chunk
;
299 struct sctp_packet
*packet
;
300 sctp_unrecognized_param_t
*unk_param
;
304 * An endpoint MUST NOT bundle INIT, INIT ACK or
305 * SHUTDOWN COMPLETE with any other chunks.
308 * Furthermore, we require that the receiver of an INIT chunk MUST
309 * enforce these rules by silently discarding an arriving packet
310 * with an INIT chunk that is bundled with other chunks.
312 if (!chunk
->singleton
)
313 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
315 /* If the packet is an OOTB packet which is temporarily on the
316 * control endpoint, respond with an ABORT.
318 if (ep
== sctp_sk((sctp_get_ctl_sock()))->ep
)
319 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
, commands
);
321 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
324 if (chunk
->sctp_hdr
->vtag
!= 0)
325 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
, commands
);
327 /* Make sure that the INIT chunk has a valid length.
328 * Normally, this would cause an ABORT with a Protocol Violation
329 * error, but since we don't have an association, we'll
330 * just discard the packet.
332 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_init_chunk_t
)))
333 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
335 /* Verify the INIT chunk before processing it. */
337 if (!sctp_verify_init(asoc
, chunk
->chunk_hdr
->type
,
338 (sctp_init_chunk_t
*)chunk
->chunk_hdr
, chunk
,
340 /* This chunk contains fatal error. It is to be discarded.
341 * Send an ABORT, with causes if there is any.
344 packet
= sctp_abort_pkt_new(ep
, asoc
, arg
,
345 (__u8
*)(err_chunk
->chunk_hdr
) +
346 sizeof(sctp_chunkhdr_t
),
347 ntohs(err_chunk
->chunk_hdr
->length
) -
348 sizeof(sctp_chunkhdr_t
));
350 sctp_chunk_free(err_chunk
);
353 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
354 SCTP_PACKET(packet
));
355 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
356 return SCTP_DISPOSITION_CONSUME
;
358 return SCTP_DISPOSITION_NOMEM
;
361 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
,
366 /* Grab the INIT header. */
367 chunk
->subh
.init_hdr
= (sctp_inithdr_t
*)chunk
->skb
->data
;
369 /* Tag the variable length parameters. */
370 chunk
->param_hdr
.v
= skb_pull(chunk
->skb
, sizeof(sctp_inithdr_t
));
372 new_asoc
= sctp_make_temp_asoc(ep
, chunk
, GFP_ATOMIC
);
376 /* The call, sctp_process_init(), can fail on memory allocation. */
377 if (!sctp_process_init(new_asoc
, chunk
->chunk_hdr
->type
,
379 (sctp_init_chunk_t
*)chunk
->chunk_hdr
,
383 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
385 /* If there are errors need to be reported for unknown parameters,
386 * make sure to reserve enough room in the INIT ACK for them.
390 len
= ntohs(err_chunk
->chunk_hdr
->length
) -
391 sizeof(sctp_chunkhdr_t
);
393 if (sctp_assoc_set_bind_addr_from_ep(new_asoc
, GFP_ATOMIC
) < 0)
396 repl
= sctp_make_init_ack(new_asoc
, chunk
, GFP_ATOMIC
, len
);
400 /* If there are errors need to be reported for unknown parameters,
401 * include them in the outgoing INIT ACK as "Unrecognized parameter"
405 /* Get the "Unrecognized parameter" parameter(s) out of the
406 * ERROR chunk generated by sctp_verify_init(). Since the
407 * error cause code for "unknown parameter" and the
408 * "Unrecognized parameter" type is the same, we can
409 * construct the parameters in INIT ACK by copying the
412 unk_param
= (sctp_unrecognized_param_t
*)
413 ((__u8
*)(err_chunk
->chunk_hdr
) +
414 sizeof(sctp_chunkhdr_t
));
415 /* Replace the cause code with the "Unrecognized parameter"
418 sctp_addto_chunk(repl
, len
, unk_param
);
419 sctp_chunk_free(err_chunk
);
422 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(new_asoc
));
424 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
427 * Note: After sending out INIT ACK with the State Cookie parameter,
428 * "Z" MUST NOT allocate any resources, nor keep any states for the
429 * new association. Otherwise, "Z" will be vulnerable to resource
432 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
434 return SCTP_DISPOSITION_DELETE_TCB
;
437 sctp_association_free(new_asoc
);
440 sctp_chunk_free(err_chunk
);
441 return SCTP_DISPOSITION_NOMEM
;
445 * Respond to a normal INIT ACK chunk.
446 * We are the side that is initiating the association.
448 * Section: 5.1 Normal Establishment of an Association, C
449 * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init
450 * timer and leave COOKIE-WAIT state. "A" shall then send the State
451 * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start
452 * the T1-cookie timer, and enter the COOKIE-ECHOED state.
454 * Note: The COOKIE ECHO chunk can be bundled with any pending outbound
455 * DATA chunks, but it MUST be the first chunk in the packet and
456 * until the COOKIE ACK is returned the sender MUST NOT send any
457 * other packets to the peer.
459 * Verification Tag: 3.3.3
460 * If the value of the Initiate Tag in a received INIT ACK chunk is
461 * found to be 0, the receiver MUST treat it as an error and close the
462 * association by transmitting an ABORT.
465 * (endpoint, asoc, chunk)
468 * (asoc, reply_msg, msg_up, timers, counters)
470 * The return value is the disposition of the chunk.
472 sctp_disposition_t
sctp_sf_do_5_1C_ack(const struct sctp_endpoint
*ep
,
473 const struct sctp_association
*asoc
,
474 const sctp_subtype_t type
,
476 sctp_cmd_seq_t
*commands
)
478 struct sctp_chunk
*chunk
= arg
;
479 sctp_init_chunk_t
*initchunk
;
480 struct sctp_chunk
*err_chunk
;
481 struct sctp_packet
*packet
;
483 if (!sctp_vtag_verify(chunk
, asoc
))
484 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
487 * An endpoint MUST NOT bundle INIT, INIT ACK or
488 * SHUTDOWN COMPLETE with any other chunks.
490 if (!chunk
->singleton
)
491 return sctp_sf_violation_chunk(ep
, asoc
, type
, arg
, commands
);
493 /* Make sure that the INIT-ACK chunk has a valid length */
494 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_initack_chunk_t
)))
495 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
497 /* Grab the INIT header. */
498 chunk
->subh
.init_hdr
= (sctp_inithdr_t
*) chunk
->skb
->data
;
500 /* Verify the INIT chunk before processing it. */
502 if (!sctp_verify_init(asoc
, chunk
->chunk_hdr
->type
,
503 (sctp_init_chunk_t
*)chunk
->chunk_hdr
, chunk
,
506 sctp_error_t error
= SCTP_ERROR_NO_RESOURCE
;
508 /* This chunk contains fatal error. It is to be discarded.
509 * Send an ABORT, with causes. If there are no causes,
510 * then there wasn't enough memory. Just terminate
514 packet
= sctp_abort_pkt_new(ep
, asoc
, arg
,
515 (__u8
*)(err_chunk
->chunk_hdr
) +
516 sizeof(sctp_chunkhdr_t
),
517 ntohs(err_chunk
->chunk_hdr
->length
) -
518 sizeof(sctp_chunkhdr_t
));
520 sctp_chunk_free(err_chunk
);
523 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
524 SCTP_PACKET(packet
));
525 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
526 error
= SCTP_ERROR_INV_PARAM
;
530 /* SCTP-AUTH, Section 6.3:
531 * It should be noted that if the receiver wants to tear
532 * down an association in an authenticated way only, the
533 * handling of malformed packets should not result in
534 * tearing down the association.
536 * This means that if we only want to abort associations
537 * in an authenticated way (i.e AUTH+ABORT), then we
538 * can't destroy this association just becuase the packet
541 if (sctp_auth_recv_cid(SCTP_CID_ABORT
, asoc
))
542 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
544 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
545 return sctp_stop_t1_and_abort(commands
, error
, ECONNREFUSED
,
546 asoc
, chunk
->transport
);
549 /* Tag the variable length parameters. Note that we never
550 * convert the parameters in an INIT chunk.
552 chunk
->param_hdr
.v
= skb_pull(chunk
->skb
, sizeof(sctp_inithdr_t
));
554 initchunk
= (sctp_init_chunk_t
*) chunk
->chunk_hdr
;
556 sctp_add_cmd_sf(commands
, SCTP_CMD_PEER_INIT
,
557 SCTP_PEER_INIT(initchunk
));
559 /* Reset init error count upon receipt of INIT-ACK. */
560 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_COUNTER_RESET
, SCTP_NULL());
562 /* 5.1 C) "A" shall stop the T1-init timer and leave
563 * COOKIE-WAIT state. "A" shall then ... start the T1-cookie
564 * timer, and enter the COOKIE-ECHOED state.
566 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
567 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
568 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
569 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
570 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
571 SCTP_STATE(SCTP_STATE_COOKIE_ECHOED
));
573 /* SCTP-AUTH: genereate the assocition shared keys so that
574 * we can potentially signe the COOKIE-ECHO.
576 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_SHKEY
, SCTP_NULL());
578 /* 5.1 C) "A" shall then send the State Cookie received in the
579 * INIT ACK chunk in a COOKIE ECHO chunk, ...
581 /* If there is any errors to report, send the ERROR chunk generated
582 * for unknown parameters as well.
584 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_COOKIE_ECHO
,
585 SCTP_CHUNK(err_chunk
));
587 return SCTP_DISPOSITION_CONSUME
;
591 * Respond to a normal COOKIE ECHO chunk.
592 * We are the side that is being asked for an association.
594 * Section: 5.1 Normal Establishment of an Association, D
595 * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply
596 * with a COOKIE ACK chunk after building a TCB and moving to
597 * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with
598 * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK
599 * chunk MUST be the first chunk in the packet.
601 * IMPLEMENTATION NOTE: An implementation may choose to send the
602 * Communication Up notification to the SCTP user upon reception
603 * of a valid COOKIE ECHO chunk.
605 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
606 * D) Rules for packet carrying a COOKIE ECHO
608 * - When sending a COOKIE ECHO, the endpoint MUST use the value of the
609 * Initial Tag received in the INIT ACK.
611 * - The receiver of a COOKIE ECHO follows the procedures in Section 5.
614 * (endpoint, asoc, chunk)
617 * (asoc, reply_msg, msg_up, timers, counters)
619 * The return value is the disposition of the chunk.
621 sctp_disposition_t
sctp_sf_do_5_1D_ce(const struct sctp_endpoint
*ep
,
622 const struct sctp_association
*asoc
,
623 const sctp_subtype_t type
, void *arg
,
624 sctp_cmd_seq_t
*commands
)
626 struct sctp_chunk
*chunk
= arg
;
627 struct sctp_association
*new_asoc
;
628 sctp_init_chunk_t
*peer_init
;
629 struct sctp_chunk
*repl
;
630 struct sctp_ulpevent
*ev
, *ai_ev
= NULL
;
632 struct sctp_chunk
*err_chk_p
;
635 /* If the packet is an OOTB packet which is temporarily on the
636 * control endpoint, respond with an ABORT.
638 if (ep
== sctp_sk((sctp_get_ctl_sock()))->ep
)
639 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
, commands
);
641 /* Make sure that the COOKIE_ECHO chunk has a valid length.
642 * In this case, we check that we have enough for at least a
643 * chunk header. More detailed verification is done
644 * in sctp_unpack_cookie().
646 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
647 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
649 /* If the endpoint is not listening or if the number of associations
650 * on the TCP-style socket exceed the max backlog, respond with an
654 if (!sctp_sstate(sk
, LISTENING
) ||
655 (sctp_style(sk
, TCP
) && sk_acceptq_is_full(sk
)))
656 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
, commands
);
658 /* "Decode" the chunk. We have no optional parameters so we
661 chunk
->subh
.cookie_hdr
=
662 (struct sctp_signed_cookie
*)chunk
->skb
->data
;
663 if (!pskb_pull(chunk
->skb
, ntohs(chunk
->chunk_hdr
->length
) -
664 sizeof(sctp_chunkhdr_t
)))
667 /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
668 * "Z" will reply with a COOKIE ACK chunk after building a TCB
669 * and moving to the ESTABLISHED state.
671 new_asoc
= sctp_unpack_cookie(ep
, asoc
, chunk
, GFP_ATOMIC
, &error
,
675 * If the re-build failed, what is the proper error path
678 * [We should abort the association. --piggy]
681 /* FIXME: Several errors are possible. A bad cookie should
682 * be silently discarded, but think about logging it too.
685 case -SCTP_IERROR_NOMEM
:
688 case -SCTP_IERROR_STALE_COOKIE
:
689 sctp_send_stale_cookie_err(ep
, asoc
, chunk
, commands
,
691 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
693 case -SCTP_IERROR_BAD_SIG
:
695 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
700 /* Delay state machine commands until later.
702 * Re-build the bind address for the association is done in
703 * the sctp_unpack_cookie() already.
705 /* This is a brand-new association, so these are not yet side
706 * effects--it is safe to run them here.
708 peer_init
= &chunk
->subh
.cookie_hdr
->c
.peer_init
[0];
710 if (!sctp_process_init(new_asoc
, chunk
->chunk_hdr
->type
,
711 &chunk
->subh
.cookie_hdr
->c
.peer_addr
,
712 peer_init
, GFP_ATOMIC
))
715 /* SCTP-AUTH: Now that we've populate required fields in
716 * sctp_process_init, set up the assocaition shared keys as
717 * necessary so that we can potentially authenticate the ACK
719 error
= sctp_auth_asoc_init_active_key(new_asoc
, GFP_ATOMIC
);
723 /* SCTP-AUTH: auth_chunk pointer is only set when the cookie-echo
724 * is supposed to be authenticated and we have to do delayed
725 * authentication. We've just recreated the association using
726 * the information in the cookie and now it's much easier to
727 * do the authentication.
729 if (chunk
->auth_chunk
) {
730 struct sctp_chunk auth
;
733 /* set-up our fake chunk so that we can process it */
734 auth
.skb
= chunk
->auth_chunk
;
735 auth
.asoc
= chunk
->asoc
;
736 auth
.sctp_hdr
= chunk
->sctp_hdr
;
737 auth
.chunk_hdr
= (sctp_chunkhdr_t
*)skb_push(chunk
->auth_chunk
,
738 sizeof(sctp_chunkhdr_t
));
739 skb_pull(chunk
->auth_chunk
, sizeof(sctp_chunkhdr_t
));
740 auth
.transport
= chunk
->transport
;
742 ret
= sctp_sf_authenticate(ep
, new_asoc
, type
, &auth
);
744 /* We can now safely free the auth_chunk clone */
745 kfree_skb(chunk
->auth_chunk
);
747 if (ret
!= SCTP_IERROR_NO_ERROR
) {
748 sctp_association_free(new_asoc
);
749 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
753 repl
= sctp_make_cookie_ack(new_asoc
, chunk
);
757 /* RFC 2960 5.1 Normal Establishment of an Association
759 * D) IMPLEMENTATION NOTE: An implementation may choose to
760 * send the Communication Up notification to the SCTP user
761 * upon reception of a valid COOKIE ECHO chunk.
763 ev
= sctp_ulpevent_make_assoc_change(new_asoc
, 0, SCTP_COMM_UP
, 0,
764 new_asoc
->c
.sinit_num_ostreams
,
765 new_asoc
->c
.sinit_max_instreams
,
770 /* Sockets API Draft Section 5.3.1.6
771 * When a peer sends a Adaptation Layer Indication parameter , SCTP
772 * delivers this notification to inform the application that of the
773 * peers requested adaptation layer.
775 if (new_asoc
->peer
.adaptation_ind
) {
776 ai_ev
= sctp_ulpevent_make_adaptation_indication(new_asoc
,
782 /* Add all the state machine commands now since we've created
783 * everything. This way we don't introduce memory corruptions
784 * during side-effect processing and correclty count established
787 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(new_asoc
));
788 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
789 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
790 SCTP_INC_STATS(SCTP_MIB_CURRESTAB
);
791 SCTP_INC_STATS(SCTP_MIB_PASSIVEESTABS
);
792 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_START
, SCTP_NULL());
794 if (new_asoc
->autoclose
)
795 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
796 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
798 /* This will send the COOKIE ACK */
799 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
801 /* Queue the ASSOC_CHANGE event */
802 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
804 /* Send up the Adaptation Layer Indication event */
806 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
807 SCTP_ULPEVENT(ai_ev
));
809 return SCTP_DISPOSITION_CONSUME
;
812 sctp_ulpevent_free(ev
);
814 sctp_chunk_free(repl
);
816 sctp_association_free(new_asoc
);
818 return SCTP_DISPOSITION_NOMEM
;
822 * Respond to a normal COOKIE ACK chunk.
823 * We are the side that is being asked for an association.
825 * RFC 2960 5.1 Normal Establishment of an Association
827 * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the
828 * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie
829 * timer. It may also notify its ULP about the successful
830 * establishment of the association with a Communication Up
831 * notification (see Section 10).
835 * (endpoint, asoc, chunk)
838 * (asoc, reply_msg, msg_up, timers, counters)
840 * The return value is the disposition of the chunk.
842 sctp_disposition_t
sctp_sf_do_5_1E_ca(const struct sctp_endpoint
*ep
,
843 const struct sctp_association
*asoc
,
844 const sctp_subtype_t type
, void *arg
,
845 sctp_cmd_seq_t
*commands
)
847 struct sctp_chunk
*chunk
= arg
;
848 struct sctp_ulpevent
*ev
;
850 if (!sctp_vtag_verify(chunk
, asoc
))
851 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
853 /* Verify that the chunk length for the COOKIE-ACK is OK.
854 * If we don't do this, any bundled chunks may be junked.
856 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
857 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
860 /* Reset init error count upon receipt of COOKIE-ACK,
861 * to avoid problems with the managemement of this
862 * counter in stale cookie situations when a transition back
863 * from the COOKIE-ECHOED state to the COOKIE-WAIT
864 * state is performed.
866 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_COUNTER_RESET
, SCTP_NULL());
868 /* RFC 2960 5.1 Normal Establishment of an Association
870 * E) Upon reception of the COOKIE ACK, endpoint "A" will move
871 * from the COOKIE-ECHOED state to the ESTABLISHED state,
872 * stopping the T1-cookie timer.
874 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
875 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
876 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
877 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
878 SCTP_INC_STATS(SCTP_MIB_CURRESTAB
);
879 SCTP_INC_STATS(SCTP_MIB_ACTIVEESTABS
);
880 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_START
, SCTP_NULL());
882 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
883 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
885 /* It may also notify its ULP about the successful
886 * establishment of the association with a Communication Up
887 * notification (see Section 10).
889 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_COMM_UP
,
890 0, asoc
->c
.sinit_num_ostreams
,
891 asoc
->c
.sinit_max_instreams
,
897 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
899 /* Sockets API Draft Section 5.3.1.6
900 * When a peer sends a Adaptation Layer Indication parameter , SCTP
901 * delivers this notification to inform the application that of the
902 * peers requested adaptation layer.
904 if (asoc
->peer
.adaptation_ind
) {
905 ev
= sctp_ulpevent_make_adaptation_indication(asoc
, GFP_ATOMIC
);
909 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
913 return SCTP_DISPOSITION_CONSUME
;
915 return SCTP_DISPOSITION_NOMEM
;
918 /* Generate and sendout a heartbeat packet. */
919 static sctp_disposition_t
sctp_sf_heartbeat(const struct sctp_endpoint
*ep
,
920 const struct sctp_association
*asoc
,
921 const sctp_subtype_t type
,
923 sctp_cmd_seq_t
*commands
)
925 struct sctp_transport
*transport
= (struct sctp_transport
*) arg
;
926 struct sctp_chunk
*reply
;
927 sctp_sender_hb_info_t hbinfo
;
930 hbinfo
.param_hdr
.type
= SCTP_PARAM_HEARTBEAT_INFO
;
931 hbinfo
.param_hdr
.length
= htons(sizeof(sctp_sender_hb_info_t
));
932 hbinfo
.daddr
= transport
->ipaddr
;
933 hbinfo
.sent_at
= jiffies
;
934 hbinfo
.hb_nonce
= transport
->hb_nonce
;
936 /* Send a heartbeat to our peer. */
937 paylen
= sizeof(sctp_sender_hb_info_t
);
938 reply
= sctp_make_heartbeat(asoc
, transport
, &hbinfo
, paylen
);
940 return SCTP_DISPOSITION_NOMEM
;
942 /* Set rto_pending indicating that an RTT measurement
943 * is started with this heartbeat chunk.
945 sctp_add_cmd_sf(commands
, SCTP_CMD_RTO_PENDING
,
946 SCTP_TRANSPORT(transport
));
948 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
949 return SCTP_DISPOSITION_CONSUME
;
952 /* Generate a HEARTBEAT packet on the given transport. */
953 sctp_disposition_t
sctp_sf_sendbeat_8_3(const struct sctp_endpoint
*ep
,
954 const struct sctp_association
*asoc
,
955 const sctp_subtype_t type
,
957 sctp_cmd_seq_t
*commands
)
959 struct sctp_transport
*transport
= (struct sctp_transport
*) arg
;
961 if (asoc
->overall_error_count
> asoc
->max_retrans
) {
962 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
963 SCTP_ERROR(ETIMEDOUT
));
964 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
965 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
966 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
967 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
968 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
969 return SCTP_DISPOSITION_DELETE_TCB
;
973 * The Sender-specific Heartbeat Info field should normally include
974 * information about the sender's current time when this HEARTBEAT
975 * chunk is sent and the destination transport address to which this
976 * HEARTBEAT is sent (see Section 8.3).
979 if (transport
->param_flags
& SPP_HB_ENABLE
) {
980 if (SCTP_DISPOSITION_NOMEM
==
981 sctp_sf_heartbeat(ep
, asoc
, type
, arg
,
983 return SCTP_DISPOSITION_NOMEM
;
984 /* Set transport error counter and association error counter
985 * when sending heartbeat.
987 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSPORT_RESET
,
988 SCTP_TRANSPORT(transport
));
990 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMER_UPDATE
,
991 SCTP_TRANSPORT(transport
));
993 return SCTP_DISPOSITION_CONSUME
;
997 * Process an heartbeat request.
999 * Section: 8.3 Path Heartbeat
1000 * The receiver of the HEARTBEAT should immediately respond with a
1001 * HEARTBEAT ACK that contains the Heartbeat Information field copied
1002 * from the received HEARTBEAT chunk.
1004 * Verification Tag: 8.5 Verification Tag [Normal verification]
1005 * When receiving an SCTP packet, the endpoint MUST ensure that the
1006 * value in the Verification Tag field of the received SCTP packet
1007 * matches its own Tag. If the received Verification Tag value does not
1008 * match the receiver's own tag value, the receiver shall silently
1009 * discard the packet and shall not process it any further except for
1010 * those cases listed in Section 8.5.1 below.
1013 * (endpoint, asoc, chunk)
1016 * (asoc, reply_msg, msg_up, timers, counters)
1018 * The return value is the disposition of the chunk.
1020 sctp_disposition_t
sctp_sf_beat_8_3(const struct sctp_endpoint
*ep
,
1021 const struct sctp_association
*asoc
,
1022 const sctp_subtype_t type
,
1024 sctp_cmd_seq_t
*commands
)
1026 struct sctp_chunk
*chunk
= arg
;
1027 struct sctp_chunk
*reply
;
1030 if (!sctp_vtag_verify(chunk
, asoc
))
1031 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
1033 /* Make sure that the HEARTBEAT chunk has a valid length. */
1034 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_heartbeat_chunk_t
)))
1035 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
1038 /* 8.3 The receiver of the HEARTBEAT should immediately
1039 * respond with a HEARTBEAT ACK that contains the Heartbeat
1040 * Information field copied from the received HEARTBEAT chunk.
1042 chunk
->subh
.hb_hdr
= (sctp_heartbeathdr_t
*) chunk
->skb
->data
;
1043 paylen
= ntohs(chunk
->chunk_hdr
->length
) - sizeof(sctp_chunkhdr_t
);
1044 if (!pskb_pull(chunk
->skb
, paylen
))
1047 reply
= sctp_make_heartbeat_ack(asoc
, chunk
,
1048 chunk
->subh
.hb_hdr
, paylen
);
1052 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
1053 return SCTP_DISPOSITION_CONSUME
;
1056 return SCTP_DISPOSITION_NOMEM
;
1060 * Process the returning HEARTBEAT ACK.
1062 * Section: 8.3 Path Heartbeat
1063 * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT
1064 * should clear the error counter of the destination transport
1065 * address to which the HEARTBEAT was sent, and mark the destination
1066 * transport address as active if it is not so marked. The endpoint may
1067 * optionally report to the upper layer when an inactive destination
1068 * address is marked as active due to the reception of the latest
1069 * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also
1070 * clear the association overall error count as well (as defined
1073 * The receiver of the HEARTBEAT ACK should also perform an RTT
1074 * measurement for that destination transport address using the time
1075 * value carried in the HEARTBEAT ACK chunk.
1077 * Verification Tag: 8.5 Verification Tag [Normal verification]
1080 * (endpoint, asoc, chunk)
1083 * (asoc, reply_msg, msg_up, timers, counters)
1085 * The return value is the disposition of the chunk.
1087 sctp_disposition_t
sctp_sf_backbeat_8_3(const struct sctp_endpoint
*ep
,
1088 const struct sctp_association
*asoc
,
1089 const sctp_subtype_t type
,
1091 sctp_cmd_seq_t
*commands
)
1093 struct sctp_chunk
*chunk
= arg
;
1094 union sctp_addr from_addr
;
1095 struct sctp_transport
*link
;
1096 sctp_sender_hb_info_t
*hbinfo
;
1097 unsigned long max_interval
;
1099 if (!sctp_vtag_verify(chunk
, asoc
))
1100 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
1102 /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */
1103 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_heartbeat_chunk_t
)))
1104 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
1107 hbinfo
= (sctp_sender_hb_info_t
*) chunk
->skb
->data
;
1108 /* Make sure that the length of the parameter is what we expect */
1109 if (ntohs(hbinfo
->param_hdr
.length
) !=
1110 sizeof(sctp_sender_hb_info_t
)) {
1111 return SCTP_DISPOSITION_DISCARD
;
1114 from_addr
= hbinfo
->daddr
;
1115 link
= sctp_assoc_lookup_paddr(asoc
, &from_addr
);
1117 /* This should never happen, but lets log it if so. */
1118 if (unlikely(!link
)) {
1119 if (from_addr
.sa
.sa_family
== AF_INET6
) {
1120 if (net_ratelimit())
1122 "%s association %p could not find address "
1126 NIP6(from_addr
.v6
.sin6_addr
));
1128 if (net_ratelimit())
1130 "%s association %p could not find address "
1134 NIPQUAD(from_addr
.v4
.sin_addr
.s_addr
));
1136 return SCTP_DISPOSITION_DISCARD
;
1139 /* Validate the 64-bit random nonce. */
1140 if (hbinfo
->hb_nonce
!= link
->hb_nonce
)
1141 return SCTP_DISPOSITION_DISCARD
;
1143 max_interval
= link
->hbinterval
+ link
->rto
;
1145 /* Check if the timestamp looks valid. */
1146 if (time_after(hbinfo
->sent_at
, jiffies
) ||
1147 time_after(jiffies
, hbinfo
->sent_at
+ max_interval
)) {
1148 SCTP_DEBUG_PRINTK("%s: HEARTBEAT ACK with invalid timestamp "
1149 "received for transport: %p\n",
1151 return SCTP_DISPOSITION_DISCARD
;
1154 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of
1155 * the HEARTBEAT should clear the error counter of the
1156 * destination transport address to which the HEARTBEAT was
1157 * sent and mark the destination transport address as active if
1158 * it is not so marked.
1160 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSPORT_ON
, SCTP_TRANSPORT(link
));
1162 return SCTP_DISPOSITION_CONSUME
;
1165 /* Helper function to send out an abort for the restart
1168 static int sctp_sf_send_restart_abort(union sctp_addr
*ssa
,
1169 struct sctp_chunk
*init
,
1170 sctp_cmd_seq_t
*commands
)
1173 struct sctp_packet
*pkt
;
1174 union sctp_addr_param
*addrparm
;
1175 struct sctp_errhdr
*errhdr
;
1176 struct sctp_endpoint
*ep
;
1177 char buffer
[sizeof(struct sctp_errhdr
)+sizeof(union sctp_addr_param
)];
1178 struct sctp_af
*af
= sctp_get_af_specific(ssa
->v4
.sin_family
);
1180 /* Build the error on the stack. We are way to malloc crazy
1181 * throughout the code today.
1183 errhdr
= (struct sctp_errhdr
*)buffer
;
1184 addrparm
= (union sctp_addr_param
*)errhdr
->variable
;
1186 /* Copy into a parm format. */
1187 len
= af
->to_addr_param(ssa
, addrparm
);
1188 len
+= sizeof(sctp_errhdr_t
);
1190 errhdr
->cause
= SCTP_ERROR_RESTART
;
1191 errhdr
->length
= htons(len
);
1193 /* Assign to the control socket. */
1194 ep
= sctp_sk((sctp_get_ctl_sock()))->ep
;
1196 /* Association is NULL since this may be a restart attack and we
1197 * want to send back the attacker's vtag.
1199 pkt
= sctp_abort_pkt_new(ep
, NULL
, init
, errhdr
, len
);
1203 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
, SCTP_PACKET(pkt
));
1205 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
1207 /* Discard the rest of the inbound packet. */
1208 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
, SCTP_NULL());
1211 /* Even if there is no memory, treat as a failure so
1212 * the packet will get dropped.
1217 /* A restart is occurring, check to make sure no new addresses
1218 * are being added as we may be under a takeover attack.
1220 static int sctp_sf_check_restart_addrs(const struct sctp_association
*new_asoc
,
1221 const struct sctp_association
*asoc
,
1222 struct sctp_chunk
*init
,
1223 sctp_cmd_seq_t
*commands
)
1225 struct sctp_transport
*new_addr
, *addr
;
1228 /* Implementor's Guide - Sectin 5.2.2
1230 * Before responding the endpoint MUST check to see if the
1231 * unexpected INIT adds new addresses to the association. If new
1232 * addresses are added to the association, the endpoint MUST respond
1236 /* Search through all current addresses and make sure
1237 * we aren't adding any new ones.
1242 list_for_each_entry(new_addr
, &new_asoc
->peer
.transport_addr_list
,
1245 list_for_each_entry(addr
, &asoc
->peer
.transport_addr_list
,
1247 if (sctp_cmp_addr_exact(&new_addr
->ipaddr
,
1257 /* If a new address was added, ABORT the sender. */
1258 if (!found
&& new_addr
) {
1259 sctp_sf_send_restart_abort(&new_addr
->ipaddr
, init
, commands
);
1262 /* Return success if all addresses were found. */
1266 /* Populate the verification/tie tags based on overlapping INIT
1269 * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state.
1271 static void sctp_tietags_populate(struct sctp_association
*new_asoc
,
1272 const struct sctp_association
*asoc
)
1274 switch (asoc
->state
) {
1276 /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */
1278 case SCTP_STATE_COOKIE_WAIT
:
1279 new_asoc
->c
.my_vtag
= asoc
->c
.my_vtag
;
1280 new_asoc
->c
.my_ttag
= asoc
->c
.my_vtag
;
1281 new_asoc
->c
.peer_ttag
= 0;
1284 case SCTP_STATE_COOKIE_ECHOED
:
1285 new_asoc
->c
.my_vtag
= asoc
->c
.my_vtag
;
1286 new_asoc
->c
.my_ttag
= asoc
->c
.my_vtag
;
1287 new_asoc
->c
.peer_ttag
= asoc
->c
.peer_vtag
;
1290 /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED,
1291 * COOKIE-WAIT and SHUTDOWN-ACK-SENT
1294 new_asoc
->c
.my_ttag
= asoc
->c
.my_vtag
;
1295 new_asoc
->c
.peer_ttag
= asoc
->c
.peer_vtag
;
1299 /* Other parameters for the endpoint SHOULD be copied from the
1300 * existing parameters of the association (e.g. number of
1301 * outbound streams) into the INIT ACK and cookie.
1303 new_asoc
->rwnd
= asoc
->rwnd
;
1304 new_asoc
->c
.sinit_num_ostreams
= asoc
->c
.sinit_num_ostreams
;
1305 new_asoc
->c
.sinit_max_instreams
= asoc
->c
.sinit_max_instreams
;
1306 new_asoc
->c
.initial_tsn
= asoc
->c
.initial_tsn
;
1310 * Compare vtag/tietag values to determine unexpected COOKIE-ECHO
1313 * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists.
1315 * Returns value representing action to be taken. These action values
1316 * correspond to Action/Description values in RFC 2960, Table 2.
1318 static char sctp_tietags_compare(struct sctp_association
*new_asoc
,
1319 const struct sctp_association
*asoc
)
1321 /* In this case, the peer may have restarted. */
1322 if ((asoc
->c
.my_vtag
!= new_asoc
->c
.my_vtag
) &&
1323 (asoc
->c
.peer_vtag
!= new_asoc
->c
.peer_vtag
) &&
1324 (asoc
->c
.my_vtag
== new_asoc
->c
.my_ttag
) &&
1325 (asoc
->c
.peer_vtag
== new_asoc
->c
.peer_ttag
))
1328 /* Collision case B. */
1329 if ((asoc
->c
.my_vtag
== new_asoc
->c
.my_vtag
) &&
1330 ((asoc
->c
.peer_vtag
!= new_asoc
->c
.peer_vtag
) ||
1331 (0 == asoc
->c
.peer_vtag
))) {
1335 /* Collision case D. */
1336 if ((asoc
->c
.my_vtag
== new_asoc
->c
.my_vtag
) &&
1337 (asoc
->c
.peer_vtag
== new_asoc
->c
.peer_vtag
))
1340 /* Collision case C. */
1341 if ((asoc
->c
.my_vtag
!= new_asoc
->c
.my_vtag
) &&
1342 (asoc
->c
.peer_vtag
== new_asoc
->c
.peer_vtag
) &&
1343 (0 == new_asoc
->c
.my_ttag
) &&
1344 (0 == new_asoc
->c
.peer_ttag
))
1347 /* No match to any of the special cases; discard this packet. */
1351 /* Common helper routine for both duplicate and simulataneous INIT
1354 static sctp_disposition_t
sctp_sf_do_unexpected_init(
1355 const struct sctp_endpoint
*ep
,
1356 const struct sctp_association
*asoc
,
1357 const sctp_subtype_t type
,
1358 void *arg
, sctp_cmd_seq_t
*commands
)
1360 sctp_disposition_t retval
;
1361 struct sctp_chunk
*chunk
= arg
;
1362 struct sctp_chunk
*repl
;
1363 struct sctp_association
*new_asoc
;
1364 struct sctp_chunk
*err_chunk
;
1365 struct sctp_packet
*packet
;
1366 sctp_unrecognized_param_t
*unk_param
;
1370 * An endpoint MUST NOT bundle INIT, INIT ACK or
1371 * SHUTDOWN COMPLETE with any other chunks.
1374 * Furthermore, we require that the receiver of an INIT chunk MUST
1375 * enforce these rules by silently discarding an arriving packet
1376 * with an INIT chunk that is bundled with other chunks.
1378 if (!chunk
->singleton
)
1379 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
1381 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
1384 if (chunk
->sctp_hdr
->vtag
!= 0)
1385 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
, commands
);
1387 /* Make sure that the INIT chunk has a valid length.
1388 * In this case, we generate a protocol violation since we have
1389 * an association established.
1391 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_init_chunk_t
)))
1392 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
1394 /* Grab the INIT header. */
1395 chunk
->subh
.init_hdr
= (sctp_inithdr_t
*) chunk
->skb
->data
;
1397 /* Tag the variable length parameters. */
1398 chunk
->param_hdr
.v
= skb_pull(chunk
->skb
, sizeof(sctp_inithdr_t
));
1400 /* Verify the INIT chunk before processing it. */
1402 if (!sctp_verify_init(asoc
, chunk
->chunk_hdr
->type
,
1403 (sctp_init_chunk_t
*)chunk
->chunk_hdr
, chunk
,
1405 /* This chunk contains fatal error. It is to be discarded.
1406 * Send an ABORT, with causes if there is any.
1409 packet
= sctp_abort_pkt_new(ep
, asoc
, arg
,
1410 (__u8
*)(err_chunk
->chunk_hdr
) +
1411 sizeof(sctp_chunkhdr_t
),
1412 ntohs(err_chunk
->chunk_hdr
->length
) -
1413 sizeof(sctp_chunkhdr_t
));
1416 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
1417 SCTP_PACKET(packet
));
1418 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
1419 retval
= SCTP_DISPOSITION_CONSUME
;
1421 retval
= SCTP_DISPOSITION_NOMEM
;
1425 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
,
1431 * Other parameters for the endpoint SHOULD be copied from the
1432 * existing parameters of the association (e.g. number of
1433 * outbound streams) into the INIT ACK and cookie.
1434 * FIXME: We are copying parameters from the endpoint not the
1437 new_asoc
= sctp_make_temp_asoc(ep
, chunk
, GFP_ATOMIC
);
1441 /* In the outbound INIT ACK the endpoint MUST copy its current
1442 * Verification Tag and Peers Verification tag into a reserved
1443 * place (local tie-tag and per tie-tag) within the state cookie.
1445 if (!sctp_process_init(new_asoc
, chunk
->chunk_hdr
->type
,
1447 (sctp_init_chunk_t
*)chunk
->chunk_hdr
,
1451 /* Make sure no new addresses are being added during the
1452 * restart. Do not do this check for COOKIE-WAIT state,
1453 * since there are no peer addresses to check against.
1454 * Upon return an ABORT will have been sent if needed.
1456 if (!sctp_state(asoc
, COOKIE_WAIT
)) {
1457 if (!sctp_sf_check_restart_addrs(new_asoc
, asoc
, chunk
,
1459 retval
= SCTP_DISPOSITION_CONSUME
;
1464 sctp_tietags_populate(new_asoc
, asoc
);
1466 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
1468 /* If there are errors need to be reported for unknown parameters,
1469 * make sure to reserve enough room in the INIT ACK for them.
1473 len
= ntohs(err_chunk
->chunk_hdr
->length
) -
1474 sizeof(sctp_chunkhdr_t
);
1477 if (sctp_assoc_set_bind_addr_from_ep(new_asoc
, GFP_ATOMIC
) < 0)
1480 repl
= sctp_make_init_ack(new_asoc
, chunk
, GFP_ATOMIC
, len
);
1484 /* If there are errors need to be reported for unknown parameters,
1485 * include them in the outgoing INIT ACK as "Unrecognized parameter"
1489 /* Get the "Unrecognized parameter" parameter(s) out of the
1490 * ERROR chunk generated by sctp_verify_init(). Since the
1491 * error cause code for "unknown parameter" and the
1492 * "Unrecognized parameter" type is the same, we can
1493 * construct the parameters in INIT ACK by copying the
1494 * ERROR causes over.
1496 unk_param
= (sctp_unrecognized_param_t
*)
1497 ((__u8
*)(err_chunk
->chunk_hdr
) +
1498 sizeof(sctp_chunkhdr_t
));
1499 /* Replace the cause code with the "Unrecognized parameter"
1502 sctp_addto_chunk(repl
, len
, unk_param
);
1505 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(new_asoc
));
1506 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1509 * Note: After sending out INIT ACK with the State Cookie parameter,
1510 * "Z" MUST NOT allocate any resources for this new association.
1511 * Otherwise, "Z" will be vulnerable to resource attacks.
1513 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
1514 retval
= SCTP_DISPOSITION_CONSUME
;
1519 retval
= SCTP_DISPOSITION_NOMEM
;
1522 sctp_association_free(new_asoc
);
1525 sctp_chunk_free(err_chunk
);
1530 * Handle simultanous INIT.
1531 * This means we started an INIT and then we got an INIT request from
1534 * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B)
1535 * This usually indicates an initialization collision, i.e., each
1536 * endpoint is attempting, at about the same time, to establish an
1537 * association with the other endpoint.
1539 * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an
1540 * endpoint MUST respond with an INIT ACK using the same parameters it
1541 * sent in its original INIT chunk (including its Verification Tag,
1542 * unchanged). These original parameters are combined with those from the
1543 * newly received INIT chunk. The endpoint shall also generate a State
1544 * Cookie with the INIT ACK. The endpoint uses the parameters sent in its
1545 * INIT to calculate the State Cookie.
1547 * After that, the endpoint MUST NOT change its state, the T1-init
1548 * timer shall be left running and the corresponding TCB MUST NOT be
1549 * destroyed. The normal procedures for handling State Cookies when
1550 * a TCB exists will resolve the duplicate INITs to a single association.
1552 * For an endpoint that is in the COOKIE-ECHOED state it MUST populate
1553 * its Tie-Tags with the Tag information of itself and its peer (see
1554 * section 5.2.2 for a description of the Tie-Tags).
1556 * Verification Tag: Not explicit, but an INIT can not have a valid
1557 * verification tag, so we skip the check.
1560 * (endpoint, asoc, chunk)
1563 * (asoc, reply_msg, msg_up, timers, counters)
1565 * The return value is the disposition of the chunk.
1567 sctp_disposition_t
sctp_sf_do_5_2_1_siminit(const struct sctp_endpoint
*ep
,
1568 const struct sctp_association
*asoc
,
1569 const sctp_subtype_t type
,
1571 sctp_cmd_seq_t
*commands
)
1573 /* Call helper to do the real work for both simulataneous and
1574 * duplicate INIT chunk handling.
1576 return sctp_sf_do_unexpected_init(ep
, asoc
, type
, arg
, commands
);
1580 * Handle duplicated INIT messages. These are usually delayed
1583 * Section: 5.2.2 Unexpected INIT in States Other than CLOSED,
1584 * COOKIE-ECHOED and COOKIE-WAIT
1586 * Unless otherwise stated, upon reception of an unexpected INIT for
1587 * this association, the endpoint shall generate an INIT ACK with a
1588 * State Cookie. In the outbound INIT ACK the endpoint MUST copy its
1589 * current Verification Tag and peer's Verification Tag into a reserved
1590 * place within the state cookie. We shall refer to these locations as
1591 * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet
1592 * containing this INIT ACK MUST carry a Verification Tag value equal to
1593 * the Initiation Tag found in the unexpected INIT. And the INIT ACK
1594 * MUST contain a new Initiation Tag (randomly generated see Section
1595 * 5.3.1). Other parameters for the endpoint SHOULD be copied from the
1596 * existing parameters of the association (e.g. number of outbound
1597 * streams) into the INIT ACK and cookie.
1599 * After sending out the INIT ACK, the endpoint shall take no further
1600 * actions, i.e., the existing association, including its current state,
1601 * and the corresponding TCB MUST NOT be changed.
1603 * Note: Only when a TCB exists and the association is not in a COOKIE-
1604 * WAIT state are the Tie-Tags populated. For a normal association INIT
1605 * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be
1606 * set to 0 (indicating that no previous TCB existed). The INIT ACK and
1607 * State Cookie are populated as specified in section 5.2.1.
1609 * Verification Tag: Not specified, but an INIT has no way of knowing
1610 * what the verification tag could be, so we ignore it.
1613 * (endpoint, asoc, chunk)
1616 * (asoc, reply_msg, msg_up, timers, counters)
1618 * The return value is the disposition of the chunk.
1620 sctp_disposition_t
sctp_sf_do_5_2_2_dupinit(const struct sctp_endpoint
*ep
,
1621 const struct sctp_association
*asoc
,
1622 const sctp_subtype_t type
,
1624 sctp_cmd_seq_t
*commands
)
1626 /* Call helper to do the real work for both simulataneous and
1627 * duplicate INIT chunk handling.
1629 return sctp_sf_do_unexpected_init(ep
, asoc
, type
, arg
, commands
);
1634 * Unexpected INIT-ACK handler.
1637 * If an INIT ACK received by an endpoint in any state other than the
1638 * COOKIE-WAIT state, the endpoint should discard the INIT ACK chunk.
1639 * An unexpected INIT ACK usually indicates the processing of an old or
1640 * duplicated INIT chunk.
1642 sctp_disposition_t
sctp_sf_do_5_2_3_initack(const struct sctp_endpoint
*ep
,
1643 const struct sctp_association
*asoc
,
1644 const sctp_subtype_t type
,
1645 void *arg
, sctp_cmd_seq_t
*commands
)
1647 /* Per the above section, we'll discard the chunk if we have an
1648 * endpoint. If this is an OOTB INIT-ACK, treat it as such.
1650 if (ep
== sctp_sk((sctp_get_ctl_sock()))->ep
)
1651 return sctp_sf_ootb(ep
, asoc
, type
, arg
, commands
);
1653 return sctp_sf_discard_chunk(ep
, asoc
, type
, arg
, commands
);
1656 /* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A')
1659 * A) In this case, the peer may have restarted.
1661 static sctp_disposition_t
sctp_sf_do_dupcook_a(const struct sctp_endpoint
*ep
,
1662 const struct sctp_association
*asoc
,
1663 struct sctp_chunk
*chunk
,
1664 sctp_cmd_seq_t
*commands
,
1665 struct sctp_association
*new_asoc
)
1667 sctp_init_chunk_t
*peer_init
;
1668 struct sctp_ulpevent
*ev
;
1669 struct sctp_chunk
*repl
;
1670 struct sctp_chunk
*err
;
1671 sctp_disposition_t disposition
;
1673 /* new_asoc is a brand-new association, so these are not yet
1674 * side effects--it is safe to run them here.
1676 peer_init
= &chunk
->subh
.cookie_hdr
->c
.peer_init
[0];
1678 if (!sctp_process_init(new_asoc
, chunk
->chunk_hdr
->type
,
1679 sctp_source(chunk
), peer_init
,
1683 /* Make sure no new addresses are being added during the
1684 * restart. Though this is a pretty complicated attack
1685 * since you'd have to get inside the cookie.
1687 if (!sctp_sf_check_restart_addrs(new_asoc
, asoc
, chunk
, commands
)) {
1688 return SCTP_DISPOSITION_CONSUME
;
1691 /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes
1692 * the peer has restarted (Action A), it MUST NOT setup a new
1693 * association but instead resend the SHUTDOWN ACK and send an ERROR
1694 * chunk with a "Cookie Received while Shutting Down" error cause to
1697 if (sctp_state(asoc
, SHUTDOWN_ACK_SENT
)) {
1698 disposition
= sctp_sf_do_9_2_reshutack(ep
, asoc
,
1699 SCTP_ST_CHUNK(chunk
->chunk_hdr
->type
),
1701 if (SCTP_DISPOSITION_NOMEM
== disposition
)
1704 err
= sctp_make_op_error(asoc
, chunk
,
1705 SCTP_ERROR_COOKIE_IN_SHUTDOWN
,
1708 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
1711 return SCTP_DISPOSITION_CONSUME
;
1714 /* For now, fail any unsent/unacked data. Consider the optional
1715 * choice of resending of this data.
1717 sctp_add_cmd_sf(commands
, SCTP_CMD_PURGE_OUTQUEUE
, SCTP_NULL());
1719 repl
= sctp_make_cookie_ack(new_asoc
, chunk
);
1723 /* Report association restart to upper layer. */
1724 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_RESTART
, 0,
1725 new_asoc
->c
.sinit_num_ostreams
,
1726 new_asoc
->c
.sinit_max_instreams
,
1731 /* Update the content of current association. */
1732 sctp_add_cmd_sf(commands
, SCTP_CMD_UPDATE_ASSOC
, SCTP_ASOC(new_asoc
));
1733 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1734 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
1735 return SCTP_DISPOSITION_CONSUME
;
1738 sctp_chunk_free(repl
);
1740 return SCTP_DISPOSITION_NOMEM
;
1743 /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B')
1746 * B) In this case, both sides may be attempting to start an association
1747 * at about the same time but the peer endpoint started its INIT
1748 * after responding to the local endpoint's INIT
1750 /* This case represents an initialization collision. */
1751 static sctp_disposition_t
sctp_sf_do_dupcook_b(const struct sctp_endpoint
*ep
,
1752 const struct sctp_association
*asoc
,
1753 struct sctp_chunk
*chunk
,
1754 sctp_cmd_seq_t
*commands
,
1755 struct sctp_association
*new_asoc
)
1757 sctp_init_chunk_t
*peer_init
;
1758 struct sctp_chunk
*repl
;
1760 /* new_asoc is a brand-new association, so these are not yet
1761 * side effects--it is safe to run them here.
1763 peer_init
= &chunk
->subh
.cookie_hdr
->c
.peer_init
[0];
1764 if (!sctp_process_init(new_asoc
, chunk
->chunk_hdr
->type
,
1765 sctp_source(chunk
), peer_init
,
1769 /* Update the content of current association. */
1770 sctp_add_cmd_sf(commands
, SCTP_CMD_UPDATE_ASSOC
, SCTP_ASOC(new_asoc
));
1771 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
1772 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
1773 SCTP_INC_STATS(SCTP_MIB_CURRESTAB
);
1774 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_START
, SCTP_NULL());
1776 repl
= sctp_make_cookie_ack(new_asoc
, chunk
);
1780 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1782 /* RFC 2960 5.1 Normal Establishment of an Association
1784 * D) IMPLEMENTATION NOTE: An implementation may choose to
1785 * send the Communication Up notification to the SCTP user
1786 * upon reception of a valid COOKIE ECHO chunk.
1788 * Sadly, this needs to be implemented as a side-effect, because
1789 * we are not guaranteed to have set the association id of the real
1790 * association and so these notifications need to be delayed until
1791 * the association id is allocated.
1794 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_CHANGE
, SCTP_U8(SCTP_COMM_UP
));
1796 /* Sockets API Draft Section 5.3.1.6
1797 * When a peer sends a Adaptation Layer Indication parameter , SCTP
1798 * delivers this notification to inform the application that of the
1799 * peers requested adaptation layer.
1801 * This also needs to be done as a side effect for the same reason as
1804 if (asoc
->peer
.adaptation_ind
)
1805 sctp_add_cmd_sf(commands
, SCTP_CMD_ADAPTATION_IND
, SCTP_NULL());
1807 return SCTP_DISPOSITION_CONSUME
;
1810 return SCTP_DISPOSITION_NOMEM
;
1813 /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C')
1816 * C) In this case, the local endpoint's cookie has arrived late.
1817 * Before it arrived, the local endpoint sent an INIT and received an
1818 * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag
1819 * but a new tag of its own.
1821 /* This case represents an initialization collision. */
1822 static sctp_disposition_t
sctp_sf_do_dupcook_c(const struct sctp_endpoint
*ep
,
1823 const struct sctp_association
*asoc
,
1824 struct sctp_chunk
*chunk
,
1825 sctp_cmd_seq_t
*commands
,
1826 struct sctp_association
*new_asoc
)
1828 /* The cookie should be silently discarded.
1829 * The endpoint SHOULD NOT change states and should leave
1830 * any timers running.
1832 return SCTP_DISPOSITION_DISCARD
;
1835 /* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D')
1839 * D) When both local and remote tags match the endpoint should always
1840 * enter the ESTABLISHED state, if it has not already done so.
1842 /* This case represents an initialization collision. */
1843 static sctp_disposition_t
sctp_sf_do_dupcook_d(const struct sctp_endpoint
*ep
,
1844 const struct sctp_association
*asoc
,
1845 struct sctp_chunk
*chunk
,
1846 sctp_cmd_seq_t
*commands
,
1847 struct sctp_association
*new_asoc
)
1849 struct sctp_ulpevent
*ev
= NULL
, *ai_ev
= NULL
;
1850 struct sctp_chunk
*repl
;
1852 /* Clarification from Implementor's Guide:
1853 * D) When both local and remote tags match the endpoint should
1854 * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state.
1855 * It should stop any cookie timer that may be running and send
1859 /* Don't accidentally move back into established state. */
1860 if (asoc
->state
< SCTP_STATE_ESTABLISHED
) {
1861 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
1862 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
1863 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
1864 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
1865 SCTP_INC_STATS(SCTP_MIB_CURRESTAB
);
1866 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_START
,
1869 /* RFC 2960 5.1 Normal Establishment of an Association
1871 * D) IMPLEMENTATION NOTE: An implementation may choose
1872 * to send the Communication Up notification to the
1873 * SCTP user upon reception of a valid COOKIE
1876 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0,
1878 asoc
->c
.sinit_num_ostreams
,
1879 asoc
->c
.sinit_max_instreams
,
1884 /* Sockets API Draft Section 5.3.1.6
1885 * When a peer sends a Adaptation Layer Indication parameter,
1886 * SCTP delivers this notification to inform the application
1887 * that of the peers requested adaptation layer.
1889 if (asoc
->peer
.adaptation_ind
) {
1890 ai_ev
= sctp_ulpevent_make_adaptation_indication(asoc
,
1898 repl
= sctp_make_cookie_ack(new_asoc
, chunk
);
1902 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1905 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
1908 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
1909 SCTP_ULPEVENT(ai_ev
));
1911 return SCTP_DISPOSITION_CONSUME
;
1915 sctp_ulpevent_free(ai_ev
);
1917 sctp_ulpevent_free(ev
);
1918 return SCTP_DISPOSITION_NOMEM
;
1922 * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying
1923 * chunk was retransmitted and then delayed in the network.
1925 * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists
1927 * Verification Tag: None. Do cookie validation.
1930 * (endpoint, asoc, chunk)
1933 * (asoc, reply_msg, msg_up, timers, counters)
1935 * The return value is the disposition of the chunk.
1937 sctp_disposition_t
sctp_sf_do_5_2_4_dupcook(const struct sctp_endpoint
*ep
,
1938 const struct sctp_association
*asoc
,
1939 const sctp_subtype_t type
,
1941 sctp_cmd_seq_t
*commands
)
1943 sctp_disposition_t retval
;
1944 struct sctp_chunk
*chunk
= arg
;
1945 struct sctp_association
*new_asoc
;
1948 struct sctp_chunk
*err_chk_p
;
1950 /* Make sure that the chunk has a valid length from the protocol
1951 * perspective. In this case check to make sure we have at least
1952 * enough for the chunk header. Cookie length verification is
1955 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
1956 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
1959 /* "Decode" the chunk. We have no optional parameters so we
1960 * are in good shape.
1962 chunk
->subh
.cookie_hdr
= (struct sctp_signed_cookie
*)chunk
->skb
->data
;
1963 if (!pskb_pull(chunk
->skb
, ntohs(chunk
->chunk_hdr
->length
) -
1964 sizeof(sctp_chunkhdr_t
)))
1967 /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
1968 * of a duplicate COOKIE ECHO match the Verification Tags of the
1969 * current association, consider the State Cookie valid even if
1970 * the lifespan is exceeded.
1972 new_asoc
= sctp_unpack_cookie(ep
, asoc
, chunk
, GFP_ATOMIC
, &error
,
1976 * If the re-build failed, what is the proper error path
1979 * [We should abort the association. --piggy]
1982 /* FIXME: Several errors are possible. A bad cookie should
1983 * be silently discarded, but think about logging it too.
1986 case -SCTP_IERROR_NOMEM
:
1989 case -SCTP_IERROR_STALE_COOKIE
:
1990 sctp_send_stale_cookie_err(ep
, asoc
, chunk
, commands
,
1992 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
1993 case -SCTP_IERROR_BAD_SIG
:
1995 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
1999 /* Compare the tie_tag in cookie with the verification tag of
2000 * current association.
2002 action
= sctp_tietags_compare(new_asoc
, asoc
);
2005 case 'A': /* Association restart. */
2006 retval
= sctp_sf_do_dupcook_a(ep
, asoc
, chunk
, commands
,
2010 case 'B': /* Collision case B. */
2011 retval
= sctp_sf_do_dupcook_b(ep
, asoc
, chunk
, commands
,
2015 case 'C': /* Collision case C. */
2016 retval
= sctp_sf_do_dupcook_c(ep
, asoc
, chunk
, commands
,
2020 case 'D': /* Collision case D. */
2021 retval
= sctp_sf_do_dupcook_d(ep
, asoc
, chunk
, commands
,
2025 default: /* Discard packet for all others. */
2026 retval
= sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2030 /* Delete the tempory new association. */
2031 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(new_asoc
));
2032 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
2037 return SCTP_DISPOSITION_NOMEM
;
2041 * Process an ABORT. (SHUTDOWN-PENDING state)
2043 * See sctp_sf_do_9_1_abort().
2045 sctp_disposition_t
sctp_sf_shutdown_pending_abort(
2046 const struct sctp_endpoint
*ep
,
2047 const struct sctp_association
*asoc
,
2048 const sctp_subtype_t type
,
2050 sctp_cmd_seq_t
*commands
)
2052 struct sctp_chunk
*chunk
= arg
;
2054 if (!sctp_vtag_verify_either(chunk
, asoc
))
2055 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2057 /* Make sure that the ABORT chunk has a valid length.
2058 * Since this is an ABORT chunk, we have to discard it
2059 * because of the following text:
2060 * RFC 2960, Section 3.3.7
2061 * If an endpoint receives an ABORT with a format error or for an
2062 * association that doesn't exist, it MUST silently discard it.
2063 * Becasue the length is "invalid", we can't really discard just
2064 * as we do not know its true length. So, to be safe, discard the
2067 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_abort_chunk_t
)))
2068 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2070 /* ADD-IP: Special case for ABORT chunks
2071 * F4) One special consideration is that ABORT Chunks arriving
2072 * destined to the IP address being deleted MUST be
2073 * ignored (see Section 5.3.1 for further details).
2075 if (SCTP_ADDR_DEL
==
2076 sctp_bind_addr_state(&asoc
->base
.bind_addr
, &chunk
->dest
))
2077 return sctp_sf_discard_chunk(ep
, asoc
, type
, arg
, commands
);
2079 /* Stop the T5-shutdown guard timer. */
2080 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
2081 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
2083 return __sctp_sf_do_9_1_abort(ep
, asoc
, type
, arg
, commands
);
2087 * Process an ABORT. (SHUTDOWN-SENT state)
2089 * See sctp_sf_do_9_1_abort().
2091 sctp_disposition_t
sctp_sf_shutdown_sent_abort(const struct sctp_endpoint
*ep
,
2092 const struct sctp_association
*asoc
,
2093 const sctp_subtype_t type
,
2095 sctp_cmd_seq_t
*commands
)
2097 struct sctp_chunk
*chunk
= arg
;
2099 if (!sctp_vtag_verify_either(chunk
, asoc
))
2100 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2102 /* Make sure that the ABORT chunk has a valid length.
2103 * Since this is an ABORT chunk, we have to discard it
2104 * because of the following text:
2105 * RFC 2960, Section 3.3.7
2106 * If an endpoint receives an ABORT with a format error or for an
2107 * association that doesn't exist, it MUST silently discard it.
2108 * Becasue the length is "invalid", we can't really discard just
2109 * as we do not know its true length. So, to be safe, discard the
2112 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_abort_chunk_t
)))
2113 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2115 /* ADD-IP: Special case for ABORT chunks
2116 * F4) One special consideration is that ABORT Chunks arriving
2117 * destined to the IP address being deleted MUST be
2118 * ignored (see Section 5.3.1 for further details).
2120 if (SCTP_ADDR_DEL
==
2121 sctp_bind_addr_state(&asoc
->base
.bind_addr
, &chunk
->dest
))
2122 return sctp_sf_discard_chunk(ep
, asoc
, type
, arg
, commands
);
2124 /* Stop the T2-shutdown timer. */
2125 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
2126 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
2128 /* Stop the T5-shutdown guard timer. */
2129 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
2130 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
2132 return __sctp_sf_do_9_1_abort(ep
, asoc
, type
, arg
, commands
);
2136 * Process an ABORT. (SHUTDOWN-ACK-SENT state)
2138 * See sctp_sf_do_9_1_abort().
2140 sctp_disposition_t
sctp_sf_shutdown_ack_sent_abort(
2141 const struct sctp_endpoint
*ep
,
2142 const struct sctp_association
*asoc
,
2143 const sctp_subtype_t type
,
2145 sctp_cmd_seq_t
*commands
)
2147 /* The same T2 timer, so we should be able to use
2148 * common function with the SHUTDOWN-SENT state.
2150 return sctp_sf_shutdown_sent_abort(ep
, asoc
, type
, arg
, commands
);
2154 * Handle an Error received in COOKIE_ECHOED state.
2156 * Only handle the error type of stale COOKIE Error, the other errors will
2160 * (endpoint, asoc, chunk)
2163 * (asoc, reply_msg, msg_up, timers, counters)
2165 * The return value is the disposition of the chunk.
2167 sctp_disposition_t
sctp_sf_cookie_echoed_err(const struct sctp_endpoint
*ep
,
2168 const struct sctp_association
*asoc
,
2169 const sctp_subtype_t type
,
2171 sctp_cmd_seq_t
*commands
)
2173 struct sctp_chunk
*chunk
= arg
;
2176 if (!sctp_vtag_verify(chunk
, asoc
))
2177 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2179 /* Make sure that the ERROR chunk has a valid length.
2180 * The parameter walking depends on this as well.
2182 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_operr_chunk_t
)))
2183 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2186 /* Process the error here */
2187 /* FUTURE FIXME: When PR-SCTP related and other optional
2188 * parms are emitted, this will have to change to handle multiple
2191 sctp_walk_errors(err
, chunk
->chunk_hdr
) {
2192 if (SCTP_ERROR_STALE_COOKIE
== err
->cause
)
2193 return sctp_sf_do_5_2_6_stale(ep
, asoc
, type
,
2197 /* It is possible to have malformed error causes, and that
2198 * will cause us to end the walk early. However, since
2199 * we are discarding the packet, there should be no adverse
2202 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2206 * Handle a Stale COOKIE Error
2208 * Section: 5.2.6 Handle Stale COOKIE Error
2209 * If the association is in the COOKIE-ECHOED state, the endpoint may elect
2210 * one of the following three alternatives.
2212 * 3) Send a new INIT chunk to the endpoint, adding a Cookie
2213 * Preservative parameter requesting an extension to the lifetime of
2214 * the State Cookie. When calculating the time extension, an
2215 * implementation SHOULD use the RTT information measured based on the
2216 * previous COOKIE ECHO / ERROR exchange, and should add no more
2217 * than 1 second beyond the measured RTT, due to long State Cookie
2218 * lifetimes making the endpoint more subject to a replay attack.
2220 * Verification Tag: Not explicit, but safe to ignore.
2223 * (endpoint, asoc, chunk)
2226 * (asoc, reply_msg, msg_up, timers, counters)
2228 * The return value is the disposition of the chunk.
2230 static sctp_disposition_t
sctp_sf_do_5_2_6_stale(const struct sctp_endpoint
*ep
,
2231 const struct sctp_association
*asoc
,
2232 const sctp_subtype_t type
,
2234 sctp_cmd_seq_t
*commands
)
2236 struct sctp_chunk
*chunk
= arg
;
2238 sctp_cookie_preserve_param_t bht
;
2240 struct sctp_chunk
*reply
;
2241 struct sctp_bind_addr
*bp
;
2242 int attempts
= asoc
->init_err_counter
+ 1;
2244 if (attempts
> asoc
->max_init_attempts
) {
2245 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
2246 SCTP_ERROR(ETIMEDOUT
));
2247 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
2248 SCTP_PERR(SCTP_ERROR_STALE_COOKIE
));
2249 return SCTP_DISPOSITION_DELETE_TCB
;
2252 err
= (sctp_errhdr_t
*)(chunk
->skb
->data
);
2254 /* When calculating the time extension, an implementation
2255 * SHOULD use the RTT information measured based on the
2256 * previous COOKIE ECHO / ERROR exchange, and should add no
2257 * more than 1 second beyond the measured RTT, due to long
2258 * State Cookie lifetimes making the endpoint more subject to
2260 * Measure of Staleness's unit is usec. (1/1000000 sec)
2261 * Suggested Cookie Life-span Increment's unit is msec.
2263 * In general, if you use the suggested cookie life, the value
2264 * found in the field of measure of staleness should be doubled
2265 * to give ample time to retransmit the new cookie and thus
2266 * yield a higher probability of success on the reattempt.
2268 stale
= ntohl(*(__be32
*)((u8
*)err
+ sizeof(sctp_errhdr_t
)));
2269 stale
= (stale
* 2) / 1000;
2271 bht
.param_hdr
.type
= SCTP_PARAM_COOKIE_PRESERVATIVE
;
2272 bht
.param_hdr
.length
= htons(sizeof(bht
));
2273 bht
.lifespan_increment
= htonl(stale
);
2275 /* Build that new INIT chunk. */
2276 bp
= (struct sctp_bind_addr
*) &asoc
->base
.bind_addr
;
2277 reply
= sctp_make_init(asoc
, bp
, GFP_ATOMIC
, sizeof(bht
));
2281 sctp_addto_chunk(reply
, sizeof(bht
), &bht
);
2283 /* Clear peer's init_tag cached in assoc as we are sending a new INIT */
2284 sctp_add_cmd_sf(commands
, SCTP_CMD_CLEAR_INIT_TAG
, SCTP_NULL());
2286 /* Stop pending T3-rtx and heartbeat timers */
2287 sctp_add_cmd_sf(commands
, SCTP_CMD_T3_RTX_TIMERS_STOP
, SCTP_NULL());
2288 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_STOP
, SCTP_NULL());
2290 /* Delete non-primary peer ip addresses since we are transitioning
2291 * back to the COOKIE-WAIT state
2293 sctp_add_cmd_sf(commands
, SCTP_CMD_DEL_NON_PRIMARY
, SCTP_NULL());
2295 /* If we've sent any data bundled with COOKIE-ECHO we will need to
2298 sctp_add_cmd_sf(commands
, SCTP_CMD_T1_RETRAN
,
2299 SCTP_TRANSPORT(asoc
->peer
.primary_path
));
2301 /* Cast away the const modifier, as we want to just
2302 * rerun it through as a sideffect.
2304 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_COUNTER_INC
, SCTP_NULL());
2306 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
2307 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
2308 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
2309 SCTP_STATE(SCTP_STATE_COOKIE_WAIT
));
2310 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
2311 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
2313 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
2315 return SCTP_DISPOSITION_CONSUME
;
2318 return SCTP_DISPOSITION_NOMEM
;
2325 * After checking the Verification Tag, the receiving endpoint shall
2326 * remove the association from its record, and shall report the
2327 * termination to its upper layer.
2329 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
2330 * B) Rules for packet carrying ABORT:
2332 * - The endpoint shall always fill in the Verification Tag field of the
2333 * outbound packet with the destination endpoint's tag value if it
2336 * - If the ABORT is sent in response to an OOTB packet, the endpoint
2337 * MUST follow the procedure described in Section 8.4.
2339 * - The receiver MUST accept the packet if the Verification Tag
2340 * matches either its own tag, OR the tag of its peer. Otherwise, the
2341 * receiver MUST silently discard the packet and take no further
2345 * (endpoint, asoc, chunk)
2348 * (asoc, reply_msg, msg_up, timers, counters)
2350 * The return value is the disposition of the chunk.
2352 sctp_disposition_t
sctp_sf_do_9_1_abort(const struct sctp_endpoint
*ep
,
2353 const struct sctp_association
*asoc
,
2354 const sctp_subtype_t type
,
2356 sctp_cmd_seq_t
*commands
)
2358 struct sctp_chunk
*chunk
= arg
;
2360 if (!sctp_vtag_verify_either(chunk
, asoc
))
2361 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2363 /* Make sure that the ABORT chunk has a valid length.
2364 * Since this is an ABORT chunk, we have to discard it
2365 * because of the following text:
2366 * RFC 2960, Section 3.3.7
2367 * If an endpoint receives an ABORT with a format error or for an
2368 * association that doesn't exist, it MUST silently discard it.
2369 * Becasue the length is "invalid", we can't really discard just
2370 * as we do not know its true length. So, to be safe, discard the
2373 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_abort_chunk_t
)))
2374 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2376 /* ADD-IP: Special case for ABORT chunks
2377 * F4) One special consideration is that ABORT Chunks arriving
2378 * destined to the IP address being deleted MUST be
2379 * ignored (see Section 5.3.1 for further details).
2381 if (SCTP_ADDR_DEL
==
2382 sctp_bind_addr_state(&asoc
->base
.bind_addr
, &chunk
->dest
))
2383 return sctp_sf_discard_chunk(ep
, asoc
, type
, arg
, commands
);
2385 return __sctp_sf_do_9_1_abort(ep
, asoc
, type
, arg
, commands
);
2388 static sctp_disposition_t
__sctp_sf_do_9_1_abort(const struct sctp_endpoint
*ep
,
2389 const struct sctp_association
*asoc
,
2390 const sctp_subtype_t type
,
2392 sctp_cmd_seq_t
*commands
)
2394 struct sctp_chunk
*chunk
= arg
;
2396 __be16 error
= SCTP_ERROR_NO_ERROR
;
2398 /* See if we have an error cause code in the chunk. */
2399 len
= ntohs(chunk
->chunk_hdr
->length
);
2400 if (len
>= sizeof(struct sctp_chunkhdr
) + sizeof(struct sctp_errhdr
))
2401 error
= ((sctp_errhdr_t
*)chunk
->skb
->data
)->cause
;
2403 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
, SCTP_ERROR(ECONNRESET
));
2404 /* ASSOC_FAILED will DELETE_TCB. */
2405 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
, SCTP_PERR(error
));
2406 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
2407 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
2409 return SCTP_DISPOSITION_ABORT
;
2413 * Process an ABORT. (COOKIE-WAIT state)
2415 * See sctp_sf_do_9_1_abort() above.
2417 sctp_disposition_t
sctp_sf_cookie_wait_abort(const struct sctp_endpoint
*ep
,
2418 const struct sctp_association
*asoc
,
2419 const sctp_subtype_t type
,
2421 sctp_cmd_seq_t
*commands
)
2423 struct sctp_chunk
*chunk
= arg
;
2425 __be16 error
= SCTP_ERROR_NO_ERROR
;
2427 if (!sctp_vtag_verify_either(chunk
, asoc
))
2428 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2430 /* Make sure that the ABORT chunk has a valid length.
2431 * Since this is an ABORT chunk, we have to discard it
2432 * because of the following text:
2433 * RFC 2960, Section 3.3.7
2434 * If an endpoint receives an ABORT with a format error or for an
2435 * association that doesn't exist, it MUST silently discard it.
2436 * Becasue the length is "invalid", we can't really discard just
2437 * as we do not know its true length. So, to be safe, discard the
2440 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_abort_chunk_t
)))
2441 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2443 /* See if we have an error cause code in the chunk. */
2444 len
= ntohs(chunk
->chunk_hdr
->length
);
2445 if (len
>= sizeof(struct sctp_chunkhdr
) + sizeof(struct sctp_errhdr
))
2446 error
= ((sctp_errhdr_t
*)chunk
->skb
->data
)->cause
;
2448 return sctp_stop_t1_and_abort(commands
, error
, ECONNREFUSED
, asoc
,
2453 * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state)
2455 sctp_disposition_t
sctp_sf_cookie_wait_icmp_abort(const struct sctp_endpoint
*ep
,
2456 const struct sctp_association
*asoc
,
2457 const sctp_subtype_t type
,
2459 sctp_cmd_seq_t
*commands
)
2461 return sctp_stop_t1_and_abort(commands
, SCTP_ERROR_NO_ERROR
,
2463 (struct sctp_transport
*)arg
);
2467 * Process an ABORT. (COOKIE-ECHOED state)
2469 sctp_disposition_t
sctp_sf_cookie_echoed_abort(const struct sctp_endpoint
*ep
,
2470 const struct sctp_association
*asoc
,
2471 const sctp_subtype_t type
,
2473 sctp_cmd_seq_t
*commands
)
2475 /* There is a single T1 timer, so we should be able to use
2476 * common function with the COOKIE-WAIT state.
2478 return sctp_sf_cookie_wait_abort(ep
, asoc
, type
, arg
, commands
);
2482 * Stop T1 timer and abort association with "INIT failed".
2484 * This is common code called by several sctp_sf_*_abort() functions above.
2486 static sctp_disposition_t
sctp_stop_t1_and_abort(sctp_cmd_seq_t
*commands
,
2487 __be16 error
, int sk_err
,
2488 const struct sctp_association
*asoc
,
2489 struct sctp_transport
*transport
)
2491 SCTP_DEBUG_PRINTK("ABORT received (INIT).\n");
2492 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
2493 SCTP_STATE(SCTP_STATE_CLOSED
));
2494 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
2495 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
2496 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
2497 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
, SCTP_ERROR(sk_err
));
2498 /* CMD_INIT_FAILED will DELETE_TCB. */
2499 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
2501 return SCTP_DISPOSITION_ABORT
;
2505 * sctp_sf_do_9_2_shut
2508 * Upon the reception of the SHUTDOWN, the peer endpoint shall
2509 * - enter the SHUTDOWN-RECEIVED state,
2511 * - stop accepting new data from its SCTP user
2513 * - verify, by checking the Cumulative TSN Ack field of the chunk,
2514 * that all its outstanding DATA chunks have been received by the
2517 * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT
2518 * send a SHUTDOWN in response to a ULP request. And should discard
2519 * subsequent SHUTDOWN chunks.
2521 * If there are still outstanding DATA chunks left, the SHUTDOWN
2522 * receiver shall continue to follow normal data transmission
2523 * procedures defined in Section 6 until all outstanding DATA chunks
2524 * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept
2525 * new data from its SCTP user.
2527 * Verification Tag: 8.5 Verification Tag [Normal verification]
2530 * (endpoint, asoc, chunk)
2533 * (asoc, reply_msg, msg_up, timers, counters)
2535 * The return value is the disposition of the chunk.
2537 sctp_disposition_t
sctp_sf_do_9_2_shutdown(const struct sctp_endpoint
*ep
,
2538 const struct sctp_association
*asoc
,
2539 const sctp_subtype_t type
,
2541 sctp_cmd_seq_t
*commands
)
2543 struct sctp_chunk
*chunk
= arg
;
2544 sctp_shutdownhdr_t
*sdh
;
2545 sctp_disposition_t disposition
;
2546 struct sctp_ulpevent
*ev
;
2548 if (!sctp_vtag_verify(chunk
, asoc
))
2549 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2551 /* Make sure that the SHUTDOWN chunk has a valid length. */
2552 if (!sctp_chunk_length_valid(chunk
,
2553 sizeof(struct sctp_shutdown_chunk_t
)))
2554 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2557 /* Convert the elaborate header. */
2558 sdh
= (sctp_shutdownhdr_t
*)chunk
->skb
->data
;
2559 skb_pull(chunk
->skb
, sizeof(sctp_shutdownhdr_t
));
2560 chunk
->subh
.shutdown_hdr
= sdh
;
2562 /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT
2563 * When a peer sends a SHUTDOWN, SCTP delivers this notification to
2564 * inform the application that it should cease sending data.
2566 ev
= sctp_ulpevent_make_shutdown_event(asoc
, 0, GFP_ATOMIC
);
2568 disposition
= SCTP_DISPOSITION_NOMEM
;
2571 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
2573 /* Upon the reception of the SHUTDOWN, the peer endpoint shall
2574 * - enter the SHUTDOWN-RECEIVED state,
2575 * - stop accepting new data from its SCTP user
2577 * [This is implicit in the new state.]
2579 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
2580 SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED
));
2581 disposition
= SCTP_DISPOSITION_CONSUME
;
2583 if (sctp_outq_is_empty(&asoc
->outqueue
)) {
2584 disposition
= sctp_sf_do_9_2_shutdown_ack(ep
, asoc
, type
,
2588 if (SCTP_DISPOSITION_NOMEM
== disposition
)
2591 /* - verify, by checking the Cumulative TSN Ack field of the
2592 * chunk, that all its outstanding DATA chunks have been
2593 * received by the SHUTDOWN sender.
2595 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_CTSN
,
2596 SCTP_BE32(chunk
->subh
.shutdown_hdr
->cum_tsn_ack
));
2603 * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk
2604 * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination
2605 * transport addresses (either in the IP addresses or in the INIT chunk)
2606 * that belong to this association, it should discard the INIT chunk and
2607 * retransmit the SHUTDOWN ACK chunk.
2609 sctp_disposition_t
sctp_sf_do_9_2_reshutack(const struct sctp_endpoint
*ep
,
2610 const struct sctp_association
*asoc
,
2611 const sctp_subtype_t type
,
2613 sctp_cmd_seq_t
*commands
)
2615 struct sctp_chunk
*chunk
= (struct sctp_chunk
*) arg
;
2616 struct sctp_chunk
*reply
;
2618 /* Make sure that the chunk has a valid length */
2619 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
2620 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2623 /* Since we are not going to really process this INIT, there
2624 * is no point in verifying chunk boundries. Just generate
2627 reply
= sctp_make_shutdown_ack(asoc
, chunk
);
2631 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
2632 * the T2-SHUTDOWN timer.
2634 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T2
, SCTP_CHUNK(reply
));
2636 /* and restart the T2-shutdown timer. */
2637 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
2638 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
2640 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
2642 return SCTP_DISPOSITION_CONSUME
;
2644 return SCTP_DISPOSITION_NOMEM
;
2648 * sctp_sf_do_ecn_cwr
2650 * Section: Appendix A: Explicit Congestion Notification
2654 * RFC 2481 details a specific bit for a sender to send in the header of
2655 * its next outbound TCP segment to indicate to its peer that it has
2656 * reduced its congestion window. This is termed the CWR bit. For
2657 * SCTP the same indication is made by including the CWR chunk.
2658 * This chunk contains one data element, i.e. the TSN number that
2659 * was sent in the ECNE chunk. This element represents the lowest
2660 * TSN number in the datagram that was originally marked with the
2663 * Verification Tag: 8.5 Verification Tag [Normal verification]
2665 * (endpoint, asoc, chunk)
2668 * (asoc, reply_msg, msg_up, timers, counters)
2670 * The return value is the disposition of the chunk.
2672 sctp_disposition_t
sctp_sf_do_ecn_cwr(const struct sctp_endpoint
*ep
,
2673 const struct sctp_association
*asoc
,
2674 const sctp_subtype_t type
,
2676 sctp_cmd_seq_t
*commands
)
2679 struct sctp_chunk
*chunk
= arg
;
2682 if (!sctp_vtag_verify(chunk
, asoc
))
2683 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2685 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_ecne_chunk_t
)))
2686 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2689 cwr
= (sctp_cwrhdr_t
*) chunk
->skb
->data
;
2690 skb_pull(chunk
->skb
, sizeof(sctp_cwrhdr_t
));
2692 lowest_tsn
= ntohl(cwr
->lowest_tsn
);
2694 /* Does this CWR ack the last sent congestion notification? */
2695 if (TSN_lte(asoc
->last_ecne_tsn
, lowest_tsn
)) {
2696 /* Stop sending ECNE. */
2697 sctp_add_cmd_sf(commands
,
2699 SCTP_U32(lowest_tsn
));
2701 return SCTP_DISPOSITION_CONSUME
;
2707 * Section: Appendix A: Explicit Congestion Notification
2711 * RFC 2481 details a specific bit for a receiver to send back in its
2712 * TCP acknowledgements to notify the sender of the Congestion
2713 * Experienced (CE) bit having arrived from the network. For SCTP this
2714 * same indication is made by including the ECNE chunk. This chunk
2715 * contains one data element, i.e. the lowest TSN associated with the IP
2716 * datagram marked with the CE bit.....
2718 * Verification Tag: 8.5 Verification Tag [Normal verification]
2720 * (endpoint, asoc, chunk)
2723 * (asoc, reply_msg, msg_up, timers, counters)
2725 * The return value is the disposition of the chunk.
2727 sctp_disposition_t
sctp_sf_do_ecne(const struct sctp_endpoint
*ep
,
2728 const struct sctp_association
*asoc
,
2729 const sctp_subtype_t type
,
2731 sctp_cmd_seq_t
*commands
)
2733 sctp_ecnehdr_t
*ecne
;
2734 struct sctp_chunk
*chunk
= arg
;
2736 if (!sctp_vtag_verify(chunk
, asoc
))
2737 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2739 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_ecne_chunk_t
)))
2740 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2743 ecne
= (sctp_ecnehdr_t
*) chunk
->skb
->data
;
2744 skb_pull(chunk
->skb
, sizeof(sctp_ecnehdr_t
));
2746 /* If this is a newer ECNE than the last CWR packet we sent out */
2747 sctp_add_cmd_sf(commands
, SCTP_CMD_ECN_ECNE
,
2748 SCTP_U32(ntohl(ecne
->lowest_tsn
)));
2750 return SCTP_DISPOSITION_CONSUME
;
2754 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
2756 * The SCTP endpoint MUST always acknowledge the reception of each valid
2759 * The guidelines on delayed acknowledgement algorithm specified in
2760 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
2761 * acknowledgement SHOULD be generated for at least every second packet
2762 * (not every second DATA chunk) received, and SHOULD be generated within
2763 * 200 ms of the arrival of any unacknowledged DATA chunk. In some
2764 * situations it may be beneficial for an SCTP transmitter to be more
2765 * conservative than the algorithms detailed in this document allow.
2766 * However, an SCTP transmitter MUST NOT be more aggressive than the
2767 * following algorithms allow.
2769 * A SCTP receiver MUST NOT generate more than one SACK for every
2770 * incoming packet, other than to update the offered window as the
2771 * receiving application consumes new data.
2773 * Verification Tag: 8.5 Verification Tag [Normal verification]
2776 * (endpoint, asoc, chunk)
2779 * (asoc, reply_msg, msg_up, timers, counters)
2781 * The return value is the disposition of the chunk.
2783 sctp_disposition_t
sctp_sf_eat_data_6_2(const struct sctp_endpoint
*ep
,
2784 const struct sctp_association
*asoc
,
2785 const sctp_subtype_t type
,
2787 sctp_cmd_seq_t
*commands
)
2789 struct sctp_chunk
*chunk
= arg
;
2792 if (!sctp_vtag_verify(chunk
, asoc
)) {
2793 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
2795 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2798 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_data_chunk_t
)))
2799 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2802 error
= sctp_eat_data(asoc
, chunk
, commands
);
2804 case SCTP_IERROR_NO_ERROR
:
2806 case SCTP_IERROR_HIGH_TSN
:
2807 case SCTP_IERROR_BAD_STREAM
:
2808 SCTP_INC_STATS(SCTP_MIB_IN_DATA_CHUNK_DISCARDS
);
2809 goto discard_noforce
;
2810 case SCTP_IERROR_DUP_TSN
:
2811 case SCTP_IERROR_IGNORE_TSN
:
2812 SCTP_INC_STATS(SCTP_MIB_IN_DATA_CHUNK_DISCARDS
);
2814 case SCTP_IERROR_NO_DATA
:
2820 if (asoc
->autoclose
) {
2821 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
2822 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
2825 /* If this is the last chunk in a packet, we need to count it
2826 * toward sack generation. Note that we need to SACK every
2827 * OTHER packet containing data chunks, EVEN IF WE DISCARD
2828 * THEM. We elect to NOT generate SACK's if the chunk fails
2829 * the verification tag test.
2831 * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2833 * The SCTP endpoint MUST always acknowledge the reception of
2834 * each valid DATA chunk.
2836 * The guidelines on delayed acknowledgement algorithm
2837 * specified in Section 4.2 of [RFC2581] SHOULD be followed.
2838 * Specifically, an acknowledgement SHOULD be generated for at
2839 * least every second packet (not every second DATA chunk)
2840 * received, and SHOULD be generated within 200 ms of the
2841 * arrival of any unacknowledged DATA chunk. In some
2842 * situations it may be beneficial for an SCTP transmitter to
2843 * be more conservative than the algorithms detailed in this
2844 * document allow. However, an SCTP transmitter MUST NOT be
2845 * more aggressive than the following algorithms allow.
2847 if (chunk
->end_of_packet
)
2848 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_NOFORCE());
2850 return SCTP_DISPOSITION_CONSUME
;
2853 /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
2855 * When a packet arrives with duplicate DATA chunk(s) and with
2856 * no new DATA chunk(s), the endpoint MUST immediately send a
2857 * SACK with no delay. If a packet arrives with duplicate
2858 * DATA chunk(s) bundled with new DATA chunks, the endpoint
2859 * MAY immediately send a SACK. Normally receipt of duplicate
2860 * DATA chunks will occur when the original SACK chunk was lost
2861 * and the peer's RTO has expired. The duplicate TSN number(s)
2862 * SHOULD be reported in the SACK as duplicate.
2864 /* In our case, we split the MAY SACK advice up whether or not
2865 * the last chunk is a duplicate.'
2867 if (chunk
->end_of_packet
)
2868 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_FORCE());
2869 return SCTP_DISPOSITION_DISCARD
;
2872 if (chunk
->end_of_packet
)
2873 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_NOFORCE());
2875 return SCTP_DISPOSITION_DISCARD
;
2877 return SCTP_DISPOSITION_CONSUME
;
2882 * sctp_sf_eat_data_fast_4_4
2885 * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received
2886 * DATA chunks without delay.
2888 * Verification Tag: 8.5 Verification Tag [Normal verification]
2890 * (endpoint, asoc, chunk)
2893 * (asoc, reply_msg, msg_up, timers, counters)
2895 * The return value is the disposition of the chunk.
2897 sctp_disposition_t
sctp_sf_eat_data_fast_4_4(const struct sctp_endpoint
*ep
,
2898 const struct sctp_association
*asoc
,
2899 const sctp_subtype_t type
,
2901 sctp_cmd_seq_t
*commands
)
2903 struct sctp_chunk
*chunk
= arg
;
2906 if (!sctp_vtag_verify(chunk
, asoc
)) {
2907 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
2909 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2912 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_data_chunk_t
)))
2913 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
2916 error
= sctp_eat_data(asoc
, chunk
, commands
);
2918 case SCTP_IERROR_NO_ERROR
:
2919 case SCTP_IERROR_HIGH_TSN
:
2920 case SCTP_IERROR_DUP_TSN
:
2921 case SCTP_IERROR_IGNORE_TSN
:
2922 case SCTP_IERROR_BAD_STREAM
:
2924 case SCTP_IERROR_NO_DATA
:
2930 /* Go a head and force a SACK, since we are shutting down. */
2932 /* Implementor's Guide.
2934 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
2935 * respond to each received packet containing one or more DATA chunk(s)
2936 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
2938 if (chunk
->end_of_packet
) {
2939 /* We must delay the chunk creation since the cumulative
2940 * TSN has not been updated yet.
2942 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SHUTDOWN
, SCTP_NULL());
2943 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_FORCE());
2944 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
2945 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
2949 return SCTP_DISPOSITION_CONSUME
;
2953 * Section: 6.2 Processing a Received SACK
2954 * D) Any time a SACK arrives, the endpoint performs the following:
2956 * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point,
2957 * then drop the SACK. Since Cumulative TSN Ack is monotonically
2958 * increasing, a SACK whose Cumulative TSN Ack is less than the
2959 * Cumulative TSN Ack Point indicates an out-of-order SACK.
2961 * ii) Set rwnd equal to the newly received a_rwnd minus the number
2962 * of bytes still outstanding after processing the Cumulative TSN Ack
2963 * and the Gap Ack Blocks.
2965 * iii) If the SACK is missing a TSN that was previously
2966 * acknowledged via a Gap Ack Block (e.g., the data receiver
2967 * reneged on the data), then mark the corresponding DATA chunk
2968 * as available for retransmit: Mark it as missing for fast
2969 * retransmit as described in Section 7.2.4 and if no retransmit
2970 * timer is running for the destination address to which the DATA
2971 * chunk was originally transmitted, then T3-rtx is started for
2972 * that destination address.
2974 * Verification Tag: 8.5 Verification Tag [Normal verification]
2977 * (endpoint, asoc, chunk)
2980 * (asoc, reply_msg, msg_up, timers, counters)
2982 * The return value is the disposition of the chunk.
2984 sctp_disposition_t
sctp_sf_eat_sack_6_2(const struct sctp_endpoint
*ep
,
2985 const struct sctp_association
*asoc
,
2986 const sctp_subtype_t type
,
2988 sctp_cmd_seq_t
*commands
)
2990 struct sctp_chunk
*chunk
= arg
;
2991 sctp_sackhdr_t
*sackh
;
2994 if (!sctp_vtag_verify(chunk
, asoc
))
2995 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
2997 /* Make sure that the SACK chunk has a valid length. */
2998 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_sack_chunk_t
)))
2999 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3002 /* Pull the SACK chunk from the data buffer */
3003 sackh
= sctp_sm_pull_sack(chunk
);
3004 /* Was this a bogus SACK? */
3006 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3007 chunk
->subh
.sack_hdr
= sackh
;
3008 ctsn
= ntohl(sackh
->cum_tsn_ack
);
3010 /* i) If Cumulative TSN Ack is less than the Cumulative TSN
3011 * Ack Point, then drop the SACK. Since Cumulative TSN
3012 * Ack is monotonically increasing, a SACK whose
3013 * Cumulative TSN Ack is less than the Cumulative TSN Ack
3014 * Point indicates an out-of-order SACK.
3016 if (TSN_lt(ctsn
, asoc
->ctsn_ack_point
)) {
3017 SCTP_DEBUG_PRINTK("ctsn %x\n", ctsn
);
3018 SCTP_DEBUG_PRINTK("ctsn_ack_point %x\n", asoc
->ctsn_ack_point
);
3019 return SCTP_DISPOSITION_DISCARD
;
3022 /* If Cumulative TSN Ack beyond the max tsn currently
3023 * send, terminating the association and respond to the
3024 * sender with an ABORT.
3026 if (!TSN_lt(ctsn
, asoc
->next_tsn
))
3027 return sctp_sf_violation_ctsn(ep
, asoc
, type
, arg
, commands
);
3029 /* Return this SACK for further processing. */
3030 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_SACK
, SCTP_SACKH(sackh
));
3032 /* Note: We do the rest of the work on the PROCESS_SACK
3035 return SCTP_DISPOSITION_CONSUME
;
3039 * Generate an ABORT in response to a packet.
3041 * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41
3043 * 8) The receiver should respond to the sender of the OOTB packet with
3044 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3045 * MUST fill in the Verification Tag field of the outbound packet
3046 * with the value found in the Verification Tag field of the OOTB
3047 * packet and set the T-bit in the Chunk Flags to indicate that the
3048 * Verification Tag is reflected. After sending this ABORT, the
3049 * receiver of the OOTB packet shall discard the OOTB packet and take
3050 * no further action.
3054 * The return value is the disposition of the chunk.
3056 static sctp_disposition_t
sctp_sf_tabort_8_4_8(const struct sctp_endpoint
*ep
,
3057 const struct sctp_association
*asoc
,
3058 const sctp_subtype_t type
,
3060 sctp_cmd_seq_t
*commands
)
3062 struct sctp_packet
*packet
= NULL
;
3063 struct sctp_chunk
*chunk
= arg
;
3064 struct sctp_chunk
*abort
;
3066 packet
= sctp_ootb_pkt_new(asoc
, chunk
);
3069 /* Make an ABORT. The T bit will be set if the asoc
3072 abort
= sctp_make_abort(asoc
, chunk
, 0);
3074 sctp_ootb_pkt_free(packet
);
3075 return SCTP_DISPOSITION_NOMEM
;
3078 /* Reflect vtag if T-Bit is set */
3079 if (sctp_test_T_bit(abort
))
3080 packet
->vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
3082 /* Set the skb to the belonging sock for accounting. */
3083 abort
->skb
->sk
= ep
->base
.sk
;
3085 sctp_packet_append_chunk(packet
, abort
);
3087 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
3088 SCTP_PACKET(packet
));
3090 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
3092 sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3093 return SCTP_DISPOSITION_CONSUME
;
3096 return SCTP_DISPOSITION_NOMEM
;
3100 * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR
3101 * event as ULP notification for each cause included in the chunk.
3103 * API 5.3.1.3 - SCTP_REMOTE_ERROR
3105 * The return value is the disposition of the chunk.
3107 sctp_disposition_t
sctp_sf_operr_notify(const struct sctp_endpoint
*ep
,
3108 const struct sctp_association
*asoc
,
3109 const sctp_subtype_t type
,
3111 sctp_cmd_seq_t
*commands
)
3113 struct sctp_chunk
*chunk
= arg
;
3114 struct sctp_ulpevent
*ev
;
3116 if (!sctp_vtag_verify(chunk
, asoc
))
3117 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3119 /* Make sure that the ERROR chunk has a valid length. */
3120 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_operr_chunk_t
)))
3121 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3124 while (chunk
->chunk_end
> chunk
->skb
->data
) {
3125 ev
= sctp_ulpevent_make_remote_error(asoc
, chunk
, 0,
3130 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
3132 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_OPERR
,
3135 return SCTP_DISPOSITION_CONSUME
;
3138 return SCTP_DISPOSITION_NOMEM
;
3142 * Process an inbound SHUTDOWN ACK.
3145 * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3146 * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its
3147 * peer, and remove all record of the association.
3149 * The return value is the disposition.
3151 sctp_disposition_t
sctp_sf_do_9_2_final(const struct sctp_endpoint
*ep
,
3152 const struct sctp_association
*asoc
,
3153 const sctp_subtype_t type
,
3155 sctp_cmd_seq_t
*commands
)
3157 struct sctp_chunk
*chunk
= arg
;
3158 struct sctp_chunk
*reply
;
3159 struct sctp_ulpevent
*ev
;
3161 if (!sctp_vtag_verify(chunk
, asoc
))
3162 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3164 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3165 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
3166 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3168 /* 10.2 H) SHUTDOWN COMPLETE notification
3170 * When SCTP completes the shutdown procedures (section 9.2) this
3171 * notification is passed to the upper layer.
3173 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_SHUTDOWN_COMP
,
3174 0, 0, 0, NULL
, GFP_ATOMIC
);
3178 /* ...send a SHUTDOWN COMPLETE chunk to its peer, */
3179 reply
= sctp_make_shutdown_complete(asoc
, chunk
);
3183 /* Do all the commands now (after allocation), so that we
3184 * have consistent state if memory allocation failes
3186 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
3188 /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3189 * stop the T2-shutdown timer,
3191 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3192 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
3194 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3195 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
3197 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
3198 SCTP_STATE(SCTP_STATE_CLOSED
));
3199 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS
);
3200 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
3201 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
3203 /* ...and remove all record of the association. */
3204 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
3205 return SCTP_DISPOSITION_DELETE_TCB
;
3208 sctp_ulpevent_free(ev
);
3210 return SCTP_DISPOSITION_NOMEM
;
3214 * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41.
3216 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3217 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3218 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3219 * packet must fill in the Verification Tag field of the outbound
3220 * packet with the Verification Tag received in the SHUTDOWN ACK and
3221 * set the T-bit in the Chunk Flags to indicate that the Verification
3224 * 8) The receiver should respond to the sender of the OOTB packet with
3225 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3226 * MUST fill in the Verification Tag field of the outbound packet
3227 * with the value found in the Verification Tag field of the OOTB
3228 * packet and set the T-bit in the Chunk Flags to indicate that the
3229 * Verification Tag is reflected. After sending this ABORT, the
3230 * receiver of the OOTB packet shall discard the OOTB packet and take
3231 * no further action.
3233 sctp_disposition_t
sctp_sf_ootb(const struct sctp_endpoint
*ep
,
3234 const struct sctp_association
*asoc
,
3235 const sctp_subtype_t type
,
3237 sctp_cmd_seq_t
*commands
)
3239 struct sctp_chunk
*chunk
= arg
;
3240 struct sk_buff
*skb
= chunk
->skb
;
3241 sctp_chunkhdr_t
*ch
;
3243 int ootb_shut_ack
= 0;
3245 SCTP_INC_STATS(SCTP_MIB_OUTOFBLUES
);
3247 ch
= (sctp_chunkhdr_t
*) chunk
->chunk_hdr
;
3249 /* Report violation if the chunk is less then minimal */
3250 if (ntohs(ch
->length
) < sizeof(sctp_chunkhdr_t
))
3251 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3254 /* Now that we know we at least have a chunk header,
3255 * do things that are type appropriate.
3257 if (SCTP_CID_SHUTDOWN_ACK
== ch
->type
)
3260 /* RFC 2960, Section 3.3.7
3261 * Moreover, under any circumstances, an endpoint that
3262 * receives an ABORT MUST NOT respond to that ABORT by
3263 * sending an ABORT of its own.
3265 if (SCTP_CID_ABORT
== ch
->type
)
3266 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3268 /* Report violation if chunk len overflows */
3269 ch_end
= ((__u8
*)ch
) + WORD_ROUND(ntohs(ch
->length
));
3270 if (ch_end
> skb_tail_pointer(skb
))
3271 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3274 ch
= (sctp_chunkhdr_t
*) ch_end
;
3275 } while (ch_end
< skb_tail_pointer(skb
));
3278 return sctp_sf_shut_8_4_5(ep
, asoc
, type
, arg
, commands
);
3280 return sctp_sf_tabort_8_4_8(ep
, asoc
, type
, arg
, commands
);
3284 * Handle an "Out of the blue" SHUTDOWN ACK.
3286 * Section: 8.4 5, sctpimpguide 2.41.
3288 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3289 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3290 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3291 * packet must fill in the Verification Tag field of the outbound
3292 * packet with the Verification Tag received in the SHUTDOWN ACK and
3293 * set the T-bit in the Chunk Flags to indicate that the Verification
3297 * (endpoint, asoc, type, arg, commands)
3300 * (sctp_disposition_t)
3302 * The return value is the disposition of the chunk.
3304 static sctp_disposition_t
sctp_sf_shut_8_4_5(const struct sctp_endpoint
*ep
,
3305 const struct sctp_association
*asoc
,
3306 const sctp_subtype_t type
,
3308 sctp_cmd_seq_t
*commands
)
3310 struct sctp_packet
*packet
= NULL
;
3311 struct sctp_chunk
*chunk
= arg
;
3312 struct sctp_chunk
*shut
;
3314 packet
= sctp_ootb_pkt_new(asoc
, chunk
);
3317 /* Make an SHUTDOWN_COMPLETE.
3318 * The T bit will be set if the asoc is NULL.
3320 shut
= sctp_make_shutdown_complete(asoc
, chunk
);
3322 sctp_ootb_pkt_free(packet
);
3323 return SCTP_DISPOSITION_NOMEM
;
3326 /* Reflect vtag if T-Bit is set */
3327 if (sctp_test_T_bit(shut
))
3328 packet
->vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
3330 /* Set the skb to the belonging sock for accounting. */
3331 shut
->skb
->sk
= ep
->base
.sk
;
3333 sctp_packet_append_chunk(packet
, shut
);
3335 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
3336 SCTP_PACKET(packet
));
3338 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
3340 /* If the chunk length is invalid, we don't want to process
3341 * the reset of the packet.
3343 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
3344 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3346 /* We need to discard the rest of the packet to prevent
3347 * potential bomming attacks from additional bundled chunks.
3348 * This is documented in SCTP Threats ID.
3350 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3353 return SCTP_DISPOSITION_NOMEM
;
3357 * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state.
3359 * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK
3360 * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the
3361 * procedures in section 8.4 SHOULD be followed, in other words it
3362 * should be treated as an Out Of The Blue packet.
3363 * [This means that we do NOT check the Verification Tag on these
3367 sctp_disposition_t
sctp_sf_do_8_5_1_E_sa(const struct sctp_endpoint
*ep
,
3368 const struct sctp_association
*asoc
,
3369 const sctp_subtype_t type
,
3371 sctp_cmd_seq_t
*commands
)
3373 struct sctp_chunk
*chunk
= arg
;
3375 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3376 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
3377 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3380 /* Although we do have an association in this case, it corresponds
3381 * to a restarted association. So the packet is treated as an OOTB
3382 * packet and the state function that handles OOTB SHUTDOWN_ACK is
3383 * called with a NULL association.
3385 return sctp_sf_shut_8_4_5(ep
, NULL
, type
, arg
, commands
);
3388 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */
3389 sctp_disposition_t
sctp_sf_do_asconf(const struct sctp_endpoint
*ep
,
3390 const struct sctp_association
*asoc
,
3391 const sctp_subtype_t type
, void *arg
,
3392 sctp_cmd_seq_t
*commands
)
3394 struct sctp_chunk
*chunk
= arg
;
3395 struct sctp_chunk
*asconf_ack
= NULL
;
3396 struct sctp_paramhdr
*err_param
= NULL
;
3397 sctp_addiphdr_t
*hdr
;
3398 union sctp_addr_param
*addr_param
;
3402 if (!sctp_vtag_verify(chunk
, asoc
)) {
3403 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3405 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3408 /* ADD-IP: Section 4.1.1
3409 * This chunk MUST be sent in an authenticated way by using
3410 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3411 * is received unauthenticated it MUST be silently discarded as
3412 * described in [I-D.ietf-tsvwg-sctp-auth].
3414 if (!sctp_addip_noauth
&& !chunk
->auth
)
3415 return sctp_sf_discard_chunk(ep
, asoc
, type
, arg
, commands
);
3417 /* Make sure that the ASCONF ADDIP chunk has a valid length. */
3418 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_addip_chunk_t
)))
3419 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3422 hdr
= (sctp_addiphdr_t
*)chunk
->skb
->data
;
3423 serial
= ntohl(hdr
->serial
);
3425 addr_param
= (union sctp_addr_param
*)hdr
->params
;
3426 length
= ntohs(addr_param
->p
.length
);
3427 if (length
< sizeof(sctp_paramhdr_t
))
3428 return sctp_sf_violation_paramlen(ep
, asoc
, type
, arg
,
3429 (void *)addr_param
, commands
);
3431 /* Verify the ASCONF chunk before processing it. */
3432 if (!sctp_verify_asconf(asoc
,
3433 (sctp_paramhdr_t
*)((void *)addr_param
+ length
),
3434 (void *)chunk
->chunk_end
,
3436 return sctp_sf_violation_paramlen(ep
, asoc
, type
, arg
,
3437 (void *)err_param
, commands
);
3439 /* ADDIP 5.2 E1) Compare the value of the serial number to the value
3440 * the endpoint stored in a new association variable
3441 * 'Peer-Serial-Number'.
3443 if (serial
== asoc
->peer
.addip_serial
+ 1) {
3444 /* If this is the first instance of ASCONF in the packet,
3445 * we can clean our old ASCONF-ACKs.
3447 if (!chunk
->has_asconf
)
3448 sctp_assoc_clean_asconf_ack_cache(asoc
);
3450 /* ADDIP 5.2 E4) When the Sequence Number matches the next one
3451 * expected, process the ASCONF as described below and after
3452 * processing the ASCONF Chunk, append an ASCONF-ACK Chunk to
3453 * the response packet and cache a copy of it (in the event it
3454 * later needs to be retransmitted).
3456 * Essentially, do V1-V5.
3458 asconf_ack
= sctp_process_asconf((struct sctp_association
*)
3461 return SCTP_DISPOSITION_NOMEM
;
3462 } else if (serial
< asoc
->peer
.addip_serial
+ 1) {
3464 * If the value found in the Sequence Number is less than the
3465 * ('Peer- Sequence-Number' + 1), simply skip to the next
3466 * ASCONF, and include in the outbound response packet
3467 * any previously cached ASCONF-ACK response that was
3468 * sent and saved that matches the Sequence Number of the
3469 * ASCONF. Note: It is possible that no cached ASCONF-ACK
3470 * Chunk exists. This will occur when an older ASCONF
3471 * arrives out of order. In such a case, the receiver
3472 * should skip the ASCONF Chunk and not include ASCONF-ACK
3473 * Chunk for that chunk.
3475 asconf_ack
= sctp_assoc_lookup_asconf_ack(asoc
, hdr
->serial
);
3477 return SCTP_DISPOSITION_DISCARD
;
3479 /* ADDIP 5.2 E5) Otherwise, the ASCONF Chunk is discarded since
3480 * it must be either a stale packet or from an attacker.
3482 return SCTP_DISPOSITION_DISCARD
;
3485 /* ADDIP 5.2 E6) The destination address of the SCTP packet
3486 * containing the ASCONF-ACK Chunks MUST be the source address of
3487 * the SCTP packet that held the ASCONF Chunks.
3489 * To do this properly, we'll set the destination address of the chunk
3490 * and at the transmit time, will try look up the transport to use.
3491 * Since ASCONFs may be bundled, the correct transport may not be
3492 * created untill we process the entire packet, thus this workaround.
3494 asconf_ack
->dest
= chunk
->source
;
3495 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(asconf_ack
));
3497 return SCTP_DISPOSITION_CONSUME
;
3501 * ADDIP Section 4.3 General rules for address manipulation
3502 * When building TLV parameters for the ASCONF Chunk that will add or
3503 * delete IP addresses the D0 to D13 rules should be applied:
3505 sctp_disposition_t
sctp_sf_do_asconf_ack(const struct sctp_endpoint
*ep
,
3506 const struct sctp_association
*asoc
,
3507 const sctp_subtype_t type
, void *arg
,
3508 sctp_cmd_seq_t
*commands
)
3510 struct sctp_chunk
*asconf_ack
= arg
;
3511 struct sctp_chunk
*last_asconf
= asoc
->addip_last_asconf
;
3512 struct sctp_chunk
*abort
;
3513 struct sctp_paramhdr
*err_param
= NULL
;
3514 sctp_addiphdr_t
*addip_hdr
;
3515 __u32 sent_serial
, rcvd_serial
;
3517 if (!sctp_vtag_verify(asconf_ack
, asoc
)) {
3518 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3520 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3523 /* ADD-IP, Section 4.1.2:
3524 * This chunk MUST be sent in an authenticated way by using
3525 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3526 * is received unauthenticated it MUST be silently discarded as
3527 * described in [I-D.ietf-tsvwg-sctp-auth].
3529 if (!sctp_addip_noauth
&& !asconf_ack
->auth
)
3530 return sctp_sf_discard_chunk(ep
, asoc
, type
, arg
, commands
);
3532 /* Make sure that the ADDIP chunk has a valid length. */
3533 if (!sctp_chunk_length_valid(asconf_ack
, sizeof(sctp_addip_chunk_t
)))
3534 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3537 addip_hdr
= (sctp_addiphdr_t
*)asconf_ack
->skb
->data
;
3538 rcvd_serial
= ntohl(addip_hdr
->serial
);
3540 /* Verify the ASCONF-ACK chunk before processing it. */
3541 if (!sctp_verify_asconf(asoc
,
3542 (sctp_paramhdr_t
*)addip_hdr
->params
,
3543 (void *)asconf_ack
->chunk_end
,
3545 return sctp_sf_violation_paramlen(ep
, asoc
, type
, arg
,
3546 (void *)err_param
, commands
);
3549 addip_hdr
= (sctp_addiphdr_t
*)last_asconf
->subh
.addip_hdr
;
3550 sent_serial
= ntohl(addip_hdr
->serial
);
3552 sent_serial
= asoc
->addip_serial
- 1;
3555 /* D0) If an endpoint receives an ASCONF-ACK that is greater than or
3556 * equal to the next serial number to be used but no ASCONF chunk is
3557 * outstanding the endpoint MUST ABORT the association. Note that a
3558 * sequence number is greater than if it is no more than 2^^31-1
3559 * larger than the current sequence number (using serial arithmetic).
3561 if (ADDIP_SERIAL_gte(rcvd_serial
, sent_serial
+ 1) &&
3562 !(asoc
->addip_last_asconf
)) {
3563 abort
= sctp_make_abort(asoc
, asconf_ack
,
3564 sizeof(sctp_errhdr_t
));
3566 sctp_init_cause(abort
, SCTP_ERROR_ASCONF_ACK
, 0);
3567 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
3570 /* We are going to ABORT, so we might as well stop
3571 * processing the rest of the chunks in the packet.
3573 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3574 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
3575 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
,SCTP_NULL());
3576 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
3577 SCTP_ERROR(ECONNABORTED
));
3578 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
3579 SCTP_PERR(SCTP_ERROR_ASCONF_ACK
));
3580 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
3581 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
3582 return SCTP_DISPOSITION_ABORT
;
3585 if ((rcvd_serial
== sent_serial
) && asoc
->addip_last_asconf
) {
3586 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3587 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
3589 if (!sctp_process_asconf_ack((struct sctp_association
*)asoc
,
3591 return SCTP_DISPOSITION_CONSUME
;
3593 abort
= sctp_make_abort(asoc
, asconf_ack
,
3594 sizeof(sctp_errhdr_t
));
3596 sctp_init_cause(abort
, SCTP_ERROR_RSRC_LOW
, 0);
3597 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
3600 /* We are going to ABORT, so we might as well stop
3601 * processing the rest of the chunks in the packet.
3603 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
,SCTP_NULL());
3604 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
3605 SCTP_ERROR(ECONNABORTED
));
3606 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
3607 SCTP_PERR(SCTP_ERROR_ASCONF_ACK
));
3608 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
3609 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
3610 return SCTP_DISPOSITION_ABORT
;
3613 return SCTP_DISPOSITION_DISCARD
;
3617 * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP
3619 * When a FORWARD TSN chunk arrives, the data receiver MUST first update
3620 * its cumulative TSN point to the value carried in the FORWARD TSN
3621 * chunk, and then MUST further advance its cumulative TSN point locally
3623 * After the above processing, the data receiver MUST stop reporting any
3624 * missing TSNs earlier than or equal to the new cumulative TSN point.
3626 * Verification Tag: 8.5 Verification Tag [Normal verification]
3628 * The return value is the disposition of the chunk.
3630 sctp_disposition_t
sctp_sf_eat_fwd_tsn(const struct sctp_endpoint
*ep
,
3631 const struct sctp_association
*asoc
,
3632 const sctp_subtype_t type
,
3634 sctp_cmd_seq_t
*commands
)
3636 struct sctp_chunk
*chunk
= arg
;
3637 struct sctp_fwdtsn_hdr
*fwdtsn_hdr
;
3641 if (!sctp_vtag_verify(chunk
, asoc
)) {
3642 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3644 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3647 /* Make sure that the FORWARD_TSN chunk has valid length. */
3648 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_fwdtsn_chunk
)))
3649 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3652 fwdtsn_hdr
= (struct sctp_fwdtsn_hdr
*)chunk
->skb
->data
;
3653 chunk
->subh
.fwdtsn_hdr
= fwdtsn_hdr
;
3654 len
= ntohs(chunk
->chunk_hdr
->length
);
3655 len
-= sizeof(struct sctp_chunkhdr
);
3656 skb_pull(chunk
->skb
, len
);
3658 tsn
= ntohl(fwdtsn_hdr
->new_cum_tsn
);
3659 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __func__
, tsn
);
3661 /* The TSN is too high--silently discard the chunk and count on it
3662 * getting retransmitted later.
3664 if (sctp_tsnmap_check(&asoc
->peer
.tsn_map
, tsn
) < 0)
3665 goto discard_noforce
;
3667 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_FWDTSN
, SCTP_U32(tsn
));
3668 if (len
> sizeof(struct sctp_fwdtsn_hdr
))
3669 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_FWDTSN
,
3672 /* Count this as receiving DATA. */
3673 if (asoc
->autoclose
) {
3674 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
3675 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
3678 /* FIXME: For now send a SACK, but DATA processing may
3681 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_NOFORCE());
3683 return SCTP_DISPOSITION_CONSUME
;
3686 return SCTP_DISPOSITION_DISCARD
;
3689 sctp_disposition_t
sctp_sf_eat_fwd_tsn_fast(
3690 const struct sctp_endpoint
*ep
,
3691 const struct sctp_association
*asoc
,
3692 const sctp_subtype_t type
,
3694 sctp_cmd_seq_t
*commands
)
3696 struct sctp_chunk
*chunk
= arg
;
3697 struct sctp_fwdtsn_hdr
*fwdtsn_hdr
;
3701 if (!sctp_vtag_verify(chunk
, asoc
)) {
3702 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3704 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3707 /* Make sure that the FORWARD_TSN chunk has a valid length. */
3708 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_fwdtsn_chunk
)))
3709 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3712 fwdtsn_hdr
= (struct sctp_fwdtsn_hdr
*)chunk
->skb
->data
;
3713 chunk
->subh
.fwdtsn_hdr
= fwdtsn_hdr
;
3714 len
= ntohs(chunk
->chunk_hdr
->length
);
3715 len
-= sizeof(struct sctp_chunkhdr
);
3716 skb_pull(chunk
->skb
, len
);
3718 tsn
= ntohl(fwdtsn_hdr
->new_cum_tsn
);
3719 SCTP_DEBUG_PRINTK("%s: TSN 0x%x.\n", __func__
, tsn
);
3721 /* The TSN is too high--silently discard the chunk and count on it
3722 * getting retransmitted later.
3724 if (sctp_tsnmap_check(&asoc
->peer
.tsn_map
, tsn
) < 0)
3727 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_FWDTSN
, SCTP_U32(tsn
));
3728 if (len
> sizeof(struct sctp_fwdtsn_hdr
))
3729 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_FWDTSN
,
3732 /* Go a head and force a SACK, since we are shutting down. */
3734 /* Implementor's Guide.
3736 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3737 * respond to each received packet containing one or more DATA chunk(s)
3738 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3740 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SHUTDOWN
, SCTP_NULL());
3741 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_FORCE());
3742 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
3743 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
3745 return SCTP_DISPOSITION_CONSUME
;
3749 * SCTP-AUTH Section 6.3 Receving authenticated chukns
3751 * The receiver MUST use the HMAC algorithm indicated in the HMAC
3752 * Identifier field. If this algorithm was not specified by the
3753 * receiver in the HMAC-ALGO parameter in the INIT or INIT-ACK chunk
3754 * during association setup, the AUTH chunk and all chunks after it MUST
3755 * be discarded and an ERROR chunk SHOULD be sent with the error cause
3756 * defined in Section 4.1.
3758 * If an endpoint with no shared key receives a Shared Key Identifier
3759 * other than 0, it MUST silently discard all authenticated chunks. If
3760 * the endpoint has at least one endpoint pair shared key for the peer,
3761 * it MUST use the key specified by the Shared Key Identifier if a
3762 * key has been configured for that Shared Key Identifier. If no
3763 * endpoint pair shared key has been configured for that Shared Key
3764 * Identifier, all authenticated chunks MUST be silently discarded.
3766 * Verification Tag: 8.5 Verification Tag [Normal verification]
3768 * The return value is the disposition of the chunk.
3770 static sctp_ierror_t
sctp_sf_authenticate(const struct sctp_endpoint
*ep
,
3771 const struct sctp_association
*asoc
,
3772 const sctp_subtype_t type
,
3773 struct sctp_chunk
*chunk
)
3775 struct sctp_authhdr
*auth_hdr
;
3776 struct sctp_hmac
*hmac
;
3777 unsigned int sig_len
;
3782 /* Pull in the auth header, so we can do some more verification */
3783 auth_hdr
= (struct sctp_authhdr
*)chunk
->skb
->data
;
3784 chunk
->subh
.auth_hdr
= auth_hdr
;
3785 skb_pull(chunk
->skb
, sizeof(struct sctp_authhdr
));
3787 /* Make sure that we suport the HMAC algorithm from the auth
3790 if (!sctp_auth_asoc_verify_hmac_id(asoc
, auth_hdr
->hmac_id
))
3791 return SCTP_IERROR_AUTH_BAD_HMAC
;
3793 /* Make sure that the provided shared key identifier has been
3796 key_id
= ntohs(auth_hdr
->shkey_id
);
3797 if (key_id
!= asoc
->active_key_id
&& !sctp_auth_get_shkey(asoc
, key_id
))
3798 return SCTP_IERROR_AUTH_BAD_KEYID
;
3801 /* Make sure that the length of the signature matches what
3804 sig_len
= ntohs(chunk
->chunk_hdr
->length
) - sizeof(sctp_auth_chunk_t
);
3805 hmac
= sctp_auth_get_hmac(ntohs(auth_hdr
->hmac_id
));
3806 if (sig_len
!= hmac
->hmac_len
)
3807 return SCTP_IERROR_PROTO_VIOLATION
;
3809 /* Now that we've done validation checks, we can compute and
3810 * verify the hmac. The steps involved are:
3811 * 1. Save the digest from the chunk.
3812 * 2. Zero out the digest in the chunk.
3813 * 3. Compute the new digest
3814 * 4. Compare saved and new digests.
3816 digest
= auth_hdr
->hmac
;
3817 skb_pull(chunk
->skb
, sig_len
);
3819 save_digest
= kmemdup(digest
, sig_len
, GFP_ATOMIC
);
3823 memset(digest
, 0, sig_len
);
3825 sctp_auth_calculate_hmac(asoc
, chunk
->skb
,
3826 (struct sctp_auth_chunk
*)chunk
->chunk_hdr
,
3829 /* Discard the packet if the digests do not match */
3830 if (memcmp(save_digest
, digest
, sig_len
)) {
3832 return SCTP_IERROR_BAD_SIG
;
3838 return SCTP_IERROR_NO_ERROR
;
3840 return SCTP_IERROR_NOMEM
;
3843 sctp_disposition_t
sctp_sf_eat_auth(const struct sctp_endpoint
*ep
,
3844 const struct sctp_association
*asoc
,
3845 const sctp_subtype_t type
,
3847 sctp_cmd_seq_t
*commands
)
3849 struct sctp_authhdr
*auth_hdr
;
3850 struct sctp_chunk
*chunk
= arg
;
3851 struct sctp_chunk
*err_chunk
;
3852 sctp_ierror_t error
;
3854 /* Make sure that the peer has AUTH capable */
3855 if (!asoc
->peer
.auth_capable
)
3856 return sctp_sf_unk_chunk(ep
, asoc
, type
, arg
, commands
);
3858 if (!sctp_vtag_verify(chunk
, asoc
)) {
3859 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3861 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3864 /* Make sure that the AUTH chunk has valid length. */
3865 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_auth_chunk
)))
3866 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3869 auth_hdr
= (struct sctp_authhdr
*)chunk
->skb
->data
;
3870 error
= sctp_sf_authenticate(ep
, asoc
, type
, chunk
);
3872 case SCTP_IERROR_AUTH_BAD_HMAC
:
3873 /* Generate the ERROR chunk and discard the rest
3876 err_chunk
= sctp_make_op_error(asoc
, chunk
,
3877 SCTP_ERROR_UNSUP_HMAC
,
3881 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
3882 SCTP_CHUNK(err_chunk
));
3885 case SCTP_IERROR_AUTH_BAD_KEYID
:
3886 case SCTP_IERROR_BAD_SIG
:
3887 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3889 case SCTP_IERROR_PROTO_VIOLATION
:
3890 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3893 case SCTP_IERROR_NOMEM
:
3894 return SCTP_DISPOSITION_NOMEM
;
3899 if (asoc
->active_key_id
!= ntohs(auth_hdr
->shkey_id
)) {
3900 struct sctp_ulpevent
*ev
;
3902 ev
= sctp_ulpevent_make_authkey(asoc
, ntohs(auth_hdr
->shkey_id
),
3903 SCTP_AUTH_NEWKEY
, GFP_ATOMIC
);
3908 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
3912 return SCTP_DISPOSITION_CONSUME
;
3916 * Process an unknown chunk.
3918 * Section: 3.2. Also, 2.1 in the implementor's guide.
3920 * Chunk Types are encoded such that the highest-order two bits specify
3921 * the action that must be taken if the processing endpoint does not
3922 * recognize the Chunk Type.
3924 * 00 - Stop processing this SCTP packet and discard it, do not process
3925 * any further chunks within it.
3927 * 01 - Stop processing this SCTP packet and discard it, do not process
3928 * any further chunks within it, and report the unrecognized
3929 * chunk in an 'Unrecognized Chunk Type'.
3931 * 10 - Skip this chunk and continue processing.
3933 * 11 - Skip this chunk and continue processing, but report in an ERROR
3934 * Chunk using the 'Unrecognized Chunk Type' cause of error.
3936 * The return value is the disposition of the chunk.
3938 sctp_disposition_t
sctp_sf_unk_chunk(const struct sctp_endpoint
*ep
,
3939 const struct sctp_association
*asoc
,
3940 const sctp_subtype_t type
,
3942 sctp_cmd_seq_t
*commands
)
3944 struct sctp_chunk
*unk_chunk
= arg
;
3945 struct sctp_chunk
*err_chunk
;
3946 sctp_chunkhdr_t
*hdr
;
3948 SCTP_DEBUG_PRINTK("Processing the unknown chunk id %d.\n", type
.chunk
);
3950 if (!sctp_vtag_verify(unk_chunk
, asoc
))
3951 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3953 /* Make sure that the chunk has a valid length.
3954 * Since we don't know the chunk type, we use a general
3955 * chunkhdr structure to make a comparison.
3957 if (!sctp_chunk_length_valid(unk_chunk
, sizeof(sctp_chunkhdr_t
)))
3958 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
3961 switch (type
.chunk
& SCTP_CID_ACTION_MASK
) {
3962 case SCTP_CID_ACTION_DISCARD
:
3963 /* Discard the packet. */
3964 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3966 case SCTP_CID_ACTION_DISCARD_ERR
:
3967 /* Generate an ERROR chunk as response. */
3968 hdr
= unk_chunk
->chunk_hdr
;
3969 err_chunk
= sctp_make_op_error(asoc
, unk_chunk
,
3970 SCTP_ERROR_UNKNOWN_CHUNK
, hdr
,
3971 WORD_ROUND(ntohs(hdr
->length
)));
3973 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
3974 SCTP_CHUNK(err_chunk
));
3977 /* Discard the packet. */
3978 sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
3979 return SCTP_DISPOSITION_CONSUME
;
3981 case SCTP_CID_ACTION_SKIP
:
3982 /* Skip the chunk. */
3983 return SCTP_DISPOSITION_DISCARD
;
3985 case SCTP_CID_ACTION_SKIP_ERR
:
3986 /* Generate an ERROR chunk as response. */
3987 hdr
= unk_chunk
->chunk_hdr
;
3988 err_chunk
= sctp_make_op_error(asoc
, unk_chunk
,
3989 SCTP_ERROR_UNKNOWN_CHUNK
, hdr
,
3990 WORD_ROUND(ntohs(hdr
->length
)));
3992 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
3993 SCTP_CHUNK(err_chunk
));
3995 /* Skip the chunk. */
3996 return SCTP_DISPOSITION_CONSUME
;
4002 return SCTP_DISPOSITION_DISCARD
;
4006 * Discard the chunk.
4008 * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2
4009 * [Too numerous to mention...]
4010 * Verification Tag: No verification needed.
4012 * (endpoint, asoc, chunk)
4015 * (asoc, reply_msg, msg_up, timers, counters)
4017 * The return value is the disposition of the chunk.
4019 sctp_disposition_t
sctp_sf_discard_chunk(const struct sctp_endpoint
*ep
,
4020 const struct sctp_association
*asoc
,
4021 const sctp_subtype_t type
,
4023 sctp_cmd_seq_t
*commands
)
4025 struct sctp_chunk
*chunk
= arg
;
4027 /* Make sure that the chunk has a valid length.
4028 * Since we don't know the chunk type, we use a general
4029 * chunkhdr structure to make a comparison.
4031 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
4032 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
4035 SCTP_DEBUG_PRINTK("Chunk %d is discarded\n", type
.chunk
);
4036 return SCTP_DISPOSITION_DISCARD
;
4040 * Discard the whole packet.
4044 * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST
4045 * silently discard the OOTB packet and take no further action.
4047 * Verification Tag: No verification necessary
4050 * (endpoint, asoc, chunk)
4053 * (asoc, reply_msg, msg_up, timers, counters)
4055 * The return value is the disposition of the chunk.
4057 sctp_disposition_t
sctp_sf_pdiscard(const struct sctp_endpoint
*ep
,
4058 const struct sctp_association
*asoc
,
4059 const sctp_subtype_t type
,
4061 sctp_cmd_seq_t
*commands
)
4063 SCTP_INC_STATS(SCTP_MIB_IN_PKT_DISCARDS
);
4064 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
, SCTP_NULL());
4066 return SCTP_DISPOSITION_CONSUME
;
4071 * The other end is violating protocol.
4073 * Section: Not specified
4074 * Verification Tag: Not specified
4076 * (endpoint, asoc, chunk)
4079 * (asoc, reply_msg, msg_up, timers, counters)
4081 * We simply tag the chunk as a violation. The state machine will log
4082 * the violation and continue.
4084 sctp_disposition_t
sctp_sf_violation(const struct sctp_endpoint
*ep
,
4085 const struct sctp_association
*asoc
,
4086 const sctp_subtype_t type
,
4088 sctp_cmd_seq_t
*commands
)
4090 struct sctp_chunk
*chunk
= arg
;
4092 /* Make sure that the chunk has a valid length. */
4093 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_chunkhdr_t
)))
4094 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
4097 return SCTP_DISPOSITION_VIOLATION
;
4101 * Common function to handle a protocol violation.
4103 static sctp_disposition_t
sctp_sf_abort_violation(
4104 const struct sctp_endpoint
*ep
,
4105 const struct sctp_association
*asoc
,
4107 sctp_cmd_seq_t
*commands
,
4108 const __u8
*payload
,
4109 const size_t paylen
)
4111 struct sctp_packet
*packet
= NULL
;
4112 struct sctp_chunk
*chunk
= arg
;
4113 struct sctp_chunk
*abort
= NULL
;
4115 /* SCTP-AUTH, Section 6.3:
4116 * It should be noted that if the receiver wants to tear
4117 * down an association in an authenticated way only, the
4118 * handling of malformed packets should not result in
4119 * tearing down the association.
4121 * This means that if we only want to abort associations
4122 * in an authenticated way (i.e AUTH+ABORT), then we
4123 * can't destroy this association just becuase the packet
4126 if (sctp_auth_recv_cid(SCTP_CID_ABORT
, asoc
))
4129 /* Make the abort chunk. */
4130 abort
= sctp_make_abort_violation(asoc
, chunk
, payload
, paylen
);
4135 /* Treat INIT-ACK as a special case during COOKIE-WAIT. */
4136 if (chunk
->chunk_hdr
->type
== SCTP_CID_INIT_ACK
&&
4137 !asoc
->peer
.i
.init_tag
) {
4138 sctp_initack_chunk_t
*initack
;
4140 initack
= (sctp_initack_chunk_t
*)chunk
->chunk_hdr
;
4141 if (!sctp_chunk_length_valid(chunk
,
4142 sizeof(sctp_initack_chunk_t
)))
4143 abort
->chunk_hdr
->flags
|= SCTP_CHUNK_FLAG_T
;
4145 unsigned int inittag
;
4147 inittag
= ntohl(initack
->init_hdr
.init_tag
);
4148 sctp_add_cmd_sf(commands
, SCTP_CMD_UPDATE_INITTAG
,
4153 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(abort
));
4154 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
4156 if (asoc
->state
<= SCTP_STATE_COOKIE_ECHOED
) {
4157 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4158 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
4159 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
4160 SCTP_ERROR(ECONNREFUSED
));
4161 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
4162 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION
));
4164 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
4165 SCTP_ERROR(ECONNABORTED
));
4166 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
4167 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION
));
4168 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
4171 packet
= sctp_ootb_pkt_new(asoc
, chunk
);
4176 if (sctp_test_T_bit(abort
))
4177 packet
->vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
4179 abort
->skb
->sk
= ep
->base
.sk
;
4181 sctp_packet_append_chunk(packet
, abort
);
4183 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
4184 SCTP_PACKET(packet
));
4186 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
4190 sctp_sf_pdiscard(ep
, asoc
, SCTP_ST_CHUNK(0), arg
, commands
);
4192 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
4194 return SCTP_DISPOSITION_ABORT
;
4197 sctp_chunk_free(abort
);
4199 return SCTP_DISPOSITION_NOMEM
;
4203 * Handle a protocol violation when the chunk length is invalid.
4204 * "Invalid" length is identified as smaller then the minimal length a
4205 * given chunk can be. For example, a SACK chunk has invalid length
4206 * if it's length is set to be smaller then the size of sctp_sack_chunk_t.
4208 * We inform the other end by sending an ABORT with a Protocol Violation
4211 * Section: Not specified
4212 * Verification Tag: Nothing to do
4214 * (endpoint, asoc, chunk)
4217 * (reply_msg, msg_up, counters)
4219 * Generate an ABORT chunk and terminate the association.
4221 static sctp_disposition_t
sctp_sf_violation_chunklen(
4222 const struct sctp_endpoint
*ep
,
4223 const struct sctp_association
*asoc
,
4224 const sctp_subtype_t type
,
4226 sctp_cmd_seq_t
*commands
)
4228 static const char err_str
[]="The following chunk had invalid length:";
4230 return sctp_sf_abort_violation(ep
, asoc
, arg
, commands
, err_str
,
4235 * Handle a protocol violation when the parameter length is invalid.
4236 * "Invalid" length is identified as smaller then the minimal length a
4237 * given parameter can be.
4239 static sctp_disposition_t
sctp_sf_violation_paramlen(
4240 const struct sctp_endpoint
*ep
,
4241 const struct sctp_association
*asoc
,
4242 const sctp_subtype_t type
,
4243 void *arg
, void *ext
,
4244 sctp_cmd_seq_t
*commands
)
4246 struct sctp_chunk
*chunk
= arg
;
4247 struct sctp_paramhdr
*param
= ext
;
4248 struct sctp_chunk
*abort
= NULL
;
4250 if (sctp_auth_recv_cid(SCTP_CID_ABORT
, asoc
))
4253 /* Make the abort chunk. */
4254 abort
= sctp_make_violation_paramlen(asoc
, chunk
, param
);
4258 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(abort
));
4259 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
4261 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
4262 SCTP_ERROR(ECONNABORTED
));
4263 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
4264 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION
));
4265 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
4268 sctp_sf_pdiscard(ep
, asoc
, SCTP_ST_CHUNK(0), arg
, commands
);
4270 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
4272 return SCTP_DISPOSITION_ABORT
;
4274 return SCTP_DISPOSITION_NOMEM
;
4277 /* Handle a protocol violation when the peer trying to advance the
4278 * cumulative tsn ack to a point beyond the max tsn currently sent.
4280 * We inform the other end by sending an ABORT with a Protocol Violation
4283 static sctp_disposition_t
sctp_sf_violation_ctsn(
4284 const struct sctp_endpoint
*ep
,
4285 const struct sctp_association
*asoc
,
4286 const sctp_subtype_t type
,
4288 sctp_cmd_seq_t
*commands
)
4290 static const char err_str
[]="The cumulative tsn ack beyond the max tsn currently sent:";
4292 return sctp_sf_abort_violation(ep
, asoc
, arg
, commands
, err_str
,
4296 /* Handle protocol violation of an invalid chunk bundling. For example,
4297 * when we have an association and we recieve bundled INIT-ACK, or
4298 * SHUDOWN-COMPLETE, our peer is clearly violationg the "MUST NOT bundle"
4299 * statement from the specs. Additinally, there might be an attacker
4300 * on the path and we may not want to continue this communication.
4302 static sctp_disposition_t
sctp_sf_violation_chunk(
4303 const struct sctp_endpoint
*ep
,
4304 const struct sctp_association
*asoc
,
4305 const sctp_subtype_t type
,
4307 sctp_cmd_seq_t
*commands
)
4309 static const char err_str
[]="The following chunk violates protocol:";
4312 return sctp_sf_violation(ep
, asoc
, type
, arg
, commands
);
4314 return sctp_sf_abort_violation(ep
, asoc
, arg
, commands
, err_str
,
4317 /***************************************************************************
4318 * These are the state functions for handling primitive (Section 10) events.
4319 ***************************************************************************/
4321 * sctp_sf_do_prm_asoc
4323 * Section: 10.1 ULP-to-SCTP
4326 * Format: ASSOCIATE(local SCTP instance name, destination transport addr,
4327 * outbound stream count)
4328 * -> association id [,destination transport addr list] [,outbound stream
4331 * This primitive allows the upper layer to initiate an association to a
4332 * specific peer endpoint.
4334 * The peer endpoint shall be specified by one of the transport addresses
4335 * which defines the endpoint (see Section 1.4). If the local SCTP
4336 * instance has not been initialized, the ASSOCIATE is considered an
4338 * [This is not relevant for the kernel implementation since we do all
4339 * initialization at boot time. It we hadn't initialized we wouldn't
4340 * get anywhere near this code.]
4342 * An association id, which is a local handle to the SCTP association,
4343 * will be returned on successful establishment of the association. If
4344 * SCTP is not able to open an SCTP association with the peer endpoint,
4345 * an error is returned.
4346 * [In the kernel implementation, the struct sctp_association needs to
4347 * be created BEFORE causing this primitive to run.]
4349 * Other association parameters may be returned, including the
4350 * complete destination transport addresses of the peer as well as the
4351 * outbound stream count of the local endpoint. One of the transport
4352 * address from the returned destination addresses will be selected by
4353 * the local endpoint as default primary path for sending SCTP packets
4354 * to this peer. The returned "destination transport addr list" can
4355 * be used by the ULP to change the default primary path or to force
4356 * sending a packet to a specific transport address. [All of this
4357 * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING
4360 * Mandatory attributes:
4362 * o local SCTP instance name - obtained from the INITIALIZE operation.
4363 * [This is the argument asoc.]
4364 * o destination transport addr - specified as one of the transport
4365 * addresses of the peer endpoint with which the association is to be
4367 * [This is asoc->peer.active_path.]
4368 * o outbound stream count - the number of outbound streams the ULP
4369 * would like to open towards this peer endpoint.
4370 * [BUG: This is not currently implemented.]
4371 * Optional attributes:
4375 * The return value is a disposition.
4377 sctp_disposition_t
sctp_sf_do_prm_asoc(const struct sctp_endpoint
*ep
,
4378 const struct sctp_association
*asoc
,
4379 const sctp_subtype_t type
,
4381 sctp_cmd_seq_t
*commands
)
4383 struct sctp_chunk
*repl
;
4384 struct sctp_association
* my_asoc
;
4386 /* The comment below says that we enter COOKIE-WAIT AFTER
4387 * sending the INIT, but that doesn't actually work in our
4390 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
4391 SCTP_STATE(SCTP_STATE_COOKIE_WAIT
));
4393 /* RFC 2960 5.1 Normal Establishment of an Association
4395 * A) "A" first sends an INIT chunk to "Z". In the INIT, "A"
4396 * must provide its Verification Tag (Tag_A) in the Initiate
4397 * Tag field. Tag_A SHOULD be a random number in the range of
4398 * 1 to 4294967295 (see 5.3.1 for Tag value selection). ...
4401 repl
= sctp_make_init(asoc
, &asoc
->base
.bind_addr
, GFP_ATOMIC
, 0);
4405 /* Cast away the const modifier, as we want to just
4406 * rerun it through as a sideffect.
4408 my_asoc
= (struct sctp_association
*)asoc
;
4409 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(my_asoc
));
4411 /* Choose transport for INIT. */
4412 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_CHOOSE_TRANSPORT
,
4415 /* After sending the INIT, "A" starts the T1-init timer and
4416 * enters the COOKIE-WAIT state.
4418 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
4419 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
4420 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
4421 return SCTP_DISPOSITION_CONSUME
;
4424 return SCTP_DISPOSITION_NOMEM
;
4428 * Process the SEND primitive.
4430 * Section: 10.1 ULP-to-SCTP
4433 * Format: SEND(association id, buffer address, byte count [,context]
4434 * [,stream id] [,life time] [,destination transport address]
4435 * [,unorder flag] [,no-bundle flag] [,payload protocol-id] )
4438 * This is the main method to send user data via SCTP.
4440 * Mandatory attributes:
4442 * o association id - local handle to the SCTP association
4444 * o buffer address - the location where the user message to be
4445 * transmitted is stored;
4447 * o byte count - The size of the user data in number of bytes;
4449 * Optional attributes:
4451 * o context - an optional 32 bit integer that will be carried in the
4452 * sending failure notification to the ULP if the transportation of
4453 * this User Message fails.
4455 * o stream id - to indicate which stream to send the data on. If not
4456 * specified, stream 0 will be used.
4458 * o life time - specifies the life time of the user data. The user data
4459 * will not be sent by SCTP after the life time expires. This
4460 * parameter can be used to avoid efforts to transmit stale
4461 * user messages. SCTP notifies the ULP if the data cannot be
4462 * initiated to transport (i.e. sent to the destination via SCTP's
4463 * send primitive) within the life time variable. However, the
4464 * user data will be transmitted if SCTP has attempted to transmit a
4465 * chunk before the life time expired.
4467 * o destination transport address - specified as one of the destination
4468 * transport addresses of the peer endpoint to which this packet
4469 * should be sent. Whenever possible, SCTP should use this destination
4470 * transport address for sending the packets, instead of the current
4473 * o unorder flag - this flag, if present, indicates that the user
4474 * would like the data delivered in an unordered fashion to the peer
4475 * (i.e., the U flag is set to 1 on all DATA chunks carrying this
4478 * o no-bundle flag - instructs SCTP not to bundle this user data with
4479 * other outbound DATA chunks. SCTP MAY still bundle even when
4480 * this flag is present, when faced with network congestion.
4482 * o payload protocol-id - A 32 bit unsigned integer that is to be
4483 * passed to the peer indicating the type of payload protocol data
4484 * being transmitted. This value is passed as opaque data by SCTP.
4486 * The return value is the disposition.
4488 sctp_disposition_t
sctp_sf_do_prm_send(const struct sctp_endpoint
*ep
,
4489 const struct sctp_association
*asoc
,
4490 const sctp_subtype_t type
,
4492 sctp_cmd_seq_t
*commands
)
4494 struct sctp_chunk
*chunk
= arg
;
4496 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(chunk
));
4497 return SCTP_DISPOSITION_CONSUME
;
4501 * Process the SHUTDOWN primitive.
4506 * Format: SHUTDOWN(association id)
4509 * Gracefully closes an association. Any locally queued user data
4510 * will be delivered to the peer. The association will be terminated only
4511 * after the peer acknowledges all the SCTP packets sent. A success code
4512 * will be returned on successful termination of the association. If
4513 * attempting to terminate the association results in a failure, an error
4514 * code shall be returned.
4516 * Mandatory attributes:
4518 * o association id - local handle to the SCTP association
4520 * Optional attributes:
4524 * The return value is the disposition.
4526 sctp_disposition_t
sctp_sf_do_9_2_prm_shutdown(
4527 const struct sctp_endpoint
*ep
,
4528 const struct sctp_association
*asoc
,
4529 const sctp_subtype_t type
,
4531 sctp_cmd_seq_t
*commands
)
4535 /* From 9.2 Shutdown of an Association
4536 * Upon receipt of the SHUTDOWN primitive from its upper
4537 * layer, the endpoint enters SHUTDOWN-PENDING state and
4538 * remains there until all outstanding data has been
4539 * acknowledged by its peer. The endpoint accepts no new data
4540 * from its upper layer, but retransmits data to the far end
4541 * if necessary to fill gaps.
4543 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
4544 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING
));
4546 /* sctpimpguide-05 Section 2.12.2
4547 * The sender of the SHUTDOWN MAY also start an overall guard timer
4548 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
4550 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
4551 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
4553 disposition
= SCTP_DISPOSITION_CONSUME
;
4554 if (sctp_outq_is_empty(&asoc
->outqueue
)) {
4555 disposition
= sctp_sf_do_9_2_start_shutdown(ep
, asoc
, type
,
4562 * Process the ABORT primitive.
4567 * Format: Abort(association id [, cause code])
4570 * Ungracefully closes an association. Any locally queued user data
4571 * will be discarded and an ABORT chunk is sent to the peer. A success code
4572 * will be returned on successful abortion of the association. If
4573 * attempting to abort the association results in a failure, an error
4574 * code shall be returned.
4576 * Mandatory attributes:
4578 * o association id - local handle to the SCTP association
4580 * Optional attributes:
4582 * o cause code - reason of the abort to be passed to the peer
4586 * The return value is the disposition.
4588 sctp_disposition_t
sctp_sf_do_9_1_prm_abort(
4589 const struct sctp_endpoint
*ep
,
4590 const struct sctp_association
*asoc
,
4591 const sctp_subtype_t type
,
4593 sctp_cmd_seq_t
*commands
)
4595 /* From 9.1 Abort of an Association
4596 * Upon receipt of the ABORT primitive from its upper
4597 * layer, the endpoint enters CLOSED state and
4598 * discard all outstanding data has been
4599 * acknowledged by its peer. The endpoint accepts no new data
4600 * from its upper layer, but retransmits data to the far end
4601 * if necessary to fill gaps.
4603 struct sctp_chunk
*abort
= arg
;
4604 sctp_disposition_t retval
;
4606 retval
= SCTP_DISPOSITION_CONSUME
;
4608 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(abort
));
4610 /* Even if we can't send the ABORT due to low memory delete the
4611 * TCB. This is a departure from our typical NOMEM handling.
4614 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
4615 SCTP_ERROR(ECONNABORTED
));
4616 /* Delete the established association. */
4617 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
4618 SCTP_PERR(SCTP_ERROR_USER_ABORT
));
4620 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
4621 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
4626 /* We tried an illegal operation on an association which is closed. */
4627 sctp_disposition_t
sctp_sf_error_closed(const struct sctp_endpoint
*ep
,
4628 const struct sctp_association
*asoc
,
4629 const sctp_subtype_t type
,
4631 sctp_cmd_seq_t
*commands
)
4633 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_ERROR
, SCTP_ERROR(-EINVAL
));
4634 return SCTP_DISPOSITION_CONSUME
;
4637 /* We tried an illegal operation on an association which is shutting
4640 sctp_disposition_t
sctp_sf_error_shutdown(const struct sctp_endpoint
*ep
,
4641 const struct sctp_association
*asoc
,
4642 const sctp_subtype_t type
,
4644 sctp_cmd_seq_t
*commands
)
4646 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_ERROR
,
4647 SCTP_ERROR(-ESHUTDOWN
));
4648 return SCTP_DISPOSITION_CONSUME
;
4652 * sctp_cookie_wait_prm_shutdown
4654 * Section: 4 Note: 2
4659 * The RFC does not explicitly address this issue, but is the route through the
4660 * state table when someone issues a shutdown while in COOKIE_WAIT state.
4665 sctp_disposition_t
sctp_sf_cookie_wait_prm_shutdown(
4666 const struct sctp_endpoint
*ep
,
4667 const struct sctp_association
*asoc
,
4668 const sctp_subtype_t type
,
4670 sctp_cmd_seq_t
*commands
)
4672 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4673 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
4675 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
4676 SCTP_STATE(SCTP_STATE_CLOSED
));
4678 SCTP_INC_STATS(SCTP_MIB_SHUTDOWNS
);
4680 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
4682 return SCTP_DISPOSITION_DELETE_TCB
;
4686 * sctp_cookie_echoed_prm_shutdown
4688 * Section: 4 Note: 2
4693 * The RFC does not explcitly address this issue, but is the route through the
4694 * state table when someone issues a shutdown while in COOKIE_ECHOED state.
4699 sctp_disposition_t
sctp_sf_cookie_echoed_prm_shutdown(
4700 const struct sctp_endpoint
*ep
,
4701 const struct sctp_association
*asoc
,
4702 const sctp_subtype_t type
,
4703 void *arg
, sctp_cmd_seq_t
*commands
)
4705 /* There is a single T1 timer, so we should be able to use
4706 * common function with the COOKIE-WAIT state.
4708 return sctp_sf_cookie_wait_prm_shutdown(ep
, asoc
, type
, arg
, commands
);
4712 * sctp_sf_cookie_wait_prm_abort
4714 * Section: 4 Note: 2
4719 * The RFC does not explicitly address this issue, but is the route through the
4720 * state table when someone issues an abort while in COOKIE_WAIT state.
4725 sctp_disposition_t
sctp_sf_cookie_wait_prm_abort(
4726 const struct sctp_endpoint
*ep
,
4727 const struct sctp_association
*asoc
,
4728 const sctp_subtype_t type
,
4730 sctp_cmd_seq_t
*commands
)
4732 struct sctp_chunk
*abort
= arg
;
4733 sctp_disposition_t retval
;
4735 /* Stop T1-init timer */
4736 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4737 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
4738 retval
= SCTP_DISPOSITION_CONSUME
;
4740 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(abort
));
4742 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
4743 SCTP_STATE(SCTP_STATE_CLOSED
));
4745 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
4747 /* Even if we can't send the ABORT due to low memory delete the
4748 * TCB. This is a departure from our typical NOMEM handling.
4751 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
4752 SCTP_ERROR(ECONNREFUSED
));
4753 /* Delete the established association. */
4754 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
4755 SCTP_PERR(SCTP_ERROR_USER_ABORT
));
4761 * sctp_sf_cookie_echoed_prm_abort
4763 * Section: 4 Note: 3
4768 * The RFC does not explcitly address this issue, but is the route through the
4769 * state table when someone issues an abort while in COOKIE_ECHOED state.
4774 sctp_disposition_t
sctp_sf_cookie_echoed_prm_abort(
4775 const struct sctp_endpoint
*ep
,
4776 const struct sctp_association
*asoc
,
4777 const sctp_subtype_t type
,
4779 sctp_cmd_seq_t
*commands
)
4781 /* There is a single T1 timer, so we should be able to use
4782 * common function with the COOKIE-WAIT state.
4784 return sctp_sf_cookie_wait_prm_abort(ep
, asoc
, type
, arg
, commands
);
4788 * sctp_sf_shutdown_pending_prm_abort
4793 * The RFC does not explicitly address this issue, but is the route through the
4794 * state table when someone issues an abort while in SHUTDOWN-PENDING state.
4799 sctp_disposition_t
sctp_sf_shutdown_pending_prm_abort(
4800 const struct sctp_endpoint
*ep
,
4801 const struct sctp_association
*asoc
,
4802 const sctp_subtype_t type
,
4804 sctp_cmd_seq_t
*commands
)
4806 /* Stop the T5-shutdown guard timer. */
4807 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4808 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
4810 return sctp_sf_do_9_1_prm_abort(ep
, asoc
, type
, arg
, commands
);
4814 * sctp_sf_shutdown_sent_prm_abort
4819 * The RFC does not explicitly address this issue, but is the route through the
4820 * state table when someone issues an abort while in SHUTDOWN-SENT state.
4825 sctp_disposition_t
sctp_sf_shutdown_sent_prm_abort(
4826 const struct sctp_endpoint
*ep
,
4827 const struct sctp_association
*asoc
,
4828 const sctp_subtype_t type
,
4830 sctp_cmd_seq_t
*commands
)
4832 /* Stop the T2-shutdown timer. */
4833 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4834 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
4836 /* Stop the T5-shutdown guard timer. */
4837 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4838 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
4840 return sctp_sf_do_9_1_prm_abort(ep
, asoc
, type
, arg
, commands
);
4844 * sctp_sf_cookie_echoed_prm_abort
4849 * The RFC does not explcitly address this issue, but is the route through the
4850 * state table when someone issues an abort while in COOKIE_ECHOED state.
4855 sctp_disposition_t
sctp_sf_shutdown_ack_sent_prm_abort(
4856 const struct sctp_endpoint
*ep
,
4857 const struct sctp_association
*asoc
,
4858 const sctp_subtype_t type
,
4860 sctp_cmd_seq_t
*commands
)
4862 /* The same T2 timer, so we should be able to use
4863 * common function with the SHUTDOWN-SENT state.
4865 return sctp_sf_shutdown_sent_prm_abort(ep
, asoc
, type
, arg
, commands
);
4869 * Process the REQUESTHEARTBEAT primitive
4872 * J) Request Heartbeat
4874 * Format: REQUESTHEARTBEAT(association id, destination transport address)
4878 * Instructs the local endpoint to perform a HeartBeat on the specified
4879 * destination transport address of the given association. The returned
4880 * result should indicate whether the transmission of the HEARTBEAT
4881 * chunk to the destination address is successful.
4883 * Mandatory attributes:
4885 * o association id - local handle to the SCTP association
4887 * o destination transport address - the transport address of the
4888 * association on which a heartbeat should be issued.
4890 sctp_disposition_t
sctp_sf_do_prm_requestheartbeat(
4891 const struct sctp_endpoint
*ep
,
4892 const struct sctp_association
*asoc
,
4893 const sctp_subtype_t type
,
4895 sctp_cmd_seq_t
*commands
)
4897 if (SCTP_DISPOSITION_NOMEM
== sctp_sf_heartbeat(ep
, asoc
, type
,
4898 (struct sctp_transport
*)arg
, commands
))
4899 return SCTP_DISPOSITION_NOMEM
;
4902 * RFC 2960 (bis), section 8.3
4904 * D) Request an on-demand HEARTBEAT on a specific destination
4905 * transport address of a given association.
4907 * The endpoint should increment the respective error counter of
4908 * the destination transport address each time a HEARTBEAT is sent
4909 * to that address and not acknowledged within one RTO.
4912 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSPORT_RESET
,
4913 SCTP_TRANSPORT(arg
));
4914 return SCTP_DISPOSITION_CONSUME
;
4918 * ADDIP Section 4.1 ASCONF Chunk Procedures
4919 * When an endpoint has an ASCONF signaled change to be sent to the
4920 * remote endpoint it should do A1 to A9
4922 sctp_disposition_t
sctp_sf_do_prm_asconf(const struct sctp_endpoint
*ep
,
4923 const struct sctp_association
*asoc
,
4924 const sctp_subtype_t type
,
4926 sctp_cmd_seq_t
*commands
)
4928 struct sctp_chunk
*chunk
= arg
;
4930 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T4
, SCTP_CHUNK(chunk
));
4931 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
4932 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
4933 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(chunk
));
4934 return SCTP_DISPOSITION_CONSUME
;
4938 * Ignore the primitive event
4940 * The return value is the disposition of the primitive.
4942 sctp_disposition_t
sctp_sf_ignore_primitive(
4943 const struct sctp_endpoint
*ep
,
4944 const struct sctp_association
*asoc
,
4945 const sctp_subtype_t type
,
4947 sctp_cmd_seq_t
*commands
)
4949 SCTP_DEBUG_PRINTK("Primitive type %d is ignored.\n", type
.primitive
);
4950 return SCTP_DISPOSITION_DISCARD
;
4953 /***************************************************************************
4954 * These are the state functions for the OTHER events.
4955 ***************************************************************************/
4958 * Start the shutdown negotiation.
4961 * Once all its outstanding data has been acknowledged, the endpoint
4962 * shall send a SHUTDOWN chunk to its peer including in the Cumulative
4963 * TSN Ack field the last sequential TSN it has received from the peer.
4964 * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT
4965 * state. If the timer expires, the endpoint must re-send the SHUTDOWN
4966 * with the updated last sequential TSN received from its peer.
4968 * The return value is the disposition.
4970 sctp_disposition_t
sctp_sf_do_9_2_start_shutdown(
4971 const struct sctp_endpoint
*ep
,
4972 const struct sctp_association
*asoc
,
4973 const sctp_subtype_t type
,
4975 sctp_cmd_seq_t
*commands
)
4977 struct sctp_chunk
*reply
;
4979 /* Once all its outstanding data has been acknowledged, the
4980 * endpoint shall send a SHUTDOWN chunk to its peer including
4981 * in the Cumulative TSN Ack field the last sequential TSN it
4982 * has received from the peer.
4984 reply
= sctp_make_shutdown(asoc
, NULL
);
4988 /* Set the transport for the SHUTDOWN chunk and the timeout for the
4989 * T2-shutdown timer.
4991 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T2
, SCTP_CHUNK(reply
));
4993 /* It shall then start the T2-shutdown timer */
4994 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
4995 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
4997 if (asoc
->autoclose
)
4998 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4999 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
5001 /* and enter the SHUTDOWN-SENT state. */
5002 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
5003 SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT
));
5005 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5007 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
5010 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_STOP
, SCTP_NULL());
5012 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
5014 return SCTP_DISPOSITION_CONSUME
;
5017 return SCTP_DISPOSITION_NOMEM
;
5021 * Generate a SHUTDOWN ACK now that everything is SACK'd.
5025 * If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5026 * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own,
5027 * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the
5028 * endpoint must re-send the SHUTDOWN ACK.
5030 * The return value is the disposition.
5032 sctp_disposition_t
sctp_sf_do_9_2_shutdown_ack(
5033 const struct sctp_endpoint
*ep
,
5034 const struct sctp_association
*asoc
,
5035 const sctp_subtype_t type
,
5037 sctp_cmd_seq_t
*commands
)
5039 struct sctp_chunk
*chunk
= (struct sctp_chunk
*) arg
;
5040 struct sctp_chunk
*reply
;
5042 /* There are 2 ways of getting here:
5043 * 1) called in response to a SHUTDOWN chunk
5044 * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued.
5046 * For the case (2), the arg parameter is set to NULL. We need
5047 * to check that we have a chunk before accessing it's fields.
5050 if (!sctp_vtag_verify(chunk
, asoc
))
5051 return sctp_sf_pdiscard(ep
, asoc
, type
, arg
, commands
);
5053 /* Make sure that the SHUTDOWN chunk has a valid length. */
5054 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_shutdown_chunk_t
)))
5055 return sctp_sf_violation_chunklen(ep
, asoc
, type
, arg
,
5059 /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5060 * shall send a SHUTDOWN ACK ...
5062 reply
= sctp_make_shutdown_ack(asoc
, chunk
);
5066 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
5067 * the T2-shutdown timer.
5069 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T2
, SCTP_CHUNK(reply
));
5071 /* and start/restart a T2-shutdown timer of its own, */
5072 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
5073 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
5075 if (asoc
->autoclose
)
5076 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
5077 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
5079 /* Enter the SHUTDOWN-ACK-SENT state. */
5080 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
5081 SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT
));
5083 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5085 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
5088 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_STOP
, SCTP_NULL());
5090 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
5092 return SCTP_DISPOSITION_CONSUME
;
5095 return SCTP_DISPOSITION_NOMEM
;
5099 * Ignore the event defined as other
5101 * The return value is the disposition of the event.
5103 sctp_disposition_t
sctp_sf_ignore_other(const struct sctp_endpoint
*ep
,
5104 const struct sctp_association
*asoc
,
5105 const sctp_subtype_t type
,
5107 sctp_cmd_seq_t
*commands
)
5109 SCTP_DEBUG_PRINTK("The event other type %d is ignored\n", type
.other
);
5110 return SCTP_DISPOSITION_DISCARD
;
5113 /************************************************************
5114 * These are the state functions for handling timeout events.
5115 ************************************************************/
5120 * Section: 6.3.3 Handle T3-rtx Expiration
5122 * Whenever the retransmission timer T3-rtx expires for a destination
5123 * address, do the following:
5126 * The return value is the disposition of the chunk.
5128 sctp_disposition_t
sctp_sf_do_6_3_3_rtx(const struct sctp_endpoint
*ep
,
5129 const struct sctp_association
*asoc
,
5130 const sctp_subtype_t type
,
5132 sctp_cmd_seq_t
*commands
)
5134 struct sctp_transport
*transport
= arg
;
5136 SCTP_INC_STATS(SCTP_MIB_T3_RTX_EXPIREDS
);
5138 if (asoc
->overall_error_count
>= asoc
->max_retrans
) {
5139 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5140 SCTP_ERROR(ETIMEDOUT
));
5141 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5142 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
5143 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5144 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
5145 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
5146 return SCTP_DISPOSITION_DELETE_TCB
;
5149 /* E1) For the destination address for which the timer
5150 * expires, adjust its ssthresh with rules defined in Section
5151 * 7.2.3 and set the cwnd <- MTU.
5154 /* E2) For the destination address for which the timer
5155 * expires, set RTO <- RTO * 2 ("back off the timer"). The
5156 * maximum value discussed in rule C7 above (RTO.max) may be
5157 * used to provide an upper bound to this doubling operation.
5160 /* E3) Determine how many of the earliest (i.e., lowest TSN)
5161 * outstanding DATA chunks for the address for which the
5162 * T3-rtx has expired will fit into a single packet, subject
5163 * to the MTU constraint for the path corresponding to the
5164 * destination transport address to which the retransmission
5165 * is being sent (this may be different from the address for
5166 * which the timer expires [see Section 6.4]). Call this
5167 * value K. Bundle and retransmit those K DATA chunks in a
5168 * single packet to the destination endpoint.
5170 * Note: Any DATA chunks that were sent to the address for
5171 * which the T3-rtx timer expired but did not fit in one MTU
5172 * (rule E3 above), should be marked for retransmission and
5173 * sent as soon as cwnd allows (normally when a SACK arrives).
5176 /* Do some failure management (Section 8.2). */
5177 sctp_add_cmd_sf(commands
, SCTP_CMD_STRIKE
, SCTP_TRANSPORT(transport
));
5179 /* NB: Rules E4 and F1 are implicit in R1. */
5180 sctp_add_cmd_sf(commands
, SCTP_CMD_RETRAN
, SCTP_TRANSPORT(transport
));
5182 return SCTP_DISPOSITION_CONSUME
;
5186 * Generate delayed SACK on timeout
5188 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
5190 * The guidelines on delayed acknowledgement algorithm specified in
5191 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
5192 * acknowledgement SHOULD be generated for at least every second packet
5193 * (not every second DATA chunk) received, and SHOULD be generated
5194 * within 200 ms of the arrival of any unacknowledged DATA chunk. In
5195 * some situations it may be beneficial for an SCTP transmitter to be
5196 * more conservative than the algorithms detailed in this document
5197 * allow. However, an SCTP transmitter MUST NOT be more aggressive than
5198 * the following algorithms allow.
5200 sctp_disposition_t
sctp_sf_do_6_2_sack(const struct sctp_endpoint
*ep
,
5201 const struct sctp_association
*asoc
,
5202 const sctp_subtype_t type
,
5204 sctp_cmd_seq_t
*commands
)
5206 SCTP_INC_STATS(SCTP_MIB_DELAY_SACK_EXPIREDS
);
5207 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_FORCE());
5208 return SCTP_DISPOSITION_CONSUME
;
5212 * sctp_sf_t1_init_timer_expire
5214 * Section: 4 Note: 2
5219 * RFC 2960 Section 4 Notes
5220 * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT
5221 * and re-start the T1-init timer without changing state. This MUST
5222 * be repeated up to 'Max.Init.Retransmits' times. After that, the
5223 * endpoint MUST abort the initialization process and report the
5224 * error to SCTP user.
5230 sctp_disposition_t
sctp_sf_t1_init_timer_expire(const struct sctp_endpoint
*ep
,
5231 const struct sctp_association
*asoc
,
5232 const sctp_subtype_t type
,
5234 sctp_cmd_seq_t
*commands
)
5236 struct sctp_chunk
*repl
= NULL
;
5237 struct sctp_bind_addr
*bp
;
5238 int attempts
= asoc
->init_err_counter
+ 1;
5240 SCTP_DEBUG_PRINTK("Timer T1 expired (INIT).\n");
5241 SCTP_INC_STATS(SCTP_MIB_T1_INIT_EXPIREDS
);
5243 if (attempts
<= asoc
->max_init_attempts
) {
5244 bp
= (struct sctp_bind_addr
*) &asoc
->base
.bind_addr
;
5245 repl
= sctp_make_init(asoc
, bp
, GFP_ATOMIC
, 0);
5247 return SCTP_DISPOSITION_NOMEM
;
5249 /* Choose transport for INIT. */
5250 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_CHOOSE_TRANSPORT
,
5253 /* Issue a sideeffect to do the needed accounting. */
5254 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_RESTART
,
5255 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
5257 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
5259 SCTP_DEBUG_PRINTK("Giving up on INIT, attempts: %d"
5260 " max_init_attempts: %d\n",
5261 attempts
, asoc
->max_init_attempts
);
5262 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5263 SCTP_ERROR(ETIMEDOUT
));
5264 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
5265 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5266 return SCTP_DISPOSITION_DELETE_TCB
;
5269 return SCTP_DISPOSITION_CONSUME
;
5273 * sctp_sf_t1_cookie_timer_expire
5275 * Section: 4 Note: 2
5280 * RFC 2960 Section 4 Notes
5281 * 3) If the T1-cookie timer expires, the endpoint MUST retransmit
5282 * COOKIE ECHO and re-start the T1-cookie timer without changing
5283 * state. This MUST be repeated up to 'Max.Init.Retransmits' times.
5284 * After that, the endpoint MUST abort the initialization process and
5285 * report the error to SCTP user.
5291 sctp_disposition_t
sctp_sf_t1_cookie_timer_expire(const struct sctp_endpoint
*ep
,
5292 const struct sctp_association
*asoc
,
5293 const sctp_subtype_t type
,
5295 sctp_cmd_seq_t
*commands
)
5297 struct sctp_chunk
*repl
= NULL
;
5298 int attempts
= asoc
->init_err_counter
+ 1;
5300 SCTP_DEBUG_PRINTK("Timer T1 expired (COOKIE-ECHO).\n");
5301 SCTP_INC_STATS(SCTP_MIB_T1_COOKIE_EXPIREDS
);
5303 if (attempts
<= asoc
->max_init_attempts
) {
5304 repl
= sctp_make_cookie_echo(asoc
, NULL
);
5306 return SCTP_DISPOSITION_NOMEM
;
5308 /* Issue a sideeffect to do the needed accounting. */
5309 sctp_add_cmd_sf(commands
, SCTP_CMD_COOKIEECHO_RESTART
,
5310 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
5312 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
5314 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5315 SCTP_ERROR(ETIMEDOUT
));
5316 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
5317 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5318 return SCTP_DISPOSITION_DELETE_TCB
;
5321 return SCTP_DISPOSITION_CONSUME
;
5324 /* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN
5325 * with the updated last sequential TSN received from its peer.
5327 * An endpoint should limit the number of retransmissions of the
5328 * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'.
5329 * If this threshold is exceeded the endpoint should destroy the TCB and
5330 * MUST report the peer endpoint unreachable to the upper layer (and
5331 * thus the association enters the CLOSED state). The reception of any
5332 * packet from its peer (i.e. as the peer sends all of its queued DATA
5333 * chunks) should clear the endpoint's retransmission count and restart
5334 * the T2-Shutdown timer, giving its peer ample opportunity to transmit
5335 * all of its queued DATA chunks that have not yet been sent.
5337 sctp_disposition_t
sctp_sf_t2_timer_expire(const struct sctp_endpoint
*ep
,
5338 const struct sctp_association
*asoc
,
5339 const sctp_subtype_t type
,
5341 sctp_cmd_seq_t
*commands
)
5343 struct sctp_chunk
*reply
= NULL
;
5345 SCTP_DEBUG_PRINTK("Timer T2 expired.\n");
5346 SCTP_INC_STATS(SCTP_MIB_T2_SHUTDOWN_EXPIREDS
);
5348 ((struct sctp_association
*)asoc
)->shutdown_retries
++;
5350 if (asoc
->overall_error_count
>= asoc
->max_retrans
) {
5351 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5352 SCTP_ERROR(ETIMEDOUT
));
5353 /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5354 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
5355 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5356 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
5357 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
5358 return SCTP_DISPOSITION_DELETE_TCB
;
5361 switch (asoc
->state
) {
5362 case SCTP_STATE_SHUTDOWN_SENT
:
5363 reply
= sctp_make_shutdown(asoc
, NULL
);
5366 case SCTP_STATE_SHUTDOWN_ACK_SENT
:
5367 reply
= sctp_make_shutdown_ack(asoc
, NULL
);
5378 /* Do some failure management (Section 8.2). */
5379 sctp_add_cmd_sf(commands
, SCTP_CMD_STRIKE
,
5380 SCTP_TRANSPORT(asoc
->shutdown_last_sent_to
));
5382 /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for
5383 * the T2-shutdown timer.
5385 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T2
, SCTP_CHUNK(reply
));
5387 /* Restart the T2-shutdown timer. */
5388 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
5389 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
5390 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
5391 return SCTP_DISPOSITION_CONSUME
;
5394 return SCTP_DISPOSITION_NOMEM
;
5398 * ADDIP Section 4.1 ASCONF CHunk Procedures
5399 * If the T4 RTO timer expires the endpoint should do B1 to B5
5401 sctp_disposition_t
sctp_sf_t4_timer_expire(
5402 const struct sctp_endpoint
*ep
,
5403 const struct sctp_association
*asoc
,
5404 const sctp_subtype_t type
,
5406 sctp_cmd_seq_t
*commands
)
5408 struct sctp_chunk
*chunk
= asoc
->addip_last_asconf
;
5409 struct sctp_transport
*transport
= chunk
->transport
;
5411 SCTP_INC_STATS(SCTP_MIB_T4_RTO_EXPIREDS
);
5413 /* ADDIP 4.1 B1) Increment the error counters and perform path failure
5414 * detection on the appropriate destination address as defined in
5415 * RFC2960 [5] section 8.1 and 8.2.
5417 sctp_add_cmd_sf(commands
, SCTP_CMD_STRIKE
, SCTP_TRANSPORT(transport
));
5419 /* Reconfig T4 timer and transport. */
5420 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T4
, SCTP_CHUNK(chunk
));
5422 /* ADDIP 4.1 B2) Increment the association error counters and perform
5423 * endpoint failure detection on the association as defined in
5424 * RFC2960 [5] section 8.1 and 8.2.
5425 * association error counter is incremented in SCTP_CMD_STRIKE.
5427 if (asoc
->overall_error_count
>= asoc
->max_retrans
) {
5428 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
5429 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
5430 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5431 SCTP_ERROR(ETIMEDOUT
));
5432 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
5433 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5434 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
5435 SCTP_INC_STATS(SCTP_MIB_CURRESTAB
);
5436 return SCTP_DISPOSITION_ABORT
;
5439 /* ADDIP 4.1 B3) Back-off the destination address RTO value to which
5440 * the ASCONF chunk was sent by doubling the RTO timer value.
5441 * This is done in SCTP_CMD_STRIKE.
5444 /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible
5445 * choose an alternate destination address (please refer to RFC2960
5446 * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this
5447 * chunk, it MUST be the same (including its serial number) as the last
5450 sctp_chunk_hold(asoc
->addip_last_asconf
);
5451 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
5452 SCTP_CHUNK(asoc
->addip_last_asconf
));
5454 /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different
5455 * destination is selected, then the RTO used will be that of the new
5456 * destination address.
5458 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
5459 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
5461 return SCTP_DISPOSITION_CONSUME
;
5464 /* sctpimpguide-05 Section 2.12.2
5465 * The sender of the SHUTDOWN MAY also start an overall guard timer
5466 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5467 * At the expiration of this timer the sender SHOULD abort the association
5468 * by sending an ABORT chunk.
5470 sctp_disposition_t
sctp_sf_t5_timer_expire(const struct sctp_endpoint
*ep
,
5471 const struct sctp_association
*asoc
,
5472 const sctp_subtype_t type
,
5474 sctp_cmd_seq_t
*commands
)
5476 struct sctp_chunk
*reply
= NULL
;
5478 SCTP_DEBUG_PRINTK("Timer T5 expired.\n");
5479 SCTP_INC_STATS(SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS
);
5481 reply
= sctp_make_abort(asoc
, NULL
, 0);
5485 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
5486 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5487 SCTP_ERROR(ETIMEDOUT
));
5488 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
5489 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5491 return SCTP_DISPOSITION_DELETE_TCB
;
5493 return SCTP_DISPOSITION_NOMEM
;
5496 /* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires,
5497 * the association is automatically closed by starting the shutdown process.
5498 * The work that needs to be done is same as when SHUTDOWN is initiated by
5499 * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown().
5501 sctp_disposition_t
sctp_sf_autoclose_timer_expire(
5502 const struct sctp_endpoint
*ep
,
5503 const struct sctp_association
*asoc
,
5504 const sctp_subtype_t type
,
5506 sctp_cmd_seq_t
*commands
)
5510 SCTP_INC_STATS(SCTP_MIB_AUTOCLOSE_EXPIREDS
);
5512 /* From 9.2 Shutdown of an Association
5513 * Upon receipt of the SHUTDOWN primitive from its upper
5514 * layer, the endpoint enters SHUTDOWN-PENDING state and
5515 * remains there until all outstanding data has been
5516 * acknowledged by its peer. The endpoint accepts no new data
5517 * from its upper layer, but retransmits data to the far end
5518 * if necessary to fill gaps.
5520 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
5521 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING
));
5523 /* sctpimpguide-05 Section 2.12.2
5524 * The sender of the SHUTDOWN MAY also start an overall guard timer
5525 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5527 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
5528 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
5529 disposition
= SCTP_DISPOSITION_CONSUME
;
5530 if (sctp_outq_is_empty(&asoc
->outqueue
)) {
5531 disposition
= sctp_sf_do_9_2_start_shutdown(ep
, asoc
, type
,
5537 /*****************************************************************************
5538 * These are sa state functions which could apply to all types of events.
5539 ****************************************************************************/
5542 * This table entry is not implemented.
5545 * (endpoint, asoc, chunk)
5547 * The return value is the disposition of the chunk.
5549 sctp_disposition_t
sctp_sf_not_impl(const struct sctp_endpoint
*ep
,
5550 const struct sctp_association
*asoc
,
5551 const sctp_subtype_t type
,
5553 sctp_cmd_seq_t
*commands
)
5555 return SCTP_DISPOSITION_NOT_IMPL
;
5559 * This table entry represents a bug.
5562 * (endpoint, asoc, chunk)
5564 * The return value is the disposition of the chunk.
5566 sctp_disposition_t
sctp_sf_bug(const struct sctp_endpoint
*ep
,
5567 const struct sctp_association
*asoc
,
5568 const sctp_subtype_t type
,
5570 sctp_cmd_seq_t
*commands
)
5572 return SCTP_DISPOSITION_BUG
;
5576 * This table entry represents the firing of a timer in the wrong state.
5577 * Since timer deletion cannot be guaranteed a timer 'may' end up firing
5578 * when the association is in the wrong state. This event should
5579 * be ignored, so as to prevent any rearming of the timer.
5582 * (endpoint, asoc, chunk)
5584 * The return value is the disposition of the chunk.
5586 sctp_disposition_t
sctp_sf_timer_ignore(const struct sctp_endpoint
*ep
,
5587 const struct sctp_association
*asoc
,
5588 const sctp_subtype_t type
,
5590 sctp_cmd_seq_t
*commands
)
5592 SCTP_DEBUG_PRINTK("Timer %d ignored.\n", type
.chunk
);
5593 return SCTP_DISPOSITION_CONSUME
;
5596 /********************************************************************
5597 * 2nd Level Abstractions
5598 ********************************************************************/
5600 /* Pull the SACK chunk based on the SACK header. */
5601 static struct sctp_sackhdr
*sctp_sm_pull_sack(struct sctp_chunk
*chunk
)
5603 struct sctp_sackhdr
*sack
;
5608 /* Protect ourselves from reading too far into
5609 * the skb from a bogus sender.
5611 sack
= (struct sctp_sackhdr
*) chunk
->skb
->data
;
5613 num_blocks
= ntohs(sack
->num_gap_ack_blocks
);
5614 num_dup_tsns
= ntohs(sack
->num_dup_tsns
);
5615 len
= sizeof(struct sctp_sackhdr
);
5616 len
+= (num_blocks
+ num_dup_tsns
) * sizeof(__u32
);
5617 if (len
> chunk
->skb
->len
)
5620 skb_pull(chunk
->skb
, len
);
5625 /* Create an ABORT packet to be sent as a response, with the specified
5628 static struct sctp_packet
*sctp_abort_pkt_new(const struct sctp_endpoint
*ep
,
5629 const struct sctp_association
*asoc
,
5630 struct sctp_chunk
*chunk
,
5631 const void *payload
,
5634 struct sctp_packet
*packet
;
5635 struct sctp_chunk
*abort
;
5637 packet
= sctp_ootb_pkt_new(asoc
, chunk
);
5641 * The T bit will be set if the asoc is NULL.
5643 abort
= sctp_make_abort(asoc
, chunk
, paylen
);
5645 sctp_ootb_pkt_free(packet
);
5649 /* Reflect vtag if T-Bit is set */
5650 if (sctp_test_T_bit(abort
))
5651 packet
->vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
5653 /* Add specified error causes, i.e., payload, to the
5656 sctp_addto_chunk(abort
, paylen
, payload
);
5658 /* Set the skb to the belonging sock for accounting. */
5659 abort
->skb
->sk
= ep
->base
.sk
;
5661 sctp_packet_append_chunk(packet
, abort
);
5668 /* Allocate a packet for responding in the OOTB conditions. */
5669 static struct sctp_packet
*sctp_ootb_pkt_new(const struct sctp_association
*asoc
,
5670 const struct sctp_chunk
*chunk
)
5672 struct sctp_packet
*packet
;
5673 struct sctp_transport
*transport
;
5678 /* Get the source and destination port from the inbound packet. */
5679 sport
= ntohs(chunk
->sctp_hdr
->dest
);
5680 dport
= ntohs(chunk
->sctp_hdr
->source
);
5682 /* The V-tag is going to be the same as the inbound packet if no
5683 * association exists, otherwise, use the peer's vtag.
5686 /* Special case the INIT-ACK as there is no peer's vtag
5689 switch(chunk
->chunk_hdr
->type
) {
5690 case SCTP_CID_INIT_ACK
:
5692 sctp_initack_chunk_t
*initack
;
5694 initack
= (sctp_initack_chunk_t
*)chunk
->chunk_hdr
;
5695 vtag
= ntohl(initack
->init_hdr
.init_tag
);
5699 vtag
= asoc
->peer
.i
.init_tag
;
5703 /* Special case the INIT and stale COOKIE_ECHO as there is no
5706 switch(chunk
->chunk_hdr
->type
) {
5709 sctp_init_chunk_t
*init
;
5711 init
= (sctp_init_chunk_t
*)chunk
->chunk_hdr
;
5712 vtag
= ntohl(init
->init_hdr
.init_tag
);
5716 vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
5721 /* Make a transport for the bucket, Eliza... */
5722 transport
= sctp_transport_new(sctp_source(chunk
), GFP_ATOMIC
);
5726 /* Cache a route for the transport with the chunk's destination as
5727 * the source address.
5729 sctp_transport_route(transport
, (union sctp_addr
*)&chunk
->dest
,
5730 sctp_sk(sctp_get_ctl_sock()));
5732 packet
= sctp_packet_init(&transport
->packet
, transport
, sport
, dport
);
5733 packet
= sctp_packet_config(packet
, vtag
, 0);
5741 /* Free the packet allocated earlier for responding in the OOTB condition. */
5742 void sctp_ootb_pkt_free(struct sctp_packet
*packet
)
5744 sctp_transport_free(packet
->transport
);
5747 /* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */
5748 static void sctp_send_stale_cookie_err(const struct sctp_endpoint
*ep
,
5749 const struct sctp_association
*asoc
,
5750 const struct sctp_chunk
*chunk
,
5751 sctp_cmd_seq_t
*commands
,
5752 struct sctp_chunk
*err_chunk
)
5754 struct sctp_packet
*packet
;
5757 packet
= sctp_ootb_pkt_new(asoc
, chunk
);
5759 struct sctp_signed_cookie
*cookie
;
5761 /* Override the OOTB vtag from the cookie. */
5762 cookie
= chunk
->subh
.cookie_hdr
;
5763 packet
->vtag
= cookie
->c
.peer_vtag
;
5765 /* Set the skb to the belonging sock for accounting. */
5766 err_chunk
->skb
->sk
= ep
->base
.sk
;
5767 sctp_packet_append_chunk(packet
, err_chunk
);
5768 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
5769 SCTP_PACKET(packet
));
5770 SCTP_INC_STATS(SCTP_MIB_OUTCTRLCHUNKS
);
5772 sctp_chunk_free (err_chunk
);
5777 /* Process a data chunk */
5778 static int sctp_eat_data(const struct sctp_association
*asoc
,
5779 struct sctp_chunk
*chunk
,
5780 sctp_cmd_seq_t
*commands
)
5782 sctp_datahdr_t
*data_hdr
;
5783 struct sctp_chunk
*err
;
5785 sctp_verb_t deliver
;
5788 struct sctp_tsnmap
*map
= (struct sctp_tsnmap
*)&asoc
->peer
.tsn_map
;
5789 struct sock
*sk
= asoc
->base
.sk
;
5791 data_hdr
= chunk
->subh
.data_hdr
= (sctp_datahdr_t
*)chunk
->skb
->data
;
5792 skb_pull(chunk
->skb
, sizeof(sctp_datahdr_t
));
5794 tsn
= ntohl(data_hdr
->tsn
);
5795 SCTP_DEBUG_PRINTK("eat_data: TSN 0x%x.\n", tsn
);
5797 /* ASSERT: Now skb->data is really the user data. */
5799 /* Process ECN based congestion.
5801 * Since the chunk structure is reused for all chunks within
5802 * a packet, we use ecn_ce_done to track if we've already
5803 * done CE processing for this packet.
5805 * We need to do ECN processing even if we plan to discard the
5809 if (!chunk
->ecn_ce_done
) {
5811 chunk
->ecn_ce_done
= 1;
5813 af
= sctp_get_af_specific(
5814 ipver2af(ip_hdr(chunk
->skb
)->version
));
5816 if (af
&& af
->is_ce(chunk
->skb
) && asoc
->peer
.ecn_capable
) {
5817 /* Do real work as sideffect. */
5818 sctp_add_cmd_sf(commands
, SCTP_CMD_ECN_CE
,
5823 tmp
= sctp_tsnmap_check(&asoc
->peer
.tsn_map
, tsn
);
5825 /* The TSN is too high--silently discard the chunk and
5826 * count on it getting retransmitted later.
5828 return SCTP_IERROR_HIGH_TSN
;
5829 } else if (tmp
> 0) {
5830 /* This is a duplicate. Record it. */
5831 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_DUP
, SCTP_U32(tsn
));
5832 return SCTP_IERROR_DUP_TSN
;
5835 /* This is a new TSN. */
5837 /* Discard if there is no room in the receive window.
5838 * Actually, allow a little bit of overflow (up to a MTU).
5840 datalen
= ntohs(chunk
->chunk_hdr
->length
);
5841 datalen
-= sizeof(sctp_data_chunk_t
);
5843 deliver
= SCTP_CMD_CHUNK_ULP
;
5845 /* Think about partial delivery. */
5846 if ((datalen
>= asoc
->rwnd
) && (!asoc
->ulpq
.pd_mode
)) {
5848 /* Even if we don't accept this chunk there is
5851 sctp_add_cmd_sf(commands
, SCTP_CMD_PART_DELIVER
, SCTP_NULL());
5854 /* Spill over rwnd a little bit. Note: While allowed, this spill over
5855 * seems a bit troublesome in that frag_point varies based on
5856 * PMTU. In cases, such as loopback, this might be a rather
5859 if ((!chunk
->data_accepted
) && (!asoc
->rwnd
|| asoc
->rwnd_over
||
5860 (datalen
> asoc
->rwnd
+ asoc
->frag_point
))) {
5862 /* If this is the next TSN, consider reneging to make
5863 * room. Note: Playing nice with a confused sender. A
5864 * malicious sender can still eat up all our buffer
5865 * space and in the future we may want to detect and
5866 * do more drastic reneging.
5868 if (sctp_tsnmap_has_gap(map
) &&
5869 (sctp_tsnmap_get_ctsn(map
) + 1) == tsn
) {
5870 SCTP_DEBUG_PRINTK("Reneging for tsn:%u\n", tsn
);
5871 deliver
= SCTP_CMD_RENEGE
;
5873 SCTP_DEBUG_PRINTK("Discard tsn: %u len: %Zd, "
5874 "rwnd: %d\n", tsn
, datalen
,
5876 return SCTP_IERROR_IGNORE_TSN
;
5881 * Also try to renege to limit our memory usage in the event that
5882 * we are under memory pressure
5883 * If we can't renege, don't worry about it, the sk_rmem_schedule
5884 * in sctp_ulpevent_make_rcvmsg will drop the frame if we grow our
5885 * memory usage too much
5887 if (*sk
->sk_prot_creator
->memory_pressure
) {
5888 if (sctp_tsnmap_has_gap(map
) &&
5889 (sctp_tsnmap_get_ctsn(map
) + 1) == tsn
) {
5890 SCTP_DEBUG_PRINTK("Under Pressure! Reneging for tsn:%u\n", tsn
);
5891 deliver
= SCTP_CMD_RENEGE
;
5896 * Section 3.3.10.9 No User Data (9)
5900 * No User Data: This error cause is returned to the originator of a
5901 * DATA chunk if a received DATA chunk has no user data.
5903 if (unlikely(0 == datalen
)) {
5904 err
= sctp_make_abort_no_data(asoc
, chunk
, tsn
);
5906 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
5909 /* We are going to ABORT, so we might as well stop
5910 * processing the rest of the chunks in the packet.
5912 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
,SCTP_NULL());
5913 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5914 SCTP_ERROR(ECONNABORTED
));
5915 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
5916 SCTP_PERR(SCTP_ERROR_NO_DATA
));
5917 SCTP_INC_STATS(SCTP_MIB_ABORTEDS
);
5918 SCTP_DEC_STATS(SCTP_MIB_CURRESTAB
);
5919 return SCTP_IERROR_NO_DATA
;
5922 chunk
->data_accepted
= 1;
5924 /* Note: Some chunks may get overcounted (if we drop) or overcounted
5925 * if we renege and the chunk arrives again.
5927 if (chunk
->chunk_hdr
->flags
& SCTP_DATA_UNORDERED
)
5928 SCTP_INC_STATS(SCTP_MIB_INUNORDERCHUNKS
);
5930 SCTP_INC_STATS(SCTP_MIB_INORDERCHUNKS
);
5932 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
5934 * If an endpoint receive a DATA chunk with an invalid stream
5935 * identifier, it shall acknowledge the reception of the DATA chunk
5936 * following the normal procedure, immediately send an ERROR chunk
5937 * with cause set to "Invalid Stream Identifier" (See Section 3.3.10)
5938 * and discard the DATA chunk.
5940 if (ntohs(data_hdr
->stream
) >= asoc
->c
.sinit_max_instreams
) {
5941 /* Mark tsn as received even though we drop it */
5942 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_TSN
, SCTP_U32(tsn
));
5944 err
= sctp_make_op_error(asoc
, chunk
, SCTP_ERROR_INV_STRM
,
5946 sizeof(data_hdr
->stream
));
5948 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
5950 return SCTP_IERROR_BAD_STREAM
;
5953 /* Send the data up to the user. Note: Schedule the
5954 * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK
5955 * chunk needs the updated rwnd.
5957 sctp_add_cmd_sf(commands
, deliver
, SCTP_CHUNK(chunk
));
5959 return SCTP_IERROR_NO_ERROR
;