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, see
26 * <http://www.gnu.org/licenses/>.
28 * Please send any bug reports or fixes you make to the
30 * lksctp developers <linux-sctp@vger.kernel.org>
32 * Written or modified by:
33 * La Monte H.P. Yarroll <piggy@acm.org>
34 * Karl Knutson <karl@athena.chicago.il.us>
35 * Mathew Kotowsky <kotowsky@sctp.org>
36 * Sridhar Samudrala <samudrala@us.ibm.com>
37 * Jon Grimm <jgrimm@us.ibm.com>
38 * Hui Huang <hui.huang@nokia.com>
39 * Dajiang Zhang <dajiang.zhang@nokia.com>
40 * Daisy Chang <daisyc@us.ibm.com>
41 * Ardelle Fan <ardelle.fan@intel.com>
42 * Ryan Layer <rmlayer@us.ibm.com>
43 * Kevin Gao <kevin.gao@intel.com>
46 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
48 #include <linux/types.h>
49 #include <linux/kernel.h>
51 #include <linux/ipv6.h>
52 #include <linux/net.h>
53 #include <linux/inet.h>
54 #include <linux/slab.h>
56 #include <net/inet_ecn.h>
57 #include <linux/skbuff.h>
58 #include <net/sctp/sctp.h>
59 #include <net/sctp/sm.h>
60 #include <net/sctp/structs.h>
62 static struct sctp_packet
*sctp_abort_pkt_new(struct net
*net
,
63 const struct sctp_endpoint
*ep
,
64 const struct sctp_association
*asoc
,
65 struct sctp_chunk
*chunk
,
68 static int sctp_eat_data(const struct sctp_association
*asoc
,
69 struct sctp_chunk
*chunk
,
70 sctp_cmd_seq_t
*commands
);
71 static struct sctp_packet
*sctp_ootb_pkt_new(struct net
*net
,
72 const struct sctp_association
*asoc
,
73 const struct sctp_chunk
*chunk
);
74 static void sctp_send_stale_cookie_err(struct net
*net
,
75 const struct sctp_endpoint
*ep
,
76 const struct sctp_association
*asoc
,
77 const struct sctp_chunk
*chunk
,
78 sctp_cmd_seq_t
*commands
,
79 struct sctp_chunk
*err_chunk
);
80 static sctp_disposition_t
sctp_sf_do_5_2_6_stale(struct net
*net
,
81 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(struct net
*net
,
87 const struct sctp_endpoint
*ep
,
88 const struct sctp_association
*asoc
,
89 const sctp_subtype_t type
,
91 sctp_cmd_seq_t
*commands
);
92 static sctp_disposition_t
sctp_sf_tabort_8_4_8(struct net
*net
,
93 const struct sctp_endpoint
*ep
,
94 const struct sctp_association
*asoc
,
95 const sctp_subtype_t type
,
97 sctp_cmd_seq_t
*commands
);
98 static struct sctp_sackhdr
*sctp_sm_pull_sack(struct sctp_chunk
*chunk
);
100 static sctp_disposition_t
sctp_stop_t1_and_abort(struct net
*net
,
101 sctp_cmd_seq_t
*commands
,
102 __be16 error
, int sk_err
,
103 const struct sctp_association
*asoc
,
104 struct sctp_transport
*transport
);
106 static sctp_disposition_t
sctp_sf_abort_violation(
108 const struct sctp_endpoint
*ep
,
109 const struct sctp_association
*asoc
,
111 sctp_cmd_seq_t
*commands
,
113 const size_t paylen
);
115 static sctp_disposition_t
sctp_sf_violation_chunklen(
117 const struct sctp_endpoint
*ep
,
118 const struct sctp_association
*asoc
,
119 const sctp_subtype_t type
,
121 sctp_cmd_seq_t
*commands
);
123 static sctp_disposition_t
sctp_sf_violation_paramlen(
125 const struct sctp_endpoint
*ep
,
126 const struct sctp_association
*asoc
,
127 const sctp_subtype_t type
,
128 void *arg
, void *ext
,
129 sctp_cmd_seq_t
*commands
);
131 static sctp_disposition_t
sctp_sf_violation_ctsn(
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_disposition_t
sctp_sf_violation_chunk(
141 const struct sctp_endpoint
*ep
,
142 const struct sctp_association
*asoc
,
143 const sctp_subtype_t type
,
145 sctp_cmd_seq_t
*commands
);
147 static sctp_ierror_t
sctp_sf_authenticate(struct net
*net
,
148 const struct sctp_endpoint
*ep
,
149 const struct sctp_association
*asoc
,
150 const sctp_subtype_t type
,
151 struct sctp_chunk
*chunk
);
153 static sctp_disposition_t
__sctp_sf_do_9_1_abort(struct net
*net
,
154 const struct sctp_endpoint
*ep
,
155 const struct sctp_association
*asoc
,
156 const sctp_subtype_t type
,
158 sctp_cmd_seq_t
*commands
);
160 /* Small helper function that checks if the chunk length
161 * is of the appropriate length. The 'required_length' argument
162 * is set to be the size of a specific chunk we are testing.
163 * Return Values: true = Valid length
164 * false = Invalid length
168 sctp_chunk_length_valid(struct sctp_chunk
*chunk
, __u16 required_length
)
170 __u16 chunk_length
= ntohs(chunk
->chunk_hdr
->length
);
172 /* Previously already marked? */
173 if (unlikely(chunk
->pdiscard
))
175 if (unlikely(chunk_length
< required_length
))
181 /**********************************************************
182 * These are the state functions for handling chunk events.
183 **********************************************************/
186 * Process the final SHUTDOWN COMPLETE.
188 * Section: 4 (C) (diagram), 9.2
189 * Upon reception of the SHUTDOWN COMPLETE chunk the endpoint will verify
190 * that it is in SHUTDOWN-ACK-SENT state, if it is not the chunk should be
191 * discarded. If the endpoint is in the SHUTDOWN-ACK-SENT state the endpoint
192 * should stop the T2-shutdown timer and remove all knowledge of the
193 * association (and thus the association enters the CLOSED state).
195 * Verification Tag: 8.5.1(C), sctpimpguide 2.41.
196 * C) Rules for packet carrying SHUTDOWN COMPLETE:
198 * - The receiver of a SHUTDOWN COMPLETE shall accept the packet
199 * if the Verification Tag field of the packet matches its own tag and
200 * the T bit is not set
202 * it is set to its peer's tag and the T bit is set in the Chunk
204 * Otherwise, the receiver MUST silently discard the packet
205 * and take no further action. An endpoint MUST ignore the
206 * SHUTDOWN COMPLETE if it is not in the SHUTDOWN-ACK-SENT state.
209 * (endpoint, asoc, chunk)
212 * (asoc, reply_msg, msg_up, timers, counters)
214 * The return value is the disposition of the chunk.
216 sctp_disposition_t
sctp_sf_do_4_C(struct net
*net
,
217 const struct sctp_endpoint
*ep
,
218 const struct sctp_association
*asoc
,
219 const sctp_subtype_t type
,
221 sctp_cmd_seq_t
*commands
)
223 struct sctp_chunk
*chunk
= arg
;
224 struct sctp_ulpevent
*ev
;
226 if (!sctp_vtag_verify_either(chunk
, asoc
))
227 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
229 /* RFC 2960 6.10 Bundling
231 * An endpoint MUST NOT bundle INIT, INIT ACK or
232 * SHUTDOWN COMPLETE with any other chunks.
234 if (!chunk
->singleton
)
235 return sctp_sf_violation_chunk(net
, ep
, asoc
, type
, arg
, commands
);
237 /* Make sure that the SHUTDOWN_COMPLETE chunk has a valid length. */
238 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_chunkhdr
)))
239 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
242 /* RFC 2960 10.2 SCTP-to-ULP
244 * H) SHUTDOWN COMPLETE notification
246 * When SCTP completes the shutdown procedures (section 9.2) this
247 * notification is passed to the upper layer.
249 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_SHUTDOWN_COMP
,
250 0, 0, 0, NULL
, GFP_ATOMIC
);
252 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
255 /* Upon reception of the SHUTDOWN COMPLETE chunk the endpoint
256 * will verify that it is in SHUTDOWN-ACK-SENT state, if it is
257 * not the chunk should be discarded. If the endpoint is in
258 * the SHUTDOWN-ACK-SENT state the endpoint should stop the
259 * T2-shutdown timer and remove all knowledge of the
260 * association (and thus the association enters the CLOSED
263 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
264 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
266 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
267 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
269 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
270 SCTP_STATE(SCTP_STATE_CLOSED
));
272 SCTP_INC_STATS(net
, SCTP_MIB_SHUTDOWNS
);
273 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
275 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
277 return SCTP_DISPOSITION_DELETE_TCB
;
281 * Respond to a normal INIT chunk.
282 * We are the side that is being asked for an association.
284 * Section: 5.1 Normal Establishment of an Association, B
285 * B) "Z" shall respond immediately with an INIT ACK chunk. The
286 * destination IP address of the INIT ACK MUST be set to the source
287 * IP address of the INIT to which this INIT ACK is responding. In
288 * the response, besides filling in other parameters, "Z" must set the
289 * Verification Tag field to Tag_A, and also provide its own
290 * Verification Tag (Tag_Z) in the Initiate Tag field.
292 * Verification Tag: Must be 0.
295 * (endpoint, asoc, chunk)
298 * (asoc, reply_msg, msg_up, timers, counters)
300 * The return value is the disposition of the chunk.
302 sctp_disposition_t
sctp_sf_do_5_1B_init(struct net
*net
,
303 const struct sctp_endpoint
*ep
,
304 const struct sctp_association
*asoc
,
305 const sctp_subtype_t type
,
307 sctp_cmd_seq_t
*commands
)
309 struct sctp_chunk
*chunk
= arg
;
310 struct sctp_chunk
*repl
;
311 struct sctp_association
*new_asoc
;
312 struct sctp_chunk
*err_chunk
;
313 struct sctp_packet
*packet
;
314 sctp_unrecognized_param_t
*unk_param
;
318 * An endpoint MUST NOT bundle INIT, INIT ACK or
319 * SHUTDOWN COMPLETE with any other chunks.
322 * Furthermore, we require that the receiver of an INIT chunk MUST
323 * enforce these rules by silently discarding an arriving packet
324 * with an INIT chunk that is bundled with other chunks.
326 if (!chunk
->singleton
)
327 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
329 /* If the packet is an OOTB packet which is temporarily on the
330 * control endpoint, respond with an ABORT.
332 if (ep
== sctp_sk(net
->sctp
.ctl_sock
)->ep
) {
333 SCTP_INC_STATS(net
, SCTP_MIB_OUTOFBLUES
);
334 return sctp_sf_tabort_8_4_8(net
, ep
, asoc
, type
, arg
, commands
);
337 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
340 if (chunk
->sctp_hdr
->vtag
!= 0)
341 return sctp_sf_tabort_8_4_8(net
, ep
, asoc
, type
, arg
, commands
);
343 /* Make sure that the INIT chunk has a valid length.
344 * Normally, this would cause an ABORT with a Protocol Violation
345 * error, but since we don't have an association, we'll
346 * just discard the packet.
348 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_init_chunk_t
)))
349 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
351 /* If the INIT is coming toward a closing socket, we'll send back
352 * and ABORT. Essentially, this catches the race of INIT being
353 * backloged to the socket at the same time as the user isses close().
354 * Since the socket and all its associations are going away, we
355 * can treat this OOTB
357 if (sctp_sstate(ep
->base
.sk
, CLOSING
))
358 return sctp_sf_tabort_8_4_8(net
, ep
, asoc
, type
, arg
, commands
);
360 /* Verify the INIT chunk before processing it. */
362 if (!sctp_verify_init(net
, ep
, asoc
, chunk
->chunk_hdr
->type
,
363 (sctp_init_chunk_t
*)chunk
->chunk_hdr
, chunk
,
365 /* This chunk contains fatal error. It is to be discarded.
366 * Send an ABORT, with causes if there is any.
369 packet
= sctp_abort_pkt_new(net
, ep
, asoc
, arg
,
370 (__u8
*)(err_chunk
->chunk_hdr
) +
371 sizeof(struct sctp_chunkhdr
),
372 ntohs(err_chunk
->chunk_hdr
->length
) -
373 sizeof(struct sctp_chunkhdr
));
375 sctp_chunk_free(err_chunk
);
378 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
379 SCTP_PACKET(packet
));
380 SCTP_INC_STATS(net
, SCTP_MIB_OUTCTRLCHUNKS
);
381 return SCTP_DISPOSITION_CONSUME
;
383 return SCTP_DISPOSITION_NOMEM
;
386 return sctp_sf_tabort_8_4_8(net
, ep
, asoc
, type
, arg
,
391 /* Grab the INIT header. */
392 chunk
->subh
.init_hdr
= (sctp_inithdr_t
*)chunk
->skb
->data
;
394 /* Tag the variable length parameters. */
395 chunk
->param_hdr
.v
= skb_pull(chunk
->skb
, sizeof(sctp_inithdr_t
));
397 new_asoc
= sctp_make_temp_asoc(ep
, chunk
, GFP_ATOMIC
);
401 if (sctp_assoc_set_bind_addr_from_ep(new_asoc
,
402 sctp_scope(sctp_source(chunk
)),
406 /* The call, sctp_process_init(), can fail on memory allocation. */
407 if (!sctp_process_init(new_asoc
, chunk
, sctp_source(chunk
),
408 (sctp_init_chunk_t
*)chunk
->chunk_hdr
,
412 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
414 /* If there are errors need to be reported for unknown parameters,
415 * make sure to reserve enough room in the INIT ACK for them.
419 len
= ntohs(err_chunk
->chunk_hdr
->length
) -
420 sizeof(struct sctp_chunkhdr
);
422 repl
= sctp_make_init_ack(new_asoc
, chunk
, GFP_ATOMIC
, len
);
426 /* If there are errors need to be reported for unknown parameters,
427 * include them in the outgoing INIT ACK as "Unrecognized parameter"
431 /* Get the "Unrecognized parameter" parameter(s) out of the
432 * ERROR chunk generated by sctp_verify_init(). Since the
433 * error cause code for "unknown parameter" and the
434 * "Unrecognized parameter" type is the same, we can
435 * construct the parameters in INIT ACK by copying the
438 unk_param
= (sctp_unrecognized_param_t
*)
439 ((__u8
*)(err_chunk
->chunk_hdr
) +
440 sizeof(struct sctp_chunkhdr
));
441 /* Replace the cause code with the "Unrecognized parameter"
444 sctp_addto_chunk(repl
, len
, unk_param
);
445 sctp_chunk_free(err_chunk
);
448 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(new_asoc
));
450 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
453 * Note: After sending out INIT ACK with the State Cookie parameter,
454 * "Z" MUST NOT allocate any resources, nor keep any states for the
455 * new association. Otherwise, "Z" will be vulnerable to resource
458 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
460 return SCTP_DISPOSITION_DELETE_TCB
;
463 sctp_association_free(new_asoc
);
466 sctp_chunk_free(err_chunk
);
467 return SCTP_DISPOSITION_NOMEM
;
471 * Respond to a normal INIT ACK chunk.
472 * We are the side that is initiating the association.
474 * Section: 5.1 Normal Establishment of an Association, C
475 * C) Upon reception of the INIT ACK from "Z", "A" shall stop the T1-init
476 * timer and leave COOKIE-WAIT state. "A" shall then send the State
477 * Cookie received in the INIT ACK chunk in a COOKIE ECHO chunk, start
478 * the T1-cookie timer, and enter the COOKIE-ECHOED state.
480 * Note: The COOKIE ECHO chunk can be bundled with any pending outbound
481 * DATA chunks, but it MUST be the first chunk in the packet and
482 * until the COOKIE ACK is returned the sender MUST NOT send any
483 * other packets to the peer.
485 * Verification Tag: 3.3.3
486 * If the value of the Initiate Tag in a received INIT ACK chunk is
487 * found to be 0, the receiver MUST treat it as an error and close the
488 * association by transmitting an ABORT.
491 * (endpoint, asoc, chunk)
494 * (asoc, reply_msg, msg_up, timers, counters)
496 * The return value is the disposition of the chunk.
498 sctp_disposition_t
sctp_sf_do_5_1C_ack(struct net
*net
,
499 const struct sctp_endpoint
*ep
,
500 const struct sctp_association
*asoc
,
501 const sctp_subtype_t type
,
503 sctp_cmd_seq_t
*commands
)
505 struct sctp_chunk
*chunk
= arg
;
506 sctp_init_chunk_t
*initchunk
;
507 struct sctp_chunk
*err_chunk
;
508 struct sctp_packet
*packet
;
510 if (!sctp_vtag_verify(chunk
, asoc
))
511 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
514 * An endpoint MUST NOT bundle INIT, INIT ACK or
515 * SHUTDOWN COMPLETE with any other chunks.
517 if (!chunk
->singleton
)
518 return sctp_sf_violation_chunk(net
, ep
, asoc
, type
, arg
, commands
);
520 /* Make sure that the INIT-ACK chunk has a valid length */
521 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_initack_chunk_t
)))
522 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
524 /* Grab the INIT header. */
525 chunk
->subh
.init_hdr
= (sctp_inithdr_t
*) chunk
->skb
->data
;
527 /* Verify the INIT chunk before processing it. */
529 if (!sctp_verify_init(net
, ep
, asoc
, chunk
->chunk_hdr
->type
,
530 (sctp_init_chunk_t
*)chunk
->chunk_hdr
, chunk
,
533 sctp_error_t error
= SCTP_ERROR_NO_RESOURCE
;
535 /* This chunk contains fatal error. It is to be discarded.
536 * Send an ABORT, with causes. If there are no causes,
537 * then there wasn't enough memory. Just terminate
541 packet
= sctp_abort_pkt_new(net
, ep
, asoc
, arg
,
542 (__u8
*)(err_chunk
->chunk_hdr
) +
543 sizeof(struct sctp_chunkhdr
),
544 ntohs(err_chunk
->chunk_hdr
->length
) -
545 sizeof(struct sctp_chunkhdr
));
547 sctp_chunk_free(err_chunk
);
550 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
551 SCTP_PACKET(packet
));
552 SCTP_INC_STATS(net
, SCTP_MIB_OUTCTRLCHUNKS
);
553 error
= SCTP_ERROR_INV_PARAM
;
557 /* SCTP-AUTH, Section 6.3:
558 * It should be noted that if the receiver wants to tear
559 * down an association in an authenticated way only, the
560 * handling of malformed packets should not result in
561 * tearing down the association.
563 * This means that if we only want to abort associations
564 * in an authenticated way (i.e AUTH+ABORT), then we
565 * can't destroy this association just because the packet
568 if (sctp_auth_recv_cid(SCTP_CID_ABORT
, asoc
))
569 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
571 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
572 return sctp_stop_t1_and_abort(net
, commands
, error
, ECONNREFUSED
,
573 asoc
, chunk
->transport
);
576 /* Tag the variable length parameters. Note that we never
577 * convert the parameters in an INIT chunk.
579 chunk
->param_hdr
.v
= skb_pull(chunk
->skb
, sizeof(sctp_inithdr_t
));
581 initchunk
= (sctp_init_chunk_t
*) chunk
->chunk_hdr
;
583 sctp_add_cmd_sf(commands
, SCTP_CMD_PEER_INIT
,
584 SCTP_PEER_INIT(initchunk
));
586 /* Reset init error count upon receipt of INIT-ACK. */
587 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_COUNTER_RESET
, SCTP_NULL());
589 /* 5.1 C) "A" shall stop the T1-init timer and leave
590 * COOKIE-WAIT state. "A" shall then ... start the T1-cookie
591 * timer, and enter the COOKIE-ECHOED state.
593 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
594 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
595 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
596 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
597 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
598 SCTP_STATE(SCTP_STATE_COOKIE_ECHOED
));
600 /* SCTP-AUTH: genereate the assocition shared keys so that
601 * we can potentially signe the COOKIE-ECHO.
603 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_SHKEY
, SCTP_NULL());
605 /* 5.1 C) "A" shall then send the State Cookie received in the
606 * INIT ACK chunk in a COOKIE ECHO chunk, ...
608 /* If there is any errors to report, send the ERROR chunk generated
609 * for unknown parameters as well.
611 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_COOKIE_ECHO
,
612 SCTP_CHUNK(err_chunk
));
614 return SCTP_DISPOSITION_CONSUME
;
618 * Respond to a normal COOKIE ECHO chunk.
619 * We are the side that is being asked for an association.
621 * Section: 5.1 Normal Establishment of an Association, D
622 * D) Upon reception of the COOKIE ECHO chunk, Endpoint "Z" will reply
623 * with a COOKIE ACK chunk after building a TCB and moving to
624 * the ESTABLISHED state. A COOKIE ACK chunk may be bundled with
625 * any pending DATA chunks (and/or SACK chunks), but the COOKIE ACK
626 * chunk MUST be the first chunk in the packet.
628 * IMPLEMENTATION NOTE: An implementation may choose to send the
629 * Communication Up notification to the SCTP user upon reception
630 * of a valid COOKIE ECHO chunk.
632 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
633 * D) Rules for packet carrying a COOKIE ECHO
635 * - When sending a COOKIE ECHO, the endpoint MUST use the value of the
636 * Initial Tag received in the INIT ACK.
638 * - The receiver of a COOKIE ECHO follows the procedures in Section 5.
641 * (endpoint, asoc, chunk)
644 * (asoc, reply_msg, msg_up, timers, counters)
646 * The return value is the disposition of the chunk.
648 sctp_disposition_t
sctp_sf_do_5_1D_ce(struct net
*net
,
649 const struct sctp_endpoint
*ep
,
650 const struct sctp_association
*asoc
,
651 const sctp_subtype_t type
, void *arg
,
652 sctp_cmd_seq_t
*commands
)
654 struct sctp_chunk
*chunk
= arg
;
655 struct sctp_association
*new_asoc
;
656 sctp_init_chunk_t
*peer_init
;
657 struct sctp_chunk
*repl
;
658 struct sctp_ulpevent
*ev
, *ai_ev
= NULL
;
660 struct sctp_chunk
*err_chk_p
;
663 /* If the packet is an OOTB packet which is temporarily on the
664 * control endpoint, respond with an ABORT.
666 if (ep
== sctp_sk(net
->sctp
.ctl_sock
)->ep
) {
667 SCTP_INC_STATS(net
, SCTP_MIB_OUTOFBLUES
);
668 return sctp_sf_tabort_8_4_8(net
, ep
, asoc
, type
, arg
, commands
);
671 /* Make sure that the COOKIE_ECHO chunk has a valid length.
672 * In this case, we check that we have enough for at least a
673 * chunk header. More detailed verification is done
674 * in sctp_unpack_cookie().
676 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_chunkhdr
)))
677 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
679 /* If the endpoint is not listening or if the number of associations
680 * on the TCP-style socket exceed the max backlog, respond with an
684 if (!sctp_sstate(sk
, LISTENING
) ||
685 (sctp_style(sk
, TCP
) && sk_acceptq_is_full(sk
)))
686 return sctp_sf_tabort_8_4_8(net
, ep
, asoc
, type
, arg
, commands
);
688 /* "Decode" the chunk. We have no optional parameters so we
691 chunk
->subh
.cookie_hdr
=
692 (struct sctp_signed_cookie
*)chunk
->skb
->data
;
693 if (!pskb_pull(chunk
->skb
, ntohs(chunk
->chunk_hdr
->length
) -
694 sizeof(struct sctp_chunkhdr
)))
697 /* 5.1 D) Upon reception of the COOKIE ECHO chunk, Endpoint
698 * "Z" will reply with a COOKIE ACK chunk after building a TCB
699 * and moving to the ESTABLISHED state.
701 new_asoc
= sctp_unpack_cookie(ep
, asoc
, chunk
, GFP_ATOMIC
, &error
,
705 * If the re-build failed, what is the proper error path
708 * [We should abort the association. --piggy]
711 /* FIXME: Several errors are possible. A bad cookie should
712 * be silently discarded, but think about logging it too.
715 case -SCTP_IERROR_NOMEM
:
718 case -SCTP_IERROR_STALE_COOKIE
:
719 sctp_send_stale_cookie_err(net
, ep
, asoc
, chunk
, commands
,
721 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
723 case -SCTP_IERROR_BAD_SIG
:
725 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
730 /* Delay state machine commands until later.
732 * Re-build the bind address for the association is done in
733 * the sctp_unpack_cookie() already.
735 /* This is a brand-new association, so these are not yet side
736 * effects--it is safe to run them here.
738 peer_init
= &chunk
->subh
.cookie_hdr
->c
.peer_init
[0];
740 if (!sctp_process_init(new_asoc
, chunk
,
741 &chunk
->subh
.cookie_hdr
->c
.peer_addr
,
742 peer_init
, GFP_ATOMIC
))
745 /* SCTP-AUTH: Now that we've populate required fields in
746 * sctp_process_init, set up the assocaition shared keys as
747 * necessary so that we can potentially authenticate the ACK
749 error
= sctp_auth_asoc_init_active_key(new_asoc
, GFP_ATOMIC
);
753 /* SCTP-AUTH: auth_chunk pointer is only set when the cookie-echo
754 * is supposed to be authenticated and we have to do delayed
755 * authentication. We've just recreated the association using
756 * the information in the cookie and now it's much easier to
757 * do the authentication.
759 if (chunk
->auth_chunk
) {
760 struct sctp_chunk auth
;
763 /* Make sure that we and the peer are AUTH capable */
764 if (!net
->sctp
.auth_enable
|| !new_asoc
->peer
.auth_capable
) {
765 sctp_association_free(new_asoc
);
766 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
769 /* set-up our fake chunk so that we can process it */
770 auth
.skb
= chunk
->auth_chunk
;
771 auth
.asoc
= chunk
->asoc
;
772 auth
.sctp_hdr
= chunk
->sctp_hdr
;
773 auth
.chunk_hdr
= (struct sctp_chunkhdr
*)
774 skb_push(chunk
->auth_chunk
,
775 sizeof(struct sctp_chunkhdr
));
776 skb_pull(chunk
->auth_chunk
, sizeof(struct sctp_chunkhdr
));
777 auth
.transport
= chunk
->transport
;
779 ret
= sctp_sf_authenticate(net
, ep
, new_asoc
, type
, &auth
);
780 if (ret
!= SCTP_IERROR_NO_ERROR
) {
781 sctp_association_free(new_asoc
);
782 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
786 repl
= sctp_make_cookie_ack(new_asoc
, chunk
);
790 /* RFC 2960 5.1 Normal Establishment of an Association
792 * D) IMPLEMENTATION NOTE: An implementation may choose to
793 * send the Communication Up notification to the SCTP user
794 * upon reception of a valid COOKIE ECHO chunk.
796 ev
= sctp_ulpevent_make_assoc_change(new_asoc
, 0, SCTP_COMM_UP
, 0,
797 new_asoc
->c
.sinit_num_ostreams
,
798 new_asoc
->c
.sinit_max_instreams
,
803 /* Sockets API Draft Section 5.3.1.6
804 * When a peer sends a Adaptation Layer Indication parameter , SCTP
805 * delivers this notification to inform the application that of the
806 * peers requested adaptation layer.
808 if (new_asoc
->peer
.adaptation_ind
) {
809 ai_ev
= sctp_ulpevent_make_adaptation_indication(new_asoc
,
815 /* Add all the state machine commands now since we've created
816 * everything. This way we don't introduce memory corruptions
817 * during side-effect processing and correclty count established
820 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(new_asoc
));
821 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
822 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
823 SCTP_INC_STATS(net
, SCTP_MIB_CURRESTAB
);
824 SCTP_INC_STATS(net
, SCTP_MIB_PASSIVEESTABS
);
825 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_START
, SCTP_NULL());
827 if (new_asoc
->timeouts
[SCTP_EVENT_TIMEOUT_AUTOCLOSE
])
828 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
829 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
831 /* This will send the COOKIE ACK */
832 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
834 /* Queue the ASSOC_CHANGE event */
835 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
837 /* Send up the Adaptation Layer Indication event */
839 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
840 SCTP_ULPEVENT(ai_ev
));
842 return SCTP_DISPOSITION_CONSUME
;
845 sctp_ulpevent_free(ev
);
847 sctp_chunk_free(repl
);
849 sctp_association_free(new_asoc
);
851 return SCTP_DISPOSITION_NOMEM
;
855 * Respond to a normal COOKIE ACK chunk.
856 * We are the side that is asking for an association.
858 * RFC 2960 5.1 Normal Establishment of an Association
860 * E) Upon reception of the COOKIE ACK, endpoint "A" will move from the
861 * COOKIE-ECHOED state to the ESTABLISHED state, stopping the T1-cookie
862 * timer. It may also notify its ULP about the successful
863 * establishment of the association with a Communication Up
864 * notification (see Section 10).
868 * (endpoint, asoc, chunk)
871 * (asoc, reply_msg, msg_up, timers, counters)
873 * The return value is the disposition of the chunk.
875 sctp_disposition_t
sctp_sf_do_5_1E_ca(struct net
*net
,
876 const struct sctp_endpoint
*ep
,
877 const struct sctp_association
*asoc
,
878 const sctp_subtype_t type
, void *arg
,
879 sctp_cmd_seq_t
*commands
)
881 struct sctp_chunk
*chunk
= arg
;
882 struct sctp_ulpevent
*ev
;
884 if (!sctp_vtag_verify(chunk
, asoc
))
885 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
887 /* Verify that the chunk length for the COOKIE-ACK is OK.
888 * If we don't do this, any bundled chunks may be junked.
890 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_chunkhdr
)))
891 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
894 /* Reset init error count upon receipt of COOKIE-ACK,
895 * to avoid problems with the managemement of this
896 * counter in stale cookie situations when a transition back
897 * from the COOKIE-ECHOED state to the COOKIE-WAIT
898 * state is performed.
900 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_COUNTER_RESET
, SCTP_NULL());
902 /* RFC 2960 5.1 Normal Establishment of an Association
904 * E) Upon reception of the COOKIE ACK, endpoint "A" will move
905 * from the COOKIE-ECHOED state to the ESTABLISHED state,
906 * stopping the T1-cookie timer.
908 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
909 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
910 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
911 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
912 SCTP_INC_STATS(net
, SCTP_MIB_CURRESTAB
);
913 SCTP_INC_STATS(net
, SCTP_MIB_ACTIVEESTABS
);
914 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_START
, SCTP_NULL());
915 if (asoc
->timeouts
[SCTP_EVENT_TIMEOUT_AUTOCLOSE
])
916 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
917 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
919 /* It may also notify its ULP about the successful
920 * establishment of the association with a Communication Up
921 * notification (see Section 10).
923 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_COMM_UP
,
924 0, asoc
->c
.sinit_num_ostreams
,
925 asoc
->c
.sinit_max_instreams
,
931 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
933 /* Sockets API Draft Section 5.3.1.6
934 * When a peer sends a Adaptation Layer Indication parameter , SCTP
935 * delivers this notification to inform the application that of the
936 * peers requested adaptation layer.
938 if (asoc
->peer
.adaptation_ind
) {
939 ev
= sctp_ulpevent_make_adaptation_indication(asoc
, GFP_ATOMIC
);
943 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
947 return SCTP_DISPOSITION_CONSUME
;
949 return SCTP_DISPOSITION_NOMEM
;
952 /* Generate and sendout a heartbeat packet. */
953 static sctp_disposition_t
sctp_sf_heartbeat(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
;
960 struct sctp_chunk
*reply
;
962 /* Send a heartbeat to our peer. */
963 reply
= sctp_make_heartbeat(asoc
, transport
);
965 return SCTP_DISPOSITION_NOMEM
;
967 /* Set rto_pending indicating that an RTT measurement
968 * is started with this heartbeat chunk.
970 sctp_add_cmd_sf(commands
, SCTP_CMD_RTO_PENDING
,
971 SCTP_TRANSPORT(transport
));
973 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
974 return SCTP_DISPOSITION_CONSUME
;
977 /* Generate a HEARTBEAT packet on the given transport. */
978 sctp_disposition_t
sctp_sf_sendbeat_8_3(struct net
*net
,
979 const struct sctp_endpoint
*ep
,
980 const struct sctp_association
*asoc
,
981 const sctp_subtype_t type
,
983 sctp_cmd_seq_t
*commands
)
985 struct sctp_transport
*transport
= (struct sctp_transport
*) arg
;
987 if (asoc
->overall_error_count
>= asoc
->max_retrans
) {
988 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
989 SCTP_ERROR(ETIMEDOUT
));
990 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
991 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
992 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
993 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
994 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
995 return SCTP_DISPOSITION_DELETE_TCB
;
999 * The Sender-specific Heartbeat Info field should normally include
1000 * information about the sender's current time when this HEARTBEAT
1001 * chunk is sent and the destination transport address to which this
1002 * HEARTBEAT is sent (see Section 8.3).
1005 if (transport
->param_flags
& SPP_HB_ENABLE
) {
1006 if (SCTP_DISPOSITION_NOMEM
==
1007 sctp_sf_heartbeat(ep
, asoc
, type
, arg
,
1009 return SCTP_DISPOSITION_NOMEM
;
1011 /* Set transport error counter and association error counter
1012 * when sending heartbeat.
1014 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSPORT_HB_SENT
,
1015 SCTP_TRANSPORT(transport
));
1017 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSPORT_IDLE
,
1018 SCTP_TRANSPORT(transport
));
1019 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMER_UPDATE
,
1020 SCTP_TRANSPORT(transport
));
1022 return SCTP_DISPOSITION_CONSUME
;
1025 /* resend asoc strreset_chunk. */
1026 sctp_disposition_t
sctp_sf_send_reconf(struct net
*net
,
1027 const struct sctp_endpoint
*ep
,
1028 const struct sctp_association
*asoc
,
1029 const sctp_subtype_t type
, void *arg
,
1030 sctp_cmd_seq_t
*commands
)
1032 struct sctp_transport
*transport
= arg
;
1034 if (asoc
->overall_error_count
>= asoc
->max_retrans
) {
1035 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
1036 SCTP_ERROR(ETIMEDOUT
));
1037 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
1038 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
1039 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
1040 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
1041 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
1042 return SCTP_DISPOSITION_DELETE_TCB
;
1045 sctp_chunk_hold(asoc
->strreset_chunk
);
1046 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
1047 SCTP_CHUNK(asoc
->strreset_chunk
));
1048 sctp_add_cmd_sf(commands
, SCTP_CMD_STRIKE
, SCTP_TRANSPORT(transport
));
1050 return SCTP_DISPOSITION_CONSUME
;
1054 * Process an heartbeat request.
1056 * Section: 8.3 Path Heartbeat
1057 * The receiver of the HEARTBEAT should immediately respond with a
1058 * HEARTBEAT ACK that contains the Heartbeat Information field copied
1059 * from the received HEARTBEAT chunk.
1061 * Verification Tag: 8.5 Verification Tag [Normal verification]
1062 * When receiving an SCTP packet, the endpoint MUST ensure that the
1063 * value in the Verification Tag field of the received SCTP packet
1064 * matches its own Tag. If the received Verification Tag value does not
1065 * match the receiver's own tag value, the receiver shall silently
1066 * discard the packet and shall not process it any further except for
1067 * those cases listed in Section 8.5.1 below.
1070 * (endpoint, asoc, chunk)
1073 * (asoc, reply_msg, msg_up, timers, counters)
1075 * The return value is the disposition of the chunk.
1077 sctp_disposition_t
sctp_sf_beat_8_3(struct net
*net
,
1078 const struct sctp_endpoint
*ep
,
1079 const struct sctp_association
*asoc
,
1080 const sctp_subtype_t type
,
1082 sctp_cmd_seq_t
*commands
)
1084 struct sctp_paramhdr
*param_hdr
;
1085 struct sctp_chunk
*chunk
= arg
;
1086 struct sctp_chunk
*reply
;
1089 if (!sctp_vtag_verify(chunk
, asoc
))
1090 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
1092 /* Make sure that the HEARTBEAT chunk has a valid length. */
1093 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_heartbeat_chunk_t
)))
1094 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
1097 /* 8.3 The receiver of the HEARTBEAT should immediately
1098 * respond with a HEARTBEAT ACK that contains the Heartbeat
1099 * Information field copied from the received HEARTBEAT chunk.
1101 chunk
->subh
.hb_hdr
= (sctp_heartbeathdr_t
*)chunk
->skb
->data
;
1102 param_hdr
= (struct sctp_paramhdr
*)chunk
->subh
.hb_hdr
;
1103 paylen
= ntohs(chunk
->chunk_hdr
->length
) - sizeof(struct sctp_chunkhdr
);
1105 if (ntohs(param_hdr
->length
) > paylen
)
1106 return sctp_sf_violation_paramlen(net
, ep
, asoc
, type
, arg
,
1107 param_hdr
, commands
);
1109 if (!pskb_pull(chunk
->skb
, paylen
))
1112 reply
= sctp_make_heartbeat_ack(asoc
, chunk
, param_hdr
, paylen
);
1116 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
1117 return SCTP_DISPOSITION_CONSUME
;
1120 return SCTP_DISPOSITION_NOMEM
;
1124 * Process the returning HEARTBEAT ACK.
1126 * Section: 8.3 Path Heartbeat
1127 * Upon the receipt of the HEARTBEAT ACK, the sender of the HEARTBEAT
1128 * should clear the error counter of the destination transport
1129 * address to which the HEARTBEAT was sent, and mark the destination
1130 * transport address as active if it is not so marked. The endpoint may
1131 * optionally report to the upper layer when an inactive destination
1132 * address is marked as active due to the reception of the latest
1133 * HEARTBEAT ACK. The receiver of the HEARTBEAT ACK must also
1134 * clear the association overall error count as well (as defined
1137 * The receiver of the HEARTBEAT ACK should also perform an RTT
1138 * measurement for that destination transport address using the time
1139 * value carried in the HEARTBEAT ACK chunk.
1141 * Verification Tag: 8.5 Verification Tag [Normal verification]
1144 * (endpoint, asoc, chunk)
1147 * (asoc, reply_msg, msg_up, timers, counters)
1149 * The return value is the disposition of the chunk.
1151 sctp_disposition_t
sctp_sf_backbeat_8_3(struct net
*net
,
1152 const struct sctp_endpoint
*ep
,
1153 const struct sctp_association
*asoc
,
1154 const sctp_subtype_t type
,
1156 sctp_cmd_seq_t
*commands
)
1158 struct sctp_chunk
*chunk
= arg
;
1159 union sctp_addr from_addr
;
1160 struct sctp_transport
*link
;
1161 sctp_sender_hb_info_t
*hbinfo
;
1162 unsigned long max_interval
;
1164 if (!sctp_vtag_verify(chunk
, asoc
))
1165 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
1167 /* Make sure that the HEARTBEAT-ACK chunk has a valid length. */
1168 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_chunkhdr
) +
1169 sizeof(sctp_sender_hb_info_t
)))
1170 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
1173 hbinfo
= (sctp_sender_hb_info_t
*) chunk
->skb
->data
;
1174 /* Make sure that the length of the parameter is what we expect */
1175 if (ntohs(hbinfo
->param_hdr
.length
) !=
1176 sizeof(sctp_sender_hb_info_t
)) {
1177 return SCTP_DISPOSITION_DISCARD
;
1180 from_addr
= hbinfo
->daddr
;
1181 link
= sctp_assoc_lookup_paddr(asoc
, &from_addr
);
1183 /* This should never happen, but lets log it if so. */
1184 if (unlikely(!link
)) {
1185 if (from_addr
.sa
.sa_family
== AF_INET6
) {
1186 net_warn_ratelimited("%s association %p could not find address %pI6\n",
1189 &from_addr
.v6
.sin6_addr
);
1191 net_warn_ratelimited("%s association %p could not find address %pI4\n",
1194 &from_addr
.v4
.sin_addr
.s_addr
);
1196 return SCTP_DISPOSITION_DISCARD
;
1199 /* Validate the 64-bit random nonce. */
1200 if (hbinfo
->hb_nonce
!= link
->hb_nonce
)
1201 return SCTP_DISPOSITION_DISCARD
;
1203 max_interval
= link
->hbinterval
+ link
->rto
;
1205 /* Check if the timestamp looks valid. */
1206 if (time_after(hbinfo
->sent_at
, jiffies
) ||
1207 time_after(jiffies
, hbinfo
->sent_at
+ max_interval
)) {
1208 pr_debug("%s: HEARTBEAT ACK with invalid timestamp received "
1209 "for transport:%p\n", __func__
, link
);
1211 return SCTP_DISPOSITION_DISCARD
;
1214 /* 8.3 Upon the receipt of the HEARTBEAT ACK, the sender of
1215 * the HEARTBEAT should clear the error counter of the
1216 * destination transport address to which the HEARTBEAT was
1217 * sent and mark the destination transport address as active if
1218 * it is not so marked.
1220 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSPORT_ON
, SCTP_TRANSPORT(link
));
1222 return SCTP_DISPOSITION_CONSUME
;
1225 /* Helper function to send out an abort for the restart
1228 static int sctp_sf_send_restart_abort(struct net
*net
, union sctp_addr
*ssa
,
1229 struct sctp_chunk
*init
,
1230 sctp_cmd_seq_t
*commands
)
1233 struct sctp_packet
*pkt
;
1234 union sctp_addr_param
*addrparm
;
1235 struct sctp_errhdr
*errhdr
;
1236 struct sctp_endpoint
*ep
;
1237 char buffer
[sizeof(struct sctp_errhdr
)+sizeof(union sctp_addr_param
)];
1238 struct sctp_af
*af
= sctp_get_af_specific(ssa
->v4
.sin_family
);
1240 /* Build the error on the stack. We are way to malloc crazy
1241 * throughout the code today.
1243 errhdr
= (struct sctp_errhdr
*)buffer
;
1244 addrparm
= (union sctp_addr_param
*)errhdr
->variable
;
1246 /* Copy into a parm format. */
1247 len
= af
->to_addr_param(ssa
, addrparm
);
1248 len
+= sizeof(sctp_errhdr_t
);
1250 errhdr
->cause
= SCTP_ERROR_RESTART
;
1251 errhdr
->length
= htons(len
);
1253 /* Assign to the control socket. */
1254 ep
= sctp_sk(net
->sctp
.ctl_sock
)->ep
;
1256 /* Association is NULL since this may be a restart attack and we
1257 * want to send back the attacker's vtag.
1259 pkt
= sctp_abort_pkt_new(net
, ep
, NULL
, init
, errhdr
, len
);
1263 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
, SCTP_PACKET(pkt
));
1265 SCTP_INC_STATS(net
, SCTP_MIB_OUTCTRLCHUNKS
);
1267 /* Discard the rest of the inbound packet. */
1268 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
, SCTP_NULL());
1271 /* Even if there is no memory, treat as a failure so
1272 * the packet will get dropped.
1277 static bool list_has_sctp_addr(const struct list_head
*list
,
1278 union sctp_addr
*ipaddr
)
1280 struct sctp_transport
*addr
;
1282 list_for_each_entry(addr
, list
, transports
) {
1283 if (sctp_cmp_addr_exact(ipaddr
, &addr
->ipaddr
))
1289 /* A restart is occurring, check to make sure no new addresses
1290 * are being added as we may be under a takeover attack.
1292 static int sctp_sf_check_restart_addrs(const struct sctp_association
*new_asoc
,
1293 const struct sctp_association
*asoc
,
1294 struct sctp_chunk
*init
,
1295 sctp_cmd_seq_t
*commands
)
1297 struct net
*net
= sock_net(new_asoc
->base
.sk
);
1298 struct sctp_transport
*new_addr
;
1301 /* Implementor's Guide - Section 5.2.2
1303 * Before responding the endpoint MUST check to see if the
1304 * unexpected INIT adds new addresses to the association. If new
1305 * addresses are added to the association, the endpoint MUST respond
1309 /* Search through all current addresses and make sure
1310 * we aren't adding any new ones.
1312 list_for_each_entry(new_addr
, &new_asoc
->peer
.transport_addr_list
,
1314 if (!list_has_sctp_addr(&asoc
->peer
.transport_addr_list
,
1315 &new_addr
->ipaddr
)) {
1316 sctp_sf_send_restart_abort(net
, &new_addr
->ipaddr
, init
,
1323 /* Return success if all addresses were found. */
1327 /* Populate the verification/tie tags based on overlapping INIT
1330 * Note: Do not use in CLOSED or SHUTDOWN-ACK-SENT state.
1332 static void sctp_tietags_populate(struct sctp_association
*new_asoc
,
1333 const struct sctp_association
*asoc
)
1335 switch (asoc
->state
) {
1337 /* 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State */
1339 case SCTP_STATE_COOKIE_WAIT
:
1340 new_asoc
->c
.my_vtag
= asoc
->c
.my_vtag
;
1341 new_asoc
->c
.my_ttag
= asoc
->c
.my_vtag
;
1342 new_asoc
->c
.peer_ttag
= 0;
1345 case SCTP_STATE_COOKIE_ECHOED
:
1346 new_asoc
->c
.my_vtag
= asoc
->c
.my_vtag
;
1347 new_asoc
->c
.my_ttag
= asoc
->c
.my_vtag
;
1348 new_asoc
->c
.peer_ttag
= asoc
->c
.peer_vtag
;
1351 /* 5.2.2 Unexpected INIT in States Other than CLOSED, COOKIE-ECHOED,
1352 * COOKIE-WAIT and SHUTDOWN-ACK-SENT
1355 new_asoc
->c
.my_ttag
= asoc
->c
.my_vtag
;
1356 new_asoc
->c
.peer_ttag
= asoc
->c
.peer_vtag
;
1360 /* Other parameters for the endpoint SHOULD be copied from the
1361 * existing parameters of the association (e.g. number of
1362 * outbound streams) into the INIT ACK and cookie.
1364 new_asoc
->rwnd
= asoc
->rwnd
;
1365 new_asoc
->c
.sinit_num_ostreams
= asoc
->c
.sinit_num_ostreams
;
1366 new_asoc
->c
.sinit_max_instreams
= asoc
->c
.sinit_max_instreams
;
1367 new_asoc
->c
.initial_tsn
= asoc
->c
.initial_tsn
;
1371 * Compare vtag/tietag values to determine unexpected COOKIE-ECHO
1374 * RFC 2960 5.2.4 Handle a COOKIE ECHO when a TCB exists.
1376 * Returns value representing action to be taken. These action values
1377 * correspond to Action/Description values in RFC 2960, Table 2.
1379 static char sctp_tietags_compare(struct sctp_association
*new_asoc
,
1380 const struct sctp_association
*asoc
)
1382 /* In this case, the peer may have restarted. */
1383 if ((asoc
->c
.my_vtag
!= new_asoc
->c
.my_vtag
) &&
1384 (asoc
->c
.peer_vtag
!= new_asoc
->c
.peer_vtag
) &&
1385 (asoc
->c
.my_vtag
== new_asoc
->c
.my_ttag
) &&
1386 (asoc
->c
.peer_vtag
== new_asoc
->c
.peer_ttag
))
1389 /* Collision case B. */
1390 if ((asoc
->c
.my_vtag
== new_asoc
->c
.my_vtag
) &&
1391 ((asoc
->c
.peer_vtag
!= new_asoc
->c
.peer_vtag
) ||
1392 (0 == asoc
->c
.peer_vtag
))) {
1396 /* Collision case D. */
1397 if ((asoc
->c
.my_vtag
== new_asoc
->c
.my_vtag
) &&
1398 (asoc
->c
.peer_vtag
== new_asoc
->c
.peer_vtag
))
1401 /* Collision case C. */
1402 if ((asoc
->c
.my_vtag
!= new_asoc
->c
.my_vtag
) &&
1403 (asoc
->c
.peer_vtag
== new_asoc
->c
.peer_vtag
) &&
1404 (0 == new_asoc
->c
.my_ttag
) &&
1405 (0 == new_asoc
->c
.peer_ttag
))
1408 /* No match to any of the special cases; discard this packet. */
1412 /* Common helper routine for both duplicate and simulataneous INIT
1415 static sctp_disposition_t
sctp_sf_do_unexpected_init(
1417 const struct sctp_endpoint
*ep
,
1418 const struct sctp_association
*asoc
,
1419 const sctp_subtype_t type
,
1420 void *arg
, sctp_cmd_seq_t
*commands
)
1422 sctp_disposition_t retval
;
1423 struct sctp_chunk
*chunk
= arg
;
1424 struct sctp_chunk
*repl
;
1425 struct sctp_association
*new_asoc
;
1426 struct sctp_chunk
*err_chunk
;
1427 struct sctp_packet
*packet
;
1428 sctp_unrecognized_param_t
*unk_param
;
1432 * An endpoint MUST NOT bundle INIT, INIT ACK or
1433 * SHUTDOWN COMPLETE with any other chunks.
1436 * Furthermore, we require that the receiver of an INIT chunk MUST
1437 * enforce these rules by silently discarding an arriving packet
1438 * with an INIT chunk that is bundled with other chunks.
1440 if (!chunk
->singleton
)
1441 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
1443 /* 3.1 A packet containing an INIT chunk MUST have a zero Verification
1446 if (chunk
->sctp_hdr
->vtag
!= 0)
1447 return sctp_sf_tabort_8_4_8(net
, ep
, asoc
, type
, arg
, commands
);
1449 /* Make sure that the INIT chunk has a valid length.
1450 * In this case, we generate a protocol violation since we have
1451 * an association established.
1453 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_init_chunk_t
)))
1454 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
1456 /* Grab the INIT header. */
1457 chunk
->subh
.init_hdr
= (sctp_inithdr_t
*) chunk
->skb
->data
;
1459 /* Tag the variable length parameters. */
1460 chunk
->param_hdr
.v
= skb_pull(chunk
->skb
, sizeof(sctp_inithdr_t
));
1462 /* Verify the INIT chunk before processing it. */
1464 if (!sctp_verify_init(net
, ep
, asoc
, chunk
->chunk_hdr
->type
,
1465 (sctp_init_chunk_t
*)chunk
->chunk_hdr
, chunk
,
1467 /* This chunk contains fatal error. It is to be discarded.
1468 * Send an ABORT, with causes if there is any.
1471 packet
= sctp_abort_pkt_new(net
, ep
, asoc
, arg
,
1472 (__u8
*)(err_chunk
->chunk_hdr
) +
1473 sizeof(struct sctp_chunkhdr
),
1474 ntohs(err_chunk
->chunk_hdr
->length
) -
1475 sizeof(struct sctp_chunkhdr
));
1478 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
1479 SCTP_PACKET(packet
));
1480 SCTP_INC_STATS(net
, SCTP_MIB_OUTCTRLCHUNKS
);
1481 retval
= SCTP_DISPOSITION_CONSUME
;
1483 retval
= SCTP_DISPOSITION_NOMEM
;
1487 return sctp_sf_tabort_8_4_8(net
, ep
, asoc
, type
, arg
,
1493 * Other parameters for the endpoint SHOULD be copied from the
1494 * existing parameters of the association (e.g. number of
1495 * outbound streams) into the INIT ACK and cookie.
1496 * FIXME: We are copying parameters from the endpoint not the
1499 new_asoc
= sctp_make_temp_asoc(ep
, chunk
, GFP_ATOMIC
);
1503 if (sctp_assoc_set_bind_addr_from_ep(new_asoc
,
1504 sctp_scope(sctp_source(chunk
)), GFP_ATOMIC
) < 0)
1507 /* In the outbound INIT ACK the endpoint MUST copy its current
1508 * Verification Tag and Peers Verification tag into a reserved
1509 * place (local tie-tag and per tie-tag) within the state cookie.
1511 if (!sctp_process_init(new_asoc
, chunk
, sctp_source(chunk
),
1512 (sctp_init_chunk_t
*)chunk
->chunk_hdr
,
1516 /* Make sure no new addresses are being added during the
1517 * restart. Do not do this check for COOKIE-WAIT state,
1518 * since there are no peer addresses to check against.
1519 * Upon return an ABORT will have been sent if needed.
1521 if (!sctp_state(asoc
, COOKIE_WAIT
)) {
1522 if (!sctp_sf_check_restart_addrs(new_asoc
, asoc
, chunk
,
1524 retval
= SCTP_DISPOSITION_CONSUME
;
1529 sctp_tietags_populate(new_asoc
, asoc
);
1531 /* B) "Z" shall respond immediately with an INIT ACK chunk. */
1533 /* If there are errors need to be reported for unknown parameters,
1534 * make sure to reserve enough room in the INIT ACK for them.
1538 len
= ntohs(err_chunk
->chunk_hdr
->length
) -
1539 sizeof(struct sctp_chunkhdr
);
1542 repl
= sctp_make_init_ack(new_asoc
, chunk
, GFP_ATOMIC
, len
);
1546 /* If there are errors need to be reported for unknown parameters,
1547 * include them in the outgoing INIT ACK as "Unrecognized parameter"
1551 /* Get the "Unrecognized parameter" parameter(s) out of the
1552 * ERROR chunk generated by sctp_verify_init(). Since the
1553 * error cause code for "unknown parameter" and the
1554 * "Unrecognized parameter" type is the same, we can
1555 * construct the parameters in INIT ACK by copying the
1556 * ERROR causes over.
1558 unk_param
= (sctp_unrecognized_param_t
*)
1559 ((__u8
*)(err_chunk
->chunk_hdr
) +
1560 sizeof(struct sctp_chunkhdr
));
1561 /* Replace the cause code with the "Unrecognized parameter"
1564 sctp_addto_chunk(repl
, len
, unk_param
);
1567 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(new_asoc
));
1568 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1571 * Note: After sending out INIT ACK with the State Cookie parameter,
1572 * "Z" MUST NOT allocate any resources for this new association.
1573 * Otherwise, "Z" will be vulnerable to resource attacks.
1575 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
1576 retval
= SCTP_DISPOSITION_CONSUME
;
1581 retval
= SCTP_DISPOSITION_NOMEM
;
1584 sctp_association_free(new_asoc
);
1587 sctp_chunk_free(err_chunk
);
1592 * Handle simultaneous INIT.
1593 * This means we started an INIT and then we got an INIT request from
1596 * Section: 5.2.1 INIT received in COOKIE-WAIT or COOKIE-ECHOED State (Item B)
1597 * This usually indicates an initialization collision, i.e., each
1598 * endpoint is attempting, at about the same time, to establish an
1599 * association with the other endpoint.
1601 * Upon receipt of an INIT in the COOKIE-WAIT or COOKIE-ECHOED state, an
1602 * endpoint MUST respond with an INIT ACK using the same parameters it
1603 * sent in its original INIT chunk (including its Verification Tag,
1604 * unchanged). These original parameters are combined with those from the
1605 * newly received INIT chunk. The endpoint shall also generate a State
1606 * Cookie with the INIT ACK. The endpoint uses the parameters sent in its
1607 * INIT to calculate the State Cookie.
1609 * After that, the endpoint MUST NOT change its state, the T1-init
1610 * timer shall be left running and the corresponding TCB MUST NOT be
1611 * destroyed. The normal procedures for handling State Cookies when
1612 * a TCB exists will resolve the duplicate INITs to a single association.
1614 * For an endpoint that is in the COOKIE-ECHOED state it MUST populate
1615 * its Tie-Tags with the Tag information of itself and its peer (see
1616 * section 5.2.2 for a description of the Tie-Tags).
1618 * Verification Tag: Not explicit, but an INIT can not have a valid
1619 * verification tag, so we skip the check.
1622 * (endpoint, asoc, chunk)
1625 * (asoc, reply_msg, msg_up, timers, counters)
1627 * The return value is the disposition of the chunk.
1629 sctp_disposition_t
sctp_sf_do_5_2_1_siminit(struct net
*net
,
1630 const struct sctp_endpoint
*ep
,
1631 const struct sctp_association
*asoc
,
1632 const sctp_subtype_t type
,
1634 sctp_cmd_seq_t
*commands
)
1636 /* Call helper to do the real work for both simulataneous and
1637 * duplicate INIT chunk handling.
1639 return sctp_sf_do_unexpected_init(net
, ep
, asoc
, type
, arg
, commands
);
1643 * Handle duplicated INIT messages. These are usually delayed
1646 * Section: 5.2.2 Unexpected INIT in States Other than CLOSED,
1647 * COOKIE-ECHOED and COOKIE-WAIT
1649 * Unless otherwise stated, upon reception of an unexpected INIT for
1650 * this association, the endpoint shall generate an INIT ACK with a
1651 * State Cookie. In the outbound INIT ACK the endpoint MUST copy its
1652 * current Verification Tag and peer's Verification Tag into a reserved
1653 * place within the state cookie. We shall refer to these locations as
1654 * the Peer's-Tie-Tag and the Local-Tie-Tag. The outbound SCTP packet
1655 * containing this INIT ACK MUST carry a Verification Tag value equal to
1656 * the Initiation Tag found in the unexpected INIT. And the INIT ACK
1657 * MUST contain a new Initiation Tag (randomly generated see Section
1658 * 5.3.1). Other parameters for the endpoint SHOULD be copied from the
1659 * existing parameters of the association (e.g. number of outbound
1660 * streams) into the INIT ACK and cookie.
1662 * After sending out the INIT ACK, the endpoint shall take no further
1663 * actions, i.e., the existing association, including its current state,
1664 * and the corresponding TCB MUST NOT be changed.
1666 * Note: Only when a TCB exists and the association is not in a COOKIE-
1667 * WAIT state are the Tie-Tags populated. For a normal association INIT
1668 * (i.e. the endpoint is in a COOKIE-WAIT state), the Tie-Tags MUST be
1669 * set to 0 (indicating that no previous TCB existed). The INIT ACK and
1670 * State Cookie are populated as specified in section 5.2.1.
1672 * Verification Tag: Not specified, but an INIT has no way of knowing
1673 * what the verification tag could be, so we ignore it.
1676 * (endpoint, asoc, chunk)
1679 * (asoc, reply_msg, msg_up, timers, counters)
1681 * The return value is the disposition of the chunk.
1683 sctp_disposition_t
sctp_sf_do_5_2_2_dupinit(struct net
*net
,
1684 const struct sctp_endpoint
*ep
,
1685 const struct sctp_association
*asoc
,
1686 const sctp_subtype_t type
,
1688 sctp_cmd_seq_t
*commands
)
1690 /* Call helper to do the real work for both simulataneous and
1691 * duplicate INIT chunk handling.
1693 return sctp_sf_do_unexpected_init(net
, ep
, asoc
, type
, arg
, commands
);
1698 * Unexpected INIT-ACK handler.
1701 * If an INIT ACK received by an endpoint in any state other than the
1702 * COOKIE-WAIT state, the endpoint should discard the INIT ACK chunk.
1703 * An unexpected INIT ACK usually indicates the processing of an old or
1704 * duplicated INIT chunk.
1706 sctp_disposition_t
sctp_sf_do_5_2_3_initack(struct net
*net
,
1707 const struct sctp_endpoint
*ep
,
1708 const struct sctp_association
*asoc
,
1709 const sctp_subtype_t type
,
1710 void *arg
, sctp_cmd_seq_t
*commands
)
1712 /* Per the above section, we'll discard the chunk if we have an
1713 * endpoint. If this is an OOTB INIT-ACK, treat it as such.
1715 if (ep
== sctp_sk(net
->sctp
.ctl_sock
)->ep
)
1716 return sctp_sf_ootb(net
, ep
, asoc
, type
, arg
, commands
);
1718 return sctp_sf_discard_chunk(net
, ep
, asoc
, type
, arg
, commands
);
1721 /* Unexpected COOKIE-ECHO handler for peer restart (Table 2, action 'A')
1724 * A) In this case, the peer may have restarted.
1726 static sctp_disposition_t
sctp_sf_do_dupcook_a(struct net
*net
,
1727 const struct sctp_endpoint
*ep
,
1728 const struct sctp_association
*asoc
,
1729 struct sctp_chunk
*chunk
,
1730 sctp_cmd_seq_t
*commands
,
1731 struct sctp_association
*new_asoc
)
1733 sctp_init_chunk_t
*peer_init
;
1734 struct sctp_ulpevent
*ev
;
1735 struct sctp_chunk
*repl
;
1736 struct sctp_chunk
*err
;
1737 sctp_disposition_t disposition
;
1739 /* new_asoc is a brand-new association, so these are not yet
1740 * side effects--it is safe to run them here.
1742 peer_init
= &chunk
->subh
.cookie_hdr
->c
.peer_init
[0];
1744 if (!sctp_process_init(new_asoc
, chunk
, sctp_source(chunk
), peer_init
,
1748 /* Make sure no new addresses are being added during the
1749 * restart. Though this is a pretty complicated attack
1750 * since you'd have to get inside the cookie.
1752 if (!sctp_sf_check_restart_addrs(new_asoc
, asoc
, chunk
, commands
)) {
1753 return SCTP_DISPOSITION_CONSUME
;
1756 /* If the endpoint is in the SHUTDOWN-ACK-SENT state and recognizes
1757 * the peer has restarted (Action A), it MUST NOT setup a new
1758 * association but instead resend the SHUTDOWN ACK and send an ERROR
1759 * chunk with a "Cookie Received while Shutting Down" error cause to
1762 if (sctp_state(asoc
, SHUTDOWN_ACK_SENT
)) {
1763 disposition
= sctp_sf_do_9_2_reshutack(net
, ep
, asoc
,
1764 SCTP_ST_CHUNK(chunk
->chunk_hdr
->type
),
1766 if (SCTP_DISPOSITION_NOMEM
== disposition
)
1769 err
= sctp_make_op_error(asoc
, chunk
,
1770 SCTP_ERROR_COOKIE_IN_SHUTDOWN
,
1773 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
1776 return SCTP_DISPOSITION_CONSUME
;
1779 /* For now, stop pending T3-rtx and SACK timers, fail any unsent/unacked
1780 * data. Consider the optional choice of resending of this data.
1782 sctp_add_cmd_sf(commands
, SCTP_CMD_T3_RTX_TIMERS_STOP
, SCTP_NULL());
1783 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
1784 SCTP_TO(SCTP_EVENT_TIMEOUT_SACK
));
1785 sctp_add_cmd_sf(commands
, SCTP_CMD_PURGE_OUTQUEUE
, SCTP_NULL());
1787 /* Stop pending T4-rto timer, teardown ASCONF queue, ASCONF-ACK queue
1788 * and ASCONF-ACK cache.
1790 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
1791 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
1792 sctp_add_cmd_sf(commands
, SCTP_CMD_PURGE_ASCONF_QUEUE
, SCTP_NULL());
1794 repl
= sctp_make_cookie_ack(new_asoc
, chunk
);
1798 /* Report association restart to upper layer. */
1799 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_RESTART
, 0,
1800 new_asoc
->c
.sinit_num_ostreams
,
1801 new_asoc
->c
.sinit_max_instreams
,
1806 /* Update the content of current association. */
1807 sctp_add_cmd_sf(commands
, SCTP_CMD_UPDATE_ASSOC
, SCTP_ASOC(new_asoc
));
1808 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
1809 if (sctp_state(asoc
, SHUTDOWN_PENDING
) &&
1810 (sctp_sstate(asoc
->base
.sk
, CLOSING
) ||
1811 sock_flag(asoc
->base
.sk
, SOCK_DEAD
))) {
1812 /* if were currently in SHUTDOWN_PENDING, but the socket
1813 * has been closed by user, don't transition to ESTABLISHED.
1814 * Instead trigger SHUTDOWN bundled with COOKIE_ACK.
1816 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1817 return sctp_sf_do_9_2_start_shutdown(net
, ep
, asoc
,
1818 SCTP_ST_CHUNK(0), NULL
,
1821 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
1822 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
1823 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1825 return SCTP_DISPOSITION_CONSUME
;
1828 sctp_chunk_free(repl
);
1830 return SCTP_DISPOSITION_NOMEM
;
1833 /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'B')
1836 * B) In this case, both sides may be attempting to start an association
1837 * at about the same time but the peer endpoint started its INIT
1838 * after responding to the local endpoint's INIT
1840 /* This case represents an initialization collision. */
1841 static sctp_disposition_t
sctp_sf_do_dupcook_b(struct net
*net
,
1842 const struct sctp_endpoint
*ep
,
1843 const struct sctp_association
*asoc
,
1844 struct sctp_chunk
*chunk
,
1845 sctp_cmd_seq_t
*commands
,
1846 struct sctp_association
*new_asoc
)
1848 sctp_init_chunk_t
*peer_init
;
1849 struct sctp_chunk
*repl
;
1851 /* new_asoc is a brand-new association, so these are not yet
1852 * side effects--it is safe to run them here.
1854 peer_init
= &chunk
->subh
.cookie_hdr
->c
.peer_init
[0];
1855 if (!sctp_process_init(new_asoc
, chunk
, sctp_source(chunk
), peer_init
,
1859 /* Update the content of current association. */
1860 sctp_add_cmd_sf(commands
, SCTP_CMD_UPDATE_ASSOC
, SCTP_ASOC(new_asoc
));
1861 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
1862 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
1863 SCTP_INC_STATS(net
, SCTP_MIB_CURRESTAB
);
1864 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_START
, SCTP_NULL());
1866 repl
= sctp_make_cookie_ack(new_asoc
, chunk
);
1870 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1872 /* RFC 2960 5.1 Normal Establishment of an Association
1874 * D) IMPLEMENTATION NOTE: An implementation may choose to
1875 * send the Communication Up notification to the SCTP user
1876 * upon reception of a valid COOKIE ECHO chunk.
1878 * Sadly, this needs to be implemented as a side-effect, because
1879 * we are not guaranteed to have set the association id of the real
1880 * association and so these notifications need to be delayed until
1881 * the association id is allocated.
1884 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_CHANGE
, SCTP_U8(SCTP_COMM_UP
));
1886 /* Sockets API Draft Section 5.3.1.6
1887 * When a peer sends a Adaptation Layer Indication parameter , SCTP
1888 * delivers this notification to inform the application that of the
1889 * peers requested adaptation layer.
1891 * This also needs to be done as a side effect for the same reason as
1894 if (asoc
->peer
.adaptation_ind
)
1895 sctp_add_cmd_sf(commands
, SCTP_CMD_ADAPTATION_IND
, SCTP_NULL());
1897 return SCTP_DISPOSITION_CONSUME
;
1900 return SCTP_DISPOSITION_NOMEM
;
1903 /* Unexpected COOKIE-ECHO handler for setup collision (Table 2, action 'C')
1906 * C) In this case, the local endpoint's cookie has arrived late.
1907 * Before it arrived, the local endpoint sent an INIT and received an
1908 * INIT-ACK and finally sent a COOKIE ECHO with the peer's same tag
1909 * but a new tag of its own.
1911 /* This case represents an initialization collision. */
1912 static sctp_disposition_t
sctp_sf_do_dupcook_c(struct net
*net
,
1913 const struct sctp_endpoint
*ep
,
1914 const struct sctp_association
*asoc
,
1915 struct sctp_chunk
*chunk
,
1916 sctp_cmd_seq_t
*commands
,
1917 struct sctp_association
*new_asoc
)
1919 /* The cookie should be silently discarded.
1920 * The endpoint SHOULD NOT change states and should leave
1921 * any timers running.
1923 return SCTP_DISPOSITION_DISCARD
;
1926 /* Unexpected COOKIE-ECHO handler lost chunk (Table 2, action 'D')
1930 * D) When both local and remote tags match the endpoint should always
1931 * enter the ESTABLISHED state, if it has not already done so.
1933 /* This case represents an initialization collision. */
1934 static sctp_disposition_t
sctp_sf_do_dupcook_d(struct net
*net
,
1935 const struct sctp_endpoint
*ep
,
1936 const struct sctp_association
*asoc
,
1937 struct sctp_chunk
*chunk
,
1938 sctp_cmd_seq_t
*commands
,
1939 struct sctp_association
*new_asoc
)
1941 struct sctp_ulpevent
*ev
= NULL
, *ai_ev
= NULL
;
1942 struct sctp_chunk
*repl
;
1944 /* Clarification from Implementor's Guide:
1945 * D) When both local and remote tags match the endpoint should
1946 * enter the ESTABLISHED state, if it is in the COOKIE-ECHOED state.
1947 * It should stop any cookie timer that may be running and send
1951 /* Don't accidentally move back into established state. */
1952 if (asoc
->state
< SCTP_STATE_ESTABLISHED
) {
1953 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
1954 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
1955 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
1956 SCTP_STATE(SCTP_STATE_ESTABLISHED
));
1957 SCTP_INC_STATS(net
, SCTP_MIB_CURRESTAB
);
1958 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_START
,
1961 /* RFC 2960 5.1 Normal Establishment of an Association
1963 * D) IMPLEMENTATION NOTE: An implementation may choose
1964 * to send the Communication Up notification to the
1965 * SCTP user upon reception of a valid COOKIE
1968 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0,
1970 asoc
->c
.sinit_num_ostreams
,
1971 asoc
->c
.sinit_max_instreams
,
1976 /* Sockets API Draft Section 5.3.1.6
1977 * When a peer sends a Adaptation Layer Indication parameter,
1978 * SCTP delivers this notification to inform the application
1979 * that of the peers requested adaptation layer.
1981 if (asoc
->peer
.adaptation_ind
) {
1982 ai_ev
= sctp_ulpevent_make_adaptation_indication(asoc
,
1990 repl
= sctp_make_cookie_ack(new_asoc
, chunk
);
1994 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
1997 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
2000 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
2001 SCTP_ULPEVENT(ai_ev
));
2003 return SCTP_DISPOSITION_CONSUME
;
2007 sctp_ulpevent_free(ai_ev
);
2009 sctp_ulpevent_free(ev
);
2010 return SCTP_DISPOSITION_NOMEM
;
2014 * Handle a duplicate COOKIE-ECHO. This usually means a cookie-carrying
2015 * chunk was retransmitted and then delayed in the network.
2017 * Section: 5.2.4 Handle a COOKIE ECHO when a TCB exists
2019 * Verification Tag: None. Do cookie validation.
2022 * (endpoint, asoc, chunk)
2025 * (asoc, reply_msg, msg_up, timers, counters)
2027 * The return value is the disposition of the chunk.
2029 sctp_disposition_t
sctp_sf_do_5_2_4_dupcook(struct net
*net
,
2030 const struct sctp_endpoint
*ep
,
2031 const struct sctp_association
*asoc
,
2032 const sctp_subtype_t type
,
2034 sctp_cmd_seq_t
*commands
)
2036 sctp_disposition_t retval
;
2037 struct sctp_chunk
*chunk
= arg
;
2038 struct sctp_association
*new_asoc
;
2041 struct sctp_chunk
*err_chk_p
;
2043 /* Make sure that the chunk has a valid length from the protocol
2044 * perspective. In this case check to make sure we have at least
2045 * enough for the chunk header. Cookie length verification is
2048 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_chunkhdr
)))
2049 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
2052 /* "Decode" the chunk. We have no optional parameters so we
2053 * are in good shape.
2055 chunk
->subh
.cookie_hdr
= (struct sctp_signed_cookie
*)chunk
->skb
->data
;
2056 if (!pskb_pull(chunk
->skb
, ntohs(chunk
->chunk_hdr
->length
) -
2057 sizeof(struct sctp_chunkhdr
)))
2060 /* In RFC 2960 5.2.4 3, if both Verification Tags in the State Cookie
2061 * of a duplicate COOKIE ECHO match the Verification Tags of the
2062 * current association, consider the State Cookie valid even if
2063 * the lifespan is exceeded.
2065 new_asoc
= sctp_unpack_cookie(ep
, asoc
, chunk
, GFP_ATOMIC
, &error
,
2069 * If the re-build failed, what is the proper error path
2072 * [We should abort the association. --piggy]
2075 /* FIXME: Several errors are possible. A bad cookie should
2076 * be silently discarded, but think about logging it too.
2079 case -SCTP_IERROR_NOMEM
:
2082 case -SCTP_IERROR_STALE_COOKIE
:
2083 sctp_send_stale_cookie_err(net
, ep
, asoc
, chunk
, commands
,
2085 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2086 case -SCTP_IERROR_BAD_SIG
:
2088 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2092 /* Set temp so that it won't be added into hashtable */
2095 /* Compare the tie_tag in cookie with the verification tag of
2096 * current association.
2098 action
= sctp_tietags_compare(new_asoc
, asoc
);
2101 case 'A': /* Association restart. */
2102 retval
= sctp_sf_do_dupcook_a(net
, ep
, asoc
, chunk
, commands
,
2106 case 'B': /* Collision case B. */
2107 retval
= sctp_sf_do_dupcook_b(net
, ep
, asoc
, chunk
, commands
,
2111 case 'C': /* Collision case C. */
2112 retval
= sctp_sf_do_dupcook_c(net
, ep
, asoc
, chunk
, commands
,
2116 case 'D': /* Collision case D. */
2117 retval
= sctp_sf_do_dupcook_d(net
, ep
, asoc
, chunk
, commands
,
2121 default: /* Discard packet for all others. */
2122 retval
= sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2126 /* Delete the tempory new association. */
2127 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_ASOC
, SCTP_ASOC(new_asoc
));
2128 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
2130 /* Restore association pointer to provide SCTP command interpeter
2131 * with a valid context in case it needs to manipulate
2133 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_ASOC
,
2134 SCTP_ASOC((struct sctp_association
*)asoc
));
2139 return SCTP_DISPOSITION_NOMEM
;
2143 * Process an ABORT. (SHUTDOWN-PENDING state)
2145 * See sctp_sf_do_9_1_abort().
2147 sctp_disposition_t
sctp_sf_shutdown_pending_abort(
2149 const struct sctp_endpoint
*ep
,
2150 const struct sctp_association
*asoc
,
2151 const sctp_subtype_t type
,
2153 sctp_cmd_seq_t
*commands
)
2155 struct sctp_chunk
*chunk
= arg
;
2157 if (!sctp_vtag_verify_either(chunk
, asoc
))
2158 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2160 /* Make sure that the ABORT chunk has a valid length.
2161 * Since this is an ABORT chunk, we have to discard it
2162 * because of the following text:
2163 * RFC 2960, Section 3.3.7
2164 * If an endpoint receives an ABORT with a format error or for an
2165 * association that doesn't exist, it MUST silently discard it.
2166 * Because the length is "invalid", we can't really discard just
2167 * as we do not know its true length. So, to be safe, discard the
2170 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_abort_chunk_t
)))
2171 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2173 /* ADD-IP: Special case for ABORT chunks
2174 * F4) One special consideration is that ABORT Chunks arriving
2175 * destined to the IP address being deleted MUST be
2176 * ignored (see Section 5.3.1 for further details).
2178 if (SCTP_ADDR_DEL
==
2179 sctp_bind_addr_state(&asoc
->base
.bind_addr
, &chunk
->dest
))
2180 return sctp_sf_discard_chunk(net
, ep
, asoc
, type
, arg
, commands
);
2182 return __sctp_sf_do_9_1_abort(net
, ep
, asoc
, type
, arg
, commands
);
2186 * Process an ABORT. (SHUTDOWN-SENT state)
2188 * See sctp_sf_do_9_1_abort().
2190 sctp_disposition_t
sctp_sf_shutdown_sent_abort(struct net
*net
,
2191 const struct sctp_endpoint
*ep
,
2192 const struct sctp_association
*asoc
,
2193 const sctp_subtype_t type
,
2195 sctp_cmd_seq_t
*commands
)
2197 struct sctp_chunk
*chunk
= arg
;
2199 if (!sctp_vtag_verify_either(chunk
, asoc
))
2200 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2202 /* Make sure that the ABORT chunk has a valid length.
2203 * Since this is an ABORT chunk, we have to discard it
2204 * because of the following text:
2205 * RFC 2960, Section 3.3.7
2206 * If an endpoint receives an ABORT with a format error or for an
2207 * association that doesn't exist, it MUST silently discard it.
2208 * Because the length is "invalid", we can't really discard just
2209 * as we do not know its true length. So, to be safe, discard the
2212 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_abort_chunk_t
)))
2213 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2215 /* ADD-IP: Special case for ABORT chunks
2216 * F4) One special consideration is that ABORT Chunks arriving
2217 * destined to the IP address being deleted MUST be
2218 * ignored (see Section 5.3.1 for further details).
2220 if (SCTP_ADDR_DEL
==
2221 sctp_bind_addr_state(&asoc
->base
.bind_addr
, &chunk
->dest
))
2222 return sctp_sf_discard_chunk(net
, ep
, asoc
, type
, arg
, commands
);
2224 /* Stop the T2-shutdown timer. */
2225 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
2226 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
2228 /* Stop the T5-shutdown guard timer. */
2229 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
2230 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
2232 return __sctp_sf_do_9_1_abort(net
, ep
, asoc
, type
, arg
, commands
);
2236 * Process an ABORT. (SHUTDOWN-ACK-SENT state)
2238 * See sctp_sf_do_9_1_abort().
2240 sctp_disposition_t
sctp_sf_shutdown_ack_sent_abort(
2242 const struct sctp_endpoint
*ep
,
2243 const struct sctp_association
*asoc
,
2244 const sctp_subtype_t type
,
2246 sctp_cmd_seq_t
*commands
)
2248 /* The same T2 timer, so we should be able to use
2249 * common function with the SHUTDOWN-SENT state.
2251 return sctp_sf_shutdown_sent_abort(net
, ep
, asoc
, type
, arg
, commands
);
2255 * Handle an Error received in COOKIE_ECHOED state.
2257 * Only handle the error type of stale COOKIE Error, the other errors will
2261 * (endpoint, asoc, chunk)
2264 * (asoc, reply_msg, msg_up, timers, counters)
2266 * The return value is the disposition of the chunk.
2268 sctp_disposition_t
sctp_sf_cookie_echoed_err(struct net
*net
,
2269 const struct sctp_endpoint
*ep
,
2270 const struct sctp_association
*asoc
,
2271 const sctp_subtype_t type
,
2273 sctp_cmd_seq_t
*commands
)
2275 struct sctp_chunk
*chunk
= arg
;
2278 if (!sctp_vtag_verify(chunk
, asoc
))
2279 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2281 /* Make sure that the ERROR chunk has a valid length.
2282 * The parameter walking depends on this as well.
2284 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_operr_chunk_t
)))
2285 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
2288 /* Process the error here */
2289 /* FUTURE FIXME: When PR-SCTP related and other optional
2290 * parms are emitted, this will have to change to handle multiple
2293 sctp_walk_errors(err
, chunk
->chunk_hdr
) {
2294 if (SCTP_ERROR_STALE_COOKIE
== err
->cause
)
2295 return sctp_sf_do_5_2_6_stale(net
, ep
, asoc
, type
,
2299 /* It is possible to have malformed error causes, and that
2300 * will cause us to end the walk early. However, since
2301 * we are discarding the packet, there should be no adverse
2304 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2308 * Handle a Stale COOKIE Error
2310 * Section: 5.2.6 Handle Stale COOKIE Error
2311 * If the association is in the COOKIE-ECHOED state, the endpoint may elect
2312 * one of the following three alternatives.
2314 * 3) Send a new INIT chunk to the endpoint, adding a Cookie
2315 * Preservative parameter requesting an extension to the lifetime of
2316 * the State Cookie. When calculating the time extension, an
2317 * implementation SHOULD use the RTT information measured based on the
2318 * previous COOKIE ECHO / ERROR exchange, and should add no more
2319 * than 1 second beyond the measured RTT, due to long State Cookie
2320 * lifetimes making the endpoint more subject to a replay attack.
2322 * Verification Tag: Not explicit, but safe to ignore.
2325 * (endpoint, asoc, chunk)
2328 * (asoc, reply_msg, msg_up, timers, counters)
2330 * The return value is the disposition of the chunk.
2332 static sctp_disposition_t
sctp_sf_do_5_2_6_stale(struct net
*net
,
2333 const struct sctp_endpoint
*ep
,
2334 const struct sctp_association
*asoc
,
2335 const sctp_subtype_t type
,
2337 sctp_cmd_seq_t
*commands
)
2339 struct sctp_chunk
*chunk
= arg
;
2341 sctp_cookie_preserve_param_t bht
;
2343 struct sctp_chunk
*reply
;
2344 struct sctp_bind_addr
*bp
;
2345 int attempts
= asoc
->init_err_counter
+ 1;
2347 if (attempts
> asoc
->max_init_attempts
) {
2348 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
2349 SCTP_ERROR(ETIMEDOUT
));
2350 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
2351 SCTP_PERR(SCTP_ERROR_STALE_COOKIE
));
2352 return SCTP_DISPOSITION_DELETE_TCB
;
2355 err
= (sctp_errhdr_t
*)(chunk
->skb
->data
);
2357 /* When calculating the time extension, an implementation
2358 * SHOULD use the RTT information measured based on the
2359 * previous COOKIE ECHO / ERROR exchange, and should add no
2360 * more than 1 second beyond the measured RTT, due to long
2361 * State Cookie lifetimes making the endpoint more subject to
2363 * Measure of Staleness's unit is usec. (1/1000000 sec)
2364 * Suggested Cookie Life-span Increment's unit is msec.
2366 * In general, if you use the suggested cookie life, the value
2367 * found in the field of measure of staleness should be doubled
2368 * to give ample time to retransmit the new cookie and thus
2369 * yield a higher probability of success on the reattempt.
2371 stale
= ntohl(*(__be32
*)((u8
*)err
+ sizeof(sctp_errhdr_t
)));
2372 stale
= (stale
* 2) / 1000;
2374 bht
.param_hdr
.type
= SCTP_PARAM_COOKIE_PRESERVATIVE
;
2375 bht
.param_hdr
.length
= htons(sizeof(bht
));
2376 bht
.lifespan_increment
= htonl(stale
);
2378 /* Build that new INIT chunk. */
2379 bp
= (struct sctp_bind_addr
*) &asoc
->base
.bind_addr
;
2380 reply
= sctp_make_init(asoc
, bp
, GFP_ATOMIC
, sizeof(bht
));
2384 sctp_addto_chunk(reply
, sizeof(bht
), &bht
);
2386 /* Clear peer's init_tag cached in assoc as we are sending a new INIT */
2387 sctp_add_cmd_sf(commands
, SCTP_CMD_CLEAR_INIT_TAG
, SCTP_NULL());
2389 /* Stop pending T3-rtx and heartbeat timers */
2390 sctp_add_cmd_sf(commands
, SCTP_CMD_T3_RTX_TIMERS_STOP
, SCTP_NULL());
2391 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_STOP
, SCTP_NULL());
2393 /* Delete non-primary peer ip addresses since we are transitioning
2394 * back to the COOKIE-WAIT state
2396 sctp_add_cmd_sf(commands
, SCTP_CMD_DEL_NON_PRIMARY
, SCTP_NULL());
2398 /* If we've sent any data bundled with COOKIE-ECHO we will need to
2401 sctp_add_cmd_sf(commands
, SCTP_CMD_T1_RETRAN
,
2402 SCTP_TRANSPORT(asoc
->peer
.primary_path
));
2404 /* Cast away the const modifier, as we want to just
2405 * rerun it through as a sideffect.
2407 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_COUNTER_INC
, SCTP_NULL());
2409 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
2410 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
2411 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
2412 SCTP_STATE(SCTP_STATE_COOKIE_WAIT
));
2413 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
2414 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
2416 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
2418 return SCTP_DISPOSITION_CONSUME
;
2421 return SCTP_DISPOSITION_NOMEM
;
2428 * After checking the Verification Tag, the receiving endpoint shall
2429 * remove the association from its record, and shall report the
2430 * termination to its upper layer.
2432 * Verification Tag: 8.5.1 Exceptions in Verification Tag Rules
2433 * B) Rules for packet carrying ABORT:
2435 * - The endpoint shall always fill in the Verification Tag field of the
2436 * outbound packet with the destination endpoint's tag value if it
2439 * - If the ABORT is sent in response to an OOTB packet, the endpoint
2440 * MUST follow the procedure described in Section 8.4.
2442 * - The receiver MUST accept the packet if the Verification Tag
2443 * matches either its own tag, OR the tag of its peer. Otherwise, the
2444 * receiver MUST silently discard the packet and take no further
2448 * (endpoint, asoc, chunk)
2451 * (asoc, reply_msg, msg_up, timers, counters)
2453 * The return value is the disposition of the chunk.
2455 sctp_disposition_t
sctp_sf_do_9_1_abort(struct net
*net
,
2456 const struct sctp_endpoint
*ep
,
2457 const struct sctp_association
*asoc
,
2458 const sctp_subtype_t type
,
2460 sctp_cmd_seq_t
*commands
)
2462 struct sctp_chunk
*chunk
= arg
;
2464 if (!sctp_vtag_verify_either(chunk
, asoc
))
2465 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2467 /* Make sure that the ABORT chunk has a valid length.
2468 * Since this is an ABORT chunk, we have to discard it
2469 * because of the following text:
2470 * RFC 2960, Section 3.3.7
2471 * If an endpoint receives an ABORT with a format error or for an
2472 * association that doesn't exist, it MUST silently discard it.
2473 * Because the length is "invalid", we can't really discard just
2474 * as we do not know its true length. So, to be safe, discard the
2477 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_abort_chunk_t
)))
2478 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2480 /* ADD-IP: Special case for ABORT chunks
2481 * F4) One special consideration is that ABORT Chunks arriving
2482 * destined to the IP address being deleted MUST be
2483 * ignored (see Section 5.3.1 for further details).
2485 if (SCTP_ADDR_DEL
==
2486 sctp_bind_addr_state(&asoc
->base
.bind_addr
, &chunk
->dest
))
2487 return sctp_sf_discard_chunk(net
, ep
, asoc
, type
, arg
, commands
);
2489 return __sctp_sf_do_9_1_abort(net
, ep
, asoc
, type
, arg
, commands
);
2492 static sctp_disposition_t
__sctp_sf_do_9_1_abort(struct net
*net
,
2493 const struct sctp_endpoint
*ep
,
2494 const struct sctp_association
*asoc
,
2495 const sctp_subtype_t type
,
2497 sctp_cmd_seq_t
*commands
)
2499 struct sctp_chunk
*chunk
= arg
;
2501 __be16 error
= SCTP_ERROR_NO_ERROR
;
2503 /* See if we have an error cause code in the chunk. */
2504 len
= ntohs(chunk
->chunk_hdr
->length
);
2505 if (len
>= sizeof(struct sctp_chunkhdr
) + sizeof(struct sctp_errhdr
)) {
2508 sctp_walk_errors(err
, chunk
->chunk_hdr
);
2509 if ((void *)err
!= (void *)chunk
->chunk_end
)
2510 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2512 error
= ((sctp_errhdr_t
*)chunk
->skb
->data
)->cause
;
2515 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
, SCTP_ERROR(ECONNRESET
));
2516 /* ASSOC_FAILED will DELETE_TCB. */
2517 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
, SCTP_PERR(error
));
2518 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
2519 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
2521 return SCTP_DISPOSITION_ABORT
;
2525 * Process an ABORT. (COOKIE-WAIT state)
2527 * See sctp_sf_do_9_1_abort() above.
2529 sctp_disposition_t
sctp_sf_cookie_wait_abort(struct net
*net
,
2530 const struct sctp_endpoint
*ep
,
2531 const struct sctp_association
*asoc
,
2532 const sctp_subtype_t type
,
2534 sctp_cmd_seq_t
*commands
)
2536 struct sctp_chunk
*chunk
= arg
;
2538 __be16 error
= SCTP_ERROR_NO_ERROR
;
2540 if (!sctp_vtag_verify_either(chunk
, asoc
))
2541 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2543 /* Make sure that the ABORT chunk has a valid length.
2544 * Since this is an ABORT chunk, we have to discard it
2545 * because of the following text:
2546 * RFC 2960, Section 3.3.7
2547 * If an endpoint receives an ABORT with a format error or for an
2548 * association that doesn't exist, it MUST silently discard it.
2549 * Because the length is "invalid", we can't really discard just
2550 * as we do not know its true length. So, to be safe, discard the
2553 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_abort_chunk_t
)))
2554 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2556 /* See if we have an error cause code in the chunk. */
2557 len
= ntohs(chunk
->chunk_hdr
->length
);
2558 if (len
>= sizeof(struct sctp_chunkhdr
) + sizeof(struct sctp_errhdr
))
2559 error
= ((sctp_errhdr_t
*)chunk
->skb
->data
)->cause
;
2561 return sctp_stop_t1_and_abort(net
, commands
, error
, ECONNREFUSED
, asoc
,
2566 * Process an incoming ICMP as an ABORT. (COOKIE-WAIT state)
2568 sctp_disposition_t
sctp_sf_cookie_wait_icmp_abort(struct net
*net
,
2569 const struct sctp_endpoint
*ep
,
2570 const struct sctp_association
*asoc
,
2571 const sctp_subtype_t type
,
2573 sctp_cmd_seq_t
*commands
)
2575 return sctp_stop_t1_and_abort(net
, commands
, SCTP_ERROR_NO_ERROR
,
2577 (struct sctp_transport
*)arg
);
2581 * Process an ABORT. (COOKIE-ECHOED state)
2583 sctp_disposition_t
sctp_sf_cookie_echoed_abort(struct net
*net
,
2584 const struct sctp_endpoint
*ep
,
2585 const struct sctp_association
*asoc
,
2586 const sctp_subtype_t type
,
2588 sctp_cmd_seq_t
*commands
)
2590 /* There is a single T1 timer, so we should be able to use
2591 * common function with the COOKIE-WAIT state.
2593 return sctp_sf_cookie_wait_abort(net
, ep
, asoc
, type
, arg
, commands
);
2597 * Stop T1 timer and abort association with "INIT failed".
2599 * This is common code called by several sctp_sf_*_abort() functions above.
2601 static sctp_disposition_t
sctp_stop_t1_and_abort(struct net
*net
,
2602 sctp_cmd_seq_t
*commands
,
2603 __be16 error
, int sk_err
,
2604 const struct sctp_association
*asoc
,
2605 struct sctp_transport
*transport
)
2607 pr_debug("%s: ABORT received (INIT)\n", __func__
);
2609 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
2610 SCTP_STATE(SCTP_STATE_CLOSED
));
2611 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
2612 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
2613 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
2614 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
, SCTP_ERROR(sk_err
));
2615 /* CMD_INIT_FAILED will DELETE_TCB. */
2616 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
2619 return SCTP_DISPOSITION_ABORT
;
2623 * sctp_sf_do_9_2_shut
2626 * Upon the reception of the SHUTDOWN, the peer endpoint shall
2627 * - enter the SHUTDOWN-RECEIVED state,
2629 * - stop accepting new data from its SCTP user
2631 * - verify, by checking the Cumulative TSN Ack field of the chunk,
2632 * that all its outstanding DATA chunks have been received by the
2635 * Once an endpoint as reached the SHUTDOWN-RECEIVED state it MUST NOT
2636 * send a SHUTDOWN in response to a ULP request. And should discard
2637 * subsequent SHUTDOWN chunks.
2639 * If there are still outstanding DATA chunks left, the SHUTDOWN
2640 * receiver shall continue to follow normal data transmission
2641 * procedures defined in Section 6 until all outstanding DATA chunks
2642 * are acknowledged; however, the SHUTDOWN receiver MUST NOT accept
2643 * new data from its SCTP user.
2645 * Verification Tag: 8.5 Verification Tag [Normal verification]
2648 * (endpoint, asoc, chunk)
2651 * (asoc, reply_msg, msg_up, timers, counters)
2653 * The return value is the disposition of the chunk.
2655 sctp_disposition_t
sctp_sf_do_9_2_shutdown(struct net
*net
,
2656 const struct sctp_endpoint
*ep
,
2657 const struct sctp_association
*asoc
,
2658 const sctp_subtype_t type
,
2660 sctp_cmd_seq_t
*commands
)
2662 struct sctp_chunk
*chunk
= arg
;
2663 sctp_shutdownhdr_t
*sdh
;
2664 sctp_disposition_t disposition
;
2665 struct sctp_ulpevent
*ev
;
2668 if (!sctp_vtag_verify(chunk
, asoc
))
2669 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2671 /* Make sure that the SHUTDOWN chunk has a valid length. */
2672 if (!sctp_chunk_length_valid(chunk
,
2673 sizeof(struct sctp_shutdown_chunk_t
)))
2674 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
2677 /* Convert the elaborate header. */
2678 sdh
= (sctp_shutdownhdr_t
*)chunk
->skb
->data
;
2679 skb_pull(chunk
->skb
, sizeof(sctp_shutdownhdr_t
));
2680 chunk
->subh
.shutdown_hdr
= sdh
;
2681 ctsn
= ntohl(sdh
->cum_tsn_ack
);
2683 if (TSN_lt(ctsn
, asoc
->ctsn_ack_point
)) {
2684 pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__
, ctsn
,
2685 asoc
->ctsn_ack_point
);
2687 return SCTP_DISPOSITION_DISCARD
;
2690 /* If Cumulative TSN Ack beyond the max tsn currently
2691 * send, terminating the association and respond to the
2692 * sender with an ABORT.
2694 if (!TSN_lt(ctsn
, asoc
->next_tsn
))
2695 return sctp_sf_violation_ctsn(net
, ep
, asoc
, type
, arg
, commands
);
2697 /* API 5.3.1.5 SCTP_SHUTDOWN_EVENT
2698 * When a peer sends a SHUTDOWN, SCTP delivers this notification to
2699 * inform the application that it should cease sending data.
2701 ev
= sctp_ulpevent_make_shutdown_event(asoc
, 0, GFP_ATOMIC
);
2703 disposition
= SCTP_DISPOSITION_NOMEM
;
2706 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
2708 /* Upon the reception of the SHUTDOWN, the peer endpoint shall
2709 * - enter the SHUTDOWN-RECEIVED state,
2710 * - stop accepting new data from its SCTP user
2712 * [This is implicit in the new state.]
2714 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
2715 SCTP_STATE(SCTP_STATE_SHUTDOWN_RECEIVED
));
2716 disposition
= SCTP_DISPOSITION_CONSUME
;
2718 if (sctp_outq_is_empty(&asoc
->outqueue
)) {
2719 disposition
= sctp_sf_do_9_2_shutdown_ack(net
, ep
, asoc
, type
,
2723 if (SCTP_DISPOSITION_NOMEM
== disposition
)
2726 /* - verify, by checking the Cumulative TSN Ack field of the
2727 * chunk, that all its outstanding DATA chunks have been
2728 * received by the SHUTDOWN sender.
2730 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_CTSN
,
2731 SCTP_BE32(chunk
->subh
.shutdown_hdr
->cum_tsn_ack
));
2738 * sctp_sf_do_9_2_shut_ctsn
2740 * Once an endpoint has reached the SHUTDOWN-RECEIVED state,
2741 * it MUST NOT send a SHUTDOWN in response to a ULP request.
2742 * The Cumulative TSN Ack of the received SHUTDOWN chunk
2743 * MUST be processed.
2745 sctp_disposition_t
sctp_sf_do_9_2_shut_ctsn(struct net
*net
,
2746 const struct sctp_endpoint
*ep
,
2747 const struct sctp_association
*asoc
,
2748 const sctp_subtype_t type
,
2750 sctp_cmd_seq_t
*commands
)
2752 struct sctp_chunk
*chunk
= arg
;
2753 sctp_shutdownhdr_t
*sdh
;
2756 if (!sctp_vtag_verify(chunk
, asoc
))
2757 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2759 /* Make sure that the SHUTDOWN chunk has a valid length. */
2760 if (!sctp_chunk_length_valid(chunk
,
2761 sizeof(struct sctp_shutdown_chunk_t
)))
2762 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
2765 sdh
= (sctp_shutdownhdr_t
*)chunk
->skb
->data
;
2766 ctsn
= ntohl(sdh
->cum_tsn_ack
);
2768 if (TSN_lt(ctsn
, asoc
->ctsn_ack_point
)) {
2769 pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__
, ctsn
,
2770 asoc
->ctsn_ack_point
);
2772 return SCTP_DISPOSITION_DISCARD
;
2775 /* If Cumulative TSN Ack beyond the max tsn currently
2776 * send, terminating the association and respond to the
2777 * sender with an ABORT.
2779 if (!TSN_lt(ctsn
, asoc
->next_tsn
))
2780 return sctp_sf_violation_ctsn(net
, ep
, asoc
, type
, arg
, commands
);
2782 /* verify, by checking the Cumulative TSN Ack field of the
2783 * chunk, that all its outstanding DATA chunks have been
2784 * received by the SHUTDOWN sender.
2786 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_CTSN
,
2787 SCTP_BE32(sdh
->cum_tsn_ack
));
2789 return SCTP_DISPOSITION_CONSUME
;
2793 * If an endpoint is in SHUTDOWN-ACK-SENT state and receives an INIT chunk
2794 * (e.g., if the SHUTDOWN COMPLETE was lost) with source and destination
2795 * transport addresses (either in the IP addresses or in the INIT chunk)
2796 * that belong to this association, it should discard the INIT chunk and
2797 * retransmit the SHUTDOWN ACK chunk.
2799 sctp_disposition_t
sctp_sf_do_9_2_reshutack(struct net
*net
,
2800 const struct sctp_endpoint
*ep
,
2801 const struct sctp_association
*asoc
,
2802 const sctp_subtype_t type
,
2804 sctp_cmd_seq_t
*commands
)
2806 struct sctp_chunk
*chunk
= (struct sctp_chunk
*) arg
;
2807 struct sctp_chunk
*reply
;
2809 /* Make sure that the chunk has a valid length */
2810 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_chunkhdr
)))
2811 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
2814 /* Since we are not going to really process this INIT, there
2815 * is no point in verifying chunk boundries. Just generate
2818 reply
= sctp_make_shutdown_ack(asoc
, chunk
);
2822 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
2823 * the T2-SHUTDOWN timer.
2825 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T2
, SCTP_CHUNK(reply
));
2827 /* and restart the T2-shutdown timer. */
2828 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
2829 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
2831 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
2833 return SCTP_DISPOSITION_CONSUME
;
2835 return SCTP_DISPOSITION_NOMEM
;
2839 * sctp_sf_do_ecn_cwr
2841 * Section: Appendix A: Explicit Congestion Notification
2845 * RFC 2481 details a specific bit for a sender to send in the header of
2846 * its next outbound TCP segment to indicate to its peer that it has
2847 * reduced its congestion window. This is termed the CWR bit. For
2848 * SCTP the same indication is made by including the CWR chunk.
2849 * This chunk contains one data element, i.e. the TSN number that
2850 * was sent in the ECNE chunk. This element represents the lowest
2851 * TSN number in the datagram that was originally marked with the
2854 * Verification Tag: 8.5 Verification Tag [Normal verification]
2856 * (endpoint, asoc, chunk)
2859 * (asoc, reply_msg, msg_up, timers, counters)
2861 * The return value is the disposition of the chunk.
2863 sctp_disposition_t
sctp_sf_do_ecn_cwr(struct net
*net
,
2864 const struct sctp_endpoint
*ep
,
2865 const struct sctp_association
*asoc
,
2866 const sctp_subtype_t type
,
2868 sctp_cmd_seq_t
*commands
)
2871 struct sctp_chunk
*chunk
= arg
;
2874 if (!sctp_vtag_verify(chunk
, asoc
))
2875 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2877 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_ecne_chunk_t
)))
2878 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
2881 cwr
= (sctp_cwrhdr_t
*) chunk
->skb
->data
;
2882 skb_pull(chunk
->skb
, sizeof(sctp_cwrhdr_t
));
2884 lowest_tsn
= ntohl(cwr
->lowest_tsn
);
2886 /* Does this CWR ack the last sent congestion notification? */
2887 if (TSN_lte(asoc
->last_ecne_tsn
, lowest_tsn
)) {
2888 /* Stop sending ECNE. */
2889 sctp_add_cmd_sf(commands
,
2891 SCTP_U32(lowest_tsn
));
2893 return SCTP_DISPOSITION_CONSUME
;
2899 * Section: Appendix A: Explicit Congestion Notification
2903 * RFC 2481 details a specific bit for a receiver to send back in its
2904 * TCP acknowledgements to notify the sender of the Congestion
2905 * Experienced (CE) bit having arrived from the network. For SCTP this
2906 * same indication is made by including the ECNE chunk. This chunk
2907 * contains one data element, i.e. the lowest TSN associated with the IP
2908 * datagram marked with the CE bit.....
2910 * Verification Tag: 8.5 Verification Tag [Normal verification]
2912 * (endpoint, asoc, chunk)
2915 * (asoc, reply_msg, msg_up, timers, counters)
2917 * The return value is the disposition of the chunk.
2919 sctp_disposition_t
sctp_sf_do_ecne(struct net
*net
,
2920 const struct sctp_endpoint
*ep
,
2921 const struct sctp_association
*asoc
,
2922 const sctp_subtype_t type
,
2924 sctp_cmd_seq_t
*commands
)
2926 sctp_ecnehdr_t
*ecne
;
2927 struct sctp_chunk
*chunk
= arg
;
2929 if (!sctp_vtag_verify(chunk
, asoc
))
2930 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2932 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_ecne_chunk_t
)))
2933 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
2936 ecne
= (sctp_ecnehdr_t
*) chunk
->skb
->data
;
2937 skb_pull(chunk
->skb
, sizeof(sctp_ecnehdr_t
));
2939 /* If this is a newer ECNE than the last CWR packet we sent out */
2940 sctp_add_cmd_sf(commands
, SCTP_CMD_ECN_ECNE
,
2941 SCTP_U32(ntohl(ecne
->lowest_tsn
)));
2943 return SCTP_DISPOSITION_CONSUME
;
2947 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
2949 * The SCTP endpoint MUST always acknowledge the reception of each valid
2952 * The guidelines on delayed acknowledgement algorithm specified in
2953 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
2954 * acknowledgement SHOULD be generated for at least every second packet
2955 * (not every second DATA chunk) received, and SHOULD be generated within
2956 * 200 ms of the arrival of any unacknowledged DATA chunk. In some
2957 * situations it may be beneficial for an SCTP transmitter to be more
2958 * conservative than the algorithms detailed in this document allow.
2959 * However, an SCTP transmitter MUST NOT be more aggressive than the
2960 * following algorithms allow.
2962 * A SCTP receiver MUST NOT generate more than one SACK for every
2963 * incoming packet, other than to update the offered window as the
2964 * receiving application consumes new data.
2966 * Verification Tag: 8.5 Verification Tag [Normal verification]
2969 * (endpoint, asoc, chunk)
2972 * (asoc, reply_msg, msg_up, timers, counters)
2974 * The return value is the disposition of the chunk.
2976 sctp_disposition_t
sctp_sf_eat_data_6_2(struct net
*net
,
2977 const struct sctp_endpoint
*ep
,
2978 const struct sctp_association
*asoc
,
2979 const sctp_subtype_t type
,
2981 sctp_cmd_seq_t
*commands
)
2983 struct sctp_chunk
*chunk
= arg
;
2984 sctp_arg_t force
= SCTP_NOFORCE();
2987 if (!sctp_vtag_verify(chunk
, asoc
)) {
2988 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
2990 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
2993 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_data_chunk_t
)))
2994 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
2997 error
= sctp_eat_data(asoc
, chunk
, commands
);
2999 case SCTP_IERROR_NO_ERROR
:
3001 case SCTP_IERROR_HIGH_TSN
:
3002 case SCTP_IERROR_BAD_STREAM
:
3003 SCTP_INC_STATS(net
, SCTP_MIB_IN_DATA_CHUNK_DISCARDS
);
3004 goto discard_noforce
;
3005 case SCTP_IERROR_DUP_TSN
:
3006 case SCTP_IERROR_IGNORE_TSN
:
3007 SCTP_INC_STATS(net
, SCTP_MIB_IN_DATA_CHUNK_DISCARDS
);
3009 case SCTP_IERROR_NO_DATA
:
3010 return SCTP_DISPOSITION_ABORT
;
3011 case SCTP_IERROR_PROTO_VIOLATION
:
3012 return sctp_sf_abort_violation(net
, ep
, asoc
, chunk
, commands
,
3013 (u8
*)chunk
->subh
.data_hdr
, sizeof(sctp_datahdr_t
));
3018 if (chunk
->chunk_hdr
->flags
& SCTP_DATA_SACK_IMM
)
3019 force
= SCTP_FORCE();
3021 if (asoc
->timeouts
[SCTP_EVENT_TIMEOUT_AUTOCLOSE
]) {
3022 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
3023 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
3026 /* If this is the last chunk in a packet, we need to count it
3027 * toward sack generation. Note that we need to SACK every
3028 * OTHER packet containing data chunks, EVEN IF WE DISCARD
3029 * THEM. We elect to NOT generate SACK's if the chunk fails
3030 * the verification tag test.
3032 * RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
3034 * The SCTP endpoint MUST always acknowledge the reception of
3035 * each valid DATA chunk.
3037 * The guidelines on delayed acknowledgement algorithm
3038 * specified in Section 4.2 of [RFC2581] SHOULD be followed.
3039 * Specifically, an acknowledgement SHOULD be generated for at
3040 * least every second packet (not every second DATA chunk)
3041 * received, and SHOULD be generated within 200 ms of the
3042 * arrival of any unacknowledged DATA chunk. In some
3043 * situations it may be beneficial for an SCTP transmitter to
3044 * be more conservative than the algorithms detailed in this
3045 * document allow. However, an SCTP transmitter MUST NOT be
3046 * more aggressive than the following algorithms allow.
3048 if (chunk
->end_of_packet
)
3049 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, force
);
3051 return SCTP_DISPOSITION_CONSUME
;
3054 /* RFC 2960 6.2 Acknowledgement on Reception of DATA Chunks
3056 * When a packet arrives with duplicate DATA chunk(s) and with
3057 * no new DATA chunk(s), the endpoint MUST immediately send a
3058 * SACK with no delay. If a packet arrives with duplicate
3059 * DATA chunk(s) bundled with new DATA chunks, the endpoint
3060 * MAY immediately send a SACK. Normally receipt of duplicate
3061 * DATA chunks will occur when the original SACK chunk was lost
3062 * and the peer's RTO has expired. The duplicate TSN number(s)
3063 * SHOULD be reported in the SACK as duplicate.
3065 /* In our case, we split the MAY SACK advice up whether or not
3066 * the last chunk is a duplicate.'
3068 if (chunk
->end_of_packet
)
3069 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_FORCE());
3070 return SCTP_DISPOSITION_DISCARD
;
3073 if (chunk
->end_of_packet
)
3074 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, force
);
3076 return SCTP_DISPOSITION_DISCARD
;
3080 * sctp_sf_eat_data_fast_4_4
3083 * (4) In SHUTDOWN-SENT state the endpoint MUST acknowledge any received
3084 * DATA chunks without delay.
3086 * Verification Tag: 8.5 Verification Tag [Normal verification]
3088 * (endpoint, asoc, chunk)
3091 * (asoc, reply_msg, msg_up, timers, counters)
3093 * The return value is the disposition of the chunk.
3095 sctp_disposition_t
sctp_sf_eat_data_fast_4_4(struct net
*net
,
3096 const struct sctp_endpoint
*ep
,
3097 const struct sctp_association
*asoc
,
3098 const sctp_subtype_t type
,
3100 sctp_cmd_seq_t
*commands
)
3102 struct sctp_chunk
*chunk
= arg
;
3105 if (!sctp_vtag_verify(chunk
, asoc
)) {
3106 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3108 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3111 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_data_chunk_t
)))
3112 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
3115 error
= sctp_eat_data(asoc
, chunk
, commands
);
3117 case SCTP_IERROR_NO_ERROR
:
3118 case SCTP_IERROR_HIGH_TSN
:
3119 case SCTP_IERROR_DUP_TSN
:
3120 case SCTP_IERROR_IGNORE_TSN
:
3121 case SCTP_IERROR_BAD_STREAM
:
3123 case SCTP_IERROR_NO_DATA
:
3124 return SCTP_DISPOSITION_ABORT
;
3125 case SCTP_IERROR_PROTO_VIOLATION
:
3126 return sctp_sf_abort_violation(net
, ep
, asoc
, chunk
, commands
,
3127 (u8
*)chunk
->subh
.data_hdr
, sizeof(sctp_datahdr_t
));
3132 /* Go a head and force a SACK, since we are shutting down. */
3134 /* Implementor's Guide.
3136 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
3137 * respond to each received packet containing one or more DATA chunk(s)
3138 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
3140 if (chunk
->end_of_packet
) {
3141 /* We must delay the chunk creation since the cumulative
3142 * TSN has not been updated yet.
3144 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SHUTDOWN
, SCTP_NULL());
3145 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_FORCE());
3146 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
3147 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
3150 return SCTP_DISPOSITION_CONSUME
;
3154 * Section: 6.2 Processing a Received SACK
3155 * D) Any time a SACK arrives, the endpoint performs the following:
3157 * i) If Cumulative TSN Ack is less than the Cumulative TSN Ack Point,
3158 * then drop the SACK. Since Cumulative TSN Ack is monotonically
3159 * increasing, a SACK whose Cumulative TSN Ack is less than the
3160 * Cumulative TSN Ack Point indicates an out-of-order SACK.
3162 * ii) Set rwnd equal to the newly received a_rwnd minus the number
3163 * of bytes still outstanding after processing the Cumulative TSN Ack
3164 * and the Gap Ack Blocks.
3166 * iii) If the SACK is missing a TSN that was previously
3167 * acknowledged via a Gap Ack Block (e.g., the data receiver
3168 * reneged on the data), then mark the corresponding DATA chunk
3169 * as available for retransmit: Mark it as missing for fast
3170 * retransmit as described in Section 7.2.4 and if no retransmit
3171 * timer is running for the destination address to which the DATA
3172 * chunk was originally transmitted, then T3-rtx is started for
3173 * that destination address.
3175 * Verification Tag: 8.5 Verification Tag [Normal verification]
3178 * (endpoint, asoc, chunk)
3181 * (asoc, reply_msg, msg_up, timers, counters)
3183 * The return value is the disposition of the chunk.
3185 sctp_disposition_t
sctp_sf_eat_sack_6_2(struct net
*net
,
3186 const struct sctp_endpoint
*ep
,
3187 const struct sctp_association
*asoc
,
3188 const sctp_subtype_t type
,
3190 sctp_cmd_seq_t
*commands
)
3192 struct sctp_chunk
*chunk
= arg
;
3193 sctp_sackhdr_t
*sackh
;
3196 if (!sctp_vtag_verify(chunk
, asoc
))
3197 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3199 /* Make sure that the SACK chunk has a valid length. */
3200 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_sack_chunk_t
)))
3201 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
3204 /* Pull the SACK chunk from the data buffer */
3205 sackh
= sctp_sm_pull_sack(chunk
);
3206 /* Was this a bogus SACK? */
3208 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3209 chunk
->subh
.sack_hdr
= sackh
;
3210 ctsn
= ntohl(sackh
->cum_tsn_ack
);
3212 /* i) If Cumulative TSN Ack is less than the Cumulative TSN
3213 * Ack Point, then drop the SACK. Since Cumulative TSN
3214 * Ack is monotonically increasing, a SACK whose
3215 * Cumulative TSN Ack is less than the Cumulative TSN Ack
3216 * Point indicates an out-of-order SACK.
3218 if (TSN_lt(ctsn
, asoc
->ctsn_ack_point
)) {
3219 pr_debug("%s: ctsn:%x, ctsn_ack_point:%x\n", __func__
, ctsn
,
3220 asoc
->ctsn_ack_point
);
3222 return SCTP_DISPOSITION_DISCARD
;
3225 /* If Cumulative TSN Ack beyond the max tsn currently
3226 * send, terminating the association and respond to the
3227 * sender with an ABORT.
3229 if (!TSN_lt(ctsn
, asoc
->next_tsn
))
3230 return sctp_sf_violation_ctsn(net
, ep
, asoc
, type
, arg
, commands
);
3232 /* Return this SACK for further processing. */
3233 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_SACK
, SCTP_CHUNK(chunk
));
3235 /* Note: We do the rest of the work on the PROCESS_SACK
3238 return SCTP_DISPOSITION_CONSUME
;
3242 * Generate an ABORT in response to a packet.
3244 * Section: 8.4 Handle "Out of the blue" Packets, sctpimpguide 2.41
3246 * 8) The receiver should respond to the sender of the OOTB packet with
3247 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3248 * MUST fill in the Verification Tag field of the outbound packet
3249 * with the value found in the Verification Tag field of the OOTB
3250 * packet and set the T-bit in the Chunk Flags to indicate that the
3251 * Verification Tag is reflected. After sending this ABORT, the
3252 * receiver of the OOTB packet shall discard the OOTB packet and take
3253 * no further action.
3257 * The return value is the disposition of the chunk.
3259 static sctp_disposition_t
sctp_sf_tabort_8_4_8(struct net
*net
,
3260 const struct sctp_endpoint
*ep
,
3261 const struct sctp_association
*asoc
,
3262 const sctp_subtype_t type
,
3264 sctp_cmd_seq_t
*commands
)
3266 struct sctp_packet
*packet
= NULL
;
3267 struct sctp_chunk
*chunk
= arg
;
3268 struct sctp_chunk
*abort
;
3270 packet
= sctp_ootb_pkt_new(net
, asoc
, chunk
);
3272 return SCTP_DISPOSITION_NOMEM
;
3274 /* Make an ABORT. The T bit will be set if the asoc
3277 abort
= sctp_make_abort(asoc
, chunk
, 0);
3279 sctp_ootb_pkt_free(packet
);
3280 return SCTP_DISPOSITION_NOMEM
;
3283 /* Reflect vtag if T-Bit is set */
3284 if (sctp_test_T_bit(abort
))
3285 packet
->vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
3287 /* Set the skb to the belonging sock for accounting. */
3288 abort
->skb
->sk
= ep
->base
.sk
;
3290 sctp_packet_append_chunk(packet
, abort
);
3292 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
3293 SCTP_PACKET(packet
));
3295 SCTP_INC_STATS(net
, SCTP_MIB_OUTCTRLCHUNKS
);
3297 sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3298 return SCTP_DISPOSITION_CONSUME
;
3302 * Received an ERROR chunk from peer. Generate SCTP_REMOTE_ERROR
3303 * event as ULP notification for each cause included in the chunk.
3305 * API 5.3.1.3 - SCTP_REMOTE_ERROR
3307 * The return value is the disposition of the chunk.
3309 sctp_disposition_t
sctp_sf_operr_notify(struct net
*net
,
3310 const struct sctp_endpoint
*ep
,
3311 const struct sctp_association
*asoc
,
3312 const sctp_subtype_t type
,
3314 sctp_cmd_seq_t
*commands
)
3316 struct sctp_chunk
*chunk
= arg
;
3319 if (!sctp_vtag_verify(chunk
, asoc
))
3320 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3322 /* Make sure that the ERROR chunk has a valid length. */
3323 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_operr_chunk_t
)))
3324 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
3326 sctp_walk_errors(err
, chunk
->chunk_hdr
);
3327 if ((void *)err
!= (void *)chunk
->chunk_end
)
3328 return sctp_sf_violation_paramlen(net
, ep
, asoc
, type
, arg
,
3329 (void *)err
, commands
);
3331 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_OPERR
,
3334 return SCTP_DISPOSITION_CONSUME
;
3338 * Process an inbound SHUTDOWN ACK.
3341 * Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3342 * stop the T2-shutdown timer, send a SHUTDOWN COMPLETE chunk to its
3343 * peer, and remove all record of the association.
3345 * The return value is the disposition.
3347 sctp_disposition_t
sctp_sf_do_9_2_final(struct net
*net
,
3348 const struct sctp_endpoint
*ep
,
3349 const struct sctp_association
*asoc
,
3350 const sctp_subtype_t type
,
3352 sctp_cmd_seq_t
*commands
)
3354 struct sctp_chunk
*chunk
= arg
;
3355 struct sctp_chunk
*reply
;
3356 struct sctp_ulpevent
*ev
;
3358 if (!sctp_vtag_verify(chunk
, asoc
))
3359 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3361 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3362 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_chunkhdr
)))
3363 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
3365 /* 10.2 H) SHUTDOWN COMPLETE notification
3367 * When SCTP completes the shutdown procedures (section 9.2) this
3368 * notification is passed to the upper layer.
3370 ev
= sctp_ulpevent_make_assoc_change(asoc
, 0, SCTP_SHUTDOWN_COMP
,
3371 0, 0, 0, NULL
, GFP_ATOMIC
);
3375 /* ...send a SHUTDOWN COMPLETE chunk to its peer, */
3376 reply
= sctp_make_shutdown_complete(asoc
, chunk
);
3380 /* Do all the commands now (after allocation), so that we
3381 * have consistent state if memory allocation failes
3383 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(ev
));
3385 /* Upon the receipt of the SHUTDOWN ACK, the SHUTDOWN sender shall
3386 * stop the T2-shutdown timer,
3388 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3389 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
3391 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3392 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
3394 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
3395 SCTP_STATE(SCTP_STATE_CLOSED
));
3396 SCTP_INC_STATS(net
, SCTP_MIB_SHUTDOWNS
);
3397 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
3398 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
3400 /* ...and remove all record of the association. */
3401 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
3402 return SCTP_DISPOSITION_DELETE_TCB
;
3405 sctp_ulpevent_free(ev
);
3407 return SCTP_DISPOSITION_NOMEM
;
3411 * RFC 2960, 8.4 - Handle "Out of the blue" Packets, sctpimpguide 2.41.
3413 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3414 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3415 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3416 * packet must fill in the Verification Tag field of the outbound
3417 * packet with the Verification Tag received in the SHUTDOWN ACK and
3418 * set the T-bit in the Chunk Flags to indicate that the Verification
3421 * 8) The receiver should respond to the sender of the OOTB packet with
3422 * an ABORT. When sending the ABORT, the receiver of the OOTB packet
3423 * MUST fill in the Verification Tag field of the outbound packet
3424 * with the value found in the Verification Tag field of the OOTB
3425 * packet and set the T-bit in the Chunk Flags to indicate that the
3426 * Verification Tag is reflected. After sending this ABORT, the
3427 * receiver of the OOTB packet shall discard the OOTB packet and take
3428 * no further action.
3430 sctp_disposition_t
sctp_sf_ootb(struct net
*net
,
3431 const struct sctp_endpoint
*ep
,
3432 const struct sctp_association
*asoc
,
3433 const sctp_subtype_t type
,
3435 sctp_cmd_seq_t
*commands
)
3437 struct sctp_chunk
*chunk
= arg
;
3438 struct sk_buff
*skb
= chunk
->skb
;
3439 struct sctp_chunkhdr
*ch
;
3442 int ootb_shut_ack
= 0;
3443 int ootb_cookie_ack
= 0;
3445 SCTP_INC_STATS(net
, SCTP_MIB_OUTOFBLUES
);
3447 ch
= (struct sctp_chunkhdr
*)chunk
->chunk_hdr
;
3449 /* Report violation if the chunk is less then minimal */
3450 if (ntohs(ch
->length
) < sizeof(*ch
))
3451 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
3454 /* Report violation if chunk len overflows */
3455 ch_end
= ((__u8
*)ch
) + SCTP_PAD4(ntohs(ch
->length
));
3456 if (ch_end
> skb_tail_pointer(skb
))
3457 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
3460 /* Now that we know we at least have a chunk header,
3461 * do things that are type appropriate.
3463 if (SCTP_CID_SHUTDOWN_ACK
== ch
->type
)
3466 /* RFC 2960, Section 3.3.7
3467 * Moreover, under any circumstances, an endpoint that
3468 * receives an ABORT MUST NOT respond to that ABORT by
3469 * sending an ABORT of its own.
3471 if (SCTP_CID_ABORT
== ch
->type
)
3472 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3474 /* RFC 8.4, 7) If the packet contains a "Stale cookie" ERROR
3475 * or a COOKIE ACK the SCTP Packet should be silently
3479 if (SCTP_CID_COOKIE_ACK
== ch
->type
)
3480 ootb_cookie_ack
= 1;
3482 if (SCTP_CID_ERROR
== ch
->type
) {
3483 sctp_walk_errors(err
, ch
) {
3484 if (SCTP_ERROR_STALE_COOKIE
== err
->cause
) {
3485 ootb_cookie_ack
= 1;
3491 ch
= (struct sctp_chunkhdr
*)ch_end
;
3492 } while (ch_end
< skb_tail_pointer(skb
));
3495 return sctp_sf_shut_8_4_5(net
, ep
, asoc
, type
, arg
, commands
);
3496 else if (ootb_cookie_ack
)
3497 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3499 return sctp_sf_tabort_8_4_8(net
, ep
, asoc
, type
, arg
, commands
);
3503 * Handle an "Out of the blue" SHUTDOWN ACK.
3505 * Section: 8.4 5, sctpimpguide 2.41.
3507 * 5) If the packet contains a SHUTDOWN ACK chunk, the receiver should
3508 * respond to the sender of the OOTB packet with a SHUTDOWN COMPLETE.
3509 * When sending the SHUTDOWN COMPLETE, the receiver of the OOTB
3510 * packet must fill in the Verification Tag field of the outbound
3511 * packet with the Verification Tag received in the SHUTDOWN ACK and
3512 * set the T-bit in the Chunk Flags to indicate that the Verification
3516 * (endpoint, asoc, type, arg, commands)
3519 * (sctp_disposition_t)
3521 * The return value is the disposition of the chunk.
3523 static sctp_disposition_t
sctp_sf_shut_8_4_5(struct net
*net
,
3524 const struct sctp_endpoint
*ep
,
3525 const struct sctp_association
*asoc
,
3526 const sctp_subtype_t type
,
3528 sctp_cmd_seq_t
*commands
)
3530 struct sctp_packet
*packet
= NULL
;
3531 struct sctp_chunk
*chunk
= arg
;
3532 struct sctp_chunk
*shut
;
3534 packet
= sctp_ootb_pkt_new(net
, asoc
, chunk
);
3536 return SCTP_DISPOSITION_NOMEM
;
3538 /* Make an SHUTDOWN_COMPLETE.
3539 * The T bit will be set if the asoc is NULL.
3541 shut
= sctp_make_shutdown_complete(asoc
, chunk
);
3543 sctp_ootb_pkt_free(packet
);
3544 return SCTP_DISPOSITION_NOMEM
;
3547 /* Reflect vtag if T-Bit is set */
3548 if (sctp_test_T_bit(shut
))
3549 packet
->vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
3551 /* Set the skb to the belonging sock for accounting. */
3552 shut
->skb
->sk
= ep
->base
.sk
;
3554 sctp_packet_append_chunk(packet
, shut
);
3556 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
3557 SCTP_PACKET(packet
));
3559 SCTP_INC_STATS(net
, SCTP_MIB_OUTCTRLCHUNKS
);
3561 /* If the chunk length is invalid, we don't want to process
3562 * the reset of the packet.
3564 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_chunkhdr
)))
3565 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3567 /* We need to discard the rest of the packet to prevent
3568 * potential bomming attacks from additional bundled chunks.
3569 * This is documented in SCTP Threats ID.
3571 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3575 * Handle SHUTDOWN ACK in COOKIE_ECHOED or COOKIE_WAIT state.
3577 * Verification Tag: 8.5.1 E) Rules for packet carrying a SHUTDOWN ACK
3578 * If the receiver is in COOKIE-ECHOED or COOKIE-WAIT state the
3579 * procedures in section 8.4 SHOULD be followed, in other words it
3580 * should be treated as an Out Of The Blue packet.
3581 * [This means that we do NOT check the Verification Tag on these
3585 sctp_disposition_t
sctp_sf_do_8_5_1_E_sa(struct net
*net
,
3586 const struct sctp_endpoint
*ep
,
3587 const struct sctp_association
*asoc
,
3588 const sctp_subtype_t type
,
3590 sctp_cmd_seq_t
*commands
)
3592 struct sctp_chunk
*chunk
= arg
;
3594 /* Make sure that the SHUTDOWN_ACK chunk has a valid length. */
3595 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_chunkhdr
)))
3596 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
3599 /* Although we do have an association in this case, it corresponds
3600 * to a restarted association. So the packet is treated as an OOTB
3601 * packet and the state function that handles OOTB SHUTDOWN_ACK is
3602 * called with a NULL association.
3604 SCTP_INC_STATS(net
, SCTP_MIB_OUTOFBLUES
);
3606 return sctp_sf_shut_8_4_5(net
, ep
, NULL
, type
, arg
, commands
);
3609 /* ADDIP Section 4.2 Upon reception of an ASCONF Chunk. */
3610 sctp_disposition_t
sctp_sf_do_asconf(struct net
*net
,
3611 const struct sctp_endpoint
*ep
,
3612 const struct sctp_association
*asoc
,
3613 const sctp_subtype_t type
, void *arg
,
3614 sctp_cmd_seq_t
*commands
)
3616 struct sctp_chunk
*chunk
= arg
;
3617 struct sctp_chunk
*asconf_ack
= NULL
;
3618 struct sctp_paramhdr
*err_param
= NULL
;
3619 sctp_addiphdr_t
*hdr
;
3622 if (!sctp_vtag_verify(chunk
, asoc
)) {
3623 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3625 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3628 /* ADD-IP: Section 4.1.1
3629 * This chunk MUST be sent in an authenticated way by using
3630 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3631 * is received unauthenticated it MUST be silently discarded as
3632 * described in [I-D.ietf-tsvwg-sctp-auth].
3634 if (!net
->sctp
.addip_noauth
&& !chunk
->auth
)
3635 return sctp_sf_discard_chunk(net
, ep
, asoc
, type
, arg
, commands
);
3637 /* Make sure that the ASCONF ADDIP chunk has a valid length. */
3638 if (!sctp_chunk_length_valid(chunk
, sizeof(sctp_addip_chunk_t
)))
3639 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
3642 hdr
= (sctp_addiphdr_t
*)chunk
->skb
->data
;
3643 serial
= ntohl(hdr
->serial
);
3645 /* Verify the ASCONF chunk before processing it. */
3646 if (!sctp_verify_asconf(asoc
, chunk
, true, &err_param
))
3647 return sctp_sf_violation_paramlen(net
, ep
, asoc
, type
, arg
,
3648 (void *)err_param
, commands
);
3650 /* ADDIP 5.2 E1) Compare the value of the serial number to the value
3651 * the endpoint stored in a new association variable
3652 * 'Peer-Serial-Number'.
3654 if (serial
== asoc
->peer
.addip_serial
+ 1) {
3655 /* If this is the first instance of ASCONF in the packet,
3656 * we can clean our old ASCONF-ACKs.
3658 if (!chunk
->has_asconf
)
3659 sctp_assoc_clean_asconf_ack_cache(asoc
);
3661 /* ADDIP 5.2 E4) When the Sequence Number matches the next one
3662 * expected, process the ASCONF as described below and after
3663 * processing the ASCONF Chunk, append an ASCONF-ACK Chunk to
3664 * the response packet and cache a copy of it (in the event it
3665 * later needs to be retransmitted).
3667 * Essentially, do V1-V5.
3669 asconf_ack
= sctp_process_asconf((struct sctp_association
*)
3672 return SCTP_DISPOSITION_NOMEM
;
3673 } else if (serial
< asoc
->peer
.addip_serial
+ 1) {
3675 * If the value found in the Sequence Number is less than the
3676 * ('Peer- Sequence-Number' + 1), simply skip to the next
3677 * ASCONF, and include in the outbound response packet
3678 * any previously cached ASCONF-ACK response that was
3679 * sent and saved that matches the Sequence Number of the
3680 * ASCONF. Note: It is possible that no cached ASCONF-ACK
3681 * Chunk exists. This will occur when an older ASCONF
3682 * arrives out of order. In such a case, the receiver
3683 * should skip the ASCONF Chunk and not include ASCONF-ACK
3684 * Chunk for that chunk.
3686 asconf_ack
= sctp_assoc_lookup_asconf_ack(asoc
, hdr
->serial
);
3688 return SCTP_DISPOSITION_DISCARD
;
3690 /* Reset the transport so that we select the correct one
3691 * this time around. This is to make sure that we don't
3692 * accidentally use a stale transport that's been removed.
3694 asconf_ack
->transport
= NULL
;
3696 /* ADDIP 5.2 E5) Otherwise, the ASCONF Chunk is discarded since
3697 * it must be either a stale packet or from an attacker.
3699 return SCTP_DISPOSITION_DISCARD
;
3702 /* ADDIP 5.2 E6) The destination address of the SCTP packet
3703 * containing the ASCONF-ACK Chunks MUST be the source address of
3704 * the SCTP packet that held the ASCONF Chunks.
3706 * To do this properly, we'll set the destination address of the chunk
3707 * and at the transmit time, will try look up the transport to use.
3708 * Since ASCONFs may be bundled, the correct transport may not be
3709 * created until we process the entire packet, thus this workaround.
3711 asconf_ack
->dest
= chunk
->source
;
3712 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(asconf_ack
));
3713 if (asoc
->new_transport
) {
3714 sctp_sf_heartbeat(ep
, asoc
, type
, asoc
->new_transport
, commands
);
3715 ((struct sctp_association
*)asoc
)->new_transport
= NULL
;
3718 return SCTP_DISPOSITION_CONSUME
;
3722 * ADDIP Section 4.3 General rules for address manipulation
3723 * When building TLV parameters for the ASCONF Chunk that will add or
3724 * delete IP addresses the D0 to D13 rules should be applied:
3726 sctp_disposition_t
sctp_sf_do_asconf_ack(struct net
*net
,
3727 const struct sctp_endpoint
*ep
,
3728 const struct sctp_association
*asoc
,
3729 const sctp_subtype_t type
, void *arg
,
3730 sctp_cmd_seq_t
*commands
)
3732 struct sctp_chunk
*asconf_ack
= arg
;
3733 struct sctp_chunk
*last_asconf
= asoc
->addip_last_asconf
;
3734 struct sctp_chunk
*abort
;
3735 struct sctp_paramhdr
*err_param
= NULL
;
3736 sctp_addiphdr_t
*addip_hdr
;
3737 __u32 sent_serial
, rcvd_serial
;
3739 if (!sctp_vtag_verify(asconf_ack
, asoc
)) {
3740 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3742 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3745 /* ADD-IP, Section 4.1.2:
3746 * This chunk MUST be sent in an authenticated way by using
3747 * the mechanism defined in [I-D.ietf-tsvwg-sctp-auth]. If this chunk
3748 * is received unauthenticated it MUST be silently discarded as
3749 * described in [I-D.ietf-tsvwg-sctp-auth].
3751 if (!net
->sctp
.addip_noauth
&& !asconf_ack
->auth
)
3752 return sctp_sf_discard_chunk(net
, ep
, asoc
, type
, arg
, commands
);
3754 /* Make sure that the ADDIP chunk has a valid length. */
3755 if (!sctp_chunk_length_valid(asconf_ack
, sizeof(sctp_addip_chunk_t
)))
3756 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
3759 addip_hdr
= (sctp_addiphdr_t
*)asconf_ack
->skb
->data
;
3760 rcvd_serial
= ntohl(addip_hdr
->serial
);
3762 /* Verify the ASCONF-ACK chunk before processing it. */
3763 if (!sctp_verify_asconf(asoc
, asconf_ack
, false, &err_param
))
3764 return sctp_sf_violation_paramlen(net
, ep
, asoc
, type
, arg
,
3765 (void *)err_param
, commands
);
3768 addip_hdr
= (sctp_addiphdr_t
*)last_asconf
->subh
.addip_hdr
;
3769 sent_serial
= ntohl(addip_hdr
->serial
);
3771 sent_serial
= asoc
->addip_serial
- 1;
3774 /* D0) If an endpoint receives an ASCONF-ACK that is greater than or
3775 * equal to the next serial number to be used but no ASCONF chunk is
3776 * outstanding the endpoint MUST ABORT the association. Note that a
3777 * sequence number is greater than if it is no more than 2^^31-1
3778 * larger than the current sequence number (using serial arithmetic).
3780 if (ADDIP_SERIAL_gte(rcvd_serial
, sent_serial
+ 1) &&
3781 !(asoc
->addip_last_asconf
)) {
3782 abort
= sctp_make_abort(asoc
, asconf_ack
,
3783 sizeof(sctp_errhdr_t
));
3785 sctp_init_cause(abort
, SCTP_ERROR_ASCONF_ACK
, 0);
3786 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
3789 /* We are going to ABORT, so we might as well stop
3790 * processing the rest of the chunks in the packet.
3792 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3793 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
3794 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
, SCTP_NULL());
3795 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
3796 SCTP_ERROR(ECONNABORTED
));
3797 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
3798 SCTP_PERR(SCTP_ERROR_ASCONF_ACK
));
3799 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
3800 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
3801 return SCTP_DISPOSITION_ABORT
;
3804 if ((rcvd_serial
== sent_serial
) && asoc
->addip_last_asconf
) {
3805 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
3806 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
3808 if (!sctp_process_asconf_ack((struct sctp_association
*)asoc
,
3810 /* Successfully processed ASCONF_ACK. We can
3811 * release the next asconf if we have one.
3813 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_NEXT_ASCONF
,
3815 return SCTP_DISPOSITION_CONSUME
;
3818 abort
= sctp_make_abort(asoc
, asconf_ack
,
3819 sizeof(sctp_errhdr_t
));
3821 sctp_init_cause(abort
, SCTP_ERROR_RSRC_LOW
, 0);
3822 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
3825 /* We are going to ABORT, so we might as well stop
3826 * processing the rest of the chunks in the packet.
3828 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
, SCTP_NULL());
3829 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
3830 SCTP_ERROR(ECONNABORTED
));
3831 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
3832 SCTP_PERR(SCTP_ERROR_ASCONF_ACK
));
3833 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
3834 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
3835 return SCTP_DISPOSITION_ABORT
;
3838 return SCTP_DISPOSITION_DISCARD
;
3841 /* RE-CONFIG Section 5.2 Upon reception of an RECONF Chunk. */
3842 sctp_disposition_t
sctp_sf_do_reconf(struct net
*net
,
3843 const struct sctp_endpoint
*ep
,
3844 const struct sctp_association
*asoc
,
3845 const sctp_subtype_t type
, void *arg
,
3846 sctp_cmd_seq_t
*commands
)
3848 struct sctp_paramhdr
*err_param
= NULL
;
3849 struct sctp_chunk
*chunk
= arg
;
3850 struct sctp_reconf_chunk
*hdr
;
3851 union sctp_params param
;
3853 if (!sctp_vtag_verify(chunk
, asoc
)) {
3854 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3856 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3859 /* Make sure that the RECONF chunk has a valid length. */
3860 if (!sctp_chunk_length_valid(chunk
, sizeof(*hdr
)))
3861 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
3864 if (!sctp_verify_reconf(asoc
, chunk
, &err_param
))
3865 return sctp_sf_violation_paramlen(net
, ep
, asoc
, type
, arg
,
3866 (void *)err_param
, commands
);
3868 hdr
= (struct sctp_reconf_chunk
*)chunk
->chunk_hdr
;
3869 sctp_walk_params(param
, hdr
, params
) {
3870 struct sctp_chunk
*reply
= NULL
;
3871 struct sctp_ulpevent
*ev
= NULL
;
3873 if (param
.p
->type
== SCTP_PARAM_RESET_OUT_REQUEST
)
3874 reply
= sctp_process_strreset_outreq(
3875 (struct sctp_association
*)asoc
, param
, &ev
);
3876 else if (param
.p
->type
== SCTP_PARAM_RESET_IN_REQUEST
)
3877 reply
= sctp_process_strreset_inreq(
3878 (struct sctp_association
*)asoc
, param
, &ev
);
3879 else if (param
.p
->type
== SCTP_PARAM_RESET_TSN_REQUEST
)
3880 reply
= sctp_process_strreset_tsnreq(
3881 (struct sctp_association
*)asoc
, param
, &ev
);
3882 else if (param
.p
->type
== SCTP_PARAM_RESET_ADD_OUT_STREAMS
)
3883 reply
= sctp_process_strreset_addstrm_out(
3884 (struct sctp_association
*)asoc
, param
, &ev
);
3885 else if (param
.p
->type
== SCTP_PARAM_RESET_ADD_IN_STREAMS
)
3886 reply
= sctp_process_strreset_addstrm_in(
3887 (struct sctp_association
*)asoc
, param
, &ev
);
3888 else if (param
.p
->type
== SCTP_PARAM_RESET_RESPONSE
)
3889 reply
= sctp_process_strreset_resp(
3890 (struct sctp_association
*)asoc
, param
, &ev
);
3893 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
3897 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
3901 return SCTP_DISPOSITION_CONSUME
;
3905 * PR-SCTP Section 3.6 Receiver Side Implementation of PR-SCTP
3907 * When a FORWARD TSN chunk arrives, the data receiver MUST first update
3908 * its cumulative TSN point to the value carried in the FORWARD TSN
3909 * chunk, and then MUST further advance its cumulative TSN point locally
3911 * After the above processing, the data receiver MUST stop reporting any
3912 * missing TSNs earlier than or equal to the new cumulative TSN point.
3914 * Verification Tag: 8.5 Verification Tag [Normal verification]
3916 * The return value is the disposition of the chunk.
3918 sctp_disposition_t
sctp_sf_eat_fwd_tsn(struct net
*net
,
3919 const struct sctp_endpoint
*ep
,
3920 const struct sctp_association
*asoc
,
3921 const sctp_subtype_t type
,
3923 sctp_cmd_seq_t
*commands
)
3925 struct sctp_chunk
*chunk
= arg
;
3926 struct sctp_fwdtsn_hdr
*fwdtsn_hdr
;
3927 struct sctp_fwdtsn_skip
*skip
;
3931 if (!sctp_vtag_verify(chunk
, asoc
)) {
3932 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
3934 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
3937 if (!asoc
->peer
.prsctp_capable
)
3938 return sctp_sf_unk_chunk(net
, ep
, asoc
, type
, arg
, commands
);
3940 /* Make sure that the FORWARD_TSN chunk has valid length. */
3941 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_fwdtsn_chunk
)))
3942 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
3945 fwdtsn_hdr
= (struct sctp_fwdtsn_hdr
*)chunk
->skb
->data
;
3946 chunk
->subh
.fwdtsn_hdr
= fwdtsn_hdr
;
3947 len
= ntohs(chunk
->chunk_hdr
->length
);
3948 len
-= sizeof(struct sctp_chunkhdr
);
3949 skb_pull(chunk
->skb
, len
);
3951 tsn
= ntohl(fwdtsn_hdr
->new_cum_tsn
);
3952 pr_debug("%s: TSN 0x%x\n", __func__
, tsn
);
3954 /* The TSN is too high--silently discard the chunk and count on it
3955 * getting retransmitted later.
3957 if (sctp_tsnmap_check(&asoc
->peer
.tsn_map
, tsn
) < 0)
3958 goto discard_noforce
;
3960 /* Silently discard the chunk if stream-id is not valid */
3961 sctp_walk_fwdtsn(skip
, chunk
) {
3962 if (ntohs(skip
->stream
) >= asoc
->stream
.incnt
)
3963 goto discard_noforce
;
3966 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_FWDTSN
, SCTP_U32(tsn
));
3967 if (len
> sizeof(struct sctp_fwdtsn_hdr
))
3968 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_FWDTSN
,
3971 /* Count this as receiving DATA. */
3972 if (asoc
->timeouts
[SCTP_EVENT_TIMEOUT_AUTOCLOSE
]) {
3973 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
3974 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
3977 /* FIXME: For now send a SACK, but DATA processing may
3980 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_NOFORCE());
3982 return SCTP_DISPOSITION_CONSUME
;
3985 return SCTP_DISPOSITION_DISCARD
;
3988 sctp_disposition_t
sctp_sf_eat_fwd_tsn_fast(
3990 const struct sctp_endpoint
*ep
,
3991 const struct sctp_association
*asoc
,
3992 const sctp_subtype_t type
,
3994 sctp_cmd_seq_t
*commands
)
3996 struct sctp_chunk
*chunk
= arg
;
3997 struct sctp_fwdtsn_hdr
*fwdtsn_hdr
;
3998 struct sctp_fwdtsn_skip
*skip
;
4002 if (!sctp_vtag_verify(chunk
, asoc
)) {
4003 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
4005 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
4008 if (!asoc
->peer
.prsctp_capable
)
4009 return sctp_sf_unk_chunk(net
, ep
, asoc
, type
, arg
, commands
);
4011 /* Make sure that the FORWARD_TSN chunk has a valid length. */
4012 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_fwdtsn_chunk
)))
4013 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
4016 fwdtsn_hdr
= (struct sctp_fwdtsn_hdr
*)chunk
->skb
->data
;
4017 chunk
->subh
.fwdtsn_hdr
= fwdtsn_hdr
;
4018 len
= ntohs(chunk
->chunk_hdr
->length
);
4019 len
-= sizeof(struct sctp_chunkhdr
);
4020 skb_pull(chunk
->skb
, len
);
4022 tsn
= ntohl(fwdtsn_hdr
->new_cum_tsn
);
4023 pr_debug("%s: TSN 0x%x\n", __func__
, tsn
);
4025 /* The TSN is too high--silently discard the chunk and count on it
4026 * getting retransmitted later.
4028 if (sctp_tsnmap_check(&asoc
->peer
.tsn_map
, tsn
) < 0)
4031 /* Silently discard the chunk if stream-id is not valid */
4032 sctp_walk_fwdtsn(skip
, chunk
) {
4033 if (ntohs(skip
->stream
) >= asoc
->stream
.incnt
)
4037 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_FWDTSN
, SCTP_U32(tsn
));
4038 if (len
> sizeof(struct sctp_fwdtsn_hdr
))
4039 sctp_add_cmd_sf(commands
, SCTP_CMD_PROCESS_FWDTSN
,
4042 /* Go a head and force a SACK, since we are shutting down. */
4044 /* Implementor's Guide.
4046 * While in SHUTDOWN-SENT state, the SHUTDOWN sender MUST immediately
4047 * respond to each received packet containing one or more DATA chunk(s)
4048 * with a SACK, a SHUTDOWN chunk, and restart the T2-shutdown timer
4050 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SHUTDOWN
, SCTP_NULL());
4051 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_FORCE());
4052 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
4053 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
4055 return SCTP_DISPOSITION_CONSUME
;
4059 * SCTP-AUTH Section 6.3 Receiving authenticated chukns
4061 * The receiver MUST use the HMAC algorithm indicated in the HMAC
4062 * Identifier field. If this algorithm was not specified by the
4063 * receiver in the HMAC-ALGO parameter in the INIT or INIT-ACK chunk
4064 * during association setup, the AUTH chunk and all chunks after it MUST
4065 * be discarded and an ERROR chunk SHOULD be sent with the error cause
4066 * defined in Section 4.1.
4068 * If an endpoint with no shared key receives a Shared Key Identifier
4069 * other than 0, it MUST silently discard all authenticated chunks. If
4070 * the endpoint has at least one endpoint pair shared key for the peer,
4071 * it MUST use the key specified by the Shared Key Identifier if a
4072 * key has been configured for that Shared Key Identifier. If no
4073 * endpoint pair shared key has been configured for that Shared Key
4074 * Identifier, all authenticated chunks MUST be silently discarded.
4076 * Verification Tag: 8.5 Verification Tag [Normal verification]
4078 * The return value is the disposition of the chunk.
4080 static sctp_ierror_t
sctp_sf_authenticate(struct net
*net
,
4081 const struct sctp_endpoint
*ep
,
4082 const struct sctp_association
*asoc
,
4083 const sctp_subtype_t type
,
4084 struct sctp_chunk
*chunk
)
4086 struct sctp_authhdr
*auth_hdr
;
4087 struct sctp_hmac
*hmac
;
4088 unsigned int sig_len
;
4093 /* Pull in the auth header, so we can do some more verification */
4094 auth_hdr
= (struct sctp_authhdr
*)chunk
->skb
->data
;
4095 chunk
->subh
.auth_hdr
= auth_hdr
;
4096 skb_pull(chunk
->skb
, sizeof(struct sctp_authhdr
));
4098 /* Make sure that we support the HMAC algorithm from the auth
4101 if (!sctp_auth_asoc_verify_hmac_id(asoc
, auth_hdr
->hmac_id
))
4102 return SCTP_IERROR_AUTH_BAD_HMAC
;
4104 /* Make sure that the provided shared key identifier has been
4107 key_id
= ntohs(auth_hdr
->shkey_id
);
4108 if (key_id
!= asoc
->active_key_id
&& !sctp_auth_get_shkey(asoc
, key_id
))
4109 return SCTP_IERROR_AUTH_BAD_KEYID
;
4112 /* Make sure that the length of the signature matches what
4115 sig_len
= ntohs(chunk
->chunk_hdr
->length
) - sizeof(sctp_auth_chunk_t
);
4116 hmac
= sctp_auth_get_hmac(ntohs(auth_hdr
->hmac_id
));
4117 if (sig_len
!= hmac
->hmac_len
)
4118 return SCTP_IERROR_PROTO_VIOLATION
;
4120 /* Now that we've done validation checks, we can compute and
4121 * verify the hmac. The steps involved are:
4122 * 1. Save the digest from the chunk.
4123 * 2. Zero out the digest in the chunk.
4124 * 3. Compute the new digest
4125 * 4. Compare saved and new digests.
4127 digest
= auth_hdr
->hmac
;
4128 skb_pull(chunk
->skb
, sig_len
);
4130 save_digest
= kmemdup(digest
, sig_len
, GFP_ATOMIC
);
4134 memset(digest
, 0, sig_len
);
4136 sctp_auth_calculate_hmac(asoc
, chunk
->skb
,
4137 (struct sctp_auth_chunk
*)chunk
->chunk_hdr
,
4140 /* Discard the packet if the digests do not match */
4141 if (memcmp(save_digest
, digest
, sig_len
)) {
4143 return SCTP_IERROR_BAD_SIG
;
4149 return SCTP_IERROR_NO_ERROR
;
4151 return SCTP_IERROR_NOMEM
;
4154 sctp_disposition_t
sctp_sf_eat_auth(struct net
*net
,
4155 const struct sctp_endpoint
*ep
,
4156 const struct sctp_association
*asoc
,
4157 const sctp_subtype_t type
,
4159 sctp_cmd_seq_t
*commands
)
4161 struct sctp_authhdr
*auth_hdr
;
4162 struct sctp_chunk
*chunk
= arg
;
4163 struct sctp_chunk
*err_chunk
;
4164 sctp_ierror_t error
;
4166 /* Make sure that the peer has AUTH capable */
4167 if (!asoc
->peer
.auth_capable
)
4168 return sctp_sf_unk_chunk(net
, ep
, asoc
, type
, arg
, commands
);
4170 if (!sctp_vtag_verify(chunk
, asoc
)) {
4171 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_BAD_TAG
,
4173 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
4176 /* Make sure that the AUTH chunk has valid length. */
4177 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_auth_chunk
)))
4178 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
4181 auth_hdr
= (struct sctp_authhdr
*)chunk
->skb
->data
;
4182 error
= sctp_sf_authenticate(net
, ep
, asoc
, type
, chunk
);
4184 case SCTP_IERROR_AUTH_BAD_HMAC
:
4185 /* Generate the ERROR chunk and discard the rest
4188 err_chunk
= sctp_make_op_error(asoc
, chunk
,
4189 SCTP_ERROR_UNSUP_HMAC
,
4193 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
4194 SCTP_CHUNK(err_chunk
));
4197 case SCTP_IERROR_AUTH_BAD_KEYID
:
4198 case SCTP_IERROR_BAD_SIG
:
4199 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
4201 case SCTP_IERROR_PROTO_VIOLATION
:
4202 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
4205 case SCTP_IERROR_NOMEM
:
4206 return SCTP_DISPOSITION_NOMEM
;
4208 default: /* Prevent gcc warnings */
4212 if (asoc
->active_key_id
!= ntohs(auth_hdr
->shkey_id
)) {
4213 struct sctp_ulpevent
*ev
;
4215 ev
= sctp_ulpevent_make_authkey(asoc
, ntohs(auth_hdr
->shkey_id
),
4216 SCTP_AUTH_NEWKEY
, GFP_ATOMIC
);
4221 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
,
4225 return SCTP_DISPOSITION_CONSUME
;
4229 * Process an unknown chunk.
4231 * Section: 3.2. Also, 2.1 in the implementor's guide.
4233 * Chunk Types are encoded such that the highest-order two bits specify
4234 * the action that must be taken if the processing endpoint does not
4235 * recognize the Chunk Type.
4237 * 00 - Stop processing this SCTP packet and discard it, do not process
4238 * any further chunks within it.
4240 * 01 - Stop processing this SCTP packet and discard it, do not process
4241 * any further chunks within it, and report the unrecognized
4242 * chunk in an 'Unrecognized Chunk Type'.
4244 * 10 - Skip this chunk and continue processing.
4246 * 11 - Skip this chunk and continue processing, but report in an ERROR
4247 * Chunk using the 'Unrecognized Chunk Type' cause of error.
4249 * The return value is the disposition of the chunk.
4251 sctp_disposition_t
sctp_sf_unk_chunk(struct net
*net
,
4252 const struct sctp_endpoint
*ep
,
4253 const struct sctp_association
*asoc
,
4254 const sctp_subtype_t type
,
4256 sctp_cmd_seq_t
*commands
)
4258 struct sctp_chunk
*unk_chunk
= arg
;
4259 struct sctp_chunk
*err_chunk
;
4260 struct sctp_chunkhdr
*hdr
;
4262 pr_debug("%s: processing unknown chunk id:%d\n", __func__
, type
.chunk
);
4264 if (!sctp_vtag_verify(unk_chunk
, asoc
))
4265 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
4267 /* Make sure that the chunk has a valid length.
4268 * Since we don't know the chunk type, we use a general
4269 * chunkhdr structure to make a comparison.
4271 if (!sctp_chunk_length_valid(unk_chunk
, sizeof(*hdr
)))
4272 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
4275 switch (type
.chunk
& SCTP_CID_ACTION_MASK
) {
4276 case SCTP_CID_ACTION_DISCARD
:
4277 /* Discard the packet. */
4278 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
4279 case SCTP_CID_ACTION_DISCARD_ERR
:
4280 /* Generate an ERROR chunk as response. */
4281 hdr
= unk_chunk
->chunk_hdr
;
4282 err_chunk
= sctp_make_op_error(asoc
, unk_chunk
,
4283 SCTP_ERROR_UNKNOWN_CHUNK
, hdr
,
4284 SCTP_PAD4(ntohs(hdr
->length
)),
4287 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
4288 SCTP_CHUNK(err_chunk
));
4291 /* Discard the packet. */
4292 sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
4293 return SCTP_DISPOSITION_CONSUME
;
4294 case SCTP_CID_ACTION_SKIP
:
4295 /* Skip the chunk. */
4296 return SCTP_DISPOSITION_DISCARD
;
4297 case SCTP_CID_ACTION_SKIP_ERR
:
4298 /* Generate an ERROR chunk as response. */
4299 hdr
= unk_chunk
->chunk_hdr
;
4300 err_chunk
= sctp_make_op_error(asoc
, unk_chunk
,
4301 SCTP_ERROR_UNKNOWN_CHUNK
, hdr
,
4302 SCTP_PAD4(ntohs(hdr
->length
)),
4305 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
4306 SCTP_CHUNK(err_chunk
));
4308 /* Skip the chunk. */
4309 return SCTP_DISPOSITION_CONSUME
;
4314 return SCTP_DISPOSITION_DISCARD
;
4318 * Discard the chunk.
4320 * Section: 0.2, 5.2.3, 5.2.5, 5.2.6, 6.0, 8.4.6, 8.5.1c, 9.2
4321 * [Too numerous to mention...]
4322 * Verification Tag: No verification needed.
4324 * (endpoint, asoc, chunk)
4327 * (asoc, reply_msg, msg_up, timers, counters)
4329 * The return value is the disposition of the chunk.
4331 sctp_disposition_t
sctp_sf_discard_chunk(struct net
*net
,
4332 const struct sctp_endpoint
*ep
,
4333 const struct sctp_association
*asoc
,
4334 const sctp_subtype_t type
,
4336 sctp_cmd_seq_t
*commands
)
4338 struct sctp_chunk
*chunk
= arg
;
4340 /* Make sure that the chunk has a valid length.
4341 * Since we don't know the chunk type, we use a general
4342 * chunkhdr structure to make a comparison.
4344 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_chunkhdr
)))
4345 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
4348 pr_debug("%s: chunk:%d is discarded\n", __func__
, type
.chunk
);
4350 return SCTP_DISPOSITION_DISCARD
;
4354 * Discard the whole packet.
4358 * 2) If the OOTB packet contains an ABORT chunk, the receiver MUST
4359 * silently discard the OOTB packet and take no further action.
4361 * Verification Tag: No verification necessary
4364 * (endpoint, asoc, chunk)
4367 * (asoc, reply_msg, msg_up, timers, counters)
4369 * The return value is the disposition of the chunk.
4371 sctp_disposition_t
sctp_sf_pdiscard(struct net
*net
,
4372 const struct sctp_endpoint
*ep
,
4373 const struct sctp_association
*asoc
,
4374 const sctp_subtype_t type
,
4376 sctp_cmd_seq_t
*commands
)
4378 SCTP_INC_STATS(net
, SCTP_MIB_IN_PKT_DISCARDS
);
4379 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
, SCTP_NULL());
4381 return SCTP_DISPOSITION_CONSUME
;
4386 * The other end is violating protocol.
4388 * Section: Not specified
4389 * Verification Tag: Not specified
4391 * (endpoint, asoc, chunk)
4394 * (asoc, reply_msg, msg_up, timers, counters)
4396 * We simply tag the chunk as a violation. The state machine will log
4397 * the violation and continue.
4399 sctp_disposition_t
sctp_sf_violation(struct net
*net
,
4400 const struct sctp_endpoint
*ep
,
4401 const struct sctp_association
*asoc
,
4402 const sctp_subtype_t type
,
4404 sctp_cmd_seq_t
*commands
)
4406 struct sctp_chunk
*chunk
= arg
;
4408 /* Make sure that the chunk has a valid length. */
4409 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_chunkhdr
)))
4410 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
4413 return SCTP_DISPOSITION_VIOLATION
;
4417 * Common function to handle a protocol violation.
4419 static sctp_disposition_t
sctp_sf_abort_violation(
4421 const struct sctp_endpoint
*ep
,
4422 const struct sctp_association
*asoc
,
4424 sctp_cmd_seq_t
*commands
,
4425 const __u8
*payload
,
4426 const size_t paylen
)
4428 struct sctp_packet
*packet
= NULL
;
4429 struct sctp_chunk
*chunk
= arg
;
4430 struct sctp_chunk
*abort
= NULL
;
4432 /* SCTP-AUTH, Section 6.3:
4433 * It should be noted that if the receiver wants to tear
4434 * down an association in an authenticated way only, the
4435 * handling of malformed packets should not result in
4436 * tearing down the association.
4438 * This means that if we only want to abort associations
4439 * in an authenticated way (i.e AUTH+ABORT), then we
4440 * can't destroy this association just because the packet
4443 if (sctp_auth_recv_cid(SCTP_CID_ABORT
, asoc
))
4446 /* Make the abort chunk. */
4447 abort
= sctp_make_abort_violation(asoc
, chunk
, payload
, paylen
);
4452 /* Treat INIT-ACK as a special case during COOKIE-WAIT. */
4453 if (chunk
->chunk_hdr
->type
== SCTP_CID_INIT_ACK
&&
4454 !asoc
->peer
.i
.init_tag
) {
4455 sctp_initack_chunk_t
*initack
;
4457 initack
= (sctp_initack_chunk_t
*)chunk
->chunk_hdr
;
4458 if (!sctp_chunk_length_valid(chunk
,
4459 sizeof(sctp_initack_chunk_t
)))
4460 abort
->chunk_hdr
->flags
|= SCTP_CHUNK_FLAG_T
;
4462 unsigned int inittag
;
4464 inittag
= ntohl(initack
->init_hdr
.init_tag
);
4465 sctp_add_cmd_sf(commands
, SCTP_CMD_UPDATE_INITTAG
,
4470 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(abort
));
4471 SCTP_INC_STATS(net
, SCTP_MIB_OUTCTRLCHUNKS
);
4473 if (asoc
->state
<= SCTP_STATE_COOKIE_ECHOED
) {
4474 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4475 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
4476 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
4477 SCTP_ERROR(ECONNREFUSED
));
4478 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
4479 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION
));
4481 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
4482 SCTP_ERROR(ECONNABORTED
));
4483 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
4484 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION
));
4485 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
4488 packet
= sctp_ootb_pkt_new(net
, asoc
, chunk
);
4493 if (sctp_test_T_bit(abort
))
4494 packet
->vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
4496 abort
->skb
->sk
= ep
->base
.sk
;
4498 sctp_packet_append_chunk(packet
, abort
);
4500 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
4501 SCTP_PACKET(packet
));
4503 SCTP_INC_STATS(net
, SCTP_MIB_OUTCTRLCHUNKS
);
4506 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
4509 sctp_sf_pdiscard(net
, ep
, asoc
, SCTP_ST_CHUNK(0), arg
, commands
);
4510 return SCTP_DISPOSITION_ABORT
;
4513 sctp_chunk_free(abort
);
4515 return SCTP_DISPOSITION_NOMEM
;
4519 * Handle a protocol violation when the chunk length is invalid.
4520 * "Invalid" length is identified as smaller than the minimal length a
4521 * given chunk can be. For example, a SACK chunk has invalid length
4522 * if its length is set to be smaller than the size of sctp_sack_chunk_t.
4524 * We inform the other end by sending an ABORT with a Protocol Violation
4527 * Section: Not specified
4528 * Verification Tag: Nothing to do
4530 * (endpoint, asoc, chunk)
4533 * (reply_msg, msg_up, counters)
4535 * Generate an ABORT chunk and terminate the association.
4537 static sctp_disposition_t
sctp_sf_violation_chunklen(
4539 const struct sctp_endpoint
*ep
,
4540 const struct sctp_association
*asoc
,
4541 const sctp_subtype_t type
,
4543 sctp_cmd_seq_t
*commands
)
4545 static const char err_str
[] = "The following chunk had invalid length:";
4547 return sctp_sf_abort_violation(net
, ep
, asoc
, arg
, commands
, err_str
,
4552 * Handle a protocol violation when the parameter length is invalid.
4553 * If the length is smaller than the minimum length of a given parameter,
4554 * or accumulated length in multi parameters exceeds the end of the chunk,
4555 * the length is considered as invalid.
4557 static sctp_disposition_t
sctp_sf_violation_paramlen(
4559 const struct sctp_endpoint
*ep
,
4560 const struct sctp_association
*asoc
,
4561 const sctp_subtype_t type
,
4562 void *arg
, void *ext
,
4563 sctp_cmd_seq_t
*commands
)
4565 struct sctp_chunk
*chunk
= arg
;
4566 struct sctp_paramhdr
*param
= ext
;
4567 struct sctp_chunk
*abort
= NULL
;
4569 if (sctp_auth_recv_cid(SCTP_CID_ABORT
, asoc
))
4572 /* Make the abort chunk. */
4573 abort
= sctp_make_violation_paramlen(asoc
, chunk
, param
);
4577 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(abort
));
4578 SCTP_INC_STATS(net
, SCTP_MIB_OUTCTRLCHUNKS
);
4580 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
4581 SCTP_ERROR(ECONNABORTED
));
4582 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
4583 SCTP_PERR(SCTP_ERROR_PROTO_VIOLATION
));
4584 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
4585 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
4588 sctp_sf_pdiscard(net
, ep
, asoc
, SCTP_ST_CHUNK(0), arg
, commands
);
4589 return SCTP_DISPOSITION_ABORT
;
4591 return SCTP_DISPOSITION_NOMEM
;
4594 /* Handle a protocol violation when the peer trying to advance the
4595 * cumulative tsn ack to a point beyond the max tsn currently sent.
4597 * We inform the other end by sending an ABORT with a Protocol Violation
4600 static sctp_disposition_t
sctp_sf_violation_ctsn(
4602 const struct sctp_endpoint
*ep
,
4603 const struct sctp_association
*asoc
,
4604 const sctp_subtype_t type
,
4606 sctp_cmd_seq_t
*commands
)
4608 static const char err_str
[] = "The cumulative tsn ack beyond the max tsn currently sent:";
4610 return sctp_sf_abort_violation(net
, ep
, asoc
, arg
, commands
, err_str
,
4614 /* Handle protocol violation of an invalid chunk bundling. For example,
4615 * when we have an association and we receive bundled INIT-ACK, or
4616 * SHUDOWN-COMPLETE, our peer is clearly violationg the "MUST NOT bundle"
4617 * statement from the specs. Additionally, there might be an attacker
4618 * on the path and we may not want to continue this communication.
4620 static sctp_disposition_t
sctp_sf_violation_chunk(
4622 const struct sctp_endpoint
*ep
,
4623 const struct sctp_association
*asoc
,
4624 const sctp_subtype_t type
,
4626 sctp_cmd_seq_t
*commands
)
4628 static const char err_str
[] = "The following chunk violates protocol:";
4631 return sctp_sf_violation(net
, ep
, asoc
, type
, arg
, commands
);
4633 return sctp_sf_abort_violation(net
, ep
, asoc
, arg
, commands
, err_str
,
4636 /***************************************************************************
4637 * These are the state functions for handling primitive (Section 10) events.
4638 ***************************************************************************/
4640 * sctp_sf_do_prm_asoc
4642 * Section: 10.1 ULP-to-SCTP
4645 * Format: ASSOCIATE(local SCTP instance name, destination transport addr,
4646 * outbound stream count)
4647 * -> association id [,destination transport addr list] [,outbound stream
4650 * This primitive allows the upper layer to initiate an association to a
4651 * specific peer endpoint.
4653 * The peer endpoint shall be specified by one of the transport addresses
4654 * which defines the endpoint (see Section 1.4). If the local SCTP
4655 * instance has not been initialized, the ASSOCIATE is considered an
4657 * [This is not relevant for the kernel implementation since we do all
4658 * initialization at boot time. It we hadn't initialized we wouldn't
4659 * get anywhere near this code.]
4661 * An association id, which is a local handle to the SCTP association,
4662 * will be returned on successful establishment of the association. If
4663 * SCTP is not able to open an SCTP association with the peer endpoint,
4664 * an error is returned.
4665 * [In the kernel implementation, the struct sctp_association needs to
4666 * be created BEFORE causing this primitive to run.]
4668 * Other association parameters may be returned, including the
4669 * complete destination transport addresses of the peer as well as the
4670 * outbound stream count of the local endpoint. One of the transport
4671 * address from the returned destination addresses will be selected by
4672 * the local endpoint as default primary path for sending SCTP packets
4673 * to this peer. The returned "destination transport addr list" can
4674 * be used by the ULP to change the default primary path or to force
4675 * sending a packet to a specific transport address. [All of this
4676 * stuff happens when the INIT ACK arrives. This is a NON-BLOCKING
4679 * Mandatory attributes:
4681 * o local SCTP instance name - obtained from the INITIALIZE operation.
4682 * [This is the argument asoc.]
4683 * o destination transport addr - specified as one of the transport
4684 * addresses of the peer endpoint with which the association is to be
4686 * [This is asoc->peer.active_path.]
4687 * o outbound stream count - the number of outbound streams the ULP
4688 * would like to open towards this peer endpoint.
4689 * [BUG: This is not currently implemented.]
4690 * Optional attributes:
4694 * The return value is a disposition.
4696 sctp_disposition_t
sctp_sf_do_prm_asoc(struct net
*net
,
4697 const struct sctp_endpoint
*ep
,
4698 const struct sctp_association
*asoc
,
4699 const sctp_subtype_t type
,
4701 sctp_cmd_seq_t
*commands
)
4703 struct sctp_chunk
*repl
;
4704 struct sctp_association
*my_asoc
;
4706 /* The comment below says that we enter COOKIE-WAIT AFTER
4707 * sending the INIT, but that doesn't actually work in our
4710 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
4711 SCTP_STATE(SCTP_STATE_COOKIE_WAIT
));
4713 /* RFC 2960 5.1 Normal Establishment of an Association
4715 * A) "A" first sends an INIT chunk to "Z". In the INIT, "A"
4716 * must provide its Verification Tag (Tag_A) in the Initiate
4717 * Tag field. Tag_A SHOULD be a random number in the range of
4718 * 1 to 4294967295 (see 5.3.1 for Tag value selection). ...
4721 repl
= sctp_make_init(asoc
, &asoc
->base
.bind_addr
, GFP_ATOMIC
, 0);
4725 /* Choose transport for INIT. */
4726 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_CHOOSE_TRANSPORT
,
4729 /* Cast away the const modifier, as we want to just
4730 * rerun it through as a sideffect.
4732 my_asoc
= (struct sctp_association
*)asoc
;
4733 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_ASOC
, SCTP_ASOC(my_asoc
));
4735 /* After sending the INIT, "A" starts the T1-init timer and
4736 * enters the COOKIE-WAIT state.
4738 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
4739 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
4740 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
4741 return SCTP_DISPOSITION_CONSUME
;
4744 return SCTP_DISPOSITION_NOMEM
;
4748 * Process the SEND primitive.
4750 * Section: 10.1 ULP-to-SCTP
4753 * Format: SEND(association id, buffer address, byte count [,context]
4754 * [,stream id] [,life time] [,destination transport address]
4755 * [,unorder flag] [,no-bundle flag] [,payload protocol-id] )
4758 * This is the main method to send user data via SCTP.
4760 * Mandatory attributes:
4762 * o association id - local handle to the SCTP association
4764 * o buffer address - the location where the user message to be
4765 * transmitted is stored;
4767 * o byte count - The size of the user data in number of bytes;
4769 * Optional attributes:
4771 * o context - an optional 32 bit integer that will be carried in the
4772 * sending failure notification to the ULP if the transportation of
4773 * this User Message fails.
4775 * o stream id - to indicate which stream to send the data on. If not
4776 * specified, stream 0 will be used.
4778 * o life time - specifies the life time of the user data. The user data
4779 * will not be sent by SCTP after the life time expires. This
4780 * parameter can be used to avoid efforts to transmit stale
4781 * user messages. SCTP notifies the ULP if the data cannot be
4782 * initiated to transport (i.e. sent to the destination via SCTP's
4783 * send primitive) within the life time variable. However, the
4784 * user data will be transmitted if SCTP has attempted to transmit a
4785 * chunk before the life time expired.
4787 * o destination transport address - specified as one of the destination
4788 * transport addresses of the peer endpoint to which this packet
4789 * should be sent. Whenever possible, SCTP should use this destination
4790 * transport address for sending the packets, instead of the current
4793 * o unorder flag - this flag, if present, indicates that the user
4794 * would like the data delivered in an unordered fashion to the peer
4795 * (i.e., the U flag is set to 1 on all DATA chunks carrying this
4798 * o no-bundle flag - instructs SCTP not to bundle this user data with
4799 * other outbound DATA chunks. SCTP MAY still bundle even when
4800 * this flag is present, when faced with network congestion.
4802 * o payload protocol-id - A 32 bit unsigned integer that is to be
4803 * passed to the peer indicating the type of payload protocol data
4804 * being transmitted. This value is passed as opaque data by SCTP.
4806 * The return value is the disposition.
4808 sctp_disposition_t
sctp_sf_do_prm_send(struct net
*net
,
4809 const struct sctp_endpoint
*ep
,
4810 const struct sctp_association
*asoc
,
4811 const sctp_subtype_t type
,
4813 sctp_cmd_seq_t
*commands
)
4815 struct sctp_datamsg
*msg
= arg
;
4817 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_MSG
, SCTP_DATAMSG(msg
));
4818 return SCTP_DISPOSITION_CONSUME
;
4822 * Process the SHUTDOWN primitive.
4827 * Format: SHUTDOWN(association id)
4830 * Gracefully closes an association. Any locally queued user data
4831 * will be delivered to the peer. The association will be terminated only
4832 * after the peer acknowledges all the SCTP packets sent. A success code
4833 * will be returned on successful termination of the association. If
4834 * attempting to terminate the association results in a failure, an error
4835 * code shall be returned.
4837 * Mandatory attributes:
4839 * o association id - local handle to the SCTP association
4841 * Optional attributes:
4845 * The return value is the disposition.
4847 sctp_disposition_t
sctp_sf_do_9_2_prm_shutdown(
4849 const struct sctp_endpoint
*ep
,
4850 const struct sctp_association
*asoc
,
4851 const sctp_subtype_t type
,
4853 sctp_cmd_seq_t
*commands
)
4857 /* From 9.2 Shutdown of an Association
4858 * Upon receipt of the SHUTDOWN primitive from its upper
4859 * layer, the endpoint enters SHUTDOWN-PENDING state and
4860 * remains there until all outstanding data has been
4861 * acknowledged by its peer. The endpoint accepts no new data
4862 * from its upper layer, but retransmits data to the far end
4863 * if necessary to fill gaps.
4865 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
4866 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING
));
4868 disposition
= SCTP_DISPOSITION_CONSUME
;
4869 if (sctp_outq_is_empty(&asoc
->outqueue
)) {
4870 disposition
= sctp_sf_do_9_2_start_shutdown(net
, ep
, asoc
, type
,
4877 * Process the ABORT primitive.
4882 * Format: Abort(association id [, cause code])
4885 * Ungracefully closes an association. Any locally queued user data
4886 * will be discarded and an ABORT chunk is sent to the peer. A success code
4887 * will be returned on successful abortion of the association. If
4888 * attempting to abort the association results in a failure, an error
4889 * code shall be returned.
4891 * Mandatory attributes:
4893 * o association id - local handle to the SCTP association
4895 * Optional attributes:
4897 * o cause code - reason of the abort to be passed to the peer
4901 * The return value is the disposition.
4903 sctp_disposition_t
sctp_sf_do_9_1_prm_abort(
4905 const struct sctp_endpoint
*ep
,
4906 const struct sctp_association
*asoc
,
4907 const sctp_subtype_t type
,
4909 sctp_cmd_seq_t
*commands
)
4911 /* From 9.1 Abort of an Association
4912 * Upon receipt of the ABORT primitive from its upper
4913 * layer, the endpoint enters CLOSED state and
4914 * discard all outstanding data has been
4915 * acknowledged by its peer. The endpoint accepts no new data
4916 * from its upper layer, but retransmits data to the far end
4917 * if necessary to fill gaps.
4919 struct sctp_chunk
*abort
= arg
;
4922 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(abort
));
4924 /* Even if we can't send the ABORT due to low memory delete the
4925 * TCB. This is a departure from our typical NOMEM handling.
4928 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
4929 SCTP_ERROR(ECONNABORTED
));
4930 /* Delete the established association. */
4931 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
4932 SCTP_PERR(SCTP_ERROR_USER_ABORT
));
4934 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
4935 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
4937 return SCTP_DISPOSITION_ABORT
;
4940 /* We tried an illegal operation on an association which is closed. */
4941 sctp_disposition_t
sctp_sf_error_closed(struct net
*net
,
4942 const struct sctp_endpoint
*ep
,
4943 const struct sctp_association
*asoc
,
4944 const sctp_subtype_t type
,
4946 sctp_cmd_seq_t
*commands
)
4948 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_ERROR
, SCTP_ERROR(-EINVAL
));
4949 return SCTP_DISPOSITION_CONSUME
;
4952 /* We tried an illegal operation on an association which is shutting
4955 sctp_disposition_t
sctp_sf_error_shutdown(struct net
*net
,
4956 const struct sctp_endpoint
*ep
,
4957 const struct sctp_association
*asoc
,
4958 const sctp_subtype_t type
,
4960 sctp_cmd_seq_t
*commands
)
4962 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_ERROR
,
4963 SCTP_ERROR(-ESHUTDOWN
));
4964 return SCTP_DISPOSITION_CONSUME
;
4968 * sctp_cookie_wait_prm_shutdown
4970 * Section: 4 Note: 2
4975 * The RFC does not explicitly address this issue, but is the route through the
4976 * state table when someone issues a shutdown while in COOKIE_WAIT state.
4981 sctp_disposition_t
sctp_sf_cookie_wait_prm_shutdown(
4983 const struct sctp_endpoint
*ep
,
4984 const struct sctp_association
*asoc
,
4985 const sctp_subtype_t type
,
4987 sctp_cmd_seq_t
*commands
)
4989 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
4990 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
4992 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
4993 SCTP_STATE(SCTP_STATE_CLOSED
));
4995 SCTP_INC_STATS(net
, SCTP_MIB_SHUTDOWNS
);
4997 sctp_add_cmd_sf(commands
, SCTP_CMD_DELETE_TCB
, SCTP_NULL());
4999 return SCTP_DISPOSITION_DELETE_TCB
;
5003 * sctp_cookie_echoed_prm_shutdown
5005 * Section: 4 Note: 2
5010 * The RFC does not explcitly address this issue, but is the route through the
5011 * state table when someone issues a shutdown while in COOKIE_ECHOED state.
5016 sctp_disposition_t
sctp_sf_cookie_echoed_prm_shutdown(
5018 const struct sctp_endpoint
*ep
,
5019 const struct sctp_association
*asoc
,
5020 const sctp_subtype_t type
,
5021 void *arg
, sctp_cmd_seq_t
*commands
)
5023 /* There is a single T1 timer, so we should be able to use
5024 * common function with the COOKIE-WAIT state.
5026 return sctp_sf_cookie_wait_prm_shutdown(net
, ep
, asoc
, type
, arg
, commands
);
5030 * sctp_sf_cookie_wait_prm_abort
5032 * Section: 4 Note: 2
5037 * The RFC does not explicitly address this issue, but is the route through the
5038 * state table when someone issues an abort while in COOKIE_WAIT state.
5043 sctp_disposition_t
sctp_sf_cookie_wait_prm_abort(
5045 const struct sctp_endpoint
*ep
,
5046 const struct sctp_association
*asoc
,
5047 const sctp_subtype_t type
,
5049 sctp_cmd_seq_t
*commands
)
5051 struct sctp_chunk
*abort
= arg
;
5053 /* Stop T1-init timer */
5054 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
5055 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
5058 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(abort
));
5060 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
5061 SCTP_STATE(SCTP_STATE_CLOSED
));
5063 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
5065 /* Even if we can't send the ABORT due to low memory delete the
5066 * TCB. This is a departure from our typical NOMEM handling.
5069 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5070 SCTP_ERROR(ECONNREFUSED
));
5071 /* Delete the established association. */
5072 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
5073 SCTP_PERR(SCTP_ERROR_USER_ABORT
));
5075 return SCTP_DISPOSITION_ABORT
;
5079 * sctp_sf_cookie_echoed_prm_abort
5081 * Section: 4 Note: 3
5086 * The RFC does not explcitly address this issue, but is the route through the
5087 * state table when someone issues an abort while in COOKIE_ECHOED state.
5092 sctp_disposition_t
sctp_sf_cookie_echoed_prm_abort(
5094 const struct sctp_endpoint
*ep
,
5095 const struct sctp_association
*asoc
,
5096 const sctp_subtype_t type
,
5098 sctp_cmd_seq_t
*commands
)
5100 /* There is a single T1 timer, so we should be able to use
5101 * common function with the COOKIE-WAIT state.
5103 return sctp_sf_cookie_wait_prm_abort(net
, ep
, asoc
, type
, arg
, commands
);
5107 * sctp_sf_shutdown_pending_prm_abort
5112 * The RFC does not explicitly address this issue, but is the route through the
5113 * state table when someone issues an abort while in SHUTDOWN-PENDING state.
5118 sctp_disposition_t
sctp_sf_shutdown_pending_prm_abort(
5120 const struct sctp_endpoint
*ep
,
5121 const struct sctp_association
*asoc
,
5122 const sctp_subtype_t type
,
5124 sctp_cmd_seq_t
*commands
)
5126 /* Stop the T5-shutdown guard timer. */
5127 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
5128 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
5130 return sctp_sf_do_9_1_prm_abort(net
, ep
, asoc
, type
, arg
, commands
);
5134 * sctp_sf_shutdown_sent_prm_abort
5139 * The RFC does not explicitly address this issue, but is the route through the
5140 * state table when someone issues an abort while in SHUTDOWN-SENT state.
5145 sctp_disposition_t
sctp_sf_shutdown_sent_prm_abort(
5147 const struct sctp_endpoint
*ep
,
5148 const struct sctp_association
*asoc
,
5149 const sctp_subtype_t type
,
5151 sctp_cmd_seq_t
*commands
)
5153 /* Stop the T2-shutdown timer. */
5154 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
5155 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
5157 /* Stop the T5-shutdown guard timer. */
5158 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
5159 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
5161 return sctp_sf_do_9_1_prm_abort(net
, ep
, asoc
, type
, arg
, commands
);
5165 * sctp_sf_cookie_echoed_prm_abort
5170 * The RFC does not explcitly address this issue, but is the route through the
5171 * state table when someone issues an abort while in COOKIE_ECHOED state.
5176 sctp_disposition_t
sctp_sf_shutdown_ack_sent_prm_abort(
5178 const struct sctp_endpoint
*ep
,
5179 const struct sctp_association
*asoc
,
5180 const sctp_subtype_t type
,
5182 sctp_cmd_seq_t
*commands
)
5184 /* The same T2 timer, so we should be able to use
5185 * common function with the SHUTDOWN-SENT state.
5187 return sctp_sf_shutdown_sent_prm_abort(net
, ep
, asoc
, type
, arg
, commands
);
5191 * Process the REQUESTHEARTBEAT primitive
5194 * J) Request Heartbeat
5196 * Format: REQUESTHEARTBEAT(association id, destination transport address)
5200 * Instructs the local endpoint to perform a HeartBeat on the specified
5201 * destination transport address of the given association. The returned
5202 * result should indicate whether the transmission of the HEARTBEAT
5203 * chunk to the destination address is successful.
5205 * Mandatory attributes:
5207 * o association id - local handle to the SCTP association
5209 * o destination transport address - the transport address of the
5210 * association on which a heartbeat should be issued.
5212 sctp_disposition_t
sctp_sf_do_prm_requestheartbeat(
5214 const struct sctp_endpoint
*ep
,
5215 const struct sctp_association
*asoc
,
5216 const sctp_subtype_t type
,
5218 sctp_cmd_seq_t
*commands
)
5220 if (SCTP_DISPOSITION_NOMEM
== sctp_sf_heartbeat(ep
, asoc
, type
,
5221 (struct sctp_transport
*)arg
, commands
))
5222 return SCTP_DISPOSITION_NOMEM
;
5225 * RFC 2960 (bis), section 8.3
5227 * D) Request an on-demand HEARTBEAT on a specific destination
5228 * transport address of a given association.
5230 * The endpoint should increment the respective error counter of
5231 * the destination transport address each time a HEARTBEAT is sent
5232 * to that address and not acknowledged within one RTO.
5235 sctp_add_cmd_sf(commands
, SCTP_CMD_TRANSPORT_HB_SENT
,
5236 SCTP_TRANSPORT(arg
));
5237 return SCTP_DISPOSITION_CONSUME
;
5241 * ADDIP Section 4.1 ASCONF Chunk Procedures
5242 * When an endpoint has an ASCONF signaled change to be sent to the
5243 * remote endpoint it should do A1 to A9
5245 sctp_disposition_t
sctp_sf_do_prm_asconf(struct net
*net
,
5246 const struct sctp_endpoint
*ep
,
5247 const struct sctp_association
*asoc
,
5248 const sctp_subtype_t type
,
5250 sctp_cmd_seq_t
*commands
)
5252 struct sctp_chunk
*chunk
= arg
;
5254 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T4
, SCTP_CHUNK(chunk
));
5255 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
5256 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
5257 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(chunk
));
5258 return SCTP_DISPOSITION_CONSUME
;
5261 /* RE-CONFIG Section 5.1 RECONF Chunk Procedures */
5262 sctp_disposition_t
sctp_sf_do_prm_reconf(struct net
*net
,
5263 const struct sctp_endpoint
*ep
,
5264 const struct sctp_association
*asoc
,
5265 const sctp_subtype_t type
,
5266 void *arg
, sctp_cmd_seq_t
*commands
)
5268 struct sctp_chunk
*chunk
= arg
;
5270 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(chunk
));
5271 return SCTP_DISPOSITION_CONSUME
;
5275 * Ignore the primitive event
5277 * The return value is the disposition of the primitive.
5279 sctp_disposition_t
sctp_sf_ignore_primitive(
5281 const struct sctp_endpoint
*ep
,
5282 const struct sctp_association
*asoc
,
5283 const sctp_subtype_t type
,
5285 sctp_cmd_seq_t
*commands
)
5287 pr_debug("%s: primitive type:%d is ignored\n", __func__
,
5290 return SCTP_DISPOSITION_DISCARD
;
5293 /***************************************************************************
5294 * These are the state functions for the OTHER events.
5295 ***************************************************************************/
5298 * When the SCTP stack has no more user data to send or retransmit, this
5299 * notification is given to the user. Also, at the time when a user app
5300 * subscribes to this event, if there is no data to be sent or
5301 * retransmit, the stack will immediately send up this notification.
5303 sctp_disposition_t
sctp_sf_do_no_pending_tsn(
5305 const struct sctp_endpoint
*ep
,
5306 const struct sctp_association
*asoc
,
5307 const sctp_subtype_t type
,
5309 sctp_cmd_seq_t
*commands
)
5311 struct sctp_ulpevent
*event
;
5313 event
= sctp_ulpevent_make_sender_dry_event(asoc
, GFP_ATOMIC
);
5315 return SCTP_DISPOSITION_NOMEM
;
5317 sctp_add_cmd_sf(commands
, SCTP_CMD_EVENT_ULP
, SCTP_ULPEVENT(event
));
5319 return SCTP_DISPOSITION_CONSUME
;
5323 * Start the shutdown negotiation.
5326 * Once all its outstanding data has been acknowledged, the endpoint
5327 * shall send a SHUTDOWN chunk to its peer including in the Cumulative
5328 * TSN Ack field the last sequential TSN it has received from the peer.
5329 * It shall then start the T2-shutdown timer and enter the SHUTDOWN-SENT
5330 * state. If the timer expires, the endpoint must re-send the SHUTDOWN
5331 * with the updated last sequential TSN received from its peer.
5333 * The return value is the disposition.
5335 sctp_disposition_t
sctp_sf_do_9_2_start_shutdown(
5337 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
;
5345 /* Once all its outstanding data has been acknowledged, the
5346 * endpoint shall send a SHUTDOWN chunk to its peer including
5347 * in the Cumulative TSN Ack field the last sequential TSN it
5348 * has received from the peer.
5350 reply
= sctp_make_shutdown(asoc
, NULL
);
5354 /* Set the transport for the SHUTDOWN chunk and the timeout for the
5355 * T2-shutdown timer.
5357 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T2
, SCTP_CHUNK(reply
));
5359 /* It shall then start the T2-shutdown timer */
5360 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START
,
5361 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
5363 /* RFC 4960 Section 9.2
5364 * The sender of the SHUTDOWN MAY also start an overall guard timer
5365 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5367 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
5368 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
5370 if (asoc
->timeouts
[SCTP_EVENT_TIMEOUT_AUTOCLOSE
])
5371 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
5372 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
5374 /* and enter the SHUTDOWN-SENT state. */
5375 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
5376 SCTP_STATE(SCTP_STATE_SHUTDOWN_SENT
));
5378 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5380 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
5383 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_STOP
, SCTP_NULL());
5385 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
5387 return SCTP_DISPOSITION_CONSUME
;
5390 return SCTP_DISPOSITION_NOMEM
;
5394 * Generate a SHUTDOWN ACK now that everything is SACK'd.
5398 * If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5399 * shall send a SHUTDOWN ACK and start a T2-shutdown timer of its own,
5400 * entering the SHUTDOWN-ACK-SENT state. If the timer expires, the
5401 * endpoint must re-send the SHUTDOWN ACK.
5403 * The return value is the disposition.
5405 sctp_disposition_t
sctp_sf_do_9_2_shutdown_ack(
5407 const struct sctp_endpoint
*ep
,
5408 const struct sctp_association
*asoc
,
5409 const sctp_subtype_t type
,
5411 sctp_cmd_seq_t
*commands
)
5413 struct sctp_chunk
*chunk
= (struct sctp_chunk
*) arg
;
5414 struct sctp_chunk
*reply
;
5416 /* There are 2 ways of getting here:
5417 * 1) called in response to a SHUTDOWN chunk
5418 * 2) called when SCTP_EVENT_NO_PENDING_TSN event is issued.
5420 * For the case (2), the arg parameter is set to NULL. We need
5421 * to check that we have a chunk before accessing it's fields.
5424 if (!sctp_vtag_verify(chunk
, asoc
))
5425 return sctp_sf_pdiscard(net
, ep
, asoc
, type
, arg
, commands
);
5427 /* Make sure that the SHUTDOWN chunk has a valid length. */
5428 if (!sctp_chunk_length_valid(chunk
, sizeof(struct sctp_shutdown_chunk_t
)))
5429 return sctp_sf_violation_chunklen(net
, ep
, asoc
, type
, arg
,
5433 /* If it has no more outstanding DATA chunks, the SHUTDOWN receiver
5434 * shall send a SHUTDOWN ACK ...
5436 reply
= sctp_make_shutdown_ack(asoc
, chunk
);
5440 /* Set the transport for the SHUTDOWN ACK chunk and the timeout for
5441 * the T2-shutdown timer.
5443 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T2
, SCTP_CHUNK(reply
));
5445 /* and start/restart a T2-shutdown timer of its own, */
5446 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
5447 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
5449 if (asoc
->timeouts
[SCTP_EVENT_TIMEOUT_AUTOCLOSE
])
5450 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
5451 SCTP_TO(SCTP_EVENT_TIMEOUT_AUTOCLOSE
));
5453 /* Enter the SHUTDOWN-ACK-SENT state. */
5454 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
5455 SCTP_STATE(SCTP_STATE_SHUTDOWN_ACK_SENT
));
5457 /* sctp-implguide 2.10 Issues with Heartbeating and failover
5459 * HEARTBEAT ... is discontinued after sending either SHUTDOWN
5462 sctp_add_cmd_sf(commands
, SCTP_CMD_HB_TIMERS_STOP
, SCTP_NULL());
5464 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
5466 return SCTP_DISPOSITION_CONSUME
;
5469 return SCTP_DISPOSITION_NOMEM
;
5473 * Ignore the event defined as other
5475 * The return value is the disposition of the event.
5477 sctp_disposition_t
sctp_sf_ignore_other(struct net
*net
,
5478 const struct sctp_endpoint
*ep
,
5479 const struct sctp_association
*asoc
,
5480 const sctp_subtype_t type
,
5482 sctp_cmd_seq_t
*commands
)
5484 pr_debug("%s: the event other type:%d is ignored\n",
5485 __func__
, type
.other
);
5487 return SCTP_DISPOSITION_DISCARD
;
5490 /************************************************************
5491 * These are the state functions for handling timeout events.
5492 ************************************************************/
5497 * Section: 6.3.3 Handle T3-rtx Expiration
5499 * Whenever the retransmission timer T3-rtx expires for a destination
5500 * address, do the following:
5503 * The return value is the disposition of the chunk.
5505 sctp_disposition_t
sctp_sf_do_6_3_3_rtx(struct net
*net
,
5506 const struct sctp_endpoint
*ep
,
5507 const struct sctp_association
*asoc
,
5508 const sctp_subtype_t type
,
5510 sctp_cmd_seq_t
*commands
)
5512 struct sctp_transport
*transport
= arg
;
5514 SCTP_INC_STATS(net
, SCTP_MIB_T3_RTX_EXPIREDS
);
5516 if (asoc
->overall_error_count
>= asoc
->max_retrans
) {
5517 if (asoc
->peer
.zero_window_announced
&&
5518 asoc
->state
== SCTP_STATE_SHUTDOWN_PENDING
) {
5520 * We are here likely because the receiver had its rwnd
5521 * closed for a while and we have not been able to
5522 * transmit the locally queued data within the maximum
5523 * retransmission attempts limit. Start the T5
5524 * shutdown guard timer to give the receiver one last
5525 * chance and some additional time to recover before
5528 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_START_ONCE
,
5529 SCTP_TO(SCTP_EVENT_TIMEOUT_T5_SHUTDOWN_GUARD
));
5531 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5532 SCTP_ERROR(ETIMEDOUT
));
5533 /* CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5534 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
5535 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5536 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
5537 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
5538 return SCTP_DISPOSITION_DELETE_TCB
;
5542 /* E1) For the destination address for which the timer
5543 * expires, adjust its ssthresh with rules defined in Section
5544 * 7.2.3 and set the cwnd <- MTU.
5547 /* E2) For the destination address for which the timer
5548 * expires, set RTO <- RTO * 2 ("back off the timer"). The
5549 * maximum value discussed in rule C7 above (RTO.max) may be
5550 * used to provide an upper bound to this doubling operation.
5553 /* E3) Determine how many of the earliest (i.e., lowest TSN)
5554 * outstanding DATA chunks for the address for which the
5555 * T3-rtx has expired will fit into a single packet, subject
5556 * to the MTU constraint for the path corresponding to the
5557 * destination transport address to which the retransmission
5558 * is being sent (this may be different from the address for
5559 * which the timer expires [see Section 6.4]). Call this
5560 * value K. Bundle and retransmit those K DATA chunks in a
5561 * single packet to the destination endpoint.
5563 * Note: Any DATA chunks that were sent to the address for
5564 * which the T3-rtx timer expired but did not fit in one MTU
5565 * (rule E3 above), should be marked for retransmission and
5566 * sent as soon as cwnd allows (normally when a SACK arrives).
5569 /* Do some failure management (Section 8.2). */
5570 sctp_add_cmd_sf(commands
, SCTP_CMD_STRIKE
, SCTP_TRANSPORT(transport
));
5572 /* NB: Rules E4 and F1 are implicit in R1. */
5573 sctp_add_cmd_sf(commands
, SCTP_CMD_RETRAN
, SCTP_TRANSPORT(transport
));
5575 return SCTP_DISPOSITION_CONSUME
;
5579 * Generate delayed SACK on timeout
5581 * Section: 6.2 Acknowledgement on Reception of DATA Chunks
5583 * The guidelines on delayed acknowledgement algorithm specified in
5584 * Section 4.2 of [RFC2581] SHOULD be followed. Specifically, an
5585 * acknowledgement SHOULD be generated for at least every second packet
5586 * (not every second DATA chunk) received, and SHOULD be generated
5587 * within 200 ms of the arrival of any unacknowledged DATA chunk. In
5588 * some situations it may be beneficial for an SCTP transmitter to be
5589 * more conservative than the algorithms detailed in this document
5590 * allow. However, an SCTP transmitter MUST NOT be more aggressive than
5591 * the following algorithms allow.
5593 sctp_disposition_t
sctp_sf_do_6_2_sack(struct net
*net
,
5594 const struct sctp_endpoint
*ep
,
5595 const struct sctp_association
*asoc
,
5596 const sctp_subtype_t type
,
5598 sctp_cmd_seq_t
*commands
)
5600 SCTP_INC_STATS(net
, SCTP_MIB_DELAY_SACK_EXPIREDS
);
5601 sctp_add_cmd_sf(commands
, SCTP_CMD_GEN_SACK
, SCTP_FORCE());
5602 return SCTP_DISPOSITION_CONSUME
;
5606 * sctp_sf_t1_init_timer_expire
5608 * Section: 4 Note: 2
5613 * RFC 2960 Section 4 Notes
5614 * 2) If the T1-init timer expires, the endpoint MUST retransmit INIT
5615 * and re-start the T1-init timer without changing state. This MUST
5616 * be repeated up to 'Max.Init.Retransmits' times. After that, the
5617 * endpoint MUST abort the initialization process and report the
5618 * error to SCTP user.
5624 sctp_disposition_t
sctp_sf_t1_init_timer_expire(struct net
*net
,
5625 const struct sctp_endpoint
*ep
,
5626 const struct sctp_association
*asoc
,
5627 const sctp_subtype_t type
,
5629 sctp_cmd_seq_t
*commands
)
5631 struct sctp_chunk
*repl
= NULL
;
5632 struct sctp_bind_addr
*bp
;
5633 int attempts
= asoc
->init_err_counter
+ 1;
5635 pr_debug("%s: timer T1 expired (INIT)\n", __func__
);
5637 SCTP_INC_STATS(net
, SCTP_MIB_T1_INIT_EXPIREDS
);
5639 if (attempts
<= asoc
->max_init_attempts
) {
5640 bp
= (struct sctp_bind_addr
*) &asoc
->base
.bind_addr
;
5641 repl
= sctp_make_init(asoc
, bp
, GFP_ATOMIC
, 0);
5643 return SCTP_DISPOSITION_NOMEM
;
5645 /* Choose transport for INIT. */
5646 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_CHOOSE_TRANSPORT
,
5649 /* Issue a sideeffect to do the needed accounting. */
5650 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_RESTART
,
5651 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_INIT
));
5653 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
5655 pr_debug("%s: giving up on INIT, attempts:%d "
5656 "max_init_attempts:%d\n", __func__
, attempts
,
5657 asoc
->max_init_attempts
);
5659 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5660 SCTP_ERROR(ETIMEDOUT
));
5661 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
5662 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5663 return SCTP_DISPOSITION_DELETE_TCB
;
5666 return SCTP_DISPOSITION_CONSUME
;
5670 * sctp_sf_t1_cookie_timer_expire
5672 * Section: 4 Note: 2
5677 * RFC 2960 Section 4 Notes
5678 * 3) If the T1-cookie timer expires, the endpoint MUST retransmit
5679 * COOKIE ECHO and re-start the T1-cookie timer without changing
5680 * state. This MUST be repeated up to 'Max.Init.Retransmits' times.
5681 * After that, the endpoint MUST abort the initialization process and
5682 * report the error to SCTP user.
5688 sctp_disposition_t
sctp_sf_t1_cookie_timer_expire(struct net
*net
,
5689 const struct sctp_endpoint
*ep
,
5690 const struct sctp_association
*asoc
,
5691 const sctp_subtype_t type
,
5693 sctp_cmd_seq_t
*commands
)
5695 struct sctp_chunk
*repl
= NULL
;
5696 int attempts
= asoc
->init_err_counter
+ 1;
5698 pr_debug("%s: timer T1 expired (COOKIE-ECHO)\n", __func__
);
5700 SCTP_INC_STATS(net
, SCTP_MIB_T1_COOKIE_EXPIREDS
);
5702 if (attempts
<= asoc
->max_init_attempts
) {
5703 repl
= sctp_make_cookie_echo(asoc
, NULL
);
5705 return SCTP_DISPOSITION_NOMEM
;
5707 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_CHOOSE_TRANSPORT
,
5709 /* Issue a sideeffect to do the needed accounting. */
5710 sctp_add_cmd_sf(commands
, SCTP_CMD_COOKIEECHO_RESTART
,
5711 SCTP_TO(SCTP_EVENT_TIMEOUT_T1_COOKIE
));
5713 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(repl
));
5715 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5716 SCTP_ERROR(ETIMEDOUT
));
5717 sctp_add_cmd_sf(commands
, SCTP_CMD_INIT_FAILED
,
5718 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5719 return SCTP_DISPOSITION_DELETE_TCB
;
5722 return SCTP_DISPOSITION_CONSUME
;
5725 /* RFC2960 9.2 If the timer expires, the endpoint must re-send the SHUTDOWN
5726 * with the updated last sequential TSN received from its peer.
5728 * An endpoint should limit the number of retransmissions of the
5729 * SHUTDOWN chunk to the protocol parameter 'Association.Max.Retrans'.
5730 * If this threshold is exceeded the endpoint should destroy the TCB and
5731 * MUST report the peer endpoint unreachable to the upper layer (and
5732 * thus the association enters the CLOSED state). The reception of any
5733 * packet from its peer (i.e. as the peer sends all of its queued DATA
5734 * chunks) should clear the endpoint's retransmission count and restart
5735 * the T2-Shutdown timer, giving its peer ample opportunity to transmit
5736 * all of its queued DATA chunks that have not yet been sent.
5738 sctp_disposition_t
sctp_sf_t2_timer_expire(struct net
*net
,
5739 const struct sctp_endpoint
*ep
,
5740 const struct sctp_association
*asoc
,
5741 const sctp_subtype_t type
,
5743 sctp_cmd_seq_t
*commands
)
5745 struct sctp_chunk
*reply
= NULL
;
5747 pr_debug("%s: timer T2 expired\n", __func__
);
5749 SCTP_INC_STATS(net
, SCTP_MIB_T2_SHUTDOWN_EXPIREDS
);
5751 ((struct sctp_association
*)asoc
)->shutdown_retries
++;
5753 if (asoc
->overall_error_count
>= asoc
->max_retrans
) {
5754 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5755 SCTP_ERROR(ETIMEDOUT
));
5756 /* Note: CMD_ASSOC_FAILED calls CMD_DELETE_TCB. */
5757 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
5758 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5759 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
5760 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
5761 return SCTP_DISPOSITION_DELETE_TCB
;
5764 switch (asoc
->state
) {
5765 case SCTP_STATE_SHUTDOWN_SENT
:
5766 reply
= sctp_make_shutdown(asoc
, NULL
);
5769 case SCTP_STATE_SHUTDOWN_ACK_SENT
:
5770 reply
= sctp_make_shutdown_ack(asoc
, NULL
);
5781 /* Do some failure management (Section 8.2).
5782 * If we remove the transport an SHUTDOWN was last sent to, don't
5783 * do failure management.
5785 if (asoc
->shutdown_last_sent_to
)
5786 sctp_add_cmd_sf(commands
, SCTP_CMD_STRIKE
,
5787 SCTP_TRANSPORT(asoc
->shutdown_last_sent_to
));
5789 /* Set the transport for the SHUTDOWN/ACK chunk and the timeout for
5790 * the T2-shutdown timer.
5792 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T2
, SCTP_CHUNK(reply
));
5794 /* Restart the T2-shutdown timer. */
5795 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
5796 SCTP_TO(SCTP_EVENT_TIMEOUT_T2_SHUTDOWN
));
5797 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
5798 return SCTP_DISPOSITION_CONSUME
;
5801 return SCTP_DISPOSITION_NOMEM
;
5805 * ADDIP Section 4.1 ASCONF CHunk Procedures
5806 * If the T4 RTO timer expires the endpoint should do B1 to B5
5808 sctp_disposition_t
sctp_sf_t4_timer_expire(
5810 const struct sctp_endpoint
*ep
,
5811 const struct sctp_association
*asoc
,
5812 const sctp_subtype_t type
,
5814 sctp_cmd_seq_t
*commands
)
5816 struct sctp_chunk
*chunk
= asoc
->addip_last_asconf
;
5817 struct sctp_transport
*transport
= chunk
->transport
;
5819 SCTP_INC_STATS(net
, SCTP_MIB_T4_RTO_EXPIREDS
);
5821 /* ADDIP 4.1 B1) Increment the error counters and perform path failure
5822 * detection on the appropriate destination address as defined in
5823 * RFC2960 [5] section 8.1 and 8.2.
5826 sctp_add_cmd_sf(commands
, SCTP_CMD_STRIKE
,
5827 SCTP_TRANSPORT(transport
));
5829 /* Reconfig T4 timer and transport. */
5830 sctp_add_cmd_sf(commands
, SCTP_CMD_SETUP_T4
, SCTP_CHUNK(chunk
));
5832 /* ADDIP 4.1 B2) Increment the association error counters and perform
5833 * endpoint failure detection on the association as defined in
5834 * RFC2960 [5] section 8.1 and 8.2.
5835 * association error counter is incremented in SCTP_CMD_STRIKE.
5837 if (asoc
->overall_error_count
>= asoc
->max_retrans
) {
5838 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_STOP
,
5839 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
5840 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5841 SCTP_ERROR(ETIMEDOUT
));
5842 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
5843 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5844 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
5845 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
5846 return SCTP_DISPOSITION_ABORT
;
5849 /* ADDIP 4.1 B3) Back-off the destination address RTO value to which
5850 * the ASCONF chunk was sent by doubling the RTO timer value.
5851 * This is done in SCTP_CMD_STRIKE.
5854 /* ADDIP 4.1 B4) Re-transmit the ASCONF Chunk last sent and if possible
5855 * choose an alternate destination address (please refer to RFC2960
5856 * [5] section 6.4.1). An endpoint MUST NOT add new parameters to this
5857 * chunk, it MUST be the same (including its serial number) as the last
5860 sctp_chunk_hold(asoc
->addip_last_asconf
);
5861 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
5862 SCTP_CHUNK(asoc
->addip_last_asconf
));
5864 /* ADDIP 4.1 B5) Restart the T-4 RTO timer. Note that if a different
5865 * destination is selected, then the RTO used will be that of the new
5866 * destination address.
5868 sctp_add_cmd_sf(commands
, SCTP_CMD_TIMER_RESTART
,
5869 SCTP_TO(SCTP_EVENT_TIMEOUT_T4_RTO
));
5871 return SCTP_DISPOSITION_CONSUME
;
5874 /* sctpimpguide-05 Section 2.12.2
5875 * The sender of the SHUTDOWN MAY also start an overall guard timer
5876 * 'T5-shutdown-guard' to bound the overall time for shutdown sequence.
5877 * At the expiration of this timer the sender SHOULD abort the association
5878 * by sending an ABORT chunk.
5880 sctp_disposition_t
sctp_sf_t5_timer_expire(struct net
*net
,
5881 const struct sctp_endpoint
*ep
,
5882 const struct sctp_association
*asoc
,
5883 const sctp_subtype_t type
,
5885 sctp_cmd_seq_t
*commands
)
5887 struct sctp_chunk
*reply
= NULL
;
5889 pr_debug("%s: timer T5 expired\n", __func__
);
5891 SCTP_INC_STATS(net
, SCTP_MIB_T5_SHUTDOWN_GUARD_EXPIREDS
);
5893 reply
= sctp_make_abort(asoc
, NULL
, 0);
5897 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
, SCTP_CHUNK(reply
));
5898 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
5899 SCTP_ERROR(ETIMEDOUT
));
5900 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
5901 SCTP_PERR(SCTP_ERROR_NO_ERROR
));
5903 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
5904 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
5906 return SCTP_DISPOSITION_DELETE_TCB
;
5908 return SCTP_DISPOSITION_NOMEM
;
5911 /* Handle expiration of AUTOCLOSE timer. When the autoclose timer expires,
5912 * the association is automatically closed by starting the shutdown process.
5913 * The work that needs to be done is same as when SHUTDOWN is initiated by
5914 * the user. So this routine looks same as sctp_sf_do_9_2_prm_shutdown().
5916 sctp_disposition_t
sctp_sf_autoclose_timer_expire(
5918 const struct sctp_endpoint
*ep
,
5919 const struct sctp_association
*asoc
,
5920 const sctp_subtype_t type
,
5922 sctp_cmd_seq_t
*commands
)
5926 SCTP_INC_STATS(net
, SCTP_MIB_AUTOCLOSE_EXPIREDS
);
5928 /* From 9.2 Shutdown of an Association
5929 * Upon receipt of the SHUTDOWN primitive from its upper
5930 * layer, the endpoint enters SHUTDOWN-PENDING state and
5931 * remains there until all outstanding data has been
5932 * acknowledged by its peer. The endpoint accepts no new data
5933 * from its upper layer, but retransmits data to the far end
5934 * if necessary to fill gaps.
5936 sctp_add_cmd_sf(commands
, SCTP_CMD_NEW_STATE
,
5937 SCTP_STATE(SCTP_STATE_SHUTDOWN_PENDING
));
5939 disposition
= SCTP_DISPOSITION_CONSUME
;
5940 if (sctp_outq_is_empty(&asoc
->outqueue
)) {
5941 disposition
= sctp_sf_do_9_2_start_shutdown(net
, ep
, asoc
, type
,
5947 /*****************************************************************************
5948 * These are sa state functions which could apply to all types of events.
5949 ****************************************************************************/
5952 * This table entry is not implemented.
5955 * (endpoint, asoc, chunk)
5957 * The return value is the disposition of the chunk.
5959 sctp_disposition_t
sctp_sf_not_impl(struct net
*net
,
5960 const struct sctp_endpoint
*ep
,
5961 const struct sctp_association
*asoc
,
5962 const sctp_subtype_t type
,
5964 sctp_cmd_seq_t
*commands
)
5966 return SCTP_DISPOSITION_NOT_IMPL
;
5970 * This table entry represents a bug.
5973 * (endpoint, asoc, chunk)
5975 * The return value is the disposition of the chunk.
5977 sctp_disposition_t
sctp_sf_bug(struct net
*net
,
5978 const struct sctp_endpoint
*ep
,
5979 const struct sctp_association
*asoc
,
5980 const sctp_subtype_t type
,
5982 sctp_cmd_seq_t
*commands
)
5984 return SCTP_DISPOSITION_BUG
;
5988 * This table entry represents the firing of a timer in the wrong state.
5989 * Since timer deletion cannot be guaranteed a timer 'may' end up firing
5990 * when the association is in the wrong state. This event should
5991 * be ignored, so as to prevent any rearming of the timer.
5994 * (endpoint, asoc, chunk)
5996 * The return value is the disposition of the chunk.
5998 sctp_disposition_t
sctp_sf_timer_ignore(struct net
*net
,
5999 const struct sctp_endpoint
*ep
,
6000 const struct sctp_association
*asoc
,
6001 const sctp_subtype_t type
,
6003 sctp_cmd_seq_t
*commands
)
6005 pr_debug("%s: timer %d ignored\n", __func__
, type
.chunk
);
6007 return SCTP_DISPOSITION_CONSUME
;
6010 /********************************************************************
6011 * 2nd Level Abstractions
6012 ********************************************************************/
6014 /* Pull the SACK chunk based on the SACK header. */
6015 static struct sctp_sackhdr
*sctp_sm_pull_sack(struct sctp_chunk
*chunk
)
6017 struct sctp_sackhdr
*sack
;
6022 /* Protect ourselves from reading too far into
6023 * the skb from a bogus sender.
6025 sack
= (struct sctp_sackhdr
*) chunk
->skb
->data
;
6027 num_blocks
= ntohs(sack
->num_gap_ack_blocks
);
6028 num_dup_tsns
= ntohs(sack
->num_dup_tsns
);
6029 len
= sizeof(struct sctp_sackhdr
);
6030 len
+= (num_blocks
+ num_dup_tsns
) * sizeof(__u32
);
6031 if (len
> chunk
->skb
->len
)
6034 skb_pull(chunk
->skb
, len
);
6039 /* Create an ABORT packet to be sent as a response, with the specified
6042 static struct sctp_packet
*sctp_abort_pkt_new(struct net
*net
,
6043 const struct sctp_endpoint
*ep
,
6044 const struct sctp_association
*asoc
,
6045 struct sctp_chunk
*chunk
,
6046 const void *payload
,
6049 struct sctp_packet
*packet
;
6050 struct sctp_chunk
*abort
;
6052 packet
= sctp_ootb_pkt_new(net
, asoc
, chunk
);
6056 * The T bit will be set if the asoc is NULL.
6058 abort
= sctp_make_abort(asoc
, chunk
, paylen
);
6060 sctp_ootb_pkt_free(packet
);
6064 /* Reflect vtag if T-Bit is set */
6065 if (sctp_test_T_bit(abort
))
6066 packet
->vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
6068 /* Add specified error causes, i.e., payload, to the
6071 sctp_addto_chunk(abort
, paylen
, payload
);
6073 /* Set the skb to the belonging sock for accounting. */
6074 abort
->skb
->sk
= ep
->base
.sk
;
6076 sctp_packet_append_chunk(packet
, abort
);
6083 /* Allocate a packet for responding in the OOTB conditions. */
6084 static struct sctp_packet
*sctp_ootb_pkt_new(struct net
*net
,
6085 const struct sctp_association
*asoc
,
6086 const struct sctp_chunk
*chunk
)
6088 struct sctp_packet
*packet
;
6089 struct sctp_transport
*transport
;
6094 /* Get the source and destination port from the inbound packet. */
6095 sport
= ntohs(chunk
->sctp_hdr
->dest
);
6096 dport
= ntohs(chunk
->sctp_hdr
->source
);
6098 /* The V-tag is going to be the same as the inbound packet if no
6099 * association exists, otherwise, use the peer's vtag.
6102 /* Special case the INIT-ACK as there is no peer's vtag
6105 switch (chunk
->chunk_hdr
->type
) {
6106 case SCTP_CID_INIT_ACK
:
6108 sctp_initack_chunk_t
*initack
;
6110 initack
= (sctp_initack_chunk_t
*)chunk
->chunk_hdr
;
6111 vtag
= ntohl(initack
->init_hdr
.init_tag
);
6115 vtag
= asoc
->peer
.i
.init_tag
;
6119 /* Special case the INIT and stale COOKIE_ECHO as there is no
6122 switch (chunk
->chunk_hdr
->type
) {
6125 sctp_init_chunk_t
*init
;
6127 init
= (sctp_init_chunk_t
*)chunk
->chunk_hdr
;
6128 vtag
= ntohl(init
->init_hdr
.init_tag
);
6132 vtag
= ntohl(chunk
->sctp_hdr
->vtag
);
6137 /* Make a transport for the bucket, Eliza... */
6138 transport
= sctp_transport_new(net
, sctp_source(chunk
), GFP_ATOMIC
);
6142 /* Cache a route for the transport with the chunk's destination as
6143 * the source address.
6145 sctp_transport_route(transport
, (union sctp_addr
*)&chunk
->dest
,
6146 sctp_sk(net
->sctp
.ctl_sock
));
6148 packet
= &transport
->packet
;
6149 sctp_packet_init(packet
, transport
, sport
, dport
);
6150 sctp_packet_config(packet
, vtag
, 0);
6158 /* Free the packet allocated earlier for responding in the OOTB condition. */
6159 void sctp_ootb_pkt_free(struct sctp_packet
*packet
)
6161 sctp_transport_free(packet
->transport
);
6164 /* Send a stale cookie error when a invalid COOKIE ECHO chunk is found */
6165 static void sctp_send_stale_cookie_err(struct net
*net
,
6166 const struct sctp_endpoint
*ep
,
6167 const struct sctp_association
*asoc
,
6168 const struct sctp_chunk
*chunk
,
6169 sctp_cmd_seq_t
*commands
,
6170 struct sctp_chunk
*err_chunk
)
6172 struct sctp_packet
*packet
;
6175 packet
= sctp_ootb_pkt_new(net
, asoc
, chunk
);
6177 struct sctp_signed_cookie
*cookie
;
6179 /* Override the OOTB vtag from the cookie. */
6180 cookie
= chunk
->subh
.cookie_hdr
;
6181 packet
->vtag
= cookie
->c
.peer_vtag
;
6183 /* Set the skb to the belonging sock for accounting. */
6184 err_chunk
->skb
->sk
= ep
->base
.sk
;
6185 sctp_packet_append_chunk(packet
, err_chunk
);
6186 sctp_add_cmd_sf(commands
, SCTP_CMD_SEND_PKT
,
6187 SCTP_PACKET(packet
));
6188 SCTP_INC_STATS(net
, SCTP_MIB_OUTCTRLCHUNKS
);
6190 sctp_chunk_free (err_chunk
);
6195 /* Process a data chunk */
6196 static int sctp_eat_data(const struct sctp_association
*asoc
,
6197 struct sctp_chunk
*chunk
,
6198 sctp_cmd_seq_t
*commands
)
6200 sctp_datahdr_t
*data_hdr
;
6201 struct sctp_chunk
*err
;
6203 sctp_verb_t deliver
;
6206 struct sctp_tsnmap
*map
= (struct sctp_tsnmap
*)&asoc
->peer
.tsn_map
;
6207 struct sock
*sk
= asoc
->base
.sk
;
6208 struct net
*net
= sock_net(sk
);
6213 data_hdr
= chunk
->subh
.data_hdr
= (sctp_datahdr_t
*)chunk
->skb
->data
;
6214 skb_pull(chunk
->skb
, sizeof(sctp_datahdr_t
));
6216 tsn
= ntohl(data_hdr
->tsn
);
6217 pr_debug("%s: TSN 0x%x\n", __func__
, tsn
);
6219 /* ASSERT: Now skb->data is really the user data. */
6221 /* Process ECN based congestion.
6223 * Since the chunk structure is reused for all chunks within
6224 * a packet, we use ecn_ce_done to track if we've already
6225 * done CE processing for this packet.
6227 * We need to do ECN processing even if we plan to discard the
6231 if (asoc
->peer
.ecn_capable
&& !chunk
->ecn_ce_done
) {
6232 struct sctp_af
*af
= SCTP_INPUT_CB(chunk
->skb
)->af
;
6233 chunk
->ecn_ce_done
= 1;
6235 if (af
->is_ce(sctp_gso_headskb(chunk
->skb
))) {
6236 /* Do real work as sideffect. */
6237 sctp_add_cmd_sf(commands
, SCTP_CMD_ECN_CE
,
6242 tmp
= sctp_tsnmap_check(&asoc
->peer
.tsn_map
, tsn
);
6244 /* The TSN is too high--silently discard the chunk and
6245 * count on it getting retransmitted later.
6248 chunk
->asoc
->stats
.outofseqtsns
++;
6249 return SCTP_IERROR_HIGH_TSN
;
6250 } else if (tmp
> 0) {
6251 /* This is a duplicate. Record it. */
6252 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_DUP
, SCTP_U32(tsn
));
6253 return SCTP_IERROR_DUP_TSN
;
6256 /* This is a new TSN. */
6258 /* Discard if there is no room in the receive window.
6259 * Actually, allow a little bit of overflow (up to a MTU).
6261 datalen
= ntohs(chunk
->chunk_hdr
->length
);
6262 datalen
-= sizeof(sctp_data_chunk_t
);
6264 deliver
= SCTP_CMD_CHUNK_ULP
;
6266 /* Think about partial delivery. */
6267 if ((datalen
>= asoc
->rwnd
) && (!asoc
->ulpq
.pd_mode
)) {
6269 /* Even if we don't accept this chunk there is
6272 sctp_add_cmd_sf(commands
, SCTP_CMD_PART_DELIVER
, SCTP_NULL());
6275 /* Spill over rwnd a little bit. Note: While allowed, this spill over
6276 * seems a bit troublesome in that frag_point varies based on
6277 * PMTU. In cases, such as loopback, this might be a rather
6280 if ((!chunk
->data_accepted
) && (!asoc
->rwnd
|| asoc
->rwnd_over
||
6281 (datalen
> asoc
->rwnd
+ asoc
->frag_point
))) {
6283 /* If this is the next TSN, consider reneging to make
6284 * room. Note: Playing nice with a confused sender. A
6285 * malicious sender can still eat up all our buffer
6286 * space and in the future we may want to detect and
6287 * do more drastic reneging.
6289 if (sctp_tsnmap_has_gap(map
) &&
6290 (sctp_tsnmap_get_ctsn(map
) + 1) == tsn
) {
6291 pr_debug("%s: reneging for tsn:%u\n", __func__
, tsn
);
6292 deliver
= SCTP_CMD_RENEGE
;
6294 pr_debug("%s: discard tsn:%u len:%zu, rwnd:%d\n",
6295 __func__
, tsn
, datalen
, asoc
->rwnd
);
6297 return SCTP_IERROR_IGNORE_TSN
;
6302 * Also try to renege to limit our memory usage in the event that
6303 * we are under memory pressure
6304 * If we can't renege, don't worry about it, the sk_rmem_schedule
6305 * in sctp_ulpevent_make_rcvmsg will drop the frame if we grow our
6306 * memory usage too much
6308 if (*sk
->sk_prot_creator
->memory_pressure
) {
6309 if (sctp_tsnmap_has_gap(map
) &&
6310 (sctp_tsnmap_get_ctsn(map
) + 1) == tsn
) {
6311 pr_debug("%s: under pressure, reneging for tsn:%u\n",
6313 deliver
= SCTP_CMD_RENEGE
;
6318 * Section 3.3.10.9 No User Data (9)
6322 * No User Data: This error cause is returned to the originator of a
6323 * DATA chunk if a received DATA chunk has no user data.
6325 if (unlikely(0 == datalen
)) {
6326 err
= sctp_make_abort_no_data(asoc
, chunk
, tsn
);
6328 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
6331 /* We are going to ABORT, so we might as well stop
6332 * processing the rest of the chunks in the packet.
6334 sctp_add_cmd_sf(commands
, SCTP_CMD_DISCARD_PACKET
, SCTP_NULL());
6335 sctp_add_cmd_sf(commands
, SCTP_CMD_SET_SK_ERR
,
6336 SCTP_ERROR(ECONNABORTED
));
6337 sctp_add_cmd_sf(commands
, SCTP_CMD_ASSOC_FAILED
,
6338 SCTP_PERR(SCTP_ERROR_NO_DATA
));
6339 SCTP_INC_STATS(net
, SCTP_MIB_ABORTEDS
);
6340 SCTP_DEC_STATS(net
, SCTP_MIB_CURRESTAB
);
6341 return SCTP_IERROR_NO_DATA
;
6344 chunk
->data_accepted
= 1;
6346 /* Note: Some chunks may get overcounted (if we drop) or overcounted
6347 * if we renege and the chunk arrives again.
6349 if (chunk
->chunk_hdr
->flags
& SCTP_DATA_UNORDERED
) {
6350 SCTP_INC_STATS(net
, SCTP_MIB_INUNORDERCHUNKS
);
6352 chunk
->asoc
->stats
.iuodchunks
++;
6354 SCTP_INC_STATS(net
, SCTP_MIB_INORDERCHUNKS
);
6356 chunk
->asoc
->stats
.iodchunks
++;
6360 /* RFC 2960 6.5 Stream Identifier and Stream Sequence Number
6362 * If an endpoint receive a DATA chunk with an invalid stream
6363 * identifier, it shall acknowledge the reception of the DATA chunk
6364 * following the normal procedure, immediately send an ERROR chunk
6365 * with cause set to "Invalid Stream Identifier" (See Section 3.3.10)
6366 * and discard the DATA chunk.
6368 sid
= ntohs(data_hdr
->stream
);
6369 if (sid
>= asoc
->stream
.incnt
) {
6370 /* Mark tsn as received even though we drop it */
6371 sctp_add_cmd_sf(commands
, SCTP_CMD_REPORT_TSN
, SCTP_U32(tsn
));
6373 err
= sctp_make_op_error(asoc
, chunk
, SCTP_ERROR_INV_STRM
,
6375 sizeof(data_hdr
->stream
),
6378 sctp_add_cmd_sf(commands
, SCTP_CMD_REPLY
,
6380 return SCTP_IERROR_BAD_STREAM
;
6383 /* Check to see if the SSN is possible for this TSN.
6384 * The biggest gap we can record is 4K wide. Since SSNs wrap
6385 * at an unsigned short, there is no way that an SSN can
6386 * wrap and for a valid TSN. We can simply check if the current
6387 * SSN is smaller then the next expected one. If it is, it wrapped
6390 ssn
= ntohs(data_hdr
->ssn
);
6391 if (ordered
&& SSN_lt(ssn
, sctp_ssn_peek(&asoc
->stream
, in
, sid
)))
6392 return SCTP_IERROR_PROTO_VIOLATION
;
6394 /* Send the data up to the user. Note: Schedule the
6395 * SCTP_CMD_CHUNK_ULP cmd before the SCTP_CMD_GEN_SACK, as the SACK
6396 * chunk needs the updated rwnd.
6398 sctp_add_cmd_sf(commands
, deliver
, SCTP_CHUNK(chunk
));
6400 return SCTP_IERROR_NO_ERROR
;